ABSTRACT
Six weeks after vaccination with modified live feline parvovirus vaccine, a cat gave birth to five kittens, three of which died soon afterwards. The remaining two kittens (A and B) survived, but at 8 weeks of age were unable to walk and showed abnormal behaviour, with lack of menace and oculovestibular responses, and severe dysmetria. These signs suggested multifocal disease associated with the cerebrum and cerebellum. Magnetic resonance imaging demonstrated severe bilateral (kitten A) or unilateral (kitten B) hydrocephalus or hydranencephaly, combined with cerebellar agenesis (kitten A) or severe hypoplasia (kitten B). Hydranencephaly was confirmed histopathologically in both kittens. Parvovirus was isolated from the kidney of one kitten. Parvoviral DNA was amplified by the polymerase chain reaction (PCR) from paraffin wax-embedded brain of both kittens. The severe malformations observed in these kittens presumably resulted from an in-utero parvovirus infection, possibly due to vaccination, that occurred late in the first, or early in the second, trimester of pregnancy.
Subject(s)
Cat Diseases/pathology , Cerebellum/pathology , Hydranencephaly/veterinary , Parvoviridae Infections/veterinary , Parvovirus , Animals , Brain/abnormalities , Brain/virology , Cat Diseases/virology , Cats , Cerebellum/virology , Cytopathogenic Effect, Viral , Female , Hydranencephaly/pathology , Hydranencephaly/virology , Parvoviridae Infections/complications , Parvoviridae Infections/pathology , Polymerase Chain Reaction/veterinary , Pregnancy , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/adverse effects , Viral Vaccines/administration & dosage , Viral Vaccines/adverse effectsABSTRACT
BACKGROUND: Overexpression of the MDR1 gene often contributes to antineoplastic drug resistance. The purpose of this study was to characterize the canine MDR1 mRNA homologue and evaluate its expression in both canine cell lines and lymphomas. MATERIALS AND METHODS: The abundance of the canine MDR1 transcript was assessed in three resistant cell lines and in pretreatment canine lymphoma using semi-quantitative RT/PCR. RESULTS: Canine transcript was 4.5 Kb with 93% sequence homology to human MDR1, and 90% homology to mouse and hamster equivalent genes. Increase in MDR1 transcript levels was observed in three progressively resistant canine cell lines. De novo MDR1 transcript expression was independent of response to therapy in dogs with lymphoma. CONCLUSIONS: We conclude that the canine MDR1 mRNA homologue is structurally similar to the human transcript. Expression of MDR1 mRNA correlates with in vitro drug sensitivity but does not correlate with in vivo doxorubicin sensitivity in canine lymphoma.
