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Biomedical subjects

R Weizman

Publications and source records attributed to R Weizman.

At least 55 records · Page 3Linked to original sources
PubMed1997

Israeli preschool children under Scuds: a 30-month follow-up.

OBJECTIVE: Longitudinal studies of children exposed to traumatic events show contrasting findings regarding their symptomatic change over time. The present study reports on a 30-month follow-up of preschool children and their mothers who had been exposed to Scud missile attacks. METHOD: Families displaced during the Gulf War after their homes had been damaged by the missile attack and a control group whose homes remained intact were interviewed about posttraumatic and general symptomatology, the mothers' capacity to control images, and the children's adaptive behavior. RESULTS: Stress symptoms decreased in the displaced children but not in their mothers. Both reported more posttraumatic symptoms than did the control group. No differences in the children's adaptive behavior were observed. Posttraumatic symptoms of the displaced children correlated with the mothers' avoidant symptoms. The mothers' avoidant symptoms at follow-up were statistically explained by the mothers' symptoms during the war and their capacity for image control, the duration of displacement, and the cohesion of the family. CONCLUSIONS: The maternal stress-buffering capacity constitutes a central element in children's protective matrix and is crucial in minimizing long-term internal suffering of traumatized preschool children.

Adaptation, Psychological↗
PubMed1996

Cytokine production in obsessive-compulsive disorder.

Cytokine production was previously demonstrated to be reduced in untreated major affective patients. In addition, recovery from depression following clomipramine (CMI) treatment was accompanied by the restoration of interleukin-1 beta (IL-1 beta) and interleukin-3-like activity (IL-3-LA) to normal range. In the present study we assessed the in vitro production of IL-1 beta IL-2, and IL-3-LA by peripheral blood mononuclear cells (PBMC) in 11 nondepressed patients with obsessive compulsive disorder (OCD) before and after 8 weeks of CMI treatment. Results were compared with those of 11 healthy subjects. CMI treatment induced a significant improvement in OCD symptoms. No alteration was observed in cytokine production in OCD patients before treatment as compared to control subjects. Moreover, 8 weeks of drug treatment had no effect on cytokine production. In conclusion, OCD per se, as well as CMI treatment, have no effect on interleukin production as measured in this study.

Adult↗
PubMed1996

Platelet imipramine binding in patients with posttraumatic stress disorder before and after phenelzine treatment.

Posttraumatic stress disorder (PTSD) is frequently associated with major depressive disorder, and antidepressants have been reported to ameliorate PTSD symptoms in some patients. The present study assessed the number and affinity of platelet imipramine binding sites, as a marker of the serotonin transporter complex, in PTSD male patients (n = 10) before and after phenelzine treatment (30-60 mg/day, for 4 weeks) as well as in comparison to healthy controls (n = 10). In our sample, there was no evidence of a significant difference in the characteristics (Bmax and Kd) of platelet [3H]imipramine binding between the PTSD patients and the controls and within PTSD patients before and after phenelzine treatment. Moreover, no beneficial effect of phenelzine was detected in the patients (as assessed by PTSD, anxiety, and depression scales).

Adult↗
PubMed1996

Serum triiodothyronine elevation with posttraumatic stress disorder: a cross-cultural study.

This study examines the thyroid hormonal profile in Israeli combat veterans with posttraumatic stress disorder (PTSD) and compares it with the previously reported profile in American Vietnam combat veterans with PTSD. Eleven male combat veterans with PTSD were compared with 11 normal subjects. Thyroid junction was evaluated by the measurement of serum total triiodothyronine (TT3), free triiodothyronine (FT3), total thyroxine (TT4), free thyroxine (FT4), thyroxine-binding globulin (TBG), and thyroid-stimulating hormone (TSH). The mean total T3 level in the Israeli PTSD patients (160.5 ng/dL) was significantly elevated (t = 2.53, p < .02) above that of the comparison group (135.5 ng/dL). Total T3 mean levels were not significantly different between the Israeli PTSD group and two American PTSD groups, but all three PTSD groups had significantly higher total T3 levels than both Israeli and American comparison groups. This preliminary study indicates that T3 elevation in combat-related PTSD may extend across cultures and suggests that further comparison of Israeli and American PTSD and normal groups may be useful in evaluating the significance and implications of the unusual alterations in the thyroid system in PTSD.

Adult↗
PubMed1996

Modulatory effect of agents active in the presynaptic dopaminergic system on the striatal dopamine transporter.

We have investigated the effects of agents active in the presynaptic dopaminergic system on the characterization of the rat striatal dopamine transporter. The dopamine transporter was characterized by high-affinity [3H]GBR 12935 (1-[2-diphenylmethoxy)-ethyl]-4-(3-phenylpropyl)-piperazine) binding to a membrane preparation and by [3H]dopamine uptake into striatal synaptosomes. Subchronic treatment with reserpine (2.5 mg/kg, 4 days), a monoamine depletor, caused a significant decrease in both [3H]GBR 12935 binding (20%) and [3H]dopamine uptake (51%). In contrast, amantadine (a dopamine releaser) treatment (20 mg/kg, 21 days) induced an increase (28%) in the maximal number of [3H]GBR 12935 sites. Chronic levo-dopa (dopamine precursor) treatment combined with carbidopa (50 mg/kg and 5 mg/kg respectively, 21 days) as well as benztropine (dopamine uptake inhibitor) treatment (10 mg/kg, 21 days) did not affect the striatal dopamine transporter characteristics. The present results showed that the striatal dopamine transporter is sensitive to changes in dopaminergic neurotransmission caused by agents that do not interact directly with the dopamine carrier.

Amantadine↗
PubMed1996

Israeli preschoolers under Scud missile attacks. A developmental perspective on risk-modifying factors.

BACKGROUND: The devastating effects of traumatic events on children are modulated by risk and protective factors. This study examines the differential effects of traumatic displacement of preschool children and their families following Scud missile attacks on Israel during the Persian Gulf War. METHODS: Three groups participated in the study: families displaced after their houses were damaged, undisplaced families from the same neighborhood (without home damage), and families from a distant city that was threatened but not directly attacked. Data concerning the traumatic event, the child (personality, internalizing, externalizing, and stress symptoms), the mother (Symptom Checklist-90-Revised), and the family (Family Adaptability and Cohesion Evaluation Scales) were gathered 6 months after the end of the war. RESULTS: Displaced children and mothers showed higher externalizing and stress symptom levels compared with undisplaced and threatened subjects. Destruction of the house and displacement, but not mere distance from the missile impact, explained symptomatic behavior. Inadequate family cohesion predicted symptomatic reaction for 3- and 4-year-old children but not for older ones. CONCLUSION: Both human and nonhuman factors contribute to the preschool child's adaptive mechanisms that regulate environmental stressful stimuli. These risk-modifying factors become more autonomous of caretakers with increasing age.

Adaptation, Psychological↗
PubMed1996

Neural network based on adaptive resonance theory as compared to experts in suggesting treatment for schizophrenic and unipolar depressed in-patients.

A modified neural network based on adaptive resonance theory (ART) was trained with the records of 211 psychiatric inpatients (74 schizophrenic, 50 unipolar depressed, 34 bipolar depressed, 20 bipolar manic, 33 other) who improved by at least 40 points on the GAFS during 8 weeks of treatment. Thereafter, a comparison was made between the clinical response of another 26 schizophrenic patients and 28 unipolar depressed inpatients, to treatment suggested by the trained ART (N = 21) and by the consensus of two senior psychiatrists (N = 33). The patients were allocated blindly and randomly to the two treatment groups. The BPRS (for the schizophrenic patients) or the HDRS (for the unipolar depressed patients) was completed weekly for 5 weeks. Results showed no difference between decisions regarding treatment by the ART network and by the experts. Length of hospital stay was also similar. All ART suggestions included supportive psychotherapy. High potency antipsychotics were suggested for 7 schizophrenic inpatients, clozapine for one and the addition of community therapy for another. Depressed patients got a variety of treatment suggestions. No contraindicated treatment was suggested by ART; however, two incomplete treatment suggestions were dropped from the study. In conclusion, in a prospective study ART was successful in learning treatment strategies and performed under supervision similar to experts.

Adolescent↗
PubMed1996

Effect of the neuroactive steroid alpha-THDOC on staircase test behavior in mice.

This study examined the effect of the neuroactive steroid 3 alpha, 5 alpha-tetrahydrodeoxycorticosterone (alpha-THDOC) as compared to the benzodiazepines diazepam and midazolam and the barbiturate phenobarbital on the number of rearing events and the number of steps ascended in the mouse staircase test. The benzodiazepines, phenobarbital and alpha-THDOC all reduced rearing activity at doses that did not affect climbing. The rearing-suppression effect of the benzodiazepines and alpha-THDOC, but not of phenobarbital, was blocked by the benzodiazepine antagonist flumazenil. It appears that, although such neuroactive steroids, like barbiturates, bind to distinct sites within the chloride ion channel of the gamma-aminobutyric acid type A (GABAA) receptor complex, alpha-THDOC behavioral activity is modulated by the benzodiazepine recognition site.

Animals↗
PubMed1996

Altered platelet peripheral-type benzodiazepine receptor in posttraumatic stress disorder.

Peripheral-type benzodiazephine receptors (PBR) are involved in steroidogenesis and are sensitive to stress. Reduced platelet PBR density has been demonstrated in generalized anxiety disorder (GAD), but not in obsessive-compulsive disorder (OCD). We extended this observation to another anxiety disorder, namely, posttraumatic stress disorder (PTSD). Eighteen post-Persian Gulf War PTSD patients and 17 age- and sex-matched controls were included in the study. All subjects were evaluated using the Structured Clinical Interview for DSM-III-R-Patient Version. The severity of symptoms was assessed using the DSM-III-R scale for PTSD, the Impact of Event Scale, the Beck Depression Inventory, and the State-Trait Anxiety Inventory. [3H]PK 11195 was used to label platelet PBR. All psychological parameters (except trait anxiety) were higher in PTSD patients compared to controls. Decreased platelet PBR density (-62%; p < .001) was observed in the PTSD patients compared to controls. The reduction in PBR observed in PTSD patients was in accordance with the findings in GAD patients, but differed from those obtained in OCD patients. It is possible that the receptoral downregulation is an adaptive response aimed at preventing chronic overproduction of glucocorticoids in hyperarousal states.

Adult↗
PubMed1996

PK 11195 aggravates 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced hepatic porphyria in rats.

There is evidence to suggest that peripheral-type benzodiazepine receptors (PBR) are involved in porphyrin transport during erythroid differentiation, and it is possible that these receptors have an important role in heme biosynthesis. We examined the biochemical and ultrastructural alterations in rat liver following experimentally induced acute hepatic porphyria, as well as the effects of the administration of a selective PBR ligand, PK 11195. The most severe pathological conditions were found in rats that received a combined treatment of the porphyrinogenic agent 3,5-diethoxycarbonyl-1,4- dihydrocollidine (DDC) and PK 11195. Transmission electron microscopy showed a correlation between the ultrastructural pathology of the liver, the total porphyrin levels in urine and liver, and the porphobilinogen levels in urine. Hepatocytes in this acute porphyria showed the development of large secondary lysosomes containing crystalline aggregates of protoporphyrin. Bile canaliculi were grossly enlarged, contained aggregates of protoporphyrin crystals, and showed the presence of bile thrombi. In addition, prominent bundles of collagen fibers (fibrosis) were commonly found in livers of rats that had been treated with DDC or DDC and PK 11195. We conclude that the administration of PK 11195 to porphyric rats aggravates porphyrin accumulation and cellular damage in the liver. Perhaps this evidence suggests that PK 11195 blocks the binding of protoporphyrin IX to PBR, thus elevating the content of protoporphyrin IX in liver.

Animals↗
PubMed1996

State and trait anxiety in adolescent suicide attempters.

OBJECTIVE: To examine the relationship between anxiety and suicidal behavior in adolescents. METHOD: Forty-six adolescents who had been hospitalized in an inpatient psychiatric unit after a suicide attempt were compared on measures of anxiety and depression with 72 adolescent psychiatric inpatients who had no history of suicide attempts. RESULTS: The suicide attempters exhibited significantly higher levels of both state and trait anxiety. However, when controlling for depression, the attempters did not differ in their level of state anxiety from the nonattempters, but they still manifested significantly higher levels of trait anxiety than nonattempters. CONCLUSIONS: The results suggest that anxiety, both state and trait, is a risk factor for suicidal behavior in adolescents. Yet, only trait anxiety appears to be relatively independent of depression in its effect on suicidal behavior risk. These findings imply that clinicans should take into account anxiety, both state and trait, for assessment and treatment of adolescents at risk for suicidal behavior.

Adolescent↗
PubMed1996

Repeated swim stress and peripheral-type benzodiazepine receptors.

The effect of daily forced swimming (15 min) of rats for 21 consecutive days on peripheral-type bentodiazepine receptors (PBR) was investigated. A significant reduction (-17%; p < 0.05) was observed in renal PBR in the stressed animals. A nonsignificant reduction of -18% was detected in adrenal PBR. The maximal binding capacity of [3H]PK 11195 was unaltered in the liver, heart, testis and thymus. It seems that the kidney is especially sensitive to repeated stress. The renal PBR reduction may be related to habituation to stress, and may reflect an adaptatory mechanism aimed at preventing long-term stress-induced overactivity of the renin-angiotensin system.

Animals↗
PubMed1996

T cell subsets in obsessive-compulsive disorder.

Stress can produce immunosuppression leading to increased susceptibility to infection, tumor growth or autoimmune disease. It has been recently noted, however, that certain kinds of stress need not increase the risk of immune pathology. The present study looked for immune pathology in an anxiety-related disorder. Acute exacerbation of obsessive-compulsive disorder (OCD), an anxiety spectrum disorder, served as a model for stress. Seven OCD subjects in acute exacerbation, and 9 healthy age-matched control subjects participated in the study. T cell subsets were determined at baseline in both OCD and control groups, and after 6 weeks on clomipramine in the OCD group. No statistically significant changes in lymphocyte subsets were found between the control and the untreated patient groups. Likewise, no statistically significant changes were found in patients before and after treatment. The negative findings of the present study supports the view that stress need not compromise immunologic function. Various aspects of stress, which may turn the immune system vulnerable, are discussed as well.

Adult↗
PubMed1995

Down-regulation of hepatic peripheral-type benzodiazepine receptors caused by acute lead intoxication.

In the present study we investigated the influence of acute lead poisoning upon the expression of benzodiazepine receptors. In addition, we examined if administration of PK 11195, an isoquinoline carboxamide derivative, to lead-poisoned rats could modulate the changes in receptor binding properties achieved by lead alone. Lead poisoning was ascertained by determination of urine delta-aminolevulinic acid levels and lead levels in rat livers. Scatchard analysis of saturation curves of [3H]PK 11195 binding to liver membranes of rats treated with lead alone or with both lead and PK 11195 showed and approximately two-fold decrease in receptor density in comparison with control groups. Peripheral benzodiazepine receptor density in kidneys and adrenals of poisoned rats was not changed by lead intoxication per se or by coadministration of PK 11195. Scatchard analysis of saturation curves of [3H]Ro 15-1788 binding in rat cerebral cortex tissue showed no difference in the receptor density between the various groups. The Kd values of all organs were in the nanomolar range (1-4 nM). We conclude that PK 11195 is not a protective agent of hepatic peripheral benzodiazepine receptors in lead intoxication. Moreover, it causes over-accumulation of lead in hepatocytes in an unknown mechanism of action.

Adrenal Glands↗
PubMed1995

Developmental and age-related alterations in rat brain presynaptic dopaminergic mechanisms.

Age-related changes in both pre- and post-synaptic components of dopamine neurons have been demonstrated in humans as well as in animals. Our study was designed to examine the effects of age on presynaptic DA neurons. To assess the developmental changes in rat striatal dopamine carrier, we used [3H]GBR 12935, which binds selectively to this transporter. In addition we monitored changes in amphetamine- and KCl-induced [3H]DA release from rat striatal slices. We were able to demonstrate age dependent changes in DA transporter density, which reached a peak at age 3 months. Amphetamine-induced released of stored DA was exactly reversed, with a nadir at age 3 months. We assumed that the combination of low DA transporter level with increased transporter-mediated DA release may have a major compensatory role with respect to the maintenance of dopaminergic transmission during normal development, aging and neuro-degenerative diseases.

Age Factors↗
PubMed1995

[3H]GBR 12935 labels mainly the piperazine acceptor site in the rat prefrontal cortex.

The binding characteristics of [3H]GBR 12935, a ligand for the dopamine (DA) transporter, have been extensively investigated in the striatum. The present study was designed to characterize [3H]GBR 12935-binding to prefrontal cortex (PFC) in rats. This region receives a dense DA input from the ventral tegmental area and is suspected to play a major role in higher associative functions. We demonstrated high-affinity, saturable, mazindol-sensitive [3H]GBR 12935-binding in the rat PFC; however, in contrast to the striatum, such binding was inhibited by increasing concentrations of Na+. This fact, together with the irregular pattern of the association kinetics and the marked sensitivity of [3H]GBR 12935-binding to piperazine derivatives, indicates the possible presence of more than one [3H]GBR 12935-binding site in the PFC. Furthermore, it appears that [3H] 12935 in the rat PFC labels mainly 'the piperazine acceptor site' and not the DA transporter.

Animals↗