@article{HankirPattPattetal.2017,
  author    = {Hankir, Mohammed K. and Patt, Marianne and Patt, J{\"o}rg T. W. and Becker, Georg A. and Rullmann, Michael and Kranz, Mathias and Deuther-Conrad, Winnie and Schischke, Kristin and Seyfried, Florian and Brust, Peter and Hesse, Swen and Sabri, Osama and Kr{\"u}gel, Ute and Fenske, Wiebke},
  title     = {Suppressed fat appetite after Roux-en-Y gastric bypass surgery associates with reduced brain mu-opioid receptor availability in diet-induced obese male rats},
  series = {Frontiers in Neuroscience},
  volume    = {10},
  journal   = {Frontiers in Neuroscience},
  doi       = {10.3389/fnins.2016.00620},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-181130},
  year      = {2017},
  abstract  = {Brain μ-opioid receptors (MORs) stimulate high-fat (HF) feeding and have been implicated in the distinct long term outcomes on body weight of bariatric surgery and dieting. Whether alterations in fat appetite specifically following these disparate weight loss interventions relate to changes in brain MOR signaling is unknown. To address this issue, diet-induced obese male rats underwent either Roux-en-Y gastric bypass (RYGB) or sham surgeries. Postoperatively, animals were placed on a two-choice diet consisting of low-fat (LF) and HF food and sham-operated rats were further split into ad libitum fed (Sham-LF/HF) and body weight-matched (Sham-BWM) to RYGB groups. An additional set of sham-operated rats always only on a LF diet (Sham-LF) served as lean controls, making four experimental groups in total. Corresponding to a stage of weight loss maintenance for RYGB rats, two-bottle fat preference tests in conjunction with small-animal positron emission tomography (PET) imaging studies with the selective MOR radioligand [\(^{11}\)C]carfentanil were performed. Brains were subsequently collected and MOR protein levels in the hypothalamus, striatum, prefrontal cortex and orbitofrontal cortex were analyzed by Western Blot. We found that only the RYGB group presented with intervention-specific changes: having markedly suppressed intake and preference for high concentration fat emulsions, a widespread reduction in [\(^{11}\)C]carfentanil binding potential (reflecting MOR availability) in various brain regions, and a downregulation of striatal and prefrontal MOR protein levels compared to the remaining groups. These findings suggest that the suppressed fat appetite caused by RYGB surgery is due to reduced brain MOR signaling, which may contribute to sustained weight loss unlike the case for dieting.},
  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{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{DischingerHeckelBischleretal.2021,
  author    = {Dischinger, Ulrich and Heckel, Tobias and Bischler, Thorsten and Hasinger, Julia and K{\"o}nigsrainer, Malina and Schmitt-B{\"o}hrer, Angelika and Otto, Christoph and Fassnacht, Martin and Seyfried, Florian and Hankir, Mohammed Khair},
  title     = {Roux-en-Y gastric bypass and caloric restriction but not gut hormone-based treatments profoundly impact the hypothalamic transcriptome in obese rats},
  series = {Nutrients},
  volume    = {14},
  journal   = {Nutrients},
  number    = {1},
  issn      = {2072-6643},
  doi       = {10.3390/nu14010116},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252392},
  year      = {2021},
  abstract  = {Background: The hypothalamus is an important brain region for the regulation of energy balance. Roux-en-Y gastric bypass (RYGB) surgery and gut hormone-based treatments are known to reduce body weight, but their effects on hypothalamic gene expression and signaling pathways are poorly studied. Methods: Diet-induced obese male Wistar rats were randomized into the following groups: RYGB, sham operation, sham + body weight-matched (BWM) to the RYGB group, osmotic minipump delivering PYY3-36 (0.1 mg/kg/day), liraglutide s.c. (0.4 mg/kg/day), PYY3-36 + liraglutide, and saline. All groups (except BWM) were kept on a free choice of high- and low-fat diets. Four weeks after interventions, hypothalami were collected for RNA sequencing. Results: While rats in the RYGB, BWM, and PYY3-36 + liraglutide groups had comparable reductions in body weight, only RYGB and BWM treatment had a major impact on hypothalamic gene expression. In these groups, hypothalamic leptin receptor expression as well as the JAK-STAT, PI3K-Akt, and AMPK signaling pathways were upregulated. No significant changes could be detected in PYY3-36 + liraglutide-, liraglutide-, and PYY-treated groups. Conclusions: Despite causing similar body weight changes compared to RYGB and BWM, PYY3-36 + liraglutide treatment does not impact hypothalamic gene expression. Whether this striking difference is favorable or unfavorable to metabolic health in the long term requires further investigation.},
  language  = {en}
}
@article{WidderKelmReibetanzetal.2022,
  author    = {Widder, Anna and Kelm, Matthias and Reibetanz, Joachim and Wiegering, Armin and Matthes, Niels and Germer, Christoph-Thomas and Seyfried, Florian and Flemming, Sven},
  title     = {Robotic-assisted versus laparoscopic left hemicolectomy — postoperative inflammation status, short-term outcome and cost effectiveness},
  series = {International Journal of Environmental Research and Public Health},
  volume    = {19},
  journal   = {International Journal of Environmental Research and Public Health},
  number    = {17},
  issn      = {1660-4601},
  doi       = {10.3390/ijerph191710606},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286203},
  year      = {2022},
  abstract  = {Robotic-assisted colon surgery may contain advantages over the laparoscopic approach, but clear evidence is sparse. This study aimed to analyze postoperative inflammation status, short-term outcome and cost-effectiveness of robotic-assisted versus laparoscopic left hemicolectomy. All consecutive patients who received minimal-invasive left hemicolectomy at the Department of Surgery I at the University Hospital of Wuerzburg in 2021 were prospectively included. Importantly, no patient selection for either procedure was carried out. The robotic-assisted versus laparoscopic approaches were compared head to head for postoperative short-term outcomes as well as cost-effectiveness. A total of 61 patients were included, with 26 patients having received a robotic-assisted approach. Baseline characteristics did not differ among the groups. Patients receiving a robotic-assisted approach had a significantly decreased length of hospital stay as well as lower rates of complications in comparison to patients who received laparoscopic surgery (n = 35). In addition, C-reactive protein as a marker of systemic stress response was significantly reduced postoperatively in patients who were operated on in a robotic-assisted manner. Consequently, robotic-assisted surgery could be performed in a cost-effective manner. Thus, robotic-assisted left hemicolectomy represents a safe and cost-effective procedure and might improve patient outcomes in comparison to laparoscopic surgery.},
  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{MetznerHerzogHeckeletal.2022,
  author    = {Metzner, Valentin and Herzog, Gloria and Heckel, Tobias and Bischler, Thorsten and Hasinger, Julia and Otto, Christoph and Fassnacht, Martin and Geier, Andreas and Seyfried, Florian and Dischinger, Ulrich},
  title     = {Liraglutide + PYY\(_{3-36}\) combination therapy mimics effects of Roux-en-Y bypass on early NAFLD whilst lacking-behind in metabolic improvements},
  series = {Journal of Clinical Medicine},
  volume    = {11},
  journal   = {Journal of Clinical Medicine},
  number    = {3},
  issn      = {2077-0383},
  doi       = {10.3390/jcm11030753},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-255244},
  year      = {2022},
  abstract  = {Background: Treatment options for NAFLD are still limited. Bariatric surgery, such as Roux-en-Y gastric bypass (RYGB), has been shown to improve metabolic and histologic markers of NAFLD. Glucagon-like-peptide-1 (GLP-1) analogues lead to improvements in phase 2 clinical trials. We directly compared the effects of RYGB with a treatment using liraglutide and/or peptide tyrosine tyrosine 3-36 (PYY\(_{3-36}\)) in a rat model for early NAFLD. Methods: Obese male Wistar rats (high-fat diet (HFD)-induced) were randomized into the following treatment groups: RYGB, sham-operation (sham), liraglutide (0.4 mg/kg/day), PYY\(_{3-36}\) (0.1 mg/kg/day), liraglutide+PYY\(_{3-36}\), and saline. After an observation period of 4 weeks, liver samples were histologically evaluated, ELISAs and RNA sequencing + RT-qPCRs were performed. Results: RYGB and liraglutide+PYY\(_{3-36}\) induced a similar body weight loss and, compared to sham/saline, marked histological improvements with significantly less steatosis. However, only RYGB induced significant metabolic improvements (e.g., adiponectin/leptin ratio 18.8 ± 11.8 vs. 2.4 ± 1.2 in liraglutide+PYY\(_{3-36}\)- or 1.4 ± 0.9 in sham-treated rats). Furthermore, RNA sequencing revealed a high number of differentially regulated genes in RYGB treated animals only. Conclusions: The combination therapy of liraglutide+PYY\(_{3-36}\) partly mimics the positive effects of RYGB on weight reduction and on hepatic steatosis, while its effects on metabolic function lack behind RYGB.},
  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}
}
@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}
}