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Nicotine monitoring in sweat with a sweat patch.

In recent years, remarkable advances in sensitive analytical techniques have enabled the analysis of drugs in unconventional samples, such as sweat. In a study conducted with cigarettes smokers and nonsmokers, PharmChek sweat patches were applied to 29 subjects for 72 h. Nicotine was extracted in 5 ml methanol in the presence of 200 ng nicotine-d4, used as internal standard. After 20 min agitation, the methanolic solution was evaporated to dryness in the presence of 10 microl octanol to ensure nonvolatility of nicotine. Nicotine was determined using gas chromatography coupled to mass spectrometry after separation on a 30-m capillary HP5 MS column. The assay was linear in the range 50-2500 ng/patch, with an extraction recovery of 76+/-5%. Limit of detection was 10 ng/patch. Nicotine concentrations in sweat were not detected for the nonexposed nonsmokers (n = 8), 87 to 266 ng/patch for the passive smokers (n = 6) and 150 to 2498 ng/patch for the smokers (n = 15). This study demonstrated a useful application of the sweat patch for monitoring tobacco exposure.

Adult↗

The influence of sweating on the heat transmission properties of cold protective clothing studied with a sweating thermal manikin.

One of the objectives of the European SUBZERO project was to study the influence of sweat evaporation and condensation on the heat transmission properties of cold protective clothing. With the sweating thermal manikin Coppelius, water vapour transfer through and water condensation in the clothing can be determined simultaneously with the thermal insulation. In this study, 4 cold protective ensembles, intended for use temperatures between 0 and -50 degrees C, were measured with the dry manikin and at 2 different sweating rates. In addition, the ensembles were measured with non-sweating thermal manikins and in wear trials.

Body Temperature Regulation↗

The relation between sweat rate and weight loss when sweat is dripping off the body.

1. The relation between the rate of sweat production, S, and the rate of weight loss, W, has been examined under conditions in which the rate of evaporation was small.2. S could be found from W provided that a film of liquid was maintained over the skin surface. This could be achieved initially by immersing the subject in water containing detergent. Thereafter the film was maintained so long as the rate of weight loss exceeded about 10 g/min.3. When the rate of weight loss was changing and the rate of evaporation was constant, S could be calculated as W + 2.5 W.4. When the subject was constantly sprayed with water while being weighed, the correction for W became negligible. In this case there was no lower limit to the sweat rate which could be measured, but spraying considerably reduced the accuracy of the measurement.5. The output of sweat from a ventilated capsule on the forearm correlated well with estimates of central sweating drive based on weight measurements corrected for hidromeiosis.

Body Weight↗

Dry skin (xerosis) in patients undergoing maintenance haemodialysis: the role of decreased sweating of the eccrine sweat gland.

The aetiology and the pathophysiological mechanisms underlying the development of dry skin in uraemia are still unclear, but the hydration status of stratum corneum clearly influences the appearance of skin. The xerotic skin texture is often referred to as 'dry skin' and has been suggested as a cause of uraemic pruritus. To understand the aetiology of dry skin in uraemia we measured the status of skin surface hydration of uraemic patients with the corneometer and skin surface hydrometer, the functional capacity and the urea concentration of stratum corneum and the response of eccrine sweat gland to sudorific agent (0.05% pilocarpine HCL) in 18 age-matched haemodialysis patients and 10 healthy volunteers. We also performed the water sorption-desorption test to uraemic and control subjects after application of urea in various concentrations. Uraemic patient's skin showed decreased water content compared to control subjects. However, we found no correlation between dry skin and pruritus. Although the urea concentration of the horny layer in uraemic patients was elevated compared to control subjects (28.2 microgram/cm2 vs 5.04 micrograms/cm2, P < 0.05), its moisturizing effect to relieve pruritus is questionable because its artificial application revealed no improvement of the functional capacity of horny layer in concentration 5 times higher than the physiological concentration. Uraemic patients showed decreased sweating response to sudorific agent. In conclusion, the functional abnormalities of eccrine sweat glands may be account for dry skin in uraemic patients at least in part, but there is no correlation between xerosis and pruritus.

Adult↗

Effect of activated sweat glands on the intensity-dependent sweating response to sustained static exercise in mildly heated humans.

Changes in the number of activated sweat glands (ASGs) and sweat output per gland (SGO) with increased exercise intensity during sustained static exercise were investigated. Fourteen male subjects performed 20, 35, and 50% maximal voluntary contraction (MVC) for 60 s with the right hand (exercised arm) at an ambient temperature of 35 degrees C and 50% relative humidity. Although sublingual, local skin, and mean skin temperatures remained essentially constant throughout the exercise at each intensity, the sweating rate (SR) of nonglabrous skin on the nonexercised left forearm increased significantly with a rise in exercise intensity (p<0.05). Changes in the number of ASGs with rising exercise intensity paralleled changes in the SR, but the SGO did not change markedly with altered exercise intensity. These results suggest that in mildly heated humans, at less than 50% MVC, the increase in the SR from nonglabrous skin with rising exercise intensity during sustained static exercise is dependent on changes in the number of ASGs and not on SGO.

Adult↗

Sweating patterns in humans: II. Heat-induced forehead sweating and cutaneous temperature in healthy individuals.

A comparison of heat-induced forehead sweating and cutaneous temperature patterns has been carried out in 17 healthy individuals (a total of 54 measurements). Only minor asymmetries in facial sweating and temperature were observed. No significant correlation between sweating and cutaneous temperature was found. The reproducibility of the method was excellent.

Adult↗

'Rusters'. The corrosive action of palmar sweat: I. Sodium chloride in sweat.

Sweat from 8 'rusters' and 8 control persons was examined for its sodium concentration. Sweating was induced by iontophoresis of pilocarpine on the distal forearm. In no case did the concentrations exceed the normal upper limit for this procedure, and no difference was found between the two groups. In this way the study failed to confirm earlier reports of elevated sodium chloride concentrations in sweat from 'rusters'. Proposals of a relationship between 'rusters' and patients with pancreatic cystic fibrosis were not substantiated. Hyperhidrosis of the palms and volar surfaces of the fingers was present in all 'rusters'. This seemed to be the main cause of the corrosive tendency, and patients referred for palmar hyperhidrosis were found to produce corrosion similar to the 'rusters'. Topical application of aluminium chloride hexahydrate in a 25% solution in absolute ethyl alcohol proved effective against both hyperhidrosis and the corrosive tendency.

Administration, Topical↗

Changes in the number of active sweat glands (palmar sweat index, PSI) during a distressing film.

Changes of the number of active palmar sweat glands (palmar sweat index, PSI) as assessed by the plastic finger-print method were studied in two groups of female students (n = 21 each). In both samples experiments involved an initial adaptation period, several relaxation phases and an activation period (presentation of a movie). The film was shown 10 min earlier in Group 1, for which in turn follow-up was twice as long. Prints for determination of PSI were taken every 2.5 min from the forefinger and ring finger of the left hand, and recordings of SCL, SF (number of spontaneous fluctuations) and HR were made during the corresponding intervals. Both within- and between-groups comparisons showed an increase of PSI during the activation period and a decrease afterwards. Similar effects were observed for SCL, SF and affective and somatic arousal assessed by a state questionnaire. A decrease of PSI and parameters of electrodermal activity during the first measurements indicated an initial reaction to the assessment procedure itself. Both within-subject and between-subjects correlations between PSI from both fingers showed high parallel test reliabilities, while correlations with electrodermal variables indicated a common physiological basis.

Adult↗

Immunohistochemical demonstration of ferritin in sweat gland and sweat gland neoplasms.

Using a rabbit anti-human liver ferritin antibody, we examined the binding patterns of this reagent in normal skin and observed a unique binding pattern limited to the outermost layer of the eccrine duct. Examination of a variety of sweat gland neoplasms revealed 2 distinct patterns. One was the binding of this antibody to the outermost layer of cells in the epithelial cords of syringoma, producing a characteristic ring when seen in cross-section. This pattern of binding did not occur in other neoplasms known to be related to the eccrine duct such as dermal duct tumor and eccrine poroma. Only sparse sporadic binding occurred in other eccrine and apocrine neoplasms. A second characteristic binding pattern, not related to that noted in syringoma and diffuse in pattern, was seen in acrospiroma and in a number of adnexal carcinomas. Diffuse ferritin expression has been described in malignant neoplasms in tissues other than skin. Diffuse ferritin staining of certain sweat gland neoplasms may be an indication of biologic activity and potential aggressivity of these neoplasms.

Biopsy↗

[The number of active sweat glands (PSI, palmar sweat index) as a psychophysiologic parameter].

Two laboratory studies were carried out to assess the behavior of the active palmar sweat glands in both an active and a passive coping situation. Stressor in study I was watching a distressing film, in study II mental arithmetic. Subjects were male students, 17 in experiment I, 20 in experiment II. Both experiments involved a 10-minute baseline phase, a 10-minute stress period, and a follow-up of 10 minutes. PSI was assessed at 90-sec intervals and averaged across phases, as were readings in SCL, SCR, heart rate, diastolic and systolic blood pressure. PSI could be determined in 16 subjects of each study. In both experiments PSI increased significantly from baseline to stress (p less than 0.1%) and decreased from stress to follow-up (p less than 0.1%), and thus proved to be the most sensitive indicator for stress. The interrater reliability for counting the number of active sweat glands was high when the area for evaluation was defined unambiguously. Since the assessment of the PSI does not require a sophisticated technology and is thus also applicable in field research, we suggest giving more consideration to this variable.

Adult↗

Comparisons of eccrine sweat gland anatomy in genetic, chromosomal, and other diseases, and a suggested procedure for use of sweat gland measurements in differential diagnosis.

Statistical analysis of the dimensions of microdissected eccrine sweat glands (duct length, coil volume, ratio of coil volume to duct length, and axis ratio of coil) was performed for several diseases (cystic fibrosis of the pancreas, Werdnig-Hoffmann disease, tetralogy of Fallot, chronic renal disease, and trisomies 13, 18, and 21) using both individual and grouped age-matched control patients. Duct length, coil volume, and the ratio of the two all rise with age. Eccrine gland duct length was found to be significantly large in tetralogy of Fallot and Werdnig-Hoffmann disease and small in chronic renal disease (less so in males than in females, trisomy 13 and trisomy 18). Secretory coil volume was significantly smaller than normal in trisomy 21 (Down syndrome) and in chronic renal disease, and the ratio of coil volume to duct length was low in trisomy 21 and chronic renal disease. The shape of the secretory coil (axis ratio) was possibly abnormal in trisomy 13. Gland dimensions were normal for cystic fibrosis. Using the multivariate procedure of discriminant analysis, it was found that sweat gland measures significantly contributed to the differentiation of diseases, after adjustments were made for variations in age-at-death. This suggested the possibility that criteria for distinction of clinically similar genetic, metabolic, or chromosomal diseases by study of the anatomic properties of eccrine glands obtained by skin biopsy could be developed. A procedure of analysis comparing the "percentage of normal" of gland dimensions for each disease to control values, and thereby differentiating disease categories on the basis of the "percentage of normal" values, is presented.

Age Factors↗

The effects of a psychological "stressor" and raised ambient temperature on the pharmacological responsiveness of human eccrine sweat glands: implications for sweat gland hyper-responsiveness in anxiety states.

The responsiveness of eccrine sweat glands to local intradermal injections of carbachol was studied in six male healthy volunteers using a plastic paint impression method. A psychological "stressor" (performance of a mental arithmetic task) resulted in an increase in the sizes of the responses evoked by carbachol, this being reflected in a higher value of Emax obtained under the "stress" than under the "non-stress" condition. A rise in ambient temperature from 20 degrees C to 35 degrees C resulted in qualitatively similar effects on the dose-response curve. These results are discussed in the context of recent observations on the pharmacological responsiveness of sweat glands in patients suffering from anxiety neurosis.

Adult↗

Analysis of sweat evaporation from clothing materials by the ventilated sweat capsule method.

The local influence of three clothing materials i.e. silk, cotton and nylon, in (1) full or (2) partial skin contact or (3) at 3 mm from the skin, on sweat evaporation from the chest skin surface of human subjects was studied. The hygrometer-ventilated capsule method was used and sweating was induced at ambient thermoneutrality by a central heat load following lower-leg immersion in water at 43 degrees C. The presence of clothing delayed the rise in capsule relative humidity (CRH) induced by heat loading. During the first 6 min of heating, CRH rose more steeply with clothing that was in full skin contact than with clothing that had partial or no contact. The rate of decrease in CRH from 1 min to 6 min after heating was not influenced by the presence of clothing or by the different degrees of skin contact. The subsequent return of CRH to the pre-heating level was delayed most by cotton, less by silk and least by nylon. For silk and nylon, partial contact with the skin prolonged the return to control conditions, as compared with full skin contact.

Adult↗

[Detection of nicotine in eccrine sweat after stimulation of sweat glands during nicotine withdrawal].

The presence of nicotine in sweat obtained from smokers and one non-smoker exposed to tobacco smoke after 4 h to 8 days of nicotine-free time was investigated. Following stimulation of the eccrine glands, sweat samples were taken every hour for 6 h. The total nicotine concentrations, i.e. the sum of nicotine and its metabolites, were determined by radioimmunoassay. The presence of unchanged nicotine was revealed by gas chromatography/mass spectrometry.

Adolescent↗

Biology of sweat glands and their disorders. II. Disorders of sweat gland function.

Part I of this article (J Am Acad Dermatol 1989; 20:537-63) focused on normal sweat gland function. Part II provides a discussion of hyperhidrosis and hypohidrosis. Hyperhidrotic disorders affect the palms and soles and the axillae and are associated with previous spinal cord injuries, peripheral neuropathies, brain lesions, intrathoracic neoplasms, systemic illness, and gustatory sweating. Hypohidrotic disorders include anhidrotic ectodermal dysplasia, hereditary sensory neuropathy, Holmes-Adie syndrome, and generalized anhidrosis.

Humans↗

[The number of active sweat glands (PSI, palmar sweat index) in stress caused by blood donation].

The number of active sweat glands (PSI), heart rate, systolic (SBP) and diastolic blood pressure (DBP) were assessed every 2 minutes in 109 male blood donors. Three measurements were taken at the beginning (adaptation phase), three later but before blood donation (baseline), one during the venous puncture (phase 3), three thereafter but still during donation (phase 4), and four after removal of the cannula (phase 5). Analysis of variance yielded significant differences between phases; PSI and SBP behaved similarly, decreasing from adaptation to baseline, rising during puncture, and decreasing again thereafter. Mean within-subject correlations between variables were significantly above 0. Between-subjects correlations were significantly negative for PSI and DBP. This is best explained by the influence of age on both variables. Correlations of PSI values as determined by three raters had a mean of 0.90. The study shows that the PSI is a very sensitive indicator of stress that is easily accessible also in field studies.

Adult↗

The ultrastructure of the sweat gland duct of the ox, sheep and goat before and during sweating.

The duct of the cow, sheep and goat can be divided into two main parts, the intrafollicular region and the intradermal region. Three sub-regions, namely the perifollicular zone, the duct body and the duct/fundus transition zone, can be distinguished within the latter. In the outer portion of the hair follicle, the luminal surface was keratinized but the presence, in the cow and sheep, of surface microvilli with closely associated vesicles deeper within this layer suggested the possibility of a reabsorptive role. The intradermal duct had junctional complexes at the luminal extremity throughout its length. Gap junctions were observed between basal cells only in the lower part of the duct body. Dovetailing between luminal cells in the intradermal duct was barely noticeable in the cow but prominent in the goat. In the duct/fundus transition zone of all three species there was evidence of cell differentiation, the potential significance of which is discussed. There was little change in the ultrastructure of the duct in any of the three species, other than an increase in lumen size, as a result of heat exposure and sweating activity.

Animals↗

Sweat testing for cystic fibrosis: errors associated with the in-situ sweat test using chloride ion selective electrodes.

The in-situ sweat test is prone to errors from various sources. This paper examines errors due to evaporation, absorption of water into the skin, and pressure of the electrode on the skin. Only evaporation caused serious errors. The accuracy and precision when measuring small chloride/sweat samples on the skin are not significantly worse than when measuring bulk solutions.

Chlorides↗