Showing papers by "Chinese Center for Disease Control and Prevention published in 1997"

Long-term supplementation with selenate and selenomethionine: Urinary excretion by New Zealand women

Abstract: Thirty-six New Zealand women aged between 18 and 23 years received daily for 32 weeks, 200 micrograms Se as Se-enriched yeast (selenomethionine, SeMet), or brewer's yeast mixed with selenate, or no added Se (placebo) in a double-blind trial. Mean daily Se excretion increased with both supplements; the selenate group excreted more than the SeMet group, 123 v. 66 micrograms/d respectively at week 2, equivalent to 57 v. 27% of the dose. Thereafter Se output increased for the SeMet group reaching a plateau at about 100 micrograms/d at week 16, when plasma Se had also plateaued at 190 ng/ml. The selenate group had reached an earlier plateau of 110 ng Se/ml at week 7. There was a close relationship between 24 h urine and plasma Se for the SeMet group but not for the selenate group. Renal plasma clearances showed two distinctly different responses; the clearance of 0.4 ml/min reached by the SeMet group at week 2 plateaued as plasma Se increased almost 2-fold; whereas for the selenate group the clearance varied between 0.8 and 1.1 ml/min whilst plasma Se remained almost constant at 110 ng/ml. Previous studies, also of 200 micrograms Se/d as Se-rich bread, in New Zealand (NZ) and elsewhere showed similar responses to Se-yeast; the selenite response was intermediate between selenate and Se-yeast (SeMet). The full significance of these studies awaits identification of Se components in plasma, glomerular filtrate and urine; meanwhile renal clearances serve as a pointer to changes in the distribution of Se-containing fractions in the plasma. Trimethylselenonium was detected in basal urines, and was a minor component in urines of supplemented NZ subjects at about 1% of the total Se.

Relationship between dietary nutrients intakes and human prostate cancer

Abstract: In order to study the relationship between dietary nutrients intakes and prostate cancer, 1 : 1 matched case-control study was carried out with 102 patients suffered from histologically confirmed prostate cancer and 102 healthy controls. Total calories and 11 nutrients including protein, lipid and carbohydrates were calculated based on the mean food intakes in the latest 3 days. Analyzed by matched t-test and conditional logistic regression method, the results showed that high intakes of lipid, carbohydrates, and retinol increased the risk of prostate cancer, but vitamin C and vitamin B1 decreased the risk of prostate cancer. The multivariable adjusted ORs were 1.65 (95% confident interval (CI) 1.39-1.96) for lipid, 1.22 (95% CI 1.13-1.31) for carbohydrates, 3.21 (95% CI 2.18-4.75) for retinol, 0.61 (95% CI 0.6-0.80) for vitamin C, and 0.029 (95% CI 0.009-0.09) for vitamin B1. The authors discussed the possible mechanism of dietary nutrients contributing to the risk of prostate cancer.

Epstein-Barr virus in synergy with tumor-promoter-induced malignant transformation of immortalized human epithelial cells

Abstract: It is difficult to study how Epstein-Barr virus (EBV) causes transformation of human epithelial cells. The major difficulty is that cultured human epithelial cells do not express EBV receptor (complement receptor 2, CR2), hence EBV cannot infect such epithelial cells directly. In order to investigate the role of EBV in the transformation of human epithelial cells, pSG-CR2-Hyg carrier was transfected into immortalized human epithelial cells (293 cells) to express EBV receptor. EBV could infect these CR2-positive cells directly, and expressed EBV antigens. EBV-infected epithelial cells grew in piles with multiple cellular layers and lost contact inhibition in vitro. In soft-agar culture containing 12-O-tetradecanoylphorbol 13-acetate (TPA), EBV-infected 293 cells formed more and larger colonies. When EBV-infected 293 cells were transplanted subcutaneously into nude mice, and treated with TPA, poorly differentiated carcinoma was induced. These results suggest that EBV could induce the malignant transformation of immortalized human epithelial cells in synergy with TPA.

Sequence analysis and comparison of 190 K surface antigen gene fragment of a new species of spotted fever group rickettsiae

Abstract: A 533 bp long PCR product amplified from rickettsial strain HL-93 DNA with the primer pair Rr 190.70p and Rr 190.602n, designed from DNA sequence encoding 190 K protein antigen of R. rickettsii, was cloned into plasmid vector PGEM-T and sequenced. The primer-flanking region of the product, an open reading frame, was 491 bp long. The sequence of the product was compared with those of the corresponding regions of DNAs of R. rickettsii (strain R), R. japonica (strain VR 1363) and R. conorii (strain Malish 7) which were reported earlier by other authors. The results showed that 23, 31 and 52 nucleotides in the compared sequence in strain HL-93 differed from those in R. japonica, R. rickettsii and R conorii, respectively. The homologies of strain HL-93 with R. japonica, R. rickettsii and R. conorii were 95.6%, 94% and 90% in nucleotide, and 89%, 87% and 80% in putative amino acid sequences. We consider strain HL-93 as a new member of the spotted fever group (SFG) rickettsiae on the basis of a high degree of homology and genetic divergence in the nucleotide sequence of a part of the 190 K protein gene.

Epidemiological study on human prostate cancer in Wuhan City

Abstract: In America, Canada and many European countries, prostate cancer is the most common cancer and the second leading cause of cancer death in men. In China, the morbidity rate and mortality rate of prostate cancer are unknown. Based on the reports of Wuhan cancer surveillance in 1990-1992, this study researched the epidemiological characterics of prostate cancer. The results showed that morbidity rate and mortality rate in Wuhan city are 1.37 and 0.75 per 100,000 respectively, and the standardized morbidity rate and standardized mortality rate are 1.10 and 0.66 per 100,000 respectively. They also showed that history of urinary diseases (OR = 5.42, 95% confidence interval (CI): 1.56-18.83), children number with more than 3 (OR = 2.43, 95% CI: 1.17-5.02), coitus with more than 3 times per week in youth (OR = 3.38, 95% CI: 1.51-7.58), frequent use of sexual drugs (OR = 4.12, 95% CI: 1.65-10.25) and high body mass index (OR = 2.58; 95% CI: 1.30-5.11) are identified as risk factors of prostate cancer statistically, but physical labor (OR = 0.35, 95% CI: 0.17-0.71) and age of first nocturnal emission after 18 years old (OR = 0.20, 95% CI: 0.08-0.52) are protective factors.