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Biomedical subjects

P Louis

Publications and source records attributed to P Louis.

At least 73 records · Page 4Linked to original sources
PubMed1995

Impairment of diastolic function during short-term anthracycline chemotherapy.

OBJECTIVE: To assess the early changes in left ventricular diastolic and systolic function due to anthracycline treatment. DESIGN: A prospective study of cardiac function by radionuclide angiography in adults before and one month after the end of anthracycline treatment. PATIENTS: 60 patients without cardiac disease treated with chemotherapy containing anthracycline. METHODS: Cardiac function was assessed by radionuclide measurement throughout treatment. Ejection fraction, peak ejection rate, time to peak ejection rate, filling rate, and time to peak filling rate were measured before and after treatment. To normalise radionuclide measurements of the left ventricular diastolic function the ratio of the filling rate to the ejection fraction and the ratio of the filling rate to the peak ejection rate were calculated. RESULTS: No patient developed symptomatic congestive cardiac failure. The ejection fraction decreased from 58% (5%) to 55% (6%) (P < 0.001), the peak ejection rate fell from 2.99 (0.41) to 2.77 (0.41) of the end diastolic volume per second (P < 0.001), and the peak filling rate from 2.71 (0.47) to 2.55 (0.44) of the end diastolic volume per second (P < 0.01) after treatment. No difference was observed in the normalised ratios. CONCLUSIONS: This report shows simultaneous impairment of left ventricular systolic and diastolic radionuclide parameters. The absence of variation in normalised measurements suggests similar changes in ejection fraction, peak ejection rate, and peak filling rate throughout treatment.

Adult↗
PubMed1995

[Should a signal-averaged electrocardiogram be requested in the evaluation of malaise and syncope?].

In order to determine whether signal-averaged electrocardiography was useful in the diagnosis of syncopal ventricular tachycardia, 244 subjects with malaise or unexplained syncope without documented ventricular tachycardia underwent endocavitary electrophysiological study and signal-averaged electrocardiography with a 25 Hz bandpass filter. Ninety-three patients had no apparent cardiac disease whereas 151 patients had cardiac problems. ventricular tachycardia was induced in 91 patients. Fifty-two of them (57%) had ventricular late potentials. Twenty-two patients without inducible ventricular tachycardia also had late potentials (14%). The diagnostic value of signal-averaged electrocardiography depended on the cardiac disease: in the absence of cardiac disease, its sensitivity was poor (31%) but the specificity was excellent (96%). In the presence of cardiac disease, the sensitivity improved (63%) but the specificity was not as good (67%). The lack of sensitivity in the group with cardiac disease generally concerned subjects with inducible rapid ventricular tachycardia. The authors conclude that signal-averaged electrocardiography should not be requested in the investigation of unexplained syncope in subjects without cardiac disease to demonstrate abnormal ventricular excitability which is very rate in these subjects. On the other hand it is more valuable in those with underlying cardiac disease although inducible rapid ventricular tachycardia may still escape detection.

Adolescent↗
PubMed1995

[Stenoses of the supra-aortic trunks associated with aortic supravalvular stenosis in a 3-year-old girl. Long-term surgical result].

Supravalvular aortic stenosis may be associated with arterial lesions. This condition is rare and its natural history is not well known. The authors report the case of a child operated in 1981 for supravalvular aortic stenosis and stenoses of the supraaortic vessels. The operation consisted of enlarging the ascending aorta with a patch and resection-reimplantation of both carotids without interposition of prosthetic material. Twelve years later, the haemodynamic result was the same as that of the postoperative control. This case tends to prove the low evolutive potential of this condition and the long term benefits of this surgical technique.

Aorta↗
PubMed1994

Differential transcriptional activities of HLA-DR genes in the various haplotypes.

The regulation of HLA class II genes is of particular interest with regard to the modulation of the immune response. The polymorphism of their coding regions is directly involved in the specificity of the Ag presentation, and their level of expression affects the extent of T cell activation. Previously, we have described an allelic polymorphism in the proximal promoter regions of HLA-DRB genes. The aim of this study was to compare the transcriptional activities of the promoters of the DRB genes and DRB1 alleles in a transient expression system. We have demonstrated a marked difference in their promoter strengths, as determined by their relative abilities to initiate transcription of the chloramphenicol acetyltransferase reporter gene in human B cell lines. The polymorphism of the promoter regions has been mapped to the regulatory boxes, and, by using gel retardation experiments, we found a differential ability of the nuclear proteins to bind to the partially conserved X box regions. Taken together, our results demonstrate the functional consequences of the allelic polymorphism of the proximal promoter regions of the DRB genes. These findings strongly suggest the existence, for the HLA-DR genes, of an interdependence between the polymorphism of the coding regions, which directly affects the capacity of peptide binding, and the polymorphism of the regulatory regions, which influences the transcriptional activities of the promoters.

Base Sequence↗
PubMed1994

Self-treatment of acute migraine with subcutaneous sumatriptan using an auto-injector device: comparison with customary treatment in an open, longitudinal study.

In a multicenter open longitudinal clinical trial where 479 patients suffering from migraine with or without aura were recruited, patients treated at home one to three migraine attacks with their customary treatment, and subsequently, over a 3-month period, one to three migraine attacks with 6 mg sumatriptan sc using an autoinjector. The headache response to customary treatment was 19% at 1 h and 30.5% at 2 h, and was not significantly different when only attacks treated "adequately" according to accepted treatment recommendations were considered: 16% at 1 h and 35% at 2 h. In contrast, 69% and 82% of patients treated with 6 mg sumatriptan sc had mild headache or no headache at 1 and 2 h respectively, regardless of migraine type or duration of symptoms prior to treatment. Other migraine symptoms (nausea, vomiting, photo- and phonophobia) were effectively treated with sumatriptan. Recurrence of migraine was observed in 31% of patients and was well controlled by a second injection of sumatriptan. It is concluded that 6 mg sumatriptan sc, self-administered using an autoinjector, is well tolerated and more effective than most currently used acute treatments for migraine in a population of severely affected patients consulting a neurologist.

Acute Disease↗
PubMed1994

[Effect of rehabilitation after myocardial infarction on muscular metabolism. Contribution of phosphorus 31 NMR spectroscopy].

P 31 NMR spectroscopy is a recent technique which allows a non-invasive and direct analysis of oxidative metabolism and pH changes, an indicator of acidosis due to lactic acid accumulation in the skeletal muscles. The authors investigated oxidative muscular metabolism of the sural triceps in 10 patients after myocardial infarction by performing a study after the acute phase and repeating the study after a programme of physical training. At rest, there were no significant differences. On the other hand, for the same level of maximal effort, the depletion in phosphocreatinine (PCr) and the accumulation of inorganic phosphate (Pi) were significantly lower after physical training: the PCr/PCr + Pi increased from 0.467 +/- 0.179 to 0.538 +/- 0.20 (p < 0.02) and the Pi/PCr ratio decreased from 1.570 +/- 1.440 to 1.181 +/- 1.069 (p < 0.05). The pH at the same level of maximal exercise did not change significantly between the two periods: 6.85 +/- 0.16 vs 6.88 +/- 0.15 (NS). The peak oxygen consumption (VO2) measured during bicycle ergometry increased significantly from 23.4 +/- 10.5 to 28.3 +/- 12.14 ml/min/kg after exercise training (p < 0.01). In addition, a correlation was observed between the improvement of the peripheral parameters (PCr/PCr + Pi) and the increase in VO2 max (r = 0.757, p < 0.01). The authors results confirm the effects of physical training on oxidative metabolisms of the peripheral muscles and its influence on improvement of global performance of coronary patients.

Adult↗
PubMed1994

[Changes in heart rate after ventricular stimulation; correlations with vagal tone].

The authors report a new method of studying the autonomic nervous system, especially vagal tone, during endocavitary electrophysiological studies. After termination of fixed ventricular pacing at incremental rates to 200/min, an initial acceleration of the heart rate is observed followed about 5 seconds later by a sudden slowing. This phenomenon was studied in 278 patients. Ninety seven patients had no cardiac disease: the variation in heart rate was 33 +/- 18%. In the 181 other patients with cardiac disease (ejection fraction 35 +/- 16%) the variation was only 21 +/- 16% (p < 0.01). When the ejection fraction was less than 30%, the variation was only 13 +/- 4%. When the heart rate variation was less than 10%, the prognosis was poor because, of the 48 patients with this sign, 13 died, whereas there were only 2 deaths in the 133 other patients with cardiac disease and preserved adaptation. In 14 patients without cardiac disease the injection of 2 mg of atropine suppressed all adaptation of the heart rate, whilst in 18 other patients, oral betablockers reduced the variation but it persisted to a significant degree. The authors conclude that the adaptation of the heart rate after rapid ventricular stimulation is probably a reflection of vagal tone and may be used to assess the prognosis of subjects undergoing electrophysiological investigations.

Adolescent↗
PubMed1994

[Valvuloplasty of a tricuspid bioprosthesis by the Inoue's technique].

The authors report the case of a patient who had undergone tricuspid valve replacement with a bioprosthesis in 1985 after infectious endocarditis complicated by paradoxical embolism. The appearance of signs of right heart failure eight years later led to the diagnosis of stenotic degeneration of the bioprosthesis. Inoue balloon valvuloplasty was performed with no complications leading to significant improvement in the patient's condition.

Adult↗
PubMed1994

Differential expression of HLA-DRB genes according to the polymorphism of their regulatory region.

The polymorphism of the HLA-class II molecules is directly involved in the specificity of the antigen presentation. We have previously described an allelic polymorphism in the proximal promoter region of the HLA-DRB genes. In this study, we demonstrate that this polymorphism has functional consequences on the transcriptional activity of the promoter of the different DRB genes. Indeed, transiently transfected DRB gene promoters into human B cell lines showed a marked difference in their ability to induce transcription of the chloramphenicol acetyl transferase (CAT) reporter gene. These findings suggest the presence of two interdependent effects of the HLA-class II molecules on the specificity of the immune response: one corresponding to the allelic polymorphism of the peptide-binding site and the second resulting from the polymorphism of the promoter regions inducing a variable expression of the DRB genes.

DNA↗
PubMed1994

[Lipomatous septal hypertrophy. Apropos of 3 cases].

Lipomatous hypertrophy of the inter-atrial septum is characterised by fatty accumulation in the inter-atrial septum. Long unrecognised, it has been discovered anew by virtue of the use of transesophageal echocardiography. The authors report three cases, including one presenting as acute ischemia of the right lower limb. After studying the contribution of imaging techniques to its diagnosis, the authors consider the principal differential diagnoses of this condition.

Aged↗
PubMed1994

[Uncommon cardiac manifestations disclosing pheochromocytoma. Apropos of 3 cases].

The diagnosis of pheochromocytoma is usually considered in the presence of permanent hypertension with exacerbations. However, pheochromocytoma may be responsible for a varied range of adrenergic symptomatology and hemodynamic equilibrium may be threatened by the spontaneous or induced massive release of pressor amines. Three cases form the basis of a description of unusual situations: acute pulmonary edema, acute circulatory failure and myocardial infarction with normal coronary vessels. The divercity and severity of these clinical situations are such that the possibility should always be suspected when confronted by any cardiomyopathy without obvious etiology, in particular in a hypertensive patient. The only treatment remains ablation of the tumour and diagnosis as an emergency is based, apart from history, on ultrasonography and/or abdominal CT scan and assay of urinary catecholamine derivative levels, which can be obtained within a few hours.

Adrenal Gland Neoplasms↗
PubMed1993

Polymorphism in the regulatory region of HLA-DRB genes correlating with haplotype evolution.

Class II genes of the human major histocompatibility complex (MHC) are polymorphic. Allelic variation of the coding region of these genes is involved in the antigen presentation and is associated with susceptibility to certain autoimmune diseases. The DR region is unique among human class II regions in that multiple DRB genes are expressed. Differential expression of the different DRB loci has been demonstrated, and we sequenced the proximal promoter region of the HLA-DRB genes, known to be involved in the regulation of these genes. We found locus-specific and allele-specific nucleotide variations in their regulatory regions and we determined the relationship between the regulatory regions of HLA-DRB genes. This polymorphism found in the regulatory conserved boxes could be involved in the observed differential expression of DRB loci. In addition, we found a polymorphism between the regulatory regions of DRB1 alleles which might be involved in an allele-specific regulation and therefore could be considered as an additional factor in susceptibility to autoimmune diseases.

Base Sequence↗
PubMed1993

Benign intracranial hypertension as a cause of transient partial pituitary deficiency.

A male patient is reported with benign intracranial hypertension, who presented with three periods of partial pituitary deficiency, corresponding to episodes of headaches and papilledema. No radiological signs of the empty sella syndrome were observed. Since benign intracranial hypertension has been implicated in the development of the empty sella syndrome, it is postulated that the endocrine deficiency syndrome encountered in the empty sella syndrome can be provoked by chronic intracranial hypertension in itself and is not necessarily secondary to the anatomical changes occurring in the sellar region.

Adult↗
PubMed1993

[Results of systematic programmed ventricular stimulation after myocardial infarction. Which protocol should be recommended?].

The authors report the prognostic value of ventricular arrhythmias induced by routine programmed ventricular stimulation after the acute phase of myocardial infarction. The protocol consisted of two extrastimuli in the first 185 patients and 3 extrastimuli in 308 patients. The use of 3 extrastimuli increased the incidence of inducible sustained monomorphic ventricular tachycardia (VT) < 270/mn, from 17 to 22% and, more importantly, that of ventricular fibrillation from 4 to 17%. Induction of ventricular flutter (monomorphic VT > 270/mn) was not increased. A long follow-up period (average 4 +/- 2 years) showed that the risk of VT was increased during the first months after infarction (n = 14), and that, 4 years later, other patients develop VT (n = 6). The risk of serious arrhythmias (VT and sudden death) was significantly higher in patients with inducible VT < 270/mn (20%) than in patients without inducible VT, but it was also higher in patients with inducible ventricular flutter (12.5%). The use of a third extrastimulus has a low positive predictive value for arrhythmic events (10%). This study confirms that the induction of sustained monomorphic VT after myocardial infarction is associated with an increased risk of arrhythmic events but the positive predictive value is relatively low (17%). In view of the risk of inducing non-specific ventricular fibrillation, the authors recommended using a stimulation protocol with only 2 ventricular extrastimuli.

Arrhythmias, Cardiac↗
PubMed1993

[Results of high amplification electrocardiogram in primary dilated cardiomyopathy].

Idiopathic dilated cardiomyopathy carries a high risk of sudden death. It is also associated with sustained ventricular tachycardia. A complex ventricular arrhythmia is recorded in 3/4 of cases on Holter monitoring which has a low specificity. The aim of the study was to determine whether signal-averaged electrocardiography could provide a better evaluation of the prognosis of this condition. The results of signal-averaged electrocardiography were compared with those of 24 hour Holter monitoring and of systematic programmed ventricular stimulation in 58 patients with idiopathic dilated cardiomyopathy. Late ventricular potentials were recorded in 13 of the 14 subjects with inducible and usually spontaneous sustained ventricular tachycardia. The sensitivity of the technique for evaluating the risk of sustained VT was therefore good (93%). Late potentials were also recorded in 9 patients with induced ventricular flutter or fibrillation, these patients being symptomatic (dizzy spells). Late potentials were also demonstrated in 14 of the 35 asymptomatic patients without inducible VT, indicating that this non-invasive investigation had a limited specificity (60%). In addition, during follow-up of the patients, the risk of sudden death was difficult to demonstrate. Late potentials were only found in subjects with inducible sustained VT but no in the other cases. In conclusion, signal-averaged electrocardiography seems to be valuable for evaluating the risk of sustained VT in subjects with idiopathic dilated cardiomyopathy and complex ventricular arrhythmias. The detection of the risk of sudden death is probably impossible by this technique.

Adult↗
PubMed1993

[Cardiac arrest reversed: causes and treatments].

The aim of this study was to report the probable mechanism of resuscitated cardiac arrest without acute myocardial infarction. Fifty-seven cases were recensed but the arrest was only documented in 44 subjects. Systematic non-invasive investigations and programmed stimulation showed that the diagnosis of cardiac arrest was probably false in 5 patients and, in the others, that a ventricular arrhythmia was probably the cause (63%). The occurrence of cardiac arrest under antiarrhythmic therapy may reveal an underlying abnormality requiring specific therapy (3/8). The absence of cardiac disease did not exclude the risk of VF (3 cases). When reproducible, ventricular arrhythmias were present during programmed stimulation, the prognosis was good if the arrhythmia could not be induced under antiarrhythmic therapy. It was easier to find an effective treatment for inducible ventricular fibrillation-flutter (13/17) than for inducible ventricular tachycardia (7/17). The prognosis was poor if the arrhythmia was unchanged during programmed stimulation under antiarrhythmic therapy and non-pharmacological treatment was required.

Adolescent↗
PubMed1993

[Value of the methylergometrin maleate test in recurrent cardio-circulatory arrests].

A 56-year-old man, with no particular past history, sustained two cardio-circulatory arrests preceded by constrictive chest pain. Coronary arteriography was normal during etiological investigations. The methylergometrine maleate (Méthergin (tm)) test enabled the diagnosis of severe spastic angina and guided appropriate management of this patient.

Angina Pectoris, Variant↗