Heat shock protein 72 (Hsp72) inhibits apoptosis induced by some stresses that trigger the intrinsic apoptosis pathway. However, with the exception of TNFalpha-induced apoptosis, a role for Hsp72 in modulating the extrinsic pathway of apoptosis has not been clearly established. In this study, it was demonstrated that Hsp72 could inhibit Fas-mediated apoptosis of type II CCRF-CEM cells, but not type I SW480 or CH1 cells.
View Article and Find Full Text PDFThe effect of 2-nitropropanol (2NPOH) administration on Salmonella enterica serovar Typhimurium in experimentally infected chicks was determined. Chicks orally challenged with 10(6) CFU/ml of a novobiocin- and naladixic acid-resistant Salmonella Typhimurium at 6 days of age were divided into three groups receiving 0 (control), 6.5, and 13 mg 2NPOH per bird (experiment 1) or four groups receiving 0 (control), 13, 65, and 130 mg 2NPOH per bird (experiment 2).
View Article and Find Full Text PDFHsp72 protects cells against apoptosis in response to various stresses. By simultaneously measuring cytochrome c localization and nuclear morphology in mouse embryo fibroblasts, we have shown that Hsp72 blocks cytochrome c release from mitochondria in response to cytotoxic stress and that permeabilization of the outer mitochondrial membrane is the critical point in deciding the fate of the cell. Hsp72 did not inhibit apoptosis in mouse embryo fibroblasts once cytochrome c had been released from the mitochondria.
View Article and Find Full Text PDFCaveolin-1 was identified in a screen for genes involved in breast cancer progression. Caveolin-1 is the major protein component of caveolae, flask-shaped invaginations found in a number of different cell types. Using an orthotopic model of spontaneous breast cancer metastasis, caveolin-1 was found to be expressed in low and non-metastatic primary tumors, but at much lower levels in highly metastatic 4T1.
View Article and Find Full Text PDFThe objective of the present study was to determine the prevalence of intestinal Campylobacter in lactating dairy cows from various regions of the United States. Participating commercial dairy farms were chosen at random and were part of a national survey to determine E. coli O157:H7 and Salmonella prevalence in dairy cows.
View Article and Find Full Text PDFThe plasminogen-activating (PA) and matrix metalloproteinase (MMP) enzyme systems are implicated in proteolytic turnover of the extracellular matrix (ECM) associated with biologic processes including wound healing, inflammation and angiogenesis. Aberrant expression of components of the PA and MMP enzyme systems occurs in the pathogenesis of metastatic cancer. Oxamflatin (Ox), a novel hydroxamic acid derivative, inhibits u-PA mRNA expression and proteolytic activity while simultaneously upregulating the expression of the natural inhibitor of u-PA, plasminogen activator inhibitor type 2 (PAI-2) in metastatic cancer cells.
View Article and Find Full Text PDFIn 1989, the tailings pond dam at the site of a former copper mine near Little Bay, Newfoundland and Labrador, Canada, ruptured and tailings spilled into Little Bay Arm. At the time, no action was taken to arrest the flow of tailings or to mitigate the effects of the spill. To date, no action has been taken to repair the dam and tailings continue to flow into Little Bay Arm.
View Article and Find Full Text PDFMethane production by ruminal microbes during the digestion of feedstuffs is an inefficient process resulting in losses of 2-12% of the gross energy consumed by ruminants. Presently, we report the effect of three inhibitors on ruminal methane production in vitro. Mixed populations of ruminal microbes collected from cannulated cows maintained on an alfalfa hay:corn diet (50:50) were incubated at 39 degrees C for 24 h under a 100% carbon dioxide gas phase in closed tubes with 72 mM added sodium formate.
View Article and Find Full Text PDFThe effects of two feed supplements on Salmonella Typhimurium in the ceca of market-age broilers were determined. Broilers orally challenged 6 days before slaughter with a novobiocin- and nalidixic acid-resistant strain of Salmonella Typhimurium were divided into one of four groups (20 birds each). The first group (the control group) received no treatment, the second group received sodium nitrate (SN) treatment (574 mg of NaNO3 per kg of feed), the third group received experimental chlorate product (ECP) treatment (15 mM NaClO3 equivalents), and the fourth group received ECP treatment in combination with SN treatment.
View Article and Find Full Text PDFA competitive exclusion (CE) culture of porcine cecal bacteria was developed as a continuous-flow culture in chemostats, was designated RPCF, and was used as a model to determine its usefulness against in vitro colonization by Salmonella enterica serovars Typhimurium and Choleraesuis, Escherichia coli strain F-18, and E. coli serotype O157:H7 (933). Chemostats with or without RPCF were inoculated with 10(6) colony-forming units (CFU)/ml of Typhimurium, Choleraesuis, F-18, or O157:H7.
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