A -243A-->G polymorphism upstream of the gene encoding GAD65 associates with lower levels of body mass index and glycaemia in a population-based sample of 5857 middle-aged White subjects.

AIMS: The glutamate decarboxylase gene (GAD2) encodes GAD65, an enzyme catalysing the production of the gamma-aminobutyric acid (GABA) which interacts with neuropeptide Y to stimulate food intake. It has been suggested that in pancreatic islets, GABA serves as a functional regulator of pancreatic hormone release. Conflicting results have been reported concerning the potential impact of GAD2 variation on estimates of energy metabolism. The aim of this study was to elucidate potential associations between the GAD2-243A-->G polymorphism and levels of body mass index (BMI) and estimates of glycaemia. METHODS: Using high-throughput chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, the GAD2-243A-->G (rs2236418) polymorphism was genotyped in a population-based sample (Inter99) of 5857 middle-aged, unrelated Danish White subjects. RESULTS: The G-allele was associated with modestly lower BMI (P = 0.01). In a case-control study of obesity, the G-allele frequency in 2582 participants with BMI < 25 kg/m2 was 19.5% (18.4-20.6) compared with 17.1% (15.5-18.8) in 968 participants having BMI > or = 30 kg/m2 (P = 0.03), odds ratio 0.9 (0.7-1.0). Of the 5857 subjects, GG carriers had lower fasting plasma glucose levels (mmol/l) [AA (n = 3859) 5.6 +/- 0.8; AG (n = 1792) 5.5 +/- 0.8; GG (n = 206) 5.5 +/- 0.8, P = 0.008] and lower 30-min oral glucose tolerance test (OGTT)-related plasma glucose levels (AA 8.7 +/- 1.9; AG 8.6 +/- 1.9; GG 8.6 +/- 2.0, P = 0.04), adjusted for sex, age and BMI. Analysing subjects who were both normoglycaemic and glucose tolerant (n = 4431) GG carriers still had lower fasting plasma glucose concentrations: AA (n = 2895) 5.3 +/- 0.4; AG (n = 1383) 5.3 +/- 0.4; GG (n = 153) 5.2 +/- 0.4 (P = 9.10(-5)). CONCLUSION: The present study suggests that the GAD2-243A-->G polymorphism in a population of middle-aged White people associates with a modest reduction in BMI and fasting and OGTT-related plasma glucose levels.     

肿瘤坏死因子凋亡相关配体基因的克隆和表达

目的：克隆、表达和鉴定肿瘤坏死因子凋亡相关配体(TRAIL)．方法：从培养的人外周血淋巴细胞中提取总RNA，经RT-PCR获得TRAIL基因．将该基因克隆到pGEM-Teasy载体中，测序鉴定．将TRAIL基因插入pBV220表达载体中，42℃诱导表达4～5h，进行SDS-PAGE分析．免疫印迹法鉴定TRAIL蛋白的表达．结果：DNA测序证明，获得了TRAIL基因，其序列与GenBank中报道序列完全一致．SDSPAGE分析表明，TRAIL蛋白获得高效表达，分子质量为17ku，表达量约占菌体总蛋白的300k，．免疫印迹法鉴定显示，该蛋白可与鼠抗人TRAIL mAb产生阳性反应．结论：成功克隆和表达了TRAIL基因．     

Diplotypes of the human serotonin 1B receptor promoter predict growth hormone responses to sumatriptan in abstinent alcohol-dependent men.

BACKGROUND: Some studies have associated alcohol dependence (AD) with the human serotonin (5-HT)(1B) receptor (HTR1B). This investigation explored the functional responsivity of HTR1B in abstinent AD men using a sumatriptan challenge, while measuring genetic heterogeneity in the HTR1B promoter. METHODS: Abstinent AD men (n = 27) and abstinent men without any alcohol use disorder (n = 19) were administered 6 mg of sumatriptan succinate, subcutaneously. Plasma samples collected over the following 2 hours were assayed for growth hormone (GH) concentrations. His DNA was genotyped for the A-161T and T-261G polymorphisms of the HTR1B promoter and diplotypes determined. RESULTS: Integrated GH responses were predicted by interactions of AD and promoter diplotypes, as well as subject ethnicity. The final model accounted for nearly 35% of the variance in GH responses. Post hoc evaluation revealed that AD was associated with a blunting of GH secretion only among individuals with the most common HTR1B diplotype (TT/TT). CONCLUSIONS: A blunting of GH responses in abstinent AD men was observed only among those with the most common HTR1B promoter diplotype. Less common promoter diplotypes appeared protective. Controlling for genetic background is a useful augmentation of case-control pharmacological challenge strategies designed to elucidate the psychobiology of AD and other complex disorders.     

Cow's Milk Exposure and Asthma in a Newborn Cohort: Repeated Ascertainment Indicates Reverse Causation

The effect of cow's milk consumption on childhood asthma has been debated for several years. This study attempts to provide further insight into this association through the use of a longitudinal study design. Newborns from parents with atopic history were recruited from Germany, Austria, and England (n = 696). For five repeated ascertainments, information was collected on cow's milk exposure, incidence of doctor-diagnosed asthma, and confounders. Generalized estimation equations, incorporating different models (concurrent, delayed, combined, and reverse causation), were used to determine this association. No association between cow's milk consumption and childhood asthma was found for the concurrent effects model (OR = 0.81, 95% confidence interval [CI]: 0.55, 1.20). In the delayed effects model, the direction of the association varied with time of follow-up. Thus, we stratified by period, which resulted in a significant protective delayed effect at 36 months (OR = 0.18, 95% CI = 0.06, 0.49). However, reverse causation negated this finding since the presence of asthma in prior months led to a reduction in further exposure to cow's milk (OR = 0.40, 95% CI = 0.16, 0.99). Hence, cow's milk consumption does not protect against childhood asthma. The apparent protection of cow's milk against asthma may result from parents of asthmatic children avoiding cow's milk, rather than actual prophylaxis.     

纤溶酶原激活剂抑制物-1及其基因多态性与急性心肌梗死的相关性研究

目的：研究纤溶酶原激活剂抑制物－1（PAI－1）活性及其等位基因多态性与急性心肌梗死（AMI）之间的关系，从基因水平揭示AMI发病的危险因素。方法：AMI组55例、对照组48例健康者分别应用特异性寡核苷酸点膜杂交技术，进行PAI－1启动子区4G／5G多态性分析，用发色底物法测定血浆PAI－1活性。结果：AMI组和对照组中4G／4G基因型的血浆PAI－1活性水平最高，与4G／5G基因型、5G／5G基因型比较有显著性差异（P＜0．01）。AMI组中4G／4G纯合子基因型频率明显高于对照组（P＜0．05）。结论：血浆PAI－1活性增高是AMI发病的危险因素之一，4G／4G纯合子基因型是AMI发病的危险基因型。     

The regulation of pulmonary vascular tone

1 The ability to manipulate pharmacologically pulmonary vascular tone independent of effects on systemic blood vessels is a desirable objective. Elucidation of the biochemical mechanisms underlying hypoxia-induced pulmonary vasoconstriction (HPV) may permit preferential targeting of the pulmonary circulation.
2 Here we review our studies of the role of locally synthesized candidate vasoactive factors in HPV. In addition, we present data demonstrating an attenuated pressor response to hypoxia in the pulmonary circulation of Fischer 344 rats compared with the Wistar-Kyoto (WKY) rat strain.
3 We propose that a systematic genome-wide search using the HPV phenotype and a panel of highly informative microsatellite markers will elucidate the genetic loci underlying the difference in susceptibility to HPV in these two rat strains and provide a valuable and novel insight into the factors that determine the HPV response.     

Using the polymerase chain reaction to maintain DNA probe inventories in clinical and diagnostic laboratories

Clinical and diagnostic DNA laboratories must maintain a large inventory of DNA probes for use in hybridization studies. The preparation of plasmid DNA and isolation of DNA fragments for use as probes in both expensive and time consuming. We present here a rapid and relatively inexpensive method of producing large amounts of DNA fragments from stocks, using the polymerase chain reaction (PCR). Our experience over the past year using this technique has been very positive and we believe many laboratories could benefit by employing such a labor-saving approach to maintaining DNA probes. The technique uses the bacteriophage M13 DNA sequencing primers to amplify cloned inserts contained in commonly used plasmid vectors. As examples, we illustrate the use of DNA produced in this manner as probes for linkage analysis of the fragile X syndrome and for detection of deletions in the Duchenne muscular dystrophy gene. We have also found that at least two probes can be amplified in the same PCR reaction, allowing the detection of two different restriction fragment length polymorphisms (RFLP) simultaneously. It should be possible for laboratories to devise strategies particular to their individual needs using more than one DNA probe produced in the same PCR reaction to detect RFLP's. Such strategies would need only to consider that the predicted alleles of the multiple polymorphisms do not migrate to the same position during electrophoresis. Stocks of single or multiple probes produced by the PCR could then be maintained for more rapid Southern analyses.     

API2对黏膜相关淋巴瘤凋亡及凋亡相关蛋白的影响

目的：了解黏膜相关淋巴瘤的凋亡水平及其所涉及到的信号传导通路。方法：收集33例胃肠黏膜相关淋巴样组织(MALT)淋巴瘤病例，通过TUNEL技术原位检测MALT淋巴瘤肿瘤细胞的凋亡水平，通过逆转录聚合酶链反应(RT-PCR)和免疫组织化学染色检测肿瘤的凋亡抑制蛋白2编码基因(API2)和Caspase3 mRNA及蛋白，对API2和Caspase3水平作半定量和定量分析。根据凋亡检测结果将全部病例分为两组，即凋亡细胞数每50个高倍视野小于或等于2的病例组和大于2的病例组，比较2组的API2和Caspase3 mRNA及蛋白。结果：半数以上的MALT淋巴瘤中存在凋亡抑制；凋亡抑制的MALT淋巴瘤病例中API2 mRNA及蛋白水平明显高于没有明显凋亡抑制的病例，但Caspase3 mRNA及蛋白水平在两组病例中表达没有明显的差异。结论：MALT淋巴瘤中存在明显的凋亡抑制，其发生与凋亡抑制因子API2的表达上调有关，但API2对凋亡的调节与Caspase3有关的信号传导通路无明显相关。