Search PubMed⌕ Search

Biomedical subjects

H Bricaud

Publications and source records attributed to H Bricaud.

At least 109 records · Page 6Linked to original sources
PubMed1982

[Outcome of echocardiographic vegetations in bacterial endocarditis during and after anti-infective therapy].

Echocardiography is a practical and reliable method of detecting endocardial vegetations. The aim of this study was to assess the course of echocardiographic vegetations in bacterial endocarditis under anti infectious therapy and to assess the prognostic significance of the vegetations. Twenty four patients with echocardiographic signs of vegetations were included in a standardised protocol: M mode and 2D examination at the beginning and at the end of medical treatment and when possible after bacteriological cure (average period of follow-up 16 +/- 6 weeks). Special attention was paid to the volume (assessed I to III) and acoustic density of the vegetations. Fifteen patients underwent surgery (62.5%). The size of the vegetations did not differ significantly from that observed in the other patients. The size of the vegetations remained constant during medical therapy and after bacteriological cure in 2/3 of cases. The vegetations grew during medical therapy (even when the patients were apyrexic) in 29% of cases, and even after a 40 day course of anti infectious therapy in 2 cases. The size of the vegetations decreases in 3 cases during treatment (2 cases of embolisation) and in 2 cases after bacteriological cure (without embolisation). No correlations could be drawn between the acoustic density of the vegetations and the outcome. In conclusion, the presence of a large vegetation in bacterial endocarditis does not in itself mean a poor prognosis. However, these large vegetations are often associated with severe mutilating lesions (62.5% in our series). The size of the vegetations remained unchanged during and after medical treatment in two thirds of cases.

Adult↗
PubMed1981

Catabolism of thymidine in human blood platelets: purification and properties of thymidine phosphorylase.

A pyrimidine nucleoside phosphorylase was partially purified from human blood platelets. The purified enzyme, as well as crude enzyme preparations, catalyses the phosphorolysis of thymidine and deoxyuridine, but not of uridine, and is able to catalyse direct pentosyl transfer from these deoxyribonucleosides to uracil or thymine; this enzyme has the properties of a thymidine phosphorylase. It has a molecular weight of about 110,000 and is composed of two identical subunits; it is phosphate dependent, has a maximal activity at a pH value of 5.7, and an isoelectric point of 4.4. This enzyme was mainly of cytoplasmic origin. Although platelet thymidine phosphorylase could promote the degradation or synthesis of thymidine, intact platelets degraded thymidine but were not able to synthesize thymidine from thymine. Blood platelets may play an important role in the degradation of plasma thymidine.

Blood Platelets↗
PubMed1981

[Cerebral emboli due to subclinical heart disease. Value of thorough investigations (author's transl)].

In a series of 250 cases of cerebral vascular accident, the authors have selected 12 patients whose embolus appeared to have originated in the heart, although this could not be confirmed by clinical examination, ECG, Holter system monitoring and echocardiographic studies. Angiocardiography, complemented or not by His bundle exploration and/or coronary arteriography, revealed the presence of a heart disease likely to produce emboli in 11 cases, and in 8 cases, this was prolapsed mitral valve. These 11 cases represent 4.5% of the whole series and 22% of cases with emboli of suspected cardiac origin. Thorough cardiological studies, therefore, seem to be justified in young adults presenting with stroke. The high incidence of prolapsed mitral valve is in keeping with recently published data.

Adolescent↗
PubMed1981

Collagen synthesis in organ culture of normal and atherosclerotic aortas.

Using pulse-label experiments in organ culture, collagen synthesis was studied in aortas from healthy and atherosclerotic specimens. Investigations were carried out on human atherosclerotic plaques as well as in the mini-pig in which atherosclerosis occurred spontaneously, and in the rabbit where atherosclerosis was experimentally induced by cholesterol-enriched feeding. When compared to total protein synthesis, the percentage of newly synthesized collagens measured as radioactive pepsin-resistant material, decreased with age in healthy specimens, whereas it remained at a higher level when the aortas were atherosclerotic. Subsequent molecular sieve chromatography of the radioactivity pepsin-resistant material allowed the separation type I collagen from type III collagen and their relative quantification. The results showed that the newly synthesized type III collagen accounted for 16-31% in aortic explants from young animals, for 30-36% when the explants were derived from older specimens and for 35-48% when the tissues were atherosclerotic.

Animals↗
PubMed1981

Echocardiographic assessment of left ventricular filling characteristics after mitral valve replacement with the St Jude medical prosthesis.

The major cause of late mortality and morbidity after prosthetic valve replacement is thromboembolism. The nidus for initiation of thrombus formation has been blood metal interfaces, and a new valve--the St Jude prosthesis--has therefore been developed without any metal components. We have assessed echocardiographically in 27 patients the effects of this valve on left ventricular filling characteristics when inserted in the mitral position and compared the findings with those in patients having mitral valve replacement with Starr-Edwards or Björk-Shiley prostheses and with those in patients undergoing repair of the native mitral valve. Echocardiograms were recorded and digitised. Measurements were made of the peak rate of increase of dimension (dD/dt) and duration of rapid filling. Values for the St Jude valve were 13.2 +/- 3.4 cm/s and 160 +/- 40 ms, respectively. The peak rate of dD/dt increase was significantly greater than with either the Björk-Shiley valve or the Starr-Edwards valve and was comparable with findings in mitral valve repair. The duration of the rapid filling phase was not significantly different from control values but was less than that of the Starr-Edwards valve. This study indicates that the new St Jude medical valve is less obstructive than either the Björk-Shiley or Starr-Edwards prostheses. This together with its low thrombogenicity suggests that further trials of this new valve should be undertaken.

Adolescent↗
PubMed1981

Filterability and cerebro-vascular thrombosis. Study on the mechanism.

The filterability of red cells was altered in 100 patients with CVA. This disorder appeared to be correlated with risk factors and haemostatic disturbances. The mechanism which links thrombosis with the filterability disorder, mainly depended upon a plasmatic factor. This factor disappeared after the red cells were carefully washed. The hypothesis of products originating from the thrombotic areas amd vasculo-endothelial lesions (mainly fibrin-related products) was supported.

Adult↗
PubMed1981

A specific one step method for the isolation of pancreatic elastase; its use to characterize aortic elastase.

Elastase was purified from an acetone-ether powder of porcine pancreas by a one step affinity chromatography procedure on IgG-Sepharose 4B. The IgG was derived from a rabbit immunized with porcine pancreatic elastase and was itself isolated by affinity chromatography on elastase immobilized on the same matrix. The column was calibrated with a known elastase preparation under standardized conditions. Direct isolation of elastase from pancreatic extracts yielded approximately 90 mg from two pancreas. The enzymatic activity and electrophoretic migration in SDS-polyacrylamide gel of the purified elastase were equal to those of the purest commercially available enzymes. Application of this method to aorta of young pigs suggests the presence of active elastase in the aorta.

Animals↗
PubMed1981

[Electrophysiological properties of acute intravenous sotalol in man].

The electrophysiological properties of of 0,6 mg/Kg SOTALOL administered intravenously were studied in 15 subjects aged between 32 and 81 years. The following parameters were recorded: sinus rate (SR), corrected sinus node recovery time (SNRT), sinoatrial conduction time (SACT), PA interval, right atrial effective refractory period (ERP), right atrial functional refractory period (FRP), AH interval at rest, at 100 bpm, Luciani-Wenckebach point (LWP), AV node ERP and FRP, HV interval, His-Purkinje ERP, right ventricular ERP, corrected QT interval. At this dosage, intravenous SOTALOL displays two types of behaviour: --That common to the betablocker drugs: slowing SR by 16%, increasing the AV nodal conduction, increasing the AH interval at rest (5%), at 100 bpm (23%), increasing AV nodal ERP (26%) and FRP (20%), decreasing the LWP (18%). --Other properties: increasing intraatrial PA interval (3%), increasing right atrial ERP (II%), FRP (I7%), increasing right ventricular ERP (8%), increasing His-Purkinje ERP (when measurable) (about 6%), no change in corrected QT interval. At this dosage, SOTALOL exhibits electrophysiological behaviour similar to drugs in Class III (Touboul): those with a "wide electrophysiological spectrum".

Adult↗
PubMed1980

[Anti-elastase of human pancreas: preparation and biological interest].

The present paper deals with the use of a new technique in type II human pancreatic elastase studies based on the use of a reversible immune-adsorbent which provides a unique specificity. According to the type of ligand linked on activated Sepharose, the elastase or its antibody in Rabbit could be obtained, in very pure form, in a one step process. The anti-human pancreatic elastase II, which specifically inhibits the enzyme, may be used in therapy whenever the elastase-inhibitor system becomes unbalanced.

Animals↗
PubMed1980

Prostacyclin production by cultured smooth muscle cells from atherosclerotic rabbit aorta.

Prostacyclin (PGI2) synthesis seems to be one of the major physiological mechanisms involved in regulating platelet and vessel wall interactions. PGI2 is produced in large amounts by vascular endothelial cells, and vascular smooth muscle cells (SMC) also produce significant quantities. The capacity of SMC to produce PGI2, especially after endothelial injury, seems to be of importance. It is probably this type of situaton that is involved in the atherosclerotic process: experimental atherosclerosis in rabbits has been associated with a severe decrease in PGI, synthesis by arteries. Lipid peroxide accumulation within the arterial wall or in the plasma may also be involved in this process. Using arterial SMC in culture, we demonstrate here that, in comparison with healthy cultured cells, cells originating from atherosclerotic aorta have a decreased capacity to produce PGI2. The results were obtained using biological and radiochemical techniques and were confirmed by GC-MS. They suggest a potential role for PGI2 in inhibiting the atherosclerotic process.

Animals↗
PubMed1980

Biochemical and immunological studies of fibroblasts derived from a patient with Ehlers-Danlos syndrome type IV. Demonstrate reduced type III collagen synthesis.

Fibroblasts derived from a skin biopsy of a patient with the Ehlers-Danlos syndrome (EDS) type IV were cultured in monolayer. The amount of collagen synthesized during a 24-h pulse was not different from that found with normal fibroblasts. Chromatographic procedures and immunofluorescence staining showed a normal synthesis of type I procollagen and collagen but a deficiency in synthesis of type III procollagen and collagen. This could be corroborated by radioimmuno assays showing a reduction in type III procollagen by about 90%. The secretion and degradation of collagens was not altered. The results demonstrate that the molecular defect in this particular patient is due to an impairment of the mechanism controlling the gene expression for type III procollagen.

Cells, Cultured↗