Current Therapy in CKD Patients Can Affect Vitamin K Status

Chronic kidney disease (CKD) patients have a higher risk of cardiovascular (CVD) morbidity and mortality compared to the general population. The links between CKD and CVD are not fully elucidated but encompass both traditional and uremic-related risk factors. The term CKD-mineral and bone disorder (CKD-MBD) indicates a systemic disorder characterized by abnormal levels of calcium, phosphate, PTH and FGF-23, along with vitamin D deficiency, decreased bone mineral density or altered bone turnover and vascular calcification. A growing body of evidence shows that CKD patients can be affected by subclinical vitamin K deficiency; this has led to identifying such a condition as a potential therapeutic target given the specific role of Vitamin K in metabolism of several proteins involved in bone and vascular health. In other words, we can hypothesize that vitamin K deficiency is the common pathogenetic link between impaired bone mineralization and vascular calcification. However, some of the most common approaches to CKD, such as (1) low vitamin K intake due to nutritional restrictions, (2) warfarin treatment, (3) VDRA and calcimimetics, and (4) phosphate binders, may instead have the opposite effects on vitamin K metabolism and storage in CKD patients

Balanced Paths in Colored Graphs

Abstract. We consider finite graphs whose edges are labeled with elements, called colors, taken from a fixed finite alphabet. We study the problem of determining whether there is an infinite path where either (i) all colors occur with the same asymptotic frequency, or (ii) there is a constant which bounds the difference between the occurrences of any two colors for all prefixes of the path. These two notions can be viewed as refinements of the classical notion of fair path, whose simplest form checks whether all colors occur infinitely often. Our notions provide stronger criteria, particularly suitable for scheduling applications based on a coarse-grained model of the jobs involved. We show that both problems are solvable in polynomial time, by reducing them to the feasibility of a linear program.

Modifying exchange bias effects of Mn/NiFe bilayers by in-situ Ar+ bombardment

In this work, we present a procedure to modify the exchange bias (EB) properties of antiferromagnetic Mn/ferromagnetic NiFe bilayers by in-situ low energy Ar+ bombardment of the Mn layer during sample deposition. We present structural and magnetic results for unassisted and Ar+ assisted Mn/NiFe bilayers. X-ray diffraction, transmission electron microscopy and electron diffraction results establish different preferred Mn orientation directions between the two samples as a result of the Ar+ bombardment process. Hysteresis loops taken over several temperatures reveal that samples assisted with Ar+ ions during the Mn layer deposition had suppressed EB properties at low temperature as compared to samples grown without Ar+ assistance

Nephrological Indications in Combined Liver-Kidney Transplantation

In isolated liver transplantation pretransplant renal failure is a major mortality risk, there are no guidelines at the moment to establish the indications for a combined liver-kidney transplantation (LKT). In irreversible chronic renal failure (CRF) not on dialysis, nephrological evaluation is required to assess the need for a simultaneous kidney transplantation. There are no experiences about the functional contribution of native kidneys post-LKT. Herein we have reported the case of two patients who underwent LKT in 2004 due to CRF, not yet on dialysis. At the moment of LKT, the first patient (polycystic kidney disease) had a glomerular filtration rate (GFR) = 29 mL/min, and the second recipient (vascular nephropathy and diabetes), a GFR = 33 mL/min. In both cases we did not observe delayed graft function. At discharge the serum creatinine was 1.1 and 1.0 mg/dL, respectively, which was maintained during follow-up. In both cases renal scintigraphy with Tc-99 DMSA was performed to evaluate the functional contributions of transplanted versus native kidneys. In the first case scintigraphy at 9 months after LKT demonstrated an 81% contribution from the transplanted kidney, 9% from the right and 10% from the left native kidneys. In the second case, at 3 months after LKT, the functional contributions were 76%, 10%, and 14%, respectively. The transplanted kidney nephron mass may avoid the need for hemodialysis in the early posttransplant period; in the midterm it may help to maintain residual renal function. As in other combined transplant programs (heart-kidney, kidney-pancreas) with irreversible CRF, a GFR 64 30 to 35 mL/min may be an indication for LKT, but we need more experience