Absract Archive . November 2010 Full length Article Insilico Sequence Analysis of Virulence Genes of Salmonella typhi Abstract Salmonella typhi is an enteric bacterium causing typhoid fever and Gastroenteritis under complications. Worldwide, the incidence of Salmonellosis is estimated at 1.3 billion cases per year. Secretory proteins are responsible for its pathogenesis. OmpR gene encodes outer membrane protein (Porin) and PhoP is a virulence regulator in response to environmental conditions. EnvZ is required for the formation of lysosomes. This study was aimed to predict the structure from its sequence and to construct a model. OmpR & PhoP protein sequence of Salmonella typhi was analyzed and its 3D structure was predicted using Bioinformatics tools. 3D Structure was constructed following the steps of Homology modeling. The determinative sites of predicted structure were analyzed by superimposing the reference models. Thus the obtained results might pave the way for designing of novel drugs insilico that target virulence mechanism in Salmonella typhi. Keywords: Modelling; insilico; Virulence genes; Antibiotics; Binding sites Authors : *S.Arjunan1, T.S.Gnanendra2 and T.Viswanathan3 *Corresponding Author: pavima08@gmail.com Full length Article Dexamethasone Encapsulation in Gelatin Nanoparticles Abstract Nanobiotechnology, an integration of physical sciences, molecular engineering, biology, chemistry and biotechnology holds considerable promise of advances in pharmaceuticals and healthcare. New drug delivery systems in which pharmacologically active chemicals are attached to nanoscale coated particles offer the exciting prospect of site specific treatment with reduced side effects from indiscriminate action. Due to their size, nanoparticles have the advantage of reaching otherwise less accessible sites in the body by escaping phagocytosis and entering tiny capillaries. Dexamethasone is a synthetic steroid mainly used in chemotherapy for the treatment of cancer. Gelatin being easily available, bioacceptable and biodegradable has a distinct advantage as a vehicle of drug delivery. Here, initially gelatin nanoparticles were prepared by simple two step desolvation procedure and all the conditions were optimized. Then dexamethasone loaded gelatin nanoparticles were prepared by the same desolvation method and release studies were performed. Scanning electron microscopy (SEM) is used to characterize the nanoparticles. Drug encapsulation was measured by UV spectroscopy. In vitro release studies were conducted across dialyzing membrane. The results concluded that desolvation method is well suited to produce gelatin nanoparticles and the preparative variables of the procedure can be fine tuned depending on the clinical application. Key words: Nanoparticles; Gelatin; SEM; Drug release; Dexamethasone. Authors : Asha George *Corresponding Author: ashageorge2@gmail.com   Full length Article Cluster Analysis of Expression Profiles of Estrogen Responsive Genes using Self Organizing Maps Abstract Cluster analysis of expression profiles is the task of assigning a set of gene expression patterns in the expression profiles into subsets called clusters so that expression profiles in the same cluster are similar than those in other clusters and it has been widespread in "omics" biology. The present study intends at clustering of the expression profiles of estrogen responsive genes in response to estrogen, zearalenone and its analogues using self organizing maps. This study determines clusters of the co-expressed and co-regulated estrogen responsive genes there by traces functionally related genes. The expression profiles of 120 estrogen responsive genes in response to 20 samples of estrogen, zearalenone and its analogues are retrieved from Gene Expression Omnibus. Self Organizing Map algorithm is written in MATLAB, a high-level technical computing language that provides interactive environment for algorithm development which clusters the expression profiles of 120 estrogen responsive genes in response to 20 samples of estrogen, zearalenone and its analogues into 30 clusters. Clusters 17, 6, 20, 27, 21, 22, 5, 29 formed significant clusters and contained 30, 19, 17, 9, 8, 8, 4, 3 estrogen responsive genes grouped together respectively. Clusters 2, 8, 9, 11, 18, and 28 had 2 estrogen responsive genes grouped together respectively in each of them. Clusters 3, 7, 12, 13, 15, 16, 19, 25, 26 and 30 remained unclustered and had only 1 estrogen responsive gene in each of them. Clusters 1, 4, 10, 14, 23, and 24 remained as null clusters and had 0 estrogen responsive genes. Keywords: Estrogen Responsive Genes; Estrogen; Zearalenone; Expression Profiles; Gene Expression Omnibus; Self Organizing Maps; Cluster Analysis. Authors : Santhosh Rebello and *Uma Maheshwari *Corresponding Authors: ugdreams@gmail.com Short Communication HPLC Analysis in the Stored Roots of Withania somnifera Abstract Plant secondary metabolites recently been referred to as phytochemicals are naturally occurring and biologically active compounds that have a potential disease inhibiting capabilities. The objective of this study was to sequentially extract and analyse the phytochemical constituents, compare secondary metabolite content during storage and develop a HPLC fingerprint for the roots of Withania somnifera. The method of sequential extraction was adopted and the suitable solvent for extraction of secondary metabolites was standardized. The extract of stored roots collected during four years were analysed using HPLC. The results revealed slight variation in the secondary compounds, which may be due to the deterioration of metabolites during storage. Keywords: Withania somnifera; Sequential extraction; HPLC; Storage Authors : *Supriya Sasindranathan, R. Parvatham, Kalaiselvi Senthil *Corresponding Author: supriya2011@gmail.com Short Communication Comparative Study on the Antimicrobial Activity of Probiotic Bacillus subtilis SK09 against Microbial Isolates from Dairy Effluent Abstract Health promoting microorganisms such as Probiotics are recently been used as food additive and therapeutic supplement in order to enhance prophylaxis and digestion. Probiotic organisms with their ability to inhibit the growth of pathogens by producing antimicrobial peptides, so-called bacteriocin would be of an added therapeutic value. In the present study we report the isolation and partial purification of bacteriocin from spore forming probiotic culture of Bacillus Subtilis SK09 and tested for its activity to inhibit the growth and proliferation E. coli. This antimicrobial property was compared against Lactobacilli sp. Yeast and Pseudomonas sp. that are isolated from dairy effluent. The dilution at which the maximum activity of bacteriocin was determined based on in-vitro zone clearance method. Here we report that Bacillus subtilis SK09 and Lactobacilli sp. are the potential probiotic strains showing maximum activity even at 10-5 dilution. Keywords: Probiotic bacteria; traveler's diarrhea; Zone clearance method; Antimicrobial activity. Authors : *G. Sreekumar, D. Dhurga, N. Uma Maheswari and Soundarajan Krishnan *Corresponding Author : goodsreekumar@gmail.com Tools and Rechniques Optimizing 3D Aggregate Culture Conditions for HEp-2 and A549 Cell Types –– A Tool for Novel Antigen Discovery and Other Applications Abstract Cells in culture are valuable for understanding the basic functioning and for application-oriented research. A comparative study of a cell type in 2D and 3D system gives us evidence for the functional superiority of cells cultured on 3D supports, the limitations of the 2D system and other applications. Here, we compare 2D monolayer and the 3D aggregate culture systems of HEp-2 against A549 cell line data. The comparative parameters are matrix composition and cell culture phase analysis. Monolayer HEp-2 cells in DMEM with 10% FBS were transformed into aggregates on Hydrogels. The plates were incubated at 37°C and monitored for the various culture characteristics like culture stage durations (lag, log, plateau and decline stages), sizes of the aggregates, number of aggregates with dividing cells (growing/expanding aggregates), medium clarity, percentage of confluency and the presence of well formed discrete aggregates. A grading system on a 3 point scale was followed for each of the above parameters mentioned to ascertain the optimal conditions to obtain 3D aggregates. A marked shift, the extended log to decline phase durations along-with a significant increase in the yield of cells, were observed. The culture condition which obtained the highest cumulative score of the six evaluating parameters was considered the optimum. Accordingly, it is inferred that 1.5% concentration of hydrogel and 0.25 ml volume of agarose, gave optimal aggregate generation with a seeding density 0.125 x 106 cells/well. Thus in vitro 3D environments closely mimic in vivo conditions from several aspects and comparative study of HEp-2 vs. A-549 cell lines give insights to utilize the culture models for both basic and applied research. Keywords: HEp-2; A549; 2D Monolayer; 3D Aggregate; Agarose hydrogel Authors : Allan S., Anirudh M., Bhavani M., Bhavna S., Deepika R., Ginila R., Joseph V., Madhumitha H., Priyanka A, Priyanka V., Ramya R., Shruthilaya M., Shruti A., Sowmya T., Walter J. and Ravi M.* *Corresponding Author : maddalyravi@hotmail.com