201 research outputs found

    Botpathologie bij apen van de Nieuwe en Oude Wereld

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    Primates are frequently used lab animals in biomedical research, due to their close relationship to humans. Especially, the genus Callithrix jacchus (common marmoset) and the genus Macaca mulatto (rhesus monkey) are commonly used in scientific research. In this article, a systematic overview is given of the main bone pathologies of primates. Bone pathologies may occur spontaneously, but can also be induced experimentally for research into human diseases. Knowledge about these pathologies is not only important for the prevention and treatment of human and primate bone diseases, it also contributes to choosing the correct animal models. The historically most important bone pathologies belong to the group of metabolic disorders, among which rickets/osteomalacia and osteoporosis are the best known. Congenital disorders, developmental pathologies, intoxications and deficiencies with effects on the skeleton are also discussed. Finally, bone tumors are described, which do not occur frequently, but which should not be neglected

    A Joint Pharmacokinetic Model for the Simultaneous Description of Plasma and Whole Blood Tacrolimus Concentrations in Kidney and Lung Transplant Recipients

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    BACKGROUND AND OBJECTIVE: Historically, dosing of tacrolimus is guided by therapeutic drug monitoring (TDM) of the whole blood concentration, which is strongly influenced by haematocrit. The therapeutic and adverse effects are however expected to be driven by the unbound exposure, which could be better represented by measuring plasma concentrations.OBJECTIVE: We aimed to establish plasma concentration ranges reflecting whole blood concentrations within currently used target ranges.METHODS: Plasma and whole blood tacrolimus concentrations were determined in samples of transplant recipients included in the TransplantLines Biobank and Cohort Study. Targeted whole blood trough concentrations are 4-6 ng/mL and 7-10 ng/mL for kidney and lung transplant recipients, respectively. A population pharmacokinetic model was developed using non-linear mixed-effects modelling. Simulations were performed to infer plasma concentration ranges corresponding to whole blood target ranges.RESULTS: Plasma (n = 1973) and whole blood (n = 1961) tacrolimus concentrations were determined in 1060 transplant recipients. A one-compartment model with fixed first-order absorption and estimated first-order elimination characterised observed plasma concentrations. Plasma was linked to whole blood using a saturable binding equation (maximum binding 35.7 ng/mL, 95% confidence interval (CI) 31.0-40.4 ng/mL; dissociation constant 0.24 ng/mL, 95% CI 0.19-0.29 ng/mL). Model simulations indicate that patients within the whole blood target range are expected to have plasma concentrations (95% prediction interval) of 0.06-0.26 ng/mL and 0.10-0.93 ng/mL for kidney and lung transplant recipients, respectively.CONCLUSION: Whole blood tacrolimus target ranges, currently used to guide TDM, were translated to plasma concentration ranges of 0.06-0.26 ng/mL and 0.10-0.93 ng/mL for kidney and lung transplant recipients, respectively.</p

    Epoetin Beta and C-Terminal Fibroblast Growth Factor 23 in Patients With Chronic Heart Failure and Chronic Kidney Disease

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    Background In patients with chronic heart failure and chronic kidney disease, correction of anemia with erythropoietin-stimulating agents targeting normal hemoglobin levels is associated with an increased risk of cardiovascular morbidity and mortality. Emerging data suggest a direct effect of erythropoietin on fibroblast growth factor 23 (FGF23), elevated levels of which have been associated with adverse outcomes. We investigate effects of erythropoietin-stimulating agents in patients with both chronic heart failure and chronic kidney disease focusing on FGF23. Methods and Results In the EPOCARES (Erythropoietin in CardioRenal Syndrome) study, we randomized 56 anemic patients (median age 74 [interquartile range 69-80] years, 66% male) with both chronic heart failure and chronic kidney disease into 3 groups, of which 2 received epoetin beta 50 IU/kg per week for 50 weeks, and the third group served as control. Measurements were performed at baseline and after 2, 26, and 50 weeks. Data were analyzed using linear mixed-model analysis. After 50 weeks of erythropoietin-stimulating agent treatment, hematocrit and hemoglobin levels increased. Similarly, C-terminal FGF23 levels, in contrast to intact FGF23 levels, rose significantly due to erythropoietin-stimulating agents as compared with the controls. During median follow-up for 5.7 (2.0-5.7) years, baseline C-terminal FGF23 levels were independently associated with increased risk of mortality (hazard ratio 2.20; 95% CI, 1.35-3.59; P=0.002). Conclusions Exogenous erythropoietin increases C-terminal FGF23 levels markedly over a period of 50 weeks, elevated levels of which, even at baseline, are significantly associated with an increased risk of mortality. The current results, in a randomized trial setting, underline the strong relationship between erythropoietin and FGF23 physiology in patients with chronic heart failure and chronic kidney disease. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00356733

    Platelets in Patients with Premature Coronary Artery Disease Exhibit Upregulation of miRNA340* and miRNA624*

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    Coronary artery disease (CAD) is the leading cause of human morbidity and mortality worldwide, underscoring the need to improve diagnostic strategies. Platelets play a major role, not only in the process of acute thrombosis during plaque rupture, but also in the formation of atherosclerosis itself. MicroRNAs are endogenous small non-coding RNAs that control gene expression and are expressed in a tissue and disease-specific manner. Therefore they have been proposed to be useful biomarkers. It remains unknown whether differences in miRNA expression levels in platelets can be found between patients with premature CAD and healthy controls. In this case-control study we measured relative expression levels of platelet miRNAs using microarrays from 12 patients with premature CAD and 12 age- and sex-matched healthy controls. Six platelet microRNAs were significantly upregulated (miR340*, miR451, miR454*, miR545:9.1. miR615-5p and miR624*) and one miRNA (miR1280) was significantly downregulated in patients with CAD as compared to healthy controls. To validate these results, we measured the expression levels of these candidate miRNAs by qRT-PCR in platelets of individuals from two independent cohorts; validation cohort I consisted of 40 patients with premature CAD and 40 healthy controls and validation cohort II consisted of 27 patients with artery disease and 40 healthy relatives. MiR340* and miR624* were confirmed to be upregulated in patients with CAD as compared to healthy controls in both validation cohorts. Two miRNAs in platelets are significantly upregulated in patients with CAD as compared to healthy controls. Whether the two identified miRNAs can be used as biomarkers and whether they are cause or consequence of the disease remains to be elucidated in a larger prospective stud

    Somatostatin receptor scintigraphy with [111In-DTPA-d-Phe1]- and [123I-Tyr3]-octreotide: the Rotterdam experience with more than 1000 patients

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    Various tumours, classically specified as either neuroendocrine or non-neuroendocrine, contain high numbers of somatostatin receptors, which enable in vivo localization of the primary tumour and its metastases by scintigraphy with the radiolabelled somatostatin analogue octreotide. In addition granulomas and autoimmune processes can be visualized because of local accumulation of somatostatin receptor-positive activated mononuclear leucocytes. In many instances a positive scintigram predicts a favourable response to treatment with octreotide. It is tempting to speculate that octreotide labelled with an appropriate radionuclide might be used in cancer therapy. The successful application of radiolabelled octreotide in scintigraphy indicates the possible usefulness of other radiolabelled peptides, either native peptides or derivatives of these, in, for example, nuclear oncology. The small size of these peptides, e.g. bombesin and substance P, is of the utmost importance for a relatively fast blood clearance, thus leading to low background radioactivity. In this way peptides are powerful alternatives to (fragments of) monoclonal antibodies, the application of which to scintigraphic localization of specific cell surface antigen-bearing tumours is plagued by slow blood clearance and, hence, high background levels

    Επισκόπηση ζιζανίων σε αμπελώνες Επαρχίας Λεμεσού

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    Από τα πιο σημαντικά, αν όχι το πιο σημαντικό πρόβλημα στη γεωργία σήμερα αποτελεί η παρουσία των ζιζανίων στις καλλιέργειες. Η εμφάνιση τους σε γεωργικές καλλιέργειες τα καθιστά ένα από τα πιο δυσεπίλυτα προβλήματα για τους παραγωγούς σήμερα. Η παρουσία τους οδηγεί σε άνισο ανταγωνισμό με τα καλλιεργούμενα φυτά σε θρεπτικά στοιχεία, φως, χώρο και νερό. Σ όλες τις χώρες τα ζιζάνια αποτελούν βασικό πρόβλημα στη γεωργία, έτσι και στη μικρή αλλά γεωργική Κύπρο, τα ζιζάνια δεν μπορούσαν να μην προκαλούν σοβαρές ζημιές. Σκοπός της παρούσας μελέτης ήταν η επιτόπια επισκόπηση καθώς και η καταγραφή σε αντιπροσωπευτικά εδαφοδείγματα από κάθε περιοχή των ζιζανίων σε αμπελώνες της επαρχίας Λεμεσού, σε πεδινές και ημιορεινές περιοχές. Πραγματοποιήθηκε επιτόπια επισκόπηση σε 4 διαφορετικές περιοχές ( δύο πεδινές και δύο ημιορεινές) σε δύο ή τρεις διαφορετικές εποχές. Από κάθε περιοχή, πάρθηκαν τυχαία δείγματα εδάφους, από 4-5 αγρούς της κάθε περιοχής, βάθους 0-30 οπι, σε 5 σημεία σε κάθε αγρό, σε απόσταση περίπου 100 πι μεταξύ τους. Τα μικτά δείγματα από κάθε αγρό μεταφέρθηκαν στο εργαστήριο, τοποθετήθηκαν σε φυτοδοχεία (30 χ 5 οπι) όπου έγινε βλάστηση και καταγραφή ζιζανίων για τρεις διαδοχικές περιόδους, διάρκειας ενός μήνα η κάθε μια. Μεταξύ των καταγραφών μεσολαβούσε διάστημα 15 ημερών και αναμόχλευση του εδάφους. Στην επιτόπια επισκόπηση των ζιζανίων στους πιο πάνω αμπελώνες καταγράφηκαν συνολικά 24 διαφορετικά είδη ζιζανίων από τα οποία τα 20 ήταν πλατύφυλλα και τα 4 αγρωστώδη. Στα εδαφοδείγματα στο εργαστήριο παρατηρήθηκαν συνολικά 22 είδη ζιζανίων εκ των οποίων τα 20 ήταν πλατύφυλλα και τα 2 αγρωστώδη. Τα ζιζάνια με τη μεγαλύτερη συχνότητα από τα πλατύφυλλα ήταν το πορφυρό λάμιο, η στελλάρια και η τσουκνίδα με συχνότητα 3/4 (αριθμός χωριών με παρουσία του ζιζανίου). Από τα αγρωστώδη τα ζιζάνια με την μεγαλύτερη συχνότητα ήταν η ήρα 4/4

    Sex Differences in Neoplastic Progression in Barrett's Esophagus:A Multicenter Prospective Cohort Study

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    Recommendations in Barrett’s esophagus (BE) guidelines are mainly based on male patients. We aimed to evaluate sex differences in BE patients in (1) probability of and (2) time to neoplastic progression, and (3) differences in the stage distribution of neoplasia. We conducted a multicenter prospective cohort study including 868 BE patients. Cox regression modeling and accelerated failure time modeling were used to estimate the sex differences. Neoplastic progression was defined as highgrade dysplasia (HGD) and/or esophageal adenocarcinoma (EAC). Among the 639 (74%) males and 229 females that were included (median follow-up 7.1 years), 61 (7.0%) developed HGD/EAC. Neoplastic progression risk was estimated to be twice as high among males (HR 2.26, 95% CI 1.11–4.62) than females. The risk of HGD was found to be higher in males (HR 3.76, 95% CI 1.33–10.6). Time to HGD/EAC (AR 0.52, 95% CI 0.29–0.95) and HGD (AR 0.40, 95% CI 0.19–0.86) was shorter in males. Females had proportionally more EAC than HGD and tended to have higher stages of neoplasia at diagnosis. In conclusion, both the risk of and time to neoplastic progression were higher in males. However, females were proportionally more often diagnosed with (advanced) EAC. We should strive for improved neoplastic risk stratification per individual BE patient, incorporating sex disparities into new prediction models

    Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

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    The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD

    Smoking cessation and bronchial epithelial remodelling in COPD: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Chronic Obstructive Pulmonary Disease (COPD) is associated with bronchial epithelial changes, including squamous cell metaplasia and goblet cell hyperplasia. These features are partially attributed to activation of the epidermal growth factor receptor (EGFR). Whereas smoking cessation reduces respiratory symptoms and lung function decline in COPD, inflammation persists. We determined epithelial proliferation and composition in bronchial biopsies from current and ex-smokers with COPD, and its relation to duration of smoking cessation.</p> <p>Methods</p> <p>114 COPD patients were studied cross-sectionally: 99 males/15 females, age 62 ± 8 years, median 42 pack-years, no corticosteroids, current (n = 72) or ex-smokers (n = 42, median cessation duration 3.5 years), postbronchodilator FEV<sub>1 </sub>63 ± 9% predicted. Squamous cell metaplasia (%), goblet cell (PAS/Alcian Blue<sup>+</sup>) area (%), proliferating (Ki-67<sup>+</sup>) cell numbers (/mm basement membrane), and EGFR expression (%) were measured in intact epithelium of bronchial biopsies.</p> <p>Results</p> <p>Ex-smokers with COPD had significantly less epithelial squamous cell metaplasia, proliferating cell numbers, and a trend towards reduced goblet cell area than current smokers with COPD (p = 0.025, p = 0.001, p = 0.081, respectively), but no significant difference in EGFR expression. Epithelial features were not different between short-term quitters (<3.5 years) and current smokers. Long-term quitters (≥3.5 years) had less goblet cell area than both current smokers and short-term quitters (medians: 7.9% vs. 14.4%, p = 0.005; 7.9% vs. 13.5%, p = 0.008; respectively), and less proliferating cell numbers than current smokers (2.8% vs. 18.6%, p < 0.001).</p> <p>Conclusion</p> <p>Ex-smokers with COPD had less bronchial epithelial remodelling than current smokers, which was only observed after long-term smoking cessation (>3.5 years).</p> <p>Trial registration</p> <p>NCT00158847</p

    Comparison of foot orthoses made by podiatrists, pedorthists and orthotists regarding plantar pressure reduction in The Netherlands

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    BACKGROUND: There is a need for evidence of clinical effectiveness of foot orthosis therapy. This study evaluated the effect of foot orthoses made by ten podiatrists, ten pedorthists and eleven orthotists on plantar pressure and walking convenience for three patients with metatarsalgia. Aims were to assess differences and variability between and within the disciplines. The relationship between the importance of pressure reduction and the effect on peak pressure was also evaluated. METHODS: Each therapist examined all three patients and was asked to rate the 'importance of pressure reduction' through a visual analogue scale. The orthoses were evaluated twice in two sessions while the patient walked on a treadmill. Plantar pressures were recorded with an in-sole measuring system. Patients scored walking convenience per orthosis. The effects of the orthoses on peak pressure reduction were calculated for the whole plantar surface of the forefoot and six regions: big toe and metatarsal one to five. RESULTS: Within each discipline there was an extensive variation in construction of the orthoses and achieved peak pressure reductions. Pedorthists and orthotists achieved greater maximal peak pressure reductions calculated over the whole forefoot than podiatrists: 960, 1020 and 750 kPa, respectively (p < .001). This was also true for the effect in the regions with the highest baseline peak pressures and walking convenience rated by patients A and B. There was a weak relationship between the 'importance of pressure reduction' and the achieved pressure reduction for orthotists, but no relationship for podiatrists and pedorthotists. CONCLUSION: The large variation for various aspects of foot orthoses therapy raises questions about a consistent use of concepts for pressures management within the professional groups
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