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Biomedical subjects

M Stäubli

Publications and source records attributed to M Stäubli.

At least 19 recordsLinked to original sources
PubMed1990

[Acute hepatitis following administration of fansidar].

Since 1971 pyrimethamine-sulfadoxine (Fansidar, Roche) has been used worldwide for prophylaxis and therapy of chloroquine resistant Plasmodium falciparum malaria. The drug monitoring team of the producing firm has received reports of a number of cutaneous adverse reactions, some severe, and a few even with fatal outcome. Liver reactions were also encountered, with severe cases only in the recent literature. We report on two patients with hepatitis in temporal relationship to pyrimethamine-sulfadoxine, the first with a second event after later exposure to the same drug. After discontinuing the medication the liver function abnormalities returned to normal limits within a few weeks. Liver biopsy and a positive lymphocyte transformation test against sulfadoxine, a component of Fansidar, strongly suggest that Fansidar was the cause of hepatic injury.

Adult↗
PubMed1990

Myocardial infarction during a football game: empiric estimation of the contribution of skeletal muscle damage to the serum creatine kinase activity.

A 40-year-old untrained participant of a competitive football game experienced chest pain after 20 minutes of playing time. An acute anterior myocardial infarction was diagnosed by electrocardiographic criteria and the creatine kinase rose to its maximum of 3900 U/l (normal range less than 125 U/l) by 24 h with a CK-MB fraction of 6.1%. In order to estimate the contribution of skeletal muscular work to CK activity, the course of CK activity was prospectively measured in 11 untrained participants of a competitive football game, who had normal electrocardiographic findings on exercise testing. Individual peak values of CK correlated positively (p less than 0.01) with the time spent in play. Based on this observation we could estimate that, at most, 14% of the total CK was contributed by skeletal muscle damage in our patient. When total CK was elevated above 125 U/l, the percentage of CK-MB activity did not exceed 6% of total CK in any case. 3-methylhistidine, methylhistidine, an indicator of contractile protein turnover and creatinine were prospectively determined in spot urine samples before the game and for up to 48 h after the game. 3-methylhistidine/creatinine ratios did not change from baseline after the game and no correlation with CK was found. Urine 3-methylhistidine/creatinine, measured within 48 h after a football game, does not contribute to the quantification of skeletal muscle damage.

Adult↗
PubMed1989

[Giant adenoma of Brunner's glands].

Bleeding, obstruction and invagination are the common symptoms of large polyps in the duodenal bulb. We present 2 patients with a large ulcerated Brunner's gland adenoma. The clinical findings were acute bleeding and nonspecific upper gastrointestinal symptoms. The treatment was surgical due to a suspect histological finding in one case, a thick stalk in the other, and the fact that endoscopic polypectomy is a much higher risk procedure in the duodenum than in the colon.

Adenoma↗
PubMed1988

[Amiodarone].

The extraordinary antiarrhythmic efficacy of amiodarone has been well documented in the last few years. Parallel investigations of the electrophysiologic influence of this iodinated benzofuran derivative on myocardial tissue showed that repolarizing as well as depolarizing currents are inhibited. However, the detailed electrochemical aspects of these effects are only partly understood. Likewise, ideas on causes of the differences in hemodynamic and electrophysiologic actions of oral and intravenous amiodarone are still speculative. An understanding of the actions of amiodarone is particularly difficult to achieve because of the unique pharmacokinetics of the drug: it resides in extra-plasmatic compartments for months after discontinuation of treatment, a fact which explains, for example, the lack of an established dose/response relationship. Replacement of amiodarone by another antiarrhythmic drug in the same patient may be problematic, because pharmacokinetic and pharmacodynamic interactions of residual amiodarone with the new antiarrhythmic drug are to be expected. Therefore, amiodarone should be prescribed only in cases where other treatment has failed. This is also advisable in view of the long list of amiodarone-induced adverse reactions. Determinations of plasma concentrations of amiodarone and desethylamiodarone may be useful in some instances, but must never replace clinical evaluation of antiarrhythmic drug efficacy. Although the incidence of some amiodarone-induced adverse reactions increases with dosage and serum drug level, dose-independent factors may play a role in the rare but serious pulmonary and hepatic side effects.

Amiodarone↗
PubMed1988

[Severe complications during enalapril therapy for heart insufficiency].

In 3 patients with severe cardiac failure high dose therapy with the ACE inhibitor enalapril was instituted during a state of extracellular volume depletion. Severe arterial hypotension with reversible renal insufficiency developed in all the patients. In two the hypovolemia was induced by diuretic treatment and in one by an acute infection with diarrhea. The latter patient also developed life-threatening hyperkalemia with cardiac arrest since he was also receiving spironolactone and potassium supplements. These cases demonstrate that ACE inhibitors should not be instituted during extracellular volume depletion and their initial dosage should be low. The dangerous combination of ACE inhibitors with spironolactone and potassium supplements should be avoided wherever possible.

Acute Kidney Injury↗
PubMed1988

Mechanisms of the haematological changes induced by hyperventilation.

During voluntary hyperventilation an increase in the lymphocyte and thrombocyte counts occurs, paralleled by an increase in plasma epinephrine and norepinephrine. All these changes are rapidly reversible after hyperventilation and are followed by an increase in the neutrophil granulocyte count. The pathophysiological mechanisms of these changes were investigated by comparison of the hyperventilation-induced changes of the blood picture in 11 normal, 9 splenectomized and 12 beta-blocked volunteers. Splenectomy did not affect the hyperventilation-induced mobilization of lymphocytes and neutrophils but totally suppressed the change in the thrombocyte count. beta-blockade by 80 mg propranolol did not suppress the hyperventilation-induced increase in neutrophils. It reduced the absolute increase of lymphocytes and thrombocytes by half, but it also increased the baseline counts of these cells. The study shows that hyperventilation mobilizes thrombocytes from the spleen but not from extralienal pools, and that lymphocytes and neutrophils are mobilized from extralienal pools. Whereas neutrophil mobilization is not suppressed by beta-blockade, the reduction of hyperventilation-induced mobilization of lymphocytes and thrombocytes may be due to a reduction in the size of the mobilizable cell pools, and therefore cannot be interpreted as a sure indication that adrenergic mechanisms are involved in their hyperventilation-induced mobilization.

Adult↗
PubMed1988

Anti-amiodarone antibodies: detection and relationship to the development of side effects.

PURPOSE: It has become evident in the past few years that amiodarone, a powerful antiarrhythmic agent, induces considerable side effects. These may be due to an amiodarone-elicited lipid storage disease and to the iodine content of amiodarone, but might also be causally related to amiodarone-induced immune reactions. The latter possibility prompted us to develop a sensitive anti-amiodarone antibody detection assay based on the immunodot technique. PATIENTS AND METHODS: Sera were obtained from 10 untreated control subjects and 33 patients receiving amiodarone. Using serum dilutions of 1:500 and 1:1,000, the lower detection limit was 0.3 microgram/ml of anti-amiodarone antibodies as calculated from a simultaneously performed IgG standard curve. RESULTS: Screening of sera from the untreated control subjects and amiodarone-treated patients revealed that the untreated subjects had no anti-amiodarone antibodies, that only one of 16 patients without clinical side effects had elevated anti-amiodarone antibodies, but that seven of 12 patients with amiodarone-induced thyroid disease and four of five patients with other side effects had elevated anti-amiodarone antibody titers (1.2 to 2.5 micrograms/ml). The combined evaluation of anti-amiodarone antibody titers and cumulative dose was found to be a highly reliable indicator of side effects, as all patients with more than 100-g cumulative dose of amiodarone and more than 0.6 microgram/ml of anti-amiodarone antibodies had side effects. CONCLUSION: The detection of anti-amiodarone antibodies in patients with amiodarone-elicited side effects underscores the possible contribution of immunologic reactions to the development of certain side effects.

Adult↗
PubMed1988

Low plasma concentrations of ionized calcium in patients with asthma.

It has been suggested that calcium homeostasis is abnormal in the vascular smooth muscle of hypertensive patients and in the bronchial smooth muscle in asthmatics. We have found the mean baseline concentration of plasma ionized calcium to be significantly lower both in 12 asthmatics with exercise-induced asthma (EIA) [1.16 +/- 0.01 (SE) mmol/l, P less than 0.001] and in 20 asthmatics without EIA (1.16 +/- 0.01; P less than 0.001) compared with 42 healthy subjects (1.24 +/- 0.01). The mean concentrations of plasma ionized calcium were not significantly different in asthmatics with and without EIA when measured either before treadmill exercise, during the last seconds of this exercise, or 10 or 20 min after exercise but were significantly lower than in another seven healthy subjects who undertook the same exercise protocol. Total plasma calcium concentrations in the three exercising groups were not significantly different at any point in time. The results suggest that in bronchial asthma an alteration of calcium metabolism may be important, but they also suggest that there is no simple relationship between the plasma ionized calcium concentration and acute exercise-induced bronchoconstriction.

Asthma↗
PubMed1987

[Hypokalemia in acute heart infarct].

Serum potassium in 20 patients with acute myocardial infarction (AMI) measured 2 to 6 hours after the beginning of chest pain was 3.8 +/- 0.4 mmol/l. This was lower than the value of 4.1 +/- 0.2 mmol/l of 29 controls admitted for elective evaluation of coronary heart disease. In patients with AMI there was a negative linear correlation between serum potassium and lymphocyte count. The hypothesis that AMI induces a decrease in potassium concentration by accompanying epinephrine secretion is supported by this correlation. In addition, respiratory alkalosis may play a role because it also induces hypokalemia and lymphocytosis. In view of the arrhythmogenic effect of hypokalemia, measures which reduce the epinephrine increase and hyperventilation, such as analgesic therapy and sedation, should be of potential antiarrhythmic value.

Aged↗
PubMed1987

Fluid trapping of erythrocytes under hypoosmolar conditions.

125I albumin was used to assess the amount of trapped fluid after microhematocrit centrifugation of erythrocytes suspended in buffers of different osmolality. Surprisingly the total amount of trapped fluid per volume unit of packed erythrocytes decreased with decreasing osmolality of the suspending buffer despite erythrocyte swelling. However, if the contribution of the individual erythrocyte to the trapped fluid was calculated, the trapped fluid per erythrocyte did not change between 311 mosm/kg and 256 mosm/kg. For osmolalities below 256 mosm/kg a significant increase of trapped fluid was obtained. It is concluded that the packing ability of erythrocytes is not impaired in suspending fluid of moderate to severe infraphysiological tonicity. The daily clinical experience that considerable degrees of plasma hypoosmolality are tolerated in vivo without hemolysis or impairment of oxygen transport by erythrocytes may be explained by the excellent ability of shape adaptation of erythrocytes to each other and to other surfaces such as vascular endothelia. The method of trapped fluid determination might be of potential value as a complementary method in the evaluation of erythrocyte rheology if the amount of trapped fluid is related to the individual erythrocyte.

Adult↗
PubMed1987

Interactions of amiodarone with digoxin in rats.

1. The influence of oral amiodarone treatment on the blood and tissue concentrations of digoxin was investigated in the anaesthetized rat by use of unlabelled and [3H]-digoxin. 2. Amiodarone diminished the total body clearance and the apparent volume of digoxin distribution by 60%. This reduction was due to a 50% reduction of the hepatobiliary clearance, whereas the renal clearance did not change. 3. Amiodarone treatment increased blood, myocardial and skeletal muscle [3H]-digoxin concentrations by 200% indicating passive equilibration between blood and these tissues, and resulting in unaltered tissue to blood ratios. In contrast, the liver concentration increased by 70% only and the liver to blood ratio therefore decreased under amiodarone treatment. 4. It is concluded that the hepatobiliary elimination of digoxin is decreased in amiodarone-treated rats compared to controls and is responsible for the increased levels of blood and tissue glycoside.

Amiodarone↗
PubMed1986

The mean red cell volume in long distance runners.

Red cell indices were determined in 6 well trained runners before and after a 100 km race, and Coulter Counter (CC) determinations compared with calculated values derived from centrifuged hematocrit (ctrf), red cell count (CC) and hemoglobin measurements. The following changes were observed immediately after the race, as compared to values 3 days before: MCV(ctrf) decreased by 4.9% (p less than 0.001), MCV(CC) increased by 1.9% (p less than 0.05), MCHC(ctrf) increased by 4% and MCHC(CC) decreased by 3%. The increase in MCV(CC) suggests that intraerythrocyte osmolality was increased, this probably leading to swelling of the cells induced by a shift of water from the diluting Coulter Counter solution into the red cells prior to the MCV measurement. The decrease in MCV(ctrf) immediately after the race was not correlated with the increase in plasma osmolality. This suggests that plasma osmolality alone was not the key factor for regulation of red cell volume. The changes in MCV(ctrf), which contributed to a surprising stability of the hematocrit value and plasma volume, might represent a physiological principle for the maintenance of a favourable blood viscosity.

Adult↗
PubMed1986

The effects of amiodarone on the electrocardiogram of the guinea-pig are not explained by interaction with thyroid hormone metabolism alone.

The iodine-containing contrast medium iopanoic acid induces alterations of thyroid hormone metabolism comparable to those observed with the iodine-containing antiarrhythmic drug amiodarone. Both compounds inhibit the intracellular conversion of thyroxine (T4) to triiodothyronine (T3). Using iopanoic acid, the question was investigated, in guinea-pigs, whether inhibition of T4----T3 conversion is by itself associated with the same changes in the electrocardiogram, i.e. QT prolongation and bradycardia, as those observed during amiodarone treatment. At a dose of 4 g kg-1, iopanoic acid induced maximal inhibition of the T4----T3 conversion. Although these changes were even more pronounced than those in a control group of animals treated with 2.12 g amiodarone kg-1, neither prolongation of the QT nor a slowing of the heart rate was observed. QT prolongation and bradycardia were induced only by amiodarone treatment but not by iopanoic acid. Iopanoic acid at the high toxic dose of 12 g kg-1 induced the same degree of inhibition of T4----T3 conversion as the 4 g kg-1 dose. QT prolongation and slowing of the heart rate were apparent at this dose in parallel with a loss of weight. It is concluded that even a maximal inhibition of the T4----T3 conversion has no effect on the ECG of guinea-pigs. The inhibition of the T4----T3 conversion alone does not explain the QT prolongation and bradycardia observed with amiodarone treatment. The amiodarone effects on the ECG may represent a combination of interactions with thyroid hormones and antiadrenergic activity.

Amiodarone↗
PubMed1986

Plasma volume and proteins in voluntary hyperventilation.

In a controlled study the changes of the plasma volume and plasma proteins induced by voluntary hyperventilation (HV) were investigated in nine splenectomized volunteers. The plasma volume changes were calculated from the changes of the hemoglobin and hematocrit. After 20 min of HV in supine position, which lead to a decrease of the venous CO2 partial pressure by 19 Torr and to an increase of plasma epinephrine and norepinephrine levels, the plasma volume was reduced by 12.9%. The intravascular masses of total protein, albumin, and several other proteins decreased during HV but a similar decrease of these proteins was also observed during the control study (C), i.e., rest in supine position without HV. The differences between changes during HV and C were not significant, indicating that the loss of protein was not due to HV. It is concluded that acute HV leads to a rapidly reversible loss of a virtually protein-free solution from the vascular space. The red cell compartment participated in fluid shifts in that the mean red cell volume decreased by 2.2% (P less than 0.02 compared with C). Comparison with earlier work shows that addition of erythrocytes from the normal spleen does not play a part in the HV-induced increase of hemoglobin and hematocrit.

Adolescent↗
PubMed1985

Amiodarone-treated patients with suppressed TSH test are at risk of thyrotoxicosis.

Therapeutic use of the potent antiarrhythmic drug amiodarone requires early detection of impending hyperthyroidism, a potentially life-threatening adverse reaction in cardiac patients. Since amiodarone inhibits peripheral conversion of thyroxine (T4) to triiodothyronine (T3), serum T4 and T3 levels become unreliable parameters of thyroid function. In 44 patients treated with amiodarone for a median period of 7.3 months, up to seven TRH-TSH tests were performed. The TSH response to TRH was normal in 23 patients, partially suppressed in eight, totally suppressed in eight and overshooting in five patients. Two of the eight patients with suppressed TRH-TSH tests were clinically hyperthyroid, in four others thyrotoxicosis developed within 1 to 2 1/2 months after the first observation of a suppressed TSH response, while two patients remained euthyroid. In all patients with negative TRH-TSH tests. TSH response to TRH returned to normal between 2 and 29 months after withdrawal of amiodarone. We conclude that the TRH-TSH test, repeated at intervals, is a reliable tool for assessing thyroid function in patients on long-term treatment with amiodarone. Patients with a suppressed response under amiodarone therapy are at risk of developing thyrotoxicosis. Normalization of the TSH response indicates that this risk is over.

Adolescent↗