Helene W. Toolan

Lack of Oncogenic Effect of the H-Viruses for Hamsters

BECAUSE the H1 and RV2 viruses are somewhat similar in size to members of the oncogenic papova group, there has been considerable speculation about whether they, too, might have an oncogenic property. Toolan1 first reported that H-1 virus had not produced tumours in a small group of aged “mongoloid-type” hamsters injected at birth with H-1. Later, Kilham and Maloney3 noted that neoplasms had not been found in any of the species inoculated with RV when newborn, except for a few benign odontogenic tumours.

A Comparative Study of Amniotic Fluid, Maternal Sera and Cord Sera by Disc Electrophoresis.∗

Summary 1) Individual amniotic fluid proteins were quantitated by means of disc elec-trophoresis and immunodiffusion techniques, and proteins of the amniotic fluid were compared to those found in maternal and fetal serum. 2) The findings indicate that the proteins of the amniotic fluid originate at least partly from maternal serum. 3) Selective ultrafiltration on the basis of molecular size cannot explain apparent inhibition of the passage of haptoglobins and IgA into the amniotic fluid. Some additional mechanism, other than simple filtration, must be active. The authors would like to thank Dr. William Flood, Dr. Curtis Flory and members of the Putnam Memorial Hospital delivery room staff for their unfailing help and assistance in obtaining specimens for this study. Gratitude is also expressed to Dr. R. Woodworth of the University of Vermont for supplying purified haptoglobin 1-1.

Electron Microscope Study of Human NB and SMH Cells Infected with the Parvovirus, H-1: Involvement of the Nucleolus*

Summary The sequence of changes in human NB and SMH cells that occurred after H-1 virus infection, was studied with the electron microscope. The earliest alterations in NB cells after infection were detected in the nucleolus, after 31 hr. The pars fibrosa appeared devoid of its formed elements and was occupied instead with mainly ‘incomplete’ H-1 virus. The pars granulosa was more diffuse than normal and its nucleolar granules more sharply defined. A few ‘incomplete’ and ‘complete’ virus particles were scattered about the nucleus at approximately the same time. The cytoplasm was intact. Shortly thereafter, margination of the nuclear chromatin occurred. The nucleoli became increasingly condensed and shrunken, and apparently formed a doughnut-shaped body with condensed walls containing empty virus. Eventually, most of the nucleolar elements disappeared as the nuclei filled with complete and incomplete virus particles as well as occasional crystals possibly of protein nature. As the nucleolus disappeared, the cytoplasm disintegrated except for a few scattered mitochondria and some recognizable areas of endoplasmic reticulum which contained complete virus particles in linear array. Seventy-seven hr after infection when the nucleus had also broken down, virus was found associated with the disintegrated nucleus, within fragments of endoplasmic reticulum, and attached to thickened and adjoining plasma membranes of the few remaining, apparently uninfected cells. In SMH cells basically similar changes occurred except that the nucleoli appeared to fragment 31 hr after infection. Later, though most of the nucleolar sections disappeared, a few persisted and formed ‘nucleolar inclusions’ identical to those observed in NB cells. In contrast to the mixture of ‘complete’ and ‘incomplete’ virus observed in NB cells, the virus found in SMH cells was almost exclusively ‘empty’. Virus seen outside the nucleus, either in NB or SMH cells, appeared complete.

Relationship between Potentiation of H-1 Growth by Human Adenovirus 12 and Inhibition of the 'Helper' Adenovirus by H-1

Summary H-1 virus underwent an abortive cycle of replication in secondary human embryonic lung-cell cultures, characterized by formation of immunofluorescent H-1 antigen, without the production of infective virus. After mixed infection with adenovirus 12, approximately 30 to 40% of cells yielded infective H-1. A single infective adenovirus particle was capable of acting as helper. Comparison of the growth cycles of H-1 and ‘helper’ adenovirus showed that the two viruses had a similar latent period of about 24 hr. Inoculation of cells 24 hr before with adenovirus shortened the latent period for H-1 by at least 12 hr. Particles with serological characteristics of both viruses (mixed coats) were not found in virus yields from mixed infections. H-1 inhibited yields of adenovirus p.f.u. as well as virus antigens, provided that a low adenovirus input was used. The decrease in adenovirus yield was due to a reduction in the number of cells producing virus. With a high adenovirus input (10 or more p.f.u. per cell), no interference by H-1 was found. Maximal or nearly maximal potentiation of H-1 growth apparently occurred even when the H-1 caused virtually complete interference with formation of its ‘helper’ adenovirus.

Capsid Components of the Parvovirus H-1

Summary Disruption of purified H-1 virions with sodium dodecyl sulfate (SDS) and mercaptoethanol (ME) at 100° and pH 7.2 results in the appearance of one major and two minor migrating components on polyacrylamide gels. Molecular weights of 92, 000 (A), 72,000 (B), and 56,000 (C) were determined for the three moieties by coelectrophoresis of the dissociated virus with reference proteins of known molecular weight. Electrophoretic separation of 14C- or 3H-labeled virus polypeptides showed the relative amount of each radioactive component to be 15% (A), 75% (B) and 10% (C) of the total viral protein. Elution of the components from the gels, followed by hemagglutination assay against guinea pig red blood cells, indicated that component B was the antigenic component and structural protein. Amino acid analyses of H-1 virions revealed an overall acidic nature of the protein (acidic/basic amino acids = 1.75). The authors thank Miss Barbara Madden for technical assistance and Mr. Chad Shepis, University of Vermont, for performing the amino acid analyses.

Rh-D antibody titer in amniotic fluids

Abstract A study was made of Rh antibody titers in the amniotic fluids from 42 Rh-sensitized pregnancies. It was learned that the antibody titer of such fluid can be used as a reliable index of the severity of kemolytic disease in the fetus.

H-1 Virus Viremia in the Adult Hamster.∗

Summary Subcutaneous injection of H-1 virus in adult hamsters produced a cyclic-type viremia and the appearance of titratable HA-I and neutralizing antibodies while viremia was still present.

Effect of Proteolytic Enzymes on the Hemagglutinating Property of the Parvoviruses, H-1, H-3, and RV

Summary Three purified Parvoviruses (H-1, H-3 and RV), treated with various proteolytic enzymes, showed chemically-induced changes in their hemagglutination pattern only after exposure to papain which enhanced the values found. This increase was probably due to a dual effect of the papain: one on the virus itself by removing bound contaminants and, two, on the red cell membrane, probably by reducing the negative charge. Although the HA titer of virus was altered by papain treatment, no change in the SDS-acrylamide electrophoretic pattern of the capsid proteins or in infectivity was observed. The authors thank Miss Barbara Madden for technical assistance.

Effect of H-1 Virus Infection on RNA Synthesis In NB Cells

Summary The overall rate of incorporation of tritiated uridine into RNA in NB cells rapidly decreased after H-1 virus infection. This decrease in rate of RNA synthesis was apparently due to a decrease in number of cells synthesizing RNA. The 28S ribosomal RNA was selectively inhibited while the low molecular weight 4S RNA was selectively stimulated.

Studies on the red cell and antibody-reactive sites of the parvovirus H-1: effect of fixatives.

Summary Treatment of the Parvovirus, H-1, with the fixatives formaldehyde and glutaraldehyde have shown that: 1. Formaldehyde, even at 4% (1.33 M), had no effect on the red cell or antibody-binding sites of the virus. The infectivity of such samples, however, was abolished, indicating either a direct interaction with the DNA and/or that uncoating of the treated virions is impaired. 2. Glutaraldehyde at 0.25 and 0.5% (0.025 and 0.05 M) did not damage the HA or antigenicity, but further increases in bound glutaraldehyde lowered the HA and simultaneously, as determined by immunogel diffusion and SDS-electrophoresis, the ability of the virions to bind anti-H-1 globulin. Glutaraldehyde was as effective as formaldehyde in destroying H-1 infectivity. 3. The loss of HA activity of treated H-1 is dependent upon the temperature of the reaction. 4. Formaldehyde, by virtue of its lack of effect on H-1 HA activity and antigenicity at concentrations permitting reasonable preservation of morphology may be the fixative of choice for immunoelectron microscopy of H-1-infected cells. The authors thank Drs. K. A. O. Ellem and S. L. Rhode for their helpful discussion and M. Suzanne Hopkins, George Edick, and John Reed for their excellent technical assistance.