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Biomedical subjects

J Lefevre

Publications and source records attributed to J Lefevre.

54 records · Page 3Linked to original sources
PubMed1982

[A clinical trial of veralipride in menopausal complaints (author's transl)].

Menopausal complaints, especially hot flushes, are common occurrences. Until now, no effective treatment was available for patients in whom estrogens are contraindicated. A trial of veralipride was carried out in ten symptomatic menopausal women (7 physiologic menopauses, 3 surgical menopauses). Symptoms included severe hot flushes, anxiety (N = 6), depression (N = 4), irritability (N = 3), and cephalalgia (N = 2). Patients were given one tablet of veralipride each day for twenty day periods. Effectiveness on hot flushes was excellent in six patients, satisfactory in two, mediocre in one, and null in one. Depression, anxiety, and, to a lesser extent, cephalalgia and irritability, were alleviated. No clinical or biological adverse side-effects were recorded.

Adult↗
PubMed1982

[Posterobasal infarction and right bundle branch block: value of computerized vectorcardiography].

The object of this study was to determine the vectocardiographic criteria of posterobasal myocardial infarction associated with right bundle branch block. Seventeen patients were examined; all had clinical and enzymatic evidence of myocardial infarction, associated with the unusual appearances of right bundle branch block with an isolated R wave in V1 and V2. The Frank X, Y, and Z axes were treated by computer to obtain a detailed octonal study of the QRS and T loops. Vectors of special interest were determined: the maximum maximorum vector and the QRS half surface vector (module, azimuth, elevation, appearance time). The octonal and total surface are of the QRS and T loops and the spatial angle of the maximal vectors of the two loops were calculated. These cases were characterised by clockwise rotation of the QRS loop in the horizontal plane. The maximal QRS vector had a decrease module (1,29 mV +/- 0,49), an azimuth greater than 20 degrees (42,8 degree +2- 20,3) an appearance time of 55,7 +/- 12,1, and an elevation which was either positive or negative depending on the presence or absence of an associated left anterior hemiblock. The half-surface vector was superimposed on the maximal vector: module (1,09 mV +/- 0,39), azimuth (45,2 degrees 23,5(and appearance time (62,0 +/- 11,7 ms). The posterior surfaces were nil or negligible (less than 1 p. 100). The T loop had a clockwise rotation in the horizontal plane and its maximal vector projected anteriorly in 8 patients. The appearances observed in these 17 cases were different to those of isolated right bundle branch block. The classical causes of anterior ORS loops could be excluded easily: right ventricular hypertrophy, Wolff-Parkinson-White syndrome, intraventricular conduction defect. The following criteria were retained in the diagnosis of posterobasal infarction associated with right bundle branch block:--principally, clockwise rotation of the QRS loop in the horizontal plane;--anterior displacement of the maximal vector with an azimuth of over 20 degrees;--disappearance of the posterior forces;--associated with the usual criteria of right bundle branch block;--clockwise rotation of the T wave loop in the horizontal plane.

Bundle-Branch Block↗
PubMed1978

Significance of pulmonary input impedance in right ventricular performance.

Right ventricular adaptation to changes in pulmonary input impedance was studied in open-chest dogs. When identical increases in pulmonary vascular resistance are imposed by two different manoeuvres (lung inflation and clamping of the left pulmonary artery), external power and pressure-time integral of the right ventricle at similar filling pressure are always greater during clamping than during inflation. Further studies demonstrate that, at equal increases in pulmonary input impedance modulus at 0 Hz, the clamping produces a greater change in the sum of the first three harmonics of impedance than the inflation (respectively +77% and -10% vs control modulus; -82% and +8% vs control phase). These impedance changes could explain the different behaviour of the right ventricle either by better matching of the ventricular internal impedance or by functional modification of the outflow tract.

Animals↗
PubMedDate not supplied

Adolescent physical performance and adult physical activity in Flemish males.

Limited information is available about the associations between adolescent fitness levels and adult physical activity. In the present study, these associations are investigated using different indicators of physical activity. It is hypothesized that both health- and performance-related fitness characteristics, observed during the adolescent period, contribute equally to the explained variance in adult physical activity levels. Subjects were 109 Flemish males followed over a period of 27 years from 13 to 40 years of age in the Leuven Longitudinal Study on Lifestyle Fitness and Health. Performance and health-related fitness characteristics were observed during the growth period and at 40 years of age. The Work Index, Leisure Time Index, and Sport Index of the Baecke questionnaire were used as indicators of physical activity together with triaxial accelerometry. Multiple regression and discriminant analyses contrasting extreme quintiles of activity groupings were used to analyse the associations. Only the Baecke Sport Index showed consistent significant associations (R2 = 0.03 to R2 = 0.23) with adolescent fitness levels observed at 13, 15, and 18 years. When upper and lower quintiles were contrasted, fitness characteristics observed at the three age levels during adolescence were significantly different for each of the three indices of the Baecke questionnaire at 40 years of age. Lowest associations (R2 = 0.09 to R2 = 0.17) were found for the Work Index, followed by the Leisure Time Index (R2 = 0.12 to R2 = 0.28) and Sport Index (R2 = 0.25 to R2 = 0.43). Highest associations were evident for the 18- to 40-year interval. Performance- and health-related fitness characteristics explain equally well the variance in physical activity indicators.

Adolescent↗
PubMedDate not supplied

Age at menarche in relation to anthropometric characteristics, competition level and boat category in elite junior rowers.

BACKGROUND: Within the context of the effects of training for sports on growth and maturation, there is very little menarcheal data for elite rowing athletes. Knowledge of the relationship of the maturational status with training level, different boat categories, and somatic features of the athletes will clarify the assumed impact of rowing training on the growth and maturational process of youngsters. AIM: The aim of this study was to determine the age at menarche in world top junior rowing athletes and to investigate its relationship with anthropometric characteristics, and competition level, rowing style and boat category. SUBJECTS AND METHODS: The sample consisted of 212 female junior rowers, with a mean chronological age of 17.6 +/- 0.8 years, all participants at the 1997 FISA World Junior Rowing Championships. Anthropometric dimensions, somatotype and body composition characteristics were measured, and age at menarche and training data were retrospectively obtained by questionnaires. RESULTS: Results revealed that the mean age at menarche of the total group of rowers was 12.8 +/- 1.2 years and did not differ from a non-athletic reference population. Rowers who started their rowing training before menarche (n = 78) showed a significant (p </= 0.01) later age at menarche compared with rowers who started their training after menarche (n = 134), with mean ages of 13.4 and 12.4 years, respectively. No significant relationship between the age at menarche and physical and body composition characteristics could be demonstrated, with r varying between -0.11 and 0.11. Furthermore, no significant differences in ages at menarche between competition levels (finalists versus non-finalists/medallists versus non-medallists) and between the different boat categories could be observed. CONCLUSIONS: Based on the results of this study, there is no direct evidence to state that intensive rowing training has a negative influence on the maturation status of junior female athletes.

Adolescent↗
PubMedDate not supplied

Skeletal maturity and socio-economic status in Portuguese children and youths: the Madeira growth study.

BACKGROUND: Skeletal maturity is used to evaluate biological maturity status. Information about the association between socio-economic status (SES) and skeletal maturity is limited in Portugal. AIMS: The aim of this study is to document the skeletal maturity of youths in Madeira and to evaluate variation in maturity associated with SES. SUBJECTS AND METHODS: The study involved 507 subjects (256 boys and 251 girls) from the Madeira Growth Study, a mixed-longitudinal study of five cohorts (8, 10, 12, 14 and 16 years of age) followed at yearly intervals over 3 years (1996-1998). A total of 1493 observations were made. Skeletal age was estimated from radiographs of the hand and wrist using the Tanner-Whitehouse 2 method (TW2). Social class rankings were based on method. Five social rankings were subsequently grouped into three SES categories: high, average and low. RESULTS: Median for the radius, ulna and short finger bones (RUS scores) in the total sample of boys and girls increased curvilinearly across age whereas median for the 7 (without pisiform) carpal bones (Carpal scores) increased almost linearly. The 20-bone maturity scores demonstrated distinctive trends by gender: the medians for boys increased almost linearly while the medians for girls increased curvilinearly. SES differences were minimal. Only among children aged 10-11 years were high SES boys and girls advanced in skeletal maturity. Madeira adolescents were advanced in skeletal maturity compared with Belgian reference values. CONCLUSION: The data suggests population variation in TW2 estimates of skeletal maturation. Skeletal maturity was not related to SES in youths from Madeira.

Adolescent↗
PubMedDate not supplied

Age at menarche in Flemish girls: current status and secular change in the 20th century.

The age at menarche in a national sample of 4894 Flemish schoolgirls was surveyed in 1979-1980. The probit estimate of the mean age at menarche was 13.20 +/- 0.02 years (SD = 1.25 years). This estimate falls well within the range of reported ages at menarche for girls in northwestern Europe, but is slightly later than those for French-speaking girls in Belgium and in France. Status quo secular data for the 20th century indicate a decline in estimated mean ages at menarche of Flemish girls from about 14.3 years before World War II to 13.6 and 13.2 years, respectively, among girls born just before and during the war. Subsequently, mean ages at menarche of Flemish girls are fairly stable between 13.0 and 13.2 years. These secular changes are of the same magnitude as those observed in other European countries.

Adolescent↗
PubMedDate not supplied

Skeletal maturity in Belgian youths assessed by the Tanner-Whitehouse method (TW2).

Reference data for skeletal maturity (TW2 method) of the hand and wrist are provided for large representative samples of Belgian boys and girls. The sample of Belgian boys consisted of 21,174 boys aged 12 to 20 years studied in a nationwide cross-sectional and longitudinal study on the physical fitness of secondary schoolboys (1969-1974). The girls' sample consisted of 9698 6-19-year-old Flemish girls studied cross-sectionally (1979-1980). Both samples were multi-stage stratified cluster samples of entire school classes. All skeletal maturity assessments of the boys were made by the same observer (GB). His estimations agreed quite closely with those of the originators of the method. The skeletal age assessments of the girls were made by two observers trained by GB. Both observers showed high intraobserver reliability after training, and during the assessments. Moreover their ratings compared favourably with those of GB and the originators of the method. Smoothed percentile curves of the maturity scores (TW2-20 bone, RUS and CARP scores) were calculated by means of cubic splines using a stepwise regression procedure for the selection of suitable knots. In the boys, the TW2 scores (20 bone and RUS) increase linearly between 12 and 14.5 years of age, slow down for a while, and then increase again, while the CARP scores increase linearly between 12 and 15 years of age. In girls, the 20-bone maturity scores increase nearly linearly from 6 through 9.5 years of age, accelerate until 11.0 years followed by a smaller increase; RUS scores increase curvilinearly from 6 years of age onwards; and Carp scores increase almost linearly between 6.0 and 12.5 years of age. Belgian boys are advanced in RUS scores but are delayed for the carpal bones as compared with the British standards. The Belgian girls show advancement for both scales as compared with the British reference data. The skeletal maturation of youths from several other continental European countries corresponds more closely with the Belgian than with the British data. The reference data presented herein most probably provide suitable standards for youths of West-European countries.

Adolescent↗
PubMedDate not supplied

Motor performance during adolescence and age thirty as related to age at peak height velocity.

Relationships between motor performance, as measured by various fitness tests, and age at peak height velocity have been studied in a sample of 173 Flemish boys, measured yearly between +/- 13 and +/- 18 years and again as adults at 30 years of age. In addition to correlation studies, comparisons were made between boys with an early, average and late age at peak height velocity. To summarize the successive measurements during adolescence, a longitudinal principal component analysis was carried out. The first component can be interpreted as an average percentile level component. During adolescence, three performance tasks, namely speed of limb movement, explosive strength and static strength, are negatively related to age at peak height velocity; thus early maturers performed significantly better than late maturers. However, between late adolescence and adulthood, a cross-over of the average distance curves between 18 and 30 years of age was noted for almost all motor tasks. The late maturers not only caught up the early maturers, but there were significant differences for explosive strength and functional strength in favour of late maturers. In order to predict performance in adulthood from measures during adolescence, the following hypothesis is suggested: the best results at adulthood are obtained by those men who were already good performers during adolescence and who were late maturers, while the worst results are obtained by poor performers during adolescence who were early maturers.

Adolescent↗
PubMedDate not supplied

Maturity-associated variation in peak oxygen uptake in active adolescent boys and girls.

Maturity-associated variation in peak O2 uptake was considered in a longitudinal sample of 47 boys and 40 girls who were enrolled in sports schools. The children were followed annually from 11 to 14 years of age. O2 uptake and heart rate were measured during a maximal exercise test on a cycle ergometer. For boys, individual velocity curves were used to operationally define maturity groups: early-decreasing velocities from 11 to 14 years, n = 9; average-velocities reaching a peak and then decreasing, n = 7; and late-increasing velocities from 11 to 14 years, n = 31. The distributions of stages of genital and public hair development were consistent with early, average and late maturity status designation based on velocities of stature growth. Prospectively collected ages at menarche were used to define maturity groups in girls: early--< 12.0 years, n = 7, 10.8 +/- 0.6 years; average--12.0.12.9 years, n = 20, 12.4 +/- 0.3 years; and late-- > or = 13.0 years, n = 13, 13.5 +/- 0.4 years. Early maturing boys had a greater O2 uptake at each observation period. Early and average maturing girls did not differ in maximal O2 uptake, but both had greater O2 uptake than late maturers. When expressed per unit body mass, differences among the three maturity groups of boys were reduced and not significant. Late maturing girls tended to have greater maximal O2 uptake per unit body mass than early and average maturing girls, but the differences were not significant at all ages. However, with body mass at the first observation as the covariate in analyses of covariance, the three maturity groups of boys differed significantly in peak VO2 at each observation, while the three maturity groups of girls did not. Thus, removing the confounding effect of body mass on O2 uptake by simply dividing the measured values by mass is of limited utility.

Adolescent↗
PubMedDate not supplied

The accident-prone and overuse-prone profiles of the young athlete.

A 1 year prospective study was done to develop an accident-prone and overuse-prone profile of young athletes. A group of 185 freshman physical education students (118 males; 67 females of the same age (18.3 +/- 0.5 years) trained under the same conditions and were exposed to similar extrinsic risk factors. Using a descriptive statistical technique, an analysis of correspondence, the complex interrelation between the criterium variables (acute injuries and overuse injuries) and the predictor variables (intrinsic risk factors; physical characteristics--anthropometric data, physical fitness parameters, flexibility aspects and malalignment of the lower extremities; and psychological factors--16 personality traits) was estimated for males and females separately. Although dynamic strength seems to be an important risk factor in acute injuries, sports accidents must be seen in relation to psychological factors. However, the overuse-prone profile is mainly based on physical traits: a combination of muscle weakness, ligamentous laxity, and muscle tightness predisposes to stress injuries. In addition, these overuse effects are intensified by large body weight and length, a high explosive strength, and malalignment of the lower limbs. Nevertheless, it has to be kept in mind that psychosomatic factors play a role in how one experiences these overuse phenomena.

Accident Proneness↗
PubMedDate not supplied

Gymnast wrist: an epidemiologic survey of ulnar variance and stress changes of the radial physis in elite female gymnasts.

The ulnar variance in female gymnasts attending the World Championship Artistic Gymnastics Rotterdam 1987 was measured. There was a marked increase in the ulnar length in adult as well as immature gymnast compared with nonathletes. The changes in relative ulnar length were correlated to weight, height, and skeletal age of the athletes. In 10% of the gymnasts' wrists we noted so-called "stress-related changes" of the distal physis of the radius. Repetitive injury and compression of the wrist leads to a premature closure of the distal radial growth plate resulting in secondary ulnar overgrowth.

Adolescent↗