Interest in nonimmunologic factors affecting longterm graft survival has focused on adequacy of nephron dosing. Body surface are (BSA) is a reliable surrogate for nephron mass. In a retrospective study of 378 primary recipients of paired kidneys from 189 cadaveric donors, we assessed the impact of matching donor and recipient BSA on outcome over 7 years. BSA of donors was 1.82 +/- 0.26 m2. Initially, paired recipients of kidneys from a single donor were divided into two groups. Group 1 included the recipient with the larger BSA of the pair (1.97 +/- 0.17 m2), while group 2 consisted of smaller BSA recipients (1.69 +/- 0.19 m2). Although early function was better in group 2 patients, graft survival at 1 year (77% vs. 79%) and 5 years (54% vs. 55%) was identical between groups, as were most recent serum creatinine levels (2.0 +/- 0.1 vs. 2.1 +/- 0.1 mg/dl). A second analysis divided patients with a functioning allograft at discharge from initial transplant hospitalization (n = 345) into three groups based solely on donor to recipient BSA ratio: the ratio of group A (n = 30) was < or = 0.8, that of group B (n = 255) was between 0.81 and 1.19, and that of group C (n = 51) was > or = 1.2. Graft survival and kidney function over 5 years did not differ among groups. In multivariate analysis of 17 variables, donor:recipient BSA, independent of other risk factors, did not affect risk allograft loss. These data indicate that including nephron mass as a criterion for cadaveric organ allocation is unlikely to improve long-term results in renal transplantation.
INTRODUCTION Locoregional variation in the human colon is important in surgical practice; the length and mobility of different colonic regions impacts on laparoscopic and endoscopic colorectal procedures. The aim of this study was to refine anatomical understanding of the colon in terms of segmental length and mobility. METHODS The colons of 35 cadavers were examined to determine lengths of caecum as well as ascending, transverse, descending and rectosigmoid colon, and to characterise colonic mobility at each location in terms of the mesenteric attachments. The presence of Jackson's membrane (a congenital peritoneal band of the right colon) was also documented. RESULTS The mean total colonic length was 131.2cm (standard deviation [SD]: 13.4cm). There was no correlation with height, age or sex; the best predictor of total colonic length was the length of the rectosigmoid segment. The mean height of the transverse mesocolon was 7.4cm (SD: 3.6cm) and that of the sigmoid mesocolon was 6.3cm (SD: 2.6cm). Two-thirds of the subjects had a mobile portion of the ascending colon and nearly one-third had a mobile descending colon. A mobile ascending colon was significantly more common in females. Jackson's membrane was present in 66% of the subjects. CONCLUSIONS This cadaveric study suggests that rectosigmoid length accounts for most of the variability in total colonic length. The significant proportion of colons with mobility of the ascending and descending segments prompts revision of the traditional anatomical teaching of these segments as fixed and retroperitoneal. Mobility of the ascending colon may account for the anecdotal finding that colonoscopy is more challenging in female patients. Jackson's membrane was identified in most colons.
Recently, market volatility has been used as an explanatory variable for presidential job approval. Our research builds on such an approach by first extracting the economic and non-economic components of market volatility using the Eta W (c4cast.com, Inc., 750 E. Walnut St., Pasadena, CA 91101) model, which considers 18 economic factors, far more than the unemployment and inflation factors used in most similar studies. Further, our results suggest that it is not aggregated market volatility but rather disaggregated market volatility that has a causal effect on presidential job approval ratings. In addition, the market's expectation of economic and non-economic market volatility exhibits different patterns, in terms of direction and timing, in their relationship to presidential job approval ratings.
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