Analysis of erythropoietin and erythropoietin receptor genes expression in cattle during acute infection with Trypanosoma congolense.

Acute Trypanosoma congolense infection induced moderate, transient anemia in N'Dama cattle (trypanotolerant) and severe anemia in Boran cattle (trypanosusceptible). Erythropoietin receptor (EpoR) was cloned and sequenced from the two breeds of cattle. A single position mutation of Tyr in the Boran to His in the N'Dama predicted amino acid sequence was revealed. The mRNA transcription of erythropoietin (Epo) in kidneys and EpoR in the bone marrow of infected cattle was determined by competitive reverse transcription and the polymerase chain reaction (RT-PCR). Though Epo mRNA transcription increased in the kidneys during infection, the increase was not significantly different (p>0.05) between the two breeds of infected cattle. The level of EpoR transcripts in the bone marrow of infected N'Damas was significantly higher (p<0.05) than that detected in the marrows from infected Boran cattle. While infection seem to increase levels of transcription of IL-1alpha and beta, and TNFalpha in kidneys from both Boran and N'Dama cattle, no significant difference was detected in the level of mRNAs of these cytokines in the kidney from the two breed of cattle. The amount of IFNgamma mRNA transcripts were not changed with infection in N'Dama cattle, while on the contrary a significant higher levels of IFNgamma was found in kidneys from infected Boran cattle as compared to the other groups. A significant (p<0.05) increase in the levels of IL-1alpha and beta, and IFNgamma mRNA transcripts were detected in the marrows of infected Borans as compared to the infected N'Dama cattle. In this study the increase in the level of TNFalpha mRNA in the marrows of the two infected breeds was not different. This implies there is no negative effect of TNFalpha on hematopoiesis during acute infection. These findings suggest that the levels of Epo and EpoR in the infected Boran cattle were inadequate for their degree of anemia, which might be due in part to high expression of IFNgamma during acute infection with T. congolense.

Periodontal healing of canine experimental grade-III furcation defects treated with autologous fibrinogen and absorbable barrier membrane.

OBJECTIVE: To determine the effects of autologous fibrinogen (AF) and absorbable barrier membrane (ABM) on periodontal healing of canine experimental grade-III furcation defects. ANIMALS: 18 conditioned, laboratory-source, adult Beagles. PROCEDURE: Defects were developed bilaterally at the second and fourth premolars and maintained for 12 weeks. Defects were treated with AF, ABM, AF and ABM, or debridement. Digital subtraction radiography, histologic evaluation, and histomorphometric analysis of defect healing was done at 1, 3, and 6 months after treatment to determine percentage increases in bone volume, height, area, and length of periodontal regeneration along the perimeter of the defect. RESULTS: Comparison of defects at post-treatment intervals indicated significantly greater healing of debridement and AF-treated defects, compared with ABM-treated defects at 3 months; however, by 6 months, there were no significant differences in defect healing for all histomorphometric variables. Defects treated with ABM were associated with significantly less root ankylosis than other treatments. Defects treated with debridement had significantly greater increases in bone volume at 6 months after treatment, compared with groups treated with ABM. There was a significant correlation between regenerated bone area, bone volume, and periodontal regeneration for all treatments at 3 and 6 months after treatment. CONCLUSION AND CLINICAL RELEVANCE: Use of AF and ABM did not enhance the amount of periodontal healing, compared with debridement only. The ABM-treated defects were essentially devoid of root ankylosis. Grade-III furcation defects may respond equally well to conservative periodontal surgery or guided tissue regenerative techniques. The prevention of root ankylosis is a substantial benefit favoring this latter method of treatment.

Signs of sympathetic denervation associated with a thoracic melanoma in a horse.

Sympathetic denervation in a 20-year-old, gray, Thoroughbred-Percheron gelding was manifested by cutaneous hyperthermia and sweating over the right side of the body, demarcated by a line from the withers to the elbow and extending cranially. There was cutaneous hyperthermia over the right side of the head, but other signs of Horner's syndrome (sweating, ptosis, miosis, enophthalmos) were not present. The pattern of cutaneous hyperthermia and sweating was consistent with sympathetic denervation localized to the cervicothoracic ganglion, and thoracic radiographs revealed increased density in the craniodorsal thorax. Cytologic evaluation of a sample of pleural effusion revealed mesothelial cells containing melanin and cells suggestive of melanocytes or melanoblasts. Treatment with oral cimetidine and intrapleural cisplatin was not successful. A necropsy was not performed, but the clinical findings supported a diagnosis of thoracic melanoma involving the cervicothoracic ganglion.

Vitamin K deficiency in cats fed commercial fish-based diets.

Clinical signs of vitamin K deficiency have been observed in cats offered two commercial canned diets high in salmon or tuna. Some of the queens and kittens offered these diets had died while survivors had increased coagulation times. Necropsies revealed hepatic and, or, gastrointestinal haemorrhages. Coagulation times of survivors returned to normal after vitamin K therapy. The purpose of this study was to induce a vitamin K deficiency in kittens and determine the dietary requirement. Kittens were offered vitamin K-deficient purified diets containing antibiotics and, or, substances inherent in canned fish diets that may have contributed to the deficiency. Clinical signs of vitamin K deficiency were not observed, even though one purified diet contained only 4 micrograms K1/kg diet compared with 60 micrograms in the commercial tuna diet. Therefore, a minimum vitamin K requirement could not be determined using purified diets; nevertheless, canned commercial diets formulated primarily with fish should contain more than 60 micrograms K1/kg diet.

Cloning of a cDNA encoding bovine erythropoietin and analysis of its transcription in selected tissues.

A bovine cDNA encoding erythropoietin (Epo) was isolated by polymerase chain reaction (PCR) amplification and screening of a bovine kidney cDNA library. The sequenced cDNA has a length of 1312 bp and an open reading frame that encodes a predicted 192-amino-acid (aa) protein, including a putative signal sequence of 25 aa. A mature protein of 167 aa (18.4 kDa) results upon cleavage of the putative signal peptide. The deduced bovine mature Epo peptide exhibits 96, 88, 83, 82 and 79% sequence identity to that of sheep, swine, human, monkey and rat, respectively. The expression of the bovine Epo gene in tissues from a severely anemic calf, bovine fetus and a healthy steer was analysed by a competitive RT-PCR method. In kidneys of the severely anemic calf, Epo mRNA levels increased 60-fold relative to that from the kidneys of the healthy steer. Epo mRNA levels were threefold higher in the liver of the bovine fetus than that in its kidneys. Low levels of Epo transcripts were detected in RNA from spleen of the severely anemic calf and the bovine fetus. No Epo transcripts were detectable in spleen from the healthy steer.

Modern veterinary blood banking practices and their applications in companion animal practice.

There are two main reasons for blood component therapy: the need for an increase in oxygen-carrying capacity and improved hemostasis. Additionally, blood component therapy is used to increase plasma protein concentrations. Component therapy entails separating whole blood into its cellular and plasma components and administering the appropriate blood component based on the patient's needs. General considerations such as compatibility, defined expectations of benefits, and topics including specific disease screening, preparation of blood components, preparation of blood products for administration, and typing and crossmatching in relation to blood component therapy and its application in companion animal practice are discussed.

General principles of small animal blood component administration.

Administration of blood components instead of whole blood has become the most important means of transfusion support in dogs and in some settings in cats as well. Component administration entails the transfer of biological material and carries an inherent risk of disease transmission and adverse reactions. This article reviews the indications, pretransfusion considerations, and follow up in small animal patients receiving blood component therapy.

Use of blood and blood components in canine and feline patients with hemostatic disorders.

Therapy with blood and blood products related to hemostatic disorders in small animal practice is reviewed. Administration of platelet rich plasma and platelet concentrates in thrombocytopenia or thrombopathia is discussed. Vascular purpuras, vasculitis, and vascular inherited defects are also considered. Inherited coagulation disorders are summarized and the therapeutic choices in treating these disorders are also proposed. In addition, acquired coagulation disorders are briefly reviewed.

Intravascular leukostasis and systemic aspergillosis in a horse with subleukemic acute myelomonocytic leukemia.

Leukemia is a neoplastic disease of one or more of the cell types of the hemopoietic system and is rarely diagnosed in the horse. This report describes a case of subleukemic acute myelomonocytic leukemia in an 11-year-old gelding. Preliminary cytological diagnosis was supported by two types of laboratory investigations. Cytochemical characterization of blood and bone marrow neoplastic cells was consistent with a myelomonocytic origin. Neoplastic blast cells in peripheral blood were labeled by monoclonal antibodies specific for cell surface molecules of horse granulocytes, but they were not labeled by antibodies to T- or B-lymphocytes or macrophages. Treatment was attempted but was unsuccessful. At necropsy, intravascular leukostasis was present in all tissues examined. Fungal hyphae were also found in lung interstitium and colonic submucosa, suggesting the presence of a systemic mycosis. Nucleated cells were isolated from peripheral blood and cultured in vitro; they survived for up to 2 weeks and had evidence of cell division that was not sustained. Frozen-thawed cells stored in liquid nitrogen were also successfully cultured in vitro, but no permanent cell lines could be established.

Hemostatic defects associated with two infusion rates of dextran 70 in dogs.

We investigated changes in hemostatic function after infusion of 6% dextran 70 (high molecular weight dextran) at 2 rates. Six healthy dogs underwent 3 regimens: 20 ml of dextran/kg of body weight administered in 1 hour (trial A), 20 ml of dextran/kg administered in 30 minutes (trial B), and 0.9% sodium chloride solution as a control administered over 1 hour to achieve hemodilution equivalent to that for 20 ml of dextran/kg (trial C). Before and at 2, 4, 8, and 24 hours after the start of trials A and B, we measured PCV, total solids (TS) concentration, amount of von Willebrand factor antigen (vWf:Ag), factor VIII coagulant activity (VIII:C), prothrombin time, activated partial thromboplastin time (APTT), platelet retention in a glass bead column, and buccal mucosa bleeding time (BMBT). Values were not obtained at 8 and 24 hours for trial C. Saline-induced changes in hemostasis were significant (P less than 0.05) from baseline throughout the sample collection period. Significant differences (P less than 0.05) between trial A and control were observed for vWf:Ag, VIII:C, BMBT, APTT, TS, and PCV values at 2 hours, and for VIII:C at 4 hours. Significant differences (P less than 0.05) between trial B and control were observed for APTT, TS, and PCV values at 2 hours, and for vWf:Ag, VIII:C, BMBT, APTT, TS, and PCV values at 4 hours. During trials A and B, mean values of analytes infrequently deviated from reference intervals, and clinical signs of bleeding were not observed in any dog.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the haemostatic profile in the pre- and post parturient mare, with particular focus on the perinatal period.

Various haemostatic analytes were systematically evaluated for four months pre-partum and five months post partum in 14 healthy mares. The plasma fibrinogen concentration and both Factor VIII:C and von Willebrand factor activity showed gradual increases from mid-gestation and reached maximal, or near maximal activity at parturition. These increases were paralleled by an increase in plasma fibronectin concentration, the appearance of fibrinogen degradation products, and a modest rise in antithrombin III concentration. In contrast, the activity of Factor VII and Factor IX, and the one-stage prothrombin (PT) time and the activated partial thromboplastin (APTT) time remained relatively constant throughout the pre- and post parturient period.

An evaluation of the effect of reagent modification on routine laboratory coagulation tests.

The purpose of this study was to evaluate the effect of modifying commercial reagents for the laboratory evaluation of several haemostatic parameters in normal, non-pregnant mares. The routine coagulation screening assays, namely, the activated partial thromboplastin time (APTT) and the one-stage prothrombin time (PT), and the specific coagulation assays for the determination of the biological activity of Factors VII, VIII:C and IX, are discussed.

Cytologic, microbiologic, and biochemical analysis of bronchoalveolar lavage fluid obtained from 24 healthy cats.

Twenty-four healthy cats underwent bronchoscopy and bronchoalveolar lavage to determine the normal cytologic environment of the lower respiratory tract of cats. Initial screening to ensure the health of the study population included complete histories, physical examinations, thoracic radiography, CBC, serologic tests for feline leukemia virus, feline immunodeficiency virus, and occult heartworm, and sugar and Baermann fecal flotation. In 18 cats, protected catheter brush samples of airway secretions from the lavaged lung segment were taken for culture of aerobic and anaerobic bacteria and mycoplasma. Bronchial lavage fluid (5 sequential 10-ml aliquots of normal saline solution) was pooled and filtered with cotton gauze. The unspun sample was used for determination of a total nucleated cell count. Lavage fluid was cytocentrifuged and 500 cells/slide were scored for determination of the cellular differential. Activity of lactate dehydrogenase and concentrations of total protein and IgG within the supernatant were measured, and assays were performed to detect the presence of IgA and IgM. Complete histologic evaluation of the lavaged lung of each of 6 random-source cats was performed after differential cell counting revealed 18% eosinophils within bronchoalveolar lavage fluid recovered from this group. Alveolar macrophages were the predominant cells encountered; however, a quarter of all cells recovered were eosinophils. A significant relationship was not found between the abundance of eosinophils in the lavage fluid, and either isolation of aerobic bacteria, high total nucleated cell counts, total protein concentrations, or activity of lactate dehydrogenase. Histologic evaluation of the lungs of 5 of 6 random-source cats revealed normal lungs in 2 cats, and minimal abnormal change in 3 others. Evaluation of the lungs from 1 random source cat revealed acute, mild eosinophilic bronchiolitis. We conclude that large numbers of eosinophils may be retrieved from the bronchoalveolar lavage fluid of healthy cats.

Evaluation of hemostatic defects secondary to vascular tumors in dogs: 11 cases (1983-1988).

Two populations of dogs with cutaneous hemangiomas and hemangiosarcomas were evaluated retrospectively. One population consisted of 96 dogs seen at the Veterinary Medical Teaching Hospital at the University of California, Davis. The second population consisted of 116 dogs that had skin biopsy specimens submitted to a private veterinary diagnostic laboratory for histologic diagnosis. Nine dogs from the teaching hospital and 2 dogs, from which samples had been submitted to the veterinary diagnostic laboratory, developed hemostatic defects in association with the tumors. Hemostatic defects included hemorrhage directly from the tumor, thrombocytopenia, hypofibrinogenemia, and findings associated with disseminated intravascular coagulation. Because bleeding during surgery can develop in animals with hemostatic defects, dogs with one or more tumors suspected of being vascular in origin should have platelet numbers and hemostatic analytes evaluated prior to surgery, especially if petechiae or ecchymoses are evident.

Thrombocytosis associated with a myeloproliferative disorder in a dog.

A dog with a myeloproliferative disorder and thrombocytosis had clinical signs that were consistent with a diagnosis of essential thrombocythemia. The dog was treated with aspirin, radioactive phosphorus, and melphalan. Eighteen months after referral, the disorder progressed to chronic granulocytic leukemia, and treatment was switched to hydroxyurea. Fourteen months later, the dog was euthanatized because of uncontrollable atrial fibrillation.

Hemolysis as a factor in clinical chemistry and hematology of the dog.

Serum biochemical, hemostatic, and hematologic analytes were determined by four laboratories on dog serum or plasmas containing increasing amounts of hemolysate. From the results of testing, interferographs were prepared to aid in decision making and to enhance visualization of the effects of hemolysis on the determination of the analytes. Heniktsus consistently interfered with the analysis of creatinine phosphokinase, lactic dehydrogenase, aspartate aminotransferase, lipase, and albumin, all of which appeared to increase with increasing hemolysis. The results for the remainder of the biochemical, hemostatic, and hematologic analytes varied greatly among analyzers or methods, rarely in a predictable manner, indicating that each laboratory should evaluate the effects of hemolysis on each analyzer and for each method used, in order to make informed decisions on the use of hemolyzed but irreplaceable samples.