Syntheses of immunodominant peptide regions of hepatitis C viral pathogens using PS-BDODMA resin: a single peptide derived from the conserved domain (E2/NS1) was highly effective in detecting anti-HCV antibodies.

Peptides were synthesized with very high purity and yield on a highly solvating copolymer of 1,4-butanediol dimethacrylate cross-linked polystyrene support (PS-BDODMA). The polymer was synthesized by radical aqueous suspension polymerization using toluene as the diluent and 1% polyvinyl alcohol as the suspension stabilizer. The supports were highly resistant to various chemical reagents and solvents that are frequently used in polypeptide synthesis. The peptides synthesized on this support were designed from the core (C), envelope (E1 and E2) and nonstructural protein (NS1-NS5) regions of the prototype hepatitis C viral (HCV) polyprotein, and were used to develop a peptide-based immunoassay (PBEIA) for the detection of HCV antibodies. The purity of these peptides was tested by HPLC. Peptide identity was confirmed by amino acid analysis and MALDI-TOF-MS. A single peptide chosen from a conserved area (E2/NS1) at the C-terminus of the hypervariable region (HVRI) was found to be sufficient for effective and reliable diagnosis of HCV infection in infected individuals, as well as also apparently healthy individuals. The CD spectrum of the peptide shows no preference for any ordered secondary structure. When used, peptide mixtures from various protein regions of HCV reduced the sensitivity and reliability of the diagnosis partly because of epitope masking.     

Ecological rescue of host-microbial systems under environmental change

Beneficial mutations can promote persistence via evolutionary rescue in species experiencing environmental change. However, in long-lived organisms, the pace of evolution is often too slow relative to that of environmental change for evolutionary rescue to occur. Using a spatially implicit metacommunity model, we demonstrate how interactions between slow-growing hosts and their fast-growing microbiomes can promote persistence under rapid environmental change. We show that microbial mutualists can rescue their hosts by allowing them to persist under deteriorating environmental conditions. This form of mutualist-mediated ecological rescue can be jeopardized by competitively dominant microbial cheaters, which can destabilize host population dynamics and promote the risk of stochastic extinction. However, when microbial diversity is high, (meta)community-level interactions among multiple microbial species can buffer the disruptive effect of cheaters and give rise to a more potent form of ecological rescue mediated by the entire microbiome that promotes the abundance, stability, and persistence of the host in the face of environmental change. Our results address two critical problems associated with the viability of rescue in macroorganisms: the temporal mismatch between rapid environmental change and slow organismal response and the potential disruption of rescue by microbial cheaters.     

Effects of sleep deprivation on cognitive and physical performance in university students

Sleep and Biological Rhythms - Sleep deprivation is common among university students, and has been associated with poor academic performance and physical dysfunction. However, current literature...     

Elucidation of the Flavonoid Catabolism Pathway in Pseudomonas putida PML2 by Comparative Metabolic Profiling

Flavonoids are 15-carbon plant secondary metabolites exuded in the rhizosphere that hosts several flavonoid-degrading bacteria. We studied flavonoid catabolism in a plant growth-promoting rhizobacterial strain of Pseudomonas by using a combination of biochemical and genetic approaches. Transposants carrying mini-Tn5gfp insertions were screened for flavonoid auxotrophy, and these mutant strains were found to be unable to grow in the flavonols naringenin and quercetin, while their growth in glycerol was comparable to that of the parental strain. In order to understand flavonoid catabolism, culture supernatants, whole-cell fractions, cell lysate, and cell debris of the wild-type and mutant strains were analyzed. Intermediates that accumulated intracellularly and those secreted in the medium were identified by a combination of reversed-phase high-pressure liquid chromatography and electrospray ionization-mass spectrometry. Structures of four key intermediates were confirmed by one-dimensional nuclear magnetic resonance spectroscopy. Comparative metabolic profiling of the compounds in the wild-type and mutant strains allowed us to understand the degradation events and to identify six metabolic intermediates. The first step in the pathway involves 3,3′-didehydroxylation, followed by hydrolysis and cleavage of the C-ring, leading via subsequent oxidations to the formation of protocatechuate. This is the first report on quercetin dehydroxylation in aerobic conditions leading to naringenin accumulation.     

Effect of Ethanolic Extract of Embelia Ribes on Dyslipidemia in Diabetic Rats

Diabetes mellitus has been treated orally with herbal remedies based on folk medicine since ancient times. Embelia ribes burm (Myrsinaceae), known commonly as vidanga, was used in Ayurveda for its anthelmintic activity. Ayurveda describes vidanga as pungent, causes increase in digestive fire, and cures flatulence and colic. A single study reported the antihyperglycemic activity of decoction of E. ribes in glucose-induced hyperglycemic albino rabbits. In the present study, the lipid-lowering and antioxidant potential of ethanolic extract of E. ribes burm was investigated in streptozotocin (40 mg/kg, IV, single injection)-induced diabetes in rats. Twenty days of orally feeding the extract (200 mg/kg) to diabetic rats resulted in significant (P < 0.01) decrease in blood glucose, serum total cholesterol, and triglycerides, and increase in HDLcholesterol levels when compared to pathogenic diabetic rats. Further, the extract also lowered the liver and pancreas thiobarbituric acid–reactive substances (TBARSs) values (P < 0.01) when compared to TBARS values of liver and pancreas of pathogenic diabetic rats. The results of test drug were comparable to gliclazide (25 mg/kg, orally), a standard antihyperglycemic agent. This is the first pilot study to provide biochemical evidence of potential of E. ribes in diabetic dyslipidemia.     

Advances in rice breeding,genetics and genomics

Molecular Breeding -     

Effects of Inorganic Nitrogen Availability on the Sporophytes of Acrostichum Aureum L.

Plants grown at low irradiance were fertilized with 0, 60, and 600 g m_-3 NH₄NO₃ once every fortnight. Plants treated with high N concentrations showed an increased growth, producing longer and broader fronds with larger areas, and were darker green in colour. Nitrogen also increased the content of chlorophyll (Chl) and carotenoids per leaf area unit. Different N treatments did not affect the photosynthetic efficiency of photosystem 2, as reflected by the high values of Chl fluorescence kinetics F_v/F_m, ranging between 0.81 to 0.84, and F_v/F₀ of 4.30 to 5.10. An increase in photochemical quenching (q_P), accompanied by a decrease in non-photochemical quenching (q_N), was observed in sporophytes fertilized with increased concentrations of NH₄NO₃. Nitrogen availability allowed sporophytes of Acrostichum aureum to become more established under natural condi tions. This revised version was published online in September 2006 with corrections to the Cover Date.     

Neutralizing the free radicals could alleviate the disease severity following an infection by positive strand RNA viruses

Free radical release due to oxidative stress is gaining importance in the field of viral pathogenesis. Recent studies suggest the involvement of oxidative stress and ROS levels in regulating disease virulence during RNA virus infection. Most of the RNA virus infections lead to vascular dysfunction and disease severity. However, the biology of free radicals in maintaining vascular endothelium integrity is not completely understood. In the present review, we discuss some of the common features in positive-strand RNA virus infections such as dengue and SARS-CoV-2 and suggest that anti-oxidant therapy could pave the way to develop therapeutic strategies in combating emerging and re-emerging RNA viruses.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12192-022-01269-x.