Relationship of cardiorespiratory fitness with screen time and physical activity in adolescents.

OBJECTIVE: To determine the correlation of cardiorespiratory fitness with screen time and physical activity in healthy adolescents. METHODS: The analytical cross-sectional study was conducted at the Foundation University, Islamabad, Pakistan, from February to July 2019, and comprised healthy adolescents aged 11-17 years of both genders who were enrolled from various schools of Rawalpindi and Islamabad. Cardiorespiratory fitness was evaluated through YMCA 3 min Step test, physical activity levels were evaluated using physical activity questionnaire for adolescents, and screen time was evaluated using Healthy Lifestyle in Europe by Nutrition in Adolescence screen time questionnaire. Data was analysed using SPSS 21. RESULTS: Of the 250 adolescents, 128(51.2%) were males and 122(48.8%) were females. The overall mean age was 14.24±2.177 years (range: 11-17 years). There was no significant correlation between cardiorespiratory fitness and physical activity (p=0.15), and between cardiorespiratory fitness and screen time (p=0.58). CONCLUSIONS: There was found to be no significant correlation between cardiorespiratory fitness and physical activity, and between cardiorespiratory fitness and screen time in healthy adolescents.

Intranasal administration of a two-dose adjuvanted multi-antigen TMV-subunit conjugate vaccine fully protects mice against Francisella tularensis LVS challenge.

Tularemia is a fatal human disease caused by Francisella tularensis, a Gram-negative encapsulated coccobacillus bacterium. Due to its low infectious dose, ease of aerosolized transmission, and lethal effects, the CDC lists F. tularensis as a Category A pathogen, the highest level for a potential biothreat agent. Previous vaccine studies have been conducted with live attenuated, inactivated, and subunit vaccines, which have achieved partial or full protection from F. tularensis live vaccine strain (LVS) challenge, but no vaccine has been approved for human use. We demonstrate the improved efficacy of a multi-antigen subunit vaccine by using Tobacco Mosaic virus (TMV) as an antigen carrier for the F. tularensis SchuS4 proteins DnaK, OmpA, SucB and Tul4 (DOST). The magnitude and quality of immune responses were compared after mice were immunized by subcutaneous or intranasal routes of administration with a TMV-DOST mixture, with or without four different adjuvants. Immune responses varied in magnitude and isotype profile, by antigen, by route of administration, and by protection in an F. tularensis LVS challenge model of disease. Interestingly, our analysis demonstrates an overwhelming IgG2 response to SucB after intranasal dosing, as well as a robust cellular response, which may account for the improved two-dose survival imparted by the tetravalent vaccine, compared to a previous study that tested efficacy of TMV-DOT. Our study provides evidence that potent humoral, cellular and mucosal immunity can be achieved by optimal antigen combination, delivery, adjuvant and appropriate route of administration, to improve vaccine potency and provide protection from pathogen challenge.