Prevalence of duodenal ulcer-promoting gene (dupA) of Helicobacter pylori in patients with duodenal ulcer in North Indian population

BACKGROUND: The duodenal ulcer (DU)-promoting gene (dupA) of Helicobacter pylori has been identified as a novel virulent marker associated with an increased risk for DU. The presence or absence of dupA gene of H. pylori present in patients with DU and functional dyspepsia in North Indian population was studied by polymerase chain reaction (PCR) and hybridization analysis. MATERIALS AND METHODS: One hundred and sixty-six patients (96 DU and 70 functional dyspepsia) were included in this study. In addition, sequence diversity of dupA gene of H. pylori found in these patients was analyzed by sequencing the PCR products jhp0917 and jhp0918 on both strands with appropriate primers. RESULTS: PCR and hybridization analyses indicated that dupA gene was present in 37.5% (36/96) of H. pylori strains isolated from DU patients and 22.86% (16/70) of functional dyspepsia patients (p < or = .05). Of these, 35 patients with DU (97.2%) and 14 patients with functional dyspepsia (81.25%) were infected by H. pylori positive for cagA genotype. Furthermore, the presence of dupA was significantly associated with the cagA-positive genotype (p < or = .02). CONCLUSION: Results of our study have shown that significant association of dupA gene with DU in this population. The dupA gene can be considered as a novel virulent marker for DU in this population.     

Activation of Microtubule Dynamics Increases Neuronal Growth via the Nerve Growth Factor (NGF)- and Gαs-mediated Signaling Pathways

Signals that activate the G protein Gα_s and promote neuronal differentiation evoke Gα_s internalization in rat pheochromocytoma (PC12) cells. These agents also significantly increase Gα_s association with microtubules, resulting in an increase in microtubule dynamics because of the activation of tubulin GTPase by Gα_s. To determine the function of Gα_s/microtubule association in neuronal development, we used real-time trafficking of a GFP-Gα_s fusion protein. GFP-Gα_s concentrates at the distal end of the neurites in differentiated living PC12 cells as well as in cultured hippocampal neurons. Gα_s translocates to specialized membrane compartments at tips of growing neurites. A dominant-negative Gα chimera that interferes with Gα_s binding to tubulin and activation of tubulin GTPase attenuates neurite elongation and neurite number both in PC12 cells and primary hippocampal neurons. This effect is greatest on differentiation induced by activated Gα_s. Together, these data suggest that activated Gα_s translocates from the plasma membrane and, through interaction with tubulin/microtubules in the cytosol, is important for neurite formation, development, and outgrowth. Characterization of neuronal G protein dynamics and their contribution to microtubule dynamics is important for understanding the molecular mechanisms by which G protein-coupled receptor signaling orchestrates neuronal growth and differentiation.     

Synthesis and biological evaluation of estradiol linked pyrrolo[2,1-c][1,4]benzodiazepine (PBD) conjugates as potential anticancer agents

A series of new estradiol linked pyrrolo[2,1-c][1,4]benzodiazepine (E(2)-PBD) conjugates (3a-f, 4a-f and 5a-f) with different linker architectures including a triazole moiety have been designed and synthesized. All the 18 compounds have been evaluated for their anticancer activity and it is observed that some of the compounds particularly 4c-e and 5c,d exhibited significant anticancer activity. The detailed biological aspects relating to the cell cycle effects and tubulin depolymerization activity have been examined with a view to understand the mechanism of action of these conjugates. Among all these conjugates, one of the compound 5c could be considered as the most effective compound particularly against MCF-7 breast cancer cell line.     

Biochemical evaluation of bioelectricity production process from anaerobic wastewater treatment in a single chambered microbial fuel cell (MFC) employing glass wool membrane

Biochemical functioning of single chambered microbial fuel cell (MFC) using glass wool as proton exchange membrane (PEM) operated with selectively enriched acidogenic mixed culture was evaluated in terms of bioelectricity production and wastewater treatment. Performance of MFC was studied at two different organic/substrate loading rates (OLR) (2.64 and 3.54 kg COD/m(3)) and operating pH 6 and 7 using non-coated plain graphite electrodes (mediatorless anode; air cathode). Applied OLR in association with operating pH showed marked influence on the power output and substrate degradation efficiency. Higher current density was observed at acidophilic conditions [pH 6; 98.13 mA/m(2) (2.64 kg COD/m(3)-day; 100 Omega) and 111.29 mA/m(2) (3.54 kg COD/m(3)-day; 100 Omega)] rather than neutral conditions [pH 7; 100.52 mA/m(2) (2.64 kg COD/m(3)-day; 100 Omega) and 98.13 mA/m(2) (3.54 kg COD/m(3)-day; 100 Omega)]. On the contrary, effective substrate degradation was observed at neutral pH. MFC performance was evaluated employing polarization curve, impedance analysis, cell potential, Coulombic efficiency and bioprocess monitoring. Sustainable power yield was calculated at stable cell potential.     

Characterization of Aspergillus fumigatus protein disulfide isomerase family gene.

Aspergillus fumigatus is an opportunistic fungus which causes pulmonary complications in humans and animals. The clinical spectrum observed with A. fumigatus is attributed to the multifunctional nature of its antigens. Lack of understanding on the molecular processes and complexity of the fungus have spurred interest in the identification and characterization of its antigens/allergens with biological activities and virulence functions. For identification of some of these antigens/allergens, a cDNA library of A. fumigatus was screened with antibodies of allergic bronchopulmonary aspergillosis (ABPA) patients. One of the reactive clones was sequenced and observed to have an open reading frame of 1095 nucleotides corresponding to a polypeptide of 364 amino acids. The nucleotide and deduced amino acid sequence showed significant homology with the protein disulfide isomerase (PDI) superfamily. The expressed recombinant fusion protein exhibited specific IgG and IgE binding with antibodies present in ABPA patients' sera. The recombinant protein in vitro catalyzed folding of scrambled RNase. The probable epitopic regions of the deduced amino acid sequence were mapped by algorithmic analysis. This is the first report of isolation of a gene encoding a member of the PDI family from A. fumigatus. The PDI superfamily of proteins may play an important role in the protein folding mechanisms of A. fumigatus antigens/allergens for their interaction with the host.