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Biomedical subjects

M Weissel

Publications and source records attributed to M Weissel.

At least 109 records · Page 6Linked to original sources

Starvation induces a partial failure of triiodothyronie to inhibit the thyrotropin response to thyrotropin-releasing hormone.

During starvation the response of TSH to TRH decreases in many subjects. This could be due to an increased sensitivity to TSH secretion to circulating thyroid hormones. To study this hypothesis, 13 subjects were starved twice for 2-day periods. After both starvation periods, a standard TRH test (200 micrograms TRH, iv) was performed; during 1 starvation period 15 micrograms T3 were injected iv 24 h before the TRH test. The TRH tests were also performed while on normal nourishment, once without pretreatment and once 24 h after the iv injection of 15 micrograms T3. The spontaneous decrease of the TSH response to TRH was seen in 10 of 13 subjects. In these 10 subjects it decreased from 18.0 +/- 1.9 to 9.7 +/- 1.2 microU/ml (mean +/- SEM; P < 0.001). The additional inhibition of the TRH test with T3 was small compared with the one observed under normal conditions. In starvation, T3 decreased the maximal TSH response from 9.7 +/- 1.2 to 8.4 +/- 1 microU/ml (P = NS), while during the control period the maximal TSH response fell from 18.0 +/- 1.9 to 11.4 +/- 1.3 microU/ml (P < 0.001). These data indicate a diminished effectiveness of T3 in inhibiting TSH secretion and are consistent with the hypothesis of a more generalized resistance of target organs to T3 during starvation in man.

Adult↗

[The biological classifications of malignant thyroid tumours (author's transl)].

Carcinomas of the thyroid gland display large pathological and clinical variation. Favourable prognostic factors accompary well-differentiated tumours, whereas poorly differentiated or anaplastic carcinomas tend to invade early and are usually rapidly fatal. Experience has demonstrated the difference in rate of growth, subsequent recurrence and late spread even in identically well-differentiated thyroid carcinomas. Biological difference must be the underlying reason for the clinical difference in behaviour of histologically similar cancers. This report demonstrates the correlation between in vivo radioactive iodine uptake, tumour staging and recurrence-free interval in 30 thyroid carcinomas. The uptake by well-differentiated carcinomas staged T2N0M0 is significantly higher than that by tumours staged T3N1M0, whereas the latter show a higher uptake than those tumours staged T3N1M0. A high tumour uptake rate is correlated with long recurrence-free interval (up to 24 months) within all groups of staging and vice versa.

Humans↗

[Vitiligo from p-tert. butylphenol; a contribution to the problem of the internal manifestations of this occupational disease].

10 worker suffering from occupational vitiligo due to p-tert. butyl phenol have been observed in an Austrian resin factory. The dust concentration and its content of p-tert. butyl phenol in the working area were measured. On the basis of these results preventive measures were taken to reduce the exposure of the workers to p-test butyl phenol. In the presented cases an involvement of internal organs--as described by Rodermund et al. (1975)--could not be observed.

Air Pollutants, Occupational↗

[Serum concentrations of thyroid hormones in severe non-thyroidal illnesses (author's transl)].

Pathologically low serum total triiodothyronine (T3) concentrations are a characteristic finding in patients with severe non-thyroidal illnesses. No adequate explanation has yet been offered for this phenomenon. We have, therefore, investigated the serum concentrations of total thyroxine (T4), total T3 and total 3,3',5'-triiodothyronine (reverse T3)--the metabolically-inactive metabolite of thyroxine--and of TSH in 13 patients with acute myocardial infarction, in 12 patients with compensated liver cirrhosis, in 9 patients with decompensated liver cirrhosis and in 15 patients with chronic renal failure on chronic intermittent haemodialysis by radioimmunoassay. The values obtained were compared to corresponding values of a normal control group (n - 23). According to our results the decrease in serum T3 combined with normal T4 concentrations in severe non-thyroidal illnesses seems to be a consequence of an alteration in thyroxine degradation. Two different possibilities of alteration can be considered: 1. inhibition of the overall deiodinationof T4, leading to low total T3 serum concentrations with concomitant normal to low reverse T3 serum concentrations (chronic uraemia), 2. a shift in the monodeiodination of T4 towards enhanced reverse T3 production, leading also to low total T3 concentrations, but with a concomitant increase in reverse T3 serum concentrations (myocardial infarction, liver cirrhosis). The results obtained in our patients with liver cirrhosis show, moreover, that this alteration of T4 metabolism depends on the severity of the illness.

Humans↗

[Pseudohypoparathyroidism type I and vitamin D therapy].

In pseudohypoparathyroidism type I pharmacologic dosis of vitamin-D can correct hypocalcemia. Several authors who had investigated vitamin-D-metabolism in these patients, found impaired renal conversion of 25-hydroxyvitamin-D to 1,25-dihydroxy-vitamin-D. Treatment of 2 patients with pseudohypoparathyroidism type I with vitamin-D-3 and 1 alpha-Hydroxycholecalciferol consecutively resulted in a nonuniform response with regard to the normalisation of serum-calcium. This led us to the conclusion that the disturbances of vitamin-D-metabolism in pseudohypoparathyroidism type I is heterogenous.

Adolescent↗

[Pathogenesis of hyperthyroidism].

The present concept for the etiology of thyroid disease permits the definition of three separate entities occuring with hyperthyroidism: Graves' Disease, Toxic Nodular Goitre, Autonomous Adenoma. Physiopathological properties of these entities lead to a rational therapeutic strategy for each one of them.

Adenoma↗

[Evaluation of thyroid function in non-thyroid diseases].

The, in non-thyroidal illnesses, frequently occurring changes in the serum concentrations of peripheral thyroid hormones, are shown in patients with acute myocardial infarction, compensated and decompensated cirrhosis of the liver, renal insufficiency and in rheumatoid arthritis. The observed changes, (pathological) low total triiodothyronine, low or normal total thyroxine, and normal thyrotrophine), can make the diagnosis of hyperthyroidism impossible. Only in control measurements, after cessation of the simultaneous non-thyroidal illness, the peripheral thyroid hormone concentrations are found to be in the hyperthyroid range. The only way to establish the diagnosis, (or confirm the clinical suspicion), is to prove non-responsiveness of the pituitary to a TRH-stimulus. TRH-tests have, however, no diagnostic value in illnesses that affect pituitary function directly, such as terminal renal insufficiency. The diagnosis of hypothyroidism can be established by measurement of the basal thyrotrophine serum concentration (elevated) or by measurement of the serum concentrations of 3,3'5'-triiodothyronine (reverse T3), which is, according to a recent report, observed to be significantly decreased.

Arthritis, Rheumatoid↗

[Platelet retention and hypothyroidism: an investigation in patients with thyroid carcinoma treated by total thyroidectomy (author's transl)].

Platelet retention was investigated using a standardized technique with a glass pearl column in 18 patients with malignant thyroid disease treated by thyroidectomy before and after high-dose radioiodine treatment (80 or 150 mCi). As compared with the normal controls platelet retention was significantly lower in 13 hypothyroid patients in whom thyroidectomy had been undertaken at least 6 months previously and hormone substitution therapy had been interrupted 3 weeks before the period of investigation. The remaining 5 patients, studied about 18 days following thyroidectomy, were euthyroid and displayed platelet retention values within the lower limits of the normal range except for one patient with markedly reduced values. Thyroid substitution therapy with synthetic preparations induced recovery of platelet retention in both groups examined over a 4 week period, the increase being highly significant in the group of hypothyroid patients. A transient increase in platelet retention was observed 24 hours after a therapeutic dose of radioiodine, and initial values being regained after a further 24-hour period. This phenomenon was found in both, the euthyroid and hypothyroid group, however, it was more pronounced in the latter patients. Our results indicate a dependence of platelet retention on thyroid hormone concentration. The observed transient increase after radioiodine may be due to a radiation effect.

Adolescent↗

[Screening for hypothyroidism in the newborn with a total T 4-RIA method (author's transl)].

A screening method for detection of congenital hypothyroidism is presented in detail in cooperation with the "Austrian Program for Inborn Errors of Metabolism". Screening is performed by measuring the total T4-content of 1/8 inch filter paper dots filled with dried blood of newborns. The strategy for recall of newborns with borderline or pathological T4-values used, results in a definite diagnosis on day 55 of life. The advantages of additional TSH determination in the filter paper dots are discussed. So far (Sept. 1976) 8645 newborns have been investigated, covering the regions of Vienna and Carinthia (Austria). Preliminary studies reveal a slight dependency of the measured T4-values on the day of sampling. Two congenitally hypothyroid children have been diagnosed so far, corresponding fairly well with the reported frequency in the literature (1 : 6000).

Humans↗