Hemophilia A: genetic prediction and linkage studies in all available families in Finland

RFLP studies were done in 82 (75%) of all known hemophilia A families in the Finnish population (approximately 5 million). Two intragenic RFLPs (Bc1I/F8A, XbaI/p482.6) and two extragenic markers (TaqI/St14, Bg1II/DX13) were used. Among 263 females at risk, carriership could be evaluated with an intragenic marker in 47% and with an extragenic marker in 26%. In 27% of the females, carriership could be neither excluded nor confirmed; 68% of these females were relatives of an isolated patient. Eight recombinations between the factor VIII gene (F8C) and DXS52 (lod 25.02 at theta max 0.06), eight recombinations between F8C and DXS15 (lod 21.91 at theta max 0.05), and two recombinations between DXS52 and DXS15 (lod 33.56 at theta max 0.01) were found. Using multipoint linkage analysis, the most likely order of loci supported by the data was: F8C-DXS15-DXS52-DXS134. RFLP segregation analysis provides a highly useful method of carrier detection and prenatal diagnosis of hemophilia A, but its limitations must be carefully taken into account.     

Release of vesicular noradrenaline in the rat tail artery induced by cocaine

Summary The effects of cocaine on overflows of endogenous noradrenaline and DOPEG from isolated rat tail arteries were examined. 1. Both overflows increased progressively with increasing concentration of cocaine, while the (NA overflow)/(DOPEG overflow) ratio first increased and then decreased. The changes in the overflows induced by cocaine (0.1 mmol/l) appeared reversible. 2. Exposure of the tissue for 30 min to cocaine, 1 mmol/l, resulted in a significant decrease in the proportion of storage vesicles containing electron-dense cores. 3. The changes in overflows of noradrenaline and DOPEG induced by cocaine (0.1 mmol/l) were unaffected by the presence of desipramine (0.1 mol/l) or removal of extracellular Ca²⁺. The effect of cocaine on the overflow of noradrenaline was potentiated by prior inhibition of MAO with clorgyline. 4. Exposure of segments to a Ca²⁺-free, high K, low Na incubation medium was accompanied by increased overflow of noradrenaline. Cocaine (0.1 mmol/l) reduced the overflow of noradrenaline to about a half, and substantially increased the overflow of DOPEG. 5. The increase in the overflow of DOPEG from segments bathed in HEPES-buffered solutions, the pH of which ranged from 6.80 to 7.38, was approximately proportional to the calculated concentration of unprotonated (uncharged) cocaine. 6. Quantitatively similar changes in the overflows were observed when norcocaine was substituted for cocaine. Ecgonine methyl ester was much less potent than cocaine, and O-benzoyl ecgonine was ineffective. 7. The small increases in the overflow of noradrenaline observed at relatively low concentration (<30 mol/l) of cocaine can be attributed primarily to inhibition of reuptake of the released transmitter by the cocaine- and desipramine-sensitive amine carrier. The overflows of NA and DOPEG in the presence of higher concentrations of the alkaloid exhibit features compatible with the following hypothesis: (A) Cocaine is translocated across the axonal membrane mainly in the form of the unprotonated species, a large fraction of which is reprotonated upon the entry into the axon. (B) Cocaine releases noradrenaline from storage vesicles into the extravesicular space, where the bulk of the amine is converted to DOPEG. (C) Efflux of the remaining noradrenaline from the axon is not mediated by the Na⁺-dependent, cocaine- and desipramine-sensitive neuronal amine carrier. It seems to represent uncoupled efflux of the protonated form of noradrenaline.Abbreviations DOPEG 3,4-dihydroxyphenylethylene glycol - DOMA 3,4-dihydroxymandelic acid - HEPES N-(2-hydroxyethyl)piperazine-N-ethanesulfonic acid - MAO monoamine oxidase - MOPEG 3-methoxy-4-hydroxyphenylethylene glycol - NA (–)noradrenaline - pH_j pH in the extravesicular space of the axon - pH_o pH of the bathing solution - pK_a negative logarithm of the dissociation constant This study was supported by the British Columbia Heart Foundation Send of fprint requests to V. Palaty at the above address     

中国汉族雄激素过多症女性21-羟化酶缺陷症携带者基因检测

目的　初步了解中国汉族女性雄激素过多症患者中2 1-羟化酶缺陷症(2 1- hydroxylasedeficiency,2 1- OHD)携带者发生率,探讨促肾上腺皮质激素(adrenocorticotropic hormone,ACTH)兴奋试验结果与基因突变检测结果的相关性。方法　82例汉族女性雄激素过多症患者及14名健康女性进行ACTH兴奋试验,并应用PCR扩增产生限制性酶切位点方法检测已知的9个2 1- OHD常见突变位点。结果　雄激素过多组(n=82 ) F0 显著高于正常对照组(P<0 .0 1) ;17- OHP0 及17- OHP6 0 也显著高于对照组(P<0 .0 1) ,而F6 0 差异没有统计学意义(P>0 .0 5 )。比较17- OHP净增值及17- OHP净增值/ F净增值,雄激素过多组也均显著高于正常对照组(P<0 .0 1)。正常对照组未检测出细胞色素P4 5 0 (cytochrome P4 5 02 1,CYP2 1)基因突变。发现雄激素过多组4例CYP2 1基因突变携带者(4/ 82 ,4 .9% ) ,分别携带V2 81L(2例) ,i2 g及Q318X(各1例) ,携带者的ACTH兴奋试验结果与正常对照及未检出突变的雄激素过多症患者的结果存在一定的交叉。结论　82例汉族雄激素过多症女性中2 1- OHD携带者为4例,占4 .9%。ACTH兴奋试验不能用以发现携带者,应进行基因检测确定。     

C57BL/6小鼠胆结石形成中固醇载体蛋白2的mRNA水平和胆固醇饱和指数增高

目的观察C57BL/6鼠胆囊结石形成过程中肝固醇载体蛋白2(SCP2)mRNA水平及胆囊胆汁中胆固醇饱和指数的变化。方法C57BL/6鼠20只,分为结石组和对照组。对照组喂普通饲料,结石组采用1%的胆固醇饮食4周;RT-PCR方法检测肝SCP2 mRNA水平的变化;全自动生化仪检测胆脂,并计算胆固醇饱和指数。结果胆囊结石组肝SCP2 mRNA水平显著升高,胆汁胆固醇饱和指数亦显著增加。结论肝SCP2的表达及胆汁CSI的增高呈正相关。     

骨内植入式药物缓释系统载体材料研究现状及进展

植入式药物缓释系统在治疗骨科感染、肿瘤等方面具有良好的作用。随着组织工程学的进展,研制了不同的材料作为骨内植入式药物缓释系统的载体,拟对骨内植入式药物缓释系统载体材料研究现况及进展进行综述。     

Mitochondrial aspartate glutamate carrier (citrin) deficiency as the cause of adult-onset type II citrullinemia (CTLN2) and idiopathic neonatal hepatitis (NICCD)

 By using homozygosity mapping and positional cloning, we have shown that adult-onset type II citrullinemia (CTLN2) is caused by mutations of the SLC25A13 gene, which is localized on chromosome 7q21.3 and encodes a mitochondrial solute carrier protein named citrin. So far, we have reported nine mutations, most of which cause loss of citrin, and we have established several methods for DNA diagnosis. These methods have shown that more than 90% of the patients diagnosed as suffering from CTLN2 by enzymatic analysis carry SLC25A13 mutations in both alleles, indicating that CTLN2 is caused by citrin deficiency. Furthermore, by using the same DNA diagnosis methods, we discovered that 70 neonates or infants suffering from a particular type of neonatal hepatitis carry the same SLC25A13 mutations. Since the symptoms of the neonates are different from those of the more severe CTLN2 and usually ameliorate without special treatment, we designated the neonatal disease neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD). We conclude that citrin deficiency causes NICCD in neonates and CTLN2 in adults through the additional effects of genetic or environmental modifiers. Since the function of citrin, together with that of an isoform, aralar, was found to be as a mitochondrial aspartate glutamate carrier, the various symptoms of NICCD and CTLN2 may be understood as caused by defective aspartate export from the mitochondria to the cytosol and defects in the malate aspartate shuttle. It is, however, still difficult to understand the cause of the hepatic deficiency of argininosuccinate synthetase protein in CTLN2. Received: March 20, 2002 / Accepted: March 28, 2002     

HBV重组抗原表位抗原性的研究

目的 在外源抗原表位表达载体系统中构建并表达HBV抗原表位,并对其抗原性进行研究.方法 人工合成编码HBV "a"抗原决定簇表位中24个氨基酸(S124-147)的寡核苷酸序列,克隆入外源抗原表位表达载体系统FHV-RNA2-I3位点,构建重组质粒,在原核pET系统(BL21细胞)中表达.以表达产物为包被抗原对其抗原性进行研究.结果 嵌和蛋白与抗-HBs血清可发生特异性结合反应.结论 在外源抗原表位表达系统中表达的HBV抗原表位具有良好的抗原性.     

Polyclonal antibody responses against Listeria monocytogenes 4b surface proteins in asymptomatic human carriers

Listeria monocytogenes 4b surface protein extract was used in an immunoblot assay to analyze the antibody profile in sera from 40 healthy urban workers (U group), 40 healthy slaughterhouse workers (W group) and four healthy carriers with positive L. monocytogenes 4b feces culture (positive controls). In addition, pooled rabbit sera, before and after immunization with L. monocytogenes 4b whole‐cell suspension, were analyzed against L. monocytogenes 4b surface protein extract in order to determine the specific L. monocytogenes 4b antibody pattern. The degree of similarity (S) between such a pattern and each of those obtained with serum samples from the three subject groups was assessed. For U and W group sera, mean S values were 24.3 ± 13.5 and 32.8 ± 14.3, respectively. An S value greater than 65, corresponding to mean S_U value ± 3 standard deviation, was considered as an indicator of a healthy carrier. Thus, the estimated healthy carrier percentages found in U and W groups were 2.5 and 5%, respectively. The proposed immunoblot assay may prove a useful tool for epidemiological surveys to determine whether a healthy person is a L. monocytogenes 4b carrier.     

Patient and parental attitudes toward genetic screening and its implications at an adult cystic fibrosis centre

General population screening for cystic fibrosis carrier status in the United Kingdom would detect 72% of at-risk couples. Proper counselling would allow these couples to make informed reproductive choices, including the possibility of prenatal diagnosis and the termination of an affected pregnancy. However, children with cystic fibrosis born in this decade, given optimum treatment, now have an average life expectancy of 40 years, and there is no unanimity of opinion on how, where, when, or even if, screening should be offered. The purpose of this questionnaire-based study was to examine the attitudes of an adult clinic population who have grown up with cystic fibrosis, and of their parents, towards genetic screening programmes and the controversies and ethical dilemmas surrounding such programmes in cystic fibrosis. Both patients and parents supported prenatal screening (88% and 90%) and the option of terminating an affected pregnancy (68% and 84%). Only 22% of patients and 10% of parents felt that screening should be limited to families with a history of cystic fibrosis, and 19% and 6%, respectively, that prenatal diagnosis should be restricted to those with a previous child with cystic fibrosis. Despite the negative aspects of any screening programme and the acknowledged ethical problems peculiar to cystic fibrosis, the conclusion of our patients and parents who have lived intimately with the illness is that there should be the option of utilising information available from genetic screening for cystic fibrosis to guide reproductive choices. Pilot programmes to define the optimum management of such screening should continue.