Biomedical subjects

G Beunen

Publications and source records attributed to G Beunen.

At least 37 records · Page 2Linked to original sources

PubMed1999

Acquired microcephaly after low Apgar score in Zimbabwe.

Serial head circumference measurements were made on 165 African babies born with a 5 min Apgar score of 5 or less. Measurements were taken at birth and at 4, 9, and 12 months of age. In the majority of infants the onset of microcephaly could be diagnosed as early as 4 months of age. Twenty-five of the 142 infants were microcephalic at 1 year. Neurological development was impaired in 19 of the 25 (76 per cent) microcephalic infants and in 18 of the 117 (15 per cent) normocephalic infants. Fourteen of the 16 (88 per cent) infants with severe quadriplegia developed microcephaly before the age of 4 months. A decreased rate of head growth during the first 4 months of life in African infants born with a low Apgar score correlates closely with the development of microcephaly. Infants with an acquired microcephaly have a high probability of developing neurologic impairment by the age of 1 year. Serial head circumference measurement in low Apgar score babies in developing countries is an easy, simple, and inexpensive method to detect microcephaly.

Analysis of Variance↗

PubMed1999

Ulnar variance and skeletal maturity of radius and ulna in female gymnasts.

UNLABELLED: It is has been suggested that repetitive loading on the distal end of the radius in elite gymnasts may lead to epiphyseal changes, a premature closure (union) of the radius growth plate, and ulnar overgrowth. PURPOSE: It is hypothesized that ulnar overgrowth in female gymnasts is associated with advanced maturity status and early onset of epiphyseal closure of the radius, and later maturity status and later onset of epiphyseal closure of the ulnar. METHODS: Posterior-anterior radiographs of 201 female gymnasts, participants of the 1987 World Championships Artistic Gymnastics, were used to measure ulnar overgrowth, to determine skeletal maturation of the hand and wrist with the Tanner-Whitehouse technique, and to determine the maturity status of the radius and ulna separately, particularly with regard to the onset of epiphyseal closure. To test the hypothesis, extreme quintiles for ulnar overgrowth were contrasted for skeletal maturation of the hand and wrist and for maturity stages of the radius and ulna as defined by the Tanner-Whitehouse criteria. RESULTS: Female gymnasts who demonstrate ulnar overgrowth are skeletally more advanced in maturity status of the entire hand-wrist compared with gymnasts who did not show ulnar overgrowth. There were, however, no differences between gymnasts in the extreme quintiles of ulnar overgrowth in the maturation of the radius, although gymnasts with ulnar overgrowth show more advanced maturity status of the ulna. CONCLUSIONS: Ulnar overgrowth is thus not apparently associated with advanced maturity of the distal radial epiphysis as defined in protocols for assessing skeletal maturity and does not apparently lead to premature epiphyseal closure of the distal radius.

Adolescent↗

PubMed1999

The contribution of anthropometric characteristics to performance scores in elite female gymnasts.

BACKGROUND: Aims of this study were: a) to identify anthropometric variables correlated with gymnastic performance, and b) to predict performance scores from a combination of anthropometric dimensions. METHODS EXPERIMENTAL DESIGN: correlational analysis and a stepwise multiple regression were used. SETTING: Subjects were participants at the 24th World Championships Artistic Gymnastics, Rotterdam, The Netherlands, in 1987. PARTICIPANTS: A total of 168 female gymnasts (mean age: 16.5 +/- 1.8 years) were investigated. Each gymnast participated in all events. MEASURES: An extensive battery of anthropometric dimensions was taken on each athlete. The somatotype was estimated. Skeletal maturation of the hand-wrist was assessed. Competition scores for the four individual gymnastic events (balance beam, floor exercise, vault, uneven bars) and a composite score for each gymnast were the dependent variables. RESULTS: Moderately high, significant correlations (p < 0.01) were observed between skinfolds and endomorphy, and gymnastics performance scores, r varying from -0.38 to -0.60, for biceps skinfold and the score on balance beam, and for endomorphy and the total score, respectively. The correlations suggest that gymnasts with more subcutaneous fat and higher endomorphy have lower performance scores. About 32% to 45% of the variance in gymnastic performance scores could be explained by anthropometric dimensions and/or derived variables, but endomorphy and chronological age are the most important predictors. CONCLUSIONS: There is a relatively strong relationship between several anthropometric variables and gymnastic performance in a sample of elite female gymnasts, but the associations are not sufficiently high to predict performance scores on an individual basis.

Adolescent↗

PubMed1998

Neonatal neurological examination as a predictor of neuromotor outcome at 4 months in term low-Apgar-score babies in Zimbabwe.

The predictive value of the neonatal neurological examination (NNE) adapted from Prechtl, was investigated in 139 term Zimbabwean infants born with an Apgar score of five or less at 5 min. At 4 months, seven infants had died and 13 were lost to follow-up, leaving 119 infants to undergo the Infant Motor Screen (IMS). Eighty-eight infants were diagnosed as normal, six as suspect and 25 as abnormal at screening. The sensitivity, specificity, positive predictive value and negative predictive value of the NNE were 94%, 55%, 42% and 96%, respectively. Seventeen (14%) infants had developed microcephaly at 4 months and 13 (77%) of them scored abnormal on the IMS. Twenty-three of the 48 (48%) infants who had convulsions within 48 h of birth, were diagnosed as abnormal (P < 0.0001). The NNE proved to be very sensitive in detecting neurodevelopmental abnormalities in the neonatal period and the five abnormal syndromes derived from the NNE were able to correctly identify 94% of the abnormal infants.

Adolescent↗

PubMed1998

Univariate and multivariate genetic analysis of subcutaneous fatness and fat distribution in early adolescence.

Univariate and multivariate analyses of the genetic and environmental contributions to variance in adipose tissue and adipose tissue distribution were carried out in early adolescents. Stature, weight, body mass index (BMI), and five subcutaneous skinfolds were measured at half-yearly intervals in 105 MZ and DZ twin pairs from 10 to 14 years. The most parsimonious model, which provided an adequate explanation for variation in the BMI, five skinfolds, and the T/E ratio, included additive genetic and specific environmental factors. Multivariate analyses of the genetic architecture of subcutaneous fat indicated a general skinfold genetic factor, an extremity skinfold genetic factor, and skinfold specific genetic factors. This implies that all skinfolds are under control of the same set of genes, that a different set of genes partly controls extremity skinfolds, and that other genes have a small skinfold specific impact. Environmental contributions included a general skinfold environmental factor and skinfold specific environmental factors. BMI is under control of the same set of genes as skinfolds and shows high genetic correlations with trunk skinfolds, which implies that nearly the same genes may influence trunk skinfolds and the BMI. All models were fairly consistent across the age range.

Adipose Tissue↗

PubMed1998

Neurological status in severely jaundiced Zimbabwean neonates.

Neurological status was studied in 50 jaundiced infants with a total serum bilirubin of > 400 mumol/l (23.4 mg/dl). Infants were assessed in the neonatal period with the Neonatal Neurological Examination and 4 months of age with the Infant Motor Screen. Twenty-six (52 per cent) infants were premature. Analysis of variance did not show a significant difference between gestational age, birth weight, and maximum total serum bilirubin or between gestational age, birth weight, and neurological optimality score. Based on the presence of abnormal neurological syndromes the infants were classified as normal (n = 27), suspect (n = 11), or abnormal (n = 12). Serum bilirubin levels were higher (p < 0.0001) and the neonatal neurological examination scores lower (p < 0.0001) in the seven (14 per cent) infants who received an exchange transfusion. In the transfused group four out of seven infants and in the non-transfused group seven out of 43 infants were classified as abnormal (p < 0.03). The Neonatal Neurological Examination was shown to be sensitive in detecting neurodevelopmental abnormalities in the neonatal period, with a sensitivity of 83 per cent, specificity of 88 per cent, positive predictive value of 62 per cent, and negative predictive value of 96 per cent.

Analysis of Variance↗

PubMed1998

The predictive value of developmental testing of extremely jaundiced African infants.

The predictive value of the Neonatal Neurological Examination (NNE) adapted from Prechtl (1977) and the Infant Motor Screen (IMS) from Nickel (1989) at 4 months was studied in severely jaundiced infants in Zimbabwe. Fifty infants were examined with the NNE, 41 with the IMS and 43 with the Bayley Scales of Infant Development (BSID) (Bayley 1969). Five infants had choreoathetosis and six had a motor delay at age 1 year. The NNE and IMS proved to be sensitive instruments particularly when two infants who became malnourished after the neonatal period were excluded. Logistic regression was used to investigate the relation between the BSID and five selected predictors from the NNE. This resulted in a correct classification of 93%. By using only the predictors acoustic blink and traction response, 80% of the infants were correctly classified but the number of false negatives was reduced from three to one.

Black People↗

PubMed1997

Extreme hyperbilirubinaemia in Zimbabwean neonates: neurodevelopmental outcome at 4 months.

UNLABELLED: As part of a prospective study of severely jaundiced Zimbabwean infants, the relationship between maximum total serum bilirubin (TSB) concentration in the neonatal period and neurodevelopmental outcome at the corrected age of 4 months was studied. Fifty infants with a TSB of > 400 micromol/l (23.4 mg/dl) were enrolled and screened with a neonatal neurological examination (NNE). The cause of jaundice was low birth weight in 22 (44%), ABO incompatability in 8 (16%), sepsis in 8 (16%) and congenital syphilis (6%) in 3 infants. In 9 infants a cause could not be determined. At 4 months, 2 infants had died and 3 were lost to follow up, leaving 45 infants for the infant motor screen (IMS) at 4 months of age. Mean TSB in the neonatal period was 485 micromol/l (28.2 mg/dl), and 7 infants received an exchange transfusion. Mean TSB of the infants with an exchange transfusion was 637 micromol/l (37.2 mg/dl) (range 429-865 micromol/l (25-50.3 mg/dl)) and of the infants without transfusion 459 micromol/l (26.8 mg/dl) (range 400 740 micromol/l (23.4-43 mg/dl)) (P < 0.0001). The TSB was not associated with birth weight, gestational age, gender or head circumference of the baby. On the IMS, 6 of 45 (13.3%) infants scored abnormal, 6 (13.3%) suspect and 33 (73%) scored normal. Three of the six (50%) remaining infants who received an exchange transfusion scored abnormal on the IMS while only 3 of the 39 (8%) infants without exchange transfusion were abnormal. CONCLUSION: More than 25% of infants with a TSB of > 400 micromol/l (23.4 mg/dl) scored abnormal or suspect at 4 months of age and half of these infants already showed irreversible neurological symptoms. All infants who scored abnormal or suspect on the IMS with bilirubin levels between 400 and 500 micromol/l (23.4 and 29.2 mg/dl) had haemolytic disease or were premature.

Bilirubin↗

PubMed1997

Neurological findings in neonates with low Apgar in Zimbabwe.

OBJECTIVES: Document neurological condition of African neonates with a low apgar score. SETTING: Mpilo Hospital, Bulawayo, Zimbabwe. SUBJECTS: 165 babies with an Apgar score of 5 or less at 5 min. METHODS: Neurological examination at term age according to Prechtl. Babies were classified as normal, suspect or abnormal and compared with two reference groups, one from Groningen, the Netherlands and one from Grenada in the Caribbean. RESULTS: A higher number of Zimbabwean babies were delivered by Caesarean section compared to the Groningen group (P < 0.001). Babies delivered by vacuum extraction scored significantly lower compared to babies delivered by Caesarean section (P < 0.003). Twenty abnormal signs derived from the neonatal neurological examination proved to be predictive on the total optimality score (P < 0.001). The number of infants who were classified as abnormal was higher in the Zimbabwean population (P < 0.01). CONCLUSION: The selected abnormal signs derived from the neonatal neurological examination proved to be highly predictive on the neurological condition. The neonatal morbidity in Zimbabwean neonates with a low Apgar score was higher when compared with two reference groups from Groningen and Grenada.

Adolescent↗

PubMed1997

Development and tracking in fitness components: Leuven longtudinal study on lifestyle, fitness and health.

In the Leuven Growth Study of Belgian Boys the growth and physical performance of Belgian boys followed longitudinally between 12 and 19 years were studied. Subsequently, a subsample (n = 240) of Flemish-speaking males were reexamined at 30 and 35 years. A first question relates to the individual growth patterns in a variety of physical fitness characteristics. The three strength tests (static, functional, explosive) show curves that are qualitatively similar to those for height and weight. Their adolescent spurts occur after the height spurt. Flexibility and the two speed tests appear to reach maximum velocities prior to the height and weight spurts. Longitudinal principal component analysis was applied to the study of growth patterns of several somatic and motor characteristics. The results for height show three components sufficient to provide an adequate representation of the original information. The first component characterizes the general position of an individual growth curve. Components 2 and 3 reflect fluctuation in percentile level during the age period studied and can be conceived as indices of stability and are related to age at peak height velocity (APHV) and peak height velocity (PHV), respectively. Relationships between somatic characteristics, physical performance, and APHV 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. The sample was divided into three contrasting maturity categories based on the APHV. There are consistent differences among boys of contrasting maturity status during adolescence in body weight, skeletal lengths and breadths, circumferences, and skinfolds on the trunk. There are no differences in skinfolds on the extremities. None of the differences in somatic dimensions and ratios among the three contrasting maturity groups are significant at 30 years of age except those for subscapular skinfold and the trunk/extremity skinfold ratio. During adolescence, speed of limb movement, explosive strength and static strength are negatively related to APHV; thus, early maturers performed better than late maturers. However, between late adolescence and adulthood (30 years), the late maturers not only caught up to the early maturers, but there were significant differences for explosive strength and functional strength in favor of late maturers. Finally, age-specific tracking, using inter-age correlations, of adult health- and performance-related fitness scores were investigated. In addition, the independent contribution of adolescent physical characteristics to the explanation of adult fitness scores was also studied. Tracking between age 13 and age 30 years was moderately high (46% of variance explained) for flexibility, low to moderate (between 19% and 27% of variance explained) for the other fitness parameters and low for pulse recovery and static strength (7% to 11% of variance explained). Between age 18 and age 30 years the tracking was high for flexibility, moderately high for explosive and static strength, and moderate for the other fitness parameters except for pulse recovery. The amount of variance of adult fitness levels explained increased significantly when other characteristics observed during adolescence entered the regressions or discriminant functions.

Adolescent↗

PubMed1997

Prospective and retrospective longitudinal studies of the growth, maturation, and fitness of Polish youth active in sport.

Results of three longitudinal studies of the growth, maturation and fitness of youth active in sport are summarized. Data include size attained and growth rates for height and body mass, secondary sex characteristics, skeletal age, age at peak height velocity, and two indicators of fitness, peak O2 uptake and power output at a heart rate of 170 bpm (PWC 170). The data for active youth are compared to local reference data and where appropriate to data from other European longitudinal studies. Allowing for variation in methodology and sampling, regular training in sport during puberty and the adolescent spurt does not influence size attained, growth rate, and the timing and progression of somatic, sexual and skeletal maturation in boys and girls. Active and nonactive boys and girls, respectively, do not differ significantly in the mean age at maximum growth in power output at a heart rate of 170 bpm. Boys active in sport, however, have a greater maximal gain in submaximal power output than nonactive boys. Analysis of ontogenetic allometry of peak oxygen uptake and stature and body mass indicate variation between individuals, and between boys of contrasting maturity status.

Adolescent↗

PubMed1997

Neurodevelopmental outcome in babies with a low Apgar score from Zimbabwe.

The early identification of neurological dysfunction in the neonatal period, the predictive value of single items of the neonatal neurological examination (NNE) adapted from Prechtl and the developmental outcome at 1 year of age in infants with a low Apgar score in Zimbabwe were studied. One hundred and sixty-five infants were examined with the NNE and 142 with the Bayley Scale of Infant Development (BSID) at 1 year of age. Twenty-three infants had cerebral palsy, ten had a motor delay or developmental delay, and four were mentally retarded. The NNE proved to be a sensitive instrument for detecting neurodevelopmental abnormality. Logistic regression analysis was used to investigate the relationship between the BSID and nine selected predictors from the NNE. This resulted in a correct classification of 94%. However, the number of false negatives was high. By using only the variability of movements and fixation as predictors the number of false negatives was reduced to one.

Apgar Score↗

PubMed1997

Gender-specific regional changes in genetic structure of muscularity in early adolescence.

Genetic and environmental influences on muscle circumference measurements of the extremities were estimated in 105 pairs of twins between 10 and 14 yr of age. Four circumferences, extended upper arm (EAC), forearm (FC), thigh (TC), and calf (CC), were measured. Univariate model fitting revealed that the largest part (87-95%) of the variance for all circumferences at most ages was explained by additive genetic factors. Sex differences were observed for some age categories. Multivariate analyses showed a different pattern evolving according to age and gender. In boys from 10 to 12 yr of age, one general genetic factor influenced all four circumferences. With increasing age, an arm-leg model emerged, one genetic factor influencing the arm and another genetic factor the leg circumferences. In young girls one genetic factor loaded on the proximal (EAC, TC) and another on the distal (FC, CC) circumferences. With subjects at age 14 yr, an arm-leg model was observed. High genetic correlations indicated that genetic factors related to EAC, FC, TC, and CC did not act independently. The age-and gender-specific changes in the genetic structure suggest pubertal influences. This study shows that muscle circumferences are highly heritable characteristics and are therefore a promising starting point at which to locate their genes. Gene mapping could validate the gender-specific change of the genetic structure with age and region.

Adolescent↗

PubMed1996

Birth weight and its relationship to size attained and relative fat distribution at 7 to 12 years of age.

The relationship between birth weight and relative subcutaneous fat distribution at school age was considered in 131 boys and 106 girls 7 to 12 years of age. Relative fat distribution at school age was estimated with the ratio of the subscapular to triceps skinfolds (S/T) for the total sample, and with the ratio of the sum of two trunk (subscapular, midaxillary) to the sum of two extremity (triceps, medial calf) skinfolds (T/E) for subsamples of 102 boys and 63 girls. There were no sex differences in the S/T ratio (mm/mm), boys 0.62 +/- 0.15, girls 0.63 +/- 0.18; T/E ratio (mm/mm), boys 0.58 +/- 0.13, girls 0.59 +/- 0.16; and BMI (kg/m2), boys 17.1 +/- 2.4, girls 16.9 +/- 2.2. Second order partial correlations, controlling for age and the BMI or age and sum of skinfolds, between birth weight and the skinfold ratios are, respectively, -0.22 and -0.20 (p < 0.01) for S/T and -0.29 and -0.32 (p < 0.01) for T/E in girls, and -0.18 and -0.17 (p < 0.05) for S/T and -0.06 and -0.6 for T/E in boys. Though low, the correlations suggest that as birth weight decreases proportionally more subcutaneous fat is accumulated on the trunk than on the extremities, more so in females than in males. Results of stepwise multiple regression analyses indicate that birth weight accounts for from 2% to 8% of the variance in relative subcutaneous fat distribution at school age.

Adipose Tissue↗

PubMed1996

Physique as a risk factor for ulnar variance in elite female gymnasts.

The aims of this study were: 1) to determine ulnar variance variability of elite, female gymnasts; 2) to evaluate the relationship between ulnar variance and physique, maturity status, and training characteristics of these gymnasts. All 156 skeletally immature female gymnasts were participants at the World Championships Artistic Gymnastics, Rotterdam, The Netherlands, in 1987. Chronological ages varied between 13.1 and 20.6 yr (mean = 15.9 +/- 1.3 yr). A large set of anthropometric dimensions was taken and somatotype was determined by the Heath-Carter technique. Skeletal age was assessed by the Tanner-Whitehouse II method. Menarcheal status and training data were collected by questionnaire. Ulnar variance was determined according to Hafner et al. Gymnasts differ significantly from reference girls with respect to physique and maturational status: gymnasts were smaller and delayed in skeletal maturity with about 1.5 yr. For those who had attained menarche, mean age at menarche was 15.1 +/- 1.3 yr. Ulnar variance shows a normal distribution in the gymnasts, ranging from -10.5 mm to +5.9 mm, which is somewhat more positive, i.e., an ulnar overgrowth, than reference wrists. The relationship between ulnar variance and somatic and maturational features suggests that female gymnasts who are more mature and have a physique characterized as relatively tall with a high lean body mass are at greater risk for developing a positive ulnar variance. No relationship between ulnar variance and training characteristics was evident. It is concluded that the observed positive ulnar variance in this sample of elite female gymnasts is less pronounced than originally stated in most "case reports."

Adolescent↗

PubMed1996

Anthropometric and motor characteristics of Senegalese children with different nutritional histories.

The effects of Protein Energy Malnutrition (PEM) on the motor performance of 4.5-6.5-year-old Senegalese children were studied. Body dimensions included weight, lengths, circumferences, and four skinfolds. Motor performance tests included a 3-min endurance run, 4 x 10 m shuttle-run, distance throw, standing long jump and grip strength. The sample consisted of 147 children: 52 children who were hospitalized for severe undernutrition (severe UN group) during infancy but who had been nutritionally rehabilitated; 63 children who were never severely malnourished but who were chronically exposed to mild-to-moderate undernutrition up to the time of study (chronic UN group); and 32 well nourished children (well nourished group) from well-off households. After adjusting for sex and age, the well nourished group performed better than the severe UN and chronic UN groups. Principal components analysis resulted in two factors which explained 65% of the variance in anthropometry and motor performance. One was related to body size and the second to body composition. The three nutritional groups differed significantly in principal component scores for the two factors; chronic UN and severe UN children also differed for the second factor. Body composition, especially low fat mass appeared to be an important feature for motor performance in chronically undernourished children.

Anthropometry↗

PubMed1994

Cardiovascular reactivity in isometric exercise and mental arithmetic in children.

In children, we studied noninvasively the cardiovascular stress responses, including changes over time of systolic blood pressure (SBP), heart rate (HR), and stroke volume (SV) in isometric handgrip (IHG) and mental arithmetic. Specifically, we asked whether 1) these cardiovascular stress responses were different for the two stress conditions in children, 2) these responses differed in boys and girls, and 3) the anthropometric variables related to these stress responses. SV differed significantly between IHG and mental arithmetic over the entire stress period. This may reflect higher systemic vascular resistance during IHG. HR in boys was lower than in girls over the entire period of stress in both stress tests. This observation cannot be attributed to differences in conditioning, because this should not influence responses to isometric or mental stress. A larger left ventricular mass was related to higher SVs. A marked relationship was found between HR and SBP and between HR and SV. No relationship was found between SBP and SV.

Blood Pressure↗

PubMed1994

Size, fatness and relative fat distribution of males of contrasting maturity status during adolescence and as adults.

The somatic characteristics of boys of contrasting biological maturity status during adolescence are compared from 13-18 years and at 30 years of age. Within the mixed longitudinal Leuven Growth Study of Belgian Boys, 173 boys were followed annually from 13-18 years and were subsequently measured at 30 years of age. Age at peak height velocity (PHV) was estimated for 149 boys and the sample was then divided into three contrasting maturity categories based on the age at PHV: early (PHV < 13.37 years), average (PHV between 13.85 and 14.80 years) and late (PHV > 15.27 years) maturers. Using ANOVA for repeated measures and one-way ANOVA, differences in 18 somatic dimensions and five ratios of body proportions and subcutaneous fat distribution among the three maturity groups were tested from 13-18 years and at 30 years of age. There are consistent differences among boys of contrasting breadths, circumferences,and skinfolds on the trunk. There are no differences in skinfolds on the extremities. None of the differences in somatic dimensions and ratios among the three contrasting maturity groups are significant at 30 years of age except those for subscapular skinfold and the trunk/extremity skinfold ratio. Thus, during adolescence and in adulthood, late maturing boys have a distribution of subcutaneous fat that is associated with lower risk for several adult degenerative diseases.

Adipose Tissue↗