or living) adj5 (donor or donation)).ti,ab. 18. or/13-17 19. 12 or 18 20. (("cell-free" or "cell free" or "cf" or circulating or serum or plasma or mitochondrial) adj5 (DNA or "Deoxyribonucleic acid" or "nucleic acid$")).ti,ab. 21. ("cf-dna" or "cf dna" or "cfNDA" or "mtDNA" or "mt DNA" or "mt-DNA").ti,ab. 22. DNA/blood* 23. or/20-22 24. 19 and 23

Transportable normothermic kidney perfusion for 24 hours or longer could enable viability assessment of marginal grafts, increased organ use, and improved transplant logistics. Eleven clinically declined kidneys were perfused normothermically, with 6 being from donors after brain death (median cold ischemia time 33 ± 36.9 hours) and 5 being from donors after circulatory death (36.2 ± 38.3 hours). Three kidneys were perfused using Ringer's lactate to replace excreted urine volume, and 8 kidneys were perfused using urine recirculation to maintain perfusate volume without fluid replenishment. In all cases, normothermic perfusion either maintained or slightly improved the histopathologically assessed tubular condition, and there was effective urine production in kidneys from both donors after brain death and donors after circulatory death (2367 ± 1798 mL vs 744.4 ± 198.4 mL, respectively; P = .44). Biomarkers, neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 were successfully detected and quantified in the perfusate. All kidneys with urine recirculation were readily perfused for 24 hours (n = 8) and exhibited physiological perfusate sodium levels (140.7 ± 1.2 mmol/L), while kidneys without urine recirculation (n = 3) achieved a reduced normothermic perfusion time of 7.7 ± 1.5 hours and significantly higher perfusate sodium levels (159.6 ± 4.63 mmol/:, P < .01). Normothermic machine perfusion of human kidneys for 24 hours appears to be feasible, and urine recirculation was found to facilitate the maintenance of perfusate volume and homeostasis.

No abstract

Reactive species of oxygen, nitrogen and sulfur play cell signalling roles in human health, e.g. recent studies have shown that increased dietary nitrate, which is a source of RNS (reactive nitrogen species), lowers resting blood pressure and the oxygen cost of exercise. In such studies, plasma nitrite and nitrate are readily determined by chemiluminescence. At sites of inflammation, such as the joints of RA (rheumatoid arthritis) patients, the generation of ROS (reactive oxygen species) and RNS overwhelms antioxidant defences and one consequence is oxidative/nitrative damage to proteins. For example, in the inflamed joint, increased RNS-mediated protein damage has been detected in the form of a biomarker, 3-nitrotyrosine, by immunohistochemistry, Western blotting, ELISAs and MS. In addition to NO•, another cell-signalling gas produced in the inflamed joint is H2S (hydrogen sulfide), an RSS (reactive sulfur species). This gas is generated by inflammatory induction of H2S-synthesizing enzymes. Using zinc-trap spectrophotometry, we detected high (micromolar) concentrations of H2S in RA synovial fluid and levels correlated with clinical scores of inflammation and disease activity. What might be the consequences of the inflammatory generation of reactive species? Effects on inflammatory cell-signalling pathways certainly appear to be crucial, but in the current review we highlight the concept that ROS/RNS-mediated protein damage creates neoepitopes, resulting in autoantibody formation against proteins, e.g. type-II collagen and the complement component, C1q. These autoantibodies have been detected in inflammatory autoimmune diseases.

Ischaemia and reperfusion injury (IRI) is the leading cause of acute kidney injury (AKI), which contributes to high morbidity and mortality rates in a wide range of injuries as well as the development of chronic kidney disease. The cellular and molecular responses of the kidney to IRI are complex and not fully understood. Here, we used an integrated proteomic and metabolomic approach to investigate the effects of IRI on protein abundance and metabolite levels. Rat kidneys were subjected to 45 min of warm ischaemia followed by 4 h and 24 h reperfusion, with contralateral and separate healthy kidneys serving as controls. Kidney tissue proteomics after IRI revealed elevated proteins belonging to the acute phase response, coagulation and complement pathways, and fatty acid (FA) signalling. Metabolic changes were already evident after 4 h reperfusion and showed increased level of glycolysis, lipids and FAs, whilst mitochondrial function and ATP production was impaired after 24 h. This deficit was partially compensated for by the contralateral kidney. Such a metabolic balance counteracts for the developing energy deficit due to reduced mitochondrial function in the injured kidney.

No abstract

Normothermic machine perfusion (NMP) of injured kidneys offers the opportunity for interventions to metabolically active organs prior to transplantation. Mesenchymal stromal cells (MSCs) can exert regenerative and anti‐inflammatory effects in ischemia‐reperfusion injury. The aims of this study were to evaluate the safety and feasibility of MSC treatment of kidneys during NMP using a porcine autotransplantation model, and examine potential MSC treatment‐associated kidney improvements up to 14 days posttransplant. After 75 min of kidney warm ischemia, four experimental groups of n = 7 underwent 14 h of oxygenated hypothermic machine perfusion. In three groups this was followed by 240 min of NMP with infusion of vehicle, 10 million porcine, or 10 million human adipose‐derived MSCs. All kidneys were autotransplanted after contralateral nephrectomy. MSC treatment did not affect perfusion hemodynamics during NMP or cause adverse effects at reperfusion, with 100% animal survival. MSCs did not affect plasma creatinine, glomerular filtration rate, neutrophil gelatinase‐associated lipocalin concentrations or kidney damage assessed by histology during the 14 days, and MSCs retention was demonstrated in renal cortex. Infusing MSCs during ex vivo NMP of porcine kidneys was safe and feasible. Within the short posttransplant follow‐up period, no beneficial effects of ex vivo MSC therapy could be demonstrated.

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