Membrane function alterations in erythrocytes from mood disorder patients

Objectives: To examine erythrocyte membrane functions in mood disorder patients and to establish possible diagnostic marker parameter(s).Design: Collection of blood samples from mood disorder patients and age-matched control volunteers.Preparation of erythrocyte membranes for the proposed studies.Setting: Out patients / in patients, psychiatry ward, Civil Hospital, Ahmedabad, Gujarat, India, Department of Biochemistry, Faculty of Science, M.S.University of Baroda, Vadodara, Gujarat, India.Subjects: Unipolar and bipolar subjects. Control subjects (randomly selected volunteers).Results: The most significant results were a duration dependent decrease in the TPL/CHL ratio (mole:mole),changes in both the substrate and temperature kinetics properties of AChE and elevated plasma BChE activity in the mood disorder patients.Conclusion: The results suggest that the altered lipid profiles and the TPL/CHL (mole: mole) ratio and the altered temperature-dependent activity coefficients of erythrocyte membrane AChE and elevated plasma BChE activities could serve as useful diagnostic pointers for mood disorders.Keywords:Membrane function; Erythrocytes; Mood disorderSA Psych Rev 2003;6:11-2

Lifespan Extension by Preserving Proliferative Homeostasis in Drosophila

Regenerative processes are critical to maintain tissue homeostasis in high-turnover tissues. At the same time, proliferation of stem and progenitor cells has to be carefully controlled to prevent hyper-proliferative diseases. Mechanisms that ensure this balance, thus promoting proliferative homeostasis, are expected to be critical for longevity in metazoans. The intestinal epithelium of Drosophila provides an accessible model in which to test this prediction. In aging flies, the intestinal epithelium degenerates due to over-proliferation of intestinal stem cells (ISCs) and mis-differentiation of ISC daughter cells, resulting in intestinal dysplasia. Here we show that conditions that impair tissue renewal lead to lifespan shortening, whereas genetic manipulations that improve proliferative homeostasis extend lifespan. These include reduced Insulin/IGF or Jun-N-terminal Kinase (JNK) signaling activities, as well as over-expression of stress-protective genes in somatic stem cell lineages. Interestingly, proliferative activity in aging intestinal epithelia correlates with longevity over a range of genotypes, with maximal lifespan when intestinal proliferation is reduced but not completely inhibited. Our results highlight the importance of the balance between regenerative processes and strategies to prevent hyperproliferative disorders and demonstrate that promoting proliferative homeostasis in aging metazoans is a viable strategy to extend lifespan

Genome-wide methylation is modified by caloric restriction in<i> Daphnia magna</i>

Background The degradation of epigenetic control with age is associated with progressive diseases of ageing, including cancers, immunodeficiency and diabetes. Reduced caloric intake slows the effects of ageing and age-related disease in vertebrates and invertebrates, a process potentially mediated by the impact of caloric restriction on epigenetic factors such as DNA methylation. We used whole genome bisulphite sequencing to study how DNA methylation patterns change with diet in a small invertebrate, the crustacean Daphnia magna. Daphnia show the classic response of longer life under caloric restriction (CR), and they reproduce clonally, which permits the study of epigenetic changes in the absence of genetic variation. Results Global cytosine followed by guanine (CpG) methylation was 0.7–0.9%, and there was no difference in overall methylation levels between normal and calorie restricted replicates. However, 333 differentially methylated regions (DMRs) were evident between the normally fed and CR replicates post-filtering. Of these 65% were hypomethylated in the CR group, and 35% were hypermethylated in the CR group. Conclusions Our results demonstrate an effect of CR on the genome-wide methylation profile. This adds to a growing body of research in Daphnia magna that demonstrate an epigenomic response to environmental stimuli. Specifically, gene Ontology (GO) term enrichment of genes associated with hyper and hypo-methylated DMRs showed significant enrichment for methylation and acyl-CoA dehydrogenase activity, which are linked to current understanding of their roles in CR in invertebrate model organisms

GRASSES OF UDAIPUR DISTRICT RAJASTHAN STATE INDIA

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Kinetic attributes of rat liver microsomal adenosine 5’ triphosphate phosphohydrolase (ATPase)

252-259The kinetic properties of the rat liver microsomal ATPase, with respect to Na+, K+ and ATP requirements were examined. Presence of Na+ and K+ or both hardly caused any stimulation of the enzyme activity. The Km values for Na+ and K+were substantially low (0.32 and 0.05 mM, respectively), compared to those reported for the Na+, K+ ATPases from different tissues. Substrate kinetics studies revealed that in the absence of Na+ and K+, ATP is an activator of the enzyme. The enzyme displayed increased activity with increase in the energy of activation in the absence of Na+ and K+. The activity was partially inhibited by ouabain only in the presence of Na+ and K+. The results suggest that the liver microsomal enzyme is not a Na+, K+ ATPase, but has requirement of monovalent cations for the regulation of its activity. Also, the β3 subunit of the enzyme has a Km lowering effect

Studies on kinetic properties of acid phosphatase from nuclei-free rat liver homogenate using different substrates

205-210<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">Kinetic properties of rat liver acid phosphatase were evaluated using the conventional synthetic substrates sodium beta glycerophosphate (βGP) and p-nitrophenyl phosphate (PNPP) and physiologically occurring phosphate esters of carbohydrates,vitamins and nucleotides. The extent of hydrolysis varied depending on the substrates; phosphate esters of vitamins and carbohydrates were in general poor substrates. Kinetic analysis revealed the presence of two components of the enzyme for all the substrates. Component I had low Km and low Vmax. Opposite was true for component II. The Km values were generally high for βGP, PNPP and adenosine diphosphate (ADP). Amongst the nucleotides substrates AMP showed high affinity i.e. low Km. The increase in enzyme activity in general at high substrate concentrati on seems to be due to substrate binding and positive cooperativity. AMP which showed highest affinity was inhibitory at high concentration beyond 1mM. The results suggest that in situ the nucleotides may be the preferred substrates for acid phosphatase.</span