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Biomedical subjects

J Caron

Publications and source records attributed to J Caron.

176 records · Page 10Linked to original sources
PubMedDate not supplied

[Contribution of computed tomography to the diagnosis of benign tumors of the liver].

Computed tomography is a recently introduced, nonaggressive method of radiological investigation that can contribute to the study of hepatic tumors. Information obtained by using a third generation apparatus in six cases of benign hepatic tumor is reported, and compared with operative findings in five cases. The principal aspects, common to both ultrasonography and computed tomography examinations, are compared within the context of the pathological findings. Computed tomography is of value as a complementary investigation to reduce any possible insufficiency of ultrasonography examinations or to supply supplementary information during pre-operative tests.

Adult↗
PubMedDate not supplied

[Vascular effects of dihydropyridines].

Dihydropyridines are the most numerous available calcium antagonists. While belonging to the same group these drugs have physical, chemical, pharmacokinetic or pharmacodynamic properties which are sometimes specific and can explain differences in the targets and the vascular selectivity. These properties can be related to lipophilic or hydrophilic characteristics, existence or lack of 'use-dependence', possible liaison to membrane phospholipids, and differences in elimination half lives. Selectivity of dihydropyridines also depends on the nature of the target structure (amount of intra-cellular calcium storage and mechanism of its release, electrophysiological properties of these cells) and of its pathological state (atherosclerosis and/or hypertension). Some of these properties could explain the anti-atherogenic effects, myocardial impact, cerebral and renal vascular flow and action in some pathological situations (Raynaud's syndrome, chronic arteriopathy, migraine...). A better knowledge of these different properties could lead to a more accurate choice of the drugs and to a decrease in the incidence of their side effects.

Blood Vessels↗
PubMedDate not supplied

[Progressive muscular dystrophies and drug risks].

Many therapeutic agents are necessary during the evolution of progressive muscular dystrophy to cure intercurrent diseases. Some of them may impair muscular structure and induce rhabdomyolysis, toxic or inflammatory myopathy. Other treatments may produce metabolic and functional alterations or impair cardiac and respiratory functions, yet endanged in progressive muscular dystrophy. They must be contra-indicated or used carefully during progressive muscular dystrophy.

Humans↗
PubMedDate not supplied

[Methods of antiarrhythmic drug evaluation in man].

Antiarrhythmic drugs (AA) are useful in some critical situations but their use remains questionable. Evaluation of their efficacy and possible side effects required accurate knowledge of various methods. ECG gives relevant informations on the conduction intervals alterations caused by AA. Holter monitoring allows evaluation of the efficacy and/or proarrhythmic effects throughout 24-48 hour periods provided that spontaneous variability is taken into account. Ambulatory sequential loop ECG allows a longer monitoring of treatment in patients with symptomatic arrhythmias. Provocative electrophysiological testings give good evaluation of AA efficacy in some supraventricular or ventricular arrhythymias but predictivity of efficacy or proarrhythmic effects is sometimes problematical. Use of effort testing is limited to evaluation of antiarrhythmic effects of drugs in major dysrythmias and in some frequency-dependent dysrythmias, but this technique allows also detection of proarrhythmic incidence in those extremely altered autonomic nervous system tone. Other techniques of evaluation (Signal averaged ECG, automatic implantable cardiovecter defibrillator with holter monitoring, drug plasma concentration monitoring) are still under discussion.

Anti-Arrhythmia Agents↗
PubMedDate not supplied

[Antagonists of calcium movements and rhythm disorders].

Since transmembrane myocardiac calcium-exchanges play an important role in myocyte electrogenesis as well as in triggering and maintenance of some cardiac arrhythmias, it might be true that calcium antagonists possess antiarrhythmic properties. However, use of calcium antagonists as antiarrhythmic agents is only possible if the drug is devoid of sympathetic reflex stimulation and possesses use-dependence properties. These drugs are of most efficiency in cardiac arrhythmias (especially of supraventricular origin), caused by reentry phenomena in which part of the circuit is governed by calcicosodic cells. The use of calcium antagonists for ventricular arrhythmias is limited to some specific indications (idiopathic ventricular tachycardia with right bundle branch block and left axis, reperfusion arrhythmias...). Choice of the type and the route of administration of calcium antagonists has to take into account their pharmacokinetic specificities which can alter their antiarrhythmic potency.

Arrhythmias, Cardiac↗