Ultra high frequency ultrasound enables real-time visualization of blood supply from chorioallantoic membrane to human autosomal dominant polycystic kidney tissue.

Ultra high frequency (UHF) ultrasound enables the visualization of very small structures that cannot be detected by conventional ultrasound. The utilization of UHF imaging as a new imaging technique for the 3D-in-vivo chorioallantoic membrane (CAM) model can facilitate new insights into tissue perfusion and survival. Therefore, human renal cystic tissue was grafted onto the CAM and examined using UHF ultrasound imaging. Due to the unprecedented resolution of UHF ultrasound, it was possible to visualize microvessels, their development, and the formation of anastomoses. This enabled the observation of anastomoses between human and chicken vessels only 12 h after transplantation. These observations were validated by 3D reconstructions from a light sheet microscopy image stack, indocyanine green angiography, and histological analysis. Contrary to the assumption that the nutrient supply of the human cystic tissue and the gas exchange happens through diffusion from CAM vessels, this study shows that the vasculature of the human cystic tissue is directly connected to the blood vessels of the CAM and perfusion is established within a short period. Therefore, this in-vivo model combined with UHF imaging appears to be the ideal platform for studying the effects of intravenously applied therapeutics to inhibit renal cyst growth.

Intraoperative contrast-enhanced ultrasound has an outcome-relevant impact on surgery of primary and metastatic liver lesions.

PURPOSE: Complete resection of the affected tissue remains the best curative treatment option for liver-derived tumors and colorectal liver metastases. In addition to preoperative cross-sectional imaging, contrast-enhanced intraoperative ultrasound (CE-IOUS) plays a crucial role in the detection and localization of all liver lesions. However, its exact role is unclear. This study was designed to evaluate the clinical and oncological impact of using CE-IOUS in the surgical treatment of these diseases. MATERIALS AND METHODS: Over the three-year study period, 206 patients with primary liver tumors and hepatic metastases were enrolled in this prospective, monocentric study to evaluate the impact of CE-IOUS in liver surgery. Secondary outcomes included comparing the sensitivity and specificity of CE-IOUS with existing preoperative imaging modalities and identifying preoperative parameters that could predict a strategic impact of CE-IOUS. In addition, the oncological significance of CE-IOUS was evaluated using a case-cohort design with a minimum follow-up of 18 months. RESULTS: CE-IOUS findings led to a change in surgical strategy in 34% of cases (n=70/206). The accuracy in cases with a major change could be confirmed histopathologically in 71.4% of cases (n=25/35). The impact could not be predicted using parameters assumed to be clinically relevant. An oncological benefit of a CE-IOUS adapted surgical approach was demonstrated in patients suffering from HCC and colorectal liver metastases. CONCLUSION: CE-IOUS may significantly increase R0 resection rates and should therefore be used routinely as an additional staging method, especially in complex liver surgery.

3D In Vivo Models for Translational Research on Pancreatic Cancer: The Chorioallantoic Membrane (CAM) Model.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with adverse outcomes that have barely improved over the last decade. About half of all patients present with metastasis at the time of diagnosis, and the 5-year overall survival rate across all stages is only 6%. Innovative in vivo research models are necessary to combat this cancer and to discover novel treatment strategies. The chorioallantoic membrane (CAM) model represents one 3D in vivo methodology that has been used in a large number of studies on different cancer types for over a century. This model is based on a membrane formed within fertilized chicken eggs that contain a dense network of blood vessels. Because of its high cost-efficiency, simplicity, and versatility, the CAM model appears to be a highly valuable research tool in the pursuit of gaining more in-depth insights into PDAC. A summary of the current literature on the usage of the CAM model for the investigation of PDAC was conducted and subdivided into angiogenesis, drug testing, modifications, personalized medicine, and further developments. On this comprehensive basis, further research should be conducted on PDAC in order to improve the abysmal prognosis of this malignant disease.

A 3D In Vivo Model for Studying Human Renal Cystic Tissue and Mouse Kidney Slices.

(1) Background: Autosomal dominant polycystic kidney disease (ADPKD) is a frequent monogenic disorder that leads to progressive renal cyst growth and renal failure. Strategies to inhibit cyst growth in non-human cyst models have often failed in clinical trials. There is a significant need for models that enable studies of human cyst growth and drug trials. (2) Methods: Renal tissue from ADPKD patients who received a nephrectomy as well as adult mouse kidney slices were cultured on a chorioallantoic membrane (CAM) for one week. The cyst volume was monitored by microscopic and CT-based applications. The weight and angiogenesis were quantified. Morphometric and histological analyses were performed after the removal of the tissues from the CAM. (3) Results: The mouse and human renal tissue mostly remained vital for about one week on the CAM. The growth of cystic tissue was evaluated using microscopic and CT-based volume measurements, which correlated with weight and an increase in angiogenesis, and was accompanied by cyst cell proliferation. (4) Conclusions: The CAM model might bridge the gap between animal studies and clinical trials of human cyst growth, and provide a drug-testing platform for the inhibition of cyst enlargement. Real-time analyses of mouse kidney tissue may provide insights into renal physiology and reduce the need for animal experiments.

The Effects of Analgesics on the Migration of Pancreatic Cancer Cells.

BACKGROUND/AIM: Adenocarcinoma of the pancreas is one of the most aggressive malignant diseases in humans. Characteristics of this tumour type are poor response to radiotherapy and chemotherapeutic agents as well as metastasis in the absence of an organ capsule. The best therapeutic option is surgical removal of the tumour followed by chemotherapy or radiotherapy. Yet, even after surgical R0-resection, the 5-year survival probability is only about 20% because of the high recurrence rate of this tumour and complications due to metastases. Furthermore, recent studies have shown that the perioperative period is a particularly vulnerable phase, during which tumour progression and metastasis may be facilitated. The effects of analgesics administered during the perioperative period are still unknown. The present work investigated the effects of analgesics on pancreatic cancer cell migration in vitro. MATERIALS AND METHODS: The migratory potential of pancreatic cancer cells was analysed using a Cell Migration Assay Kit with a Boyden chamber, in which cells migrate through a semi-permeable membrane under different stimuli. Cell concentration was measured by reading fluorescence (Ex/Em=530/590 nm) in a plate reader. RESULTS: Migration in PANC-1 pancreatic cancer cells was significantly decreased after 24 h stimulation with 100 µM of ropivacaine, 100 nM of sufentanil, 1,000 µM of ropivacaine and 1,000 nM of sufentanil. In the PaTu 8988t cell line, incubation with 10 µM of ropivacaine caused a slight but statistically significant increase in migration, whereas lidocaine, metamizole and paracetamol did not significantly affect migration. CONCLUSION: The risk of tumour progression and metastasis seems to be increased during major oncological surgical interventions. The recent advances in the molecular and biological understanding of pathogenesis of pancreatic cancer have not yet significantly improved patient outcome. Therefore, further studies are needed to identify the underlying mechanisms of this aggressive tumour and establish new therapeutic options for the future.

Positive Microbiological Cultures in the Respiratory Tract of High Model for End-Stage Liver Disease (MELD) Liver Transplant Recipients With and Without Pneumonia.

BACKGROUND: Pneumonia in liver transplant recipients is one of the most common infections in the early phase after transplantation. The diagnosis is based on clinical signs combined with positive microbiological samples taken from the lower respiratory tract. However, the role of bacterial colonization is not clear, nor is its association with pneumonia or its long-term consequences. The aim of this study was to investigate the association between positive microbiological findings and clinically relevant pneumonia and analyze different clinical and laboratory parameters for their association with pneumonia in liver transplant recipients. METHODS: This was a retrospective analysis of 266 adult orthotopic liver transplantations between January 2008 and December 2013. A multidisciplinary in-house specialist panel established and confirmed the diagnosis of clinically relevant pneumonia in microbiologically positive patients. RESULTS: Of the 266 transplantations analyzed, 54 patients (20%) showed microbiologically positive trachea-bronchial cultures during the first 21 days after liver transplantation. Of those 54 patients, 24 (44.4%) had pneumonia as rated by the multidisciplinary specialist panel. Presence of gram-negative Enterobacteriaceae (P = .013) and positive chest radiologic findings (P = .035) were associated with pneumonia in microbiological-positive patients. Although patients with pneumonia had the lowest long-term survival, those without pneumonia but with positive microbiological cultures had still worse survival compared with the Model for End-Stage Liver Disease-matched control group without positive cultures (P = .012). CONCLUSIONS: Gram-negative Enterobacteriaceae and positive radiologic findings were associated with pneumonia in liver transplant recipients with positive microbiological trachea-bronchial cultures. Recipients with bacterial colonization without pneumonia also showed decreased long-term survival.

Resection of oesophageal and oesophagogastric junction cancer liver metastases - a summary of current evidence.

PURPOSE: Metastatic oesophageal cancer is commonly considered as a palliative situation with a poor prognosis. However, there is increasing evidence that well-selected patients with a limited number of liver metastases (ECLM) may benefit from a multimodal approach including surgery. METHODS: A systematic review of the current literature for randomized trials, retrospective studies, and case series with patients undergoing hepatectomies for oesophageal and oesophagogastric junction cancer liver metastases was conducted up to the 31st of August 2021 using the MEDLINE (PubMed) and Cochrane Library databases. RESULTS: A total of 661 articles were identified. After removal of duplicates, 483 articles were screened, of which 11 met the inclusion criteria. The available literature suggests that ECLM resection in patients with liver oligometastatic disease may lead to improved survival and even long-term survival in some cases. The response to concomitant chemotherapy and liver resection seems to be of significance. Furthermore, a long disease-free interval in metachronous disease, low number of liver metastases, young age, and good overall performance status have been described as potential predictive markers of outcome for the resection of liver metastases. CONCLUSION: Surgery may be offered to carefully selected patients to potentially improve survival rates compared to palliative treatment approaches. Studies with standardized patient selection criteria and treatment protocols are required to further define the role for surgery in ECLM. In this context, particular consideration should be given to neoadjuvant treatment concepts including immunotherapies in stage IVB oesophageal and oesophagogastric junction cancer.

Evaluation of Screening Tests in Bavarian Healthcare Facilities during the Second Wave of the SARS-CoV-2 Pandemic.

Due to the lack of data on asymptomatic SARS-CoV-2-positive persons in healthcare institutions, they represent an inestimable risk. Therefore, the aim of the current study was to evaluate the first 1,000,000 reported screening tests of asymptomatic staff, patients, residents, and visitors in hospitals and long-term care (LTC) facilities in the State of Bavaria over a period of seven months. Data were used from the online database BayCoRei (Bavarian Corona Screening Tests), established in July 2020. Descriptive analyses were performed, describing the temporal pattern of persons that tested positive for SARS-CoV-2 by real-time polymerase chain reaction (RT-PCR) or antigen tests, stratified by facility. Until 15 March 2021, this database had collected 1,038,146 test results of asymptomatic subjects in healthcare facilities (382,240 by RT-PCR, and 655,906 by antigen tests). Of the RT-PCR tests, 2.2% (n = 8380) were positive: 3.0% in LTC facilities, 2.2% in hospitals, and 1.2% in rehabilitation institutions. Of the antigen tests, 0.4% (n = 2327) were positive: 0.5% in LTC facilities, and 0.3% in both hospitals and rehabilitation institutions, respectively. In LTC facilities and hospitals, infection surveillance using RT-PCR tests, or the less expensive but less sensitive, faster antigen tests, could facilitate the long-term management of the healthcare workforce, patients, and residents.

Xanthohumol, a Prenylated Chalcone Derived from Hops, Inhibits Growth and Metastasis of Melanoma Cells.

Melanoma is one of the most aggressive and lethal cancers worldwide. Despite recent progress in melanoma therapy, the prognosis for metastasized melanoma continues to be poor. Xanthohumol (XN), a prenylated chalcone derived from hop cones, is known to possess a broad spectrum of chemopreventive and anticancer activities. However, few studies have analyzed functional XN effects on melanoma cells and there have been no previous in vivo studies of its effects on metastasis. The aim of this study was to investigate the impact of XN on the tumorigenic and liver metastatic activity of melanoma cells. XN exhibited dose-dependent cytotoxic effects on human melanoma cell lines (Mel Ju; Mel Im) in vitro. Functional analysis in the subtoxic dose-range revealed that XN dose-dependently inhibited proliferation, colony formation, and migratory activity of melanoma cells. Subtoxic XN doses also induced markers of endoplasmic reticulum stress but inhibited the phosphorylation of the protumorigenic c-Jun N-terminal kinases (JNK). Furthermore, XN effects on hepatic metastasis were analyzed in a syngeneic murine model (splenic injection of murine B16 melanoma cells in C57/BL6 mice). Here, XN significantly reduced the formation of hepatic metastasis. Metastases formed in the liver of XN-treated mice revealed significantly larger areas of central necrosis and lower Ki67 expression scores compared to that of control mice. In conclusion, XN inhibits tumorigenicity of melanoma cells in vitro and significantly reduced hepatic metastasis of melanoma cells in mice. These data, in conjunction with an excellent safety profile that has been confirmed in previous studies, indicate XN as a promising novel agent for the treatment of hepatic (melanoma) metastasis.

Intraoperative Characterization of Pancreatic Tumors Using Contrast-Enhanced Ultrasound and Shear Wave Elastography for Optimization of Surgical Strategies.

OBJECTIVES: To evaluate intraoperative contrast-enhanced ultrasound (IoCEUS) and intraoperative shear wave elastography (IoSWE) for characterization of focal pancreatic lesions (FPLs) in correlation with postoperative histologic results. Thereby, the impact of intraoperative ultrasound (US) on pancreas surgery was evaluated. METHODS: Intraoperative CEUS and SWE data from 54 patients, who underwent pancreas surgery between 2017 and 2019, were analyzed retrospectively. Ultrasound examinations were performed with multifrequency linear/T-shaped transducers (3-9 MHz) on a high-end US device (LOGIQ E9; GE Healthcare, Chicago, IL). To analyze FPL stiffness by SWE, regions of interest were placed to measure the shear wave speed (meters per second) and stiffness (kilopascals). After intravenous bolus injections of 2.4 to 10 mL of sulfur hexafluoride microbubbles, a dynamic analysis of FPL microvascularization from arterial to late phases was performed using IoCEUS considering hypoenhancement/irregular vascularization of macrocystic/small solid FPL malignancy criteria. Ultrasound findings were correlated with postoperative histologic results. The impact of intraoperative US on surgery was documented in each case. RESULTS: Of 54 FPLs, IoCEUS could correctly characterize 39 of 39 malignant and 6 of 15 benign FPLs; IoSWE 29 of 39 as malignant and 7 of 15 as benign. Intraoperative CEUS's sensitivity was 100%; specificity, 40%; accuracy, 83.3%; positive predictive value, 81.3%; and negative predictive value, 100% (P < .05). Applying cutoff values of 3 m/s and 28.7 kPa, SWE's sensitivity was 74.4%; specificity, 46.7%; accuracy, 66.7%; positive predictive value; 78.4%; and negative predictive value, 41.2% for cancer detection (P < .05). The combined use of both techniques showed an accuracy rate of 76%, sensitivity of 74.4%, and specificity of 33.3%. In 29.6%, US results had an immediate impact on surgery. CONCLUSIONS: Intraoperative SWE and CEUS are highly valuable techniques for intraoperative characterization of FPLs. Although IoCEUS proved to be superior to IoSWE, the combined use can be helpful in particular cases.

Gene Expression Signatures of a Preclinical Mouse Model during Colorectal Cancer Progression under Low-Dose Metronomic Chemotherapy.

Understanding the molecular signatures of colorectal cancer progression under chemotherapeutic treatment will be crucial for the success of future therapy improvements. Here, we used a xenograft-based mouse model to investigate, how whole transcriptome signatures change during metastatic colorectal cancer progression and how such signatures are affected by LDM chemotherapy using RNA sequencing. We characterized mRNAs as well as non-coding RNAs such as microRNAs, long non-coding RNAs and circular RNAs in colorectal-cancer bearing mice with or without LDM chemotherapy. Furthermore, we found that circZNF609 functions as oncogene, since over-expression studies lead to an increased tumor growth while specific knock down results in smaller tumors. Our data represent novel insights into the relevance of non-coding and circRNAs in colorectal cancer and provide a comprehensive resource of gene expression changes in primary tumors and metastases. In addition, we present candidate genes that could be important modulators for successful LDM chemotherapy.

Safe Long-Term Outcome After Kidney Donation in Older Donors: A Single-Center Experience.

BACKGROUND Declining numbers of deceased donors and prolonged waiting time emphasize the importance of living kidney donation. Furthermore, because of the changing age structures with increasingly older recipients, the question of acceptance of older donors is becoming more relevant. However, sufficient long-term outcome data, especially for older donors - including histopathological analysis - are lacking. The aim of this study was to analyze the Regensburg Living Donor Cohort with regard to age <65 and ≥65 years, with a 10-year follow-up to identify attributable risk factors. MATERIAL AND METHODS All donors were analyzed for renal, cardiovascular, and pre-existing conditions at baseline and at follow-up. They were studied for predefined renal and additional end-points, eg cardiovascular ones and various stratifications such as estimated glomerular filtration rate (eGFR). Additionally, as a unique feature in such an analysis, a histopathological workup of pre-existing chronic lesions of the donated kidneys was added. RESULTS On average, donors in the group <65 years were 50 years old at the time of donation compared with 68 years in the older group. Creatinine at baseline was 0.8 mg/dl in both groups, corresponding to an eGFR of 96.8±12.8 ml/min (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) and 83.7±10.3 ml/min (CKD-EPI). In the follow-up, donors ≥65 years showed a statistically significantly worse eGFR and a greater eGFR decline, being accompanied by more pronounced chronic histopathological lesions, eg glomerulopathy, than the control group. However, this was largely constant over the entire observation period and no donor developed an end-stage renal disease or an eGFR below 30 ml/min. CONCLUSIONS To summarize, living kidney donation after an intensive screening is safe even for older donors; however, a precise aftercare to ensure balanced risk profile for living donors is mandatory.

Comprehensive analysis of translation from overexpressed circular RNAs reveals pervasive translation from linear transcripts.

Circular RNAs (circRNAs) encompass a widespread and conserved class of RNAs, which are generated by back-splicing of downstream 5' to upstream 3' splice sites. CircRNAs are tissue-specific and have been implicated in diseases including cancer. They can function as sponges for microRNAs (miRNAs) or RNA binding proteins (RBPs), for example. Moreover, some contain open reading frames (ORFs) and might be translated. The functional relevance of such peptides, however, remains largely elusive. Here, we report that the ORF of circZNF609 is efficiently translated when expressed from a circZNF609 overexpression construct. However, endogenous proteins could not be detected. Moreover, initiation of circZNF609 translation is independent of m6A-generating enzyme METTL3 or RNA sequence elements such as internal ribosome entry sites (IRESs). Surprisingly, a comprehensive mutational analysis revealed that deletion constructs, which are deficient in producing circZNF609, still generate the observed protein products. This suggests that the apparent circZNF609 translation originates from trans-splicing by-products of the overexpression plasmids and underline that circRNA overexpression constructs need to be evaluated carefully, particularly when functional studies are performed.

Antiretroviral Treatment Simplification With 2-Drug Regimens: Impact of Transmitted Drug Resistance Mutations.

The frequency of clinically relevant transmitted drug resistance mutations (DRMs) against drugs used for 2-drug regimens was 15.6%, but only 2% were not eligible for 1 or more 2-drug regimens. More than 50% of patients harboring any clinically relevant DRMs were found to be part of genetic transmission clusters.

LEF1 supports metastatic brain colonization by regulating glutathione metabolism and increasing ROS resistance in breast cancer.

More than half of all brain metastases show infiltrating rather than displacing growth at the macro-metastasis/organ parenchyma interface (MMPI), a finding associated with shorter survival. The lymphoid enhancer-binding factor-1 (LEF1) is an epithelial-mesenchymal transition (EMT) transcription factor that is commonly overexpressed in brain-colonizing cancer cells. Here, we overexpressed LEF1 in an in vivo breast cancer brain colonization model. It shortened survival, albeit without engaging EMT at the MMPI. By differential proteome analysis, we identified a novel function of LEF1 as a regulator of the glutathione (GSH) system, the principal cellular redox buffer. LEF1 overexpression also conferred resistance against therapeutic GSH depletion during brain colonization and improved management of intracellular ROS. We conclude that besides EMT, LEF1 facilitates metastasis by improving the antioxidative capacity of epithelial breast cancer cells, in particular during colonization of the brain parenchyma.

Intraoperative Shear Wave Elastography vs. Contrast-Enhanced Ultrasound for the Characterization and Differentiation of Focal Liver Lesions to Optimize Liver Tumor Surgery.

PURPOSE: Assessment of intraoperative quantitative shear wave elastography (SWE) and contrast-enhanced ultrasound (CEUS) for the characterization of focal liver lesions (FLLs) during liver surgery using postoperative histopathological results as the gold standard. MATERIALS AND METHODS: US data of 79 consecutive patients with 98 FLLs who underwent liver surgery between 08/2015 - 06/2017 were prospectively acquired and retrospectively analyzed. Multifrequency linear/T-shaped probes (6 - 9 MHz) were used to store cine loops of at least 5 s and images of B-mode, SWE and CEUS. The first CEUS loop was continuously documented over 1 min. in each case. Quantitative SWE analysis of FLLs was performed by placing 5 regions of interest to measure shear wave speed (m/s) and stiffness (kPa). CEUS was evaluated during the arterial, portal venous and late phase after i. v. bolus injections of 2.4 - 10 ml sulfur hexafluoride microbubbles. Postoperative histopathology after tumor resection or intraoperative biopsy was obtained to confirm findings of SWE and CEUS. RESULTS: Of 98 FLLs in 79 patients (mean age: 58 years sd ±â€Š12y) 88 were malignant and 10 were benign ranging from 0.69 to 15.2 cm in size (mean: 2.8 cm, sd ±â€Š2.25 cm). SWE characterized 73/88 FLLs correctly as malignant and 7/10 as benign using a cut-off value of 2.5 m/s/21.3 kPa (p < 0.0005). The sensitivity was 83 %, specificity 70 %, accuracy 82 %. CEUS could correctly identify 86/88 malignant and 8/10 benign FLLs. The sensitivity was 98 %, specificity 80 %, accuracy 96 %. SWE could correctly identify 2 malignant FLLs which CEUS falsely characterized as benign. CONCLUSION: Intraoperative CEUS and SWE are excellent tools for the highly accurate visualization, characterization and malignancy assessment of hepatic tumors during liver surgery.

Clinical Efficacy of a Novel Therapeutic Principle, Anakoinosis.

Classic tumor therapy, consisting of cytotoxic agents and/or targeted therapy, has not overcome therapeutic limitations like poor risk genetic parameters, genetic heterogeneity at different metastatic sites or the problem of undruggable targets. Here we summarize data and trials principally following a completely different treatment concept tackling systems biologic processes: the principle of communicative reprogramming of tumor tissues, i.e., anakoinosis (ancient greek for communication), aims at establishing novel communicative behavior of tumor tissue, the hosting organ and organism via re-modeling gene expression, thus recovering differentiation, and apoptosis competence leading to cancer control - in contrast to an immediate, "poisoning" with maximal tolerable doses of targeted or cytotoxic therapies. Therefore, we introduce the term "Master modulators" for drugs or drug combinations promoting evolutionary processes or regulating homeostatic pathways. These "master modulators" comprise a broad diversity of drugs, characterized by the capacity for reprogramming tumor tissues, i.e., transcriptional modulators, metronomic low-dose chemotherapy, epigenetically modifying agents, protein binding pro-anakoinotic drugs, such as COX-2 inhibitors, IMiDs etc., or for example differentiation inducing therapies. Data on 97 anakoinosis inducing schedules indicate a favorable toxicity profile: The combined administration of master modulators, frequently (with poor or no monoactivity) may even induce continuous complete remission in refractory metastatic neoplasia, irrespectively of the tumor type. That means recessive components of the tumor, successively developing during tumor ontogenesis, are accessible by regulatory active drug combinations in a therapeutically meaningful way. Drug selection is now dependent on situative systems characteristics, to less extent histology dependent. To sum up, anakoinosis represents a new substantive therapy principle besides novel targeted therapies.

Inhibition of mTORC2/RICTOR Impairs Melanoma Hepatic Metastasis.

Mammalian target of rapamycin complex 2 (mTORC2) with its pivotal component rapamycin-insensitive companion of mTOR (RICTOR) is the major regulator of AKT phosphorylation and is increasingly implicated in tumor growth and progression. In cutaneous melanoma, an extremely aggressive and highly metastatic disease, RICTOR overexpression is involved in tumor development and invasiveness. Therefore, we investigated the impact of RICTOR inhibition in melanoma cells in vitro and in vivo with special emphasis on hepatic metastasis. Moreover, our study focused on the interaction of tumor cells and hepatic stellate cells (HSC) which play a crucial role in the hepatic microenvironment. In silico analysis revealed increased RICTOR expression in melanoma cells and tissues and indicated higher expression in advanced melanoma stages and metastases. In vitro, transient RICTOR knock-down via siRNA caused a significant reduction of tumor cell motility. Using a syngeneic murine splenic injection model, a significant decrease in liver metastasis burden was detected in vivo. Moreover, stimulation of melanoma cells with conditioned medium (CM) from activated HSC or hepatocyte growth factor (HGF) led to a significant induction of AKT phosphorylation and tumor cell motility. Blocking of RICTOR expression in cancer cells diminished constitutive and HGF-induced AKT phosphorylation as well as cell motility. Interestingly, RICTOR blockade also led to an abrogation of CM-induced effects on AKT phosphorylation and motility in melanoma cells. In conclusion, these results provide first evidence for a critical role of mTORC2/RICTOR in melanoma liver metastasis via cancer cell/HSC interactions.

Mechanical Bowel Preparation (MBP) Prior to Elective Colorectal Resections in Crohn's Disease Patients.

Background: Studies addressing the role of mechanical bowel preparation (MBP) in Crohn's disease (CD) patients are lacking. Methods: Consecutive elective colorectal resections for CD have been included in the present analysis. Exclusion criteria were small bowel resections not including colon, urgent surgeries, surgeries for cancer, and abdominoperineal resections for perianal disease. MBP was performed routinely between 1992 and 2004, omitted between 2005 and 2015, and reintroduced in 2016.Intraabdominal septic complications (IASC) were anastomotic leakage, intraabdominal abscess, intestinal fistula, and peritonitis. Results: Overall, 680 bowel resections for CD have been performed between 1992 and 2017. After exclusion of the abovementioned patients, 549 patients were included in the present analysis. The IASC rate was 12% in patients undergoing surgery after MPB as opposed to 24% when MBP was omitted (P < 0.001). By the multivariate analysis, preoperative MBP significantly reduced the risk of IASC (Hazard ratio 0.45; 95% CI, 0.23 - 0.86; P = 0.016). Preoperative weight loss (HR 2.0; 95% CI, 1.1 - 3.6; P = 0.024), penetrating disease (HR 2.6; 95% CI, 1.3 - 5.4; P = 0.01), and stapled as opposed to hand-sewn ileocolic anastomosis (HR 3.3; 95% CI, 1.4 - 7.7; P = 0.006) were associated with an increased risk of IASC. The positive impact of MBP was strongest on anastomotic complication rate in patients undergoing ileocolic resections for penetrating disease (11% vs 36%, P < 0.001). Conclusion: Preoperative MPB should be strongly considered before colorectal surgery in patients with CD, especially in patients undergoing ileocolic resections for penetrating disease.

Split liver transplantation: Current developments.

In 1988, Rudolf Pichlmayr pioneered split liver transplantation (SLT), enabling the transplantation of one donor liver into two recipients - one pediatric and one adult patient. In the same year, Henri Bismuth and colleagues performed the first full right/full left split procedure with two adult recipients. Both splitting techniques were rapidly adopted within the transplant community. However, a SLT is technically demanding, may cause increased perioperative complications, and may potentially transform an excellent deceased donor organ into two marginal quality grafts. Thus, crucial evaluation of donor organs suitable for splitting and careful screening of potential SLT recipients is warranted. Furthermore, the logistic background of the splitting procedure as well as the organ allocation policy must be adapted to further increase the number and the safety of SLT. Under defined circumstances, in selected patients and at experienced transplant centers, SLT outcomes can be similar to those obtained in full organ LT. Thus, SLT is an important tool to reduce the donor organ shortage and waitlist mortality, especially for pediatric patients and small adults. The present review gives an overview of technical aspects, current developments, and clinical outcomes of SLT.