Carboxylesterase catalyzed 18O-labeling of carboxylic acid and its potential application in LC-MS/MS based quantification of drug metabolites

LC-MS quantification of drug metabolites is sometimes impeded by the availability of internal standards that often requires customized synthesis and/or extensive purification. Although isotopically labeled internal standards are considered ideal for LC-MS/MS based quantification, de novo synthesis using costly isotope-enriched starting materials makes it impractical for early stage of drug discovery. Therefore, quick access to these isotope-enriched compounds without chemical derivatization and purification will greatly facilitate LC-MS/MS based quantification. Herein, we report a novel ¹⁸O-labeling technique using metabolizing enzyme carboxylesterase (CES) and its potential application in metabolites quantification study. Substrates of CES typically undergo a two-step oxygen exchange with H₂¹⁸O in the presence of the enzyme, generating singly- and doubly-¹⁸O-labeled carboxylic acids; however, unexpected hydrolytic behavior was observed for three of the test compounds – indomethacin, piperacillin and clopidogrel. These unusual observations led to the discovery of several novel hydrolytic mechanisms. Finally, when used as internal standard for LC-MS/MS based quantification, these in situ labeled compounds generated accurate quantitation comparable to the conventional standard curve method. The preliminary results suggest that this method has potential to eliminate laborious chemical synthesis of isotope-labeled internal standards for carboxylic acid-containing compounds, and can be developed to facilitate quantitative analysis in early-stage drug discovery.     

Wound conditioning by vacuum assisted closure (V.A.C.) in postoperative infections after dorsal spine surgery

The use of vacuum assisted closure (V.A.C.) therapy in postoperative infections after dorsal spinal surgery was studied retrospectively. Successful treatment was defined as a stable healed wound that showed no signs of acute or chronic infection. The treatment of the infected back wounds consisted of repeated debridement, irrigation and open wound treatment with temporary closure by V.A.C. The instrumentation was exchanged or removed if necessary. Fifteen patients with deep subfascial infections after posterior spinal surgery were treated. The implants were exchanged in seven cases, removed completely in five cases and left without changing in one case. In two cases spinal surgery consisted of laminectomy without instrumentation. In two cases only the wound defects were closed by muscle flap, the remaining ones were closed by delayed suturing. Antibiotic treatment was necessary in all cases. Follow up was possible in 14 patients. One patient showed a new infection after treatment. The study illustrates the usefulness of V.A.C. therapy as a new alternative management for wound conditioning of complex back wounds after deep subfascial infection.     

928株革兰阴性杆菌耐药性监测

目的：了解青岛地区临床分离的重要革兰阴性杆菌的耐药情况以指导合理用药。方法：2001年青岛3家医院临床分离的5种革兰阴性杆菌用Kirby-Bauer法进行药敏试验。结果：5种病原菌均占3家医院革兰阴性杆菌分离率的前5位，大肠埃希菌对氟喹诺酮类药物的耐药率达60％－87％，细菌对亚胺培南均呈高度敏感，但铜绿假单胞菌耐亚胺培南株占25．8％，头孢他啶的抗菌活性是三代头孢菌素中最高的；复方酶抑制剂表现出良好的抗菌活性。结论：细菌耐药问题仍是目前临床的严重问题，地域性的耐药性监测是必要的。     

Massive Immune Hemolysis Caused by Anti-D After Dual Kidney Transplantation

Massive immune hemolysis due to passenger lymphocyte-derived anti-D has not been reported in renal transplantation. A 50-year-old (B-positive) male received a dual deceased-donor kidney transplant (B-negative) for diabetic renal failure. Two weeks post-transplant, the patient developed severe hemolytic anemia. The donor anti-D titer was 1:8. The recipient anti-D titer (zero pre-transplant) increased from 1:4 to 1:16 over 4 days. Rapid hemolysis caused severe anemia, minimum Hb = 4.2 g/dL, while selectively lysing the patient's autologous red cells during this time. The hemolytic anemia did not impair the allografts and subsided without monoclonal B-cell pharmacotherapy or apheresis. The anti-D titer decreased to barely detectable levels at four months and had cleared when checked 2 years post-transplant. Transfusion support subsided after two months. If complications of anemia can be avoided, the deleterious effects of hemolysis may be well tolerated by renal allografts using antigen negative transfusion alone.     

美哌隆对麻醉的正常血压大鼠的降压作用

我们用麻醉的正常血压大鼠,大鼠的自体灌液后肢分别研究了美哌隆的降压作用强度、部位、维持时间和对心率的影响。实验结果提示:美哌隆降低动脉血压的作用除依赖于它对外周α_1受体的选择性阻滞外,还依赖于它对外周阻力血管的直接扩张作用。美哌隆在降压的同时也减慢心率,其降压作用和负性频率作用与剂量有关。     

Rh血型不合新生儿溶血病检测方法及应用

产前检测Ｒｈ，Ｄ因子及抗人球蛋白（ｃｏｏｍｂｓ）试验是必要的。测定Ｒｈ，Ｄ因子及抗Ｄ滴度使用木瓜酶方法。通过对１１２６１例孕妇常规检查Ｒｈ，Ｄ因子，发现Ｄ阴性７４例。Ｒｈ，Ｄ阴性妇女占６．５‰。２２例Ｒｈ，Ｄ阴性的孕妇所分娩的新生儿均为Ｒｈ，Ｄ阳性。其中２例孕妇血清抗Ｄ滴度为１∶３２，病情严重，宫内输血无效，胎死宫内。初产妇１３例，占５９％。活产２０例，存活率９０％。Ｒｈ因子及抗人球蛋白试验方法简便、易行，一般医院均可进行。对有流产史、输血史的孕妇检查Ｒｈ因子是十分必要的。在有条件的医院，对Ｒｈ，Ｄ阴性的产妇分娩Ｒｈ，Ｄ阳性的新生儿之后，产妇应预防性注射抗Ｄ免疫球蛋白     

高质量电镜影象幻灯片的简便制作方法

使用135单镜头反光照相机和近摄接圈,加置一个普通印相晒箱,即可对电镜底片直接成像,精确的曝光,配合标准程序冲洗,一步制成135幻灯片。其质量优良,且简便可靠、省工省时、节约材料,能大大提高工作效率。本文较为详细地介绍了具体操作方法及要点,并对其它常用制作方法亦做了分析讨论。     

Sulpiride in negative schizophrenia: A placebo-controlled double-blind assessment

Twenty-four chronic schizophrenic long-stay hospital patients were identified, who had not received neuroleptic drugs for 8–30 (average 8 months) and met or exceeded a minimum criterion of severity of negative symptoms. They were rendomly alocated to either sulpiride 200 mg twice daily or matching placebo, on a double-blind basis for 12 weeks. The results showed that low-dose sulpiride was significantly better than placebo in relation to improvements in negative symptoms. The changes in social behaviour were complex and not obviously related to symptom improvement; exhibited abnormal behaviour, a major factor in preventing successful return to the community, consistently improved only on the active drug.     

Evaluating risk factors associated with severe hypoglycaemia in epidemiology studies—what method should we use?

AIMS: To determine the most appropriate regression models to use when assessing risk factors for severe hypoglycaemia and to investigate the impact of model misspecification and its clinical implications. METHODS: A total of 1229 children with Type 1 diabetes (mean age 11.7 years sd 4.1), of which 605 (49.2%) were males, were studied. Prospective assessment of severe hypoglycaemia (an event leading to loss of consciousness or seizure) was made over the 9-year period, 1992-2001. Patients were seen every 3 months and episodes of hypoglycaemia along with clinical data were recorded. Over 70% of children never experienced a severe hypoglycaemic event. Data were analysed using the Poisson regression, negative binomial, zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) models. The over-dispersion and likelihood ratio statistics were calculated and the analytical methods compared. RESULTS: The Poisson regression model did not fit the data well. The negative binomial and the zero inflated Poisson and negative binomial models fitted the data better than Poisson. CONCLUSIONS: The commonly used Poisson regression models to analyse hypoglycaemia epidemiology may lead to biased parameter estimates and incorrect determination of risk factors for hypoglycaemia. We recommend the use of the negative binomial or zero inflated models to examine any risk factors associated with severe hypoglycaemia. Careful consideration must be given to the interpretation of hypoglycaemia surveys and their analysis.     

论高校大学生绿色网络环境的营造

介绍了网络文化的迅猛发展对高校大学生的学习方式、生活方式、交往方式产生了巨大冲击,尤其对大学生的身心发展产生了不可忽视的消极影响。指出在高校信息化校园建设中,要加强网络文明的建设,提倡和重视绿色网络,并且从高校大学生的实际出发,努力营造一个健康、文明、有序、安全、具有活力、没有污染的绿色网络环境。