Effect of antigen challenge on sensitized guinea pig trachea

Leiomyosarcomas of the small intestine were found in dogs during experimental induction of gastric carcinoma by oral administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Leiomyosarcomas were found most frequenly in the duodenum and jejunum, and occasionally in the stomach but never in the ileum, colon, or rectum. The leiomyosarcomas developed in all the dogs given 50 mug/ml of MNNG in deionized water to drink but not in dogs fed on porridge food made from standard pellet diet mashed with MNNG at the same concentration in tap water. Intestinal sarcomas developed in 3 months to 5 years after the end of MNNG administration, and frequently metastasized to the liver and/or the peritoneum.     

Experimental gastric cancer (author's transl)

Methods have been established to produce gastric cancer in rats and dogs by administration of N-methyl-N'-nitro-N-nitrosoguanidine or of the ethyl derivate. The agent is administered in drinking water or by a pellet diet soaked in the carcinogen. Histologically well differentiated and poorly differentiated types of adenocarcinoma and signet-ring cell tumors are induced in several months with greath reliability. Metastases were observed in both rats and dogs with gastric carcinoma. The carcinogenic effect could be enhanced by surface active agents, sodium chloride, iodoacetamide, insertion of plastic beads into the stomach and gastroenteroanastomosis. Follow-up studies by radiologic, endoscopic and bioptic examinations are possible in the dog. There are similarities in these experimental tumors to those in man and thus they provide means for the investigation of histogenesis, prevention, and chemotherapy of gastric cancer. An adenocarcinoma of the glandular stomach of a Wistar rat was successively transplanted to new born rats of the same strain.     

Detection and effects of helicobacters in healthy dogs and dogs with signs of gastritis

OBJECTIVES: To determine prevalence, colonization density, and distribution of helicobacters and gastric histologic findings in healthy dogs and dogs with signs of gastritis; to evaluate association of colonization density and gastric inflammation; and to compare the number of Helicobacter spp with degree of inflammation. DESIGN: Cross-sectional prevalence survey. ANIMALS: 25 healthy dogs and 21 dogs with signs of gastritis. PROCEDURE: During endoscopy, gastric mucosal biopsy specimens were obtained from healthy and affected client-owned dogs. Histologic and cytologic evaluation and results of a urease test were used for detecting helicobacters, which were identified definitively by use of transmission electron microscopy and bacterial culture. RESULTS: Helicobacters were detected in all 25 healthy and 20 of 21 affected dogs. Cytologic examination was a more sensitive method than histologic examination or the urease test. Helicobacters were found least frequently and in fewest number in the antrum in both groups of dogs. Gastric inflammation was evident in both groups of dogs and did not differ significantly between groups. A significant association was not detected between colonization density or the number of Helicobacter spp and degree of gastric inflammation. In both groups, H bizzozeronii, H felis, and H salomonis were cultured. CLINICAL IMPLICATIONS: Histologically verified chronic gastritis is common in dogs with signs of gastritis as well as in healthy dogs. Colonization density of helicobacters was not associated with degree of gastric inflammation in the dogs of our study. It remains to be determined whether certain strains of Helicobacter spp can induce gastritis in dogs.     

Effects of carbenoxolone Na on acute and chronic gastric ulcer models in experimental animals

Effects of carbenoxolone Na on acute or chronic types of gastric lesions or ulcer models produced in rats, guinea pigs, or dogs were studied. Carbenoxolone Na, given either orally or intraperitoneally, produced a significant inhibition of stress-induced gastric lesions in intact or in pylorus-ligated rats. Acetylsalicylic acid (ASA)-induced or serotonin-induced gastric lesions in rats were also inhibited significantly by pretreatment with the drug. However, carbenoxolone Na did not affect the development of Shay ulceration in rats even though the peptic activity in gastric juices was markedly reduced by the drug. Histamine-induced gastric lesions in guinea pigs were not prevented by pretreatment with carbenoxolone Na. Although carbenoxolone Na, given for 10-20 days, did not promote the healing of stress-induced gastric lesions and acetic acid gastric jlcers in rats, it significantly accelerated the healing of chronic gastric ulcer produced in dogs by 3 weeks' treatment. Carbenoxolone Na prevented the acid back-diffusion caused by ASA without any influence on Na+ efflux in pylorus-ligated rats.     

Current problems of extrapulmonary tuberculosis

The small intestine vagotomy influence on gastric secretion function, stimulated by pentagastrin and carbachol, was investigated while chronic experiment on dogs with gastric fundal and duodenal fistulas. The comparative analysis of influence of extragastric selective proximal, selective distal, selective and truncal vagotomy on gastric secretion in various terms after operative intervention was also conducted. In 6 months after conduction of various kinds of vagotomy the reduction of hydrochloric acid secretion, stimulated by pentagastrin, was noted.     

Gastric myoelectric and motor activity in dogs after isoflurane anesthesia

To characterize the effects of isoflurane on gastric motility, gastric electrical and contractile activities were assessed in six healthy adult dogs before and after recovery from anesthesia. Baseline recordings (fasting and fed state) were obtained in unanesthestized dogs 8 days after implantation of serosal electrodes and strain-gauge force transducers. After an overnight fast, dogs were anesthetized with 1.3 minimum alveolar concentration (MAC) isoflurane for 4.5 hours (approximately 6 MAC hours). No other anesthetic or sedative drugs were administered. During anesthesia, ventilation was mechanically controlled to maintain arterial carbon dioxide tension at 36 +/- 4 mm Hg. Gastric electrical and contractile activities (fasting and fed state) were recorded again 18 hours after recovery from isoflurane anesthesia. Recordings were analyzed to determine gastric slow-wave frequency, presence of slow-wave dysrhythmias, slow-wave propagation velocity, coupling of contractions to slow waves, a motility index based on relative contractile amplitudes, and onset and duration of contractions after a standardized meal. The only variable that was significantly decreased 18 hours after 6 MAC hours of isoflurane anesthesia was the gastric motility index during fasting-state phase III. This decrease was not apparent in the fed-state test periods. Our results suggest that, with the exception of gastric motility index during fasting-state phase III, variables for gastric electrical and contractile activities in dogs are unaffected by isoflurane 18 hours after anesthesia.     

Effect of age on serum concentrations of the third component of complement in dogs

Single radial immunodiffusion was used to determine the concentration of the third component of complement (C3) in canine sera from 48 normal dogs in the following age groups: < 12 months, 12 to 24 months, and > 24 months. Mean serum C3 concentrations, expressed as the percentage of pooled reference sera from 20 dogs, showed a significant (P < 0.017) correlation with age in dogs less than 12 months old, while the character of this correlation was negative for dogs more than 24 months old (P < 0.056). Two-way analysis of variance, for age and sex, revealed significant differences between C3 values from this two groups that were not present when compared with dogs aged between 12 and 24 months old. Sex had no effect on serum C3 concentrations.     

Gastric function after pylorus-preserving duodenectomy in dogs

BACKGROUND/AIMS: The purpose of this study was to delineate the alterations in gastric physiology after pylorus-preserving duodenectomy (PPD). METHODOLOGY: The duodenum was transected 2 cm distal to the pyloric ring in five dogs. A patch graft around the papilla of Vater was preserved. Reconstruction was completed using an end-to-end duodenojejunostomy, anastomosis of the patch graft to the jejunum, and cholecystojejunostomy, in that order. Gastric acid analysis, serum gastrin and secretin concentrations, and gastric emptying were investigated before and one and three months after surgery. RESULTS: The postoperative mean basal and maximal acid outputs were not significantly increased. Fasting serum gastrin concentrations remained unchanged. The fasting serum secretin concentrations one month after surgery increased significantly as compared to the controls. There were no significant differences in meal-stimulated gastrin or secretin responses or gastric emptying after surgery. CONCLUSIONS: The acid output and gut hormone release after PPD were maintained at preoperative levels. Preservation of the duodenal bulb is postulated to be responsible for the maintenance of near-normal gastric physiology.     

Effects of anaesthetics and trauma on stimulated gastric acid secretion in chronic fistula dogs

1. The present study was undertaken to determine whether various anaesthetic agents affect canine gastric acid secretion independently of other experimental variables. 2. Acid secretory output was determined in dogs with chronic fistulae, by administering sedating doses of anaesthetics commonly used for studying gastric secretory mechanisms in laboratory animals. 3. The anaesthetic agents inhibited gastric acid secretion. As the inhibitory effect of the mixture of anaesthetics was pronounced, an attempt was made to study the effect of each individual anaesthetic agent separately. 4. Acetopromazine was given to sedate dogs. Although it has a long duration of action, it only had a transient inhibitory action on gastric acid secretion of 15-30 min duration. Moreover the drug reduced pentagastrin-stimulated secretion, but had no effect on histamine-stimulated secretion. 5. Thiopentone sodium given with acetopromazine produced a mild inhibitory effect on histamine-stimulated secretion for 45 min, but produced a more pronounced and sustained inhibitory effect on pentagastrin-stimulated secretion. 6. Trilene significantly inhibited both histamine- and pentagastrin-stimulated secretion. The effect on the latter was more pronounced and sustained. 7. Trauma had no significant effect on histamine-stimulated secretion, but showed a slight inhibitory effect on pentagastrin-stimulated secretion. 8. Experiments to study gastric secretory mechanisms and antisecretory drugs should take account of the potential inhibitory effects of anaesthetics. Where possible, studies in conscious dogs with gastric fistulae are preferable to experiments on anaesthetized animals.     

Knee arthroplasty in rheumatoid arthritis. A report from the Swedish Knee Arthroplasty Register on 4,381 primary operations 1985-1995

The aim of this study was to determine whether the use of an ileal Roux limb, rather than a jejunal Roux limb, would prevent the Roux stasis syndrome that can occur after Roux gastrectomy. An ileal Roux limb was constructed in eight dogs and anastomosed to the gastric remnant after distal hemigastrectomy. Flow of chyme through the jejunum was preserved via an ileojejunostomy and a jejunoileostomy. Six dogs with distal gastrectomy and a conventional Roux gastrojejunostomy served as a control group. Chronic enteric recording electrodes and intraluminal, open-tipped pressure catheters were implanted in all dogs. After recovery, the electrical activity and motility of the Roux limbs and the rates of gastric emptying of liquids and solids were measured. Dogs with a Roux gastroileostomy had a slower frequency of pacesetter potentials in the Roux limb, a greater Roux motility index, and a faster rate of gastric emptying of liquids and solids than did dogs with a Roux gastrojejunostomy. Stomal ulcers, however, developed in seven of the eight ileal Roux limbs but in none of the jejunal Roux limbs. It was concluded that Roux gastroileostomy does ameliorate the Roux stasis syndrome, but there is a greater risk of stomal ulceration in the limb.     

Bromide therapy in refractory canine idiopathic epilepsy

On a retrospective basis, the response to adding chronic oral bromide (BR) to phenobarbital (PB) administration in 23 refractory canine idiopathic epileptics between 1986 and 1991 was studied. The mean age for an observed first seizure was 24 months (range 7 to 72) for all dogs. Thirteen (57%) dogs were males with no breed predisposition observed. All dogs were diagnosed as having idiopathic epilepsy based on normal metabolic and neurologic diagnostic evaluations. Dogs were evaluated before BR therapy for a mean time of 22 months (range 5 to 75 months). Seventeen dogs (74%) received multiple antiepileptic drugs (AEDs) before BR therapy. All animals were maintained on PB at least 4 months before the onset of BR therapy, with a mean trough serum concentration of 37.8 mcg/mL and no improvement in seizure severity or recurrence. Twelve dogs presented with generalized isolated seizures and 11 with generalized cluster seizures (two or more seizures within 24 hours) as their first seizure. The effects of BR therapy were evaluated for a mean time of 15 months (range 4 to 33), with 17 dogs (74%) followed for 12 or more months. The mean BR serum concentration for the 0 to 4 months time period was 117 mg/dL compared with 161 mg/dL for the greater than 4 months period. Overall, response to BR therapy was associated with a reduction in the total number of seizures in 83% of the dogs when compared with their respective pre-BR period. For those followed for 1 year after BR, there was a 53% reduction in the number of seizures compared with the previous 12 months. Furthermore, owners reported a decrease in seizure intensity (65% of dogs) and change to a less severe seizure type (22% of dogs) in those dogs that continued to have seizures. Seizure-free status was obtained in 26% of the dogs with protection continuing up to 31 months in one dog. No correlations could be determined between response to BR and either age of onset of the first seizure or interval from the first AED therapy to BR therapy. Adverse effects of concomitant BR and PB therapy were polydipsia (56% of dogs), polyphagia (30% of dogs), excessive sedation (30% of dogs), and generalized ataxia (17% of dogs). As a result of BR treatment, the PB dosage was reduced in eight dogs (35%). In conclusion, concomitant BR and PB was well tolerated in dogs of this study and was effective in treating refractory canine idiopathic epilepsy, regardless of prior interval of seizure activity or previous treatment.     

Intracerebroventricular neuropeptide Y increases gastric and pancreatic secretion in the dog

BACKGROUND: Neuropeptide Y (NPY), a centrally located neurotransmitter, is known to increase appetite in fasted and satiated animals. In addition to evaluating NPY's effect on eating behavior, this study was intended to determine whether intracerebroventricular (ICV) NPY would have an effect on canine gastric and pancreatic secretion. METHODS: Four dogs were prepared with cerebroventricular guides and gastric and pancreatic fistulas. ICV and intravenous NPY was administered during intragastric titration of a glucose and peptone meal. During this study, gastric and pancreatic secretion was measured, as well as insulin levels and pancreatic polypeptide (PP). An additional set of four dogs were prepared with esophageal fistulas and cerebroventricular guides, and the effect of ICV NPY on sham feeding was studied. RESULTS: ICV NPY significantly increased sham feeding, meal-stimulated gastric and pancreatic secretion, basal gastric acid, pancreatic bicarbonate, insulin levels, and PP. Vagotomy blocked the effect of ICV NPY on gastric acid secretion in a urethane-anesthetized rat model with acute gastric fistula. CONCLUSIONS: ICV NPY increased sham feeding, gastric and pancreatic secretion, insulin levels, and PP in the dogs. NPY's effect on gastric secretion was blocked by vagotomy in a rat model. NPY should be considered a candidate mediator of cephalic phase secretion.     

Gastric A-cell function in normal dogs

Glucagon release from the gastric fundus and pancreas were compared in normal dogs by measuring glucagon in plasma from a major gastroepiploic vein, the superior pancreaticoduodenal vein, and the inferior vena cava. In 32 dogs in the basal state, gastric vein glucagon averaged 97 +/- 40 pg/ml, not significantly different from the 93 +/- 41 pg/ml level in the vena cava. Pancreaticoduodenal vein glucagon averaged 250 +/- 32 pg/ml (P less than 0.001). Intravenous arginine infused in four dogs caused a rise in mean gastric vein glucagon to 210 +/- 33 pg/ml within 3 min, and glucagon remained between 53 and 98 pg/ml above the vena caval level thereafter. In the gastric vein, the rise in glucagon was significantly greater than in the vena cava at 3, 5, and 10 min (P less than 0.05), but was far less than in the pancreaticoduodenal vein where glucagon rose to 1,295 +/- 379 pg/ml at 1.5 min. Evidence of modest gastric glucagon release was observed after the intragastric instillation of arginine, but not during insulin or phloridzin-induced hypoglycemia. It was concluded that in normal dogs under the circumstances studied, the gastric fundus is not a major source of circulating glucagon.     

Isolation and identification of Helicobacter spp. from canine and feline gastric mucosa

It is known that virtually all healthy adult dogs and cats harbor spiral helicobacters in their gastric mucosa. Three species, Helicobacter felis, Helicobacter bizzozeronii, and Helicobacter salomonis have been isolated in vitro from the gastric mucosa of these animals. The aims of this study were to evaluate the efficacy of an isolation method for canine and feline gastric helicobacters that has been developed at the University of Helsinki; to estimate the prevalence and distribution of these taxa in the samples examined; and to assess the efficacy and validity of an extensive set of standardized conventional phenotypic tests, whole-cell protein profiling, and ultrastructural analysis in identifying the different species isolated from canine and feline gastric mucosa. We cultured 95 and 22 gastric mucosal biopsies from dogs and cats, respectively. Twenty-one H. bizzozeronii strains, 8 H. felis strains, 8 H. salomonis strains, 3 mixed cultures, 2 "Flexispira rappini"-like organisms, and 3 as yet uncharacterized strains were isolated from the dogs, and 3 H. felis strains were isolated from the cats. The methods used here yielded Helicobacter isolation rates of 51% from dogs and 13.6% from cats, which exceed those reported previously. The main difficulties were primary isolation, mixed cultures, and identification to the species level. In the species identification, a detailed morphological examination was found to yield important phenotypic characteristics. A large panel of biochemical and tolerance tests did not clearly differentiate the closely related species H. bizzozeronii, H. felis, and H. salomonis. Highly standardized whole-cell protein profiling was shown to be an excellent method for species identification. Improvements in culture conditions for these bacteria are still needed, especially for cats. A genetic identification method not requiring culture is needed for future studies of these very fastidious helicobacters, as the clinical significance and ecology of these species within the gastric mucosa of the domestic carnivores remain largely unknown.     

Cyanide toxicity and thiosulfate protection during chronic administration of sodium nitroprusside in the dog: correlation with a human case

Three adult spayed female hunting dogs had an unusual form of chronic active gastritis. The disease lasted for months to several years. Vomiting was the most consistent clinical sign. One dog had leukocytosis with 30 percent eosinophils. The stomach of each dog was enlarged and greatly thickened. Collagen deposits, granulation tissue and eosinophils replaced most of the gastric wall. Disease of the gastric arteries ranged from fibrinoid necrosis to panarteritis. Granulation tissue obstructed the omental arteries of one dog. There also was splenic reticuloendothelial hyperplasia with fibrosis, hemorrhage and congestion, and chronic eosinophilic lymphadenitis. Although the cause of this disease was not determined, its basis probably was immunologic.     

Use of food nutrition labels is associated with lower fat intake

The colon-targeted delivery capsule (CTDC), a new capsule-type dosage form for colonic delivery of drugs, was investigated for the in vivo drug release behavior in dogs. A CTDC formulation with prednisolone as a model drug and theophylline as a marker substance for gastric emptying was prepared for this study. The enteric-coated capsule (ECC) formulation with a similar composition was also prepared as the reference. Both formulations were administered to four beagle dogs, and the drug release behavior thereof was compared. Under fasted condition, ECC released prednisolone and theophylline at the same time within 1 h after the gastric emptying. On the other hand the CTDC released prednisolone at 3.2 h after the gastric emptying. Such release behavior of CTDC was approximately consistent with the results obtained from the in vitro dissolution study, suggesting that the pH-sensing and timed-release functions imparted to the CTDC can work in the gastrointestinal tract of dogs as programmed. Under non-fasted condition, however, the gastric emptying of CTDC was found to be considerably delayed, up to about 14 h, and in this case the in vivo dissolution lag time of prednisolone at the small intestine was shortened to about 1.5 h.     

Chlorpyrifos elicits mitotic abnormalities and apoptosis in neuroepithelium of cultured rat embryos

Case records of 27 dogs with medically managed congenital portosystemic shunts were reviewed. Fourteen were followed up by telephone questionnaires to the owners. Age, breed, sex, clinical signs and blood results were similar to previous studies. Weight and quality of life were stable or improved on treatment in all cases. Total serum protein concentration and alanine aminotransferase and alkaline phosphatase activities fell significantly during treatment. Fourteen dogs were euthanased, four were lost to follow-up and nine remained alive. Mean survival time for the dogs euthanased was 9.9 months. Mean follow-up period for the dogs still alive was 56.9 months and all had survived more than 36 months from diagnosis. Surviving dogs with intrahepatic shunts had a significantly shorter follow-up period than dogs with extrahepatic shunts. Two prognostic indicators were identified, age at initial signs and blood urea concentration on presentation, both correlating with survival time. It was demonstrated that a significant proportion of dogs with portosystemic shunts managed medically have a good prognosis.     

The effects of triethanolamine myristate, a fatty acid salt, on the bioavailability of riboflavin in dogs

A study in dogs was performed in which a physiologic approach to delaying gastric emptying was examined. Triethanolamine myristate (a fatty acid salt) was used to delay gastric emptying in hopes of increasing the bioavailability of riboflavin. A bilayer tablet consisting of triethanolamine myristate and riboflavin resulted in an absolute bioavailability of 2-3 times greater than the bioavailability of riboflavin alone. Increases in bioavailability although to a lesser extent, were also seen with the 30 min pretreatment with triethanolamine myristate. The results suggest that it was possible to delay gastric emptying.     

Serological survey of antibody to Neospora caninum in Japanese dogs

Prevalence of antibody to Neospora caninum (NC) in Japanese dogs were examined. The antibody was positive in 15 of 48 dogs (31.3%) reared in the dairy farms that had case of the abortions due to NC infection or had the cattle seropositive to NC, whereas the prevalence was 7.1% (14 of 198 dogs) among the dogs kept in urban areas. In one dog breeder, all 17 Shetland sheepdogs older than 7 months were seropositive, and one pup was diagnosed as neosporosis 2 months before the first serological examination. The antibody titers of the dogs kept at this breeder were almost unchanged for 1.5 years. Serological evidence of the dogs in the dairy farms and urban areas indicates the transmission of NC between dogs and cattle. Also serological results of the dogs in one breeder may suggest the potential horizontal transmission among dogs.