Vitamin D status of schoolchildren in Northern Algeria, seasonal variations and determinants of vitamin D deficiency

Summary There are no published data on the vitamin D status of children living in North Africa. In 435 healthy Algerian children 5–15 years old, we found that vitamin D insufficiency (serum 25-hydroxyvitamin D (25OHD) <50 nmol/L) was frequent, especially in winter. Low vitamin D status was associated with increased parathyroid hormone (PTH) and leg deformation Introduction As there are no published data on the vitamin D status of children living in North Africa, we evaluated the 25OHD concentration of healthy Algerian children at the end of summer and at the end of winter. As secondary objectives, we studied the various determinants of vitamin D status and the PTH-25OHD relationship in these subjects. Methods Four hundred thirty-five children 5–15 years old were examined and had a blood sample in September 2010. Of them, 408 were sampled again in March 2011. Results Median 25OHD concentration in the whole group was 71.4 nmol/L in September and 52.9 nmol/L in March. In September, 58.4, 29.9, and 8.1 % had a 25OHD concentration below 75, 50, and 30 nmol/L respectively. In March, these percentages increased to 65.2, 41.4, and 17.4 % for the 75, 50, and 30 nmol/L threshold, respectively. In multivariate analysis, older age, darker skin phototype, low daily vitamin D and calcium intake, poor socioeconomic status, and short daily sun exposure remained significantly associated with a 25OHD <50 nmol/L at both visits. In 72 (16.6 %) children, genu varum/valgum was present. Compared to the 363 children without leg deformation, they presented more frequently with the risk factors of vitamin D insufficiency. They also had lower 25OHD concentrations and higher PTH and tALP. Serum PTH and 25OHD concentrations were negatively and significantly correlated (r=−0.43; p<0.001) without a 25OHD threshold above which PTH does not decrease anymore. Conclusion Despite a sunny environment, vitamin D insufficiency is frequent in healthy Algerian children

Assessing the impact of genetically modified plants on the environment using NGS; a case study on transgenic grapevine rootstocks expressing viral coat protein and bacterial nptII transgenes

International audienc

Impact assessment of transgenic grapevine rootstocks expressing viral coat protein and bacterial <em>nptIIgenes</em>, on viral populations and on the soil microflora, using new generation sequencing

National audienc

Nanobody-mediated resistance to grapevine fanleaf virus in plants

Since their discovery, single-domain antigen-binding fragments of camelid-derived heavy-chain-only antibodies, also known as nanobodies (Nbs), have proven to be of outstanding interest as therapeutics against human diseases and pathogens including viruses, but their use against phytopathogens remains limited. Many plant viruses including Grapevine fanleaf virus (GFLV), a nematode-transmitted icosahedral virus and causal agent of fanleaf degenerative disease, have worldwide distribution and huge burden on crop yields representing billions of US dollars of losses annually, yet solutions to combat these viruses are often limited or inefficient. Here, we identified a Nb specific to GFLV that confers strong resistance to GFLV upon stable expression in the model plant Nicotiana benthamiana and also in grapevine rootstock, the natural host of the virus. We showed that resistance was effective against a broad range of GFLV isolates independently of the inoculation method including upon nematode transmission but not against its close relative, Arabis mosaic virus. We also demonstrated that virus neutralization occurs at an early step of the virus life cycle, prior to cell-to-cell movement. Our findings will not only be instrumental to confer resistance to GFLV in grapevine, but more generally they pave the way for the generation of novel antiviral strategies in plants based on Nbs