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Advanced diffusion MRI provides evidence for altered axonal microstructure and gradual peritumoral infiltration in GBM in comparison to brain metastases. Clin Neuroradiol 2024:10.1007/s00062-024-01416-0. [PMID: 38683350 DOI: 10.1007/s00062-024-01416-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 04/15/2024] [Indexed: 05/01/2024]
Abstract
PURPOSE In contrast to peritumoral edema in metastases, GBM is histopathologically characterized by infiltrating tumor cells within the T2 signal alterations. We hypothesized that depending on the distance from the outline of the contrast-enhancing tumor we might reveal imaging evidence of gradual peritumoral infiltration in GBM and predominantly vasogenic edema around metastases. We thus investigated the gradual change of advanced diffusion metrics with the peritumoral zone in metastases and GBM. METHODS In 30 patients with GBM and 28 with brain metastases, peritumoral T2 hyperintensity was segmented in 33% partitions based on the total volume beginning at the enhancing tumor margin and divided into inner, middle and outer zones. Diffusion Tensor Imaging (DTI)-derived fractional anisotropy and mean diffusivity as well as Diffusion Microstructure Imaging (DMI)-based parameters Dax-intra, Dax-extra, V‑CSF and V-intra were employed to assess group-wise differences between inner and outer zones as well as within-group gradients between the inner and outer zones. RESULTS In metastases, fractional anisotropy and Dax-extra were significantly reduced in the inner zone compared to the outer zone (FA p = 0.01; Dax-extra p = 0.03). In GBM, we noted a reduced Dax-extra and significantly lower intraaxonal volume fraction (Dax-extra p = 0.008, V‑intra p = 0.006) accompanied by elevated axial intraaxonal diffusivity in the inner zone (p = 0.035). Between-group comparison of the outer to the inner zones revealed significantly higher gradients in metastases over GBM for FA (p = 0.04) as well as the axial diffusivity in the intra- (p = 0.02) and extraaxonal compartment (p < 0.001). CONCLUSION Our findings provide evidence of gradual alterations within the peritumoral zone of brain tumors. These are compatible with predominant (vasogenic) edema formation in metastases, whereas our findings in GBM are in line with an axonal destructive component in the immediate peritumoral area and evidence of tumor cell infiltration with accentuation in the tumor's vicinity.
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Raising patient voices in medical education: an assessment of patient perceived effect of social determinants of health conversations and the patient-physician relationship on quality of obstetric care, to inform the development of patient driven medical education curricula. FRONTIERS IN REPRODUCTIVE HEALTH 2024; 6:1283390. [PMID: 38435087 PMCID: PMC10905965 DOI: 10.3389/frph.2024.1283390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 02/06/2024] [Indexed: 03/05/2024] Open
Abstract
Background Conventional medical education lacks the lived experiences of patients which may authentically convey the social determinants of health (SDOH) and resulting health disparities. Videos of first-person patient narratives may prove a valuable education tool in this regard. The objective of this study is to investigate how patient demographics, satisfaction with care, and patient-physician relationships influence obstetric patient interest and willingness to contribute to a SDOH video curriculum by sharing their lived experiences through first-person narratives. Methods Study design included an anonymous, cross-sectional survey and an optional semi-structured telephone interview. Participants were 18 years old with a live-birth delivery <8 weeks prior to recruitment and received care during their pregnancy at Los Angeles General Medical Center (LAGMC). Variables surveyed included demographics, satisfaction with care, aspects of the patient-physician relationship, perceived utility, and personal interest in contributing to an educational SDOH video. A bivariate analysis was conducted to compare participants' characteristics and responses on interest in contributing and perceived helpfulness of first-person patient SDOH videos. Results 72.43% of participants (N = 70) believed a patient's first-person video on SDOH would be "Helpful" in preparing physicians to provide competent medical care; however, 71.43% responded "No" to "Interest" in sharing with physicians their experiences with SDOH. English preference and being U.S. born were factors significantly associated with viewing first-person SDOH video as "Helpful" (P > 0.001). Major themes from telephone interviews reflected enthusiasm for first-person patient narratives and perceived benefits of using patient experiences to educate physicians on SDOH. However, participants cited barriers to disclosing SDOH including brief and strictly clinical interactions with physicians, lack of continuity of care, and fear of being judged by physicians. Conclusion While most participants recognized the utility of addressing social needs in medical education and reported satisfaction with their obstetricians and care, these factors did not uniformly translate into willingness to contribute first-person patient narratives. To improve the representation of patients from racial, ethnic, gender, linguistic, and sexual minorities into medical curricula, further research and strategies are needed to overcome the barriers discouraging patient disclosure of social needs to physicians.
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Causes of Hypoxemia in COVID-19 Acute Respiratory Distress Syndrome: A Combined Multiple Inert Gas Elimination Technique and Dual-energy Computed Tomography Study. Anesthesiology 2024; 140:251-260. [PMID: 37656772 DOI: 10.1097/aln.0000000000004757] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/03/2023]
Abstract
BACKGROUND Despite the fervent scientific effort, a state-of-the art assessment of the different causes of hypoxemia (shunt, ventilation-perfusion mismatch, and diffusion limitation) in COVID-19 acute respiratory distress syndrome (ARDS) is currently lacking. In this study, the authors hypothesized a multifactorial genesis of hypoxemia and aimed to measure the relative contribution of each of the different mechanism and their relationship with the distribution of tissue and blood within the lung. METHODS In this cross-sectional study, the authors prospectively enrolled 10 patients with COVID-19 ARDS who had been intubated for less than 7 days. The multiple inert gas elimination technique (MIGET) and a dual-energy computed tomography (DECT) were performed and quantitatively analyzed for both tissue and blood volume. Variables related to the respiratory mechanics and invasive hemodynamics (PiCCO [Getinge, Sweden]) were also recorded. RESULTS The sample (51 ± 15 yr; Pao2/Fio2, 172 ± 86 mmHg) had a mortality of 50%. The MIGET showed a shunt of 25 ± 16% and a dead space of 53 ± 11%. Ventilation and perfusion were mismatched (LogSD, Q, 0.86 ± 0.33). Unexpectedly, evidence of diffusion limitation or postpulmonary shunting was also found. In the well aerated regions, the blood volume was in excess compared to the tissue, while the opposite happened in the atelectasis. Shunt was proportional to the blood volume of the atelectasis (R2 = 0.70, P = 0.003). V˙A/Q˙T mismatch was correlated with the blood volume of the poorly aerated tissue (R2 = 0.54, P = 0.016). The overperfusion coefficient was related to Pao2/Fio2 (R2 = 0.66, P = 0.002), excess tissue mass (R2 = 0.84, P < 0.001), and Etco2/Paco2 (R2 = 0.63, P = 0.004). CONCLUSIONS These data support the hypothesis of a highly multifactorial genesis of hypoxemia. Moreover, recent evidence from post-mortem studies (i.e., opening of intrapulmonary bronchopulmonary anastomosis) may explain the findings regarding the postpulmonary shunting. The hyperperfusion might be related to the disease severity. EDITOR’S PERSPECTIVE
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Protein signatures of spontaneous lipolysis and lipoprotein lipase activity in cow's milk. J Proteomics 2023; 285:104951. [PMID: 37321301 DOI: 10.1016/j.jprot.2023.104951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/17/2023]
Abstract
Spontaneous milk lipolysis refers to the breakdown of triacylglycerols in milk. Lipolysis impacts the organoleptic value of milk by causing off-flavours and reduces the technological properties of milk. Lipolysis is caused by lipoprotein lipase (LPL), a tightly regulated enzyme in milk. Our objective was to identify robust biomarkers of lipolysis and putative regulators of LPL enzyme in bovine milk. To achieve this goal, we used feed restriction as a lever to generate highly contrasted samples with regard to milk lipolysis. We combined statistical methods on proteomics data, milk lipolysis and LPL activity values. Following this strategy, we identified CD5L and GP2 as robust biomarkers of high lipolysis in cow milk. We also identified HID1, SURF4 and CUL9 as putative inhibitors of the lipolytic process in the milk. We thus proposed 5 putative biomarkers to be considered in future tools to manage milk lipolysis. SIGNIFICANCE: This manuscript is notable in three aspects. First, this is the first evaluation of the milk proteome relative to milk lipolysis or LPL activity. Second, the relationship between the abundance of proteins and milk traits was evaluated by a combination of univariate and multivariate analyses. Third, we provide a short list of five proteins to be tested in a larger population to feed the pipeline of biomarker discovery.
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Clinical feasibility of diffusion microstructure imaging (DMI) in acute ischemic stroke. Neuroimage Clin 2022; 36:103189. [PMID: 36126516 PMCID: PMC9486659 DOI: 10.1016/j.nicl.2022.103189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Diffusion microstructure imaging (DMI) is a fast approach to higher-order diffusion-weighted magnetic resonance imaging that allows robust decomposition and characterization of diffusion properties of brain tissue into intra-axonal, extra-axonal, and a free water-compartment. We now report the application of this technique to acute ischemic stroke and demonstrate its potential applicability to the daily clinical routine. METHODS Thirty-eight patients diagnosed with acute ischemic stroke were scanned using an accelerated multi-shell diffusion-weighted imaging protocol (median delay between onset and MRI scan of 113 min). DMI metrics were calculated and the apparent diffusion coefficient (ADC) derived from conventional diffusion-weighted imaging was used for comparison. The resulting DMI parameter maps were analysed for their potential to improve infarct core delineation, and a receiver-operating characteristic (ROC) analysis was subsequently performed for automated infarct segmentation. RESULTS Robust parameter maps for diffusion microstructure properties were obtained in all cases. Within the ischemic tissue, an increase in the volume fraction of the intra-axonal compartment was accompanied by a volume fraction reduction in the other two compartments. Moreover, diffusivity was reduced in all three compartments, with intra-axonal diffusivity showing the highest degree of contrast. The intra-axonal diffusion coefficient maps were subsequently found to perform better than single-shell ADC-derived segmentation in terms of automatic segmentation of the infarct core (area under the curve = 0.98 vs 0.92). CONCLUSIONS The alterations to the ischemic core detected by DMI are in line with the "beading-model" of non-uniform neurite swelling under ischemic conditions. When compared to conventional single-shell diffusion-weighted imaging, DMI metrics are associated with improved discriminative power for delineating and characterizing ischemic changes. This might allow a more detailed assessment of infarct age, severity of damage, the degree of reversibility, and outcome.
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Nigrostriatale Degeneration und Ansprechen auf Levodopa beim M. Parkinson, eine Studie mit Diffusions-Mikrostruktur-Bildgebung. ROFO-FORTSCHR RONTG 2022. [DOI: 10.1055/s-0042-1749866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Gray-White Matter Blurring of the Temporal Pole Associated With Hippocampal Sclerosis: A Microstructural Study Involving 3 T MRI and Ultrastructural Histopathology. Cereb Cortex 2021; 32:1882-1893. [PMID: 34515307 DOI: 10.1093/cercor/bhab320] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Hippocampal sclerosis (HS) is often associated with gray-white matter blurring (GMB) of the anterior temporal lobe. In this study, twenty patients with unilateral temporal lobe epilepsy and HS were studied with 3 T MRI including T1 MP2RAGE and DTI/DMI sequences. Anterior temporal lobe white matter T1 relaxation times and diffusion measures were analyzed on the HS side, on the contralateral side, and in 10 normal controls. Resected brain tissue of three patients without GMB and four patients with GMB was evaluated ultrastructurally regarding axon density and diameter, the relation of the axon diameter to the total fiber diameter (G-ratio), and the thickness of the myelin sheath. Hippocampal sclerosis GMB of the anterior temporal lobe was related to prolonged T1 relaxation and axonal loss. A less pronounced reduction in axonal fraction was also found on imaging in GMB-negative temporal poles compared with normal controls. Contralateral values did not differ significantly between patients and normal controls. Reduced axonal density and axonal diameter were histopathologically confirmed in the temporopolar white matter with GMB compared to temporal poles without. These results confirm that GMB can be considered an imaging correlate for disturbed axonal maturation that can be quantified with advanced diffusion imaging.
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Consistent Value of Two-Stage Pedicle Flaps in the Age of Microsurgical Maxillofacial Reconstruction. J Maxillofac Oral Surg 2021; 22:98-104. [PMID: 37041957 PMCID: PMC10082879 DOI: 10.1007/s12663-021-01635-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 08/10/2021] [Indexed: 11/29/2022] Open
Abstract
Abstract
Introduction
Up to the second half of the twentieth century, pedicled flaps marked the gold standard in reconstructive surgery. Followed by the introduction of microsurgical techniques, these flaps were increasingly abandoned. We conducted a retrospective study to determine the value of two-stage pedicle flaps in modern maxillofacial reconstruction.
Material & Methods
A chart review from October 2017 to November 2020 was performed to identify patients who were treated by a two-stage pedicle flap in our Department of Oral and Maxillofacial Surgery.
Results
A total of 31 patients, 17 female and 14 males received 36 two-stage pedicle flaps. All patients were in noticeably impaired health condition with a majority of ASA-score 3. The defect location mainly contained extraoral resections (58.3%). A variety of flaps were harvested consisting of buccal flaps, Abbe flaps, forehead flaps, deltopectoral flaps, nasolabial flaps, and a tubed flap.
Discussion
The study outlines two indications for the use of two-stage pedicle flaps. Firstly, as a back-up strategy in heavily pre-treated wound beds and secondly in an almost contrarily indication as a first-choice reconstructive option of the facial skin in esthetic demanding cases.
Conclusion
The timesaving and straight forward surgical approach as well as their low postsurgical complications and strong long-time success rates secure the two-stage pedicle flap a justified niche role in times of microsurgical maxillofacial reconstruction.
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Contrast Bolus Interference in a Multimodal CT Stroke Protocol. AJNR Am J Neuroradiol 2021; 42:1807-1814. [PMID: 34413063 DOI: 10.3174/ajnr.a7247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/21/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Whether CTP is performed before or after CTA varies within multimodal CT stroke protocols. CTA after CTP might show venous filling, and CTP metrics might be disturbed by prior CTA. Therefore, we compared CTP metrics conducted before and after CTA in a large cohort of patients with stroke and analyzed interferences of the CTA bolus with the CTP measurement. MATERIALS AND METHODS We analyzed 1980 patients (368 patients with CTP performed before CTA [group A] versus 1612 patients with CTP performed after [group B]) in a retrospective study. Mean curves, histograms of CTP baseline Hounsfield units, CBF, CBV, time-to-maximum, hypoperfusion, and core volumes were calculated using the software VEOcore. CTA and CTP interferences were analyzed, and a detection and correction method was proposed. RESULTS Mean CTP baseline values were significantly different in both groups (41 versus 45 HU within the groups A and B, respectively). However, perfusion metrics, hypoperfusion, and core volumes yielded no significant differences. In 49 patients, the descending flank of the CTA bolus interfered with the baseline of the CTP measurement, leading to erroneously low CBV values. These errors vanished when a correction method was applied. CONCLUSIONS CTP can be reliably performed after CTA without a relevant net effect on perfusion metrics. However, when measuring CTP after CTA, either a short pause on the order of 30 seconds should be observed or an appropriate correction method should be applied. It may help to avoid excluding patients from mechanical thrombectomy by overestimating infarct cores.
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X-ray quasi-periodic eruptions from two previously quiescent galaxies. Nature 2021; 592:704-707. [PMID: 33911275 PMCID: PMC8081662 DOI: 10.1038/s41586-021-03394-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/25/2021] [Indexed: 11/22/2022]
Abstract
Quasi-periodic eruptions (QPEs) are very-high-amplitude bursts of X-ray radiation recurring every few hours and originating near the central supermassive black holes of galactic nuclei1,2. It is currently unknown what triggers these events, how long they last and how they are connected to the physical properties of the inner accretion flows. Previously, only two such sources were known, found either serendipitously or in archival data1,2, with emission lines in their optical spectra classifying their nuclei as hosting an actively accreting supermassive black hole3,4. Here we report observations of QPEs in two further galaxies, obtained with a blind and systematic search of half of the X-ray sky. The optical spectra of these galaxies show no signature of black hole activity, indicating that a pre-existing accretion flow that is typical of active galactic nuclei is not required to trigger these events. Indeed, the periods, amplitudes and profiles of the QPEs reported here are inconsistent with current models that invoke radiation-pressure-driven instabilities in the accretion disk5–9. Instead, QPEs might be driven by an orbiting compact object. Furthermore, their observed properties require the mass of the secondary object to be much smaller than that of the main body10, and future X-ray observations may constrain possible changes in their period owing to orbital evolution. This model could make QPEs a viable candidate for the electromagnetic counterparts of so-called extreme-mass-ratio inspirals11–13, with considerable implications for multi-messenger astrophysics and cosmology14,15. X-ray quasi-periodic eruptions are detected from two previously inactive galaxies, with observations suggesting that the very-high-amplitude X-ray bursts may arise from an orbiting compact object.
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Timeline Of Hippocampal Atrophy Following Whole-Brain Radiation Therapy With And Without Hippocampus Avoidance. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Effect of dihydrotestosterone, 17-β-estrogen, genistein and equol on remodeling and morphology of bone in osteoporotic male rats during bone healing. Bone Rep 2020; 13:100300. [PMID: 32802919 PMCID: PMC7419585 DOI: 10.1016/j.bonr.2020.100300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 07/20/2020] [Accepted: 07/23/2020] [Indexed: 11/16/2022] Open
Abstract
Introduction The aim of this study was to investigate the effect of dihydrotestosterone (DHT), 17-β-estrogen (E2), genistein (GEN) and equol (EQ) on bone remodeling and bone morphology during healing of osteoporotic male rat tibiae. Materials and methods 180 Sprague-Dawley male rats were divided in 5 groups of 36 animals. After orchidectomy (ORX) and development of osteoporosis, trepanation of the tibia was performed. Until the time of trepanation all groups received soya free food (SF), then food change occurred and treatment started. At day 95, 102 and 151, samples were taken and histomorphometry was performed to analyze changes in bone structure under treatment. At day 33 and 70 all animals received calcein respective alizarin for polychrome bone labeling. Results The cortical bone was particularly affected. Treatment with DHT and E2 led to a significant long-term expansion of the thickness of the diaphyseal cortical bone, while the phytoestrogens EQ and GEN only had a positive short-term effect in this area. Only E2 preserved the trabecular bone for a limited time. In all groups, periosteal and endosteal bone areas showed the highest bone formation activity. The osteoporotic male injured bone shows a shift in mineral apposition rate (MAR) from periosteal to endosteal bone in the SF, DHT and E2 groups but not in the GEN and EQ phytohormones groups. An MAR decrease in trabecular bone formation was observed at day 70 in all groups except the E2 group. Conclusion We conclude from our results that healing of cortical bone defects in a rat model of male osteoporosis are mainly influenced by the estrogen pathway. Nevertheless, effects via purely androgenic mechanisms can also be demonstrated. The role of a phytohormone therapy is only marginal and if only useful for a short-term supportive approach. The role of the periosteal to endosteal shift during male osteoporotic bone healing needs to be further examined. The estrogen pathway is leading in the healing osteoporotic male rat bone. Osteoporotic rat bone has the highest apposition rate in the periosteal area. Healing increases periosteal, endosteal and decreases trabecular bone formation. The highest apposition rate shifts from periosteal to endosteal bone during healing. Testosterone as a drug could harness positive estrogenic and androgenic effects.
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Chicken adaptive response to low energy diet: main role of the hypothalamic lipid metabolism revealed by a phenotypic and multi-tissue transcriptomic approach. BMC Genomics 2019; 20:1033. [PMID: 31888468 PMCID: PMC6937963 DOI: 10.1186/s12864-019-6384-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 12/11/2019] [Indexed: 02/07/2023] Open
Abstract
Background Production conditions of layer chicken can vary in terms of temperature or diet energy content compared to the controlled environment where pure-bred selection is undertaken. The aim of this study was to better understand the long-term effects of a 15%-energy depleted diet on egg-production, energy homeostasis and metabolism via a multi-tissue transcriptomic analysis. Study was designed to compare effects of the nutritional intervention in two layer chicken lines divergently selected for residual feed intake. Results Chicken adapted to the diet in terms of production by significantly increasing their feed intake and decreasing their body weight and body fat composition, while their egg production was unchanged. No significant interaction was observed between diet and line for the production traits. The low energy diet had no effect on adipose tissue and liver transcriptomes. By contrast, the nutritional challenge affected the blood transcriptome and, more severely, the hypothalamus transcriptome which displayed 2700 differentially expressed genes. In this tissue, the low-energy diet lead to an over-expression of genes related to endocannabinoid signaling (CN1R, NAPE-PLD) and to the complement system, a part of the immune system, both known to regulate feed intake. Both mechanisms are associated to genes related polyunsaturated fatty acids synthesis (FADS1, ELOVL5 and FADS2), like the arachidonic acid, a precursor of anandamide, a key endocannabinoid, and of prostaglandins, that mediate the regulatory effects of the complement system. A possible regulatory role of NR1H3 (alias LXRα) has been associated to these transcriptional changes. The low-energy diet further affected brain plasticity-related genes involved in the cholesterol synthesis and in the synaptic activity, revealing a link between nutrition and brain plasticity. It upregulated genes related to protein synthesis, mitochondrial oxidative phosphorylation and fatty acid oxidation in the hypothalamus, suggesting reorganization in nutrient utilization and biological synthesis in this brain area. Conclusions We observed a complex transcriptome modulation in the hypothalamus of chicken in response to low-energy diet suggesting numerous changes in synaptic plasticity, endocannabinoid regulation, neurotransmission, lipid metabolism, mitochondrial activity and protein synthesis. This global transcriptomic reprogramming could explain the adaptive behavioral response (i.e. increase of feed intake) of the animals to the low-energy content of the diet.
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Mechanical Ventilation Strategies Targeting Different Magnitudes of Collapse and Tidal Recruitment in Porcine Acid Aspiration-Induced Lung Injury. J Clin Med 2019; 8:jcm8081250. [PMID: 31426607 PMCID: PMC6722815 DOI: 10.3390/jcm8081250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/06/2019] [Accepted: 08/14/2019] [Indexed: 12/29/2022] Open
Abstract
Reducing ventilator-associated lung injury by individualized mechanical ventilation (MV) in patients with Acute Respiratory Distress Syndrome (ARDS) remains a matter of research. We randomly assigned 27 pigs with acid aspiration-induced ARDS to three different MV protocols for 24 h, targeting different magnitudes of collapse and tidal recruitment (collapse&TR): the ARDS-network (ARDSnet) group with low positive end-expiratory pressure (PEEP) protocol (permissive collapse&TR); the Open Lung Concept (OLC) group, PaO2/FiO2 >400 mmHg, indicating collapse&TR <10%; and the minimized collapse&TR monitored by Electrical Impedance Tomography (EIT) group, standard deviation of regional ventilation delay, SDRVD. We analyzed cardiorespiratory parameters, computed tomography (CT), EIT, and post-mortem histology. Mean PEEP over post-randomization measurements was significantly lower in the ARDSnet group at 6.8 ± 1.0 cmH2O compared to the EIT (21.1 ± 2.6 cmH2O) and OLC (18.7 ± 3.2 cmH2O) groups (general linear model (GLM) p < 0.001). Collapse&TR and SDRVD, averaged over all post-randomization measurements, were significantly lower in the EIT and OLC groups than in the ARDSnet group (collapse p < 0.001, TR p = 0.006, SDRVDp < 0.004). Global histological diffuse alveolar damage (DAD) scores in the ARDSnet group (10.1 ± 4.3) exceeded those in the EIT (8.4 ± 3.7) and OLC groups (6.3 ± 3.3) (p = 0.16). Sub-scores for edema and inflammation differed significantly (ANOVA p < 0.05). In a clinically realistic model of early ARDS with recruitable and nonrecruitable collapse, mechanical ventilation involving recruitment and high-PEEP reduced collapse&TR and resulted in improved hemodynamic and physiological conditions with a tendency to reduced histologic lung damage.
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Accuracy of Navigation-Guided Dental Implant Placement with Screw Versus Hand Template Fixation in the Edentulous Mandible. Int J Oral Maxillofac Implants 2018. [PMID: 29534126 DOI: 10.11607/jomi.5784] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Preoperative planning of the implant position as part of a coordinated prosthetic and surgical concept is becoming increasingly important regarding function and esthetics. The aim of this study was to investigate the transmission accuracy of template fixation during surgery in edentulous arches with hand fixation in comparison to intermediary screw fixation. MATERIALS AND METHODS Preoperatively, 10 implant positions were planned using computed tomography (CT) with the system med3D for implant placement in four mandible models of the Goettingen study model, using a prosthetic diagnostic template. A total of 40 implant insertions were created. For every 20 insertions, the template was temporarily fixed with three screws and compared with the insertion using a hand-fixed template. The precision of the transmission was evaluated with and without screw fixation by re-evaluating the preimplant planning with additional CT scanning of the respective models. RESULTS Compared with the hand-fixed procedure (HFG) in the model situation, there were no significant differences between the deviations of planned and final implant position in the screw-fixed group (FG). According to the study results, the fixed procedure leads to less depth deviation and lateral error of the implant base in relation to the HFG. Within both groups, there were significant differences between the radial deviation tendencies from the implant base to the implant apex (P = .033 for FG and P = .001 for HFG). CONCLUSION The use of CT-based implant planning succeeds in fixed and hand-fixed surgical procedures with high precision in the atrophic, edentulous mandible model. According to the results of this study, in cases demanding high depth precision, screw-fixation of the template can be helpful.
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Immunome differences between porcine ileal and jejunal Peyer's patches revealed by global transcriptome sequencing of gut-associated lymphoid tissues. Sci Rep 2018; 8:9077. [PMID: 29899562 PMCID: PMC5998120 DOI: 10.1038/s41598-018-27019-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 05/18/2018] [Indexed: 01/09/2023] Open
Abstract
The epithelium of the intestinal mucosa and the gut-associated lymphoid tissues (GALT) constitute an essential physical and immunological barrier against pathogens. In order to study the specificities of the GALT transcriptome in pigs, we compared the transcriptome profiles of jejunal and ileal Peyer’s patches (PPs), mesenteric lymph nodes (MLNs) and peripheral blood (PB) of four male piglets by RNA-Seq. We identified 1,103 differentially expressed (DE) genes between ileal PPs (IPPs) and jejunal PPs (JPPs), and six times more DE genes between PPs and MLNs. The master regulator genes FOXP3, GATA3, STAT4, TBX21 and RORC were less expressed in IPPs compared to JPPs, whereas the transcription factor BCL6 was found more expressed in IPPs. In comparison between IPPs and JPPs, our analyses revealed predominant differential expression related to the differentiation of T cells into Th1, Th2, Th17 and iTreg in JPPs. Our results were consistent with previous reports regarding a higher T/B cells ratio in JPPs compared to IPPs. We found antisense transcription for respectively 24%, 22% and 14% of the transcripts detected in MLNs, PPs and PB, and significant positive correlations between PB and GALT transcriptomes. Allele-specific expression analyses revealed both shared and tissue-specific cis-genetic control of gene expression.
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Stigma as a barrier to the use of occupational health units for tuberculosis services in South Africa. Int J Tuberc Lung Dis 2018; 21:75-80. [PMID: 29025488 DOI: 10.5588/ijtld.17.0030] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Tuberculosis (TB) is the leading cause of death in South Africa, and health care workers (HCWs) are disproportionally affected. The resulting absenteeism strains the already overburdened health system. Although hospital occupational health care units (OHUs) are cost-effective and of crucial importance in tackling the TB epidemic, the fear of being stigmatised by other colleagues might lead HCWs to avoid using OHUs. OBJECTIVE To investigate whether the perception of TB stigma among colleagues has a negative effect on the willingness to use OHUs for TB services. DESIGN In the Free State Province, South Africa, a representative sample of 804 HCWs from six hospitals were surveyed on workplace stigma as a predictor for the use of OHUs for TB services. Applying structural equation modelling, we also controlled for exogenous variables. RESULTS There was a significant negative relationship between the perception of stigmatising attitudes and behaviours among co-workers and the use of OHUs for TB screening (β -0.21, P = 0.000), treatment (β -0.16, P = 0.001) and isoniazid preventive therapy (β -0.17, P = 0.000). CONCLUSION The negative effect of TB stigma on OHU use among HCWs can impact upon their health and increase hospital costs. This needs to be addressed by interventions combating TB stigma among HCWs in the workplace.
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Measuring HIV- and TB-related stigma among health care workers in South Africa: a validation and reliability study. Int J Tuberc Lung Dis 2018; 21:19-25. [PMID: 29025481 DOI: 10.5588/ijtld.16.0749] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Recent evidence indicates that human immunodeficiency virus (HIV) and tuberculosis (TB) related stigma act as a key barrier to the utilisation of associated occupational health services by South African health care workers (HCWs). It also highlights a dearth of appropriate tools to measure HIV and TB stigma among HCWs. OBJECTIVE To test four scales measuring different aspects of stigma: respondent's external stigma (RES) and others' external stigma (OES) towards TB as well as HIV across different professional categories of HCWs. DESIGN The current study employs data from a study on HIV and TB stigma among HCWs, a cluster randomised controlled trial for the collection of data among 882 HCWs in the Free State Province of South Africa. Confirmatory factor analyses and structural equation modelling were used to assess the validity and reliability of the scales. RESULTS All four scales displayed adequate internal construct validity. Subsequent analysis demonstrated that all four scales were metric-invariant, and that the OES scales were even scalar-invariant across patient and support staff groups. The scales displayed good reliability and external construct validity. CONCLUSION Our results support the use of the scales developed to measure TB and HIV stigma among HCWs. Further research is, however, needed to fine tune the instruments and test them across different resource-limited countries.
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P3005 Genome-wide transcriptomic analysis of liver in sex-linked dwarf and wild-type chickens. J Anim Sci 2016. [DOI: 10.2527/jas2016.94supplement453x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Clinical efficacy of grafting materials in alveolar ridge augmentation: A systematic review. J Craniomaxillofac Surg 2016; 44:1618-1629. [PMID: 27622971 DOI: 10.1016/j.jcms.2016.07.028] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 06/22/2016] [Accepted: 07/29/2016] [Indexed: 12/29/2022] Open
Abstract
PURPOSE To evaluate the efficacy of grafting materials in lateral and vertical ridge augmentations. MATERIALS AND METHODS A systematic review of the literature on the clinical use of grafting materials of the years 1995 to April 2015 was conducted using electronic search of PubMed and Cochrane libraries and hand search of eight print journals. A total of 184 papers were included, comprising 6182 patients. Parameters evaluated were observation period [months], bone formation [histologic area%], defect fill [%], horizontal and vertical gain [mm], loss of augmented volume [mm], complication rate [%], and implant survival rate [%]. Results are expressed as weighted means ± SD. RESULTS Results were obtained after a weighted mean observation period of 27.4 months (range 3-168 months). Bone formation in the augmented areas varied from 33.2 ± 14.9% for allogeneic grafts to 56.0 ± 25.6% for mixtures of autogenous and other grafting materials. Defect fill in dehiscence defects ranged from 51.0 ± 13.6% (synthetic) to 85.8 ± 13.4% (xenogeneic) for the different materials, with an overall weighted mean of 79.8 ± 18.7%. Weighted mean horizontal gain for all particulate grafting materials was 3.7 ± 1.2 mm, with variation between 2.2 ± 1.2 mm (synthetic) and 4.5 ± 1.0 mm (mixtures of autogenous bone with allogeneic/xenogeneic grafting material) without statistical significance. Weighted overall mean vertical gain was 3.7 ± 1.4 mm. Vertical gain was substantially higher when space-making barrier materials such as titanium meshes were used; however this was also associated with strong increase in complication rate. Block grafts achieved higher horizontal gain by approximately 1 mm. The use of block grafts achieved significantly increased vertical gain compared to particulate material only when autogenous block grafts from extraoral donor sites were used. CONCLUSION Horizontal and vertical gain by 3.7 mm on average can be achieved using particulate materials. This can be increased by using titanium meshes. Substantial vertical gains beyond this dimension require the use of extraoral bone block grafts.
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SY17-2ADOLESCENT SOCIAL ISOLATION AS A MODEL OF ALCOHOL ADDICTION VULNERABILITY. Alcohol Alcohol 2015. [DOI: 10.1093/alcalc/agv076.71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Analysis of computer-aided techniques for virtual planning in nasoalveolar moulding. Br J Oral Maxillofac Surg 2015; 53:455-60. [DOI: 10.1016/j.bjoms.2015.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 03/05/2015] [Indexed: 11/26/2022]
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Moderate alcohol consumption enhances vaccine-induced responses in rhesus macaques. Vaccine 2013; 32:54-61. [PMID: 24200973 DOI: 10.1016/j.vaccine.2013.10.076] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 08/28/2013] [Accepted: 10/23/2013] [Indexed: 12/14/2022]
Abstract
We have recently shown that chronic alcohol consumption in a rhesus macaque model of ethanol self-administration significantly modulates the serum cytokine profile. In this study, we extended these observations by investigating the impact of chronic ethanol exposure on the immune response to Modified Vaccinia Ankara (MVA). All animals were vaccinated with MVA before ethanol exposure to ethanol and then again after 7 months of 22 h/day of "open-access" drinking of 4% (w/v) ethanol. Our results indicate that animals whose blood ethanol concentration (BEC) chronically exceeded 80 mg/dl had lower CD4 and CD8 T cell proliferation as well as IgG responses following MVA booster than control animals. In contrast, relatively moderate drinkers whose BEC remained below 80 mg/ml exhibited more robust MVA-specific IgG and CD8 T cell responses than controls. To begin to uncover mechanisms underlying the differences in MVA-specific responses between the three groups, we analyzed plasma cytokine levels and microRNA expression in peripheral blood mononuclear cells following MVA booster. Our findings suggest that moderate ethanol consumption results in higher levels of antiviral cytokines and an expression profile of microRNAs linked to CD8 T cell differentiation. In summary, moderate alcohol consumption enhances recall vaccine responses, whereas chronic alcohol intoxication suppresses this response.
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ansa-Zirconocenes with Bridge-tethered Donors: Synthesis and Application as Catalysts in Solution Polymerization of Ethylene. Chem Eng Technol 2013. [DOI: 10.1002/ceat.201200393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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The Imprint of the Extragalactic Background Light in the Gamma-Ray Spectra of Blazars. Science 2012; 338:1190-2. [DOI: 10.1126/science.1227160] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Extrapolation in the analysis of lung aeration by computed tomography: a validation study. Crit Care 2011; 15:R279. [PMID: 22112625 PMCID: PMC3388635 DOI: 10.1186/cc10563] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Revised: 10/10/2011] [Accepted: 11/23/2011] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Computed tomography (CT) is considered the gold standard for quantification of global or regional lung aeration and lung mass. Quantitative CT, however, involves the exposure to ionizing radiation and requires manual image processing. We recently evaluated an extrapolation method which calculates quantitative CT parameters characterizing the entire lung from only 10 reference CT-slices thereby reducing radiation exposure and analysis time. We hypothesized that this extrapolation method could be further validated using CT-data from pigs and sheep, which have a different thoracic anatomy. METHODS We quantified volume and mass of the total lung and differently aerated lung compartments in 168 ovine and 55 porcine whole-lung CTs covering lung conditions from normal to gross deaeration. Extrapolated volume and mass parameters were compared to the respective values obtained by whole-lung analysis. We also tested the accuracy of extrapolation for all possible numbers of CT slices between 15 and 5. Bias and limits of agreement (LOA) were analyzed by the Bland-Altman method. RESULTS For extrapolation from 10 reference slices, bias (LOA) for the total lung volume and mass of sheep were 18.4 (-57.2 to 94.0) ml and 4.2 (-21.8 to 30.2) grams, respectively. The corresponding bias (LOA) values for pigs were 5.1 (-55.2 to 65.3) ml and 1.6 (-32.9 to 36.2) grams, respectively. All bias values for differently aerated lung compartments were below 1% of the total lung volume or mass and the LOA never exceeded ± 2.5%. Bias values diverged from zero and the LOA became considerably wider when less than 10 reference slices were used. CONCLUSIONS The extrapolation method appears robust against variations in thoracic anatomy, which further supports its accuracy and potential usefulness for clinical and experimental application of quantitative CT.
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Computed tomographic assessment of lung weights in trauma patients with early posttraumatic lung dysfunction. Crit Care 2011; 15:R71. [PMID: 21352529 PMCID: PMC3222004 DOI: 10.1186/cc10060] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 01/31/2011] [Accepted: 02/25/2011] [Indexed: 11/10/2022] Open
Abstract
Introduction Quantitative computed tomography (qCT)-based assessment of total lung weight (Mlung) has the potential to differentiate atelectasis from consolidation and could thus provide valuable information for managing trauma patients fulfilling commonly used criteria for acute lung injury (ALI). We hypothesized that qCT would identify atelectasis as a frequent mimic of early posttraumatic ALI. Methods In this prospective observational study, Mlung was calculated by qCT in 78 mechanically ventilated trauma patients fulfilling the ALI criteria at admission. A reference interval for Mlung was derived from 74 trauma patients with morphologically and functionally normal lungs (reference). Results are given as medians with interquartile ranges. Results The ratio of arterial partial pressure of oxygen to the fraction of inspired oxygen was 560 (506 to 616) mmHg in reference patients and 169 (95 to 240) mmHg in ALI patients. The median reference Mlung value was 885 (771 to 973) g, and the reference interval for Mlung was 584 to 1164 g, which matched that of previous reports. Despite the significantly greater median Mlung value (1088 (862 to 1,342) g) in the ALI group, 46 (59%) ALI patients had Mlung values within the reference interval and thus most likely had atelectasis. In only 17 patients (22%), Mlung was increased to the range previously reported for ALI patients and compatible with lung consolidation. Statistically significant differences between atelectasis and consolidation patients were found for age, Lung Injury Score, Glasgow Coma Scale score, total lung volume, mass of the nonaerated lung compartment, ventilator-free days and intensive care unit-free days. Conclusions Atelectasis is a frequent cause of early posttraumatic lung dysfunction. Differentiation between atelectasis and consolidation from other causes of lung damage by using qCT may help to identify patients who could benefit from management strategies such as damage control surgery and lung-protective mechanical ventilation that focus on the prevention of pulmonary complications.
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Case Report: Endokrine Therapie bei Lymphangioleiomyomatose. Geburtshilfe Frauenheilkd 2010. [DOI: 10.1055/s-0030-1254960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Results of monitoring fasciocutaneous, myocutaneous, osteocutaneous and perforator flaps: 4-year experience with 166 cases. Int J Oral Maxillofac Surg 2010; 39:21-8. [DOI: 10.1016/j.ijom.2009.10.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 06/15/2009] [Accepted: 10/12/2009] [Indexed: 11/27/2022]
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Verdacht auf sexuellen Missbrauch bei Mädchen und deren Abklärung an der Universitätsfrauenklinik Wien im Jahr 2008. Geburtshilfe Frauenheilkd 2009. [DOI: 10.1055/s-0029-1225243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Einfluss einer präfrontalen 1Hz-rTMS auf ereigniskorrelierte Potenziale einer GoNogo-Aufgabe. KLIN NEUROPHYSIOL 2009. [DOI: 10.1055/s-0029-1216179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Theta burst stimulation of the prefrontal cortex: Safety data and effects on cognition and resting EEG. Brain Stimul 2008. [DOI: 10.1016/j.brs.2008.06.156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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An extremely luminous X-ray outburst at the birth of a supernova. Nature 2008; 453:469-74. [PMID: 18497815 DOI: 10.1038/nature06997] [Citation(s) in RCA: 352] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Accepted: 04/04/2008] [Indexed: 11/09/2022]
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An unusually brilliant transient in the galaxy M85. Nature 2007; 447:458-60. [PMID: 17522679 DOI: 10.1038/nature05822] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Accepted: 03/30/2007] [Indexed: 11/09/2022]
Abstract
Historically, variable and transient sources have both surprised astronomers and provided new views of the heavens. Here we report the discovery of an optical transient in the outskirts of the lenticular galaxy Messier 85 in the Virgo cluster. With a peak absolute R magnitude of -12, this event is distinctly brighter than novae, but fainter than type Ia supernovae (which are expected in a population of old stars in lenticular galaxies). Archival images of the field do not show a luminous star at that position with an upper limit in the g filter of about -4.1 mag, so it is unlikely to be a giant eruption from a luminous blue variable star. Over a two-month period, the transient source emitted radiation energy of almost 10(47) erg and subsequently faded in the optical sky. It is similar to, but six times more luminous at peak than, an enigmatic transient in the galaxy M31 (ref. 1). A possible origin of M85 OT2006-1 is a stellar merger. If so, searches for similar events in nearby galaxies will not only allow study of the physics of hyper-Eddington sources, but also probe an important phase in the evolution of stellar binary systems.
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Relativistic ejecta from X-ray flash XRF 060218 and the rate of cosmic explosions. Nature 2006; 442:1014-7. [PMID: 16943832 DOI: 10.1038/nature05087] [Citation(s) in RCA: 383] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Accepted: 07/13/2006] [Indexed: 11/09/2022]
Abstract
Over the past decade, long-duration gamma-ray bursts (GRBs)--including the subclass of X-ray flashes (XRFs)--have been revealed to be a rare variety of type Ibc supernova. Although all these events result from the death of massive stars, the electromagnetic luminosities of GRBs and XRFs exceed those of ordinary type Ibc supernovae by many orders of magnitude. The essential physical process that causes a dying star to produce a GRB or XRF, and not just a supernova, is still unknown. Here we report radio and X-ray observations of XRF 060218 (associated with supernova SN 2006aj), the second-nearest GRB identified until now. We show that this event is a hundred times less energetic but ten times more common than cosmological GRBs. Moreover, it is distinguished from ordinary type Ibc supernovae by the presence of 10(48) erg coupled to mildly relativistic ejecta, along with a central engine (an accretion-fed, rapidly rotating compact source) that produces X-rays for weeks after the explosion. This suggests that the production of relativistic ejecta is the key physical distinction between GRBs or XRFs and ordinary supernovae, while the nature of the central engine (black hole or magnetar) may distinguish typical bursts from low-luminosity, spherical events like XRF 060218.
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Abstract
BACKGROUND Staphylococcal colonization may influence the course of allergic diseases such as atopic dermatitis or allergic rhinitis. The frequency of Staphylococcus aureus (SA) nasal carriage and its possible influence on persistent allergic rhinitis was investigated. METHODS In nasal lavages from 22 patients with house dust mite allergy and 18 healthy controls, the number of SA colony forming units per ml were assessed and related to nasal symptom scores, the concentrations of three inflammatory cell activation markers, nasal total IgE and 17 cytokines in nasal secretions. RESULTS SA was found in 15/22 allergic patients and 4/18 controls (P < 0.01). Comparing allergic SA carriers with allergic noncarriers, nasal symptom scores tended to be higher (P < 0.1), and the cell activation markers ECP (10(2.23+/-0.33)vs 10(1.45+/-0.50) ng/ml; P < 0.05) and elastase (10(2.70+/-0.21)vs 10(2.12+/-0.34) ng/ml; P < 0.01), and nasal total IgE-levels (10(1.66+/-0.38)vs 10(1.2+/-0.28) kU/ml; P < 0.05) were significantly higher in allergic SA carriers. Nasal SA carriers had a higher nasal IL-13/IFN-gamma ratio (P < 0.01), and this was correlated with higher nasal total IgE in allergic patients (r = 0.6, P < 0.05). CONCLUSION Nasal SA carriage is frequent in patients with persistent allergic rhinitis. The data of this study suggest that they are not only secondary bystanders, but actively modulate the disease by promoting local IgE production.
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Simultanes nichtinvasives Monitoring mit Laser-Doppler-Flussmessung und Gewebespektrometrie bei fasziokutanen Radialislappen und osteokutanen Fibulatransplantaten. ACTA ACUST UNITED AC 2005; 9:290-9. [PMID: 16133280 DOI: 10.1007/s10006-005-0636-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
AIM In the literature currently available monitoring devices are usually divided into two major groups: those for monitoring perfusion and those for measuring tissue oxygenation. The O(2)C (oxygen to see) system combines these two ways of monitoring free flap viability. The aim of this prospective study was to determine the necessity of flap revision and when unnecessary revision can be avoided. Another point of interest was the question of whether critical values for the successful course of free flaps could be defined and in addition whether such values would differ for different flap types. PATIENTS AND METHODS In a prospective study 82 free flaps (61 radial forearm flaps and 21 fibula flaps) were monitored with the O(2)C monitoring unit. Measurements were carried out intraoperatively and postoperatively up to 14 days. RESULTS Perfusion compromise occurred in 12 (14.6%) of 82 monitored free flaps. Operative exploration was performed in seven cases, in five of them successfully. Five flaps (three radial forearm and two fibula flaps) were lost due to vascular compromise, which led to an overall success rate of 93.4%. Venous congestion was identified by a rapid increase in hemoglobin concentration of more than 30%. An abrupt decline of blood flow and hemoglobin oxygenation indicated arterial occlusion. Vascular complications were detected in all cases prior to clinical assessment with no false positive or negative results. For radial forearm flaps a hemoglobin oxygenation of 15%, a superficial flow of 10 AU, and a deep flow of 20 AU were identified as minimum values for flap viability. For fibula flaps a hemoglobin oxygenation of 10%, a superficial flow of 5 AU, and a deep flow of 15 AU were determined as minimum values. CONCLUSION O(2)C combines laser Doppler flowmetry and tissue spectrophotometry and for the first time allows simultaneous measurement of the microcirculatory parameters including blood flow, flow velocity, hemoglobin concentration, and hemoglobin oxygenation. We found this new noninvasive technique to be a reliable and accurate method for evaluating flap viability and improving the success rate in free flap transfer.
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Deckung allschichtiger Schädeldefekte mit freiem chimären osteomyokutanen M. serratus anterior-Lappen mit halben Rippen (7 Fälle). HANDCHIR MIKROCHIR P 2005. [DOI: 10.1055/s-2005-864882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Salvage Operationen unter Einsatz verschiedener mikrochirurgischer Techniken zur Behandlung von Komplikationen nach Wirbelsäuleneingriffen. HANDCHIR MIKROCHIR P 2005. [DOI: 10.1055/s-2005-864881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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An exceptionally bright flare from SGR 1806–20 and the origins of short-duration γ-ray bursts. Nature 2005; 434:1098-103. [PMID: 15858565 DOI: 10.1038/nature03519] [Citation(s) in RCA: 435] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Accepted: 03/04/2005] [Indexed: 11/08/2022]
Abstract
Soft-gamma-ray repeaters (SGRs) are galactic X-ray stars that emit numerous short-duration (about 0.1 s) bursts of hard X-rays during sporadic active periods. They are thought to be magnetars: strongly magnetized neutron stars with emissions powered by the dissipation of magnetic energy. Here we report the detection of a long (380 s) giant flare from SGR 1806-20, which was much more luminous than any previous transient event observed in our Galaxy. (In the first 0.2 s, the flare released as much energy as the Sun radiates in a quarter of a million years.) Its power can be explained by a catastrophic instability involving global crust failure and magnetic reconnection on a magnetar, with possible large-scale untwisting of magnetic field lines outside the star. From a great distance this event would appear to be a short-duration, hard-spectrum cosmic gamma-ray burst. At least a significant fraction of the mysterious short-duration gamma-ray bursts may therefore come from extragalactic magnetars.
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Anwendung von homogenen methylalumoxanfreien Katalysatorsystemen zur Synthese von Ethylen/1-Olefin-Copolymeren im Hochdruckprozeß. CHEM-ING-TECH 2004. [DOI: 10.1002/cite.330690942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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rolling pebbles(rols) is required inDrosophilamuscle precursors for recruitment of myoblasts for fusion. Development 2001; 128:5061-73. [PMID: 11748142 DOI: 10.1242/dev.128.24.5061] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mutations in the rolling pebbles (rols) gene result in severe defects in myoblast fusion. Muscle precursor cells are correctly determined, but myogenesis does not progress significantly beyond this point because recognition and/or cell adhesion between muscle precursor cells and fusion-competent myoblasts is disturbed. Molecular analysis of the rols genomic region reveals two variant transcripts of rols due to different transcription initiation sites, rols6 and rols7. rols6 mRNA is detectable mainly in the endoderm during differentiation as well as in malpighian tubules and in the epidermis. By contrast, rols7 expression is restricted to the mesoderm and later to progenitor descendants during somatic and pharyngeal muscle development. Transcription starts at the extended germ band stage when progenitor/founder cells are determined and persists until stage 13. The proteins encoded by the rols gene are 1670 (Rols6) and 1900 (Rols7) amino acids in length. Both forms contain an N-terminal RING-finger motif, nine ankyrin repeats and a TPR repeat eventually overlaid by a coiled-coil domain. The longer protein, Rols7, is characterized by 309 unique N-terminal amino acids, while Rols6 is distinguishable by 79 N-terminal amino acids. Expression of rols7 in muscle founder cells indicates a function of Rols7 in these cells. Transplantation assays of rols mutant mesodermal cells into wild-type embryos show that Rols is required in muscle precursor cells and is essential to recruit fusion-competent myoblasts for myotube formation.
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A new lysozyme fold. Crystal structure of the muramidase from Streptomyces coelicolor at 1.65 A resolution. J Biol Chem 2001; 276:31994-9. [PMID: 11427528 DOI: 10.1074/jbc.m102591200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cellosyl is a bacterial muramidase from Streptomyces coelicolor. Similar to other lysozymes, the enzyme cleaves the beta-1,4-glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine units, but it also exhibits a beta-1,4-N,6-O-diacetylmuramidase activity. The latter enables Cellosyl to degrade the cell walls of Staphylococcus aureus, which are not hydrolyzed by chicken-, goose-, or bacteriophage T4-type lysozymes. The enzymatic activity and amino acid sequence of Cellosyl group it with lysozymes of the Chalaropsis type, for which no detailed structural information has been available so far. The crystal structure of Cellosyl from S. coelicolor has been determined to a resolution of 1.65 A and refined to an R-factor of 15.2%. The enzyme is comprised of a single domain and possesses an unusual beta/alpha-barrel fold. The last strand, beta 8, of the (beta/alpha)(5)beta(3)-barrel is found to be antiparallel to strands beta 7 and beta 1. Asp-9, Asp-98, and Glu-100 are located at the active site. The structure of Cellosyl exhibits a new lysozyme fold and represents a new class of polysaccharide-hydrolyzing beta/alpha-barrels.
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Abstract
BACKGROUND Nontraumatic perforations of the extrahepatic biliary ductal system are a rare albeit recognized occurrence in the cystic duct, choledochus and main hepatic duct; the latter appears to be the rarest. METHODS Recent experience with such a case prompted a thorough review of 26 similar cases previously reported. RESULTS It appears that obstruction of the biliary tract by gallstones results in raised intraductal pressure leading to dilatation of the biliary tree, subsequent stasis and infection, causing ascending cholangitis and thrombosis of intramural vessels, leading to necrosis and perforation of the duct wall. Most patients present with an acute abdomen and are operated upon. CONCLUSIONS The goals of operation, which should be tailored to the individual patient, are to stop the bile leak, cure choledocholithiasis and cholangitis and reconstruct the bile duct.
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Tectorin mRNA expression is spatially and temporally restricted during mouse inner ear development. J Comp Neurol 1999; 405:271-80. [PMID: 10023815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The tectorial and otolithic membranes are extracellular matrices that cover the sensory epithelia of the inner ear. They are required for mechanotransduction and may influence hair-cell development. The mRNA expression patterns for two major glycoproteins of these matrices, alpha- and beta-tectorin, were examined during mouse inner ear development to determine when and where these proteins are produced relative to hair cells and whether tectorin production is continuous or transient. Using in situ hybridisation, alpha- and beta-tectorin mRNAs are first detected in the basal end of the cochlea at embryonic day (E) 12.5, and the distinct patterns observed for each tectorin mRNA in the neonate become visible by E14.5. The neonatal expression patterns indicate that some cell types in the cochlea express both alpha- and beta-tectorin mRNAs, while other cells only express one tectorin mRNA. Although expressed early in development, alpha- and beta-tectorin mRNAs cannot be detected in the cochlea by postnatal day (P) 22. In the saccule and utricle, alpha-tectorin mRNA is detected at E12.5, but beta-tectorin mRNA is not observed until E14.5. Expression of alpha-tectorin mRNA ceases after P15, whereas beta-tectorin mRNA expression continues within the striolar region of the utricle until at least P150. The results show alpha- and beta-tectorin mRNAs are expressed during the early stages of inner ear development, prior to or concomitant with hair-cell differentiation, and before the appearance of hair bundles. The expression patterns suggest different cell types contribute to the formation of the various regions of the tectorial membrane. Although tectorin mRNAs are only expressed transiently during cochlear development, beta-tectorin mRNA is continuously expressed within the striolar region of the utricle.
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