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Q Dai

Publications and source records attributed to Q Dai.

At least 37 records · Page 2Linked to original sources
PubMed2001

Soyfood intake during adolescence and subsequent risk of breast cancer among Chinese women.

Many experimental but few epidemiological studies have suggested that soyfoods and their constituents have cancer-inhibitory effects on breast cancer. No epidemiological study has evaluated the association of adolescent soyfood intake with the risk of breast cancer. To evaluate the effect of soyfood intake during adolescence, one of the periods that breast tissue is most sensitive to environmental stimuli, on subsequent risk of breast cancer, we analyzed data from a population-based case-control of 1459 breast cancer cases and 1556 age-matched controls (respective response rates were 91.1% and 90.3%). Information on dietary intake from ages 13-15 years was obtained by interview from all study participants and, in addition, from mothers of subjects less than 45 years of age (296 cases and 359 controls). Odds ratios (ORs) and 95% confidence intervals (CIs) derived from unconditional logistic models were used to measure soyfood intake and breast cancer risk. After adjustment for a variety of other risk factors, adolescent soyfood intake was inversely associated with risk, with ORs of 1.0 (reference), 0.75 (95% CI, 0.60-0.93), 0.69 (95% CI, 0.55-0.87), 0.69 (95% CI, 0.55-0.86), and 0.51 (95% CI, 0.40-0.65), respectively, for the lowest to highest quintiles of total soyfood intake (trend test, P < 0.001). The inverse association was observed for each of the soyfoods examined and existed for both pre- and postmenopausal women. Adolescent soyfood intakes reported by participants' mothers were also inversely associated with breast cancer risk (P for trend < 0.001), with an OR of 0.35 (95% CI, 0.21-0.60) for women in the highest soyfood intake group. Adjustment for rice and wheat products, the major energy source in the study population, and usual adult soyfood intake did not change the soyfood associations. Our study suggests that high soy intake during adolescence may reduce the risk of breast cancer in later life.

Adolescent↗
PubMed2001

[Mutations of genes affecting heart development of Drosophila].

Recent studies suggest that the basic molecular control mechanisms of early heart development are remarkably conserved in Drosophila, vertebrate and human being. Drosophila can be used as a prototype to explore the genetic basis of cardiogenesis in human being. Here, mutations of genes affecting heart development of Drosophila are produced by chemical mutagen methanesulfonicaeid ethyl. With staining of antibody expressed in heart precussor cells of Drosophila, 112 lethal lines were observed to show mutant phenotypes in pericardial cells. Of them, 32 lines differ in their mutant phenotypes from those of known genes. Analysis of cytogenetic mapping shows that they are located in 13 chromosomal regions without known heart-related genes, which implies that these loci contain genes probably involved in the heart development.

Animals↗
PubMed2001

Changes in and effective factors of microtubule-associated protein 2 in traumatic neurons.

OBJECTIVE: To investigate alterations in the microtubule-associated protein 2 (MAP-2) of neurons in Wistar rats and the effect of nimodipine (Nim), D-2-amino-5-phosphonovaleric acid (D-AP-5) and mild hypothermia on neuronal MAP-2 following fluid percussion injury (FPI). METHODS: Alterations of MAP-2 in Wistar rat neurons following FPI were measured by a confocal laser-scanning microscope using MAP-2 immunofluorescence staining as a MAP-2 indicator. RESULTS: MAP-2 immunofluorescence staining was limited to the cell bodies and dendritic compartments of neurons and more intense in dendrites than in cell bodies. The loss of MAP-2 was marked at 3 h post-trauma (P < 0.01), and reached a maximum at 48 h post-trauma. Afterwards, fluorescence recovered partly at 72 h post-trauma. The application of Nim markedly reduced the loss of MAP-2 immunoreactivity within 1 h post-trauma (P < 0.01), and the application of D-AP-5 markedly reduced the loss of MAP-2 immunoreactivity within 10 h post-injury (P < 0.01). The application of mild hypothermia decreased the loss of MAP-2 immunoreactivity within 1 h post-injury (P < 0.05). CONCLUSIONS: The partial recovery of fluorescence at 72 h post-trauma indicate that the partial structure of the neuronal microtubules can be repaired by itself. Nim, D-AP-5 and mild hypothermia reduce the degradation of MAP-2 by different mechanisms. The treatment of neuronal cytoskeleton degradation following FPI must employ multiple therapeutic approaches.

2-Amino-5-phosphonovalerate↗
PubMed2001

Population-based, case-control study of blood C-peptide level and breast cancer risk.

Insulin resistance has been suggested to be associated with an increased risk of breast cancer. Insulin sensitivity can be measured using blood C-peptide, a marker of insulin secretion. It is thus conceivable that blood C-peptide levels may be associated with breast cancer risk. To evaluate this hypothesis, we analyzed data from a subset (143 case-control pairs matched by age and status of menopause) of women who participated in the Shanghai Breast Cancer Study, a population-based, case-control study conducted in Shanghai during 1996-1998. Fasting blood samples were collected from study subjects to measure C-peptide levels. For cancer patients, the samples were collected before any cancer therapy. Conditional logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals related to C-peptide levels. Breast cancer risk was increased with increasing levels of C-peptide (trend test, P = 0.01), with an odds ratio of 2.7 (95% confidence interval = 1.2-5.9) observed for the highest compared with the lowest tertile of C-peptide concentration after adjusting for body mass index and age at the first live birth. The risk was not altered after fully adjusting for other traditional risk factors for breast cancer. This positive association was observed in both pre and postmenopausal women and regardless of the levels of waist-to-hip ratio or body mass index. The results from this study were consistent with the insulin-resistance hypothesis for breast cancer and suggest that increased levels of C-peptide may contribute to the development of breast cancer.

Adult↗
PubMed2001

[Masseter thickness measured by ultrasonography of 50 young healthy adults in relation to facial morphology].

OBJECTIVE: To quantify the normal range of the ultrasonically measured thickness of the masseter which is related to the variation of the facial morphology in different young individuals. METHODS: The masseter thickness of 50 young healthy adults (25 men and 25 women) was measured bilaterally under relaxed conditions and with maximal clenching by a real-time ultrasound imaging technique. The relation between masseter thickness and facial morphology was also observed. RESULTS: Under relaxed conditions, the mean thickness of the muscle in men was(11.83 +/- 1.19) mm, and under contracted conditions, (15.51 +/- 1.40) mm. In women, the respective measurements were(9.84 +/- 1.03) mm and (13.02 +/- 1.10) mm. In men the thickness of masseter had a negative linear correlation to the indices of FH/FWa (the ratio of the anterior facial height to the intergonial width) and FWz/FWa (the ratio of the bizygomatic facial width to the intergonial width). CONCLUSIONS: The mean thickness of the masseter in men was larger than that in women, and the thickness of the muscle was related to the male facial morphology.

Adult↗
PubMed2000

Association of menstrual and reproductive factors with breast cancer risk: results from the Shanghai Breast Cancer Study.

The incidence of breast cancer among women in Shanghai, a traditionally low-risk population, has increased substantially over the past 20 years. To evaluate the association of menstrual and reproductive factors with breast cancer risk and the influence of these factors on the temporal trend of breast cancer incidence, we analyzed data from the Shanghai Breast Cancer Study, a population-based case-control study of breast cancer recently completed among Chinese women in urban Shanghai. In-person interviews were completed for 1,459 women newly diagnosed with breast cancer between ages 25 and 64 and for 1,556 controls frequency-matched to cases by age. Unconditional logistic regression was employed to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) related to menstrual and reproductive factors. Earlier menarcheal age, nulliparity, and later age at first live birth were associated with increased risk of breast cancer among both pre- and post-menopausal women, while never having breast-fed and later age at menopause were associated with elevated risk only among post-menopausal women. Among controls, 32% of younger women (</=40 years) and 24% of older women (>40 years) reported starting menarche at age of 13 or younger, and this factor contributed to 44% of cases diagnosed among younger women and 26% to 28% of cases in older women. Older age at first live birth or at menopause explained a considerable portion of cases diagnosed in older, but not younger, women. Our study suggests that the changes in menstrual and reproductive patterns among women in Shanghai have contributed to the recent increase in breast cancer incidence, particularly among younger women.

Adult↗
PubMed2000

Population-based, case-control study of HER2 genetic polymorphism and breast cancer risk.

BACKGROUND: Alterations of the HER2 (also known as erbB-2 or neu) proto-oncogene have been implicated in the carcinogenesis and prognosis of breast cancer. A polymorphism at codon 655 (GTC/valine to ATC /isoleucine [Val(655)Ile]) in the transmembrane domain-coding region of this gene has been identified and may be associated with the risk of breast cancer. We evaluated this hypothesis in a subgroup of women who participated in a large-scale, population-based, case-control study of breast cancer in Shanghai, China. METHODS: Genomic DNA from 339 patients with breast cancer and 361 healthy control subjects was examined for the Val(655)Ile polymorphism with a polymerase chain reaction-restriction fragment-length polymorphism-based assay. All study subjects completed a structured questionnaire during an in-person interview. All P values are from two-sided tests. RESULTS: We found that 25.1% of the case patients and 21.7% of the control subjects were heterozygous for the Val allele and 3.2% of the case patients and 0. 3% of the control subjects were homozygous for this allele (P =.005). Compared with women with the Ile/Ile genotype, women who had the Ile/Val or Val/Val genotype had an elevated risk of breast cancer (odds ratio [OR] = 1.4; 95% confidence interval [CI] = 1.0-2.0; P =. 05) after adjustment for age, educational level, study period, history of breast fibroadenoma, leisure physical activity, and age at first live birth. The risk was elevated even more among women who were homozygous for the Val allele (OR = 14.1; 95% CI = 1.8-113.4). The association was more pronounced among younger women (</=45 years) than among older women (>45 years). The adjusted OR associated with the Val allele was 1.7 (95% CI = 1.1-2.6) for younger women and 1.0 (95% CI = 0.5-1.9) for older women. CONCLUSIONS: Results of this study suggest that polymorphisms of the HER2 gene may be important susceptibility biomarkers for breast cancer risk, particularly among younger women.

Adult↗
PubMed2000

Genetic polymorphism of cytochrome P450-1B1 and risk of breast cancer.

Cytochrome P450-1B1 (CYP1B1) is a major enzyme catalyzing the formation of genotoxic 4-hydroxyestradiol. This enzyme is also involved in the activation of polycyclic aromatic hydrocarbons and heterocyclic aromatic amines, mammary carcinogens in experimental animals. CYP1B1 is genetically polymorphic, and the variations in the CYP1B1 gene may be related to the risk of breast cancer. We evaluated this hypothesis among 186 breast cancer cases and 200 age-matched controls as part of a large population-based case-control study conducted in urban Shanghai during 1996 to 1998. Genomic DNA from cases and controls was analyzed for genetic polymorphism in codon 432 (Val-->Leu) of the CYP1B1 gene using a PCR-RFLP-based assay. The frequency of the Leu allele was 53% in cases and 46% in controls (P = 0.06). Compared with those with the Val/Val genotype, women with the Leu/Leu genotype had a 2.3-fold [95% confidence interval (CI), 1.2-4.5] elevated risk of breast cancer after adjusting for potential confounding variables. This positive association was more pronounced among postmenopausal women (Odds ratio, 3.1; 95% CI, 1.0-9.1) than premenopausal women (OR, 1.9; 95% CI, 0.8-4.3). Elevated risks of breast cancer associated with homozygosity for the Leu allele were observed in virtually all subgroups of women defined by major risk factors for breast cancer. The results from this study were consistent with recent findings from in vitro and animal experiments implicating a potentially important role of CYP1B1 in the etiology of human breast cancer.

Adult↗
PubMed2000

[Chronic low dose follicle stimulating hormone step-up regimen in the treatment of polycystic ovary syndrome related anovulatory infertility with clomiphene resistance].

OBJECTIVE: To assess the efficacy and safety of chronic low-dose follicle stimulating hormone (FSH) step-up regimen in ovulation induction of polycystic ovary syndrome(PCOS) related infertile patients with clomiphene (CC) resistance. METHODS: Nine PCOS related infertile patients with CC resistance were enrolled for ovulation induction by chronic low-dose FSH step-up regimen, using urinary FSH (Metrodin) or recombinant human FSH (Gonal-F) 5 cycles respectively. Follicular development was monitored by transvaginal ultrasonography and serum estradiol (E2) measurements. RESULTS: Nine out of ten cycles ovulated, among them 5 had monofollicle development, one achieved single pregnancy. No ovarian hyperstimulation syndrome(OHSS), local or systemic side effect was seen. CONCLUSION: Chronic low-dose FSH step-up regimen is an effective and safe choice in inducing ovulation for CC-resistant PCOS infertile cases. Transvaginal ultrasonography and serum E2 measurement are equally important for appropriate dose adjustment and avoidance of cancellation or OHSS.

Anovulation↗
PubMed2000

[The sensitivity to apoptosis is enhanced in U937-ASPI-3K cells which stably express antisense ATM/PI-3K].

OBJECTIVE: To analyse the characteristics of apoptosis sensitivity in U937-ASPI-3K cells which is stably expressing anti-sense ATM/PI-3K. METHOD: Annexin V-PI apoptosis detection kid and flow cytometry were used to determine apoptosis rate, Western blot to the expression level of cytochrome C protein and Bcl-2 protein. RESULTS: U937-ASPI-3K cells had a lowered threshold for triggering apoptosis in response to low dose irradiation. Cell apoptosis rate was 28% and (53.0 +/- 5.4)%, respectively, at 8 and 48 hours after 1.5 Gy (137)Cs irradiation, while in U937-pZEOSV2 (+) control group it was 4.2% and (11.0 +/- 3.3)%, respectively. Cytosolic cytochrome C protein band was gradually intensified in U937-ASPI-3K in 4 - 8 h after irradiation, but was not detected in control group. Bcl-2 protein gradually decreased in U937-ASPI-3K in 4 - 8 h after irradiation, but didn't change obviously in control group. CONCLUSION: Cell line U937-ASPI-3K acquired a phenotype with a lowered threshold for triggering apoptosis. It demonstrated that selective inactivation of ATM gene might be of considerable value in tumor treatment.

Apoptosis↗
PubMed2000

Protective effect of melatonin on neural cells against the cytotoxicity of oxyradicals.

OBJECTIVE: To investigate the exact mechanism of melatonin to prohibit the apoptosis of neural cells induced by various kinds of cytotoxic agents. METHODS: We used the methods of phase contrast microscopy, MTT assay and hoechst dye staining to check this mechanism in SKNSH and U251 cell lines. RESULTS: Both 2 mmol/L H2O2 and 0.5 micromol/L amyloid beta-protein (Abeta) induce these two cell lines die via apoptosis. Either melatonin or glutathione can significantly protect both cell lines. The protective effect of 10 micromol/L melatonin is as same as that of 60 micromol/L glutathione. CONCLUSION: Melatonin can partly inhibit the cytotoxicity of H2O2 and Abeta through its role as a free radical scavenger.

Amyloid beta-Peptides↗
PubMed1999

[Studies on 14 functional foods labelled with tumor inhibition effects].

Tumor inhibition effects of 14 functional foods were measured. Test items included sarcoma 180(S180) inhibiting test, Ehrlich ascites carcinoma (EAC) inhibiting test, phagocyte phagocytosis test and NK cell activity test. The results showed dose-response tendencies in all indices. But the tumor inhibition rate and survival time were decreased in high dose groups and even lower than those of control group (P < 0.05) in some samples. Correlation analysis showed a positive correlation between tumor inhibition rate and survival time, phagocytic percentage and phagocytic index, phagocytic percentage and NK activity, phagocytic index and NK activity (P < 0.01). Tumor inhibition rate and phagocytic percentage appeared negative correlation (P < 0.05). It is suggested that the present methods should be modified. The new and better methods needed to be established. The judge criterion for functional food should be strictly enacted. More Studies needed to be repeated for some foods with significant tumor inhibition functions.

Adjuvants, Immunologic↗
PubMed1999

Study of diet, biomarkers and cancer risk in the United States, China and Costa Rica.

One striking paradox in epidemiologic research is the strong association between diet and cancer in ecologic studies compared with the weaker associations reported in many within-country case-control and cohort studies. However, most ecologic studies have relied on indirect measures of dietary intake, such as food disappearance data. The objectives of our study were to assess the feasibility of collecting dietary and biomarker data from individuals living in countries having markedly different dietary patterns and cultures and to examine the magnitude of the between-country variation in their measurement. Adults surveyed in Shanghai (China), Costa Rica and King County (Washington, USA) completed a 24-hr dietary recall, a cancer risk factor survey, and provided a blood sample. We analyzed a subset of the blood specimens for vitamins C, E, carotenoids and phospholipid fatty acids. We observed substantial differences in nutrient intakes and in mean plasma concentrations of dietary biomarkers across the study populations. For example, King County participants had the highest daily intake of vitamin C (mean 78.3 +/- 12.2 mg compared with 42.6 +/- 38.3 mg in Shanghai and 34.8 +/- 43.8 mg in Costa Rica). The mean plasma vitamin C level in King County was also the highest of the 3 study sites: 927.9 +/- 43.9 microg/dl in King County, 585.7 +/- 35.9 microg/dl in Shanghai and 461.1 +/- 33.1 microg/dl in Costa Rica. Plasma trans fatty acids (a biomarker of a diet high in hydrogenated fats) were highest in King County and lowest in Shanghai.

Adult↗
PubMed1999

Occupation and pancreatic cancer risk in Shanghai, China.

BACKGROUND: Any association between occupation and pancreatic cancer risk has not been conclusively demonstrated. A population-based case-control study was conducted to examine occupational risks of pancreatic cancer in Shanghai, China. METHODS: The study included 451 pancreatic cancer patients newly diagnosed in 1990-1993 and 1,552 controls randomly selected from Shanghai residents. Information on a lifetime job history and other factors was obtained in a face-to-face interview. RESULTS: Among men, an increased risk of pancreatic cancer was associated with employment as an electrician (OR = 7.5, CI = 2.6-21.8), and a positive trend in risk with increasing duration of employment was apparent (P for trend = 0.0003). Exposure to electric magnetic fields (EMF) as measured by a job exposure matrix also was associated with an increased risk among electricians. Threefold risks were observed for men with the highest level of intensity and for those with the highest probability of EMF exposure, although women with heavy EMF exposure did not experience increased risk. Among men, elevated risks also were found for metal workers (OR = 2.1, CI = 1.0-4.8); toolmakers (OR = 3.4, CI = 14-7.1); plumbers and welders (OR = 3.0, CI = 1.2-7.5); and glass manufacturers, potters, painters, and construction workers (OR = 2.6, CI = 1.1-6.3). Among women, textile workers experienced an increased risk (OR = 1.4, CI = 0.8-2.6). CONCLUSIONS: Our results suggest that occupations associated with exposures to metal and textile dusts or certain chemicals may increase the risk of pancreatic cancer. The elevated risk among electricians may warrant further study to evaluate the possible role of EMF or other exposures.

Aged↗
PubMed1999

Usual dietary consumption of soy foods and its correlation with the excretion rate of isoflavonoids in overnight urine samples among Chinese women in Shanghai.

Soy foods and certain soy constituents, particularly isoflavones, have been suggested to have potential cancer-inhibitory effects in laboratory and epidemiological studies. Chinese women in Shanghai consume high levels of soy foods and have low incidence rates of breast and other hormone-related cancers. To assess the usual dietary consumption of soy foods and evaluate the correlation of soy food consumption with the urinary excretion of isoflavonoids in overnight urine samples in this population, we analyzed data from 60 healthy women included in an ongoing population-based case-control study of breast cancer in Shanghai. Usual consumption of soy foods in the previous five-year period was assessed using a food-frequency questionnaire, and urinary excretion of daidzein, genistein, glycitein, equol, and O-desmethylangolensin was measured from overnight urine samples collected at the time of dietary assessment. Virtually all women (96.7%) in Shanghai consumed soy foods at least once a week. The median intake of soy food was 100.6 g/day, with 25th and 75th percentiles of 36.8 and 238.2 g, respectively. The median intake of isoflavones was 39.26 mg/day, and there was a nearly fourfold difference between the 25th and 75th percentiles of this measurement. With the increasing intake of soy foods, urinary excretion rates of total isoflavonoids and all individual major isoflavonoids were increased in a dose-response manner (trend test p < or = 0.05). At individual levels the urinary excretion rate of total isoflavonoids was correlated closely with dietary soy food intake, with a correlation coefficient of around 0.5 (p < 0.001). These results indicate that the urinary excretion rate of total isoflavonoids measured from overnight urine samples may reflect reasonably well the usual intake of soy foods in a population with a high level of soy food consumption.

Adult↗
PubMed1999

[Treatment of polycystic ovary syndrome and related infertility with clomiphene resistance by compound cyproterone acetate].

OBJECTIVE: To assess the efficacy and safety of compound cyproterone acetate (CPA Co, or Diane-35) in the treatment of polycystic ovary syndrome (PCOS) and to explore its potential role in improving the outcome of ovulation induction in clomiphene (CC) resistant cases. METHODS: Twenty-nine proven PCOS patients were enrolled. Seventeen out of them, including 16 who were resistant to CC, had anovulatory infertility. CPA Co was given for 4-6 cycles. Serum luteinizing hormone(LH), follicle stimulating hormone(FSH), estradiol(E2), testosterone(T), androstenedione(A), dehydroepiandrosterone (Ds), sex hormone binding globvlin (SHBG), insulin concentrations, total cholesterol, triglycerides(TG), high density lipoprotein-cholesterol(HDL-C), low density lipoprotein-cholesterol (LDL-C), apolipoprotein A, apolipoprotein B and transvaginal pelvic ultrasonography were determined before, 2-3 cycles and 4-6 cycles after treatment. After stopping the drug, CC or human menopausal gonadotropin were re-administered in 12 patients (22 cycles) and 5 cases (6 cycles) respectively for induction of ovulation. RESULTS: All patients had regular uterine bleeding during CPA Co therapy. Acne improved in 8 cases. Hirsute score didn't decrease significantly. Serum LH, FSH, E2, A, T, Ds concentrations decreased significantly (P < 0.05-0.01), while SHBG levels increased by 5.1 times after treatment. Meanwhile, bilateral ovarian volumes shrunk and follicle numbers decreased significantly (P < 0.05-0.01). Serum insulin levels did not change significantly. As to the lipid profile, the most striking change was 55.1% increase of HDL-C and 23.0% decrease of LDL-C, although TG also increased by 36.2%. 58.6% of patients had mild and transient adverse effects. Serum alanine transaminase increased in 3 cases. After stopping treatment, CC induced 5.3% (by cases) or 45.4% (by cycles) ovulation rate and 2 pregnancies achieved in 12 CC resistant patients. CONCLUSION: CPA Co has antiandrogenic effects on PCOS patients clinically, biochemically and in ovarian morphology. Pretreatment of CPA Co may play a role in improving the outcome of ovulation induction in CC resistant cases.

Adult↗
PubMed1999

Feasibility study of an ultrasound contrast agent (levovist) in color Doppler imaging of liver neoplasms.

The purpose of this study was to determine the efficacy of using an ultrasound contrast agent (levovist) to enhance the color Doppler imaging of liver neoplasms. Thirty patients with hepatic tumors were enrolled in this study. After intravenous administration of levovist, the color Doppler signals of normal hepatic vessels were enhanced. In various hepatic tumors, the different patterns of tumor vascularity were observed, which had not been demonstrated in conventional non-contrast color Doppler imaging. In 11 of 16 patients with hepatocarcinoma, additional color Doppler signals were observed in the central part of the tumors. On the contrary, 3 patients with metastatic liver lesions the enhanced color Doppler signals appear only at the peripheral of tumors. A typical rim-like color enhancement was seen in 2 of the 3 cases. In six patients with hepatic hemangiomas contrast-enhanced color Doppler imaging demonstrated the blood vessels at the margin of the neoplasms. Contrast-enhanced color Doppler imaging improves the visualization of the hepatic neoplasm vascularity. This technique holds great promise for detecting small liver tumors and differentiating hepatic neoplasms.

Adult↗