Biomedical subjects

C D O'Malley

Publications and source records attributed to C D O'Malley.

At least 19 recordsLinked to original sources

PubMed2001

Factors associated with missing birthplace information in a population-based cancer registry.

Differences in cancer occurrence within a racial/ethnic group may be influenced by migrant status or level of acculturation, which can indicate variations in environmental exposures. When immigration and acculturation data on individual patients are not available, birthplace may serve as a proxy. As part of a larger study intended to assess the utility of the birthplace variable in the Greater Bay Area Cancer Registry (GBACR), part of the Surveillance, Epidemiology, and End Results (SEER) program, we measured its completeness, and determined whether missing birthplace is associated with patient and hospital reporting source characteristics. Subjects were persons diagnosed with cancer within the GBACR surveillance area during the period 1988-1996. Of the 204,553 subjects, 67% had birthplace recorded in the registry. Deceased persons were 10 times more likely than living persons to have data on birthplace. Racial/ethnic groups which included more foreign-born persons, such as Southeast Asians, tended to have more complete birthplace information than did groups with fewer foreign-born, such as Japanese and Hispanics. The effects of patient and reporting source characteristics on birthplace completeness differed across racial/ethnic groups. These data indicate that completeness of the birthplace variable in the GBACR is biased, and that investigators considering birthplace in analyses of SEER data should consider these biases. For birthplace data to be useful, completeness needs to be improved at the level of the diagnosing facility.

Adolescent↗

PubMed1999

Maternal pesticide exposure from multiple sources and selected congenital anomalies.

We explored the relation between various potential sources of maternal periconceptional pregnancy exposures to pesticides and congenital anomalies in offspring. Data were derived from a case-control study of fetuses and liveborn infants with orofacial clefts, neural tube defects, conotruncal defects, or limb anomalies, among 1987-1989 California births and fetal deaths. We conducted telephone interviews with mothers of 662 (85% of eligible) orofacial cleft cases, 265 (84%) neural tube defect cases, 207 (87%) conotruncal defect cases, 165 (84%) limb cases, and 734 (78%) nonmalformed controls. The odds ratio (OR) estimates did not indicate increased risk for any of the studied anomaly groups among women whose self-reported occupational tasks were considered by an industrial hygienist likely to involve pesticide exposures. Paternal occupational exposure to pesticides, as reported by the mother, revealed elevated ORs for only two of the cleft phenotypes [OR = 1.7 [95% confidence interval (CI) = 0.9-3.4] for multiple cleft lip with/without cleft palate and OR = 1.6 [95% CI = 0.7-3.4] for multiple cleft palate]. Use of pesticide products for household gardening, by mothers or by professional applicators, was associated with ORs > or =1.5 for most of the studied anomalies. Use of pesticide products for the control of pests in or around homes was not associated with elevated risks for most of the studied anomalies, although women who reported that a professional applied pesticides to their homes had increased risks for neural tube defect-affected pregnancies [OR = 1.6 (95% CI = 1.1-2.5)] and limb anomalies [OR = 1.6 (95% CI = 1.0-2.7)]. Having a pet cat or dog and treating its fleas was not associated with increased anomaly risk. Women who reported living within 0.25 miles of an agricultural crop revealed increased risks for offspring with neural tube defects [OR = 1.5 (95%CI = 1.1-2.1)]. For many of the comparisons, data were sparse, resulting in imprecise effect estimation. Despite our investigating multiple sources of potential pesticide exposures, without more specific information on chemical and level of exposure, we could not adequately discriminate whether the observed effects are valid, whether biased exposure reporting contributed to the observed elevated risks, or whether nonspecific measurement of exposure was responsible for many of the observed estimated risks not being elevated.

Adult↗

PubMed1998

Tetanus associated with body piercing.

Explore the source record for details and available documents.

Adult↗

PubMed1996

Parental cigarette smoking and risk for congenital anomalies of the heart, neural tube, or limb.

Risks for selected congenital anomalies from parental smoking were investigated in a case-control study in California. Mothers of 207 infants with conotruncal heart defects, 264 infants with neural tube defects, 178 infants with limb deficiencies, and 481 live born control infants delivered in 1987-1988 were interviewed by telephone. Modestly elevated risks were observed for conotruncal heart defects and limb deficiencies, associated primarily with both parents smoking. An odds ratio of 1.9 (95 percent confidence interval 1.2-3.1) was observed for conotruncal heart defects and an odds ratio of 1.7 (95% confidence interval 0.96-2.9) for limb deficiencies when both parents smoked compared to neither parent smoking. We did not observe increased risks associated with maternal smoking in the absence of paternal smoking, although an increased risk associated with paternal smoking in the absence of maternal smoking was observed for limb deficiencies in offspring. For conotruncal defects, the risks associated with parental smoking differed among race/ethnic groups. Parental smoking was not associated with increased risks for neural tube defects. Observed risks did not change substantially when adjusted for maternal vitamin use, alcohol use, and gravidity. Some heterogeneity in risk was observed for phenotypic case subgroups, but data were too sparse to draw firm inferences.

Case-Control Studies↗

PubMed1996

Epidemiologic characteristics of conotruncal heart defects in California, 1987-1988.

In this population-based case-control study, we explored the association of selected parental and infant characteristics from the birth certificates of children with conotruncal heart defects. We compared 252 cases to a random sample of 5,000 nonmalformed infants from a cohort of 341,839 California live births for 1987-1988. The prevalence of conotruncal defects was 0.732 per 1,000 total births. A decreased risk (OR = 0.55, 95% CI0.33-0.89) for delivering infants with conotruncal defects was found among mothers born in Mexico compared to mothers born in California. An increased risk was observed for Native American mothers compared to non-Hispanic whites (OR = 2.6, 95% CI 1.1-6.0). We also compared risks associated with the individual diagnoses that comprise the group of conotruncal defects. Only minor differences in risk estimates between the anatomic diagnoses were observed, lending support to the methodologic approach of using conotruncal defects as a single category of heart defects in etiologic investigations.

California↗

PubMed1996

Orofacial clefts, parental cigarette smoking, and transforming growth factor-alpha gene variants.

Results of studies to determine whether women who smoke during early pregnancy are at increased risk of delivering infants with orofacial clefts have been mixed, and recently a gene-environment interaction between maternal smoking, transforming growth factor-alpha (TGFa), and clefting has been reported. Using a large population-based case-control study, we investigated whether parental periconceptional cigarette smoking was associated with an increased risk for having offspring with orofacial clefts. We also investigated the influence of genetic variation of the TGFa locus on the relation between smoking and clefting. Parental smoking information was obtained from telephone interviews with mothers of 731 (84.7% of eligible) orofacial cleft case infants and with mothers of 734 (78.2%) nonmalformed control infants. DNA was obtained from newborn screening blood spots and genotyped for the allelic variants of TGFa. We found that risks associated with maternal smoking were most elevated for isolated cleft lip with or without cleft palate, (odds ratio 2.1 [95% confidence interval 1.3-3.6]) and for isolated cleft palate (odds ratio 2.2 [1.1-4.5]) when mothers smoked > or =20 cigarettes/d. Analyses controlling for the potential influence of other variables did not reveal substantially different results. Clefting risks were even greater for infants with the TGFa allele previously associated with clefting whose mothers smoked > or =20 cigarettes/d. These risks for white infants ranged from 3-fold to 11-fold across phenotypic groups. Paternal smoking was not associated with clefting among the offspring of nonsmoking mothers, and passive smoke exposures were associated with at most slightly increased risks. This study offers evidence that the risk for orofacial clefting in infants may be influenced by maternal smoke exposures alone as well as in combination (gene-environment interaction) with the presence of the uncommon TGFa allele.

Adult↗

PubMed1995

Maternal periconceptional use of multivitamins and reduced risk for conotruncal heart defects and limb deficiencies among offspring.

We investigated whether a woman's periconceptional use of a multivitamin containing folic acid was associated with a reduced risk for delivering offspring with a conotruncal heart defect or a limb deficiency. Data were derived from a population-based case-control study of fetuses and liveborn infants with conotruncal or limb defects among a 1987-88 cohort of births in California. Telephone interviews were conducted with mothers of 207 (87.0% of eligible) conotruncal cases, 178 (82.0%) limb defect cases, and of 481 (76.2%) randomly selected liveborn nonmalformed control infants. Reduced risks were observed for maternal use of multivitamins containing folic acid from one month before until two months after conception. Odds ratios and 95% confidence intervals for any compared to no multivitamin use were 0.70 (0.46-1.1) for conotruncal defects and 0.64 (0.41-1.0) for limb defects. Controlling for maternal race/ethnicity, age, education, gravidity, alcohol use, and cigarette use resulted in a further reduction to the odds ratio for conotruncal defects, 0.53 (0.34-0.85), but not for limb defects. Among non-vitamin using women, consumption of cereal containing folic acid was also associated with reduced risk for both defects. Women who take multivitamins have 30-35% lower risk of delivering offspring with either conotruncal or limb defects. This association may not be attributable to folic acid specifically, but may be a consequence of other multivitamin components, or some unknown behaviors that highly correlate with regular use of a multivitamin. However, should the association prove causal, it offers an important opportunity for preventing thousands of serious birth defects.

Case-Control Studies↗

PubMed1995

Risks of orofacial clefts in children born to women using multivitamins containing folic acid periconceptionally.

Women are advised to take folic acid before they conceive as a precaution against neural-tube defects. However, the use of folic acid in preventing orofacial clefts is unknown. We investigated whether a woman's periconceptional use of multivitamins containing folic acid was associated with a reduced risk of orofacial clefts. We derived data from a population-based case-control study of fetuses and liveborn infants with orofacial anomalies among a 1987-89 cohort of births in California. We interviewed 731 (84.7%) of eligible mothers with orofacial cleft case infants and 734 (78.2%) mothers with non-malformed control infants. We found a reduced risk of orofacial clefts if the mother had used multivitamins containing folic acid during the period from one month before through two months after conception. The odds ratios ranged from 0.50-0.73 depending on cleft phenotype. Controlling for the potential influence of other variables did not substantially alter the results. Maternal daily consumption of cereal containing folic acid was also associated with a reduced risk of orofacial clefts. Women who used multivitamins containing folic acid periconceptionally had a 25-50% reduction in risk for offspring with orofacial clefts compared to women who did not use such vitamins. However, this association may not be attributable to folic acid specifically, but may be a consequence of other multivitamin supplement components, or behaviours, that are highly correlated with the use of multivitamins containing folic acid.

Adult↗

PubMed1975