scholarly journals “Old School” Islet Purification Based on the Unit Gravity Sedimentation as a Rescue Technique for Intraportal Islet Transplantation—A Case Report

2020 ◽  
Vol 29 ◽  
pp. 096368972094709
Author(s):  
Justyna E. Gołębiewska ◽  
Karolina Gołąb ◽  
Tomasz Gorycki ◽  
Maciej Śledziński ◽  
Jacek Gulczyński ◽  
...  
Keyword(s):  
Gradient Centrifugation ◽  
Portal Pressure ◽  
Graft Function ◽  
Post Transplantation ◽  
Subcutaneous Injections ◽  
Insulin Requirements ◽  
Male Donor ◽  
Gravity Sedimentation ◽  
Unit Gravity Sedimentation ◽  
Target Glucose

Here, we present a case that required a supplemental “old school” islet purification for a safe intraportal infusion. Following pancreas procurement from a brain-dead 26-year-old male donor (body mass index: 21.9), 24.6 ml of islet tissue was isolated after continuous density gradient centrifugation. The islet yield was 504,000 islet equivalent (IEQ), distributed among the following three fractions: 64,161 IEQ in 0.6 ml of pellet, 182,058 IEQ in 10 ml, and 258,010 IEQ in 14 ml with 95%, 20%, and 10% purity, respectively. After a 23-h culture, we applied supplemental islet purification, based on the separation of tissue subfractions during unit gravity sedimentation, a technique developed over 60 years ago (“old school”). This method enabled the reduction of the total pellet volume to 11.6 ml, while retaining 374,940 IEQ with a viability of over 90%. The final islet product was prepared in three infusion bags, containing 130,926 IEQ in 2.6 ml of pellet, 108,079 IEQ in 4 ml of pellet, and 135,935 IEQ in 5 ml of pellet with 65%, 40%, and 30% purity, respectively, and with the addition of unfractionated heparin (70 units/kg body weight). Upon the islet infusion from all three bags, portal pressure increased from 7 to 16 mmHg. Antithrombotic prophylaxis with heparin was continued for 48 h after the infusion, with target activated partial thromboplastin time 50–60 s, followed by fractionated heparin subcutaneous injections for 2 weeks. β-Cell graft function assessed on day 75 post-transplantation was good, according to Igls criteria, with complete elimination of severe hypoglycemic episodes and 50% reduction in insulin requirements. Time spent within the target glucose range (70–180 mg/dl) improved from 42% to 98% and HbA1c declined from 8.7% to 6.7%. Supplemental “old school” islet purification allowed for the safe and successful utilization of a robust and high-quality islet preparation, which otherwise would have been discarded.

scholarly journals The future is coming: promising perspectives regarding the use of machine learning in renal transplantation

2019 ◽  
Vol 41 (2) ◽  
pp. 284-287
Author(s):  
Pedro Guilherme Coelho Hannun ◽  
Luis Gustavo Modelli de Andrade
Keyword(s):  
Machine Learning ◽  
Prediction Models ◽  
Graft Function ◽  
Statistical Technique ◽  
Daily Routine ◽  
Learning Approaches ◽  
Post Transplantation ◽  
Chronic Allograft Rejection ◽  
Institutional Experience ◽  
Learning Principles

Abstract Introduction: The prediction of post transplantation outcomes is clinically important and involves several problems. The current prediction models based on standard statistics are very complex, difficult to validate and do not provide accurate prediction. Machine learning, a statistical technique that allows the computer to make future predictions using previous experiences, is beginning to be used in order to solve these issues. In the field of kidney transplantation, computational forecasting use has been reported in prediction of chronic allograft rejection, delayed graft function, and graft survival. This paper describes machine learning principles and steps to make a prediction and performs a brief analysis of the most recent applications of its application in literature. Discussion: There is compelling evidence that machine learning approaches based on donor and recipient data are better in providing improved prognosis of graft outcomes than traditional analysis. The immediate expectations that emerge from this new prediction modelling technique are that it will generate better clinical decisions based on dynamic and local practice data and optimize organ allocation as well as post transplantation care management. Despite the promising results, there is no substantial number of studies yet to determine feasibility of its application in a clinical setting. Conclusion: The way we deal with storage data in electronic health records will radically change in the coming years and machine learning will be part of clinical daily routine, whether to predict clinical outcomes or suggest diagnosis based on institutional experience.

scholarly journals B-cell activating factor BAFF as a novel alert marker for the immunological risk stratification after kidney transplantation

2021 ◽  
Author(s):  
Antonia Margarete Schuster ◽  
N. Miesgang ◽  
L. Steines ◽  
C. Bach ◽  
B. Banas ◽  
...  
Keyword(s):  
Kidney Transplantation ◽  
B Cell ◽  
Graft Function ◽  
Risk Profile ◽  
Kidney Transplant Recipients ◽  
Post Transplantation ◽  
Antibody Mediated Rejection ◽  
B Cell Activating Factor ◽  
Medium Risk ◽  
Patients At Risk

AbstractThe B cell activating factor BAFF has gained importance in the context of kidney transplantation due to its role in B cell survival. Studies have shown that BAFF correlates with an increased incidence of antibody-mediated rejection and the development of donor-specific antibodies. In this study, we analyzed a defined cohort of kidney transplant recipients who were treated with standardized immunosuppressive regimens according to their immunological risk profile. The aim was to add BAFF as an awareness marker in the course after transplantation to consider patient’s individual immunological risk profile. Included patients were transplanted between 2016 and 2018. Baseline data, graft function, the occurrence of rejection episodes, signs of microvascular infiltration, and DSA kinetics were recorded over 3 years. BAFF levels were determined 14 d, 3 and 12 months post transplantation. Although no difference in graft function could be observed, medium-risk patients showed a clear dynamic in their BAFF levels with low levels shortly after transplantation and an increase in values of 123% over the course of 1 year. Patients with high BAFF values were more susceptible to rejection, especially antibody-mediated rejection and displayed intensified microvascular inflammation; the combination of high BAFF + DSA puts patients at risk. The changing BAFF kinetics of the medium risk group as well as the increased occurrence of rejections at high BAFF values enables BAFF to be seen as an awareness factor. To compensate the changing immunological risk, a switch from a weaker induction therapy to an intensified maintenance therapy is required.

Low Graft Function and Ongoing Hyperparathyroidism Are Closely Related to Post-Transplantation Osteoporosis

2013 ◽  
Vol 45 (4) ◽  
pp. 1562-1566 ◽  
Author(s):  
E. Tutal ◽  
M.E. Uyar ◽  
T. Colak ◽  
Z. Bal ◽  
B.G. Demirci ◽  
...  
Keyword(s):  
Graft Function ◽  
Post Transplantation

Purification of dispersed rat adrenal zona glomerulosa cells by Percoll density gradient centrifugation and the isolation of a population of cells highly responsive to adrenocorticotrophin

1986 ◽  
Vol 109 (3) ◽  
pp. 351-NP ◽  
Author(s):  
F. W. Chu ◽  
P. J. Hyatt
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Zona Glomerulosa ◽  
Zona Fasciculata ◽  
Sephadex Column ◽  
Percoll Density Gradient Centrifugation ◽  
Percoll Density Gradient ◽  
Glomerulosa Cells ◽  
Unit Gravity Sedimentation

ABSTRACT Percoll density gradient centrifugation is a simple, inexpensive and convenient method to eliminate contaminating zona fasciculata (ZF) cells from unpurified rat adrenal capsular glomerulosa (ZG) cell preparations (with less than 0·1% ZF cells in the final cell preparation). Basal steroid (aldosterone and corticosterone) output by the purified (PG) cells was unchanged. These purified cells, although free from ZF contamination, were more highly responsive than expected to ACTH (3 nmol/l). When PG cells were further separated by Sephadex column filtration, the filtered PG cells exhibited the steroidogenic response of ZG cells purified by unit gravity sedimentation and Sephadex column filtration, i.e. reduced basal steroid output and an ACTH response reduced to that stimulated by K+ (8·4 mmol/l). Although the cells retained in the column resembled the filtered PG cells ultrastructurally, they showed unchanged basal steroid output and a high ACTH response with increased latepathway activity (the conversion of corticosterone to aldosterone). By combining Percoll density gradient centrifugation and Sephadex column filtration we have a method for the isolation and study of both the high-and low-response rat ZG cells which are free from ZF contamination. J. Endocr. (1986) 109, 351–358

scholarly journals Separation of Erythropoietin-sensitive Cells From Hemopoietic Spleen Colony-forming Stem Cells of Mouse Fetal Liver by Unit Gravity Sedimentation

Blood ◽  
1971 ◽  
Vol 37 (4) ◽  
pp. 417-427 ◽  
Author(s):  
JOHN R. STEPHENSON ◽  
ARTHUR A. AXELRAD
Keyword(s):  
Stem Cells ◽  
Present Method ◽  
Fetal Liver ◽  
Sedimentation Velocity ◽  
Assay Method ◽  
Fetal Liver Cells ◽  
Gravity Sedimentation ◽  
Cell Fractions ◽  
Unit Gravity Sedimentation

Abstract An assay method for erythropoietin-sensitive cells has been developed based on the fact that cells of mouse fetal liver respond to erythropoietin in vitro by increased heme synthesis. To determine whether or not hemopoietic colony-forming stem cells are identical with erythropoietin-sensitive cells, C3H/Bi 13-day fetal liver cells were separated into fractions on the basis of size by unit gravity sedimentation through a 1-2 per cent bovine serum albumin gradient. The cell fractions obtained were assayed for erythropoietin-sensitive cells by the present method and for spleen colony-forming cells by the method of Till and McCulloch. It was found that the modal sedimentation velocity of erythropoietin-sensitive cells was greater than that of the spleen colony-forming cells of mouse fetal liver, showing that these two classes of cells are distinct.

Hypoxic preconditioning in renal ischaemia–reperfusion injury: a review in pre-clinical models

2021 ◽  
Vol 135 (23) ◽  
pp. 2607-2618
Author(s):  
Laurie Bruzzese ◽  
Gwénaël Lumet ◽  
Donato Vairo ◽  
Claire Guiol ◽  
Régis Guieu ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Potential Benefit ◽  
Graft Function ◽  
Major Complication ◽  
Hypoxic Preconditioning ◽  
Cellular Damage ◽  
Post Transplantation ◽  
Ischaemia Reperfusion Injury ◽  
Ischaemia Reperfusion ◽  
Clinical Models

Abstract Ischaemia–reperfusion injury (IRI) is a major cause of acute kidney injury (AKI) and chronic kidney disease, which consists of cellular damage and renal dysfunction. AKI is a major complication that is of particular concern after cardiac surgery and to a lesser degree following organ transplantation in the immediate post-transplantation period, leading to delayed graft function. Because effective therapies are still unavailable, several recent studies have explored the potential benefit of hypoxic preconditioning (HPC) on IRI. HPC refers to the acquisition of increased organ tolerance to subsequent ischaemic or severe hypoxic injury, and experimental evidences suggest a potential benefit of HPC. There are three experimental forms of HPC, and, for better clarity, we named them as follows: physical HPC, HPC via treated-cell administration and stabilised hypoxia-inducible factor (HIF)-1α HPC, or mimicked HPC. The purpose of this review is to present the latest developments in the literature on HPC in the context of renal IRI in pre-clinical models. The data we compiled suggest that preconditional activation of hypoxia pathways protects against renal IRI, suggesting that HPC could be used in the treatment of renal IRI in transplantation.

scholarly journals Effects of body weight variation in obese kidney recipients: a retrospective cohort study

2019 ◽  
Vol 13 (6) ◽  
pp. 1068-1076 ◽  
Author(s):  
Nuria Montero ◽  
Maria Quero ◽  
Emma Arcos ◽  
Jordi Comas ◽  
Inés Rama ◽  
...  
Keyword(s):  
Body Weight ◽  
Graft Survival ◽  
Graft Function ◽  
Obese Patients ◽  
Weight Changes ◽  
Kidney Transplant Recipients ◽  
Post Transplantation ◽  
Kidney Recipients ◽  
Weight Variation

Abstract Background Obese kidney allograft recipients have worse results in kidney transplantation (KT). However, there is lack of information regarding the effect of body mass index (BMI) variation after KT. The objective of the study was to evaluate the effects of body weight changes in obese kidney transplant recipients. Methods In this study we used data from the Catalan Renal Registry that included KT recipients from 1990 to 2011 (n = 5607). The annual change in post-transplantation BMI was calculated. The main outcome variables were delayed graft function (DGF), estimated glomerular filtration rate (eGFR) and patient and graft survival. Results Obesity was observed in 609 patients (10.9%) at the time of transplantation. The incidence of DGF was significantly higher in obese patients (40.4% versus 28.3%; P < 0.001). Baseline obesity was significantly associated with worse short- and long-term graft survival (P < 0.05) and worse graft function during the follow-up (P < 0.005). BMI variations in obese patients did not improve eGFR or graft or patient survival. Conclusions Our conclusion is that in obese patients, decreasing body weight after KT does not improve either short-term graft outcomes or long-term renal function.

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