Wound age estimation is a significant issue in forensic pathology. Although various methods have been evaluated, no gold standard system or model has been proposed, and accurate injury time estimation is still challenging. The distinction between vital skin wounds-i.e., ante-mortem lesions-and skin alterations that occur after death is a crucial goal in forensic pathology. Once the vitality of the wound has been confirmed, the assessment of the post-trauma interval (PTI) is also fundamental in establishing the causal relationship between the traumatic event and death. The most frequently used techniques in research studies are biochemistry, molecular biology, and immunohistochemistry (IHC). Biochemical methods take advantage of the chemical and physical techniques. A systematic literature search of studies started on 18 February 2023. The search was conducted in the main databases for biomedical literature, i.e., PubMed and Scopus, for papers published between 1973 and 2022, focusing on different techniques of immunohistochemistry and immunofluorescence (IF) for estimating the PTI of skin wounds. The present study involves a comprehensive and structured analysis of the existing literature to provide a detailed and comprehensive overview of the different IHC techniques used to date skin lesions, synthesize the available evidence, critically evaluate the methodologies, and eventually draw meaningful conclusions about the reliability and effectiveness of the different markers that have been discovered and used in wound age estimation.

Anti-glomerular basement membrane (anti-GBM) antibody disease is a rapidly progressive glomerulonephritis characterized by (i) positivity to anti-GBM in serum reacting with a specific antigen present in type IV collagen at both the glomerular and alveolar levels (ii) presence of crescent on light microscopy and positivity to linear deposits of IgG and C3 on immunofluorescence. In the classic variant, the clinic is that of a nephro-pneumological syndrome but there are variants. Rarely, the glomerular damage is pauci-immune. We describe a case of a variant in which there is anti-MBG positivity in serum but negative immunofluorescence and offer a review of the literature and potential treatments.

BACKGROUND: Pemphigus is a group of immunobullous dermatoses characterized by the presence of autoantibodies directed against adhesion molecules of keratinocytes, with pemphigus vegetans being the rarest form, accounting for 1%-2% of all cases of pemphigus. Pemphigus vegetans is characterized by verrucous vegetative lesions in addition to vesiculobullous lesions.
METHODS: We report a rare case of pemphigus vegetans presenting as an isolated vegetative lesion in the groin 3 months prior to the development of blisters. Owing to the atypical presentation, multiple biopsies were performed before and after corticosteroid treatment.
RESULTS: Comparing the histopathology of pre-treatment and post-treatment biopsy specimens, the resolution of intraepidermal microabscesses, and reduction in intraepidermal and dermal inflammatory infiltrates, spongiosis and interface change, attributable to treatment, were noted. However, direct immunofluorescence showed persistent intracellular intraepidermal deposition of IgG and C3 2 weeks into treatment, despite near-complete resolution of blisters on clinical examination. Clinical regression of the vegetative lesion was noted only after 6 weeks into corticosteroid treatment, while histopathological evidence of treatment was apparent at the second week.
CONCLUSIONS: The current case illustrates the importance of a liberal use of immunofluorescence studies in establishing the uncommon yet significant diagnosis of pemphigus vegetans, particularly for vegetative lesions that are persistent, in the intertriginous areas and/or in the setting of concurrent cutaneous or mucosal symptoms.

Chronic ulcerative stomatitis (CUS) is a rare disease of the mucous membranes with characteristics similar to other autoimmune diseases. The aim of this study was to conduct a systematic review of the literature to recover all reported cases of CUS in order to summarize what are the clinical, demographic, microscopic, immunological features of CUS and its therapeutic response to different drugs. A systematic review of the literature was carried out following the statements of preferred reporting items for systematic reviews and meta-analyses (PRISMA). The searches were performed in the electronic databases PubMed, Scopus, EMBASE, LILACS, Opengrey, and Google scholar. Inclusion criteria were articles or abstracts reporting at least one case with a final diagnosis of CUS. A total of 696 records were identified through databases, and 25 studies were selected reporting 81 cases. CUS affects more females (92%), and a greater number of cases are reported in Caucasian patients (53%). The age of patients ranged from 20 to 86 years with a mean age of 60 years (±13.86), and 15% of cases reported concomitantly skin lesions. The clinical and histopathological characteristics of CUS are very similar to those of oral lichen planus. The direct immunofluorescence (DIF) remains the gold-standard diagnostic resource and was performed in 69 cases, revealing a dotted pattern of deposition of stratified epithelium-specific antibodies (SES-ANA). The serum of 38 patients was collected for the performance of the indirect immunofluorescence (IIF), and the use of epithelial substrates such as monkey and guinea pig esophagus often resulted in positive SES-ANA IgG. Most patients were treated with antimalarials, and the treatment of choice that proved to be effective is hydroxychloroquine (HCQ). This entity must be considered in the differential diagnosis of other autoimmune diseases, as it may be underreported.

BACKGROUND: Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection commonly affecting immunocompromised people. Diagnosis usually requires invasive techniques to obtain respiratory specimens. Minimally invasive detection tests have been proposed, but their operating characteristics are poorly described.
OBJECTIVE: To systematically review and meta-analyse the performance of minimally invasive PCP detection tests to inform diagnostic algorithms.
METHODS: Medline, Embase, Cochrane Library (inception to 15 October 2020).
METHODS: Studies of minimally invasive PCP detection tests were included if they contained a minimum of ten PCP cases.
METHODS: Adults at risk of PCP.
METHODS: Non-invasive PCP detection tests.
UNASSIGNED: Diagnosis using the combination of clinical and radiographical features with invasive sampling.
UNASSIGNED: Using the QUADAS-2 tool.
METHODS: We used bivariate and, when necessary, univariate analysis models to estimate diagnostic test sensitivity and specificity.
RESULTS: Fifty-two studies were included; most studies (40) comprised exclusively human immunodeficiency virus (HIV) -infected individuals; nine were mixed (HIV and non-HIV), two were non-HIV and one study did not report HIV status. Sampling sites included induced sputum, nasopharyngeal aspirate, oral wash and blood. The four testing modalities evaluated were cytological staining, fluorescent antibody, PCR and lactate dehydrogenase. Induced sputum had the most data available; this modality was both highly sensitive at 99% (95% CI 51%-100%) and specific at 96% (95% CI 88%-99%). Induced sputum cytological staining had moderate sensitivity at 50% (95% CI 39%-61%) and high specificity at 100% (95% CI 100%-100%), as did fluorescent antibody testing with sensitivity 74% (95% CI 62%-87%) and specificity 100% (95% CI 91%-100%).
CONCLUSIONS: There are several promising minimally invasive PCP diagnostic tests available, some of which may reduce the need for invasive respiratory sampling. Understanding the operating characteristics of these tests can augment current diagnostic strategies and help establish a more confident clinical diagnosis of PCP. Further studies in non-HIV infected populations are needed.

Diabetes mellitus is one of the foremost diseases in the modern era and diabetic nephropathy contributes to a major percentage of end-stage kidney disease. Although diabetic nephropathy is difficult to revert back, detection of nondiabetic renal disease (NDRD) is important to detect as most of them are treatable. We describe a case of a 62-year-old female with long-standing diabetes mellitus presenting with massive proteinuria and clinical features of nephrotic syndrome. The kidney biopsy showed class III diabetic nephropathy along with focal proliferative glomerulonephritis with crescent formations. The immunofluorescence study showed strong mesangial IgA deposition with the predominance of lambda stain. This confirmed the diagnosis of diabetic nephropathy with superimposed IgA nephropathy. We reviewed eight Indian studies herewith to demonstrate NDRD spectrum in the Indian diabetic scenario.

Tissue clearing technologies can greatly improve the depth and accuracy with which the three-dimensional structure of tissues, especially those of th*-e nervous system, can be visualized. A review of the present literature suggests that the growing diversity and sophistication of various approaches have contributed to the expansion of this method to a greater variety of tissue types, experimental conditions, and imaging modalities. In the proof-of-concept study presented in this paper, a simplified and modified version of the tissue clearing method CUBIC (clear, unobstructed brain imaging cocktails and computational analysis) was used in conjunction with fluorescent staining and immunohistochemistry to illustrate the three-dimensional structure and molecular characteristics of inflammatory and degenerative activity in the mouse optic nerve. Based on the studies summarized in this mini-review, and our impression from using the mCUBIC method, it appears that tissue clearing could be a viable approach revealing three-dimensional histological features of myelin-rich tissues under normal conditions and after injury.

BACKGROUND: Pemphigus erythematosus (PE) is a rare autoimmune skin condition with clinical, histopathological, and serological features that show overlap between lupus erythematosus and pemphigus foliaceus. It typically presents with erythematous, scaly plaques and has a female predominance.
METHODS: After Institutional Review Board (IRB) approval, we searched the internal pathology database for \"pemphigus erythematosus\" in the diagnostic line between 1 January 2000 and 30 July 2020. A comprehensive chart review was performed to collect patient demographics, clinical presentation, and treatment course. We performed a review of the literature and clinical, histopathological, and serological features were collected for comparison to our case series.
RESULTS: Five patients in the case series and 87 patients in the literature were diagnosed with PE. Clinical, histopathological, and serological features were consistent with what has been reported in the literature, although our cohort demonstrated a younger age at presentation, along with a higher proportion (80%) of Black patients. Of the 25 patients in the literature whose race was reported, only five patients (20%) were reported to be Black.
CONCLUSIONS: This is the first case series of PE that has shown an increased prevalence among middle-aged Black patients. No specific trend in regards to race was seen in the review of the literature.

Nucleases play crucial roles in maintaining genomic integrity. Visualization of intracellular distribution and translocation of nucleases are of great importance for understanding the in-vivo physiological functions of these enzymes and their roles in DNA repair and other cellular signaling pathways. Here we review the recently developed approaches for fluorescence imaging of nucleases in various eukaryotic cells. We mainly focused on the immunofluorescence techniques, the genetically encoded fluorescent probes and the chemically synthesized fluorescent DNA-substrate probes that enabled in-situ visualization of the subcellular localization of nucleases and their interactions with other protein/DNA molecules within cells. The targeted nucleases included important endonucleases, 3\' exonucleases and 5\' exonucleases that were involved in the DNA damage repair pathways and the intracellular DNA degradation. The advantages and limitations of the available tools were summarized and discussed.

Ectopic adrenocorticotropic hormone (ACTH) syndrome caused by paraganglioma is extremely rare. It usually accompanied by high or normal plasma ACTH level. Here we described a male who presented with ectopic ACTH-producing paraganglioma and a low plasma ACTH level. Immunohistochemistry and immunofluorescence confirmed ACTH production in focal paraganglioma cells. This unusual case expanded the spectrum of ACTH-dependent Cushing\'s syndrome and revealed a potential mechanism of this unique clinical phenotype. Besides, the literature concerning ACTH-producing paraganglioma is reviewed.