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1.
Prev Vet Med ; 127: 64-9, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-27094142

RESUMO

Canine obesity is increasing in prevalence in the UK and raises concerns about dog welfare. This study compares the health-related quality of life (HRQL) of dogs of varying body condition: overweight and obese (BCS 4 and 5) versus non-overweight dogs (BCS 2 and 3), obese (BCS 5) versus non-overweight (BCS 2 and 3) and an overall comparison between all four BCS (BCS 2, 3, 4 and 5) using a novel, validated HRQL instrument which is both web and mobile tablet/phone app based. Of 271 dog owners who were approached, 174 completed a web-based instrument (2013) or a mobile tablet app instrument (2014) during the summers of 2013 and 2014. Automatically generated scores in four domains of HRQL (energetic/enthusiastic, happy/content, active/comfortable, calm/relaxed) were compared for dogs with each of the body condition scores (BCS 2-5). For all body condition scores a statistically significant difference was found between the HRQL scores in two of the domains: energetic/enthusiastic (p=0.02) and active comfortable (p=0.004). When BCS 2 and 3 were compared to BCS 4 and 5, statistical significance was found in the same two domains - energetic/enthusiastic (p=0.01) and active comfortable (p=0.001) - as it was in comparison of non-overweight (BCS 2 and 3) compared to obese dogs (BCS 5): energetic/enthusiastic (p=0.012) and active comfortable (p=0.004). These results suggest that overweight and obese dogs have a reduced HRQL in two of the domains compared to non-overweight dogs, and that differences in HRQL are detectable between BCS scores 2, 3, 4 and 5.


Assuntos
Doenças do Cão/epidemiologia , Obesidade/veterinária , Sobrepeso/veterinária , Qualidade de Vida , Animais , Doenças do Cão/etiologia , Cães , Feminino , Masculino , Obesidade/epidemiologia , Obesidade/etiologia , Sobrepeso/epidemiologia , Sobrepeso/etiologia , Inquéritos e Questionários , Reino Unido/epidemiologia
2.
J Musculoskelet Neuronal Interact ; 13(4): 395-404, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24292609

RESUMO

OBJECTIVES: Musculoskeletal development of the upper limbs during exposure to weight-bearing loading is under-researched during early pubescent growth. The purpose was to assess the changes in upper body musculoskeletal strength in young girls following 6 months of non-elite gymnastics participation. METHODS: Eighty-four girls, 6-12 years were divided into groups based on gymnastics participation: high-training (HGYM, 6-16 hr/wk), low-training (LGYM, 1-5 hr/wk), and non-gymnasts (NONGYM). Volumetric BMD, bone geometry, estimated bone strength and muscle size were assessed at the non-dominant forearm (4% and 66% radius and ulna) with pQCT. DXA assessed aBMD and body composition. Tests for explosive power, muscle strength, and endurance were also performed. RESULTS: Interaction effects were observed in all variables at the 4% radius. At the 66% ulna, HGYM and LGYM had greater bone mass, size and bone strength than NONGYM, furthermore a dose-response relationship was observed at this location. Body composition was better for HGYM than LGYM and NONGYM, however muscle function was better for HGYM and LGYM than NONGYM. CONCLUSION: The greatest changes were obtained with more than one gymnastics class per week. Separating gymnastics participation-related changes from those associated with normal growth and development remains difficult, particularly at the 4% radius.


Assuntos
Densidade Óssea/fisiologia , Antebraço/diagnóstico por imagem , Ginástica/fisiologia , Rádio (Anatomia)/diagnóstico por imagem , Ulna/diagnóstico por imagem , Criança , Feminino , Antebraço/fisiologia , Humanos , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Tomografia Computadorizada por Raios X , Suporte de Carga/fisiologia
3.
Int J Sports Med ; 34(8): 688-94, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23371826

RESUMO

Our aim was to use Peripheral Quantitative Computed Tomography (pQCT) to assess the bone health of male and female apprentice jockeys and age- and sex-matched peers. 2 groups of 25 young adults (n=50) (age range 15-38 years) were comprised of male and female apprentice jockeys, and male and female controls. We used pQCT to measure the distal tibia and distal radius. After covarying for weight and limb length, apprentice jockeys displayed less tibial cortical area and lower strength strain index at 14% distal shaft, 38% mid shaft and 66% proximal sites measured distally than controls (p=0.001). No between group differences were found in cortical density, trabecular area, and trabecular density at the tibia. Compared with controls, apprentice jockeys displayed greater trabecular density at the distal radial site (p=0.001), greater strength strain index at 66% proximal site measured distally (p=0.01), and a lower strength strain index at the distal radius (p=0.006). In conclusion, only trabecular density at the distal radius and strength strain index at the proximal radius were greater in apprentice jockeys than controls. Strategies to increase bone density and bone strength in apprentice jockeys should be considered by relevant industry stakeholders and their health providers.


Assuntos
Atletas , Densidade Óssea/fisiologia , Osso e Ossos/metabolismo , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Animais , Osso e Ossos/diagnóstico por imagem , Feminino , Cavalos , Humanos , Masculino , Rádio (Anatomia)/metabolismo , Esportes , Tíbia/metabolismo , Adulto Jovem
4.
Osteoporos Int ; 23(4): 1277-86, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21660556

RESUMO

UNLABELLED: Recent reports indicate an increase in forearm fractures in children. Bone geometric properties are an important determinant of bone strength and therefore fracture risk. Participation in non-elite gymnastics appears to contribute to improving young girls' musculoskeletal health, more specifically in the upper body. INTRODUCTION: The primary aim of this study was to determine the association between non-elite gymnastics participation and upper limb bone mass, geometry, and strength in addition to muscle size and function in young girls. METHODS: Eighty-eight pre- and early pubertal girls (30 high-training gymnasts [HGYM, 6-16 hr/ wk], 29 low-training gymnasts [LGYM, 1-5 h r/wk] and 29 non-gymnasts [NONGYM]), aged 6-11 years were recruited. Upper limb lean mass, BMD and BMC were derived from a whole body DXA scan. Forearm volumetric BMD, bone geometry, estimated strength, and muscle CSA were determined using peripheral QCT. Upper body muscle function was investigated with muscle strength, explosive power, and muscle endurance tasks. RESULTS: HGYM showed greater forearm bone strength compared with NGYM, as well as greater arm lean mass, BMC, and muscle function (+5% to +103%, p < 0.05). LGYM displayed greater arm lean mass, BMC, muscle power, and endurance than NGYM (+4% to +46%, p < 0.05); however, the difference in bone strength did not reach significance. Estimated fracture risk at the distal radius, which accounted for body weight, was lower in both groups of gymnasts. Compared with NONGYM, HGYM tended to show larger skeletal differences than LGYM; yet, the two groups of gymnasts only differed for arm lean mass and muscle CSA. CONCLUSION: Non-elite gymnastics participation was associated with musculoskeletal benefits in upper limb bone geometry, strength and muscle function. Differences between the two gymnastic groups emerged for arm lean mass and muscle CSA, but not for bone strength.


Assuntos
Densidade Óssea/fisiologia , Ginástica/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Puberdade/fisiologia , Absorciometria de Fóton/métodos , Antropometria/métodos , Composição Corporal/fisiologia , Criança , Estudos Transversais , Feminino , Antebraço/fisiologia , Humanos , Músculo Esquelético/anatomia & histologia , Resistência Física/fisiologia
5.
Aesthetic Plast Surg ; 36(2): 431-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21735336

RESUMO

BACKGROUND: Laser resurfacing procedures are continuing to grow in popularity as patients select less invasive procedures for rejuvenation of photo-damaged and aging skin. However, although physicians have begun exploring options to aid in postlaser healing, currently available treatments have little clinical evidence to support their use for wounded skin. METHODS: When grown under conditions of very low oxygen and suspension, a simulation of the embryonic environment, neonatal cells have been found to produce proteins and growth factors in types and quantities similar to those of fetal cells. The human cell-conditioned media (hCCM) produced by the cells was extracted and formulated into a gel to evaluate its efficacy in the healing of postlaser wounds. RESULTS: A split-face clinical evaluation of the material was performed, with 42 subjects undergoing combination ablative and nonablative laser procedures. Three concentrations of the hCCM were tested (× 0.1, × 1.0, × 10.0), and a dose-response trend was seen in the blinded physician evaluation, particularly in the assessment of crusting. In addition, transepidermal water loss readings showed a significant difference (p ≤ 0.05), indicating a more rapid return to normal skin barrier function with the active treatment. Histopathologic evaluation of subject biopsies showed reduced inflammation and a more normal epidermal appearance in the active treatment sites. CONCLUSIONS: The results of this clinical evaluation support the use of the soluble hCCM produced under embryonic-like conditions to accelerate wound healing after laser resurfacing procedures. The utility of the × 10 concentration appears to promote more rapid, scarless wound healing after resurfacing procedures and more normal skin recovery.


Assuntos
Meios de Cultivo Condicionados/farmacologia , Terapia a Laser , Cicatrização/efeitos dos fármacos , Reatores Biológicos , Relação Dose-Resposta a Droga , Eritema/prevenção & controle , Géis , Humanos , Rejuvenescimento , Perda Insensível de Água/fisiologia
6.
J Musculoskelet Neuronal Interact ; 11(3): 227-33, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21885897

RESUMO

OBJECTIVE: To compare skeletal parameters between the ulna and radius in pre-pubertal non-elite gymnasts and non-gymnasts. METHODS: Fifty-eight non-elite artistic gymnasts, aged 6-11 years, were compared with 28 non-gymnasts for bone mineral content (BMC), total and cortical bone area (ToA, CoA), trabecular and cortical volumetric density (TrD, CoD) and estimated bone strength (BSI and SSIp), obtained by pQCT at the distal and proximal forearm. RESULTS: Gymnasts had greater estimated bone strength than non-gymnasts at both sites of the forearm. At the distal forearm, the gymnastics-induced skeletal benefits were greater at the radius than ulna (Z-scores for BMC, TrD and BSI +0.40 to +0.61 SD, p<0.05 vs. +0.15 to +0.48 SD, NS). At the proximal forearm, the skeletal benefits were greater at the ulna than the radius (Z-scores for BMC, ToA, CoA and SSIp +0.59 to +0.82 SD, p<0.01 vs. +0.35 (ToA) and +0.43 SD (SSIp), p<0.01). CONCLUSION: Skeletal benefits at the distal and proximal forearm emerged in young non-elite gymnasts. Benefits were larger when considering skeletal parameters at both the ulna and radius, than the radius alone as traditionally performed with pQCT. These findings suggest the ulna is worth investigating in future studies aiming to accurately quantify exercise-induced skeletal adaptations.


Assuntos
Ginástica/fisiologia , Aptidão Física/fisiologia , Rádio (Anatomia)/anatomia & histologia , Rádio (Anatomia)/crescimento & desenvolvimento , Ulna/anatomia & histologia , Ulna/crescimento & desenvolvimento , Desenvolvimento Ósseo/fisiologia , Criança , Feminino , Humanos , Radiografia , Rádio (Anatomia)/diagnóstico por imagem , Ulna/diagnóstico por imagem
7.
Osteoporos Int ; 22(2): 489-98, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20544178

RESUMO

UNLABELLED: A randomised controlled trial was used in assessing the impact of 6 months of daily calcium and vitamin-D supplementation on trabecular and cortical bone acquisition at distal tibial and radial sites using peripheral quantitative computed tomography (pQCT). Daily supplementation was associated with increased bone density and bone strength at the distal tibia and radius. INTRODUCTION: pQCT has not been used to assess bone responses to calcium and vitamin-D supplementation on peripubertal children. This randomised controlled trial aimed to assess the impact of a 6-month daily calcium and vitamin-D supplementation on trabecular and cortical bone acquisition at distal tibial and radial sites using pQCT. METHODS: Twenty pairs of peripubertal female identical twins, aged 9 to 13 years, were randomly assigned to receive either 800 mg of calcium and 400 IU of vitamin D3, or a matched placebo. Bone structural properties at the distal tibia and distal radius were acquired at baseline and 6 months. RESULTS: The calcium-supplemented group showed greater gains in trabecular density, trabecular area and strength strain index at the 4% of distal tibial and radial sites compared with the placebo group (p=0.001). Greater gains in cortical area at the 38% and 66% of tibial sites were also found in twins receiving the calcium supplement (p=0.001). CONCLUSIONS: Daily supplementation for a period of 6 months was associated with increased trabecular area, trabecular density and strength strain index at the ultra-distal tibia and radius and increased cortical area at tibial mid-shaft.


Assuntos
Conservadores da Densidade Óssea/farmacologia , Densidade Óssea/efeitos dos fármacos , Cálcio da Dieta/farmacologia , Colecalciferol/farmacologia , Rádio (Anatomia)/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Adolescente , Cálcio da Dieta/administração & dosagem , Criança , Colecalciferol/administração & dosagem , Suplementos Nutricionais , Feminino , Humanos , Imageamento Tridimensional , Rádio (Anatomia)/fisiologia , Tíbia/fisiologia , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento , Gêmeos Monozigóticos
8.
Ann Hum Biol ; 36(6): 705-16, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19919505

RESUMO

BACKGROUND/AIM: The study investigated the relationship between indices of adiposity measured by peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA) in pre-pubertal children. SUBJECTS AND METHODS: DXA-derived per cent body fat (%BF) was measured in 284 boys and 288 girls, aged 7-10 years. Cross-sections of the forearm (n=427) and lower leg (n=560) were obtained by pQCT to measure total cross-sectional area of the limb (Total CSA), Muscle CSA, Fat CSA, %Fat CSA (Fat CSA/Total CSAx100) and muscle density. RESULTS: Peripheral QCT-derived %Fat CSA in the forearm and lower leg correlated strongly with DXA-derived %BF (r=0.83-0.89, p<0.01) in both boys and girls. However, forearm and lower leg %Fat CSA were higher than whole body %BF by 5% and 10%, respectively. A better prediction of whole-body %BF was achieved by including %Fat CSA, muscle density and height into a hierarchical regression model. Using sex-specific regression equations, 87.7% of the boys and 83.7% of the girls had a predicted %BF within 3% units of the %BF obtained by DXA. CONCLUSION: In pre-pubertal children, pQCT measures of adiposity are strongly associated with whole-body per cent body fat. This reproducible method could be an alternative technique to estimate body composition in this population.


Assuntos
Absorciometria de Fóton , Adiposidade/fisiologia , Tomografia Computadorizada por Raios X , Índice de Massa Corporal , Feminino , Mãos/diagnóstico por imagem , Humanos , Perna (Membro)/diagnóstico por imagem , Masculino , Puberdade/fisiologia , Análise de Regressão
9.
J Sci Med Sport ; 11(1): 58-65, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16949869

RESUMO

The purpose of this review is to highlight differences in thermoregulatory responses during activity of children and adolescents compared with adults. Some differences are due to movement inefficiency and physical size such as body surface area to body mass ratio, and body composition. Identified physiological differences in sweat rates appear to alter with maturation, at least in boys, but the research remains incomplete. A number of findings from hydration studies with young people exercising in the heat are also discussed. The research on clothing is adult-based, but key concepts from this research also apply to children. The final section addresses the limited research on acclimatization of children to hot conditions. Specific recommendations for children who are active in the heat conclude this review.


Assuntos
Exercício Físico/fisiologia , Transtornos de Estresse por Calor/prevenção & controle , Gestão da Segurança/métodos , Adolescente , Regulação da Temperatura Corporal/fisiologia , Criança , Feminino , Humanos , Masculino
10.
Int J Obes (Lond) ; 31(4): 630-6, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17160087

RESUMO

OBJECTIVES: To reduce gain in body mass index (BMI) in overweight/mildly obese children in the primary care setting. DESIGN: Randomized controlled trial (RCT) nested within a baseline cross-sectional BMI survey. SETTING: Twenty nine general practices, Melbourne, Australia. PARTICIPANTS: (1) BMI survey: 2112 children visiting their general practitioner (GP) April-December 2002; (2) RCT: individually randomized overweight/mildly obese (BMI z-score <3.0) children aged 5 years 0 months-9 years 11 months (82 intervention, 81 control). INTERVENTION: Four standard GP consultations over 12 weeks, targeting change in nutrition, physical activity and sedentary behaviour, supported by purpose-designed family materials. MAIN OUTCOME MEASURES: Primary: BMI at 9 and 15 months post-randomization. Secondary: Parent-reported child nutrition, physical activity and health status; child-reported health status, body satisfaction and appearance/self-worth. RESULTS: Attrition was 10%. The adjusted mean difference (intervention-control) in BMI was -0.2 kg/m(2) (95% CI: -0.6 to 0.1; P=0.25) at 9 months and -0.0 kg/m(2) (95% CI: -0.5 to 0.5; P=1.00) at 15 months. There was a relative improvement in nutrition scores in the intervention arm at both 9 and 15 months. There was weak evidence of an increase in daily physical activity in the intervention arm. Health status and body image were similar in the trial arms. CONCLUSIONS: This intervention did not result in a sustained BMI reduction, despite the improvement in parent-reported nutrition. Brief individualized solution-focused approaches may not be an effective approach to childhood overweight. Alternatively, this intervention may not have been intensive enough or the GP training may have been insufficient; however, increasing either would have significant cost and resource implications at a population level.


Assuntos
Medicina de Família e Comunidade/métodos , Sobrepeso , Imagem Corporal , Índice de Massa Corporal , Criança , Pré-Escolar , Estudos Transversais , Dieta , Exercício Físico/fisiologia , Medicina de Família e Comunidade/economia , Feminino , Custos de Cuidados de Saúde , Nível de Saúde , Humanos , Estilo de Vida , Masculino , Estado Nutricional , Obesidade/psicologia , Obesidade/terapia , Autoimagem
11.
Cochrane Database Syst Rev ; (3): CD002968, 2006 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-16855995

RESUMO

BACKGROUND: Exercise is generally recommended for people with type 2 diabetes mellitus. However, some studies evaluate an exercise intervention including diet or behaviour modification or both, and the effects of diet and exercise are not differentiated. Some exercise studies involve low participant numbers, lacking power to show significant differences which may appear in larger trials. OBJECTIVES: To assess the effects of exercise in type 2 diabetes mellitus. SEARCH STRATEGY: Trials were identified through the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and manual searches of bibliographies. Date of last search was March 3, 2005. SELECTION CRITERIA: All randomised controlled trials comparing any type of well-documented aerobic, fitness or progressive resistance training exercise with no exercise in people with type 2 diabetes mellitus. DATA COLLECTION AND ANALYSIS: Two authors independently selected trials, assessed trial quality and extracted data. Study authors were contacted for additional information. Any information on adverse effects was collected from the trials. MAIN RESULTS: Fourteen randomised controlled trials comparing exercise against no exercise in type 2 diabetes were identified involving 377 participants. Trials ranged from eight weeks to twelve months duration. Compared with the control, the exercise intervention significantly improved glycaemic control as indicated by a decrease in glycated haemoglobin levels of 0.6% (-0.6 % HbA(1c), 95% confidence interval (CI) -0.9 to -0.3; P < 0.05). This result is both statistically and clinically significant. There was no significant difference between groups in whole body mass, probably due to an increase in fat free mass (muscle) with exercise, as reported in one trial (6.3 kg, 95% CI 0.0 to 12.6). There was a reduction in visceral adipose tissue with exercise (-45.5 cm(2), 95% CI -63.8 to -27.3), and subcutaneous adipose tissue also decreased. No study reported adverse effects in the exercise group or diabetic complications. The exercise intervention significantly increased insulin response (131 AUC, 95% CI 20 to 242) (one trial), and decreased plasma triglycerides (-0.25 mmol/L, 95% CI -0.48 to -0.02). No significant difference was found between groups in quality of life (one trial), plasma cholesterol or blood pressure. AUTHORS' CONCLUSIONS: The meta-analysis shows that exercise significantly improves glycaemic control and reduces visceral adipose tissue and plasma triglycerides, but not plasma cholesterol, in people with type 2 diabetes, even without weight loss.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/terapia , Exercício Físico/fisiologia , Hemoglobinas Glicadas/metabolismo , Glicemia/metabolismo , Índice de Massa Corporal , Feminino , Humanos , Masculino , Obesidade/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Gordura Subcutânea/patologia , Redução de Peso
12.
J Sci Med Sport ; 9(4): 334-41, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16844411

RESUMO

Descriptive data on game movement demands of contemporary players in the Australian National Soccer League (NSL, now the A League) are lacking. The purpose of this study was to profile movement demands of NSL games and specifically analyse distance covered, time in various speed categories (e.g., walking, jogging, striding, etc.), number of sprint speed efforts and overall mean player speed. Video tapes of 45 players from the 2002 to 2003 NSL season were analysed for whole- and half-game movement patterns and game statistics using Trak Performance software. Bivariate and ANOVA statistics were used for between game halves and positional comparisons. Results showed no changes to the frequency and speed of high intensity demands in both halves of the game. However, a 14% slower overall speed in the second half of the game when compared with the first half was attributed to fewer observations of the low intensity movements (9.0% less walking and 12.4% less jogging) and more stationary periods. Engagement in game events such as kicking and passing was also 11.2% less frequent in the second versus first half of games. Position-specific results of higher movement speeds of midfield players (7.2kmh(-1)), compared with defenders (6.1kmh(-1)), agree with previous results from international professional leagues. The results provide position-specific directions for future conditioning drills and benchmark fitness requirements in high level soccer players. The results also highlight the challenge to ensure consistency of second-half performances for elite level soccer players in Australia.


Assuntos
Movimento/fisiologia , Futebol/fisiologia , Adulto , Análise de Variância , Antropometria , Austrália , Fenômenos Biomecânicos , Humanos , Corrida Moderada/fisiologia , Masculino , Estudos de Tempo e Movimento , Gravação em Vídeo , Caminhada/fisiologia
13.
J Sci Med Sport ; 9(4): 277-87, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16844415

RESUMO

Entrepreneurial marketing of sport increases demands on sport development officers to identify talented individuals for specialist development at the youngest possible age. Talent identification results in the streamlining of resources to produce optimal returns from a sports investment. However, the process of talent identification for team sports is complex and success prediction is imperfect. The aim of this review is to describe existing practices in physiological tests used for talent identification in team sports and discuss the impact of maturity-related differences on the long term outcomes particularly for male participants. Maturation is a major confounding variable in talent identification during adolescence. A myriad of hormonal changes during puberty results in physical and physiological characteristics important for sporting performance. Significant changes during puberty make the prediction of adult performance difficult from adolescent data. Furthermore, for talent identification programs to succeed, valid and reliable testing procedures must be accepted and implemented in a range of performance-related categories. Limited success in scientifically based talent identification is evident in a range of team sports. Genetic advances challenge the ethics of talent identification in adolescent sport. However, the environment remains a significant component of success prediction in sport. Considerations for supporting talented young male athletes are discussed.


Assuntos
Desenvolvimento do Adolescente/fisiologia , Aptidão , Destreza Motora/fisiologia , Esportes/fisiologia , Logro , Adolescente , Antropometria , Humanos , Masculino , Educação Física e Treinamento , Projetos de Pesquisa
14.
J Sci Med Sport ; 9(3): 221-30, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16697702

RESUMO

Bone adaptations to loading extend beyond mineral accrual to geometric markers of bone strength. Available technology and regional differences in cortical bone dictate how bone strength is reported. Examination of bone strength at two differentially-loaded skeletal sites using hip structure analysis (HSA) and bone strength index (BSI) is under-explored in adolescent sporting populations. The purpose of this study was to compare HSA at the femoral neck and BSI at the distal tibia in adolescent middle-distance runners and age- and gender-matched controls. Four groups of 20 adolescents aged 14-18 years were composed of male and female middle-distance runners, and male and female controls. Distal tibial BSI was calculated using data from dual energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI). Calculations for femoral neck strength were acquired from DXA-derived HSA software. Female athletes displayed greater distal tibial BSI than controls t(38)=3.4, p=0.002, but femoral neck bone measures did not differ. In males, no group differences were found at either the distal tibia or femoral neck. In conclusion, exposure to similar high training loads may advantage female adolescent athletes more than male adolescent athletes compared with less active peers in bone strength at the distal tibia.


Assuntos
Fêmur/fisiologia , Corrida/fisiologia , Tíbia/fisiologia , Suporte de Carga/fisiologia , Absorciometria de Fóton , Adaptação Fisiológica , Adolescente , Composição Corporal/fisiologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Fatores Sexuais
16.
J Sci Med Sport ; 9(1-2): 40-5, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16563860

RESUMO

We challenge the tradition of fitness testing in schools on the basis of purpose, procedures and outcomes. A number of assumptions about validity of selected tests are raised. The need to be able to track fitness through childhood into adulthood is challenged with limited scientific evidence of longitudinal tracking. Supporters of wide-scale fitness testing of children in schools include researchers whose intention is to promote public health awareness and policy. But a variety of confounding factors can affect field-based testing and lower the confidence in intra and inter group comparisons. Confounders include variability in motivation, familiarisation, external conditions, group dynamics, self-efficacy in testing, and perceived value of testing and likely outcomes. With acknowledged limitations, a more appropriate context for fitness testing for young people who have a strong commitment to physical activity may lie more in a professionally delivered sports-specific setting rather than in large-scale school-based testing. Given the less than desirable participation in activity outside of school and the distressing prevalence of childhood overweight and obesity, it is unlikely that fitness testing experiences will provide children with much needed positive encouragement for lifelong physical activity. Alternative strategies for school-based assessment of the promotion of child health through physical activity are proposed.


Assuntos
Teste de Esforço , Aptidão Física/psicologia , Instituições Acadêmicas , Austrália , Criança , Teste de Esforço/psicologia , Teste de Esforço/normas , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Estudos Longitudinais , Motivação , Obesidade/prevenção & controle , Padrões de Referência , Reprodutibilidade dos Testes
17.
Br J Sports Med ; 39(9): 622-7; discussion 627, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16118299

RESUMO

BACKGROUND: Bone strength index (BSI) combines bone mineral and bone biomechanical properties to measure resistance to bending. This index may have greater clinical significance than the more often described markers of bone mineral content (BMC), areal density, or geometry alone and, in turn, may show a stronger relation to fracture risk. The BSI is the product of volumetric cortical bone mineral density (BMD) and cross sectional moment of inertia within a region of interest. Calculations combine dual energy x ray absorptiometry and magnetic resonance imaging technologies and provide a useful, non-invasive measure of in vivo bone strength. OBJECTIVES: (a) To compare BSI in adolescent female middle distance runners and age matched controls; (b) to examine factors predictive of BSI in adolescent girls. METHODS: Twenty adolescent female middle distance runners (mean (SD) age 16 (1.7) years, physical activity 8.9 (2.1) hours a week) and 20 female controls (age 16 (1.8) years, physical activity 2.0 (0.07) hours a week) were recruited. To calculate BSI, a region of interest representing 10% of the mid-distal tibia was analysed for dual energy x ray absorptiometry derived BMC and was combined with bone geometry and biomechanical properties obtained by magnetic resonance imaging assessments. Potential predictors of BSI were also examined. RESULTS: Independent t tests showed that BMC (p = 0.028), cortical bone volume (p = 0.002), volumetric cortical BMD (p = 0.004), cross sectional moments of inertia (p = 0.005), and BSI (p = 0.002) were higher in the distal tibia of athletes than of controls. The strongest predictor of BSI was hours of physical activity a week (R2 = 0.46). CONCLUSIONS: Athletes habitually exposed to high training loads displayed greater BSI at the distal tibia than controls. The results further confirm BSI as a significant and discerning marker in musculoskeletal health in adolescent girls engaged in high and low mechanical loading.


Assuntos
Densidade Óssea/fisiologia , Corrida/fisiologia , Resistência à Tração/fisiologia , Tíbia/fisiologia , Absorciometria de Fóton/métodos , Adolescente , Fenômenos Biomecânicos , Composição Corporal/fisiologia , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Menarca/fisiologia , Educação Física e Treinamento , Tíbia/anatomia & histologia
18.
J Sci Med Sport ; 7(3): 373-83, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15518302

RESUMO

The impact of high training volumes on musculoskeletal adaptations of male adolescents is poorly understood. We compared bone mineral content (BMC) of total body, lumbar spine and proximal femur using Dual X-ray Absorptiometry (Lunar Prodigy, GE Medical Systems, Madison WI) in elite level (n=20), male adolescent middle distance runners (mean 16.8 yrs, range 14-18 yrs) and age-matched (n=20) controls. Athletes averaged 14 hrs of physical activity per week and controls reported participating in physical activity an average of two hrs per week. Total body mass was 10.97 kg less in athletes than controls (p=0.005). Within the total body mass difference, fat tissue mass of athletes was 10.93 kg less in athletes than controls (p= 0.001). Multiple regression analysis identified total body lean mass and total body fat mass as the strongest predictors of total body BMC (R2 0.71). After adjusting for lean tissue mass per kg of body weight (p=0.07), no difference in BMC was detected. Lower limb muscle strength and macronutrient intakes were also measured but no between group differences were found. The number of weeks of training and/or competition missed through injury was not associated with total body BMC (R2=0.19) among athletes. Our results imply high training volumes in middle distance running are not detrimental to musculoskeletal health and are associated with positive body composition profiles in elite adolescent male athletes.


Assuntos
Densidade Óssea/fisiologia , Músculo Esquelético/fisiologia , Corrida/fisiologia , Adolescente , Composição Corporal/fisiologia , Índice de Massa Corporal , Cálcio da Dieta/administração & dosagem , Estudos de Casos e Controles , Estudos Transversais , Ingestão de Energia/fisiologia , Humanos , Extremidade Inferior/fisiologia , Masculino , Educação Física e Treinamento , Análise de Regressão , Tíbia/fisiologia
19.
Circulation ; 104(17): 2063-8, 2001 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-11673347

RESUMO

BACKGROUND: We have developed techniques to implant angiogenic patches onto the epicardium over regions of infarcted cardiac tissue to stimulate revascularization of the damaged tissue. These experiments used a scaffold-based 3D human dermal fibroblast culture (3DFC) as an epicardial patch. The 3DFC contains viable cells that secrete angiogenic growth factors and has previously been shown to stimulate angiogenic activity. The hypothesis tested was that a viable 3DFC cardiac patch would stimulate an angiogenic response within an area of infarcted cardiac tissue. METHODS AND RESULTS: A coronary occlusion of a branch of the left anterior descending coronary artery was performed by thermal ligation in severe combined immunodeficient mice. 3DFCs with or without viable cells were sized to the damaged area, implanted in replicate mice onto the epicardium at the site of tissue injury, and compared with animals that received infarct surgery but no implant. Fourteen and 30 days after surgery, hearts were exposed and photographed, and tissue samples were prepared for histology and cytochemistry. Fourteen and 30 days after surgery, the damaged myocardium receiving viable 3DFC exhibited a significantly greater angiogenic response (including arterioles, venules, and capillaries) than nonviable and untreated control groups. CONCLUSIONS: In this animal model, viable 3DFC stimulates angiogenesis within a region of cardiac infarction and can augment a repair response in damaged tissue. Therefore, a potential use for 3DFC is the repair of myocardial tissue damaged by infarction.


Assuntos
Fibroblastos/citologia , Infarto do Miocárdio/terapia , Revascularização Miocárdica/métodos , Neovascularização Fisiológica , Transplante de Tecidos/métodos , Animais , Arteríolas/citologia , Contagem de Células , Sobrevivência Celular , Células Cultivadas , Técnicas de Cultura/métodos , Modelos Animais de Doenças , Feminino , Sobrevivência de Enxerto , Humanos , Camundongos , Camundongos SCID , Microcirculação/citologia , Pericárdio/citologia , Pericárdio/cirurgia , Transplante Heterólogo , Resultado do Tratamento
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