Biomedical subjects

Ping Sun

Publications and source records attributed to Ping Sun.

At least 55 records · Page 3Linked to original sources

PubMed2006

Endometrial cancer risk is associated with variants of the mismatch repair genes MLH1 and MSH2.

Women with germ-line mutations in the mismatch repair genes (responsible for hereditary nonpolyposis colorectal cancer) face an increased risk of colonic and endometrial cancer. However, these germ-line mutations are rare and are responsible for fewer than 1% of endometrial cancers. Therefore, we examined whether or not common variants of the hereditary nonpolyposis colorectal cancer-associated genes might also be associated with an increased risk of endometrial cancer. Three single-nucleotide polymorphisms were selected in the MLH1 and MSH2 mismatch repair genes. All the various 672 women with endometrial cancer and 880 controls were genotyped. Each of these three single-nucleotide polymorphisms was associated with an increased risk of endometrial cancer. Carriers of the MLH1 nt-93 A allele were at a 1.5-fold increased risk of developing endometrial cancer compared with controls [95% confidence interval (95% CI), 1.2-2.0; P = 0.001]. The risk was higher for homozygote carriers [odds ratio (OR), 1.9; 95% CI, 1.2-3.2; P = 0.009]. For carriers of the MSH2 rs2303428 C allele, the OR was 1.4 (95% CI, 1.0-1.9; P = 0.05), and for carriers of the MSH2 rs2059520 G allele, the OR was 1.3 (95% CI, 1.0-1.7; P = 0.03). More than 9% of endometrial cancer cases carried a variant allele in both MLH1 and MSH2. For these women, the risk of endometrial cancer was particularly high (OR, 2.1; 95% CI, 1.2-3.6; P = 0.005). For patients younger than 50 years at diagnosis who carried both variants, the risk was even higher (OR, 3.4; 95% CI, 1.7-6.6; P = 0.0005). In summary, two common variant alleles of the MLH1 and MSH2 genes make a substantial contribution to endometrial cancer incidence in Ontario.

Adaptor Proteins, Signal Transducing↗

PubMed2006

[Cardiac function of children with bronchial asthma].

OBJECTIVE: To explore the cardiac function of left and right ventricles in children with bronchial asthma at the acute stage and its association with the disease severity. METHODS: The cardiac function was evaluated by using the American Acuson 128XP/10 Doppler echocardiography in 24 children with acute severe bronchial asthma and 40 children with acute mild bronchial asthma. Thirty-four healthy children were used as normal controls. RESULTS: The injury of right ventricle diastolic function was predominant in children with mild asthma, and the right ventricle systolic function was also decreased. The systolic and diastolic function of left ventricle remained normal. In children with severe bronchial asthma, the injury of left ventricle systolic function was commonly seen, and the left ventricle diastolic function and the right ventricle systolic and diastolic function were also damaged. CONCLUSIONS: The cardiac function damage occurs in children with acute bronchial asthma and may be correlated with the disease severity.

Asthma↗

PubMed2005

Effect of pregnancy as a risk factor for breast cancer in BRCA1/BRCA2 mutation carriers.

Early age at first birth and multiparity have been associated with a decrease in the risk of breast cancer in women in the general population. We examined whether this relationship is also present in women at high risk of breast cancer due to the presence of a mutation in either of the 2 breast cancer susceptibility genes, BRCA1 or BRCA2. We performed a matched case-control study of 1,260 pairs of women with known BRCA1 or BRCA2 mutations, recruited from North America, Europe and Israel. Women who had been diagnosed with breast cancer were matched with unaffected control subjects for year of birth, country of residence, and mutation (BRCA1 or BRCA2). Study subjects completed a questionnaire detailing their reproductive histories. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived by conditional logistic regression. Among BRCA1 carriers, parity per se was not associated with the risk of breast cancer (OR for parous vs. nulliparous = 0.94; 95% CI = 0.75-1.19; p = 0.62). However, women with a BRCA1 mutation and 4 or more children had a 38% decrease in breast cancer risk compared to nulliparous women (OR = 0.62; 95% CI = 0.41-0.94). In contrast, among BRCA2 carriers, increasing parity was associated with an increased risk of breast cancer; women with 2 or more children were at approximately 1.5 times the risk of breast cancer as nulliparous women (OR = 1.53; 95% CI = 1.01-2.32; p = 0.05). Among women with BRCA2 mutations and who were younger than age 50, the (adjusted) risk of breast cancer increased by 17% with each additional birth (OR = 1.17; 95% CI = 1.01-1.36; p = 0.03). There was no significant increase in the risk of breast cancer among BRCA2 carriers older than 50 (OR for each additional birth = 0.97; 95% CI = 0.58-1.53; p = 0.92). In the 2-year period following a birth, the risk of breast cancer in a BRCA2 carrier was increased by 70% compared to nulliparous controls (OR = 1.70; 95% CI = 0.97-3.0). There was a much smaller increase in breast cancer risk among BRCA2 carriers whose last birth was 5 or more years in the past (OR = 1.24; 95% CI = 0.79-1.95). A modest reduction in risk of breast cancer was observed among BRCA1 carriers with 4 or more births. Among BRCA2 carriers, increasing parity was associated with a significant increase in the risk of breast cancer before age 50 and this increase was greatest in the 2-year period following a pregnancy.

Adolescent↗

PubMed2005

Positive inter-regulation between beta-catenin/T cell factor-4 signaling and endothelin-1 signaling potentiates proliferation and survival of prostate cancer cells.

Both malignant and normal prostate epithelial cells produce endothelin-1 (ET-1), a critical factor in prostate cancer (CaP) progression. beta-Catenin (beta-cat), a key component of the Wnt signaling pathway, is also implicated in CaP progression via beta-cat/T cell factor (Tcf) signaling. We recently demonstrated that beta-cat/Tcf-4 regulates transcription of ET-1 in colon cancer cells. In the present study, we found that Tcf-4 specifically bound to and activated the ET-1 promoter in vivo in human CaP cells and mouse prostate tissue. Expression of ET-1 in DU145 CaP cells was down-regulated by knocking down endogenous beta-cat or Tcf-4. Ectopic activation of beta-cat/Tcf-4 signaling significantly elevated expression of ET-1 in LNCaP cells. In addition, genetic ablation of beta-cat significantly inhibited transcription of ET-1 in primary prostate epithelial cells. Meanwhile, exogenous ET-1 enhanced beta-cat/Tcf signaling and ET-1 expression in DU145 cells, which was blocked by both selective phosphatidylinositol 3-kinase (PI3K) inhibitor 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002) and endothelin-A receptor antagonist cyclo(L-Leu-D-Trp-D-Asp-L-Pro-D-Val) (BQ123). Furthermore, knockdown of either beta-cat or Tcf-4 substantially reduced cell proliferation and potentiated paclitaxel-induced apoptosis in DU145 cells, which largely were rescued by treatment with exogenous ET-1. Together, our results suggest that beta-cat/Tcf-4 signaling transcriptionally activates ET-1 in CaP cells; meanwhile, ET-1 enhances beta-cat/Tcf-4 signaling and in turn further increases ET-1 expression in a PI3K-dependent manner. The positive inter-regulation between beta-cat/Tcf-4 signaling and ET-1 signaling potentiates proliferation and survival of CaP cells, thereby representing a novel mechanism that contributes to CaP progression.

Animals↗

PubMed2005

A novel RING-type ubiquitin ligase breast cancer-associated gene 2 correlates with outcome in invasive breast cancer.

The RING finger family of proteins possess ubiquitin ligase activity and play pivotal roles in protein degradation and receptor-mediated endocytosis. In this study, we examined whether the breast cancer-associated gene 2 (BCA2), a novel RING domain protein, has E3 ubiquitin ligase activity and investigated its expression status in breast tumors. The full-length BCA2 gene was cloned from the human breast cancer cell line MDA-MB-468. It encodes an open reading frame of 304 amino acids and contains a RING-H2 domain. BCA2 maps to chromosome 1q21.1, a region known to harbor cytogenetic aberrations in breast cancers. We found that the BCA2 protein has an intrinsic autoubiquitination activity, the hallmark of E3 ligases, whereas mutant RING protein is not autoubiquitinated. This indicates that the BCA2 ubiquitin ligase activity is dependent on the RING-H2 domain. Using tissue microarrays and immunohistochemistry, we found strong to intermediate BCA2 staining in 56% of 945 invasive breast cancers cases, which was significantly correlated with positive estrogen receptor status [odds ratio (OR), 1.51; P = 0.004], negative lymph node status (OR, 0.73; P = 0.02), and an increase in disease-free survival for regional recurrence (OR, 0.45; P = 0.03). Overexpression of BCA2 increased proliferation and small interfering RNA inhibited growth of T47D human breast cancer cells and NIH3T3 mouse cells. The autoubiquitination activity of BCA2 indicates that it is a novel RING-type E3 ligase. Its association with clinical measures and its effects on cell growth indicate that BCA2 may be important for the ubiquitin modification of proteins crucial to breast carcinogenesis and growth.

Adult↗

PubMed2005

Downregulation of MDM2 expression by RNAi inhibits LoVo human colorectal adenocarcinoma cells growth and the treatment of LoVo cells with mdm2siRNA3 enhances the sensitivity to cisplatin.

To investigate the biological effect of mdm2 in human colorectal adenocarcinoma LoVo cells, three mdm2siRNA constructions were recombined and transient transfected into human colorectal adenocarcinoma LoVo cells with low differentiation character in vitro. The results showed that mdm2siRNA3 reduced mRNA level of mdm2 and protein level of mdm2, leading to proliferation inhibition on LoVo cells, and reduced tumor growth in nude mice. It was found that depletion of MDM2 in this pattern promoted apoptosis of LoVo cells and Cisplatin (DDP) treated in the mdm2siRNA3 transfected cell population would result in a substantial decrease by MTT colorimetry. Decreasing the MDM2 protein level in LoVo cells by RNAi could significantly inhibit tumor growth both in vitro and in vivo, which indicated that mdm2 gene played a definite role in the development and aggressiveness of human colon carcinoma. It also could be a therapeutic target in colorectal carcinoma. The synergistic activation of RNAi and cell toxicity agents indicated that the combination of chemotherapy and gene therapy will be a promising approach in the future.

Adenocarcinoma↗

PubMed2005

Breast cancer risk following bilateral oophorectomy in BRCA1 and BRCA2 mutation carriers: an international case-control study.

PURPOSE: The purpose of this study was to estimate the extent of protection offered against breast cancer by prophylactic oophorectomy in carriers of BRCA1 or BRCA2 mutations and to determine to what extent risk reduction varies with age at oophorectomy, age at diagnosis, and time elapsed since surgery. PATIENTS AND METHODS: We analyzed 1,439 patients with breast cancer and 1,866 matched controls derived from a registry of BRCA1 and BRCA2 carriers. We estimated odds ratios (ORs) of breast cancer for having had a bilateral oophorectomy, using conditional logistic regression, matched for parity and for oral contraceptive use. RESULTS: A previous history of oophorectomy was associated with a significant reduction in breast cancer risk of 56% for BRCA1 carriers (OR = 0.44; 95% CI, 0.29 to 0.66) and of 46% for BRCA2 carriers (OR = 0.57; 95% CI, 0.28 to 1.15). The risk reduction was greater if the oophorectomy was performed before age 40 (OR = 0.36; 95% CI, 0.20 to 0.64 for BRCA1 carriers) than after age 40 (OR = 0.53; 95% CI, 0.30 to 0.91). The protective effect was evident for 15 years post-oophorectomy (OR = 0.39; 95% CI, 0.26 to 0.57). CONCLUSION: Oophorectomy is an effective means of reducing the risk of breast cancer in carriers of BRCA1 mutations. The data suggest oophorectomy is protective in BRCA2 carriers as well, but needs to be confirmed in other studies.

Adult↗

PubMed2005

Crystal structures of an intein from the split dnaE gene of Synechocystis sp. PCC6803 reveal the catalytic model without the penultimate histidine and the mechanism of zinc ion inhibition of protein splicing.

The first naturally occurring split intein was found in the dnaE gene of Synechocystis sp. PCC6803 and belongs to a subclass of inteins without a penultimate histidine residue. We describe two high-resolution crystal structures, one derived from an excised Ssp DnaE intein and the second from a splicing-deficient precursor protein. The X-ray structures indicate that His147 in the conserved block F activates the side-chain N(delta) atom of the intein C-terminal Asn159, leading to a nucleophilic attack on the peptide bond carbonyl carbon atom at the C-terminal splice site. In this process, Arg73 appears to stabilize the transition state by interacting with the carbonyl oxygen atom of the scissile bond. Arg73 also seems to substitute for the conserved penultimate histidine residue in the formation of an oxyanion hole, as previously identified in other inteins. The finding that the precursor structure contains a zinc ion chelating the highly conserved Cys160 and Asp140 reveals the structural basis of Zn2+-mediated inhibition of protein splicing. Furthermore, it is of interest to observe that the carbonyl carbon atom of Asn159 and N(eta) of Arg73 are 2.6 angstroms apart in the free intein structure and 10.6 angstroms apart in the precursor structure. The orientation change of the aromatic ring of Tyr-1 following the initial acyl shift may be a key switching event contributing to the alignment of Arg73 and the C-terminal scissile bond, and may explain the sequential reaction property of the Ssp DnaE intein.

Bacterial Proteins↗

PubMed2005

Hormone replacement therapy and the risk of ovarian cancer in BRCA1 and BRCA2 mutation carriers.

OBJECTIVE: Hormone replacement therapy (HRT) is commonly prescribed to alleviate the climacteric symptoms of menopause. Recent findings from the Women's Health Initiative has raised questions about the routine use of HRT due to the increased observed incidence of cardiovascular disease and of breast and ovarian cancers in the treatment arm of the trial. In the general population, the association between HRT use and risk of ovarian cancer has not yet been resolved. This association has not been evaluated in BRCA1 or BRCA2 mutation carriers who face very high lifetime risks of both breast and ovarian cancers. METHODS: We conducted a matched case-control study on 162 matched sets of women who carry a deleterious mutation in either the BRCA1 or BRCA2 gene. Women who had been diagnosed with ovarian cancer were matched to control subjects by mutation, year of birth, and age at menopause. Information on HRT use was derived from a questionnaire routinely administered to women who were found to be carriers of a mutation in either gene. Conditional logistic regression was used to estimate the association between HRT use and the risk of ovarian cancer, stratified by mutation status and type of HRT. RESULTS: Compared with those who had never used HRT, the odds ratio associated with ever use of HRT was 0.93 (95% CI = 0.56-1.56). There was no significant relationship with increasing duration of HRT use. There was a suggestion that progestin-based HRT regimens might protect against ovarian cancer (odds ratio = 0.57) but this association was not statistically significant (P = 0.20). CONCLUSION: HRT use does not appear to adversely influence the risk of ovarian cancer in BRCA mutation carriers.

Aged↗

PubMed2005

Changes in body weight and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.

BACKGROUND: Several anthropometric measures have been found to be associated with the risk of breast cancer. Current weight, body mass index, and adult weight gain appear to be predictors of postmenopausal breast cancer. These factors have been associated with a reduced risk of premenopausal breast cancer. We asked whether there is an association between changes in body weight and the risk of breast cancer in women who carry a mutation in either breast cancer susceptibility gene, BRCA1 or BRCA2. METHODS: A matched case-control study was conducted in 1,073 pairs of women carrying a deleterious mutation in either BRCA1 (n = 797 pairs) or BRCA2 (n = 276 pairs). Women diagnosed with breast cancer were matched to control subjects by year of birth, mutation, country of residence, and history of ovarian cancer. Information about weight was derived from a questionnaire routinely administered to women who were carriers of a mutation in either gene. Conditional logistic regression was used to estimate the association between weight gain or loss and the risk of breast cancer, stratified by age at diagnosis or menopausal status. RESULTS: A loss of at least 10 pounds in the period from age 18 to 30 years was associated with a decreased risk of breast cancer between age 30 and 49 (odds ratio (OR) = 0.47; 95% confidence interval (CI) 0.28-0.79); weight gain during the same interval did not influence the overall risk. Among the subgroup of BRCA1 mutation carriers who had at least two children, weight gain of more than 10 pounds between age 18 and 30 was associated with an increased risk of breast cancer diagnosed between age 30 and 40 (OR = 1.44, 95% CI 1.01-2.04). Change in body weight later in life (at age 30 to 40) did not influence the risk of either premenopausal or postmenopausal breast cancer. CONCLUSION: The results from this study suggest that weight loss in early adult life (age 18 to 30) protects against early-onset BRCA-associated breast cancers. Weight gain should also be avoided, particularly among BRCA1 mutation carriers who elect to have at least two pregnancies.

Adolescent↗

PubMed2005

Gaseous mercury from curing concretes that contain fly ash: laboratory measurements.

Total gaseous mercury in headspace air was measured for enclosed concretes dry curing at 40 degrees C for intervals of 2, 28, and 56 days. Release of mercury was confirmed for ordinary Portland cement concrete (OPC) and three concretes in which class F fly ash substituted for a fraction of the cement: (a) 33% fly ash (FA33), (b) 55% fly ash (FA55), and (c) 33% fly ash plus 0.5% mercury-loaded powdered activated carbon (HgPAC). Mean rates of mercury release (0.10-0.43 ng/day per kg of concrete) over the standard first 28 days of curing followed the order OPC < FA33 approximately FA55 < HgPAC. The mercury flux from exposed surfaces of these concretes ranged from 1.9 +/- 0.5 to 8.1 +/-2.0 ng/m(2)/h, values similar to the average flux for multiple natural substrates in Nevada, 4.2 +/- 1.4 ng/m(2)/h, recently published by others. Air sampling extending for 28 days beyond the initial 28-day maturation for OPC, FA55, and HgPAC suggested that the average Hg release rate by OPC is constant over 56 days and that mercury release rates for FA55 and HgPAC may ultimately diminish to levels exhibited by OPC concrete. The release of mercury from all samples was less than 0.1% of total mercury content over the initial curing period, implying that nearly all of the mercury was retained in the concrete.

Air Pollutants↗

PubMed2005

A genetic variant c.553G > T in the apolipoprotein A5 gene is associated with an increased risk of coronary artery disease and altered triglyceride levels in a Chinese population.

Elevation in plasma triglycerides (TG) has been widely accepted as a coronary artery disease (CAD) risk predictor. Recently, a new apolipoprotein playing an important role in TG metabolism named apolipoprotein AV (apoAV) was discovered, which is encoded by the APOA5 gene. Several single nucleotide polymorphisms (SNPs) of APOA5 associated with increased TG concentrations have been identified. We here report that a recently identified genetic variant, c.553G>T in the APOA5 gene which causes a substitution of a cysteine for a glycine residue at amino acid residue 185(G185C) is also associated with increased TG levels. To investigate the association between this genetic variation and the risk of CAD, a case-control study comprising 232 patients with CAD and 302 controls from the same area of China was performed. The minor allele frequencies of c.553G > T for the CAD and control groups were 7.76 and 3.97%, respectively (P = 0.008). In both the CAD and control groups, the T allele carriers had higher serum TG levels than homozygous carriers of the major G allele (CAD group: 2.67 +/- 1.48 mmol/l versus 1.95 +/- 1.02 mmol/l, P = 0.021; controls: 2.31 +/- 1.20 mmol/l versus 1.68 +/- 0.95 mmol/l, P = 0.002). After adjustment for age, gender, body mass index, smoking status, glucose and presence of hypertension, the odds ratio (OR) for CAD in the T allele carriers was 2.089 (95% CI = 1.140-3.830, P = 0.017), in comparison to the individuals without the T allele. These results suggest that the APOA5 c.553G > T polymorphism is an important predictor for hypertriglyceridemia and CAD.

Amino Acid Substitution↗

PubMed2005

Understanding the heavy fermion phenomenology from a microscopic model.

We solve the 3D periodic Anderson model using a two impurity cluster dynamical mean field theory. We obtain the temperature versus hybridization phase diagram. Approaching the quantum critical point (QCP) both the Néel and lattice Kondo temperatures decrease and they do not cross at the lowest temperature we reached. While strong ferromagnetic spin fluctuation on the Kondo side is observed, our result suggests the critical static spin susceptibility is local in space at the QCP. We observe in the crossover region a logarithmic temperature dependence in the specific heat coefficient and spin susceptibility.

Journal Article↗

PubMed2005

Characterization of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash using different extraction methods.

In this study, traditional Soxhlet, automatic Soxhlet and ultrasonic extraction techniques were employed to determine the speciation and concentration of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash samples collected from the baghouse of a spreader stoker boiler. To test the efficiencies of different extraction methods, LSD ash samples were doped with a mixture of 16 US EPA specified PAHs to measure the matrix spike recoveries. The results showed that the spike recoveries of PAHs were different using these three extraction methods with dichloromethane (DCM) as the solvent. Traditional Soxhlet extraction achieved slightly higher recoveries than automatic Soxhlet and ultrasonic extraction. Different solvents including toluene, DCM:acetone (1:1 V/V) and hexane:acetone (1:1 V/V) were further examined to optimize the recovery using ultrasonic extraction. Toluene achieved the highest spike recoveries of PAHs at a spike level of 10 microg kg(-1). When the spike level was increased to 50 microg kg(-1), the spike recoveries of PAHs also correspondingly increased. Although the type and concentration of PAHs detected on LSD ash samples by different extraction methods varied, the concentration of each detected PAH was consistently low, at microg kg(-1) levels.

Calcium Compounds↗

PubMed2005

Explaining the link between violence perpetration, victimization and drug use.

This study examined relationships between illegal and legal drug use and violence perpetration and victimization as well as possible mediators of these relationships. Subjects were continuation high school students followed prospectively over 5 years. Results indicated that illegal drug use predicted violence and victimization 5 years later and that earlier victimization was also associated with later illegal drug use. A measure intending to tap a psychopharmacological effects system, consistent with its definition in [Goldstein, P. J. (1985). The drugs/violence nexus: A tripartite conceptual framework. Journal of Drug Issues, 15(4), 493-506] tripartite model, was found to mediate the relationships between illegal drug use and victimization and violence. Results suggest that violence and victimization prevention efforts may benefit by addressing the psychopharmacological effects of adolescent illegal drug use.

Adolescent↗

PubMed2005

Age at menarche and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.

Age at menarche is a strong and consistent predictor of breast cancer risk in the general population, but has not been well studied in women with a family history of breast cancer. We conducted this study to examine whether the presence of a deleterious BRCA1 or BRCA2 mutation influences age at menarche and to investigate whether or not there is an association between age at menarche and the risk of breast cancer in BRCA1 or BRCA2 mutation carriers. The presence of a deleterious BRCA1 or BRCA2 mutation did not appear to influence a woman's age at menarche. A matched case-control study was conducted on 1311 pairs of women who have been identified to be carriers of a deleterious mutation in either the BRCA1 (n = 945 pairs) or the BRCA2 gene (n = 366 pairs). Information about age at menarche was derived from a questionnaire routinely administered to carriers of a mutation in either gene. Among women who carried a deleterious BRCA1 mutation, age at menarche was inversely associated with the risk of breast cancer (p trend = 0.0002). This association was not observed among BRCA2 mutation carriers (p trend = 0.49). Compared with BRCA1 carriers whose age at menarche was < or =11 years, women with a menarcheal age between 14 and 15 years old had a 54% reduction in risk (OR = 0.46; 95% CI 0.30-0.69). This study implicates early age at menarche as a determinant of breast cancer among women with a BRCA1 mutation.

Adolescent↗

PubMed2005

The risk of ovarian cancer after breast cancer in BRCA1 and BRCA2 carriers.

OBJECTIVE: To estimate the risk of ovarian cancer after a primary diagnosis of breast cancer among women with a BRCA1 or BRCA2 mutation and to identify host and treatment-related factors that might modify the risk. PATIENTS AND METHODS: Patients were 491 women with stage I or stage II breast cancer, diagnosed from 1975 to 2000 and for whom a BRCA1 or BRCA2 mutation had been identified. Patients were followed from the initial diagnosis of breast cancer until either ovarian cancer, prophylactic oophorectomy, death, or 2002. The medical treatment records and pathology documents were reviewed. Information that was abstracted from the medical charts included date of breast cancer diagnosis, stage of disease, use of chemotherapy, use of radiation therapy, usage of tamoxifen, oophorectomy, recurrence, second malignancy, and vital status. RESULTS: The 10-year actuarial risk of ovarian cancer after breast cancer was 12.7% for BRCA1 carriers and 6.8% for BRCA2 carriers (P = 0.03). The use of tamoxifen (OR = 1.79; P = 0.16) and chemotherapy (OR = 0.59; P = 0.15) did not significantly impact on the risk of subsequent ovarian cancer. Twenty-five percent of the deaths in women with stage I breast cancer were due to a subsequent ovarian cancer. CONCLUSIONS: The high incidence of ovarian cancer suggests that oophorectomy should be recommended in female BRCA1 and BRCA2 mutation carriers with a diagnosis of breast cancer, especially those with stage I disease. Breast cancer systemic therapy did not significantly alter the risk of ovarian cancer.

Adult↗

PubMed2005

Family characteristics and smoking among urban and rural adolescents living in China.

BACKGROUND: Adolescent smoking is a public health concern in China. Although the family is an important social influence in China, few associations among family characteristics and adolescent smoking have been examined using Chinese samples. METHODS: Survey data on psychosocial variables and smoking were collected from a sample of 3629 7th grade adolescents (46% female; 54% male; mean age 12.7 years) in Wuhan, China. For adolescents, past 30-day smoking, family relationships, parents' negative sanctioning of smoking, parents' agreement with smoking, and parents' smoking behaviors are assessed. To account for the clustered data structure, hierarchical logistic regression analyses controlling for demographics (urbanization, age) examined the independent and multivariate effects of family characteristics for each gender. RESULTS: Girls are less likely than boys to report smoking and are more likely to report positive family relationships, and having parents with negative attitudes toward them smoking. Positive family relationships and age were strongly associated with smoking for both genders. No significant differences exist by gender. CONCLUSION: These findings suggest that the quality of family relationships are important for adolescent female and male smoking in China.

Adolescent↗