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Biomedical subjects

J E Kleinman

Publications and source records attributed to J E Kleinman.

At least 19 recordsLinked to original sources
PubMed1992

Laterality of appendicular tardive dyskinesia in chronic schizophrenia.

The notion that the neuropathology of schizophrenia is lateralized is supported, in part, by findings of asymmetries in tardive dyskinesia (TD). To verify the existence of asymmetric TD, this study used the AIMS examination to look for lateralization of limb movements in a sample of 58 patients with TD. Patients with schizophrenia were compared with patients with affective and schizoaffective disorders. Asymmetry was seen in the majority of patients, regardless of psychiatric diagnosis. There was no preference for one side over the other. In a subgroup of 16 patients rates repeatedly over 13 weeks, the presence and sidedness of asymmetry fluctuated. At least four ratings were needed to accurately predict the presence and sidedness of "persistent" asymmetry. This study does not support the notion that there is a consistent, lateralized asymmetry of TD in patients with schizophrenia. Moreover, it raises questions about the reliability of assessment of persistent laterality in TD using a single exam.

Adult↗
PubMed1992

Cerebellar and frontal cortical benzodiazepine receptors in human alcoholics and chronically alcohol-drinking rats.

Postmortem cerebellar and frontal cortical membrane homogenates from human alcoholics, control subjects without neurological or psychiatric illnesses, and rats that chronically drank alcohol were studied to determine the binding characteristics of an imidazobenzodiazepine, [3H]Ro 15-4513. This ligand binds to classical gamma-aminobutyric acidA (GABAA)/benzodiazepine receptors, as well as to a "diazepam-insensitive" site associated with the GABAA receptor complex in the cerebellar granule cell layer. There were no differences in the density of the binding sites between alcoholics and their controls, between alcohol-drinking AA rats that had a choice between 10% alcohol or water for about 10 weeks and their controls, or between Wistar rats that had been given 20% alcohol as their only fluid for 4 months and their controls, which were pair-fed isocalorically with sucrose. The affinity for the cerebellar binding of [3H]Ro 15-4513 was higher in the alcoholics than the controls. No differences were observed in the frontocortical binding. No affinity differences were observed in the rat models. There were no differences between the groups in the characteristics of [3H]Ro 15-4513 binding to human cerebellum in the presence of micromolar diazepam, thus revealing the diazepam-insensitive binding. When this component was subtracted from the total cerebellar binding, to reveal the diazepam sensitive binding, both the KD and Bmax were lower in the alcoholic than the control group. The binding of [3H]muscimol, a GABAA agonist, tended to be higher in the frontal cortices of alcoholics; a similar trend for greater effects was observed in the alcoholics for the GABA inhibition of [3H]Ro 15-4513 binding. These results suggest that no drastic changes occur through chronic alcohol abuse in the numbers of cerebellar and frontocortical benzodiazepine receptors in humans and rodent models; however, the data indicate that the alcoholics have either acquired or innate differences in classical benzodiazepine recognition sites of the cerebellum and in the coupling of these sites to GABAA sites in the frontal cortex, without any differences in cerebellar granule cell-specific diazepam-insensitive [3H]Ro 15-4513 binding sites.

Adult↗
PubMed1992

D1 and D2 receptor modulation in rat striatum and nucleus accumbens after subchronic and chronic haloperidol treatment.

The antipsychotic effects of neuroleptic drugs are believed to be achieved by chronic blockade of dopaminergic transmission in the limbic system. Nevertheless, the effects of chronic (3-12 months) haloperidol administration on the dopaminergic transmission in the nucleus accumbens of rodents remains poorly understood. Studies of spontaneous locomotor activity (SLA), a behavioral measure related to limbic dopamine transmission, and of dopamine D2 receptor density in the nucleus accumbens after chronic oral haloperidol treatment have yielded conflicting results. We evaluated these indices after 8 months of parenteral administration of haloperidol decanoate. We report here that, after 8 months of parenteral treatment, SLA stays significantly decreased and D2 receptors in the nucleus accumbens exhibit the same up-regulation as in the striatum (about 50%). These results fail to support the notion of a different pattern of D2 receptor adaptation to neuroleptic treatment between the nucleus accumbens and the striatum. In contrast, dopamine D1 receptors were found to be unaffected in the nucleus accumbens but decreased in the striatum by 22% after 8 months of treatment. This observation could be relevant to the pathogenesis of tardive dyskinesia.

Animals↗
PubMed1992

Distribution of beta-adrenergic receptor subtypes in human post-mortem brain: alterations in limbic regions of schizophrenics.

The distribution of the beta 1 (beta 1) and beta 2 (beta 2) subtypes of the beta-adrenergic receptor was examined in rat and nondiseased control human tissue. The distribution of the beta 1 and beta 2 receptors was also examined in schizophrenic cases, with additional studies in schizophrenic suicide and nonschizophrenic suicide cases. Scatchard analysis of the binding of [125I]iodopindolol (IPIN) to cortical membranes showed a similar Kd in human (177 pM) and rat (161 pM), but a lower maximum binding site (Bmax) in the human tissue (18.7 fmol/mg protein and 55.6 fmol/mg protein). For the autoradiographic studies [125I]IPIN was used to visualize both subtypes (total) or was displaced with the selective beta 1-receptor antagonist ICI-89,406 to visualize beta 2 sites, or with the selective beta 2-receptor antagonist ICI-118,551 to visualize beta 1 sites. Important differences in the regional distribution of the two subtypes of the beta-adrenergic receptors were noted between rat and human. In the nucleus accumbens and ventral putamen (ventral striatum), a patchy distribution of beta 1 receptors was observed that was not evident in the rat. These patches were aligned with markers of the matrix compartment of the striatum. The schizophrenic cases showed significant increases in the labeling of the beta 1-receptor patches with [125I]IPIN. In contrast to the frontal cortex of the nondisease controls, the parietal and temporal cortex showed a high ratio of beta 1 to beta 2 receptors and a highly laminar organization of the subtypes. [125I]IPIN binding to beta 1 receptors was highest in the external laminae with the reverse gradient for the beta 2 subtype. The medial temporal cortex displayed an alteration in the ratio of the 2 subtypes of the beta-adrenergic receptor, with the parahippocampus and hippocampus of the human, in contrast to the rat brain, predominantly expressing the beta 2 receptor. Moreover, there were consistently higher densities of beta 2 receptors in the hippocampus of the right hemisphere than the left hemisphere of the nondisease controls. There was not a left and right hemispheric asymmetry of beta 2 receptors in the hippocampus of elderly schizophrenics or in young schizophrenics who committed suicide. The asymmetry was evident in nonschizophrenic suicides, suggesting that the lack of asymmetry in the hippocampus of schizophrenics is evident early in the disease process. Thus limbic structures show alterations in the patterning of beta 1 and beta 2 receptors in the schizophrenic cases.

Adult↗
PubMed1992

Staining intensity of brain iron in patients with schizophrenia: a postmortem study.

Evidence derived from both pharmacological and postmortem studies suggests that a disturbance of brain iron metabolism is involved in the pathophysiology of schizophrenia; i.e., the distribution of iron parallels that of dopamine, and variations in its brain concentration selectively modulate the binding affinity of the dopaminergic (D2) receptor. In the present study the authors examined the staining intensity of brain iron in postmortem specimens of 9 schizophrenic (SC) patients and 17 age-matched controls. Coronal sections were stained with the Perls's technique, photographed, and then studied using a computerized image analysis system. Optical density measurements were taken from the caudate nucleus, putamen, globus pallidus, and substantia nigra. This study revealed significant differences between groups only for the staining intensity of iron in the caudate nucleus (P less than 0.005). A review of the literature suggests that this finding may be the result of neuroleptic therapy and not a primary pathological feature of schizophrenia.

Adult↗
PubMed1991

Characterization of [125I]SCH 23982 binding in human brain: comparison with [3H]SCH 23390.

We studied binding of [125I]SCH 23982 in two regions of human brain, the caudate and the dorsolateral prefrontal cortex. Binding characteristics of [125I]SCH 23982 and of the non-iodinated tritiated analogue, [3H]SCH 23390, were compared. In caudate, binding of [125I]SCH 23982 was consistent with binding to D1 dopamine receptors while in frontal cortex, [125I]SCH 23982 bound mostly to serotonergic 5HT2 receptors. In contrast to [3H]SCH 23390, no evidence of binding of [125I]SCH 23982 to D1 receptors could be found in human frontal cortex. This indicates that iodination of SCH 23390 induces a decrease in its relative D1 versus 5HT2 selectivity that prohibits the use of [125I]SCH 23982 to label D1 receptors in human cortex.

Adult↗
PubMed1991

Computed tomography measurements of brain density in Schizophrenia.

Although previous studies have reported differences in computed tomography (CT) scan attenuation values between patients with schizophrenia and controls, interpretation of these findings has been hindered by methodological shortcomings such as the failure to control for head size, scanner calibration differences, and other confounding variables. In the present study of CT attenuation values in multiple brain regions in 20 patients with chronic schizophrenia and an equal number of age- and sex-matched normal subjects we controlled for head size and normalized the attenuation values for each scan to an internal standard. No significant differences emerged between the patients with schizophrenia and the controls. However, in the controls only, the mean density of white matter in the left frontal area was significantly higher (t = -2.83, p = 0.01) than that in the right. The results, although possibly suggestive of deviant lateralization in schizophrenia, raise questions about the sensitivity and validity of regional CT attenuation values in detecting subtle anatomic abnormalities in patients with this illness.

Adult↗
PubMed1991

Selective loss of cerebral cortical sigma, but not PCP binding sites in schizophrenia.

Drugs such as phencyclidine (PCP) that interact with PCP and sigma binding sites can produce psychotomimetic effects that resemble some symptoms of schizophrenia. Therefore, it has been suggested that PCP and sigma receptors may be important in the clinical manifestations of schizophrenia. Assays of these two binding sites in human postmortem brains showed consistent significant reductions in the density of sigma, but not PCP sites, in schizophrenics as compared with age-matched and postmortem interval-matched normal and suicide controls. Reductions in the density of sigma binding sites in schizophrenia were most prominent in temporal cerebral cortex, and were accompanied by a small increase in affinity for the ligand [3H]haloperidol. These data provide the first evidence for alterations in sigma binding sites in schizophrenia, and suggest that selective sigma ligands may be useful in the treatment of the disorder.

Brain↗
PubMed1991

Enkephalin, dynorphin and substance P in postmortem substantia nigra from normals and schizophrenic patients.

Three peptide neuromodulators that are found in high concentration in the substantia nigra: dynorphin A 1-8, met5-enkephalin-arg6-gly7-leu8 and substance P, were measured by specific radioimmunoassays in nigral tissue from normals and schizophrenics postmortem. Substance P and dynorphin were unchanged between the two groups. However, the proenkephalin-derived peptide was significantly elevated in the schizophrenic group. The immunoreactivity was identified as authentic met5-enkephalin-arg6-gly7-leu8 by high pressure liquid chromatography. The data suggest that a different set of regulatory controls exists for nigral enkephalin peptides as compared to dynorphin and substance P, and that the former system may be disordered in schizophrenia.

Adult↗
PubMed1991

Dorsal hippocampal lesion does not affect dopaminergic indices in the basal ganglia.

To determine the influence of intrinsic neurons of the dorsal hippocampus on dopamine (DA) turnover in other limbic areas, DA and its metabolites were assayed in several brain areas 14 and 28 days after bilateral ibotenic acid (IA) lesions of the dorsal hippocampus in the rat. The locomotor response to d-amphetamine was also assessed. Spontaneous locomotion was increased 14 but not 28 days postoperatively. There was no change in d-amphetamine-induced locomotion at any time. Presynaptic indices of DA turnover in the medial prefrontal cortex, anteromedial striatum and nucleus accumbens were not affected by the lesion. Unlike lesions of the medial prefrontal cortex, deefferentation of the dorsal hippocampus does not increase DA turnover in the basal ganglia.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1991

3H-paroxetine binding in brains of alcoholics.

High affinity 3H-paroxetine binding was studied in human frontal cortex and hippocampus obtained from normal controls and alcoholics. On the basis of Scatchard analyses, a significant decrease in the maximal number of binding sites (Bmax) was found in the hippocampus of alcoholics (n = 8) as compared with that of controls (n = 10) (mean +/- SD = 63 +/- 35 vs. 114 +/- 70 fmoles/mg protein). There was no significant difference in the dissociation constants (Kd) between the two groups. The presumed effect of chronic alcohol abuse on 3H-paroxetine binding may be region-specific since no significant difference in either Bmax or Kd for 3H-paroxetine binding was found in the frontal cortex between normal controls and alcoholics. No significant correlation of 3H-paroxetine binding with age or postmortem interval was observed. The decrease in 3H-paroxetine binding in the hippocampus of alcoholics is probably indicative of reduced density of serotonergic nerve terminals either as a preexisting condition or as a result of neuronal damage caused by ethanol or the sequelae of alcoholism, such as nutritional deficiencies.

Adult↗
PubMed1991

Characteristics of [3H]GBR 12935 binding in the human and rat frontal cortex.

Binding characteristics of the selective dopamine uptake inhibitor [3H]GBR 12935 have been described for the striatum but not for the frontal cortex. We have developed assay conditions for quantifying [3H]GBR 12935 binding in the frontal cortex. In both the rat and human frontal cortex, the assay required four times more tissue (8 mg/ml) than in the striatum (2 mg/ml). [3H]GBR 12935 binding in the frontal is complex, as it involves multiple binding sites. The high-affinity binding site is sodium dependent and is inhibited by sodium. In human but not in rat frontal cortex, addition of K+ reversed the sodium inhibition. The pharmacological profile of the high-affinity [3H]GBR 12935 binding site is consistent with that of the dopamine transporter, because drugs with the most selective dopamine reuptake blocking activities are the most potent displacers of [3H]GBR 12935 binding. There is a positive correlation between the rat and human inhibitory constants, a finding indicating that there are similar pharmacological profiles across at least these two species. Rats with a 6-hydroxydopamine lesion had a 47% decrease in number of [3H]GBR 12935 binding sites, a result indicating that at least a portion of these sites had been on presynaptic dopamine terminals.

Animals↗
PubMed1991

Cognitive and behavioral effects of the coadministration of dextroamphetamine and haloperidol in schizophrenia.

OBJECTIVE: The authors sought to determine if an acute dose of dextroamphetamine might have positive effects on affect and cognition in schizophrenic patients maintained on a regimen of haloperidol and, if so, what variables might predict such improvements. METHOD: Twenty-one patients with chronic schizophrenia who were hospitalized on a research ward received a single oral dose of dextroamphetamine (0.25 mg/kg) in a double-blind, placebo-controlled, crossover study. All patients were receiving 0.4 mg/kg per day of haloperidol. Cognitive tests, motor tests, global ratings, mood ratings, and videotape ratings were used to determine the effect of the coadministration of these drugs. Ventricle-brain ratios derived from CT scans were used to predict response to the coadministration of these drugs. RESULTS: Amphetamine improved performance on a measure of concept formation on the Wisconsin Card Sorting Test but did not result in changes in performance on tests of memory or attention. As a group, the patients were more active and performed psychomotor tests more quickly while receiving amphetamine. Six patients were judged by clinical raters to have improved in terms of affect, cooperation, and engagement with the environment. Improvement was associated with enlarged cerebral ventricles and increases in blink rate from the placebo to the active drug condition. No patient unequivocally worsened. CONCLUSIONS: These results may be consistent with the theory that coadministration of amphetamine and haloperidol produces relatively selective enhancement of cortical dopaminergic activity. However, because of the acute nature of the trial and the specialized research environment in which it was conducted, the authors do not advocate amphetamine as a routine clinical treatment of schizophrenia.

Adult↗
PubMed1991

Differential diagnosis of choreiform tardive dyskinesia.

Orofacial dyskinesias and choreiform movements of limbs occur with moderate frequency among psychiatric patients. Abnormal involuntary movements are symptoms of a wide variety of neurological and medical disorders. For both therapeutic and medicolegal reasons, psychiatric patients should be thoroughly evaluated before being given the diagnosis of tardive dyskinesia. This review presents the differential diagnosis of disorders associated with orofacial and appendicular choreiform involuntary movements. In addition, this paper provides a guide to the clinical and laboratory evaluation of patients with these symptoms.

Athetosis↗