Biomedical subjects

Rafael Flores

Publications and source records attributed to Rafael Flores.

11 recordsLinked to original sources

PubMed2006

Exposure to a nutrition supplementation intervention in early childhood and risk factors for cardiovascular disease in adulthood: evidence from Guatemala.

To study the role of nutrition in the association of birth size and childhood growth with development of cardiovascular disease, the authors in 2002-2004 surveyed 665 men and 790 women aged 25-42 years who had been exposed as children to a community-randomized nutrition supplementation intervention in four villages in eastern Guatemala. Exposure was associated with a lower fasting glucose level (7.0 mg/dl, 95% confidence interval (CI): 0.5, 13.5) for exposure at ages 36-72 months; lower systolic blood pressure (3.0 mmHg, 95% CI: 0.4, 5.6) for exposure at ages 24-60 months; and a lower triglyceride level (sex-adjusted; 22.2 mg/dl, 95% CI: 0.4, 44.1) and higher high density lipoprotein cholesterol level (males only; 4.7 mg/dl, 95% CI: 1.5, 7.9) for exposure prior to age 36 months. Improved nutrition at any age prior to 7 years was not associated with diastolic blood pressure, total or low density lipoprotein cholesterol level, or prevalence of the metabolic syndrome. Interventions designed to address nutrient deficiencies and ameliorate stunting that are targeted at pregnant women and young children are unlikely to increase cardiovascular disease risk later in life and may instead lower the risk.

Adult↗

PubMed2005

In vivo imaging platform for tracking immunotherapeutic cells.

Cellular therapeutics show great promise for the treatment of disease, but few noninvasive techniques exist for monitoring the cells after administration. Here we present a magnetic resonance imaging (MRI) technology that uses perfluoropolyether (PFPE) agents to track cells in vivo. Fluorine MRI selectively images only the labeled cells, and a 'conventional' (1)H image places the cells in their anatomical context. We labeled phenotypically defined dendritic cells (DCs) with PFPE ex vivo and observed efficient intracellular uptake of the PFPE with little effect on DC function. We injected labeled DCs into tissue or intravenously in mice and then tracked the cells in vivo using (19)F MRI. Although we focused on DCs, which are being developed as immunotherapeutics for cancer and autoimmune diseases, this technology should be useful for monitoring a wide range of cell types in vivo.

Cells, Cultured↗

PubMed2005

Separation of proteins with a molecular mass difference of 2 kDa utilizing preparative double-inverted gradient polyacrylamide gel electrophoresis under nonreducing conditions: application to the isolation of 24 kDa human growth hormone.

A method for separating proteins with a molecular mass difference of 2 kDa using SDS-PAGE under nonreducing conditions is presented. A sample mixture containing several human growth hormone (hGH) isoforms was initially separated on a weak anion-exchange column. Fractions rich in 24 kDa hGH as determined by analytical SDS-PAGE were pooled and further separated by cation-exchange chromatography. The fractions pooled from the cation-exchange chromatography contained two hGH isoforms with a 2 kDa molecular mass difference according to SDS-PAGE analysis, 22 and 24 kDa hGH. The 22 and 24 kDa hGH were separated using continuous-elution preparative double-inverted gradient PAGE (PDG-PAGE) under nonreducing conditions. The preparative electrophoresis gel was composed of three stacked tubular polyacrylamide matrices, a 4% stacking gel, a 13-18% linear gradient gel, and a 15-10% linear inverted gradient gel. Fractions containing purified 24 kDa hGH were pooled and Western blot analysis displayed immunoreactivity to antihGH antibodies. PDG-PAGE provides researchers with an electrophoretic technique to preparatively purify proteins under nonreducing conditions with molecular mass differences of 2 kDa.

Chromatography↗

PubMed2005

Early childhood development interventions and cognitive development of young children in rural Vietnam.

Little is known about the long-term benefits of interventions that aim to promote early childhood development programs. The goal of this research was to determine whether an early childhood development intervention added to a nutrition intervention during preschool ages had lasting effects on the cognitive development of school-age children in communes of Thanh Hoa province in rural Vietnam. The study focused on a total of 313 children aged 6.5-8.5 y (grades 1 and 2 in primary school) in 2 communes that were exposed to nutrition intervention or nutrition and early childhood development (ECD) intervention from 1999 to 2003. Measurements of height and cognitive test scores (Raven's Progressive Matrices Test) were collected from the children; household characteristics were determined by interviews with mothers. Longitudinal analysis was performed by integrating the data with that collected from the same children in past surveys. Significant effects of the ECD intervention compared with the nutrition intervention were detected. The beneficial effect of ECD intervention on the cognitive test scores was large for the most nutritionally challenged children whose height-for-age Z-scores declined or remained in the stunted range. The findings help provide useful insights into the development of an effective integrated model of ECD and nutrition intervention for children in rural Vietnam.

Body Height↗

PubMed2005

Rationale for a follow-up study focusing on economic productivity.

Past studies of nutrition, human capital formation, and economic productivity have been limited by the fact that biomedical researchers and economists work largely in isolation, with loss of complementarity. Biomedical researchers are faulted for not adequately addressing bias and measurement issues and for naive analyses and interpretation of results, whereas economists are criticized for using simplistic nutrition and physiological measures and for relying on statistical methods rather than experimental designs. To avoid these problems, a multidisciplinary team of biomedical investigators and economists undertook a follow-up study in 2002-04 of a cohort of young men and women, who participated as young children in a randomized community trial of nutrition supplementation carried out from 1969-77 Previous studies, particularly the original trial and a 1988-89 follow- up, are described to provide an overview of the data available for linkage with the 2002-04 follow-up. Key results from these earlier studies are reviewed but judged inconclusive because the data used were collected when many subjects were still growing and developing physically, in school, unmarried, and/or not yet settled into occupations. The subjects were 26 to 41 years of age in 2003, permitting a more complete assessment of human capital and economic productivity. The experimental design of the 1969-77 original study, 35 years of follow-up, use of robust methods of data collection, and the participation of a multidisciplinary team will likely lead to the most comprehensive assessment to date of the importance of nutrition for economic productivity.

Adult↗

PubMed2005

The human capital study 2002-04: tracking, data collection, coverage, and attrition.

Between 2002 and 2004, the Institute of Nutrition of Central America and Panama (INCAP), in collaboration with Emory University, the International Food Policy Research Institute (IFPRI), and the University of Pennsylvania, re-surveyed young Guatemalan adults who had, as children, been participants in a nutrition supplementation trial conducted by INCAP between 1969 and 1977. This "Human Capital Study 2002-04" complements and extends data obtained in previous studies by collecting new information on measures of physical health and well-being, schooling and cognitive ability, wealth, consumption and economic productivity, and marriage and fertility histories. This paper describes the study domains and data collection procedures. Among 2,393 members of the original sample, 1,856 (77%) were targets for enrollment. Response rates varied by gender, current place of residence, and domain of data collection, with 80% of males and 89% of females completing at least one data collection instrument. Attrition was not random and appears to be associated with a number of initial characteristics of individuals and their households that should be controlled for in future analyses. We conclude that data collection was successful and data quality is high, facilitating the successful undertaking of our planned investigation of important study hypotheses.

Adult↗

PubMed2005

Physical fitness, body composition, blood pressure, and blood metabolic profile among young Guatemalan adults.

We assessed the distribution of several risk factors related to health: muscular strength (handgrip strength), cardiovascular endurance (step test), flexibility (sit and reach test), anthropometry and body composition, blood pressure, fasting plasma glucose, lipid profile, and hemoglobin in a cohort of Guatemalan adults who were born in four rural villages between 1962 and 1977. By 2002 approximately 32% had migrated to Guatemala City or elsewhere in the country. Men are more physically fit and leaner than women. Fatness, poor physical fitness, and metabolic syndrome are highly prevalent in women living in both rural and urban areas. Risk profiles worsen with increasing age. Men who migrated to Guatemala City have lower physical fitness, greater fatness and systolic blood pressure, and worse lipid profile than men who still live in their original villages. Such a pattern was not evident in women, except that blood pressure was higher in urban women than in women who lived in their original villages.

Adult↗

PubMed2004

Conditional cash transfers are associated with a small reduction in the rate of weight gain of preschool children in northeast Brazil.

Programs providing cash transfers to poor families, conditioned upon uptake of preventive health services, are common in Latin America. Because of the consistent association between undernutrition and poverty, and the role of health services in providing growth promotion, these programs are supposed to improve children's growth. The impact of such a program was assessed in 4 municipalities in northeast Brazil by comparing 1387 children under 7 y of age from program beneficiary households with 502 matched nonbeneficiaries who were selected to receive the program but who subsequently were excluded as a result of quasi-random administrative errors. Anthropometric status was assessed 6 mo after benefits began to be distributed, and beneficiary children were 0.13 Z-scores lighter (weight-for-age) than excluded children, after adjusting for confounders (P = 0.024). The children's growth trajectories were reconstructed by copying up to 10 recorded weights from their Ministry of Health growth monitoring cards and by relating each weight to the child's age, gender, and duration of receipt of the program benefit in a random effects regression model. Totals of 472 beneficiary and 158 excluded children under 3 y of age were included in this analysis. Each additional month of exposure to the program was associated with a rate of weight gain 31 g lower than that observed in excluded children of the same age (P < 0.001). This failure to respond positively to the program may have been due to a perception that benefits would be discontinued if the child started to grow well. Nutrition programs should guard against giving the impression that poor growth will be rewarded.

Brazil↗

PubMed2002

Distance education with tutoring improves diarrhea case management in Guatemala.

OBJECTIVE: To evaluate the impact of distance education in diarrhea and cholera case management on the quality of physicians' and nurses' practice. DESIGN: The pre-post panel, program and control group design used trained physician observers to measure if doctors and nurses complied with case management standards. Extended observations and client exit interviews were used to analyze audience bias and the validity of counseling measurements. SETTING: Health care facilities in six districts of Guatemala. Ministries of Health in four Central American countries and the Institute of Nutrition for Central America and Panama implemented the course. STUDY PARTICIPANTS: The study panel consisted of 66 course graduates (program group) and 66 doctors and nurses who were interested in taking the course where the course was not offered (control group). RESULTS: The percentage of diarrhea cases assessed correctly and dehydration cases classified correctly increased by 25% more in the program group than in the control group, but post-course performance was still only approximately 60% in the program group. Rehydration treatment did not improve. Counseling improved insignificantly. Client exit interviews suggested that indicators for counseling may need to be re-examined for validity. No audience effect on health worker practice was found. Completion rates were high. The program cost 60 dollars US per enrollee. CONCLUSION: This is an effective, relatively low-cost program that substantially improved case management of diarrhea in Guatemala, in particular the quality of assessment and classification. However, many health workers who completed the course are still not performing to standard, so additional work is needed to resolve this problem.

Adult↗

PubMed2002

School height censuses are reliable and valid tools for small-area targeting of nutrition interventions in Honduras.

Nutrition program planners often need information on the relative burden of malnutrition in different communities, or administrative units, to decide where best to invest limited available resources. National nutrition surveys, however, rarely provide precise, representative findings at a finer level than that of large, subnational regions. The school height census is an alternative, low-cost approach that does provide disaggregated data on growth retardation at the local level. This study assessed the reliability and validity of the school height census for small-area targeting of nutrition interventions in Honduras. Reliability was assessed by examining the stability of small-area estimates of mean height-for-age Z-score over five consecutive years from 1993 to 1997. Validity was assessed by comparing municipality-level mean height-for-age Z-score in the 2001 school height census with the same parameter estimated in an anthropometric survey of children < 5 y old conducted in representative samples in 70 municipalities 3-7 mo earlier. The study found that stable estimates of mean height-for-age Z-score could be obtained at the level of municipalities or larger (intraclass correlation coefficients > or = 0.85). The school height census estimates of mean height-for-age Z-score at the municipality level were also valid, with the reference criterion the survey results for children > or = 1 y of age (Spearman's rank correlation = 0.74). School height censuses cannot provide reliable estimates of levels of growth retardation in individual schools. Wider use of school height censuses could make it much easier to identify communities that might benefit from targeted nutrition interventions.

Body Height↗

PubMedDate not supplied

Monetary incentives in primary health care and effects on use and coverage of preventive health care interventions in rural Honduras: cluster randomised trial.

BACKGROUND: Scaling-up of effective preventive interventions in child and maternal health is constrained in many developing countries by lack of demand. In Latin America, some governments have been trying to increase demand for health interventions by making direct payments to poor households contingent on them keeping up-to-date with preventive health services. We undertook a public health programme effectiveness trial in Honduras to assess this approach, contrasting it with a direct transfer of resources to local health teams. METHODS: 70 municipalities were selected because they had the country's highest prevalence of malnutrition. They were allocated at random to four groups: money to households; resources to local health teams combined with a community-based nutrition intervention; both packages; and neither. Evaluation surveys of about 5600 households were undertaken at baseline and roughly 2 years later. Pregnant women and mothers of children younger than 3 years old were asked about use of health services (primary outcome) and coverage of interventions such as immunisation and growth monitoring (secondary outcome). Reports were supplemented with data from children's health cards and government service utilisation data. Analysis was by mixed effects regression, accounting for the municipality-level randomisation. FINDINGS: The household-level intervention had a large impact (15-20 percentage points; p<0.01) on the reported coverage of antenatal care and well-child check-ups. Childhood immunisation series could thus be started more opportunely, and the coverage of growth monitoring was markedly increased (15-21 percentage points; p<0.01. Measles and tetanus toxoid immunisation were not affected. The transfer of resources to local health teams could not be implemented properly because of legal complications. INTERPRETATION: Conditional payments to households increase the use and coverage of preventive health care interventions.

Adolescent↗