Near-infrared Fluorescence Imaging for Detecting Pancreatic Liver Metastasis in an Orthotopic Athymic Mouse Model.

BACKGROUND/AIM: Evidence of metastatic disease precludes oncological resection of pancreatic cancer. Near-infrared (NIR) fluorescent labels, such as indocyanine green (ICG), assist in the intraoperative detection of occult and micrometastatic liver disease. The present study aimed to analyse the role of NIR fluorescence imaging using ICG for pancreatic liver disease as proof of concept in an orthotopic athymic mouse model. MATERIALS AND METHODS: Pancreatic ductal adenocarcinoma was induced by injecting L3.6pl human pancreatic tumour cells into the pancreatic tail of seven athymic mice. After four weeks of tumour growth, ICG was injected into the tail vein and NIR fluorescence imaging was performed at harvest to determine tumour-to-liver ratios (TLR) using Quest Spectrum® Fluorescence Imaging Platform. RESULTS: Pancreatic tumour growth and liver metastasis could be visually confirmed for all seven animals. None of the hepatic metastases showed any detectable ICG-uptake. ICG-staining failed to visualize the liver metastases or to increase fluorescence intensity of the rim around the hepatic lesions. CONCLUSION: ICG-staining fails to visualize liver metastases induced by L3.6pl pancreatic tumour cells in athymic nude mice by NIR fluorescence imaging. Further studies are necessary to delineate the underlying mechanism for insufficient ICG uptake in these pancreatic liver metastases and for the lack of a fluorescent rim around the liver lesions.

Is There an Association between Intra-Operative Detection of Pathogens in Subcutaneous Tissue and Surgical Site Infections? Results from a Prospective Study.

Background: Surgical site infections (SSIs) are a common complication in visceral surgery. Pathogens causing SSIs vary depending on the type of surgery. Patients and Methods: Within the scope of the Reduction of Postoperative Wound Infections by Antiseptica (RECIPE) trial we analyzed the pathogens cultured in intra-operative, subcutaneous swabs and in swabs from SSI in a single-center, prospective, randomized controlled study. Definition of SSI complied with the criteria of the U.S. Centers for Disease Control and Prevention (CDC). Results: The overall rate of SSI was 28.2% in 393 patients. Colorectal surgery was performed in 68.2% of elective laparotomies. Pathogens were more often detected in intra-operative subcutaneous swabs in patients who developed SSIs than in patients who did not develop SSIs (64.4% vs. 38.0%; p < 0.001). Enterococci were found in 29.1% of intra-operative swabs in patients with SSIs, followed by Escherichia coli in 15.5%. A higher rate of Enterococcus faecium was found in patients with anemia versus those without anemia (9.2% vs. 2.3%; p = 0.006) and in patients who smoked versus those who did not (11.8% vs. 3.6%; p = 0.008). A positive subcutaneous swab (odds ratio [OR], 2.51; 95% confidence interval [CI], 1.47-4.29; p = 0.001), pre-operative anemia (OR, 1.84; 95% CI, 1.08-3.13; p = 0.016), and renal insufficiency (OR, 2.15; 95% CI, 1.01-4.59; p = 0.048) were risk factors for SSIs. Conclusions: There is an association between the intra-operative detection of pathogens in subcutaneous tissue and the development of SSIs in visceral surgery. The most prevalent pathogens causing SSIs were enterococci and Escherichia coli. More efforts are justified to reduce subcutaneous colonization with pathogens, for example by using intra-operative wound irrigation with polyhexanide solution. This trial is registered at www.ClinicalTrials.gov (ID: NCT04055233).

Thymidine phosphorylase induction by ionizing radiation antagonizes 5-fluorouracil resistance in human ductal pancreatic adenocarcinoma.

Chemoresistance in pancreatic ductal adenocarcinoma (PDAC) frequently contributes to failure of systemic therapy. While the radiosensitizing properties of 5-fluorouracil (FU) are well known, it is unknown whether ionizing radiation (IR) sensitizes towards FU cytotoxicity. Here, we hypothesize that upregulation of thymidine phosphorylase (TP) by IR reverses FU chemoresistance in PDAC cells. The FU resistant variant of the human PDAC cell line AsPC-1 (FU-R) was used to determine the sensitizing effects of IR. Proliferation rates of FU sensitive parental (FU-S) and FU-R cells were determined by WST-1 assays after low (0.05 Gy) and intermediate dose (2.0 Gy) IR followed by FU treatment. TP protein expression in PDAC cells before and after IR was assessed by Western blot. To analyze the specificity of the FU sensitizing effect, TP was ablated by siRNA. FU-R cells showed a 2.7-fold increase of the half maximal inhibitory concentration, compared to FU-S parental cells. Further, FU-R cells showed a concomitant IR resistance towards both doses applied. When challenging both cell lines with FU after IR, FU-R cells had lower proliferation rates than FU-S cells, suggesting a reversal of chemoresistance by IR. This FU sensitizing effect was abolished when TP was blocked by anti-TP siRNA before IR. An increase of TP protein expression was seen after both IR doses. Our results suggest a TP dependent reversal of FU-chemoresistance in PDAC cells that is triggered by IR. Thus, induction of TP expression by low dose IR may be a therapeutic approach to potentially overcome FU chemoresistance in PDAC.

The impact of surgical site infection-a cost analysis.

PURPOSE: Surgical site infection (SSI) occurs in up to 25% of patients after elective laparotomy. We aimed to determine the effect of SSI on healthcare costs and patients' quality of life. METHODS: In this post hoc analysis based on the RECIPE trial, we studied a 30-day postoperative outcome of SSI in a single-center, prospective randomized controlled trial comparing subcutaneous wound irrigation with 0.04% polyhexanide to 0.9% saline after elective laparotomy. Total medical costs were analyzed accurately per patient with the tool of our corporate controlling team which is based on diagnosis-related groups in Germany. RESULTS: Between November 2015 and May 2018, 456 patients were recruited. The overall rate of SSI was 28.2%. Overall costs of inpatient treatment were higher in the group with SSI: median 16.685 €; 19.703 USD (IQR 21.638 €; 25.552 USD) vs. median 11.235 €; 13.276 USD (IQR 11.564 €; 13.656 USD); p < 0.001. There was a difference in surgery costs (median 6.664 €; 7.870 USD with SSI vs. median 5.040 €; 5.952 USD without SSI; p = 0.001) and costs on the surgical ward (median 8.404 €; 9.924 USD with SSI vs. median 4.690 €; 5.538 USD without SSI; p < 0.001). Patients with SSI were less satisfied with the cosmetic result (4.3% vs. 16.2%; p < 0.001). Overall costs for patients who were irrigated with saline were median 12.056 €; 14.237 USD vs. median 12.793 €; 15.107 USD in the polyhexanide group (p = 0.52). CONCLUSION: SSI after elective laparotomy increased hospital costs substantially. This is an additional reason why the prevention of SSI is important. Overall costs for intraoperative wound irrigation with saline were comparable with polyhexanide.

Survival rates and prognostic factors in right- and left-sided colon cancer stage I-IV: an unselected retrospective single-center trial.

PURPOSE: Colorectal cancer revealed over the last decades a remarkable shift with an increasing proportion of a right- compared to a left-sided tumor location. In the current study, we aimed to disclose clinicopathological differences between right- and left-sided colon cancer (rCC and lCC) with respect to mortality and outcome predictors. METHODS: In total, 417 patients with colon cancer stage I-IV were analyzed in the present retrospective single-center study. Survival rates were assessed using the Kaplan-Meier method and uni/multivariate analyses were performed with a Cox proportional hazards regression model. RESULTS: Our study showed no significant difference of the overall survival between rCC and lCC stage I-IV (p = 0.354). Multivariate analysis revealed in the rCC cohort the worst outcome for ASA (American Society of Anesthesiologists) score IV patients (hazard ratio [HR]: 16.0; CI 95%: 2.1-123.5), CEA (carcinoembryonic antigen) blood level > 100 µg/l (HR: 3.3; CI 95%: 1.2-9.0), increased lymph node ratio of 0.6-1.0 (HR: 5.3; CI 95%: 1.7-16.1), and grade 4 tumors (G4) (HR: 120.6; CI 95%: 6.7-2179.6) whereas in the lCC population, ASA score IV (HR: 8.9; CI 95%: 0.9-91.9), CEA blood level 20.1-100 µg/l (HR: 5.4; CI 95%: 2.4-12.4), conversion to laparotomy (HR: 14.1; CI 95%: 4.0-49.0), and severe surgical complications (Clavien-Dindo III-IV) (HR: 2.9; CI 95%: 1.5-5.5) were identified as predictors of a diminished overall survival. CONCLUSION: Laterality disclosed no significant effect on the overall prognosis of colon cancer patients. However, group differences and distinct survival predictors could be identified in rCC and lCC patients.

Raloxifene inhibits pancreatic adenocarcinoma growth by interfering with ERß and IL-6/gp130/STAT3 signaling.

PURPOSE: Currently, the exact role of estrogen receptor (ER) signaling in pancreatic cancer is unknown. Recently, we showed that expression of phosphorylated ERß correlates with a poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC). Here, we hypothesized that raloxifene, a FDA-approved selective ER modulator (SERM), may suppress PDAC tumor growth by interfering with ERß signaling. To test this hypothesis, we studied the impact of raloxifene on interleukin-6/glycoprotein-130/signal transducer and activator of transcription-3 (IL-6/gp130/STAT3) signaling. METHODS: Human PDAC cell lines were exposed to raloxifene after which growth inhibition was assessed using a BrdU assay. ER knockdown was performed using siRNAs specific for ERα and ERß. The effects of raloxifene on IL-6 expression and STAT3 phosphorylation in PDAC cells were assessed by ELISA and Western blotting, respectively. In addition, raloxifene was administered to an orthotopic PDAC tumor xenograft mouse model, after which tumor growth was monitored and immunohistochemistry was performed. RESULTS: Raloxifene inhibited the in vitro growth of PDAC cells, and this effect was reversed by siRNA-mediated knockdown of ERß, but not of ERα, indicating ER isotype-specific signaling. We also found that treatment with raloxifene inhibited the release of IL-6 and suppressed the phosphorylation of STAT3Y705 in PDAC cells. In vivo, we found that orthotopic PDAC tumor growth, lymph node and liver metastases as well as Ki-67 expression were reduced in mice treated with raloxifene. CONCLUSIONS: Inhibition of ERß and the IL-6/gp130/STAT3 signaling pathway by raloxifene leads to potent reduction of PDAC growth in vitro and in vivo. Our results suggest that ERß signaling and IL-6/gp130 interaction may serve as promising drug targets for pancreatic cancer and that raloxifene may serve as an attractive therapeutic option for PDAC patients expressing the ERß isotype.

Operative outcome of hernia repair with synthetic mesh in immunocompromised patients.

BACKGROUND: The safety of synthetic mesh in elective hernia repair in the setting of immunosuppression lacks national and international consensus. The aim of our analysis was to explore the effects of immunosuppression on the rates of wound complications. METHODS: Comparative analysis of immunocompetent and immunocompromised patients with elective mesh repair of inguinal, femoral, primary ventral, incisional or parastomal hernia between January 2001 and December 2013. Immunosuppression included glucocorticoids, biologicals, chemotherapy and chemoradiotherapy. Primary outcome parameter was mesh infection rate. Follow-up questionnaires were completed in written form or by telephone interview. RESULTS: Questionnaire response rate was 59.5% (n = 194) with a median follow-up of 33 (interquartile range: 28-41) months. There were no differences between immunocompromised (n = 40, 20.6%) and immunocompetent patients (n = 154, 79.4%) based on hernia and patient characteristics. Immunosuppression was not associated with the rates of mesh infection (P = 1.000), surgical site infection (SSI, P = 0.330) or re-operation for SSI (P = 0.365), but with higher rates (P = 0.007) and larger odds for hernia recurrence (odds ratio 3.264, 95% confidence interval 1.304-8.172; P = 0.012). Mesh infection also increased the odds for hernia recurrence (odds ratio 11.625; 95% confidence interval 1.754-77.057; P = 0.011). Only in the subset of ventral/incisional hernias, immunocompromised (n = 8, 40%) patients had higher recurrence rates than immunocompetent patients (n = 5, 11.6%; P = 0.017). Patients with SSI reported more frequently moderate to severe dysesthesia at the surgical site (P = 0.013) and would less frequently re-consent to surgery (P = 0.006). CONCLUSION: Immunosuppression does not increase the rate of wound infections after elective hernia repair with synthetic mesh. However, immunosuppression and mesh infection are risk factors for hernia recurrence.

Colorectal Cancer in the Adolescent and Young Adult Population.

Colorectal cancer in the young adult population is of increasing incidence and concern. Genetic predisposition and heritable syndromes contribute to this trend, but perhaps more concerning is the majority of new diagnoses that involve no traceable genetic risk factors. Prevention and early recognition, with a high suspicion in the symptomatic young adult, are critical in attenuating recent trends. Clinical management requires coordinated multidisciplinary care from diagnosis to surveillance in order to ensure appropriate management. This review provides a summary of key aspects related to colorectal cancer in adolescents and young adults, including epidemiology, biology, genetics, clinical management, and prevention.

Reduction of Postoperative Wound Infections by Antiseptica (RECIPE)?: A Randomized Controlled Trial.

OBJECTIVE: To evaluate whether intraoperative subcutaneous wound irrigation with 0.04% polyhexanide can reduce surgical site infection (SSI) in elective laparotomies compared to saline. BACKGROUND: SSI is a common complication after gastrointestinal surgery. To date, there is a lack of evidence whether subcutaneous wound irrigation is beneficial in terms of reduction of SSI. METHODS: The RECIPE trial was an investigator initiated single-center, single-blind prospective, randomized controlled trial with 2 parallel treatment groups, comparing wound irrigation with 0.9% saline to antiseptic 0.04% polyhexanide solution in elective laparotomies. Primary endpoint was the rate of SSI within 30 days postoperatively according to Centers for Disease Control and Prevention criteria. RESULTS: Between February 02, 2015, and May 23, 2018, 456 patients were randomly assigned to saline (n = 228) or polyhexanide (n = 228). Final cohort for analysis comprised 393 patients (202 in the saline and 191 in the polyhexanide group). Overall rate of SSI was 28.2%, n = 111. Simple analysis with cross tabulation revealed that significantly fewer SSIs occurred in the polyhexanide group: n = 70 (34.7%) versus n = 41 (21.5%); P = 0.004. In a multiple logistic regression model the factor wound irrigation with polyhexanide [odds ratio (OR) 0.44; 95% confidence interval (CI) 0.27-0.72; P = 0.001) was associated with risk reduction of SSI. Preoperative anemia (OR 2.08; 95% CI 1.27-3.40; P = 0.004) and more than 5 prior abdominal operations compared to none (OR 8.51; 95% CI 2.57-28.21; P < 0.001) were associated with SSI. CONCLUSIONS: Intraoperative subcutaneous wound irrigation with antiseptic 0.04% polyhexanide solution is effective in reducing SSI after elective laparotomies.

Antiproliferative and apoptotic effects of telmisartan in human colon cancer cells.

Telmisartan is an angiotensin I (AT1) receptor blocker used in the treatment of essential hypertension, with partial peroxisome proliferator-activated receptor γ (PPARγ) agonism. In prior studies, PPARγ activation led to apoptosis and cell cycle inhibition in various cancer cells. The aim of the present study was to investigate the potential antiproliferative and apoptotic effects of telmisartan by partially activating PPARγ. HT-29, SW-480 and SW-620 cells were incubated with telmisartan (0.2-5 µM) or the full agonist, pioglitazone (0.2-5.0 µM). The antiproliferative and apoptotic effects of telmisartan in the human colon cancer cells were significant at therapeutic serum concentrations, and telmisartan exhibited a potency at least equivalent to the full PPARγ agonist, pioglitazone. The antiproliferative and apoptotic effects of pioglitazone in the human colon cancer cells were not completely deregulated by PPARγ blockade with GW9662. In the telmisartan-treated cells, PPARγ blockade resulted in an increased antiproliferative and apoptotic effect. These effects are not entirely explained by PPARγ activation, however, possible hypotheses that require further experimental investigation are as follows: i) Ligand-independent PPARγ activation through the activation-function 1 domain; ii) a PPARγ-independent mechanism; or iii) independent antiproliferative and apoptotic effects through GW9662.

Regulation of peroxisome proliferator-activated receptor gamma activity by losartan metabolites.

Two active metabolites of the angiotensin type 1 (AT1) receptor blocker losartan have been described previously, EXP3174 and EXP3179. Whereas EXP3174 is the main antihypertensive AT1 receptor-blocking metabolite, the role of EXP3179 is widely unknown. Recently, a subgroup of AT1 receptor blockers has been identified as ligands for the peroxisome proliferator-activated receptor gamma (PPAR-gamma). Here we characterize the PPAR-gamma-activating properties of the 2 active losartan metabolites. PPAR-gamma activity was measured with a chimeric Gal4-DNA-binding domain-hPPARgamma-ligand-binding domain (LBD) fusion protein on a Gal4-dependent luciferase reporter system. EXP3179 prominently induced the activation of the PPAR-gamma-LBD reaching a maximum at 100 micromol/L with a 7.1+/-1-fold induction (P<0.05 versus vehicle-treated cells). Maximum PPAR-gamma-LBD activation by EXP3179 reached 51% of the maximum response induced by the full PPAR-gamma agonist pioglitazone, identifying EXP3179 as a partial PPAR-gamma agonist. EXP3174 did not induce PPAR-gamma-LBD activation. EC50 values were calculated for PPAR-gamma-LBD activity (pioglitazone EC50: 0.88 micromol/L; EXP3179 EC50: 17.1 micromol/L; losartan EC50: >50 micromol/L). Consistent with the activation of PPAR-gamma, EXP3179 potently induced 3T3-L1 adipocyte differentiation, a typical PPAR-gamma-dependent cell function, and markedly stimulated PPAR-gamma target gene expression. EXP3174 failed to regulate differentiation or PPAR-gamma target gene expression. The present study characterizes the active losartan metabolite EXP3179 as a partial PPAR-gamma agonist. PPAR-gamma activation by EXP3179 may help us to understand the beneficial metabolic effects of losartan observed in clinical trials.