Immunomodulation therapy for feline leukemia virus infection.

Clinically ill feline leukemia virus (FeLV)-infected cats, treated with Staphylococcus protein A (SPA) or oral interferon alpha (IFN), or both, were compared with cats treated with saline (SAL). Nine cats received SPA/SAL, nine received SPA/IFN, 10 received SAL/IFN, and eight received SAL/SAL. Twelve cats survived and completed the 100-week therapy. Significantly more owners of cats treated with SPA/SAL thought their cat's health improved during treatment compared to owners of cats treated with SAL/SAL (P=0.05, pair-wise comparison) or SPA/IFN (P=0.05, pair-wise comparison). No significant differences in body weight, temperature, hematocrit, red blood cell counts, mean corpuscular hemoglobin concentration, reticulocyte counts, white blood cell or neutrophil numbers, lymphocyte concentrations, bone-marrow cytopathology, FeLV status, survival time, activity, or appetite scores were observed. No significant differences in the owners' subjective assessment of their cat's health following treatment with SAL/IFN, SPA/IFN, or SAL/SAL were seen. Therapy with SPA as a single agent results in the owners' subjective impression of improved health of their FeLV-infected cats.

Plasma granulocyte colony-stimulating factor concentrations in neutropenic, parvoviral enteritis-infected puppies.

We evaluated the temporal relationship between neutrophil numbers and plasma granulocyte colony-stimulating factor (G-CSF) concentrations in dogs infected with canine parvovirus, a common infectious cause of neutropenia. G-CSF is produced in response to neutropenia, infection, or inflammation, and results in the production and release of neutrophils from the bone marrow. Adequate numbers of functional neutrophils are necessary for protection from infection, and the timely production of G-CSF is a crucial response to certain diseases. The relationship between peripheral neutrophil numbers and plasma G-CSF concentrations during the course of an infectious disease characterized by neutropenia has not been described previously in dogs. Eight mixed-breed puppies were given an oronasal challenge with canine parvovirus, and peripheral neutrophil numbers as well as plasma G-CSF concentrations were measured daily. G-CSF was not detectable in plasma of any dog before the onset of neutropenia, but G-CSF became detectable just after the onset of neutropenia in the 7 dogs that developed clinical illness. Neutropenia persisted or worsened for at least 2 days after plasma G-CSF became detectable in all 7 dogs. Neutrophil nadir, the highest plasma G-CSF concentrations, and the most severe clinical illness occurred concurrently in most dogs. Although 1 dog died while still neutropenic, plasma G-CSF concentrations declined before resolution of neutropenia in the other 6 dogs, and were again below the limits of detection in 5 of the 6 dogs at the time of resolution.

Ionized and total magnesium concentrations in blood from dogs with naturally acquired parvoviral enteritis.

OBJECTIVE: To determine whether pretreatment total and ionized blood magnesium concentrations were associated with outcome for dogs with parvoviral enteritis and whether ionized magnesium concentration was related to total magnesium concentration or other laboratory values. DESIGN: Prospective cohort study. ANIMALS: 61 healthy dogs and 72 dogs with parvoviral enteritis. PROCEDURE: Total, ionized, and pH-normalized ionized magnesium concentrations, ionized and pH-normalized ionized calcium concentrations, pH, sodium and potassium concentrations, and Hct were measured prior to treatment. chi 2 Analyses were used to test for associations between outcome and age and between outcome and treatment with antiendotoxin antibody. Pearson's correlation coefficients were calculated to determine whether ionized magnesium concentration was linearly associated with other laboratory values. RESULTS: Total and ionized magnesium concentrations were not significantly different between healthy dogs and dogs with parvoviral enteritis or between dogs surviving and those not surviving parvoviral enteritis. The only laboratory value strongly correlated with ionized magnesium concentration was pH-normalized ionized magnesium concentration. Of the factors tested, none were significantly associated with outcome, except that dogs 16 weeks old or less treated with antiendotoxin antibody were significantly more likely to die than were dogs 16 weeks old or less that were not treated with antiendotoxin antibody. CLINICAL IMPLICATIONS: Total and ionized blood magnesium concentrations cannot be used to consistently predict outcome for dogs with parvoviral enteritis. Antiendotoxin antibody should be used with caution in dogs 16 weeks old or less.

Delivery of laboratory data with World Wide Web technology.

We have developed an experimental World Wide Web (WWW) based system to deliver laboratory results to clinicians in our Veterinary Medical Teaching Hospital. Laboratory results are generated by the clinical pathology section of our Veterinary Medical Diagnostic Laboratory and stored in a legacy information system. This system does not interface directly to the hospital information system, and it cannot be accessed directly by clinicians. Our "meta" system first parses routine print reports and then instantiates the data into a modern, open-architecture relational database using a data model constructed with currently accepted international standards for data representation and communication. The system does not affect either of the existing legacy systems. Location-independent delivery of patient data is via a secure WWW based system which maximizes usability and allows "value-added" graphic representations. The data can be viewed with any web browser. Future extensibility and intra- and inter-institutional compatibility served as key design criteria. The system is in the process of being evaluated using accepted methods of assessment of information technologies.

Heritability and biochemistry of gangliosidosis in emus (Dromaius novaehollandiae).

The progeny of two emu breeder pairs, which had a history of producing offspring with gangliosidosis, were monitored for 15 mo. DNA fingerprinting revealed that individuals in each breeder pair were not related to each other. One breeder pair had 13 progeny that reached or exceeded the age of 1 mo, and six of these progeny developed gangliosidosis. The mean age at which these affected emus were euthanatized, with distinct neurologic disease, or died was 5.7 mo. The second emu pair had 13 progeny, seven of which developed gangliosidosis, with a mean age of euthanasia/death of 4.6 mo. Affected emus died or were euthanatized from 2 to 8 mo of age. The primary clinical sign in the affected emus was mild to severe ataxia. Severe hemorrhage into the body cavity or the muscles of the thigh was noted in 8 of 13 of the affected emus. Brain ganglioside levels were evaluated in six of the affected emus and six controls. Significant increases (P < 0.05) in gangliosides GM1 and GM3 were noted, with 2.3- and 4.9-fold increases in these two gangliosides, respectively, in affected emus. Furthermore, the diseased emu brains contained ganglioside GM2, whereas this monosialoganglioside was undetectable in the brains of normal controls. Total mean brain ganglioside sialic acid in affected emus was increased 3.3-fold in comparison with controls. Serum chemistries revealed elevated cholesterol and decreased uric acid levels in affected emus. Gangliosidosis in emus is an inherited disease process that, in the current study, caused 50% mortality in the progeny of two emu breeder pairs. The elimination of this lethal gene from emu breeder stock is essential for the long-term economic viability of the United States emu industry.

Methodologic considerations for the use of canine in vivo aged biotinylated erythrocytes to study RBC senescence.

Biotinylation of erythrocytes has been developed in rabbits as a tool to retrieve labeled cells following various periods in circulation. This retrieval capability allows biochemical studies to be conducted on red blood cells (RBC) that have aged for desired times in vivo. However, because erythrocyte life span is much shorter in rabbits than in humans, and because cell removal is measurably age-independent in rabbits, we have sought to validate the same protocol in dogs, whose cell life span and age-dependent removal characteristics are similar to humans'. Canine RBC were biotinylated in vivo by infusion of N-hydroxysuccinimidyl biotin dissolved in dimethylacetamide or dimethylsulfoxide. Cell life spans were evaluated using 14C-cyanate labeling followed by scintillation counting or avidin-FITC labeling followed by flow cytometry. Both methods gave identical results. The life span of the biotin-conjugated cells was found to be normal (approximately 110 days), and the stability of the biotin ligand was adequate for efficient retrieval of cells using avidin-coated magnetic beads (magnetic cell sorting [MACS]). From each isolation, approximately 20 microL of packed biotinylated cells of approximately 90% purity (i.e., 10% contamination by unlabeled cells) could be harvested. On average, approximately 60% of the biotinylated cells in any sample could be retrieved. Either multiple isolations or use of larger collection columns will facilitate collection of cell numbers sufficient for biochemical tests. After incorporating several modifications in the previous biotinylation protocol that were required for adaptation to the dog, the methodology can be used to study red cell senescence in an animal that has several pertinent similarities to humans.

Senescence of canine biotinylated erythrocytes: increased autologous immunoglobulin binding occurs on erythrocytes aged in vivo for 104 to 110 days.

We have evaluated senescence related changes in canine red blood cells (RBCs) using the biotinylation system, where RBCs are labeled in vivo with biotin at the beginning of their life span, and retrieved from circulation on immobilized avidin at the end of their life span. This approach avoids the controversial use of density gradient centrifugation to collect presumably old RBCs. Furthermore, the dog is an appropriate model for human RBC senescence because it has a low degree of random RBC loss and a similarly long RBC life span (approximately 110 days). Two dogs had 97% to 100% of their circulating RBCs biotinylated by infusion of N-hydroxysuccinimido biotin (Clontech, Palo Alto, CA; Calbiochem, La Jolla, CA) dissolved in dimethyl sulfoxide. At postbiotinylation days 104 and 107 for one dog and day 110 for the other dog, biotinylated RBCs were isolated by magnetic cell sorting and analyzed for the presence of autologous IgG using 125I-labeled sheep-antidog IgG (SAD IgG). On all 3 days, there were at least three times more SAD IgG molecules per RBC on senescent biotinylated RBCs than on control (unfractionated) RBCs (day 104: 11,677 v 3,399; day 107: 6,710 v 2,115; day 110: 6,042 v 1,838 molecules of SAD IgG per senescent v control RBC). Furthermore, it is unlikely that an immune response to the conjugated biotin had been elicited, because fresh in vitro biotinylated RBCs that were incubated in autologous plasma (taken after exposure to circulating biotinylated RBCs for 113 days) and then exposed to the SAD IgG showed no increase in antibody binding over control (non-biotinylated) RBCs (1,431 v 1,378 cpm/10(8) biotinylated v control RBCs; P > .20). These results suggest that senescence of canine biotinylated RBCs is characterized by binding of autologous IgG and that antibiotin antibodies do not contribute to this process.

Ultracentrifugal and electrophoretic characteristics of the plasma lipoproteins of miniature schnauzer dogs with idiopathic hyperlipoproteinemia.

To better characterize the idiopathic hyperlipoproteinemia of Miniature Schnauzer dogs, the plasma lipoproteins of 20 Miniature Schnauzers (MS) and 11 dogs of other breeds (DOB) were evaluated by ultracentrifugation, electrophoresis, and biochemical tests. Seventeen MS were healthy; 3 had diabetes mellitus. Plasma from 6 of 17 healthy and all 3 diabetic MS was visibly lipemic. Lipemia was slight to marked in healthy lipemic MS, and marked in diabetic ones. All DOB had clear plasma; 8 were healthy and 3 had diabetes. All healthy lipemic MS and diabetic lipemic MS had hypertriglyceridemia associated with excess very low density lipoproteins. Chylomicronemia was present in 4 of 6 healthy lipemic MS and all 3 diabetic lipemic MS. Lipoproteins with ultracentrifugal and electrophoretic characteristics of normal low density lipoprotein were lacking in 4 of 6 healthy lipemic MS. The lipoprotein patterns of 4 of 11 healthy nonlipemic MS were characterized by mild hypertriglyceridemia associated with increased very low density lipoproteins and a lack of lipoproteins with characteristics of normal low density lipoproteins. Lipoprotein patterns of diabetic DOB closely resembled those of healthy DOB; those of diabetic lipemic MS resembled those of markedly lipemic healthy lipemic MS. In conclusion, the hyperlipoproteinemia of Miniature Schnauzers is characterized by increased very low density lipoproteins with or without accompanying chylomicronemia; some affected dogs may have decreased low density lipoproteins.

An overview of hemostasis.

Hemostasis is a remarkable and a remarkably complex mechanism. It can maintain blood in a fluid state intravascularly but very quickly changes blood to a jellylike mass upon disruption of the vasculature. This review will give a synopsis of the 3 phases of hemostasis: platelet, vascular, and coagulation. Fibrinolysis and control mechanisms of hemostasis will also be covered. In addition, brief descriptions of the clinical and laboratory evaluation of patients and the diagnosis of bleeding disorders will be presented.

Antiviral nucleoside toxicity in canine bone marrow progenitor cells and its relationship to drug permeation.

The most promising nucleoside analogs that are currently undergoing preclinical and clinical testing for anti-HIV activity belong to the dideoxynucleoside group. We have studied the toxicity of 3'-azido,3'-deoxythymidine (AZT), 2',3'-dideoxycytidine (DDC), and 2',3'-dideoxyinosine (DDI) in canine bone marrow progenitor cells in culture. AZT potently inhibited both canine CFU-GM and CFU-E with IC50 values of 2 and 8 mumol/l respectively, while DDC was relatively non-toxic to either progenitor with IC50 of > 200 mumol/l and 80 mumol/l respectively. DDI was mildly toxic to the bone marrow progenitors, with IC50 values of 62 mumol/l for CFU-GM and 70 mumol/l for CFU-E. Dipyridamole, a nucleoside transport inhibitor, did not influence the toxicity of these dideoxynucleosides in either progenitor at concentrations up to 10 mumol/l. Using uridine as the prototype endogenous nucleoside, we have demonstrated that there is a saturable "zero-trans" nucleoside transport system in canine bone marrow mononuclear cells, which is completely inhibited by 1 mumol/l dipyridamole (Ki = 0.02 mumol/l). None of the dideoxynucleosides appeared to be a substrate for this transport system, and dipyridamole did not alter their influx. Permeation of radiolabeled AZT into bone marrow mononuclear cells was slow and non-saturable, while the permeation of DDI was even slower. DDC did not permeate bone marrow cells well, with very little cell accumulation even after 2 hours of equilibration. Our toxicity data from canine bone marrow progenitor cells paralleled the clinical hematotoxicity profiles of these dideoxynucleosides in AIDS patients and suggest that the myelotoxicity of a nucleoside analog is related to its ability to permeate the progenitor cells in question. Canine bone marrow progenitor cultures may serve well as an in vitro model for drug hematotoxicity studies.

Hemoperitoneum secondary to traumatic rupture of an adrenal tumor in a dog.

Hemoperitoneum secondary to traumatic rupture of an adrenocortical adenocarcinoma was diagnosed in a 10-year-old male dog. Immediate surgical attention was required to remove the tumor and to control hemorrhage. The dog appeared to develop transient hypoadrenocorticism after surgery, but recovered with short-term exogenous corticosteroid administration. At 6 months after surgery, the dog was clinically normal.

Effects of acute pancreatitis on circulating lipids in dogs.

Effects of acute pancreatitis on circulating lipids in dogs were evaluated by comparing the serum cholesterol and triglyceride concentrations and plasma lipoprotein electrophoretic patterns of 4 dogs with experimentally induced pancreatitis (EIP), 2 (healthy) sham-operated control (SOC) dogs, and 4 dogs with naturally acquired pancreatitis (NAP) with the concentrations and patterns of 23 healthy, nonoperated control (HNC) dogs. Blood samples were collected once from HNC dogs, 1 to 3 times during the course of the disease in dogs with NAP, and prior to and at 6, 12, 24, 48, 72, and 96 hours after induction of pancreatitis in dogs with EIP or after the sham operation in the SOC dogs. The dogs with EIP did not have turbid serum and did not develop hypercholesterolemia or hypertriglyceridemia. Three of the dogs with NAP had turbid serum and hypertriglyceridemia, and 3 had hypercholesterolemia. The electrophoretic tracings of HNC dogs had predominant alpha-1 peaks and small beta peaks; 2 of the HNC dogs also had small alpha-2 peaks. The tracings of dogs with EIP were similar to those of HNC dogs until 48 to 72 hours after induction of pancreatitis, when dogs with EIP developed increased beta lipoproteins, decreased alpha-1 lipoproteins, and movement of lipoproteins into the alpha-2 zone. The tracings of SOC dogs were similar to those of HNC dogs at all times. Compared with HNC dogs, dogs with NAP all had increased beta lipoproteins, and 2 had decreased alpha-2 lipoproteins. Two dogs with NAP had additional lipoprotein alterations, unlike any seen in dogs with EIP.

Evaluation of a spectrophotometric method for canine serum lipase determination.

The British antilewisite butyrate-dithionitrobenzoate (BALB-DTNB) spectrophotometric serum lipase assay was evaluated for precision, accuracy, and diagnostic usefulness in analyzing canine sera. Sera samples from clinically healthy dogs, dogs with experimentally induced pancreatitis, and dogs with spontaneous pancreatitis were analyzed. A titrimetric method of serum lipase determination was used for comparison. Although the BALB-DTNB method was not found to be precise or accurate for determining the lipase activity of canine serum samples, it seemed to be at least as diagnostically useful as the titrimetric procedure. The small sample size requirement and the speed of analysis of the BALB-DTNB procedure are advantages of this method over the titrimetric method, and thus, its use in place of the titrimetric method is justified. A laboratory reference range of 3 to 37 IU/L was determined for canine serum.

Effects of repeated endotoxin injections on prostanoids, hemodynamics, endothelial cells, and survival in ponies.

The objectives of this study were to determine the pathophysiological effects of increasing amounts of endotoxin administered intraperitoneally (IP) for 24 hr at which time an intravenous (IV) injection of endotoxin was given. The ability of flunixin meglumine (FM), a nonsteroidal antiinflammatory drug with antiprostaglandin activity, to provide protective effects was also determined. Eight ponies were divided into two groups of four ponies each; one group (untreated) received endotoxin only and the other group (treated) received endotoxin while being treated with flunixin. Hemodynamic and serum prostanoid changes were recorded for 26 hr during which time five IP and one IV endotoxin injections were given. Both groups behaved similarly until the intravenous endotoxin injection at 24 hr. At that time, the protective effects of flunixin became apparent by preventing increases in thromboxane and prostacyclin concentrations and by maintaining cardiac output, systemic arterial blood pressure, and blood flow to critical organs. Electron microscopic examination of pulmonary arteries of untreated animals revealed extensive endothelial cell damage while treatment with FM reduced this damage. A parallel study involving survival time in two groups of eight ponies each was also conducted using the same endotoxin and treatment protocol. At the end of 7 days, two of eight untreated ponies survived while six of eight treated ponies survived. It was concluded that FM prevented the release of prostanoids, maintained hemodynamics and blood flow nearer pre-endotoxin values, reduced vascular endothelial cell damage, and improved survival.

Citrinin mycotoxicosis in the rabbit: clinicopathological alterations.

Citrinin, a nephrotoxic mycotoxin, was dissolved in 0.5 N-NaOH neutralized with HCl and given in a single oral dose of 120 mg/kg (Trial I) or 80 or 100 mg/kg (Trial II) to male New Zealand white rabbits weighing 2.0-2.7 kg. In Trial I, sequential measurements of clinicopathological parameters were made over a 24-hr period. Azotaemia and metabolic acidosis with haemoconcentration and hypokalaemia developed within 4-12 hr. In Trial II, clinicopathological and urinary parameters were measured daily for 7 days. Increased blood urea nitrogen and serum-creatine levels and decreased creatinine clearance indicated renal failure; these values were most abnormal on days 2-4, returning to normal or near normal by day 7 in rabbits that survived. Urine analysis indicated tubular dysfunction and necrosis with glucosuria, isosthenuria and cylindruria; most urinary parameters were normal by day 7.

Support of an anephric dog for 54 days with ambulatory peritoneal dialysis and a newly designed peritoneal catheter.

A bilaterally nephrectomized dog was successfully supported with peritoneal dialysis for 54 days, using a radically new design of access catheter and a human dialysis schedule designated as continuous ambulatory peritoneal dialysis. The dog remained active and alert with a stabilized blood urea nitrogen of 30 to 40 mg/dl and a serum creatinine concentration of 4 to 6.5 mg/dl. Problems encountered with the peritoneal dialysis included the propensity for developing peritonitis, anorexia, and a significant plasma protein loss in the dialysate fluid as result of leakage across the peritoneum. Protein loss coupled with anorexia produced a catabolic state, and the animal was euthanatized because of this, at postnephrectomy day 54. The development of a new catheter design alleviated the drainage problems of the straight tube Tenckhoff catheter. Its use coupled with the continuous ambulatory peritoneal dialysis schedule and detailed management techniques allowed using the anephric dog as a model of uremia. In addition, peritoneal dialysis could be a viable treatment for animals presenting with acute reversible anuric or oliguric renal failure where conservative medical management with fluids and diuretics has failed to give clinical improvement.

Studies on the sequential development and pathogenesis of citrinin mycotoxicosis in turkeys and ducklings.

The toxic effects of citrinin in turkeys and ducklings was studied in four trials. Citrinin dissolved in dimethyl sulfoxide-70% ethanol solution (3:1, volume/volume) was administered by gavage to male turkey poults and male white Pekin ducklings. When seven-day-old ducklings were given doses of citrinin between 30 to 110 mg/kg body weight, most of the treated ducklings which died (49/80) did so within four to 12 hours. Blood samples were collected sequentially at 3, 6, 12, and 24 hours after administration from seven-day-old ducklings given the single lethal dose (LD50). The alterations included hyperkalemia (P less than or equal to 0.01) and metabolic acidosis characterized by reduced blood pH (P less than or equal to 0.01) and base excess (P less than or equal to 0.01). Fourteen-day-old turkeys and ducklings given 56 or 57 mg/kg, respectively, were killed at 1, 3, 6, 12, 24, 48, and 72 hours after treatment. The principal alteration in both species was nephrosis that was more severe in turkeys than in ducklings. Tubular necrosis was the dominant lesion at three to 72 hours in turkeys and at six to 24 hours in ducklings. Hepatic and lymphoid lesions occurred in both turkeys and ducklings treated with citrinin.

Experimental production of neonatal isoerythrolysis in the foal.

Serological evidence with or without clinical signs of neonatal isoerythrolysis was experimentally produced in 6 of 8 foals born to mares allo-immunized with washed erythrocytes from the stallion. Blood group antigens were determined in all mares, stallions and foals, and the incompatible antigenic factor(s) responsible for the disease were defined. In 5 of 8 foals born to alloimmunized mares, a single antigenic factor difference accounted for the erythrocyte incompatibility between mare and foal. The erythrocyte antigen suspected as the most responsible for isoerythrolysis observed was A1. Agglutinin and hemolysin titers were measured in mare serum and colostrum. Of the presuckle anti-foal erythrocyte titers, colostral and hemolysins titers were greater than serum and agglutinin titers respectively. Foals were allowed to nurse and treatment of affected foals was not attempted which allowed full expression of disease and outcome.

Evaluation of a series of testing procedures to predict neonatal isoerythrolysis in the foal.

A series of modified (field) tests were compared to a crossmatch between mare and foal for their reliability in predicting neonatal isoerythrolysis (NI) in eight foals born to experimentally alloimmunized mares. In the field tests, mare's serum, plasma and colostrum were combined with foal erythrocytes washed by a modified procedure to determine which combination was the best predictor of impending NI. A consistent grading system for agglutination and hemolysis was employed. The field tests using mare's plasma demonstrated less agglutination and hemolysis than tests where serum was employed. Immediate assessment of agglutination failed to demonstrate agglutinin activity when compared to tests where incubation was included. Rouleaux formation posed a problem in interpretation of minor agglutination, however the grading of hemolysis was simpler, quicker, and more accurate. The field test that was most reliable when compared to the crossmatch and presuckle anti-foal erythrocyte titers in demonstrating agglutinins was the combination of mare's serum and foal's erythrocytes. The tests for hemolysin detection in serum and colostrum which incorporated rabbit sera as a complement source were also reliable.