Towards a Standardization of Learning Curve Assessment in Minimally Invasive Liver Surgery.

OBJECTIVE: The aim was to analyze the learning curves of minimal invasive liver surgery(MILS) and propose a standardized reporting. SUMMARY BACKGROUND DATA: MILS offers benefits compared to open resections. For a safe introduction along the learning curve, formal training is recommended. However, definitions of learning curves and methods to assess it lack standardization. METHODS: A systematic review of PubMed, Web of Science, and CENTRAL databases identified studies on learning curves in MILS. The primary outcome was the number needed to overcome the learning curve. Secondary outcomes included endpoints defining learning curves, and characterization of different learning phases(competency, proficiency and mastery). RESULTS: 60 articles with 12'241 patients and 102 learning curve analyses were included. The laparoscopic and robotic approach was evaluated in 71 and 18 analyses and both approaches combined in 13 analyses. Sixty-one analyses (60%) based the learning curve on statistical calculations. The most often used parameters to define learning curves were operative time (n=64), blood loss (n=54), conversion (n=42) and postoperative complications (n=38). Overall competency, proficiency and mastery were reached after 34 (IQR 19-56), 50 (IQR 24-74), 58 (IQR 24-100) procedures respectively. Intraoperative parameters improved earlier (operative time: competency to proficiency to mastery: -13%, 2%; blood loss: competency to proficiency to mastery: -33%, 0%; conversion rate (competency to proficiency to mastery; -21%, -29%), whereas postoperative complications improved later (competency to proficiency to mastery: -25%, -41%). CONCLUSIONS: This review summarizes the highest evidence on learning curves in MILS taking into account different definitions and confounding factors. A standardized three-phase reporting of learning phases (competency, proficiency, mastery) is proposed and should be followed.

Hepatic Artery Infusion Chemotherapy for Primary and Secondary Malignancies of the Liver: State of the Art and Current High-Level Evidence.

BACKGROUND: Hepatic artery infusion chemotherapy (HAI) has been proposed as a valuable adjunct for multimodal therapy of primary and secondary liver malignancies. This review provides an overview of the currently available evidence of HAI, taking into account tumor response and long-term oncologic outcome. SUMMARY: In colorectal liver metastases (CRLM), HAI in combination with systemic therapy leads to high response rates (85-90%) and conversion to resectablity in primary unresectable disease in up to 50%. HAI in combination with systemic therapy in CRLM in the adjuvant setting shows promising long-term outcomes with up to 50% 10-year survival in a large, non-randomized single-center cohort. For hepatocellular carcinoma patients, response rates as high as 20-40% have been reported for HAI and long-term outcomes compare well to other therapies. Similarly, survival for patients with unresectable intrahepatic cholangiocarcinoma 3 years after treatment with HAI is reported as high as 34%, which compares well to trials of systemic therapy where 3-year survival is usually below 5%. However, evidence is mainly limited by highly selected, heterogenous patient groups, and outdated chemotherapy regimens. The largest body of evidence stems from small, often non-randomized cohorts, predominantly from highly specialized single centers. KEY MESSAGE: In well-selected patients with primary and secondary liver malignancies, HAI might improve response rates and, possibly, long-term survival. Results of ongoing randomized trials will show whether a wider adoption of HAI is justified, particularly to increase rates of resectability in advanced malignant diseases confined to the liver.

The short- and long-term outcome after the surgical management of common bile duct stones in a tertiary referral hospital.

BACKGROUND: The removal of common bile duct stones by endoscopic retrograde cholangiopancreatography (ERCP) shows excellent results with low complication rates and is therefore considered a gold standard. However, in case of stones non-removable by ERCP, surgical extraction is needed. The surgical approach is still controversial and clinical guidelines are missing. This study aims to analyze the outcomes of patients treated with choledochotomy or hepaticojejunostomy for common bile duct stones. METHODS: All patients who underwent choledochotomy or hepaticojejunostomy for common bile duct stones at a tertiary referral hospital over 11 years were included. The analyzed data contains basic demographics, diagnostics, surgical parameters, length of hospitalization, and morbidity and mortality. RESULTS: Over the study period, 4375 patients underwent cholecystectomy, and 655 received an ERCP with stone extraction, with 48 of these patients receiving subsequent surgical treatment. ERCP was attempted in 23/30 (77%) of the choledochotomy patients pre/intraoperatively and 11/18 (56%) in hepaticojejunostomy patients. The 30-day major complication rate (Clavien-Dindo > II) was 1/30 (3%) in the choledochotomy group and 2/18 (11%) in the hepaticojejunostomy group. Complications after 30 days occurred in 3/30 (10%) patients and 2/18 (11%), respectively, and no mortality occurred. CONCLUSION: ERCP should still be considered the gold standard, although due to low short- and long-term morbidity rates, choledochotomy and hepaticojejunostomy represent effective surgical solutions for common bile duct stones.

Stimulatory MAIT cell antigens reach the circulation and are efficiently metabolised and presented by human liver cells.

OBJECTIVE: Mucosal-associated invariant T (MAIT) cells are the most abundant T cells in human liver. They respond to bacterial metabolites presented by major histocompatibility complex-like molecule MR1. MAIT cells exert regulatory and antimicrobial functions and are implicated in liver fibrogenesis. It is not well understood which liver cells function as antigen (Ag)-presenting cells for MAIT cells, and under which conditions stimulatory Ags reach the circulation. DESIGN: We used different types of primary human liver cells in Ag-presentation assays to blood-derived and liver-derived MAIT cells. We assessed MAIT cell stimulatory potential of serum from healthy subjects and patients with portal hypertension undergoing transjugular intrahepatic portosystemic shunt stent, and patients with inflammatory bowel disease (IBD). RESULTS: MAIT cells were dispersed throughout healthy human liver and all tested liver cell types stimulated MAIT cells, hepatocytes being most efficient. MAIT cell activation by liver cells occurred in response to bacterial lysate and pure Ag, and was prevented by non-activating MR1 ligands. Serum derived from peripheral and portal blood, and from patients with IBD stimulated MAIT cells in MR1-dependent manner. CONCLUSION: Our findings reveal previously unrecognised roles of liver cells in Ag metabolism and activation of MAIT cells, repression of which creates an opportunity to design antifibrotic therapies. The presence of MAIT cell stimulatory Ags in serum rationalises the observed activated MAIT cell phenotype in liver. Increased serum levels of gut-derived MAIT cell stimulatory ligands in patients with impaired intestinal barrier function indicate that intrahepatic Ag-presentation may represent an important step in the development of liver disease.

Incidence of Liver Resection Following the Introduction of Caseload Requirements for Liver Surgery in Switzerland.

BACKGROUND: Centralization of care is an established concept in complex visceral surgery. Switzerland introduced case load requirements (CR) in 2013 in five areas of cancer surgery. The current study investigates the effects of CR on indication and mortality in liver surgery. METHODS: This is a retrospective analysis of a complete national in-hospital data set including all admissions between January 1, 2005, and December 31, 2015. Primary outcome variables were the incidence proportion and the 60-day in-hospital mortality of liver resections. Incidence proportion was calculated as the overall yearly number of liver resections performed in relation to the population living in Switzerland before and after the introduction of CR. RESULTS: Our analysis shows an increase number of liver resections compared to the period before introduction of CR from 2005-2012 (4.67 resections/100,000) to 2013-2015 (5.32 resections/100,000) after CR introduction. Age-adjusted incidence proportion increased by 14% (OR 1.14 95 CI [1.07-1.22]). National in-hospital mortality remained stable before and after CR (4.1 vs 3.7%), but increased in high-volume institutions (3.6 vs 5.6%). The number of hospitals performing liver resections decreased after the introduction of CR from 86 to 43. Half of the resections were performed in institutions reaching the stipulated numbers (53% before vs 49% after introduction of CR). After implementation of CR, patients undergoing liver surgery had more comorbidities (88 vs 92%). CONCLUSION: The introduction of CR for liver surgery in Switzerland in 2013 was accompanied by an increase in operative volume with limited effects on centralization of care.

Persistent acute cholecystitis after cholecystostomy - increased mortality due to treatment approach?

BACKGROUND: Percutaneous cholecystostomy (PC) is a treatment option for acute cholecystitis (AC) in cases where cholecystectomy (CCY) is not feasible due to limited health conditions. The use of PC remains questionable. The aim was to retrospectively analyse the outcome of patients after PC. METHODS: All patients who underwent PC for AC at a tertiary referral hospital over 10 years were included. Descriptive statistics, analysed mortality with and without CCY after PC, and a multivariable logistic regression for potential confounder and a landmark sensitivity analysis for immortal time bias were used. RESULTS: Of 158 patients, 79 were treated with PC alone and 79 had PC with subsequent CCY. Without CCY, 48% (38 patients) died compared to 9% with CCY. In the multivariable analysis CCY was associated with 85% lower risk of mortality. The landmark analysis was compatible with the main analyses. Direct PC-complications occurred in 17% patients. Histologically, 22/75 (29%) specimens showed chronic cholecystitis, and 76% AC. CONCLUSION: Due to the high mortality rate of PC alone, performing up-front CCY is proposed. PC represents no definitive treatment for AC and should remain a short-term solution because of the persistent inflammatory focus. According to these findings, almost all specimens showed persistent inflammation.

Efficacy of intraoperative cholangiography versus preoperative magnetic resonance cholangiography in patients with intermediate risk for common bile duct stones.

BACKGROUND: This is the first randomized trial to evaluate the efficacy of intraoperative cholangiography (IOC) and magnetic resonance cholangiopancreatography (MRCP) in patients with suspected CBDS. METHODS: This unblinded, multicenter RCT was conducted at five swiss hospitals. Eligibility criteria were suspected CBDS. Patients were randomized to IOC and laparoscopic cholecystectomy (LC), followed by endoscopic retrograde cholangiopancreatography (ERCP) if needed, or MRCP followed by ERCP if needed, and LC. Primary outcome was length of stay (LOS), secondary outcomes were cost, stone detection, and complication rates. RESULTS: 122 Patients were randomised to the IOC Group (63) or the MRCP group (59). Median LOS for the IOC and the MRCP groups were 4 days IQR [3, 6] and [4, 6], with an estimated increase of LOS of 1.2 days in the MRCP group (p = 0.0799) in the linear model. Median cost in the IOC and MRCP groups were 10 473 Swiss Francs (CHF) and 10 801 CHF, respectively (p = 0.694). CBDS were found in 24 and 12 patients in the IOC and the MRCP groups, respectively (p = 0.0387). The complication rate did not differ between both groups. CONCLUSION: There is equipoise between both pathways. IOC has a significantly higher diagnostic yield than MRCP. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT02351492: Radiological Investigation of Bile Duct Obstruction (RIBO).

[Primary Liver Cancers - Hepatocellular Carcinoma and Cholangiocarcinoma]. / Lebereigene Tumoren ­ Hepatozelluläres und das Cholangiozelluläre Karzinom.

Primary Liver Cancers - Hepatocellular Carcinoma and Cholangiocarcinoma Abstract. Malignant liver tumors are often discovered as an incidental finding on sonography. Hepatocellular carcinoma (HCC) is the most common primary liver malignancy, followed by cholangiocellular carcinoma (CCC). The most employed diagnostic tests are MRI with gadolinium contrast medium or 3-phase CT abdomen. Biopsy of a hepatic nodule can be omitted if the radiologic and clinical presentation are typical. Patients with malignant liver tumors and / or unclear findings should present to a liver center. The most effective therapies for HCC and CCC include liver resection and liver transplantation. Only surgical oncologic R0 resection is curative. The therapy should be done by a multidisciplinary team. If primary surgery of the lesion is not possible, interventional or sytemic chemotherapy can also be helpful.

Does oral health-related quality of life of patients after solid organ transplantation indicate a response shift? Results of a systematic review.

BACKGROUND: The physical oral health and dental behaviour of patients after solid organ transplantation (SOT) has repeatedly been reported as insufficient. The objective of this systematic review was to detect whether the oral health-related quality of life (OHRQoL) of patients after SOT is reduced compared to that of healthy individuals. METHODS: A systematic literature search was performed by two independent individuals based on the PubMed, Web of Science and Scopus databases by using the following search terms: "transplantation" AND "oral health-related quality of life". The findings were checked to determine eligibility, whereby publication prior to 31 October 2020, examination of adult patients (age at least 18 years) with SOT, reporting of an OHRQoL outcome and full text in English language were the prerequisites for inclusion in the qualitative analysis. Quality appraisal of the included studies was performed using the Agency for Healthcare Research and Quality methodology checklist. RESULTS: Seven of 25 studies that examined patients after kidney (3), heart (2), liver (1) and lung transplantation (1) were included. Four studies included healthy controls, and five studies included a cohort of patients before transplantation for comparison. Clinical oral health examinations were heterogeneous between groups. The majority of studies (5/7) applied the short form of the "Oral Health Impact Profile" (OHIP 14) to assess OHRQoL. The OHIP 14 values ranged between 1.7 and 8.9 across studies, indicating an unaffected or just slightly reduced OHRQoL. Only one study found better OHRQoL in patients after SOT compared to a group before SOT, and one study confirmed worse OHRQoL of SOT recipients compared to a healthy control. Only two studies revealed an association between OHRQoL and oral health parameters. Furthermore, two studies each found a relationship between OHRQoL and general health-related quality of life or disease-related parameters. CONCLUSIONS: Patients after SOT show an unaffected or only slightly reduced OHRQoL, which was mainly independent of the insufficient oral status. This might indicate a shift in the perception threshold for oral diseases and conditions caused by the general health burden related to the SOT.

Intra-arterial EmboCept S® and DC Bead® effectively inhibit tumor growth of colorectal rat liver metastases.

BACKGROUND: Intra-arterial therapy with embolics is established for the treatment of malignancies of the liver. However, there are no studies comparing the different effects of various embolics used in clinical practice. Herein, we analyzed the effect of 3 different embolics on tumor growth in a rat model of colorectal liver metastases. METHODS: Eight days after subcapsular implantation of 5 × 105 colorectal cancer cells (CC531) in the left liver lobe of WAG/Rij rats were randomized into 4 groups (n = 8) and underwent intra-arterial hepatic therapy. Animals received either EmboCept S®, DC Bead® or Lipiodol® Ultra-Fluid. Animals of the control group received a comparable amount of saline. Tumor growth was measured on day 8 and 11 using a three-dimensional 40 MHz ultrasound device. On day 11 tumor and liver tissue were removed for histological and immunohistochemical analyses. RESULTS: On day 11 animals of the control group showed a tumor growth of ~ 60% compared to day 8. Application of Lipiodol Ultra-Fluid® did not significantly influence tumor growth (~ 40%). In contrast, treatment with EmboCept S® or DC Bead® completely inhibited tumor growth. Of interest, application of EmboCept S® did not only completely inhibit tumor growth but even decreased tumor size. Immunohistochemical analysis showed a significant increase of necrotic areas within the tumors after application of EmboCept S® and DC Bead® compared to Lipiodol® Ultra-Fluid. CONCLUSION: The present study demonstrates that an intra-arterial therapy with EmboCept S® and DC Bead®, but not Lipiodol® Ultra-Fluid, results in a complete inhibition of rat colorectal liver metastatic growth.

Association between the time after transplantation and different immunosuppressive medications with dental and periodontal treatment need in patients after solid organ transplantation.

OBJECTIVE: The aim of this study was to investigate the association of time after transplantation and different immunosuppressive medications with dental and periodontal treatment needs in patients after solid organ transplantation (SOT). METHODS: After lung, liver, or kidney transplantation, patients were included and divided into subgroups based on the time after SOT (0-1, 1-3, 3-6, 6-10, and >10 years) and immunosuppression (tacrolimus, cyclosporine, mycophenolate, glucocorticoids, sirolimus, and monotherapy vs combination). Dental treatment need was determined by the presence of carious lesions, while periodontal treatment need was diagnosed based on a Periodontal Screening index score of 3-4. The overall treatment need included both the dental and/or periodontal treatment needs. Statistical analysis was performed using the Kruskal-Wallis test and chi-squared test (P < .05). RESULTS: A total of 169 patients were included after SOT. A dental treatment need of 44%, a periodontal treatment need of 71%, and an overall treatment need of 84% were detected in the total cohort. Only patients with >10 years after SOT had a lower dental treatment need compared to the other groups (P = .02). All other comparisons of dental, periodontal, and overall treatment needs were comparable between subgroups depending on time since SOT. Furthermore, no statistically significant differences were found in terms of the dental, periodontal, or overall treatment needs following the administration of different immunosuppressive medications. CONCLUSION: The high treatment need of patients after SOT, irrespective of the time since transplantation, suggests insufficient dental and periodontal treatment before and maintenance after organ transplantation. Furthermore, immunosuppressive medication was not associated with the treatment need.

Oral health-related quality of life depending on dental and periodontal health in different patients before and after liver transplantation.

BACKGROUND: The aim of this study was to evaluate the oral health-related quality of life (OHRQoL) depending on dental and periodontal health of different patients before and after liver transplantation (pre- and postLTx) compared to a healthy control group (HC). METHODS: OHRQoL was rated using the German short form of Oral Health Impact Profile (OHIP G14). To estimate dental health, the decayed (D-T), missing (M-T), and filled (F-T) teeth index (DMF-T) was used. Periodontal health was classified as healthy/mild, moderate, or severe periodontitis. The following statistics are used: Mann-Whitney U test, Kruskal-Wallis test, chi-square test, and Fisher test (α = 5%). RESULTS: A total of 24 preLTx, 47 postLTx, and 75 HC patients were included. Significant differences in DMF-T, D-T, M-T, and F-T scores were detected between groups (p < 0.001). Prevalence of periodontitis was comparable between groups (p = 0.340). OHRQoL was reduced in pre- and postLTx (OHIP G14 preLTx 4.2 [1.5; 0-4.0], postLTx 4.1 [1; 0-5.0], HC 1.4 [0; 0-2.0]; p = 0.003), without associations to their oral status (p > 0.05). CONCLUSIONS: These preliminary findings show a reduced OHRQoL without associations to their oral status, which might indicate an influence of potential disease-related factors on OHRQoL. Further studies with larger groups are necessary to verify this observation. CLINICAL RELEVANCE: A special dental care of patients before and after LTx is needed, including a comprehensive assessment of the individual patient's OHRQoL.

Graft-derived cell-free DNA, a noninvasive early rejection and graft damage marker in liver transplantation: A prospective, observational, multicenter cohort study.

BACKGROUND: Graft-derived cell-free DNA (GcfDNA), which is released into the blood stream by necrotic and apoptotic cells, is a promising noninvasive organ integrity biomarker. In liver transplantation (LTx), neither conventional liver function tests (LTFs) nor immunosuppressive drug monitoring are very effective for rejection monitoring. We therefore hypothesized that the quantitative measurement of donor-derived cell-free DNA (cfDNA) would have independent value for the assessment of graft integrity, including damage from acute rejection. METHODS AND FINDINGS: Traditional LFTs were performed and plasma GcfDNA was monitored in 115 adults post-LTx at three German transplant centers as part of a prospective, observational, multicenter cohort trial. GcfDNA percentage (graft cfDNA/total cfDNA) was measured using droplet digital PCR (ddPCR), based on a limited number of predefined single nucleotide polymorphisms, enabling same-day turn-around. The same method was used to quantify blood microchimerism. GcfDNA was increased >50% on day 1 post-LTx, presumably from ischemia/reperfusion damage, but rapidly declined in patients without graft injury within 7 to 10 d to a median <10%, where it remained for the 1-y observation period. Of 115 patients, 107 provided samples that met preestablished criteria. In 31 samples taken from 17 patients during biopsy-proven acute rejection episodes, the percentage of GcfDNA was elevated substantially (median 29.6%, 95% CI 23.6%-41.0%) compared with that in 282 samples from 88 patients during stable periods (median 3.3%, 95% CI 2.9%-3.7%; p < 0.001). Only slightly higher values (median 5.9%, 95% CI 4.4%-10.3%) were found in 68 samples from 17 hepatitis C virus (HCV)-positive, rejection-free patients. LFTs had low overall correlations (r = 0.28-0.62) with GcfDNA and showed greater overlap between patient subgroups, especially between acute rejection and HCV+ patients. Multivariable logistic regression modeling demonstrated that GcfDNA provided additional LFT-independent information on graft integrity. Diagnostic sensitivity and specificity were 90.3% (95% CI 74.2%-98.0%) and 92.9% (95% CI 89.3%-95.6%), respectively, for GcfDNA at a threshold value of 10%. The area under the receiver operator characteristic curve was higher for GcfDNA (97.1%, 95% CI 93.4%-100%) than for same-day conventional LFTs (AST: 95.7%; ALT: 95.2%; γ-GT: 94.5%; bilirubin: 82.6%). An evaluation of microchimerism revealed that the maximum donor DNA in circulating white blood cells was only 0.068%. GcfDNA percentage can be influenced by major changes in host cfDNA (e.g., due to leukopenia or leukocytosis). One limitation of our study is that exact time-matched GcfDNA and LFT samples were not available for all patient visits. CONCLUSIONS: In this study, determination of GcfDNA in plasma by ddPCR allowed for earlier and more sensitive discrimination of acute rejection in LTx patients as compared with conventional LFTs. Potential blood microchimerism was quantitatively low and had no significant influence on GcfDNA value. Further research, which should ideally include protocol biopsies, will be needed to establish the practical value of GcfDNA measurements in the management of LTx patients.

Periodontal pathogenic bacteria and aMMP-8 findings depending on periodontal conditions of patients before and after liver transplantation.

BACKGROUND: The aim of this single-center cross-sectional study was to detect the prevalence of selected periodontal pathogenic bacteria and active matrix metalloproteinase-8 (aMMP-8) level in patients before (preLTx) and after liver transplantation (postLTx). METHODS: Periodontal pocket depth (PPD) and clinical attachment loss (CAL) were assessed. Subgingival biofilm samples were analyzed using polymerase chain reaction (PCR) to detect 11 common periodontal pathogens. Gingival crevicular fluid (GCF) samples were analyzed with enzyme-linked immunosorbent assay (ELISA) to determine aMMP-8 level and assigned to a scoring system: score 0: 0-8 ng/ml, score 1: 8-20 ng/ml, and score 2: >20 ng/ml. The following were used for the statistical analysis: t test, Mann-Whitney U test, Fishers test (α = 5 %). RESULTS: In total, 110 patients (preLTx: n = 35, postLTx: n = 75) could be included in the study. Periodontal findings were not significantly different between groups. In microbiological analysis, a significantly higher prevalence of Campylobacter rectus in preLTx group was detected (p = 0.03). Significantly more patients with score 0 in postLTx group (p = 0.024) and significantly more patients with score 1 in preLTx group were found (p = 0.004). Furthermore, aMMP-8 concentrations for patients with moderate periodontitis were significantly lower in postLTx group compared to preLTx group (p = 0.045). Additionally, in postLTx group, aMMP-8 concentration was significantly higher in patients with severe periodontitis compared to those with no/mild periodontitis (p = 0.016). CONCLUSION: LTx appears to affect aMMP-8 level, but not bacterial findings in patients after LTx. CLINICAL RELEVANCE: Determination of aMMP-8 level in patients after LTx with immunosuppressive medication might lead to wrong interpretation of the results.

Upregulation of hepatic melanocortin 4 receptor during rat liver regeneration.

BACKGROUND: Melanocortin 4 receptor (MC4R) is predominantly recognized to mediate energy metabolism and anti-inflammation through the central nervous system. However, the expression of MC4R has recently been identified in rat liver and was shown to be upregulated during acute phase response. This study aims to investigate potential roles of MC4R in liver regeneration. MATERIALS AND METHODS: Rat partial hepatectomy (PH) was performed, and MC4R expression was analyzed at different time points after resection. Sham-operated animals (SH) served as controls. In vitro primary hepatocytes (HCs) were isolated from normal rat liver and stimulated with α-melanocyte-stimulating hormone (MC4R agonist). Real-time polymerase chain reaction, Western blot, and immunofluorescence staining were applied to detect gene expression. RESULTS: Up to 8 h after PH, hepatic messenger RNA of proinflammatory cytokines interleukin 6 and tumor necrosis factor α reached peak values. Between 8 and 72 h after PH, rat liver regeneration was extremely active as assessed by the regeneration indices labeled by Ki-67. Immunofluorescence staining indicated that MC4R was mostly expressed in hepatocyte nuclear factor 4(+) cells (HCs) and upregulated during rat liver regeneration. Concurrently, the expression of hepatic MC4R protein was significantly higher in PH than in SH animals, and phosphorylated extracellular signal-regulated kinase 1/2 was remarkably increased in PH compared with SH animals (P < 0.05, respectively). In vitro experiments showed that the expression of proliferating cell nuclear antigen was significantly higher in HCs treated with α-melanocyte-stimulating hormone than in control HCs, which was correlated to the increase of phosphorylated extracellular signal-regulated kinase 1/2 and reduction of phosphorylated signal transducer and activator of transcription 3 (P < 0.05, respectively). CONCLUSIONS: MC4R is predominantly expressed in HCs and upregulated during rat liver regeneration. In vitro stimulation of HC MC4R is associated with a modulation of extracellular signal-regulated kinase and signal transducer and activator of transcription 3 pathways regulating liver regeneration.

Graft-Derived Cell-Free DNA as a Marker of Transplant Graft Injury.

Although short-term success after solid organ transplantation is good, long-term graft and recipient survival are both not satisfactory. Despite therapeutic drug monitoring (TDM) of immunosuppressive drugs (ISDs), both excessive and insufficient immunosuppression still do occur. There is a need for new biomarkers that, when combined with TDM, can be used to provide more effective and less toxic, personalized immunosuppression to improve long-term survival. Currently used methods are insufficient to rapidly, cost-effectively, and directly interrogate graft integrity after solid organ transplantation. However, because organ transplants are also genome transplants, measurement of graft-derived circulating cell-free DNA (GcfDNA) has shown promise as a way to improve both graft and recipient outcomes after solid organ transplantation through the early detection of severe graft injury, enabling an early intervention. A newly developed droplet digital polymerase chain reaction (ddPCR) method has advantages over expensive high-throughput sequencing methods to rapidly quantify GcfDNA percentages and absolute amounts. This procedure does not require donor DNA and therefore can be applied to any organ donor/recipient pair. The droplet digital polymerase chain reaction method allows for the early, sensitive, specific, and cost-effective direct assessment of graft integrity and can be used to define individual responses to ISDs including the minimal ISD exposures necessary to prevent rejection. This is especially important in patients undergoing ISD switches due to ISD toxicity, infections, or malignancies. Although prospective, multicenter clinical trials in liver, heart, and kidney transplantation have not been completed, early results suggest that GcfDNA can be combined with TDM to guide changes in immunosuppression to provide more effective, and less toxic treatment. Personalized immunosuppression will shift emphasis in transplantation from reaction to prevention and could improve outcome at lower health care costs.

Darbepoetin-α Promotes Cell Proliferation in Established Extrahepatic Colorectal Tumors after Major Hepatectomy.

BACKGROUND: The glycoprotein hormone erythropoietin and its analogue darbepoetin-α (DPO) have been shown to reduce the risk of acute liver failure after major hepatectomy. However, previous experimental studies have also shown that DPO significantly enhances neovascularization and tumor cell proliferation in established colorectal liver metastasis in hepatectomized and nonhepatectomized mice. The present study now analyzes whether DPO influences cell proliferation and migration as well as vascularization and growth of established colorectal metastasis at extrahepatic sites after major hepatectomy. METHODS: GFP-transfected CT26.WT colorectal cancer cells were implanted into dorsal skinfold chambers of syngeneic BALB/c mice. Five days after tumor cell implantation, the animals received a single dose of DPO (10 µg/kg body weight) or phosphate-buffered saline solution (PBS) intravenously. Additional animals received a 70% hepatectomy and DPO or PBS treatment. Tumor vascularization and growth as well as tumor cell migration, proliferation and apoptosis were studied repetitively over 14 days using intravital fluorescence microscopy, histology and immunohistochemistry. RESULTS: DPO did not influence tumor cell migration and apoptosis. In addition, DPO did not stimulate tumor cell infiltration or vascularization; however, significantly increased tumor cell proliferation was detected in hepatectomized animals. CONCLUSION: DPO increases cell proliferation in established extrahepatic colorectal metastases after major hepatectomy. Thus, DPO may not be recommended to stimulate regeneration of the remnant liver after major hepatectomy for colorectal liver metastasis.

Oral behavior, dental, periodontal and microbiological findings in patients undergoing hemodialysis and after kidney transplantation.

BACKGROUND: Aim of this single center cross-sectional study was to investigate oral behavior, dental, periodontal and microbiological findings in patients undergoing hemodialysis (HD) and after kidney transplantation (KT). METHODS: Patients undergoing HD for end-stage renal failure and after KT were investigated. Oral health behavior was recorded using a standardized questionnaire, e.g. dental behavior, tooth brushing, oral hygiene aids. Oral investigation included screening of oral mucosa, dental findings (DMF-T) and periodontal situation (Papilla bleeding index [PBI] periodontal probing depth [PPD] and clinical attachment loss [CAL]). Additionally, microbiological analysis of subgingival biofilm samples (PCR) was performed. STATISTICAL ANALYSIS: Student's t-test or Mann-Whitney-U-test, Fisher's exact test (α = 5 %). RESULTS: A total of 70 patients (HD: n = 35, KT: n = 35) with a mean age of 56.4 ± 11.1 (HD) and 55.8 ± 10.9 (KT) years were included. Lack in use of additional oral hygiene (dental floss, inter-dental brush) was found. KT group presented significantly more gingivial overgrowth (p = 0.01). DMF-T was 19.47 ± 5.84 (HD) and 17.61 ± 5.81 (KT; p = 0.21). Majority of patients had clinically moderate and severe periodontitis; showing a need for periodontal treatment of 57 % (HD) and 71 % (KT; p = 0.30). Significantly higher prevalence of Parvimonas micra and Capnocytophaga species in the HD group were found (p < 0.01). CONCLUSION: Periodontal treatment need and lack in oral behavior for both groups indicate the necessity of an improved early treatment and prevention of dental and periodontal disease, e.g. in form of special care programs. Regarding microbiological findings, no major differences between KT and HD patients were found.

Cilostazol improves hepatic blood perfusion, microcirculation, and liver regeneration after major hepatectomy in rats.

Major hepatectomy or small-for-size liver transplantation may result in postoperative liver failure. So far, no treatment is available to improve liver regeneration. Herein, we studied whether cilostazol, a selective phosphodiesterase III inhibitor, is capable of improving liver regeneration after major hepatectomy. Sprague-Dawley rats (n = 74) were treated with cilostazol (5 mg/kg daily) or a glucose solution and underwent either 70% liver resection or a sham operation. Before and after surgery, hepatic arterial and portal venous blood flow and hepatic microvascular perfusion were analyzed. Liver morphology, function, and regeneration were studied with histology, immunohistochemistry, western blotting, and bile excretion analysis. Cilostazol significantly increased hepatic blood flow and microcirculation before and after hepatectomy in comparison with sham-operated controls. This was associated with an elevation of hepatic vascular endothelial growth factor expression, an increase of hepatocellular proliferation, and an acceleration of liver regeneration. Furthermore, cilostazol protected the tissue of the remnant liver as indicated by an attenuation of hepatocellular disintegration. In conclusion, cilostazol increases hepatic blood perfusion, microcirculation, and liver regeneration after a major hepatectomy. Thus, cilostazol may represent a novel strategy to reduce the rate of liver failure after both extended hepatectomy and small-for-size liver transplantation.

Application of capillary immunoelectrophoresis revealed an age- and gender-dependent regulated expression of PrPC in liver.

The cellular prion protein (PrPC) is a glycoprotein, anchored to the plasma membrane and abundantly expressed in the central nervous system. The expression of PrPC in the peripheral tissues is low and only little information is available on its functions in the nonneuronal tissues. The antioxidant function of PrPC during the activation of hepatic stellate cells has already been reported. Therefore, the aim of the study was to expand our knowledge on the functions of PrPC by detailed characterization of its expressional profile in the liver. In a combined strategy by using capillary immunoelectrophoresis and standard techniques, we have shown a sexually dimorphic expression of PrPC in mice and human liver tissues. Further, we showed a significant age-dependent upregulation of PrPC expression in the liver of 14- and 9-month-old mice as compared to 3 months of age. Therefore, this study may provide new insights into the gender-specific role of PrPC in the liver, which may further be linked to its protective role against oxidative stress during aging. In addition, the current study also shows an application of immunoelectrophoresis with a low coefficient of variation to analyze the miniscule amount of PrPC in the mouse liver tissue.