Isolation of Aleutian mink disease virus by affinity chromatography

Affinity chromatography was used to isolate the Aleutian disease virus of mink. Dissociation of the immunoadsorbent-virus complex with 0.75 molar sodium chloride and then with a glycine-hydrochloride gradient released infective particles resembling picornaviruses. The elution profile suggests that two different types of virus-antibody complexes are formed, one dissociated by sodium chloride and another that requires glycine-hydrochloride in addition to sodium chloride for release of virus.

Mastocytoma and gastroduodenal ulceration. Gastric and duodenal ulcers in dogs with mastocytoma

Twenty of 24 dogs with mastocytoma had ulcers of the gastroduodenal mucosa. The ulcers were more frequent in the stomach, less frequent in the duodenum. Perforating ulcers caused death in 3 dogs. Vascular lesions were frequent in these dogs, and it was considered that the vascular alterations may have contributed to the gastroduodenal ulceration associated with mast-cell neoplasms.

'Nuclear' antigens and antinuclear antibodies in mink sera

Aleutian disease of mink is transferrable by cell-free extracts and is characterized by hepatitis, vasculitis, nephritis, and hypergammaglobulinaemia. Because of increasing evidence incriminating antigen—antibody complexes in vasculitis disorders, the presence of nuclear antigens and antinuclear antibodies in mink sera was investigated.

Serum pools as well as individual serum specimens were obtained from uninfected mink, mink with experimentally induced Aleutian disease, mink with spontaneous Aleutian Disease, all of genotype Aa as well as from `normal' mink of similar age from colonies without Aleutian disease.

The serum pool from mink before and after experimentally induced Aleutian disease appeared to contain `nuclear' antigens detectable by rabbit anti-DNA antibodies in complement fixation and precipitin tests. The protein-free extracts of these serum pools gave strong reactions for deoxypentose in the diphenylamine tests. These serum pools also were shown to contain antinuclear antibodies by the immunofluorescence tests on human leucocyte nuclei and in precipitin tests against single strand calf thymus DNA. Sera from individual mink were similarly shown to contain `nuclear' antigens and antinuclear antibodies. The incidence and quantity of antigens and antibody detected were much greater in sera from mink after experimentally induced disease than in sera taken from mink before inoculation. The presence of `nuclear' antigens and antinuclear antibodies did not correlate with the degree of hypergammaglobulinaemia. Sera from `normal' mink in colonies without overt disease had neither antigens nor antibodies detectable in precipitin tests. Sera from mink with spontaneously acquired Aleutian disease had a high incidence of `nuclear' antigens and anti-DNA antibodies detectable in precipitin tests.

The `nuclear' antigens were detectable in Ouchterlony precipitin tests by specific rabbit anti-DNA antibodies. The precipitins formed lines of partial identity with those between the rabbit anti-DNA antibodies and single strand calf thymus DNA. However, the antigens in mink sera were not destroyed by prior incubation with DNAse which had been the case with DNA antigens detected in some human and mouse sera.

The antinuclear antibodies were detected in immunofluorescence tests using specific antibodies to mink γ-globulins, were shown to fix complement with single strand calf thymus DNA, but not with DNA that had been digested with DNAse, and formed precipitins with single strand calf thymus DNA which showed complete identity with precipitins formed by rabbit anti-DNA antibodies. Evidence for the simultaneous presence of `nuclear' antigens with antinuclear antibodies in the serum from mink with Aleutian disease was frequently evident. This observation is consistent with the hypothesis for the pathogenetic role of antigen-antibody complexes.

Aleutian disease of mink has certain clinical pathological and serological similarities with disease in New Zealand Black mice and in man with systemic lupus erythematosus. Since Aleutian disease of mink and disease of New Zealand black mice may both be examples of `slow virus' infections, a similar aetiology should be considered for certain autoimmune diseases of man, e.g. systemic lupus erythematosus.

Cutaneous lymphomatosis in a boxer dog. Pathologic and biochemical observations

A 9-ycar-old boxer dog had rapidly progressive cutaneous lymphomatosis. There were pulmonary metastases, marked peripheral eosinophilia, eosinophilic infiltration of the cutaneous lesions, and a moderate heterogeneous elevation of the serum immunoglobulins, especially those with gamma mobility. The disease had similarities to viral-induced cutaneous leukosis of chickens and cattle.