Adaptations myocardiques chez l'enfant prépubère soumis à un entraînement intensif. Étude comparative entre une population de gymnastes et de nageurs

Introduction. The purpose of the present study was to investigate the cardiac structure and function in prepubertal highly-trained swimmers and gymnasts. Method. Thirty-five children (10–11 years) were investigated: nine swimmers (S), 15 gymnasts (G) and 11 as a control group (C). The swimmers and gymnasts had trained on average 10 to 12 h/wk for at least 2 years. The subjects were examined at rest by M-mode, bi-dimensional and Doppler analyses according to standard procedures recommended by the American Society of Echocardiography. The following parameters were obtained: left ventricular (LV) internal dimension at end-diastole (LVIDd) and at end-systole —posterior wall and interventricular septal thicknesses -Left ventricular mass (Lvmass) — LV shortening fraction — ejection fraction — peak velocity of early diastolic rapid inflow and of atrial contraction filling — mitral acceleration and deceleration — isovolumic relaxation time. In addition, the cardiac output was evaluated from transaortic Doppler examinations. The heart rate (Hr) was measured simultaneously with all echocardiographic examinations. Results.- The main results show that LV internal diastolic dimensions and LV mass were significantly higher in S than in the other two groups. No differences were however observed between groups regarding cardiac wall thicknesses. Moreover, all values of G were very close to those obtained by C. Both systolic and diastolic functions were normal in the three groups. Finally, the stroke volume (SV) was higher in S than in the other two groups and because of a bradycardia observed among S, the resting cardiac output was similar in the three groups. The higher LVIDd in S still persisted after correction for Hr. A low diastolic period associated with higher LVIDs can probably explain the high SV in S. Conclusion.- Our results strongly suggest that cardiac structure and function adaptations can occur in prepubertal children as a result of an intensive training program prolonged over a long-term period, only if this program is predominantly based on aerobic exercises. Whatever the kind of sport, neither LV systolic nor diastolic functions are affected by training during prepuberty. Further investigations will however be needed in order to better understand diastolic function adaptations to intensive aerobic training in children.     

Do parents who smoke underutilize health care services for their children? A cross sectional study within the longitudinal PIAMA study

Background  

A higher prevalence of respiratory symptoms and an associated increase in health care utilization among children with parents who smoke is to be expected. From previous studies however, it appears that parents who smoke may underutilize health services for their children, especially with respect to respiratory care. This study explores the validity and generalizability of the previous assumption.     

Distinguishing patterns in the dynamics of long-term medication use by Markov analysis: beyond persistence

Background  

In order to accurately distinguish gaps of varying length in drug treatment for chronic conditions from discontinuation without resuming therapy, short-term observation does not suffice. Thus, the use of inhalation corticosteroids (ICS) in the long-term, during a ten-year period is investigated. To describe medication use as a continuum, taking into account the timeliness and consistency of refilling, a Markov model is proposed.     

Trauma and Substance Use Disorders in Rural and Urban Veterans

Context: Disparities in the prevalence, morbidity, and mortality of multiple mental health conditions have been described between rural and urban populations. However, there is limited information regarding differences in exposure to trauma and trauma‐related mental health conditions in these populations. Given the number of veterans who are returning to rural communities after serving in Operation Enduring Freedom and Operation Iraqi Freedom, differences in trauma exposure are of particular relevance. Trauma exposure is related to a variety of mental health disorders including substance use disorders (SUD). Purpose: The objectives of this preliminary study were to describe lifetime military and nonmilitary trauma and to compare trauma history between rural and urban veterans in SUD treatment. Methods: Sixty adults in SUD treatment were enrolled at 3 Veterans Health Administration sites in Nebraska over a 3‐month period in 2008. Subjects completed an interview with study staff, which assessed SUD diagnoses and childhood, lifetime, and military trauma. Rural or urban status was determined by self‐report of childhood residence. Childhood trauma, lifetime trauma, and response to military trauma were compared between rural and urban veterans. Findings: Although there were no significant differences in trauma exposure between rural and urban groups, there was an association between specific types of trauma and measures typically associated with increased substance abuse severity and poorer SUD treatment outcome. Conclusion: This is the first study, to our knowledge, which compared trauma exposure between rural and urban veterans and identified an association between childhood trauma exposure and multiple SUD treatment attempts.     

The peroxisome proliferator-activated receptor alpha Leu162Val polymorphism influences the metabolic response to a dietary intervention altering fatty acid proportions in healthy men

BACKGROUND: Serum lipid responses to dietary modification are partly determined by genetic factors. OBJECTIVE: We tested whether plasma lipoprotein and lipid responsiveness to a modification in the dietary ratio of polyunsaturated to saturated fatty acids (P:S) is influenced by the peroxisome proliferator-activated receptor alpha (PPARalpha) Leu162Val polymorphism in healthy men. DESIGN: Ten carriers of the V162 allele and 10 L162 homozygotes were matched according to age and body mass index (BMI). During the protocol, all subjects followed the National Cholesterol Education Program Step I diet, but intake of saturated and polyunsaturated fatty acids was adjusted to obtain a P:S of 0.3 for the first 4-wk period (low-P:S diet) and a P:S of 1.0 for the next 4-wk period (high-P:S diet). RESULTS: At screening, the PPARalpha Leu162Val polymorphism was not associated with anthropometric indexes or plasma lipoprotein and lipid concentrations. After the high-P:S diet, a significant gene-by-diet interaction was observed for changes in plasma total cholesterol, apolipoprotein (apo) A-I, and cholesterol concentrations in small LDL particles (P 相似文献   

Hepatic cavernous hemangioma: magnetic resonance imaging. Work in progress

Using a 0.35-T superconducting magnet and spin echo imaging, we prospectively evaluated 11 patients who had proved hepatic cavernous hemangioma. Magnetic resonance (MR) identified more lesions than either contrast-enhanced CT, or ultrasonography. The MR appearance was consistent; hemangiomas were homogeneous and generally isointense at short TR and TE intervals but were hyperintense at long TR intervals and greatly hyperintense at long TR and long TE intervals. However, the MR appearance of hemangioma was not specific; 2/14 other focal hepatic masses had similar features. The calculated relaxation times (T1, T2) were not useful in lesion characterization, although the intensity ratio of hemangioma to normal liver at the TR = 2.0 sec TE = 56 msec pulse sequence was useful in diagnosis since hemangiomas always had a ratio greater than 1.4.     

Detection of fMRI activation using cortical surface mapping

A methodology for fMRI data analysis confined to the cortex, Cortical Surface Mapping (CSM), is presented. CSM retains the flexibility of the General Linear Model based estimation, but the procedures involved are adapted to operate on the cortical surface, while avoiding to resort to explicit flattening. The methodology is tested by means of simulations and application to a real fMRI protocol. The results are compared with those obtained with a standard, volume-oriented approach (SPM), and it is shown that CSM leads to local differences in sensitivity, with generally higher sensitivity for CSM in two of the three subjects studied. The discussion provided is focused on the benefits of the introduction of anatomical information in fMRI data analysis, and the relevance of CSM as a step toward this goal.