Beyond Total Mesorectal Excision (TME)-Results of MRI-Guided Multivisceral Resections in T4 Rectal Carcinoma and Local Recurrence

Rectal cancer invading adjacent organs (T4) and locally recurrent rectal cancer (LRRC) pose a special challenge for surgical resection. We investigate the diagnostic performance of MRI and the results that can be achieved with MRI-guided surgery. All consecutive patients who underwent MRI-based multivisceral resection for T4 rectal adenocarcinoma or LRRC between 2005 and 2019 were included. Pelvic MRI findings were reviewed according to a seven-compartment staging system and correlated with histopathology. Outcomes were investigated by comparing T4 tumors and LRRC with respect to cause-specific survival in uni- and multivariate analysis. We identified 48 patients with T4 tumors and 28 patients with LRRC. Overall, 529 compartments were assessed with an accuracy of 81.7%, a sensitivity of 88.6%, and a specificity of 79.2%. Understaging was as low as 3.0%, whereas overstaging was 15.3%. The median number of resected compartments was 3 (interquartile range 3-4) for T4 tumors and 4 (interquartile range 3-5) for LRRC (p = 0.017). In 93.8% of patients with T4 tumors, a histopathologically complete (R0(local)-) resection could be achieved compared to 57.1% in LRRC (p < 0.001). Five-year overall survival for patients with T4 tumors was 53.3% vs. 32.1% for LRRC (p = 0.085). R0-resection and M0-category emerged as independent prognostic factors, whereas the number of resected compartments was not associated with prognosis in multivariate analysis. MRI predicts compartment involvement with high accuracy and especially avoids understaging. Surgery based on MRI yields excellent loco-regional results for T4 tumors and good results for LRRC. The number of resected compartments is not independently associated with prognosis, but R0-resection remains the crucial surgical factor.

Does practice make perfect? Laparoscopic training mainly improves motion efficiency: a prospective trial

Training improves skills in minimally invasive surgery. This study aimed to investigate the learning curves of complex motion parameters for both hands during a standardized training course using a novel measurement tool. An additional focus was placed on the parameters representing surgical safety and precision. Fifty-six laparoscopic novices participated in a training course on the basic skills of minimally invasive surgery based on a modified Fundamentals of Laparoscopic Surgery (FLS) curriculum. Before, twice during, and once after the practical lessons, all participants had to perform four laparoscopic tasks (peg transfer, precision cut, balloon resection, and laparoscopic suture and knot), which were recorded and analyzed using an instrument motion analysis system. Participants significantly improved the time per task for all four tasks (all p < 0.001). The individual instrument path length decreased significantly for the dominant and non-dominant hands in all four tasks. Similarly, both hands became significantly faster in all tasks, with the exception of the non-dominant hand in the precision cut task. In terms of relative idle time, only in the peg transfer task did both hands improve significantly, while in the precision cut task, only the dominant hand performed better. In contrast, the motion volume of both hands combined was reduced in only one task (precision cut, p = 0.01), whereas no significant improvement in the relative time of instruments being out of view was observed. FLS-based skills training increases motion efficiency primarily by increasing speed and reducing idle time and path length. Parameters relevant for surgical safety and precision (motion volume and relative time of instruments being out of view) are minimally affected by short-term training. Consequently, surgical training should also focus on safety and precision-related parameters, and assessment of these parameters should be incorporated into basic skill training accordingly.

Cognitive and motor skill competence are different: Results from a prospective randomized trial using virtual reality simulator and educational video in laparoscopic cholecystectomy

BACKGROUND AND PURPOSE

Cognitive transfer represents an important issue in surgical education. It is essential for the acquisition of competence, such as decision making and error avoidance. This randomized study aims to compare the effectivity of cognitive transfer by observing the surgery versus using modern virtual reality simulators for learning a laparoscopic cholecystectomy.

METHOD

This was a prospective, randomized, single centre study. 40 medical students from a university hospital, a tertiary care teaching institution, were enrolled. After a short introduction of laparoscopic cholecystectomy, they were randomized into two groups (video group and simulator group). In the video group, participants watched the step-by-step educational video twice. In the simulator group, participants underwent training using the virtual reality simulator, including tutorial procedural tasks of laparoscopic cholecystectomy as well as a complete cholecystectomy on the simulator. After the training, cognitive competence including decision making and error awareness was assessed using a questionnaire.

RESULTS

In the most critical step of laparoscopic cholecystectomy, "Dissection in Calot's triangle", as well as in the aspect of planning next step, the video group was superior significantly (P = 0.038 and P = 0.04). No significant differences concerning the recognition of critical anatomical structures, choosing the necessary instruments as well as error awareness were found.

CONCLUSIONS

Learning by watching a high-quality educational video is more effective in acquiring the cognitive competence to combine learned single tasks. Traditional learning means as watching educational videos and modern, sophisticated VRS should be deployed complementarily to establish cognitive and motor competencies separately.

Decision Conflicts in Clinical Care during COVID-19: A Multi-Perspective Inquiry

Background: The early COVID-19-pandemic was characterized by changes in decision making, decision-relevant value systems and the related perception of decisional uncertainties and conflicts resulting in decisional burden and stress. The vulnerability of clinical care professionals to these decisional dilemmas has not been characterized yet. Methods: A cross-sectional questionnaire study (540 patients, 322 physicians and 369 nurses in 11 institutions throughout Germany) was carried out. The inclusion criterion was active involvement in clinical treatment or decision making in oncology or psychiatry during the first year of COVID-19. The questionnaires covered five decision dimensions (conflicts and uncertainty, resources, risk perception, perception of consequences for clinical processes, and the perception of consequences for patients). Data analysis was performed using ANOVA, Pearson rank correlations, and the Chi²-test, and for inferential analysis, nominal logistic regression and tree classification were conducted. Results: Professionals reported changes in clinical management (27.5%) and a higher workload (29.2%), resulting in decisional uncertainty (19.2%) and decisional conflicts (22.7%), with significant differences between professional groups (p < 0.005), including anxiety, depression, loneliness and stress in professional subgroups (p < 0.001). Nominal regression analysis targeting “Decisional Uncertainty” provided a highly significant prediction model (LQ p < 0.001) containing eight variables, and the analysis for “Decisional Conflicts” included six items. The classification rates were 64.4% and 92.7%, respectively. Tree analysis confirmed three levels of determinants. Conclusions: Decisional uncertainty and conflicts during the COVID-19 pandemic were independent of the actual pandemic load. Vulnerable professional groups for the perception of a high number of decisional dilemmas were characterized by individual perception and the psychological framework. Coping and management strategies should target vulnerability, enable the handling of the individual perception of decisional dilemmas and ensure information availability and specific support for younger professionals.

Differences in Stakeholders' Perception of the Impact of COVID-19 on Clinical Care and Decision-Making

Background: Pandemics are related to changes in clinical management. Factors that are associated with individual perceptions of related risks and decision-making processes focused on prevention and vaccination, but perceptions of other healthcare consequences are less investigated. Different perceptions of patients, nurses, and physicians on consequences regarding clinical management, decisional criteria, and burden were compared. Study Design: Cross-sectional OnCoVID questionnaire studies. Methods: Data that involved 1231 patients, physicians, and nurses from 11 German institutions that were actively involved in clinical treatment or decision-making in oncology or psychiatry were collected. Multivariate statistical approaches were used to analyze the stakeholder comparisons. Results: A total of 29.2% of professionals reported extensive changes in workload. Professionals in psychiatry returned severe impact of pandemic on all major aspects of their clinical care, but less changes were reported in oncology (p < 0.001). Both patient groups reported much lower recognition of treatment modifications and consequences for their own care. Decisional and pandemic burden was intensively attributed from professionals towards patients, but less in the opposite direction. Conclusions: All of the groups share concerns about the impact of the COVID-19 pandemic on healthcare management and clinical processes, but to very different extent. The perception of changes is dissociated in projection towards other stakeholders. Specific awareness should avoid the dissociated impact perception between patients and professionals potentially resulting in impaired shared decision-making.

Effect of Genre and amplitude of music during laparoscopic surgery

PURPOSE

Music is often played in operating theaters. In the literature, the effects of music on surgeons are controversial. We aimed to investigate the effect of different music genres and amplitudes on laparoscopic performance.

METHODS

Novice surgeons underwent a proficiency-based laparoscopic training curriculum. Participants were required to perform these tasks under three conditions: no music, with music in medium volume (45-50 dB) and in high volume (65-70 dB). Soft rock by the Beatles and hard rock by AC/DC were played. Task performance was evaluated by analyzing speed and accuracy.

RESULTS

With soft rock in medium volume, participants were faster in peg transfer (60.3 vs. 56.7 s, P = 0.012) and more accurate in suture with intracorporeal knot (79.2 vs. 54.0, P = 0.011) compared to without music. The total score was improved (383.4 vs. 337.9, P = 0.0076) by enhancing accuracy (79.5 vs. 54.0, P = 0.011). This positive effect was lost if the soft rock was played in high volume. With hard rock in medium volume, participants were faster performing precision cutting (139.4 vs. 235.8, P = 0.0009) compared to without music. Both balloon preparation and precision cutting were performed more rapidly (227.3 vs. 181.4, P = 0.003, 139.4 vs. 114.0, P < 0.0001) and the accuracy was maintained. Hard rock in high volume also resulted in increased speed (366.7 vs. 295.5, P < 0.0001) compared to without music. Thereby, the total scores of participants were enhanced (516.5 vs. 437.1, P = 0.002).

CONCLUSION

Our data reveal that the effect of music on laparoscopic performance might depend on the combination of music genre and amplitude. A generally well-accepted music genre in the right volume could improve the performance of novice surgeons during laparoscopic surgeries.

TRIAL REGISTRATION

DRKS00026759, register date: 18.10.2021 (retrospectively registered).

[The suffering surgeon-How do German surgeons protect themselves? : Survey of the German Society of General and Visceral Surgery on the extent of occupational safety measures and health burden among German surgeons]

BACKGROUND

There are few data on how surgeons implement occupational safety measures to protect their own health and how they assess their subjective health burden.

OBJECTIVE

In times of a shortage of surgeons it makes sense to examine these relationships in order to evaluate future-oriented adjustments to increase the attractiveness of the profession of "surgeon".

MATERIAL AND METHODS

An online questionnaire was sent to the registered members of the German Society for General and Visceral Surgery (DGAV) in October 2016. The members were asked about the application of occupational safety measures, individual living conditions, working conditions and the subjective health burden depending on the level of training and type of hospital (basic, standard, maximum care).

RESULTS

The response rate was 21% (1065/5011). Occupational safety measures were not strictly implemented: routine use of dosimeters, thyroid radiation protection, smoke extraction and protective goggles only took place in 40% (427/1065), 39% (411/1065), 10% (104/1065) and 5% (55/1065), respectively. The majority of surgeons (51%, 548/1065) rated their lifestyle as unhealthy. The majority of them are senior physicians, 46% (250/548) consider their job to be a health hazard. The proportion of chief physicians and assistant physicians is only 21% (115/548) and 18% (98/548).

CONCLUSION

Guidelines for standardizing the perioperative protection of German surgeons are desirable. Health-promoting behavior could have a positive effect on the occupational safety of surgeons and ultimately also on patient safety. This can contribute to increasing the attractiveness of the profession "surgeon" in the long term.

Transferability of laparoscopic skills using the virtual reality simulator

BACKGROUND

Skill transfer represents an important issue in surgical education, and is not well understood. The aim of this randomized study is to assess the transferability of surgical skills between two laparoscopic abdominal procedures using the virtual reality simulator in surgical novices.

METHODS

From September 2016 to July 2017, 44 surgical novices were randomized into two groups and underwent a proficiency-based basic training consisting of five selected simulated laparoscopic tasks. In group 1, participants performed an appendectomy training on the virtual reality simulator until they reached a defined proficiency. They moved on to the tutorial procedural tasks of laparoscopic cholecystectomy. Participants in group 2 started with the tutorial procedural tasks of laparoscopic cholecystectomy directly. Finishing the training, participants of both groups were required to perform a complete cholecystectomy on the simulator. Time, safety and economy parameters were analysed.

RESULTS

Significant differences in the demographic characteristics and previous computer games experience between the two groups were not noted. Both groups took similar time to complete the proficiency-based basic training. Participants in group 1 needed significantly less movements (388.6 ± 98.6 vs. 446.4 ± 81.6; P < 0.05) as well as shorter path length (810.2 ± 159.5 vs. 945.5 ± 187.8 cm; P < 0.05) to complete the cholecystectomy compared to group 2. Time and safety parameters did not differ significantly between both groups.

CONCLUSION

The data demonstrate a positive transfer of motor skills between laparoscopic appendectomy and cholecystectomy on the virtual reality simulator; however, the transfer of cognitive skills is limited. Separate training curricula seem to be necessary for each procedure for trainees to practise task-specific cognitive skills effectively. Mentoring could help trainees to get a deeper understanding of the procedures, thereby increasing the chance for the transfer of acquired skills.

Impaired laparoscopic performance of novice surgeons due to phone call distraction: a single-centre, prospective study

BACKGROUND

Distractions such as phone calls during laparoscopic surgery play an important role in many operating rooms. The aim of this single-centre, prospective study was to assess if laparoscopic performance is impaired by intraoperative phone calls in novice surgeons.

METHODS

From October 2015 to June 2016, 30 novice surgeons (medical students) underwent a laparoscopic surgery training curriculum including two validated tasks (peg transfer, precision cutting) until achieving a defined level of proficiency. For testing, participants were required to perform these tasks under three conditions: no distraction (control) and two standardised distractions in terms of phone calls requiring response (mild and strong distraction). Task performance was evaluated by analysing time and accuracy of the tasks and response of the phone call.

RESULTS

In peg transfer (easy task), mild distraction did not worsen the performance significantly, while strong distraction was linked to error and inefficiency with significantly deteriorated performance (P < 0.05). Precision cutting (difficult task) was not slowed down by mild distraction, but surgical and cognitive errors were significantly increased when participants were distracted (P < 0.05). Compared to mild distraction, participants reported a more severe subjective disturbance when they were diverted by strong distraction (P < 0.05).

CONCLUSION

Our data reveals that phone call distractions result in impaired laparoscopic performance under certain circumstances. To ensure patient safety, phone calls should be avoided as far as possible in operating rooms.

Quality and outcomes of synchronous two-team Ivor-Lewis oesophagectomy: Revisiting a variant technique

BACKGROUND AND OBJECTIVES

In 1975, a modification of popular two-stage Ivor-Lewis oesophagectomy was published with synchronous resection in chest and abdomen. As data on this technique are rare and inconsistent, we aimed to investigate safety, feasibility, and outcome of this approach.

METHODS

Outcome of 201 patients undergoing synchronous oesophagectomy from 2000 to 2013 was analysed retrospectively. Two groups (early: 2000-2006; late: 2007-2013) were analysed to allow comparison of outcome over time.

RESULTS

Patients in the later period had fewer respiratory comorbidities (P = 0.010), median blood loss decreased significantly over time while lymph node yield increased (P < 0.001). Overall complications occurred in 58.9 (early) versus 51.7% (late) of patients (P = 0.320), anastomotic leaks in 14.3 versus 6.7% (P = 0.112), respiratory complications in 48.2 versus 34.8% (P = 0.063). Thirty-day/90-day mortality was 2.7% versus 3.4, respectively, 8.1% versus 6.8% (P ≤ 0.793). Long-term survival was better in the later cohort (P = 0.004).

CONCLUSIONS

Our data of 201 patients over a period of 14 years suggests that this technique is a quick, feasible, safe, and reasonable alternative to standard two-stage Ivor-Lewis oesophagectomy. Quality of this approach and ultimate outcomes have improved over time, with similar complication rates/outcomes to literature accepted standards for two-stage approach, especially in the later time period. J. Surg. Oncol. 2016;114:719-724. © 2016 Wiley Periodicals, Inc.

A Study of Normothermic Hemoperfusion of the Porcine Pancreas and Kidney

Normothermic machine perfusion has enormous potential to improve organ preservation and expand the organ donor pool. It is well established in other organs but not the pancreas, which has especially strict organ acceptance criteria. We established a model of normothermic hemoperfusion of the porcine pancreas with and without addition of the kidney as a dialysis organ. Four pancreases were harvested and perfused for 120 min with autologous whole blood at body temperature, two with parallel perfusion of the kidney and two without. The organs and perfusion circuit were evaluated for gross appearance, pH, histology and perfusion parameters. The organs maintained steadily increasing flow rate and perfusion pressure. Gross appearance of the organs was stable but appeared grossly ischemic toward the end of the perfusion period. Histology demonstrated necrosis centered in acinar tissue but islet cells were preserved. pH was significantly alkalotic toward the end of the perfusion, likely due to pancreatic tissue damage. Addition of the kidney did not result in significant improvement of the acid-base environment in this small series. In conclusion, normothermic perfusion of the pancreas is still in the experimental stages but holds great potential. Further studies to optimize perfusion parameters will significantly improve results. Parallel perfusion of the kidney may facilitate improvement in the acid-base environment.

[Surgical Training in Germany: Desire and Reality]

BACKGROUND

In-house surgical education and practical training of surgical skills are inhomogeneous in German hospitals and vary greatly in terms of teaching content and forms. The present survey provides an overview of the currently practiced surgical education and practical training of surgical skills in German hospitals.

MATERIAL AND METHODS

An online survey was performed among members of the "Deutsche Gesellschaft für Allgemein- und Viszeralchirurgie" (DGAV). It was a prospective data collection, divided into the following two groups: "junior physicians/consultants/senior physicians" and "chief physicians". The questionnaire consisted of 30 questions concerning the frequency, type and quality of in-house surgical education and practical training of surgical skills in German hospitals.

RESULTS

A total of 325 physicians participated in the survey, including 61 chief physicians and 264 junior physicians/consultants/senior physicians. Amongst the participants, 107 (33 %) worked in university hospitals, 57 (18 %) in maximum care clinics, 73 (22 %) in major regional hospitals with specialised medical services and 88 (27 %) in basic care facilities. 199 (75.4 %) of the junior physicians/consultants/senior physicians reported a regular, 57 (21.6 %) an irregular and 8 (3.0 %) no formal surgical education or practical training of surgical skills in their hospitals. Assistance in substeps of an operation was considered to be very important by 72 % of the survey participants. Similarly, 71 % rated the practical teaching of basic surgical skills as very important. Furthermore, we investigated the availability of theoretical and practical training offerings as well as satisfaction with educational measures and their importance as assessed by the respondents.

SUMMARY

The present survey illustrates the current state of surgical education and training in German hospitals. An implementation of pragmatic approaches such as the assistance in substeps of an operation and guided practical training of surgical skills might help to improve the satisfaction of physicians undergoing surgical training.

Procalcitonin--a Marker for Anastomotic Insufficiency after Pancreatoduodenectomy?

BACKGROUND

Anastomotic insufficiency after pancreatoduodenectomy (PD) represents a major complication in pancreatic surgery. Early detection and treatment of pancreatic fistulas (PF) are essential for the outcome of affected patients. Procalcitonin (PCT) is a biochemical marker which allows detection of bacterial infections. The aim of this study was to evaluate if PCT is suitable for early detection of PF after PD.

METHODS

In this prospective study patients undergoing PD from 08/2010 to 09/2012 were included into three groups: (1) patients without complications (n = 19), (2) patients with postoperative infections (n = 14) and (3) PF (n = 7). Using a defined study protocol, clinical (e.g., vital signs, drain fluid, etc.) and laboratory parameters (full blood count, inflammatory markers) were assessed daily for the first ten postoperative days.

RESULTS

76 patients were assessed. 40 (52.6%) patients underwent PD and were included. CRP and PCT demonstrated an initial peak at the 1st to 3rd postoperative day with subsequent normalization. Patients with postoperative infections and PF showed a significant increase of PCT and CRP (p < 0.05) compared to patients without complications. Leucocyte counts demonstrated a variance in all three groups and clinical use for detection of complications was not evident.

CONCLUSIONS

Patients with a postoperative complication revealed significantly increased levels of PCT and CRP without the expected normalization. PCT and/or CRP did not enable a distinction between patients with PF or postoperative infections. Thus, PCT does not seem to be suitable for detecting PF after PD and its use in the postoperative course after PD cannot be recommended.

Laparoscopic splenectomy for medically refractory immune thrombocytopenia (ITP): a retrospective cohort study on longtime response predicting factors based on consensus criteria

BACKGROUND

Laparoscopic splenectomy has been proposed to be the standard therapy for adult patients with medically refractory immune thrombocytopenia (ITP). However, due to inconsistent definitions of response, variable rates of long term response have been reported. Furthermore, new medical treatment options are currently challenging the role of splenectomy. The aims of this study were to (1) analyze long term response after splenectomy according to recently defined consensus criteria, (2) identify possible predictive response factors.

METHODS

A case series of 72 consecutive patients with ITP undergoing laparoscopic splenectomy was retrospectively studied using univariate and multivariate analysis as well as logrank tests.

RESULTS

Median follow-up was 32 (2-110) months. Mortality was 0% and morbidity was 8.2%. Response to splenectomy was achieved in of 63/72 patients (87.5%). Loss of response occurred in 19/63 (30.2%) in median after 3 (range 2-42) months. Preoperative platelet counts after boosting with steroids and immunoglobulins as well as the postoperative rise in platelet counts were statistically significant factors for response upon both univariate and multivariate analysis, whereas age, gender, body mass index, ASA classification, disease duration, accessory spleens, splenic weight, conversion to open surgery, or perioperative complications were not. Patients with a postoperative rise in platelet counts >150,000/μL had a significant better chance on stable long term response than those with a smaller increment (P < 0.001).

CONCLUSIONS

Laparoscopic splenectomy is an effective and safe treatment option in order to obtain stable long term response in patients with ITP. Perioperative platelet counts are predictive factors of long term response.

Pancreatoduodenectomy--current status of surgical and perioperative techniques in Germany

BACKGROUND

Pancreatoduodenectomy in Germany is performed by a broad range of hospitals. A diversity of operative techniques is employed as no guidelines exist for intra- and perioperative management. We carried out a national survey to determine the de facto German standards for pancreatoduodenectomy, assess quality assurance measures, and identify relevant issues for further investigation.

METHODS

A questionnaire evaluating major outcome variables, case load, preferred surgical procedures, and perioperative management during pancreatoduodenectomy was developed and sent to 211 German hospitals performing >12 pancreatoduodenectomies per year (requirement for certification as a pancreas center). Statistical analysis was carried out using the Fisher Exact, Mann-Whitney U, and Spearman tests.

RESULTS

The final response rate was 86 % (182/211). The preferred technique and de facto German standard for pancreatoduodenectomy was pylorus-preserving pancreatoduodenectomy with pancreatojejunostomy carried out via duct-to-mucosa anastomosis with interrupted sutures using PDS 4.0. The minority of German pancreas centers were certified (18-48 %). The certification rate increased with higher capacity levels and case load (P < 0.05); however, significant correlations between the fistula rate and hospital case load, hospital capacity level, or hospital certification status were not seen.

CONCLUSION

This study revealed a distinct variety of management strategies for pancreatic surgery and available evidence-based data was not necessarily translated into clinical practice. The limited certification rate represented a shortcoming of quality assurance. The data emphasize the need for further trials to answer the questions whether hospital certifications and omission of drains improve outcome after pancreatoduodenectomy and for the establishment of guidelines for pancreatoduodenectomy.

[Advances, limitations and prospects of oncological liver surgery]

Modern oncological liver surgery continues to push the limits of resectability by incorporating an array of new developments in the fields of surgery, anaesthesia and intensive care, oncology, radiology and transplantation medicine. New criteria for determining the resectability of primary and secondary liver tumours have been developed and introduced into national consensus guidelines. Modern tools for improving oncological outcome include the rapid induction of liver hypertrophy prior to major liver resection, downstaging of tumours with advanced chemotherapy protocols, minimally invasive local therapies like radiofrequency ablation and chemo- or radioembolisation, and liver transplantation for non-resectable hepatocellular carcinoma.

Epigenetic regulation and role of metastasis suppressor genes in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is distinguished by rapid dissemination. Thus, genetic and/or epigenetic deregulation of metastasis suppressor genes (MSG) is a likely event during early pancreatic carcinogenesis and a potential diagnostic marker for the disease. We investigated 9 known MSGs for their role in the dissemination of PDAC and examined their promoters for methylation and its use in PDAC detection.

METHODS

MRNA expression of 9 MSGs was determined in 18 PDAC cell lines by quantitative RT-PCR and promoter methylation was analyzed by Methylation Specific PCR and validated by Bisulfite Sequencing PCR. These data were compared to the cell lines' in vivo metastatic and invasive potential that had been previously established. Statistical analysis was performed with SPSS 20 using 2-tailed Spearman's correlation with P < 0.05 being considered significant.

RESULTS

Complete downregulation of MSG-mRNA expression in PDAC cell lines vs. normal pancreatic RNA occurred in only 1 of 9 investigated genes. 3 MSGs (CDH1, TIMP3 and KiSS-1) were significantly methylated. Methylation only correlated to loss of mRNA expression in CDH1 (P < 0.05). Bisulfite Sequencing PCR showed distinct methylation patterns, termed constant and variable methylation, which could distinguish methylation-regulated from non methylation-regulated genes. Higher MSG mRNA-expression did not correlate to less aggressive PDAC-phenotypes (P > 0.14).

CONCLUSIONS

Genes with metastasis suppressing functions in other tumor entities did not show evidence of assuming the same role in PDAC. Inactivation of MSGs by promoter methylation was an infrequent event and unsuitable as a diagnostic marker of PDAC. A distinct methylation pattern was identified, that resulted in reduced mRNA expression in all cases. Thus, constant methylation patterns could predict regulatory significance of a promoter's methylation prior to expression analysis and hence present an additional tool during target gene selection.

Epigenetic markers for chemosensitivity and chemoresistance in pancreatic cancer--a review

Adjuvant first-line gemcitabine monochemotherapy presents a standard treatment for patients with advanced pancreatic adenocarcinoma and improves overall survival in chemosensitive patients. Nonetheless, 6-month progression-free survival remains below 15%, despite interdisciplinary approaches. The success of gemcitabine treatment is disappointing and-in the absence of reliable tumor markers--challenging to quantify. Epigenetic alterations have been recently identified to take on important roles in cancer development and possibly cancer treatment. In this context, microRNAs are becoming increasingly acknowledged as useful biomarkers for classifying cancers and providing information on their chemo- and radiosensitivity. This review illustrates the potential of genetic and epigenetic markers in the prediction of chemosensitivity in pancreatic cancer patients and in the monitoring of their response rates to adjuvant therapy.

EP300--a miRNA-regulated metastasis suppressor gene in ductal adenocarcinomas of the pancreas

Genetic and epigenetic alterations during development of pancreatic ductal adenocarcinomas (PDACs) are well known. This study investigates genetic and epigenetic data together with tumor biology to find specific alterations responsible for metastasis formation. Using 16 human PDAC cell lines in a murine orthotopic PDAC model, local infiltration and metastatic spread were assessed by standardized dissemination scores. The cell lines were further classified into 3 hierarchical groups according to their metastatic potential. Their mRNA and microRNA (miRNA) expression was profiled via mRNA-microarray as well as Taqman Low Density Array, and validated by single quantitative RT-PCR and Western blotting. In the highly metastatic group, a significant induction of EP300 targeting miRNAs miR-194 (fold change: 26.88), miR-200b (fold change: 61.65), miR-200c (fold change: 19.44) and miR-429 (fold change: 21.67) (p < 0.05) was detected. Corresponding to this, decreased expression of EP300 mRNA (p < 0.0001) and protein (p < 0.05) were detected in the highly metastatic PDAC cell lines with liver metastases compared to the nonmetastatic or marginally metastatic cell lines, while no correlation with local tumor growth was found. In conclusion, epigenetic alterations with upregulated EP300 targeting miRNAs miR-194, miR-200b, miR-200c and miR-429 are related to reduced EP300 mRNA and protein in PDAC. These results demonstrate that miRNAs might be able to modulate the expression of metastasis-specific suppressor genes and metastatic behavior in PDAC, suggesting diagnostic and therapeutic opportunities for EP300 and its targeting miRNAs in PDAC.

Analyzing miRNAs in ductal adenocarcinomas of the pancreas

BACKGROUND

MicroRNAs (miRNAs) have gained attention as an epigenetic component involved in the development of pancreatic ductal adenocarcinoma (PDAC). Several methods for miRNA profiling are in common use, but the validity of these methods is not defined. The aim of this study was to define the optimal method for miRNA detection in PDAC.

METHODS

miRNA expression was determined using different and partially redundant methods (miRNA microarray, TaqMan low density array (TLDA), single tube quantitative RT-PCR). The data from different methods were statistically evaluated and tested for intermethodic consistency and reliability of the results. Finally, the miRNA expression status and the cell lines' ability to metastasize were correlated.

RESULTS

Comparing low and high metastatic cells, miRNA-microarrays identified fewer differentially expressed and only upregulated miRNAs (n=27; 27 up-regulated) compared with TLDAs (n=54; 19 up- and 35 down-regulated). Evaluating miRNAs that target tumor suppressor genes, expression of all single tube quantitative real-time reverse transcriptase PCR (qRT-PCR) validated miRNAs was detected to be significantly altered in TLDA analysis (100%). MiRNA microarrays detected only 25% of qRT-PCR validated miRNAs. Furthermore, results from TLDA analysis correlated well with data from qRT-PCR and presented ΔΔCt values from 3.5±1.86 (range 0.8-5.62) compared with 3.74±1.86 (range 0.78-5.95) in qRT-PCR.

CONCLUSION

Notable differences comparing data obtained from different screening methods were found. While TLDA and qRT-PCR correlated well in quantity and quality of the measured miRNAs, several tumor suppressor gene targeting and down-regulated miRNAs were not detected by miRNA-microarrays. This heterogeneity shows that care must be exercised when comparing results from different methods in PDAC.

Metastatic tumor cell arrest in the liver-lumen occlusion and specific adhesion are not exclusive

INTRODUCTION

In metastasis research, modern microscopic techniques shed a new light on the mechanisms of metastatic tumor cell arrest in the microcirculation of potential metastasis target organs. In this study, we differentiated the contribution of mechanical cell arrest, determined as lumen occlusion of liver sinusoids by tumor cells, and specific cell adhesion mediated by integrins for the arrest of human colon cancer cells in rat livers.

MATERIALS AND METHODS

Using in vivo microscopy, the diameters of liver sinusoids of two different rat strains (CD, 250-300 g and RNU, 80-120 g) were determined. Cells (HT-29LMM) were intracardially injected, and the numbers of arrested cells and the rates of sinusoid occluding cells were determined.

RESULTS

Mean sinusoid diameter in CD rats was 6.98 +/- 1.42 microm compared to 5.14 +/- 1.11 microm in RNU rats (p < 0.001). The numbers of arrested tumor cells and the rates of extravasated tumor cells did not differ between the two rat strains. Nevertheless, 5 and 30 min after cell injection, 35 +/- 15% and 19 +/- 8% of arrested cells, respectively, appeared lumen occluding in RNU rats and 9 +/- 6% and 3 +/- 3%, respectively, in CD rats (p < 0.05). Despite the higher rates of lumen occlusive cells in RNU rats, inhibition of beta-1 or beta-4 integrins significantly impaired cell arrest by 30-60% in both strains.

DISCUSSION

In summary, these results demonstrate that lumen occlusion alone, as determined by in vivo microscopy, is insufficient to establish stable tumor cell arrest of colon carcinoma cells in metastatic target organs and does therefore not rule out the requirement of specific adhesive interactions for tumor cell arrest in the microcirculation.

Involvement of CD40 targeting miR-224 and miR-486 on the progression of pancreatic ductal adenocarcinomas

BACKGROUND

Genetic and epigenetic alterations during development of pancreatic ductal adenocarcinomas (PDAC) are well known. Genetic and epigenetic data were correlated with tumor biology to find specific alterations responsible for invasion and metastasis in pancreatic ductal adenocarcinomas.

METHODS

A total of 16 human PDAC cell lines were used in murine orthotopic PDAC models. By means of standardized dissemination scores, local invasion and metastatic spread were assessed. mRNA and microRNA expression were studied by microarray and TaqMan low-density array. Quantitative real-time-polymerase chain reaction and flow cytometry were used for expression validation.

RESULTS

CD40 was detected as a relevant target gene for differentially expressed miRNAs observed in highly invasive and metastatic PDAC only. A significant overexpression (P < .05) of CD40-related miRNAs miR-224 and miR-486 was detected in highly invasive and metastatic PDAC, whereas CD40 mRNA expression was not significantly altered. Instead, CD40 protein expression at cell surfaces of these highly invasive and metastatic PDAC was significantly reduced (P < .01).

CONCLUSIONS

Epigenetic alterations with upregulated CD40-targeting miR-224 and miR-486 are related to downregulated CD40 protein expression at cell surfaces in highly invasive and metastatic PDAC. Thus, miRNA-regulated CD40 expression seems to play an important role in progression of PDAC. These data suggest a diagnostic and therapeutic potential for CD40 and/or its targeting miRNAs in PDAC.

Expression of tight and adherens junction proteins in ulcerative colitis associated colorectal carcinoma: upregulation of claudin-1, claudin-3, claudin-4, and beta-catenin

BACKGROUND

Tight junction (TJ) proteins play a critical role in cellular adhesion, glandular differentiation, and cellular proliferation. The function of these proteins is compromised in a number of intestinal diseases, including ulcerative colitis that has an increased incidence for colorectal carcinoma (CAC). The aim of this study was to determine the expression of TJ proteins, claudin-1-4, occludin, ZO-1, and the adherens junction (AJ) protein beta-catenin in CAC.

METHODS

Sixteen colectomy specimens with CAC, adjoining intraepithelial neoplasia, and normal mucosa were studied by immunofluorescence. A semiquantitative evaluation of all investigated proteins was performed by scoring the staining intensity, and the TJ and AJ protein expression in neoplastic cells was compared to normal and intraepithelial neoplastic colonic mucosa.

RESULTS

Using an intensity scoring system, mucosa of crypts and surfaces of CAC exhibited significantly elevated expression levels of claudin-1, claudin-3, claudin-4, and beta-catenin compared to intraepithelial neoplasia and normal mucosa (p<0.05). These data were confirmed by a comparative score. The expression of claudin-2, occludin, and ZO-1 showed no differences between the groups.

CONCLUSION

TJ proteins claudin-1, claudin-3, claudin-4, and the AJ protein beta-catenin are overexpressed in CAC. This suggests that these proteins may become potential markers and targets in CAC.

Inhibition of interleukin-6-transsignaling via gp130-Fc in hemorrhagic shock and sepsis

BACKGROUND

Immune function after hemorrhagic shock and subsequent sepsis is characterized by an early proinflammatory burst of IL-6, and high IL-6 levels have been linked to high mortality after trauma and in sepsis. Trans-signaling is defined as the activation of cells that do not express the membrane bound IL-6 receptor by the complex of IL-6 and the soluble IL-6 receptor (sIL-6R). Gp130-Fc is able to bind the IL-6/sIL-6R complex, and beneficial effects of IL-6 blockade in chronic inflammatory diseases have been shown. The first aim of this study was to investigate the potential effect of a gp130 blockade via the gp130-Fc antibody causing impairment of IL-6 signaling. The second aim was to find out what role the IL-6/sIL-6R complex can play in the context of hemorrhagic shock and subsequent sepsis as an acute inflammatory disease.

MATERIAL AND METHODS

Male CBA/J mice were subjected to hemorrhagic shock (35+/-5 mmHg for 90min and fluid resuscitation) or sham operation. At resuscitation each animal received either 0.5mg gp130-Fc or placebo (PL) i.p. At 48 h after resuscitation, both splenocytes and peritoneal macrophages (pMphi) were harvested or polymicrobial sepsis was induced by cecal ligation and puncture. Survival over 10 d was determined. Release of IL-6, TNF-alpha, and IL-10 of pMphi and release of IL-2, IL-10, and IFN-gamma of splenocytes was assessed by ELISA. Proliferation of splenocytes and their morphologic damage were determined.

RESULTS

Binding of the IL-6/sIL-6R complex by gp130-Fc led to significant lower IL-6 levels compared with placebo treated animals. Placebo treated males showed depressed proinflammatory immune response (IL-2, IL-6) after hemorrhagic shock. While splenocyte proliferation was significantly reduced directly after hemorrhagic shock and restored after 48 h by gp130-Fc, pMphi cytokine release was not influenced. Finally, survival appeared to be unaffected.

CONCLUSION

Transsignaling does not seem to play a pivotal role in the development of the immune dysfunction and mortality in our model of hemorrhage and subsequent sepsis.

HYDROXYETHYL STARCH NORMALIZES PLATELET AND LEUKOCYTE ADHESION WITHIN PULMONARY MICROCIRCULATION DURING LPS-INDUCED ENDOTOXEMIA

Growing evidence supports substantial pathophysiological impact of platelets and their interactions on the development of septic lung failure. We developed a rat model of endotoxemia for direct in situ visualization of pulmonary microcirculation by in vivo fluorescence videomicroscopy. Male Sprague-Dawley rats were assigned to control, endotoxemia (Escherichia coli LPS, 15 mg/kg, i.v.), and fluid management for treatment of LPS-induced hypovolemia (Ringer lactate, hydroxyethyl starch [HES] 6%) groups (n = 7 each). Leukocytes were labeled in vivo by rhodamine, and 5 x 10(6) Calcein-AM-labeled nonactivated platelets were injected. Microcirculatory parameters (vessel diameter, ventilation-perfusion ratio) and adhesive characteristics of platelets and leukocytes (velocity, rolling, sticking) within the pulmonary microcirculation were quantified after endotoxin application under various regimens of fluid substitution for 60 min. A reduction of cell velocity and enhanced cell adhesion was seen in leukocytes and platelets (P < 0.05) after LPS injection. Fluid treatment with HES 6% resulted in a significant increase of platelet's velocity compared with the LPS group (442.86 +/- 20.60 vs. 343.93 +/- 11.17; P < 0.05), whereas Ringer lactate showed no beneficial effects. Similarly, HES 6% normalized LPS-induced platelet rolling and sticking as well as alterations in ventilation-perfusion ratio. Using direct visualization of the pulmonary microcirculation, we observed that platelet and leukocyte interactions are enhanced in the lung during LPS endotoxemia. Fluid therapy with HES 6% seems to have restorative effects on these cellular functions within the pulmonary microcirculation.

Age- and gender-related differences of the immune function in a murine model of hemorrhagic shock: IL-10 restores immunodepression in aged females without reduction of mortality

INTRODUCTION

Interleukin-10 (IL-10) treatment has been shown to have beneficial effects on the immune function after hemorrhagic shock and to improve survival after subsequent sepsis in young male mice, but not in young females. Although it was demonstrated that the immune function under these conditions is reversed with age, it remains unclear whether the observed gender-related effect of IL-10 treatment continues to exist in aged mice.

MATERIALS AND METHODS

Aged male and female CBA/J mice (18-19 months) were subjected to hemorrhage (35 +/- 5 mmHg for 90 min) or sham operation. At resuscitation, each received either 10-microg recombinant murine (rm)IL-10 or placebo i.p. At 48 h after resuscitation, either the mice were killed and the plasma, splenic macrophages (sM phi), and splenocytes were harvested or polymicrobial sepsis was induced by cecal ligation and puncture (CLP). After CLP, either survival over 10 days was determined or, 4 h after CLP, tissues were again harvested and cytokine-released in vitro were assessed by enzyme-linked immunosorbent assay.

RESULTS

Early IL-10 treatment restored depressed proinflammatory immune response (TNF-alpha, IL-1 beta) and Th1 response of splenocytes in aged females after hemorrhage, whereas having no effects or having suppressive effects in aged males. Subsequent sepsis combined with placebo treatment led to a significant suppression of proinflammatory cytokine release of sM phi and a significant increase of Th2 response in both males and females associated with high mortality (80-100%, respectively) after CLP. These effects were not influenced by early rmIL-10 treatment.

CONCLUSION

After hemorrhage, early rmIL-10 treatment restored immune function in aged females, but not in males. However, in contrast to young mice, rmIL-10 treatment had no effect on survival and immune function after CLP in aged mice.