摘要:

To investigate the relationship between plasma growth hormone (GH) and plasma GH-binding protein (GHBP) activity we studied the effects of exogenous and endogenous GH on GHBP in children with a normal response to GH stimulation. The effect of exogenous GH on plasma binding activity was studied for 12 h after the administration of a subcutaneous GH bolus of 0.1 IU/kg and during the first year of GH therapy. The effect of endogenous GH secretion on GHBP was studied by measuring the integrated concentration (IC) of GH and GHBP over 24 h by means of a continuous blood withdrawal procedure. We also measured the GH and GHBP response to GH provocative tests. One hundred and two prepubertal children, 69 males, 33 females, age 8.8 ± 2.2 years (mean ± SD), were studied. Eighty-one were short, < 2 SDS for age and gender, and 21 were of normal height for age and gender. There was no difference in IC-GHBP between boys and girls. It correlated positively with age and body mass index (r = 0.802, p < 0.001 and r = 0.340, p < 0.001, respectively) but correlated negatively with ICgh (r = -0.412, p < 0.001) and with height velocity standard deviation scores (SDS, r = -0.355, p = 0.001). No correlation of ICGHBP with maximal GH response to provocative tests, insulin-like growth factor 1 levels, height in SDS or growth velocity after 1 year of GH therapy was found. During a provocative test there is an abrupt increase in GH but no change in GHBP. A significant change in GHBP is seen after the subcutaneous administration of a superphysiological dose of GH at a dose of 0.1 IU/kg. During GH therapy, GHBP levels began to rise within 3 months and reached a maximum at 6 months. There was no difference in GHBP levels between the three protocols used (0.05 and 0.1 IU/kg/day or 0.25 IU/kg/dose 3 times per week. No correlation between GHBP and the growth response to GH therapy was found following chronic GH administration. It is concluded that the GHBP response to GH in children is dependent upon the duration of exposure to GH. GH therapy upregulates GHBP levels during the course of GH therapy until a steady state is reached at 6 month

ISSN:1663-2818    

DOI:10.1159/000183788

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Serum human growth hormone (hGH) levels were measured with three different commercial kits, comprising a radioimmunoassay (RIA) (bioMérieux, Marcy-l’Etoile, France, ‘bmpoly’) and two immunoradiometric assays (IRMA) (bioMérieux, ‘bmmono’, and CIS biolnternatiónal, Gif-sur-Yvette, France, ‘cismono’). Samples were collected after various stimulation tests [arginine-insulin, growth hormone-releasing hormone (GHRH), L-dopa and glucagon-β-axolol] from children who were undergoing evaluation for short stature. Values obtained with the IRMAs were consistently lower than those obtained with the RIA. Furthermore, the cismono/bmmono and cismono/bmpoly values ratios were always significantly higher when samples were collected during GHRH stimulation than during the other stimulation tests. These data indicate that GHRH could induce a particular form of hGH molecule (in nature or in amount), recognized by the monoclonal antibodies in the cismono kit and that a specific form of hGH may be released by

ISSN:1663-2818    

DOI:10.1159/000183789

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The role of the liver in regulating serum growth hormone-binding protein (GH-BP) was studied. We measured rat serum GH-BP and insulin-like growth factor 1 (IGF-1) 30 min to 96 h after 70% partial hepatectomy (PHP) or sham operation in adult male rats. Serum GH-BP declined sharply from 5.8 ± 0.1 % at baseline to 3.9 ± 0.5% by 48 h following PHP. By 72 h serum GH-BP returned to baseline level and remained at that level 96 h postoperatively. In sham-operated female rats, serum GH-BP was about 2-fold higher than in males (10.5 ± 1.46 versus 5.8 ± 0.2%), whereas 24 h after hepatectomy a significant drop of about 50% was observed (p < 0.001). Serum IGF-1 decreased within 2-4 h postoperatively in both sham-operated and PHP groups, but thereafter was lower in the PHP rats, up to 48 h after operation, compared to sham-operated rats (p < 0.03). The study shows that the liver has an important role in the determination of serum GH-BP levels. The return to normal GH-BP level, even before the liver regained its full size following hepatectomy, suggests an increase in GH-BP production by the regenerating li

ISSN:1663-2818    

DOI:10.1159/000183790

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

To further evaluate the role of growth hormone (GH) in the neonatal period, the effects of GH or insulin-like growth factor 1 (IGF-1) administration were studied in the neonatal GH-defïcient rat. Groups of pups from newborn litters were randomized to receive twice daily subcutaneous injections of recombinant bovine growth hormone (bGH, 5 μg), recombinant human IGF-1 (10 μg) or saline from the second to twelfth day of life. The effects on growth parameters, serum IGF-1 concentration, body composition and hepatic GH receptor binding were assessed. bGH-treated animals showed increases in body weight gain (p = 0.01), serum IGF-1 (p < 0.01), carcass nitrogen (p < 0.001) and carcass water (p < 0.001) compared to IGF-1 or saline-treated animals. No differences in these parameters were noted between IGF-1 and saline-treated groups. bGH-treated animals showed a significantly lower hepatic GH receptor binding (p < 0.01) compared to the other two groups. The demonstration of anabolic responses to GH administration in the neonatal period has implications for the possible role of GH in fetal and neonatal grow

ISSN:1663-2818    

DOI:10.1159/000183791

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

In humans, sex steroids have been implicated in the regulation of hepatic and lipoprotein lipase activity. Therefore, the effects of orchidectomy and subsequent androgen or estrogen administration on hepatic lipase (HL) and adipose tissue and heart lipoprotein lipase (LPL) were examined. Relative to intact controls, orchidectomy of male rats resulted in no significant change in HL activity and mRNA, or in heart and adipose tissue LPL activity and mRNA levels. Subsequently, a subcutaneous silastic tubing, delivering either testosterone, dihydrotestosterone, nandrolone, or 17β-estradiol, was implanted for 5 weeks. All substitution treatments had a tendency to reduce HL activity and to induce HL mRNA levels. This effect was, however, only significant for testosterone which resulted in a decrease in HL activity (238 ± 15 vs. 328 ± 31 mU/g tissue; p vs. control < 0.05) and an increase in HL mRNA (166 ± 11 vs. 100 RAU; p vs. control < 0.01). No significant effects of androgens on LPL expression either in heart or adipose tissue were observed. Adipose tissue LPL activity (20 ± vs. 35 + 4 mU/g; p vs. control < 0.05) and mRNA (28 ± 4 vs. 100 RAU; p vs. control < 0.001) levels, but not heart LPL, however, were diminished substantially after 17α-estradiol treatment. In conclusion, rat HL is influenced by testosterone, while adipose tissue, but not heart LPL, is reduced after estrogen administ

ISSN:1663-2818    

DOI:10.1159/000183792

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The aim of our study was to investigate the effect of a definite schedule of treatment on the growth of children with β-thalassemia major. Ten children (6 girls, 4 boys) participated in this longitudinal study. They were treated with transfusions to maintain the levels of hemoglobin above 10.5 g/dl from the time of diagnosis and desferrioxamine mesylate 40 mg/kg/day by subcutaneous pump, 5 days a week, during 7 ± 1.4 years. The patients were followed up from the age at diagnosis (18.9 ± 9.8 months) until they reached their adult bone age (19.1 ± 1.6 and 20.8 ± 0.8 years in girls and boys, respectively). We observed growth retardation before the age of 10 in 3 out of 4 boys and in 1 out of 6 girls. Between the ages of 10 and 15, the growth failure was evident in other children (1 boy and 2 girls), and became more marked in the above mentioned children. After the age of 15, amelioration of the growth failure was observed in relation to sexual maturity. Eight out of 10 patients attain normal stature in accordance with their target height. We had evidence of poor compliance with the chelation therapy in the 2 children of short adult stature. These patients had higher serum ferritin levels than the children with normal height within the study period: 4,461 ± 1,469 and 1,429 ± 479 μg/l respectively (p = 0.049). Our study reveals a positive effect of intensive chelation therapy on the linear growth in these p

ISSN:1663-2818    

DOI:10.1159/000183793

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

It is now clear that early detection and adequate replacement therapy of congenital hypothyroidism (CH) results in normal growth and psychomotor development. However, there is evidence that some of those infants might have a persistent alteration in the T4 feedback control of TSH release. To characterize further this phenomenon, 25 treated CH children were divided into two groups: group A consisted of children whose TSH was suppressed as early as 1 month after the onset of therapy, and group B consisted of children whose TSH suppression occurred much later. There were no differences in the etiology of CH, in the mean T4 and T3 serum levels or in the mean LT4 treatment dosage between the two groups. All children were clinically euthyroid throughout the follow-up, developed according to expected norms and no deviations were noted in bone age. However, serum TSH levels remained elevated in group B infants throughout the follow-up period (up to 14 years). Increase of LT4 treatment dosage resulted in TSH suppression in both groups. However, the TSH levels obtained in group B were still higher compared to group A. These results suggest that some CH infants might have an abnormal setpoint for T4 control of TSH secretion and that these infants can be detected as early as 1 month after birth. Thus, serum T4, T3 levels and clinical progress are better guides to the adequacy of therapy than serum TSH concentrations in this group of CH infants.

ISSN:1663-2818    

DOI:10.1159/000183794

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Partial thyroxine-binding globulin (TBG) deficiency, with a median TBG of 2.3 mg/l, was found in 25 mature babies with hypothyroxinaemia (3 girls and 22 boys) from our screening programme for congenital hypothyroidism during 1988-1990. Analysis of the HLA system revealed the possibility that antigen DR6 may be considered as a risk factor for TBG deficiency (44.0 vs. 19.2%) and DR2 as a protective factor (16.0 vs. 37.5%). Similar laboratory findings were also present in 16 mothers and 1 father.

ISSN:1663-2818    

DOI:10.1159/000183795

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

A potential relation was evaluated between nocturnal urinary growth hormone (GH) excretion as a parameter for integrated GH secretion and the course of blood glucose (BG) levels during night and morning hours. Twelve diabetic children aged 11.6 ± 2.0 years (mean ± SD), with diabetes duration 4.4 ± 1.6 years, took part in the study. Urine for GH estimation by a highly sensitive EIA was collected from 24.00 to 07.00 h during a diabetic summer camp. BG was monitored at 24.00, 04.00 and 07.00 h. Mean nocturnal GH excretion measured from 158 collections was 5.6 ± 5.1 ng/g creatinine, with a wide range of 0.36-36.6. Remarkable intra-individual variations were found between distinct nights. GH excretion correlated positively with BG levels at 07.00 h (p = 0.003) and with the increment of BG between 24.00 and 07.00 h (p = 0.002). Thus, endogenous variations in nocturnal GH levels may be involved in the day-to-day fluctuations in fasting BG in diabetic subje

ISSN:1663-2818    

DOI:10.1159/000183796

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

In 29 consecutive patients with adrenocorticotropin (ACTH)-dependent Cushing’s syndrome, we compared the usefulness of multiple baseline ACTH evaluations (10/29), multiple hormone evaluation (29/29) and ACTH-releasing hormone (CRH) stimulation (21/29) during simultaneous and bilateral inferior petrosal sinus sampling. The basal inferior petrosal sinus/periphery ratio for ACTH concentrations was greater than 2 in 18 of the 29 patients and CRH challenge caused the appearance of an inferior petrosal sinus/periphery ratio greater than 3 in 6 other patients. The presence of an ACTH-secreting adenoma was surgically proven in all the 24 patients who had an ACTH inferior petrosal sinus/periphery ratio greater than 2 basally or greater than 3 after the CRH test but also in 1 patient who had an inferior petrosal sinus/periphery ratio lower than 2 basally or 3 after the CRH test. In 4 patients, both the very high peripheral ACTH levels, the inferior petrosal sinus/periphery ratio and the complete lack of ACTH increase after CRH indicated the presence of an ectopic ACTH syndrome: a bronchial carcinoid was found in 2 patients, whereas the site of the tumor is still unknown in the remaining 2. An ACTH intersinus gradient greater than 1.4 was found in 23 patients. Among these 23 patients, the side of the adenoma was correctly predicted in 19 patients and wrongly in 4. In the 10 patients receiving ACTH level evaluation three times before performing the CRH test, no difference of ACTH concentrations was detected in 7 either in the periphery or in inferior petrosal sinuses, while in the remaining 3 patients the ACTH inferior petrosal sinus/periphery ratio became greater than 2 indicating Cushing’s disease. The presence of an intersinus gradient greater than 1.4 for β-endorphin was found basally in 19/29 patients (65.5%) whereas after CRH challenge in 21/29 patients. Moreover, in 4/21 patients (19%) it was clearer than the ACTH intersinus gradient in localizing the pituitary adenoma. Furthermore, in 13 patients a significant intersinus gradient, either basally or after CRH challenge, was found also for GH and/or PRL (44.8%) and in 5 patients for TSH, FSH and/or LH (17.3%). All the 4 patients with proven or suggested ectopic ACTH production had no intersinus gradient for whichever pituitary hormone was considered. In conclusion, the diagnostic accuracy of the inferior petrosal sinus sampling in our series was of 96.5% (28/29 cases) when considering basal and CRH-stimulated ACTH levels in the inferior petrosal sinuses and periphery. On the contrary, the multiple basal ACTH evaluation does not seem to be necessary when CRH is performed during the test, but may be helpful in a minority of cases when CRH test is not available. The multiple hormone evaluation, in particular β-endorphin level assay, might be performed in doubtful cases after the ACTH level determination is obtained, as it can help to indicate the presence of a pituitary microadenoma in the majority of pat

ISSN:1663-2818    

DOI:10.1159/000183797

出版商:S. Karger AG    

年代:1993

数据来源: Karger