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Biomedical subjects

W M Teller

Publications and source records attributed to W M Teller.

At least 19 recordsLinked to original sources
PubMed1992

Collagen metabolism in cultured osteoblasts from osteogenesis imperfecta patients.

Collagen produced in vitro by bone cells isolated from 19 patients with different forms of osteogenesis imperfecta (OI) was analysed. Clinically, four patients were classified as OI type I, 10 patients as OI type III and five patients as OI type IV. Bone cells of 12 of the 19 OI patients produced structurally abnormal type I collagen. Electrophoretically uniformly slower migrating collagen type I alpha-chains were found in one case of OI type I, in seven cases of OI type III and in one case of OI type IV; two cultures of OI type III produced two different populations of collagen type I alpha-chains, and one culture of OI type IV showed reduction-sensitive dimer formation of alpha 1(I) chains, resulting from the inadequate incorporation of a cysteine residue into the triple helical domain of alpha 1(I). Quantitative analysis of collagen metabolism led to the distinction of two groups of cultured OI osteoblasts. In osteoblasts of OI type I, mainly production of collagen was decreased, whereas secretion, processing and pericellular accumulation of (pro)collagen type I was similar to that in control osteoblasts. In contrast, in osteoblasts of OI types III and IV, production as well as secretion, processing and pericellular accumulation of (pro)collagen type I were significantly decreased. Low levels of type I collagen were found irrespective of the presence or absence of structural abnormalities of collagen type I in all OI types.

Adolescent↗
PubMed1992

Androgen metabolism assessment by routine gas chromatography/mass spectrometry profiling of plasma steroids: Part 1, Unconjugated steroids.

Using gas chromatography/mass spectrometry we have developed a method for the simultaneous determination of six plasma steroids: testosterone, 4-androstenedione, 17 alpha-hydroxyprogesterone, 5 alpha-androstane-3 alpha,17 beta-diol, 5 alpha-dihydrotestosterone, and dehydroepiandrosterone. For each analyte, a deuterium-labeled internal standard was used for quantification. Due to the high isotopic purity of our standards, no complex corrections for isotope contributions were necessary. The procedure provides a sensitive and specific technique with good accuracy and precision.

17-alpha-Hydroxyprogesterone↗
PubMed1992

Defective stimulation of proliferation and collagen biosynthesis of human bone cells by serum from diabetic patients.

We studied the influence of fasting serum from nine insulin-dependent diabetic children and adolescents under insufficient metabolic control on normal human bone cells in vitro compared with serum from eight sex- and age-matched controls. Cell number 24 h after plating was significantly less under diabetic serum, indicating impaired cell attachment, spreading and initiation of cell proliferation. Cell number after five days was reduced by 1% diabetic serum, while higher serum concentrations had diverging effects on osteoblast proliferation. Collagen synthesis of human osteoblasts was significantly reduced by 8% diabetic serum compared to 8% control serum, while synthesis of non-collagenous proteins was not affected. Duration of diabetes (several weeks up to 12 years) had no influence on these parameters. The serum from one patient, which was studied a second time under excellent metabolic control three months later, however, had lost its inhibitory influence on collagen synthesis of osteoblasts. The pattern of the interstitial collagen types I, III and V was not altered by diabetic serum. These results indicate that defective regulation of proliferation and collagen synthesis of osteoblasts by components present in human diabetic serum may be an important factor in the development of diabetic osteopenia. The negative influence might be explained in part by reduced levels of IGF-I and elevated levels of IGF binding protein-1 in the diabetic sera.

Adolescent↗
PubMed1979

Hemoglobin A1c (HbA1c) in children with long standing and newly diagnosed diabetes mellitus.

In 35 children with long-standing diabetes mellitus, a significant correlation was found between the hemoglobin A1c (HbA1c)--and the 24-hour urinary glucose excretion. By contrast, 11 newly diagnosed diabetic children had grossly elevated HbA1c-concentrations, but no correlations could be established between the levels of HbA1c and the duration of symptoms, blood glucose, glycosuria, ketonuria and the acid--base status. However, HbA1c and C-peptide were significantly correlated. The elevated HbA1c-concentrations decreased towards normal in all of these 11 children after 2--3 months following adequate therapy. The results suggest that the determination of HbA1c may serve as a valuable metabolic control index in children with long-standing diabetes mellitus, but adds little information in newly diagnosed patients. For the individual diabetic child during the early treatment period, HbA1c may be the index of choice for adequacy of metabolic control.

Acid-Base Equilibrium↗
PubMed1978

The effect of cyproterone acetate on adrenal cortical function in children with precocious puberty.

8 children with precocious puberty were treated with cyproterone acetate (CPA). During treatment there were no definite clinical signs of depressed adrenocortical function. The plasma cortisol concentrations were grossly depressed and the diurnal cortisol rhythm was abolished. Two months after discontinuation of CPA treatment the adrenocortical function had greatly improved. The lysin-vasopressin stimulation test revealed in one child a normal, in another child an exaggerated ACTH response during CPA therapy. Fasting plasma ACTH concentrations were elevated compared with normal controls, but they were very low compared with patients with Addison's disease. The results suggest that CPA has a twofold effect leading to adrenocortical insufficiency: i.e., inhibition of cortisol secretion by the adrenals themselves and inhibition of ACTH secretion at the hypothalamopitiuitary level.

Adolescent↗
PubMed1978

Insulin secretion in growth hormone-deficient children and the effect of the sulfonylurea drug glibenclamide on linear growth.

The effect of glucose on insulin release and the influence of glibenclamide on linear growth were determined in five growth hormone (STH) deficient children who were treated with human growth hormone. It was found that the administration of 5 I.U. of human growth hormone twice a week improved the defective insulin secretion while prolongation of the week improved the defective insulin secretion while prolongation of the interval between growth hormone injections to 7 days had no effect on beta-cell function. The addition of treatment with 5 mg/day glibenclamide to the regular human growth hormone injections resulted in an increased growth rate in four children while one patient developed hypoglycemic symptoms. The results show that STH-deficient children may benefit from combined treatment with human growth hormone plus glibenclamide.

Adolescent↗
PubMed1978

Analysis of banding patterns and mosaic configurations in a case of ring chromosome 15.

Cytogenetic studies on lymphocytes from a 14-year-old mentally retarded girl with somatic anomalies suggestive of a chromosomal abnormality revealed a ring chromosome 15. The long arm of the defective chromosome is broken at band q24 or q25. The silver staining technique for nucleolus organizer regions showed that the ring had lost the achromatic stalk and the satellite. The chromosomal mosaicism resulting from the structural instability of the ring chromosome was analyzed and compared with 6 cases reported in the literature. It is proposed that the clinical manifestations in the different patients with ring chromosome 15 result from both the deficiency in the long arm and the mosaic configurations.

Adolescent↗
PubMed1978

C-peptide secretion during the remission phase of juvenile diabetes.

C-peptide secretion was studied in eight juvenile diabetics during the remission phase of the disease. The release of C-peptide was measured after a (1) normal intravenous glucose tolerance test, (2) a double glucose tolerance test, (3) an arginine infusion, and (4) after an intravenous glucose tolerance test followed by an arginine infusion. Under all conditions the intravenous glucose load had only a minimal effect on the secretion of C-peptide, while arginine alone or after the intravenous glucose tolerance test stimulated the release of the peptide in all patients. Pretreatment with glucose did not augment the effect of arginine on C-peptide release. The results indicate that during the remission phase of juvenile-onset diabetes the endocrine pancreas does not recognize glucose as and appropriate signal for C-peptide release and cannot transform the amplifying effect of glucose into a higher hormonal secretion rate.

Adolescent↗
PubMed1978

[Osteogenesis imperfecta. Classification with new aspects for pathogenesis and therapy (author's transl)].

The current state of knowledge about osteogenesis imperfecta (O. i.) is reported. According to the course of the disease and the time of onset of first sym8ptoms two types of O. i may be recognized: O. i congenita (O. i. c.) and tarda (O. i. t.). O. i. c. is associated with a more severe course which may lead to extreme skeletal deformities. O. i. t. is characterized by a much milder course. It may exist almost unrecognized. Recent biochemical investigations of collagen revealed that in O. i. quantitative and qualitative abnormalities exist in the synthesis of collagen. Abnormally synthesized collagen is produced in total amounts less than normal. This fact leeds to changes of the physical properties of the connective tissue in cases of O. i. The letest attemp to treat O. i. is the application of calcitonin. This is expected to improve the mineralisation of the skeleton and to decrease the fragility of bones. So far, only reports about shortterm follow-ups during this treatment have been reported. Therefore, a conclusive statement about the validity of therapy with calcitonin can as yet not be given.

Adolescent↗
PubMed1977

Application of glass capillary gas chromatography to the study of urinary steroid excretion in normal children and in patients with various endocrinopathies.

A method of gas chromatography on glass capillary columns (g. c. c. c.) is presented which allows the determination of 26 urinary C19 and C21 steroid metabolites in one procedure. Hundredthirtyseven normal individuals of both sexes from 6 months through 32 years of age were studied regarding their urinary steroid patterns. These were compared to the excretion patterns of patients with congenital adrenal hyperplasia before and during treatment and of a child with virilizing adrenal carcinoma. From the results it is concluded that g. c. c. c. may be considered a valuable tool in the study of steroid production and metabolism.

Adolescent↗
PubMed1977

[Recent progress in research on the central regulation of growth hormone secretion (author's transl)].

The secretion of pituitary and peripheral hormones is regulated by a chain of reactions in the central nervous system. According to current knowledge this chain consists of the following links: external and internal stimuli leads to mesencephalon leads to limbic system leads to monoaminergic neurones leads to hypothalamic nuclei leads to liberines (releasing hormones) and inhibines (inhibiting horomones) leads to portal system leads to pituitary leads to peripheral endocrine gland. Long-loop and short-loop feedbacks regulate the activity of this relay system. The monoaminergic neurones secrete neurotransmitters, of which three are presently known: norepinephrine, dopamine, and serotonin. Most likely there also exists a cholinergic neurotransmitter. The secretion of neurotransmitters can be increased or reduced by specific drugs. On this basis, certain neuroendocrinopathies, such as deprivation dwarfism, hypothalamic acromegaly, and anorexia nervosa, may be treated speciafically. The pituitary secretion of growth hormone (GH) takes place mainly at night during deep sleep (slow-wave-sleep). This secretory pattern develops during the first year of life. It reaches its peak during puberty. At that time GH-spikes also occur during daytime. During adulthood GH secretion slowly diminishes again and at senescence it corresponds to early childhood.

Acromegaly↗
PubMed1976

A test for heterozygocity of 21-hydroxylase deficiency: preliminary report.

The urinary excretion of steroids was studied in 8 parents of children with congenital adrenal hyperplasia due to 21-hydroxylase deficiency of the simple virilizing and of the salt-losing type. Eight parents of normal children served as controls. 24-hour urines before and after the injection of 40 IU of ACTH were fractionated using gas liquid chromatography on glass capillary columns. Before stimulation no excretion of pregnanetriolone was detected in heterozygous and in normal parents. Following ACTH only heterozygotes showed an excretion of pregnanetriolone in the urine. This averaged 289 mug per 24 h. Employing gas liquid chromatography on glass capillary columns heterozygous carriers of congenital adrenal hyperplasia due to 21-hydroxylase deficiency may reliably be detected by their increased urinary excretion of pregnanetriolone following ACTH.

Adrenocortical Hyperfunction↗