bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution to Pathogenicity of the Parvovirus Minute Virus of Mice in Immunodeficient Mice Involves Genetic Heterogeneity at the Capsid Domain That Determines Tropism
Authors: López-Bueno Alberto , Segovia José C. , Bueren Juan A. , O'Sullivan M. Gerard , Wang Feng , Tattersall Peter , Almendral José M. 
Published: November 2007

ABSTRACT
Very little is known about the role that evolutionary dynamics plays in diseases caused by mammalian DNA viruses. To address this issue in a natural host model, we compared the pathogenesis and genetics of the attenuated fibrotropic and the virulent lymphohematotropic strains of the parvovirus minute virus of mice (MVM), and of two invasive fibrotropic MVM (MVMp) variants carrying the I362S or K368R change in the VP2 major capsid protein, in the infection of severe combined immunodeficient (SCID) mice. By 14 to 18 weeks after oronasal inoculation, the I362S and K368R viruses caused lethal leukopenia characterized by tissue damage and inclusion bodies in hemopoietic organs, a pattern of disease found by 7 weeks postinfection with the lymphohematotropic MVM (MVMi) strain. The MVMp populations emerging in leukopenic mice showed consensus sequence changes in the MVMi genotype at residues G321E and A551V of VP2 in the I362S virus infections or A551V and V575A changes in the K368R virus infections, as well as a high level of genetic heterogeneity within a capsid domain at the twofold depression where these residues lay. Amino acids forming this capsid domain are important MVM tropism determinants, as exemplified by the switch in MVMi host range toward mouse fibroblasts conferred by coordinated changes of some of these residues and by the essential character of glutamate at residue 321 for maintaining MVMi tropism toward primary hemopoietic precursors. The few viruses within the spectrum of mutants from mice that maintained the respective parental 321G and 575V residues were infectious in a plaque assay, whereas the viruses with the main consensus sequences exhibited low levels of fitness in culture. Consistent with this finding, a recombinant MVMp virus carrying the consensus sequence mutations arising in the K368R virus background in mice failed to initiate infection in cell lines of different tissue origins, even though it caused rapid-course lethal leukopenia in SCID mice. The parental consensus genotype prevailed during leukopenia development, but plaque-forming viruses with the reversion of the 575A residue to valine emerged in affected organs. The disease caused by the DNA virus in mice, therefore, involves the generation of heterogeneous viral populations that may cooperatively interact for the hemopoietic syndrome. The evolutionary changes delineate a sector of the surface of the capsid that determines tropism and that surrounds the sialic acid receptor binding domain.
Role of Alveolar Macrophages in Respiratory Transmission of Visna/Maedi Virus
Authors: McNeilly Tom N. , Baker Alison , Brown Jeremy K. , Collie David , MacLachlan Gerry , Rhind Susan M. , Harkiss Gordon D. 
Published: November 2007

ABSTRACTA major route of transmission ofVisna/maedi virus(VMV), an ovine lentivirus, is thought to be via the respiratory tract, by inhalation of either cell-free or cell-associated virus. In previous studies, we have shown that infection via the lower respiratory tract is much more efficient than via upper respiratory tissues (T. N. McNeilly, P. Tennant, L. Lujan, M. Perez, and G. D. Harkiss, J. Gen. Virol.88:670-679, 2007). Alveolar macrophages (AMs) are prime candidates for the initial uptake of virus in the lower lung, given their in vivo tropism for VMV, abundant numbers, location within the airways, and role in VMV-induced inflammation. Furthermore, AMs are the most likely cell type involved in the transmission of cell-associated virus. In this study, we use an experimental in vivo infection model that allowed the infection of specific segments of the ovine lung. We demonstrate that resident AMs are capable of VMV uptake in vivo and that this infection is associated with a specific up-regulation of AM granulocyte-macrophage colony-stimulating factor mRNA expression (P< 0.05) and an increase in bronchoalveolar lymphocyte numbers (P< 0.05), but not a generalized inflammatory response 7 days postinfection. We also demonstrate that both autologous and heterologous VMV-infected AMs are capable of transmitting virus after lower, but not upper, respiratory tract instillation and that this transfer of virus appears not to involve the direct migration of virus-infected AMs from the airspace. These results suggest that virus is transferred from AMs into the body via an intermediate route. The results also suggest that the inhalation of infected AMs represents an additional mechanism of virus transmission.
Thermoregulatory responses during competitive singles tennis
Authors: Morante S M , Brotherhood J R 
Published: November 2007

Objectives:To provide examples of thermoregulatory responses during competitive singles tennis and comparisons with continuous, steady-state running.Methods:Typical examples of body core (rectal) temperature, skin temperature and heart rate were selected to show the differing characteristics of tennis and running, and the corresponding thermal environments. Rectal and skin temperatures were logged each minute and heart rate logged every 15 seconds throughout the competitive “best of three sets” singles tennis matches and 60-minute continuous, steady-state running trials. Tennis matches were completed outdoors in widely varying thermal environments, and the running trials were completed in the laboratory under stable conditions.Results:Rectal temperature in tennis was raised only slightly above resting levels, reaching a plateau relative to the exercise intensity. Rectal temperature during tennis was found to take longer to reach a plateau than continuous, steady-state exercise. Skin temperature during tennis varied widely depending on environmental air temperature, and was lower than that of runners at the same air temperature. Heart rate was very similar between opponents for both average and response characteristics during tennis. A wider range and higher peak values were found for tennis players compared with runners.Conclusions:This report provides a descriptive account of thermoregulatory response characteristics during singles tennis. Differences between outdoor tennis and continuous, steady-state running in the laboratory for each of these responses were found.
The relationship between changes in interstitial creatine kinase and game-related impacts in rugby union
Authors: Smart D J , Gill N D , Beaven C M , Cook C J , Blazevich A J 
Published: November 2007

Aim:The primary purpose of this study was to investigate the relationship between the pre-game to post-game changes in creatine kinase concentration (Δ[CK]) and impact-related game statistics in elite rugby union players.Methods:Twenty-three elite male rugby union players each provided interstitial fluid samples obtained via electrosonophoresis (ESoP) 210 min before and within a maximum time of 30 min after up to five rugby union games. Specific game statistics that were deemed to be important in determining the relationship between impact and [CK] were obtained from AnalyRugby software for each individual player. Regression equations to predict Δ[CK] from game statistics were created using a backwards random-effects maximum likelihood regression.Results:The Δ[CK] (mean (SD)) from pre-game to post-game was 926.8 (204.2) IU. Game time and time defending were significantly correlated to Δ[CK] in both the forwards and backs. The predicted Δ[CK] (mean (95% confidence limit)) was 1439.8 (204.9) IU for the forwards and 545.3 (78.0) IU for the backs and was significantly correlated with the actual Δ[CK] (r = 0.69 and r = 0.74).Conclusions:CK increased from pre-game to post-game in a position-specific manner. A large proportion of the Δ[CK] can be explained by physical impact and thus can be predicted using a prescribed number of game statistics. As the Δ[CK] is an indicator of muscle damage, the prediction of Δ[CK] provides a theoretical basis for recovery strategies and adjustment of subsequent training sessions after rugby union games.
Disease burden of adult lung cancer and ischaemic heart disease from passive tobacco smoking in China
Authors: Gan Quan , Smith Kirk R , Hammond S Katharine , Hu Teh-wei 
Published: November 2007

Objective:To address the health hazards tobacco smoking imposes upon non-smokers in China, this paper estimates the burden of diseases in adults from passive tobacco smoking for two major diseases—lung cancer and ischaemic heart disease (IHD).Methods:The disease burden was estimated in terms of both premature mortality and disability adjusted life years (DALYs), a measure that accounts for both the age at death and the severity of the morbidity.Results:Passive smoking caused more than 22 000 lung cancer deaths in 2002 according to these estimates. When the toll of disability is added to that of mortality, passive smoking was responsible for the loss of nearly 230 000 years of healthy life from lung cancer. Using the evidence from other countries that links IHD to passive smoking, we estimated that approximately 33 800 IHD deaths could be attributable to passive smoking in China in 2002. Passive smoking is also responsible for the loss of more than one quarter of a million years of healthy life from IHD. Although most of the disease burden caused by active smoking occurs among men, women bear nearly 80% of the total burden from passive smoking. The number of deaths among women caused by passive smoking is about two-thirds of that caused by smoking for the two diseases we examined.Conclusion:Even without considering the passive smoking risks for other diseases and among children that have been documented in other countries, passive smoking poses serious health hazards for non-smokers, especially for adult female non-smokers in China, adding more urgency to the need for measures to be taken immediately to protect the health of non-smokers and curb the nation’s tobacco epidemic.
Use of nicotine replacement therapy to reduce or delay smoking but not to quit: prevalence and association with subsequent cessation efforts
Authors: Levy Douglas E , Thorndike Anne N , Biener Lois , Rigotti Nancy A 
Published: November 2007

Objective:To assess the prevalence of nicotine replacement therapy (NRT) use for purposes other than quitting smoking and examine the relation of this non-standard NRT use (NSNRT) with subsequent smoking cessation efforts.Design:A population based cohort study of adult smokers who were interviewed by telephone at baseline (2001–2) and at two year follow-up. The association between NSNRT use to cut down on smoking or to delay smoking before baseline and cessation attempts and smoking outcomes at two year follow-up was assessed using logistic regression to adjust for multiple potential confounding factors.Setting:Massachusetts, USA.Subjects:1712 adult smokers in Massachusetts who were selected using a random digit dial telephone survey.Main outcome measures:Quit attempt in 12 months before follow-up, NRT use at quit attempt in 12 months before follow-up, smoking cessation by follow-up, or 50% reduction in cigarettes smoked per day between baseline and follow-up.Results:18.7% of respondents reported ever having used NSNRT. In a multiple logistic regression analysis, there was no statistically significant association between past NSNRT use and quit attempts (ORcut down = 0.89, 95% CI 0.59 to 1.33; ORdelay = 1.29, 95% CI 0.73 to 2.29), smoking cessation (ORcut down = 0.74, 95% CI 0.43 to 1.24; ORdelay = 1.22, 95% CI 0.60 to 2.50) or 50% reduction in cigarettes smoked per day (ORcut down = 0.93, 95% CI 0.62 to 1.38; ORdelay = 0.80, 95% CI 0.43 to 1.49) at follow-up. Past use of NRT to cut down on cigarettes was associated with use of NRT at a follow-up quit attempt (ORcut down = 2.28, 95% CI 1.50 to 3.47) but past use of NRT to delay smoking was not (ORdelay = 1.25, 95% CI 0.67 to 2.34).Conclusions:Use of NRT for reasons other than quitting smoking may be more common than was previously estimated. This population based survey finds no strong evidence that NRT use for purposes other than quitting smoking is either harmful or helpful.
Assessing the impact of smoking cessation services on reducing health inequalities in England: observational study
Authors: Bauld Linda , Judge Ken , Platt Stephen 
Published: November 2007

Objective:NHS stop smoking services are expected to play a key part in achieving the infant mortality and life expectancy health inequality targets in England by reducing smoking prevalence in deprived areas. This paper assesses the extent to which services have made a contribution to reducing inequalities in smoking between 2003–4 and 2005–6.Methods:Synthetic estimates of baseline smoking prevalence data were compared with national monitoring data about the numbers of smokers in receipt of services and the proportion who self report quitting at four weeks. The social distribution of service recipients and quitters was compared with estimates of smoking prevalence to assess impact on inequalities. Comparisons were made between officially designated disadvantaged areas (the Spearhead Group) and others.Results:Short-term cessation rates were lower in disadvantaged areas (52.6%) than elsewhere (57.9%) (p<0.001), but the proportion of smokers being treated was higher (16.7% compared with 13.4%) (p<0.001). The net effect was that a higher proportion of smokers in the most disadvantaged areas reported success (8.8%) than in more advantaged areas (7.8%) (p<0.001). Using the evidence-based assumption that three-quarters of short-term quitters will relapse within one year, the absolute and relative rate gaps in smoking prevalence between Spearhead areas and others are estimated to fall by small but statistically significant amounts from 5.2 and 1.215 (CIs: 1.216 to 1.213) to 5.0 and 1.212 (CIs: 1.213 to 1.210) between 2003–4 and 2005–6.Conclusion:NHS stop smoking services have probably made a modest contribution to reducing inequalities in smoking prevalence. To achieve government targets, however, requires both the development of more innovative cessation interventions for the most addicted smokers and action to ensure that other aspects of tobacco control policy make a larger contribution to inequality goals.
Effect of in-season creatine supplementation on body composition and performance in rugby union football players
Authors: Chilibeck Philip D. , Magnus Charlene , Anderson Matthew 
Published: November 2007

Rugby union football requires muscular strength and endurance, as well as aerobic endurance. Creatine supplementation may enhance muscular performance, but it is unclear if it would interfere with aerobic endurance during running because of increased body mass. The purpose of this study was to determine if creatine supplementation during 8 weeks of a season of rugby union football can increase muscular performance, without negatively affecting aerobic endurance. Rugby union football players were randomized to receive 0.1 g·kg–1·d–1 creatine monohydrate (n = 9) or placebo (n = 9) during 8 weeks of the rugby season. Players practiced twice per week for approximately 2 h per session and played one 80 min game per week. Before and after the 8 weeks, players were measured for body composition (air displacement plethysmography), muscular endurance (number of repetitions at 75% of one repetition maximum (1 RM) for bench press and leg press), and aerobic endurance (Leger shuttle-run test with 1 min stages of progressively increasing speed). There were time main effects for body mass (–0.7 ± 0.4 kg; p = 0.05), fat mass (–1.9 ± 0.8 kg; p < 0.05), and a trend for an increase in lean tissue mass (+1.2 ± 0.5 kg; p = 0.07), with no differences between groups. The group receiving creatine supplementation had a greater increase in the number of repetitions for combined bench press and leg press tests compared with the placebo group (+5.8 ± 1.4 vs. +0.9 ± 2.0 repetitions; p < 0.05). There were no changes in either group for aerobic endurance. Creatine supplementation during a rugby union football season is effective for increasing muscular endurance, but has no effect on body composition or aerobic endurance.
Associations between abdominal adiposity, exercise, morbidity, and mortality
Authors: Kuk Jennifer Linchee 
Published: November 2007

The increasing prevalence of abdominal obesity worldwide poses a serious public health problem and thus presents a target for research designed to improve the assessment or treatment of abdominal obesity. Specifically, the first study in this thesis investigated the influence of age and gender on visceral (VAT) and abdominal (ASAT) subcutaneous adipose tissue for a given waist circumference (WC) in 481 men and women varying widely in age and body mass index (BMI). Significant gender differences in VAT and ASAT for a given WC were observed; however, only the relationship between WC and VAT was substantially influenced by age. The second study examined whether the associations between VAT, ASAT, and the metabolic syndrome (MetS) were altered depending on the measurement methodology used to assess VAT and ASAT. The odds ratio (OR) for MetS was higher for total VAT volume (OR = 7.26), and for partial volumes at T12–L1 (OR = 7.46) and L1–L2 (OR = 8.77) compared with the classic L4–L5 (OR = 3.94) measurement. The OR for MetS was not substantially different among the ASAT measures (OR∼2.6). Measurement site for VAT, but not ASAT, has a substantial influence on the magnitude of the association with MetS. The third study examined the independent associations between VAT, ASAT, liver fat, and all-cause mortality in 291 men (97 decedents and 194 controls, mortality follow-up of 2.2 ± 1.3 y). In a model including VAT, ASAT, liver fat, age, and length of follow-up, only VAT (1.93 (1.15–3.23)) remained a significant predictor of mortality. We concluded that VAT is a strong, independent predictor of all-cause mortality in men. The purpose of the final study was to determine the effect of aerobic exercise dose (energy expenditure) on WC in sedentary, overweight or obese postmenopausal women (n = 424). The women were randomly assigned to a control group or one of three aerobic exercise groups that exercised at energy expenditures of 4, 8, or 12 kcal·kg body mass–1·week–1. On comparison with controls, there were significant reductions in WC in the exercise groups (~3 cm, p < 0.05), which were independent of weight loss. However, the amount of exercise performed was not associated with reductions in WC in a dose-dependent manner.
Physical activity guidelines for children and youthThis article is part of a supplement entitled Advancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelines co-published by Applied Physiology, Nutrition, and Metabolism and the Canadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab. 32(Suppl. 2E) or as Can. J. Public Health 98(Suppl. 2).
Authors: Janssen Ian 
Published: November 2007

The aim of this review is to provide a scientific update on evidence related to the biological and psycho-social health benefits of physical activity in school-aged children and youth. To accomplish this aim, the first part of the paper reviews existing physical activity guidelines for school-aged children and youth, with an emphasis placed on how Canada’s guidelines compare and contrast with those of other countries and organizations. The paper then provides an overview of physical activity levels of Canadian children and youth, which indicates that few Canadian youngsters meet current physical activity recommendations. The next section of the paper summarizes the literature that informs how much physical activity is required to promote health and well-being in children and youth. The paper then provides suggestions on modifications that could be made to Canada’s physical activity guidelines for children and youth. Specifically, consideration should be given to setting both minimal (≥60 min/d) and optimal (up to several hours per day) physical activity targets. The final section identifies future research needs. In this section, a need is noted for comprehensive dose–response studies of physical activity and health in the paediatric age group.
Physical activity for preschool children — how much and how?This article is part of a supplement entitledAdvancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelinesco-published byApplied Physiology, Nutrition, and Metabolismand theCanadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab. 32(Suppl. 2E) or as Can. J. Public Health 98(Suppl. 2).
Authors: Timmons Brian W. , Naylor Patti-Jean , Pfeiffer Karin A. 
Published: November 2007

Alarming trends in childhood obesity even among preschool children have re-focused attention on the importance of physical activity in this age group. With this increased attention comes the need to identify the amount and type of physical activity appropriate for optimal development of preschool children. The purpose of this paper is to provide the scientific evidence to support a link between physical activity and biological and psychosocial development during early childhood (ages 2–5 years). To do so, we summarize pertinent literature informing the nature of the physical activity required to promote healthy physical, cognitive, emotional, and social development during these early years. A particular focus is on the interaction between physical activity and motor skill acquisition. Special emphasis is also placed on the nature of physical activity that promotes healthy weight gain during this period of childhood. The paper also discusses the strongest determinants of physical activity in preschool-age children, including the role of the child’s environment (e.g., family, child-care, and socio-economic status). We provide recommendations for physical activity based on the best available evidence, and identify future research needs.
The effects of whole-body vibration on upper- and lower-body EMG during static and dynamic contractions
Authors: Hazell Tom J. , Jakobi Jennifer M. , Kenno Kenji A. 
Published: November 2007

Whole-body vibration (WBV) training uses a vertically oscillating platform and reports suggest that this perturbation elicits reflexive muscle contractions that augment muscle activity and contribute to increased strength. No WBV study has measured both upper- and lower-body muscle activation. The purpose of this study was to determine the optimal WBV stimulus (frequency × amplitude) to increase electromyography (EMG) in upper- and lower-body muscles for three distinctive unloaded actions: isometric semi-squat, dynamic leg squats, and static and dynamic bilateral bicep curls. Surface EMG was measured for the vastus lateralis (VL), biceps femoris (BF), biceps brachii (BB), and triceps brachii (TB) in 10 recreationally active male university students (24.4 ± 2.0 years; mean ± SD) when WBV was administered at 2 and 4 mm and at 25, 30, 35, 40, and 45 Hz. EMG changes are reported as the difference between WBV and no WBV EMG root mean square expressed as a percentage of maximum voluntary exertion (%MVE). In static semi-squat, WBV increased muscle activity 2.9%–6.7% in the VL and 0.8%–1.2% in the BF. During dynamic squatting, WBV increased muscle activity in the VL by 3.7%–8.7% and in the BF by 0.4%–2.0%. In a static biceps curl, WBV had no effect on BB EMG, but did increase TB activity 0.3%–0.7%. During dynamic biceps curls, WBV increased BB EMG activity by 0.6%–0.8% and TB activity by 0.2%–1.0%. The higher WBV amplitude (4 mm) and frequencies (35, 40, 45 Hz) resulted in the greatest increases in EMG activity.