Transmission of genome damage from irradiated male rats to their progeny

The effect of gamma-radiation (3Gy) on slowly proliferating liver tissue of male rats and their progeny was investigated with respect to induction and duration of latent damage. The irradiation caused latent cytogenetic damage in the liver in irradiated males of the F(0) generation, which manifested itself in different ways during proliferation of hepatocytes induced by partial hepatectomy: a reduced proliferating activity, a higher frequency of chromosomal aberrations and a higher proportion of cells with apoptotic DNA fragments were observed, compared with non-irradiated rats. In the progeny of irradiated males (F(1) and F(2) generation), the latent genome damage manifested itself during regeneration of the liver after partial hepatectomy by similar, but less pronounced changes compared with those seen in irradiated males of the parental generation. This finding gave evidence of the transfer of part of the radiation-induced genome damage from parents to their offspring. Irradiation of F(1) and F(2) progeny of irradiated males (their total radiation load being 3 + 3 and 3 + 0 + 3 Gy, respectively) caused less change as irradiation of progeny of non-irradiated control males (their total radiation load being 0 + 3 and 0 + 0 + 3 Gy, respectively).     

探讨模拟冷空气降温过程对健康大鼠和高血压大鼠凝血功能的影响

目的:通过模拟冷空气温度变化过程给予健康大鼠和高血压大鼠冷刺激,以此探讨冷空气过程对机体凝血功能的影响。方法:收集张掖市2011年3月一次典型冷空气过程数据,利用气象环境模拟箱模拟其温度变化过程。将24只雄性健康大鼠和24只雄性高血压大鼠分别随机分成最低温组(Tmin组)、Tmin对照组、复温组(Tr组)和Tr对照组。将Tmin组和Tr组大鼠放入气候箱中暴露冷空气温度变化过程。在Tmin和Tr时点分别停止Tmin组大鼠和Tr组大鼠冷空气暴露,并采血以测定其凝血功能指标—凝血四项。结果:与对照组相比,健康大鼠和高血压大鼠活化部分凝血酶原时间(APTT)、凝血酶原时间(PT)、凝血酶时间(TT)在降温后与对照组相比没有显著差异(P>0.05),但血浆纤维蛋白原(Fbg)含量在高血压大鼠和健康大鼠Tmin组明显高于其对照组(P<0.01)。温度恢复后,其在健康组含量仍然高于其对照组(P<0.05),而在高血压大鼠中没有差异(P>0.05)。同Fbg,反应Fbg的纤维蛋白原时间(Fbg-time)在健康大鼠Tmin和Tr组中短于对照组(P<0.01,),而在高血压大鼠中仅在Tmin组短于对照组(P<0.01)。高血压大鼠血中的Fbg含量和Fbgt明显高于和短于健康大鼠(P<0.01)。结论:①冷空气降温过程能增加机体血中Fbg含量,使凝血功能增强,可能增加心血管疾病危险性;②冷空气刺激对健康大鼠凝血功能影响强于高血压大鼠。     

镉诱导金属硫蛋白在华溪蟹组织中的表达

采用体外暴露染毒法,研究了不同浓度与时间条件下,镉诱导河南华溪蟹(Sinopotamon henanense)金属硫蛋白(metallothionein,MT)在肝胰腺、肌肉、鳃和卵巢中的表达差异。镉浓度分别为0、14·5mg/L、29mg/L和58mg/L;处理时间依次为1d、3d和5d。利用镉血红蛋白饱和法和火焰原子吸收分光光度法(AAS)测定MT的蛋白含量。结果显示,用不同的染毒浓度和处理时间,镉在组织中诱导产生MT的含量有较大差异,其中肝胰腺MT的诱导量最大,变化规律也最明显;肌肉中也有较大量MT的表达;而鳃和卵巢MT的诱导量均较低。此外,本文分析了镉的浓度与时间梯度对诱导MT表达的影响与毒性效应机制。结论:组织不同,染毒浓度及时间不同,镉诱导MT的表达也不同,具有一定的组织差异性和规律性。     

利用癌功能类从癌基因组突变谱中识别癌基因

从大规模癌样本基因突变扫查数据中识别癌基因具有重要的意义. 一些重要功能的改变对于癌的发生发展是必需的, 因此将它们定义为癌功能类, 并从GO(Gene Ontology)中选择一组显著富集已知癌基因的细致功能类来代表它们. 为了评价以癌相关功能类作为特征识别癌基因的效果, 将已知的蛋白激酶癌基因定义为阳性金标准, 而将其他的蛋白激酶基因定义为阴性金标准. 结果表明, 与利用选择压力作为特征的方法比较, 利用癌相关功能类作为特征的方法可以更有效地识别癌基因. 进一步结合癌相关功能类与基因非同义突变个数可以产生更可靠的预测结果. 最后, 将46个注释到癌相关功能类并且其非同义突变个数至少为3的蛋白激酶基因预测为癌基因, 预测精确率达到0.42.     

Identification of bilirubin reduction products formed by Clostridium perfringens isolated from human neonatal fecal flora

Urobilinoids belong to the heterogenous group of degradation products of bilirubin formed in the gastrointestinal tract by intestinal microflora. Among them urobilinogen and stercobilinogen with their respective oxidation products, urobilin and stercobilin, are the most important compounds. The aim of present study was to analyze the products of bacterial reduction of bilirubin in more detail. The strain of Clostridium perfringens isolated from neonatal stools, capable of reducing bilirubin, was used in the study. Bacteria were incubated under anaerobic conditions with various native as well as synthetic bile pigments, including radiolabeled unconjugated bilirubin (UCB). Their reduction products were extracted from media and separated following thin layer chromatography. Pigments isolated were analyzed by spectrophotometry, spectrofluorometry and mass spectrometry. In a special set of experiments, bilirubin diglucuronide was incubated with either bacterial lysate or partially purified bilirubin reductase and beta-glucuronidase to reveal whether bilirubin glucuronides may be directly reduced onto conjugated urobilinoids. A broad substrate activity was detected in the investigated strain of C. perfringens and a series of bilirubin reduction products was identified. These products were separated in the form of their respective chromogens and further oxidized. Based on their physical-chemical properties, as well as mass spectra, end-catabolic bilirubin products were identified to belong to urobilinogen species. The reduction process, catalyzed enzymatically by the studied bacterial strain, does not proceed to stercobilinogen. Bilirubin diglucuronide is not reduced onto urobilinoid conjugates, glucuronide hydrolysis must precede double bond reduction and thus UCB is reduced much faster.     

Capillary isoelectric focusing of proteins and microorganisms in dynamically modified fused silica with UV detection

We suggest a method for the reproducible and efficient capillary isoelectric focusing of proteins and microorganisms in the pH gradient 3-10. The method involves the segmental injection of the simple ampholytes, the solution of the selected electrolytes, and the sample mixture of bioanalytes and carrier ampholytes to the fused silica capillaries dynamically modified by poly(ethylene glycol), PEG 4000, which is added to the catholyte, the anolyte and injected solutions. In order to receive the reproducible results, the capillaries were rinsed by the mixture of acetone/ethanol between analyses. For the tracing of the pH gradients the low-molecular-mass pI markers were used. The simple proteins and the mixed cultures of microorganisms, Saccharomyces cerevisiae CCM 8191, Escherichia coli CCM 3954, Candida albicans CCM 8180, Candida parapsilosis, Candida krusei, Staphylococcus aureus, Streptococcus agalactiae CCM 6187, Enterococcus faecalis CCM 4224, Staphylococcus epidermidis CCM 4418 and Stenotrophomonas maltophilia, were focused and separated by the method suggested. The minimum detectable number of microbial cells was 5x10(2) to 1x10(3) with on-column UV detection at 280 nm.     

Serodiagnostics of chlamydial infections--significance of positivity in IgA and/or IgM antibody classes only

There was followed the development of serological findings in patients with proved positivity only in classes IgA and/or IgM of chlamydial antibodies (without IgG), which can be suspected of showing "false" positivity. 184 patients were repeatedly examined for chlamydial antibodies in their sera (interval between collections up to three months) using a genus specific rELISA. Sera were also tested for the evidence of IgM antibodies against capside antigen of Epstein-Barr virus (EBV) and against cytomegalovirus (CMV) using ELISA methods. In 75 (40.8%) of patients, IgA/IgM individual positivities were demonstrated even during the following sample test(s). In 28 (15.2%) of them, IgG evidence preceded and in 29 (15.7%) other patients positive seroconversion followed in this class. In 13 (7.1%) patients, IgG antibodies disappeared and subsequently reappeared. Only in 39 (21.2%) of these probands, antibodies IgA/IgM were not demonstrated at another examination. Active EBV, resp. CMV infection was proved in 24 (13.0%), resp. in 18 (9.8%) of patients. It is concluded that the evidence of positivities only in classes IgA and/or IgM mostly signal the onset of a primary infection (reinfection) or an active infection in patients with IgG production failures respectively. In these cases, a "false" positivity can be supposed to occur only in a minor extent.     

Simple and rapid method determination for metformin in human plasma using high performance liquid chromatography tandem mass spectrometry: application to pharmacokinetic studies

A rapid and simple method for quantitation of metformin (MET) in human plasma by HPLC-MS/MS was developed and validated. The sample preparation consists of plasma deproteinization using acetonitrile. The mobile phase consisted of water-acetonitrile and formic acid (55/45/0.048, v/v/%) and the run time was 3 min. A pursuit C(18) (100 mm x 2.0 mm i.d., 3 microm) column connected to a guard column MS-pursuit (0.20 mm x 0.20 mm i.d., 5 microm) was used. The range of the calibration curve was from 20 to 5000 ng/mL, the limit of quantitation being 20 ng/mL. The detection was performed on a mass spectrometer (ESI+), using metoprolol as internal standard. The calibration curves have r(2) values of 0.995 (CV=0.24%, n=10). The accuracy and precision were between 90.74 and 106.7% and coefficients of variations (CV) of 1.10 and 4.35%, respectively. The method was applied to determine the pharmacokinetic parameters: C(max) (1667.25 ng/mL) and T(max) (3.89 h).     

新疆维吾尔族妇女宫颈癌组织中乳头瘤病毒16型E6基因的克隆和序列分析

为了分析新疆南部地区维吾尔族妇女宫颈癌组织中HPV16型E6基因结构特点，从中国新疆南部地区维吾尔族妇女宫颈癌活检组织标本中提取DNA，以宫颈癌活检组织标本DNA为模板进行PCR扩增，获得HPV16 E6基因，将其克隆到pUCm-T载体上，并对其进行基因全序列分析.PCR检测结果显示宫颈癌组织中HPV16 E6阳性率为82.35%（14/17）；测序结果显示，新疆株HPV16 E6基因全长456 bp，大小与德国标准株一致.E6基因的第247位碱基发生T→G突变，并由此引起所编码的氨基酸亦发生改变.上述结果表明，中国新疆南部地区维吾尔族妇女宫颈癌患者组织中HPV16 E6的基因结构与德国标准株HPV16 E6基因之间存在差异.