171 research outputs found

    Quasi-morphine abstinence behaviour GABA-ergic mechanisms and their localization

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    Di-n-propylacetate (DPA), generally known to be an anti-epileptic drug, induces a behavioural syndrome in rats resembling morphine abstinence behaviour, which is called, therefore, quasi-morphine abstinence beh~viour. An increase in GABA-ergic activity is probably responsible for this behavioural effect of DPA, since it has been shown to be suppressed by GABA-antagonists like bicuculline and picrotoxin. The experiments presented in this thesis were designed to investigate the central mechanisms involved in this quasi-morphine abstinence behaviour

    Титульні сторінки та зміст

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    The pharmaceutical industry is increasingly focusing on the development of biological therapeutics. These molecules generally cause no off-target toxicity and are highly species specific. Therefore, non-human primates (NHPs) are often the only relevant species in which to conduct regulatory safety testing to support clinical trials. However, species specificity and immunogenicity may negatively impact the predictive value of these ethically contentious animals and thus limits their value as a test species for drug development. To study what the value has been of 30 years of NHP testing in drug development, we investigated the drug registration files of all therapeutic monoclonal antibodies (mAbs) which were approved in the European Union to date. We analysed 30 mAbs of which 5 were diagnostic agents. As the industry moved towards the development of more human proteins, we observed that the average use of NHPs also increased. 16 registration files described studies in which anti-drug-antibodies caused increased clearance of the therapeutic and potentially confounded the study. Post mortem analysis in repeated-dose toxicity studies rarely revealed new or unexpected findings nor did embryofetal and peri-postnatal developmental toxicity studies. These issues limited the value of NHPs in the safety assessment of new monoclonal antibodies. To reduce the use of less relevant NHP studies in the development of new biological drugs, regulatory demands might be decreased, and manufacturers should be given incentives for successfully evaluating the safety of biological therapeutics using alternative technologies

    Mammary gland tumor promotion by chronic administration of IGF1 and the insulin analogue AspB10 in the p53R270H/⁺WAPCre mouse model

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    Insulin analogues are structurally modified molecules with altered pharmaco-kinetic and -dynamic properties compared to regular human insulin used by diabetic patients. While these compounds are tested for undesired mitogenic effects, an epidemiological discussion is ongoing regarding an association between insulin analogue therapy and increased cancer incidence, including breast cancer. Standard in vivo rodent carcinogenesis assays do not pick up this possible increased carcinogenic potential. Here we studied the role of insulin analogues in breast cancer development. For this we used the human relevant mammary gland specific p53R270H/⁺WAPCre mouse model. Animals received life long repeated treatment with four different insulin (-like) molecules: normal insulin, insulin glargine, insulin X10 (AspB10) or insulin-like growth factor 1 (IGF1). Insulin-like molecules with strong mitogenic signaling, insulin X10 and IGF1, significantly decreased the time for tumor development. Yet, insulin glargine and normal insulin, did not significantly decrease the latency time for (mammary gland) tumor development. The majority of tumors had an epithelial to mesenchymal transition phenotype (EMT), irrespective of treatment condition. Enhanced extracellular signaling related kinase (Erk) or serine/threonine kinase (Akt) mitogenic signaling was in particular present in tumors from the insulin X10 and IGF1 treatment groups. These data indicate that insulin-like molecules with enhanced mitogenic signaling increase the risk of breast cancer development. Moreover, the use of a tissue specific cancer model, like the p53R270H/⁺WAPCre mouse model, is relevant to assess the intrinsic pro-carcinogenic potential of mitogenic and non-mitogenic biologicals such as insulin analogues. INTRODUCTION METHODS RESULTS CONCLUSION

    The pre- and post-authorisation data published by the European medicines agency on the use of biologics during pregnancy and lactation

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    Aims: The effects of biologics on reproduction/lactation are mostly unknown although many patients that receive biologics are women of reproductive age. The first objective of this study was to investigate the publicly available data on pregnancy/lactation before and after marketing authorization in Europe of biologics for the indications of rheumatologic inflammatory autoimmune diseases and inflammatory bowel disease. Secondary objectives included the assessment of the clinical relevance of the provided data and comparison of initial and post-authorization data. Methods: Initial and post-authorization data were extracted from the European Public Assessment Reports and the latest versions of Summary of Product Characteristics using publicly available documents on the European Medicines Agency's website. Four sections were categorized regarding pregnancy outcomes: pre-clinical/animal studies, human female fertility, pregnancy-related outcomes and congenital malformations in the human fetus. Three sections were categorized regarding lactation outcomes: pre-clinical/animal studies, excretion in human breast milk and absorption in children through breastfeeding. The clinical applicability of each category was scored by specified criteria, based on scientific literature, and further as defined by the authors. Results: For the 16 included biologics, post-authorization data were delivered only for adalimumab, certolizumab pegol, etanercept and infliximab. For the 12 remaining biologics limited data on pregnancy and lactation during the post-marketing period of 2–21 years were available. Conclusions: In this article several suggestions are provided for improving a multidisciplinary approach to these issues. The initiation of suitable registries by marketing authorization holders and data transparency for clinicians and academics are highly endorsed

    Evaluation of an imaging-based in vitro screening platform for estrogenic activity with OECD reference chemicals

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    Estrogen receptor alpha (ERα) is often a primary target of endocrine disrupting chemicals (EDCs) and therefore several biochemical and cell-based assays for the detection of chemicals with estrogenic properties have been developed in the past. However, the current approaches are not suitable for the monitoring of pathway activation dynamics, and they are mostly based on expression constructs that lack physiological promoter regulation. We recently developed MCF7 fluorescent reporter cell lines of 3 different green fluorescent protein (GFP)-tagged ERα target genes: GREB1, PGR and TFF1. These reporters are under control of the full physiological promoter region and allow the monitoring of dynamic pro-proliferative pathway activation on a single cell level using a live-cell imaging set-up. In this study, we systematically characterized the response of these reporters to a full reference compound set of known estrogenic and non-estrogenic chemicals as defined by the Organization for Economic Co-Operation and Development (OECD). We linked activation of the pro-proliferative ERα pathway to a potential adverse outcome by additionally monitoring cell cycle progression and proliferation. The correct classification of the OECD reference compounds showed that our reporter platform has the same sensitivity and specificity as other validated artificial ERα pathway reporters, such as the ERα CALUX and VM7 Luc ER TA assay. By monitoring several key events (i.e. ER target activation, cell cycle progression and proliferation), and subsequently determining Point-of-Departure (POD) values, our reporter panel can be used in high-throughput testing for a physiologically more relevant, quantitative temporal endocrine modulation analysis to improve human carcinogen risk assessment.Toxicolog

    Important differences between quality of life and health status in elderly patients suffering from critical limb ischemia

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    Introduction Critical limb ischemia (CLI) patients are often of advanced age with reduced health status (HS) and quality of life (QoL) at baseline. Physical health is considered as the most affected domain due to reduced mobility and ischemic pain. QoL and HS are often used interchangeably in the current literature. HS refers to objectively perceived physical, psychological, and social functioning and in assessing QoL, change is measured subjectively and can only be determined by the individual since it concerns patients' evaluation of their functioning. It is important to distinguish between QoL and HS, especially in the concept of shared decision-making when the opinion of the patient is key. Goal of this study was to examine and compare QoL and HS in elderly CLI patients in relation to the used therapy, with a special interest in conservatively treated patients. Methods Patients suffering from CLI and ≥70 years old were included in a prospective study with a follow-up period of 1 year. Patients were divided into three groups; endovascular revascularization, surgical revascularization, and conservative therapy. The WHOQoL-Bref was used to determine QoL, and the 12-Item Short Form Health Survey was used to evaluate HS at baseline, 5-7 days, 6 weeks, 6 months, and 1 year. Results Physical QoL of endovascularly and surgically treated patients showed immediate significant improvement during follow-up in contrast to delayed increased physical HS at 6 weeks and 6 months (P<0.001). Conservatively treated patients showed significantly improved physical QoL at 6 and 12 months (P=0.02) in contrast to no significant improvement in physical HS. Conclusion This study demonstrates that QoL and HS are indeed not identical concepts and that differentiating between these two concepts could influence the choice of treatment in elderly CLI patients. Discriminating between QoL and HS is, therefore, of major importance for clinical practice, especially to achieve shared decision-making

    Human Cholangiocytes Form a Polarized and Functional Bile Duct on Hollow Fiber Membranes

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    Liver diseases affect hundreds of millions of people worldwide; most often the hepatocytes or cholangiocytes are damaged. Diseases of the biliary tract cause severe patient burden, and cholangiocytes, the cells lining the biliary tract, are sensitive to numerous drugs. Therefore, investigations into proper cholangiocyte functions are of utmost importance, which is restricted, in vitro, by the lack of primary human cholangiocytes allowing such screening. To investigate biliary function, including transepithelial transport, cholangiocytes must be cultured as three-dimensional (3D) ductular structures. We previously established murine intrahepatic cholangiocyte organoid-derived cholangiocyte-like cells (CLCs) and cultured them onto polyethersulfone hollow fiber membranes (HFMs) to generate 3D duct structures that resemble native bile ducts at the structural and functional level. Here, we established an efficient, stepwise method for directed differentiation of human intrahepatic cholangiocyte organoids (ICOs) into CLCs. Human ICO-derived CLCs showed key characteristics of cholangiocytes, such as the expression of structural and functional markers, formation of primary cilia, and P-glycoprotein-mediated transport in a polarized fashion. The organoid cultures exhibit farnesoid X receptor (FXR)-dependent functions that are vital to liver bile acid homeostasis in vivo. Furthermore, human ICO-derived CLCs cultured on HFMs in a differentiation medium form tubular architecture with some tight, confluent, and polarized monolayers that better mimic native bile duct characteristics than differentiated cultures in standard 2D or Matrigel-based 3D culture plates. Together, our optimized differentiation protocol to obtain CLC organoids, when applied on HFMs to form bioengineered bile ducts, will facilitate studying cholangiopathies and allow developing therapeutic strategies

    Risk factors and outcomes for postoperative delirium after major surgery in elderly patients

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    Background: Early identification of patients at risk for delirium is important, since adequate well timed interventions could prevent occurrence of delirium and related detrimental outcomes. The aim of this study is to evaluate prognostic factors for delirium, including factors describing frailty, in elderly patients undergoing major surgery. Methods: We included patients of 65 years and older, who underwent elective surgery from March 2013 to November 2014. Patients had surgery for Abdominal Aortic Aneurysm (AAA) or colorectal cancer. Delirium was scored prospectively using the Delirium Observation Screening Scale. Pre- and peri-operative predictors of delirium were analyzed using regression analysis. Outcomes after delirium included adverse events, length of hospital stay, discharge destination and mortality. Results: We included 232 patients. 51 (22%) underwent surgery for AAA and 181 (78%) for colorectal cancer. Postoperative delirium occurred in 35 patients (15%). Predictors of postoperative delirium included: delirium in medical history (Odds Ratio 12 [95% Confidence Interval 2.7-50]), advancing age (Odds Ratio 2.0 [95% Confidence Interval 1.1-3.8]) per 10 years, and ASA-score ≥3 (Odds Ratio 2.6 [95% Confidence Interval 1.1-5.9]). Occurrence of delirium was related to an increase in adverse events, length of hospital stay and mortality. Conclusion: Postoperative delirium is a frequent complication after major surgery in elderly patients and is related to an increase in adverse events, length of hospital stay, and mortality. A delirium in the medical history, advanced age, and ASA
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