Biomedical subjects
A Keene
Publications and source records attributed to A Keene.
Interactions between dopamine D1 receptors and gamma-aminobutyric acid mechanisms in substantia nigra pars reticulata of the rat: neurochemical and behavioral studies.
RATIONALE: Several studies have shown that dopamine D1 agonists act on forebrain dopamine terminal regions to exert many of their behavioral effects. Yet, there is also a large number of D1 receptors in the substantia nigra pars reticulata (SNr), and these receptors are located mainly on terminals of gamma-aminobutyric acid (GABA)-ergic striatonigral neurons. OBJECTIVE: The present studies were undertaken to determine the behavioral and neurochemical effects of local administration of the D1 agonist SKF 82958 and to study the interactions between D1 and GABA mechanisms in SNr. METHODS: Microdialysis methods were used to characterize the effect of SKF 82958 on extracellular GABA, and several experiments studied the effects of nigral D1 stimulation on motor activity and investigated the behavioral significance of D1/GABA interactions in SNr. RESULTS: Local infusion of 10(-6) M SKF 82958 increased extracellular levels of SNr GABA, and this effect was blocked by co-infusion of the D1 antagonist SCH 23390. Bilateral SNr injections of SKF 82958 increased locomotor activity, and this effect was blocked by the GABA-A antagonist bicuculline. Intranigral bicuculline reduced motor activity, while the GABA-A agonist muscimol increased various motor activities in a manner similar to SKF 82958. CONCLUSIONS: The present results suggest that the D1 agonist SKF 82958 acts on D1 receptors in SNr to increase extracellular levels of GABA, and the increase in motor activity produced by nigral D1 stimulation is dependent on stimulation of GABA-A receptors. D1/GABA interactions in SNr are important for the modulation of basal ganglia output, which may have important implications for Parkinson's disease.
Ethical perceptions of parents and nurses in NICU: the case of baby Michael.
A case was used to examine ethical challenges in the neonatal intensive care unit from the perspective of parents and nurses. Discussion focuses on issues of treatment versus nontreatment, informed consent, and decision making. An integration of crisis intervention techniques and caring processes is presented for nurses to assist parents through the neonatal intensive care unit experience.
Cardiovascular and respiratory assessment in the office setting.
This article presents information for the office nurse about preoperative cardiovascular and respiratory assessment. Selected portions of the health history and physical examination are presented and their implications for successful patient outcomes discussed.
Perioperative assessment and nursing implications for the elderly.
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Ethical issues described by NICU nurses.
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Focus: on staffing advice for the new head nurse.
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The mandibular dental arch, part IV: Prediction and prevention of lower anterior relapse.
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Relationship between disruption of rhythmicity and reentrainment in surgical patients.
Urine samples for assay, temperature, heart rate, and blood pressure were collected daily at 2-h intervals from 11 consenting subjects undergoing abdominal surgery, as well as 10 age-and sex-matched control subjects. Alterations in level, and timing of circadian excretion of catecholamine metabolites, adrenal cortical hormones, sodium, potassium, creatinine, and vital signs following surgery were measured. Data were examined to determine if a relationship exists between the degree of circadian alteration and the subject's return to typical circadian profiles. The data suggest that certain circadian rhythms of hospitalized subjects were altered and uncoupled from external stimuli. In addition, subjects with less disruption in some variables following surgery regained rhythmicity more quickly than more disrupted subjects. These findings suggest that health professionals should individualize patient care to promote rhythmicity. In addition, patient assessment should consider individual circadian patterns and disruption following surgery.
Alterations in circadian excretion of urinary variables and physiological indicators of stress following surgery.
Alterations in level, timing, and coupling of circadian excretion of catecholamine metabolites, adrenal cortical hormones, sodium, potassium, creatinine, and vital signs in acute-care surgical patients were measured. Data were examined to determine if a relationship exists between the degree of circadian alteration and the subject's reentrainment to typical circadian profiles. Urine samples for assay, temperature, heart rate, and blood pressure were collected daily at 2-hour intervals from 11 consenting surgery subjects and 10 age- and sex-matched control subjects. The data indicate that certain circadian rhythms of hospitalized subjects were altered and uncoupled from external stimuli. These findings suggest that nurses (1) give individualized patient care to promote reentrainment recovery; and (2) refine nursing assessment to consider individual circadian patterns.