SummaryThe incidence of breast cancer has been greatly increasing in Taiwan over the past two decades. Since cytochrome P4501A1 (CYP1A1) is involved in the metabolism of environmental carcinogens or oestrogen, we hypothesized that CYP1A1 genetic polymorphism may be a susceptibility factor for breast cancer. This hypothesis was evaluated in this case control study of 150 breast cancer patients and 150 healthy controls among Chinese women. Two CYP1A1 polymorphisms were studied, one containing a new Msp1 site and the other located in axon 7 and resulting in the replacement of an isoleucine (Ile) residue by a valine (Val). After simultaneously considering the known or significant risk factors for breast cancer, including the age of study participants, positive family history of breast cancer, early menarche (≤ 13 years), nulliparity and late first full-term pregnancy (≥ 30 years), hormone replacement therapy and smoking, the CYP1A1 Msp1 polymorphism was found to be a significant factor in determining the risk of breast cancer. The homozygous variant was the most susceptible genotype with an adjusted odds ratio of 1.98 (95% confidence interval (CI) = 1.01-3.99) compared with the non-homozygous variants (the homozygous wild-type and the heterozygous variant). In contrast, the CYP1A1 Ile/Val polymorphism was not significantly associated with breast cancer development (adjusted OR = 1.07, 95% CI = 0.64-1.78). Interestingly, the Msp1 polymorphism was especially significant in postmenopausal women, but not in premenopausal women. Further stratification analysis in postmenopausal women who were non-smokers and with no history of hormone replacement therapy showed the cancer risk due to the Msp1 variant to be more significant in women with early menarche. We conclude that CYP1A1 polymorphism is a susceptibility factor for breast cancer in postmenopausal Chinese women in Taiwan. Further study with a large sample size should be considered to address issues of interactions between CYP1A1 and other risk factors.

Background:Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium.Methods:Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression.Results:Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95% confidence interval=1.02–1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2.Conclusion:Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2.

In order to explore the variation in aboveground biomass among five topographically-defined habitats in old-growth forest, we measured aboveground biomass within a 20 ha permanent plot in Southern China. Aboveground biomass was estimated by using allometric regression equations. In the present study, there was no significant difference between the average aboveground biomass in 2005 (153.7 ± 58.7 mg ha-1) and in 2010 (152.3 ± 60.8 mg ha-1). Biomass also varied substantially among habitats, from 138.9 Mg ha-1 in the higher slope and lower valley habitat to 200.1 mg ha-1 in the mountain ridge habitat in 2005, and from 132.1 mg ha-1 in the lower slope to 198.8 mg ha-1 in the mountain ridge in 2010. Medium trees were the largest contributor (48%) to the total aboveground biomass within all habitats. Variability in species contributions to total habitat biomass were suggestive of species habitat preferences. This study provides a detailed overview of aboveground biomass patterns among old-growth forest habitats and highlights the importance of incorporating community characteristics and environmental variables (i.e. topography) into forest ecosystem carbon studies. The results will further our understanding of the contributions of oldgrowth forests to global carbon cycles and provide valuable information to improve conservation planning strategies.

On the basis of the method of representative values and the flow pattern, that is, the position of the isobars parallels to the die orifice (PIPDO), the design of dies for the sheet and annular parisons is improved in the present paper. Since this pattern includes the effects of the sloped manifold and the die design for the circular manifold are independent of flow rate and the polymer viscosity, the distribution system of a die gives better uniformity of flow. In the previous study [1] a defect is found, that is, the calculated position of the path of the island area lags behind actual position. This defect is eliminated, and the modified equation is obtained. Another flow pattern, the pressure loss on all flow path is equal (PLFPE), is introduced. The equivalency of the above two flow patterns is proved theoretically. Although the flow uniformity isn’t perfect in the simplified analytical design of dies proposed in the previous paper, this simplified design is still of advantages. Therefore, its design criterion is put forward in this paper.