Inflammatory bowel disease.

The pathogenesis of inflammatory bowel disease (IBD) continues to be explored, with the emphasis on genetically determined host immune dysregulation as it applies to interactions with luminal bacteria. The role of endoscopic ultrasound in the evaluation of IBD continues to be studied. Recent advances in the evaluation of enterocutaneous fistulas have been made through the use of hydrogen peroxide to enhance definition of the fistula course and characteristics of the neighboring bowel, as evaluated by transabdominal ultrasound. Refinements have been made in the use and interpretation of the results of surveillance colonoscopy for detection of colorectal cancer and dysplasia in IBD, but a consistent approach still needs to be applied by individual practitioners. New data exist on the usefulness of methotrexate for maintenance of remission, while a lack of efficacy has been demonstrated for mesalamine in the prevention of postoperative recurrence. The role of anti-tumor necrosis factor (TNF) antibody therapy in the treatment of IBD continues to be investigated.

Colonoscopic miss rates of adenomas determined by back-to-back colonoscopies.

BACKGROUND & AIMS: The miss rate of colonoscopy for neoplasms is poorly understood. The aim of this study was to determine the miss rate of colonoscopy by same day back-to-back colonoscopy. METHODS: Two consecutive same day colonoscopies were performed in 183 patients. The patients were randomized to undergo the second colonoscopy by the same or a different endoscopist and in the same or different position. RESULTS: The overall miss rate for adenomas was 24%, 27% for adenomas < or = 5 mm, 13% for adenomas 6-9 mm, and 6% for adenomas > or = 1 cm. Patients with two or more adenomas at the first examination were more likely than patients with no or one adenoma detected at the first examination to have one or more adenomas at the second examination (odds ratio, 3.3; 95% confidence interval, 1.69-6.46). Right colon adenomas were missed more often (27%) than left colon adenomas (21%), but the difference was not significant. There was evidence of variation in sensitivity between endoscopists, but significant miss rates for small adenomas were found among essentially all endoscopists. CONCLUSIONS: Using current colonoscopic technology, there are significant miss rates for adenomas < 1 cm even with meticulous colonoscopy. Miss rates are low for adenomas > or = 1 cm. The results suggest the need for improvements in colonoscopic technology.

5-year incidence of adenomas after negative colonoscopy in asymptomatic average-risk persons [see comment].

BACKGROUND & AIMS: Cost-effectiveness of colorectal cancer screening will be maximized by selecting the widest screening intervals that effectively prevent cancer mortality. However, data on the incidence of neoplasia in persons with no abnormal findings on initial examination are limited. The aim of this study was to describe the incidence of colonic neoplasia 5 years after negative screening colonoscopy in asymptomatic average-risk persons. METHODS: We previously reported the results of screening colonoscopy in 496 asymptomatic average-risk persons, 368 of whom had no neoplasia identified. Colonoscopy to the cecum was performed in 154 of these persons at a mean of 66 months after the initial negative colonoscopy. RESULTS: Forty-one (27%) had at least one adenoma, but only 1 person had an adenoma > or = 1 cm and none had cancer, severe dysplasia, or villous or tubulovillous histology. Hyperplastic polyps at the initial examination did not predict incident adenomas. Regular nonsteroidal anti-inflammatory drug use was associated with a decreased rate of incident adenomas. CONCLUSIONS: In average-risk persons, the interval between screening examinations can be safely expanded beyond 5 years, provided the initial examination is a carefully performed complete colonoscopy that is negative for colonic adenomas or cancer.

Colonic adenomas in asymptomatic women with a history of breast cancer.

One hundred ninety-three asymptomatic women with a personal history of breast cancer underwent screening colonoscopy. One hundred sixty-eight women had breast cancer as their only potential risk factor for colonic neoplasia, and 25 had a family history of colorectal neoplasia in addition to their personal history of breast cancer. Among women with breast cancer, increasing age and body weight were each predictive of an increasing prevalence of colonic adenomas. The prevalence of colonic adenomas in women aged 50-75 yr whose only potential risk factor was breast cancer was 18%, and was identical to the prevalence of colonic adenomas in 186 asymptomatic average-risk control women aged 50-75 yr (odds ratio 1.0, 95% CI 0.54-1.87). We conclude that a personal history of breast cancer does not predict a higher prevalence of colonic adenomas.

Colonic neoplasia in asymptomatic persons with negative fecal occult blood tests: influence of age, gender, and family history.

Six hundred twenty-one asymptomatic persons with negative fecal occult blood tests (ages 50-75 yr), including 496 with no known risk factors for colorectal cancer and 125 with a single first-degree relative with a history of colonic neoplasia developed after age 40, underwent screening colonoscopy. Three Dukes A cancers were detected in average-risk persons. The overall prevalence of adenomatous polyps was 27%. Multiple logistic regression analysis revealed that increasing age and male gender were both strong predictors of colonic neoplasia (p < 0.001). A positive family history of a single first-degree relative with colorectal cancer was not associated with an increased prevalence of colonic neoplasia (p = 0.29), although an effect may be present if the relative was < 60 yr at diagnosis. Overall 16% of males and 7% of women > or = 60 yr had at least one adenoma that was large (> or = 1 cm in size), villous or tubulovillous, or had grade 3 dysplasia. We conclude that the prevalence of colonic neoplasia in asymptomatic persons with negative fecal occult blood tests is substantial, particularly in elderly males. A family history of a single first-degree relative diagnosed at age > or = 60 yr with colorectal cancer is not associated with an increased prevalence of colonic adenomas.

Distribution of isoelectric variants of the 17,000-dalton myosin light chain in mammalian smooth muscle.

Isoelectric focusing of purified vascular smooth muscle myosin revealed two variants of the 17,000-dalton light chain subunits. The isoelectric points of the light chain variants were determined to be 4.13 (LC17a) and 4.19 (LC17b). Tryptic peptide maps of the two species of light chain generated by reverse-phase high performance liquid chromatography disclosed small but obvious differences in peptide composition while amino acid analyses of the variants were quite similar. Two-dimensional electrophoresis of extracts from various mammalian smooth muscles revealed tissue-specific differences in the relative content of LC17a and LC17b. Vascular (aorta, carotid, and pulmonary artery) muscles and tracheal smooth muscle contained both light chain variants while smooth muscle of the gastrointestinal tract (stomach and jejunum) contained LC17a only. The actin-activated Mg2+-ATPase activities of both phosphorylated and nonphosphorylated stomach (LC17b = 0) and aortic (LC17b = 40%) myosins were compared. In the presence of saturating tropomyosin, a 2-fold difference in Vmax was measured: phosphorylated, aortic, 0.119 +/- 0.009 versus stomach, 0.239 +/- 0.012 mumol of PO4 liberated/min/mg of myosin; nonphosphorylated, aortic, 0.065 +/- 0.004 versus stomach, 0.123 +/- 0.004 mumol of PO4 liberated/min/mg of myosin. In addition, the Vmax of myosin subfragment-1 ATPase from bovine aortic, pulmonary artery, and stomach myosins (LC17b contents, 40, 20, and 0%, respectively) was found to decrease in direct proportion to the LC17b content. Our results suggest that isoforms of the 17,000-dalton light chain subunits of mammalian smooth muscle myosin could play an important role in modulating actomyosin ATPase activity.

Diastolic collapse of the right ventricle with cardiac tamponade: an echocardiographic study.

The value of a newly described echocardiographic sign for the detection of cardiac tamponade was retrospectively evaluated in 91 patients. M-mode echocardiograms were reviewed in 86 patients, 36 of whom had concurrent two-dimensional echocardiographic examinations; in five patients, only two-dimensional echocardiography was performed. Cardiac tamponade was clinically present in 17 patients, 14 of whom had abnormal posterior motion of the right ventricular free wall in early diastole. Two of the 17 patients with tamponade had equivocally abnormal motion and one had normal wall motion. The patient with normal wall motion was later proved to have predominantly constrictive pericardial disease. In all cases, the abnormal wall motion reverted to normal after a definitive drainage procedure. Two-dimensional echocardiography confirmed that the abnormal right ventricular wall motion represented a true collapse of the right ventricular cavity in early diastole. Of the 69 patients without clinical cardiac tamponade, only seven had abnormal right ventricular wall motion. Detection of abnormal diastolic right ventricular free wall motion may be a sensitive indicator or a hemodynamically significant pericardial effusion. Conversely, the presence of normal motion of the right ventricular free wall appears to be a reliable indicator that the pericardial effusion is exerting little effect on overall cardiac function.