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Biomedical subjects

M W Morgan

Publications and source records attributed to M W Morgan.

35 records · Page 2Linked to original sources
PubMed1980

The Maddox classification of vergence eye movements.

The classification of convergence as described by Maddox in The Clinical Use of Prisms is discussed. Maddox believed that the vergence system could be analyzed in terms of additive components designated according to their sensory origin: tonic vergence, accommodative vergence, reflex, or disparity (fusion), vergence, and proximal, or psychic, vergence. This description is brought into perspective with current-day descriptions of components of the binocular vergence system.

Accommodation, Ocular↗
PubMed1979

Cytotoxic drugs and the human adrenal cortex: a cell culture study.

Primary monolayer cultures of nonproliferating adult human adrenocortical cells have been used to screen 18 cytotoxic drugs used in cancer chemotherapy for direct effects on corticosteroidogenesis. None of the drugs tested, with the exception of 5-fluorouracil (5-FU) and its metabolite 5-fluorodeoxyuridine, showed significant activity at levels compatible with cortical cell viability and/or likely to be encountered during therapy. These two antimetabolites, however, resulted in a slow but long-lived reversible suppression of corticosteroidogenesis in both ACTH- and monobutyryl cyclic AMP-stimulated, as well as unstimulated cultures of human cells. Thus 10 micrograms/ml resulted in less than 80% inhibition after seven days treatment without any evidence of overt cytotoxicity. High-pressure liquid chromatography showed a suppression of all UV-absorbing steroids secreted. Examination of the ultrastructure of the treated cells showed significant changes in mitochondrial morphology, suggesting a possible site of action for the antisteroidogenic effects of 5-fluorouracil. These in vitro results suggest the possibility of adrenal suppression in vivo during long-term or high dose infusion 5-FU chemotherapy.

Adrenal Cortex↗
PubMed1977

Marginal aberrations of different bifocal-lens designs.

Marginal astigmatism and longitudinal chromatic aberration were measured (with a modified Vertometer) for +2-D bifocal lenses of different designs, base curves, and major-lens powers. At a reading level 20 deg below the pole of the major lens, deterioration of the optical image occurred and was created by the interaction of marginal astigmatism (tangential error) and lateral chromatic aberration (prismatic dispersion). Suggestions for selecting an optimal bifocal-lens design for different types of refractice error are presented.

Lenses↗
PubMedDate not supplied

Spirometric measurements in healthy Sierra Leoneans.

Pulmonary Function Tests(PFTS) are useful in the diagnosis and management of respiratory disorders. They provide an objective and quantitative measure of some aspects of brocho-pulmonary function. For meaningful interpretation of PFTs, an individual's own previous baseline results compared with current results are preferred, but in the absence of such baseline values, standard normograms may be used. Since lung function values are influenced by genetic, environmental, nutritional, and several other factors, it is important for every laboratory to use normograms that reflect these important factors. The results presented here are the first baseline data on pulmonary function (VC, FVC, FEV1, and FEV%) in a wide cross-section of healthy Sierra Leoneans.

Adolescent↗