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Biomedical subjects

D Brown

Publications and source records attributed to D Brown.

At least 1,027 records · Page 57Linked to original sources
PubMed1981

The delineation of the role of entry-level occupational therapy personnel.

The role assumed by occupational therapists and occupational therapy assistants during the first year of practice was delineated as part of an examination development project. The methods used to collect and analyze data obtained from several hundred therapists, assistants, and supervisors are described. A section of the results is presented to illustrate the differences and similarities found between the two levels of personnel.

Certification↗
PubMed1981

Endothelial repair of the canine cornea.

After transcorneal cryodestruction of 90% of the total corneal endothelium in the dog, the endothelial regenerative capacity was studied, using biomicroscopy, endothelial specular microscopy, pachometry, light microscopy, scanning electron microscopy, and autoradiography. Reestablishment of a continuous intact endothelial cell monolayer occurred at 6 weeks. Production of a thickened, multilaminar Descemet's membrane by endothelial and fibroblast-like cells was observed. Regenerating endothelial cells at the wound margin showed extensive formation of pseudopodia and incorporation of tritiated thymidine. Reendothelialization occurred by both mitotic division and enlargement and migration of remaining undamaged cells. The corneal endothelium of the young adult canine has marked regenerative potential, in contrast to that described for persons and cats.

Animals↗
PubMed1980

Developmental equations for the electroencephalogram.

Thirty-two linear regression equations predict the frequency composition of the electroencephalogram within four frequency bands, for four bilateral regions of the brain, as a function of age. Equations based on such data from large groups of healthy children in the United States and Sweden are closely similar. These equations describe the development of the electrical activity of the normal human brain, independent of cultural, ethnic, socioeconomic, or sex factors.

Adolescent↗
PubMed1980

Heterogeneity of toad bladder granular cell luminal membranes. Distribution of filipin-sterol complexes in freeze-fracture.

Glutaraldehyde-fixed toad urinary bladders were incubated with the sterol specific antibiotic, filipin, and the distribution of the resulting filipin-sterol complexes was studied in freeze-fracturing replicas. While the luminal membrane of some cells had a heavy, homogeneous labelling, most had clusters of filipin-sterol complexes scattered on an otherwise poorly labelled membrane. These clusters were seen to overlie cytoplasmic granules, which are found just beneath the luminal plasma membrane of this cell type, and which were always heavily labelled. These results suggest that (a) the granule membranes have a high cholesterol content and (b) sites of interaction between granule and luminal membranes might be enriched in cholesterol. In addition, filipin-sterol complexes were absent from vasopressin-induced particle aggregates on the granular cell luminal membrane.

Animals↗
PubMed1980

Isoproterenol-induced intramembrane particle aggregation and water flux in toad epidermis.

Stimulation of toad skin with isproterenol resulted in a dramatic increase in water flow, and in the appearance of aggregates of intramembrane particles in the apical membrane of granular cells of the replacement layer, just beneath the stratum corneum. This membrane structural modification appears to be a general prerequisite for the change in water permeability of vasopressin-sensitive epithelia.

Animals↗
PubMed1980

Modification of mitochondria-rich cells in different ionic conditions: changes in cell morphology and cell number in the skin of Xenopus laevis.

Xenopus laevis were kept in salt water (1.25% NaCl), distilled water, or tapwater for a month. Compared to the animals kept in tap water, the number of mitochondria-rich (MR) cells in the NaCl-adapted animals was significantly reduced, while it was increased in those maintained in distilled water. In addition, the MR-cells of NaCl-adapted animals lost their slender flask shape and developed large deposits of glycogen. The alteration of this cell type in conditions of high or low salinity may reflect a role of MR-cells in adaptation to different ionic environments.

Animals↗
PubMed1980

Cough-CPR: documentation of systemic perfusion in man and in an experimental model: a "window" to the mechanism of blood flow in external CPR.

Maintenance of arterial pressure and consciousness by vigorous coughing during ventricular fibrillation has been previously documented. Observations in 4 additional patients with unstable rhythms and in fibrillating dogs confirm that coughing: (1) produces an arterial pulse; (2) produces opening of the aortic valve; (3) generates forward blood flow; and (4) can maintain consciousness during circulatory arrest. The authors speculate that cough-induced systemic perfusion results from compression of the pulmonary vascular beds by a rise in intrathoracic pressure, the left heart acting only as a one-way conduit to the lower pressure extrathoracic vascular outlets. Recent data suggest that conventional CPR likewise produces blood flow by compression of the pulmonary vascular blood pool, and not by cardiac compression as previously thought.

Adult↗
PubMed1980

Specificity of initiation factor preparations from poliovirus-infected cells.

Crude initiation factor preparations from poliovirus-infected cells stimulated the translation of poliovirus RNA in vitro, but were inactive for the translation of host cell or vesicular stomatitis virus mRNA's. In contrast, similar preparations from either uninfected or vesicular stomatitis virus-infected cells supported the initiation of translation of host cell mRNA's and both viral mRNA's. These results reflect a specific alteration of some components(s) of the initiation factor preparation from poliovirus-infected cells which is consistent with the ability of the virus to inhibit the translation of host cell and vesicular stomatitis virus-directed protein synthesis.

HeLa Cells↗
PubMed1980

Similarities of membrane structure in freeze-fractured Xenopus laevis kidney collecting tubule and urinary bladder.

The collecting tubule of Xenopus laevis kidney is formed of two main types of cell: the socalled flask cells (or mitochondria-rich cells) and the remaining, more cuboidal epithelial cells. It has previously been shown that the flask-cell plasma membrane contains a population of elongated intramembrane particles similar to those found in mitochondria-rich cells of the toad bladder. It is now clear that the structure of the apical membrane of the remaining epithelial cells of the collecting duct is similar to the apical membrane of the amphibian urinary bladder granular cells. The P-face of the apical membrane has relatively few particles, whereas the E-face has many more. The E-face particles are of large diameter (16 nm), and many of them have an apical dense spot, which may represent a pit or depression in the particle. Such particles are not found on the lateral E-face below the level of the tight junctions. At the present time, the functional significance of these particles is unknown, but since vasopressin fails to elicit a hydrosmotic response in Xenopus laevis they are probably not involved in transepithelial water permeability. The fact that the different membrane specializations which characterize these mitochondria-rich and non-mitochondria-rich cells are found both in the bladder and the collecting tubule suggests that, at least in Xenopus, the 2 epithelia may share some common functions at the level of the apical membranes of their constituent cells.

Animals↗
PubMed1980

Membrane specialization in the rat epididymis. I. Rod-shaped intramembrane particles in the apical (mitochondria-rich) cell.

Following freeze-fracture of the rat epididymis, a population of cells whose apical, but not baso-lateral, plasma membrane contains elongated intramembrane particles was found in the initial segment. From their size, shape and distribution, these cells are assumed to be the so-called apical cells of this segment. Apical cells also contain the enzyme, carbonic anhydrase which, together with the presence of rod-shaped particle on their membranes, permits their classification as 'mitochondria-rich' cells, a specialized cell type found in some transporting epithelia. On the basis of these observations, we suggest that the apical cells may play a role in fluid and/or electrolyte transport in the initial segment of the epididymis.

Animals↗
PubMed1980

Comparison of econazole and clotrimazole in the treatment of vulvovaginal candidiasis.

The therapeutic effectiveness of econazole and clotrimazole was evaluated in 178 women with clinical symptoms of vulvovaginal candidiasis and positive laboratory findings for Candida. The patients were randomly assigned to treatment with either 1% econazole vaginal cream or 100-mg clotrimazole vaginal tablets, each used once daily at bedtime for 7 days. The mycologic cure rates were comparable in the 2 treatment groups. There was a low incidence of local adverse reactions with both drugs.

Adolescent↗