七星瓢虫的卵黄发生:体外培养的脂肪体中卵黄原蛋白的合成

为了深入研究七星瓢虫的卵黄发生及其激素调节机理,我们建立了脂肪体的体外培养方法,证明了脂肪体在体外培养条件下能够正常进行卵黄原蛋白的合成与分泌。在体外合成的卵黄原蛋白与体内合成的具有相同的电泳迁移率、免疫学特性和部分水解肽谱。放射性氨基酸在体外参人卵黄原蛋白的动力学与在体内的相似。用脂肪体的体外培养方法,结合放射免疫沉淀、SAS-聚丙烯酰胺凝胶电泳、放射自显影等技术,研究了不同发育期脂肪体的合成能力,以及取食人工饲料的雌虫中保幼激素类似物对卵黄原蛋白合成的促进作用。     

Inhibition of yeast tRNATrp aminoacylation by 4-methyltryptophan

The effect of the tryptophan analogue 4-methyltryptophan in Saccharomyces cerevisiae has been investigated. 4-Methyltryptophan inhibits the aminoacylation of tryptophan specific transfer ribonucleic acid (tRNA^Trp). The mode of inhibition is competitive and the analogue is not charged onto tRNA^Trp. Thus 4-methyltryptophan application depletes the cells from charged tRNA^Trp. As a consequence cell growth and protein synthesis are strongly reduced. 4-Methyltryptophan is degraded efficiently in culture media inoculated with the wild type strain; the effects of 4-methyltryptophan were therefore found to be transient.     

The effect of vitamin E analogues and long hydrocarbon chain compounds on calcium-induced muscle damage. A novel role for α-tocopherol?

Previous studies have demonstrated that supplemental α-tocopherol inhibited calcium-induced cytosolic enzyme efflux from normal rat skeletal muscles incubated in vitro and suggested that the protective action was mediated by the phytyl chain of α-tocopherol [1]. In order to investigate this further a number of hydrocarbon chain analogues of tocopherol (7.8-dimethyl tocol, 5,7-dimethyl tocol, tocol, α-tocotrienol, α-tocopherol [10], vitamin K1, vitamin K1 [10], vitamin K1 diacetate, vitamin K2 [20], phytyl ubiquinone and retinol) were tested for any ability to inhibit calcium ionophore, A23187, induced creatine kinase (CK) enzyme efflux. Some compounds were found to be very effective inhibitors and comparison of their structures and ability and to inhibit TBARS production in muscle homogenates revealed that the effects did not appear related to antioxidant capacity or chromanol methyl groups, but rather the length and structure of the hydrocarbon chain was the important mediator of the effects seen.     

Synthesis,cytotoxicity against human oral cancer KB cells and structure–activity relationship studies of trienone analogues of curcuminoids

A general method for the synthesis of substituted (1E,4E,6E)-1,7-diphenylhepta-1,4,6-trien-3-ones, based on the aldol condensations of substituted 4-phenylbut-3-en-2-ones and substituted 3-phenylacrylaldehydes, was achieved. The natural trienones 4 and 5 have been synthesized by this method, together with the trienone analogues 9–20. These analogues were evaluated for their cytotoxic activity against human oral cancer KB cell line. The structure–activity relationship study has indicated that the analogues with the 1,4,6-trien-3-one function are more potent than the curcuminoid-type function. Analogues with meta-oxygen function on the aromatic rings are more potent than those in the ortho- and para-positions. Free phenolic hydroxy group is more potent than the corresponding methyl ether analogues. Among the potent trienones, compounds 11, 18 and 20 were more active than the anticancer drug ellipticine. All compounds were also evaluated against the non-cancerous Vero cells and it was found that compounds 11, 12 and 17 were much less toxic than curcumin (1); they showed high selectivity indices of 35.46, 33.46 and 31.68, respectively. These analogues are regarded as the potent trienones for anti-oral cancer study.     

关节镜下同期行冻结肩松解术对肩袖损伤患者的治疗效果评估

目的:评估关节镜下同期行冻结肩松解术对肩袖损伤患者的治疗效果。方法:选择2015年3月到2018年3月在我院诊治的肩袖损伤患者70例进行研究,按随机数表法将其分为观察组(n=36)和对照组(n=34)。对照组采用传统小切口肩袖修复术治疗,观察组采用关节镜下同期行冻结肩松解术进行治疗。比较两组治疗后疗效、手术时间、术中出血量、住院时间、疼痛减轻时间、治疗前后VAS、美国肩肘外科协会评分(ASES)、Contant-Muley评分的变化情况。结果:治疗后,观察组总有效率为94.44%,显著高于对照组(73.53%,P0.05);观察组手术时间、术中出血量、住院时间及疼痛减轻时间均显著低于对照组(P0.05);两组VAS、ASES、Contant-Muley评分较治疗前均显著改善(P0.05),且观察组VAS评分明显低于对照组,ASES及Contant-Muley评分显著高于对照组(P0.05)。结论:关节镜下同期行冻结肩松解术治疗肩袖损伤的临床疗效显著优于传统小切口肩袖修复术治疗,其可显著促进关节功能恢复,并减轻患者痛苦。     

Second Generation of cycloSal‐Pronucleotides with Esterase‐Cleavable Sites: The ”Lock‐In”‐Concept

A conceptual extension of the cycloSal‐pronucleotide approach is presented. The characteristic feature of the new cycloSal‐derivatives of the anti‐HIV active nucleoside analogue d4T 1 is the incorporation of an enzymatically cleavable carboxylic ester moiety with the intention to trap the triesters inside cells (”lock‐in”‐concept). CycloSal‐triesters bearing different ester groups in the 3‐or 5‐position of the cycloSal‐moiety are described. Surprisingly, only acetyl‐and levulinyl esters are cleaved readily in CEM cell extracts while alkyl esters were found to be stable. Nevertheless, in in‐vitro anti‐HIV assays most of the compounds achieve the thymidine–kinase bypass, thus proving that they act at least as nucleotide delivery systems.     

Interactions of Potent Multisubstrate Analogue Inhibitors with Purine Nucleoside Phosphorylase from Calf Spleen—Kinetic and Spectrofluorimetric Studies

Abstract

Dissociation constants and stoichiometry of binding for interaction of trimeric calf spleen purine nucleoside phosphorylase with potent multisubstrate analogue inhibitors were studied by kinetic and spectrofluorimetric methods.     

In Search of New Inhibitors of HIV-1 Replication: Synthesis and Study of 1-(2′-Deoxy-β-D-Ribofuranosyl)-1,2,4-Triazole-3-Carboxamide as a Selective Viral Mutagenic Agent

With the emergence of HIV strains resistant or cross-resistant to nearly all antiretroviral regimen, novel therapy approaches have to be considered. As a part of our current work on viral mutagenic compounds, we prepared 1-(2′ -deoxy-β-D-ribofuranosyl)-1,2,4-triazole-3-carboxamide (2′ -deoxy-ribavirin) and its 5′ -triphosphate derivative. The nucleoside mutagenic activity was evaluated on HIV-1 NL4-3 in CEMx174 cell culture. After 2.5 months, no reduction on HIV-1 viability was observed. On the other hand, in vitro experiments with purified HIV-1 RT demonstrated that the triphosphate analog can be incorporated opposite to several natural nucleosides.