Worsening risk for the development of dysplasia or cancer in patients with chronic ulcerative colitis.

Objectives: Patients with ulcerative colitis (UC) are at increased risk for developing dysplasia or cancer (neoplasia) and are usually offered colonoscopic surveillance to reduce their risk of cancer-related mortality. The causes of neoplasia may be related to features of UC (the extent, severity, activity, and age at onset of the disease) and to environmental factors (medications, vitamin and mineral supplementation, diet, or industrial pollutants). To determine whether and how the risk (and hence the risk factor profile) for the development of neoplasia changes over time, we conducted an historical cohort study.

Colectomy in patients with inflammatory bowel disease and primary sclerosing cholangitis.

Purpose: The aim of this study was to assess risk factors for early postoperative death in patients with primary sclerosing cholangitis who are undergoing colectomy.

Methods: The charts of 24 patients with primary sclerosing cholangitis who underwent colectomy between 1972 and 1990 at the Cleveland Clinic Foundation were reviewed. Clinical and laboratory data were collected and compiled to determine preoperative factors that might be helpful in predicting early postoperative death.

Endoscopic diagnosis of colonic endometriosis.

Involvement of the colon or rectum with endometriosis is uncommon but may be a cause of gastrointestinal symptoms such as diarrhea, pain, and bleeding. To determine whether endoscopy has a role in evaluating endometriosis of the colon, we reviewed all cases of endometriosis undergoing colonic resection from 1984 to 1989. There were nine patients, six of whom had intermittent hematochezia.

Hepatic portal venous gas: an unusual presentation of Crohn's disease.

Hepatic portal venous gas is associated with numerous conditions and traditionally has been regarded as an ominous prognostic sign. There are several reports of hepatic portal venous gas occurring in patients with inflammatory bowel disease after or during the performance of colonic diagnostic studies. We report an unusual case of Crohn's disease whose initial presentation included hepatic portal venous gas.

Endoscopic variceal ligation: an alternative to sclerotherapy.

Endoscopic variceal ligation (EVL) consists of mechanical ligation and thrombosis of varices using elastic "O" rings. This study assessed the efficacy and safety of EVL as definitive therapy for bleeding esophageal varices. During a 16-month period, 68 consecutive patients with bleeding varices had EVL.

Isolation and characterization of populations of mature and immature rat colonocytes.

A nonenzymatic method is described for the isolation of viable populations of mature and immature rat colonocytes. Histology was used to monitor colocyte dissociation and to systematically characterize the amount of cross-contamination between populations of mature luminal cells and immature crypt cells. The mature colonocytes were 87 +/- 9% pure with respect to contamination from cells from the lower half of the colonic crypt, and the immature populations were 98% pure with respect to contamination with cells from the upper half of the colonic crypt.

Mechanism of Lactobacillus leichmannii ribonucleotide reductase studied with Coalpha-[alpha-(Aden-9-yl)]-Cobeta-adenosylcobamide (Pseudocoenzyme B12) as coenzyme.

Coalpha-[alpha-(Aden-9-yl)]-Cobeta-adenosylcobamide (pseudocoenzyme B12) purified from Clostridium tetanomorphum has been reacted with ribonucleotide reductase purified from Lactobacillus leichmannii under various conditions, and the properties of the products obtained have been compared by electron paramagnetic resonance (EPR) with those previously reported for products formed from the normal coenzyme (adenosylcobalamin). The rapidly formed intermediate and the slowly formed "doublet" species from the pseudocoenzyme have EPR spectra identical with those formed from the normal coenzyme. This and other considerations make it less likely that the unusual magnetic properties of the rapidly formed intermediate are due to strongly distorted octahedral symmetry about Co(II) as previously postulated.