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Biomedical subjects

M Weissel

Publications and source records attributed to M Weissel.

At least 55 records · Page 3Linked to original sources
PubMed1991

Clinical evaluation of new assays for determination of serum calcitonin concentrations.

In order to test the clinical usefulness of new commercially available kits for determination of calcitonin serum concentrations, we investigated the family (N = 10) of a patient with medullary thyroid carcinoma and bilateral pheochromocytoma including his affected son, 10 athyreotic patients, totally thyroidectomized for non-medullary thyroid cancer, and 4 normal volunteers. Pentagastrin tests were performed in all subjects. Serum calcitonin levels before and after pentagastrin were determined by 4 kits. Kits A and B are immunoradiometric assays of the sandwich-type, kits C and D are radioimmunoassays, D being the one hitherto routinely used. Our results show that the new assays (kits A, B and C) have a better diagnostic accuracy in screening for medullary thyroid cancer than the RIA (kit D), hitherto used, where basal values overlapped with normals. Although basal values of normals were mostly near the detection limit of all 4 kits, kits A and B were sensitive enough to detect stimulation of calcitonin secretion by pentagastrin in all subjects with intact thyroid glands and kit C in most of them. The lack of increase in calcitonin after pentagastrin observed by kits A, B and C in athyreotic patients suggests deficiency of secretion of this hormone. Only kit D was unable to show this deficiency.

Adrenal Gland Neoplasms↗
PubMed1991

[Iodine containing drugs and thyroid gland function. A diagnostic and therapeutic problem].

Iodine-induced thyroid dysfunction will become more important in Austria in the near future, because of the augmentation of the iodine content in salt in 1990. This review therefore tries to summarize the diagnostic and therapeutic problems that may arise in iodine-induced thyroid disease. After discussion of the physiologic reaction of the normal thyroid to iodine the most frequently used iodine-containing drugs used in Austria are presented. Special emphasis is laid on iodine containing antiseptics and on the antiarrhythmic drug amiodarone. The influence of iodine supplementation on the reaction of diseased thyroid glands to iodine overload is stressed. The diagnosis of iodine induced thyroid dysfunction is relatively simple, once it is thought of. Amiodarone-iodine induced thyroid disease may be an exception, because of the intrinsic effect of this drug on thyroid hormone metabolism. Since high intra-thyroidal iodine content inhibits the action of thyrostatics, therapy of iodine-induced hyperthyroidism may be complicated. Alternative possibilities such as cortisone, perchlorate or surgery in thyroid storm are presented. Substitution with 1-thyroxine in iodine-induced hypothyroidism may be harmful in elderly patients with cardiac problems. In conclusion, this review tries to present the state of the art of the solution of diagnostic and therapeutic problems in thyroid dysfunction due to iodine administration.

Amiodarone↗
PubMed1990

Felodipine is more effective than hydrochlorothiazide when added to a beta-blocker in treating elderly hypertensive patients.

This randomized, double-blind, parallel-group study compared felodipine and hydrochlorothiazide (HCT) given in addition to a beta-blocker in 134 elderly hypertensive patients aged 56-79 years (mean of 66 +/- 5 years). In the felodipine-treated group (n = 57), supine blood pressure (BP) was reduced from 171 +/- 16/101 +/- 6 mm Hg at randomization to 147 +/- 12/86 +/- 6 mm Hg after 8 weeks, whereas in the HCT-treated group (n = 66), BP was reduced from 170 +/- 4/101 +/- 5 to 151 +/- 16/89 +/- 9 mm Hg. The reduction in diastolic blood pressure (DBP) was significantly greater in the felodipine than in the HCT group (p less than 0.003). In the felodipine-treated group, 87% of the patients were controlled (DBP less than or equal to 90 mm Hg) compared with 58% in the HCT group (p less than 0.001). Reported adverse events were generally mild. Six patients withdrew from the study due to adverse events, five in the felodipine group and one in the HCT group.

Adrenergic beta-Antagonists↗
PubMed1990

[Can the thyrotropin (TSH) suppressive dose of L-thyroxine (T4) be individually predicted in athyroid patients?].

TSH-suppressive doses of L-thyroxine (T4) are needed in the treatment of athyreotic cancer patients in order to prevent metastases. We were interested to know whether the TSH-suppressive dose can be predicted on a body weight-or body surface basis in athyreotic individuals, which might save them the control TRH-test. 92 athyreotic patients (22 men, 70 females; age 25-81, mean 50.4 yrs; body weight ranging from 48-114 kg, mean 73), who have been operated for differentiated thyroid cancer and who have had at least one treatment ablative doses of 131-I, were investigated. After 4 weeks without thyroid hormone supplementation (checked by TSH serum concentration above 20 microU/ml) patients were set on 150 mcg of L-T4/day. TSH serum concentration before and 20' after 200 mcg of TRH were measured by the ultrasensitive TSH kit of Behringwerke. Total and free T4 as well as total T3 were also measured by radioimmunoassay kits. TRH tests were performed 6 weeks after start of treatment in 51 patients and 8 or more weeks respectively in 41 patients. Only the inclusion of the influence of age (multiple correlation) yielded a significant positive correlation between basal TSH and L-T4 dose/body weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Interpretation of plasma concentrations of human atrial natriuretic peptide (hANP) in congestive heart failure.

The present study reports about novel findings concerning the interrelationship between release of human atrial natriuretic factor (hANP) and the clinical situation of patients suffering from congestive heart failure. Estimations of plasma hANP were done by specific and sensitive extraction-based RIA. The normal range was 5 to 80 ng/l, mean +/- SEM = 30 +/- 15 ng/l, n = 106. Influence of response to therapy on hANP-release was studied in altogether 14 patients. 12 of these patients had elevated plasma hANP at admittance, surprisingly peptide levels were normal in 2 patients throughout the study. 9 out of the 14 patients responded well to therapy (shift from NYHA IV/III to NYHA II within about 10 days), hANP-levels decreased to normal values: 235 +/- 104 ng/l vs. 65 +/- 13 ng/l; p less than 0.001. The 5 residual patients responded to therapy only partially (shift from HYHA IV to NYHA III within an observation interval of about 2 weeks). Plasma hANP values decreased from 225 +/- 94 ng/l to 137 +/- 22 ng/l (p less than 0.02), but were still supranormal. Atrial fibrillation, which persisted in 8 out of the 14 patients after therapy did not influence hANP levels: hANP levels paralleled clinical signs of improvement, irrespective of atrial fibrillation. Right heart catheterization revealed very high mean right atrial pressures in those 2 patients mentioned above, who had normal pretherapeutic hANP.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Fibrillation↗
PubMed1989

Prostacyclin I2 (PGI2) increases left ventricular ejection fraction (LVEF).

In order to evaluate the effect of PGI2 on left ventricular ejection fraction (LVEF) an intravenous infusion in 10 patients (3 males, 7 females; 36 to 63 years) with an impaired LVEF (34.7 +/- 14.8%) was performed. LVEF was determined by means of 99mTc-pertechnetate radionuclide ventriculography. An increase of LVEF to 36.2 +/- 13.5% during administration of PGI2 at a rate of 1 ng/kg/min for 15 min and to 43.8 +/- 15.8% during a rate of 5 ng/kg/min (p less than 0.01) for an additional 15 min was observed. Analyzing the data in more detail in 6 patients, an improvement in LVEF became obvious during the administration of 1 ng/kg/min (108, 109, 116, 118, 121, and 123% of pre-infusion value, respectively). In 5 out of these 6 patients a dose-increment to 5 ng/kg/min further increased LVEF (139, 179, 187, 148, and 128% of pre-infusion value, respectively). In contrast, in the other 4 patients no response of LVEF to PGI2 at a rate of 1 ng/kg/min could be observed. However, in 2 out of these 4 patients LVEF increased during the administration of 5 ng/kg/min (111 and 117% of pre-infusion value). Individual changes in hemodynamic parameters showed no correlation to the improvement seen in LVEF in response to PGI2. It is concluded that PGI2 may exert beneficial effects on LVEF, and might be used in certain clinical conditions, such as before heart transplantation, to achieve a temporary improvement in LVEF.

Adult↗
PubMed1989

[Hypertriglyceridemia: an independent risk factor for cardiovascular diseases?].

This review deals with the question whether hypertriglyceridemia represents an independent risk factor for the development of cardiovascular disease. The accepted definition of hyper- and "borderline"-hypertriglyceridemia is presented as well as its most frequent causes. After discussion of the hypotheses of the possible ways of mechanisms by which elevated serum triglycerides may be atherogenic the available epidemiologic data are analysed: summarizing these results it can be stated that in contrast to previous statements hypertriglyceridemia seems to be an independent risk factor for the development of cardiovascular disease, even after correction for other risk factors like total cholesterol, smoking, familial history, age or similar well known factors. Even the Framingham study that in earlier studies denied an independent role of the serum triglycerides showed recently that serum triglycerides correlated significantly with coronary heart disease after correction of other risk factors, especially in women. In conclusion, the recommendations of the European and American Consensus Conferences for patients with hypertriglyceridemia are presented: these conferences agree that even borderline hypertriglyceridemia should be investigated for its cause and treated by diet and if this fails by drugs.

Coronary Disease↗
PubMed1988

HLA-DR and differentiated thyroid cancer. Lack of association with the nonmedullary types and possible association with the medullary type.

One hundred twenty-seven white European patients with differentiated thyroid cancer were typed for human lymphocyte antigen (HLA) DR specificities. There was no significant deviation from the HLA-DR distribution observed in 160 normal patient controls, neither in the entire group nor in the patient groups with nonmedullary types of thyroid cancer (61 with papillary and 44 with follicular, all nonradiation associated). Also, subdivision of patients with nonmedullary thyroid cancer according to age at diagnosis, presence of metastases, and presence of thyroglobulin antibodies in serum showed no significant deviation from the HLA-DR distribution. For the patients with medullary thyroid cancer (only sporadic [n = 20] or inherited isolated [n = 2] forms, no multiple endocrine neoplasias), there was a significant increase of HLA-DR2 (11 of 22 cases [50%]) in comparison with control patients (22%; P corrected to 0.02; relative risk, 3.6). These data suggest, in contrast to previous reports, that there is no genetic influence on the development of nonmedullary types of differentiated thyroid cancer. Medullary thyroid cancer without multiple endocrine neoplasia, however, may be associated with HLA-DR2.

Carcinoma↗
PubMed1988

[Effect of PGE1 on the left ventricular ejection fraction].

12 patients with impaired left ventricular function were submitted to left ventricular ejection fraction measurements before and after increasing doses of PGE1 administered by i.v. or i.a. infusion. 6 responders out of the 12 patients showed a significant (p less than 0.01) improvement in LVEF, whereas the LVEF remained unchanged in the remaining 6 patients. 4 of the responders had received intravenous and 2 had received intraarterial PGE 1. Afterload reduction, venous tonisation, increased myocardial contractility and metabolic effects may be causative factors. These results suggest that PGE 1 therapy may be of therapeutic benefit in some patients with impaired LVEF.

Adult↗
PubMed1988

Influence of L-thyroxine on cardiac function in athyreotic thyroid cancer patients--an echophonocardiographic study.

We have assessed left ventricular performance in twelve athyreotic patients by echophonocardiography during and after their follow-up investigations. Patients were investigated after 4 weeks without and after 2 as well as 4 weeks of therapy with 150-200 micrograms L-thyroxine (L-T4). At the end of 4 weeks withdrawal of L-T4 patients were severely hypothyroid in terms of T4 and thyrotropin (TSH) serum levels as well as total cholesterol plasma levels. In comparison to values obtained in 12 age and sex matched normal controls left ventricular preejection period was prolonged at that time point (110 +/- 20 vs. 90 +/- 20 (SD) ms, p less than 0.05) and the isovolumetric relaxation period (IVRP) was significantly lengthened (78 +/- 16 vs 54 +/- 10 ms, p less than 0.01). Left ventricular ejection phase indices (fractional shortening and mean velocity of circumferential fiber shortening) did not differ significantly from normal. Preejection period dropped to 90 +/- 20 ms (p less than 0.05) after 4 weeks of therapy with L-T4. IVRP decreased to 67 +/- 13 ms (p less than 0.01) but remained significantly prolonged compared to normal. Serum T4, TSH and plasma cholesterol were compatible with borderline hyperthyroidism at that thime point. Thus, systolic as well as diastolic left ventricular performance (especially during isovolumic phases) appear to respond rapidly to thyroid hormone deficiency of short duration and at least partly to resupplementation.

Adenocarcinoma↗
PubMed1988

Suppression of thyroglobulin secretion in amiodarone iodine-induced thyrotoxicosis.

A 41-year-old male patient developed amiodarone-induced thyrotoxicosis after 29 months of treatment with amiodarone. Thyrotoxicosis was readily reversible after cessation of the drug and did not need specific thyrostatic treatment. In contrast to what was expected, thyroglobulin serum concentrations, that were normal during the first 2 yr of follow up, decreased drastically to undetectable levels during and after the thyrotoxic phase. Although no explanation can be offered for this phenomenon, it seems important to point out the fact that measurement of thyroglobulin is of only limited value in the diagnosis of thyroid dysfunction in patients treated with amiodarone. Low levels do not exclude thyrotoxicosis.

Adult↗
PubMed1988

Recurrent paradoxical embolism complicating severe thromboembolic pulmonary hypertension.

A patient with a three-year history of recurrent pulmonary embolism is presented. Thromboembolic pulmonary hypertension was proven in the final stage of disease in the presence of repeated episodes of systemic embolic events. Paradoxical embolism was assumed to be present on the basis of blood-gas analysis and contrast echocardiography that demonstrated a right-to-left shunt at atrial level. Autopsy revealed a patent foramen ovale and provided strong evidence for the accuracy of the clinical diagnosis.

Adult↗
PubMed1988

Human atrial natriuretic peptide secretion in precapillary pulmonary hypertension. Clinical study in patients with COPD and interstitial fibrosis.

Human atrial natriuretic peptide (hANP) is stored by granules of both human atria. Atrial distension appears to be a major stimulus for hANP secretion. Precapillary pulmonary hypertension increases right ventricular afterload and may thus cause right atrial distension. We therefore hypothesized that hANP plasma concentrations (1) are higher in the right atrium than in the peripheral vein, (2) are increased in patients with precapillary pulmonary hypertension, and (3) correlate with right atrial pressure. Thirty-three adult patients with chronic obstructive pulmonary disease (COPD) or interstitial fibrosis were examined by right heart catheterization. Mean pressures were measured in the right atrium, pulmonary artery, and pulmonary capillary wedge position, and blood was drawn from the right atrium and from a peripheral vein for determination of hANP levels. In general, hANP plasma levels in the right atrium were significantly higher than in a peripheral vein. Seventeen out of 33 patients had pulmonary hypertension, whereas 16 patients exhibited normal pulmonary artery mean pressures. In all patients, pulmonary arterial wedge pressure was normal. Plasma hANP concentrations were significantly higher in patients with pulmonary hypertension than in patients with normal pulmonary artery pressure. A strong correlation between central or peripheral hANP plasma levels (or both) and mean right atrial pressure could be observed (r = 0.75; p less than 0.001). From these data, we conclude that the increased secretion of hANP in our patients with precapillary pulmonary hypertension appears to be mediated by right atrial distension.

Adult↗