Evaluation of a novel mitochondria‐targeted anti-­oxidant therapy for ischaemia-­reperfusion injury in renal transplantation

Ischaemia-reperfusion (IR) injury makes a major contribution to graft damage during kidney transplantation and increases the risks of primary non-function, delayed graft function and rejection. Oxidative damage to mitochondria is a key early event in IR injury. The aim of this project was to examine the safety and efficacy of the mitochondria-targeted antioxidant MitoQ in reducing pig and human kidney IR injury using an ex vivo normothermic perfusion (EVNP) system. Over a range of 500 nM to 250 µM using a 150 pig kidneys and 80 declined deceased human kidneys, MitoQ was successfully taken up by pig and human kidneys in a concentration-dependent manner, resulting in stable tissue concentrations over 24 hours of cold storage followed by 6 hours of EVNP. The uptake of MitoQ was increased approximately 2-fold when MitoQ was administered to warm (rather than cold) kidneys and when kidneys were preserved using hypothermic machine perfusion (rather than cold static storage). 50 µM MitoQ, administered to pig kidneys at the end of warm ischaemia, significantly increased renal blood and urine output flow at the end of 6 h EVNP compared to the control group. Creatinine clearance was numerically higher in the 50 µM MitoQ group compared to the control group but the difference did not reach statistical significance. To test the safety and efficacy of MitoQ in human kidney IRI, pairs of declined deceased human kidneys were used, with one kidney in each pair used as control. The total urine output, creatinine clearance and percentage fall of serum creatinine were numerically higher in the 50 µM MitoQ group compared to the control group, although the differences did not reach statistical significance during 3 h of EVNP. There was a significant difference in the renal blood flow between the 50 µM MitoQ group and the control group at the end of the first hour of EVNP. The renal blood flow remained relatively stable during the first hour of EVNP in the 50 µM MitoQ group compared to a significant decrease in renal blood flow in the control group. There was no effect on fractional excretion of sodium or oxidative injury markers (protein carbonyl formation, lipid peroxidation) in pig or human kidneys, which is consistent with previous studies that demonstrated the requirement of >24 hour after reperfusion for manifestation of changes in these parameters. In this thesis, I was able to successfully demonstrate the safety and potential efficacy of MitoQ in ameliorating renal IRI using pig kidneys. While more declined deceased human kidneys need to be analysed to fully explore the potential efficacy of MitoQ in ameliorating renal IRI, this study provides important data that will help inform future studies and ultimately a clinical trial for assessing the efficacy of the mitochondria-targeted antioxidant MitoQ in human kidney transplantation. My findings suggest that MitoQ has the potential to increase the use of marginal kidneys and to improve graft and patient outcomes.Research grant 2014-2016 Evelyn trust grant - Evaluation of a novel mitochondria-targeted anti-oxidant therapy for delayed graft function in renal transplantation. Total: £168,00

Development of an objective, standardized tool for surgical assessment of deceased donor kidneys: the Cambridge Kidney Assessment Tool

Quality assessment in kidney transplantation involves inspection to identify negative markers of organ quality. However, there is a paucity of evidence guiding surgical appraisal, and currently there is no evidence to differentiate important features from those that can be safely ignored. We propose a method to standardize surgical assessment and derived a simple rule to rapidly identify kidneys suitable for transplantation. Donor and recipient data were recorded alongside clinical outcomes in a prospectively maintained database. We developed a proforma (Cambridge Kidney Assessment Tool, CKAT) and used it to assess deceased donor kidney transplants. Factors predictive of utilization were identified by multivariate and univariate logistic regression analysis of CKAT-assessment scores, and test performance was evaluated using standard 2 × 2 contingency tables. Ninety-seven kidneys were included at a single center (2013-2014), and 184 CKAT assessments were performed. A CKAT threshold of “Carrell + Perfusion >3” was highly specific (99%) and performed favorably to consultant opinion (specificity 95%). 96% of the kidneys implanted in accordance with the rule survived to 1 year (mean eGFR 45.3 mL/min/1.73 m2). To our knowledge, this is the first attempt to objectively define macroscopic features that are relevant to kidney utilization. Common language could support training in organ assessment and ultimately help address unnecessary discard of donor kidneys

CLINICAL AND TYMPANOMETRIC ASSESSMENT OF MIDDLE EAR EFFUSION VERSUS MYRINGOTOMY FINDING

Background: The present study was planned to show the accuracy of clinical examination and tympanometry in diagnosis of middle ear effusion. Patients and Methods: The study involved 80 patients (160 ears )suspected to have otitis media with effusion (OME) from different age groups ; 56 were males and 24 were females . Clinical assessment for all patients included otoscopy , pneumatic otoscopy and audiological assessment by using pure tone audiometry and tympanometry then comparing the results to findings at myringotomy as the gold standard for presence or absence of fluid in the middle ear. Results : Fluid whether serous or glue was found in 100 ears ( 62.5 %) where as sixty ears were dry, sensitivity , specificity and accuracy of tympanometry were 90 % , 70 % and 85 % respectively , and for clinical assessment were 82 % , 52% and 71 % respectively . A combined clinical and tympanometry sensitivity and specificity were calculated and found to be 96 % and 92 % respectively. Conclusion : clinical examination as a method for diagnosis of middle ear effusion depend on experience of the examiner . tympanometry proved to be a reliable diagnostic tool for the diagnosis of OME , it appeared significantly better at determining non effusion state

Normothermic perfusion in the assessment and preservation of declined livers prior to transplantation: hyperoxia and vasoplegia - important lessons from the first 12 cases.

BACKGROUND: A programme of normothermic ex situ liver perfusion (NESLiP) was developed to facilitate better assessment and use of marginal livers, while minimising cold ischaemia. METHODS: Declined marginal livers and those offered for research were evaluated. NESLiP was performed using an erythrocyte-based perfusate. Viability was assessed with reference to biochemical changes in the perfusate. RESULTS: 12 livers (9 from circulatory death (DCD) and 3 from brain-dead donors), median Donor Risk Index 2.15, were subjected to NESLiP for a median 284 minutes (range 122-530) after an initial cold storage period of 427 minutes (range 222-877). The first 6 livers were perfused at high perfusate oxygen tensions, and the subsequent 6 at near-physiologic oxygen tensions. After transplantation, 5 of the first 6 recipients developed postreperfusion syndrome and 4 had sustained vasoplegia; 1 recipient experienced primary nonfunction in conjunction with a difficult explant. The subsequent 6 liver transplants, with livers perfused at lower oxygen tensions, reperfused uneventfully. Three DCD liver recipients developed cholangiopathy, and this was associated with an inability to produce an alkali bile during NESLiP. CONCLUSIONS: NESLiP enabled assessment and transplantation of 12 livers that may otherwise not have been used. Avoidance of hyperoxia during perfusion may prevent postreperfusion syndrome and vasoplegia, and monitoring biliary pH, rather than absolute bile production, may be important in determining the likelihood of posttransplant cholangiopathy. NESLiP has the potential to increase liver utilization, but more work is required to define factors predicting good outcomes.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Solving vehicle routing problem by using improved K-nearest neighbor algorithm for best solution

Vehicle routing problem (VRP) is one of the many difficult issues that have no perfect solutions yet. Many researchers over the last few decades have established numerous researches and used many methods with different techniques to handle it. But, for all research, finding the lowest cost is very complex. However, they have managed to come up with approximate solutions that differ in efficiencies depending on the search space. Problem: In this study the problem is as follows: have a number of vehicles which are used for transporting applications to instance place. Each vehicle starts from a main location at different times every day. The vehicle picks up applications from start locations to the instance place in many different routes and return back to the start location in at specific times every day, starting from early morning until the end of official working hours, on the following conditions: (1) Every location will be visited once in each route, and (2) The capacity of each vehicle is enough for all applications included in each route. Objectives: Our paper attempt to find an optimal route result for VRP by using K-Nearest Neighbor Algorithm (KNNA). To achieve an optimal solution for VRP with the accompanying targets: (1) To reduce the distance and the time for all paths this leads to speedy the transportation of customers to their locations, (2) To implement the capacitated vehicle routing problem (CVRP) model for optimizing the solutions. Approach: The approach has been presented based on two phases: firstly, the algorithms have been adapted to solve the research problem, where its procedure is different than the common algorithm. The structure of the algorithm is designed so that the program does not require a large database to store the population, which speeds up the implementation of the program execution to obtain the solution; secondly, the algorithm has proven its success in solving the problem and finds a shortest route. For the purpose of testing the algorithm’s capability and reliability, it was applied to solve the same problem online validated and it achieved success in finding a shorter route. Finding: The findings outcome from this study have shown that: (1) A universal listed of dynamic KNNACVRP; (2) Identified and built up an assessment measure for KNNACVRP; (3) Highlight the strategies, based KNNA operations, for choosing the most ideal way (4) KNNA finds a shorter route for VRP paths. The extent of lessening the distance for each route is generally short, but the savings in the distance becomes more noteworthy while figuring the aggregate distances traveled by all transports day by day or month to month. This applies likewise to the time calculate that has been decreased marginally in view of the rate of reduction in the distances of the paths

Normothermic Perfusion in the Assessment and Preservation of Declined Livers Before Transplantation: Hyperoxia and Vasoplegia-Important Lessons From the First 12 Cases.

BACKGROUND: A program of normothermic ex situ liver perfusion (NESLiP) was developed to facilitate better assessment and use of marginal livers, while minimizing cold ischemia. METHODS: Declined marginal livers and those offered for research were evaluated. Normothermic ex situ liver perfusion was performed using an erythrocyte-based perfusate. Viability was assessed with reference to biochemical changes in the perfusate. RESULTS: Twelve livers (9 donation after circulatory death [DCD] and 3 from brain-dead donors), median Donor Risk Index 2.15, were subjected to NESLiP for a median 284 minutes (range, 122-530 minutes) after an initial cold storage period of 427 minutes (range, 222-877 minutes). The first 6 livers were perfused at high perfusate oxygen tensions, and the subsequent 6 at near-physiologic oxygen tensions. After transplantation, 5 of the first 6 recipients developed postreperfusion syndrome and 4 had sustained vasoplegia; 1 recipient experienced primary nonfunction in conjunction with a difficult explant. The subsequent 6 liver transplants, with livers perfused at lower oxygen tensions, reperfused uneventfully. Three DCD liver recipients developed cholangiopathy, and this was associated with an inability to produce an alkali bile during NESLiP. CONCLUSIONS: Normothermic ex situ liver perfusion enabled assessment and transplantation of 12 livers that may otherwise not have been used. Avoidance of hyperoxia during perfusion may prevent postreperfusion syndrome and vasoplegia, and monitoring biliary pH, rather than absolute bile production, may be important in determining the likelihood of posttransplant cholangiopathy. Normothermic ex situ liver perfusion has the potential to increase liver utilization, but more work is required to define factors predicting good outcomes

Succinate accumulation drives ischaemia-reperfusion injury during organ transplantation.

During heart transplantation, storage in cold preservation solution is thought to protect the organ by slowing metabolism; by providing osmotic support; and by minimising ischaemia-reperfusion (IR) injury upon transplantation into the recipient1,2. Despite its widespread use our understanding of the metabolic changes prevented by cold storage and how warm ischaemia leads to damage is surprisingly poor. Here, we compare the metabolic changes during warm ischaemia (WI) and cold ischaemia (CI) in hearts from mouse, pig, and human. We identify common metabolic alterations during WI and those affected by CI, thereby elucidating mechanisms underlying the benefits of CI, and how WI causes damage. Succinate accumulation is a major feature within ischaemic hearts across species, and CI slows succinate generation, thereby reducing tissue damage upon reperfusion caused by the production of mitochondrial reactive oxygen species (ROS)3,4. Importantly, the inevitable periods of WI during organ procurement lead to the accumulation of damaging levels of succinate during transplantation, despite cooling organs as rapidly as possible. This damage is ameliorated by metabolic inhibitors that prevent succinate accumulation and oxidation. Our findings suggest how WI and CI contribute to transplant outcome and indicate new therapies for improving the quality of transplanted organs.Work in the M.P.M. laboratory was supported by the Medical Research Council UK (MC_U105663142) and by a Wellcome Trust Investigator award (110159/Z/15/Z) to M.P.M. Work in the C.F. laboratory was supported by the Medical Research Council (MRC_MC_UU_12022/6). Work in the K.S.P. laboratory was supported by the Medical Research Council UK. Work in the RCH lab laboratory was supported by a Wellcome Trust Investigator award (110158/Z/15/Z) and a PhD studentship for .L.P from the University of Glasgow. A.V.G. was supported by a PhD studentship funded by the National Institute for Health Research Blood and Transplant Research Unit (NIHR BTRU) in Organ Donation and Transplantation at the University of Cambridge in collaboration with Newcastle University and in partnership with NHS Blood and Transplant (NHSBT)

Targeting succinate dehydrogenase with malonate ester prodrugs decreases renal ischemia reperfusion injury

Renal ischemia reperfusion (IR) injury leads to significant patient morbidity and mortality, and its amelioration is an urgent unmet clinical need. Succinate accumulates during ischemia and its oxidation by the mitochondrial enzyme succinate dehydrogenase (SDH) drives the ROS production that underlies IR injury. Consequently, compounds that inhibit SDH may have therapeutic potential against renal IR injury. Among these, the competitive SDH inhibitor malonate, administered as a cell-permeable malonate ester prodrug, has shown promise in models of cardiac IR injury, but the efficacy of malonate ester prodrugs against renal IR injury have not been investigated. Here we show that succinate accumulates during ischemia in mouse, pig and human models of renal IR injury, and that its rapid oxidation by SDH upon reperfusion drives IR injury. We then show that the malonate ester prodrug, dimethyl malonate (DMM), can ameliorate renal IR injury when administered at reperfusion but not prior to ischemia in the mouse. Finally, we show that another malonate ester prodrug, diacetoxymethyl malonate (MAM), is more potent than DMM because of its faster esterase hydrolysis. Our data show that the mitochondrial mechanisms of renal IR injury are conserved in the mouse, pig and human and that inhibition of SDH by ‘tuned’ malonate ester prodrugs, such as MAM, is a promising therapeutic strategy in the treatment of clinical renal IR injury

Review On Nasopharyngeal Carcinoma: Concepts, Methods Of Analysis, Segmentation, Classification, Prediction And Impact: A Review Of The Research Literature

Context: Nasopharyngeal Carcinoma (NPC) is the most famous type of tumor in the neck and started in the nasopharynx, the area at the top of the pharynx or “throat”, in which the participation of the relevant nose and tube sound including all upper respiratory tract. Purpose: The study is a reviewed literature on NPC Diagnosis. The objectives of the paper are to under-stand; (1) The conceptual definitions of Nasopharyngeal Carcinoma, (2) the descriptive nature of the structure of the prediction NPC, (3) The contextual usage of NPC, (4) who have access to the NPC, (5)the nature and components of the data used in NPC study, (6) what are the objectives of this field of research (7) what data collection techniques were employed in the previous researches (8) what were the outcome of the previous studies. Methodology: Until this time no systematic literature reviews (SLR) were conducted on NPC based on Segmentation, Classification, and Prediction. The aim of the study therefore, is to conduct a systematic review, classification and comparison of the previous methodology and approaches used in the studies on Nasopharyngeal Carcinoma based on Segmentation, Classification, and Prediction composition (published between 1970 and 2016). We therefore systematically reviewed available researches related to the NPC. We search for available literature using five electronics databases: ScienceDirect.com | Science, health and medical journals, IEEE – The world’s largest technical & professional organization, Springer –International Publisher Science, Technology, Medicine, ACM digital libraries and Google Scholar. Results: The concept of NPC encompasses vast information technologies, there are few papers that dwelt on explanations on the NPC structure or the terminology used, synopsis on the various methods and technologies involved in NPC, the contents of NPC, The various findings on NPC developmental work, Data Analysis, Segmentation, Classification, Prediction and Impacts of Nasopharyngeal Carcinoma. In this study, offered an explanation for NPC defined, how structure prediction Nasopharyngeal Carcinoma described, in what context NPC used, who has access to the NPC, the component data of the NPC used and studied, what is the purpose of research in this field, what methods of data collection was used in the review and whether the results of this study. Also an impression of all the several of methods and technologies involved in NPC, A synopsis of the details of NPC and the result that in NPC development work, segmentation of NPC, NPC diagnoses or the prognosis process