Validation of a method for diosgenin extraction from fenugreek (Trigonella foenum-graecum L.)

Background. Diosgenin is a very important plant secondary metabolite and raw material for the drug industry. Plant sources rich in diosgenin include yam (Dioscorea spp.) and fenugreek (Trigonella foenum-graecum L.). A method for diosgenin extraction from yam extracts has previously been validated, but its extraction from fenugreek plants still requires validation. In addition, all available methods require time-consuming additional purification steps. The present study was aimed at developing a low cost, less time-consuming single-step method for diosgenin extraction from fenugreek. Material and methods. This study represents a method developed for diosgenin extraction from fenugreek plants without any additional/supportive purification methods such as chromatography or thin-layer chromatography. Diosgenin yield estimation and purity analysis by HPLC method, along with accuracy and precision analysis, is presented. Results. Five different fenugreek varieties were subjected to a newly developed diosgenin extraction method, and an HPLC chromatogram showed a single peak corresponding to diosgenin. Yield was determined by the standard curve method. Limit of detection (LOD) and limit of quantification (LOQ) for the assay were found to be 0.0312 and 0.102 \u3bcg, respectively; t calculated for slope and other statistical parameters were found to be significant (P value < 0.001) for this method. Conclusion. We have developed a fast, accurate and low cost method for diosgenin extraction from fenugreek. Although the authors have studied this method only in fenugreek plants, it could be applied to the extraction of a few other plant secondary metabolites, which will help researchers to save time and effort

Elicitation of diosgenin production in Trigonella foenum-graecum (fenugreek) seedlings by methyl jasmonate

The effects of methyl jasmonate (MeJA), an elicitor of plant defense mechanisms, on the biosynthesis of diosgenin, a steroidal saponin, were investigated in six fenugreek (Trigonella foenum-graecum) varieties (Gujarat Methi-2, Kasuri-1, Kasuri-2, Pusa Early Branching, Rajasthan Methi and Maharashtra Methi-5). Treatment with 0.01% MeJA increased diosgenin levels, in 12 days old seedlings, from 0.5%-0.9% to 1.1%-1.8%. In addition, MeJA upregulated the expression of two pivotal genes of the mevalonate pathway, the metabolic route leading to diosgenin: 3-hydroxy-3-methylglutaryl-CoA reductase (HMG) and sterol-3-\u3b2-glucosyl transferase (STRL). In particular, MeJA increased the expression of HMG and STRL genes by 3.2- and 22.2-fold, respectively, in the Gujarat Methi-2 variety, and by 25.4- and 28.4-fold, respectively, in the Kasuri-2 variety. Therefore, MeJA may be considered a promising elicitor for diosgenin production by fenugreek plants

Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b

We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society

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

Papel da gastroplastia no tratamento da apnéia obstrutiva durante o sono

Gastroplastia foi realizada como forma terapêutica auxiliar para redução de peso em 4 pacientes com obesidade severa e apnéia obstrutiva durante o sono (ASO). As idades variavam de 31 a 54 anos e todos eram do sexo masculino. Em três casos a gastroplastia acompanhou-se de traqueostomia. Após a gastroplastia todos tiveram melhora da sonolência diurna e redução de peso em 16,7% a 40,9%. Avaliações polissonográficas de noite inteira realizadas no pré e pós-operatório (3-4 meses). Os registros pós-operatórios foram feitos com traqueostomia fechada e revelaram redução da freqüência das apnéias e aumento dos estágios 3, 4 e REM. Normalização dos índices de saturação arterial de oxigênio (Sa0(2)) foi constatada em três dos 4 casos. Esses dados sugerem que a gastroplastia pode ser utilizada como forma alternativa para redução de peso em casos selecionados de ASO complementando outros procedimentos cirúrgicos como a traqueostomia