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Biomedical subjects

O Mehls

Publications and source records attributed to O Mehls.

At least 199 records · Page 11Linked to original sources
PubMed1984

Psychosocial adaptation of children and their parents to hospital and home hemodialysis.

Psychosocial adaptation of 20 children and adolescents treated by regular hemodialysis and their parents was analyzed by detailed semistructured interviews and questionnaires. The results in 10 patients treated in the centre and 10 followed at home were compared. The burdens of patients and parents induced by therapy as well as compliance, educational aspects and school activity in the treated children are described. Home dialysis usually provoked more fears of complications and aggressive feelings in patients and stress in parents but was superior to centre treated patients regarding social contacts and school activity of patients. From the data obtained, a comprehensive programme of psychosocial care for children with end-stage kidney disease was derived, including detailed instruction for parents and teachers of children on regular dialysis treatment.

Adaptation, Psychological↗
PubMed1983

Vasoactive hormones in children with chronic renal failure.

Plasma renin activity (PRA), aldosterone, vasopressin and catecholamines were measured in 15 children (ages 7.3 to 16.2 years) with chronic renal failure (CRF) before and after one session of hemodialysis and in 15 control children. Basal levels of PRA and aldosterone in children with CRF did not differ significantly from control values, but showed a wider range. Uremic patients with nephronophthisis showed the highest basal PRA and aldosterone levels. In children with CRF, basal vasopressin levels were significantly higher (9.7 +/- [SEM] 2.0 ng/liter) than control values (3.2 +/- 0.8 ng/liter). Plasma noradrenalin and adrenalin concentrations were similar in children with CRF and controls. During hemodialysis, a fall in blood pressure and a rise in heart rate was observed in all children. PRA and catecholamines increased twofold to fivefold during dialysis while aldosterone and vasopressin showed a variable response. In contrast to reports in adults, there is no evidence for an insufficiency of vasoactive hormones or of the sympathetic nervous system in children on hemodialysis.

Adolescent↗
PubMed1983

Skeletal growth in experimental uremia.

Although in recent years experimental work on growth in uremia has clarified many issues, many key questions cannot be answered with available experimental data. In our own studies on subtotally nephrectomized rats, uremic animals consumed less food and grew less. However, although low energy intake diminishes growth, it has not been established that high protein energy intake will normalize growth. We showed that uremia reduced growth (and net protein synthesis) even under conditions of controlled food intake. In renal failure the optimal dietary protein level for growth or for efficiency of utilization has not been established, particularly since protein intake has an independent injurious effect on long-term renal function. Calcium and vitamin D supplements improved growth in uremic rats, but the data cannot easily be extrapolated to humans. The growth-promoting action of 1,25(OH)2D3 was not superior to that of equipotent doses of vitamin D3. Correction of anemia and physical exercise did not improve growth. Diminished stimulation of growth cartilage cyclic AMP with PTH and augmented stimulation with calcitonin was noted in uremic animals. Growth hormone in supraphysiological doses improved growth and raised IGF carrier protein in uremic animals. Spermine, a potential uremic toxin, inhibited growth cartilage 3H-thymidine incorporation, but only in concentrations higher than that encountered in uremia.

Animals↗
PubMed1983

Cardiac function in experimental uremia.

In acutely uremic animals, the contractile force of the heart is consistently increased; such an increase can be dissociated from changes of afterload or catecholaminergic drive. It is associated with diminished sarcolemmal Na,K-ATPase activity in the heart which, in turn, may be related to increased levels of endogenous digitalis-like substances (endigens) that have been postulated to represent a natriuretic factor. In patients with chronic uremia, myocardial contractility is usually normal, but occasionally there may be heart failure unrelated to pre-existing hypertension, coronary heart disease, anemia, fluid overload, or other recognizable factors. So far, the experimental basis for this clinical observation is uncertain. Possible causes for the clinical syndrome include an excess of parathyroid hormone or cardiodepressor substances. There is experimental evidence of impaired cardiac response to beta adrenergic agonists, e.g., decreased isoproterenol-dependent calcium uptake, diminished inotropic and chronotropic responses. In acutely uremic rats, cardiac cyclic AMP levels are high but can be reversed by beta blockers. Heart calcium content is variable and heart weight is constantly increased in acutely uremic rats, despite decreased skeletal muscle mass. The change in heart weight is not related to anemia, to an excess of parathyroid hormone, or to sympathetic activity; its cause remains unknown. Experimental studies to date have shown a variety of abnormalities, but do not provide a uniform concept of the mechanisms or an explanation for the cardiac dysfunction so often observed in patients with uremia.

Animals↗
PubMed1983

Prediction of adult height in children with chronic renal insufficiency.

The ability to accurately predict adult height (AH) has important implications for the management of children with chronic renal insufficiency (CRI). Serial predictions of AH were performed for 22 pediatric patients with CRI of variable duration and severity using the Tanner predictive method. The patients were followed until completion of growth. At the first predictions, the prediction error (PE) was within an acceptable range of +/- 2 cm in 59% of the patients. The mean size of the PE was 2.7 cm. It was larger in 7 patients with a bone age up to 11 years (4.9 cm) as compared to 15 patients with more advanced bone age (1.7 cm) and also larger in males (3.4 cm) than in females (2.4 cm). There was no correlation between size or direction of PE and (1) mode of treatment and (2) time elapsed between the first prediction and age at AH. A significant association was found between the direction of PE and the relative change in body height from the first prediction to adult age. Patients with decreasing SD scores were overpredicted and those with increasing SD scores were underpredicted at the initial assessment. Serial predictions gave large variations only in 2 girls who presented with unusual growth patterns. These results indicate that the method applied allows a reliable prognosis of future growth in most children with CRI.

Adolescent↗
PubMed1982

Vascular effects of parathyroid hormone (PTH).

PTH causes dose dependent transient vasodilatation in various vascular beds, specifically renal, coeliac, coronary, but not osseous. It has an acute dose-dependent hypotensive effect in the intact animal which is not mediated by alpha- or beta-adrenergic, cholinergic or histaminergic mechanisms. Aortic medial smooth muscle cells respond to PTH with an increase of cAMP, cGMP and, presumably via protein kinase, with activation of phosphorylase B kinase. The acute vasodilatory effect of PTH is antagonised by indomethacin and diclofenac as well as by ouabain, suggesting that the membrane Na-K pump and prostaglandins are involved in PTH-induced vasodilatation. Parathyroidectomy and a high calcium diet attenuate the rise of arterial pressure in experimental hypertension, pointing to some permissive effect of PTH for development hypertension. This is most likely due to long term effects of PTH on vessel wall calcium content and exchange. This chronic effect of PTH may explain the high prevalence of hypertension in patients with primary hyperparathyroidism.

Animals↗
PubMed1982

Effect of parathyroid hormone, calcitonin and growth hormone on cAMP content of growth cartilage in experimental uraemia.

The response of proximal tibial growth cartilage cAMP content to different hormonal stimuli, i.e. parathyroid hormone, calcitonin and somatotropic hormone was evaluated in rats with bilateral or subtotal nephrectomy. In uraemic rats, basal cAMP content of growth cartilage was unchanged. Administration of 1-34 PTH in vivo or incubation of growth cartilage with 1-34 PTH in vitro caused a significantly smaller increment of cAMP in uraemic rats (40 IU PTH in vivo: 11.4 +/- 1.01 pmol cAMP/mg protein; controls 24.0 +/- 2.55; P less than 0.001). This finding implies PTH resistance. Diminished cAMP response in uraemic animals was not changed by pretreatment with 1,25(OH)2D3 or parathyroidectomy. The increment of cAMP content of growth cartilage of uraemic animals was significantly (P less than 0.01) greater after in vivo administration of 10 IU calcitonin (46.1 +/- 4.89 pmol/mg protein; control: 29.0 +/- 3.99) or incubation of cartilage with calcitonin in vitro. This finding implies overresponsiveness to calcitonin. Neither in acute nor in chronic uraemia, STH caused a significant change of cartilage cAMP or cGMP content, but STH stimulated 3H-thymidine incorporation into chondrocytes of rats with 5 days uraemia (solvent 2.98 +/- 0.51 x 10(3) cpm per cartilage; STH 5.08 +/- 0.34; P less than 0.05) and caused significant improvement of longitudinal growth of rats with 20 days uraemia.

Animals↗
PubMed1981

Virilizing hepatoblastoma--significance of alpha-1-fetoprotein and human chorionic gonadotropin as tumor markers in diagnosis and follow-up.

Hepatoblastoma was diagnosed in a 12 month old boy presenting with hepatomegaly and isosexual precocious puberty. Preoperative levels of both alpha-1-fetoprotein (AFP) and human chorionic gonadotropin (HCG) were highly elevated. The tumor was removed by hepatic trisegmentectomy. Tumor tissue contained high concentrations of AFP and HCG. On combination chemotherapy with cyclophosphamide (CYC), vincristine (VCR), adriamycin (ADR) and 5-fluorouracil (5-FU) HCG dropped over a period of 9 months to normal values. In contrast, AFP was undetectable following surgery. One year after initiation of therapy there is no clinical or radiological evidence of recurrence of the malignancy but the observation period is too short to draw any conclusions on the effect of therapy and the final outcome.

Carcinoma, Hepatocellular↗
PubMed1981

Bone cell kinetics and function during experimental uremia.

Bone cell kinetics and function and chondrocyte kinetics were evaluated in uremic rats and their pair-fed controls using quantitative histology and 3H-thymidine labeling. The principle histologic abnormality in the proximal tibial metaphysis of uremic rats was a relative abundance of proliferating and differentiated bone cells. No mineralization abnormalities were observed. There was increased proliferation of bone cells and an increased rate of differentiation of osteoblasts and osteoclast nuclei in uremic animals. There was no change in chondrocyte kinetics, indicating a dissociation of the normal bone elongation and bone maturation processes. The data on osteoclast number and hard tissue suggest individual osteoclasts in uremic animals have sub-normal resorbing efficiency. It is proposed that the cell kinetic alterations are due to secondary hyperparathyroidism. The cause of osteoclast inefficiency is uncertain, but may be related to (1) deficiency of active products of vitamin D; (2) chronic uremia; and/or (3) chronic secondary hyperparathyroidism.

Animals↗
PubMed1981

[Osteonecroses in children with chronic renal diseases before and after kidney transplantation (author's transl)].

From 1969 to 1980 202 children suffering from chronic renal insufficiency underwent treatment in the Children's Hospital of Heidelberg University. In 36 patients kidney transplantation were performed. Two children developed femoral head necroses before transplantation without corticosteroid therapy. Three patients developed femoral head necroses in one or both sides within one to 24 months after kidney transplantation. All children with femoral head necrosis were suffering from congenital renal disease and had a history of severe renal osteodystrophy which was followed by severe coxa vara. Coxa vara and the resulting faulty loading seem to be essential factors for the development of femoral head necrosis in patients with renal insufficiency before and after kidney transplantation.

Adolescent↗
PubMed1981

Changes in dental development in paediatric patients with chronic kidney disease.

Dental examination of 73 paediatric patients with nephrotic syndrome and 49 with chronic renal failure revealed enamel changes of permanent teeth in about 50%. They consisted usually of white discolorations and hypoplasia of enamel. In nephrotic patients they were observed particularly after the administration of high doses of corticosteroids. In patients with renal failure enamel changes occur very early. Their location was usually compatible with an insult on enamelisation at the time of manifestation of kidney disease. The prevalence of caries was almost twice as high in patients with nephrotic syndrome than in those with renal failure.

Adolescent↗
PubMed1981

Possible role of inorganic sulphate in the pathogenesis of hyperparathyroidism in chronic renal failure.

In order to investigate the role of hypersulphataemia in the development of hyperparathyroidism the blood levels of inorganic sulphate (SO4(2-)) and phosphate (HPO4(2-)) were compared with total and ionised calcium (Ca) and parathyroid hormone (PTH) in 20 patients with chronic renal failure (CRF). There was a positive correlation between plasma SO4(2-) and serum creatinine. Ionised Ca was inversely correlated with HPO4(2-), SO4(2-) and PTH, respectively. The best correlation was found between ionised Ca and the ion product of HPO4(2-) and SO4(2-). It is suggested that hypersulphataemia might be involved in the pathogenesis of secondary hyperparathyroidism and osteodystrophy in CRF by complex formation with Ca, thereby aggravating the effect of HPO4(2-) on ionised Ca and the resulting PTH stimulation.

Adolescent↗