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Biomedical subjects

H A Nasrallah

Publications and source records attributed to H A Nasrallah.

16 recordsLinked to original sources
PubMed1992

Neuropsychological performance in asymptomatic HIV infection.

This study compared 74 human immunodeficiency virus (HIV)-negative and 131 HIV-positive asymptomatic homosexual or bisexual men on an extensive neuropsychological test battery. HIV-positive subjects' performance was significantly worse on verbal memory and psychomotor skills. The prevalence of mild but persistent neurobehavioral impairment in the HIV-positive group was approximately twice that in HIV-negative patients, consistently across several criteria for impairment. There was evidence that degree of neuropsychological impairment was related to patients' perceptions of dysfunction in daily life. Findings were not related to degree of depression or to medication effects. These data suggest that approximately 10% to 20% of HIV-positive asymptomatic men suffer mild neuropsychological impairment that influences their daily lives.

AIDS Dementia Complex↗
PubMed1979

A correlation between platelet monoamine oxidase activity and plasma prolactin concentrations in man.

Increases in plasma prolactin concentrations produced by alpha-methyl-p-tyrosine, a catecholamine synthesis inhibitor, varied inversely with baseline platelet monoamine oxidase activity in 12 patients with chronic schizophrenia. In normal volunteers with low monoamine oxidase activity and in unmedicated patients with chronic schizophrenia, plasma prolactin concentrations varied directly with platelet monoamine oxidase activity. No such relationship was found in normal subjects with high platelet monoamine oxidase activity. These data suggest that platelet monoamine oxidase activity reflects monoaminergic activity in the tubero-infundibular system, which in turn affects plasma prolactin concentrations. This relationship may be important in patients with low platelet monoamine oxidase activity, such as some chronic schizophrenics.

Blood Platelets↗
PubMed1979

Methodological issues in tardive dyskinesia research.

Research into tardive dyskinesia, an involuntary movement disorder secondary to chronic neuroleptic treatment, has so far produced conflicting results with no clear clinical applications. Heterogeneous diagnostic criteria, research designs, and rating scales, plus an emphasis on single-drug trials, are probably responsible. A strategy of developing pharmacological response profiles for patients participating in tardive dyskinesia research is suggested as one way to produce meaningful data, which may delineate pharmacological and clinical subtypes that would respond to different treatment approaches. Further suggestions are made about future trends in this area of research.

Clinical Trials as Topic↗
PubMed1977

Inhibition of dopamine synthesis in chronic schizophrenia. Clinical ineffectiveness of metyrosine.

According to the dopamine (DA) hypothesis of schizophrenia, there is a functional excess of dopaminergic activity within unspecified areas of the brain in schizophrenic patients. As a clinical test of this hypothesis, we administered metyrosine for three weeks to symptomatic chronic male schizophrenic patients who were maintained on suboptimal doses of neuroleptic agents. Metyrosine inhibits tyrosine hydroxylase, the rate-limiting enzymatic step in the synthesis of DA. No clinical improvement was observed, using the National Institute of Mental Health Inpatient Behavioral Rating Scale or the Brief Psychiatric Rating Scale. Central inhibition of DA synthesis by metyrosine was suggested, however, by (1) the development of extrapyramidal side effects and (2) a significant increase in plasma prolactin concentrations. Plasma chlorpromazine concentrations remained unchanged during metyrosine treatment. There was, nevertheless, a significant improvement on the scores of the Wechsler Adult Intelligence Scale Comprehension subtest, which measures judgment and common sense. This finding suggests that DA may be involved in the regulation of subtle psychological processes. The results are discussed in light of the DA hypothesis of schizophrenia and previous reports suggesting that metyrosine potentiates the antipsychotic effect of neuroleptics in schizophrenia.

Adult↗