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Evolutionary radiations of woody taxa within arid environments were made possible by multiple trait innovations including deep roots and embolism-resistant xylem, but little is known about how these traits have coevolved across the phylogeny of woody plants or how they jointly influence the distribution of species. We synthesized global trait and vegetation plot datasets to examine how rooting depth and xylem vulnerability across 188 woody plant species interact with aridity, precipitation seasonality, and water table depth to influence species occurrence probabilities across all biomes. Xylem resistance to embolism and rooting depth are independent woody plant traits that do not exhibit an interspecific trade-off. Resistant xylem and deep roots increase occurrence probabilities in arid, seasonal climates over deep water tables. Resistant xylem and shallow roots increase occurrence probabilities in arid, nonseasonal climates over deep water tables. Vulnerable xylem and deep roots increase occurrence probabilities in arid, nonseasonal climates over shallow water tables. Lastly, vulnerable xylem and shallow roots increase occurrence probabilities in humid climates. Each combination of trait values optimizes occurrence probabilities in unique environmental conditions. Responses of deeply rooted vegetation may be buffered if evaporative demand changes faster than water table depth under climate change., (© 2023 The Authors. New Phytologist © 2023 New Phytologist Foundation.)

Certain patient groups are predicted to derive significant survival benefit from transplantation with expanded criteria donor (ECD) kidneys. An algorithm published in 2005 by Merion and colleagues characterizes this group: older adults, diabetics and registrants at centers with long waiting times. Our goal was to evaluate ECD listing practice patterns in the United States in terms of these characteristics. We reviewed 142 907 first-time deceased donor kidney registrants reported to United Network for Organ Sharing (UNOS) between 2003 and 2008. Of registrants predicted to benefit from ECD transplantation according to the Merion algorithm ('ECD-benefit'), 49.8% were listed for ECD offers ('ECD-willing'), with proportions ranging from 0% to 100% by transplant center. In contrast, 67.6% of adults over the age of 65 years were ECD-willing, also ranging from 0% to 100% by center. In multivariate models, neither diabetes nor center waiting time was significantly associated with ECD-willingness in any subgroup. From the time of initial registration, irrespective of eventual transplantation, ECD-willingness was associated with a significant adjusted survival advantage in the ECD-benefit group (HR for death 0.88, p < 0.001) and in older adults (HR 0.89, p < 0.001), but an increased mortality in non-ECD-benefit registrants (HR 1.11, p < 0.001). In conclusion, ECD listing practices are widely varied and not consistent with published recommendations, a pattern that may disenfranchise certain transplant registrants.

Context: Although risks associated with live kidney donation are low, there are few pathologic studies of kidneys from live donors, and possible risk factors for development of hypertension or renal insufficiency remain unknown. There are many studies of histopathologic changes in deceased donor kidneys and how these changes affect subsequent graft function; most are based on wedge rather than needle core biopsies., Objective: To examine the frequency and severity of arterial fibrointimal thickening and other pathologic lesions in kidneys from healthy live donors and compare wedge and needle core biopsies as methods for evaluating these changes., Design: For 36 of 332 live donor renal transplantations performed from January 2004 through November 2006, a wedge biopsy of the transplanted kidney was done prior to and/or after implantation, and a needle core biopsy was done postimplantation or during the ensuing 7 days. For these 36 allografts, we compared pathologic features of the wedge and core perioperative biopsies., Results: Findings on core and wedge biopsies were similar, except for arterial fibrointimal thickening. Moderate thickening (Banff cv2) was present on 13 core biopsies, and mild thickening (cv1) was present on another 10; by contrast, no wedge biopsies showed cv2 lesions, and only 8 showed cv1. Arterial thickening on core but not wedge biopsies correlated significantly with increasing patient age., Conclusions: The findings indicate that needle core biopsies are superior to wedge biopsies for evaluating vascular changes in donor kidneys, and they suggest a need for studies correlating such changes with long-term outcomes of live donors, particularly older donors.

A stagnant supply of transplantable organs in the face of a relentless burgeoning of transplant waiting lists has created a crisis. Necessity continues to be the mother of invention and as the crisis has deepened it has served as a crucible for the development of new ways to think about perennial problems. Our program has taken a 2-pronged approach to increasing the organ supply for our patients. First, through innovations like the laparoscopic donor nephrectomy, ABO-incompatible and positive-crossmatch transplantation protocols, unconventional paired kidney exchanges, and the use of altruistic donors we have more than doubled our utilization of live donor organs. At the same time, we have developed algorithms and interrogative techniques to enhance the intelligent use of kidneys from expanded criteria donors for patients who do not have an available live donor. The laparoscopic nephrectomy has proven to be a safe and effective way of removing a significant barrier to live donation. Our results from 100 ABOi, (+)XM, and PKE transplants are similar to national statistics for compatible live donor transplants, suggesting that existing paradigms of compatibility can be safely expanded. These encouraging early outcomes and the savings they transmit to the health care system have allowed us to obtain insurance coverage for the InKTP programs, setting the stage for further expansion of these opportunities to broaden the options for patients with end-stage renal disease.

Bowel anastomoses are conventionally performed using a handsewn technique or a stapling device. Each has potential benefits and disadvantages. The most clinically significant complications of the bowel anastomosis are anastomotic leakage and stricture formation. The indices of healing and tissue cohesion were compared dynamically over time in 24 dogs randomized to undergo either a standard two-layer handsewn anastomosis or a stapled anastomosis with the Premium CEEA (United States Surgical Corporation, Norwalk, CT). Animals were sacrificed at 1, 4, 7, and 28 days postoperatively. Each anastomosis was evaluated for anastomotic index, burst pressure, collagen content, and histologic appearance. The anastomotic index was similar on postoperative day (POD) 1, 4, and 7; but on day 28 all handsewn anastomoses had larger diameters than the widest CEEA anastomosis. Burst pressure was higher in handsewn anastomoses at all intervals. Collagen content tended to be higher on POD 7 in the CEEA anastomoses. Histological evaluation showed more complete epithelialization and less inflammation in handsewn anastomoses on POD 28. The higher level of collagen in the CEEA anastomoses on POD 7 may be implicated in the tendency toward stricture formation found with this type of anastomosis. This study demonstrates that the greater speed and ease of the stapled anastomosis is offset by the greater strength, reduced tendency to stricture, and more complete healing of the handsewn anastomosis.