[Monkeypox with eccrine duct involvement]. / Viruela del mono con afectación de conductos ecrinos.

Monkeypox was historically considered a zoonotic disease restricted to areas with an animal reservoir and with limited possibilities of human transmission. However, the recent increase in incidence in non-endemic areas, together with the demonstration of human transmission, has led to more attention being paid to this disease. We present the case of a 27-year-old man with cutaneous lesions and perianal ulcers, clinically suggestive of a viral disease. Monkeypox was demonstrated with PCR analysis. The histological features and differential diagnoses of monkeypox are discussed and the characteristic histopathological pattern of eccrine gland epithelium is described which, if found in an ulcerated lesion, should raise suspicion of monkeypox.

The utility of a gross dissection anatomical model for simulation-based learning in pathology.

INTRODUCTION: The examination of morphological alterations in tissues is fundamental in Pathology. Traditional training in gross dissection has several limitations, including the risk of transmissible diseases, formaldehyde exposure and limited specimen availability. We describe a teaching method using anatomical simulators. METHODS: Liquid silicone-based artisan neoplastic anatomical models were used in conjunction with clinical scenarios. Eighty-five medical students participated in a gross dissection experience and were asked to complete a feedback questionnaire. Additionally, a workshop was organized for students to compare three different teaching methods. The first one used still images (Group1-G1), the second a video explanation (Group2-G2), and the third directly observed a pathologist while grossing (Group3-G3). RESULTS: The knowledge acquisition questionnaire showed an average value of 4.4 out of 5 (1-5) (range 3.4-4.7, σ0.89). The categories 'knowledge of resection margins' and 'macroscopic diagnosis' received the highest values (4.8, σ0.11 and 4.7, σ0.32, respectively), followed by 'understanding of handling and gross examination of the surgical specimen' (4.5, σ0.49), 'prognosis' (4.3, σ0.67) and 'understanding of a tumor resection' (3.9, σ0.96) (p<0.05). Regarding teaching methods, G3 spent less time than G2 and G1 with mean times of 15'39″ (σ2'12″), 16'50″ (σ3'45″), and 17'52″ (σ2'12″), respectively (p<0.05). Gross dissection marks (0-5) showed statistically significant differences (p<0.05). G2 obtained better results (3.7;σ0.54) than G3 (3.4;σ0.94) or G1 (3.1;σ0.8). CONCLUSIONS: This preliminary study demonstrates that it is possible to implement a gross dissection simulation module at medical school and thus enable the acquisition of skills in a secure environment.

Comparison of muscle activity while using different input devices in digital pathology.

INTRODUCTION: The high prevalence of musculoskeletal disorders in pathologists, together with the current trend towards the digitization of pathology, prompted us to study the different types of input devices employed during the revision of whole slide images, in order to investigate the pattern and extent of muscle activity involved in their use. MATERIAL AND METHODS: A comparative study was made of 10 input devices (conventional and vertical mouse, three trackballs, the Ergopointer™, the Rollermouse™, an optical pen mouse, a touchpad, and the Leap Motion™). Six medical students performed a standardized circuit using a Fitts' Law based tissue array, digitized. The electrical activity of seven upper limb muscles (adductor pollicis, extensor pollicis longus, extensor digitorum, flexor digitorum, middle deltoid, upper trapezius, and middle trapezius) was measured using surface electromyography. RESULTS: Statistically significant differences in the overall electrical activity among the different input devices, both absolute values in mV as well as normalized values to the upper limb at rest, were observed (p<0.001); the Rollermouse™ (0.1027mV; 139%), Logitech M570 trackball (0.1053mV; 145%), Ergopointer™ (0.1151mV; 167%), conventional mouse (0.1251mV; 191%), and vertical mouse (0.1312mV; 205%) required less activity, while the optical pen mouse (0.1717mV; 299%), Leap Motion™ (0.1803mV; 319%), Expert Mouse trackball (0.1845mV; 329%), EIGIIS trackball (0.2442mV; 468%) and the touchpad (0.2560mV; 496%) required greater muscle mobilization. CONCLUSION: We designed a system based on Fitts' Law to compare input devices in digital pathology. Variability between compared devices and muscle activity was found. Long-term use could result in different muscular fatigue patterns. Even though the selection of an input device is a matter of personal preference, its impact on ergonomics should be considered.

Head-tracking as an interface device for image control in digital pathology: a comparative study.

BACKGROUND: Inasmuch as the conventional mouse is not an ideal input device for digital pathology, the aim of this study was to evaluate alternative systems with the goal of identifying a natural user interface (NUI) for controlling whole slide images (WSI). DESIGN: Four pathologists evaluated three webcam-based, head-tracking mouse emulators: Enable Viacam (eViacam, CREA Software), Nouse (JLG Health Solutions Inc), and Camera Mouse (CM Solutions Inc). Twenty WSI dermatopathological cases were randomly selected and examined with Image Viewer (Ventana, AZ, USA). The NASA-TLX was used to rate the perceived workload of using these systems and time was recorded. In addition, a satisfaction survey was used. RESULTS: The mean total time needed for diagnosis with Camera Mouse, eViacam, and Nouse was 18'57", 19'37" and 22'32", respectively (57/59/68seconds per case, respectively). The NASA-TLX workload score, where lower scores are better, was 42.1 for eViacam, 53.3 for Nouse and 60.62 for Camera Mouse. This correlated with the pathologists' degree of satisfaction on a scale of 1-5: 3.4 for eViacam, 3 for Nouse, and 2 for Camera Mouse (p<0.05). CONCLUSIONS: Head-tracking systems enable pathologists to control the computer cursor and virtual slides without their hands using only a webcam as an input device. - Of the three software solutions examined, eViacam seems to be the best of those evaluated in this study, followed by Nouse and, finally, Camera Mouse. - Further studies integrating other systems should be performed in conjunction with software developments to identify the ideal device for digital pathology.

A novel simulator model and standardized assessment tools for fine needle aspiration cytology training.

OBJECTIVES: Fine needle aspiration (FNA) is an invaluable diagnostic procedure for evaluation of lesions; however, acquisition of diagnostic material is dependent on the skill of the practitioner. We report a novel patient simulator for teaching the FNA procedure and structured assessment tools for educators and learners. METHODS: We created a novel simulator model for FNA training, employed a standardized teaching module, and assessed procedure utility in medical students. Groups of students completed training using a commercial version of the model, and underwent structured evaluation using an Objective Structured Assessment of Technical Skills (OSATS) form, and the Debriefing Assessment for Simulation in Healthcare (DASH) tool. RESULTS: In the initial phase, 178 students rated the training workshop between valuable and essential (4.2 on a 5-point Likert scale). In the second phase, for students evaluated with the OSATS form, the mean overall score was 33 out of 50 (range 26-43). The areas of weakness for the participants were: (a) compression after the FNA procedure, (b) completion of the informed consent, and (c) correct explanation of the procedure to the patient. For the group of students that completed the DASH questionnaire, the results were: 6.2 (assessment by students) and 6.7 (assessment by instructor) out of a maximum of 7. CONCLUSION: A realistic simulation model, in combination with a standardized training program with formal assessment methods is a valuable tool to teach FNA. We here describe a process for teaching the FNA procedure to interested educators and learners.

Lichen Planopilaris and Frontal Fibrosing Alopecia as Model Epithelial Stem Cell Diseases.

Inflammation-associated, irreversible damage to epithelial stem cells (eSCs) of the hair follicle in their immunologically privileged niche lies at the heart of scarring alopecia, which causes permanent difficult-to-treat hair loss. We propose that the two most common and closely related forms, lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA), provide excellent model diseases for studying the biology and pathology of adult human eSCs in an easily accessible human mini-organ. Emphasising the critical roles for interferon (IFN)-γ and peroxisome proliferator-activated receptor (PPAR)-γ-mediated signalling in immune privilege (IP) collapse and epithelial-mesenchymal transition (EMT) of these eSCs respectively, we argue that these pathways deserve therapeutic targeting in the future management of LPP/FFA and other eSC diseases associated with IP collapse and EMT.

An efficient method for eccrine gland isolation from human scalp.

We describe a simple and efficient method to isolate eccrine sweat glands from the human scalp. This method is inspired by the hair graft harvesting method used in hair transplantation. Based on the recently described anatomical relationship between the scalp hair follicle and the eccrine gland, we have found that scalp follicular unit grafts are an excellent eccrine gland isolation source, especially for the coiled component. In order to make the gland visible for stereoscopic microdissection, the follicular units need to be previously stained with a vital dye like methylene blue or neutral red. The simplicity and efficiency of this isolation method should encourage further research into human eccrine sweat gland function which has always been hindered by the difficulty of gland isolation.

Epithelial-to-Mesenchymal Stem Cell Transition in a Human Organ: Lessons from Lichen Planopilaris.

Epithelial-to-mesenchymal transition (EMT) is critical for embryonic development and wound healing, and occurs in fibrotic disease and carcinoma. Here, we show that EMT also occurs within the bulge, the epithelial stem cell (eSC) niche of human scalp hair follicles, during the inflammatory permanent alopecia, lichen planopilaris. We show that a molecular EMT signature can be experimentally induced in healthy human eSCs in situ by antagonizing E-cadherin, combined with transforming growth factor-ß1, epidermal growth factor, and IFN-γ administration, which to our knowledge has not been reported previously. Moreover, induction of EMT within primary human eSCs can be prevented and even partially reversed ex vivo by peroxisome proliferator-activated receptor-γ agonists, likely through suppression of the transforming growth factor-ß signaling pathway. Furthermore, we show that peroxisome proliferator-activated receptor-γ agonists also attenuates the EMT signature even in lesional lichen planopilaris hair follicles ex vivo. We introduce lichen planopilaris as a model disease for pathological EMT in human adult eSCs, report a preclinical assay for therapeutically manipulating eSC EMT within a healthy human (mini-)organ, and show that peroxisome proliferator-activated receptor-γ agonists are promising agents for suppressing and partially reversing EMT in human hair follicles eSCs ex vivo, including in lichen planopilaris.

Characterisation of cell cycle arrest and terminal differentiation in a maximally proliferative human epithelial tissue: Lessons from the human hair follicle matrix.

Human hair follicle (HF) growth and hair shaft formation require terminal differentiation-associated cell cycle arrest of highly proliferative matrix keratinocytes. However, the regulation of this complex event remains unknown. CIP/KIP family member proteins (p21CIP1, p27KIP1 and p57KIP2) regulate cell cycle progression/arrest, endoreplication, differentiation and apoptosis. Since they have not yet been adequately characterized in the human HF, we asked whether and where CIP/KIP proteins localise in the human hair matrix and pre-cortex in relation to cell cycle activity and HF-specific epithelial cell differentiation that is marked by keratin 85 (K85) protein expression. K85 expression coincided with loss or reduction in cell cycle activity markers, including in situ DNA synthesis (EdU incorporation), Ki-67, phospho-histone H3 and cyclins A and B1, affirming a post-mitotic state of pre-cortical HF keratinocytes. Expression of CIP/KIP proteins was found abundantly within the proliferative hair matrix, concomitant with a role in cell cycle checkpoint control. p21CIP1, p27KIP1 and cyclin E persisted within post-mitotic keratinocytes of the pre-cortex, whereas p57KIP2 protein decreased but became nuclear. These data imply a supportive role for CIP/KIP proteins in maintaining proliferative arrest, differentiation and anti-apoptotic pathways, promoting continuous hair bulb growth and hair shaft formation in anagen VI. Moreover, post-mitotic hair matrix regions contained cells with enlarged nuclei, and DNA in situ hybridisation showed cells that were >2N in the pre-cortex. This suggests that CIP/KIP proteins might counterbalance cyclin E to control further rounds of DNA replication in a cell population that has a propensity to become tetraploid. These data shed new light on the in situ-biography of human hair matrix keratinocytes on their path of active cell cycling, arrest and terminal differentiation, and showcase the human HF as an excellent, clinically relevant model system for cell cycle physiology research of human epithelial cells within their natural tissue habitat.

Hair follicle-containing punch grafts accelerate chronic ulcer healing: A randomized controlled trial.

BACKGROUND: A prominent role of hair follicle-derived cells in epidermal wound closure is now well established but clinical translation of basic research findings is scarce. Although skin punch grafts have been used as a therapeutic intervention to improve healing of chronic leg ulcers, they are normally harvested from nonhairy areas, thus not taking advantage of the reported role of the hair follicle as a wound-healing promoter. OBJECTIVE: We sought to substantiate the role of hair follicles in venous leg ulcer healing by transplanting hair follicle-containing versus nonhairy punch grafts. METHODS: This was a randomized controlled trial with intraindividual comparison of hair follicle scalp grafts and nonhairy skin grafts transplanted in parallel into 2 halves of the same ulcer. RESULTS: Ulcer healing measured as the average percentage reduction 18 weeks postintervention was significantly increased (P = .002) in the hair follicle group with a 75.15% (SD 23.03) ulcer area reduction compared with 33.07% (SD 46.17) in the control group (nonhairy grafts). LIMITATIONS: Sample size was small (n = 12). CONCLUSION: Autologous transplantation of terminal hair follicles by scalp punch grafts induces better healing than punch grafts harvested from nonhairy areas. Hair punch grafting is a minimally invasive surgical procedure that appears to be effective as a therapeutic tool for chronic venous leg ulcers.

Role of Human Papillomavirus in Penile Carcinomas Worldwide.

BACKGROUND: Invasive penile cancer is a rare disease with an approximately 22 000 cases per year. The incidence is higher in less developed countries, where penile cancer can account for up to 10% of cancers among men in some parts of Africa, South America, and Asia. OBJECTIVE: To describe the human papillomavirus (HPV) DNA prevalence, HPV type distribution, and detection of markers of viral activity (ie, E6*I mRNA and p16(INK4a)) in a series of invasive penile cancers and penile high-grade squamous intraepithelial lesions (HGSILs) from 25 countries. A total of 85 penile HGSILs and 1010 penile invasive cancers diagnosed from 1983 to 2011 were included. DESIGN, SETTING, AND PARTICIPANTS: After histopathologic evaluation of formalin-fixed paraffin-embedded samples, HPV DNA detection and genotyping were performed using the SPF-10/DEIA/LiPA25 system, v.1 (Laboratory Biomedical Products, Rijswijk, The Netherlands). HPV DNA-positive cases were additionally tested for oncogene E6*I mRNA and all cases for p16(INK4a) expression, a surrogate marker of oncogenic HPV activity. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: HPV DNA prevalence and type distributions were estimated. RESULTS AND LIMITATIONS: HPV DNA was detected in 33.1% of penile cancers (95% confidence interval [CI], 30.2-36.1) and in 87.1% of HGSILs (95% CI, 78.0-93.4). The warty-basaloid histologic subtype showed the highest HPV DNA prevalence. Among cancers, statistically significant differences in prevalence were observed only by geographic region and not by period or by age at diagnosis. HPV16 was the most frequent HPV type detected in both HPV-positive cancers (68.7%) and HGSILs (79.6%). HPV6 was the second most common type in invasive cancers (3.7%). The p16(INK4a) upregulation and mRNA detection in addition to HPV DNA positivity were observed in 69.3% of HGSILs, and at least one of these HPV activity markers was detected in 85.3% of cases. In penile cancers, these figures were 22.0% and 27.1%, respectively. CONCLUSIONS: About a third to a fourth of penile cancers were related to HPV when considering HPV DNA detection alone or adding an HPV activity marker, respectively. The observed HPV type distribution reinforces the potential benefit of current and new HPV vaccines in the reduction of HPV-related penile neoplastic lesions. PATIENT SUMMARY: About one-third to one-quarter of penile cancers were related to human papillomavirus (HPV). The observed HPV type distribution reinforces the potential benefit of current and new HPV vaccines to prevent HPV-related penile neoplastic lesions.

Is the eccrine gland an integral, functionally important component of the human scalp pilosebaceous unit?

The pilosebaceous unit (PSU) and the eccrine sweat gland (ESG) are classically described as completely independent skin appendages. However, careful inspection of scalp follicular units reveals that the secretory segment of the ESG spatially approximates the hair follicle in a position below the sebaceous gland and the insertion of the arrector pili muscle. Therefore, we propose here that, contrary to conventional wisdom, the PSU and the ESG should not be viewed in isolation, and may form instead, along with the arrector pili muscle and the apocrine gland (where present),one functional unit. For this, we suggest the more inclusive term of 'Hair Cluster' (HC). If confirmed, e.g. by 3D imaging techniques, the novel concept of a functional HC, whose individual components may communicate via secreted molecules and may share selected progenitor cell populations for HC repair/regeneration, has major physiological and pathological implications, which are briefly discussed.

Reflections on how wound healing-promoting effects of the hair follicle can be translated into clinical practice.

Clinicians have long reported that hair-bearing areas tend to heal more rapidly than those lacking hair follicles. In the past decade, numerous scientific studies have corroborated clinical evidence, showing a direct nexus between the human hair follicle and the wound healing process. The migration of epithelial follicular stem cells to the skin surface to help in the wound re-epithelialization and the effect of the hair cycle on the wound healing rate underline the influence of the hair follicle in the healing process. In clinical practice, non-healing wounds are pathologies of high prevalence with significant associated burden costs for the healthcare system. As the population ages, the prevalence of this pathology is expected to increase in future years. The recent advances in understanding the biology of hair follicle stem cells have created the challenges of using this newly acquired knowledge in practical therapeutic applications. Chronic leg ulcers are an example of the targeted pathologies that urgently need better therapies. In this essay, our aim is to raise interest in this question, reviewing what is known in relation to the connections between hair follicles and wound healing, and elaborating on future directions that the field might take, including implications for clinical practice.

Human epithelial hair follicle stem cells and their progeny: current state of knowledge, the widening gap in translational research and future challenges.

Epithelial hair follicle stem cells (eHFSCs) are required to generate, maintain and renew the continuously cycling hair follicle (HF), supply cells that produce the keratinized hair shaft and aid in the reepithelialization of injured skin. Therefore, their study is biologically and clinically important, from alopecia to carcinogenesis and regenerative medicine. However, human eHFSCs remain ill defined compared to their murine counterparts, and it is unclear which murine eHFSC markers really apply to the human HF. We address this by reviewing current concepts on human eHFSC biology, their immediate progeny and their molecular markers, focusing on Keratin 15 and 19, CD200, CD34, PHLDA1, and EpCAM/Ber-EP4. After delineating how human eHFSCs may be selectively targeted experimentally, we close by defining as yet unmet key challenges in human eHFSC research. The ultimate goal is to transfer emerging concepts from murine epithelial stem cell biology to human HF physiology and pathology.

Lichen planopilaris is characterized by immune privilege collapse of the hair follicle's epithelial stem cell niche.

Lichen planopilaris (LPP) is a chronic inflammatory disease of unknown pathogenesis that leads to permanent hair loss. Whilst destruction of epithelial hair follicle stem cells (eHFSCs) that reside in an immunologically protected niche of the HF epithelium, the bulge, is a likely key event in LPP pathogenesis, this remains to be demonstrated. We have tested the hypotheses that bulge immune privilege (IP) collapse and inflammation-induced eHFSC death are key components in the pathogenesis of LPP. Biopsies of lesional and non-lesional scalp skin from adult LPP patients (n = 42) were analysed by quantitative (immuno)histomorphometry, real-time quantitative polymerase chain reaction (qRT-PCR), laser capture microdissection and microarray analysis, or skin organ culture. At both the protein and transcriptional level, lesional LPP HFs showed evidence for bulge IP collapse (ie increased expression of MHC class I and II, ß2microglobulin; reduced TGFß2 and CD200 expression). This was accompanied by a Th1-biased cytotoxic T cell response (ie increased CD8(+) GranzymeB(+) T cells and CD123(+) plasmacytoid dendritic cells, with increased CXCR3 expression) and increased expression of interferon-inducible chemokines (CXCL9/10/11). Interestingly, lesional LPP eHFSCs showed both increased proliferation and apoptosis in situ. Microarray analysis revealed a loss of eHFSC signatures and increased expression of T cell activation/binding markers in active LPP, while bulge PPARγ transcription was unaltered compared to non-lesional LPP HFs. In organ culture of non-lesional LPP skin, interferon-γ (IFNγ) induced bulge IP collapse. LPP is an excellent model disease for studying and preventing immune destruction of human epithelial stem cells in situ. These novel findings raise the possibility that LPP represents an autoimmune disease in whose pathogenesis IFNγ-induced bulge IP collapse plays an important role. Therapeutically, bulge IP protection/restoration may help to better manage this highly treatment-resistant cicatricial alopecia.