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51.
Hsieh M Chiu MH Lin YH Lin CH Lu TM Li SY Li C 《Proceedings of the National Science Council, Republic of China. Part B, Life sciences》2000,24(2):76-80
Dentatorubral and pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder with expansion of trinucleotide CAG repeats in the coding region of the gene. Expansion of the repeat tract beyond the normal range produces gene products with extended polyglutamine tracts. In this study, we analyzed the distribution of the CAG repeats in the DRPLA alleles in a normal Taiwanese population. We observed 15 different alleles and found that the range of the CAG repeat number was from 7-21. The most frequent allele contained 15 CAG repeats that represented 20% of the total analyzed alleles, followed by the 17 repeats (15.8%). The heterozygosity rate of this locus was 88%. Twelve parents-to-children transmissions of the DRPLA alleles in a Machado-Joseph disease family appeared to be normal without any alteration of the CAG repeat numbers. Phenotypes of DRPLA overlapped those of autosomal dominant cerebellar ataxia (ADCA). In order to identify DRPLA patients in Taiwan, we screened six autosomal dominant cerebellar ataxia patients without expansion in known spinocerebellar ataxia genes. All six patients had the repeat numbers within the normal range; thus, the possibility of DRPLA could be excluded. 相似文献
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Bacteriophage lambda gt11 has been used quite extensively for producing cDNA libraries. The cDNA inserts are usually subcloned into a plasmid vector for large scale production and analysis. However, isolating the recombinant DNA of interest from the phage clones can be a tedious task. Since the E. coli strain Y1088 used for lambda gt11 phage infection carries a pBR322-derived plasmid endogenously, we reasoned that this endogenous plasmid could be used directly for cloning the cDNA phage insert. In this report, we describe a method in which cDNA inserts from lambda gt11 phage were cloned directly into the pBR322 plasmid vector, bypassing the time-consuming procedures of preparing plasmid DNA as a subcloning vector. This method is likely to be extended to the cloning of DNA inserts derived from other phage lambda vectors when bacteria containing endogenous pBR322 are used as host cells. 相似文献
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Chiu LZ Fry AC Weiss LW Schilling BK Brown LE Smith SL 《Journal of strength and conditioning research / National Strength & Conditioning Association》2003,17(4):671-677
To determine if training status directly impacted the response to postactivation potentiation, athletes in sports requiring explosive strength (ATH; n = 7) were compared to recreationally trained (RT; n = 17) individuals. Over the course of 4 sessions, subjects performed rebound and concentric-only jump squats with 30%, 50%, and 70% 1 RM loads. Jump squats were performed 5 minutes and 18.5 minutes following control or heavy load warm-ups. Heavy load warm-up consisted of 5 sets of 1 repetition at 90% 1 RM back squat. Jump squat performance was assessed with a force platform and position transducer. Heavy load warm-up did not have an effect on the subjects as a single sample. However, when percent potentiation was compared between ATH and RT groups, force and power parameters were significantly greater for ATH (p < 0.05). Postactivation potentiation may be a viable method of acutely enhancing explosive strength performance in athletic but not recreationally trained individuals. Reference Data: Chiu, L.Z.F., A.C. Fry, L.W. Weiss, B.K. Schilling, L.E. Brown, and S.L. Smith. Postactivation potentiation response in athletic and recreationally trained individuals. 相似文献
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The formation of human islet amyloid polypeptide (hIAPP) is implicated in the loss of pancreatic β-cells in type II diabetes. Rat amylin, which differs from human amylin at six residues, does not lead to formation of amyloid fibrils. Pramlintide is a synthetic analog of human amylin that shares three proline substitutions with rat amylin. Pramlintide has a much smaller propensity to form amyloid aggregates and has been widely prescribed in amylin replacement treatment. It is known that the three prolines attenuate β-sheet formation. However, the detailed effects of these proline substitutions on full-length hIAPP remain poorly understood. In this work, we use molecular simulations and bias-exchange metadynamics to investigate the effect of proline substitutions on the conformation of the hIAPP monomer. Our results demonstrate that hIAPP can adopt various β-sheet conformations, some of which have been reported in experiments. The proline substitutions perturb the formation of long β-sheets and reduce their stability. More importantly, we find that all three proline substitutions of pramlintide are required to inhibit β conformations and stabilize the α-helical conformation. Fewer substitutions do not have a significant inhibiting effect. 相似文献
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