A pilot study on the effect of fat loading on the gastrointestinal tract of healthy dogs.

OBJECTIVE: To assess the effect of a high fat meal (fat loading) on gastrointestinal motility and the appearance of intestinal villi using video capsule endoscopy and ultrasound. MATERIALS AND METHODS: Four healthy staff-owned dogs were included in a prospective blinded crossover study. Dogs had initial baseline video capsule endoscopy to measure gastrointestinal transit times and allow for visual assessment of intestinal mucosa. Abdominal ultrasound was also performed to obtain intestinal wall measurements and assess for the presence of mucosal hyperechoic speckling. All dogs had diagnostics repeated twice between one and two hours after ingestion of either corn oil or dairy cream for a total of four control and 16 fat loaded studies. RESULTS: Dogs in the corn oil group had greater mean gastric emptying times (740.3 ± 187.6 minutes vs. 237.9 ± 155 minutes) and total transit times (54.50 ± 22.2 hours vs. 23.25 ± 6.1 hours) than controls. Feeding of a fatty meal resulted in substantial retention of the capsules (10 of 16) within the stomach. While intestinal wall thickness of fat loaded dogs did not differ from control dogs, mucosal hyperechoic speckling scores of the duodenum of dairy cream dogs were greater when compared to control dogs (1.625 ± 0.518 vs. 0.500 ± 0.577). CLINICAL SIGNIFICANCE: Data from this pilot study provides further evidence that feeding of a small high fat meal results in ultrasonographic as well as visual changes to the intestinal mucosa of healthy dogs. This data suggests that previous recommendations to feed fatty meals to dogs with lymphangiectasia might not allow differentiation with healthy individuals. In addition, due to the marked effect on gastric emptying time, video capsule endoscopy should be avoided in dogs fed a high fat meal.

Splenosystemic shunts in cats: a retrospective of 33 cases (2004-2011).

BACKGROUND: Portosystemic shunts are uncommonly reported in cats. The majority of reports describe congenital shunts in young cats originating from the left gastric vein. Although they are only rarely reported, acquired portosystemic shunts in cats appear to be more variable in their anatomic location. HYPOTHESIS/OBJECTIVE: To describe the signalment and disease conditions found in cats with splenosystemic shunts. ANIMALS: Thirty-three client-owned cats with documented splenosystemic shunts. MATERIALS AND METHODS: Retrospective study. All cats with vascular communications between the splenic and left renal veins or the splenic vein and caudal vena cava diagnosed ultrasonographically between 2004 and 2011 were included. Collected data included age, breed, sex, presenting complaints, clinicopathologic data, as well as clinical diagnosis when available. RESULTS: Splenosystemic shunts were identified in 1.3% of the cats that had an abdominal ultrasound performed during the study period. Older, spayed female cats were found to be significantly overrepresented when compared with the total population of cats having undergone ultrasound over the same time period. A large proportion of cats (42%) had a hepatopathy with the potential for associated portal hypertension. CONCLUSIONS AND CLINICAL IMPORTANCE: Neither the signalment of cats in this report nor the anatomy of their portovascular anomalies shared similarities with those cats previously identified with single-vessel shunts. The relevance and etiology of these newly described splenosystemic shunts remain elusive and warrantsfurther investigation.

Coexpression of rat glutathione S-transferase A3 and human cytidine deaminase by a bicistronic retroviral vector confers in vitro resistance to nitrogen mustards and cytosine arabinoside in murine fibroblasts.

The transfer of drug resistance genes into hematopoietic cells is an experimental approach to protect patients from drug-induced myelosuppression. Because anti-cancer drugs are often administered in combination to increase their clinical efficacy, vectors that express two drug resistance genes are being developed to broaden the spectrum of chemoprotection. We have constructed a bicistronic vector, MFG/GST-IRES-CD (MFG/GIC) coexpressing rat glutathione S-transferase (GST) A3 isoform (rGST Yc1) and human cytidine deaminase (CD). Murine NIH 3T3 fibroblast cells transduced with this vector were evaluated for their resistance to nitrogen mustards and cytosine nucleoside analogs. GIC-transduced polyclonal cell populations (GIC cells) demonstrated marked increases in selenium-independent glutathione peroxidase (peroxidase) and CD activities, as well as increased resistance to melphalan (2.3-fold), chlorambucil (3.4-fold), and cytosine arabinoside (Ara-C) (8.1-fold). After selection with Ara-C, the peroxidase and CD activities of GIC cells were augmented 2.6- and 2.9-fold, respectively, in comparison with unselected cells, and the resistance to melphalan, chlorambucil, and Ara-C was further increased to 3.7-, 5.9-, and 53-fold, respectively. Melphalan selection of GIC cells likewise augmented their peroxidase (2.3-fold) and CD (1.9-fold) activities. GIC cells proliferated in the simultaneous presence of melphalan and Ara-C at drug concentrations that completely inhibited the growth of untransduced cells. The growth rate of unselected GIC cells exposed to the drug combination averaged 18% that of drug-free cultures. The growth rate of GIC cells exposed to the drug combination increased to 30% of controls after Ara-C selection and to 50% after melphalan selection. Our results suggest that retroviral transfer of MFG/GIC may be useful for chemoprotection against the toxicities of nitrogen mustards and cytosine nucleoside analogs.