首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
Abstract Many clinical studies have shown that low humidity has a deleterious effect on skin, but the mechanisms involved are poorly understood. To clarify the changes that occur in skin, we examined epidermal cell proliferation in mice kept in a dry (relative humidity < 10%) or a moist (relative humidity > 90%) environment. In animals exposed to low humidity, epidermal DNA synthesis started to increase within 12 h, reaching twice the original level, and the increased level was maintained for up to 5 days. The transepidermal water loss (TEWL) of mice kept for 12 h in the dry environment was the same as that of mice kept in the moist enviroment, but the skin conductance was lower. The increase in epidermal DNA synthesis following exposure to the dry environment was inhibited by topical application of petrolatum. It is concluded that loss of water from the stratum corneum induces epidermal cell proliferation within 12 h, and this change occurs in the absence of apparent cutaneous barrier dysfunction. Received: 20 April 1998 / Received after revision: 2 July 1998 / Accepted: 31 July 1998  相似文献   

2.
The primary purpose of this feasibility study was to establish a correlation between pro-inflammatory cytokine accumulation and severity of tissue damage during local pressure with various temperatures. The secondary purpose was to compare skin blood flow patterns for assessing the efficacy of local cooling on reducing skin ischemia under surface pressure. Eight Sprague–Dawley rats were assigned to two protocols, including pressure with local cooling (Δt = −10 °C) and pressure with local heating (Δt = 10 °C). Pressure of 700 mmHg was applied to the right trochanter area of rats for 3 h. Skin perfusion quantified by laser Doppler flowmetry and TNF-1 and IL-1β levels were measured. Our results showed that TNF-α concentrations were increased more significantly with local heating than with local cooling under pressure whereas IL-1β did not change. Our results support the notion that weight bearing soft tissue damage may be reduced through temperature modulation and that non-invasive perfusion measurements using laser Doppler flowmetry may be capable of assessing viability. Furthermore, these results show that perfusion response to loading pressure may be correlated with changes in local pro-inflammatory cytokines. These relationships may be relevant for the development of cooling technologies for reducing risk of pressure ulcers.  相似文献   

3.
Topical betamethasone-17-valerate inhibits the vasodilatation response to local non-pathological heating of rat skin.1 We have shown that this effect can also be demonstrated in man. Topical betamethasone-17-valerate significantly inhibited the increase in human forearm cutaneous blood flow in response to heat of 44°C, as measured by laser-Doppler velocimetry. This suggests that the effects of topical steroids upon skin blood flow in the rat and in man are similar, and supports the use of the animal model as a paradigm for studying human skin blood flow, and changes in response to anti-inflammatory steroids.  相似文献   

4.
The effect of moist and dry conditions on the process of angiogenesis during dermal repair was investigated. The moist conditions were achieved by covering excised wounds on porcine flank skin with the adhesive polyurethane dressing Opsite and dry conditions were achieved by exposure to air through dry gauze dressings. Angiogenesis was assessed during the period from 3 to 60 d after injury. Quantitative studies, using computerized image analysis, were carried out on microfocal x-ray images of skin sections whose blood system had been perfused in vivo with a radio-opaque medium. The analytical technique yielded information with regard to vessel number per wound and also the area occupied by blood vessels per unit wound area. Three regions were assessed in each wound bed: upper zone, just below the surface of the wound; the lower zone, just above the base of the wound bed; and the middle zone, midway between the other two zones. The results showed that the wounds maintained in a moist environment revascularized at a greater rate than those maintained in a dry environment. This was apparent in all of the zones of the wound bed examined. The development of new vessels occurred in a more orderly manner in the moist wounds. There was an early increase in vessel number rising to a peak around days 3-5, then a gradual decrease in number starting around day 7. In contrast, in the dry wounds the development of blood vessels was less rapid. Peak vessel number in the upper zone was significantly less than that achieved in the moist wounds, and was not reached until 7 d after injury. The decrease in vessel number from the peak was less rapid in the dry wounds, suggesting that there was a delayed entry into the remodeling phase in comparison with the moist wounds. The results also showed that the total percentage area of the wound bed occupied by blood vessels was greater in the moist wounds than the dry wounds from 3 d after injury until day 7. This level of vascularization was maintained beyond 7 d after injury even when the vessel number in the moist wounds was significantly less than in the dry wounds, suggesting that the vessels in the moist wounds were larger and, presumably, more mature. In general, moist wounds showed a more rapid decline towards uninjured skin levels of vascularization than dry wounds.  相似文献   

5.
AimProlonged mechanical loading on soft tissues adjacent to bony prominences can lead to pressure ulcers. The presence of moisture at the skin interface will lower the tolerance to load. Absorbent pads manage moisture in individuals with incontinence, although their role in maintaining skin health is unknown. The present study investigated the effects of moist incontinence pads on skin physiology after periods of mechanical loading.Material and methodsTwelve healthy participants were recruited to evaluate a single incontinence pad design under three moisture conditions: 0% (dry), 50% and 100% fluid capacity. For each pad condition, pressure (9 kPa) or pressure in combination with shear (3 N) was applied to the sacrum, followed by a period of off-loading. Measures included trans-epidermal water loss (TEWL) and inflammatory biomarkers sampled at the skin interface.ResultsResults revealed no change in TEWL in the loaded dry pad condition. By contrast, when the pads contained moisture, significant increases in TEWL were observed. These increases were reversed during off-loading. Inflammatory biomarkers, specifically IL-1α/total protein ratio, were up-regulated during dry pad loading, which recovered during off-loading. Loaded moist pads caused a significant increase in biomarkers, which remained elevated throughout the test period.ConclusionThe study revealed a marked compromise to stratum corneum integrity when the skin was exposed to moist incontinence pads in combination with mechanical loads. These physiological changes were largely reversed during off-loading. Incontinence pads provided some protection in the dry state, although more research is required to determine optimal clinical guidance for their use.  相似文献   

6.
Mechanically induced itch is an important cofactor in many patients with chronic itch. However, studying mechanical itch in a controlled environment is challenging because it is difficult to evoke. We investigated the use of whole body vibration (WBV) exercise, a training method used for musculoskeletal rehabilitation, to experimentally evoke mechanical itch. Mild to severe itch ascending from the soles to the groins was evoked in 16 of 20 healthy participants. We observed a characteristic on/off itch crescendo pattern reflecting the alternating intervals of vibration and no vibration. Wheals or an angioedema was absent, and serum mast cell tryptase was not increased by the exercise. Participants described the evoked sensation primarily as “itching” with some nociceptive components. Itch intensity correlated with the intensity of a concomitant erythema (R = 0.45, P = 0.043) and with the rise in skin temperature (R = 0.54, P = 0.017). Hence, WBV can be used as an easily applicable, noninvasive, investigator‐ and user‐friendly framework for studying mechanical itch. Moreover, WBV allows to “switch itch on and off” rapidly and to simultaneously study interactions between itch, skin blood flow and skin temperature.  相似文献   

7.
Daily oral intake of 40 μg Aloe sterol was shown in a double-blind clinical trial to significantly increase skin barrier function, moisture and elasticity. Ultrasonographic results also suggested that the intake of Aloe sterol increases collagen content in the dermis. Here, we evaluate the effects of a much smaller dose of Aloe sterol, approximately half that used previously, on skin functions in more detail. This is a monocentric, double-blind, randomized, placebo-controlled, supplementation study of the effects of low-dose Aloe sterol on skin transepidermal water loss, hydration, collagen score, evaluation of objective or subjective symptoms, and safety after 12 weeks of daily intake. We randomly administrated either Aloe sterol or placebo to 122 healthy volunteers. Transepidermal water loss was significantly reduced and collagen score was increased in the Aloe sterol group compared with the placebo group at week 12. In the Aloe sterol group, there was significant improvement of objective skin condition (face erythema and pruritus of inner and outer arms) at week 12 compared with week 0, but not in the placebo group. Subjectively, there was significant improvement of visual analog scale of skin acne, fingernail brittleness and constipation in the Aloe sterol group. According to subgroup analysis, although not planned before the study initiation, subjects with dry skin in the Aloe sterol group had significantly increased skin hydration values at week 12 compared with the placebo group. Our results confirmed that even low-dose Aloe sterol ingestion improves skin moisture by promoting skin barrier function and dermal collagen production, which contributes to maintenance of healthy skin.  相似文献   

8.
Background/aims: Changes in the skin conditions after exposure to low humidity have been generally experienced in everyday life, but there have been few reports to approach it—especially in healthy skin. We have examined the effect of low humidity on healthy human skin by using noninvasive measurement devices. Methods: Skin conditions on the ventral forearm and the cheek before and after 3 or 6 h exposure to low humidity were evaluated by measuring skin surface conductance, skin surface capacitance and transepidermal water loss. Skin surface replicas were also taken before and after exposure and analysed for roughness parameters—Ra (arithmetic mean roughness value), Rz (10-point height), Sm (mean value of the profile element) and VC1 (anisotropy of skin furrows). Results: There was a significant decrease of water content of stratum corneum at both test sites from the time points 0 h to 3 h and 6 h (P < 0.01) and transepidermal water loss from the time point 0 h to 6 h (P < 0.05). Regarding the roughness parameters, a significant increase of Rz in the directions of 45°/225° and 90°/270° to the body axis and Sm in the directions of 0°/180° (P < 0.05) on the forearm and VC1 (P < 0.05) on the cheek. The parameter Rz also showed a tendency to increase in the directions of 45°/225° (P = 0.06) on the cheek. A specific pattern of the changes to be related to the Langer's lines in the surface morphology was observed. The changes of skin surface pattern in our experiment lead us to consider that exposure to low humidity even in such a short period would be related to inducing aggravation of skin texture and the formation of fine wrinkles. Conclusion: A short exposure of skin to a low-humidity environment induced changes in the moisture contents in the stratum corneum and skin surface pattern, which lead us to assume that a dry environment in our daily life would make fine wrinkles related to lack of water in the stratum corneum.  相似文献   

9.
The neuropeptides CGRP (calcitonin gene‐elated peptide) and substance P (SP) mediate neurogenic inflammation. Both are degraded by the neutral endopeptidase (NEP) which can be blocked by phosphoramidon. The aim was to evaluate the effect of NEP inhibition on sweating and vasodilatation. Dermal microdialysis was performed on the skin of 39 subjects. Two fibres were perfused with phosphoramidon (0.01%, 0.02% or 0.2%), two with saline. Acetylcholine (ACh) was either added to the microdialysis perfusate (n = 30, 10−2 m ) or thermoregulatory sweating was induced (n = 9). Co‐application of phosphoramidon reduced cholinergic and thermoregulatory sweating. However, the flare size – a localized increase in superficial blood flow after ACh‐application – was significantly increased. The increase in flare size is most probably due to increased CGRP levels. The inhibition of sweating by phosphoramidon may involve an increase in SP, a reduction in CGRP‐degradation fragments or a direct inhibitory action of phosphoramidon.  相似文献   

10.
The aim of this study was to assess the effect of thermal stimuli or distal scratching on skin blood flow and histamine-induced itch in healthy volunteers. Twenty-one healthy volunteers participated in the study. Baseline measurements of skin blood flow were obtained on the flexor aspect of the forearm. These measurements were compared with skin blood flow after various stimuli: heating the skin, cooling the skin, noxious cold 2 degrees C, noxious heat 49 degrees C, and scratching via a brush with controlled pressure. Afterwards histamine iontophoresis was performed and skin blood flow and itch intensity were measured immediately after the above-mentioned stimuli. Scratching reduced mean histamine-induced skin blood flow and itch intensity. Noxious heat pain increased basal skin blood flow but reduced histamine-induced maximal skin blood flow and itch intensity. Cold pain and cooling reduced itch intensity, but neither affected histamine-induced skin blood flow. Sub-noxious warming the skin did not affect the skin blood flow or itch intensity. These findings suggest that heat pain and scratching may inhibit itch through a neurogenic mechanism that also affects skin blood flow.  相似文献   

11.
Background  Emollient molecules are widely used in skin care formulations to improve skin sensory properties and to alleviate dry skin but little is understood regarding their effects on skin biomechanical properties. Objectives  To investigate the effects of emollient molecules on drying stresses in human stratum corneum (SC) and how these stresses are related to SC components and moisture content. Methods  The substrate curvature method was used to measure the drying stresses in isolated SC following exposure to selected emollient molecules. While SC stresses measured using this method have the same biaxial in vivo stress state and moisture exchange with the environment, a limitation of the method is that moisture cannot be replenished by the underlying skin layers. This provides an opportunity to study the direct effects of emollient treatments on the moisture content and the components of the SC. Attenuated total reflectance Fourier transform infrared spectroscopy was used to determine the effects of emollient molecules on SC lipid extraction and conformation. Results  Emollient molecules resulted in a complex SC drying stress profile where stresses increased rapidly to peak values and then gradually decreased to significantly lower values compared with the control. The partially occlusive treatments also penetrated into the SC where they caused extraction and changes in lipid conformation. These effects together with their effects on SC moisture content are used to rationalize the drying stress profiles. Conclusions  Emollient molecules have dramatic effects on SC drying stresses that are related to their effects on intercellular lipids and SC moisture content.  相似文献   

12.

Background

Different strategies for hand skin hygiene have been used to prevent the spread of SARS-CoV-2. However, frequent hand sanitization has been associated with skin damage. The present study aimed to evaluate hand hygiene habits during the COVID-19 pandemic and the effect of the repetitive use of soap or alcohol-based products on skin characteristics.

Methods

We conducted a survey regards hand hygiene habits acquired during the COVID-19 pandemic. Also, we performed cutometry in a cohort of individuals who cleansed their volar forearms every 30 min, during 4 h, using soap or alcohol-based products.

Results

We received 138 responses from people with medium-high educational level who reported a 2.5-time increase in the frequency of hand cleansing (p < 0.0001) that resulted in skin damage. An in vivo analysis of skin moisture and elasticity was also performed among 19 health workers and students. In general, skin moisture decreased with every cleansing, mainly after 2 h of washing with soap (p < 0.01), while skin elasticity only reduced after 4 h of treatment (p < 0.05). Alcohol-based solution or alcohol-based gel (70% ethanol, both) did not affect skin moisture or elasticity during testing.

Conclusion

It is known that the excessive use of soap or alcohol-based products causes dermatological issues. The present study demonstrates that non-medicated soap significantly affects skin moisture and elasticity, probably because the soap removes the hydrolipidic protective barrier, favoring transepidermal water loss, where the lack of the appropriate stratum corneum hydration also affects skin elasticity, mainly associated with changes in epidermal structure.  相似文献   

13.
Background The scalp is commonly associated with itch and burning sensations. Previous studies have shown the scalp is highly innervated compared with other body areas. However, limited data are available on sensory testing associated with C nerve fibres of the healthy scalp. Objective To examine the function of C nerve fibre‐mediated sensations such as warmth, heat pain, itch and neurogenic inflammation in two areas of the scalp (crown and occiput) in comparison to forearm skin. Methods Twenty‐two healthy subjects (11 women, 11 men) underwent quantitative computerized thermosensory testing to assess warmth and heat pain thresholds. Itch was induced using histamine iontophoresis and application of cowhage spicules, and the intensity of each itch was assessed. Skin blood flow was measured at baseline and after each itch induction to assess degree of neurogenic inflammation. Results A majority (64%) of the crown warmth threshold measurements exceeded 50 °C while all 22 forearm warmth thresholds measurements were significantly lower than 50 °C. Both scalp sites had significantly higher warmth and heat pain thresholds compared with the forearm (P < 0·001). Itch ratings of histamine and cowhage on both scalp sites were significantly lower than on the forearm (P 0·001). Histamine and cowhage induced an increase in skin blood flow from baseline on the forearm compared with the scalp (P < 0·001). Conclusions This study demonstrates a significant insensitivity of C nerve fibres of the scalp to warmth, heat pain, itch and neurogenic inflammation. These results suggest that the scalp has an aberrant response of C nerve fibres.  相似文献   

14.
Background: The well‐known characteristics of aging skin are the development of fine lines and wrinkles, but changes in skin tone, skin texture, thickness and moisture content are also aspects of aging. Rejuvenation of the skin aims at reversing the signs of aging and can be established in the epidermis as well as in the dermis. Aged dermis, in fact, has a degenerated collagen matrix. To regenerate this matrix, fibroblasts need to be stimulated into synthesizing new collagen. Aims: In this study, the effects of heat shocks of different temperatures on human dermal fibroblasts in ex vivo skin on the expression of procollagen 1, procollagen 3, heat shock protein (hsp)27, hsp47, and hsp70 are investigated. Materials and methods: The heat shocks were applied on ex vivo skin samples by immersing the samples in heated phosphate‐buffered saline of 45 °C or 60 °C. Metabolic activity was measured and at similar time points propidium–iodide–calceine staining was performed to establish cell viability. Quantitative polymerase chain reaction (qPCR) was performed after the heat shock to determine gene expression levels relative to the reference temperature. Furthermore, PicroSirius Red and hematoxylin stainings were performed to visualize the collagen network and the cells. Results: The skin samples were shown to be viable and metabolically active. Histology indicated that the heat shocks did not influence the structure of the collagen network or cell appearance. qPCR results showed that in contrast to the 45 °C heat shock the 60 °C heat shock resulted in significant upregulations of procollagen type I and III, hsp70 and hsp47. Conclusion: A 60 °C, heat shock stimulates the human dermal fibroblasts in ex vivo skin to upregulate their procollagen type I and type III expression.  相似文献   

15.
Background/aims: In physiotherapy, fango (mud) application is a frequently used heat therapy. The main therapeutic effects are due to the elevated temperature of the different tissues with a significant redistribution of blood towards the heated area. This may influence several cardiovascular parameters. There is only limited information on the effect of fango application on skin characteristics. It was the aim of the present study to evaluate the effects of fango application on skin temperature, perfusion of the microcirculation and skin colour. At the same time, cardiovascular parameters such as heart rate, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded. Method: Eighteen healthy subjects (age 23.7±3.8 years) entered the study. The skin characteristics and cardiovascular parameters were measured before, during and after a 21‐min fango application at 44.5°C. Results: Skin temperature and perfusion of the microcirculation increased significantly during fango application: from 35.5±0.4°C to 44.3±1.2°C for skin temperature and from 23.2±8.8 to 197±41 p.u. for the skin microcirculation. These two parameters remained elevated during the fango application and decreased slowly to baseline values within 21 min after fango removal. Skin colour (CIELAB, a* parameter) increased from 11.0±2.5 to 17.9±1.9 when comparing pre‐ with post‐treatment values. At the end of the measuring period, the a* parameter did not return to baseline values (15.8±2.1). Heart rate increased with 8 bpm during the fango therapy and returned to baseline within 3 min after removal of the fango. SBP and DBP varied slightly during the fango application. They returned to baseline values within 21 min after fango removal. Conclusion: The skin parameters indicate a transient temperature effect with an increased perfusion of the microcirculation and a flooding of the superficial capacitance system. The cardiovascular parameters were only slightly influenced and remained in the physiological range. Fango application seems not to be too demanding for the cardiovascular system in healthy subjects.  相似文献   

16.
Summary The sweat gland function in atopic dermatitis (AD) and in respiratory atopy is a matter of controversy. We examined the baseline water loss and local sweating response in non-eczematous back skin of 146 young men: pure AD, AD with rhinitis/asthma, rhinitis/asthma alone, non-atopic dermatosis and non-atopic healthy. All AD subjects were further divided into the subgroups AD dry and AD normal skin. Following injections of saline and a high concentration of methacholine (5×104 mol/1) into separate sites the moisture losses were collected into closed pads over a period of 40 min. The baseline water loss was significantly increased (P<0.001) and median pure sweat loss was significantly decreased (P<0.01) in AD compared with nonatopic healthy individuals. These trends were accentuated in AD dry skin. Respiratory symptoms had no appreciable influence on results. A depressed sweating response occurred in 30% of AD subjects and 9% of non-AD subjects. An elevated baseline water loss value and a depressed sweat loss value coexisted in 22% of subjects with AD dry skin compared with 3% of the non-atopics.  相似文献   

17.
Our interest was to quantify the role of sweat gland activation on the maintenance of skin temperature during mild exercise in the heat. Seven days of tap-water iontophoresis decreased the number of active sweat glands by 72% which significantly increased forearm skin temperature and blood flow during mild exercise (70 W) in the heat (32 degrees C). Skin temperature of the treated forearm was 0.5 degrees C warmer (P=0.049); skin blood flow in the treated forearm was 13% higher than the control arm (P=0.021). These results illustrate the importance of sweat evaporation on skin temperature and blood flow during exercise.  相似文献   

18.
People with spinal cord injuries are at high risk for developing pressure ulcers. Increased skin temperature is one of the extrinsic causative factors for this multi-factorial disease. Previous animal studies revealed that local skin cooling reduced the severity of ulceration, and cooling is widely used in plastic surgery and organ transplants for tissue preservation. The objectives of this pilot study were to develop test protocols and instrumentation and to investigate the effect of local cooling on skin perfusion response to pressure on young healthy human subjects. Reactive hyperemia was quantified in this study to compare the effects of pressure with and without cooling. Reactive hyperemia is a normal physiological response occurring after vessel occlusion. Laser Doppler flowmetry was used to measure skin blood flow. Time-dependent spectral analysis was used to analyze and decompose the blood flow data into frequency ranges associated with specific blood flow control mechanisms. The study used a repeated measures design with two test conditions: 8 kPa of pressure with and without cooling to 25 °C. We hypothesized that local cooling would reduce the post-ischemic reactive hyperemic response induced by the rigid indenter. Time series results showed that normalized peak perfusion response was significantly lower with cooling (p = 0.019). Time-dependent spectral analysis results suggested that both metabolic and myogenic responses contribute to this protective effect. Findings from our study on humans were consistent with previous animal studies. Additional studies on individuals with spinal cord injury are planned to further evaluate the cooling effect in a high-risk population.  相似文献   

19.
Summary Thermography is a very instructive method of showing the interaction between direct changes in heat radiation of the surface of the skin and its relation to reflex processes. Short reflex arcs, such as the axon reflex, and long reflex arcs, such as the flush phenomenon provoked by visceral cutaneous reflexes, can be illustrated by thermography. Reflex changes in skin temperature by cooling the skin of patients with cold contact urticaria with the short-term development of large areas of warmed skin and also reflex changes in cholinergic urticaria after prior heating of such skin areas where the urticarial eruption follows are reflected in the picture of telethermography. Reflex arcs between extremities affect the arterial blood flow and show individual variation, as in the case of the cessation of permanent local vasoconstriction by indirect cooling. The thermographic illustration of convective heat transport to the skin surface can be obstructed by the cooling effect of sweat secretion, e.g., water vapor exudation and by changes in conductive heat transport in abnormal skin.  相似文献   

20.
ObjectivesThis study aimed to validate the skin temperature on sacral region and vascular attributes as early warning signs of pressure injury.MethodsTotally 415 patients admitted to the adult intensive care unit from August 2018 to April 2019 were prospectively screened. Daily blood pressure and blood glucose affecting vascular attributes and the relative skin temperature of sacral region were measured for 10 consecutive days. Collect the changes of these indicators during the occurrence of pressure injury. The optimal cut-off values of indicators were determined by X-tile analysis. The risk ratios of indicators associated with pressure injury were compared using the Cox proportional hazards regression model.ResultsThere were no obvious interactions among blood pressure, blood glucose and relative skin temperature (P > 0.05). The optimal cutoff value for above indicators was 63.5 mmHg, 9.9 mmol/L and −0.1 °C, respectively. The incidence of pressure injury peaked on the 4th and 5th day after hospitalization when categorizing the patients into low- and high-risk groups according to the cutoff values (P < 0.05). Based on relative skin temperature, patients in the high-risk group were more likely to develop pressure injury (hazard ratio = 6.36, 95% confidence interval = 3.91, 10.36), when compared to the other two indicators of blood pressure and blood glucose.ConclusionStringent skin temperature and vascular attributes measurements were necessary for preventing pressure injury. Nursing measures should be taken according to warning sings to reduce the incidence of pressure injury.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号