Analysis of clozapine response and polymorphisms of the dopamine D4 receptor gene (DRD4) in schizophrenic patients

We have examined the hypothesis that a variable number of tandem repeats in the third cytoplasmic loop of the dopamine D4 receptor influences clinical response to clozapine using a sample of 189 schizophrenic patients. Alleles of the 48-bp repeat, which range from two to ten copies in the normal human population, were analysed by the polymerase chain reaction using genomic DNA as template. Association between these alleles and response to clozapine was tested using the difference in pre-and post-treatment GAS scores as a measure of response. We found no statistically significant variation between genotypic groups and response by analysis of variance. We conclude that the variation of the number of 48-bp repeats alone does not determine response to clozapine. Larger studies are underway to determine if there is a more subtle relationship with sequence variation within the repeats or at other polymorphic sites within the gene that may provide evidence for a component of clozapine's action being at D4 receptors. © 1995 Wiley-Liss, Inc.     

HLA-DR 52- and 51-associated DRB1 alleles in Kenya, East Africa

The genes of the major histocompatibility complex (MHC) are amongst the most polymorphic loci known in the human population. The population genetics of the MHC encoded HLA loci of sub-Saharan Africa are of major interest because of their particular genetic diversity. Here we report on the HLA-DR 52- and 51-associated determinants of the DRB1 loci observed in 165 East African individuals studied in Nairobi, Kenya. The HLA-DR typing was done by serologic and by molecular DNA techniques (PCR-SSOP). The most frequent allele identified was DRB1*1101, followed by DRB1*1503 and DRB1*1302. Some unexpected alleles were repeatedly identified: DRB1*1108, DRB1*1316 and DRB1*1421. Most oftheDR 52-and 51-associated DRB1 alleles were correctly identified by serology as part of the DR3, DR5, DR6 and DR2 groups respectively. The HLA-DRB1 profile reported here corroborates previous genetic and linguistic data supporting the concept that the Eastern African Black population is genetically distinct from other African Black populations. This has important implications in public health issues related to the genetic profile of a population (transplantation, vaccine design for example).     

反相HPLC法同时测定饮料中的两种人造甜味剂

应用反相HPLC法，探讨了同一色谱条件下，食品中安赛蜜，糖精钠、咖啡因及苯甲酸的分离条件，并在此基础上建立了饮料中人造甜味剂安赛蜜、糖精钠的测定方法，取得了满意的结果。在反相C_(18)柱上，使用甲醇-冰乙酸-水（20+3.5+76.5）为流动相，可使安赛蜜、糖精钠、咖啡因，苯甲酸快速而良好地分离，254nm波长下检测，安赛蜜的线性范围为0.002～1.00g／L，最小检测量为0.04μg；糖精钠的线性范围为0.005～1.00g／L，最小检测量为0.08μg，在饮料分析中，外标单点校正法测得数据再用标准添加法处理进而求出的回收率分别为安赛蜜97.6％（n=5,CV=0.74%)、103.5%（n=5，CV=1.l%）、95.l%（n=5，CV=0.73%）；糖精钠97.9%（n=5，CV=0.66％）、99.9%（n=5，CV=0.73%)、102.1％（n=5，CV=0.18%）。本方法分析步骤简便，且检测波长适用于国产单波长检测器。     

非甲—戊型病毒性肝炎患者血清庚型肝炎病毒感染的研究

采用ＥＬＩＳＡ法及逆转录—ＰＣＲ（简称ＲＴ—ＰＣＲ）法检测３６例非甲—戊型肝炎患者血清庚型肝炎病毒抗体（简称抗ＨＧＶ）和庚型肝炎病毒（简称ＨＧＶＲＮＡ）。结果：７例（１９．４％）抗ＨＧＶ阳性，２例（５．４％）同时ＨＧＶＲＮＡ阳性；急性肝炎抗ＨＧＶ阳性者临床表现与抗ＨＧＶ阴性者无显著差异，慢性肝炎抗ＨＧＶ阳性者较抗ＨＧＶ阴性者轻。提示：ＨＧＶ可引起急、慢性肝炎，在非甲—戊型肝炎中占有一定比例，但不是主要原因。     

嗜肺军团菌聚合酶链反应检测方法及其应用研究

根据嗜肺军团菌基因组ＤＮＡ的种特异性ＤＮＡ片段序列，合成一对引物进行聚合酶链反应（ＰＣＲ）。经琼脂糖凝胶电泳、ＥＢ染色结果表明，一条８７０ｂｐ的核苷酸区带为嗜肺军团菌１～１４血清型菌株所共有。ＰＣＲ检测水中军团菌，其敏感性为３５０ｃｆｕ／ｍｌ，而用同位素标记探针、斑点杂交法检测，其敏感性为４３ｃｆｕ／ｍｌ。ＰＣＲ检测人工感染嗜肺军团菌的豚鼠组织标本，阳性率为８３．３％，而细菌分离培养的阳性率仅为２６．６％。在现场调查中，用ＰＣＲ法初步验证了一起由Ｌｐ１０引起的军团菌病爆发。上述结果表明，ＰＣＲ法能快速、敏感、特异性检测嗜肺军团菌感染。     

Fluorotyping of HLA-C: differential detection of amplicons by sequence-specific priming and fluorogenic probing

Conventional PCR-SSP, which is based on an agarose gel-based read-out, has the disadvantages of time-consuming post-PCR steps and low potential for automation. The aim of our study was to sort out these drawbacks by establishing a fluorescence-based PCR-SSP system for HLA-C. The assay relies on the sequence-specific identification of amplicons with individually labeled probes that are cleaved during successful PCR by the 5'-3' exonuclease activity of the Taq-DNA Polymerase. The oligonucleotides are labeled with a unique and spectrally resolvable fluorescent reporter dye at the 5' terminus (FAM or TET) and a common quencher dye at the 3' terminus (TAMRA). In case of amplification, the reporter escapes from the quenching control caused by the physical separation of the dyes, resulting in a significant increase of the reporter fluorescence. This allows simultaneous and differential detection of the specific HLA (FAM) and internal control (TET) product. The HLA-C fluorotyping information is based on the individual reporter fluorescence released by 18 PCR primer mixes. Using this method, we analyzed 145 samples previously typed with conventional PCR-SSP and found a concordance rate of 100%. Furthermore, fluorotyping revealed quantitative results that may indicate the presence of homozygosity by high signal intensities. This provided extra protection not to miss new alleles which are not amplified by the current primer mixes. These features as well as the capability of high sample throughput and the possibility of automation makes fluorotyping an attractive tool for PCR-based HLA typing.     

采用基因配型行同种异体肾移植术

目的 探讨基因配型技术在同种异体肾移植中的应用。方法采用顺序特异引物聚合酶链反应法(PCR-SSP)分别进行供、受体的基因分型，为3例配型适当的终末性肾病患者行同种异体肾移植术，并观察其术后肾功能恢复情况。结果所有接受肾移植的患者于术后2d肾功能恢复至正常水平，无急性和超急性排异发生。随访11-15个月，各项检查指标均正常。结论 基因配型的准确率较之传统的血清学配型显著增加，显著提高同种异体肾移植的成功率。