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Biomedical subjects

A Weizman

Publications and source records attributed to A Weizman.

At least 55 records · Page 3Linked to original sources
PubMed2001

Abnormal thermoregulation in drug-free male schizophrenia patients.

Schizophrenia patients may develop various thermoregulatory disturbances. We hypothesized that a standardized exercise-heat tolerance test [two 50-min bouts of walking a motor-driven treadmill at 40 degrees C (relative humidity=40%)] would reveal abnormal thermoregulation in drug-free schizophrenia patients. Six drug-free schizophrenia outpatients and seven healthy comparison subjects participated in this study. The schizophrenia patients exhibited significantly higher baseline and exertion-related rectal temperature. The relevance of these findings to the pathophysiology of schizophrenia-related thermoregulatory disorders is as yet unclear.

Adult↗
PubMed2001

Analysis of neurosteroid levels in attention deficit hyperactivity disorder.

Neurosteroids are important neuroactive substrates with demonstrated involvement in several neurophysiological and disease processes. Attention deficit hyperactivity disorder (ADHD) has been associated with dysregulation of the catecholaminergic and serotonergic systems, however its relationship to irregularities or changes in neurosteroid levels remains unknown. We examined the relationship between blood levels of dehydroepiandrosterone (DHEA), its principal precursor pregnenolone and its principal metabolite dehydroepiandrosterone sulphate (DHEAS) in 29 young male subjects aged 7-15 years with DSM-IV criteria of ADHD. Subjects were evaluated by a specially designed scale, following which patients were divided into two groups according to severity of symptomatology. Results indicated significant inverse correlations between clinical symptomatology and levels of DHEA and pregnenolone in the total group. These inverse correlations were particularly evident in the less severe group of subjects. Levels of DHEA and DHEAS were inversely correlated with the hyperactivity subscale. Furthermore, using median blood levels as a cut-off indicator, higher blood levels of DHEA and DHEAS were associated with fewer ADHD symptoms, in particular hyperactivity symptomatology. Our findings suggest a possible protective effect of various neurosteroids on the expression of ADHD symptomatology.

Adolescent↗
PubMed2001

Evaluation of the neurotoxic activity of typical and atypical neuroleptics: relevance to iatrogenic extrapyramidal symptoms.

Typical neuroleptic therapy often results in extrapyramidal symptoms (EPS) and tardive dyskinesia (TD). Recent reports reveal neurotoxic activity in some neuroleptics. We hypothesized that neurotoxicity might be implicated in EPS. This study aims to evaluate the neurotoxic activity of typical and atypical neuroleptics and to determine the possible role of neurotoxicity in neuroleptic-induced EPS. Perphenazine, haloperidol, clozapine, sulpiride, and risperidone (10-100 microM) were administered, either alone or combined with dopamine, to primary mouse neuronal or intact brain culture and to a human neuroblastoma (NB) cell line (SK-N-SH). Cell viability (measured by neutral red and alamar blue), DNA fragmentation (flow cytometry-NB) were determined. Neuroblastoma: perphenazine, clozapine, and haloperidol (100 microM) decreased viability by 87, 43, and 34% respectively. Sulpiride and risperidone were not toxic. At 10 microM, toxicity decreased markedly. Dopamine (125 microM) potentiated the perphenazine-induced toxicity. Flow cytometry of NB cells treated with perphenazine (2.5-40 microM) showed an increase (perphenazine 20 microM, 40 microM, 48 h) in fragmented DNA (74.7% and 95.0% vs. 8.7% in controls). Lower concentrations increased the G1 phase and decreased S phase in the cell cycle. In primary neurons, perphenazine, haloperidol, and clozapine, but not risperidone and sulpiride, induced a significant neurotoxic effect, which, in intact brain culture, was absent (haloperidol and clozapine) or lowered (perphenazine). Dopamine (0.5 mM) did not modify the effect of the drugs in the primary cultures. Neuroleptics possess differential neurotoxic activity with higher sensitivity of neoplasm tissue (NB compared to primary cultures). The order of toxicity was perphenazine > haloperidol = clozapine:sulpiride and risperidone were not toxic. Neurotoxicity is independent of dopamine and is associated with cell cycle arrest and apoptosis. With the exception of clozapine, neurotoxicity seems relevant to neuroleptic-induced EPS and TD.

Animals↗
PubMed2001

Depressive symptoms and suicidality in physically abused children.

Depressive symptoms and suicidality were assessed in 114 children 6-12 years old, of whom 41 had been physically abused, 38 neglected, and 35 neither abused nor neglected. The physically abused children manifested significantly higher levels of depressive symptomatology and suicidality than did the other two groups. Implications for research and clinical practice are discussed.

Aggression↗
PubMed2001

Association of anorexia nervosa with the high activity allele of the COMT gene: a family-based study in Israeli patients.

Anorexia nervosa (AN) is a common, severe and disabling psychiatric disorder, characterized by profound weight loss and body image disturbance. Family and twin studies indicate a significant genetic contribution and pharmacological data suggest possible dysfunction of the serotonergic and dopaminergic pathways. Catechol-O-methyltransferase (COMT) is a candidate gene for mediating susceptibility to AN since it is involved in the dopamine catabolism and because its functional polymorphism (Val/Met 158) determines high (H) and low (L) enzymatic activity alleles. Fifty-one Israeli AN patients and their parents were genotyped with the COMT polymorphism. Using the haplotype relative risk (HRR) method it was found that the frequency of the H allele among alleles transmitted to AN patients from their parents was significantly higher than in those not transmitted (68% vs 51% chi(2) = 5.20, df = 1, P = 0.023, odds ratio: 2.01). Transmission disequilibrium test (TDT) revealed that out of 49 heterozygote parents the H allele was transmitted to AN patients 33 times while the L allele was transmitted only 16 (McNemar's chi(2) = 5.90, df = 1, P = 0.015). Our study suggests that the COMT gene is associated with genetic susceptibility to AN, and that individuals homozygous for the high activity allele (HH) have a two-fold increased risk for development of the disorder.

Adolescent↗
PubMed2001

Metabolic bioenergy homeostatic disruption: a cause of anorexia nervosa.

We believe anorexia nervosa is the result of a disruption in bioenergy homeostasis induced by lipid dysregulation. This disruption has two major determinants: (1) a biological predisposition to primary multihormonal disharmony linked to post-pubertal growth and development; and (2) an acquired abnormal lipid-induced loop operation precipitated by inappropriate diet. We present a step-by-step model describing the cascade of disorders that culminates in anorexia nervosa: defective digestion and absorption of essential fatty acids; diversion of lipids from adipose cells into bloodstream; defective carbohydrate and lipid metabolism which modifies the blood brain barrier; neuroendocrine membrane alteration causing severe endocrine impairment; changes in the negative feedback mechanism which escalate the body's use of bioenergy; derangement of the appetite center which causes a constant sensation of satiety; replacement of the correct body image with the premorbid one that encourages poor judgement concerning food intake and self-support. The loop-like nature of this mechanism perpetuates the disease.

Adipose Tissue↗
PubMed2001

Zuclopenthixol treatment of behavioral disturbances in mentally retarded children and adolescents: an open-label study.

The present open-label study assessed the efficacy of zuclopenthixol, an thioxanthene neuroleptic with combined dopamine receptors (D1/D2) antagonist activity, in the treatment of severe behavioral disturbances in mentally retarded children and adolescents. A sample of 15 (11 males, 4 females) mentally retarded children and adolescents, ages 5-18 years (12.2 +/- 2.3 [mean +/- SD] years), all exhibiting severe behavioral disturbances, was evaluated. The 12-week zuclopenthixol treatment (up to 26 mg/day) was initiated after a week's washout from previous antipsychotic agents. An assessment of the behavioral disturbances was performed using the 14-item Checklist for Behavior Problems Involving Limited or No Social Awareness (CBP-NSA). The Udvalg for kliniske undersøgelser (UKU) Side Effect Rating Scale was used to assess the pharmacologic side effects. Results show a significant reduction in total CBP-NSA scores and in individual items such as hyperactivity, aggressive behavior, and temper tantrums (p < 0.001 for each). It seems that zuclopenthixol monotherapy is effective and well tolerated in the treatment of severe behavioral disturbances in mentally retarded children and adolescents. Double-blind, placebo-controlled studies are needed before definitive conclusions can be drawn regarding the efficacy and safety of zuclopenthixol for this population.

Adolescent↗
PubMed2001

Cyproheptadine versus propranolol for the treatment of acute neuroleptic-induced akathisia: a comparative double-blind study.

The purpose of this study was to investigate the efficacy of cyproheptadine, an antiserotonergic agent, in the treatment of neuroleptic-induced akathisia (NIA), as compared with propranolol, the current gold standard. In a double-blind trial, 30 patients with schizophrenia and NIA received either cyproheptadine 16 mg/day (N = 18) or propranolol 80 mg/day (N = 12) for 4 days, followed by 3 days without any anti-NIA treatment. The Barnes Akahisia Scale, Simpson-Angus Extrapyramidal Effects Rating Scale, and Brief Psychiatric Rating Scale were used to assess the severity of NIA, parkinsonism, and psychosis, respectively. In both groups, the severity of NIA decreased significantly over time (cyproheptadine, -46%; propranolol, -42%), with no significant intergroup difference. The NIA symptoms worsened significantly when cyproheptadine and propranolol were discontinued. We conclude that cyproheptadine 16 mg/day is as effective as propranolol for the treatment of acute NIA. The antiakathisic effect of cyproheptadine may be mostly attributable to its serotonin antagonistic activity.

Adrenergic beta-Antagonists↗
PubMed2001

Changes in vesicular monoamine transporter (VMAT2) and synaptophysin in rat Substantia nigra and prefrontal cortex induced by psychotropic drugs.

We investigated the regulatory effect of the dopaminergic agent L-dopa, the mood stabilizer lithium and the nonselective monoamine oxidase inhibitor phenelzine on brain vesicular monoamine transporter (VMAT2) expression. Rats were treated chronically (21 days) with the three psychoactive drugs. VMAT2 gene expression at the protein level was assessed in the prefrontal cortex and striatum by autoradiography with high-affinity [(3)H]dihydrotetrabenazine ([(3)H]TBZOH) binding and at the mRNA level in the substantia nigra pars compacta by in situ hybridization. In addition, the effect of various treatments on the synaptophysin mRNA level was determined in the substantia nigra by in situ hybridization. Chronic administration of L-dopa resulted in a significant decrease (28%, p < 0.05) in the density of [(3)H]TBZOH binding in the prefrontal cortex but had no effect on VMAT2 and synaptophysin mRNA levels in the substantia nigra. Lithium treatment increased [(3)H]TBZOH-specific binding in the prefrontal cortex (23%, p < 0.05) but had no effect on VMAT2 and synaptophysin mRNA levels. Phenelzine did not modulate VMAT2 gene expression but reduced the synaptophysin mRNA level (19%, p < 0.05). The modulatory activities of these drugs, although relatively weak, may be relevant to the drug-induced synaptic and neuronal plasticity as well as to the molecular and cellular pathophysiology of monoamine-related neuropsychiatric disorders.

Animals↗
PubMed2001

Effectiveness of dynamic cognitive intervention in rehabilitation of clients with schizophrenia.

OBJECTIVE: To examine the efficacy of dynamic cognitive treatment in rehabilitation of schizophrenic clients. SUBJECTS: Fifty-eight schizophrenic clients that were matched equally into two groups: a study group (n = 29) (treated by Instrumental Enrichment) and a control group (treated with traditional occupational therapy methods). SETTING: The subjects were treated in a day rehabilitation centre in the community. STUDY DESIGN: The programme lasted one year, the same schedule was provided for both groups. Subjects were randomly assigned and assessed before and after intervention with the same battery and at a follow-up six months later, work and residence status were evaluated. MAIN OUTCOME MEASURES: Instruments included: (1) memory and thought processes, measured by a battery of structured tests from the Learning Potential Assessment Device (LPAD), Raven Progressive Matrices and General Aptitude Test Battery (GATB); (2) functional outcomes, instrumental activities of daily living (IADL), measured by a questionnaire; work and residence status; (3) self-concept measured with Fitts questionnaire. RESULTS: Results showed significant differences between the groups on almost all the cognitive tests (MANOVA revealed significant differences between the two groups for both memory and thought process (F(2.52) = 13.75, p < 0.001; and F(1.46) = 7.28, p < 0.001, respectively) as well as in work (chi2 = 14.30, p < 0.001), and residence (chi2 = 3.86, p < 0.05) status. There were no significant differences in IADL questionnaire or the self-concept scale. CONCLUSIONS: The successful outcome points to the importance of including long-term cognitive intervention in rehabilitation of schizophrenic clients. This work suggests that the classic view of schizophrenia as a progressive irreversible decline that cannot be altered may be wrong.

Activities of Daily Living↗
PubMed2001

Insulin, insulin-like growth factors-I and -II and insulin-like growth factor binding protein-3 in newborn serum: association with normal fetal head growth and head circumference.

The insulin-like growth factors (IGF) and their binding proteins (IGFBP) have been implicated in the regulation of fetal weight and length. The aim of our study was to determine the relationship between head circumference at birth and serum levels of IGF-I, IGF-II, IGFBP-3 and insulin in full-term appropriate-for-gestational age (AGA) infants. Serum samples were obtained from 77 singleton full-term neonates, 69 AGA and 8 small-for-gestational age (SGA). The AGA infants were divided into three groups by head circumference: Group 1: < or = 3rd percentile; Group 2: at 50th percentile; Group 3: > or = 97th percentile. Serum levels of IGF-I, IGF-II, IGFBP-3 and insulin were determined with commercial kits and immunometric methods. There were no statistically significant differences in mean serum levels of IGF-I, IGF-II and IGFBP-3 between the groups. A significantly higher mean serum insulin level was noted in the AGA infants with a head circumference > or = 97th percentile compared to those with a head circumference < or = 3rd percentile (4.6 +/- 0.3 vs 3.3 +/- 0.6 microU/ml; p = 0.04), and in AGA infants with a head circumference above the 50th percentile compared to those with a head circumference below the 50th percentile (4.4 +/- 0.4 vs 3.3 +/- 0.3 microU/ml; p = 0.01). AGA infants with a head circumference above or below the 50th percentile did not differ statistically in their mean IGF-II and IGFBP-3 serum level, while IGF-I differed statistically between the groups (18 +/- 2.7 vs 11.6 +/- 1.6 ng/ml, respectively; p = 0.045). Using univariate analysis, head circumference correlated positively with insulin (r = 0.29; p = 0.016) and with IGF-I (r = 0.26; p = 0.03). A stepwise multivariate linear regression analysis, however, did show statistically significant correlation of head circumference with birth weight (f = 36; p = 0.0001), and only marginally with birth length (f = 4.7; p = 0.06) and insulin (f = 3.4; p = 0.07). No correlations were found between head circumference and IGF-I, IGF-II or IGFBP-3. These data suggest that apart from genetic and nutritional factors, insulin may play a role in promoting intrauterine head growth, as reflected by head circumference at birth.

Cohort Studies↗
PubMed2001

Obsessive compulsive behaviour in autism--towards an autistic-obsessive compulsive syndrome?

A portion of autistic patients exhibit compulsive-like behaviours. In addition it has been suggested that serotonin plays a major role in both obsessive compulsive disorder (OCD) and autistic disorder. Other neurohumors such as endogenous opioids and oxytocin have also been implicated in the two disorders. There is also some pharmacological overlap between the two disorders, as well as some similar neuroimaging studies. These similarities and overlaps have led us to propose a putative OCD-autistic disorder, which should be studied in greater detail.

Autistic Disorder↗