RENIN GENE POLYMORPHISM ASSOCIATED WITH ALDOSTERONE RESPONSIVENESS TO THE RENINANGIOTENSIN SYSTEM IN PATIENTS WITH ALDOSTERONE-PRODUCING ADENOMAS

1. Aldosterone levels in patients with unilateral aldosterone-producing adenomas may be responsive or unresponsive to the renin-angiotensin system, with the former often previously misdiagnosed as bilateral adrenal hyperplasia. 2. In tumours from patients in the responsive subgroup, renin mRNA is expressed in greater amounts than in tumours from patients in the unresponsive subgroup, or in normal adrenals. 3. We compared the frequency of four renin gene polymorphisms in peripheral blood DNA from the two subgroups and found significant associations between BglI, TaqI and HinfI restriction fragment length polymorphisms (RFLP) and aldosterone responsiveness. 4. Allelic variation in the constitutive renin gene was associated with a specific cause of hypertension.     

二甲亚砜对人表皮的核酸和蛋白质合成的影响

用体外培养的人的伪表皮作为模型，进行药物毒理学作用的研究，观察了二甲亚砜（ＤＭＳＯ）在不同浓度和不同接触时间条件下，对人的伪表皮细胞脱氧核糖核酸（ＤＮＡ）、核糖核酸（ＲＮＡ）和蛋白质合成的影响：随着接触时间的延长，ＤＮＡ、ＲＮＡ和蛋白质合成均受抑制。低浓度条件下（１％），ＤＮＡ、ＲＮＡ和蛋白质合成增加；在１５～５０％浓度下，ＤＮＡ和蛋白质合成抑制，而ＲＮＡ合成仍增加；在高浓度条件下（７０％～１００％），ＤＮＡ、ＲＮＡ和蛋白质合成均明显抑制。     

DNA probe technology: implications for service planning in Britain

For certain genetic conditions DNA testing identifies carriers and determines the risk status of foetuses, thus helping parents to make more informed prenatal decisions. Data, collected from three genetic centres in England and Wales from August 1986 to July 1990, are used to describe trends in demand for DNA testing, the impact of DNA tests on carrier risk assessment, and the use of DNA tests in relation to pregnancy outcome. Altogether the data include 23,388 subjects and 681 pregnancies in 8738 families divided into five cohorts by year of entry and referral. The most frequent gene disorders referred to the genetic centres are currently being tested or will soon be tested. For these disorders the initial high level of activity has declined and may have reached steady state. Demand for DNA services is high for cystic fibrosis and Duchenne muscular dystrophy, intermediate for Huntington's disease, and low for adult polycystic kidney disease, phenylketonuria and tuberous sclerosis. Based on these findings we suggest that demand for DNA tests will be high in serious, untreatable and slow progressing conditions with early onset; intermediate for conditions affecting intellect and neurological integrity with later onset; and low for treatable, late-onset conditions, or those for which there is evidence of heterogeneity, and variable penetrance. It would be helpful to assess the extent to which this view of demand is confirmed when the new disorders being DNA tested are considered and for the pattern of activity of DNA testing for some types of cancer. Since no DNA centre could offer a fully comprehensive testing service, it is recommended that a structure is created to audit overall activity, assist in policy formulation, and influence supraregional service organisation, in order that the spread of DNA services be planned as effectively as possible. This structure would facilitate monitoring of the evolution of contract specifications agreed by commissioners and providers on a regional basis.     

PUVA治疗诱导皮肤线粒体DNA 4977 bp缺失突变累积的研究

为探讨线粒体DNA(mitochondrialDNA,mtDNA)4977bp缺失突变与皮肤光老化之间的关系,采用三条引物PCR的方法检测长波紫外线光化学疗法(PUVA)治疗的银屑病患者背部非皮损区皮肤mtDNA4977bp缺失突变的累积。结果发现,在PUVA治疗期间3～21天、治疗后1～6个月和治疗后6个月以上的各组活检标本中,发生4977bp缺失突变的mtDNA占总mtDNA比例分别为0.06,0.12和0.19,和未经PUVA治疗的对照组比较均有显著性差异(P<0.01)。表明线粒体DNA4977bp缺失突变累积与皮肤光老化密切相关,可能作为衡量皮肤紫外线损伤程度的分子生物学标志。     

癌胚抗原DNA疫苗对大肠癌特异性细胞免疫的激活效果

目的检测以质粒pIRES为载体构建的带有全序列癌胚抗原(CEA)基因的核苷酸疫苗对机体特异性抗肿瘤免疫反应的激活效果。方法将CEA基因片段连接于真核表达质粒pIRES中,用肌肉注射方法接种核酸疫苗;检测CEA在小鼠肌肉组织中的表达情况及其对小鼠脾细胞CEA特异性细胞免疫反应的激活效果。结果小鼠经肌肉注射质粒后,免疫组化证实该核酸疫苗可在体内有效表达CEA;分子免疫检测显示注射后小鼠特异性淋巴细胞增值反应明显并且伴有自然杀伤细胞NK活性显著增高。结论实验所构建的核酸疫苗pIRESCEA可在体外及小鼠体内高效表达并表现出良好的细胞免疫原性。     

Epstein-Barr virus DNA in Reed-Sternberg cells of Hodgkin''s disease is frequently associated with CR2 (EBV receptor) expression

We studied 44 cases of Hodgkin's disease for the presence of Epstein-Barr virus (EBV) DNA, its localization and the expression of the EBV receptor on the tumour cells. EBV DNA was found in 52% (16/31) of the Hodgkin's lymphomas using the polymerase chain reaction. With a very sensitive non-radioactive DNA in situ hybridization technique in combination with immunohistochemistry for CD 30 or CD 15 antigens, EBV DNA was localized to Reed-Sternberg cells and its mononuclear variants. The relationship between the presence of EBV DNA and the expression of the EBV-receptor CR2 (CD 21) on Reed-Sternberg cells was studied using the same techniques and two different monoclonal anti-CD 21 antibodies. CR2 could be detected on a substantial number of the Reed-Sternberg cells in EBV DNA positive Hodgkin's lymphomas (9/12; 75%), whereas in EBV negative cases positivity with anti-CD 21 was rare (1/13; 8%). The results indicate that CR2 expression on Reed-Sternberg cells and the presence of EBV DNA sequences are frequently associated in Hodgkin's lymphomas.     

人抵抗素基因cDNA的克隆

目的克隆人抵抗素基因(hRETN)cDNA,为进一步研究RETN的结构和功能提供实验基础.方法应用RT-PCR方法从中国人网膜脂肪垫总RNA中扩增出RETN 基因cDNA,克隆入载体pMD18-T中,形成重组载体pMD18-T/hRETN.通过蓝白斑筛选出阳性克隆,限制性内切酶酶切鉴定后对其进行测序.结果从脂肪组织总RNA中扩增得到363 bp片段hRETN基因,其cDNA序列与Genbank hRETN基因序列基本相同.结论成功地克隆中国人hRETN cDNA.     

Standardized molecular typing of Candida albicans strains

Summary. A method is presented for the standardization of Candida albicans DNA fingerprinting, which is based on Southern hybridization of Eco RI-digested chromosomal DNA with the moderately repetitive DNA element CARE-2 and the subsequent rehybridization of the blots with a molecular size marker also included in each DNA sample. This method resulted in extremely precise alignment of all strain-specific CARE-2 hybridization patterns, even when analysed on different gels, and will enhance the accuracy of genetic relationship determinations in epidemiological studies including large numbers of strains.
Zusammenfassung. Zur Standardisierung des DNA-Fingerprinting von Candida albicans wurde eine Methode entwickelt, die auf der Southern Hybridisierung Eco RI-gespaltener chromosomaler DNA mit dem mittelrepetitiven DNA-Element CARE-2 und der darauffolgenden Rehybridisierung der Blots mit einem auch in den Proben enthaltenen molekularen Größenmarker beruht. Dies resultierte in einer äußerst präzisen Größen-bestimmung der hybridisierenden Fragmente, so daß alle stammspezifischen CARE-2-Hybridisierungsmuster exakt verglichen werden konnten, auch wenn die Isolate auf verschiedenen Gelen analysiert wurden. Die Methode erhöht die Genauigkeit der Bestimmung genetischer Verwandtschaftsbeziehungen in epidemiologischen Untersuchungen, in denen eine große Anzahl von Stämmen analysiert wird.     

Genetic analysis of the yeast NUD1 endo-exonuclease: a role in the repair of DNA double-strand breaks

The deoxyribonucleases (DNases) have been shown genetically to be important in the vital processes of DNA repair and recombination. The NUD1 gene, which codes for an endo-exonuclease of Saccharomyces cerevisiae, was analyzed for its role in the DNA double-strand break (DSB) repair processes. While the nud1 strain is only slightly sensitive to ionizing radiation, expression of the HO-endonuclease to introduce a DSB at the MAT locus in that strain results in cell death. Cell survival is inversely proportional to the duration of HO-endonuclease expression. Analysis of the surviving colonies from the nud1 strain indicated that many of the survivors are sterile and that the proportion of these sterile survivors increases with the time of HO-endonuclease expression. On the other hand, the surviving colonies from the isogenic NUD1 strain are mating-proficient. Interestingly, double mutants of nud1 rad52 are more resistant to ionizing irradiation than the rad52 strain and have a cell-survival fraction of 32% for rad52-1 nud1 and 9% for rad52::URA3 nud1 following prolonged HO-endonuclease expression, indicating that nud1 has a suppressor effect on the DSB-induced lethality in rad52. Polymerase chain reaction analysis showed that many of the nud1 survivors contained small alterations within the MAT locus, suggesting that the survivors arose through the process of non-homologous end-joining. These results suggest that the endo-exonuclease acts at a DSB to promote DNA repair via the homologous recombination pathway. Received: 20 July / 20 September 1998