蛋白质三级结构预测方法简述

随着各种生物全基因组测序工作的不断深入，越来越多的核酸序列清晰的呈现在世人面前。与此同时，我们明确知道空间结构的蛋白质数目却增长缓慢，而且两者之间增长速度的差异正在进一步扩大。因为蛋白质的生物学功能在很大程度上取决于其空间结构，所以弄清楚蛋白质的结构进而理解其结构与功能的关系具有重要意义。但通过实验方法获得蛋白质结构不仅成本高而且速度慢，     

三种生物制剂防治人参立枯病的初步研究

立枯病(Rhizoctonia solani)系人参苗期主要病害,发病率一般在8%-32%,严重者可达40%。     

奶牛发情周期中毛 唾液和乳汁孕酮水平的变化

本实验采用放射免疫分析法(RIA)测定了11头奶牛一个发情周期里毛、唾液、乳汁中孕酮(P_4)含量。经产牛(n=8)的毛和唾液中P_4水平变化与乳汁中P_4水平变化一致。青年牛(n=3)的毛和睡液中的P_4水平变化一致,并分别与经产牛毛和唾液中P_4水平变化一致。7头配种后的经产牛和5头配种后的青年牛分别取20和23天的样品进行妊娠诊断,与配种后60天的直检结果相对照,依据经产牛毛、乳P_4水平进行妊娠诊断的阳性准确率分别是85.7％(6/7)和100％(7/7),依据青年牛毛P_4水平进行妊娠诊断的阳性准确率为100％(5/5)。     

THE USE OF IMIDOCARB DIPROPRIONATE FOR THE TREATMENT OF THEILERIA SERGENTI INFECTIONS OF CATTLE

SUMMARY Imidocarb diproprionate (IMDP) was used therapeutically at a dose of 1.2 mg IMDP/kg of body weight against Theileria sergenti infections in Hereford heifers on the island of Jeju-Do, Republic of Korea. In the first experiment IMDP was seen to be at least as effective in reducing T. sergenti parasitaemias as primaquine phosphate (primaquine), the drug normally used on the island. In the second and third experiments IMDP was shown to reduce T. sergenti parasitaemias by about 80%. No drug is known to be completely effective against T. sergenti infections but the suggestion is made that IMDP may be used in preference to primaquine for treatment of acutely ill animals since it also has the advantage of eliminating Babesia ovata, another element of the piroplasmosis syndrome on the island.     

香石竹叶斑病防治研究

本文报道作者等于1978～1980年间对香石竹叶斑病的防治研究结果。此病主要为害叶片造成叶斑和叶枯,但也可造成茎腐和花枯。根据本病原分生孢子色泽较深、喙较短、纵向斜向分隔较多等特点,确认上海地区香石竹叶斑病病原为Alternaria dianthi Stev.et Hall而非Alternaria dianthicola Neerganrd。对其形态大小进行了描述。土中病残体是此病的初次侵染源。越冬后的分生孢子是此病的初侵染源菌态之一。霉季和台风季多雨.露地栽培、种植感病品系均有利于发病。栽培措施可以减轻发病程度。试验证明防病有效的药剂有:土壤消毒可以0.1％五氯硝基苯拌土;插条浸药:10％401的1000倍液浸半小时或0.1％高锰酸钾液浸10分钟;生长季节喷雾:0.5％的波尔多液或75％的代森锰锌500倍液,10天1次,在每次摘芽作业后及时喷施。     

Antitumor principle constituents of Myrica rubra Var. acuminata

Myrica rubra var. acuminata is a native shrub widely distributed and used as folk medicine in Taiwan for stomach disorders and diarrhea. Column chromatography combined with cytotoxic bioassay-guided fractionation was performed to isolate the antitumor principles from fresh leaves of M. rubravar. acuminata. The 20% MeOH eluate fraction of M. rubra var. acuminata inhibited the viability of HeLa and P-388 cells in an in vitro assay and an in vivo P-388 tumor-bearing CDF(1) mouse model. The percent increase in life span (%ILS) of 20% MeOH eluate fraction was greater than 125%. (-)-Epigallocatechin 3-O-gallate (1) and prodelphinidin A-2,3'-O-gallate (2) were isolated from D-20 as the antitumor principle components. Both compounds can inhibit the growth of HeLa cells, but 1 had lower cytotoxic effects in normal cervical fibroblasts than did 2. Moreover, pretreatment with a caspase-3 specific inhibitor prevented 1- and 2-induced poly(ADP-ribose) polymerase cleavage. In view of these results, we suggest that 1 and 2 can induce apoptosis in HeLa cells and that activation of caspase-3 may provide a mechanistic explanation for their cytotoxic effects. Therefore, we suggest that the 20% MeOH eluate fraction extract is good for health and that M. rubra var. acuminata is an economically valuable plant.     

Flow cytometric assessment of ethylene glycol monoethyl ether on spermatogenesis in rats

The effects of ethylene glycol monoethyl ether (EGEE) on testicular cell populations in rats were investigated by a flow cytometric method. Rats were administered by gavage with EGEE at the various doses of 0 (saline alone), 100, 200, 400, and 800 mg/kg body weight/day for 4 weeks. The treatment of EGEE caused decreases in the weight of testis and epididymis and in the number of testicular cells. Histopathologically, exfoliation of germ cells into the tubular lumen was observed at the doses of above 200 mg/kg. The treatment of EGEE at the dose of 400 mg/kg caused moderate testicular degeneration. A significant depletion of haploid cells and a disproportionate ratio of diploid and tetraploid cells were observed as determined by flow cytometric analysis. These results indicate that the toxic effect of EGEE on the male reproductive system may be strongly associated with the disproportion of testicular germ cells.     

Effect of intravenous mannitol upon the resistive index in complete unilateral renal obstruction in dogs

Some studies have shown that relative to baseline, the renal resistive index (RI) remains unchanged in nonobstructed kidneys and increases in obstructed kidneys after administration of furosemide. To our knowledge, the effect of mannitol administration on the renal RI of dogs has not been reported. We evaluated the renal RI in 16 kidneys in 8 young adult dogs after administration of mannitol. The mean RI decreased significantly from baseline (P < .01). Additionally, left complete ureteral obstruction wasinduced in 5 dogs. Evaluation by Doppler ultrasonography was performed for 5 days. On the 5th day, Doppler examination was repeated at 30 and 60 minutes after administration of mannitol to obstructed dogs. After induction of left ureteral obstruction, the RI of the left kidney increased significantly over 5 consecutive days. Administration of mannitol decreased the RI in the nonobstructed contralateral kidneys, and thus the RI difference between obstructed and nonobstructed kidneys was increased above normal (P < .001). In conclusion, administration of mannitol may be useful as another diuretic agent to identify unilateral ureteral obstruction on Doppler sonographic examination.