2003 ACVIM Abstracts surement of inert sugar probes in urine has recently been developed and validated. Clinical experience with gastrointestinal permeability and mucosal function testing for the assessment of dogs with suspected gastrointestinal disease prompted exploration of the use of serum rather than urine as a sample medium. Serum sample preparation and assay for the measurement of inert sugars has previously been reported, but the procedure described used ethyl ether, which was not deemed safe for routine use. Therefore, the aim of this study was the development and validation of a new protocol for isolation of inert sugar probes from serum samples and subsequent quantification by high-performance liquid chromatography (HPLC) and pulsed amperometric detection (PAD). Pooled canine serum samples were spiked with 3-O-methylglucose, L-rhamnose, D-xylose, sucrose, lactulose, and L-fucose, the latter serving as an internal standard. Contaminants were reduced by protein precipitation with acetonitrile, followed by solid phase extraction. The amount of endogenous glucose present in the samples was reduced by incubation with glucose oxidase and catalase. Sugar probes were quantified by HPLC and PAD. The protocol was validated by determination of dilutional parallelism, spiking recovery, intra-assay variability, and interassay variability. Observed to expected (O/E) ratios for serial dilutions of 3 spiked serum samples ranged from 78.4 to 134.4% (mean ⫾ SD 101.2 ⫾ 12.3%) for dilutions of 1 in 2, 1 in 4, and 1 in 8. O/E ratios for 3 serum samples spiked with 5 different sugar concentrations ranged from 86.8 to 117.2% (mean ⫾ SD 100.1 ⫾ 5.9%) for spiked concentrations of 50, 25, 12.5, 6.25, and 3.25 mg/L. Intra-assay coefficients of variation for 3 spiked serum samples were 2.2, 3.8, and 1.0% for methylglucose, 3.9, 3.3, and 1.7% for rhamnose, 3.6, 3.4, and 3.2% for xylose, 3.9, 2.9, and 2.5% for sucrose, and 4.7, 3.3, and 1.7% for lactulose. Interassay coefficients of variation for 3 spiked serum samples were 4.0, 6.3, and 9.7% for methylglucose, 3.2, 6.9, and 8.8% for rhamnose, 4.0, 5.5, and 6.2% for xylose, 6.8, 5.8, and 6.8% for sucrose, and 6.5, 8.6, and 5.3% for lactulose. These results indicate that the sample preparation and assay procedure described here is linear, accurate, precise, and reproducible. Further studies evaluating the kinetics of these sugar probes in serum after oral administration to clinically healthy dogs are currently in progress.
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USE OF BUTTER TO FACILITATE THE PASSAGE OF TABLETS THROUGH THE ESOPHAGUS IN CATS. B Griffin, DM Beard, KA Klopfenstein, Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, AL.
Esophageal retention of dry tablets has been demonstrated to occur commonly in cats and may be associated with esophagitis and subsequent stricture formation. A small oral bolus of water (6 mL) administered to cats following tablet administration has been shown to significantly hasten passage into the stomach. The purpose of this study was to determine (1) if tablets coated with a smear of butter pass readily through the feline esophagus and (2) if use of a standard pet pill gun hastens passage of dry tablets. Eight healthy DSH laboratory cats ranging in age from 3–5 years were used for this study. Calcium carbonate tablets (750 mg Tums威, SmithKline Beecham, Pittsburgh, PA) were quartered and administered by hand with and without 1st being coated with a smear of butter. Cats were immediately placed in a Plexiglas box and a C-arm fluoroscope was used to horizontally image the oral pharynx, esophagus and stomach continuously for 1.5 minutes, then at 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 minutes posttablet administration. The cats were not restrained in the box and were allowed to sit, stand or turn within the box during imaging. The following day, dry tablets were administered using a pill gun and the imaging was repeated. For the dry tablets administered by hand, time from administration until passage into the stomach ranged from 24 seconds to ⬎11 minutes. Of these, 3/8 cats passed the tablet in ⬍1 minute, 1/8 cats at 9.5 minutes, and 4/8 cats at ⬎11 minutes. For all 4 cats retaining the tablet in the esophagus after 11 minutes, butter was smeared on the nose, and the tablet passed into the stomach within 1 minute of licking the butter. For the butter-coated tablets, time from administration until passage into the stomach ranged from 24–59 seconds (mean 37 seconds). For the dry tablets administered using a pill gun, time from administration until passage into the stomach ranged from 39 seconds to ⬎11 minutes. Of these, 3/8 passed the tablet in ⬍1 minute (the same 3 cats that swallowed the dry tablet administered by hand in ⬍1 minute), 1/8 cats at 2.5 minutes, 1/8 cats at 4.5 minutes, and 3/8 cats at ⬎11 minutes. This time, for the cats retaining the tablet in the esophagus after 11 minutes (n ⫽ 3), Nutrical威 (EVSCO Pharmaceuticals, Buena, NJ) was smeared on the nose, and the tablet passed into the stomach within 1 minute of licking the Nutrical威. Transit time to the stomach did not significantly differ (p ⬎ .05) between hand or pill gun administration of dry tablets. Transit time to the stomach was significantly less (p ⬍ .05) with butter-coated tablets compared to dry tablets. Placing butter or Nutrical威 on the nose following dry tablet administration stimulated licking and significantly decreased transit time to the stomach (p ⬍ .05). These results illustrate practical recommendations to facilitate swallowing of tablets in cats.
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445 INTRAINDIVIDUAL VARIABILITY OF FECAL ␣1-PROTEINASE INHIBITOR CONCENTRATION IN CLINICALLY HEALTHY DOGS. JM Steiner1, CG Ruaux1, MD Miller1, ZM Wright1, SR Teague1, S Vaden2, and DA Williams1. 1GI Lab, Texas A&M University, College Station, TX, 2North Carolina State University, Raleigh.
Canine fecal ␣1-proteinase inhibitor concentration (cF␣1-PI) has been shown to be a useful indicator of gastrointestinal protein loss in dogs and to be increased in Soft-Coated Wheaten Terriers with idiopathic protein-losing enteropathy (PLE) prior to development of clinical signs. Significant changes of cF␣1-PI over short periods have been described and 3 samples of freshly produced feces from 3 consecutive days are currently collected. However, intraindividual variability over longer periods has never been evaluated. Seventeen clinically healthy pet dogs were enrolled into the study. Gastrointestinal health was not assessed in any of the dogs and subclinical gastrointestinal disease could have been present in at least some of the dogs. Three samples were collected from freshly voided feces on 3 consecutive days starting on days 0, 14, and 28. Fecal ␣1-PI was measured by an in-house ELISA (reference range 0.23–5.67 g/g wet weight of feces). Canine F␣1-PI results were compared by 2-way ANOVA. Intraindividual variability for each dog was assessed by calculation of the coefficients of variation of the mean from each study period and the highest cF␣1-PI observed in each of the 3 study periods. Mean ⫾ SD cF␣1-PI for the 17 dogs and all 3 study periods was 2.88 ⫾ 4.48 g/g feces. There were a total of 11 dogs that had an increased cF␣1-PI during at least 1 of the study periods. Three dogs had a moderately increased cF␣1-PI, defined as ⬎12 g/g but ⬍20 g/g, but these dogs had only 1 moderately increased cF␣1-PI in a single sample of 1 study period each. One dog had a severely increased cF␣1-PI, defined as ⬎20 g/g. This dog had 3 severely increased cF␣1-PIs during the same sampling period but had normal cF␣1-PIs for all other samples and sampling periods. Mean ⫾ SD of coefficients of variation for the mean and highest cF␣1-PI for the 3 sampling periods in the 17 dogs were 65.4 ⫾ 35.1% (range 19.7 to 136.4%) for the mean and 75.0 ⫾ 32.3% (range 18.2 to 123.1%) for the maximum cF␣1-PI. Two-way ANOVA showed that 3.4% of the total variance was due to sampling time, 30.3% due to intradog variation between sampling time, and 41.9% was due to dog/sampling time interaction. Several of the dogs examined had single samples with mildly to moderately increased cF␣1-PIs. Some of these dogs may have had subclinical gastrointestinal disease, but this finding may also suggest that single episodes of increased gastrointestinal protein loss may be seen in healthy dogs. We conclude that cF␣1PI concentration shows a high intraindividual variability, necessitating evaluation of the mean as well as the maximum cF␣1-PI of the 3-day sample collection in order to avoid over-interpretation of results. The intraindividual variability in dogs with an elevated cF␣1-PI due to inflammatory or idiopathic PLE may not be as high and remains to be determined.
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INCREASES IN SERUM PANCREATIC LIPASE IMMUNOREACTIVITY (PLI) ARE GREATER AND OF LONGER DURATION THAN THOSE OF TRYPSIN-LIKE IMMUNOREACTIVITY (TLI) IN CATS WITH EXPERIMENTAL PANCREATITIS. DA Williams1, JM Steiner1, CG Ruaux1, and N. Zavros2. 1Gastrointestinal Laboratory, Texas A&M University, College Station, TX; 2 Aristotle University of Thessaloniki, Greece.
Pancreatitis is common in cats but difficult to diagnose. We have developed assays for 2 pancreas-specific markers, trypsin-like immunoreactivity (fTLI) and pancreatic lipase immunoreactivity (fPLI), that would be expected to be of value in diagnosing feline pancreatitis. The aim of this study was to document observations on changes in serum concentrations of these 2 parameters in samples from cats with transient experimentally induced acute pancreatitis. Blood samples were collected at 0, 8, and 24 hours, and 2, 3, 4, 5, 6, 8, 10, 12, 16 and 20 days from 6 cats in which transient acute pancreatitis had been induced by retrograde injection of oleic acid into the pancreatic duct as part of another research project. Serum was collected and stored at ⫺20⬚C until shipped frozen from the Aristotle University of Thessaloniki to the Gastrointestinal Laboratory at Texas A&M University for assay of fTLI and fPLI by ELISA and radioimmunoassay, respectively. Serum fTLI and fPLI concentrations were within the control ranges prior to induction of pancreatitis in all cats, but had increased above the upper limit of the control range by 8 hours after induction of pancreatitis. Both analytes peaked at 24 hours, fTLI reaching a mean of 35⫻ baseline concentrations and fPLI reaching a mean of more than 50⫻ baseline concentrations. Mean serum fTLI concentration returned to within the control range by day 3, whereas mean serum fPLI was increased until day 10. Both serum fTLI and fPLI concentrations increased transiently during the course of pancreatitis in this experimental model. However, the magnitude and duration of the proportional increase of fPLI was greater than that of fTLI. These observations may be explained by a greater serum half life of feline classical pancreatic lipase compared to that of feline cationic trypsinogen, which may reflect the greater molecular weight of feline classical pancreatic lipase