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Biomedical subjects

Z Laron

Publications and source records attributed to Z Laron.

At least 19 recordsLinked to original sources
PubMed2000

Echocardiographic dimensions and function in adults with primary growth hormone resistance (Laron syndrome).

Patients with primary growth hormone (GH) resistance-Laron Syndrome (LS)-have no GH signal transmission, and thus, no generation of circulating insulin-like growth factor-I (IGF-I), and should serve as a unique model to explore the controversies concerning the longterm effect of GH/IGF-I deficiency on cardiac dimension and function. We assessed 8 patients with LS (4 men, 4 women) with a mean (+/- SD) age of 38+/-7 years (range 22 to 45), and 8 aged-matched controls (4 men, 4 women) with a mean age of 38+/-9 years (range 18 to 47) by echocardiography at rest, following exercise, and during dobutamine administration. Left ventricular (LV) septum, posterior wall, and end-diastolic diameter were significantly reduced in untreated patients with LS compared with the control group (p<0.05 for all). Systolic Doppler-derived parameters, including LV stroke volume, stroke index, cardiac output, and cardiac index, were significantly lower (p<0.05 for all) than in the control subjects, whereas LV diastolic Doppler parameters, including mitral valve waves E, A, E/A ratio, and E deceleration time, were similar in both groups. LV ejection fraction at rest as well as the stress-induced increment of the LV ejection fraction were similar in both groups. Our results show that untreated patients with long-term IGF-I deficiency have reduced cardiac dimensions and output but normal LV ejection fraction at rest and LV contractile reserve following stress.

Adult↗
PubMed2000

Incidence of Type 1 diabetes mellitus in children aged 0-14 in Japan, 1986-1990, including an analysis for seasonality of onset and month of birth: JDS study. The Data Committee for Childhood Diabetes of the Japan Diabetes Society (JDS).

AIMS: To detect the incidence of childhood Type 1 diabetes mellitus (DM) (0-14 years) in Japan and to find out whether there is a seasonal pattern in the onset of disease and month of birth of children with diabetes. METHODS: Ascertained data for the period 1986-1990 could be collected in 35 out of 47 local government areas representing 69.4% of the childhood population (aged 0-14 years) of Japan. RESULTS: A total of 1,260 children with Type 1 DM were identified (738 girls, 522 boys). With age there was a progressive increase in incidence from 0.7 to 2.1/10(5) in boys and from 0.6 to 3.5/10(5) in girls. With the exception of 1987, when a coxsackie B3 virus epidemic was registered, no seasonal variation in the month of onset was observed, nor was a seasonal pattern of the month of birth registered in this cohort. CONCLUSIONS: Compared to European countries, the USA and Israel, the Japanese cohort of children with diabetes presents the following differences: the incidence is much lower, there is a preponderance of girls and there is (with one exception) no seasonal pattern.

Adolescent↗
PubMed2000

Comparison of the growth-promoting effects of insulin-like growth factor I and growth hormone in the early years of life.

AIMS: Four infants with isolated growth hormone deficiency (IGHD) and five with Laron syndrome (LS) were studied. Birth length ranged from -2.5 to -4.5 SDS in both groups. RESULTS: Untreated IGHD children decreased in length from -2.5 to -5.2 SDS at 1 y and to -5.7 SDS at 2 y. Human growth hormone (hGH) treatment (0.07 U/kg/d) increased height by 1.2-2.4 SDS in 3 y. Untreated children with LS decreased in length from -3.5 to -6.5 SDS. Insulin-like growth factor (IGF)-I treatment (150-200 microg/kg/d) in 3 LS patients increased height by 0.5-1.5 SDS in 3 y. All untreated infants had borderline or below normal head circumferences. Both treatments induced a rapid catch-up in head size. In the two untreated LS patients, head circumference remained subnormal. CONCLUSIONS: Despite similar birth length, infants with IGHD responded better to hGH in terms of linear growth than did infants with LS to IGF-I, whereas the response in brain growth was similar.

Age Factors↗
PubMed2000

Neuroendocrinological response to standardized mixed meal in female anorectic patients during active and refeeding phases.

To evaluate the neuroendocrinological dysfunction in anorexia nervosa, plasma somatostatin, glucose, insulin, and growth hormone were monitored in ten patients with anorexia nervosa in the active and refeeding (remission) phases of the disorder and in nine age-matched healthy control subjects. Somatostatin levels were significantly higher in the anorectic patients in both the active and refeeding phases than in the controls at baseline (mean+/-SD 27.4 +/-5.5 and 31.1+/-2.6 vs 21.3+/-1.9 pg/ml; p<0.001), and significantly higher in the anorectic patients in the active phase compared to the refeeding phase and to the controls in response to a mixed meal (p<0.05). Insulin levels were significantly lower in the anorectic patients in both the active and refeeding phases compared to the controls at baseline (9.3+/-1.1, 7.6+/-1.0 vs 14.7+/-3.5 microU/ml; p<0.0001) and after a mixed meal (p<0.05). An attenuated glucose response discriminated the anorectic patients in the active state from the same patients in the refeeding state and the controls (p<0.0001). There was no significant difference in growth hormone response between the anorectic patients and the controls. These findings suggest that there is an augmented response of somatostatin and an attenuated response of insulin to mixed meal stimulation in active anorexia. The diminished insulin response persists during the refeeding phase. It seems that central and peripheral alterations in endocrine function occur in anorexia nervosa.

Adolescent↗
PubMed2000

Experience with cyproterone acetate in the treatment of precocious puberty.

The authors review their experience (1967-present) in the use of cyproterone acetate (CPA) in precocious puberty. CPA was found effective in persistently suppressing pituitary gonadotropic secretion when administered orally at a dose of 50 mg b.i.d. (70-100 mg/d). After the introduction of gonadotropic analogues (GnRHa) for treatment of central precocious puberty, short term use of CPA was found useful to counteract the initial stimulatory effect of the GnRHa as well as an adjunct drug in case of very active adrenarche causing advanced bone age during GnRHa treatment. The final heights of girls treated with CPA and girls treated with D-Trp6-LHRH were found comparable: 157.8+/-5.1 cm vs 159.6+/-6.3 cm, respectively. The main adverse effects were occasional fatigue due to partial adrenal insufficiency with CPA and gynecomastia in a few boys. Liver function tests were normal in all patients with the exception of one boy with severe hypothalamic disease, including precocious puberty, who developed liver cirrhosis 3 years after stopping CPA following 5 years treatment. Other indications for CPA treatment during childhood and adolescence, such as fast puberty, congenital adrenal hyperplasia and acne, are also mentioned.

Body Height↗
PubMed2000

Delayed growth and puberty in patients with Gaucher disease type 1: natural history and effect of splenectomy and/or enzyme replacement therapy.

BACKGROUND: Growth retardation in childhood was only recently recognized as a prominent feature of Gaucher disease type 1, but there are few data on both the pubertal development and the final outcome of growth and sexual maturation. OBJECTIVE: To investigate the natural pattern of growth and puberty in patients with Gaucher disease type 1 and the effect of splenectomy and enzyme replacement therapy. METHODS: We retrospectively analyzed growth and puberty in 57 patients with Gaucher disease type 1; 52 were followed since childhood and/or prepuberty and 42 have reached sexual maturity and final height. In the analysis we considered severity of disease, time of splenectomy, and start of enzyme replacement therapy. RESULTS: Deceleration of growth at age 3-5 years was observed in 30 of 57 patients followed since early childhood while untreated: height-SDS decreased from -0.34 +/- 0.42 at age 0-3 years to -1.93 +/- 0.95 (P < 0.01) at age 7-10 years and was more pronounced with severe disease. A high prevalence (59.6%) of delayed puberty, which was more frequent with severe disease, was observed in 47 patients followed before and throughout puberty. No primary endocrine pathology was found. All patients, untreated as well as treated, with growth and pubertal delay had a spontaneous catch-up, achieved full sexual maturation, and most (83.3%) reached a final height within the range of parental height-standard deviation score. Splenectomy (partial and/or total) performed in 20 patients while still growing had a beneficial effect on growth, which was temporary in some and did not affect puberty. ERT improved growth in 11 patients who started therapy before puberty, as evidenced by a progressive increase in the height-SDS, and seemed to normalize the onset of puberty. CONCLUSIONS: Growth retardation in childhood and delay of puberty are characteristic of Gaucher disease type 1 and are more frequent with severe disease. There is a spontaneous catch-up later in life and most patients reach a final height within their genetic growth potential. Enzyme replacement therapy apparently normalizes growth and possibly also the onset of puberty.

Adolescent↗
PubMed1999

Changes in bone mineral density after discontinuation and early reinstitution of growth hormone (GH) in patients with childhood-onset GH deficiency.

We measured bone mass density (BMD) in 28 childhood-onset adult GHD patients (20 MPHD, 8 IGHD) treated with hGH until final height. Twelve were re-treated with hGH (0.06 U/kg/day three times per week) for 16-24 months and eight of them followed for up to 5 years. Age at start of the study was 23.6 +/- 5.7 years (mean +/- SD) and the interval since the first hGH treatment was 5.8 +/- 4.4 years Baseline BMD was 82% of young normal healthy subjects. Patients < 20 years had a lower BMD than those > 20 years (75 vs 87%;P = 0.004). In the 12 patients re-treated with GH, BMD was 5.3% above baseline at 6 months after treatment was stopped (P< 0.002), and remained so for 3.5 years in eight patients who completed follow-up. In conclusion, increases in BMD occur after cessation of growth, but continuation of hGH treatment after final height achievement may prevent the late osteopenia of patients with childhood-onset GHD.

Adolescent↗
PubMed1999

The essential role of IGF-I: lessons from the long-term study and treatment of children and adults with Laron syndrome.

Fifty patients with primary GH resistance (Laron syndrome) due to molecular defects of the GH receptor or post-receptor pathways were followed from infancy through adulthood. This condition leading to long-term insulin-like growth factor-I (IGF-I) deprivation caused marked growth retardation (-4 to 8 height SD), acromicia, organomicria, retarded development of the skeletal and muscular systems, a small cranium, slow motor development, and impairment of intellectual development in some of the patients. In addition, there was progressive obesity, insulin resistance, a tendency for hypoglycemia, followed later in life by hypercholesterolemia and by glucose intolerance and even diabetes. IGF-I treatment of children with Laron syndrome, by our and other groups (150-240 microg/day sc), stimulated growth (8 cm in the first year and 4-5 cm in the following years) and normalized the biochemical abnormalities. Overdosage led to adverse effects such as hypoglycemia, edema, swelling of soft tissues, and hyperandrogenism. It is concluded that primary IGF-I deprivation induces severe auxological, biochemical, and hormonal changes, the only treatment being biosynthetic IGF-I administration.

Adolescent↗
PubMed1999

Lessons from recent epidemiological studies in type 1 childhood diabetes.

Recent studies have revealed that seasonality of onset of childhood insulin-dependent diabetes mellitus (IDDM) with a peak late in autumn and winter exists in populations with medium or high incidence of disease and parallels viral epidemics. In populations with low incidence no seasonality has been found, probably due to the development of tolerance towards the infectious agent(s). Analysis of the month of birth of children with IDDM showed a temporal shift with a peak in spring, but again only in populations with a medium or high incidence of childhood IDDM. This finding is suggestive of a transfer of virus infections from the mother to the fetus during the viral epidemic period. This unsymptomatic infection is assumed to cause the first pancreatic beta-cell damage which after subsequent damage leads to overt diabetes.

Child↗
PubMed1999

Natural history of the classical form of primary growth hormone (GH) resistance (Laron syndrome).

A description of the clinical, biochemical and endocrinological features of the classical form of the syndrome of primary growth hormone (GH) resistance (Laron syndrome) is presented including the progressive changes during follow-up from infancy into adulthood. The main diagnostic features are: severe growth retardation, acromicria, small gonads and genitalia, and obesity. Serum GH levels are elevated and insulin-like growth factor-I (IGF-I) values are low and do not rise upon stimulation by exogenous hGH. The pathogenesis of this syndrome is due to various molecular defects from exon deletion to nonsense, frameshift, splice and missense mutations in the GH receptor (GH-R) gene or in its post-receptor pathways.

Abnormalities, Multiple↗
PubMed1998

Interventional catheterization decreases plasma levels of atrial natriuretic peptide (ANP) in children with congenital heart defects.

Atrial natriuretic peptide (ANP) is one of the cardiac peptides implicated in volume and sodium homeostasis. We investigated the effect of interventional catheterization on plasma levels of ANP, aldosterone, and cortisol in 28 children with various congenital heart defects (CHD). Patients were divided by age into two groups: group A--infants and children over 3 months of age (n = 22), and group B--newborns (n = 6). These were compared to age-matched control groups. In group A, interventions included pulmonic valvotomy (n = 8), aortic valvotomy (n = 4), balloon angioplasty of native coarctation of the aorta (n = 3), balloon dilatation of the mitral valve (n = 1), and Rashkind double umbrella closure of patent ductus arteriosus (n = 6). Group B interventions included pulmonic valvotomy (n = 3), aortic valvotomy (n = 1), and balloon atrial septosomy (n = 2). In group A, mean ANP levels were markedly higher than in age-matched controls (125.2+/-15.8 vs. 24.6+/-4.6 pg/ml) (P <0.0001), and decreased immediately after intervention (75.6+/-11.4 pg/ml, P <0.02), and more markedly on follow-up (42.9+/-5.0 pg/ml, P < 0.0001). In group B (newborns), mean basal plasma levels were high before and after intervention and were not different from age-matched controls (243+/-42.1 vs. 220.8+/-16.2 pg/ml). There was a significant decrease on follow-up measurement (62.1+/-12.7 pg/ml, P < 0.005). In both groups, plasma cortisol levels increased significantly immediately following catheterization (P < 0.02), and normalized on follow-up. Basal aldosterone levels were normal in group A and high in Group B (9.9+/-3.8 vs. 167.6+/-16.9 ng/dl) (P < 0.001). It is suggested that plasma ANP levels are increased in children with CHD, without overt heart failure, and decrease significantly following successful intervention. In newborns with CHD, the physiological high ANP levels obscure the effect of the CHD.

Aldosterone↗
PubMed1998

Development of hyperandrogenism during treatment with insulin-like growth factor-I (IGF-I) in female patients with Laron syndrome.

OBJECTIVE: Patients with Laron syndrome (LS) can now be treated with recombinant IGF-I. We describe the development of androgenization during IGF-I treatment of female LS patients. PATIENTS: Six female patients with LS--two clinically prepubertal (11.6 and 13.8 years of age) and four young adults (30 to 39 years old)--underwent long-term replacement treatment with recombinant IGF-I. The daily doses were 150 micrograms/kg/day by subcutaneous (s.c.) injection in the girls and 120 micrograms/kg/day in the adult women. METHODS: Testosterone, delta 4-androstenedione, LH, FSH, insulin and IGF-I were determined by radioimmunoassay. Blood samples were obtained after an overnight fast before the IGF-I injection. Serum IGF-I was also determined 4 hours after the s.c. injections. RESULTS: During IGF-I treatment, four out of the six patients (two girls and two adults) developed progressive clinical symptoms and signs of hyperandrogenism (oligo/amenorrhoea and acne). Laboratory determinations showed a significant elevation in serum testosterone, delta 4-androstenedione and LH/FSH ratio. The hyperandrogenism occurred concomitantly with an increase in IGF-I serum and a decrease in serum insulin concentrations. Reduction in IGF-I dose or interruption in IGF-I treatment restored androgen levels to normal values. At the same time, the acne and oligomenorrhoea resolved. CONCLUSIONS: Overdosage of IGF-I can lead to androgenization, a previously undescribed undesirable effect of IGF-I. Long-term IGF-I treatment necessitates progressive adjustment of the IGF-I dose to avoid overtreatment.

Adolescent↗