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Chronic wasting disease (CWD), a prion disease affecting cervids, has been known in North America (NA) since the 1960s and emerged in Norway in 2016. Surveillance and studies have revealed that there are different forms of CWD in Fennoscandia: contagious CWD in Norwegian reindeer and sporadic CWD in moose and red deer. Experimental studies have demonstrated that NA CWD prions can infect various species, but thus far, there have been no reports of natural transmission to non-cervid species. In vitro and laboratory animal studies of the Norwegian CWD strains suggest that these strains are different from the NA strains. In this work, we describe the intracerebral transmission of reindeer CWD to six scrapie-susceptible sheep. Detection methods included immunohistochemistry (IHC), western blot (WB), enzyme-linked immunosorbent assay (ELISA), real-time quaking-induced conversion (RT-QuIC) and protein misfolding cyclic amplification (PMCA). In the brain, grey matter vacuolation was limited, while all sheep exhibited vacuolation of the white matter. IHC and WB conventional detection techniques failed to detect prions; however, positive seeding activity with the RT-QuIC and PMCA amplification techniques was observed in the central nervous system of all but one sheep. Prions were robustly amplified in the lymph nodes of all animals, mainly by RT-QuIC. Additionally, two lymph nodes were positive by WB, and one was positive by ELISA. These findings suggest that sheep can propagate reindeer CWD prions after intracerebral inoculation, resulting in an unusual disease phenotype and prion distribution with a low amount of detectable prions.

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This work seeks to show a comparative analysis between dissociative anesthesia and inhalational general anesthesia used in intracerebral inoculations of mice. The intracerebral inoculation technique (challenge) is used in Biological Quality Control for the potency tests of the rabies vaccine and vaccines with a pertussis component. Intracerebral inoculation is an invasive and painful procedure for the animal, due to the increase in intracranial pressure and, therefore, it is essential to perform anesthesia before the procedure so that the inoculation is performed safely and painlessly, allowing greater comfort to the animal and less variability of the technique. For many years, dissociative anesthesia was the only approach used in laboratory animals, but with the development of studies and research, other approaches, such as inhalation anesthesia, have become increasingly used, providing a lot of safety and good results. Evaluating both anesthesia techniques, we observed that the animals submitted to inhalation anesthesia reached the adequate anesthetic plane more quickly, a quick recovery and low mortality, when compared to dissociative anesthesia. In conclusion, this work showed that for the intracerebral inoculation procedure, the inhalational anesthesia approach is more satisfactory.

Este trabalho busca mostrar uma análise comparativa entre a anestesia dissociativa e anestesia geral inalatória utilizada em inoculações intracerebrais de camundongo. A técnica de inoculação intracerebral (desafio) é utilizada no Controle de Qualidade Biológico para os testes de potência da vacina da raiva e vacinas com componente pertussis. A inoculação intracerebral é um procedimento invasivo e doloroso ao animal, devido ao aumento da pressão intracraniana e, por isso é fundamental a realização de anestesia antes do procedimento para que a inoculação seja realizada de forma segura e indolor, permitindo um maior conforto ao animal e menor variabilidade da técnica. Durante muitos anos a anestesia dissociativa foi a única abordagem utilizada em animais de laboratório, mas com o desenvolvimento de estudos e pesquisas, outras abordagens, como a anestesia inalatória, tornam-se cada vez mais utilizadas, fornecendo bastante segurança e bons resultados. Avaliando ambas as técnicas de anestesia, observamos que os animais submetidos a anestesia inalatória atingiram mais rapidamente o plano anestésico adequado, uma recuperação rápida e baixa mortalidade, quando comparada com a anestesia dissociativa. Em conclusão este trabalho mostrou que para o procedimento de inoculação intracerebral a abordagem da anestesia inalatória é mais satisfatória.

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We studied the localization and severity of morphological changes in CNS and internal organs of animals intacerebrally infected with a low-attenuated rubella virus strain "Orlov-14". The data obtained can be used as morphological criteria reflecting low level of attenuation of rubella virus strains to improve the control of the safety of attenuated strains of live rubella vaccines.

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In the United-Kingdom, ≈1 of 2,000 persons could be infected with variant Creutzfeldt-Jakob disease (vCJD). Therefore, risk of transmission of vCJD by medical procedures remains a major concern for public health authorities. In this study, we used in vitro amplification of prions by protein misfolding cyclic amplification (PMCA) to estimate distribution and level of the vCJD agent in 21 tissues from 4 patients who died of clinical vCJD and from 1 asymptomatic person with vCJD. PMCA identified major levels of vCJD prions in a range of tissues, including liver, salivary gland, kidney, lung, and bone marrow. Bioassays confirmed that the quantitative estimate of levels of vCJD prion accumulation provided by PMCA are indicative of vCJD infectivity levels in tissues. Findings provide critical data for the design of measures to minimize risk for iatrogenic transmission of vCJD.

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Transgenic mice (tg mice) that express the human poliovirus receptor (PVR), CD155, are susceptible to poliovirus and develop a neurological disease that resembles human poliomyelitis. Assessment of the neurovirulence levels of poliovirus strains, including mutant viruses produced by reverse genetics, circulating vaccine-derived poliovirus, and vaccine candidates, is useful for basic research of poliovirus pathogenicity, the surveillance of circulating polioviruses, and the quality control of oral live poliovirus vaccines, and does not require the use of monkeys. Furthermore, PVR-tg mice are useful for studying poliovirus tissue tropism and host immune responses. PVR-tg mice can be bred with mice deficient in the genes involved in viral pathogenicity. This report describes the methods used to analyze the pathogenicity and immune responses of poliovirus using the PVR-tg mouse model.

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Objective To develop RT-PCR for detection of TMEV and apply the method .Methods To design specific primers on the basis of GD VII ( GI:62039) genome sequences published in NCBI and establish RT-PCR.To verify the sensitivity and specificity of method after optimizing PCR .We infected 9 BALB/c mice intracerebrally and collected brain, heart, liver, spleen, lung, kidnet, cecal contents and serum samples the 6th day postinfection.The samples were tested by the TMEV RT-PCR.100 mouse cecal contents samples were also detected to apply the established method . Results The 371bp single band was amplified using GDVII as template .Sensitivity test showed that the RT-PCR method can detect as low as 0.69 pg/μL GDVII cDNA.There were no objective band amplified when encephalomyocarditis virus , lymphocytic choriomeningitis virus , Japanese B encephalitis virus , murine norovirus and normal mouse brain tissue were used as case-control .All infected mice showed symptom of different degrees such as depression and hind limb paralysis the 3th day postinoculation and two of infected mice died the 5th day postinoculation.Tissues such as heart, liver, spleen, lung, kidney, brain, cecal contents and serum were collected and tested for TMEV .All the brain samples were detected positive for GDVII and other tissues were all negative;The 100 cecal contents samples were tested and all were negative . Conclusions RT-PCR for TMEV GDVII strain can detect virus infection in mouse tissues efficiently and can be used as a powerful supplement for the national standard of lab animal .