Lack of hemoglobin response to iron supplementation in anemic mexican preschoolers with multiple micronutrient deficiencies

BACKGROUND

In developing countries, incomplete resolution of anemia with iron supplementation is often attributed to poor compliance or inadequate duration of supplementation, but it could result from deficiencies of other micronutrients.

OBJECTIVE

Our objective was to assess children's hematologic response to supervised, long-term iron supplementation and the relation of this response to other micronutrient deficiencies, anthropometry, morbidity, and usual dietary intake.

DESIGN

Rural Mexican children aged 18-36 mo (n = 219) were supplemented for 12 mo with either 20 mg Fe, 20 mg Zn, both iron and zinc, or placebo. Children were categorized as iron-unsupplemented (IUS; n = 109) or iron supplemented (IS; n = 108). Hemoglobin, hematocrit, mean corpuscular volume, mean cell hemoglobin, plasma concentrations of micronutrients that can affect hematopoiesis, anthropometry, and diet were assessed at 0, 6, and 12 mo; morbidity was assessed biweekly.

RESULTS

At baseline, 70% of children had low hemoglobin (</=115 g/L), 60% had low hematocrit, 48% were ferritin deficient, 10% had deficient and 33% had low plasma vitamin B-12 concentrations, 29% had deficient vitamin A concentrations, and 70% had deficient vitamin E concentrations. Iron supplementation increased ferritin from 11 +/- 14 microg/L at baseline to 31 +/- 18 microg/L after 6 mo (P < 0.001) and 41 +/- 17 microg/L after 12 mo. However, anemia persisted in 30% and 31% of supplemented children at 6 and 12 mo, respectively, and was not significantly different between the IUS and IS groups at 12 mo. Initial plasma vitamin B-12, height-for-age, and dietary quality predicted the hematopoietic response to iron.

CONCLUSION

Lack of hemoglobin response to iron was associated with indicators of chronic undernutrition and multiple micronutrient deficiencies.

In vitro and in vivo macrophage function can occur independently of SLP-76

Expression of SH2 domain-containing leukocyte-specific phosphoprotein of 76 kDa (SLP-76), a hematopoietic cell-specific adapter protein, is required to couple Syk family tyrosine kinase activation to downstream mediators such as phospholipase C (PLC)-gamma following TCR, platelet collagen receptor and mast cell Fc epsilon R stimulation. In addition to T cells, mast cells and platelets, SLP-76 is expressed in monocytes and macrophages. To determine the role of SLP-76 in Fc gamma R-stimulated signaling pathways in macrophages, we examined cultured bone marrow-derived macrophages (BMM) from SLP-76(-/-) and wild-type mice. In this study, we show that Fc gamma R cross-linking rapidly induces tyrosine phosphorylation of SLP-76 in wild-type BMM. Surprisingly, however, BMM from SLP-76(-/-) mice activate ERK2 and phosphorylate PLC-gamma 2 following Fc gamma R ligation. Furthermore, SLP-76(-/-) BMM display normal Fc gamma R-dependent phagocytic function and reactive oxygen intermediate production. SLP-76(-/-) and SLP-76(+/+) BMM secrete comparable levels of IL-12 in response to lipopolysaccharide and IFN-gamma. To examine macrophage function in vivo, SLP-76(-/-) mice were challenged i.v. with Listeria monocytogenes. SLP-76(-/-) mice survive and efficiently contain the acute phase of infection similar to wild-type mice but exhibit a stable chronic infection attributed to the lack of mature T cells. These data show that, although SLP-76 is required to couple Syk family PTK activity to downstream mediators and effector functions in Fc gamma R-induced pathways in some cell types, activation of Fc gamma R-dependent pathways occurs independently of SLP-76 in BM

Iron absorption from ferrous bisglycinate and ferric trisglycinate in whole maize is regulated by iron status

BACKGROUND

There is a need to determine whether iron absorption from iron amino acid chelates is protected from inhibition by dietary phytate and regulated normally by iron status.

OBJECTIVE

The objective of this study was to compare iron absorption from ferrous sulfate, ferrous bisglycinate, and ferric trisglycinate in whole-maize meal; to determine whether iron from ferrous bisglycinate and ferrous sulfate exchanges in the intestinal pool; and to assess iron absorption from ferrous bisglycinate and ferric trisglycinate over a range of iron statuses.

DESIGN

In study 1A, 10 iron-sufficient men consumed ferrous sulfate-fortified whole-maize meal porridge equilibrated with (59)Fe-sulfate on day 1 and (55)Fe-bisglycinate on day 2. In study 1B, these volunteers consumed ferrous sulfate-fortified porridge equilibrated with (59)Fe-sulfate and (55)Fe-bisglycinate simultaneously. In studies 2A and 2B, iron absorption from 3 mg Fe as (59)Fe-ascorbate, (55)Fe-bisglycinate, or (59)Fe-trisglycinate in water and in porridge was compared in 23 subjects with a range of iron statuses. Iron absorption was determined from blood radioactivity on day 16.

RESULTS

In study 1A, geometric mean iron absorption from ferrous bisglycinate was 6.0% (range: 2.6-13.6%), 4 times higher than that from ferrous sulfate (1. 7%; range: 1.0-3.3%; P < 0.05). In study 1B, absorption from neither source was different from that in study 1A. In studies 2A and 2B, absorption from all sources was strongly inversely related to serum ferritin, with geometric means of 32.5% (iron ascorbate), 9.1% (bisglycinate), and 15.3% (trisglycinate). Iron from ferric trisglycinate was poorly absorbed (2.3%; range: 0.5-9.2%) from maize.

CONCLUSION

In whole-maize meal, iron from ferrous bisglycinate is better absorbed than is iron from ferrous sulfate and does not exchange with iron from maize or ferrous sulfate in the intestinal pool. Absorption of iron from bisglycinate and trisglycinate is regulated normally by iron status.

Anemia and iron deficiency: effects on pregnancy outcome

This article reviews current knowledge of the effects of maternal anemia and iron deficiency on pregnancy outcome. A considerable amount of information remains to be learned about the benefits of maternal iron supplementation on the health and iron status of the mother and her child during pregnancy and postpartum. Current knowledge indicates that iron deficiency anemia in pregnancy is a risk factor for preterm delivery and subsequent low birth weight, and possibly for inferior neonatal health. Data are inadequate to determine the extent to which maternal anemia might contribute to maternal mortality. Even for women who enter pregnancy with reasonable iron stores, iron supplements improve iron status during pregnancy and for a considerable length of time postpartum, thus providing some protection against iron deficiency in the subsequent pregnancy. Mounting evidence indicates that maternal iron deficiency in pregnancy reduces fetal iron stores, perhaps well into the first year of life. This deserves further exploration because of the tendency of infants to develop iron deficiency anemia and because of the documented adverse consequences of this condition on infant development. The weight of evidence supports the advisability of routine iron supplementation during pregnancy.

Iron and zinc supplementation improves indicators of vitamin A status of Mexican preschoolers

BACKGROUND

The coexistence of multiple micronutrient deficiencies is a widespread public health problem in many regions of the world. Interactions between zinc deficiency and vitamin A metabolism have been reported but no longitudinal studies have evaluated the effect of iron deficiency on vitamin A.

OBJECTIVE

The objective of this study was to investigate the effect of supplementation with iron, zinc, or both on vitamin A and its metabolically related proteins retinol binding protein (RBP) and transthyretin.

DESIGN

The study was a longitudinal, double-blind, placebo-controlled trial in which 219 rural Mexican children aged 18-36 mo were randomly assigned to receive 20 mg Zn/d, 20 mg Fe/d, 20 mg Zn/d plus 20 mg Fe/d, or placebo.

RESULTS

Six months after supplementation, plasma retinol increased in all supplemented groups. Compared with placebo, zinc supplementation was associated with significantly higher plasma retinol and transthyretin but the increase in RBP was not significant. Iron supplementation significantly increased plasma retinol, RBP, and transthyretin. Supplementation with zinc plus iron significantly increased plasma retinol but not RBP or transthyretin. Children deficient in zinc, iron, or vitamin A (as indicated by nutrient plasma concentration) at the beginning of the study had a significantly greater increase in retinol than did children with adequate nutrient status.

CONCLUSIONS

Supplementation with zinc, iron, or both improved indicators of vitamin A status. The results of this study agree with previous observations of a metabolic interaction between zinc and vitamin A and suggest an interaction between iron and vitamin A metabolism.

Intervention within days for some orbital floor fractures: the white-eyed blowout

Management of blowout fractures involving the orbital floor has been controversial over the past several decades. One school of thought recommends conservative treatment for 4 to 6 months while another recommends a 'wait and watch' period of 2 weeks before intervention. The authors have encountered a group of patients with such fractures, commonly children (less than 16 years of age), who have sustained a blow to the periocular area, yet have marked motility restrictions in up and down gaze, minimal soft tissue signs of trauma, lack of enophthalmos, and very minimal evidence of floor disruption on radiologic exam. A 2-week waiting period has been found to be of little benefit in these persons and possibly harmful to their motility. We advocate surgery within the first few days after injury as it may help to avoid permanent motility restriction. The authors have termed this entity 'the white-eyed blowout fracture.'

Zinc and micronutrient supplements for children

Provision of zinc supplements to children should be considered when their usual diet is low in absorbable zinc; severe stunting, low plasma zinc, or both; or persistent diarrhea. Inadequate zinc intakes are highly prevalent in developing countries, especially during the period of complementary feeding when zinc requirements are high and breast milk contributes little. To date, systematic evaluation of the acceptability of different zinc salts used as supplements is lacking. Some zinc salts are unpalatable and cause problems, such as nausea, at higher doses. Zinc carbonate and oxide are insoluble and poorly absorbed. Little information on the bioavailability of different zinc supplements in the presence of dietary inhibitors of zinc absorption exists. More information is needed on the quantity and frequency of dosing. Consideration should be given to the routine inclusion of zinc in iron supplements provided to children and to the simultaneous inclusion of other micronutrients in zinc supplements.

Spot ferritin assay for serum samples dried on filter paper

A spot method was developed for analyzing ferritin from 20-microL serum samples (n = 71) that were spotted and dried on filter paper and stored frozen (2 d). Spot samples were thawed, incubated in a buffer containing cellulase, and centrifuged and the supernate assayed for ferritin by a commercial radioimmunoassay. The geometric means (+/- 1 SD) for ferritin analyzed with the spot and traditional methods were 49.4 (range: 14.9-164.0) and 47.5 (range: 14.4-156.0) micrograms/L, respectively. The two methods correlated strongly (r = 0.98, P = 0.0001). Storage of spot samples (n = 31) under various conditions (at room temperature, refrigerated, or frozen for 2 wk, or at room temperature for 4 wk) in airtight bags before analysis yielded ferritin values that were not significantly different from those obtained by the traditional method. Ferritin values from spotted samples stored at room temperature for 4 wk before being analyzed were only 2.2 micrograms/L higher than those from samples analyzed by the traditional method. With iron depletion defined as a serum ferritin concentration < 15 micrograms/L, this method corresponded absolutely with the traditional method in classifying individuals as iron sufficient or deficient. Thus, the spot ferritin method (with samples stored at room temperature for 4 wk) offers a reliable, accurate, and practical tool for iron status assessment in field studies. Capillary blood can be sampled to avoid the costs and concerns associated with venipuncture and spotted serum samples can be stored at room temperature for > or = 4 wk, eliminating the need for freezing during storage and transportation.

Vitamin B-12 deficiency is very prevalent in lactating Guatemalan women and their infants at three months postpartum

Vitamin B-12 status was evaluated in 113 Guatemalan women and their infants at 3 mo of lactation. Plasma vitamin B-12 was deficient or low in 46.7% of the mothers, and holotranscobalamin II (holo TC II) concentrations were low in 32.3%, which may indicate vitamin B-12 malabsorption. Only 9% had deficient or low plasma folate. Breast milk vitamin B-12 was low in 31%, and negatively correlated with infant urinary methylmalonic acid (UMMA, r = -0.22, P < 0.05, n = 88); UMMA was elevated in 12.2% of the infants, indicating vitamin B-12 deficiency. Mothers of the infants with elevated UMMA had significantly lower concentrations of vitamin B-12 in their breast milk compared with mothers of infants with normal UMMA concentrations (410.7 +/- 247.7 vs. 705.3 +/- 487.5 pmol/L, P = 0.05, n = 87). Mean maternal dietary intake of vitamin B-12 was significantly correlated with plasma vitamin B-12 (r = 0.20, P = 0. 05, n = 94) and was the main determinant of plasma vitamin B-12 in a linear regression model. Determinants of maternal holo TC II concentrations included dietary intake of vitamin B-12 and Giardia lamblia infection. There were no statistically significant determinants of infant UMMA concentrations. We conclude that vitamin B-12 deficiency is highly prevalent in these lactating women and is associated with depletion of the vitamin in their infants. The cause of the maternal deficiency is unknown, but malabsorption exacerbated by low dietary intake of the vitamin is a possibility.

Examining the gender gap in nutrition: an example from rural Mexico

Gender differences in nutrient and food intake were examined in Mexican Nutrition CRSP (Collaborative Research Support Program) infants (N = 75), preschoolers (N = 80), and school children (N = 91). No significant gender differences in dietary quality or quantity were seen for infants and preschoolers. For school children, the contribution of various foods to total energy intake (dietary quality) was also quite similar for girls and boys. Equity in dietary quality remained even under conditions of economic and demographic stress. Nevertheless, school girls consumed significantly less energy per day than boys (-300 kcal/d or 1.3 mJ/d), and less of all micronutrients examined. Gender differences in estimated basal metabolic rates of school children were slight (-20 kcal/d), and body composition and size were similar. When energy intakes were expressed as a percent of estimated requirement (calculated from age, sex and weight using WHO/FAO/UNU equations), intakes were adequate and not significantly different between girls (mean = 111%) and boys (mean = 113%). Playground observations showed girls to be less active than boys, which may reflect both cultural and biological influences. Apparently due to this lower activity, school girls consumed less energy, and may have been at much higher risk than boys of micronutrient deficiency. The lower food intakes of girls did not appear to be due to purposeful dietary discrimination, but rather to culturally patterned sex roles involving lower activity.

Pregnancy and iron deficiency: unresolved issues

Iron deficiency and iron deficiency anemia are prevalent among pregnant women. The extent to which iron deficiency affects maternal and neonatal health is uncertain. Existing data suggest that maternal iron deficiency anemia may be associated with adverse outcomes, including preterm delivery and higher maternal mortality. Further research is needed on the maternal and neonatal benefits of iron supplementation during pregnancy.

Zinc supplementation reduced morbidity, but neither zinc nor iron supplementation affected growth or body composition of Mexican preschoolers

In rural Mexico and in many developing countries micronutrient deficiencies, growth stunting, and morbidity from infectious diseases are highly prevalent in young children. We assessed the extent to which growth stunting could be reversed and the number of infectious disease episodes reduced by zinc and/or iron supplementation. In a double-blind, randomized community trial 219 Mexican preschoolers were supplemented with either 20 mg Zn as zinc methionine, 20 mg Fe as ferrous sulfate, 20 mg Zn + 20 mg Fe, or a placebo. After 12 mo, plasma zinc increased significantly in the two zinc-treated groups, and plasma ferritin was significantly higher in the two iron-treated groups. There was no effect of treatments on growth velocity or body composition. Children in both zinc-supplemented groups had fewer episodes of disease (zinc alone, 3.9 +/- 0.3; zinc+iron, 3.7 +/- 0.4; placebo, 4.6 +/- 0.5; P < 0.03), including diarrhea (zinc alone, 0.7 +/- 0.1; zinc+iron, 0.8 +/- 0.1; placebo, 1.1 +/- 0.2; P < 0.01). Zinc and zinc+iron supplements reduced morbidity but had no effect on growth or body composition.

Determinants of body size perceptions and dieting behavior in a multiethnic group of hospital staff women

OBJECTIVE

This study was designed to identify determinants of body size perceptions and their relationship to dietary behavior in a multiethnic group of women.

DESIGN

A single interview consisting of the Massara and Stunkard body image cards (1979) and questionnaires on sociocultural background, anthropometry, and dieting history were administered to volunteers from the staff of a hospital.

SUBJECTS

The sample was a convenience sample of 186 women representing a range of staff positions recruited from Methodist Hospital in Brooklyn, NY; 174 completed the study. Data on 150 women are presented in this article.

RESULTS

Height and weight-for-height were stronger predictors of accuracy of perceived body size than ethnicity. Tall, slight women were more likely to overestimate and short, heavy women were more likely to underestimate actual body size. Ethnicity had an interactive effect with height as taller European Americans were more likely to perceive their body size as larger than actual compared with Afro-Caribbeans and African Americans. Women with a history of dieting were more likely to overestimate their size and to view it as different from what is perceived as attractive to others.

APPLICATIONS/CONCLUSIONS

Based on the results, we conclude that body size is a stronger predictor of accuracy of perceived body size than ethnicity; and dieters overestimate their body size and believe it to be heavier than their social group would prefer.

Vitamin B-12 deficiency and malabsorption are highly prevalent in rural Mexican communities

Vitamin B-12 status of rural Mexicans was evaluated in two studies, 6 y apart. In the first, a single blood sample was collected from children and adults, including pregnant and lactating women. Prevalence of deficient plasma vitamin B-12 values ranged from 19% to 41% among groups, but plasma folate status was normal in all individuals. Breast milk vitamin B-12 concentration was low in 62% of samples. The second study was conducted in 219 children aged 18-36 mo in five communities, whose prevalence of deficient and low plasma vitamin B-12 concentrations, respectively, was 8% and 33% on entry, 3% and 22% 6 mo later, and 7% and 29% 12 mo later. Prevalence of low holotranscobalamin II concentrations, indicating malabsorption of the vitamin, averaged 18-40% across the three same periods. Both vitamin B-12 status indicators differed significantly between communities. The widespread vitamin B-12 deficiency was probably caused by malabsorption, perhaps exacerbated by low dietary intake and, for young children, maternal depletion of the vitamin.

A role for MARCKS, the alpha isozyme of protein kinase C and myosin I in zymosan phagocytosis by macrophages

Myristoylated, alanine-rich C-kinase substrate (MARCKS) is a lipopolysaccharide-induced protein kinase C (PKC) substrate that has been proposed to regulate actin-membrane interactions, as well as actin structure at the membrane. We studied the distribution of MARCKS, the alpha isozyme of PKC (PKC alpha), and myosin I in lipopolysaccharide-treated peritoneal macrophages ingesting zymosan particles. MARCKS, PKC alpha, and myosin I colocalized with F-actin and talin in the cortical cytoplasm adjacent to forming phagocytic cups. After particle ingestion was completed, myosin I, F-actin, and talin were no longer enriched in the vicinity of the phagosome. By contrast, MARCKS and PKC alpha remained associated with the phagosome membrane until after acquisition of the lysosomal marker Lamp-1. Vinculin was not detected on phagosomes at any time point examined. Phagocytosis of zymosan was accompanied by rapid and sustained phosphorylation of MARCKS. Inhibitors of PKC reduced zymosan binding to the macrophage surface and blocked the focal accumulation of F-actin, talin, phosphotyrosine-containing proteins, MARCKS, and PKC alpha beneath attached particles. We propose that PKC-dependent phosphorylation is an early signal required for zymosan phagocytosis and that MARCKS and PKC alpha have a role in phagosome maturation. The colocalization of F-actin and MARCKS at the cytoplasmic face of the nascent phagosome reinforces the hypothesis that MARCKS regulates actin structure at the membrane. Our data also suggest that myosin I functions as a mechanical motor during particle uptake.

Vicryl-mesh wrap for the implantation of hydroxyapatite orbital implants: an animal model

OBJECTIVE

To evaluate host fibrovascularization of hydroxyapatite orbital implants wrapped in sclera or in Vicryl (polyglactin 910) mesh in a rabbit model.

NUMBERS

Eight adult New Zealand white rabbits that received hydroxyapatite orbital implants wrapped in homologous donor sclera (four animals) or Vicryl mesh (four animals).

INTERVENTIONS

The rabbits had one eye enucleated and then received a 12-mm hydroxyapatite implant wrapped in sclera or Vicryl mesh. Magnetic resonance imaging (MRI) and bone scintigraphy were done to assess host fibrovascularization of the implant 4, 8, 12 and 20 weeks after implantation. Two animals (one in each group) were killed at each of these times, and the implant was removed for histopathological examination.

MAIN OUTCOME MEASURES

Enhancement on MRI, uptake on bone scintigraphy, fibrovascularization seen on histopathological examination.

RESULTS

The degree of fibrovascularization was substantial in all the specimens but appeared greater in the Vicryl-mesh-wrapped implants in the first 12 weeks after implantation on both histopathological and MRI studies. At 20 weeks these findings were similar in the two groups. A granulomatous foreign-body giant-cell reaction to both the Vicryl mesh and the implant itself was present up to 8 weeks after implantation. Bone scans showed only grade 1+ activity in all the implants.

CONCLUSIONS

Host fibrovascularization in the rabbit appears to occur to a greater degree in Vicryl-mesh-wrapped hydroxyapatite implants than in those wrapped in donor sclera during the first 12 weeks after implantation. Vicryl mesh appears to be an acceptable alternative wrap for the hydroxyapatite implant, eliminating the need for donor sclera and its potential risks of transmissible diseases.

The use of Vicryl mesh (polyglactin 910) for implantation of hydroxyapatite orbital implants

Hydroxyapatite (HA) implants currently are most commonly wrapped in donor sclera before implantation to facilitate placement within the orbit and allow attachment of the extraocular muscles. Although the risk of acquiring a transmittable disease through donor sclera is extremely low, some individuals remain concerned about receiving nonautologous material. As an alternative to sclera, autologous temporalis fascia, or autologous fascia lata, we have been wrapping HA in "Vicryl mesh" before insertion into the orbit. The Vicryl mesh-wrapped implant goes into the socket readily, allows one to easily attach the extraocular muscles, and has no risk of transmittable disease. In addition, the Vicryl mesh is readily available at most hospitals and is dissolvable.

Malnutrition and human function: a comparison of conclusions from the INCAP and nutrition CRSP studies

The overall objective of both the Institute of Nutrition of Central America and Panama (INCAP) studies and the Nutrition Collaborative Research Support Program (CRSP) was to determine if marginal malnutrition affects human function. The conclusions from the two studies were consistent, notably that growth stunting occurs early in life and is accompanied by functional impairments. These consequences of early malnutrition persist later in life. The comparison of INCAP and Nutrition CRSP results also illustrates that the Guatemalan children were more malnourished and stunted than those in Kenya, Mexico or Egypt and that this greater degree of stunting occurs before 18 months of age. Even the Atole did not bring the average size of supplemented children in Guatemala up to those of the unsupplemented children in the CRSP populations. It is also likely that their functional potential was not realized fully by supplementation. The CRSP studies provide evidence of multiple micronutrient deficiencies associated with poor growth and function and it is probable that these associations exist in Guatemala as well. The overall conclusion is that our attention should be directed to determining the adequacy of micronutrient status in the perinatal period and to the development of approaches that prevent early growth failure.