Rethinking the causes of pilonidal sinus disease: a matched cohort study

Our understanding of pilonidal sinus disease (PSD) is based on a paper published 29 years ago by Karydakis. Since then, surgeons have been taught that hair more easily penetrates wet skin, leading to the assumption that sweating promotes PSD. This postulate, however, has never been proven. Thus we used pilocarpine iontophoresis to assess sweating in the glabella sacralis. 100 patients treated for PSD and 100 controls were matched for sex, age and body mass index (BMI). Pilocarpine iontophoresis was performed for 5 min, followed by 15 min of sweat collection. PSD patients sweated less than their matched pairs (18.4 ± 1.6 µl vs. 24.2 ± 2.1 µl, p = 0.03). Men sweated more than women (22.2 ± 1.2 µl vs. 15.0 ± 1.0 µl in non-PSD patients (p < 0.0001) and 20.0 ± 1.9 µl vs. 11.9 ± 2.0 µl in PSD patients (p = 0.051)). And regular exercisers sweated more than non-exercisers (29.1 ± 2.9 µl vs. 18.5 ± 1.6 µl, p = 0.0006 for men and 20.7 ± 2.3 µl vs. 11.4 ± 1.4 µl, p = 0.0005 for women). PSD patients sweat less than matched controls. Thus sweating may have a protective effect in PSD rather than being a risk factor.

Predictors for the quantity not sufficient sweat collection for ionic conductivity in newborns and young infants

Background: Sweat conductivity (SC) is a semi-automated method widely used as a screening test for Cystic Fibrosis. Quantity not sufficient (QNS) is defined when collecting a volume lower than 15 μl of sweat during 30 minutes. Objective: To verify the rate and factors related to QNS for SC in newborns and young infants. Methods: Newborns and infants aged less than three months that had undergone sweat conductivity after two abnormal immunoreactive trypsinogen results, were recruited prospectively and consecutively. Statistical analysis included descriptive statistics, univariate and multivariate logistic regression. Results: A total of 1020 individuals were included. Among them, the rate of QNS was 8.9%. Subjects with gestational age <37 weeks (OR=5.0), birth weight <2.000g (OR=3.5), and daily weight gain <25g/day (OR=3.4) were more likely to produce an insufficient quantity of sweat. Conclusion: Our results suggest that QNS rates for SC could successfully fulfill the Cystic Fibrosis Foundation standards in newborns and young infants. In cases of QNS, SC should be scheduled as early as possible when the infant is older than 37 weeks (corrected age).

Use Of Canine Olfactory Detection For COVID-19 Testing Study On U.A.E. Trained Detection Dog Sensitivity

ABSTRACTThis study aimed to evaluate the sensitivity of 21 dogs belonging to different United Arab Emirates (UAE) Ministry of Interior (MOI), trained for COVID-19 olfactory detection.The study involved 17 explosives detection dogs, two cadaver detection dogs and two dogs with no previous detection training. Training lasted two weeks before starting the validation protocol. Sequential five and seven-cone line-ups were used with axillary sweat samples from symptomatic COVID-19 individuals (SARS-CoV-2 PCR positive) and from asymptomatic COVID-19 negative individuals (SARS-CoV-2 PCR negative). A total of 1368 trials were performed during validation, including 151 positive and 110 negative samples. Each line-up had one positive sample and at least one negative sample. The dog had to mark the positive sample, randomly positioned behind one of the cones. The dog, handler and data recorder were blinded to the positive sample location.The calculated overall sensitivities were between 71% and 79% for three dogs, between83% and 87% for three other dogs, and equal to or higher than 90% for the remaining 15 dogs (more than two thirds of the 21 dogs).After calculating the overall sensitivity for each dog using all line-ups, “matched” sensitivities were calculated only including line-ups containing COVID-19 positive and negative samples strictly comparable on confounding factors such as diabetes, anosmia, asthma, fever, body pain, diarrhoea, sex, hospital, method of sweat collection and sampling duration. Most of the time, the sensitivities increased after matching.Pandemic conditions in the U.A.E., associated with the desire to use dogs as an efficient mass-pretesting tool has already led to the operational deployment of the study dogs.Future studies will focus on comparatives fields-test results including the impact of the main COVID-19 comorbidities and other respiratory tract infections.

Use of Canine Olfactory Detection for Covid-19 Testing Study on U.A.E. Trained Detection Dog Sensitivity

This study aimed to evaluate the sensitivity of 21 dogs belonging to different united arab emirate administrations, trained for covid-19 olfactory detection. The study involved 17 explosives detection dogs, two cadaver detection dogs and two dogs with no previous detection training. Training lasted two weeks before starting the validation protocol. Sequential five and seven- cone line-ups were used with axillary sweat samples from 151 symptomatic covid-19 individuals (sars-cov-2 pcr positive) and from 110 asymptomatic covid-19 negative individuals (sars-cov-2 pcr negative). Each line-up had one positive sample and at least one negative sample. The dog had to mark the positive sample, randomly positioned behind one of the cones. The dog, handler and data recorder were blinded to the positive sample location. The calculated overall sensitivities were between 71% and 79% for three dogs, between 83% and 87% for three other dogs and equal to or higher than 90% for the remaining 15 dogs (more than two thirds of the 21 dogs). After calculating the overall sensitivity for each dog using all line- ups, “matched” sensitivities were calculated only including line-ups containing covid-19 positive and negative samples strictly comparable on confounding factors such as diabetes, anosmia, asthma, fever, body pain, diarrhoea, sex, hospital, method of sweat collection and sampling duration. Most of the time, the sensitivities increased after matching. Pandemic conditions in the U.A.E.., associated with the desire to use dogs as an efficient mass-pretesting tool has already led to the operational deployment of the study dogs. Future studies will focus on comparatives fields-test results including the impact of the main covid-19 comorbidities and other respiratory tract infections.

Bio-inspired fractal textile device for rapid sweat collection and monitoring

In this study, a new design concept in sweat collection was developed to achieve rapid and intact sweat sampling for analytical purposes. Textiles with fast water wicking properties were first...

LCMS Measurement of Steroid Biomarkers Collected from Palmar Sweat.

<div>Human eccrine sweat contains numerous biomarkers which can provide information on health,</div><div>performance, and aging. Non-invasive collection and measurement of biomarkers has become</div><div>especially important in recent times given viral outbreaks like SARS-CoV-2. In the current study</div><div>we describe a method of sweat collection from palmar surfaces in participants via surface capture</div><div>using glass beads and the resulting analysis of biomarkers from very low volumes of sweat using</div><div>liquid chromatography mass spectrometry with selected ion monitoring. Study participants</div><div>underwent a cognitive and physical stress task with easy and hard conditions with sweat being</div><div>collected after each task. Resulting analysis found a signal for 22 steroid biomarkers and we</div><div>report detailed information on selected biomarkers, given their applicability to timely real-world</div><div>exemplars, including cortisol, dehydroepiandrosterone, allopregnanolone, estrone, aldosterone,</div><div>and 20a/b-dihydrocortisone.</div><div><br></div>

LCMS Measurement of Steroid Biomarkers Collected from Palmar Sweat.

<div>Human eccrine sweat contains numerous biomarkers which can provide information on health,</div><div>performance, and aging. Non-invasive collection and measurement of biomarkers has become</div><div>especially important in recent times given viral outbreaks like SARS-CoV-2. In the current study</div><div>we describe a method of sweat collection from palmar surfaces in participants via surface capture</div><div>using glass beads and the resulting analysis of biomarkers from very low volumes of sweat using</div><div>liquid chromatography mass spectrometry with selected ion monitoring. Study participants</div><div>underwent a cognitive and physical stress task with easy and hard conditions with sweat being</div><div>collected after each task. Resulting analysis found a signal for 22 steroid biomarkers and we</div><div>report detailed information on selected biomarkers, given their applicability to timely real-world</div><div>exemplars, including cortisol, dehydroepiandrosterone, allopregnanolone, estrone, aldosterone,</div><div>and 20a/b-dihydrocortisone.</div><div><br></div>

Skin-interfaced microfluidic devices with one-opening chambers and hydrophobic valves for sweat collection and analysis

Soft, skin-interfaced microfluidic platforms are capable of capturing, storing, and assessing sweat chemistry and total sweat loss, which provides essential insight into human physiological health.

Resettable skin interfaced microfluidic sweat collection devices with chemesthetic hydration feedback

Recently introduced classes of thin, soft, skin-mounted microfluidic systems offer powerful capabilities for continuous, real-time monitoring of total sweat loss, sweat rate and sweat biomarkers. Although these technologies operate without the cost, complexity, size, and weight associated with active components or power sources, rehydration events can render previous measurements irrelevant and detection of anomalous physiological events, such as high sweat loss, requires user engagement to observe colorimetric responses. Here we address these limitations through monolithic systems of pinch valves and suction pumps for purging of sweat as a reset mechanism to coincide with hydration events, microstructural optics for reversible readout of sweat loss, and effervescent pumps and chemesthetic agents for automated delivery of sensory warnings of excessive sweat loss. Human subject trials demonstrate the ability of these systems to alert users to the potential for dehydration via skin sensations initiated by sweat-triggered ejection of menthol and capsaicin.