Biomedical subjects
Publications and source records attributed to R Carlson.
A case is reported in which the odontogenic keratocyst that appeared to be a dentigerous cyst associated with an impacted mandibular third molar was found histologically to demonstrate the keratinizing stratified squamous epithelium characteristic of these lesions in direct continuity with ciliated columnar epithelium.
A study of patients using the psychiatric emergency services of the Royal Ottawa Hospital was undertaken to determine their demographic and clinical characteristics, correlations between the two and comparisons with other studies. Special clinical forms of every fifth patient seen were analyzed and the data presented. These data are useful in the planning of and establishing and operating a psychiatric emergency service with an attached short-term inpatient unit, as well as assessing the feasibility and value of crisis intervention and brief psychotherapy in treating patients quickly.
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The breeding genetic distance measure of a single locus (Carlson & Welch, 1977) is extended to polygenic traits. For two populations with means -x and approximately x, theta(-x, approximately x) is defined as the size of the largest subpopulation with mean approximately x which can be (artificially) selected from a population with mean -x. The distance is defined as 1--theta(-x, approximately x). It is shown that theta(-x, approximately x) can be calculated from truncation selection and formulas (two loci) and tables (three and four loci) are given. Values for theta(-x, approximately x) based on a normal approximation are seen to be adequate for most cases. The measure is applied to a data example (human skin colour) and to a discussion of the idea of 'genetic inertia'.
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A model is proposed for measuring the genetic 'distance' between two populations having gene frequencies p and p. The measure of distance is based on a hypothetical selection process as follows: From population P a subpopulation P can be selected having gene frequency p. Let Po be the largest subpopulation yielding gene frequency p, then the relative size of Po to p--denoted by thetao (p,p)--is a measure of the 'closeness' of populations having gene frequencies p and p, and 1-thetao (p,p) whould be a reasonable measure of genetic distance. We show that the calculation of thetao (p,p) is a special case of the linear programming problem and derive algebraic expressions for thetao (p,p) in the two-allele case. We discuse some of the implications of the use of this measure of distance and compare it to others which have been proposed. We use linear programming methods to calculate genetic distance for three alleles.
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Reduction of effective blood flow represents the primary disturbance accounting for circulatory shock. Four categories of circulatory shock are identified: cardiogenic, hypovolemic, distributive, and obstructive. The pharmacology and clinical implications for treatment of shock with vasoactive drugs are reviewed in this context. Except for epinephrine, when it is used for treatment of anaphylactic shock, there is no specific indication for the routine use of alpha- or beta-adrenergic receptor agonists. These agents may increase blood pressure or cardiac output, but nutritive flow is not necessarily improved. Comparable limitations are observed with alpha-adrenergic receptor blocking agents. However, selective effects on the myocardium and on the resistance, exchange, and capacitance vessels may be advantageous as an interim and complementary measure. Since vasoactive drugs frequently intensify the fundamental defect accounting for perfusion failure, their selective rather than routine employment is mandatory.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.