Pancreas Transplantation Outcome Predictions-PTOP: A Risk Prediction Tool for Pancreas and Pancreas-Kidney Transplants Based on a European Cohort

Background

For patients with complicated type 1 diabetes having, for example, hypoglycemia unawareness and end-stage renal disease because of diabetic nephropathy, combined pancreas and kidney transplantation (PKT) is the therapy of choice. However, the shortage of available grafts and complex impact of risk factors call for individualized, impartial predictions of PKT and pancreas transplantation (PT) outcomes to support physicians in graft acceptance decisions.

Methods

Based on a large European cohort with 3060 PKT and PT performed between 2006 and 2021, the 3 primary patient outcomes time to patient mortality, pancreas graft loss, and kidney graft loss were visualized using Kaplan-Meier survival curves. Multivariable Cox proportional hazards models were developed for 5- and 10-y prediction of outcomes based on 26 risk factors.

Results

Risk factors associated with increased mortality included previous kidney transplants, rescue allocations, longer waiting times, and simultaneous transplants of other organs. Increased pancreas graft loss was positively associated with higher recipient body mass index and donor age and negatively associated with simultaneous transplants of kidneys and other organs. Donor age was also associated with increased kidney graft losses. The multivariable Cox models reported median C-index values were 63% for patient mortality, 62% for pancreas loss, and 55% for kidney loss.

Conclusions

This study provides an online risk tool at https://riskcalc.org/ptop for individual 5- and 10-y post-PKT and PT patient outcomes based on parameters available at the time of graft offer to support critical organ acceptance decisions and encourage external validation in independent populations.

Postoperative prophylactic antibiotic therapy after pancreaticoduodenectomy in bile duct-stented patients reduces postoperative major complications

BACKGROUND

Pancreaticoduodenectomy can entail a high complication rate, especially in patients who underwent preoperative bile duct drainage through bile duct stenting. Pancreaticoduodenectomy bile duct stenting patients frequently receive prophylactic antibiotic therapy in the postoperative period. However, the exact value and the benefit of prophylactic antibiotic therapy in pancreaticoduodenectomy bile duct stenting patients remains under-investigated and thus unclear.

METHOD

We conducted a retrospective single-center study of pancreaticoduodenectomy bile duct stenting patients between January 2007 and December 2022. Demographic, clinical, laboratory, and pathology data of 370 patients were collected, and intraoperative swab cultures of the bile were obtained from all patients upon transection of the common bile duct. The groups to be investigated were formed on the basis of postoperative antibiotic prophylaxis. Postoperative complications and antibiotic resistance analysis were recorded.

RESULTS

Postoperative antibiotic prophylaxis in stented patients after pancreaticoduodenectomy significantly reduced major complications (odds ratio: 0.547 [95% confidence interval 0.327-0.915]; P = .02) such as reoperation (P = .041) and readmission to the intensive care unit (P = .037). Patients with Enterococcus faecalis (odds ratio: 1.699 [95% confidence interval 0.978-2.950];P = .048), Enterococcus faecium (odds ratio: 1.808 [95% confidence interval 1.001-3.264]; P = .050), or Citrobacter (odds ratio: 2.211 [95% confidence interval 1.087-4.497]; P = .029) in their bile had a higher probability of developing wound infections. Appropriate antibiotic prophylaxis, according to the bile duct microbiome, significantly reduced the risk of wound infection (odds ratio: 2.239 [95% confidence interval 1.167-4.298]; P = .015).

CONCLUSION

Postoperative antibiotic prophylaxis in pancreaticoduodenectomy bile duct stenting patients significantly reduced major complications such as intensive care stay and reoperation. Targeted antibiotic treatment according to the biliary microbiome reduced the incidence of wound infections.

Liver Resection in Synchronous Bilobar versus Unilobar Colorectal Liver Metastases: A Retrospective Analysis of Oncological Outcomes and Patient Survival

INTRODUCTION

Resection of colorectal liver metastasis has emerged as the standard treatment. Our study compares oncological outcomes of patients with resected synchronous bilobar versus unilobar colorectal liver metastasis.

METHODS

This retrospective study presents long-term follow-up data of 105 consecutive patients with primary colorectal cancer and synchronous liver metastasis. All patients underwent primary tumor and metastasis resections between 2007 and 2019.

RESULTS

Fifty-five patients with bilobar and 50 patients with unilobar colorectal liver metastases were included. No significant difference in overall, tumor-specific, or recurrence-free survival was observed between patients with bilobar and unilobar metastases. After case-control matching, the results were confirmed in patients with similar tumor burdens. In the multivariate analysis, chemotherapy following liver metastasis resection was a significant prognostic factor associated with improved overall survival (hazard ratio 0.518, 95% confidence interval: 0.302-0.888, p = 0.017).

CONCLUSION

Overall survival, as well as tumor-specific and recurrence-free survival, did not differ between patients with unilobar and bilobar liver metastasis. These findings contribute to the understanding that primary tumor and metastasis resection in eligible patients improve long-term outcomes.

Rescue Allocation Modes in Eurotransplant Kidney Transplantation: Recipient Oriented Extended Allocation Versus Competitive Rescue Allocation-A Retrospective Multicenter Outcome Analysis

BACKGROUND

Whenever the kidney standard allocation (SA) algorithms according to the Eurotransplant (ET) Kidney Allocation System or the Eurotransplant Senior Program fail, rescue allocation (RA) is initiated. There are 2 procedurally different modes of RA: recipient oriented extended allocation (REAL) and competitive rescue allocation (CRA). The objective of this study was to evaluate the association of patient survival and graft failure with RA mode and whether or not it varied across the different ET countries.

METHODS

The ET database was retrospectively analyzed for donor and recipient clinical and demographic characteristics in association with graft outcomes of deceased donor renal transplantation (DDRT) across all ET countries and centers from 2014 to 2021 using Cox proportional hazards methods.

RESULTS

Seventeen thousand six hundred seventy-nine renal transplantations were included (SA 15 658 [89%], REAL 860 [4.9%], and CRA 1161 [6.6%]). In CRA, donors were older, cold ischemia times were longer, and HLA matches were worse in comparison with REAL and especially SA. Multivariable analyses showed comparable graft and recipient survival between SA and REAL; however, CRA was associated with shorter graft survival. Germany performed 76% of all DDRTs after REAL and CRA and the latter mode reduced waiting times by up to 2.9 y.

CONCLUSIONS

REAL and CRA are used differently in the ET countries according to national donor rates. Both RA schemes optimize graft utilization, lead to acceptable outcomes, and help to stabilize national DDRT programs, especially in Germany.

Liver Fibrosis Is Associated with Poorer Overall Survival and Higher Recurrence Rate in Patients with Cholangiocarcinoma

INTRODUCTION

Cholangiocarcinoma is the second most common primary liver tumour worldwide with an increasing incidence in recent decades. While the effects of fibrosis on hepatocellular carcinoma have been widely demonstrated, the impact on cholangiocarcinoma remains unclear. The aim of this study was to evaluate the impact of liver fibrosis on overall survival (OS) and disease-free survival (DFS) in patients who have undergone liver resection for cholangiocarcinoma.

METHODS

Eighty patients with cholangiocarcinoma who underwent curatively intended liver surgery between January 2007 and December 2020 were included in this retrospective single-centre study. Clinical and histopathological features were analysed. The primary endpoint was cause-specific survival. Secondary endpoints were DFS and identification of prognostic factors.

RESULTS

The present study shows that the median OS is significantly reduced in patients with fibrosis (p < 0.001). The median OS in patients with fibrosis was three times shorter than in the group without fibrosis. In addition, a significantly shorter DFS was observed in patients with fibrosis (p < 0.002). Multivariate analysis showed that fibrosis is the strongest independent factor with a negative impact on OS and DFS.

CONCLUSION

Liver fibrosis has a significant impact on OS and DFS in patients with cholangiocarcinoma. Patients with known liver fibrosis require thorough perioperative care and postoperative follow-up.

Hepatocellular Brg1 promotes CCl4-induced liver inflammation, ECM accumulation and fibrosis in mice

INTRODUCTION

Hepatic fibrosis is a progressive pathological process involving the exhaustion of hepatocellular regenerative capacity and ultimately leading to the development of cirrhosis and even hepatocellular carcinoma. Brg1, the core subunit of the SWI/SNF chromatin-remodeling complex, was recently identified as important for liver regeneration. This study investigates the role of Brg1 in hepatic fibrosis development.

METHODS

Hepatocyte-specific Brg1 knockout mice were generated and injected with carbon tetrachloride (CCl4) for 4, 6, 8, and 12 weeks to induce liver fibrosis. Afterwards, liver fibrosis and liver damage were assessed.

RESULTS

Brg1 expression was significantly increased in the fibrotic liver tissue of wild-type mice, as compared to that of untreated wild-type mice. The livers of the Brg1 knockout animals showed reduced liver inflammation, extracellular matrix accumulation, and liver fibrosis. TNF-α and NF-κB-mediated inflammatory response was reduced in Brg1 knockout animals.

CONCLUSION

Brg1 promotes the progression of liver fibrosis in mice and may therefore be used as a potential therapeutic target for treating patients with liver fibrosis due to chronic injury.

Effect of different PD-1 inhibitor combination therapies for unresectable intrahepatic cholangiocarcinoma

BACKGROUND

Immune checkpoint inhibitor (ICI) combination therapy offers a new option for treatment of unresectable intrahepatic cholangiocarcinoma (uICC).

AIM

To compare the effect of different anti-PD-1 combination therapies as the first-line treatments for uICC.

METHODS

This study included 318 patients who received chemotherapy alone (Chemo), anti-PD-1 plus chemotherapy (ICI-chemo), anti-PD-1 plus targeted therapy (ICI-target) or anti-PD-1 plus targeted therapy and chemotherapy (ICI-target-chemo) as first line for uICC from 22 centres in China. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR) and safety.

RESULTS

Patients with ICI-chemo (median PFS [mPFS], 6.3 months; HR: 0.61, 95% CI: 0.42-0.88; p = 0.008; median OS [mOS], 10.7 months; HR: 0.61, 95% CI: 0.39-0.94; p = 0.026), ICI-target (7.2 months; HR: 0.54, 95% CI: 0.36-0.80; p = 0.002; 15.8 months; HR: 0.54, 95% CI: 0.35-0.84; p = 0.006) or ICI-target-chemo (6.9 months; HR: 0.65, 95% CI: 0.47-0.90; p = 0.009; 14.4 months; HR: 0.47, 95% CI: 0.31-0.70; p < 0.001) achieved better clinical outcomes than those with Chemo (3.8 months; 9.3 months). ICI-target was not inferior to ICI-chemo in survival outcomes (HR for PFS: 0.88, 95% CI: 0.55-1.42; p = 0.614; HR for OS: 0.89, 95% CI: 0.51-1.55; p = 0.680). ICI-target-chemo yielded similar prognoses as ICI-chemo (HR for PFS: 1.07, 95% CI: 0.70-1.62; p = 0.764; HR for OS: 0.77, 95% CI: 0.45-1.31; p = 0.328) and ICI-target (HR for PFS: 1.20, 95% CI: 0.77-1.88; p = 0.413; HR for OS: 0.86, 95% CI: 0.51-1.47; p = 0.583) but resulted in more adverse events (p < 0.001; p = 0.010). Multivariable and propensity score analyses supported these findings.

CONCLUSIONS

Among patients with uICC, ICI-chemo or ICI-target provided more survival benefits than Chemo while achieving comparable prognoses and fewer adverse events than ICI-target-chemo.

Hepatitis B virus targets lipid transport pathways to infect hepatocytes

BACKGROUND AND AIMS

A single hepatitis B virus (HBV) particle is sufficient to establish chronic infection of the liver after intravenous injection, suggesting that the virus targets hepatocytes via a highly efficient transport pathway. We therefore investigated whether HBV utilizes a physiological liver-directed pathway that supports specific host-cell targeting in vivo.

METHODS

We established an ex vivo system of perfused human liver tissue that recapitulates the liver physiology to investigate HBV liver targeting. This model allowed us to investigate virus-host cell interactions in a cellular microenvironment mimicking the in vivo situation.

RESULTS

HBV was rapidly sequestered by liver macrophages within one hour after a virus pulse, but was detected in hepatocytes only after 16 hours. We found that HBV associates with lipoproteins. Electron- and immunofluorescence microscopy corroborated a co-localization in recycling endosomes within peripheral and liver macrophages. Importantly, recycling endosomes accumulated HBV and cholesterol, followed by transport of HBV back to the cell surface along the cholesterol efflux pathway. To reach hepatocytes as final target cells, HBV was able to utilise the hepatocyte-directed cholesterol transport machinery of macrophages.

CONCLUSIONS

Our results propose that HBV by binding to liver targeted lipoproteins and utilizing the reverse cholesterol transport pathway of macrophages hijacks the physiological lipid transport pathways to the liver to most efficiently reach its target organ. This may involve trans-infection of liver macrophages and result in deposition of HBV in the perisinusoidal space from where HBV can bind its receptor on hepatocytes.

Gut microbiota promote liver regeneration through hepatic membrane phospholipid biosynthesis

BACKGROUND & AIMS

Hepatocyte growth and proliferation depends on membrane phospholipid biosynthesis. Short-chain fatty acids (SCFAs) generated by bacterial fermentation, delivered through the gut-liver axis, significantly contribute to lipid biosynthesis. We therefore hypothesized that dysbiotic insults like antibiotic treatment not only affect gut microbiota, but also impair hepatic lipid synthesis and liver regeneration.

METHODS

Stable isotope labeling and 70% partial hepatectomy (PHx) was carried out in C57Bl/6J wild-type mice, in mice treated with broad-spectrum antibiotics, in germ-free mice and mice colonized with minimal microbiota. The microbiome was analyzed by 16S rRNA gene sequencing and microbial culture. Gut content, liver, blood and primary hepatocyte organoids were tested by mass spectrometry-based lipidomics, quantitative reverse-transcription PCR (qRT-PCR), immunoblot and immunohistochemistry for expression of proliferative and lipogenic markers. Matched biopsies from hyperplastic and hypoplastic liver tissue of patients subjected to surgical intervention to induce hyperplasia were analyzed by qRT-PCR for lipogenic enzymes.

RESULTS

Three days of antibiotic treatment induced persistent dysbiosis with significantly decreased beta-diversity and richness, but a massive increase of Proteobacteria, accompanied by decreased colonic SCFAs. After PHx, antibiotic-treated mice showed delayed liver regeneration, increased mortality, impaired hepatocyte proliferation and decreased hepatic phospholipid synthesis. Expression of the lipogenic enzyme SCD1 was upregulated after PHx but delayed by antibiotic treatment. Germ-free mice essentially recapitulated the phenotype of antibiotic treatment. Phospholipid biosynthesis, hepatocyte proliferation, liver regeneration and survival were rescued in gnotobiotic mice colonized with a minimal SCFA-producing microbial community. SCFAs induced the growth of murine hepatocyte organoids and hepatic SCD1 expression in mice. Further, SCD1 was required for proliferation of human hepatoma cells and was associated with liver regeneration in human patients.

CONCLUSION

Gut microbiota are pivotal for hepatic membrane phospholipid biosynthesis and liver regeneration.

IMPACT AND IMPLICATIONS

Gut microbiota affect hepatic lipid metabolism through the gut-liver axis, but the underlying mechanisms are poorly understood. Perturbations of the gut microbiome, e.g. by antibiotics, impair the production of bacterial metabolites, which normally serve as building blocks for membrane lipids in liver cells. As a consequence, liver regeneration and survival after liver surgery is severely impaired. Even though this study is preclinical, its results might allow physicians in the future to improve patient outcomes after liver surgery, by modulation of gut microbiota or their metabolites.

Kidney Transplantation Outcome Predictions (KTOP): A Risk Prediction Tool for Kidney Transplants from Brain-dead Deceased Donors Based on a Large European Cohort

BACKGROUND

European kidney donation shortages mandate efficient organ allocation by optimizing the prediction of success for individual recipients.

OBJECTIVE

To develop the first European online risk tool for kidney transplant outcomes on the basis of recipient-only and recipient plus donor characteristics.

DESIGN, SETTING, AND PARTICIPANTS

We used individual recipient and donor risk factors and three outcomes (death, death with functioning graft [DWFG], and graft loss) for 32 958 transplants within the Eurotransplant kidney allocation system and the Eurotransplant senior program between January 2006 and May 2018 in eight European countries to develop and validate a risk tool.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cox proportional-hazards models were used to analyze the association of risk factors with overall patient mortality, and proportional subdistribution hazard regression models for their association with graft loss and DWFG. Prediction models were developed with recipient-only and recipient-donor risk factors. Sensitivity analyses based on time-specific area under the receiver operating characteristic curve (AUC) with leave-one-country-out validation were performed and calibration plots were generated.

RESULTS AND LIMITATIONS

The 10-yr cumulative incidence rate was 37% for mortality, 12% for DWFG, and 41% for graft loss. In recipient-donor models the leading risk factors for mortality were recipient diabetes (hazard ratio [HR] 10.73), retransplantation (HR 3.08 per transplant), and recipient age (HR 1.08). Effects were similar for DWFG. For graft loss, diabetes (subdistributional HR [SHR] 1.32), increased donor age (SHR 1.02), and prolonged cold ischemia time (SHR 1.02) had increased SHRs. All p values were <0.001.

CONCLUSIONS

Previously identified risk factors for outcomes following kidney transplants allow for outcome prediction with 10-yr AUC values of up to 0.81.

PATIENT SUMMARY

Using European data, we estimated individual risks to predict the success of kidney transplants and support physicians in decision-making. An online tool is now available (https://riskcalc.org/ktop/) for predicting kidney transplant outcomes both before and after a donor has been identified.

Long-term outcome of patients with epiphrenic diverticula: A retrospective single-center analysis over 20 years

BACKGROUND

Epiphrenic diverticula are extremely rare. Evidence-based treatment recommendations are scarce. The primary study outcome was to examine whether surgical treatment in patients with epiphrenic diverticula leads to improved quality of life by outweighing the perioperative risks compared with conservative treatment.

METHODS

All patients with an epiphrenic diverticula at our institution between 2001 and 2021 were retrospectively reviewed and followed-up using a specific questionnaire, including the Eating Assessment Tool, and Gastrointestinal Quality of Life Index quality-of-life scores.

RESULTS

Of 51 patients with epiphrenic diverticula, 28 had surgery and 23 had conservative treatment. The most common symptom at presentation was dysphagia. Although 16 patients underwent open surgery, 12 had minimally invasive procedures. A prophylactic stent was applied intraoperatively in 6 patients. The morbidity rate in surgically treated patients was 50% (14/28), with a leakage in 43% (12/28; 33% for prophylactic stenting). Mortality was nil. At a median follow-up of 139 months, patients with surgery had better outcomes than those without (ie, less dysphagia [6/12 vs 11/12; P = .025]), a less likely pathologic Eating Assessment Tool score (4/12 vs 9/12; P = .041), and a nonsignificant better Gastrointestinal Quality of Life Index score (122 vs 112; P = .929). The rate of recurrence/progression of symptoms was significantly higher for conservatively treated patients (11/18 vs 6/27 for any surgery; P = .008), as well as for patients with minimally invasive procedure (5/12 vs 1/15 for open surgery; P = .030).

CONCLUSION

Despite the high perioperative morbidity, surgical treatment of epiphrenic diverticula leads to an improved long-term quality of life and lower recurrence rates than conservative treatment.

softALPPS - A novel, individual procedure for patients with advanced liver tumors

BACKGROUND

The first-line therapy for liver malignancies is a radical extended liver resection. This high-risk operation has a high incidence of post-hepatectomy liver failure (PHLF) due to a small future liver remnant (FLR). One of the procedures to increase the FLR is the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) which is still associated with high morbidity and mortality. Here, we present a new, less invasive ALPPS variant that may be associated with lower morbidity.

METHODS

SoftALPPS is characterized by reduced trauma to the liver tissue and individual adaptation to the patient's health constitution. In softALPPS, portal vein embolization (PVE) is performed instead of portal vein ligation (PVL) after complete recovery of liver function. In addition, a non-absorbable foil was avoided in order to be able to extend the interval to step two or skip step two when required.

RESULTS

Four patients successfully underwent softALPPS. Two of these patients have been followed-up for over a year (one patient with Klatskin tumor, one patient with extensive HCC). Both patients show no evidence of recurrence after 12 months and are in good medical condition. The other two patients who recently had surgery are also doing well.

CONCLUSION

SoftALPPS offers the chance to curatively resect patients with high tumor burden of the liver even when the FLR is inadequate. This individual therapy method can give patients the possibility of complete tumor resection and can help to reduce perioperative morbidity.

Kidney Transplantation After Rescue Allocation-the Eurotransplant Experience: A Retrospective Multicenter Outcome Analysis

BACKGROUND

At Eurotransplant (ET), kidneys are transferred to "rescue allocation" (RA), whenever the standard allocation (SA) algorithms Eurotransplant Kidney Allocation System (ETKAS) and Eurotransplant Senior Program (ESP) fail. We analyzed the outcome of RA.

METHODS

Retrospective patient clinical and demographic characteristics association analyses were performed with graft outcomes for 2422 recipients of a deceased donor renal transplantation (DDRT) after RA versus 25 481 after SA from 71 centers across all ET countries from 2006 to 2018.

RESULTS

Numbers of DDRTs after RA increased over the time, especially in Germany. RA played a minor role in ESP versus ETKAS (2.7% versus 10.4%). RA recipients and donors were older compared with SA recipients and donors, cold ischemia times were longer, waiting times were shorter, and the incidence of primary nonfunction was comparable. Among ETKAS recipients, HLA matching was more favorable in SA (mean 3.7 versus 2.5). In multivariate modeling, the incidence of graft loss in ETKAS recipients was reduced in RA compared with SA (subdistribution hazard ratio, 0.80; 95% confidence interval [0.70-0.91], P < 0.001), whereas other outcomes (mortality, death with functioning graft (DwFG)) were not significantly different. None of the 3 outcomes were significantly different when comparing RA with SA within the ESP program.

CONCLUSIONS

Facing increased waiting times and mortality on dialysis due to donor shortage, this study reveals encouragingly positive DDRT outcomes following RA. This supports the extension of RA to more patients and as an alternative tool to enable transplantation in patients in countries with prohibitively long waiting times or at risk of deterioration.

Novel Risk Classification Based on Pyroptosis-Related Genes Defines Immune Microenvironment and Pharmaceutical Landscape for Hepatocellular Carcinoma

Growing evidence has indicated that pyroptosis functions in the development of cancer. Nonetheless, specific roles of pyroptosis-related genes in tumor progression, immune response, prognosis, and immunotherapy have not been thoroughly elucidated. After a comprehensive evaluation of pyroptosis genes, unsupervised clustering was performed to generate three distinct clusters from hepatocellular carcinoma (HCC) samples. Three distinct pyroptosis-related molecular subtypes comprising three gene clusters that had differential prognostic effects on patient survival were then identified. Immune characteristics analyses revealed diversified immune cell infiltration among the subtypes. Two clusters served as immune-hot phenotypes associated with significantly poorer survival compared to a remaining third immune-cold cluster. Among these, the immune-hot clusters were characterized by abundant adaptive immune cell infiltration, active CD4+ and CD8+ T cells, high total leukocyte counts and tumor growth status, and lower Th17 cell and M2 macrophage densities. Then, risk scores indicated that low-risk patients were more sensitive to anti-tumor therapy. Subsequently, we found a significant correlation between pyroptosis and prognosis in HCC and that pyroptosis genes drive the heterogeneity of the tumor microenvironment. The risk scoring system, based on pyroptosis-related differentially expressed genes, was established to evaluate the individual outcomes and contribute to new insights into the molecular characterization of pyroptosis-related subtypes.

[Effects of the first COVID-19 wave on visceral surgery : A retrospective comparison of case numbers from a university hospital and a primary care hospital]

Hintergrund

Während der ersten COVID-19-Pandemiewelle führte die Aussetzung aller elektiven Eingriffe im Zeitraum vom 15.03. bis 15.05.2020 in Deutschland zu einem Rückgang an Operationen. Die Auswirkungen auf die Zahl spezifischer Operationen in der Viszeralchirurgie sind bislang nicht bekannt.

Methoden

In diese retrospektive Studie wurden 301 Patienten eingeschlossen, die eine Cholezystektomie bzw. Appendektomie an einem Universitätsklinikum oder Krankenhaus der Grund- und Regelversorgung zwischen dem 15.03.2020 und 05.05.2020 (vs. 2018 und 2019) erhielten. Analysiert wurden die Fallzahlen und der klinische Verlauf.

Ergebnisse

Die Aussetzung des Elektivprogramms führte zu einer signifikanten Reduktion elektiver Cholezystektomien und notfallmäßiger Appendektomien. Am Universitätsklinikum reduzierte sich die Anzahl der Appendektomien von 24 im Jahr 2018 um 33 % auf 16 im Jahr 2020, die Zahl der Cholezystektomien sank von 30 um 57 % auf 13. Am Grundversorger reduzierte sich die Zahl der Appendektomiepatienten von 23 im Jahr 2018 um 48 % auf 12 im Jahr 2020, die Zahl der Cholezystektomien stieg im Jahr 2018 auf 2019 an und sank anschließend um 30 % im Jahr 2020. Die Operationsdauer, Krankenhausverweildauer und der klinische Verlauf der Patienten unterschied sich nicht signifikant zu den Vorjahreszeiträumen.

Diskussion

Der Lockdown während der ersten COVID-19-Pandemiewelle führte zu einer deutlichen Reduktion häufiger viszeralchirurgischer Eingriffe. Um die medizinische Versorgung der gesamten Bevölkerung während einer Pandemie möglichst auf hohem Niveau zu erhalten, müssen aktuelle Möglichkeiten der operativen und konservativen Therapie, unter anderem abhängig von lokalen Infektionszahlen und den individuellen Komorbiditäten der Patienten, gegeneinander abgewogen werden.

Kidney transplantation after rescue allocation-meticulous selection yields the chance for excellent outcome

BACKGROUND

The small number of organ donors forces transplant centres to consider potentially suboptimal kidneys for transplantation. Eurotransplant established an algorithm for rescue allocation (RA) of kidneys repeatedly declined or not allocated within 5 h after procurement. Data on the outcomes and benefits of RA are scarce to date.

METHODS

We conducted a retrospective 8-year analysis of transplant outcomes of RA offers based on our in-house criteria catalogue for acceptance and decline of organs and potential recipients.

RESULTS

RA donors and recipients were both older compared with standard allocation (SA). RA donors more frequently had a history of hypertension, diabetes or fulfilled expanded criteria donor key parameters. RA recipients had poorer human leucocyte antigen (HLA) matches and longer cold ischaemia times (CITs). However, waiting time was shorter and delayed graft function, primary non-function and biopsy-proven rejections were comparable to SA. Five-year graft and patient survival after RA were similar to SA. In multivariate models accounting for confounding factors, graft survival and mortality after RA and SA were comparable as well.

CONCLUSIONS

Facing relevant comorbidities and rapid deterioration with the risk of being removed from the waiting list, kidney transplantation after RA was identified to allow for earlier transplantation with excellent outcome. Data from this survey propose not to reject categorically organs from multimorbid donors with older age and a history of hypertension or diabetes to aim for the best possible HLA matching and to carefully calculate overall expected CIT.

Auto-aggressive CXCR6+ CD8 T cells cause liver immune pathology in NASH

Nonalcoholic steatohepatitis (NASH) is a manifestation of systemic metabolic disease related to obesity, and causes liver disease and cancer^1,2. The accumulation of metabolites leads to cell stress and inflammation in the liver³, but mechanistic understandings of liver damage in NASH are incomplete. Here, using a preclinical mouse model that displays key features of human NASH (hereafter, NASH mice), we found an indispensable role for T cells in liver immunopathology. We detected the hepatic accumulation of CD8 T cells with phenotypes that combined tissue residency (CXCR6) with effector (granzyme) and exhaustion (PD1) characteristics. Liver CXCR6⁺ CD8 T cells were characterized by low activity of the FOXO1 transcription factor, and were abundant in NASH mice and in patients with NASH. Mechanistically, IL-15 induced FOXO1 downregulation and CXCR6 upregulation, which together rendered liver-resident CXCR6⁺ CD8 T cells susceptible to metabolic stimuli (including acetate and extracellular ATP) and collectively triggered auto-aggression. CXCR6⁺ CD8 T cells from the livers of NASH mice or of patients with NASH had similar transcriptional signatures, and showed auto-aggressive killing of cells in an MHC-class-I-independent fashion after signalling through P2X7 purinergic receptors. This killing by auto-aggressive CD8 T cells fundamentally differed from that by antigen-specific cells, which mechanistically distinguishes auto-aggressive and protective T cell immunity.

Postoperative adjuvant transarterial chemoembolization for intrahepatic cholangiocarcinoma patients with microvascular invasion: a propensity score analysis

Background

Microvascular invasion (MVI) is an independent risk factor associated with tumor recurrence and poor survival in patients with intrahepatic cholangiocarcinoma (ICC) after partial hepatectomy (PH). The potential impact of adjuvant TACE on the prognosis of patients with ICC involving MVI (ICC-MVI) remains uncertain. Our aim was to investigate the effectiveness of postoperative adjuvant transarterial chemoembolization (TACE) on ICC involving MVI.

Methods

Multicentric data consisted of 223 patients who underwent curative-intent PH for ICC-MVI from 2002-2015 were retrospectively analyzed. The impact of adjuvant TACE was evaluated using inverse probability of treatment weighting (IPTW) and propensity-score matched (PSM) analyses.

Results

No association between the TACE and the overall survival (OS) and recurrence rates was observed among the overall ICC-MVI patients. However, subgroup analyses revealed that adjuvant TACE favored OS (HR, 0.62; 95% CI, 0.39-0.99; P=0.047) and time to recurrence (TTR) (HR, 0.59; 95% CI, 0.36-0.97; P=0.037) among patients with elevated CA19-9 and those without lymphadenectomy (HR, 0.53; 95% CI, 0.30-0.93; P=0.027 for OS, and HR, 0.49; 95% CI, 0.28-0.87; P=0.015 for TTR, respectively). In the CA19-9 ≥39 U/L subgroup and Nx subgroup, adjuvant TACE was associated with higher 1-, 3-, and 5-year OS rates (P=0.033 and P=0.034, respectively) and lower corresponding recurrence rates (P=0.024 and P=0.023, respectively).

Conclusions

Among the ICC-MVI patients undergoing curative-intent PH, only those have elevated CA19-9 or who did not undergo lymphadenectomy might be suitable for adjuvant TACE.

Toll-like receptor 3 expression in myeloid cells is essential for efficient regeneration after acute pancreatitis in mice

Stringent regulation of the inflammatory response is crucial for normal tissue regeneration. Here, we analyzed the role of Toll-like receptor 3 (TLR3) in pancreatic regeneration after acute pancreatitis (AP). AP was induced by caerulein treatment in mice with global TLR3 deficiency (TLR3^OFF ) or in mice re-expressing TLR3 exclusively in the myeloid cell lineage (TLR3^Mye ). Compared to WT mice, TLR3^OFF mice had a markedly increased formation of acinar-to-ductal metaplasia (ADM) that persisted until day 7 after initiation of AP. Pancreatic tissue of WT mice was completely regenerated after 5 days with no detectable ADM structures. The enhancing effect of TLR3-deficiency on ADM formation was closely linked with an increased and prolonged accumulation of macrophages in pancreata of TLR3^OFF mice. Importantly, the phenotype of TLR3^OFF mice was rescued in TLR3^Mye mice, demonstrating the causative role of myeloid cell selective TLR3 signaling. Moreover, in vitro stimulation of macrophages through TLR3 initiated cell death by a caspase-8-associated mechanism. Therefore, these findings provide evidence that TLR3 signaling in myeloid cells is sufficient to limit inflammation and ADM formation and to promote regeneration after AP. Notably, resolution of inflammation after AP was associated with macrophage sensitivity to TLR3-mediated cell death.

Serum keratin 19 (CYFRA21-1) links ductular reaction with portal hypertension and outcome of various advanced liver diseases

BACKGROUND

Keratins (Ks) represent tissue-specific proteins. K18 is produced in hepatocytes while K19, the most widely used ductular reaction (DR) marker, is found in cholangiocytes and hepatic progenitor cells. K18-based serum fragments are commonly used liver disease predictors, while K19-based serum fragments detected through CYFRA21-1 are established tumor but not liver disease markers yet. Since DR reflects the severity of the underlying liver disease, we systematically evaluated the usefulness of CYFRA21-1 in different liver disease severities and etiologies.

METHODS

Hepatic expression of ductular keratins (K7/K19/K23) was analyzed in 57 patients with chronic liver disease (cohort i). Serum CYFRA21-1 levels were measured in 333 Austrians with advanced chronic liver disease (ACLD) of various etiologies undergoing hepatic venous pressure gradient (HVPG) measurement (cohort ii), 231 French patients with alcoholic cirrhosis (cohort iii), and 280 hospitalized Germans with decompensated cirrhosis of various etiologies (cohort iv).

RESULTS

(i) Hepatic K19 levels were comparable among F0-F3 fibrosis stages, but increased in cirrhosis. Hepatic K19 mRNA strongly correlated with the levels of other DR-specific keratins. (ii) In ACLD, increased serum CYFRA21-1 associated with the presence of clinically significant portal hypertension (CSPH; HVPG ≥ 10 mmHg) (OR = 5.87 [2.95-11.68]) and mortality (HR = 3.02 [1.78-5.13]; median follow-up 22 months). (iii) In alcoholic cirrhosis, elevated serum CYFRA21-1 indicated increased risk of death/liver transplantation (HR = 2.59 [1.64-4.09]) and of HCC (HR = 1.74 [1.02-2.96]) over the long term (median follow-up 73 months). (iv) In decompensated cirrhosis, higher serum CYFRA21-1 predicted 90-day mortality (HR = 2.97 [1.92-4.60]) with a moderate accuracy (AUROC 0.64), independently from established prognostic scores.

CONCLUSIONS

Hepatic K19 mRNA and serum CYFRA21-1 levels rise in cirrhosis. Increased CYFRA21-1 levels associate with the presence of CSPH and reliably indicate mortality in the short and long term independently of conventional liver biochemistry markers or scoring systems. Hence, the widely available serum CYFRA21-1 constitutes a novel, DR-related marker with prognostic implications in patients with different settings of advanced liver disease.

How to Cope with Big Data in Functional Analysis of the Esophagus

Introduction

Esophageal motility disorders have a severe impact on patients' quality of life. While high-resolution manometry (HRM) is the gold standard in the diagnosis of esophageal motility disorders, intermittently occurring muscular deficiencies often remain undiscovered if they do not lead to an intense level of discomfort or cause suffering in patients. Ambulatory long-term HRM allows us to study the circadian (dys)function of the esophagus in a unique way. With the prolonged examination period of 24 h, however, there is an immense increase in data which requires personnel and time for evaluation not available in clinical routine. Artificial intelligence (AI) might contribute here by performing an autonomous analysis.

Methods

On the basis of 40 previously performed and manually tagged long-term HRM in patients with suspected temporary esophageal motility disorders, we implemented a supervised machine learning algorithm for automated swallow detection and classification.

Results

For a set of 24 h of long-term HRM by means of this algorithm, the evaluation time could be reduced from 3 days to a core evaluation time of 11 min for automated swallow detection and clustering plus an additional 10-20 min of evaluation time, depending on the complexity and diversity of motility disorders in the examined patient. In 12.5% of patients with suggested esophageal motility disorders, AI-enabled long-term HRM was able to reveal new and relevant findings for subsequent therapy.

Conclusion

This new approach paves the way to the clinical use of long-term HRM in patients with temporary esophageal motility disorders and might serve as an ideal and clinically relevant application of AI.

Survival data on timing of resection of liver metastases in colorectal cancer patients

Between 2007 and 2016, 140 consecutive patients who underwent resection of colorectal cancer with simultaneous liver metastases at a single university hospital were retrospectively analysed. In order to gather information regarding potential survival differences for n = 68 simultaneous versus n = 72 staged resections of the colorectal primary tumor and the liver metastases, Clinical, histopathological, serological, and survival data were compared for those two patient groups. The rate of simultaneous tumor resections increased from approximately 25% in 2007 to >75% in 2016. There was no difference in tumor specific survival for patients with simultaneous vs. staged resection (p = 0.631). This effect continued after excluding patients with extrahepatic metastases (p = 0.440). Further, neoadjuvant treatment did not lead to differences in the tumor-specific survival (p = 0.123). Factors associated with an increased tumor-specific survival were low ASA score (p < 0.001), low number of tumor-affected lymph nodes (p < 0.001), histological grading G1/2 (p = 0.001), and a low number of liver metastases (p = 0.044). There was no significant survival difference for the primary tumor stage (pT), the Clavien-Dindo complication rate, the resection status (R0), and minor versus major hepatectomies.

Simultaneous Versus Staged Resection of Colorectal Cancer Liver Metastasis: A Retrospective Single-Center Study

BACKGROUND

For patients with colorectal cancer and synchronous liver metastasis, either a simultaneous, or a two-staged resection of the primary tumor and the liver metastases is possible. There are currently no guidelines preferring one approach to the other.

MATERIAL AND METHODS

Consecutive patients who underwent hepatic resection at our university hospital from 2007-2016 were included. Clinical, histopathologic, serologic, and survival data were analyzed. The primary end point was tumor-specific survival for patients with simultaneous versus staged resections.

RESULTS

Of all 140 patients, 68 underwent simultaneous resection and 72 underwent staged resection. The characteristics of both groups were comparable. Patients with simultaneous resections had a shorter duration of cumulative operation time (299 versus 460 min; P = 0.003) and a shorter cumulative length of hospital stay (23 versus 43 d; P = 0.002). Perioperative mortality (P = 0.257) did not differ significantly; however, patients with simultaneous resections had higher rates of grade 2 complications according to Clavien-Dindo (P < 0.001). Tumor-specific 1-y survival was 85 ± 5% for simultaneous and 83 ± 5% for staged resection (P = 0.631). On multivariable analysis, pT4 (P = 0.038), pN3 (P = 0.003), and G3/4 (P = 0.041) of the primary tumor and postoperative complications (Clavien-Dindo 3/4/5, P = 0.003) were poor prognostic factors regarding tumor-specific survival.

CONCLUSIONS

This is one of the largest and most thoroughly documented retrospective single-center studies of consecutive patients with synchronous hepatic metastases. Simultaneous resection of colorectal cancer together with hepatic metastases is a safe procedure in selected patients and does not have a significant influence on long-term survival.

TLR3 promotes hepatocyte proliferation after partial hepatectomy by stimulating uPA expression and the release of tissue-bound HGF

TLR3 is implicated in anti-viral immune responses, but may also act as a sensor of tissue damage in the absence of infection. Here, we provide evidence for an essential role of TLR3 in liver regeneration after an acute loss of tissue due to partial hepatectomy. Mice lacking TLR3 had a severe and sustained defect in the restoration of liver tissue with reduced liver-to-body weight ratios even after an extended recovery period of 2 weeks. Hepatocyte cell cycle progression into S phase was impaired in TLR3-deficient mice. Mechanistic analyses revealed that TLR3-deficient mice had markedly reduced systemic levels of active HGF, but had increased amounts of inactive tissue-bound HGF. Importantly, expression of uPA, which orchestrates the processing and release of HGF from the hepatic extracellular matrix, was reduced in regenerating livers of TLR3-deficient mice. In addition, expression of the HGF maturation factor HGFAC was transiently diminished in TLR3-deficient mice. In vitro, engagement of TLR3 directly stimulated expression of uPA by hepatic stellate cells. Thus, TLR3 supports liver regeneration through upregulation of uPA, which promotes the release of preformed HGF from extracellular matrix stores.

The CGRP receptor component RAMP1 links sensory innervation with YAP activity in the regenerating liver

The effectiveness of liver regeneration limits surgical therapies of hepatic disorders and determines patient outcome. Here, we investigated the role of the neuropeptide calcitonin gene-related peptide (CGRP) for liver regeneration after acute or chronic injury. Mice deficient for the CGRP receptor component receptor activity-modifying protein 1 (RAMP1) were subjected to a 70% partial hepatectomy or repeated intraperitoneal injections of carbon tetrachloride. RAMP1 deficiency severely impaired recovery of organ mass and hepatocyte proliferation after both acute and chronic liver injury. Mechanistically, protein expression of the transcriptional coactivators Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) was decreased in regenerating livers of RAMP1-deficient mice. Lack of RAMP1 was associated with hyperphosphorylation of YAP on Ser127 and Ser397, which regulates YAP functional activity and protein levels. Consequently, expression of various YAP-controlled cell cycle regulators and hepatocyte proliferation were severely reduced in the absence of RAMP1. In vitro, CGRP treatment caused increased YAP protein expression and a concomitant decline of YAP phosphorylation in liver tissue slice cultures of mouse and human origin and in primary human hepatocytes. Thus, our results indicate that sensory nerves represent a crucial control element of liver regeneration after acute and chronic injury acting through the CGRP-RAMP1 pathway, which stimulates YAP/TAZ expression and activity.

Modifications of the AJCC 8th edition staging system for intrahepatic cholangiocarcinoma and proposal for a new staging system by incorporating serum tumor markers

BACKGROUND

Several studies have noted that the discriminatory ability and stratification performance of the AJCC 8th edition staging system is not entirely satisfactory. We aimed to improve the American Joint Committee on Cancer (AJCC) 8th edition staging system for intrahepatic cholangiocarcinoma (ICC).

METHODS

A multicentric database from three Chinese mainland centers (n = 1601 patients) was used to modify the 8th edition staging system. This modified TNM (mTNM) staging system was then validated using the SEER database (n = 761 patients). A new TNM staging system, by incorporating serum tumor markers (TNMIS) into the mTNM staging system was then proposed.

RESULTS

The 8th edition staging system did not provide an adequate stratification of prognosis in the Chinese multicentric cohort. The mTNM staging system offered a better discriminatory capacity in the multicentric cohort than the original 8th edition. External validation in the SEER cohort showed that the mTNM staging system also had a good stratification performance. After further incorporating a serum marker stage into the mTNM staging, the TNMIS staging system was able to stratify prognosis even better.

CONCLUSION

The proposed mTNM staging system resulted in better stratification performance and the TNMIS staging system provided even more accurate prognostic classification than the conventional TNM system.

Angiocrine Hepatocyte Growth Factor Signaling Controls Physiological Organ and Body Size and Dynamic Hepatocyte Proliferation to Prevent Liver Damage during Regeneration

Liver sinusoidal endothelial cells (LSECs) control organ functions, metabolism, and development through the secretion of angiokines. LSECs express hepatocyte growth factor (Hgf), which is involved in prenatal development, metabolic homeostasis, and liver regeneration. This study aimed to elucidate the precise contribution of LSEC-derived Hgf in physiological homeostasis and liver regeneration. Stab2-iCre^tg/wt;Hgf^fl/fl (Hgf^ΔLSEC) mice were generated to abrogate Hgf expression selectively in LSECs from early fetal development onwards, to study global development, metabolic and endothelial zonation, and organ functions as well as liver regeneration in response to 70% partial hepatectomy (PH). Although zonation and liver/body weight ratios were not altered, total body weight and total liver weight were reduced in Hgf^ΔLSEC. Necrotic organ damage was more marked in Hgf^ΔLSEC mice, and regeneration was delayed 72 hours after PH. This was associated with decreased hepatocyte proliferation at 48 hours after PH. Molecularly, Hgf^ΔLSEC mice showed down-regulation of Hgf/c-Met signaling and decreased expression of Deptor in hepatocytes. In vitro knockdown of Deptor was associated with decreased proliferation. Therefore, angiocrine Hgf controls hepatocyte proliferation and susceptibility to necrosis after partial hepatectomy via the Hgf/c-Met axis involving Deptor to prevent excessive organ damage.

Oncogenic Akt-FOXO3 loop favors tumor-promoting modes and enhances oxidative damage-associated hepatocellular carcinogenesis

BACKGROUND

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer, accounting for 80-90% of cases. Mutations are commonly found in the signaling regulating the PI3K/Akt pathway, leading to oncogenic cell proliferation and survival. Key transcription factors that are negatively regulated downstream of PI3K/Akt are members of the forkhead box O family (FOXO). FOXOs were initially considered as tumor suppressors by inducing cell cycle arrest and apoptosis. However, there is increasing evidence showing that FOXOs, especially FOXO3, can support tumorigenesis.

METHODS

To understand the roles of FOXO3 in liver tumorigenesis and hepatocarcinogenesis, we analyzed HCC patient specimens and also established a doxycycline-regulated transgenic mouse model with hepatocyte-specific FOXO3 expression in a constitutively active form.

RESULTS

We found that FOXO3 protein is significantly overexpressed and activated in livers of HCC patients. Hepatic activation of FOXO3 induced extensive hepatic damage and elevated gene expression of several HCC-associated factors. Furthermore, FOXO3 expression enhanced hepatotoxicin-induced tumorigenesis. Mechanistically, FOXO3 activation caused oxidative stress and DNA damage and triggered positive feedback-loop for Akt activation as well as mTORC2 activation. Interestingly, FOXO3 activated not only reactive oxygen species (ROS)-promoting pathways, but also ROS-eliminating systems, which can be associated with the activation of the pentose phosphate pathway.

CONCLUSIONS

FOXO3 is a master regulator of ROS in a 'carrot and stick' manner; on one side avoiding cellular crisis while also supporting hepatocellular carcinogenesis. Clinically, we suggest analyzing FOXO3 activation status in patients with liver diseases, in addition to PI3K/Akt signaling. Personalized therapy of FOXO3 inhibition may be a reasonable, depending on the activation status of FOXO3.

Exosome-transmitted p120-catenin suppresses hepatocellular carcinoma progression via STAT3 pathways

Hepatocellular carcinoma (HCC) is a fatal disease with increasing morbidity and poor prognosis due to surgical recurrence and metastasis. Moreover, the molecular mechanism of HCC progression remains unclear. Although the role of p120-catenin (p120ctn) in liver cancer is well studied, the effects of secreted p120ctn transported by exosomes are less understood. Here, we show that p120ctn in exosomes secreted from liver cancer cells suppresses HCC cell proliferation and metastasis and expansion of liver cancer stem cells (CSCs). Mechanically, exosome p120ctn inhibits HCC cell progression via the STAT3 pathway, and the STAT3 inhibitor S3I-201 abolishes the observed effects on growth, metastasis, and self-renewal ability between exosome p120ctn-treated HCC cells and control cells. Taken together, we propose that p120ctn-containing exosomes derived from cancer cells inhibit the progression of liver cancer and may offer a new therapeutic strategy.

The neuropeptide receptor subunit RAMP1 constrains the innate immune response during acute pancreatitis in mice

OBJECTIVES

The importance of the Calcitonin-gene-related-peptide-pathway (CGRP) as neuronal modulator of innate immune responses in mice has been previously demonstrated. The CGRP-receptor is composed of two subunits: the receptor-activity-modifying-protein-1 (RAMP1) and the calcitonin-receptor-like-receptor (CLR). CGRP can influence immune cells and their capacity of producing inflammatory cytokines. Using a RAMP1 knockout-mouse (RAMP1^-/-) we examined the role of the CGRP-receptor in the acute-phase of cerulein-induced pancreatitis.

METHODS

Hourly cerulein-injections for a period of 8 h in RAMP1^-/- and wild-type mice were performed. To compare severity and extent of inflammation in RAMP1^-/- and wild-type mice, histological analyses were done and cytokine levels were assessed using qRT-PCR 8 h, 24 h, 2 days, and 7 days post-cerulein-treatment. Furthermore, serum activities of LDH and lipase were determined.

RESULTS

After 8 h RAMP1^-/- mice showed a higher pancreas-to-body-weight-ratio, increased tissue edema and immune cell infiltration with higher amount of F4/80-positive cells as compared to wild-type mice. Overall infiltration of immune cells at 24 h was increased in RAMP1^-/- mice and composed predominantly of MPO-positive neutrophils. In addition, after 24 h RAMP1^-/- mice presented a higher pancreas-to-body-weight-ratio, higher expression of Ccl3, Il6, and Il1b and increased number of cleaved caspase 3 positive cells. Serum lipase correlated with the extent of tissue damage in RAMP1^-/- compared to wild-type mice 24 h post-cerulein treatment.

CONCLUSION

Mice lacking RAMP1 showed increased inflammation, tissue edema, and pancreas injury particularly in the early phase of acute pancreatitis. This study highlights the essential role of CGRP for dampening the innate immune response in acute pancreatitis.

Multiple intestinal intussusceptions caused by highly impaired gastrointestinal motility in a patient with chronic cannabis consumption

Since the therapeutic use of cannabis and its derivatives is currently rising, the adverse effects of cannabis and cannabinoids are of special interest. However little is known about the possible effects of long-term use of cannabis on the gastrointestinal motility. Herewith we describe the case of a patient with a rare severe form of intestinal intussusception following long-term cannabis consumption. The case shall raise awareness of possible life threatening complications of the use of cannabis and its derivates.

24-hour monitoring of transient lower esophageal sphincter relaxation events by long-term high-resolution impedance manometry in normal volunteers: The "mirror phenomenon"

BACKGROUND

The aim of this study was to investigate the frequency and circadian changes in transient lower esophageal sphincter relaxations (TLESRs) in normal volunteers using 24-hour high-resolution impedance manometry (HRIM).

METHODS

Fifteen volunteers underwent HRIM. TLESRs were recorded during the mealtime, 2-hour postprandial, daytime, and supine periods. The catheter was firmly secured to the nose, and subjects went home, ate normal meals, and continued routine daily activities.

KEY RESULTS

Successful recordings were obtained in 11 volunteers. Overall, 1083 TLESRs were documented; the average occurrence was 4.2/h, and the duration was 21.0 ± 5.2 seconds. The majority of the TLESRs occurred during the 2-hour postprandial (42.7%) and daytime (31.5%) periods, while 10.2% and 15.6% occurred during the mealtime and supine periods, respectively. Eight hundred and eighty-six (81.8%) TLESRs were associated with reflux. Overall, 25.5% of TLESRs were preceded by partial secondary peristalsis (PSP), while 74.5% were preceded by nothing. Terminating events included primary peristalsis (PP; 40.3%), PSP (42.8%), full secondary peristalsis (FSP; 8.2%), or nothing (8.7%). Both preceding and terminating events periodically changed throughout the four periods. One hundred and twelve (10.3%) TLESRs with both preceding and terminating events of PSP, presenting as a "mirror phenomenon," were documented. The majority of these TLESRs occurred during the supine (70.5%).

CONCLUSIONS & INFERENCES

Transient lower esophageal sphincter relaxations are common physiological motor events in normal volunteers; these events have certain circadian rhythms, as do the events that precede and terminate TLESR events. A special "mirror phenomenon" is observed when both the preceding and terminating events are PSP.

Brg1 promotes liver regeneration after partial hepatectomy via regulation of cell cycle

Brahma-related gene 1 (Brg1), a catalytic subunit of the SWItch/Sucrose Non-Fermentable (SWI/SNF) complex, is known to be involved in proliferative cell processes. Liver regeneration is initiated spontaneously after injury and leads to a strong proliferative response. In this study, a hepatocyte-specific Brg1 gene knockout mouse model was used to analyse the role of Brg1 in liver regeneration by performing a 70% partial hepatectomy (PH). After PH, Brg1 was significantly upregulated in wildtype mice. Mice with hepatocyte-specific Brg1 gene knockout showed a significantly lower liver to body weight ratio 48 h post-PH concomitant with a lower hepatocellular proliferation rate compared to wildtype mice. RNA sequencing demonstrated that Brg1 controlled hepatocyte proliferation through the regulation of the p53 pathway and several cell cycle genes. The data of this study reveal a crucial role of Brg1 for liver regeneration by promoting hepatocellular proliferation through modulation of cell cycle genes and, thus, identify Brg1 as potential target for therapeutic approaches.

Long non-coding RNA THOR promotes liver cancer stem cells expansion via β-catenin pathway

Hepatocellular carcinoma (HCC) is a highly aggressive liver tumor containing cancer stem cells (CSCs), which participate in tumor invasion, therapeutic resistance, and tumor relapse leading to poor outcome and limited therapeutic options. Recently, a novel lncRNA, THOR (testis-associated highly conserved oncogenic long non-coding RNA), was characterized in human cancers and shown to exhibit an oncogenic role. However, the role of THOR in liver cancer stem cells (CSCs) remains obscure. Herein, we observed high expression of THOR in chemoresistant hepatocellular carcinomas (HCCs). A remarkable increase of THOR expression in OV6 or EpCAM-positive liver CSCs as well as in CSC-enriched hepatoma spheres. Interference THOR suppressed liver CSC expansion by inhibiting the dedifferentiation of hepatoma cells and decreasing the self-renewal ability of liver CSCs. Mechanistically, we found β-catenin as the downstream of THOR in HCC cells. The special β-catenin inhibitor FH535 abolished the discrepancy in liver CSC proportion and the self-renewal capacity between THOR knockdown HCC cells and control cells, which further confirmed that β-catenin was required in THOR promoted liver CSCs expansion. Moreover, interference THOR hepatoma cells were more sensitive to sorafenib treatment, indicates that HCC patients with low THOR expression may benefit from sorafenib treatment. Collectively, THOR was upregulated in liver CSCs and could promote HCC cells dedifferentiation and liver CSCs expansion by targeting β-catenin signaling.

Cytosolic nucleic acid sensors of the innate immune system promote liver regeneration after partial hepatectomy

Stimulation of cytosolic nucleic acid sensors of innate immunity by pathogen-derived nucleic acids is important for antimicrobial defence, but stimulation through self-derived nucleic acids may contribute to autoinflammation and cancer. DNA sensing in the cytosol requires the stimulator of interferon genes (STING), while cytosolic RNA sensors use mitochondrial antiviral-signalling protein (MAVS). In a murine model of two-thirds hepatectomy, combined deficiency of MAVS and STING resulted in strongly impaired hepatocyte proliferation and delayed recovery of liver mass. Whereas lack of MAVS and STING did not influence upregulation of the G₁-phase cyclins D1 and E1, it substantially reduced the hyperphosphorylation of retinoblastoma protein, attenuated the activation of cyclin-dependent kinase (CDK)-2, delayed upregulation of CDK1 and cyclins A2 and B1, and impaired S-phase entry of hepatocytes. Mechanistically, lack of cytosolic nucleic acid sensors strongly upregulated the anti-proliferative mediators TGF-β2 and activin A, which was associated with an increased expression of the cell cycle inhibitors p15 and p21. Partial hepatectomy was followed by the release of exosomes with abundant nucleic acid cargo, which may provide ligands for the MAVS and STING pathways. Together, these findings identify a previously unrecognised function of cytosolic nucleic acid sensors of innate immunity for promoting liver regeneration.

Long non-coding RNA THOR promotes cell proliferation and metastasis in hepatocellular carcinoma

Long non-coding RNAs (lncRNAs) have been demonstrated to be involved in the development and progression of multiple cancers by previous studies. Recently, a novel lncRNA, THOR (testis-associated highly conserved oncogenic long non-coding RNA), was characterized in human cancers and shown to exhibit an oncogenic role. However, the role of THOR in hepatocellular carcinoma (HCC) is still unclear. In this study, we found that THOR was relatively highly expressed in human HCC tissues and cell lines. Notably, high THOR expression was associated with worse prognosis. THOR depletion resulted in significant inhibition of the growth and metastasis of HCC cells. Mechanistically, THOR drives HCC cell progression via the PTEN/AKT pathway. Moreover, the specific PI3-K inhibitor LY294002 abolished the discrepancy in the growth and metastatic capacity between THOR-silenced HCC cells and control cells, which further confirmed that AKT was required in THOR-driven HCC cell growth and metastasis. Taken together, our results suggest that THOR could promote HCC cell growth and metastasis by amplifying PTEN/AKT signaling and may be a new therapeutic target and predictive factor for HCC.

Hsp72 protects against liver injury via attenuation of hepatocellular death, oxidative stress, and JNK signaling

BACKGROUND & AIMS

Heat shock protein (Hsp) 72 is a molecular chaperone that has broad cytoprotective functions and is upregulated in response to stress. To determine its hepatic functions, we studied its expression in human liver disorders and its biological significance in newly generated transgenic animals.

METHODS

Double transgenic mice overexpressing Hsp72 (gene Hspa1a) under the control of a tissue-specific tetracycline-inducible system (Hsp72-LAP mice) were produced. Acute liver injury was induced by a single injection of acetaminophen (APAP). Feeding with either a methionine choline-deficient (MCD; 8 weeks) or a 3,5-diethoxycarbonyl-1,4-dihydrocollidine-supplemented diet (DDC; 12 weeks) was used to induce lipotoxic injury and Mallory-Denk body (MDB) formation, respectively. Primary hepatocytes were treated with palmitic acid.

RESULTS

Patients with non-alcoholic steatohepatitis and chronic hepatitis C infection displayed elevated HSP72 levels. These levels increased with the extent of hepatic inflammation and HSP72 expression was induced after treatment with either interleukin (IL)-1β or IL-6. Hsp72-LAP mice exhibited robust, hepatocyte-specific Hsp72 overexpression. Primary hepatocytes from these animals were more resistant to isolation-induced stress and Hsp72-LAP mice displayed lower levels of hepatic injury in vivo. Mice overexpressing Hsp72 had fewer APAP protein adducts and were protected from oxidative stress and APAP-/MCD-induced cell death. Hsp72-LAP mice and/or hepatocytes displayed significantly attenuated Jnk activation. Overexpression of Hsp72 did not affect steatosis or the extent of MDB formation.

CONCLUSIONS

Our results demonstrate that HSP72 induction occurs in human liver disease, thus, HSP72 represents an attractive therapeutic target owing to its broad hepatoprotective functions.

LAY SUMMARY

HSP72 constitutes a stress-inducible, protective protein. Our data demonstrate that it is upregulated in patients with chronic hepatitis C and non-alcoholic steatohepatitis. Moreover, Hsp72-overexpressing mice are protected from various forms of liver stress.

A Dual Role of Caspase-8 in Triggering and Sensing Proliferation-Associated DNA Damage, a Key Determinant of Liver Cancer Development

Concomitant hepatocyte apoptosis and regeneration is a hallmark of chronic liver diseases (CLDs) predisposing to hepatocellular carcinoma (HCC). Here, we mechanistically link caspase-8-dependent apoptosis to HCC development via proliferation- and replication-associated DNA damage. Proliferation-associated replication stress, DNA damage, and genetic instability are detectable in CLDs before any neoplastic changes occur. Accumulated levels of hepatocyte apoptosis determine and predict subsequent hepatocarcinogenesis. Proliferation-associated DNA damage is sensed by a complex comprising caspase-8, FADD, c-FLIP, and a kinase-dependent function of RIPK1. This platform requires a non-apoptotic function of caspase-8, but no caspase-3 or caspase-8 cleavage. It may represent a DNA damage-sensing mechanism in hepatocytes that can act via JNK and subsequent phosphorylation of the histone variant H2AX.

Endoluminal Sphincter Augmentation with the MUSE™ System and GERDX™ System in the Treatment of Gastroesophageal Reflux Disease: A New Impact?

To bridge the gap between the long-term intake of proton pump inhibitors (PPIs) and the potential risks of laparoscopic fundoplication, a number of endoscopic procedures for the treatment of gastro-esophageal reflux disease (GERD) have been developed over the past 30 years. Because of the minimally invasive approach, short operative time, and efficacy in selected patients, endoluminal sphincter augmentation appears to be highly attractive. However, most early devices have proven to be unsafe or failed to provide long-term symptom relief. Accordingly, products for endoluminal sphincter augmentation have undergone several modifications to achieve an increased lower esophageal sphincter (LES) baseline pressure to re-establish the LES as an efficacious anti-reflux barrier. This paper reviews and discusses the two latest products for endoluminal sphincter augmentation, the MUSE™ device (Medigus, Ltd., Omer, Israel) and the GERDX™ system (G-SURG GmbH, Seeon-Seebruck, Germany). While the currently available literature has proven their effectiveness in principle, long-term results are lacking. Further studies and developments are necessary to determine whether these two new devices will truly impact GERD therapy.

BRG1 promotes hepatocarcinogenesis by regulating proliferation and invasiveness

The chromatin remodeler complex SWI/SNF plays an important role in physiological and pathological processes. Brahma related gene 1(BRG1), a catalytic subunit of the SWI/SNF complex, is known to be mutated in hepatocellular carcinoma (HCC). However, its role in HCC remains unclear. Here, we investigate the role of BRG1 on cell growth and invasiveness as well as its effect on the expression of putative target genes. Expression of BRG1 was examined in human liver tissue samples and in HCC cell lines. In addition, BRG1 was silenced in human HCC cell lines to analyse cell growth and invasiveness by growth curves, colony formation assay, invasion assay and the expression of putative target genes. BRG1 was found to be significantly increased in HCC samples compared to non-HCC samples. In addition, a declined proliferation rate of BRG1-silenced human HCC cell lines was associated with a decrease of expression of cyclin family members. In line with a decreased invasiveness of BRG1-siRNA-treated human HCC cell lines, down-regulation of MMP7 was detected. These results support the hypothesis that overexpression of BRG1 increases cell growth and invasiveness in HCC. Furthermore, the data highlight cyclin B, E and MMP7 to be associated with BRG1 during hepatocarcinogenesis.

Kupffer Cell-Derived Tnf Triggers Cholangiocellular Tumorigenesis through JNK due to Chronic Mitochondrial Dysfunction and ROS

Intrahepatic cholangiocarcinoma (ICC) is a highly malignant, heterogeneous cancer with poor treatment options. We found that mitochondrial dysfunction and oxidative stress trigger a niche favoring cholangiocellular overgrowth and tumorigenesis. Liver damage, reactive oxygen species (ROS) and paracrine tumor necrosis factor (Tnf) from Kupffer cells caused JNK-mediated cholangiocellular proliferation and oncogenic transformation. Anti-oxidant treatment, Kupffer cell depletion, Tnfr1 deletion, or JNK inhibition reduced cholangiocellular pre-neoplastic lesions. Liver-specific JNK1/2 deletion led to tumor reduction and enhanced survival in Akt/Notch- or p53/Kras-induced ICC models. In human ICC, high Tnf expression near ICC lesions, cholangiocellular JNK-phosphorylation, and ROS accumulation in surrounding hepatocytes are present. Thus, Kupffer cell-derived Tnf favors cholangiocellular proliferation/differentiation and carcinogenesis. Targeting the ROS/Tnf/JNK axis may provide opportunities for ICC therapy.

[Surgical treatment of esophageal diverticula : Endoscopic or open approach?]

Esophageal diverticula are comparatively rare. The majority are Zenker's diverticula but parabronchial and epiphrenic diverticula can also occur. Parabronchial diverticula are of low clinical relevance, whereas Zenker's and epiphrenic diverticula both belong to the group of pulsion diverticula and can become clinically apparent by dysphagia and regurgitation. Approximately 100 years after the first surgical treatment, peroral approaches (e.g. stapler dissection and flexible endoscopic diverticulotomy) have now achieved a certain level of importance. Both approaches are less invasive than the open approach but are evidently more prone to recurrences. Accordingly, traditional open diverticulectomy with cervical myotomy should be recommended to patients with a reasonable life expectancy and an acceptable operative risk. This holds particularly true for Brombart stages I-III of the disease, as complete myotomy cannot be achieved via the peroral access. The classical surgical treatment of epiphrenic diverticula is open or laparoscopic/thoracoscopic diverticulectomy with distal myotomy, mostly combined with an anterior partial fundoplication; however, the leakage rate is high and several alternative options are currently being evaluated.

Atypical flat lesions derive from pancreatic acinar cells

OBJECTIVES

Pancreatic ductal adenocarcinoma (PDAC) is thought to derive from different precursor lesions including the recently identified atypical flat lesions (AFL). While all precursor lesions and PDAC share ductal characteristics, there is an ongoing debate about the cellular origin of the different PDAC precursor lesions. In particular, pancreatic acinar cells have previously been shown to display a remarkable plasticity being able to undergo ductal dedifferentiation in the context of oncogenic stimuli.

METHODS

Histological analyses were performed in a murine PDAC model that specifically expresses oncogenic Kras in adult pancreatic acinar cells. Occurrence, characterization, and lineage tracing of AFLs were investigated.

RESULTS

Upon expression of oncogenic Kras in adult pancreatic acinar cells, AFLs with typical morphology and expression profile arise. Lineage tracing confirmed that the AFLs were of acinar origin.

CONCLUSIONS

Using a murine PDAC model, this study identifies pancreatic acinar cells as a cellular source for AFLs.

Impact of NKT Cells and LFA-1 on Liver Regeneration under Subseptic Conditions

Background

Activation of the immune system in terms of subseptic conditions during liver regeneration is of paramount clinical importance. However, little is known about molecular mechanisms and their mediators that control hepatocyte proliferation. We sought to determine the functional role of immune cells, especially NKT cells, in response to partial hepatectomy (PH), and to uncover the impact of the integrin lymphocyte function-associated antigen-1 (LFA-1) on liver regeneration in a subseptic setting.

Methods

Wild-type (WT) and LFA-1^-/- mice underwent a 2/3 PH and low-dose lipopolysaccharid (LPS) application. Hepatocyte proliferation, immune cell infiltration, and cytokine profile in the liver parenchyma were determined.

Results

Low-dose LPS application after PH results in a significant delay of liver regeneration between 48h and 72h, which is associated with a reduced number of CD3⁺ cells within the regenerating liver. In absence of LFA-1, an impaired regenerative capacity was observed under low-dose LPS application. Analysis of different leukocyte subpopulations showed less CD3⁺NK1.1⁺ NKT cells in the liver parenchyma of LFA-1^-/- mice after PH and LPS application compared to WT controls, while CD3^-NK1.1⁺ NK cells markedly increased. Concordantly with this observation, lower levels of NKT cell related cytokines IL-12 and IL-23 were expressed in the regenerating liver of LFA-1^-/- mice, while the expression of NK cell-associated CCL5 and IL-10 was increased compared to WT mice.

Conclusion

A subseptic situation negatively alters hepatocyte proliferation. Within this scenario, we suggest an important impact of NKT cells and postulate a critical function for LFA-1 during processes of liver regeneration.

ZnO quantum dots modified bioactive glass nanoparticles with pH-sensitive release of Zn ions, fluorescence, antibacterial and osteogenic properties

Zinc (Zn)-containing materials have osteogenic and antibacterial activities while bioactive glass nanoparticles (BGN) show bone-bonding ability, as well as osteoconductive and osteoinductive properties. Zn-containing BGN are therefore considered to be promising materials for various biomedical applications, particularly in bone regeneration. In this study, we report a convenient method to prepare Zn-containing BGN by coating ZnO quantum dots (QDs) on BGN via electrostatic interactions. The synthesized ZnO-BGN nanocomposite particles are spherical and highly dispersed, and exhibit a unique fluorescence behavior under UV excitation, emitting three wavelengths in the violet, blue and green range. ZnO-BGN showed apatite-forming ability upon immersion in simulated body fluid, but their apatite formation was delayed compared to BGN. Interestingly, ZnO-BGN showed a rapid release of Zn ions at pH 4 but a far slower release at pH 7.4. ZnO-BGN also exhibited antibacterial effects on both Gram-positive and Gram-negative bacteria at the concentrations of 1, 0.1, and 0.01 mg mL^-1. Higher concentrations could lead to stronger antibacterial effects. The LDH and live/dead assays indicated that ZnO-BGN had no significant cytotoxicity towards human mesenchymal stem cells (hMSC) at concentration of 0.1 and 0.01 mg mL^-1, but ZnO-BGN inhibited the relative proliferation of hMSC compared to BGN and the control according to the MTT assay. Notably ZnO-BGN improved the osteogenic differentiation of hMSC as indicated by the determination of the alkaline phosphatase activity. In conclusion, coating quantum dots on BGN is a promising strategy to produce Zn-containing BGN. The synthesized ZnO-BGN are potential materials for bone regeneration, considering their apatite-forming ability, unique ion-release behavior, effective antibacterial activity, non-cytotoxicity, and osteogenic potential.