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- 2014 (15) (entfernen)
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- evidence-based medicine (3)
- guidelines (3)
- indication for surgery (3)
- laparoscopic ventral hernia repair (3)
- perioperative management (3)
- Laparoskopie (2)
- 5-Fluorouracil (1)
- Adipositas (1)
- Alloantigenerkennung (1)
- Bariatric surgery (1)
Institut
- Klinik und Poliklinik für Allgemein-, Viszeral-, Gefäß- und Kinderchirurgie (Chirurgische Klinik I) (15) (entfernen)
EU-Projektnummer / Contract (GA) number
- 241592 (1)
Untersuchungen zum antikanzerogenen Potenzial von Targetstrukturen im Stoffwechsel von Tumorzellen
(2014)
In der Onkologie bleibt das grundlegende Ziel, neue Strukturen zu identifizieren und ihre Eignung für therapeutische Ansätze zu prüfen. Seit einigen Jahren wird der Stoffwechsel von Tumoren als zur Entwicklung neuer Therapiestrategien untersucht, nachdem dieser bereits Anfang des 20. Jahrhunderts im Fokus des wissenschaftlichen Interesses stand. So berichtete der Nobelpreisträger Otto Warburg bereits im Jahr 1923 über eine starke Bildung von Milchsäure an Gewebeschnitten solider Tumoren in Gegenwart von Sauerstoff. Für diese Eigenschaft von Tumoren, die bei normalen Körperzellen nicht beobachtet wird, hat sich die Bezeichnung „Warburg-Effekt“ durchgesetzt, der als Anpassung an die in soliden Tumoren vorherrschenden Sauerstoffbedingungen interpretiert wird.
Der Warburg-Effekt führt dazu, dass Tumorzellen einen so genannten glykolytische Stoffwechsel aufweisen, der durch einen hohen Glukoseumsatz in der Glykolyse und eine massive Bildung von Laktat charakterisiert ist. Wird die Tumorzelle daran gehindert, die für die Glykolyse notwendigen Reduktionsäquivalente mit Hilfe der Laktatdehydrogenase zu reoxidieren, verringert sich der Umsatz von Glukose über die Glykolyse und die Tumorzelle gerät in ein Energiedefizit. Wird die Tumorzelle daran gehindert, Laktat aus dem Zellinne-ren über die Transporter MCT1 und MCT4 nach außen zu schleusen, so kommt es zu einer intrazellulären Übersäuerung. Beide Strategien führen zum Zelltod. Als Hemmstoff für die Zielstruktur Laktatdehydrogenase wurde Natri-umoxamat (NaOx) und als Hemmstoff für die Zielstruktur MCT1 bzw. MCT4 wurde α-Cyano-4-Hydroxyzimtsäure (CHC) gewählt. Ihre Wirkung auf die Zellvitalität und den Zellstoffwechsel wurde an der Zervixkarzinomzelllinie SiHa und der kolorektalen Adenokarzinomzelllinie WiDr untersucht, die beide sowohl die Laktatdehydrogenase LDH-A als auch die Monocarboxylat-Transporter MCT1 und MCT4 exprimieren. Die Untersuchungen zum Tumorstoffwechsel wurden bei Sauerstoffkonzentrationen von 5 % und 1 % durchgeführt.
Bei SiHa war die Hemmung des Laktatexports durch den MCT-Inhibitor CHC erfolgreich und bewirkte eine starke Inhibition des Zellwachstums auch in Hypoxie (1 % Sauerstoff). Die Inkubation mit CHC führte bereits nach 48 Stunden zu zelltoxischen Effekten; nach 120 Stunden lag der Anteil vitaler Zellen nur noch bei 50 %. Die CHC-vermittelte Hemmung der MCT verringerte bei SiHa den Verbrauch an Glukose um ca. 50 % und die Produktion von Laktat um ca. 40 % nach 24 Stunden. Auch bei WiDr wurden durch CHC ausgelöste zelltoxische Effekte bereits nach 24 Stunden beobachtet.
Die Hemmung der Laktatdehydrogenase verminderte in beiden Tumorzelllinien eindeutig die Laktatbildung und gleichzeitig den Glukoseverbrauch um mehr als 50 % innerhalb von 24 Stunden. Dabei nahm die Wirksamkeit der LDH-Inhibition mit abnehmender Sauerstoffkonzentration zu. Während das Zellwachstum bei 5 % Sauerstoff verzögert war, nahm bei 1 % Sauerstoff der Anteil vitaler Zellen um ca. 50 % ab.
Die Daten zur Kombination aus Natriumoxamat und 5-FU belegen, dass die Inhibition der Laktatdehydrogenase die Wirksamkeit von 5-FU erhöht und dass diese Kombination nicht nur bei 21 % Sauerstoff wirksam ist, sondern auch bei der für Tumoren physiologisch relevanteren Sauerstoffkonzentration von 1 %.
Die Ergebnisse der vorliegenden Arbeit bestätigen als „proof of concept“, dass die Hemmung der Laktatdehydrogenase und der MCT zur Inhibition des glykolytischen Stoffwechsels von Tumorzellen führt. Weitere Untersuchungen sind zweifelsohne notwendig, um die molekularen Mechanismen im Detail zu verstehen, doch scheinen beide Strategien über das prinzipielle Potential zur Entwicklung einer neuartigen Form der Krebstherapie zu verfügen. Dabei wird sicherlich von Bedeutung sein, dass beide Strategien insbesondere in Hypoxie, in der die Wirksamkeit von Chemotherapeutika und Strahlentherapie begrenzt ist, ebenfalls Effekte aufweisen.
Untersuchung der postoperativen Lebensqualität und der Zufriedenheit mit dem kosmetischen Ergebnis bei Patienten mit Single Port Cholezystektomie (SPC) und Standard Multiport laparoskopischer Cholezystektomie (SMLC). Es erfolgte ein Patienteninterview mit dem Body Image Questionnaire (BIQ) und dem Short Form 12 Health Survey (SF-12). Die Patienten mit SPC hatten eine signifikant höhere Zufriedenheit mit dem kosmetischen Resultat der Narbe, während die Lebensqualität sich nicht signifikant unterschied.
Guidelines are increasingly determining the decision process in day-to-day clinical work. Guidelines describe the current best possible standard in diagnostics and therapy. They should be developed by an international panel of experts, whereby alongside individual experience, above all, the results of comparative studies are decisive. According to the results of high-ranking scientific studies published in peer-reviewed journals, statements and recommendations are formulated, and these are graded strictly according to the criteria of evidence-based medicine. Guidelines can therefore be valuable in helping particularly the young surgeon in his or her day-to-day work to find the best decision for the patient when confronted with a wide and confusing range of options. However, even experienced surgeons benefit because by virtue of a heavy workload and commitment, they often find it difficult to keep up with the ever-increasing published literature. All guidelines require regular updating, usually every 3 years, in line with progress in the field. The current Guidelines focus on technique and perioperative management of laparoscopic ventral hernia repair and constitute the first comprehensive guidelines on this topic. In this issue of Surgical Endoscopy, the first part of the Guidelines is published including sections on basics, indication for surgery, perioperative management, and key points of technique. The next part (Part 2) of the Guidelines will address complications and comparisons between open and laparoscopic techniques. Part 3 will cover mesh technology, hernia prophylaxis, technique-related issues, new technologic developments, lumbar and other unusual hernias, and training/education.
Guidelines are increasingly determining the decision process in day-to-day clinical work. Guidelines describe the current best possible standard in diagnostics and therapy. They should be developed by an international panel of experts, whereby alongside individual experience, above all, the results of comparative studies are decisive. According to the results of high-ranking scientific studies published in peer-reviewed journals, statements and recommendations are formulated, and these are graded strictly according to the criteria of evidence-based medicine. Guidelines can therefore be valuable in helping particularly the young surgeon in his or her day-to-day work to find the best decision for the patient when confronted with a wide and confusing range of options. However, even experienced surgeons benefit because by virtue of a heavy workload and commitment, they often find it difficult to keep up with the ever-increasing published literature. All guidelines require regular updating, usually every 3 years, in line with progress in the field. The current Guidelines focus on technique and perioperative management of laparoscopic ventral hernia repair and constitute the first comprehensive guidelines on this topic. In this issue of Surgical Endoscopy, the first part of the Guidelines is published including sections on basics, indication for surgery, perioperative management, and key points of technique. The next part (Part 2) of the Guidelines will address complications and comparisons between open and laparoscopic techniques. Part 3 will cover mesh technology, hernia prophylaxis, technique-related issues, new technologic developments, lumbar and other unusual hernias, and training/education.
Guidelines are increasingly determining the decision process in day-to-day clinical work. Guidelines describe the current best possible standard in diagnostics and therapy. They should be developed by an international panel of experts, whereby alongside individual experience, above all, the results of comparative studies are decisive. According to the results of high-ranking scientific studies published in peer-reviewed journals, statements and recommendations are formulated, and these are graded strictly according to the criteria of evidence-based medicine. Guidelines can therefore be valuable in helping particularly the young surgeon in his or her day-to-day work to find the best decision for the patient when confronted with a wide and confusing range of options. However, even experienced surgeons benefit because by virtue of a heavy workload and commitment, they often find it difficult to keep up with the ever-increasing published literature. All guidelines require regular updating, usually every 3 years, in line with progress in the field. The current Guidelines focus on technique and perioperative management of laparoscopic ventral hernia repair and constitute the first comprehensive guidelines on this topic. In this issue of Surgical Endoscopy, the first part of the Guidelines is published including sections on basics, indication for surgery, perioperative management, and key points of technique. The next part (Part 2) of the Guidelines will address complications and comparisons between open and laparoscopic techniques. Part 3 will cover mesh technology, hernia prophylaxis, technique-related issues, new technologic developments, lumbar and other unusual hernias, and training/education.
The prognosis of patients with locally advanced pancreatic cancer can be improved if secondary complete (R0) resection is possible. In patients initially staged as unresectable this may be achieved with neoadjuvant treatment which is usually chemoradiotherapy based. We report the case of a 46-year-old patient with an unresectable, locally advanced pancreatic cancer (pT4 Nx cM0 G2) who was treated with a sequential neoadjuvant chemotherapy regimen consisting of 2 cycles of nab-paclitaxel plus gemcitabine followed by 4 cycles of FOLFIRINOX. Neoadjuvant chemotherapy resulted in secondary resectability (R0 resection). After 2 cycles of nab-paclitaxel plus gemcitabine, the patient already had a complete metabolic remission as measured by integrated fludeoxyglucose ((18)F) positron emission tomography and computerized tomography. After a follow-up of 18 months the patient is alive without progression of disease. We propose to assess the clinical benefit of sequencing the combinations nab-paclitaxel plus gemcitabine and FOLFIRINOX as neoadjuvant therapy for patients with locally advanced and initially unresectable pancreatic cancer in a controlled clinical trial.
Background
Up to 50% of septic patients develop acute kidney injury (AKI). The pathomechanism of septic AKI is poorly understood. Therefore, we established an innovative rodent model to characterize sepsis-induced AKI by standardized colon ascendens stent peritonitis (sCASP). The model has a standardized focus of infection, an intensive care set up with monitoring of haemodynamics and oxygenation resulting in predictable impairment of renal function, AKI parameters as well as histopathology scoring.
Methods
Anaesthetized rats underwent the sCASP procedure, whereas sham animals were sham operated and control animals were just monitored invasively. Haemodynamic variables and blood gases were continuously measured. After 24 h, animals were reanesthetized; cardiac output (CO), inulin and PAH clearances were measured and later on kidneys were harvested; and creatinine, urea, cystatin C and neutrophil gelatinase-associated lipocalin (NGAL) were analysed. Additional sCASP-treated animals were investigated after 3 and 9 days.
Results
All sCASP-treated animals survived, whilst ubiquitous peritonitis and significantly deteriorated clinical and macrohaemodynamic sepsis signs after 24 h (MAP, CO, heart rate) were obvious. Blood analyses showed increased lactate and IL-6 levels as well as leucopenia. Urine output, inulin and PAH clearance were significantly decreased in sCASP compared to sham and control. Additionally, significant increase in cystatin C and NGAL was detected. Standard parameters like serum creatinine and urea were elevated and sCASP-induced sepsis increased significantly in a time-dependent manner. The renal histopathological score of sCASP-treated animals deteriorated after 3 and 9 days.
Conclusions
The presented sCASP method is a standardized, reliable and reproducible method to induce septic AKI. The intensive care set up, continuous macrohaemodynamic and gas exchange monitoring, low mortality rate as well as the opportunity of detailed analyses of kidney function and impairments are advantages of this setup. Thus, our described method may serve as a new standard for experimental investigations of septic AKI.
Objective: To determine whether rats reaching the same body mass, having been fed either a low-fat (LFD) or a high-fat diet (HFD), differ in white adipose tissue (WAT) deposition. Methods: In experiment 1, 22 Sprague-Dawley rats of the same age were divided into 11 rats with body mass below the batch median and fed a HFD, and 11 above the median and fed a LFD. In experiment 2, 20 Sprague-Dawley rats of the same age and starting body mass were randomised to either a HFD or LFD. When all groups reached similar final body mass, WAT was quantified using magnetic resonance imaging (MRI), dissection, and plasma leptin. Results: In experiment 1, both groups reached similar final body mass at the same age; in experiment 2 the HFD group reached similar final body mass earlier than the LFD group. There were no significant differences in WAT as assessed by MRI or leptin between the HFD and LFD groups in both experiments. Dissection revealed a trend for higher retroperitoneal and epididymal adiposity in the HFD groups in both experiments. Conclusions: We conclude that at similar body mass, adiposity is independent of the macronutrient composition of the feeding regimen used to achieve it. (C) 2014 S Karger GmbH, Freiburg
Clinical prognosis of metastasized colorectal carcinoma (CRC) is still not at desired levels and novel drugs are needed. Here, we focused on the multi-tyrosine kinase inhibitor E7080 (Lenvatinib) and assessed its therapeutic efficacy against human CRC cell lines in vitro and human CRC xenografts in vivo. The effect of E7080 on cell viability was examined on 10 humanCRCcell lines and humanendothelial cells (HUVEC). The inhibitory effect of E7080 on VEGF-induced angiogenesis was studied in an ex vivo mouse aortic ring angiogenesis assay. In addition, the efficacy of E7080 against xenografts derived fromCRC cell lines and CRC patient resection specimenswithmutated KRASwas investigated in vivo. Arelatively low cytotoxic effect of E7080 on CRC cell viabilitywas observed in vitro. Endothelial cells (HUVEC)weremore susceptible to the incubation with E7080. This is in line with the observation that E7080 demonstrated an anti-angiogenic effect in a three-dimensional ex vivo mouse aortic ring angiogenesis assay. E7080 effectively disrupted CRC cell-mediated VEGF-stimulated growth of HUVEC in vitro. Daily in vivo treatment with E7080 (5 mg/kg) significantly delayed the growth of KRAS mutated CRC xenografts with decreased density of tumor-associated vessel formations and without tumor regression. This observation is in line with results that E7080 did not significantly reduce the number of Ki67-positive cells in CRC xenografts. The results suggest antiangiogenic activity of E7080 at a dosage thatwas well tolerated by nudemice. E7080 may provide therapeutic benefits in the treatment of CRC with mutated KRAS.
Ziel der vorliegenden Arbeit war, an den sechs gastrointestinalen Karzinomzelllinien CaCo, HCT116, HT29, SW620, WiDr und 23132/87 zu untersuchen, ob Ketonkörper den Anteil vitaler Zellen durch Hemmung der Zellteilung verringern. Hierzu wurden umfangreiche In-vitro-Experimente mit unterschiedlichen Konzentrationen an Sauerstoff (21, 5 und 1 %) und D-3-Hydroxybutyrat (0,25, 4,0, 8,0 und 20 mmol/l) durchgeführt. Zusätzlich wurde überprüft, ob Ketonkörper die Glykolyse beeinflussen. Hierzu wurden der Glukoseverbrauch und die Laktatproduktion bestimmt.
Die sechs humanen gastrointestinalen Karzinomzelllinien exprimieren die zur Ketolyse notwendigen Enzyme. Die Zellen oxidieren D-3-Hydroxybutyrat zwar eindeutig bei 21 % Sauerstoff, nicht aber bei physiologischen Sauerstoffkonzentrationen von 5 % und 1 % Sauerstoff.
Die Hemmung der Zellteilung durch Ketonkörper, wurde in der vorliegenden Arbeit für keine der vier Konzentrationen an D-3-Hydroxybutyrat bei keiner der drei Konzentrationen an Sauerstoff an den untersuchten Zellen beobachtet.
Auch war keine Beeinflussung der Glykolyse durch Ketonkörper nachzuweisen. Weder der Glukoseverbrauch noch die Laktatbildung wiesen signifikante Differenzen bei Inkubation der Zellen mit D-3-Hydroxy¬butyrat auf.