Combined phagocytosis-nitroblue tetrazolium reduction test in bovine neutrophils

An assay was developed for the simultaneous evaluation of phagocytosis and oxidative metabolism of bovine blood neutrophils. Phagocytosis was evaluated by using opsonized zymosan, and oxidative metabolism was evaluated by nitroblue tetrazolium (NBT) reduction. Normal bovine neutrophils exhibited moderate variation in ability to phagocytize zymosan, but little variation in ability to reduce NBT. The subcellular location of NBT reduction to formazan was determined by electron microscopy. Electron dense formazan precipitate was observed along the inner membrane of phagosomes enclosing zymosan particles and radiating from the membrane toward the center of the phagosome.     

Lymph node aspirate from a California wine-country dog

A 4-year-old, male Golden Retriever was presented to the Veterinary Medical Teaching Hospital at the University of California-Davis with a history of lethargy, inappetance, and vomiting. The patient had generalized lymphadenomegaly, marked thrombocytopenia, mild anemia, and moderate hypoalbuminemia. Moderate to marked histiocytic inflammation and lymphocytic-plasmacytic reactivity of the mesenteric, left popliteal, and right mandibular lymph nodes were diagnosed cytologically. Many macrophages contained granular to amorphous material of a uniform blue color, occasionally in morula formation, suggestive of rickettsial organisms. Exposure to raw trout was subsequently documented, leading to a presumptive diagnosis of salmon poisoning disease (SPD). The patient responded quickly to doxycycline therapy for the causative agent of SPD (Neorickettsia helminthoeca). SPD should be considered as a differential diagnosis for a canine patient with clinical signs of vomiting, diarrhea, lethargy, and lymphadenomegaly; laboratory findings of thrombocytopenia and hypoalbuminemia; and potential exposure to raw fish from an endemic area. The cytologic finding of rickettsial inclusions within lymph node macrophages is reportedly seen within a majority of SPD cases and can be valuable in supporting a clinical suspicion of SPD, as it was in this case.     

Hematologic and bone marrow changes after short- and long-term administration of two recombinant bovine granulocyte colony-stimulating factors.

Colony-stimulating factors are a category of glycoproteins that are instrumental in the regulation of hematopoiesis and inflammation. This investigation documented the clinical bone marrow and peripheral blood responses to short-term and long-term administration of a recombinant bovine granulocyte colony-stimulating factor (rb-GCSF) and an analog, where the cysteine at position 17 was substituted with a serine (rb-GCSF ser17). The colony-stimulating factors produced the expected changes in the hematologic findings of the bovine subjects in the study, and there was a cell-specific response to the compounds. The sustained neutrophilia in the long-term study indicates that the bovine species can tolerate the administration of recombinant forms of bovine GCSF for extended periods of time without detectable adverse side effects. The neutrophils from the short-term study revealed no apparent fluctuation, either as enhanced or reduced capability to reduce nitro blue tetrazolium as compared to pretreatment neutrophils. The administration of both recombinant forms of GCSF produced large increases in the bone marrow myeloid:erythroid (M:E) ratio concomitantly with the neutrophilias. This is the first preliminary report documenting the bone marrow response of cattle to the native and recombinant (rb-GCSF ser17) forms of bovine GCSF.     

Platinum-group element abundance patterns in different mantle environments

Mantle-derived xenoliths from the Cameroon Line and northern Tanzania display differences in their platinum-group element (PGE) abundance patterns. The Cameroon Line lherzolites have uniform PGE patterns indicating a homogeneous upper mantle over several hundreds of kilometers, with approximately chondritic PGE ratios. The PGE patterns of the Tanzanian peridotites are similar to the PGE systematics of ultramafic rocks from ophiolites. The differences can be explained if the northern Tanzanian lithosphere developed in a fluid-rich suprasubduction zone environment, whereas the Cameroon Line lithosphere only experienced melt extraction from anhydrous peridotites.     

Heterogeneity in phagocytic and nitroblue tetrazolium reductive properties of neutrophils from cows.

Phagocytic and nitroblue tetrazolium (NBT) reductive activities of blood neutrophils from 19 Holstein heifers were measured by light microscopic and spectrophotometric methods, respectively. These functional properties of neutrophils correlated well (r = 0.64) and varied significantly (P less than 0.05) among animals studied. Variations in phagocytosis and NBT reductive activities attributable to the source of sera were determined in experiments in which cells from the same cows and zymogen particles opsonized with heat-inactivated autologous or homologous sera were used. Variations attributable to the source of cells were determined in experiments in which cells from different cows and particles opsonized with pooled sera from all the cows were used. Most of the variation in phagocytic properties and NBT reductive activities was attributable to the source of cells (ie, each cow). The source of sera contributed slightly to the variation in NBT reductive activities, but not to the phagocytic properties. These results support the concept of functional heterogeneity of neutrophils among cows.     

Acute myelomonocytic leukemia in a horse

A 7-year-old Quarter Horse stallion with a myeloproliferative disorder was examined because of colic, and an enterolith was removed surgically. The horse experienced secondary complications after abdominal surgery, and leukopenia and thrombocytopenia were detected. Five months later, the horse was examined for recurrent peripheral edema and for repair of an abdominal incisional hernia. Acute myelomonocytic leukemia was diagnosed, and treatment with low-dose (noncytocidal) cytosine arabinoside was unsuccessful. Necropsy revealed neoplastic infiltrate in the spleen, liver, lung, adrenal gland, testes, and eye. The persistent hematologic abnormalities before the onset of overt leukemia may represent hematopoietic dysplasia or preleukemia.     

Idiopathic localized eosinophilic synovitis in a cat

Abstract: A 4-year-old male castrated Seal Point Himalayan cat was presented for evaluation of right thoracic limb lameness of 6 weeks duration. Synovial fluid analysis of the swollen right carpal joint revealed a mixed cell synovitis, with a total nucleated cell count of 13,200/μL and 34% eosinophils. A diagnosis of idiopathic localized eosinophilic arthritis was made. Additional clinical and diagnostic findings included mild lym-phadenopathy with lymphoid hyperplasia and an antinuclear antibody titer of 1:320. Lack of multisystem involvement made systemic lupus erythematosis unlikely. Immunosuppressive therapy with oral prednisone alleviated the lameness. Eosinophilic synovitis has not previously been reported in cats. An immune-mediated mechanism was likely in this case; however, the exact etiology remains unknown.