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Biomedical subjects

A Correa-Villaseñor

Publications and source records attributed to A Correa-Villaseñor.

17 recordsLinked to original sources
PubMed2001

Folic acid supplementation and risk for imperforate anus in China.

Maternal consumption of folic acid before pregnancy and during early pregnancy is associated with a reduced risk for some birth defects. Whether folic acid can reduce the risk for imperforate anus is unknown. As part of a public health campaign conducted in China from 1993 through 1995, the outcomes of pregnancies of > or =20 weeks' gestation were evaluated among women using folic acid supplements. The women were asked to take one pill containing 400 microg of folic acid (without other vitamins) every day from the time of their premarital examination until the end of their first trimester of pregnancy. Rates of imperforate anus and risk ratios for imperforate anus among the offspring of these women were calculated according to folic acid use. Among the offspring of women who took folic acid and women who did not take folic acid, 20 and 30 infants with imperforate anus were identified, respectively. The rate of imperforate anus was 3.1 per 10,000 among the offspring of women who did not take folic acid and 1.6 per 10,000 among the offspring of women who took folic acid; adjusted for maternal age, the risk ratio was 0.59 (95% confidence interval: 0.33, 1.07). Daily maternal consumption of 400 microg of folic acid before and during early pregnancy may reduce the risk for imperforate anus.

Adult↗
PubMed1998

Attributable fraction for cardiac malformations.

To the authors' knowledge, attributable fractions for cardiac malformations have not been reported before. The Baltimore-Washington Infant Study published factors associated with several major cardiac malformations in Maryland, the District of Columbia, and adjacent counties of northern Virginia in 1981-1989. For eight of these malformations, the authors provide attributable fractions of those factors that are potentially causal. Summary attributable fractions range from 13.6% (four factors) for hypoplastic left heart to 30.2% (seven factors) for transposition of great arteries with intact ventricular septum. Extra attributable fraction for factor x, defined as summary attributable fraction for all factors minus that for all but x, is largest for: 1) paternal marijuana use in transposition of great arteries with intact ventricular septum, 7.8%; 2) paternal anesthesia in tetralogy of Fallot, 3.6%; 3) painting in atrioventricular septal defect with Down syndrome, 5.1 %; 4) solvent/degreasing agent exposure in hypoplastic left heart, 4.6%; 5) sympathomimetics in coarctation of aorta, 5.8%; 6) pesticide exposure in isolated membranous ventricular septal defect, 5.5%; 7) hair dye in multiple/multiplex membranous ventricular septal defect, 3.3%; and 8) urinary tract infection in atrial septal defect, 6.4%. Percent-of-cases-exposed dominates relative risk in attributable fraction. If these factors are causal, the larger extra attributable fractions suggest the potential for prevention by specific interventions before/during pregnancy.

Case-Control Studies↗
PubMed1998

Preconceptional folate intake and malformations of the cardiac outflow tract. Baltimore-Washington Infant Study Group.

We compared cases with outflow tract defects (N = 126) with controls representative of the same birth cohort (N = 679). Infants with clinically recognized syndromes were excluded. Daily total maternal folate intake of > or =245 microg was inversely related to risk of cardiac outflow tract defects among those with transposition (odds ratio estimates: 0.65, 0.78, and 0.76 with increasing quartile of daily folate intake), but positively related among those with normally related vessels (corresponding odds ratio estimates: 1.18, 1.59, and 1.68). This difference disappeared when maternal intake of supplemental folic acid of > or =400 microg compared with <400 microg was considered, excluding dietary intake [odds ratio (OR) = 1.04; 95% confidence interval (CI) = 0.5-2.2 for infants with transposition, and OR = 0.91; 95% CI = 0.5-1.8 for those without transposition of the great arteries].

Dietary Supplements↗
PubMed1996

Drinking water nitrate and the risk of non-Hodgkin's lymphoma.

The increasing incidence of non-Hodgkin's lymphoma (NHL) in the United States is only partially explained by known risk factors. Nitrate is a contaminant of drinking water in many rural areas. We evaluated its association with NHL after accounting for dietary nitrate intake. For 156 cases and 527 controls who used Nebraska community supplies, average nitrate exposure was estimated from 1947 through 1979. Longterm consumption of community water with average nitrate levels in the highest quartile (> or = 4 mg per liter nitrate-nitrogen) was positively associated with risk [odds ratio (OR) = 2.0; 95% confidence interval (CI) = 1.1-3.6]. Dietary nitrate, which came mainly from vegetables, was not associated with NHL risk, after adjusting for vitamin C and carotene intakes. Persons with a lower intake of vitamin C were at slightly higher risk of developing NHL than persons whose daily intake was > or = 130 mg, for all levels of intake of drinking water nitrate; our findings were similar for the combined effect of water nitrate and carotene intake. Nitrate levels in private wells were measured at the time of the interview for 51 cases and 150 controls but were not associated with the risk of NHL after adjusting for pesticide use on the farm. These findings indicate that longterm exposure to elevated nitrate levels in drinking water may contribute to the risk of NHL.

Adult↗
PubMed1996

Parental occupational lead exposure and low birth weight.

This study suggests that paternal occupational lead exposure may be associated with low birth weight in the offspring. The odds of low birth weight rose fivefold among infants of fathers who were potentially exposed to high levels of lead during the period 6 months before pregnancy to the end of pregnancy (adjusted odds ratio (aOR) = 4.7, 95% confidence interval (CI) = 1.1-20). This effect was most prominent for low-birth-weight infants who were both preterm and small for gestational age. There was a suggestion of a gradual increase of the odds of low birth weight at medium levels of exposure, but this increase was not statistically significant. No increased odds was observed at low levels of exposure. Low birth weight was not associated with paternal ever versus never exposure, indirect exposure, or exposure frequency. An independent effect of exposure duration could not be evaluated as it was highly correlated with exposure level.

Analysis of Variance↗
PubMed1995

Bias from nondifferential misclassification in case-control studies with three exposure levels.

In case-control studies with three exposure levels where disease risk is associated with exposure, the direction of bias in the odds ratios (ORs) from nondifferential misclassification depends on the risk level, misclassification rates, and exposure distributions. To extend these generalizations, we present a graphical analysis of bias from nondifferential misclassification assuming linear and nonlinear monotonic increasing exposure-risk patterns. In both middle and upper exposure levels, bias is usually toward the null, increasing in magnitude as the misclassification rates increase and as the skewness of the exposure distribution increases. In the middle exposure level, bias away from the null may occur when the misclassification rate is low in the reference level and moderate to high in the upper exposure level, and risk increases with exposure. Bias away from the null does not occur in the upper exposure level. In both excess risk levels, crossover bias (that is, a reversal of the OR) may occur when exposure classification is worse than chance. The magnitude of bias away from the null is constrained by the unbiased OR of the upper exposure level, whereas that of crossover bias is constrained by the inverse of the unbiased OR of the upper exposure level.

Bias↗
PubMed1994

Ebstein's malformation of the tricuspid valve: genetic and environmental factors. The Baltimore-Washington Infant Study Group.

Ebstein's anomaly is a specific structural deformity of the tricuspid valve, and its rarity has hampered etiologic evaluation. Cases of Ebstein's anomaly registered in the Baltimore Washington Infant Study (BWIS), a regional case-control study of cardiovascular malformations (CVM) in infancy, are reviewed. Between 1981 and 1989 a total of 4,390 CVM cases, including 47 Ebstein cases, and 3,572 controls were registered. The prevalence of Ebstein's anomaly was 5.2 per 100,000 livebirths. Additional cardiac anomalies were present in 38.3% of Ebstein cases. Non-cardiac malformations were present in 19.1% of Ebstein cases vs. 25.5% of other CVM, and 1.7% of controls. Case-fatality by 1 year of age was 23.4% in Ebstein vs. 18.1% in other CVM. Interviews of parents of Ebstein cases, other CVM, and controls (n = 44, 3,335, and 3,572, respectively) elicited information on family history of malformations, maternal illnesses, reproductive history, therapeutic drugs, parental lifestyle, and environmental exposures during the periconceptional period. Case-control analyses suggest genetic, reproductive, and environmental risk factors: twins [odds ratio (OR) 8.2, 95% confidence interval (CI) 2.6-25.3]; family history of CVM (OR 6.4, 95% CI 1.8-22.2); white race (OR 2.9 with non-whites as reference, 95% CI 1.2-7.0); previous miscarriages (OR 2.0, 95% CI 1.2-3.3); maternal exposure to benzodiazepines (OR 5.4, 95% CI 1.5-19.1); and varnishing (OR 3.4, 95% CI 1.3-9.1). Additional multicenter investigations are warranted to elucidate the role of genetic, reproductive, and environmental factors in the etiology of this anomaly.

Adult↗
PubMed1993

Cancer epidemiology among styrene-butadiene rubber workers.

The standardized mortality ratios for some cancers of the lymphohaematopoietic system were high in an early cohort analysis. Since the presence of large numbers of unexposed workers could conceal risks within a cohort, a case-control study was designed to examine the relationship between estimated exposures and the occurrence of these cancers. The results suggested that the risk for leukaemia was associated with exposure to butadiene and with work in specific areas. Modelling, using rank scores, indicated an increase in the risk for leukaemia with increasing exposure score. Use of cases validated by review of hospital records and selection of a new set of controls did not change the findings. The data indicated that comparison of scores within the same time frame improved the model and increased the estimated odds ratio, suggesting that exposure time or dose rate may prove to be the important variable for risk. Exact measurements from the companies involved showed significant correlations between assigned ranks and level of exposure derived from personal monitoring for butadiene but not for styrene. Thus, use of the measured values might be expected to show an association between leukaemia and exposure to butadiene. The standardized mortality ratio for leukaemia among long-term workers hired before 1960 who had worked in the three plants where the geometric mean butadiene level was three to five times higher than those in the other plants is 1.8 times higher than that of the US population. An appropriate algorithm for comparing cases and controls on the bases of the measured samples is being developed.

Butadienes↗
PubMed1993

Temporal trends in prevalence of cardiovascular malformations in Maryland and the District of Columbia, 1981-1988. The Baltimore-Washington Infant Study Group.

We studied the yearly occurrence of isolated cardiovascular malformations in liveborns for the period 1981-1988 in Maryland and the District of Columbia. We used Poisson regression to fit yearly prevalence at birth as a function of time for all cardiovascular malformation case types combined and for three diagnostic subgroups. We give results separately by diagnostic method and race (white/nonwhite), with categories combined when appropriate. Time trends were similar for both races except in pulmonic stenosis diagnosed by echocardiography. The yearly prevalence for all case types, all races, and all diagnostic methods combined increased from 28 to 43 per 10,000 livebirths over the 8 years, due to an increase in the rate among infants diagnosed by echocardiography. For every diagnostic-type-by-race group studied, there were increases in the prevalence for those diagnosed by echocardiography and decreases (or no change in one group) for those diagnosed by cardiac catheterization and/or surgery. Although there may have been an increase in actual occurrence of cardiovascular malformation over our study period, it is also possible that wider use of a new echocardiography technology resulted in increased detection.

Black People↗
PubMed1993

Paternal exposures and cardiovascular malformations. The Baltimore-Washington Infant Study Group.

Possible associations between paternal exposures and cardiovascular malformations were evaluated in the Baltimore-Washington Infant Study, a population based case-control investigation of congenital heart disease and environmental factors. Home interviews of case and control parents elicited information on parental home and occupational exposures. Analysis focused on twelve cardiac diagnostic groups and paternal exposures incurred during the six months preceding the pregnancy. Associations were identified between jewelry making and atrial septal defect (Odds ratio: 12.6; 95% confidence interval: 2.3-68.6) and membranous ventricular septal defect (8.1; 2.0-33.3), welding and endocardial cushion defect with Down syndrome (1.8; 1.1-3.0), lead soldering and pulmonary atresia (2.3; 1.1-4.9) and ionizing radiation and endocardial cushion defect without Down syndrome (4.7; 1.7-12.6). Ionizing radiation was found to be associated with endocardial cushion defect with Down syndrome only when father was present at interview (5.6; 1.7-17.9); a similar effect of father at interview was noted for paint stripping in relation to coarctation of the aorta (3.5; 1.5-8.0) and muscular ventricular septal defect (3.5; 1.5-8.5). Also, paint stripping was associated with hypoplastic left heart only in the presence of family history of cardiac defects (11.9; 2.4-60.0). This large study on cardiac diagnostic groups and specific preconceptional exposures provides new leads for further assessment of the role of paternal exposures on adverse pregnancy outcome.

Adult↗
PubMed1991

White-black differences in cardiovascular malformations in infancy and socioeconomic factors. The Baltimore-Washington Infant Study Group.

Cardiovascular malformations were examined for white/black variation in the Baltimore-Washington Infant Study. In this population-based case-control study, cases (n = 2,087) were live births with cardiovascular malformations ascertained through pediatric cardiology centers and 53 hospitals in Maryland, the District of Columbia, and northern Virginia between 1981 and 1987. Controls (n = 2,721) were a random sample of infants from the live-birth cohort that gave rise to the cases. The proportion of infants that were white was similar for all cases as a group and controls (0.68 and 0.67, respectively). Subgroup analysis, however, revealed an excess of white infants among cases with Ebstein's anomaly (odds ratio (OR) = 3.7, 95% confidence interval (Cl) 1.1-12.5), aortic stenosis (OR = 3.6, 95% Cl 1.7-7.6), pulmonary atresia (OR = 2.5, 95% Cl 1.0-6.1), coarctation of the aorta (OR = 2.2, 95% Cl 1.4-3.5), and D-transposition of the great arteries (OR = 1.6, 95% Cl 1.1-2.5), and a deficit of white infants among cases with pulmonary stenosis (OR = 0.6, 95% Cl 0.4-0.8) and heterotaxia (OR = 0.4, 95% Cl 0.3-0.8). These associations remained when cases were stratified by infant's age or by method of diagnosis. Controlling for socioeconomic factors attenuated the white excess for Ebstein's anomaly (OR = 3.0, 95% Cl 0.9-10.5), disclosed a white excess among cases of L-transposition of the great arteries (OR = 2.8, 95% Cl 1.0-8.0), and revealed that the white excess for aortic stenosis was limited to low and middle socioeconomic strata. These results highlight racial variations in cardiovascular malformations, suggest that socioeconomic factors account for some of this variation, and identify malformation subgroups for which further evaluation of sociocultural, environmental, and familial factors is needed.

Black or African American↗
PubMed1991

Total anomalous pulmonary venous return: familial and environmental factors. The Baltimore-Washington Infant Study Group.

In total anomalous pulmonary venous return (TAPVR), the intrapulmonary venous plexus has failed to connect to the left atrium, so that the pulmonary veins drain into right atrial tributaries, frequently resulting in early postnatal circulatory distress. The Baltimore-Washington Infant Study (BWIS), a population-based exploratory case-control study of cardiovascular malformations (CVM), identified 41 cases of TAPVR during 1981-1987: 1.5% of all CVM (N = 2659), a regional prevalence of 6.8/100,000 live births. Of the TAPVR infants, 68% were diagnosed as neonates, 88% had surgery, and 51.2% were alive at 1 year of age. Noncardiac malformations were present in nine cases (22%); the male-female ratio was 0.78 (18.23). Compared with a control group representative of the birth cohort (N = 2,801), more TAPVR patients had low birthweight (less than 2,500 g: 16.2% vs. 6.9%, short gestational age (less than 38 weeks: 18.9% vs. 9.3%), and intrauterine growth retardation (IUGR) (26.8% vs. 5.8%). Sociodemographic findings were similar to those of controls, except that fewer TAPVR mothers received private pregnancy care (59.5% vs. 71.4%). Family history revealed no other TAPVR-affected members, but a significant linear trend of increased risk was found over the ordered malformation categories (familial noncardiac, cardiac, both). Bivariate analysis of TAPVR and exposure in life-style, hobbies, and work showed possible associations for exposure to lead (OR 2.9; 99% confidence interval [CI]: 1.2, 7.2), painting/paint stripping (OR 3.3; 99% CI: 1.3, 8.4), lead soldering (OR 13.3; 99% CI: 1.8, 99.2), and pesticides (OR 2.7; 99% CI: 1.2, 6.4). Multivariate analysis suggested an interaction between pesticide exposure and family history and, thus, a possible familial susceptibility to environmental teratogens. Although the number of TAPVR cases is small, this epidemiologic study identifies hypotheses that may be further explored in morphogenetic and epidemiology studies. Total anomalous pulmonary venous return (TAPVR) constitutes a well-defined clinical entity in which the pulmonary veins fail to enter the left atrium and instead drain into the right atrium or its systemic venous tributaries (Neill, '56; Rowe et al., '81). During intrauterine life, the malformation does not compromise the fetal circulation, since the pulmonary arterial resistance is high and the patent foramen ovale provides easy access of right atrial blood to the left side of the heart. At birth, however, the pulmonary vascular resistance begins to fall, and the presence of a severe hemodynamic disturbance becomes increasingly evident (Ferencz et al., '71).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1984

Campylobacter enteritis on Hopi and Navajo Indian reservations. Clinical and epidemiologic features.

From June 22 through September 30, 1981, stool specimens from 522 Hopi and Navajo outpatients were cultured because of diarrheal illnesses at the Keams Canyon Indian Health Service Hospital, Arizona. Campylobacter jejuni was isolated from the specimens of 26 (5%) of the patients. This pathogen was found as frequently as Shigella in patients younger than 2 years or older than 20 years, but was significantly less common in the 2 to 20-year age group (P<.000001). Campylobacter enteritis was indistinguishable clinically from shigellosis in adult patients, but in children younger than 5 years, a rectal temperature higher than 38 degrees C (100.5 degrees F) was significantly more common with Shigella than with Campylobacter infection (P=.003). In a field study of 20 families, we found that households with a case of Campylobacter enteritis were more likely than age- and community-matched controls to own farm animals (P=.05), but were not more likely to own household pets. C jejuni is less common than Shigella as a cause of summer seasonal diarrhea and dysentery among the Hopi and Navajos; the striking differences in the age-specific rates of these two infections suggest different routes of transmission.

Adolescent↗
PubMed1982

Reye's syndrome and medication use.

Ninety-seven Reye's syndrome (RS) cases in Ohio children with onsets from December 1978 through March 1980 were studied for medication use during their pre-RS illness. They were matched with 156 control subjects for age, race, sex, geographic location, time, and type of illness. Only the use of aspirin was reported by significantly more cases (97%, 94/97) than controls (71%, 110/156) during the pre-RS matched illness. Using a multiple logistic model to control for the presence of fever, headache, and sore throat statistically, the difference in aspirin use remained significant. Conversely, fewer cases (16%) took medications containing acetaminophen than controls (33%). In 87% of the cases receiving aspirin, their maximum daily dosage did not exceed recommended levels, but their doses were higher than those of controls receiving aspirin. No relationship was found between dosage and stage of RS encephalopathy.

Acetaminophen↗
PubMedDate not supplied

Contribution of occupation and diet to white blood cell polycyclic aromatic hydrocarbon-DNA adducts in wildland firefighters.

Wildland (forest) firefighters are exposed to a wide range of carcinogenic polycyclic aromatic hydrocarbons (PAH) in forest fire smoke. PAH undergo metabolic activation and can subsequently bind to DNA. In this study, we investigated the association between occupational and dietary PAH exposures and the formation of WBC PAH-DNA adducts in a population of wildland firefighters. An enzyme-linked immunosorbent assay using an antiserum elicited against benzo(a)pyrene-modified DNA was used to measure PAH-DNA adducts in WBC obtained from 47 California firefighters at two time points, early and late in the 1988 forest fire season. PAH-DNA adduct levels were not associated with cumulative hours of recent firefighting activity. However, firefighters who consumed charbroiled food within the previous week had elevated PAH-DNA adduct levels, which were related to frequency of charbroiled food intake. These findings suggest that dietary sources of PAH contribute to PAH-DNA adduct levels in peripheral WBC and should be evaluated when using this assay to assess occupational and environmental PAH exposure.

Adolescent↗