[Intravital laboratory diagnosis of human subacute spongioid encephalopathies (Creutzfeldt-Jakob syndrome and amyotrophic leukospongiosis)]. / Prizhiznennaia laboratornaia diagnostika podostrykh spongioznykh éntsefalopatiicheloveka (bolezni Kreittsfel'da-Jakoba i amiotroficheskogo leikospongioza).

Methods aimed at the detection of causative agents in the CSF and peripheral blood lymphocytes are recommended for the use in intravital laboratory diagnosis of slow infections of the central nervous system. The results obtained enable recommending the biotest on guinea-pigs or indication of the causative agent of amyotrophic leukospongiosis (AL) in cell culture coupled with the punctate immunoenzyme assay for the diagnosis of AL. As to the diagnosis of Creutzfeldt-Jacob disease, it is suggested that the biotest on guinea-pigs and the punctate immunoenzyme assay may be used.

[The formation of infectious scrapie-like structures in the persistence of the agent of amyotrophic leukospongiosis in a brain cell culture]. / Formirovanie infektsionnykh skrepipodobnykh struktur pri persistentsii agenta amiotroficheskogo leikospongioza v kul'ture kletok mozga.

Electron microscopic analysis of specimens from guinea-pig brain cell cultures infected with amyotrophic leucospongiosis agent (belonging to "unconventional" viruses) revealed accumulation in the culture fluid of abnormal filamentous structures similar to scrapie-associated fibrils (SAF) differing in morphology. Most of these SAF-like structures 10-15 nm in diameter contained helically wound protofilaments with a repeat at certain intervals (50-150 nm). When these structures were inoculated into guinea-pig brain astrocyte cultures they produced dystrophic-destructive changes in some (25%) astrocytes, and their intracerebral inoculation to guinea pigs produced an experimental disease. The abnormal SAF-like structures were reisolated from the brains of the inoculated animals which indicated the relationship between these structures and infectivity.

[Study of the effects of amyotrophic leukospongiosis causative agent on neuroglia cells in vitro]. / Izuchenie vliianiia vozbuditelia amiotroficheskogo leikospongioza na neiroglial'nye kletki in vitro.

The influence of amyotrophic leukospongiosis (AL) causative agent on the ultrastructure of different types of cells of dissociated rat embryo brain and spinal cord cultures was studied. The AL agent belongs to the unconventional viruses (prions) and causes degenerative changes in the CNS. Large neurons and fibrous astrocytes were shown to be most sensitive. It was noted that the time of development and the degree of the dystrophic changes depend on the agent concentration. The destruction of cell membranes resulted in the pair neuron confluence. The formation of giant mitochondria with intramitochondrial inclusions was detected. It is supposed that the energetic apparatus of sensitive cells is primarily damaged by the infectious agent.

[Biochemical and immunological changes in guinea pigs with experimentally reproduced amyotrophic leukospongiosis]. / Nekotorye biokhimicheskie i immunologicheskie izmeneniia u morskikh svinok s éksperimental'no vosproizvedennym amiotroficheskim leikospongiozom.

Biochemical blood serum tests at different stages of amyotrophic leukospongiosis have shown differences in lactate and pyruvate levels as well as in lactate dehydrogenase activity, indicative of the increased oxidative exchange in sick guinea-pigs. It is suggested that intensified glycolysis is a compensatory-adaptive reaction in response to hypoxia due to respiratory disorders (spinal type) and degeneration and death of motoneurons. Leukospongiosis was accompanied by the decline in the complement level in the blood serum and production of antibodies to nervous fiber proteins.

[Development of laboratory diagnostic methods for slow infections of the human central nervous system caused by nonclassical viruses]. / Razrabotka metodov laboratornoi diagnostiki medlennykh infektsii tsentral'noi nervnoi sistemy cheloveka, vyzyvaemykh neklassicheskimi virusami.

The theoretical foundations of the laboratory diagnosis of Creutzfeldt-Jakob disease and amyotrophic leukospongiosis in living patients are discussed and practical diagnostic methods are proposed on the basis of the study of the biological properties of nonclassical viruses and the pathogenesis of slow infections of the central nervous system. The use of the retrobulbar method of infecting susceptible animals has permitted, besides a considerable decrease in the incubation period in modeling slow infections, the improvement of the in vivo biological test. Thus, as the result of the multiplication of non-classical viruses in the visual nerve and the retina, experimental animals develop retinopathy which can be detected 1.5-2.5 weeks after the animals are injected with the spinal fluid or blood taken from the patient under examination. To diagnose amyotrophic leukospongiosis, the in vitro biological test, based on the capacity of the causative agent for inducing a considerable (2- to 5-fold) increase in the mitotic activity of HEp-2 cells, has been developed. The comparative studies have shown the expediency of using the method for the detection of antibodies to nerve-fiber proteins as an additional test for the differential diagnosis of slow infections of the central nervous system.

[Experimental amyotrophic leukospongiosis in guinea pigs after retrobulbar infection]. / Eksperimental'nyi amiotroficheskii leikospongioz u morskikh svinok pri retrobul'barnom zarazhenii.

The results of modelling of amyotrophic leukospongiosis, a new form of slow infection of the human central nervous system, on guinea-pigs are reported. The animals were injected retrobalbulary with the virus-containing suspension. 1.5-2.5 weeks after the injection 70% of animals revealed signs of retinopathy during ophthalmoscopy. Two months later 90% of animals died, 40% of them exhibiting manifestations of the infection. Experimental amyotrophic leukospongiosis was histologically confirmed in all the dead animals. This method of modelling made it possible to shorten the incubation period to 1.0-2.0 months, while in intracerebral and intramuscular ways of contamination it was 3.5-8.2 and 5.3-11.1 months, respectively. The results evidence the involvement of the peripheral visual analyzer in the pathogenesis of experimental leukospongiosis at the early stages of its development.

[Characteristics of the etiological agent of human amyotrophic leukospongiosis]. / Kharakteristika étiologicheskogo agents amiotroficheskogo leikospongioza cheloveka.

Primary cultures of brain cells from a patient with amyotrophic leukospongiosis (ALSP) and animals with the experimentally reproduced disease yielded an agent which by its physicochemical and molecular biological properties was placed among nonclassical viruses, the agents of spongiform encephalopathies. The agent is small and resistant to a number of detergents, lipid solvents, oxidants, enzymes, UV irradiation, and heating. The role of the isolate in the development of ALSP is verified by experimental reproduction of the disease in guinea pigs inoculated either with a brain suspension from ALSP patient or with the purified and concentrated agent. The true nature of ALSP in experimentally inoculated animals was verified by clinical, morphological, and virological studies.