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M K Axthelm

Publications and source records attributed to M K Axthelm.

45 records · Page 3Linked to original sources
PubMed1987

Canine distemper virus-induced thrombocytopenia.

Effects of canine distemper virus (CDV) infection on circulating platelet values were studied in gnotobiotic dogs inoculated with R252-CDV. Thrombocytopenia (less than 200,000 platelets/microliter) was present on postinoculation day (PID) 5 and persisted through PID 15. Peak thrombocytopenia occurred on PID 10 (less than 85,000 platelets/microliter). Thrombocytopenia was accompanied by lymphopenia, neutropenia, and monocytopenia. Platelet membrane-bound CDV antigen and IgG were present from PID 7 onward; neither the third component of complement nor IgM was detected on platelets from CDV-inoculated dogs. The mean number of megakaryocytes per unit of bone marrow surface area was unchanged. Megakaryocyte infection was present in dogs euthanatized on PID 4 (0.33%), increased slightly in dogs euthanatized on PID 8 (3%), and increased sharply in dogs euthanatized on PID 9 and 10 to 17.8% and 8.3%, respectively. Phagocytosis of platelets by stellate reticuloendothelial (Kupffer's) cells in the liver was prominent in dogs euthanatized from PID 5 onward. Seemingly, CDV-induced thrombocytopenia was mediated by virus-antibody immune complexes on platelet membranes. Decreased platelet production after PID 8 resulting from direct viral infection of megakaryocytes was a likely contributing factor and occurred against a background of profound virus-induced dysfunctions of all hematopoietic cellular elements.

Animals↗
PubMed1987

Canine distemper virus: in vivo virulence of in vitro-passaged persistent virus strains.

Groups of ferrets were inoculated intraperitoneally with cell lysates or equivalent doses of whole cells from 9 different cell lines persistently infected with canine distemper virus. Viral persistence in these cell lines was characterized by noncytolytic infection and restricted release of cell-free infectious virus. In vivo replication competency of the various viruses in ferrets ranged from nil to virulent and did not correlate with in vitro titers of inocula. Ferret virulence (cell lysates only) for one cell line (CCL64-RCDV) was associated with morphologic absence of virion assembly, failure to interfere with lytic virus replication after superinfection, and in vitro infectivity restricted to canine macrophage-like tumor cells. Virion protein production in the CCL64-RCDV virulent inoculum and in the CCL64-Ly avirulent inoculum was evaluated by use of the immunoblot technique. All major virion proteins were produced by infected cells. Virulence was not associated with obvious changes in electrophoretic mobility of virion proteins when profiles of ferret-virulent CCL64-RCDV were compared with those of avirulent CCL64-Ly.

Animals↗
PubMed1986

Immunocytochemical methods for demonstrating canine distemper virus antigen in aldehyde-fixed paraffin-embedded tissue.

The effects of enzymatic digestion, sodium borohydride reduction, acids used in decalcification procedures and techniques for inactivation of endogenous peroxidase were sequentially evaluated for their effect on the immunoreactivity of canine distemper virus in aldehyde-fixed paraffin-embedded tissue. Enzyme digestion improved immunoreactivity while sodium borohydride reduced background staining. Paraformaldehyde-glutaraldehyde-fixed tissues required thioglycolic acid treatment prior to enzyme digestion and sodium borohydride reduction to obtain results comparable to results obtained in formalin-fixed tissues. Detailed protocols for indirect immunofluorescence and the avidin-biotin-peroxidase complex procedure are provided.

Acids↗
PubMed1984

In vitro propagation of canine distemper virus: establishment of persistent infection in Vero cells.

Primary cultures of bovine fibroblast (BF) and canine brain cells, persistently infected with virulent R252-canine distemper virus (CDV), were cocultured with African green monkey (Vero) cells. Transfer of persistent CDV from BF to Vero cells varied inversely with the in vitro passage level (age) of the CDV-infected BF cells. Successful transfer of CDV to Vero cells was signaled by the transient appearance of viral syncytia, rapid spread of viral antigen to all Vero cells in the culture, and by recovery of cell-free Vero-infectious virus in culture fluids. With time, viral cytopathic effects in Vero cells containing CDV disappeared, and the infected lines could not be distinguished from noninfected control Vero cells, except by immunoassay for viral antigen.

Animals↗
PubMed1982

Canine parvovirus infection potentiates canine distemper encephalitis attributable to modified live-virus vaccine.

Twelve gnotobiotic dogs from 2 litters were allotted to 3 groups. Group A dogs received a modified-live polyvalent (canine distemper, adenovirus type 2, and parainfluenza virus and Leptospira -canicola-icterohemorrhagiae bacterin) vaccine 3 days prior to oral inoculation with canine parvovirus (CPV). Group B dogs received CPV alone. Group C dogs received 1 dose of vaccine only. In none of the 9 CPV-inoculated dogs did clinical signs of CPV infection develop, although high serum antibody titers for CPV developed in all of them. However, in 2 of the 5 CPV-inoculated vaccinates, canine distemper virus encephalomyelitis subsequently developed. The results suggested that CPV exerts an immunomodulating effect on canine immune responses and may be responsible for vaccination failures in dogs.

Animals↗
PubMed1981

Congenital microhydranencephalus in cattle.

Hydranencephaly with porencephalic cavitation of the cerebellum was diagnosed, over a 2-year period, in five calves from an 80-cow herd. Affected calves were blind and exhibited fine head tremors and limb rigidity. Bovine virus diarrhea-mucosal disease (BVD-MD) antigens, found in the tissues of two calves, were considered to be the likely cause.

Anencephaly↗
PubMedDate not supplied

SIV envelope glycoprotein epitopes recognized by antibodies from infected or vaccinated rhesus macaques.

We analyzed SIV-specific monkey sera to localize B-cell epitopes of the envelope glycoprotein of SIV (gp130), using overlapping synthetic peptides representing the entire SIV gp130 protein and sera from experimentally infected monkeys and monkeys immunized with whole, inactivated SIV. A B-cell epitope which induces neutralizing antibody production and T-cell responses was characterized as well as a new B-cell epitope and a previously described neutralizing epitopes. Vaccinated monkey sera recognize the three epitopes differentially relative to unimmunized controls, and a correlation appears to exist between degree of cross-neutralization by infected monkey sera and degree of binding to these three regions.

Amino Acid Sequence↗
PubMedDate not supplied

Type D SRV-2 virus-specific CD8+ and CD4- CD8- T cells that regulate virus-induced T cell proliferation in Celebes macaques.

These studies defined SRV-2 envelope peptides 96-102, 127-152, and 233-249 as T cell epitopes that induce significant T cell proliferation. Peripheral blood lymphocytes of Celebes macaques (Macaca nigra) exposed to SRV-2 and currently virus- antibody+, cultured with SRV-2 virus show strongly suppressed T cell responses and have two immunoregulatory T cell populations.

Animals↗