The isolation of pure cholinergic nerve terminal sacs (T-sacs) from the electric organ of juvenile Torpedo.

The problem of synaptosome formation in the electric organ of Torpedo has been re-investigated using tissue from juvenile fish. This tissue is softer than adult material and can be easily homogenized in an Aldridge-type homogenizer. Homogenates so prepared contain a significant number of synaptosome-like structures which can be purified by differential and density gradient centrifugation. The purified particles are enriched in acetylcholine and choline acetyltransferase; they also contain lactate dehydrogenase activity, most of which is in an occluded form. The structure of these particles as revealed by electron microscopy is unusual in that they have no post-synaptic adhesions, relatively few synaptic vesicles and no intraterminal mitochondria. Because of their unusual morphology we have named these particles nerve terminal sacs (T-sacs). A high-affinity, hemicholinium-3 sensitive choline uptake system with an apparent K_m of 1–3 μm is associated with the T-sacs.     

Mucosal bromodomain-containing protein 4 mediates aeroallergen-induced inflammation and remodeling

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Comparison of synaptic plasma membrane and synaptic vesicle polypeptides by two-dimensional polyacrylamide gel electrophoresis.

Extracts of chick brain synaptic plasma membranes, synaptic vesicles, and mixtures of membranes and vesicles were examined by electrophoresis on two-dimensional polyacrylamide gels by a modification of the O'Farrell technique. Synaptic plasma membranes had twenty-one major polypeptides; synaptic vesicles had seventeen. Thirteen major polypeptides were common to both fractions. The similarities between the synaptic vesicle and synaptic plasma membrane patterns are unlikely to be due to contamination of one fraction by the other or to contamination of both fractions by microsomes, synaptoplasm or mitochondria. Our findings are consistent with mixing of membrane proteins occurring during exocytosis but it remains to be shown that these synaptic subfractions are not contaminated by a type of membrane for which markers are not yet available.     

Localization of the disulfide bridges of human histocompatibility antigens.

Both papain-solubilized and detergent-solubilized human histocompatibility antigens have been treated with NTCB (2-nitro-5-thiocyanatobenzoic acid) which cleaves these molecules at cysteine residues. A study of the fragment produced has made it possible to deduce the size and location of the two disulfide loops in these molecules. The sizes of the two loops in HLA-B7 and in the mixture HLA-B7 + 12 are about 5100 and 6600 daltons, a size similar to that of the disulfide loops found in immunoglobulins. The disulfide loops in HLA-A2 may be smaller in size. The two loops are located in middle regions of these molecules; neither the N-terminal nor the C-terminal regions contain disulfide loops.     

乙亚胺致急性白血病1例

乙亚胺作为一种抗代谢药 ,临床上常用于银屑病的治疗。但在治疗过程中我们发现 1例病人引起急性粒 单核细胞白血病 ,作者未见国内文献报道 ,现报告如下。病人 ,男性 ,46ａ,已婚 ,农民。因发热、乏力、进行性皮肤苍白 0 .5ｍｏ入院。该病人既往体健 ,2ａ前因患银屑病自服乙亚胺片 (ｅｔｈｙｌｅｎｅｄｉａｍｉｎｅｔｅｔｒａａｃｅｔｙｌｉｍｉｄｅ ,南京第二制药厂产 ,批号 2 0 0 0 0 3 0 3及 2 0 0 0 0 5 0 1,规格 :每片 10 0ｍｇ)每日3 0 0～ 60 0ｍｇ ,其中 ,连续服药每日 60 0ｍｇ时间达 2ｍｏ。用药后银屑病基本治愈 ,以后间断用药维…     

利用LC-MS/MS法快速鉴定盐酸头孢吡肟中的同分异构体杂质

目的建立应用LC-MS/MS技术快速鉴定盐酸头孢吡肟原料药中的同分异构体杂质的方法。方法以乙腈-10 mmol·L^-1乙酸铵(5∶95)为流动相经C₁₈柱分离,通过电喷雾串联质谱在线检测，获得相关的色谱和质谱信息。结果在所建立的条件下，盐酸头孢吡肟及其同分异构体杂质获得有效分离，主成分和其同分异构体杂质的保留时间分别为15.28 min和9.18 min，同时它们的二级质谱产物离子信息及其裂解方式呈现明显的差异。结论本法能快速、准确地分离鉴定盐酸头孢吡肟原料药中的同分异构体杂质，从而可以对其原料药进行质量控制。     

Antioxidant properties of ursodeoxycholic acid

We have investigated potential antioxidant properties of the clinically relevant bile acid UDCA, which reaches therapeutic concentrations up to 0.09 and 29 mM, respectively, in human plasma and bile. UDCA was an excellent scavenger of OHz.rad; generated by FeCl(3)-EDTA, H(2)O(2) and ascorbate in the deoxyribose oxidation test, showing IC(min) and IC(50) values of 0.02 and 0.2 mM, respectively, and a second-order rate constant for reaction with OHz.rad; of 2+/-0.1 x 10(10)M(-1)s(-1). Notably, the drug could enhance at 1.5 mM concentration the antioxidant capacity of human bile against OHz.rad;-induced deoxyribose oxidation. UDCA also showed antioxidant effects in the deoxyribose test performed with nonchelated iron ions, such as Fe(2+) plus H(2)O(2) (IC(min): 7 mM, IC(50): 20 mM) or Fe(3+) plus H(2)O(2) and ascorbate (IC(min): 0.3 mM, IC(50): 5 mM), and inhibited ferrozine-Fe(2+) and desferrioxamine-Fe(3+) complexes formation with IC(50) values of, respectively, 12 and 0.3 mM, indicating that the drug interacts more with iron(III) than with iron(II). Moreover, UDCA significantly inhibited phospholipid liposome peroxidation induced by the OHz.rad;-generating system FeCl(3)-EDTA, H(2)O(2) and ascorbate (IC(min): 0.75 mM, IC(50): 3 mM), and by peroxyl radicals generated in the aqueous phase by AAPH (IC(min): 8 mM, IC(50): 14 mM). UDCA, even at 25 mM concentration, was ineffective on the lipoperoxidation mediated by Fe(2+) alone, but at the same concentration counteracted significantly that by Fe(3+) plus ascorbate, further pointing to its preferential antioxidant interaction with iron(III).In conclusion, UDCA has direct antioxidant properties, which are especially relevant against Fe(3+)- and OHz.rad;-dependent biomolecular oxidative damage; such properties are evident at therapeutically relevant drug concentrations, suggesting that UDCA could act as an antioxidant in vivo.     

盐酸诺拉曲塞的合成

2-溴-4-硝基甲苯经催化氢化、与水合氯醛和盐酸羟胺反应、环合制得4-溴-5-甲基靛红,再经Baeyer-Villiger反应、甲酯化、与盐酸氯甲脒环合、Ullmann反应、成盐结晶制得胸苷酸合成酶抑制剂盐酸诺拉曲塞二水合物,总收率为8%。