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Biomedical subjects

R Wahl

Publications and source records attributed to R Wahl.

At least 127 records · Page 7Linked to original sources
PubMed1978

[A model for the adsorptive distribution of thyroid hormone in the cell (author's transl)].

Mitochondria from rat livers were suspended in solutions of cytoplasmic proteins ("cytosol") containing 0.5--4.7 g total protein per liter suspension. In these suspensions the adsorptive distribution of radioactive 3,5,3'-L-triiodothyronine was studied in the concentration range between 0.04 and 0.50 nmol/1. The experiments show that the distribution of the hormone between the liquid phase of the cytosol and the solid phase of the mitochondria depends mainly on the protein concentrations in both phases. The mathematical formulation of this distribution equilibria which is also applicable to thyroxine corresponded closely with the experimental findings. The processes of the adsorptive binding of thyroid hormones to cell proteins observed in vitro are thought to represent part of a transport chain that exists between different compartments in vivo. The consequences of these considerations on the transport of thyroid hormones within the cell are discussed.

Animals↗
PubMed1978

[Approach to a differentiated recurrence prevention following struma surgery].

Changes of the pituitary-thyroid axis were studied in 70 patients (45 with euthyroid goiters, 25 with autonomous adenomas) preoperatively; over a 6-week postoperative interval without thyroid-hormone treatment; under T4 therapy increased stepwise and maintained for 1 year; and over a period of 12 weeks after its withdrawal. The postoperative thyrotropic function obviously depends on the preoperative condition and thereby on the quality of the remaining tissue as well as on the extent of the operation and thus the amount of remaining tissue. The frequency of a "prehypothyroid" status in the early postoperative course is high (77%) after bilateral resection for euthyroid goiter, but decreased 1 year after the operation (47%). After unilateral resection for euthyroid goiters and after bilateral and unilateral resection or enucleation for autonomous adenomas, the remaining tissue is for the most part sufficient to avoid increased pituitary stimulation. Prophylaxis of recurrent goiter with thyroid hormones could be prescribed individually on the basis of the postoperative function of the pituitary-thyroid axis.

Adenoma↗
PubMed1977

Adsorption equilibria of thyroid hormones in the liver cell.

The adsorptive distribution of L-thyroxine and L-triiodothyronine at 0.04--25nM concentrations was determined in suspensions of mitochondria in soluble cytoplasmic proteins from rat livers, at protein concentrations of 0.5--4.7 mg total protein/ml suspension. In the concentration ranges measured no saturation of both mitochondria and soluble proteins with thyroid hormones could be observed. The distribution of the hormones between the liquid phase of cytoplasmic proteins and the solid phase of the mitochondria depended mainly on the ratio of the amounts of proteins in both phases. Certain drugs such as chlorpromazine and phenobarbital in concentrations used therapeutically can interfere with the processes of adsorptive transport in vitro. Chlorpromazine, in the presence of desorptively functioning cytoplasmic proteins or serum proteins, promotes the adsorption of thyroxine and triiodothyronine onto the mitochondria. In contrast, phenobarbital weakens the binding of the hormones to the mitochondria. The processes of adsorptive binding of thyroid hormones to cell proteins in vitro are suggested as possible links in a transport chain between different compartments in vivo. The new model may also explain the effect of drugs on the distribution of thyroid hormones within the cell.

Adsorption↗
PubMed1977

[Therapy of malignant tumors of the thyroid].

Early detection is still the most urgent concern for the successful treatment of carcinoma of the thyroid. A considerable obstruction to early tumor recognition in Germany is the still much too frequently recorded "endemic goiter". A consistent general goiter prophylaxis by iodization of the domestic salt may also have a favorable influence on tumor diagnosis. The basis for an exhaustively planned treatment of "struma maligna" is the histomorphological classification of tumors. By radical surgical intervention and the selective application of isotope and megavolt irradiation and obligatory prescription of thyroid hormone the treatment results, especially in the differentiated thyroid carcinomata, can be improved to 10-year survival rates of more than 85%.

Humans↗
PubMed1977

[Radical thyroidectomy for malignant thyroid tumour: prognosis and complications (author's transl)].

270 patients were operated on for malignant thyroid tumour between 1955 and 1974. Before 1967, less radical methods of operation had been preferred, but since 1968, radical thyroidectomy - if necessary supplemented by selective or radical neck dissection - has become the procedure of choice if a curative operation was still feasible. This has brought about a significant fall in the incidence of recurrences and increased the survival rate in patients with well-differentiated carcinoma. The proportion of postoperative complications has been within reasonable bounds. The incidence of postoperative recurrent-nerve paralysis, at 9.4%, has not been raised by radical procedures, while the proportion of permanent tetany (11%) after radical thyroidectomy is much higher than after sub-total resection (2%). But the advantages of radical thyroidectomy outweigh the increased incidence of postoperative hypoparathyroidism.

Adolescent↗
PubMed1977

[Diagnostic and therapeutic aspects of endothoracic goiter (author's transl)].

Among mediastinal tumors requiring operative treatment endothoracic goiters have to be considered as common cause (13.7%) in differential diagnostic aspects next to dysontogenetic and neurogenic tumors. Final diagnosis is best established by chest x-rays in two directions, perhaps with additional barium swallow and a scintigraphy (131I or technetium). Angiography is of no valuable further information concerning tumor identification or operability. The disadvantage refers to unwanted iodine load in case of thyroid malignancy. The operative approach for real mediastinal goiter necessitates partial or total sternotomy or occasionally lateral thoracotomy.

Diagnosis, Differential↗
PubMed1977

[Hormone concentrations in thyroid gland tissue and plasma in autonomous thyroid adenomas with and without thyrostatic pretreatment].

The thyroid hormone concentrations of T2, T3 (and the inactive R-T3) were determined in thyroid tissue of 20 patients with autonomous adenomas. High concentrations were found in scintigrafically decompensated adenomas without preoperative thyrostatic treatment. Decompensated adenomas after thyrostatic treatment, compersated adenomas and a group of 9 euthyroid goiters showed no difference in tissue-concentrations of T4 and T3. The amount of tissue-R-T3 seems to be lowered in autonomy. The plasma-concentration of T3, which was intraoperatively elevated in the venous effluent from decompensated adenomas without thyrostatic treatment, was significantly lower in the blood draining decompensated adenomas after thyrostatic treatment as well as compensated adenomas.

Adenoma↗
PubMed1976

[Surgical aspects of secondary hyperparathyroidism (author's transl)].

Between 1969 and April 1975 24 patients with severe secondary hyperparathyroidism (sHPT) clinically presenting with uremic osteopathy required either total (n=5) or subtotal (n=18) parathyroidectomies, 17 patients were already supported by maintenance hemodialysis, 6 patients suffered from terminal renal insufficiency. The leading clinical symptoms consisted of general osteoporosis, spontaneous fractures, extraosseous calcifications and histologically proven dissecting fibroosteoclasia. After operation 18 patients experienced complete relief from their complaints and repair of their skeletal lesions, 2 patients required reexploration for an undetected hyperfunctioning 4th parathyroid gland, regretfully with no success. In 4 patients with subtotal parathyoidectomy a recurrence of varying intensity with increased PTH-secretion from the remnant had to be registered after months and years.-The indication for surgical treatment of sHPT due to chronic renal failure has to be based on two sets of findings: 1) inadequate longterm suppression of increased PTH secretion by conservative measures like high dialysate calcium concentration or oral calcium intake, serum phosphorus depletion by oral intake of aluminium hydroxyde and possibly also by Vit. D; 2) persistent hypercalcemia, progressive osteodystrophy and severe complaints like bone pain and pruritus.

Adult↗
PubMed1976

[Restitution of the thyrotropic function in goiter patients after discontinuing a long-term suppression therapy with thyroid hormones].

27 subjects with a negative TRH test were selected among patients with euthyroid goiter treated by thyroid hormones. The hormone therapy was stopped and T3 and T4 concentrations, basal and TRH stimulated TSH levels were determined after one, two and four weeks. A gradual increase of the mean basal and TRH stimulated TSH plasms concentration could be observed. However, after four weeks the TRH test was still negative in two patients and weak positive in another case. T3 plasma levels were lowest after one week which might indicate the presence of an intermittent thyrotropic insufficiency. It is concluded that the hormone-free interval should last four weeks at least before a reliable TRH test can be obtained.

Goiter↗
PubMed1976

[25-OH-vitamin D in the serum of patients with femoral-neck fractures].

In 10 women with femoral neck fracture, 10 with fracture(s) evolved from accidents (mainly traffic accidents) and 10 without disease (controls) in January and July, the 25-OH-vitamin D levels in serum were measured by a competitive protein binding assay. Patients with femoral neck fractures exhibited significantly (p less than 0.05) lower 25-OH-vitamin D levels than the other groups. Additionally, in patients with femoral neck fractures calcium x phosphate product in serum was subnormal (below 25). In Germany, prophylactic dietary supplementation of vitamin D seems feasible.

Aged↗
PubMed1976

[Secretion of TSH and stimulation-ability of the hypophysis after long-term suppression therapy in euthyroid nodular goiter and residual thyroid gland after subtotal resection of goiter].

In 51 patients, 33 with euthyroid goiter and 18 after subtotal thyroidectomy, plasma concentrations of T4, T3, and TSH before and after stimulation with TRF were determined under long term suppression with thyroid hormone and 1,2, and 4 weeks after stopping it. Even after complete suppression (delta TSH less than 0, 5 muU/ml) resumption of TSH secretion occurred within 4 weeks in all but two. A significantly higher increase of TSH and somewhat lower thyroid-hormone concentrations turned out in operated patients. An excessive decrease of T3 (and T4) concentrations within the 1st (and 2nd) week after therapy, dependent on the degree of previous TSH suppression, could be due to transitory thyrotropic insufficiency.

Goiter, Nodular↗
PubMed1975

[Evaluation of reliable pituitary suppression therapy through varying thyroid hormone dosage following total thyroidectomy due to a differentiated thyroid carcinoma].

The reliability of pituitary suppression by administration of 1-thyroxin (t4) or a combination of thyroxin and triiodothyronin (t3) of variable dosage following radical surgery for thyroid cancer in 13 patients was investigated by means of TRH-test and measurement of serum hormone levels. In contrary to generally applied higher doses the results were able to demonstrate that 0.2 to 0.3 mg 1-thyroxin is a sufficient dosage for a complete suppression of TSH-stimulation. In the presence of obviously more side effects the treatment with a combination of t4 and t3 is not of any advantage.

Carcinoma↗
PubMed1975

[Phagocytosis of group A haemolytic streptococci by mouse macrophages. Comparison of preliminary infection of animals and degree of virulence of the strain (author's transl)].

With the aim of studying immunological reactions associated with experimental streptococcal diseases, we have developed an in vitro technique for following phagocytosis of streptococci by peritoneal macrophages of mice. By this means we have been able to show that the rate of phagocytosis of streptococci by "normal" macrophages is inversely correlated to the degree of virulence of the strain. On the other hand, the rate of phagocytosis of the virulent strain is increased 10 times when the macrophages come from mice having previously been injected with this virulent strain.

Animals↗