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Biomedical subjects

H Bricaud

Publications and source records attributed to H Bricaud.

At least 73 records · Page 4Linked to original sources

[Prevalence, signification and prognosis of auricular arrhythmia in dilated myocardiopathies. Apropos of 236 cases].

A population of 236 patients with dilated cardiomyopathy (DCM) was studied and followed up for an average of 38.8 +/- 27 months. The most common atrial arrhythmia was atrial fibrillation (AF) which was observed in 27 p. 100 of cases. Patients with AF (n = 43) and without it (n = 193) at the time of diagnosis were compared: the subjects with AF were older (p = 0.036), had a higher left ventricular ejection fraction and lower end diastolic pressures (p = 0.022). AF was associated with mitral valve prolapse (p = 0.007) and with signs of adiastole (p = 0.0015); the most significantly correlated variable was echocardiographic dilatation of the left atrium (p = 0.0012). AF was the presenting symptom of DCM in 13 cases (5.5 p. 100); in 10 cases (4 p. 100) it was the main clinical and therapeutic problem, realizing an arrhythmic form of DCM. Electrical conversion was successful in 7 out of 11 patients with a 2 year follow-up: 3 patients remained in sinus rhythm for over 6 years and have no clinical symptoms, posing the problem of the dominant if not exclusive underlying role of AF in these cases of DCM. An example illustrated by several echocardiographic examinations is presented. Embolic complications were observed in a quarter of the cases with AF and this arrhythmia was present in half the patients with embolic phenomena. However, the prognosis in the groups with and without AF was not significantly different.

Adult↗

[Endocavitary electrocautery of a right anterior bundle of Kent].

The authors report another case of successful endocavitary electrocautery in a young woman with Wolff-Parkinson-White syndrome. The pre-excitation was controlled by the administration of two 250 joule electrical shocks applied to the atrial origin of the right anterior bundle. The clinical and laboratory tolerance were satisfactory. Although these results are encouraging, other studies are required in order to define the indications and protocols of electrocautery of accessory pathways.

Adult↗

Regeneration of the antiviral drug (E)-5-(2-bromovinyl)-2'-deoxyuridine in vivo.

The highly potent and selective antiherpes drug BVdUrd [(E)-5-(2-bromovinyl)-2'-deoxyuridine] is cleared within 2-3 hours from the bloodstream upon intraperitoneal administration to rats. It is degraded to BVUra [(E)-5-(2-bromovinyl)uracil] and this inactive metabolite is cleared very slowly from the bloodstream so that 24 hours after the administration of BVdUrd, BVUra is still detectable in the plasma. This contrasts with several other 5-substituted uracils, i.e. 5-fluorouracil, 5-iodouracil, 5-trifluorothymine and thymine itself, which are, like their 2'-deoxyuridine counterparts FdUrd, IdUrd, F3dThd and dThd, cleared from the plasma within 2-3 hours. The injection of dThd or any of the other 5-substituted 2'-deoxyuridines at 3 hours after the injection of BVdUrd, that is at a time when BVdUrd has disappeared completely from the circulation, results in the re-apparition of BVdUrd in the plasma. Apparently, BVdUrd is regenerated from BVUra following the reaction catalyzed by pyrimidine nucleoside phosphorylases : BVUra + dThd----BVdUrd + Thy. BVdUrd can even be generated de novo if dThd (or FdUrd, IdUrd or F3dThd) are administered 3 hours after a preceding injection of BVUra. These findings represent a unique example of the (re)generation of an active drug from its inactive metabolite in vivo.

Animals↗

Global left ventricular function and regional wall motion in pure mitral stenosis.

Global left ventricular function (LVF) and segmental wall motion of the left ventricle are registered in 113 patients presenting a pure mitral stenosis (MS) and in a control group of 50 individuals. The segmental wall motion is measured on the end-diastolic-end-systolic frames of the left ventricle, obtained from right anterior oblique (RAO) monoplane cineangiography. Measurement of the segmental wall shortening is performed using the Stanford method. Group 1 includes 68 patients (60% of the total number of patients studied). These patients show no pathological contraction abnormality. In this group, the global LVF is not different from the control group. Group 2 includes 45 patients (40% of the total) for whom contraction abnormalities are present: anterior hypokinesis in 20% of the cases (anterior area mean shortening (AAS) = 18 +/- 8%; p less than 0.001 vs. group 1 and control group), and posterior hypokinesis in 20% of the cases (posterior area mean shortening (PAS) = 9.8 +/- 5.8%, p less than 0.001 vs. group 1 and control group). In this group, global LVF is impaired; ejection fraction (EF) = 0.57 +/- 0.1% (p less than 0.001 vs. group 1); velocity of circumferential fiber shortening (VCF) = 1 +/- 0.3 circ/s (p less than 0.001 vs. group 1); enddiastolic pressure (EDP) = 11 +/- 5 mmHg (p less than 0.01 vs. group 1). Segmental contraction abnormalities appear to be the main factor involved in the global LVF impairment. Segmental wall motion abnormalities could be related to subvalvular fibrosis, or LV filling difficulties, or principally, to a possible interplay between the right and the left ventricles.

Adult↗

Prostacyclin synthesis by proliferative aortic smooth muscle cells. A kinetic in vivo and in vitro study.

The capacity of arterial SMCs to produce PGI2 when stimulated by exogenous AA was studied in proliferative and confluent cultured cells and at different periods following endothelial denudation in vivo. PGI2 production per cell was doubled during the exponential growth-phase in culture. By contrast, increased PGI2 formation did not correlate with mitotic activity in intimal regeneration tissue but with the presence of SMCs in a synthetic phenotype. The present results suggest a potential role for PGI2 in SMC differentiation and proliferation.

Animals↗

Purification of human alpha 1 antiprotease-pancreatic elastase complex. Interaction with homologous elastin.

A human alpha 1-antiprotease (alpha 1.AP)-human pancreatic elastase ( HPE11 ) complex was isolated from plasma, or prepared from commercial alpha 1.AP. The complex was identified and isolated by affinity chromatography, using Concanavalin A or IgG anti-elastase as ligands, in association with Sephacryl gel filtration. The alpha 1.AP- HPE11 complex was shown to bind with aorta and with purified aortic elastin. In both cases, the complex exhibited elastinolytic activity.

Aorta↗

[Comparative study of a slow-release quinidine preparation and flecainide administered in 2 daily doses for the treatment of extrasystole].

The new anti-arrhythmic agent flecainide was compared in a single-blind cross-over study to arabogalactane quinidine sulfate in the treatment of stable chronic extrasystole, using a fixed twice-daily dose protocol. Results were assessed by the Holter method. 12 patients (7 men and 5 women) with an average age of 56.5 were selected on the basis of stable and essentially ventricular extrasystole (VES) in 11 cases, and essentially atrial extrasystole (AES) in the remaining case. All patients however had some VES and 6 had some AES, and 5 patients had bursts of VES. The protocol provided for four sequences lasting one week each: one fixed, for selection, and the other three random, flecainide (375 mg), quinidine (660 mg), or placebo (2 doses). Data on each were recorded for Holter analysis. Statistical comparison of results was performed by studying variances on an equilibrated block. Comparison between the selection and placebo sequences showed the stability of the arrhythmia whatever its type. Against ectopic complexes as a whole, only flecainide had significant activity (p less than 0.01). Against AES, both compounds were active (p less than 0.05), quinidine more than flecainide (-73%/63%: a non-significant difference). Only flecainide was active against VES (-88.5%). Quinidine did not significantly reduce VES (-56%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Left ventricular global and segmental function in pure mitral valve prolapse with poor tolerance for exertion].

Poor effort tolerance is observed in a small percentage of cases of idiopathic mitral valve prolapse (IMVP). The aim of this study was to assess the possible left ventricular dysfunction in such cases, responsible for poor effort tolerance. Left ventricular function and segmental wall motion were studied retrospectively in a group of 17 patients with IMVP. The patients, average age 53 +/- 12 years, had poor effort tolerance (ST segment depression of 2 to 4 mm in 15 cases, drop in blood pressure in 6 cases) justifying catheter and angiographic studies. All patients had IMVP confirmed on RAO left ventriculography. There was no associated mitral regurgitation or coronary artery disease. Left ventricular function was studied by parameters of global function (systolic and diastolic parameters, volume measurements) and by a quantitative study of segmental wall contraction. The method used for studying regional wall motion was an application of the Stanford method in which segmental shortening is studied over all the endocavitary contour of the LV during an angiographic cycle filmed at 50 frames/second in the RAO projection. The time and velocity amplitudes of wall motion were measured during systole and diastole. The same methodology was applied to 21 normal control subjects. The results showed abnormal volumic compliance and wall motion in the IMVP group. Asynergy was mainly confined to the antero-lateral wall of the LV. The amplitude of contraction was generally normal but the contraction was slower and finished earlier. In the same zone, relaxation was abnormally early and lasted longer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Efficacy and value of fibrinolytic agents in chronic proximal venous thrombosis of the lower limbs].

Forty patients (mean age = 56 +/- 17 years) hospitalized for proximal venous thrombosis of the lower limbs of over 7 days duration were treated with fibrinolytic drugs: streptokinase (SK) 28 cases, urokinase (UK) 12 cases. The efficacy of fibrinolytic therapy was assessed by phlebography before and 4.5 +/- 2 days after onset of treatment. A phlebographic score based on Marder's method was used to quantify the thrombosis. The repermeabilisation of venous branches was also noted. The results show an overall efficacy of fibrinolytic drugs: total lysis was observed in 6 patients and partial thrombolysis in 18 patients. The overall reduction of the phlebographic score was -2.8 +/- 3.9, and the rate of repermeabilisation of the femoral veins was over 50%. Streptokinase seemed to be the most effective drug. Better results were obtained when the thrombosis was treated early and was proximally situated, but good results were also observed in cases of total thrombosis with a floating thrombus. Effective fibrinolysis was observed in thromboses of up to 3 months duration. There was no correlation between biological efficacy and clinical symptoms. In conclusion, fibrinolytic drugs are partially effective in semi-recent or chronic venous thrombosis and their usefulness should not be overlooked, especially in cases of persistent thrombosis of the femoral veins.

Adult↗

[Endocavitary His bundle fulguration in the treatment of resistant supraventricular arrhythmia].

Nine patients aged 47 to 74 years underwent endocavitary destruction of the bundle of His because of paroxysmal arrhythmias resistant to medical therapy. Four patients had paroxysmal atrial fibrillation, 2 had paroxysmal atrial flutter, 1 had reentrant atrial tachycardia, 1 had paroxysmal atrial tachycardia and 1 had an intranodal reentrant tachycardia. One patient had already undergone "surgical ablation" of the His bundle without success. A tripolar or bipolar catheter was introduced via the femoral vein and the His potential localised by bipolar and then unipolar recordings. The lead with the greatest His potential was connected to an external defibrillator and the other pole connected to a metal plaque positioned under the patient's left shoulder. An electrical shock of 200 to 400 joules was administered, in some cases repeatedly. Eight of the 9 patients developed complete atrioventricular block after the shock. This was only temporary in 3 cases, necessitating another shock in 2 cases; the procedure was not repeated in the 3rd case. After 30 minutes of persistent AV block a pacemaker was implanted; 7 of these 8 patients had VVI and I patient (intranodal reentry) DDD pacing. The follow-up period ranges from 1 to 18 months. None of the patients have had symptoms of paroxysmal arrhythmia; in the long-term, there was one initial failure. Of the other 8 cases, 4 remain in complete AV block, 2 have 2nd degree and 21st degree AV block. Three patients have associated antiarrhythmic therapy with quinidine or verapamil. No side effects were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Phosphorolysis of (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) and other 5-substituted-2'-deoxyuridines by purified human thymidine phosphorylase and intact blood platelets.

Various 5-substituted-2'-deoxyuridines (dUrd), including 5-ethyl,5-propyl-, 5-trifluoromethyl-, 5-hydroxymethyl-, 5-formyl-, 5-vinyl-, (E)-5-(2-chlorovinyl)-, (E)-5-(2-bromovinyl)-, 5-fluoro-, 5-chloro-, 5-bromo-, 5-iodo-, 5-cyano-, 5-thiocyano-, 5-nitro- and 5-amino-dUrd, were shown to be effective substrates for the thymidine (dThd) phosphorylase isolated from human blood platelets. Some of dUrd analogs, i.e. the highly potent and selective antiherpes agent (E)-5-(2-bromovinyl)-dUrd, were degraded more rapidly than the natural substrates, dUrd and dThd. All dUrd analogs were also readily catabolised by intact human blood platelets. The potent inhibitors of thymidine phosphorylase, 6-amino-thymine and 6-amino-5-bromo-uracil, strongly inhibited the phosphorolysis of (E)-5-(2-bromovinyl)-dUrd by both purified enzyme and intact platelets.

Blood Platelets↗

Formation of monohydroxyeicosatetraenoic acids from arachidonic acid by cultured rabbit aortic smooth muscle cells.

In addition to the well established cyclooxygenase pathway, cultured aortic smooth muscle cells convert arachidonic acid to several polar metabolites identified by high performance liquid chromatography and gaz chromatography-mass spectrometry. 15-Hydroxyeicosatetraenoic acid, 12-Hydroxyeicosatetraenoic acid and 5-Hydroxyeicosatetraenoic acid are the major products formed. These observations indicate that the rabbit aortic smooth muscle cells are a potential source of lipoxygenase products and raise the possibility that this pathway of arachidonic acid metabolism can influence the biological functions of arterial myocytes under normal and pathological conditions.

Animals↗