Type III-B CRISPR-Cas cascade of proteolytic cleavages.

The generation of cyclic oligoadenylates and subsequent allosteric activation of proteins that carry sensory domains is a distinctive feature of type III CRISPR-Cas systems. In this work, we characterize a set of associated genes of a type III-B system from that contains two caspase-like proteases, SAVED-CHAT and PCaspase (prokaryotic caspase), co-opted from a cyclic oligonucleotide-based antiphage signaling system (CBASS). Cyclic tri-adenosine monophosphate (AMP)-induced oligomerization of SAVED-CHAT activates proteolytic activity of the CHAT domains, which specifically cleave and activate PCaspase.

First case report of multivisceral transplant from a deceased cardiac death donor.

The current shortage of pediatric multivisceral donors accounts for the long time and mortality on the waiting list of pediatric patients. The use of donors after cardiac death, especially after the outbreak of normothermic regional perfusion, has increased in recent years for all solid organs except the intestine, mainly because of its higher susceptibility to ischemia-reperfusion injury. We present the first literature case of multivisceral donors after cardiac death transplantation in a 13-month-old recipient from a 2.

First multivisceral transplantation in Mitchell-Riley/Martinez-Frias syndrome.

Background: MRS/MFS is a rare multisystem disorder with a poor prognosis. The high mortality rate of this syndrome is related to the severity of the associated gastrointestinal, pancreatic, and hepatobiliary conditions, as most of them are not amenable to conventional medical and surgical treatments.

Methods: We report the case of a Romani girl with all the key clinical features of MRS/MFS, and a review of cases reported in the literature.

Severe Lymphopenia as a Predictor of COVID-19 Mortality in Immunosuppressed Patients.

Background: Coronavirus disease 2019 (COVID-19) has a high mortality in certain group of patients. We analysed the impact of baseline immunosuppression in COVID-19 mortality and the role of severe lymphopenia in immunocompromised subjects.

Methods: We analysed all patients admitted with COVID-19 in a tertiary hospital in Madrid between March 1st and April 30th 2020.

Delayed introduction of sirolimus in paediatric intestinal transplant recipients: indications and long-term benefits.

To review our experience using sirolimus in a single centre paediatric intestinal transplantation cohort. Intestinal transplant patients with more than 3 months follow-up were divided into two groups according to their immunosuppression regimen: tacrolimus, (TAC group, n = 45 grafts) or sirolimus (SRL group, n = 38 grafts), which included those partially or completely converted from tacrolimus to sirolimus. The indications to switch were tacrolimus side effects and immunological complications.

Native Spleen Preservation During Visceral Transplantation Inhibits Graft-Versus-Host-Disease Development: Clinical and Experimental Study.

Objective: We aimed to assess whether native spleen preservation during visceral transplantation (VT) affects graft-versus-host-disease (GVHD) incidence.

Summary Background Data: GVHD is one of the most severe and frequently lethal hematological complications after VT procedures. Because there is no specific treatment for GVHD, it is imperative to develop a strategy to reduce donor lymphocyte engraftment and proliferation.

New mutations associated with Hirschsprung disease.

Introduction: Hirschsprung Disease is caused by an impairment in cell migration from the neural crest to the gastrointestinal tract, resulting in an absence of neurons in the myenteric plexus. Many mutations in several genes have been associated to Hirschsprung disease; most of them affecting the RET proto-oncogen pathway. The purpose of this study is the description of novel and known mutations in genes associated to Hirschsprung disease and their prognostic implications.

Graft infusion of adipose-derived mesenchymal stromal cells to prevent rejection in experimental intestinal transplantation: A feasibility study.

Background: Mesenchymal stromal cells (MSC) have been proposed as a promising complement to standard immunosuppression in solid organ transplantation because of their immunomodulatory properties. The present work addresses the role of adipose-derived MSC (Ad-MSC) in an experimental model of acute rejection in small bowel transplantation (SBT).

Material/methods: Heterotopic allogeneic SBT was performed.

Donor's graft ex vivo T-cell depletion with fludarabine reduces graft-versus-host disease signs and improves survival after intestinal transplantation - an experimental study.

Intestinal passenger T leukocytes are responsible for graft-versus-host disease (GvHD) in intestinal transplantation (ITx). We hypothesized that ex vivo fludarabine treatment of the bowel graft would diminish the risk of GvHD and improve overall survival post-transplant. We performed isolated heterotopic small bowel transplantations from Lewis (LEW) to Brown Norway (BN) rat strains, which generated GvHD signs from the fourth day post-transplant.

Current status of pediatric intestinal transplant in Europe.

Purpose Of Review: This review features articles published during 2018 and 2019 regarding pediatric visceral transplantation in Europe. In this biannual review, the authors identify and summarize key articles pertinent to clinical and research areas.

Recent Findings: There is a trend to a lower use of intestinal transplantation in pediatric population in Europe.

[New mutations associated with Hirschsprung disease].

Introduction: Hirschsprung disease is caused by an impairment in cell migration from the neural crest to the gastrointestinal tract, resulting in an absence of neurons in the myenteric plexus. Many mutations in several genes have been associated to Hirschsprung disease; most of them affecting the RET proto-oncogen pathway. The purpose of this study is the description of novel and known mutations in genes associated to Hirschsprung disease and their prognostic implications.

Prognostic Factors for Liver Transplantation in Unresectable Hepatoblastoma.

Aim:  Hepatoblastoma is the most frequent hepatic tumor in children, and its initial presentation will affect treatment and prognosis. The aim of this study is to evaluate long-term results of liver transplantation in children with unresectable hepatoblastoma.

Patients And Methods:  This is a retrospective review of patients with hepatoblastoma who underwent liver transplantation, analyzing risk factors, tumor presentation, treatment, and long-term survival to identify prognostic factors.

Long-Term Results after Diversion Surgery in Extrahepatic Portal Vein Obstruction.

Aim:  Extrahepatic portal vein obstruction (EHPVO) is a frequent cause of noncirrhotic portal hypertension in children. The aim of this study is to analyze long-term results after diversion surgery.

Patients And Methods:  Retrospective review of EHPVO patients who underwent diversion surgery analyzing number of platelets, leukocytes, prothrombin activity, splenomegaly, and gastrointestinal bleeding 10 years after surgery.

Long-term results of surgery for bowel lengthening: how many transplants are avoided, for which patients?

Purpose Of Review: One of the biggest successes of intestinal rehabilitation programs is that more patients achieve enteral autonomy without transplantation. Many factors are responsible of this accomplishment including new parenteral formulas, better catheter management, surgical management, and the experience of the teams. The purpose of this review is to analyze recent published papers regarding intestinal lengthening procedures trying to find out how many transplantations are avoided and for which patients.

Pancreatic Kaposiform Hemangioendothelioma Not Responding to Sirolimus.

 Kaposiform hemangioendothelioma (KHE) is a vascular tumor frequently associated with Kasabach-Merritt phenomenon (KMP), characterized by severe thrombocytopenia and consumptive coagulopathy. Visceral involvement in KHE is rare. In our recent experience, sirolimus has shown to be an effective treatment in cutaneous KHE, becoming indeed the treatment of choice in KMP.

Difficulties, guidelines and review of developing an acute rejection model after rat intestinal transplantation.

Experimental small bowel transplantation (SBT) in rats has been proven to be a useful tool for the study of ischemia-reperfusion and immunological aspects related to solid organ transplantation. However, the model is not completely refined, specialized literature is scarce and complex technical details are typically omitted or confusing. Most studies related to acute rejection (AR) use the orthotopic standard, with small sample sizes due to its high mortality, whereas those studying chronic rejection (CR) use the heterotopic standard, which allows longer term survival but does not exactly reflect the human clinical scenario.

Surgical Rehabilitation Techniques in Children with Poor Prognosis Short Bowel Syndrome.

Intestinal failure (IF) requires a multidisciplinary management based on nutritional support, surgical and medical rehabilitation, and transplantation. The aim of this study is to review our experience with surgical rehabilitation techniques (SRTs: enteroplasty, Bianchi, Serial Transverse Enteroplasty Procedure [STEP]) in patients with short bowel syndrome (SBS) and poor prognosis due to complex abdominal pathology. We performed a single-center retrospective study of patients with IF evaluated for intestinal transplantation in the Intestinal Rehabilitation Unit who underwent an SRT.

Congenital Portosystemic Shunts: Clinic Heterogeneity Requires an Individual Management of the Patient.

Introduction: Congenital portosystemic shunt (CPSS) is a rare entity without insufficiency in treatment issues. The aim of this article is to show our experience in the heterogeneity of this condition.

Material And Methods: A retrospective study of 25 CPSS in the period 1995 to 2014 was conducted.

Ulcerative ileitis after proctocolectomy in children: a complication of ulcerative colitis or a disease in itself after ileoanal pullthrough?

Ulcerative ileitis (UI) after restorative proctocolectomy (RPC) and ileoanal pullthrough procedure (IAPP) is a rare condition described as inflammation of the terminal ileum proximal to the anastomosis. It is mostly observed in ulcerative colitis (UC) and is designated as prepouch ileitis; sometimes with pouchitis, but not necessarily all the time. Its incidence in adults is less than 5%, but the information in children is limited.

Liver transplantation for classical maple syrup urine disease: long-term follow-up.

Objectives: The aim of the study was to evaluate indications, results, and clinical and neurological evolution in children who have undergone liver transplantation for classical maple syrup urine disease (MSUD).

Methods: Descriptive study of liver transplantation for MSUD between 1991 and 2012. Eight patients were transplanted.

Post-transplant lymphoproliferative disorders and other malignancies after pediatric intestinal transplantation: incidence, clinical features and outcome.

PTLDs are a well-recognized and potentially fatal complication after intestinal transplantation. We analyzed the incidence, clinical features, and outcome in a 63 intestinal transplantation series performed in our unit between October 1999 and July 2011. Types of graft included ISB (n = 23), LSB (n = 20), and MV (n = 20).

Ischemic preconditioning of the graft for intestinal transplantation in rats.

To test the hypothesis that two modalities of IPC should decrease acute rejection and BT after SBTx in rats. Orthotopic allogenic SBTx was performed from Wistar to BN. IPC was performed by 2 ' and 5 ' superior mesenteric artery clamping, following 2-min and 5-min reperfusion before graft cooling and retrieving.