bioRxiv Science⌕ Search

Biology subjects

Mariappan, V.

Publications and source records attributed to Mariappan, V..

2 recordsLinked to original sources

GENOMIC PROFILING OF SARS-COV-2 STRAINS CIRCULATING IN SOUTH EASTERN REGION OF INDIA DURING THREE WAVES OF PANDEMIC

Continuous bio-surveillance of SARS-CoV-2 is an ongoing task at local, national and global levels since the pandemic onset for understanding genetic evolution and vaccine efficacy. Present study was designed to track the emergence of new variants along the duration of three peaks of infection in the city of Puducherry, India. A total of 128 samples were subjected to Illumina deep RNA sequencing. The results showed predominance of uncommon, delta and omicron variants in first, second and third waves respectively. The most common pangolin lineage was B.1.560 and B.1.617.2. The study observed a total of 3133 common and 11 new mutations. The most common is in the Spike_D614G. A new set of mutations was observed in key viral factors such as NS16 that are implicated to be involved in immune evasion. This may have impact on enhanced disease virulence, vaccine efficiency and possible tolerance to current antivirals. This warrants further in vitro studies to understand the significance of the mutations. While the results presented would also augment the ongoing research on evolutionary and the genetic epidemiology of SARS-CoV-2, it also emphasizes the need for continuous genetic monitoring to predict the forthcoming threats due to the emergence of new or existing variants.

molecular biology↗

Plasma levels of Ceramides and their association with Hematocrit and Thrombocytopenia in Severe and Non-severe dengue

BackgroundPlasma leakage due to endothelial permeability is regarded as a hallmark process in the pathophysiology of severe dengue. In recent years, the importance of ceramide in regulating vascular tone during viral infection and metabolic diseases has gained attention. The present study aimed to evaluate the plasma levels of ceramide and its association with plasma leakage in dengue patients. MethodsThe study involved 30 dengue samples involving severe dengue (SD-10), Dengue with Warning sign (DWW-10), Dengue without Warning Sign (DWOW-10), along with other febrile illness (OFI-10) controls. Samples were collected on the day of admission (DOA), day of defervescence (DOD), and day of convalescence (DOC). Total plasma ceramides (d18:1/22:0) were quantified using RP-HPLC. The correlation between ceramides and hematocrit/platelet count was evaluated using Spearman Rho Correlation. All the statistical analyses were performed using SPSS software. ResultsDuring the febrile phase, a significant (P[≤]0.05) decrease in the levels of ceramides was observed in dengue compared to OFI (control). Towards the defervescences, the ceramides levels were substantially (P [≤] 0.001) elevated in dengue groups compared to baseline. Most importantly, the ceramide levels were found to be higher in SD patients compared to non-severe dengue (DWW & DWOW) and OFI, particularly at the critical phase of infection. We observed a significant negative correlation (r = -0.867, P [≤]0.001) between the platelet count and ceramide levels in SD subjects. Notably, a negative correlation was observed between ceramide and hematocrit during the defervescence phase (R = -0.355, P[≤]0.05) in the AD group. ConclusionElevated levels of circulating plasma ceramides during the defervescence phase of severe dengue show an essential role of ceramides in disease pathogenesis, however further studies are required to ascertain it.

molecular biology↗