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ABSTRACT: The goal of this study was to evaluate high-field open magnetic resonance imaging (MRI) for intraoperative real-time imaging during hand-assisted laparoscopic liver resection. MR guidance has several advantages compared to ultrasound and may represent a future technique for abdominal surgery. Various MRI-safe and -compatible instruments were developed, tested, and applied to realize minimally invasive liver surgery under MR guidance. As proof of the concept, liver resection was performed in a porcine model.
All procedures were conducted in a 1.0-T open MRI unit. Imaging quality and surgical results were documented during three cadaveric and two live animal procedures. A nonferromagnetic hand port was used for manual access and the liver tissue was dissected using a Nd:YAG laser.
The intervention time ranged from 126 to 145 min, with a dissection time from 11 to 15 min. Both live animals survived the intervention with a blood loss of 250 and 170 ml and a specimen weight of 138 and 177 g. A dynamic T2W fast spin-echo sequence allowed real-time imaging (1.5 s/image) with good delineation of major and small hepatic vessels. The newly developed MR-compatible instruments and camera system caused only minor interferences and artifacts of the MR image.
MR-guided liver resection is feasible and provides additional image information to the surgeon. We conclude that MR-guided laparoscopic liver resection improves the anatomical orientation and may increase the safety of future minimally invasive liver surgery.
Surgical Endoscopy 03/2010; 24(10):2506-12. · 4.01 Impact Factor
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Journal of Gastroenterology 02/2010; · 4.16 Impact Factor
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ABSTRACT: In the past decade, a strong argument has been built for the role of serotonin (5HT) and the serotonin transporter (SERT) in irritable bowel syndrome (IBS). However, it is still not clear how SERT contributes to this clinically heterogeneous disease. The present study addressed this issue by implementing platelet (plt) markers of SERT activity in the assessment protocol.
Fasting blood samples of 149 (51 male/98 female) subjects with Rome II and III defined IBS subtypes, and 163 healthy control subjects (CSs; 75 male/88 female) were analyzed for platelet 5HT concentration and 5HT uptake activity [maximum uptake rate (V (max)) and affinity constant (K (m))].
Gender had a significant impact on platelet markers of SERT activity. Male IBS patients showed significantly lower median V (max) and K (m) values than the male CS (V (max) 1.706 vs. 2.148 nmol/10(9) plts x min, P < 0.001; K (m) 346 vs. 410 nmol, P = 0.008) without any significant reduction in platelet 5HT concentration (362 vs. 394 ng/10(9) plts). On the other hand, V (max) values were not different between female IBS patients and female CS (1.642 vs. 1.741 nmol/10(9) plts x min), but platelet 5HT concentration was significantly lower in females with diarrhea-predominant IBS (363 vs. 435 ng/10(9) plts, P < 0.05).
Although an absolute extrapolation from platelets to the gastrointestinal tissue does not appear to be justified, our findings demonstrated that the contribution of disturbed SERT activity to IBS is not uniform and is possibly gender-specific. The results suggest that an assessment of SERT function in platelets may help to elucidate the differences between IBS patients in response to drugs affecting the 5HT system.
Journal of Gastroenterology 12/2009; 45(4):389-98. · 4.16 Impact Factor
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Christian J Seebauer,
Hermann J Bail,
Florian Wichlas,
Tobias Jung,
Ioannis S Papanikolaou, Ivo van der Voort,
Jens C Rump,
René Schilling,
Andreas Winkelmann,
Thula Walther,
Sasha S Chopra,
Ulf K M Teichgräber
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ABSTRACT: The institutional review board approved the use of cadaveric specimens, and informed consent was obtained from all volunteers. The authors performed and assessed a magnetic resonance (MR)-assisted navigation method for minimally invasive retrograde drilling of talar osteochondral lesions. For this method, a single imaging plane is sufficient for navigation during intervention. To accomplish this objective, a passive MR navigation device was used to evaluate 16 cadaveric ankle joints. Use of this interactive MR-assisted navigation method in combination with a passive aiming device allowed precise and rapid retrograde drilling of talar osteochondral lesions.
Radiology 07/2009; 252(3):857-64. · 5.73 Impact Factor
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Johannes Kapeller,
Lesley A Houghton,
Hubert Mönnikes,
Jutta Walstab,
Dorothee Möller,
Heinz Bönisch,
Barbara Burwinkel,
Frank Autschbach,
Benjamin Funke,
Felix Lasitschka, [......],
Peter J Whorwell,
Wendy Atkinson,
Catherine Fell,
Karl J Büchner,
Marco Schmidtmann, Ivo van der Voort,
Anna-Sophia Wisser,
Thomas Berg,
Gudrun Rappold,
Beate Niesler
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ABSTRACT: Diarrhea predominant irritable bowel syndrome (IBS-D) is a complex disorder related to dysfunctions in the serotonergic system. As cis-regulatory variants can play a role in the etiology of complex conditions, we investigated the untranslated regions (UTRs) of the serotonin receptor type 3 subunit genes HTR3A and HTR3E. Mutation analysis was carried out in a pilot sample of 200 IBS patients and 100 healthy controls from the UK. The novel HTR3E 3'-UTR variant c.*76G>A (rs62625044) was associated with female IBS-D (P = 0.033, OR = 8.53). This association was confirmed in a replication study, including 119 IBS-D patients and 195 controls from Germany (P = 0.0046, OR = 4.92). Pooled analysis resulted in a highly significant association of c.*76G>A with female IBS-D (P = 0.0002, OR = 5.39). In a reporter assay, c.*76G>A affected binding of miR-510 to the HTR3E 3'-UTR and caused elevated luciferase expression. HTR3E and miR-510 co-localize in enterocytes of the gut epithelium as shown by in situ hybridization and RT-PCR. This is the first example indicating micro RNA-related expression regulation of a serotonin receptor gene with a cis-regulatory variant affecting this regulation and appearing to be associated with female IBS-D.
Human Molecular Genetics 07/2008; 17(19):2967-77. · 7.64 Impact Factor
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Peter Kobelt,
Anna-Sophia Wisser,
Andreas Stengel,
Miriam Goebel,
Tobias Inhoff,
Steffen Noetzel,
Rüdiger W Veh,
Norbert Bannert, Ivo van der Voort,
Bertram Wiedenmann,
Burghard F Klapp,
Yvette Taché,
Hubert Mönnikes
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ABSTRACT: Peripheral ghrelin has been shown to act as a gut-brain peptide exerting a potent orexigenic effect on food intake. The dorsomedial nucleus of the hypothalamus (DMH) is innervated by projections from other brain areas being part of the network of nuclei controlling energy homeostasis, among others NPY/AgRP-positive fibers arising from the arcuate nucleus (ARC). The aim of the study was to determine if peripherally administered ghrelin affects neuronal activity in the DMH, as assessed by Fos expression. The number of Fos positive neurons was determined in the DMH, paraventricular nucleus of the hypothalamus (PVN), ARC, ventromedial hypothalamic nucleus (VMH), nucleus of the solitary tract (NTS) and in the area postrema (AP) in non-fasted Sprague-Dawley rats in response to intraperitoneally (ip) injected ghrelin (3 nmol/rat) or vehicle (0.15 M NaCl). Peripheral ghrelin induced a significant increase in the number of Fos-ir positive neurons/section compared with vehicle in the ARC (mean+/-SEM: 49+/-2 vs. 23+/-2 neurons/section, p=0.001), PVN (69+/-5 vs. 34+/-3, p=0.001), and DMH (142+/-5 vs. 83+/-5, p<0.001). Fos-ir positive neurons were mainly localized within the ventral part of the DMH. No change in Fos expression was observed in the VMH (53+/-8 vs. 48+/-6, p=0.581), NTS (42+/-2 vs. 40+/-3, p=0.603), and in the AP (7+/-1 vs. 5+/-1, p=0.096). Additional double-labelling with anti-Fos and anti-AgRP revealed that Fos positive neurons in the DMH were encircled by a network of AgRP-ir positive fibers. These data indicate that peripheral ghrelin activates DMH neurons and that NPY-/AgRP-positive fibers may be involved in the response.
Brain Research 05/2008; 1204:77-86. · 2.73 Impact Factor
