Exploration of the somatotropic axis.
Explore the source record for details and available documents.
Diabetes Mellitus, Type 1↗
Biomedical subjects
M Tauber
Publications and source records attributed to M Tauber.
Insulin therapy and GH-IGF-I axis disorders in diabetes: impact of glycaemic control and hepatic insulinization.
In Type 1 diabetes, high circulating growth hormone (GH) in conjunction with low plasma insulin-like growth factor-I (IGF-I) is indicative of a hepatic GH-resistance profile since the liver is the main source of circulating IGF-I. The reduction in specific growth hormone binding protein (GHBP), corresponding to the extracellular domain of the GH receptor, provides an indirect indication of the hepatic density of GH receptors, as does the reduction in IGFBP-3, the major IGF binding protein, which is GH-dependent. Type 1 diabetes is also associated with high levels of IGFBP-1, a binding protein down-regulated by insulin. Although most of these abnormalities have been described in situations of poor glycaemic control, hyperglycaemia does not seem to be the predominant factor in their pathogenesis. Even intensified subcutaneous insulin therapy does not normalize GH, IGF-I, GHBP and IGFBP-3 plasma levels. Some indirect evidence suggests that portal insulinopenia plays a role in the hepatic GH-resistance profile of Type 1 diabetes, i.e. discrepancies between the abnormalities reported in Type 1 and Type 2 diabetes, and the inverse relationship between residual insulin secretion in Type 1 diabetes and some of these abnormalities. Intraperitoneal insulin therapy administered to Type 1 diabetic patients by implantable pumps (without modification of glycaemic control) can improve GHBP activity, practically normalize plasma IGF-I and normalize IGFBP-3. The improvement in GH-IGF-I axis disorders obtained with intraperitoneal insulin therapy (which allows primary portal insulin absorption) provides direct evidence of the central role of portal insulin in the regulation of this system.
Blood Glucose↗
Growth hormone secretion in children and adolescents with familial tall stature.
Sixty-five patients (22 boys and 43 girls) presenting with familial tall stature were investigated with regard to growth hormone (GH) secretion, both physiological and after stimulation with thyrotropin releasing hormone (TRH) and growth hormone releasing hormone (GHRH). Plasma insulin-like growth factor-I (IGF-I) was also measured. Two groups of patients were distinguished according to their physiological secretion of GH: a high secretory group (n = 49) with a mean 24 h integrated concentration of GH (IC-GH) of 5.4 +/- 2.3 micrograms/l per minute and a large number of peaks (5.1 +/- 1.6 in 24 h), and a low secretory group (n = 16) with a mean 24 h IC-GH of 2.1 +/- 0.5 micrograms/l per minute and few peaks (3.3 +/- 1.3 in 24 h). Plasma IGF-I levels and GH peak values after the TRH test were significantly higher in the high secretory group. These results indicate that familial tall stature is the consequence either of hypersecretion of GH or of hypersensitivity to this hormone (IGF-I levels being normal in spite of low GH levels).
Adolescent↗
Differential regulation of serum growth hormone (GH)-binding protein during continuous infusion versus daily injection of recombinant human GH in GH-deficient children.
Serum GH-binding protein (GHBP) was evaluated in 2 randomly divided groups of prepubertal children presenting with idiopathic GH deficiency and receiving recombinant human GH, either continuously by sc infusion (group 1) or as 1 daily sc injection (group 2). After the first 6 months, group 1 switched from continuous infusion to daily injections for the following 6 months. There was no significant difference in clinical data, GH values, or GHBP levels between the 2 groups before treatment. During the first 6 months, GHBP levels increased in all except 1 of the 8 children in group 1 from 8.6% to 16.9% after 3 months and 22.5% after 6 months. The increment factor ranged from 1.1-7.9, with wide individual variations. In group 2, the mean variation in GHBP was from 8.3-8.2% after 3 months and 10.7% after 6 months. Only 2 of the 10 children in this group showed a significant increase in GHBP levels. During the second period, group 1 maintained their GHBP levels, whereas the 2 children in group 2 tended to a continued increase in their GHBP levels. There was no correlation with the increase in growth velocity, as children in both groups grew equally well, but higher insulin-like growth factor-I levels were found in group 1, although the difference between the two groups was not significant. These data show that GH can increase GHBP levels and that there is a differential effect depending on the mode of GH administration, although the reason for and the role of such regulation remains to be explained.
Carrier Proteins↗
Immunoscintigraphic localization of renal tumours in an extracorporeal perfusion model with a monoclonal antibody against gamma-glutamyltransferase.
Monoclonal antibody 138H11 against human gamma-glutamyltransferase has been shown to react immunohistochemically with 98% of all tested clear-cell type and chromophilic renal cell carcinomas, but not with renal chromophobic carcinomas, Duct-Bellini carcinomas or oncocytomas. In normal kidney the target epitopes of mAb 138H11 are located in the luminal brush-border membrane of proximal tubule cells, whereas in renal carcinomas the epitopes are found surrounding the whole tumour cells. These results form the basis of the present immunoscintigraphic study designed to evaluate mAb 138H11 in an extracorporeal perfusion model. Immediately after nephrectomy, human tumour-bearing kidneys were perfused with 99mTc-labelled mAb 138H11 in Euro-Collins solution. High specific uptake in 4/4 renal clear cell carcinomas could be demonstrated by planar immunoscintigraphy and single-photon-emission computed tomography, "regions of interest" investigation and immunohistochemistry. In contrast, a perfused oncocytoma showed up as an unlabelled lesion. The results indicate a possible use for mAb 138H11 in immunoscintigraphy or even therapy, provided high tumour uptake can be confirmed in patients.
Adenocarcinoma↗
Investigation of growth hormone secretion in patients with intrauterine growth retardation.
Growth hormone (GH) deficiencies have rarely been reported in intrauterine growth retardation (IUGR). This study has investigated GH secretion using GH provocation tests, 24-hour GH secretory profiles, and insulin-like growth factor I (IGF-I) measurements in 24 children with intrauterine growth retardation. The criteria for diagnosis were a birth length and weight below the 10th percentile for gestational age. The average age at investigation was 5.5 years, and the average growth retardation was -3.3 SD. Twenty children had shown catch-up growth between the ages of 6 months and 3 years, followed by varying decreases in growth velocity. Studies of GH secretion demonstrated GH deficiency in 16 patients, with neurosecretory dysfunction in six. Treatment with pituitary GH in nine children increased mean growth velocity from 3.5 cm/year to 7 cm/year. GH therapy should thus be effective in improving the height prognosis of children with intrauterine growth retardation.
Child↗
[Treatment of growth hormone deficiencies by GHRH].
Production of growth hormone is directly stimulated by a hypothalamic factor, called GHRH. This factor, that was first isolated in 1982, has now been synthetized and is under study for the treatment of growth hormone deficiencies due to hypothalamic dysfunction. A wide range of dosages have been used (3 to micrograms/kg/d); administration has usually been by subcutaneous injections, but continuous or pulse pump infusions have been used. In most series, GHRH treatment has been followed by increases in growth velocities; however, individual responses have varied widely, with some patients being "responders" and others "non-responders". No accurate criteria for differentiating responders from non-responders prior to treatment have as yet been identified. Studies of growth hormone secretion during treatment have usually evidenced a moderate increase both in the response to the GHRH test and in C/IGF I somatomedins. Investigations for anti-GHRH antibodies have been negative in most instances. GHRH treatment still raises many unanswered questions, including the effective dosage, exact indications, and mode of administration. Further studies are therefore needed before use of GHRH can become widespread.
Child↗
[Radiation sterilization of contact lenses].
Explore the source record for details and available documents.
Contact Lenses↗
[Idealization of the father: a necessary consequence in divorce families?].
In a sample on 243 adolescents, it was investigated whether idealization is a necessary consequence for adolescents experiencing parental divorce. Earlier studies emphasized the negative effects of parental divorce on the development of children and adolescents. Due to historic changes in family structure, however, parental divorce has to be conceptualized in more positive terms. In the study presented, idealization of the non-custodial father was only found in a clinical subsample of adolescents, whereas the father-adolescent relationship in non-clinical adolescents from divorced families did not differ significantly from the quality of relationship described by non-clinical adolescents living in two-parent families. The function of idealization in coping with negative affects such as aggression and affliction is discussed, in particular for those adolescents in the clinical sample who rarely have contact with their non-custodial fathers, and the contributions of fathers to hold up this idealization outlined. Idealistic conceptions in adolescents of divorced parents are especially problematic, since adolescents are expected to become disengaged of their parents and develop a mature and realistic perception of them.
Adolescent↗