Biomedical subjects

Lucina Suarez

Publications and source records attributed to Lucina Suarez.

26 records · Page 2Linked to original sources

PubMed2003

Homocysteine remethylation enzyme polymorphisms and increased risks for neural tube defects.

Folic acid supplementation can effectively reduce the risk of neural tube defects (NTDs); however, the mechanism underlying this beneficial effect remains unclear. Recent evidence suggests that certain folate pathway genes, as well as those related to homocysteine metabolism might be contributing to this effect. The purpose of this study is to investigate whether gene polymorphisms of methionine synthase (MTR) and methionine synthase reductase (MTRR) are involved in the risk for NTDs, specifically spina bifida. We detected MTR A2756G and MTRR A66G polymorphisms using PCR-RFLP analysis in a group of NTD infants, their mothers and normal controls. We found that infants with the MTRR mutant genotype had a 2.6-fold higher risk of NTDs when compared to the AA genotype (OR = 2.6, 95%CI = 1.3-5.3). Mothers with the MTRR mutant genotype also had a 1.9-fold higher risk of having an NTD baby compared to AA genotype (OR = 1.9, 95%CI = 1.1-3.1). Infants who carry mutant alleles for both MTRR and MTR had exceptionally elevated NTD risks, with odds ratios of 5.1 compared to infants with the wild type genotype at both loci (AA + AA) (OR = 5.1, 95%CI = 1.7-15.4). A comparable result was observed in the mothers of NTD cases (OR = 2.1, 95%CI = 1.0-4.7). Our results indicate that MTRR and MTR genes may interact to increase the infants' NTD risks. These results did not appear to be influenced by maternal periconceptional folic acid intake. However,the sample size of this study was limited, and a larger population study is needed to pursue these initial observations.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

PubMed2003

Maternal stress, social support, and risk of neural tube defects among Mexican Americans.

BACKGROUND: Studies suggest that maternal psychologic stress can increase the risk of congenital malformations, including neural tube defects (NTDs). We examined whether maternal stress and lack of social support contribute to NTD risk in a population living along the Texas-Mexico border. METHODS: Case mothers (N = 184) were Mexican-American women with NTD-affected pregnancies who delivered during 1995 to 2000 in one of the 14 Texas counties bordering on Mexico. Control mothers (N = 225) were randomly selected from Mexican-American women residing in the same area and delivering normal live births. We measured maternal stress by tallying the number of job changes, residential moves, and major injuries occurring during the year before conception. Social support was measured using social integration and perceived emotional support scales. RESULTS: Mothers who experienced one or more stressful life events during the year before conception had increased risks for NTDs (odds ratio [OR] = 2.9; 95% confidence interval [CI] = 1.8-4.7) compared with mothers experiencing no events. Mothers who scored low on emotional support had an elevated risk compared with those who scored high (OR = 4.6; CI = 2.2-9.7). Social support measures, such as network size and satisfaction, group interactions, and church attendance, were unrelated to NTD risk. The estimated effects were not modified or confounded by age, education, country of birth, income, obesity, vitamin supplements, dietary folate, cigarette smoking, or alcohol consumption. CONCLUSION: In this Mexican-American population, the occurrence of stressful life events was associated with NTD risk. These findings suggest that stress may exacerbate risk in populations with poor nutritional status and meager economic resources.

Adult↗

PubMed2003

Health risks of residential exposure to polycyclic aromatic hydrocarbons.

A disease prevalence study and follow-up health surveillance were conducted among residents of an African-American community situated at the site of a former creosote wood-treatment facility contaminated with polycyclic aromatic hydrocarbons. Household interviews were conducted among 214 residents living around the hazardous waste site (target population) and 212 comparison residents in a neighborhood 2.4 km away from the site. Target area residents reported a higher prevalence of skin rashes than comparison residents (relative risk [RR] = 5.7; 95% confidence interval [CI] = 3.0, 10.9). The prevalence of reported rashes increased with increasing levels of anthracene detected in yards (test for linear trend, p = 0.02). With adjustment for environmental worry, reports of chronic bronchitis and difficulties becoming pregnant did not differ significantly between target and comparison residents (p > 0.05).

Adolescent↗

PubMed2002

Predictors of digital rectal examination in U.S. Latinos.

BACKGROUND: Little is known about prostate and colorectal cancer knowledge, attitudes, and screening practices among U.S. Latino men. Even less is known about the population's subgroup variations. This study assessed predictors of having obtained digital rectal examinations (DREs) among four Latino subgroups. METHODS: Findings in this report are based on a cross-sectional telephone survey conducted between October 1993 and June 1994 as part of a multisite demonstration project for cancer prevention and control. The survey was conducted in eight U.S. cities identified via census data as having relatively high concentrations of targeted Latino subgroups. The analysis included 1499 Latino men aged > or = 40 who self-identified as Central American, Cuban American, Mexican American, or Puerto Rican. RESULTS: Overall, 53% of the sample reported ever having had a DRE and 68% reported ever having heard of the procedure. For all subgroups, the only significant predictor for obtaining a DRE was "ever heard of DRE." "Having your doctor discuss DRE" was a significant factor for Mexican Americans and Puerto Ricans. CONCLUSIONS: The lack of a universal DRE cancer-screening model among Latino groups highlights the need to address barriers in the context of the population's diversity. Ecologic approaches and clinician communication with Latinos need to be tailored to accommodate subgroup differences in knowledge, attitude, and practices related to DRE.

Adult↗

PubMed2002

Parental occupation and neural tube defect-affected pregnancies among Mexican Americans.

In a case-control study, we examined whether parental occupational exposures were related to neural tube defect (NTD)-affected pregnancies among Mexican Americans living along the Texas-Mexico border. Case women were 184 Mexican-American women with NTD-affected pregnancies; control women were 225 study-area residents who delivered normal babies during the same period as the case women. The women were interviewed in person about maternal and paternal occupations and work exposures during the periconceptional period. Compared with control women, case women were more likely to have had occupational exposures to solvents (odds ratio [OR], infinity; 95% confidence interval [CI], 2.4-infinity) and also were more likely to have worked in cleaning (OR 9.5; 95% CI, 1.1 to 82.2) or health care occupations (OR 3.0; 95% CI, 1.0 to 9.0) than control women. No compelling associations were found between paternal work exposures or occupations and NTDs in offspring in this population.

Adult↗

PubMed2002

Blood folate levels on the Texas-Mexico border.

The Texas-Mexico border population has a high prevalence of neural tube defects (NTDs). In 1998, in an effort to reduce the risk of NTD-affected pregnancies, the US Food and Drug Administration mandated folic acid fortification of enriched grain products. Since then, the median serum folate and red blood cell (RBC) folate levels of US women aged 15 through 44 years has risen. During 1995 through 2000, serum and RBC folate levels of 170 Mexican American women residing on the Texas-Mexico border who had delivered live, normal infants within the previous 3 months were tested. The median serum folate levels rose 46%, and RBC folate levels rose 44%. The increase suggests that food fortification may be affecting folate levels among populations with economic and cultural barriers to consuming fortified foods. However, more data are needed before we can assess the impact of food fortification on NTD rates on the border.

Adolescent↗

PubMedDate not supplied

Exposure to polychlorinated biphenyls and risk of neural-tube defects in a Mexican American population.

The authors examined the association between maternal polychlorinated biphenyl (PCB) levels and risk of neural tube defects (NTDs) in Mexican American women with NTD-affected pregnancies who resided in the 14 Texas-Mexico border counties during 1995-2000 (cases). Controls were randomly selected from study area women delivering normal live births. For PCB congeners with sufficient numbers of detectable values (PCB 99, 101, 110, 118, 138, 153, 180), there was little association between the proportions with detectable PCB levels in cases and controls. Odds ratios were <1 or compatible with the null, but power was low for some congeners. An index of seven PCB congeners (105, 118, 138, 153, 170, 180, 194) was also not associated with NTD risk. The maternal serum PCB levels in this study population (median PCB 153 level: 18 ng/g) were comparable to those with background exposure and do not appear to have contributed to the high prevalence of NTDs in this population.

Adult↗

PubMedDate not supplied

Linking environmental hazards and birth defects data.

The authors describe methods for linking birth certificate and birth defect registry data to potential environmental hazards and assess potential confounding factors. Cases of selected birth defects from the Texas Birth Defects Registry were linked to their respective birth/ fetal death records. Comparison births were randomly selected from the 1996-2000 Texas birth records. Maternal addresses were related through a geographic information system to boundaries of hazardous waste sites and point locations of industries. Approximately 89% of maternal addresses of case births and 88% of comparison births were successfully related in distance to these sites and industries. Maternal characteristics associated with living within one mile of these sites included belonging to any group besides non-Hispanic white and having lower education attainment (< 16 years) or a residence within the city limits. In linking environmental and health outcome databases, researchers should be aware of factors that may confound associations between exposure and outcomes.

Adult↗