Self-rated health (SRH) is associated with higher risk of death. Since low plasma levels of fat-soluble vitamins are related to mortality, we aimed to assess whether plasma concentrations of... Show moreSelf-rated health (SRH) is associated with higher risk of death. Since low plasma levels of fat-soluble vitamins are related to mortality, we aimed to assess whether plasma concentrations of vitamins A, D and E were associated with SRH in the MARK-AGE study. We included 3158 participants (52 % female) aged between 35 and 75 years. Cross-sectional data were collected via questionnaires. An enzyme immunoassay quantified 25-hydroxyvitamin D and HPLC determined alpha-tocopherol and retinol plasma concentrations. The median 25-hydroxyvitamin D and retinol concentrations differed significantly (P < 0.001) between SRH categories and were lower in the combined fair/poor category v. the excellent, very good and good categories (25-hydroxvitamin D: 40.8 v. 51.9, 49.3, 46.7 nmol/l, respectively; retinol: 1.67 v. 1.75, 1.74, 1.70 mu mol/l, respectively). Both vitamin D and retinol status were independently associated with fair/poor SRH in multiple regression analyses: adjusted OR (95 % CI) for the vitamin D insufficiency, deficiency and severe deficiency categories were 1.33 (1.06-1.68), 1.50 (1.17-1.93) and 1.83 (1.34-2.50), respectively; P = 0.015, P = 0.001 and P < 0.001, and for the second/third/fourth retinol quartiles: 1.44 (1.18-1.75), 1.57 (1. 28-1.93) and 1.49 (1.20-1.84); all P < 0.001. No significant associations were reported for a-tocopherol quartiles. Lower vitamin A and D status emerged as independent markers for fair/poor SRH. Further insights into the long-term implications of these modifiable nutrients on health status are warranted. Show less
A wide variety of animal models on thrombosis and hemostasis are used in thrombosis and hemostasis research for the preclinical assessment of hemostatic agents. While the vertebrate coagulome is... Show moreA wide variety of animal models on thrombosis and hemostasis are used in thrombosis and hemostasis research for the preclinical assessment of hemostatic agents. While the vertebrate coagulome is highly conserved, human and animal plasmas differ considerably when evaluated in coagulation assays such as prothrombin time (PT), activated partial thromboplastin time (APTT), and calibrated automated thrombography (CAT). Here, we have aimed to provide a reference framework for the evaluation of coagulation assays and inhibition of activated human FXa (hFXa) in various animal plasmas. To do so, a side-by-side evaluation of the extrinsic and intrinsic pathway of coagulation was performed by means of PT, APTT, and CAT measurements on (diluted) pooled plasmas from goats, pigs, rabbits, rats, mice, and humans. Plasma anti-FXa activity was assessed by determining the rate of recombinant hFXa inhibition through chromogenic activity analyses and immunoblotting. In general, rabbit, rat, and mouse plasmas exhibited robust clotting upon stimulation of both the extrinsic and intrinsic pathway, produced more thrombin during CAT upon plasma dilution, and displayed relatively high hFXa inhibitory activities. By comparison, goat, porcine, and human plasma displayed a similar profile in PT and APTT assays, produced less thrombin during CAT upon plasma dilution, and displayed comparable hFXa inhibitory activities. In conclusion, the observed differences in clotting parameters and anti-hFXa activity point to a higher anticoagulant threshold in plasma from rabbits, rats, and particularly in mice relative to human, goat, and porcine plasma. Finally, rat plasma was found to be more relevant to the preclinical assessment of human FX(a) in comparison to murine plasma. Show less
In this thesis, methods were developed, and antibody glycosylation was characterized in order to further the clinical application of antibody glycosylation analysis. New mass spectrometric... Show moreIn this thesis, methods were developed, and antibody glycosylation was characterized in order to further the clinical application of antibody glycosylation analysis. New mass spectrometric workflows were introduced in Chapters 2 and 8. Chapter 7 showed the differential characteristics of murine IgG glycosylation of different strains and highlighted the profound differences between humans and mice, with regard to IgG glycosylation. Chapters 4 and 8 showed the use of controlled human situations to study the regulatory mechanisms of IgG and IgA glycosylation. Finally, Chapters 3, 5 and 6, identified glycosidic differences with specified (patho)physiological conditions, which might be exploited for patient stratification in the future. Show less
In this thesis novel transmitter designs for human magnetic resonance imaging for high static magnetic field strengths (7 Tesla) were developed. The theory for both dielectric resonators as well as... Show moreIn this thesis novel transmitter designs for human magnetic resonance imaging for high static magnetic field strengths (7 Tesla) were developed. The theory for both dielectric resonators as well as plasma based resonators have been described in the introduction and outline. It was shown that by using empirically derived formulas and computer simulations dielectric resonators can be designed also by using water as a dielectric (chapter 2). In chapter 3 it was shown that alternative dielectric materials, especially high dielectric materials can be used instead of water. Chapter 4 shows the advanced usage of the technology developed in chapter 2 and chapter 3. Here an array for human cardiac magnetic resonance imaging at 7 Tesla field strength was designed and constructed. In chapter 5 a first practical design for a plasma based transmit coil for magnetic resonance imaging was demonstrated. It was shown that it is possible to guide a surface wave via the plasma sheath within the magnetic resonance imaging system. The thesis ends with chapter 6 a general discussion and an outlook to possible future developments. Show less
Verhoeven, A.; Slagboom, E.; Wuhrer, M.; Giera, M.; Mayboroda, O.A. 2017
Murine zymosan-induced peritonitis is a widely used model for studying the molecular and cellular events responsible for the initiation, persistence and/or resolution of inflammation. Among these... Show moreMurine zymosan-induced peritonitis is a widely used model for studying the molecular and cellular events responsible for the initiation, persistence and/or resolution of inflammation. Among these events, it is becoming increasingly evident that changes in glycosylation of proteins, especially in the plasma and at the site of inflammation, play an important role in the inflammatory response. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based glycosylation profiling, we investigated the qualitative and quantitative effect of zymosan-induced peritonitis on N-glycosylation in mouse plasma and peritoneal fluid. Our results show that both N-glycomes exhibit highly similar glycosylation patterns, consisting mainly of diantennary and triantennary complex type N-glycans with high levels (> 95 %) of galactosylation and sialylation (mostly NeuGc) and a medium degree of core fucosylation (30 %). Moreover, MS/MS structural analysis, assisted by linkage-specific derivatization of sialic acids, revealed the presence of O-acetylated sialic acids as well as disialylated antennae ("branching sialylation") characterized by the presence of alpha 2-6-linked NeuGc on the GlcNAc of the NeuGc alpha 2-3-Gal beta 1-3-GlcNAc terminal motif. A significant decrease of (core) fucosylation together with an increase of both alpha 2-3-linked NeuGc and "branching sialylation" were observed in N-glycomes of mice challenged with zymosan, but not in control mice injected with PBS. Importantly, substantial changes in glycosylation were already observed 12 h after induction of peritonitis, thereby demonstrating an unexpected velocity of the biological mechanisms involved. Show less
Glycosylation is the most abundant and complex protein modification, and can have a profound structural and functional effect on the conjugate. The oligosaccharide fraction is recognized to be... Show moreGlycosylation is the most abundant and complex protein modification, and can have a profound structural and functional effect on the conjugate. The oligosaccharide fraction is recognized to be involved in multiple biological processes, and to affect proteins physical properties, and has consequentially been labeled a critical quality attribute of biopharmaceuticals. Additionally, due to recent advances in analytical methods and analysis software, glycosylation is targeted in the search for disease biomarkers for early diagnosis and patient stratification. Biofluids such as saliva, serum or plasma are of great use in this regard, as they are easily accessible and can provide relevant glycosylation information. Thus, as the assessment of protein glycosylation is becoming a major element in clinical and biopharmaceutical research, this review aims to convey the current state of knowledge on the N-glycosylation of the major plasma glycoproteins alpha-1-acid glycoprotein, alpha-1-antitrypsin, alpha-1B-glycoprotein, alpha-2-HS-glycoprotein, alpha-2-macroglobulin, antithrombin-III, apolipoprotein B-100, apolipoprotein D, apolipoprotein F, beta-2-glycoprotein 1, ceruloplasmin, fibrinogen, immunoglobulin (Ig) A, IgG, IgM, haptoglobin, hemopexin, histidine-rich glycoprotein, kininogen-1, serotransferrin, vitronectin, and zinc-alpha-2-glycoprotein. In addition, the less abundant immunoglobulins D and E are included because of their major relevance in immunology and biopharmaceutical research. Where available, the glycosylation is described in a site-specific manner. In the discussion, we put the glycosylation of individual proteins into perspective and speculate how the individual proteins may contribute to a total plasma N-glycosylation profile determined at the released glycan level. Show less
Current prenatal diagnostics is mainly based on obtaining fetal DNA through invasive procedures such as chorionic villi sampling (CVS) or amniocentesis. These procedures are associated with a small... Show moreCurrent prenatal diagnostics is mainly based on obtaining fetal DNA through invasive procedures such as chorionic villi sampling (CVS) or amniocentesis. These procedures are associated with a small, but significant risk of fetal loss. The discovery of the presence of cell-free fetal DNA (cffDNA) in maternal plasma opened possibilities for less of noninvasive alternative procedures. CffDNA is comprised of small fragments of fetal extracellular DNA derived from placental cells that go into apoptosis and can be detected already early in gestation. However, the majority of total cell-free DNA in maternal plasma is of maternal origin and the fetal contribution in the first trimester is relatively small. In this thesis, we describe novel applications and approaches for the use of cffDNA in noninvasive prenatal testing and diagnostics for a wide variaty of genetics defects such as fetal trisomy 21 (Down syndrome), hereditary breast cancer mutation detection and noninvasive detection of the expanded CAG repeat in Huntington disease. Show less
In the Netherlands 1 of 1.000 inhibitants undergo cardiac surgery annually. To compensate blood loss these patients receive often blood transfusions, which can cause unexpected adverse reactions.... Show moreIn the Netherlands 1 of 1.000 inhibitants undergo cardiac surgery annually. To compensate blood loss these patients receive often blood transfusions, which can cause unexpected adverse reactions. Allogeneic leukocytes may play a prominent role in the development of these adverse reactions. We found in a randomized trial in cardiac valve surgery that patients receiving buffy-coat depleted (which contain 20-30% donor leukocytes) red blood cell (RBC) transfusions had dose-dependently higher hospital-mortality and postoperative infections than patients receiving leukocyte-depleted RBCs. Cost-effectiveness analysis revealed that leukodepletion of RBCs reduces the costs after cardiac valve surgery. Additional analyses revealed that plasma transfusions were associated with mortality and platelet transfusions with postoperative infections and longer ICU-stay. Patients who received more than 3 red blood cell units had significantly higher cytokine IL-6 concentrations after leukocyte-containing, buffy-coat depleted red blood cells (RBC) as compared to patients who had received similar numbers of leukocyte-depleted RBC units. Patients who developed postoperative infections and multiple-organ-dysfunction-syndrome showed, respectively, increased concentrations of cytokines IL-6 and IL-12 in the group that received leukocyte-containing RBCs. This laboratory analysis suggests that buffy-coat depleted erythrocytes may affect the development of postoperative complications by modulation of the postoperative proinflammatory response after cardiac surgery. Show less
Markers for longevity, which reflect the health condition and predict healthspan are extremely scarce. Such markers are, however, valuable in aging research. Protein N-glycosylation is an important... Show moreMarkers for longevity, which reflect the health condition and predict healthspan are extremely scarce. Such markers are, however, valuable in aging research. Protein N-glycosylation is an important post-translational modification, which has been shown to be altered in several pathological conditions. N-glycosylation patters therefore reflect an individual__s health state, and have therefore the potential to become candidate biomarkers for healthspan. To investigate familial longevity, large sample cohorts are necessary, and since no high-throughput analysis methods were available to facilitate Large scale N-glycan analysis, several methods, comprising HPLC-FL, CGE-LIF and MALDI-MS have been developed. These methods were applied to samples from the Leiden Longevity Study. Several changes in N-glycosylation patterns associated with familial longevity were observed in this thesis. As the predictive value of these markers is rather low, it has to be concluded that multiple markers are needed for the prediction of complex phenotypes like familial longevity. It is anticipated that __ apart from allowing more detailed insight in the processes underlying aging and longevity- the developed methodology will as well be of considerable value to other fields of biomedical research. Show less
