@article{HankirRotzingerNordbecketal.2021, author = {Hankir, Mohammed K. and Rotzinger, Laura and Nordbeck, Arno and Corteville, Caroline and Dischinger, Ulrich and Knop, Juna-Lisa and Hoffmann, Annett and Otto, Christoph and Seyfried, Florian}, title = {Leptin receptors are not required for Roux-en-Y gastric bypass surgery to normalize energy and glucose homeostasis in rats}, series = {Nutrients}, volume = {13}, journal = {Nutrients}, number = {5}, issn = {2072-6643}, doi = {10.3390/nu13051544}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239550}, year = {2021}, abstract = {Sensitization to the adipokine leptin is a promising therapeutic strategy against obesity and its comorbidities and has been proposed to contribute to the lasting metabolic benefits of Roux-en-Y gastric bypass (RYGB) surgery. We formally tested this idea using Zucker fatty fa/fa rats as an established genetic model of obesity, glucose intolerance, and fatty liver due to leptin receptor deficiency. We show that the changes in body weight in these rats following RYGB largely overlaps with that of diet-induced obese Wistar rats with intact leptin receptors. Further, food intake and oral glucose tolerance were normalized in RYGB-treated Zucker fatty fa/fa rats to the levels of lean Zucker fatty fa/+ controls, in association with increased glucagon-like peptide 1 (GLP-1) and insulin release. In contrast, while fatty liver was also normalized in RYGB-treated Zucker fatty fa/fa rats, their circulating levels of the liver enzyme alanine aminotransferase (ALT) remained elevated at the level of obese Zucker fatty fa/fa controls. These findings suggest that the leptin system is not required for the normalization of energy and glucose homeostasis associated with RYGB, but that its potential contribution to the improvements in liver health postoperatively merits further investigation.}, language = {en} } @article{BoelchGurokGilbertetal.2021, author = {Boelch, Sebastian P. and Gurok, Anna and Gilbert, Fabian and Weißenberger, Manuel and Rudert, Maximilian and Barthel, Thomas and Reppenhagen, Stephan}, title = {Why compromise the patella? Five-year follow-up results of medial patellofemoral ligament reconstruction with soft tissue patellar fixation}, series = {International Orthopaedics}, volume = {45}, journal = {International Orthopaedics}, issn = {0341-2695}, doi = {10.1007/s00264-020-04922-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235751}, pages = {1493-1500}, year = {2021}, abstract = {Purpose This study investigates the redislocation rate and functional outcome at a minimum follow-up of five years after medial patellofemoral ligament (MPFL) reconstruction with soft tissue patellar fixation for patella instability. Methods Patients were retrospectively identified and knees were evaluated for trochlea dysplasia according to Dejour, for presence of patella alta and for presence of cartilage lesion at surgery. At a minimum follow-up of five years, information about an incident of redislocation was obtained. Kujala, Lysholm, and Tegner questionnaires as well as range of motion were used to measure functional outcome. Results Eighty-nine knees were included. Follow-up rate for redislocation was 79.8\% and for functional outcome 58.4\%. After a mean follow-up of 5.8 years, the redislocation rate was 5.6\%. There was significant improvement of the Kujala score (68.8 to 88.2, p = 0.000) and of the Lysholm score (71.3 to 88.4, p = 0.000). Range of motion at follow-up was 149.0° (115-165). 77.5\% of the knees had patella alta and 52.9\% trochlear dysplasia types B, C, or D. Patellar cartilage legions were present in 54.2\%. Redislocations occurred in knees with trochlear dysplasia type C in combination with patella alta. Conclusion MPFL reconstruction with soft tissue patellar fixation leads to significant improvement of knee function and low midterm redislocation rate. Patients with high-grade trochlear dysplasia should be considered for additional osseous correction.}, language = {en} } @article{KastnerHendricksDeinleinetal.2021, author = {Kastner, Carolin and Hendricks, Anne and Deinlein, Hanna and Hankir, Mohammed and Germer, Christoph-Thomas and Schmidt, Stefanie and Wiegering, Armin}, title = {Organoid Models for Cancer Research — From Bed to Bench Side and Back}, series = {Cancers}, volume = {13}, journal = {Cancers}, number = {19}, issn = {2072-6694}, doi = {10.3390/cancers13194812}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246307}, year = {2021}, abstract = {Simple Summary Despite significant strides in multimodal therapy, cancers still rank within the first three causes of death especially in industrial nations. A lack of individualized approaches and accurate preclinical models are amongst the major barriers that limit the development of novel therapeutic options and drugs. Recently, the 3D culture system of organoids was developed which stably retains the genetic and phenotypic characteristics of the original tissue, healthy as well as diseased. In this review, we summarize current data and evidence on the relevance and reliability of such organoid culture systems in cancer research, focusing on their role in drug investigations (in a personalized manner). Abstract Organoids are a new 3D ex vivo culture system that have been applied in various fields of biomedical research. First isolated from the murine small intestine, they have since been established from a wide range of organs and tissues, both in healthy and diseased states. Organoids genetically, functionally and phenotypically retain the characteristics of their tissue of origin even after multiple passages, making them a valuable tool in studying various physiologic and pathophysiologic processes. The finding that organoids can also be established from tumor tissue or can be engineered to recapitulate tumor tissue has dramatically increased their use in cancer research. In this review, we discuss the potential of organoids to close the gap between preclinical in vitro and in vivo models as well as clinical trials in cancer research focusing on drug investigation and development.}, language = {en} } @article{MeirMaurusKuperetal.2021, author = {Meir, Michael and Maurus, Katja and Kuper, Jochen and Hankir, Mohammed and Wardelmann, Eva and Rosenwald, Andreas and Germer, Christoph-Thomas and Wiegering, Armin}, title = {The novel KIT exon 11 germline mutation K558N is associated with gastrointestinal stromal tumor, mastocytosis, and seminoma development}, series = {Genes, Chromosomes \& Cancer}, volume = {60}, journal = {Genes, Chromosomes \& Cancer}, number = {12}, doi = {10.1002/gcc.22988}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257476}, pages = {827-832}, year = {2021}, abstract = {Familial gastrointestinal stromal tumors (GIST) are dominant genetic disorders that are caused by germline mutations of the type III receptor tyrosine kinase KIT. While sporadic mutations are frequently found in mastocytosis and GISTs, germline mutations of KIT have only been described in 39 families until now. We detected a novel germline mutation of KIT in exon 11 (p.Lys-558-Asn; K558N) in a patient from a kindred with several GISTs harboring different secondary somatic KIT mutations. Structural analysis suggests that the primary germline mutation alone is not sufficient to release the autoinhibitory region of KIT located in the transmembrane domain. Instead, the KIT kinase module becomes constitutively activated when K558N combines with different secondary somatic mutations. The identical germline mutation in combination with an additional somatic KIT mutation was detected in a second patient of the kindred with seminoma while a third patient within the family had a cutaneous mastocytosis. These findings suggest that the K558N mutation interferes with the juxtamembranous part of KIT, since seminoma and mastocystosis are usually not associated with exon 11 mutations.}, language = {en} } @article{PlassmeierHankirSeyfried2021, author = {Plassmeier, Lars and Hankir, Mohammed K. and Seyfried, Florian}, title = {Impact of Excess Body Weight on Postsurgical Complications}, series = {Visceral Medicine}, volume = {37}, journal = {Visceral Medicine}, number = {4}, issn = {2297-4725}, doi = {10.1159/000517345}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244890}, pages = {287-97}, year = {2021}, abstract = {Background: Obesity is considered a risk factor for postoperative complications as it can limit exposure to the operation field, thereby significantly prolonging surgery time. Obesity-associated comorbidities, such as low-grade systemic inflammation, impaired functional status, and type 2 diabetes, are independent risk factors for impaired anastomotic wound healing and nonsurgical site infections. If obesity itself is an independent risk factor for surgical complications remains controversial, but the reason for this is largely unexplored. Summary: A MEDLINE literature search was performed using the terms: "obesity," "excess body weight," and "surgical complications." Out of 65,493 articles 432 meta-analyses were screened, of which 25 meta-analyses were on the subject. The vast majority of complex oncologic procedures in the field of visceral surgery have shown higher complication rates in obese patients. Meta-analyses from the last 10 to 15 years with high numbers of patients enrolled consistently have shown longer operation times, higher blood loss, longer hospital stay for colorectal procedures, oncologic upper gastrointestinal (GI) procedures, and pancreatic surgery. Interestingly, these negative effects seem not to affect the overall survival in oncologic patients, especially in esophageal resections. A selection bias in oncologic upper GI patients may have influenced the results with higher BMI in upper GI cancer to be a predictor for better nutritional and performance status. Key Messages: Contrary to bariatric surgery, only limited evidence indicated that site and type of surgery, the approach to the abdominal cavity (laparoscopic vs. open), institutional factors, and the type of perioperative care such as ERAS protocols may play a role in determining postsurgical complications in obese patients. The initial question remains therefore partially unanswered. Large nationwide register-based studies are necessary to better understand which aspects of obesity and its related comorbidities define it as a risk factor for surgical complications.}, language = {en} } @article{BrandReimerReibetanzetal.2021, author = {Brand, Markus and Reimer, Stanislaus and Reibetanz, Joachim and Flemming, Sven and Kornmann, Marko and Meining, Alexander}, title = {Endoscopic full thickness resection vs. transanal endoscopic microsurgery for local treatment of rectal neuroendocrine tumors - a retrospective analysis}, series = {International Journal of Colorectal Disease}, volume = {36}, journal = {International Journal of Colorectal Disease}, issn = {0179-1958}, doi = {10.1007/s00384-020-03800-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234833}, pages = {971-976}, year = {2021}, abstract = {Purpose Local treatment of small well-differentiated rectal neuroendocrine tumors (NETs) is recommended by current guidelines. However, although several endoscopic methods have been established, the highest R0 rate is achieved by transanal endoscopic microsurgery (TEM). Since a recently published study about endoscopic full thickness resection (eFTR) showed a R0 resection rate of 100\%, the aim of this study was to evaluate both methods (eFTR vs. TEM). Methods We retrospectively analyzed all patients with rectal NET treated either by TEM (1999-2018) or eFTR (2016-2019) in two tertiary centers (University Hospital Wuerzburg and Ulm). We analyzed clinical, procedural, and histopathological outcomes in both groups. Results Twenty-eight patients with rectal NET received local treatment (TEM: 13; eFTR: 15). Most tumors were at stage T1a and grade G1 or G2 (in the TEM group two G3 NETs were staged T2 after neoadjuvant chemotherapy). In both groups, similar outcomes for en bloc resection rate, R0 resection rate, tumor size, or specimen size were found. No procedural adverse events were noted. Mean procedure time in the TEM group was 48.9 min and 19.2 min in the eFTR group. Conclusion eFTR is a convincing method for local treatment of small rectal NETs combining high safety and efficacy with short interventional time.}, language = {en} } @article{BaurRamserKelleretal.2021, author = {Baur, Johannes and Ramser, Michaela and Keller, Nicola and Muysoms, Filip and D{\"o}rfer, J{\"o}rg and Wiegering, Armin and Eisner, Lukas and Dietz, Ulrich A.}, title = {Robotic hernia repair II. English version}, series = {Der Chirurg}, volume = {92}, journal = {Der Chirurg}, number = {Suppl 1}, doi = {10.1007/s00104-021-01479-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323866}, pages = {S15-S26}, year = {2021}, abstract = {Endoscopic management of umbilical and incisional hernias has adapted to the limitations of conventional laparoscopic instruments over the past 30 years. This includes the development of meshes for intraperitoneal placement (intraperitoneal onlay mesh, IPOM), with antiadhesive coatings; however, adhesions do occur in a significant proportion of these patients. Minimally invasive procedures result in fewer perioperative complications, but with a slightly higher recurrence rate. With the ergonomic resources of robotics, which offers angled instruments, it is now possible to implant meshes in a minimally invasively manner in different abdominal wall layers while achieving morphologic and functional reconstruction of the abdominal wall. This video article presents the treatment of ventral and incisional hernias with mesh implantation into the preperitoneal space (robot-assisted transabdominal preperitoneal ventral hernia repair, r‑ventral TAPP) as well as into the retrorectus space (r-Rives and robotic transabdominal retromuscular umbilical prosthetic repair, r‑TARUP, respectively). The results of a cohort study of 118 consecutive patients are presented and discussed with regard to the added value of the robotic technique in extraperitoneal mesh implantation and in the training of residents.}, language = {en} } @article{RamserBaurKelleretal.2021, author = {Ramser, Michaela and Baur, Johannes and Keller, Nicola and Kukleta, Jan F. and D{\"o}rfer, J{\"o}rg and Wiegering, Armin and Eisner, Lukas and Dietz, Ulrich A.}, title = {Robotic hernia surgery I. English version}, series = {Der Chirurg}, volume = {92}, journal = {Der Chirurg}, number = {Suppl 1}, doi = {10.1007/s00104-021-01446-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323934}, pages = {S1-S13}, year = {2021}, abstract = {The treatment of inguinal hernias with open and minimally invasive procedures has reached a high standard in terms of outcome over the past 30 years. However, there is still need for further improvement, mainly in terms of reduction of postoperative seroma, chronic pain, and recurrence. This video article presents the endoscopic anatomy of the groin with regard to robotic transabdominal preperitoneal patch plasty (r‑TAPP) and illustrates the surgical steps of r‑TAPP with respective video sequences. The results of a cohort study of 302 consecutive hernias operated by r‑TAPP are presented and discussed in light of the added value of the robotic technique, including advantages for surgical training. r‑TAPP is the natural evolution of conventional TAPP and has the potential to become a new standard as equipment availability increases and material costs decrease. Future studies will also have to refine the multifaceted added value of r‑TAPP with new parameters.}, language = {en} } @article{DietzKudsiGarciaUrenaetal.2021, author = {Dietz, Ulrich A. and Kudsi, O. Yusef and Garcia-Ure{\~n}a, Miguel and Baur, Johannes and Ramser, Michaela and Maksimovic, Sladjana and Keller, Nicola and D{\"o}rfer, J{\"o}rg and Eisner, Lukas and Wiegering, Armin}, title = {Robotic hernia repair III. English version}, series = {Der Chirurg}, volume = {92}, journal = {Der Chirurg}, number = {Suppl 1}, doi = {10.1007/s00104-021-01500-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323896}, pages = {S28-S39}, year = {2021}, abstract = {The principle of targeted separation or weakening of individual components of the abdominal wall to relieve tension in the median line during major abdominal reconstruction has been known for over 30 years as anterior component separation (aCS) and is an established procedure. In search of alternatives with lower complication rates, posterior component separation (pCS) was developed; transversus abdominis release (TAR) is a nerve-sparing modification of pCS. With the ergonomic resources of robotics (e.g., angled instruments), TAR can be performed in a minimally invasive manner (r-TAR): hernia gaps of up to 14 cm can be closed and a large extraperitoneal mesh implanted. In this video article, the treatment of large incisional hernias using the r‑TAR technique is presented. Exemplary results of a cohort study in 13 consecutive patients are presented. The procedure is challenging, but our own results—as well as reports from the literature—are encouraging. The r‑TAR is becoming the pinnacle procedure for abdominal wall reconstruction.}, language = {en} } @article{DenkSchmidtSchurretal.2021, author = {Denk, S. and Schmidt, S. and Schurr, Y. and Schwarz, G. and Schote, F. and Diefenbacher, M. and Armendariz, C. and Dejure, F. and Eilers, M. and Wiegering, Armin}, title = {CIP2A regulates MYC translation (via its 5′UTR) in colorectal cancer}, series = {International Journal of Colorectal Disease}, volume = {36}, journal = {International Journal of Colorectal Disease}, number = {5}, doi = {10.1007/s00384-020-03772-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280092}, pages = {911-918}, year = {2021}, abstract = {Background Deregulated expression of MYC is a driver of colorectal carcinogenesis, suggesting that decreasing MYC expression may have significant therapeutic value. CIP2A is an oncogenic factor that regulates MYC expression. CIP2A is overexpressed in colorectal cancer (CRC), and its expression levels are an independent marker for long-term outcome of CRC. Previous studies suggested that CIP2A controls MYC protein expression on a post-transcriptional level. Methods To determine the mechanism by which CIP2A regulates MYC in CRC, we dissected MYC translation and stability dependent on CIP2A in CRC cell lines. Results Knockdown of CIP2A reduced MYC protein levels without influencing MYC stability in CRC cell lines. Interfering with proteasomal degradation of MYC by usage of FBXW7-deficient cells or treatment with the proteasome inhibitor MG132 did not rescue the effect of CIP2A depletion on MYC protein levels. Whereas CIP2A knockdown had marginal influence on global protein synthesis, we could demonstrate that, by using different reporter constructs and cells expressing MYC mRNA with or without flanking UTR, CIP2A regulates MYC translation. This interaction is mainly conducted by the MYC 5′UTR. Conclusions Thus, instead of targeting MYC protein stability as reported for other tissue types before, CIP2A specifically regulates MYC mRNA translation in CRC but has only slight effects on global mRNA translation. In conclusion, we propose as novel mechanism that CIP2A regulates MYC on a translational level rather than affecting MYC protein stability in CRC.}, language = {en} } @misc{BaurRamserKelleretal.2021, author = {Baur, Johannes and Ramser, Michaela and Keller, Nicola and Muysoms, Filip and D{\"o}rfer, J{\"o}rg and Wiegering, Armin and Eisner, Lukas and Dietz, Ulrich A.}, title = {Erratum to: Robotic hernia repair II. English version Robotic primary ventral and incisional hernia repair (rv-TAPP and r-Rives or r-TARUP). Video report and results of a series of 118 patients}, series = {Der Chirurg}, volume = {92}, journal = {Der Chirurg}, number = {SUPPL 1}, doi = {10.1007/s00104-021-01563-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-326357}, pages = {S27}, year = {2021}, abstract = {No abstract available.}, language = {en} }