Birte Kulemann

Epithelial cell guidance by self-generated EGF gradients

Cancer epithelial cells often migrate away from the primary tumor to invade into the surrounding tissues. Their migration is commonly assumed to be directed by pre-existent spatial gradients of chemokines and growth factors in the target tissues. Unexpectedly however, we found that the guided migration of epithelial cells is possible in vitro in the absence of pre-existent chemical gradients. We observed that both normal and cancer epithelial cells can migrate persistently and reach the exit along the shortest path from microscopic mazes filled with uniform concentrations of media. Using microscale engineering techniques and biophysical models, we uncovered a self-guidance strategy during which epithelial cells generate their own guiding cues under conditions of biochemical confinement. The self-guidance strategy depends on the balance between three interdependent processes: epidermal growth factor (EGF) uptake by the cells (U), the restricted transport of EGF through the structured microenvironment (T), and cell chemotaxis toward the resultant EGF gradients (C). The UTC self-guidance strategy can be perturbed by inhibition of signalling through EGF-receptors and appears to be independent from chemokine signalling. Better understanding of the UTC self-guidance strategy could eventually help devise new ways for modulating epithelial cell migration and delaying cancer cell invasion or accelerating wound healing.

Prognostic significance of Zinc finger E-box binding homeobox 1 (ZEB1) expression in cancer cells and cancer-associated fibroblasts in pancreatic head cancer

BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) is characterized by an aggressive biology and poor prognosis. Experimental evidence has suggested a role for the transcriptional repressor Zinc finger E-box binding homeobox 1 (ZEB1) in epithelial-mesenchymal transition, invasion, and metastasis in PDAC. ZEB1 expression has been observed in cancer cells as well as stromal fibroblasts. Our study aimed to evaluate the prognostic value of ZEB1 expression in PDAC tissue. METHODS Patient baseline and follow-up data were extracted from a prospectively maintained database. After clinicopathologic re-review, serial sliced tissue slides were immunostained for ZEB1, E-cadherin, vimentin, and pan-cytokeratin. ZEB1 expression in cancer cells and adjacent stromal fibroblasts was graded separately and correlated to routine histopathologic parameters and survival after resection. RESULTS A total of 117 cases of PDAC were included in the study. High ZEB1 expression in cancer cells and in stromal cancer-associated fibroblasts was associated with poor prognosis. There was also a trend for poor prognosis with a lymph node ratio of greater than 0.10. In line with its role as an inducer of epithelial-mesenchymal transition, ZEB1 expression in cancer cells was positively correlated with Vimentin expression and negatively with E-Cadherin expression. In multivariate analysis, stromal ZEB1 expression grade was the only independent factor of survival after resection. CONCLUSION Our data suggest that ZEB1 expression in cancer cells as well as in stromal fibroblasts are strong prognostic factors in PDAC. Stromal ZEB1 expression is identified for the first time as an independent predictor of survival after resection of PDAC. This observation suggests that therapies targeting ZEB1 and its downstream pathways could hit both cancer cells and supporting cancer-associated fibroblasts.

Intraoperative crystalloid overload leads to substantial inflammatory infiltration of intestinal anastomoses—a histomorphological analysis

BACKGROUND It has been shown that crystalloid fluid-overload promotes anastomotic instability. As physiologic anastomotic healing requires the sequential infiltration of different cells, we hypothesized this to be altered by liberal fluid regimes and performed a histomorphological analysis. METHODS 36 Wistar rats were randomized into 4 groups (n=8-10 rats/group) and treated with either liberal (+) or restrictive (-) perioperative crystalline (Jonosteril = Cry) or colloidal fluid (Voluven = Col). Anastomotic samples were obtained on postoperative day 4, routinely stained and histophathologically reviewed. Anastomotic healing was assessed using a semiquantitative score, assessing inflammatory cells, anastomotic repair and collagenase activity. RESULTS Overall, the crystalloid overload group (Cry (+)) showed the worst healing score (P < 0.01). A substantial increase of lymphocytes and macrophages was found in this group compared to the other three (P < 0.01). Both groups that received colloidal fluid (Col (+) and Col (-)) as well as the group that received restricted crystalloid fluid resuscitation (Cry (-)) had better intestinal healing. Collagenase activity was significantly higher in the Cry (+) group. CONCLUSION Intraoperative infusion of high-volume crystalloid fluid leads to a pathological anastomotic inflammatory response with a marked infiltration of leukocytes and macrophages resulting in accelerated collagenolysis.

Influence of Sleeve Gastrectomy on NASH and Type 2 Diabetes Mellitus

Background. Nonalcoholic fatty liver disease is present in up to 85% of adipose patients and may proceed to nonalcoholic steatohepatitis (NASH). With insulin resistance and obesity being the main risk factors for NASH, the effect of isolated sleeve gastrectomy (ISG) on these parameters was examined. Methods. 236 patients underwent ISG with intraoperative liver biopsy from December 2002 to September 2009. Besides demographic data, pre-operative weight/BMI, HbA1c, AST, ALT, triglycerides, HDL and LDL levels were determined. Results. A significant correlation of NASH with higher HbA1c, AST and ALT and lower levels for HDL was observed (P < .05, <.0001, <.0001, <.01, resp.). Overall BMI decreased from 45.0 ± 6.8 to 29.7 ± 6.5 and 31.6 ± 4.4 kg/m2 at 1 and 3 years. An impaired weight loss was demonstrated for patients with NASH and patients with elevated HbA1c (plateau 28.08 kg/m2 versus 29.79 kg/m2 and 32.30 kg/m2 versus 28.79 kg/m2, resp.). Regarding NASH, a significant improvement of AST, ALT, triglyceride and HDL levels was shown (P < .0001 for all). A resolution of elevated HbA1c was observed in 21 of 23 patients. Summary. NASH patients showed a significant loss of body weight and amelioration of NASH status. ISG can be successfully performed in these patients and should be recommended for this subgroup.

Limited resection for duodenal gastrointestinal stromal tumors: Surgical management and clinical outcome

AIM To analyze our experience in patients with duodenal gastrointestinal stromal tumors (GIST) and review the appropriate surgical approach. METHODS We retrospectively reviewed the medical records of all patients with duodenal GIST surgically treated at our medical institution between 2002 and 2011. Patient files, operative reports, radiological charts and pathology were analyzed. For surgical therapy open and laparoscopic wedge resections and segmental resections were performed for limited resection (LR). For extended resection pancreatoduodenectomy was performed. Age, gender, clinical symptoms of the tumor, anatomical localization, tumor size, mitotic count, type of resection resectional status, neoadjuvant therapy, adjuvant therapy, risk classification and follow-up details were investigated in this retrospective study. RESULTS Nine patients (5 males/4 females) with a median age of 58 years were surgically treated. The median follow-up period was 45 mo (range 6-111 mo). The initial symptom in 6 of 9 patients was gastrointestinal bleeding (67%). Tumors were found in all four parts of the duodenum, but were predominantly located in the first and second part of the duodenum with each 3 of 9 patients (33%). Two patients received neoadjuvant medical treatment with 400 mg imatinib per day for 12 wk before resection. In one patient, the GIST resection was done by pancreatoduodenectomy. The 8 LRs included a segmental resection of pars 4 of the duodenum, 5 wedge resections with primary closure and a wedge resection with luminal closure by Roux-Y duodeno-jejunostomy. One of these LRs was done minimally invasive; seven were done in open fashion. The median diameter of the tumors was 54 mm (14-110 mm). Using the Fletcher classification scheme, 3/9 (33%) tumors had high risk, 1/9 (11%) had intermediate risk, 4/9 (44%) had low risk, and 1/9 (11%) had very low risk for aggressive behaviour. Seven resections showed microscopically negative transsection margins (R0), two showed positive margins (R1). No patient developed local recurrence during follow-up. The one patient who underwent pancreatoduodenectomy died due to progressive disease with hepatic metastasis but without evidence of local recurrence. Another patient died in complete remission due to cardiac disease. Seven of the nine patients are alive disease-free. CONCLUSION In patients with duodenal GIST, limited surgical resection with microscopically negative margins, but also with microscopically positive margins, lead to very good local and systemic disease-free survival.

Multimodal Treatment of Locally Advanced Esophageal Adenocarcinoma: Which Regimen Should We Choose? Outcome Analysis of Perioperative Chemotherapy Versus Neoadjuvant Chemoradiation in 105 Patients

The study was done to compare treatment and long‐term outcomes of neoadjuvant chemoradiation (neoCRT) and perioperative chemotherapy (periCTX) in patients with surgically treated esophageal adenocarcinoma.

Sonic Hedgehog in pancreatic cancer: From bench to bedside, then back to the bench

Developmental genes are known to regulate cell proliferation, migration, and differentiation; thus, it comes as no surprise that the misregulation of developmental genes plays an important role in the biology of human cancers. One such pathway that has received an increasing amount of attention for its function in carcinogenesis is the Hedgehog (Hh) pathway. Initially the domain of developmental biologists, the Hh pathway and one of its ligands, Sonic Hedgehog (Shh), have been shown to play an important role in body planning and organ development, particularly in the foregut endoderm. Their importance in human disease became known to cancer biologists when germline mutations that resulted in the unregulated activity of the Hh pathway were found to cause basal cell carcinoma and medulloblastoma. Since then, misexpression of the Hh pathway has been shown to play an important role in many other cancers, including those of the pancreas. In many institutions, investigators are targeting misexpression of the Hh pathway in clinical trials, but there is still much fundamental knowledge to be gained about this pathway that can shape its clinical utility. This review will outline the evolution of our understanding of this pathway as it relates to the pancreas, as well as how the Hh pathway came to be a high-priority target for treatment.

Impact of remote ischemic preconditioning on wound healing in small bowel anastomoses

AIM To investigate the influence of remote ischemic preconditioning (RIPC) on anastomotic integrity. METHODS Sixty male Wistar rats were randomized to six groups. The control group (n = 10) had an end-to-end ileal anastomosis without RIPC. The preconditioned groups (n = 34) varied in time of ischemia and time of reperfusion. One group received the amino acid L-arginine before constructing the anastomosis (n = 9). On postoperative day 4, the rats were re-laparotomized, and bursting pressure, hydroxyproline concentration, intra-abdominal adhesions, and a histological score concerning the mucosal ischemic injury were collected. The data are given as median (range). RESULTS On postoperative day 4, median bursting pressure was 124 mmHg (60-146 mmHg) in the control group. The experimental groups did not show a statistically significant difference (P > 0.05). Regarding the hydroxyproline concentration, we did not find any significant variation in the experimental groups. We detected significantly less mucosal injury in the RIPC groups. Furthermore, we assessed more extensive intra-abdominal adhesions in the preconditioned groups than in the control group. CONCLUSION RIPC directly before performing small bowel anastomosis does not affect anastomotic stability in the early period, as seen in ischemic preconditioning.

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

Abstract 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.

Laparoscopic extirpation of a fork from the duodenum

BackgroundA 23-year-old woman who 2 weeks before visiting our institution swallowed a plastic fork while attempting to induce vomiting during a party presented with progressive abdominal pain. Various techniques for removing foreign bodies from the intestinal tract have been described. We present the laparoscopic retrieval of a 15-cm fork from the duodenal bulb.MethodsThe patient presented with leukocytosis and epigastric tenderness. An upper endoscopy revealed a plastic fork, tines up, perforating the duodenal bulb. The handle was irremovably lodged in the opposite part of the duodenum. Perforating objects and objects larger than 7 cm ought to be removed surgically to prevent esophageal perforation. The patient was placed in supine position with the surgeon standing between her legs. Four trocars, two 10-mm and two 5-mm, were used. We saw a slight swelling of the duodenum with few fibrin stripes and roughly 250 ml of white exudate. The fork tines were visible; there were no injuries to the liver. The tines were held with a clamp while the perforated intestinal wall was carefully dissected with a monopolar hug and later with an ACE harmonic scalpel due to bleeding. The fork was extracted in the proximal direction through the perforation injury. There was no severe necrosis and debridement was not necessary. The bowel was irrigated and continuously sutured with 3-0 PDS. Finally, the fork was retrieved through the 10-mm trocar incision.ResultsOperating time was 60 min and blood loss was roughly 100 ml. The patient’s postoperative course was uneventful. One year after intervention, the patient is doing well.ConclusionA fork may be swallowed, but usually does not spontaneously pass through the gastrointestinal tract. Early removal should be advised to avoid perforation and to minimize morbidity. Laparoscopic removal is a safe and feasible method of managing foreign bodies that are not removable endoscopically.