Diagnostic value of intestinal alkaline phosphatase in horse serum

Antiserum directed against equine intestinal Alkaline Phosphatase (ALP) was produced in rabbits and used to develop a sensitive and quantitative assay for the detection of intestinal ALP in equine serum. This assay was then used to measure the half-life of intravenously injected intestinal ALP and to determine if the intestinal ALP was present in normal horse sera, sera from horses presented for lesions not involving the gastrointestinal tract and sera from horses presented with lesions involving the gastrointestinal tract. The results suggest that intestinal ALP is not likely to appear in equine serum even when gastrointestinal disease is present and, therefore, appears to be of no diagnostic value.     

Subcellular location of corticosteroid-induced alkaline phosphatase in canine hepatocytes

Dogs received either 4 mg/kg of prednisone or sterile saline daily for 32 days. Serum samples were assayed every 4 days for total alkaline phosphatase (ALP) and corticosteroid-induced ALP isoenzyme (CIALP) activity. The initial and major increase of serum ALP was attributed to the liver isoenzyme of ALP (LALP), however, CIALP began to increase by day 8 and was significantly increased by day 24. Prior to treatment and on day 32, sections of liver from control and prednisone-treated dogs were stained for ALP activity after blocking the staining activity of LALP with levamisole. The staining activity of CIALP was compared to the staining activity of LALP in liver sections from control dogs and from dogs in which the bile duct was ligated. It was determined that CIALP was located in that area of the hepatocyte membranes which comprise the bile canaliculi.     

Alterations in selected serum biochemical constituents in equids after induced hepatic disease

Effects of induced cholestasis and hepatocellular necrosis and of fasting on serum biochemical constituents including bile acids, IgA, bilirubin, alkaline phosphatase, gamma-glutamyltransferase (GGT), arginase, and the clearance of sodium sulfobromophthalein were studied in 4 groups of equids. The reference value for serum bile acids, as determined by an enzymatic colorimetric procedure for horses and ponies was 5.94 +/- 2.72 mumol/L, there being no statistical difference for horses and ponies. Sample collection at time of feeding had no effect on serum bile acid concentration. Seemingly, serum bile acids, arginase, and GGT were the most sensitive indicators of cholestasis and/or hepatocellular necrosis and would form an essential minimum effective battery of tests to diagnose and prognose hepatic disease in equids. These tests provided a measure of hepatobiliary transport function (bile acids), cell necrosis (arginase), and cholestasis (GGT and bile acids).     

The toxicity of cyclopiazonic acid in weaned pigs

Five- to six-week-old crossbred pigs weighing 5 to 14 kg were given purified cyclopiazonic acid at dosages of 10, 1.0, 0.1, and 0.01 mg/kg body weight orally for 14 days. Clinical signs observed by day 7 in pigs given 10 mg/kg body weight were weakness, inactivity, anorexia, rough hair coats, and reduced body weights. These pigs also developed diarrhea during week 2 of the experiment. The pigs given 1.0 mg/kg body weight had rough hair coats and were moderately inactive during the second week of the experiment. At necropsy, lesions were observed only in pigs given 10 and 1.0 mg/kg body weight of cyclopiazonic acid. Lesions were gastric ulcers, mucosal hyperemia, and hemorrhage throughout the small and large intestine in pigs given 10 mg/kg body weight of cyclopiazonic acid. The pigs also had yellow, fibrononecrotic material in the lumen of the small intestine and pale livers. One pig given 1.0 mg/kg body weight had gastric ulceration. Microscopic lesions in pigs given 10 mg/kg body weight were necrotizing gastroenteritis, focal hepatocellular necrosis, hepatic peripheral lobular fatty change, and focal renal tubular nephrosis with focal suppurative tubulointerstitial nephritis. Pigs given 1.0 mg/kg body weight of cyclopiazonic acid had necrotizing gastritis and villous blunting in the jejunum and ileum.     

Cyclopiazonic acid mycotoxicosis in the dog

The subacute toxic effects of cyclopiazonic acid (CPA; given orally) were characterized in the dog (CPA was purified from cultures of Aspergillus flavus). Four groups of dogs were given CPA in gelatin capsules for 90 days at the following dosage levels: 0.05, 0.25, 0.5, and 1.0 mg/kg of body weight; a 5th group was used as controls. All dogs administered the 0.5 and 1.0 mg of CPA/kg dosages and 1 dog given the 0.25 mg of CPA/kg dosage died or were humanely killed before the scheduled termination of the study. Clinical signs of intoxication appeared 2 to 44 days after dosing was started and consisted of anorexia and, in 1 to 2 days, vomiting, diarrhea, pyrexia, dehydration, weight loss, and CNS depression. Grossly, the entire alimentary tract had diffuse hyperemia with focal areas of hemorrhage and ulceration. Other lesions were renal infarcts, necrotizing epididymitis, and ulcerative dermatitis. Microscopic lesions included ulceration, necrosis, vasculitis, lymphoid necrosis, karyomegaly in several organs, and decreased mitotic activity in intestinal crypt epithelium. Ulcerative and necrotic lesions were usually associated with vascular lesions. Clinical pathologic changes were leukocytosis, neutrophilia, lymphopenia, monocytosis, and increased serum alkaline phosphatase activity.     

A Technique for Automated Quantification of Canine Glucocorticoid-induced Isoenzyme of Alkaline Phosphatase

A sensitive assay for the corticosteroid-induced alkaline phosphatase isoenzyme (CAP), adaptable to most clinical chemistry autoanalyzers, is described and validated. This assay is based on the greater than 98% inhibition of liver alkaline phosphatase isoenzyme (LAP) activity with 4.2 mM levamisole, as compared to the 42% inhibition of CAP activity. Analysis of serum with total alkaline phosphatase (AP) activity within the reference range, resulted in a reference range of 0 to 19 U/L for CAP activity. Analysis of serum from 160 clinical patients with AP activity above the reference range, revealed 73% with increased CAP activity ranging from 20 to 7,000 U/L. The diagnostic significance of this increased CAP activity is discussed.     

Variable very-high-energy gamma-ray emission from the microquasar LS I +61 303

Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and can be used to elucidate the physics of relativistic jets. We report the detection of variable gamma-ray emission above 100 gigaelectron volts from the microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur at a similar orbital phase, which suggests that the emission is periodic. The strongest gamma-ray emission is not observed when the two stars are closest to one another, implying a strong orbital modulation of the emission or absorption processes.     

Landscape pattern in topographically complex landscapes: issues and techniques for analysis

Ecological research provides ample evidence that topography can exert a significant influence on the processes shaping broad-scale landscape vegetation patterns. Studies that ignore this influence run the risk of misinterpreting observations and making inappropriate recommendations to the management community. Unfortunately, the standard methods for landscape pattern analysis are not designed to include topography as a pattern-shaping factor. In this paper, we present a set of techniques designed to incorporate the topographic mosaic into analyses of landscape pattern and dynamics. This toolbox includes adjustments to classic landscape indices that account for non-uniform landscape topography, indices that capture associations and directionality in vegetation pattern due to topographic structure, and the application of statistical models to describe relationships between topographic characteristics and vegetation pattern. To illustrate these methods, we draw on examples from our own analysis of landscape pattern dynamics in logged and unlogged forest landscapes in southwestern British Columbia. These examples also serve to illustrate the importance of considering topography in both research and management applications.This revised version was published online in May 2005 with corrections to the Cover Date.