Moving translational mass spectrometry imaging towards transparent and reproducible data analyses: a case study of an urothelial cancer cohort analyzed in the Galaxy framework.

BACKGROUND: Mass spectrometry imaging (MSI) derives spatial molecular distribution maps directly from clinical tissue specimens and thus bears great potential for assisting pathologists with diagnostic decisions or personalized treatments. Unfortunately, progress in translational MSI is often hindered by insufficient quality control and lack of reproducible data analysis. Raw data and analysis scripts are rarely publicly shared. Here, we demonstrate the application of the Galaxy MSI tool set for the reproducible analysis of a urothelial carcinoma dataset. METHODS: Tryptic peptides were imaged in a cohort of 39 formalin-fixed, paraffin-embedded human urothelial cancer tissue cores with a MALDI-TOF/TOF device. The complete data analysis was performed in a fully transparent and reproducible manner on the European Galaxy Server. Annotations of tumor and stroma were performed by a pathologist and transferred to the MSI data to allow for supervised classifications of tumor vs. stroma tissue areas as well as for muscle-infiltrating and non-muscle infiltrating urothelial carcinomas. For putative peptide identifications, m/z features were matched to the MSiMass list. RESULTS: Rigorous quality control in combination with careful pre-processing enabled reduction of m/z shifts and intensity batch effects. High classification accuracy was found for both, tumor vs. stroma and muscle-infiltrating vs. non-muscle infiltrating urothelial tumors. Some of the most discriminative m/z features for each condition could be assigned a putative identity: stromal tissue was characterized by collagen peptides and tumor tissue by histone peptides. Immunohistochemistry confirmed an increased histone H2A abundance in the tumor compared to the stroma tissues. The muscle-infiltration status was distinguished via MSI by peptides from intermediate filaments such as cytokeratin 7 in non-muscle infiltrating carcinomas and vimentin in muscle-infiltrating urothelial carcinomas, which was confirmed by immunohistochemistry. To make the study fully reproducible and to advocate the criteria of FAIR (findability, accessibility, interoperability, and reusability) research data, we share the raw data, spectra annotations as well as all Galaxy histories and workflows. Data are available via ProteomeXchange with identifier PXD026459 and Galaxy results via https://github.com/foellmelanie/Bladder_MSI_Manuscript_Galaxy_links . CONCLUSION: Here, we show that translational MSI data analysis in a fully transparent and reproducible manner is possible and we would like to encourage the community to join our efforts.

Surgeon vs Pathologist for Prediction of Pancreatic Fistula: Results from the Randomized Multicenter RECOPANC Study.

BACKGROUND: Surgically assessed pancreatic texture has been identified as the strongest predictor of postoperative pancreatic fistula. However, texture is a subjective parameter with no proven reliability or validity. Therefore, a more objective parameter is needed. In this study, we evaluated the fibrosis level at the pancreatic neck resection margin and correlated fibrosis and all clinico-pathologic parameters collected over the course of the Pancreatogastrostomy vs Pancreatojejunostomy for RECOnstruction (RECOPANC) study. STUDY DESIGN: The RECOPANC trial was a multicenter randomized prospective trial of patients undergoing pancreatoduodenectomy. There were 261 hematoxylin and eosin-stained slides allocated for histopathologic analyses. Pancreatic fibrosis was scored from 0 to III (no fibrosis up to severe fibrosis) by 2 blinded independent pathologists. All variables possibly associated with POPF were entered into a generalized linear model for multivariable analysis. RESULTS: The fibrosis grade and pancreatic texture were scored in all 261 patients. In POPF B/C (postoperative pancreatic fistula grade B or C) patients, 71% had a soft pancreas, and fibrosis grades were distributed as follows: 48% with score 0, 28% with score I, 20% with score II, and 7% with score III, respectively. Fibrosis grading showed substantial inter-rater reliability (kappa = 0.74) and correlated positively with hard pancreatic texture (p < 0.05). In univariable analysis, area under the curve (AUC) for POPF B/C prediction was higher for fibrosis grade than for pancreatic texture (0.71 vs 0.59). In multivariate analysis, the following predictors were selected: sex, surgeon volume, pancreatic texture, and fibrosis grade. However, the addition of pancreatic texture only led to an incremental improvement (AUC 0.794 vs 0.819). CONCLUSIONS: Histologically evaluated pancreatic fibrosis is an easily applicable and highly reproducible POPF predictor and superior to surgically evaluated pancreatic texture. Future studies might use fibrosis grade for risk stratification in pancreatoduodenectomy.

Cytopathological Heterogeneity of Circulating Tumor Cells in Non-metastatic Esophageal Adenocarcinoma.

BACKGROUND/AIM: The presence of circulating tumor cells (CTC) has been reported to have an impact on prognosis in different tumor entities. Little is known about CTC morphology and heterogeneity. PATIENTS AND METHODS: In a multicenter setting, pre-therapeutic peripheral blood specimens were drawn from patients with non-metastatic esophageal adenocarcinoma (EAC). CTCs were captured by size-based filtration (ScreenCell®), subsequently Giemsa-stained and evaluated by two trained readers. The isolated cells were categorized in groups based on morphologic criteria. RESULTS: Small and large single CTCs, as well as CTC-clusters, were observed in 69.2% (n=81) of the 117 specimens; small CTCs were observed most frequently (59%; n=69), followed by large CTCs (40%; n=47) and circulating cancer-associated macrophage-like cells (CAMLs; 34.2%, n=40). Clusters were rather rare (12%; n=14). CTC/CAML were heterogeneous in the cohort, but also within one specimen. Neither the presence of the CTC subtypes/CAMLs nor the exact cell count were associated with the primary clinical TNM stage. CONCLUSION: Morphologically heterogenic CTCs and CAMLs are present in patients with non-metastatic, non-pretreated EAC.

Conditional Gene Targeting Reveals Cell Type-Specific Roles of the Lysosomal Protease Cathepsin L in Mammary Tumor Progression.

Background: Cathepsin L (Ctsl) is a cysteine protease mainly located within the endosomal/lysosomal cell compartment. High expression of Ctsl indicates poor prognosis in human breast cancer. However, the cell type-specific Ctsl functions responsible for this association remain elusive. Methods: Because constitutive Ctsl-/- mice develop a complex phenotype, we developed a conditional model allowing for cell type-specific inactivation of Ctsl in mammary epithelium or myeloid cells in the transgenic mouse mammary tumor virus (MMTV)-polyoma middle T (PyMT) breast cancer model. Results: Ctsl ablation in mammary epithelial cells resulted in delayed initiation and end-stage of cancers. The latter displayed large dead cell areas. Inducible in vitro deletion of Ctsl in MMTV-PyMT-derived breast cancer cells revealed expansion of the acidic cell compartment, alteration of intracellular amino acid levels, and impaired mTOR signaling. In consequence, Ctsl-deficient cells exhibited slow growth rates and high apoptosis susceptibility. In contrast to Ctsl-deficient mammary epithelium, selective knockout of Ctsl in myeloid cells had no effects on primary tumors, but promoted lung metastasis formation. Conclusions: Our cell type-specific in vivo analysis provides strong evidence for a cancer cell-intrinsic, tumor-promoting role of Ctsl in primary breast cancer, whereas metastasis is negatively regulated by Ctsl expressed by bone marrow-derived cells.

Specific role of RhoC in tumor invasion and metastasis.

Rho GTPases are regulators of many cellular functions and are often dysregulated in cancer. However, the precise role of Rho proteins for tumor development is not well understood. In breast cancer, overexpression of RhoC is linked with poor prognosis. Here, we aim to compare the function of RhoC and its homolog family member RhoA in breast cancer progression. We established stable breast epithelial cell lines with inducible expression of RhoA and RhoC, respectively. Moreover, we made use of Rho-activating bacterial toxins (Cytotoxic Necrotizing Factors) to stimulate the endogenous pool of Rho GTPases in benign breast epithelial cells and simultaneously knocked down specific Rho proteins. Whereas activation of Rho GTPases was sufficient to induce an invasive phenotype in three-dimensional culture systems, overexpression of RhoA or RhoC were not. However, RhoC but not RhoA was required for invasion, whereas RhoA and RhoC equally regulated proliferation. We further identified downstream target genes of RhoC involved in invasion and identified PTGS2 (COX-2) being preferentially upregulated by RhoC. Consistently, the COX-2 inhibitor Celecoxib blocked the invasive phenotype induced by the Rho-activating toxins.

Anti-Phosphohistone H3-Positive Mitoses Are Linked to Pathological Response in Neoadjuvantly Treated Breast Cancer.

BACKGROUND: We evaluated breast cancer (BC) core biopsies taken before neoadjuvant chemotherapy (NACT) by immunohistochemistry using anti-phosphohistone H3 (PHH3) antibody to determine mitosis, and correlated the results to clinicopathological data and histopathological regression of resected tumor specimens after NACT. METHODS: 72 patients with either triple-negative (TN) or luminal type BC received NACT with epirubicin/cyclophosphamide (EC) and Taxotere®. Tumor regression was analyzed in resected specimens; pathological complete response (pCR) was achieved in 22.2%. Immunohistochemistry with PHH3 was performed on biopsy samples taken before treatment, and mitotic figures were evaluated in 10 high-power fields (HPF). RESULTS: PHH3-detected mitoses correlated significantly with tumor grading (p = 0.001). TNBC showed > 10 PHH3-positive mitoses/10 HPF significantly more frequently than luminal type BC (p = 0.003). Tumors with > 10 PHH3-positive mitoses/10 HPF achieved pCR significantly more often than those with ≤ 10 PHH3-positive mitoses/10 HPF (p = 0.031). Even luminal type BC with > 10 PHH3-positive mitoses/10 HPF was associated significantly with pCR compared to luminal type BC with ≤ 10 PHH3-positive mitoses/10 HPF (p = 0.016). CONCLUSION: NACT with EC and Taxotere is suitable for strong proliferating TNBC and luminal BC (> 10 PHH3-positive mitoses/10 HPF). Immunohistochemical determination of mitoses using anti-PHH3 antibody is a simple and robust method for predicting therapy response to NACT in BC tissue.

Author Correction: Pancreatic cancer: Circulating Tumor Cells and Primary Tumors show Heterogeneous KRAS Mutations.

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.

Validity Parameters of the Human Papillomavirus Detection Test Hybrid Capture 2 With and Without Cytology After Laser Destruction and Large Loop Excision of the Transformation Zone Treatment of High-Grade Cervical Intraepithelial Neoplasia Lesions.

OBJECTIVE: The aim of this study was to calculate the validity parameters of the Digene Hybrid Capture 2 (HC2) high-risk human papillomavirus DNA test with and without cytology in the follow-up examinations after laser treatment of the transformation zone or large loop excision of the transformation zone (LLETZ) for cervical intraepithelial neoplasia (CIN). METHODS: We performed a standardized follow-up examination in 113 postlaser and 153 post-LLETZ patients in our colposcopy clinic. Routine cytology, HC2 tests, and colposcopically-guided cervical biopsies were performed and sensitivity, specificity, and positive and negative predictive values were calculated using the histological cervical biopsy result as the criterion standard. RESULTS: After a median follow-up time of 25.5 months, the overall posttreatment recurrence/persistence rate of CIN 2 or higher (CIN 2+) was 24% after laser and 12.4% after Post-LLETZ treatment. Hybrid Capture 2 alone had a sensitivity/NPV of 70/88% in post-laser and 70/93% in post-LLETZ patients. Cytology alone had a sensitivity/NPV for CIN 2+ of 48/84% in post-laser and 58/91% in post-LLETZ patients. Combined testing of HC2 with cytology had a sensitivity/NPV of 81/92% in postlaser and 88/95% in post-LLETZ patients. DISCUSSION: In this test of cure study, combined testing of cytology with HC2 resulted in a high sensitivity and NPV. Hybrid Capture 2 and cytology-negative women may safely return to routine recall. Cytology alone is not an adequate follow-up strategy in postlaser patients.

Pancreatic cancer: Circulating Tumor Cells and Primary Tumors show Heterogeneous KRAS Mutations.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. Circulating tumor cells (CTC) in the blood are hypothesized as the means of systemic tumor spread. Blood obtained from healthy donors and patients with PDAC was therefore subject to size-based CTC-isolation. We additionally compared Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations in pancreatic CTC and corresponding tumors, and evaluated their significance as prognostic markers. Samples from 68 individuals (58 PDAC patients, 10 healthy donors) were analyzed; CTCs were present in patients with UICC stage IA-IV tumors and none of the controls (p < 0.001). Patients with >3 CTC/ml had a trend for worse median overall survival (OS) than patients with 0.3­3 CTC/ml (P = 0.12). Surprisingly, CTCs harbored various KRAS mutations in codon 12 and 13. Patients with a KRAS G12V mutation in their CTC (n = 14) had a trend to better median OS (24.5 months) compared to patients with other (10 months), or no detectable KRAS mutations (8 months; P = 0.04). KRAS mutations in CTC and corresponding tumor were discordant in 11 of 26 "tumor-CTC-pairs" (42%), while 15 (58%) had a matching mutation; survival was similar in both groups (P = 0.36). Genetic characterization, including mutations such as KRAS, may prove useful for prognosis and understanding of tumor biology.

Form follows function: Morphological and immunohistological insights into epithelial-mesenchymal transition characteristics of tumor buds.

In cancer biology, the architectural concept "form follows function" is reflected by cell morphology, migration, and epithelial-mesenchymal transition protein pattern. In vivo, features of epithelial-mesenchymal transition have been associated with tumor budding, which correlates significantly with patient outcome. Hereby, the majority of tumor buds are not truly detached but still connected to a major tumor mass. For detailed insights into the different tumor bud types and the process of tumor budding, we quantified tumor cells according to histomorphological and immunohistological epithelial-mesenchymal transition characteristics. Three-dimensional reconstruction from adenocarcinomas (pancreatic, colorectal, lung, and ductal breast cancers) was performed as published. Tumor cell morphology and epithelial-mesenchymal transition characteristics (represented by zinc finger E-box-binding homeobox 1 and E-Cadherin) were analyzed qualitatively and quantitatively in a three-dimensional context. Tumor buds were classified into main tumor mass, connected tumor bud, and isolated tumor bud. Cell morphology and epithelial-mesenchymal transition marker expression were assessed for each tumor cell. Epithelial-mesenchymal transition characteristics between isolated tumor bud and connected tumor bud demonstrated no significant differences or trends. Tumor cell count correlated significantly with epithelial-mesenchymal transition and histomorphological characteristics. Regression curve analysis revealed initially a loss of membranous E-Cadherin, followed by expression of cytoplasmic E-Cadherin and subsequent expression of nuclear zinc finger E-box-binding homeobox 1. Morphologic changes followed later in this sequence. Our data demonstrate that connected and isolated tumor buds are equal concerning immunohistochemical epithelial-mesenchymal transition characteristics and histomorphology. Our data also give an insight in the process of tumor budding. While there is a notion that the epithelial-mesenchymal transition zinc finger E-box-binding homeobox 1-E-Cadherin cascade is initiated by zinc finger E-box-binding homeobox 1, our results are contrary and outline other possible pathways influencing the regulation of E-Cadherin.

The Prognostic Impact of the Carcinoembryonic Antigen in Ampullary Cancer - A Retrospective Single Center Study.

Background: Carcinoembryonic antigen cell adhesion molecule (CEA) is a commonly immunohistochemically used antibody in pathological routine diagnostics with an overexpression in different cancers. We aimed to examine the immunohistochemically detectable CEA level in ampullary cancer and to correlate it with clinico-pathological data. Methods: Shot-gun proteomics revealed CEA in undifferentiated ampullary cancer cell lines. Next, tumor tissue of 40 ampullary cancers of a retrospective single center cohort of 40 patients was stained immunohistochemically for CEA; CEA expression was determined and correlated with clinico-pathological data. Results: Thirty-six patient specimens were included in statistical analysis. CEA expression and lymph node ratio (LNR) were the only independent predictors of overall survival in multivariate analysis. Conclusion: To our knowledge, cell line and patient cohorts are the largest and characterized cohorts examined for CEA so far. Hereby, CEA expression in ampullary cancer cells permits an estimation of outcome and suggests an opportunity for individualized CEA-directed therapy. Further trials with larger cohorts are needed to verify our results and to integrate CEA immunohistochemistry into clinical routine.

Manual Lymphatic Drainage after Subepidermal Tracer Injection Optimizes Results of Sentinel Lymph Node Labeling in Primary Breast Cancer.

INTRODUCTION: Our aim was to assess the practicability and reliability of a novel labeling regime for axillary sentinel lymph nodes (SLNs) in early breast cancer. METHODS: 362 patients with early breast cancer (bilateral in 9 cases, giving a total of 371 cases) underwent intradermal radio tracer injection with simultaneous manual lymphatic drainage. SLN biopsy was performed within 24 h. For retrospective analysis, data were extracted from patient's records. RESULTS: At least 1 SLN was detected intraoperatively in 369 cases (99.5%, range 1-9 nodes). This node was metastatic in 88 and unaffected in 281 cases. Coincidentally removed but unlabeled lymph nodes were affected in 3 cases in which the SLN was unaffected (3/153 = 2%). In all cases, on histological evaluation, tissue removed as SLN contained lymph nodes. After a period of 69.5 months (median 1.7-115.8 months), no axillary recurrences were observed in 213 patients. CONCLUSION: Manual lymphatic drainage is a simple technique that leads to an extremely high pick-up rate of axillary SLNs after subepidermal radio tracer injection. If unaffected, this node correctly predicts nodal-negative disease in 98% of cases studied.

Mesopancreatic Stromal Clearance Defines Curative Resection of Pancreatic Head Cancer and Can Be Predicted Preoperatively by Radiologic Parameters: A Retrospective Study.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a strong fibrotic stromal reaction and diffuse growth pattern. Peritumoral fibrosis is often evident during surgery but only distinguishable from tumor by microscopic examination. The aim of this study was to investigate the role of clearance of fibrotic stromal reaction at the mesopancreatic resection margin as a criterion for radical resection and preoperative assessment of resectability.Mesopancreatic stromal clearance status (S-status) was defined as the presence or absence (S+/S0) of fibrotic stromal reaction at the mesopancreatic resection margin. Detailed retrospective clinicopathologic re-evaluation of margin status and preoperative cross-sectional imaging was performed in a cohort of 91 patients operated for pancreatic head PDAC from 2001 to 2011.Conventional margin positive resection (R+, tumor cells directly at the margin) was found in 36%. However, S-status further divided the margin negative (R0) group into patients with median survival of 14 months versus 31 months (S+ versus S0, P = 0.005). Overall rate of S+ was 53%. S-status and lymph node ratio constituted the only independent predictors of survival. Stranding of the superior mesenteric artery fat sheath was the only independent radiologic predictor of S+ resection, and achieved a 71% correct prediction of S-status.Mesopancreatic stromal clearance is a major determinant of curative resection in PDAC, and preoperative prediction by cross-sectional imaging is possible, setting the basis for a new definition of borderline resectability.

Response of esophageal cancer cells to epigenetic inhibitors is mediated via altered thioredoxin activity.

We previously showed that histone deacetylase inhibitor (HDACi) and 5-azacytidine (AZA) treatment selectively induced cell death of esophageal cancer cells. The mechanisms of cancer selectivity, however, remained unclear. Here we examined whether the cancer selectivity of HDACi/AZA treatment is mediated by the thioredoxin (Trx) system and reactive oxygen species (ROS) in esophageal cancer cells. For this, we first analyzed human tissue specimens of 37 esophageal cancer patients by immunohistochemistry for Trx, Trx-interacting protein (TXNIP) and Trx reductase (TXNRD). This revealed a loss or at least reduction of nuclear Trx in esophageal cancer cells, compared with normal epithelial cells (P<0.001). Although no differences were observed for TXNIP, TXNRD was more frequently expressed in cancer cells (P<0.001). In the two main histotypes of esophageal squamous cell carcinomas (ESCCs, n=19) and esophageal adenomcarcinomas (EAC, n=16), similar Trx, TXNIP and TXNRD expression patterns were observed. Also in vitro, nuclear Trx was only detectable in non-neoplastic Het-1A cells, but not in OE21/ESCC or OE33/EAC cell lines. Moreover, the two cancer cell lines showed an increased Trx activity, being significant for OE21 (P=0.0237). After treatment with HDACi and/or AZA, ROS were exclusively increased in both cancer cell lines (P=0.048-0.017), with parallel decrease of Trx activity. This was variably accompanied by increased TXNIP levels upon AZA, MS-275 or MS-275/AZA treatment for 6 or 24 h in OE21, but not in Het-1A or OE33 cells. In summary, this study evaluated Trx and its associated proteins TXNIP and TXNRD for the first time in esophageal cancers. The analyses revealed an altered subcellular localization of Trx and strong upregulation of TXNRD in esophageal cancer cells. Moreover, HDACi and AZA disrupted Trx function and induced accumulation of ROS with subsequent apoptosis in esophageal cancer cells exclusively. Trx function is hence an important cellular mediator conferring non-neoplastic cell resistance for HDACi and/or AZA.

Selective inhibition of esophageal cancer cells by combination of HDAC inhibitors and Azacytidine.

Esophageal cancers are highly aggressive tumors with poor prognosis despite some recent advances in surgical and radiochemotherapy treatment options. This study addressed the feasibility of drugs targeting epigenetic modifiers in esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) cells. We tested inhibition of histone deacetylases (HDACs) by SAHA, MS-275, and FK228, inhibition of DNA methyltransferases by Azacytidine (AZA) and Decitabine (DAC), and the effect of combination treatment using both types of drugs. The drug targets, HDAC1/2/3 and DNMT1, were expressed in normal esophageal epithelium and tumor cells of ESCC or EAC tissue specimens, as well as in non-neoplastic esophageal epithelial (Het-1A), ESCC (OE21, Kyse-270, Kyse-410), and EAC (OE33, SK-GT-4) cell lines. In vitro, HDAC activity, histone acetylation, and p21 expression were similarly affected in non-neoplastic, ESCC, and EAC cell lines post inhibitor treatment. Combined MS-275/AZA treatment, however, selectively targeted esophageal cancer cell lines by inducing DNA damage, cell viability loss, and apoptosis, and by decreasing cell migration. Non-neoplastic Het-1A cells were protected against HDACi (MS-275)/AZA treatment. RNA transcriptome analyses post MS-275 and/or AZA treatment identified novel regulated candidate genes (up: BCL6, Hes2; down: FAIM, MLKL), which were specifically associated with the treatment responses of esophageal cancer cells. In summary, combined HDACi/AZA treatment is efficient and selective for the targeting of esophageal cancer cells, despite similar target expression of normal and esophageal cancer epithelium, in vitro and in human esophageal carcinomas. The precise mechanisms of action of treatment responses involve novel candidate genes regulated by HDACi/AZA in esophageal cancer cells. Together, targeting of epigenetic modifiers in esophageal cancers may represent a potential future therapeutic approach.

Detailed analysis of epithelial-mesenchymal transition and tumor budding identifies predictors of long-term survival in pancreatic ductal adenocarcinoma.

BACKGROUND AND AIM: Pancreatic ductal adenocarcinoma (PDAC) is characterized by aggressive biology and poor prognosis even after resection. Long-term survival is very rare and cannot be reliably predicted. Experimental data suggest an important role of epithelial-mesenchymal transition (EMT) in invasion and metastasis of PDAC. Tumor budding is regarded as the morphological correlate of local invasion and cancer cell dissemination. The aim of this study was to evaluate the biological and prognostic implications of EMT and tumor budding in PDAC of the pancreatic head. METHODS: Patients were identified from a prospectively maintained database, and baseline, operative, histopathological, and follow-up data were extracted. Serial tissue slices stained for Pan-Cytokeratin served for analysis of tumor budding, and E-Cadherin, Beta-Catenin, and Vimentin staining for analysis of EMT. Baseline, operative, standard pathology, and immunohistochemical parameters were evaluated for prediction of long-term survival (≥ 30 months) in uni- and multivariate analysis. RESULTS: Intra- and intertumoral patterns of EMT marker expression and tumor budding provide evidence of partial EMT induction at the tumor-host interface. Lymph node ratio and E-Cadherin expression in tumor buds were independent predictors of long-term survival in multivariate analysis. CONCLUSIONS: Detailed immunohistochemical assessment confirms a relationship between EMT and tumor budding at the tumor-host interface. A small group of patients with favorable prognosis can be identified by combined assessment of lymph node ratio and EMT in tumor buds.

Double 90 Degrees Counterrotated End-to-End-Anastomosis: An Experimental Study of an Intestinal Anastomosis Technique.

AIM: The aim of the article is to investigate a new anastomotic technique compared with standardized intestinal anastomotic procedures. MATERIALS AND METHODS: A total of 32 male Wistar rats were randomized to three groups. In the Experimental Group (n = 10), the new double 90 degrees inversely rotated anastomosis was used, in the End Group (n = 10) a single-layer end-to-end anastomosis, and in the Side Group (n = 12) a single-layer side-to-side anastomosis. All anastomoses were done using interrupted sutures. On postoperative day 4, rats were relaparotomized. Bursting pressure, hydroxyproline concentration, a semiquantitative adhesion score and two histological anastomotic healing scores (mucosal healing according to Chiu and overall anastomotic healing according to Verhofstad) were collected. Most data are presented as median (range). p < 0.05 was considered significant. RESULTS: Anastomotic insufficiency occurred only in one rat of the Side Group. Median bursting pressure in the Experimental Group was 105 mm Hg (range = 72-161 mm Hg), significantly higher in the End Group (164 mm Hg; range = 99-210 mm Hg; p = 0.021) and lower in the Side Group by trend (81 mm Hg; range = 59-122 mm Hg; p = 0.093). Hydroxyproline concentration did not differ significantly in between the groups. The adhesion score was 2.5 (range = 1-3) in the Experimental Group, 2 (range = 1-2) in the End Group, but there were significantly more adhesions in the Side Group (range = 3-4); p = 0.020 versus Experimental Group, p < 0.001 versus End Group. The Chiu Score showed the worst mucosal healing in the Experimental Group. The overall Verhofstad Score was significantly worse (mean = 2.032; standard deviation [SD] = 0.842) p = 0.031 and p = 0.002 in the Experimental Group, compared with the Side Group (mean = 1.729; SD = 0.682) and the End Group (mean = 1.571; SD = 0.612). CONCLUSION: The new anastomotic technique is feasible and did not show any relevant complication. Even though it was superior to the side-to-side anastomosis by trend with respect to functional stability, mucosal healing surprisingly showed the worst results. Classical end-to-end anastomosis still seems to be the best choice regarding structural and functional anastomotic stability.

A prospective clinical study evaluating the development of bowel wall edema during laparoscopic and open visceral surgery.

BACKGROUND: To examine bowel wall edema development in laparoscopic and open major visceral surgery. METHODS: In a prospective study, 47 consecutively operated patients with gastric and pancreatic resections were included. Twenty-seven patients were operated in a conventional open procedure (open group) and 20 in a laparoscopic fashion (lap group). In all procedures, a small jejunal segment was resected during standard preparation, of which we measured the dry-wet ratio. Furthermore, HE staining was performed for measuring of bowel wall thickness and edema assessment. RESULTS: Mean value (±std) of dry-wet ratio was significantly lower in the open than in the lap group (0.169 ± 0.017 versus 0.179 ± 0.015; p = 0.03) with the same amount of fluid administration in both groups and a longer infusion interval during laparoscopic surgery. Subgroup analyses (only pancreatic resections) still showed similar results. Histologic examination depicted a significantly larger bowel wall thickness in the open group. CONCLUSIONS: Laparoscopic surgery does not seem to lead to the bowel wall edema observed to occur in open surgery regardless of the degree of intravenous fluid administration, thus supporting its use even in major visceral surgery.

Searching for the molecular benchmark of physiological intestinal anastomotic healing in rats: an experimental study.

PURPOSE: This investigation focuses on the physiological characteristics of gene transcription of intestinal tissue following anastomosis formation. METHODS: In eight rats, end-to-end ileo-ileal anastomoses were performed (n = 2/group). The healthy intestinal tissue resected for this operation was used as a control. On days 0, 2, 4 and 8, 10-mm perianastomotic segments were resected. Control and perianastomotic segments were examined with an Affymetrix microarray chip to assess changes in gene regulation. Microarray findings were validated using real-time PCR for selected genes. In addition to screening global gene expression, we identified genes intensely regulated during healing and also subjected our data sets to an overrepresentation analysis using the Gene Ontology (GO) and Kyoto Encyclopedia for Genes and Genomes (KEGG). RESULTS: Compared to the control group, we observed that the number of differentially regulated genes peaked on day 2 with a total of 2,238 genes, decreasing by day 4 to 1,687 genes and to 1,407 genes by day 8. PCR validation for matrix metalloproteinases-3 and -13 showed not only identical transcription patterns but also analogous regulation intensity. When setting the cutoff of upregulation at 10-fold to identify genes likely to be relevant, the total gene count was significantly lower with 55, 45 and 37 genes on days 2, 4 and 8, respectively. A total of 947 GO subcategories were significantly overrepresented during anastomotic healing. Furthermore, 23 overrepresented KEGG pathways were identified. CONCLUSION: This study is the first of its kind that focuses explicitly on gene transcription during intestinal anastomotic healing under standardized conditions. Our work sets a foundation for further studies toward a more profound understanding of the physiology of anastomotic healing.

Impact of routinely employed procedures for tissue processing on the proteomic analysis of formalin-fixed paraffin-embedded tissue.

PURPOSE: FFPE (formalin fixed, paraffin embedded) tissue cohorts represent an enduring archive of clinical specimens. Proteomic analysis of FFPE tissues is gaining interest for the in-depth analysis of aberrant proteome composition. Procedures for FFPE tissue processing are standardized but there is diversity regarding the different processing systems. This work focuses on three different processing methods commonly used in large European pathology institutes. EXPERIMENTAL DESIGN: Formalin fixed tissue specimens of different tumors were serially sliced and processed with three different processing systems (xylene, ethanol/vacuum or microwave based). After paraffin embedding, they were subjected to MS-based proteomic analysis to investigate the impact of tissue processing techniques on the quality of proteomic analysis. Results were compared with proteomic analysis of corresponding cryopreserved tissue specimens. RESULTS: All processing techniques achieved very good proteome coverage similar to the cryopreserved counterpart. Gene ontology profiles, relative protein abundances, and peptide modifications such as methionine oxidation or proteolytic truncation were highly similar for all techniques as well as for the cryopreserved samples. CONCLUSIONS AND CLINICAL RELEVANCE: The results show that different processing procedures do not impede proteomic analysis as a robust and powerful approach for the identification of protein determinants and markers of disease processes and highlights the general robustness of FFPE-tissue based proteomics.