Cysteine Conjugate beta-Lyase-Dependent Metabolism of Compound A (2-[fluoromethoxy]-1,1,3,3,3-pentafluoro-1-propene) in Human Subjects Anesthetized with Sevoflurane and in Rats Given Compound A

Background: Sevoflurane undergoes Baralyme- or soda lime-catalyzed degradation in the anesthesia circuit to yield compound A (2-[fluoromethoxy]-1,1,3,3,3-pentafluoro-1-propene), which is nephrotoxic in rats and undergoes metabolism via the cysteine conjugate beta-lyase pathway in those animals. The objective of these experiments was to test the hypothesis that compound A undergoes beta-lyase-dependent metabolism in humans.

Methods: Human volunteers were anesthetized with sevoflurane (1.25 minimum alveolar concentration, 3%, 2 l/min, 8 h) and thereby exposed to compound A. Urine was collected at 24-h intervals for 72 h after anesthesia. Rats, which served as a positive control, were given compound A intraperitoneally, and urine was collected for 24 h afterward. Human and rat urine samples were analyzed by19 F nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry for the presence of compound A metabolites.

Results: Analysis of human and rat urine showed the presence of the compound A metabolites [S-[2-(fluoromethoxy)-1,1,3,3,3-pentafluoropropyl]-N-acetyl-L-cysteine, (E)- and (Z)-S-[2-(fluoromethoxy)-1,3,3,3-tetrafluoro-1-propenyl]-N-acetyl-L-cyst eine, 2-(fluoromethoxy)-3,3,3-trifluoropropanoic acid, 3,3,3-trifluorolactic acid, and inorganic fluoride. The presence of 2-(fluoromethoxy)-3,3,3-trifluoropropanoic acid and 3,3,3-trifluorolactic acid in human urine was confirmed by gas chromatography-mass spectrometry.     

高血糖对非胰岛素依赖型糖尿病患者红细胞（Ca~（2＋）－Mg~（2＋））－ATP酶的影响

为了解高血糖对非胰岛素依赖型糖尿病（ＮＩＤＤＭ）患者红细胞膜（Ｃａ２＋－Ｍｇ２＋）－Ａｒｐ酶的影响，采用改良的Ｈａｎａｈａｎ和Ｌｕｔｈｒａ法测定了红细胞膜（Ｃａ２＋－Ｍｇ２＋）－ＡＴＰ酶活性。结果表明，ＮＩＤＤＭ患者红细胞膜（Ｃａ２＋－Ｍｇ２＋）－ＡＴＰ酶活性降低，且与空腹血糖、糖化血红蛋白、果糖胺及红细胞变形指数呈负相关，后者与红细胞内Ｃａ２＋浓度呈正相关。说明（Ｃａ２＋－Ｍｇ２＋）－ＡＴＰ酶活性下降时，红细胞变形能力降低，可能与患者红细胞膜蛋白的过度糖化及细胞内Ｃａ２＋浓度的增高有关。     

直肠癌患者手术前后MG—Ags的表达及临床意义

用免疫放射法测定31例直肠癌患者血清MG-AgS水平,并与26例结肠息肉组进行对比。结果发现:直肠癌组术前血清MG-AgS水平显著高于对照组(P＜0.01);手术前后血清MG-AgS水平差异显著,术前高于术后(P＜0.01);术前MG-AgS水平与病理分期关系密切,随病理分期增加而升高;术后复发组血清MG-AgS水平高于无复发组(P＜0.01)。提示MG-AgS测定有助于直肠癌的诊断、治疗和对预后的估计。     

“强力”饮料对大鼠心肌组织化学的影响

“强力”饮料是增强体质的强壮饮料,内含多种氨基酸、微量元素和维生素。临床观察和动物试验已证明可改善人和动物的运动能力。30支Wistar雄性大鼠随机地分为三组:实验Ⅰ组、实验Ⅱ组和对照组。实验Ⅰ组每日服“强力”饮料,实验Ⅱ组每日服水。观察10天后,实验组Ⅰ和Ⅱ配对进行最大游泳试验。左心肌进行了下述组化反应:糖原:Akpase,ACPase ATPase和SDH。结果说明实验Ⅰ组和Ⅱ组的糖原,AKPase和ACPase之间存在明显的差异。结论为强力饮料可能改善或延缓大鼠运动时心肌缺血。     

Mutations in the retinal guanylate cyclase (RETGC-1) gene in dominant cone-rod dystrophy

The dominant cone-rod dystrophy gene CORD6 has previously been mapped to within an 8 cM interval on chromosome 17p12-p13. The retinal- specific guanylate cyclase gene (RETGC-1), which maps to within this genetic interval and previously was implicated in Leber's congenital amaurosis, was screened for mutations within this family and in a panel of small families and individuals with various cone and cone- rod dystrophy phenotypes. A missense mutation (E837D) was identified in affected members of the CORD6 family, as well as a second missense mutation (R838C) in three other families with dominant cone-rod dystrophy. RETGC-1 is only the fourth gene to be implicated in cone-rod dystrophy and this is the first report of dominant mutations in this gene.      

Real-time PCR检测风疹病毒方法学建立及临床应用

为了建立一种能广泛应用于临床快速、简便、灵敏度和特异性较好的风疹病毒(RV)定量诊断方法。针对RV基因保守序列设计两对引物和一条荧光双标记探针。将PCR扩增所得到的产物片段克隆,作为定量检测的标准品,进行Real-time PCR检测,绘制标准曲线。将此方法和ELISA试剂盒平行检测50份孕妇血清,评估两种方法检出阳性率的差异显著性。Real-time PCR法能较好地检出RVcDNA载量。曲线的相关系数(r)为0.998,可检测线性范围大约在103~109copies/μl,灵敏度接近103copies/μl;批间、批内CV值分别为3.36%、0.94%;也有较好的特异性。与经典的ELISA方法相比,有显著性差异。Real-time PCR方法操作简单、快速,并能避免PCR后处理导致的假阳性污染,实现实时定量。此方法对RV感染的临床诊断和疗效判断等方面有较大的指导意义。     

切应力作用下肾近端小管上皮细胞纤溶酶原激活物(tPA和uPA)表达的变化及意义

检测切应力作用下肾近端小管上皮细胞纤溶酶原激活物tPA和uPA mRNA表达的变化,探讨糖尿病肾病早期小管间质细胞外基质重塑的可能机制.用5 dyn/cm2和10 dyn/cm2的切应力处理肾近端小管上皮细胞(NRK-52E),作用时间分别为1、3和6 h,用RT-PCR法检测tPA及uPA mRNA的表达.结果表明:切应力呈大小和时间依赖性下调肾小管上皮细胞tPA及uPA mRNA的表达.在糖尿病肾病早期,高滤过引起的切应力增加可抑制肾近端小管上皮细胞tPA和uPA mRNA表达,导致肾小管间质纤维蛋白溶解活性降低,参与小管间质细胞外基质的重塑.     

Formaldehyde in cryoprotectant propanediol and effect on mouse zygotes

Cryopreservation of human zygotes and embryos has been routinely performed by in-vitro fertilization clinics for many years. Karran and Legge (1996) first reported that formaldehyde (FA) present in the cryoprotective solutions can have a deleterious effect on mouse oocytes. FA is a cytotoxic, carcinogenic and mutagenic chemical. The effect of FA on mouse zygotes was investigated. In addition, the concentrations of FA in propanediol (PROH) obtained from various sources were determined. Pooled 1-cell embryos were dispensed into droplets of modified Ham's F10 or human tubal fluid containing various concentrations of FA. Since bovine serum albumin (BSA) may minimize toxicity additional trials were done as above in the absence of BSA. FA concentration in the standard 1.5 M PROH, from different sources in water, was measured in the same assay using a standard curve of 0-100 microM FA. FA in a complex medium had a significant deleterious effect on embryo development and hatching but only at 1 mM concentration (P < 0.000001; see Tables I-III). There was no significant effect of FA at 100 microM. However, in a simple medium even 50 microM FA decreased embryo hatching. FA was present in 1.5 M PROH from different sources (range 1.0-35.3 microM concentration). It appears that FA concentrations do not increase with storage because FA concentrations were low even after opening and storage for 3 years on the shelf. This suggests that FA is a contaminant during the manufacturing process and may vary from manufacturer to manufacturer and batch to batch. Until further studies are done to confirm the lack of toxicity to embryos during cryopreservation (with or without FA scavengers) it may be prudent to screen all batches of cryoprotectants for FA as part of quality control.      

High throughput parallel analysis of hundreds of patient samples for more than 100 mutations in multiple disease genes

As more mutations are identified in genes of known sequence, there is a crucial need in the areas of medical genetics and genome analysis for rapid, accurate and cost-effective methods of mutation detection. We have developed a multiplex allele-specific diagnostic assay (MASDA) for analysis of large numbers of samples (> 500) simultaneously for a large number of known mutations (> 100) in a single assay. MASDA utilizes oligonucleotide hybridization to interrogate DNA sequences. Multiplex DNA samples are immobilized on a solid support and a single hybridization is performed with a pool of allele-specific oligonucleotide (ASO) probes. Any probes complementary to specific mutations present in a given sample are in effect affinity purified from the pool by the target DNA. Sequence-specific band patterns (fingerprints), generated by chemical or enzymatic sequencing of the bound ASO(s), easily identify the specific mutation(s). Using this design, in a single diagnostic assay, we tested samples for 66 cystic fibrosis (CF) mutations, 14 beta-thalassemia mutations, two sickle cell anemia (SCA) mutations, three Tay-Sachs mutations, eight Gaucher mutations, four mutations in Canavan disease, four mutations in Fanconi anemia, and five mutations in BRCA1. Each mutation was correctly identified. Finally, in a blinded study of 106 of these mutations in > 500 patients, all mutations were properly identified. There were no false positives or false negatives. The MASDA assay is capable of detecting point mutations as well as small insertion or deletion mutations. This technology is amenable to automation and is suitable for immediate utilization for high-throughput genetic diagnostics in clinical and research laboratories.