Biomedical subjects

L Suarez

Publications and source records attributed to L Suarez.

At least 19 recordsLinked to original sources

PubMed2003

Low-grade parasitaemias and cold agglutinins in patients with hyper-reactive malarious splenomegaly and acute haemolysis.

A cluster of 16 cases of hyper-reactive malarious splenomegaly (HMS) with severe, acute haemolysis, from an isolated, Venezuelan, Yanomami population, was prospectively investigated. Nine (69%) of the 13 HMS sera investigated but only one (7%) of 14 control sera (P < 0.005) contained elevated titres (of at least 1:32) of complement-fixing IgM cold agglutinins (CA). The CA detected had specificity for both the I and i blood-group antigens (with a relative predominance of anti-I) and wide thermal stability. The mean reciprocal CA titre was much higher for the HMS sera than for the control samples (59.16 v. 2.28; P < 0.001). Indirect tests for antiglobulin were positive for two of the 13 HMS cases (but none of 14 controls) investigated; all of the direct tests for antiglobulin gave negative results. The seven HMS cases checked, using an assay based on a nested PCR which amplified species-specific ribosomal sequences from Plasmodium vivax or P. falciparum, each yielded the PCR product that indicated P. vivax infection. However, only six (25%) of the 24 control samples (collected, at the same time as the HMS samples, from asymptomatic adults from the same Yanomami population) were PCR-positive (P < 0.001). In some cases at least, the acute severe episodes of haemolysis occasionally seen in HMS appear to be associated with an auto-immune, cold-agglutinin-mediated response triggered by non-patent parasitaemias.

Adult↗

PubMed2001

Effects of hyperinsulinemia and obesity on risk of neural tube defects among Mexican Americans.

Although both maternal obesity and diabetes mellitus increase the risk for neural tube defects, it is unknown whether they are independent risk factors or manifestations of an underlying prediabetic state such as hyperinsulinemia. We investigated whether hyperinsulinemia was a risk factor for neural tube defects independent of obesity and hyperglycemia in Mexican-American women. We identified case and control women from residents delivering or terminating pregnancies in hospitals or birthing centers in any of the 14 Texas-Mexico border counties during 1995-2000. Case women had a pregnancy affected by anencephaly, spina bifida, or encephalocele; randomly selected control women had normal births, frequency matched by year and birth facility. Questionnaire and laboratory values obtained 5-6 weeks postpartum were available for 149 case and 178 control women. Both hyperinsulinemia and obesity were related to increased neural tube defect risk [odds ratio (OR) = 1.91, 95% confidence interval (CI) = 1.21-3.01 and OR = 1.73, 95% CI = 1.03-2.92, respectively]. Adjustment for obesity only slightly reduced the effect of hyperinsulinemia (OR = 1.75, 95% CI = 1.09-2.82). Alternatively, a modest effect remained for obesity after adjustment for hyperinsulinemia (OR = 1.45, 95% CI = 0.84-2.51). Hyperinsulinemia is a strong risk factor for neural tube defects and may be the driving force for the observed risk in obese women.

Adult↗

PubMed2001

Cigarette smoking behavior among US Latino men and women from different countries of origin.

OBJECTIVES: This study sought to compare smoking behavior among Latino men and women from different countries of origin. METHODS: A telephone-administered survey was conducted in 8 cities with Latino men and women of different national origin living in census tracts with at least 70% Latino individuals. RESULTS: A total of 8882 participants completed the survey; 53% were women. The average age of respondents was 44 years; 63% were foreign-born, and 59% preferred Spanish for the interview. Current smoking was more prevalent among men (25.0%, 95% confidence interval [CI] = 23.7, 26.3) than among women (12.1%, 95% CI = 11.1, 13.0). Smoking rates were not significantly different by national origin among men, but Puerto Rican women had higher rates of smoking than other women. Central American men and women had the lowest smoking rates. Foreign-born respondents were less likely to be smokers (odds ratio [OR] = 0.77, 95% CI = 0.66, 0.90) than US-born respondents, and respondents with 12 years or less of education had an increased odds of smoking (OR = 1.17, 95% CI = 1.01, 1.35). High ac culturation was associated with more smoking in women (OR = 1.12, 95% CI = 1.00-1.25) and less smoking in men (OR = 0.86, 95% CI = 0.78-0.95). Puerto Rican and Cuban respondents were more likely to be current smokers and to smoke more than 20 cigarettes per day. CONCLUSIONS: Older, US-born, and more-educated respondents were less likely to be current smokers. Respondents of Puerto Rican and Cuban origin were more likely to smoke. Acculturation has divergent effects on smoking behavior by sex.

Acculturation↗

PubMed2000

Neural tube defects among Mexican Americans living on the US-Mexico border: effects of folic acid and dietary folate.

Populations of Mexican descent have high occurrences of neural tube defects (NTDs). A recent study suggested that folic acid supplements may not protect these populations from NTDs. In a case-control study, the authors investigated the role of folic acid and dietary folate intake in NTD risk among Mexican Americans living along the Texas-Mexico border. From January 1995 to February 1999, 148 Mexican-American women with NTD-affected pregnancies and 158 women with normal live births were interviewed in person about use of vitamin supplements and dietary intakes during a 6-month periconceptional period (from 3 months before conception to 3 months after conception). Daily preconceptional consumption of vitamin supplements containing folic acid was 2.5% in control women and 2.0% in case women (odds ratio = 0.77; 95% confidence interval (CI): 0.19, 3.22). With adjustment for maternal age, education, obesity, and previous stillbirth or miscarriage, the risk estimate was essentially null (odds ratio = 1.12; 95% CI: 0.22, 5.78). Combined folic acid intake from diet and supplements showed only a modest risk reduction for intakes of > or = 1.0 mg per day (adjusted odds ratio = 0.73; 95% CI: 0.31, 1.72). The fact that the primary folic acid exposure was in the form of dietary polyglutamates rather than the more easily absorbed supplemental monoglutamates may explain an apparent decreased effect in this population.

Adult↗

PubMed2000

Investigation of folate pathway gene polymorphisms and the incidence of neural tube defects in a Texas hispanic population.

Neural tube defects (NTDs) are multifactorial in their etiology, having both genetic and environmental factors contributing to their development. Recent evidence demonstrates that periconceptional supplementation of the maternal diet with a multivitamin containing folic acid significantly reduces the occurrence and recurrence risk for having a pregnancy complicated by NTDs. Unfortunately, the mechanism underlying the beneficial effects of folic acid remains unknown. NTD surveillance data from the Texas-Mexico border show that the high NTD rate (28/10,000 live births) noted during the 1990-1991 Cameron county NTD cluster was superimposed on a background Cameron county NTD rate (16/10,000 live births) which is considerably higher than that generally noted in the United States (8-10/10,000 live births). These data suggest that genetic factors as well as transient environmental factors may contribute to the etiology of the NTDs. Furthermore, clinical and experimental evidence imply that allelic forms of genes involved with folate metabolism and/or transport may explain some of the observed variation in the NTD rates found across different populations. Two folate pathway genes were selected for evaluation in this study. The loci investigated included two known alleles of the 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene, as well as the promoter region of the folate receptor-alpha (FR-alpha) gene. Odds ratios (ORs) for the C677T polymorphism in the MTHFR gene were 1.8 (CI 0.47-6.8) for heterozygosity and 1.8 (CI 0.35-9.4) for homozygosity for the mutant 677T allele, relative to wildtype homozygotes. The odds ratio for the heterozygosity for the A1298C polymorphism in the same gene was 1.1 (CI 0.09-14). No individuals homozygous for the 1298C allele were observed. The OR for heterozygosity of FR-alpha gene polymorphisms detected at nucleotide 762 and at nucleotides 610/631 was 1.4 and 0.7, respectively. Neither of the FR-alpha polymorphisms was observed in the homozygous condition. No statistically significant associations were observed for any of the polymorphisms examined, as the 95% confidence intervals for all of the ORs included one. However, the frequency of the MTHFR 677T allele in the largely Hispanic control group from Texas was significantly different from other populations (P < 0.005), and among the highest reported for any control populations examined.

Adult↗

PubMed2000

Social networks and cancer screening in four U.S. Hispanic groups.

BACKGROUND: Evidence shows that social relationships play an important role in health and health behavior. We examined the relationship between social networks and cancer screening among four U.S. Hispanic groups. METHODS: We used telephone surveys to collect data in eight U.S. regions that have concentrations of diverse Hispanic-origin populations. We interviewed 8903 Hispanic adults, for a response rate of 83%; analysis was restricted to the 2383 women aged > or =40. As a measure of social integration, we formed a social network index from items on the number of close relatives and friends, frequency of contact, and church membership. We used logistic regression to estimate the effects of social integration on screening, adjusting for sociodemographic factors. RESULTS: Among Mexican, Cuban, and Central-American women, the effect of social integration on mammography screening was slight. The odds ratios (OR) per unit change in social integration category ranged from 1.16 to 1.22 with confidence intervals (CI) that overlapped with the null. For Pap smear screening, the effect was strongest among Mexican-American women (OR=1.44, 95% CI=1.21 to 1.72), but also evident among Central-American women (OR=1.22, 95% CI=0.72 to 2.06) and Cuban women (OR = 1.25, 95% CI = 0.81 to 1.93). Among Puerto Rican women, social integration had no effect on either mammography (OR=1.03) or Pap smear screening (OR=1.08). CONCLUSIONS: Independent of socioeconomic factors, social integration appears to influence cancer screening participation of Hispanic women. The modest effect is not universal across Hispanic groups and was stronger for Pap smear than for mammography screening behavior. Researchers should recognize Hispanic group differences in social network characteristics and the potential of social networks to change screening behavior.

Adult↗

PubMed2000

Breast cancer screening in regional Hispanic populations.

Although Hispanics' use of breast cancer screening services has been investigated, to date there have been no published studies of distinct Hispanic populations in different areas of the country. Using the diverse populations and sites involved in the National Hispanic Leadership Initiative on Cancer 'En Acción', this study examines ethno-regional differences in breast cancer screening rates among these groups and explores the correlates of screening participation. Data collected through telephone surveys were analyzed for women 40 years of age and older (n = 2082). After controlling for demographic variables traditionally related to breast cancer screening rates, it was found that ethno-regional differences in breast cancer screening practices clearly persisted. In addition to traditional demographic factors, other variables evidently underlie differences in Hispanics' utilization of breast cancer screening services. These variables may be cultural and should be investigated in future research. Meanwhile, researchers should not refer to the 'Hispanic' population at large without identifying, addressing and clarifying the ethno-regional characteristics of their samples.

Adult↗

PubMed2000

Texas physician immunization practices.

INTRODUCTION: Immunization levels among young children could be improved if physicians administered immunizations at both well and urgent visits, provided simultaneous vaccinations, and knew the guidelines on valid contraindications, part of the Standards for Pediatric Immunization Practices (Standards). We report on a survey measuring the immunization knowledge and practice of Texas pediatricians, family practitioners, and general practitioners. METHODS: A survey was mailed to a random sample of physicians. Questionnaire items covered 8 of the 18 Standards. RESULTS: The response rate was 62% (608 of 976 eligible physicians). The mean summary adherence-to-Standards score was 4.1 for pediatricians, 3.6 for family practitioners, and 3.0 for general practitioners. Specialty and practice location were significant predictors of the summary score, whereas gender, managed-care participation, and graduation year were not. DISCUSSION: Our study results suggest that in Texas, pediatricians and rural physicians most often adhere to the Standards. Improving the reimbursement level of administrative costs for immunization delivery, educating physicians on the Standards, and encouraging the use of patient immunization tracking systems are actions that could potentially improve immunization rates.

Adult↗

PubMed2000

Prevalence and risk factors of drug-resistant tuberculosis along the Mexico-Texas border.

OBJECTIVES: This study determined factors associated with drug resistance among 3496 patients with tuberculosis who resided in Texas counties along the Mexican border. METHODS: Univariate and logistic regression analyses were performed to identify risk factors associated with drug resistance. RESULTS: Among patients with a history of previous tuberculosis, being 19 years or younger was the only factor associated with multiple drug resistance. Female sex, being 20 to 39 years of age, and foreign birth were risk factors for resistance among patients with no history of previous tuberculosis. CONCLUSIONS: Factors contributing to drug resistance among Hispanic tuberculosis patients along the Texas-Mexico border may differ from those among other populations in the United States.

Adult↗

PubMed1999

Epidemiology of drug-resistant tuberculosis in Texas.

During 1987-1996, over 22,000 tuberculosis cases were reported in Texas, at an average annual incidence rate of 12.5 cases per 100,000 population. Counties with the highest rates were located along the Mexico-Texas border and in northwestern Texas. Nine percent of cases were resistant to at least one of the five first-line antituberculosis drugs used for treatment. Almost 5 percent (4.6%) were resistant to isoniazid, either alone or in combination with other antibiotics; 2.3% were resistant to rifampin; and only 1.3% were resistant to both isoniazid and rifampin. Being a recurrent case, being foreign-born, being 20-39 years of age, and residing in a Mexico-Texas border county were independent risk factors for isoniazid resistance and rifampin resistance. Tuberculosis patients with human immunodeficiency virus (HIV) infection were more likely to have rifampin resistance and less likely to have isoniazid resistance than patients without HIV infection. Factors associated with multi-drug-resistant tuberculosis included a history of previous tuberculosis (relative risk (RR) = 4.91, 95% confidence interval (CI) 3.5-6.8), non-US birth (RR = 2.69, 95% CI 2.1-3.5), age younger than 20 years (RR = 1.97, 95% CI 1.1-3.5), age 20-39 years (RR = 1.82, 95% CI 1.3-2.6), and residence in a Mexico-Texas border county (RR = 2.33, 95% CI 1.8-3.1).

AIDS-Related Opportunistic Infections↗

PubMed1998

When acculturation hurts: the case of immunization.

The study examined the relationship between the acculturation of Mexican American mothers in Texas and immunization status of their children between 3 and 24 months of age. Mothers' acculturation, demographic characteristics, and immunization status of their children were assessed in in-person interviews with a sample of Mexican American respondents representative for Texas (n = 2193). Acculturation was measured with ten scales assessing oral and written language use, proficiency, and preference, music and TV viewing preferences, ethnic identity, place where a person was reared, and contacts with Mexico. Immunization status, defined according to the recommendation of the CDC Advisory Committee on Immunization Practices, was determined from official shot records obtained directly from respondents or, for respondents without records, obtained from their health care providers. Regression analysis revealed that acculturation significantly contributed to inadequate immunization status, even when socioeconomic status and other demographic covariates of acculturation were statistically controlled. Mediational analysis revealed that acculturation contributed to inadequate immunization through less positive attitudes toward immunization, a diminished sense of parental responsibility for children's immunization, and more perceived barriers to immunization. It is concluded that culture-specific beliefs encouraging childhood immunization should be fostered among Mexican Americans.

Acculturation↗

PubMed1998

Family characteristics and behavior problems of suicidal and non-suicidal children and adolescents.

The present study examined familial and individual variables in youngsters at high risk for suicide and non-suicidal youngsters. One hundred inpatient children and adolescents completed a battery of questionnaires including, FACES II, Family Strengths, and Problem Behavior Scales, to assess family dysfunction and individual behavior problems. The results indicated that suicidal youngsters have lower pride in their families and perceived them as less adaptable than non-suicidal youngsters as indicated by scores on the Family Strengths and FACES II, respectively. Scores on the Problem Behavior Scales indicated that suicidal youngsters also exhibited self-inflicted behaviors, withdrawal from others, little interest in activities, poor concentration, and difficulties with sleeping. In addition, youths at risk for suicide were more likely to be diagnosed with a mood disorder, including major depressive disorder and dysthymia, as well as substance abuse and phobias. These findings suggest that suicidal youngsters' negative perceptions of their families and their maladaptive behaviors should be given special attention in designing appropriate interventions. In this way, treatment would likely be effective by providing appropriate coping skills and preventing future suicidal attempts in high risk youngsters.

Adolescent↗

PubMed1998

Language differences in interpretation of breast cancer health messages.

BACKGROUND: Little is known about how women interpret terminology used in breast cancer messages. The authors assessed the understanding of common cancer terms and whether understanding differed by language of interview. METHODS: In interviews, low-income women 50 years old or older were asked open-ended questions about the meanings of specific terms and phrases in commonly used health messages. RESULTS: Of 232 completed interviews, 167 were conducted in English and 65 in Spanish. Both English- and Spanish-speaking women poorly understood the terms "risk factors," "at risk," and "cancer." Spanish speakers were less likely to provide technical definitions of "diagnosed" and "mammogram" and had different interpretations of several cancer terms compared with English speakers. CONCLUSIONS: Cancer terms mean different things to English and Spanish speakers. Client education could be vastly improved if these cultural differences in interpretation were addressed.

Aged↗

PubMed1998

Concerns and dilemmas of Hispanic AIDS information seekers: Spanish-speaking callers to the CDC National AIDS hotline.

Hispanic communities suffer disproportionately from the impact of human immunodeficiency virus infection (HIV). Each year, thousands of Spanish-speaking Hispanics call the Centers for Disease Control and Prevention National AIDS Hotline to ask questions about HIV. During 1995 alone, Spanish line staff answered more than 29,000 calls. This article presents a profile of callers and their concerns based on a systematic sample of these calls (N = 6,933) and qualitative data. The authors triangulated quantitative and qualitative results to provide a deeper understanding of the issues and dilemmas discussed with callers. Males and females called in equal numbers, but significant gender differences were observed in both situational and content variables. Gender roles, cultural values, and anxiety strongly affect the way that callers approach information and prevention. Findings suggest that health educators need to carefully examine whether prevention programs will reinforce or challenge traditional gender roles, sexual norms, and cultural values.

Acculturation↗

PubMed1997

Hopelessness in inpatient youths: a closer look at behavior, emotional expression, and social support.

OBJECTIVE: To examine the individual and family characteristics of children and adolescents with high levels of hopelessness. METHOD: One hundred inpatient youngsters participated in the study. Several measures, including the Hopelessness Scale for Children, Problem Behavior Scale of the Scales of Independent Behavior, Social Support Questionnaire-Revised, Pediatric Anger Expression Scale, and Differential Emotions Scale, were used to compare differences between youngsters who scored high or low on hopelessness. RESULTS: The results indicated that youngsters with high hopelessness scores tended to perceive their families and peers as providing little support, to express their anger overtly and aggressively, and to demonstrate more negative emotions than youngsters with low hopelessness scores. CONCLUSIONS: Hopelessness in youths appears to be associated with a specific pattern of behavioral and emotional problems. Clinical implications of the findings include integrating anger management, emotional expression interventions, and involving the family in treatment to enhance the social support network of youngsters with high levels of hopelessness.

Adolescent↗

PubMed1997

Errors and correlates in parental recall of child immunizations: effects on vaccination coverage estimates.

OBJECTIVE: We evaluated the accuracy of parental recall of children's immunization histories as compared with provider records and examined how errors in parental recall correlate with sociodemographic characteristics. DESIGN: The validation study was part of a population-based household survey designed to assess immunization levels among Texas children under age 2 years. For 72% (n = 3278), interviewers used vaccination records from the parent to copy dates for the diphtheria and tetanus toxoids and pertussis vaccine (DTP), oral polio vaccine (OPV), and measles, mumps, and rubella (MMR) shots. For parents without shot records (n = 1216), interviewers asked about each vaccine, whether the child had received the shot, how many, and at what age. Of these, 85% (n = 1029) were validated with health provider records. RESULTS: Measured against provider records, only 34% of parents accurately recalled the number of DTP shots a child had. More often (42%) parents underestimated the number of DTP shots than overestimated (24%). Agreement between parental recall and provider records was high (83%) for the single dose of MMR. Accuracy of parents' recall did not differ by race/ethnicity, education level, or type of health insurance coverage, but decreased as child's age increased. Having a vaccination record at home was associated with a higher immunization status. Hispanic, lower educated, and uninsured parents were more likely to have a vaccination record than non-Hispanic, higher educated, and privately insured parents. DISCUSSION: Validity of parental recall of children's immunization histories depends on the vaccine and the age of the child, which is highly correlated with the number of shots parents must recollect. Results suggest that inclusion of parent recall information from vaccination surveys underestimates DTP:OPV:MMR coverage. This underestimation is consistent across economic and race/ethnic groups. Thus, community surveys based on cards and recall should provide reliable conclusions about which groups need intensive program efforts. For the routine monitoring of vaccination coverage, reasonable estimates can be obtained by combining parent-held record and parent recall data. Caution is required when comparing coverage estimates from different surveys since the source of information and method of derivation will produce widely varying coverage rates.

Black or African American↗

PubMed1997

The impact of public assistance factors on the immunization levels of children younger than 2 years.

OBJECTIVES: This study examined how children's immunization status varied with enrollment in the Women, Infants, and Children (WIC); Aid to Families with Dependent Children (AFDC); food stamp; and Medicaid programs. METHODS: A statewide survey was used to determine the percentage of children less than 2 years of age who were up to date for diphtheria, tetanus, and pertussis; polio; and measles, mumps, and rubella vaccines. RESULTS: WIC and uninsured children were more likely and AFDC and Medicaid children less likely to be up to date than others. CONCLUSIONS: The higher immunization status of WIC and uninsured children suggests that integrating immunization practices with government programs may be effective.

Aid to Families with Dependent Children↗

PubMed1996

Use of Texas birth certificate data to predict measles immunization status.

Inadequate immunization has been a major cause of epidemic measles, but risk factors for inadequate immunization are poorly characterized. By using measles data bases and computerized birth certificate files, we identified a retrospective cohort of 1,070 Texas-born children who were aged 15 months to 10 years when they had measles during the 1988 to 1991 epidemics. We used measles and birth certificate data, including prenatal care and demographic information, to determine immunization status and risk factors for inadequate measles immunization. Risk factors predicting lack of immunization in children with measles in stepwise logistic regression were black ethnicity, urban residence, poor prenatal care, preschool age, and an unknown father. Birth certificates contain information that can predict inadequate measles vaccination and should be evaluated prospectively.

Birth Certificates↗