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Biomedical subjects

S Roux

Publications and source records attributed to S Roux.

At least 145 records · Page 8Linked to original sources
PubMed1991

Improved mammographic accuracy.

Use of ancillary imaging studies to evaluate suspicious screening mammograms can improve their positive predictive value for detecting malignant lesions. In 1989 8181 screening mammograms were performed at the breast evaluation center at Memorial Hospital Medical Center in Long Beach. A total of 670 patients were called back for magnification views or ultrasonographic evaluation, and 92 of these patients underwent surgical biopsy. There were 42 cancers diagnosed, yielding an accuracy rate of 46%.

Biopsy, Needle↗
PubMed1991

Auditory evoked responses (AER) and augmenting-reducing phenomenon in patients with progressive supranuclear palsy (PSP).

Variations in amplitude and latency of P1, N1 and P2 waves of AER induced by increasing the stimulus intensity (augmenting-reducing) were measured in PSP patients and compared to those observed in normal subjects. The studied population included 17 patients (10 male, 7 female, mean age 66 +/- 8 yr) with a typical PSP symptomatology and 17 normal subjects (10 male, 7 female, mean age 66 +/- 9 yr). All subjects from both the groups showed a normal auditory threshold (less than 30 db SPL or a moderately increased threshold never exceeding 10 db SPL). Nine patients had normal BAER; 4 patients showed an abnormal III wave; 3 patients showed an abnormal V wave. One patient had a poorly individualized BAER. Latencies and amplitudes of P1, N1 and P2 waves derived from Cz and Fz (linked ear reference) were studied with 50, 60, 70 and 80 db intensities and for each patient slopes of amplitude-stimulus intensity and latency-stimulus intensity curves were studied. Although patients showed decreased AER amplitudes, the augmenting-reducing phenomenon was not different from controls regarding either latency or amplitude changes with increasing stimulus intensity. Previous studies had established a negative correlation between the augmenting-reducing responses and HVA levels in the cerebrospinal fluid (CSF). Similarity of augmenting-reducing mechanisms in PSP and normal subjects favors the hypothesis of unimpaired mesocortical and mesolimbic dopaminergic pathways in PSP. This hypothesis is also supported by postmortem studies using biochemical markers.

Aged↗
PubMed1990

The Behavioral Summarized Evaluation: validity and reliability of a scale for the assessment of autistic behaviors.

The Behavioral Summarized Evaluation (BSE), is a 20-item paper-and-pencil rating scale specifically designed for the measurement of behavioral parameters which could be related to biological data in autistic children involved in educational programs, neurophysiological studies, and therapeutic trials. The development of the scale, the validity, and reliability studies are presented in this paper. The results suggest that the BSE is an acceptable tool for the assessment of autistic behaviors, easy to handle, and accessible to both professionals and paraprofessionals of the medico-educative staff. It is a useful addition to the bioclinical researcher's evaluation battery for bioclinical and therapeutic studies. However, more work is suggested to further investigate the psychometric properties of this behavior assessment instrument.

Adolescent↗
PubMed1990

Influence of lateralized sensorimotor and neuropsychological activities on electroencephalographic spectral power.

In order to test the effect of 'lateralized' sensorimotor and neuropsychological activities on EEG spectral power (P), we recorded EEGs over the right and left central regions with 3 different derivations C5P3/C6P4, C5Cz/C6Cz, and C5 ears-linked (EL)/C6EL in 14 young, right-handed men who underwent ten 2 min sequences including 4 during rest (3 with eyes closed (EC), 1 with eyes open (EO], and 6 during tasks reputed to involve preferentially the left (Le) or the right (Ri) hemisphere, i.e., pure left and pure right motor activity of the hand (EC), pure neuropsychological tasks consisting in lexical followed by spatial form analysis and finally mixed (neuropsychological and motor) EC tasks consisting in writing followed by left hand object recognition. Three spectral parameters P, log P and asymmetry index AI = (P Ri-P Le)/(P Ri + P Le) were calculated in 5 frequency bands theta, alpha 1, alpha 2, alpha 3 and beta 1. We observed a relationship between task complexity and P reduction on both hemispheres which was greater during rest, less during motor activity and least during mixed motor and neuropsychological activities; during EC activities more specifically involving the left hemisphere, only the comparison between rest and mixed sequences was significant. During EC activities involving the right hemisphere, both motor and mixed sequences were significantly different from rest sequences. In addition, during the EO sequences, P was usually greater than during rest. As compared to rest conditions, the AI increased during sequences preferentially involving the left hemisphere and decreased during preferentially right hemisphere activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Spectral analysis of the EEG (alpha rhythm) and activity in the left hemisphere: the effects of lateral gaze.

This study tests the effect of maintaining right and left lateral gaze during a writing task which preferentially implicates the left hemisphere using an asymmetry parameter calculated from the spectral power of the alpha rhythm (RP-LP/RP + LP) in a right-handed patient undergoing the same experimental regimen nine times. A six derivation EEG was recorded. Maintaining left lateral gaze (toward the active hemisphere) removes the lateralization found during writing while staring straight ahead whereas maintaining right lateral gaze (toward the side opposite the active hemisphere) results in slightly lower values which are however, not significantly different from those obtained during staring straight ahead. This study adds an electrophysiologic aspect to Kinsbournes's paradigm on gaze position and hemispheric activation.

Adult↗
PubMed1990

Aprotinin: an antidote for recombinant tissue-type plasminogen activator (rt-PA) active in vivo.

The goal of the study was to assess if aprotinin, a protease inhibitor, could be used to antagonize in vivo the effects of recombinant tissue-type plasminogen activator (rt-PA). The time course of the lysis of a radioactive jugular vein thrombus was monitored continuously with an external gamma counter in anesthetized rabbits. Recombinant t-PA (0.25 mg) was given intravenously as a bolus injection (10% of the dose), followed by a 4 h infusion (90% of the dose). Rabbits received aprotinin 20 min after the start of the infusion as an intravenous bolus injection at a dose of 60,000 IU/kg (n = 4) or 20,000 IU/kg (n = 4). The rate of lysis in the different groups was compared 2, 60 and 180 min after aprotinin administration. Both doses of aprotinin immediately stopped thrombolysis. Thrombolysis was still blocked at 180 min with the highest dose but not with the lowest dose. Moreover, aprotinin could prevent the increase in bleeding time secondary to the injection of rt-PA. These results suggest that aprotinin might be used in vivo as an antidote for rt-PA.

Animals↗
PubMed1989

Effect of age on auditory evoked responses (AER) and augmenting-reducing.

Auditory evoked responses (AER) were obtained from Cz and Fz in 30 adults (14 male, 16 female) from 20-80 years old. Sound bursts (1000 Hz-200 msec) of four different intensities were used. Peak to trough amplitudes of P1N1 and N1P2 and latencies of P1, N1 and P2 peaks were measured with increasing stimulus intensity and slopes of amplitude - intensity and latency - intensity curves were analysed for assessment of an age effect. The main result is that the increase in P1N1 amplitude with increasing stimulus intensity is more pronounced in older persons. Previous studies have established a negative correlation between the augmenting-reducing responses and HVA levels in the CSF (with lower amounts of HVA in the CSF of "augmenters"). Decreased dopamine metabolism in old subjects could account for our results, so further studies should focus on patients with pathological dopamine deficiencies.

Acoustic Stimulation↗
PubMed1989

Electrophysiological effects of fenfluramine or combined vitamin B6 and magnesium on children with autistic behaviour.

The authors compared the effects of fenfluramine or combined vitamin B6 and magnesium treatment on the evoked potential conditioning of 12 children whose autistic behaviour had improved clinically following treatment. The children who were clinically sensitive to combined vitamin B6 and magnesium developed a conditioning phenomenon and the fenfluramine-sensitive children showed an enhancement of the Cz evoked response amplitude. Results are discussed with reference to behaviour modifications observed during treatment.

Autistic Disorder↗
PubMed1989

Effects of lidocaine on sarcolemmal fluidity and cellular cAMP in rat cardiomyocytes.

Antiarrhythmic drugs with local anesthetic properties modify the physical state of membrane phospholipids and could change adenylate cyclase activity and, thus, influence cardiac ischemic arrhythmias. Adenosine 3',5'-cyclic monophosphate (cAMP) accumulation in cardiomyocytes cultured from newborn rat and fluorescence anisotropy of sarcolemma-enriched membranes were investigated in the presence of a neutral anesthetic drug benzyl alcohol and of a cationic anesthetic drug lidocaine. Benzyl alcohol increased in a dose-dependent manner both sarcolemma fluidity and isoproterenol- or cholera toxin-stimulated cAMP accumulation. In contrast, benzyl alcohol inhibited cAMP accumulation in forskolin-stimulated cells. Lidocaine induced a dose-related inhibition of isoproterenol-, forskolin-, and cholera toxin-stimulated cAMP accumulation without eliciting any change in sarcolemma fluidity. The inhibitory effect of lidocaine on isoproterenol-stimulated cAMP accumulation was reversed when cells were pretreated with pertussis toxin. These data suggest that the inhibitory effect of lidocaine on cAMP synthesis might involve a polar interaction with the Gi regulatory subunit of adenylate cyclase. Such an effect could contribute, in vivo, to both the antiarrhythmic and the negative inotropic effect of lidocaine.

Adenylate Cyclase Toxin↗
PubMed1989

Auditory evoked potential modifications according to clinical and biochemical responsiveness to fenfluramine treatment in children with autistic behavior.

Evoked potentials to auditory stimulations varying in intensity were studied in 13 children with autistic behavior treated with fenfluramine. Modifications of both amplitude and single-trial potential variability were considered according to the clinical and biochemical responsiveness to this drug. Six children (responders) were clinically improved by the treatment. Electrophysiological data were affected according to the clinical and biochemical responsiveness to fenfluramine: the auditory evoked potential amplitude increased, and the single-trial potential variability decreased at each intensity level only in responders whose dopaminergic metabolism was significantly modified by fenfluramine treatment. No modification was found in nonresponders. Both biochemical and electrophysiological results argued for an amphetamine-like action of fenfluramine in those autistic children whose attention deficits are associated with motor disturbances including hyperactivity.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1989

[Angiography of right ventricular volume after surgical repair of tetralogy of Fallot].

Right ventricular volume and ejection fraction were measured in children who had undergone surgical repair for tetralogy of Fallot with excellent results. Fourteen children who had been operated upon at the age of 3 +/- 2.6 years had cardiac catheterization and cineangiography of the right ventricle at the age of 4.6 +/- 2.7 years. Right ventricular volumes were determined from single-plane cineangiography in right anterior oblique projection (Ferlinz method). Eleven children with a normal right ventricle served as controls. Dual projection cineangiography of the pulmonary artery enabled the pulmonary insufficiency to be divided into 4 grades. Echocardiography with colour-coded doppler velocimetry was also performed, showing the absence of residual shunt and of tricuspid, mitral and aortic valve abnormalities. The extension of pulmonary regurgitation flow to the right ventricle was analysed and divided into 4 grades. Pulmonary insufficiency was present in all patients; it was graded 1 or 2 by the two methods in 8 cases (group A) and 3 or 4 by one or the other of the two methods in 6 cases (group B). In 7 patients of group A the operation had included the insertion of a small patch to widen the pulmonary channels (infundibulum alone in 3 cases, transvalvular in 4 cases); in 5 patients of group B a large infundibulo-pulmonary transvalvular patch had been installed. The right ventricular systolic pressure was always below 50 mmHg (mean: 40.9 +/- 6.7 mmHg) and the systolic gradient between right ventricle and pulmonary artery never exceeded 30 mmHg (mean: 14.9 +/- 6.2 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiocardiography↗