Apoptosis has been suggested as a mechanism by which dengue (DEN) virus infection may cause neuronal cell death (P. Desprès, M. Flamand, P.-E. Ceccaldi, and V. Deubel, J. Virol. 70:4090–4096, 1996). In this study, we investigated whether apoptotic cell death occurred in the central nervous system (CNS) of neonatal mice inoculated intracerebrally with DEN virus. We showed that serial passage of a wild-type human isolate of DEN virus in mouse brains selected highly neurovirulent variants which replicated more efficiently in the CNS. Infection of newborn mice with these neurovirulent variants produced fatal encephalitis within 10 days after inoculation. Virus-induced cell death and oligonucleosomal DNA fragmentation were observed in mouse brain tissue by day 9. Infected mouse brain tissue was assayed for apoptosis by in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and for virus replication by immunostaining of viral antigens and in situ hybridization. Apoptotic cell death and DEN virus replication were restricted to the neurons of the cortical and hippocampal regions. Thus, DEN virus-induced apoptosis in the CNS was a direct result of virus infection. In the murine neuronal cell line Neuro 2a, neuroadapted DEN virus variants showed infection patterns similar to those of the parental strain. However, DEN virus-induced apoptosis in these cells was more pronounced after infection with the neurovirulent variants than after infection with the parental strain.

We assessed body composition and muscle strength during the transition phase in 18 growth hormone (GH) deficient males treated with recombinant GH to final height and 18 controls. According to peak-stimulated GH and basal insulin-like growth factor-1 (IGF-1) during the transition phase, patients were subdivided into GH deficient (GHD-TP, n=9) and GH sufficient (GHS-TP, n=9) groups. Assessments included lean and fat body mass and bone mineral density (BMD), all measured by dual-energy X-ray absorptiometry, and dynamic knee muscle strength, assessed by isokinetic dynamometer. Total body and lumbar spine BMD and muscle strength were lower in GHD-TP patients when compared with GHS-TP and controls (all p<0.05), whereas lean and fat body mass were lower in both GHD-TP and GHS-TP patients when compared with controls (p<0.05). These findings suggest that administration of recombinant GH to final height is not sufficient to provide normal body composition and muscle strength in young male patients with GH deficiency.

Background During the transition phase (TP), patients with growth hormone deficiency (GHD) exhibit decreased muscle strength. Studies assessing the effects of resistance exercise alone on muscle strength in these individuals are scarce. The objective of this study was to evaluate the effects of a program of resistance exercise (PRE) on parameters of muscle strength in subjects in the TP and with childhood-onset GHD treated with recombinant GH (rGH). Methods Sixteen male patients were enrolled and divided into two groups: GHD (n=9) and GH sufficiency (GHS, n=7). Patients with GHD underwent a 12-week PRE followed by another 12-week PRE plus rGH, while GHS patients underwent a 12-week PRE alone. Dynamic knee muscle strength was evaluated using an isokinetic dynamometer. Results Before PRE, there were significant differences between the groups regarding the results of flexor peak torque (FPT) normalized to body weight (BW-FPT) in the dominant (DO, p=0.008) and non-dominant (ND, p=0.01) limbs, and in the agonist/antagonist (A/A) ratio in the DO (p=0.02) and ND (p=0.006) limbs. After PRE in the GHD group, values of FPT and BW-FPT in both limbs increased significantly (p<0.001) and independently of rGH, while the A/A ratio value improved significantly (p<0.001) in the ND limb. Conclusions A short period of PRE alone was sufficient to improve parameters of muscle strength in young male adults with childhood-onset GHD.

No abstract

No abstract