Zinc deficiency in selected cultivars of wheat and barley as tested in solution culture

The relative zinc (Zn) efficiencies of 33 wheat and 3 barley cultivars were determined by growing them in chelate-buffered culture solutions. Zn efficiency, determined by growth in a Zn-deficient solution relative to that in a medium containing an adequate concentration of Zn, was found to vary between 10% and 63% among the cultivars tested. Out of the 36 cultivars tested, 12 proved to be Zn efficient, 10 were Zn inefficient, and the remaining 14 varieties were classed as intermediate. The most Zn-efficient cultivars included Bakhtawar, Gatcher S61, Wilgoyne, and Madrigal, and the most Zn inefficient included Durati, Songlen, Excalibur, and Chakwal-86. Zn-efficient cultivars accumulated greater amounts of Zn in their shoots than inefficient cultivars, but the correlation between shoot Zn and shoot dry matter production was poor. All the cultivars accumulated higher concentrations of iron (Fe), copper (Cu), manganese (Mn), and phosphorus (P) at deficient levels of Zn, compared with adequate Zn concentrations. The Zn-inefficient cultivars accumulated higher concentrations of these other elements compared to efficient cultivars.

The illusion of environmental iodine deficiency

The distribution of endemic goitre in England and Wales was compared with the distribution of environmental iodine (atmospheric deposition, soil, surface water). Despite a very clear goitre belt through the west of England and Wales there was no patterning in the environmental iodine distribution. A clear seasonal variation in depositional iodine exists, with an unusually high concentration of iodine in March 1997. The temporal variation in iodine concentration is determined at the monthly and not the annual level. The presence of endemic goitre is no indicator of how iodine is distributed in the environment or vice versa!

Will rising household incomes solve China's micronutrient deficiency problems?

Rapid economic growth in China has resulted in substantially improved household incomes. Diets have also changed, with a movement away from traditional foods and towards animal products and processed foods. Yet micronutrient deficiencies, particularly for calcium and vitamin A, are still widespread in China. In this research we model the determinants of the intakes of these micronutrients using household panel data, asking particularly whether continuing income increases are likely to cause the deficiencies to be overcome. Nonparametric kernel regressions and random effects panel regression models are employed. The results show a statistically significant but relatively small positive income effect on both nutrient intakes. The local availability of milk is seen to have a strong positive effect on intakes of both micronutrients. Thus, rather than relying on increasing incomes to overcome deficiencies, supplementary government policies, such as school milk programmes, may be warranted.

Towards the use of hydrogels in the treatment of limbal stem cell deficiency

Corneal blindness caused by limbal stem cell deficiency (LSCD) is a prevailing disorder worldwide. Clinical outcomes for LSCD therapy using amniotic membrane (AM) are unpredictable. Hydrogels can eliminate limitations of standard therapy for LSCD, because they present all the advantages of AM (i.e. biocompatibility, inertness and a biodegradable structure) but unlike AM, they are structurally uniform and can be easily manipulated to alter mechanical and physical properties. Hydrogels can be delivered with minimum trauma to the ocular surface and do not require extensive serological screening before clinical application. The hydrogel structure is also amenable to modifications which direct stem cell fate. In this focussed review we highlight hydrogels as biomaterial substrates which may replace and/or complement AM in the treatment of LSCD.

Genetic responses to phosphorus deficiency

Background: Phosphorus (P) is an essential macronutrient for plants. Plants take up P as phosphate (Pi) from the soil solution. Since little Pi is available in most soils, P fertilizers are applied to crops. However, the use of P fertilizers is unsustainable and may cause pollution. Consequently, there is a need to develop more P-use-efficient (PUE) crops and precise methods to monitor crop P-status. Scope: Manipulating the expression of genes to improve the PUE of crops could reduce their P fertilizer requirement. This has stimulated research towards the identification of genes and signalling cascades involved in plant responses to P deficiency. Genes that respond to P deficiency can be grouped into 'early' genes that respond rapidly and often non-specifically to P deficiency, or 'late' genes that impact on the morphology, physiology or metabolism of plants upon Prolonged P deficiency. Summary: The use of micro-array technology has allowed researchers to catalogue the genetic responses of plants to P deficiency. Genes whose expression is altered by P deficiency include various transcription factors, which are thought to coordinate plant responses to P deficiency, and other genes involved in P acquisition and tissue P economy. Several common cis-regulatory elements have been identified in the promoters of these genes, suggesting that their expression might be coordinated. It is suggested that knowledge of the genes whose expression changes in response to P deficiency might allow the development of crops with improved PUE, and could be used in diagnostic techniques to monitor P deficiency in crops either directly using 'smart' indicator plants or indirectly through transcript profiling. The development of crops with improved PUE and the adoption of diagnostic technology could reduce production costs, minimize the use of a non-renewable resource, reduce pollution and enhance biodiversity.

Response to zinc deficiency of two rice lines with contrasting tolerance is determined by root growth maintenance and organic acid exudation rates, and not by zinc-transporter activity

Zinc (Zn)-deficient soils constrain rice (Oryza sativa) production and cause Zn malnutrition. The identification of Zn-deficiency-tolerant rice lines indicates that breeding might overcome these constraints. Here, we seek to identify processes underlying Zn-deficiency tolerance in rice at the physiological and transcriptional levels. A Zn-deficiency-tolerant line RIL46 acquires Zn more efficiently and produces more biomass than its nontolerant maternal line (IR74) at low Zn(ext) under field conditions. We tested if this was the result of increased expression of Zn(2+) transporters; increased root exudation of deoxymugineic acid (DMA) or low-molecular-weight organic acids (LMWOAs); and/or increased root production. Experiments were performed in field and controlled environment conditions. There was little genotypic variation in transcript abundance of Zn-responsive root Zn(2+)-transporters between the RIL46 and IR74. However, root exudation of DMA and LMWOA was greater in RIL46, coinciding with increased root expression of putative ligand-efflux genes. Adventitious root production was maintained in RIL46 at low Zn(ext), correlating with altered expression of root-specific auxin-responsive genes. Zinc-deficiency tolerance in RIL46 is most likely the result of maintenance of root growth, increased efflux of Zn ligands, and increased uptake of Zn-ligand complexes at low Zn(ext); these traits are potential breeding targets.

Evidence for a genetic interaction in allergy-related responsiveness to vitamin D deficiency

Our study on white European adults was consistent with a previous study on children from largely non-white ethnic groups, suggesting that IL4 and MS4A2 genotypes modify the association between VDD and allergy risk. The risk allele in IL4 is present in nearly 90% of white Europeans, while less than a quarter are carriers in some other populations, highlighting the need to consider possible ethnic differences in allergy-related responsiveness to VDD.

Iron deficiency anaemia and blood lead concentrations in Brazilian children

This study investigated the relationship between iron deficiency/iron deficiency anaemia, assessed by several parameters, and blood lead concentration in children. This cross-sectional study involved 384 Brazilian children, aged 2-11 years, who lived near a lead-manipulating industry. Complete blood counts were obtained by an automated cell counter. Serum iron, total iron binding capacity (TIBC) and ferritin were determined respectively, by colorimetric, turbidimetric methods and chemiluminescence. Blood lead was measured by atomic absorption spectrophotometry. The impact of several parameters for assessment of iron status (haemoglobin, serum iron, TIBC, transferrin saturation, ferritin, red cell indices and red cell distribution width) and variables (gender, age, mother`s education, income, body mass index, iron intake, and distance from home to lead-manipulating industry) on blood lead concentration was determined by multiple linear regression. There were significant negative associations between blood lead and the distance from home to the lead-manipulating industry (P < 0.001), Hb (P = 0.019), and ferritin (P=0.023) (R(2)=0.14). Based on these results, further epidemiological studies are necessary to investigate the impact of interventions like iron supplementation or fortification, as an attempt to decrease blood lead in children. (C) 2011 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

Vitamin A deficiency in preschool children of Recife, Northeast of Brazil

Vitamin A deficiency in preschool children of Recife, Northeast of Brazil. The purpose of the study was to evaluate the extent of vitamin A deficiency (VAD) among preschool children in the city of Recife, Northeast Brazil. The sample comprised 344 children of both sexes, 24 to 60 months old, in 18 public day care centres in the city of Recife, in 2007. The nutritional status of vitamin A was assessed by biochemical (serum retinol) and dietetic (vitamin A rich-food consumption) indicators and the pondo-stature status through anthropometric indicators weight-for-age, height-for-age and weight-for-height. The prevalence of hyporetinolemia (<0.70 mu mol / L) was 7.7% (IC95% 4.88 - 11.81), which characterizes the VAD as a light-type public health problem, according to World Health Organization criteria. On the other hand, 29.6% (IC95% 24.22 - 35.63) of children had acceptable or marginal levels (0.70 to 1.04 mu mol/L) of retinol. Regarding the vitamin A rich-food intake, values below the EAR (Estimated Average Requirement) - 210 mu g/day for children of 1 to 3 years old and 275 mu g/day for children of 4 to 8 years old - were 8.1% and 21.3% respectively. The prevalence of anthropometrical deficits (<-2 scores -Z) in preschool children were 2.5% for the indicator weight-for-age, 8.6% for height-for-age and 1.5% for weight-for-height. The research findings point out to the importance of institutionalization for the appropriate nutritional status of children and maintenance of adequate reserves of vitamin A. However, more studies are needed focusing on non-institutionalized preschool, or children living outside the privileged environment of public day care centres.

Fortified food made by the extrusion of a mixture of chickpea, corn and bovine lung controls iron-deficiency anaemia in preschool children

A fortified food that was rich in protein, vitamins and iron made of chickpea, bovine lung and corn was developed with the aim of controlling iron-deficiency anaemia in children from poorer areas. It was tested in Teresina, State of Piaui, Northeastern Brazil, on a population with high anaemia prevalence. Two local daycare units with similar characteristics were selected and the children at one of them received a 30 g pack three times a week, representing a total iron daily intake of 6.96 mg. The other daycare unit was followed as a control. The capillary haemoglobin concentration was determined for the children at both daycare units, at the beginning of the study and after a two-month intervention period. The mean haemoglobin concentration in the test group at the beginning of the intervention was 11.8 g/dL, which increased to 13.1 g/dL at the end of the intervention. In the control group these figures remained practically constant (11.6-11.8 g/dL). These represented a dramatic and significant drop in anaemia prevalence, from 61.5% to 11.5% in the test group, and an insignificant reduction (63.1-57.7%) in the control group. The acceptance of the fortified snack was excellent and no undesirable effects were observed. (C) 2007 Published by Elsevier Ltd.