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Biomedical subjects

R T SMITH

Publications and source records attributed to R T SMITH.

At least 37 records · Page 2Linked to original sources
PubMed1958

Immunological unresponsiveness in rabbits produced by neonatal injection of defined antigens.

The phenomenon of immunological unresponsiveness induced in the neonatal rabbit by a single injection of a defined protein antigen, has been characterized semiquantitatively, and studies bearing upon the mechanism of such unresponsiveness have been presented. A single intraperitoneal injection at birth of 10 to 100 mg. BSA, HGG, ovalbumin, or a human macroglobulin, or an oral feeding of 100 mg. BSA, induced a state of unresponsiveness lasting at least 90 to 120 days. 100 mg. BSA given from birth to 17 days of age, but not later, produced unresponsiveness of 90 to 120 days' duration. Data are presented which show that the duration of unresponsiveness is finite and related to the amount of antigen given at birth, and that it may be indefinitely prolonged by repeated injections of antigen. Disappearance of injected antigen in the unresponsive animal was exponential with time, with no accelerated or immune phase. Administration of the antigen in adjuvants resulted in significant shortening of the duration of unresponsiveness. The transfer of immune cells to the unresponsive host while resulting in vicarious antibody formation, did not affect the underlying unresponsive state. Negative results of attempts to produce unresponsiveness to a variety of bacterial antigens are presented. The implications of the data are discussed, particularly in reference to the other experimental models of immunological tolerance, and to the various theories of acquired immunity. It is clear that any satisfactory theoretical explanation of acquired immunity will have to account simultaneously for the phenomena of immune tolerance.

Animals↗
PubMed1957

Repair of intracardiac defects; operation under direct vision with the aid of hypothermia or a pump-oxygenator; report of twelve cases.

The repair of intracardiac defects under direct vision by opening the heart to expose the operative field, with the aid of hypothermia or a pump-oxygenator, is now a practical clinical method. Twelve patients were operated upon by this method. In eight patients an atrial septal defect was repaired during total circulatory occlusion under hypothermia. The seven patients in this group who had uncomplicated atrial defects survived the operation and are doing well after a short follow-up period. One patient with an unrecognized, associated ventricular defect died at the time of operation. Four patients were operated upon during total cardiac by-pass with the DeWall bubble-oxygenator. The first three patients survived operation and are continuing to do well after a brief follow-up period. In the fourth patient an atrioventricularis communis was repaired by the reconstruction of an atrial and ventricular septum with a plastic prosthesis. This patient died at the end of operation.

Cardiovascular Abnormalities↗