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Biomedical subjects

S A Center

Publications and source records attributed to S A Center.

65 records · Page 4Linked to original sources

Glomerular filtration rate and renal volume in dogs with congenital portosystemic vascular anomalies before and after surgical ligation.

Glomerular filtration rate (GFR) and renal volume were evaluated in dogs with confirmed portosystemic vascular anomalies (PSVA) before and after surgical ligation of their PSVA. Pre- and postligation CBC, serum biochemistry, urinalysis, abdominal ultrasonography with measurement of renal volume, and per rectal scintigraphy were performed to document resolution of abnormalities consistent with portosystemic shunting. GFR was estimated by plasma 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) clearance before (n = 21) and after (n = 12) surgical correction of PSVA. Preligation 99mTc-DTPA GFR was increased (median, 5.64 mL/minute/kg; range, 3.53-8.49 mL/minute/kg; reference range, 2.83-4.47 mL/minute/kg) in 81% (17/21) of dogs. Postligation 99mTc-DTPA GFR decreased in all 12 evaluated dogs (median change = -42%; P < .001). Preligation renal volume was above the reference range for the left and right kidneys in 71% (10/14) and 69% (11/16) of dogs evaluated, respectively. Right renal volume decreased significantly (n = 5; median change, -45%; P = .03) after surgical ligation of PSVA. These findings document increased GFR and renal volume in dogs with PSVA, which may explain in part the low blood urea nitrogen and serum creatinine concentrations encountered in these dogs. Knowledge of changes in GFR associated with PSVA ligation may prove helpful in the anesthetic, drug, and dietary management of affected dogs.

Animals↗

Prothrombin, activated partial thromboplastin, and proteins induced by vitamin K absence or antagonists clotting times in 20 hyperthyroid cats before and after methimazole treatment.

The effect of daily doses of 5-15 mg of methimazole on the platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and proteins induced by vitamin K absence or antagonists (PIVKA) clotting time in 20 hyperthyroid cats was determined. No significant (P > .05) difference was found in median platelet count. PT, APTT, or PIVKA clotting time before treatment compared to median values at 2-6 weeks or > or =7-12 weeks of methimazole treatment. No cat had a prolonged APTT at any time. At 2-6 weeks of methimazole treatment, 1 cat each developed thrombocytopenia or prolonged PIVKA clotting time despite initially normal values. Three cats had abnormal coagulation tests (prolonged PT [n = 1] and PIVKA clotting time [n = 3]) before treatment that fluctuated during treatment. Excluding the 3 cats that had abnormal PIVKA clotting time before treatment, prolonged PIVKA clotting time developed in 6% (1/17; 95% confidence interval, 0-28%) cats treated with methimazole for 2-6 weeks. Seemingly. doses of methimazole commonly used to treat hyperthyroidism in cats do not cause alteration in PT and APTT, and only rarely prolong PIVKA clotting time. Nevertheless, abnormal PIVKA clotting time may explain bleeding tendencies unassociated with thrombocytopenia in methimazole-treated hyperthyroid cats.

Animals↗

Proteins invoked by vitamin K absence and clotting times in clinically ill cats.

The clinical utility of the Thrombotest, a method for determining the prothrombin time that is uniquely sensitive to the presence of proteins invoked by vitamin K absence (PIVKA), was prospectively evaluated and compared to routine coagulation tests in cats with clinically suspected bleeding tendencies. Abnormal PIVKA clotting values were determined by comparison to results of a concurrently evaluated pooled feline plasma sample and by use of an absolute cutoff value of 25.2 seconds. To be recognized as abnormal, PIVKA clotting values had to be >20% of the pooled feline plasma PIVKA clotting time (the "20% rule") or > or =25.2 seconds (mean + 2 standard deviations of 150 different pooled feline plasma samples). Among the disorders in the population examined were 74 cats with liver disease and 19 cats with severe inflammatory bowel disease. Overall, a prolonged PIVKA clotting time based on the 25.2-second cutoff was found in 39.3% of cats, and based on the 20% rule in 40.7% of cats. An abnormal prothrombin time (PT) developed in 5.8% of cats, an abnormal APTT in 14% of cats, subnormal fibrinogen in 8.8% of cats, and thrombocytopenia in 3.3% of cats. Bleeding tendencies were confirmed in 22 cats, of which abnormal PIVKA clotting times were recognized in 95.5%, abnormal PT in 21%, abnormal activated partial thromboplastin time in 25%, hypofibrinogenemia in 16.7%, and thrombocytopenia in 4.5%. Response to treatment with vitamin K was demonstrated in 21 of 24 cats with an abnormal PIVKA clotting time. In these cats, an abnormal PIVKA clotting time normalized within 3 to 5 days of parenteral vitamin K administration. Cats responding to vitamin K administration had hepatic lipidosis (n = 7), severe inflammatory bowel disease (n = 4), severe inflammatory bowel disease associated with cholangiohepatitis (n = 5), and miscellaneous disorders (n = 5). Using either endpoint, the PIVKA clotting time is more sensitive for the detection of cats with coagulopathies than routinely used coagulation assessments in our hospital. Our findings confirm that cats with hepatic lipidosis, severe cholangiohepatitis, and severe inflammatory bowel disease develop coagulopathies responsive to vitamin K administration.

Animals↗

The clinical and metabolic effects of rapid weight loss in obese pet cats and the influence of supplemental oral L-carnitine.

The efficacy, safety, and metabolic consequences of rapid weight loss in privately owned obese cats by means of a canned weight-reduction diet and the influence of orally administered L-carnitine on rate of weight loss, routine clinical evaluations, hepatic ultrasonography, plasma amino acid profiles, and carnitine analytes were evaluated. A double-blinded placebo-controlled design was used with cats randomly divided into 2 groups: Group 1 (n = 14) received L-carnitine (250 mg PO q24h) in aqueous solution and group 2 (n = 10) received an identical-appearing water placebo. Median obesity (body condition scores and percentage ideal body weight) in each group was 25%. Caloric intake was restricted to 60% of maintenance energy requirements (60 kcal/kg) for targeted ideal weight. The reducing formula was readily accepted by all cats. Significant weight loss was achieved by week 18 in each group without adverse effects (group 1 = 23.7%, group 2 = 19.6%). Cats receiving carnitine lost weight at a significantly faster rate (P < .05). Significant increases in carnitine values developed in each group (P < .02). However, significantly higher concentrations of all carnitine moieties and a greater percentage of acetylcarnitine developed in cats of group 1 (P < .01). The dietary formula and described reducing strategy can safely achieve a 20% weight reduction within 18 weeks in obese cats. An aqueous solution of L-carnitine (250 mg PO q12h) was at least partially absorbed, was nontoxic, and significantly increased plasma carnitine analyte concentrations as well as rate of weight loss.

3-Hydroxybutyric Acid↗

Serum-effusion albumin gradient in dogs with transudative abdominal effusion.

A prospective clinical study in dogs with transudative abdominal effusions examined the clinical usefulness of the serum albumin-effusion albumin (SA-EA) gradient. In humans, the SA-EA gradient facilitates classification of abdominal effusion, with a gradient > or = 1.1 indicating the presence of portal hypertension. Gradient values proved useful for predicting therapeutic response to sodium restriction and diuresis in humans. Of 49 dogs evaluated, 25 had hepatobiliary disease (group 1) and 24 had other nonhepatobiliary conditions (group 2). Portal hypertension was clinically suspected in 24 of 25 dogs in group 1 and in 15 of 24 dogs in group 2. A broad range of SA-EA gradients was found. A gradient > or = 1.1 was found in 22 of 25 (88.0%) dogs with liver disease and in 14 of 24 (58.3%) dogs with other disorders. The median SA-EA gradient was higher in group 1 than in group 2, with values of 1.4 (range, 0.7-3.1) and 1.1 (range, 0.3-2.6), respectively (P < .04). Considerable overlapping of SA-EA gradients occurred between groups and among dogs with diverse conditions such that gradient values could not distinguish dogs with hepatobiliary disease from dogs with other conditions. The overall diagnostic accuracy of the SA-EA gradient in predicting portal hypertension in dogs with and without hepatobiliary disease (69.4%) exceeded that of hypoalbuminemia (57.1%). These findings suggest that portal hypertension is a predominant force in formation of transudative abdominal effusion in dogs with hepatobiliary disease and in dogs with other disorders. Whether the SA-EA gradient can be used to guide therapeutic mobilization of effusion in dogs remains to be proved.

Animals↗

Idiopathic hypercalcemia in cats.

Unexplained hypercalcemia has been increasingly recognized in cats since 1990. In some instances, hypercalcemia has been associated with calcium oxalate urolithiasis, and some affected cats have been fed acidifying diets. We studied the laboratory findings, clinical course, and treatment of 20 cats with idiopathic hypercalcemia. Eight (40%) of the cats were longhaired and all 14 cats for which adequate dietary history was available had been fed acidifying diets. Clinical signs included vomiting (6 cats), weight loss (4 cats), dysuria (4 cats), anorexia (3 cats), and inappropriate urinations (3 cats). Hypercalcemia was mild to moderate in severity. and serum parathyroid hormone concentrations were normal or low. Serum concentrations of phosphorus, parathyroid hormone-related peptide, 25-hydroxycholecalciferol, and calcitriol were within the reference range in most cats. Diseases commonly associated with hypercalcemia (eg, neoplasia, primary hyperparathyroidism) were not identified despite thorough medical evaluations and long-term clinical follow-up. Azotemia either did not develop (10 cats) or developed after the onset of hypercalcemia (3 cats), suggesting that renal failure was not the cause of hypercalcemia in affected cats. Seven of 20 cats (35%) had urolithiasis, and in 2 cats uroliths were composed of calcium oxalate. Subtotal parathyroidectomy in 2 cats and dietary modification in 11 cats did not result in resolution of hypercalcemia. Treatment with prednisone resulted in complete resolution of hypercalcemia in 4 cats.

Animal Feed↗

The effects of S-adenosylmethionine on clinical pathology and redox potential in the red blood cell, liver, and bile of clinically normal cats.

S-adenosylmethionine (SAMe), an important hepatic metabolite and glutathione (GSH) donor, has been studied mechanistically in vitro, in humans with clinical liver disease, and in experimental animal models of liver disease. Collective findings encourage its therapeutic use in necroinflammatory and cholestatic liver disorders. A chronic longitudinal study (pre- and posttreatment parameters compared) was undertaken with 15 clinically healthy cats given a stable 1,4-butanedisulfonate (S'S isomer) SAMe salt (enteric coated tablets providing 180 mg SAMe), dosage 48 mg/kg PO q24h, on an empty stomach for 113 days. Routine physical and clinicopathologic assessments, red blood cell (RBC) osmotic fragility, liver function and histology, hepatic concentrations of reduced GSH (RGSH) and its oxidized disulfide form (GSSG), protein, glycogen, and deoxyribonucleic acid, GSH concentrations in RBCs, total bile acids in serum and bile, oxidative membrane products (TBARS) in RBCs and liver, and plasma SAMe concentrations were evaluated. SAMe administered PO significantly increased plasma SAMe concentrations, and peak concentrations usually occurred 2-4 hours after dosing. Chronic SAMe administration did not change peak or cumulative plasma SAMe concentrations and did not [corrected] cause overt signs of toxicity. A positive influence on RBC and hepatic redox status (RBC TBARS reduced 21.1% [P < .002], liver GSH increased 35% [P < .002], liver RGSH: GSSG ratio increased 69% [P < .03]) and improved RBC resilience to osmotic challenge (P < .03) were observed. Results prove that this SAMe PO product is enterically available and suggest that it imparts biologic effects that might be useful for attenuating systemic or hepatic oxidant challenge.

Animals↗

Association of Helicobacter with cholangiohepatitis in cats.

Infection with Helicobacter spp. is increasingly linked with hepatobiliary inflammation and neoplasia in people and in a variety of animals. We sought to determine if Helicobacter species infection is associated with cholangiohepatitis in cats. Deoxyribonucleic acid was extracted from tissue blocks from cats with cholangiohepatitis (32), noninflammatory liver disease (13), and cats with normal liver histology (4). Deoxyribonucleic acid was polymerase chain reaction-amplified with 2 sets of Helicobacter genus-specific primers, gel purified, and sequenced. Polymerase chain reaction-positive hepatic tissue was further examined with Steiner's stain, immunocytochemistry for Helicobacter species, and eubacterial fluorescent in situ hybridization. Gastric tissues of cats with known Helicobacter infection status served as controls for deoxyribonucleic acid extraction and sequence comparison. Helicobacter species were detected in 2/32 cats with cholangiohepatitis, and 1/17 controls. Sequences had 100% identity with Helicobacter species liver, Helicobacter pylori, and Helicobacter fenelliae/cinaedii in a cat with suppurative cholangitis, Helicobacter species liver, Helicobacter pylori, and Helicobacter nemistrineae in a cat with mild lymphocytic portal hepatitis, and Helicobacter bilis in a cat with portosystemic vascular anomaly. In contrast, sequences from gastric biopsies showed highest homology (99-100%) to "Helicobacter heilmannii," Helicobacter bizzozeronii, Helicobacter felis, and Helicobacter salomonis. Fluorescent in situ hybridization revealed a semicurved bacterium, with Helicobacter-like morphology, in an intrahepatic bile duct of the cat with suppurative cholangitis. This study has identified Helicobacter deoxyribonucleic acid in 2/32 cats with cholangiohepatitis and 1/13 cats with noninflammatory liver disease. Deoxyribonucleic acid sequences of hepatic Helicobacter species were distinct from those found in the stomach and are broadly consistent with those identified in cat intestine and bile, and hepatobiliary disease in people and rodents.

Animals↗

Successful treatment of feline pancreatitis using an endoscopically placed gastrojejunostomy tube.

A cat with pancreatitis, diagnosed using abdominal ultrasonography, fine-needle aspirate cytopathology, and increased concentration of serum trypsin-like immunoreactive substance, was treated successfully using jejunal alimentation provided through a percutaneous gastrojejunostomy tube. This method of jejunal feeding is less technically difficult, less stressful for the patient, and has fewer complications than surgically placed jejunostomy tubes. Nutritional support with jejunal feeding is superior to total parenteral nutrition, as it maintains gut integrity, decreases septic complications, and may reduce exogenous insulin requirements. The methods of tube insertion and maintenance, and the physiological advantages over other feeding methods are described.

Animals↗