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A new scheme of a control-beam-driven nonlinear optical loop mirror (NOLM) with a birefringent twisted fiber and a symmetrical coupler designed for optical time division demultiplexing (OTDM) is analyzed. The theoretical model of the proposed NOLM scheme considers the evolution of polarization states of data and control beams and the mutual interactions of the data and control beams due to the cross-phase modulation (XPM). Attention is given to the optical switching commanded by the control-beam power and by the manipulation of nonlinear polarization rotation of the data and control beam. The simulations of NOLM transmissions demonstrate that the cross talk between demultiplexed and nondemultiplexed beams as an important parameter for optical switching by the presented NOLM can be significantly reduced. The results show that the device can be of interest for all-optical signal manipulations in optical communication networks. [ABSTRACT FROM AUTHOR]

Abstract Objective There are no specific recommendations for therapeutic plasma exchange (TPE) in children after renal transplantation. The purpose of this study was to report the experience with TPE in a pediatric transplant setting. Materials and Methods 59 patients (mean age 12.5 ± 4.5 years) undergoing renal transplantation. Indications for TPE included the recurrence of nephrotic syndrome (NS; n = 30) and atypical hemolytic uremic syndrome (n = 6), chronic antibody-mediated rejection (cAMR; n = 20), sensitization (n = 2), and immune thrombocytopenia (n = 1). The single-filtration TPE was performed in all cases. In 74.7% of patients, fresh frozen plasma was used as a replacement fluid. In 25.3% of patients, 4% albumin solution was used as a replacement fluid. Criteria for TPE efficacy included a decrease of proteinuria and normalization of renal function in NS; a normalization of platelet count, C3, and hemoglobin concentration in aHUS; improvement in renal function; and reduction of donor-specific antibodies in cAMR; and removal of antiplatelet antibodies in immune thrombocytopenia. Results Efficacy results for patients with NS: 59.3% achieved remission, 25.9% achieved partial remission, and 14.8% achieved no remission, respectively. For patients with atypical hemolytic uremic syndrome there was remission in 66.6% and no remission in 33.4%. For patients with cAMR there was remission in 75% and no remission in 25%. Antiplatelet antibodies disappeared after TPE in 1 patient. In 9% of TPE procedures, minor complications were noted. All patients were on posttransplant maintenance immunosuppression and several children received additional treatment (intravenous immunoglobulin therapy or rituximab) during TPE therapy. Conclusion TPE therapy (combined with immunosuppression) was an effective tool in most pediatric cases after renal transplantation with low incidence of minor adverse events. Highlights • This research highlights the efficacy of therapeutic plasma exchange (TPE). • TPE can be used as a therapeutic tool in children after renal transplantation. • TPE can be utilized in pediatric patients with recurrence of nephrotic syndrome, atypical hemolytic uremic syndrome, chronic antibody mediated rejection, and autoimmune thrombocytopenia. [ABSTRACT FROM AUTHOR]

Abstract Combined liver-kidney transplantation (CLKT) is a rare procedure in pediatric patients in which liver and kidney from 1 donor are transplanted to a recipient during a single operation. The aim of our study was to analyze indications and results of CLKT in children. Materials and Methods Between 1990 and 2017 we performed 722 liver transplantations in children; we performed 920 kidney transplantations in children since 1984. Among them, 25 received CLKT. Primary diagnosis was fibro-polycystic liver and kidney disease in 17 patients, primary hyperoxaluria type 1 in 6 patients, and atypical hemolytic uremic syndrome-related renal failure in 2 children. Age of patients at CLKT was 3 to 23 years (median 16 years) and body mass was 11 to 55 kg (median 35.5kg). All patients received whole liver graft. Kidney graft was transplanted after liver reperfusion before biliary anastomosis. Cold ischemia time was 5.5 to 13.3 hours (median 9.4 hours) for liver transplants and 7.3 to 15 hours (median 10.4 hours) for kidney transplants. In 8 patients X-match was positive. We analyzed posttransplant (Tx) course and late results in our group of pediatric recipients of combined grafts. Results Tx follow-up ranged from 1.5 to 17 years (median 4.5 years). Two patients died: 1 patient with oxalosis lost renal graft and died 2.6 years after Tx due to complications of long-term dialysis, and 1 died due to massive bleeding in early postoperative period. Twelve patients were transferred under the care of adult transplantation centers. Six patients were dialyzed after CLKT due to acute tubular necrosis, and time of kidney function recovery was 10 to 27 days in these patients. In 1 patient with aHUS, renal function did not recover. In children with oxalosis, hemodialysis was performed for 1 month after Tx as a standard, with the aim to remove accumulated oxalate. Primary immunosuppression consisted of daclizumab or basiliximab, tacrolimus, mycophenolate mofetil, and steroids. Acute rejection occurred in 4 liver and 3 kidney grafts. One patient required liver retransplantation due to hepatitis C virus recurrence and 2 patients required kidney retransplantation. Two patients required dialysis. Conclusions CLKT in children results in low rate of rejection and high rate of patient and graft survival. Highlights • Combined liver-kidney transplantation in children is followed by a low rate of rejection. • Good results in patients and graft survival. • Transplantations are feasible even in recipients with low body weight below 10 kg. [ABSTRACT FROM AUTHOR]

Abstract Background Cystinosis is a rare genetic disorder characterized by the abnormal accumulation of cystine in the lysosomes of various tissues and organs leading to their dysfunction. The most common type is the infantile nephropathic cystinosis which without treatment leads to renal failure and before the introduction of cysteamine was the cause of death before puberty. Case Presentation A 27-year-old female patient with infantile cystinosis developed end-stage renal disease at the age of 10. The first kidney transplantation from patient's father was carried out at the age of 12. The recurrent urinary tract infections led to the graft failure after 6 years. Following the removal of right appendages due to the ovarian tumor, the patient underwent the second kidney transplantation from her mother at the age of 19. After the transplantation, the cysteamine treatment was irregular due to limited availability of the medicine. When it became regular in 2017 the patient did not tolerate full doses. Despite elevated blood levels of cystine and the removal of right appendages, the patient naturally became pregnant in August 2017. Except for recurrent urinary tract infections, the renal parameters remained normal throughout the entire pregnancy. However, in the 32nd week of gestation, due to preeclampsia a caesarean section was performed. A healthy daughter was born, 1400/41 and with a 9 point Apgar score. Conclusions Due to the possibility of treatment with cysteamine and kidney transplantations, patients with cystinosis live longer and their quality of life improves. These female patients can even naturally become pregnant and give birth to healthy children. [ABSTRACT FROM AUTHOR]

Abstract: Background: The results of pediatric renal transplantation have improved markedly in the last decade. However, a number of relevant clinical problems remain, such as organ damage caused by chronic rejection, long-term toxicity of immunosuppressive therapy, difficulty in developing tolerance-inducing protocols, secondary cardiovascular comorbidity, post-transplantation lymphoproliferative disease, suboptimal longitudinal growth, quality of life, adherence to immunosuppressive medication, and structured transition programs to adult care. These unmet clinical needs require intense collaborative and interdisciplinary clinical research. We recently founded the Cooperative European Paediatric Renal TransplAnt INitiative (CERTAIN; www.certain-registry.eu) as a research network and platform built on a novel, web-based registry. Results: The registry's dataset provides essential information on generic kidney transplantation-related topics and also captures pediatric-specific topics, such as growth, physical and psychosocial development, and adherence. Due to its flexibility the system can be used as follows: (1) as a registry capturing a minimal or an extended dataset; (2) as a center and/or country-specific transplantation database; or (3) as a patient-specific electronic transplantation chart. The data can be exported directly from the CERTAIN web application into statistical software packages for scientific analyses. The rights regarding data ownership, evaluation, and publications are regulated in the registry's rules of procedure. Data quality is ensured by automatic software validation and a manual data review process. To avoid redundant data entry, CERTAIN has established interfaces for data change with Eurotransplant, the Collaborative Transplant Study (CTS), and the registry of the European Society of Pediatric Nephrology (ESPN) and European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) (ESPN/ERA-EDTA registry). CERTAIN fulfils all regulatory and ethical requirements of the European Union and Germany, in particular, regarding patients' data privacy and security. Conclusion: Using modern information technology, the recently established multinational CERTAIN Registry fills a gap in Europe for collaborative 5research and quality assurance in the field of pediatric renal transplantation. [Copyright &y& Elsevier]

Abstract: Introduction: Kidney transplantation is efficacious as a renal replacement, particularly pre-emptive living donation. In Poland, the rate of transplantation of living donor kidneys is only 3%. The aim of the study was to identify the most common reasons to disqualify a potential living kidney donor. Methods: We evaluated 124 kidney donor candidates for 111 potential recipients at 1 medical center for genders and ages of donor and recipient; thus relation, donor disqualification reasons, number of potential donors for a particular recipient, prior transplantations, and kidney vasculature. Results: The 111 recipients of ages 2–62 years had, 1, 2, or 3 potential donors were tested in 101, 1, and 7, cases respectively. We had 18.9% recipients referred for pre-emptive transplantation; 59.5% were on haemodialysis and 21.6% on peritoneal dialysis. In all, 89% recipients sought first kidney transplantations. Kidneys were procured from 49/124 (39.5%) of the initially evaluated donors. The full examination was completed by 92 potential donors with 68/124 donors disqualified early. Single and multiple renal arteries were detected in 56 and 36 potential donors, respectively. Donor disqualification was due to medical contraindications (39.7%), earlier transplantation from a deceased donor (25%), immunologic constraints (23.5%), donor consent withdrawn (6%) or psychological and social reasons (4.4%). Conclusions: A considerable number of donor candidates are disqualified for medical reasons. [Copyright &y& Elsevier]

Most kidney transplant patients who undergo biopsies are classified as having no rejection based on consensus thresholds. However, we hypothesized that because these patients have normal adaptive immune systems, T cell-mediated rejection (TCMR) and antibody-mediated rejection (ABMR) may exist as subthreshold activity in some transplants currently classified as no rejection. To examine this question, we studied genome-wide microarray results from 5086 kidney transplant biopsies (from 4170 patients). An updated molecular archetypal analysis designated 56% of biopsies as no rejection. Subthreshold molecular TCMR and/or ABMR activity molecular activity was detectable as elevated classifier scores in many biopsies classified as no rejection, with ABMR activity in many TCMR biopsies and TCMR activity in many ABMR biopsies. In biopsies classified as no rejection histologically and molecularly, molecular TCMR classifier scores correlated with increases in histologic TCMR features and molecular injury, lower estimated glomerular filtration rate, and higher risk of graft loss, and molecular ABMR activity correlated with increased glomerulitis and donor-specific antibody. No rejection biopsies with high subthreshold TCMR or ABMR activity had a higher probability of having TCMR or ABMR, respectively, diagnosed in a future biopsy. We conclude that many kidney transplant recipients have unrecognized subthreshold TCMR or ABMR activity, with significant implications for future problems., Competing Interests: Declaration of competing interest The authors of this manuscript have conflicts of interest to disclose as described by the American Journal of Transplantation. P.F. Halloran holds shares in Transcriptome Sciences Inc., a University of Alberta research company dedicated to developing molecular diagnostics, supported in part by a licensing agreement between Transcriptome Sciences Inc. and Thermo Fisher Scientific, and by a research grant from Natera, Inc. P.F. Halloran is a consultant to Natera, Inc. and Argenx BV. The other authors have declared no conflict of interest exists., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)