In this thesis the development of a pathophysiology-based method for the early evaluation of anthracycline-induced cardiotoxicity was described. We evaluated a comprehensive array of biomarkers,... Show moreIn this thesis the development of a pathophysiology-based method for the early evaluation of anthracycline-induced cardiotoxicity was described. We evaluated a comprehensive array of biomarkers, representing several aspects of anthracycline-induced cardiotoxicity, including cardiac injury and remodeling, free radical overload and the inflammation accompanying the injury. It was shown that predominantly the markers of cardiac injury may be suitable for the early detection of anthracycline-induced cardiotoxicity. In the second part of this thesis we evaluated a new, free-radical scavenging compound against anthracycline-induced cardiotoxicity using this approach. The failure of this compound to show efficacy against anthracycline-induced cardiotoxicity in our model suggests that a broader approach toward the mechanism of anthracycline-induced cardiotoxicity is necessary Show less
Hooij, A. van; Eeden, S. van den; Richardus, R.; Fat, E.T.K.; Wilson, L.; Franken, K.L.M.C.; ... ; Geluk, A. 2019
Pulmonary function tests (PFTs) play an important role in screening and following-up pulmonary involvement in systemic sclerosis (SSc). However, some patients are not able to perform PFTs due to... Show morePulmonary function tests (PFTs) play an important role in screening and following-up pulmonary involvement in systemic sclerosis (SSc). However, some patients are not able to perform PFTs due to contraindications. In addition, it is unclear how lung function is affected by changes in lung structure in SSc. Therefore, this study aims to explore the potential of automatically estimating PFT results from chest CT scans of SSc patients and how different regions influence the estimation of PFTs. Deep regression networks were developed with transfer learning to estimate PFTs from 316 SSc patients. Segmented lungs and vessels were used to mask the CT images to train the network with different inputs: from entire CT scan, lungs-only to vessels-only. The network trained on entire CT scans with transfer learning achieved an ICC of 0.71, 0.76, 0.80, and 0.81 for the estimation of DLCO, FEV1, FVC and TLC, respectively. The performance of the networks gradually decreased when trained on data from lungs-only and vessels-only. Regression attention maps showed that regions close to large vessels were highlighted more than other regions, and occasionally regions outside the lungs were highlighted. These experiments show that apart from the lungs and large vessels, other regions contribute to PFT estimation. In addition, adding manually designed biomarkers increased the correlation (R) from 0.75, 0.74, 0.82, and 0.83 to 0.81, 0.83, 0.88, and 0.90, respectively. This suggests that that manually designed imaging biomarkers can still contribute to explaining the relation between lung function and structure. Show less
The main objective of the research described in this thesis is to demonstrate the relevance of biomarkers on the selection of the dose range of COX inhibitors for effective analgesic and anti... Show moreThe main objective of the research described in this thesis is to demonstrate the relevance of biomarkers on the selection of the dose range of COX inhibitors for effective analgesic and anti-inflammatory response, as opposed to the focus on behavioural measures of pain and inflammation advocated by the current paradigm for the development of non-steroidal anti-inflammatory drugs (NSAIDs). To this end, the relationship between drug concentration and the corresponding inhibition of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) was investigated for a range of COX inhibitors with varying degrees of selectivity, and hence with differential effects on the selected biomarkers. Thanks to the use of a mechanism-based approach, attention is also given to translational pharmacology in drug development. We evaluate whether 1) estimates of drug action in vitro are predictive of the effect in vivo, 2) animal data in vivo reflect drug effect on biomarkers in humans and 3) whether inflammatory conditions modify the extent of drug effect as compared to healthy conditions. A recommendation and guideline for best practices in the development of COX inhibitors is anticipated from this analysis. Show less
Stalenhoef, J.E.; Nieuwkoop, C. van; Wilson, D.C.; Starre, W.E. van der; Delfos, N.M.; Leyten, E.M.S.; ... ; Dissel, J.T. van 2018
Potential relevant biomarkers can be found at different levels in tumour developmentand disease progression. This thesis is divided into three overarching parts. Colorectalcancer was studied from... Show morePotential relevant biomarkers can be found at different levels in tumour developmentand disease progression. This thesis is divided into three overarching parts. Colorectalcancer was studied from a population-based perspective (part I) to a molecular level,detailed as protein expression (part II) and (epi)genetics (part III), as indicated in Figure 2.In part I the use of adjuvant chemotherapy in patients with locally advanced rectalcancer, who underwent resection after preoperative (chemo)radiotherapy, wasevaluated in a meta-analysis based on individual patient data. Since four randomizedcontrolled trials individually did not end the ongoing debate about the role of adjuvantchemotherapy 14,68-70. In part II the ability by tumour cells to evade the immunerecognition was studied, especially the role of the non-classical HLA class I moleculeHLA-G was studied in detail. In part III, an epigenetic biomarker, LINE-1 methylationlevel, was studied in a dedicated stage II colon cohort. In addition, an establishedgenetic biomarker for colon cancer, MSI, was studied in a large rectal cancer cohort. Show less
The main objective of this thesis is to provide a conceptual framework for the use of Central Nervous System (CNS) biomarkers in early phase clinical drug development. In the Introduction the... Show moreThe main objective of this thesis is to provide a conceptual framework for the use of Central Nervous System (CNS) biomarkers in early phase clinical drug development. In the Introduction the current use of biomarkers in early CNS drug development is discussed. A conceptual framework for the classification of biomarkers is suggested, based on general questions that these markers should provide information on. The body of this thesis (Chapters 1-7) exemplifies the use of these markers within this conceptual framework. In the Conclusions and Discussion a critical evaluation of the presented conceptual biomarker framework is give and directions for future biomarker research are offered. Show less
The work described in this thesis presents part of a framework that can be used to extract detailed disease biological information from peripheral tissue. This framework is based on the... Show moreThe work described in this thesis presents part of a framework that can be used to extract detailed disease biological information from peripheral tissue. This framework is based on the central dogma of biology “DNA to RNA to protein” and on a systems biology approach that aims to produce synergetic data whose disease pathological, prognostic and predictive value is greater than the sum of the individual experiment results. HD patients are often characterized by a multifaceted clinical profile, consisting of several symptoms and variable disease progression rates. Therefore, a systems approach such as the one described above is expected to be the most effective in identifying potential treatments and predictive biomarkers that will be most informative for the different patient subpopulations. Show less
Background: Serum biomarkers may inform and improve care in traumatic brain injury (TBI). We aimed to correlate serum biomarkers with clinical severity, care path and imaging abnormalities in TBI,... Show moreBackground: Serum biomarkers may inform and improve care in traumatic brain injury (TBI). We aimed to correlate serum biomarkers with clinical severity, care path and imaging abnormalities in TBI, and explore their incremental value over clinical characteristics in predicting computed tomographic (CT) abnormalities.Methods: We analyzed six serum biomarkers (S100B, NSE, GFAP, UCH-L1, NFL and t-tau) obtained <24 h post-injury from 2867 patients with any severity of TBI in the Collaborative European NeuroTrauma Effectiveness Research (CENTER-TBI) Core Study, a prospective, multicenter, cohort study. Univariable and multivariable logistic regression analyses were performed. Discrimination was assessed by the area under the receiver operating characteristic curve (AUC) with 95% confidence intervals.Findings: All biomarkers scaled with clinical severity and care path (ER only, ward admission, or ICU), and with presence of CT abnormalities. GFAP achieved the highest discrimination for predicting CT abnormalities (AUC 0.89 [95%CI: 0.87-0.90]), with a 99% likelihood of better discriminating CT-positive patients than clinical characteristics used in contemporary decision rules. In patients with mild TBI, GFAP also showed incremental diagnostic value: discrimination increased from 0.84 [95%CI: 0.83-0.86] to 0.89 [95%CI: 0.87-0.90] when GFAP was included. Results were consistent across strata, and injury severity. Combinations of biomarkers did not improve discrimination compared to GFAP alone.Interpretation: Currently available biomarkers reflect injury severity, and serum GFAP, measured within 24 h after injury, outperforms clinical characteristics in predicting CT abnormalities. Our results support the further development of serum GFAP assays towards implementation in clinical practice, for which robust clinical assay platforms are required.(C) 2020 The Authors. Published by Elsevier B.V. Show less
Osteoarthritis (OA) is a prevalent age-related joint disease, determined by diverse changes in pathways maintaining articular cartilage and subchondral bone. This thesis aimed to identify and study... Show moreOsteoarthritis (OA) is a prevalent age-related joint disease, determined by diverse changes in pathways maintaining articular cartilage and subchondral bone. This thesis aimed to identify and study gene networks driving interacting etiopathophysiological OA processes in cartilage and subchondral bone. Hereto, characterization of the molecular landscape of bone and cartilage of OA patients showed 305 genes with similar direction of effect, including IL11 and CHADL. Moreover, to capture biological complexity and decipher underlying OA disease mechanisms a variety of human 3D cartilage and bone organoids models were exploited and a human osteochondral construct-on-a-chip was developed. Herein, we showed that the robust OA risk gene WWP2 may initiate OA, via aberrant responses in hypoxia-associated genes and a decrease in anabolic markers. Additionally we showed, as reflected by upregulation of SPP1 and downregulation of WNT16 in cartilage, that treatment of ex vivo human osteochondral explants with human recombinant IL11 does not necessarily has a beneficial outcome. Finally, to allow implementation of knowledge on diverse OA pathophysiological processes, the potency of circulating miRNAs to report on ongoing OA pathophysiological process in joint tissues was established. Such insights are crucial to stratify respective OA patients that require different therapeutic mode of action, towards precision medicine. Show less
The aim of this thesis was to study cardiovascular risk management in old age, in order to facilitate the development of age specific guidelines. In part one the current status of cardiovascular... Show moreThe aim of this thesis was to study cardiovascular risk management in old age, in order to facilitate the development of age specific guidelines. In part one the current status of cardiovascular prevention in old age is described, including a study into general practitioners__ attitudes and perceived barriers in this respect. The second part explores the incremental value of routine-ECGs for cardiovascular risk management in older persons from the general population, beyond existing information from medical records. The third part focuses on primary prevention, exploring the performance of classic risk factors, and some new biomarkers, in predicting cardiovascular mortality in very old people from the general population. It was concluded that a homocysteine level alone accurately identifies those at high risk of cardiovascular mortality, whereas classic risk factors included in the Framingham risk score do not. Next, in various age strata from age 55 years onwards, the association between blood pressure and mortality was studied. Finally, a systematic review into the diagnostic accuracy of natriuretic peptides for the diagnosis of chronic heart failure in older persons from the general population was performed, followed by a study in a cohort of nonagenarians into the prognostic value of NT-proBNP. A general discussion is provided, including directions for future research. Show less
This thesis has studied several modalities how to increase the organ utilisation rate. The results in this thesis indicate that the acceptance of kidneys with acute kidney injury stage 1 or 2 will... Show moreThis thesis has studied several modalities how to increase the organ utilisation rate. The results in this thesis indicate that the acceptance of kidneys with acute kidney injury stage 1 or 2 will significantly contribute to the donor pool as AKI kidneys have comparable outcomes and should therefore not be discarded. Clinically relevant biomarkers such as cell-free unmethylated-INS DNA, FMN, GSN, IGFBP3 and IGF2R were identified or explored in the first part of this thesis and may, if analysed and/or validated thoroughly, contribute to a better assessment of organ viability supporting the justified decision whether to accept or decline the donor organ.The second part of this thesis describes different aspects of the organ preservation technique of abdominal normothermic regional perfusion (aNRP). This relatively new machine perfusion technique has been shown to be feasible and safe, however, consensus regarding assessment parameters during perfusion, protocols and outcome measurements is still lacking. Despite of an inspiring surgical enthusiasm and keeninterest to accept this modality as a new standard, a randomised clinical trial is still required and entirely ethically justifiable in order to scientifically demonstrate superiority of this method for each individual abdominal organ comparing it to other successful (ex-situ) preservation and perfusion strategies. If aNRP can be shown to obtain better post transplantation outcomes whilst increasing organ utilisation, it may be the least complex and most cost-effective strategy in organ preservation. On the other hand, aNRP will only be used in DCD donors. As such, uncertainty regarding the quality of higher risk organs from DBD donors will still be evaluated ex-situ during cold and/or warm machine perfusion with the potential to repair or even regenerate injured organs and making them ‘transplantable’ again. Show less
Cardiovascular magnetic resonance imaging is an important noninvasive imaging modality for the diagnosis, clinical work‐up and treatment planning in patients suspected for a wide range of... Show moreCardiovascular magnetic resonance imaging is an important noninvasive imaging modality for the diagnosis, clinical work‐up and treatment planning in patients suspected for a wide range of cardiovascular pathology. CMR imaging is accurate and reliable, and provides invaluable information to evaluate the cardiovascular system without the need of ionizing radiation. The studies described in this thesis evaluate new CMR imaging techniques in clinical practice and explore the prognostic value of new CMR imaging biomarkers in patients with symptomatic peripheral arterial occlusive disease. New advances and innovations in MR imaging technology improve and further expand the clinical applications of cardiovascular imaging in daily clinical practice. In this thesis, a new, fast free‐breathing 2D delayed‐enhancement MRI sequence is validated and demonstrated to be a reliable tool for detecting myocardial infarction. Furthermore, new technical developments allow single‐injection, three‐station, moving‐table MRA protocol at 3Tesla with similar diagnostic performance when compared to 1.5Tesla. Additionally, submillimeter isotropic voxel acquisition in the lower legs at 1.5Tesla improves the diagnostic accuracy and depicts more open infragenual arterial segments.Additionally, it is demonstrated that new MRI biomarkers as distal aortic pulse wave velocity statistically significantly correlate with stenosis severity in symptomatic patients with peripheral arterial occlusive disease. Finally, we showed that CMR derived biomarkers relating to stenosis severity, aortic stiffness and left ventricular function play a role in prognosis of outcome in patients with symptomatic PAOD. In the future, incorporation of the described new MRI biomarkers in the clinical workup of peripheral arterial occlusive disease may play an important role for full vascular risk assessment and ultimately, patients may benefit in clinical practice. Show less
