Aging. Increased responsiveness of colorectal mucosa to carcinogen stimulation and protective role of folic acid.

Recent investigations have demonstrated a protective role for folic acid in dysplasia and neoplasia, through an unknown mechanism. The current study was designed to evaluate whether the protective role of folic acid is due, in part, to its antiproliferative properties. In addition, because colorectal neoplasia is more common with increasing age, we have compared results in both old (22 months) and young (3 months) rats. Colorectal mucosal explants of rats treated with the known carcinogen methylazoxymethanol, were supplemented with folic acid. Ornithine decarboxylase was then measured as an index of cellular proliferative activity. We observed that supplemental folic acid suppressed carcinogen-induced ornithine decarboxylase activity by 64% in the old and 74% in the young rats. Furthermore, a similar phenomenon was observed for tyrosine kinase, which was measured for comparison. The suppression of hyperproliferative activity by supplemental folic acid may contribute to the protective effect of folic acid in colorectal neoplasia.

Helicobacter pylori-negative duodenal ulcer.

UNLABELLED: PURPOSE PATIENTS AND METHODS: Helicobacter pylori (HP) is present in more than 90% of duodenal ulcers (DUs). To investigate the pathophysiology in those patients with DU who are HP-negative compared with those who are HP-positive, we interviewed consecutive patients prior to endoscopy regarding factors often associated with ulcer disease. At esophagogastroduodenoscopy, antral biopsy specimens were obtained for urease test, culture, and Warthin Starry staining for HP in all patients with DU who did not have active bleeding. RESULTS: Compared with HP-positive patients who had DU, HP-negative patients with DU were more likely to be aspirin users and less likely to have had prior ulcers. HP-positive patients with DU had more severe antral inflammation than HP-negative patients. Whites were more likely to be HP-negative than blacks. HP-negative patients with DU most commonly presented with bleeding, whereas HP-positive patients with DU presented with pain. CONCLUSIONS: Our findings suggest a different mechanism for DUs in patients who are HP-positive versus those who are HP-negative, and this difference might have a bearing on treatment. The absence of HP should lead to a more thorough search for nonsteroidal anti-inflammatory drug/aspirin use, Zollinger-Ellison syndrome, and other potential causes of DUs.

Peritoneal mesothelioma: an unusual cause of esophageal achalasia.

Secondary esophageal achalasia due to malignancy is a rare condition; only 53 such cases have been reported to date. Sixty-two percent of the cases were due to gastric adenocarcinoma. Mesothelioma of the peritoneum is an uncommon neoplasm. The usual presenting symptoms are abdominal pain, abdominal mass, or abdominal distention. The patient we are reporting had peritoneal mesothelioma which presented with dysphagia and weight loss, in addition to the radiological and manometric picture of achalasia. Secondary achalasia was suspected clinically, and was confirmed by computed tomography and laparotomy. The diagnosis of peritoneal mesothelioma was made only by histopathological examination. We are not aware of any other report documenting the association of peritoneal mesothelioma and achalasia.

Barogenic perforation of the esophagus distal to a stricture after endoscopy.

Instrumentation is the most common cause of esophageal perforation, usually at or above a stricture. We report an unusual case in which the perforation occurred distal to a proximal esophageal stricture during diagnostic endoscopy. The perforation occurred close to the gastroesophageal junction involving an apparently normal esophagus, in a manner similar to that of "spontaneous," barogenic esophageal rupture (Boerhaave's syndrome). We postulate that the abrupt rise in pressure in the intraluminal esophagus, the inlet of which was obstructed by a tightly fitting instrument, was responsible for the rupture.

Papillary cystadenocarcinoma of the bile ducts resulting in hemobilia.

Cystadenocarcinoma is a rare tumor of the intrahepatic and a very rare tumor of the extrahepatic biliary system. In the reported cases, abdominal swelling is the most common presenting symptom, followed by right upper quadrant mass. Melena was the initial presenting symptom in the present case. Bleeding into the second part of the duodenum was observed only during the third diagnostic esophagogastroduodenoscopy. Hemobilia was suspected because of abnormal liver enzymes and a mass in the left lobe of the liver on computerized tomography. At laparotomy, we suspected that the mass was a hemangioma. Cystadenocarcinoma diagnosis was made only by histopathological examination.