La fantástica historia de la increíble prion / The fantastic story of the incredible prion

Resumen Desde el scrapie de la oveja a la encefalopatía espongiforme bovina y desde el kuru a la enfermedad de Creutzfeldt-Jakob, tenaces investigadores buscaron los misteriosos agentes de estos desórdenes neurológicos, hasta que Stanley Prusiner descubriera y describiera las priones en los ochenta, obteniendo el Premio Nobel en 1997. Pero, este no fue el final de esta fantástica historia de la increible proteina designada prion por Prusiner, porque ahora, la investigación en neurociencia ha encontrado proteínas prion-like jugando un importante papel en la génesis de la memoria a largo plazo.

Abstract From the scrapie of the sheep to the bovine spongiform encephalitis, and from the kuru to the Creutzfeldt-Jakob disease, tenacious investigators searched for the mysterious agent of these neurological disorders, till Stanley Prusiner discovered and described the prion in the eighties, wining the Nobel Prize in 1997. But this was not the end of the fantastic history of the incredible protein designed prion by Prusiner, because now the investigation on neuroscience has founded prion-like proteins playing an important role in the genesis of the long-term memory.

Diagnóstico diferencial das doenças neurológicas dos bovinos no estado do Paraná / Differential diagnosis of neurologic diseases of cattle in the state of Paraná

O objetivo deste trabalho foi identificar as doenças neurológicas que acometeram bovinos no estado do Paraná entre os anos de 2009 e 2015. A investigação aconteceu, preferencialmente, nas propriedades rurais onde os casos ocorreram. Foram registradas as informações sobre a evolução das doenças nos bovinos afetados do rebanho, e os prováveis fatores de risco foram identificados. Todos os procedimentos de exame físico geral e neurológico foram realizados sistematicamente para a caracterização da síndrome neurológica presente. Amostras de sangue e de líquor foram colhidas para a realização de exames laboratoriais. De acordo com o tempo de evolução e com a gravidade dos sinais clínicos observados, os bovinos doentes eram mantidos vivos para acompanhamento da evolução ou da resposta ao tratamento, ou eram submetidos à eutanásia seguida de necropsia. Fragmentos do sistema nervoso e dos demais órgãos foram colhidos para exame histopatológico. O exame de imunofluorescência direta e a prova biológica em camundongos foram realizados em todos os bovinos que morreram, com a finalidade de confirmar ou descartar o diagnóstico de raiva. Métodos laboratoriais específicos das rotinas de virologia, bacteriologia e toxicologia foram empregados, como complementares, para o estabelecimento do diagnóstico diferencial. Foram investigados 236 bovinos com doença neurológica, sendo 85 casos de ocorrência individual e 151 casos distribuídos por surtos que ocorreram em 79 rebanhos. As encefalopatias (180/236; 76,2%) predominaram sobre as mielopatias (27/236; 11,4%). As doenças inflamatórias determinadas por infecções (98/236; 41,5%) e as doenças tóxicas (91/236; 38,6%) foram as principais, enquanto as causas degenerativas (10/236; 4,2%), metabólicas (9/236; 3,8%), físicas (9/236; 3,8%), neoplásicas (4/236; 1,7%), e os defeitos congênitos (1/236; 0,4%) ocorreram menos frequentemente. Os casos inconclusivos somaram 5,9% (14/236). A meningoencefalite por BoHV-5 e a raiva foram as doenças de frequência maior e podem ser consideradas as mais importantes. Dentre as causas tóxicas, as intoxicações por plantas se destacaram (63/91; 69,2%) e foram responsáveis por 26,6% de todos os casos. Destacaram-se ainda a polioencefalomalácia, a meningoencefalite trombótica por Histophilus somni e o botulismo. Essas informações contribuem para que os médicos veterinários adotem condutas mais efetivas de diagnóstico e de prevenção, e são valiosas para o sistema oficial de vigilância epidemiológica do estado.(AU)

The aim of this study was to identify the neurological diseases that affected cattle in Paraná state between the years 2009 and 2015. The investigation took place, preferably, in the farms where cases occurred. Information on the evolution of the diseases in the affected cattle of the herd was recorded, and the probable risk factors were identified. All general and neurological examination procedures were performed systematically for the characterization of the neurological syndrome in each case. Samples of blood and CSF for laboratory exams were also collected. According to the evolution features and the severity of the observed clinical signs, the diseased cattle were kept alive to follow the progress of the disease, or were submitted to euthanasia followed by necropsy. Fragments of tissues from nervous system and other organs were collected for histopathological examination. Direct immunofluorescence test and biological test were performed on all the cattle that died, in order to confirm or rule out the diagnosis of rabies. Specific virology, bacteriology and toxicology laboratory methods were used as complementary exams in order to establish differential diagnosis. A total of 236 cattle with neurological disease were investigated, 85 cases of individual occurrence and 151 cases distributed by outbreaks that occurred in 79 herds. Encephalopathies (180/236, 76.2%) predominated over mielopathies (27/236, 11.4%). Inflammatory diseases caused by infections (98/236, 41.5%) and the toxic diseases (91/236, 38.6%) were the main causes, while degenerative (10/236, 4.2%), metabolic (9/236; 3.8%), physical (9/236, 3.8%), neoplastic (4/236, 1.7%), and congenital defects (1/236, 0.4%) occurred less often. The inconclusive cases were 5.9% (14/236). BoHV-5 meningoencephalitis and rabies were diseases of higher frequency and may be considered the most important. Among the toxic causes, plant poisonings were highlighted (63/91, 69.2%) and were responsible for 26.6% of all cases. Polioencephalomalacia, thrombotic meningoencephalitis caused by Histophilus somni and botulism were also highlighted. This information helps veterinarians to adopt more effective diagnostic and preventive approaches and is valuable to the state's official epidemiological surveillance system.(AU)

La encefalopatía de la prematuridad, una entidad nosológica en expansión / Encephalopathy of prematurity, a developing nosological entity

Con frecuencia se emplean los términos leucomalacia periventricular, daño a la sustancia blanca y encefalopatía de la prematuridad como sinónimos; sin embargo, no son exactamente lo mismo. Se realiza esta revisión con el objetivo de fundamentar la consistencia del término encefalopatía de la prematuridad, a partir de una actualización sobre su fisiopatología, diagnóstico y pronóstico. La leucomalacia periventricular tiene 2 componentes principales, uno macroscópico quístico y otro microscópico, que puede ser focal o difuso. El daño a la sustancia blanca es el hallazgo neuropatológico más común de parálisis cerebral en los recién nacidos pretérminos, que identifica cualquier anormalidad en la sustancia blanca. La encefalopatía de la prematuridad, en cambio, es un término mucho más abarcador, porque en su origen parecen tener importancia los trastornos destructivos primarios y los relacionados con el desarrollo cerebral. Su fisiopatología se ha tratado de explicar mediante 2 modelos teóricos: el infeccioso-inflamatorio y el hemodinámico. Para su diagnóstico resultan necesarias la evaluación neuroimaginológica y la del neurodesarrollo, en la que a menudo se diagnostica la presencia de parálisis cerebral o trastornos del desarrollo intelectual, aisladamente o en asociación. Es muy probable que la encefalopatía de la prematuridad tienda a afianzarse cada día más como una entidad nosológica independiente, dadas sus implicaciones médicas y sociales.

Some terms such as periventricular leukomalacia (PVL), white matter damage (WMD) and encephalopathy of prematurity are used as synonyms; however, they are not exactly the same. This review was aimed at substantiating the consistency of the term encephalopathy of prematurity, on the basis of its physiopathology, diagnosis and prognosis. Periventricular leukomalacia has two main components, one macroscopic cystic and the other microscopic one which can be focal or diffuse. The white matter damage is the most common neuropathological feature of cerebral palsy in preterm infants, which identifies any anomalies in the white matter. In turn, encephalopathy of prematurity is a much more comprehensive term because it seems that both primary destructive disorders and those related to brain development are influential in its origin. Its physiopathology has been explained by two theoretical models: the infective-inflammatory one and the hemodynamic one. Neuroimaginological and neurodevelopmental evaluations are necessary for the diagnosis, where the presence of cerebral palsy and of intellectual development disorders, either isolated or combined, is detected. It is much likely that encephalopathy of prematurity tends to increasingly consolidate as an independent nosological entity, taking into account its medical and social implications.

Quantitative EEG evaluation in patients with acute encephalopathy / Analise quantitativa do EEG em pacientes com encefalopatias agudas

Objective To investigate the use of quantitative EEG (qEEG) in patients with acute encephalopathies (AEs) and EEG background abnormalities. Method Patients were divided into favorable outcome (group A, 43 patients) and an unfavorable outcome (group B, 5 patients). EEGLAB software was used for the qEEG analysis. A graphic of the spectral power from all channels was generated for each participant. Statistical comparisons between the groups were performed. Results In group A, spectral analysis revealed spectral peaks (theta and alpha frequency bands) in 84% (38/45) of the patients. In group B, a spectral peak in the delta frequency range was detected in one patient. The remainder of the patients in both groups did not present spectral peaks. Statistical analysis showed lower frequencies recorded from the posterior electrodes in group B patients. Conclusion qEEG may be useful in the evaluations of patients with AEs by assisting with the prognostic determination. .

Objetivos Investigar o uso do EEG quantitativo (qEEG) em pacientes com encefalopatias agudas (EAs ) e anormalidades da atividade de base no EEG. Método s pacientes foram divididos em prognóstico favorável (grupo A, 43 pacientes) e desfavorável (grupo B, 5 pacientes). O programa EEGLAB foi utilizado para a análise do qEEG. Um gráfico da potência espectral de todos os canais foi gerado para cada participante. Os dois grupos foram comparados estatisticamente. Resultados No grupo A, a análise espectral revelou picos (frequências teta e alfa) em 84% (38/45) dos pacientes. No grupo B, um pico espectral na frequência delta foi detectado em um paciente. Os pacientes remanescentes dos dois grupos não apresentaram picos espectrais. A análise estatística mostrou menores frequências registradas nos eletrodos posteriores dos pacientes do grupo B. Conclusão O qEEG pode ser útil na avaliação de pacientes com EAs auxiliando na determinação do prognóstico. .