@article{JurowichOttoRikkalaetal.2015,
  author    = {Jurowich, Christian Ferdinand and Otto, Christoph and Rikkala, Prashanth Reddy and Wagner, Nicole and Vrhovac, Ivana and Sabolić, Ivan and Germer, Christoph-Thomas and Koepsell, Hermann},
  title     = {Ileal interposition in rats with experimental type 2 like diabetes improves glycemic control independently of glucose absorption},
  series = {Journal of Diabetes Research},
  volume    = {2015},
  journal   = {Journal of Diabetes Research},
  number    = {490365},
  doi       = {10.1155/2015/490365},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149166},
  year      = {2015},
  abstract  = {Bariatric operations in obese patients with type 2 diabetes often improve diabetes before weight loss is observed. In patients mainly Roux-en-Y-gastric bypass with partial stomach resection is performed. Duodenojejunal bypass (DJB) and ileal interposition (IIP) are employed in animal experiments. Due to increased glucose exposition of L-cells located in distal ileum, all bariatric surgery procedures lead to higher secretion of antidiabetic glucagon like peptide-1 (GLP-1) after glucose gavage. After DJB also downregulation of Na\(^{+}\)-D-glucose cotransporter SGLT1 was observed. This suggested a direct contribution of decreased glucose absorption to the antidiabetic effect of bariatric surgery. To investigate whether glucose absorption is also decreased after IIP, we induced diabetes with decreased glucose tolerance and insulin sensitivity in male rats and investigated effects of IIP on diabetes and SGLT1. After IIP, we observed weight-independent improvement of glucose tolerance, increased insulin sensitivity, and increased plasma GLP-1 after glucose gavage. The interposed ileum was increased in diameter and showed increased length of villi, hyperplasia of the epithelial layer, and increased number of L-cells. The amount of SGLT1-mediated glucose uptake in interposed ileum was increased 2-fold reaching the same level as in jejunum. Thus, improvement of glycemic control by bariatric surgery does not require decreased glucose absorption.},
  language  = {en}
}
@phdthesis{Stingl2009,
  author    = {Stingl, Maria-Theresa},
  title     = {Kurz- und Langzeitergebnisse des laparoskopischen Gastric Banding (eine retrospektive Studie an 127 Patienten)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-38672},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2009},
  abstract  = {Die laparoskopische Implantation eines Magenbandes gilt als etabliertes Verfahren der bariatrischen Chirurgie. Im Rahmen der vorliegenden retrospektiven Studie an 127 Patienten wurden die Kurz- und Langzeitergebnisse des Laparoskopischen Gastric Banding (LAGB) untersucht. 60 Patienten wurden in Pergastrischer Technik, 67 Patienten in Pars flaccida Technik operiert. Untersucht wurde Sicherheit, Effizienz und Qualit{\"a}t des LAGB insbesondere im Hinblick auf die Art der angewandten Operationstechnik. Die mittlere Nachbeobachtungszeit betrug 63 Monate. Der mittlere prozentuale {\"U}bergewichtsverlust (EBWL \%) war 50,6 \%. Bei 39 Patienten traten ein oder mehrere Komplikationen auf. Die h{\"a}ufigsten Komplikationen waren Slippage und Pouchdilatation. Die Mortalit{\"a}tsrate lag bei 0 \%. {\"U}ber 2/3 der Patienten dokumentierten eine Steigerung der subjektiven Lebensqualit{\"a}t durch das LAGB. Im Vergleich der Ergebnisse zweier verschiedener Operationstechniken stellte sich heraus, dass die Wahl des operativen Zugangsweges weder einen Einfluss auf die Effektivit{\"a}t der Gewichtsabnahme noch auf die Reduktion der k{\"o}rpergewichtsbedingten Komorbidit{\"a}t hat. In {\"U}bereinstimmung mit Ergebnissen anderer Studien zeigten sich Vorteile der Pars flaccida Technik im Sinne einer niedrigeren postoperativen Komplikationsrate. Insbesondere die sehr h{\"a}ufigen Komplikationen Pouchdilatation und Slippage traten in der Pars flaccida Gruppe signifikant seltener auf als bei den Patienten, die in Pergastrischer Technik operiert wurden. Zur Erh{\"o}hung der Effizienz sowie Reduktion der Komplikationsrate des LAGB ist - {\"u}ber die Optimierung operativ-technischer Aspekte hinaus- eine professionelle, interdisziplin{\"a}re und langfristige Nachbetreuung der Patienten unabdingbar.},
  subject      = {Gastric-banding},
  language  = {de}
}
@article{Koepsell2020,
  author    = {Koepsell, Hermann},
  title     = {Glucose transporters in the small intestine in health and disease},
  series = {Pfl{\"u}gers Archiv - European Journal of Physiology},
  volume    = {472},
  journal   = {Pfl{\"u}gers Archiv - European Journal of Physiology},
  issn      = {0031-6768},
  doi       = {10.1007/s00424-020-02439-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232552},
  pages     = {1207-1248},
  year      = {2020},
  abstract  = {Absorption of monosaccharides is mainly mediated by Na\(^+\)-d-glucose cotransporter SGLT1 and the facititative transporters GLUT2 and GLUT5. SGLT1 and GLUT2 are relevant for absorption of d-glucose and d-galactose while GLUT5 is relevant for d-fructose absorption. SGLT1 and GLUT5 are constantly localized in the brush border membrane (BBM) of enterocytes, whereas GLUT2 is localized in the basolateral membrane (BLM) or the BBM plus BLM at low and high luminal d-glucose concentrations, respectively. At high luminal d-glucose, the abundance SGLT1 in the BBM is increased. Hence, d-glucose absorption at low luminal glucose is mediated via SGLT1 in the BBM and GLUT2 in the BLM whereas high-capacity d-glucose absorption at high luminal glucose is mediated by SGLT1 plus GLUT2 in the BBM and GLUT2 in the BLM. The review describes functions and regulations of SGLT1, GLUT2, and GLUT5 in the small intestine including diurnal variations and carbohydrate-dependent regulations. Also, the roles of SGLT1 and GLUT2 for secretion of enterohormones are discussed. Furthermore, diseases are described that are caused by malfunctions of small intestinal monosaccharide transporters, such as glucose-galactose malabsorption, Fanconi syndrome, and fructose intolerance. Moreover, it is reported how diabetes, small intestinal inflammation, parental nutrition, bariatric surgery, and metformin treatment affect expression of monosaccharide transporters in the small intestine. Finally, food components that decrease d-glucose absorption and drugs in development that inhibit or downregulate SGLT1 in the small intestine are compiled. Models for regulations and combined functions of glucose transporters, and for interplay between d-fructose transport and metabolism, are discussed.},
  language  = {en}
}
@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}
}
@article{RullmannPreusserPoppitzetal.2019,
  author    = {Rullmann, Michael and Preusser, Sven and Poppitz, Sindy and Heba, Stefanie and Gousias, Konstantinos and Hoyer, Jana and Sch{\"u}tz, Tatjana and Dietrich, Arne and M{\"u}ller, Karsten and Hankir, Mohammed K. and Pleger, Burkhard},
  title     = {Adiposity Related Brain Plasticity Induced by Bariatric Surgery},
  series = {Froniers in Human Neuroscience},
  volume    = {13},
  journal   = {Froniers in Human Neuroscience},
  doi       = {10.3389/fnhum.2019.00290},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227168},
  pages     = {1-11},
  year      = {2019},
  abstract  = {Previous magnetic resonance imaging (MRI) studies revealed structural-functional brain reorganization 12 months after gastric-bypass surgery, encompassing cortical and subcortical regions of all brain lobes as well as the cerebellum. Changes in the mean of cluster-wise gray/white matter density (GMD/WMD) were correlated with the individual loss of body mass index (BMI), rendering the BMI a potential marker of widespread surgery-induced brain plasticity. Here, we investigated voxel-by-voxel associations between surgery-induced changes in adiposity, metabolism and inflammation and markers of functional and structural neural plasticity. We re-visited the data of patients who underwent functional and structural MRI, 6 months (n = 27) and 12 months after surgery (n = 22), and computed voxel-wise regression analyses. Only the surgery-induced weight loss was significantly associated with brain plasticity, and this only for GMD changes. After 6 months, weight loss overlapped with altered GMD in the hypothalamus, the brain's homeostatic control site, the lateral orbitofrontal cortex, assumed to host reward and gustatory processes, as well as abdominal representations in somatosensory cortex. After 12 months, weight loss scaled with GMD changes in right cerebellar lobule VII, involved in language-related/cognitive processes, and, by trend, with the striatum, assumed to underpin (food) reward. These findings suggest time-dependent and weight-loss related gray matter plasticity in brain regions involved in the control of eating, sensory processing and cognitive functioning.},
  language  = {en}
}
@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}
}