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Biomedical subjects

A Doran

Publications and source records attributed to A Doran.

26 records · Page 2Linked to original sources
PubMed1986

Chronic corticosterone administration in rats: behavioral and biochemical evidence of increased central dopaminergic activity.

Chronic corticosteroid treatment in humans in frequently complicated by behavioral changes. The present study suggests that chronic steroid administration in rats has distinct neurochemical consequences which are behaviorally relevant. Ten male Sprague-Dawley rats received 7 daily injections of corticosterone, following which they exhibited increased caudate homovanillic acid as well as an attenuated decline in vertical and ambulatory movement (functional measures of dopamine activity) compared to placebo-treated rats. A subgroup of steroid-treated rats which was more behaviorally responsive to corticosterone also showed increased caudate 5-hydroxyindole acetic acid and decreased prefrontal cortex dopamine and serotonin. These results are discussed in relation to the known behavioral side effects of chronic corticosteroid administration in man and the psychiatric manifestations of naturally occurring states of hypercortisolemia.

Animals↗
PubMed1986

Suicide and aggression in schizophrenia. Neurobiologic correlates.

In this study of schizophrenic patients, we were unable to find an association between past history of suicide attempt and levels of CSF amine metabolites, response to DST, and ventricular size by CT scan, neurobiologic variables each of which have been reported to be associated with attempted suicide in some patient groups. Our data, however, demonstrate the marked responsiveness of measures of aggressive behavior to neuroleptic treatment, suggesting a dopaminergic involvement in these behaviors when observed in the presence of overt psychotic symptoms. Some support for an association between decreased CNS serotonin function and aggressive behavior was found in drug-free schizophrenics, although difficulty in separating illness from trait factors is an important confounding variable. The need for clinical interventions required to treat severely disturbed and aggressive behavior in the schizophrenic patients studied could not be predicted by any of the neurobiologic variables.

Aggression↗
PubMed1986

The corticotropin-releasing hormone stimulation test in chronic schizophrenia.

During a drug-free period a group of schizophrenic subjects (N = 9) showed normal mean basal plasma ACTH and cortisol levels in association with normal plasma ACTH and cortisol responses to an infusion of corticotropin-releasing hormone (CRH). Administration of fluphenazine had no effect on basal ACTH and cortisol levels or their responses to CRH (N = 8). These data differ from those previously reported in depressed patients, who showed elevated basal cortisol values in association with a blunted ACTH response to CRH, and add to a growing body of literature which suggests that hypothalamic-pituitary-adrenal regulation is less disturbed in schizophrenia than in depression.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Neoplastic transformation of cells by soluble but not particulate forms of metals used in orthopaedic implants.

Recent developments in cell culture techniques have made it possible to study the cellular mechanisms involved in carcinogenesis and to apply these methods as screening tools in vitro. This study investigated and compared the ability of the metals most commonly used in orthopedic implants to induce toxicity and neoplastic transformation in the C3H10T1/2 mouse fibroblast cell line. Eight metals (cobalt, chromium, nickel, iron, molybdenum, aluminium, vanadium and titanium) and their alloys (stainless steel, cobalt-chrome alloy and titanium alloy) were tested, both as soluble salts and as solid particles. There were marked differences between the various metals in terms of both toxicity and transforming ability. Significant increases in the incidence of cell transformation were seen with soluble forms of cobalt, chromium, nickel and molybdenum but not with iron, aluminium, vanadium or titanium. For most of the metals. transforming ability was directly related to toxicity, although this correlation did not hold for either molybdenum or vanadium. The physical form of the metal was critically important in determining its effects, and transformation occurred only with soluble metal salts.

Alloys↗