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Horn AG, Schulze KM, Weber RE, Barstow TJ, Musch TI, Poole DC, Behnke BJ. Post-occlusive reactive hyperemia and skeletal muscle capillary hemodynamics. Microvasc Res 2022; 140:104283. [PMID: 34822837 PMCID: PMC8830587 DOI: 10.1016/j.mvr.2021.104283] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 10/01/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 10/19/2022]
Abstract
Post-occlusive reactive hyperemia (PORH) is an accepted diagnostic tool for assessing peripheral macrovascular function. While conduit artery hemodynamics have been well defined, the impact of PORH on capillary hemodynamics remains unknown, despite the microvasculature being the dominant site of vascular control. Therefore, the purpose of this investigation was to determine the effects of 5 min of feed artery occlusion on capillary hemodynamics in skeletal muscle. We tested the hypothesis that, upon release of arterial occlusion, there would be: 1) an increased red blood cell flux (fRBC) and red blood cell velocity (VRBC), and 2) a decreased proportion of capillaries supporting RBC flow compared to the pre-occlusion condition. METHODS In female Sprague-Dawley rats (n = 6), the spinotrapezius muscle was exteriorized for evaluation of capillary hemodynamics pre-occlusion, 5 min of feed artery occlusion (Occ), and 5 min of reperfusion (Post-Occ). RESULTS There were no differences in mean arterial pressure (MAP) or capillary diameter (Dc) between pre-occlusion and post-occlusion (P > 0.05). During 30 s of PORH, capillary fRBC was increased (pre: 59 ± 4 vs. 30 s-post: 77 ± 2 cells/s; P < 0.05) and VRBC was not changed (pre: 300 ± 24 vs. 30 s post: 322 ± 25 μm/s; P > 0.05). Capillary hematocrit (Hctcap) was unchanged across the pre- to post-occlusion conditions (P > 0.05). Following occlusion, there was a 20-30% decrease in the number of capillaries supporting RBC flow at 30 s and 300 s-post occlusion (pre: 92 ± 2%; 30 s-post: 66 ± 3%; 300 s-post: 72 ± 6%; both P < 0.05). CONCLUSION Short-term feed artery occlusion (i.e. 5 min) resulted in a more heterogeneous capillary flow profile with the presence of capillary no-reflow, decreasing the percentage of capillaries supporting RBC flow. A complex interaction between myogenic and metabolic mechanisms at the arteriolar level may play a role in the capillary no-reflow with PORH. Measurements at the level of the conduit artery mask significant alterations in blood flow distribution in the microcirculation.
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Affiliation(s)
- Andrew G Horn
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States of America.
| | - Kiana M Schulze
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States of America
| | - Ramona E Weber
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States of America
| | - Thomas J Barstow
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States of America
| | - Timothy I Musch
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States of America; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, United States of America
| | - David C Poole
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States of America; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, United States of America
| | - Bradley J Behnke
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States of America; Johnson Cancer Research Center, Kansas State University, Manhattan, KS, United States of America
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de Paula MP, Moraes AB, de Souza MDGC, Cavalari EMR, Campbell RC, Fernandes GDS, Farias MLF, Mendonça LMC, Madeira M, Bouskela E, Kraemer-Aguiar LG, Vieira Neto L. Cortisol level after dexamethasone suppression test in patients with non-functioning adrenal incidentaloma is positively associated with the duration of reactive hyperemia response on microvascular bed. J Endocrinol Invest 2021; 44:609-619. [PMID: 32686043 DOI: 10.1007/s40618-020-01360-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 07/09/2020] [Indexed: 12/20/2022]
Abstract
PURPOSE Data on endothelial derangements in patients with non-functioning adrenal incidentaloma (NFAI) are scarce. METHODS We investigated if NFAI patients present clinical, biochemical and endothelial alterations compared to individuals without an adrenal lesion and also the associations among these variables. Forty-two NFAI and 40 controls were evaluated. NFAI diagnosis and controls were defined according to the current guidelines and based on a normal adrenal imaging exam, respectively. Body composition was evaluated by dual emission X-ray absorptiometry. Endothelial reactivity was assessed by two methods: tonometry (Endo-PAT®) and laser speckle contrast imaging (LSCI). RESULTS There were no differences between groups regarding age, gender, ethnicity, smoking status, and statin use. The frequency of metabolic syndrome according to the International Diabetes Federation criteria was 69% and 57.9%, respectively in NFAI and controls (p = 0.36), whereas the atherosclerotic cardiovascular disease (ASCVD) risk was 63.4% and 66.7% (p = 0.81). The clinical, laboratory, and anthropometric characteristics, as well as body composition, were similar between the groups. Additionally, any differences between groups were observed on endothelial reactivity tests. Nevertheless, we noted an association between cortisol levels after 1 mg-dexamethosone suppression test (1 mg-DST) and the duration of post-occlusive reactive hyperemia tested on microcirculation (r = 0.30; p = 0.03). NFAI patients require more antihypertensive drugs to achieve blood pressure control (p = 0.04). The number of antihypertensive drugs used to control blood pressure correlated with cortisol levels after 1 mg-DST (r = 0.29; p = 0.03). CONCLUSIONS Since both groups herein investigated had a high frequency of metabolic syndrome and ASCVD risk, it might explain similarities observed on endothelial reactivity. Nevertheless, prolonged reactive hyperemia response on microcirculation was correlated with cortisol levels under suppression.
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Affiliation(s)
- M P de Paula
- Department of Internal Medicine and Endocrine Unit, Federal University of Rio de Janeiro, School of Medicine, Clementino Fraga Filho University Hospital, Professor Rodolpho Paulo Rocco Street, 255, 9th Floor, Rio de Janeiro, RJ, Brazil
| | - A B Moraes
- Department of Internal Medicine and Endocrine Unit, Federal University of Rio de Janeiro, School of Medicine, Clementino Fraga Filho University Hospital, Professor Rodolpho Paulo Rocco Street, 255, 9th Floor, Rio de Janeiro, RJ, Brazil
| | - M das Graças Coelho de Souza
- Laboratory for Clinical and Experimental Research on Vascular Biology, Biomedical Center, State University of Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil
| | - E M R Cavalari
- Department of Internal Medicine and Endocrine Unit, Federal University of Rio de Janeiro, School of Medicine, Clementino Fraga Filho University Hospital, Professor Rodolpho Paulo Rocco Street, 255, 9th Floor, Rio de Janeiro, RJ, Brazil
| | - R C Campbell
- Department of Internal Medicine and Endocrine Unit, Federal University of Rio de Janeiro, School of Medicine, Clementino Fraga Filho University Hospital, Professor Rodolpho Paulo Rocco Street, 255, 9th Floor, Rio de Janeiro, RJ, Brazil
| | - G da Silva Fernandes
- Department of Internal Medicine and Endocrine Unit, Federal University of Rio de Janeiro, School of Medicine, Clementino Fraga Filho University Hospital, Professor Rodolpho Paulo Rocco Street, 255, 9th Floor, Rio de Janeiro, RJ, Brazil
| | - M L F Farias
- Department of Internal Medicine and Endocrine Unit, Federal University of Rio de Janeiro, School of Medicine, Clementino Fraga Filho University Hospital, Professor Rodolpho Paulo Rocco Street, 255, 9th Floor, Rio de Janeiro, RJ, Brazil
| | - L M C Mendonça
- Department of Internal Medicine and Rheumatology Unit, Federal University of Rio de Janeiro, School of Medicine, Clementino Fraga Filho University Hospital, Rio de Janeiro, RJ, Brazil
| | - M Madeira
- Department of Internal Medicine and Endocrine Unit, Federal University of Rio de Janeiro, School of Medicine, Clementino Fraga Filho University Hospital, Professor Rodolpho Paulo Rocco Street, 255, 9th Floor, Rio de Janeiro, RJ, Brazil
| | - E Bouskela
- Laboratory for Clinical and Experimental Research on Vascular Biology, Biomedical Center, State University of Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil
| | - L G Kraemer-Aguiar
- Laboratory for Clinical and Experimental Research on Vascular Biology, Biomedical Center, State University of Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil
- Endocrinology, Department of Internal Medicine, Faculty of Medical Sciences, State University of Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil
| | - L Vieira Neto
- Department of Internal Medicine and Endocrine Unit, Federal University of Rio de Janeiro, School of Medicine, Clementino Fraga Filho University Hospital, Professor Rodolpho Paulo Rocco Street, 255, 9th Floor, Rio de Janeiro, RJ, Brazil.
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Kirby BS, Sparks MA, Lazarowski ER, Lopez Domowicz DA, Zhu H, McMahon TJ. Pannexin 1 channels control the hemodynamic response to hypoxia by regulating O 2-sensitive extracellular ATP in blood. Am J Physiol Heart Circ Physiol 2021; 320:H1055-H1065. [PMID: 33449849 PMCID: PMC7988759 DOI: 10.1152/ajpheart.00651.2020] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 12/23/2022]
Abstract
Pannexin 1 (Panx1) channels export ATP and may contribute to increased concentration of the vasodilator ATP in plasma during hypoxia in vivo. We hypothesized that Panx1 channels and associated ATP export contribute to hypoxic vasodilation, a mechanism that facilitates the matching of oxygen delivery to metabolic demand of tissue. Male and female mice devoid of Panx1 (Panx1-/-) and wild-type controls (WT) were anesthetized, mechanically ventilated, and instrumented with a carotid artery catheter or femoral artery flow transducer for hemodynamic and plasma ATP monitoring during inhalation of 21% (normoxia) or 10% oxygen (hypoxia). ATP export from WT vs. Panx1-/-erythrocytes (RBC) was determined ex vivo via tonometer experimentation across progressive deoxygenation. Mean arterial pressure (MAP) was similar in Panx1-/- (n = 6) and WT (n = 6) mice in normoxia, but the decrease in MAP in hypoxia seen in WT was attenuated in Panx1-/- mice (-16 ± 9% vs. -2 ± 8%; P < 0.05). Hindlimb blood flow (HBF) was significantly lower in Panx1-/- (n = 6) vs. WT (n = 6) basally, and increased in WT but not Panx1-/- mice during hypoxia (8 ± 6% vs. -10 ± 13%; P < 0.05). Estimation of hindlimb vascular conductance using data from the MAP and HBF experiments showed an average response of 28% for WT vs. -9% for Panx1-/- mice. Mean venous plasma ATP during hypoxia was 57% lower in Panx1-/- (n = 6) vs. WT mice (n = 6; P < 0.05). Mean hypoxia-induced ATP export from RBCs from Panx1-/- mice (n = 8) was 82% lower than that from WT (n = 8; P < 0.05). Panx1 channels participate in hemodynamic responses consistent with hypoxic vasodilation by regulating hypoxia-sensitive extracellular ATP levels in blood.NEW & NOTEWORTHY Export of vasodilator ATP from red blood cells requires pannexin 1. Blood plasma ATP elevations in response to hypoxia in mice require pannexin 1. Hemodynamic responses to hypoxia are accompanied by increased plasma ATP in mice in vivo and require pannexin 1.
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Affiliation(s)
- Brett S Kirby
- Division of Hematology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Matthew A Sparks
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
- Departments of Medicine and Research and Development, Durham Veterans Affairs Medical Center, Durham, North Carolina
| | - Eduardo R Lazarowski
- Department of Medicine, Marsico Lung Institute/UNC Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina
| | - Denise A Lopez Domowicz
- Division of Critical Care Medicine, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina
| | - Hongmei Zhu
- Division of Pulmonary, Allergy, Critical Care Medicine, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Timothy J McMahon
- Department of Medicine, Marsico Lung Institute/UNC Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina
- Division of Pulmonary, Allergy, Critical Care Medicine, Department of Medicine, Duke University Medical Center, Durham, North Carolina
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Soares RN, de Oliveira GV, Alvares TS, Murias JM. The effects of the analysis strategy on the correlation between the NIRS reperfusion measures and the FMD response. Microvasc Res 2019; 127:103922. [PMID: 31479661 DOI: 10.1016/j.mvr.2019.103922] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [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: 07/25/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 11/19/2022]
Abstract
This study aimed to investigate the correlation between near-infrared spectroscopy (NIRS)-derived measures of microvascular responses using a range of different analysis and flow-mediated dilation (FMD). Additionally, we aimed to investigate whether assessing NIRS and FMD simultaneously or non-simultaneously would affect this association. Thirty-five healthy young individuals (26 ± 13 years old) participated in the study. Twenty were submitted to a simultaneous NIRS/FMD test (NIRS probe placed below the cuff during FMD test) and fifteen to a non-simultaneous FMD and NIRS intervention (NIRS test performed 20 min after FMD). NIRS-derived oxygen saturation signal (StO2) during reperfusion was analyzed as follow: upslope of a 10 s (slope 10 s) and 30 s (slope 30 s) reperfusion window immediately following cuff deflation, time for the StO2 to reach the pre-occlusion (baseline) values after cuff release (time to baseline) and to reach the peak after cuff release (time to max), difference between the minimum and maximum StO2 value reached after cuff deflation (Magnitude) and; the total area under the reperfusion curve above the baseline value until the end of the 2 min post cuff release (AUC 2 min). There was a significant positive correlation between slope 10 s and FMD in the simultaneous (r = 0.60; p < 0.05) and non-simultaneous (r = 0.62; p < 0.05) assessments. There was no significant correlation between NIRS-derived slope 30 s, time to baseline, time to max, magnitude, and AUC 2 min and the FMD in both methods. The association between NIRS and FMD is analysis strategy dependent, regardless if assessed simultaneously or non-simultaneously.
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Affiliation(s)
| | - Gustavo Vieira de Oliveira
- Nutrition and Exercise Metabolism Research Group, Nutrition Institute, Federal University of Rio de Janeiro, Macaé, Rio de Janeiro, Brazil; Postgraduate Program in Bioactive Products and Biosciences, Federal University of Rio de Janeiro, Macaé, RJ, Brazil
| | - Thiago Silveira Alvares
- Nutrition and Exercise Metabolism Research Group, Nutrition Institute, Federal University of Rio de Janeiro, Macaé, Rio de Janeiro, Brazil; Postgraduate Program in Bioactive Products and Biosciences, Federal University of Rio de Janeiro, Macaé, RJ, Brazil
| | - Juan Manuel Murias
- Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, AB, Canada.
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Zhou S, Giannetto M, DeCourcey J, Kang H, Kang N, Li Y, Zheng S, Zhao H, Simmons WR, Wei HS, Bodine DM, Low PS, Nedergaard M, Wan J. Oxygen tension-mediated erythrocyte membrane interactions regulate cerebral capillary hyperemia. Sci Adv 2019; 5:eaaw4466. [PMID: 31149638 PMCID: PMC6541463 DOI: 10.1126/sciadv.aaw4466] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/17/2019] [Indexed: 05/24/2023]
Abstract
The tight coupling between cerebral blood flow and neural activity is a key feature of normal brain function and forms the basis of functional hyperemia. The mechanisms coupling neural activity to vascular responses, however, remain elusive despite decades of research. Recent studies have shown that cerebral functional hyperemia begins in capillaries, and red blood cells (RBCs) act as autonomous regulators of brain capillary perfusion. RBCs then respond to local changes of oxygen tension (PO2) and regulate their capillary velocity. Using ex vivo microfluidics and in vivo two-photon microscopy, we examined RBC capillary velocity as a function of PO2 and showed that deoxygenated hemoglobin and band 3 interactions on RBC membrane are the molecular switch that responds to local PO2 changes and controls RBC capillary velocity. Capillary hyperemia can be controlled by manipulating RBC properties independent of the neurovascular unit, providing an effective strategy to treat or prevent impaired functional hyperemia.
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Affiliation(s)
- Sitong Zhou
- Microsystems Engineering, Rochester Institute of Technology, Rochester, NY 14623, USA
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Michael Giannetto
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - James DeCourcey
- College of Osteopathic Medicine, University of New England, Biddeford, ME 04005, USA
| | - Hongyi Kang
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Ning Kang
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Yizeng Li
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Suilan Zheng
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Hetince Zhao
- New York University Langone Medical Center, New York, NY 10010, USA
| | | | - Helen S. Wei
- Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - David M. Bodine
- National Human Genome Research Institute, Bethesda, MD 20894, USA
| | - Philip S. Low
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Jiandi Wan
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
- Department of Chemical Engineering, University of California, Davis, Davis, CA 95616, USA
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Abstract
In patients with chronic renal failure treated by long-term dialysis, inflammatory reactions occasionally develop in the bulbar conjunctiva; the episcleral tissue is only rarely involved. Diffuse congestion of both the conjunctiva and episclera was present in 5.3% of our patients and was associated with a sudden, marked rise in serum calcium. Histopathological examination suggests that this form of hyperemia, clinically preceded by a marked shedding of calcific precipitates, is the result of a neurogenic-driven inflammatory reaction in which mast cell degranulation is mediated by the axon reflex. Focal hyperemia associated with elastosis ("pingueculitis") was present in 6.7% of the patients. This type of hyperemia was observed after an extended period of increasing levels of BUN and seemed independent of both serum calcium and phosphorus. Diffuse hyperemia of the conjunctiva, being clinically distinctly different from the combined diffuse conjunctival and episcleral hyperemia, was also observed in 6.7%. Diffuse conjunctival hyperemia seemed to be associated with low BUN. Here, again, there was no association with serum calcium and phosphorus levels.
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Ostrem JD, Evanoff NG, Ryder JR, Steinberger J, Sinaiko AR, Bisch KL, Brinck NM, Dengel DR. High-flow-mediated constriction in adults is not influenced by biomarkers of cardiovascular and metabolic risk. J Clin Ultrasound 2017; 45:35-42. [PMID: 27492803 PMCID: PMC5159190 DOI: 10.1002/jcu.22387] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 07/05/2016] [Indexed: 05/09/2023]
Abstract
PURPOSE During reactive hyperemia, the brachial artery in some individuals constricts prior to dilation. Our aim was to describe the frequency of high-flow-mediated constriction (H-FMC) in adults, and its relationship to body composition and biomarkers of cardiovascular and metabolic risk. METHODS Two hundred forty-six adults (124 male, 122 female; 36 ± 7 years old) were assessed for H-FMC via sonographic imaging of the brachial artery. Blood pressure, glucose, insulin, lipids, and body composition assessed via dual energy X-ray absorptiometry were collected. H-FMC was characterized as a 10-second average of maximal postocclusion constriction. Independent t test was used to compare H-FMC versus non-H-FMC individuals. RESULTS H-FMC was observed in approximately 69% of adult participants (54 obese, 57 overweight, and 59 normal weight). Total body mass (82.3 ± 17.5 versus 76.3 ± 16.3 kg, p = 0.012), fat mass (27.7 ± 11.5 versus 23.8 ± 10.5 kg, p = 0.012), body mass index (27.7 ± 4.9 versus 26.1 ± 5.0 kg/m2 , p = 0.018), and low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio (2.41 ± 1.03 versus 2.09 ± 0.72, p = 0.007) were higher in H-FMC than in non-H-FMC individuals. Flow-mediated dilatation (FMD) (6.12 ± 3.48 versus 8.09 ± 3.02%, p < 0.001) was lower in H-FMC subjects. However, there was no difference in brachial artery dilation between groups (7.57 ± 3.69 versus 8.09 ± 3.02%, p = 0.250) when H-FMC was added to FMD. CONCLUSIONS Increased body mass, fat mass, and body mass index were associated with a greater H-FMC. When H-FMC was present, the FMD response to reactive hyperemia was significantly lower. Because H-FMC has been observed to negatively affect FMD response to reactive hyperemia, we suggest that H-FMC should be noted when analyzing and interpreting FMD data. H-FMC may be an ancillary measure of endothelial health. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:35-42, 2017.
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Affiliation(s)
- Joseph D. Ostrem
- Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, 55455
| | - Nicholas G. Evanoff
- Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, 55455
| | - Justin R. Ryder
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Julia Steinberger
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Alan R. Sinaiko
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Katie L. Bisch
- Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, 55455
| | - Niklas M. Brinck
- Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, 55455
| | - Donald R. Dengel
- Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, 55455
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
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Akçay Ş, Doğrul I, Sezer S, Haberal M. Role of Procalcitonin in Differential Diagnosis of Pneumonia and Pulmonary Congestion Associated With End-Stage Renal Failure. EXP CLIN TRANSPLANT 2016; 14:71-73. [PMID: 27805517] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
OBJECTIVES We aimed to determine the role of procalcitonin in distinguishing between infectious and noninfectious causes, specifically the cause of the infiltrative appearances detected on lung radiographs of patients with end-stage renal failure receiving hemodialysis. MATERIALS AND METHODS Sixty-six patients between 19 and 87 years of age were enrolled. Patients were divided into 3 groups, with each group consisting of 22 patients: group 1 comprised pneumonia patients without end-stage renal failure, group 2 comprised pulmonary congestion patients with end-stage renal failure, and group 3 were healthy participants. All demographic and clinical characteristics of patients and healthy participants were noted, anteroposterior lung radiographs were taken, and blood samples were obtained for complete blood count, C-reactive protein, and procalcitonin measurements. Patients in group 2 received control posteroanterior lung radiography. RESULTS Group 1 demonstrated a significantly lower mean procalcitonin value than group 2 (P = .001) but significantly higher mean C-reactive protein and leukocyte levels (P < .05). In terms of mean C-reactive protein and leukocyte levels, there was no difference between groups 2 and 3 (P > .05). The classification performed by recognizing 0.5 ng/mL as the cutoff point for procalcitonin resulted in no significant differences between groups 1 and 2 (P = .103). However, a significant difference (P = .014) was found between these groups when basing the classification as 1.5 ng/mL cutoff point in group 2 and 0.5 ng/mL cutoff point in group 1. Procalcitonin level was below 1.5 ng/mL in all group 2 patients. CONCLUSIONS Our findings support that procalcitonin has no superiority over C-reactive protein in diagnosis of community-acquired pneumonia. Moreover, at procalcitonin values below 1.5 ng/mL in patients with end-stage renal failure who have pulmonary congestion but without clinical signs of infection, infiltrative appearances on lung images may be attributed to hypervolemia, which would in turn prevent unnecessary antibiotic therapies. We believe that measurement of C-reactive protein is still preferable to procalcitonin in revealing the inflammatory response due to its cost-effectiveness and ease in performance and the high diagnostic performance in transplant candidates.
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Affiliation(s)
- Şule Akçay
- From the Department of Pulmonary Diseases, Baskent University Faculty of Medicine, Ankara, Turkey
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Chan MTV, Gin T. Predicting postoperative cardiac complications using automated endothelial function test. Hong Kong Med J 2015; 21 Suppl 6:17-18. [PMID: 26645877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023] Open
Affiliation(s)
- M T V Chan
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong
| | - T Gin
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong
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Butler GJ, Kenyon DJ, Gorenstein S, Davenport T, Golembe E, Lee B, Vieweg J. Oxy-Mat™ Mattress System Development Utilizing Simultaneous Measurement of Interface Pressure and Deep Tissue Oxygen Saturation. Surg Technol Int 2015; 26:71-82. [PMID: 26054994] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The development and management of pressure ulcers (PUs) among hospital and nursing home patients is one of the greatest preventable challenges to healthcare worldwide. For over 50 years, pressure mapping and subjective comfort has been the primary indicators for mattress selection. Our research demonstrates that mattress/patient interface pressure and relative blood/oxygen perfusion do not inversely correlate and pressure is not a meaningful, real-time indicator of tissue ischemia and risk of pressure ulcer development. Developed in our research is a real-time sensor system to simultaneously measure and record these parameters over the anatomical sites at risk for PUs. Measurements focused on the heel, sacrum, trochanter, ischium, scapula and occipital. A modified pressure mapping system is used for interface pressure measurements and integrated with multiple near-infrared sensors to measure specific deep tissue hemoglobin saturated oxygen or rSO2. Testing and mattress design development was done during the period of 2008 to present. Over 200 human tests of commercially available mattresses were conducted in supine, 30 degree, and 70 degree positions, ranging in times of up to four hours. During this time period, we utilized 20 test subjects-eight female and 12 male-with ages ranging from 18 to 65 years. The result of this proprietary off-loading device evaluation and design system shows that the new Oxy-Mat™ (Off-Loading Technologies, Tarrytown, NY) Non-Powered Mattress System consistently provides optimized tissue perfusion as measured by natural deep tissue oxygen saturation levels. In extensive laboratory and clinical evaluations, the Oxy-Mat™ was shown to be functionally superior to CMS Group 2 powered mattresses. Another outcome of our research was that a powered mattress system may not be appropriate for most sensate and semi-ambulatory patients. Further research is underway.
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Affiliation(s)
| | | | - Scott Gorenstein
- Division of Regenerative Medicine, Winthrop University Hospital, Mineola, NY, / Life Support Technologies Group, Tarrytown, NY
| | | | - Edward Golembe
- Skin Integrity Service, Westchester Medical Center, Valhalla, NY / Life Support Technologies Group, Tarrytown, NY
| | - Bok Lee
- Department of Surgery, New York Medical College, Valhalla, NY / Life Support Technologies Group Tarrytown, NY
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Tuna MM, Doğan BA, Karakılıç E, Arduç A, Işık S, Yılmaz FM, Topçuoğlu C, Berker D, Güler S. Evaluation of adipocytokine levels and vascular functions in young aged to middle aged men with idiopathic hypogonadotrophic hypogonadism. Neuro Endocrinol Lett 2014; 35:640-644. [PMID: 25617889] [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] [Received: 08/22/2014] [Accepted: 10/12/2014] [Indexed: 06/04/2023]
Abstract
OBJECTIVE Hypogonadism has major effects on the urogenital system, in addition to other systems, the cardiovascular system in particular. There have been few studies conducted on markers of atherosclerosis, such as flow mediated dilatation (% FMD), carotid intima-media thickness (CIMT) and adipocytokine levels in idiopatic hypogonadotropic hypogonadal (IHH) males mostly in adult patients. The aim of this study was to evaluate the relationship between androgens and adipocytokines and parameters of vascular functions in hypogonadal men. MATERIALS AND METHODS The study population consisted of 11 treatment naive IHH patients (group 1) and 15 age-matched healthy control males (group 2). A fasting blood sample was obtained for leptin, adiponectin and resistin. The endothelial functions were evaluated by studying % FMD and CIMT by high resolution B-mode ultrasound. RESULTS No significant differences in age, body mass index, systolic and diastolic blood pressure were recorded between the two groups. The leptin level was significantly higher in group 1, whereas adiponectin and resistin levels were same between two groups. There was a negative correlation between total testosterone and carotid intima-media thickness (r=-0.656, p=0.008), and a negative correlation between total testosterone and leptin level (r=-0.794, p<0.001). No correlation was found between leptin and CIMT (p=0.184). CONCLUSION Testosterone deficiency in hypogonadal men is associated with vascular parameters of atherosclerosis. The findings may establish indications for testosterone replacement therapy in hypogonadal men.
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Affiliation(s)
- Mazhar Müslüm Tuna
- Department of Endocrinology and Metabolism, Medical Faculty, Dicle University, Turkey
| | - Berçem Ayçiçek Doğan
- Department of Endocrinology and Metabolism, Ankara Numune Training and Research Hospital, Turkey
| | - Ersen Karakılıç
- Department of Endocrinology and Metabolism, Ankara Numune Training and Research Hospital, Turkey
| | - Ayşe Arduç
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Diabetes, Endocrine and Obesity Branch, Washington, USA
| | - Serhat Işık
- Department of Endocrinology and Metabolism, Ankara Numune Training and Research Hospital, Turkey
| | - Fatma Meriç Yılmaz
- Department of Medical Biochemistry, Ankara Numune Training and Research Hospital, Turkey
| | - Canan Topçuoğlu
- Department of Medical Biochemistry, Ankara Numune Training and Research Hospital, Turkey
| | - Dilek Berker
- Department of Endocrinology and Metabolism, Ankara Numune Training and Research Hospital, Turkey
| | - Serdar Güler
- Department of Endocrinology and Metabolism, Medical Faculty, Hitit University, Turkey
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He HW, Liu DW, Wang XT, Long Y, Chai WZ, Zhou X, Li X, Cai J. [Value of peripheral perfusion index in the assessment of reactive hyperemia in septic patients]. Zhonghua Yi Xue Za Zhi 2013; 93:3265-3268. [PMID: 24401619] [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: 06/03/2023]
Abstract
OBJECTIVE To explore the changes of peripheral perfusion index (PI) during forearm vascular occlusion test (VOT) and examine its evaluative value of reactive hyperemia in septic patients. METHODS Twenty-one patients with septic shock, 21 postoperative ones without infection and 18 health volunteers were prospectively recruited to undergo vascular occlusion test. An arrest of forearm blood flow was applied for 3 min with a sphygmomanometer inflated to a pressure approximately 30 mm Hg greater than systolic pressure around forearm. PI was measured and recorded continuously by conventional pulse oximetry during VOT. RESULTS (1)In all subjects, the PI values decreased to zero during ischemic period. There were no changes in heart rate or blood pressure between baseline and reperfusion. The maximum PI (PI-max) after a release of pneumatic cuff was significantly higher than baseline PI; (2)The change rates of PI-max and PI were significantly lower and the time to PI-max was longer in septic group after reperfusion; (3) A negative relationship existed between PI change rate and sequential organ failure assessment (SOFA) score in septic group. CONCLUSIONS PI may be used to assess vascular reactive hyperemia in critically ill patients. And the capacity of peripheral vascular reactive hyperemia decreases in septic patients.
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Affiliation(s)
- Huai-wu He
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Da-wei Liu
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730, China.
| | - Xiao-ting Wang
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Yun Long
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Wen-zhao Chai
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Xiang Zhou
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Xin Li
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Jing Cai
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730, China
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Lobysheva II, Biller P, Gallez B, Beauloye C, Balligand JL. Nitrosylated hemoglobin levels in human venous erythrocytes correlate with vascular endothelial function measured by digital reactive hyperemia. PLoS One 2013; 8:e76457. [PMID: 24130774 PMCID: PMC3794924 DOI: 10.1371/journal.pone.0076457] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [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: 06/28/2013] [Accepted: 08/21/2013] [Indexed: 11/21/2022] Open
Abstract
Impaired nitric oxide (NO)–dependent endothelial function is associated with the development of cardiovascular diseases. We hypothesized that erythrocyte levels of nitrosylated hemoglobin (HbNO-heme) may reflect vascular endothelial function in vivo. We developed a modified subtraction method using Electron Paramagnetic Resonance (EPR) spectroscopy to identify the 5-coordinate α-HbNO (HbNO) concentration in human erythrocytes and examined its correlation with endothelial function assessed by peripheral arterial tonometry (PAT). Changes in digital pulse amplitude were measured by PAT during reactive hyperemia following brachial arterial occlusion in a group of healthy volunteers (50 subjects). Erythrocyte HbNO levels were measured at baseline and at the peak of hyperemia. We digitally subtracted an individual model EPR signal of erythrocyte free radicals from the whole EPR spectrum to unmask and quantitate the HbNO EPR signals. Results Mean erythrocyte HbNO concentration at baseline was 219+/−12 nmol/L (n = 50). HbNO levels and reactive hyperemia (RH) indexes were higher in female (free of contraceptive pills) than male subjects. We observed a dynamic increase of HbNO levels in erythrocytes isolated at 1–2 min of post-occlusion hyperemia (120+/−8% of basal levels); post-occlusion HbNO levels were correlated with basal levels. Both basal and post-occlusion HbNO levels were significantly correlated with reactive hyperemia (RH) indexes (r = 0.58; P<0.0001 for basal HbNO). Conclusion The study demonstrates quantitative measurements of 5-coordinate α-HbNO in human venous erythrocytes, its dynamic physiologic regulation and correlation with endothelial function measured by tonometry during hyperemia. This opens the way to further understanding of in vivo determinants of NO bioavailability in human circulation.
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Affiliation(s)
- Irina I. Lobysheva
- Institut de Recherche Experimentale et Clinique (IREC), Pole of Pharmacology and Therapeutics (FATH), Université Catholique de Louvain (UCL), Brussels, Belgium
- * E-mail: (IL); (J-LB)
| | - Pauline Biller
- Institut de Recherche Experimentale et Clinique (IREC), Pole of Pharmacology and Therapeutics (FATH), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Bernard Gallez
- Louvain Drug Research Institute, Biomedical Magnetic Resonance Unit, UCL, Brussels, Belgium
| | - Christophe Beauloye
- Pole of Cardiovascular Research (CARD), and Departments of Internal Medicine and Cardiovascular Diseases, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Jean-Luc Balligand
- Institut de Recherche Experimentale et Clinique (IREC), Pole of Pharmacology and Therapeutics (FATH), Université Catholique de Louvain (UCL), Brussels, Belgium
- * E-mail: (IL); (J-LB)
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14
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Englund EK, Langham MC, Li C, Rodgers ZB, Floyd TF, Mohler ER, Wehrli FW. Combined measurement of perfusion, venous oxygen saturation, and skeletal muscle T2* during reactive hyperemia in the leg. J Cardiovasc Magn Reson 2013; 15:70. [PMID: 23958293 PMCID: PMC3765712 DOI: 10.1186/1532-429x-15-70] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 07/30/2013] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The function of the peripheral microvascular may be interrogated by measuring perfusion, tissue oxygen concentration, or venous oxygen saturation (SvO2) recovery dynamics following induced ischemia. The purpose of this work is to develop and evaluate a magnetic resonance (MR) technique for simultaneous measurement of perfusion, SvO2, and skeletal muscle T2*. METHODS Perfusion, Intravascular Venous Oxygen saturation, and T2* (PIVOT) is comprised of interleaved pulsed arterial spin labeling (PASL) and multi-echo gradient-recalled echo (GRE) sequences. During the PASL post-labeling delay, images are acquired with a multi-echo GRE to quantify SvO2 and T2* at a downstream slice location. Thus time-courses of perfusion, SvO2, and T2* are quantified simultaneously within a single scan. The new sequence was compared to separately measured PASL or multi-echo GRE data during reactive hyperemia in five young healthy subjects. To explore the impairment present in peripheral artery disease patients, five patients were evaluated with PIVOT. RESULTS Comparison of PIVOT-derived data to the standard techniques shows that there was no significant bias in any of the time-course-derived metrics. Preliminary data show that PAD patients exhibited alterations in perfusion, SvO2, and T2* time-courses compared to young healthy subjects. CONCLUSION Simultaneous quantification of perfusion, SvO2, and T2* is possible with PIVOT. Kinetics of perfusion, SvO2, and T2* during reactive hyperemia may help to provide insight into the function of the peripheral microvasculature in patients with PAD.
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Affiliation(s)
- Erin K Englund
- Department of Radiology, Laboratory of Structural NMR Imaging, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Michael C Langham
- Department of Radiology, Laboratory of Structural NMR Imaging, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Cheng Li
- Department of Radiology, Laboratory of Structural NMR Imaging, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Zachary B Rodgers
- Department of Radiology, Laboratory of Structural NMR Imaging, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Thomas F Floyd
- Department of Anesthesiology, Stony Brook University Medical Center, Stony Brook, NY 11794, USA
| | - Emile R Mohler
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Felix W Wehrli
- Department of Radiology, Laboratory of Structural NMR Imaging, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104, USA
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15
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Khan F, Choong WL, Du Q, Jovanović A. Real-time RT-PCR threshold cycles value for Kir6.1 from the blood correlates with parameters of vascular function: a potential for the vascular function biomarker? Biomarkers 2013; 18:221-9. [PMID: 23480296 DOI: 10.3109/1354750x.2013.770553] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Abstract We examined the presence of KATP channel subunits, Kir6.1 and SUR2B, mRNAs in the blood and vascular function in healthy volunteers (41 males, 34 females). Real-time reverse transcriptase (RT)-PCR threshold cycles (Ct) was used as an indicator of mRNA levels. Baseline skin perfusion and the post-occlusion reactive hyperemia response exhibited a significant positive correlation with Ct for Kir6.1. There was no correlation between Kir6.1 Ct and brachial artery flow-mediated dilatation. Gender had no influence on relationships between blood Kir6.1 Ct and vascular function. We conclude that blood Kir6.1 mRNA levels could be potentially used as a biomarker of the vascular function.
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Affiliation(s)
- Faisel Khan
- Medical Research Institute, Division of Cardiovascular and Diabetic Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee DD1 9SY, UK
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16
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Theunissen S, Guerrero F, Sponsiello N, Cialoni D, Pieri M, Germonpré P, Obeid G, Tillmans F, Papadopoulou V, Hemelryck W, Marroni A, De Bels D, Balestra C. Nitric oxide-related endothelial changes in breath-hold and scuba divers. Undersea Hyperb Med 2013; 40:135-144. [PMID: 23682545] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
OBJECTIVE Scuba and breath-hold divers are compared to investigate whether endothelial response changes are similar despite different exposure(s) to hyperoxia. DESIGN 14 divers (nine scuba and five breath-holding) performed either one scuba dive (25m/25 minutes) or successive breath-hold dives at a depth of 20 meters, adding up to 25 minutes of immersion time in a diving pool. Flow-mediated dilation (FMD) was measured using echography. Peripheral post-occlusion reactive hyperemia (PORH) was assessed by digital plethysmography and plasmatic nitric oxide (NO) concentration using a nitrate/nitrite colorimetric assay kit. RESULTS The FMD decreased in both groups. PORH was reduced in scuba divers but increased in breath-hold divers. No difference in circulating NO was observed for the scuba group. Opposingly, an increase in circulating NO was observed for the breath-hold group. CONCLUSION Some cardiovascular effects can be explained by interaction between NO and superoxide anion during both types of diving ending to less NO availability and reducing FMD. The increased circulating NO in the breath-hold group can be caused by physical exercise. The opposite effects found between FMD and PORH in the breath-hold group can be assimilated to a greater responsiveness to circulating NO in small arteries than in large arteries.
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Affiliation(s)
- S Theunissen
- Haute Ecole Paul Henri Spaak, Environmental, Occupational & Aging Physiology Lab., Brussels, Belgium.
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17
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Langham MC, Wehrli FW. Simultaneous mapping of temporally-resolved blood flow velocity and oxygenation in femoral artery and vein during reactive hyperemia. J Cardiovasc Magn Reson 2011; 13:66. [PMID: 22035402 PMCID: PMC3223132 DOI: 10.1186/1532-429x-13-66] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 10/28/2011] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Post-occlusive hyperemia is often used as a paradigm to evaluate vascular reactivity, for example by measuring post-ischemic flow-mediated dilation, arterial blood flow or temporally resolved venous blood oxygenation (HbO2). Here we demonstrate the feasibility of a simultaneous measurement of blood flow and HbO2 in the femoral circulation as part of a single procedure. METHODS A multi-echo GRE pulse sequence was designed and implemented to collect velocity-encoded projections in addition to full-image echoes for field mapping as a means to quantify intravascular magnetic susceptibility. The method's feasibility was evaluated at 3T in a small pilot study involving two groups of healthy subjects (mean ages 26 ± 1.6 and 59 ± 7.3 years, N = 7 and 5, respectively) in terms of six parameters characterizing the time-course of reactive hyperemia and their sensitivity to differentiate age effects. The reproducibility was assessed on two of the seven young healthy subjects with three repeated measurements. RESULTS The physiological parameters agree with those obtained with current methods that quantify either velocity or HbO2 alone. Of the six measures of vascular reactivity, one from each group was significantly different in the two subject groups (p < 0.05) even though the study was not powered to detect differences. The mean coefficient of variation (CV) from two subjects undergoing repeat scans were approximately 8% for the oximetric and the arterial velocimetric parameters in the femoral vein and artery, respectively, considerably below intersubject CVs (20 and 35%, for the young and older subject groups, respectively). CONCLUSION The proposed method is able quantify multiple parameters that may lead to more detailed assessment of peripheral vascular reactivity in a single cuff paradigm rather than in separate procedures as required previously, thereby improving measurement efficiency and patient comfort.
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Affiliation(s)
- Michael C Langham
- Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA, USA
| | - Felix W Wehrli
- Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA, USA
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Pope CA, Hansen JC, Kuprov R, Sanders MD, Anderson MN, Eatough DJ. Vascular function and short-term exposure to fine particulate air pollution. J Air Waste Manag Assoc 2011; 61:858-63. [PMID: 21874957 DOI: 10.3155/1047-3289.61.8.858] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Exposure to fine particulate air pollution has been implicated as a risk factor for cardiopulmonary disease and mortality. Proposed biological pathways imply that particle-induced pulmonary and systemic inflammation play a role in activating the vascular endothelium and altering vascular function. Potential effects of fine particulate pollution on vascular function are explored using controlled chamber exposure and uncontrolled ambient exposure. Research subjects included four panels with a total of 26 healthy nonsmoking young adults. On two study visits, at least 7 days apart, subjects spent 3 hr in a controlled-exposure chamber exposed to 150-200 microg/m3 of fine particles generated from coal or wood combustion and 3 hr in a clean room, with exposure and nonexposure periods alternated between visits. Baseline, postexposure, and post-clean room reactive hyperemia-peripheral arterial tonometry (RH-PAT) was conducted. A microvascular responsiveness index, defined as the log of the RH-PAT ratio, was calculated. There was no contemporaneous vascular response to the few hours of controlled exposure. Declines in vascular response were associated with elevated ambient exposures for the previous 2 days, especially for female subjects. Cumulative exposure to real-life fine particulate pollution may affect vascular function. More research is needed to determine the roles of age and gender, the effect of pollution sources, the importance of cumulative exposure over a few days versus a few hours, and the lag time between exposure and response.
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Affiliation(s)
- C Arden Pope
- Department of Economics, Brigham Young University, Provo, UT 84602-2363, USA.
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Abstract
The neuropeptides substance P (SP) and calcitonin gene-related peptide are believed to be involved in the axon reflex-mediated component of cutaneous thermal hyperaemia, but no studies have specifically addressed this issue. The purpose of this study was to determine whether neurokinin-1 receptors, which preferentially bind SP, contribute to the axon reflex component of cutaneous thermal hyperaemia. Nine subjects were equipped with four microdialysis fibres, and each fibre received one of the following four treatments: (1) lactated Ringer's solution (control); (2) 10 mml-NAME to inhibit nitric oxide synthase; (3) 10 μm SP; or (4) 10 μm SP + 10 mml-NAME. Skin blood flow was monitored via laser-Doppler flowmetry, and local skin temperature was controlled using local heating devices. Sites 3 and 4 were perfused with 10 μm SP for 15 min at a rate of 4 μl min(-1), and the ensuing vasodilatation was allowed to return to baseline. Following SP-induced vasodilatation, all skin sites were locally heated from a baseline temperature of 33°C to 42°C at a rate of 0.5°C every 5 s. Cutaneous vascular conductance (CVC) was calculated as skin blood flow/mean arterial pressure and normalized to the maximal value (%CVC(max)) via 28 mm nitroprusside and local heating to 43°C. The initial peak did not differ between control (79 ± 3%CVC(max)) and SP-only sites (79 ± 2%CVC(max)). The initial peaks at the l-NAME (43 ± 3%CVC(max)) and SP + l-NAME sites (53 ± 3%CVC(max)) were significantly reduced compared with both the control and the SP-only sites (P < 0.001 for both), and l-NAME sites were attenuated compared with SP + l-NAME sites (P < 0.01). There was no observable nadir response at sites pretreated with SP. Compared with control sites (57 ± 4%CVC(max)), the nadirs at the l-NAME (14 ± 2%CVC(max)) and the SP + l-NAME sites (31 ± 5%CVC(max)) were significantly reduced (P < 0.01 for all conditions). l-NAME significantly reduced the nadir compared with SP + l-NAME (P < 0.01). Plateau CVC values did not differ between control (86 ± 3%CVC(max)) and SP sites (91 ± 1%CVC(max)). At l-NAME (36 ± 4%CVC(max)) and SP +l-NAME sites (56 ± 6%CVC(max)), plateau CVC was significantly reduced compared with control and SP-only sites (P < 0.01 for all conditions). The plateau at l-NAME sites was significantly reduced compared with SP + l-NAME sites (P < 0.01). These data suggest that neurokinin-1 receptors contribute to both the axon reflex component and the secondary plateau phase of cutaneous thermal hyperaemia.
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Affiliation(s)
- Brett J Wong
- Department of Kinesiology, Kansas State University, Manhattan, KS 66506, USA.
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Abstract
Endogenous Cushing's syndrome (CS) is associated with a high incidence of cardiovascular morbidity and mortality resulting from the co-existence of multiple cardiovascular risk factors which probably induce a state of endothelial dysfunction. Recently, studies conducted in vitro as well as in normal human subjects suggest a direct role of cortisol in the causation of vascular dysfunction in this disorder. We non-invasively assessed the vascular reactivity and its potential association with elevated cortisol levels in patients of CS. A single time point observational study was conducted in 18 patients of CS and 15 age and gender matched healthy subjects. Vascular reactivity was assessed non-invasively by measuring the peripheral pulse wave form changes during reactive hyperemia (RH) using digital photoplethysmography (PPG). Parameters measured were pulse wave form amplitude (PWA), slope and pulse transit time (PTT). Maximal percentage changes in PWA during RH with reference to baseline were significantly lower in the patients as compared to controls [23.19% (13.19-53.54) vs 61.71% (38.21-95.36); p=0.0079]. Normalized PTT responses during the 1(st) minute of RH were blunted in the patients as compared to controls (1.036 ± 0.026 vs 1.056 ± 0.029; p=0.0425). Percentage changes in PTT during the 2(nd) minute of RH were negatively correlated to the morning cortisol levels in patients (r = -0.6328; p=0.0064). The present study showed that endothelium mediated vascular reactivity along with myogenic regulation of vascular tone is impaired in CS. Hypercortisolism possibly plays an important role in the causation of impaired vascular reactivity and endothelial dysfunction in CS.
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Affiliation(s)
- Dinu S Chandran
- Department of Physiology, All India Institute of Medical Sciences, Ansari Nagal, New Delhi, India
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21
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Shmorgun TS, Bovtiushko PV, Shakhnovich PG, Nikitin AE, Filippov AE, Zubenko AI. [Endothelial dysfunction on initial stages of arterial hypertension among men of young age and it's connection with vascular risk factors]. Voen Med Zh 2010; 331:20-25. [PMID: 20564946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Frequency of display endothelial dysfunction, arising on the initial stages of development arterial hypertension is investigated, depending on vascular risk factors. The main group was made by 86 men with arterial hypertension I-II stage, group of the control--practically healthy 50 men. Vasomotor endothelial function defined on a degree of vasodilatation a humeral artery in reply to reactive hyperemia. Damage signs of endothelial monolayer estimated by quantity of free circulating endothelial blue blood cells. It is established, that the simultaneous combination of functional or structural vascular infringements among persons with normal blood pressure was registered in 3 times less often in comparison to patients with an arterial hypertension (p<0,01). At the main group at a simultaneous combination inadequate vasodilatation and endotheliaemia occurrence risk factors in 1,5 times is higher, than at their isolated display (p>0,05).
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Vöhringer M, Flewitt JA, Green JD, Dharmakumar R, Wang J, Tyberg JV, Friedrich MG. Oxygenation-sensitive CMR for assessing vasodilator-induced changes of myocardial oxygenation. J Cardiovasc Magn Reson 2010; 12:20. [PMID: 20356402 PMCID: PMC2861023 DOI: 10.1186/1532-429x-12-20] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [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: 10/01/2009] [Accepted: 03/31/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND As myocardial oxygenation may serve as a marker for ischemia and microvascular dysfunction, it could be clinically useful to have a non-invasive measure of changes in myocardial oxygenation. However, the impact of induced blood flow changes on oxygenation is not well understood. We used oxygenation-sensitive CMR to assess the relations between myocardial oxygenation and coronary sinus blood oxygen saturation (SvO2) and coronary blood flow in a dog model in which hyperemia was induced by intracoronary administration of vasodilators. RESULTS During administration of acetylcholine and adenosine, CMR signal intensity correlated linearly with simultaneously measured SvO2 (r2 = 0.74, P < 0.001). Both SvO2 and CMR signal intensity were exponentially related to coronary blood flow, with SvO2 approaching 87%. CONCLUSIONS Myocardial oxygenation as assessed with oxygenation-sensitive CMR imaging is linearly related to SvO2 and is exponentially related to vasodilator-induced increases of blood flow. Oxygenation-sensitive CMR may be useful to assess ischemia and microvascular function in patients. Its clinical utility should be evaluated.
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Affiliation(s)
- Matthias Vöhringer
- Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, AB, Canada
- Robert-Bosch-Krankenhaus, Stuttgart, Germany
| | - Jacqueline A Flewitt
- Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, AB, Canada
| | - Jordin D Green
- Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, AB, Canada
- Siemens Healthcare, Erlangen, Germany
| | | | - Jiun Wang
- Fu-Jen University Medical School, Hsinchuang, Taiwan
| | - John V Tyberg
- Department of Cardiac Sciences and Physiology/Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Matthias G Friedrich
- Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, AB, Canada
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Namdar M, Schepis T, Koepfli P, Gaemperli O, Siegrist PT, Grathwohl R, Valenta I, Delaloye R, Klainguti M, Wyss CA, Lüscher TF, Kaufmann PA. Caffeine impairs myocardial blood flow response to physical exercise in patients with coronary artery disease as well as in age-matched controls. PLoS One 2009; 4:e5665. [PMID: 19479069 PMCID: PMC2682574 DOI: 10.1371/journal.pone.0005665] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [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: 12/28/2008] [Accepted: 04/25/2009] [Indexed: 01/16/2023] Open
Abstract
Background Caffeine is one of the most widely consumed pharmacologically active substances. Its acute effect on myocardial blood flow is widely unknown. Our aim was to assess the acute effect of caffeine in a dose corresponding to two cups of coffee on myocardial blood flow (MBF) in coronary artery disease (CAD). Methodology/Principal Findings MBF was measured with 15O-labelled H2O and Positron Emission Tomography (PET) at rest and after supine bicycle exercise in controls (n = 15, mean age 58±13 years) and in CAD patients (n = 15, mean age 61±9 years). In the latter, regional MBF was assessed in segments subtended by stenotic and remote coronary arteries. All measurements were repeated fifty minutes after oral caffeine ingestion (200 mg). Myocardial perfusion reserve (MPR) was calculated as ratio of MBF during bicycle stress divided by MBF at rest. Resting MBF was not affected by caffeine in both groups. Exercise-induced MBF response decreased significantly after caffeine in controls (2.26±0.56 vs. 2.02±0.56, P<0.005), remote (2.40±0.70 vs. 1.78±0.46, P<0.001) and in stenotic segments (1.90±0.41 vs. 1.38±0.30, P<0.001). Caffeine decreased MPR significantly by 14% in controls (P<0.05 vs. baseline). In CAD patients MPR decreased by 18% (P<0.05 vs. baseline) in remote and by 25% in stenotic segments (P<0.01 vs. baseline). Conclusions We conclude that caffeine impairs exercise-induced hyperaemic MBF response in patients with CAD to a greater degree than age-matched controls.
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Affiliation(s)
- Mehdi Namdar
- Cardiac Imaging, University Hospital, Zurich, Switzerland
| | | | - Pascal Koepfli
- Cardiac Imaging, University Hospital, Zurich, Switzerland
| | | | | | | | - Ines Valenta
- Cardiac Imaging, University Hospital, Zurich, Switzerland
| | | | | | | | | | - Philipp A. Kaufmann
- Cardiac Imaging, University Hospital, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
- * E-mail:
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24
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O'Doherty J, McNamara P, Clancy NT, Enfield JG, Leahy MJ. Comparison of instruments for investigation of microcirculatory blood flow and red blood cell concentration. J Biomed Opt 2009; 14:034025. [PMID: 19566318 DOI: 10.1117/1.3149863] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The use of laser Doppler perfusion imaging (LDPI) and laser speckle perfusion imaging (LSPI) is well known in the noninvasive investigation of microcirculatory blood flow. This work compares the two techniques with the recently developed tissue viability (TiVi) imaging system, which is proposed as a useful tool to quantify red blood cell concentration in microcirculation. Three systems are evaluated with common skin tests such as the use of vasodilating and vasoconstricting drugs (methlynicotinate and clobetasol, respectively) and a reactive hyperaemia maneuver (using a sphygmomanometer). The devices investigated are the laser Doppler line scanner (LDLS), the laser speckle perfusion imager (FLPI)-both from Moor Instruments (Axminster, United Kingdom)-and the TiVi imaging system (WheelsBridge AB, Linkoping, Sweden). Both imaging and point scanning by the devices are used to quantify the provoked reactions. Perfusion images of vasodilatation and vasoconstriction are acquired with both LDLS and FLPI, while TiVi images are acquired with the TiVi imager. Time acquisitions of an averaged region of interest are acquired for temporal studies such as the reactive hyperaemia. In contrast to the change in perfusion over time with pressure, the TiVi imager shows a different response due its measurement of blood concentration rather than perfusion. The responses can be explained by physiological understanding. Although the three devices sample different compartments of tissue, and output essentially different variables, comparisons can be seen between the three systems. The LDLS system proves to be suited to measurement of perfusion in deeper vessels, while FLPI and TiVi showed sensitivity to more superficial nutritional supply. LDLS and FLPI are insensitive to the action of the vasoconstrictor, while TiVi shows the clear boundaries of the reaction. Assessment of the resolution, penetration depth, and acquisition rate of each instrument show complimentary features that should be taken into account when choosing a system for a particular clinical measurement.
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Affiliation(s)
- Jim O'Doherty
- University of Limerick, Tissue Optics and Microcirculation Imaging Facility, Department of Physics, National Technology Park, County Limerick, Ireland
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25
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Crandall JP, Shamoon H, Cohen HW, Reid M, Gajavelli S, Trandafirescu G, Tabatabaie V, Barzilai N. Post-challenge hyperglycemia in older adults is associated with increased cardiovascular risk profile. J Clin Endocrinol Metab 2009; 94:1595-601. [PMID: 19208733 PMCID: PMC2684470 DOI: 10.1210/jc.2008-1829] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
CONTEXT Post-challenge hyperglycemia (PCH) is common in older adults and is associated with increased cardiovascular disease (CVD) risk and total mortality. However, PCH is rarely recognized in clinical settings, and the glycemic exposure and CVD risk profile of elderly individuals with PCH has not been defined. OBJECTIVE The aim of the study was to characterize metabolic and CVD risk profile of elderly subjects with PCH and to determine the effect of acute postprandial metabolic changes on vascular biomarkers. DESIGN We conducted a cross-sectional study with a standard meal challenge protocol. PARTICIPANTS Older adults with normal glucose tolerance (n = 30) or PCH (fasting glucose <126 mg/dl and 2-h glucose >or=170 mg/dl; n = 28) participated in the study. MAIN OUTCOME MEASURES We assessed fasting and postprandial levels of glucose, insulin, lipids, high sensitivity C-reactive protein, plasminogen activator inhibitor-1, and adiponectin and endothelial function using reactive hyperemia peripheral arterial tonometry. RESULTS Normal glucose tolerance and PCH subjects were matched for age, sex, body mass index, and ethnicity. Fasting glucose (102 +/- 3 vs. 93 +/- 2 mg/dl; P < 0.001) and glycosylated hemoglobin (5.7 vs. 5.4%; P = 0.01) were modestly higher in the PCH group, which was also more insulin resistant (homeostasis model assessment for insulin resistance, 7.0 +/- 1.3 vs. 4.1 +/- 0.6; P = 0.03). Fasting high sensitivity C-reactive protein was higher (2.6 +/- 0.5 vs. 1.3 +/- 0.2 mg/dl; P = 0.05), and adiponectin was lower (11.6 +/- 1.6 vs. 14.0 +/- 1.3 microg/ml; P = 0.03) in subjects with PCH. Peak and 6-h postprandial area under the curve glucose, insulin, and lipids were higher in PCH subjects, who also had higher fasting and postprandial levels of plasminogen activator inhibitor-1. Reactive hyperemia peripheral arterial tonometry declined postprandially only in PCH. CONCLUSIONS Older adults with PCH experience significant fasting and postprandial metabolic dysregulation, which is accompanied by a proatherosclerotic and prothrombotic vascular profile.
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Affiliation(s)
- Jill P Crandall
- The Institute of Aging Research, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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26
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Torigoe M, Matsui H, Ogawa Y, Murakami H, Murakami R, Cheng XW, Numaguchi Y, Murohara T, Okumura K. Impact of the high-molecular-weight form of adiponectin on endothelial function in healthy young men. Clin Endocrinol (Oxf) 2007; 67:276-81. [PMID: 17547685 DOI: 10.1111/j.1365-2265.2007.02876.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Adiponectin is an adipocyte-derived, antiatherogenic protein that is present in plasma as a large multimeric structure of high molecular weight (HMW) and in a trimer or hexamer form (non-HMW). The biological activities of these isoforms have not yet been elucidated. We therefore examined the effect of these isoforms on endothelial function in healthy young men. DESIGN One hundred apparently healthy young men without overt cardiovascular disease (mean age 30 years) were recruited in this cross-sectional study based on voluntary enrollment. MEASUREMENTS We evaluated endothelial function estimated by flow-mediated dilatation (FMD) of the brachial artery during reactive hyperaemia, and measured total and HMW adiponectin levels. RESULTS Both HMW and non-HMW adiponectin levels showed a significant, inverse correlation with body mass index (BMI). FMD was significantly correlated with fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), malondialdehyde-modified low density lipoprotein (MDA-LDL), LDL particle size, and HMW adiponectin (r = 0.320, P = 0.001), but not non-HMW adiponectin (r = 0.125, P = 0.22). In multivariate analysis, HMW adiponectin and MDA-LDL were selected as independent factors capable of influencing FMD. No variables determined nitroglycerin-induced dilatation. CONCLUSIONS These results suggest that even in young men, plasma adiponectin levels can predict endothelial dysfunction before any overt vascular disease has occurred. HMW adiponectin may be more useful as a marker of endothelial dysfunction than total adiponectin.
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Affiliation(s)
- Masayuki Torigoe
- Department of Cardiology, Nagoya University Graduate School of Medicine, 65 Tsusumai-cho, Showa-ku, Nagoya 466-8550, Japan
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27
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Albillos A, Bañares R, González M, Catalina MV, Pastor O, Gonzalez R, Ripoll C, Bosch J. The extent of the collateral circulation influences the postprandial increase in portal pressure in patients with cirrhosis. Gut 2007; 56:259-64. [PMID: 16837532 PMCID: PMC1856769 DOI: 10.1136/gut.2006.095240] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 05/26/2006] [Accepted: 06/14/2006] [Indexed: 12/11/2022]
Abstract
BACKGROUND In cirrhosis, repeated flares of portal pressure and collateral blood flow provoked by postprandial hyperaemia may contribute to variceal dilation and rupture. AIM To examine the effect of the extent of the collateral circulation on the postprandial increase in portal pressure observed in cirrhosis. PATIENTS AND METHODS The hepatic venous pressure gradient (HVPG), hepatic blood flow and azygos blood flow were measured in 64 patients with cirrhosis before and after a standard liquid meal. RESULTS Peak increases in HVPG (median+14.9%), hepatic blood flow (median+25.4%), and azygos blood flow (median+32.2%) occurred at 30 min after the meal. Compared with patients with marked postprandial increase in HVPG (above the median, n = 32), those showing mild (<15%, n = 32) increase in HVPG had a higher baseline azygos flow (p<0.01) and underwent a greater postprandial increase in azygos flow (p<0.02). Hepatic blood flow increased similarly in both groups. Postprandial increases in HVPG were inversely correlated (p<0.001) with both baseline azygos flow (r = -0.69) and its postprandial increase (r = -0.72). Food intake increased nitric oxide products in the azygos (p<0.01), but not in the hepatic vein. Large varices (p<0.01) and previous variceal bleeding (p<0.001) were more frequent in patients with mild increase in HVPG. CONCLUSIONS Postprandial hyperaemia simultaneously increases HVPG and collateral flow. The extent of the collateral circulation determines the HVPG response to food intake. Patients with extensive collateralisation show less pronounced postprandial increases in HVPG, but associated with marked flares in collateral flow. Collateral vessels preserve their ability to dilate in response to increased blood flow.
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Affiliation(s)
- Agustín Albillos
- Hospital Universitario Ramón y Cajal, Universidad de Alcalá, Madrid, Spain.
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28
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Prázný M, Ježková J, Horová E, Lazárová V, Hána V, Kvasnicka J, Pecen L, Marek J, Skrha J, Krsek M. Impaired microvascular reactivity and endothelial function in patients with Cushing's syndrome: influence of arterial hypertension. Physiol Res 2007; 57:13-22. [PMID: 17223725 DOI: 10.33549/physiolres.931126] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [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: 11/25/2022] Open
Abstract
The aim of the study was to evaluate skin microvascular reactivity (MVR) and possible influencing factors (fibrinolysis, oxidative stress, and endothelial function) in patients with Cushing's syndrome. Twenty-nine patients with active Cushing's syndrome (ten of them also examined after a successful operation) and 16 control subjects were studied. Skin MVR was measured by laser Doppler flowmetry during post-occlusive (PORH) and thermal hyperemia (TH). Malondialdehyde and Cu,Zn-superoxide dismutase were used as markers of oxidative stress. Fibrinolysis was estimated by tissue plasminogen activator (tPA) and its inhibitor (PAI-1). N-acetyl-beta-glucosaminidase, E-selectin, P-selectin, and ICAM-1 were used as markers of endothelial function. Oxidative stress and endothelial dysfunction was present in patients with hypercortisolism, however, increased concentration of ICAM-1 was also found in patients after the operation as compared to controls (290.8+/-74.2 vs. 210.9+/-56.3 ng.ml(-1), p<0.05). Maximal perfusion was significantly lower in patients with arterial hypertension during PORH and TH (36.3+/-13.0 vs. 63.3+/-32.4 PU, p<0.01, and 90.4+/-36.6 vs. 159.2+/-95.3 PU, p<0.05, respectively) and similarly the velocity of perfusion increase during PORH and TH was lower (3.2+/-1.5 vs. 5.2+/-3.4 PU.s(-1), p<0.05, and 0.95+/-0.6 vs. 1.8+/-1.1 PU.s(-1), p<0.05, respectively). The most pronounced impairment of microvascular reactivity was present in patients with combination of arterial hypertension and diabetes mellitus.
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Affiliation(s)
- M Prázný
- Third Department of Internal Medicine, First Faculty of Medicine, Prague, Czech Republic.
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29
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Rodríguez L, Salvador L, Valero R, Carrero E, Fontanals J, Fàbregas N. [Behaviour of near-infrared cerebral oximetry readings during percutaneous carotid angioplasty]. Rev Esp Anestesiol Reanim 2006; 53:633-8. [PMID: 17302077] [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: 05/14/2023]
Abstract
BACKGROUND Transluminal percutaneous carotid angioplasty and stenting (CAS) carries a risk of cerebral ischemia, hemorrhage, or edema due to relative hyperemia and hemodynamic instability during and after the procedure. Noninvasive monitoring of near-infrared regional cerebral oxygen saturation (SrO2) offers an indirect way to estimate cerebral blood flow. OBJECTIVE To evaluate the behaviour of SrO2 during CAS and the usefulness of this variable for continuous monitoring of cerebral blood flow variation and neurological status. MATERIAL AND METHODS Prospective study of 25 patients scheduled for unilateral CAS under monitored anesthesia care. SrO, and other hemodynamic and clinical data were recorded. A change in SrO2 (deltaSrO2) of 15% or more in comparison with the baseline value and lasting more than 30 seconds was considered clinically significant. Neurological complications in the first 24 hours were also registered. RESULTS Baseline SrO, ranged from 51% to 75%. With administration of papaverine SrO2 values increased by a mean (SD) of 5.6% (6%) (P<.05 vs baseline). They decreased during angioplasty, -2.5% (5.7%) (P<.05 vs baseline), increased after 5 minutes, and fell again at 30 minutes to a level 3% (6.54%) above baseline. Two patients showed signs of elevated intracranial pressure after the procedures and also had ASrO2 readings exceeding 15%; measures to lower arterial hypertension reduced SrO2 in these patients. CONCLUSION High interindividual variability of absolute SrO2 values has been confirmed. SrO, fluctuates with maneuvers that change cerebral blood flow in the same way. Changes can precede the onset of other clinical signs.
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Affiliation(s)
- L Rodríguez
- Servicio de Anestesiología, Reanimación y Tratamiento del Dolor, Hospital Clinic i Provincial, Universitat de Barcelona.
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30
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Tousoulis D, Antoniades C, Vasiliadou C, Kourtellaris P, Koniari K, Marinou K, Charakida M, Ntarladimas I, Siasos G, Stefanadis C. Effects of atorvastatin and vitamin C on forearm hyperaemic blood flow, asymmentrical dimethylarginine levels and the inflammatory process in patients with type 2 diabetes mellitus. Heart 2006; 93:244-6. [PMID: 16914485 PMCID: PMC1861391 DOI: 10.1136/hrt.2006.093112] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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31
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Ledermann HP, Schulte AC, Heidecker HG, Aschwanden M, Jäger KA, Scheffler K, Steinbrich W, Bilecen D. Blood Oxygenation Level–Dependent Magnetic Resonance Imaging of the Skeletal Muscle in Patients With Peripheral Arterial Occlusive Disease. Circulation 2006; 113:2929-35. [PMID: 16785340 DOI: 10.1161/circulationaha.105.605717] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Blood oxygenation level–dependent (BOLD) magnetic resonance imaging (MRI) has been used to measure T2* changes in skeletal muscle tissue of healthy volunteers. The BOLD effect is assumed to primarily reflect changes in blood oxygenation at the tissue level. We compared the calf muscle BOLD response of patients with peripheral arterial occlusive disease (PAOD) to that of an age-matched non-PAOD group during postischemic reactive hyperemia.
Methods and Results—
PAOD patients (n=17) with symptoms of intermittent calf claudication and an age-matched non-PAOD group (n=11) underwent T2*-weighted single-shot multiecho planar imaging on a whole-body magnetic resonance scanner at 1.5 T. Muscle BOLD MRI of the calf was performed during reactive hyperemia provoked by a cuff-compression paradigm. T2* maps were generated with an automated fitting procedure. Maximal T2* change (ΔT2*
max
) and time to peak to reach ΔT2*
max
for gastrocnemius, soleus, tibial anterior, and peroneal muscle were evaluated. Compared with the non-PAOD group, patients revealed significantly lower ΔT2*
max
-values, with a mean of 7.3±5.3% versus 13.1±5.6% (
P
<0.001), and significantly delayed time-to-peak values, with a mean of 109.3±79.3 versus 32.2±13.3 seconds (
P
<0.001).
Conclusions—
T2* time courses of the muscle BOLD MRI signal during postocclusive reactive hyperemia revealed statistically significant differences in the key parameters (ΔT2*
max
; time to peak) in PAOD patients compared with age-matched non-PAOD controls.
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Affiliation(s)
- Hans-Peter Ledermann
- Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
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32
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Antoniades C, Tousoulis D, Marinou K, Stefanadi E, Ntarladimas I, Latsios G, Konniari K, Papageorgiou N, Siasos G, Stefanadis C. Effects of lipid profile on forearm hyperemic response in young subjects. Hellenic J Cardiol 2006; 47:152-7. [PMID: 16862822] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
INTRODUCTION The role of lipids in atherogenesis is now well established. However, the exact mechanisms by which different lipoproteins affect endothelial function and induce atherogenesis are still not well understood. In the present study we examined the effect of lipid profile on forearm vasodilatory response to reactive hyperemia, an index of endothelial function, in a cohort of young, low-risk adults. METHODS One hundred sixty seven healthy subjects were included in the study. The effect of total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides, apolipoprotein (apo)-A1, apo-B and apo-E on endothelial function and inflammatory process was examined. Endothelial function was evaluated by determining forearm vasodilatory response to reactive hyperemia (RH%) using gauge-strain plethysmography. RH% was defined as the % change of forearm blood flow from baseline to the maximum flow during post-ischemic hyperemia. Endothelium independent dilatation in response to nitroglycerin (NTG%) was defined as the % change of forearm blood flow from baseline to the maximum flow after sublingual nitroglycerin administration. RESULTS RH% was correlated with HDL (r = 0.267, p = 0.001), LDL (r = 0.355, p = 0.0001), triglycerides (rho = -0.366, p = 0.0001), apo-Al (r = 0.240, p = 0.004) and apo-B (r = -0.277, p = 0.005). NTG% was not affected by serum lipid levels. In multivariate linear regression, LDL (beta = -0.217 [SE: 0.098], p = 0.028), apo-A1 (beta = 0.277 [SE: 0.124], p = 0.027) and age (beta = 0.916 [SE:0.369], p = 0.015) were independent predictors for RH% in this population (R2 for the model: 0.243, p = 0.0001). CONCLUSIONS Elevated lipid levels decrease forearm vasodilatory response to reactive hyperemia. Apolipoproteins, and especially apo-Al, are important determinants of endothelial function in these subjects, independently of LDL, HDL and triglycerides, implying that full measurement of the lipid profile may be of great importance in risk stratification of young individuals.
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Affiliation(s)
- Charalambos Antoniades
- Athens University Medical School, 1st Cardiology Department, Hippokration Hospital, Athens, Greece
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Antoniades C, Tousoulis D, Tountas C, Tentolouris C, Toutouza M, Vasiliadou C, Tsioufis C, Toutouzas P, Stefanadis C. Vascular endothelium and inflammatory process, in patients with combined Type 2 diabetes mellitus and coronary atherosclerosis: the effects of vitamin C. Diabet Med 2004; 21:552-8. [PMID: 15154938 DOI: 10.1111/j.1464-5491.2004.01201.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS Type 2 diabetes mellitus (DM) and coronary artery disease (CAD) are both associated with endothelial dysfunction and elevated oxidative and inflammatory state. We examined the effect of vitamin C on endothelial function and levels of soluble vascular cell adhesion molecule (sVCAM-1), interleukin-6 (IL-6) and tumour necrosis factor (TNF-alpha), in DM patients with or without CAD and in non-diabetic subjects. METHODS Thirty-seven patients with DM + CAD, 17 patients with DM without CAD and 21 non-diabetic subjects were divided into groups receiving vitamin C 2 g/day or no anti-oxidant for 4 weeks. Forearm blood flow was determined using venous occlusion gauge-strain plethysmography. Forearm vasodilatory response to reactive hyperemia was considered as index of endothelium-dependent dilation. RESULTS Baseline levels of IL-6 and TNF-alpha were significantly higher in patients with DM + CAD compared with patients with DM (P < 0.01) or non-diabetic subjects (P < 0.01). IL-6 and TNF-alpha levels were also higher in DM compared with non-diabetic subjects (P < 0.05). sVCAM-1 levels were lower in non-diabetic controls compared with DM + CAD (P < 0.05) or DM (P < 0.05). Reactive hyperaemia was higher in non-diabetic controls compared with DM + CAD (P < 0.001) or DM (P < 0.001). Vitamin C significantly increased reactive hyperaemia only in the DM + CAD group, while it had no effect on serum levels of sVCAM-1, TNF-alpha and IL-6 in any of the groups. CONCLUSIONS Type 2 diabetes mellitus is associated with impaired endothelial function and increased levels of TNF-alpha, IL-6 and sVCAM-1, especially in patients with DM and CAD. Vitamin C significantly increased forearm vasodilatory response to reactive hyperaemia only in patients with combined DM and CAD.
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Affiliation(s)
- C Antoniades
- Cardiology Department, Athens University Medical School, Greece
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Cheng X, Mao JM, Xu X, Elmandjra M, Bush R, Christenson L, O'keefe B, Bry J. Post-occlusive reactive hyperemia in patients with peripheral vascular disease. Clin Hemorheol Microcirc 2004; 31:11-21. [PMID: 15272149] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
We measured tissue oxygen saturation (StO2) changes during a post-occlusive reactive hyperemia (PORH) test on lower extremities of peripheral vascular disease (PVD) patients and healthy controls. The StO2 changes were measured by the near-infrared tissue oximeter prototyped by ViOptix Inc. We found that PVD indicators may include the post-occlusive StO2 reperfusion rate, the time duration of the reperfusion phase in a PORH test, and the StO2 dispersion rate in reactive hyperemia. We suggest critical values of these indicators for PVD assessments.
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Affiliation(s)
- Xuefeng Cheng
- ViOptix Inc., 44061-B Old Warm Spring Blvd., Fremont, CA 94538, USA
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35
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Korkushko OV, Sahach VF, Lishnevs'ka VI. [Some mechanisms of the development of endothelial disfunction in aging]. Fiziol Zh (1994) 2004; 50:43-8. [PMID: 15174205] [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: 04/29/2023]
Abstract
Taking into consideration age-related changes in endothelium, the ability of endothelium to produce vasoactive substances has been studied in healthy subjects of various age. Under experimental conditions, the activity of constitutive and inducible NO-synthase has been studied as well. The clinical part of the study involved investigation of 38 healthy subjects aged 60-79. The study has been designed to investigate vasomotor function of the endothelium, the levels of endothelin-1, NO2, prostacyclin, thromboxan, the level of adhesive molecules and inhibitor of tissue plasminogen activator. The levels of endothelial and inducible NO-synthases in tissues of the myocardium and the aorta has been investigated in healthy rats of various age. The data obtained show a decrease in the production of relaxation factors: NO and prostacyclin with aging. An important mechanism of deterioration of NO-synthesizing function of the endothelium is a decrease in endothelial NOS activity. The synthesis of endothelial vasoconstricting agents increased with ageing. This in combination with decreased production of vasodilating substances results in deterioration of defence properties of the endothelium. The increase in titer of adhesive molecules and inhibitors of tissue plasminogen activator testifies to age-dependent deterioration of anti-inflammatory and antithrombotic activities of the endothelium.
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Wassmann S, Ribaudo N, Faul A, Laufs U, Böhm M, Nickenig G. Effect of atorvastatin 80 mg on endothelial cell function (forearm blood flow) in patients with pretreatment serum low-density lipoprotein cholesterol levels <130 mg/dl. Am J Cardiol 2004; 93:84-8. [PMID: 14697473 DOI: 10.1016/j.amjcard.2003.09.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The effect of 6-week treatment with 80 mg/day atorvastatin on vascular function in the forearm was investigated in 18 patients with mean pretreatment serum low-density lipoprotein cholesterol concentrations of 112 +/- 4 mg/dl in a double-blind, placebo-controlled, randomized study. Statin treatment improved hyperemic forearm blood flow and decreased serum markers of oxidative stress and inflammation.
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Affiliation(s)
- Sven Wassmann
- Medizinische Klinik und Poliklinik, Innere Medizin III, Universitätskliniken des Saarlandes, Homburg/Saar, Germany.
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Stücker M, von Rothenburg TH, Moll C, Bechara FG, Hoffmann K, Altmeyer P. Effects of localized cutaneous vascular alteration on reactive hyperemia. Clin Hemorheol Microcirc 2004; 30:33-8. [PMID: 14967881] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
BACKGROUND Cutaneous microcirculation shows a distinctive spatiotemporal inhomogeneity. Therefore provocation tests are necessary to receive significant and reproducible data. The present study investigated the effect of localized cutaneous vascular alteration, like in psoriasis vulgaris, on different parameters of reactive hyperemia (peak capillary blood cell velocity [pCBV], postocclusive reactive hyperemia [PRH%], and time to peak capillary blood cell velocity [tpCBV]). MATERIAL AND METHODS Psoriatic plaques and normal skin on the contralateral side of 20 patients with psoriasis vulgaris were examined by Laser Doppler Anemometry. Capillary blood cell velocity was measured before suprasystolic occlusion and during postocclusive hyperemia. RESULTS Compared to normal skin psoriatic plaques showed a significant increase of peak capillary blood cell velocity (pCBV, normal skin: 0.89+/-0.23 mm/s, psoriatic plaque: 2.03+/-0.94 mm/s), resting capillary blood cell velocity (rCBV, normal skin: 0.43+/-0.12 mm/s psoriatic plaque: 0.72+/-0.20 mm/s) and postocclusive reactive hyperemia (PRH%, normal skin: 107%, psoriatic plaque: 180%). The time to peak capillary blood cell velocity (tpCBV) during reactive hyperemia did not change significantly. CONCLUSION In reactive hyperemia, changing of pCBV and PRH% combined with unaltered tCBV indicate a dysfunction of cutaneous microcirculation. In contrast acute closure of upper and lower arterial extremity show a changed tCBV with stable pCBV and PRH%.
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Affiliation(s)
- M Stücker
- Department of Dermatology and Allergology, Ruhr-University Bochum, Germany.
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38
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Abstract
BACKGROUND Consumption of flavonoid-rich beverages, including tea and red wine, has been associated with a reduction in coronary events, but the physiological mechanism remains obscure. Cocoa can contain extraordinary concentrations of flavanols, a flavonoid subclass shown to activate nitric oxide synthase in vitro. OBJECTIVE To test the hypothesis that flavanol-rich cocoa induces nitric-oxide-dependent vasodilation in humans. DESIGN The study prospectively assessed the effects of Flavanol-rich cocoa, using both time and beverage controls. Participants were blinded to intervention; the endpoint was objective and blinded. METHODS Pulse wave amplitude was measured on the finger in 27 healthy people with a volume-sensitive validated calibrated plethysmograph, before and after 5 days of consumption of Flavanol-rich cocoa [821 mg of flavanols/day, quantitated as (-)-epicatechin, (+)-catechin, and related procyanidin oligomers]. The specific nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) was infused intravenously on day 1, before cocoa, and on day 5, after an acute ingestion of cocoa. RESULTS Four days of flavanol-rich cocoa induced consistent and striking peripheral vasodilation (P = 0.009). On day 5, pulse wave amplitude exhibited a large additional acute response to cocoa (P = 0.01). L-NAME completely reversed this vasodilation (P = 0.004). In addition, intake of flavanol-rich cocoa augmented the vasodilator response to ischemia. Flavanol-poor cocoa induced much smaller responses (P = 0.005), and none was induced in the time-control study. Flavanol-rich cocoa also amplified the systemic pressor effects of L-NAME (P = 0.005). CONCLUSION In healthy humans, flavanol-rich cocoa induced vasodilation via activation of the nitric oxide system, providing a plausible mechanism for the protection that flavanol-rich foods induce against coronary events.
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Affiliation(s)
- Naomi D L Fisher
- Department of Medicine, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA.
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39
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Tousoulis D, Antoniades C, Tountas C, Bosinakou E, Kotsopoulou M, Toutouzas P, Stefanadis C. Vitamin C affects thrombosis/ fibrinolysis system and reactive hyperemia in patients with type 2 diabetes and coronary artery disease. Diabetes Care 2003; 26:2749-53. [PMID: 14514574 DOI: 10.2337/diacare.26.10.2749] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To examine the effect of vitamin C on forearm vasodilatory response to reactive hyperemia and on plasma level of plasminogen activator inhibitor 1 (PAI-1), von Willebrand factor (vWF), tissue plasminogen activator (tPA), antithrombin III (ATIII), proteins C and S, and factors V (fV) and VII (fVII) in patients with both type 2 diabetes and CAD. RESEARCH DESIGN AND METHODS A total of 39 patients with type 2 diabetes and CAD were divided into two groups and received vitamin C (2 g/day) or no antioxidant for 4 weeks. Forearm blood flow was determined using venous occlusion gauge-strain plethysmography at baseline and after treatment. Forearm vasodilatory response to reactive hyperemia (RH%) or nitrate (NTG%) was defined as the percent change of flow from baseline to the maximum flow during reactive hyperemia or after administration of nitrate, respectively. Biochemical markers were determined by enzyme-linked immunosorbent assay (ELISA) or other standard methods. RESULTS RH% was significantly increased after treatment with vitamin C (from 62.4 +/- 7.2 to 83.1 +/- 9.3%, P = 0.024) but remained unaffected in the control group. Vitamin C decreased plasma levels of fV (from 143 +/- 5.4 to 123 +/- 6.03%, P = 0.038), vWF (from 133.5 +/- 14.5 to 109.5 +/- 11.4%, P = 0.016), and tPA (from 12.3 +/- 0.99 to 8.40 +/- 0.60 ng/ml, P = 0.001), whereas these levels remained unaffected in the control group. The changes in RH%, vWF, and tPA were significantly greater (P = 0.028, 0.036, and 0.007, respectively) in the vitamin C-treated group than in the control group. Levels of ATIII, proteins S and C, fVII, and PAI-1 remained unchanged in all groups. CONCLUSIONS Short-term treatment with high doses of vitamin C improved RH% and decreased plasma levels of tPA and vWF in patients with type 2 diabetes and CAD.
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Affiliation(s)
- Dimitris Tousoulis
- Cardiology Department, Athens University Medical School, Hippokration Hospital, Athens, Greece.
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Sahuquillo J, Amorós S, Poca MA, Mena MP, Ibañez J, Báguena M, Domínguez L. Coexistence of regional cerebral hypoxia with normal or hyperemic brain detected by global monitoring methods. Analysis of apparently contradictory findings based on the Siggaard-Andersen model of tissue hypoxia. Acta Neurochir Suppl 2003; 81:303-5. [PMID: 12168332 DOI: 10.1007/978-3-7091-6738-0_77] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
The aim of our study was to perform and in-depth analysis of several episodes of regional brain hypoxia detected by monitoring brain partial pressure of oxygen (PtiO2) in which simultaneous measurements of cerebral oxygen extraction fraction (O2EF) suggested a normally perfused or even a hyperemic brain. To gain deeper insight into these episodes, we used the model of tissue hypoxia described by Siggaard-Andersen. In 244 simultaneous measurements, 31 episodes (12.7%) of brain hypoxia (PtiO2 < or = 15 mmHg) were detected simultaneously with an O2EF within the normal range or below the lowest normal percentile. Using Siggaard-Andersen methodology, we classified 6 episodes (19%) as high-affinity hypoxia and 25 (81%) as shunt hypoxia or dysperfusion hypoxia. Siggaard-Andersen's comprehensive classification of tissue hypoxia can be used as an integrative model to build coherent algorithms for diagnosing and managing neurocritical patients that are at risk of brain hypoxia due to either intracranial or extracranial conditions.
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Affiliation(s)
- J Sahuquillo
- Department of Neurosurgery, Vall d'Hebron University Hospitals, Barcelona, Spain
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Abstract
In the present study we assessed the effect of physical training on Laser Doppler skin flux (LDF) and nitric oxide (NO) release, before and after 3 min of brachial artery occlusion. To this end we performed laser Doppler measurements and the venous plasma assay of nitrite/nitrate (NOx) on 10 sedentary healthy subjects and 10 endurance athletes. The sedentary control subjects had lower basal and post reperfusion levels of NOx as compared to athletes (mean +/- SE: 27.8 +/- 3.5 vs. 33.2 +/- 3.4, 48.6 +/- 7.9 vs. 60.1 +/- 10.1 micromol/L; p < 0.05). LDF at baseline was not significantly different in the two groups (157.5 +/- 7.9 and 176.64 +/- 26.7 PU for sedentary subjects and athletes, respectively) while post ischemic LDF was significantly lower in nonathletic subjects than in athletes (209.9 +/- 13 and 343.8 +/- 21.3 PU, p < 0.001). In both groups the hyperaemic stimulus significantly increased LDF and NOx levels (p < 0.01 and p < 0.05, respectively). The flow reserve, estimated as peak/basal LDF, was significantly lower in control subjects than in athletes (1.34 +/- 0.2 and 2.32 +/- 0.9, respectively, p < 0.01). In athletes, as opposed to sedentary subjects, a direct correlation was found between plasma NOx concentration and LDF both in basal conditions (r = 0.92; p < 0.001), and during hyperaemia (r = 0.84; p < 0.01). In conclusion, compared to sedentary subjects, athletes had an enhanced nitric oxide release. Hyperaemia increased LDF and nitric oxide levels both in sedentary subjects and in athletes.
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Affiliation(s)
- C Vassalle
- CNR Institute of Clinical Physiology, Pisa, Italy.
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Sejda T, Kovár J, Pitha J, Cífková R, Svandová E, Poledne R. The effect of an acute fat load on endothelial function after different dietary regimens in young healthy volunteers. Physiol Res 2002; 51:99-105. [PMID: 12071297] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Attention has recently been focused on endothelial function after a single high-fat meal, i.e. on the anticipated direct atherogenic effect of triglyceride-rich lipoproteins. Our study was designed to investigate the effect of a low-fat diet given for four weeks followed by a high-fat diet for another four weeks. At the end of each dietary period, a noninvasive ultrasound investigation of endothelial function of the brachial artery was performed along with laboratory tests. Endothelial function was measured immediately before the dietary load and after three and six hours in 11 healthy volunteers. The results were expressed as percentage of the changes in artery diameter at rest and during hyperemia; the data were processed using computer technology. When compared to the low-fat regimen, the total cholesterol content rose after the high-fat diet from 4.28 mmol/l to 5.15 mmol/l (p<0.05) in the whole group of volunteers. There was no difference between both dietary regimens in baseline triglycerides. The brachial artery dilatation under basal conditions was 5.26+/-2.88 mm after the high-fat diet compared with the value of 3.13+/-3.01 mm (p<0.05) after the low-fat diet. When measured individually endothelial function in the whole group of volunteers in the course of the day, the degree of arterial dilatation after one month on low-fat diet was 3.13+/-3.0%, 3.88+/-2.5% and 5.23+/-3.3% at single measurement. When comparing arterial dilatation at two closest measurements, a non-significant trend, p>0.05 was seen in either case. The following values were obtained after one month on the high-fat diet: 5.26+/-2.9%, 4.47+/-1.7%, and 6.2+/-3.6%; again showing a non-significant trend of p>0.05. In this study, a single high-fat meal at the different dietary regimen did not significantly influence the vasoreactivity of the brachial artery in young volunteers.
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Affiliation(s)
- T Sejda
- Third Department of Internal Medicine, Thomayer Memorial University Hospital, Prague, Czech Republic.
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Higashi Y, Sasaki S, Nakagawa K, Kimura M, Sasaki S, Noma K, Hara K, Matsuura H, Goto C, Oshima T, Chayama K. Severity of hypertension affects improved resistance artery endothelial function by angiotensin-converting enzyme inhibition. J Cardiovasc Pharmacol 2002; 39:668-76. [PMID: 11973410 DOI: 10.1097/00005344-200205000-00007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The purpose of this study was to determine whether there are differences in the restoration of endothelial function by angiotensin-converting enzyme inhibition based on the severity of hypertension. Forearm blood flow (FBF) was measured in 69 patients with essential hypertension (mild, n = 23; moderate, n = 29; and severe, n = 17 randomly assigned to treatment with either imidapril or amlodipine for 24 weeks in a double-blind fashion during reactive hyperemia and after sublingual administration of nitroglycerin. Imidapril augmented the FBF response to reactive hyperemia after 24 weeks of treatment in the mild and moderate hypertensive groups, but not in the severe hypertensive group. The augmentation of the FBF response to reactive hyperemia induced by imidapril was significantly greater in the moderate hypertensive group than in the mild hypertensive group. Amlodipine did not alter the FBF response to reactive hyperemia. The increase in FBF after the sublingually administered nitroglycerin was similar in all groups. The infusion of NG-monomethyl-l-arginine, a nitric oxide synthase inhibitor, abolished the enhancement of reactive hyperemia in the mild and moderate hypertensive groups treated with imidapril. These findings suggest that the effects of imidapril on endothelial function are affected by the severity of hypertension and that angiotensin-converting enzyme inhibitor-induced augmentation of reactive hyperemia may be due to increased nitric oxide production.
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Affiliation(s)
- Yukihito Higashi
- First Department of Internal Medicine, Hiroshima University, Faculty of Medicine, Minami-ku, Japan.
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Zuzak KJ, Schaeberle MD, Lewis EN, Levin IW. Visible reflectance hyperspectral imaging: characterization of a noninvasive, in vivo system for determining tissue perfusion. Anal Chem 2002; 74:2021-8. [PMID: 12033302 DOI: 10.1021/ac011275f] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.2] [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: 11/30/2022]
Abstract
We characterize a visible reflectance hyperspectral imaging system for noninvasive, in vivo, quantitative analysis of human tissue in a clinical environment. The subject area is illuminated with a quartz-tungsten-halogen light source, and the reflected light is spectrally discriminated by a liquid crystal tunable filter (LCTF) and imaged onto a silicon charge-coupled device detector. The LCTF is continuously tunable within its useful visible spectral range (525-725 nm) with an average spectral full width at half-height bandwidth of 0.38 nm and an average transmittance of 10.0%. A standard resolution target placed 5.5 ft from the system results in a field of view with a 17-cm diameter and an optimal spatial resolution of 0.45 mm. The measured reflectance spectra are quantified in terms of apparent absorbance and formatted as a hyperspectral image cube. As a clinical example, we examine a model of vascular dysfunction involving both ischemia and reactive hyperemia during tissue reperfusion. In this model, spectral images, based upon oxyhemoglobin and deoxyhemoblobin signals in the 525-645-nm region, are deconvoluted using a multivariate least-squares regression analysis to visualize the spatial distribution of the percentages of oxyhemoglobin and deoxyhemoglobin in specific skin tissue areas.
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Affiliation(s)
- Karel J Zuzak
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Murata P, Kase Y, Ishige A, Sasaki H, Kurosawa S, Nakamura T. The herbal medicine Dai-kenchu-to and one of its active components [6]-shogaol increase intestinal blood flow in rats. Life Sci 2002; 70:2061-70. [PMID: 12148698 DOI: 10.1016/s0024-3205(01)01552-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [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: 11/25/2022]
Abstract
The present study investigated the effects of the herbal medicine Dai-kenchu-to (DKCT) and its 4 individual ingredients on intestinal blood flow (IBF) in rats by laser Doppler flowmetry. Intraduodenal administration of DKCT (30, 100 and 300 mg/kg) increased IBF in a dose-dependent manner, whereas the mean arterial blood pressure was not affected. One of the ingredients in DKCT is dried ginger rhizome (150 mg/kg), whose main component is [6]-shogaol (2 mg/kg), both of which showed similar effects to those shown by DKCT, while the other ingredients in DKCT only slightly increased IBF or had no effect. The calcitonin gene-related peptide (CGRP) receptor antagonist, CGRP (8-37), completely abolished the hyperemia induced by DKCT, dried ginger rhizome and [6]-shogaol. However, the vasoactive intestinal polypeptide (VIP) receptor antagonist, [4-Cl-DPhe6, Leul7]-VIP, and atropine were less inhibitory than CGRP (8-37), and the substance P (SP) receptor antagonist, spantide, had no effect. The present study demonstrated that DKCT and one of its active components, [6]-shogaol, produced an increase in IBF which was mainly mediated by CGRP and suggests that DKCT may be useful in the treatment of intestinal ischemia-related diseases.
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Affiliation(s)
- Pin Murata
- R & D Division, Tsumura & Co, Ibaraki, Japan.
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De Michele M, Ascione L, Guarini P, Perrotta S, Tuccillo B. [Non-invasive evaluation of the endothelial function using high-resolution B-mode ultrasonography]. Ital Heart J Suppl 2001; 2:1155-60. [PMID: 11775406] [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: 02/23/2023]
Abstract
The vascular endothelium has a central role in regulating vasomotor tone, smooth muscle cell proliferation, platelet and leukocyte adhesion to the arterial wall, thrombosis and fibrinolysis. Disturbances of these endothelial functions have been suggested to be important in the early and advanced phases of atherosclerosis. The development of a simple, valid ultrasound-based method allowed to non-invasively evaluate endothelial function in a large number of individuals with traditional and non-traditional cardiovascular risk factors. The ultrasound technique measures changes in brachial artery diameter in response to an increase in blood flow (reactive hyperemia) and thus in shear stress, which causes endothelium-dependent dilation. This methodology is not yet perfect. The critical issues today involve the definition of "normal values", and standardized scanning and reading protocols to reduce variability.
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Affiliation(s)
- M De Michele
- Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi Federico II.
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47
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Abstract
This study was designed to assess a possible correlation between flow-mediated endothelium-dependent vasodilation in the popliteal artery and the intima-media thickness of the common carotid artery. Impaired vasodilation is one of early markers of atherosclerosis that has not been studied on the popliteal artery. An increase in intima-media thickness of the common carotid artery is also considered to be an indication of early stages of atherosclerosis. With use of ultrasound, the diameter of the popliteal artery was measured at rest and during reactive hyperemia after 5-minute arterial occlusion. Subsequently, the intima-media thickness was measured in left common carotid arteries in 27 patients with hyperlipidemia, in 10 patients with confirmed coronary artery disease, and in 20 healthy individuals. In healthy individuals, popliteal artery diameter increased by mean of 6.6 +/- 3.5% (p < 0.01) in relation to hyperemia. In patients with hyperlipidemia before therapy and in patients with coronary disease, no increase in diameter occurred (mean, 0.44% and -1.6%, respectively). The difference between healthy individuals and patients was statistically significant at p < 0.001. The popliteal artery seems to respond similarly to the brachial artery. When comparing the change in popliteal artery diameter and intima-media thickness of common carotid arteries, a strong negative correlation (r = -0.5713, p < 0.001) was observed in all subjects.
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Affiliation(s)
- J Spácil
- 3rd Internal Department, General Faculty Hospital, 1st Medical Faculty, Charles University, Prague 2, Czech Republic.
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Martin H, Olander B, Norman M. Reactive hyperemia and interleukin 6, interleukin 8, and tumor necrosis factor-alpha in the diagnosis of early-onset neonatal sepsis. Pediatrics 2001; 108:E61. [PMID: 11581469 DOI: 10.1542/peds.108.4.e61] [Citation(s) in RCA: 55] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To evaluate the diagnostic value of peripheral circulatory reactive hyperemia and serum levels of interleukin-6 (IL-6), IL-8, and tumor necrosis factor-alpha (TNF-alpha) in early-onset neonatal sepsis. METHODS Reactive hyperemia in the dorsal hand and serum levels of IL-6, IL-8, and TNF-alpha were studied in newborn infants (n = 32; gestational age 39 +/- 3 weeks) who had been admitted to the neonatal unit because of suspected sepsis <48 hours after birth. On admission, reactive hyperemia after a standardized arterial occlusion was measured with laser Doppler technique, and blood samples were taken for cytokine analyses. On the basis of predetermined criteria, the infants subsequently were classified as septic (n = 12) or not (n = 20). RESULTS The degree of reactive hyperemia was higher in the group with sepsis (median + 170% perfusion increase) than in that without (+37%). On admission, serum levels of IL-6, IL-8, and TNF-alpha all were higher in septic (median values: 1620, 331, and 22 pg/mL, respectively) than in nonseptic neonates (median values: 42, 63, and 13 pg/mL, respectively). In the group with sepsis, the degree of reactive hyperemia correlated to log IL-6 (r = 0.80) and log IL-8 values (r = 0.71). CONCLUSION Newborn infants with septicemia have increased reactive hyperemia and elevated cytokine levels very early in their disease. Reactive hyperemia in skin can be analyzed at the bedside and noninvasively and therefore may serve as an additional diagnostic tool in neonatal sepsis.
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Affiliation(s)
- H Martin
- Department of Women and Child Health, Division of Neonatology, Karolinska Hospital, Sweden.
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Abstract
Ultrasonic studies have shown that arterial compliance increases after prolonged ischemia. The objective of the present study was to develop an alternative plethysmographic method to investigate compliance, exploring validity and clinical applicability. Forearm pulse volume (FPV) and blood pressure (BP) were used to establish the FPV-BP relationship. Forearm arterial compliance (FAC) was measured, and the area under the FAC-BP curve (FAC(AUC)) was determined. The time course curve of compliance changes during reactive hyperemia was obtained by continuous measurements of FAC(AUC) for 20 s before and for 300 s after arterial occlusion. This technique allows us to effectively assess compliance changes during reactive hyperemia. Furthermore, the selected measurement protocol indicated the necessity for continuous measurements to detect "true" maximal FAC(AUC) changes. On multivariate analysis, preischemic FAC(AUC) was mainly affected by sex, peak FAC(AUC) was affected by sex and systolic BP, percent changes were affected by plasma high-density and low-density lipoprotein cholesterol, peak time was affected by age and body mass index, and descent time was affected by plasma triglyceride levels. The proposed technique is highly sensitive and well comparable with the generally accepted echotracking system. It may thus be considered as an alternative tool to detect and monitor compliance changes induced by arterial occlusion.
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Affiliation(s)
- D Baldassarre
- E. Grossi Paoletti Center, Department of Pharmacological Sciences, University of Milan, Milan 20133, Italy
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50
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Abstract
To clarify the vascular endothelial function in pregnant women with hypertensive disorders, we assessed the flow-mediated vasodilation in the radial artery and compared it with plasma fibronectin levels. We determined flow-mediated vasodilation by measuring the change in radial artery diameter during hyperemia in 58 normal pregnant women, 22 preeclamptic pregnant women, and 15 pregnant women with chronic hypertension. In 41 of the 95 pregnant women, we measured the plasma fibronectin levels. Flow-mediated vasodilation in preeclamptic women was significantly less than that in normal pregnant women (P:<0.001). In chronic hypertensive women, flow-mediated vasodilation was significantly less than that in normal pregnant women (P:<0.001) but more than that in preeclamptic women (P:<0.001). Flow-mediated vasodilation showed significant negative correlation with plasma fibronectin levels (P:<0.001, r=0.73). Our results indicate that the endothelial function can be noninvasively assessed in pregnant women with hypertensive disorders by measuring the flow-mediated vasodilation of the radial artery with high-resolution ultrasound.
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Affiliation(s)
- A Yoshida
- Department of Perinatal and Maternal Medicine, National Defense Medical College, Suzuka, Japan.
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