Evaluation of monoclonal antibodies for identification of subpopulations of myeloid cells in bone marrow obtained from dogs

OBJECTIVE: To evaluate monoclonal antibodies that may be useful for immunophenotyping myeloid cells in bone marrow of dogs. SAMPLE POPULATION: Bone marrow specimens obtained from 5 dogs. DESIGN: Specimens were labeled with monoclonal antibodies that detected CD18, major histocompatability antigen class-II (MHC class-II), CD14, and Thy-1. Cells labeled with each of the antibodies were isolated by use of a fluorescence-activated cell sorter. Differential cell counts of sorted cells were used to determine cells that were labeled by each of the various antibodies. RESULTS: Myeloid cells labeled with anti-CD18 antibody included granulocytes, lymphocytes, and monocytes-macrophages. Immature and mature granulocytes were labeled. Lymphocytes, monocytes-macrophages, and eosinophils were labeled with anti-Thy-1 antibody. Cells labeled with anti-MHC-class II antibody included approximately 9% of bone marrow cells, which consisted almost exclusively of lymphocytes and monocytes-macrophages. Approximately 4% of bone marrow cells were labeled with anti-CD14 antibody, with > 90% of sorted cells being monocytes-macrophages. CONCLUSIONS AND CLINICAL RELEVANCE: Four monoclonal antibodies for use in detecting subpopulations of canine bone marrow cells were evaluated. These antibodies should be useful in differentiating the origin of leukemic cells in dogs.     

Prevalence of the Salmonella plasmid virulence gene "spvD" in Salmonella strains from animals]

Strains of Salmonella isolated from animals in Germany (n = 878) were analysed for the presence of the spvD gene ("Salmonella plasmid virulence gene D") by DNA-DNA hybridization. The spvD gene was only detected in strains of serovars Typhimurium (93.3%), Enteritidis (97.1%), and Dublin (100%) as well as in two rough strains of Salmonella enterica. Salmonella isolates from mammals carried the gene more frequently (cattle 94.0%, horses 92.6%, pigs 73.7%) than those from birds (33.3%) or reptiles (4.5%). Due to its high prevalence in epidemiologically relevant salmonellae, the virulence factor spvD may represent a sensitive and specific target in various serovars for diagnostic or immunization strategies.     

Myelodysplastic syndrome with sideroblastic differentiation in a dog

A dog with myelodysplastic syndrome had microcytic hypochromic anemia, with siderocytes, poikilocytosis, hypersegmented neutrophils and giant platelets in peripheral blood. In bone marrow, the erythroid series showed immaturity, asynchronous maturation and sideroblasts. Dysgranulopoiesis and dysthrombopoiesis also were present, and hemosiderin was increased. Serum iron concentration was high, and both iron deficiency and lead toxicity were excluded as the cause of dyscrasia. This case represents a unique variant of myelodysplastic syndrome, best described as sideroblastic myelodysplasia. We propose the terms dyserythropoiesis, sideroblastic dyserythropoiesis, dyserythropoiesis with excess blasts, myelodysplasia and sideroblastic myelodysplasia to describe and categorize myelodysplastic syndromes in dogs.     

Clinical features of inflammatory liver disease in cats: 41 cases (1983-1993)

OBJECTIVE: To compare the clinical and clinicopathologic findings in and prognosis for cats with lymphocytic portal hepatitis (LPH) versus cats with acute or chronic cholangiohepatitis (CH). DESIGN: Retrospective study. ANIMALS: 25 cats with LPH; 16 cats with CH (7 acute, 9 chronic). PROCEDURE: Cats with LPH and CH were selected by evaluating records from liver biopsy specimens submitted to the University of Minnesota Veterinary Teaching Hospital during a 10-year period. Clinical and clinicopathologic data were retrieved. RESULTS: Cats with CH had higher segmented and band neutrophil counts, alanine aminotransferase activities, and total bilirubin concentrations than did cats with LPH. Cats with acute CH had higher segmented and band neutrophil counts and lower serum alkaline phosphatase activities and total bilirubin concentrations than did cats with chronic CH. Twelve of 14 cats with LPH or CH had coarse or nodular texture to the liver on ultrasonography, with loss of portal vein wall clarity noticed in 4 of 8 cats with LPH. Sixteen of 23 cats with LPH and 8 of 15 cats with CH survived > 1 year. Of those cats living < 1 year, all cats with LPH and 5 of 7 cats with CH had a serious concurrent illness that may have been responsible for their deaths. CLINICAL IMPLICATIONS: LPH and CH can be detected and tentatively differentiated through evaluation of clinical laboratory test results, but histologic evaluation of liver specimens is necessary for definitive differentiation. Survival time was good regardless of the type of inflammatory liver disease.     

Evaluation of lipopolysaccharide-induced activation of equine neutrophils

OBJECTIVE: To evaluate lipopolysaccharide (LPS)-induced activation of equine neutrophils in blood. SAMPLE POPULATION: Blood samples from 5 healthy adult Thoroughbreds. PROCEDURES: Neutrophil integrin (CD11/CD18) expression, size variation, degranulation, and deformability were measured with and without incubation with LPS. Time and concentration studies were done. The mechanism of endotoxin-induced neutrophil activation was investigated by inactivating complement or preincubating neutrophils with inhibitors of tumor necrosis factor-alpha (TNF-alpha) synthesis, prostaglandin-leukotriene synthesis, or platelet-activating factor. RESULTS: Incubation of equine neutrophils with LPS increased cell surface expression of CD11/CD18, decreased neutrophil deformability, increased and decreased neutrophil size, and induced neutrophil degranulation. The LPS-induced neutrophil activation was attenuated by addition of inhibitors of TNF-alpha and prostaglandin-leukotriene synthesis. CONCLUSIONS AND CLINICAL RELEVANCE: Equine neutrophils are readily activated in vitro by LPS, resulting in increased expression of integrin adhesion molecules, decreased deformability, variation in neutrophil size, and degranulation. The tests used to detect activated neutrophils in this study may be useful in detecting in vivo neutrophil activation in horses with sepsis and endotoxemia.     

Pyogranulomatous myocarditis due to Staphylococcus aureus septicaemia in two harbour porpoises (Phocoena phocoena)

Staphylococcus aureus septicaemia was diagnosed in a dead, stranded harbour porpoise from the German Baltic Sea and in a live harbour porpoise by-caught in inner Danish waters and taken into captivity. Lesions included pyogranulomatous myocarditis, necrotising suppurative bronchopneumonia, pyelonephritis, osteomyelitis and leptomeningitis, and abscesses in lymph nodes and skeletal muscles. The captive animal had fibrinous suppurative epicarditis and pyogranulomatous myocarditis with abscesses. In both animals the organism was suspected to have entered through skin lesions or via the respiratory tract.     

Role of inflammatory mediators in priming, activation, and deformability of bovine neutrophils

OBJECTIVE: To determine the capacity of inflammatory mediators tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), platelet-activating factor (PAF), lipopolysaccharide (LPS), and leukotoxin to prime, activate, or alter deformability of adult bovine neutrophils. SAMPLE POPULATION: Blood collected from 5 healthy adult Holstein cows. PROCEDURE: Isolated neutrophils or whole blood was incubated with TNF-alpha, IL-8, PAF, LPS, or leukotoxin, and neutrophil chemiluminescence, degranulation, deformability, shape change, CD11b expression, and size distribution was measured. RESULTS: Incubation with TNF-alpha, IL-8, PAF, and LPS primed neutrophils for oxygen radical release but caused minimal oxygen radical release by themselves. None of the inflammatory mediators induced degranulation. Incubation with TNF-alpha and PAF resulted in a decrease in neutrophil deformability and induced shape change in neutrophils. Incubation with PAF consistently resulted in an increase in neutrophil size as measured by use of flow cytometry. Only IL-8 caused an increase in expression of CD11b by neutrophils. CONCLUSIONS AND CLINICAL RELEVANCE: Inflammatory mediators tested had minimal effects on neutrophil oxygen radical production or degranulation but did prime neutrophils for oxygen radical production. Incubation with PAF and TNF-alpha caused a decrease in neutrophil deformability and altered neutrophil shape and size. Results of our study indicate that PAF- and TNF-alpha-induced changes in neutrophil deformability and size may cause integrin- and selectin-independent trapping of neutrophils in the lungs of cattle with pneumonic pasteurellosis.