Subacute Spongiform Virus Encephalopathies Research Articles

Immunolocalization of scrapie amyloid (PrP27-30) in chronic wasting disease of Rocky Mountain elk and hybrids of captive mule deer and white-tailed deer

Scrapie amyloid-immunoreactive plaques are present in brain tissues of captive mule deer with chronic wasting disease (CWD), a progressive neurological disorder characterized neuropathologically by widespread spongiform change of the neuropil, intracytoplasmic vacuolation in neuronal perikarya and astrocytic hypertrophy and hyperplasia. We report here the immunolocalization of scrapie amyloid (PrP27-30) in plaques observed in brain tissues of Rocky Mountain elk ( Cervus elaphus nelsoni) and hybrids of mule deer and white-tailed deer ( Odocoileus virginianus) naturally affected with CWD. Similar findings have been shown in kuru, Creutzfeldt-Jakob disease, and Gerstmann-Sträussler syndrome in humans. Our data corroborate that CWD in Rocky Mountain elk and hybrids of mule deer and white-tailed deer belongs to the subacute spongiform virus encephalopathies (transmissible cerebral amyloidoses).

The senile dementias: A new model

Kuru and Creutzfeldt Jakob disease are fatal neurological disorders in humans that are transmissible to humans and other experimental animals. Largely because of their transmissibility the etiology of these diseases has been ascribed to infectious agents classified as “slow” or unconventional viruses. A related neurological disease in sheep called scrapie has also been ascribed to infection by slow viruses. Despite more than 20 years of intensive research no viruses or other infectious agents have ever been isolated or identified as the causative factors in these transmissible neurological diseases. The model presented below suggests that these “subacute spongiform virus encephalopathies” are not due to any infectious agent. Rather, I propose that they are caused by peptide hormones that may be transmitted from one individual to another in blood or other tissue. These hormones are postulated to activate genes in neurons whose proteins result in the observed pathology. It also is suggested that other non-transmissible human neurological diseases such as Alzheimer's disease may be due to endogenously produced peptide hormones that progressively activate genes responsible for the synthesis of amyloid proteins that are associated with neurological diseases.

The Clinical Picture in Slow Virus Diseases: A Review

The degenerative slow virus diseases are classified by whether the causative virus is conventional or unconventional. The conventional viruses are those whose elementary body consists of either RNA or DNA and is contained within a protein coat. These viruses cause slow infection because of an abnormality in the ability of the virus to replicate itself normally, as is the case in subacute sclerosing panencephalitis, or because of an abnormality in the host's immune response, as in progressive multifocal leukoencephalopathy. The conventional viruses have not yet been shown to be transmissible. The unconventional viruses are infectious agents which have properties not usually shown by conventional viruses. They induce slowly evolving diseases which share common neuropathic changes . These viruses cause the subacute spongiform virus encephalopathies. In humans they are responsible for kuru, the familial and sporadic forms of Creutzfeldt-Jakob disease and familial Alzheimer's disease. Similar transmissible diseases have been found to occur naturally in animals, and there is some feeling that in certain individuals, notably farmers, the virus causing Creutzfeldt-Jakob disease may be transmitted from sheep and goats (2).

Experimental Creutzfeldt-Jakob Disease Transmitted via the Eye with Infected Cornea

Scrapie of sheep, transmissible mink encephalopathy and Creutzfeldt-Jakob disease and kuru of man constitute the nosologic group of subacute spongiform virus encephalopathies.1 The possible transmi...

Experimental kuru in the gibbon and sooty mangabey and Creutzfeldt-Jakob disease in the pigtailed macaque. With a summary of the host range of the subacute spongiform virus encephalopathies.

The experimental host range for the slow virus infections causing subacute spongiform virus encephalopathies is enlarged in primates to include the gibbon for kuru, the pigtailed macaque for Creutzfeldt-Jakob disease, and the sooty mangabey for both diseases. The report is based on neuropathological evidence of the diseases in animals with preclinical lesions. A table lists all the species to which the subacute spongiform virus encephalopathies have been transmitted.

Antibody levels to herpes simplex type I, measles and rubella viruses in psychiatric patients.

The systematic search of aetiological agents from a variety of slowly progressing or subacute neurological diseases has revealed causative viruses or virus-like agents from kuru, Creutzfeldt-Jacob disease and other forms of presenile dementias, subacute sclerosing panencephalitis, progressive multifocal encephalopathy, and from many similar neurological diseases in animals (Gajdusek and Gibbs, 1973; Gajdusek, 1973). The first two diseases called subacute spongiform virus encephalopathies (Gajdusek and Gibbs, 1971) have many interesting features including heredo-familial occurrence and totally non-inflammatory neuropathology. Thus the epidemiology of these diseases is not typical for diseases with infectious aetiology, and the histopathological studies do not suggest the presence of extremely high-titred infectious material in brain cells.

Experimental Subacute Spongiform Virus Encephalopathies in Primates and Other Laboratory Animals

The host range of subacute spongiform virus encephalopathies is described. The asymptomatic incubation period and the duration of the illnesses in various species of animal hosts is discussed along with information on additional species of Old World and New World monkeys and the domestic cat, which have been shown to be susceptible to subacute spongiform virus encephalopathies.

Isolation and characterization of the subacute spongiform virus encephalopathies of man: kuru and Creutzfeldt-Jakob disease

Isolation and characterization of the subacute spongiform virus encephalopathies of man: kuru and Creutzfeldt-Jakob disease

Isolation and characterization of the subacute spongiform virus encephalopathies of man: kuru and Creutzfeldt-Jakob disease

Isolation and characterization of the subacute spongiform virus encephalopathies of man: kuru and Creutzfeldt-Jakob disease

Altered plasma membranes in experimental scrapie

The status spongiosus in the cerebral cortex of mice affected with two different strains of scrapie virus corresponded to focally swollen perikaryal cytoplasm of nerve cells and astrocytes, to swollen neuronal and astrocytic processes and to membrane-bounded vacuoles within pre- and postsynaptic neuronal terminals. The swollen cytoplasm contained uniformly dispersed, finely granulo-filamentous material. A few enlarged dendrites were filled with fragments of membranes or 350 A wide vesicular and tubular structures suggestive of virus particles. Ruptured plasma membranes and curled fragments of membranes were seen around cleared cytoplasmic regions and within membrane-bounded vacuoles. Neurons or astrocytes that lined affected cells or processes frequently showed similar changes. Confluence of swollen cells or processes occurred after dissolution of their adjacent plasma membranes. Astrocytes reacted to the injury by proliferation whereas nerve cells degenerated. The findings are compared to those seen in other subacute spongiform virus encephalopathies, i. e., mink encephalopathy, Kuru and Creutzfeldt-Jakob disease. The characteristic vacuolar degeneration of nerve cells in these diseases which is associated with fragmentation and accumulation of plasma membranes is discussed with reference to the peculiar properties of the scrapie virus.