The vasoactivity of lignocaine has an important influence on its clinical efficacy and systemic vascular absorption. The aim of this study was to evaluate its vasoactive properties when administered by the non-invasive technique of iontophoresis. We used laser Doppler imaging to measure the forearm skin blood flow responses of seven ...

Plethsymographic recordings are used to evaluate changes in peripheral vascular tonus. Twenty-six volunteers (15 men, 11 women) with a mean age 31 years were included in this study. Plethsymographic recordings were done both at baseline and +40C temperatures bilaterally. Significant reductions in systemic blood flow were noted with different maneuvers. ...

Interstitial fluid pressure (P(if)) is a key determinant in increasing the transcapillary driving pressure, pulling fluid from the microcirculation into the interstitial space at the onset of acute inflammatory reactions and the oedema formation associated with these. Prostaglandin E1 (PGE1) induces lowering of P(if) in rat skin which increases transcapillary ...

INTRODUCTION: In cutaneous lymphocytic inflammation, enhanced regional blood flow is suggested by persistent erythema and warmth. Direct assessment of the microcirculation, however, has been limited by tissue edema and skin thickness. METHODS: To assess the microcirculatory adaptations to the epicutaneous antigen oxazolone, we studied the first pass kinetics and microvascular ...

Though the skin permeation enhancement effect of chemical penetration enhancers has been studied extensively, their skin irritation potential has not been adequately investigated. The objective of this study was to evaluate the skin permeation enhancement effect and skin irritation of saturated fatty alcohols using melatonin as a model compound. A ...

The contribution of benzene to body burden after skin absorption compared with that due to inhalation absorption is of potential interest in the setting and interpretation of benzene (inhalation) exposure standards. However, an understanding of the quantitative relationship between skin and inhalation absorption, under different exposure conditions, is required. Such ...

The relative magnitude of endothelial versus non-endothelial vasodilatation in the skin of limbs of patients with peripheral arterial occlusive disease (PAOD) is not known. We therefore investigated the effects of iontophoretically administered sodium nitroprusside (SNP) and acetylcholine (Ach) on the skin microvascular blood flow measured by laser-Doppler fluxmetry. METHODS: Blood ...

Animal generated water movements are visualized and quantified using two-dimensional particle image velocimetry (PIV). The resulting vector flow fields allow for the study of the distribution of velocity, vorticity and vortices. Structural and temporal aspects of animal-induced flows covering a range of Reynolds (Re) numbers between less than 1 to ...

PURPOSE: Pressure-driven jets have been used for intradermal delivery of a variety of drugs. Despite their introduction into clinical medicine, variability and occasional bruising have limited their widespread acceptance. Although numerous clinical studies of jet injectors have been reported in the literature, surprisingly little is known about the mechanisms of ...

Experiments on rats with hereditary stress-induced arterial hypertension showed that hypertension shortened the latency and increased the amplitude of constrictive reaction of skin blood vessels to rapid cooling characterized by more rapid and considerable increase in blood norepinephrine content compared to slow cooling. Decreased thermal threshold of metabolic reaction suggests ...

The blood supply to the skin is provided by a network of arterioles, capillaries and venules organized into a superficial and a deep plexus. The assessment of skin microcirculation is of valuable interest in cosmetology in the quantification of the sun protection factor, skin irritation and efficacy of antiredness treatments. ...

The dorsal fin of the bottlenose dolphin Tursiops truncatus contains blood vessels that function either to conserve or to dissipate body heat. Prior studies have demonstrated that heat flux, measured from a single position on the dorsal fin, decreases during body cooling and diving bradycardia and increases after exercise and ...

This paper deals with experimental modeling of the unsteady junction flow features in the vicinity of an isoflux heated wall with mounted insulated rectangular ribs representing three distinctive ribbed test geometries. Both flow visualizations and surface temperature distributions show that the blockage effect upstream of the ribs, as well as ...

Infrared (IR) thermography, because of its two-dimensional and non-intrusive nature, can be exploited in industrial applications as well as in research. This paper deals with measurement of convective heat transfer coefficients (h) in three complex fluid flow configurations that concern the main aspects of both internal and external cooling of ...

During the past two decades we have performed pool boiling experiments under microgravity conditions with saturated and subcooled liquids using various fluids, mostly fluorinated hydrocarbons, and various shapes of heaters. The common observation at subcooled boiling is the development of thermocapillary convection around bubbles. This convection forms jet streams above ...

BACKGROUND: An increased cardiovascular risk and mortality in hypopituitary patients receiving conventional hormonal treatment without GH replacement have been shown in several studies. Various atherogenic risk factors including endothelial dysfunction - an early event in the atherogenesis - are more expressed in adults with GH-deficiency (GHD). Changes in microcirculation and ...

The heat-acclimated rock pigeon is thought to use cutaneous water evaporation (CWE) as the 'preferred' route for heat dissipation, and this mechanism is controlled by adrenergic signaling. In the present study, we tested the hypothesis that adjustments in skin blood flow are a crucial component of this adaptation. Skin blood ...

We compared the results of skin blood flow (SBF) measurements, obtained simultaneously in adjacent fingertips by laser Doppler flowmetry (LDF) and thermal clearance (TC) probes, having approximately the same spatial and temporal characteristics. Experiments were performed in nine healthy volunteers during rest at room temperature (26-28 degrees C). A time ...

OBJECTIVES: To use the technique of dermal microdialysis to examine sensitivity of skin vessels to noradrenaline (NA) in patients with familial dysautonomia (FD) and in healthy controls. METHODS: In 14 patients with FD and 12 healthy controls, plasma extravasation, local laser Doppler blood flow, and skin blanching were observed before, ...

OBJECTIVE: to evaluate immunotherapy as a means of improving peripheral blood flow in chronic leprosy patients. DESIGN: this was a double-blind, randomised, placebo-controlled, clinical trial. MATERIALS: heat-killed Mycobacterium vaccae 1mg plus 0.02 microg Tuberculin protein per 0.1 ml dose in borate buffer, with saline as placebo. Those studied were 92 ...

BACKGROUND: Although the microvascular blood flow response to wounding is predominantly vasodilation at skin sites with nutritive capillary perfusion (NUTR), there is a significant vasoconstrictive response at sites with high arteriovenous perfusion (AV). There may be a difference between NUTR and AV sites in the vasoactive factors which mediate the ...

BACKGROUND: Quantifying sympathetic activity is difficult. Direct measurement is possible and superior to indirect techniques, but nerves to internal organs are not accessible in humans. Recently, we validated a quantitative technique for measurement of cutaneous blood flow using heat as an indicator. The aim of the study was to investigate ...

In the present study, we examined the effect of thermal stress on the magnitude and pattern of change in leg volume during orthostatic stress and thigh occlusion in humans. Ten healthy volunteers underwent whole-body thermal stress produced by a cool- or hot-water-perfused suit and local heat stress of the calf. ...

BACKGROUND: The combination of laser Doppler flowmetry and non-invasive blood pressure monitoring allows the continuous observation of cutaneous vascular resistance (CVR). Continuous recording of unmodulated skin blood flow (SBF) is very sensitive to artefacts, rendering the method unreliable. In contrast, intermittent short lasting challenges of the CVR by cardiovascular autonomic ...

BACKGROUND: We aimed to study if brief compression (20 s) of the brachial artery could provoke a hyperaemic response in forearm skin. In addition, we studied the effect of pre-dilating the skin vessels with locally iontophoresed sodium nitroprusside on the hyperaemic response. METHODS: Ten healthy male volunteers were studied. A ...

The aim of this study was to investigate the impact of changes in local blood flow on the recovery of a small, diffusible molecule (sodium fluorescein) from the extravascular tissue space of the skin, by microdialysis in vivo. Loss and recovery of fluorescein by linear microdialysis probes (5-kDa molecular mass ...

The strength of sympathetic vasoconstrictor nerve traffic to the skin has an important role in human thermoregulation since it controls heat loss from the skin by constricting or dilating cutaneous blood vessels. This study sought to clarify the time relationship between a reduction of the vasoconstrictor activity induced by elevating ...

Orthostatic tolerance is reduced in the heat-stressed human. The purpose of this project was to identify whether skin-surface cooling improves orthostatic tolerance. Nine subjects were exposed to 10 min of 60 degrees head-up tilting in each of four conditions: normothermia (NT-tilt), heat stress (HT-tilt), normothermia plus skin-surface cooling 1 min ...

Mild hypothermia (33-36 degrees C) might be beneficial when induced during or after insults to the brain (cardiac arrest, brain trauma, stroke), spinal cord (trauma), heart (acute myocardial infarction), or viscera (hemorrhagic shock). Reaching the target temperature rapidly in patients inside and outside hospitals remains a challenge. This study was ...

Jet A and JP-8 are the major jet fuels used in civilian and military (US Air Force) flights, respectively. JP-8+100 is a new jet fuel recently introduced by US Air Force in some of its locations. The purpose of this study was to investigate the effects of dermal exposure of ...

We examined the effects of repeated artificial CO(2) (1,000 ppm) bathing on tympanic temperature (T(ty)), cutaneous blood flow, and thermal sensation in six healthy males. Each subject was immersed in CO(2)-rich water at a temperature of 34 degrees C up to the level of the diaphragm for 20 min. The ...

The thermally stimulated discharge (TSD) method, intended for the analysis of charged dielectrics, was used for human blood research. Above-room-temperature TSD spectra of blood consist of three peaks. There are indications that the low-temperature peak (40-50 degrees C) corresponds to the thermally stimulated destruction of hydrate shells surrounding blood components ...

Pressure ulcers occur over the sacrum but are rare over the gluteus maximus. This predilection is partly explained by pressure concentration effects, but other factors may be involved. The authors hypothesized that if resting sacral skin blood flow was greater than in surrounding tissues, a decrease or stoppage of blood ...

In rats, a significant portion of total body heat loss occurs through sympathetically mediated changes in tail blood flow, making the rat tail a convenient model to study vasomotor activity during thermoregulation. Our aim was to perform a non-invasive study of the mechanisms of blood vessel control in the rat ...

OBJECTIVE AND DESIGN: The aim of the present study was to examine the contribution of the two kinin receptors B1 and B2 to the increased blood flow observed in response to bradykinin (BK) in a blister model under different injury conditions. MATERIAL: Young male Sprague-Dawley rats weighing 250-350 g were ...

It has been proposed that insulin-mediated changes in muscle perfusion modulate insulin-mediated glucose uptake. However, the putative effects of insulin on the microcirculation that permit such modulation have not been studied in humans. We examined the effects of systemic hyperinsulinemia on skin microvascular function in eight healthy nondiabetic subjects. In ...

The aims of this study were to quantify the changes in finger pulp skin temperature, laser Doppler flow (LDF, microvascular flux) and photoplethysmogram (PPG, microvascular blood volume pulsatility), induced by a deep inspiration in healthy subjects, and to investigate the repeatability of these responses within a measurement session and between ...

BACKGROUND/AIMS: The L*a*b* coordinate is the most commonly used colour system to measure skin colour in dermatology and cosmetology. In this system, a* and L* are often used for quantification of the degrees of erythema and pigmentation. The aim of this study was to examine whether a* and L* can ...

The mechanism of action of topical silicone gel sheets on hypertrophic scars is not well understood and their effect on the blood flow within hypertrophic scars has not been investigated. The purpose of this study was to examine whether application of silicone gel sheets produced any acute effects on blood ...

Shaanxi Province located at Midwest inland of China was a typical iodine deficient disorders region. To investigate iodine and selenium levels of neonates in the Shaanxi sub-clinical cretinism region of China after supplement of iodine salt for nearly twenty years. We collected 56 umbilical cord blood samples from cretinous regions ...

The extractability of hordeins from barley grains was investigated after wet and dry heating conditions. It was found that the amount of hordeins extractable with 55% 2-propanol decreased in a time-dependent manner after barley grains were steamed (wet heating), whereas hordeins showed no effect from heating in an oven at ...

Key factors and practical limits of blood extraction from lancet wounds on body sites other than the finger were determined by testing a large number of conditions. During these tests, the pain associated with lancing alternate body sites was rated as less painful than a fingerstick 98% of the time. ...

Impaired blood flow to skin contributes to foot ulceration and amputation. The overall objective of this cross-sectional study was to examine the relationship between chronic physical activity and skin blood flow in Type 2 diabetes. To do so, diabetic and control subjects were separated into four groups based on a ...

Blood flow to the skin is controlled by body temperatures in two ways: core and mean skin temperature combine in the central nervous system to form a reflex mechanism that controls the frequency of activity in sympathetic nerves to the cutaneous blood vessels; and local mechanisms independent of reflex effects ...

We examined adrenergic controlled cutaneous blood flow and temperature regulation in Prader-Willi syndrome. A body mass index was calculated for each participant. Thermal and laser Doppler finger probes were applied for continuous simultaneous surface temperature and capillary blood flow recording. Analysis with respect to group, age, body mass index, and ...

BACKGROUND/AIMS: Vasodilation with increased cutaneous perfusion is an essential part of an irritant inflammatory response. The aim of the present study was to investigate the usefulness of the high-resolution laser Doppler perfusion imaging (HR-LDPI) technique for investigating irritant skin reactions. Irritants may elicit clinically different reactions due to different skin ...

BACKGROUND/AIMS: High resolution laser Doppler perfusion imaging (HR-LDPI) is a non-touch method used for mapping cutaneous microcirculation. The aim of the present study was to investigate the usefulness of this technique for studies of cutaneous blood flow of normal untreated forearm skin and for the assessment of weak irritant reactions ...

The venoarteriolar response causes vasoconstriction to skin and muscle via local mechanisms secondary to venous congestion. The purpose of this project was to investigate whether this response occurs through alpha-adrenergic mechanisms. In supine individuals, forearm skin blood flow was monitored via laser-Doppler flowmetry over sites following local administration of terazosin ...

A series of experimental trials on methods of treatment and prevention of shimao zheng (fleece-eating) were carried out using various sulphates. The results confirmed the hypothesis that this is a local nutritional and metabolic disease, caused mainly by a sulphur deficiency, that could be prevented or cured with supplementary sulphur ...

OBJECTIVE: To determine what effect transcutaneous electric nerve stimulation (TENS) intensity has on local and distal cutaneous blood flow and skin temperature. DESIGN: Double-blind conditions. SETTING: University research laboratory. PARTICIPANTS: Forty subjects (20 men, 20 women) randomly assigned to 1 of 4 groups (10 per group): control, above-motor-threshold TENS, below-motor-threshold ...