Citations

ABSTRACT Since some strains of Brucella species may require carbon dioxide for growth, a multilaboratory study was conducted to compare broth microdilution susceptibility results using ambient air (AA) and 5% CO 2 incubation conditions. Six antimicrobial agents were tested against 39 Brucella isolates. Aminoglycoside MICs tended to be 1 log 2 dilution higher in CO 2 than in AA; tetracycline-class MICs to be 1 log 2 dilution lower in CO 2 .

Although attention-dividing dual tasks hinder gait performance in older persons, gender differences in gait have not been examined. The purpose of this study was to examine whether gait performance differs between older men and women during dual task walking. A total of 44 healthy adults (20 men and 24 women) aged 65 years or older participated in the study. Participants walked under normal and dual task (backward spelling) conditions at self-selected speeds. Mean gait speed and stride-to-stride variability in gait speed were quantified with GAITRite ® instrumentation. Whereas gait speed decreased and variability in gait speed increased in both groups during dual task walking, men walked with greater variability during dual task walking than did women. The magnitude of the increase in variability in gait speed observed in men indicates that stride-to-stride variability in gait speed during dual task walking requires more investigation as a potential risk factor for falls in older men.

The potential for endogenous remyelination and axonal protection can be an important factor in determining disease outcome in demyelinating diseases like multiple sclerosis. In many multiple sclerosis (MS) patients CNS repair fails or is incomplete whereas in others the disease is accompanied by extensive repair of demyelinated lesions. We have described significant differences in the ability of two strains of mice to repair CNS damage following Theiler’s virus-induced demyelination: FVB/NJ (FVB) mice repair damaged myelin spontaneously and completely, whereas B10.D1-H2 q /SgJ (B10.Q) mice are deficient in the repair process. A QTL analysis was performed to identify genetic loci that differentially regulate CNS repair following chronic demyelination in these strains and two QTL were detected: one on chromosome 3 with a LOD score of 9.3 and a second on chromosome 9 with a LOD score of 14.0. The mouse genes for epidermal growth factor (EGF) and Tyk2 are encoded within the QTL on chromosomes 3 and 9, respectively. Sequence polymorphisms between the FVB and B10.Q strains at both the EGF and Tyk2 loci define functional variations consistent with roles for these genes in regulating myelin repair. EGF is a key regulator of cell growth and development and we show a sevenfold increase in EGF expression in FVB compared to B10.Q mice. Tyk2 is a Janus kinase that plays a central role in controlling the T H 1 immune response and we show that attenuation of Tyk2 function correlates with enhanced CNS repair.