PubMed Health⌕ Search

Biomedical subjects

A Kohn

Publications and source records attributed to A Kohn.

31 records · Page 2Linked to original sources
PubMed1977

Picorna- and togavirus infection of cells detected by gas chromatography.

Viral infection of cells causes chemical and metabolic changes, which can be detected by gas chromatography (GC) of ether extracts of supernatant fluids and cell homogenates before any significant damage to the cells is observable microscopically. The characteristic and specific GC patterns obtained from BHK-21 and Vero cell cultures infected with encephalomyocarditis, polio, echoviruses, and a togavirus make it possible to distinguish between these infecting viruses. The appearance of 1 or 2 compounds, represented by GC peaks with TR values of 302 and 677 seconds seems to be specific for these viruses. Other peaks found in the supernatant media 1-2 hours after infection probably represent cell constituents leaking into the medium as a result of damage to the cell membrane by the invading virus.

Arboviruses↗
PubMed1977

Increase in lipid fluidity of cellular membranes induced by adsorption of RNA and DNA virions.

Changes in the dynamic behavior of membrane lipids of mammalian cells induced by adsorption of animal viruses were quantitatively monitored by fluorescence polarization analysis with the aid of the fluorescent probe 1,6-diphenyl 1,3,5-hexatriene embedded in the surface membrane lipid core of intact cells. Adsorption of encephalomyocarditis, West Nile, and polyoma viruses to hamster (baby hamster kidney) and mouse (3T3) cells is accompanied by a rapid and significant increase in the degree of fluidity of membrane lipids of the infected cells. These changes in membrane fluidity, which are virus dose dependent, are inhibited by low temperature and by treatment of the cells before-hand with compounds known to block viral receptors on the cell surface. It is suggested that increase in membrane lipid fluidity, induced by the adsorption of virions, is an early event in the process of cell-virus interactions.

Adsorption↗
PubMed1976

Antibodies in blood and secretions of chickens immunized parenterally and locally with killed Newcastle disease virus vaccine.

In mammals the antibody activity in secretions is associated with the secretory IgA. This unique immunoglobulin plays a major role in immunity against infectious diseases of the alimentary and the respiratory tracts. We found a similar system of local immunity against Newcastle disease virus (NDV) in the fowl. Airway washings and bile globulins of chickens were examined by immunodiffusion and immunoelectrophoretic methods. No antigenic differences were found between the serum IgA and the secretory IgA of airway washings and of bile. The chicken IgA differs from mammalian IgA by lacking secretory component. Antibodies in the airway washings and in tears of chickens immunized by aerosol ir i.m. NDV vaccine (attenuated or inactive) were compared to serum antibodies produced by similar methods of administration. HI antibodies in secretions reached higher levels after aerosol vaccination than after i.m. administration, whereas in serum the situation was reversed. The antibody activity in airway washings and in tears is associated with IgA, while in serum the main antibody is IgG.

Aerosols↗
PubMed1975

The fate of protein subunits of parainfluenza (Sendai) virus after adsorption to NIL8 hamster embryo cells.

Adsorption of u.v.-inactivated Sendai virus on to NIL8 hamster cells causes fusion of the cells into polykaryocytes within 2 h. "Infected" cells were incubated at 37 degrees C for periods of 10 min to 8 h and their surface proteins iodinated with [125I] catalysed by peroxidase. Structural components of the viral envelope, such as haemagglutin-neuraminidase (HN) and probably also the fusion protein (F) were detected in the cell membrane for periods up to 4 h post infection.

Adsorption↗
PubMedDate not supplied

A passive hemagglutination test for detecting bovine serum albumin antibodies.

A microtiter passive hemagglutination test is described for detecting and titrating antibodies in chickens. Chicken erythrocytes are coated with antigen (bovine serum albumin = BSA) in the presence of 0.25% glutaraldehyde. Such sensitized erythrocytes are agglutinated in the presence of antibodies against BSA. The sensitivity and specificity of the test are not affected by salt concentrations in the range of 0.9-9%. This test measures the course of antibody response in chickens immunized with BSA.

Animals↗