新型麻醉药异丙酚的氧化动力学

采用高效液相色谱法测定了异丙酚在不同温度下及其甲醇 水（Ｖ∶Ｖ＝７０∶３０）混合溶液在不同ｐＨ值下的反应速率常数，并求出了异丙酚氧化反应的活化能，结果表明ｐＨ值与温度对异丙酚的氧化动力学均有影响     

Activity of (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC) against guinea pig cytomegalovirus infection in cultured cells and in guinea pigs

(S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine, HPMPC, and two HPMPC-related nucleoside analogs, (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine, HPMPA, and (2-phosphonylmethoxyethyl)guanine, PMEG, were evaluated for their antiviral activities against guinea pig cytomegalovirus (GPCMV) infection in guinea pig embryo (GPE) cells and human cytomegalovirus (HCMV) infection in human diploid fibroblast (MRC-5) cells. DHPG, 9-(1,3-dihydroxy-2-propoxymethyl)guanine, was used for comparison. The antiviral activity of HPMPC against GPCMV infection in vivo and its toxicity to Hartley guinea pigs were also evaluated. The 50% antiviral effective doses (ED50) of HPMPC, HPMPA, PMEG and DHPG against GPCMV infection in GPE cells were 0.22, 1.4, 0.07 and 62 microM, respectively; and against HCMV infection in MRC-5 cells, the ED50s were 0.51, 0.72, 0.01 and 17.5 microM, respectively. Their cytotoxic doses (CyD50) in GPE replicating cells were 84, 35, 1.4 and 700 microM, respectively and in MRC-5 cells were approximately 114, 31, 0.86 and 750 microM, respectively. Based on their calculated therapeutic indexes, HPMPC was the most potent and selective of the four compounds tested. In vivo, during acute infection, the spleen indexes of all infected animals that were treated with 1.25 to 5.0 mg/kg/day of HPMPC for 5 days were significantly reduced as compared with sham-treated animals. Virus infectivity titers in blood and various tissues of infected animals treated with HPMPC, 2.5 or 1.25 mg/kg/day were not significantly lower than those of the infected, sham-treated animals; with 5 mg/kg/day, infectivity titers in the blood, spleen, and salivary gland were significantly lower in HPMPC-treated than in sham-treated animals. However, HPMPC was toxic to guinea pigs especially at doses of 5 to 10 mg/kg/day. These data showed that HPMPC was highly active and selective in cultured guinea pig cells and human fibroblast cells against CMV infection but did not effectively inhibit GPCMV infection in guinea pigs at minimum toxic concentrations.     

裂叶苣荬菜的化学成分研究

从菊科裂叶苣荬菜的干燥全草中分得2个黄酮化合物,经理化常数测定及光谱分析鉴定为洋芹素和木犀草素-7-O-葡萄糖甙。     

液膜法提取硝酸水溶液中Ag~+的工艺过程

液膜的组成为:2%石油硫醚-4%多丁二酰亚胺-94%煤油,内相试剂为:1～2mol/L的氨水溶液。较为适宜的操作条件为:乳水比为1:3;内油比为0.8:1;外相硝酸浓度为0.5～1mol/L;常温操作。当料液中的银离子浓度小于800ppm时,一次提取率可达97%以上。本工艺具有分离速度快,效率高、选择性好等优点。     

Visualization of patent foramen ovale by biplanar transesophageal echocardiography

Summary It is difficult for conventional transthoracic echocardiography (TTE), by which precise and accurate images of interatrial septum (IAS) can not be acquired, to diagnose patent foramen ovale (PFO) clearly. To evaluate the diagnostic value of biplanar transesophageal echocardiography (TEE) for PFO, TTE and biplanar TEE were performed simultaneously in 270 patients. It was found that in 7 patients patent foramen ovale was detected only through longitudinal planes of biplanar TEE. IAS, which consists of primitive septum and membrane of fossa ovalis, can be directly visualized by two-dimensional images of TEE; in patients with PFO, a dull color flow, which shunts from the right atria to the left atria through the gap between primitive septum and fossa ovalis, can be detected by color Doppler flow images. Furthermore, some right-to-left shunting microbubbles through the valve of patent fossa ovalis can be discovered by cardiac acoustic contrast echocardiography. In conclusion, biplanar TEE combined with color Doppler image and cardiac acoustic contrast facilitates a definite diagnosis of patent foramen ovale as the excellent anatomic images of IAS can be obtained from multiple views under this kind of performance.     

线性变温法研究硫酸链霉素粉针剂的稳定性

用线性变温法对硫酸链霉素粉针的稳定性进行了测定,得出25℃时的降解反应速度常数 k_(25)为1.744×10~(-6)h~(-1)、化学反应的表观活化能为107.9kJ/mol,25℃时贮存的 t_(0.9)为6.9年。     

某部队急性腹泻病监测报告 Ⅰ.流行病学部分

１９９１年６月～１９９２年５月在驻粤某部队进行了急性腹泻病的主动监测。年发病率为０．６４～１．０次／人／年。发病率与相对湿度（Ｘ２）、气温（Ｘ３），特别是雨量（Ｘ１）的关系经多元回归分析表明呈正相关。ｙ＝１．９８＋０．０２ｘ１＋０．０２ｘ２＋０．０７ｘ３，ｒ＝０．８７２７，Ｐ＜０．０１。病例－对照研究结果提示，饭前、便后不洗手等生活习惯用腹泻发病有密切关系。２６．３％的患者有淋雨、腹部受凉或感冒等     

Chemical Pathways of Peptide Degradation. V. Ascorbic Acid Promotes Rather than Inhibits the Oxidation of Methionine to Methionine Sulfoxide in Small Model Peptides

The effect of primary structure and external conditions on the oxidation of methionine to methionine sulfoxide by the ascorbate/Fe³⁺ system was studied in small model peptides. Degradation kinetics and yield of sulfoxide formation were dependent on the concentration of ascorbate and H⁺, with a maximum rate observed at pH 6–7. Phosphate buffer significantly accelerated the peptide degradation compared to Tris, HEPES, and MOPS buffers; however, the formation of sulfoxide was low. The oxidation could not be inhibited by the addition of EDTA. Other side products besides sulfoxide were observed, indicating the existence of various other pathways. The influence of methionine location at the C terminus, at the N terminus, and in the middle of the sequence was investigated. The presence of histidine in the sequence markedly increased the degradation rate as well as the sulfoxide production. The histidine catalysis of methionine oxidation occurred intramolecularly with a maximum enhancement of the oxidation rate and sulfoxide production when one residue was placed between the histidine and the methionine residue.     

豆渣纤维的降脂作用及对血液流变学影响的研究

以ＳＤ大鼠为对象，研究了豆渣纤维对高胆固醇膳动物脂质代谢和血流变性的影响，并与果胶和纯纤维素进行比较，结果表明：８周实验后，豆渣与果胶组动物的血清总胆固醇（ＴＣ）和低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）显著降低，但豆渣组的血脂水平比果胶组更低（Ｐ＜０．０５）。而纯纤维素组未显出降脂作用。各组大鼠的甘油三醋（ＴＧ）和高密度脂蛋白胆固醇（ＨＤＬ－Ｃ）也无明显变化。实验同时表明，６％的豆渣纤维与果胶均可使高脂大鼠的血粘度及血小板聚集率降低（Ｐ＜０．０５），且前者优于后者。相关分析显示，血脂与血流变学指标间存在显著相关性（Ｐ＜０．０５），其中ＴＣ与ＬＤＬ－Ｃ是影响血流变性的重要因素。６％的以上各种纤维摄入量均不影响大鼠的摄食量与生长。