Expansion microscopy: A revolution in diagnostic pathology.

Expansion microscopy (ExM) is a recent discovery in diagnostic pathology and microbiology that promotes a physical magnification of the tissue specimen instead of optical magnification. It not only improves the resolution of the specimen but also enhances the diagnostic precision, and permits nanoscale imaging of the specimen. Optical microscopy is routinely used in histopathology and microbiology for ages. Due to its simplicity, compatibility with different types of specimens, and ease of operation it is accepted by pathologists. ExM and its variants have been widely tested in different types of tissue specimens and microbiological specimens and yielded brilliant results.

Histopathological Changes in Oral Tissues Induced by Pesticide Poisoning: A Pilot Study.

OBJECTIVE: The present study evaluated the histopathological changes in oral tissues induced by pesticide poisoning. PATIENTS AND METHODS: This was a cross-sectional pilot study. The sample consisted of oral tissues obtained from deceased patients during autopsy. The study samples were obtained from 10 cases of ingested pesticide poisoning, and the control samples were obtained from road traffic accident cases. All the obtained samples were subjected to histopathological examinations. The changes observed in poisoning cases were compared to those in the road traffic accident cases. RESULTS: Significant degenerative changes were observed in the epithelial cells and connective tissue components, such as collagen, muscles, nerves, vasculature, adipose tissue, and salivary acini and ducts, in the poisoning cases. The oral tissues of the road traffic accident cases did not show any significant degenerative changes. CONCLUSION: The degenerative changes in the study samples can be attributed to the direct contact of the pesticide with the autopsied oral tissues when the poison was consumed. There are instances in which the entire body may not be recovered or may not be in an examinable state. In such cases, an oral autopsy could provide additional evidence for determining the cause of death in suspected poison cases.

A Large Residual Vestibular Schwannoma Following Incomplete Resection: A Case Report With Literature Review.

Vestibular schwannomas (VSs), also known as acoustic neuromas, are benign, slow-growing tumors. If not detected early or treated appropriately, these tumors can lead to complications such as pressure on adjacent intracranial structures that can affect vital functions. The present report discusses a rare case of a residual VS in a 46-year-old female patient. The patient was a known case of left-sided VS who underwent partial excision of the tumor four years ago and had complete hearing loss on the left side since then. She reported to the clinic with progressive headaches and imbalance while walking. Magnetic resonance imaging of the brain revealed a large left residual VS compressing the brainstem and cerebellum, which was completely excised, and the patient did well postoperatively. Incomplete resection of VS carries a significant risk of tumor regrowth, necessitating the importance of complete resection with periodic follow-ups.

Assessment of Oxidative Stress by the Estimation of Lipid Peroxidation Marker Malondialdehyde (MDA) in Patients with Chronic Periodontitis: A Systematic Review and Meta-Analysis.

Objective: The present systematic review and meta-analysis aimed to assess the oxidative stress-mediated lipid peroxidation end product malondialdehyde (MDA) in periodontitis using the available literature. Materials and Methods: An electronic literature search was performed for the published articles from 2000 to 2022 in PubMed (MeSH), Science Direct, Wiley Online library, and cross-reference using specific keywords. Results: The literature search identified 1,166 articles. After analyzing the abstracts of the obtained articles, the articles were excluded for the following reasons: duplicate studies (n = 395) and not relevant to the research question (n = 726). The remaining 45 articles were chosen for full-text evaluation. Finally, the present qualitative synthesis selected 34 articles that met the inclusion criteria for evaluation and removed the articles which did not meet the required criteria (n = 11). Out of these, 16 articles had coherent data for quantitative synthesis. The meta-analysis used the standardized mean differences method at a 95% confidence interval by random-effects model. The periodontitis group displayed significantly higher MDA levels (P < 0.001) in gingival crevicular fluid, saliva, and serum samples of the studies analyzed than the healthy control. Conclusion: The analyzed studies showed significantly higher MDA levels in various biological samples of patients with periodontitis, supporting the role of elevated oxidative stress and consequent lipid peroxidation in periodontitis.

In-vitro analysis on the potential use of dental pulp mesenchymal stem cells on arecoline-induced oral epithelial cells.

To assess the protective role of the secretome of dental pulp mesenchymal stem cells on arecoline-induced epithelial-mesenchymal transition and senescence on epithelial cells of the oral mucosa. Effect of varying concentrations of arecoline extract and dental pulp mesenchymal stem cell condition media (DPSC-CM) were noted on oral mucosal epithelial cells. MTT assay, Annexin V-FITC/PI assay, and the quantitative gene expressions of BCL2, PUMA, BAD, BAX, CASP3, CASP9, CASP12, TGFB1, CST3, COL1A2, COL3A1, TIMP1, TIMP2, CDH1, and CDH2 were assessed. Oral mucosal epithelial cells exposed only to the arecoline were the control. 50% and 100% DPSC-CM decreased apoptosis-related gene expression in the cells exposed with 25 µM arecoline compared to the control. 50% DPSC-CM attenuated the expression of all fibrotic genes and EMT-related genes. 20% and 100% DPSC-CM showed differential effects on fibrotic and EMT-related genes. DPSC-CM inhibited apoptosis, and attenuated expression of fibrotic and EMT-related genes on arecoline treated human oral epithelial cells.

Reviewing the role of human papillomavirus in oral cancer using the Bradford Hill criteria of causation.

Human papillomavirus is a well-established risk factor for oropharyngeal cancer, although its role in oral cancer is still debated. Inconclusive evidence of its role in oral cancer is due to conflicting data arising from methodological differences, mostly due to the use of diagnostic tests with varying sensitivity and specificity. In addition, there is a lack of experimental data linking HPV to oral cancer. Recent epidemiological studies provide data on HPV prevalence in oral squamous cell carcinoma and other potentially malignant oral disorders. Further, molecular data from in vivo and in vitro models have led to new insights into the role of human papillomavirus in oral cancer. The clinical significance of identifying HPV as an etiology for oral squamous cell carcinoma is that if proven, vaccination could be an effective prevention tool. Further, like oropharyngeal squamous cell carcinoma, prognostic differences may exist between human papillomavirus positive and negative oral squamous cell carcinoma. This manuscript reviews data from the published literature using Bradford Hill criteria of causation to assess the role of human papillomavirus in oral cancer. Due to the advancement in molecular biology, the requirements of each of the Bradford Hill criteria of causation are modified to include integrated data from both epidemiological studies and experimental studies exploring molecular carcinogenesis.