307 research outputs found

    A Phytochemical Study of Some Nepalese Liverworts

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    This thesis describes a phytochemical investigation of three members of the Hepaticae family (liverworts) from Nepal. The species examined were Marchantia paleacea Betrol subsp. paleacea, Marchantia papillata Raddi subsp. grossibarba (steph) Bishl and Plagiochasma appendiculatum Lehm et. Lindenb. M. paleacea yielded the bisbibenzyl derivatives marchantins A, C and D, p-hydroxybenzaldehyde, 2-hydroxy-3,7-dimethoxyphenanthrene, the corresponding 1,1-dimer and the interesting new compound 3,4-dihydro-8-hydroxy-4-(4-hydroxyphenyl)-isocoumarin. Marchantins A and C and the above phenanthrene were obtained from M. papillata while marchantins A and B and riccardin D were isolated from Plagiochasma appendiculatum. The structures were assigned from 1 D and 2D 1H and 13C NMR spectra and were confirmed, where appropriate, by comparison with published data. The thesis is prefaced by a general review of the Hepaticae and their chemical constituents

    <i>Plasmodium </i>Condensin Core Subunits SMC2/SMC4 Mediate Atypical Mitosis and Are Essential for Parasite Proliferation and Transmission

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    Condensin is a multi-subunit protein complex regulating chromosome condensation and segregation during cell division. In Plasmodium spp., the causative agent of malaria, cell division is atypical and the role of condensin is unclear. Here we examine the role of SMC2 and SMC4, the core subunits of condensin, during endomitosis in schizogony and endoreduplication in male gametogenesis. During early schizogony, SMC2/SMC4 localize to a distinct focus, identified as the centromeres by NDC80 fluorescence and chromatin immunoprecipitation sequencing (ChIP-seq) analyses, but do not form condensin I or II complexes. In mature schizonts and during male gametogenesis, there is a diffuse SMC2/SMC4 distribution on chromosomes and in the nucleus, and both condensin I and condensin II complexes form at these stages. Knockdown of smc2 and smc4 gene expression reveals essential roles in parasite proliferation and transmission. The condensin core subunits (SMC2/SMC4) form different complexes and may have distinct functions at various stages of the parasite life cycle

    MRE11 Is Crucial for Malaria Parasite Transmission and Its Absence Affects Expression of Interconnected Networks of Key Genes Essential for Life

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    The meiotic recombination 11 protein (MRE11) plays a key role in DNA damage response and maintenance of genome stability. However, little is known about its function during development of the malaria parasite Plasmodium. Here, we present a functional, ultrastructural and transcriptomic analysis of Plasmodium parasites lacking MRE11 during its life cycle in both mammalian and mosquito vector hosts. Genetic disruption of Plasmodium berghei mre11 (PbMRE11) results in significant retardation of oocyst development in the mosquito midgut associated with cytoplasmic and nuclear degeneration, along with concomitant ablation of sporogony and subsequent parasite transmission. Further, absence of PbMRE11 results in significant transcriptional downregulation of genes involved in key interconnected biological processes that are fundamental to all eukaryotic life including ribonucleoprotein biogenesis, spliceosome function and iron-sulfur cluster assembly. Overall, our study provides a comprehensive functional analysis of MRE11's role in Plasmodium development during the mosquito stages and offers a potential target for therapeutic intervention during malaria parasite transmission

    Distress, anxiety, and depression in cancer patients undergoing chemotherapy

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    BACKGROUND: Chemotherapy for cancer is an intense and cyclic treatment associated with number of side-effects. The present study evaluated the effect of chemotherapy on distress, anxiety and depression. PATIENTS AND METHODS: A total of 117 patients were evaluated by using distress inventory for cancer (DIC2) and hospital anxiety and depression scale (HADS). Majority of the patients were taking chemotherapy for solid tumors (52; 44.4%). RESULTS: The mean distress score was 24, 18 (15.38%) were found to have anxiety while 19 (16.23%) had depression. High social status was the only factor found to influence distress while female gender was the only factor found to influence depression in the present study. CONCLUSION: The study highlights high psychological morbidity of cancer patients and influence of gender on depression. Construct of distress as evaluated by DIC 2 may have a possible overlap with anxiety

    Photosensitized INA-Labelled protein 1 (PhIL1) is novel component of the inner membrane complex and is required for Plasmodium parasite development.

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    Plasmodium parasites, the causative agents of malaria, possess a distinctive membranous structure of flattened alveolar vesicles supported by a proteinaceous network, and referred to as the inner membrane complex (IMC). The IMC has a role in actomyosin-mediated motility and host cell invasion. Here, we examine the location, protein interactome and function of PhIL1, an IMC-associated protein on the motile and invasive stages of both human and rodent parasites. We show that PhIL1 is located in the IMC in all three invasive (merozoite, ookinete-, and sporozoite) stages of development, as well as in the male gametocyte and locates both at the apical and basal ends of ookinete and sporozoite stages. Proteins interacting with PhIL1 were identified, showing that PhIL1 was bound to only some proteins present in the glideosome motor complex (GAP50, GAPM1-3) of both P. falciparum and P. berghei. Analysis of PhIL1 function using gene targeting approaches indicated that the protein is required for both asexual and sexual stages of development. In conclusion, we show that PhIL1 is required for development of all zoite stages of Plasmodium and it is part of a novel protein complex with an overall composition overlapping with but different to that of the glideosome
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