Skin Samples Research Articles

Multi-layered morphing soft structure with high-performance embedded electrothermal artificial muscles along with touch and temperature sensors

Abstract In this paper, we present a novel multilayered morphing structure, having similar topology resembling the structures found in nature to grasp delicate objects effectively as well as sense contact force and temperature. The structure consists of two actuation layers, two U-shaped cooling channel layers, piezoelectric based touch sensors and temperature sensors. Employing shape memory alloy (SMA) spring actuators for bending and twisted and coiled polymer fishing line with nichrome (TCPFL NMC) artificial muscles for antagonistic return, the soft silicone-based composite skin exhibits unique capabilities of large bidirectional movement, avoid rigid passive springs for return motion, soft grasping, safe interaction with humans, and ease fabrication. The SMA (0.38 mm wire diameter) serves as relatively fast actuating muscle and the TCPFL NMC (0.8 mm fiber diameter) as a slow actuating (considering mainly heating cycle), which was programmed/designed to mimic the fast and slow twitching muscles found in nature. Bending and return operations of skin samples of length 100 mm and thickness of 9 mm, with three different widths 20 mm, 25 mm, 30 mm, were experimentally studied. The 25 mm wide multilayered soft skin demonstrated cyclic actuation with a maximum bending angle of ∼70°, which was attributed due to the active cooling. The fluidic channels for active cooling were fabricated using 3D printed PVA tubes, casting within the silicone in a mold and subsequently dissolving in a circulating water. The study also included the integration and voltage response of mini-piezodisk sensor PIC255 having a diameter of 2 mm and thickness of 0.15 mm, which was embedded at different depths within the silicone (on the surface, 1 mm depth and 2 mm depth). The multilayered soft skin was also able to detect the temperature of the object during grasping, suggesting its potential application as a soft gripper in robotic systems.

A cost-effective protocol for single-cell RNA sequencing of human skin

IntroductionSingle-cell RNA sequencing (scRNAseq) and flow cytometry studies in skin are methodologically complex and costly, limiting their accessibility to researchers worldwide. Ideally, RNA and protein-based analyses should be performed on the same lesion to obtain more comprehensive data. However, current protocols generally focus on either scRNAseq or flow cytometry of healthy skin.MethodsWe present a novel label-free sample multiplexing strategy, building on the souporcell algorithm, which enables scRNAseq analysis of paired blood and skin samples. Additionally, we provide detailed instructions for simultaneous flow cytometry analysis from the same sample, with necessary adaptations for both healthy and inflamed skin specimens.ResultsThis tissue multiplexing strategy mitigates technical batch effects and reduces costs by 2-4 times compared to existing protocols. We also demonstrate the effects of varying enzymatic incubation durations (1, 3, and 16 hours, with and without enzyme P) on flow cytometry outcomes. Comprehensive explanations of bioinformatic demultiplexing steps and a detailed step-by-step protocol of the entire experimental procedure are included.DiscussionThe protocol outlined in this article will make scRNAseq and flow cytometry analysis of skin samples more accessible to researchers, especially those new to these techniques.

Differential Diagnosis of Irritant Versus Allergic Contact Dermatitis Based on Noninvasive Methods

Introduction: Irritant contact dermatitis (ICD) is characterized by direct injury to the epidermal cells, activating the innate immune response. Allergic contact dermatitis (ACD), in contrast, is delineated by a delayed hypersensitivity reaction of type IV. Despite the distinct etiopathogenic mechanisms underpinning each condition, the differentiation between them presents a significant diagnostic challenge. Objective: This study aims to determine whether a combination of clinical evaluation and noninvasive measurements—encompassing oxidative stress, erythema, hydration, melanin content, transepidermal water loss (TEWL), hemoglobin concentration, and skin texture and volume—can distinguish ICD from ACD. Methods: Two cohorts, each comprising 21 patients, were evaluated: one diagnosed with ICD and the other with ACD. All participants underwent biophysical and clinical assessments, along with Antera® 3D evaluations. Tape strips were utilized for skin sampling, and oxidative stress levels were measured via fluorescence assessments. Results: ICD prompts an almost immediate inflammatory reaction (peaking at 24 hours), whereas ACD incites a delayed response (72 hours). Noninvasive evaluated parameters as hemoglobin concentration, skin texture and volume, melanin content, erythema, and TEWL showed significant differences between the ICD and ACD cohorts (p < 0.05). The allergens amcinonide, nickel sulphate, cobalt chloride, budesonide, PPD, and thiuram mix were found to induce elevated levels of oxidative stress. Conclusions: The evaluation of patients with noninvasive parameters, including transepidermal water loss (TEWL), hemoglobin concentration, and skin texture and volume, could markedly aid in distinguishing irritant contact dermatitis from allergic contact dermatitis (ACD). Nevertheless, the study is constrained by a limited sample size.

Metagenomic sequencing of CRISPRs as a new marker to aid in personal identification with low-biomass samples.

The high specificity of the human skin microbiome is expected to provide a new marker for personal identification. Metagenomic sequencing of clustered regularly interspaced short palindromic repeats (CRISPRs), which we call metaCRISPR typing, was shown to achieve personal identification accurately. However, the intra-individual variability observed in previous studies, which may be due to poor DNA yields from skin samples, has resulted in non-reproducible results. Furthermore, whether metaCRISPR typing can assist in the forensic human DNA analysis of low-biomass samples, from which the information obtained is insufficient, is unknown. In the present study, we sequenced serially diluted control streptococcal CRISPRs cloned into plasmids to determine the minimum copy number required to obtain reproducible results from metaCRISPR typing. We found that at least 102 copies of CRISPRs are necessary to obtain reproducible results. We then analyzed the skin swab samples using both metaCRISPR typing and human DNA typing. When the DNA extracted from the skin swabs was diluted, no information was obtained from six out of eight samples by human DNA typing. On the other hand, beta diversity indices of spacer sequences compared with reference samples were below 0.8 for three out of six samples, for which no information was obtained from human DNA analysis, indicating that the spacers observed in these samples were similar to those in the references. These results indicate that metaCRISPR typing may contribute to the identification of individuals from whom the samples were obtained, even in cases where human DNA yields are insufficient to perform human DNA analysis.IMPORTANCEPrevious studies have developed new personal identification methods utilizing personal differences in the skin microbiome. However, intra-individual diversity of skin microbiome may preclude the application of microbiome-based personal identification. Moreover, no study has compared microbiome-based personal identification and practical human DNA analysis. Here, we revealed that the results of metaCRISPR typing, a previously developed microbiome-based personal identification method, are stable if the copy number of the marker gene is sufficient. We then analyzed the skin swab samples using both metaCRISPR typing and human DNA analysis. Our results indicate that metaCRISPR typing may provide additional information for personal identification using low-biomass samples that cannot be used for conventional human DNA analysis.

Differences in cell subsets between sun-exposed and unexposed skin: preliminary single-cell sequencing and biological analysis from a single case

IntroductionThe composition and subsets of skin cells continuously change in a dynamic manner. However, the specific microcosmic alterations of human photoaged skin, independent of chronologic aging, remain unclear and have been infrequently analyzed. This study aimed to evaluate the biological processes and mechanisms underlying cell-subgroup alterations in skin photoaging.MethodsWe utilized single-cell sequencing and biological analysis from a single case to investigate the effects of photoaging. Skin punch biopsies were taken from sun-exposed forearm skin and unexposed buttock skin from the same individual for comparative analysis.ResultsOur analysis identified 25 cell clusters and 12 skin cell types, revealing significant changes in unique gene expressions between the sun-exposed and unexposed skin samples. A comparison of cell numbers within each cluster revealed 9 dominant cell clusters in sun-exposed skin and 16 dominant cell clusters in unexposed skin. Enrichment analysis indicated that PD-L1 expression and the PD-1 checkpoint pathway were more prominent in sun-exposed skin, while MAPK, TNF-alpha, TGF-beta, and apoptosis pathways were more enriched in hair follicle cells of sun-exposed skin.DiscussionThis study reveals changes in cell components in photoaged skin from a single case and provides novel insights into cellular subpopulations and pathology during repeated UVA-induced skin damage. These findings enhance our understanding of the complex interplay between different cells in photoaged skin and offer potential targets for preventing human skin photoaging and UV-induced skin cancers.

Combined Analysis of Second- and Third-Generation Transcriptome Sequencing for Gene Characteristics and Identification of Key Splicing Variants in Wound Healing of Ganxi Goat Skin

Ganxi goat is a local breed of goat unique to Jiangxi Province, China, named for its primary distribution in the Ganxi region. Ganxi goats are primarily raised through grazing, showing good adaptation to the local humid and hot climate, strong disease resistance, and occupying an important position in the local livestock industry. The skin, as the main barrier of the body, plays an indispensable role in resisting the invasion of external pathogenic factors and has received increasing attention in the medical and scientific fields. In this study, Ganxi goat skin was used as the research subject. Full-length transcriptome sequencing of Ganxi goat skin was performed using PacBio third-generation sequencing technology to supplement and improve the annotation information of the Ganxi goat genome. A combined analysis of second- and third-generation transcriptome sequencing was used to analyze the splicing variant events of hub genes (CDC20, MMP2, TIMP1, and EDN1) and the expression changes in each splicing variant in skin samples on day 0 and day 5 after surgical wounding. The regulatory role of related hub gene splicing variants in wound healing was analyzed. A total of 926,667 full-length non-chimeric sequences were obtained, optimizing the annotation information of 3794 genomic gene loci and identifying 2834 new genes, 256 new LncRNAs, 12,283 alternative splicing events, 549 genes with polyadenylation, and 112 fusion genes. Three splicing variant forms were identified in both the CDC20 and EDN1 genes, seven in MMP2, and two in TIMP1. The expression levels of most splicing variants showed significant changes in the skin samples on days 0 and 5 after wounding, potentially participating in the regulation of wound healing. This study provides fundamental data for the annotation of the goat genome and offers a reference for studying the regulatory mechanisms of wound healing.

In Situ Expression of TNF-α and IL-10 in Human Dermatophytosis Lesions due to Trichophyton rubrum.

Dermatophytosis is a very common superficial mycosis, but there are few studies about the human immune response to dermatophytes. We aim to analyze the in situ expression of TNF-α and IL-10 in human dermatophytosis. Expression of TNF-α and IL-10 were evaluated in skin samples from 10 patients with dermatophytosis and 12 healthy subjects using an immunohistochemistry assay. TNF-α and IL-10 were significantly elevated in lesions from patients with dermatophytosis compared to healthy controls. These data illustrate the balance of pro- and anti-inflammatory cytokines suggesting Trichophyton rubrum infection could control the local immune response.

The emergence of multidrug-resistant Proteus vulgaris infection in cage reared Pangasianodon hypophthalmus: Molecular characterization and host-pathogen response

The study investigates the causative agent responsible for massive mortality in Pangasianodon hypophthalmus cage farms. The infected pangasius were lethargic, not taking feed, and had exophthalmia, deep ulceration, and hemorrhage on the ventral body surface. Pathogens were isolated from infected pangasius tissue samples, and the strain was preliminarily identified as Proteus vulgaris based on morphology, biochemical tests, 16S rRNA PCR sequencing, and phylogenetic analysis. The microbiological analysis revealed that P. vulgaris was associated with the disease outbreak and mortality of P. hypophthalmus, as confirmed by the biofilm formation, swimming activity, and survival assay results. The isolated P. vulgaris was resistant to several antibiotics, including Doxycycline, Dicloxacillin, Polymyxin B, Chloramphenicol, and Imipenem, exhibiting multiple antibiotic-resistant phenotypes. Furthermore, a host-pathogen model was developed to investigate the in vivo effect of emerging P. vulgaris infection in striped catfish. Results showed that P. vulgaris infection exhibited varying degrees of cellular changes in the kidney, liver, and gill tissues of infected P. hypophthalmus samples. The transcription analysis further highlights that P. vulgaris modulates the antioxidants, immune activation, growth regulator, homeostasis, degradation of invading DNA, and DNA damage-related gene expression in liver, kidney, spleen, skin, and gill tissue samples of infected P. hypophthalmus. The lessons learned from the study could be critical in understanding the P. vulgaris infection patterns and pathobiology necessary to enable risk assessment and develop management measures to control the bacterium's virulence.

NLRP10 maintains epidermal homeostasis by promoting keratinocyte survival and P63-dependent differentiation and barrier function

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder characterized by disrupted epidermal barrier function and aberrant immune responses. Despite recent developments in new therapeutics for AD, there is still a large unmet medical need for disease management due to the complex and multifactorial nature of AD. Recent genome-wide association studies (GWAS) have identified NLRP10 as a susceptible gene for AD but the physiological role of NLRP10 in skin homeostasis and AD remains unknown. Here we show that NLRP10 is downregulated in AD skin samples. Using an air-lift human skin equivalent culture, we demonstrate that NLRP10 promotes keratinocyte survival and is required for epidermal differentiation and barrier function. Mechanistically, NLRP10 limits cell death by preventing the recruitment of caspase-8 to the death inducing signaling complex (DISC) and by inhibiting its subsequent activation. NLRP10 also stabilizes p63, the master regulator of keratinocyte differentiation, to drive proper keratinocyte differentiation and to reinforce the barrier function. Our findings underscore NLRP10 as a key player in atopic dermatitis pathogenesis, highlighting NLRP10 as a potential target for therapeutic intervention to restore skin barrier function and homeostasis in AD.

Antibacterial and wound healing potential of biosynthesized zinc oxide nanoparticles against carbapenem-resistant Acinetobacter baumannii: an in vitro and in vivo study

Carbapenem-resistant Acinetobacter baumannii denotes a significant menace to public health, and it mandates an urgent development of new effective medications. Here, we aimed to estimate the efficiency of the zinc oxide nanoparticles (ZnO NP) biosynthesized from Arthrospira maxima (Spirulina) both in vitro and in vivo. Carbapenem-resistant A. baumannii isolates were collected, identified, tested for their antibiotic susceptibility, and then subjected to PCR to detect carbapenemase-producing genes. The most predominant carbapenemase resistance gene was blaKPC. The biosynthesized ZnO NP were characterized using UV, FTIR, XRD, SEM, and TEM. The prepared ZnO NP was then tested against A. baumannii isolates to determine the minimum inhibitory concentration (MIC), which ranged from 250 to 1000 μg/ml. Burn wound was persuaded in twenty rats and inoculated with carbapenem-resistant A. baumannii isolate. Rats were allocated into four groups: a negative control group, a positive control group treated with topical 0.9% saline, a test treatment group that received topical ZnO NP, and a standard treatment group. All groups received treatment for 15 consecutive days and then euthanized. Skin samples were harvested and then subjected to histopathological and immunochemical investigations. ZnO NP revealed a comparable antibacterial activity to colistin as it revealed a lower level of fibrosis, mature surface epithelization with keratinization, and restoration of the normal skin architecture. In addition, it significantly decreased the immunoreactivity of the studied inflammatory markers. Thus, ZnO NP synthesized by A. maxima could be considered a promising, safe, and biocompatible alternative to traditional antibiotics in the therapy of carbapenem-resistant A. baumannii infections.

Schistosomiasis-Microbiota Interactions: A Systematic Review and Meta-Analysis.

Schistosomiasis, a tropical disease affecting humans and animals, affected 251.4 million people in 2021. Schistosoma mansoni, S. haematobium, S. intercalatum, and S. japonicum are primary human schistosomes, causing tissue damage, granulomas, ulceration, hemorrhage, and opportunistic pathogen entry. The gut and urinary tract microbiota significantly impact a host's susceptibility to schistosomiasis, disrupting microbial balance; however, this relationship is not well understood. This systematic review and meta-analysis explores the intricate relationship between schistosomiasis and the host's microbiota, providing crucial insights into disease pathogenesis and management. This systematic review used PRISMA guidelines to identify peer-reviewed articles on schistosomiasis and its interactions with the host microbiome, using multiple databases and Google Scholar, providing a robust dataset for analysis. The study utilized Meta-Mar v3.5.1; descriptive tests, random-effects models, and subgroups were analyzed for the interaction between Schistosomiasis and the microbiome. Forest plots, Cochran's Q test, and Higgins' inconsistency statistic (I2) were used to assess heterogeneity. The human Schistosoma species were observed to be associated with various bacterial species isolated from blood, stool, urine, sputum, skin, and vaginal or cervical samples. A meta-analysis of the interaction between schistosomiasis and the host microbiome, based on 31 studies, showed 29,784 observations and 5871 events. The pooled estimates indicated a significant association between schistosomiasis and changes in the microbiome of infected individuals. There was considerable heterogeneity with variance effect sizes (p < 0.0001). Subgroup analysis of Schistosoma species demonstrated that S. haematobium was the most significant contributor to the overall heterogeneity, accounting for 62.1% (p < 0.01). S. mansoni contributed 13.0% (p = 0.02), and the coinfection of S. haematobium and S. mansoni accounted for 16.8% of the heterogeneity (p < 0.01), contributing to the variability seen in the pooled analysis. Similarly, praziquantel treatment (RR = 1.68, 95% CI: 1.07-2.64) showed high heterogeneity (Chi2 = 71.42, df = 11, p < 0.01) and also indicated that Schistosoma infections in males (RR = 1.46, 95% CI: 0.00 to 551.30) and females (RR = 2.09, 95% CI: 0.24 to 18.31) have a higher risk of altering the host microbiome. Schistosomiasis significantly disrupts the host microbiota across various bodily sites, leading to increased susceptibility to different bacterial taxa such as E. coli, Klebsiella, Proteus, Pseudomonas, Salmonella, Staphylococcus, Streptococcus, and Mycobacterium species (M. tuberculosis and M. leprae). This disruption enables these bacteria to produce toxic metabolites, which in turn cause inflammation and facilitate the progression of disease. The impact of schistosomiasis on the vaginal microbiome underscores the necessity for gender-specific approaches to treatment and prevention. Effective management of female genital schistosomiasis (FGS) requires addressing both the parasitic infection and the resulting microbiome imbalances. Additionally, praziquantel-treated individuals have different microbiome compositions compared to individuals with no praziquantel treatment. This suggests that combining praziquantel treatment with probiotics could potentially decrease the disease severity caused by an altered microbiome.

Defensive Behavior and Integumentary Morphology of the Hairy Dwarf Porcupine Coendou spinosus (Rodentia: Erethizontidae).

New World porcupines (Erethizontidae) exhibit behaviors and possess integumentary structures, including the quills, that are used for self-defense. The North American porcupine (Erethizon dorsatum) has been well studied regarding these features; however, information is lacking for the South American Coendou species. We describe the defensive behavior and integumentary morphology of Coendou spinosus to understand the defensive strategies of this species and to compare with those reported for other species. We assessed the behaviors related to warning, defense, and escape of eight porcupines, as well as the characteristics of their pelage and quills. Furthermore, we microscopically analyzed skin samples of a roadkill adult male specimen. Similar to E. dorsatum, C. spinosus exhibited omnidirectional quill erection, revealing an aposematic color and, with their backs toward the perceived human threat, they performed quick tail and body movements to strike the hands of the human trying to capture them by the tail. Furthermore, C. spinosus presented an integumentary structure similar to that of E. dorsatum, and mechanisms to facilitate quill release when touched, penetration, and fixation in the opponent. The most distinct warning behavior noted was the vibration of the quills, which has not been reported for Erethizon. Our study confirms that, like other erethizontids, C. spinosus does not attack but exhibits warning, defense, and escape mechanisms and behaviors when threatened or touched. The dissemination of such information helps to counter the negative stigma associated with porcupines, as they can be the victims of attacks by dogs and humans, and to promote their conservation.

Microneedle created in skin in situ forming gels depot; an alternate approach to the sustained transdermal delivery of colchicine

Colchicine (CLC) is a commonly used medication in prevention and treatment of acute gout condition via oral route. However its oral administrations pose several gastrointestinal (GI) adverse effects. In current study, an alternate combinatorial approach of microneedles patch and in skin forming gel depots were evaluated for sustained CLC delivery through skin using CLC loaded non-ionic amphiphilic triblock pluronic-127 thermoresponsive poloxamers. In first phase, to validate the development of in situ forming depots, the phase transition of pluronic-127 from the sol-gel state was examined using AR2000 rheometer. In second phase, microneedles patches (MAPs) were fabricated via casting method utilizing (19 × 19) laser-engineered silicone micromoulds from varied biocompatible polymer blends such as Gantrez S-97, Poly-vinyl alcohol, Polyethelene glycol 10000 and Poly (vinylpyrollidone) at various concentrations. For optimized MAPs, the mechanical strength, in skin dissolution kinetics and moisture contents were determined. From mechanical testing PVP and PVA MAPs showed more brittle nature and highest loss of MAPs reduction in comparison to Gantrez® MAPs. Optimized MAPs (Gantrez®) based on high mechanical strength were utilized as a microporation source in rabbit skin. In comparison to PVA and PVP, Gantrez® MAPs showed slow dissolution kinetics and resist dissolution for 540 s. Optical coherence tomography (OCT) quantified the penetration depth of Gantrez® MAPs in newborn rabbit skin at 591 μm. Increased in TEWL values after Gantrez® MAPs treatment confirmed the pores formation in skin. Ex-vivo permeation analysis showed that 25 % w/w CLC loaded PF127® gel showed controlled and prolonged drug permeation across microporated skin for 84 h in comparison to untreated skin. The distribution of PF127 gel solution in treated skin samples was confirmed by tracking fluorescence using confocal microscopy. Results shows that MAPs created in skin micropores can be used as CLC depots and sustained effects can be achieved by successfully avoiding oral route and GI adverse effects.

Phosphatidylserine Topically Attenuates Imiquimod-induced Psoriasis Through Inflammation Inhibition in Mice.

Psoriasis is a chronic skin condition that is associated with persistent inflammation and skin lesions. Topical therapy has been a promising approach to the alleviation of psoriasis through the application of anti-inflammatory agents. Phosphatidylserine (PS) administration has shown anti-inflammatory effects in the trials. Consequently, the objective of this study was to evaluate the effects of topical PS on the potential improvement of an imiquimod (IMQ)-induced psoriasis model. Additionally, cyclosporine A was utilized as a comparative anti-psoriatic agent in our study. The psoriasis model was established by topically applying IMQ to the dorsal skin of mice once daily for five consecutive days. The efficacy of topical PS was assessed using the Psoriasis Area and Severity Index (PASI) score to evaluate skin lesions. Subsequently, the skin samples were analyzed using Baker's scoring system, Masson's trichrome staining, immunohistochemistry, and real-time PCR analysis. IMQ-induced plaque-type psoriasis resulted in a significant increase (P<0.05) in dermal thickness, hyperkeratosis, PASI score, and inflammatory cytokines at the lesion site. The topical PS and cyclosporine A significantly (P<0.05) reduced PASI score and dermal thickness, while also alleviating erythema and scaling when compared to untreated mice. Furthermore, biomolecular assessments revealed that PS significantly (P<0.05) inhibited the gene expression of IL-17, IL-23, and TNF-α cytokines in the IMQ-induced lesions. Topical PS may pointedly alleviate psoriasis through the inhibition of inflammation. The beneficial effects of the PS recommend further investigation in both experimental and clinical studies in the control of skin psoriasis.

Impact of Dupilumab on Skin Surface Lipid-RNA Profile in Severe Asthmatic Patients.

The analysis of skin surface lipid-RNAs (SSL-RNAs) provides a non-invasive method for understanding the molecular pathology of atopic dermatitis (AD), but its relevance to asthma remains uncertain. Although dupilumab, a biologic drug approved for both asthma and AD, has shown efficacy in improving symptoms for both conditions, its impact on SSL-RNAs is unclear. This study aimed to investigate the impact of dupilumab treatment on SSL-RNA profiles in patients with severe asthma. An SSL-RNA analysis was performed before and after administering dupilumab to asthma patients requiring this intervention. Skin samples were collected non-invasively from patients before and after one year of dupilumab treatment. Although 26 patients were enrolled, an SSL-RNA analysis was feasible in only 7 due to collection challenges. After dupilumab treatment, improvements were observed in asthma symptoms, exacerbation rates, and lung function parameters. Serum levels of total IgE and periostin decreased. The SSL-RNA analysis revealed the differential expression of 218 genes, indicating significant down-regulation of immune responses, particularly those associated with type 2 inflammation, suggesting potential improvement in epithelial barrier function. Dupilumab treatment may not only impact type 2 inflammation but also facilitate the normalization of the skin. Further studies are necessary to fully explore the potential of SSL-RNA analysis as a non-invasive biomarker for evaluating treatment response in asthma.

Anti-Shrinkage Technique for Feline Skin Samples

Surgical resection of subcutaneous neoplasms with clear margins is crucial for preventing local recurrence and avoiding adjuvant treatments. However, the evaluation of surgical margins often differs significantly from the histopathological assessment due to tissue shrinkage, which can result in inaccurate therapeutic assessments and unreliable patient prognoses. In this study, ten feline cadavers were utilized. Six 50 mm diameter specimens were collected from three regions (thorax, flank, femur) and measured at three time points: T0 (excision time), T1 (10 min after incision), and T2 (at least 48 h after sample collection and formalin fixation). Samples in the study group were stretched and fixed on a cork plate with pinpoint needles after excision to restore their original dimensions. All specimens exhibited a similar trend. After 48 h of formalin fixation, the control specimens showed significant shrinkage, with a reduction of 25.73% in radius and 26.32% in diameter. In contrast, the study specimens demonstrated minimal changes, with a radius reduction of −0.28% and no change in diameter. The results indicate that all feline skin specimens experienced significant shrinkage of approximately one-quarter from their pre-incisional size. Stretching and pinning the excised tissues allowed for the restoration and maintenance of original dimensions even after formalin fixation. This technique represents a valid and practical approach to minimize tissue shrinkage.

Multisite Skin Biopsies vs Cerebrospinal Fluid for Prion Seeding Activity in the Diagnosis of Prion Diseases

Recent studies have revealed that autopsy skin samples from cadavers with prion diseases (PRDs) exhibited a positive prion seeding activity similar to cerebrospinal fluid (CSF). It is worthwhile to validate the findings with a large number of biopsy skin samples and compare the clinical value of prion seeding activity between skin biopsies and concurrent CSF specimens. To compare the prion seeding activity of skin biopsies and CSF samples and to determine the effectiveness of combination of the skin biopsies from multiple sites and numerous dilutions on the diagnosis for various types of PRDs. In the exploratory cohort, patients were enrolled from September 15, 2021, to December 15, 2023, and were followed up every 3 months until April 2024. The confirmatory cohort enrolled patients from December 16, 2023, to June 31, 2024. The exploratory cohort was conducted at a single center, the neurology department at Xuanwu Hospital. The confirmatory cohort was a multicenter study involving 4 hospitals in China. Participants included those diagnosed with probable sporadic Creutzfeldt-Jakob disease or genetically confirmed PRDs. Patients with uncertain diagnoses or those lost to follow-up were excluded. All patients with PRDs underwent skin sampling at 3 sites (the near-ear area, upper arm, lower back, and inner thigh), and a portion of them had CSF samples taken simultaneously. In the confirmatory cohort, a single skin biopsy site and CSF samples were simultaneously collected from a portion of patients with PRDs. The skin and CSF prion seeding activity was assessed using the real-time quaking-induced conversion (RT-QUIC) assay, with rHaPrP90-231, a Syrian hamster recombinant prion protein, as the substrate. In the exploratory cohort, skin samples were tested at dilutions of 10-2 through 10-4. In the confirmatory cohort, skin samples were tested at a dilution of 10-2. A total of four 15-μL wells of CSF were used in the RT-QUIC assay. Correlations between RT-QUIC results from the skin and CSF and the final diagnosis of enrolled patients. In the exploratory cohort, the study included 101 patients (mean [SD] age, 60.9 [10.2] years; 63 female [62.4%]) with PRD and 23 patients (mean [SD] age, 63.4 [9.1] years; 13 female [56.5%]) without PRD. A total of 94 patients had CSF samples taken simultaneously with the skin biopsy samples. In the confirmatory cohort, a single skin biopsy site and CSF sample were taken simultaneously in 43 patients with PRDs. Using an experimental condition of 10-2 dilution, the RT-QUIC positive rates of skin samples from different sites were comparable with those of the CSF (skin: 18 of 26 [69.2%] to 74 of 93 [79.6%] vs CSF: 71 of 94 [75.5%]). When tested at 3 different dilutions, all skin sample positivity rates increased to over 80.0% (79 of 93 for the near-ear area, 21 of 26 for the upper arm, 77 of 92 for the lower back, and 78 of 92 for the inner thigh). Combining samples from skin sites near the ear, inner thigh, and lower back in pairs yielded positivity rates exceeding 92.1% (93 of 101), significantly higher than CSF alone (71 of 94 [75.5%]; P =.002). When all skin sample sites were combined and tested at 3 dilution concentrations for RT-QUIC, the sensitivity reached 95.0% (96 of 101). In the confirmatory cohort, the RT-QUIC positive rate of a single skin biopsy sample was slightly higher than that of the CSF (34 of 43 [79.1%] vs 31 of 43 [72.1%]; P = .45). Results of this diagnostic study suggest that the sensitivity of an RT-QUIC analysis of a combination of 2 or more skin sites was superior to that of CSF in diagnosing PRDs.

Immunohistochemical examination of immunoreactivity of transient receptor potential melastatin 2, glutathione peroxidase 4 and spexin in lichen planus.

In this study, we aimed to investigate the potential contributions to the disease by examining the immunoreactivities of SPX in LP-affected skin tissue using immunohistochemical methods, in light of its recent prominence as a molecule related to diabetes mellitus, along with apoptosis and ferroptosis mediated by GPX4 and TRPM2 channels facilitating oxidative stress-induced cell death. This research explored the immunohistochemical expressions of TRPM2, GPX4, and SPX in Lichen Planus (LP) patients compared to healthy individuals. Forty skin samples were collected, split equally between LP patients and healthy controls, excluding those with other conditions. Samples underwent immunohistochemical staining for TRPM2, SPX, and GPX4, using secondary antibodies and chromogens AEC or DAB. Histoscores were calculated based on staining diffusiveness and severity. Statistical analyses were performed with SPSS 22.0, using t-tests and ANOVA, with significance set at p < 0.05. There were no demographic differences between groups (p > 0.05). LP patients showed significantly lower TRPM2 and GPX4 histoscores and higher SPX histoscores compared to controls (TRPM2 and GPX4: p < 0.001, SPX: p < 0.001). Gender and age did not affect histoscores significantly. Findings suggest TRPM2, GPX4, and SPX play roles in LP pathogenesis, indicating a need for further molecular studies to clarify their involvement. This contributes to understanding LP beyond the traditional apoptosis perspective.

Retrospective Investigation of the Utility of Potassium Hydroxide Smear in the Diagnosis and Management of Cutaneous Fungal Infections by Dermatologists

Abstract Background: Superficial cutaneous fungal infections are common dermatologic conditions. A significant proportion do not present with typical clinical findings. However, the 10% potassium hydroxide (KOH) smear, a simple bedside test, is often underused when diagnosing cutaneous fungal infections. Aims: We aimed to evaluate whether KOH smear results altered dermatologists’ diagnosis and management, and the factors that influenced its ability to detect cutaneous fungal infections. Methods: A total of 373 patients with suspected cutaneous fungal infection were identified retrospectively from the dermatology database of inpatient referrals in a Singapore tertiary hospital between 1 January 2017 and 30 June 2020. The dermatologists’ eventual diagnoses, based on their assessment until 2 months post-discharge to allow consideration of KOH smear results and response to treatment, were taken as a gold standard. Statistical analyses evaluated for changes between initial and eventual diagnoses and management relative to the KOH smear. Use of topical steroids, topical and/or systemic antifungals before skin sampling, and whether sampling was done by dermatologically-trained personnel, were assessed for association with KOH smear positivity in eventually diagnosed cases. Results: The percentage of uncertain diagnoses was reduced, and the use of topical antifungal as the sole treatment significantly changed after the KOH smear result was available. The adjusted odds ratio of a positive KOH smear in eventually diagnosed cases was 0.19 when systemic antifungals were used before skin sampling, and 3.03 if sampling was performed by a dermatologically-trained person. Limitations: Limitations of our study include dependence on retrospective medical records which may result in misclassification bias and the limited generalisability of our results to patients managed by non-dermatologists. Conclusions: KOH smear is a useful adjunct in diagnosing and managing cutaneous fungal infections. Clinicians should consider the presence of confounders affecting KOH smears when making an overall clinical diagnosis. Focused training of personnel on skin sample collection may improve the detection rate of KOH smear.

Decoding skin mysteries: Unveiling the link between microbiota and keloid scars through a Mendelian randomization study.

The cause of keloids remains unclear, but studies suggest a link between skin microbiota and keloid formation. However, the causal relationship has not been confirmed. This study utilized Genome-Wide Association Studies (GWAS) data from 2 population-based German cohorts, comprising a total of 1656 skin samples. To bolster the reliability of our results, we incorporated GWAS data from 3 keloid cohorts, encompassing 2555 patients and 870,556 controls (GWAS ID: keloid1, ebi-a-GCST90018874; keloid2, bbj-a-131; keloid3, ebi-a-GCST90018654). Subsequently, we employed bidirectional 2-sample Mendelian randomization (MR) analysis to probe the causal relationship between the variables. The primary method employed was the inverse-variance weighted (IVW) method, supported by heterogeneity analysis, horizontal pleiotropy testing, outlier detection, and "leave-one-out" sensitivity analysis. By synthesizing the results from 3 groups of MR analyses, we discovered a negative causal association between a.ASV063 [Finegoldia (unc.)] located on the volar forearm and keloid disease (IVW (keloid1) odds ratio (OR): 0.939, 95% confidence interval (CI): 0.886-0.994, P = .032; IVW (keloid2) OR: 0.897, 95% CI: 0.813-0.990, P = .031; IVW (keloid3) OR: 0.900, 95% CI: 0.825-0.981, P = .017). Similarly, a negative causal relationship may also exist between the genus: Bacteroides from the antecubital fossa and keloid disease (IVW (keloid1) OR: 0.928, 95% CI: 0.884-0.973, P = .002; IVW (keloid2) OR: 0.891, 95% CI: 0.820-0.968, P = .007; IVW (keloid3) OR: 0.918, 95% CI: 0.849-0.992, P = .030). Additionally, no reverse causation was found, with all analyses showing no signs of horizontal pleiotropy or heterogeneity. This study offers new insights for the prevention and treatment of keloids.