Biomedical subjects

D L Zoran

Publications and source records attributed to D L Zoran.

9 recordsLinked to original sources

PubMed2001

Hyperactivity and alopecia associated with ingestion of valproic acid in a cat.

A 1-year-old castrated male cat was evaluated because of alopecia of approximately 4 to 5 months' duration as well as hyperactive behavior. It was later determined that the cat was ingesting valproic acid by eating food to which it had been added for daily administration to a child in the household who had cerebral palsy. The clinical signs slowly resolved after the source of valproic acid was removed. This emphasizes the sensitivity of cats to drugs that are commonly used in humans. It was not determined whether the clinical signs that developed in this cat were caused by an adverse reaction or from toxicosis as a result of prolonged hepatic elimination of valproic acid, which requires glucuronide metabolism for disposition. However, the cat recovered completely following removal of the drug and prevention of further exposure. This report emphasizes the importance of obtaining a careful and complete history from the owner regarding an animal and its environment. In the cat of this report, the owner had not considered the impact of the presence of the drug in the child's food.

Alopecia↗

PubMed2001

Gastroduodenoscopy in the dog and cat.

Endoscopic examination of the upper gastrointestinal (GI) tract in dogs and cats is a relatively recent development. It was just over 20 years ago, in 1978, that the first series report of GI endoscopy in dogs and cats was presented. In those initial days, endoscopy was truly a novelty, and the primary uses for endoscopes were to retrieve foreign objects or visualize the esophagus and stomach. It was not until the mid-1980s that technology and training made gastroduodenoscopy standard practice. The evolution in endoscopic technology has also mirrored the evolution in computers and imaging modalities. The original fiberoptic endoscopes, although still available, are giving way to video endoscopy and digital imaging capabilities that provide spectacular images and an ability to generate hard copy images for medical records, teaching purposes, and research data that was previously not possible.

Animals↗

PubMed1998

Dietary fiber differentially alters cellular fatty acid-binding protein expression in exfoliated colonocytes during tumor development.

We investigated the utility of noninvasive technology utilizing feces containing exfoliated colonocytes to determine whether changes in fecal fatty acid-binding proteins have predictive value in monitoring the neoplastic process. Ninety male Sprague-Dawley rats were randomly divided into four groups in a 2 x 2 factorial design, with two dietary fiber sources (wheat bran or oat bran) and two treatment groups (injection with a carcinogen, azoxymethane, or saline). Fresh fecal samples were collected at Week 16 postinjection, and tumor frequency was determined at Week 36 of the study. Semiquantitative "mimic" reverse transcriptase polymerase chain reaction was used to quantitate the expression of liver fatty acid-binding protein (L-FABP), intestinal fatty acid-binding protein (i-FABP), and acyl CoA-binding protein (ACBP) mRNA in fecal samples to establish their prognostic value. Rats fed wheat bran diets had a lower incidence of tumors (p < 0.05). There was no effect of carcinogen injection or tumor incidence on the expression of L-FABP, i-FABP, or ACBP mRNA, L-FABP and i-FABP mRNA expression were significantly higher (p < 0.05) in feces from animals fed a wheat bran diet than in feces from animals fed an oat bran diet. In contrast, the expression of ACBP mRNA was significantly lower (p < 0.05) in animals fed a wheat bran diet than in animals fed an oat bran diet. Wheat bran also increased (p < 0.05) the total excretion of L-FABP, i-FABP, and ACBP over a 48-hour period. These data suggest that exfoliated colonocyte fatty acid-binding protein mRNA status may provide insight into the mechanisms by which diet influences colonic physiology.

Animals↗

PubMed1997

Diet and carcinogen alter luminal butyrate concentration and intracellular pH in isolated rat colonocytes.

A 2 x 2 factorial experiment was conducted to examine the effects of two different dietary fibers and carcinogen treatment on colonic luminal short-chain fatty acid (SCFA) concentrations and intracellular pH (pHi) in rats. Twenty-four male Sprague-Dawley rats were divided into four groups, injected with a carcinogen [azoxymethane (AOM)] or normal saline (Sal), and fed one of two diets differing only in the type of dietary fiber [cellulose (Cell) or pectin (Pect)]. After 38 weeks of consuming these diets, the rats were euthanized, luminal contents were collected for analysis of SCFA concentrations, and colonocytes were isolated from the proximal and distal colon for subsequent determination of pHi. Changes in pHi after the addition of exogenous sodium butyrate to the culture medium were also tested. The highest concentrations of SCFAs were produced by the control rats (saline injected) consuming the pectin diet. Luminal butyrate concentrations were reduced in three of four colonic segments of carcinogen-injected groups [proximal and distal cellulose (Prox Cell and Dist Cell) and distal pectin (Dist Pect)] compared with saline controls. The pHi was consistently higher in colonocytes isolated from carcinogen-injected rats (Prox Cell/AOM = 6.95 vs. Prox Cell/Sal = 6.65, Prox Pect/AOM = 6.75 vs. Prox Pect/Sal = 6.65, Dist Cell/AOM = 6.94 vs. Dist Cell/AOM = 6.85, Dist Pect/AOM = 6.92 vs. Dist Pect/Sal = 6.79) than in cells from saline-injected rats. Furthermore, in the majority of rats, pHi was lower in the proximal than in the distal colon. Addition of butyrate to cultured colonocytes consistently lowered pHi, but the effect was more pronounced in the carcinogen-injected animals. These data identify changes that occur intraluminally and intracellularly in colons of rats injected with AOM and suggest that, during tumorigenesis, alterations in butyrate production and basic colonocyte physiology may play an important role in the process.

Animals↗

PubMed1997

Wheat bran diet reduces tumor incidence in a rat model of colon cancer independent of effects on distal luminal butyrate concentrations.

To investigate the effects of dietary fibers in colonic luminal physiology and their role in the prevention of colon cancer, a study was conducted using two diet groups and two treatment groups in a 2 x 2 factorial design. The two diets differed only in the type of dietary fiber, wheat bran and oat bran, and the two treatments were injection with the colon-specific carcinogen azoxymethane, or saline, as a control. There were 34 rats in the carcinogen-injected groups and 11 saline-injected rats per diet group. The goal of the study was to determine if a moderate consumption (6 g/100 g diet) of wheat bran or oat bran would alter the development of colonic tumors in this rat model of colon cancer, and if the differences in tumor incidence were correlated to luminal butyrate concentrations, luminal pH or fecal bulk. Short-chain fatty acid concentrations (SCFA) were measured in feces during the first half of the study (the promotion phase of tumor development) and again at the end of the study. Rats consuming oat bran had greater body weights (P < 0. 002), produced much larger concentrations of all SCFA, including butyrate, in both the proximal and distal colon (P < 0.0001), had more acidic luminal pH values (P < 0.0001), but also had significantly more development of colon tumors (P < 0.03). Alternatively, rats consuming wheat bran produced more typical molar ratios of the SCFA (65:10:20), had a relatively greater concentration of butyrate than propionate, and produced a larger volume (P < 0.05) and more bulky stool than the rats fed oat bran. The results of this study support other evidence that an acidic luminal pH is not protective in and of itself, and that diets containing wheat bran are protective against colon cancer development. In addition, these data show that large luminal butyrate concentrations in the distal colon alone, as were present in the rats consuming oat bran diets, are not protective of tumor development.

Animals↗

PubMed1995

Diet and exercise patterns in pet dogs.

A study was conducted to provide baseline data on pet dog diet and exercise patterns. In addition, the repeatability of a telephone questionnaire to determine these patterns was evaluated. Dogs seen at the Texas Veterinary Medical Center that were less than 3 years old and of medium, large, or giant purebreeds or mixed-breeds were included. Information was collected about background variables, brands, quantities, and types of foods fed, and types and frequency of exercise. Daily intake of metabolizable energy, calcium, fat, and protein were calculated from the diet. Sixty-nine dog owners completed the study. Most dogs were kept as pets in an urban/suburban environment. Most were also fed dry food. About 60% were fed dog biscuits or some other dog snack or treat, and about half of the dogs in the study were fed twice daily. Meat scraps and bones were the table foods most commonly fed. Most owners considered their dogs to be moderately or very active. Greater than 70% of the dogs were confined to a fenced yard. About 65% of the owners took their dogs for walks. Forty percent of dogs in the study exercised with other dogs daily. More than half of the owners reported playing retrieving games with their dogs, including playing with a flying disk. The questionnaire was shown to be repeatable.

Animal Feed↗

PubMed1993

Pharmacokinetics of propofol in mixed-breed dogs and greyhounds.

Pharmacokinetics and recovery characteristics of propofol in Greyhounds and mixed-breed dogs were compared. In all dogs, disposition of propofol was adequately described by a 2-compartment open model, with a rapid distribution phase followed by a slower elimination phase. When findings in Greyhounds were compared with those in mixed-breed dogs, significant differences were observed in mean concentrations of propofol in blood, recovery characteristics, and estimates for apparent volume of distribution, volume of distribution at steady state, and total body clearance. In addition, Greyhounds recovered from anesthesia at higher concentrations of propofol than did mixed-breed dogs. A secondary peak in blood propofol concentration was observed in 8 of 10 Greyhounds and in 5 of 8 mixed-breed dogs. This peak corresponded to the time of return of the righting reflex.

Animals↗

PubMed1992

Evaluation of hemostatic analytes after use of hypertonic saline solution combined with colloids for resuscitation of dogs with hypovolemia.

The effects of hypertonic saline solution (HTSS) combined with colloids on hemostatic analytes were studied in 15 dogs. The analytes evaluated included platelet counts, one-stage prothrombin time, activated partial thromboplastin time, von Willebrand's factor antigen (vWf:Ag), and buccal mucosa bleeding times. The dogs were anesthetized, and jugular phlebotomy was used to induced hypovolemia (mean arterial blood pressure = 50 mm of Hg). Treatment dogs (n = 12) were resuscitated by infusion (6 ml/kg of body weight) of 1 of 3 solutions: HTSS combined with 6% dextran 70, 6% hetastarch, or 10% pentastarch. The control dogs (n = 3) were autotransfused. Hemostatic analytes were evaluated prior to induction of hypovolemia (baseline) and then after resuscitation (after 30 minutes of sustained hypovolemia) at 0.25, 0.5, 1, 6 and 24 hours. All treatment dogs responded rapidly and dramatically to resuscitation with hypertonic solutions. Clinically apparent hemostatic defects (epistaxis, petechiae, hematoma) were not observed in any dog. All coagulation variables evaluated, with the exception of vWf:Ag, remained within reference ranges over the 24-hour period. The vWf:Ag values were not statistically different than values from control dogs, and actual values were only slightly lower than reference ranges. Significant (P < or = 0.04) differences were detected for one-stage prothrombin time, but did not exceed reference ranges. The results of this study suggested that small volume HTSS/colloid solutions do not cause significant alterations in hemostatic analytes and should be considered for initial treatment of hypovolemic or hemorrhagic shock.

Animals↗

PubMedDate not supplied

Elevated parathyroid hormone-related protein and hypercalcemia in two dogs with schistosomiasis.

Two adult dogs were evaluated for hypercalcemia. Diagnostic evaluation identified elevated parathyroid hormone-related protein (PTHrP) and presumptive humoral hypercalcemia of malignancy. At necropsy, schistosomiasis was diagnosed. North American schistosomiasis is caused by Heterobilharzia americana. Clinical findings may include dermatitis, coughing, diarrhea, and anorexia. Clinicopathological findings may include hypercalcemia, hyperglobulinemia, hypoalbuminemia, anemia, and eosinophilia. Diagnosis by fecal examination is difficult. Praziquantel or fenbendazole treatment may be curative or palliative. These are the first reported cases of hypercalcemia with elevated PTHrP in animals without diagnosed malignancy. Elevation of PTHrP has not been previously reported in hypercalcemic humans or in animals with granulomatous inflammation.

Animals↗