Axillary Samples Research Articles

A large scale study of portable sweat test sensor for accurate, non-invasive and rapid COVID-19 screening based on volatile compound marker detection

This study established a novel infield sensing approach based on detection of the volatile compound markers in skin secretions. This was based on analysis of volatile compounds in axillary sweat samples collected from RT-PCR-proven Coronavirus disease 2019 (COVID-19) positive and negative populations using gas chromatography-mass spectrometry (GC–MS). The analysis proposed the possible markers of the monoaromatic compounds and ethyl hexyl acrylate. A portable photo ionization detector (PID) incorporated with the selective material towards the marker compounds was then developed with the pressurized injection approach. This provided the accuracy of 100% in the research phase (n = 125). The developed approach was then applied for screening of 2207 COVID-19 related cases covering the periods of the Alpha, Beta, Delta and Omicron variants of SARS-CoV-2 infection in Bangkok, Thailand. This offered the sensitivity, specificity and accuracy ranges of 92–99, 93–98 and 95–97%, respectively.

Sweat-based stress screening with gas chromatography–ion mobility spectrometry and electronic nose

BackgroundDiagnosis of stress generally involves uses of questionnaires which can provide biased results. The more reliable approach relies on observation of individual symptoms by psychiatrists which is time consuming and could not be applicable for massive scale screening tests. This research established alternative approaches with gas chromatography–ion mobility spectrometry (GC–IMS) and electronic nose (e-nose) to perform fast stress screening based on fingerprinting of highly volatile compounds in headspaces of sweat. The investigated samples were obtained from 154 female nurse volunteers who also provided the data of questionnaire-based mental health scores with the high stress cases confirmed by psychiatrists. ResultsThe interviews by psychiatrists revealed 14 volunteers with high stress. Their axillary sweat samples and that from 32 nurses with low/moderate stress (controls) were collected onto cotton rods and analysed with GC–IMS. The possible marker peaks were selected based on the accuracy data. They were tentatively identified as ammonia, diethyl ether, methanol, octane, pentane, acetone and dimethylamine which could involve different endogenous mechanisms or the relationships with the local microbiomes. The data were further analysed using partial least squares discriminant analysis with the receiver operating characteristic curves showing the optimum accuracy, sensitivity and selectivity of 87%, 86% and 88%, respectively. Providing that the samples were obtained from the nurses without deodorant uses, the high stress cases could be screened using e-nose sensors with the accuracy of 89%. The sensor responses could be correlated with the marker peak area data in GC–IMS with the coefficients ranging from −0.70 to 0.80. SignificanceThis represents the first investigation of highly volatile compound markers in sweat for high stress screening. The established methods were simple, reliable, rapid and non-invasive, which could be further adapted into the portable platform of e-nose sensors with the practical application to perform the screening tests for nurses in Phra Nakorn Si Ayutthaya hospital, Thailand.

Canine olfactory detection and its relevance for the medical identification of patients with COVID-19

Introduction The assessment of Volatile Organic Compounds (VOCs) in exhaled breath or sweat represents a potential non-invasive and rapid diagnostic tool for respiratory diseases. Objective To determine if trained dogs can reliably identify the odour associated with COVID19. Methods This is a monocentric prospective study carried out in the Emergency Department (ED) of a university hospital fromJulyto November 2021.Axillary sweat samples from all patients were collected bytwo trained health care professionals. The samples were collected in the form of sterile gauze swabs placed under the armpits for at least 4 h for each patient.Then, Tubes wereshiftedto the double-blind dog training centre for VOC detection by two individuals. Results Dogs were tested using a total of 129 axillary sweat samples; 69 of the 107 patients who tested positive for COVID-19 based on their odours had a positive PCR/Antigen test and 19 of the 22 patients who were tested negative for COVID-19 by the dogs had a negative PCR test. The sniffer dog infection detection method had a sensitivity of 95.83% and a specificity of 33.33%. The PPV was 64.49% and the NPVwas 86.36%. The measurement of the intensity of the connection between the two variables (disease/sign) was very strong (Q = 0.84). This link is statistically significant (X2 = 19.13) with a probability p ≤ 0.001. Conclusion Overall, the use of trained detection dogs as a screening method for SARS-CoV-2 is an interesting avenue of research that warrants further exploration and validation.

Diagnostic performance analysis of Xpert MTB/RIF in lymph node tuberculosis: A retrospective study

AimsTo retrospectively analyze the diagnostic efficacy of Xpert MTB/RIF (Xpert) in lymph node tuberculosis (LNTB). MethodsSensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the curve (AUC) of Xpert, pathological examination and culture for LNTB were calculated. Results421 suspected LNTB cases were categorized into the LNTB group (377 cases) and non-LNTB group (44 cases). The sensitivities of Xpert, pathological examination, and culture were 72.15%, 20.69%, 30.24%, respectively, with NPVs of 29.53%, 12.83%, 14.33%. The AUC values were 0.861, 0.603, 0.651, respectively. The sensitivity of Xpert varied across sample types: tissue (64.73%), puncture fluid (74.42%), and pus (96.05%). For specific lymph node locations, the sensitivity was head-and-neck (72.51%), mediastinal (84.21%), and axillary (45.83%). ConclusionsXpert demonstrates high diagnostic value for LNTB, particularly in pus samples. It also performs better in mediastinal and head-and-neck lymph node samples compared to axillary lymph node samples.

Identification of coronavirus disease marker compounds in sweat with comprehensive two dimensional gas chromatography using multiloop splitter-based non-cryogenic artificial trapping modulation system

This study applied comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GCMS–) for analysis of volatile compounds in headspaces of axillary swab samples of RT-PCR or antigen test kit proven COVID-19 positive and negative volunteers in Bangkok, Thailand. The separation was performed using a conventional Deans switch (DS) based heartcut system with an additional splitter system located between the first (1D) column (30 m) and the DS. The splitter consisted of deactivated fused silica (DFS) columns connected into three loops with the progressively doubled perimeters of the downstream loops. An artificial GC × GC result was obtained by applying a periodic heartcut (H/C) event within every artificial modulation period (PAM) of 1.14 min, selectively transferring the analytes onto the second (2D) column (30 m). Chemometric analysis including feature selection was used to identify significantly altered metabolites between the positive and negative groups. Fourteen significant metabolites were tentatively identified, including p-cymene, linalool, and 2,6,11-trimethyldodecane. The marker peak area thresholds were optimized by generating receiver operating characteristic (ROC) curves showing accuracy, sensitivity and selectivity within the ranges of 94–98%, 93–97% and 94–100%, respectively. Based on these results, we hypothesize that SARS-CoV-2 infection disrupts the metabolism of volatile metabolites in sweat, or impacts the microbiome, changing the volatile profile of sweat in infected patients.

Fine-needle aspiration biopsy of axillary lymph nodes: Areliable diagnostic tool for breast cancer staging.

Pathologic evaluation of sentinel lymph node biopsy (SLNB) samples is crucial for axillary staging in patients newly diagnosed with breast cancer. Patients with pathologic evidence of nodal metastasis scheduled for upfront surgery typically also undergo axillary lymph node dissection (ALND). Although SLNB is the gold standard method for detecting nodal metastasis, axillary lymph node fine-needle aspiration biopsy (FNAB) utility has not been thoroughly explored. Ultrasound-guided axillary lymph node FNAB samples along with concurrent ipsilateral breast tissue samples were searched and reviewed. The control group included histologic findings of axillary dissection or intraoperative SLNB results. A total of 354 axillary lymph node FNAB samples with matched histology were included. Of these, 187 (52.8%) were positive for metastatic carcinoma of breast origin; 143 (40.4%) were negative for metastasis; 12 (3.4%) showed atypical cells; six (1.7%) were suspicious for metastasis; and six (1.7%) were nondiagnostic because of a lack of lymphoid tissue and malignant cells. Of the 143 negative FNAB samples, 22 (15.4%) were positive on either intraoperative SLNB or ALND. When only the positive and negative FNAB samples were accounted for (n=330; 93.2%), overall diagnostic sensitivity and specificity were 89.4% and 99.2%, respectively. Although axillary SLNB is the standard procedure for detecting nodal metastasis of breast origin, axillary lymph node FNAB appears to be a suitable alternative in a significant proportion of patients. A standard SLNB should be performed in cases of negative axillary lymph node FNAB findings, particularly nodes with abnormal imaging findings.

Sensory evaluation of axillary odour samples of younger and older adults by a trained panel

AbstractIt has been reported that a distinct ‘old person smell’ can develop with advancing age, however, this odour has not yet been sufficiently described in previous research. Sensory evaluation by a trained panel might be useful to describe alterations with age in body odour (BO). To evaluate the alterations and achieve first insights into the ‘old person smell’, this pilot study determined the odour profiles of BO samples from both a younger and an older age group with a trained panel. In addition, we aimed to assess whether the panellists can recognize the age group based on the smell of the BO samples. Eight younger (20–28 years) and eight older (80–83 years) participants sampled their BO by wearing a cotton T‐shirt for one night. The samples were sensorially evaluated by a trained panel, including ratings of total intensity and pleasantness. Additionally, an age labelling task was performed as a forced‐choice decision. Results revealed that the odour profiles of the BO samples were very similar for both age groups. Nevertheless, trained panellists were able to predict the age group with significantly higher accuracy (p = .042) than expected by chance (61% mean accuracy over all panellists). Furthermore, a linear support vector machine (SVM) classifier achieved an average accuracy of 69%. This finding indicates that the age of a person affects the BO, though it is not reflected in significantly distinct odour profiles.

Pig adipose tissue of two different breeds and locations: morphology and Raman studies

According to the recent data, there are 4–5-local pig breeds left in Russia by now. Livni is among them. This breed is characterized by high fat content. Back fat has been analyzed earlier. We aimed to assess fat morphometrics from other localizations in pigs.
 Sacral, axillary, and perirenal fat samples from 6-month-old Duroc and Livni pig breeds were analyzed using morphological and Raman-based techniques.
 Livni adipocytes were characterized by dense packing with a polyhedron-like structure. In Duroc fat, they were more rounded (spherical). A “two-phase” cell disperse was identified in all samples. Fat cells in Livni pigs were bigger than those in the Duroc breed: 70–102, 15–18, and 26% for sacral, axillary, and perirenal locations. Differences in the intensity of the Raman signal between the samples were found: in the samples of subcutaneous adipose tissue, more intense peaks were observed, which are responsible for unsaturation; the samples of Livni axillary fat were characterized by greater unsaturation than sacral fat.
 Livni and Duroc adipocytes differ from each other in form and size and the difference depends on location. Pork fat from local breeds is expected to have potentially more health protecting (for animals) and health promoting (for consumers) properties.

The extent of agreement between frozen and paraffin block data from axillary samples in patients with early-stage breast cancer

IntroductionPatients with early-stage breast cancer currently undergo sentinel lymph node dissection to evaluate the axillary region. Frozen tissue blocks are evaluated intra operatively and paraffin-embedded samples are studied postoperatively. We explored whether sentinel lymph node dissection adequately reflected axillary involvement (as revealed by the paraffin blocks) in patients with early-stage breast cancer; we sought to avoid axillary dissection. MethodsThe agreement/non-agreement rates between the results of axillary ultrasonography and biopsy, sentinel lymph node and axillary dissections, and frozen and paraffin block results, were retrospectively analyzed for 200 patients with early-stage breast cancer. The positive predictive values and accuracies were recorded in those who were positive on both ultrasonography and biopsy. The negative predictive values were calculated for doubly negative cases. ResultsThe frozen and paraffin block results disagreed in 19 (9.5 %) cases and agreed in 181 (90.5 %). The frozen block and dissection results differed in five of 38 patients who underwent axillary dissection (AD) (one patient did not undergo AD); the results were in agreement in 32. Of the 19 block-disagreement cases, 16 were in the non-neoadjuvant chemotherapy (NAC) group and three in the NAC treatment group. Clinically, the negative predictive values of the frozen and paraffin block data were 80 % in patients lacking axillary involvement. ConclusionParaffin block evaluations only (thus, without frozen block examinations) of early-stage breast cancer lymph nodes seem to be sufficient to guide treatment. Also, a thorough clinical examination (with ultrasonography and axillary biopsy) reduces the dissection rate and the associated functional impairments.

Identifying SARS-COV-2 infected patients through canine olfactive detection on axillary sweat samples; study of observed sensitivities and specificities within a group of trained dogs.

There is an increasing need for rapid, reliable, non-invasive, and inexpensive mass testing methods as the global COVID-19 pandemic continues. Detection dogs could be a possible solution to identify individuals infected with SARS-CoV-2. Previous studies have shown that dogs can detect SARS-CoV-2 on sweat samples. This study aims to establish the dogs’ sensitivity (true positive rate) which measures the proportion of people with COVID-19 that are correctly identified, and specificity (true negative rate) which measures the proportion of people without COVID-19 that are correctly identified. Seven search and rescue dogs were tested using a total of 218 axillary sweat samples (62 positive and 156 negative) in olfaction cones following a randomised and double-blind protocol. Sensitivity ranged from 87% to 94%, and specificity ranged from 78% to 92%, with four dogs over 90%. These results were used to calculate the positive predictive value and negative predictive value for each dog for different infection probabilities (how likely it is for an individual to be SARS-CoV-2 positive), ranging from 10–50%. These results were compared with a reference diagnostic tool which has 95% specificity and sensitivity. Negative predictive values for six dogs ranged from ≥98% at 10% infection probability to ≥88% at 50% infection probability compared with the reference tool which ranged from 99% to 95%. Positive predictive values ranged from ≥40% at 10% infection probability to ≥80% at 50% infection probability compared with the reference tool which ranged from 68% to 95%. This study confirms previous results, suggesting that dogs could play an important role in mass-testing situations. Future challenges include optimal training methods and standardisation for large numbers of detection dogs and infrastructure supporting their deployment.

Canine Olfactory Detection of SARS-COV2-Infected Patients: A One Health Approach.

The aim of the present study is to apply the canine olfactory sensitivity to detect COVID-19-positive axillary sweat samples as a One Health approach in Latin America. One hundred volunteers with COVID-like symptoms were invited to participate, and both axillary sweat samples for dog detection and nasopharynx/oropharynx swabs for qPCR were collected. Two dogs, previously trained, detected 97.4% of the samples positive for COVID-19, including a false-negative qPCR-test, and the positive predictive value was 100% and the negative predictive value was 98.2%. Therefore, we can conclude that canine olfactory sensitivity can detect a person infected with COVID-19 through axillary sweat successfully and could be used as an alternative to screen them without invasive testing.

New method of screening for COVID-19 disease using sniffer dogs and scents from axillary sweat samples

Early screening for COVID-19 is needed to limit the spread of the virus. The aim of this study is to test if the sniffer dogs can be successfully trained to identify subjects with COVID-19 for 'proof of concept' and 'non-inferiority' against PCR. We are calling this method, Dognosis (DN). Four hundred and fifty-nine subjects were included, 256 (Group 'P') were known cases of COVID-19 (PCR positive, some with and some without symptoms) and 203 (Group 'C') were PCR negative and asymptomatic (control). Samples were obtained from the axillary sweat of each subject in a masked fashion. Two dogs trained to detect specific Volatile Organic Compounds for COVID-19 detection were used to test each sample. [DN] turned out positive (+) in all the cases that were PCR positive (100% sensitivity). On the other hand, [DN] turned positive (+) in an average of 12.5 cases (6.2%) that were initially PCR negative (apparent specificity of 93.8%). When the PCR was repeated, true specificity was 97.2%. These parameters varied in subgroups from 100% sensitivity and 99% specificity in symptomatic patients to 100% sensitivity and 93% specificity in asymptomatic patients. DN method shows high sensitivity and specificity in screening COVID-19 patients.

A breath of fresh air - the potential for COVID-19 breath diagnostics.

A breath of fresh air - the potential for COVID-19 breath diagnostics.

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.

Can the detection dog alert on COVID-19 positive persons by sniffing axillary sweat samples? A proof-of-concept study.

The aim of this proof-of-concept study was to evaluate if trained dogs could discriminate between sweat samples from symptomatic COVID-19 positive individuals (SARS-CoV-2 PCR positive) and those from asymptomatic COVID-19 negative individuals. The study was conducted at 2 sites (Paris, France, and Beirut, Lebanon), followed the same training and testing protocols, and involved six detection dogs (three explosive detection dogs, one search and rescue dog, and two colon cancer detection dogs). A total of 177 individuals were recruited for the study (95 symptomatic COVID-19 positive and 82 asymptomatic COVID-19 negative individuals) from five hospitals, and one underarm sweat sample per individual was collected. The dog training sessions lasted between one and three weeks. Once trained, the dog had to mark the COVID-19 positive sample randomly placed behind one of three or four olfactory cones (the other cones contained at least one COVID-19 negative sample and between zero and two mocks). During the testing session, a COVID-19 positive sample could be used up to a maximum of three times for one dog. The dog and its handler were both blinded to the COVID-positive sample location. The success rate per dog (i.e., the number of correct indications divided by the number of trials) ranged from 76% to 100%. The lower bound of the 95% confidence interval of the estimated success rate was most of the time higher than the success rate obtained by chance after removing the number of mocks from calculations. These results provide some evidence that detection dogs may be able to discriminate between sweat samples from symptomatic COVID-19 individuals and those from asymptomatic COVID-19 negative individuals. However, due to the limitations of this proof-of-concept study (including using some COVID-19 samples more than once and potential confounding biases), these results must be confirmed in validation studies.

Effect of “HuChou San” on ABCC11 mRNA levels and MRP8 protein expression in skin tissue from bilateral axilla of axillary osmidrosis patients

Purpose: To investigate the effect of “HuChou San” on axillary osmidrosis (AO) by measuring ABCC11 mRNA levels and MRP8 protein expression in axillary skin tissues from “HuChou San”-treated AO patients.Methods: Forty AO patients undergoing treatment at Shanghai Ninth People’s Hospital were enrolled in the study. Tissues from axillary regions were initially treated for 10 min with a solution of copper sulphate and zinc sulphate, followed by treatment with gentle application of “HuChou San” once daily for 3 months. Ten healthy individuals served as untreated control. Axillary skin tissue was surgically collected at 0, 1, 2, and 3 months of treatment. The expressions of ABCC11 mRNA and MRP8 protein in axillary skin samples were determined using qPCR and Western blot, respectively.Results: The qPCR and Western blot results showed higher levels of ABCC11 mRNA and MRP8 protein in AO patient tissues than in healthy controls. However, “HuChou San” treatment markedly reduced tissue levels of ABCC11 mRNA and MRP8 protein (p < 0.05), when compared to tissues extracted prior to treatment. These effects were time-dependent and increased as treatment duration increased (p < 0.05).Conclusion: “HuChou San” powder significantly and time-dependently reduced ABCC11 mRNA and MRP8 protein expressions in AO axillary tissue of AO patients. It is known that ABCC11 mRNA and MRP8 protein are two important indices of AO. Therefore, the findings of this study suggest that“HuChou San” has potentials for use as a novel alternative therapy for AO.
 Keywords: ABCC11 mRNA, MRP8 protein, Axillary osmidrosis, HuChou San

Comparative epidemiology and factors associated with major healthcare-associated methicillin-resistant Staphylococcus aureus clones among interconnected acute-, intermediate- and long-term healthcare facilities in Singapore

ObjectivesMethicillin-resistant Staphylococcus aureus (MRSA) has spread across countries and healthcare settings, with different clones occupying different ecological niches. It is crucial to understand the comparative epidemiology of MRSA clones between healthcare settings and independent factors associated with colonization of specific clones. MethodsWe conducted annual cross-sectional surveillance studies in a network comprising an acute-care hospital and six closely-affiliated intermediate- and long-term care facilities in Singapore between June and July, 2014–2016; 5394 patients contributed 16 045 nasal, axillary and groin samples for culture and MRSA isolates for whole-genome sequencing. Multivariable multilevel multinomial regression models were constructed to assess independent factors associated with MRSA colonization. ResultsMRSA clonal complex (CC) 22 was more prevalent in the acute-care hospital (n = 256/493; 51.9%) and intermediate-care facilities (n = 348/634; 54.9%) than in long-term care (n = 88/351; 25.1%) facilities, with clones other than CC22 and CC45 being more prevalent in long-term care facilities (n = 144/351; 41.0%) (p < 0.001). Groin colonization with CC45 was six times that of nasal colonization (aOR 6.21, 95%CI 4.26–9.01). Prior MRSA carriage was associated with increased odds of current MRSA colonization in all settings, with a stronger association with CC22 (aOR 6.45, 95%CI 3.85–10.87) than CC45 (aOR 4.15, 95%CI 2.26–7.58). ConclusionsColonization by MRSA clones differed between anatomical sites and across healthcare settings. With CC22 having a predilection for the nares and CC45 the groin, MRSA screening should include both sites. Prior MRSA carriage is a risk factor for colonization with predominant MRSA clones in the acute-care hospital and intermediate- and long-term care facilities. Contact precautions for prior MRSA carriers on admission to any healthcare facility could prevent intra- and inter-institutional MRSA transmission.

The effect of complete caloric intake restriction on human body odour quality

Previous studies on various vertebrates have shown that quantity and quality of food intake affect odour attractiveness as perceived by potential mates. In humans, the quality of body odour is similarly affected by ingested foods, such as by variation in meat and garlic intake. Nevertheless, it is not known whether quantity of food has an impact on human body odour attractiveness. Thus, here we tested how 48 h of complete caloric intake restriction affects the hedonic quality of human axillary odour.Odour samples (cotton pads fixed in both armpits and worn for 12 h) were obtained from healthy female donors across three conditions: i) during their habitual food regime; ii) after 48 h of complete caloric intake restriction (drinking water was provided), and iii) 72 h after restoration of caloric intake. Axillary samples were assessed by male raters regarding their pleasantness, attractiveness, femininity, and intensity. We also collected blood samples to assess physiological changes due to dietary restriction (e.g., glucose, sodium, albumin, and triacylglyceride assays) and anthropometric measurements at the same intervals as body odour samples.We found no differences in pleasantness, attractiveness and intensity between the odour samples collected at baseline and during complete caloric intake restriction. Interestingly, we found that body odours were rated more pleasant, more attractive and less intense after restoration of food intake as compared to the baseline and during caloric restriction. Our results suggest that restoration of food intake positively influences hedonic quality of human body odour which might thus provide cues to current fitness status and metabolic efficiency.

Initial Development toward Non-Invasive Drug Monitoring via Untargeted Mass Spectrometric Analysis of Human Skin.

Drug monitoring is crucial for providing accurate and effective care; however, current methods (e.g., blood draws) are inconvenient and unpleasant. We aim to develop a non-invasive method for the detection and monitoring of drugs via human skin. The initial development toward this aim required information about which drugs, taken orally, can be detected via the skin. Untargeted liquid chromatography-mass spectrometry (LC-MS) was used as it was unclear if drugs, known drug metabolites, or other transformation products were detectable. In accomplishing our aim, we analyzed samples obtained by swabbing the skin of 15 kidney transplant recipients in five locations (forehead, nasolabial area, axillary, backhand, and palm), bilaterally, on two different clinical visits. Untargeted LC-MS data were processed using molecular networking via the Global Natural Products Social Molecular Networking platform. Herein, we report the qualitative detection and location of drugs and drug metabolites. For example, escitalopram/citalopram and diphenhydramine, taken orally, were detected in forehead, nasolabial, and hand samples, whereas N-acetyl-sulfamethoxazole, a drug metabolite, was detected in axillary samples. In addition, chemicals associated with environmental exposure were also detected from the skin, which provides insight into the multifaceted chemical influences on our health. The proof-of-concept results presented support the finding that the LC-MS and data analysis methodology is currently capable of the qualitative assessment of the presence of drugs directly via human skin.

Human Body Odour Composites Are Not Perceived More Positively than the Individual Samples.

It is well established that composite facial images are perceived as more attractive compared with individual images, suggesting a preference for heterozygosity. Similarly, there is evidence that preferences for body odours might be linked to heterozygosity. Here, we tested whether blending individual body odours into composites would follow a similar pattern as observed in the perception of faces. We collected axillary odour samples from 38 individuals, which were subsequently assessed individually and as composites of two (N = 19) or four (N = 9) body odours regarding their pleasantness, attractiveness and intensity. We found no significant differences between mean ratings of individual odour samples or composites of two or four odour samples. Our results indicate that, in contrast to faces, composite body odours are not rated as more attractive. Composite body odours retain similar hedonic perceptual qualities as individual odours, thus highlighting differences in visual and chemosensory perceptual mechanisms.