Enterocolic fistula: A rare presentation of cytomegalovirus infection.

In the present report, the first reported case of cytomegalovirus (CMV)-associated enterocolic fistula in an HIV/AIDS patient is described. CMV colitis is the second most common presentation of CMV infection in immunocompromised patients. CMV-associated enteric fistulae are an exceedingly rare complication, with only four previous cases described: a gastrocolic, an enterocutaneous, a rectovaginal and a colocutaneous fistula. Management of these patient demonstrates the importance of treating the precipitating viral infection before considering surgical intervention of the enterocolic fistula.

Dans le présent rapport, les auteurs décrivent le premier cas déclaré de fistule entérocolique associée au cytomégalovirus (CMV) chez un patient atteint du VIH-sida. La colite à CMV est la deuxième présentation en importance d'infection par le CMV chez les patients immunodéprimés. Les fistules entériques liées au CMV représentent une complication extrêmement rare puisque seulement quatre cas ont déjà été décrits : une fistule gastrocolique, une fistule entérocutanée, une fistule rectovaginale et une fistule colocutanée. La prise en charge de ce patient démontre l'importance de traiter l'infection virale déclencheuse avant d'envisager une intervention chirurgicale de la fistule entérocolique.

Postoperative Crohn's disease.

More than three quarters of patients with Crohn's disease (CD) will require surgery. After resection, disease recurs postoperatively with a median time to second resection of about 10 years. Despite its importance, the postoperative period remains one of the most poorly understood clinical settings in the field. Postoperatively, CD may exhibit unique pathophysiologic features, but the current state of knowledge does not allow for identification of patients at risk for relapse, and leaves clinicians without guidance on optimal maintenance treatment. Therapies used as maintenance for CD in other settings may have different efficacies when used after surgery, and clinical research in patients requiring surgery is limited by the subset of patients available for study. Despite the many limitations in current knowledge of postoperative CD, it is an exciting field because new developments have improved patient care, and ongoing research has the potential for further gains.

Resolution of multiple severe nonsteroidal anti-inflammatory drug-induced colonic strictures with prednisone therapy: a case report and review of the literature.

A 69-year-old woman on nonsteroidal anti-inflammatory drugs (NSAIDs) was admitted to a university hospital with abdominal pain, profound anemia and melena stools. Duodenal ulceration and subsequent healing were documented. Colonoscopy revealed haustral ulceration and NSAID-induced colonic diaphragm disease. Discontinuation of NSAID therapy did not result in endoscopic change, but a 20-week course of prednisone was followed by complete resolution. This is the first case describing prednisone monotherapy for such strictures, and only the second in which endoscopic resolution has been documented. With further supporting experience, prednisone may be considered in addition to NSAID discontinuation for patients with this rare but serious complication.

Diagnosis of a bleeding Dieulafoy lesion on computed tomography and its subsequent embolization.

Dieulafoy lesions are a potentially serious cause of gastrointestinal bleeding. Because they may bleed intermittently, and only be endoscopically evident during hemorrhage, their diagnosis can be challenging. This is the first case to be reported in the English literature of a patient with a Dieulafoy lesion diagnosed during computed tomography (CT) examination. Reduced acquisition times required for multislice helical CT allow the application of CT angiography in the diagnosis of gastrointestinal bleeding. CT scans are now widely used in the diagnostic algorithm for acute gastrointestinal hemorrhage, and the present case illustrates that with fortuitous timing, they can provide critical information and an opportunity for selected angiography and coil embolization.

Beta-galactosidases (Escherichia coli) with double substitutions show that Tyr-503 acts independently of Glu-461 but cooperatively with Glu-537.

Beta-galactosidases with single substitutions for Tyr-503, Glu-461, and Glu-537 and with double substitutions for Tyr-503 and either Glu-461 or Glu-537 were constructed. Control experiments showed that the very low kcat values obtained for the double-substituted enzymes were not a result of contamination, reversion, or nonactive site activity catalyzed on the surface of the proteins. Circular dichroism studies showed that the structures of the enzymes were intact. E461Q/Y503F-beta-galactosidase was inactivated in an "additive" manner. This indicated that Glu-461 and Tyr-503 act independently in catalysis. Because these residues are at opposite sides of the active site and act in different steps, this is expected. E537D/Y503F-beta-galactosidase was only inactivated a few-fold more than the most inactive of its two single-substituted constituent beta-galactosidases. This showed that Glu-537 and Tyr-503 interact cooperatively on the same step. This correlates well with the proposed role of Tyr-503 as an acid catalyst for the breakage of the covalent bond between Glu-537 and galactose.