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Kiss CM, Bertschi D, Beerli N, Berres M, Kressig RW, Fischer AM. Calf circumference as a surrogate indicator for detecting low muscle mass in hospitalized geriatric patients. Aging Clin Exp Res 2024; 36:25. [PMID: 38321234 PMCID: PMC10847205 DOI: 10.1007/s40520-024-02694-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 01/02/2024] [Indexed: 02/08/2024]
Abstract
BACKGROUND Sarcopenia is characterized by low muscle strength, decreased muscle mass, and decline in physical performance. While the measurements of muscle strength and physical performance are easy to perform, an accurate evaluation of muscle mass is technically more demanding. We therefore evaluated the suitability of calf circumference (CC) as a clinical indicator for muscle mass. METHODS In a cross-sectional single-centre study, geriatric inpatients were assessed for sarcopenia according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) consensus. Calf circumference was tested for correlation with appendicular skeletal muscle mass index (ASMI). Receiver operating characteristic curves (ROC) were used to calculate the discriminatory value of the CC cut-off values to differentiate patients above and below ASMI cut-offs for sarcopenia. RESULTS In this study population (n = 305, age 83.5 ± 7.0 years, BMI 25.7 kg/m2, 65.6% female), the prevalence of sarcopenia was 22.6%. In subjects with low ASMI, mean CC was 29.5 ± 3.4 cm for females and 32.0 ± 3.4 cm for males. A positive relationship between CC and ASMI was found. The optimized cut-off value for CC to identify patients with low ASMI was <31.5 cm for females (sensitivity 78%, specificity 79%), and <33.5 cm for males (sensitivity 71%, specificity 62%). CONCLUSION In clinical settings where imaging technology for muscle mass quantification is not available, simple calf circumference measurement may be used as a dependable indicator for low muscle mass in older adults.
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Affiliation(s)
- Caroline M Kiss
- University Department of Geriatric Medicine FELIX PLATTER, Basel, Switzerland
| | - Dominic Bertschi
- University Department of Geriatric Medicine FELIX PLATTER, Basel, Switzerland
- Department of Geriatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Nadine Beerli
- University Department of Geriatric Medicine FELIX PLATTER, Basel, Switzerland
- Institute of Nursing Science, Basel, Switzerland
| | - Manfred Berres
- Department of Mathematics and Technology, University of Applied Sciences Koblenz, Koblenz, Germany
| | - Reto W Kressig
- University Department of Geriatric Medicine FELIX PLATTER, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Andreas M Fischer
- University Department of Geriatric Medicine FELIX PLATTER, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
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2
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Fischer AM, Kressig RW. [The Impact of Nutrition on Muscle Health in Older Individuals]. Praxis (Bern 1994) 2023; 112:388-397. [PMID: 37282525 DOI: 10.1024/1661-8157/a004005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The Impact of Nutrition on Muscle Health in Older Individuals Abstract: The age-related change in the importance of nutrition for muscle health starts at the age of 50. Considering its effects on the mobility and physical independence of older people, the aging of the musculoskeletal system represents one of the greatest public health challenges and tasks for a demographically aging Switzerland. In particular sarcopenia, a pathological decrease in muscle strength, muscle mass and muscle function beyond the physiological age-related changes, correlates with a significantly increased risk of falls as well as increasing morbidity and mortality. Common chronic diseases related to old age not only promote additional muscle loss but also frailty, leading to an additional decline of the quality of life. General practitioners play a crucial role in the initial assessment of changing life circumstances and activity profiles of older people. Thanks to their medical care over many years they are able to identify functional impairments of their aging patients at an early stage and address them in time. This is important because the combination of a high-protein diet and exercise may be extremely effective for improving muscle health and function. Eating more proteins (taking into account the newly revised and increased daily protein requirement for healthy seniors of 1,0-1,2g/kg body weight (bw)) can significantly slow down age-related muscle loss. Depending on age and comorbidities, the daily protein requirement might be even higher (1,5 to 2,0g/kg bw). According to current studies, a minimal protein amount of 25-35g per main dish is recommended for optimal muscle growth stimulation among older individiuals. Thanks to their highly potent boosting power on myofibrillar protein synthesis rates the amino acid L-leucine and L-leucine-rich foods play an important role in elderly people's diet.
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Affiliation(s)
- Andreas M Fischer
- NutriCare Clinic, Universitäre Altersmedizin, FELIX PLATTER, Basel, Schweiz
| | - Reto W Kressig
- NutriCare Clinic, Universitäre Altersmedizin, FELIX PLATTER, Basel, Schweiz
- Universitäre Altersmedizin FELIX PLATTER und Medizinische Fakultät der Universität Basel, Basel, Schweiz
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3
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Cohen M, Hertweck K, Itkin M, Malitsky S, Dassa B, Fischer AM, Fluhr R. Enhanced proteostasis, lipid remodeling, and nitrogen remobilization define barley flag leaf senescence. J Exp Bot 2022; 73:6816-6837. [PMID: 35918065 DOI: 10.1093/jxb/erac329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
Leaf senescence is a developmental process allowing nutrient remobilization to sink organs. We characterized flag leaf senescence at 7, 14, and 21 d past anthesis in two near-isogenic barley lines varying in the allelic state of the HvNAM1 transcription factor gene, which influences senescence timing. Metabolomics and microscopy indicated that, as senescence progressed, thylakoid lipids were transiently converted to neutral lipids accumulating in lipid droplets. Senescing leaves also exhibited an accumulation of sugars including glucose, while nitrogen compounds (nucleobases, nucleotides, and amino acids) decreased. RNA-Seq analysis suggested lipid catabolism via β-oxidation and the glyoxylate cycle, producing carbon skeletons and feeding respiration as a replacement of the diminished carbon supply from photosynthesis. Comparison of the two barley lines highlighted a more prominent up-regulation of heat stress transcription factor- and chaperone-encoding genes in the late-senescing line, suggesting a role for these genes in the control of leaf longevity. While numerous genes with putative roles in nitrogen remobilization were up-regulated in both lines, several peptidases, nucleases, and nitrogen transporters were more highly induced in the early-senescing line; this finding identifies processes and specific candidates which may affect nitrogen remobilization from senescing barley leaves, downstream of the HvNAM1 transcription factor.
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Affiliation(s)
- Maja Cohen
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Kendra Hertweck
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA
| | - Maxim Itkin
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Sergey Malitsky
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Bareket Dassa
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Andreas M Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA
| | - Robert Fluhr
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
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4
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Fischer AM, Decker JA, Schoepf J, Varga-Szemes A, Flohr T, Schmidt B, Gutjahr R, Sahbaee P, Giovagnoli DA, Emrich T, Martinez JD, Lari KB, Bayer RR, Martin SS. Optimization of contrast material administration for coronary CT angiography using a software-based test-bolus evaluation algorithm. Br J Radiol 2022; 95:20201456. [PMID: 35084228 PMCID: PMC10993975 DOI: 10.1259/bjr.20201456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 11/23/2021] [Accepted: 01/12/2022] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To evaluate the benefit of a prototype circulation time-based test bolus evaluation algorithm for the individualized optimal timing of contrast media (CM) delivery in patients undergoing coronary CT angiography (CCTA). METHODS Thirty-two patients (62 ± 16 years) underwent CCTA using a prototype bolus evaluation tool to determine the optimal time-delay for CM administration. Contrast attenuation, signal-to-noise ratio (SNR), objective, and subjective image quality were evaluated by two independent radiologists. Results were compared to a control cohort (matched for age, sex, body mass index, and tube voltage) of patients who underwent CCTA using the generic test bolus peak attenuation +4 s protocol as scan delay. RESULTS In the study group, the mean time delay to CCTA acquisition was significantly longer (26.0 ± 2.9 s) compared to the control group (23.1 ± 3.5 s; p < 0.01). In the study group, SNR improvement was seen in the right coronary artery (17.5 vs 13; p = 0.028), the left main (15.3 vs 12.3; p = 0.027), and the left anterior descending artery (18.5 vs 14.1; p = 0.048). Subjective image quality was rated higher in the study group (4.75 ± 0.7 vs 3.64 ± 0.5; p < 0.001). CONCLUSIONS The prototype test bolus evaluation algorithm provided a reliable patient-specific scan delay for CCTA that ensured homogenous vascular attenuation, improvement in objective and subjective image quality, and avoidance of beam hardening artifacts. ADVANCES IN KNOWLEDGE The prototype contrast bolus evaluation and optimization tool estimated circulation time-based time-delay improves the overall quality of CCTA.
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Affiliation(s)
- Andreas M Fischer
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- University Department of Geriatric Medicine FELIX PLATTER and
University of Basel, Basel,
Switzerland
| | - Josua A. Decker
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- Department of Diagnostic and Interventional Radiology,
University Hospital Augsburg,
Augsburg, Germany
| | - Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
| | | | | | | | | | - Dante A Giovagnoli
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- Department of Diagnostic and Interventional Radiology,
University Medical Center, Mainz,
Germany
- German Center for Cardiovascular Research (DZHK), Partner Site
Rhine Main, Mainz,
Germany
| | - John D Martinez
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
| | - Kia B Lari
- University of South Carolina School of Medicine
Greenville, Greenville, South
Carolina, USA
| | - Robert R Bayer
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- Division of Cardiology, Department of Medicine, Medical
University of South Carolina, Charleston, South
Carolina, USA
| | - Simon S Martin
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- Department of Diagnostic and Interventional Radiology,
University Hospital Frankfurt,
Frankfurt, Germany
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5
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Yacoub B, Kabakus IM, Schoepf UJ, Giovagnoli VM, Fischer AM, Wichmann JL, Martinez JD, Sharma P, Rapaka S, Sahbaee P, Hoelzer P, Burt JR, Varga-Szemes A, Emrich T. Performance of an Artificial Intelligence-Based Platform Against Clinical Radiology Reports for the Evaluation of Noncontrast Chest CT. Acad Radiol 2022; 29 Suppl 2:S108-S117. [PMID: 33714665 DOI: 10.1016/j.acra.2021.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/01/2021] [Accepted: 02/11/2021] [Indexed: 12/20/2022]
Abstract
RATIONALE AND OBJECTIVES Research on implementation of artificial intelligence (AI) in radiology workflows and its impact on reports remains scarce. In this study, we aim to assess if an AI platform would perform better than clinical radiology reports in evaluating noncontrast chest computed tomography (CT) scans. MATERIALS AND METHODS Consecutive patients who had undergone noncontrast chest CT were retrospectively identified. The radiology reports were reviewed in a binary fashion for reporting of pulmonary lesions, pulmonary emphysema, aortic dilatation, coronary artery calcifications (CAC), and vertebral compression fractures (VCF). CT scans were then processed using an AI platform. The reports' findings and the AI results were subsequently compared to a consensus read by two board-certificated radiologists as reference. RESULTS A total of 100 patients (mean age: 64.2 ± 14.8 years; 57% males) were included in this study. Aortic segmentation and calcium quantification failed to be processed by AI in 2 and 3 cases, respectively. AI showed superior diagnostic performance in identifying aortic dilatation (AI: sensitivity: 96.3%, specificity: 81.4%, AUC: 0.89) vs (Reports: sensitivity: 25.9%, specificity: 100%, AUC: 0.63), p <0.001; and CAC (AI: sensitivity: 89.8%, specificity: 100, AUC: 0.95) vs (Reports: sensitivity: 75.4%, specificity: 94.9%, AUC: 0.85), p = 0.005. Reports had better performance than AI in identifying pulmonary lesions (Reports: sensitivity: 97.6%, specificity: 100%, AUC: 0.99) vs (AI: sensitivity: 92.8%, specificity: 82.4%, AUC: 0.88), p = 0.024; and VCF (Reports: sensitivity:100%, specificity: 100%, AUC: 1.0) vs (AI: sensitivity: 100%, specificity: 63.7%, AUC: 0.82), p <0.001. A comparable diagnostic performance was noted in identifying pulmonary emphysema on AI (sensitivity: 80.6%, specificity: 66.7%. AUC: 0.74) and reports (sensitivity: 74.2%, specificity: 97.1%, AUC: 0.86), p = 0.064. CONCLUSION Our results demonstrate that incorporating AI support platforms into radiology workflows can provide significant added value to clinical radiology reporting.
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Affiliation(s)
- Basel Yacoub
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina
| | - Ismail M Kabakus
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina.
| | - Vincent M Giovagnoli
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina
| | - Andreas M Fischer
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina; University Hospital Basel, University of Basel, Department of Radiology, Basel, Switzerland
| | - Julian L Wichmann
- University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt am Main, Germany; Siemens Healthineers, Erlangen, Germany
| | - John D Martinez
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina
| | | | | | | | | | - Jeremy R Burt
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina; University Medical Center Mainz, Department of Diagnostic and Interventional Radiology, Mainz, Germany; German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany
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6
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Decker JA, Fischer AM, Schoepf UJ, Xiong F, Todoran TM, Aldinger J, Ellis L, Edelman RR, Koktzoglou I, Emrich T, Varga-Szemes A. Quiescent-Interval Slice-Selective MRA Accurately Estimates Intravascular Stent Dimensions Prior to Intervention in Patients With Peripheral Artery Disease. J Magn Reson Imaging 2021; 55:246-254. [PMID: 34323329 DOI: 10.1002/jmri.27864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Quiescent-interval slice-selective (QISS) magnetic resonance angiography (MRA) is a non-contrast alternative for the pre-procedural assessment of patients with peripheral artery disease (PAD). However, the feasibility of pre-procedural stent size estimation using QISS MRA would merit investigation. PURPOSE To evaluate the feasibility of QISS MRA for pre-procedural stent size estimation in PAD patients compared to computed tomography angiography (CTA). STUDY TYPE Retrospective. SUBJECTS Thirty-three PAD patients (68 ± 9 years, 18 men, 15 women). FIELD STRENGTH/SEQUENCE Two-dimensional balanced steady-state free precession QISS MRA at 1.5 T and 3 T. ASSESSMENT All patients received QISS MRA and CTA of the lower extremity run-off followed by interventional digital subtraction angiography (DSA). Stenotic lesion length and diameter were quantified (AMF and AVS with 3 and 13 years of experience in cardiovascular imaging, respectively) to estimate the dimensions of the stent necessary to restore blood flow in the treated arteries. Measured dimensions were adjusted to the closest stent size available. STATISTICAL TESTS The Friedman test with subsequent pairwise Wilcoxon signed-rank test was used to compare the estimated stent dimensions between QISS MRA, CTA, and the physical stent size used for intervention. Intra-class correlation (ICC) analysis was performed to assess inter-reader agreement. Significant differences were considered at P < 0.05. RESULTS No significant difference was observed between estimated stent diameter by QISS MRA or CTA compared to physical stent diameter (8.9 ± 2.9 mm, 8.8 ± 3.0 mm, and 8.8 ± 3.8 mm, respectively; χ2 = 1.45, P = 0.483). There was a significant underestimation of stent length for both QISS MRA and CTA, compared to physical stent length (45.8 ± 27.8 mm, 46.4 ± 29.3 mm, and 50.4 ± 34.0 mm, respectively; χ2 = 11.96) which could be corrected when measurements were adjusted to the next available stent length (χ2 = 2.38, P = 0.303). Inter-reader assessment showed good to excellent agreement between the readers (all ICC ≥0.81). DATA CONCLUSION QISS MRA represents a reliable method for pre-procedural lesion assessment and stent diameter and length estimation in PAD patients. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Josua A Decker
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, USA.,Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Augsburg, Germany
| | - Andreas M Fischer
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, USA
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Fei Xiong
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, USA.,Cardiovascular MR R&D, Siemens Medical Solutions USA Inc., Charleston, South Carolina, USA
| | - Thomas M Todoran
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Jonathan Aldinger
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Lauren Ellis
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Robert R Edelman
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.,Department of Radiology, Northshore University HealthSystem, Evanston, Illinois, USA
| | - Ioannis Koktzoglou
- Department of Radiology, Northshore University HealthSystem, Evanston, Illinois, USA.,Department of Radiology, University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, USA.,Department of Diagnostic and Interventional Radiology, University Medical Center, Mainz, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Rhine Main, Mainz, Germany
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, USA
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7
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Fischer AM, van Assen M, Schoepf UJ, Matuskowitz AJ, Varga-Szemes A, Golden JW, Giovagnoli DA, Tesche C, Bayer RR. Non-invasive fractional flow reserve (FFR CT) in the evaluation of acute chest pain - Concepts and first experiences. Eur J Radiol 2021; 138:109633. [PMID: 33735700 DOI: 10.1016/j.ejrad.2021.109633] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 01/26/2021] [Accepted: 03/03/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate 30 day rate of major adverse cardiac events (MACE) utilizing cCTA and FFRCT for evaluation of patients presenting to the Emergency Department (ED) with acute chest pain. MATERIALS AND METHODS Patients between the ages of 18-95 years who underwent clinically indicated cCTA and FFRCT in the evaluation of acute chest pain in the emergency department were retrospectively evaluated for 30 day MACE, repeat presentation/admission for chest pain, revascularization, and additional testing. RESULTS A total of 59 patients underwent CCTA and subsequent FFRCT for the evaluation of acute chest pain in the ED over the enrollment period. 32 out of 59 patients (54 %) had negative FFRCT (>0.80) out of whom 18 patients (55 %) were discharged from the ED. Out of the 32 patients without functionally significant CAD by FFRCT, 32 patients (100 %) underwent no revascularization and 32 patients (100 %) had no MACE at the 30-day follow-up period. CONCLUSION In this limited retrospective study, patients presenting to the ED with acute chest pain and with CCTA with subsequent FFRCT of >0.8 had no MACE at 30 days; however, for many of these patients results were not available at time of clinical decision making by the ED physician.
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Affiliation(s)
- Andreas M Fischer
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States; Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Facility Mannheim, Heidelberg University, Heidelberg, Germany
| | - Marly van Assen
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States; University Medical Center Groningen, Center for Medical Imaging, Department of Radiology, Groningen, the Netherlands
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States; Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, United States.
| | - Andrew J Matuskowitz
- Division of Emergency Medicine, Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Joseph W Golden
- Division of Internal Medicine, Department of Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Dante A Giovagnoli
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Christian Tesche
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States; Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany; Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany
| | - Richard R Bayer
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States; Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, United States
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8
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Fischer AM, Yacoub B, Savage RH, Martinez JD, Wichmann JL, Sahbaee P, Grbic S, Varga-Szemes A, Schoepf UJ. Machine Learning/Deep Neuronal Network: Routine Application in Chest Computed Tomography and Workflow Considerations. J Thorac Imaging 2021; 35 Suppl 1:S21-S27. [PMID: 32317574 DOI: 10.1097/rti.0000000000000498] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The constantly increasing number of computed tomography (CT) examinations poses major challenges for radiologists. In this article, the additional benefits and potential of an artificial intelligence (AI) analysis platform for chest CT examinations in routine clinical practice will be examined. Specific application examples include AI-based, fully automatic lung segmentation with emphysema quantification, aortic measurements, detection of pulmonary nodules, and bone mineral density measurement. This contribution aims to appraise this AI-based application for value-added diagnosis during routine chest CT examinations and explore future development perspectives.
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Affiliation(s)
- Andreas M Fischer
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, Charleston, SC
| | - Basel Yacoub
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, Charleston, SC
| | - Rock H Savage
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, Charleston, SC
| | - John D Martinez
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, Charleston, SC
| | | | | | | | - Akos Varga-Szemes
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, Charleston, SC
| | - U Joseph Schoepf
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, Charleston, SC
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9
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Martin SS, Giovagnoli DA, Vingiani V, Abadia AF, Fischer AM, Smith HE, Wertis EM, Hook K, Smith SN, Wasden T, Kaminski J, Varga-Szemes A, Vogl TJ, Schoepf UJ. Evaluating a New Contrast Media Injection System in Coronary CT Angiography. Radiol Technol 2021; 92:232-239. [PMID: 33472875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 05/05/2020] [Indexed: 06/12/2023]
Abstract
PURPOSE To evaluate a new contrast media (CM) injection system in patients undergoing coronary computed tomography angiography (CCTA). METHODS Seventy-one consecutive patients (33 men and 38 women, mean age 59.0 ± 14.5 years) who underwent CCTA between February and April 2019 using the CT injection system MEDRAD Stellant FLEX (Bayer) were included retrospectively in this single-center study. Quantitative and qualitative image quality parameters were assessed, and the injection system's usability and operational efficiency were evaluated. Results were compared with a matched control group. RESULTS All examinations were rated as diagnostic. Usability and operational efficiency of the new injector were rated higher than that of the standard injector system, and no significant differences were found for quantitative and qualitative image quality parameters compared with the control group (P ≥ .05). DISCUSSION Software-based injection facilitates individualized CM application while maintaining high image quality standards in CCTA. Diagnostic accuracy analysis was not performed, but as image quality analysis showed no significant differences, no discrepancies regarding this issue are expected. CONCLUSION This study demonstrates that the MEDRAD Stellant FLEX CT injection system allows for consistent high-quality CCTA scanning with increased usability and operational efficiency.
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Affiliation(s)
- Simon S Martin
- Works for the division of cardiovascular imaging at the Medical University of South Carolina in Charleston and the department of diagnostic and interventional radiology at the University Hospital Frankfurt in Germany
| | - Dante A Giovagnoli
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Vincenzo Vingiani
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Andres F Abadia
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Andreas M Fischer
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Hubert E Smith
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Elyse M Wertis
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Kelly Hook
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Sandra N Smith
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Tiffany Wasden
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Jenny Kaminski
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Akos Varga-Szemes
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
| | - Thomas J Vogl
- Works for the department of diagnostic and interventional radiology at the University Hospital Frankfurt
| | - U Joseph Schoepf
- Work for the division of cardiovascular imaging at the Medical University of South Carolina
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Martin SS, Mastrodicasa D, van Assen M, De Cecco CN, Bayer RR, Tesche C, Varga-Szemes A, Fischer AM, Jacobs BE, Sahbaee P, Griffith LP, Matuskowitz AJ, Vogl TJ, Schoepf UJ. Value of Machine Learning-based Coronary CT Fractional Flow Reserve Applied to Triple-Rule-Out CT Angiography in Acute Chest Pain. Radiol Cardiothorac Imaging 2020; 2:e190137. [PMID: 33778579 DOI: 10.1148/ryct.2020190137] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 01/18/2020] [Accepted: 02/17/2020] [Indexed: 11/11/2022]
Abstract
Purpose To evaluate the additional value of noninvasive artificial intelligence (AI)-based CT-derived fractional flow reserve (CT FFR), derived from triple-rule-out coronary CT angiography for acute chest pain (ACP) in the emergency department (ED) setting. Materials and Methods AI-based CT FFR from triple-rule-out CT angiography data sets was retrospectively obtained in 159 of 271 eligible patients (102 men; mean age, 57.0 years ± 9.7 [standard deviation]) presenting to the ED with ACP. The agreement between CT FFR (≤ 0.80) and stenosis at triple-rule-out CT angiography (≥ 50%), as well as downstream cardiac diagnostic testing, was investigated. Furthermore, the predictive value of CT FFR for coronary revascularization and major adverse cardiac events (MACE) was assessed over a 1-year follow-up period. Results CT FFR and triple-rule-out CT angiography demonstrated agreement in severity of coronary artery disease (CAD) in 52% (82 of 159) of all cases. CT FFR of 0.80 and less served as a better predictor for coronary revascularization and MACE than stenosis of 50% and greater at triple-rule-out CT angiography (odds ratio, 3.4; 95% confidence interval: 1.4, 8.2 vs odds ratio, 2.2; 95% confidence interval: 0.9, 5.3) (P < .01). In the subgroup of patients with additional noninvasive cardiac testing (94 of 159), there was higher agreement as to the presence or absence of significant disease with CT FFR (55%) than with coronary triple-rule-out CT angiography (47%) (P = .23). Conclusion CT FFR derived from triple-rule-out CT angiography was a better predictor for coronary revascularization and MACE and showed better agreement with additional diagnostic testing than triple-rule-out CT angiography. Therefore, CT FFR may improve the specificity in identifying patients with ACP with significant CAD in the ED setting and reduce unnecessary downstream testing.© RSNA, 2020See also the commentary by Ihdayhid and Ben Zekry in this issue.
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Affiliation(s)
- Simon S Martin
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Domenico Mastrodicasa
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Marly van Assen
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Carlo N De Cecco
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Richard R Bayer
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Christian Tesche
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Andreas M Fischer
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Brian E Jacobs
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Pooyan Sahbaee
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - L Parkwood Griffith
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Andrew J Matuskowitz
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - Thomas J Vogl
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260 (S.S.M., D.M., M.v.A., C.N.D.C., R.R.B., C.T., A.V.S., A.M.F., B.E.J., L.P.G., U.J.S.); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany (S.S.M., T.J.V.); Stanford University School of Medicine, Department of Radiology, Stanford, Calif (D.M.); Division of Cardiothoracic Imaging, Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (C.N.D.C.); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (R.R.B.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (C.T.); Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, Germany (C.T.); Siemens Medical Solutions USA, Malvern, Pa (P.S.); and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC (A.J.M.)
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Vingiani V, Abadia AF, Schoepf UJ, Fischer AM, Varga-Szemes A, Sahbaee P, Allmendinger T, Giovagnoli DA, Hudson HT, Marano R, Tinnefeld FC, Martin SS. Individualized coronary calcium scoring at any tube voltage using a kV-independent reconstruction algorithm. Eur Radiol 2020; 30:5834-5840. [PMID: 32468107 DOI: 10.1007/s00330-020-06951-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 05/11/2020] [Indexed: 01/17/2023]
Abstract
PURPOSE We prospectively investigate the feasibility of a patient specific automated tube voltage selection (ATVS)-based coronary artery calcium scoring (CACS) protocol, using a kV-independent reconstruction algorithm, to achieve significant dose reductions while maintaining the overall cardiac risk classification. METHODS Forty-three patients (mean age, 61.8 ± 9.0 years; 40% male) underwent a clinically indicated CACS scan at 120kVp, as well as an additional CACS acquisition using an individualized tube voltage between 70 and 130kVp based on the ATVS selection (CARE-kV). Datasets of the additional CACS scans were reconstructed using a kV-independent algorithm that allows for calcium scoring without changing the weighting threshold of 130HU, regardless of the tube voltage chosen for image acquisition. Agatston scores and radiation dose derived from the different ATVS-based CACS studies were compared to the standard acquisition at 120kVp. RESULTS Thirteen patients displayed a score of 0 and were correctly identified with the ATVS protocol. Agatston scores derived from the standard 120kVp (median, 33.4; IQR, 0-289.7) and the patient-tailored kV-independent protocol (median, 47.5; IQR, 0-287.5) showed no significant differences (p = 0.094). The intra-class correlation for Agatston scores derived from the two different protocols was excellent (ICC = 0.99). The mean dose-length-product was 29.8 ± 11.9 mGy × cm using the ATVS protocol and 31.7 ± 11.4 mGy × cm using the standard 120kVp protocol (p < 0.001). Additionally, 95% of patients were classified into the same risk category (0, 1-10, 11-100, 101-400, or > 400) using the patient-tailored protocol. CONCLUSIONS ATVS-based CACS, using a kV-independent algorithm, allows for high accuracy compared to the standard 120kVp scanning, while significantly reducing radiation dose parameters. KEY POINTS • ATVS allows for CT scanning with reduced radiation dose values. • KV-independent CACS is feasible at any tube voltage between 70 and 130 kVp. • ATVS applied to kV-independent CACS can significantly reduce the radiation dose.
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Affiliation(s)
- Vincenzo Vingiani
- Department of Radiology and Radiological Sciences, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.,Department of Diagnostic Imaging, Oncological Radiotherapy and Hematology, Fondazione Policlinico Universitario Agostino Gemelli - IRCCS, Rome, Italy.,Università Cattolica del Sacro Cuore, Rome, Italy
| | - Andres F Abadia
- Department of Radiology and Radiological Sciences, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - U Joseph Schoepf
- Department of Radiology and Radiological Sciences, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.
| | - Andreas M Fischer
- Department of Radiology and Radiological Sciences, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - Akos Varga-Szemes
- Department of Radiology and Radiological Sciences, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - Pooyan Sahbaee
- Computed Tomography - Research & Development, Siemens Healthcare GmbH, Forchheim, Germany.,Siemens Medical Solutions USA, Malvern, PA, USA
| | - Thomas Allmendinger
- Computed Tomography - Research & Development, Siemens Healthcare GmbH, Forchheim, Germany
| | - Dante A Giovagnoli
- Department of Radiology and Radiological Sciences, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - H Todd Hudson
- Department of Radiology and Radiological Sciences, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - Riccardo Marano
- Department of Diagnostic Imaging, Oncological Radiotherapy and Hematology, Fondazione Policlinico Universitario Agostino Gemelli - IRCCS, Rome, Italy.,Università Cattolica del Sacro Cuore, Rome, Italy
| | - Fiona C Tinnefeld
- Department of Radiology and Radiological Sciences, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - Simon S Martin
- Department of Radiology and Radiological Sciences, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.,Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany
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Vingiani V, Abadia AF, Schoepf UJ, Fischer AM, Varga-Szemes A, Sahbaee P, Allmendinger T, Tesche C, Griffith LP, Marano R, Martin SS. Low-kV coronary artery calcium scoring with tin filtration using a kV-independent reconstruction algorithm. J Cardiovasc Comput Tomogr 2020; 14:246-250. [DOI: 10.1016/j.jcct.2019.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/16/2019] [Accepted: 11/20/2019] [Indexed: 10/25/2022]
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Martin SS, van Assen M, Rapaka S, Hudson HT, Fischer AM, Varga-Szemes A, Sahbaee P, Schwemmer C, Gulsun MA, Cimen S, Sharma P, Vogl TJ, Schoepf UJ. Evaluation of a Deep Learning–Based Automated CT Coronary Artery Calcium Scoring Algorithm. JACC Cardiovasc Imaging 2020; 13:524-526. [DOI: 10.1016/j.jcmg.2019.09.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 08/19/2019] [Accepted: 09/13/2019] [Indexed: 11/28/2022]
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Stroud RE, Piccini D, Schoepf UJ, Heerfordt J, Yerly J, Di Sopra L, Rollins JD, Fischer AM, Suranyi P, Varga-Szemes A. Correcting versus resolving respiratory motion in free-breathing whole-heart MRA: a comparison in patients with thoracic aortic disease. Eur Radiol Exp 2019; 3:29. [PMID: 31363865 PMCID: PMC6667582 DOI: 10.1186/s41747-019-0107-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/02/2019] [Indexed: 11/28/2022] Open
Abstract
Background Whole-heart magnetic resonance angiography (MRA) requires sophisticated methods accounting for respiratory motion. Our purpose was to evaluate the image quality of compressed sensing-based respiratory motion-resolved three-dimensional (3D) whole-heart MRA compared with self-navigated motion-corrected whole-heart MRA in patients with known thoracic aorta dilation. Methods Twenty-five patients were prospectively enrolled in this ethically approved study. Whole-heart 1.5-T MRA was acquired using a prototype 3D radial steady-state free-precession free-breathing sequence. The same data were reconstructed with a one-dimensional motion-correction algorithm (1D-MCA) and an extradimensional golden-angle radial sparse parallel reconstruction (XD-GRASP). Subjective image quality was scored and objective image quality was quantified (signal intensity ratio, SIR; vessel sharpness). Wilcoxon, McNemar, and paired t tests were used. Results Subjective image quality was significantly higher using XD-GRASP compared to 1D-MCA (median 4.5, interquartile range 4.5–5.0 versus 4.0 [2.25–4.75]; p < 0.001), as well as signal homogeneity (3.0 [3.0–3.0] versus 2.0 [2.0–3.0]; p = 0.003), and image sharpness (3.0 [2.0–3.0] vs 2.0 [1.25–3.0]; p < 0.001). SIR with the 1D-MCA and XD-GRASP was 6.1 ± 3.9 versus 7.4 ± 2.5, respectively (p < 0.001); while signal homogeneity was 274.2 ± 265.0 versus 199.8 ± 67.2 (p = 0.129). XD-GRASP provided a higher vessel sharpness (45.3 ± 10.7 versus 40.6 ± 101, p = 0.025). Conclusions XD-GRASP-based motion-resolved reconstruction of free-breathing 3D whole-heart MRA datasets provides improved image contrast, sharpness, and signal homogeneity and seems to be a promising technique that overcomes some of the limitations of motion correction or respiratory navigator gating.
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Affiliation(s)
- Robert E Stroud
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
| | - Davide Piccini
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Rue de Bugnon 46, BH 7.84, 1010, Lausanne, Switzerland.,Advanced Clinical Imaging Technology, Siemens Healthcare AG, EPFL QI-E, 1015, Lausanne, Switzerland
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
| | - John Heerfordt
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Rue de Bugnon 46, BH 7.84, 1010, Lausanne, Switzerland.,Advanced Clinical Imaging Technology, Siemens Healthcare AG, EPFL QI-E, 1015, Lausanne, Switzerland
| | - Jérôme Yerly
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Rue de Bugnon 46, BH 7.84, 1010, Lausanne, Switzerland.,Center for Biomedical Imaging (CIBM), Rue de Bugnon 46, BH 7.84, 1010, Lausanne, Switzerland
| | - Lorenzo Di Sopra
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Rue de Bugnon 46, BH 7.84, 1010, Lausanne, Switzerland
| | - Jonathan D Rollins
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
| | - Andreas M Fischer
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA.,Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Pal Suranyi
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA.
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15
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Abstract
SummaryBeçget syndrome is a multisystem disorder characterized by ocular, mucocutaneous, articular, gastrointestinal and neurologic abnormalities. We report here an unusual case of Beçget syndrome, characterized by the importance of the thrombotic events(7 phlebitis of both legs and resection of two toes). Additional manifestations of the Beçget syndrome occurred only 10 years after the first thrombotic episode. The oldest daugther of the propositus and his brother suffered also from thrombophlebitis; this familial history of thrombosis led to the performance of a haemostatic study. A congenital protein S deficiency was found in the propositus and in three of his children. Normal protein S levels were found in nine unrelated patients with Beçget syndrome. Thus this observation suggests that, when thrombotic manifestations are the first and major symptom of Beçget syndrom, an additional cause of thrombosis has to be investigated.
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Affiliation(s)
- O Chafa
- CTS, Service de Médecine, C.H.U. Mustapha, Alger, Algérie
| | - A M Fischer
- Laboratoire d’Hématologie, C.H.U. Necker-Enfants Malades, Paris, France
| | - F Meriane
- CTS, Service de Médecine, C.H.U. Mustapha, Alger, Algérie
| | - T Chellali
- CTS, Service de Médecine, C.H.U. Mustapha, Alger, Algérie
| | - C Sternberg
- Laboratoire d’Hématologie, C.H.U. Necker-Enfants Malades, Paris, France
| | - F Otmani
- CTS, Service de Médecine, C.H.U. Mustapha, Alger, Algérie
| | - M Benabadji
- CTS, Service de Médecine, C.H.U. Mustapha, Alger, Algérie
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16
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Forestier F, Fischer AM, Daffos F, Beguin S, Diner H. Absence of Transplacental Passage of Pentosan Polysulfate During Mid Trimester of Pregnancy. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1661659] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryEight women who were going to have an abortion between the 18th and 23rd week of gestation for chromosomal abnormalities or haemoglobinopathies received intravenously 50 mg of pentosan polysulfate (PSP). Maternal results of haemostasis prior and after the injection of the drug were compared. Fetal coagulation parameters were tested on samples obtained by direct puncture of the umbilical cord under ultrasound guidance, 30 min after injection. Results were compared to those of normal fetuses at the same stage of gestation, obtained in the same conditions. In mothers’ plasma, 30 min after injection, APTT was prolonged, factor Xa generation was markedly impaired, and factor V level was deeply decreased. By contrast, no modifications of these parameters were observed in fetal plasma, 30 min after the injection of PSP to their related mothers when compared to control fetuses. Thus the absence of biological modifications induced by PSP injection could demonstrate that this drug does not cross through the placenta.
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Affiliation(s)
- F Forestier
- The Hôpital N. D. de Bon-Secours, Paris, France
| | | | - F Daffos
- The Hôpital N. D. de Bon-Secours, Paris, France
| | - S Beguin
- The Faculté Necker, Paris, France
| | - H Diner
- The Laboratoire Clin-Midy, Paris, France
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17
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Fischer AM, Cornu P, Sternberg C, Mériane F, Dautzenberg MD, Chafa O, Beguin S, Desnos M. Antithrombin III Alger: A New Homozygous AT III Variant. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1661525] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryA qualitative abnormality of antithrombin III (AT III) was found in the plasma of a 41-year old patient. The plasmatic AT III antigen concentration was 130% and the progressive anti-F IIa and anti-F Xa activities were normal (105% and 137%). The plasma heparin cofactor activity was less than 10%, when measured by F Ila or F Xa inhibition. Crossed immunoelectrophoresis of AT III in the presence of heparin revealed in the plasma an abnormal slow-moving peak. When tested by affinity chromatography on heparin Sepharose, this abnormal AT III did not bind to heparin. Among the investigated relatives, 5 subjects had normal AT III levels, whatever the test used, the nine others having reduced levels of antithrombin heparin cofactor activity (45-61%) but normal levels of immunoreactive AT III (97-122%). Consanguinity was found in the family history. We therefore considered our patient as homozygous for an AT III molecular abnormality affecting the binding site for heparin.
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Affiliation(s)
- A M Fischer
- The Département d’Hématologie, C. H. U. Necker-Enfants Malades, Paris, France
| | - P Cornu
- The Département d’Hématologie, C. H. U. Necker-Enfants Malades, Paris, France
| | - C Sternberg
- The Département d’Hématologie, C. H. U. Necker-Enfants Malades, Paris, France
| | - F Mériane
- The Laboratoire d’Hématologie, C. H. U. Mustapha, Alger, Algérie
| | - M D Dautzenberg
- The Département d’Hématologie, C. H. U. Necker-Enfants Malades, Paris, France
| | - O Chafa
- The Laboratoire d’Hématologie, C. H. U. Mustapha, Alger, Algérie
| | - S Beguin
- The Département d’Hématologie, C. H. U. Necker-Enfants Malades, Paris, France
| | - M Desnos
- The Service de Cardiologie, Hôpital Boucicaut, Paris, France
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18
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Affiliation(s)
- A M Fischer
- Laboratoire d’Hématologie, Faculté Necker-Enfants Malades, 156 rue de Vaugirard, 75015 Paris, France
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19
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Abstract
SummaryIn order to investigate the mechanism of thrombin inactivation in the presence of both antithrombin III (AT III) and α 2-macroglobulin (α 2 M), thrombin and the inhibitors have been purified from human material and thrombin inactivation studied using purified reagents either alone or added to defibrinated plasma. Comparison of clotting and amidolytic activities of residual thrombin allowed to measure the amount of thrombin bound to α 2 M. In a purified reagent system as well as in plasma, part of exogenous thrombin is bound to α 2 M. The amount of bound thrombin is related to α 2 M concentration. Conversely, previous plasma α 2 M depletion by immunoabsorption increases the consumption of heparin-cofactor activity by exogenous thrombin. Thus AT III and α 2 M compete for thrombin inactivation. This finding could be of practical interest in clinical situations associating high plasma α 2 M levels and a decrease of AT III concentration.
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Affiliation(s)
- A M Fischer
- The Department of Haematology, University Hospital Necker-Enfants Malades, Paris, France
| | - J Tapon-Bretaudiere
- The Department of Haematology, University Hospital Necker-Enfants Malades, Paris, France
| | - A Bros
- The Department of Haematology, University Hospital Necker-Enfants Malades, Paris, France
| | - F Josso
- The Department of Haematology, University Hospital Necker-Enfants Malades, Paris, France
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20
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Mason KE, Hilmer JK, Maaty WS, Reeves BD, Grieco PA, Bothner B, Fischer AM. Proteomic comparison of near-isogenic barley (Hordeum vulgare L.) germplasm differing in the allelic state of a major senescence QTL identifies numerous proteins involved in plant pathogen defense. Plant Physiol Biochem 2016; 109:114-127. [PMID: 27665045 DOI: 10.1016/j.plaphy.2016.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/08/2016] [Accepted: 09/09/2016] [Indexed: 05/24/2023]
Abstract
Senescence is the last developmental phase of plant tissues, organs and, in the case of monocarpic senescence, entire plants. In monocarpic crops such as barley, it leads to massive remobilization of nitrogen and other nutrients to developing seeds. To further investigate this process, a proteomic comparison of flag leaves of near-isogenic late- and early-senescing barley germplasm was performed. Protein samples at 14 and 21 days past anthesis were analyzed using both two-dimensional gel-based and label-free quantitative mass spectrometry-based ('shotgun') proteomic techniques. This approach identified >9000 barley proteins, and one-third of them were quantified. Analysis focused on proteins that were significantly (p < 0.05; difference ≥1.5-fold) upregulated in early-senescing line '10_11' as compared to late-senescing variety 'Karl', as these may be functionally important for senescence. Proteins in this group included family 1 pathogenesis-related proteins, intracellular and membrane receptors or co-receptors (NBS-LRRs, LRR-RLKs), enzymes involved in attacking pathogen cell walls (glucanases), enzymes with possible roles in cuticle modification, and enzymes involved in DNA repair. Additionally, proteases and elements of the ubiquitin-proteasome system were upregulated in line '10_11', suggesting involvement of nitrogen remobilization and regulatory processes. Overall, the proteomic data highlight a correlation between early senescence and upregulated defense functions. This correlation emerges more clearly from the current proteomic data than from a previously performed transcriptomic comparison of 'Karl' and '10_11'. Our findings stress the value of studying biological systems at both the transcript and protein levels, and point to the importance of pathogen defense functions during developmental leaf senescence.
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Affiliation(s)
- Katelyn E Mason
- Chemistry and Biochemistry Department, Montana State University, Bozeman, MT 59717, United States
| | - Jonathan K Hilmer
- Chemistry and Biochemistry Department, Montana State University, Bozeman, MT 59717, United States; Proteomics, Metabolomics and Mass Spectrometry Facility, Montana State University, Bozeman, MT 59717, United States
| | - Walid S Maaty
- Chemistry and Biochemistry Department, Montana State University, Bozeman, MT 59717, United States
| | - Benjamin D Reeves
- Chemistry and Biochemistry Department, Montana State University, Bozeman, MT 59717, United States
| | - Paul A Grieco
- Chemistry and Biochemistry Department, Montana State University, Bozeman, MT 59717, United States
| | - Brian Bothner
- Chemistry and Biochemistry Department, Montana State University, Bozeman, MT 59717, United States; Proteomics, Metabolomics and Mass Spectrometry Facility, Montana State University, Bozeman, MT 59717, United States
| | - Andreas M Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717, United States.
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21
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Parrott DL, Huang L, Fischer AM. Downregulation of a barley (Hordeum vulgare) leucine-rich repeat, non-arginine-aspartate receptor-like protein kinase reduces expression of numerous genes involved in plant pathogen defense. Plant Physiol Biochem 2016; 100:130-140. [PMID: 26820571 DOI: 10.1016/j.plaphy.2016.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 01/12/2016] [Indexed: 05/24/2023]
Abstract
Pattern recognition receptors represent a first line of plant defense against pathogens. Comparing the flag leaf transcriptomes of barley (Hordeum vulgare L.) near-isogenic lines varying in the allelic state of a locus controlling senescence, we have previously identified a leucine-rich repeat receptor-like protein kinase gene (LRR-RLK; GenBank accession: AK249842), which was strongly upregulated in leaves of early-as compared to late-senescing germplasm. Bioinformatic analysis indicated that this gene codes for a subfamily XII, non-arginine-aspartate (non-RD) LRR-RLK. Virus-induced gene silencing resulted in a two-fold reduction of transcript levels as compared to controls. Transcriptomic comparison of leaves from untreated plants, from plants treated with virus only without any plant sequences (referred to as 'empty virus' control), and from plants in which AK249842 expression was knocked down identified numerous genes involved in pathogen defense. These genes were strongly induced in 'empty virus' as compared to untreated controls, but their expression was significantly reduced (again compared to 'empty virus' controls) when AK249842 was knocked down, indicating that their expression partially depends on the LRR-RLK investigated here. Expression analysis, using datasets from BarleyBase/PLEXdb, demonstrated that AK249842 transcript levels are heavily influenced by the allelic state of the well-characterized mildew resistance a (Mla) locus, and that the gene is induced after powdery mildew and stem rust infection. Together, our data suggest that AK249842 is a barley pattern recognition receptor with a tentative role in defense against fungal pathogens, setting the stage for its full functional characterization.
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Affiliation(s)
- David L Parrott
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
| | - Li Huang
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
| | - Andreas M Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA.
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22
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Robinson MJF, Fischer AM, Ahuja A, Lesser EN, Maniates H. Roles of "Wanting" and "Liking" in Motivating Behavior: Gambling, Food, and Drug Addictions. Curr Top Behav Neurosci 2016; 27:105-136. [PMID: 26407959 DOI: 10.1007/7854_2015_387] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The motivation to seek out and consume rewards has evolutionarily been driven by the urge to fulfill physiological needs. However in a modern society dominated more by plenty than scarcity, we tend to think of motivation as fueled by the search for pleasure. Here, we argue that two separate but interconnected subcortical and unconscious processes direct motivation: "wanting" and "liking." These two psychological and neuronal processes and their related brain structures typically work together, but can become dissociated, particularly in cases of addiction. In drug addiction, for example, repeated consumption of addictive drugs sensitizes the mesolimbic dopamine system, the primary component of the "wanting" system, resulting in excessive "wanting" for drugs and their cues. This sensitizing process is long-lasting and occurs independently of the "liking" system, which typically remains unchanged or may develop a blunted pleasure response to the drug. The result is excessive drug-taking despite minimal pleasure and intense cue-triggered craving that may promote relapse long after detoxification. Here, we describe the roles of "liking" and "wanting" in general motivation and review recent evidence for a dissociation of "liking" and "wanting" in drug addiction, known as the incentive sensitization theory (Robinson and Berridge 1993). We also make the case that sensitization of the "wanting" system and the resulting dissociation of "liking" and "wanting" occurs in both gambling disorder and food addiction.
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Affiliation(s)
- M J F Robinson
- Department of Psychology, Wesleyan University, 207 High Street, Judd Hall, Middletown, CT, 06459, USA.
| | - A M Fischer
- Department of Psychology, Wesleyan University, 207 High Street, Judd Hall, Middletown, CT, 06459, USA
| | - A Ahuja
- Department of Psychology, Wesleyan University, 207 High Street, Judd Hall, Middletown, CT, 06459, USA
| | - E N Lesser
- Department of Psychology, Wesleyan University, 207 High Street, Judd Hall, Middletown, CT, 06459, USA
| | - H Maniates
- Department of Psychology, Wesleyan University, 207 High Street, Judd Hall, Middletown, CT, 06459, USA
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23
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Ben Said M, Gandrille S, Fischer AM, Darnige L. [Clinical and biological features of patients with essential thrombocythaemia according to their mutational status JAK2 or CALR: Single-center study of 40 patients and review of the literature]. Pathol Biol (Paris) 2015; 63:117-121. [PMID: 25840625 DOI: 10.1016/j.patbio.2015.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 01/27/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND Somatic mutations in the calreticulin gene (CALR) were recently described in essential thrombocythemia (ET) and primary myelofibrosis with non-mutated JAK2 or MPL. The aim of this single-center study was to compare the clinical and biological features of ET patients according to their mutational status. METHODS We included 40 patients with ET followed in hematology consultation. The JAK2 V617F mutation was assessed by quantitative PCR. For the detection of CALR mutations, we performed a PCR amplification of CALR exon 9 followed by direct sequencing. RESULTS Among 40 study patients, 23 (57.5%) harbored V617F JAK2, 12 of the 17 patients without JAK2 mutation harbored CALR, no patient expressed MPL mutation and 5 were negative for all three mutations. Five types of mutations were identified with predominance of 52bp deletion and 5bp insertion (7/12 and 2/12 respectively). The incidence of thrombotic events at diagnosis was significantly higher in JAK2 mutated patients (P<0.05). Biologically, patients with CALR mutation had significantly higher platelet count (P<0.01) and significantly lower hemoglobin level (P<0.05) than those with V617F JAK2 mutation. CONCLUSION JAK2 and CALR mutation screening in ET has a diagnostic value. Each mutation displays a distinct phenotype with uncertain impact on long-term outcome.
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Affiliation(s)
- M Ben Said
- Service d'hématologie biologique, hôpital européen Georges-Pompidou, AP-HP, 20, rue Leblanc, 75908 Paris cedex 15, France.
| | - S Gandrille
- Service d'hématologie biologique, hôpital européen Georges-Pompidou, AP-HP, 20, rue Leblanc, 75908 Paris cedex 15, France; Inserm UMR-S1140, université Paris Descartes, 75270 Paris cedex 06, France.
| | - A M Fischer
- Service d'hématologie biologique, hôpital européen Georges-Pompidou, AP-HP, 20, rue Leblanc, 75908 Paris cedex 15, France.
| | - L Darnige
- Service d'hématologie biologique, hôpital européen Georges-Pompidou, AP-HP, 20, rue Leblanc, 75908 Paris cedex 15, France.
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24
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Journois D, de Raucourt E, Fischer AM, Allanic G, Keita M, de Courcy N. The mechanism of postoperative blood loss reduction by ultrafiltration in cardiac surgery is unlikely to be only mediated by hemoconcentration of coagulation factors. Contrib Nephrol 2015; 116:150-3. [PMID: 8529369 DOI: 10.1159/000424630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- D Journois
- Department of Anesthesia and Intensive Care Medicine, Laennec Hospital, Paris, France
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25
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Tripet B, Mason KE, Eilers BJ, Burns J, Powell P, Fischer AM, Copié V. Structural and biochemical analysis of the Hordeum vulgare L. HvGR-RBP1 protein, a glycine-rich RNA-binding protein involved in the regulation of barley plant development and stress response. Biochemistry 2014; 53:7945-60. [PMID: 25495582 PMCID: PMC4278681 DOI: 10.1021/bi5007223] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 11/25/2014] [Indexed: 12/26/2022]
Abstract
The timing of whole-plant senescence influences important agricultural traits such as yield and grain protein content. Post-transcriptional regulation by plant RNA-binding proteins is essential for proper control of gene expression, development, and stress responses. Here, we report the three-dimensional solution NMR structure and nucleic acid-binding properties of the barley glycine-rich RNA-binding protein HvGR-RBP1, whose transcript has been identified as being >45-fold up-regulated in early-as compared to late-senescing near-isogenic barley germplasm. NMR analysis reveals that HvGR-RBP1 is a multidomain protein comprising a well-folded N-terminal RNA Recognition Motif (RRM) and a structurally disordered C-terminal glycine-rich domain. Chemical shift differences observed in 2D (1)H-(15)N correlation (HSQC) NMR spectra of full-length HvGR-RBP1 and N-HvGR-RBP1 (RRM domain only) suggest that the two domains can interact both in-trans and intramolecularly, similar to what is observed in the tobacco NtGR-RBP1 protein. Further, we show that the RRM domain of HvGR-RBP1 binds single-stranded DNA nucleotide fragments containing the consensus nucleotide sequence 5'-TTCTGX-3' with low micromolar affinity in vitro. We also demonstrate that the C-terminal glycine-rich (HvGR) domain of Hv-GR-RBP1 can interact nonspecifically with ssRNA in vitro. Structural similarities with other plant glycine-rich RNA-binding proteins suggest that HvGR-RBP1 may be multifunctional. Based on gene expression analysis following cold stress in barley and E. coli growth studies following cold shock treatment, we conclude that HvGR-RBP1 functions in a manner similar to cold-shock proteins and harbors RNA chaperone activity. HvGR-RBP1 is therefore not only involved in the regulation of barley development including senescence, but also functions in plant responses to environmental stress.
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MESH Headings
- Cold-Shock Response/physiology
- DNA, Plant/chemistry
- DNA, Plant/genetics
- DNA, Plant/metabolism
- DNA, Single-Stranded/chemistry
- DNA, Single-Stranded/genetics
- DNA, Single-Stranded/metabolism
- Hordeum/genetics
- Hordeum/metabolism
- Plant Proteins/chemistry
- Plant Proteins/genetics
- Plant Proteins/metabolism
- Protein Binding
- Protein Structure, Tertiary
- RNA, Plant/chemistry
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
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Affiliation(s)
- Brian
P. Tripet
- Department of Chemistry and Biochemistry and Department of Plant
Sciences and Plant
Pathology, Montana State University, Bozeman, Montana 59717, United States
| | - Katelyn E. Mason
- Department of Chemistry and Biochemistry and Department of Plant
Sciences and Plant
Pathology, Montana State University, Bozeman, Montana 59717, United States
| | - Brian J. Eilers
- Department of Chemistry and Biochemistry and Department of Plant
Sciences and Plant
Pathology, Montana State University, Bozeman, Montana 59717, United States
| | - Jennifer Burns
- Department of Chemistry and Biochemistry and Department of Plant
Sciences and Plant
Pathology, Montana State University, Bozeman, Montana 59717, United States
| | - Paul Powell
- Department of Chemistry and Biochemistry and Department of Plant
Sciences and Plant
Pathology, Montana State University, Bozeman, Montana 59717, United States
| | - Andreas M. Fischer
- Department of Chemistry and Biochemistry and Department of Plant
Sciences and Plant
Pathology, Montana State University, Bozeman, Montana 59717, United States
| | - Valérie Copié
- Department of Chemistry and Biochemistry and Department of Plant
Sciences and Plant
Pathology, Montana State University, Bozeman, Montana 59717, United States
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26
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Abstract
Cereals including wheat and barley are of primary importance to ensure food security for the 21st century. A combination of lab- and field-based approaches has led to a considerably improved understanding of the importance of organ and particularly of whole-plant (monocarpic) senescence for wheat and barley yield and quality. A delicate balance between senescence timing, grain nutrient content, nutrient-use efficiency, and yield needs to be considered to (further) improve cereal varieties for a given environment and end use. The recent characterization of the Gpc-1 (NAM-1) genes in wheat and barley demonstrates the interdependence of these traits. Lines or varieties with functional Gpc-1 genes demonstrate earlier senescence and enhanced grain protein and micronutrient content but, depending on the environment, somewhat reduced yields. A major effort is needed to dissect regulatory networks centred on additional wheat and barley transcription factors and signalling pathways influencing the senescence process. Similarly, while important molecular details of nutrient (particularly nitrogen) remobilization from senescing organs to developing grains have been identified, important knowledge gaps remain. The genes coding for the major proteases involved in senescence-associated plastidial protein degradation are largely unknown. Membrane transport proteins involved in the different transport steps occurring between senescing organ (such as leaf mesophyll) cells and protein bodies in the endosperm of developing grains remain to be identified or further characterized. Existing data suggest that an improved understanding of all these steps will reveal additional, important targets for continued cereal improvement.
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Affiliation(s)
- Assaf Distelfeld
- Faculty of Life Sciences, Department of Molecular Biology and Ecology of Plants, Tel Aviv University, 69978, Israel
| | - Raz Avni
- Faculty of Life Sciences, Department of Molecular Biology and Ecology of Plants, Tel Aviv University, 69978, Israel
| | - Andreas M Fischer
- Department of Plant Sciences and Plant Pathology, 119 Plant BioScience Building, Montana State University, Bozeman, MT 59717-3150, USA
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27
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Cherns D, Webster RF, Novikov SV, Foxon CT, Fischer AM, Ponce FA, Haigh SJ. Compositional variations in In(0.5)Ga(0.5)N nanorods grown by molecular beam epitaxy. Nanotechnology 2014; 25:215705. [PMID: 24785272 DOI: 10.1088/0957-4484/25/21/215705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The composition of InxGa1 - xN nanorods grown by molecular beam epitaxy with nominal x = 0.5 has been mapped by electron microscopy using Z-contrast imaging and x-ray microanalysis. This shows a coherent and highly strained core-shell structure with a near-atomically sharp boundary between a Ga-rich shell (x ∼ 0.3) and an In-rich core (x ∼ 0.7), which itself has In- and Ga-rich platelets alternating along the growth axis. It is proposed that the shell and core regions are lateral and vertical growth sectors, with the core structure determined by spinodal decomposition.
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Affiliation(s)
- D Cherns
- School of Physics, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
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Mason KE, Tripet BP, Parrott D, Fischer AM, Copié V. ¹H, ¹³C, ¹⁵N backbone and side chain NMR resonance assignments for the N-terminal RNA recognition motif of the HvGR-RBP1 protein involved in the regulation of barley (Hordeum vulgare L.) senescence. Biomol NMR Assign 2014; 8:149-153. [PMID: 23417794 PMCID: PMC3672310 DOI: 10.1007/s12104-013-9472-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 02/08/2013] [Indexed: 05/29/2023]
Abstract
Leaf senescence is an important process in the developmental life of all plant species. Senescence efficiency influences important agricultural traits such as grain protein content and plant growth, which are often limited by nitrogen use. Little is known about the molecular mechanisms regulating this highly orchestrated process. To enhance our understanding of leaf senescence and its regulation, we have undertaken the structural and functional characterization of previously unknown proteins that are involved in the control of senescence in barley (Hordeum vulgare L.). Previous microarray analysis highlighted several barley genes whose transcripts are differentially expressed during senescence, including a specific gene which is greater than 40-fold up-regulated in the flag leaves of early- as compared to late-senescing near-isogenic barley lines at 14 and 21 days past flowering (anthesis). From inspection of its amino acid sequence, this gene is predicted to encode a glycine-rich RNA-binding protein herein referred to as HvGR-RBP1. HvGR-RBP1 has been expressed as a recombinant protein in Escherichia coli, and preliminary NMR data analysis has revealed that its glycine-rich C-terminal region [residues: 93-162] is structurally disordered whereas its N-terminal region [residues: 1-92] forms a well-folded domain. Herein, we report the complete (1)H, (13)C, and (15)N resonance assignments of backbone and sidechain atoms, and the secondary structural topology of the N-terminal RNA recognition motif (RRM) domain of HvGR-RBP1, as a first step to unraveling its structural and functional role in the regulation of barley leaf senescence.
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Affiliation(s)
- Katelyn E. Mason
- Department of Chemistry and Biochemistry, Montana State University, Bozeman MT 59717
| | - Brian P. Tripet
- Department of Chemistry and Biochemistry, Montana State University, Bozeman MT 59717
| | - David Parrott
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman MT 59717
| | - Andreas M. Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman MT 59717
| | - Valérie Copié
- Department of Chemistry and Biochemistry, Montana State University, Bozeman MT 59717
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Schwele S, Fischer AM, Brestrich G, Wlodarski MW, Wagner L, Schmueck M, Roemhild A, Thomas S, Hammer MH, Babel N, Kurtz A, Maciejewski JP, Reinke P, Volk HD. Cytomegalovirus-specific regulatory and effector T cells share TCR clonality--possible relation to repetitive CMV infections. Am J Transplant 2012; 12:669-81. [PMID: 22081907 DOI: 10.1111/j.1600-6143.2011.03842.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cytomegalovirus (CMV) infections have a major impact on morbidity and mortality of transplant patients. Among the complex antiviral T-cell response, CMV-IE-1 antigen-specific CD8+ cells are crucial for preventing CMV disease but do not protect from recurring/lasting CMV reactivation. Recently, we confirmed that adoptive transfer of autologous IE-1/pp65-specific T-cell lines was able to combat severe CMV disease; however, the control of CMV infection was only temporary. We hypothesized that CMV-induced regulatory T cells (iTreg) might be related to recurring/lasting CMV infection. In fact, kidney transplant patients with recurring CMV infections expressed enhanced suppression on CMV response. Analysis of in vitro expanded CD4+ epitope-specific cells revealed that CMV-specific CD4+CD25(high) Treg cells functionally suppress CD25(low) effector T cells (Teff) upon epitope-specific reactivation. Their phenotype is similar to iTreg - CD39(high) /Helios-/IL-2(low) /IFNγ(high) /IL-10±/TGFß-LAP±/FOXP3+ and methylated foxp3 locus. Remarkably, in vitro expanded CD4+CD25(high) iTreg share the same dominant TCR-Vβ-CDR3 clones with functionally distinct CD4+CD25(low) Teff. Moreover, the same clones were present in freshly isolated CD4+CD25(high) and CD4+CD25(low) T cells suggesting their in vivo generation. These findings directly demonstrate that Teff and iTreg can differentiate from one "mother" clone with specificity to the same viral epitope and indicate that peripheral iTreg generation is related to frequent antigen appearance.
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Affiliation(s)
- S Schwele
- Institute of Medical Immunology, Charité- Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany
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Parrott DL, Downs EP, Fischer AM. Control of barley (Hordeum vulgare L.) development and senescence by the interaction between a chromosome six grain protein content locus, day length, and vernalization. J Exp Bot 2012; 63:1329-39. [PMID: 22090442 PMCID: PMC3276093 DOI: 10.1093/jxb/err360] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 10/11/2011] [Accepted: 10/18/2011] [Indexed: 05/18/2023]
Abstract
Regulatory processes controlling traits such as anthesis timing and whole-plant senescence are of primary importance for reproductive success and for crop quality and yield. It has previously been demonstrated that the presence of alleles associated with high grain protein content (GPC) at a locus on barley chromosome six leads to accelerated leaf senescence, and to strong (>10-fold) up-regulation of several genes which may be involved in senescence control. One of these genes (coding for a glycine-rich RNA-binding protein termed HvGR-RBP1) exhibits a high degree of similarity to Arabidopsis glycine-rich RNA-binding protein 7 (AtGRP7), which has been demonstrated to accelerate flowering under both long-day (LD) and short-day (SD) conditions, but not after vernalization. Development of near-isogenic barley lines, differing in the allelic state of the GPC locus, was compared from the seedling stage to maturity under both SD and LD and after vernalization under LD. Intriguingly, pre-anthesis plant development [measured by leaf emergence timing and pre-anthesis (sequential) leaf senescence] was enhanced in high-GPC germplasm. Differences were more pronounced under SD than under LD, but were eliminated by vernalization, associating observed effects with floral induction pathways. By contrast, differences in post-anthesis flag leaf and whole-plant senescence between low- and high-GPC germplasm persisted under all tested conditions, indicating that the GPC locus, possibly through HvGR-RBP1, impacts on both developmental stages. Detailed molecular characterization of this experimental system may allow the dissection of cross-talk between signalling pathways controlling early plant and floral development on one side, and leaf/whole-plant senescence on the other side.
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Affiliation(s)
| | | | - Andreas M. Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
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31
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Sarlon G, Zemani F, David L, Duong Van Huyen JP, Dizier B, Grelac F, Colliec-Jouault S, Galy-Fauroux I, Bruneval P, Fischer AM, Emmerich J, Boisson-Vidal C. Therapeutic effect of fucoidan-stimulated endothelial colony-forming cells in peripheral ischemia. J Thromb Haemost 2012; 10:38-48. [PMID: 22066680 DOI: 10.1111/j.1538-7836.2011.04554.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Fucoidan, an antithrombotic polysaccharide, can induce endothelial colony-forming cells (ECFC) to adopt an angiogenic phenotype in vitro. OBJECTIVES We evaluated the effect of fucoidan on vasculogenesis induced by ECFC in vivo. METHODS We used a murine hindlimb ischemia model to probe the synergic role of fucoidan-treatment and ECFC infusion during tissue repair. RESULTS We found that exposure of ECFC to fucoidan prior to their intravenous injection improved residual muscle blood flow and increased collateral vessel formation. Necrosis of ischemic tissue was significantly reduced on day 14, to 12.1% of the gastronecmius cross-sectional surface area compared with 40.1% in animals injected with untreated-ECFC. ECFC stimulation with fucoidan caused a rapid increase in cell adhesion to activated endothelium in flow conditions, and enhanced transendothelial extravasation. Fucoidan-stimulated ECFC were resistant to shear stresses of up to 21 dyn cm(-2). Direct binding assays showed strong interaction of fucoidan with displaceable binding sites on the ECFC membrane. Bolus intramuscular administration of fucoidan 1 day after surgery reduces rhabdomyolysis. Mice injected with fucoidan (15 mg kg(-1)) had significantly lower mean serum creatine phosphokinase (CPK) activity than control animals. This CPK reduction was correlated with muscle preservation against necrosis (P < 0.001). CONCLUSIONS Fucoidan greatly increases ECFC-mediated angiogenesis in vivo. Its angiogenic effect would be due in part to its transportation to the ischemic site and its release after displacement by proteoglycans present in the extracellular matrix. The use of ECFC and fucoidan together, will be an efficient angiogenesis strategy to provide therapeutic neovascularization.
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Affiliation(s)
- G Sarlon
- INSERM UMRS608, Marseille, France
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Benslimane-Ahmim Z, Heymann D, Dizier B, Lokajczyk A, Brion R, Laurendeau I, Bièche I, Smadja DM, Galy-Fauroux I, Colliec-Jouault S, Fischer AM, Boisson-Vidal C. Osteoprotegerin, a new actor in vasculogenesis, stimulates endothelial colony-forming cells properties. J Thromb Haemost 2011; 9:834-43. [PMID: 21255246 DOI: 10.1111/j.1538-7836.2011.04207.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Osteoprotegerin (OPG), a soluble receptor of the tumour necrosis factor family, and its ligand, the receptor activator of nuclear factor-κB ligand (RANKL), are emerging as important regulators of vascular pathophysiology. OBJECTIVES We evaluated their effects on vasculogenesis induced by endothelial colony-forming cells (ECFC) and on neovessel formation in vivo. METHODS Effects of OPG and RANKL on in vitro angiogenesis were evaluated after ECFC incubation with OPG or RANKL (0-50 ng mL(-1)). Effects on microvessel formation were evaluated with an in vivo murin Matrigel plug assay. Vascularization was evaluated by measuring plug hemoglobin and vascular endothelial growth factor (VEGF)-R2 content 14 days after implantation. RESULTS We found that ECFC expressed OPG and RANK but not RANKL mRNA. Treatment of ECFC with VEGF or stromal cell-derived factor-1 (SDF-1) upregulated OPG mRNA expression. OPG stimulated ECFC migration (P < 0.05), chemotaxis (P < 0.05) and vascular cord formation on Matrigel(®) (P < 0.01). These effects were correlated with SDF-1 mRNA overexpression, which was 30-fold higher after 4 h of OPG stimulation (P < 0.01). OPG-mediated angiogenesis involved the MAPK signaling pathway as well as Akt or mTOR cascades. RANKL also showed pro-vasculogenic effects in vitro. OPG combined with FGF-2 promoted neovessel formation in vivo, whereas RANKL had no effect. CONCLUSIONS OPG induces ECFC activation and is a positive regulator of microvessel formation in vivo. Our results suggest that the OPG/RANK/RANKL axis may be involved in vasculogenesis and strongly support a modulatory role in tissue revascularization.
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Parrott DL, Martin JM, Fischer AM. Analysis of barley (Hordeum vulgare) leaf senescence and protease gene expression: a family C1A cysteine protease is specifically induced under conditions characterized by high carbohydrate, but low to moderate nitrogen levels. New Phytol 2010; 187:313-331. [PMID: 20456047 DOI: 10.1111/j.1469-8137.2010.03278.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Senescence is the highly regulated last developmental phase of plant organs and tissues, and is optimized to allow nutrient remobilization to surviving plant parts, such as seeds of annual crops. High leaf carbohydrate to nitrogen (C : N) ratios have been implicated in the induction or acceleration of the senescence process. *A combination of phloem interruption in mature leaves (by steam-girdling, leading to carbohydrate accumulation from photosynthesis) and varied nitrate supply was used to analyse correlations between metabolite levels, leaf senescence parameters and induction of protease genes and proteolytic activities. *Its strong induction under conditions characterized by high C : N ratios, negative correlation of its transcript levels with chlorophylls and nitrates, its strong induction during developmental leaf senescence and its predicted localization to a lytic vacuolar compartment indicate that, among the genes tested, a family C1A cysteine protease is most likely to participate in bulk protein degradation during barley leaf senescence. *While all the genes analysed were selected based on upregulation during leaf senescence in a previous transcriptomic study, a considerably more detailed picture of protease gene regulation emerged from the data presented here, underlining the usefulness of this experimental approach for further (functional) protease characterization.
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Affiliation(s)
- David L Parrott
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
| | - John M Martin
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
| | - Andreas M Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
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Lacerenza JA, Parrott DL, Fischer AM. A major grain protein content locus on barley (Hordeum vulgare L.) chromosome 6 influences flowering time and sequential leaf senescence. J Exp Bot 2010; 61:3137-49. [PMID: 20525799 PMCID: PMC2892154 DOI: 10.1093/jxb/erq139] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 05/04/2023]
Abstract
Timing of various developmental stages including anthesis and whole-plant ('monocarpic') senescence influences yield and quality of annual crops. While a correlation between flowering/seed filling and whole-plant senescence has been observed in many annuals, it is unclear how the gene networks controlling these processes interact. Using near-isogenic germplasm, it has previously been demonstrated that a grain protein content (GPC) locus on barley chromosome 6 strongly influences the timing of post-anthesis flag leaf senescence, with high-GPC germplasm senescing early. Here, it is shown that the presence of high-GPC allele(s) at this locus also accelerates pre-anthesis plant development. While floral transition at the shoot apical meristem (SAM; determined by the presence of double ridges) occurred simultaneously, subsequent development was faster in the high- than in the low-GPC line, and anthesis occurred on average 5 d earlier. Similarly, sequential (pre-anthesis) leaf senescence was slightly accelerated, but only after differences in SAM development became visible. Leaf expression levels of four candidate genes (from a list of genes differentially regulated in post-anthesis flag leaves) were much higher in the high-GPC line even before faster development of the SAM became visible. One of these genes may be a functional homologue of Arabidopsis glycine-rich RNA-binding protein 7, which has previously been implicated in the promotion of flowering. Together, the data establish that the GPC locus influences pre- and post-anthesis barley development and senescence, and set the stage for a more detailed analysis of the interactions between the molecular networks controlling these important life history traits.
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Affiliation(s)
| | | | - Andreas M. Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
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35
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Darnige L, Helley D, Fischer AM, Emmerich J, Smadja DM, Fiessinger JN. Platelet microparticle levels: a biomarker of thromboangiitis obliterans (Buerger's disease) exacerbation. J Cell Mol Med 2010; 14:449-51. [PMID: 19818096 PMCID: PMC3837587 DOI: 10.1111/j.1582-4934.2009.00928.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2009] [Indexed: 11/21/2022] Open
Affiliation(s)
- L Darnige
- AP-HP, Höopital Européen Georges Pompidou, Service d’hématologie biologiqueParis, France
| | - D Helley
- AP-HP, Höopital Européen Georges Pompidou, Service d’hématologie biologiqueParis, France
- Université Paris DescartesParis, France
- Inserm U765, Faculté de PharmacieParis, France
| | - AM Fischer
- AP-HP, Höopital Européen Georges Pompidou, Service d’hématologie biologiqueParis, France
- Université Paris DescartesParis, France
- Inserm U765, Faculté de PharmacieParis, France
| | - J Emmerich
- Université Paris DescartesParis, France
- Inserm U765, Faculté de PharmacieParis, France
- AP-HP, Höopital Européen Georges Pompidou, Service de médecine vasculaire et HTA, Centre de référence des maladies rares vasculairesParis, France
| | - DM Smadja
- AP-HP, Höopital Européen Georges Pompidou, Service d’hématologie biologiqueParis, France
- Université Paris DescartesParis, France
- Inserm U765, Faculté de PharmacieParis, France
| | - JN Fiessinger
- Université Paris DescartesParis, France
- Inserm U765, Faculté de PharmacieParis, France
- AP-HP, Höopital Européen Georges Pompidou, Service de médecine vasculaire et HTA, Centre de référence des maladies rares vasculairesParis, France
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Abstract
Although an involvement of metabolic signals in the regulation of plant senescence has been demonstrated in a range of studies, the exact signalling pathways remain largely unresolved. For leaves, evidence supports a role of sugar accumulation in the initiation and/or acceleration of senescence. However, regulation of senescence or ageing may respond to different metabolic signals in heterotrophic plant organs and heterotrophic organisms. In animals and yeast, dietary restriction results in increased lifespan. In this article, the metabolic regulation of leaf senescence is compared with the effects of dietary restriction. Similarities and differences in the signalling pathways are discussed, including the role of autophagy, TOR (target of rapamycin), Sir2 (silent information regulator-2), and SnRK1 (sucrose non-fermenting-1-related protein kinase-1).
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Affiliation(s)
- Astrid Wingler
- Research Department of Genetics, Evolution and Environment, Darwin Building, University College London, Gower Street, London WC1E 6BT, UK.
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Heidlebaugh NM, Trethewey BR, Jukanti AK, Parrott DL, Martin JM, Fischer AM. Effects of a barley (Hordeum vulgare) chromosome 6 grain protein content locus on whole-plant nitrogen reallocation under two different fertilisation regimes. Funct Plant Biol 2008; 35:619-632. [PMID: 32688817 DOI: 10.1071/fp07247] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Accepted: 06/12/2008] [Indexed: 06/11/2023]
Abstract
A large fraction of protein N harvested with crop seeds is derived from N remobilisation from senescing vegetative plant parts, while a smaller fraction stems from de novo N assimilation occurring after anthesis. This study contrasts near-isogenic barley (Hordeum vulgare L.) germplasm, varying in the allelic state of a major grain protein content (GPC) locus on chromosome 6. Plant material was grown under both low- and high-N fertilisation levels. The analyses indicated that leaf N remobilisation occurred earlier in high-GPC germplasm under both fertilisation regimes, as indicated by an earlier decrease of total leaf N, chlorophylls, soluble- and membrane-proteins. At the same time, kernel free amino acid levels were enhanced, while leaf free amino acid levels were lower in high-GPC barleys, suggesting enhanced retranslocation of organic N to the developing sinks. Enhanced or longer availability of leaf nitrates was detected in high-GPC varieties and lines, at least under high N fertilisation, indicating that the GPC locus profoundly influences whole-plant N allocation and management. Results presented here, together with data from a recent transcriptomic analysis, make a substantial contribution to our understanding of whole-plant N storage, remobilisation and retranslocation to developing sinks.
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Affiliation(s)
- Nancy M Heidlebaugh
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
| | - Brian R Trethewey
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
| | - Aravind K Jukanti
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
| | - David L Parrott
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
| | - John M Martin
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
| | - Andreas M Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
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Myhajlenko S, Luby AS, Fischer AM, Ponce FA, Tracy C. SEM characterization of silicon nanostructures: can we meet the challenge? Scanning 2008; 30:310-316. [PMID: 18561254 DOI: 10.1002/sca.20115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The current semiconductor technology road map for device scaling champions a 4.5 nm gate length in production by 2022. The scanning electron microscope (SEM) as applied to critical dimensions (CD) metrology and associated characterization modes such as electron beam-induced current and cathodoluminescence (CL) has proved to be a workhorse for the semiconductor industry during the microelectronics era. We review some of the challenges facing these techniques in light of the silicon nanotechnology road map. We present some new results using voltage contrast imaging and CL spectroscopy of top-down fabricated silicon nanopillar/nanowires (<100 nm diameter), which highlight the visualization challenge. However, both techniques offer the promise of providing process characterization on the 10-20 nm scale with existing technology. Visualization at the 1 nm scale with these techniques may have to wait for aberration-corrected SEM to become more widely available. Basic secondary electron imaging and CD applications may be separately addressed by the He-ion microscope.
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Affiliation(s)
- S Myhajlenko
- Center for Solid State Electronics Research, Ira. A. Fulton School of Engineering, Arizona State University, Tempe, Arizona 85287, USA.
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Jukanti AK, Fischer AM. A high-grain protein content locus on barley (Hordeum vulgare) chromosome 6 is associated with increased flag leaf proteolysis and nitrogen remobilization. Physiol Plant 2008; 132:426-39. [PMID: 18333996 DOI: 10.1111/j.1399-3054.2007.01044.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Leaf senescence and nitrogen remobilization from senescing tissues are two important factors determining grain protein content (GPC) in cereals. We compared near-isogenic barley (Hordeum vulgare L.) germplasm varying in the allelic state of a major GPC quantitative trait locus on chromosome 6, delineated by molecular markers HVM74 and ABG458 and explaining approximately 46% of the variability in this trait. High GPC was consistently associated with earlier whole-plant senescence. SDS-PAGE and immunoblot analysis of flag leaf proteins indicated earlier leaf protein [including ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)] degradation in high-GPC germplasm. This was accompanied by enhanced availability of ammonium and glutamine in developing kernels, suggesting increased phloem retranslocation of nitrogen. Based on previous microarray analysis, we performed a detailed expression study of six leaf genes, tentatively involved in plastidial proteolysis, vacuolar proteolysis, intermediary N metabolism and N transport. All of these were upregulated in high-GPC barley, mostly around 21 to 28 days past anthesis, prior to or around the time demonstrating maximal differences in leaf protein (including Rubisco) levels. Therefore, these genes represent potential targets to manipulate grain protein accumulation. It appears likely that their functional analysis will enhance our understanding of whole-plant N recycling. Additionally, earlier leaf (photosynthetic) protein degradation may lead to reduced N carbon assimilation in high-GPC germplasm, explaining past studies demonstrating a negative correlation between GPC and yield.
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Affiliation(s)
- Aravind K Jukanti
- Department of Plant Sciences & Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
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Jukanti AK, Heidlebaugh NM, Parrott DL, Fischer IA, McInnerney K, Fischer AM. Comparative transcriptome profiling of near-isogenic barley (Hordeum vulgare) lines differing in the allelic state of a major grain protein content locus identifies genes with possible roles in leaf senescence and nitrogen reallocation. New Phytol 2008. [PMID: 18028296 DOI: 10.2307/4627269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
To identify genes involved in the regulation and execution of leaf senescence and whole-plant nitrogen reallocation, near-isogenic barley germplasm divergent in senescence timing and protein concentration of mature grains was contrasted. Barley lines differing in allelic state at a major locus on chromosome six, controlling grain protein concentration, were obtained after four generations of backcrossing. Based on physiological data indicating major differences between low- and high-grain protein germplasm at 14-21 d past anthesis, the flag leaf and kernel transcriptomes of the low-protein parent and one high-protein near-isogenic line were compared at these time points, using the 22-k Barley1 Affymetrix microarray. Our data associate several genes with both known (based on sequence comparisons) and unknown functions with the senescence process. These include leucine-rich repeat transmembrane protein kinases, a glycine-rich RNA-binding protein with homology to AtGRP7 and a 'mother of FT/TF1' gene. Our data also indicate upregulation of genes coding for both plastidial and extraplastidial proteases in germplasm with accelerated leaf senescence. Functional characterization of candidate genes identified by this research may contribute to our understanding of the molecular network underlying leaf senescence and nitrogen reallocation.
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Affiliation(s)
| | | | | | | | - Kate McInnerney
- Functional Genomics Core Facility, Montana State University, Bozeman, MT 59717, USA
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41
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Jukanti AK, Heidlebaugh NM, Parrott DL, Fischer IA, McInnerney K, Fischer AM. Comparative transcriptome profiling of near-isogenic barley (Hordeum vulgare) lines differing in the allelic state of a major grain protein content locus identifies genes with possible roles in leaf senescence and nitrogen reallocation. New Phytol 2008; 177:333-349. [PMID: 18028296 DOI: 10.1111/j.1469-8137.2007.02270.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
To identify genes involved in the regulation and execution of leaf senescence and whole-plant nitrogen reallocation, near-isogenic barley germplasm divergent in senescence timing and protein concentration of mature grains was contrasted. Barley lines differing in allelic state at a major locus on chromosome six, controlling grain protein concentration, were obtained after four generations of backcrossing. Based on physiological data indicating major differences between low- and high-grain protein germplasm at 14-21 d past anthesis, the flag leaf and kernel transcriptomes of the low-protein parent and one high-protein near-isogenic line were compared at these time points, using the 22-k Barley1 Affymetrix microarray. Our data associate several genes with both known (based on sequence comparisons) and unknown functions with the senescence process. These include leucine-rich repeat transmembrane protein kinases, a glycine-rich RNA-binding protein with homology to AtGRP7 and a 'mother of FT/TF1' gene. Our data also indicate upregulation of genes coding for both plastidial and extraplastidial proteases in germplasm with accelerated leaf senescence. Functional characterization of candidate genes identified by this research may contribute to our understanding of the molecular network underlying leaf senescence and nitrogen reallocation.
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Affiliation(s)
| | | | | | | | - Kate McInnerney
- Functional Genomics Core Facility, Montana State University, Bozeman, MT 59717, USA
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Parrott DL, McInnerney K, Feller U, Fischer AM. Steam-girdling of barley (Hordeum vulgare) leaves leads to carbohydrate accumulation and accelerated leaf senescence, facilitating transcriptomic analysis of senescence-associated genes. New Phytol 2007; 176:56-69. [PMID: 17803641 DOI: 10.1111/j.1469-8137.2007.02158.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Leaf senescence can be described as the dismantling of cellular components during a specific time interval before cell death. This has the effect of remobilizing N in the form of amino acids that can be relocalized to developing seeds. High levels of carbohydrates have previously been shown to promote the onset of the senescence process. Carbohydrate accumulation in barley (Hordeum vulgare) plants was induced experimentally by steam-girdling at the leaf base, occluding the phloem, and gene regulation under these conditions was investigated using the Affymetrix Barley GeneChip array and quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR). Transcript levels of plastidial (aminopeptidases, cnd41) and vacuolar (thiol and serine) proteases clearly increase in girdled leaves. Of special interest are cnd41, a plastidial aspartyl peptidase that has been implicated in Rubisco degradation in tobacco; and cp-mIII, a highly upregulated carboxypeptidase. SAG12, hexokinases and other senescence-specific genes are also upregulated under these conditions. Applying a genomic approach to the innovative experimental system described here significantly enhances our knowledge of leaf proteolysis and whole-plant N recycling.
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Affiliation(s)
| | - Kate McInnerney
- Functional Genomics Core Facility, Montana State University, Bozeman, MT 59717, USA
| | - Urs Feller
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
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de Raucourt E, Fischer AM, Meyer G, de Mazancourt P. A Bbeta 14 Arg --> Cys fibrinogen variant in a patient with thrombotic complications (fibrinogen St-Germain III). J Thromb Haemost 2006; 4:2722-3. [PMID: 17002657 DOI: 10.1111/j.1538-7836.2006.02240.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Jukanti AK, Bruckner PL, Fischer AM. Molecular and biochemical characterisation of polyphenol oxidases in developing kernels and senescing leaves of wheat (Triticum aestivum). Funct Plant Biol 2006; 33:685-696. [PMID: 32689277 DOI: 10.1071/fp06050] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Accepted: 05/02/2006] [Indexed: 06/11/2023]
Abstract
Polyphenol oxidases (PPOs) have been implicated in plant defence reactions. From an applied point of view, high PPO activity is associated with browning / darkening of fresh and processed food. Owing to its complex genome and economic importance, wheat (Triticum aestivum L.) represents an interesting system to advance our understanding of plant PPO function. We have previously shown that wheat PPOs are organised in a multigene family, consisting of two distinct phylogenetic clusters with three members each. In this study, we demonstrate that members of one cluster are not expressed in developing kernels or senescing flag leaves. Transcriptional regulation of one major gene in the other cluster largely controls PPO levels in these tissues, at least in the wheat varieties used for this study. Our data further indicate that the product of this gene is present as a latent enzyme during early kernel development, and that the latent enzyme is activated during later developmental phases. Enzyme activation can be achieved in vitro by limited tryptic digestion, but our data do not indicate activation by a proteolytic mechanism in vivo. Together, results presented in this study provide important insights into the regulation of wheat PPO function.
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Affiliation(s)
- Aravind K Jukanti
- Department of Plant Sciences and Plant Pathology, 119AgBioScience Facility, Montana State University, Bozeman, MT 59717-3150, USA
| | - Phil L Bruckner
- Department of Plant Sciences and Plant Pathology, 119AgBioScience Facility, Montana State University, Bozeman, MT 59717-3150, USA
| | - Andreas M Fischer
- Department of Plant Sciences and Plant Pathology, 119AgBioScience Facility, Montana State University, Bozeman, MT 59717-3150, USA
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Parrott D, Yang L, Shama L, Fischer AM. Senescence is accelerated, and several proteases are induced by carbon "feast" conditions in barley (Hordeum vulgare L.) leaves. Planta 2005; 222:989-1000. [PMID: 16034594 DOI: 10.1007/s00425-005-0042-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Accepted: 05/30/2005] [Indexed: 05/03/2023]
Abstract
Leaf senescence is characterized by nitrogen remobilization to developing seeds of annual plants, or surviving organs of perennial species. It has been demonstrated that high carbohydrate levels (carbon "feast") are associated with the onset of the senescence process. Therefore, the development of model systems allowing the manipulation of leaf carbohydrates constitutes a logical first step in the investigation of processes important during early phases of senescence, such as plastidial protein degradation. In this study, sugar accumulation was induced either by the incubation of excised, mature barley (Hordeum vulgare L.) leaves under relatively strong light, or by the interruption of sieve tubes at the base of the leaf lamina by "steam-girdling". Accelerated chlorophyll degradation and net proteolysis confirmed successful senescence induction in both model systems, but suggested that girdled leaves are more useful than excised leaves to study proteolysis. Activities or transcript levels of several proteolytic enzymes, including plastidial (aminopeptidases, Clp protease), cytosolic (proteasome) and vacuolar (thiol proteases, an aspartic protease and a serine carboxypeptidase) proteases were clearly induced under these conditions; some of these genes also reacted to other stimuli such as leaf excision. The most interesting finding was the specific induction of a carboxypeptidase gene (cp-mIII) in girdled leaves accumulating high carbohydrate levels. As a previous study from our laboratory, using a genetic approach, has indicated that one or several carboxypeptidases are involved in leaf N remobilization, the detailed characterization of cp-mIII (and, possibly, closely related genes) may considerably improve our understanding of whole-plant N recycling.
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Affiliation(s)
- D Parrott
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, 59717-3150, USA
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Murphy KA, Kuhle RA, Fischer AM, Anterola AM, Grimes HD. The functional status of paraveinal mesophyll vacuoles changes in response to altered metabolic conditions in soybean leaves. Funct Plant Biol 2005; 32:335-344. [PMID: 32689135 DOI: 10.1071/fp05006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2004] [Accepted: 03/04/2005] [Indexed: 06/11/2023]
Abstract
Antibodies raised against tonoplast intrinsic proteins (TIPs) were used to probe the functional status of the soybean [Glycine max (L.) Merr.] paraveinal mesophyll (PVM) vacuole during changes in nitrogen metabolism within the leaf. Young plants grown under standard conditions had PVM vacuoles characterised by the presence of γ-TIP, which is indicative of a lytic function. When plants were then subjected to shoot tip removal for a period of 15 d, forcing a sink-limited physiological condition, the γ-TIP marker diminished while the δ-TIP marker became present in the PVM vacuole, indicating the conversion of the PVM vacuole to a storage function. When the shoot tips were allowed to regrow, the γ-TIP marker again became dominant demonstrating the reversion of these PVM vacuoles back to a lytic compartment. The changes in TIP markers correlated with the accumulation of vegetative storage proteins and vegetative lipoxygenases, proteins implicated in nitrogen storage and assimilate partitioning. This research suggests that the PVM vacuole is able to undergo dynamic conversion between lytic and storage functions and further implicates this cell layer in assimilate storage and mobilisation in soybeans.
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Affiliation(s)
- Kimberly A Murphy
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164-6340, USA
| | - Rachel A Kuhle
- Graduate Program in Molecular Plant Sciences, Washington State University, Pullman, WA 99164-6340, USA
| | - Andreas M Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University-Bozeman, Bozeman, MT 59717-3150, USA
| | - Aldwin M Anterola
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164-6340, USA
| | - Howard D Grimes
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164-6340, USA
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Yang L, Mickelson S, See D, Blake TK, Fischer AM. Genetic analysis of the function of major leaf proteases in barley (Hordeum vulgare L.) nitrogen remobilization. J Exp Bot 2004; 55:2607-2616. [PMID: 15448176 DOI: 10.1093/jxb/erh267] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Most of the nitrogen harvested with the seeds of annual crops is remobilized and retranslocated within the plant between anthesis and plant death. While chloroplasts contain most of the reduced nitrogen present in photosynthetically active leaf cells, the (major) pathway(s) involved in the degradation of their proteins prior to the retranslocation of the resulting amino acids are unknown. In this study, a population of 146 recombinant inbred barley lines (RIL), derived from the cross between two varieties with a highly inheritable difference in grain protein concentration, was used to map quantitative trait loci (QTL) for leaf amino-, carboxy- and endopeptidase activities relative to previously determined QTL for grain protein, leaf N storage, and remobilization. The results strongly suggested that major endopeptidases, assayed at both acidic and slightly alkaline pH values (favouring vacuolar and extravacuolar enzymes, respectively) are not instrumental in leaf N remobilization or the control of grain protein accumulation. Similarly, QTL determined for aminopeptidases (relative to QTL for N remobilization) indicated no functional role for the enzyme(s) assayed in plant N recycling. By contrast, careful evaluation of QTL data suggested that one or several carboxypeptidase isoenzymes may be involved in this physiologically and economically important process. As these proteases (in contrast to aminopeptidases) have previously been localized in vacuoles, this result appears intriguing. These data, while shedding new light on an old problem, also indicate that the described approach may prove useful in evaluating the functional roles of additional (not assayed in this study) proteolytic systems in whole-plant nitrogen recycling.
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Affiliation(s)
- Litao Yang
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
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Affiliation(s)
- Aravind K. Jukanti
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150
| | - Phil L. Bruckner
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150
| | - Andreas M. Fischer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150
- Corresponding author. Phone: 406-994-5908. Fax: 406-994-7600. E-mail:
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Colliec-Jouault S, Zanchetta P, Helley D, Ratiskol J, Sinquin C, Fischer AM, Guezennec J. Les polysaccharides microbiens d’origine marine et leur potentiel en thérapeutique humaine. ACTA ACUST UNITED AC 2004; 52:127-30. [PMID: 15063931 DOI: 10.1016/j.patbio.2003.05.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2003] [Accepted: 05/20/2003] [Indexed: 11/21/2022]
Abstract
Bacterial polysaccharides offer fascinating potential applications for the pharmaceutical industry. Although many known marine bacteria produce exopolysaccharides (EPS), continuation in looking for new polysaccharide-producing micro-organisms is promising. Marine bacteria, isolated from deep-sea hydrothermal vents, have demonstrated their ability to produce in aerobic conditions, unusual EPS. With the aim of discovering biological activities, EPS presenting different structural features were studied. An EPS secreted by Vibrio diabolicus was evaluated on the restoration of bone integrity in experimental model and was demonstrated to be a strong bone-healing material. Another EPS produced by Alteromonas infernus was modified in order to obtain new heparin-like compounds. Unlike the native EPS, the resulting EPS presented anticoagulant properties as heparin. These EPS could provide biochemical entities with suitable functions for obtaining new drugs. They present original structural feature that can be modified to design compounds and improve their specificity.
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Affiliation(s)
- S Colliec-Jouault
- Laboratoire de biotechnologie et molécules marines (DRV/VP/BMM), Ifremer, rue de l'Ile-d'Yeu, BP 21105, 44311 Nantes cedex 3, France.
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Chabut D, Fischer AM, Helley D, Colliec S. Low molecular weight fucoidan promotes FGF-2-induced vascular tube formation by human endothelial cells, with decreased PAI-1 release and ICAM-1 downregulation. Thromb Res 2004; 113:93-5. [PMID: 15081570 DOI: 10.1016/j.thromres.2004.01.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2004] [Indexed: 11/24/2022]
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