Biomedical subjects

S W Wright

Publications and source records attributed to S W Wright.

At least 73 records · Page 4Linked to original sources

PubMed1987

Alternative techniques of seeding cultured endothelial cells to ePTFE grafts of different diameters, porosities, and surfaces.

Attachment of 111Indium-oxine labeled cultured canine venous endothelial cells to expanded polytetrafluorethylene (ePTFE) grafts was evaluated in vitro. Three alternative seeding techniques were studied in grafts having different diameters, porosities, and surfaces, including: (I) manual milking of blood containing endothelial cells within the graft; (II) a two-step procedure of incubating grafts initially with blood and then with an endothelial cell suspension; and (III) mechanical spinning of grafts filled with blood containing endothelium. Method II had significantly higher cell attachment to the graft (11.6%) than did Method I (1.5%) or III (4.7%). A somewhat higher seeding efficiency was noted in 10-mm-I.D. grafts (11.6%) compared to 6-mm-I.D. grafts (6.3%). Different graft porosity, created by altering internodal distances, did not cause significant changes in cell attachment (10 microns, 13.4%; 30 microns, 6.3%; 90 microns, 16.0%). Fibronectin-coated surfaces, which should have enhanced cell adhesion, demonstrated a 6.0% cell attachment, a lower efficiency than the 11.6% observed with a blood coating alone. Acetone-soaked surfaces, which should have predictably exhibited less hydrophobicity, produced quite variable attachments (range 3.4 to 59.7%, mean 23.4%). In the present investigation the best seeding technique was method II, the two-step incubation procedure. Consistent differences were not noted with various ePTFE graft configurations or surfaces.

Animals↗

PubMed1987

The child with febrile seizures.

Febrile seizures are common in children. They are associated with disease outside of the central nervous system and are usually generalized, brief and self-limited. History and physical examination are usually sufficient to rule out central nervous system disease, and an extensive laboratory work-up is seldom indicated. Prophylaxis with antiseizure medications is only indicated in certain circumstances. The major risk in one febrile seizure is the increased likelihood of another.

Child, Preschool↗

PubMed1980

Purity of Chloroplasts Prepared from the Siphonous Green Alga, Caulerpa simpliciuscula, as Determined by Their Ultrastructure and Their Enzymic Content.

The ultrastructure and enzyme distribution in chloroplasts and other subcellular fractions isolated from the siphonous green alga, Caulerpa simpliciuscula, are described. The isolated chloroplasts were similar in appearance to those in the tissue from which they were derived, and in typical preparations 70% or more were intact. Chloroplasts which had lost their outer envelopes could be separated from intact plastids by centrifugation at low speeds through gradients of colloidal silica. Intact chloroplasts separated in this way retained their photosynthetic capacity and were impermeable to ferricyanide ions. The chloroplast preparations separated by differential centrifugation and refractionated using either discontinuous or continuous Percoll gradients contained non-chloroplast material. It was estimated that this amounted to a maximum of 10% of the mitochondrial population and 6% of cytoplasm extracted from the plant. The contaminating material surrounded the chloroplasts in a thin layer and was surrounded by a membrane.

Journal Article↗

PubMed1978

Properties of chloroplasts isolated from siphonous algae: effects of osmotic shock and detergent treatment on intactness.

Chloroplasts isolated from the siphonous green alga Caulerpa simpliciuscula (Turner) C.Ag. were shown to be resistant to dissolution by the nonionic detergent Teric-10 at concentrations as high as 0.3% (v/v) when treated at 0 C. There was little release of stromal enzymes under these conditions. These chloroplasts were disrupted by osmotic shock as shown by measurement of the release of both glucose-6-phosphate dehydrogenase and NADP-dependent glutamate dehydrogenase into the suspending medium. Ribulose-1,5-bisphosphate carboxylase, an accepted marker for chloroplast stromal protein in higher plants, was largely retained in the disrupted chloroplast following the osmotic shock. This is considered to be due to the location of a significant proportion of enzyme within the pyrenoid, which protects it from dissolution and causes it to behave as though it were an insoluble protein.

Journal Article↗

PubMed1976

Structure and Some Properties of Soluble 1,3-beta-Glucan Isolated from the Green Alga Caulerpa simpliciuscula.

The properties of the soluble beta-glucans formed during photosynthesis of the green siphonous alga Caulerpa simpliciuscula are described. There are two components in the soluble beta-glucan fraction. One has an apparent degree of polymerization of 37 glucose units and the other of 270 glucose units. The beta-glucan with the lower apparent molecular weight accounts for most of the mass in the beta-glucan fraction and is similar in properties to soluble laminarins reported in other algal and fungal species. The beta-glucan with the high apparent molecular weight contains most of the radioactivity accumulated in the beta-glucan fraction during short periods of photosynthesis.

Journal Article↗

PubMed1973