RESUMEN
Williams syndrome is caused by a deletion of the elastin gene on chromosome 7. One of the main roles of this gene is to maintain the strength and elasticity of the intestinal wall, and the absence of the elastin gene may predispose these patients to gastrointestinal pathology such as diverticulitis. Our patient was a 35-year-old Caucasian female with Williams syndrome who presented to the emergency department with diffuse abdominal pain for two days. A computed tomography (CT) scan of her abdomen and pelvis initially showed locally perforated sigmoid diverticulitis with pelvic abscess and acute peritonitis. Surgical management was indicated after the patient failed to respond to conservative treatment. She was treated with Hartmann's procedure which showed purulent peritoneal fluid intraoperatively. Her hospital course was complicated by postoperative ileus and a peri-incisional abscess. After a 15-day hospital stay, she was discharged home with plans for ostomy reversal in six months. Patients with Williams syndrome have an increased risk of developing diverticulitis at a younger age than the general population due to their propensity for chronic constipation stemming from their child-like eating habits and low dietary fiber. Thus, we emphasize the importance of treating constipation in patients with Williams syndrome to prevent diverticulitis. If these patients present to the emergency department with acute diverticulitis, aggressive surgical management may be beneficial because rapid progression could ensue.
RESUMEN
The Rab11 family of small GTPases is composed of three members, Rab11a, Rab11b, and Rab25. While recent work on Rab11a and Rab25 has yielded some insights into their function, Rab11b has received little attention. Therefore, we sought to examine the distribution of endogenous Rab11b in epithelial cells. In rabbit gastric parietal cells, unlike Rab11a, Rab11b did not colocalize or coisolate with H(+)/K(+)-ATPase. In MDCK cells, endogenous Rab11b localized to an apical pericentrisomal region distinct from Rab11a. The microtubule agents nocodazole and taxol dramatically alter Rab11a's localization in the cell, while effects on Rab11b's distribution were less apparent. These results indicate that in contrast to Rab11a, the Rab11b compartment in the apical region is not as dependent upon microtubules. While Rab11a is known to regulate transferrin trafficking in nonpolarized cells and IgA trafficking in polarized cells, Rab11b exhibited little colocalization with either of these cargoes. Thus, while Rab11a and Rab11b share high sequence homology, they appear to reside within distinct vesicle compartments.