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Biomedical subjects

E H Rubin

Publications and source records attributed to E H Rubin.

At least 73 records · Page 4Linked to original sources
PubMed1986

Imaging of brain activity and behavioral disorders.

Recent advances in brain imaging permit metabolic variables to be measured in psychiatric patients. These include regional cerebral blood flow, oxygen utilization, oxygen extraction and glucose utilization--all measures which reflect CNS energy utilization. The quantitative relationships between these metabolic parameters, neuronal activity, and higher cortical function are poorly understood. In evaluating the results of imaging studies, it is important to establish whether the reported changes correlate with episodic symptomatology or with a chronic disease process. Affective disorders exemplify conditions which are episodic, progress rapidly and respond to medication, making it difficult to identify consistent patterns of metabolic change. Thus unipolar subgroups have been described with both left and right metabolic predominance. On the other hand, imaging studies in dementia have consistently shown decreased glucose utilization, and more particularly poor verbal performance may go with reduced glucose uptake in the left temporal/parietal area. Although neuro-imaging studies are still at an early stage, the additional capacity to measure regional receptor distribution and kinetics using ligands tagged with positron emitters will open up new dimensions in the study of psycho-pathophysiology.

Alzheimer Disease↗
PubMed1986

Differential turnover of the subunits of ribonucleotide reductase in synchronized leukemia L1210 cells.

Ribonucleotide reductase catalyzes the rate-limiting step in the de novo synthesis of 2'-deoxyribonucleoside 5'-triphosphates that is required for DNA replication. The mammalian enzyme consists of two nonidentical protein subunits that are both required for enzyme activity. In leukemia L1210 cells, enriched in G1-phase cells by centrifugal elutriation, it was found that ribonucleotide reductase activity increased as the cells progressed to S-phase. The two subunits making up the holoenzyme did not increase coordinately. The nonheme iron subunit increased much more rapidly than the effector-binding (EB) subunit. The activity of the holoenzyme paralleled the level of the EB subunit, which was limiting. The half-lives of the holoenzyme and its subunits were determined in S-phase cells by treatment with cycloheximide. The half-lives of the holoenzyme and the nonheme iron and EB subunits, as determined by enzyme activity, were 3.5, 7.6, and 4 h, respectively. These half-lives are consistent with the data that indicate that the EB subunit is the limiting component in L1210 cells.

Adenosylmethionine Decarboxylase↗
PubMed1985

Limbic seizures, kindling, and psychosis: a link between neurobiology and clinical psychiatry.

This interplay between basic neurobiology and clinical psychiatry helps shape clinical thinking about behavioral disorders. At a basic science level, the potential exists for elucidating the functional anatomy and physiology of CNS regions involved in kindling. These studies should aid in understanding the basic mechanisms involved in this process, thus clarifying the processes involved in the associated behavioral changes. At a clinical level, improved techniques of CNS imaging such as provided by positron emission tomography should allow better elucidation of the functional anatomy related to specific psychiatric symptoms. By combining basic science and clinical research with careful clinical diagnosis and observation, we eventually should be able to understand many aspects of human psychopathology. Such understanding will lead to improved therapeutic strategies.

Animals↗
PubMed1985

Nortriptyline pharmacokinetics and plasma levels: implications for clinical practice.

The pharmacokinetics of TCAs are reviewed with particular emphasis on nortriptyline, the agent most extensively studied. The clinical uses of TCA plasma level-response studies are discussed in relationship to rational dosage adjustment to increase response rates and avoid iatrogenic toxicity. Other important topics discussed include the issue of active metabolites, single-dose prediction studies, and special considerations in treating the elderly and the medically ill.

Age Factors↗
PubMed1984

The behavioral and biochemical effects of lithium on dopaminergic agonist-induced supersensitivity.

Dopaminergic behavioral supersensitivity may be induced by chronic treatment with either dopaminergic agonists or antagonists. We demonstrate that the development of agonist-induced supersensitivity is resistant to chronic lithium exposure. Furthermore, chronic lithium alone enhances the stereotypic response to acute dopamine agonist administration and this effect of lithium summates with the behavioral augmentation caused by chronic amphetamine exposure. Although marked dopamine-related behavioral changes occur, chronic treatment with amphetamine, lithium, or both had no effect on levels of DA, DOPAC, HVA, and 3MT in either the striatum or nucleus accumbens. These results suggest that chronic amphetamine treatment with or without lithium does not affect presynaptic dopamine metabolism as assessed by metabolite levels. Furthermore, amphetamine-induced behavioral supersensitivity is not a simple function of changes in dopamine metabolism.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1979

Computerized discharge summaries.

A computerized, English text discharge summary system is described that is exclusively used for all patients discharged from a 150-bed rehabilitation hospital. The system covers all diagnostic categories. Cumulative statistics and other statistical routines are provided for clinical research, utilization review and administrative purposes.

Computers↗