Publications by authors named "Shrawan Mishra"

While stripe phases with broken rotational symmetry of charge density are known to emerge in doped strongly correlated perovskites, the dynamics and heterogeneity of spatial ordering remain elusive. Here we shed light on the temperature dependent lattice motion and the spatial nanoscale phase separation of charge density wave order in the archetypal striped phase in LaSrNiO (LSNO) perovskite using X-ray photon correlation spectroscopy (XPCS) joint with scanning micro X-ray diffraction (SµXRD). While it is known that the CDW in 1/8 doped cuprates shows a remarkable stability we report the CDW motion dynamics by XPCS in nickelates with an anomalous quantum glass regime at low temperature, T < 65 K, and the expected thermal melting at higher temperature 65 < T < 120 K.

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We study the temporal stability of stripe-type spin order in a layered nickelate with x-ray photon correlation spectroscopy and observe fluctuations on timescales of tens of minutes over a wide temperature range. These fluctuations show an anomalous temperature dependence: they slow down at intermediate temperatures and speed up on both heating and cooling. This behavior appears to be directly connected with spatial correlations: stripes fluctuate slowly when stripe correlation lengths are large and become faster when spatial correlations decrease.

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We present here the results of low-temperature magnetization and X-ray magnetic circular dichroism studies on the single crystals of BaFe12O19 which reveal for the first time the emergence of a spin glass phase, in coexistence with a long-range ordered ferrimagnetic phase, due to the freezing of the basal plane spin component.

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Glycolipid transfer proteins (GLTPs) were first identified over three decades ago as ~24kDa, soluble, amphitropic proteins that specifically accelerate the intermembrane transfer of glycolipids. Upon discovery that GLTPs use a unique, all-α-helical, two-layer 'sandwich' architecture (GLTP-fold) to bind glycosphingolipids (GSLs), a new protein superfamily was born. Structure/function studies have provided exquisite insights defining features responsible for lipid headgroup selectivity and hydrophobic 'pocket' adaptability for accommodating hydrocarbon chains of differing length and unsaturation.

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In vitro assessment of lipid intermembrane transfer activity by cellular proteins typically involves measurement of either radiolabeled or fluorescently labeled lipid trafficking between vesicle model membranes. Use of bilayer vesicles in lipid transfer assays usually comes with inherent challenges because of complexities associated with the preparation of vesicles and their rather short "shelf life". Such issues necessitate the laborious task of fresh vesicle preparation to achieve lipid transfer assays of high quality, precision, and reproducibility.

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Human GLTP on chromosome 12 (locus 12q24.11) encodes a 24 kD amphitropic lipid transfer protein (GLTP) that mediates glycosphingolipid (GSL) intermembrane trafficking and regulates GSL homeostatic levels within cells. Herein, we provide evidence that GLTP overexpression inhibits the growth of human colon carcinoma cells (HT-29; HCT-116), but spares normal colonic cells (CCD-18Co).

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The glycolipid transfer protein (GLTP) fold defines a superfamily of eukaryotic proteins that selectively transport sphingolipids (SLs) between membranes. However, the mechanisms determining the protein selectivity for specific glycosphingolipids (GSLs) are unclear. Here, we report the crystal structure of the GLTP homology (GLTPH) domain of human 4-phosphate adaptor protein 2 (FAPP2) bound with -oleoyl-galactosylceramide.

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The macroautophagy/autophagy and inflammasome pathways are linked through their roles in innate immunity and chronic inflammatory disease. Ceramide-1-phosphate (C1P) is a bioactive sphingolipid that regulates pro-inflammatory eicosanoid production. Whether C1P also regulates autophagy and inflammasome assembly/activation is not known.

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High-risk populations exhibit early transformation of localized prostate cancer (CaP) disease to metastasis which results in the mortality of such patients. The paucity of knowledge about the molecular mechanism involved in acquiring of metastatic behavior by primary tumor cells and non-availability of reliable phenotype-discriminating biomarkers are stumbling blocks in the management of CaP disease. Here, we determine the role and translational relevance of ROBO1 (an organogenesis-associated gene) in human CaP.

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Phosphorylated sphingolipids ceramide-1-phosphate (C1P) and sphingosine-1-phosphate (S1P) have emerged as key regulators of cell growth, survival, migration and inflammation. C1P produced by ceramide kinase is an activator of group IVA cytosolic phospholipase A2α (cPLA2α), the rate-limiting releaser of arachidonic acid used for pro-inflammatory eicosanoid production, which contributes to disease pathogenesis in asthma or airway hyper-responsiveness, cancer, atherosclerosis and thrombosis. To modulate eicosanoid action and avoid the damaging effects of chronic inflammation, cells require efficient targeting, trafficking and presentation of C1P to specific cellular sites.

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Apigenin, a dietary flavonoid, is reported to have several therapeutic effects in different diseases including cancer. Toxicity of Apigenin is however, least explored, and reports are scanty in literature. This warrants dose-specific evaluation of toxicity in vivo.

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Activated Kras gene coupled with activation of Akt and nuclear factor-kappa B (NF-κB) triggers the development of pancreatic intraepithelial neoplasia, the precursor lesion for pancreatic ductal adenocarcinoma (PDAC) in humans. Therefore, intervention at premalignant stage of disease is considered as an ideal strategy to delay the tumor development. Pancreatic malignant tumor cell lines are widely used; however, there are not relevant cell-based models representing premalignant stages of PDAC to test intervention agents.

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The fatality of cancer is mainly bestowed to the property of otherwise benign tumor cells to become malignant and invade surrounding tissues by circumventing normal tissue barriers through a process called metastasis. S100A4 which is a member of the S100 family of calcium-binding proteins has been shown to be able to activate and integrate pathways both intracellular and extracellular to generate a phenotypic response characteristic of cancer metastasis. A large number of studies have shown an increased expression level of S100A4 in various types of cancers.

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Purpose: Conventional therapies to treat prostate cancer (CaP) of androgen-dependent phenotype (ADPC) and castration-resistant phenotype (CRPC) are deficient in outcome which has necessitated a need to identify those agents that could target AR for both disease types. We provide mechanism-based evidence that lupeol (Lup-20(29)-en-3b-ol) is a potent inhibitor of androgen receptor (AR) in vitro and in vivo.

Experimental Design: Normal prostate epithelial cell (RWPE-1), LAPC4 (wild functional AR/ADPC), LNCaP (mutant functional/AR/ADPC), and C4-2b (mutant functional/AR/CRPC) cells were used to test the anti-AR activity of lupeol.

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Background: Amodiaquine (AQ) along with sulphadoxine-pyrimethamine (SP) offers effective and cheaper treatment against chloroquine-resistant falciparum malaria in many parts of sub-Saharan Africa. Considering the previous history of hepatitis, agranulocytosis and neutrocytopenia associated with AQ monotherapy, it becomes imperative to study the toxicity of co-administration of AQ and SP. In this study, toxicity and resulting global differential gene expression was analyzed following exposure to these drugs in experimental Swiss mice.

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Background: Susceptibility/resistance to Plasmodium falciparum malaria has been correlated with polymorphisms in more than 30 human genes with most association analyses having been carried out on patients from Africa and south-east Asia. The aim of this study was to examine the possible contribution of genetic variants in the TNF and FCGR2A genes in determining severity/resistance to P. falciparum malaria in Indian subjects.

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