(1/4438) Maternal vitamin A or beta-carotene supplementation in lactating bangladeshi women benefits mothers and infants but does not prevent subclinical deficiency.
The effects of maternal postpartum vitamin A or beta-carotene supplementation on maternal and infant serum retinol concentrations, modified relative dose-response (MRDR) ratios and breast milk vitamin A concentrations were assessed during a community-based trial in Matlab, Bangladesh. At 1-3 wk postpartum, women were randomly assigned to receive either (1) a single dose of 200,000 international units [60,000 retinol equivalents (RE)] vitamin A followed by daily placebos (n = 74), (2) daily doses of beta-carotene [7.8 mg (1300 RE)] (n = 73) or (3) daily placebos (n = 73) until 9 mo postpartum. Compared to placebos, vitamin A supplementation resulted in lower maternal MRDR ratios (i.e., increased liver stores) and higher milk vitamin A concentrations at 3 mo, but these improvements were not sustained. The beta-carotene supplementation acted more slowly, resulting in milk vitamin A concentrations higher than the placebo group only at 9 mo. Irrespective of treatment group, over 50% of women produced milk with low vitamin A concentrations (=1.05 micromol/L or =0.28 micromol/g fat) throughout the study. Overall, mean maternal serum retinol concentrations were not affected by supplementation. Compared to the placebo group, the mean MRDR ratio of 6-mo-old infants was higher in the vitamin A group. Infants (33%) had serum retinol concentrations <0.70 micromol/L and 88% had MRDR ratios >/=0. 06. We conclude that while both interventions were beneficial, neither was sufficient to correct the underlying subclinical vitamin A deficiency in these women nor to bring their infants into adequate vitamin A status. (+info)
(2/4438) A prospective randomized study of megestrol acetate and ibuprofen in gastrointestinal cancer patients with weight loss.
The use of megestrol acetate in the treatment of weight loss in gastrointestinal cancer patients has been disappointing. The aim of the present study was to compare the combination of megestrol acetate and placebo with megestrol acetate and ibuprofen in the treatment of weight loss in such patients. At baseline, 4-6 weeks and 12 weeks, patients underwent measurements of anthropometry, concentrations of albumin and C-reactive protein and assessment of appetite, performance status and quality of life using EuroQol-EQ-5D and EORTC QLQ-C30. Thirty-eight and 35 patients (median weight loss 18%) were randomized to megestrol acetate/placebo or megestrol acetate/ibuprofen, respectively, for 12 weeks. Forty-six (63%) of patients failed to complete the 12-week assessment. Of those evaluable at 12 weeks, there was a decrease in weight (median 2.8 kg) in the megestrol acetate/placebo group compared with an increase (median 2.3 kg) in the megestrol acetate/ibuprofen group (P<0.001). There was also an improvement in the EuroQol-EQ-5D quality of life scores of the latter group (P<0.05). The combination of megestrol acetate/ibuprofen appeared to reverse weight loss and appeared to improve quality of life in patients with advanced gastrointestinal cancer. Further trials of this novel regimen in weight-losing patients with hormone-insensitive cancers are warranted. (+info)
(3/4438) Leptin and reproduction.
In the few years since leptin was identified as a satiety factor in rodents, it has been implicated in the regulation of various physiological processes. Leptin has been shown to promote sexual maturation in rodent species and a role in reproduction has been investigated at various sites within the hypothalamo-pituitary-gonadal axis. This review considers the evidence that leptin (or alteration in amount of body fat) can affect reproduction. There is evidence that leptin plays a permissive role in the onset of puberty, probably through action on the hypothalamus, where leptin receptors are found in cells that express appetite-regulating peptides. There is little evidence that leptin has a positive effect on the pituitary gonadotrophs and the gonads. There is also very little indication that leptin acts in an acute manner to regulate reproduction in the short term. It seems more likely that leptin is a 'barometer' of body condition that sends signals to the brain. Studies in vitro have shown negative effects on ovarian steroid production and there are no reports of effects on testicular function. Leptin concentrations in plasma increase in women during pregnancy, owing to production by the placenta but the functional significance of this is unknown. A number of factors that affect the production and action of leptin have yet to be studied in detail. (+info)
(4/4438) Effects of pre- or postpartum selenium supplementation on selenium status in beef cows and their calves.
The effect of Se supplementation before or after calving on Se status in deficient cows and their calves was studied using 72 beef cows in two experiments. In Exp. 1, cows calving in February or March 1997 were supplemented orally for 15 d in late pregnancy with 13.0, 32.5, or 45.5 mg of Se/d as sodium selenite. Glutathione peroxidase (GSH-Px) activities were measured in red blood cells (RBC) or plasma of cows and calves at d 15 and between d 17 and 88 after calving. In Exp. 2, cows calving in January 1997 were supplemented orally with .0, 13.0, or 32.5 mg of Se/d for 15 d postpartum, and calves were injected with 1.38 mg of Se when 2 d old and at an average age of 49 d. The GSH-Px activities were measured in 30-d-old calves and in cows and calves between d 77 and 115 after calving. In both experiments, Se supplementation resulted in adequate Se status for the dams. The increase in RBC GSH-Px activity was faster with 45.5 mg of Se/d, and GSH-Px activities remained high for up to 98 d after the end of supplementation. The improvement in Se status in calves as a result of maternal supplementation was greater in Exp. 1 than in Exp. 2, suggesting that the placental transfer of Se is more efficient than milk transfer. Prepartum oral Se supplementation of deficient beef cows with 13.0 mg of Se/d for 15 d allowed adequate Se status of dams and calves, and 45.5 mg of Se/d resulted in a faster improvement of Se status. Parenteral administration of 1.38 mg of Se to newborn calves did not sustain normal Se status in calves issued from deficient cows. (+info)
(5/4438) Copper status of ewes fed increasing amounts of copper from copper sulfate or copper proteinate.
The Cu status of mature, crossbred ewes fed two sources (CuSO4 vs. Cu proteinate) and three levels (10, 20, or 30 mg/kg) of dietary Cu was determined in a 73-d feeding trial. Ewes (n = 30) were fed a basal diet containing rice meal feed, cottonseed hulls, cottonseed meal, meat and bone meal, cracked corn, and vitamin-mineral supplements at 2.5% of BW to meet NRC requirements for protein, energy, macrominerals, and microminerals, excluding Cu. The basal diet contained 5 mg/kg Cu, 113 mg/kg Fe, .1 mg/kg Mo, and .17% S. Copper sulfate or Cu proteinate was added to the basal diet to supply 10, 20, or 30 mg/kg of dietary copper in a 2x3 factorial arrangement of treatments. Ewes were housed in 3.7- x 9.1-m pens in an open-sided barn. Blood samples were collected on d 28 and 73. Ewes were slaughtered on d 74, and liver and other tissues were collected to determine Cu concentrations. An interaction (P = .08) occurred between source and level for liver Cu. The interaction existed due to an increase in liver Cu concentrations when ewes were fed increasing dietary Cu from CuSO4 but not when fed Cu proteinate diets. There was no source x level interaction (P>.10) for the blood constituents measured. On d 73, plasma ceruloplasmin activity was greater (P<.05) in ewes fed Cu proteinate than in those fed CuSO4 (33.1 vs. 26.8 microM x min(-1) x L(-1)). Increasing the concentration of dietary Cu did not affect (P>.10) plasma ceruloplasmin. Packed cell volume (PCV), red blood cell count (RBC), white blood cell count, whole blood hemoglobin (wHb), plasma hemoglobin, and plasma Cu were similar between sources of Cu. Ewes fed 20 mg/kg Cu had lower (P<.05) PCV, RBC, and wHb than those fed 10 or 30 mg/kg Cu diets. Feeding up to 30 mg/kg Cu from these sources did not cause an observable Cu toxicity during the 73-d period. (+info)
(6/4438) Biotin status: which are valid indicators and how do we know?
Although estimated average requirements for biotin have been proposed, the human requirements for biotin in specific populations and at various ages remain uncertain, in part because indicators of biotin status have not been validated. With the use of improved methods for measuring biotin and metabolites, a recent study indicated that decreased urinary excretion of biotin and bisnorbiotin is an early and sensitive indicator of biotin deficiency, but decreased serum concentration of biotin is not. Increased urinary excretion of 3-hydroxyisovaleric acid (3-HIA), a leucine metabolite that is excreted in increased quantities with deficiency of the biotin-dependent enzyme beta-methylcrotonyl-CoA carboxylase, is also an early and sensitive indicator of biotin deficiency. When these indicators were assessed longitudinally in 13 pregnant women, biotin excretion was not significantly decreased early in pregnancy but did decrease significantly from early to late pregnancy. Excretion of 3-HIA was abnormally increased in about three-fourths of the women studied in both early and late pregnancy. Thus, each indicator detected biotin deficiency late in pregnancy, but assessment of biotin status for the two indicators conflicted early in pregnancy. Preliminary results from a trial assessing response of 3-HIA excretion to biotin treatment indicate that biotin status is indeed impaired both early and late in pregnancy. (+info)
(7/4438) Nutrition and health outcomes associated with food insecurity and hunger.
This paper explores how food insecurity and hunger relate to health and nutrition outcomes in food-rich countries such as the United States. It focuses on two subgroups of the population for whom data are available: women of childbearing age and school-age children. Special consideration is given to examining how food insecurity relates to these outcomes independently of socioeconomic status and poverty. In a population-based sample of women of childbearing age, the least severe level of food insecurity (household food insecurity) was correlated with higher body mass index (BMI), controlling for other available and known influences on obesity including income level. In low income school-age children from two large urban areas of the U.S., risk of hunger and hunger were associated with compromised psychosocial functioning, controlling for maternal education and estimated household income. The nutrition and health consequences of food insecurity comprise a potentially rich area for future, socially relevant research in the field of nutritional sciences. (+info)
(8/4438) Food insecurity: consequences for the household and broader social implications.
A conceptual framework showing the household and social implications of food insecurity was elicited from a qualitative and quantitative study of 98 households from a heterogeneous low income population of Quebec city and rural surroundings; the study was designed to increase understanding of the experience of food insecurity in order to contribute to its prevention. According to the respondents' description, the experience of food insecurity is characterized by two categories of manifestations, i.e., the core characteristics of the phenomenon and a related set of actions and reactions by the household. This second category of manifestations is considered here as a first level of consequences of food insecurity. These consequences at the household level often interact with the larger environment to which the household belongs. On a chronic basis, the resulting interactions have certain implications that are tentatively labeled "social implications" in this paper. Their examination suggests that important aspects of human development depend on food security. It also raises questions concerning the nature of socially acceptable practices of food acquisition and food management, and how such acceptability can be assessed. Guidelines to that effect are proposed. Findings underline the relevance and urgency of working toward the realization of the right to food. (+info)