Intracellular taurine deficiency impairs cardiac contractility in rainbow trout (Oncorhynchus mykiss) without affecting aerobic performance

Taurine is a non-proteinogenic sulfonic acid found in high concentrations inside vertebrate cardiomyocytes and its movement across the sarcolemmal membrane is critical for cell volume regulation. Taurine deficiency is rare in mammals, where it impairs cardiac contractility and leads to congestive heart failure. In fish, cardiac taurine levels vary substantially between species and can decrease by up to 60% in response to environmental change but its contribution to cardiac function is understudied. We addressed this gap in knowledge by generating a taurine-deficient rainbow trout (Oncorhynchus mykiss) model using a feed enriched with 3% β-alanine to inhibit cellular taurine uptake. Cardiac taurine was reduced by 17% after 4 weeks with no effect on growth or condition factor. Taurine deficiency did not affect routine or maximum rates of O₂ consumption, aerobic scope, or critical swimming speed in whole animals but cardiac contractility was significantly impaired. In isometrically contracting ventricular strip preparations, the force-frequency and extracellular Ca²⁺-sensitivity relationships were both shifted downward and maximum pacing frequency was significantly lower in β-alanine fed trout. Cardiac taurine deficiency reduces sarcoplasmic reticular Ca²⁺-ATPase activity in mammals and our results are consistent with such an effect in rainbow trout. Our data indicate that intracellular taurine contributes to the regulation of cardiac contractility in rainbow trout. Aerobic performance was unaffected in β-alanine-fed animals, but further study is needed to determine if more significant natural reductions in taurine may constrain performance under certain environmental conditions.

Polyvinylpyrolidone-functionalized silver nanoparticles do not affect aerobic performance or fractional rates of protein synthesis in rainbow trout (Oncorhynchus mykiss)

Aerobic performance in fish is linked to individual and population fitness and can be impacted by anthropogenic contaminants. Exposure to some engineered nanomaterials, including silver nanoparticles (nAg), reduces rates of oxygen consumption in some fish species, but the underlying mechanisms remain unclear. In addition, their effects on swim performance have not been studied. Our aim was to quantify the impact of exposure to functionalized nAg on aerobic scope and swim performance in rainbow trout (Oncorhychus mykiss) and to characterize the contribution of changing rates of protein synthesis to these physiological endpoints. Fish were exposed for 48 h to 5 nm polyvinylpyrolidone-functionalized nAg (nAgPVP; 100 μg L^-1) or 0.22 μg L^-1 Ag⁺ (as AgNO₃), which was the measured quantity of Ag released from the nAgPVP over that time period. Aerobic scope, critical swimming speed (U_crit), and fractional rates of protein synthesis (K_s), were then assessed, along with indicators of osmoregulation and cardiotoxicity. Neither nAgPVP, nor Ag⁺ exposure significantly altered aerobic scope, its component parts, or swim performance. K_s was similarly unaffected in 8 tissue types, though it tended to be lower in liver of nAgPVP treated fish. The treatments tended to decrease gill Na⁺/K⁺-ATPase activity, but effects were not significant. The latter results suggest that a longer or more concentrated nAgPVP exposure may induce significant effects. Although this same formulation of nAgPVP is bioactive in other fish, it had no effects on rainbow trout under the conditions tested. Such findings on common model animals like trout may thus misrepresent the safety of nAg to more sensitive species.

Assessment of quality of life in people living with HIV in Georgia

The purpose of our study was to assess quality of life (QoL) among Georgian HIV-infected individuals and to examine factors associated with QoL. Our cross-sectional study sample consisted of 201 HIV-infected adult outpatients recruited at the National AIDS Center in Tbilisi, Georgia. WHOQOL-HIV-BREF was used to measure QoL. Data about other variables of interest were obtained from medical records. Modified Poisson regression with robust variance estimates was performed to create a predictive model of factors that influenced QoL. The study results showed the following factors as predictors of good general QoL: antiretroviral (ARV) treatment (prevalence ratio (PR)=2.87 (95% CI: 1.45, 5.67)); higher education level (PR = 1.51 (95% CI: 1.05, 2.17)); CD4 cells ≥200 cells/mm³ (PR = 1.83 (95% CI: 1.13, 2.94)); and age ≥40 years (PR = 1.60 (95% CI: 1.09, 2.36)). However, all factors examined were associated with at least one QoL domain. Our study suggests that HIV-infected individuals younger than 40 years and those with lower education level are more likely to have poorer QoL, while those receiving ARV treatment tend to have better QoL. This highlights the importance of educational interventions and ARV treatment in HIV patients. Future research should seek to implement additional evidence-based actions to improve QoL in this population.

The association between selenium and other micronutrients and thyroid cancer incidence in the NIH-AARP Diet and Health Study

BACKGROUND

Selenium is an essential trace element that is important for thyroid hormone metabolism and has antioxidant properties which protect the thyroid gland from oxidative stress. The association of selenium, as well as intake of other micronutrients, with thyroid cancer is unclear.

METHODS

We evaluated associations of dietary selenium, beta-carotene, calcium, vitamin D, vitamin C, vitamin E, folate, magnesium, and zinc intake with thyroid cancer risk in the National Institutes of Health - American Association of Retired Persons Diet and Health Study, a large prospective cohort of 566,398 men and women aged 50-71 years in 1995-1996. Multivariable-adjusted Cox proportional hazards regression was used to examine associations between dietary intake of micronutrients, assessed using a food frequency questionnaire, and thyroid cancer cases, ascertained by linkage to state cancer registries and the National Death Index.

RESULTS

With the exception of vitamin C, which was associated with an increased risk of thyroid cancer (HR(Q5 vs Q1), 1.34; 95% CI, 1.02-1.76; P(trend), <0.01), we observed no evidence of an association between quintile of selenium (HR(Q5 vs Q1), 1.23; 95% CI, 0.92-1.65; P(trend), 0.26) or other micronutrient intake and thyroid cancer.

CONCLUSION

Our study does not suggest strong evidence for an association between dietary intake of selenium or other micronutrients and thyroid cancer risk. More studies are needed to clarify the role of selenium and other micronutrients in thyroid carcinogenesis.

Randomization to screening for prostate, lung, colorectal and ovarian cancers and thyroid cancer incidence in two large cancer screening trials

Background

Thyroid cancer incidence has increased significantly over the past three decades due, in part, to incidental detection. We examined the association between randomization to screening for lung, prostate, colorectal and/or ovarian cancers and thyroid cancer incidence in two large prospective randomized screening trials.

Methods

We assessed the association between randomization to low-dose helical CT scan versus chest x-ray for lung cancer screening and risk of thyroid cancer in the National Lung Screening Trial (NLST). In the Prostate Lung Colorectal and Ovarian Cancer Screening Trial (PLCO), we assessed the association between randomization to regular screening for said cancers versus usual medical care and thyroid cancer risk. Over a median 6 and 11 years of follow-up in NLST and PLCO, respectively, we identified 60 incident and 234 incident thyroid cancer cases. Cox proportional hazards regression was used to calculate the cause specific hazard ratios (HR) and 95% confidence intervals (CI) for thyroid cancer.

Results

In NLST, randomization to lung CT scan was associated with a non-significant increase in thyroid cancer risk (HR  = 1.61; 95% CI: 0.96–2.71). This association was stronger during the first 3 years of follow-up, during which participants were actively screened (HR  = 2.19; 95% CI: 1.07–4.47), but not subsequently (HR  = 1.08; 95% CI: 0.49–2.37). In PLCO, randomization to cancer screening compared with usual care was associated with a significant decrease in thyroid cancer risk for men (HR  = 0.61; 95% CI: 0.49–0.95) but not women (HR  = 0.91; 95% CI: 0.66–1.26). Similar results were observed when restricting to papillary thyroid cancer in both NLST and PLCO.

Conclusion

Our study suggests that certain medical encounters, such as those using low-dose helical CT scan for lung cancer screening, may increase the detection of incidental thyroid cancer.

PTSD diagnostic validity in Veterans Affairs electronic records of Iraq and Afghanistan veterans

OBJECTIVE

Administrative planning and policy decisions frequently rely on diagnostic data extracted from large electronic databases. However, the accuracy of this diagnostic information is uncertain. The present study examined the degree to which various diagnoses of posttraumatic stress disorder (PTSD) within Department of Veterans Affairs (VA) electronic databases were concordant with PTSD diagnostic status determined by standardized diagnostic interview.

METHOD

We interviewed 1,649 veterans of the Iraq and Afghanistan wars using the PTSD Module of the Structured Clinical Interview for DSM-IV (SCID). Participants also completed other interview-based and self-report measures of psychopathology and provided consent to access their electronic medical records (EMRs).

RESULTS

Concordance between database diagnosis and SCID diagnosis was 72.3% for current PTSD and 79.4% for lifetime PTSD. We observed associations between concordance status and combat exposure, PTSD symptom presentation, comorbid anxiety and depression, and psychosocial impairment. Veterans with false-negative PTSD diagnoses in the EMR were more likely to report lower levels of combat exposure, panic, and PTSD avoidance symptoms. Veterans with false-positive PTSD diagnoses in the EMR were more likely to report treatment seeking for emotional problems and less overall functional impairment.

CONCLUSIONS

Although the majority of participants were concordant for PTSD status, over 25% of EMR diagnoses differed from those obtained in the diagnostic interview, with varying proportions of false positives and false negatives. Overall, those individuals with the most and least severe symptom presentations in the diagnostic interview were more likely to be accurately classified.

Sex steroid hormone levels and body composition in men

BACKGROUND

Previous studies indicate that testosterone (T) is positively correlated with lean mass and inversely correlated with fat mass in men; however, the directionality of these associations, as well as the association with other hormones including estradiol (E2) and SHBG, is unclear.

METHODS

We examined cross-sectional and longitudinal associations of E2, T, SHBG, and E2/T ratio with body composition among men ages 30 to 79 in the Boston Area Community Health/Bone Survey. Total, trunk, and appendicular lean and fat mass were measured by dual-energy x-ray absorptiometry at baseline, and weight and waist/hip circumference were measured at baseline and follow-up. Partial Pearson correlation coefficients were used to estimate the linear relationship between each body composition measure and log-transformed hormone variable.

RESULTS

In cross-sectional analyses of 821 men, T, calculated free T, and SHBG were inversely correlated with fat mass, weight, body mass index, waist/hip circumference, and waist-to-hip ratio, with multivariable-adjusted correlations ranging from -0.13 to -0.37. Calculated free E2 was positively correlated with percentage total (r = .13) and trunk (r = .15) fat mass, and E2/T was positively correlated with all measures examined (r = .13-.40). There were no significant multivariable-adjusted longitudinal associations between baseline hormone levels and change in weight, body mass index, waist/hip circumference, or waist-to-hip ratio after an average follow-up of 4.8 years.

CONCLUSIONS

We observed significant cross-sectional associations between hormone levels, including E2, T, and E2/T, and body composition measures in men. Longitudinal analyses showing no influence of baseline hormone levels on change in anthropometric measures imply that body composition affects hormone levels and not the reverse.

Posttraumatic stress disorder in veterans and military personnel: epidemiology, screening, and case recognition

Posttraumatic stress disorder (PTSD) is a psychiatric disorder that affects 7-8% of the general U.S. population at some point during their lifetime; however, the prevalence is much higher among certain subgroups, including active duty military personnel and veterans. In this article, we review the empirical literature on the epidemiology and screening of PTSD in military and veteran populations, including the availability of sensitive and reliable screening tools. Although estimates vary across studies, evidence suggests that the prevalence of PTSD in deployed U.S. military personnel may be as high as 14-16%. Prior studies have identified trauma characteristics and pre- and posttrauma factors that increase risk of PTSD among veterans and military personnel. This information may help to inform prevention and screening efforts, as screening programs could be targeted to high-risk populations. Large-scale screening efforts have recently been implemented by the U.S. Departments of Defense and Veterans Affairs. Given the prevalence and potential consequences of PTSD among veterans and active duty military personnel, development and continued evaluation of effective screening methods is an important public health need.

Abstract 77: Analgesic use in relation to sex hormone and prolactin concentrations in premenopausal women

The use of common analgesics, such as aspirin, non-aspirin NSAIDs and acetaminophen, may be associated with the risk of several hormone-related cancers, possibly via effects on sex hormone and prolactin concentrations. Therefore, we assessed the cross-sectional relationship between analgesic (aspirin, non-aspirin NSAIDS, and acetaminophen) use and sex hormone and prolactin concentrations among 2,034 premenopausal women, 32 to 54 years old, from the Nurses' Health Study II. Approximately 84% of women provided timed luteal and follicular blood samples; the remainder provided a single untimed sample. After adjustment for age, BMI, parity, and other potential confounders, acetaminophen use was inversely associated with prolactin levels (ptrend= 0.04). Compared to non-users, prolactin concentrations were 11.8% lower among women who reported using acetaminophen at least 2 times per week (p&lt;0.01). Similarly, acetaminophen was inversely associated with free testosterone, when comparing use at least 2 times per week to non-users (7.1% lower, p = 0.04; ptrend= 0.04). Use of non-aspirin NSAIDs was positively associated with follicular free estradiol, with 13.5% higher levels in women who reported use 4 or more days per week as compared to non-users (p = 0.04; ptrend= 0.11); results for free follicular estradiol were similar (13.2% higher, p = 0.06; ptrend= 0.11) though not statistically significant. There were no clear associations observed between analgesic use and luteal estradiol, estrone, estrone sulfate, DHEA, DHEAS, androstenedione, and estrogen/androgen ratios. After adjustment for multiple comparisons, none of the associations were statistically significant. In conclusion, our study provides modest evidence for an association of acetaminophen use with prolactin and free testosterone concentrations in premenopausal women, and the suggestion of an association between non-aspirin NSAIDs and follicular free estradiol among those with frequent use.

Citation Format: Scott R. Bauer, Renee T. Fortner, Margaret A. Gates, Heather Eliassen, Susan E. Hankinson, Shelley S. Tworoger. Analgesic use in relation to sex hormone and prolactin concentrations in premenopausal women. [abstract]. In: Proceedings of the AACR Special Conference on Post-GWAS Horizons in Molecular Epidemiology: Digging Deeper into the Environment; 2012 Nov 11-14; Hollywood, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(11 Suppl):Abstract nr 77.

ABO blood group and risk of epithelial ovarian cancer within the Ovarian Cancer Association Consortium

PURPOSE

Previous studies have examined the association between ABO blood group and ovarian cancer risk, with inconclusive results.

METHODS

In eight studies participating in the Ovarian Cancer Association Consortium, we determined ABO blood groups and diplotypes by genotyping 3 SNPs in the ABO locus. Odds ratios and 95 % confidence intervals were calculated in each study using logistic regression; individual study results were combined using random effects meta-analysis.

RESULTS

Compared to blood group O, the A blood group was associated with a modestly increased ovarian cancer risk: (OR: 1.09; 95 % CI: 1.01-1.18; p = 0.03). In diplotype analysis, the AO, but not the AA diplotype, was associated with increased risk (AO: OR: 1.11; 95 % CI: 1.01-1.22; p = 0.03; AA: OR: 1.03; 95 % CI: 0.87-1.21; p = 0.76). Neither AB nor the B blood groups were associated with risk. Results were similar across ovarian cancer histologic subtypes.

CONCLUSION

Consistent with most previous reports, the A blood type was associated modestly with increased ovarian cancer risk in this large analysis of multiple studies of ovarian cancer. Future studies investigating potential biologic mechanisms are warranted.

Associations of commonly used medications with urinary incontinence in a community based sample

PURPOSE

We examined the association between the use of medications and the prevalence of urinary incontinence in gender specific analyses of a community based, representative sample.

MATERIALS AND METHODS

A population based epidemiological study was conducted of 5,503 men and women 30 to 79 years old residing in Boston, Massachusetts (baseline data collected from 2002 to 2005). Urological symptoms were ascertained in a 2-hour, in person interview. Urinary incontinence was defined as urine leakage occurring weekly or more often during the last year. Medications used in the last month were considered current use. Associations of 20+ medications and prevalent urinary incontinence were examined using multivariate logistic regression (ORs and 95% CIs) with adjustments for known urinary incontinence risk factors.

RESULTS

The prevalence of urinary incontinence in the analysis sample was 9.0% in women and 4.6% in men. For women the prevalence was highest among users of certain antihistamines (28.4%) and angiotensin II receptor blockers (22.9%). For men the prevalence was highest among angiotensin II receptor blocker (22.2%) and loop diuretic (19.1%) users. After final multivariate adjustment there were significant positive associations for certain antihistamines, beta receptor agonists, angiotensin II receptor blockers and estrogens with urinary incontinence in women (all ORs greater than 1.7), and a borderline significant association for anticonvulsants (OR 1.75; 95% CI 1.00, 3.07). Among men only anticonvulsants were associated with urinary incontinence after final adjustments (OR 2.50; 95% CI 1.24, 5.03), although angiotensin II receptor blockers showed an adjusted association of borderline significance (OR 2.21; 95% CI 0.96, 5.10).

CONCLUSIONS

Although a cross-sectional analysis cannot determine causality, our analysis suggests certain medications should be further examined in longitudinal analyses of risk to determine their influence on urological symptoms.

Project VALOR: design and methods of a longitudinal registry of post-traumatic stress disorder (PTSD) in combat-exposed veterans in the Afghanistan and Iraqi military theaters of operations

Few studies have investigated the natural history of post-traumatic stress disorder (PTSD). Project VALOR (Veterans' After-discharge Longitudinal Registry) was designed as a longitudinal patient registry assessing the course of combat-related PTSD among 1600 male and female Veterans who served in Operation Enduring Freedom (OEF) in Afghanistan or Operation Iraqi Freedom (OIF). Aims of the study include investigating patterns and predictors of progression or remission of PTSD and treatment utilization. The study design was based on recommendations from the Agency for Healthcare Quality and Research for longitudinal disease registries and used a pre-specified theoretical model to select the measurement domains for data collection and interpretation of forthcoming results. The registry will include 1200 male and female Veterans with a recent diagnosis of PTSD in the Department of Veteran Affairs (VA) electronic medical record and a comparison group of 400 Veterans without a medical record-based PTSD diagnosis, to also allow for case-control analyses. Data are collected from administrative databases, electronic medical records, a self-administered questionnaire, and a semi-structured diagnostic telephone interview. Project VALOR is a unique and timely registry study that will evaluate the clinical course of PTSD, psychosocial correlates, and health outcomes in a carefully selected cohort of returning OEF/OIF Veterans.

ABO blood group and breast cancer incidence and survival

ABO blood type has been associated with risk and survival for several malignancies; however, data for an association with breast cancer are inconsistent. Our study population consisted of Nurses' Health Study participants with self-reported serologic blood type and/or ABO genotype. Using Cox proportional hazards regression, we examined the association between serologic blood type and incident breast cancer among 67,697 women, including 3,107 cases. In addition, we examined the association with ABO genotype in a nested case-control study of 1,138 invasive breast cancer cases and 1,090 matched controls. Finally, we evaluated the association between serologic blood type and survival among 2,036 participants with breast cancer. No clear association was seen between serologic blood type or ABO genotype and risk of total breast cancer, invasive breast cancer or breast cancer subtypes. Compared to women with blood type O, the age-adjusted incidence rate ratios for serologic blood type and total breast cancer were 1.06 (95% CI, 0.98-1.15) for type A, 1.06 (95% CI, 0.93-1.22) for AB and 1.08 (95% CI, 0.96-1.20) for B. In genetic analyses, odds ratios for invasive breast cancer were 1.05 (95% CI, 0.87-1.27) for A/O, 1.21 (95% CI, 0.86-1.69) for A/A, 0.84 (95% CI, 0.56-1.26) for A/B, 0.84 (95% CI, 0.63-1.13) for B/O and 1.17 (95% CI, 0.35-3.86) for B/B, compared to O/O. No significant association was noted between blood type and overall or breast cancer-specific mortality. Our results suggest no association between ABO blood group and breast cancer risk or survival.

Non steroidal anti-inflammatory drug use and levels of oestrogens and androgens in men

OBJECTIVE

Studies suggest that regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) may lower oestrogen levels in women. However, no large, population-based studies have assessed NSAID/hormone associations in men. Our objective was to examine the association between use of prescription and over-the-counter NSAIDs, and levels of oestrogens and androgens in men.

DESIGN

The Boston Area Community Health Survey, an observational survey with initial data collection in 2002-2005.

PATIENTS

A total of 1766 men who provided a blood sample and data on recent analgesic use.

MEASUREMENTS

Adjusted geometric mean levels of androgens, oestrogens, SHBG, LH and FSH for each category of NSAID use and the per cent difference in hormone levels for users vs nonusers.

RESULTS

There was no significant association between prescription/over-the-counter NSAID use and any hormone examined after adjustment for potential confounders. For example, geometric mean testosterone levels were 13·8, 13·6 and 14·2 nM in nonusers, prescription users and over-the-counter NSAID users, respectively; the corresponding levels for estradiol were 80·3, 70·4 and 79·9 pM. In stratified analyses, however, prescription NSAID use was associated with lower testosterone, estradiol and estrone levels in obese men and lower testosterone and dehydroepiandrosterone sulphate levels in inactive men.

CONCLUSIONS

While overall these data do not provide strong support for an association between NSAID use and hormone levels in men, prescription NSAIDs may decrease levels of certain oestrogens and androgens in obese and inactive men.

Nonsteroidal antiinflammatory drug use and lower urinary tract symptoms: results from the Boston area community health survey

There is evidence for a role of inflammation in the etiology of lower urinary tract symptoms (LUTS), raising the possibility that use of nonsteroidal antiinflammatory drugs (NSAIDs) may inhibit the development or progression of LUTS. The authors examined the association between use of prescription and over-the-counter NSAIDs and LUTS among 1,974 men and 2,661 women in the Boston Area Community Health Survey (2002-2005). Multivariable-adjusted logistic regression was used to estimate odds ratios and 95% confidence intervals for LUTS, voiding symptoms, storage symptoms, and nocturia. There was no clear association between use of prescription or over-the-counter NSAIDs (compared with no NSAID use) and overall LUTS, voiding symptoms, or nocturia in men or women. However, over-the-counter NSAID use was positively associated with storage symptoms in women (odds ratio = 1.37, 95% confidence interval: 1.03, 1.83), and there was a positive association between over-the-counter NSAID use and overall LUTS among women with a history of arthritis (odds ratio = 2.09, 95% confidence interval: 1.20, 3.64). These results do not provide strong support for an association between NSAIDs and LUTS. However, the associations between over-the-counter NSAID use and certain urologic symptoms, particularly among women with arthritis, and the potential mechanisms involved should be evaluated in future studies.

Risk factors for ductal and lobular breast cancer: results from the nurses' health study

Introduction

Ductal and lobular carcinomas are the two most common types of invasive breast cancer. Whether well-established risk factors are differentially associated with risk on the basis of histologic subtype is not clear. We prospectively investigated the association between a number of hormonal and nonhormonal exposures and risk defined by histologic subtype among 4,655 ductal and 659 lobular cases of postmenopausal breast cancer from the Nurses' Health Study.

Methods

Multivariate Cox proportional hazards regression stratified by histologic subtype and time period was used to examine the association between risk factors and the incidence of ductal and lobular subtypes. For each exposure, we calculated the P value for heterogeneity using a likelihood ratio test comparing models with separate estimates for the two subtypes versus a single estimate across subtypes.

Results

The associations with age at menarche (P-heterogeneity (het) = 0.03), age at first birth (P-het < 0.001) and postmenopausal hormone use (P-het < 0.001) were more strongly associated with lobular cancers. The associations with age, nulliparity, parity, age at menopause, type of menopause, alcohol intake, adult body mass index (BMI), BMI at age 18, family history of breast cancer and personal history of benign breast disease did not vary by subtype (P-het ≥ 0.08). Results were similar when we restricted the analyses to estrogen receptor-positive and progesterone receptor-positive tumors.

Conclusions

These data indicate that breast cancer is a heterogeneous disease, and the differential association with a number of risk factors is suggestive of etiologically distinct tumors. Epidemiological analyses should continue to take into account a modifying role of histology.

MTHFR polymorphisms in relation to ovarian cancer risk

OBJECTIVE

Folate has been hypothesized to influence carcinogenesis due to its dual role in DNA methylation, which regulates gene expression, and synthesis of purine and thymidylate, which is vital for DNA repair. Thus, we examined ovarian cancer risk in relation to two functional polymorphisms (C677T and A1298C) in the MTHFR gene.

METHODS

We genotyped the C677T (rs1801133) and A1298C (rs1801131) MTHFR polymorphisms in 1642 cases and 2068 controls from three studies, the New England Case Control Study (NEC), Nurses' Health Study (NHS), and Mayo Clinic Ovarian Cancer Case Control Study (MAY).

RESULTS

Overall, we observed no association between either SNP and ovarian cancer risk (pooled C677T p(trend)=0.59 and A1298C p(trend)=0.58). Significant associations (C677T p(trend)=0.001, A1298C p(trend)=0.02) between these MTHFR SNPs and serous ovarian cancer risk were observed in the NEC study, but were not replicated in the NHS and MAY studies.

CONCLUSIONS

MTHFR SNPs C677T and A1298C are not associated with ovarian cancer risk. Our results highlight the need for validation of genetic findings.

Interaction between use of non-steroidal anti-inflammatory drugs and selected genetic polymorphisms in ovarian cancer risk

Inflammation and non-steroidal anti-inflammatory agents (NSAIDs) may play important role in ovarian cancer. However, epidemiologic data are inconsistent, possibly reflecting inter-individual genetic differences affecting the metabolism of NSAIDs. We examined whether common polymorphisms affecting the metabolism of NSAIDs modify the association between NSAIDs and ovarian cancer risk. We genotyped 1,353 DNA samples from women who developed ovarian cancer and 1,823 samples from matched controls participating in the New England Case-Control study and the Nurses' Health Studies. Conditional logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs) associated with regular use of NSAIDs and with relevant polymorphisms on ovarian cancer risk. Multivariable unconditional logistic regression estimated the association of NSAID use across stratum of each genotype. Regular use of NSAIDs was not associated with ovarian cancer risk. Multivariable OR (95% CI) associated with use NSAIDs was 0.85 (95% CI: 0.71-1.02). Associations between NSAID use and ovarian cancer risk did not differ significantly across strata of genotypes. None of the studied polymorphisms was associated with ovarian cancer risk. The multivariable ORs (95% CI) associated with CYP2C9 and UGT1A6 variant genotypes were 0.99 (0.90-1.08) and 0.93 (0.82-1.05), respectively. The multivariable ORs (95% CI) associated with PPAR-γ, COX-2 -765G>C, and COX-2 Ex10+837T>C polymorphisms were 1.02 (0.87-1.20), 0.87 (0.75-1.00), and 0.97 (0.87-1.09), respectively. In this relatively large study, we found no convincing evidence supporting an association between NSAIDs use and ovarian cancer risk. Furthermore, data did not suggest interaction between selected polymorphisms and use of NSAIDs in relation to ovarian cancer risk.

Genetic variation in TYMS in the one-carbon transfer pathway is associated with ovarian carcinoma types in the Ovarian Cancer Association Consortium

BACKGROUND

We previously reported the risks of ovarian carcinoma for common polymorphisms in one-carbon transfer genes. We sought to replicate associations for DPYD rs1801265, DNMT3A rs13420827, MTHFD1 rs1950902, MTHFS rs17284990, and TYMS rs495139 with risk of ovarian carcinoma overall and to use the large sample of assembled cases to investigate associations by histologic type.

METHODS

Associations were evaluated in the Ovarian Cancer Association Consortium, including 16 studies of 5,593 epithelial ovarian carcinoma cases and 9,962 controls of white non-Hispanic origin. Odds ratios (OR) and 95% confidence intervals (CI) were adjusted for age and study site.

RESULTS

The five polymorphisms were not associated with ovarian carcinoma overall (P(trend) > 0.13); however, associations for the minor allele at TYMS rs495139 were observed for carcinomas of mucinous type (OR, 1.19; 95% CI, 1.03-1.39; P = 0.02), clear cell type (OR, 0.86; 95% CI, 0.75-0.99; P = 0.04), and endometrioid type (OR, 0.90; 95% CI, 0.81-0.99; P = 0.04; P(heterogeneity) = 0.001). Restriction to low-grade mucinous carcinomas further strengthened the association for the mucinous type (OR, 1.32; 95% CI, 1.07-1.62; P = 0.01). TYMS rs495139 was not associated with serous type (OR, 1.06; 95% CI, 1.00-1.13; P = 0.05).

CONCLUSIONS

TYMS rs495139 may be associated with a differential risk of ovarian carcinoma types, indicating the importance of accurate histopathologic classification.

IMPACT

Biomarkers that distinguish ovarian carcinoma types are few, and TYMS rs495139 may provide a novel clue to type etiology.

Perineal use of talcum powder and endometrial cancer risk

BACKGROUND

Several studies have reported a positive association between perineal use of talcum powder among adult women and ovarian cancer risk. However, the relationship between talcum powder use and other gynecologic malignancies such as endometrial cancer has not been examined, and little information is available on nonhormonal risk factors for endometrial cancer.

METHODS

Perineal use of talcum powder was assessed in 1982 in the Nurses' Health Study. Approximately 40% of women who responded to the questions about perineal use of talcum powder reported ever use. Cox proportional hazards models were used to estimate the incidence rate ratio of endometrial cancer and 95% confidence interval (CI), adjusted for body mass index and other potential confounders. We evaluated the relationship among all women and stratified by menopausal status.

RESULTS

Our analysis included 66,028 women with 599 incident cases of invasive endometrial adenocarcinoma diagnosed between 1982 and 2004. Although no association was observed overall, the association varied by menopausal status (P interaction=0.02) and a positive association was observed among postmenopausal women; ever use of talcum powder was associated with a 21% increase in risk of endometrial cancer (95% CI, 1.02-1.44), whereas regular use (at least once a week) was associated with a 24% increase in risk (95% CI, 1.03-1.48). In addition, we observed a borderline increase in risk with increasing frequency of use (P trend=0.04).

CONCLUSIONS

Our results suggest that perineal talcum powder use increases the risk of endometrial cancer, particularly among postmenopausal women.

IMPACT

Future and larger studies are needed to confirm this association and investigate potential mechanisms.

Abstract 1830: Recreational physical activity and ovarian cancer incidence: An updated analysis of the Nurses’ Health Study cohorts

The results of previous studies of recreational physical activity and risk of epithelial ovarian cancer are mixed, with some studies supporting an inverse association and others, including several prospective studies, observing no association or a suggestive positive association with vigorous activity. Physical activity may decrease ovarian cancer risk by reducing circulating levels of estrogens, decreasing body fat and estrogen synthesis, or reducing the frequency of ovulation. However, plausible mechanisms also exist for a positive association, including possible ovulatory changes with regular vigorous activity, increased pituitary production of gonadotropins, or changes in progesterone or androgen concentrations. In an earlier analysis of the Nurses’ Health Study (NHS) with follow-up through 1996, there was no clear association between physical activity level and ovarian cancer incidence, but there was a suggestion of an increase in risk with frequent vigorous activity. We reanalyzed this association using 10 additional years of follow-up in the NHS and adding data from the younger Nurses’ Health Study II (NHSII) cohort. We calculated current and cumulative average physical activity in hours per week and metabolic equivalent task-hours (MET-hours) per week using data collected every 2-6 years beginning in 1986 (NHS) or 1989 (NHSII). We used Cox proportional hazards regression to model the age- and multivariable-adjusted incidence rate ratios of ovarian cancer for each category of physical activity, compared to the lowest category. Our analysis included 179,443 women with detailed physical activity data and 652 incident, confirmed cases diagnosed through 2006 (NHS) or 2007 (NHSII). There was no clear association between hours per week of current or cumulative average activity and ovarian cancer risk. However, there was evidence of a positive association between cumulative average MET-hours of total activity per week and risk of all epithelial cancers and the serous invasive subtype. The multivariable-adjusted incidence rate ratios and 95% confidence intervals for each MET-hour category, compared to &lt;2.5 MET-hours, were 1.27 (0.90, 1.80) for 2.5-&lt;5 MET-hours, 1.06 (0.77, 1.48) for 5-&lt;10 MET-hours, 1.17 (0.86, 1.60) for 10-&lt;20 MET-hours, 1.56 (1.13, 2.17) for 20-&lt;30 MET-hours, and 1.34 (0.96, 1.87) for ≥30 MET-hours. The corresponding estimates for serous invasive cancers were 1.42 (0.86, 2.35), 1.14 (0.71, 1.84), 1.49 (0.95, 2.32), 1.82 (1.14, 2.92), and 1.48 (0.92, 2.40). Our results do not support an inverse association between physical activity and ovarian cancer risk, and suggest a possible increase in risk with high levels of activity, particularly for the serous invasive subtype. Lagged analyses and analyses of specific types and intensities of activity are ongoing.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1830.

Analgesic use and sex steroid hormone concentrations in postmenopausal women

Prior epidemiologic studies suggest that regular use of analgesics may decrease risk of breast and ovarian cancer. We explored possible hormone-mediated mechanisms for these associations by examining the relationship between use of aspirin, nonaspirin nonsteroidal anti-inflammatory drugs (NSAID), and acetaminophen and sex steroid hormone concentrations among 740 postmenopausal women in the Nurses' Health Study. All women reported their analgesic use in 1988 or 1990 and provided a blood sample in 1989 to 1990. We calculated adjusted geometric mean estrogen and androgen levels for each category of analgesic use and calculated the P value for trend with increasing frequency of use. There was no association between days of use per month of aspirin, nonaspirin NSAIDs, or acetaminophen in 1990 and hormone levels (all P(trend) > or = 0.09). However, we observed significant inverse trends between the estimated number of aspirin tablets per month in 1988 and concentrations of estrone (P(trend) = 0.04) and estrone sulfate (P(trend) = 0.03). In analyses of total (aspirin and nonaspirin) NSAID use in 1990, women who used NSAIDs at least 15 days per month had significantly lower levels of estradiol compared with women with no NSAID use (P(trend) = 0.03). Frequency of use of all analgesics (aspirin, nonaspirin NSAIDs, and acetaminophen) in 1990 was inversely associated with concentrations of estradiol (P(trend) = 0.001), free estradiol (P(trend) = 0.01), estrone sulfate (P(trend) = 0.03), and the ratio of estradiol to testosterone (P(trend) = 0.04). Among postmenopausal women, regular users of aspirin and other analgesics may have lower estrogen levels than nonusers, which could contribute to a decreased risk of breast or ovarian cancer among analgesic users.

ABO blood group and incidence of epithelial ovarian cancer

Previous studies have observed an association between ABO blood group and risk of certain malignancies, including ovarian cancer; however, no prospective studies of the association with ovarian cancer risk are available. Using data from 49,153 women in the Nurses' Health Study, we examined the association between ABO blood group and incidence of epithelial ovarian cancer. Study participants reported their blood type and Rh factor in 1996, and 234 women were diagnosed with incident ovarian cancer during 10 years of follow-up. We used Cox proportional hazards regression to model the incidence rate ratios (RR) and 95% confidence intervals (CI) of ovarian cancer for each blood group category. Compared to women with blood group O, women with blood group AB or B had a nonsignificant 38% increase in ovarian cancer incidence (95% CI = 0.88-2.16 for blood group AB and 0.96-1.99 for blood group B), whereas blood group A was not associated with risk (RR = 0.95, 95% CI = 0.70-1.30). Combining blood groups AB and B, we observed a statistically significant positive association with presence versus absence of the B antigen overall (RR = 1.41, 95% CI = 1.06-1.88) and for the serous invasive subtype (RR = 1.53, 95% CI = 1.08-2.17). In this large, prospective cohort of women, presence of the B antigen was positively associated with ovarian cancer incidence, whereas blood group A was not associated with risk. Additional studies are needed to confirm this association and to explore the mechanisms through which blood group may influence ovarian cancer risk.

Abstract A126: Risk factors for epithelial ovarian cancer by tumor dominance, a surrogate for cell of origin

Ovarian tumors traditionally are thought to arise from the ovarian surface epithelium (OSE); however recent studies suggest that some tumors may originate in the distal fallopian tube. Differences in the risk factors for tumors of ovarian versus tubal origin may help to explain inconsistent associations observed across studies for some exposures. To determine cell of origin in cancer resections, it is necessary to conduct detailed sectioning of fallopian tubes and ovaries, which is impractical in large epidemiologic studies. However a prior study suggested that tumor dominance, determined from pathology reports, may be an acceptable surrogate for cell of origin, such that tumors arising in the OSE are more likely to involve only one ovary or to show one involved ovary exceeding the other in dimension by more than two-fold (DOM+), while tumors of tubal origin show symmetric ovarian involvement or an even distribution across the peritoneal cavity (DOM−). Therefore, to explore risk factor associations by cell of origin, we prospectively investigated the relationship of both reproductive/hormonal and non-reproductive exposures with risk of DOM+ versus DOM− tumors among 403 incident invasive cases of confirmed epithelial ovarian cancer from the Nurses' Health Study (NHS) and NHSII. Cox proportional hazards regression, stratified by dominance and time period, was used to examine the associations. For each exposure, we calculated the P-value for heterogeneity using a likelihood ratio test comparing models with separate estimates for the two subtypes versus a single estimate across subtypes. There were 281 DOM+ and 122 DOM− cases diagnosed between 1976 and 2006. In analyses of reproductive/hormonal exposures, there was no significant heterogeneity across the two subtypes for the associations with age, age at natural menopause, breastfeeding, parity, oral contraceptive use, estrogen use, and hysterectomy (P-heterogeneity ≥ 0.40). However, the association with tubal ligation was significantly stronger for DOM+ (RR=0.51; 95%CI=0.34–0.75) versus DOM− tumors (RR=0.95; 95%CI=0.58–1.56; P-heterogeneity=0.05). While associations with several non-reproductive exposures (e.g., BMI, physical activity, talc use) did not vary by subtype (P-heterogeneity ≥ 0.11), the association with family history of ovarian cancer was stronger for DOM− (RR=3.32; 95% CI=1.52–7.25) versus DOM+ tumors (RR=0.95; 95%CI=0.39–2.32; P-heterogeneity=0.04). The results were similar when we limited our analysis to 228 cases with serous invasive or poorly differentiated histology. Although limited by small case numbers, our results suggest that tubal ligation may be more strongly associated with tumors of ovarian origin, while family history of ovarian cancer primarily increases risk of tumors of tubal origin. Characterizing risk factor relationships by tumor dominance may elucidate how these exposures alter risk and help to improve prevention efforts.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A126.

Common genetic variation in IGF1, IGFBP1 and IGFBP3 and ovarian cancer risk

Insulin-like growth factor (IGF) 1 and its binding proteins foster cellular proliferation and inhibit apoptosis. In vitro studies show that IGF1 increases ovarian cell growth and invasive potential, suggesting a role for the IGF1 pathway in ovarian cancer etiology. We evaluated genetic variation in the IGF1, IGFBP1 and IGFBP3 genes in relation to ovarian cancer risk by genotyping 29 haplotype-tagging single nucleotide polymorphisms in 1173 cases and 1201 controls from the New England Case-Control (NECC) study and 296 cases and 854 controls from the Nurses' Health Study (NHS). The association of haplotypes and single nucleotide polymorphisms (SNPs) with ovarian cancer was estimated using unconditional (NECC) and conditional (NHS) logistic regression. Additionally, we evaluated the association of SNPs with IGF1, IGF-binding protein (IGFBP) 3 and IGFBP2 plasma levels (n = 380 NHS controls). Our data suggest a decreased risk for women carrying haplotype 2C of the IGF1 gene [odds ratios (ORs) = 0.82, 95% confidence intervals (CIs) = 0.69-0.98] and an increased risk for women carrying haplotype 1D (OR = 1.41, 95% CI = 1.03-1.94) or 2D (OR = 1.20, 95% CI = 1.01-1.41) in the binding proteins. When evaluated individually, three SNPs in the IGFBPs (rs10228265, rs4988515 and rs2270628) were associated with increased ovarian cancer risk, and several IGF1 (rs11111285, rs1996656 and rs1019731) and IGFBP3 (rs2270628, rs2854746 and rs2854744) SNPs were significantly associated with IGF1, IGFBP3 and IGFBP2 plasma levels. Some haplotypes and SNPs in the IGF pathway genes may be associated with ovarian cancer risk; however, these results need to be confirmed. Of particular interest was the IGFBP3 SNP rs2270628, which was associated with both increased IGF1 plasma levels and higher ovarian cancer risk.

Risk factors for epithelial ovarian cancer by histologic subtype

Previous epidemiologic studies suggest that the major histologic subtypes of epithelial ovarian cancer may have different risk factor profiles; however, no known prospective study has systematically examined differences in risk by subtype. The authors used Cox proportional hazards regression, stratified by histologic subtype and time period, to examine the association between ovarian cancer risk factors and incidence of serous invasive, endometrioid, and mucinous ovarian cancers in the US Nurses' Health Study (1976-2006) and Nurses' Health Study II (1989-2005). For each exposure, they calculated P-heterogeneity using a likelihood ratio test comparing models with separate estimates for the 3 subtypes versus a single estimate across subtypes. Analysis included 221,866 women and 721 cases with the histologies of interest (496 serous invasive, 139 endometrioid, 86 mucinous). In analyses of reproductive/hormonal exposures, the associations with age, duration of breastfeeding, age at natural menopause, and duration of estrogen use differed significantly by subtype (all P-heterogeneity < or =0.05). The associations with several nonreproductive exposures also appeared to vary by subtype, but only the association with smoking differed significantly (P-heterogeneity = 0.03). Results suggest that associations with several ovarian cancer risk factors vary by subtype, and these differences are consistent with known similarities between each major histologic subtype and its normal tissue counterpart.

Flavonoid intake and ovarian cancer risk in a population-based case-control study

Several recent studies have evaluated the association between dietary flavonoid intake and ovarian cancer risk, and all reported significant or suggestive inverse associations with certain flavonoids or flavonoid subclasses; however, most of these studies were small to moderate in size. We, therefore, examined this association in a large, population-based case-control study. We calculated intake of 5 common dietary flavonoids (myricetin, kaempferol, quercetin, luteolin, and apigenin), as well as total intake of these flavonoids, for 1,141 cases and 1,183 frequency-matched controls. We used unconditional logistic regression to estimate the relative risk (RR) of ovarian cancer for each quintile of flavonoid intake when compared with the lowest quintile. We did not observe an association between total flavonoid intake and ovarian cancer risk. The multivariable-adjusted RR for the highest versus lowest quintile of total flavonoid intake was 1.06 (95% confidence interval [CI] = 0.78-1.45). In analyses of each individual flavonoid, only intake of apigenin was associated with a borderline significant decrease in risk (RR, highest vs. lowest quintile = 0.79, 95% CI = 0.59-1.06; p-trend = 0.26), and this association was significant after adjustment for intake of the other 4 individual flavonoids (comparable RR = 0.72, 95% CI = 0.53-0.98; p-trend = 0.09). These results provide limited support for an association between flavonoid intake and ovarian cancer risk. However, given the findings of previous studies and the biologic plausibility of this association, additional studies are warranted.

Polymorphisms in the vitamin D receptor and risk of ovarian cancer in four studies

Prior studies have suggested that vitamin D may reduce ovarian cancer risk. Thus, we examined whether three single nucleotide polymorphisms (SNP) in the vitamin D receptor (VDR) gene (Fok1, Bsm1, Cdx2) were associated with risk of epithelial ovarian cancer in a retrospective case-control study (New England Case-Control study, NECC) and a nested case-control study of three prospective cohort studies: the Nurses' Health Study (NHS), NHSII, and the Women's Health Study. Data from the cohort studies were combined and analyzed using conditional logistic regression and pooled with the results from the NECC, which were analyzed using unconditional logistic regression, using a random effects model. We obtained genotype data for 1,473 cases and 2,006 controls. We observed a significant positive association between the number of Fok1 f alleles and ovarian cancer risk in the pooled analysis (P(trend) = 0.03). The odds ratio (OR) for the ff versus FF genotype was 1.26 [95% confidence interval (CI) = 1.01-1.57]. Neither the Bsm1 (P(trend) = 0.96) or Cdx2 (P(trend) = 0.13) SNPs were significantly associated with ovarian cancer risk. Among the prospective studies, the risk of ovarian cancer by plasma vitamin D levels did not clearly vary by any of the genotypes. For example, among women with the Fok1 FF genotype, the OR comparing plasma 25-hydroxyvitamin D >or=32 ng/mL versus <32 ng/mL was 0.66 (95% CI, 0.34-1.28), and among women with the Ff or ff genotype the OR was 0.71 (95% CI, 0.43-1.18). Our results of an association with the Fok1 VDR polymorphism further support a role of the vitamin D pathway in ovarian carcinogenesis.

Validation of tissue microarray technology in ovarian cancer: results from the Nurses' Health Study

BACKGROUND

Tissue microarrays (TMAs) allow high-throughput evaluation of protein expression from archived tissue samples. We identified characteristics specific to ovarian cancer that may influence TMA interpretation.

METHODS

TMAs were constructed using triplicate core samples from 174 epithelial ovarian cancers. Stains for p53, Ki-67, estrogen receptor-alpha, progesterone receptor, Her-2, WT-1, cytokeratin 7, and cytokeratin 20 were evaluated by intraclass correlation coefficients, Spearman correlation coefficients, the effect of sample age, and tumor histology on the ability to score the cores, and inter-rater reliability.

RESULTS

The interclass correlation coefficient and the mean Spearman correlation coefficients among 3 cores were > or = 0.91 and 0.87, respectively. Tissue age and tumor histology were not predictive of an inability to evaluate stains, but borderline tumors had a 2 to 4-fold increase in the risk of having uninterpretable cores over invasive tumors. There was moderate to substantial concordance between the two pathologists for estrogen receptor-alpha [Cohen's Kappa (kappa), 0.79] and Ki-67 (kappa, 0.52). The prevalence of positive staining cells by histologic type was comparable with previous studies.

CONCLUSION

TMA is a valid method for evaluating antigen expression in invasive ovarian cancer but should be used with caution for borderline tumors. We suggest several methods of quality control based on intercore comparisons and show that some antigens may be affected by age of the samples.

Ontogeny of substantia nigra dopamine neurons

Understanding the ontogeny of A9 dopamine (DA) neurons is critical not only to determining basic developmental events that facilitate the emergence of the substantia nigra pars compacta (SNc) but also to the extraction and de novo generation of DA neurons as a potential cell therapy for Parkinson's disease. Recent research has identified a precise window for DA cell birth (differentiation) in the ventral mesencephalon (VM) as well as a number of factors that may facilitate this process. However, application of these factors in vitro has had limited success in specifying a dopaminergic cell fate from undifferentiated cells, suggesting that other cell/molecular signals may as yet remain undiscovered. To resolve this, current work seeks to identify particularly potent and novel DA neuron differentiation factors within the developing VM specifically at the moment of ontogeny. Through such (past and present) studies, a catalog of proteins that play a pivotal role in the generation of nigral DA neurons during normal CNS development has begun to emerge. In the future, it will be crucial to continue to evaluate the critical developmental window where DA neuron ontogeny occurs, not only to facilitate our potential to protect these cells from degeneration in the adult brain but also to mimic the developmental environment in a way that enhances our ability to generate these cells anew either in vitro or in vivo. Here we review our present understanding of factors that are thought to be involved in the emergence of the A9 dopamine neuron group from the ventral mesencephalon.

Breast cancer susceptibility alleles and ovarian cancer risk in 2 study populations

Recent genome-wide scans identified several novel breast cancer risk alleles, including variants of the FGFR2, MAP3K1 and LSP1 genes, and a study of associations between these alleles and characteristics of breast cancer patients reported a borderline significant correlation between the number of FGFR2 minor alleles and family history of breast/ovarian cancer. Given these results and similarities in the etiology of breast and ovarian cancer, we examined the association between 7 novel breast cancer susceptibility alleles and epithelial ovarian cancer risk in 2 large study populations. Our analysis included 1,173 cases and 1,201 controls from a New England-based Case-Control study and 210 cases and 603 controls from the prospective Nurses' Health Study. We used logistic regression to estimate the odds ratio (OR) for individuals heterozygous or homozygous for the minor allele at each locus, compared to individuals with the wild-type genotype. We examined the associations separately in each population and, after testing for heterogeneity in the results, pooled the estimates using a random effects model. There was no clear association between these polymorphisms and ovarian cancer risk in either population. The pooled per allele OR for FGFR2 was 1.06 (95% confidence interval (CI)=0.95-1.18) for rs1219648 and 1.04 (95% CI=0.93-1.15) for rs2981582. We had more than 80% power to detect a log-additive OR of 1.16-1.18 per allele at the alpha=0.05 level in the pooled analysis. Our results do not provide strong support for an association between these breast cancer susceptibility alleles and epithelial ovarian cancer risk.

Talc use, variants of the GSTM1, GSTT1, and NAT2 genes, and risk of epithelial ovarian cancer

Epidemiologic evidence suggests a possible association between genital use of talcum powder and risk of epithelial ovarian cancer; however, the biological basis for this association is not clear. We analyzed interactions between talc use and genes in detoxification pathways [glutathione S-transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), and N-acetyltransferase 2 (NAT2)] to assess whether the talc/ovarian cancer association is modified by variants of genes potentially involved in the response to talc. Our analysis included 1,175 cases and 1,202 controls from a New England-based case-control study and 210 cases and 600 controls from the prospective Nurses' Health Study. We genotyped participants for the GSTM1 and GSTT1 gene deletions and three NAT2 polymorphisms. We used logistic regression to analyze the main effect of talc use, genotype, and gene-talc interactions in each population and pooled the estimates using a random-effects model. Regular talc use was associated with increased ovarian cancer risk in the combined study population (RR, 1.36; 95% CI, 1.14-1.63; P(trend) < 0.001). Independent of talc, the genes examined were not clearly associated with risk. However, the talc/ovarian cancer association varied by GSTT1 genotype and combined GSTM1/GSTT1 genotype. In the pooled analysis, the association with talc was stronger among women with the GSTT1-null genotype (P(interaction) = 0.03), particularly in combination with the GSTM1-present genotype (P(interaction) = 0.03). There was no clear evidence of an interaction with GSTM1 alone or NAT2. These results suggest that women with certain genetic variants may have a higher risk of ovarian cancer associated with genital talc use. Additional research is needed on these interactions and the underlying biological mechanisms.

Caffeine, alcohol, smoking, and the risk of incident epithelial ovarian cancer

BACKGROUND

Smoking, caffeine, and alcohol intake are all potentially modifiable factors that have an unclear association with ovarian cancer risk. Therefore, the associations between these exposures and ovarian cancer risk were prospectively examined among 110,454 women in the Nurses' Health Study (NHS) for the smoking analyses and 80,253 women for the dietary analyses.

METHODS

Women completed biennial questionnaires assessing ovarian cancer risk factors beginning in 1976, with food frequency questionnaires administered every 2 to 4 years starting in 1980. For the smoking analyses, 737 confirmed cases of epithelial ovarian cancer were identified and for the dietary aims, 507 cases were identified through June 1, 2004.

RESULTS

Compared with never-smokers, neither current nor past smoking was associated with ovarian cancer risk overall; however, both were associated with mucinous tumors (n = 69; rate ratio [RR], past = 2.02 [95% confidence interval (CI), 1.15-3.55]; RR, current = 2.22 [95% CI, 1.16-4.24]). A modest inverse association between caffeine intake and ovarian cancer risk was observed (RR, top vs bottom quintile = 0.80; 95% CI, 0.60-1.07 [P = .03]), which was strongest for women who had never used either oral contraceptives (RR = 0.65; 95% CI, 0.46-0.92 [P for heterogeneity = .02]) or postmenopausal hormones (RR = 0.57; 95% CI, 0.36-0.91 [P for heterogeneity = .13]). Alcohol was not associated with ovarian cancer risk.

CONCLUSIONS

The results of the current study suggest that cigarette smoking may only increase the risk for mucinous ovarian tumors, and alcohol intake was not associated with risk. However, an inverse association was observed between caffeine intake and ovarian cancer risk, particularly in women not using hormones; this finding merits further study.

A prospective study of dietary flavonoid intake and incidence of epithelial ovarian cancer

Flavonoids are antioxidant compounds found in plants, including fruits, vegetables and tea. No prior prospective studies have examined the association between intake of flavonoids in the flavonol and flavone subclasses and ovarian cancer risk. We analyzed the association between intake of 5 common dietary flavonoids and incidence of epithelial ovarian cancer among 66,940 women in the Nurses' Health Study. We calculated each participant's intake of myricetin, kaempferol, quercetin, luteolin and apigenin from dietary data collected at multiple time points, and used Cox proportional hazards regression to model the incidence rate ratio (RR) of ovarian cancer for each quintile of intake. Our analysis included 347 cases diagnosed between 1984 and 2002, and 950,347 person-years of follow-up. There was no clear association between total intake of the 5 flavonoids examined and incidence of ovarian cancer (RR = 0.75 for the highest versus lowest quintile, 95% confidence interval [CI] = 0.51-1.09). However, there was a significant 40% decrease in ovarian cancer incidence for the highest versus lowest quintile of kaempferol intake (RR = 0.60, 95% CI = 0.42-0.87; p-trend = 0.002), and a significant 34% decrease in incidence for the highest versus lowest quintile of luteolin intake (RR = 0.66, 95% CI = 0.49-0.91; p-trend = 0.01). There was evidence of an inverse association with consumption of tea (nonherbal) and broccoli, the primary contributors to kaempferol intake in our population. These data suggest that dietary intake of certain flavonoids may reduce ovarian cancer risk, although additional prospective studies are needed to further evaluate this association. If confirmed, these results would provide an important target for ovarian cancer prevention.

Improved survival of young donor age dopamine grafts in a rat model of Parkinson's disease

In an attempt to improve the survival of implanted dopamine cells, we have readdressed the optimal embryonic donor age for dopamine grafts. In a rat model of Parkinson's disease, animals with unilateral 6-hydroxydopamine lesions of the median forebrain bundle received dopamine-rich ventral mesencephalic grafts derived from embryos of crown to rump length 4, 6, 9, or 10.5 mm (estimated embryonic age (E) 11, E12, E13 and E14 days post-coitus, respectively). Grafts derived from 4 mm embryos survived poorly, with less than 1% of the implanted dopamine cells surviving. Grafts derived from 9 mm and 10.5 mm embryos were similar to those seen in previous experiments with survival rates of 8% and 7% respectively. The best survival was seen in the group that received 6 mm grafts, which were significantly larger than all other graft groups. Mean dopamine cell survival in the 6 mm group (E12) was 36%, an extremely high survival rate for primary, untreated ventral mesencephalic grafts applied as a single placement, and more than fivefold larger than the survival rate observed in the 10.5 mm (E14) group. As E12 ventral mesencephalic tissues contain few, if any, differentiated dopamine cells we conclude that the large numbers of dopamine cells seen in the 6 mm grafts must have differentiated post-implantation. We consider the in vivo conditions which allow this differentiation to occur, and the implications for the future of clinical trials based on dopamine cell replacement therapy.

Operating room nursing and lung cancer risk in a cohort of female registered nurses

OBJECTIVES

Smoke generated during laser surgery and electrocautery contains respiratory irritants and human carcinogens. Although laboratory and animal studies have demonstrated that this smoke has inflammatory and mutagenic potential, no population-based studies of the health effects of exposure to surgical smoke have been published. We examined the association between duration of employment as an operating room nurse, a proxy measure for surgical smoke exposure, and subsequent lung cancer risk.

METHODS

This study was conducted among 86 747 women in the Nurses' Health Study. Information on the duration of prior operating room employment was collected in 1984, and the women were followed for incident, confirmed lung cancer. Cox proportional hazards regression was used to model the incidence rate ratio of lung cancer for each exposure category using women with no prior operating room employment for comparison. All of the models were adjusted for age, smoking history, passive smoke exposure, fruit and vegetable consumption, and alpha carotene and lycopene intake.

RESULTS

A history of operating room employment was not associated with an increased rate of lung cancer in multivariable analyses [rate ratio (RR) 0.99, 95% confidence interval (95% CI) 0.86-1.15]. In fact, nurses in the highest exposure category, > or =15 years of operating room employment, had a significantly lower rate of lung cancer than nurses with no prior operating room employment (RR 0.58, 95% CI 0.37-0.91), possibly due to confounding by overall health status or residual confounding by smoking history.

CONCLUSIONS

Long-term exposure to surgical smoke, as measured by the duration of operating room employment, does not appear to increase the risk of lung cancer.

The influence of astrocytes on the development, regeneration and reconstruction of the nigrostriatal dopamine system

Over the past few decades astrocytes have emerged from being considered simple packing tissue in the brain to become major players in the development, survival and functioning of central nervous system (CNS) neurons. As the influence that astrocytes (and the various molecules they produce) have on the development of CNS neurons becomes more evident, it will be important to consider how this information can be exploited to bring about better protection, recovery and/or regeneration of circuits which are destroyed in the adult CNS due to trauma or com-mon neurodegenerative episodes. Although the characterisation of astrocytic responses to brain injuries, neurodegenerative disease, and cell transplantation are becoming more common, we still known little about how astrocytes influence the (re)growth or reconstruction of neural circuitry after the development period is ended, or indeed what is the overall impact of an astrocytic presence on the growth of neurons in the adult CNS. With the major hurdle of recognition of the importance astrocytes in the function and recovery of the adult CNS now cleared, a new chapter in the development of powerful new treatments for CNS disorders and injuries is now open. The following is a brief review of what we know about how astrocytes influence the growth and connectivity of the nigrostriatal circuit during development, and how these cells may affect efforts to reform this circuit after it s destruction/degeneration in the adult CNS (as commonly happens in Parkinson s disease). As we obtain more information on the specific influence of these cells in various developmental, traumatic and disease events we can expect to find better ways toward combating major disorders of the human CNS.

The homeobox genesvoxandventare redundant repressors of dorsal fates in zebrafish

Ventralizing transcriptional repressors in the Vox/Vent family have been proposed to be important regulators of dorsoventral patterning in the early embryo. While the zebrafish genes vox (vega1) and vent (vega2) both have ventralizing activity in overexpression assays, loss-of-function studies are needed to determine whether these genes have distinct or redundant functions in dorsoventral patterning and to provide critical tests of the proposed regulatory interactions among vox, vent and other genes that act to establish the dorsoventral axis. We show that vox and vent are redundant repressors of dorsal fates in zebrafish. Mutants that lack vox function have little or no dorsoventral patterning defect, and inactivation of either vox or vent by injection of antisense morpholino oligonucleotides has little or no effect on the embryo. In contrast, embryos that lack both vox and vent function have a dorsalized phenotype. Expression of dorsal mesodermal genes, including chordin, goosecoid and bozozok, is strongly expanded in embryos that lack vox and vent function, indicating that the redundant action of vox and vent is required to restrict dorsal genes to their appropriate territories. Our genetic analysis indicates that the dorsalizing transcription factor Bozozok promotes dorsal fates indirectly, by antagonizing the expression of vox and vent. In turn, vox and vent repress chordin expression, restricting its function as an antagonist of ventral fates to the dorsal side of the embryo. Our results support a model in which BMP signaling induces the expression of ventral genes, while vox and vent act redundantly to prevent the expression of chordin, goosecoid and other dorsal genes in the lateral and ventral mesendoderm.

Fast1 is required for the development of dorsal axial structures in zebrafish

Nodal-related signals comprise a subclass of the transforming growth factor-beta (TGF-beta) superfamily and regulate key events in vertebrate embryogenesis, including mesoderm formation, establishment of left-right asymmetry and neural patterning [1-8]. Nodal ligands are thought to act with EGF-CFC protein co-factors to activate activin type I and II or related receptors, which phosphorylate Smad2 and trigger nuclear translocation of a Smad2/4 complex [8-12]. The winged-helix transcription factor forkhead activin signal transducer-1 (Fast-1) acts as a co-factor for Smad2 [12-20]. Xenopus Fast-1 is thought to function as a transcriptional effector of Nodal signals during mesoderm formation [17], but no mutations in the Fast-1 gene have been identified. We report the identification of the zebrafish fast1 gene and show that it is disrupted in schmalspur (sur) mutants, which have defects in the development of dorsal midline cell types and establishment of left-right asymmetry [21-25]. We find that prechordal plate and notochord are strongly reduced in maternal-zygotic sur mutants, whereas other mesendodermal structures are present - a less severe phenotype than that caused by complete loss of Nodal signaling. These results show that fast1 is required for development of dorsal axial structures and left-right asymmetry, and suggest that Nodal signals act through Fast1-dependent and independent pathways.

Neocortical neurons lacking the protein-tyrosine kinase B receptor display abnormal differentiation and process elongation in vitro and in vivo

The spatial and temporal expression of the protein-tyrosine kinase B (TrkB) receptor and its ligands has been correlated with the development of the neocortex. Activation of the receptor has been associated with neocortical neuronal survival, differentiation, connectivity and neurotransmitter release. Although such findings suggest an important role for TrkB signaling in corticogenesis, conclusive evidence from targeted gene deletion ("knockout"; TrkB -/-) mice has been limited, due in part to the neonatal lethality of most of these mutant mice and the confounding variables associated with the poor health of those few surviving slightly longer postnatally. In the present study, the effects of TrkB signaling on the survival, differentiation and integration of neocortical neurons was directly investigated in vitro and in vivo. First, we conducted a neuron-specific immunocytochemical analysis of TrkB -/- mice to determine whether early cortical structure and patterns of histogenesis were normal or perturbed. We then employed in vitro and in vivo approaches to extend the life of TrkB -/- neocortical neurons beyond the period possible in TrkB -/- mutant mice themselves: (i) dissociated cell culture to directly compare the developmental potential of TrkB -/-, +/- and +/+ neurons; and (ii) neural transplantation into homochronic wild-type recipients to investigate the cell-autonomous effects of the receptor knockout on the differentiation, growth and integration of neocortical neurons. These latter experiments allowed, for the first time, study of the survival and differentiation potential of TrkB -/- neocortical neurons beyond the initial stages of corticogenesis. Direct comparison of brains of TrkB -/-, +/- and +/+ littermates immunocytochemically labeled with antibodies to microtubule-associated protein-2, neurofilament and beta-tubulin III revealed subtle anatomical anomalies in the mutant mice. These anomalies include abnormally diffuse microtubule-associated protein-2 positive neurons just dorsal to the corpus callosum, and heterotopic aggregations of postmitotic neurons in the subventricular zones of the ganglionic eminences, both suggesting delayed neuronal migration and differentiation. Cell culture experiments revealed substantially reduced survival by TrkB -/- neocortical neurons, and a significant reduction in neurite outgrowth by surviving TrkB -/- neurons. In experiments where prelabeled embryonic or neonatal TrkB -/- neocortical neurons were transplanted into the cerebral cortices of neonatal wild-type recipients, a similar quantitatively significant defect in the formation of dendrites, as well as reduced integration of TrkB -/- neocortical neurons, was also evident. These findings demonstrate cell-autonomous abnormalities in the development of neocortical neurons from TrkB -/- mice, and the subtle, but potentially critical, role of protein-tyrosine kinase B signaling in neocortical neuronal survival, differentiation and connectivity.

Long-term, EGF-stimulated cultures of attached GFAP-positive cells derived from the embryonic mouse lateral ganglionic eminence: in vitro and transplantation studies

Long-term attached cultures, prepared from mouse embryonic days 15-17 lateral ganglionic eminence, were grown in a medium including epidermal growth factor and serum, and the survival, differentiation, and migration of cells from either early or late passages were analyzed following transplantation. The cultured cells had the morphology of type I astroglial cells, with the vast majority of the cells immunoreactive for glial fibrillary acidic protein (around 90%), the intermediate filament marker nestin, and also the mouse-specific neural markers M2 and M6. The cultures were kept over 25 passages (7 months). During the first 8 passages, the growth rate gradually declined, but it increased again after passage 9 and thereafter stabilized at values similar to those observed during the initial culture period. After passages 4-6 and 18, cell suspensions were implanted cross-species into the intact or lesioned striatum of adult (passages 4-5 only) or intact striatum of neonatal rats (passages 4-6 or 18). Both early and late passage cells formed M2 (and M6)-positive transplants. In the neonatal recipients, widespread migration was seen from the needle tract throughout most of the striatum, along the internal capsule, and into the globus pallidus. In the adult striatum, the cells remained mostly around the injection tract, or within 0.4-0.6 mm from the graft core. These long-term attached cultures are interesting to compare to nonattached neurosphere cultures, and might also offer a means of propagating relatively pure populations of astroglia-like cells for basic transplantation studies or for use in experimental trials with ex vivo gene transfer.

A radiation hybrid map of the zebrafish genome

Recent large-scale mutagenesis screens have made the zebrafish the first vertebrate organism to allow a forward genetic approach to the discovery of developmental control genes. Mutations can be cloned positionally, or placed on a simple sequence length polymorphism (SSLP) map to match them with mapped candidate genes and expressed sequence tags (ESTs). To facilitate the mapping of candidate genes and to increase the density of markers available for positional cloning, we have created a radiation hybrid (RH) map of the zebrafish genome. This technique is based on somatic cell hybrid lines produced by fusion of lethally irradiated cells of the species of interest with a rodent cell line. Random fragments of the donor chromosomes are integrated into recipient chromosomes or retained as separate minichromosomes. The radiation-induced breakpoints can be used for mapping in a manner analogous to genetic mapping, but at higher resolution and without a need for polymorphism. Genome-wide maps exist for the human, based on three RH panels of different resolutions, as well as for the dog, rat and mouse. For our map of the zebrafish genome, we used an existing RH panel and 1,451 sequence tagged site (STS) markers, including SSLPs, cloned candidate genes and ESTs. Of these, 1,275 (87.9%) have significant linkage to at least one other marker. The fraction of ESTs with significant linkage, which can be used as an estimate of map coverage, is 81.9%. We found the average marker retention frequency to be 18.4%. One cR3000 is equivalent to 61 kb, resulting in a potential resolution of approximately 350 kb.

Site-specific migration and neuronal differentiation of human neural progenitor cells after transplantation in the adult rat brain

Neural progenitor cells obtained from the embryonic human forebrain were expanded up to 10(7)-fold in culture in the presence of epidermal growth factor, basic fibroblast growth factor, and leukemia inhibitory growth factor. When transplanted into neurogenic regions in the adult rat brain, the subventricular zone, and hippocampus, the in vitro propagated cells migrated specifically along the routes normally taken by the endogenous neuronal precursors: along the rostral migratory stream to the olfactory bulb and within the subgranular zone in the dentate gyrus, and exhibited site-specific neuronal differentiation in the granular and periglomerular layers of the bulb and in the dentate granular cell layer. The cells exhibited substantial migration also within the non-neurogenic region, the striatum, in a seemingly nondirected manner up to approximately 1-1.5 mm from the graft core, and showed differentiation into both neuronal and glial phenotypes. Only cells with glial-like features migrated over longer distances within the mature striatum, whereas the cells expressing neuronal phenotypes remained close to the implantation site. The ability of the human neural progenitors to respond in vivo to guidance cues and signals that can direct their differentiation along multiple phenotypic pathways suggests that they can provide a powerful and virtually unlimited source of cells for experimental and clinical transplantation.

Serial MR imaging of experimental autoimmune encephalomyelitis induced by human white matter or by chimeric myelin-basic and proteolipid protein in the common marmoset

BACKGROUND AND PURPOSE

Experimental autoimmune encephalomyelitis (EAE) in the marmoset was monitored by serial MR imaging to determine correlates to the natural-history MR studies in multiple sclerosis (MS). The relationships of MR-revealed lesions to clinical status and histopathologic findings were also explored.

METHODS

We induced EAE by subcutaneous inoculation in two marmosets by human white matter (HWM) and in seven marmosets by MP4 (a chimeric recombinant fusion protein of myelin-basic and proteolipid protein) in adjuvant along with intravenous inactivated pertussis vaccine to facilitate the disease process. The HWM-inoculated animals were induced with Freund's adjuvant as the established model of marmoset EAE. The MP4-inoculated animals were induced with either Freund's incomplete adjuvant or TiterMax as part of a preclinical treatment trial. MR imaging was performed at 1.5 T at baseline, and repeated at 1- to 2-week intervals for a period of up to 16 weeks in six EAE-induced marmosets, and intermittently for up to 70 weeks in three EAE-induced and two control marmosets. Proton density- (PD-) and T2-weighted, pre- and postgadopentetate dimeglumine enhancement, T1-weighted, and magnetization transfer (MT) images were obtained. The brains were prepared for histologic evaluation of lesion distribution and counts, characterization of lesions as demyelinating or inflammatory, and histopathologic scoring. The clinical, MR, and pathologic scoring were done on grading systems, and correlated for evaluation.

RESULTS

White matter (WM) changes after EAE induction were observed first at 9 days in the HWM-induced animals and at 2.5 weeks in the MP4-induced animals, with subsequent week-to-week fluctuations on PD- and T2-weighted images. Contrast-enhancing lesions were not observed in all animals. MR-revealed WM lesions correlated to histopathologic analysis of EAE lesions, measuring from 0.5 mm to 1.5 mm. The lesion count and extent of demyelination was greater in the HWM-induced animals than in the MP4-induced animals. Some MR-revealed lesions correlated directly to clinical symptoms, but the majority of lesions were clinically silent.

CONCLUSION

On MR images, lesions in the EAE marmoset model were confined to the WM, and their development, resolution, distribution, and enhancing characteristics fluctuated over the duration of the study. The dynamic presentation of MR-revealed lesions confirms the parallels between EAE in the marmoset and relapsing-remitting MS. Clinical symptoms alone were not representative of ongoing pathologic brain lesions. Therefore, serial MR imaging serves as a very important adjunct to clinical and histologic surveillance of the development of new and the persistence of existing brain lesions in this animal model of MS.

A genetic linkage map for zebrafish: comparative analysis and localization of genes and expressed sequences

Genetic screens in zebrafish (Danio rerio) have isolated mutations in hundreds of genes with essential functions. To facilitate the identification of candidate genes for these mutations, we have genetically mapped 104 genes and expressed sequence tags by scoring single-strand conformational polymorphisms in a panel of haploid siblings. To integrate this map with existing genetic maps, we also scored 275 previously mapped genes, microsatellites, and sequence-tagged sites in the same haploid panel. Systematic phylogenetic analysis defined likely mammalian orthologs of mapped zebrafish genes, and comparison of map positions in zebrafish and mammals identified significant conservation of synteny. This comparative analysis also identified pairs of zebrafish genes that appear to be orthologous to single mammalian genes, suggesting that these genes arose in a genome duplication that occurred in the teleost lineage after the divergence of fish and mammal ancestors. This comparative map analysis will be useful in predicting the locations of zebrafish genes from mammalian gene maps and in understanding the evolution of the vertebrate genome.