Background: Post-COVID conditions are a wide range of new, returning, or ongoing health problems people may experience four or more weeks after initial infection with COVID-19 which has shown to affect the quality of life of affected individuals Methodology: A cross- sectional study was conducted between 1st September 2021, and 28th February 2022 among 500 patients who visited Family Health Centre, Mazhuvannur, Kerala for various treatments who were already diagnosed with acute covid infection preceding 6 weeks. Results: Out of the 500 participants included in the study, 296 reported at least one post- COVID symptom. The mean age was 47.46 ± 17.20 (18–90) in which 42.57% were male and 57.43% were female. Among the 89.15 % vaccinated individuals, 55.89% availed vaccination prior to infection and 44.11 % post infection.. Most prevalent post–COVID symptoms reported were fatigue (31%), dizziness on standing (29.6%), symptoms that get worse after physical activity (25%), cough (21.4%), headache (13.4%). Out of 296 individuals, 174 patients (69.7 %) underwent treatment for post- COVID symptoms and 121 (59.1%) reported improvement on receiving treatment. Conclusion: Post COVID syndrome affects the quality of life of individuals. In the present study, it is concluded that age, habits (smoking, tobacco chewing, alcoholism) and co-morbid diseases are critical risk factor for the development of post-COVID syndrome and it also influences the post-COVID treatment outcome. Keywords - Post COVID syndrome, COVID 19

Objective: The aim of this systematic review was to explore the prognostic significance of immunohistochemical markers of epithelial-mesenchymal transition (EMT) in oral squamous cell carcinoma (OSCC). Methods: PubMed, EMBASE, and Scopus databases were thoroughly searched using various combinations of keywords, and Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were followed for analysis. Results: Database search yielded a total of 45 articles, out of which 13 articles were selected based on the inclusion and exclusion criteria. A total of 946 oral squamous cell carcinoma samples were evaluated for various immunohistochemical markers. The most commonly studied immunohistochemical marker of EMT was E-Cadherin followed by Beta-catenin, CD44, N-Cadherin, EMA, vimentin, SMA, ALDH1, cyclin D1, APC, Collagen IV and MMP 9.  A panel of transcription factors such as TWIST1, SNAI1/2, ZEB1, and ZEB2 and other genes intimately related to EMT (CDH1 and LAMC2) at the invasive tumor front of OSCC tissues were also studied. Conclusion:  The use of biomarkers like E-cadherin, EMA, and SMA might be a valuable tool for predicting patient outcomes and therapy. OSCC tissues had high levels of EMT phenotype as compared with the normal oral mucosa. This phenotype was characterized by reduced E-cadherin and β-catenin expression and overexpression of N-cadherin. CD44 immunoexpression was a significant predictor of lymph node metastasis, while ALDH1 high immunostaining was associated with angiolymphatic invasion. Co-expression of TWIST1 and ZEB2 was significantly prevalent in OSCC patients with poorer overall survival, especially in patients with no lymph node metastasis. The Snail family of zinc-finger transcription factors especially SNAI1/2 was significantly overexpressed in OSCC. The prognostic value of these biomarkers is proven and can be employed for evolving new therapeutic modalities. Keywords:  immunohistochemistry, oral squamous cell carcinoma, epithelial-mesenchymal transition