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41.
两种光敏化合物对斜纹夜蛾超氧物歧化酶影响的比较研究(英文) 总被引:4,自引:0,他引:4
室内测试了斜纹夜蛾Spodoptera litura F. 4龄幼虫超氧物歧化酶的活性,并就α-三噻吩(α-terthienyl)和化合物5,即1-苯基-4-(3,4-亚甲基二氧)苯基-丁二炔等两种光敏化合物对其产生的影响进行了比较研究。结果表明,近紫外光照(300-400nm)基本不影响对照幼虫超氧物歧化酶活体(invivo)活力,但对其离休(in vitro)活力有抑制作用。经光敏化合物处理后,在紫外光照下,超氧物歧化酶活体活力基本不受化合物5的影响,但能被α-三噻吩抑制。离体情况下,两种化合物均促进其活力,α-三噻吩尤甚。表明无论在离体还是活体情况下,幼虫对α-三噻吩均比化合物5具有更高的光敏性。对两种光敏化合物可能的作用机理进行了探讨。 相似文献
42.
43.
Wen‐Yuan Lin F. Xavier Pi‐Sunyer Chiu‐Shong Liu Tsai‐Chung Li Chia‐Ing Li Chih‐Yang Huang Cheng‐Chieh Lin 《Obesity (Silver Spring, Md.)》2009,17(6):1247-1254
Betel nut chewing has been reported to increase the risk of cardiovascular disease and all‐cause mortality. The reason is unclear. In this study, we investigated the association between betel nut chewing and general obesity (BMI ≥25 kg/m2) and central obesity (waist circumference (WC) ≥90 cm). A total of 1,049 male subjects, aged ≥40 years, were recruited from Taichung city in Taiwan in 2004. The relationships between betel nut chewing and general and central obesity were studied by multiple linear and logistic regression analyses. The prevalence of current and former betel nut chewing was 7.0 and 10.5% in our male Taiwanese cohort. Current/former betel nut chewers had a higher prevalence of general and central obesity when compared with individuals who had never chewed betel nut. Adjusted for age, diabetes, hypertension, lipids, smoking, alcohol drinking, physical activity, income, and education level, the odds ratios (ORs; 95% confidence intervals) of general and central obesity among the lower consumption of betel nut chewers were 1.78 (1.07, 2.96) and 1.19 (0.70, 2.02), respectively, compared to 2.01 (1.18, 3.41) and 1.89 (1.10, 3.23), respectively, among higher consumption chewers compared to individuals who had never chewed betel nut. The increasing ORs of general and central obesity with higher betel nut consumption revealed dose–response effects. Using multiple linear regression analyses, after adjusting for potential confounders, betel nut consumption was statistically significantly associated with BMI and WC. In conclusion, betel nut chewing was independently associated with general and central obesity in Taiwanese men. Dose–response effects of the association between betel nut consumption and general obesity as well as central obesity were found. 相似文献
44.
Miyazaki Y Irobalieva RN Tolbert BS Smalls-Mantey A Iyalla K Loeliger K D'Souza V Khant H Schmid MF Garcia EL Telesnitsky A Chiu W Summers MF 《Journal of molecular biology》2010,404(5):751-772
The 5′-untranslated regions of all gammaretroviruses contain a conserved “double-hairpin motif” (ΨCD) that is required for genome packaging. Both hairpins (SL-C and SL-D) contain GACG tetraloops that, in isolated RNAs, are capable of forming “kissing” interactions stabilized by two intermolecular G-C base pairs. We have determined the three-dimensional structure of the double hairpin from the Moloney murine leukemia virus ([ΨCD]2, 132 nt, 42.8 kDa) using a 2H-edited NMR-spectroscopy-based approach. This approach enabled the detection of 1H-1H dipolar interactions that were not observed in previous studies of isolated SL-C and SL-D hairpin RNAs using traditional 1H-1H correlated and 1H-13C-edited NMR methods. The hairpins participate in intermolecular cross-kissing interactions (SL-C to SL-D′ and SLC′ to SL-D) and stack in an end-to-end manner (SL-C to SL-D and SL-C′ to SL-D′) that gives rise to an elongated overall shape (ca 95 Å × 45 Å × 25 Å). The global structure was confirmed by cryo-electron tomography (cryo-ET), making [ΨCD]2 simultaneously the smallest RNA to be structurally characterized to date by cryo-ET and among the largest to be determined by NMR. Our findings suggest that, in addition to promoting dimerization, [ΨCD]2 functions as a scaffold that helps initiate virus assembly by exposing a cluster of conserved UCUG elements for binding to the cognate nucleocapsid domains of assembling viral Gag proteins. 相似文献
45.
Chyi-Huey Bai Jiunn-Rong Chen Hou-Chang Chiu Chia-Chi Chou Lee-Young Chau Wen-Harn Pan 《Journal of biomedical science》2010,17(1):12
Background
The microsatellite polymorphism of heme oxygenase (HO)-1 gene promoter has been shown to be associated with the susceptibility to ischemic event, including coronary artery disease (CAD), myocardial infarction, and peripheral vascular disease. We aimed to examine whether the length of (GT)n repeats in HO-1 gene promoter is associated with ischemic stroke in people with CAD risk factors, especially low level of HDL. 相似文献46.
Chiu-Hsia Chiu Chih-Hsin Cheng Wen-Ren Gua Yuan-Kuang Guu Winton Cheng 《Fish & shellfish immunology》2010,29(6):1053-1059
47.
Zhang R Hryc CF Cong Y Liu X Jakana J Gorchakov R Baker ML Weaver SC Chiu W 《The EMBO journal》2011,30(18):3854-3863
Venezuelan equine encephalitis virus (VEEV), a member of the membrane‐containing Alphavirus genus, is a human and equine pathogen, and has been developed as a biological weapon. Using electron cryo‐microscopy (cryo‐EM), we determined the structure of an attenuated vaccine strain, TC‐83, of VEEV to 4.4 Å resolution. Our density map clearly resolves regions (including E1, E2 transmembrane helices and cytoplasmic tails) that were missing in the crystal structures of domains of alphavirus subunits. These new features are implicated in the fusion, assembly and budding processes of alphaviruses. Furthermore, our map reveals the unexpected E3 protein, which is cleaved and generally thought to be absent in the mature VEEV. Our structural results suggest a mechanism for the initial stage of nucleocapsid core formation, and shed light on the virulence attenuation, host recognition and neutralizing activities of VEEV and other alphavirus pathogens. 相似文献
48.
Cryptomeria japonica is an important plantation conifer tree in Asia. This study aimed to characterize the anti-inflammatory and hepatoprotective activities of the phytocompounds from C. japonica wood on LPS- or TPA-induced activation of proinflammatory mediators and CCl(4)-induced acute liver injury in mice. A CJH7-2 fraction was purified from C. japonica extracts following bioactivity-guided fractionation, and it exhibited significant activities on inhibition of NO production and iNOS expression as well as up-regulating HO-1 expression in LPS-stimulated macrophages. CJH7-2 also potently inhibits COX-2 enzymatic activity (IC(50)=5 microg/mL) and TPA-induced COX-2 protein expression in mouse skin (1mg/200 microL/site). CJH7-2 (10 mg/kg BW) can prevent CCl(4)-induced liver injury and aminotransferases activities in mice. Chemical fingerprinting analysis showed that terpenes are the major bioactive compounds in the CJH7-2 fraction. This is the first study to demonstrate that chemical constituents from the wood extract of C. japonica possess anti-inflammatory activities in vitro and in vivo that may play a role in hepatoprotection. 相似文献
49.
TAB2 and TAB3 activate the NF-kappaB pathway through binding to polyubiquitin chains 总被引:12,自引:0,他引:12
Kanayama A Seth RB Sun L Ea CK Hong M Shaito A Chiu YH Deng L Chen ZJ 《Molecular cell》2004,15(4):535-548
The activation of NF-kappaB and IKK requires an upstream kinase complex consisting of TAK1 and adaptor proteins such as TAB1, TAB2, or TAB3. TAK1 is in turn activated by TRAF6, a RING domain ubiquitin ligase that facilitates the synthesis of lysine 63-linked polyubiquitin chains. Here we present evidence that TAB2 and TAB3 are receptors that bind preferentially to lysine 63-linked polyubiquitin chains through a highly conserved zinc finger (ZnF) domain. Mutations of the ZnF domain abolish the ability of TAB2 and TAB3 to bind polyubiquitin chains, as well as their ability to activate TAK1 and IKK. Significantly, replacement of the ZnF domain with a heterologous ubiquitin binding domain restored the ability of TAB2 and TAB3 to activate TAK1 and IKK. We also show that TAB2 binds to polyubiquitinated RIP following TNFalpha stimulation. These results indicate that polyubiquitin binding domains represent a new class of signaling domains that regulate protein kinase activity through a nonproteolytic mechanism. 相似文献
50.
Yi-Chun Tsai Yi-Wen Chiu Hung-Tien Kuo Szu-Chia Chen Shang-Jyh Hwang Tzu-Hui Chen Mei-Chuan Kuo Hung-Chun Chen 《PloS one》2014,9(11)
Fluid overload is one of the characteristics in chronic kidney disease (CKD). Changes in extracellular fluid volume are associated with progression of diabetic nephropathy. Not only diabetes but also fluid overload is associated with cardiovascular risk factors The aim of the study was to assess the interaction between fluid overload, diabetes, and cardiovascular risk factors, including arterial stiffness and left ventricular function in 480 patients with stages 4–5 CKD. Fluid status was determined by bioimpedance spectroscopy method, Body Composition Monitor. Brachial-ankle pulse wave velocity (baPWV), as a good parameter of arterial stiffness, and brachial pre-ejection period (bPEP)/brachial ejection time (bET), correlated with impaired left ventricular function were measured by ankle-brachial index (ABI)-form device. Of all patients, 207 (43.9%) were diabetic and 240 (50%) had fluid overload. For non-diabetic CKD, fluid overload was associated with being female (β = –2.87, P = 0.003), heart disease (β = 2.69, P = 0.04), high baPWV (β = 0.27, P = 0.04), low hemoglobin (β = –1.10, P<0.001), and low serum albumin (β = –5.21, P<0.001) in multivariate analysis. For diabetic CKD, fluid overload was associated with diuretics use (β = 3.69, P = 0.003), high mean arterial pressure (β = 0.14, P = 0.01), low bPEP/ET (β = –0.19, P = 0.03), low hemoglobin (β = –1.55, P = 0.001), and low serum albumin (β = –9.46, P<0.001). In conclusion, baPWV is associated with fluid overload in non-diabetic CKD and bPEP/bET is associated with fluid overload in diabetic CKD. Early and accurate assessment of these associated cardiovascular risk factors may improve the effects of entire care in late CKD. 相似文献