bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of economic inequality on chronic childhood undernutrition in Ghana
Authors: Hong Rathavuth 
Published: March 2007

AbstractObjectiveFood insecurity and undernutrition remain particularly severe in developing countries where improvements in economic conditions have tended to benefit the advantaged groups and resulted in widespread inequalities in health. This study examined how economic inequality is associated with chronic childhood undernutrition.DesignA child was defined as chronically undernourished (stunted) if his or her height-for-age index was more than two standard deviations below the reference median. Household economic status was measured by an index based on household ownership of durable assets. Bivariate and multivariate analyses were used to estimate the effects of household economic status on stunting.SettingA nationally representative sample of 6251 household interviews in Ghana.SubjectsA total of 3077 children aged 0–59 months included in the 2003 Ghana Demographic and Health Survey.ResultsChildren in the poorest 20% of households are more than twice as likely to suffer from stunting as children in the richest 20% of households independent of the child's age, sex, birth order, breast-feeding duration, birth weight; mother's age at childbirth, body mass index, education; and household access to safe drinking water, hygienic toilet facilities, residence and geographic region (odds ratio = 2.3; 95% confidence interval 1.4–3.7). Also children in the next poorest and in the middle quintiles are significant more likely to be chronically undernourished than children in the richest 20% of households.ConclusionThis study concludes that economic inequality is strongly associated with chronic childhood undernutrition; and reducing economic inequalities and making services more accessible to the poor will be key to improving the health and nutritional status of children in Ghana.
Inadequate dietary intake is not the cause of stunting amongst young children living in an informal settlement in Gauteng and rural Limpopo Province in South Africa: the NutriGro study
Authors: Theron M , Amissah A , Kleynhans IC , Albertse E , MacIntyre UE 
Published: March 2007

AbstractObjectiveTo measure dietary intakes of young children aged 12–24 months and to determine the impact of poor diets on stunting.DesignA quantitative food-frequency questionnaire was adapted, tested and standardised. Trained enumerators conducted in-depth interviews with the mothers/caregivers of the children. Forty stunted children in urban informal settlements and 30 stunted children in rural areas were selected and pair-matched with controls. The data were captured on the Food Finder Program of the Medical Research Council.ResultsIn both urban and rural areas, the diet of stunted and non-stunted groups did differ significantly and all diets were of poor nutritional quality.ConclusionDiets in both areas resembled the recommended prudent diet, i.e. low in fat and high in carbohydrates. Poor quality diets were not the primary cause of stunting.
Lifecourse, immigrant status and acculturation in food purchasing and preparation among low-income mothers
Authors: Dubowitz Tamara , Acevedo-Garcia Dolores , Salkeld Judy , Cristina Lindsay Ana , Subramanian SV , Peterson Karen E 
Published: March 2007

AbstractObjectivesThis study investigates how lifecourse, immigrant status and acculturation, and neighbourhood of residence influence food purchasing and preparation among low-income women with children, living in the USA. This research sought to understand physical and economic access to food, from both ‘individual’ and ‘community’ perspectives.DesignThis study used qualitative methodology (focus groups) to examine the mechanisms and pathways of food preparation and purchasing within the context of daily life activity for US- and foreign-born women, living in the USA. The study methodology analysed notes and verbatim transcripts, summarised recurring responses and identified new themes in the discussions.Setting and subjectsA total of 44 women were purposively sampled from two metropolitan areas in Massachusetts, USA, based on (1) neighbourhood of residence and (2) primary language spoken. All focus groups were conducted in community health centres and community centres co-located with offices of the special supplemental nutritional programme for Women, Infants, and Children.ResultsAnalysis of key response themes suggested that scarcity of food and physical access to food purchasing points did not influence food purchasing and preparation as much as (1) limited time for food shopping, cooking and family activities; and (2) challenges in transportation to stores and childcare. The study results demonstrated differing attitudes toward food acquisition and preparation between immigrant and US-born women and between women who lived in two metropolitan areas in the western and eastern regions of the state of Massachusetts, USA.ConclusionsThe findings illustrate ‘hidden’ constraints that need to be captured in measures of physical and economic access and availability of food. US policies and programmes that aim to improve access, availability and diet quality would benefit from considering the social context of food preparation and purchasing, and the residential environments of low-income women and families.
Hunger in young children of Mexican immigrant families
Authors: Kersey Margaret , Geppert Joni , Cutts Diana B 
Published: March 2007

AbstractObjectiveTo measure rates of hunger and food insecurity among young US-born Latino children with Mexican immigrant parents (Latinos) compared with a non-immigrant non-Latino population (non-Latinos) in a low-income clinic population.Design, setting and subjectsA repeated cross-sectional survey of 4278 caregivers of children < 3 years of age in the paediatric clinic of an urban county hospital for a 5-year period from 1998 to 2003. A total of 1310 respondents had a US-born child with at least one parent born in Mexico. They were compared with a reference group comprised of non-Latino US-born participants (n = 1805). Child hunger and household food insecurity were determined with the US Household Food Security Scale.ResultsYoung Latino children had much higher rates of child hunger than non-Latinos, 6.8 versus 0.5%. Latino families also had higher rates of household food insecurity than non-Latinos, 53.1 versus 15.6%. Latino children remained much more likely to be hungry (odds ratio (OR) = 13.0, 95% confidence interval (CI) = 5.9–28.7,P < 0.01) and in household food-insecure households (OR = 6.6, 95% CI = 5.2–8.3,P< 0.01) than non-Latinos after controlling for the following variables in multivariate analysis: child's age, sex, maternal education level, single-headed household status, family size, young maternal age ( < 21 years), food stamp programme participation, TANF (Temporary Assistance to Needy Families, or ‘welfare’) programme participation and WIC (Women, Infants, and Children) usage, and reason for clinic visit (sick visit versus well-child).ConclusionYoung children in Mexican immigrant families are at especially high risk for hunger and household food insecurity compared with non-immigrant, non-Latino patients in a low-income paediatric clinic.
Early introduction of water and complementary feeding and nutritional status of children in northern Senegal
Authors: Gupta Neil , Gehri Mario , Stettler Nicolas 
Published: March 2007

AbstractObjectiveMalnutrition is responsible globally for 60% of deaths among children under 5 years and is often attributed to suboptimal feeding practices. In response, the World Health Organization recommends exclusive breast-feeding for the first 6 months of life. The objective of this study was to determine if an association exists between the early introduction of water and complementary foods (CFs) and the nutritional status of children in northern Senegal.Design/Setting/SubjectsA cross-sectional study of 374 children in the Podor Health District between the ages of 6 and 23 months was conducted. Knowledge and behaviours of mothers regarding introduction of water and CFs were assessed via individual interviews.ResultsWater was introduced to about 85% of the children in the first 3 months of life and 62% were fed CFs before 6 months. Overall, 16% had clinically significant wasting (weight-for-length Z-score (WHZ) less than − 2) and 20% had stunting (height-for-age Z-score (HAZ) less than − 2). There was no significant association between wasting or stunting and introduction of water before 3 months (WHZ: odds ratio = 0.99, 95% confidence interval 0.46–2.14, P = 0.97; HAZ: 0.68, 0.34–1.36, P = 0.3) or introduction of CFs before 6 months (WHZ: 0.81, 0.46–1.42, P = 0.5; HAZ: 0.79, 0.46–1.35, P = 0.4). A significant association was found between wasting and male sex, age, living in Guede community, drinking river/pond water and large family size, while stunting was associated with age and drinking tap water.ConclusionThe results of the present study suggest that early introduction of water and CFs is frequent and is not associated with increased risk for malnutrition among children from this region of northern Senegal, but the possibility of reverse causality cannot be excluded.
Improving the nutritional status of food-insecure women: first, let them eat what they like
Authors: McIntyre Lynn , Tarasuk Valerie , Jinguang Li Tony 
Published: March 2007

AbstractObjectiveTo determine the extent to which identified nutrient inadequacies in the dietary intakes of a sample of food-insecure women could be ameliorated by increasing their access to the ‘healthy’ foods they typically eat.DesignMerged datasets of 226 food-insecure women who provided at least three 24-hour dietary intake recalls over the course of a month. Dietary modelling, with energy adjustment for severe food insecurity, explored the effect of adding a serving of the woman's own, and the group's typically chosen, nutrient-rich foods on the estimated prevalence of nutrient inadequacy.Setting and subjectsOne study included participants residing in 22 diverse community clusters from the Atlantic Provinces of Canada, and the second study included food bank attendees in Toronto, Ontario, Canada. Of the 226 participants, 78% lived alone with their children.ResultsWhile nutritional vulnerability remained after modelling, adding a single serving of either typically chosen ‘healthy’ foods from women's own diets or healthy food choices normative to the population reduced the prevalence of inadequacy by at least half for most nutrients. Correction for energy deficits resulting from severe food insecurity contributed a mean additional 20% improvement in nutrient intakes.ConclusionsFood-insecure women would sustain substantive nutritional gains if they had greater access to their personal healthy food preferences and if the dietary compromises associated with severe food insecurity were abated. Increased resources to access such choices should be a priority.
Cytoskeletal transition at the paranodes: the Achilles' heel of myelinated axons
Authors: Sousa Aurea D. , Bhat Manzoor A. 
Published: March 2007

AbstractMyelination organizes axons into distinct domains that allow nerve impulses to propagate in a saltatory manner. The edges of the myelin sheath are sealed at the paranodes by axon–glial junctions that have a crucial role in organizing the axonal cytoskeleton. Here we propose a model in which the myelinated axons depend on the axon–glial junctions to stabilize the cytoskeletal transition at the paranodes. Thus paranodal regions are likely to be particularly susceptible to damage induced by demyelinating diseases such as multiple sclerosis.
FGF4 regulates blood and muscle specification in Xenopus laevis
Authors: Isaacs Harry V. , Deconinck Anne E. , Pownall Mary E. 
Published: March 2007

Background information. FGF (fibroblast growth factor) signalling is known to be required for many aspects of mesoderm formation and patterning during Xenopus development and has been implicated in regulating genes required for the specification of both blood and skeletal muscle lineages.Results. In the present study, we have specifically knocked down the expression of FGF4 using AMO (antisense morpholino oligonucleotide)‐mediated inhibition and demonstrate that FGF4 acts in the dorsal marginal zone to restrict blood development and promote the development of skeletal muscle. In addition, we used a drug inhibitor of FGF signalling and an inducible form of FGFR1 (FGF receptor 1) to identify a period of competence during late blastula and gastrula stages when FGF signalling acts to regulate blood versus muscle specification. Notably, we found that it is the dorsal activity of FGF that is required to restrict the expression of SCL (stem cell leukaemia) to the ventral blood island.Conclusions. Our data indicate that FGF4 is a key organizer‐derived signal involved in the process of dorsoventral patterning of the mesoderm.
Comparative functional analysis of human medium-chain dehydrogenases, short-chain dehydrogenases/reductases and aldo-keto reductases with retinoids
Authors: Gallego Oriol , Belyaeva Olga V. , Porté Sergio , Ruiz F. Xavier , Stetsenko Anton V. , Shabrova Elena V. , Kostereva Natalia V. , Farrés Jaume , Parés Xavier , Kedishvili Natalia Y. 
Published: March 2007

Retinoic acid biosynthesis in vertebrates occurs in two consecutive steps: the oxidation of retinol to retinaldehyde followed by the oxidation of retinaldehyde to retinoic acid. Enzymes of the MDR (medium-chain dehydrogenase/reductase), SDR (short-chain dehydrogenase/reductase) and AKR (aldo-keto reductase) superfamilies have been reported to catalyse the conversion between retinol and retinaldehyde. Estimation of the relative contribution of enzymes of each type was difficult since kinetics were performed with different methodologies, but SDRs would supposedly play a major role because of their low Km values, and because they were found to be active with retinol bound to CRBPI (cellular retinol binding protein type I). In the present study we employed detergent-free assays and HPLC-based methodology to characterize side-by-side the retinoid-converting activities of human MDR [ADH (alcohol dehydrogenase) 1B2 and ADH4), SDR (RoDH (retinol dehydrogenase)-4 and RDH11] and AKR (AKR1B1 and AKR1B10) enzymes. Our results demonstrate that none of the enzymes, including the SDR members, are active with CRBPI-bound retinoids, which questions the previously suggested role of CRBPI as a retinol supplier in the retinoic acid synthesis pathway. The members of all three superfamilies exhibit similar and low Km values for retinoids (0.12–1.1 μM), whilst they strongly differ in their kcat values, which range from 0.35 min−1 for AKR1B1 to 302 min−1 for ADH4. ADHs appear to be more effective retinol dehydrogenases than SDRs because of their higher kcat values, whereas RDH11 and AKR1B10 are efficient retinaldehyde reductases. Cell culture studies support a role for RoDH-4 as a retinol dehydrogenase and for AKR1B1 as a retinaldehyde reductase in vivo.
Hydrolysis of (1,4)-β-D-mannans in barley (Hordeum vulgare L.) is mediated by the concerted action of (1,4)-β-D-mannan endohydrolase and β-D-mannosidase
Authors: Hrmova Maria , Burton Rachel A. , Biely Peter , Lahnstein Jelle , Fincher Geoffrey B. 
Published: March 2007

A family GH5 (family 5 glycoside hydrolase) (1,4)-β-D-mannan endohydrolase or β-D-mannanase (EC 3.2.1.78), designated HvMAN1, has been purified 300-fold from extracts of 10-day-old barley (Hordeum vulgare L.) seedlings using ammonium sulfate fractional precipitation, followed by ion exchange, hydrophobic interaction and size-exclusion chromatography. The purified HvMAN1 is a relatively unstable enzyme with an apparent molecular mass of 43 kDa, a pI of 7.8 and a pH optimum of 4.75. The HvMAN1 releases Man (mannose or D-mannopyranose)-containing oligosaccharides of degree of polymerization 2–6 from mannans, galactomannans and glucomannans. With locust-bean galactomannan and mannopentaitol as substrates, the enzyme has Km constants of 0.16 mg·ml−1 and 5.3 mM and kcat constants of 12.9 and 3.9 s−1 respectively. Product analyses indicate that transglycosylation reactions occur during hydrolysis of (1,4)-β-D-manno-oligosaccharides. The complete sequence of 374 amino acid residues of the mature enzyme has been deduced from the nucleotide sequence of a near full-length cDNA, and has allowed a three-dimensional model of the HvMAN1 to be constructed. The barley HvMAN1 gene is a member of a small (1,4)-β-D-mannan endohydrolase family of at least six genes, and is transcribed at low levels in a number of organs, including the developing endosperm, but also in the basal region of young roots and in leaf tips. A second barley enzyme that participates in mannan depolymerization through its ability to hydrolyse (1,4)-β-D-manno-oligosaccharides to Man is a family GH1 β-D-mannosidase, now designated HvβMANNOS1, but previously identified as a β-D-glucosidase [Hrmova, MacGregor, Biely, Stewart and Fincher (1998) J. Biol. Chem. 273, 11134–11143], which hydrolyses 4NP (4-nitrophenyl) β-D-mannoside three times faster than 4NP β-D-glucoside, and has an action pattern typical of a (1,4)-β-D-mannan exohydrolase.
Age-related accumulation of pentosidine in aggrecan and collagen from normal and degenerate human intervertebral discs
Authors: Sivan Sarit Sara , Tsitron Eve , Wachtel Ellen , Roughley Peter , Sakkee Nico , van der Ham Frits , Degroot Jeroen , Maroudas Alice 
Published: March 2007

During aging and degeneration, many changes occur in the structure and composition of human cartilaginous tissues, which include the accumulation of the AGE (advanced glycation end-product), pentosidine, in long-lived proteins. In the present study, we investigated the accumulation of pentosidine in constituents of the human IVD (intervertebral disc), i.e. collagen, aggrecan-derived PG (proteoglycan) (A1) and its fractions (A1D1–A1D6) in health and pathology. We found that, after maturity, pentosidine accumulates with age. Over the age range studied, a linear 6-fold increase was observed in pentosidine accumulation for A1 and collagen with respective rates of 0.12 and 0.66 nmol·(g of protein)−1·year−1. Using previously reported protein turnover rate constants (kT) obtained from measurements of the D-isomer of aspartic residue in collagen and aggrecan of human IVD, we could calculate the pentosidine formation rate constants (kF) for these constituents [Sivan, Tsitron, Wachtel, Roughley, Sakkee, van der Ham, DeGroot, Roberts and Maroudas (2006) J. Biol. Chem. 281, 13009–13014; Tsitron (2006) MSc Thesis, Technion-Israel Institute of Technology, Haifa, Israel]. In spite of the comparable formation rate constants obtained for A1D1 and collagen [1.81±0.25 compared with 3.71±0.26 μmol of pentosidine·(mol of lysine)−1·year−1 respectively], the higher pentosidine accumulation in collagen is consistent with its slower turnover (0.005 year−1 compared with 0.134 year−1 for A1D1). Pentosidine accumulation increased with decreasing buoyant density and decreasing turnover of the proteins from the most glycosaminoglycan-rich PG components (A1D1) to the least (A1D6), with respective kF values of 1.81±0.25 and 3.18±0.37 μmol of pentosidine·(mol of lysine)−1·year−1. We concluded that protein turnover is an important determinant of pentosidine accumulation in aggrecan and collagen of human IVD, as was found for articular cartilage. Correlation of pentosidine accumulation with protein half-life in both normal and degenerate discs further supports this finding.
Modulation of inhibition of ferrochelatase by N-methylprotoporphyrin
Authors: Shi Zhen , Ferreira Gloria C. 
Published: March 2007

Protoporhyrin IX ferrochelatase catalyses the terminal step of the haem-biosynthetic pathway by inserting ferrous iron into protoporphyrin IX. NMPP (N-methylprotoporphyrin), a transition-state analogue and potent inhibitor of ferrochelatase, is commonly used to induce haem deficiency in mammalian cell cultures. To create ferrochelatase variants with different extents of tolerance towards NMPP and to understand further the mechanism of ferrochelatase inhibition by NMPP, we isolated variants with increased NMPP resistance, bearing mutations in an active-site loop (murine ferrochelatase residues 248–257), which was previously shown to mediate a protein conformational change triggered by porphyrin binding. The kinetic mechanisms of inhibition of two variants, in which Pro255 was replaced with either arginine (P255R) or glycine (P255G), were investigated and compared with that of wild-type ferrochelatase. While the binding affinity of the P255X variants for NMPP decreased by one order of magnitude in relation to that of wild-type enzyme, the inhibition constant increased by approximately two orders of magnitude (Kiapp values of 1 μM and 2.3 μM for P255R and P255G respectively, as against 3 nM for wild-type ferrochelatase). Nonetheless, the drastically reduced inhibition of the variants by NMPP was not paralleled with a decrease in specificity constant (kcat/Km, protoporhyrin IX) and/or catalytic activity (kcat). Further, although NMPP binding to either wild-type ferrochelatase or P255R occurred via a similar two-step kinetic mechanism, the forward and reverse rate constants associated with the second and rate-limiting step were comparable for the two enzymes. Collectively, these results suggest that Pro255 has a crucial role in maintaining an appropriate protein conformation and modulating the selectivity and/or regiospecificity of ferrochelatase.
Critical roles for p22phox in the structural maturation and subcellular targeting of Nox3
Authors: Nakano Yoko , Banfi Botond , Jesaitis Algirdas J. , Dinauer Mary C. , Allen Lee-Ann H. , Nauseef William M. 
Published: March 2007

Otoconia are small biominerals in the inner ear that are indispensable for the normal perception of gravity and motion. Normal otoconia biogenesis requires Nox3, a Nox (NADPH oxidase) highly expressed in the vestibular system. In HEK-293 cells (human embryonic kidney cells) transfected with the Nox regulatory subunits NoxO1 (Nox organizer 1) and NoxA1 (Nox activator 1), functional murine Nox3 was expressed in the plasma membrane and exhibited a haem spectrum identical with that of Nox2, the electron transferase of the phagocyte Nox. In vitro Nox3 cDNA expressed an ∼50 kDa primary translation product that underwent N-linked glycosylation in the presence of canine microsomes. RNAi (RNA interference)-mediated reduction of endogenous p22phox, a subunit essential for stabilization of Nox2 in phagocytes, decreased Nox3 activity in reconstituted HEK-293 cells. p22phox co-precipitated not only with Nox3 and NoxO1 from transfectants expressing all three proteins, but also with NoxO1 in the absence of Nox3, indicating that p22phox physically associated with both Nox3 and with NoxO1. The plasma membrane localization of Nox3 but not of NoxO1 required p22phox. Moreover, the glycosylation and maturation of Nox3 required p22phox expression, suggesting that p22phox was required for the proper biosynthesis and function of Nox3. Taken together, these studies demonstrate critical roles for p22phox at several distinct points in the maturation and assembly of a functionally competent Nox3 in the plasma membrane.