The Diagnostic Accuracy of Abdominal Computed Tomography in Diagnosing Internal Herniation Following Roux-en-Y Gastric Bypass Surgery: A Systematic Review and Meta-analysis.

OBJECTIVE: To analyze the diagnostic accuracy of abdominal computed tomography (CT) in diagnosing internal herniation (IH) following Rouxen-Y gastric bypass (RYGB) surgery. SUMMARY OF BACKGROUND DATA: IH is one of the most important and challenging complications following RYGB. Therefore, early and adequate diagnosis of IH is necessary. Currently, exploratory surgery is considered the gold standard in diagnosing IH. Although CT scans are frequently being used, the true diagnostic accuracy in diagnosing IH remains unclear. METHODS: PubMed, Embase, and Cochrane databases were systematically searched for relevant articles describing the diagnostic accuracy of abdominal CT in diagnosing IH after RYGB. Data were extracted, recalculated, and pooled to report on the overall diagnostic accuracy of CT in diagnosing IH, and the diagnostic accuracy of specific radiological signs. RESULTS: A total of 20 studies describing 1637 patients were included. seventeen studies provided data regarding the overall diagnostic accuracy: pooled sensitivity of 82.0%, specificity of 84.8%, positive predictive value of 82.7%, and negative predictive value of 85.8% were calculated. Eleven studies reported on specific CT signs and their diagnostic accuracy. The radiological signs with the highest sensitivity were the signs of venous congestion, swirl, and mesenteric oedema (sensitivity of 78.7%, 77.8%, and 67.2%, respectively). CONCLUSIONS: This meta-analysis demonstrates that CT is a reliable imaging modality for the detection of IH. Therefore, abdominal CT imaging should be added to the diagnostic work-up for RYGB patients who present themselves with abdominal pain suggestive of IH to improve patient selection for explorative surgery.

The importance of determining the aggressiveness of prostate cancer using serum and tissue molecular markers.

Incidental prostate cancer (PCa) has been demonstrated at autopsy in about 80% of men aged 80 years and above and also in 10%-15% of younger men aged 30-50 years in the United States. These data imply a wide variation in aggressiveness of prostate cancer, from indolent tumors to aggressive cancers that kill the patients. The use of prostate specific antigen (PSA) in screening for PCa may detect even indolent disease for which radical prostatectomy may not be necessary. Currently available criteria such as histological grade, PSA level, stage of the disease do not always predict outcome. Furthermore, only about 80% of men with metastatic PCa will respond to first line hormone manipulation and once the patient develops hormone resistant prostate cancer (HRPCa), survival remains poor. Recent genomic and proteomic studies have provided many novel molecular markers that may help to redefine prognostic parameters. This paper is a review of studies using these novel markers in order to determine whether prostate cancer patients with the following characteristics have more aggressive cancer than those without: a) high serum levels of cathepsin B, survivin, Her - 2 / neu, IGFBP-2; b) low serum stefin A, IGFBP-3, c) positive immuno-staining of primary tumors for Her-2/neu, survivin and cathepsin B / stefin A ratio > 1 and d) gene expression of AMACR, HER-2/neu, high Bcl-2: Bax ratio and EZH2 in cancer cells. These markers have been chosen for review because they are among the most promising markers emerging currently.

ß-sitosterol prevents lipid peroxidation and improves antioxidant status and histoarchitecture in rats with 1,2-dimethylhydrazine-induced colon cancer.

Oxidative stress has become widely viewed as an underlying condition in diseases such as ischemia/reperfusion disorders, central nervous system disorders, cardiovascular disease, cancer, diabetes, etc. The role that antioxidants play in the process of carcinogenesis has recently gained considerable attention. ß-Sitosterol, a naturally occurring sterol molecule, is a relatively mild to moderate antioxidant and exerts beneficial effects in vitro by decreasing the level of reactive oxygen species. The present study evaluated the antioxidant potential of ß-sitosterol in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis. The enzymatic and nonenzymatic antioxidants and lipid peroxides in colonic and hepatic tissues were evaluated. Generation of reactive oxygen species, beyond the body's endogenous antioxidant capacity, causes a severe imbalance of cellular antioxidant defense mechanisms. Elevated levels of liver lipid peroxides by DMH induction were effectively decreased by ß-sitosterol supplementation. ß-Sitosterol also exhibited a protective action against DMH-induced depletion of antioxidants such as catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, and reduced glutathione in colonic and hepatic tissues of experimental animals. Supplementation with ß-sitosterol restored the levels of nonenzymatic antioxidants (vitamin C, vitamin E, and glutathione). Histopathological alterations in DMH-induced animals were restored to near normal in rats treated with ß-sitosterol. Thus, ß-sitosterol by virtue of its antioxidant potential may be used as an effective agent to reduce DMH-induced oxidative stress in Wistar rats and may be an effective chemopreventive drug for colon carcinogenesis.

Some sources and sinks of monomethyl and inorganic mercury on Ellesmere Island in the Canadian High Arctic.

We identified some of the sources and sinks of monomethyl mercury (MMHg) and inorganic mercury (HgII) on Ellesmere Island in the Canadian High Arctic. Atmospheric Hg depletion events resulted in the deposition of Hg(II) into the upper layers of snowpacks, where concentrations of total Hg (all forms of Hg) reached over 20 ng/L. However, our data suggest that much of this deposited Hg(II) was rapidly photoreduced to Hg(0) which then evaded back to the atmosphere. As a result, we estimate that net wet and dry deposition of Hg(II) during winter was lower at our sites (0.4-5.9 mg/ha) than wet deposition in more southerly locations in Canada and the United States. We also found quite high concentrations of monomethyl Hg (MMHg) in snowpacks (up to 0.28 ng/L), and at times, most of the Hg in snowpacks was present as MMHg. On the Prince of Wales Icefield nearthe North Water Polynya, we observed a significant correlation between concentrations of Cl and MMHg in snow deposited in the spring, suggesting a marine source of MMHg. We hypothesize that dimethyl Hg fluxes from the ocean to the atmosphere through polynyas and open leads in ice, and is rapidly photolyzed to MMHgCl. We also found that concentrations of MMHg in initial snowmelt on John Evans Glacier (up to 0.24 ng/L) were higher than concentrations of MMHg in the snowpack (up to 0.11 ng/L), likely due to either sublimation of snow or preferential leaching of MMHg from snow during the initial melt phase. This springtime pulse of MMHg to the High Arctic, in conjunction with climate warming and the thinning and melting of sea ice, may be partially responsible for the increase in concentrations of Hg observed in certain Arctic marine mammals in recent decades. Concentrations of MMHg in warm and shallow freshwater ponds on Ellesmere Island were also quite high (up to 3.0 ng/L), leading us to conclude that there are very active regions of microbial Hg(II) methylation in freshwater systems during the short summer season in the High Arctic.