Distal Margins in Radical Resections for Rectal Cancer after Chemoradiation Therapy: How Short Is Long Enough?

&lt;i&gt;Background:&lt;/i&gt; The purpose of our study was to assess the impact of distal margin length on outcome in patients with rectal cancer treated with neoadjuvant chemoradiation therapy (CRT) followed by radical resection. &lt;i&gt;Methods:&lt;/i&gt; Fifty-three consecutive patients were evaluated. The selection criteria included: adenocarcinoma of the mid- or distal rectum, locally advanced stage, absence of distant metastases, and preoperative CRT followed by proctectomy with total mesorectal excision. The operations included low anterior resection in 33 patients (62%) and abdominoperineal resection in 20 (38%). The outcome measures were: tumor regression, complete pathologic response, length of distal resection margins, status of radial margins and recurrence rate. &lt;i&gt;Results:&lt;/i&gt; Forty-eight patients (91%) had tumor regression, and 11 (21%) had a complete pathologic response. Distal resection margins were tumor-free in all patients, ranging in length from 0.1 to 7.4 cm (mean = 2.2). Follow-up (mean = 48.8 months) was current in 50 of 53 patients (94%). There was no locoregional recurrence. &lt;i&gt;Conclusions:&lt;/i&gt; Distal resection margins shorter than 1–2 cm appear to be equivalent to longer margins in patients who undergo CRT followed by proctectomy with total mesorectal excision. These findings may lead to greater utilization of sphincter-saving procedures in rectal cancer.</jats:p

<i>Does Alvimopan Enhance Return of Bowel Function in Laparoscopic Right Colectomy?</i>

Alvimopan, a peripherally acting Mu-opioid receptor antagonist, has been shown to enhance recovery of gastrointestinal (GI) function in open bowel resection. The aim of this study was to determine the effect of Alvimopan on patients undergoing laparoscopic right colectomies in preventing postoperative ileus (POI). A prospective, nonrandomized trial of laparoscopic right colectomies was carried out with and without perioperative Alvimopan. The length of stay (LOS), time to first flatus, bowel movement, and tolerance of solid foods were recorded. Additionally, any occurrences of POI defined as the need for insertion of a nasogastric tube (NGT) were also noted. Student t tests were used for statistical analysis. A total of 33 patients underwent laparoscopic right colectomies for both benign and malignant diseases from October 2008, to December 2009. Sixteen patients received Alvimopan, whereas 17 patients did not. The demographics of both patient groups were similar. Patients receiving Alvimopan had an accelerated return of bowel function in terms of first flatus (2.37 vs 3.34; P = 0.03), tolerance of solid food (2.75 vs 3.94; P = 0.03), and first stool (2.53 vs 3.80; P = 0.04). There was a trend toward shorter LOS in patients receiving Alvimopan ( P = 0.07). Two patients with POI requiring NGT did not receive Alvimopan. Alvimopan was successful in enhancing return of GI function in laparoscopic right colectomies and avoiding POI. The decreased LOS trended but did not approach statistical significance. A large randomized prospective trial will be needed to determine the validity of this study.</jats:p

Proteomics of Secretory and Endocytic Organelles in Giardia lamblia

Giardia lamblia is a flagellated protozoan enteroparasite transmitted as an environmentally resistant cyst. Trophozoites attach to the small intestine of vertebrate hosts and proliferate by binary fission. They access nutrients directly via uptake of bulk fluid phase material into specialized endocytic organelles termed peripheral vesicles (PVs), mainly on the exposed dorsal side. When trophozoites reach the G2/M restriction point in the cell cycle they can begin another round of cell division or encyst if they encounter specific environmental cues. They induce neogenesis of Golgi-like organelles, encystation-specific vesicles (ESVs), for regulated secretion of cyst wall material. PVs and ESVs are highly simplified and thus evolutionary diverged endocytic and exocytic organelle systems with key roles in proliferation and transmission to a new host, respectively. Both organelle systems physically and functionally intersect at the endoplasmic reticulum (ER) which has catabolic as well as anabolic functions. However, the unusually high degree of sequence divergence in Giardia rapidly exhausts phylogenomic strategies to identify and characterize the molecular underpinnings of these streamlined organelles. To define the first proteome of ESVs and PVs we used a novel strategy combining flow cytometry-based organelle sorting with in silico filtration of mass spectrometry data. From the limited size datasets we retrieved many hypothetical but also known organelle-specific factors. In contrast to PVs, ESVs appear to maintain a strong physical and functional link to the ER including recruitment of ribosomes to organelle membranes. Overall the data provide further evidence for the formation of a cyst extracellular matrix with minimal complexity. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD000694