Gastric mucosal damage caused by monochloramine in the rat and protective effect of taurine: endoscopic observation through gastric fistula.

BACKGROUND AND STUDY AIMS: The mechanism of Helicobacter pylori-induced gastric mucosal injury is unknown, but H. pylori infection is conducive to accumulation in the stomach of monochloramine, a cytotoxic substance. The present study involved morphological investigation of the damaging effects of monochloramine on rat gastric mucosa, using endoscopic observations through a gastric fistula. The study also examined the protective effect of taurine against monochloramine-induced gastric mucosal lesions in rats. MATERIALS AND METHODS: The effects of monochloramine in rats were studied by administering the substance via a gastrostomy, which was then used to conduct a series of endoscopic observations. Local blood flow was measured using a laser Doppler method. Histological examination was carried out after 24 hours. Various monochloramine concentrations were used, and some animals were pretreated with taurine, a monochloramine scavenger, via the gastrostomy. RESULTS: Endoscopically, monochloramine was found to produce hemorrhagic mucosal erosions, mainly in the gastric body, in a time-dependent and concentration-dependent manner. Blood flow was decreased in advance of mucosal erosion. Taurine prevented mucosal injury by 30 mM monochloramine, the highest concentration tested. CONCLUSIONS: Although only the first 24 hours of mucosal injury were observed in the present study, the most likely mechanisms by which monochloramine caused injury to the gastric mucosa appeared to be both oxidative damage and a reduction in blood flow, impairing the mucosal defense mechanism.

Effects of Postoperative Pericardial Effusion on Coronary Artery Bypass Grafts: A Study with X-ray Computed Tomography.

The aim of this study was to evaluate the effects of pericardial effusion on coronary artery bypass grafts and their patency using X-ray computed tomography (CT). Uncontrasted CT of horizontal sections from the lower margin of the aortic arch to the left ventricle was done at 5-mm intervals. In one cross-section of the pulmonary bifurcation level, 30 ml of a contrast media (lohexol 350) was injected at a rate of 3 ml/second into the antecubital vein. All slices of uncontrasted CT were analyzed for the presence or absence of effusion. The severity was expressed as the maximum value of the thickness of effusion. CT was repeated about every 6 months postoperatively under the same conditions. Selective angiography was also performed 7.1 +/- 3.9 months postoperatively. A total of 46 patients (mean age 57 years) underwent CT and angiography. A total of 95 grafts were implanted: 90 saphenous veins and 5 internal thoracic arteries. Selective angiography revealed that 79 grafts were patent and 16 were occluded. The first postoperative CT (at 2.6 +/- 2.1 months) showed the retention of effusion in all patients. The mean maximum value was 1.0 +/- 0.5 cm; there were no significant differences between patent grafts (1.0 +/- 0.5 cm) and occluded grafts (1.0 +/- 0.5 cm). Occlusion was found in 10 grafts by the first CT (2.9 +/- 2.7 months postoperatively) and another 6 grafts by the second CT (11.3 +/- 4.2 months). Thereafter, all grafts were patent. Previously occluded grafts showed no cross-section images on uncontrasted or contrasted CT. Except for two grafts, all patent grafts could be observed even without contrast enhancement. The remaining two grafts were masked with effusion, but patency was confirmed by a contrast media. In conclusion, retention of effusion does not affect the patency of grafts. Occlusion occurs early after surgery, and grafts cannot be imaged on CT. Patent grafts can be observed by uncontrasted CT, as well as contrasted CT, except where a large amount of effusion is present.

[A case of fibrous histiocytoma of the appendix with twisted stalk].

A 74-year-old man consulted this hospital with the chief complaint of lower right abdominal pain on February 13, 1998. He was hospitalized, subjected to abdominalechography and CT, and diagnosed as having subileus caused by an intraperitoneal tumor. Surgery was performed on February 25, 1998. When the abdomen was incised, a chicken egg-sized tumor at the end of theappendix were found. In addition, the stalk of the appendix was twisted. Appendectomy was therefore performed. Upon histopathological examination, it was found that the submucosal tumor originated at the end of the appendix, and proliferation of spindle-shaped fibroblast-like cells and histocytic oval cells was observed in the tumor. Since various histiocyte markers were positive upon immunohistological examination, the tumor was considered to be of histiocytic origin. However, the tumordid not exhibit polymorphism, heteromorphism, or mitotic figures which would confirm a diagnosis of malignant fibrous histiocytoma. It was thus diagnosed as a fibrous histiocytic tumor on the borderline between malignant and benign. We report the present case because the occurrence of a primary fibrous histiocytoma in an appendix of which the stalk is twisted is very rare.

[Continuous intra-arterial infusion chemotherapy in colorectal cancer patients with nonresectable metastatic liver cancer].

Five colorectal cancer patients with nonresectable metastatic liver cancer underwent continuous intraarterial chemotherapy in our institute from January to December 1991. Patients included four rectal cancers and one colonic cancer. 5-fluorouracil (5-FU) was infused continuously through an Infuse-A-Port; 360 mg/m2/day for one week after operation, and 180 mg/m2/day for the following three weeks. Since the fifth week after operation, two weeks without infusion and two weeks of infusion (180 mg/m2/day) were alternated as long as possible. Total periods of 5-FU infusion therapy were from one to 11 months and total doses of 5-FU ranged from 8,750 mg to 25,650 mg. Three patients showed partial response (PR) and two patients progressive disease (PD) (response rate; 60%). In three cases of PR, lengths of infusion therapy and total doses of 5-FU before PR was first observed was 8 weeks, 10,750 mg, 6 weeks, 9,250 mg, and 4 weeks, 8,750 mg, respectively. Four patients presented nausea, appetite loss or abdominal pain, which were considered to be side effects of 5-FU. In one of these four patients, infusion could not be continued because symptoms were so severe. However, catheter troubles were not noticed among all cases.

Mucin abnormality in colonic mucosa in patients with familial polyposis coli.

Colonic mucosa of the left colon in 41 patients with familial polyposis coli (FPC) was stained by a periodic acid-thionin Schiff/potassium hydroxide/periodic acid-Schiff method in which the normal colonic mucosa usually stained red and carcinoma stained blue or purple. In FPC 82.9% stained blue or purple whereas 35.5% stained blue or purple in normal controls. The data suggest that sialomucin properties of the flat mucosa surrounding polyps in FPC are different from those of the normal colon and that this simple technique may be useful for the early detection of high-risk family members in the FPC family.

[Endoscopic diagnosis and management of colonic polyps].

Colonoscopic diagnosis of colonic polyps is a rather easy task, although some small polyps might be missed when they are situated around the steep angulation or behind the fold. A correct diagnosis of mucosal carcinoma is difficult not only by colonoscopy but also by biopsy because the cancer focus may be small or not exposed on the polyp surface. Therefore, colonoscopic polypectomy is the best procedure of choice for correct histologic diagnosis of mucosal and invasive carcinoma. Only by polypectomy can correct diagnosis of invasive carcinoma be made, although there are various endoscopic signs such as irregularity of the surface configuration and white spots on the surrounding mucosa suggesting invasive carcinoma. Over the course of several years experience of colonoscopy we have encountered small flat elevations under 1 cm in diameter of which 58% were benign adenomas and 42% contained minute foci of carcinoma. These small flat lesions might have been missed quite easily during routine examination in the past and they might play an important role in the pathogenesis of colonic carcinoma. Benign polyp and mucosal carcinoma can be adequately treated by polypectomy only, whereas invasive carcinoma needs further treatment as it has a risk of node metastasis. Risk factors influencing metastasis are lymphatic permeation, poorly differentiated carcinoma, massive invasion close to the cut end. Only when one of these findings is seen in the removed polyp, further surgical treatment must be considered. However, the patient's general condition, age and site of the polyp should be carefully taken into account in order to choose the appropriate treatment in each individual case as the risk of metastasis under such situations mentioned above is not so high. Management of invasive carcinoma is still a controversial issue and a long-term, clinicopathologic study will be needed to solve this question.

Cross-reactivities of neuropeptide Y and peptide YY with pancreatic polypeptide antisera: evidence for the existence of pancreatic polypeptide in the brain.

Highly purified neuropeptide Y (NPY) and peptide YY (PYY) did not cross-react in our human pancreatic polypeptide (hPP) radioimmunoassay, nor did 125I-labelled NPY and PYY, even with anti-hPP serum at low dilution (1:1000). However, both [125I]NPY and [125I]PYY significantly cross-reacted with anti-bovine PP (bPP) serum at low dilution (1:1000, similar to that used in immunohistochemistry). These results suggest that radioassayable hPP-like peptide in the porcine or canine brain is probably pancreatic polypeptide itself, otherwise immunohistochemically detected bPP-like peptide may represent both NPY and PP.