Publications by authors named "Kelavkar U"

Background Proximal radial artery (pRA) access for cardiac catheterization is safe but can jeopardize subsequent use of the artery because of occlusion. Distal radial artery (dRA) access in the anatomical snuffbox preserves the radial artery, but safety and potential detrimental effects on hand function are unknown. Methods and Results In the DIPRA (Distal Versus Proximal Radial Artery Access for Cardiac Catheterization and Intervention) study, a single-center trial, 300 patients were randomized 1:1 to cardiac catheterization through dRA or pRA.

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Background: Epidemiological data suggest that omega-6 (ω-6) fatty acids (FAs) may be associated with cancer incidence and/or cancer mortality, whereas ω-3 FAs are potentially protective. We examined the association of the ratio of ω-6 to ω-3 FA (ω-6:ω-3) and individual FA components with pathological results among men with prostate cancer (PCa) undergoing radical prostatectomy.

Methods: Sixty-nine men were included in the study.

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Hypoxia-inducible factor 1α (HIF-1α) is the regulatory subunit of the heterodimeric HIF-1 that plays a critical role in transcriptional regulation of genes in angiogenesis and hypoxic adaptation, while fatty acid metabolism mediated by lipoxygenases has been implicated in a variety of pathogeneses, including cancers. In this study, we report that 15-lipoxygenase 1 (15-LO1), a key member of the lipoxygenase family, promotes HIF-1α ubiquitination and degradation. Altering the level of 15-LO1 yields inverse changes in HIF-1α and HIF-1 transcriptional activity, under both normoxia and hypoxia, and even in CoCl2 -treated cells where HIF-1α has been artificially elevated.

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Background: The results of prostate specific antigen (PSA) and digital rectal examination (DRE) screenings lead to both under and over treatment of prostate cancer (PCa). As such, there is an urgent need for the identification and evaluation of new markers for early diagnosis and disease prognosis. Studies have shown a link between PCa, lipids and lipid metabolism.

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Docosapentaenoic acid (DPA) is a unique fatty acid that exists in two isomeric forms (n-3 and n-6), which differ in their physiological behaviors. DPA can undergo free radical-mediated peroxidation via lipoxygenase (LOX). 15-LOX, one of the LOX isomers, has received much attention in cancer research because of its very different expression level in normal tissues compared to tumors and some bioactive fatty acid metabolites modulating the tumorigenic pathways in cancer.

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The main objectives of our study were to determine the bioavailability of omega-3 (omega-3) to the tumor, to understand its mechanisms, and to determine the feasibility of targeting the omega-6 polyunsaturated fatty acids (PUFAs) metabolizing 15-lipoxygenase-1 (15-LO-1) and cyclooxygenase-2 (COX-2) pathways. Nude mice injected subcutaneously with LAPC-4 prostate cancer cells were randomly divided into three different isocaloric (and same percent [%] of total fat) diet groups: high omega-6 linoleic acid (LA), high omega-3 stearidonic acid (SDA) PUFAs, and normal (control) diets. Tumor growth and apoptosis were examined as end points after administration of short-term (5 weeks) omega-3 and omega-6 fatty acid diets.

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Diets high in fat seem to correspond with an increased risk of certain forms of cancer, including bladder BlCa. This preliminary study examined the expression and enzyme activity profile of the polyunsaturated fatty acid metabolizing enzyme 15-Lipoxygenase-1 (15-LO-1) in human tissues from normal bladder and bladder tumors (stages CIS-T3/T4). Human tissue samples from normal (donor) bladder and bladder tumors (stages CIS-T3/T4; non-Bacillus Calmette-Guerin-treated) were grossly microdissected and analyzed for 15-LO-1 protein expression [immunohistochemistry (IHC)/Western blot], mRNA expression (quantitative real-time polymerase chain reaction) and enzyme activity profiles.

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Fifteen (15)-lipoxygenase type 1 (15-LO-1, ALOX15), a highly regulated, tissue- and cell-type-specific lipid-peroxidating enzyme has several functions ranging from physiological membrane remodeling, pathogenesis of atherosclerosis, inflammation and carcinogenesis. Several of our findings support a possible role for 15-LO-1 in prostate cancer (PCa) tumorigenesis. In the present study, we identified a CpG island in the 15-LO-1 promoter and demonstrate that the methylation status of a specific CpG within this island region is associated with transcriptional activation or repression of the 15-LO-1 gene.

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The lipid-peroxidating enzyme, 15-lipoxygenase (LO)-1 and its metabolite, 13-S-hydroxyoctadecadienoic acid (13-S-HODE), likely contribute to prostate tumorigenesis. Thus, this study evaluated adenovirus-mediated overexpression of 15-LO-1 on normal mouse prostate. Adenovirus expressing either human 15-LO-1 tagged with green fluorescent protein (GFP) or GFP alone was orthotopically injected into the dorsolateral prostates of C57BL/6 mice, three times over the course of 60 days.

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The incidence and mortality of prostate cancer (PCa) vary greatly in different geographic regions, for which lifestyle factors, such as dietary fat intake, have been implicated. Human 15-lipoxygenase-1 (h15-LO-1), which metabolizes polyunsaturated fatty acids, is a highly regulated, tissue-specific, lipid-peroxidating enzyme that functions in physiological membrane remodeling and in the pathogenesis of atherosclerosis, inflammation, and carcinogenesis. We have shown that aberrant overexpression of 15-LO-1 occurs in human PCa, particularly high-grade PCa, and in high-grade prostatic intraepithelial neoplasia (HGPIN), and that the murine orthologue is increased in SV40-based genetically engineered mouse (GEM) models of PCa, such as LADY and TRansgenic Adenocarcinoma of Mouse Prostate.

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Evidence indicates that a diet rich in omega (omega)-6 polyunsaturated fatty acids (PUFAs) [e.g., linoleic acid (LA)] increases prostate cancer (PCa) risk, whereas a diet rich in omega-3 decreases risk.

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One of the major components in high-fat diets (Western diet) is the omega (omega, n)-6 polyunsaturated fatty acid (PUFA) called linoleic acid (LA). Linoleic acid is the precursor for arachidonic acid (AA). These fatty acids are metabolized to an array of eicosanoids and prostaglandins depending upon the enzymes in the pathway.

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Changes in the expression and activity of lipid-metabolizing enzymes, including the linoleic acid (LA)-metabolizing enzyme 15-lipoxygenase-1 (15-LO-1), may play a role in the development and progression of human prostate carcinoma (PCa). We reported that human 15-LO-1 (designated as leukocyte type 12-LO or 12/15-LO in mouse) is expressed in human prostate and increased in PCa, particularly high-grade PCa. Genetically engineered mouse (GEM) models of PCa could facilitate the study of this gene and its regulation and function in PCa progression.

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We previously discovered that a fat-metabolizing enzyme, 15-lipoxygenase-1 (15-LO-1), is high in human prostate cancer (PCa) and correlates with disease progression. The biologic link between the aberrant 15-LO-1/linoleic acid (LA) metabolism and fat (which is a rich source of growth factors) in PCa is unknown. Therefore, we tested the hypothesis that the metabolic product of the polyunsaturated fatty acid LA (i.

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Background: The binding of 5-lipoxygenase (5-LO) to 5-LO activating protein (FLAP) is a prerequisite for subsequent formation of leukotrienes from arachidonic acid.

Methods: We investigated the localization of FLAP in a rat model of accelerated anti-glomerular basement membrane nephritis and protein expression in cultured rat glomerular endothelial cells.

Results: As expected, 5-LO staining was intense and localized exclusively to perinuclear region and inside the nucleus of leukocytes and macrophages.

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Lipoxygenases oxidatively metabolize polyunsaturated fatty acids to a rich spectrum of biologically active products. One enzyme of the lipoxygenase family, Arachidonate 15-lipoxygenase-1 (arachidonate:oxygen 15-oxidoreductase, EC 1.13.

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The effect of overexpression of 15-lipoxygenase-1 (15-LO-1) was studied in the human prostate cancer cell line, PC-3. Stable PC-3 cell lines were generated by transfection with 15-LO-1-sense (15-LOS), 15-LO-1-antisense (15-LOAS) or vector (Zeo) and selection with Zeocin. After characterization by RT-PCR, western and HPLC, a PC3-15LOS clone was selected that possessed 10-fold 15-LO-1 enzyme activity compared with parental PC-3 cells.

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As reported previously in human monocytes, a human lung epithelial cell line, A549, showed de novo induction of 15-Lipoxygenase-1 (15-LO-1) in response to interleukins-13 (IL-13) and -4 (IL-4). In this cell line, 15-LO-1 expression, by RT-PCR and western blotting, was observed following 6 and 24 h of exposure to human IL-13 (ED50 5 ng/ml) and IL-4 (ED50 0.2 ng/ml).

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15-Lipoxygenase-1 (15-LO-1) is expressed at higher levels in human colorectal tumors compared with normal tissue. 15-LO-1 is expressed in cultured human colorectal cells, but only after treatment with sodium butyrate (NaBT), which also stimulates apoptosis and cell differentiation. We examined the regulation of 15-LO-1 in human tissue and the colorectal carcinoma cell lines Caco-2 and SW-480 by treatment with histone deacetylase (HDAC) inhibitors: NaBT, trichostatin A (TSA) and HC toxin.

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We recently reported that the mutant form of the tumor-suppressor gene p53 up-regulates 15-LO-1 gene expression in a murine cell line. Here, we examine the expression of 15-lipoxygenase (LO)-1 and mutant p53 (mtp53) in human prostatic tissues and 15-LO-1 in the human prostate adenocarcinoma cell line PC-3. Reverse transcription-PCR and western analyses conclusively demonstrated expression of 15-LO-1 in PC-3 cells.

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The data presented implicate a GATA binding site in the transcriptional regulation of 15-lipoxygenase-1 (15-LO-1) gene expression in human colorectal carcinoma Caco-2 cells. High expression of GATA-6 mRNA and protein was observed, while GATA-4 mRNA was expressed at a very low level in Caco-2 cells. The expression of GATA-6 was down-regulated, while 15-LO-1 expression was dramatically up-regulated after treatment with sodium butyrate (NaBT).

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