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Biomedical subjects

J Marco

Publications and source records attributed to J Marco.

At least 181 records · Page 10Linked to original sources

[Long-term effects of transluminal coronary angioplasty. French multicenter study].

Although transluminal coronary angioplasty is now acknowledged as an effective treatment for coronary artery disease, the long-term outcome of patients treated by this method is still under evaluation. A french multicenter trial was set up and the long-term efficacy of transluminal coronary angioplasty was assessed in 546 patients undergoing the procedure before the 31/3/83. 380 initial successes (69 p. 100) were followed up for a period ranging from 6 to 48 months (average 19.9 +/- 10.4 months). A control coronary angiography was carried out in 88 p. 100 of cases. Restenosis (loss of over 50 p. 100 of initial angiographic improvement) was observed in 27 p. 100 of cases. Including the repeat procedures, the patency rate of the dilated vessels was 82 p. 100. Progression of atherosclerosis on another coronary artery was observed in 1.3 p. 100 of cases. After transluminal coronary angioplasty, 72 p. 100 of patients remained improved, 11 p. 100 underwent repeat angioplasty, 8 p. 100 underwent coronary bypass surgery, 1.3 p. 100 suffered myocardial infarction and 1.3 p. 100 died. Restenosis was associated with recurrence of angina pectoris in 90 p. 100 of cases (within 3.3 +/- 1.6 months) and a positive exercise stress test in 87 p. 100 of cases. Recurrence of angina due to progression of disease on the dilated vessel was observed in 24.2 p. 100 of cases; repeat transluminal coronary angioplasty was carried out for this indication in 38 p. 100 of cases, coronary bypass in 34.8 p. 100 and medical treatment was continued in 27.2 p. 100 of cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗

[Complications of transluminal coronary angioplasty. A multicenter French study (1983)].

The authors report the complications observed during 1 247 transluminal coronary angioplasties (TCA) performed in 1 187 patients in 17 french centers between 1979 and October 1983. There were 855 primary successes (68.9 p. 100). There were 41 cases of symptomatic dissection (3.3 p. 100) of which 32 underwent aortocoronary bypass surgery with a residual myocardial infarction (MI) in 13 cases (40.6 p. 100). Medical treatment of symptomatic dissection gave very poor results (7 out of 9 MI) and is formally contra-indicated. 67 per- or postoperative occlusions were observed (5.3 p. 100). This is the most serious complication which necessitates an emergency revascularisation procedure (TCA or coronary bypass surgery--CBS--) because MI rapidly follows in patients without a well-developed collateral circulation. In this series MI occurred in 28 out of 45 patients--62 p. 100--despite CBS. This underlines the value of an immediate repeat TCA which, when successful, results in a much faster revascularisation. Seventy-three MI (5.8 p. 100) were observed in the first 24 hours: 50 p. 100 were secondary to an angiographically documented coronary occlusion. The other two causes were coronary dissection and spasm. Emergency CBS was carried out in 107 cases (8.9 p. 100) mainly for coronary occlusion or symptomatic dissection. The mortality was 11 out of 1 187 patients (0.93 p. 100). Death occurred in the catheter laboratory in 3 cases, during the first 24 hours in the operating theatre in 1 case, and after the first 24 hours but before hospital discharge in 7 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗

[Disobliteration of coronary arteries by the laser. Peroperative experience].

The authors report their experience of coronary artery disobliteration by laser in 10 patients. This was a preliminary study to assess the effects of an Argon laser on atheromatous coronary stenosis in vivo. This technique was used during coronary bypass surgery. Two series of patients were treated: an initial group of 5 patients who underwent laser therapy associated with coronary bypass surgery; a second group undergoing laser therapy alone without distal bypass grafting. The results were assessed by immediate angiography in the first series and by the passage of calibrated probes in both series. Secondary control angiography after 3 weeks was carried out in all patients. The immediate results showed a constant improvement (less than 25%) in the degree of stenosis. However, secondary angiography showed secondary occlusion in 88% of cases. These preliminary results show: the immediate efficacy of Argon laser in reducing the size of atheromatous plaques, the innocuity of the method as there were no postoperative deaths, a high incidence of secondary failure which could be related to the type of indication (competitive flow in the first group and poor distal run off in the second group of patients) or to the type of laser used. The authors consider this to be a promising technique but a lot of clinical and experimental work remains to be done before it can be adopted for routine use.

Aged↗

Exercise-induced platelet activation in myocardial infarction survivors with normal coronary arteriogram.

Platelet activation may participate in the pathophysiology of myocardial infarction occurring in patients with normal coronary arteriogram. We investigated this possibility in a series of 9 such patients (group A) during a standardized bicycle exercise test as myocardial infarction had occurred in all of them during or soon after strong physical exercise. Twelve patients with effort-induced angina and coronary atherosclerosis (group B) and eleven healthy subjects (group C) served as test groups. Peripheral venous blood was collected by separate venipuncture before, at peak exercise and during recovery. As a sensitive index of activation, the shape of the circulating platelets was examined with a phase contrast microscope after instantaneous fixation of the whole blood. The percentage of non strictly disc-shaped platelets with one or more thin pseudopods was determined. Simultaneously, the plasma levels of platelet factor 4 (PF4) and of beta-thromboglobulin (beta-TG) were measured. At rest, there was no significant difference in the platelet morphology nor in the plasma levels of platelet specific proteins between the three groups. During exercise, a significant change in platelet shape occurred in group A and B patients and not in the healthy subjects. This platelet activation was not related to myocardial ischemia since it occurred to a similar extent in group B patients who developed electrocardiographic changes and in group A patients who did not. There was no detectable release of platelet proteins during exercise in any group.

Adult↗

Human coronary laser recanalization.

Five patients undergoing distal saphenous vein bypass had an attempt at intraoperative laser vaporization of a proximal coronary stenosis. Laser treatment of three patients was technically successful. One patient's successfully treated native vessel was competing with the graft at angiographic restudy 25 days after the procedure. This first human intraoperative laser recanalization trial generated questions regarding the energy source, power parameters, and catheter modifications required for satisfactory clinical laser therapy. The trial is directing future experiments toward more efficient and complete laser vaporization of atherosclerotic plaques in the human coronary vasculature.

Aged↗

Effect of ethanol in preovulatory periods on brain monoamine levels.

The effects of two doses of ethanol (2 and 4 g/kg, i.p.) on the concentration of catecholamines (noradrenaline and dopamine), serotonin and 5-hydroxyindoleacetic acid in various regions of the rat brain were studied. The ethanol administration of both doses induces a significant decrease in the levels of hypothalamic noradrenaline. Similarly, 5-hydroxyindoleacetic acid levels in the same region and hemispheres are increased. The high dose produces an elevation in the concentration of midbrain dopamine. It was concluded that the hypothalamus is the brain region most sensitive to the action of ethanol and the effect of this substance differs according to the brain area.

Animals↗

[Predictive value of plasma apolipoprotein B in myocardial infarction in young subjects. Correlations with coronarographic data].

In recent epidemiological studies, apolipoprotein-B (apo B), the main low density lipoprotein (LDL), was found to be significantly elevated in patients with early atherosclerosis. The aim of this study was to compare plasma apo B in a population of men who had suffered myocardial infarction before 45 years of age (N = 31) with a control population (N = 22). In the coronary group, there were 27 angiographies between the end of the first and third month. The plasma lipoproteins were separated by ultracentrifugation, cholesterol and triglycerides measured by enzymatic methods and apo B by Laurell's technique of immunoelectrophoresis. Our results showed significantly higher apo B in the coronary group (p less than 0.05). Serum cholesterol, triglycerides, very low density lipoprotein (VLDL) and LDL cholesterol were also significantly higher whilst high density lipoprotein (HDL) cholesterol was significantly lower. In addition, apo B levels correlated with the severity of the coronary lesions on angiography. Therefore, the plasma apo B level is a good predictive indicator of the presence of early coronary atherosclerosis and its severity.

Adult↗

[Systemic fibrinolytic treatment in the acute phase of myocardial infarction. Effects on coronary repermeation and left ventricular function].

Coronary angiography and 2D echocardiography were performed at the 24th hour and 21st day of acute myocardial infarction in 18 patients to study the effects of peripheral fibrinolytic therapy on coronary repermeabilisation and left ventricular function. The treatment was the same for all patients included in the study. The left ventricular ejection fraction and sequential left ventricular contractility were analysed. The first coronary angiographic control study (24th hour) showed coronary repermeabilisation in 18 cases, occurring in significantly stenosed vessels in 15 cases and in angiographically normal vessels in 3 cases, demonstrating appearances of thrombosis. Transluminal coronary angioplasty was performed in 8 cases. Coronary angiography at the 21st day showed 4 secondary occlusions in patients who had not undergone angioplasty. The comparative study of left ventricular function did not show a statistically significant difference between the 24th hour and the 21st day studies. Biochemical studies showed on early massive elevation of the specific myocardial enzyme CPK MB and a rapid fall in the fibrinolytic activity of all patients. The treatment was well tolerated and mortality was nil.

Adult↗

Stimulatory effect of the intestinal peptide PHI on glycogenolysis and gluconeogenesis in isolated rat hepatocytes.

The newly isolated peptide PHI provoked a dose-dependent stimulation of glycogenolysis and gluconeogenesis in isolated rat hepatocytes; at 1 microM-PHI, both processes were increased 1.6-fold as compared with basal values. These PHI-mediated effects were accompanied by the activation of glycogen phosphorylase and the inactivation of pyruvate kinase. PHI (1 microM) also caused a 2-fold increase in hepatocyte cyclic AMP.

Animals↗

Suppressor effect of morphine on the pancreatic polypeptide response to insulin-induced hypoglycemia in man.

The effect of intravenous infusions of morphine and naloxone, alone or in combination, on basal plasma pancreatic polypeptide (PP) levels as well as on the PP response to insulin-induced hypoglycemia in normal subjects was investigated. Morphine infusion (150 micrograms/kg/120 min, intravenously) induced a progressive decrease in the basal plasma PP levels (basal value: 158 +/- 42 pg/mL; nadir, at 120 minutes: 108 +/- 26 pg/mL; P less than 0.05). In control experiments, insulin injection was followed by a 10-fold plasma PP elevation (peak: 1258 +/- 71 pg/mL). During morphine infusion, the PP response to hypoglycemia appeared consistently reduced (peak: 404 +/- 117 pg/mL, P less than 0.05 vs. control). Naloxone pretreatment (4.8 mg, intravenously) partially reversed the blocking effect of morphine on the PP secretion evoked by insulin-induced hypoglycemia (peak: 977 +/- 133 pg/mL, P less than 0.05 vs. control and morphine experiments). Similar degrees of hypoglycemia were achieved with and without morphine or naloxone. The intravenous infusion of naloxone alone failed to significantly modify both basal circulating PP levels and the PP response to hypoglycemia. The observation that morphine reduces PP output, both the basal value and that elicited by a parenteral stimulus, indicates that this effect is independent of its action on the gastrointestinal tract. On the other hand, the lack of effect of naloxone alone on PP secretion argues against the participation of endogenous opiates in the control of this process.

Adult↗