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Noel W Solomons

Publications and source records attributed to Noel W Solomons.

At least 19 recordsLinked to original sources
PubMed2005

Bioimpedance electrical spectroscopy in the first six months of life: some methodologic considerations.

OBJECTIVES: The objectives of this study were to evaluate the feasibility of using multifrequency bioelectrical impedance spectroscopy (BIS) in newborns and first-semester infants and to assess the influence of diverse methodologic and biological factors on BIS measurements. METHODS: We studied 69 infants of both sexes, from the first day after birth through age 6 mo. They were healthy term infants who had no congenital malformations and were born in a low-income, peri-urban neighborhood of Guatemala City. The design was based on serial, repeated BIS measurements. RESULTS: Overall mean values of extra- and intracellular resistance (mean+/-standard deviation) were 470.0+/-73.3 Omega and 604.6+/-179.2 Omega, respectively. We found statistical differences in both resistances in relation to advancing age and degree of movement while taking the measurements. With respect to repeat measurements by two separate observers, interobserver differences were a non-significant 7.6 Omega for both resistances. Restraining the infants and previous consumption of milk or formula had a significant effect on extracellular resistance measurements. The mean standard errors of measurement was 4.5 Omega for extracellular resistance and 73.9 Omega for intracellular resistance. CONCLUSION: The BIS technique is feasible in newborn and young children when physiologic and methodologic aspects are respected or controlled.

Age Factors↗
PubMed2005

Ferritin concentrations in dried serum spots prepared by standard compared with simplified approaches: a validation study in Guatemala City.

BACKGROUND: Spot ferritin assay on dried serum spot (DSS) samples provides reliable and accurate assessment. Standard DSS preparations, however, involve precise serum aliquots and require some skill and training of field personnel. OBJECTIVE: We evaluated the validity of the spot ferritin assay on DSS samples prepared by simplified approaches and standard technique in Guatemala City. DESIGN: Venous blood (5 mL) was obtained from 104 subjects aged 24 +/- 15 y (x +/- SD) and transferred into nonheparin-containing (2 plain and 2 self-sealing) capillary blood collection tubes. Three DSS samples were prepared: A (standard, 20 microL serum), B (blot, approximately 30-35 mm serum column), and C (dispenser, 20 microL serum pushed directly from self-sealing capillary tubes with a dispenser). Spots were air-dried and placed in hermetic plastic bags with a desiccant. Two weeks later, entire spots for DSS A and C samples and a circle in the center for DSS B samples were analyzed. RESULTS: DSS ferritin A, B, and C correlated strongly with traditional ferritin (r = 0.71-0.88, P < 0.001). The geometric mean (-1 SD and +1 SD) values for the DSS A, B, and C and traditional ferritin methods were 27.5 (12.6, 60.2), 32.4 (13.5, 77.6), 27.5 (11.7, 64.6), and 30.2 (13.8, 66.1) microg/L, respectively, and did not differ significantly. The difference in ferritin values by various DSS approaches compared with the traditional approach was small (<4 microg/L; P > 0.05). CONCLUSIONS: Simplified and standard DSS methods provide accurate iron-status assessment in population studies. The simplified DSS approaches for serum ferritin measurement need to be evaluated further in populations in whom iron deficiency is prevalent.

Adult↗
PubMed2005

Day-to-day variations in iron, zinc and copper in breast milk of Guatemalan mothers.

OBJECTIVE: To assess the within-subject and between-subject coefficients of variation (CV) of iron, zinc and copper concentrations in the milk of Guatemalan mothers. METHODS: We performed a cross-sectional study in lactating women who had delivered a healthy infant 1 to 6 months previously in two low-income peri-urban areas (San Bartolome Milpas Altas and Ciudad Peronia) and a low-income rural area (San Juan Chamelco) in Guatemala. Women infested with Ascaris lumbricoides or Trichuris trichiura received a single dose of albendazole (400 mg) or placebo. Two weeks after treatment, milk samples were collected on 3 or 4 consecutive days. Trace element concentrations in milk were measured by inductively coupled plasma/atomic emission spectrometry. RESULTS: The instrumental error of the inductively coupled plasma/atomic emission spectrometry method, expressed as SD, was 0.04, 0.27 and 0.02 mg/L for iron, zinc and copper, respectively. Concentrations in milk samples collected from 47 mothers on 3 or 4 consecutive days, expressed as mean +/- SD, were 0.28 +/- 0.13, 2.03 +/- 0.37 and 0.29 +/- 0.07 mg/L for iron, zinc and copper, respectively. The within-subject CV was 46.1%, 18.2%, and 22.8% and the between-subject CV was 61.2%, 48.3% and 31.7% for iron, zinc and copper, respectively. Stage of lactation, infestation with intestinal parasites and residential area had a significant influence on milk zinc, copper and iron concentrations. CONCLUSIONS: One sample of milk is sufficient to give a reliable estimate of the zinc concentration in milk. Two samples taken on consecutive days are required for a reliable estimate of iron and copper concentrations.

Adolescent↗
PubMed2004

Classic dengue fever affects levels of circulating antioxidants.

OBJECTIVE: We studied alterations of circulating antioxidant nutrients in patients with classic dengue fever in the tropical lowlands of Guatemala. METHODS: In nine patients with dengue fever and 12 healthy Guatemalan control subjects, we assessed plasma concentrations of retinol, alpha-tocopherol, beta-carotene, glutathione, taurine, thiobarbituric acid-reactive species, and total antioxidant status. Control subjects were assessed twice within 48 h to account for day-to-day variations. Febrile patients with dengue fever were examined on the day of admission to the hospital, at discharge after defervescence (approximately 5 d after admission), and 7 d thereafter. RESULTS: In patients with dengue fever, increases in plasma concentrations of retinol and beta-carotene were seen, whereas decreases were observed for glutathione and total antioxidant status. As compared with the reference group, patients with dengue fever had lower retinol concentrations in the acute phase of the disease and lower glutathione concentrations 7 d after discharge. Further, thiobarbituric acid-reactive species levels were higher in the dengue fever patients as analyzed by unpaired t test. CONCLUSION: Using dengue fever as a model for the metabolic response to an acute, self-limited tropical viral infection, the present findings suggest slight turbulence of the antioxidant system that may be a response to or a consequence of the viral inflammatory process.

Adult↗
PubMed2004

Use of the deuterated-retinol-dilution technique to monitor the vitamin A status of Nicaraguan schoolchildren 1 y after initiation of the Nicaraguan national program of sugar fortification with vitamin A.

BACKGROUND: Nicaragua initiated a national program of vitamin A fortification of its domestic sugar supply starting with the 1999-2000 sugarcane harvest. OBJECTIVE: This study was conducted to document any change in the vitamin A status of a cohort of children during the first year of the program. DESIGN: The vitamin A status of 21 Nicaraguan schoolchildren (mean age: 6.7 y; range: 5.3-9.3 y) was assessed in March 2000 and in March 2001. Total-body vitamin A stores and liver vitamin A concentrations were estimated with the deuterated-retinol-dilution (DRD) technique at a dose of 5 mg [(2)H(4)]retinyl acetate at baseline and 5 mg [(2)H(8)]retinyl acetate during the repeat test 1 y later. Plasma retinol and carotenoids were measured by HPLC. RESULTS: Median total-body vitamin A stores increased from 0.33 to 0.72 mmol (P = 0.0001), liver vitamin A concentrations from 0.52 to 0.78 mumol/g (P = 0.0003), and plasma retinol concentrations increased from 0.97 to 1.17 mumol/L (P = 0.01). CONCLUSION: The vitamin A status of Nicaraguan schoolchildren improved during the year after the initial distribution of vitamin A-fortified sugar in Nicaragua.

Body Height↗
PubMed2004

Weight of foods and number of portions consumed are not proxies for expressing nutrient intakes in field studies.

In order to determine whether simplified indicators for usual consumption of selected food groups, specifically those derived from either the percentage of the number of daily portions, the percentage of total daily weight consumed, or both, could serve as proxies for the conventional expression of daily energy intake, these indicators were computed and compared from food-frequency data in a data set. Food consumption was reported in frequency categories and portion sizes per month, per week, or per day, and the cumulative sum was divided by 365 to provide a daily average. The survey was done in the township of Santa Cruz and three hamlets of a rural county seat in Guatemala. Data from food-frequency questionnaires from 269 individuals (55 men and 214 women aged 16 to 86 years) were analyzed. For foods of plant origin, the percentage of total energy, percentage of total food weight, and percentage of total number of portions consumed showed low correlations (r < .45). When subdivided into specific foods and food groups (fruits and vegetables, red meat, etc.), marked differences were revealed across sites and among different indicators of consumption. Despite the simplicity of calculation, neither the percentage of weight of food in a group nor the percentage of portions consumed could serve reliably as proxies for their contributions to the percentage of total energy in this rural population in Guatemala.

Adolescent↗
PubMed2004

[Harmonization for mesoamerican nutrient-based recommendations: regional unification or national specification?].

Mesoamerica, the area we focus for this paper, is a section of Latin America that extends from Central Mexico to Panama. The deliberations of international committees are the primary bases for their nutrient-based recommendations. To a smaller extent, the unique particularities of the bioavailability for one or another nutrient have been considered. The nutrient recommendations throughout the region are "relatively" uniform and mutually consistent with respect to: iron, iodine and most of the B-complex vitamins. discrepancies exist among the various sets of recommendations for other nutrients. A valid basis of harmonization would not be unification of recommendations across all nationalities, but rather assuring a consistency in the nutrient profile that is recommended provides the nutrient exposures and/or fills the body's reserves as best suits the goals of survival, growth, well-being and function within the ecological niche of the population. That the recommendations for nutrients must be satisfied from foods, foods that are accessible and culturally acceptable, and that approximate the parallel demands of food-based dietary guidelines, add additional constraints onto the process of enunciating the former.

Adolescent↗
PubMed2003

Quantitative assessment of total body stores of vitamin A in adults with the use of a 3-d deuterated-retinol-dilution procedure.

BACKGROUND: The conventional deuterated-retinol-dilution (DRD) technique provides a quantitative estimate of total body stores of vitamin A in humans. The procedure requires equilibration of serum deuterated retinol with nondeuterated retinol after administration of an oral dose of deuterated vitamin A. Equilibration takes approximately 3 wk to complete. OBJECTIVE: Our goal was to develop a predictive mathematical formula for quantitative assessment of total body stores of vitamin A in adults by using a procedure that takes less time to perform because serum isotope equilibration is not required, so that blood drawing can be done 3 d, instead of approximately 3 wk, after isotope dosing. DESIGN: Ratios of serum deuterated to nondeuterated retinol (D:H retinol) were determined in Filipino adults (n = 68) 3 and 20 d after an oral dose of 0.015 mmol [(2)H(4)]retinyl acetate and in Guatemalan adults (n = 15) 3 and 21 d after a 0.030-mmol dose. D:H retinol values 20 or 21 d after the isotope dose were used in a mathematical formula to obtain quantitative estimates of total body stores of vitamin A that were then correlated with serum D:H retinol values 3 d after the isotope dose. RESULTS: The relation between these variables was nonlinear and was described by the following equation: total body stores of vitamin A (in mmol retinol) = 0.00468 x 10(37(isotope dose in mmol))/D:H retinol in serum 3 d after the isotope dose. CONCLUSION: A 3-d DRD technique could be used for quantitative assessment of total body stores of vitamin A; this technique takes less time than does the conventional DRD technique.

Administration, Oral↗
PubMed2003

Introduction to the proceedings of the International Research on Infant Supplementation (IRIS) Initiative.

In 2001, students and professionals from 13 nations were hosted by UNICEF for the International Workshop on Multi-Micronutrient Deficiency Control in the Life Cycle in Lima, Peru, May 30-June 1, 2001. Workshop participants engaged in both narrow and broad discussions of ways to combat multiple micronutrient deficiencies in developing countries. Preliminary data from four common-protocol studies conducted in Peru, South Africa, Indonesia, and Vietnam were presented. Participants also discussed the immediate, preliminary, and interim issues that could guide both policy and planning of future studies of multiple micronutrient deficiency. Among the studies highlighted was the International Research on Infant Supplementation (IRIS) I trial. A review of IRIS I yielded some confirmation of the efficacy using a crushable "foodlet" (i.e., cross between food and tablet) as a supplementation vehicle, as well as concerns about potential adverse consequences of nutrient-nutrient and nutrient-nutriture interactions. Other plenary topics illustrated the practical matters of how the IRIS I logistics and operations were built, and several focused on how to best design follow-up research on infant supplementation. Finally, a series of working groups allowed for in-depth discussions on the topics of community and policy, monitoring and implementation, and research. Researchers continue to try to identify efficient and effective programs suited to the low-income settings in which infant multi-micronutrient malnutrition occurs. The papers in these proceedings elaborate on several aspects of the IRIS study, and they are published in the hope that their analysis by readers will produce wider dissemination of the details of this devastating problem.

Child Nutrition Disorders↗
PubMed2003

The evolving applications of spreads as a FOODlet for improving the diets of infants and young children.

Action is needed to reduce the burden of micronutrient malnutrition in developing countries, and because low-income populations are vulnerable to deficiencies of multiple micronutrients, we need to move beyond approaches that comprise only single nutrients. The normal and evolutionary manner in which to consume nutrients is in the context of foods, both snacks and meals. Spreads are high-viscosity-fat products prepared by mixing dried powdered ingredients with a vegetable fat chosen for its viscosity. Spreads are not traditionally used for feeding infants or young children and were initially proposed as a way to treat children recovering from severe malnutrition. In preparation for the International Research Group on Infant Supplementation (IRIS) III intervention, a sequel to the IRIS I study (which was the focus of a workshop in Lima, Peru, from May 30-June 1, 2001), the feasibility of preparing a FOODlet for feeding infants and young children was explored. Within the spectrum of intervention tools for micronutrient supplementation, tablets are a pharmaceutical form, fortified spreads are a food, and sprinkles are an intermediate approach. The issues still to be discussed and resolved with regard to creating such a spread include its specific micronutrient formulation, the capacity of young children to consume the required amounts (from either the FOODlet alone or the FOODlet mixed with other foods), the iron content and overall antioxidant protection of the spread matrix and its vitamins, potential allergenicity of proteins, and the economic implications of using such a FOODlet in low-income societies.

Child↗
PubMed2003

Multiple micronutrient deficiencies: future research needs.

There has been a rising current of calls for a moratorium on international nutritional research in favor of an investment in intervention programs, per se. The topic of multiple-micronutrient supplementation reviewed at the International Workshop on Multi-Micronutrient Deficiency Control in the Life Cycle (May 30-June 1, 2001) has confirmed once again, however, the intimate interaction between program development and a supporting agenda of applied research. The areas of research required to produce successful intervention programs include biologic availability, safety and efficacy, communications and behavior, effectiveness, cost-effectiveness (efficiency), and food and pharmaceutical technology. Attention to safety and surveillance for unintended adverse effects has acquired new relevance as we analyze the multi-center International Research on Infant Supplementation (IRIS) I studies. All professionals involved in research projects in this area must assure both the quality and reliability of investigations and adhere to the highest principles of ethical conduct of research in human studies. The fundamental principles of research design and hypothesis development, quality assurance, reliability of measurements, and sound and unbiased interpretation of findings apply to all experimental science, and must be guaranteed for this mission. Agencies, academic institutions, and industry alike must work to create a system in which researchers can uphold these standards, and realize at the same time that the area of multi-micronutrient supplementation in developing countries can be a fertile area for training future researchers.

Cost-Benefit Analysis↗
PubMed2003

Diet and long-term health: an African Diaspora perspective.

The life-stage approach, which views the behaviours and exposures of an individual from the preconceptual situation of the parent through pregnancy, infancy, childhood and adolescence, and into the advancing years through adulthood, is the basis of analysis of strategies to improve long-term health. Among the behaviours of note is the dietary selection pattern, conditioning our exposure to nutrients and dietary constituents that influences growth, nutriture, cognitive and physical performance, and disease resistance and susceptibility. The African Diaspora created a population displaced from Africa to the Western Hemisphere as part of the African slave trade from the 16th to 18th centuries. It continues to manifest distinct dietary and lifestyle practices in the context of a health experience that is different both from the population in their African countries of origin and from the other ethnicities in their countries of displacement and current residence. Afro-Americans are more susceptible to a series of diseases and conditions including low birth weight, violence, and HIV/AIDS, as well as the non-communicable diseases: obesity, diabetes mellitus, cardiovascular disease, hypertension, stroke, renal failure, breast cancer, prostate cancer and lead poisoning. The differential nature of dietary practices are conditioned at times by the poverty and marginalisation of the populace, resulting in either disadvantageous or beneficial outcomes relative to others' eating habits. Serious consideration must be given to the possibility that ethnic difference give rise to different requirements and tolerances for essential nutrients and distinct protective or adverse responses to foods and dietary substances. The major challenges to health improvement for the African Diaspora is coming to grips with the policy and programmatic nuances of differential treatment and the effecting the behavioural changes that would be needed in a population skeptical of the motives of media and of the power elites of their societies.

Black or African American↗
PubMed2003

Alleviation of vitamin A deficiency with palm fruit and its products.

The decreased dietary diversity wrought from the adoption of the settled, agrarian system to replace the hunter-gather and pastoralist lifestyles assured a stable supply of protein and calories from grains and tubers while creating a vulnerability for humans to suffer micronutrient deficiencies. The vitamin A from animal tissue is more bioavailable to humans than the provitamin A in the matrix of green plants. Provitamin A carotenes achieve a dietary vitamin A efficacy nearly equivalent to that of the preformed vitamin only in the context of an oily matrix. The homeostatic regulation of carotene bioconversion by the intestine, moreover, prevents any excess toxic accumulation of vitamin A from provitamin A sources. The efficacy and safety of the palm fruit (genus Elaeis) as a source of vitamin A, in addition to its cultural recognition as a food, are more consistent with the gentler concept of "alleviation" of the public health problem of hypovitaminosis A, then the more aggressive, medical model of "eradication" with its greater potential for risk and collateral damage. The palm fruit and its derivatives achieve new opportunities for creative contribution and sustained use in formats of supplementation (prophylactic in children and women, for lactation), food-to-food fortification (in bakery goods and snacks, as condiments), and even in food diversification strategies. Experience in India, South Africa, and Guatemala begins to define and delineate the opportunities and limitations for the palm fruit to contribute to the alleviation of endemic vitamin A deficiency.

Biological Availability↗