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Biomedical subjects

A Amiel

Publications and source records attributed to A Amiel.

108 records · Page 6Linked to original sources
PubMed1987

[Ambulatory blood pressure profiles of patients with permanent or occasional hypertension. Correlation with clinical data].

Ambulatory blood pressure (BP) recording was performed in 57 untreated hypertensive patients by means of the "Spacelabs" non-invasive apparatus. Patients were divided into two groups according to BP measurements previously made during medical consultation. Group I comprised 25 "permanently hypertensive" patients (diastolic BP always above 95 mmHg) and group II, 32 "occasionally hypertensive" patients (diastolic BP sometimes normal, sometimes above 95 mmHg). The same circadian rhythm was observed in both groups. The mean ambulatory BP level was significantly higher (p less than 0.001) in group I patients than in group II patients, either over the whole of the 24-hour period (142.0/88.0 versus 122.7/75.3 mmHg), or in day time (149.0/92.5 versus 128.2/78.9 mmHg) or at night (128.0/80.1 versus 111.5/68.0 mmHg). In contrast, there did not seem to be any significant difference between the two groups in relative long-term variability of BP, expressed as the standard deviation/mean BP values ratio. Comparison with clinical data showed that BP values measured during consultation (160/103 mmHg in group I, 143/94 mmHg in group II) were higher than ambulatory values and, chiefly, that there was very poor correlation between the two measurement methods, precluding any extrapolation. Automatic ambulatory BP recording provides for more accurate evaluation of hypertensive patients, enabling emotional "artefacts" to be excluded and patients "reactivity" to their socio-professional environment to be assessed. However, in the absence of sufficient epidemiological data, doctors should not feel authorized to base their therapeutic decisions on the sole data supplied by ambulatory BP recordings.

Adult↗
PubMed1986

[Comparison between amiodarone and disopyramide in the treatment of ventricular extrasystoles].

The authors have compared the anti-arrhythmic activity and tolerance of disopyramide and amiodarone in the treatment of ventricular extrasystoles (VES) by using two quantitative methods of assessment. The stability of the rhythmic disorder was confirmed by two control Holter recordings in 20 patients without treatment, 16 of whom were bearers of an organic cardiopathy. The ventricular extrasystole was greater than 90 VES/hour in 18 patients. After the first control, Holter recording, each patient was treated successively with 400 mg of disopyramide/day in 4 doses for average period of 31 days, then a second Holter control recording without treatment, then 600 mg/day of amiodarone for 8 days followed by a maintenance dose varying from 200 to 400 mg/day: this second period of treatment lasted for an average of 38 days. The reduction of the number of VES was greater than 65 percent (SAMI criterion) in 2 of the 20 patients treated with disopyramide and in 13 of the 20 patients treated with amiodarone. Using the method of variance analysis, disopyramide was found to be efficacious in 5 cases out of 20 and amiodarone in 15 cases out of 20. Both methods indicate that the greater efficacy of amiodarone is statistically significant (p less than 0.01). All of those who did not respond to amiodarone were also non-responders to disopyramide.

Adult↗
PubMed1986

[Thrombus of the left auricle: a rarely noticed cause of systemic embolism. Apropos of an echocardiographic case report].

The authors report the case of a 70 year old woman who had 3 episodes of acute ischaemia of the lower limbs in the space of 2 months. She was admitted to the Cardiology Unit after the second embolism: successive ECG recordings showed signs of the sick sinus syndrome justifying permanent pacing and anti-arrhythmic and anticoagulant therapy. The standard 2D echocardiographic views showed no signs of intracardiac disease, but a modified high short axis view demonstrated an oblong thrombus in the left auricle. Unfortunately, therapeutic non-compliance led to a third episode of embolism 2 weeks later; a repeat 2D echocardiogram showed the left auricle to be completely free of thrombosis. The authors review the medical literature of this condition. Echocardiography only began to play a useful diagnostic role from 1984 when technical improvements and the use of new and more appropriate views of the left auricle were introduced.

Aged↗
PubMed1986

[Aneurysms of the interauricular septum. Review of the literature apropos of 8 cases].

The authors present 8 cases of aneurysms of the interauricular septum (AIAS). The diagnosis was established in all cases by two-dimensional echocardiography (E2D) which was requested, three times following a cerebral vascular accident (CVA). The AIAS manifest themselves as localised "hernias" of the inter-auricular septum, mobile during the cardiac cycle. Their topography was strictly right inter-auricular in 6 cases, whereas in the other 2 patients the AIAS passed into the left atrium at protosystole and returned to the right atrium at telesystole. Catheterization with angiography was carried out 5 times: the inter-auricular septum was crossed 4 times without gasometric reasons for an associated shunt; the AIAS was opacified in all cases. An anti-coagulant treatment was prescribed for 3 patients who had suffered a CVA, and for a fourth presenting numerous supraventricular extrasystoles which were sometimes grouped. A review of the literature of the last fifty years enabled a compilation of 93 cases of AIAS to be made, 49 of which had been examined by E2D, 35 had had a hemodynamic and angiographic exploration and 47 an anatomical and/or surgical confirmation. The main results obtained are described and commented on. The diagnostic, etiopathological and prognostic problems raised by the "updating" of this pathology are discussed.

Adolescent↗
PubMed1986

[Increase in the amplitude of R waves in exertion: a bad diagnostic criterion for coronary insufficiency].

91 symptomatic patients were given an exercise test on a bicycle ergometer and a coronary arteriography test within a delay of 31 days. Of the patients (13 females and 78 males), 35 presented with a normal coronary arteriography and 56 presented with a pathological coronary arteriography (16 of whom had a history of myocardial infarction). We have studied the diagnostic value of several parameters taking into account changes in R waves upon exercise in V4 V5 V6 and changes in S waves in V1 V2. The most reliable parameter is also the easiest to calculate: it is considered positive when the R wave measured in V5 increases or does not change in the minute following cessation of exercise, as compared with the reference trace; it is considered negative when the R wave decreases. This criterion has a specificity of 60 per cent and a sensitivity of 71.4 per cent, and its diagnostic value is not improved by exclusion of patients with a history of infarction, or by exclusion of treated subjects or females. The horizontal or downsloping depression of the ST-segment has the same sensitivity but a better specificity (74%). Literature data are contradictory: some authors report that changes in the R wave upon exercise have a better predictive value than changes in the ST-segment, whereas an equal number of authors consider that the ST-segment is more informative. These differences of opinion result from methodological disparities and the large number of physiopathological elements affecting the amplitude of R waves.

Coronary Disease↗
PubMed1986

[Evaluation of the antihypertensive effect and tolerability of a new delayed-action calcium channel blocker: nitrendipine, prescribed as a single daily dose of 20 mg].

The authors have studied the effects of Nitrendipine, orally given in a dose of 20 mg, once a day for 30 days, in patients with mild to moderate hypertension. Twelve patients initially entered the study but four of them discontinued the treatment during the first week, because of unwanted side-effects: headaches, palpitation, sensations of burning skin. The remaining eight patients underwent a comparative evaluation at the end of a placebo period (DO) and at the end of the active treatment (D30), including successively: an automatic blood pressure recording with a Bard-Sentron device for 3 hours, then a determination of plasma renin activity, aldosterone and catecholamines, and finally a measurement of the blood pressure with a mercury manometer, at rest and during a standardized exercise on an ergometric bicycle. At D30, the Nitrendipine tablet was given one hour after the beginning of the automatic recording. The blood pressure measured with the mercury manometer (i.e. approximately 2 hours after the dose of Nitrendipine) significantly decreased from D0 to D30, at rest and during exercise, respectively from 161.5/104.6 to 132.8/82.5 mmHg and from 210.0/116.8 to 190.0/95.6 mmHg. The automatic recording provided, at D0, a mean blood pressure value of 152.4/90.6 mmHg; at D30, this mean value was as high as 142.6/90.7 mmHg during the hour preceding the dose of Nitrendipine (NS) and as high as 129.2/78.6 mmHg during the 2nd hour following the intake of the tablet (p less than 0.01). Plasma aldosterone and plasma renin activity significantly (p less than 0.05) increased from D0 to D30, whereas catecholamines did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Delayed-Action Preparations↗
PubMed1985

Effect of a calcium antagonist: verapamil on resting blood pressure and pressor response to dynamic exercise.

Effects of Verapamil, 120 mg t.i.d. in twenty-one hypertensive patients were assessed at rest and during dynamic exercise. The selection criterion was a diastolic blood pressure (DBP) found, at least 3 times, between 95 and 115 mmHg, not responding to placebo therapy. After 30 days of treatment with Verapamil, the resting systolic blood pressure (SBP) and DBP respectively decreased from 151.8 to 137.5 mmHg (p less than 0.001) and from 103.2 to 89.8 mmHg (p less than 0.001). The blood pressure (BP) and heart rate (HR) responses to dynamic exercise were also significantly blunted and the BP profile on effort was normalized in about half of the cases. Finally, the automatic recording of BP by a non invasive device showed a fall in the mean blood pressure (MBP) from 100.6 to 90.8 mmHg (p less than 0.001). The best results were obtained in patients with lower pretreatment plasma renin activity index and higher DBP or MBP automatically measured. The degree of response was not significantly related to age nor to plasma homovanillic acid level, which, however, significantly rose in all patients following therapy. This increase in sympathetic tone suggests a vasodilatory effect of Verapamil. The tolerance was good in all patients but four, whose electrocardiogram showed some alteration of atrio-ventricular conduction.

Adult↗
PubMed1984

[Congenital anomalies of the origin and/or distribution of coronary arteries originating from the aorta. Angiographic study of 39 cases].

39 cases of congenital anomalies in the origin and/or in the distribution of the coronary arteries arisen from the aorta, without associated cardiac abnormality, seen in the course of 6 525 selective coronary arteriographies in adults, are reported and integrated into a general classification of coronary arteries abnormalities. The clinical correlation of these anomalies is specified. The authors emphasize the importance of their diagnosis in the surgery of valve replacement or of myocardial revascularization.

Adult↗
PubMed1982

Genetic analysis of a streptomycin-resistant Escherichia coli mutant temperature-sensitive for nonsense suppression.

Continuing the genetic and biochemical characterization of the streptomycin-resistant Escherichia coli mutant LD1, we confirmed that LD1 is temperature-sensitive for suppression of nonsense codons, and that this phenotype of the mutant and its streptomycin-resistance are genetically linked and are probably caused by a single mutation, strA(LD1). We also isolated a spontaneous revertant, called LD1-R, which partially relieves the restriction of nonsense suppression caused by the strA(LD1) mutation. LD1-R is derived by an additional mutation (revA) which is closely linked to strA(LD1). We further demonstrate that the weak suppression of a lacZUGA mutation in a suppressor-free strain, which probably takes place by normal tRNA1rp, can be detected by the use of the chromagenic substance x-gal (5-Bromo-4-chloro-3-indolyl-beta-D-Galactopyranoside).

Codon↗
PubMed1982

Studies on the involvement of the UGA readthrough process in the mechanism of attenuation of the tryptophan operon of Escherichia coli.

We asked if UGA suppression by charged tRNATrp, a process called UGA readthrough, is involved in the mechanism of attenuation of the tryptophan (trp) operon in Escherichia coli. For this purpose we used two mutations: strA(LD1) which causes restriction of UGA readthrough, and revA which partially overcomes the restriction of UGA readthrough caused by strA(LD1)(Engelberg-Kulka et al. 1982). trp attenuation was monitored by the regulation of the synthesis of the trp operon enzyme anthranilate synthetase (ASase) in trpR strains. We showed that the strA(LD1) mutation causes a significant increase in the level of synthesis of ASase in the presence of an excess of tryptophan, while the revA mutation reverses this effect, indicating that transcription termination at the trp attenuator site is relieved by restriction of UGA readthrough. Based on our results and the sequence data of the trp leader RNA of E. coli (Oxender et al. 1979), we offer a model for the involvement of the UGA readthrough process in trp attenuation. We suggest that the UGA readthrough process permits trp attenuation to respond to slight changes in the cellular concentration of charged tRNATrp.

Anthranilate Synthase↗
PubMed1981

[Activity and tolerance of a new anti-arrhythmia drug, Cibenzoline (Cipralan), administered orally)].

The authors studied the effect of a new anti-arrhythmic agent, the Cibenzoline in 9 patients suffering from numerous ventricular extrasystoles (on average 8 extrasystoles/minute). Efficacy was considered to be excellent in 3 cases (complete disappearance of extrasystoles) good in 3 cases (more than 90% decrease in the number of extrasystoles) and poor in 3 cases (these concerned two patients also resistant to all other anti-arrhythmic agents and one patient with an extreme variability of his arrhythmia from one day to another day). Clinical and biological tolerance was excellent. Electrocardiographic parameters in general remained stable, apart from in one case of severe cardiomegaly. The general rules usually accepted for adequate evaluation of the efficacy of an anti-arrhythmic agent are reviewed and discussed.

Administration, Oral↗
PubMedDate not supplied

[Identification of overtreated hypertension with statistical analysis of 100 consecutive ambulatory blood pressure monitoring].

The data obtained from 100 consecutive ambulatory blood pressure (BP) recordings performed in treated hypertensive patients (60 men, 40 women, mean age 52 +/- 14 years) were analysed to make a choice between several possible definitions of overtreatment and to evaluate the prevalence of patients thus defined as overtreated. Recordings were studied over two periods: diurnal from 9 a.m. to 7 p.m. (100 patients, 37 +/- 5 measurements/patient), and nocturnal from 11 p.m. to 7 a.m. (98 patients, 19 +/- 2 measurements/patient). The patients were first classified on the basis of reference ambulatory BP values according to sex and age. Subnormal levels were found in 25 patients for diurnal SBP, 25 for nocturnal SBP, 13 for diurnal DBP and 33 for nocturnal DBP. Several criteria of overtreatment were then tested, based on the percentile method and on the number of subnormal values: the median DBP was below the 30th reference percentile in 16 patients, and the percentage of subnormal DBP values was above 80% in 18 patients. Clinically, there was little to differentiate these patients from the rest of the population treated. The goal of treatment which, in terms of BP values, is to normalize the ambulatory BP was therefore overshot in 1 out of 5 or 6 patients depending on the criteria adopted. The significance and consequences of overtreatment cannot yet be evaluated.

Adult↗
PubMedDate not supplied

Asynchronous replication of allelic loci in Down syndrome.

We have used FISH to determine the level of synchronisation in replication timing of four pairs of alleles, unrelated to chromosome 21 (p53, HER2, RB1, and c-myc), in foetal (amniotic fluid) cell samples of Down syndrome and in normal foetuses. All samples derived from the Down syndrome subjects showed large temporal differences in replication timing, in contrast to the high level of synchrony shown in all samples of normal individuals. Thus, as judged by four independent loci which are not associated with chromosome 21, the additional chromosome in the Down syndrome genome induces changes in the replication pattern of an allelic pair: from a synchronous pattern characteristic to concomitantly expressed alleles to an unsynchronised one shown by alleles displaying an allele-specific mode of expression.

Alleles↗
PubMedDate not supplied

Asynchronous replication of alleles in genomes carrying an extra autosome.

Transcriptional activity of genes appears to be highly related to their replication timing; alleles showing the common biallelic mode of expression replicate highly synchronously, whereas those with a monoallelic mode of expression replicate asynchronously. Here we used FISH to determine the level of synchronisation in replication timing of alleles in amniotic fluid cells derived from normal foetuses and from those with either of the trisomies for autosomes 21, 18 or 13, or for sex chromosomes (47,XXX and 47,XXY). Two pairs of alleles, not associated with the extra chromosome, were studied in subjects with each trisomy and three in normal subjects. In cells derived from normal foetuses and from foetuses with sex chromosome trisomies, each pair of alleles replicated synchronously; yet these very same alleles replicated asynchronously in cells derived from foetuses with trisomy for any of the three autosomes studied. The results suggest that the gross phenotypic abnormalities associated with an extra autosome are brought about not only by over-expression of genes present in three doses, but also by modifications in the expression of genes present in the normal two doses.

Alleles↗
PubMedDate not supplied

Comparing the genetic changes detected in the primary and secondary tumor sites of ovarian cancer using comparative genomic hybridization.

Our objective was to compare the genetic abnormalities in the primary tumors of epithelial ovarian cancer and their associated secondary peritoneal implants using comparative genomic hybridization (CGH). CGH was performed on seven apparent stage III ovarian serous cancer cases. Dissected tissue samples from the primary tumor and from the metastatic peritoneal implant were obtained at initial surgical staging and analyzed in each case. We used CGH as this technique allows the entire genome of the tumor to be examined simultaneously for chromosomal imbalances without the need for tissue culture or targeting of specific loci. The chromosomal abnormalities detected in the distinct sites were then reviewed and compared. CGH studies were successful in all 14 samples from the seven patients. The analysis revealed chromosomal aberrations in six patients with certain repeated changes as amplification of 1q, 2p, 2q, 3q, 6q, 8q, and 12p and underrepresentation of 18q and X chromosomes. Comparing the genomes of the primary tumors with the metastatic samples showed four cases with a balanced metastatic CGH profile while the primary site was aberrant. Greater chromosomal complexity associated with the primary site was detected in two other patients. In one case, both primary and secondary sites had no detectable chromosomal imbalances. The cytogenetic patterns in six of the seven primary tumors showed complex karyotypic changes, unlike the inconsistent findings that were associated with the secondary sites. The chromosomes of the secondary sites expressed either normal genomes or fewer genetic aberrations. Such genomic heterogeneity between the primary and secondary sites may indicate that the secondary peritoneal implants are de novo carcinogenesis occurrences. The results may support the concept that at least part of advanced ovarian cancer is a multicentric disease in the early stages. Further genetic studies are needed to reassess this assumption.

Chromosome Aberrations↗