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Biomedical subjects

A Weizman

Publications and source records attributed to A Weizman.

At least 91 records · Page 5Linked to original sources
PubMed2000

Hemispheric function in disorganized type schizophrenia: performance on the quality extinction test.

We assessed hemisphere function in right-handed male chronic, disorganized type schizophrenic patients (N = 60, age range 18-45 years) using the Quality Extinction Test (QET), in comparison to 20 right-handed male healthy controls in the same age range. The QET analysis discriminated between the disorganized schizophrenic patients and the controls. QET results indicated that chronic schizophrenic patients were less sensitive to tactile stimuli in both hands as compared to controls. Furthermore, the sensitivity to tactile stimuli of the left hand was less than that of the right hand in the schizophrenic patients. In contrast, in the normal controls the sensitivity was similar in both hands. These results indicate possible right hemisphere dysfunction together with disturbance in interhemispheric transmission through the corpus callosum in chronic, disorganized type schizophrenic patients.

Adolescent↗
PubMed2000

Actigraphic monitoring (actigraphy) of circadian locomotor activity in schizophrenic patients with acute neuroleptic-induced akathisia.

BACKGROUND: Actigraphy is a quantitative method for measurement of motor activity. In the present study we used actigraphy to examine diurnal variations in locomotor activity of schizophrenic patients with neuroleptic-induced akathisia (NIA). METHOD: Thirty-two schizophrenic patients, 16 with NIA and 16 without (DSM-IV criteria) underwent 24-h actigraphic monitoring. Clinical assessments of NIA were conducted with Barnes Akathisia Scale (BAS) at 08:00, 12:00, 16:00 and 20:00. Sleep parameters (duration, latency, continuity and efficacy) were assessed by actigraphy. Sleep quality was evaluated by a self-rated sleep questionnaire. RESULTS: NIA patients demonstrated persistent higher daytime motor activity from 11:30 to 14:15 and from 18:00 to 21:00 than controls. There were no differences between the groups in nighttime motor activity, confirming clinical observations that NIA tends to disappear during sleep. Subject's sleep assessments were similar in the two groups. CONCLUSIONS: Actigraphy seems to be a reliable, non-invasive, method of measuring motor activity in patients with NIA. Its sensitivity and specificity as an objective quantitative diagnostic instrument in patients with NIA merits further investigation.

Adult↗
PubMed2000

Suppression of serum gonadal steroids in rats by chronic treatment with dopamine and serotonin reuptake inhibitors.

The impact of chronic administration (3 weeks) of dopamine and serotonin reuptake inhibitors on serum gonadal steroid hormones and prolactin was studied in intact male and female rats. Both the dopamine and the serotonin reuptake inhibitors lowered serum estradiol and progesterone levels in the female rats. The dopamine transporter blockers suppressed testosterone serum levels in the male rats, whereas serotonin reuptake inhibitors induced only a non-significant reduction (30%) of this hormone. In contrast to the decrease in gonadal steroids, none of the serotonin or the dopamine reuptake blockers altered prolactin serum levels in either the male or female rats. It seems that the effect of these agents on ovarian and testicular hormones is related to the impact of the monoamine reuptake inhibitors on the hypothalamic-pituitary-gonadal axis.

Animals↗
PubMed2000

Unaltered alpha(2)-noradrenergic/imidazoline receptors in suicide victims: a postmortem brain autoradiographic analysis.

In vitro quantitative autoradiography of alpha(2)-adrenergic/imidazoline receptors, using [(125)I]iodoclonidine as a ligand, was performed on 24 human brains postmortem. Twelve brains were obtained from suicide victims and 12 from matched controls. We found no significant, region-dependent alterations in the density of alpha(2)-adrenergic receptors in brains of suicide victims as compared to matched controls. We also report age-dependent reductions in binding in the prefrontal cortex and hippocampus, as well as significant recent alcohol ingestion-dependent reductions in binding in the prefrontal cortex. Sex and time from death to autopsy did not affect iodoclonidine binding in our sample.

Adolescent↗
PubMed2000

Evidence for the involvement of the hippocampus in the pathophysiology of schizophrenia.

The hippocampus, a medial temporal lobe structure, is often considered to play an important role in the pathophysiology of schizophrenia. Recent developments of neuroimaging and molecular postmortem techniques have significantly increased our ability to study the role of discrete brain regions in the pathophysiology of schizophrenia. This article describes animal models, structural, histological, molecular biology, and neuropsychological evidence for the involvement of the hippocampus in the pathophysiology of schizophrenia. The major findings in schizophrenic patients are decreased volumes, hypometabolism, and cytoarchitectural abnormalities which are more robust on the left hippocampus, as well as verbal memory impairment. It is yet to be determined whether these changes are neurodevelopmental or neurodegenerative in nature. Overall, these findings indicate that there are subtle changes in the hippocampus of schizophrenic patients. More comprehensive and focused hippocampal research in schizophrenia is required to elucidate the contribution of this intriguing brain structure to the pathophysiology of schizophrenia.

Animals↗
PubMed2000

Acute antipsychotic drug administration lowers body temperature in drug-free male schizophrenic patients.

We examined, in a controlled design, potential alterations in body temperature of male schizophrenic patients following acute antipsychotic drug (APD) administration. Fourteen drug-free (study group) and seven schizophrenic patients maintained on APDs (comparison group) initiated or received higher dose of their APD, respectively, for 27 days. Initial body temperature was 0.36 degrees C higher in the study group (P=0.01) and decreased within 24 h to values comparable to that of the comparison group (all within normal range).

Adolescent↗
PubMed2000

Elevated circulatory level of GABA(A)--antagonistic neurosteroids in patients with combat-related post-traumatic stress disorder.

BACKGROUND: Post-traumatic stress disorder (PTSD) is a multisystem neurobiological disorder with chronic alterations in various neurochemical systems. Levels of the GABA(A)--antagonistic neurosteroids plasma dehydroepiandrosterone (DHEA) and its sulphate derivate, dehydroepiandrosterone sulphate (DHEAS) may be relevant to depressive and anxiety disorders, including PTSD. METHODS: We assessed the circulatory levels of morning plasma DHEA and DHEAS in 21 male outpatients with untreated chronic combat-related PTSD (CR-PTSD), and 18 healthy control male subjects. RESULTS: Compared with the control subjects, the PTSD patients showed significantly higher plasma DHEA and DHEAS levels. CONCLUSIONS: Chronic CR-PTSD may be associated with increased circulatory level of neuroactive steroids with inhibitory activity at the GABA(A) receptors. Neurosteroid-induced decreased GABAergic tone may be relevant to the symptomatology and pathophysiology of chronic PTSD, as well as to the frequent co-morbidity of PTSD with depression and anxiety disorders.

Adult↗
PubMed2000

Treating depression in Alzheimer's disease: integration of differing guidelines.

BACKGROUND: The developments in the understanding of Alzheimer's disease (AD) have led to genetic testing, expansion of research centers, and emergence of novel treatment modalities. However, behavioral symptoms and disturbances remain the leading cause of distress to families and patients. The management of these disturbances is not fully elucidated and not without controversies. AIM: To review and integrate the two important approaches to management and treatment of depression in AD as published in the American Psychiatric Association's guidelines for the treatment of patients with AD versus the American Academy of Neurology's official publication on managing AD. METHOD: Both publications are analyzed focusing on the pharmacological treatment of depression. The analysis includes sources of data, generalization, and common and conflicting recommendations. CONCLUSION: Selective serotonin reuptake inhibitors are the drugs of choice for the treatment of depression in AD patients.

Aged↗
PubMed2000

Attachment styles in maltreated children: a comparative study.

The study compares the emotional impact of maltreatment on the attachment styles in three groups of children aged 6-12 years: children of drug-user fathers (n = 76), physically abused children (n = 41), neglected children (n = 38); non-abused/non-neglected children (n = 35)--control group. The secure style characterized 52% of the children of drug-user fathers and the insecure style characterized the other 48% (anxious/ambivalent or avoidant); physically abused children were characterized mainly by the avoidant attachment style, and neglected children by the anxious/ambivalent style. The conclusion is that physically abused children are at risk of antisocial behavior and sustained suspicion towards others; neglected children are at risk of social withdrawal, social rejection and feelings of incompetence, and children of drug-user fathers may be at risk of behavioral problems and drug use in adolescence.

Child↗
PubMed2000

Prospective evaluation of circulatory levels of catecholamines and serotonin in neuroleptic malignant syndrome.

OBJECTIVE: Neuroleptic malignant syndrome (NMS) may be associated with a dysregulation of the catecholaminergic and serotonergic systems. The objective of the present study was to evaluate prospectively the circulatory levels of serotonin (5-HT), epinephrine (E) and dopa in patients suffering from NMS. METHOD: Platelet-poor plasma (PPP) levels of serotonin, epinephrine and dopa in eight NMS patients were measured twice: in the acute state and in the state of remission. RESULTS: PPP dopa concentration was significantly lower in acute NMS state compared to the remission state (P = 0.023). In contrast, PPP E level was significantly higher (P = 0.019) in the acute NMS state and PPP 5-HT concentrations in the acute state tended to be higher than those at remission (P = 0.078). 5-HT/dopa ratio was significantly higher in the acute NMS (P = 0.015). CONCLUSION: These results may reflect reduction in dopaminergic function and increase in adrenergic and serotonergic activity in the acute NMS state.

Acute Disease↗
PubMed2000

The wired network as a learning paradigm for normal and abnormal brain neuronal communication.

The brain is a highly sophisticated assembly of neuronal networks for interaction with the internal and external environment. Fundamentally, the neuronal communication process is analogous structurally and functionally to the electrical (wire-mediated) network. In particular, both have coupled information-processing and conduction properties. We suggest that the electrical system can be used as a learning paradigm in brain research and clinical practice. Our model shows how the study of wire-mediated networks may be of benefit in tracing overt psychiatric manifestations to intrinsic biological faults in brain circuitry.

Brain↗
PubMed2000

Homeostatic biophasal conscious regulation.

A new theory on consciousness is presented. According to our neuroscientific model, focal awareness is the result of neurophysiological patterns of voluntary or involuntary information, registration, storage and retrieval performed in accordance with organismic biphasal homeostatic rules and regulations that follow the demand-supply principle. The information-processing operation consists of three major elements: 1. Involuntary activated 'inherited schematic representation' (ISR) programs that monitor homeostatic negative feedback programs and remain inert during the storage period; 2. Voluntary activated 'acquired engram linkage' (AEL) programs that monitor the preferential self-efforts designed to maintain homeostasis and dynamic adaptational survival; this information remains fixed in the storage reservoir; and 3. Outer, nonselective sources of activation that derive from the assembly of the sensory information system. Consciousness is limited by the microneurostructural boundaries of 'conscious instrument panel' (CIP) needed to handle this unique biological experience. At any unit of time, the conscious subjectively identifies states of pleasure (first phase of homeostasis maintenance) or displeasure (second phase of homeostasis) which are associated with the alarm subsystem of the 'organismic defense system' (ODS).Thus, consciousness is a form of neurophysiological activity that excludes unconscious existence in order to monitor information. This model promotes our understanding of the biological essences of consciousness.

Consciousness↗
PubMed2000

Abnormal neuronal ionic flux activity: learning paradigms of schizophrenic thought disorders.

New developments in biological psychiatry have prompted the development of our pathophysiological theory of the etiology of schizophrenic thought disorders. We suggest that the presence of brain bionic lesions may produce microneuropathies in certain neuronal electrical pathways, leading to abnormal biological communication. These blockages force the rerouting of incoming electric signals through bypass pathways which divert the message from target to non-target neurons for decoding and integration. Using this model, we were able to link specific schizophrenic disturbances to different types of brain bionic lesion effects. This model should be further investigated to facilitate the understanding of the nature and origin of schizophrenic disorders and to stimulate further interest in this fascinating field.

Brain↗
PubMed2000

Human figure drawings in the evaluation of severe adolescent suicidal behavior.

OBJECTIVE: To evaluate the reliability of using certain indicators derived from human figure drawings to distinguish between suicidal and nonsuicidal adolescents. METHOD: Ninety consecutive admissions to an adolescent inpatient unit were assessed. Thirty-nine patients were admitted because of suicidal behavior and 51 for other reasons. All subjects were given the Human Figure Drawing (HFD) test. HFD was evaluated according to the method of Pfeffer and Richman, and the degree of suicidal behavior was rated by the Child Suicide Potential Scale. RESULTS: The internal reliability was satisfactory. HFD indicators correlated significantly with quantitative measures of suicidal behavior; of these indicators specifically, overall impression of the evaluator enabled the prediction of suicidal behavior and the distinction between suicidal and nonsuicidal inpatients (p < .001). A group of graphic indicators derived from a discriminant analysis formed a function, which was able to identify 84.6% of the suicidal and 76.6% of the nonsuicidal adolescents correctly. Many of the items had a regressive quality. CONCLUSIONS: The HFD is an example of a simple projective test that may have empirical reliability. It may be useful for the assessment of severe suicidal behavior in adolescents.

Adolescent↗
PubMed2000

LSD-induced hallucinogen persisting perception disorder treatment with clonidine: an open pilot study.

A pilot open study was conducted in order to evaluate the efficacy of clonidine in the treatment of LSD-induced hallucinogen persisting perception disorder (HPPD). Eight patients fulfilled entrance criteria. All complained of HPPD for at least 3 months and were drug free at least 3 months. They received fixed low doses of clonidine, 0.025 mg, three times a day for 2 months. They were evaluated by the Clinical Global Impression Scale (CGI) and a self-report scale on the severity of symptoms (graded 0-5). Patients scored an average of 5.25 (SD = 0.46) on the CGI and 4 on the self-report scale at baseline, indicating marked psychopathology. One patient dropped out at week 3 and a second patient dropped out at week 5. Of the six patients remaining at the end of 2 months, the average CGI score was 2.5 (SD = 0.55) and the self-report scale score was 2, indicating mild symptomatology. LSD-related flashbacks associated with excessive sympathetic nervous activity may be alleviated with clonidine in some patients.

Adrenergic alpha-Agonists↗
PubMed2000

Beneficial effect of olanzapine in schizophrenic patients with obsessive-compulsive symptoms.

Some studies suggest that obsessive-compulsive symptoms may be common (7.8-46%) in schizophrenic patients and seem to be poorly responsive to drug therapy. Conventional neuroleptics are of limited value, but adjunctive anti-obsessive agents (clomipramine, fluvoxamine) may be an option. Although novel atypical antipsychotics (clozapine, risperidone) reportedly aggravate the obsessive-compulsive symptoms, a recent trial has shown that olanzapine did not induce new-onset obsessive-compulsive symptoms in schizophrenic patients. We report our experience with three schizophrenic patients with obsessive-compulsive symptoms who were unsuccessfully treated with various conventional neuroleptics in combination with anti-obsessive agents and subsequently showed resistance or intolerance to clozapine. All of them were switched to olanzapine (10-20 mg/ day). All patients demonstrated a significant improvement in both schizophrenic and obsessive-compulsive symptoms as measured by the Brief Psychiatric Rating Scale (BPRS) and the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Within 5-8 weeks of initiation of olanzapine, the BPRS scores of the three patient decreased by 53%, 51% and 48%, and the Y-BOCS scores by 68%, 73% and 85%. Olanzapine was well tolerated. These preliminary results suggest that olanzapine may be a therapeutic option in schizophrenic patients with obsessive-compulsive symptoms.

Adult↗
PubMed2000

Search for association between suicide attempt and serotonergic polymorphisms.

Serotonergic neurotransmission has been implicated in suicidal behavior. Polymorphisms in the genes coding for tryptophan hydroxylase, serotonin receptor 2A and serotonin transporter were investigated in a sample of suicide attempters (n = 165) and healthy control subjects (n = 99). No significant differences were found for any of the investigated polymorphisms. Neither did any significant differences emerge in comparison with control subjects when the suicide attempters were grouped into different diagnostic categories: unipolar disorder (n = 45), adjustment disorder (n = 37), substance use disorder (n = 37) and personality disorder, cluster B (n = 36). The results suggest that alleles defined by the investigated polymorphisms do not represent a major determinant in suicide attempt. However, a highly significant (P = 0.001; odds ratio, 1.47; 99% confidence interval, 1.42-1.53) allelic association between tryptophan hydroxylase and suicide attempt is indicated after pooling our data with literature data. In light of previous data, a possible association between the tryptophan hydroxylase polymorphism and a phenotype that may become differently stratified within differently selected samples of suicide attempters is discussed.

Adjustment Disorders↗