Association of -238G/A polymorphism of tumor necrosis factor-alpha gene promoter region with outcomes of hepatitis B virus infection in Chinese Han population

AIM: To clarify whether -238G/A polymorphism of tumor necrosis factor-a (TNF-a) gene promoter region was associated with outcomes of hepatitis B virus (HBV) infection in Han population of northern China, and to analyze the geneenvironment interaction between -238G/A polymorphism and cigarette smoking or alcohol consumption. METHODS: A case-control study was conducted to analyze the association of TNF-a gene promoter polymorphism with HBV infection outcomes. A total of 207 patients with chronic hepatitis B (HB) and 148 cases of self-limited HBV infection from Ditan Hospital and Shunyi District Hospital in Beijing, respectively were recruited. History of smoking and alcohol drinking was inquired by a questionnaire. The -238G/A polymorphism of TNF-a gene promoter was genotyped by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP). RESULTS: The frequencies of GG and GA genotypes were 98.07% and 1.93% in chronic HB patients and 93.24% and 6.76% in self-limited HBV infection individuals, respectively (X^2=5.30, P=-0.02). The frequency of G allele was significantly higher in patients with chronic HB that in individuals with self-limited HBV infection (99.03% vs 96.62%, X^2=5.20, P=0.02). Only modestly increased risk of onset of chronic HB was found in smokers (OR=1.40, 95% CI： 0.87-2.28, P=0.14) and drinkers (OR=-1.26, 95%CI： 0.78-2.05, P=-0.32). There was a positive interaction between genotype GG and cigarette smoking with an interaction index (Ⅱ) of 2.95, or alcohol consumption with an Ⅱ of 1.64. CONCLUSION: The -238G/A polymorphism of TNF-a gene promoter region is independently associated with different outcomes of HBV infection.

Blocking effects of genistein on cell proliferation and possible mechanism in human gastric carcinoma

AIM: To study the blocking effects of genistein on cell proliferation cycle in human gastric carcinoma cells (SGC-7901) and the possible mechanism.METHODS: MTT assay was applied in the detection of the inhibitory effects of genistein on cell proliferation. Flow cytometry was used to analyze the cell cycle distribution.Immunocytochemical technique and Western blotting were performed to detect the protein expression of cyclin D1,cyclin B1 and p21waf1/cip1.RESULTS: Genistein significantly inhibited the growth and proliferation of human gastric carcinoma cells (SGC-7901).Seven days after treatment with different concentrations of genistein (2.5, 5.0, 10.0, 20.0 μg/mL), the growth inhibitory rates were 11.2%, 28.8%, 55.3%, 84.7%respectively and cell cycles were arrested at the G(2)/Mphase. Genistein decreased cyclin D1 protein expression and enhanced cyclin B1 and p21waf/cip1 protein expression in a concentration-dependent manner.CONCLUSION: The growth and proliferation of SGC-7901 cells can be inhibited by genistein via blocking the cell cycle,with reduced expression of cyclin D1 and enhanced expression of cyclin B1 and p21waf/cip1 protein in the concentration range of 0-20 μg/mL.

Polymorphisms of Renin-angiotensin System in Essential Hypertension in Chinese Tibetans

Objective To evaluate the potential implications of the genetic variability of angiotensin converting enzyme, angiotensinogen and angiotensin II type 1 receptor gene for essential hypertension in Tibetan. Methods A case-control study was conducted in 173 hypertensive individuals and 193 individuals with normal blood pressure. Multiple logistic regression analyses were used to estimate the risks of developing hypertension for different genotypes, and haplotype analyses of the angiotensinogen gene were used to determine the association between two-locus angiotensinogen gene polymorphisms and hypertension. Results As to the risk to high blood pressure and high systolic pressure, women with MM genotype were 7.7 (95% CI: 1.3-20.5) and 8.7 (95% CI: 1.8-20.1) times higher than those with TT genotype after adjustment for age and body mass index. Haplotype frequencies for M235T and G-6A were significantly different between hypertensive individuals and controls, which indicated an association of angiotensinogen gene haplotypes with hypertension, and a significant association of 235T/-6A haplotype with hypotensive effect. Conclusion Our results suggest that angiotensinogen gene 235MM is a predictor for hypertension development in Tibetan women but not in men, and may exert its hypertensive effect on linkage disequilibrum with a possible function locus of G-6A.

β_2-ADRENERGIC RECEPTOR GENE POLYMORPHISM IN CHINESE NORTHERN ASTHMATICS

To investigate whether the polymorphisms of β2-adrenergic receptor (β2-AR) at position 16, 27, 164 are asso-ciated with asthma in Northern Chinese subjects. Methods Genomic DNA was collected from unrelated Northern Chinese population of Han ethnicity, including 125 un-related asthmatic individuals and 96 healthy controls. β2-AR genes at position 16, 27, 164 were amplified by using restriction fragment length polymorphism (RFLP) and allelic specific polymerase chain reaction methods. All asthmatics had their serum IgE (total and specific) antibody or skin-prick test measured, bronchial reactivity to methacholine (Mch) and bronchial rever-sibility by β2-agonist evaluated. Results (1) The frequency of Gly 16 homozygous was significantly higher in the asthmatic group than that in healthy controls (22.4% vs. 8.3%, P < 0.05), OR was 2.9 with 95% CI 1.26-6.78. The proportion of Gly 16 allele was also higher in asthmatics than that in control (0.46 vs. 0.36, P < 0.05); Gly16 homozygous was not independently associated with asthma pathogenesis (P = 0.21, OR 0.42 with 95% CI 0.11-1.61). (2) Of 51 night attack patients, 18 carrying Gly16 homozygosity, if compared with 10 of 74 nonnocturnal asthmatics carrying this genotype, there was significant difference between these two groups (35.3% vs. 13.5%, P < 0.01). (3) The average dose of PD20-Mch was significantly lower in patients carrying Gln 27 homozygous than those carrying homozygous Glu 27 and Gln/Glu 27 heterozygous (0.2 ± 0.3, 1.6 ± 0.8, and 2.1 ± 3.0 μmol/L,P < 0.05). Conclusion β2-AR gene polymorphisms might confer susceptibility to asthma in Chinese Northern patients. β2-AR gene, coordinated with other candidate loci, plays a role in the development of asthma.

Physical Parameters of a Flare Derived from Multi-line 2D Spectroscopy

Time series of 2D spectra of Hα and CaⅡ λ8542 for a flare of 1999 December 22 are obtained and analyzed with a new fitting technique. The method we proposed can simultaneously yield the four parameters: the line source function, the optical thickness at line center, the line-of sight velocity and the Doppler width. We present the spatial distributions of the physical parameters and their temporal evolutions determined from the 2D spectra. Our results are consistent with the general picture predicted by the flare dynamic models.

A Novel Method for N-terminal Acetylation Prediction

The Net Acet method has been developed to make predictions of N-terminalacetylation sites, but more information of the data set could be utilized to improve the performanceof the model. By employing a new way to extract patterns from sequences and using a samplebalancing mechanism, we obtained a correlation coefficient of 0.85, and a sensitivity of 93% on anindependent mammalian data set.