Various non-invasive imaging techniques are available for the diagnosis of coronary artery disease (CAD). Multi-slice computed tomography (MSCT) is an upcoming technique that allows direct... Show moreVarious non-invasive imaging techniques are available for the diagnosis of coronary artery disease (CAD). Multi-slice computed tomography (MSCT) is an upcoming technique that allows direct visualization of the coronary arteries. Apart from the assessment of atherosclerosis, MSCT can also provide important information on the global and regional left ventricular (LV) function. However, it should be realized that the hemodynamic consequences of atherosclerosis can not be obtained by MSCT imaging, and that functional testing, with for example nuclear imaging, will remain necessary to determine therapeutic strategy. CAD is the most common cause of chronic heart failure. Recently, cardiac resynchronization therapy (CRT) has become implemented in the treatment of patients with severe heart failure. Although the improvement in systolic function after CRT implantation can be considerable, 20% to 30% of patients do not respond to CRT. It has been shown that the presence of LV dyssynchrony is an important predictor of response to CRT. Gated SPECT allows not only the assessment of myocardial perfusion (scar tissue and viable myocardium) but also the evaluation of LV dyssynchrony. As many patients with heart failure undergo nuclear imaging with SPECT, integrated assessment of LV dyssynchrony, viability and scar tissue may be an attractive option. Show less
The findings of the present thesis can be summarized in the following conclusions: 1. In Leiden, the so-called ‘founder effect’ resulted in genetic clustering with an extremely high prevalence of... Show moreThe findings of the present thesis can be summarized in the following conclusions: 1. In Leiden, the so-called ‘founder effect’ resulted in genetic clustering with an extremely high prevalence of one single SDHD mutation, the SDHD-c.274G>T (p.Asp92Tyr) mutation. 2. Patients with head-and-neck paragangliomas have a considerable impairment of quality of life. 3. Patients with head-and-neck paragangliomas have serious subjective sleep complaints. 4. Patients with SDHD-associated head-and-neck paragangliomas have an increased risk for development of pheochromocytomas and paragangliomas at other locations and life long, repetitive follow up with protocolized clinical, biochemical and radiological screening is therefore mandatory. 5. The use of [123I]-MIBG for detection of intra- and extra-adrenal paragangliomas combined, revealed a sensitivity and specificity of only 80% and 75%, respectively. The sensitivity is dependent on tumor localization and tumor behavior, with an increase in sensitivity to 92% if (intra-adrenal) pheochromocytomas are investigated separately. 6. The practical clinical implications of non-secreting intra-adrenal paragangliomas are currently uncertain. 7. Patients with SDHD mutations have malignant disease in at least ~2.5% of the cases. 8. Mediastinal paragangliomas are associated with mutations in the succinate dehydrogenase genes (either SDHB or SDHD) and aggressive behavior and might be more prevalent than hitherto appreciated. 9. Although the consequences of missing non-secreting and mediastinal paragangliomas in an SDHD-associated population are currently unclear, their possible presence should be taken into consideration in the development of future screening protocols. 10. In the future, [18F]-FDOPA and/or [18F]-FDA are expected to (at least partly) replace MIBG in diagnostic imaging for pheochromocytoma and paraganglioma. Show less
Replicative ageing of fibroblasts has often been used as a model for organismal ageing. The general assumption that the ageing process is mirrored by cellular senescence in vitro is based on lower... Show moreReplicative ageing of fibroblasts has often been used as a model for organismal ageing. The general assumption that the ageing process is mirrored by cellular senescence in vitro is based on lower replicative capacity of human fibroblasts from donors of higher chronological age, but these inverse relations have not been reported unequivocally. The relation between chronological age and fibroblast growth characteristics was assessed in nonagenarian subjects of the Leiden 85+ Study. A high remaining replicative capacity impressively showed that even in the very elderly a crucial number of cells with high mitotic capacity are left to give rise to fibroblast strains with the capacity for more than 100 population doublings. During the course of fibroblast growth in vitro, beta-galactosidase activity has been shown to be a reliable biomarker for replicative senescence. In myoblast cultures the relation between mixed cultures and clonal cultures was studied, showing marked heterogeneity between clonal cultures that all had a significantly lower replicative capacity when compared to mixed cultures, indicating heterogeneity of cells within one tissue compartment in their in vivo history. In a formal review on the replicative capacity of fibroblasts from patients suffering from accelerated ageing syndromes, age related diseases and donor age it was found that except for premature ageing syndromes, the replicative capacity of fibroblasts in vitro does not mirror key characteristics of human life histories. Show less
The initial damage recognizing complex in bacterial nucleotide excision repair consists of two UvrA and two UvrB molecules. Of these proteins UvrB is the main damage recognition protein and is... Show moreThe initial damage recognizing complex in bacterial nucleotide excision repair consists of two UvrA and two UvrB molecules. Of these proteins UvrB is the main damage recognition protein and is capable of recognizing various structurally unrelated types of damage. To do so, the protein must recognize a common alteration of the DNA structure induced by these different damages. For UvrB sterical hindrance of the present DNA modification prevents it from passing behind a _-hairpin structure present in the protein, thereby conferring damage recognition. Upon stalling of the protein at the site of damage in this way we show that two nucleotides become extrahelical: the nucleotide directly 3__ to the lesion and its base-pairing partner in the non-damaged strand. In contrast to other repair enzymes however the damaged nucleotide itself does not become extrahelical. Flipping in one of the two DNA strands has been shown to be important in preventing stable binding of the protein to undamaged DNA. Flipping in the other DNA strand however is required for efficient 3__ incision by UvrC, the nuclease of the system. A second incision at the 5__ side of the damage by the same protein facilitates removal of the damage-containing DNA oligonucleotide. Show less
The snails__ proverbial inertness makes it an ideal subject to study the patterns and processes that lead to speciation. The land snail family Chondrinidae consists of about 70 extant species in... Show moreThe snails__ proverbial inertness makes it an ideal subject to study the patterns and processes that lead to speciation. The land snail family Chondrinidae consists of about 70 extant species in six genera. They occur throughout western and central Europe, northern Africa and as far east as Pakistan. These snails share a long and interesting evolutionary history, to the knowledge of which we contribute here. Show less
This thesis focuses on bridging the gap between natural and artificial systems by the structural and structure-function characterization of two kinds of natural photosynthetic antenna systems, a... Show moreThis thesis focuses on bridging the gap between natural and artificial systems by the structural and structure-function characterization of two kinds of natural photosynthetic antenna systems, a pigment-protein complex i.e. the LH2 complex, and the protein-free chlorosome supramolecular light harvesters. Chlorosomes contain the largest numbers of chromophores for any antenna system known in nature and are very efficient ultra-fast light harvesters. They provide an optimal starting point for a novel class of artificial antenna arrays for ultra-rapid feeding of energy into photocatalytic devices. Show less
The thesis project is devoted to the __search of antineoplastic ruthenium/platinum/copper complexes containing also intercalator ligands; such intercalators may show efficient DNA-cleaving and DNA... Show moreThe thesis project is devoted to the __search of antineoplastic ruthenium/platinum/copper complexes containing also intercalator ligands; such intercalators may show efficient DNA-cleaving and DNA-binding properties__. The studies have been carried out using a variety of techniques. Study of the in vitro cytotoxicity against human tumour cell lines along with cellular uptake has been the pivotal point of this research. Synthetic methodologies of the new complexes have been designed to establish structure-activity relation in several series of related complexes. Platinum complexes of derivatized-phenanthroline, pyridine and pyrimidine, have been synthesized and studied in detail for their biological activity. These complexes are different in structure and in overall charges, and were studied to elucidate the effects on the activity profile. A self-activating copper-complex formed from a unique amino-phenol ligand (Hpyramol) inspired the synthesis of platinum and ruthenium analogues. Biological studies including cellular uptake, conformational changes (CD and UV) and DNA cleavage have been performed to interpret the changes in activity profile upon various metal additions. Ruthenium complexes are known as suitable candidates for anticancer (specially as antimetastatic drugs) agents. A group of ruthenium(III) complexes has been studied for their anticancer activity and their DNA-binding properties. The extensive area of homo- or heterometallic dinuclear compounds opens up an interesting challenge towards the synthesis of complexes. The studies of different combinations viz., Ru-Ru, Cu-Cu and Pt-Pt, have been performed to design new series of anticancer complexes. Show less
This thesis discusses several aspects of therapeutic interventions for arthritis of the knee, especially arthroscopic lavage. Arthroscopic lavage is a technique in which the inflamed knee of the... Show moreThis thesis discusses several aspects of therapeutic interventions for arthritis of the knee, especially arthroscopic lavage. Arthroscopic lavage is a technique in which the inflamed knee of the patient is rinced with saline. After the procedure corticosteroids can be administered to suppress inflammation. Arthroscopic lavage was superior in suppressing recurrence of arthritis compared to standard joint injections with corticosteroids. The occurence of fibrosis in the inflamed joint was predictive of an inferior response. During arthroscopic lavage synovial tissue samples can be obtained. These biopsies were studied before and after treatment with anti-TNF in longstanding and early (therapy-naieve) Rheumatoid Arthritis (RA)patients. The clinical and synovial effect were comparable between both groups. In the latter part differences in synovial inflamation between RA patients with and without antibodies against cyclic citrullinated peptides (CCP) are discussed in relation to the occurence of joint damage. In anti-CCP positive patients we found more infiltrating lymphocytes leading to progression of joint damage. Also, temporal changes in synovial inflammation differed between anti-CCP positive and anti_CCP negative RA, underlining the fenotypical differences betwen both disease entities. Show less
This thesis centers around a novel fluorescence based method that allows to monitor the activity of redox enzymes and of electron (ET) or oxygen transfer proteins. It takes advantage of the fact... Show moreThis thesis centers around a novel fluorescence based method that allows to monitor the activity of redox enzymes and of electron (ET) or oxygen transfer proteins. It takes advantage of the fact that the absorption spectrum of the protein__s active site varies upon changing its redox state. This change can be translated into a change in the fluorescence intensity of a label that is covalently linked to the protein on the basis of F_rster Resonance Energy Transfer (FRET). With our method we could show that different redox proteins and enzymes can be studied down to the single molecule level. This exciting finding opens the door to the study of various redox enzymes and to monitor specific substances such as for example nitrite. Depending on the function of the enzyme under investigation a wide range of substrates can be monitored. Another example is the development of an oxygen sensor by employing proteins that are capable of binding oxygen. The findings presented in this thesis might be significant for applications in oxygen sensing and, more generally, in the fast growing field of biosensing Show less
Nucleocytoplasmic traffic is one of the hallmarks of the eukaryotic cell. To a large extent, this process is mediated by nuclear import and export receptors. Study of nuclear import and export has... Show moreNucleocytoplasmic traffic is one of the hallmarks of the eukaryotic cell. To a large extent, this process is mediated by nuclear import and export receptors. Study of nuclear import and export has had wide implications for many cellular processes including basic cell metabolism, cellular differentiation and disease. In this thesis I have studied the nuclear export receptor CRM1/exportin1 and its interaction with various transport substrates and the nuclear pore complex (NPC), the supramolecular structure through which receptor-mediated nucleocytoplasmic transport takes place. CRM1 interacts with its substrate through the nuclear export signal (NES) and I have identified a novel type NES, the supraphysiological NES (supraNES). This is a synthetic peptide NES that binds CRM1 with an unusual high affinity. Interestingly, we found that supraNESs do not only exist as synthetic peptides, but are present in certain viruses, where they are required for export of the viral particle from the nucleus. The currently emerging supraNESs in other viruses and the hypothesis that supraNESs could be responsible for export of large cargo in general will be discussed. Show less
Endocytosis can be conceptually broken down into two stages: The formation of the nascent vesicle containing the ingested proteins and lipids, and its subsequent maturation into a degradative... Show moreEndocytosis can be conceptually broken down into two stages: The formation of the nascent vesicle containing the ingested proteins and lipids, and its subsequent maturation into a degradative compartment. During this maturation process proteins can be recycled back to the plasma membrane to prevent degradation. The vesicular membrane and the luminal contents undergo considerable remodeling to transform this compartment into a degradative one. This stops signal transduction by degrading the receptors within the vesicle and also generates antigens for presentation on MHC class II molecules in order to elicit an adaptive immune response. The engulfment of large particles and microorganisms (e.g. pathogens) is referred to as phagocytosis. The vesicle created by phagocytosis is called the phagosome. Phagosome maturation is considered to involve a complex sequence of fusion and fission events with the sub compartments of the endocytic pathway. In many ways, phagosome maturation recapitulates the progression of cargo along the endocytic pathway. In this thesis we have described molecular mechanisms that regulate the endocytic route and how pathogens explore this endocytic route to ensure survival. Show less
This thesis focuses on cellular immunity against mycobacteria during latency with the aim to contribute to improved immunodiagnosis of latent TB and to gain insight into immune responses which play... Show moreThis thesis focuses on cellular immunity against mycobacteria during latency with the aim to contribute to improved immunodiagnosis of latent TB and to gain insight into immune responses which play a role in controlling latent infection. Several new highly M. tuberculosis-specific peptides mixtures were identified to optimize the sensitivity of immunodiagnostic assays. The performance of interferon-gamma-release-assays (IGRA) for detection of latent TB were evaluated. Two short-incubation IGRA, QuantiFERON-TB Gold and T-SPOTTM.TB, were found to correlate better to the level of exposure to M. tuberculosis than the tuberculin skin test (TST), indicating that these assays are very sensitive for detection of recent infections. However, short-incubation IGRA are less sensitive than prolonged-incubation IGRA and TST for detection of latent TB acquired in the past. The search for proteins that are specifically targeted by the immune system during latency led to the identification of several antigens encoded within the DosR-regulon. This set of genes of M. tuberculosis is strongly upregulated by during in vitro models of latency. These antigens, including 16kDa _-crystallin, were preferentially recognized by latently infected individuals, which suggest that T-cell responses to latency antigens are associated with natural protection against reactivation of TB, warranting their further study as vaccine candidates. Show less
This thesis contains various studies on syncope. The first part of the thesis systematically reviews the terminology of syncope and related conditions. The second part of the thesis questions... Show moreThis thesis contains various studies on syncope. The first part of the thesis systematically reviews the terminology of syncope and related conditions. The second part of the thesis questions whether orthostatic hypotension in autonomic failure is associated with increased venous pooling upon standing. In the third part the role hyperventilation in the pathophysiology of syncope is examined. Furthermore the potential of respiratory manoeuvres to combat orthostatic hypotension in autonomic failure is evaluated. The final part of the thesis contains various clinical studies, including the assessment of the accuracy of eyewitness accounts in transient loss of consciousness. Show less
__More solid things do not show the complexion of the times so well as Ballads and Libels__. This is how the lawyer and scholar John Selden (1584__1654) described an important characteristic of the... Show more__More solid things do not show the complexion of the times so well as Ballads and Libels__. This is how the lawyer and scholar John Selden (1584__1654) described an important characteristic of the songs that he collected in printed form, the so-called broadside ballads. This study is an examination of an aspect of popular culture that reached its zenith in the mid-seventeenth century. Among the issues under discussion are the ways in which broadside ballads acted almost as a subversive subculture, with writers, engravers and printers drawing on a shared and allusive body of subject matter. Thus, while the broadside ballad may be a popular and unsophisticated form of literature, it is not a simple and straightforward song. Its message is often shaped to a considerable extent by allusions and references to other broadside ballads, and the seventeenth-century ballad audience was apparently expected t o be familiar with a wide range of ballads in order to be able to interpret the __ sometimes subversive __ references to ballad literature. Issues such as the choice of a tune, and the printers__ decisions on illustrations and layout are of great importance in this respect as they may considerably influence the message of the political broadside ballad. Show less
Cutaneous and uveal melanoma are malignant tumours with no treatment available once the metastases occur. Despite both melanomas are highly immunogenic, and often despite the presence of potent... Show moreCutaneous and uveal melanoma are malignant tumours with no treatment available once the metastases occur. Despite both melanomas are highly immunogenic, and often despite the presence of potent anti-tumour immune cells in patients__ blood, in more than 95% of patients, tumour growth remains unaffected. Hereby we investigate the mechanisms that help melanomas to escape from the spontaneous or activated by vaccination cytotoxicity of T lymphocytes and discuss the impact of local microenvironment created by melanoma, focusing on the role of immunomodulatory dendritic cells. Show less
Blood-flow-induced shear stress plays an important role in cardiovascular development and disease. How endothelial cells sense shear stress remains to be elucidated. We postulated that the primary... Show moreBlood-flow-induced shear stress plays an important role in cardiovascular development and disease. How endothelial cells sense shear stress remains to be elucidated. We postulated that the primary cilium is a component of the endothelial shear sensor. This luminal cell protrusion contains microtubules and is connected to the microtubular cytoskeleton. We identified cilia on endothelial cells of the embryonic heart in areas of low or oscillatory shear stress. This shear-related distribution is reminiscent of the distribution of atherosclerotic lesions in the adult arterial system, as lesions develop at sites of low or oscillating shear (athero-prone flow). Ciliated endothelial cells are exclusively present at these atherosclerotic predilection sites in adult mice. Athero-prone (oscillatory) but not athero-protective (steady or pulsatile) flow induces ciliation of cultured endothelial cells. Moreover, the endothelial shear response is dependent on the microtubular cytoskeleton and primary cilia sensitise the endothelium for shear. Taken together, these data demonstrate that primary cilia are induced by athero-prone flow and that ciliated cells are more sensitive to shear stress. We conclude that the endothelial biosensor for shear stress is the microtubular cytoskeleton and that the attached primary cilium functions as a signal amplifier in areas subjected to athero-prone flow. Show less
In general, biological and chemical causes for harmful effects were studied through bioinformatics and cheminformatics efforts. A database of human genetic variants in G protein-coupled receptors... Show moreIn general, biological and chemical causes for harmful effects were studied through bioinformatics and cheminformatics efforts. A database of human genetic variants in G protein-coupled receptors was constructed, and differences between neutral and harmful variants were studied. A database of compounds with their mutagenicity data was constructed, and substructures were extracted that distinguish between Ames positive and Ames negative compounds. 6. Keywords (At most 10, in English), preferably from the thesaurus in use within your discipline. Do not use very general terms. cheminformatics, chemoinformatics, bioinformatics, databases, data mining, drug discovery, SNPs, polymorphisms, substructures. Show less
Adoptive transfer of T cell immunity has been proposed as an attractive form of cancer immunotherapy in cases where the endogenous T cell repertoire is immune tolerant. In this thesis murine models... Show moreAdoptive transfer of T cell immunity has been proposed as an attractive form of cancer immunotherapy in cases where the endogenous T cell repertoire is immune tolerant. In this thesis murine models are used to study two different approaches to generate T cell grafts with defined tumor specificities. First the feasibility of minor antigen specific T cell depletion to limit the development of Graft-versus-Host Disease after allogeneic stem cell transplantation in combination with donor lymphocyte infusions is addressed. In the second part T cell receptor gene transfer is used to generate tumor specific T cells. Show less
Papyrologie is een van de zeldzame vakgebieden diesteeds nieuwe informatie aanleveren over het leven in de oudheid. Het merendeelvan de papyri die vooral in Egypte zijn teruggevonden, is geschreven... Show morePapyrologie is een van de zeldzame vakgebieden diesteeds nieuwe informatie aanleveren over het leven in de oudheid. Het merendeelvan de papyri die vooral in Egypte zijn teruggevonden, is geschreven in deGriekse taal en stamt grofweg uit de periode tussen 300 voor en 800 na Chr.Veel conclusies die op basis van deze teksten zijn getrokken, kunnen ook wordentoegepast op andere delen van de toenmalige wereld, waarvoor dit soort bronnenveelal ontbreekt. Het blijft van belang nieuwe papyri te ontcijferen,publiceren en interpreteren om conclusies die eerder zijn getrokken te toetsenaan nieuwe gegevens en om lacunes in onze kennis op te vullen. Dit proefschrift bestaat uit tien reeds gepubliceerdeartikelen waarin Griekse teksten op papyrus worden ontcijferd, vertaald enbecommentarieerd. De teksten bieden nieuwe dan wel aanvullende informatie overRomeins en Byzantijns Egypte. Ze zijn vooral juridisch enbestuurlijk/administratief van aard: het gaat om contracten (verzoening naconflict, koopcontracten van huis, land, slaaf), een correctie op de aangiftevoor een volkstelling, brieven (ambtelijk en privé: melding van hettegenhouden, door een gezant van de keizer in Constantinopel, van schepen vaneen grootgrondbezittter) en een verzoekschrift aangaande een meningsverschilover de rechten een veerdienst te onderhouden. Show less
This rich ethnographic study explores the life and work of successful marabout women in Dakar. it is set against the background of their private family lives, of developments in Senegalese society,... Show moreThis rich ethnographic study explores the life and work of successful marabout women in Dakar. it is set against the background of their private family lives, of developments in Senegalese society, and of global changes. While including female experts in spirit possession and plant-based healing, it also gives a rare insight in the work of women who offer Islamic knowledge such as Arabic astrology, numerology, divination and prayer sessions. With the analysis of marabout women's work this study sheds light on the ways in which women's authority is negotiated, legitimated, and publicly recognised in Dakar. The study focuses especially upon marabout women's strategies to gain their client's trust. Reference to rural areas is a significant element in this process. This study thus contributes to an understanding of a gendered way in which trust ans skepticism are related to marabout's work and of the the role of a connection between Dakar and the rural areas therein. Show less
