The prokaryotic antecedents of the ubiquitin-signaling system and the early evolution of ubiquitin-like β-grasp domains

Background  

Ubiquitin (Ub)-mediated signaling is one of the hallmarks of all eukaryotes. Prokaryotic homologs of Ub (ThiS and MoaD) and E1 ligases have been studied in relation to sulfur incorporation reactions in thiamine and molybdenum/tungsten cofactor biosynthesis. However, there is no evidence for entire protein modification systems with Ub-like proteins and deconjugation by deubiquitinating enzymes in prokaryotes. Hence, the evolutionary assembly of the eukaryotic Ub-signaling apparatus remains unclear.     

福建冬青属二新种

本文描述了发现于福建的冬青科冬青属2新种——泰宁冬青Ilex tainingensis G. S. He和南平冬青I. nanpingensis G. S. He，并分别说明两者与其他近缘种的区别要点。泰宁冬青与太平山冬青I. sugerokii Maxim.的区别在于前种小枝被毛，无棱槽，叶片宽卵圆形，花淡紫色，分核表面具细条纹，背后中部有一凹槽。南平冬青与拟榕叶冬青I. subficoidea S. Y. Hu区别在于前种果为椭圆形，较大，表面光滑无腺点，果梗长于1 cm，每分核上端有2尖角，均可以区别。     

白纹伊蚊幼虫龄期的发育历期

在实验室内20±1℃, 23±1℃, 25±1℃, 28±1℃和30±1℃恒温条件下, 观察了白纹伊蚊(Aedes albopictus)幼虫(广州株)的发育历期.幼虫的总发育历期和各龄幼虫的发育历期随温度的上升而缩短, 各龄幼虫历期在总发育历期中占有恒定的百分比, 据此计算出其捕获机率.各龄幼虫的发育历期与温度呈直线回归关系.通过积温公式, 求出各龄幼虫的积温常数.此外还探索了营养对幼虫发育历期的影响, 从而影响各龄幼虫捕获机率的计算.     

内毒素对人血小板聚集,释放的体外作用

大肠杆菌 O55B5内毒素在体外可抑制人血小板自发性聚集,并使血小板内 cAMP、钙调素明显增高,但对肾上腺素诱发的血小板聚集无作用,也不能引起血小板致密颗粒和α-颗粒的释放。此外还观察到内毒素组无血小板上清液中5-HT 含量减少。     

Bleeding time in patients with hepatic cirrhosis.

OBJECTIVE--To determine the frequency of an abnormal bleeding time in patients with cirrhosis and to relate this to known factors that affect primary haemostasis and to the severity of liver disease. DESIGN--Prospective clinical and laboratory study in patients admitted for complications or investigations of liver disease. SETTING--Royal Free Hospital hepatobiliary and liver transplantation unit. SUBJECTS--100 Consecutive inpatients aged 17-74 with various forms of cirrhosis, including alcoholic, biliary, autoimmune, viral, and cryptogenic. At least 10 days had elapsed since any episodes of bleeding, resolution of sepsis, or alcohol intake. No patient was taking any drug known to affect primary haemostasis. MAIN OUTCOME MEASURES--Bleeding time as measured with the Simplate double blade template device. A bleeding time longer than 10 minutes was considered abnormal. Other measures were platelet count, prothrombin time, partial thromboplastin time, packed cell volume, and blood urea, serum bilirubin, and serum albumin concentrations, all measured on each subject at the same time by standard laboratory methods. RESULTS--A weak but significant correlation existed between the bleeding time and the platelet count (rs = 0.483; p less than 0.001). There were significantly lower platelet counts, longer prothrombin times, and higher blood urea and serum bilirubin concentrations in the 42 patients with bleeding times of 10 minutes or more compared with the 58 patients with bleeding times less than 10 minutes. Multiple linear regression analysis showed that the bilirubin concentration as well as the platelet count was independently correlated with the bleeding time. The combination of a platelet count greater than 80 x 10(9)/l and a prothrombin time less than 17 seconds (usually taken as safe limits for performing routine liver biopsy) did not predict a normal bleeding time. Ten of 39 patients fulfilling these criteria had a prolonged bleeding time. CONCLUSIONS--Prolonged bleeding time is common in patients with cirrhosis, even in those with prothrombin times and platelet counts within "safe limits" for invasive procedures. The severity of liver disease as assessed by the bilirubin concentration plays an important part in determining the bleeding time in cirrhosis. The bleeding time should be measured when assessing patients for invasive procedures who have a raised bilirubin concentration or poor hepatic function, even if the platelet count and prothrombin time are considered adequate.     

Immobilization of wild dogs (Lycaon pictus) with a tiletamine hydrochloride/zolazepam hydrochloride combination and subsequent evaluation of selected blood chemistry parameters

A tiletamine hydrochloride/zolazepam hydrochloride combination was used successfully to immobilize captive untamed wild dogs (Lycaon pictus) (n = 16) at dosage rates ranging from 2.3 to 32.3 mg/kg. Animals remained immobilized for periods ranging from 35 min to 24 hr 14 min. There was a significant positive correlation (r = 0.85, P less than 0.01) between dosage rate and the time immobilized. Profuse salivation and intermittent mild myoclonal contractions were observed in some wild dogs. Mildly reduced partial oxygen and carbon dioxide pressures as well as reduced concentrations of bicarbonate were observed in arterial blood at 10 and 20 min after administration of the drug. Serum concentrations of sodium, potassium, chloride, phosphorus, calcium, magnesium, urea, creatinine, glucose, proteins, albumin, gammaglutamyltransferase, creatinine kinase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase, insulin, cortisol and thyroxine are presented. These concentrations were found to be in agreement with values previously reported for wild dogs.     

云南鲤科鱼类一新属新种(鲤形目:鲤科:(鱼丹)亚科)

本文记述采自云南澜沧江水系的鲤科(鱼丹)亚科鱼类一新属新种。新属裸(鱼丹)属Gymnodanio gen.nov.在侧线、臀鳍条数目等特征上近似于低线(?)属Barilius,但以其除侧线鳞外体裸露无鳞,具不完全之腹棱等而与其及(鱼丹)亚科现有各属相区别。新种命名为条纹裸(鱼丹)G.strigatus sp.nov.。     

日本血吸虫尾蚴的组织化学及扫描电镜观察

日本血吸虫尾蚴具有一个头腺、2对前钻腺及3对后钻腺,其解剖学位置、构造、化学成分及功能均有区别。钻腺分泌物含有多糖酶及蛋白酶。尾蚴的前端系特化的头器结构,它具有半月形嵴、钻腺开口及乳突。     

福尔马林致痛提高大鼠中枢μ阿片受体密度及电针的加强作用

用放射自显影方法观察到;（１）大鼠脚掌注射福尔马林后,某些与镇痛有关的脑区如尾核头部、伏隔核、杏仁核、中央灰质、脚间核、中缝大核、脊髓背角等结构中μ阿片受体密度明显增加（Ｐ＜０．０５,Ｐ＜０．０１）;（２）给予电针抑制痛反应的大鼠,在其大部分上述结构及扣带回、隔区、视前内侧区、内膝体、上丘、中缝背核及中央上核受体密度明显增加;与福尔马林注射组相比,脚间核、中央灰质尾端腹外侧区、腰膨大背角的受体密度进一步增加。从而在受体水平支持伤害性刺激可以激活体内内阿片肽能活动,而电针可以加强这一活动的设想。