National centralization of Hirschsprung's disease in Sweden: a comparison of postoperative outcome.

BACKGROUND: In Sweden, surgical treatment of Hirschsprung's disease (HSCR) was centralized from four to two pediatric surgery centers 1st of July 2018. In adults, centralization of surgical care for complex or rare diseases seems to improve quality of care. There is little evidence supporting centralization of pediatric surgical care. The aim of this study was to assess surgical management and postoperative outcome in HSCR patients following centralization of care. METHODS: This study retrospectively analyzed data of patients with HSCR that had undergone pull-through at a pediatric surgery center in Sweden from 1st of July 2013 to 30th of June 2023. Patients managed from 1st of July 2013 to 30th of June 2018 (before centralization) were compared with patients managed from 1st of July 2018 to 30th of June 2023 (after centralization) regarding surgical treatment, unplanned procedures under general anesthesia or readmissions up to 90 days after pull-through as well as complications classified according to Clavien-Madadi up to 30 days after pull-through. RESULTS: In the 5-year period prior to centralization, 114 individuals from 4 treating centers were included and compared to 83 patients from 2 treating centers in the second period. There was no difference regarding age at pull-through or proportion of patients with a stoma prior to pull-through. An increase of laparoscopically assisted endorectal pull-through (8.8% to 39.8%) was observed (p < 0.001). No significant differences were seen in postoperative hospital stay, unplanned procedures under general anesthesia, or readmissions up to 90 days after pull-through. There was no difference in severe complications (Clavien-Madadi ≥ 3); however, HAEC treated with antibiotics increased following centralization (10.5-24.1%; p = 0.018). CONCLUSION: Centralization of care for HSCR does not seem to delay time to pull-through nor reduce severe complications, unplanned procedures under general anesthesia or readmissions up to 90 days after pull-through. The increased HAEC rate may be due to increased awareness of mild HAEC. LEVEL OF EVIDENCE:  Level III.

Dangerous liaisons: complement, coagulation, and kallikrein/kinin cross-talk act as a linchpin in the events leading to thromboinflammation.

Innate immunity is fundamental to our defense against microorganisms. Physiologically, the intravascular innate immune system acts as a purging system that identifies and removes foreign substances leading to thromboinflammatory responses, tissue remodeling, and repair. It is also a key contributor to the adverse effects observed in many diseases and therapies involving biomaterials and therapeutic cells/organs. The intravascular innate immune system consists of the cascade systems of the blood (the complement, contact, coagulation, and fibrinolytic systems), the blood cells (polymorphonuclear cells, monocytes, platelets), and the endothelial cell lining of the vessels. Activation of the intravascular innate immune system in vivo leads to thromboinflammation that can be activated by several of the system's pathways and that initiates repair after tissue damage and leads to adverse reactions in several disorders and treatment modalities. In this review, we summarize the current knowledge in the field and discuss the obstacles that exist in order to study the cross-talk between the components of the intravascular innate immune system. These include the use of purified in vitro systems, animal models and various types of anticoagulants. In order to avoid some of these obstacles we have developed specialized human whole blood models that allow investigation of the cross-talk between the various cascade systems and the blood cells. We in particular stress that platelets are involved in these interactions and that the lectin pathway of the complement system is an emerging part of innate immunity that interacts with the contact/coagulation system. Understanding the resulting thromboinflammation will allow development of new therapeutic modalities.

Controlled outcome of Hirschsprung's disease beyond adolescence: a single center experience.

PURPOSE: The aim of this study was to assess the function and quality of life of Hirschsprung's Disease (HD) beyond adolescence and relate it to matched controls. METHODS: All 203 patients diagnosed with HD at our department from 1961 to 1995 were identified. 21 had died, 43 had unclear diagnosis and 16 could not be traced. The remaining 123 patients were sent bowel function and SF-36 quality of life questionnaires. 69 patients (mean age 37.8, range 22-58, 13 female) responded and were matched with 138 age and sex-matched controls. RESULTS: Function: HD-patients had significantly higher number of bowel movements per week, higher incidence of soiling, urgency, permanent stomas, use of laxatives, enemas and loperamide. HD-patients also scored significantly lower in their satisfaction with their bowel function. There was, however, no significant difference in Miller Incontinence score. QOL: HD-patients reported a significantly higher incidence of negative impact by their bowel function on daily life, social interaction and ability to go on vacation. There were no significant differences in SF-36-scores. CONCLUSIONS: Bowel function has a lifelong negative impact on the lives of patients with HD. This strongly indicates a need for structured follow-up beyond adolescence.

Antroduodenal manometry findings in children with suspected pediatric intestinal pseudo-obstruction.

BACKGROUND: In 2018 diagnostic criteria for pediatric intestinal pseudo-obstruction (PIPO) were established. Neuromuscular dysfunction of the gastrointestinal tract is one of these, and often examined through antroduodenal manometry (ADM). There is little data on antroduodenal manometries in children. Our objectives were to retrospectively apply these criteria to children evaluated for suspected motility disorder, to reevaluate the ADM patterns and compare children who did and did not meet the PIPO criteria and also with healthy adults. METHODS: Children with a suspected gastrointestinal motility disorder previously investigated with 24-h 8-lead ADM were reevaluated by applying the 2018 ESPGHAN/NASPGHAN PIPO diagnostic criteria and the 2018 ANMS-NASPGHAN guidelines. ADM findings were compared between children who retrospectively fulfilled a PIPO diagnosis, children who did not, and a control group of healthy adults. KEY RESULTS: Of 34 children (age 7.9 (±5.1) years, 18 males), 12 retrospectively fulfilled the 2018 PIPO diagnostic criteria. Twenty-five children (10 in the PIPO group) had abnormal diagnostic findings on ADM, whereas 9 (2 in the PIPO group) had no such findings. A PIPO diagnosis implied a significantly higher degree of abnormal ADM patterns (2.33 vs. 1.23, p = 0.02). There were no major differences in quantitative ADM measurements between the groups except higher pressures in children. CONCLUSIONS AND INFERENCES: Children who retrospectively fulfilled a PIPO diagnosis had a significantly higher abundance of abnormal ADM findings compared with symptomatic children without PIPO and healthy adults. Our data indicate a need for set criteria for evaluation of ADM in children with suspected PIPO.

Exposure of von Willebrand Factor on Isolated Hepatocytes Promotes Tethering of Platelets to the Cell Surface.

BACKGROUND: Hepatocyte transplantation (Hctx) is a potentially attractive method for the treatment of acute liver failure and liver-based metabolic disorders. Unfortunately, the procedure is hampered by the instant blood-mediated inflammatory reaction (IBMIR), a thromboinflammatory response elicited by the vascular innate immune system, causing activation of the coagulation and complement systems and clearance of transplanted cells. Observations have also revealed platelets adhered to the surface of the hepatocytes (Hc). To establish Hctx as a clinical treatment, all factors that trigger IBMIR need to be identified and controlled. This work explores the expression of von Willebrand factor (VWF) on isolated Hc resulting in tethering of platelets. METHODS: VWF on Hc was studied by flow cytometry, confocal microscopy, immunoblot, and real-time polymerase chain reaction. Interaction between Hc and platelets was studied in a Chandler loop model. Adhesion of platelets to the hepatocyte surface was demonstrated by flow cytometry and confocal microscopy. RESULTS: Isolated Hc constitutively express VWF on their cell surface and mRNA for VWF was found in the cells. Hc and platelets, independently of coagulation formed complexes, were shown by antibody blocking studies to be dependent on hepatocyte-associated VWF and platelet-bound glycoprotein Ibα. CONCLUSIONS: VWF on isolated Hc causes, in contact with blood, adhesion of platelets, which thereby forms an ideal surface for coagulation. This phenomenon needs to be considered in hepatocyte-based reconstitution therapy and possibly even in other settings of cell transplantation.

A novel chromogranin-A promoter-driven oncolytic adenovirus for midgut carcinoid therapy.

PURPOSE: The use of replication-selective oncolytic adenoviruses is an emerging therapeutic approach for cancer, which thus far has not been employed for carcinoids. We therefore constructed Ad[CgA-E1A], a novel replication-selective oncolytic adenovirus, where the chromogranin A (CgA) promoter controls expression of the adenoviral E1A gene. EXPERIMENTAL DESIGN: The Ad[CgA-E1A] virus was evaluated for E1A protein expression, replication ability, and cytolytic activity in various cell lines. It was also evaluated for treatment of xenografted human carcinoid tumors in nude mice. To use Ad[CgA-E1A] for the treatment of carcinoid liver metastases, it is important that normal hepatocytes do not support virus replication to minimize hepatotoxicity. We therefore evaluated CgA protein expression in normal hepatocytes. We also evaluated CgA gene expression in normal hepatocytes and microdissected tumor cells from carcinoid metastases. RESULTS: We found that Ad[CgA-E1A] replicates similarly to wild-type virus in tumor cells with neuroendocrine features, including the BON carcinoid cell line and the SH-SY-5Y neuroblastoma cell lines, whereas it is attenuated in other cell types. Thus, cells where the CgA promoter is active are selectively killed. We also found that Ad[CgA-E1A] is able to suppress fast-growing human BON carcinoid tumors in nude mice. Furthermore, CgA is highly expressed in microdissected cells from carcinoid metastases, whereas it is not expressed in normal hepatocytes. CONCLUSION: Ad[CgA-E1A] is an interesting agent for the treatment of carcinoid liver metastases in conjunction with standard therapy for these malignancies.

Cell Adhesion Induced Using Surface Modification with Cell-Penetrating Peptide-Conjugated Poly(ethylene glycol)-Lipid: A New Cell Glue for 3D Cell-Based Structures.

We synthesized a novel material, cell-penetrating peptide-conjugated poly(ethylene glycol)-lipid (CPP-PEG-lipid), that can induce the adhesion of floating cells. Firm cell adhesion with spreading could be induced by cell surface modification with the CPP-PEG-lipids. Cell adhesion was induced by CPPs but not by any other cationic short peptides we tested. Here, we demonstrated adherence using the floating cell line CCRF-CEM as well as primary human T cells, B cells, erythrocytes, and hepatocytes. As compared to cells grown in suspension, adherent cells were more rapidly induced to attach to substrates with the cell-surface modification. The critical factor for attachment was localization of CPPs at the cell membrane by PEG-lipids with PEG > 20 kDa. These cationic CPPs on PEG chains were able to interact with substrate surfaces such as polystyrene (PS) surfaces, glass surfaces, and PS microfibers that are negatively charged, inducing firm cell adhesion and cell spreading. Also, as opposed to normal cationic peptides that interact strongly with cell membranes, CPPs were less interactive with the cell surfaces because of their cell-penetrating property, making them more available for adhering cells to the substrate surface. No effects on cell viability or cell proliferation were observed after the induction of cell adhesion. With this technique, cells could be easily immobilized onto PS microfibers, an important step in fabricating 3D cell-based structures. Cells immobilized onto 3D PS microfibers were alive, and human hepatocytes showed normal production of urea and albumin on the microfibers. This method is novel in inducing firm cell adhesion via a one-step treatment.

Control of IBMIR Induced by Fresh and Cryopreserved Hepatocytes by Low Molecular Weight Dextran Sulfate Versus Heparin.

Rapid destruction of hepatocytes after hepatocyte transplantation has hampered the application of this procedure clinically. The instant blood-mediated inflammatory reaction (IBMIR) is a plausible underlying cause for this cell loss. The present study was designed to evaluate the capacity of low molecular weight dextran sulfate (LMW-DS) to control these initial reactions from the innate immune system. Fresh and cryopreserved hepatocytes were tested in an in vitro whole-blood model using ABO-compatible blood. The ability to elicit IBMIR and the capacity of LMW-DS (100 µg/ml) to attenuate the degree of activation of the cascade systems were monitored. The effect was also compared to conventional anticoagulant therapy using unfractionated heparin (1 IU/ml). Both fresh and freeze-thawed hepatocytes elicited IBMIR to the same extent. LMW-DS reduced the platelet loss and maintained the cell counts at the same degree as unfractionated heparin, but controlled the coagulation and complement systems significantly more efficiently than heparin. LMW-DS also attenuated the IBMIR elicited by freeze-thawed cells. Therefore, LMW-DS inhibits the cascade systems and maintains the cell counts in blood triggered by both fresh and cryopreserved hepatocytes in direct contact with ABO-matched blood. LMW-DS at a previously used and clinically applicable concentration (100 µg/ml) inhibits IBMIR in vitro and is therefore a potential IBMIR inhibitor in hepatocyte transplantation.

Outcome and management in infants with esophageal atresia - A single centre observational study.

BACKGROUND/PURPOSE: A successful outcome in the repair of esophageal atresia (EA) is associated with a high quality pediatric surgical centre, however there are several controversies regarding the optimal management. The aim of this study was to investigate the outcome and management EA in a single pediatric surgical centre. METHODS: Medical records of infants with repaired EA from 1994 to 2013 were reviewed. RESULTS: 129 infants were included. Median follow-up was 5.3 (range 0.1-21) years. Overall survival was 94.6%, incidences of anastomotic leakage 7.0%, recurrent fistula 4.6% and anastomotic stricture 53.5% (36.2% within first year). In long gap EA (n=13), delayed primary anastomosis was performed in 9 (69.2%), gastric tube in 3 (23.1%) and gastric transposition in one (7.7%) infants. The incidences of anastomotic leakage and stricture in long gap EA were, 23.1% and 69.2%, respectively. Peroperative tracheobronchoscopy and postoperative esophagography were implemented as a routine during the study-period, but chest drains were routinely abandoned. CONCLUSION: The outcome in this study is fully comparable with recent international reports showing a low mortality but a significant morbidity, especially considering anastomotic strictures and LGEA. Multicenter EA registry with long-term follow up may help to establish best management of EA.

Heparinization of cell surfaces with short peptide-conjugated PEG-lipid regulates thromboinflammation in transplantation of human MSCs and hepatocytes.

Infusion of therapeutic cells into humans is associated with immune responses, including thromboinflammation, which result in a large loss of transplanted cells. To address these problems, heparinization of the cell surfaces was achieved by a cell-surface modification technique using polyethylene glycol-conjugated phospholipid (PEG-lipid) derivatives. A short heparin-binding peptide was conjugated to the PEG-lipid for immobilization of heparin conjugates on the surface of human mesenchymal stem cells (hMSCs) and human hepatocytes. Here three kinds of heparin-binding peptides were used for immobilizing heparin conjugates and examined for the antithrombogenic effects on the cell surface. The heparinized cells were incubated in human whole blood to evaluate their hemocompatibility by measuring blood parameters such as platelet count, coagulation markers, complement markers, and Factor Xa activity. We found that one of the heparin-binding peptides did not show cytotoxicity after the immobilization with heparin conjugates. The degree of binding of the heparin conjugates on the cell surface (analyzed by flow cytometer) depended on the ratio of the active peptide to control peptide. For both human MSCs and hepatocytes in whole-blood experiments, no platelet aggregation was seen in the heparin conjugate-immobilized cell group vs. the controls (non-coated cells or control peptide). Also, the levels of thrombin-antithrombin complex (TAT), C3a, and sC5b-9 were significantly lower than those of the controls, indicating a lower activation of coagulation and complement. Factor Xa analysis indicated that the heparin conjugate was still active on the cell surface at 24h post-coating. It is possible to immobilize heparin conjugates onto hMSC and human hepatocyte surfaces and thereby protect the cell surfaces from damaging thromboinflammation. STATEMENT OF SIGNIGFICANCE: We present a promising approach to enhance the biocompatibility of therapeutic cells. Here we used short peptide-conjugated PEG-lipid for cell surface modification and heparin conjugates for the coating of human hepatocytes and MSCs. We screened the short peptides to find higher affinity for heparinization of cell surface and performed hemocompatibility assay of heparinized human hepatocytes and human MSCs in human whole blood. Using heparin-binding peptide with higher affinity, not only coagulation activation but also complement activation was significantly suppressed. Thus, it was possible to protect human hepatocytes and human MSCs from the attack of thromboinflammatory activation, which can contribute to the improvement graft survival.

Phenotypic expansion of visceral myopathy associated with ACTG2 tandem base substitution.

Familial visceral myopathy (FVM) is a rare heritable and heterogeneous condition due to impaired smooth muscle function. We identified a family segregating 11 individuals with a spectrum of visceral symptoms involving the small intestine, colon, biliary tract, urinary tract and uterus. Whole-exome sequencing revealed a novel heterozygous tandem base substitution c.806_807delinsAA (p.(Gly269Glu)) in ACTG2, encoding smooth muscle actin γ-2, in affected family members. Variants in ACTG2 were recently identified in FVM with intestinal pseudo-obstruction as well as with the congenital megacystics-microcolon-intestinal hypoperistalsis syndrome. In our family, eight affected members presented with severe complications from the biliary and/or the urinary tracts in addition to gastrointestinal pseudo-obstructions. Furthermore, all affected mothers had a history of assisted deliveries owing to poor progress during labor and weak uterine contractions. The variable involvement of multiple smooth muscle-dependent organs in our family, including the biliary tract and the uterus, add to the phenotypic spectrum associated with ACTG2 missense variants.

The instant blood-mediated inflammatory reaction characterized in hepatocyte transplantation.

BACKGROUND: Hepatocyte transplantation (HcTx) has proven to be a safe procedure, although the functional results have been unsatisfactory, probably due to insufficient engraftment or a loss of transplanted mass or function. In this study, we investigate whether hepatocytes in contact with blood induce an inflammatory reaction leading to, similar to what happens in clinical islet transplantation, an instant blood-mediated inflammatory reaction (IBMIR) resulting in an early loss of transplanted cells. METHODS: By using an experimental model that mimics the portal vein blood flow, we could study different parameters reflecting the effects on the innate immunity elicited by hepatocytes in contact with ABO-matched human blood. RESULTS: We report that all aspects of the IBMIR such as platelet and granulocyte consumption, coagulation, and complement activation were demonstrated. Addition of various specific inhibitors of coagulation allowed us to clearly delineate the various stages of the hepatocyte-triggered IBMIR and show that the reaction was triggered by tissue factor. Analysis of a case of clinical HcTx showed that hepatocyte-induced IBMIR also occurs in vivo. Both the inflammatory and the coagulation aspects were controlled by low-molecular-weight dextran sulfate. CONCLUSION: Isolated hepatocytes in contact with blood induce the IBMIR in vitro, and there are indications that these events are also relevant in vivo. According to these findings, HcTx would benefit from controlling a wider range of signals from the innate immune system.

Double-detargeted oncolytic adenovirus shows replication arrest in liver cells and retains neuroendocrine cell killing ability.

BACKGROUND: We have previously developed an oncolytic serotype 5 adenovirus (Ad5) with chromogranin-A (CgA) promoter-controlled E1A expression, Ad[CgA-E1A], with the intention to treat neuroendocrine tumors, including carcinoids. Since carcinoids tend to metastasize to the liver it is important to fully repress viral replication in hepatocytes to avoid adenovirus-related liver toxicity. Herein, we explore miRNA-based regulation of E1A expression as a complementary mechanism to promoter-based transcriptional control. METHODOLOGY/PRINCIPAL FINDINGS: Ad[CgA-E1A-miR122], where E1A expression is further controlled by six tandem repeats of the target sequence for the liver-specific miR122, was constructed and compared to Ad[CgA-E1A]. We observed E1A suppression and replication arrest of the miR122-detargeted adenovirus in normal hepatocytes, while the two viruses killed carcinoid cells to the same degree. Repeated intravenous injections of Ad[CgA-E1A] induced liver toxicity in mice while Ad[CgA-E1A-miR122] injections did not. Furthermore, a miR122-detargeted adenovirus with the wild-type E1A promoter showed reduced replication in hepatic cells compared to wild-type Ad5 but not to the same extent as the miR122-detargeted adenovirus with the neuroendocrine-selective CgA promoter. CONCLUSIONS/SIGNIFICANCE: A combination of transcriptional (promoter) and post-transcriptional (miRNA target) regulation to control virus replication may allow for the use of higher doses of adenovirus for efficient tumors treatment without liver toxicity.