Solomon F. D. Paul

ACE and MTHFR gene polymorphisms in unexplained recurrent pregnancy loss.

Aim:  To assess the association between polymorphisms in angiotensin converting enzyme and methylene tetrahydrofolate reductase genes and recurrent pregnancy loss by a case‐control study in South Indian women.

The neuroprotective role of melatonin against amyloid β peptide injected mice

Widespread cerebral deposition of a 40–42 amino acid peptide called amyloid β peptide (Aβ) in the form of amyloid fibrils is one of the most prominent neuropathologic features of Alzheimers disease (AD). The clinical study provides evidence that accumulation of protofibrils due to the Arctic mutation (E22G) causes early AD onset. Melatonin showed beneficial effects in an AD mouse model. Mice were divided into four different groups (n=8 per group): (i) control group, (ii) scrambled Aβ-injected group, (iii) Aβ protofibril-injected group and (iv) melatonin-treated group. A single dose of (5 µg) Aβ protofibril was administered to the Aβ protofibril-injected and melatonin-treated groups via intracerebroventricular injections. The results demonstrate that melatonin treatment significantly reduces Aβ protofibril-induced reactive oxygen species (ROS) production, intracellular calcium levels and acetylcholinesterase activity in the neocortex and hippocampus regions. Based on these findings it is suggested that melatonin therapy might be a useful treatment for AD patients.

Bleomycin, neocarzinostatin and ionising radiation-induced bystander effects in normal diploid human lung fibroblasts, bone marrow mesenchymal stem cells, lung adenocarcinoma cells and peripheral blood lymphocytes

Purpose: To determine whether the bystander effects induced by chemotherapeutic agents are similar to those induced by ionising radiation and to analyse the cell dependency, if any, in different human cell types such as normal lung fibroblasts (WI-38), human bone marrow mesenchymal stem cells (hBMSC), lung adenocarcinoma (A-549, NCI-H23) and peripheral blood lymphocytes (PBL). Materials and methods: The cells mentioned above were exposed to two different concentrations of bleomycin (BLM) and neocarzinostatin (NCS) and to X-irradiation. Co-culture methodology was adopted to study the in vitro bystander effects. DNA damage was measured using a micronucleus (MN) assay as an endpoint to study the bystander response. High performance liquid chromatography (HPLC) was performed to rule out any residual activity of BLM and NCS. To further investigate if this bystander response is mediated through reactive oxygen species (ROS), the bystander cells were pretreated with dimethyl sulphoxide (DMSO), an ROS scavenger, and co-cultured with cells exposed to BLM. Results: Bystander response was observed in all five types of human cells (WI-38, hBMSC, NCI-H23, A-549 and PBL) co-cultured with exposed cells. While all cell types showed a bystander response, undifferentiated hBMSC and PBL showed a higher magnitude of bystander response. A reduction in the MN frequency was observed in co-cultured hBMSC and PBL pretreated with DMSO. Conclusion: These results suggest that the chemotherapeutic agents, BLM and NCS, induce bystander response which is similar to that induced by radiation. Furthermore, it is observed that the bystander effect is independent of the cell type studied. Our results further support the involvement of ROS in mediating the bystander response induced by BLM.

GGN repeat length and GGN/CAG haplotype variations in the androgen receptor gene and prostate cancer risk in south Indian men

AbstractThe ethnic variation in the GGN and CAG microsatellites of the androgen receptor (AR) gene suggests their role in the substantial racial difference in prostate cancer risk. Hence, we performed a case-control study to assess whether GGN repeats independently or in combination with CAG repeats were associated with prostate cancer risk in South Indian men. The repeat lengths of the AR gene determined by Gene scan analysis, revealed that men with GGN repeats ≤21 had no significant risk compared to those with >21 repeats (OR 0.91 at 95% CI-0.52-1.58). However, when CAG repeats of our earlier study was combined with the GGN repeat data, the cases exhibited significantly higher frequency of the haplotypes CAG ≤19/GGN ≤21 (OR-5.2 at 95% CI-2.17-12.48, P < 0.001) and CAG ≤19/GGN > 21(OR-6.9 at 95%CI-2.85-17.01, P < 0.001) compared to the controls. No significant association was observed between GGN repeats and prostate-specific antigen levels and the age at diagnosis. Although a trend of short GGN repeats length in high-grade was observed, it was not significant (P = 0.09). Overall, our data reveals that specific GGN/CAG haplotypes (CAG ≤19/GGN ≤21 and CAG ≤19/GGN > 21) of AR gene increase the risk of prostate cancer and thus could serve as susceptibility marker for prostate cancer in South Indian men.

Cytogenetic Analysis of Patients with Primary Amenorrhea

Abstract Amenorrhea is a normal clinical feature in prepubertal, pregnant, and postmenopausal females. It also accounts for 20% of patients with infertility. The physiology of menstruation and reproduction has a strong correlation with the expression of the X chromosome. Thus, the role of genetics in terms of diagnosis, risk assessment, and genetic counseling is significant. The genetic contribution to amenorrhea is studied both at the cellular and molecular level aiming at abnormalities in chromosomes and mutations in genes. The present study aimed at performing chromosomal analysis in patients present with primary amenorrhea (n=140) employing GTG banding. The karyotype results revealed 71.2% (n=101) with normal chromosome composition and 27.8% (n=39) showed chromosomal abnormalities. In patients with abnormal chromosome constituents, 74% (n=29) exhibit numerical aberration and 26% (n=10) showed structural abnormalities. The X-chromosome abnormality was observed in 49% of the subject population which is consistent with results of studies conducted in the past. Also, the involvement of Y chromosome and origin of marker chromosome was confirmed by FISH in four patients.

Receptors and signaling mechanisms for B-lymphocyte activation, proliferation and differentiation - Insights from both in vivo and in vitro approaches

During the last three decades, a number of B‐lymphocyte specific surface antigens have been defined some of which may also show activation/differentiation specific expression. Here, we review the various signaling events and the receptor‐ligand interactions for B‐cell development, activation and differentiation. Our discussion and presentation include reviewing the in vivo and in vitro mechanisms. Focus is on the experiments that give us valuable insights into the B cell signaling mechanisms in vitro. Three significant pathways in B‐cell development – c‐Kit, FLT‐3 and IL‐7 signaling pathways are elucidated upon. Both antigen dependent and antigen independent mechanisms of B cell stimulation are also reviewed.

South Indian men with reduced CAG repeat length in the androgen receptor gene have an increased risk of prostate cancer.

AbstractThe androgen receptor (AR) gene possesses polymorphic CAG tandem repeats and the repeat length has been inversely related to the risk of prostate cancer (PCa). The distinct ethnic variation in the CAG repeat length may be correlated to differences in PCa risk in different populations. To evaluate the CAG repeat length in the AR gene and the implications for PCa, we screened 87 PCa patients and 120 control subjects from South India. The mean CAG repeat length in PCa patients was significantly smaller than that of controls (17.0 vs 20.7; P<0.001). Men with≤19 CAG repeats had a significantly increased risk of cancer compared to those with >19 CAG repeats (age-adjusted OR=7.01; 95% CI=3.52-13.94; P<0.001). However, no significant association was observed between CAG repeats and age of onset or prostate-specific antigen levels. Although there was a trend towards shorter CAG repeat length in high grades of cancer, it was not significant (P=0.085). Thus, our results suggest an association between short CAG repeats in the AR gene and PCa risk in South Indian men. Further, we propose that CAG repeats could be used as a prognostic marker for PCa diagnosis.

Longer (TA) n Repeat but Not A49T and V89L Polymorphisms in SRD5A2 Gene May Confer Prostate Cancer Risk in South Indian Men

Testosterone is converted to 5 alpha-dihydrotestosterone (DHT) by 5 alpha-reductase enzyme, which is encoded by the SRD5A2 gene. DHT is the main androgen responsible for prostate growth. We have analyzed the complete coding region of the SRD5A2 gene in 87 histologically confirmed prostate cancer (PC) patients, 40 benign prostatic hyperplasia (BPH) cases, and 96 control samples from southern parts of India. The study revealed the A49T site to be monomorphic, the V89L site to be highly polymorphic, and the (TA)(n) repeat site to be polymorphic with only 2 alleles in our populations. The distribution of V89L alleles between PC cases and controls was not significantly different; however, (TA)(9) alleles distributed differently between the 2 groups. BPH cases exhibited alleles similar to controls at all polymorphic sites. The sequencing of the whole coding region did not reveal any other known or novel polymorphism in this gene. Our study emphasizes that the (TA)(9) allele might confer certain PC risk but that A49T and V89L polymorphisms do not confer PC risk in South Indian men.

The effect of growth architecture on the induction and decay of bleomycin and X-ray-induced bystander response and genomic instability in lung adenocarcinoma cells and blood lymphocytes

Abstract Purpose: Cancer patients treated with radiomimetic drug bleomycin (BLM) have shown incidence of 7% second malignancy. Studies regarding BLM-induced genomic instability in bystander cells are scarce, and experiments with cells grown on three-dimensional (3D) cultures to mimic the in-vivo condition have never been attempted. Materials and methods: A549 and NCI-H23 (human lung adenocarcinoma) cells were grown as 3D cultures using Cytomatrix™, exposed to BLM or X-radiation and co-cultured with their respective unexposed cells. The DNA damage in direct and bystander cells were assessed by the induction of micronuclei (MN) or phosphorylated serine-15 residue in protein 53 (p53ser-15), a reflection of DNA damage, and by up-regulation of protein 21 (p21Waf1). The persistence of DNA damage was measured using MN assay and fluorescence in situ hybridization (FISH) in cancer cells and human peripheral blood lymphocytes (PBL) respectively. Results: BLM or X-irradiation induced DNA damage in both A549 and NCI-H23 cells and their respective bystander cells grown in 2D or 3D cultures. Further persistence of these damages in bystander PBL at delayed times indicated genomic instability in these cells. Conclusion: BLM-induced genomic instability in the progeny of bystander cells and their significance in therapy-induced second malignancy may not be eliminated completely.

Establishing integrated rural–urban cohorts to assess air pollution-related health effects in pregnant women, children and adults in Southern India: an overview of objectives, design and methods in the Tamil Nadu Air Pollution and Health Effects (TAPHE) study

Introduction In rapidly developing countries such as India, the ubiquity of air pollution sources in urban and rural communities often results in ambient and household exposures significantly in excess of health-based air quality guidelines. Few efforts, however, have been directed at establishing quantitative exposure–response relationships in such settings. We describe study protocols for The Tamil Nadu Air Pollution and Health Effects (TAPHE) study, which aims to examine the association between fine particulate matter (PM2.5) exposures and select maternal, child and adult health outcomes in integrated rural–urban cohorts. Methods and analyses The TAPHE study is organised into five component studies with participants drawn from a pregnant mother–child cohort and an adult cohort (n=1200 participants in each cohort). Exposures are assessed through serial measurements of 24–48 h PM2.5 area concentrations in household microenvironments together with ambient measurements and time-activity recalls, allowing exposure reconstructions. Generalised additive models will be developed to examine the association between PM2.5 exposures, maternal (birth weight), child (acute respiratory infections) and adult (chronic respiratory symptoms and lung function) health outcomes while adjusting for multiple covariates. In addition, exposure models are being developed to predict PM2.5 exposures in relation to household and community level variables as well as to explore inter-relationships between household concentrations of PM2.5 and air toxics. Finally, a bio-repository of peripheral and cord blood samples is being created to explore the role of gene–environment interactions in follow-up studies. Ethics and dissemination The study protocols have been approved by the Institutional Ethics Committee of Sri Ramachandra University, the host institution for the investigators in this study. Study results will be widely disseminated through peer-reviewed publications and scientific presentations. In addition, policy-relevant recommendations are also being planned to inform ongoing national air quality action plans concerning ambient and household air pollution.