High temperature and performance in a flight task simulator.
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Adaptation, Physiological↗
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Results for “Sweat analysis”
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Tolerance to heat following cold stress.
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Adult↗
Relationship of sweat electrolytes to apparent life-threatening events (ALTE): a case control study.
Twenty infants aged 25 days to 6 months who were consecutively investigated for apparent life-threatening events (ALTE) with negative results and 20 matched normal controls underwent an iontophoresis sweat test. A statistically significant elevated sweat potassium level (22.1 +/- 8.9 versus 12.4 +/- 6.5 mol/l) was noted in the ALTE patients compared with the control group (p < 0.001). No difference was found, however, between sweat sodium and chloride levels in the two groups. Na/K ratio in sweat was significantly different between the groups (p < 0.001). A between-groups discriminant analysis, using Na/K ratio as a discriminant variable, resulted in 80% accuracy in group assignment. A significant increase in sweat potassium concentration at night compared with day time was evident in ALTE patients. Elevated sweat potassium levels specifically characterized infants who experienced ALTE and may possibly indicate an underlying mechanism involving enhanced sympathetic activity.
Circadian Rhythm↗
Eccrine syringofibroadenoma: report of a case and analysis of cytokeratin expression.
Eccrine syringofibroadenoma (ESFA) is a rare disorder which shows differentiation toward the eccrine sweat apparatus. There is a controversy concerning the pathogenesis and precise differentiation of this tumor. We report a case of ESFA and its differentiation pattern by an analysis of cytokeratin expression. Using paraffin-embedded materials, histopathological and immunohistochemical studies were performed. Staining patterns of the luminal, peripheral, and inner cells of the tumor strands closely matched or mimicked those of the luminal, outer and intermediate cells of the normal eccrine dermal duct, respectively. The case of ESFA reported revealed a pattern of differentiation suggestive of an eccrine duct origin.
Adenoma, Sweat Gland↗
Assessment of anxiety in hospital patients.
There has been research in North America to validate the nursing diagnosis of anxiety. As part of this work, Young used the defining characteristics and developed a tool to measure anxiety. The present research sought to extend that study in the United Kingdom, assess the anxiety-defining characteristics tool and identify key indicators of anxiety that might be useful in clinical practice. Four anxiety measurement tools, drawn from the literature, were used. These were the state trait anxiety inventory, the graphic anxiety scale, the hospital anxiety and depression scale, and the anxiety-defining characteristics tool. A random sample of 79 hospitalized patients were interviewed and their anxiety rated using all four measures. Calculation of Spearman's correlation co-efficients revealed convergent validity between the anxiety-defining characteristics tool and the state trait anxiety inventory and the anxiety score on the hospital anxiety and depression scale. Anxiety levels were found not to be affected by the age or sex of the respondent, or the length of stay or number of previous admissions. Discriminant analysis suggested that six characteristics adequately discriminated anxious subjects: sweating, faintness, tendency to blame others, continual review of things in their mind, focus on self and a lack of self-confidence. The study concluded that there is a scope for further research into these characteristics and their use in clinical practice.
Adult↗
Metabolic alkalosis with hypoelectrolytemia in infants with cystic fibrosis.
BACKGROUND: Infants with cystic fibrosis (CF) can develop episodes of hyponatremic hypochloremic dehydration with metabolic alkalosis when they sweat excessively, which is not caused by sweating in normal infants. We investigated the incidence of the metabolic alkalosis with hypoelectrolytemia in CF infants, the possible risk factors for its occurrence and the importance of the manifestation in the diagnosis of CF. METHODS: In order to evaluate the incidence and the risk factors for the development of this sweat-related metabolic disorder in CF, we reviewed the records of all children diagnosed as having CF before the age of 12 months in a 10-year period. Data analysis included medical history data, clinical features, biochemical parameters (blood pH, serum bicarbonate, sodium, chloride and potassium levels), sweat chloride test values, as well as genetic analysis data. RESULTS: The prevalence of metabolic alkalosis in association with low serum electrolyte concentrations (hyponatremia, hypochloremia, and hypokalemia) in infant CF population in our region was 16.5%. We found no season predilection in its occurrence. Early infant age, breast-feeding, delayed CF diagnosis, heat exhaustion and the presence of severe CF transmembrane conductance regulator mutations are predisposed factors for the development of metabolic alkalosis with hypoelectrolytemia. CONCLUSIONS: The results from our study suggest that metabolic alkalosis with hypoelectrolytemia is a relatively common manifestation of CF in infancy. The possibility of CF should be seriously considered in any infant with this metabolic disorder.
Alkalosis↗
The sweating responses of athletes trained on land and in water.
In order to examine whether different sweating responses of athletes trained on land and in water may be ascribed to changes in the central sudomotor mechanisms and/or those of the peripheral mechanisms of sweat glands, we measured the local sweating rate at the left forearm (mswf) and the left scapula (msws), the frequence of sweat expulsion (Fsw) and body temperatures (mean skin temperature and rectal temperature: Tre) in six runners and five soccer players (R group) and six swimmers (S group) during progressive thermal stress at rest (2 degrees C increase in ambient temperature every 15 min from 35 to 45 degrees C RH = 30-40%). Tre and heart rate at the end of experiment did not differ significantly between the groups (37.31 +/- 0.04 degrees C, 74.5 +/- 7.9 beats.min-1 in the S group and 37.27 +/- 0.07 degrees C, 71.1 +/- 9.0 beats.min-1 in the R group, respectively). The msws and mswf at any given mean body temperature (Tb) were greater in the S group than in the R group. Although the regression line showing the relationship between Fsw and Tb in the S group was shifted to the left of that in the R group, there was no significant difference in the slope of the lines. The msws-Fsw or mswf-Fsw regression line was not different between the two groups. These results indicate that the higher sweating rate in the S group may be ascribed to a difference in the centrally derived sudomotor neural activity, but not to that in the peripheral mechanisms of sweat gland activity.
Adult↗
Clinical predictors of streptococcal pharyngitis in adults.
BACKGROUND: Acute pharyngitis in children is one of the most frequent illnesses for which primary care physicians are consulted. It is caused more frequently by viruses than by bacteria, but it is difficult to differentiate the causative agent by clinical signs alone. Group A Streptococcus accounts for 30% of children with a sore throat, and only in these cases is antibiotic therapy definitely indicated. However, the frequency and symptomatology of streptococcal pharyngitis in adults is not well established. OBJECTIVES: To examine the clinical features that could distinguish sore throat caused by beta-hemolytic group A Streptococcus in adults. METHODS: Patients aged over 16 years old (n = 207) who presented with a sore throat to community clinics were examined and throat cultures were taken. The microbiologic confirmation of Group A Streptococcus was correlated with symptoms and clinical signs by univariate analysis. RESULTS: About 24% of the patients with positive cultures were younger individuals. Chills, absence of cough, pain in swallowing, absence of rhinitis, headache, vomiting, tonsillar exudate, oral malodor, fever > 38 degrees C and sweats had high sensitivity but low specificity for streptococcal pharyngitis. Univariate analysis suggested that chills and pharyngeal exudate had the greatest predictive value for streptococcal pharyngitis (P = 0.044, odds ratio 2.45; P = 0.001, OR 5.49, respectively). When compared with a published scoring method (Centor criteria), large inconsistencies were found. CONCLUSION: Our adult population had a relatively high prevalence of group A Streptococcus, and their presentation differed from that of pediatric patients. In primary care, a throat swab culture is not necessary in adults with a low score (0-1 points).
Acute Disease↗
Urea excretion in human sweat as a tracer for movement of water within the secreting gland.
Previous workers have found that the concentration of urea in human sweat exceeds the concentration of urea in plasma. This fact has been confirmed in the present work and extended by measurements of the concentrations of urea in the sweat and the corresponding concentrations of urea in the plasma over a range of 25- fold variation in the latter. An analysis of the data showed that the ratio of the concentration of urea in sweat to the concentration of urea in plasma, S/P, was independent of the plasma concentration, independent of the absolute flux of urea or water, and independent of the calculated energy expenditure. Two experiments showed that the concentration of urea in sweat followed a rising concentration in plasma with a time lag of approximately 5 minutes; this fact indicates that the accumulation of urea in sweat is a continuous process which is in operation during the observed discharge. These observations suggest that urea is carried into the gland in some precursor solution and subsequently raised to a higher concentration by the reabsorption from this solution of a constant fraction of the water.
Blood↗
Drug testing with alternative matrices II. Mechanisms of cocaine and codeine deposition in hair.
A 10-week inpatient study was performed to evaluate cocaine, codeine, and metabolite disposition in biological matrices collected from volunteers. An initial report described drug disposition in plasma, sebum, and stratum corneum collected from five African-American males. This report focuses on drug disposition in hair and sweat collected from the same five subjects. Following a three-week washout period, three doses of cocaine HCl (75 mg/70 kg, subcutaneous) and three doses of codeine SO4 (60 mg/70 kg, oral) were administered on alternating days in week 4 (low-dose week). The same dosing sequence was repeated in week 8 with doubled doses (high-dose week). Hair was collected by shaving the entire scalp once each week. Hair from the anterior vertex was divided into two portions. One portion was washed with isopropanol and phosphate buffer; the other portion was not washed. Hair was enzymatically digested, samples were centrifuged, and the supernatant was collected. Sweat was collected periodically by placing PharmChek sweat patches on the torso. Drugs were extracted from sweat patches with methanol/0.2 M sodium acetate buffer (75:25, v/v). Supernatants from hair digests, hair washes, and sweat patch extracts were processed by solid-phase extraction followed by gas chromatography-mass spectrometry analysis for cocaine, codeine, 6-acetylmorphine, and metabolites. Cocaine and codeine were the primary analytes identified in sweat patches and hair. Drugs were detected in sweat within 8 h after dosing, and drug secretion primarily occurred within 24 h after dosing. No clear relationship was observed between dose and drug concentrations in sweat. Drug incorporation into hair appeared to be dose-dependent. Drugs were detected in hair within 1-3 days after the last drug administration; peak drug concentrations generally occurred in the following 1-2 weeks; thereafter, drug concentrations decreased. Solvent washes removed 50-55% of cocaine and codeine from hair collected 1-3 days after the last drug dose. These data may reflect removal of drug that was deposited by sweat shortly after dosing. Drug removed by washing hair collected 1-3 weeks after the last dose was minimal for cocaine but variable for codeine. Drug in these specimens was likely transferred from blood to germinative hair cells followed by emergence of drug in growing hair. These findings suggest that drug deposition in hair occurs by multiple mechanisms.
Cocaine↗
Detecting crack and other cocaine use with fastpatches.
A continuing social problem is presented by the large number of individuals who use crack cocaine. Recent research has identified unique pyrolysis products of crack or burned cocaine as anhydroecgonine methylester (AEME) and ecgonidine (ECD) through gas chromatography/mass spectrometry (GC/MS) that allow for the detection of crack use distinct from other cocaine use. However, there have been no large-scale studies to document the presence and prevalence of these substances in sweat. A new sweat-testing appliance called a fastpatch was developed for this study. Through mild heating and a slightly larger collection pad than a standard Pharmchek( trade mark ) sweat patch, this product shows the promise of shorter required wear periods than standard sweat patches, and possibly longer time-periods of detected use. One hundred and eighty subjects wore 360 fastpatch prototypes (one per hand). However, subsequent analysis determined that only one patch per subject was needed to obtain sufficient sweat eluate for GC/MS. Cocaine use was detected in sweat of 92% of subjects through GC/MS, comparing favorably with 91% with EMIT urinalysis. Crack metabolites were detected in 54% of subjects. The predominant analyte detected was AEME. There were no significant differences in detection rates between 15-, 20- and 30-minute wear periods. All wear periods detected both cocaine use in general and crack use successfully. These results suggest that crack use as distinct from other cocaine use can be detected in sweat and that fastpatches are a promising new way to detect drugs of abuse.
Administration, Cutaneous↗
Evaluation of the tilt test in an adult emergency medicine population.
STUDY OBJECTIVE: To evaluate the usefulness of the tilt test in identifying significantly dehydrated or occultly bleeding adult patients in an emergency department. DESIGN: Prospective. SETTING: Urban ED. TYPES OF PARTICIPANTS: Two hundred two ill adult patients with complaints suggestive of dehydration and/or occult blood loss and a control sample of 21 healthy individuals. INTERVENTION: Orthostatic measurements were taken from blood samples from the ill and healthy patients. The estimates of the degree of dehydration measured or calculated were total body water deficit percentage (based on measured serum osmolality), ratio of blood urea nitrogen to creatinine, creatinine, and hematocrit. Multiple historical and physical examination variables related to dehydration or occult bleeding were recorded. MEASUREMENTS AND MAIN RESULTS: Multiple analysis of variance testing of the historical and examination variables in the 166 dehydrated patients revealed the absence of syncope (P = .037) and the lack of axillary sweat (P = .026) to be significantly associated with an increased level of dehydration. Regression analysis of the orthostatic measurements and age with the estimates of dehydration found that orthostatic change in heart rate (P = .0165) and age (P = .0047) demonstrated a very small (r2 = .098) association with the level of dehydration. Orthostatic changes in systolic blood pressure and diastolic blood pressure demonstrated no statistically significant association with level of dehydration. There was wide variation in the tilt test measurements in samples from both the healthy and the ill patients: heart rate, 6.8 +/- 7.8 versus 13.2 +/- 10.5; systolic blood pressure, -2.5 +/- 8.0 versus -8.3 +/- 12.8 mm Hg; and diastolic blood pressure, 5.3 +/- 9.9 versus 0.6 +/- 8.6 mm Hg, respectively. The only parameter that attained statistical significance between the 36 blood-loss patients and the healthy patients was change in systolic blood pressure (P = .001); however, this was not clinically significant (-10.7 +/- 13.7 versus -2.5 +/- 8.0 mm Hg, respectively). CONCLUSION: It appears impossible to define a "positive" tilt test that would adequately identify patients with clinically significant dehydration or blood loss; this is due to the large variance in patients' orthostatic measurements both in a healthy and in an ill state and the lack of a significant correlation of orthostatic measurements to a level of dehydration. Lack of axillary sweat, no complaint of syncope, and younger age all indicate greater degrees of dehydration.
Adolescent↗
Inelastic electron tunneling spectroscopic study of biological compounds in human sweat adsorbed on alumina.
Inelastic electron tunneling spectroscopy has been used for the detection and characterization of biological compounds in human sweat adsorbed on alumina surfaces. The sweat was collected from students and distributed to aqueous and benzene phases by solvent extraction. Both solutions were doped onto alumina surfaces of tunneling junctions, and the vibrational spectra of the adsorbed species were measured by inelastic electron tunneling spectroscopy. Analysis of these tunneling spectra showed that lactic acid in the sweat is extracted with water and selectively adsorbed on alumina. Adsorbed fatty acids were detected from the benzene phase. These biological compounds in the sweat solutions were found to react with the alumina to give about a monolayer of adsorbed carboxylate anions on the surfaces.
Adsorption↗
Isolated elevated sweat chloride concentrations in the presence of the rare mutation S1455X: an extremely mild form of CFTR dysfunction.
Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) have been shown to cause typical cystic fibrosis (CF) and several milder phenotypes. We report on two asymptomatic sisters who had isolated increased sweat chloride concentrations, and in whom systematic scanning of the whole coding region of the CFTR gene revealed the F508del/S1455X genotype.
Adult↗
[Sweat glands in pseudohypoaldosteronism].
Pseudohypoaldosteronism is a rare syndrome occurring during early infancy, which is mainly characterized by salt-depletion crises. Sodium chloride is lost via the kidneys resulting in a reduced sodium level and raised potassium level in the serum, leading to life-threatening disturbances of water and acid-base concentration. The excessive sodium loss seems to be caused by an unresponsiveness of the renal tubules to endogenous and exogenous mineralocorticoids. The colon, salivary and sweat glands, which are also involved in sodium reabsorption, may likewise be affected by the disease. We describe skin changes in two siblings suffering from pseudohypoaldosteronism, who developed seborrheic dermatitis, folliculitis or miliaria rubra-like lesions during salt-depletion crises. Biochemical analysis revealed a highly increased sodium-chloride concentration in the sweat, saliva, urine and stool of both patients. Destructive inflammatory reactions could be demonstrated histologically within and around the dermal sweat glands, thus indicating the important role of the sweat system in the pathogenesis of skin lesions in pseudohypoaldosteronism.
Child, Preschool↗
Excretion of sweat and urine pyridinoline crosslinks in healthy controls and subjects with established metabolic bone disease.
Convenient techniques for measuring rates of bone turnover have been developed in recent years with the advent of biochemical markers of bone metabolism. One recent of these techniques is a collection method and quantitative enzyme immunoassay for free pyridinoline crosslinks in human sweat. The concentrations of pyridinoline crosslinks in 5-day sweat collections and first morning void and 24-hour urine collections from healthy subjects and subjects with established metabolic bone disorders were determined. T-scores were higher in the sweat system than in the urine system by up to 10-fold in postmenopausal subjects, women with hyperparathyroidism, and subjects with postmenopausal osteoporosis. For subjects with postmenopausal osteoporosis, receiver-operating characteristic curve analysis yielded areas under the curve of 0.699, 0.629, and 0.520 for sweat pyridinoline, first morning void urine pyridinoline, and 24 hour urine pyridinoline respectively. The areas under the curve of the sweat and first morning void urine measurements were significantly greater (p<0.05) than the 24-hour pyridinoline measurements. Healthy postmenopausal subjects and subjects with postmenopausal osteoporosis were monitored before and during estrogen replacement therapy or alendronate therapy. Sweat pyridinoline values declined by 49.0 +/- 12.4% and 19.4 +/- 19.9% for estrogen and alendronate subjects respectively. We conclude that this non-invasive technique is a sensitive and specific measure of bone resorption and is appropriate as an adjunct to techniques such as bone density and may also be useful in monitoring of response to anti-resorptive therapies.
Adult↗
Occurrence of the spinal reflex due to skin pressure in sudomotor and cutaneous vasoconstrictor nerve system of humans.
The effects of skin pressure applied to one side of the waist on sudomotor and vasoconstrictor nerve activity were compared with the effects on sweating and cutaneous blood flow in humans. The sweat rate and cutaneous blood flow were measured on left and right dorsal feet. Skin sympathetic nerve activity (SSNA) was recorded by microneurography from a microelectrode inserted in left and right peroneal nerves. Skin pressure was applied in a supine position to the area over the left or right anterior superior iliac spine under warm (T(a): 30-36 degrees C) and cool (T(a): 19-23 degrees C) conditions. Sudomotor and vasoconstrictor bursts were identified for quantitative analysis. The skin pressure increased the contralateral/ipsilateral ratio of the sweat rate. It also increased the contralateral/ipsilateral ratio of the cutaneous blood flow and the contralateral/ipsilateral ratio of the sudomotor burst amplitude. However, skin pressure did not induce any significant changes in the contralateral/ipsilateral ratio of the vasoconstrictor burst amplitude. The results indicate that an asymmetrical reflex effect of skin pressure on vasoconstrictor nerve activity was absent, suggesting that, whereas the ipsilateral suppression of sweating elicited by skin pressure was mediated by the sudomotor nerve system, the ipsilateral suppression of cutaneous blood flow was not mediated by the vasoconstrictor nerve system. Thus, the occurrence of the spinal reflex due to skin pressure is not uniform between the sudomotor and the vasoconstrictor nerve systems, which represent different organizations at the level of spinal cord.
Adult↗
Mitotic count is not predictive of clinical behavior in hidradenoma papilliferum of the vulva: a clinicopathologic study of 19 cases.
Although it is generally recognized that some benign sweat gland neoplasms may show appreciable mitotic activity, there are few reports of its quantitative analysis in specific tumor types or of its correlation with clinical behavior. The presence of a large number of mitoses in a sweat gland tumor for which the histologic criteria of malignancy are not well defined, particularly in association with nuclear abnormalities, may produce a considerable diagnostic challenge. We recently encountered such a problem in a putative case of hidradenoma papilliferum. Therefore, we have undertaken a retrospective clinicopathologic study of 19 cases originally diagnosed as hidradenoma papilliferum or probable hidradenoma papilliferum, with a particular emphasis on the relationship of the mitotic index to clinical behavior. The age range of the cases was 41 to 92 years (mean 56.8 years). In all cases in which the margins could be evaluated, the tumors were well circumscribed (15/15), but in 4 cases circumscription could not be assessed because the specimen was fragmented. All showed focal mild nuclear pleomorphism. Mitoses were present in both epithelial and myoepithelial cells. The mitotic index varied from 0 to 5.3 mitoses/mm2 (0 to 13 mitoses per 10 high power fields (hpf); 1 hpf=0.246 mm2), with a mean of 2.4/mm2 (6/10 hpf) and a median of 0.8/mm2 (2/10 hpf). No atypical mitoses were identified. The proliferative fraction (MIB-1 index) correlated with the mitotic index (correlation coefficient 0.94; P<0.0001) and varied from 1% to 10.5% (mean 3.9%, median 3.0%). There were no recurrences or metastases over a mean period of 8 years. Consequently, we have shown that the mitotic index in these lesions can be variable and often high, but it does not predict a more aggressive outcome.
Adenoma, Sweat Gland↗