11 results on '"Ramaekers M"'
Search Results
2. Flow patterns in ascending aortic aneurysms: Determining the role of hypertension using phase contrast magnetic resonance and computational fluid dynamics
- Author
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Ramaekers, M. J.F.G. (author), van der Vlugt, I.B. (author), Westenberg, J. J.M. (author), Perinajová, R. (author), Lamb, H. J. (author), Wildberger, J. E. (author), Kenjeres, S. (author), Schalla, S. (author), Ramaekers, M. J.F.G. (author), van der Vlugt, I.B. (author), Westenberg, J. J.M. (author), Perinajová, R. (author), Lamb, H. J. (author), Wildberger, J. E. (author), Kenjeres, S. (author), and Schalla, S. (author)
- Abstract
Thoracic aortic aneurysm (TAA) is a local dilation of the thoracic aorta. Although universally used, aneurysm diameter alone is a poor predictor of major complications such as rupture. There is a need for better biomarkers for risk assessment that also reflect the aberrant flow patterns found in TAAs. Furthermore, hypertension is often present in TAA patients and may play a role in progression of aneurysm. The exact relation between TAAs and hypertension is poorly understood. This study aims to create a numerical model of hypertension in the aorta by using computational fluid dynamics. First, a normotensive state was simulated in which flow and resistance were kept unaltered. Second, a hypertensive state was modeled in which blood inflow was increased by 30%. Third, a hypertensive state was modeled in which the proximal and peripheral resistances and capacitance parameters from the three-element Windkessel boundary condition were adjusted to mimic an increase in resistance of the rest of the cardiovascular system. One patient with degenerative TAA and one healthy control were successfully simulated at hypertensive states and were extensively analyzed. Furthermore, three additional TAA patients and controls were simulated to validate our method. Hemodynamic variables such as wall shear stress, oscillatory shear index, endothelial cell activation potential (ECAP), vorticity and helicity were studied to gain more insight on the effects of hypertension on flow patterns in TAAs. By comparing a TAA patient and a control at normotensive state at peak-systole, helicity and vorticity were found to be lower in the TAA patient throughout the entire domain. No major changes in flow and flow derived quantities were observed for the TAA patient and control when resistance was increased. When flow rate was increased, regions with high ECAP values were found to reduce in TAA patients in the aneurysm region which could reduce the risk of thrombogenesis. Thus, it may be important, ChemE/Transport Phenomena, J.M. Burgers Center for Fluid Mechanics
- Published
- 2024
- Full Text
- View/download PDF
3. The molecular signature of the peripheral cannabinoid receptor 1 antagonist AM6545 in adipose, liver and muscle tissue.
- Author
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Dalle S, Schouten M, Deboutte J, de Lange E, Ramaekers M, and Koppo K
- Subjects
- Animals, Mice, Male, Phosphorylation drug effects, Muscle, Skeletal drug effects, Muscle, Skeletal metabolism, Signal Transduction drug effects, Pyrazoles pharmacology, Liver metabolism, Liver drug effects, Receptor, Cannabinoid, CB1 antagonists & inhibitors, Receptor, Cannabinoid, CB1 metabolism, Adipose Tissue drug effects, Adipose Tissue metabolism, Mice, Inbred C57BL
- Abstract
The endocannabinoid system plays an important role in the regulation of metabolism, growth and regeneration of peripheral tissues, including liver, adipose and muscle tissue. Studies in cells, rodents and humans showed that cannabinoid receptor 1 (CB
1 ) antagonist treatment is an effective strategy to improve features of metabolic health such as substrate metabolism, at least in models of metabolic dysregulation. However, acute signaling events that might induce these metabolic adaptations are not understood. It is not clear whether, and to which extent, a single treatment with a CB1 antagonist induces acute effects in peripheral, metabolic tissues. Therefore, the present study compared the phosphorylation status of signaling pathways and metabolic markers in liver, adipose and muscle tissue of mice treated with the peripherally restricted CB1 antagonist AM6545 and vehicle-treated mice. Protein kinase A phosphorylation was downregulated in white and brown adipose tissue, whereas the mitogen-activated protein kinase, phospho-extracellular signal-regulated kinase, was higher in liver, white adipose and muscle tissue of AM6545-treated mice. Additionally, Akt-mammalian target of rapamycin activation was higher in all tissues of AM6545-treated mice, whereas the phosphorylation status of metabolic markers remained unaffected. These data indicate that acute CB1 antagonism is effective to induce phosphorylation events of signaling cascades and metabolic markers in metabolic tissues of healthy, lean mice within a 90-min time window. The observed adaptations to AM6545 treatment do not fully align with earlier in vitro and in vivo findings, which could be ascribed to differences in cell type, exposure intensity (dose and time), health status and species., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
4. Palmitoylethanolamide Does Not Affect Recovery from Exercise-Induced Muscle Damage in Healthy Males.
- Author
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Schouten M, Dalle S, Costamagna D, Ramaekers M, Bogaerts S, Van Thienen R, Peers K, Thomis M, and Koppo K
- Abstract
Introduction: Strenuous eccentric exercise (EE) induces microstructural muscle damage, which decreases muscle performance. Palmitoylethanolamide (PEA) exerts analgesic and anti-inflammatory effects in clinical pain conditions and preclinical models of experimentally induced-inflammation. This might hold clues for improved recovery from EE. Therefore, the current study evaluates the effect of PEA supplementation on functional and molecular responses to a single EE bout., Methods: Eleven healthy male participants were included in a double-blind crossover study in which they received PEA (350 mg Levagen+) or placebo (maltodextrin) supplements, in a randomized order. In each experimental condition participants performed an acute bout of EE (24x10 eccentric contractions of the knee extensors on an isokinetic dynamometer). At baseline, 24 (D1), 48 (D2), 72 (D3) and 120 h (D5) following EE, maximal voluntary contraction and jump height were measured. Blood samples were collected at baseline and on D1-D5, and muscle biopsies were collected at baseline and on D2. Perceived muscle soreness, sleep quality and food intake were recorded daily., Results: Muscle strength and jump height decreased following EE (up to ~40 and ~ 17% respectively; Ptime < 0.05) in both conditions. This drop was accompanied by an increase in plasma creatine kinase and perceived muscle soreness (Ptime < 0.05). Furthermore, EE, but not PEA, increased the expression of the myogenic marker Pax7 and of the catabolic markers p-FoxO1-3a, p62 and LC3BII/I (Ptime < 0.05)., Conclusions: PEA supplementation does not improve muscle soreness, muscle strength and jump performance following a single EE bout. Additionally, PEA supplementation had no effect on local or systemic markers of muscle damage, catabolism or regeneration., Competing Interests: Conflict of Interest and Funding Source: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be a potential conflict of interest. This study was supported by Research Foundation Flanders (PhD fellowship 11PRA24N to MS; postdoctoral fellowship 12Z8622N to SD)., (Copyright © 2024 by the American College of Sports Medicine.)
- Published
- 2024
- Full Text
- View/download PDF
5. Improved Pancreatic Cancer Detection and Localization on CT Scans: A Computer-Aided Detection Model Utilizing Secondary Features.
- Author
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Ramaekers M, Viviers CGA, Hellström TAE, Ewals LJS, Tasios N, Jacobs I, Nederend J, Sommen FV, and Luyer MDP
- Abstract
The early detection of pancreatic ductal adenocarcinoma (PDAC) is essential for optimal treatment of pancreatic cancer patients. We propose a tumor detection framework to improve the detection of pancreatic head tumors on CT scans. In this retrospective research study, CT images of 99 patients with pancreatic head cancer and 98 control cases from the Catharina Hospital Eindhoven were collected. A multi-stage 3D U-Net-based approach was used for PDAC detection including clinically significant secondary features such as pancreatic duct and common bile duct dilation. The developed algorithm was evaluated using a local test set comprising 59 CT scans. The model was externally validated in 28 pancreatic cancer cases of a publicly available medical decathlon dataset. The tumor detection framework achieved a sensitivity of 0.97 and a specificity of 1.00, with an area under the receiver operating curve (AUROC) of 0.99, in detecting pancreatic head cancer in the local test set. In the external test set, we obtained similar results, with a sensitivity of 1.00. The model provided the tumor location with acceptable accuracy obtaining a DICE Similarity Coefficient (DSC) of 0.37. This study shows that a tumor detection framework utilizing CT scans and secondary signs of pancreatic cancer can detect pancreatic tumors with high accuracy.
- Published
- 2024
- Full Text
- View/download PDF
6. Flow patterns in ascending aortic aneurysms: Determining the role of hypertension using phase contrast magnetic resonance and computational fluid dynamics.
- Author
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Ramaekers MJFG, van der Vlugt IB, Westenberg JJM, Perinajová R, Lamb HJ, Wildberger JE, Kenjereš S, and Schalla S
- Subjects
- Humans, Hydrodynamics, Hemodynamics physiology, Magnetic Resonance Spectroscopy, Aneurysm, Ascending Aorta, Aortic Aneurysm, Thoracic diagnostic imaging, Hypertension
- Abstract
Thoracic aortic aneurysm (TAA) is a local dilation of the thoracic aorta. Although universally used, aneurysm diameter alone is a poor predictor of major complications such as rupture. There is a need for better biomarkers for risk assessment that also reflect the aberrant flow patterns found in TAAs. Furthermore, hypertension is often present in TAA patients and may play a role in progression of aneurysm. The exact relation between TAAs and hypertension is poorly understood. This study aims to create a numerical model of hypertension in the aorta by using computational fluid dynamics. First, a normotensive state was simulated in which flow and resistance were kept unaltered. Second, a hypertensive state was modeled in which blood inflow was increased by 30%. Third, a hypertensive state was modeled in which the proximal and peripheral resistances and capacitance parameters from the three-element Windkessel boundary condition were adjusted to mimic an increase in resistance of the rest of the cardiovascular system. One patient with degenerative TAA and one healthy control were successfully simulated at hypertensive states and were extensively analyzed. Furthermore, three additional TAA patients and controls were simulated to validate our method. Hemodynamic variables such as wall shear stress, oscillatory shear index, endothelial cell activation potential (ECAP), vorticity and helicity were studied to gain more insight on the effects of hypertension on flow patterns in TAAs. By comparing a TAA patient and a control at normotensive state at peak-systole, helicity and vorticity were found to be lower in the TAA patient throughout the entire domain. No major changes in flow and flow derived quantities were observed for the TAA patient and control when resistance was increased. When flow rate was increased, regions with high ECAP values were found to reduce in TAA patients in the aneurysm region which could reduce the risk of thrombogenesis. Thus, it may be important to assess cardiac output in patients with TAA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
7. Pain and Opioid Consumption After Laparoscopic Versus Open Gastrectomy for Gastric Cancer: A Secondary Analysis of a Multicenter Randomized Clinical Trial (LOGICA-Trial).
- Author
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van der Veen A, Ramaekers M, Marsman M, Brenkman HJF, Seesing MFJ, Luyer MDP, Nieuwenhuijzen GAP, Stoot JHMB, Tegels JJW, Wijnhoven BPL, de Steur WO, Kouwenhoven EA, Wassenaar EB, Draaisma WA, Gisbertz SS, van der Peet DL, May AM, Ruurda JP, and van Hillegersberg R
- Subjects
- Humans, Analgesics, Opioid therapeutic use, Pain, Postoperative drug therapy, Pain, Postoperative etiology, Gastrectomy adverse effects, Stomach Neoplasms surgery, Stomach Neoplasms drug therapy, Laparoscopy
- Abstract
Background: Laparoscopic gastrectomy could reduce pain and opioid consumption, compared to open gastrectomy. However, it is difficult to judge the clinical relevance of this reduction, since these outcomes are reported in few randomized trials and in limited detail., Methods: This secondary analysis of a multicenter randomized trial compared laparoscopic versus open gastrectomy for resectable gastric adenocarcinoma (cT1-4aN0-3bM0). Postoperative pain was analyzed by opioid consumption in oral morphine equivalents (OME, mg/day) at postoperative day (POD) 1-5, WHO analgesic steps, and Numeric Rating Scales (NRS, 0-10) at POD 1-10 and discharge. Regression and mixed model analyses were performed, with and without correction for epidural analgesia., Results: Between 2015 and 2018, 115 patients in the laparoscopic group and 110 in the open group underwent surgery. Some 16 patients (14%) in the laparoscopic group and 73 patients (66%) in the open group received epidural analgesia. At POD 1-3, mean opioid consumption was 131, 118, and 53 mg OME lower in the laparoscopic group, compared to the open group, respectively (all p < 0.001). After correcting for epidural analgesia, these differences remained significant at POD 1-2 (47 mg OME, p = 0.002 and 69 mg OME, p < 0.001, respectively). At discharge, 27% of patients in the laparoscopic group and 43% patients in the open group used oral opioids (p = 0.006). Mean highest daily pain scores were between 2 and 4 at all PODs, < 2 at discharge, and did not relevantly differ between treatment arms., Conclusion: In this multicenter randomized trial, postoperative pain was comparable between laparoscopic and open gastrectomy. After laparoscopic gastrectomy, this was generally achieved without epidural analgesia and with fewer opioids., Trial Registration: NCT02248519., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
8. Long-term Outcomes After Laparoscopic, Robotic, and Open Pancreatoduodenectomy for Distal Cholangiocarcinoma: An International Propensity Score-matched Cohort Study.
- Author
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Uijterwijk BA, Lemmers DHL, Bolm L, Luyer M, Koh YX, Mazzola M, Webber L, Kazemier G, Bannone E, Ramaekers M, Ielpo B, Wellner U, Koek S, Giani A, Besselink MG, and Abu Hilal M
- Subjects
- Humans, Cohort Studies, Pancreaticoduodenectomy, Propensity Score, Length of Stay, Bile Ducts, Intrahepatic surgery, Postoperative Complications epidemiology, Postoperative Complications surgery, Retrospective Studies, Robotic Surgical Procedures, Cholangiocarcinoma surgery, Laparoscopy, Bile Duct Neoplasms surgery, Pancreatic Neoplasms surgery
- Abstract
Objective: This study aimed to compare surgical and oncological outcomes after minimally invasive pancreatoduodenectomy (MIPD) versus open pancreatoduodenectomy (OPD) for distal cholangiocarcinoma (dCCA)., Background: A dCCA might be a good indication for MIPD, as it is often diagnosed as primary resectable disease. However, multicenter series on MIPD for dCCA are lacking., Methods: This is an international multicenter propensity score-matched cohort study including patients after MIPD or OPD for dCCA in 8 centers from 5 countries (2010-2021). Primary outcomes included overall survival (OS) and disease-free interval (DFI). Secondary outcomes included perioperative and postoperative complications and predictors for OS or DFI. Subgroup analyses included robotic pancreatoduodenectomy (RPD) and laparoscopic pancreatoduodenectomy (LPD)., Results: Overall, 478 patients after pancreatoduodenectomy for dCCA were included of which 97 after MIPD (37 RPD, 60 LPD) and 381 after OPD. MIPD was associated with less blood loss (300 vs 420 mL, P =0.025), longer operation time (453 vs 340 min; P <0.001), and less surgical site infections (7.8% vs 19.3%; P =0.042) compared with OPD. The median OS (30 vs 25 mo) and DFI (29 vs 18) for MIPD did not differ significantly between MIPD and OPD. Tumor stage (Hazard ratio: 2.939, P <0.001) and administration of adjuvant chemotherapy (Hazard ratio: 0.640, P =0.033) were individual predictors for OS. RPD was associated with a higher lymph node yield (18.0 vs 13.5; P =0.008) and less major morbidity (Clavien-Dindo 3b-5; 8.1% vs 32.1%; P =0.005) compared with LPD., Discussion: Both surgical and oncological outcomes of MIPD for dCCA are acceptable as compared with OPD. Surgical outcomes seem to favor RPD as compared with LPD but more data are needed. Randomized controlled trials should be performed to confirm these findings., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
9. Computer-Aided Detection for Pancreatic Cancer Diagnosis: Radiological Challenges and Future Directions.
- Author
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Ramaekers M, Viviers CGA, Janssen BV, Hellström TAE, Ewals L, van der Wulp K, Nederend J, Jacobs I, Pluyter JR, Mavroeidis D, van der Sommen F, Besselink MG, and Luyer MDP
- Abstract
Radiological imaging plays a crucial role in the detection and treatment of pancreatic ductal adenocarcinoma (PDAC). However, there are several challenges associated with the use of these techniques in daily clinical practice. Determination of the presence or absence of cancer using radiological imaging is difficult and requires specific expertise, especially after neoadjuvant therapy. Early detection and characterization of tumors would potentially increase the number of patients who are eligible for curative treatment. Over the last decades, artificial intelligence (AI)-based computer-aided detection (CAD) has rapidly evolved as a means for improving the radiological detection of cancer and the assessment of the extent of disease. Although the results of AI applications seem promising, widespread adoption in clinical practice has not taken place. This narrative review provides an overview of current radiological CAD systems in pancreatic cancer, highlights challenges that are pertinent to clinical practice, and discusses potential solutions for these challenges.
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- 2023
- Full Text
- View/download PDF
10. The cannabinoid receptor 1 antagonist AM6545 stimulates the Akt-mTOR axis and in vivo muscle protein synthesis in a dexamethasone-induced muscle atrophy model.
- Author
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Dalle S, Schouten M, Ramaekers M, and Koppo K
- Subjects
- Mice, Animals, TOR Serine-Threonine Kinases metabolism, Muscular Atrophy pathology, Muscle, Skeletal metabolism, Receptors, Cannabinoid metabolism, Dexamethasone pharmacology, Receptor, Cannabinoid, CB1 genetics, Receptor, Cannabinoid, CB1 metabolism, Proto-Oncogene Proteins c-akt metabolism, Muscle Proteins metabolism
- Abstract
Cannabinoid receptor 1 (CB
1 ) antagonists were shown to stimulate in vitro muscle protein synthesis, but this has never been confirmed in vivo. Therefore, this study investigated whether treatment with the CB1 antagonist AM6545 upregulates in vivo muscle anabolism. Chronic AM6545 treatment stimulated the Akt-mTOR axis and protein synthesis (+22%; p = 0.002) in the Tibialis Anterior, which protected mice from dexamethasone-induced muscle loss (-1% vs. -6% compared to healthy controls; p = 0.02). Accordingly, acute AM6545 treatment stimulated protein synthesis (+44%; p = 0.04) in the Tibialis Anterior but not Soleus. The anabolic upregulation was accompanied by ERK1/2 activation, whereas protein kinase A signaling remained unaffected, suggesting a CB1 -independent mechanism. The present study for the first time shows that the CB1 antagonist AM6545 can upregulate the Akt-mTOR axis and in vivo muscle protein synthesis. However, future work applying genetic approaches should further uncover the signaling pathways via which AM6545 enhances muscle anabolism., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2023 Elsevier B.V. All rights reserved.)- Published
- 2023
- Full Text
- View/download PDF
11. Effectief rookstopprogramma in Almere.
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Kramer I, de Voer N, Croes E, Ramaekers M, and Brouwer M
- Published
- 2023
- Full Text
- View/download PDF
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