Search

The purpose of this study was to examine the effects of exercising at different intensities over 7 weeks on components of physical fitness and CVD risk factors. Forty-seven boys and 10 girls, (16.4±0.7 years of age) were divided into a moderate, high intensity, or a control group. All participants had indices of obesity and blood pressure recorded in addition to four physical performance measures pre- and post-intervention. In addition, the intervention groups repeated the physical performance measures at the 4th week phase of the intervention. Following the intervention, significant improvements (P

Cardiovascular disease (CVD) remains one of the leading causes of morbidity and mortality in developed countries. Over the past decade there has been much focus on the role of inflammation in the pathogenesis of atherosclerosis; to this end, there is increasing research on inflammatory factors such as C-reactive protein (CRP), interleukin-6 (IL-6), and fibrinogen (Fg). There is compelling evidence that physical activity (PA) and physical fitness (PF) protect against chronic disease. More recently, research has shown that exercise reduces CRP, IL-6, and Fg concentration in adults, and that this is often independent of adiposity. Although there are some data to suggest that this is similarly true for young people, there is inconsistency in the literature. The following review aims to illustrate what is known about the effects of PA and PF on inflammatory factors in young people aged 5-18 years.

The purpose of this study was to examine relationships between aerobic fitness (AF), fatness, and coronary-heart-disease (CHD) risk factors in 12- to 13-year-olds. The data were obtained from 208 schoolchildren (100 boys; 108 girls) ages 12.9 ± 0.3 years. Measurements included AF, indices of obesity, blood pressure, blood lipids and lipoproteins, fibrinogen, homocysteine, and C-reactive protein. An inverse relationship was found between AF and fatness (p < .05). Fatness was related to a greater number of CHD risk factors than fitness was (p < .05). Further analysis revealed fatness to be an independent predictor of triglyceride and blood-pressure levels (p < .05). Our findings indicate that, for young people, fatness rather than fitness is independently related to CHD risk factors.

This study determined the prevalence of coronary heart disease (CHD) risk factors in young people1of differing socio-economic status (SES). A cohort of 100 boys and 108 girls, aged 12.9, SD 0.3 years drawn of differing SES were assessed for CHD risk factors. Measurements included indices of obesity, blood pressure, aerobic fitness, diet, blood lipids and lipoproteins. Significant differences ( P ≤ 0.05) were detected with respect to SES, for systolic blood pressure, total cholesterol and low density lipopro tein cholesterol, but in boys only. Significant sex differences ( P ≤ 0.05) were identified for systolic blood pressure, diastolic blood pressure, aerobic fitness, waist to hip ratio, summation of four skinfold thicknesses, average daily kilocalorie intake, total choles terol and low density lipoprotein cholesterol. Moreover, increased body fatness, low aerobic fitness, a high fat diet and elevated lipoprotein (a), were the most frequently identified CHD risk factors in this cohort. This study reveals a high incidence of CHD risk factors in young people irrespective of SES and sex, and highlights the need for vigilance in identifying such risk factors from a young age.

This study assesses the prevalence of recently identified coronary heart disease (CHD) risk factors in young people of differing socioeconomic status (SES). From November 2001 through March 2002, 100 boys and 108 girls, of age 12.9 +/- 0.3 years, selected from differing SES were assessed for CHD risk factors. Measurements included fibrinogen (Fg), homocyst(e)ine (Hcy), and C-reactive protein (CRP). Fibrinogen was significantly greater among boys from a higher SES compared with those from a low SES (Por = 0.05). Differences according to sex (Por = 0.05) were identified for Fg and CRP. The data indicate the prevalence of recently identified CHD risk factors in this cohort of British schoolchildren. For the purpose of this article, the phrase "young people" embraces both children and adolescents.

Incident detection systems typically emphasize incident presence and location over incident severity and incident recovery. Yet, Advanced Traveller Information Systems (ATIS) and Advanced Traffic Management Systems (ATMS) rely on the latter states to implement and terminate diversion, and its supportive control strategies. Further, incident detection systems directly benefit from processing measurement vectors rather than scalars. Vectors of lane measurements favor detection through lane imbalances and identification of incident host lanes. Intelligent Transportation Systems promise new sensor data to control centers, including the travel times experienced by probe vehicles. Vectors of new and old sensor inputs may possess enhanced discriminatory values. To accomodate added detection states and the fusion of multi-sensor input vectors, this paper reformulates the arterial incident detection problem as a multiple attribute decision making problem with Bayesian scores. This novel approach utilizes as input the combinations of simulated probe travel times, number of probe reports, lane specific detector occupancies and vehicle counts. Models based solely on probe data lack in performance due to excessive overlaps in class distributions. Models based on detector occupancies and vehicle counts by lane perform outstandingly. They display a propensity to detect through lane measurement imbalances. The probe data is shown to enhance the performance of detector data based models.

The topology of the contact seam of human erythrocytes adhered by dextran, an uncharged polymer, has been examined. Particular attention has been paid to the influence of electrostatic intermembrane interactions since their magnitude and range can be accurately estimated. Normal cells formed a continuous seam, whereas erythrocytes with pronase-modified glycocalices formed localized contact points on adhesion in 72 kDa dextran in buffered 145 mM NaCl. The dependence of the inter-contact distance lambda on dextran concentration [D] over the range 2-6% w/v, was given by lambda = C[D]-0.62, where C was a constant. The index of [D] was independent of dextran molecular mass over the range 20 to 450 kDa. The inter-contact distance for pronase-pretreated cells in 6% w/v 72 kDa dextran increased from 0.78 to 1.4 microns as [NaCl] was reduced through the range 145 to 90 mM and the suspending phase was maintained at isotonicity by using sorbitol to replace NaCl. The formation and lateral separation of the contact points are discussed from the perspective of linear interfacial instability theory. The theory allows a quantitative explanation for the experimentally observed dependence of inter-contact distance and of disturbance growth rate on change in electrostatic interaction. The results suggest that the dominant wavelength, determining the inter-contact distance, is established on approaching membranes when the layers of cell surface charge are separated by a perpendicular distance of < 14 nm (bilayer separation of 24 nm).

Models of cell plasma membrane interactions in the presence of adhesive macromolecules often follow the general principles initially formalised by Derjaguin, Landau, Verwey and Overbeek for colloidal particles in suspension. In this model the parallel membranes of mutually adhering cells are considered to lie in an energy minimum at an equilibrium separation distance which is determined by the relative size and range of attractive and repulsive interactions. In contrast, the interfacial instability model considered here directs attention to the dynamic processes which can result in deformation of a thin aqueous intermembrane film to give localised spatially periodic contact points. The contact seam of erythrocytes suspended in polycation, polysaccharide or lectin solutions has been examined in this work by light and electron microscopies. The seams formed by erythrocytes in solutions of the lectins concanavalin A and wheat germ agglutinin show spatial periodicity of contacts (range 0.8-0.5 μm). In normal cells the polycation-induced seam is always spatially periodic while it is usually continuous and parallel in dextran solutions. In the latter case, pretreatment of the cells by the protease pronase results in spatially periodic contacts on subsequent exposure of the cells to dextran. For both polycation- and polysaccharide-induced contact the experimental changes which increase or decrease membrane attraction consistently lead to a decrease or increase respectively in the lateral contact separation distance (range 3.4–0.8 μm). These changes in lateral contact separation distances are qualitatively consistent with the predictions of interfacial instability theory. The changes are discussed as particular examples of a general consequence of the form of membrane interaction profiles.

This study examines CVD risk factors trends in Welsh adolescents between 2002 and 2007.CVD risk factor data was examined from two cross-sectional studies. The first study (73 participants; aged 12.9 ± 0.3 years) was completed in 2002. The second study (90 participants; aged 12.9 ± 0.4 years) was conducted in 2007. Measurements included body mass index (BMI), waist circumference (WC), total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, fibrinogen (Fg) and high-sensitivity C-reactive protein (hs-CRP).In boys, mean BMI and WC were lower in 2007, although not significantly (p ≥ 0.05). In 2007, there were improvements in mean lipid, Fg and hs-CRP concentrations in both sexes (p0.05). In 2002, 42.8% of boys and 34.2% of girls were overweight or obese; in 2007, this was 23.7% and 28.9% for boys and girls, respectively. More adolescents in 2002 exceeded the recommended levels for lipids, Fg and hs-CRP.This is the only study to examine CVD risk factor trends in Welsh adolescents. Although overweight continues to be widespread in 12-13 year olds, this study did not identify significant mean changes in overweight and obesity between 2002 and 2007. Overall, the data presented a positive trend in lipid profile and inflammatory factors.

The current drastic escalation in obesity may be contributing to the exponential rise in drugs used for image enhancement. Drugs such as anabolic-androgenic steroids (AAS) are perceived as a viable method of achieving a perfect physique. They are also the most widely abused drugs in sport. The Internet has encouraged the abuse of expensive drugs, particularly human growth hormone (hGH), resulting in increased importation for personal use. The substantial increase in this market has opened up avenues for counterfeiting, estimated as a multi-million pound business. The acute adverse effects from contaminated vials may result in a variety of pathologies including communicable diseases. In 2007, in the UK, a series of intramuscular abscesses, requiring surgical treatment, led us to study samples obtained from the underground market. The analysis of 38 parenteral samples and 19 oral samples of tablets was performed by a World Anti-Doping Agency (WADA) accredited laboratory, in an attempt to establish the extent of available counterfeit products. Fifty-three per cent (20) of the injectable AAS esters and 21% (4) of the oral tablets were counterfeit. Culture and sensitivity revealed the presence of skin commensal organisms, which may have contributed to the development of the abscesses. Users of AAS and hGH for sport, including bodybuilding, are currently risking their health because of counterfeit and poorly controlled products.

Arterial endothelial dysfunction is an early event in the pathogenesis of atherosclerosis and predisposes individuals to the deposition of unstable atherosclerotic plaques. It can also lead to increased arterial stiffness, which is an accepted cause of increased arterial pulse wave velocity (APWV). Endothelial dysfunction is reversed by recombinant human growth hormone (rhGH) therapy in patients with growth hormone (GH) deficiency (GHD), favorably influencing the risk for atherogenesis. Endogenous human growth hormone (hGH), secreted by the anterior pituitary, and levels of insulin-like growth factor-I (IGF-I), produced in response to hGH stimulation of the liver, peak during early adulthood, but decline throughout adulthood. It is suspected that low-grade inflammatory cardiovascular pathophysiologic markers such as homocysteine, nitric oxide, C-reactive protein (CRP), and fibrinogen and plasminogen activator inhibitor along with changes in lipid and glucose metabolism may all contribute to GHD-associated metabolic and cardiovascular complications. These effects are associated with increased APWV, but are attenuated by rhGH therapy in GHD. GH replacement increases IGF-I levels and reduces CRP and large-artery stiffness. Reviews of rhGH in the somatopause have not been overtly favorable. Whereas reviews of rhGH/rhIGF-I combinations in GH resistance are more positive than those for rhGH alone, their combined use in the somatopause is limited. Senescent individuals may benefit from such a combination.

Athletes have enjoyed almost a thirty year amnesty of rhGH abuse, which they consider has contributed to the winning of medals and the breaking of world records. Such a reprieve is almost at an end, since WADA have identified a method to detect rhGH abuse. Or have they? The anecdotal word "on the street" is that rhGH is still undetectable and athletes believe that the benefits, at the dosages they administer, far outweigh the risks! Scientists are aware that in a hormone deficiency condition, replacement can halt and in certain situations reverse some of the adverse effects. Growth hormone deficiency can lead to a loss of skeletal muscle mass and an increase in abdomino-visceral obesity, which is reversed on replacement with rhGH. Since the availability of GH, athletes have been trying to extrapolate these effects from the deficiency state to the healthy corpus and increase their sporting prowess. Past confessions from athletes, such as Ben Johnson, Kelly White, Tim Montgomery, Marion Jones and currently Dwain Chambers have demonstrated that they are prepared to tread the very fine lines that separate the "men from the boys". Rewards are so great, that anonymous surveys have identified that athletes will risk ill health, if they believe they can cheat, win and not get caught. The question that still needs to be answered is, "does growth hormone enhance performance"? Recent research suggests that it could. There is also a suspicion that in "cycled" low supraphysiological doses, it is no where near as harmful as WADA claim it to be.

Lipoprotein(a) (Lp(a)) is a distinctive cholesterol-rich lipoprotein complex in blood. Population studies show that Lp(a) levels are not normally distributed but are skewed towards low concentrations of 30 mg/dl−1, the threshold level nominated for cardiovascular disease (CVD) risk in both children and adults.1 Although Lp(a) takes the form of an independent risk factor,1 it is the combined elevated levels of Lp(a) and low-density lipoprotein cholesterol (LDL-C), or Lp(a) and fibrinogen (Fg) that is thought to have the greatest detrimental effect.2 3 We determined the Lp(a) concentrations in schoolchildren aged 12–13 years in South Wales, as well as the percentage of children exhibiting …

The aim was to investigate secular trends in cardiovascular disease (CVD) risk factors in Welsh adolescents between 2002 and 2007. CVD risk factor data were examined from two school-based cross-sectional studies. The initial study (September to October, 2002) included 73 participants, aged 12.9±0.3 years. The final study of 90 participants, aged 12.9±0.4 years, was completed during September to October, 2007. Measurements included adiposity, physical activity (PA), physical fitness (PF), diet, total cholesterol, high-density-lipoprotein cholesterol, low-density-lipoprotein cholesterol, triglyceride, fibrinogen (Fg) and high-sensitivity C reactive protein (hs-CRP). On both occasions, testing was carried out in the same school, and by the same experienced researcher using identical procedure. PA and PF levels improved for boys and girls in 2007; however, 80% of girls still did not meet the recommended 1 h/day of moderate PA. For both sexes, dietary fat intake did not differ between 2002 and 2007 cohorts; Welsh adolescents continued to consume a diet that was too high in saturated fat. Although mean adiposity tended to decrease between 2002 and 2007 in boys, this was not significant (p≥0.05). Overall, there were improvements in mean lipid profile and inflammatory status (p