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Biomedical subjects

J Bonnet

Publications and source records attributed to J Bonnet.

At least 127 records · Page 7Linked to original sources
PubMed1991

[Mitral valve prolapse and angina with normal coronary arteries: research of a thrombogenic factor].

The potential thrombotic risk of mitral valve prolapse may, in certain circumstances, require preventive treatment. This study was aimed at determining whether the presence of angina in patients with mitral valve prolapse and healthy coronary vessels was accompanied by a high-risk thrombogenic profile. Forty two patients (19 women and 23 men) with anginal chest pain and angiographically normal coronary vessels were divided into two populations according to the presence (18 patients) or absence (24 patients) of mitral valve prolapse (MVP) shown by angiography. Before angiography, all patients underwent laboratory studies to detect any possible abnormality of plasma coagulation and of prothrombotic physiological fibrinolysis. Study of subgroups, according to sex and/or the presence of MVP, revealed no significant difference in the profile of laboratory parameters. Thus the presence of angiographic MVP in symptomatic patients free of atherosclerosis is not associated with the existence of any particular thrombotic profile and, theoretically, does not require preventive anti-thrombotic treatment.

Angina Pectoris↗
PubMed1990

cDNA library construction from small amounts of unfractionated RNA: association of cDNA synthesis with polymerase chain reaction amplification.

We describe here a general and simple procedure for cDNA library construction making use of in vitro amplification of cDNA by polymerase chain reaction (PCR). The first-strand cDNA is synthesized from total RNA with a primer EcoRI-(dT)17 and oligo(dG) tailed. An oligonucleotide, EcoRI-BamHI-(dC)13, is used to prime the second-strand synthesis by the thermostable DNA polymerase of Thermus aquaticus. The double-stranded cDNA is then amplified directly by PCR. A study of the effect of the elongation time on the PCR products showed that a long extension time is necessary to overcome the size heterogeneity of the cDNA population. Starting from 1 microgram of total brain RNA, the products obtained ranged from 200 to more than 2000 bp. The presence of the myelin basic protein cDNA sequence was determined. A lambda gt10 library containing 2 x 10(6) clones was established with the amplified cDNA. No sequences originating from rRNA were detected by Southern blot analysis. The ability to produce representative cDNA libraries from minute amounts of total RNA by this protocol should have many applications to studies of gene expression in small amounts of tissues or cells.

Animals↗
PubMed1990

Risk factors for progression of atherosclerosis six months after balloon angioplasty of coronary stenosis.

To assess the possible progression of coronary artery disease after percutaneous transluminal coronary angioplasty (PTCA) and its relation to risk factors and restenosis, 124 patients who underwent a first successful PTCA were studied. All had routine follow-up angiography 5 to 8 months after PTCA. Restenosis was defined as a 30% decrease in diameter stenosis or a return to greater than 50% stenosis, and progression (in any nondilated site) as a 20% decrease in diameter stenosis, assessed by a video-densitometric computer-assisted technique. Univariate and multivariate analysis with respect to progression was carried out for age, sex, initial unstable angina, previous myocardial infarction, diabetes mellitus, hypertension, hypercholesterolemia (greater than or equal to 6.2 mmol), smoking habits, Jenkins' score, dilated artery and restenosis. Forty-one patients (33%) had restenosis, and 23 (19%) had evidence of progression; 20 (87%) of these latter patients had restenosis and 3 (13%) did not. Univariate correlates of progression were: previous myocardial infarction (p less than 0.05), higher Jenkins' score (p less than 0.0003) and restenosis (p less than 0.0001). Restenosis was the only multivariate correlate (p less than 0.00003). Progression at routine angiography after PTCA is not rare, and appears to be related to both the initial extent of coronary artery disease and restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1990

Abnormal cholesterol metabolism in imipramine-treated fibroblast cultures. Similarities with Niemann-Pick type C disease.

Addition of low-density lipoprotein (LDL) to cholesterol-deprived human skin fibroblast cultures treated by imipramine at a 20 microM concentration induced a significant intracellular accumulation of unesterified cholesterol. Intracytoplasmic inclusions were already visible by histochemical filipin staining after 2 h of LDL uptake and were progressively mobilized towards the perinuclear region within 24 h. At this concentration of the drug, the rate of proteolytic 125I-LDL hydrolysis was similar in treated and untreated cells. Treated cells maintained in lipoprotein-deficient medium showed no abnormality, indicating the exogenous origin of the accumulated sterol. Further, the drug induced a drastic dose-dependent impairment of LDL-stimulated cholesterol esterification, not related to an inhibition of acyl CoA:cholesterol acyltransferase, and a significant delay in down-regulation of de novo cholesterol synthesis. However, imipramine did not affect 25-hydroxycholesterol-mediated regulation of the two latter processes. These results resemble those observed in Niemann-Pick type C disease and suggest an impaired mobilization of LDL-derived cholesterol in imipramine-treated cells.

Acetates↗
PubMed1990

Cardioprotective effect of trimetazidine in severe ischemic cardiomyopathy.

The aim of this study was to assess the value of long-term treatment with 60 mg per day of trimetazidine, a cellular antiischemic agent, in comparison with placebo, in patients with ischemic cardiomyopathy controlled by conventional treatments. Twenty patients, with a mean age of 59.5 +/- 1.6 years, suffering from severe ischemic cardiomyopathy (NYHA IV, 6 patients; NYHA III, 14 patients) confirmed by coronary angiography, were included in the study; four of them suffered from residual angina. All of these patients were receiving long-term treatment with long-acting nitrates associated with digitalis (9 patients), diuretics (15 patients), anticoagulants (13 patients), and antiarrhythmics (11 patients), and were considered to be stabilized at the time of inclusion in the study. The examinations consisted of clinical and laboratory assessment, resting ECG, 24-hour ECG monitoring, X-ray evaluation of cardiac volume (CV), and evaluation of echocardiographic left ventricular shortening (ELVS) and of isotopic ejection fraction (EF). These three parameters were expressed as a percentage variation with respect to the initial value, and their variation between the two groups was compared by means of two-way analysis of variance. Clinically, the therapeutic benefit provided by trimetazidine resulted in: a) an improvement of dyspnea in all patients treated with trimetazicine compared with only one patient with placebo (p less than 0.001), b) resolution of residual angina, which was unchanged with placebo, c) reduced requirements for complementary treatments (a single case versus eight cases in the placebo group; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Dilated↗
PubMed1990

Tryptophanyl-tRNA synthetase-like immunoreactivity in the central nervous system and midgut of the migratory locust. Comparisons with gastrin-cholecystokinin-like and octopamine-like immunoreactivity.

A tryptophanyl-tRNA synthetase (TrpRS)-immunoreactivity is localized in various neurosecretory cells of all ganglia of the central nervous system of the Orthoptera Locusta migratoria, except in deutocerebrum, and in endocrine cells of the midgut. It has been observed that TrpRS-like material never co-localizes either with CCK-like or octopamine-like material. TrpRS immunoreactive perikarya and processes that ramify extensively throughout the neuropiles have been detected in the protocerebrum, optic lobes, tritocerebrum, suboesophageal, thoracic and abdominal ganglia. In the lateral protocerebrum, a particular TrpRS pathway different from the lateral gastrin cholecystokinin (CCK-8(s] pathway is revealed, certain of these processes terminating in the glandular part of the corpora cardiaca. In the metathoracic ganglion, have been observed numerous immunoreactive cell bodies and processes in the neuropiles. Some of them constitute a major pathway and which are distinct from octopamine (OA) cells but in close vicinity with the latter. In the midgut immunopositive TrpRS-like cells are dispersed among the regenerative and digestive cells of the epithelium; they are different from gastrin-cholecystokinin positive cells. The various TrpRS-like immunoreactivities identified in Locusta indicate that TrpRS-like material may occur in different tissues of organisms other than Vertebrates. These results suggest also that TrpRS-like enzyme could be involved in functions other than aminoacylation, as in Vertebrates.

Animals↗
PubMed1990

Therapeutic value of a cardioprotective agent in patients with severe ischaemic cardiomyopathy.

Trimetazidine (TMZ) has been shown to have anti-ischaemic properties improving exercise tolerance without haemodynamic effects. A 6-month double-blind placebo-controlled study was carried out in 20 patients, mean age 59 +/- 6 years, to examine the benefit of adding 60 mg of TMZ vs placebo to the classical therapy, excluding those previously treated with calcium-antagonists, conversion enzyme inhibitors, vasodilators and antiplatelet agents. All patients had severe ischaemic cardiomyopathy, confirmed by coronary angiography; six were in NYHA class IV; 14 in NYHA class III; four had mild recurrent angina pectoris. assessment included clinical and biological evaluation, electrocardiography (ECG), 24-h ECG monitoring, cardiac volume evaluation with chest X-ray, left ventricular fractional shortening by echocardiography, left ventricular ejection fraction by radionuclide angiography. Baseline characteristics were similar in placebo (11 patients) and TMZ (nine patients) groups. Eighteen patients (nine in each group) were followed up for 6 months. In eight patients of the placebo group, treatment had to be modified (addition of calcium antagonists: four patients, conversion enzyme inhibitors: two patients; digitalics: one patient; diuretics: one patient). In the TMZ group, digitalic therapy was withdrawn in one patient and added in one patient (P less than 0.01). At 6 months, all TMZ group patients were free from angina; dyspnoea was improved in all TMZ patients and in only one placebo patient (P less than 0.001). Ejection fraction, increased by 9.3% in the TMZ group and decreased by 15.6% in the placebo group (P less than 0.018), CV decreased by 7% with TMZ, increased by 4% with placebo. (P = 0.034).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1990

[Laitinen's stereo-adapter: application to the fractionated cerebral irradiation under stereotaxic conditions].

Radiosurgery is a technique which provides a single high dose of radiation very precisely to an intracranial lesion. The volume of tissue treated is small enough to avoid undue biological damage. This treatment requires very sophisticated apparatus and often considerable modifications in the treatment apparatus. The authors have closen to elaborate a system which makes it possible to deliver conventional fractionated irradiation, using a non-invasive stereotactic head frame called "Laitinen stereo-adapter". By fractionating the dose, most benign or low-grade malignant brain tumours can be treated, whatever their volume. The stereo-adapter and the target localization process are described. It can be used with C.T. scanning, angiography or M.R.I. The treatment apparatus is a linear accelerator delivering a 10 M.V. photon beam and treatment is made in the precise positioning of the target localization. The geometrical accuracy of the repeated mountings was studied in a preliminary study, showing a mean discrepancy of less than 1 mm in the three space planes. The geometrical accuracy of the radiation treatment was also studied on a phantom and the precision evaluated at less than 1 mm. The addition of extra collimators with a precollimation system decreased the lateral penumbra to 2-3 mm. Careful dosimetry was performed for each collimator. The use of non-coplanar arcs makes it possible to obtain a steep dose fall off outside the target volume. The dose planning calculations were compared to photodensitometry and thermoluminescent measurements, showing a good correlation. Each technical point will be discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗
PubMed1989

[Mortality of dilated myocardiopathies as a function of continuation of alcohol drinking. Multivariate analysis concerning 236 patients].

A retrospective study was conducted in 236 consecutive patients with dilated cardiomyopathy to determine the characteristics of the disease in heavy alcohol drinkers (n = 110) and to study its outcome, using a Cox model, according to whether the patients were abstainers (n = 49) or continued to indulge drinking (n = 61). At the time of diagnosis, pulmonary pressures were higher in heavy drinkers than in abstainers. During a mean follow-up period of 39 +/- 27 months, 80 patients died of heart disease, viz.: 46 out of 127 non-alcoholic patients (36.2 per cent), 31 out of 61 heavy drinkers (50.8 per cent) and 3 out of 49 patients who had given up alcohol (6.12 per cent). Thus, independently of other parameters, abstinence is a highly significant (P less than 0.001) factor of favourable prognosis in dilated cardiomyopathy.

Adult↗
PubMed1989

The role of dental canal fillings in the development of Aspergillus sinusitis. A report of 85 cases.

Radiopaque concretions in the maxillary sinus in cases of sinusitis are often observed in infections with aspergillosis. For several authors, such features are considered to be typical of these infections. For us this foreign body in most cases is believed to be related to overfilling of the teeth. We have previously drawn attention to this fact. We report 85 cases of aspergillosis of the maxillary sinus. Cases involving immunosuppressed patients were excluded because of very different clinical conditions. A radiopaque foreign body was seen in 94% of the cases. Of this group, 85% were believed to be related to overfilling of maxillary teeth with dental paste, particularly since evidence for endodontic treatment was found in the premolar/molar region. An image of intrasinus dental paste was demonstrated in 12% of the cases as a direct extension of filling paste from affected teeth. The nature of the dental paste is important because the zinc contained can stimulate the growth of Aspergillus fumigatus. In vitro studies in our laboratory also showed that the growth of A. fumigatus was stimulated with a low concentration of zinc.

Adolescent↗
PubMed1989

Specific amplification of a DNA sequence common to all Chlamydia trachomatis serovars using the polymerase chain reaction.

Enzymatic DNA amplification was applied to DNA and elementary bodies of C. trachomatis. Oligonucleotide primers were chosen in a sequence of a conserved domain of the major outer membrane protein to generate the amplification of a 129-base pair fragment. This sequence was amplified in the 15 serovars of C. trachomatis; however, serovar J gave a weaker signal than the others. The specificity was controlled by EcoRI restriction enzyme digestion and Southern analysis using an internal probe of the amplified sequence. No cross-reaction was shown with DNA of 11 other bacteria. Thus, enzymatic DNA amplification by the polymerase chain reaction appears to be a potential tool for the specific detection of C. trachomatis.

Base Sequence↗
PubMed1989

Risk factors for myocardial infarction during coronary artery bypass graft surgery.

Patients with a particular thrombotic profile may be at greater risk of myocardial infarction during coronary artery bypass graft surgery. The thrombotic profile of 50 patients admitted to hospital with stable angina pectoris was determined prior to haemodynamic investigation. ECG results and determination of cardiac enzymes showed that 12 patients had suffered a perioperative myocardial infarction. These patients had a higher mean atherosclerotic score (42.1 +/- 10.5 vs 32.9 +/- 13, P less than 0.02), a longer aortic cross clamp time (59 +/- 15.2 vs 45.7 +/- 16.3 min, P less than 0.05), lower serum levels of protein C (101.2 +/- 26 vs 124.7 +/- 31.4%, P less than 0.05) and tissue plasminogen activator (322 +/- 580 vs 2307 +/- 2830 IU ml-1, P less than 0.01). There were no differences between the two groups in Jenkin's coronary score, the number and type of grafts, ejection fraction, left ventricular end-diastolic pressure, lipid profile or levels of markers of platelet release. In addition to a more severe distal coronary atheroma and a longer aortic cross-clamp time, patients with impaired endothelial fibrinolytic activity appeared to be at greater risk of myocardial infarction during coronary artery bypass graft surgery.

Aged↗
PubMed1989

Developmental expression of the P0 glycoprotein and basic protein mRNAs in normal and trembler mutant mice.

Mice affected by the autosomal dominant Trembler mutation exhibit a severe hypomyelinization of the PNS. Previous biochemical studies have shown that the accumulation of the major PNS myelin proteins, P0 and myelin basic protein (MBP), is strongly diminished in Trembler sciatic nerves during postnatal development. We performed Northern blots which showed that the size of mRNA species for P0 and MBP in normal and mutant mice are indistinguishable. Densitometric analysis of Northern blots showed that, in normal mice, the proportion of P0 mRNA increases up to the 12th day, then decreases slowly. At day 40, the proportion is 60% of the maximal value. In the mutant, the proportion of P0 mRNA increases up to the 12th day and then decreases much faster than in the control. At days 12 and 40, the P0 mRNA proportion measured in Trembler sciatic nerves represents only 40% and 7%, respectively, of the proportion measured in control littermates. The MBP mRNA proportion in the normal mice increases up to the 16th day, and then decreases to attain 45% of the maximum level at day 40. In the Trembler mouse, there is a maximum level at day 12, representing 25% of the normal level, but the MBP mRNA is barely detectable at days 8 or 40. Thus, these data seem to indicate that in the Trembler sciatic nerves, the proportions of P0 and MBP mRNAs are too small to allow the synthesis of normal levels of the corresponding proteins.

Actins↗
PubMed1989

Detection of Mycoplasma pneumoniae by using the polymerase chain reaction.

The polymerase chain reaction (PCR) technique was used to detect Mycoplasma pneumoniae. A specific DNA sequence for M. pneumoniae was selected from a genomic library, and two oligonucleotides were chosen in this sequence to give an amplified fragment of 144 base pairs. We show that DNA from different M. pneumoniae strains can be detected by PCR, with DNA from other Mycoplasma species giving negative results. Analysis of biological samples (throat swabs) obtained from hamsters that were experimentally infected with M. pneumoniae showed that PCR was more sensitive and reliable than conventional culture techniques for the detection of M. pneumoniae. Initial experiments on artificially seeded human bronchoalveolar lavages showed that PCR can be used to detect 10(2) to 10(3) organisms.

Animals↗
PubMed1989

[von Willebrand's disease and coronary atherosclerosis. Apropos of 3 cases].

The von Willebrand factor (VWF) is a link in the platelet-vessel wall interaction which plays an essential role in the response of the vessel wall to an atherosclerosis-including aggression. However, can von Willebrand's disease really prevent the development of atherosclerosis? The authors report 3 cases of young men aged 36, 40 and 51 years with atherogenic risk factors and von Willebrand's disease (two mild and one severe form). The three patients developed both atherosclerotic lesions and thrombosis. This would suggest that VWF deficiency does not protect humans from atherosclerosis.

Adult↗
PubMed1989

[Value of trimetazidine in the long-term treatment of cardiomyopathies of ischemic origin].

The effect of a cellular anti-ischemic, trimetazidine (TMZ) in ischemic cardiomyopathies, was evaluated in a double-blind versus-placebo (P) trial, over a period of six months. 20 patients, mean age: 59.5 years, with advanced ischemic cardiomyopathy, demonstrated by left catheterization and coronary angiography, with a past history of myocardial infarction, received either 60 mg per day of TMZ (nine patients) or the placebo (eleven patients) in addition to a basic treatment of digitalis, diuretics and nitrated medications. A complete, clinical, biological and paraclinical evaluation, including chest X-ray, ultrasonography, isotopic ventriculography and 24 h-ECG, was performed upon inclusion in the study; and after three and six months of treatment. Two patients from the placebo group were not reevaluated at six months. The clinical condition, according to the NYHA classification, improved in all patients from the TMZ group, deteriorated in eight on nine patients from the placebo group (p less than 0.001). The isotopic stroke volume is preserved with TMZ, deteriorated with P. The cardiac volume decreases with TMZ, increasing with P. TMZ is beneficial clinically and functionally in advanced ischemic cardiomyopathies.

Analysis of Variance↗