Publications by authors named "Sandeep Gopal"

Fertility requires the faithful proliferation of germ cells and their differentiation into gametes. Controlling these cellular states demands precise timing and expression of gene networks. Nucleic acid binding proteins (NBPs) play critical roles in gene expression networks that influence germ cell development.

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The developmental fate of cells is regulated by intrinsic factors and the extracellular environment. The extracellular matrix (matrisome) delivers chemical and mechanical cues that can modify cellular development. However, comprehensive understanding of how matrisome factors control cells in vivo is lacking.

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Purpose: Chest radiographs in critically ill patients can be difficult to interpret due to technical and clinical factors. We sought to determine the agreement of chest radiographs and CT scans, and the inter-observer variation of chest radiograph interpretation, in intensive care units (ICUs).

Methods: Chest radiographs and corresponding thoracic computerised tomography (CT) scans (as reference standard) were collected from 45 ICU patients.

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Nervous system function relies on the establishment of complex gene expression programs that provide neuron-type-specific and core pan-neuronal features. These complementary regulatory paradigms are controlled by terminal selector and parallel-acting transcription factors (TFs), respectively. Here, we identify the nuclear factor Y (NF-Y) TF as a pervasive direct and indirect regulator of both neuron-type-specific and pan-neuronal gene expression.

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Background: Acute kidney injury (AKI) is known to be associated with increased short-term mortality among cirrhotic patients. On this background, we designed this study to evaluate various causes of AKI among admitted patients with cirrhosis of liver and predictors of 90-day mortality.

Methods: One hundred and two consecutive adult patients with cirrhosis of liver with AKI hospitalized between November 2016 and March 2018 were enrolled in this prospective study.

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Background: Hospital acquired infections (HAI) in the cirrhotic patients contribute to hepatic decompensation. With emergence of bacterial drug resistance, designing the treatment protocol of HA infection has become the foremost challenge.

Purpose: To analyze the resistance pattern of organisms isolated from hospital-acquired (HA) infections and determine appropriate antibiotics treatment protocols for these infections.

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Communication between the soma and germline optimizes germ cell fate programs. Notch receptors are key determinants of germ cell fate but how somatic signals direct Notch-dependent germ cell behavior is undefined. Here we demonstrate that SDN-1 (syndecan-1), a somatic transmembrane proteoglycan, controls expression of the GLP-1 (germline proliferation-1) Notch receptor in the Caenorhabditis elegans germline.

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Splicing introns from precursor-messenger RNA (pre-mRNA) transcripts is essential for translating functional proteins. Here, we report that the previously uncharacterized Caenorhabditis elegans protein MOG-7 acts as a pre-mRNA splicing factor. Depleting MOG-7 from the C.

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Context: Radiology and pathology are pivotal tools in the investigational artillery for management of wide spectrum of hepatic lesions and early detection is of a paramount importance.

Aims: The study aimed at analyzing the efficacy, comparative yield and validity of image-guided aspiration cytology (FNA)/core biopsy (CB) in focal hepatic lesions.

Settings And Design: A retrospective hospital-based study was conducted in departments of Pathology and Radiology and Imaging of a tertiary care center.

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Cell-extracellular matrix interactions are crucial for the development of an organism from the earliest stages of embryogenesis. The main constituents of the extracellular matrix are collagens, laminins, proteoglycans and glycosaminoglycans that form a network of interactions. The extracellular matrix and its associated molecules provide developmental cues and structural support from the outside of cells during development.

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The syndecans are the major family of transmembrane proteoglycans, usually bearing multiple heparan sulfate chains. They are present on virtually all nucleated cells of vertebrates and are also present in invertebrates, indicative of a long evolutionary history. Genetic models in both vertebrates and invertebrates have shown that syndecans link to the actin cytoskeleton and can fine-tune cell adhesion, migration, junction formation, polarity and differentiation.

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Syndecans are transmembrane proteoglycans with heparan and chondroitin sulfate chains attached to their extracellular domain. Like many proteoglycans, they interact with a large number of ligands, such as growth factors, adhesion receptors, soluble small molecules, proteinases, and other extracellular matrix proteins to initiate downstream signaling pathways. Syndecans play a major role in inflammation, mainly by regulating leukocyte extravasation and cytokine function.

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Neurodegenerative diseases (NDs) affect millions of people worldwide. Characterized by the functional loss and death of neurons, NDs lead to symptoms (dementia and seizures) that affect the daily lives of patients. In spite of extensive research into NDs, the number of approved drugs for their treatment remains limited.

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Appropriate regulation of autophagy is crucial for clearing toxic proteins from cells. Defective autophagy results in accumulation of toxic protein aggregates that detrimentally affect cellular function and organismal survival. Here, we report that the microRNA miR-1 regulates the autophagy pathway through conserved targeting of the orthologous re-2/ub2/DC16 (TBC) Rab GTPase-activating proteins TBC-7 and TBC1D15 in and mammalian cells, respectively.

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In multicellular organisms, the cells are surrounded by persistent, dynamic extracellular matrix (ECM), the largest calcium reservoir in animals. ECM regulates several aspects of cell behavior including cell migration and adhesion, survival, gene expression and differentiation, thus playing a significant role in health and disease. Calcium is reported to be important in the assembly of ECM, where it binds to many ECM proteins.

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Appropriate Wnt morphogen secretion is required to control animal development and homeostasis. Although correct Wnt globular structure is essential for secretion, proteins that directly mediate Wnt folding and maturation remain uncharacterized. Here, we report that protein disulfide isomerase-1 (PDI-1), a protein-folding catalyst and chaperone, controls secretion of the Caenorhabditis elegans Wnt ortholog EGL-20.

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The Caenorhabditis elegans (C. elegans) germline is used to study several biologically important processes including stem cell development, apoptosis, and chromosome dynamics. While the germline is an excellent model, the analysis is often two dimensional due to the time and labor required for three-dimensional analysis.

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The Caenorhabditis elegans germline is widely used as a model to study stem cell development, chromosome dynamics and apoptosis. Major readouts of germline phenotypes such as cell counting and protein expression profiling are routinely analyzed manually and in a two-dimensional manner. The major disadvantages of the existing approaches are 1) they are time-consuming and laborious and 2) there is an inability to study the effects of genetic mutations in three dimensions.

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Functional interplay between tumour cells and their neoplastic extracellular matrix plays a decisive role in malignant progression of carcinomas. Here we provide a comprehensive data set of the human HNSCC-associated fibroblast matrisome. Although much attention has been paid to the deposit of collagen, we identify oncofetal fibronectin (FN) as a major and obligate component of the matrix assembled by stromal fibroblasts from head and neck squamous cell carcinomas (HNSCC).

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Cell-extracellular matrix (ECM) and cell-cell junctions that employ microfilaments are sites of tension. They are important for tissue repair, morphogenetic movements and can be emblematic of matrix contraction in fibrotic disease and the stroma of solid tumors. One cell surface receptor, syndecan-4, has been shown to regulate focal adhesions, junctions that form at the ends of microfilament bundles in response to matrix components such as fibronectin.

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Cytosolic calcium is an important factor during fertilization, development and differentiation. Hence, the control of cytosolic calcium levels has been studied extensively for several decades. Numerous calcium channels have been identified and their mechanism of action elucidated.

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Transmembrane heparan sulfate proteoglycans regulate multiple aspects of cell behavior, but the molecular basis of their signaling is unresolved. The major family of transmembrane proteoglycans is the syndecans, present in virtually all nucleated cells, but with mostly unknown functions. Here, we show that syndecans regulate transient receptor potential canonical (TRPCs) channels to control cytosolic calcium equilibria and consequent cell behavior.

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Background: The use of imaging to implement on-treatment adaptation of radiotherapy is a promising paradigm but current data on imaging changes during radiotherapy is limited. This is a hypothesis-generating pilot study to examine the changes on multi-modality anatomic and functional imaging during (chemo)radiotherapy treatment for head and neck squamous cell carcinoma (HNSCC).

Methods: Eight patients with locally advanced HNSCC underwent imaging including computed tomography (CT), Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)-CT and magnetic resonance imaging (MRI) (including diffusion weighted (DW) and dynamic contrast enhanced (DCE)) at baseline and during (chemo)radiotherapy treatment (after fractions 11 and 21).

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Proteoglycans control numerous normal and pathological processes, among which are morphogenesis, tissue repair, inflammation, vascularization and cancer metastasis. During tumor development and growth, proteoglycan expression is markedly modified in the tumor microenvironment. Altered expression of proteoglycans on tumor and stromal cell membranes affects cancer cell signaling, growth and survival, cell adhesion, migration and angiogenesis.

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In the 25 years, as the first of the syndecan family was cloned, interest in these transmembrane proteoglycans has steadily increased. While four distinct members are present in mammals, one is present in invertebrates, including C. elegans that is such a powerful genetic model.

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