Correction: Balaphas et al. Cell Therapy for Anal Sphincter Incontinence: Where Do We Stand? Cells 2021, 10, 2086.

The authors would like to add a new reference to the section "3 [...].

Sodium Hydrosulfide Treatment During Porcine Kidney Ex Vivo Perfusion and Transplantation.

Background: In rodents, hydrogen sulfide (H2S) reduces ischemia-reperfusion injury and improves renal graft function after transplantation. Here, we hypothesized that the benefits of H2S are conserved in pigs, a more clinically relevant model. Methods: Adult porcine kidneys retrieved immediately or after 60 min of warm ischemia (WI) were exposed to 100 µM sodium hydrosulfide (NaHS) (1) during the hypothermic ex vivo perfusion only, (2) during WI only, and (3) during both WI and ex vivo perfusion. Kidney perfusion was evaluated with dynamic contrast-enhanced MRI. MRI spectroscopy was further employed to assess energy metabolites including ATP. Renal biopsies were collected at various time points for histopathological analysis. Results: Perfusion for 4 h pig kidneys with Belzer MPS UW + NaHS resulted in similar renal perfusion and ATP levels than perfusion with UW alone. Similarly, no difference was observed when NaHS was administered in the renal artery before ischemia. After autotransplantation, no improvement in histologic lesions or cortical/medullary kidney perfusion was observed upon H2S administration. In addition, AMP and ATP levels were identical in both groups. Conclusions: In conclusion, treatment of porcine kidney grafts using NaHS did not result in a significant reduction of ischemia-reperfusion injury or improvement of kidney metabolism. Future studies will need to define the benefits of H2S in human, possibly using other molecules as H2S donors.

Meeting report: Xenotransplantation Development Conference in Neijiang, China.

A conference on progress in the development of xenotransplantation in China was held in Neijiang, Sichuan, in May 2023, and was attended by approximately 100 established researchers and trainees. Progress in xenotransplantation research was reviewed by both Chinese and foreign experts. The topics discussed ranged from genetic engineering of pigs and the results of pig-to-nonhuman primate organ transplantation to the requirements for designated pathogen-free (DPF) pig facilities and regulation of xenotransplantation. This conference served as an opportunity to collectively advance the development of xenotransplantation in China and pave the way for its clinical application.

Thoracic epidural analgesia in intensive care unit patients with acute pancreatitis: the EPIPAN multicenter randomized controlled trial.

BACKGROUND: Findings from preclinical studies and one pilot clinical trial suggest potential benefits of epidural analgesia in acute pancreatitis. We aimed to assess the efficacy of thoracic epidural analgesia, in addition to usual care, in improving clinical outcomes of intensive care unit patients with acute pancreatitis. METHODS: A multicenter, open-label, randomized, controlled trial including adult patients with a clinical diagnosis of acute pancreatitis upon admission to the intensive care unit. Participants were randomly assigned (1:1) to a strategy combining thoracic epidural analgesia and usual care (intervention group) or a strategy of usual care alone (control group). The primary outcome was the number of ventilator-free days from randomization until day 30. RESULTS: Between June 2014 and January 2019, 148 patients were enrolled, and 135 patients were included in the intention-to-treat analysis, with 65 patients randomly assigned to the intervention group and 70 to the control group. The number of ventilator-free days did not differ significantly between the intervention and control groups (median [interquartile range], 30 days [15-30] and 30 days [18-30], respectively; median absolute difference of - 0.0 days, 95% CI - 3.3 to 3.3; p = 0.59). Epidural analgesia was significantly associated with longer duration of invasive ventilation (median [interquartile range], 14 days [5-28] versus 6 days [2-13], p = 0.02). CONCLUSIONS: In a population of intensive care unit adults with acute pancreatitis and low requirement for intubation, this first multicenter randomized trial did not show the hypothesized benefit of epidural analgesia in addition to usual care. Safety of epidural analgesia in this setting requires further investigation. TRIAL REGISTRATION: ClinicalTrials.gov registration number NCT02126332 , April 30, 2014.

Advantages of the retroperitoneal retrocolic space as the transplant site for encapsulated xenogeneic islets.

OBJECTIVE: Islet allotransplantation has demonstrated improved clinical outcomes using the hepatic portal vein as the standard infusion method. However, the current implantation site is not ideal due to the short-term thrombotic and long-term immune destruction. Meanwhile, the shortage of human organ donors further limits its application. To find a new strategy, we tested a new polymer combination for islet encapsulation and transplantation. Meanwhile, we explored a new site for xenogeneic islet transplantation in mice. METHOD: We synthesized a hydrogel combining alginate plus poly-ethylene-imine (Alg/PEI) for the encapsulation of rat, neonatal porcine, and human islets. Transplantation was performed into the retroperitoneal retro-colic space of diabetic mice. Control mice received free islets under the kidney capsule or encapsulated islets into the peritoneum. The biochemical indexes were measured, and the transplanted islets were harvested for immunohistochemical staining of insulin and glucagon. RESULTS: Mice receiving encapsulated rat, porcine and human islets transplanted into the retroperitoneal space maintained normoglycemia for a median of 275, 145.5, and 146 days, respectively. In contrast, encapsulated xenogeneic islets transplanted into the peritoneum, maintained function for a median of 61, 95.5, and 82 days, respectively. Meanwhile, xenogeneic islets transplanted free into the kidney capsule lost their function within 3 days after transplantation. Immunohistochemical staining of encapsulated rat, porcine and human islets, retrieved from the retroperitoneal space, allowed to distinguish morphological normal insulin expressing ß- and glucagon expressing α-cells at 70, 60, and 100 days post-transplant, respectively. CONCLUSION: Transplantation of Alg/PEI encapsulated xenogeneic islets into the retroperitoneal space provides a valuable new implantation strategy for the treatment of type 1 diabetes.

Isolation and Characterization of Stem Cells from the Anal Canal Transition Zone in Pigs.

BACKGROUND: Utilization of autologous stem cells has been proposed for the treatment of anal incontinence despite a lack of understanding of their mechanism of action and of the physiological healing process of anal sphincters after injury. AIMS: We aim to develop a technique allowing isolation and further study of local mesenchymal stem cells, directly from anal canal transition zone in pig. METHODS: Anal canal was resected "en bloc" from two young pigs and further microdissected. The anal canal transition zone was washed and digested with 0.1% type I collagenase for 45 min at 37 °C. The isolated cells were plated on dishes in mesenchymal stem cell medium and trypsinized when confluent. Cells were further used for flow cytometry analysis and differentiation assays. RESULTS: The anal canal transition zone localization was confirmed with H&E staining. Following culture, cells exhibited a typical "fibroblast-like" morphology typical of stem cells. Isolated cells were positive for CD90 and CD44 but negative for CD14, CD34, CD45, CD105, CD106, and SLA-DR. Following incubation with specific differentiation medium, isolated cells differentiated into adipocytes, osteoblasts, and chondrocytes, confirming in vitro multipotency. CONCLUSIONS: Herein, we report for the first time the presence of mesenchymal stem cells in the anal canal transition zone in pigs and the feasibility of their isolation. This preliminary study opens the path to the isolation of human anal canal transition zone mesenchymal stem cells that might be used to study sphincters healing and to treat anal incontinence.

Genetic engineering of pigs for xenotransplantation to overcome immune rejection and physiological incompatibilities: The first clinical steps.

Xenotransplantation has the potential to solve the shortfall of human organ donors. Genetically modified pigs have been considered as potential animal donors for human xenotransplantation and have been widely used in preclinical research. The genetic modifications aim to prevent the major species-specific barriers, which include humoral and cellular immune responses, and physiological incompatibilities such as complement and coagulation dysfunctions. Genetically modified pigs can be created by deleting several pig genes related to the synthesis of various pig specific antigens or by inserting human complement- and coagulation-regulatory transgenes. Finally, in order to reduce the risk of infection, genes related to porcine endogenous retroviruses can be knocked down. In this review, we focus on genetically modified pigs and comprehensively summarize the immunological mechanism of xenograft rejection and recent progress in preclinical and clinical studies. Overall, both genetically engineered pig-based xenografts and technological breakthroughs in the biomedical field provide a promising foundation for pig-to-human xenotransplantation in the future.

Retroperitoneal liposarcoma and craniosynostosis: possible genomic relationship, case report, and literature review.

Based on a case report, this review explores the genomic landscape for patients with liposarcomas and possible relationships with gene mutations related to craniosynostosis. We describe the case of a 40-year-old man, known for a surgical correction of craniosynostosis before the age of 1 year, who underwent a radical resection of a voluminous retroperitoneal liposarcoma; histopathological analysis revealed a low-grade well-differentiated, mostly sclerosing, liposarcoma. A genetic analysis searching for mutations in blood DNA was performed and did not detect any specific mutation. A literature review was also conducted. Several tumors related to syndromic and non-syndromic craniosynostosis are mentioned in the literature; no specific link with retroperitoneal liposarcoma is established but the FGFR3 mutation is detected in dedifferentiated liposarcomas. To date, no case has been reported in the literature demonstrating a genetic relationship between craniosynostosis and low-grade differentiated retroperitoneal liposarcoma. We conclude that further studies for gene complex mutations should be conducted to show a possible genetic relationship between retroperitoneal liposarcoma and craniosynostosis.

Pancreatic stone protein as a biomarker for the early diagnosis of post-operative peritonitis, intra-abdominal infection and sepsis.

The diagnosis of intra-abdominal infection and post-operative peritonitis based on clinical examination, biomarkers and radiological signs, should be made as early as possible to improve outcomes and decrease mortality through early and optimal source control, adequate surgery and appropriate antibiotic therapy (Montravers et al. Therapeutic management of peritonitis: a comprehensive guide for intensivists. Intensive Care Med 2016;42:1234-47). However, the indication and the timing of the surgery is often not an easy decision. This case presents the use of a novel early biomarker of infection and sepsis, pancreatic stone protein (Fidalgo et al. Pancreatic stone protein: review of a new biomarker in sepsis. J Clin Med 2022;11:1085), as a tool to aid in the diagnosis of intra-abdominal infection and post-operative peritonitis and to help guide the decision for adequate surgeries in a patient with intra-abdominal infection and post radical prostatectomy peritonitis.

Subnormothermic Ex Vivo Porcine Kidney Perfusion Improves Energy Metabolism: Analysis Using 31P Magnetic Resonance Spectroscopic Imaging.

The ideal preservation temperature for donation after circulatory death kidney grafts is unknown. We investigated whether subnormothermic (22 °C) ex vivo kidney machine perfusion could improve kidney metabolism and reduce ischemia-reperfusion injury. Methods: To mimic donation after circulatory death procurement, kidneys from 45-kg pigs underwent 60 min of warm ischemia. Kidneys were then perfused ex vivo for 4 h with Belzer machine perfusion solution UW at 22 °C or at 4 °C before transplantation. Magnetic resonance spectroscopic imaging coupled with LCModel fitting was used to assess energy metabolites. Kidney perfusion was evaluated with dynamic-contrast enhanced MRI. Renal biopsies were collected at various time points for histopathologic analysis. Results: Total adenosine triphosphate content was 4 times higher during ex vivo perfusion at 22 °C than at 4 °C perfusion. At 22 °C, adenosine triphosphate levels increased during the first hours of perfusion but declined afterward. Similarly, phosphomonoesters, containing adenosine monophosphate, were increased at 22 °C and then slowly consumed over time. Compared with 4 °C, ex vivo perfusion at 22 °C improved cortical and medullary perfusion. Finally, kidney perfusion at 22 °C reduced histological lesions after transplantation (injury score: 22 °C: 10.5 ± 3.5; 4 °C: 18 ± 2.25 over 30). Conclusions: Ex vivo kidney perfusion at 22°C improved graft metabolism and protected from ischemia-reperfusion injuries upon transplantation. Future clinical studies will need to define the benefits of subnormothermic perfusion in improving kidney graft function and patient's survival.

Xenotransplantation: A New Era.

Organ allotransplantation has now reached an impassable ceiling inherent to the limited supply of human donor organs. In the United States, there are currently over 100,000 individuals on the national transplant waiting list awaiting a kidney, heart, and/or liver transplant. This is in contrast with only a fraction of them receiving a living or deceased donor allograft. Given the morbidity, mortality, costs, or absence of supportive treatments, xenotransplant has the potential to address the critical shortage in organ grafts. Last decade research efforts focused on creation of donor organs from pigs with various genes edited out using CRISPR technologies and utilizing non-human primates for trial. Three groups in the United States have recently moved forward with trials in human subjects and obtained initial successful results with pig-to-human heart and kidney xenotransplantation. This review serves as a brief discussion of the recent progress in xenotransplantation research, particularly as it concerns utilization of porcine heart, renal, and liver xenografts in clinical practice.

Engineering Islets From Stem Cells: The Optimal Solution for the Treatment of Diabetes?

Diabetes is a metabolic disease characterized by insulin deficiency. Bioengineering of stem cells with the aim to restore insulin production and glucose regulation has the potential to cure diabetic patients. In this review, we focus on the recent developments for bioengineering of induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), and pancreatic progenitor cells in view of generating insulin producing and glucose regulating cells for ß-cell replacement therapies. Recent clinical trials using islet cells derived from stem cells have been initiated for the transplantation into diabetic patients, with crucial bottlenecks of tumorigenesis, post-transplant survival, genetic instability, and immunogenicity that should be further optimized. As a new approach given high expectations, bioengineered islets from stem cells occupies considerable potential for the future clinical application and addressing the treatment dilemma of diabetes.

Optimized Isolation and Characterization of C57BL/6 Mouse Hepatic Stellate Cells.

To obtain meaningful results of hepatic stellate cell (HSC) function, it is crucial to use highly pure HSC populations. Our aim was to optimize HSC isolation from mice livers without exploiting the characteristically transient vitamin A autofluorescence of HSC. HSCs were isolated from C57BL/6 mice using a two-step collagenase digestion and Nycodenz gradient separation followed by CD11b-negative sorting step in order to remove contaminating macrophages and dendritic cells. Isolated cells were analyzed for yield, viability, purity, and potential new markers using immunofluorescence and flow cytometry. We obtained a yield of 350,595 ± 100,773 HSC per mouse liver and a viability of isolated cells of 92.4 ± 3.1%. We observed a low macrophage/dendritic cell contamination of 1.22 ± 0.54%. Using flow cytometry, we demonstrated that CD38 was expressed at the surface of HSC subpopulations and that all expressed intracellular markers specific for HSC in the liver. This isolation method, avoiding fluorescent activated cell sorting (FACS), allowed isolation of HSCs with high purity. Further, flow cytometry analysis suggests that CD38 may be a reliable marker of HSCs and may include subpopulations of HSCs without retinoid droplets.

Islet Encapsulation: New Developments for the Treatment of Type 1 Diabetes.

Islet transplantation is a promising approach for the treatment of type 1 diabetes (T1D). Currently, clinical islet transplantation is limited by allo - and autoimmunity that may cause partial or complete loss of islet function within a short period of time, and long-term immunosuppression is required to prevent rejection. Encapsulation into semipermeable biomaterials provides a strategy that allows nutrients, oxygen and secreted hormones to diffuse through the membrane while blocking immune cells and the like out of the capsule, allowing long-term graft survival and avoiding long-term use of immunosuppression. In recent years, a variety of engineering strategies have been developed to improve the composition and properties of encapsulation materials and to explore the clinical practicality of islet cell transplantation from different sources. In particular, the encapsulation of porcine islet and the co-encapsulation of islet cells with other by-standing cells or active ingredients for promoting long-term functionality, attracted significant research efforts. Hydrogels have been widely used for cell encapsulation as well as other therapeutic applications including tissue engineering, cell carriers or drug delivery. Here, we review the current status of various hydrogel biomaterials, natural and synthetic, with particular focus on islet transplantation applications. Natural hydrophilic polymers include polysaccharides (starch, cellulose, alginic acid, hyaluronic acid, chitosan) and peptides (collagen, poly-L-lysine, poly-L-glutamic acid). Synthetic hydrophilic polymers include alcohol, acrylic acid and their derivatives [poly (acrylic acid), poly (methacrylic acid), poly(acrylamide)]. By understanding the advantages and disadvantages of materials from different sources and types, appropriate materials and encapsuling methods can be designed and selected as needed to improve the efficacy and duration of islet. Islet capsule transplantation is emerging as a promising future treatment for T1D.

Robotic versus hand-assisted laparoscopic living donor nephrectomy: comparison of two minimally invasive techniques in kidney transplantation.

Robot-assisted donor nephrectomy (RDN) is increasingly used due to its advantages such as its precision and reduced learning curve when compared to laparoscopic techniques. Concerns remain among surgeons regarding possible longer warm ischemia time. This study aimed to compare patients undergoing robotic living donor nephrectomy to the more frequently used hand-assisted laparoscopic nephrectomy (HLDN) technique, focusing on warm ischemia time, total operative time, learning curve, hospital length of stay, donor renal function and post-operative complications. Retrospective study comparing RDN to HLDN in a collaborative transplant network. 176 patients were included, 72 in RDN and 104 in HLDN. Left-sided nephrectomy was favored in RDN (82% vs 52%, p < 0.01). Operative time was longer in RDN (287 vs 160 min; p < 0.01), while warm ischemia time was similar (221 vs 213 secs, p = 0.446). The hospital stay was shorter in RDN (3.9 vs 5.7 days, p < 0.01).Concerning renal function, a slightpersistent increase of 7% of the creatinine ratio was observed in the RDN compared to the HLDN group (1.56 vs 1.44 at 1-month checkup, p < 0.01). The results show that RDN appears safe and efficient in comparison to the gold-standard HLDN technique. Warm ischemia time was similar for both techniques, whereas RDN operative time was longer. Patients undergoing RDN had a shorter hospital stay, this being possibly mitigated by differences in center release criteria. Donor renal function needs to be assessed on a longer-term basis for both techniques.

Multipotent Mesenchymal Stromal Cells Interact and Support Islet of Langerhans Viability and Function.

Type 1 diabetes (T1D) is a widespread disease, affecting approximately 41.5 million people worldwide. It is generally treated with exogenous insulin, maintaining physiological blood glucose levels but also leading to long-term therapeutic complications. Pancreatic islet cell transplantation offers a potential alternative treatment to insulin injections. Shortage of human organ donors has raised the interest for porcine islet xenotransplantation. Neonatal porcine islets are highly available, can proliferate and mature in vitro as well as after transplantation in vivo. Despite promising preclinical results, delayed insulin secretion caused by immaturity and immunogenicity of the neonatal porcine islets remains a challenge for their clinical application. Multipotent mesenchymal stromal cells (MSCs) are known to have pro-angiogenic, anti-inflammatory and immunomodulatory effects. The current state of research emphasizes the great potential of co-culture and co-transplantation of islet cells with MSCs. Studies have shown enhanced islet proliferation and maturation, insulin secretion and graft survival, resulting in an improved graft outcome. This review summarizes the immunomodulatory and anti-inflammatory properties of MSC in the context of islet transplantation.