Molecular epidemiological investigation of abnormal hemoglobin in Shaokwan region, southern China.

OBJECTIVES: Shaokwan is one of the inhabitant regions of Hakka population in Guangdong province of southern China. Previous survey has reported that a higher prevalence of abnormal hemoglobin (Hb) in this region. However, large-scale survey on the molecular characteristics of abnormal hemoglobin in this south-north junctional region has not been reported.In this study, we aim to investigate the molecular characteristics of abnormal hemoglobin in this area. METHODS: Blood samples from medical check-up center in one local hospital were selected for abnormal hemoglobin screening. Hemoglobin electrophoresis and routine blood tests were performed. Hemoglobin variants were further analyzed by PCR and DNA sequencing. RESULTS: Among the 9731 study subjects, 45 cases of hemoglobin variants were found by hemoglobin electrophoresis, which gave an incidence of 0.46% (45/9731) in Shaokwan region. 8 kinds of hemoglobin variants were identified by gene sequencing. Hb Q-Thailand (16/45) was the most common hemoglobin variants, followed by HbE (7/45), Hb NewYork (6/45) and Hb G-Chinese (6/45). DISCUSSION AND CONCLUSION: Hemoglobin variants had obviously genetic polymorphisms in Chinese. Our study of hemoglobin disorders in this special Hakka Chinese population will contribute considerably to our understanding of the historical, emigrational, and genetic relationships among different ethnic group in this region.

Human serum albumin variants in China: a molecular epidemiological investigation and literature review.

BACKGROUND: Bisalbuminemia is a hereditary and/or acquired abnormality characterized by a double albumin (ALB) band on serum protein electrophoresis. However, there have been no epidemiological investigations of ALB variants in Chinese populations. METHODS: This retrospective study examined 71,963 unrelated subjects from five provinces in southern China. ALB variants were screened by cellulose acetate electrophoresis at pH 8.6 and ALB mutations were confirmed by polymerase chain reaction-DNA sequencing. RESULTS: The average incidence of inherited bisalbuminemia in the southern Chinese population was 0.0264% (19/71,963). Thirteen cases showed slow and six showed fast genetic variants on cellulose acetate electrophoresis. Four kinds of ALB variants were identified: proalbumin Lille (p.Arg23His), ALB Castel di Sangro (p.Lys560Glu), ALB Fukuoka-1 (p.Asp587Asn), and a novel ALB Wuxi (p.Lys562Glu). The gene frequency of ALB variants in the Wuxi region (0.126%, 13/10,297) was significantly higher than in other regions in southern China, and 90.9% (10/11) of cases of proalbumin Lille were also found in the Wuxi region. CONCLUSIONS: This study provides the first report of the detailed prevalence and molecular characterization of ALB variants in southern China. Compared with other areas of China, Wuxi had a different pattern of ALB variants and a high prevalence of proalbumin Lille.

[Selecting and affinity analysis of DNA aptamers to MPT64 protein from Mycobacterium tuberculosis].

OBJECTIVE: To obtain DNA oligonucleotide aptamers which can specifically bind to MPT64 protein from Mycobacterium tuberculosis by SELEX technology. METHODS: An in vitro synthesized 78 per random DNA library was subjected to 12 rounds of selection by SELEX (Systematic evolution of ligands by exponential enrichment) method against MPT64 protein. Binding of the aptamers to the protein was examined by biotin-streptavidin-horseradish peroxidase system. DNAMAN package was employed to analyze the sequences and the second structures of the aptamers. Moreover, target protein was bound to one aptamer and another aptamer modified with biotin together forming a sandwich-like complex, which was captured in microwell, to be tested in negative group including BCG and reference strains from nontuberculous mycobacteria, and positive group including H37Rv, Mycobacterium bovis reference strain, and clinical strains from Mycobacterium tuberculosis. RESULTS: After 12 rounds of selection, high-affinity aptamers to MPT64 was obtained. The OD value at 450 nm of affinity of aptamers to MPT64 protein was from 0. 492 to 1.243, in which 73.3% was over 1.0. Pocket and stem-loops was the basis of aptamers binding to MPT64 protein by the analysis of structures,with several GC pairs among bridges between pocket and stem-loops. The analysis of the sandwich-like complex system based on two aptamers and protein showed that the positive percentage was 87. 9% in the positive group while the negative percentage was 85.7% in the negative group, with positive H37Rv and Mycobacterium bovis, and negative BCG, when the cut-off value for a positive response was 0.61 OD. CONCLUSION: A set of aptamers with considerable binding affinity to MPT64 protein were successfully selected from the initial random DNA library.