Wayne A. Stenback

Biochemical Properties of a Defective Hamster C-Type Oncornavirus

A noninfectious hamster C-type oncornavirus (D9) associated with a spontaneous hamster lymphoma was characterized. The defective virions contained 70S RNA and the base composition was similar to that of a murine sarcoma-leukemia virus. With both endogenous and added templates, the virions were found to be deficient in DNA polymerase activity. These results suggest that DNA polymerase may be required for D9 infectivity.

Induction of Hepatomas in Hamsters by an Avian Adenovirus (CELO)

Summary Hepatomas were induced in approximately 4% of inbred LSH/LAK hamsters inoculated subcutaneously with CELO virus. The sera from these animals stained the CELO T antigen found in lytically infected chick kidney cells. The tumors contained hamster types A and C virus particles. The relationship between these indigenous hamster viruses and tumor induction by CELO virus is being investigated.

Hemagglutinating properties of CELO, an oncogenic avian adenovirus.

Chicken-embryo-lethal-orphan (CELO) virus, Phelps strain, agglutinated erythrocytes at 37 C. The hemagglutinating activity, which is a function of complete and incomplete virus particles, was sensitive to heat but not to pH. The soluble components of the virus were similar in sedimentation characteristics to those obtained from human adenovirus type 1. The effects of chemical and physical agents on CELO hemagglutinin, CELO infectivity, and red-cell receptors suggested that the last were protein in nature and that cell-virus attachment was mediated by amino groups on the virion. The attachment of virus to red blood cells via the penton projection was demonstrated by electron microscopy.

The immotile cilia syndrome — One cause of persistent upper respiratory tract infection

Four patients with persistent recurrent upper respiratory tract infections are presented. Electron microscopic studies of respiratory mucosal biopsies from these patients reveal ultrastructural abnormalities of cilia consisting of partial to complete loss of dynein arms, radial spoke disruption, and compound cilia. The concept of immotile cilia as an important cause of recurrent infections is receiving more attention. This study stresses the need for simple, rapid screening tests for cilial activity followed by electron microscopic evaluation in selected cases.

A Plaque Assay for Chick-Embryo-Lethal-Orphan (CELO) Virus

Summary A procedure was described for plaquing of avian adenovirus (CELO) in chick kidney cells. The media consisted of Eagles MEM with 2.5% fetal calf serum, 0.22% sodium bicarbonate and 0.04% protamine sulfate, in 1% Bacto agar. Using this medium, monolayers of chick kidney cells could easily be maintained for at least 12 days. Plaques could be counted on the 11th day, after addition of neutral red (0.04%) on the 10th day. An adsorption period of 3 hr at 3 7° gave optimal plaque counts.

Studies on an Oncogenic Avian Adenovirus (CELO) I. Biophysical Characterization

Summary CELO virus, from infected allantoic fluids, was treated with 1.0% sodium deoxycholate and 0.01% trypsin and centri-fuged to equilibrium in a rubidium chloride gradient. Two bands, at densities of approximately 1.34 and 1.29 g/cm3, were consistently found. Plaque titrations indicated that the band at 1.34 g/cm3contained the majority of infectious virus. Both hemagglutinating and CF activities were associated with these bands; however, soluble CF antigens were also present in the less dense regions of the gradients. The infectivity of purified CELO virions was heat stable and the virions did not contain the adenovirus group antigen.

Antibiotic and nonantibiotic ionophores can alter bacterial adherence to mammalian cells.

Abstract Epithelioid (HeLa) and fibroblastic (L) cells in culture incubated for 18 hr with the ionophores amphotericin B and amiloride were noted to bind significantly more and less bacteria, respectively, than control cells incubated without ionophores. These effects were related to dose and incubation length and were present at concentrations approximating those in vivo after administration of maximal doses of these drugs given to humans therapeutically. Electron microscopy of both receptor cell lines revealed increased length and number of cellular projections in the amphotericin-treated cells and flattening and loss of membrane individuality in the amiloride-treated cells. These findings could explain the differences in subsequent bacterial binding. The ionophores nifedipine and verapamil which block calcium transport in cells which have calcium channels did not alter bacterial binding to these receptor cells or bacterial binding to calcium channel-containing myoblasts (in culture). These data suggest that certain ionophores could alter bacterial colonization and infection in the host indirectly by altering bacterial binding; however, the clinical significance of these findings remains to be determined.