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Biomedical subjects

G YOUNG

Publications and source records attributed to G YOUNG.

At least 19 recordsLinked to original sources
PubMed1959

The streptokinase-plasminogen system. I. Its effect on the pathogenicity of streptococci and other organisms for mice.

Human plasminogen, plasma, or serum increased the pathogenicity of six streptokinase-positive streptococcal strains for mice. Combinations of commercial streptokinase and plasminogen or streptokinase and plasma did not usually increase mouse mortality to a greater degree than did plasminogen or plasma alone, suggesting that the maximal effective amount of streptokinase was produced by the organisms. The pathogenicity of Salmonella paratyphi (fibrinolysin variable) and a Group D streptococcus (streptokinase-negative) was not increased by plasminogen, plasma, or streptokinase, whereas a combination of streptokinase and plasminogen, or streptokinase and plasma did significantly increase mouse mortality resulting from these organisms. Combinations of certain concentrations of streptokinase and plasminogen increased the pathogenicity of a fibrinolysin-negative staphylococcal strain for mice to a greater extent than did either substance alone. The observed results provide evidence that streptokinase, by an interaction with plasminogen, contributes to the pathogenicity of streptokinase-positive streptococci.

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PubMed1954

Experimental Staphylococcus infection in the hamster cheek pouch: the process of localization.

Small amounts of staphylococcus suspensions were injected into the cheek pouches of hamsters. Within 5 hours, the organisms were recovered from all outlying areas of the pouches, and in the following hours the entire structures showed vasodilation, edema, petechiae, and accumulation of leukocytes in the venules. Leukocytosis also occurred at this time. Between 24 and 48 hours, well defined abscesses developed at the sites of injection, and there was a sharp decrease in the bacteria in all other areas. From the 3rd day onward, organisms were only occasionally recovered from tissue outside the abscesses. At this period of localization, the generalized edema and petechiae also subsided, as did the leukocytosis. Localization of infection was not due to a walling off process, since the bacteria were disseminated through the entire pouches in the 1st few hours, but these organisms diminished rapidly, while those at the original injection sites continued to grow and reproduce for several days. Localization of infection appeared to be due to the inability of the bacteria carried away from the site of injection to reproduce. This in turn may have been due to dilution, to lack of sufficient toxin to produce a necrotic substrate, or to greater accessibility of these organisms to phagocytes.

Animals↗