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Biomedical subjects

F Boulay

Publications and source records attributed to F Boulay.

At least 73 records · Page 4Linked to original sources
PubMed1986

[Clinical, echocardiographic and evolutive aspects of right atrial thrombosis].

The clinical and echocardiographic features of right atrial thrombi were examined in 9 patients, 5 men and 4 women aged 16 to 86 years. The 2D echocardiographic diagnosis was confirmed at autopsy (4 cases) or by the association of severe recurrent pulmonary embolism (5 cases). Three patients had associated ischaemic heart disease and on patient had dilated cardiomyopathy. The clinical presentation was: acute cor pulmonale (5 cases including 2 patients which biventricular myocardial infarction), chronic post-embolic cor pulmonale (1 case), tricuspid valve obstruction (1 case), general ill health with pyrexia (1 case) and heparin-induced thrombocytopenia (1 case). Predisposing factors included: absence of anticoagulent therapy (7 cases), previous supraventricular arrhythmias (2 cases) and right ventricular failure (6 cases, including 2 of right ventricular infarction). In 2 patients the thrombi were relatively immobile and had a wide base of implantation on the interatrial septum; in 1 patient, multiple thrombi were observed lining the right heart cavities from the inferior vena cava to the pulmonary infundibulum. In the other 6 patients, the thrombi were very mobile with a visible pedicule of implantation (2 cases) or totally free (4 cases). The variable polylobulated appearances, completely irregular whirling motion and intermittent prolapse into the tricuspid valve were characteristic features of the latter 4 cases. They disappeared spontaneously (2 cases) or after fibrinolytic therapy (2 cases) in under 36 hours. Three patients were operated with one postoperative death. The global hospital mortality was 22%. The present occasional detection of right atrial thrombosis will certainly become more common if patients with pulmonary embolism, right ventricular infarction or deep venous thrombosis are systematically examined by 2D echocardiography in the acute phase of their illness.

Adolescent↗
PubMed1986

[Isotopic exercise tests and selection of cases of inferior infarction requiring coronarography].

Exercise tests involving isotopes were evaluated in 38 subjects presenting inferior myocardial necrosis. Cardiographic data were used to calculate sensitivity and specificity of the method in detection of subjects requiring surgical treatment. Sensitivity was 90% and specificity 62% when three criteria were employed: ECG of positive exertion, reversible diminished accumulation of thallium 201 outside the necrotic site or decrease in the fraction of ejection force. Examination of the fraction of ejection force improved the results of myocardial scanning using thallium and increased detection of subjects requiring surgery from 61% to 90%.

Adult↗
PubMed1985

Photoaffinity labeling of mitochondrial adenosinetriphosphatase by 2-azidoadenosine 5'-[alpha-32P]diphosphate.

2-Azidoadenosine 5'-diphosphate (2-azido-ADP) labeled with 32P in the alpha-position was prepared and used to photolabel the nucleotide binding sites of beef heart mitochondrial F1-ATPase. The native F1 prepared by the procedure of Knowles and Penefsky [Knowles, A. F., & Penefsky, H. S. (1972) J. Biol. Chem. 247, 6617-6623] contained an average of 2.9 mol of tightly bound ADP plus ATP per mole of enzyme. Short-term incubation of F1 with micromolar concentrations of [alpha-32P]-2-azido-ADP in the dark in a Mg2+-supplemented medium resulted in the rapid supplementary binding of 3 mol of label/mol of F1, consistent with the presence of six nucleotide binding sites per F1. The Kd relative to the reversible binding of [alpha-32P]-2-azido-ADP to mitochondrial F1 in the dark was 5 microM in the presence of MgCl2 and 30 microM in the presence of ethylenediaminetetraacetic acid. A linear relationship between the percentage of inactivation of F1 and the extent of covalent photolabeling by [alpha-32P]-2-azido-ADP was observed for percentages of inactivation up to 90%, extrapolating to 2 mol of covalently bound [alpha-32P]-2-azido-ADP/mol of F1. Under these conditions, only the beta subunit was photolabeled. Covalent binding of one photolabel per beta subunit was ascertained by electrophoretic separation of labeled and unlabeled beta subunits based on charge differences and by mapping studies showing one major radioactive peptide segment per photolabeled beta subunit.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Diphosphate↗
PubMed1985

Exploration of nucleotide binding sites in the mitochondrial membrane by 2-azido-[alpha-32P]ADP.

The ADP/ATP carrier of beef heart mitochondria is able to bind 2-azido-[alpha-32P]ADP in the dark with a Kd value of congruent to 8 microM. 2-Azido ADP is not transported and it inhibits ADP transport and ADP binding. Photoirradiation of beef heart mitochondria with 2-azido-[alpha-32P]ADP results mainly in photolabeling of the ADP/ATP carrier protein; photolabeling is prevented by carboxyatractyloside, a specific inhibitor of ADP/ATP transport. Upon photoirradiation of inside-out submitochondrial particles with 2-azido-[alpha-32P]ADP, both the ADP/ATP carrier and the beta subunit of the membrane-bound F1-ATPase are covalently labeled. The binding specificity of 2-azido-[alpha-32P]ADP for the beta subunit of F1-ATPase is ascertained by prevention of photolabeling of isolated F1 by preincubation with an excess of ADP.

Adenosine Diphosphate↗
PubMed1985

Prophylactic effect of intravenous tiapamil on methylergometrine-induced coronary artery spasm in patients with variant angina: randomized double-blind trial.

Tiapamil is a new calcium entry blocker. The ability of its intravenous form to prevent methylergometrine-induced coronary artery spasm was studied in 11 consecutive patients with angiographically documented vasospastic angina. The study was designed as a double-blind crossover trial of tiapamil vs placebo. Each patient received, in a randomized order, either tiapamil, as a 1.5 mg/kg intravenous bolus followed by a 50 micrograms/kg/min infusion lasting 3 hours, or a matched placebo. Immediately after the infusion, methylergometrine tests were performed with up to 0.4 mg of methylergometrine or until a positive ECG was recorded. Compared to the values obtained after placebo infusion, tiapamil significantly lowered systolic and diastolic blood pressure (respective pre- and posttiapamil values: 119.9 +/- 17.7 vs 142.1 +/- 25.5 mm Hg, p less than 0.01; and 72.0 +/- 9.1 vs 82.4 +/- 9.3 mm Hg, p less than 0.02); the drug exerted no significant effect on heart rate (63.9 +/- 13.3 vs 67.6 +/- 16.5 bpm, NS), PR interval (0.180 +/- 0.020 vs 0.177 +/- 0.017 sec NS), or QTc interval (404.4 +/- 16.5 vs 396.0 +/- 26.6 msec, NS). After placebo, 10 patients had positive methylergometrine tests following single doses ranging from 0.1 to 0.4 mg. The remaining patient developed ventricular bigeminy, which resolved immediately after administration of isosorbide dinitrate; his test was therefore considered negative in the evaluation of the results. In contrast, after tiapamil, eight patients had negative tests for doses of up to 0.4 mg methylergometrine, and three had positive tests for the same methylergometrine doses as after the placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Localization of the N-ethylmaleimide reactive cysteine in the beef heart mitochondrial ADP/ATP carrier protein.

Alkylation of the ADP/ATP carrier protein in beef heart mitochondria by N-ethylmaleimide (NEM) results in inactivation of transport. One out of the four cysteinyl residues contained in 1 mol of carrier subunit of Mr 32 000 is alkylated by NEM. The identification of the alkylated residue to Cys-56 has been achieved by chemical and enzymatic cleavages. The chemical cleavages included cleavages at the nonalkylated cysteinyl residues by cyanide at alkaline pH and at methionyl residues by cyanogen bromide. Enzymatic cleavage involved the use of trypsin and chymotrypsin; the resulting peptides were resolved by high-performance liquid chromatography. Analysis of a small size [14C]NEM-labeled peptide obtained by tryptic and chymotryptic digestion of the [14C]NEM-labeled carrier protein yielded the following amino acid sequence: (Formula: see text) where X is probably a substituted lysine.

Alkylation↗
PubMed1984

[Socioeconomic benefits of coronary dilatation].

The socioeconomic benefits of coronary artery dilatation to the individual and the society in general, were assessed in a review of our first 158 cases in which we studied the length of in-patient treatment, the period off work and the number of patients returning to work after six months and one year. The population included 114 men and 44 women with an average age of 50 +/- 10 years, a history of anginal pain of 18.10 +/- 26.13 months, and of resistant angina of 4.33 +/- 5.72 months. Only one artery was diseased in 130 patients (82%), the remaining patients having multivessel disease. Left ventricular function was normal in 76% of the patients under study. Fifteen patients had already finished working at the time of dilatation and were excluded from the study. One hundred and nineteen (84%) of the 142 patients followed-up were still working before dilatation and 112 (79%) returned to work after 6 months. Of the 94 patients with a good initial result of dilatation, 76 returned to work (81%); 12 initial failures were treated medically, and 6 (50%) returned to work (p less than 0.05); 36 initial failures underwent aorto-coronary bypass surgery and 30.83% are back at work. At one year, 89% of the 103 patients followed-up were working, whilst only 83% of this subgroup were working before dilatation. The 91% of the 69 initial successes have returned to work; 71% of the 7 failures treated medically and 95% of the 27 failures who then underwent bypass surgery, have also returned to work.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Synthesis and properties of fluorescent derivatives of atractyloside as potential probes of the mitochondrial ADP/ATP carrier protein.

The chemical synthesis of fluorescent derivatives of atractyloside (ATR), an inhibitor of the mitochondrial ADP/ATP carrier protein, is described. These derivatives are the following: 6'-O-dansyl ATR, 6'-O-dansyl-aminobutyryl ATR, and 6'-O-naphthoyl ATR. The spectral properties of these analogs were analyzed, and their biological features were compared to those of ATR. The fluorescence emission of the dansyl ATR derivatives was increased in organic solvents and that of naphthoyl ATR was decreased; for both analogs, solubilization in organic solvents resulted in a blue shift of the emission peak. The fluorescent dansyl and naphthoyl ATR derivatives were specifically recognized by the mitochondrial ADP/ATP carrier protein. Because of their spectral properties and their biochemical reactivities, the fluorescent analogs of ATR can be considered as potential probes to investigate the topography of the ADP/ATP carrier in the mitochondrial membrane and to monitor conformational changes of the ADP/ATP carrier protein associated with transport.

Adenosine Diphosphate↗
PubMed1983

[Rehabilitation and return to work of patients after aortocoronary bypass].

A pilot project with medical, physical and psychosocial evaluation and a physical and psychosocial rehabilitation program included 59 men, under age 60, inactive for less than one year and who underwent aortocoronary bypass surgery between november 1978 and march 1980. A control group of 60 comparable patients was studied by questionnaire one year after the operation. The percentage of return-to-work was not significatively different: respectively 92 p. 100 and 89 p. 100. A previous study on a similar population determined 9 predictive sociodemographic and medical factors: age, angina class, duration of symptoms, associated vascular disease, non cardiovascular illness, education, physical workload, length of preoperative unemployment, annual income. The evaluations of this study showed the importance of the psychosocial factors and alcoholism. In comparison with our previous studies, the increased percentage of return-to-work (from 69 p. 100 to 89 p. 100) is mostly due to a shorter preoperative period of inactivity; the percentage of patients operated on within three months of inactivity increased from 44 p. 100 to 74 p. 100 in the last ten years. In the group of patients with a good or excellent preoperative prognosis, 94 p. 100 were working after one year. We conclude that a strategy for improving return-to-work after surgery is to decrease the period of preoperative inactivity. By using nine objective predictive factors and a psychosocial evaluation, it is possible to screen patients with a poor return-to-work prognosis and to submit them to an individualized rehabilitation program.

Adult↗