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Biomedical subjects

R G Heath

Publications and source records attributed to R G Heath.

At least 19 recordsLinked to original sources
PubMed1999

Antiretroviral antibodies: implications for schizophrenia, schizophrenia spectrum disorders, and bipolar disorder.

BACKGROUND: Some retroviral antigens share structural homology within a group of related retroviruses. It is possible that antibodies directed against one virus may cross-react with antigens from a different virus in the group. METHODS: Using this principle, the human immunodeficiency virus 1 (HIV-1) Western blot assay was used as an available source of human retroviral antigens to screen serum samples from an archived collection to ascertain whether there was an association between serum antiretroviral antibodies and mental illnesses. RESULTS: A statistically significant proportion (28/54, 52%) of patients suffering from psychiatric disorders had serum antibodies that recognized at least one antigen present on the blot, culminating in indeterminate HIV-1 tests. The majority of the reactive samples were directed against the HIV-1 group antigens p24 and p17. These findings contrast with those of nonpsychiatric patients, who had 4/16 (25%) indeterminate blots. CONCLUSIONS: The results suggest exposure to retroviral antigens related to those of HIV-1 in subpopulations of schizophrenic, schizophrenic spectrum disorder, and bipolar disorder patients.

Antibodies, Viral↗
PubMed1989

Antiseptal brain antibody in IgG of schizophrenic patients.

On the hypothesis that schizophrenia is an immunological disorder in which antibody is produced against a unique antigen sequestered principally or exclusively in the septal region of the brain, we used crossed-immunoelectrophoresis (CIE) to evaluate reactivity of a gamma G immunoglobulin (IgG) fraction from serum of schizophrenic patients and nonschizophrenic control subjects with homogenates of tissues of septal region, hippocampus, vermal cerebellum, frontal cortex, and liver of rhesus monkeys. When IgG fractions of unmedicated schizophrenic patients and schizophrenic patients who had received neuroleptic medication for less than 24 hr were tested against septal region homogenate, a precipitin arc was identified, indicating a positive result, with more than 95% of the fractions. In contrast, IgG fractions of schizophrenic patients who had received neuroleptic medication for more than 24 hr were rarely positive. When schizophrenic fractions that tested positive against septal region homogenate were tested against homogenates of the other tissues, they were negative. Fractions of all nonschizophrenic control subjects were negative against all homogenates.

Autoantibodies↗
PubMed1984

Kappa opiate receptor agonists: effects on behavior and on brain function and structure in rhesus monkeys.

In the present study several drugs that are predominantly agonists of kappa receptors were tested in rhesus monkeys prepared with deep and surface brain electrodes. The administration of two benzomorphan derivatives and of ethylketocyclazocine induced acute behavioral effects resembling catatonia concomitant with generalized spike and slow-wave electroencephalographic activity at widespread brain sites, that lasted for about 1 hr. After administration of one to three doses of these agonists (the benzomorphan derivatives to five monkeys and the ethylketocyclazocine to two monkeys), chronic recording changes developed, characterized by continuous high-amplitude spiking activity focal at the anterior septal region and periaqueductal gray of the mesencephalon. They increased in intensity with the passage of time, the monkeys having been followed as long as 5 months without further drug administration. Light microscopy and electron microscopy showed no structural abnormalities in the monkey brains at the sites of altered recordings, although occasional dendritic atrophy was noted at all cortical and subcortical brain sites examined. Chronic recording changes did not develop in a monkey that received U-50,488H on eight occasions. And none of the electrode-implanted monkeys that served as controls (having received no kappa agonists) developed recording changes. The sites affected by the active kappa agonists were those at which abnormal activity has been correlated with psychotic behavior. The ability of the kappa agonists to induce a lasting physiologic change without corresponding structural change at those focal sites implicated in schizophrenia may prove a useful probe in further investigations into the cause of schizophrenia and its ultimate treatment.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1983

Finite element analysis of current pathways with implanted electrodes.

A technique for numerical solution to complex electric field distribution problems has been devised. The specific application for which it was developed is the analysis of current density and isopotential line spacing from implanted neurostimulation electrodes. Three configurations of cerebellar stimulation electrodes in clinical use were studied for current spread to regions distant from the cerebellum using a planar model of the human head, neck, and upper torso in mid-saggital section. It was found that an array of cathodes on the superior cerebellar surface and an array of anodes on the inferior cerebellar surface causes significant current spread to the brainstem, a prediction confirmed by clinical observation in patients with previously implanted electrodes of this configuration. Results modelling other electrode configurations are also presented, along with a study of the effects of possible inaccuracies in available impedance data for neural tissue.

Brain Diseases↗
PubMed1982

Cerebellar vermal atrophy in psychiatric patients.

Our findings indicate that a notable number of patients who have functional psychosis (50%) or seizures (38%) show cerebellar vermal atrophy on visual inspection of CAT head scans, in contrast to 0.5% to 3.7% of patients with other disorders. In addition to the visual reading of 1700 scans in the present study, we used two methods to demonstrate cerebellar vermal atrophy objectively: (i) low-density measurements of the posterior fossa in relationship to total brain area, and (ii) sagittal reconstruction of the vermis. We postulate that cerebellar vermal atrophy reduces the cerebellum's inhibitory influences on activity of the rostral forebrain structures where unit overactivity has been correlated with emotional dyscontrol and clinical seizures. We further postulate that cerebellar vermal atrophy reduces facilitory activity of the brain's pleasure system (septal region).

Adult↗
PubMed1981

Cerebellar pacemaker patients: an update.

Of the initial group of 38 patients in whom we have used cerebellar stimulation for treatment of intractable behavioral pathology, 25 continue to have beneficial effects. However, there have been significant technical problems due to failure of the equipment. While impairing treatment, these complications have provided inadvertent controls. The procedure must still be considered developmental at this time, despite promising therapeutic efficacy.

Cerebellum↗