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Biomedical subjects

R Rott

Publications and source records attributed to R Rott.

At least 181 records · Page 10Linked to original sources
PubMed1978

Alteration of the erythrocyte membrane during Newcastle disease virus-induced hemolysis.

In attempting to explain the mechanism whereby hemoglobin is released during NDV-induced hemolysis it was found that marker substances like albumin or myoglobin with diameters larger than 30 A are retained in the erythrocyte membrane, whereas low molecular weight material is released. This indicates that NDV-induced hemolysis does not result in the formation of membrane lesions but rather in the alteration of membrane permeability. A prerequisite for this process is the insertion of viral envelope components into the cell membrane. NDV-induced hemolysis can be enhanced by virus-specific antibodies and complement. In this case the release of marker substances is due to membrane lesions since large molecules also are released from the erythrocytes.

Animals↗
PubMed1978

Behavior alterations in tree shrews (Tupaia glis, Diard 1820) induced by Borna disease virus.

Intracerebral injection of Borna disease virus in tree shrews led to a persistent infection that sometimes resulted in clinical symptoms and/or specific alterations in the animals' behavior. Whereas infective virus in the brain and in the serum antibodies were always present after infection, only some of the animals showed signs of clinical disease and behavior changes. Animals kept in pairs showed especially obvious behavior alterations expressed as an exaggeration of all the components of normal social behavior. The division of the roles between males and females was seriously disturbed. The breeding behavior of females was especially impaired, although no stress factors were given and the animals were obviously in good physical condition. Some females that were maintained solitarily showed considerably exaggerated spontaneous locomotor activities (hyperactivity) 4 weeks after infection, followed by a phase of clinical neurologic symptoms (decline phase), spatial and temporal disorientation, and alterations in comfort behavior. Following a slow recovery the animals remained unusually docile and were much less timid than before infection. A recurrence of the clinical illness is possible, as shown by the occurrence of a second decline phase. All the behavior alterations can be interpreted as a disturbance in the balance of approach and avoidance. In paired animals this imbalance results in interference with normal sociosexual behavior. These alterations indicate that BD preferentially involves the limbic system, an interpretation supported by the results of neuropathologic investigations.

Animals↗
PubMed1978

The carbohydrates of influenza virus. II. Gas chromatographic analysis of glycopeptides derived from viral glycoproteins and mucopolysaccharides.

Two carbohydrate fractions can be obtained from egg-grown influenza virus after Pronase digestion followed by gel chromatography. One fraction contains glycopeptides (MW ca. 2000--2600) which represent the carbohydrate side chains of the viral glycoproteins. The constituent sugars of this material are fucose, galactose, glucosamine, and mannose, and their position within the side chain has been partially elucidated by methylation studies. The other fraction (MW greatest than 6000) appears to be mucopolysaccharide and is composed of fucose, galactose, glucose, galactosamine, and glucosamine.

Chromatography, Gas↗
PubMed1978

Metabolism of myoinositol in avian and mammalian cells infected with naked and enveloped DNA and RNA viruses.

The uptake of 3H-inositol into the pool of free inositol and its incorporation into the lipid phosphatidylinositol have been studied in various avian and mammalian cells infected by different viruses. In all the virus-cell systems investigated, virus infection results in a drastically reduced amount of free 3H-inositol about 3 to 5 h post-infection, demonstrable in the infected cells as compared to the mock-infected controls. In contrast, the incorporation of 3H-inositol into lipid can be enhanced, reduced, or not influenced at all, depending on the virus-cell system under observation.

Adenoviruses, Human↗
PubMed1978

Identification of a common antigen of herpes simplex virus bovine herpes mammillitis virus, and B virus.

In immunoelectrophoretic analyses one common antigen was demonstrated in antigen preparations from herpes simplex virus types 1- and 2- (HSV-1 and HSV-2), bovine herpes mammillitis (BHM) virus-, and B virus-infected cells solubilized by Triton X-100. The antigen was also demonstrated in solubilized purified HSV-1 and BHM virus. The common antigen was identified as antigen 11 of HSV-1 or HSV-2. Differences were found in the polypeptide composition of the related antigens when isolated from the four different herpesviruses, but a glycopolypeptide with a molecular weight of 125,000 was present in each of the four different antigen preparations, indicating that this polypeptide carried the common antigenic determinants.

Antigens, Viral↗
PubMed1977

Different pools of free myoinositol in chick-embryo cells as indicated by infection with Newcastle-disease virus.

Infection of chicken fibroblasts with Newcastle-disease virus indicates that cellular inositol is compartmented in at least two pools. Only the smaller pool is directly connected with the biosynthesis of phosphatidylinositol. Entrance of exogenous inositol into this pool is inhibited by phlorizin but not by the virus. Three hours after infection Newcastle-disease virus blocks the entrance of inositol from the small pool into one (or more) subsequent larger pool(s). About five hours after infection the virus enhances the catabolism of phosphatidylinositol in chicken cells and about seven hours after infection the permeability of the plasma membrane increases.

Animals↗
PubMed1977

The cerebrospinal fluid of rabbits infected with Borna disease virus.

Rabbits were inoculated intracerebrally with Borna disease virus infected brain suspension or tissue culture extracts. In 30 per cent of the diseased animals infectious virus was present in the cerebrospinal fluid (CSF). The CSF had increased numbers of lymphocytes and an elevation of the protein concentration, mainly due to an increase in gamma-globulins, was measured. The gamma-globulins were of oligoclonal character and reacted with a borna disease virus specific antigen of infected brains or tissue culture cells. The antibody titers in the CSF were of similar level to those in the serum. In comparison, those of the CSF of naturally infected horses always exceeded the serum titers. Injection of tracer substances revealed that no drastic damage to the blood-brain barrier was caused during the disease. The results suggest that antibodies detected in the CSF are locally produced. The significance of these findings for the pathogenesis of Borna disease is discussed.

Albumins↗
PubMed1977

[Correlation between structure and pathogenicity of myxoviruses (author's transl)].

Myxoviruses (ortho- and paramyxoviruses) possess on their surface two virus-specific glycoproteins, the functions of which are largely understood; These glycoproteins are synthesized on the rought endoplasmic reticulum, and during their transport to the plasma membrane on smooth intracellular membranes, they undergo modification through proteolytic cleavage. In this way, the orthomyxovirus hemagllutinin is converted from a high-molecular weight form (HA) into two smaller cleavage products (HA1 and HA2). With the paramyxoviruses, the glycoprotein F, which is responsible for fusion and hemolysis, is derived from proteolytic cleavage of a precursor, F0. Furthermore, with a few strains of avirulent NDV, a precursor of the hemagglutinin-neuraminidase complex, (HN0), has been identified which again, as a result of proteolysis, undergoes cleavage to HN. Whether cleavage takes place is as much dependent on the structure of the glycoprotein as on the host cell type. Proteolytic cleavage is indeed not necessary for virus particle production but is required for infectivity. Virus particles which possess the uncleaved glycoproteins may be activated by in vitro treatment with trypsin. As evidenced by experiments with orthomyxovirus recombinants, the glycoproteins alone do not determine the pathogenicity of the viruses. With paramyxoviruses, the pathogenic and apathogenic strains show clear differences in their host range spectrum which is directly related to the sensitivity of their glycoproteins twoard proteases. These observations provide an initial sketch for the molecular basis of infectivity and pathogenicity with myxoviruses.

Animals↗