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L Piérard

Publications and source records attributed to L Piérard.

44 records · Page 3Linked to original sources

Characterization of a recombinant fusion protein of the finger domain of tissue-type plasminogen activator with a truncated single chain urokinase-type plasminogen activator.

Human recombinant single chain urokinase-type plasminogen activator (recombinant scu-PA) and a hybrid between human tissue-type plasminogen activator (t-PA) and scu-PA, obtained by ligation of cDNA fragments encoding the NH2-terminal region (amino acids 1-67) of t-PA and the COOH-terminal region (amino acids 136-411) of scu-PA, were expressed in a mammalian cell system. The proteins were purified from conditioned culture media containing 2% fetal calf serum by chromatography on zinc chelate-Sepharose, immunoadsorption chromatography on an insolubilized murine monoclonal antibody directed against urokinase, benzamidine-Sepharose chromatography, and Ultrogel AcA 44 gel filtration. Between 180 and 230 micrograms of the purified proteins were obtained per liter of conditioned medium, with a yield of approximately 18% and a purification factor of 720-1900. On sodium dodecyl sulfate gel electrophoresis under reducing conditions, the proteins migrated as single bands with approximate Mr 50,000 for recombinant scu-PA and Mr 43,000 for the t-PA/scu-PA hybrid. Following conversion to urokinase with plasmin, the proteins had a specific amidolytic activity comparable to that of natural scu-PA. Both proteins activated plasminogen directly with Km = 0.53 and 1.4 microM and k2 = 0.0034 and 0.0027 s-1, respectively. Both proteins did not bind specifically to fibrin and had a comparable degree of fibrin selectivity as measured in a system composed of a whole human 125I-fibrin-labeled plasma clot suspended in human plasma. It is concluded that this chimeric protein, consisting of the NH2-terminal "finger-like" domain of t-PA and the COOH-terminal region of scu-PA, has very similar enzymatic properties as compared to scu-PA, but has not acquired the fibrin affinity of t-PA.

Adenocarcinoma↗

Incidence, clinical significance and prognosis of ventricular fibrillation in the early phase of myocardial infarction.

Of 1265 patients admitted to the CCU with the diagnosis of acute MI, 96 (7.6%) developed ventricular fibrillation within 72 hours following admission. Of these 96, 35 (36.5%) had secondary VF associated with left ventricular failure; they had a high in-hospital mortality of 57.1%. The remaining 61 (63.5%) had primary VF, i.e. VF occurring in the absence of significant LV failure. Fourteen of these (23%) died in hospital: 9 due to PVF (3 during the first episode, 6 during a recurrence). This mortality figure was significantly higher (P less than 0.001) than the mortality of 10% seen among patients who did not experience VF. Primary VF showed a recurrence rate of 20%. Compared with the 1061 patients who left the hospital without primary VF, the 61 subjects with this rhythm disorder were older, had larger infarcts and more frequent complications, such as pericarditis, conduction abnormalities, frequent ventricular premature contractions and signs of right ventricular failure. These findings, in contrast with a widely held view, suggest that primary VF may carry a guarded prognosis.

Adult↗

Two-dimensional echocardiographic guiding of endomyocardial biopsy.

Two-dimensional echocardiography provides adequate spatial orientation and anatomic definition. Eighteen consecutive patients undergoing myocardial biopsy had concomitant two-dimensional echocardiography during 22 biopsies of five to six samples each. The transducer was placed at the apex and in the subcostal area and four-chamber views were used. The bioptome was seen entering the right atrium and crossing the tricuspid valve to the right ventricle. The catheter was then manipulated under two-dimensional echocardiography and the tip's position was strictly adapted, using two different classic views before sampling. The success rate in visualizing the forceps and in defining the site of sampling was 100 percent, and no complication was noted. Radiation exposure was largely reduced. Two-dimensional echocardiography to guide endomyocardial biopsy may reduce the risk of perforation by a better anatomic definition of the sampling site. It permits sampling from different ventricular sites or from the same site during serial procedures for monitoring evolution or treatment.

Adult↗

Videodensitometric processing of contrast two-dimensional echocardiographic data.

We developed a computer program to analyze videodensity changes due to contrast appearance within a given operator-designated rectangle using two-dimensional echocardiograms previously recorded on videotape. Videodensity curves have been obtained from two-dimensional echocardiographic recordings in 14 patients after a total of 32 injections of 5% dextrose solution into the left ventricle during cardiac catheterization. The resulting videodensity vs time curves have some characteristics of indicator-dilution curves. The decay phase of these curves is largely mono-exponential. Potential clinical applications of this technique in measurement of ejection fraction, cardiac output and shunt quantification are discussed, as well as some potential limitations.

Computers↗

Echocardiographic aspects of cardiac amyloidosis.

We report the M-mode and two-dimensional echocardiographic findings in a patient with familial amyloidosis. The diagnosis was made by the clinical picture and histologic evidence of amyloid in peripheral nerve biopsy. Though the patient had no clinical sign of heart failure, extensive involvement of the heart was demonstrated by echocardiography. M-mode echocardiography revealed increased right ventricular wall thickness in conjunction with symmetric increase in left ventricular wall thickness. On two-dimensional echocardiography, the entire interventricular septum and the papillary muscles were more dense than normal. These high density echoes had a "granular and sparkling" pattern. This case shows that cardiac amyloidosis can be diagnosed in the pre-clinical, asymptomatic state by M-mode and two-dimensional echocardiography. When symptomatic, confusion with constrictive pericarditis may be avoided non-invasively.

Adult↗

[Contrast echocardiography. Methods, applications and prospects].

Contrast echocardiography is a diagnostic technique which consists of the injection of a physiological, echogenic solution into the blood stream and mode M or two-dimensional echocardiographic analysis of the echoes produced in order to assess the features of intracardiac blood flow. It is useful for the identification and confirmation of normal and abnormal cardiac structures, the demonstration or exclusion of intracardiac and extracardiac shunts and the diagnosis of valvular incompetence. Many other clinical applications are in the process of being developed. The prospects for future research consist of the discovery of contrast agents capable of crossing the capillary bed and the development of CT techniques for the quantification of the contrast.

Cardiac Catheterization↗