Genomic characterization of human rotavirus G8 strains from the African rotavirus network: Relationship to animal rotaviruses

Global rotavirus surveillance has led to the detection of many unusual human rotavirus (HRV) genotypes. During 1996–2004 surveillance within the African Rotavirus Network (ARN), six P[8],G8 and two P[6],G8 human rotavirus strains were identified. Gene fragments (RT‐PCR amplicons) of all 11‐gene segments of these G8 strains were sequenced in order to elucidate their genetic and evolutionary relationships. Phylogenetic and sequence analyses of each gene segment revealed high similarities (88–100% nt and 91–100% aa) for all segments except for gene 4 encoding VP4 proteins P[8] and P[6]. For most strains, almost all of the genes of the ARN strains other than neutralizing antigens are related to typical human strains of Wa genogroup. The VP7, NSP2, and NSP5 genes were closely related to cognate genes of animal strains (83–99% and 97–99% aa identity). This study suggests that the ARN G8 strains might have arisen through VP7 or VP4 gene reassortment events since most of the other gene segments resemble those of common human rotaviruses. However, VP7, NSP2 (likely), and NSP5 (likely) genes are derived potentially from animals consistent with a zoonotic introduction. Although these findings help elucidate rotavirus evolution, sequence studies of cognate animal rotavirus genes are needed to conclusively determine the specific origin of those genes relative to both human and animal rotavirus strains. J. Med. Virol. 81:937–951, 2009. © 2009 Wiley‐Liss, Inc.     

Epidemiology and clinical presentation of respiratory syncytial virus infection in a Tunisian neonatal unit from 2000 to 2002

Respiratory syncytial virus (RSV) is an important viral pathogen causing lower respiratory tract infection (LRI) in infants. This study describes the clinical and genetic epidemiology of RSV infection among Tunisian neonates. Nasopharyngeal aspirates collected from 268 newborns with LRI were screened for RSV by immunofluorescence assay. Positive samples were analysed by RT-PCR-hybridisation assay for subgroup classification of RSV genomes. RSV infection was present in 23.1% of neonates, with a predominance in males. Peak incidence occurred in winter. Subgroup classification showed a higher prevalence of group B than group A strains. Nosocomially acquired RSV infection was present in 37% of neonates, 54.3% had an underlying condition predisposing to severe disease and 13% died. The average duration of hospital stay was 10 days and 87% of newborns required supplemental oxygen. As no currently effective treatment is available, preventive measures are a priority in high-risk infants.     

Endothelial nitric oxide synthase gene polymorphism is associated with Behçet's disease in Tunisian population

Nitric oxide (NO) is a molecule that plays a key role in many physiologic and pathologic processes. It is produced in vivo from the aminoacid l-arginine by a family of nitric oxide synthases (NOS). Endothelial NOS (eNOS) is a constitutively expressed isoform of NOS. The eNOS gene entails several polymorphisms, of which certain were investigated in Beh?et's disease (BD). We sought to establish the association of eNOS gene Glu298Asp polymorphism in exon 7 with susceptibility to BD. In this study, 135 Tunisian patients with BD and 157 healthy blood donor controls from the same geographic area were genotyped by polymerase chain reaction technique for eNOS polymorphism in exon 7. Our results showed that the distribution of the Glu298Asp genotype differed between BD patients and controls but did not reach statistical significance (p = 0.06). Allele Asp298 was significantly more frequent in healthy controls than in BD patients (p = 0.037, chi(2) = 4.33, OR = 1.01, 95% CI = 1.41-1.99). A significant difference was found (p = 0.004, OR = 1.26, 95% CI = 2.13-3.62) between BD patients with skin lesions and patients without this manifestation. Our findings suggest that Glu298Asp polymorphism of eNOS gene is associated with BD susceptibility as well as skin lesions.     

Vitamin D and Obesity/Adiposity—A Brief Overview of Recent Studies

Observational studies classically find an inverse relationship between human plasma 25-hydroxyvitamin D concentration and obesity. However, interventional and genetic studies have failed to provide clear conclusions on the causal effect of vitamin D on obesity/adiposity. Likewise, vitamin D supplementation in obese rodents has mostly failed to improve obesity parameters, whereas several lines of evidence in rodents and prospective studies in humans point to a preventive effect of vitamin D supplementation on the onset of obesity. Recent studies investigating the impact of maternal vitamin D deficiency in women and in rodent models on adipose tissue biology programming in offspring further support a preventive metabolically driven effect of vitamin D sufficiency. The aim of this review is to summarize the state of the knowledge on the relationship between vitamin D and obesity/adiposity in humans and in rodents and the impact of maternal vitamin D deficiency on the metabolic trajectory of the offspring.