Virulence in Murine Model Shows the Existence of Two Distinct Populations of Brazilian Vaccinia virus Strains

Brazilian Vaccinia virus had been isolated from sentinel mice, rodents and recently from humans, cows and calves during outbreaks on dairy farms in several rural areas in Brazil, leading to high economic and social impact. Some phylogenetic studies have demonstrated the existence of two different populations of Brazilian Vaccinia virus strains circulating in nature, but little is known about their biological characteristics. Therefore, our goal was to study the virulence pattern of seven Brazilian Vaccinia virus strains. Infected BALB/c mice were monitored for morbidity, mortality and viral replication in organs as trachea, lungs, heart, kidneys, liver, brain and spleen. Based on the virulence potential, the Brazilian Vaccinia virus strains were grouped into two groups. One group contained GP1V, VBH, SAV and BAV which caused disease and death in infected mice and the second one included ARAV, GP2V and PSTV which did not cause any clinical signals or death in infected BALB/c mice. The subdivision of Brazilian Vaccinia virus strains into two groups is in agreement with previous genetic studies. Those data reinforce the existence of different populations circulating in Brazil regarding the genetic and virulence characteristics

Bone Mineral Content and Density in Rett Syndrome and TheirContributing Factors

This study used densitometry to investigate the areal bone mineral density (aBMD) and bone mineral content (BMC) in an Australian Rett syndrome cohort and assess how factors such as genotype, epilepsy, BMI and mobility affect these parameters. The influence of lean tissue mass (LTM) and bone area (BA) on total body BMC (TBBMC) was also investigated. Participants, recruited from the Australian Rett Syndrome Database (ARSD), had TBBMC and lumbar spine (LS) and femoral neck (FN) aBMD measured using Dual energy X-ray absorptiometry. Mean height standardised z-scores and confidence intervals for the bone outcomes were obtained from multiple regression models. The mean height z-score for the FN aBMD was low at −2.20, while the LS aBMD was −0.72. The TBBMC mean height z-score was −0.62, although once adjusted for BA and LTM the mean was above zero, suggesting that low BMC can be explained by narrow bones and decreased muscle mass, likely secondary to decreased mobility. Multiple linear regression identified the p.R168X and p.T158M mutations as the strongest predictors of low aBMC and BMD for all bone outcomes. The strong relation between genotype, BMC and aBMD, is likely underpinned by the strong relation between LTM, mobility and bone outcome measures