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Biomedical subjects

R M Davis

Publications and source records attributed to R M Davis.

At least 145 records · Page 8Linked to original sources
PubMed1979

Production of anti-rubratoxin antibody and its use in a radioimmunoassay for rubratoxin B.

Rubratoxin B was coupled to ovalbumin using 1-ethyl-3-(3-dimethyaminopropyl) carbodiimide HCl (ECDI) in high concentration at pH 8.0. Under these conditions it was possible to couple 13 moles of rubratoxin B per mole of ovalbumin. The conjugate was used for immunization of rabbits, and anti-rubratoxin antibody was produced. A radioimmunoassay for rubratoxin B was developed which could detect 0.1 microgram to 10 microgram of toxin using 0.21 microgram of [14C] rubratoxin (0.47 Ci/mole, 2.0 x 10(9) dpm/microgram) and 0.125 ml of anti-rubratoxin antibody.

Animals↗
PubMed1979

Production of [14C]rubratoxin B.

[14C]rubratoxin B was produced by culturing Penicillium rubrum Stoll for 13 days at 22 degrees C in medium containing [14C]glucose. The most efficient incorporation of glucose into rubratoxin occurred when Raulin-Thom medium enriched with 2.5% malt extract was supplemented with 2.5% added glucose. The presence of 1.0 mCi of radioactivity in 50 ml of medium with 2.5% added glucose resulted in the production of 38 mg of labeled, chromatographically pure rubratoxin with a specific activity of 0.47 Ci/mole.

Animals↗
PubMed1979

Development of the tibiotarsus in the chick embryo: biosynthetic activities of histologically distinct regions.

The dynamics of the histological changes which occur in the distal half of the tibial portion of the embryonic chick tibiotarsus from day 8 to day 18 of incubation are correlated with the capacities of histologically distinct zones to incorporate isotopic precursors into mucopolysaccharides and collagen. At the distal end of the tibia, which abuts the suture line formed by the fusion of the two tarsals with the tibia, there persists throughout embryonic development a narrow band of small, round or oval, rapidly dividing chondrocytes which synthesize chondroitin SO4 and collagen at low rates. Just proximal to this zone is a broader zone of flattened, disc-shaped chondrocytes which divide more slowly and are extremely active in chondroitin SO4 and collagen synthesis. Proximal to the zone of flattened chondrocytes is a zone of non-dividing, hypertrophied chondrocytes which are large and round and increase continually in size going from the distal to the proximal end of the zone. The biosynthetic activities of the cells in this zone fall sharply with their distance from the zone of flattened chondrocytes. Finally, there is a fourth zone, the marrow cavity, formed by a proximal to distal disintegration of the hypertrophied chondrocytes, starting at mid-diaphysis. The marrow cavity is surrounded by a shell of periosteal and intra-membranous bone which extends to the distal end of the zone of hypertrophied chondrocytes. Our data suggest that as the tibiotarsus grows in length the small, round rapidly dividing cells of the tibia differentiate first to flattened chondrocytes which synthesize matrix at a high rate and ultimately to low activity, hypertrophying chondrocytes. This sequence proceeds in a linear fashion.

Animals↗
PubMed1977

Lightning injuries.

The course of three patients apparently struck by lightning is reviewed. The circumstances of the injury and the power of the lightning discharge are uncontrollable variables affecting morbidity and mortality. Immediate cardiopulmonary resuscitation followed by careful clinical monitoring and aggressive treatment of involved organ systems will help most patients to complete recovery.

Adult↗
PubMed1977

Visualization of the medullary rays on excretory urography in experimental ureteric obstruction.

Excretory urography occasionally delineates striations of alternating density in the renal parenchyma. Experimental observations on a dog model of ureteric obstruction show that the dense striations have the same dynamic alterations as the obstructive nephrogram. They become progressively more dense to a plateau and then fade with relief of obstruction. Previous obstruction is shown to facilitate visualization of the striations presumably by having dilated the tubules. Previous obstructive episode, previous symptoms, or chronic obstruction were present in each of the clinical cases collected which show a similar striation pattern. We conclude that the dense striations represent shadows produced by hyperconcentrated contrast material which has accumulated in dilated collecting ducts or groups of ducts within the medullary rays.

Acute Disease↗
PubMed1977

Extraperitoneal inguinal endometriosis.

Two instances of extraperitoneal inguinal endometriosis are presented with a review of the previous reports of proven diagnosis. A high index of suspicion is needed to avoid needless prolonged observation. The diagnosis must be considered in any woman of childbearing age especially if the groin mass is associated with menstrual variability in size and in tenderness of the mass. Excision is curative and should result in permanent relief of pain.

Adnexa Uteri↗
PubMed1971

The national biomedical communications network as a developing structure.

The National Biomedical Communications Network has evolved both from a set of conceptual recommendations over the last twelve years and an accumulation of needs manifesting themselves in the requests of members of the medical community. With a short history of three years this network and its developing structure have exhibited most of the stresses of technology interfacing with customer groups, and of a structure attempting to build itself upon many existing fragmentary unconnected segments of a potentially viable resourcesharing capability. In addition to addressing these topics, the paper treats a design appropriate to any network devoted to information transfer in a special interest user community. It discusses fundamentals of network design, highlighting that network structure most appropriate to a national information network. Examples are given of cost analyses of information services and certain conjectures are offered concerning the roles of national networks.

Communication↗