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Biomedical subjects

C M West

Publications and source records attributed to C M West.

At least 145 records · Page 8Linked to original sources

Differential response of myofibrils and 10-nm filaments to a cocarcinogen.

Multinucleated myotubes containing large numbers of striated myofibrils and large numbers of longitudinally-oriented 10-nm filaments were treated with the cocarcinogen phorbol-12-myristate-13-acetate (PMA) for 24, 48 or 72 hours. The inhibitory effects of PMA on the accumulation of myofibrils was evident within 24 hours, and by 72 hours virtually all striated myofibrils had disappeared. In contrast, the density of the 10-nm filaments was greatly enhanced in these myofibril-depleted myotubes. These effects were not due to a generalized cytotoxicity, for PMA stimulated the replication of the presumptive myoblasts and fibroblasts present in these cultures. 24 hours after removing the PMA, these myotubes assembled a new set of striated myofibrils and the density of 10-nm filaments diminished proportionately.

Animals↗

Fibronectin alters the phenotypic properties of cultured chick embryo chondroblasts.

The state of chick embryo chondroblasts in culture was found to be sensitive to both fibronectin and another substance(s) (activity A) which could be extracted from chick embryo fibroblasts with 1 M urea or from conditioned medium. In the presence of either of these activities at concentrations of 25-150 micrograms/ml, chondroblasts, which normally grow as mixed cultures of floating and adherent cells, all immediately became attached to the tissue culture dish and spread. After several days, the morphology of these typically epithelioid cells became fibroblastic. This did not involve a selection process, since the effect was reversible. The synthetic program of these cells was also dramatically modified: the cultures no longer synthesized the chondroblast-unique type IV sulfated proteoglycan and began synthesizing alpha 2 collagen chains typical of fibroblastic or early limb bud cells. Fibronectin was resolved from activity A by gelatin affinity chromatography or gel filtration. Both activities were trypsin-sensitive. The two activities differed, however, on the basis of how the protein fractions in which they were found migrated in SDS-polyacrylamide gels, their specific activities and their effects on cell morphology and cell growth.

Animals↗

Contamination of intravenous infusion fluid: effects of changing administration sets.

Daily change of intravenous (i.v.) infusion administration sets has been recommended by the Center for Disease Control since 1973 to reduce the risk of infusion bacteremia. To evaluate this recommendation, we undertook a prospective, randomized, controlled trial that compared the rates of i.v.-associated bacteremia, in-use i.v. fluid contamination, and phlebitis in 300 patients whose administration sets were changed every 24 h with those in 300 patients whose administration sets were changed every 48 h. No i.v.-associated bacteremia occurred. Twelve of 600 infusions (2%) had positive infusion-fluid cultures: five in one group and seven in the other. Both groups had comparable rates of phlebitis. In this study population with low rates of fluid contamination, no benefit accrued from changing the administration sets every 24 h instead of every 48 h. In hospitals with low rates of fluid contamination, the routine changing of i.v. administration sets every 48 h will result in substantial financial savings.

Candida albicans↗

Serum genetic markers in a Newfoundland isolate with a familial aggregate of Hodgkin's disease.

Inherited genetic markers on the immunoglobulins and three other serum proteins were investigated in members of an isolated Newfoundland community. The frequencies found were compared with those from Europe. Whilst the incidence of the commonest variant forms were typically 'European', the occurrence of rare phenotypes pointed towards specific admixture from American Indians and Scandinavia. A possible contribution of these rare alleles, and of others, to pathogenesis in a familial aggregate of Hodgkin's disease within this community is discussed.

Gene Frequency↗

Identification of concanavalin A receptors and galactose-binding proteins in purified plasma membranes of Dictyostelium discoideum.

Two techniques have been modified to provide simple means for the identification of molecules which bind concanavalin A (Con A). Crossed immunoelectrophoresis was altered by replacing antibody with Con A, and receptors were identified by the precipitin arcs which they produced. Con A, tagged with fluorescein isothiocyanate, was also diffused into prefixed sodium dodecyl sulfate (SDS)-polyacrylamide gels, and additional receptors identified by fluorescence. More than 35 molecules in the plasma membranes of the cellular slime mold Dictyostelium discoideum which bind Con A were identified with these techniques. At least 12 of these diminish and 12 increase in importance as receptors during differentiation of the cells from the vegetative to the preculmination stage of development. In the course of these experiments, it was possible to confirm the presence of the galactose-binding protein discoidin, in the plasma membrane, by electrophoresing membrane proteins into an agarose gel. This lectin regains its sugar-binding activity after denaturation and electrophoresis in SDS.

Carrier Proteins↗

Ablepheron macrostomia syndrome.

Two male children are reported with similar features, including absent eyelids, eyebrows, eyelashes and hair, fusion defects of the mouth, expressionless facies, rudimentary external ears (but normal hearing), ambiguous genitalia, absent or rudimentary nipples, coarse dry skin with redundant skin folds and delayed expressive language development. The relationship of this syndrome to previously reported cryptophthalmos syndromes is discussed.

Child↗