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Biomedical subjects

J Fuchs

Publications and source records attributed to J Fuchs.

At least 235 records · Page 13Linked to original sources

On the interaction between anthralin and mitochondria: a revision.

Anthralin is an inhibitor of oxidative phosphorylation at concentrations found in vivo. ADP-stimulated oxygen consumption is diminished. Consequently, the rate of ATP synthesis is reduced and mitochondrial ATP content declines. Neither the isolated ATPase (F1F0-ATPase), nor the mitochondrial membrane-bound ATPase are influenced by the drug. Respiration under resting conditions is not affected. The experimental data unequivocally indicate that anthralin is not an uncoupler of oxidative phosphorylation, as previously stated. Furthermore, the interpretation that respiratory deficiency induced in yeast strains by anthralin is a consequence of petite mutations has to be reconsidered. Under in vivo conditions, anthralin inhibits respiration per se. Our experiments, including the electron spin resonance spectroscopy, reveal that anthralin alters mitochondrial membrane structure and function simultaneously. A redox or free-radical mediated step may be involved. In consequence, inhibition of ATP production occurs which may become the limiting factor for increased cellular metabolism in psoriasis.

Adenine Nucleotides↗

Circulating platelet aggregate size in ischemic heart disease.

Platelet aggregate size was measured in 178 patients with ischemic heart disease, among whom 56 had stable angina, 42 suffered from unstable angina, and 80 had had uncomplicated acute myocardial infarction. A group of 50 healthy volunteers and 20 hospitalized noncardiac patients served as controls. Venous blood (0.5 cc) was introduced into a solution containing 11.7 mM EDTA and 1.0 g formaldehyde. Platelet aggregate size was determined by microscopic reading as the number of platelets forming aggregates (per 1000 counted platelets) divided by the number of aggregates. Mean aggregate size was found not significantly different in both control groups, as well as in patients with stable angina and acute myocardial infarction (2.21 +/- 0.36 platelets, 2.20 +/- 0.58 platelets, 2.28 +/- 0.19 platelets, 2.76 +/- 1.07 platelets, respectively, p = NS). The highest value was found in the unstable angina group: 4.00 +/- 1.40 platelets (p less than 0.001 vs other studied groups). Platelet aggregate size was found not to be related to sex, age, medication, or coronary risk factors. Unstable angina may thus be a unique entity in ischemic heart disease concerning its platelet behavior, demonstrated in this study by the increased size of peripheral platelet aggregates, which may have pathogenetic, diagnostic, and eventual therapeutic implications.

Adult↗

Cushing's disease coexisting with a single macronodule simulating adenoma of the adrenal cortex.

A rare case of Cushing's disease coexisting with a single macronodule simulating adenoma of the adrenal cortex is presented. The basal and dynamic tests supported the diagnosis of Cushing's disease, whereas the CT-scan, ultrasound and iodocholesterol uptake were suggestive of a left adrenal adenoma. Treatment consisted of extirpation of the nodular gland followed by pituitary irradiation. The examination revealed a single macronodule with no histological membrane, surrounded by hyperplastic adrenocortex. Together with the three similar ones reported in the literature this case suggests that nodular hyperplasia may be an intermediary stage between diffuse hyperplasia and the appearance of an autonomous adenoma after long-term stimulation of the hyperplastic gland.

Adenoma↗

Effects of bepridil on heart mitochondrial membrane and the isolated rat heart preparation.

Bepridil (Cordium) was found to activate rat heart mitochondrial membrane-bound ATPase at concentrations of 10 nmol/l-10 mumol/l. By contrast, oligomycin-sensitive ATPase from beef heart mitochondria was inhibited at concentrations of 1-10 mumol/l. In both systems sensitivity toward the inhibitor oligomycin was reduced. Under the influence of the drug, RCR (coupling degree of electron transport to ATP synthesis), ST3 (oxygen uptake in presence of substrate and ADP) and OPR (oxidative phosphorylation rate, amount of ATP synthesized in mitochondrial metabolic state ST3) values are reduced, indicating partial inhibition of oxidative phosphorylation. At 0.25 mumol/l concentration of bepridil, in the isolated normoxic working rat heart preparation aortic flow was reduced to zero. No changes in oxidative phosphorylation parameters were found in mitochondria isolated from these preparations. In the isolated, working rat heart preparation bepridil at a concentration of 0.05 mumol/l reduced aortic flow to about 75% of its original value. In this preparation, no cardioprotective effects (neither on aortic flow nor on mitochondrial function) could be demonstrated during postischemic reperfusion. It is suggested, that in vitro mitochondrial activities of bepridil are not related to in vivo action of the drug.

Adenosine Triphosphatases↗

Lactate dehydrogenase isoenzymes in serum during unstable angina.

Values for total lactate dehydrogenase (LD, EC 1.1.1.27) activity in serum, LD isoenzymes 1 and 2, and the LD 1:2 ratio in 25 patients with unstable angina were compared with the same variables in 25 patients whose angina was stable 24, 48, and 72 h after admission. Mean total LD activity and mean LD-2 activity were found to be within the normal range, both in the unstable angina and stable angina groups of patients. In the unstable angina group the mean LD-1 was significantly higher (p less than 0.01) than in the stable angina group at each time studied. The mean LD 1:2 ratio was also significantly different (p less than 0.001) between the two groups of patients. In the unstable angina group of patients the ratio was increased (0.85, SD 0.09), as in patients with acute myocardial infarction, whereas in the stable angina group of patients the ratio was normal (0.60, SD 0.06). We conclude that a high LD 1:2 ratio, even in the presence of normal total LD activity, may indicate myocardial damage in some patients with unstable angina and could therefore help in the clinical and functional evaluation of patients with unstable angina.

Adult↗

Euthyroid atypical subacute thyroiditis simulating systemic or malignant disease.

An unusual form of atypical subacute thyroiditis (SAT) occurred in 13 patients. The clinical presentation in all patients simulated systemic or malignant disease, involving fever of long duration and loss of weight without localized thyroid tenderness and without signs or symptoms of thyrotoxicosis. Eleven of the 13 patients had normal serum free thyroxine values. In the ten patients in whom a needle biopsy was done, the histologic findings were the same as in typical SAT. In the other three patients, the diagnosis was made based on the following clinical findings: high erythrocyte sedimentation rate, low radioactive iodine uptake, and good response to salicylate (aspirin, 2 g/day) or steroid (prednisone, 30 mg/day) treatment. Early recognition of this variation of atypical SAT may save the patients unnecessary investigations in search of systemic or malignant disease.

Adult↗

Polymyositic heart disease.

There is an apparent correlation between the severity and duration of skeletal muscle involvement, cardiac manifestations and the extent of conduction system disease in polymyositis. Cardiac involvement during the course of polymyositis has been recognized as one of the typical features of skeletal muscle myositis. We report a patient with polymyositis in whom bifascicular block, prolonged P-R interval and congestive heart failure appeared three years before any clinical or laboratory evidence of active skeletal muscle myositis. To the best of our knowledge, this is the first report of polymyositis where cardiac manifestations preceded those of skeletal muscle myositis.

Cardiomyopathies↗

2-Mercaptopropionylglycine and related compounds in treatment of mitochondrial dysfunction and postischemic myocardial damage.

Reversal of mitochondrial dysfunction caused by uncouplers of oxidative phosphorylation, diamide, ageing and ischemia was studied using 2-mercaptopropionylglycine (MPG) in reduced and oxidized (ox-MPG) forms and other SH compounds. Rat heart mitochondria and mitochondrial ATPase, OS-ATPase from beef heart and the isolated working rat heart preparation were examined. MPG and ox-MPG partly prevented and reversed mitochondrial uncoupling and improved deteriorated heart function. ATPase activities were decreased by MPG and ox-MPG in both types of preparation. Three mechanisms are probably involved in thiol action. These comprise alternatively and/or additively: a) SH/S-S interchange reactions; b) free radical scavenger function; c) polar-polar (apolar) interactions. This may contribute to improve oxidative phosphorylation which is considered as a result of recoupling damaged mitochondria by MPG.

Adenosine Triphosphatases↗

Plasma viscosity in ischemic heart disease.

Plasma viscosity was measured by the capillary method in 108 patients with ischemic heart disease. The highest value of plasma viscosity was found in 11 patients with severe unstable angina (1.66 +/- 0.068), while in 18 patients with less severe unstable angina plasma viscosity was lower (1.61 +/- 0.056; p less than 0.025). In 43 patients with acute myocardial infarction plasma viscosity was 1.53 +/- 0.10, significantly lower than in the two groups with unstable angina (p less than 0.005). In 36 patients with stable angina plasma viscosity was 1.42 +/- 0.089, similar to that found in 100 normal subjects. Plasma viscosity did not increase in 30 ischemic heart disease patients during exercise-induced myocardial ischemia. It is suggested that the elevated plasma viscosity in unstable angina demonstrated in this study compromises the oxygen delivery to the myocardium and coronary blood flow and therefore may possibly be a factor in the pathophysiology of this syndrome.

Adult↗

Low serum creatine phosphokinase values in patients with acute viral hepatitis.

Low values of serum creatine phosphokinase (CPK) were found in a group of 27 patients suffering from acute viral hepatitis. The values were significantly lower than CPK values in a group of 25 patients with extra hepatic obstructive jaundice (23.3 +/- 32.1 versus 163 +/- 43 U/L, p less than 0.001). CPK values in the hepatitis group when recovered (6 months after hospitalization) were much higher than the mean CPK levels in the same group during the acute illness (178 +/- 28 versus 23.3 +/- 32.1 U/L, p less than 0.001) and were the same as a control group of 26 healthy volunteers (179 +/- 28 versus 179 +/- 20.9 U/L). Similar results were found when the groups were divided into separate male and female groups. Serum CPK values, thus, were found to be a useful diagnostic tool to distinguish between patients with intrahepatic jaundice due to acute viral hepatitis and patients with extra hepatic obstructive jaundice.

Adolescent↗

Multiform accelerated idioventricular rhythm in acute myocardial infarction: electrocardiographic characteristics and response to verapamil.

Thirteen patients with acute myocardial infarction with multiform accelerated idioventricular rhythm (AIVR) occurring during the first 12 hours of monitoring in the coronary care unit are described. This arrhythmia, similar to the more common uniform AIVR, was intermittent, did not cause hemodynamic compromise, and was not related to more serious ventricular arrhythmias. There was no correlation between the bundle branch block pattern of the multiform AIVR and the electrocardiographic location of the myocardial infarction, but there was a perfect correlation between the frontal plane electrical axis of the multiform AIVR and the electrocardiographic location of the myocardial infarction. The presence of fusion beats between the different forms of AIVR suggests multifocality rather than multiformity. Intravenous verapamil (3 to 5 mg bolus) was administered to 6 patients with multiform AIVR in whom the arrhythmias were persistent enough to allow the evaluation of the effect of verapamil on the arrhythmia. Verapamil caused no change in the rate of AIVR in 1 patient, but in a second patient it decreased the rate by 20 beats/min. In 4 patients, verapamil abolished the arrhythmia: in 2 patients carotid sinus pressure (induced sinus slowing) allowed the emergence of the AIVR at a lower rate, and in the remaining 2 patients the arrhythmia was not observed.

Adult↗

Entorhinal cortex lesions induce a decreased calcium transport in hippocampal mitochondria.

Lesions to the entorhinal afferent of the hippocampus in rats caused marked changes in calcium transport into mitochondria. Pyruvate-supported calcium transport into mitochondria from the denervated hippocampus was decreased to a larger extent than succinate-supported transport, and adenosine triphosphate-supported transport was not significantly modified. Although cytochrome oxidase and succinate dehydrogenase activities were not significantly changed by entorhinal lesions, pyruvate flux through pyruvate dehydrogenase was significantly decreased, and this effect was correlated with changes in pyruvate-supported calcium transport. The active portion of pyruvate dehydrogenase decreased, whereas total pyruvate dehydrogenase was not modified. These data suggest that denervation might initiate dendritic atrophy and subsequent growth responses by modifying calcium regulation through a change in the phosphorylation of pyruvate dehydrogenase.

Adenosine Triphosphate↗

[Diagnosis and therapy of carotid sinus syndrome (author's transl)].

We investigated 76 patients with carotid sinus syndrome followed over a time period of 12-40 months (mean 24 months). In 27 patients long-term ECG were recorded over 24 hours continuously. Carotid Doppler sonography was performed in all patients. 14 patients were studied electrophysiologically. The long-term ECG examinations in patients with carotid sinus syndrome showed a significant tendency to nocturnal bradycardia, and normal heart frequency during the day. In 41% of patients extracranial obstruction of internal carotid arteries could be demonstrated. During carotid sinus massage was a significant increase of the AH time, but there was no significant changes of the HV time. 12 out of 14 patients (86%) developed an AV-block during carotid sinus massage and atrial pacing. In 31 patients pacemakers were implanted. The indication for pacemaker implantation was the clinical symptom of syncope. These patients were observed over a period of 15-40 months (mean 24 months). 15 patients were free of symptoms after the pacemaker implantation, whereas 8 patients complained of dizziness and 4 patients experienced TIA's. 45 patients without pacemaker implantation were observed over a time period of 12-24 months. 30 patients were followed over 12 months. 16 patients were free of symptoms, 14 complained of dizziness. There was no syncopy in this group and no patients died during the observation period. In patients with cardio inhibitory carotid sinus syndrome and syncopy, pacemaker implantation is the therapy of choice. In asymptomatic patients or patients with occasional dizziness pacemaker is not indicated.

Aged↗