Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine最新文献

{"title":"Peptide YY stimulates the expression of apolipoprotein A-IV gene in Caco-2 intestinal cells.","authors":"K. Sonoyama, K. Suzuki, T. Kasai","doi":"10.1111/J.1525-1373.2000.22338.X","DOIUrl":"https://doi.org/10.1111/J.1525-1373.2000.22338.X","url":null,"abstract":"The effect of peptide YY, a gastrointestinal hormone, on the expression of the apolipoprotein A-IV gene in the intestinal epithelial cell line Caco-2 was examined by semiquantitative RT-PCR followed by Southern hybridization with an inner oligonucleotide probe. Apolipoprotein A-IV mRNA levels were increased in response to peptide YY in a dose- and time-dependent fashion. Western blotting revealed that the exogenous peptide YY increased the intracellular concentration of apolipoprotein A-IV. In contrast, apolipoprotein A-I, B, and C-III mRNA did not respond to peptide YY. Differentiated Caco-2 cells expressed Y1- but not Y2- and Y5-receptor subtype mRNA. The present results suggest that peptide YY modulates apolipoprotein A-IV gene expression, likely via the Y1-receptor subtype in intestinal epithelial cells.","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73762817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transport of toxic heavy metals across cell membranes.","authors":"E. Foulkes","doi":"10.1111/J.1525-1373.2000.22334.X","DOIUrl":"https://doi.org/10.1111/J.1525-1373.2000.22334.X","url":null,"abstract":"Membrane transport of nonessential toxic heavy metals (type D heavy metals) not only controls their access to intracellular target sites but also helps determine their uptake, distribution, and excretion from the body. The critical role of membranes in the toxicology of class D metals has attracted the attention of many investigators, and extensive information has been collected on the mechanism(s) of metal transfer across membranes. Characteristics of metal transport in different cells, or even on opposite sides of the same cell, or under different physiological conditions, are not identical, and no unitary hypothesis has been formulated to explain this process in all cells. However, it seems possible that the mechanisms proposed for different cells represent variations on a few common themes.","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89255440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitroprusside attenuates myocardial stunning through reduced contractile delay and time.","authors":"R. Leone, P. Scholz, H. Weiss","doi":"10.1111/J.1525-1373.2000.22337.X","DOIUrl":"https://doi.org/10.1111/J.1525-1373.2000.22337.X","url":null,"abstract":"We hypothesized that myocardial stunning would be reversed through increased cyclic GMP caused by nitroprusside, and that this would be accomplished through a decreased proportion of regional work during diastole. Hearts were instrumented to measure left ventricular pressure, and regional myocardial mechanics were recorded using a miniature force transducer and ultrasonic dimension crystals in eight open-chest anesthetized dogs. Following baseline (CON), the left anterior descending coronary artery (LAD) was occluded for 15 min, followed by a 30-min recovery (STUN). Then intracoronary LAD infusion of sodium nitroprusside (NP) (4 microg/kg/ min) was begun. The time delay (msec) to regional shortening increased significantly from 18+/-13 to 73+/-13 following stunning, but was reduced to 49+/-18 by NP. Total regional work (g*mm/min) at baseline (1368+/-401 CON) was unchanged with stunning (1320+/-333 STUN), but reduced (961+/-240) following NP. Time to peak force development (msec) increased significantly with stunning from 284+/-13 (CON) to 333+/-11 (STUN), but was reduced to 269+/-12 following NP. The percentage work during systole was reduced from 96%+/-2% (CON) to 77%+/-7% (STUN), but returned to 98%+/-1% with NP. Regional O2 consumption was unaffected by either treatment. Cyclic GMP was unchanged by stunning (2.9+/-0.3-2.9+/-0.4 pmol/g) but increased significantly with NP (4.6+/-0.6). These data indicated that regional myocardial stunning could be attenuated by nitroprusside, which increased cyclic GMP, decreased contractile delay, increased the proportion of work done during systole, and reduced time of shortening.","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88473775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduction to editorials on crises in academic medicine: diagnoses and treatments","authors":"Knopp, Bartke","doi":"10.1111/J.1525-1373.2000.22331.X","DOIUrl":"https://doi.org/10.1111/J.1525-1373.2000.22331.X","url":null,"abstract":"","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77341168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tumor necrosis factor (TNF)-alpha and TNF receptors in viral pathogenesis.","authors":"Georges Herbein, William A. O'Brien","doi":"10.1046/J.1525-1373.2000.22335.X","DOIUrl":"https://doi.org/10.1046/J.1525-1373.2000.22335.X","url":null,"abstract":"Tumor necrosis factor-alpha (TNF-alpha) and TNF receptors (TNFR) are members of the growing TNF ligand and receptor families that are involved in immune regulation. The present report will focus on the role of the prototypic ligand TNF and its two receptors, TNFR1 and TNFR2, in viral pathogenesis. Although TNF was reported years ago to modulate viral infections, recent findings on the molecular pathways involved in TNFR signaling have allowed a better understanding of the molecular interactions between cellular and viral factors within the infected cell. The interactions of viral proteins with intracellular components downstream of the TNFR have highlighted at the molecular level how viruses can manipulate the cellular machinery to escape the immune response and to favor the spread of the infection. We will review here the role of TNF and TNFR in immune response and the role of TNF and TNFR signaling in viral pathogenesis.","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89162464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beta-adrenergic agonist hyperplastic effect is associated with increased fibronectin gene expression and not mitogen-activated protein kinase modulation in C2C12 cells.","authors":"E. Izevbigie, W. Bergen","doi":"10.1111/J.1525-1373.2000.22343.X","DOIUrl":"https://doi.org/10.1111/J.1525-1373.2000.22343.X","url":null,"abstract":"Beta-adrenergic agonists (beta-AA) enhance protein accretion in skeletal muscles. This stimulation is characterized by increased protein synthesis, increased expression of myofibrillar protein genes and a depression in protein degradation in animals, and increased proliferation and DNA synthesis in muscle cells in vitro. The mechanism or signal path in muscle whereby beta-AA would elicit these physiological effects upon binding to the G protein-coupled beta-adrenergic receptor (beta-AR) is unclear. C2C12 myoblasts were used to determine beta-AR ligand binding characteristics, cyclic AMP synthesis in response to isoproterenol (ISO) stimulation, and effects of ISO on DNA synthesis, mitogen activated protein kinase (MAPK), and fibronectin (FN) gene expression. Results showed that C2C12 cells possess beta-AR which are specific, saturable, and of high affinity (Kd = 0.2 nM). Forskolin and ISO stimulated cAMP production by = 20-fold (P<0.001) and 17-fold (P<0.001), respectively. ISO and the cAMP analog, 8-bromo-cAMP (8-BC) stimulated DNA synthesis in proliferating cells by 150% (P<0.05) and 200% (P<0.01), respectively, without modulating MAPK activity, whereas addition of fetal bovine serum to culture resulted in a 500% increase (P<0.01) in DNA synthesis and MAPK activation. DNA synthesis in C2C12 cells treated with ISO, 8-BC, or FBS was abolished in the presence of 25 microM PD098059, an MAPK-kinase inhibitor, suggesting that an MAPK-dependent pathway is likely involved in C2C12 proliferation. During cAMP elevating agent stimulation, basal MAPK activity may be sufficient, in the presence of other putative signaling molecules, to support proliferation in these cells. ISO or 8-BC treatment increased FN mRNA by three- and seven-fold, respectively, in growing C2C12 cells implying a connection between increased DNA synthesis and FN gene expression.","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90340599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent developments in the virus therapy of cancer.","authors":"Timothy A. Steele","doi":"10.1111/J.1525-1373.2000.22317.X","DOIUrl":"https://doi.org/10.1111/J.1525-1373.2000.22317.X","url":null,"abstract":"Cancer is one of the leading causes of death in the United States. Although there has been significant progress in the areas of cancer etiology, diagnostic techniques, and cancer prevention, adequate therapeutic approaches for many cancers have lagged behind. One promising line of investigation is the virus therapy of cancer. This approach entails the use of viruses, such as retroviruses, adenovirus, and vaccinia virus, to modify tumor cells so that they become more susceptible to being killed by the host immune response, chemotherapeutic agents, or programmed cell death. This review discusses recent advances in the virus therapy of cancer from both basic science and clinical perspectives. Given the potential of viruses to kill tumor cells directly or transduce desired gene products to allow a vigorous host antitumor immune response, the virus therapy of cancer holds great promise in the treatment of cancer.","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87845880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mediators and mechanisms of radiation nephropathy.","authors":"E. Cohen, S. Bonsib, E. Whitehouse, J. Hopewell, M. Robbins","doi":"10.1111/J.1525-1373.2000.22330.X","DOIUrl":"https://doi.org/10.1111/J.1525-1373.2000.22330.X","url":null,"abstract":"Normal tissue radiation injury occurs after sufficient irradiation, thus limiting the curative potential of x-ray therapy. In the kidney, radiation injury results in fibrosis and, ultimately, renal failure. The mediators of fibrosis in radiation nephropathy have received scant attention. Therefore, we evaluated the sequential presence of alpha smooth muscle actin (alphasma), fibrin, collagen, and TGFbeta1 in a porcine model of radiation nephropathy using 9.8 Gy single-dose local kidney irradiation. During the 24-week study, there was progressive and significant collagen accumulation in glomeruli and in interstitium. In glomeruli, this was associated with significant mesangial alphasma expression by 2 weeks after irradiation, a further rise at 4 weeks, and then a gradual fall to baseline. Glomerular fibrin deposition was significant by 4 weeks after irradiation, and remained elevated thereafter. There was little or no glomerular TGFbeta1 expression at any time point. Tubular fibrin deposition was significant at 4 weeks after irradiation but declined thereafter. There was little or no tubulo-interstitial alphasma expression at any time after irradiation. At 6 weeks after irradiation, there was a significant peak of tubular epithelial TGFbeta1 expression that declined thereafter. The early glomerular injury is evident as mesangial alphasma expression but is not proceeded by TGFbeta1 expression. There is sustained glomerular fibrin deposition with deposition of fibrin in tubular lumens, suggesting that tubular fibrin derives and flows out from injured glomerular tufts. We conclude that i) alphasma expression is an early marker of glomerular radiation injury, presaging scarring; ii) fibrin deposition is involved in glomerular and tubular radiation injury; and iii) TGFbeta1 is not an early event in radiation nephropathy, and not apparent in glomeruli in this model, but may correlate with later tubulo-interstitial fibrosis. Thus, the mediators of scarring in this model differ according to time after injury and also according to the affected tissue compartment.","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82061992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microfilament network is needed for the endocytosis of water channels and not for apical membrane insertion upon vasopressin action.","authors":"A. Dibas, Abdul Mia, T. Yorio","doi":"10.1111/J.1525-1373.2000.22328.X","DOIUrl":"https://doi.org/10.1111/J.1525-1373.2000.22328.X","url":null,"abstract":"In the current study, a novel role for the microfilaments in vasopressin-induced water transport in toad urinary bladders, a popular model for the mammalian collecting duct, was established. Vasopressin-induced water transport was not affected by cytochalasin D (CD, 20 microM) or latrunculin B (Lat B, 0.5-2 microM), microfilament-disrupting reagents, suggesting that the initial trafficking of vesicles containing water channels and insertion of membranes into the apical membrane are microfilament-independent. After the removal of vasopressin, bladders treated with CD or Lat B continued to transport water at least 2-3-fold greater than those that received the vehicle. Furthermore, the enhanced water transport was inhibited by HgCl2 (1 mM), a potent inhibitor of water channel-mediated water flow, suggesting that the enhanced water flow was through water channels. In addition, Lat B and CD inhibited vasopressin-induced endocytosis of horseradish peroxidase (HRP), a fluid endocytotic marker. These results suggested that although microfilaments are not needed for the initial trafficking of water channels to the apical side, the microfilament network is essential for the retrieval of water channels following their insertion into apical membranes.","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86050666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regional fat deposition in the legs is useful as a presumptive marker of antiatherogenesity in Japanese.","authors":"M. Tatsukawa, M. Kurokawa, Y. Tamari, H. Yoshimatsu, T. Sakata","doi":"10.1111/J.1525-1373.2000.22321.X","DOIUrl":"https://doi.org/10.1111/J.1525-1373.2000.22321.X","url":null,"abstract":"To examine the pathological role of regional fat deposition in development of metabolic and cardiovascular disorders, regional fat distribution was evaluated using metabolites and hormones as measures of obesity-related disorders. The subjects enrolled were 100 sex-matched inpatients, who were admitted, regardless of their body mass index values, for further examination of unusual results from periodic medical screening tests, and for examination of obesity-induced complications and treatment of obesity. Body fat distribution was analyzed using dual energy X-ray absorptiometry (DEXA). Analysis of parameters regarding fat distribution showed that gender was one of the determinants affecting correlation between fat distribution and metabolites of fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), total cholesterol (TC), or triglyceride (TG). However, regardless of gender, both leg trunk fat (L/Tr) and arm trunk fat (A/Tr) ratios negatively correlated with a total body fat (% total fat) ratio, whereas the intercept value of female regression line in L/Tr was greater than that in males, but not in A/Tr. Percentage total fat, L/Tr, and A/Tr in males correlated significantly with FPG, TC, TG, low-density lipoprotein (LDL), very low density lipoprotein (VLDL), atherogenic index (A.I.), and apoB/A1 only low density lipoprotein (LDL) was significantly correlated solely to L/Tr and A/Tr. These results indicate that regional fat distribution in males may not be a major determinant for development of metabolic disorders in obese patients. Unlike male regional fat distribution, female L/Tr correlated significantly not only with TC, TG, and LDL, but also with FPG and HbA1c, although both of the latter 2 glucose-related parameters in males showed no correlation with any parameters of fat deposition. The remaining female parameters of fasting plasma insulin, VLDL, A.I., and ApoB/A1 correlated with each of the three parameters of fat deposition, as similarly shown in males. The powerful and negative correlation was thus evident, particularly in females, between leg fat deposition and parameters of glucose and lipid metabolites. The resulting information provides a novel insight that regional fat deposition at the legs is useful as a marker for metabolic and cardiovascular disorders associated with obesity.","PeriodicalId":20618,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89414598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}