Chicken anemia agent: an electron microscopic study

Particles of chicken anemia agent (CAA) negatively stained with uranyl acetate were found to be 26.5 nm in diameter. The surface detail evident on the particles indicated that the virus capsid was composed of 32 structural subunits arranged as in a class P = 3 icosahedron with a triangulation number of 3. Using mouse monoclonal antibodies to CAA and a gold-labeled goat anti-mouse IgG, CAA-specific structures were observed by thin-section electron microscopy in infected MDCC-MSB1 cells and in thymic lymphocytes from experimentally infected chicks. These consisted of electron-dense, granular, non-membrane-bound nuclear inclusions, which were often ring-shaped, and cytoplasmic accumulations of microtubules. Aggregates of virus-like particles were sometimes observed in the nuclei of infected MDCC-MSB1 cells. The nucleolar involvement that is characteristic of the morphogenesis of parvoviruses was not observed with CAA.     

Successful treatment of suspected essential thrombo-cythaemia in the dog

Essential thrombocythaemia in an eight-year-old Irish setter is described. The condition is characterised by an autonomous overproduction of thrombocytes in the absence of overt leukaemia. This is believed to be the first recorded case of this condition in the dog. The paper describes the diagnosis and treatment by combination chemotherapy using vincristine, cytosine arabinoside, cyclophosphamide and prednisolone.     

Ultrasonographic appearance of torsion of a testicular seminoma in a cryptorchid dog

An intra-abdominal testicular tumour was diagnosed in a 10-year-old, male, cryptorchid golden retriever. Upon surgical removal, torsion of the testis was found. The histopathological diagnosis was seminoma. The ultrasound examination in this case revealed a parenchymal mass lesion. An ultrasound examination is a useful supplemental diagnostic tool for differentiation of abdominal mass lesions.     

Long-term anaesthesia with propofol and alfentanil in the dog and its partial reversal with nalbuphine

Prolonged surgical anaesthesia in the dog was induced with propofol (6.5 ± 1.3 mg/kg) followed by alfentanil (25.5 ± 5 μg/kg) (mean ± 1 sd) and maintained with a continuous infusion of propofol (0.14 to 0.18 mg/kg/min) and alfentanil (2 to 3 μg/kg/min). Neuromuscular blockade was produced with vecuronium (0.1 mg/kg). After induction of anaesthesia with propofol, administration of alfentanil to dogs which had received no pre-anaesthetic medication produced cardiac arrest and apnoea. Administration of atropine intravenously immediately prior to alfentanil prevented these cardiac depressant effects. The cardiac depressant effect of alfentanil was not as severe in a second group of dogs in which anaesthesia was induced with thiopentone. After commencing the continuous infusion anaesthetic regime and establishment of IPPV, blood pressure and heart rate remained stable during the remaining 4 to 6 h period of anaesthesia. Recovery from anaesthesia was smooth and uneventful. The depressant effects of alfentanil on respiration and on consciousness were reversed rapidly by administration of nalbuphine (10 mg total dose). The smooth recovery and the integration of anaesthesia and post operative analgesia attained by the reversal of alfentanil with nalbuphine make this an attractive anaesthetic regime for major surgery in dogs, provided that facilities for IPPV are available.     

The Neocortex of the Dog

This article describes the structural organization of the neocortex of the dog from purely morphological point of view. Series of 50 urn transverse sections were cut from the frozen right hemiencephala of adult greyhounds, stained by N issl's method, and drawn. His's method was then used to construct life-size lateral, dorsal and medial views of the hemiencephalon from 38 sections located at regular intervals. Once the cytoarchitectonic criteria to be used had been established on the basis of preliminary observations, all the sections of each hemiencephalon were examined microscopically and the cytoarchitectonic types observed in each mapped on the corresponding drawing. These maps were then projected onto lateral, dorsal and medial views of the whole hemiencephalon to produce a classical cytoarchitectonic map of the neocortex made up of 21 types, 7 of them agranular (with no inner granular layer), 2 dysgranular (with a granular layer with diffuse boundans) and the rest granular (with a well-defined layer IV). Various areas of cortex whose characteristics were intermediate between those of adjoinin areas were classified in a residual typus intermedius.