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Biomedical subjects

P Simon

Publications and source records attributed to P Simon.

At least 451 records · Page 25Linked to original sources
PubMed1984

[Spontaneous rupture of an aneurysm of the splenic artery in pregnancy. Apropos of a new case].

The authors report a case of a two para who was admitted as an emergency after collapsing at the end of her pregnancy. Various clinical examinations carried out on admission showed that she was in a state of hypovolemic shock with a marked drop in her blood pressure and a fast pulse as well as pain in the left hypochondrium radiating up to her shoulder. From the obstetrical point of view, there had been no bleeding and no uterine contractions and the fetal heart tracing showed a rate of 135. After intensive efforts at resuscitation an urgent laparotomy was carried out with as a first step Caesarian section which confirmed that there was no pathology in the placenta or uterus, followed by exploration of the abdominal cavity which revealed a large retro-peritoneal haematoma together with a ruptured aneurysm in the hilum of the spleen. Splenectomy was carried out after haemostasis of the splenic pedicle had been performed and this allowed her to recover without complications. Following this case the authors looked up the world literature and confirmed that the pathology was classic but very rare indeed, there being only 66 published cases. As far as its aetiology was concerned this aneurysm is not the same as a classical splenic aneurysm. The development of the aneurysm seems to take place during the pregnancy and the reason for this arterial aneurysm and its rupture in unknown. A theory has been advanced that circulatory and haemodynamic factors acquired in pregnancy reveal the congenital factor that is already present.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Psychopharmacological profile of diphenylhydantoin in mice.

The pharmacological profile of diphenylhydantoin has some common features with that of classical antidepressants: it decreases motor activity in mice it shortens the period of immobility of mice in the "behavioral despair" test it antagonizes palpebral ptosis induced by reserpine in mice.

Animals↗
PubMed1984

[The tiapride-ethanol interaction in animals].

Tiapride ip-ethanol vo combined in animals showed on three psychopharmacological tests that: decreased motor activity induced by tiapride in mice was slightly pronounced; catalepsy induced by tiapride in rats was slightly increased; sleeping time induced by ethanol in mice was not potentiated.

Animals↗
PubMed1983

Spin label studies on synaptosomal membranes of rat brain cortex during aging.

Membrane lipids of brain synaptosomes of 2, 12 and 24 months old rats were labeled by stearic acid spin probes with a doxyl group in the C-5 and C-16 position, respectively. We demonstrated that the hydrophobic region of synaptosomal membranes became more rigid during the life span studied, and the region located nearer the surface of membranes displays a significantly decreased fluidity only in the oldest group. Membrane proteins labeled with a nitroxide derivative of maleimide suggest that conformational changes take place during aging.

Aging↗
PubMed1983

A human leukocyte differentiation antigen family with distinct alpha-subunits and a common beta-subunit: the lymphocyte function-associated antigen (LFA-1), the C3bi complement receptor (OKM1/Mac-1), and the p150,95 molecule.

The human lymphocyte function-associated antigen-1 (LFA-1), the complement receptor-associated OKM1 molecule, and a previously undescribed molecule termed p150,95, have been found to be structurally and antigenically related. Each antigen contains an alpha- and beta-subunit noncovalently associated in an alpha 1 beta 1-structure as shown by cross-linking experiments. LFA-1, OKM1, and p150,95 alpha-subunit designations and their molecular weights are alpha L = 177,000 Mr, alpha M = 165,000 Mr, and alpha X = 150,000 Mr, respectively. The beta-subunits are all = 95,000 Mr. Some MAb precipitated only LFA-1, others only OKM1, and another precipitates all three antigens. The specificity of these MAb for particular subunits was examined after subunit dissociation by high pH. MAb specific for LFA-1 or OKM1 bind to the alpha L- or alpha M-subunits, respectively, while the cross-reactive MAb binds to the beta-subunits. Coprecipitation experiments with intact alpha 1 beta 1-complexes showed anti-alpha and anti-beta MAb can precipitate the same molecules. In two-dimensional (2D) isoelectric focusing-SDS-PAGE, the alpha subunits of the three antigens are distinct, while the beta-subunits are identical. Biosynthesis experiments showed alpha L, alpha M, and alpha X are synthesized from distinct precursors, as is beta. The three antigens differ in expression on lymphocytes, granulocytes, and monocytes. During maturation of the monoblast-like U937 line, alpha M and alpha X are upregulated and alpha L is downregulated. Some MAb to the alpha subunit of OKM1 inhibited the complement receptor type three. LFA-1, OKM1, and p150,95 constitute a novel family of functionally important human leukocyte antigens that share a common beta-subunit.

Antibodies, Monoclonal↗
PubMed1983

Attempt at pharmacological differentiation of central beta-adrenergic receptors.

The beta-adrenergic stimulants isoprenaline, salbutamol and clenbuterol decreased motor activity, reduced the interest of fasting mice in food pellets ('Tantale' test), and antagonized high-dose apomorphine hypothermia. Clenbuterol was 16--60 times more potent than the other two agonists in all tests, apparently because of better crossing into the C.N.S. The beta-adrenergic blockers, d,l-propranolol and l-penbutolol, completely antagonized the effects of salbutamol and clenbuterol in tests of motor activity and apomorphine hypothermia, penbutolol being 30--60 times more active than propranolol, perhaps due to its greater lipid solubility. The Tantale test allows unambiguous differentiation between penbutolol and propranolol. While the first completely blocked the effects of clenbuterol and salbutamol, the second was effective only within a narrow dose range. Finally, the dose-effect relationships of the 3 agonists were parallel in the Tantale test, while they were divergent in the other two. This suggests that different classes of beta-adrenergic receptors may be involved in the various test.

Adrenergic beta-Agonists↗
PubMed1983

Mapping of antigenic and functional epitopes on the alpha- and beta-subunits of two related mouse glycoproteins involved in cell interactions, LFA-1 and Mac-1.

Mouse Mac-1, a complement receptor-associated surface structure on macrophages, and LFA-1, a function-associated structure on lymphocytes, comprise a novel family of leukocyte differentiation antigens participating in adhesive cell interactions. Mac-1 and LFA-1 contain alpha-subunits of 170,000 and 180,000 Mr, respectively, and beta-subunits of 95,000 Mr noncovalently associated in alpha 1 beta 1 complexes. The structural relation between the alpha- and between the beta-subunits, and the location of functionally important sites on the molecules, have been probed with antibodies. Both non-cross-reactive and cross-reactive monoclonal antibodies (MAb) and antisera prepared to the purified molecules or the LFA-1 alpha-subunits were used. Reactivity with individual subunits was studied by immunoprecipitation after dissociation induced by high pH treatment, or by immunoblotting after SDS-PAGE. Cross-reactive epitopes on Mac-1 and LFA-1 were found to be present on the beta-subunits, which were immunologically identical. Non-cross-reactive epitopes that are distinctive for Mac-1 or LFA-1 were localized to the alpha-subunits. MAb to LFA-1 alpha-subunit epitopes inhibited CTL-mediated killing. Two MAb to Mac-1 alpha-subunit epitopes but not a third MAb to a spatially distinct alpha-epitope inhibited complement receptor function. Neither function was inhibited by a MAb binding to a common beta-subunit epitope. Therefore, sites of Mac-1 and LFA-1 involved in their respective adhesion-related functions, as well as distinctive structural features, have been localized to the alpha-subunits.

Animals↗
PubMed1983

Diazepam-induced release of behavior in an extinction procedure: its reversal by Ro 15-1788.

The effects of the benzodiazepine receptor antagonist Ro 15-1788, an imidazobenzodiazepine derivative, were studied with respect to three pharmacological activities exerted by diazepam in rats. Two of these, release of shock-induced suppression of drinking and attenuation of non-reward-induced cessation of responding for food, reflect the anxiolytic property of benzodiazepines. The amnesic-like effect of diazepam was also investigated. Ro 15-1788 (in doses ranging from 4 to 16 mg/kg p.o.) completely reversed diazepam (2 mg/kg)-induced release of behavior in both punishment and non-reward procedures. In contrast, Ro 15-1788 reduced but did not completely abolish diazepam-induced amnesia. These data suggest that the anticonflict and anti-frustration effects of benzodiazepines probably involve similar receptor types which nevertheless differ from those chiefly implicated in the amnesic-like activity of benzodiazepines.

Amnesia↗
PubMed1983

The progressive ratio schedule as a model for studying the psychomotor stimulant activity of drugs in the rat.

Male Wistar rats were trained to press a lever with food reinforcement according to a continuously reinforced schedule (CRF). Afterwards, rats were subjected to three experimental sessions (30 min each) during which responding was rewarded according to a progressive ratio schedule (following an initial 2-min CRF period, the number of presses necessary for the pellet delivery was doubled every second minute). Responding during the first half of each session, i.e., pressing for food, was maintained at a significant level, whereas it was almost suppressed during the second part of the session. As compared to controls (200 +/- 20 presses/30 min) animals given amfonelic acid (0.5, 1 mg/kg IP), methylphenidate (4, 8 mg/kg IP), caffeine (16 mg/kg IP), cocaine (4 mg/kg IP), oxolinic acid (32 mg/kg IP), nomifensine (4 mg/kg IP), DR 250 (2, 4 mg/kg IP) and d-amphetamine (0.25, 0.5, 1 mg/kg IP) showed an increased rate of responding ranging from 400 to 950 presses/30 min. In contrast, apomorphine, MK 486 + L-dopa, trihexyphenidyl, imipramine, salbutamol and diazepam did not increase responding. These results suggested that this test is highly sensitive for psychomotor stimulants and perhaps for their ability to enhance the reinforcing value of the reward or stimuli associated with the reward. Such activity seemed related to a catecholaminergic substrate since the increase of responding induced by amphetamine was blocked by pimozide, d,l-propranolol and prazosin.

Animals↗
PubMed1983

[Indices of progression of IgA glomerulopathy].

A retrospective and prospective study of 58 patients with IgA glomerulonephritis was undertaken between the 1st April 1975 and the 1st May 1982, to determine the clinical, biological and histological features associated with the onset of renal failure and a poor prognosis. At the end of this study the patients were classified into 4 groups according to the clinical stage of their disease: a) normal, b) minor urinary abnormalities, c) active disease and d) terminal renal failure. The renal biopsies were reviewed and an index of histological activity defined. The significant features associated with progression of the disease to renal failure were: persistent proteinuria, a transient nephrotic syndrome, hypertension, diffuse proliferative glomerular changes with epithelial crescent formation, tubulo-interstitial changes and vascular lesions on renal biopsy. When confronted with the clinical outcome, the histological results of the first renal biopsy performed when the disease was first diagnosed and quantified in an index of activity, had a good predictive value.

Adolescent↗
PubMed1983

Hypnotic activity of brotizolam: a study in general practice.

A double-blind, crossover study was carried out in general practice on the hypnotic activity of 0.25 mg brotizolam in patients aged between 18 and 70 years complaining of insomnia (11 men, 28 women). Patients reported that they slept better, that they awoke less frequently and that they slept longer with brotizolam than with placebo. Overall the patients preferred brotizolam to placebo, and subjective assessments of well-being after brotizolam did not differ from those after placebo. Brotizolam was well tolerated and there were no incidents of note.

Adolescent↗
PubMed1983

Pharmacology of hypnotics.

Sedative hypnotics belong to several chemical classes and thus have heterogeneous pharmacodynamic properties. Among various ways of approaches, conventional pharmacology using animal models allows one to define a common pharmacological profile. It still remains the best predictive tool of hypnotic efficacy in man. The study of discriminative properties is a useful extension of these conventional models. Electrophysiological and biochemical studies allow primarily to approach the problems of the sites and mechanisms of action, but only begin at the moment to lead to practical applications.

Aggression↗