阿托品流通传感器的研制及其在流动注射分析中的应用

本文报道了一种新型的传感器——阿托品流通传感器及其在流动注射分析中的应用。采用流动注射分析法测定了硫酸阿托品片剂和注射剂、盐酸山莨菪碱注射剂、氢溴酸东莨菪碱注射剂及颠茄酊、颠茄片和复方颠茄片的含量,并对硫酸阿托品片和颠茄片含量均匀度进行了测试,方法简便、快速,样品分析速度可达每小时60～100次。     

银杏叶及其制剂的质量研究

目的：对银杏及其制剂质量的系列研究。方法：①采用酸水解－液相色谱法，测定了不同季节银杏叶内，雌雄银杏树叶内，不同土质生长的银杏树叶内，不同部位银杏树内黄桐的含量。②采用紫外对数家药厂银杏制剂片剂的含量及稳定性进行了研究。结果：①黄酮含量差异很大；②部分厂家银杏片剂的总黄酮含量低得惊人，为不合格产品。     

小叶买麻藤中买麻藤甲素的结构研究

从小叶买麻藤[Gnetum parvifolium(Warb.)C.Y.Cheng]茎的乙酸乙酯部分得到五个成分,经理化常数测定、光谱(UV,IR,MS,¹HNMR,¹³CNMR和2D-NMR)分析和衍生物制备,确定买麻藤甲素为一个新的2-苯基苯并呋喃类化合物,结构为2-(3′,5′-二羟基-4′-甲氧基苯基)-3-甲氧基5-羟基苯并呋喃。另外三个鉴定为异丹叶大黄素、白黎芦醇和β-谷甾醇.还有一个化合物正在鉴定中。     

Lipid composition and acid hydrolase content of lamellar granules of fetal rat epidermis

Lipids and acid hydrolases have been characterized in a subcellular fraction, enriched with lamellar granules (LG), derived from fetal rat epidermis. This fraction contains 23% glycosyl ceramides and ceramides, 15% free sterols, and 34% phospholipids. The lipid/protein ratio is 2.0. The sterols and sphingolipids were present in proportions similar to those previously reported in stratum corneum. These findings provide direct biochemical evidence for the widely accepted hypothesis that stratum corneum lipids are derived from exocytosis of lamellar granules into the intercellular space. The LG fraction was enriched in certain acid hydrolases including glucosidase, acid phosphatase, phospholipases A, and sphingomyelinase; other acid hydrolases, i.e., amino-glycosidases, glactosidase and aryl sulfatase (pH 5.5), and steroid sulfatase were not preferentially localized in this fraction. By modulation of phospholipids, glycolipids, and proteins in the membrane regions of stratum corneum, the acid hydrolases of LG may play a role relevant to the function and desquamation of stratum corneum.     

芳基异羟肟酸对核苷酸还原酶抑制机制的量子化学研究

应用cNDO/2量子化学方法计算了28个芳基异羟肟酸化合物的电子结构,讨论了异羟肟酸化合物抑制核苷酸还原酶的作用机制。在原络合机制(仅端基部分—CONHOH与酶中金属离子M进行单位点络合)基础上,提出了新的络合机制:当芳环上存在二相邻的—OH或—NH_2时,不仅端基部分能与金属离子M络合,且这二个相邻的—OH(NH_2)中的氧(氮)原子也可以与金属离子M络合,产生双位点络合,提高了化合物抑制核苷酸还原酶的活性。这一新的络合机制合理地解释了原络合机制所无法解释的实验事实。     

Function and Conformation of Wild-Type p53 Protein Are Influenced by Mutations in Bovine Leukemia Virus-Induced B-Cell Lymphosarcoma

The mutations of the p53 gene previously represented one of several genetic changes involved in the development of bovine leukemia virus (BLV)-induced lymphosarcoma, while the effects of these mutations on the function of p53 are unknown. We identified four mutations of p53 gene in BLV-infected cattle with lymphosarcoma and demonstrated clearly the existence of two functionally distinct groups of mutants: (i) the mutant forms with substitutions at codons 241 and 242, which were mapped within an evolutionally conserved region and corresponded to the human "hot-spot" mutations, had completely lost the capacities for transactivation and growth suppression and gained transdominant repression activity in p53-null SAOS-2 cells; and (ii) the mutations at codons 206 and 207 were located outside the evolutionally conserved regions. These mutants partially retained the capacity for transactivation and growth suppression and failed to inhibit the transactivation activity of coexpressed wild-type p53, instead showing an enhancement of this activity. In addition, protein analysis using an antibody specific for the mutant form revealed that the mutations at codons 206 and 242 induced a "mutant" conformation of the bovine p53 proteins. Collectively, these results show that mutations of p53 gene in BLV-infected cattle with lymphosarcoma can potentially alter its physiological function and may play an important role in BLV-induced leukemogenesis. Copyright 1998 Academic Press.     

Sex difference in rabbit eyelid conditioning

The rabbit eyelid conditioned reflex has been used to compare associative learning in males and ovariectomized females. A new method for monitoring eyelid movements is described. Rabbits were trained on simple delay classical conditioning. Conditioned responses were recorded during 8 acquisition days and 6 days of extinction training. Analysis of variance (ANOVA) and the least significant difference (LSD) post hoc test was used to analyze the data. The results showed that males achieved significantly better learning than females during the first day of acquisition but later they slowly attained the best result, contrary to females. Moreover, extinction of the conditioned reflex was significantly faster in females than in males. It is postulated that females learn and extinguish faster than males because of a higher level of brain plasticity.