RESUMEN

The aim of this study was to examine the effects of varying doses of pirenzepine, a selective muscarinic subtype M1 antagonist, on the prevention of acute gastric mucosal lesions in male Sprague-Dawley rats subjected to spinal cord section at the C7 level. It was also intended to evaluate the effects of the drug on gastric acid output and gastric mucosal blood flow. Pirenzepine 1, 2.5 and 5 mg/kg every 2 h all caused a significant reduction in mean total ulcer length (p less than 0.01) compared to controls. This was associated with a significant decrease in acid output (p less than 0.05). There was no significant effect on gastric mucosa blood flow as measured by hydrogen gas clearance. These results indicate that the protective effects of pirenzepine on gastric mucosa, in the spinal rat model, are associated with the acid-inhibitory action of the drug and not on mucosal blood flow effects.

Asunto(s)

RESUMEN

It is common clinical practice to test stools for occult blood and to rely heavily upon the result in deciding whether to investigate further. Because the accuracy of such testing has been questioned, a study was conducted to estimate the sensitivity of the Hemoccult II slide test in detecting colonic carcinoma and polyps. Patients with lesions demonstrated on barium enema roentgenography had their stools examined for occult blood. One to 2 weeks before colonoscopy, stool specimens were collected for 3 consecutive days according to the manufacturer's instructions. The sensitivity of occult blood testing was 38% for patients with benign polyps and 64% for patients with polypoid carcinomas. Thus, the authors conclude that the Hemoccult II test is not reliable as a diagnostic tool and that a negative test result does not exclude the presence of a colonic neoplasm in any patient.

Asunto(s)

RESUMEN

To assess the efficacy of cimetidine versus Mylanta II in the prevention of stress erosions, 44 patients at risk were randomized to receive cimetidine 300 mg/6 h intravenously to a maximum of 400 mg/4 h; or Mylanta II 30 ml/h through a nasogastric tube to a maximum of 90 ml/h. The minimum dose of medication was used to maintain hourly gastric pH greater than or equal to 4. All patients were to be endoscoped after 72 h and erosions graded by an endoscopist who had no knowledge of their treatment regime. Grade 3 or 4 erosions occurred in five of 21 cimetidine-treated patients and eight of 16 antacid-treated patients (p greater than 0.05). A gastric pH greater than or equal to 4 was maintained 79.5% of the time by cimetidine and 97.9% of the time by Mylanta II (p less than 0.001). Cimetidine and antacids are equal in the prevention of stress erosions although Mylanta II is superior in hourly pH control. Hourly pH control does not entirely explain the beneficial effect of cimetidine in the prevention of stress ulcers. There was no significant bleeding in this study. Fatalities in patients at risk of developing stress ulcers result from the underlying disease, not from hemorrhage from stress-induced mucosal lesions. In critically ill patients, endoscopic examination should be restricted to the rare case with manifest hemorrhage.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

By contract with the National Cancer Institute, the accuracy of diagnostic techniques was assessed in 184 patients suspected of having pancreas cancer. Of 138 patients who were operated upon, 89 were found to have pancreas duct cancer, 30 had cancer of a different site of origin in the head of the pancreas region and in 19 there was no evidence of cancer at operation. All of the 46 patients who were not operated upon, 13 proven to have cancer and 33 patients discharged as free of cancer, were followed in our clinic. The majority of our patients presented with signs and symptoms of biliary obstruction. Computerized transaxial tomography (CTT) gave a "correct" diagnosis in 31 of 33 patients (94%) with proven cancer, there were 2 patients with a false negative report and a false positive diagnosis occurred in 8 of 20 patients (40%) without cancer. Celiac angiography (CA) gave a correct diagnosis in 78 of 94 patients (83%) with cancer, a false negative in 17%, and a false positive in 32%. 76Selenomethionine pancreas scan correctly diagnosed 27 of 36 patients (75%) with cancer, gave a false negative in 25% and a false positive in 31%. Ultrasonography gave a correct diagnosis in 18 of 27 patients with cancer (67%), a false negative in 33% and a false positive in 28%. Endoscopic retrograde cholangiopancreatography diagnosed correctly 8 of 11 cases (73%) of cancer, there were false negative diagnoses in 3 cases (27%) and false positives in 3 of 14 patients (21%). Duodenal aspiration techniques gave a very low percentage of correct diagnoses. Chronic pancreatitis most commonly gave rise to a false positive diagnosis. Serum alkaline phosphatase was elevated in 82% of patients, gave 18% false negatives and 33% false positives. Carcinoembryonic antigen (CEA) was elevated (greater than 2.5 ng/ml) in most of the pancreas cancer patients but also in patients with other cancers and with non-cancerous diseases. In our hands, CTT, CA, alkaline phosphatase, 75Se-methionine and ultrasonography, in descending order, have given the highest percentage of correct diagnoses but false positive and false negative diagnoses prevented any single test from being conclusive.

Asunto(s)