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  • Author or Editor: Jorg M. Steiner x
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Abstract

Objective—To describe the kinetics of urinary recovery (UR) of 5 sugars used for gastrointestinal permeability and mucosal function testing following orogastric administration of lactose, rhamnose, xylose, methylglucose, and sucrose.

Animals—7 healthy male Beagles.

Procedure—A sugar solution containing lactulose, rhamnose, xylose, methylglucose, and sucrose was administered by orogastric intubation to healthy dogs. Urine samples were collected immediately before sugar solution administration (baseline) and at 2-hour intervals thereafter. The UR of the 5 sugars was determined from urine concentrations measured by high pressure liquid chromatography and pulsed amperometric detection. Percent urinary recovery (%UR) of the total UR up to 12 hours after sugar solution administration was calculated for each sugar at 2-hour intervals.

Results—Mean %UR exceeded 85% for all 5 sugars at 6 hours after orogastric administration of the sugar solution and exceeded 90% after 8 hours.

Conclusion and Clinical Relevance—In healthy dogs, a urine collection period of 6 hours is sufficient for gastrointestinal permeability and mucosal function testing following orogastric administration of lactulose, rhamnose, xylose, methylglucose, and sucrose. (Am J Vet Res 2002;63:845–848)

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in American Journal of Veterinary Research

Abstract

Objective—To develop and validate a radioimmunoassay (RIA) for measuring canine pancreatic lipase immunoreactivity (cPLI) in serum obtained from dogs.

Sample Population—Serum samples from 47 healthy dogs.

Procedures—Canine pancreatic lipase (cPL) was purified from pancreatic specimens of dogs. Antibodies against cPL were raised in rabbits and purified by use of affinity chromatography. A tracer was produced by iodination of cPL with 125I. An RIA was established and validated by determination of sensitivity, working range, dilutional parallelism, spiking recovery, and intra- and interassay variability. A reference range for cPLI in serum was established by use of the central 95th percentile for samples obtained from 47 healthy dogs.

Results—Sensitivity and upper limit of the working range were 0.88 and 863 µg/L, respectively. Observed-to-expected ratios for serial dilutions ranged from 84.9 to 116.5% for 4 samples. Observedto- expected ratios for spiking recovery ranged from 82.8 to 128.6% for 4 samples. Coefficients of variation for intra-assay variability for 4 serum samples were 18.3, 4.2, 3.5, and 8.9%, whereas interassay coefficients of variation were 29.2, 6.2, 3.9, and 4.4%, respectively. The reference range was 4.4 to 276.1 µg/L.

Conclusions and Clinical Relevance—We conclude that the RIA described is sensitive, linear, accurate, precise, and reproducible, with limited accuracy in the high end of the working range and limited precision and reproducibility in the low end of the working range. Additional studies are needed to evaluate whether this degree of accuracy, precision, and reproducibility will negatively impact clinical use of this assay. (Am J Vet Res 2003;64:1237–1241)

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in American Journal of Veterinary Research

Abstract

Objective—To validate an automated chemiluminescent immunoassay for measuring serum cobalamin concentration in cats, to establish and validate gas chromatography-mass spectrometry techniques for use in quantification of methylmalonic acid, homocysteine, cysteine, cystathionine, and methionine in sera from cats, and to investigate serum concentrations of methylmalonic acid, methionine, homocysteine, cystathionine, and cysteine as indicators of biochemical abnormalities accompanying severe cobalamin (vitamin B12) deficiency in cats.

Sample Population—Serum samples of 40 cats with severe cobalamin deficiency (serum cobalamin concentration < 100 ng/L) and 24 control cats with serum cobalamin concentration within the reference range.

Procedure—Serum concentrations of cobalamin were measured, using a commercial automated chemiluminescent immunoassay. Serum concentrations of methylmalonic acid, methionine, homocysteine, cystathionine, and cysteine were measured, using gas chromatography-mass spectrometry, selected ion monitoring, stable-isotope dilution assays.

Results—Cats with cobalamin deficiency had significant increases in mean serum concentrations of methylmalonic acid (9,607 nmol/L), compared with healthy cats (448 nmol/L). Affected cats also had substantial disturbances in amino acid metabolism, compared with healthy cats, with significantly increased serum concentrations of methionine (133.8 vs 101.1 µmol/L) and significantly decreased serum concentrations of cystathionine (449.6 vs 573.2 nmol/L) and cysteine (142.3 vs 163.9 µmol/L). There was not a significant difference in serum concentrations of homocysteine between the 2 groups.

Conclusions and Clinical Relevance—Cats with gastrointestinal tract disease may have abnormalities in amino acid metabolism consistent with cobalamin deficiency. Parenteral administration of cobalamin may be necessary to correct these biochemical abnormalities. (Am J Vet Res 2001;62:1852–1858)

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in American Journal of Veterinary Research

Abstract

Objective—To determine serum lipase activities and pancreatic lipase immunoreactivity (PLI) concentrations in dogs with exocrine pancreatic insufficiency (EPI).

Animals—74 healthy dogs and 25 dogs with EPI.

Procedures—A diagnosis of EPI was made on the basis of clinical signs, low serum trypsin like immunoreactivity (TLI) concentration, and response to treatment with enzyme replacement. Median values for fasting serum lipase activity and serum PLI concentrations were compared between the 2 groups with a Mann-Whitney U test.

Results—Median fasting serum lipase activity was not significantly different between dogs with EPI (366.0 U/L) and healthy dogs (294.5 U/L), and only 1 dog with EPI had a serum lipase activity less than the lower limit of the reference range. Median serum PLI concentration was significantly lower in dogs with EPI (0.1 μg/L) than in healthy dogs (16.3 μg/L). All dogs with EPI had serum PLI concentrations less than the lower limit of the reference range.

Conclusion and Clinical Relevance—Serum lipase activity is not limited to the exocrine pancreas in origin, whereas serum PLI is derived only from the exocrine pancreas. Unlike in serum TLI concentrations, there was a small degree of overlap in serum PLI concentrations between healthy dogs and dogs with EPI. Serum TLI concentration remains the test of choice for diagnosis of EPI.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To develop and validate an ELISA for quantitative analysis of feline trypsin-like immunoreactivity (fTLI).

Sample Population—Purified feline cationic trypsin (fCT) and rabbit anti-fCT antiserum; blood samples from 63 healthy cats.

Procedures—A sandwich capture ELISA was developed, using anti-fCT antiserum purified by affinity chromatography that underwent biotinylation. Purified fCT was used for standards. The assay was validated by determination of sensitivity, working range, linearity, accuracy, precision, and reproducibility. A reference range was established by assaying serum samples from the 63 healthy cats.

Results—Sensitivity was 1.23 µg/L; working range was 2 to 567 µg/L. Ratios of observed versus expected results for 4 samples tested at various dilutions ranged from 90.0 to 120.7%. Ratios of observed versus expected results for 5 samples spiked with various concentrations of fCT ranged from 82.0 to 101.8%. Intra- and inter-assay coefficients of variability ranged from 9.9 to 11.1% and from 10.2 to 21.7%, respectively. The reference range for serum fTLI measured with this ELISA was 12 to 82 µg/L.

Conclusions and Clinical Relevance—Results suggest that an ELISA can be used to measure serum fTLI in cats. The ELISA was sufficiently sensitive, linear, accurate, precise, and reproducible for clinical use. (Am J Vet Res 2000;61:620–623)

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in American Journal of Veterinary Research

Abstract

Objective—To develop and analytically validate a radioimmunoassay (RIA) for the quantification of canine calprotectin (cCP) in serum and fecal extracts of dogs.

Sample Population—Serum samples (n = 50) and fecal samples (30) were obtained from healthy dogs of various breeds and ages.

Procedures—A competitive, liquid-phase, double-antibody RIA was developed and analytically validated by assessing analytic sensitivity, working range, linearity, accuracy, precision, and reproducibility. Reference intervals for serum and fecal cCP concentrations were determined.

Results—Sensitivity and upper limit of the working range were 29 and 12,774 μg/L for serum and 2.9 and 1,277.4 μg/g for fecal extracts, respectively. Observed-to-expected ratios for serial dilutions of 6 serum samples and 6 fecal extracts ranged from 95.3% to 138.2% and from 80.9% to 118.1%, respectively. Observed-to-expected ratios for spiking recovery for 6 serum samples and 6 fecal extracts ranged from 84.6% to 121.5% and from 80.3% to 132.1%, respectively. Coefficients of variation for intra-assay and interassay variability were < 3.9% and < 8.7% for 6 serum samples and < 8.5% and < 12.6% for 6 fecal extracts, respectively. Reference intervals were 92 to 1,121 μg of cCP/L for serum and < 2.9 to 137.5 μg of cCP/g for fecal extracts.

Conclusions and Clinical Relevance—The RIA described here was analytically sensitive, linear, accurate, precise, and reproducible for the quantification of cCP in serum and fecal extracts. This assay should facilitate research into the clinical use of serum and fecal cCP measurements in dogs with inflammatory bowel disease.

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in American Journal of Veterinary Research

Abstract

Objective—To develop and validate a gas chromatography–mass spectrometry (GC-MS) method for determination of Nτ-methylhistamine (NMH) concentration in canine urine and fecal extracts and to assess urinary NMH concentrations in dogs with mast cell neoplasia and fecal NMH concentrations in dogs with protein-losing enteropathy.

Sample Population—Urine specimens were collected from 6 healthy dogs and 7 dogs with mast cell neoplasia. Fecal extracts were obtained from fecal specimens of 28 dogs with various severities of protein-losing enteropathy, as indicated by fecal concentration of α1-proteinase inhibitor.

Procedures—NMH was extracted directly from urine, and fecal specimens were first extracted into 5 volumes of PBSS containing 1% newborn calf serum. Nτ-methylhistamine in specimens was quantified via stable isotope dilution GC-MS. The assay was validated via determination of percentage recovery of known amounts of NMH and interassay coefficients of variation. Urinary excretion of NMH was evaluated by means of NMH-to-creatinine concentration ratios.

Results—Recovery of NMH in urine and fecal extracts averaged 104.6% and 104.5%, respectively. Interassay coefficients of variation ranged from 5.4% to 11.7% in urine and 12.6% to 18.1% in fecal extracts. Urinary NMH excretion was significantly increased in dogs with mast cell neoplasia, compared with that in healthy dogs. No correlation was detected between severity of protein-losing enteropathy and fecal NMH concentration.

Conclusions and Clinical Relevance—This method provided a sensitive, reproducible means of measuring NMH in canine urine and fecal extracts. High urinary NMH-to-creatinine concentration ratios in dogs with mast cell neoplasia are consistent with increased histamine release in this disease.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To test the hypothesis that intestinal pathologic changes are often concurrent with gastric pathologic changes in dogs and to characterize the historical, physical, clinicopathologic, imaging, and endoscopic findings in dogs with gastric histopathologic abnormalities.

Design—Retrospective case series.

Animals—67 dogs with gastric histopathologic abnormalities.

Procedures—Medical records from dogs that had undergone gastrotomy, gastroduodenoscopy, or gastroscopy between September 2002 and September 2007 were identified. Dogs were included in the study when histopathologic abnormalities were detected during evaluation of gastric tissue sections. History, clinical examination findings, results of diagnostic tests, diagnoses, treatments, and outcome were recorded for each dog.

Results—67 dogs with gastric histopathologic abnormalities were included in the study. The most frequent clinical sign recorded was vomiting (36/67 [53.7%] dogs). The most common biochemical abnormality recorded was panhypoproteinemia (27/64 [42.2%] dogs). Lymphoplasmacytic gastritis was the most frequent histopathologic finding recorded (34/67 [50.7%] dogs). For dogs in which both intestinal biopsy specimens and gastric biopsy specimens were collected, concurrent pathologic changes were recorded in 43 of 60 (71.7%) dogs.

Conclusions and Clinical Relevance—Results of this study suggested that intestinal pathologic changes are commonly concurrent in dogs with gastric pathologic changes. This supports the practice of collecting both gastric and duodenal biopsy specimens every time gastroduodenoscopy is performed. Lymphoplasmacytic gastritis was the most commonly recorded gastric histopathologic finding and was often of minimal or mild severity.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine cellular immunolocalization of canine gastric lipase (cGL) and canine pancreatic lipase (cPL) in various tissues obtained from clinically healthy dogs.

Sample Population—Samples of 38 tissues collected from 2 climically healthy dogs.

Procedures—The cGL and cPL were purified from gastric and pancreatic tissue, respectively, obtained from dogs. Antisera against both proteins were developed, using rabbits, and polyclonal antibodies were purified by use of affinity chromatography. Various tissues were collected from 2 healthy dogs. Primary antibodies were used to evaluate histologic specificity. Replicate sections from the collected tissues were immunolabeled for cGL and cPL and examined by use of light microscopy.

Results—Mucous neck cells and mucous pit cells of gastric glands had positive labeling for cGL, whereas other tissues did not immunoreact with cGL. Pancreatic acinar cells had positive labeling for cPL, whereas other tissues did not immunoreact with cPL.

Conclusions and Clinical Relevance—We concluded that cGL and cPL are exclusively expressed in gastric glands and pancreatic acinar cells, respectively. Also, evidence for cross-immunoreactivity with other lipases or related proteins expressed by other tissues was not found for either protein. Analysis of these data suggests that gastric lipase is a specific marker for gastric glands and that pancreatic lipase is a specific marker for pancreatic acinar cells. These markers may have clinical use in the diagnosis of gastric and exocrine pancreatic disorders, respectively. (Am J Vet Res 2002;63:722–727).

Full access
in American Journal of Veterinary Research