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Biomedical subjects

K H Brown

Publications and source records attributed to K H Brown.

At least 19 recordsLinked to original sources
PubMed2006

Use of androgenesis for estimating maternal and mitochondrial genome effects on development and oxygen consumption in rainbow trout, Oncorhynchus mykiss.

Chromosome set manipulation was used to produce rainbow trout, Oncorhynchus mykiss, with identical nuclear backgrounds, but different maternal backgrounds to determine mitochondrial effects on development rate and oxygen consumption. Significant differences in development rate and oxygen consumption were observed between groups from different females. Development rates ranged from a mean of 317.97 degree days ( degrees d) to 335.25 degrees d in progeny from different females. Mean oxygen consumption rates ranged from 3.31 micromol O2 g(-1) wet mass h(-1) to 9.66 micromol O2 g(-1) wet mass h(-1). Oxygen consumption and development rate analysis revealed the two slowest developing groups had the highest oxygen consumption rates. Development rate differences between second generation clonal females indicate that mitochondrial genomes play a significant role on early development and are comparable to development rate differences between clonal lines of rainbow trout. These results indicate that selection for mitochondrial genomes could increase growth rates and possibly food conversion ratios in aquaculture species.

Animals↗
PubMed2005

The Food Marketing Institute and the National Council of Chain Restaurants: animal welfare and the retail food industry in the United States of America.

In order to achieve real change, there must be a motivating force and all the stakeholders need to be involved. This is the premise of the animal welfare programme developed for the food retail, wholesale and chain restaurant industries in the United States of America (USA) by the Food Marketing Institute (FMI) and the National Council of Chain Restaurants (NCCR). This paper outlines a collaborative process that retailers and producers in the USA are using to enhance the care and welfare of animals in commercial food production. Although the efforts of the FMI and the NCCR are still underway, the process provides one example of how different parts of the food production system can work together to achieve positive change.

Animal Welfare↗
PubMed2003

A consolidated linkage map for rainbow trout (Oncorhynchus mykiss).

Androgenetic doubled haploid progeny produced from a cross between the Oregon State University and Arlee clonal rainbow trout (Oncorhynchus mykiss) lines, used for a previous published rainbow trout map, were used to update the map with the addition of more amplified fragment length polymorphic (AFLP) markers, microsatellites, type I and allozyme markers. We have added more than 900 markers, bringing the total number to 1359 genetic markers and the sex phenotype including 799 EcoRI AFLPs, 174 PstI AFLPs, 226 microsatellites, 72 VNTR, 38 SINE markers, 29 known genes, 12 minisatellites, five RAPDs, and four allozymes. Thirty major linkage groups were identified. Synteny of linkage groups in our map with the outcrossed microsatellite map has been established for all except one linkage group in this doubled haploid cross. Putative homeologous relationships among linkage groups, resulting from the autotetraploid nature of the salmonid genome, have been revealed based on the placement of duplicated microsatellites and type I loci.

Animals↗
PubMed2001

Absorption of iron from unmodified maize and genetically altered, low-phytate maize fortified with ferrous sulfate or sodium iron EDTA.

BACKGROUND: Reducing the phytate content in grains by genetic manipulation is a novel approach to increasing nonheme-iron absorption from mixed diets. Fractional iron absorption from a genetically modified strain of low-phytate maize (LPM) increased significantly, by 50%. OBJECTIVE: We assessed iron absorption from porridges prepared from the same LPM (lpa-1-1 mutant) and unmodified wild-type maize (WTM), both of which were fortified with either ferrous sulfate or sodium iron EDTA. DESIGN: Porridges providing 3.4 mg Fe were fortified with either ferrous sulfate or sodium iron EDTA to provide an additional 1 mg Fe/serving. In 14 nonanemic women, iron absorption was measured as the amount of radioiron incorporated into red blood cells (extrinsic tag method) 12 d after consumption of the study diets. RESULTS: No significant effect of phytate content on iron absorption was found when porridge was fortified with either sodium iron EDTA or ferrous sulfate. Fractional absorption of iron from WTM porridge fortified with sodium iron EDTA (5.73%) was 3.39 times greater than that from the same porridge fortified with ferrous sulfate (1.69%). Fractional absorption of iron from the sodium iron EDTA-fortified LPM porridge (5.40%) was 2.82 times greater than that from LPM porridge fortified with ferrous sulfate (1.91%) (P<0.0001 for both comparisons, repeated-measures analysis of variance). Thus, the previously identified benefit of LPM was no longer detectable when maize porridge was fortified with additional iron. CONCLUSION: Iron was absorbed more efficiently when the fortificant was sodium iron EDTA rather than ferrous sulfate, regardless of the type of maize.

Adult↗
PubMed2001

Multiple micronutrient supplementation increases the growth of Mexican infants.

BACKGROUND: The role of single micronutrient deficiencies in the etiology of growth retardation has recently gained attention. However, because multiple micronutrient deficiencies are common in children in developing countries, it is possible that more than one micronutrient may limit growth and, hence, the correction of a single deficiency may not be enough to improve growth substantially. OBJECTIVE: The objective was to evaluate the effect of multiple micronutrient supplementation on the growth of children aged 8-14 mo whose diets were poor in several micronutrients. DESIGN: Children were randomly assigned to 1 of 2 groups. One group received a multiple micronutrient supplement containing the recommended dietary allowance (RDA) or 1.5 times the RDA of vitamins A, D, E, K, C, B-1, B-6, B-12, riboflavin, niacin, biotin, folic acid, and pantothenic acid, and iron, zinc, iodine, copper, manganese, and selenium. The other group received a placebo. Supplements were administered 6 d/wk for an average of 12.2 mo. Body length was measured at baseline and monthly thereafter until the end of supplementation. RESULTS: Supplemented infants initially aged <12 mo had significantly greater length gains than did the placebo group, with a difference of 8.2 mm (length-for-age z score: 0.3) at the end of supplementation. In contrast, differences in length gains between the supplemented and placebo groups initially aged > or =12 mo were not significant. CONCLUSIONS: Micronutrient deficiencies limited the growth of the Mexican infants studied. Improving micronutrient intakes should be a component of interventions to promote growth in infants living in settings where micronutrient intakes are inadequate.

Age Factors↗
PubMed2001

Effects of exclusive breastfeeding for four versus six months on maternal nutritional status and infant motor development: results of two randomized trials in Honduras.

To examine whether the duration of exclusive breastfeeding affects maternal nutrition or infant motor development, we examined data from two studies in Honduras: the first with 141 infants of low-income primiparous women and the second with 119 term, low birth weight infants. In both studies, infants were exclusively breastfed for 4 mo and then randomly assigned to continue exclusive breastfeeding (EBF) until 6 mo or to receive high-quality, hygienic solid foods (SF) in addition to breast milk between 4 and 6 mo. Maternal weight loss between 4 and 6 mo was significantly greater in the exclusive breastfeeding group (EBF) group than in the group(s) given solid foods (SF) in study 1 (-0.7 +/- 1.5 versus -0.1 +/- 1.7 kg, P < 0.05) but not in study 2. The estimated average additional nutritional burden of continuing to exclusively breastfeed until 6 mo was small, representing only 0.1-6.0% of the recommended dietary allowance for energy, vitamin A, calcium and iron. Women in the EBF group were more likely to be amenorrheic at 6 mo than women in the SF group, which conserves nutrients such as iron. In both studies, few women (10-11%) were thin (body mass index <19 kg/m(2)), so the additional weight loss in the EBF group in study 1 was unlikely to have been detrimental. Infants in the EBF group crawled sooner (both studies) and were more likely to be walking by 12 mo (study 1) than infants in the SF group. Taken together with our previous findings, these results indicate that the advantages of exclusive breastfeeding during this interval appear to outweigh any potential disadvantages in this setting.

Amenorrhea↗
PubMed2000

Predictors of growth from 1 to 18 months among breast-fed Ghanaian infants.

OBJECTIVE: To examine factors associated with the physical growth of breast-fed Ghanaian infants during the first 18 months of life. DESIGN: A community-based longitudinal study. SETTING: The study was carried out in Techiman, a district capital and major food trading center in the Brong Ahafo region of Ghana. SUBJECTS: One-month old infants (n=216) with birth weight >/= 2.5 kg were recruited from Maternal and Child Health Centers. METHOD: From 6 to 12 months, infants were provided with one of four types of nutritionally enhanced complementary foods. Anthropometric assessments were completed monthly from 1 to 12 months and every other month from 12 to 18 months. Information was collected on household characteristics, morbidity from common infections and dietary intakes. Blood samples were collected at 6 and 12 months to assess iron, zinc, riboflavin and vitamin A status. Multiple regression analysis was used to examine factors associated with growth during the age intervals of 1-6, 4-6, 6-12 and 12-18 months as well as size attained at 12 and 18 months. RESULTS: Prevalence of diarrhea and fever were negatively associated with growth during the first year of life. No significant relationship was found between respiratory illness (defined as cough or purulent nasal discharge) and growth. With the exception of dietary zinc intake, dietary variables were generally not significantly associated with growth. Maternal education was positively associated with growth during most of the age intervals. CONCLUSION: These findings suggest that interventions to reduce morbidity and improve the education of girls may benefit children's growth in this population. SPONSORSHIP: Nestle Foundation; Rockefeller Foundation African Dissertation Internship Award; Fulbright Scholarship. European Journal of Clinical Nutrition (2000) 54, 41-49

Anthropometry↗
PubMed2000

Exclusively breastfed, low birthweight term infants do not need supplemental water.

UNLABELLED: Breast milk intake, urine volume and urine-specific gravity (USG) of exclusively breastfed, low birthweight (LBW) term male infants in Honduras were measured during 8-h periods at 2 (n = 59) and 8 (n = 68) wk of age. Ambient temperature was 22-36 degrees C and relative humidity was 37-86%. Maximum USG ranged from 1.001 to 1.012, all within normal limits. CONCLUSIONS: We conclude that supplemental water is not required for exclusively breastfed, LBW term infants, even in hot conditions.

Breast Feeding↗
PubMed2000

Therapeutic effects of oral zinc in acute and persistent diarrhea in children in developing countries: pooled analysis of randomized controlled trials.

BACKGROUND: Zinc deficiency is prevalent in children in developing countries. Supplemental zinc provides therapeutic benefits in diarrhea. OBJECTIVE: We sought to measure the effect of supplemental zinc given with oral rehydration therapy during recovery from acute or persistent diarrhea. DESIGN: We conducted pooled analyses including all available published and unpublished randomized controlled trials of the effects of supplementary oral zinc in children aged <5 y with acute or persistent diarrhea. We used Cox survival regression analysis to evaluate the overall effect of zinc on continuation of diarrhea and possible differential effects in subgroups divided by sex, age, weight-for-height, and initial plasma zinc concentration. Dichotomous outcomes were analyzed by logistic regression. To assess the effects of excluding studies without original data from the pooled analyses, effect-size was estimated for all studies by using random-effects models. RESULTS: Zinc-supplemented children had a 15% lower probability of continuing diarrhea on a given day (95% CI: 5%, 24%) in the acute-diarrhea trials and a 24% lower probability of continuing diarrhea (95% CI: 9%, 37%) and a 42% lower rate of treatment failure or death (95% CI: 10%, 63%) in the persistent-diarrhea trials. In none of the subgroup analyses were the 2 subgroups of each pair significantly different from each other; however, in persistent diarrhea there tended to be a greater effect in subjects aged <12 mo, who were male, or who had wasting or lower baseline plasma zinc concentrations. CONCLUSION: Zinc supplementation reduces the duration and severity of acute and persistent diarrhea.

Acute Disease↗
PubMed2000

Predictors of micronutrient status among six- to twelve-month-old breast-fed Ghanaian infants.

This study describes the factors associated with hemoglobin and plasma ferritin, zinc and retinol concentrations and erythrocyte riboflavin status among 208 Ghanaian infants who participated in a complementary feeding intervention trial from 6 to 12 mo of age. Anthropometric, morbidity and dietary data were collected regularly from 1 to 12 mo; blood samples were collected at 6 and 12 mo. The prevalence of low micronutrient status at 6 and 12 mo, respectively, was as follows: hemoglobin <100 g/L, 30 and 34%; plasma ferritin <12 microg/L, 17 and 43%; plasma zinc <10.7 micromol/L, 4 and 6%; plasma retinol <0.7 micromol/L, 26 and 26%; erythrocyte riboflavin <200 umol/L of packed red cells, 14 and 10%. Multiple regression was used to identify factors significantly associated with micronutrient status. From 6 to 12 mo, fever prevalence was associated with a decrease in hemoglobin, but an increase in erythrocyte riboflavin concentrations, and diarrhea prevalence was related to a decrease in plasma retinol. Seasonal differences were evident for most of the indicators of micronutrient status, and elevated C-reactive protein levels (indicative of recent infection) were related to lower hemoglobin, retinol and zinc concentrations but higher ferritin and erythrocyte riboflavin concentrations. Weight at birth or at 1 mo of age was positively related to iron, zinc and vitamin A status, but a more rapid weight gain was associated with depletion of iron stores. Socioeconomic status was related to higher hemoglobin, riboflavin and zinc concentrations. The feeding of a micronutrient-fortified food was positively associated with plasma ferritin and retinol concentrations at 12 mo. These results suggest that prenatal factors, socioeconomic status, dietary intake and morbidity all influence infant micronutrient status, and that fortification of complementary foods is one potential avenue for preventing deficiencies.

Anthropometry↗
PubMed2000

Public health implications or urban agriculture.

The article presents the case for stronger public policies in support of urban gardening as a means to improve public health. It considers several beneficial aspects of gardening, such as food security, economic development, exercise, psychological and community well-being, and environmental stewardship. It also considers some of the public health problems associated with urban agriculture and suggests policies to ameliorate them. In the balance, urban gardening has potential as an important element of urban public health.

Agriculture↗
PubMed1999

Randomized, community-based trial of the effect of zinc supplementation, with and without other micronutrients, on the duration of persistent childhood diarrhea in Lima, Peru.

OBJECTIVE: To determine whether supplemental zinc, with or without additional micronutrients, affects the severity and duration of persistent childhood diarrhea and the rate of nutritional recovery. DESIGN: The study was a community-based, double-blind, randomized trial implemented in a shanty town in Lima, Peru. Children aged 6 to 36 months with persistent (>/=14 days) diarrhea received daily, for 2 weeks, a placebo (group P, n = 136) or a supplement of 20 mg of zinc, either with (group Z+VM, n = 137) or without (group Z, n = 139) additional vitamins and minerals. Symptoms of illness were recorded daily, and biochemical and anthropometric assessments were completed at baseline and on day 15. RESULTS: The treatment groups were similar at baseline with regard to the characteristics of the presenting episode, anthropometric data, and plasma zinc concentration. The children consumed, on average, 95% (group P), 94% (group Z), or 88% (group Z+VM) of the supplement (P <.001). The plasma zinc concentration did not change significantly from baseline to day 15 in group P (4 microg/dL) but increased by 38 microg/dL in group Z and 14 microg/dL in group Z+VM. The median duration of diarrhea after starting treatment was 1 day; among children who continued to have diarrhea, there was a significant effect of treatment on diarrheal duration (P =.04, analysis of covariance). Specifically, the duration of illness was significantly reduced by 28% in children in group Z (P =.01) and by 33% in girls in group Z+VM (P =.04). There were no differences in the severity of the episode by treatment group. CONCLUSION: There was a significant reduction in the duration of persistent diarrhea in selected subgroups of zinc-supplemented ambulatory patients in this population.

Analysis of Variance↗
PubMed1999

Prevention of diarrhea and pneumonia by zinc supplementation in children in developing countries: pooled analysis of randomized controlled trials. Zinc Investigators' Collaborative Group.

OBJECTIVES: This study assessed the effects of zinc supplementation in the prevention of diarrhea and pneumonia with the use of a pooled analysis of randomized controlled trials in children in developing countries. STUDY DESIGN: Trials included were those that provided oral supplements containing at least one half of the United States Recommended Daily Allowance (RDA) of zinc in children <5 years old and evaluated the prevention of serious infectious morbidity through household visits. Analysis included 7 "continuous" trials providing 1 to 2 RDA of elemental zinc 5 to 7 times per week throughout the period of morbidity surveillance and 3 "short-course" trials providing 2 to 4 RDA daily for 2 weeks followed by 2 to 3 months of morbidity surveillance. The effects on diarrhea and pneumonia were analyzed overall and in subgroups defined by age, baseline plasma zinc concentration, nutritional status, and sex. The analysis used random effects hierarchical models to calculate odds ratios (OR) and 95% CIs. RESULTS: For the zinc-supplemented children compared with the control group in the continuous trials, the pooled ORs for diarrheal incidence and prevalence were 0.82 (95% CI 0.72 to 0.93) and 0.75 (95% CI 0.63 to 0.88), respectively. Zinc-supplemented children had an OR of 0.59 (95% CI 0.41 to 0.83) for pneumonia. No significant differences were seen in the effects of the zinc supplement between the subgroups examined for either diarrhea or pneumonia. In the short-course trials the OR for the effects of zinc on diarrheal incidence (OR 0.89, 95% CI 0.62 to 1.28) and prevalence (OR 0.66, 95% CI 0.52 to 0.83) and pneumonia incidence (OR 0.74, 95% CI 0.40 to 1.37) were similar to those in the continuous trials. CONCLUSIONS: Zinc supplementation in children in developing countries is associated with substantial reductions in the rates of diarrhea and pneumonia, the 2 leading causes of death in these settings.

Child↗
PubMed1999

Maternal vitamin A nutriture and the vitamin A content of human milk.

Because of the many functions of vitamin A in human physiology, deficiency or excess of the vitamin in lactating women or their infants can adversely affect their health. Infants are born with low body stores of vitamin A, and rely on vitamin A in milk to meet their needs. The vitamin A content of milk is related to maternal vitamin A status and maternal dietary vitamin A intake during lactation. Low-income lactating women in non-industrialized countries have lower milk vitamin A concentrations than lactating women in industrialized countries. Supplementation of lactating women in non-industrialized countries with vitamin A or beta-carotene has resulted in increased milk vitamin A concentrations. However, the optimal timing and dose for sustaining adequate levels of vitamin A in milk throughout the lactation period has not been determined. Further research is needed to understand factors affecting the transfer of vitamin A to milk, and to evaluate various strategies for improving the vitamin A status of mothers and infants.

Breast Feeding↗
PubMed1999

The effects of fermentation and/or vacuum flask storage on the presence of coliforms in complementary foods prepared for Ghanaian children.

Microbial contamination of complementary foods is a major cause of childhood diarrhoea. In a community-based study in Ghana, we evaluated whether fermentation of maize porridge or storage of porridge in vacuum flasks reduces coliform contamination. The complementary food examined, Weanimix, consisted of, on a dry weight basis, toasted maize (75%), peanuts (10%), and soybeans (15%) milled into flour. The fermented food was Weanimix made with drum-dried, previously fermented maize. Fifty women with infants 6-18 months of age participated. A repeated measures cross-over design was used. Each mother participated in all four treatments (1 week per treatment, in random order): (a) non-fermented Weanimix (W), (b) fermented Weanimix (F), (c) non-fermented Weanimix stored in a vacuum flask (WV), and (d) fermented Weanimix stored in a vacuum flask (FV). Each week, mothers were supplied with the appropriate food, and asked to prepare a porridge each morning by boiling the dry mix in water. Samples were collected in the evenings and immediately plated onto 3 M Petrifilm. Contamination was defined as > or = 100 colony-forming units of coliforms per ml. Contamination rates (95% confidence intervals) were W = 48% (38-58%), F = 25% (17-34%), WV = 42% (32-52%), and FV = 13% (6-20%). All pairwise comparisons were significant (P < 0.05) except for W vs WV. Within the WV treatment, contamination rates were 85% when the sample temperature fell below 50 degrees C (N = 41) vs 12% when it remained > 50 degrees C (N = 59) (P < 0.001). These results indicate that contamination is reduced by fermentation, and further reduced by vacuum flask storage of fermented foods. For non-fermented foods, vacuum flask-storage was protective only when the temperature was maintained at > 50 degrees C; at < or = 50 degrees C vacuum flask storage increased the risk of contamination.

Cross-Over Studies↗
PubMed1999

Effects of dietary viscosity and energy density on total daily energy consumption by young Peruvian children.

BACKGROUND: Results of prior studies of the effect of viscosity reduction of high-energy-density, starch-containing diets on young children's energy intakes are inconsistent, possibly because of differences in the characteristics of the unmodified diets with which the low-viscosity diets were compared. OBJECTIVE: Our objective was to determine the effects of dietary viscosity and energy density on total daily energy consumption by young, non-breast-fed children. DESIGN: We measured the amount of food consumed and the duration of meals during 3 substudies, in each of which 3 study diets were offered for 4 consecutive days each in random sequence: high energy density, high viscosity (HD-HV); high energy density, low viscosity (HD-LV); and low energy density, low viscosity (LD-LV). The viscosity and energy density of the unmodified starch-containing HD-HV diet were varied across substudies to determine whether the effect of amylase liquefaction was related to the initial characteristics of the HD-HV diet. The viscosity of the HV diets ranged from 79000 to 568000 mPa s; energy density of the HD diets ranged from approximately 4.18 to 4.93 kJ (1.00-1.18 kcal)/g. Viscosity of the LV diets was approximately 3000 mPa s and the energy density of the LD diets was approximately 2.47 kJ (0.6 kcal)/g. RESULTS: In each substudy, children consumed more of the LD-LV diet (g kg body wt(-)(1) d(-)(1)) than of the other diets and more of the HD-LV diet than of the HD-HV diet (P < 0.001). Energy consumption from the HD-LV diet was greater than from the other diets (P < 0.001), but the energy intakes from the latter diets were not significantly different. CONCLUSION: Amylase liquefaction of HD-HV porridges resulted in increased energy consumption by young children.

Anthropometry↗