cutaneous blood flow

  • 文章类型: Journal Article
    This study was designed to identify the effects of a 12-h nicotine patch administration on cold induced vasodilation (CIVD) in healthy young chronic smokers following 16 h of abstinence from smoking. Two laser Doppler probes and temperature thermocouples were placed on the dorsal part of the distal phalanx of the middle and ring fingers of 7 smokers (>12 cigarettes/day). Following 16 h of abstinence from smoking, smokers were tested with and without administration of a 21 mg transdermal nicotine patch (NicoDerm® ). Each participant\'s right hand was immersed in cold (~5°C) water for 40 min. Cutaneous vascular conductance (CVC) was calculated from non-invasive arterial finger blood pressure and skin blood flow and expressed as a percentage of peak CVC observed during hand skin heating to 44°C. For comparison purposes, the CIVD response of a non-smoking cohort without nicotine patch (n = 10) was also examined. Baseline CVC was similar in smokers and non-smokers (27.8 ± 12.6 CVC % peak). The initial vasoconstriction during cold-water immersion decreased skin blood flow to 4.0 ± 3.9 CVC % peak in both smokers and non-smokers. The onset of CIVD in smokers (4.5 ± 1.5 min) was delayed compared to non-smoker (3.3 ± 0.8 min, p < .05). The area under the CVC %peak-time curve during cold-water immersion averaged 1250 ± 388 CVC %peak · min in non-smokers which was larger (p < .05) than smokers with or without nicotine (789 ± 542 and 862 ± 517 CVC %peak · min, respectively). Chronic smoking impaired the CIVD response to cold-water immersion of the hand; however, the impaired CIVD response in 16 h of abstinence from smoking was not influenced by application of a 21 mg transdermal nicotine patch.
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  • 文章类型: Journal Article
    BACKGROUND: The biophysical interaction induced by low energy pulsed electromagnetic field therapy (PEMFT) on the capillary microcirculation is not well understood. Several studies indicate a significant effect of PEMFT in patients with chronic medical conditions.
    OBJECTIVE: The aim of this study was to evaluate the influence of PEMFT on skin microcirculation in healthy volunteers.
    METHODS: 15 healthy participants were included. Nine PEMF treatments were applied over three weeks in an 48-hour interval. The PEMFT system (BEMER) was placed beneath one of the participants\' leg with the contralateral side serving as a control. A forty-minute application period was preceded by a 10-minute resting phase. Measuring was done using two Laser Doppler probes (LEA) placed on each anterior lateral thigh.
    RESULTS: All outcome parameters including flow, mixed venous oxygen saturation and relative venous hemoglobin showed a significant increase during the experiment when compared to the baseline values of the resting phase in both groups (p < 0.01). Comparing both groups, the measurement values during the experiment did not differ (p > 0.05) except for higher flow values in the control group (P = 0.03). Over time, baseline values of both groups showed no significant difference (p > 0.05).
    CONCLUSIONS: We found a significant increase of all measurement parameters during the study compared to the baseline values with no difference between the PEMF and control group.
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  • 文章类型: Journal Article
    背景:调查长期坚持法国营养与健康计划(PNNS)指南是否与更好的心血管健康相关。
    方法:一项嵌套在SU内的研究。VI.MAX2队列对无心血管危险因素的参与者进行。使用2007年和2012年验证的饮食评分对PNNS指南的长期依从性进行评估。包括连续遵守PNNS指南(PNNS)和不遵守PNNS指南的个人。移植眼压测定,心阻抗描记术,激光多普勒血流仪,心率,心率变异性,内皮功能用于评估心血管健康.
    结果:共有49名受试者(平均年龄65.4±5.6岁,75.5%的妇女)被包括在内。PNNS+组(n=26)年龄较大,BMI和脂肪量高于PNNS组,两组的代谢参数相似.在适应性爱之后,年龄,BMI,发现PNNS受试者的心率较低(60.2±8.0vs64.3±8.4次/分钟,p=0.042),较低的心率×收缩压乘积(7166±1323vs7788±1680次搏动×mmHg/min,p=0.009),舒张持续时间较长(66.7±3.1%vs64.6±4.1%的心动周期,p=0.049),和较短的张力时间指数(2145±489vs2307±428ms*mmHg,p=0.018)与PNNS组相比。
    结论:长期遵守PNNS指南对心率有有利的影响,舒张期,和心肌耗氧量.
    背景:NCT01579409。
    BACKGROUND: To investigate whether chronic adherence to the French Nutrition and Health Program (PNNS) guidelines was associated with better cardiovascular health.
    METHODS: A study nested within the SU.VI.MAX2 cohort was conducted on participants without cardiovascular risk factors. Long-term adherence to the PNNS guidelines was estimated using validated dietary scores from 2007 and 2012. Individuals who did (PNNS+) and did not (PNNS-) continuously adhere to the PNNS guidelines were included. Applanation tonometry, impedance cardiography, laser doppler flowmetry, heart rate, heart rate variability, endothelial function was used for the assessment of cardiovascular health.
    RESULTS: A total of 49 subjects (mean age 65.4 ± 5.6 years, 75.5% women) had been included. Those in the PNNS+ group (n=26) were older, had a higher BMI and fat mass than those in the PNNS- group, both groups had similar metabolic parameters. After adjusting for sex, age, and BMI, PNNS+ subjects were found to have a lower heart rate (60.2 ± 8.0 vs 64.3 ± 8.4 beats/min, p=0.042), a lower heart rate × systolic blood pressure product (7166 ± 1323 vs 7788 ± 1680 beats× mmHg/min, p = 0.009), a longer diastole duration (66.7 ± 3.1% vs 64.6 ± 4.1% of the cardiac cycle duration, p=0.049), and a shorter tension-time index (2145 ± 489 vs 2307 ± 428 ms * mmHg, p=0.018) compared to the PNNS- group.
    CONCLUSIONS: Long-term adherence to the PNNS guidelines had a favorable impact on heart rate, diastole duration, and myocardial oxygen consumption.
    BACKGROUND: NCT01579409.
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  • 文章类型: Journal Article
    We examined the interactive effects of mild hypothermia and hypoxia on finger vasoreactivity to local cold stress. Eight male lowlanders performed, in a counterbalanced order, a normoxic and a hypoxic (partial pressure of oxygen: ~12 kPa) hand cold provocation (consisting of a 30-min immersion in 8°C water), while immersed to the chest either in 21°C [cold trials; 0.5°C fall in rectal temperature (Trec) from individual preimmersion values], or in 35.5°C water, or while exposed to 27°C air. The duration of the trials was kept constant in each breathing condition. Physiological (Trec, skin temperature, cutaneous vascular conductance, oxygen uptake) and perceptual (thermal sensation and comfort, local pain, affective valence) reactions were monitored continually. Hypoxia accelerated the drop in Trec by ~14 min (P = 0.06, d = 0.67). In the air-exposure trials, hypoxia did not alter finger perfusion during the local cooling, whereas it impaired the finger rewarming response following the cooling (P < 0.01). During the 35.5°C immersion, the finger vasomotor tone was enhanced, especially in hypoxia (P = 0.01). Mild hypothermia aggravated finger vasoconstriction instigated by local cooling (P < 0.01), but the response did not differ between the two breathing conditions (P > 0.05). Hypoxia tended to attenuate the sensation of coldness (P = 0.10, r = 0.40) and thermal discomfort (P = 0.09, r = 0.46) in the immersed hand. Both in normoxia and hypoxia, the whole body thermal state dictates the cutaneous vasomotor reactivity to localized cold stimulus.
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  • 文章类型: Journal Article
    Pressure ulcers are a common occurrence of damage to skin. Severity ranges from slightly discoloured skin to full thickness tissue damage which can be fatal in some cases. Engineering effort, typically developing computational models had made significant progress in the understanding and demonstration of the formation mechanism of pressure ulcers with the aetiology of excessive stress; however, relatively limited attempts had been made to develop relevant models for pressure ulcers caused by ischemia. The aim of this article is to present evidence of a computational model developed to simulate ischemic pressure ulcer formation and demonstrate the established relationship between the computational data and the acquired clinically relevant experimental data by utilising Laser Doppler Velocimetry. The application of the presented computational model and the established relationship allows the evaluation of the effect of a mechanical loading to the cutaneous blood flow velocity which is a step closer to understand and evaluate a mechanical load to the formation of pressure ulcers caused by ischemia.
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  • 文章类型: Comparative Study
    Forearm cutaneous blood flux (CBF) measurement with post-occlusive reactive hyperemia (PORH) is uncomfortable and may not be devoid of risks. We aimed to investigate post-compression reactive hyperemia (PCRH) with a custom-made indenter that was designed to be easily used routinely by inexperienced observers.
    Medical students evaluated PCRH with 1- to 4-min pressure applications of 16 to 34 kPa and PORH with 3-min forearm cuff occlusion using laser speckle contrast imaging in 15 healthy volunteers. Participants were asked to quantify their discomfort with a visual analogue scale (VAS) of 10 cm. Total ischemia (ISCH) was quantified by the product of CBF during ischemia and ischemia duration (min). We subtracted the CBF changes in the skin from a reference ipsilateral (PCRH) or contralateral (PORH) non-stimulated area.
    The average VAS was 1.0 for PCRH vs. 6.0 for PORH (p < 0.001). A strong linear relationship between ISCH and peak PCRH (r2 = 0.915, p < 0.001) was noted. Peak PORH values (63.9 laser perfusion units (LPU)) were significantly lower than all values of the 3-min PCRH (72.6 LPU), including the one obtained with 16 kPa.
    Inexperienced observers could test microvascular reactivity with PCRH without inducing the discomfort that is typically experienced with PORH. Further, PCRH elicits a higher peak response to ischemia compared with PORH. This extremely simple method could influence a broad spectrum of routine cutaneous microcirculation investigations, especially when a painful approach is particularly inadequate or if the patient is fragile.
    NCT02861924.
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  • 文章类型: Journal Article
    Aim: Tea is usually consumed at two temperatures (as hot tea or as iced tea). However, the importance of drink temperature on the cardiovascular system and on metabolism has not been thoroughly investigated. The purpose of this study was to compare the cardiovascular, metabolic and cutaneous responses to the ingestion of caffeinated herbal tea (Yerba Mate) at cold or hot temperature in healthy young subjects. We hypothesized that ingestion of cold tea induces a higher increase in energy expenditure than hot tea without eliciting any negative effects on the cardiovascular system. Methods: Cardiovascular, metabolic and cutaneous responses were analyzed in 23 healthy subjects (12 men and 11 women) sitting comfortably during a 30-min baseline and 90 min following the ingestion of 500 mL of an unsweetened Yerba Mate tea ingested over 5 min either at cold (~3°C) or hot (~55°C) temperature, according to a randomized cross-over design. Results: Averaged over the 90 min post-drink ingestion and compared to hot tea, cold tea induced (1) a decrease in heart rate (cold tea: -5 ± 1 beats.min-1; hot tea: -1 ± 1 beats.min-1, p < 0.05), double product, skin blood flow and hand temperature and (2) an increase in baroreflex sensitivity, fat oxidation and energy expenditure (cold tea: +8.3%; hot tea: +3.7%, p < 0.05). Averaged over the 90 min post-drink ingestion, we observed no differences of tea temperature on cardiac output work and mean blood pressure responses. Conclusion: Ingestion of an unsweetened caffeinated herbal tea at cold temperature induced a greater stimulation of thermogenesis and fat oxidation than hot tea while decreasing cardiac load as suggested by the decrease in the double product. Further experiments are needed to evaluate the clinical impact of unsweetened caffeinated herbal tea at a cold temperature for weight control.
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  • 文章类型: Journal Article
    Aim: Acute ingestion of alcohol is often accompanied by cardiovascular dysregulation, malaise and even syncope. The full hemodynamic and cutaneous responses to the combination of alcohol and sugar (i.e., alcopops), a common combination in young people, and the mechanisms for the propensity to orthostatic intolerance are not well established. Thus, the purpose of this study was to evaluate the cardiovascular and cutaneous responses to alcopops in young subjects. Methods: Cardiovascular and cutaneous responses were assessed in 24 healthy young subjects (12 men, 12 women) sitting comfortably and during prolonged active standing with a 30-min baseline and 130 min following ingestion of 400 mL of either: water, water + 48 g sugar, water + vodka (1.28 mL.kg-1 of body weight, providing 0.4 g alcohol.kg-1), water + sugar + vodka, according to a randomized cross-over design. Results: Compared to alcohol alone, vodka + sugar induced a lower breath alcohol concentration (BrAC), blood pressure and total peripheral resistance (p < 0.05), a higher cardiac output and heart rate (p < 0.05) both in sitting position and during active standing. In sitting position vodka + sugar consumption also led to a greater increase in skin blood flow and hand temperature (p < 0.05) and a decrease in baroreflex sensitivity (p < 0.05). We observed similar results between men and women both in sitting position and during active standing. Conclusion: Despite lower BrAC, ingestion of alcopops induced acute vasodilation and hypotension in sitting position and an encroach of the hemodynamic reserve during active standing. Even if subjects did not feel any signs of syncope these results could be of clinical importance with higher doses of alcohol or if combined to other hypotensive challenges.
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  • 文章类型: Journal Article
    Unequivocal enhancement of cutaneous vasomotor function has yet to be demonstrated following heat acclimation, possibly because the adaptation stimulus was not sustained, or because thermoeffector function was not assessed at equivalent deep-body temperatures. Therefore, forearm and local cutaneous vascular conductances were evaluated during exercise eliciting matched deep-body temperatures (37.5 °C, 38.5 °C), before and after isothermal heat acclimation. Both indices increased (21% and 25%), confirming cutaneous vasomotor adaptation can occur, provided those experimental design specifications are satisfied.
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  • 文章类型: Journal Article
    BACKGROUND: We recently introduced a new rat model of emotional hyperthermia in which a salient stimulus activates brown adipose tissue (BAT) thermogenesis and tail artery constriction. Antipsychotic drugs, both classical and second generation, act to reduce excessive assignment of salience to objects and events in the external environment. The close association between salient occurrences and increases in body temperature suggests that antipsychotic drugs may also reduce emotional hyperthermia.
    OBJECTIVE: We determined whether chlorpromazine, clozapine, and risperidone dose dependently reduce emotionally elicited increases in BAT thermogenesis, cutaneous vasoconstriction, and body temperature in rats.
    METHODS: Rats, chronically instrumented for measurement of BAT and body temperature and tail artery blood flow, singly housed, were confronted with an intruder rat (confined within a small wire-mesh cage) after systemic pre-treatment of the resident rat with vehicle or antipsychotic agent. BAT and body temperatures, tail blood flow, and behavioral activity were continuously measured.
    RESULTS: Clozapine (30 μg-2 mg/kg), chlorpromazine (0.1-5 mg/kg), and risperidone (6.25 μg-1 mg/kg) robustly and dose-relatedly reduced intruder-elicited BAT thermogenesis and tail artery vasoconstriction, with consequent dose-related reduction in emotional hyperthermia.
    CONCLUSIONS: Chlorpromazine, a first-generation antipsychotic, as well as clozapine and risperidone, second-generation agents, dose-dependently reduce emotional hyperthermia. Dopamine D2 receptor antagonist properties of chlorpromazine do not contribute to thermoregulatory effects. Interactions with monoamine receptors are important, and these monoamine receptor interactions may also contribute to the therapeutic effects of all three antipsychotics. Thermoregulatory actions of putative antipsychotic agents may constitute a biological marker of their therapeutic properties.
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