Viral dynamics of acute HIV-1 infection.

Viral dynamics were intensively investigated in eight patients with acute HIV infection to define the earliest rates of change in plasma HIV RNA before and after the start of antiretroviral therapy. We report the first estimates of the basic reproductive number (R(0)), the number of cells infected by the progeny of an infected cell during its lifetime when target cells are not depleted. The mean initial viral doubling time was 10 h, and the peak of viremia occurred 21 d after reported HIV exposure. The spontaneous rate of decline (alpha) was highly variable among individuals. The phase 1 viral decay rate (delta(I) = 0.3/day) in subjects initiating potent antiretroviral therapy during acute HIV infection was similar to estimates from treated subjects with chronic HIV infection. The doubling time in two subjects who discontinued antiretroviral therapy was almost five times slower than during acute infection. The mean basic reproductive number (R(0)) of 19.3 during the logarithmic growth phase of primary HIV infection suggested that a vaccine or postexposure prophylaxis of at least 95% efficacy would be needed to extinguish productive viral infection in the absence of drug resistance or viral latency. These measurements provide a basis for comparison of vaccine and other strategies and support the validity of the simian immunodeficiency virus macaque model of acute HIV infection

The measurement of media literacy in eating disorder risk factor research: Psychometric properties of six measures

BACKGROUND: Evaluation of media literacy-based interventions for the prevention of eating disorder risk is limited by the lack of appropriate measures with established psychometric properties with which to assess change in media literacy. This study aims to fill this gap by examining the psychometric properties and use in eating disorders risk factor research of six measures of media literacy that assess media processing and critical thinking about general media and critical thinking about appearance-focused media. METHODS: The factor structure, internal consistency, test-retest reliability, and construct validity, including convergent and discriminant validity, were examined in six measures in two samples of early adolescent females. The measures were the Realism Scepticism, Similarity Scepticism, and Desirability Scepticism subscales of the Media Attitudes Questionnaire, the Fake subscale of the Critical Processing of Beauty Images Scale, the Critical Thinking about Media Messages scale, and Critical Thinking about Media Messages - Appearance Focus scale. RESULTS: The factor structure of the measures was supported with factor analysis. Items from the Media Attitudes Questionnaire loaded on the three subscales Realism Scepticism, Similarity Scepticism, and Desirability Scepticism and items from each of the Fake subscale, Critical Thinking about Media Messages scale and Critical Thinking about Media Messages - Appearance Focus scale loaded on one scale. In addition, scores on the measures were reliable (adequate internal consistency and test-retest reliability) and valid (adequate construct, convergent, and discriminant validity) in early adolescent females. Two exceptions were Realism Scepticism, which had slightly low test-retest reliability, and the Fake subscale, for which support for construct validity was lacking. CONCLUSIONS: This study provides evidence to support the use of select media literacy measures, particularly the Realism Scepticism subscale and the Critical Thinking about Media Messages scale, in eating disorder risk factor research and the findings will contribute to enhanced evaluation of media literacy-based prevention interventions

Dismantling prevention: Comparison of outcomes following media literacy and appearance comparison modules in a randomised controlled trial.

A dismantling study of body dissatisfaction prevention was conducted. Adolescent girls ( N = 260) were randomly allocated to a media literacy (Happy Being Me – Media Literacy) or appearance comparison (Happy Being Me – Appearance Comparison) intervention or healthy eating behaviour control (Happy Being Me – Healthy Eating Behaviour) condition. In the Happy Being Me – Appearance Comparison condition, improvements from baseline to post-programme and follow-up for upward appearance comparison and fear of negative appearance evaluation were observed. In the Happy Being Me – Media Literacy condition, improvements were observed from baseline to post-programme for upward appearance comparison and realism scepticism. Findings were similar in a high-risk subsample and overall are moderately supportive of appearance comparison-based interventions, but less supportive of a stand-alone media literacy intervention. </jats:p

Neuromuscular, endocrine, and perceptual fatigue responses during different length between-match microcycles in professional rugby league players

The purpose of this study was to examine the changes in neuromuscular, perceptual and hormonal measures following professional rugby league matches during different length between-match microcycles. Methods: Twelve professional rugby league players from the same team were assessed for changes in countermovement jump (CMJ) performance (flight time and relative power), perceptual responses (fatigue, well-being and muscle soreness) and salivary hormone (testosterone [T] and cortisol [C]) levels during 5, 7 and 9 d between-match training microcycles. All training was prescribed by the club coaches and was monitored using the session-RPE method. Results: Lower mean daily training load was completed on the 5 d compared with the 7 and 9 d microcycles. CMJ flight time and relative power, perception of fatigue, overall well-being and muscle soreness were significantly reduced in the 48 h following the match in each microcycle (P < .05). Most CMJ variables returned to near baseline values following 4 d in each microcycle. Countermovement jump relative power was lower in the 7 d microcycle in comparison with the 9 d microcycle (P < .05). There was increased fatigue at 48 h in the 7 and 9 d microcycles (P < .05) but had returned to baseline in the 5 d microcycle. Salivary T and C did not change in response to the match. Discussion: Neuromuscular performance and perception of fatigue are reduced for at least 48 h following a rugby league match but can be recovered to baseline levels within 4 d. These findings show that with appropriate training, it is possible to recover neuromuscular and perceptual measures within 4 d after a rugby league match. © Human Kinetics, Inc

Identifying persuasive public health messages to change community knowledge and attitudes about bulimia nervosa

Addressing stigma through social marketing campaigns has the potential to enhance currently low rates of treatment seeking and improve the well-being of individuals with the eating disorder bulimia nervosa. This study aimed to evaluate the persuasiveness of health messages designed to reduce stigma and improve mental health literacy about this disorder. A community sample of 1,936 adults (48.2% male, 51.8% female) from Victoria, Australia, provided (a) self-report information on knowledge and stigma about bulimia nervosa and (b) ratings of the persuasiveness of 9 brief health messages on dimensions of convincingness and likelihood of changing attitudes. Messages were rated moderately to very convincing and a little to moderately likely to change attitudes toward bulimia nervosa. The most persuasive messages were those that emphasized that bulimia nervosa is a serious mental illness and is not attributable to personal failings. Higher ratings of convincingness were associated with being female, with having more knowledge about bulimia nervosa, and with lower levels of stigma about bulimia nervosa. Higher ratings for likelihood of changing attitudes were associated with being female and with ratings of the convincingness of the corresponding message. This study provides direction for persuasive content to be included in social marketing campaigns to reduce stigma toward bulimia nervosa.10 page(s

FHL1 reduces dystrophy in transgenic mice overexpressing FSHD muscular dystrophy region gene 1 (FRG1)

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal-dominant disease with no effective treatment. The genetic cause of FSHD is complex and the primary pathogenic insult underlying the muscle disease is unknown. Several disease candidate genes have been proposed including DUX4 and FRG1. Expression analysis studies of FSHD report the deregulation of genes which mediate myoblast differentiation and fusion. Transgenic mice overexpressing FRG1 recapitulate the FSHD muscular dystrophy phenotype. Our current study selectively examines how increased expression of FRG1 may contribute to myoblast differentiation defects. We generated stable C2C12 cell lines overexpressing FRG1, which exhibited a myoblast fusion defect upon differentiation. To determine if myoblast fusion defects contribute to the FRG1 mouse dystrophic phenotype, this strain was crossed with skeletal muscle specific FHL1-transgenic mice. We previously reported that FHL1 promotes myoblast fusion in vitro and FHL1-transgenic mice develop skeletal muscle hypertrophy. In the current study, FRG1 mice overexpressing FHL1 showed an improvement in the dystrophic phenotype, including a reduced spinal kyphosis, increased muscle mass and myofiber size, and decreased muscle fibrosis. FHL1 expression in FRG1 mice, did not alter satellite cell number or activation, but enhanced myoblast fusion. Primary myoblasts isolated from FRG1 mice showed a myoblast fusion defect that was rescued by FHL1 expression. Therefore, increased FRG1 expression may contribute to a muscular dystrophy phenotype resembling FSHD by impairing myoblast fusion, a defect that can be rescued by enhanced myoblast fusion via expression of FHL1