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Biomedical subjects

J Coll

Publications and source records attributed to J Coll.

At least 145 records · Page 8Linked to original sources

Pulpectomy procedure for deciduous teeth with severe pulpal necrosis.

Pulpectomies of deciduous teeth with severe pulpal necrosis should be considered as a possible treatment plan. Systemic and dental criteria have been devised to help the clinician to select cases in which successful results may be produced. A clinical success occurs when the pulpectomized tooth is painless, is firm in its alveolar socket, and is without a fistulous tract. Radiographically, any radiolucent area should be resolving with six months, and no pathologic root resorption should be observed. Research should determine whether pulpectomies may be done on children with severe systemic disease and should determine long-term consequences of underfilled and overfilled pulpectomies.

Dental Pulp Capping↗

Stimulation of heme accumulation and erythroid colony formation in cultures of chick bone marrow cells by chicken plasma.

A fibrin clot culture system with high plating efficiency is described for the growth of erythroid cells from chick bone marrow. Erythroid colonies grown in the absence of adult chicken plasma (spontaneous colonies) were either benzidine-negative or weakly benzidine-positive. Colonies grown in the presence of chicken plasma were 90% strongly benzidine-positive and 40% more abundant than spontaneous colonies. Plasma from anemic chickens was more effective than control plasma in inducing heme accumulation (heme-stimulating activity) and in increasing the number of erythroid colonies (colony-stimulating activity). Spontaneous colonies from 48-h cultures were transformed into benzidine-positive colonies by exposing them for 6-10 h to chicken plasma.

Anemia↗

Metabolically dependent and independent cell surface antigens.

In contrast to metabolically dependent tissue-specific cell surface antigens (MDA) which are available for reactions with antibodies only on surfaces of metabolically active cells, the availability of the universally distributed blood group A or Forssman-type antigens on cell surfaces was found to be independent of the metabolic activity of cultured cells. In case of the MDA, cytotoxic reactions were induced by antibodies alone, resulting in a disorganization of the cellular sheet without a significant release of radioactive label. Radioactive release in this cytotoxic reaction was increased by the addition of complement without additionally affecting the degree of cell sheet disorganization. In case of Forssman and blood group A antigens, such morphologically demonstrable cytotoxicity required complement, and the resulting pathology was always accompanied by extensive release of cellular contents. The ability of anti-MDA antibodies to induce cytotoxic reactions in the absence of complement may be related to a vital role of MDA in cellular function.

ABO Blood-Group System↗