Characterization of influenza A viruses with polymorphism in PB2 residues 701 and 702

The 701 and 702 positions of influenza PB2 polymerase subunit are previously shown to have roles on host range. Limited polymorphisms at these two residues are identified in natural isolates, thereby limiting the study of their role in the polymerase. In this study, we generated 31 viable viruses by random mutagenesis at this region, indicating that these positions can tolerate a wide range of amino acids. These mutants demonstrated varying polymerase activities and viral replication rates in mammalian and avian cells. Notably, some mutants displayed enhanced polymerase activity, yet their replication kinetics were comparable to the wild-type virus. Surface electrostatic charge predication on the PB2 structural model revealed that the viral polymerase activity in mammalian cells generally increases as this region becomes more positively charged. One of the mutants (701A/702E) showed much reduced pathogenicity in mice while others had a pathogenicity similar to the wild-type level. Distinct tissue tropisms of the PB2-701/702 mutants were observed in infected chicken embryos. Overall, this study demonstrates that the PB2-701/702 region has a high degree of sequence plasticity and sequence changes in this region can alter virus phenotypes in vitro and in vivo.published_or_final_versio

Why did soft drink consumption decrease but screen time not? Mediating mechanisms in a school-based obesity prevention program

<p>Abstract</p> <p>Objectives</p> <p>This paper aims to identify the mediating mechanisms of a school-based obesity prevention program (DOiT).</p> <p>Methods</p> <p>The DOiT-program was implemented in Dutch prevocational secondary schools and evaluated using a controlled, cluster-randomised trial (September 2003 to May 2004). We examined mediators of effects regarding (1) consumption of sugar containing beverages (SCB); (2) consumption of high caloric snacks; (3) screen-viewing behaviour; and (4) active commuting to school. To improve these behaviours the DOiT-program tried to influence the following potentially mediating variables: attitude, subjective norm, perceived behavioural control, and habit-strength.</p> <p>Results</p> <p>Both in boys (n = 418) and girls (n = 436) the DOiT-intervention reduced SCB consumption (between group difference in boys = -303.5 ml/day, 95% CI: -502.4;-104.5, between group difference in girls = -222.3 ml/day, 95% CI: -371.3;-73.2). The intervention did not affect the other examined behaviours. In girls, no intervention effect on hypothetical mediators was found nor evidence of any mediating mechanisms. Boys in intervention schools improved their attitude towards decreasing SCB consumption, while this behaviour became less of a habit. Indeed, attitude and habit strength were significant mediators of the DOiT-intervention's effect (4.5 and 3.8%, respectively) on SCB consumption among boys.</p> <p>Conclusion</p> <p>Our findings imply that interventions aimed at EBRB-change should be gender-specific. Future studies aimed at reducing SCB consumption among boys should target attitude and habit strength as mediating mechanisms. Our study did not resolve the mediating mechanisms in girls.</p> <p>Trial registration</p> <p>International Standard Randomised Controlled Trial Number Register ISRCTN87127361</p

Promoting physical activity using an activity monitor and a tailored web-based advice: design of a randomized controlled trial [ISRCTN93896459]

BACKGROUND: Ageing is associated with a decrease in physical activity. This decrease particularly occurs during specific transitional life stages. Especially during adolescence and young adulthood a steep decrease in physical activity is observed. Inactive people are often not aware of their inactivity. Providing feedback on the actual physical activity level by an activity monitor can increase awareness and may in combination with an individually tailored physical activity advice stimulate a physically active lifestyle. METHODS: In a randomized controlled trial the effectiveness of providing an activity monitor in combination with a personal physical activity advice through the Internet will be examined. Outcome measures are level of physical activity, determinants of physical activity, quality of life, empowerment, aerobic fitness and body composition. Participants are relatively inactive adolescents and young adults who are measured at baseline, after 3 months intervention and 5 months after the end of the intervention. In addition, facilitating and hindering factors for implementation of the intervention will be investigated. DISCUSSION: The use of a personal activity monitor in combination with web-based assisted individually tailored health promotion offers a good opportunity to work interactively with large groups of adolescents and young adults and provide them with advice based on their actual activity level. It has great potential to motivate people to change their behaviour and to our knowledge has not been evaluated before

Effects of resistance and all-round, functional training on quality of life, vitality and depression of older adults living in long-term care facilities: a 'randomized' controlled trial [ISRCTN87177281]

BACKGROUND: Regular physical activity may improve different aspects of wellbeing in older people, such as quality of life, vitality and depression. However, there is little experimental evidence to support this assumption. Therefore, we examined the effect of different training protocols on quality of life, vitality and depression of older adults living in long-term care facilities. METHODS: Subjects (n = 173, aged 64 to 94 years, living in long-term care facilities), were randomized to six months of three different moderate-intensity group exercise training protocols, or to an 'educational' control condition. Exercise consisted of two 45–60-minute training sessions per week of 1) resistance training; 2) all-round, functional training; or 3) a combination of both. Perceived health, the Geriatric Depression Scale (GDS), the Vitality Plus Scale (VPS) and the Dementia Quality of Life questionnaire (DQoL) were administered at baseline and after six months. RESULTS: In the combined training group a small but significant decline was seen in perceived health, DQoL and VPS score compared to the control group. CONCLUSIONS: We conclude that neither strength training nor all-round, functional training of moderate intensity is effective in improving quality of life, vitality or depression of older people living in long-term care facilities

Evaluation and Management of Anal Intraepithelial Neoplasia in HIV-Negative and HIV-Positive Men Who Have Sex with Men

The incidence of human papillomavirus (HPV)–associated anal cancer in men who have sex with men (MSM) is striking and has not been mitigated by the use of highly active antiretroviral therapy. Detection and treatment of high-grade anal intraepithelial neoplasia (HGAIN) may reduce the incidence of anal cancer. Anal cytology is a useful tool to detect HGAIN; annual screening of HIV-positive MSM and biennial screening of HIV-negative MSM appears to be cost-effective. MSM with abnormal cytology should be referred for high-resolution anoscopy and biopsy. Individuals with HGAIN should receive treatment; treatment modalities for HGAIN demonstrate moderate efficacy and are usually well tolerated, but greater study is required to determine which treatment is optimal. Large prospective studies are needed to document the efficacy of screening and treatment of HGAIN on anal cancer incidence. The HPV vaccine holds promise for primary prevention of anal cancer in MSM, but significant implementation challenges remain

Anal HPV Infection in HIV-Positive Men Who Have Sex with Men from China

BACKGROUND: Anal HPV infection, which contributes to the development of anal warts and anal cancer, is well known to be common among men who have sex with men (MSM), especially among those HIV positives. However, HIV and anal HPV co-infection among MSM has not been addressed in China. METHODS: A cross-sectional study was conducted in Beijing and Tianjin, China. Study participants were recruited using multiple methods with the collaboration of local volunteer organizations. Blood and anal swabs were collected for HIV-1 serological test and HPV genotyping. RESULTS: A total of 602 MSM were recruited and laboratory data were available for 578 of them (96.0%). HIV and anal HPV prevalence were 8.5% and 62.1%, respectively. And 48 MSM (8.3%) were found to be co-infected. The HPV genotypes identified most frequently were HPV06 (19.6%), HPV16 (13.0%), HPV52 (8.5%) and HPV11 (7.6%). Different modes of HPV genotypes distribution were observed with respect to HIV status. A strong dose-response relationship was found between HIV seropositivity and multiplicity of HPV genotypes (p<0.001), which is consistent with the observation that anal HPV infection was an independent predictor for HIV infection. CONCLUSIONS: A high prevalence of HIV and anal HPV co-infection was observed in the MSM community in Beijing and Tianjin, China. Anal HPV infection was found to be independently associated with increased HIV seropositivity, which suggests the application of HPV vaccine might be a potential strategy to reduce the acquisition of HIV infection though controlling the prevalence of HPV

Effects of resistance and functional-skills training on habitual activity and constipation among older adults living in long-term care facilities: a randomized controlled trial

BACKGROUND: Large-scale RCTs comparing different types of exercise training in institutionalised older people are scarce, especially regarding effects on habitual physical activity and constipation. This study investigated the effects of different training protocols on habitual physical activity and constipation of older adults living in long-term care facilities. METHODS: A randomized controlled trial with 157 participants, aged 64 to 94 years, who were randomly assigned to 1) resistance training; 2) all-round functional-skills training; 3) both; or 4) an 'educational' control condition. Habitual physical activity was assessed with a physical activity questionnaire and accelerometers. Constipation was assessed by a questionnaire. Measurements were performed at baseline and after six months of training. RESULTS: At baseline the median time spent sitting was 8.2 hr/d, the median time spent on activity of at least moderate intensity was 32 min/d. At baseline, about 22% of the subjects were diagnosed with constipation and 23% were taking laxatives. There were no between-group differences for changes in habitual physical activity or constipation over 6-months. CONCLUSION: Six months of moderate intensity exercise training neither enhances habitual physical activity nor affects complaints of constipation among older people living in long-term care facilities

Cross-sectional relationship between physical fitness components and functional performance in older persons living in long-term care facilities

BACKGROUND: The age-related deterioration of physiological capacities such as muscle strength and balance is associated with increased dependence. Understanding the contribution of physical fitness components to functional performance facilitates the development of adequate exercise interventions aiming at preservation of function and independence of older people. The aim of the study was to investigate the relationship between physical fitness components and functional performance in older people living in long-term care facilities. METHODS: Design cross-sectional study Subjects 226 persons living in long-term care facilities (mean age: 81.6 ± 5.6). Outcome measures Physical fitness and functional performance were measured by performance-based tests. RESULTS: Knee and elbow extension strength were significantly higher in men (difference = 44.5 and 50.0 N, respectively), whereas women were more flexible (difference sit & reach test = 7.2 cm). Functional performance was not significantly different between the genders. In men, motor coordination (eye-hand coordination) and measures of strength were the main contributors to functional performance, whereas in women flexibility (sit and reach test) and motor coordination (tandem stance and eye-hand coordination) played a major role. CONCLUSION: The results of this study show that besides muscle strength, fitness components such as coordination and flexibility are associated with functional performance of older people living in long-term care facilities. This suggests that men and women living in long-term care facilities, differ considerably concerning the fitness factors contributing to functional performance. Women and men may, therefore, need exercise programs emphasizing different fitness aspects in order to improve functional performance

Impact of Provider Self-Management Education, Patient Self-Efficacy, and Health Status on Patient Adherence in Heart Failure in a Veterans Administration Population

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73786/1/j.1751-7133.2008.07174.x.pd