Studies of the pathogenesis of anemia of inflammation: erythrocyte survival

Erythrocyte survival was investigated in healthy cats and in cats with sterile abscesses. Erythrocyte survival time in cats with sterile abscesses was found to be significantly reduced. The erythrocyte destruction appeared to be the major factor in the early stages of anemia of inflammation.     

Suppression of feline bone marrow fibroblast colony-forming units by feline leukemia virus

Bone marrow fibroblast colony-forming units (CFU-F) were evaluated in cats experimentally infected with feline leukemia virus (FeLV). Cats that developed persistent viral infection and anemia (progressor cats) had a progressive decrease in the number of CFU-F at 2, 4, 6, 8, and 10 weeks after inoculation with FeLV. This suppression of CFU-F number in progressor cats ranged from 16 to 44% of the preinoculation CFU-F value. Cats that did not develop persistent viral infection or anemia (regressor cats) had decreased numbers of CFU-F (24% of the preinoculation CFU-F value) at 2 weeks after inoculation, but normal CFU-F numbers at 4, 6, 8, and 10 weeks after inoculation. In vitro incubation of bone marrow mononuclear cells from healthy cats with the 15,000-dalton envelope protein of FeLV resulted in decreased number of CFU-F (21% of that of untreated cultures). The number of CFU-F from bone marrow mononuclear cells incubated with the 27,000-dalton core protein of FeLV was similar to that from untreated cultures.     

Serum Erythropoietin Concentrations Measured by Radioimmunoassay in Normal, Polycythemic, and Anemic Dogs and Cats

Serum erythropoietin (Epo) concentrations were measured by radioimmunoassay (RIA) in normal, polycythemic, and anemic dogs and cats. The serum Epo concentration in normal dogs ( n = 25) ranged from 7 to 37 mU/mL (median, 20 mU/mL); and in normal cats ( n = 11) ranged from 9 to 38 mU/mL (median, 18 mU/mL). Polycythemic animals (PCV < 55% in dogs, > 45% in cats) were classified as those with primary (polycythemia vera), secondary, or polycythemia of uncertain etiology. Dogs with polycythemia vera (PV, n = 8) had a median serum Epo concentration in the normal range (17 mU/mL); cats with PV ( n = 7) also had a median serum Epo concentration that was within the normal range (10 mU/mL). In the category of secondary polycythemias, dogs ( n = 7) (median, 30.7 mU/mL) and cats ( n = 2) had normal Epo concentrations. The median serum Epoconcentration was significantly decreased ( P > .05) in dogs with PV compared with dogs with secondary polycythemias. The median serum Epo concentrations in dogs ( n = 13) and cats ( n = 5) with anemias not due to chronic renal disease were significantly increased ( P > .05) compared with normal dogs and cats. In cats with anemias due to chronic renal disease ( n = 5) the median serum Epo concentration was not significantly different from normal cats. The measurement of the serum EPO concentration may be useful in assessment of anemia or polycythemia but the overlap of values with the normal range in all groups evaluated limit its diagnostic use.     

Variable suppression of feline bone marrow fibroblast colony-forming units by two isolates of feline leukemia virus.

Bone marrow fibroblast colony-forming units (CFU-F) were evaluated in cats experimentally infected with different, isolates of FeLV. Cats infected with the Kawakami-Theilen isolate of FeLV (FeLV-KT) had progressive decrease in the number of CFU-F at 2, 4, and 6 weeks after infection. The number of CFU-F in FeLV-KT-infected cats ranged from 38 to 70% of the preinoculation CFU-F value. Of 3 cats with FeLV-KT-induced suppression of CFU-F, 2 developed fatal nonregenerative anemia. Cats infected with the Rickard isolate of FeLV (FeLV-R) had more moderate decrease in the number of CFU-F at 2, 4, and 6 weeks after infection. The number of CFU-F in FeLV-R-infected cats ranged from 62 to 82% of the preinoculation CFU-F value. The FeLV-R-infected cats did not become anemic.     

Susceptibility of canine, feline and human erythrocytes to oxidant-mediated injury

e relative susceptibilities of feline, canine and human erythrocytes to in vitro hydrogen peroxide-induced lipid peroxidation and hemolysis were studied. At 15 minutes following exposure to hydrogen peroxide, cat erythrocytes had higher concentrations of lipid peroxidation by-products and a greater percent hemolysis as compared to dogs and humans. Erythrocytes from cats with induced sterile abscesses had lower concentrations of the antioxidant glutathione, but they did not have detectable concentrations of lipid peroxides nor were they more susceptible to in vitro lipid peroxidation or hemolysis.     

Antioxidant prevention of Heinz body formation and oxidative injury in cats

OBJECTIVE: To determine the effectiveness of 3 antioxidants in preventing Heinz body anemia in cats. DESIGN: Prospective study. ANIMALS: 44 specific-pathogen-free healthy cats. PROCEDURE: Cats were housed individually, divided randomly into 4 groups, and given the following orally every 12 hours: empty gelcaps (control cats), N-acetylcysteine (NAC, 100 mg/kg of body weight), vitamin E (d,l-alpha-tocopherol; 400 IU), or ascorbate (250 mg). After 2 weeks, Heinz bodies were induced by dietary onion powder (OP; 1% or 3% of dry matter) or propylene glycol (PG, 8% wt/vol in drinking water) for an additional 3 weeks. Intake of treated water or food was recorded daily. Body weight, PCV, Heinz body and reticulocyte percentages, reduced glutathione concentration, and total antioxidant status were measured twice weekly in all cats. RESULTS: Heinz body percentage and degree of anemia did not differ significantly among cats receiving antioxidants and control cats except in cats that ingested water containing PG, in which antioxidant supplementation was associated with a decrease in water intake. Of cats that were fed a diet that contained OP, cats that received NAC had significantly higher reduced glutathione concentrations, compared with other cats in the experiment. Total antioxidant status did not consistently correlate with antioxidant supplementation or type of oxidant administered (ie, OP or PG). CONCLUSIONS AND CLINICAL RELEVANCE: Although the effect of antioxidant supplementation on Heinz body anemia in cats was minimal, antioxidants may have subclinical biochemical effects such as GSH sparing that may be important against milder forms of oxidative stress.     

Comparative effects of proligestone and megestrol acetate on basal plasma glucose concentrations and cortisol responses to exogenous adrenocorticotrophic hormone in cats

Cats were given megestrol acetate (MA, 5 mg once daily for 14 days), subcutaneous proligestone (PRG, 100 mg on two occasions one week apart) or subcutaneous saline (1 ml as for PRG). In cats given saline (n = 6) basal cortical concentrations, cortisol concentrations after adrenocorticotrophic hormone (ACTH) administration and fasting blood glucose concentrations did not change significantly during the following seven weeks. Cats given MA (n = 7) developed suppression of basal and ACTH-stimulated cortisol concentrations and fasting hyperglycaemia during treatment. Effects on cortisol persisted for two weeks after MA dosage ceased. In cats given PRG (n = 7), basal cortisol concentrations were reduced overall, but only three cats had persistently suppressed post-ACTH cortisol concentrations. Adrenal suppression continued for 14 weeks in one of these and for at least 22 weeks in two cats. Fasting blood glucose concentrations were unchanged in PRG-treated cats.     

Expression of erythropoietin in cats treated with a recombinant adeno-associated viral vector

OBJECTIVE: To characterize the biological effects of IM administration of a recombinant adeno-associated virus serotype 2 (rAAV2) vector containing feline erythropoietin (fEPO) cDNA and determine whether readministration of the vector or removal of muscle tissue at the injection sites alters those effects. ANIMALS: 10 healthy 7-week-old specific pathogen-free cats. PROCEDURE: Cats received 1 X 10(7) infective units (iU; n = 3), 1 X 10(8) iU (3), or 1 X 10(9) iU (2) of rAAV2-fEPO vector IM (day 0). Two control cats received an rAAV2 vector containing the LacZ gene (1 X 10(9) iU, IM). In all cats, hematologic variables and serum fEPO concentration were measured at intervals; anti-rAAV2 antibody titer was measured on day 227. In cats that did not respond to treatment, the rAAV2-fEPO vector was readministered. Injection sites were subsequently surgically removed. RESULTS: Compared with control cats, cats treated with 1 X 10(9) iU of rAAV2-fEPO vector had increased Hct and serum fEPO concentrations. One of these cats developed pure RBC aplasia; its Hct normalized following injection site excision. Cats receiving lower doses of vector had no response; on retreatment, 1 of those cats developed sustained erythrocytosis that persisted despite injection site removal and the others did not respond or responded transiently. Antibodies against rAAV2 were detected in all vector-treated cats. CONCLUSIONS AND CLINICAL RELEVANCE: Gene therapy may be an effective treatment for cats with hypoproliferative anemia. However, rAAV2-fEPO vector administration may result in pure RBC aplasia or pathologic erythrocytosis, and injection site removal does not consistently abolish the biological response.     

Clinical and lymphohematologic responses after bone marrow transplantation in sibling and unrelated donor-recipient pairs of cats

Conditions necessary for establishment of a graft, posttransplant supportive care and complications, and lymphohematopoietic reconstitution after bone marrow transplantation were evaluated in 7 cats. Donor-recipient pairs were selected on the basis of low mutual reactivity in one-way mixed lymphocyte reactions. Before transplantation, cats were given marrow ablative (7 Gray) total-body gamma irradiation. Cyclosporine A was administered to cat 7, which was given marrow from an unrelated donor. Rapid hematologic recovery was attained in 5 of 5 (cats 1 to 5) sibling bone marrow recipients and 1 (cat 7; cyclosporine A-treated) of 2 recipients from unrelated donors. Lymphocyte recovery was prolonged, requiring up to 100 days to attain reference concentrations. Lymphocyte blastogenic responses were below reference range in 2 of 3 cats (cats 1 and 3) examined approximately 1 to 3 months after transplantation. Serum IgG concentrations determined 1 to 6 months after transplantation were within reference range in cats 1 to 5 which were given sibling bone marrow. Fatal infections did not develop in cats that had established grafts. Antimicrobial-responsive fevers did develop, but were generally detected only when granulocyte counts were low (less than 1 x 10(9) cells/L). Clinical signs of disease in the immediate posttransplant period consisted of hepatic lipidosis (fatal) in cat 4, hepatitis (mild graft-vs-host disease) in cat 3, and immune-mediated hemolytic anemia and thrombocytopenia in cat 7. Cats with hepatitis and immune-mediated disease responded to immunosuppressive therapy.     

Experimental infection of domestic cats (Felis domesticus) with Cytauxzoon manul from Pallas' cats (Otocolobus manul)

In a random, blind study, six domestic cats were assigned to two treatment groups that received either sterile water or dexamethasone by subcutaneous injection prior to intravenous inoculation with Pallas' cat (Otocolobus manul) blood infected with Cytauxzoon manul. A seventh domestic cat served as a control and was inoculated only with sterile water. Cats were monitored for clinical signs consistent with cytauxzoonosis, and periodically screened for hemoparasitemia. All domestic cats (6/6) that received Pallas' cat blood infected with C. manul developed a low but detectible parasitemia by 9 days post-inoculation, yet remained clinically healthy. All domestic cats (7/7) were subsequently challenged with Cytauxzoon felis and developed clinical signs typical of cytauxzoonosis within 5 days post-challenge. Affected animals were euthanized and cytauxzoonosis was confirmed by histopathology. While inoculation of domestic cats with Pallas' cat blood infected with C. manul induced a parasitemia, it did not cause disease or provide protection against challenge with C. felis. Further studies are warranted to determine the potential for interspecies transmission and disease with C. manul.     

Effect of oral administration of L-lysine on conjunctivitis caused by feline herpesvirus in cats

OBJECTIVE: To determine whether oral administration of L-lysine to cats would lessen the severity of conjunctivitis caused by feline herpesvirus (FHV-1). ANIMALS: 8 healthy young adult cats. PROCEDURE: Cats received oral administration of lysine monohydrochloride (500 mg, q 12 h) or placebo (lactose) beginning 6 hours prior to inoculation of virus. The left conjunctival sac received a 50-microl suspension of FHV-1 grown in cell culture (1.8 X 10(8) tissue culture infective dose50) on day 1. Cats were evaluated and scores given for clinical signs each day for 21 days. Samples for virus isolation were collected from the eye and throat every third day. Plasma lysine and arginine concentrations were measured prior to the study and on days 3, 14, and 22. RESULTS: Cats that received lysine had less severe conjunctivitis than cats that received placebo. Virus isolation results did not differ between the groups. Plasma lysine concentration was significantly higher in cats that received lysine, compared with control cats, whereas plasma arginine concentrations did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of 500 mg of lysine to cats was well tolerated and resulted in less severe manifestations of conjunctivitis caused by FHV-1, compared with cats that received placebo. Oral administration of lysine may be helpful in early treatment for FHV-1 infection by lessening the severity of disease.     

Methionine toxicosis in cats

Cats given DL-methionine (1 g/kg of body weight/day) developed severe hemolytic anemia with marked increase of methemoglobin (MetHb) concentration and Heinz-body formation at treatment-day 6 to 10. Cats fed 0.5 g of methionine/kg for 52 days had a moderate Heinz-body hemolytic anemia with methemoglobinemia at treatment days 17 to 31, but thereafter recovered from the anemia despite continuation of methionine feeding, indicating an adaptation of the cats. In vitro, significant (P less than 0.01) increases of MetHb concentration and Heinz-body formation were observed when RBC were incubated with plasma from cats fed (1 g of methionine/kg) or with 10 mM 3-methylthiopropionate, a product of methionine catabolism. However, these increases were not observed when RBC were incubated with 10 mM methionine. Seemingly, excessive methionine intake leads to production of an intermediate of the methionine catabolism that may affect RBC directly as an intensive oxidizing agent, resulting in an excessive oxidation of hemoglobin to MetHb and Heinz-body formation.     

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.     

Contribution of propylene glycol-induced Heinz body formation to anemia in cats

Propylene glycol (PG) is a common preservative and source of synthetic carbohydrates in soft-moist pet foods. Propylene glycol was fed to cats for 5 weeks at concentrations found in commercial diets (1.6 g/kg of body weight; 12% of diet on a dry-weight basis) and for 3 weeks at concentrations exceeding usual intake (8 g/kg; 41% of diet). There was a dose-dependent increase in Heinz body percentage to 28% in cats fed the low dose of PG and to 92% in cats fed the high dose. Erythrocyte half-life, measured using [14C]-cyanate hemoglobin (Hb), decreased significantly (P less than 0.05) by 18.8% and 60% in cats fed the low and high PG doses, respectively. The PCV in cats fed the low dose was unaffected, whereas cats fed the high dose had a mean (+/- SEM) decrease in PCV from 33.5 +/- 1.05% to 26.3 +/- 1.45%, accompanied by punctate reticulocytosis and bone marrow erythroid hyperplasia. A dose-dependent increase in iron pigment was found in the liver and spleen of all cats. In cats fed the low dose of PG, erythrocyte reduced glutathione concentration actually increased from 7.02 +/- 0.56 to 9.74 +/- 0.69 mumol/g of Hb, but decreased to 2.96 +/- 0.27 mumol/g of Hb in cats fed the high dose. There was no significant increase in methemoglobin concentration. These results indicated that PG cannot be considered innocuous even at concentrations consumed by cats eating commercial diets. Heinz body-induced acceleration of RBC destruction develops in a dose-dependent manner, so that cats with greater food intake, ie, lactating queens and nursing kittens, are at greater risk for development of PG-induced Heinz body hemolytic anemia.     

Characterization of the anemia of inflammatory disease in cats with abscesses, pyothorax, or fat necrosis

The purpose of this study was to describe the anemia of inflammatory disease (AID) in cats with naturally-occurring inflammatory diseases, such as abscesses (n = 12), pyothorax (n = 6), and fat necrosis (n = 3). Exclusion criteria were positive FeLV/FIV tests, neoplasia, nephro-, hepato- or endocrinopathies, and blood loss anemia. CBC, clinical biochemistry, measurements of serum erythropoietin, iron, total iron-binding capacity (TIBC), ferritin, acute phase proteins, erythrocytic osmotic fragility (OF), and Coombs' tests were performed. A decrease in hematocrit of 1-28% (median, 10%) occurred within 3-16 days (median, 8 days). The anemia was mild (n = 11), moderate (n = 8), or severe (n = 2). In most cases it was normocytic normochromic, non-regenerative (n = 18), or mildly regenerative (n = 3). Sixteen cats had leukocytosis and 5 mild hyperbilirubinemia. The Coombs' test results were negative for 8 cats and positive for 1 cat. OF was increased in 2 out of 14 cats. Hypoalbuminemia (n = 18) and hyperglobulinemia (n = 16) resulted in a lowered albumin/globulin-ratio in 19 cats. Iron and TIBC were low in 2/19 and 6 /19 cats, respectively. The ferritin concentrations were normal in 7 cats and increased in 12 cats. The acute phase proteins alpha1-acid-glycoprotein and haptoglobin were increased in 14/14 and 13/14 cats, respectively. Erythropoietin was normal (n = 4), mildly increased (n = 7) or severely increased (1). Two cats were euthanized due to their underlying disease, 3 cats needed blood transfusions. AID in cats is usually mild to moderate, non-regenerative, and normocytic normochromic. It can be clinically relevant causing severe and transfusion-dependent anemia. AID seems to be multifactorial with evidence of iron sequestration, decreased RBC survival, and insufficient erythropoietin production and bone marrow response. Specific and supportive therapy, including transfusions, can reverse these processes.     

Effects of oral administration of orotic acid on hepatic morphologic characteristics and serum biochemical variables in cats.

OBJECTIVE: To evaluate orotic acid (OA) as a possible etiologic factor in cats with idiopathic hepatic lipidosis (HL). ANIMALS: 20 clinically normal adult female cats. PROCEDURE: Cats were fed a control diet or a diet containing less protein. On day 1 of the control period, blood, urine, and liver biopsy specimens were obtained. Each cat was given an oral dose of water daily. On days 8, 15, and 22, blood and urine specimens were collected as on day 1. On day 29, liver, blood, and urine samples were obtained as on day 1. After a resting period of 30 to 60 days, cats were treated with orotic acid. Serum biochemical analyses, urinary OA-to-creatinine ratios, and liver biopsy specimens were evaluated. Cats were given OA orally (suspension or capsules) for 29 days. Sample collection and data obtained were identical to those described for the control period. RESULTS: Urinary OA-to-creatinine ratios were significantly higher in all treated cats, but ratios were significantly higher in those receiving OA in capsules than in those receiving OA in suspension. Diet or treatment did not alter hepatic biochemical or histologic variables significantly. However, 7 cats given the highest dose of OA in capsules developed azotemia, urolithiasis, and renal changes. CONCLUSIONS: Most concentrations of OA used in this study did not induce HL in cats during a 29-day period, but the highest dosage used did result in renal disease. CLINICAL RELEVANCE: Orotic acid does not appear to be involved in the genesis of HL in cats.     

Quantitative studies of erythropoiesis in the clinically normal, phlebotomized, and feline leukemia virus-infected cat

Erythropoiesis was evaluated in 5 cats at base line with normal PCV and then in the same cats with anemia induced by phlebotomy and in 5 other cats with nonregenerative anemia from community-acquired feline leukemia virus (FeLV) infection. The hematologic evaluation included complete blood cell and reticulocyte counts, marrow morphologic features, determination of serum erythropoietin concentrations by radioimmunoassay, ferrokinetic studies, and in vitro marrow culture of early erythroid progenitors (erythroid burst-forming units; BFU-E) and late erythroid progenitors (erythroid colony-forming units; CFU-E). Phlebotomized cats developed marrow erythroid hyperplasia and an increased reticulocyte count. Ferrokinetic studies revealed an increase in plasma iron turnover from 1.4 to 3.8 mg of Fe/dl of blood/day and RBC use from 50.4% to 78.5%. The mean CFU-E number and CFU-E/BFU-E ratio increased after phlebotomy, but the increase was not significant (P greater than 0.05). Serum erythropoietin values did increase significantly. In FeLV-infected cats, a nonregenerative anemia was demonstrated by marrow erythroid hypoplasia and a low total reticulocyte count. An increased percentage of rubriblasts and prorubricytes was observed in 4 of the 5 cats. Although serum erythropoietin values were high (321 +/- 123 mU/ml vs normal 14 +/- 1 mU/ml), ferrokinetic data revealed decreased erythropoiesis. Marrow culture studies in the FeLV-infected cats also revealed low numbers of BFU-E and CFU-E, but normal numbers of granulocyte-macrophage progenitors remained. Seemingly, the FeLV infection impaired the ability of feline marrow to respond physiologically to anemia.     

Effect of immunization with bovine luteinizing hormone receptor on ovarian function in cats

OBJECTIVE: To determine the effect of immunization with bovine luteinizing hormone receptor (LH-R) on ovarian function of cats. ANIMALS: 9 adult female domestic cats. PROCEDURE: 7 cats were immunized with 0.5 mg of LH-R encapsulated in a silastic subdermal implant (3 x 10 mm); 2 served as control cats. Receptors had 80% specific binding to 125I-human chorionic gonadotropin with a binding capacity of 2,682 pM/mg. Cats received booster injections of LH-R. Cats were induced to ovulate with luteinizing hormone (LH) releasing hormone on day 345. Samples of venous blood and vaginal cells were collected through day 395. Observation of estrus behavior continued until day 516. Serum concentrations of estradiol, progesterone, thyroid gland hormones, LH, and LH-R antibody were determined. RESULTS: LH-R antibody was detected in the sera of immunized cats within 21 days after implantation. Detection of LH-R antibody was associated with suppression of serum progesterone to < or = 0.5 ng/mL during the study period, compared with concentrations of 5 to 10 ng/mL in control cats. Immunized cats did not display signs of estrus. Release of LH after administration of LH-releasing hormone indicated an intact hypothalamic-pituitary axis but poor corpus luteum function. Serum estradiol concentrations remained between 30 to 40 pg/mL in immunized and control cats. With the decrease antibody titers, hormone concentrations returned to a pattern consistent with that during fertility. CONCLUSIONS AND CLINICAL RELEVANCE: Active immunization with LH-R suppressed corpus luteum function in cats. The effect was reversible. An LH-R-based antifertility vaccine may have clinical application in other vertebrates.     

Evaluation of the effects of ischemic injury and ureteral obstruction on delayed graft function in cats after renal autotransplantation

OBJECTIVE: To determine the relative importance of ischemic injury to delayed graft function (DGF) in cats. STUDY DESIGN: Experimental study. ANIMALS: Six intact female cats. METHODS: Cats had renal autograft transplantation without ureteral transection and reimplantation and a contralateral nephrectomy. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured regularly and abdominal ultrasound was performed before surgery, the day after surgery and twice weekly thereafter. Ultrasound-guided renal biopsy was performed on day 7. Cats were euthanatized on day 21. Histology of the autograft, ureter, bladder, vascular anastomoses sites, and contralateral kidney were performed. Observations were compared with those from an historic group of research cats that had extravesicular ureteroneocystostomy and contralateral nephrectomy. RESULTS: Five cats completed the study. Serum creatinine and BUN concentrations increased after surgery, peaking at 3.2+/-0.8 and 77.6+/-15.9 mg/dL, respectively, 1-2 days after surgery. Serum creatinine concentration returned to the reference interval by 6 days after surgery. BUN gradually decreased in all cats but did not return to the reference interval by study end. Serum creatinine and BUN concentrations were consistently lower but not significantly so (P=.29 and .56, respectively) compared with the historic ureteroneocystostomy group. No ultrasonographic abnormalities or renal biopsy histologic abnormalities were observed. At necropsy, 1 autograft had generalized interstitial fibrosis. CONCLUSION: Harvesting the renal graft and the ischemia before revascularization causes impaired renal function after engraftment. CLINICAL RELEVANCE: The process of harvesting and reimplanting the renal graft can contribute to DGF in cats, independent of ureteral obstruction.     

Plasma concentrations of tumor necrosis factor-alpha in cats with congestive heart failure

OBJECTIVE: To determine whether plasma concentrations of tumor necrosis factor-alpha (TNF-alpha) are increased in cats with congestive heart failure (CHF) secondary to cardiomyopathy. ANIMALS: 26 adult cats with CHF and cardiomyopathy and 9 healthy control cats. PROCEDURE: Plasma concentrations of TNF-alpha were measured in cats with CHF and cardiomyopathy. Tumor necrosis factor-alpha was measured by quantifying cytotoxic effects of TNF-alpha on L929 murine fibrosarcoma cells. RESULTS: Concentrations of TNF-alpha were increased (0.13 to 3.6 U/ml) in 10 of 26 cats with CHF but were undetectable in the other 16 cats with CHF and all control cats. In 20 of 26 cats with CHF right-sided heart failure (RHF) was evident; TNF-alpha concentrations were increased in 9 of these 20 cats. The remaining 6 cats had left-sided heart failure (LHF); TNF-alpha concentrations were increased in only 1 of these cats. Age of cats with LHF (mean +/- SD, 12.1+/-6.2 years) was not significantly different from age of the cohort with RHF (10.5+/-5.2 years). Body weight of cats with increased TNFalpha concentrations (5.4+/-1.8 kg) was not significantly different from body weight of cats with CHF that did not have measurable concentrations of TNF-alpha (4.7+/-1.6 kg). CONCLUSIONS AND CLINICAL RELEVANCE: Concentrations of TNF-alpha were increased in many cats with CHF. Cats with RHF were most likely to have increased TNF-alpha concentrations. Increased plasma concentrations of TNF-alpha in cats with CHF may offer insights into the pathophysiologic mechanisms of heart failure and provide targets for therapeutic interventions.