铁叶绿酸钠对小鼠行为发育毒性的实验研究

铁叶绿酸钠为叶绿素衍生物,研究表明铁叶绿酸钠治疗妊娠期缺铁性贫血,疗效显著。由于妊娠期用药可能对子代产生行为发育毒性,因此本文重点针对铁叶绿酸钠在动物围产期用药后,可能对子代动物的神经行为发育产生的毒性进行了测试,试验结果表明在高、中、低三种剂量下其对子代小鼠无明显行为发育毒性。     

水杨酸盐及相关化合物对细菌的作用

水杨酸盐类制剂及其相关化合物对不同细菌的作用是多样的。首先,水杨酸盐类制剂抑制很多细菌如大肠杆菌、铜绿假单胞菌、幽门螺杆菌及表皮葡萄球菌等的生长,并影响细菌的菌毛、鞭毛、生物被膜及尿素酶等毒力因子的生成及活性,从而改变其致病性。此外,水杨酸盐类制剂改变细菌对抗菌药的敏感性:一方面,生长在水畅酸盐类制剂中的大肠杆菌、鼠伤寒沙门杆菌、金黄色葡萄球菌等可产生多重抗菌药耐药,但对于氨基糖苷类抗菌药,水杨酸盐类制剂却使细菌对其敏感性提高;另一方面,幽门螺杆菌及白色念珠菌等在水杨酸盐类制剂的作用下,对抗菌药的敏感性提高。     

头孢硫脒对老年人呼吸道革兰阳性细菌感染疗效观察

目的探讨头孢硫脒对老年人呼吸道革兰阳性细菌感染的临床疗效及安全性.方法选择住院呼吸道革兰阳性细菌感染并且年龄≥60岁的老年患者共56例,用头孢硫脒进行治疗,4 g·d,分2次给药,静脉滴注,疗程5～16(9.4±3.1) d,不同时使用其他抗生素.结果总有效率及治疗后细菌阴转率均达到86%,除1例患者出现皮肤瘙痒外,未发现其他不良反应,亦无肝、肾功能方面的损害.结论头孢硫脒用于治疗老年人呼吸道革兰阳性细菌感染安全、有效.     

铁叶绿酸钠改善记忆作用的研究

目的观察铁叶绿酸钠改善大鼠记忆作用及对大鼠脑血氧的影响.方法用铁叶绿酸钠25,50,100 mg·kg-1分别给大鼠连续灌胃给药,进行迷宫试验,对东茛菪碱损伤记忆拮抗作用试验及其对脑血氧的影响试验.结果铁叶绿酸钠可以减少大鼠达标前所需的反应次数、提高大鼠主动回避反应率、缓解东茛菪碱所致的学习障碍;增加大鼠血氧分压、提高大鼠血氧浓度和血氧饱和度.结论铁叶绿酸钠具有改善记忆的作用.     

Effects of phospholipases C from bacteria on binding of enkephalin to rat brain membranes

The effects of phospholipases C on the equilibrium constants and maximal binding capacities of tritiated [D-Ala2,-D-Leu5] enkephalin to rat brain membranes were investigated using phosphatidylcholine-hydrolyzing phospholipase C and sphingomyelinase C of Bacillus cereus and, phosphatidylinositol-specific phospholipase C of Bacillus thuringiensis. When 72% of the phosphatidylinositol in the rat brain membranes was hydrolyzed by phosphatidylinositol-specific phospholipase C, the affinity of opiate receptor for [D-Ala2,-D-Leu5] enkephalin was almost doubled and maximal binding of [D-Ala2,-D-Leu5] enkephalin was decreased to 87% of control. Although specific [D-Ala2,-D-Leu5] enkephalin binding was decreased with phosphatidylinositol hydrolysis when measured at higher concentration (30 nM) of [D-Ala2,-D-Leu5] enkephalin, the specific binding was increased with the hydrolysis of phosphatidylinositol when measured at lower concentration (6 nM) of the ligand. On treatment of membranes with phosphatidylcholine-hydrolyzing phospholipase C, specific [D-Ala2,-D-Leu5] enkephalin binding was drastically decreased with the progressive hydrolysis of phosphatidylcholine in the rat brain membranes, and specific binding was completely lost after 81% hydrolysis of phosphatidylcholine. However, the affinity of opiate receptor for [D-Ala2,-D-Leu5] enkephalin was not influenced, and maximal binding was decreased to 32% of the control when 61% of phosphatidylcholine was hydrolyzed. Treatment with sphingomyelinase C did not cause any appreciable reduction of specific [D-Ala2,-D-Leu5] enkephalin binding. From these results, it is concluded that the binding of [D-Ala2,-D-Leu5] enkephalin to opiate receptor is influenced by changes in the phospholipid environment of the rat brain membranes, and that phosphatidylinositol may be a modulator for the function of the receptor.     

Effect of aspoxicillin on anaerobic bacteria

Aspoxicillin (ASPC), a semisynthetic penicillin has a broad spectrum of antibacterial activities against Gram-positive and Gram-negative anaerobic bacteria. Its in vitro antibacterial activity was less than those of cefoxitin against Peptostreptococcus and Veillonella, but was significantly high against Bacteroides fragilis, one of the most clinically important anaerobe. The therapeutic and/or protective effect of ASPC in experimental subcutaneous abscess or experimental intraabdominal mixed infection due to beta-lactamase producing B. fragilis and non-producing Escherichia coli were much stronger than those of ticarcillin. In order to account the superiority of ASPC in vivo, the effects of ASPC and other beta-lactams on B. fragilis were compared and the results were analyzed in relation to their in vitro bactericidal activities, stability against the beta-lactamase, binding properties with penicillin-binding proteins and pharmacokinetic properties. Interestingly, administration of ASPC did not increase the bacterial counts of Clostridium difficile in caecal contents, but piperacillin, ticalcillin, carbenicillin, ampicillin and cefotaxime increased the counts.     

叶绿素衍生物的生物活性研究进展

叶绿素衍生物是近年发展起来一类很有理论研究与药用价值的化合物。本文对叶绿素衍生物生物活性的研究进展情况作一综述,讨论了叶绿素衍生物对肿瘤、肝脏损伤、贫血等疾病的作用。     

浮游植物叶绿素a4种提取方法的比较

目的优选地表水中浮游植物叶绿素a的提取方法。方法实验室制备发生水华的水样,分别选用丙酮研磨法、冻融法、丙酮加热法、混合溶剂法4种方法提取叶绿素a,进行叶绿素a含量的测定。结果冻融法、丙酮加热法、混合溶剂法对样品中叶绿素a的提取效果及方法精密度优于丙酮研磨法（P〈0.05）,差异有统计学意义;丙酮加热法和混和溶剂法耗时较短,叶绿素a在丙酮和混合溶剂中稳定性差异无统计学意（P〉0.05）。结论丙酮加热法和混和溶剂法可为常用叶绿素a测量方法,尤其适用于大批量水环境样品的测定。     

Effects of living cyanobacteria, cyanobacterial extracts and pure microcystins on growth and ultrastructure of microalgae and bacteria.

In this study, we demonstrate the inhibitory effect of both cyanobacterial extracts and pure microcystins on the growth of microalgae and bacteria. This inhibitory effect was more persistent in pure microcystins than in the extracts, which lost their properties eight days after exposure. In addition, the effects on bacteria were longerlasting than those on microalgae. The microalgae exposed to both extracts and cultures of microcystin producing species showed morphological and ultrastructural alterations, even in cases where there was no clear effect on growth. The implications for colonisation and benthic communities structure and development are discussed in the context of biomonitoring.