scholarly journals A Systematic Evaluation of Cutaneous Microcirculation in the Foot Using Post‐Occlusive Reactive Hyperemia

2021 ◽  
Author(s):  
Gayathri Balasubramanian ◽  
Nachiappan Chockalingam ◽  
Roozbeh Naemi
Keyword(s):  
Reactive Hyperemia ◽  
Systematic Evaluation ◽  
Cutaneous Microcirculation

scholarly journals PO-087 4-weeks hypoxia (HHL) training improves rowers’ cutaneous microcirculation

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Zhijun Meng ◽  
Binghong Gao
Keyword(s):  
Blood Flow ◽  
Endothelial Function ◽  
Forearm Blood Flow ◽  
Early Stage ◽  
Reactive Hyperemia ◽  
Peripheral Circulation ◽  
Reserve Capacity ◽  
Hypoxic Training ◽  
Cutaneous Microcirculation ◽  
Traditional Research

Objective Sport scientists always pay attention to cardiorespiratory and hematologic system on benefit of hypoxic training, but peripheral circulation may be one of these benefit, which is one cause of improving performance. So, in order to know whether or not hypoxic training affect athletes’ cutaneous microcirculation, we test rowers’ microcirculation for 4 weeks’ High Live-High Train-Low exercise(HHL). Methods The subject is 21 male rowers of Shanghai rowing team.12 of them take part in 4 weeks HHL (train and live at 2500m, exercise at 100m), while 9 of them train in normoxia. Forearm and leg cutaneous blood flow(CBF) was measured using a laser doppler flowmeter (PeriFlux600, Perimed, Sweden) at room temperature (22℃) with subject lying position and after testing in that position for at least 10min. We tested the forearm and leg blood flow, and also the blood flow when localized heating to 44℃ for 3 mins. Microvascular reactivity(MVR) was evaluated form the maximal post occlusive reactive hyperemia(PORH) following 3-min forearm ischemia produced by cuff inflation (200mm Hg). Similar procedures have been used by other investigators. Blood pressure was measured by brachial auscultation. SPO2 and heart rate was measured by a hand hold pulse oximeter (NONIN, 9500, USA) .The blood flow was measured 4 times, baseline, 1stweek, 3rdweek and post. Results Blood flow and CMBC of forearm of HHL increased significantly at 1stweek(8.9,13.0;112.0,151.0,P<0.05), but thigh and NOM group did not increase. The lowest and highest blood flow of PORH both increase at 1stweek(2,9,3.2;46.0,53.0;0.05<P<0.1). At 3rdweek, HHL group’s resting blood flow and CMBC of forearm is lower than 1stweek(9.3,13.0;124.5,151.0), but higher than pretraining, but velocity of blood flow decreased(8.2,9.2).  These results suggest at early stage of HHL, vasoconstriction may be dominant. But when rowers suffer more and more hypoxia, vasodilation and angiogenesis may play a key role in their skin blood flow. At 3rdweek after training, the blood flow and CMBC are similar with baseline. Conclusions 4 weeks HHL training of rowers increase forearm blood flow, but no thigh. This is because thigh is main working muscle of rowers, which may be affected by training status and fatigue. And also, PORH reserve capacity is an indicator of endothelial function. In this study, we find HHL rowers increase their PORH reserve capacity, which means endothelial function is improved by hypoxia training. So, besides the traditional research of Hematologic System on hypoxia training, we find 4 weeks HHL training increase forearm blood flow and improve endothelial function. This may be one mechanism of improving performance, which need more studies to confirm.

scholarly journals Oral Glucose Load and Human Cutaneous Microcirculation: An Insight into Flowmotion Assessed by Wavelet Transform

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 953
Author(s):  
Henrique Silva ◽  
Jernej Šorli ◽  
Helena Lenasi
Keyword(s):  
Wavelet Transform ◽  
Reactive Hyperemia ◽  
Oral Glucose ◽  
Oral Glucose Load ◽  
Glucose Load ◽  
Short Term ◽  
Doppler Flowmetry ◽  
Chronic Hyperglycemia ◽  
Cutaneous Microcirculation ◽  
The Impact

Microcirculation in vivo has been assessed using non-invasive technologies such as laser Doppler flowmetry (LDF). In contrast to chronic hyperglycemia, known to induce microvascular dysfunction, the effects of short-term elevations in blood glucose on microcirculation are controversial. We aimed to assess the impact of an oral glucose load (OGL) on the cutaneous microcirculation of healthy subjects, quantified by LDF and coupled with wavelet transform (WT) as an interpretation tool. On two separate occasions, sixteen subjects drank either a glucose solution (75 g in 250 mL water) or water (equal volume). LDF signals were obtained in two anatomical sites (forearm and finger pulp) before and after each load (pre-load and post-load, respectively), in resting conditions and during post-occlusive reactive hyperemia (PORH). The WT allowed decomposition of the LDF signals into their spectral components (cardiac, respiratory, myogenic, sympathetic, endothelial NO-dependent). The OGL blunted the PORH response in the forearm, which was not observed with the water load. Significant differences were found for the cardiac and sympathetic components in the glucose and water groups between the pre-load and post-load periods. These results suggest that an OGL induces a short-term subtle microvascular impairment, probably involving a modulation of the sympathetic nervous system.

scholarly journals Stable laser-Doppler flow-motion patterns in the human cutaneous microcirculation: Implications for prospective geroscience studies

2020 ◽  
Vol 107 (1) ◽  
pp. 134-144
Author(s):  
V. Tóth-Szűki ◽  
F. Bari ◽  
F. Domoki
Keyword(s):  
Reactive Hyperemia ◽  
The Body ◽  
Laser Doppler ◽  
Fast Fourier Transformation ◽  
Doppler Flowmetry ◽  
Microvascular Reactivity ◽  
Non Invasive ◽  
Cutaneous Microcirculation ◽  
Flow Motion ◽  
Temporal And Spatial

AbstractMicrovascular function has been assessed by determining the rhythmic oscillations in blood flow induced by the vasomotion of resistance vessels. Although laser-Doppler flowmetry (LDF) allows simple, non-invasive evaluation of this flow-motion in the cutaneous microcirculation, the temporal and spatial reproducibility of such assessments remains unclear.In the present study, we investigated cutaneous flow-motion in three consecutive years in eight skin regions using LDF in six healthy young volunteers. The characteristic flow-motion frequency was determined using fast-Fourier transformation. Additionally, in two years a more traditional measure of microvascular reactivity, postocclusive reactive hyperemia (PORH) was evoked in the forearm after transient brachial artery occlusion (1–2–3 min) induced by cuff inflation.Well-defined flow-motion was found in six regions showing significant differences in frequency: the highest flow-motion frequency was found in the frontal and temporal regions (8.0 ± 1.1 and 8.5 ± 1.0 cycles/min, cpm, respectively, mean ± SD) followed by the scapular, infraclavicular and coxal regions (7.5 ± 1.3; 6.7 ± 1.1 and 6.5 ± 1.2 cpm, respectively). The lowest, stable flow-motion was found in the posterior femoral region (5.5 ± 1.0 cpm), whereas flow-motion was detectable only sporadically in the limbs. The region-dependent flow-motion frequencies were very stable within individuals either between the body sides, or among the three measurements, only the infraclavicular region showed a small difference (114 ± 17%∗, % of value in 1st year; ∗P < 0.05). However, PORH indices differed after 2–3 min occlusions significantly in consecutive years.We report that flow-motion frequencies determined from LDF signals show both region-specificity and excellent intra-individual temporal and spatial reproducibility suggesting their usefulness for non-invasive follow-up of microvascular reactivity.

Image Analysis of Intramembrane Particles in Freeze-Fractured Biomembranes Using Computer Simulation Techniques

1975 ◽  
Vol 33 ◽  
pp. 214-215
Author(s):  
D.J. Benefiel ◽  
R.S. Weinstein
Keyword(s):  
Membrane Proteins ◽  
Freeze Fracture ◽  
Integral Membrane Proteins ◽  
Systematic Evaluation ◽  
Intramembrane Particles ◽  
Modeling Methods ◽  
Simulation Techniques ◽  
Freeze Fracture Electron Microscopy ◽  
Fracture Electron ◽  
Computer Simulation Techniques

Intramembrane particles (IMP or MAP) are components of most biomembranes. They are visualized by freeze-fracture electron microscopy, and they probably represent replicas of integral membrane proteins. The presence of MAP in biomembranes has been extensively investigated but their detailed ultrastructure has been largely ignored. In this study, we have attempted to lay groundwork for a systematic evaluation of MAP ultrastructure. Using mathematical modeling methods, we have simulated the electron optical appearances of idealized globular proteins as they might be expected to appear in replicas under defined conditions. By comparing these images with the apearances of MAPs in replicas, we have attempted to evaluate dimensional and shape distortions that may be introduced by the freeze-fracture technique and further to deduce the actual shapes of integral membrane proteins from their freezefracture images.

1849: Systematic Evaluation of 21μm Thulium Laser Device for Treatment of Benign Prostatic Enlargement in an Ex-VIVO Model

2007 ◽  
Vol 177 (4S) ◽  
pp. 614-614 ◽  
Author(s):  
Gunnar Wendt-Nordahl ◽  
Stefanie Huckele ◽  
Patrick Honeck ◽  
Peter Aiken ◽  
Thomas Knoll ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Systematic Evaluation ◽  
Thulium Laser ◽  
Laser Device ◽  
Benign Prostatic Enlargement ◽  
Ex Vivo Model ◽  
Prostatic Enlargement

Ventilatory threshold is related to walking tolerance in patients with intermittent claudication

VASA ◽  
2012 ◽  
Vol 41 (4) ◽  
pp. 275-281 ◽  
Author(s):  
da Rocha Chehuen ◽  
G. Cucato ◽  
P. dos Anjos Souza Barbosa ◽  
A. R. Costa ◽  
M. Ritti-Dias ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Intermittent Claudication ◽  
Lower Limb ◽  
Ventilatory Threshold ◽  
Reactive Hyperemia ◽  
Ankle Brachial Index ◽  
Metabolic Parameters ◽  
Walking Distance ◽  
The Relationship

Background: This study assessed the relationship between lower limb hemodynamics and metabolic parameters with walking tolerance in patients with intermittent claudication (IC). Patients and methods: Resting ankle-brachial index (ABI), baseline blood flow (BF), BF response to reactive hyperemia (BFRH), oxygen uptake (VO2), initial claudication distance (ICD) and total walking distance (TWD) were measured in 28 IC patients. Pearson and Spearman correlations were calculated. Results: ABI, baseline BF and BF response to RH did not correlate with ICD or TWD. VO2 at first ventilatory threshold and VO2peak were significantly and positively correlated with ICD (r = 0.41 and 0.54, respectively) and TWD (r = 0.65 and 0.71, respectively). Conclusions: VO2peak and VO2 at first ventilatory threshold, but not ABI, baseline BF and BFHR were associated with walking tolerance in IC patients. These results suggest that VO2 at first ventilatory threshold may be useful to evaluate walking tolerance and improvements in IC patients.

Systematic Evaluation of the Autism (Gluten-Free, Casein-Free) Diet

2011 ◽  
Author(s):  
Jessica L. Becraft ◽  
Natalie Rolider ◽  
Nicole L. Hausman
Keyword(s):  
Systematic Evaluation ◽  
Gluten Free

A Case Study on Web-based Learning Environment Evaluation in Higher Education: Learner Perspectives in a Private University in Malaysia.

2020 ◽  
Vol 1 (2) ◽  
pp. 18-33
Author(s):  
Zarina Che Imbi ◽  
Tse-Kian Neo ◽  
Mai Neo
Keyword(s):  
Higher Education ◽  
Learning Environment ◽  
Private University ◽  
Systematic Evaluation ◽  
Digital Learning ◽  
Mixed Method Research ◽  
Web Based ◽  
Web Based Learning ◽  
Kirkpatrick’S Model

In the era of digital learning, multimedia-based classroom has been commonly used in higher education including Malaysian higher education institutions. A case study has been performed to evaluate web-based learning using Level 1 to 3 of Kirkpatrick's model in a multi-disciplinary course at Multimedia University, Malaysia. In this study, mixed method research was employed in which triangulation was performed from multiple sources of data collection to give deeper understanding. Students perceived that learning with multimedia was enjoyable. They were also motivated in learning and engaged through the use of web module as multimedia was perceived to motivate them and make learning fun. Students showed significant improvements in their knowledge based on the pre-test and post-test results on learning evaluation. Students were perceived to transfer the learning from web-based learning into the learning outcome. The systematic evaluation can provide the feedback that educators and institution as a whole need to improve the learning environment and programme quality. This study contributes to the research field by adding another perspective in evaluations of web-based learning. It also provides empirical evidence on student perspectives, learning and behaviour in a private university. It demonstrated that the Kirkpatrick's model is useful as an evaluation tool to be used in higher education.

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