cDNA cloning of a human homologue of the Caenorhabditis elegans cell fate-determining gene mab-21: expression, chromosomal localization and analysis of a highly polymorphic (CAG)n trinucleotide repeat

The two most consistent features of the diseases caused by trinucleotide repeat expansion-neuropsychiatric symptoms and the phenomenon of genetic anticipation-may be present in forms of dementia, hereditary ataxia, Parkinsonism, bipolar affective disorder, schizophrenia and autism. To identify candidate genes for these disorders, we have screened human brain cDNA libraries for the presence of gene fragments containing polymorphic trinucleotide repeats. Here we report the cDNA cloning of CAGR1, originally detected in a retinal cDNA library. The 2743 bp cDNA contains a 1077 bp open reading frame encoding 359 amino acids. This amino acid sequence is homologous (56% amino acid identify and 81% amino acid conservation) to the Caenorhabditis elegans cell fate-determining protein mab-21. CAGR1 is expressed in several human tissues, most prominently in the cerebellum, as a message of approximately 3.0 kb. The gene was mapped to 13q13, just telomeric to D13S220. A 5'-untranslated CAG trinucleotide repeat is highly polymorphic, with repeat length ranging from six to 31 triplets and a heterozygosity of 87-88% in 684 chromosomes from several human populations. One allele from an individual with an atypical movement disorder and bipolar affective disorder type II contains 46 triplets, 15 triplets longer than any other allele detected. Though insufficient data are available to link the long repeat to this clinical phenotype, an expansion mutation of the CAGR1 repeat can be considered a candidate for the etiology of disorders with anticipation or developmental abnormalities, and particularly any such disorders linked to chromosome 13.      

量子点技术在生物成像中的应用进展

目的：介绍量子点材料的特点及其在生物成像中的应用,并对其前景进行展望. 资料来源：应用计算机检索PubMed 1998-01/2007-04关于量子点生物成像文章.检索词“quantum dots,biological imaging,bioconjugates,fluorescence imaging”限定文章的语言种类为“English”. 资料选择：对资料进行初审,纳入标准：①量子点的特点及表面修饰.②量子点在不同的生物组织细胞中的成像应用.排除标准：重复性研究. 资料提炼：共收集到符合上述要求的文献31篇,关于量子点的特点及表面修饰的14篇,关于量子点在不同的生物组织细胞中的成像应用17篇. 资料综合：量子点（quantum dots,QDs）是一种新型纳米荧光材料,现有技术能将量子点与生物分子结合在一起作为一种高亮度而稳定的荧光探针用于生物成像.作为一种新型的荧光纳米材料量子点,在多种类型的生物成像研究中较传统的有机荧光素和荧光蛋白而言具有更加优越的特性,使研究者能够以一种全新的方法对单个细胞、组织、甚至活动物的基因、蛋白质和药物靶点进行研究,为疾病机制的阐明和临床诊疗提供有力帮助. 结论：量子点荧光标记材料具有信号稳定、标记简便、检测灵敏的优点,在生物成像中具有良好的应用前景.     

Th activation of maternal and cord blood

Th activation of red cells is characterized by agglutination with the peanut lectin from Arachis hypogaea and is diminished by treatment with proteolytic enzymes. The first cases of Th activation were associated with bacterial infections. More recently, a high incidence of Th activation in congenital hypoplastic anemia has been reported, along with the finding that 13.5 percent of cord bloods are Th activated. The incidence of Th reactivity in newborn infants was confirmed by studying 200 paired samples of maternal and cord blood. Twenty-two (11%) of the cord samples and 13 (6.5%) of the maternal samples were Th activated. In 6 paired samples (6/22), both the mother and child had Th activation, a finding that demonstrates a high degree of concordance. Additionally, 3 (6%) of 50 pregnant women were Th positive. These findings indicate that Th activation is another of the red cell antigen alterations related to pregnancy.     

用电化学检测器的高效液相色谱法测定血清及尿中速尿的含量

本文报告了用电化学检测器的高效液相色谱法测定血清及尿中速尿含量的方法。样品予处理方法:血清用乙腈除蛋白,尿用蒸馏水稀释50倍。采用作者合成的FD-Val-OH作为内标物。色谱条件为:反相柱,以含35%乙醇的5mmol/L四丁基铵水溶液为流动相(pH7.50),流速1.0ml/min;用电化学检测器,检测电压0.90V:速尿及内标物的保留时间分别为10和15min。通过计算速尿对内标物的峰高比求得速尿含量。血清及尿中的最低检测浓度分别为16和9ng/ml。标准曲线在0.25～5ng/μl(血清)、0.5～10ng/μl(尿)的浓度范围内呈线性关系。血清及尿中回收率分别为100.5%和100.6%。变异系数在4.6%以下。     

High rates of early HBeAg seroconversion and relapse in Indian patients of chronic hepatitis B treated with Lamivudine: results of an open labeled trial

Background  

The use of Lamivudine in chronic hepatitis B (CHB) is well known, however the reported rate of HBeAg sero-conversion and its durability post-treatment have varied considerably. We undertook the present study to study the effect of Lamivudine on HBeAg loss and seroconversion rates in Indian patients of CHB in relation to frequency, predictors and durability.     

Variation in blood sample collection for determination of hemodialysis adequacy. Council on Renal Nutrition National Research Question Collaborative Study Group

Inadequate dialysis has been associated with high morbidity and mortality in end-stage renal disease (ESRD) patients receiving maintenance hemodialysis. The accurate estimation of dialysis adequacy, measured either as a calculated urea kinetics (Kt/V) or a simple urea reduction ratio (URR) is dependent on the proper collection of blood samples for predialysis and postdialysis blood urea nitrogen (BUN) determination. Because no established protocol exists for blood sampling, we surveyed the study cohort of dialysis centers participating in the National Kidney Foundation Council on Renal Nutrition National Research Question Collaborative Study to determine the comparability of BUN data that were collected to calculate URR to determine adequacy of dialysis. Surveys were completed by 100% of the 202 units participating: 195 in the United States (from 43 states) and seven from Canada, treating approximately 15,000 hemodialysis patients in total. The distribution of the sample by the type of facility mirrored that of 1996 United States Renal Data System (USRDS) Annual Report facilities data. Results showed a 5.0% error in predialysis blood draw and an 8.4% to 41.6% error in the postdialysis counterpart. There was a large variability in the observed postdialysis methods in general. Dilution of predialysis sample with either heparin or saline will falsely underestimate Kt/V and URR. The presence of access-derived, recirculated blood in the postdialysis sample will falsely overestimate Kt/V and URR. Excessive delay in drawing postdialysis sample will reduce Kt/V and URR because of urea rebound. Adoption by all dialysis providers of a uniform blood sample draw procedure will result in a consistency necessary to allow reliable and valid comparison of adequacy of dialysis parameters within and between ESRD patients, units, and clinical trials.     

DERMAL NEUROVASCULAR DYSFUNCTION IN TYPE 2 DIABETES

The present article summarizes recent observations obtained in our laboratory which clearly indicate that sex steroids exert relevant effects on the peripheral nervous system. In particular, the following important points have emerged: (1) Steroids exert stimulatory actions on the synthesis of the proteins proper of the peripheral myelin (e.g., glycoprotein Po and peripheral myelin protein 22) in vivo and on the Schwann cells in culture; (2) in many cases the actions of hormonal steroids are not due to their native molecular forms but rather to their metabolites (e.g., dihydroprogesterone and tetrahydroprogesterone in the case of progesterone; dihydrotestosterone and 5 alpha-androstane-3 alpha,17 beta -diol in the case of testosterone); (3) the mechanism of action of the various steroidal molecules may involve both classical (progesterone and androgen receptors) and nonclassical steroid receptors (GABA, receptor); and finally, (4) the stimulatory action of steroid hormones on the proteins of the peripheral myelin might have clinical significance in cases in which the rebuilding of myelin is needed (e.g., aging, peripheral injury, demyelinating diseases, and diabetic neuropathy).