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Biomedical subjects

James M Becker

Publications and source records attributed to James M Becker.

25 records · Page 2Linked to original sources

Pouchitis in a rat model of ileal J pouch-anal anastomosis.

Endorectal ileal pouch-anal anastomosis (IPAA) has become the operation of choice for patients with chronic ulcerative colitis. Although this procedure improves the quality of life, pouchitis remains a significant postoperative complication. Because our understanding of the pathophysiology of pouchitis may, in part, be due to the lack of small animal model, our aim was to develop a model of IPAA in a rat that mimics its clinical counterpart. Colectomy, proctectomy, construction of an ileal J pouch, and ileal pouch-rectal anastomosis as a model of IPAA was performed in Sprague-Dawley and Lewis rats. Radiographic contrast studies were performed to quantitate intestinal transit. The presence of activated neutrophils was quantified by measuring mucosal myeloperoxidase (MPO) activity. Oxidative stress was quantitated by measuring urinary 8-isoprostane (8-IP) levels. Anaerobic and aerobic bacterial counts were determined on Brucella and tryptic soy agar plates, respectively. Dextran sulfate sodium (DSS) was used to exacerbate ileal J pouch inflammation. Mortality was low, and animals gained weight normally after recovery. Stasis was documented radiographically. MPO levels were elevated (p < 0.05) in the ileal J pouch 30 and 60 days after IPAA, indicating an inflammation that was associated with stasis and bacterial overgrowth. 8-IP levels were elevated by 80% compared with controls. Oral administration of 5% DSS to IPAA rats with further elevated MPO and 8-IP levels in concert with a pouchitis-like syndrome that included the physical, gross, and histologic characteristics of clinical pouchitis. An understanding of the pathophysiology of pouchitis is essential to the future development of new therapeutic modalities. This model is applicable to investigating several key etiologic mechanisms purportedly related to pouchitis.

Anal Canal↗

Distribution of polycyclic aromatic hydrocarbons in soils and terrestrial biota after a spill of crude oil in Trecate, Italy.

Ecological and human health exposures from soil-based petroleum-derived contaminants commonly are estimated by using soil-to-biota transfer factors that usually are based on octanol-water partitioning. Few studies of biota have been conducted in relation to spills of crude oils in terrestrial environments. After a large blowout of crude oil in northern Italy in 1994, the distribution of polycyclic aromatic hydrocarbons (PAHs) was examined over time and space in soils, uncultivated wild vegetation, insects, mice, and frogs in the area. Within two years of the blowout, PAH concentrations declined to background levels over much of the area where initial concentrations were within an order of magnitude above background, but had not declined to background in areas where starting concentrations exceeded background by two orders of magnitude. Octanol-water partitioning and extent of alkylation explained much of the variance in uptake of PAHs by plants and animals. The PAHs with lower octanol-water partition coefficients (K(ow)s) and higher-alkylated PAHs had higher biota-soil accumulation factors (BSAFs) than did high-K(ow) and unalkylated forms. The BSAFs for PAHs with higher K(ow)s were very low for plants, but much higher for animals, with frogs accumulating more of these compounds than other species.

Accidents↗

Anti-Saccharomyces cerevisiae antibodies are associated with the development of postoperative fistulas following ileal pouch-anal anastomosis.

Although serologic testing for perinuclear antineutrophil cytoplasmic antibodies (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) is reportedly useful in distinguishing ulcerative colitis (UC) from Crohn's disease (CD), there are few and conflicting reports assessing their utility in predicting postoperative complications after ileal pouch-anal anastomosis (IPAA). We examined the associations between postoperative complications such as pouchitis or fistulas and pANCA and ASCA antibodies in a group of patients who underwent IPAA for UC. We conducted a retrospective chart review of 34 patients initially diagnosed with UC (four of these patients had a diagnosis of indeterminate colitis) who underwent IPAA by a single surgeon, and who had pANCA and ASCA antibody levels measured during their clinical course. Study patients were assigned to four groups based on the pattern of antibody reactivity: pANCA+/ASCA- (16 patients), pANCA-/ASCA+ (nine patients), pANCA+/ASCA+ (five patients), and pANCA-/ASCA- (four patients). The median length of follow-up was 16 months (3-144 months). None of the patients (0 of 16) who were pANCA+/ASCA- had their preoperative diagnosis of UC changed after a median follow-up of 14 months (3-118 months). Of the nine patients with a preoperative diagnosis of UC who were pANCA-/ASCA+, four patients (44%) had their diagnosis changed postoperatively to CD based on clinical findings, with a median follow-up: 15 months (5-98 months). Of 16 patients who underwent IPAA and who were pANCA+/ASCA-, 15 of 16 (93.75%), were free of fistulas postoperatively, with a median follow-up of 14 months (3-118 months). Of nine patients with a preoperative diagnosis of UC who underwent IPAA and who were pANCA-/ASCA+, four of nine (44%; p = 0.04) developed fistulas postoperatively, with a median length of follow-up of 55 months (15-67 months). No relationship between serologic profiles or antibody titer levels and the development of pouchitis was identified. In a cohort of patients undergoing IPAA for UC, serologic profiles may be useful in identifying patients at risk of postoperative fistula formation. Patients who were pANCA-/ASCA+ were at increased risk for the development of fistulas postoperatively compared to patients who were pANCA+/ASCA-, and were also more likely to have their diagnosis changed postoperatively to CD. A larger study is needed to validate these observations.

Adolescent↗

Gastric outlet obstruction as a consequence of a duodenal web masquerading as gastrinoma in an adult.

We present the case of a 24-year-old man with recurrent peptic ulcers and hypergastrinemia, in whom a multidisciplinary investigation for gastrinoma revealed a duodenal web. The affected duodenal segment was excised, and a gastroduodenostomy with highly selective vagotomy was performed. Postoperative serum gastrin levels returned to the normal range over the next 6 weeks. Congenital duodenal anomalies are unusual causes of gastric outlet obstruction in adults. Chronic gastric outlet obstruction secondary to an adult duodenal web can induce neurohumoral changes in gastric function, which enhance both acid output and gastrin secretion. This case reminds clinicians to consider congenital anomalies in adults presenting with recurrent peptic ulcers and hypergastrinemia.

Adult↗