Relapsing subacute demyelinating encephalomyelitis in rats during the course of coronavirus JHM infection.

Temperature-sensitive mutants of the murine coronavirus JHM induced a subacute demyelinating encephalomyelitis (SDE) in young rats. Neurological symptoms were associated with marked lesions of primary demyelination in the white matter of the central nervous system (CNS), and developing after an incubation time of several weeks to months. Many rats survived this infection and recovered completely from this CNS disease.

Sequence of murine coronavirus JHM induced neuropathological changes in rats.

Infection of 21-25-day-old rats with the murine coronavirus JHM was followed either by an acute encephalomyelitis (AE) or subacute demyelinating encephalomyelitis (SDE). The major neuropathological finding in AE, which developed within 6-12 days p.i.

Adaptation of coronavirus JHM to persistent infection of murine sac(-) cells.

Coronaviruses can establish persistent infections in the central nervous system of rodents, and these are associated with demyelinating encephalomyelitis. The effects of persistence on the virus are difficult to study in vivo but may have a crucial influence on the course of infection. We therefore produced a persistent infection in vitro using the neurotropic coronavirus JHM, in order to investigate the events underlying the establishment of such an infection and the adaptation of the virus to persistence.

Cloning of DNA corresponding to four different measles virus genomic regions.

Hybrid plasmids containing sequences corresponding to four different regions of the measles virus genome inserted in pBR322 were obtained by use of polyadenylated 50 S viral RNA as template for reverse transcription. One class of plasmids contains inserts corresponding to the 3' terminal region of the virus genome. The sequence of one of these inserts (605 nucleotides) partially overlaps with the cloned cDNA sequence corresponding to a part of the nucleocapsid protein (N) mRNA (M.

The application of monoclonal antibodies in the study of viruses.

This chapter discusses the applications of monoclonal antibodies in virology. A single monoclonal antibody can provide information on protein “relatedness,” structure, function, synthesis, processing, and cellular or tissue distribution and on the association among molecules. The use of monoclonal antibodies provides valuable insight into the working of the protein both as an enzyme and as a target for the host immune response, evolving in reaction to that response.

Virological and immunological aspects of coronavirus induced subacute demyelinating encephalomyelitis in rats.

Infection of rats with the murine coronavirus JHM led to acute or subacute encephalitis. Viral and host factors greatly influenced the outcome of the infection. A number of temperature-sensitive (ts) mutants was obtained which differed widely in their capacity to induce lesions of the central nervous system (CNS) in rats.

Defective translation of measles virus matrix protein in a subacute sclerosing panencephalitis cell line.

Subacute sclerosing panencephalitis (SSPE) is a slowly progressing fatal human disease of the central nervous system (CNS) that is associated with measles virus persistence. Virus nucleocapsids are present in the brain and the patient is in a state of hyperimmunization towards this agent. However, although all other structural polypeptides are recognized by the immune system, there is a markedly decreased antibody response towards virus matrix or membrane protein.

Adoptive transfer of EAE-like lesions from rats with coronavirus-induced demyelinating encephalomyelitis.

Viruses have been found to induce inflammatory demyelinating lesions in central nervous system (CNS) tissue of both animal and man, either by natural infections or after vaccination. At least two different pathogenic mechanisms have been proposed for these changes, a cytopathic viral infection of oligodendroglia cells with subsequent cell death, and a host immune reaction against virus and brain antigens. We now report the occurrence of cell-mediated immune reactions against basic myelin proteins in the course of coronavirus infections in Lewis rats.

Comparison of lytic and persistent measles virus matrix proteins by competition radioimmunoassay.

Measles virus matrix (M) proteins were compared by competitive monoclonal antibody-binding studies. Three strains of measles and of subacute sclerosing panencephalitis viruses were found to be identical in this way. The matrix protein formed by Edmonston strain virus during a persistent infection could be distinguished from that made in the lytic virus infection.

Purification and molecular weight determination of measles virus genomic RNA.

A purification procedure for genomic measles virus RNA, free of contaminating smaller RNA and of DNA, is described. Viral nucleocapsids were prepared from MA160 cells infected in spinner cultures with measles virus (Edmonston strain). Nucleic acid was extracted, treated with DNase and RNA sedimenting at about 50S in sucrose gradients was isolated.

Neurovirulence of murine coronavirus JHM temperature-sensitive mutants in rats.

The murine coronavirus strain JHM is highly neurotropic in rats and has a marked tendency to cause demyelinating central nervous system diseases after intracerebral inoculation. The clinical diseases observed range from an acute encephalomyelitis occurring within 2 weeks postinfection to a subacute demyelinating encephalomyelitis developing several weeks or months postinfection. Uncloned wild-type virus induced both acute and subacute diseases, whereas cloned JHM virus grown in tissue culture caused only acute disease without the pronounced lesions of primary demyelination.

Computer analysis of chromatin arrangement and nuclear texture in follicular thyroid tumours.

The differentiation of the thyroid glands follicular neoplasias into adenomas and carcinomas is currently done using the histological criteria recommended by WHO. This pilot study of 10 human follicular carcinomas and 10 folliculars adenomas demonstrates the possibility of a cytological classification using digital picture processing of high resolution cell images. Giemsa stained paraplast sections were scanned with a Colour-TV-camera, different channels were used with respect to staining and analyzing methods and computed with an image processing system.

Coronavirus JHM-induced demyelinating encephalomyelitis in rats: influence of immunity on the course of disease.

Disease processes of the central nervous system (CNS) accompanied by demyelination may be the result of a viral infection or the consequence of an immunopathological reaction directed against myelin. In acute viral infections, the infection of oligodendroglial cells, leading to cell destruction, may be the main mechanism for inducing this neuropathological lesion. In the case of a persistent virus infection in oligodendroglia cells, however, it is conceivable that functional impairment of oligodendroglia cells, or the induction of an immune reaction to the agent that may cross-react with brain antigens, could eventually cause demyelination.

Progressive multifocal leucoencephalopathy: detection of papovavirus JC in kidney tissue.

Cellular DNA of the kidney from a patient with PML was analyzed by reassociation kinetics for the presence of JC virus DNA. Various amounts of viral DNA sequences were detected in different areas of the kidney. The highest concentration (175 genome equivalents/cell) was found in the renal medulla and there were almost none in the renal cortex.

RNA-dependent RNA polymerase activity in murine coronavirus-infected cells.

The multiplication of murine coronavirus strains A59 or JHM in Sac(-) cells was unaffected by the presence of alpha-amanitin at concentrations which inhibited the host cell DNA-dependent RNA polymerase activity. In cells infected with the A59 virus strain, actinomycin D-resistant RNA synthesis could readily be detected by pulse-labelling with [3H]uridine; this virus-specific RNA synthesis was not induced in the presence of the protein synthesis inhibitor anisomycin. A new RNA-dependent RNA polymerase activity was detected in the large particle fraction of A59 virus-infected cells.

Subacute sclerosing panencephalitis: are antigenic changes involved in measles virus persistence?

Subacute sclerosing panencephalitis (SSPE) is a rare, fatal complication of measles virus infection arising years after acute measles. During this chronic disease process, characteristic measles virus inclusions are present in the cells of the central nervous system (CNS). During SSPE, infectious virus is not present either in the CNS or other tissues, but it has proved possible, in some cases, to rescue a measles-like virus by cocultivation techniques.

Specificity of IgM antibodies in acute human coxsackievirus B infections, analysed by indirect solid phase enzyme immunoassay and immunoblot technique.

The specificity of the IgM response in acute human coxsackievirus B infections was examined by indirect solid phase enzyme immunoassay and immunoblot techniques. IgM antibodies detected by ELISA were either strictly type-specific, type-predominant or group-reactive to coxsackieviruses B-1 to B-5. Homotypic and type-dominant responses were clearly correlated with the serotype isolated from the patient.

Relationships between monoclonal antibody-binding sites on the measles virus haemagglutinin.

Twenty-one monoclonal antibodies directed against the measles virus haemagglutinin have recently been obtained. These were known to fall into five groups, each defined by its effects on the biological functions of the H protein. A representative of each group was selected and examined by competitive radioimmunoassay in an attempt to deduce the relationships between antibody-binding sites on the antigen.

A comparative analysis of measles virus RNA by oligonucleotide fingerprinting.

Isolates from two cases of acute measles, one case of acute measles encephalitis and three patients with subacute sclerosing panencephalitis were compared. This comparison was based upon the electrophoretic analysis of T1 oligonucleotides from single-stranded, full-length RNA isolated from cytoplasmic nucleocapsids. Although all viruses have oligonucleotides in common, each isolate generated a unique pattern of oligonucleotides.