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S Picard

Publications and source records attributed to S Picard.

At least 91 records · Page 5Linked to original sources
PubMed1986

[The Capgras syndrome].

A new case of Capgras' syndrome is presented with a short review on the subject. Since there are many controversies about the etiology of this syndrome, and since some authors explain it with organic factors, others with psychodynamic factors, or a combination of the two, one should be careful with this syndrome to eliminate the presence of organic factors with a meticulous physical examination and appropriate neuropsychological tests. A thorough examination of early interpersonal relations is necessary to verify psychodynamic hypothesis, the most plausible being the splitting of internalized object representations.

Adult↗
PubMed1985

Ninhibin: a sperm factor attenuates the atrial natriuretic factor mediated inhibition of adenylate cyclase: possible involvement of inhibitory guanine nucleotide regulatory protein.

The effect of ninhibin, a sperm factor extracted from bovine sperm, was studied on adenylate cyclase from rat aorta. Ninhibin treatment of the membranes activated adenylate cyclase in a concentration dependent manner. The maximal activation (approximately equal to 4-fold) was obtained at 2micrograms ninhibin and at 10 min of treatment at 37 degrees C. On the other hand, in untreated control membranes, ninhibin at 2 micrograms could stimulate adenylate cyclase by about 50-60% only. In addition, ninhibin potentiated the guanine nucleotide-, isoproterenol- and forskolin (FSK)-stimulated adenylate cyclase activities and also attenuated the GTP gamma s and atrial natriuretic factor (ANF)-mediated inhibition of enzyme activities. Furthermore the inhibition of isoproterenol- and FSK-stimulated adenylate cyclase activities by ANF was also abolished by ninhibin. These data indicate that ninhibin which has been suggested to inactivate or inhibit Ni-guanine nucleotide regulatory protein can also attenuate the ANF-receptor mediated inhibition of adenylate cyclase in rat aorta suggesting an involvement of Ni-guanine nucleotide regulatory protein in the coupling of ANF receptors to adenylate cyclase.

Acrosin↗
PubMed1984

Eosinophil-rich human polymorphonuclear leukocyte preparations characteristically release leukotriene C4 on ionophore A23187 challenge.

Blood samples were obtained from a group of 20 patients with hypereosinophilia (greater than or equal to 1500 eosinophils/mm3). The polymorphonuclear leukocytes (PMNLs) were prepared from blood treated with ethylenediaminetetra-acetic acid by successive dextran sedimentation of the red blood cells, separation of mononuclear leukocytes and PMNLs on Ficoll-Paque, and ammonium chloride treatment of the PMNL fraction. The eosinophil content of the final PMNL preparations ranged from 15% to 75%, as assessed by Wright-stained smears, and the remaining leukocytes were predominantly neutrophils with only 3% to 5% mononuclear cells. The eosinophil-rich PMNL preparations as well as PMNL preparations from normal volunteers were incubated under various conditions and the arachidonic acid metabolites were analyzed by reverse-phase high-performance liquid chromatography. The synthesis of 5-lipoxygenase products was strongly stimulated by the ionophore A23187 in both normal and eosinophil-rich PMNL preparations. Whereas the normal PMNL preparations, which were eosinophil poor, produced 10 to 25 times more leukotriene B4 than leukotriene C4, the eosinophil-rich PMNL preparations characteristically released leukotriene C4 in equal or up to 20 times greater amounts than leukotriene B4.

Arachidonate Lipoxygenases↗
PubMed1984

Studies on leukotriene B4 omega-oxidation in human leukocytes.

The kinetics of the transformation of arachidonic acid into 5-lipoxygenase products in human blood leukocytes stimulated with the ionophore A23187 (2 microM) was studied using high performance liquid chromatography. The levels of 5-hydroxyeicosatetraenoic acid (5-HETE), leukotriene B4 (LTB4), delta 6-trans-LTB4, and leukotriene C4 (LTC4) were maximum after 4-5 min of incubation; at longer incubation times, the levels of delta 6-trans-LTB4 and LTC4 remained unchanged, whereas those of 5-HETE and LTB4 decreased rapidly. The disappearance of LTB4 was concomitant with the formation of omega-hydroxy-LTB4 and omega-carboxy-LTB4. When synthetic LTB4 was added to a suspension of unstimulated human leukocytes, a similar pattern of omega-oxidation products was observed. This omega-oxidation process showed some specificity for LTB4, as indicated by the slower reaction of three stereoisomers of LTB4. Studies with subpopulations of human blood cells and human plasma clearly indicated that the polymorphonuclear leukocytes were the main source of enzymic activity for the omega-oxidation of LTB4. The liquid chromatographic behaviors of natural omega-hydroxy-LTB4 and omega-carboxy-LTB4 were studied in two systems.

Calcimycin↗
PubMed1982

Specificity of the effect of lipoxygenase metabolites of arachidonic acid on calcium homeostasis in neutrophils. Correlation with functional activity.

The ability of the major neutrophil-derived lipoxygenase metabolites of arachidonic acid to increase the rate of 45Ca influx in rabbit neutrophils was examined. The results obtained demonstrate that (5S),(12R)-dihydroxy-6,8,11,14-(cis,trans,trans,cis)-eicosatetraenoic acid (leukotriene B4) is the most active of the arachidonic acid metabolites. The activity of leukotriene B4 is highly stereospecific in that its three nonenzymatically derived isomers are essentially inactive. The omega-hydroxylation of leukotriene B4 results in a compound that is nearly as active as leukotriene B4 as far as its ability to stimulate calcium influx and neutrophil aggregation while being a much weaker secretagogue. The further conversion of leukotriene B4 into a dicarboxylic acid removes all detectable biological activity. 5,6-Oxido-7,9,11,14-eicosatetraenoic acid (leukotriene A4) methyl ester was also found to increase the rate of calcium influx, while the degradation products of native leukotriene A4 were essentially inactive. These results demonstrate that a close correlation exists between the ability of the various lipoxygenase products to alter calcium homeostasis in rabbit neutrophils and their biological activities.

Animals↗
PubMed1982

Metabolism of arachidonic acid in leukocytes: isolation of a 5,15-dihydroxy-eicosatetraenoic acid.

A novel metabolite of arachidonic acid was isolated from incubations of peripheral blood leukocytes with the fatty acid and the ionophore A23187. The compound was purified by high performance liquid chromatography and identified by ultraviolet photometry and gas chromatography-mass spectrometry as a 5,15-dihydroxy-6,8,11,13-eicosatetraenoic acid. The compound was also isolated from incubations of human leukocytes with the 15S-hydroperoxy-5,8,11,13(Z,Z,Z,E)-eicosatetraenoic acid, suggesting a double dioxygenation mechanism in the formation of this new metabolite of arachidonic acid. A 5S,15S-dihydroxy-6,8,11,13(E,Z,Z,E)-eicosatetraenoic acid was obtained from incubations of 5S-hydroxy-6,8,11,14(E,Z,Z,Z)-eicosatetraenoic acid with the soybean lipoxygenase and reduction with stannous chloride, and was used as reference compound.

Animals↗
PubMed1982

Studies on the mechanism of formation of the 5S, 12S-dihydroxy-6,8,10,14(E,Z,E,Z)-icosatetraenoic acid in leukocytes.

Incubation of peripheral blood leukocytes with arachidonic acid (and ionophore A23187) led to the formation of leukotriene B4, delta 6-trans-leukotriene B4, delta 6-trans-12-epi-leukotriene B4, 5-hydroxy-icosatetraenoic acid, 12-hydroxy-icosatetraenoic acid and of 5S,12S-dihydroxy-6,8,10,14-(E,Z,E,Z)-icosatetraenoic acid (5S,12S-DiHETE). Incubation of leukocytes with leukotriene A4 resulted in the formation of leukotriene B4 and of its two delta 6-trans-isomers but not of the 5S, 12S-DiHETE. 18O2 labeling experiments have shown that the hydroxyl groups at C5 and C12 in the 5S,12S-DiHETE are derived from molecular oxygen. The tetraacetylenic analog of arachidonic acid was found to be potent inhibitor of the formation of the 5S,12S-DiHETE whereas it potentiated the synthesis of the 5-hydroxy acid and of leukotriene B4. Addition of the 12-hydroxy-icosatetraenoic acid to leukocytes, or of the 5-hydroxy-icosatetraenoic acid to a suspension of platelets caused the formation of the 5S,12S-DiHETE. It is concluded that the 5S,12S-DiHETE is not derived from leukotriene A4 but is a product of the successive reactions of arachidonic acid with two lipoxygenases of different positional specificities.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1982

Evidence for a mediator role of thromboxane A2 in the myotropic action of leukotriene B4 (LTB4) on the guinea-pig lung.

The mechanism of action of LTB4 has been investigated on the guinea-pig lung parenchymal strip. Mepacrine (20 microgram/ml), an inhibitor of phospholipase A2, abolished the action of LTB4 on parenchymal strips. Eicosatetraynoic acid (10 microgram/ml) and BW755C (40 microgram/ml) which are inhibitors of cyclooxygenase and lipoxygenase pathways, produced a marked inhibition of the lung strip contraction to LTB4. Similarly, aspirin (30 micrograms/ml) and flufenamate (1 microgram/ml) showed a strong inhibition of the contraction of parenchymal strips to LTB4; these results suggested that cyclooxygenase products mediate the action of LTB4. The response to LTB4 was unaffected by 15-hydroperoxyeicosatatraenoic acid (15-HPETE; 1 microgram/ml) while L8027 (25 ng/ml) reduced the contraction by 50%, suggesting that thromboxane A2 rather than prostacyclin was involved. Since parenchymal strips do not appear to be very sensitive to PGF2 alpha, PGE2 and the endoperoxides, and since effluents from LTB4-treated lungs produced contractions of lung strip and rabbit aorta which were reduced after 5 min. at 25 degrees, thromboxane A2 was postulated to mediate the lung effect of LTB4. The release of thromboxane B2 (TxB2) from lungs stimulated with LTB4 was confirmed by gas-chromatography-mass spectrometric (GC-MS) analyses.

Animals↗
PubMed1982

Characterization of the secretory activity of leukotriene B4 toward rabbit neutrophils.

We have described in det ail the secretory activity of leukotriene B4 toward rabbit neutrophils. Leukotriene B4 rapidly and vigorously degranulates rabbit neutrophils. This activity is stereospecific, cytochalasin B-dependent, and is enhanced by extracellular calcium. Pretreatment with leukotriene B4 deactivates rabbit neutrophils, i.e., cells so treated do not respond to stimulation by an additional bolus of leukotriene B4. In addition, the secretory activity of leukotriene B4 is sharply dependent on the simultaneous presence of cytochalasin B. Rabbit neutrophils therefore exhibit the previously described desensitization to the effect of cytochalasin B. In these and other discussed respects the characteristics of the leukotriene B4-induced degranulation of rabbit neutrophils are strikingly similar to those of the chemotactic factors. These results support the hypothesis that leukotriene B4 mediates, at least in part, the secretory, and possibly other, activities of chemotactic factors.

Animals↗
PubMed1981

In vivo effects of leukotriene B4, C4 and D4. Evidence that changes in blood pressure are mediated by prostaglandins.

Intra-jugular nanomole injections of leukotrienes B4, C4 and D4 (LTB4, LTC4, LTD4) in anesthetized guinea-pigs have been shown to cause dose-dependent increases of the mean arterial blood pressure. While the responses to LTB4 were monophasic, the responses to LTC4 and LTD4 were characterized by a fast (10-50 sec), medium high, first pressor phase followed by a second, longer lasting (3-9 min), more important pressor phase. Like antigen-antibody reactions, leukotrienes induced cardiac effects such as tachycardia and rhythm disturbances as well as respiratory difficulties, convulsions and sometimes death of the animals. The prostaglandin synthesis inhibitor, indomethacin, reduced the pressor response and the tachyarrhythmic effects of LTB4, C4 and D4. These results raise the possibility that leukotrienes produce their hemodynamic effects in guinea-pigs by stimulating the synthesis and release of biologically active derivatives of arachidonic acid.

Animals↗
PubMed1981

Pharmacological activity of leukotrienes A4, B4, C4 and D4 on selected guinea-pig, rat, rabbit and human smooth muscles.

The myotropic activity of leukotrienes A4, B4, C4, D4 and histamine has been evaluated on selected smooth muscle preparations. LTA4, B4, C4 and D4 were several times more potent than histamine on the guinea-pig lung parenchymal strip, while on the guinea-pig trachea, LTB4 was less active. The guinea-pig ileum either in segments or in strips of longitudinal muscles responses well to LTC4, LTD4 and histamine but not to LTA4 and LTB4. Rat and rabbit lung parenchymal strip showed very little sensitivity for leukotrienes whereas human parenchymal strips and bronchi were nearly as sensitive as the guinea-pig lung.

Animals↗
PubMedDate not supplied

Self-report measures as predictors of psychotherapy outcome.

A retrospective clinical study using existing patient records investigated the predictive value of a number of variables. Eighty-three new admissions to a large outpatient clinic completed a battery of eight self-report questionnaires that have been shown to be reliable and have a measure of discriminant validity. The battery consisted of items tapping anxiety, depression, obsessive-compulsive symptoms, phobias, borderline personality disorder, and histrionic, obsessive-compulsive, and paranoid personality styles. Outcome of therapy, which was predominantly dynamically-oriented, was assessed by residual difference scores computed from pre- and posttherapy Global Assessment Scale (GAS) ratings. Only patients attending five or more sessions (N = 37) were considered in the analyses. Patients high on the Anxiety Scale pretherapy showed relatively greater improvement in functioning than those with low initial scores. Patients scoring high on the Histrionic, Paranoid, and Obsessive-Compulsive Personality Scales showed the least relative improvement.

Adult↗
PubMedDate not supplied

Correlates of suicide and violence risk 1: the suicide risk measure.

A measure of suicide risk was developed using items reported to discriminate suicidal patients from controls in various studies. The new self-report scale was administered to 82 outpatients, 157 inpatients, and 83 college students. Using total scores, significant differences were found between the college sample and the two patient samples. The scale also discriminated between patients who reported one or more past suicide attempts and those who reported none. An independent cross-validation showed that half of the items continued to discriminate between patient and control groups. Sensitivity and specificity estimates were also determined. The test does not attempt to predict a specific rare event, i.e., suicide. It attempts to describe the degree to which a given individual reveals a set of characteristics that are similar to a suicide prototype.

Bipolar Disorder↗
PubMedDate not supplied

Psychological mindedness as a predictor of psychotherapy outcome: a preliminary report.

This study investigated the properties of a new measure of psychological mindness (PM). A 45-item self-report questionnaire was administered to consecutive admissions to a large outpatient clinic that provides primarily psychodynamically oriented individual psychotherapy. The PM scores of a sample of 44 of these patients who attended a median of 15 sessions were correlated with several outcome measures obtained from retrospective chart reviews. These measures consisted of the number of sessions attended, discharge ratings, and change scores on a Global Assessment Scale (GAS) and on a symptom checklist. Coefficient alpha for the Psychological Mindedness (PM) Scale indicated high reliability. Total PM score correlated significantly with three of the outcome measures. Twenty of the 45-items were good predictors of one or more outcome measures.

Adaptation, Psychological↗