Search PubMed⌕ Search

Biomedical subjects

R Weizman

Publications and source records attributed to R Weizman.

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

Correlation of suicidal and violent behavior in different diagnostic categories in hospitalized adolescent patients.

OBJECTIVE: To determine the relative importance of aggression and depression in adolescent suicide within different diagnostic categories. METHOD: One hundred sixty-three consecutive admissions to an adolescent psychiatric inpatient unit were assessed using a semistructure diagnostic instrument, the Schedule for Affective Disorders and Schizophrenia for School-Age Children. Scores for depression, suicidal behaviors, and violent behaviors were calculated from this assessment. RESULTS: Anorexia nervosa and conduct disorder patients had the highest suicidal behavior scores. In addition, patients with conduct disorder were significantly more violent than patients with major depressive disorder, and scores on the Violent Behavior Scale correlated with suicidal symptoms but not with depressive symptoms. CONCLUSION: Aggression may be as important in some kinds of suicidal behaviors as is depression. Thus it seems that there are hypothetically at least two types of suicidal behaviors during adolescence: a wish to die (depression) and a wish not to be here for a time (impulse control). The first type of suicidal behavior characterizes that seen in disorders with prominent depression such as major depressive disorder and anorexia nervosa, and the second characterizes disorders of impulse control such as conduct disorder.

Adolescent↗
PubMed1995

Defense mechanisms in severe adolescent anorexia nervosa.

OBJECTIVE: To compare ego defense mechanisms in adolescents with anorexia nervosa and other major psychiatric disorders, to defenses in healthy adolescents. METHOD: Thirty-seven patients with anorexia nervosa, 30 with major depressive disorder, 20 with obsessive-compulsive disorder, 53 with borderline personality disorder, 60 with schizophrenia, and 81 healthy controls were assessed with Pfeffer's Ego Defense Scale. RESULTS: Regression, denial, projection, repression, introjection, and total defenses were common to all psychiatric patients and distinguished them from normal adolescents. In addition to these defenses, anorectic patients also used intellectualization more frequently than normal adolescents and psychiatric patients. They used sublimation more than other psychiatric patients. Patients with disorders, apart from obsessive-compulsive disorder, that are considered to be often comorbid with anorexia did not have different defense than schizophrenic patients. CONCLUSIONS: Anorectic adolescents overutilize relatively more mature defenses than do psychiatrically ill adolescents, and they overutilize immature defenses compared with normal adolescents. This combination of mature and immature defenses may be related to the uniquely heterogeneous ego functioning seen in anorectic patients, and it may provide insight into the nature of the psychopathology of anorexia nervosa. It also could have important psychotherapeutic and prognostic value.

Adolescent↗
PubMed1995

Case study: emergence of transient compulsive symptoms during treatment with clothiapine.

Serotonergic dysregulation in obsessive-compulsive disorder has been repeatedly demonstrated. Recent reports on the emergence of obsessive-compulsive symptoms in patients treated with clozapine support a hyposerotonergic hypothesis of obsessive-compulsive disorder. The authors report the emergence of de novo compulsive symptoms in a drug-naive 8-year-old schizophrenic child, shortly after the initiation of treatment with clothiapine. Clothiapine, an atypical antipsychotic agent, shares with clozapine its strong antiserotonergic properties. It seems that antagonistic activity of atypical neuroleptics at postsynaptic serotonergic receptors might be responsible for the development of iatrogenic obsessive-compulsive symptoms.

Antipsychotic Agents↗
PubMed1994

Effects of chronic prenatal, neonatal and adult exposure to barbiturates on mitochondrial benzodiazepine receptors in mouse testis.

In the present study we investigated the effect of chronic exposure to phenobarbital, administered to mice during the prenatal or neonatal period, as well as to adult mice, on mitochondrial benzodiazepine receptors in the testis. Three modes of treatment were investigated: (1) offspring of pregnant mice receiving food containing 3 g/kg phenobarbital until gestational day 18 were killed at 22 or 50 days of age and assayed for receptor binding (prenatal group); (2) offspring of untreated mice were injected subcutaneously once daily with 50 mg/kg phenobarbital on days 2-21 of age and killed at 22 or 50 days of age (neonatal group); (3) adult mice were injected subcutaneously once daily for 3 weeks with 50 or 100 mg/kg phenobarbital (adult group). Prenatal or neonatal exposure to phenobarbital did not alter the testicular weight in all groups (except for the neonatally exposed group killed at 22 days of age), or the mitochondrial benzodiazepine receptor binding characteristics. However, the maximal number of these receptors in the testes of mice in the adult group receiving 100 mg/kg phenobarbital was significantly increased (42%, P < 0.05), compared to controls. The administration of 50 mg/kg phenobarbital to the adult group also induced an increase (27%, non-significant) in testicular mitochondrial benzodiazepine receptors. Phenobarbital administration did not affect the receptor affinity values or the weight of the testis. It is unclear whether these receptor alterations due to chronic phenobarbital exposure of adult mice reflect functional changes in the testis.

Animals↗
PubMed1994

Cytokine production in major depressed patients before and after clomipramine treatment.

Cytokine production by peripheral blood mononuclear cells (PBMC) was assessed in 10 major depressed patients (5 men and 5 women) before and after 4 weeks of clomipramine treatment and in age- and gender-matched healthy controls. A significant reduction in interleukin-1B (IL-1B), interleukin-2 (IL-2) and interleukin-3-like activity (IL-3-LA) was observed in untreated depressed patients when compared to controls. IL-1B and IL-3-LA synthesis was significantly increased after drug treatment. The suppression of cytokine production by PBMC in depressed patients may be attributed to the depression per se, or it may be related to depression-associated hyperactivity of the hypothalamic-pituitary-adrenal axis. The mode of interaction between depression and cellular immune function and the mediators responsible for the reduced cytokine production need to be studied further.

Adult↗
PubMed1994

[3H]GBR 12935 binding to human platelet membranes is sensitive to piperazine derivatives but not to dopamine uptake inhibitors.

It remains controversial whether blood platelet can be used as a peripheral model for the central presynaptic dopaminergic neurons. We investigated the existence of dopamine transport complex in human blood platelet membranes using the selective dopamine uptake inhibitor [3H]GBR 12935 as a radioligand. In contrast to [3H]GBR 12935 binding to rat striatal dopamine carrier site, the high affinity [3H]GBR 12935 binding to platelet membranes was insensitive to mazindol and other dopamine uptake inhibitors. Piperazine derivatives including GBR 12909 were found to be potent inhibitors of [3H]GBR 12935 binding to platelet membranes. [3H]GBR 12935, piperazine derivative-sensitive binding to platelet membranes was inhibited by increasing sodium concentration. Kinetic experiments revealed that both association and dissociation rates of [3H]GBR 12935 binding were slower to platelet membranes than to striatal membranes. These results indicate that [3H]GBR 12935 binding to platelet membranes is different from the binding of this ligand to the dopamine uptake complex and seems to label a "piperazine acceptor" site which was previously demonstrated in brain and liver membranes.

Animals↗
PubMed1994

Impact of the Gulf War on the anxiety, cortisol, and growth hormone levels of Israeli civilians.

OBJECTIVE: The authors investigated the impact of continuous and repeated stress on Israeli civilians exposed to missile attacks during the Gulf War. METHOD: Study 1 included 26 healthy volunteers aged 28-59 years. Their scores on the Hamilton Anxiety Rating Scale and levels of plasma cortisol and growth hormone (GH) were evaluated before, during, and after the war. Study 2 included 13 healthy volunteers aged 25-59 years. Their scores on the state portion of the State-Trait Anxiety Inventory and levels of cortisol and GH were measured three times daily (8:00 a.m., noon, and 6:00 p.m.) at two time points (during and after the war). RESULTS: Anxiety levels of civilians exposed to the threat of war and later to actual missile attacks were significantly higher before and during the war than afterward. Anxiety during the war reached a peak in the evening. The increase in anxiety was not accompanied by any change from basal morning cortisol and GH levels or by diurnal variations in these hormones. CONCLUSIONS: Anxiety levels during the war were similar to those 1 day before its onset, which can be explained by the nature of coping processes. During the war, anxiety levels were highest in the evening, reflecting the war routine (missile attacks occurred mostly at night). The unaltered hormone levels and their normal diurnal variations despite the subjects' persistent anxiety were probably due to adaptation of the hypothalamic-pituitary-adrenal and hypothalamic-somatotropin axes to continuous stress.

Adult↗
PubMed1994

Alteration of platelet benzodiazepine receptors by stress of war.

Mitochondrial benzodiazepine receptors play a major role in steroidogenesis. The authors determined plasma cortisol levels, platelet levels of mitochondrial benzodiazepine receptors, and anxiety and depression scores in 11 civilians exposed to the Persian Gulf war. The density of mitochondrial benzodiazepine receptors was 22% and 15% lower before and during the war, respectively, than 4 weeks after the end of the war. Relief of stress led to an increase in receptors, which correlated with the improvement in anxiety but not mood.

Anxiety Disorders↗
PubMed1993

Modulatory effect of antidepressants on peripheral-type benzodiazepine receptors.

The effect of 21 days of imipramine hydrochloride (10 mg/kg) and phenelzine sulfate (10 mg/kg) administration followed by a 7-day period of withdrawal on peripheral-type benzodiazepine receptors was studied in male Sprague-Dawley rats. Both imipramine and phenelzine down-regulated adrenal peripheral-type benzodiazepine receptors (-18% P < 0.05; and -32%, P < 0.01, respectively) and up-regulated hepatic peripheral-type benzodiazepine receptors (+27%, P < 0.05; and +76%, P < 0.0001, respectively), while no alteration was observed in the kidney. Adrenal peripheral-type benzodiazepine receptors decreased further (-30% versus controls) after withdrawal from imipramine, while full restoration to normal values occurred following phenelzine withdrawal. [3H]PK 11195 binding to the liver did not differ significantly from the control values after withdrawal from either drug. The observed changes can be explained as adaptive responses to antidepressant-induced hormonal and cellular alterations.

Adrenal Glands↗
PubMed1993

Interaction between antidepressants and phosphoinositide signal transduction system in human platelets.

The present study was designed to evaluate the inhibitory effect of antidepressants on thrombin-induced phosphoinositide (PI) hydrolysis. Thrombin 5 units/ml induced a 100%-200% increase in platelet inositol phosphates (IPs) formation. This effect was inhibited in a dose-dependent manner by various heterocyclic antidepressants (IC50 40-170 mumol/L) The monoamine oxidase inhibitor, phenelzine, in concentrations up to 500 mumol/L, was devoid of inhibitory activity. The tricyclic antidepressants, (50 mumol/L) inhibited also thrombin-induced platelet aggregation by 32%-47%. No alteration in thrombin-induced IPs formation was detected in recovered major depressed patients (n = 15) maintained on clomipramine (75-150 mg/day). These results indicate that the heterocyclic antidepressants interfere with the thrombin-linked PI-signaling system. However, the inhibitory effect is achieved only in concentrations above the plasma concentrations obtained with therapeutic doses of these agents.

Antidepressive Agents↗
PubMed1993

Repeated swim-stress reduces GABAA receptor alpha subunit mRNAs in the mouse hippocampus.

The effects of brief repeated swim stress on the expression of GABAA receptor alpha 1 subunit mRNAs was investigated in the mouse. Adult male mice were exposed to repeated brief (10 min) swim-stress once daily for 7 or 14 days and the levels of GABAA receptor alpha subunit mRNAs were quantified in the hippocampus 24 h after the last session by Northern analysis. Repeated swim stress for 14 days resulted in a 47.3% +/- 6.5 and 39.8% +/- 7.6 decrease in the levels of the 4.8 kb and 4.4 kb GABAA receptor alpha 1 subunit mRNAs, respectively. While there was a trend toward a reduction in the level of GABAA receptor alpha 1 subunit mRNAs following 7 days of repeated swim stress, the latter did not reach statistical significance. In contrast, no significant alterations in the levels of glutamic acid decarboxylase or beta-actin mRNAs were observed at either time point. The reduction in GABAA receptor alpha 1 subunit mRNAs following repeated swim stress may underlie similar alteration(s) in hippocampal GABAA receptor density previously observed following repeated swim stress.

Actins↗
PubMed1993

The platelet benzodiazepine receptor is unaltered in obsessive-compulsive disorder.

Mitochondrial benzodiazepine receptors (MBR) are sensitive to anxiety and stress. The aim of the present study was to investigate whether platelet MBR are altered in untreated obsessive-compulsive disorder (OCD) patients and whether chronic treatment with clomipramine (CMI) regulates these receptors. MBR were assessed in 13 drug-free OCD patients as compared with 15 healthy controls. Seven of the 13 patients were treated with CMI (200-300 mg/day). The density and affinity of the receptors to their ligand [3H]PK 11195 in OCD patients and controls were not affected by the CMI treatment despite the clinical improvement. It seems that, in contrast to generalized anxiety disorder, OCD is not associated with alterations in platelet benzodiazepine receptors.

Adult↗
PubMed1993

Cytokine production in anorexia nervosa.

The capacity of peripheral blood mononuclear cells (PBMCs) of anorexia nervosa (AN) patients to produce interleukin-1 (IL-1), interleukin-2 (IL-2), and interleukin-3-like activity (IL-3-LA) was studied. A significantly lower (-49%, p < 0.005) capacity to synthesize IL-2 and an almost significantly impaired ability (-35%, p = 0.058) to release IL-3-LA by PBMCs of AN patients was found, as compared with cells of the control group. IL-1 production, either spontaneous or after stimulation with lipopolysaccharide (LPS), did not differ significantly between AN patients and healthy subjects. The lessened capacity to produce IL-2 was accompanied by an enhanced stimulatory activity of the patient sera on the production of this cytokine by PBMCs of healthy subjects. It is therefore suggested that the serum of AN patients contains a stimulatory factor or factors for cytokine production that compensates for the lower production of cytokines by AN PBMCs. Such a compensatory mechanism may explain why AN patients do not have an higher susceptibility to infections.

Adolescent↗
PubMed1993

Molecular cellular and behavioral aspects of peripheral-type benzodiazepine receptors.

Peripheral-type benzodiazepine receptors (PBR) are prominent in peripheral organs, whereas in the brain, they are sparse and located mainly in glial cells. The PBR bind with high affinity the ligands Ro 5-4864 (4'-chlorodiazepam) and PK 11195 (an isoquinoline carboxamide derivative), but not clonazepam, which binds with high affinity to central-type benzodiazepine receptors (CBR). Subcellularly, PBR are predominantly localized on the outer mitochondrial membrane. It appears that the PBR are composed of three subunits: an 18-kDa subunit that binds isoquinoline carboxamide derivatives; a 30-kDa subunit that binds benzodiazepines; and a 32-kDa subunit labeled by the benzodiazepine [3H]AHN 086, the voltage-dependent anion channel. Recently, complementary DNA (cDNA) encoding for rat and human PBR was isolated and sequenced. The PBR gene is located in the q13.3 region of the long arm of human chromosome 22. The PBR play a major role in steroidogenesis, controlling cholesterol mitochondrial transport. Diazepam-binding inhibitor and its processing products, as well as porphyrins, have been suggested as putative endogenous ligands for these receptors. The PBR ligands have been shown to control cell proliferation and differentiation, and the binding capacity for these ligands is enhanced in some malignant tumors. Stress has been demonstrated to affect PBR bidirectionally. Acute stress is associated with increased PBR density, whereas chronic stress down-regulates PBR.

Animals↗
PubMed1993

The Ganser syndrome in two adolescent brothers.

The Ganser syndrome is rare in children and adolescents. Two cases of Ganser syndrome in adolescent brothers, both of whom developed the syndrome while in jail and awaiting trial, are presented. Both brothers subsequently developed signs and symptoms indicative of affective disorder. The differential diagnosis and the management of these two patients are discussed in the light of the nosological controversies surrounding this clinical entity.

Adolescent↗
PubMed1992

Chronic ethanol consumption and withdrawal affects mitochondrial benzodiazepine receptors in rat brain and peripheral organs.

Ethanol administration to rats for 30 days resulted in a significant decrease (-28%; P < 0.05) in the density of mitochondrial benzodiazepine receptors (MBR) in the olfactory bulb. The reduction in [3H]PK 11195 binding persisted 24 hr after cessation of alcohol and had returned to normal values when measured 4 days later. Alterations were confined to this brain region and were not detected in the cerebral cortex, cerebellum or hippocampus. [3H]PK 11195 binding was elevated in the liver (100%; P < 0.01), heart (43%; P < 0.01) and testis (27%; P < 0.05) 30 days following ethanol consumption and this persisted for 1 and 4 days after abrupt withdrawal. A transitory decrease (-20%; P < 0.05) in MBR density was observed in the adrenal gland following 30 days of alcohol ingestion, but disappeared during withdrawal. The alterations in these receptors may be relevant to the cellular damage or dysfunction induced by chronic exposure to ethanol.

Alcohol Drinking↗
PubMed1992

Platelet imipramine binding and plasma cortisol levels in Israeli civilians during the Gulf War.

[3H] Imipramine binding to platelets and plasma cortisol levels were measured in nine Israeli civilians before, during, and after repeated missile attacks. Hamilton Anxiety Rating Scale (HARS), and Beck Depression Inventory (BDI) were similar before and during the war and decreased significantly after the war. A trend toward increase in platelet imipramine binding values was observed during the war when compared with the postwar values (19%; p = 0.056), and/or when compared with prewar values (26%; p = 0.063). However, one-way analysis of variance with repeated measures did not reveal a significant statistical difference [F (2,6) = p = 2.07; NS] among the three time points. A significant correlation was found between HARS score, but not BDI, and imipramine binding values in the prewar and postwar time points (r = 0.87; 0.71, respectively). Plasma cortisol levels did not alter significantly during the study period.

Adjustment Disorders↗