Equine Protozoal Myeloencephalitis: An Updated Consensus Statement with a Focus on Parasite Biology, Diagnosis, Treatment, and Prevention

Equine protozoal myeloencephalitis (EPM) remains an important neurologic disease of horses. There are no pathognomonic clinical signs for the disease. Affected horses can have focal or multifocal central nervous system (CNS) disease. EPM can be difficult to diagnose antemortem. It is caused by either of 2 parasites, Sarcocystis neurona and Neospora hughesi, with much less known about N. hughesi. Although risk factors such as transport stress and breed and age correlations have been identified, biologic factors such as genetic predispositions of individual animals, and parasite-specific factors such as strain differences in virulence, remain largely undetermined. This consensus statement update presents current published knowledge of the parasite biology, host immune response, disease pathogenesis, epidemiology, and risk factors. Importantly, the statement provides recommendations for EPM diagnosis, treatment, and prevention

Nicotinamide Inhibits Alkylating Agent-Induced Apoptotic Neurodegeneration in the Developing Rat Brain

BACKGROUND: Exposure to the chemotherapeutic alkylating agent thiotepa during brain development leads to neurological complications arising from neurodegeneration and irreversible damage to the developing central nerve system (CNS). Administration of single dose of thiotepa in 7-d postnatal (P7) rat triggers activation of apoptotic cascade and widespread neuronal death. The present study was aimed to elucidate whether nicotinamide may prevent thiotepa-induced neurodegeneration in the developing rat brain. METHODOLOGY/PRINCIPAL FINDINGS: Neuronal cell death induced by thiotepa was associated with the induction of Bax, release of cytochrome-c from mitochondria into the cytosol, activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP-1). Post-treatment of developing rats with nicotinamide suppressed thiotepa-induced upregulation of Bax, reduced cytochrome-c release into the cytosol and reduced expression of activated caspase-3 and cleavage of PARP-1. Cresyl violet staining showed numerous dead cells in the cortex hippocampus and thalamus; post-treatment with nicotinamide reduced the number of dead cells in these brain regions. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) and immunohistochemical analysis of caspase-3 show that thiotepa-induced cell death is apoptotic and that it is inhibited by nicotinamide treatment. CONCLUSION: Nicotinamide (Nic) treatment with thiotepa significantly improved neuronal survival and alleviated neuronal cell death in the developing rat. These data demonstrate that nicotinamide shows promise as a therapeutic and neuroprotective agent for the treatment of neurodegenerative disorders in newborns and infants

Detection of Neospora sp. antibodies in cart horses from urban areas of Curitiba, Southern Brazil Detecção de anticorpos anti-Neospora sp. em cavalos de carroceiros de áreas urbanas de Curitiba, Sul do Brasil

Neospora caninum is a protozoan parasite which affects dogs as definitive hosts and several mammalian species as intermediate hosts mainly causing abortions and central nervous system disorders. The reemerging population of cart horses for carrying recycling material in urban areas of major cities in Brazil may have an impact on disease spreading, and these animals may be used as sentinels for environmental surveillance. Thus, the present study investigated the frequency of Neospora sp. antibodies in cart horses from Curitiba and surrounding areas, Paraná State, Southern Brazil. IgG antibodies against Neospora sp. were detected using indirect fluorescence antibody test (IFAT), and titers equal to or higher than 1:50 were considered reactive. Of all samples, 14/97 (14.4%) were positive: 2/29 (6.9%) were younger than 5; 5/26 (19.2%) between 6 and 9; and 6/31 (19.4%) older than 10 years of age. One of the 11 animals with unknown age was positive (9.1%). Cart horses are likely to be more exposed to dog feces and to Neospora sp. oocyst contamination in urban settings and a lower frequency of disease in dogs may have a negative impact on horse infection risk in these areas.<br>Neospora caninum é um protozoário parasita que afeta cães como hospedeiros definitivos e diversos mamíferos como hospedeiros intermediários, envolvido em abortos e distúrbios do sistema nervoso central. A população reemergente de cavalos de carroceiros utilizados para transportar material reciclável em áreas urbanas de grandes cidades brasileiras na disseminação de doenças, e estes animais podem ser utilizados como sentinelas para vigilância ambiental. Deste modo, no presente estudo foi investigada a frequência de anticorpos anti-Neospora sp. em cavalos de carroceiros da Região Metropolitana de Curitiba, Estado do Paraná, Sul do Brasil. Anticorpos da classe IgG anti-Neospora sp. foram detectados utilizando a reação de imunofluorescência indireta (RIFI), e títulos maiores ou iguais a 1:50 foram considerados reagentes. Do total de amostras testadas, 14/97 (14,4%) foram positivas: 2/29 (6,9%) tinham menos do que 5,5/26 (19,2%) entre 6 and 9, e 6/31 (19,4%) mais de 10 anos de idade. Um dos 11 animais positivos não tinha a idade conhecida (9,1%). Como cavalos de carroceiros possivelmente estejam mais expostos a oocistos de Neospora sp. em ambientes urbanos, uma baixa freqüência da doença em cães pode ter impacto negativo no risco de infecção de cavalos nestas áreas