Background Disruption of 11p15 imprinting results in two fetal growth disorders with opposite phenotypes: the Beckwith–Wiedemann (BWS; MIM 130650) and the Silver–Russell (SRS; MIM 180860) syndromes. DNA methylation defects account for 60% of BWS and SRS cases and, in most cases, occur without any identified mutation in a cis-acting regulatory sequence or a trans-acting factor. Methods We investigated whether 11p15 cis-acting sequence variants account for primary DNA methylation defects in patients with SRS and BWS with loss of DNA methylation at ICR1 and ICR2, respectively. Results We identified a 4.5 kb haplotype that, upon maternal transmission, is associated with a risk of ICR2 loss of DNA methylation in patients with BWS. This novel region is located within the second intron of the KCNQ1 gene, 170 kb upstream of the ICR2 imprinting centre and encompasses two CTCF binding sites. We showed that, within the 4.5 kb region, two SNPs (rs11823023 and rs179436) affect CTCF occupancy at DNA motifs flanking the CTCF 20 bp core motif. Conclusions This study shows that genetic variants confer a risk of DNA methylation defect with a parent-of-origin effect and highlights the crucial role of CTCF for the regulation of genomic imprinting of the CDKN1C/KCNQ1 domain. arabic 26 English 132
Julie Demars, Mansur Ennuri Moftah Shmela, Abdul Waheed Khan , Kai Syin Lee, Salah Azzi, Patrice Dehais, Irène Netchine, Sylvie Rossignol, Yves Le Bouc, Assam El-Osta, Christine Gicquel(7-2014)

A serological survey was carried out in Libya to investigate the circulation of Rift Valley fever virus (RVFV) among domestic ruminants. A total of 857 serum samples were collected from year 2015 to 2016 in eleven provinces of Libya belonging to five branches of the country. Samples were tested for RVFV antibodies using a competitive EnzymeLinked Immunosorbent Assay (c-ELISA). Antibodies specific for RVFV were not detected in any of the 857 samples. However, a statistical analysis was carried out to assess the maximum expected number of infected animals and the maximum expected prevalence of RVFV among Libyan ruminants’ populations according to the sampled population. The overall maximum expected prevalence was estimated to be 1.8% for cattle and 0.4% for small ruminants. Results seem to exclude the circulation of RVFV, however, a surveillance plan should be implemented in areas at risk of RVFV introduction. arabic 10 English 55
Abdusalam Sharef Abdusalam Mahmoud, (6-2018)

In order to study microscopic and macroscopic lesions in chickens infected with low and high doses of Salmonella enteritidis PT 4 (SE), 150 one-day-old White Plymouth Rock chicks were divided into three groups each containing 50 birds. The chickens of the first and second groups were inoculated with 2 x 102 and 2 x 108 cfu of Salmonella, respectively. The chicks of the third group were kept as uninoculated control birds. Five birds from each group were euthanized by cervical dislocation at 6, 12, 18 hours post inoculation (hpi) and then after 1, 3, 7, 10, 14, 21, and 27 days post inoculation (dpi) and were examined for presence of gross and histological lesions. Catarrhal typhlitis and unabsorbed yolk sac were the most prevalent gross lesions in both groups. Histologically, granulomatous nodules in the caecum were found occasionally in some cases in both inoculated groups. The present study demonstrated that the chickens infected with a low dose of SE showed fewer lesions, which were milder in comparison with the birds inoculated with a high dose of SE. It suggests that chickens were able to capture the pathogen in the low dose group
Abdulatif Asheg(1-2001)