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Biomedical subjects

J G Csernansky

Publications and source records attributed to J G Csernansky.

At least 91 records · Page 5Linked to original sources

Growth hormone response to growth hormone releasing hormone in depression and schizophrenia.

Growth hormone releasing hormone, a 44-amino acid peptide (GHRH-44), was administered (1 micrograms/kg i.v.) to 6 normal controls, 10 schizophrenic subjects, and 7 depressed subjects. A significantly lower growth hormone (GH) response was found in the schizophrenic and depressed groups. Two molecular forms of GH, 22K GH and 20K GH, were also measured but did not further differentiate the three groups of subjects.

Adult↗

Correlates of rapid neuroleptic response in male patients with schizophrenia.

Correlates of neuroleptic response latency were assessed in 16 male schizophrenic inpatients during 4 weeks of fixed dose (20 mg/day) haloperidol treatment. Rapid responders showed a mean 40% reduction in Brief Psychiatric Rating Scale (BPRS) positive symptom scores by day 10 of treatment. Rapid responders had significantly lower plasma homovanillic acid (pHVA) concentrations compared to non-rapid responders during week 4 of haloperidol treatment. However, rapid versus non-rapid responders did not differ with respect to demographics, baseline positive or negative BPRS symptom scores, performance on tests of neuropsychological function, or mean plasma haloperidol concentrations.

Adult↗

Distinguishing depression and negative symptoms in unmedicated patients with schizophrenia.

Depression can occur in schizophrenia but can be difficult to distinguish from negative symptoms of the illness. To evaluate whether concurrent use of the Hamilton Rating Scale for Depression (HRSD) and the Brief Psychiatric Rating Scale (BPRS) could successfully separate depression and negative symptoms, we examined ratings on 69 unmedicated schizophrenic inpatients. A classical BPRS depression subscale score correlated highly (rho = 0.80) with the HRSD total score. The classical BPRS "negative symptom" subscale score was unrelated to both the BPRS and HRSD depression summary measures. Among individual HRSD items, negative symptoms correlated only with work/activities and retardation. The findings suggest that negative and depressive symptoms may be assessed independently.

Adult↗

A microassay for measuring synaptosomal 3H-dopamine and 3H-metabolite release.

A modified synaptosomal superfusion apparatus is described which uses less than 10 micrograms of tissue per replicate sample and facilitates the routine separation of 3H-DA, 3H-DOPAC, and 3H-HVA. A flow rate of 1.5 ml/min allows superfusion without the use of reuptake or monoamine oxidase inhibitors. Superfusate samples are collected directly onto alumina columns for the separation of 3H-DA and its acid metabolites. Total recovery of authentic 3H-DA applied via superfusion was 87.63(1.10) percent [Mean(SEM)]. Contamination of the acetic acid eluate fraction, containing 80.98(1.15)% of the total DA, by DOPAC and HVA was less than 0.1%. To illustrate the utility of this technique, the relative proportions of 3H-DA and 3H-metabolites released from synaptosomes by 6 mM potassium and 1 microM reserpine were compared.

3,4-Dihydroxyphenylacetic Acid↗

Limitations of the Mini-Mental State Examination in predicting neuropsychological functioning in a psychiatric sample.

The present study examined the ability of the Mini-Mental State Examination (MMSE), a cognitive screening test commonly employed in research and clinical applications, to predict level of performance on a comprehensive neuropsychological battery, the Luria-Nebraska Neuropsychological Battery (LNNB). The tests were administered to a diagnostically mixed sample of 90 psychiatric inpatients. Correlations between the tests were statistically significant but modest and the MMSE was not able to detect many patients who demonstrated significant deficits on the LNNB. Additional correlational analyses between the MMSE and the Wechsler Adult Intelligence Scale-Revised in a subset of patients (n = 72) also showed a modest relationship between these instruments. The results suggest that the MMSE may seriously underestimate cognitive impairment in samples exclusively composed of psychiatric patients, making it inappropriate to rely solely on this instrument to distinguish psychiatric patients with and without cognitive deficit.

Adult↗

5-HIAA in cerebrospinal fluid and deficit schizophrenic characteristics.

Higher CSF 5-HIAA concentrations and lower CSF HVA concentrations have been associated with various measures of slowed motor behaviour and communication in schizophrenic patients. To derive a single, reliable measure of deficit characteristics in schizophrenic patients, we entered four items of the BPRS reflecting negative symptoms, a work history measure derived from the Strauss-Carpenter scale, and three subscale scores of the WAIS-R into a principal-components analysis to derive a single factor score. The CSF 5-HIAA concentrations were within the normal range of values, and correlated directly with this factor score, but CSF HVA concentrations were not associated with the deficit factor score. These findings add support to the hypothesis that brain serotonin function is associated with deficit schizophrenic characteristics.

Adult↗

Postpartum psychosis with abnormal movements: dopamine supersensitivity unmasked by withdrawal of endogenous estrogens?

The authors describe two cases of postpartum psychosis accompanied by abnormal extrapyramidal movements. The presentation of these cases, as well as research evidence indicating that estrogens influence dopamine receptor function, leads the authors to hypothesize that dopamine receptor supersensitivity may have been induced by prepartum increases in endogenous estrogens and unmasked by postpartum estrogen withdrawal.

Adult↗

Differences in the time course of dopaminergic supersensitivity following chronic administration of haloperidol, molindone, or sulpiride.

The onset and persistence of changes in 3H-spiroperidol binding to dopamine (DA) D2 receptors were examined in rat mesolimbic and striatal brain regions following daily administration of haloperidol, molindone, or sulpiride for 3, 7, 14, or 28 days. Neuroleptic dose equivalencies were determined by inhibition of 3H-spiroperidol in vivo binding in several rat brain regions. Changes in locomotor and stereotyped responses to the specific DA D2 agonist quinpirole were examined 3 days after the last treatment dose. Haloperidol or molindone administration increased mean stereotypy scores and striatal DA D2 receptor densities throughout the 28-day treatment period. In contrast, mesolimbic DA D2 receptor densities were transiently increased and returned to control values, after 28 days of haloperidol or molindone treatment. Sulpiride treatment increased mean stereotypy scores and striatal Bmax values, but had no effect on locomotion or mesolimbic dopamine receptor density. Additionally, the magnitude of change in the various measures of brain DA function varied among the three neuroleptic treatment groups. Results from this study suggest that mesolimbic and striatal brain regions differ in their response to long-term neuroleptic administration and that drug choice may influence the magnitude of neuroleptic-induced dopaminergic supersensitivity.

Animals↗

Correlations between the MMPI and the Brief Psychiatric Rating Scale in schizophrenic and schizoaffective patients.

Though self-report measures and clinician-based ratings are extensively used to document psychopathology, there has been little work examining the relationship between these different types of measurement techniques. The current work examined the relationship between the Minnesota Multiphasic Personality Inventory (MMPI) and the Brief Psychiatric Rating Scale (BPRS) in patients with schizophrenia and schizoaffective disorder. Correlations were calculated in an initial exploratory sample, and a set of relationships was selected for confirmation in a second sample. The BPRS items of hallucinatory behavior and tension significantly correlated with MMPI measures of psychoticism. BPRS measures of hostility correlated with scale 4 (Psychopathic Deviate) of the MMPI. BPRS and MMPI measures of depression also were related. In contrast, BPRS and MMPI measures thought to reflect negative symptoms were uncorrelated. These results offer behavioral validity for the use of the MMPI in schizophrenic samples and suggest that the two measures tap similar as well as separable symptom constructs thought to be common in schizophrenia.

Adult↗

CSF phenylacetic acid and hostility in paranoid schizophrenia.

Lumbar cerebrospinal fluid concentrations of phenylacetic acid were significantly elevated in paranoid vs. nonparanoid schizophrenics. Further, phenylacetic acid concentrations were correlated with hostility. These results are consistent with the hypothesis that phenylethylamine, the proposed precursor of phenylacetic acid, plays a role in schizophrenia.

Adult↗

Independence of positive and negative symptoms in a population of schizophrenic patients.

Numerous recent studies have divided schizophrenic patients into subgroups based on a predominance of positive or negative symptoms. These works often assume that these symptoms are distributed discontinuously or inversely. In the present work, we sought relationships between positive and negative schizophrenic symptoms in a medication-free inpatient population of schizophrenic patients (N = 61). Measures of positive and negative symptoms were derived from clinical ratings using the Brief Psychiatric Rating Scale. No correlations were found between positive and negative symptoms in the entire group, or in subgroups defined by duration of illness or diagnostic subtype. Furthermore, no correlations were found between positive or negative symptoms and age, age at onset of illness, or duration of illness. These data suggest that positive and negative symptoms vary independently among patients; knowledge about the level of positive symptoms provides no predictive information about negative symptoms. In addition, the distribution of patients showed that a large percentage have a mixture of positive and negative symptoms. Accordingly, methodologies that form restrictive subgroups of patients with exclusively positive or negative symptoms may have little generalizability to schizophrenic populations. The results suggest that schizophrenic patients should not be routinely subtyped as predominantly positive or negative.

Adult↗

A preliminary dose-ranging trial of proglumide for the treatment of refractory schizophrenics.

A dose-finding study of proglumide added to neuroleptics for the treatment of schizophrenic patients who were relatively refractory to their ongoing neuroleptic regimen was performed. Initially, four patients were open-label treated using a regimen of progressively increasing doses (proglumide 0.5-1024 mg/day) for 4 weeks. Afterwards, seven patients were given low doses (0.5 mg/day) followed by higher doses (500 mg/day) for a total period of 8 weeks. Overall, no improvement was seen in these refractory patients as a group at any dose. In individual patients, modest improvement or worsening of psychotic symptoms was observed. The results suggest that more potent cholecystokinin (CCK) antagonists and a greater knowledge of CCK pharmacology are needed before novel treatments exploiting the interaction of CCK and dopamine in the brain can be developed.

Antipsychotic Agents↗

Mesolimbic dopamine receptor increases two weeks following hippocampal kindling.

Kindled seizures developed in rats following repeated electrical stimulation of the left CA1 region of the hippocampus. Two weeks after the final kindled seizure, the densities of dopamine (DA) D2 receptors were assayed in the left and right amygdaloid area, nucleus accumbens, and nucleus caudatus. A significant increase (107%) in the density of DA D2-receptors in the ipsilateral nucleus accumbens occurred. This finding may help to define the long-term neurochemical consequences of kindling.

Animals↗

Mesolimbic dopaminergic supersensitivity following electrical kindling of the amygdala.

Limbic seizures developed in rats following daily electrical stimulation of the basolateral nucleus of the amygdala. Animals were designated as "kindled" after five complete (stage 5) behavioral seizures were observed. A subgroup, designated as "superkindled," received three additional weeks of electrical stimulations. Kindled rats were significantly subsensitive to the stereotypy-inducing effects of apomorphine, a direct dopamine agonist, compared to controls. Superkindled rats were supersensitive to the effects of apomorphine. However, both kindled and superkindled rats demonstrated an increase in 3H-spiperone Bmax values, reflecting dopamine D2-receptor densities, in the nucleus accumbens ipsilateral to the stimulating electrode. The number of interictal spikes recorded from the stimulating amygdaloid electrode during the last week of kindling was correlated with changes in apomorphine sensitivity in individual animals.

Amygdala↗

Double-blind comparison of alprazolam, diazepam, and placebo for the treatment of negative schizophrenic symptoms.

Fifty-five schizophrenic outpatients with negative symptoms were treated for up to six weeks by the addition of alprazolam (mean dose, 4.2 mg/d), diazepam (mean dose, 40.4 mg/d), or placebo to their ongoing neuroleptic treatment. A repeated-measures analysis of variance with baseline measurements entered as covariates indicated the presence of a significant time X drug interaction effect for the weekly Brief Psychiatric Rating Scale (BPRS) withdrawal/retardation subfactor scores. During the initial weeks of the study, the alprazolam-treated group had lower scores, while the diazepam-treated group had higher scores than the placebo-treated group. However, an end point analysis performed on the final BPRS withdrawal/retardation subfactor scores showed no significant differences among the three groups, nor were beneficial effects observed on any of the BPRS subfactor scores that assess positive symptoms. Plasma alprazolam levels were maintained throughout the study and ranged from 20 to 100 ng/mL. These results suggest that alprazolam had no sustained significant effect on negative schizophrenic symptoms.

Adult↗

Differences in the time course of haloperidol-induced up-regulation of rat striatal and mesolimbic dopamine receptors.

Regional differences in the onset and persistence of increased dopamine D2 receptor density in rat brain were studied following daily injections of haloperidol for 3, 7, 14, or 28 days. Striatal [3H]-spiroperidol Bmax values were significantly increased following 3-28 days of haloperidol treatment, as compared to saline controls. Olfactory tubercle Bmax values were significantly increased only after 14 or 28 days of haloperidol treatment. Nucleus accumbens Bmax values were significantly increased only in the 14-day drug treatment group, suggesting that dopamine D2 receptor up-regulation in nucleus accumbens may reverse during ongoing neuroleptic treatment. These findings suggest that important differences in adaptive responses to chronic dopamine blockade may exist between dopaminergic synapses located in various rat brain regions.

Animals↗