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Biomedical subjects

G M MacQueen

Publications and source records attributed to G M MacQueen.

28 records · Page 2Linked to original sources
PubMed1999

A two-illness model of bipolar disorder.

The current approach to mood disorders is that bipolar disorder, comprising both mania and depression, is a discreet illness distinct from unipolar depression. This formulation has profoundly influenced the approach to understanding the biology and etiology of these disorders, as well as the manner in which the various phases of bipolar disorder are treated. Our new model suggests that bipolar disorder comprises two distinct illnesses, mania and depression, and that bipolar depression is no different from unipolar depression. Studies of clinical syndromes, course of illness, family history and genetics, biological factors, and treatment response data directly or indirectly support this new model.

Antidepressive Agents↗
PubMed1999

G Protein-coupled cyclic AMP signaling in postmortem brain of subjects with mood disorders: effects of diagnosis, suicide, and treatment at the time of death.

Components of cyclic AMP (cAMP) signaling were examined in postmortem cerebral cortex of a well characterized group of patients with mood disorders and nonpsychiatric control subjects. We measured G protein levels, adenylyl cyclase (AC) activity, and CREB levels in cerebral cortex of the subjects with respect to diagnosis, treatment, and suicide. There was no effect of diagnosis on any measure, except for a trend toward decreased stimulated AC activity in subjects with mood disorders relative to control subjects. We also detected a significant effect of suicide on temporal cortex CREB levels in subjects that died as a result of suicide relative to those that did not, which was more evident in patients with major depressive disorder. Bipolar disorder (BD) subjects treated with anticonvulsants at the time of death had decreased temporal cortex CREB levels relative to those not receiving anticonvulsants. Furthermore, we found a trend toward decreased occipital cortex G alpha(s) (short) levels in BD subjects treated with lithium. These results support the hypothesis of altered cAMP signaling in mood disorders and raise the possibility that factors other than diagnosis, such as treatment and suicide, may be relevant to cell-signaling abnormalities reported in the literature.

Adenylyl Cyclases↗
PubMed1998

Neuropsychiatric aspects of the adult variant of Tay-Sachs disease.

Tay-Sachs disease (a GM2 gangliosidosis) is an inherited neuronal storage disease that can affect individuals across the age spectrum. Psychosis is reported in 30% to 50% of adult-onset patients, and many are misdiagnosed with schizophrenia. Mood disorders are present in more than 25% and cognitive impairment in more than 20%. Treatment of psychosis with neuroleptics may not have a favorable risk/benefit ratio, but treatment with benzodiazepines or electroconvulsive therapy may be efficacious. Metabolic diseases such as gangliosidosis are probably under-recognized as causes of neuropsychiatric illness. Increased awareness of these disorders will lead to accurate diagnosis, appropriate treatment selection, and genetic counseling.

Adult↗
PubMed1997

Levels of functioning and well-being in recovered psychotic versus nonpsychotic mania.

The aim of the study was to compare psychotic and nonpsychotic bipolar patients on demographic and outcome measures. Sixty two patients with bipolar disorder were divided into groups on the basis of psychosis during an index episode of mania. Groups were compared on demographic, clinical and outcome measures. Psychotic patients were more symptomatic during the index episode, but they did not differ from nonpsychotic patients on ratings of function and well being when euthymic. Psychosis occurring within the context of an exacerbation of mania does not seem to predict a poorer outcome when patients return to the euthymic state. A limitation of the present study is that it involves short-term outcome, but the data can be used to inform patients and family about the possibility of full recovery even in the psychotic form of mania.

Adult↗
PubMed1995

Late-onset Tay-Sachs disease presenting as catatonic schizophrenia: diagnostic and treatment issues.

BACKGROUND: It is not commonly appreciated that patients with hexosaminidase A deficiency (Tay-Sachs disease) can first present in adulthood with psychiatric illness. METHOD: A 17-year-old non-Jewish male patient was referred with a history of treatment-resistant catatonic schizophrenia. We uncovered coexistent neurologic abnormalities and evidence of cognitive decline. Metabolic screening revealed a severe deficiency of beta-hexosaminidase A. We reviewed the literature on late-onset gangliosidosis with attention to (1) the nature of the associated psychiatric and neurologic abnormalities and (2) the treatment of psychosis in these patients. RESULTS: The patient's catatonia responded promptly to benzodiazepine therapy. Treatment with neuroleptic medication resulted in the rapid development of neuroleptic malignant syndrome. The patient was thereafter maintained on lorazepam with resolution of his acute psychiatric disturbances and unexpected improvement in his neurologic status. CONCLUSION: Patients with hexosaminidase deficiency may first present in adolescence or adulthood with psychiatric illness, particularly schizophrenic-like psychosis. The presence of speech disturbance, gait abnormalities, movement disorders, and cognitive decline may indicate an underlying metabolic disorder. The use of traditional neuroleptics to treat the psychosis in such individuals may produce an unacceptably high risk/benefit ratio. Benzodiazepines may ameliorate the psychiatric and neurologic abnormalities in these patients.

Adolescent↗
PubMed1989

Conditional immunomodulation following training with cyclophosphamide.

In 5 experiments, paired-group rats received a conditional stimulus (CS) paired with the immunosuppressive drug cyclophosphamide (CY). In Experiments 1-3, the CS was saccharin (SAC). Consistent with previous reports, these rats acquired a SAC aversion. However, there was no evidence of conditional immunosuppression. Rather, when reexposed to SAC in conjunction with an antigenic challenge, paired-group rats evidenced hemagglutination antibody titers similar to those seen in rats that never received the immunosuppressant. That is, the usual effect of CY in compromising immunological functioning was attenuated or eliminated by the CY-paired flavor. The findings of Experiments 1-3 were confirmed in Experiments 4-5, which used nongustatory CSs. Both audiovisual (noise and flashing-light) and pharmacological (pentobarbital) cues were also effective signals for CY injection. Following pairing with CY, these cues protected animals from the immunosuppressive effects of the drug.

Animals↗
PubMed1989

Color aftereffect contingent on text.

During adaptation, two different letter strings (each five or six letters) were presented to subjects alternately, one in green and the other in magenta. The extent to which these letter strings subsequently elicited a color aftereffect was assessed. In different experiments, the chromatic letter strings consisted of words and nonwords. The results indicated that letter strings that form English words can contingently elicit a color aftereffect. This was the case even when the words were anagrams. There was no evidence that nonword letter strings could contingently elicit such an aftereffect, even when the nonwords conformed to English orthography. The results are relevant to understanding other contingent color aftereffects (McCollough effects), illusory color noted by computer operators who work at monochrome (green or amber) displays, and the processing of text.

Adult↗