Characterization of structural and functional role of selenocysteine in selenoprotein H and its impact on DNA binding.

Selenoproteins are a group of proteins which contain selenocysteine (Sec or U) in their primary structure. Selenoproteins play a critical role in antioxidant defense, hormone metabolism, immune responses and muscle development. The selenoprotein H (SELENOH) is essential in the regulation of gene expression in response to redox status and antioxidant defense. It has Sec residue located in conserved CXXU motif similar to other selenoproteins. However, exact biological function of Sec residue in SELENOH is not known in detail. Therefore, it is essential to understand the structural and functional role of Sec in SELENOH. In the present study, homology modelling and MD simulation were performed to understand the role of Sec residue in SELENOH. The modelled 3D structure of wild-SELENOH along with two mutants (Mut-U44C and Mut-41CS-SC44) was subjected to MD simulation. Based on simulation results, we demonstrate that wild-SELENOH structure is dynamically stabilized by network of intramolecular hydrogen bonding and internal residue contacts facilitated by Sec residue. In contrast, notable differences have been observed in residue contacts and stability in other two mutant structures. Additionally, docking studies revealed that 3PRGRKRK9 motif of wild-SELENOH interacts with HSE and STRE of DNA molecule as observed experimentally. Similar to earlier reports, our sequence analysis study pinpoints conserved 3PRGRKRK9 motif present in SELENOH perform dual role as AT-hook motif and NLS. Overall, the obtained results clearly illustrate Sec residue plays an important role to restore functionally active conformation of SELENOH. The present study broadened our current understanding regarding the role of selenocysteine in protein structure and function.

Bio/chemoinformatics in India: an outlook.

With the advent of significant establishment and development of Internet facilities and computational infrastructure, an overview on bio/chemoinformatics is presented along with its multidisciplinary facts, promises and challenges. The Government of India has paved the way for more profound research in biological field with the use of computational facilities and schemes/projects to collaborate with scientists from different disciplines. Simultaneously, the growth of available biomedical data has provided fresh insight into the nature of redundant and compensatory data. Today, bioinformatics research in India is characterized by a powerful grid computing systems, great variety of biological questions addressed and the close collaborations between scientists and clinicians, with a full spectrum of focuses ranging from database building and methods development to biological discoveries. In fact, this outlook provides a resourceful platform highlighting the funding agencies, institutes and industries working in this direction, which would certainly be of great help to students seeking their career in bioinformatics. Thus, in short, this review highlights the current bio/chemoinformatics trend, educations, status, diverse applicability and demands for further development.

Putative DNA modification methylase DR_C0020 of Deinococcus radiodurans is an atypical SAM dependent C-5 cytosine DNA methylase.

BACKGROUND: Control of cellular processes by epigenetic modification of cytosine in DNA is widespread among living organisms, but, is hitherto unknown in the extremely radioresistant microbe D. radiodurans. METHODS: C-5 methyl cytosines (m5C) were detected by immuno-blotting with m5C-specific antibody. Site of cytosine methylation by DR_C0020 encoded protein was investigated by bisulfite sequencing. The DR_C0020 knockout mutant (Δdcm), constructed by site directed mutagenesis, was assessed for effect on growth, radiation resistance and proteome. Proteins were identified by mass spectrometry. RESULTS: Methylated cytosines were detected in the D. radiodurans genome. The DR_C0020 encoded protein (Dcm, NCBI accession: WP_034351354.1), whose amino acid sequence resembles m4C methylases, was shown to be the lone SAM-dependent C-5 cytosine methyltransferase. Purified Dcm protein was found to methylate CpN sequence with a preference for methylation of two consecutive cytosines. The Δdcm strain completely lost m5C modification from its genome, had no effect on growth but became radiation sensitive. The Δdcm cells exhibited minor alterations in the abundance of several proteins involved primarily in protein homeostasis, oxidative stress defense, metabolism, etc. CONCLUSION: DR_C0020 encoded SAM-dependent methyltransferase Dcm is solely responsible for C-5cytosine methylation at CpN sites in the genome of D. radiodurans and regulates protein homeostasis under normal growth conditions. The protein is an unusual case of an amino methyltransferase that has evolved to producing m5C. GENERAL SIGNIFICANCE: Although, dispensable under optimal growth conditions, the presence of m5C may be important for recognition of parent strand and, thus, could contribute to the extraordinary DNA repair in D. radiodurans.

Presence of DNA methyltransferase activity and CpC methylation in Drosophila melanogaster.

Drosophila melanogaster lacks DNMT1/DNMT3 based methylation machinery. Despite recent reports confirming the presence of low DNA methylation in Drosophila; little is known about the methyltransferase. Therefore, in this study, we have aimed to investigate the possible functioning of DNA methyltransferase in Drosophila. The 14 K oligo microarray slide was incubated with native cell extract from adult Drosophila to check the presence of the methyltransferase activity. After incubation under appropriate conditions, the methylated oligo sequences were identified by the binding of anti 5-methylcytosine monoclonal antibody. The antibody bound to the methylated oligos was detected using Cy3 labeled secondary antibody. Methylation sensitive restriction enzyme mediated PCR was used to assess the methylation at a few selected loci identified on the array. It could be seen that a few of the total oligos got methylated under the assay conditions. Analysis of methylated oligo sequences provides evidence for the presence of de novo methyltransferase activity and allows identification of its sequence specificity in adult Drosophila. With the help of methylation sensitive enzymes we could detect presence of CpC methylation in the selected genomic regions. This study reports presence of an active DNA methyltransferase in adult Drosophila, which exhibits sequence specificity confirmed by presence of asymmetric methylation at corresponding sites in the genomic DNA. It also provides an innovative approach to investigate methylation specificity of a native methyltransferase.

Culturable bacterial flora associated with the dinoflagellate green Noctiluca miliaris during active and declining bloom phases in the Northern Arabian Sea.

A massive algal bloom of the dinoflagellate Noctiluca miliaris (green) was located in the Northern Arabian Sea by IRS-P4-2 (OCM-II) for microbiological studies, during two consecutive cruises of February-March 2009. Culturable bacterial load during bloom were ≈ 2-3-fold higher in comparison to non-bloom waters and ranged from 3.20 × 10(5) to 6.84 × 10(5) cfu ml(-1). An analysis of the dominant heterotrophs associated with Noctiluca bloom resulted in phylogenetic and a detailed metabolic characterization of 70 bacterial isolates from an overlapping active and declining bloom phase location near north-central Arabian Sea. The active phase flora was dominated by Gram-positive forms (70.59 %), a majority of which belonged to Bacillus (35.29 %) of Firmicutes. As the bloom declined, Gram-negative forms (61.11 %) emerged dominant, and these belonged to a diverse γ-proteobacterial population consisting of Shewanella (16.67 %) and equal fractions of a Cobetia-Pseudomonas-Psychrobacter-Halomonas population (36.11 %). A Unifrac-based principal coordinate analysis of partial 16S rDNA sequences showed significant differences among the active and declining phase flora and also with reported endocytic flora of Noctiluca (red). A nonparametric multidimensional scaling (NMDS) of antibiogram helped differentiation among closely related strains. The organic matter synthesized by N. miliaris appears to be quickly utilized and remineralized as seen from the high efficiency of isolates to metabolize various complex and simple C/N substrates such as carbohydrates, proteins/amino acids, lipids, sulfide production from organic matter, and solubilize phosphates. The ability of a large fraction of these strains (50-41.67 %) to further aerobically denitrify indicates their potential for nitrogen removal from these high-organic microniches of the Noctiluca bloom in the Arabian Sea, also known for high denitrification activity. The results indicate that culturable euphotic bacterial associates of Noctiluca are likely to play a critical role in the biogeochemical ramifications of these unique seasonally emerging tropical open-water blooms of the Northern Arabian Sea.

An immunochemical method for detection and analysis of changes in methylome.

DNA methylation is an important epigenetic modification involved in the ability of an organism to respond to stress and adaptation. It has been implicated in development, differentiation, oncogenesis, chromatin remodelling, nutrigenomics, and appears to play a pivotal role in many regulatory and adaptive functions. It is therefore important to analyze the status of DNA methylation and its changes under various developmental, carcinogenic, pharmacological, and environmental conditions. In this report we describe an immunochemical method for the detection of genome wide DNA methylation and its alterations under various conditions along with the analysis of DNA methyltransferase activity. The ability of this approach to detect and provide a map of methylomic changes in a genome facilitates assessment of various agents and conditions which can alter this important epigenetic signal. This experimental system permits rapid evaluation of potential target genes which would be modulated by DNA methylation changes and thus the gene networks that govern the processes.

Genome-wide lone strand adenine methylation in Deinococcus radiodurans R1: Regulation of gene expression through DR0643-dependent adenine methylation.

DNA methylation is a covalent modification of adenine or cytosine in the genome of an organism and is found in diverse microbes including the radiation resistant bacterium Deinococcus radiodurans R1. Although earlier findings have confirmed repression or de-repression of certain genes in adenine methyltransferase (DR_0643/Dam1DR) deficient D. radiodurans mutant however, the overall regulatory aspects of Dam1DR-mediated adenine methylation remain mostly unexplored. In the present study, we compared the genome-wide methylome and the corresponding transcriptome of D. radiodurans WT and Δdam1 mutant to explore the correlation between methylation and gene expression. In D. radiodurans, deletion of DR_0643 ORF (Δdam1) led to hypomethylation of 512 genes resulting in differential expression of 168 genes (99 genes are upregulated and 69 genes are downregulated). The modification patterns deduced for Dam1DR (DR_0643) and Dam2DR (DR_2267) were non-palindromic and atypical. Moreover, we observed methylation at opportunistic sites that show adenine methylation only in D. radiodurans Δdam1 and not in D. radiodurans WT. Correlation between the methylome and transcriptome suggests that hypomethylation at Dam1DR specific sites had both negative as well as a positive effects on gene expression. Pathways such as amino acid metabolism, transport, oxidative phosphorylation, quorum sensing, signal transduction, two-component system, glycolysis/gluconeogenesis, TCA cycle, glyoxylate and dicarboxylate metabolism were modulated by Dam1DR-mediated adenine methylation in D. radiodurans. Processes such as DNA repair, recombination, ATPase and transmembrane transporter activity were enriched when Dam1DR mutant was subjected to radiation stress. We further evaluated the molecular interactions and mode of binding between Dam1DR protein and S-adenosyl methionine using molecular docking followed by MD simulation. To get a better insight into the methylation mechanism, the Dam1DR-SAM complex was also docked with a DNA molecule to elucidate DNA-Dam1DR structural interaction during methyl-group transfer reaction. In summary, our work presents comprehensive and integrative approaches to investigate both functional and structural aspects of DNA adenine methyltransferase (Dam1DR) in D. radiodurans biology.

Functional and regulatory aspects of oxidative stress response in X monosomy.

The partial/complete loss of one X chromosome in a human female leads to Turner syndrome (TS). TS individuals display a range of phenotypes including short stature, osteoporosis, ovarian malfunction, diabetes, and thyroid dysfunction. Epigenetic factors and regulatory networks are distinctly different in X monosomy (45, X). In a lifetime, an individual is exposed to a variety of stress conditions. To study whether X monosomy cells display a differential response upon exposure to mild stress as compared to normal 46, XX cells and whether this may contribute to various co-morbidities in aneuploid individuals, we have carried out a transcriptomic analysis of human fibroblasts 45, X and 46, XX after exposure to mild oxidative stress. Under these conditions, over 350 transcripts were seen to be differentially expressed in 45, X and 46, XX cells. Pathways associated with oxidative stress were differentially expressed highlighting the differential regulation of genes and associated phenotypes. It could be seen that X monosomy cells are more susceptible to oxidative stress as compared to normal cells and have altered molecular pathways both in normal conditions and also upon exposure to mild oxidative stress. To explore this aspect in detail, we have mapped the expressions of transcription factors (TFs) in 45, X and 46, XX cells. The network of transcription activating factors is differentially regulated in 45, X and 46, XX cells under stress exposure. It is tempting to speculate that the altered ability of 45, X (Turner) cells to respond to stress may play a significant role in the physiological function and altered phenotypes in Turner syndrome.

N6-methyladenine and epigenetic immunity of Deinococcus radiodurans.

DNA methylation is ubiquitously found in all three domains of life. This epigenetic modification on adenine or cytosine residues serves to regulate gene expression or to defend against invading DNA in bacteria. Here, we report the significance of N6-methyladenine (6mA) to epigenetic immunity in Deinococcus radiodurans. Putative protein encoded by DR_2267 ORF (Dam2DR) contributed 35% of genomic 6mA in D. radiodurans but did not influence gene expression or radiation resistance. Dam2DR was characterized to be a functional S-adenosyl methionine (SAM)-dependent N6-adenine DNA methyltransferase (MTase) but with no endonuclease activity. Adenine methylation from Dam2DR or Dam1DR (N6-adenine MTase encoded by DR_0643) improved DNA uptake during natural transformation. To the contrary, methylation from Escherichia coli N6-adenine MTase (DamEC that methylates adenine in GATC sequence) on donor plasmid drastically reduced DNA uptake in D. radiodurans, even in presence of Dam2DR or Dam1DR methylated adenines. With these results, we conclude that self-type N6-adenine methylation on donor DNA had a protective effect in absence of additional foreign methylation, a separate methylation-dependent Restriction Modification (R-M) system effectively identifies and limits uptake of G6mATC sequence containing donor DNA. This is the first report demonstrating presence of epigenetic immunity in D. radiodurans.

Construction, analysis and validation of co-expression network to understand stress adaptation in Deinococcus radiodurans R1.

Systems biology based approaches have been effectively utilized to mine high throughput data. In the current study, we have performed system-level analysis for Deinococcus radiodurans R1 by constructing a gene co-expression network based on several microarray datasets available in the public domain. This condition-independent network was constructed by Weighted Gene Co-expression Network Analysis (WGCNA) with 61 microarray samples from 9 different experimental conditions. We identified 13 co-expressed modules, of which, 11 showed functional enrichments of one or more pathway/s or biological process. Comparative analysis of differentially expressed genes and proteins from radiation and desiccation stress studies with our co-expressed modules revealed the association of cyan with radiation response. Interestingly, two modules viz darkgreen and tan was associated with radiation as well as desiccation stress responses. The functional analysis of these modules showed enrichment of pathways important for adaptation of radiation or desiccation stress. To decipher the regulatory roles of these stress responsive modules, we identified transcription factors (TFs) and then calculated a Biweight mid correlation between modules hub gene and the identified TFs. We obtained 7 TFs for radiation and desiccation responsive modules. The expressions of 3 TFs were validated in response to gamma radiation using qRT-PCR. Along with the TFs, selected close neighbor genes of two important TFs, viz., DR_0997 (CRP) and DR_2287 (AsnC family transcriptional regulator) in the darkgreen module were also validated. In our network, among 13 hub genes associated with 13 modules, the functionality of 5 hub genes which are annotated as hypothetical proteins (hypothetical hub genes) in D. radiodurans genome has been revealed. Overall the study provided a better insight of pathways and regulators associated with relevant DNA damaging stress response in D. radiodurans.

Characterization and DNA methylation modulatory activity of gold nanoparticles synthesized by Pseudoalteromonas strain.

Marine extremophiles are shown to tolerate extreme environmental conditions and have high metal reducing properties. Here, we report intracellular synthesis of gold nanoparticles (AuNP) by marine extremophilic bacteria Pseudoalteromonas sp. Bac178 which was isolated from the OMZ of Arabian Sea. Preliminary observations suggest that these bacteria use different pathways which may involves the membrane as well as intracellular proteins for the gold salt reduction. Characterization of the biosynthesised nanoparticles by various techniques such as Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Energy-dispersive X-ray spectroscopy (EDS) confirmed the presence of crystalline gold. These biologically synthesized AuNP were investigated for cytotoxicity and oxidative stress generation in human normal fibroblast and melanoma cells (A375). As AuNP are envisaged to find many applications in the medical field, it was of interest to study the effect of AuNP at the epigenetic level. They were found to be non-cytotoxic, non-genotoxic and non-oxidative stress generating over a range of concentrations. Exposure to these AuNP is observed to cause alterations in global DNA methylation as well as in the expression of DNA methyltransferase (DNMT) genes. Since biosynthesized AuNP are being used in various applications and therapies, their epigenetic modulatory activity needs careful consideration.

Aneuploidy: an important model system to understand salient aspects of functional genomics.

Maintaining a balance in gene dosage and protein activity is essential to sustain normal cellular functions. Males and females have a wide range of genetic as well as epigenetic differences, where X-linked gene dosage is an essential regulatory factor. Basic understanding of gene dosage maintenance has emerged from the studies carried out using mouse models with FCG (four core genotype) and chromosomal aneuploidy as well as from mono-chromosomal hybrid cells. In mammals, aneuploidy often leads to embryonic lethality particularly in early development with major developmental and structural abnormalities. Thus, in-depth analysis of the causes and consequences of gene dosage alterations is needed to unravel its effects on basic cellular and developmental functions as well as in understanding its medical implications. Cells isolated from individuals with naturally occurring chromosomal aneuploidy can be considered as true representatives, as these cells have stable chromosomal alterations/gene dosage imbalance, which have occurred by modulation of the basic molecular machinery. Therefore, innovative use of these natural aneuploidy cells/organisms with recent molecular and high-throughput techniques will provide an understanding of the basic mechanisms involved in gene dosage balance and the related consequences for functional genomics.

An exploration of microbial and associated functional diversity in the OMZ and non-OMZ areas in the Bay of Bengal.

Depletion of oxygen in certain marine areas creates oxygen minimum zones (OMZs), which can alter the species composition and abundance. We have carried out high-throughput 16S rRNA gene amplicon profiling from the Bay of Bengal (BOB) OMZ and non-OMZ areas. Typically, a total of 35 families of micro-organisms were identified as biomarkers for OMZ and non-OMZ regions in the BOB. Our analysis has identified families Pseudoalteromonadaceae, OM60 and Synechococcaceae to be abundant in oxygenated water, whereas organisms belonging to families Pelagibacteraceae and Caulobacteraceae, which are involved in sulphur and nitrogen metabolism, were prominent in the OMZ areas. Predictive functional analysis for these identified bacteria clearly that suggested an abundance of microbes with assimilatory sulphurreducing genes (cysl and csH) in the non-OMZ, while bacteria involved in dissimilatory sulphate reduction (known to carry aprA and aprB genes) were enriched in the OMZ areas. Comparative analysis with OMZ areas from Peru and Chile revealed that OMZ areas in the BOB are characterized by specific and distinctive bacterial diversity. Overall, the current analysis provides valuable documentation about the bacterial populations and their characteristics, which can generate pointers for their functional significance in the BOB.

Prediction of B cell and T cell epitopes of DBLalpha domain in Plasmodium falciparum malaria vaccine candidate var gene.

P. falciparum encodes PfEMP-1 which is important in pathogenicity and virulence. We have analyzed the structure of the Duffy binding like (DBLalpha) domain of var genes and predicted the antigenic sites and T and B cell epitopes which present a highly variable picture with major implications in immune interactions and vaccine design.

Micro RNAs and DNA methylation are regulatory players in human cells with altered X chromosome to autosome balance.

The gene balance hypothesis predicts that an imbalance in the dosage sensitive genes affects the cascade of gene networks that may influence the fitness of individuals. The phenotypes associated with chromosomal aneuploidies demonstrate the importance of gene dosage balance. We have employed untransformed human fibroblast cells with different number of X chromosomes to assess the expression of miRNAs and autosomal genes in addition to the DNA methylation status. High throughput NGS analysis using illumina Next seq500 has detected several autosomal as well as X linked miRNAs as differentially expressed in X monosomy and trisomy cells. Two of these miRNAs (hsa-miR-125a-5p and 335-5p) are likely to be involved in regulation of the autosomal gene expression. Additionally, our data demonstrates altered expression and DNA methylation signatures of autosomal genes in X monosomy and trisomy cells. In addition to miRNAs, expression of DNMT1 which is an important epigenetic player involved in many processes including cancer, is seen to be altered. Overall, present study provides a proof for regulatory roles of micro RNAs and DNA methylation in human X aneuploidy cells opening up possible new ways for designing therapeutic strategies.

Transcriptome Analysis Reveals Altered Expression of Memory and Neurotransmission Associated Genes in the REM Sleep Deprived Rat Brain.

Sleep disorders are associated with cognitive impairment. Selective rapid eye movement sleep (REMS) deprivation (REMSD) alters several physiological processes and behaviors. By employing NGS platform we carried out transcriptomic analysis in brain samples of control rats and those exposed to REMSD. The expression of genes involved in chromatin assembly, methylation, learning, memory, regulation of synaptic transmission, neuronal plasticity and neurohypophysial hormone synthesis were altered. Increased transcription of BMP4, DBH and ATP1B2 genes after REMSD supports our earlier findings and hypothesis. Alteration in the transcripts encoding histone subtypes and important players in chromatin remodeling was observed. The mRNAs which transcribe neurotransmitters such as OXT, AVP, PMCH and LNPEP and two small non-coding RNAs, namely RMRP and BC1 were down regulated. At least some of these changes are likely to regulate REMS and may participate in the consequences of REMS loss. Thus, the findings of this study have identified key epigenetic regulators and neuronal plasticity genes associated to REMS and its loss. This analysis provides a background and opens up avenues for unraveling their specific roles in the complex behavioral network particularly in relation to sustained REMS-loss associated changes.

Rapid detection of Escherichia coli by using antibody-conjugated silver nanoshells.

Silver shells of 20 nm thickness have been deposited on silica particles of 200 nm diameter with narrow size distribution. Silver nanoshells dispersed in water exhibit a strong surface plasmon resonance band at 443 nm. This band was found to be very sensitive to rabbit immunoglobulin G antibodies, which were anchored on the nanoshells. These in turn could be utilized to detect the presence of small (approximately 5) to large numbers (approximately 10(9)) of Escherichia coli in water. The protocol presented here proves to be a specific, rapid, reliable, and inexpensive method to detect E. coli.

Study of inheritance of diabetes mellitus in Western Indian population by pedigree analysis.

OBJECTIVES: To study the inheritance pattern of diabetes mellitus in Western Indian population by analysing the pedigree of diabetes patients. METHODS: 3,921 individuals from 300 families were interviewed for family history in this study, out of which 770 were diabetic individuals. Statistical analysis of the data was carried out using T-test and Chi-square test. RESULTS: 37% cases of Type 1 DM and 58% cases of Type 2 DM showed family history of the disease. Of the cases showing family history for diabetes, 92% in case of Type 1 DM and 59% in case of Type 2 DM showed family history of Type 2 DM with a decrease in age of onset in the successive generations. Both the parents, when diabetic conferred equal risk of inheriting diabetes in offspring. The sex ratio of offspring suffering from diabetes was not influenced when only one of the parents was diabetic. However it was observed that the male offspring were highly susceptible when both parents were diabetic (Chi-square value=4.55 with 1 d.f.). The age of onset of diabetes did not show significant correlation with whether one or both the parents were diabetic. However, it was noteworthy that in case of familial history of diabetes there was a decrease in the age of onset in successive generations. CONCLUSION: This study suggests that family history of diabetes results in predisposition to early onset of the disease in successive generations and a cluster of genes involved in Type 2 DM may show a parental effect for predisposition to Type 1 DM in the offspring in this set of Indian population.

Epigenetic modulation upon exposure of lung fibroblasts to TiO2 and ZnO nanoparticles: alterations in DNA methylation.

Titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs) are promising candidates for numerous applications in consumer products. This will lead to increased human exposure, thus posing a threat to human health. Both these types of NPs have been studied for their cell toxicity, immunotoxicity, and genotoxicity. However, effects of these NPs on epigenetic modulations have not been studied. Epigenetics is an important link in the genotype and phenotype modulation and misregulation can often lead to lifestyle diseases. In this study, we have evaluated the DNA methylation-based epigenetic changes upon exposure to various concentrations of NPs. The investigation was designed to evaluate global DNA methylation, estimating the corresponding methyltransferase activity and expression of Dnmt gene using lung fibroblast (MRC5) cell line as lungs are the primary route of entry and target of occupational exposure to TiO2 and ZnO NPs. Enzyme-linked immunosorbent assay-based immunochemical assay revealed dose-related decrease in global DNA methylation and DNA methyltransferase activity. We also found direct correlation between the concentration of NPs, global methylation levels, and expression levels of Dnmt1, 3A, and 3B genes upon exposure. This is the first study to investigate effect of exposure to TiO2 and ZnO on DNA methylation levels in MRC5 cells. Epigenetic processes are known to play an important role in reprogramming and adaptation ability of an organism and can have long-term consequences. We suggest that changes in DNA methylation can serve as good biomarkers for early exposure to NPs since they occur at concentrations well below the sublethal levels. Our results demonstrate a clear epigenetic alteration in response to metal oxide NPs and that this effect was dose-dependent.

Design and development of a web-based application for diabetes patient data management.

A web-based database management system developed for collecting, managing and analysing information of diabetes patients is described here. It is a searchable, client-server, relational database application, developed on the Windows platform using Oracle, Active Server Pages (ASP), Visual Basic Script (VB Script) and Java Script. The software is menu-driven and allows authorized healthcare providers to access, enter, update and analyse patient information. Graphical representation of data can be generated by the system using bar charts and pie charts. An interactive web interface allows users to query the database and generate reports. Alpha- and beta-testing of the system was carried out and the system at present holds records of 500 diabetes patients and is found useful in diagnosis and treatment. In addition to providing patient data on a continuous basis in a simple format, the system is used in population and comparative analysis. It has proved to be of significant advantage to the healthcare provider as compared to the paper-based system.