Uptake hydrogenase in fast-growing strains of Rhizobium sp. (Sesbania) in relation to nitrogen fixation

Eight of 104 fast-growing strains of Rhizobium sp. ( Sesbania ) tested possessed a hydrogen recycling system. Depression of uptake hydrogenase occurred in poor as well as in rich carbon media. A statistically significant increase (> 22%) in total plant nitrogen content and dry matter yield was observed by the inoculation of hup + strains over hup ^- strains.     

H2-Recycling system in mungbean Rhizobium in relation to N2-fixation

Thirty isolates of mungbean Rhizobium were tested for the presence of H₂-recycling system. All the isolates were preliminary screened for detecting H₂-recycling system in free culture using triphenyltetrazolium chloride reduction as screening procedure. The isolates which reduced the dye rapidly at early stages of growth were found to recycle hydrogen both in vivo as well as in vitro. Nitrogen fixing efficiency of hydrogenase positive, hydrogenase negative isolates and Hup^– mutants was compared by green house experiments. There was 13–56% increase in dry matter and 21–46% increase in total nitrogen of the plants inoculated with H₂-recycling isolates over the plants inoculated with non-recycling isolates. There was reduction in dry matter and total nitrogen content of the plants inoculated with Hup^– mutants as compared to plants inoculated with wild type strain. The per cent decrease due to inoculation with Hup^– mutants over wild type strain was 19–22 and 20–26 of dry weight and total nitrogen in plants, respectively.Abbreviations TTC triphenyltetrazolium chloride     

Modulatory effects of metanil yellow on immunity in rodents.

Pathomorphological and immunological studies were carried out on rodents following oral administration of 0, 0.1, 0.25 and 0.5% (w/w) metanil yellow, mixed in diet, for 30 days. No significant change in hematologic parameters and histologic architecture of liver, kidney, mesenteric lymph node, thymus and urinary bladder was observed except for mild desquamation of intestinal villi and moderate changes in Peyer's patches of small intestine with higher doses. Among immunological parameters, significant enhancement in the primary humoral immune response (anti-SRBC IgM plaque forming cells of spleen) was observed with the lowest dose of metanil yellow while higher doses produced opposing effects. An elevated cutaneous delayed type hypersensitivity (DTH) reaction to SRBC was seen in 0.1% metanil yellow treated animals but higher doses did not influence the reaction. The treatment also caused changes in functional capabilities of macrophages. Although these immune alterations could hardly influence the local immunity of gut, as measured by the capacity of animals to cause rejection of Nippostrongylus brasiliensis parasite, the potential to modulate the immunity in general by metanil yellow however assumes considerable biological significance.     

Novel insights into the dynamics behavior of glucagon-like peptide-1 receptor with its small molecule agonists

Abstract

The glucagon-like peptide-1 receptor (GLP-1R) is a well-known target of therapeutics industries for the treatment of various metabolic diseases like type 2 diabetes and obesity. The structural–functional relationships of small molecule agonists and GLP-1R are yet to be understood. Therefore, an attempt was made on structurally known GLP-1R agonists (Compound 1, Compound 2, Compound A, Compound B, and (S)-8) to study their interaction with the extracellular domain of GLP-1R. In this study, we explored the dynamics, intrinsic stability, and binding mechanisms of these molecules through computational modeling, docking, molecular dynamics (MD) simulations and molecular mechanics Poisson–Boltzmann surface area (MM/PBSA) binding free energy estimation. Molecular docking study depicted that hydrophobic interaction (pi–pi stacking) plays a crucial role in maintaining the stability of the complex, which was also supported by intermolecular analysis from MD simulation study. Principal component analysis suggested that the terminal ends along with the turns/loops connecting adjacent helix and strands exhibit a comparatively higher movement of main chain atoms in most of the complexes. MM/PBSA binding free energy study revealed that non-polar solvation (van der Waals and electrostatic) energy subsidizes significantly to the total binding energy, and the polar solvation energy opposes the binding agonists to GLP-1R. Overall, we provide structural features information about GLP-1R complexes that would be conducive for the discovery of new GLP-1R agonists in the future for the treatment of various metabolic diseases.

Communicated by Ramaswamy H. Sarma     

Plant proteomics in India and Nepal: current status and challenges ahead

Plant proteomics has made tremendous contributions in understanding the complex processes of plant biology. Here, its current status in India and Nepal is discussed. Gel-based proteomics is predominantly utilized on crops and non-crops to analyze majorly abiotic (49 %) and biotic (18 %) stress, development (11 %) and post-translational modifications (7 %). Rice is the most explored system (36 %) with major focus on abiotic mainly dehydration (36 %) stress. In spite of expensive proteomics setup and scarcity of trained workforce, output in form of publications is encouraging. To boost plant proteomics in India and Nepal, researchers have discussed ground level issues among themselves and with the International Plant Proteomics Organization (INPPO) to act in priority on concerns like food security. Active collaboration may help in translating this knowledge to fruitful applications.     

Immunotoxicological effects of dermal application of scum of waste crankcase oil in mice

The scum of waste crankcase oil (SWCO) forms due to weathering of waste crankcase oil, deposited on the surface of water bodies. It is known to attach to the feathers of aquatic birds and cause toxicity to the eggs of nestling birds. The water bodies contaminated with SWCO can also be a source of toxicity to the human beings and animals entering such bodies. Since SWCO used in the present study had an appreciable content of heavy metals like Zn, Pb, Cd, Mn, Cr and Ni, the present investigation was undertaken to study a probable effect on immune system of mice. Animals treated with SWCO at a dose of 0.5, 1.0, 2.0, or 4.0 g/kg body weight for 28 days, had no effect on the weight gain of vital organs. A depressing effect was observed on the cell population of spleen and thymus. The number of primary antibody (IgM) producing cells was significantly depressed in spleen. The IgM antibody titer of serum, reduction of NBT dye by peritoneal exudat cells and mounting of delayed hypersensitivity response were not affected. In view of above immunotoxic effects of SWCO, the waste crankcase oil should be carefully disposed of, away from water bodies.     

Awareness and Attitude towards Breastfeeding among Two Generations of Indian Women: A Comparative Study

IntroductionPresent study was aimed to analyze the impact of education, employment and financial independence in breastfeeding practices among Indian women.MethodologyPresent explorative questionnaire based survey included 256 women (128 pairs) in the final analysis. A pair means – a) pregnant lady (in her third trimester) representing younger generation and b) her mother/mother in law representing the elder generation.ResultsWe found that the overall awareness regarding ‘breast milk’ being the best food for baby was excellent (overall 97.3%; younger generation: 96.9%; elder generation: 97.7%). Overall knowledge regarding the correct technique (28.9% younger generation and 21.9% elder generation) and frequency of breastfeeding (20.3% of younger generation and 34.4% of elder generation) was very poor. Less than 60% (younger generation: 57.8%; elder generation: 58.6%) were aware that the only major contraindication for breastfeeding is a mother infected with human immunodeficiency virus (HIV). On comparing responses obtained from the two generations of women, difference was not statistically significant among most of the issues related to breastfeeding. With regards to the attitude, despite better awareness, only 94.5% women in younger generation and 89.1% women in elder generation were planning to give mother’s milk as the first feed to the newborn. Similarly, less than 75% of women were ready to breast-feed the newborn immediately after birth. This was contradictory to the fact that 86% of pregnant women were aware that the baby should be breast-fed within an hour of birth.ConclusionAwareness with regards to breastfeeding issues had not changed significantly with the educational progress of Indian women. Despite the good level of awareness in the society regarding breastfeeding, attitude to practice the same is lacking.     

Impact of low doses of tritium on the marine mussel, Mytilus edulis: genotoxic effects and tissue-specific bioconcentration

Despite growing scientific, public and regulatory concern over the discharge of radioactive substances, no serious attempts have been made to develop a rationale to evaluate the impact of environmentally relevant radionuclides in the aquatic environment. In this study, we have evaluated the genotoxic effects and tissue-specific concentration of tritium (added as tritiated water, HTO) in the adult life stage of the edible mussel, Mytilus edulis. The genotoxic effects were quantified in terms of the induction of: (a) micronuclei (MN), and (b) DNA single-strand breaks/alkali-labile sites using alkaline single-cell gel electrophoresis (Comet assay) in the haemocytes of exposed animals. The assays were optimised and validated using a range of concentrations (18-56 mgl(-1)) of ethylmethane sulfonate (EMS), a direct-acting reference genotoxic agent, over different exposure periods. Mussels were exposed to a series of concentrations of HTO equivalent to a dose range from 12 to 485 muGyh(-1) for 96 h, and different tissues and organs were then extracted and analysed. The study revealed a dose-dependent increase in the response for both the MN test and the Comet assay and for both EMS and HTO. In addition, HTO delivering dose rates below 500 muGyh(-1) was shown to be capable of inducing genetic damage in the haemocytes of these bivalves. The study also showed that inorganic tritium accumulated differentially in mussel tissues in a dose-dependent manner, with the gut accumulating the highest amount of radioactivity, followed by the gill, mantle, muscle, foot and byssus thread. The faeces and pseudo-faeces accumulated least radioactivity over the exposure period. Differential accumulation of radionuclides has significant implications for biomonitoring programmes, for this and other aquatic organisms. The study also suggests that the generic dose limits recommended by the International Atomic Energy Agency for the protection of aquatic biota might not be applicable to all aquatic organisms.     

Biochemical and molecular characterization of a rhizobitoxine-producing <Emphasis Type="Italic">Bradyrhizobium</Emphasis> from pigeon pea plants

Out of a total of 8 bacterial strains isolated from the root nodules of pigeon pea plants grown in arid region, five were identified as rhizobia based on biochemical test and confirmed by 16S rDNA sequencing. PCR based screening for the rtxA gene (involved in biosynthesis of rhizobitoxine) revealed that the gene was present in one strain identified biochemically and genetically as belonging to species Bradyrhizobium (BS KT-24). The strain was resistant to phosphomycin, nalidixic acid, kanamycin, gentamicin and neomycin but sensitive towards streptomycin and spectinomycin. Bioinformatic-tool-guided phylogenetic analysis of rtxA gene revealed its distinctiveness from other known rtxA genes (present in B. japonicum, B. elkanii and Xanthomonas oryzae). The rhizobitoxine producing strain BS KT-24 is considered to exhibit better survival and nodulation protection besides competitiveness for pigeon pea and other legumes grown under abiotic stress and, thus, be a candidate in practical aspect of rhizobitoxine production by rhizobium and its application as rhizobial inoculants.