The effects of healthy aging on intracerebral blood vessels visualized by magnetic resonance angiography

Histological and magnetic resonance imaging studies have demonstrated that age-associated alterations of the human brain may be at least partially related to vascular alterations. Relatively little information has been published on vascular changes associated with healthy aging, however. The study presented in this paper examined vessels segmented from standardized, high-resolution, magnetic resonance angiograms (MRA) of 100 healthy volunteers (50 males, 50 females), aged 18-74, without hypertension or other disease likely to affect the vasculature. The subject sample was divided into 5 age groups (n=20/group) with gender equally distributed per group. The anterior cerebral, both middle cerebral, and the posterior circulations were examined for vessel number, vessel radius, and vessel tortuosity. Males exhibited larger vessel radii regardless of age and across all anatomical regions. Both males and females displayed a lower number of MRA-discernible vessels with age, most marked in the posterior circulation. Age-associated tortuosity increases were relatively mild. Our multi-modal image database has been made publicly available for use by other investigators

Influence of Novel Norovirus GII.4 Variants on Gastroenteritis Outbreak Dynamics in Alberta and the Northern Territories, Canada between 2000 and 2008

BACKGROUND: Norovirus GII.4 is the predominant genotype circulating worldwide over the last decade causing 80% of all norovirus outbreaks with new GII.4 variants reported in parallel with periodic epidemic waves of norovirus outbreaks. The circulating new GII.4 variants and the epidemiology of norovirus outbreaks in Alberta, Canada have not been described. Our hypothesis is that the periodic epidemic norovirus outbreak activity in Alberta was driven by new GII.4 variants evolving by genetic drift. METHODOLOGY/PRINCIPAL FINDINGS: The Alberta Provincial Public Health Laboratory performed norovirus testing using RT-PCR for suspected norovirus outbreaks in the province and the northern Territories between 2000 and 2008. At least one norovirus strain from 707 out of 1,057 (66.9%) confirmed norovirus outbreaks were successfully sequenced. Phylogenetic analysis was performed using BioNumerics and 617 (91.1%) outbreaks were characterized as caused by GII.4 with 598 assigned as novel variants including: GII.4-1996, GII.4-2002, GII.4-2004, GII.4-2006a, GII.4-2006b, GII.4-2008a and GII.4-2008b. Defining July to June of the following year as the yearly observation period, there was clear biannual pattern of low and high outbreak activity in Alberta. Within this biannual pattern, high outbreak activity followed the emergence of novel GII.4 variants. The two variants that emerged in 2006 had wider geographic distribution and resulted in higher outbreak activity compared to other variants. The outbreak settings were analyzed. Community-based group residence was the most common for both GII.4 variants and non-GII.4 variants. GII.4 variants were more commonly associated with outbreaks in acute care hospitals while outbreaks associated non-GII.4 variants were more commonly seen in school and community social events settings (p<0.01). CONCLUSIONS/SIGNIFICANCE: The emergence of new norovirus GII.4 variants resulted in an increased norovirus outbreak activity in the following season in a unique biannual pattern in Alberta over an eight year period. The association between antigenic drift of GII.4 strains and epidemic norovirus outbreak activity could be due to changes in host immunity, viral receptor binding efficiency or virulence factors in the new variants. Early detection of novel GII.4 variants provides vital information that could be used to forecast the norovirus outbreak burden, enhance public health preparedness and allocate appropriate resources for outbreak management

Health benefits of tennis

The aim of the study was to explore the role of tennis in the promotion of health and prevention of disease. The focus was on risk factors and diseases related to a sedentary lifestyle, including low fitness levels, obesity, hyperlipidaemia, hypertension, diabetes mellitus, cardiovascular disease, and osteoporosis. A literature search was undertaken to retrieve relevant articles. Structured computer searches of PubMed, Embase, and CINAHL were undertaken, along with hand searching of key journals and reference lists to locate relevant studies published up to March 2007. These had to be cohort studies (of either cross sectional or longitudinal design), case–control studies, or experimental studies. Twenty four studies were identified that dealt with physical fitness of tennis players, including 17 on intensity of play and 16 on maximum oxygen uptake; 17 investigated the relation between tennis and (risk factors for) cardiovascular disease; and 22 examined the effect of tennis on bone health. People who choose to play tennis appear to have significant health benefits, including improved aerobic fitness, a lower body fat percentage, a more favourable lipid profile, reduced risk for developing cardiovascular disease, and improved bone health

Safety (toxicity), pharmacokinetics, immunogenicity, and impact on elements of the normal immune system of recombinant human IL-15 in rhesus macaques

IL-15 uses the heterotrimeric receptor IL-2/IL-15Rβ and the γ chain shared with IL-2 and the cytokine-specific IL-15Rα. Although IL-15 shares actions with IL-2 that include activation of natural killer (NK) and CD8 T cells, IL-15 is not associated with capillary leak syndrome, activation-induced cell death, or with a major effect on the number of functional regulatory T cells. To prepare for human trials to determine whether IL-15 is superior to IL-2 in cancer therapy, recombinant human IL-15 (rhIL-15) was produced under current good manufacturing practices. A safety study in rhesus macaques was performed in 4 groups of 6 animals each that received vehicle diluent control or rhIL-15 at 10, 20, or 50 μg/kg/d IV for 12 days. The major toxicity was grade 3/4 transient neutropenia. Bone marrow examinations demonstrated increased marrow cellularity, including cells of the neutrophil series. Furthermore, neutrophils were observed in sinusoids of enlarged livers and spleens, suggesting that IL-15 mediated neutrophil redistribution from the circulation to tissues. The observation that IL-15 administration was associated with increased numbers of circulating NK and CD8 central and effector-memory T cells, in conjunction with efficacy studies in murine tumor models, supports the use of multiple daily infusions of rhIL-15 in patients with metastatic malignancies