98 research outputs found

    Enhancement of the Cytotoxic Effect of Anticancer Agent by Cytochrome c Functionalised Hybrid Nanoparticles in Hepatocellular Cancer Cells

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    Treatment of hepatocellular cancer with chemotherapeutic agents has limited success in clinical practice and their efficient IC50 concentration would require extremely high doses of drug administration which could not be tolerated due to systemic side effects. In order to potentiate the efficacy of anticancer agents we explored the potential of co-treatment with pro-apoptotic Cytochrome c which activates the apoptotic pathway downstream of p53 that is frequently mutated in cancer. To this end we used hybrid iron oxide-gold nanoparticles as a drug delivery system to facilitate the internalisation of Cytochrome c into cultured HepG2 hepatocellular carcinoma cells. Our results showed that Cytochrome c can be easily conjugated to the gold shell of the nanoparticles which are readily taken up by the cells. We used Cytochrome c in concentration (0.2µgmL-1) below the threshold required to induce apoptosis on its own. When the conjugate was administered to cells treated by doxorubicin, it significantly reduced its IC50 concentration from 9µgmL-1 to 3.5µgmL-1 as detected by cell viability assay, and the efficiency of doxorubicin on decreasing viability of HepG2 cells was significantly enhanced in the lower concentration range between 0.01µgmL-1 to 5µgmL-1. The results demonstrate the potential of the application of therapeutic proteins in activating the apoptotic pathway to complement conventional chemotherapy to increase its efficacy. The application of hybrid iron oxide-gold nanoparticles can also augment the specificity of drug targeting and could serve as a model drug delivery system for pro-apoptotic protein targeting and delivery

    Intercalibrating the national classifications of ecological status for Eastern Continental lakes: Biological Quality Element: Benthic invertebrates

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    The European Water Framework Directive (WFD) requires the national classifications of good ecological status to be harmonised through an intercalibration exercise. In this exercise, significant differences in status classification among Member States are harmonized by comparing and, if necessary, adjusting the good status boundaries of the national assessment methods. Intercalibration is performed for rivers, lakes, coastal and transitional waters, focusing on selected types of water bodies (intercalibration types), anthropogenic pressures and Biological Quality Elements. Intercalibration exercises were carried out in Geographical Intercalibration Groups - larger geographical units including Member States with similar water body types - and followed the procedure described in the WFD Common Implementation Strategy Guidance document on the intercalibration process (European Commission, 2011). The Technical reports are organized in volumes according to the water category (rivers, lakes, coastal and transitional waters), Biological Quality Element and Geographical Intercalibration group. This volume addresses the intercalibration of the Eastern Continental Lake GIG Benthic invertebrate ecological assessment methods. Three countries (Bulgaria, Hungary, Romania) participated in the intercalibration exercise and harmonised their lake benthic invertebrate systems. The results were approved by the WG ECOSTAT and included in the EC Decision on intercalibration (European Commission, 2018).JRC.D.2-Water and Marine Resource

    Developments in water quality monitoring and management in large river catchments using the Danube River as an example

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    Effective management of water quality in large rivers requires information on the influence of activities within the catchment (urban and rural) throughout the whole river basin. However, traditional water quality monitoring programmes undertaken by individual agencies normally relate to specific objectives, such as meeting quality criteria for wastewater discharges, and fail to provide information on basin-scale impacts, especially in transboundary river basins. Ideally, monitoring in large international river basins should be harmonised to provide a basin-scale assessment of sources and impacts of human activities, and the effectiveness of management actions. This paper examines current water quality issues in the Danube River basin and evaluates the approach to water quality monitoring in the context of providing information for a basin-wide management plan. Lessons learned from the monitoring programme in the Danube are used to suggest alternative approaches that could result in more efficient generation of water quality data and provide new insights into causes and impacts of variations in water quality in other large international river basins

    Gender, hyperandrogenism and vitamin D deficiency related functional and morphological alterations of rat cerebral arteries

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    Hyperandrogenism is a risk factor of cerebrovascular diseases as androgens can alter markedly the regulation of cerebrovascular tone. We examined the combined impact of androgen excess and vitamin D deficiency (VDD), a common co-morbidity in hyperandrogenic disorders, on remodeling and testosterone-induced vascular responses of anterior cerebral arteries (ACA) in order to evaluate the interplay between androgens and VDD in the cerebral vasculature. Male and female Wistar rats were either fed with vitamin D deficient or vitamin D supplemented diet. Half of the female animals from both groups received transdermal testosterone treatment. After 8 weeks, vessel lumen, wall thickness and testosterone-induced vascular tone of isolated ACA were determined using pressure microangiometry and histological examination. Androgen receptor protein expression in the wall of cerebral arteries was examined using immunohistochemistry. In female rats only combined VDD and testosterone treatment decreased the lumen and increased the wall thickness of ACA. In males, however VDD by itself was able to decrease the lumen and increase the wall thickness. Vascular reactivity showed similar alterations: in females, testosterone constricted the ACA only after combined VDD and hyperandrogenism, whereas in males VDD resulted in increased testosterone-induced contractions in spite of decreased androgen receptor expression. In conclusion, a marked interplay between hyperandrogenism and VDD results in inward remodeling and enhanced testosterone-induced constrictions of cerebral arteries, which might compromise the cerebral circulation and thus, increase the risk of stroke in the long term. In addition, the early cerebrovascular manifestation of VDD appears to require androgen excess and thus, depends on gender

    Best practice for establishing nutrient concentrations to support good ecological status

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    The EU Member States, Norway and the European Commission in 2000 have jointly developed a common implementation strategy (CIS) for implementing Directive 2000/60/EC, the Water Framework Directive (WFD) to ensure consistent implementation. The focus is on developing a common understanding of the technical and scientific implications of the WFD. One of the objectives is the development of non-legally binding and practical Guidance Documents on various technical issues of the Directive. These are targeted at experts who are directly or indirectly implementing the WFD in river basins. The structure, presentation and terminology are therefore adapted to their needs and formal, legalistic language is avoided wherever possible. In 2009 CIS Guidance on Eutrophication Assessment (Guidance Document No. 23) was published, providing guidance for evaluating the impacts of nutrient enrichment, a major cause of failure to achieve good status under the WFD. However, an apparently wide range of nutrient boundary values to support good ecological status had been established by the Member States. Water Directors requested that the CIS Working Group ECOSTAT investigate this issue, and the subsequent work has been led by the UK (Freshwaters), Germany (Saline waters) and JRC. The aim of the work was to establish the reasons for differences between Member States in the development and application of nutrient boundaries, leading to the production of this guidance on best practice. This work is an addition to, and not a replacement for, the earlier guidance on eutrophication assessment. In developing this guidance, a number of tasks have been undertaken. The range of nitrogen and phosphorus boundary values in use by Member States, and the methods used to derive those values has been reported separately, for both fresh and saline waters. Further work was undertaken to investigate nutrient pressure-biological response relationships in the different surface water categories. This work was then used to inform the development of this guide and the associated statistical toolkit. During the project a series of workshops were held involving nutrient experts nominated by Member States. These experts contributed to the development and testing of the guidance and toolkit, and provided details of alternative methods of boundary setting in use in some Member States. The purpose of this report is to provide technical guidance to enable Member States to establish new, or review existing, boundaries for phosphorus and nitrogen to support good ecological status. This should facilitate the establishment of comparable and consistent boundaries across all Member States. However it is recognised that alternative methods of arriving at boundary values may be valid, and use of this guidance and the associated statistical toolkit is ultimately a decision for the Member State. The responses of biological elements to nutrient availability are complex, and vary between water categories. This guidance is not therefore a substitute for the application of ecological knowledge and understanding at a local level. Furthermore, responses to nutrients may be confounded by the impact of other pressures acting on a water body, and our understanding of how to account for multiple stressors is still developing. The guidance does not specifically address how the nutrient boundaries are used to derive an overall classification, or to drive action to control nutrients, both of which may be relevant to the level at which the boundaries are set.JRC.D.2-Water and Marine Resource

    Practical guidelines for the supplementation of vitamin D and the treatment of deficits in Central Europe — recommended vitamin D intakes in the general population and groups at risk of vitamin D deficiency

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    Wstęp: Wyniki badań z ostatnich lat dokumentują wiele korzyści wynikających z działania witaminy D na organizm człowieka na wszystkichetapach jego życia. Większość badań epidemiologicznych sugeruje, że niedobór witaminy D jest powszechny wśród mieszkańców EuropyŚrodkowej. Naturalną konsekwencją tej sytuacji jest konieczność ciągłego uświadamiania społeczeństwu oraz środowisku medycznemu,jaką rolę odgrywa witamina D w rozwoju i funkcjonowaniu organizmu ludzkiego.Metody: Na podstawie przeglądu danych literaturowych Polski Zespół Wielodyscyplinarny opracował tezy dotyczące zasad suplementacjiwitaminą D, które przesłano do członków Komitetu Naukowego konferencji „Witamina D — minimum, maksimum, optimum”,19–20 Październik, 2012, Warszawa. W trakcie powyższej konferencji z udziałem 550 delegatów oraz Ekspertów różnych dziedzin medycynyomówiono i przedyskutowano propozycje wytycznych suplementacji witaminą D populacji Europy Środkowej.Wyniki: W efekcie przeprowadzonych dyskusji Zespół Ekspertów opracował wytyczne suplementacji witaminą D dla wszystkich grupwiekowych populacji Europy Środkowej. Określono również kryteria diagnostyczne charakteryzujące stan zaopatrzenia organizmu w witaminę D: deficyt witaminy D ustalono jako stężenie 25(OH)D < 20 ng/mL (< 50 nmol/L)], suboptymalne zaopatrzenie jako stężenie25(OH)D wynoszące 20–30 ng/mL (50–75 nmol/L), a stężenie 30–50 ng/mL (75–125 nmol/L) uznano za docelowe dla zapewnienia efektuplejotropowego witaminy D.Wnioski: Poprawa obecnego stanu zaopatrzenia witaminy D w grupach dzieci, młodzieży, osób aktywnych zawodowo i seniorówpowinna zostać włączona do priorytetów polityki zdrowotnej społeczeństw Europy Środkowej.Introduction: Adequate Vitamin D intake and its concentration in serum are important for bone health and calcium–phosphate metabolismas well as for optimal function of many organs and tissues. Documented trends in lifestyle, nutritional habits and physical activityappear to be associated with moderate or severe Vitamin D deficits resulting in health problems. Most epidemiological studies suggest thatVitamin D deficiency is prevalent among Central European populations. Concern about this problem led to the organising of a conferencefocused on overcoming Vitamin D deficiency.Methods: After reviewing the epidemiological evidence and relevant literature, a Polish multidisciplinary group formulated theses onrecommendations for Vitamin D screening and supplementation in the general population. These theses were subsequently sent to ScientificCommittee members of the ‘Vitamin D — minimum, maximum, optimum’ conference for evaluation based on a ten-point scale.With 550 international attendees, the meeting ‘Vitamin D — minimum, maximum, optimum’ was held on October 19–20, 2012 in Warsaw(Poland). Most recent scientific evidence of both skeletal and non-skeletal effects of Vitamin D as well as the results of panellists’ votingwere reviewed and discussed during eight plenary sessions and two workshops.Results: Based on many polemical discussions, including post-conference networking, the key opinion leaders established ranges ofserum 25-hydroxyVitamin D concentration indicating Vitamin D deficiency [< 20 ng/mL (< 50 nmol/L)], suboptimal status [20–30 ng/mL(50–75 nmol/L)], and target concentration for optimal Vitamin D effects [30–50 ng/mL (75–125 nmol/L)]. General practical guidelines regardingsupplementation and updated recommendations for prophylactic Vitamin D intakes in Central European neonates, infants, childrenand adolescents as well as in adults (including recommendations for pregnant and breastfeeding women and the elderly) were developed.Conclusions: Improving the Vitamin D status of children, adolescents, adults and the elderly must be included in the priorities of physicians,healthcare professionals and healthcare regulating bodies. The present paper offers elaborated consensus on supplementationguidance and population strategies for Vitamin D in Central Europe

    The involvement of FOXO1 in cytotoxic stress and drug-resistance induced by paclitaxel in ovarian cancers

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    The role of transcriptional factor FOXO1 in the mechanism of drug-resistance in ovarian cancer has not been elucidated. In ovarian cancer cell lines, FOXO1 expression and its correlation with paclitaxel treatment was investigated by cytotoxic assay and silencing experiment. Clinical ovarian cancer samples were also examined for FOXO1 expression by immunohistochemistry. FOXO1 expression was distinctively upregulated in paclitaxel-resistant cell line, and enhanced by exposure to paclitaxel. FOXO1 overexpression was frequently observed in tissue samples from chemoresistant patients compared to chemosensitive patients. FOXO1 silencing in paclitaxel-resistant cell line decreased its resistance. Modification of oxidative stress by co-treatment with pharmacologic modulators of reactive oxygen species attenuated cytotoxicity of paclitaxel. Downstream targets of FOXO1 involving oxidative stress were also attenuated in silencing experiment, suggesting its involvement in altered sensitivity to paclitaxel. These results indicate that FOXO1 links to cytotoxic stress induced by paclitaxel and contributes to the drug-resistance in ovarian cancers

    Reduced Estradiol-Induced Vasodilation and Poly-(ADP-Ribose) Polymerase (PARP) Activity in the Aortas of Rats with Experimental Polycystic Ovary Syndrome (PCOS)

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    Polycystic ovary syndrome (PCOS) is a complex endocrine disorder characterized by hyperandrogenism and insulin resistance, both of which have been connected to atherosclerosis. Indeed, an increased risk of clinical manifestations of arterial vascular diseases has been described in PCOS. On the other hand endothelial dysfunction can be detected early on, before atherosclerosis develops. Thus we assumed that vascular dysfunction is also related directly to the hormonal imbalance rather than to its metabolic consequences. To detect early functional changes, we applied a novel rodent model of PCOS: rats were either sham operated or hyperandrogenism was achieved by implanting subcutaneous pellets of dihydrotestosterone (DHT). After ten weeks, myograph measurements were performed on isolated aortic rings. Previously we described an increased contractility to norepinephrine (NE). Here we found a reduced immediate relaxation to estradiol treatment in pre-contracted aortic rings from hyperandrogenic rats. Although the administration of vitamin D3 along with DHT reduced responsiveness to NE, it did not restore relaxation to estradiol. Poly-(ADP-ribose) polymerase (PARP) activity was assessed by poly-ADP-ribose immunostaining. Increased PAR staining in ovaries and circulating leukocytes from DHT rats showed enhanced DNA damage, which was reduced by concomitant vitamin D3 treatment. Surprisingly, PAR staining was reduced in both the endothelium and vascular smooth muscle cells of the aorta rings from hyperandrogenic rats. Thus in the early phase of PCOS, vascular tone is already shifted towards vasoconstriction, characterized by reduced vasorelaxation and vascular dysfunction is concomitant with altered PARP activity. Based on our findings, PARP inhibitors might have a future perspective in restoring metabolic disorders in PCOS

    Intercalibrating the national classifications of ecological status for very large rivers in Europe: Biological Quality Element: Phytoplankton

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    The European Water Framework Directive (WFD) requires the national classifications of good ecological status to be harmonised through an intercalibration exercise. In this exercise, significant differences in status classification among Member States are harmonized by comparing and, if necessary, adjusting the good status boundaries of the national assessment methods. Intercalibration is performed for rivers, lakes, coastal and transitional waters, focusing on selected types of water bodies (intercalibration types), anthropogenic pressures and Biological Quality Elements. Intercalibration exercises were carried out in Geographical Intercalibration Groups - larger geographical units including Member States with similar water body types - and followed the procedure described in the WFD Common Implementation Strategy Guidance document on the intercalibration process (European Commission, 2011). The Technical reports are organized in volumes according to the water category (rivers, lakes, coastal and transitional waters), Biological Quality Element and Geographical Intercalibration group. This volume addresses the intercalibration of the Very large river Phytoplankton ecological assessment methods. Thirteen countries (Austria, Belgium (Flanders), Bulgaria, Croatia, Czech Republic, Estonia, Germany, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia) participated in the intercalibration exercise and harmonised their benthic invertebrate assessment systems. The results were approved by the WG ECOSTAT and included in the EC Decision on intercalibration (European Commission, 2018). In addition, four countries (Italy, Finland, Norway, Sweden) provided justification for excluding Phytoplankton BQE assessment system.JRC.D.2-Water and Marine Resource
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