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J Descotes

Publications and source records attributed to J Descotes.

At least 145 records · Page 8Linked to original sources
PubMed1980

Effects of mild hyperkalemia on conduction velocity and effective refractory period in various parts of the dog heart in situ.

Effects of mild hyperkalemia on conduction velocity, effective refractory periods (ERPs) and sinus rate were studied on 16 anesthetized dogs, using endocavitary His bundle recordings, the extrastimulus method and standard electrocardiogram. Six dogs were placed under acetylcholine infusion (300 micrograms/kg/min) (ACh group), 10 received atropine sulfate 0.2 mg/kg intravenously (atropine group). Intraventricular conduction time, ventricular ERP and QRS duration of the EKG were studied on 7 other open-chested dogs (ventricular group). During a 60 min potassium chloride infusion (0.025 mmol/kg/min, 30 min, then 0.05 mmol/kg/min, 30 min), following observations were made: - In the ACh group, AV node conduction time (A-H interval) decreased by 20% and AV node ERP by 17%, whereas, in the atropine group, the former parameter was not affected and atrial ERP increased by 29%. - At the same time, sinus rate increased in the ACh group and was unaffected in the atropine group. - Conduction times in atrial contractile tissue (S-A interval), His-Purkinje system (H-V interval) and ventricular contractile tissue, like ventricular ERP, exhibited no variation or very slight, occasionally biphasic variations under both conditions. These results can be accounted for by an "anticholinergic" effect of mild hyperkalemia which is discussed.

Animals↗
PubMed1980

Inhibition by idrocilamide of the disposition of caffeine.

The pharmacokinetics of caffeine are greatly altered by concomitant administration of idrocilamide. In four healthy volunteers id rocilamide inhibited the biotransformation of caffeine and increased its half-life nine times. The untoward neuropsychiatric effects of idrocilamide are the consequence of abnormal accumulation of caffeine in regular consumers of caffeine-containing foods and beverages.

Adult↗
PubMed1980

Macromolecular and histological studies of new tissue formation in velour vascular prostheses.

The nature and characteristics of the tissue which develops on the inner surfaces of vascular arterial prostheses have been investigated by means of histological and biochemical criteria. Velour prosthetic tubes were implanted as aortic segmental replacements in the dog. On the 60th postoperative day, a neointimal layer of collagen covered with flattened endothelial-like cells was noted. However, despite this morphological evidence the microsomic and cytosolic enzymes implicated in the biosynthesis of glycosamino-glycuronoglycans were significantly modified in comparison with the normal aortic wall. The marked decrease in enzymes corresponding to the initiation of the glucidic linkages suggests that the biosynthesis of the macromolecular components responsible for the normal blood vaessel interfact was impaired in these newly developed tissues. Therefore, it is suggested that this newly developed tissue cannot be considered as a true vascular endothelium.

Acetylglucosamine↗
PubMed1980

Another look at the Sparks-Mandril arterial graft precursor for vascular repair. - Pathology by scanning electron microscopy.

The Sparks-Mandril blood vessel precursor system, an autogenous tissue growth-promoting device, in spite of its ingenuity and its surgical elegance, has received only limited usage. At technique for peripheral blood vessels by several authors. In the latter period, this laboratory also undertook similar work. The results of seven implantations in dogs and two in patients are reported here in the context of a program on the evaluation of blood vessel substitutes, their mode of operation and their long term performance. The clinical status and the pathology of the grafts at time of failure were investigated using techniques of scanning electron microscopy. This work confirms the findings of other centres regarding the generally unsatisfactory performance of the Sparks-Mandril system. Possible causes for failure in mandril-formed blood vessels are discussed.

Adult↗
PubMed1979

[Should phlebitis of the limbs be treated surgically (author's transl)].

Controversy persists between partisans of medical treatment and partisans of wide surgical indications. In iliocaval phlebitis, the authors defend surgery insofar as the operation is restorative, whilst remaining "reasoned" in terms of the lesions and the numerous factors involved. Experience of 90 cases of phlebitis treated over the past two years has shown that restoration may be obtained and maintained in more than half the number of cases and that prophylactic partial venous occlusion proved necessary in only 30% of cases. Absence of any deaths confirmed the value of this approach.

Age Factors↗
PubMed1979

Study of thioridazine cardiotoxic effects by means of His bundle activity recording.

The effect of thioridazine on sinusal automaticity, myocardial excitability and auriculoventricular conduction have been studied in dogs by measuring the spontaneous heart rate, the effective refractory period of the atrial contractile tissue, the time of auriculonodal and infrahisian conduction. Chloralose anaesthetized dogs were administered 10 mg/kg thioridazine hydrochloride via intravenous route. While sinusal automaticity was not altered, conduction times were prolonged in the suprahisian and mainly the infrahisian part and the atrial refractory period increased. These effects are related to quinidine-like properties and consistent with cardiotoxic effects previously reported in clinical practice.

Animals↗
PubMed1979

[Effect of levomepromazine on atrioventricular conduction tissue (author's transl)].

The effect of levomepromazine on sinusal automaticity, myocardial excitability and auriculoventricular conduction have been studied in dogs by measuring the spontaneous heart rate, the effective refractory period of the conduction system, the time of auriculonodal and infrahisian conduction. Chloralose-anaesthetized dogs were administered 5 mg/kg levomepromazine via IV route and 10 mg/kg one hour later. While sinusal automaticity is never altered, the other parameters studied were modified only when high doses were used. Therefore these quinidine-like effects are very unlikely to come up even following suicidal massive ingestion of levomepromazine.

Animals↗
PubMed1979

Revascularization of the spinal cord by micro-anastomoses in dogs.

The severity of ischemic lesions in the spinal cord justifies attempts at its surgical revascularization. The experiments consisted of: (1) creating devascularization of the conus medullaris by ligation of all the lumbo-sacral collaterals of the aorta, and (2) revascularizing the lumbo-sacral rachidian circulation by performing an end-to-side anastomosis between the caudal mesenteric artery and the 5th left lumbar artery (from which in the dog the Adamkiewicz artery generally arises). After two-months, the patency rate of the 20 cases was 85%. Such a procedure of revascularization could be useful in man in cases of interruption of the arterial supply of the spinal cord.

Angiography↗
PubMed1979

[Grave obstetrical phlebitis. Physiopathology, diagnosis and treatment (6 case histories) (author's transl)].

The authors detail their concepts of the physiopathology, the diagnostic methods and the treatments of grave puerperal phlebitis, having seen six cases in their two departments recently. They consist of 5 cases of iliofemoral thrombosis, 2 of whom were diagnosed during their pregnancies and 3 others whom were diagnosed after delivery. One of these died of pulmonary embolus: and there was one case of thrombosis of the right ovarian vein during post-partum. Over and above the classical factors that predispose to this condition in pregnancy, the authors draw attention to the anatomical constitutional factors that have been observed by Cockett in the physiopathology of these cases. The diagnosis is made using non-invasive methods: Doppler, plethysmography, labelled fibrinogen and isotope phlebography after delivery, supplemented when the results are positive by radiography of the iliac and vena caval systems which alone gives a precise diagnosis of the site. Therapeutic possibilities change according to the time that the condition is perceived, according to the topography of the lesions, and according to the existence or non-existence of moving thrombi. The treatment is directed to avoiding the complications of emboli and to preventing secondary functional sequellae. Finally the gynaecological problems of contraception and of further pregnancies are considered.

Adolescent↗
PubMed1978

[Mechanism of biosynthesis of glycoconjugates at the level of the arterial walls after contact with alloplastic materials (author's transl)].

The object of this work was to show that here exists after contact with foreign substances, a construction of protein, glycoprotein and mucopolysaccharide macromolecules at the level of the intima of the great vessels. Woven Dacron prostheses have been implanted in the arterial circulation of dogs (on the subrenal abdominal aorta). After removal of vascular segments, we carried out a subcellular fractioning, controlled and studied in an acellular system in vitro the activity of the glycosyltransferases implied in the construction of glycan chains of glyccproteins. The results are discussed in relation to the duration of implantation of the prosthesis. The modifications observed differ according to the position of the sugars in the glycan chains, in particular as far as sialic acid is concerned, and lead to an interpretation of the mechanism of endovascular reactions when faced with foreign material.

Animals↗
PubMed1978

Mechanism of glycoconjugates biosynthesis in the vascular wall with external circular constraint.

Extrinsic local constraints, realised on dogs aorta are responsible for parietal lesions in the form of thickening of the arterial wall. Histological changes in the intima and media are characteristic of processes of degeneration destruction and cellular regeneration, superposed on sub-endothelial proliferation accompained by partial or total destruction of endothelial cells in the intimal layer. In addition to histological changes, there were perturbation in enzymatic activities of glycosyltransferases responsible for macromolecular constructions in the intima. Microsomic enzymes studied were: N-acetyl-glucosaminyl-transferase, sialyl-transferase and N-acetyl-galactosaminyl-transferase, and two glycosyl-transferases located in the soluble cytoplasmic phase: fucosyl and xylosyl-transferase. The changes observed were different according to the position of the sugars in the glycoprotein chains. For example the variation of fucosyl-transferase activity is significant: it disappears in group where the sialyl-transferase activity is enhanced. The transfer of xylose is decreased. Finally, changes observed in hexosaminyl-transferase activities were parallel.

Animals↗