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Biomedical subjects

A Eliakim

Publications and source records attributed to A Eliakim.

At least 19 recordsLinked to original sources
PubMed2006

Assisted exercise and bone strength in preterm infants.

Studies have previously demonstrated that brief (4 weeks) passive range-of-motion exercise is beneficial for bone development in very low birth weight (VLBW) preterm infants. However, the optimal duration of exercise for bone development in preterm infants is yet unknown. The aim of the present study was to examine the effect of 8 weeks of assisted exercise on bone strength and metabolism in VLBW premature infants. Sixteen infants (mean +/- standard error of the mean birth weight 1,009 +/- 55 g and gestational age 27.3 +/- 0.3 weeks) were randomly assigned into exercise (n = 8) and control (n = 8) groups. The intervention started at the first week of life and involved 8 weeks of daily passive extension and flexion range-of-motion exercise of the upper and lower extremities. Biochemical markers of bone turnover were measured at enrollment and after 8 weeks. Bone strength was measured weekly by quantitative ultrasound measurement of tibial bone speed of sound (SOS). Bone SOS decreased significantly in the control group (-108.1 +/- 33.7 m/second, P < 0.0001) during the study period, while remaining stable in the exercise group (11.3 +/- 22.8 m/second). The main beneficial effect of exercise occurred in the first 4 weeks of the intervention. There were no significant differences in the bone turnover marker changes between the groups. There is a significant postnatal decrease in bone SOS in VLBW preterm infants. Eight weeks of assisted range-of-motion exercise attenuates the decrease in bone strength and may decrease the risk of osteopenia in premature infants.

Body Weight↗
PubMed2006

A cumulative effect of physical training on bone strength in males.

Weight-bearing, high-impact exercise, as opposed to nonimpact exercise, has been demonstrated to increase bone mineral density. This was traditionally demonstrated with dual energy X-ray absorptiometry. Our objective was to assess the differences in bone properties, using quantitative ultrasound (QUS, Sunlight Omnisense, Sunlight Medical, Ltd., Tel Aviv, Israel), in male athletes involved in a weight-bearing, impact sport (soccer, SC) or a nonimpact sport (swimming and water polo, AQ), compared with nonathletic control (C) males. A total of 266 boys and men, aged 8 - 23 years, were divided into children (11.1 +/- 1.0 years; 34 SC, 34 AQ, 25 C), adolescents (14.7 +/- 1.2 years; 32 SC, 31 AQ, 31 C), and young adults (19.8 +/- 1.1 years; 31 SC, 24 AQ, 24 C) . Training experience varied between 1.5 years in the children to 15 years in the adults. Bone speed of sound (SOS) was measured bilaterally at the distal radius and the mid-tibia. Body fat was significantly lower in athletes compared with C. AQ were generally heavier and had a higher fat-free mass compared with SC and C, with no significant differences in height between groups. Radial SOS increased with age, but no differences were observed between activity groups or between the dominant (D) and nondominant (ND) arm. Tibial SOS also increased with age. In the children and adolescents, no differences were observed between activity groups. However, among adults, both SC and AQ had higher tibial SOS compared with C. These differences were mainly explained by differences in fat-free mass. Among young adults but not among children and adolescent males, both soccer and aquatic sports appear to be associated with higher bone SOS in the lower, but not the upper, extremities. Further studies are needed to assess possible sport-specific mechanisms which affect bone properties and to determine the minimal cumulative effect which is needed to influence bone properties.

Adolescent↗
PubMed2006

The effect of music during warm-up on consecutive anaerobic performance in elite adolescent volleyball players.

Music is believed to improve athletic performance. The aim of the present study was to determine the effect of arousing music during warm-up on anaerobic performance in elite national level adolescent volleyball players. Twenty-four players (12 males and 12 females) performed the Wingate Anaerobic Test following a 10-minute warm-up with and without music (two separate occasions, random order). During warm-up with music, mean heart rate was significantly higher. Following the warm-up with music, peak anaerobic power was significantly higher in all volleyball players (10.7 +/- 0.3 vs. 11.1 +/- 0.3 Watts/kg, p < 0.05, without and with music, respectively). Gender did not influence the effect of music on peak anaerobic power. Music had no significant effect on mean anaerobic output or fatigue index in both genders. Music affects warm-up and may have a transient beneficial effect on anaerobic performance.

Acoustic Stimulation↗
PubMed2006

A combined dietary-physical activity intervention affects bone strength in obese children and adolescents.

Obesity has become the most common pediatric chronic disease in the modern era. Recent data suggests that unlike obese adults, obese children and adolescents may have decreased bone strength. It was the objective to prospectively examine the short term effects of a 3 month combined dietary-physical activity intervention on anthropometric measures, body composition, fitness and bone strength in obese children. Twelve obese subjects completed the 3 m intervention and were compared to 12 obese age and gender matched controls. Bone strength was measured using quantitative ultrasound measurements of bone speed of sound (SOS). There were significant differences in changes of body weight (0.01 +/- 0.7 vs. 2.3 +/- 0.6 kg, p = 0.033), BMI percentiles (- 2.8 +/- 1.1 vs. - 0.2 +/- 0.2 %, p = 0.037), body fat percent (by skinfolds, - 1.5 +/- 0.8 vs. 0.7 +/- 0.5 %, p = 0.035), and endurance time (170 +/- 42 vs. 50 +/- 27 s, p = 0.045) in the intervention vs. control subjects, respectively. In addition, we found a significant difference in the change of bone SOS between the intervention and control group subjects (21.5 +/- 21.6 vs. - 87.0 +/- 37 m/s, p = 0.023). During the critical period of bone development of childhood and adolescence, a combined dietary-physical activity intervention leads to increased bone strength in obese children. These results highlight the importance of multi-disciplinary programs for the treatment of childhood obesity and its complications.

Adolescent↗
PubMed2005

Bone properties and muscle strength of young haemophilia patients.

PURPOSE: To evaluate bone properties, muscle strength and the relationship between the two, in young (7.0-17.7 years) haemophilia patients (h) and healthy boys (c). SUBJECTS: Twenty-seven boys with severe haemophilia and 33 healthy boys, of similar age, body mass, height, (mean +/- sd for h and c, respectively: 11.2 +/- 3.2 vs. 11.4 +/- 2.9 years, 42.6 +/- 16.6 vs. 41.6 +/- 17.3 kg, 145 +/- 18 vs. 146 +/- 17 cm) and pubertal stage according to secondary sex characteristics, volunteered for the study. all subjects were physically inactive (as determined by questionnaire). METHODS: Subjects performed isokinetic elbow and knee extension and flexion tests at two angular velocities (biodex system ii dynamometer). Bone properties were evaluated by qualitative ultrasound (sunlight omnisense), at the distal radius and tibial mid-shaft. H subjects received prophylactic factor viii treatment within the 24 h preceding testing. No test was performed in the presence of haemorrhage. RESULTS: Muscle strength was consistently higher in c compared with h, especially in the lower limbs (e.g. knee extension: 1.80 +/- 0.44 vs 1.48 +/- 0.53 N x m x kg(-1) body mass, respectively, p = 0.01). No differences were observed in tibial or radial speed of sound between groups. Correlations between muscle strength and bone properties were observed only in the lower limbs and only in c (r = 0.37-0.48). CONCLUSION: Muscle strength, especially lower limbs' strength, was lower in haemophilia patients compared with a matched, similarly inactive population of healthy boys. Nevertheless, at this age range, this relative weakness is not associated with inferior bone properties.

Adolescent↗
PubMed2005

Three novel mutations in POU1F1 in Israeli patients with combined pituitary hormone deficiency.

BACKGROUND: POU1F1, a pituitary-specific transcription factor of the class 1 POU family, is crucial for the development and differentiation of the anterior pituitary gland. Mutations in the POU1F1 gene have been shown to be responsible for a syndrome of combined pituitary hormone deficiency (CPHD), including prolactin, growth hormone and thyroid-stimulating hormone deficiencies. METHODS: Five patients with CPHD from three families were evaluated. The clinical and biochemical data were taken from the medical records. DNA was analyzed by polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and sequencing. RESULTS: Molecular analysis yielded three novel mutations in POU1F1: W193X, Q242R (-2 bp), and F262L. CONCLUSIONS: Three novel POU1F1 mutations were detected in Israeli patients with CPHD. Two of them, a W193X missense mutation and a deletion of two adenine bases at position 242Q, may lead to the production of a truncated protein that lacks the entire POU homeodomain or part of it, respectively. The third mutation, F262L, resides in the POU homeodomain and hence might change the activity of the protein.

Arginine↗
PubMed2004

Higher tibial quantitative ultrasound in young female swimmers.

BACKGROUND: It has been found that swimming, a non-impact sport, generally has no effect on bone mineral density. OBJECTIVES: To examine bone properties, as measured by quantitative ultrasound, among female swimmers in comparison with control girls and women. METHODS: Subjects included 61 swimmers and 71 controls aged 8.5 to 26.5 years. None of the swimmers was at the elite level and none had included resistance training in her schedule. Bone speed of sound (SOS) was measured bilaterally at the distal radius and the mid-tibia. RESULTS: No differences were observed between swimmers and controls in body mass (mean (SD): 49.7 (12.3) v 50.7 (12.4) kg, respectively), although swimmers were taller (159 (12) v 155 (12) cm) and had lower body fat (18.3 (4.2)% v 22.3 (5.4)%). No difference was found in time since menarche (5.2 (4.0) and 4.5 (2.9) years in swimmers and controls, respectively; 21 swimmers and 25 control were premenarcheal). Radial speed of sound (SOS) increased with age but did not differ between swimmers and controls (non-dominant: 3904 (172) and 3889 (165) m/s for swimmers and controls, respectively). Tibial SOS also increased with age and was significantly higher in swimmers than in controls (non-dominant: 3774 (155) v 3712 (171) m/s). No differences were found between dominant and non-dominant sides. CONCLUSIONS: Swimming appears to be associated with higher bone SOS in the lower but not in the upper extremities. Further studies are needed to assess whether this difference reflects higher habitual activity among the swimmers or swimming specific mechanisms.

Absorptiometry, Photon↗
PubMed2002

Evidence for exercise-induced bone formation in premature infants.

We assessed the effect of a four weeks exercise training intervention on bone turnover markers in premature infants. Twenty-four very low birth weight premature infants were matched for gestational age, birth weight, gender, as well as for corrected age and weight at initiation of the study. Then the subjects were randomly divided into an exercise (n = 12) and a control group (n = 12). Exercise consisted of passive range of motion exercise with gentle compression of both the upper and lower extremities lasting 5 - 10 minutes each day, 5 days per week for 4 weeks. This protocol has been shown to increase bone mineral density in premature infants. Bone formation was assessed by measurements of circulating bone specific alkaline phosphatase (BSAP) and the C-terminal procollagen peptide (PICP). Bone resorption was determined by serum measurements of C- terminal cross-links telopeptide of type-I collagen (ICTP). Training led to a significant (P < 0.05) increase in weight gain (767 +/- 49 versus 586 +/- 24 gr in trained and control premature infants, respectively); and to a significant increase in BSAP (37.2 +/- 14.6 versus 4.1 +/- 8.4 % in trained and control premature infants, respectively). PICP increased also following exercise (34.6 +/- 18.9 versus 5.4 +/- 9.1 % in trained and control subjects, respectively), however, this increase was not statistically significant. Exercise led to a significant decrease in ICTP (-24.7 +/- 3.1 versus -5.5 +/- 5.4 % in trained and control subjects, respectively). A relatively brief exercise intervention was associated with a biochemical evidence of bone formation in very low birth weight premature infants.

Alkaline Phosphatase↗
PubMed2002

Changes in circulating IGF-I and their correlation with self-assessment and fitness among elite athletes.

The evaluation of training load and effectiveness in elite athletes is difficult. We determined the effect of a four-week training camp on changes in self-assessment physical conditioning scores, fitness and circulating IGF-I in elite Israeli handball players during their preparation for the 1999 World Junior Handball Championship. Training consisted of two weeks of intense training followed by two weeks of relative tapering. Fitness was assessed by field test measurements of 1000-m run, 4 x 10-m shuttle run and vertical jump. Serum IGF-I levels were measured by immunoradiometric assay. Measurements were performed before, after two weeks, and at the end of training. Training resulted in a significant (p < 0.05) improvement in the results of the 4 x 10-m run, 1000-m run and vertical jump. Changes in the self-assessment physical conditioning score showed a bi-directional pattern. After two weeks of training the players reported decreased physical conditioning scores, with return to basal levels after four weeks. Similarly, circulating IGF-I decreased significantly after two weeks, and returned to basal levels after four weeks of training. We found a significant correlation between changes in circulating IGF-I, and self-assessments of physical conditioning scores (r = 0.71, p < 0.001). Intensive training resulted in a decrease, while tapering was associated with an increase in IGF-I levels. These changes were accompanied by parallel changes in subjective physical conditioning self-assessments.

Adaptation, Physiological↗
PubMed2002

Stress fractures of the medial malleolus--review of the literature and report of a 15-year-old elite gymnast.

Stress fracture of the medial malleolus is rare and not reported in children. We report a case of a 15-year-old elite gymnast with open physes sustaining a medial malleolar stress fracture. The patient was treated initially by rest and gradually returned to sport with full recovery. Two months later she developed a complete fracture of the medial malleolus of the same side. This was treated surgically by open reduction and internal fixation with a cancellous screw and soon after the operation she returned to full activities. Emphasis is given to the suspected mechanism which led to this unique fracture and to the hormonal aspects in the professional adolescent gymnast. We recommend surgical treatment of stress fracture of the medial malleolus especially for elite athletes, leading to early recovery and return to sports activities.

Adolescent↗
PubMed2002

The association between adiposity and the response to resistance training among pre- and early-pubertal boys.

Resistance training has been shown to be effective in enhancing muscle strength among prepubertal and adolescent boys. Lately, it has been recommended for obese children. We hypothesized that resistance training will be similarly effective among boys of different adiposity. Thirty boys, aged 9.2 +/- 0.3 years, participated in progressive resistance training twice weekly during the first and second school years and thrice weekly during the third year. Training sessions included 1-4 sets of 3-6 exercises, with 5-30 repetitions/set. The mean load was 50-60% of 1 repetition maximum. Subjects were divided into responders (R--upper tertile) and non-responders (NR--lower tertile), according to the three-year improvement in muscle strength, as assessed by means of changes in concentric strength of knee flexors and extensors. Differences between groups were observed at baseline (p <0.05) in all variables reflecting adiposity (mean +/- SD): % body fat (14.1 +/- 2.6 vs 23.5 +/- 7.5% for R and NR, respectively), sum of four skinfolds (25.4 +/- 4.7 vs 47.8 +/- 21.6 mm for R and NR, respectively), BMI (15.5 +/- 1.1 vs 18.6 +/- 2.6 kg x m(-2) for R and NR, respectively). Additionally, the changes in adiposity were inversely related to the training effect (r = -0.60 to -0.34). No differences were observed in initial height and maturation between R and NR groups and there was no difference in linear growth and physical maturation with time between groups. These data suggest that resistance-training loads which may be appropriate to increase strength of knee flexors and extensors in normal-weight children may be insufficient to do so in overweight children. More research is required to elucidate the efficacy of resistance training among overweight children.

Adipose Tissue↗
PubMed2002

Screening blood tests in members of the Israeli National Olympic team.

BACKGROUND: Blood samples are frequently collected in elite athletes in order to screen for possible medical conditions that might affect their athletic performance. However, the extent of these blood screening programs is not known. METHODS: Blood samples were collected from all members of the Israeli National Olympic team (n=114; 75 males, 39 females, mean age 23.4+/-0.5 years) to screen for possible medical conditions that might affect their athletic performance. All the athletes participated in individual sports. Fasting, early morning blood was sampled from all the athletes during the early phases of the training season (period of relatively light training). Blood was collected for erythrocyte sedimentation rate, complete blood count, chemistry panel, lipid profile, and iron stores analysis. RESULTS: Fifteen athletes (13%; 9 females, 6 males) had low ferritin levels (<20 ng/ml) indicating decreased iron stores. Four of these athletes (3.5%) had overt iron deficiency anemia. Two other athletes had B12 deficiency anemia. Three athletes had elevated serum creatinine and urea. Surprisingly, elevated levels of cholesterol (>200 mg/dl) were found in 15 athletes (13%). Moreover, 24 athletes (21%) had mild low HDL-cholesterol levels. No electrolyte abnormalities were found. CONCLUSIONS: Evaluation of iron stores should be performed in elite athletes, due to the relatively high prevalence of depleted iron stores and iron deficiency anemia, which may affect their athletic performance. We suggest that renal function should be tested in athletes prior to the use of food supplements and/or medications that may interfere with their renal function. Further studies are needed to determine the benefits of screening tests in elite athletes.

Adult↗
PubMed2001

Quantitative ultrasound measurements of bone speed of sound in premature infants.

UNLABELLED: We measured bone speed of sound in premature infants by quantitative ultrasound. A total of 44 neonates participated in the study including 29 premature infants (median birth weight 1264 g, range 578-2420 g; median gestational age 31 weeks, range 24-36 weeks) and 15 full-term infants (median birth weight 3360 g, range 2700-3730 g; median gestational age 40 weeks, range 37-41 weeks). The left tibial speed of sound (SOS) was measured by quantitative ultrasound. Bone SOS was successfully measured in all infants. We found a significant correlation between tibial SOS and gestational age (r = 0.78, P < 0.0005), but a significant inverse correlation between tibial SOS and post-natal age (r = -0.78, P < 0.0005). Bone SOS was significantly (P < 0.05) higher in full-term infants (3101 m/s, range 2899-3314 m/s) compared to premature infants (2821 m/s, range 2516-3139 m/s), and compared to a subgroup of the premature infants who reached corrected age of full-term infants (2706 m/s, range 2516-2892 m/s, n = 13). Bone SOS was lower (2745 m/s, range 2533-3036 m/s, n = 16) in very low birth weight premature infants (birth weight < 1500 g). CONCLUSION: The results indicate that tibial speed of sound was reduced in premature infants (in particular very low birth weight) compared to full-term infants even when premature infants reached the corrected age of their full-term peers. The potential role of this technique in assessing osteopenia in premature infants warrants further exploration.

Alkaline Phosphatase↗
PubMed2001

Training, muscle volume, and energy expenditure in nonobese American girls.

Little is known about the relationship among training, energy expenditure, muscle volume, and fitness in prepubertal girls. Because physical activity is high in prepubertal children, we hypothesized that there would be no effect of training. Forty pre- and early pubertal (mean age 9.1 +/- 0.1 yr) nonobese girls enrolled in a 5 day/wk summer school program for 5 wk and were randomized to control (n = 20) or training groups (n = 20; 1.5 h/day, endurance-type exercise). Total energy expenditure (TEE) was measured using doubly labeled water, thigh muscle volume using magnetic resonance imaging, and peak O(2) uptake (VO(2 peak)) using cycle ergometry. TEE was significantly greater (17%, P < 0.02) in the training girls. Training increased thigh muscle volume (+4.3 +/- 0.9%, P < 0.005) and VO(2 peak) (+9.5 +/- 6%, P < 0.05), effects surprisingly similar to those observed in adolescent girls using the same protocol (Eliakim A, Barstow TJ, Brasel JA, Ajie H, Lee W-NP, Renslo R, Berman N, and Cooper DM, J Pediatr 129: 537-543, 1996). We further compared these two sample populations: thigh muscle volume per weight was much lower in adolescent compared with prepubertal girls (17.0 +/- 0.3 vs. 27.8 +/- 0.6 ml/kg body mass; P < 0.001), and allometric analysis revealed remarkably low scaling factors relating muscle volume (0.34 +/- 0.05, P < 0.0001), TEE (0.24 +/- 0. 06, P < 0.0004), and VO(2 peak) (0.28 +/- 0.07, P < 0.0001) to body mass in all subjects. Muscle and cardiorespiratory functions were quite responsive to brief training in prepubertal girls. Moreover, a retrospective, cross-sectional analysis suggests that increases in muscle mass and VO(2 peak) may be depressed in nonobese American girls as they mature.

Body Height↗
PubMed2001

Fitness, training, and the growth hormone-->insulin-like growth factor I axis in prepubertal girls.

We recently demonstrated that a brief endurance type training program led to increases in thigh muscle mass and peak oxygen uptake (VO(2)) in prepubertal girls. In this study, we examined the effect of training on the GH-->insulin-like growth factor I (GH-->IGF-I) axis, a system known to be involved both in the process of growth and development and in the response to exercise. Healthy girls (mean age 9.17 +/- 0.10 yr old) volunteered for the study and were randomized to control (n = 20) and training groups (n = 19) for 5 weeks. Peak VO(2), thigh muscle volume, and blood samples [for IGF-I, IGF-binding proteins (IGFBP)-1 to -6, and GHBP] were measured. At baseline, IGF-I was significantly correlated with both peak VO(2) (r = 0.44, P < 0.02) and muscle volume (r = 0.58, P < 0.004). IGFBP-1 was negatively correlated with muscle volume (r = -0.71, P < 0.0001), as was IGFBP-2. IGFBP-4 and -5 were significantly correlated with muscle volume. We found a threshold value of body mass index percentile (by age) of about 71, above which systematic changes in GHBP, IGFBP-1, and peak VO(2) per kilogram were noted, suggesting decreases in the following: 1) GH function, 2) insulin sensitivity, and 3) fitness. Following the training intervention, IGF-I increased in control (19.4 +/- 9.6%, P < 0.05) but not trained subjects, and both IGFBP-3 and GHBP decreased in the training group (-4.2 +/- 3.1% and -9.9 +/- 3.8%, respectively, P < 0.05). Fitness in prepubertal girls is associated with an activated GH-->IGF-I axis, but, paradoxically, early in a training program, children first pass through what appears to be a neuroendocrine state more consistent with catabolism.

Body Height↗
PubMed2001

Quantitative ultrasound measurements of bone strength in obese children and adolescents.

Very few studies have examined the effect of childhood obesity on bone mineralization. The purpose of the present study was to determine bone strength by quantitative ultrasound (QUS) measurements of bone speed of sound (SOS) in obese children (n = 45; age range 6-17 yr). SOS was measured (by Sunlight Omnisense) in the mid-tibial and radial bones. Data were compared to age- and gender-matched norms of Israeli non-obese children. Radial and tibial SOS was significantly reduced in obese compared to non-obese children (p < 0.05). Bone SOS in obese children with BMI > 95th percentile was not significantly different from obese children with BMI from 85-95th percentile. Tibial and radial SOS were correlated with pubertal stage (r = 0.52, p < 0.005; and r = 0.35, p < 0.01, respectively), and with chronological age (r = 0.47, p < 0.005; and r = 0.32, p < 0.025, respectively). No significant correlation was found between endurance time as an indicator of fitness and bone SOS. Bone strength measured by QUS is reduced in obese children, but is not affected by the severity of obesity.

Adolescent↗
PubMed2001

Measurements of bone turnover markers in premature infants.

We determined the levels of circulating bone turnover markers in preterm infants during the first weeks of life. Twenty premature infants (mean gestational age 27+/-2.2 weeks, mean birth weight 894+/-231 g) hospitalized in the neonatal intensive care unit (NICU) at the Meir General Hospital, Israel, participated in the study. Measurements of bone turnover markers were performed at birth, and every week thereafter for an average follow-up of 11.2+/-0.7 weeks. Bone osteoblastic activity was assessed by measurements of circulating osteocalcin, bone-specific alkaline phosphatase (BSAP) and the C-terminal procollagen peptide (PICP) levels. Bone resorption was assessed by measurements of serum levels of the carboxy-terminal cross-links telopeptide of type I collagen (ICTP). All three markers of osteoblastic activity increased markedly and significantly during the first three weeks of life, and then continued to increase gradually until week 10 (p<0.01). Circulating ICTP levels increased in the first week of life and then decreased gradually throughout the follow-up (p<0.01). The study participants were divided into premature infants born at extremely low birth weight (ELBW: <1000 g, n=12) and very low birth weight (VLBW: 1000-1250 g, n=8). Osteocalcin (in weeks 2-5 of life), PICP (weeks 3-5), and ICTP levels (weeks 2-3) were significantly higher in VLBW preterms. These results suggest increased bone formation in premature infants in the first three months of life. The increased bone turnover in VLBW compared to ELBW premature infants may be the result of a generally higher morbidity in ELBW preterm infants in early stages of life.

Aging↗