[Prevalence of cryptosporidiosis in pediatric hospital patients in Niamey, Niger]. / Prévalence de la cryptosporidiose en milieu hospitalier pédiatrique à Niamey, Niger.

No data has been published, so far about the prevalence of cryptosporidiosis among children in Niger; a landlocked country of West Africa where malnutrition and diarrhoea are two major public health issues. The aim of the present study was to get a first evaluation of the prevalence of Cryptosporidium sp in the stools of hospitalized children in the National Hospital of Niamey (NHN) where we carried out a prospective descriptive study involving all children younger than 5 years of age in the paediatric department between February 21st and May 22nd, 2004. Direct stool examination and Ritchie technique were systematically performed, and evidence of Cryptosporidium oocysts was looked for by means of a smear from the sediment which was stained by the modified Ziehl-Neelsen technique. The weight/age ratio was calculated and analyzed with the Epi-Info software, based on the reference population defined by the US National Center for Health Statistics (NCHS). Malnutrition was defined as a weight/age ratio more than 2 SD below the NCHS's reference population. Malnutrition was considered moderate between -2 and -3 SD and severe below 3 SD. In the 3 months study 220 children were included (sex ratio = 1.18 and mean age = 20 months) showing that 65% of the children were suffering from malnutrition (moderate = 17.3%, severe = 47%). Diarrhoea was reported in 51.8% of the children. Cryptosporidium oocysts were detected in 12/220 children (5.5% of the studied population) and 7/114 (6. 1%) of those children were suffering from diarrhoea. 10 (83%) out of the 12 infected children were malnourished. This was the first study ever conducted in the paediatric department of the Niamey hospital, and it showed evidence of a 5.5% prevalence of cryptosporidiosis in the overall studied population, versus 6.1% among children with diarrhoea. 5 children without diarrhoea and 2 children under 6 months were also infected. Another study based on a larger number of patients would be necessary to address the impact of rainfall distribution on the incidence of the disease.

Low-cost diets: more energy, fewer nutrients.

Energy-dense diets offer a low-cost dietary option to the consumer. However, they are more likely to be nutrient-poor. In this study, based on the French national food consumption survey, the diet costs were estimated using retail food prices in France. Adult participants were stratified by quartiles of energy cost (in euro/10 MJ). Dietary energy density, energy and nutrient intakes were then compared across groups. Participants in the lowest quartile of energy cost had the highest energy intakes, the most energy-dense diets and the lowest daily intakes of key vitamins and micronutrients. Participants in the highest quartile of energy cost had lower energy intakes, and diets that were higher in nutrients and lower in energy density. However, their daily diet costs were 165% higher. In this observational study, the more nutrient-dense diets were associated with higher diet costs.

Effect of external stress on the Fe-Cr phase separation in 15-5 PH and Fe-15Cr-5Ni alloys.

The effect on Fe-Cr phase separation of a uniaxial stress during thermal ageing at 425 °C is investigated on a Fe-15Cr-5Ni steel, a model alloy of commercial 15-5 PH steel. The applied stress is shown to accelerate the ageing kinetics, and influence the morphology of Cr rich domains. A dependence of the phase separation decomposition kinetics on the relative orientations of the load and the crystal local orientation has also been observed.

Engineering of the pyruvate dehydrogenase bypass in Saccharomyces cerevisiae: role of the cytosolic Mg(2+) and mitochondrial K(+) acetaldehyde dehydrogenases Ald6p and Ald4p in acetate formation during alcoholic fermentation.

Acetic acid plays a crucial role in the organoleptic balance of many fermented products. We have investigated the factors controlling the production of acetate by Saccharomyces cerevisiae during alcoholic fermentation by metabolic engineering of the enzymatic steps involved in its formation and its utilization. The impact of reduced pyruvate decarboxylase (PDC), limited acetaldehyde dehydrogenase (ACDH), or increased acetoacetyl coenzyme A synthetase (ACS) levels in a strain derived from a wine yeast strain was studied during alcoholic fermentation. In the strain with the PDC1 gene deleted exhibiting 25% of the PDC activity of the wild type, no significant differences were observed in the acetate yield or in the amounts of secondary metabolites formed. A strain overexpressing ACS2 and displaying a four- to sevenfold increase in ACS activity did not produce reduced acetate levels. In contrast, strains with one or two disrupted copies of ALD6, encoding the cytosolic Mg(2+)-activated NADP-dependent ACDH and exhibiting 60 and 30% of wild-type ACDH activity, showed a substantial decrease in acetate yield (the acetate production was 75 and 40% of wild-type production, respectively). This decrease was associated with a rerouting of carbon flux towards the formation of glycerol, succinate, and butanediol. The deletion of ALD4, encoding the mitochondrial K(+)-activated NAD(P)-linked ACDH, had no effect on the amount of acetate formed. In contrast, a strain lacking both Ald6p and Ald4p exhibited a long delay in growth and acetate production, suggesting that Ald4p can partially replace the Ald6p isoform. Moreover, the ald6 ald4 double mutant was still able to ferment large amounts of sugar and to produce acetate, suggesting the contribution of another member(s) of the ALD family.