Methods: The PDL tissue was scraped from the roots of freshly extracted teeth to enzymatically digest using collagenase. The cells were sub-cultured. Flow-cytometric analysis for the MSC surface-markers CD105, CD73, CD166, CD90, CD34, CD45 and HLA-DR was performed. To confirm the phenotype, total RNA was extracted to synthesize cDNA and which was then subjected to RT-PCR. The gene-expression for Oct4A, Sox2, NANOG and GAPDH was determined by gel-electrophoresis. To assess their multilineage potential, cells were cultured with osteogenic, chondrogenic and adipogenic medium and then stained by Alizarin-red, Alcian-blue and Oil-Red-O respectively. MSCs from the bone-marrow were processed similarly to serve as controls.

Results: The cells isolated from extracted teeth expanded successfully. On flow-cytometric analysis, the cells were positive for CD73, CD90, CD105, CD166 and negative for CD34, CD45 and HLA-DR. The PDLSCs expressed Oct4A, Sox2, and NANOG mRNA with GAPDH expression. Cells cultured in the osteogenic, chondrogenic and adipogenic media stained positive for Alizarin-red, Alcian-blue and Oil- Red-O respectively. The surface marker expression and the trilineage differentiation characteristics were comparable to those of the BMMSCs.

METHODS AND MATERIALS: A retrospective cross-sectional study involving 80 haemodialysis (HD) patients recruited from March 2020 till March 2021. Patients' information and results was retrieved and evaluated. Risk factors affecting the COVID-19 mortality were analysed using a one-way analysis of variance (ANOVA) and binary logistic regression.

RESULTS: The mean age of the patients was 54 years who were predominantly Malays (87.5%) and living in rural areas. Majority of them had comorbidities such as diabetes mellitus (71%) and hypertension (90%). The most common presentations were fever (46%) and cough (54%) with chest radiographs showing bilateral lower zone ground glass opacities (45%). A quarter of the study population were admitted to the intensive care unit, necessitating mechanical ventilation. This study found that 51% of the patients were given steroids and 45% required oxygen supplementation. The COVID-19 infection mortality among the study population was 12.5%. Simple logistic regression analysis showed that albumin, Odd Ratio, OR=0.85 (95% Confidence Interval, 95%CI: 0.73, 0.98)) and absolute lymphocyte count OR=0.08 (95%CI: 0.11, 0.56) have inverse association with COVID-19 mortality. C-reactive protein OR=1.02 (95%CI: 1.01, 1.04), lactate dehydrogenase OR=1.01 (95%CI: 1.00, 1.01), mechanical ventilation OR=17.21 (95%CI: 3.03, 97.67) and high dose steroids OR=15.71 (95%CI: 1.80, 137.42) were directly associated with COVID-19 mortality.

MATERIALS AND METHODS: In the present study, we examined the adjuvant effect of polymyxin B on the antibacterial activity of curcumin-mediated aPDT against P. aeruginosa. P. aeruginosa was treated with curcumin in the presence of 0.1-0.5 mg/L polymyxin B and irradiated by blue LED light (10 J/cm2). Bacterial cultures treated with curcumin alone served as controls. Colony forming units (CFU) were counted and the viability of P. aeruginosa was calculated after aPDT treatment. The possible underlying mechanisms for the enhanced killing effects were also explored.

RESULTS: The killing effects of curcumin-mediated aPDT against P. aeruginosa was significantly enhanced by polymyxin B (over 2-log reductions). Moreover, it was also observed that addition of polymyxin B in the curcumin-mediated aPDT led to the apparent bacterial membrane damage with increased leakage of cytoplasmic contents and extensive DNA and protein degradation.