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Biomedical subjects

R S el-Mallakh

Publications and source records attributed to R S el-Mallakh.

At least 19 recordsLinked to original sources
PubMed2000

Completed suicides and emergency psychiatric evaluations: the Louisville experience.

Suicide is one of the most serious outcomes of psychiatric illness, and the most extreme intervention (involuntary hospitalization) can be exercised if this event is likely. Despite this, the rate of suicide has remained fairly consistent at 1.1-1.4%. In an ongoing effort of identifying factors that can predict subsequent suicides, we retrospectively examined the records of individuals who completed suicides in Jefferson County, January 1997 through September 1998, and who were evaluated at the Emergency Psychiatric Service (EPS) at University of Louisville Hospital. Fifteen of the 132 (11.4%) subjects who completed suicide were evaluated at some point in time at EPS. Only 8 (6.1%) were seen within 60 days of the fatal event. This represents less than 0.1% of the total 9,469 patients seen at the EPS during this time period. No specific factors could be identified that predicted imminent suicide. Given the inaccuracy in being able to predict suicide, clinicians need to continue to be vigilant when assessing acutely distressed substance abusing or psychiatric patients.

Adult↗
PubMed1998

Alpha 2 isoform of the Na,K-adenosine triphosphatase is reduced in temporal cortex of bipolar individuals.

BACKGROUND: The pathophysiology of bipolar illness has been associated with changes in transmembrane ion flux and redistribution of biologically active ions. The recent identification of multiple isoforms of Na,K-adenosine triphosphatase (ATPase) alpha and beta subunits raises the possibility of altered pump isoform expression. METHODS: We determined Na,K-ATPase alpha subunit expression in postmortem temporal cortex gray matter from individuals suffering from bipolar disorder, schizoaffective disorder, schizophrenia, and matched normal controls. Quantification of isoform expression was accomplished via densitometric scanning of Western blots utilizing isoform-specific antibodies. RESULTS: Bipolar individuals exhibited a significant reduction in the abundance of the alpha 2 isoform of Na,K-ATPase compared to normal controls. Schizophrenic and schizo-affective brains were not significantly different from normal controls. CONCLUSION: These data suggest that previously observed abnormalities in regulation and distribution of ions in bipolar illness may be related to specific alpha 2 dysregulation.

Bipolar Disorder↗
PubMed1997

Meta-analysis of erythrocyte Na,K-ATPase activity in bipolar illness.

Sodium, potassium-activated adenosine triphosphatase (Na,K-ATPase) pump activity has been variously reported to be increased, decreased, or unchanged in bipolar patients. To explore this association we conducted a meta-analysis of the available literature. All papers containing data on erythrocyte Na,K-ATPase activity were reviewed independently by both authors. A meta-analysis of these data was accomplished by standard procedure. We found a significant mood-state-related decrease in Na,K-ATPase activity in both manic and bipolar depressed patients when compared to euthymic bipolar patients, but not when ill patients were compared to normal controls. The overall change can be characterized as small to moderate in magnitude.

Biomarkers↗
PubMed1997

Lithium prevents ouabain-induced behavioral changes. Toward an animal model for manic depression.

Both mania and bipolar depression have been associated with decrements in the activity of the sodium and potassium-activated adenosine triphosphatase (Na,K-ATPase) membrane pump. Although the role of this observation in the pathophysiology of bipolar illness is unclear, it has been proposed that this defect could be central to the pathogenesis of the illness. In an effort to test this hypothesis, the authors examined the efficacy of lithium pretreatment in attenuating behavioral changes secondary to acute administration of a single intracerebroventricular (i.c.v.) dose of the Na,K-ATPase-inhibiting compound, ouabain, in the Sprague-Dawley rat. Ouabain (10(-3)M) significantly decreased motor activity in automated activity monitors. Lithium pretreatment for 7 d totally prevented this effect. These preliminary data suggest that i.c.v. ouabain administration in the rat may prove to be a viable animal model for bipolar illness.

Animals↗
PubMed1997

Bipolar illness.

BACKGROUND: Within the past 5 years, several factors have altered our view of the diagnosis, prognosis, treatment, and genetics of bipolar illness. METHODS: Significant advances in these areas are reviewed. RESULTS: Diagnostic changes include establishment of symptom duration requirements that limit confusion with affective instability. Prognostic insights include the realization that illness likely begets illness and, conversely, that adequate control is probably instrumental in improving long-term prognosis. Therapeutic advances are marked by the Food and Drug Administration approval of divalproex for acute mania. CONCLUSIONS: Genetic and family studies suggest that (1) bipolar illness is a discrete condition, not related to unipolar depression; and (2) bipolar illness may manifest a phenomenon known as anticipation (worsening of the disease with succession generations), which may be related to a specific nucleic acid abnormality.

Bipolar Disorder↗
PubMed1997

Structure of music may influence cognition.

Classical music has been said to enhance cognition, which effect may be related to musical structure. 19 subjects who listened to highly structured music scored somewhat higher afterwards on cognitive performance than the 15 who listened to less structured music. Since this did not reach statistical significance, other as yet unidentified factors may also be involved.

Acoustic Stimulation↗
PubMed1996

Effects of chronic episodic hypoxia on monoamine metabolism and motor activity.

Chronic episodic hypoxia produces a wide array of cardiovascular dysfunctions in rats, including increases in blood pressure, heart rate, and sympathetic nerve activity. The action of episodic hypoxia might be related to low oxygen itself (hypoxemia) and/or combined with low CO2 (hypocapnia) resulting from hyperventilation. It is unknown whether or not the cardiovascular abnormalities are related to alterations in the central nervous system (CNS) that may be manifested as neurotransmitter and/or behavioral changes. In this study, we investigated effects of episodic eucapnic and hypocapnic hypoxia on monoamine metabolism in both CNS and adrenal glands, and on motor behavioral activity. Thirty-five male rats were divided into 3 groups. Experimental rats were exposed 8 h daily to varying fractional concentrations of inspired oxygen (FiO2) and carbon dioxide (FiCO2) for 35 days. These consisted of brief exposures (3-6s) of episodic (twice every min) eucapnic (3.5% FiO2 and 10% FiCO2, n = 6) or hypocapnic (3.5% FiO2 and 0% FiCO2, n = 14) hypoxia, or room air (21% FiO2 and 0.03% FiCO2, n = 15). Norepinephrine, dopamine, serotonin, and their metabolites in the hypothalamus, hippocampus, and adrenal glands were measured by high-performance liquid chromatography (HPLC). Spontaneous behavioral activity was assessed for 30 min by automated activity monitors. Episodic hypocapnic hypoxia produced a decrease in dopamine turnover and eucapnic hypoxia increased norepinephrine levels in the hypothalamus. Animals exposed to hypocapnic hypoxia also exhibited a consistent increase in horizontal (walking) and vertical (rearing) activity, as well as in total activity time. From these results, it is concluded that episodic eucapnic and hypocapnic hypoxia may affect metabolism of different neurotransmitters in the CNS.

Amines↗
PubMed1996

Nerve conduction velocity and H-reflex recovery in bipolar illness.

Bipolar illness may be characterized by dysregulation and dysfunction of biologically active ions and ion pumps, respectively. In an effort to examine whether purported physiologic abnormalities may have functional counterparts, nerve conduction velocities (NCVs) and H-reflex recovery were examined in 7 acutely manic, 11 euthymic bipolar, 13 remitted schizophrenic, and 6 normal control individuals. All electrophysiologic tests were clinically normal. However, euthymic bipolar patients had significantly slower NCVs than either manic or normal individuals. Percent decrement of H-reflex recovery was nonsignificantly increased in manic versus euthymic bipolar subjects. Data analysis suggests lithium was not responsible for these changes. These data indicate that different mood states in bipolar illness are associated with alterations in electroneurophysiologic function.

Adult↗
PubMed1996

Clues to depression in primary care practice.

Depression is a common but highly treatable mood disorder. Unfortunately, two thirds of depressed patients may never receive appropriate intervention. Because of individual and societal barriers to the diagnosis, depressive symptoms often go unrecognized. However, primary care physicians are in a unique position to surmount these obstacles by being alert to manifestations of the disorder. Treatment with antidepressant drugs, psychotherapy, electroconvulsive therapy, or a combination of these is very efficacious. The choice of method is based on such factors as history of previous response, severity of disease, concomitant medical illness, and patient preference.

Antidepressive Agents↗
PubMed1996

ECG intervals in acute bipolar and schizophrenic relapse.

Psychosis in general and acute relapse of bipolar illness, in particular, are associated with elevated catecholamine excretion, cardiovascular changes, and changes in intracellular calcium concentration. In an effort to determine if these changes result in observable ECG abnormalities, we retrospectively examined ECG parameters of acutely disturbed bipolar and schizophrenic patients. There were no discrete patterns of abnormalities, and no significant differences were observed between the two patient groups. Most ECG changes in acutely hospitalized bipolar and schizophrenic patients appear to be benign.

Acute Disease↗
PubMed1995

The Na,K-ATPase hypothesis for bipolar illness.

A cellular model for bipolar illness is presented. It is propounded that alterations in the activity of the membrane sodium- and potassium-activated adenosine triphosphatase pump (Na,K-ATPase) may be responsible for alterations in neuronal excitability and activity. Specifically, a reduction in Na,K-ATPase activity can lead to both mania and depression by increasing membrane excitability and decreasing neurotransmitter release, respectively. Supporting evidence is reviewed, and clinical and research implications are discussed.

Bipolar Disorder↗
PubMed1995

An animal model for mania: preliminary results.

1. In human bipolar patients mania and bipolar depression are both characterized by decreased membrane Na,K-AtPase activity. Additionally, digoxin neurotoxicity in patients frequently presents with symptoms of mania or depression. 2. These findings suggest that central nervous system Na,K-ATPase inhibition may play a pathophysiologic role in bipolar illness. 3. The authors tested this hypothesis by administering intracerebroventricular (i.c.v.) ouabain to rats at sublethal doses. The authors then measured behavioral activity as total square crossings in an open field. 4. Motoric activity was significantly increased by i.c.v. administration of 5 microliters of ouabain at 10(-3) M. This preliminary study suggests that i.c.v. ouabain administration may provide a useful animal model of mania that is based on observed biochemical changes in humans.

Animals↗
PubMed1994

Teaching psychopharmacology to psychology interns.

A group of psychology interns were given a brief course in psychopharmacology. In follow-up questionnaires from 14 doctoral psychologists 6 months and 2.7 years after graduation respondents stated that the course increased knowledge and confidence in their collaboration with physicians.

Humans↗