A variety of biological products which included live and inactivated viral vaccines, inactivated rickettsial and bacterial vaccines, toxoids, and a multiple bacterial antigen product did not appear to be oncogenic for newborn hamsters following a single subcutaneous inoculation. The incidence of spontaneous tumors was approximately 4.7%, and this figure was not significantly altered by the inoculation of any of the test materials.

Adenoma↗

PubMed1972

Immunoperoxidase localization of herpes zoster virus and simian virus 40 in cell culture.

The immunoperoxidase technique was used in an electron microscopy study to localize the virions of herpes zoster virus and simian virus 40 in cell cultures. Intranuclear and intracytoplasmic virions of herpes zoster virus were easily and specifically identified due to intense staining by the finely granular, black reaction product. With simian virus 40, intranuclear virions were not stained, whereas intracytoplasmic particles appeared densely black. There was essentially no background staining. Advantages of this technique over the ferritin-labeled antibody method include simpler preparative procedures for reagents, greater penetrability of the antibody conjugate, and internal amplification which substantially improves the ability to localize sites of antigen-antibody reaction. We believe that the immunoperoxidase method can be successfully applied to a wide variety of problems involving viral antigens.

Animals↗

PubMed1972

Respiratory diseases in cyclophosphamide-treated mice. I. Increased virulence of Mycoplasma pulmonis.

Mice infected intranasally with Mycoplasma pulmonis were treated with cyclophosphamide, a potent immunologic suppressor. In place of a chronic smouldering infection with little mortality (2%), a rapidly lethal infection with high mortality (66%) was produced. M. pulmonis was able to be isolated from several organs during the course of the unmodified infection. In the infected animals treated with cyclophosphamide, dissemination occurred earlier, and higher titers of mycoplasma were found. Reconstitution experiments with spleen cells from previously infected animals reversed the effect of cyclophosphamide, indicating that immunity plays an important role in containment of the infection and eventual recovery.

Administration, Intranasal↗

PubMed1972

Respiratory diseases in cyclophosphamide-treated mice. II. Decreased virulence of PR8 influenza virus.

Mice infected intranasally with the PR8 strain of influenza virus were treated with cyclophosphamide, a potent immunologic suppressor. During the first week of infection, mortality in the unmodified influenza infection averaged 65%, whereas in those animals also treated with cyclophosphamide it averaged 22.5%. After the first week, the mortality rate in the infected cyclophosphamide-treated animals rose to that seen during the first week in the animals only infected. This decreased mortality in the first week was found despite the fact that the cyclophosphamide-treated and infected animals had higher virus titers which persisted longer, decreased circulating antibody, and a decreased interferon response. This delayed mortality appeared to be related to the finding of decreased cellular infiltration in the lungs of infected cyclophosphamide-treated animals.

Administration, Intranasal↗

PubMed1972