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981.
982.
Shepard LW Yang M Xie P Browning DD Voyno-Yasenetskaya T Kozasa T Ye RD 《The Journal of biological chemistry》2001,276(49):45979-45987
The Kaposi's sarcoma herpesvirus (KSHV) open reading frame 74 encodes a G protein-coupled receptor (GPCR) for chemokines. Exogenous expression of this constitutively active GPCR leads to cell transformation and vascular overgrowth characteristic of Kaposi's sarcoma. We show here that expression of KSHV-GPCR in transfected cells results in constitutive transactivation of nuclear factor kappa B (NF-kappa B) and secretion of interleukin-8, and this response involves activation of G alpha(13) and RhoA. The induced expression of a NF-kappa B luciferase reporter was partially reduced by pertussis toxin and the G beta gamma scavenger transducin, and enhanced by co-expression of G alpha(13) and to a lesser extent, G alpha(q). These results indicate coupling of KSHV-GPCR to multiple G proteins for NF-kappa B activation. Expression of KSHV-GPCR led to stress fiber formation in NIH 3T3 cells. To examine the involvement of the G alpha(13)-RhoA pathway in KSHV-GPCR-mediated NF-kappa B activation, HeLa cells were transfected with KSHV-GPCR alone and in combination with the regulator of G protein signaling (RGS) from p115RhoGEF or a dominant negative RhoA(T19N). Both constructs, as well as the C3 exoenzyme from Clostritium botulinum, partially reduced NF-kappa B activation by KSHV-GPCR, and by a constitutively active G alpha(13)(Q226L). KSHV-GPCR-induced NF-kappa B activation is accompanied by increased secretion of IL-8, a function mimicked by the activated G alpha(13) but not by an activated G alpha(q)(Q209L). These results suggest coupling of KSHV-GPCR to the G alpha(13)-RhoA pathway in addition to other G proteins. 相似文献
983.
DAMBE (data analysis in molecular biology and evolution) is an integrated software package for converting, manipulating, statistically and graphically describing, and analyzing molecular sequence data with a user-friendly Windows 95/98/2000/NT interface. DAMBE is free and can be downloaded from http://web.hku.hk/~xxia/software/software.htm. The current version is 4.0.36. 相似文献
984.
Herrera VL Makrides SC Xie HX Adari H Krauss RM Ryan US Ruiz-Opazo N 《Nature medicine》1999,5(12):1383-1389
The acceleration of atherosclerosis by polygenic (essential) hypertension is well-characterized in humans; however, the lack of an animal model that simulates human disease hinders the elucidation of pathogenic mechanisms. We report here a transgenic atherosclerosis-polygenic hypertension model in Dahl salt-sensitive hypertensive rats that overexpress the human cholesteryl ester transfer protein (Tg[hCETP]DS). Male Tg[hCETP]DS rats fed regular rat chow showed age-dependent severe combined hyperlipidemia, atherosclerotic lesions, myocardial infarctions and decreased survival. These findings differ from various mouse atherosclerosis models, demonstrating the necessity of complex disease modeling in different species. The data demonstrate that cholesteryl ester transfer protein can be proatherogenic. The interaction of polygenic hypertension and hyperlipidemia in the pathogenesis of atherosclerosis in Tg[hCETP]DS rats substantiates epidemiological observations in humans. 相似文献
985.
Neuroprotection by pramipexole against dopamine- and levodopa-induced cytotoxicity 总被引:14,自引:0,他引:14
Pramipexole, a novel non-ergoline dopamine (DA) agonist, has been applied successfully for treatment of Parkinson's disease (PD). We report here that pramipexole can protect dopaminergic cell line Mes23.5 against dopamine- and levodopa-induced cytotoxicity possibly through a mechanism related to antioxidant activity. In the MES 23.5 cultures, DA and L-DOPA induce a dose- and time-dependent cytotoxicity, as determined by tetrazolium salt and trypan blue assays. Furthermore, an in situ terminal deoxynucleotidyl transferase assay demonstrates that DA-induced cell death is apoptotic. Pretreatment with pramipexole in a concentration range (4-100 microM) significantly attenuates DA- or L-DOPA-induced cytotoxicity and apoptosis, an action which is not blocked by D3 antagonist U-99194 A or D2 antagonist raclopride. Pramipexole also protects MES 23.5 cells from hydrogen peroxide-induced cytotoxicity in a dose-dependent manner. In cell-free system, pramipexole can effectively inhibit the formation of melanin, an end product resulting from DA or L-DOPA oxidation. These results indicate that pramipexole exerts its neuroprotective effect possibly through a mechanism, which is independent of DA receptors but related to antioxidation or scavenging of free radicals (e.g. hydrogen peroxide). As a direct DA agonist and potentially neuroprotective agent, pramipexole remains attractive in the treatment of PD. 相似文献
986.
Fifteen Cases of Penicilliosis in Guangdong,China 总被引:7,自引:0,他引:7
We analyzed the occurrence, clinical and physical features, laboratory findings, diagnostic criteria, reaction to therapy and prognosis of 15 cases Penecilliosis marneffei. Four were localized infection on skin, eleven were systemic infection, all cases were found in Guangdong province of China. We found that males were predominant in infection compared with females in 15 patients, and all patients observed had different occupations. The patients with AIDS as underlying disease were commonly drivers or unemployed. Thirteen of 15 patients had underlying diseases, i.e., connective tissue disease, aplastic anemia, kidney transplant, AIDS. Clinical features showed different symptoms, including weight loss, high fever, skin lesions, and respiratory system symptoms. Seven of 15 patients received antifungal therapy, the remaining eight patients did not receive therapy for different reasons. Nine of the patients died five recovered. Fifteen isolates were cultured from skin lesions, blood, bone marrow, peritoneum dialysis and pleural effusion and were confirmed to be Penicillium marneffei by morphology, thermal dimorphism, pathology and DNA sequence analysis. This report indicates that Penicillium marneffei may exist in nature in Guangdong province of SE China. 相似文献
987.
Liguang?SunEmail author Xiaodong?Liu Xuebin?Yin Renbin?Zhu Zhouqing?Xie Yuhong?Wang 《Polar Biology》2004,27(8):495-501
The historical seal populations at King George Island, Antarctica, for the past 1,500 years, have been
estimated from the seal-hair abundance, bio-element concentrations, total organic carbon (TOC) and total nitrogen (TN) in one terrestrial sediment sequence influenced by seal excrement. Prior to human interference, the seal populations exhibited dramatic fluctuations with two peaks during 750–500 and 1400–1100 years before present (yr B.P.) and two troughs during 1100–750 and 500–200 yr B.P. A tentative comparison of the seal populations and historical climates in the Antarctic Peninsula region suggests that the seal populations may be linked to climate-related factors such as sea-ice coverage and atmospheric temperature. 相似文献
988.
Myocardial dysfunction leading to dilated cardiomyopathy has been documented with surprisingly high frequency in human immunodeficiency virus (HIV)-infected individuals. p38 MAP kinase has been implicated as a mediator of myocardial dysfunction. We previously reported p38 MAP kinase activation by the HIV coat protein gp120 in neonatal rat cardiac myocytes. We now report the direct inotropic effects of HIV gp120 on adult rat ventricular myocytes (ARVM). ARVM were continuously superfused with gp120, and percent fractional shortening (FS) was determined by automated border detection and simultaneous intracellular ionized free Ca2+ concentration ([Ca2+]i) measured by fura 2-AM fluorescence: gp120 alone increased FS and increased [Ca2+]i within 5 min and then depressed FS without a decrease in [Ca2+]i by 2060 min, which persisted for at least 2 h. Exposure of ARVM to gp120 also resulted in the phosphorylation of the upstream regulator of p38 MAP kinase MKK3/6, p38 MAP kinase itself, and its downstream effector, ATF-2, over a similar time course. ERK (p44/42) and JNK stress signaling pathways were not similarly activated. The effects of the p38 MAP kinase inhibitor were concentration dependent. SB-203580 (10 µM) blocked both p38 MAP kinase phosphorylation and the delayed negative inotropic effect of gp120. SB-203580 (5 µM) selectively blocked phosphorylation of ATF-2 without blocking the phosphorylation of MKK3/6 or p38 MAP kinase itself. SB-203580 (5 µM) administered before, with, or after gp120 blocked the negative inotropic effect of gp120 in ARVM. p38 MAP kinase activation may be a common stress-response mechanism contributing to myocardial dysfunction in HIV and other nonischemic as well as ischemic cardiomyopathies. cardiomyopathy; cell signaling 相似文献
989.
Ye F Maegawa H Morino K Kashiwagi A Kikkawa R Xie M Shen Z 《Journal of biochemical and biophysical methods》2004,59(3):201-208
For measuring glutamine:fructose-6-phosphate amidotransferase (GFAT) activity in cultured cells, an enzyme method -GDH method- was set up with high-efficiency, high-sensitivity and simple operation by determining the formed glutamate. During the process of making samples, reduced glutathione (GSH, 5 mM) and glucose-6-phosphate Na2 (5 mM) were added to the buffer for scraping the cells. The range of protein content in the samples was 80-150 microg. In the GFAT activity assay, the end product reduced acetylpyridine adenine dinucleotide (APADH) was determined at 370 nm directly. The suitable concentrations of the reactants fructose-6-phosphate (F-6-P), glutamine, acetylpyridine adenine dinucleotide (APAD) and glutamate dehydrogenase (GDH) were 0.8, 6 and 0.3 mM and 6 U, respectively. However, the excess of APAD may interfere with the APADH measurement. The reaction time course was 90 min. The GFAT activity in 3T3-L1, L6, HepG2 and HIRc cells were 1.84-8.51 nmol glutamate/mg protein.min. 相似文献
990.
Guo T Adang AE Dong G Fitzpatrick D Geng P Ho KK Jibilian CH Kultgen SG Liu R McDonald E Saionz KW Valenzano KJ van Straten NC Xie D Webb ML 《Bioorganic & medicinal chemistry letters》2004,14(7):1717-1720
Potent small molecule biaryl diketopiperazine FSH receptor agonists such as 10c (EC(50)=13 nM) and 11f (EC(50)=1.2 nM) were discovered through the design, synthesis and evaluation of three biaryl diketopiperazine optimization libraries with over 300 compounds. These libraries were prepared via solid-phase parallel synthesis using a cyclization-release method. 相似文献