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1.
J Sports Sci ; 41(22): 2027-2032, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38287473

RESUMO

The scientific literature lacks consensus on classification of middle- and long-distance runners. This creates situations where the sample studied may not represent the target population and could produce misleading conclusions. Thus, we present an approach for a data-driven classification of middle- and long-distance runners according to their competition results. The best annual results of middle- and long-distance track runners participating at major (Olympics, World and European Championships) and national championships (Denmark, Sweden, Finland, Norway) were gathered for the 2012-2018 period. Overall, 1920 men's and 1808 women's performance results were gathered. The results were grouped accordingly. Quadratic discriminant analysis was applied to define the limits between the groups. Three basic categories could be proposed for classification: world class, international and national. Classification provides a realistic overview of performance standards and the number of athletes for different categories in middle- and long-distance track running in real-world settings. The performance-based classification provides data-driven and unified criteria for reporting standards on athletes' proficiency levels. It allows for more consistent reporting practices on the target population in research. In addition to scientific research, the classification could also be employed for a variety of practical purposes.


Assuntos
Resistência Física , Corrida , Masculino , Humanos , Feminino , Atletas , Consenso , Finlândia
2.
Physiol Int ; 107(4): 513-526, 2020 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-33393937

RESUMO

Irisin is a novel exercise-induced myokine that may be involved in regulating energy metabolism. We determined whether overtraining syndrome (OTS) and its biochemical markers are associated with plasma irisin levels in athletes. Seven severely overtrained athletes (OA) and 10 healthy control athletes (CA) were recruited and examined at the time of diagnosis (baseline) and after 6- and 12-months follow-up. Training volume and intensity were initially restricted but progressively increased in OA as OTS symptoms alleviated; CA continued their normal training routine. A maximal cycle ergometer test was performed with irisin analyzed before and after the test. Before the exercise test, irisin levels tended to be lower in OA than in CA at baseline (154.5 ± 28.5 vs. 171.7 ± 58.7 ng/mL). In both groups, at rest irisin levels changed only marginally during follow-up and were not affected by maximal exercise, nor were they associated with physical performance or body fat percentage. Irisin concentration at rest correlated positively with an oxidative stress marker, malondialdehyde (MDA) and negatively with an antioxidant protection marker, oxygen radical absorbance capacity (ORAC) in response to the exercise test in OA at baseline. Our findings help to clarify the possible contribution of irisin and its association with oxidative stress in the pathophysiology of OTS.


Assuntos
Atletas , Transtornos Traumáticos Cumulativos/sangue , Fibronectinas/sangue , Estresse Oxidativo , Condicionamento Físico Humano/efeitos adversos , Biomarcadores/sangue , Estudos de Casos e Controles , Transtornos Traumáticos Cumulativos/diagnóstico , Transtornos Traumáticos Cumulativos/etiologia , Transtornos Traumáticos Cumulativos/fisiopatologia , Citocinas/sangue , Humanos , Mediadores da Inflamação/sangue , Malondialdeído/sangue , Capacidade de Absorbância de Radicais de Oxigênio , Síndrome , Fatores de Tempo
3.
Scand J Med Sci Sports ; 24(2): e77-85, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24024550

RESUMO

Autonomic dysfunction decreases within-subject correlation between R-R interval length (RRi) and vagally mediated RRi variability in cardiac disease. We tested the hypothesis that overtraining syndrome (OTS) may also weaken this relationship. Nine OTS and 10 control endurance athletes underwent 24-h electrocardiogram monitoring, which was repeated in eight OTS and nine control athletes after 6 months, when two OTS athletes still had symptoms of OTS. The power of high-frequency (HF) oscillations of RRi was analyzed in 5-min epochs over the whole recording. Quadratic regression was performed between 5-min values of RRi and log-transformed (ln) HF to obtain R(2) for each recording. The relationship between RRi and HFln was higher in the OTS athletes than controls [R(2): 0.87 (90% confidence interval, CI: 0.84-0.89) vs 0.78 (90% CI: 0.72-0.84); P = 0.034; effect size = 1.22]. Large decrease in R(2) was observed in six recovered OTS athletes after 6 months follow-up [ΔR(2): -0.12 (90% CI: -0.25-0.01); P = 0.11; effect size = 1.44] with no changes in the controls. Mean values of RRi and its variability did not differ between the groups. The within-subject correlation between RRi and vagally mediated RRi variability was stronger in endurance athletes with OTS compared with controls. The present findings may improve the detection of OTS and recovery from OTS in endurance athletes.


Assuntos
Frequência Cardíaca/fisiologia , Coração/fisiopatologia , Condicionamento Físico Humano/efeitos adversos , Condicionamento Físico Humano/fisiologia , Resistência Física/fisiologia , Adolescente , Adulto , Sistema Nervoso Autônomo/fisiopatologia , Estudos de Casos e Controles , Eletrocardiografia Ambulatorial , Teste de Esforço , Feminino , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Valor Preditivo dos Testes , Esportes/fisiologia , Síndrome , Adulto Jovem
4.
Scand J Med Sci Sports ; 19(6): 871-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18980607

RESUMO

The present study examined whether activity energy expenditure related to body mass (AEE/kg) is associated with maximal aerobic fitness (VO(2max)), energy balance, and body mass index (BMI) during the 2 hardest weeks of the military basic training season (BT). An additional purpose was to study the accuracy of the pre-filled food diary energy intake. Energy expenditure (EE) with doubly labeled water, energy intake (EI), energy balance, and mis-recording was measured from 24 male conscripts with varying VO(2max). AEE/kg was calculated as (EE x 0.9-measured basal metabolic rate)/body mass. The reported EI was lower (P<0.001) than EE (15.48 MJ/day) and mis-recording of the pre-filled diary was -20%. The negative energy balance (-6+/-26%) was non-significant; however, the variation was high. The subjects with a low VO(2max), a high BMI, and a negative energy balance were vulnerable to low AEE/kg. However, in the multivariate regression analysis only BMI remained in the model, explaining 33% of the variation in AEE/kg. During wintertime BT, AEE/kg is affected by energy balance, VO(2max), and BMI. From these three factors, overweight limits high-level training the most. Furthermore, an optimal energy balance facilitates physical performance and enables high training loads to be sustained during the BT season.


Assuntos
Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Aptidão Física/fisiologia , Antropometria , Índice de Massa Corporal , Teste de Esforço , Finlândia , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Adulto Jovem
5.
Int J Sports Med ; 29(7): 552-8, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18050058

RESUMO

This study compared the autonomic responses to an active orthostatic test and Stroop Color Word Test (Stroop) as well as cognitive performance in Stroop in twelve severely overtrained (OA, 6 men and 6 women) and twelve control athletes (CA, 6 men and 6 women). RR-intervals were recorded during the orthostatic test, the Stroop, and a relaxation period succeeding the Stroop. Low frequency power during standing in the orthostatic test was lower in OA than in CA (1322 +/- 955 ms2 vs. 2262 +/- 1029 ms2, p = 0.030, respectively). During Stroop, OA had higher relative total power (50 +/- 47 % vs. 19 +/- 14 % of the individual total power during supine rest after awakening, p = 0.028, respectively) and high frequency power (38.5 +/- 9.4 % vs. 13.5 +/- 2.3 % of the individual high frequency power during supine rest after awakening, p = 0.035, respectively) than CA. In the Stroop, OA made more mistakes than CA (9.7 +/- 6.5 % vs. 5.4 +/- 3.0 %, p = 0.045). The increase in absolute total power from the Stroop to relaxation correlated negatively with the amount of mistakes in the Stroop (r = - 0.588, p = 0.003). Thus, cardiac autonomic modulation during orthostatic task and responses to cognitive task and to relaxation, as well as the cognitive performance were attenuated in severe overtraining.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Cognição/fisiologia , Frequência Cardíaca/fisiologia , Educação Física e Treinamento , Postura/fisiologia , Adulto , Estudos de Casos e Controles , Fadiga/fisiopatologia , Feminino , Humanos , Masculino
6.
Am J Physiol Heart Circ Physiol ; 293(2): H1013-22, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17400723

RESUMO

Our aim was to estimate causal relationships of genetic factors and different specific environmental factors in determination of the level of cardiac autonomic modulation, i.e., heart rate variability (HRV), in healthy male twins and male twins with chronic diseases. The subjects were 208 monozygotic (MZ, 104 healthy) and 296 dizygotic (DZ, 173 healthy) male twins. A structured interview was used to obtain data on lifetime exposures of occupational loading, regularly performed leisure-time sport activities, coffee consumption, smoking history, and chronic diseases from 12 yr of age through the present. A 5-min ECG at supine rest was recorded for the HRV analyses. In univariate statistical analyses based on genetic models with additive genetic, dominance genetic, and unique environmental effects, genetic effects accounted for 31-57% of HRV variance. In multivariate statistical analysis, body mass index, percent body fat, coffee consumption, smoking, medication, and chronic diseases were associated with different HRV variables, accounting for 1-11% of their variance. Occupational physical loading and leisure-time sport activities did not account for variation in any HRV variable. However, in the subgroup analysis of healthy and diseased twins, occupational loading explained 4% of the variability in heart periods. Otherwise, the interaction between health status and genetic effects was significant for only two HRV variables. In conclusion, genetic factors accounted for a major portion of the interindividual differences in HRV, with no remarkable effect of health status. No single behavioral determinant appeared to have a major influence on HRV. The effects of medication and diseases may mask the minimal effect of occupational loading on HRV.


Assuntos
Envelhecimento/genética , Sistema Nervoso Autônomo/fisiopatologia , Doenças em Gêmeos/genética , Variação Genética , Frequência Cardíaca/genética , Coração/inervação , Estilo de Vida , Adulto , Fatores Etários , Idoso , Sistema Nervoso Autônomo/efeitos dos fármacos , Composição Corporal/genética , Índice de Massa Corporal , Café/efeitos adversos , Estudos de Coortes , Doenças em Gêmeos/tratamento farmacológico , Doenças em Gêmeos/fisiopatologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Eletrocardiografia , Indicadores Básicos de Saúde , Coração/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Fumar/efeitos adversos , Inquéritos e Questionários , Estudos em Gêmeos como Assunto , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética
7.
Clin Physiol Funct Imaging ; 26(4): 232-4, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16836696

RESUMO

Whole-body cryotherapy (WBC) is one mode of cold therapy, during which rheumatic patients are exposed to very cold air (-110 degrees C) in minimal clothing. It is also proposed to have a bronchodilatory effect. The aim was to examine the effects of WBC on lung function in healthy humans after acute and repeated exposures. Twenty-five healthy, non-smoking subjects participated in the study. They were exposed to WBC for 2 min three times per week for 12 weeks. The peak expiratory flow rate (PEF) and forced expiratory volume in 1 s (FEV1) were measured before and after (at 2 and 30 min) the first WBC, and then similarly at 4, 8 and 12 weeks. At all time points, after 30 min of the WBC the PEF values were slightly lower compared with values before the WBC, and the reductions reached statistical significance at 1 month (5.1 +/- 1.2%), and at 3 months (3.2 +/- 1.7%). After 30 min of the first WBC, the FEV1 was significantly reduced by 2.3 +/- 0.8%, but no other changes were observed during the study. In conclusion, the WBC induced minor bronchoconstriction in healthy humans instead of proposed bronchodilatation. The WBC seems not to be harmful for lung function, but should be used with caution in susceptible individuals.


Assuntos
Crioterapia , Fenômenos Fisiológicos Respiratórios , Broncoconstrição/fisiologia , Feminino , Volume Expiratório Forçado/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Pico do Fluxo Expiratório/fisiologia , Testes de Função Respiratória/métodos , Fatores de Tempo
8.
Int J Sports Med ; 27(9): 702-8, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16586330

RESUMO

Brain 5-HT neurotransmission has been described to be down-regulated in depressed people, and also suspected to be changed in overtraining state, the consequence of long-term physical overloading and stress in athletes. We studied brain serotonin (5-HT) transporter binding i.e., 5-HT reuptake with the specific radioligand (123-I-labelled 2beta-carbomethoxy-3beta[4-iodopenyl]-nortropane, Nor-beta-CIT), and with single photon emission tomography (SPET) in severely overtrained athletes and their controls at the baseline and after a one-year recovery period. Twelve overtrained (6 women and 6 men, mean age 27 yrs, range 16 - 39 yrs) and 11 healthy (6 women, 5 men, 26 yrs, 20 - 39 yrs) athletes were examined. Overtrained athletes 1) had suffered from an unexplained decrement in physical performance and fatigue for several weeks to many months and continued to have the same symptoms even after a recovery time of weeks to months, 2) had been examined to be otherwise healthy, and 3) had a suitable training history for overtraining. Nor-beta-CIT SPET was acquired 5 min, and 3, 6, and 24 h after the injection of the radioligand. 5-HT reuptake in ml/ml in midbrain (raphe nuclei) was calculated as (midbrain - cerebellum)/cerebellum. According to two-way analysis of variance, no changes inside the groups or group differences in 5-HT reuptake were found. Male athletes had significantly higher 5-HT reuptake than female athletes at the baseline (p = 0.034). The overtrained athletes were moderately depressed, while their scores in standardized Hamilton and Montgomery-Asberg Depression Rating Scales were 16 +/- 2 (mean +/- SEM, range 8 - 29) and 17 +/- 2 (7 - 28), respectively. In the CA, the scores were 6 +/- 1 (range 2 - 18) and 6 +/- 2 (1 - 19), respectively. 5-HT reuptake did not correlate with the depression scores either in the whole group or in the OA. The finding of the present study does not support the idea of long-term changes in 5-HT neurotransmission in overtraining state, in this case serotonin reuptake in midbrain, the regulating area of brain serotonin neurotransmission. Furthermore, depression of overtrained athletes may be its own variant having no correlation with 5-HT reuptake in midbrain. Sex may have effect on chronic stress response at the brain level in athletes, which may be a confusing factor in the overtraining studies, and has to be taken into consideration in the future.


Assuntos
Encéfalo/metabolismo , Depressão/fisiopatologia , Serotonina/metabolismo , Esportes/fisiologia , Estresse Fisiológico/metabolismo , Adolescente , Adulto , Cocaína/análogos & derivados , Regulação para Baixo , Fadiga/fisiopatologia , Feminino , Humanos , Masculino , Resistência Física/fisiologia , Estudos Prospectivos , Ensaio Radioligante , Tomografia Computadorizada de Emissão de Fóton Único
9.
Int J Sports Med ; 25(2): 150-3, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14986200

RESUMO

The purpose of this report is to study serotonin reuptake of the brain in a severely overtrained athlete by using single-photon emission computed tomography (SPECT). A 26-year-old team athlete increased his training volume (by 200 %) and intensity markedly in a new high-level team. After two months, he started to feel continuous fatigue. He had tinnitus in his left ear, he felt disturbing palpitation and had pollacisuria. After four months, he started to suffer from insomnia. He still continued to play for another three months, after which he was unable to play. He could only sleep for 3 to 4 hours per night. Only minor abnormalities could be found in extensive physical and laboratory examinations. The athlete had a severe overtraining state. In the brain SPECT scans, using the specific radioligand for serotonin transporter imaging ( (123)I labelled 2beta-carbomethoxy-3beta-[4-iodophenyl]-nortropane), low activity areas were detected in the midbrain, anterior gingulus, and left frontal and temporo-occipital lobes. In a psychiatric examination, the patient was found to have signs of major depression, which he hardly recognized himself. We conclude, that that the severe overtraining state could have been related to decreased serotonin reuptake in the brain and signs of major depression.


Assuntos
Encéfalo/metabolismo , Depressão/etiologia , Serotonina/metabolismo , Distúrbios do Início e da Manutenção do Sono/etiologia , Esportes , Adulto , Encéfalo/diagnóstico por imagem , Fadiga/complicações , Humanos , Masculino , Fadiga Muscular , Resistência Física , Tomografia Computadorizada de Emissão de Fóton Único
10.
Int J Cardiol ; 89(1): 45-52, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12727004

RESUMO

Patients benefit from surgical seclusion of atrial septal defect but have excessive cardiovascular morbidity after the operation. We evaluated haemodynamics and looked for abnormalities of cardiac structures and function late after surgical seclusion of the defect. Serum N-terminal natriuretic peptide measurement and transthoracic and transoesophageal echocardiography were performed in 61 patients aged 43+/-15 years (mean+/-standard deviation) 21+/-5 years after surgery. The findings were compared with 67 control subjects. The patients had higher serum N-terminal atrial natriuretic peptide concentration than the control subjects (0.40+/-0.32 vs. 0.24+/-0.12 nmol/l, P=0.0001). Peptide levels correlated with current age (P=0.0001) and age at operation (P=0.0014), but not with age in the control subjects. In the patients, echocardiography measurements of cardiac dimensions correlated with hormone levels (atrial natriuretic peptide concentration with left atrial end-systolic diameter (P=0.042), left ventricular end-diastolic (P=0.021) and end-systolic diameter (P=0.042). There were only 10 patients (16%) without any abnormality in echocardiography. Their peptide concentration was 0.25+/-0.18 nmol/l (P=not significant compared to the control subjects). The association between increasing N-terminal atrial peptide levels and operation age together with echocardiography findings support the clinical consensus of treating atrial septal defect patients in their childhood and adolescence.


Assuntos
Ecocardiografia/métodos , Comunicação Interatrial/sangue , Comunicação Interatrial/diagnóstico por imagem , Adulto , Fator Natriurético Atrial/sangue , Estudos de Casos e Controles , Feminino , Comunicação Interatrial/cirurgia , Hemodinâmica , Humanos , Masculino , Complicações Pós-Operatórias , Análise de Regressão , Estatísticas não Paramétricas
11.
Phys Sportsmed ; 29(5): 35-50, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-20086573

RESUMO

Overtraining syndrome is a serious problem marked by decreased performance, increased fatigue, persistent muscle soreness, mood disturbances, and feeling 'burnt out' or 'stale.' The diagnosis of overtraining is usually complicated, there are no exact diagnostic criteria, and physicians must rule out other diseases before the diagnosis can be made. An orthostatic challenge shows promise as a diagnostic tool, but the subjective feelings of the patient remain one of the most reliable early warning signs. Prevention is still the best treatment, and certain subjective and objective parameters can be used by athletes and their trainers to prevent overtraining. Further studies are needed to find a reliable diagnostic test and determine if proposed aids to speed recovery will be effective.

12.
Eur J Heart Fail ; 2(2): 161-5, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10856729

RESUMO

BACKGROUND: The purpose of surgical closure of atrial septal defect (ASD) is to relieve the cardiovascular system from a haemodynamic burden. Excessive amounts of atrial peptides are released in congestive heart failure, valvular diseases and congenital heart diseases. AIMS: To examine whether patients after surgical repair of ASD have higher concentrations of N-terminal atrial natriuretic peptide (ANP-N) than age-, sex- and body mass index (BMI)-matched control subjects. METHODS: Medical history, physical examination, standard 12-lead electrocardiogram, and ANP-N concentrations were obtained in 65 adult patients operated for ASD at the age of 21+/-13 years (mean+/-standard deviation), 21+/-6 years after surgical closure of ASD. Sixty-seven healthy subjects matched for age, sex and BMI served as controls. RESULTS: In the patients serum ANP-N was higher than in the control subjects 0.41+/-0.32 nmol/l, median 0.31 nmol/l, interquartile range (IQR) 0.21-0.49 nmol/l vs. 0.24+/-0.12 nmol/l, median 0.23 nmol/l, IQR 0.17-0.29 nmol/l, (P=0.0003). Patients with concomitant diseases had higher ANP-N concentrations (0.51+/-0.39 nmol/l, median 0.34, IQR 0.26-0.73 nmol/l) than ASD patients without any history or signs of disease (0.28+/-0.16 nmol/l, median 0.27, IQR 0.17-0.40 nmol/l, P=0.01). The 'healthy' ASD patients had higher hormone concentrations than age-, sex- and BMI-matched control subjects (0.28+/-0.16 median 0.27 nmol/l, IQR 0. 17-0.40 nmol/l and 0.21+/-0.07 nmol/l, median 0.20 nmol/l, IQR 0. 15-0.27 nmol/l, P=0.01). Multiple stepwise linear regression analysis showed that age at operation was strongly associated with the post-operative ANP-N concentration (r(2)=0.25, P=0.0002). CONCLUSION: ASD patients have higher ANP-N concentrations late after surgical repair. Hormone levels correlate with age at operation. Our finding supports the clinical praxis of operating on these patients in their childhood and adolescence.


Assuntos
Fator Natriurético Atrial/sangue , Comunicação Interatrial/sangue , Adulto , Idoso , Procedimentos Cirúrgicos Cardíacos , Feminino , Comunicação Interatrial/cirurgia , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Análise de Regressão
13.
Int J Sports Med ; 21(1): 45-53, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10683099

RESUMO

We investigated heavy training- and overtraining-induced changes in heart rate and blood pressure variability during supine rest and in response to head-up tilt in female endurance athletes. Nine young female experimental athletes (ETG) increased their training volume at the intensity of 70-90% of maximal oxygen uptake (VO2max) by 125% and training volume at the intensity of < 70% of VO2max by 100% during 6-9 weeks. The corresponding increases in 6 female control athletes were 5% and 10%. The VO2max of the ETG and the control athletes did not change, but it decreased from 53.0 +/- 2.2 ml x kg(-1) x min(-1) to 50.2 +/- 2.3 ml x kg(-1) x min(-1) (mean+/-SEM, p < 0.01) in five overtrained experimental athletes. In the ETG, low-frequency power of R-R interval (RRI) variability during supine rest increased from 6 +/- 1 ms2 x 10(2) to 9 +/- 2 ms2 x 10(2) (p < 0.05). The 30/15 index (= RRI(max 30)/RRI(min 15), where RRI(max 30) denotes the longest RRI close to the 30th RRI and RRI(min 15) denotes the shortest RRI close to the 15th RRI after assuming upright position in the head-up tilt test), decreased as a result of training (analysis of variance, p = 0.05). In the ETG, changes in VO2max were related to the changes in total power of RRI variability during standing (r = 0.74, p < 0.05). Heart rate response to prolonged standing after head-up tilt was either accentuated or attenuated in the overtrained athletes as compared to the normal training state. We conclude that heavy training could increase cardiac sympathetic modulation during supine rest and attenuated biphasic baroreflex-mediated response appearing just after shifting to an upright position. Heavy-training-/overtraining-induced decrease in maximal aerobic power was related to decreased heart rate variability during standing. Physiological responses to overtraining were individual.


Assuntos
Pressão Sanguínea , Exercício Físico/fisiologia , Frequência Cardíaca , Adulto , Feminino , Humanos , Consumo de Oxigênio , Resistência Física/fisiologia , Postura , Teste da Mesa Inclinada
14.
Brain Res Dev Brain Res ; 118(1-2): 1-11, 1999 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-10611498

RESUMO

Deficiency in palmitoyl protein thioesterase (PPT) results in the rapid death of neocortical neurons in human. Very little is known about the developmental and cell-specific expression of this lysosomal enzyme. Here we show that PPT is expressed as a major 2.65 kb and a minor 1.85 kb transcript in the mouse brain. Transcript levels gradually increase between postnatal days 10 and 30. In situ hybridization analysis revealed that PPT transcripts are found widely but not homogeneously in the brain. The most intense signal was detected in the cerebral cortex (layers II, IV-V), hippocampal CA1-CA3 pyramidal cells, dentate gyrus granule cells and the hypothalamus. Immunostaining of PPT was localized in the cell soma, axons and dendrites, especially in the pyramidal and granular cells of the hippocampus, correlating well, both spatially and temporally, with the immunoreactivity of a presynaptic vesicle membrane protein, synaptophysin. In whole embryos, at embryonic day 8, the PPT mRNA expression was most apparent throughout the neuroepithelium, and from day 9 onwards it was seen in all tissues. The expression pattern of PPT suggests its general significance for the brain cells and reflects the response to maturation and growth of the neural networks. Strong PPT immunoreactivity in the axons and dentrites would imply that PPT may not be exclusively a lysosomal enzyme. A notable correlation with synaptophysin would suggest that PPT may have a role in the function of the synaptic machinery.


Assuntos
Envelhecimento/metabolismo , Animais Recém-Nascidos/metabolismo , Encéfalo/embriologia , Encéfalo/metabolismo , Feto/metabolismo , Tioléster Hidrolases/metabolismo , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Desenvolvimento Embrionário e Fetal , Feto/fisiologia , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Camundongos Endogâmicos , RNA Mensageiro/metabolismo , Valores de Referência , Tioléster Hidrolases/genética , Distribuição Tecidual
15.
Mol Genet Metab ; 67(4): 294-307, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10444340

RESUMO

The deficiency of a lysosomal enzyme, aspartylglucosaminidase, results in a lysosomal storage disorder, aspartylglucosaminuria, manifesting as progressive mental retardation. To understand tissue pathogenesis and disease progression we analyzed the developmental expression of the enzyme, especially in brain, which is the major source of the pathological symptoms. Highest mRNA levels in brain were detected during embryogenesis, the levels decreased neonatally and started to increase again from Day 7 on. In Western analyses, a defective processing of aspartylglucosaminidase was observed in brain as compared to other tissues, resulting in very low levels of the mature, active form of the enzyme. Interestingly immunohistochemical analyses of mouse brain revealed that aspartylglucosaminidase immunoreactivity closely mimicked the myelin basic protein immunostaining pattern. The only evident neuronal staining was observed in the developing Purkinje cells of the cerebellum from Days 3 to 10, reflecting well the mRNA expression. In human infant brain, the immunostaining was also present in myelinated fibers as well as in the Purkinje cells and, additionally, in the soma and extensions of other neurons. In the adult human brain neurons and oligodendrocytes displayed immunoreactivity whereas myelinated fibers were not stained. Our results of aspartylglucosaminidase immunostaining in myelinated fibers of infant brain might imply the involvement of aspartylglucosaminidase in the early myelination process. This is consistent with previous magnetic resonance imaging findings in the brains of aspartylglucosaminuria patients, revealing delayed myelination in childhood.


Assuntos
Encéfalo/enzimologia , Doenças por Armazenamento dos Lisossomos/enzimologia , Adulto , Animais , Aspartilglucosilaminase/genética , Aspartilglucosilaminase/metabolismo , Western Blotting , Encéfalo/embriologia , Encéfalo/patologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Humanos , Imuno-Histoquímica , Hibridização In Situ , Recém-Nascido , Fígado/enzimologia , Doenças por Armazenamento dos Lisossomos/etiologia , Doenças por Armazenamento dos Lisossomos/genética , Masculino , Camundongos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Gênica
16.
J Neuropathol Exp Neurol ; 57(12): 1154-63, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9862638

RESUMO

Aspartylglucosaminuria (AGU) is a recessively inherited lysosomal storage disorder caused by the deficiency of the aspartylglucosaminidase (AGA) enzyme. The hallmark of AGU is slowly progressing mental retardation but the progression of brain pathology has remained uncharacterized in humans. Here we describe the long-term follow-up of mice carrying a targeted AGU-mutation in both alleles. Immunohistochemistry, histology, electron microscopy, quantitative magnetic resonance imaging (MRI) and behavioral studies were carried out to evaluate the CNS affection of the disease during development. The lysosomal storage vacuoles of the AGA -/- mice were most evident in central brain regions where MRI also revealed signs of brain atrophy similar to that seen in the older human patients. By immunohistochemistry and MRI examinations, a subtle delay of myelination was observed in AGA -/- mice. The life span of the AGA -/- mice was not shortened. Similar to the slow clinical course observed in human patients, the AGA -/- mice have behavioral symptoms that emerge at older age. Thus, the AGU knock-out mice represent an accurate model for AGU, both histopathologically and phenotypically.


Assuntos
Aspartilglucosaminúria , Sistema Nervoso Central/patologia , Monitorização Fisiológica/métodos , Animais , Aspartilglucosilaminase/urina , Comportamento Animal/fisiologia , Humanos , Immunoblotting , Imuno-Histoquímica , Deficiência Intelectual/enzimologia , Deficiência Intelectual/patologia , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Eletrônica , Bainha de Mielina/fisiologia , Proteínas do Tecido Nervoso/metabolismo , RNA Mensageiro/análise
17.
Clin Physiol ; 18(6): 510-20, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9818156

RESUMO

We examined heavy training-induced changes in baroreflex sensitivity, plasma volume and resting heart rate and blood pressure variability in female endurance athletes. Nine athletes (experimental training group, ETG) increased intense training (70-90% VO2max) volume by 130% and low-intensity training (< 70% Vo2max) volume by 100% during 6-9 weeks, whereas the corresponding increases in six control athletes (CG) were 5% and 10% respectively. Maximal oxygen uptake (VO2max) in the ETG and CG did not change, but in five ETG athletes VO2max decreased from 53.0 +/- 2.2 (mean +/- SEM) (CI 46.8-59.2) ml kg-1 min-1 to 50.2 +/- 2.3 (43.8-56.6) ml kg-1 min-1 (P < 0.01), indicating overtraining. Baroreflex sensitivity (BRS) measured using the phenylephrine technique and blood pressure variability (BPV) did not change, but the low-frequency power of the R-R interval variability increased in the ETG (P < 0.05). The relative change in plasma volume was 7% in the ETG and 3% in the CG. The changes in BRS did not correlate with the changes in plasma volume, heart rate variability and BPV. We conclude that heavy endurance training and overtraining did not change baroreflex sensitivity or BPV but significantly increased the low-frequency power of the R-R interval variability during supine rest in female athletes as a marker of increased cardiac sympathetic modulation.


Assuntos
Barorreflexo/fisiologia , Resistência Física/fisiologia , Estresse Fisiológico , Adulto , Barorreflexo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Exercício Físico , Teste de Esforço , Feminino , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Humanos , Fenilefrina/farmacologia , Volume Plasmático/fisiologia , Decúbito Dorsal
18.
Clin J Sport Med ; 8(3): 178-86, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9762476

RESUMO

OBJECTIVE: To examine different hormonal responses to heavy endurance training and overtraining in female athletes. DESIGN: Submaximal and maximal treadmill tests, self-report mood measures, and stress hormone analyses were repeated at baseline, after 4 weeks and at the end of 6 to 9 weeks of experimental intensive training and after 4 to 6 weeks of recovery. SUBJECTS: Fifteen healthy female endurance athletes increased their intensive training volume by 130% and base training volume by 100% (ETG, n = 9) or served as controls (CG, n = 6). MAIN OUTCOME MEASURES: Maximal oxygen uptake (VO2max), mood dynamics, blood catecholamines, cortisol and testosterone at rest and after submaximal and maximal exercise, and nocturnal urine catecholamines. RESULTS: Five females from the ETG demonstrated an over-training state (OA subgroup) at the end of the training period. Their VO2max decreased (mean +/- SEM) from 53.0 +/- 2.2 ml.kg-1.min-1 (range, 46.8-59.2) to 50.2 +/- 2.3 ml.kg-1.min-1 (range, 43.8-56.6) (p < 0.01). Maximal treadmill performance expressed as oxygen demand decreased (mean +/- SEM) from 56.0 +/- 1.6 ml.kg-1.min-1 (range, 51.5-60.5) to 52.2 +/- 1.1 ml kg-1.min-1 (range, 49.1-55.3) (p < 0.01). Maximal heart rate also decreased (mean +/- SEM) from 190 +/- 1 bpm (range, 185-197) to 186 +/- 2 bpm (range, 184-193) (p < 0.05), and the athletes experienced mood disturbances. Plasma adrenaline levels at maximal and noradrenaline at submaximal work rate decreased during the last 2 to 5 training weeks (p < 0.05), and serum cortisol levels at maximal work rate decreased during the first 4 training weeks (p < 0.05) in the ETG. Plasma adrenaline at maximal work rate decreased during the first 4 training weeks (p < 0.05) in the OA subgroup. There were no changes in the CG. Individual hormonal response types to heavy training and overtraining were found. CONCLUSIONS: Hormone responses to exercise load are superior in indicating heavy training-induced stress when compared with resting hormone levels. These responses indicated decreased sympathoadrenal and/or adrenocortical activity (or exhaustion of the adrenal gland or the central nervous system). Individual hormonal profiles are needed to follow up training effects. Marked individual differences were found in training- and overtraining-induced hormonal changes.


Assuntos
Epinefrina/sangue , Hidrocortisona/sangue , Norepinefrina/sangue , Resistência Física/fisiologia , Esportes/fisiologia , Testosterona/sangue , Adulto , Teste de Esforço , Feminino , Humanos
19.
Clin Physiol ; 18(3): 215-23, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9649909

RESUMO

A series of standardized laboratory tests [10 min sitting and supine, 9 min standing, dynamic; cycle ergometer (ERG) and isometric exercise; handgrip (HG)] were performed during intra-arterial blood pressure (BP) recording in 97 healthy unmedicated men, initially classified as normotensive (NT, n = 34), borderline hypertensive (BHT, n = 29) or mildly hypertensive (HT, n = 34) by repeated office blood pressure (OBP) measurements. After testing, a 24-h intra-arterial ambulatory BP (IABP) recording was obtained while subjects performed their normal activities. Day and night periods were analysed as well as 24-h averages for systolic BP (SBP) and diastolic BP (DBP) using Pearson correlations and multiple linear regressions. In normotensive subjects, the supine SBP predicted IABP measurements best (r range 0.39-0.69, P < 0.05-0.001). In multiple regression, supine SBP explained 49% of 24-h SBP variance (F = 12.4, P = 0.001). For BHT, supine SBP was also the best predictor (r range 0.09-0.64, P NS to P < 0.001), and it explained 37% of 24-h SBP variance (F = 15.6, P = 0.0005). In HT, ERG DBP correlated best with IABP (r range 0.52-0.75, P < 0.01-0.001). ERG SBP explained 49% of 24-h SBP (F = 31.0, P = 0.0000) and ERG DBP explained 56% of 24-h DBP (F = 35.4, P = 0.0000) variance. Laboratory BP correlations were generally better with day than with night measurements. OSBP correlated moderately well with IABP in NT, and weakly in BHT and HT; ODBP instead correlated with IABP in NT and HT but not significantly in BHT. In conclusion, OBP is less closely related to IABP than laboratory BP, but even laboratory BP generally explains less than 50% of IABP variance. Stressors such as exercise are useful only in HT. For BHT, the prediction of IABP with laboratory measures was even weaker than in other groups, and thus ambulatory measurements cannot be replaced by short-duration laboratory measurements and stress tests.


Assuntos
Determinação da Pressão Arterial/métodos , Hipertensão/diagnóstico , Adulto , Antropometria , Monitorização Ambulatorial da Pressão Arterial , Ritmo Circadiano , Técnicas de Laboratório Clínico , Teste de Esforço , Força da Mão/fisiologia , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Postura , Valores de Referência , Análise de Regressão , Reprodutibilidade dos Testes
20.
Int J Sports Med ; 19(8): 532-40, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9877144

RESUMO

We investigated the effects of progressively increased training load and overtraining on resting and intrinsic heart rate (IHR) and cardiac autonomic modulation (CAM), and their relationships to performance variables. Nine athletes (ETG) increased training volume at 70-90% of maximal oxygen uptake (VO2max) by 130% (p<0.01) and training volume at <70% VO2max by 100% (p < 0.01) during 6-9 weeks. The corresponding increases in six female control athletes (CG) were 5 and 10%. Pharmacological blocking through atropine and propranolol and the Rosenblueth and Simeone model were used to calculate the sympathovagal balance index (Abal) and to measure IHR. The results were analysed using two-way analysis of variance. VO2max, IHR and Abal did not change. Resting heart rate had a tendency to decrease in the ETG and increase in the CG during the training period (interaction p < 0.01). Five ETG athletes demonstrated overtraining state (OA subgroup). Their VO2max (mean+/-SEM) decreased from 53.0+/-2.2 ml x kg(-1) x min(-1) to 50.2+/-2.3 ml x kg(-1) x min(-1) (p < 0.01), but no changes in resting HR, IHR and Abal were found. A significant correlation between the baseline values of VO2max and the parasympathetic activity index was found (r=-0.59, p < 0.05). In conclusion, progressively increased training load and overtraining did not induce significant changes in intrinsic heart rate or cardiac autonomic modulation in female endurance athletes. Resting heart rate rather decreased with heavy endurance training and overtraining. High maximal oxygen uptake was correlated with high cardiac parasympathetic modulation.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Frequência Cardíaca , Coração/inervação , Resistência Física/fisiologia , Adulto , Pressão Sanguínea , Exercício Físico/fisiologia , Teste de Esforço , Feminino , Humanos , Consumo de Oxigênio
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