Gastric nitrite processing in the surgically altered maximal and minimal bile reflux ferret model.

Ingested nitrate and nitrite have been shown to contribute to endogenous, N-nitroso compound formation in man and experimental animals. N-nitroso compounds have long been suspected of contributing to higher levels of gastric cancer in various populations. Reconstructive gastric surgery to treat ulcers is accompanied by a change in bile reflux, gastritis and an increased incidence of gastric cancer in humans. To evaluate possible connections between gastric nitrite processing, reconstructive surgery and gastric cancer, the surgically altered domestic ferret, Mustela putorius furo, was used as an experimental model. The aim of the study was to determine if surgery would alter the stomach in a way which would increase gastric nitrite concentration, and thereby enhance the likelihood of gastric N-nitroso compound formation. Three groups of ferrets, one control group (n = 6) and two groups of surgically altered ferrets, one to simulate maximal bile reflux (MABR, n = 6), and the other to model minimal bile reflux (MIBR, n = 7), were studied. Each group's response to an exogenously administered dose of sodium nitrite did not differ significantly with respect to rate of gastric nitrite absorption, with half-lives in the 13-min range. Permeability of gastric mucosa to nitrite did not differ between controls and MIBR ferrets. Mean doubling time of gastric nitrate appeared slowed in surgically altered ferrets. Mean rate of gastric emptying was the same in the three groups, but appeared delayed initially in MIBR ferrets. Thiocyanate concentrations, pH and HCl secretion, all parameters which have been shown to affect gastric nitrite processing, did not differ significantly between groups. Gastric mucosal endoscopic biopsies obtained at 6-month intervals showed no clear difference in degree of mucosal inflammation and/or dysplasia in the three groups. These findings indicate that gastric mucosal neoplasia has not occurred in this model and that changes in parameters favoring gastric N-nitrosation, even if relevant to the disease process, are not apparent at this time.

Bile reflux and the gastric mucosa: an experimental ferret model.

To study the effects of chronic bile reflux on the mammalian gastric mucosa, the ferret model was chosen for its practical aptitude and for its similarity to human gastric anatomy and physiology. A technique was first perfected for endoscopically directed gastric mucosal biopsy in the ferret. Subsequently, a surgical model of maximal enterogastric reflux (MR) and a control model of minimal reflux or "nonreflux" (NR) were developed. A stable population of 9 MR and 9 NR ferrets surviving 1-3 years has been established. All 18 animals, plus 6 nonoperative control animals, have undergone multiple repeat endoscopy and gastric biopsy without complication. The surgical and endoscopic techniques, with preliminary findings, are described.

Gastric colonization by Campylobacter pylori subsp. mustelae in ferrets.

Campylobacter pylori subsp. mustelae was cultured from both normal and inflamed gastric mucosa of ferrets. Examination of neonatal, juvenile, and adult ferrets established that the gastric mucosa in the majority of preweanling (age, less than 6 weeks) ferrets sampled were not colonized with C. pylori subsp. mustelae, whereas the gastric mucosa of 100% of adult ferrets were colonized with this gastric organism. C. pylori subsp. mustelae was isolated from the gastric mucosa on a sequential basis from nine ferrets during a several-month period, inferring either persistent colonization or frequent reinfection with C. pylori subsp. mustelae.

Campylobacter-like organisms isolated from gastric mucosa of ferrets.

Campylobacter-like organisms (CLO) were isolated from gastric lesions in 1 ferret and gastric mucosa of 2 healthy ferrets. The organism was not isolated from biopsies of gastric mucosa of 14 other healthy ferrets, 1 of which had small gastric lesions located at the pylorus. Lesions from which CLO were isolated were located in the antrum of 1 ferret and were classified as inflammation with repair. Affected gastric tissue was highly vascularized with fibrous connective tissue surrounding irregularly shaped glands. Necrosis and ulceration of adjacent mucosa also were observed. Using Warthin-Starry stain, Campylobacter-like organisms were seen on and in the glandular epithelium of the ferret with gastric lesions from which CLO were isolated.

Metastatic renal cell carcinoma to stomach.

Metastatic tumors to the stomach are distinctly unusual. Rarer still is renal cell carcinoma metastatic to the stomach following radical excision of the primary tumor several years previously. During evaluation for an upper gastrointestinal hemorrhage, a patient was found to have a large antral mass. Endoscopic biopsy revealed renal cell carcinoma. At celiotomy the tumor was found to have penetrated through to the liver capsule. An antrectomy and wedge resection of the left lobe of the liver was performed. There was no evidence of further metastatic disease. This is the first report of such a patient resected for cure, and emphasizes the unique biology of this tumor in its potential for late, solitary metastasis and surgical resectability.

Splenectomy in myeloid metaplasia.

A retrospective review of 19 patients with documented myeloid metaplasia undergoing, elective splenectomy during the past ten years at the Peter Bent Brigham Hospital is presented. The primary indications for splenectomy in 17 of these 19 were either hypersplenism or symptomatic splenomegaly. Eighteen of the 19 underwent both 59Fe-ferrokinetic studies and 51Cr-sequestration studies or, alternatively, 111In-marrow scintigraphy as a part of their routine preoperative evaluation. The death from sepsis of one patient six weeks post-operatively, whose marrow function was poor and whose level of splenic sequestration was minimal, confirms the efficacy of these studies in the preoperative prediction of hematologic response to splenectomy. Eighteen of the 19 patients benefited from the operation in terms of symptomatic relief and/or hematologic improvement, although surgery presumably did nothing to prolong survival in these patients. We conclude that splenectomy is indicated as a palliative maneuver for carefully selected patients with myeloid metaplasia without prohibitive operative risk, provided the criteria for selection of patients are adhered to and the surgeon and hematologist work together as a team.