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Dive into the research topics where Robin Wachowiak is active.

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Featured researches published by Robin Wachowiak.


Modern Pathology | 2007

L1 is associated with micrometastatic spread and poor outcome in colorectal cancer

Jussuf T. Kaifi; Uta Reichelt; Alexander Quaas; Paulus G. Schurr; Robin Wachowiak; Emre F. Yekebas; Tim Strate; Claus Schneider; Klaus Pantel; Melitta Schachner; Guido Sauter; Jakob R. Izbicki

L1 is a cell adhesion molecule expressed at the invasive front of colorectal tumors with an important role in metastasis. The aim of the present study was to determine L1 protein expression in a large cohort of colorectal cancer patients and its impact on early metastatic spread and survival. A total of 375 patients that underwent surgical treatment for colorectal cancer were chosen retrospectively. A tissue microarray was constructed of 576 tissue samples from these patients and analyzed by immunohistochemistry with a monoclonal antibody against human L1 (UJ127). Lymph node and bone marrow micrometastasis were assessed with monoclonal antibodies Ber-EP4 and pancytokeratin A45-B/B3, respectively. Associations between L1 expression and lymph node, bone marrow micrometastasis and survival were investigated with Fishers, log-rank test and Cox multivariate analysis. All statistical tests were two-sided. L1 was detected in a subset of 48 (13%) of 375 patients examined. Analysis of L1 expression and survival revealed a significantly worse outcome for L1-positive patients by log-rank test (P<0.05). Multivariate Cox regression analysis showed the strongest independent prognostic impact of L1 expression (P<0.05). Fishers test revealed a significant association of L1 expression and presence of disseminated tumor cells in lymph nodes and bone marrow (P<0.05). L1 is a powerful prognostic marker for patients that undergo complete surgical resection. It may have a role in early metastatic spread, as L1 is associated with micrometastases to both the lymph nodes and bone marrow. Thus, L1 should be explored further as a target for adjuvant therapy for micrometastatic disease.


Modern Pathology | 2006

L1 (CD171) is highly expressed in gastrointestinal stromal tumors

Jussuf T. Kaifi; Andrea Strelow; Paulus G. Schurr; Uta Reichelt; Emre F. Yekebas; Robin Wachowiak; Alexander Quaas; Tim Strate; Hansjoerg Schaefer; Guido Sauter; Melitta Schachner; Jakob R. Izbicki

The treatment strategy for mesenchymal tumors of the gastrointestinal tract is based upon typing of the tumor. Especially differential diagnosis of gastrointestinal stromal tumors (GISTs) to leiomyomas is crucial for determining radicality of surgery. L1 cell adhesion molecule (CD171) plays an essential role in tumor progression. The aim of this study was to determine expression of L1 in GISTs, smooth muscle tumors, desmoid-type fibromatosis and peripheral nerve sheath tumors (PNSTs). We retrospectively analyzed a total of 129 surgically resected primary tumors or metastases of 72 GISTs, 29 smooth muscle tumors, seven PNSTs and 21 desmoid-type fibromatosis by immunohistochemistry for c-kit, CD34, smooth muscle actin, desmin, vimentin, S-100 and L1 expression. L1 expression was detected in 53 (74%) of 72 GISTs but in none of 29 smooth muscle tumors or 21 desmoid-type fibromatosis (P<0.01 by Fishers test). In all, four (57%) of seven peripheral nerve sheath tumors were L1-positive. Survival analysis of 55 surgically completely resected GISTs presenting without metastasis at initial diagnosis revealed no tumor-specific death among L1-negative patients (P=0.13 by log-rank test; median follow-up time 41 months) and one recurrence was observed (P=0.12). Interestingly high levels of L1 were seen in tumor vascular endothelial cells of smooth muscle tumors and PNSTs, but not in GISTs. Our data show that L1 is highly expressed in GISTs but not in smooth muscle tumors and desmoid-type fibromatosis being important differential diagnoses. The trend towards a reduced survival of L1-positive patients in this study has to be further evaluated in future trials with higher patient numbers.


Annals of Surgical Oncology | 2007

Prognostic Implications of Netrin-1 Expression and Its Receptors in Patients with Adenocarcinoma of the Pancreas

Björn-Christian Link; Uta Reichelt; Matthias Schreiber; Jussuf T. Kaifi; Robin Wachowiak; Dean Bogoevski; Michael Bubenheim; Guel Cataldegirmen; Karim A. Gawad; Rana Issa; Susann Koops; Jakob R. Izbicki; Emre F. Yekebas

BackgroundTo assess the interaction between the expression of netrin-1 or of its receptors to the prognosis of ductal adenocarcinoma of the pancreas.MethodsIn 82 patients with resectable pancreatic adenocarcinoma who underwent curative operation, the expression patterns of netrin-1, deleted in colorectal carcinomas (DCC), UNC5H3, and neogenin were determined by immunohistochemical staining. Kaplan-Meier analysis was performed to assess the prognostic relevance of the examined expression patterns.ResultsMedian follow-up was 15 ± 19.9 months (range, 4–108 months). Patients suffering from tumors with no or little expression of netrin-1 (n = 67) had a median recurrence-free survival of 10 months (95% CI, 7–13 months), while a middle to strong expression (n = 15) was associated with a significantly worse median recurrence-free survival of only four months (95% CI, three to five months, p = 0.0165). Overall and recurrence-free survival showed no significant differences between the different expression patterns of DCC, UNC5H3 or neogenin. Netrin-1 expression had significant impact (p = 0.001) on overall survival of patients suffering from poorly differentiated tumors. Stratification according to the nodal status revealed significant influence (p = 0.007) of UNC5H3 expression on the overall survival of patients with pN1 status.ConclusionExpression of netrin-1 has significant impact on time to tumor relapse in adenocarcinoma of the pancreas. Netrin-1 expression is associated with worse outcome in poorly differentiated pancreatic adenocarcinomas. Risk-stratification according to the UNC5H3 receptor expression pattern shows that node positive patients (pN1) with no to little UNC5H3 expression carry a significantly worse prognosis than those with middle to strong UNC5H3 expression.


Seminars in Pediatric Surgery | 2011

Embryology of the early foregut

Roman Metzger; Robin Wachowiak; Dietrich Kluth

In embryology, no agreement exists how the early foregut differentiates into the respiratory tract and the intestinal tract. In particular, the formation of the early lung anlage as well as the process of separation of trachea and esophagus remains unclear. This process is explained in a rather schematic way and aims more to explain pathologic findings, whereas true embryologic investigations are extremely rare in this field. Here, scanning electron microscopy of the normal foregut development illustrates the steps, which finally leads to the development of larynx and trachea on the one hand, and pharynx and esophagus on the other hand. This study was performed in chicken embryos in accordance to the developmental stages described. As the main results from these illustrations show, we found no evidence for lateral foregut ridges inside the undivided foregut chamber and no fusion of lateral foregut components to form a trachea-esophageal septum.


Clinical Cancer Research | 2006

Microsatellite DNA alterations of gastrointestinal stromal tumors are predictive for outcome

Paulus G. Schurr; Stefan Wolter; Jussuf T. Kaifi; Uta Reichelt; Helge Kleinhans; Robin Wachowiak; Emre F. Yekebas; Tim Strate; Viacheslav Kalinin; Ronald Simon; Guido Sauter; Hansjoerg Schaefer; Jakob R. Izbicki

Purpose: In gastrointestinal stromal tumors (GIST), loss of heterozygosity (LOH) on chromosome 22 and its presumptive biological function has been described. The prognostic value of these and other DNA regions for patient survival remains unclear. Experimental Design: Sixty patients who underwent surgery at our institution between 1992 and 2003 for GIST were histopathologically reclassified by immunohistochemistry and the GIST consensus group criteria 2001. Twenty-one microsatellite loci on chromosomes 3, 9, 13, 17, 18, and 22 were screened for alterations in tumor and healthy DNA. Survival was calculated by Kaplan-Meier plots. Results: Eleven (18.3%) of 60 patients showed metastases at presentation. Thirteen (21.7%) of 60 were high-risk GISTs. LOH was found in all tumors. Twenty-eight (46.7%) of 60 showed more than two LOH in 21 microsatellite marker sites. The frequency of single marker LOH varied from 1.7% to 28.3% among tumors. Frequent LOH was found on chromosomes 22 and 17. The correlation of LOH positivity and the consensus scoring was significant (P = 0.005, χ2 test). After a median observation time of 33.3 months (95% confidence interval, 23.9-42.6), overall survival was best for patients with tumors of very low, low, and intermediate risks with only 6 of 36 death events, whereas 14 of 24 high-risk and metastasized patients had died (P < 0.001, log-rank test). Likewise, LOH significantly predicted survival (P = 0.013) and the effect was particularly detrimental for LOH on chromosome 17 (P < 0.001). Conclusions: LOH is a useful phenomenon for the prognosis of GIST. Rather than chromosome 22 markers, chromosome 17 markers independently predict survival.


European Journal of Pediatric Surgery | 2013

The Foker Technique (FT) and Kimura Advancement (KA) for the Treatment of Children with Long-Gap Esophageal Atresia (LGEA): Lessons Learned at Two European Centers

Mariusz Sroka; Robin Wachowiak; Marcin Losin; Agnieszka Szlagatys-Sidorkiewicz; Piotr Landowski; Piotr Czauderna; John E. Foker; Holger Till

INTRODUCTION We present the experiences from two European centers performing the Foker technique (FT) of esophageal lengthening by axial traction and the Kimura advancement (KA) method of lengthening the upper pouch by extrathoracic resiting a spit fistula (SF) in children with long-gap esophageal atresia (LGEA, gap length > 5 cm). MATERIALS AND METHODS A total of 15 children were treated (8 pure EA, 6 lower tracheoesophageal fistula [TEF], and 1 upper TEF). Gaps ranged from 5 to 14 cm. Nine children already had a SF. Patients were grouped according to the presence of a SF and the subsequent surgical strategy: Group A (no SF, n = 6) received FT on both pouches. Group B (with SF, n = 6) received KA of SF and FT of the lower pouch. Group C (with SF, n = 3) received closure of the SF and subsequent Foker traction (CSFT) on both pouches. RESULTS Group A: Primary repairs for all six children (mean age 3 months, gap length 6.5 cm) after a mean traction time of 3 weeks and a mean of 2.1 thoracotomies (range 2 to 3). Dilations were required in three out of six for anastomotic strictures with one perforation during the second dilation. Group B: All six children (mean age 16.4 months, gap length 9.5 cm) had a primary anastomosis, although for two it was significantly delayed (48 and 143 weeks traction time) because of infections. The number of thoracotomies ranged from 2 to 8 (mean 3.6). Leaks occurred in five out of six anastomoses (responsive to conservative management). Two children developed severe strictures, which required the anastomosis to be redone. In group C (mean age 10.6 months, gap length 6.5 cm), several major complications occurred. The three SF closures leaked (one iatrogenic) causing severe mediastinitis. CSFT was successful in only one case and the other two children had an esophageal replacement (stomach, jejunum). No deaths occurred in the series. CONCLUSION FT of both pouches (group A) resulted in primary repairs of all six LGEA patients. The combination of KA and FT (group B) resulted in an equivalent rate of primary repairs, but with an increased number of thoracotomies and rate of complications compared with group A. CSFT (group C) resulted in a high failure rate. More data are needed (we propose a multicenter registry) to elucidate the safety and efficacy of each elongation technique and to establish an algorithm with clearer inclusion and exclusion criteria.


Pediatric Surgery International | 2008

Universal expression of cell adhesion molecule NCAM in neuroblastoma in contrast to L1: implications for different roles in tumor biology of neuroblastoma?

Robin Wachowiak; Tamina Rawnaq; Roman Metzger; Alexander Quaas; Henning C. Fiegel; Nils Kähler; Udo Rolle; Jakob R. Izbicki; Jussuf T. Kaifi; Holger Till

PurposeNeuroblastoma is a biological, genetic and morphological heterogeneous tumor with a variable clinical course. NCAM is a cell adhesion molecule belonging to the immunoglobulin superfamily with structural similarities to cell adhesion molecule L1. The aim of this study was to determine the expression of NCAM in neuroblastoma and to compare the results to the findings of a previous study which examined L1 expression in the same group of patients.Materials and methodsNCAM expression was investigated on a tissue array with 66 surgically resected neuroblastoma samples by immunohistochemistry with a monoclonal antibody clone 1B6 and peroxidase method.ResultsStrong expression of NCAM was detected in all of the 66 (100%) neuroblastoma tumors in contrast to L1 which was not expressed in all tumors.ConclusionIn contrast to L1, which was found to predict favorable outcome, NCAM is universally expressed in neuroblastoma. Therefore NCAM represents a marker for neuroblastomas irrespectively of their stages whereas L1 as an indicator for developing neuronal cells seems to identify more mature stages of this tumor. The high grade of NCAM expression might present a prerequisite for establishment of antibody-based therapies.


Journal of Laparoendoscopic & Advanced Surgical Techniques | 2011

Single-incision multiport laparoscopy does not cause more pain than conventional laparoscopy: a prospective evaluation in children undergoing appendectomy.

Steffi Mayer; Antje Werner; Robin Wachowiak; Ulf Buehligen; Roland Boehm; Christian Geyer; Holger Till

BACKGROUND The benefit of single-incision multiport laparoscopy (SIMPL) remains a matter of vivid discussion. For good reason it has been speculated that SIMPL causes more postoperative pain, because a minilaparotomy is required to place the multiport system. We prospectively evaluated postoperative pain scores and requirement of analgesic medication following conventional laparoscopic (CL) versus SIMPL appendectomy in children. METHODS The access for laparoscopic appendectomy was decided upon the surgeons preference. Between April and October 2010, individual abdominal pain scores at 8, 16, 24, 48, and 72 hours postoperatively as well as the incidence of umbilical or shoulder pain and the total amount of peri- and postoperative analgesics, operative time, length of hospital stay, and demographics were assessed. Analgesics (paracetamol and/or metamizole, 15 mg/kg body weight) were administered regularly or on inquiry of the patient. Data are presented as means±standard deviation tested at a significance level of P<.05. RESULTS All operations were laparoscopically completed without conversion or addition of extra ports. Thirty-nine patients (8 SIMPL appendectomy) at a mean age of 12.3±2.4 years and a mean body mass index of 19.16±3.2 kg/m(2) were included. Equal operation times were observed (SIMPL: 68.5±19.9 minutes versus CL: 66.2±19.5 minutes). There were no significant differences for the individual pain scores or the incidence of umbilical and shoulder pain between study groups. The total amount of required analgesic medication was significantly lower after SIMPL appendectomy (SIMPL: 65.73±43.8 mg/kg versus CL: 106.39±46.4 mg/kg, P=.04). CONCLUSION In summary, the present study substantiates the evidence that SIMPL appendectomy in children and adolescents is not only feasible but also beneficial for the patient without translation into increased postoperative pain. Presently, we are conducting a randomized, blinded study to validate these findings.


Pediatric Surgery International | 2008

Midkine is highly expressed in neuroblastoma tissues

Henning C. Fiegel; Jussuf T. Kaifi; Robin Wachowiak; Alexander Quaas; Kuniaki Aridome; Keiko Ichihara-Tanaka; Takashi Muramatsu; Roman Metzger; Jakob R. Izbicki; Rudolf Erttmann; Dietrich Kluth; Holger Till

PurposeNeuroblastoma (NBL) is a tumor from neural crest cells, and is the most frequent solid tumor in children. Midkine (MK) is a pleiotropin analogon, which is frequently expressed in neuronal and epithelial tumors and is a marker for a poor clinical outcome. The aims of this study were to assess MK expression in NBL and investigate the correlation with clinical outcome.MethodsFifty-six specimens of NBL were stained for MK on a tissue microarray by immunohistochemistry (IHC). Fresh frozen tumor tissues were used for RNA isolation, and RT-PCR analysis for MK-mRNA expression was performed. Survival data, risk factors and disease stages were correlated with MK status assessed by IHC and RT-PCR analysis.ResultsMK-mRNA expression was found in the majority of the tumor tissues (75%), whereas MK protein could be detected only in 46% of the NBL by IHC. No correlation of MK status with survival, risk factors or disease stage was observed.ConclusionA majority of NBL express MK-mRNA, whereas not all MK mRNA positive tumors showed also a positive MK IHC staining. The high expression of MK-mRNA expression might present a promising target for new adenovirus-based gene therapeutic approaches for the treatment of NBL.


Journal of Laparoendoscopic & Advanced Surgical Techniques | 2008

Cardia Yield Pressure Measurement in an Infant Porcine Model: A Novel Technique to Evaluate the Quality of Laparoscopic Fundoplication

Robin Wachowiak; Alexandra Krauss; Bernd Donaubauer; Oliver J. Muensterer

BACKGROUND Cardia yield pressure (CYP) has been described as a measure of the combined effect of all antireflux mechanisms and not simply as another test of lower esophageal sphincter pressure. In this paper, we present a simple technique for the measurement of CYP before and after fundoplication through laparoscopic gastrostomy in an experimental pig model. MATERIALS AND METHODS Twelve 8-week-old female pigs with a mean weight of 8.7 +/- 0.7 kg underwent laparoscopic gastrostomy placement and Nissen fundoplication under general anesthesia. CYP was determined before and after the fundoplication by filling the stomach with water until reaching the pressure at which the cardia opened and became incompetent. Pre- and postoperative CYP was compared by using the Students t-test for paired samples. RESULTS Laparoscopic Nissen fundoplication and gastrostomy was completed in all pigs. CYP increased in all subjects after fundoplication, from a mean of 20 +/- 8 to a mean of 63 +/- 13 cm of H(2)O (p < 0.001). The lowest increase in yield pressure of 17.5 cm was recorded after the first operation. Work-flow analysis revealed that this particular procedure took the longest, that bleeding from the liver was encountered, and shorter sutures than those used on all subsequent fundoplications may have compromised knot tying. CONCLUSIONS CYP increases consistently after laparoscopic Nissen Fundoplication in young pigs. This parameter may be a good indicator of antireflux efficacy and functional quality of the result. Yield pressure measured through laparoscopic gastrostomy offers a new, feasible, and effective technique for the evaluation of antireflux surgery in an experimental setting. Moreover, this minimally invasive technique may become a simple investigative tool for other antireflux procedures.

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Jussuf T. Kaifi

Pennsylvania State University

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Holger Till

Medical University of Graz

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