The molecular basis of beta thalassaemia in Punjabi and Maharashtran Indians includes a multilocus aetiology involving triplicated alpha-globin loci

We have analysed 201 beta-thalassaemia (beta-thal) genes from natives of the Punjab (156) and Maharashtra states of India and found the causative mutation in 200 of them. The most common beta-globin gene mutations differed significantly between these two groups and between these groups and Indian immigrants in the U.S.A. and the U.K. In the Punjabi Indians the IVS-1, nt 1 (G-T) mutation accounted for nearly one-quarter of beta-thal genes, whereas it was 5% or less in the other groups. Likewise, the cap + 1 mutation was much more prevalent in the Punjabis, whereas the nonsense codon 15 allele had a higher frequency in the Maharashtrans of the Bombay region. The common IVS-1, nt5 allele had a frequency of 60% of beta-thal genes in the Maharastrans, 35% in North American immigrants, and only 23% in the Punjabis. Two-thirds of all beta-thal genes in Punjab were found in the merchant caste (Khatri-Arora), whereas the menial caste (Shudra) was highly represented among those with beta-thal genes in Maharashtra. Two novel beta-globin alleles were each found once; a frameshift codon 55 (+A) in Maharashtrans and a frameshift codons 47-48 (+ATCT) in Punjabis. Of three Punjabi patients with beta-thal intermedia in whom only a single severe beta-globin gene mutation was found, two had six alpha-globin genes (homozygosity for a triplicated alpha-globin locus) instead of the normal alpha-globin gene number of four. Thus, these two individuals had a multilocus aetiology of beta-thal and their parents have the unusual recurrence risk of 1 in 8 for conceiving a third with beta-thal intermedia. Since 15% of 126 alpha-globin clusters studies in Punjabis contained either single (10%) or triplicated (5%) alpha-globin genes, the alpha-globin gene number is a frequent modifier of the phenotype of beta-thal in this ethnic group.     

新制定的国家标准《爆炸性气体环境用电气设备 电阻式伴热器 第1部分: 通用和试验要求》内容简介

主要对新制定的国家标准《爆炸性气体环境用电气设备电阻式伴热器第1部分：通用和试验要求》制定情况和标准中的主要技术内容进行了介绍。     

阳极产生的Sn^2＋引发聚合（N,N,N—三甲基—N—2—甲基丙烯酰氧乙基）氯化 …

研究了使用新的合成技术和引发剂Ｓｎ＾２＋进行ＤＭＡＥＭ－ＭＣ阳离子聚合过程,Ｓｎ＾２＋由牺牲阳极产生。在只有Ｓｎ材作电极的间歇反应器中配制聚合物,获得了电解法制备聚合物转化率和平均分子质量的影响因素。一方面,这些结果表明搅拌速度、初始ｐＨ值、电流密度和电极构成对转化率和聚合物分子质量都有重要影响;另一方面,温度和单体浓度在电化聚合过程中的影响虽是次要的,然而这两种因素在传统化学方法中影响最大。理想     

Three-dimensional structure of an evolutionarily conserved N-terminal domain of syntaxin 1A

Syntaxin 1A plays a central role in neurotransmitter release through multiple protein-protein interactions. We have used NMR spectroscopy to identify an autonomously folded N-terminal domain in syntaxin 1A and to elucidate its three-dimensional structure. This 120-residue N-terminal domain is conserved in plasma membrane syntaxins but not in other syntaxins, indicating a specific role in exocytosis. The domain contains three long alpha helices that form an up-and-down bundle with a left-handed twist. A striking residue conservation is observed throughout a long groove that is likely to provide a specific surface for protein-protein interactions. A highly acidic region binds to the C2A domain of synaptotagmin I in a Ca2+-dependent interaction that may serve as an electrostatic switch in neurotransmitter release.     

Human immunodeficiency virus type 1 protease genotypes and in vitro protease inhibitor susceptibilities of isolates from individuals who were switched to other protease inhibitors after long-term saquinavir treatment

An understanding of the mechanisms of virologic cross-resistance between human immunodeficiency virus type 1 protease inhibitors is important for the establishment of effective treatment strategies for patients who no longer respond to their initial protease inhibitor. Protease gene sequencing results from patients treated with saquinavir showed significant increases in the frequency of the G48V protease mutation in patients receiving higher doses of the drug. In addition, all six patients who developed the G48V mutation during saquinavir therapy developed the V82A mutation either on continued saquinavir or after a switch to nelfinavir or indinavir. In vitro susceptibility assays showed that all 13 isolates with reduced susceptibilities to two or more protease inhibitors had either the G48V or L90M mutation, along with an average of six other protease mutations. Reduced susceptibility to nelfinavir was found in 14 isolates, but only 1 possessed the D30N mutation. These results suggest that mutations selected in vivo by initial saquinavir therapy may provide more cross-resistance to the other protease inhibitors than has been previously reported.     

Environmental investigation of a legionellosis outbreak in western Sydney: the role of molecular profiling

Colitis following colonoscopy is an acute, self-limited condition characterized by tenesmus and bloody diarrhea appearing within 48 hours of colonoscopy or sigmoidoscopy. Glutaraldehyde used for disinfection of the endoscopes is considered to be the main etiological agent. Three cases of severe acute self-limited colitis are described in this report. All three were observed within one week, and showed the typical anamnestic, clinical, endoscopic, histological, and radiological features of glutaraldehyde-induced colitis. The main characteristics in these cases were the time relationship with colonoscopy and the severity of the clinical presentation, with symptoms of systemic reaction and intense and diffuse edema of the colonic mucosa. The clinical and morphological features may mimic those of colonic ischemia. All three patients recovered completely within a few days, one spontaneously and two after treatment with steroids, antibiotics, and mesalazine. Acute colitis following colonoscopy should be regarded as one of the complications related to colonoscopy, and it should be taken into account in the differential diagnosis of acute colitis.     

Stabilization of an inserted tricalcium phosphate spacer enhances the healing of a segmental tibial defect in sheep

The effect of inserting a tricalcium phosphate (TCP) spacer stabilized by a rigid or non-rigid fixation technique on the healing of segmental tibial defects of critical size was established. The osteotomized tibiae, 11 with and 8 without TCP spacers, were fixed by an external circular device in 11 mature sheep and by plates in 8 mature sheep, respectively. Healing was evaluated roentgenographically 16 weeks after the operation. Compared with the defects without TCP spacers, enhanced stability and healing were observed in the defects with TCP spacers under an identical external fixation. Furthermore, a significantly higher incidence of healing was obtained with plate fixation than with external device fixation in the TCP-implanted defects (P < 0.04). An abundant bridging callus was roentgenograpically demonstrated in most of the healed defects, but none in the unhealed defects. The TCP spacer with its mechanical integrity enhances the stability of external fixation, and the stable immobilization provided by rigid fixation is essential for osteoconduction of an inserted TCP spacer in the healing of segmental diaphyseal defects in sheep.     

Bridging student health risks and academic achievement through comprehensive school health programs

In the National Action Plan for Comprehensive School Health Education, representatives for over 40 health, education, and social service organizations viewed education and health as independent systems. Participation concluded that healthy children learn better, and they cautioned that no curriculum can compensate for deficiencies in student health status. While literature confirms the complexity of health issues confronting today's students, schools face enormous pressure to improve academic skills. Local school leaders and stakeholders often remain unconvinced that improving student health represents a means to achieving improved academic outcomes. A rich body of literature confirms a direct link between student health risk behavior and education outcomes, education behavior, and student attitudes about education. This article summarizes relevant information concerning the health risk behavioral categories of intentional injuries; tobacco; alcohol, and other drugs; dietary, physical activity, and sexual risk behaviors.