Stability indicating RP-HPLC method for simultaneous determination of gatifloxacin and dexamethasone in binary combination

Abstract In this study, conditions were optimized for development of a simple RP-HPLC method for simultaneous analysis of gatifloxacin and dexamethasone in different matrices like pharmaceuticals, human serum and urine. Good separation of gatifloxacin and dexamethasone from the induced degradation products was accomplished using C8 as stationary phase; 0.02 M phosphate buffer (pH 3.0) and methanol (42:58 v/v) as mobile phase. The concentration was measured with DAD at 270 nm. Linearity was observed in the range of 0.000040-0.000280 mol/L for gatifloxacin (r2≥0.999) and 0.000013-0.000091 mol/L for dexamethasone (r2≥0.999). Both the analyte peaks were completely separated from the peaks of induced degradation products as indicated by the peak purity index (≥0.9999 for both analytes). The optimized method is recommended to be used for concurrent analysis of gatifloxacin and dexamethasone in different matrices

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Uso de microbiota cecal congelada com crioprotetores em pintos infectados experimentalmente com Salmonella enterica sorovar Enteritidis Use of frozen cecal microbiota with cryoprotectors in chicks experimentally infected with Salmonella enterica serotype Enteritidis

Pintos de corte com um dia de idade foram tratados com microbiota cecal cultivada em condição de aerobiose, nos tempos de congelamento de 90, 200, 290 e 360 dias, e associada aos crioprotetores sacarose, trealose, dimetilsulfóxido (DMSO) e glicerol. Posteriormente as aves foram desafiadas com Salmonella Enteritidis, visando determinar a eficácia dos tratamentos em relação à quantidade de bactérias viáveis da microbiota que foi maior aos 90 dias (10,58 Log10 UFC/ml), quando as aves foram tratadas com sacarose, e menor aos 290 dias, quando tratadas com glicerol (7,73 Log10 UFC/ml). No tempo zero, todas as aves apresentaram Salmonella (100%) quando tratadas com DMSO e glicerol, com colonização cecal de 4,9 e 5,2 Log10 UFC/g do conteúdo cecal, respectivamente; aos 360 dias nenhuma ave foi infectada, independente do tratamento. A microbiota cecal, independente de tratamento, sempre determinou menor quantidade de S. Enteritidis em qualquer um dos parâmetros pesquisados, quando comparada com a das aves não tratadas. O congelamento em nitrogênio líquido foi eficaz na manutenção da viabilidade da microbiota cecal até 360 dias.<br>One-day-old broiler chicks were treated with cecal microbiota cultivated under aerobiose conditions, frozen during 90, 200, 290 and 360 days and associated with different cryoprotectors such as sucrose, trehalose, DMSO and glycerol. Subsequently, the birds were challenged with Salmonella Enteritidis in order to determine the efficacy of the different treatments in relation to the quantity of viable bacteria, which was higher at 90 days when treated with sucrose (10.58 log10 CFU/ml) and lower at 290 days when treated with glycerol (7.73 log10 CFU/ml). The quantity of infected birds was 100% in 0 time, when the cecal colonization by S. Enteritidis was 4.9 and 5.2 log10 CFU/g of cecal content, respectively treated with DMSO and glycerol. No bird was infected at 360 days, irrespectively of the treatment. In all treatments, the cecal microbiota always determined a lesser quantity of S. Enteritidis for all the studied parameters compared to non-treated birds. Frozen in liquid nitrogen was effective in maintaining the viability of cecal microbiota during the experimental period of 360 days