Impact of obesity with impaired glucose tolerance on retinal degeneration in a rat model of metabolic syndrome.

PurposeMetabolic syndrome (MetS) is associated with several degenerative diseases, including retinal degeneration. Previously, we reported on progressive retinal degeneration in a spontaneous obese rat (WNIN/Ob) model. In this study, we investigated the additional effect of impaired glucose tolerance (IGT), an essential component of MetS, on retinal degeneration using the WNIN/GR-Ob rat model.MethodsThe retinal morphology and ultrastructure of WNIN/GR-Ob and age-matched littermate lean rats were studied by microscopy and immunohistochemistry. The retinal transcriptome of WNIN/GR-Ob was compared with the respective lean controls and with the WNIN/Ob model using microarray analysis. Expression of selected retinal marker genes was studied via real-time PCR.ResultsProgressive loss of photoreceptor cells was observed in WNIN/GR-Ob rats with an onset as early as 3 months. Similarly, thinning of the inner nuclear layer was observed from 6 months in these rats. Immunohistochemical analysis showed decreased levels of rhodopsin and postsynaptic density protein-95 (PSD-95) proteins and increased levels of glial fibrillary acidic protein (GFAP), vascular endothelial growth factor (VEGF), and calretinin in WNIN/GR-Ob rats compared with the age-matched lean controls, further supporting cellular stress/damage and retinal degeneration. The retinal transcriptome analysis indicated altered expression profiles in both the WNIN/GR-Ob and WNIN/Ob rat models compared to their respective lean controls; these pathways are associated with activation of pathways like cellular oxidative stress response, inflammation, apoptosis, and phototransduction, although the changes were more prominent in WNIN/GR-Ob than in WNIN/Ob animals.ConclusionsWNIN/GR-Ob rats with added glucose intolerance developed retinal degeneration similar to the parent line WNIN/Ob. The severity of retinal degeneration was greater in WNIN/GR-Ob rats compared to WNIN/Ob, suggesting a possible role for IGT in this model. Hence, the WNIN/GR-Ob model could be a valuable tool for investigating the impact of MetS on retinal degeneration pathology

Genetic diversity analysis using molecular marker in Terminalia chebula

Terminalia chebula is an important medicinal plant, extensively used in Ayurveda, Unani and Homoeopathic medicines. The present study was aimed to reveal its genetic diversity based on molecular markers from twelve T. chebula accessions. Molecular diversity was studied using RAPD markers. A total of 8 polymorphic primers produced 314 polymorphic bands and 195 monomorphic bands. Unweighted Pair Group Method with Arithmetic Mean (UPMGA) dendrogram divided the accessions into 2 major clusters. Accession IIHRTc2 and IIHRTc10 showed maximum genetic diversity with 55% similarity. This characterization based on molecular markers will help in identification of economically useful accessions for further crop improvement programme

Effect of Seed Priming on Seed Germination and Vigour in Fresh and Aged Seeds of Cucumber.

Seed priming (seed invigouration) has gained a lot of importance in recent times as it emerged as a most promising area of seed quality enhancement technique. Priming is a pre-sowing treatment, that involves exposure of seeds to a low external water potential that limits hydration,(controlled hydration of seed) to a level that permits pre-germinative metabolic activity to proceed, but prevents actual emergence of the radical. Fresh seeds of cucumber was artificially aged as per ISTA standards to obtain low vigour seed lots. Both high vigour (unaged) and low vigour (aged) seeds were subjected to seed priming with various chemicals (water, KH2PO4, ,K2HPO4,oxalic acid,gibberellic acid,KNO3,calcium chloride, salicylic acid) and results were compared to identify the best priming treatments. Changes in physiological ( per cent germination, total seedling length, total seedling dry weight, seedling vigour index I and II). In cucumber seed priming improved seed germination and vigour significantly over unprimed. The response of low vigour (aged) seeds to seed priming was much higher when compared to high vigour (unaged) seeds. In cucumber, among various priming chemicals tested, seed priming with KH2PO4 10-3M, K2HPO410-3M, KNO3 0.5% were found best as there was 8, 8 and 8 % more germination in high vigour seeds and 15, 15 10 % higher germination in low vigour seeds over unprimed (control).Priming with these chemicals also showed better germination per cent in both high and low vigour seeds, over hydropriming, in both the crops. Besides germination, marked increase in vigour as evident from seedling vigour index I and II was noticed due to seed priming in both the crops when compared to unprimed. In cucumber, there was 56 and 53 % higher SVI in less vigour seeds due to priming with KH2PO4 10-3M and K2HPO410-3M,respectively,compared to unprimed, with respect to SVII, the values were 73 and 62 % more due to priming with KH2PO4 10-3M and K2HPO410-3M, respectively, compared to unprimed in cucumber. Priming with chemicals appears beneficial as there was high per cent vigour when compared to priming with water (hydropriming). In cucumber, priming with KH2PO4 10-3M increased SVI by 39 and 36.7 % and SVII by 35 and 26.6 % over hydropriming

Biochemical investigations on vigour enhancement in aged seeds upon seed priming in onion

Loss in seed quality that occurs during all process, from maturation in the field to storage, leads to seed deterioration. Storage of onion seeds under ambient, hot and humid conditions is very problematic since these conditions deteriorate seed quality faster. Seed deterioration is associated with many metabolic defects that occur due to changes in enzymes and protein levels. This deterioration can be rectified to the extent possible by the technique of seed priming. The results clearly indicated that priming will restore the lost seed vigour in aged seeds due to reactivation of enzyme activity in old seeds. The germination percentage improved from 60% to 79.5% and 72.5% in GA3 and hydroprimed, respectively. Priming will also restore the lost seed vigour in aged seeds due to reactivation of proteins in old seeds and expression of these proteins in priming treatments are related to priming induced proteins in contrast to their absence in the aged seeds which are necessary for germination and longevity of seeds

Influence of seed treatment and packaging materials on seed longevity of cluster bean [Cyamopsistetra gonoloba (L.) Taub.]

An experiment was conducted to investigate the influence of packaging materials and seed treatments on storability of cluster bean under ambient conditions of Bengaluru. The experiment consisted of six treatments viz. control (T1), bavistin @ 2 g kg-1 (T2), spinosad @ 0.04 ml/kg (T3), neem leaf powder @ 1:20 ratio (T4), Acorus calamus@ 10 g kg-1 (T5) and cow dung powder @ 10 g kg-1 (T6) and three packaging materials viz., cloth bag (C1) super grain bag (C2) and poly lined cloth bag (C3). Treated seed samples were stored in three containers under ambient storage conditions up to the duration of which seeds maintain minimum seed certification standards and samples were drawn at bimonthly intervals for ascertaining the seed quality parameters. The study suggested that seed treat-ment could be useful to prolong the storage life of cluster bean seeds. The seeds treated with spinosad (0.04 ml/kg) and stored in super-grain bag were better for maintenance of higher seed quality parameters [germination (80.00%), root length (11.70 cm), shoot length (13.60 cm), mean seedling dry weight (152 mg), seedling vigour index I and II (2024&12140) and TDH activity (1.224) with low electrical conductivity (0.368 dSm-1)] up to 18 months under ambient conditions of Bengaluru (room temperature). Super-grain bag proved to be better storage container with higher seed quality attributes viz., germination (72.38 %), seedling vigour index-I (1726), total dehydrogenase activity (1.201) and other seed quality parameters compared to cloth bag. The study suggested that use of appropriate packaging material and seed treatment could be useful to prolong the storage life of cluster bean seeds

Improving access to medicines for non-communicable diseases in rural India: a mixed methods study protocol using quasi-experimental design

Exit interview tool. Exit interview tool used in baseline survey of the ATM study. (PDF 150 kb