@article{BankogluArnoldHeringetal.2018,
  author    = {Bankoglu, Ezgi Eyluel and Arnold, Charlotte and Hering, Ilona and Hankir, Mohammed and Seyfried, Florian and Stopper, Helga},
  title     = {Decreased chromosomal damage in lymphocytes of obese patients after bariatric surgery},
  series = {Scientific Reports},
  volume    = {8},
  journal   = {Scientific Reports},
  number    = {11195},
  doi       = {10.1038/s41598-018-29581-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177090},
  year      = {2018},
  abstract  = {The number of bariatric surgeries being performed worldwide has markedly risen. While the improvement in obesity-associated comorbidities after bariatric surgery is well-established, very little is known about its impact on cancer risk. The peripheral lymphocyte micronucleus test is a widely used method for the monitoring of chromosomal damage levels in vivo, and micronucleus frequency positively correlates with cancer risk. Therefore, the aim of this study was to compare the micronucleus frequency before and after bariatric surgery in obese subjects. Peripheral blood mononuclear cells were collected from 45 obese subjects before and at two time-points after bariatric surgery (6 and 12 months) to assess spontaneous micronucleus frequency. Consistent with the increased cancer risk previously shown, bariatric surgery-induced weight loss led to a significant reduction in lymphocyte micronucleus frequency after 12 months. Interestingly, comorbidities such as type 2 diabetes mellitus and metabolic syndrome further seemed to have an impact on the lymphocyte micronucleus frequency. Our findings may indicate a successful reduction of cancer risk in patients following weight loss caused by bariatric surgery.},
  language  = {en}
}
@phdthesis{Seyfried2008,
  author    = {Seyfried, Florian},
  title     = {Der Wert pr{\"a}diktiver Faktoren bez{\"u}glich der Tumorausbreitung und Differenzierung des Prostatakarzinoms unter Ber{\"u}cksichtigung der Partin Tables},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-27602},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {Evaluation der pr{\"a}operativen Diagnostik (klinisches Staging - digitale rektale Untersuchung, transrektaler Ultraschall -, Prostatastanzbiopsie, Gleason Score, PSA) des Prostatakarzinoms bez{\"u}glich der Tumorausbreitung und des Malignit{\"a}tsgrades. Hierzu wurden unter anderem die Partin Tables als international anerkanntes und reevaluiertes statistisches Nomogramm eingesetzt.},
  subject      = {Prostatakrebs},
  language  = {de}
}
@article{BankogluStippGerberetal.2021,
  author    = {Bankoglu, Ezgi Eyluel and Stipp, Franzisca and Gerber, Johanna and Seyfried, Florian and Heidland, August and Bahner, Udo and Stopper, Helga},
  title     = {Effect of cryopreservation on DNA damage and DNA repair activity in human blood samples in the comet assay},
  series = {Archives of Toxicology},
  volume    = {95},
  journal   = {Archives of Toxicology},
  number    = {5},
  doi       = {10.1007/s00204-021-03012-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265326},
  pages     = {1831-1841},
  year      = {2021},
  abstract  = {The comet assay is a commonly used method to determine DNA damage and repair activity in many types of samples. In recent years, the use of the comet assay in human biomonitoring became highly attractive due to its various modified versions, which may be useful to determine individual susceptibility in blood samples. However, in human biomonitoring studies, working with large sample numbers that are acquired over an extended time period requires some additional considerations. One of the most important issues is the storage of samples and its effect on the outcome of the comet assay. Another important question is the suitability of different blood preparations. In this study, we analysed the effect of cryopreservation on DNA damage and repair activity in human blood samples. In addition, we investigated the suitability of different blood preparations. The alkaline and FPG as well as two different types of repair comet assay and an in vitro hydrogen peroxide challenge were applied. Our results confirmed that cryopreserved blood preparations are suitable for investigating DNA damage in the alkaline and FPG comet assay in whole blood, buffy coat and PBMCs. Ex vivo hydrogen peroxide challenge yielded its optimal effect in isolated PBMCs. The utilised repair comet assay with either UVC or hydrogen peroxide-induced lesions and an aphidicolin block worked well in fresh PBMCs. Cryopreserved PBMCs could not be used immediately after thawing. However, a 16-h recovery with or without mitotic stimulation enabled the application of the repair comet assay, albeit only in a surviving cell fraction.},
  language  = {en}
}
@article{ReimerLockFlemmingetal.2022,
  author    = {Reimer, Stanislaus and Lock, Johan F. and Flemming, Sven and Weich, Alexander and Widder, Anna and Plaßmeier, Lars and D{\"o}ring, Anna and Hering, Ilona and Hankir, Mohammed K. and Meining, Alexander and Germer, Christoph-Thomas and Groneberg, Kaja and Seyfried, Florian},
  title     = {Endoscopic management of large leakages after upper gastrointestinal surgery},
  series = {Frontiers in Surgery},
  volume    = {9},
  journal   = {Frontiers in Surgery},
  issn      = {2296-875X},
  doi       = {10.3389/fsurg.2022.885244},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-274044},
  year      = {2022},
  abstract  = {Background Endoscopic vacuum therapy (EVT) is an evidence-based option to treat anastomotic leakages of the upper gastrointestinal (GI) tract, but the technical challenges and clinical outcomes of patients with large defects remain poorly described. Methods All patients with leakages of the upper GI tract that were treated with endoscopic negative pressure therapy at our institution from 2012-2021 were analyzed. Patients with large defects (>30 mm) as an indicator of complex treatment were compared to patients with smaller defects (control group). Results Ninety-two patients with postoperative anastomotic or staplerline leakages were identified, of whom 20 (21.7\%) had large defects. Compared to the control group, these patients required prolonged therapy (42 vs. 14 days, p < 0.001) and hospital stay (63 vs. 26 days, p < 0.001) and developed significantly more septic complications (40 vs. 17.6\%, p = 0.027.) which often necessitated additional endoscopic and/or surgical/interventional treatments (45 vs. 17.4\%, p = 0.007.) Nevertheless, a resolution of leakages was achieved in 80\% of patients with large defects, which was similar compared to the control group (p = 0.42). Multiple leakages, especially on the opposite side, along with other local unfavorable conditions, such as foreign material mass, limited access to the defect or extensive necrosis occurred significantly more often in cases with large defects (p < 0.001). Conclusions Overall, our study confirms that EVT for leakages even from large defects of the upper GI tract is feasible in most cases but comes with significant technical challenges.},
  language  = {en}
}
@article{ReimerSeyfriedFlemmingetal.2022,
  author    = {Reimer, Stanislaus and Seyfried, Florian and Flemming, Sven and Brand, Markus and Weich, Alexander and Widder, Anna and Plaßmeier, Lars and Kraus, Peter and D{\"o}ring, Anna and Hering, Ilona and Hankir, Mohammed K. and Meining, Alexander and Germer, Christoph-Thomas and Lock, Johan F. and Groneberg, Kaja},
  title     = {Evolution of endoscopic vacuum therapy for upper gastrointestinal leakage over a 10-year period: a quality improvement study},
  series = {Surgical Endoscopy},
  volume    = {36},
  journal   = {Surgical Endoscopy},
  number    = {12},
  doi       = {10.1007/s00464-022-09400-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323953},
  pages     = {9169-9178},
  year      = {2022},
  abstract  = {Background Endoscopic vacuum therapy (EVT) is an effective treatment option for leakage of the upper gastrointestinal (UGI) tract. The aim of this study was to evaluate the clinical impact of quality improvements in EVT management on patients' outcome. Methods All patients treated by EVT at our center during 2012-2021 were divided into two consecutive and equal-sized cohorts (period 1 vs. period 2). Over time several quality improvement strategies were implemented including the earlier diagnosis and EVT treatment and technical optimization of endoscopy. The primary endpoint was defined as the composite score MTL30 (mortality, transfer, length-of-stay > 30 days). Secondary endpoints included EVT efficacy, complications, in-hospital mortality, length-of-stay (LOS) and nutrition status at discharge. Results A total of 156 patients were analyzed. During the latter period the primary endpoint MTL30 decreased from 60.8 to 39.0\% (P = .006). EVT efficacy increased from 80 to 91\% (P = .049). Further, the need for additional procedures for leakage management decreased from 49.9 to 29.9\% (P = .013) and reoperations became less frequent (38.0\% vs.15.6\%; P = .001). The duration of leakage therapy and LOS were shortened from 25 to 14 days (P = .003) and 38 days to 25 days (P = .006), respectively. Morbidity (as determined by the comprehensive complication index) decreased from 54.6 to 46.5 (P = .034). More patients could be discharged on oral nutrition (70.9\% vs. 84.4\%, P = .043). Conclusions Our experience confirms the efficacy of EVT for the successful management of UGI leakage. Our quality improvement analysis demonstrates significant changes in EVT management resulting in accelerated recovery, fewer complications and improved functional outcome.},
  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{HeringDoerriesFlemmingetal.2022,
  author    = {Hering, Ilona and D{\"o}rries, Luise and Flemming, Sven and Krietenstein, Laura and Koschker, Ann-Kathrin and Fassnacht, Martin and Germer, Christoph-Thomas and Hankir, Mohammed K. and Seyfried, Florian},
  title     = {Impact of preoperative weight loss achieved by gastric balloon on peri- and postoperative outcomes of bariatric surgery in super-obese patients: a retrospective matched-pair analysis},
  series = {Langenbeck's Archives of Surgery},
  volume    = {407},
  journal   = {Langenbeck's Archives of Surgery},
  number    = {5},
  doi       = {10.1007/s00423-022-02472-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323909},
  pages     = {1873-1879},
  year      = {2022},
  abstract  = {Background An intragastric balloon is used to cause weight loss in super-obese patients (BMI > 60 kg/m\(^2\)) prior to bariatric surgery. Whether weight loss from intragastric balloon influences that from bariatric surgery is poorly studied. Methods In this retrospective, single-center study, the effects of intragastric balloon in 26 patients (BMI 69.26 ± 6.81) on weight loss after bariatric surgery (primary endpoint), postoperative complications within 30 days, hospital readmission, operation time, and MTL30 (secondary endpoints) were evaluated. Fifty-two matched-pair patients without intragastric balloon prior to bariatric surgery were used as controls. Results Intragastric balloon resulted in a weight loss of 17.3 ± 14.1 kg (BMI 5.75 ± 4.66 kg/m\(^2\)) with a nadir after 5 months. Surgical and postoperative outcomes including complications were comparable between both groups. Total weight loss was similar in both groups (29.0\% vs. 32.2\%, p = 0.362). Direct postoperative weight loss was more pronounced in the control group compared to the gastric balloon group (29.16 ± 7.53\% vs 23.78 ± 9.89\% after 1 year, p < 0.05 and 32.13 ± 10.5\% vs 22.21 ± 10.9\% after 2 years, p < 0.05), who experienced an earlier nadir and started to regain weight during the follow-up. Conclusion A multi-stage therapeutic approach with gastric balloon prior to bariatric surgery in super-obese patients may be effective to facilitate safe surgery. However, with the gastric balloon, pre-treated patients experienced an attenuated postoperative weight loss with an earlier nadir and earlier body weight regain. This should be considered when choosing the appropriate therapeutic regime and managing patients' expectations.},
  language  = {en}
}
@article{SeyfriedvonRahdenMirasetal.2015,
  author    = {Seyfried, Florian and von Rahden, Burkhard H. and Miras, Alexander D. and Gasser, Martin and Maeder, Uwe and Kunzmann, Volker and Germer, Christoph-Thomas and Pelz, J{\"o}rg O. W. and Kerscher, Alexander G.},
  title     = {Incidence, time course and independent risk factors for metachronous peritoneal carcinomatosis of gastric origin - a longitudinal experience from a prospectively collected database of 1108 patients},
  series = {BMC Cancer},
  volume    = {15},
  journal   = {BMC Cancer},
  number    = {73},
  doi       = {10.1186/s12885-015-1081-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125014},
  year      = {2015},
  abstract  = {Background Comprehensive evidence on the incidence, time course and independent risk factors of metachronous peritoneal carcinomatosis (metaPC) in gastric cancer patients treated with curative intent in the context of available systemic combination chemotherapies is lacking. Methods Data from a prospectively collected single-institutional Center Cancer Registry with 1108 consecutive patients with gastric adenocarcinoma (GC), clinical, histological and survival data were analyzed for independent risk factors and prognosis with focus on the development of metaPC. Findings were then stratified to the time periods of treatment with surgery alone, 5-Fluorouracil-only and contemporary combined systemic perioperative chemotherapy strategies, respectively. Results Despite R0 D2 gastrectomy (n = 560), 49.6\% (±5.4\%) of the patients were diagnosed with tumour recurrence and 15.5\% (±1.8\%) developed metaPC after a median time of 17.7 (15.1-20.3) months after surgery resulting in a tumour related mortality of 100\% with a median survival of 3.0 months (2.1 - 4.0). Independent risk factors for the development of metaPC were serosa positive T-category, nodal positive-status, signet cell and undifferentiated gradings (G3/G4). Contemporary systemic combination chemotherapy did not improve the incidence and prognosis of metaPC (p = 0.54). Conclusions Despite significant improvements in the overall survival for the complete cohort with gastric cancer over time, those patients with metaPC did not experience the same benefits. The lack of change in the incidence, and persistent poor prognosis of metaPC after curative surgery expose the need for further prevention and/or improved treatment options for this devastating condition.},
  language  = {en}
}
@article{HankirSeyfriedSchellingeretal.2021,
  author    = {Hankir, Mohammed K. and Seyfried, Florian and Schellinger, Isabel N. and Schlegel, Nicolas and Arora, Tulika},
  title     = {Leaky gut as a potential culprit for the paradoxical dysglycemic response to gastric bypass-associated ileal microbiota},
  series = {Metabolites},
  volume    = {11},
  journal   = {Metabolites},
  number    = {3},
  issn      = {2218-1989},
  doi       = {10.3390/metabo11030153},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234085},
  year      = {2021},
  abstract  = {Altered host-intestinal microbiota interactions are increasingly implicated in the metabolic benefits of Roux-en-Y gastric bypass (RYGB) surgery. We previously found, however, that RYGB-associated ileal microbiota can paradoxically impair host glycemic control when transferred to germ-free mice. Here we present complementary evidence suggesting that this could be due to the heightened development of systemic endotoxemia. Consistently, application of ileal content from RYGB-treated compared with sham-operated rats onto Caco-2 cell monolayers compromised barrier function and decreased expression of the barrier-stabilizing proteins claudin-4 and desmoglein-2. Our findings raise the possibility that RYGB-associated ileal microbiota produce and release soluble metabolites which locally increase intestinal permeability to promote systemic endotoxemia-induced insulin resistance, with potential implications for the treatment of RYGB patients who eventually relapse onto type 2 diabetes.},
  language  = {en}
}
@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}
}