59 research outputs found

    SURVEY OF PULMONARY TUBERCULOSIS BASED ON SYMPTOMS AND SPUTUM EXAMINATION IN CHIKKAMAGALURU

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    Objectives: Tuberculosis (TB) is the most common problem in the world. This study was aimed to assess the gender, age, and occupation prevalence rate of TB infection in Chikkamagaluru, Karnataka, India. Methods: The survey was carried out in Chikkamagaluru from January to May 2012. The data were collected by direct interview of the patients with the help of medical officers. Then, the data were assessed and categorized based on gender, age, and occupation. Results: A total of 97 pulmonary TB patients were identified, among them, males are more (74.22%) prone to TB than that of females (25.72%). This may be because males are more exposed to smoking, drinking, etc. The data were also scrutinized for age-wise distribution of pulmonary TB, and it was found that patients in the age group of 41–50 years are more affected than the other age group, and pulmonary TB was more prominent than extrapulmonary TB. The Mycobacterium tuberculae patients grading are more in 3+ than in 2+ and 1+ grading type of TB affected individuals. Conclusion: This study concludes that males are more to TB due to abuse of alcohol, smoking, and occupation-wise laborers which are more infected

    Identification of Novel Antimalarial Chemotypes via Chemoinformatic Compound Selection Methods for a High-Throughput Screening Program against the Novel Malarial Target, PfNDH2: Increasing Hit Rate via Virtual Screening Methods

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    Malaria is responsible for approximately 1 million deaths annually; thus, continued efforts to discover new antimalarials are required. A HTS screen was established to identify novel inhibitors of the parasite's mitochondrial enzyme NADH:quinone oxidoreductase (PfNDH2). On the basis of only one known inhibitor of this enzyme, the challenge was to discover novel inhibitors of PfNDH2 with diverse chemical scaffolds. To this end, using a range of ligand-based chemoinformatics methods, ~17000 compounds were selected from a commercial library of ~750000 compounds. Forty-eight compounds were identified with PfNDH2 enzyme inhibition IC(50) values ranging from 100 nM to 40 μM and also displayed exciting whole cell antimalarial activity. These novel inhibitors were identified through sampling 16% of the available chemical space, while only screening 2% of the library. This study confirms the added value of using multiple ligand-based chemoinformatic approaches and has successfully identified novel distinct chemotypes primed for development as new agents against malaria

    Identification, Design and Biological Evaluation of Heterocyclic Quinolones Targeting Plasmodium falciparum Type II NADH:Quinone Oxidoreductase (PfNDH2)

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    Following a program undertaken to identify hit compounds against NADH:ubiquinone oxidoreductase (PfNDH2), a novel enzyme target within the malaria parasite Plasmodium falciparum, hit to lead optimization led to identification of CK-2-68, a molecule suitable for further development. In order to reduce ClogP and improve solubility of CK-2-68 incorporation of a variety of heterocycles, within the side chain of the quinolone core, was carried out, and this approach led to a lead compound SL-2-25 (8b). 8b has IC(50)s in the nanomolar range versus both the enzyme and whole cell P. falciparum (IC(50) = 15 nM PfNDH2; IC(50) = 54 nM (3D7 strain of P. falciparum) with notable oral activity of ED(50)/ED(90) of 1.87/4.72 mg/kg versus Plasmodium berghei (NS Strain) in a murine model of malaria when formulated as a phosphate salt. Analogues in this series also demonstrate nanomolar activity against the bc(1) complex of P. falciparum providing the potential added benefit of a dual mechanism of action. The potent oral activity of 2-pyridyl quinolones underlines the potential of this template for further lead optimization studies

    A tetraoxane-based antimalarial drug candidate that overcomes PfK13-C580Y dependent artemisinin resistance.

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    K13 gene mutations are a primary marker of artemisinin resistance in Plasmodium falciparum malaria that threatens the long-term clinical utility of artemisinin-based combination therapies, the cornerstone of modern day malaria treatment. Here we describe a multinational drug discovery programme that has delivered a synthetic tetraoxane-based molecule, E209, which meets key requirements of the Medicines for Malaria Venture drug candidate profiles. E209 has potent nanomolar inhibitory activity against multiple strains of P. falciparum and P. vivax in vitro, is efficacious against P. falciparum in in vivo rodent models, produces parasite reduction ratios equivalent to dihydroartemisinin and has pharmacokinetic and pharmacodynamic characteristics compatible with a single-dose cure. In vitro studies with transgenic parasites expressing variant forms of K13 show no cross-resistance with the C580Y mutation, the primary variant observed in Southeast Asia. E209 is a superior next generation endoperoxide with combined pharmacokinetic and pharmacodynamic features that overcome the liabilities of artemisinin derivatives

    Identification, Design and Biological Evaluation of Bisaryl Quinolones Targeting Plasmodium falciparum Type II NADH:Quinone Oxidoreductase (PfNDH2)

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    A program was undertaken to identify hit compounds against NADH:ubiquinone oxidoreductase (PfNDH2), a dehydrogenase of the mitochondrial electron transport chain of the malaria parasite Plasmodium falciparum. PfNDH2 has only one known inhibitor, hydroxy-2-dodecyl-4-(1H)-quinolone (HDQ), and this was used along with a range of chemoinformatics methods in the rational selection of 17 000 compounds for high-throughput screening. Twelve distinct chemotypes were identified and briefly examined leading to the selection of the quinolone core as the key target for structure-activity relationship (SAR) development. Extensive structural exploration led to the selection of 2-bisaryl 3-methyl quinolones as a series for further biological evaluation. The lead compound within this series 7-chloro-3-methyl-2-(4-(4-(trifluoromethoxy)benzyl)phenyl)quinolin-4(1H)-one (CK-2-68) has antimalarial activity against the 3D7 strain of P. falciparum of 36 nM, is selective for PfNDH2 over other respiratory enzymes (inhibitory IC(50) against PfNDH2 of 16 nM), and demonstrates low cytotoxicity and high metabolic stability in the presence of human liver microsomes. This lead compound and its phosphate pro-drug have potent in vivo antimalarial activity after oral administration, consistent with the target product profile of a drug for the treatment of uncomplicated malaria. Other quinolones presented (e.g., 6d, 6f, 14e) have the capacity to inhibit both PfNDH2 and P. falciparum cytochrome bc(1), and studies to determine the potential advantage of this dual-targeting effect are in progress

    Wdpcp, a PCP Protein Required for Ciliogenesis, Regulates Directional Cell Migration and Cell Polarity by Direct Modulation of the Actin Cytoskeleton

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    Planar cell polarity (PCP) regulates cell alignment required for collective cell movement during embryonic development. This requires PCP/PCP effector proteins, some of which also play essential roles in ciliogenesis, highlighting the long-standing question of the role of the cilium in PCP. Wdpcp, a PCP effector, was recently shown to regulate both ciliogenesis and collective cell movement, but the underlying mechanism is unknown. Here we show Wdpcp can regulate PCP by direct modulation of the actin cytoskeleton. These studies were made possible by recovery of a Wdpcp mutant mouse model. Wdpcp-deficient mice exhibit phenotypes reminiscent of Bardet-Biedl/Meckel-Gruber ciliopathy syndromes, including cardiac outflow tract and cochlea defects associated with PCP perturbation. We observed Wdpcp is localized to the transition zone, and in Wdpcp-deficient cells, Sept2, Nphp1, and Mks1 were lost from the transition zone, indicating Wdpcp is required for recruitment of proteins essential for ciliogenesis. Wdpcp is also found in the cytoplasm, where it is localized in the actin cytoskeleton and in focal adhesions. Wdpcp interacts with Sept2 and is colocalized with Sept2 in actin filaments, but in Wdpcp-deficient cells, Sept2 was lost from the actin cytoskeleton, suggesting Wdpcp is required for Sept2 recruitment to actin filaments. Significantly, organization of the actin filaments and focal contacts were markedly changed in Wdpcp-deficient cells. This was associated with decreased membrane ruffling, failure to establish cell polarity, and loss of directional cell migration. These results suggest the PCP defects in Wdpcp mutants are not caused by loss of cilia, but by direct disruption of the actin cytoskeleton. Consistent with this, Wdpcp mutant cochlea has normal kinocilia and yet exhibits PCP defects. Together, these findings provide the first evidence, to our knowledge, that a PCP component required for ciliogenesis can directly modulate the actin cytoskeleton to regulate cell polarity and directional cell migration

    Magnetohydrodynamic free convection flow past an oscillating plate embedded in a porous medium

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    The objective of this paper is to study the radiation and thermal diffusion/Soret effects on a magnetohydrodynamic (MHD) free convection flow of an incompressible viscous fluid near an oscillating plate embedded in a porous medium. The governing coupled linear partial differential equations are solved analytically using Laplace transform method. The results for velocity, temperature and concentration fields are obtained. The deduced results for skin friction, Nusselt number and Sherwood number are computed numerically in tabular forms. Graphs are plotted to see the effects of various embedded flow parameters. A detailed discussion of these flow parameters along with their physical interpretation is also presented and appropriate conclusion are drawn

    Effect of poling process on piezoelectric properties of sol-gel derived BZT-BCT ceramics

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    Lead free piezoelectric ceramics barium zirconate titanate-barium calcium titanate, [xBZT-(1-x)BCT] (0.48≤ x ≤0.52), were synthesized by sol-gel method. Calcination of the as-synthesized precursor powders resulted in crystalline powders with single-phase perovskite structure at 700°C, which is significantly lower than that obtained by solid-state reaction. Solid-state sintering at 1450°C resulted in highly dense microstructure with ≥95% of the theoretical density. The effect of electric poling on the piezoelectric properties of the sintered [xBZT-(1-x)BCT] ceramics is studied with varying poling temperatures and poling fields. The results indicated that optimized poling conditions are required in enhancing the piezoelectric properties of [xBZT-(1-x)BCT] ceramics. The morphotropic phase boundary (MPB) composition, 0.5BZT-0.5BCT, showed a high remanent polarization (P r) of 12.2μC/cm2 and a low coercive field (E c) of ~0.14kV/mm. The optimized poling conditions resulted in high piezoelectric charge coefficient d 33 ~637pC/N, large electromechanical coupling coefficient k p ~59.6%, a large strain of 0.157%, a large piezoelectric voltage constant g 33 ~29mVm/N for (0.5BZT-0.5BCT) composition. In this report, the excellent piezoelectric properties of the sol-gel derived BZT-BCT ceramics has been analysed and correlated to its structure and poling conditions

    Targeting the mitochondrial electron transport chain of Plasmodium falciparum: new strategies towards the development of improved antimalarials for the elimination era.

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    Despite intense efforts, there has not been a truly new antimalarial, possessing a novel mechanism of action, registered for over 10 years. By virtue of a novel mode of action, it is hoped that the global challenge of multidrug-resistant parasites can be overcome, as well as developing drugs that possess prophylaxis and/or transmission-blocking properties, towards an elimination agenda. Many target-based and whole-cell screening drug development programs have been undertaken in recent years and here an overview of specific projects that have focused on targeting the parasite's mitochondrial electron transport chain is presented. Medicinal chemistry activity has largely focused on inhibitors of the parasite cytochrome bc1 Complex (Complex III) including acridinediones, pyridones and quinolone aryl esters, as well as inhibitors of dihydroorotate dehydrogenase that includes triazolopyrimidines and benzimidazoles. Common barriers to progress and opportunities for novel chemistry and potential additional electron transport chain targets are discussed in the context of the target candidate profiles for uncomplicated malaria
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