Search PubMed⌕ Search

Biomedical subjects

D Tucker

Publications and source records attributed to D Tucker.

At least 73 records · Page 4Linked to original sources
PubMed1966

Odor discrimination in pigeons.

An operant procedure was employed to investigate odor discrimination in the pigeon. Amyl acetate concentrations of 6-percent saturation in air, and lower, when paired with electric shock markedly reduced key-pecking during the odor stimulus period. Sectioning the olfactory nerves eliminated this selective suppression behavior. After the operation, the suppression was again conditioned when the concentration of amyl acetate was increased to 15-percent saturation in air. This is theoretically possible through mediation by the trigeminal system.

Acetates↗
PubMedDate not supplied

CT diagnosis of emphysematous pyelonephritis.

Emphysematous pyelonephritis is a rare but frequently fatal complication of renal infection in the diabetic patient. The diagnosis is usually only made roentgenographically. We present a patient in whom the initial plain abdominal film was normal and renal sonogram was nondiagnostic. The correct diagnosis was made only on the subsequent CT scan.

Diabetic Nephropathies↗
PubMedDate not supplied

Inverse relationship of urinary cyclic GMP to blood pressure reactivity in the CARDIA study: vasodilatory regulation of sympathetic vasoconstriction. Coronary Artery Risk Development in Young Adults.

OBJECTIVE: To determine whether urinary cyclic GMP (cGMP), which mediates the actions of the vasodilators nitric oxide and atrial natriuretic factor, is inversely related to blood pressure (BP) reactivity. In previous work, we found that urinary cGMP was inversely related to diastolic BP, but cGMP levels were higher among individuals presumed to have increased adrenergic activity, increased reactivity, and increased risk of hypertension (blacks, individuals with a family history of hypertension). METHOD: We measured 24-hour urinary cGMP levels in a substudy of 529 individuals in the Coronary Artery Risk Development in Young Adults (CARDIA) study; the sample was 23 to 35 years of age and approximately balanced for race (black/white) and gender. BP reactivity to stressors (video game, star-tracing, cold pressor) was tested 3 years earlier. Baseline BP was included as a covariate in all analyses. RESULTS: Diastolic BP reactivity to cold pressor was inversely related to cGMP excretion (p < .05); the relationship was strongest among black women with a family history of hypertension (partial r = -.33, p < .01). Systolic BP reactivity to star-tracing was also inversely related to cGMP (p < .01); the relationship for both star-tracing and video game stressors was strongest among black men (partial r values = -.25 and -.24, respectively; p values < .01). CONCLUSIONS: The results indicate that vasodilatory activity may impact the BP response to stress through modulation of adrenergic activation, particularly among blacks.

Adolescent↗
PubMedDate not supplied

1,3-Dinitrobenzene-induced encephalopathy in rats.

Exposure to 1,3-dinitrobenzene (1,3-DNB) in humans induces methaemoglobinaemia, nausea and nervous symptoms. When given to conventional rats, twice-daily oral doses of 10 mg kg-1 1,3-DNB produce methaemoglobinaemia and frequently ataxia after four or five doses. In germ free rats given only a single oral dose of 20 mg kg-1, similar symptoms occur but are of more rapid onset. Light and electron microscope examinations reveal an acute thiamine deficiency-like lesion in the brain stems of both ataxic and apparently normal rats. Bilaterally symmetrical vacuolated lesions involve cerebellar roof, vestibular and superior olivary nuclei and the inferior colliculi. Frequent petechial haemorrhages are associated with these lesions, the erythrocytes usually being limited to enlarged Virchow-Robin spaces but sometimes spreading more widely. The primary cellular targets appear to be astrocytes, oligodendrocytes and vascular elements with secondary neuronal involvement. It is suggested that 1,3-DNB interferes with intracellular redox mechanisms resulting in impaired glucose oxidation.

Animals↗
PubMedDate not supplied

Developing a plan to evaluate the use of nursing conceptual frameworks.

Five hospitals in the Metropolitan Toronto area have introduced a nursing conceptual framework as the basis of practice in their agencies. A research team representing the hospitals and the University of Toronto has developed a comprehensive plan to evaluate the impact of using a nursing framework on nursing practice. This paper describes the selection of variables to be studied and the ways selected to measure them. A series of papers will follow describing the establishment of psychometric properties of the instruments and the results of the pre-test phase. Although this paper describes a process that began some time in the past, the authors have kept current the literature on the subject and the most current references are included in this paper.

Humans↗