Recipient‐related predictors of kidney transplantation outcomes in the elderly

Background It is not clear whether in old people with end‐stage renal disease kidney transplantation is superior to dialysis therapy. Methods We compared mortality rates between kidney transplant recipients ( KTR s) and the general population across different age categories. We also examined patient and allograft survival in 15 667 elderly KTR s (65–30 kg/m 2 ) was associated with 19% higher risk of graft failure ( HR : 1.19 [1.07–1.33], p = 0.002). Diabetes was a predictor of worse patient survival in all age groups but poorer allograft outcome in the youngest age group (65–<70 yr old) only. None of the examined risk factors affected allograft outcome in the oldest group (≥75 yr old) although there was a 49% lower trend of graft failure in very old Hispanic recipients ( HR : 0.51 [0.26–1.01], p = 0.05). Conclusions Kidney transplantation may attenuate the age‐associated increase in mortality, and its superior survival gain is most prominent in the oldest recipients (≥75 yr old). The potential protective effect of kidney transplantation on longevity in the elderly deserves further investigation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98362/1/ctr12106.pd

End-to-End Trainable Deep Active Contour Models for Automated Image Segmentation: Delineating Buildings in Aerial Imagery

The automated segmentation of buildings in remote sensing imagery is a challenging task that requires the accurate delineation of multiple building instances over typically large image areas. Manual methods are often laborious and current deep-learning-based approaches fail to delineate all building instances and do so with adequate accuracy. As a solution, we present Trainable Deep Active Contours (TDACs), an automatic image segmentation framework that intimately unites Convolutional Neural Networks (CNNs) and Active Contour Models (ACMs). The Eulerian energy functional of the ACM component includes per-pixel parameter maps that are predicted by the backbone CNN, which also initializes the ACM. Importantly, both the ACM and CNN components are fully implemented in TensorFlow and the entire TDAC architecture is end-to-end automatically differentiable and backpropagation trainable without user intervention. TDAC yields fast, accurate, and fully automatic simultaneous delineation of arbitrarily many buildings in the image. We validate the model on two publicly available aerial image datasets for building segmentation, and our results demonstrate that TDAC establishes a new state-of-the-art performance.Comment: Accepted to European Conference on Computer Vision (ECCV) 202

VITAMIN D RECEPTOR ACTIVATION AND A NOVEL CLASSIFICATION OF CARDIO-RENAL SYNDROME

Due to increasing survival rate of cardiac and renal disease patients, Cardiorenal syndrome (CRS), a combination of these two is becoming an important problem. Some classifications have been proposed for CRS but for clinical approach, it would be more appropriate to emphasize the pathophysiologic pathways to classify CRS into: 1\ hemodynamic, 2\ atherosclerotic, 3\ uremic, 4\ neurohumoral, 5\ anemic-hematologic, 6\ inflammatory-oxidative, 7\ vitamin D receptor (VDR) related, and 8\ multi-factorial CRS. Recently, it has been revealed that vitamin D and its receptor play an important role in the CRS. Decreased 1-α-hydroxylase activity, nutritional deficiency, decreased Megalin receptors, and increased 1-24-hydroxylase activity are major causes for vitamin D depletion in CKD. Decrease in GFR, renal mass and 1-α-hydroxylase expression along with phosphate retention, increased FGF-23, and loss of both 1-α-hydroxylase and 25(OH)vitamin D are important factors for decreased 1-α-hydroxylase activity. Suboptimal or defective VDR activation may play a role in causing or aggravating CRS. Newer VDR activators such as vitamin D mimetics (e.g. paricalcitol and maxacalcitol) are promising agents. Some studies have confirmed the survival advantages of D-mimetics as compared to non-selective VDR activators. Higher doses of D-mimetic per unit of PTH (paricalcitol to PTH ratio) are associated with greater survival, and the survival advantages of African American dialysis patients could be explained by higher received doses of paricalcitol. More studies are needed to verify these data and to explore additional avenues for CRS management via modulating VDR pathway

Cardiorenal syndrome: pathophysiology and potential targets for clinical management.

Combined dysfunction of the heart and the kidneys, which can be associated with haemodynamic impairment, is classically referred to as cardiorenal syndrome (CRS). Cardiac pump failure with resulting volume retention by the kidneys, once thought to be the major pathophysiologic mechanism of CRS, is now considered to be only a part of a much more complicated phenomenon. Multiple body systems may contribute to the development of this pathologic constellation in an interconnected network of events. These events include heart failure (systolic or diastolic), atherosclerosis and endothelial cell dysfunction, uraemia and kidney failure, neurohormonal dysregulation, anaemia and iron disorders, mineral metabolic derangements including fibroblast growth factor 23, phosphorus and vitamin D disorders, and inflammatory pathways that may lead to malnutrition-inflammation-cachexia complex and protein-energy wasting. Hence, a pathophysiologically and clinically relevant classification of CRS based on the above components would be prudent. With the existing medical knowledge, it is almost impossible to identify where the process has started in any given patient. Rather, the events involved are closely interrelated, so that once the process starts at a particular point, other pathways of the network are potentially activated. Current therapies for CRS as well as ongoing studies are mostly focused on haemodynamic adjustments. The timely targeting of different components of this complex network, which may eventually lead to haemodynamic and vascular compromise and cause refractoriness to conventional treatments, seems necessary. Future studies should focus on interventions targeting these components

Cardiorenal syndrome and vitamin D receptor activation in chronic kidney disease.

Cardiorenal syndrome (CRS) refers to a constellation of conditions whereby heart and kidney diseases are pathophysiologically connected. For clinical purposes, it would be more appropriate to emphasize the pathophysiological pathways to classify CRS into: (1) hemodynamic, (2) atherosclerotic, (3) uremic, (4) neurohumoral, (5) anemic-hematologic, (6) inflammatory-oxidative, (7) vitamin D receptor (VDR) and/or FGF23-, and (8) multifactorial CRS. In recent years, there have been a preponderance data indicating that vitamin D and VDR play an important role in the combination of renal and cardiac diseases. This review focuses on some important findings about VDR activation and its role in CRS, which exists frequently in chronic kidney disease patients and is a main cause of morbidity and mortality. Pathophysiological pathways related to suboptimal or defective VDR activation may play a role in causing or aggravating CRS. VDR activation using newer agents including vitamin D mimetics (such as paricalcitol and maxacalcitol) are promising agents, which may be related to their selectivity in activating VDR by means of attracting different post-D-complex cofactors. Some, but not all, studies have confirmed the survival advantages of D-mimetics as compared to non-selective VDR activators. Higher doses of D-mimetic per unit of parathyroid hormone (paricalcitol to parathyroid hormone ratio) is associated with greater survival, and the survival advantages of African American dialysis patients could be explained by higher doses of paricalcitol (&gt;10&nbsp;μg/week). More studies are needed to verify these data and to explore additional avenues for CRS management via modulating VDR pathway