Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 61
Filtrar
1.
Rozhl Chir ; 100(7): 330-338, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34465109

RESUMO

INTRODUCTION: Vascular graft infection in the aortoiliac territory (abdominal VGI) is undoubtedly one of the most serious complications in vascular surgery. The treatment is burdened with high mortality and morbidity rates. In 2020, the Guidelines on the Management of Vascular Graft and Endograft Infections were published by the European Society for Vascular Surgery (ESVS). In the light of these guidelines, we decided to review retrospectively all patients who presented to our institution with abdominal VGI. METHODS: Retrospective observational study of patients presented with abdominal VGI treated in our institution between 20112019 (9 years). The primary goal was to elucidate the rate of vascular graft infection in aortoiliac reconstructions performed between 20112019 and also the mortality rate in the patient cohort operated for this complication. The secondary goals were to evaluate the success rate and the complication rate in different types of reconstructions. RESULTS: In the defined period between 20112019 we performed 363 open aortoiliac reconstructions. During the same period we treated altogether 15 patients with abdominal VGI, whose primary reconstruction was mostly performed before 2011 (11 patients). In our cohort of patients who underwent reconstruction between 20112019 we observed a graft infection only in 4 cases (1.1%). In the group of 15 patients with abdominal VGI, the male gender prevailed (14 patients). The mean age at the time of primary reconstruction was 61 years. Most of our reconstructions were performed for occlusive disease (14 cases). All infected grafts were aortobifemoral (1 unilateral aortofemoral). They were all late infections with an average presentation time of 61 months since the primary reconstruction (15180 months). Early mortality rate was as high as 27% (4 patients) and overall mortality was 40%. The secondary reinfection rate after primary treatment was 33%. CONCLUSION: Treatment of abdominal VGI is still burdened with high mortality and morbidity rates. The current ESVS guidelines provide valuable guidance for the diagnosis and management of VGI. It nevertheless remains obvious that the treatment needs to be tailored individually in a multidisciplinary team environment.


Assuntos
Prótese Vascular , Procedimentos Cirúrgicos Vasculares , Aorta Abdominal/cirurgia , Prótese Vascular/efeitos adversos , Humanos , Artéria Ilíaca , Masculino , Estudos Retrospectivos , Stents , Resultado do Tratamento
2.
Public Health ; 145: 136-145, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28359382

RESUMO

OBJECTIVES: The objective of this review paper was to stimulate collaborative discussions toward the development of a general concept of an open source protocol for a feasible and efficient longitudinal birth cohort study exploring non-communicable diseases (NCDs), their multifactorial etiology and relations between various risk factors. STUDY DESIGN: The present paper systematically reviews the design of existing birth cohorts in Europe containing environmental exposure data, and assesses a quantity and quality of their research outcomes as their potential to be an effective tool for studying non-communicable diseases and their risk factors. METHODS: European birth cohorts with more than 3000 participants have been included in the study. A total number of scientific papers published in the internationally recognized journals and their impact factors and citation records were evaluated for all cohorts as surrogates for their efficiency to contribute to NCDs understanding and thus their prevention. RESULTS: The birth cohorts contributing most significantly to the NCD understanding shared common features: (i) study size between 10,000 and 15,000 mother-child pairs; (ii) repeated assessment of children from prenatal into adulthood; and (iii) availability of biological samples. Smaller cohorts and cohorts with a specific focus generated a lower number of publications; however, these often received considerably a higher number of citations. CONCLUSIONS: General cohort studies with 10,000-15,000 mother-child pairs allow a broader context interpretation, publish a higher number of articles, and often lead to the formation of infrastructures for 'spin-off (nested) studies'.


Assuntos
Estudos de Coortes , Exposição Ambiental , População Branca , Criança , Bases de Dados Factuais , Europa (Continente) , Humanos , Recém-Nascido , Estudos Longitudinais , Fatores de Risco
3.
Toxicon ; 133: 48-57, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28428069

RESUMO

The beta-N-methylamino-l-alanine (BMAA) is a non-proteinogenic amino acid discussed to be produced by cyanobacteria forming harmful blooms. Since BMAA is suspected etiological agent in neurodegenerative diseases, there is a need to study and validate whether and in what concentrations can BMAA be present in human tissues. The aim of the present study was to validate analytical and extraction procedures for quantification of non-derivatized BMAA in the urine using liquid chromatography and commercial ELISA Kit. The study was focused on BMAA in different forms - dissolved, protein associated and total. The validated protocol included SPE followed by HILIC MS/MS for analyses of non-derivatized free form of BMAA with a limit of quantification 20 ng/mL. The methods for other BMAA forms (i.e. protein-associated and total) were also assessed but high matrix interferences did not allow their implementation. The method was used for analyses of free BMAA in 23 urine samples from healthy volunteers and psychiatric patients suffering from nonspecific neurological symptoms. Traces of BMAA were suspectedly detected in a single urine sample but they were not unequivocally proved according to all conservative analytical criteria. BMAA was also not confirmed in a repeatedly collected sample from the same person. The evaluated commercial BMAA ELISA Kit (Abraxis) was not suitable for determination of BMAA in extracted urine samples because of systematically highly false positive results. In agreement with recent findings, analyses of BMAA appear to methodologically challenging, and further research on BMAA in human tissues (or its precursors with potency to form BMAA under natural conditions or - eventually - during sample processing) is needed to clarify its potential ethiological role in neurodegenerative diseases.


Assuntos
Diamino Aminoácidos/urina , Transtornos Mentais/urina , Neurotoxinas/urina , Adulto , Idoso , Cromatografia Líquida/métodos , Toxinas de Cianobactérias , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem/métodos
5.
J Dairy Sci ; 99(9): 6973-6982, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27394955

RESUMO

Isoflavones are natural phytoestrogens with antioxidant and endocrine-disrupting potencies. Monitoring of their levels is important to ensure the high quality and safety of food, milk, and dairy products. The efficiency and accuracy of phytoestrogen analyses in complex matrices such as milk depend on the extraction procedure, which often uses hydrolysis by means of the ß-glucuronidase/sulfatase enzyme originating from Helix pomatia. The present study reveals that the commercially available hydrolytic enzyme is contaminated by several phytoestrogen isoflavones (genistein, daidzein, formononetin, and biochanin A) and their metabolite equol, as well as flavones (naringenin and apigenin) and coumestrol. We show that the concentrations of daidzein and genistein in the enzyme could have impaired the results of analyses of the main isoflavones in several previously published studies. Of 8 analyzed compounds, only equol was confirmed in the present study and it serves as a reliable marker of phytoestrogens originating from cow feed. Critical reassessment of phytoestrogen concentrations in milk is needed because several previously published studies might have overestimated the concentrations depending on the extraction procedure used.


Assuntos
Leite/química , Fitoestrógenos , Animais , Bovinos , Cumestrol , Feminino , Glucuronidase , Isoflavonas , Óvulo
6.
Anal Bioanal Chem ; 406(24): 5867-76, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25069883

RESUMO

The paper presents the development of an advanced extraction and fast analytical LC MS/MS method for simultaneous analyses of reduced and oxidized glutathione (GSH and GSSG, respectively) in different animal tissues. The simultaneous determination of GSH and GSSG is crucial because the amount and ratio of both GSH and GSSG may be altered in response to oxidative stress, an important mechanism of toxicity. The method uses the derivatization of free thiol groups in GSH. Its performance was demonstrated for less explored tissues (lung, brain, and liver) in mouse. The combined extraction and analytical method has very low variability and good reproducibility, maximum coefficients of variance for within-run and between-run analyses under 8 %, and low limits of quantification; for GSH and GSSG, these were 0.2 nM (0.06 ng/mL) and 10 nM (6 ng/mL), respectively. The performance of the method was further demonstrated in a model experiment addressing changes in GSH and GSSG concentrations in lung of mice exposed to CdO nanoparticles during acute 72 h and chronic 13-week exposures. Inhalation exposure led to increased GSH concentrations in lung. GSSG levels were in general not affected; nonsignificant suppression occurred only after the longer 13-week period of exposure. The developed method for the sensitive detection of both GSH and GSSG in very low tissue mass enables these parameters to be studied in cases where only a little sample is available, i.e. in small organisms or in small amounts of tissue.


Assuntos
Cádmio/toxicidade , Cromatografia Líquida/métodos , Dissulfeto de Glutationa/análise , Glutationa/análise , Exposição por Inalação/análise , Fígado/química , Pulmão/química , Espectrometria de Massas/métodos , Animais , Cádmio/metabolismo , Feminino , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Nanopartículas/metabolismo , Nanopartículas/toxicidade
7.
Environ Pollut ; 189: 126-33, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24657606

RESUMO

Species Sensitivity Distribution (SSD) is a statistical model that can be used to predict effects of contaminants on biological communities, but only few comparisons of this model with field studies have been conducted so far. In the present study we used measured pesticides concentrations from streams in Germany, France, and Finland, and we used SSD to calculate msPAF (multiple substance potentially affected fraction) values based on maximum toxic stress at localities. We compared these SSD-based predictions with the actual effects on stream invertebrates quantified by the SPEARpesticides bioindicator. The results show that the msPAFs correlated well with the bioindicator, however, the generally accepted SSD threshold msPAF of 0.05 (5% of species are predicted to be affected) severely underestimated the observed effects (msPAF values causing significant effects are 2-1000-times lower). These results demonstrate that validation with field data is required to define the appropriate thresholds for SSD predictions.


Assuntos
Monitoramento Ambiental/métodos , Modelos Estatísticos , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/efeitos dos fármacos , Relação Dose-Resposta a Droga , Finlândia , França , Alemanha , Invertebrados/efeitos dos fármacos , Praguicidas/toxicidade , Medição de Risco/métodos , Rios/química , Especificidade da Espécie
8.
J Hazard Mater ; 262: 571-9, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24095997

RESUMO

Despite intensive research into toxic bloom-forming cyanobacteria, the majority of their metabolites remain unknown. The present study explored in detail a novel bioactivity identified in cyanobacteria, i.e. inhibition of gap junctional intercellular communication (GJIC), a marker of tumor promotion. The extracellular mixture (exudate) of the cyanobacterial strain Cylindrospermopsis raciborskii (SAG 1.97) was fractionated by semi-preparative reversed phase HPLC, and the fractions assessed for their potencies to inhibit GJIC. Two non-polar fractions that significantly inhibited GJIC were further fractionated, tested and analyzed using multiple mass spectrometric methods. Investigations led to the identification of a putative chemical compound (molecular formula C18H34O3, m/z 299.2581 for the [M+H](+) ion) responsible for observed bioactivities. Specific inhibitors of signaling pathways were used to screen for biochemical mechanisms beyond GJIC inhibition, and the results indicate the involvement of ERK1/2 kinases via a mechanism related to the action of epidermal growth factor EGF but clearly distinct from other anthropogenic tumor promoters like polychlorinated biphenyls or polycyclic aromatic hydrocarbons. The chemical and in vitro toxicological characterizations of the newly described metabolite provide important insights into the still poorly understood health impacts of complex toxic cyanobacterial blooms and indicate that currently applied monitoring practices may underestimate actual risks.


Assuntos
Toxinas Bacterianas/farmacologia , Comunicação Celular/efeitos dos fármacos , Cylindrospermopsis/metabolismo , Junções Comunicantes/efeitos dos fármacos , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ratos
9.
Environ Int ; 59: 372-83, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23911337

RESUMO

Passive and composite sampling in combination with in vitro bioassays and identification and quantification of individual chemicals were applied to characterize pollution by compounds with several specific modes of action in urban area in the basin of two rivers, with 400,000 inhabitants and a variety of industrial activities. Two types of passive samplers, semipermeable membrane devices (SPMD) for hydrophobic contaminants and polar organic chemical integrative samplers (POCIS) for polar compounds such as pesticides and pharmaceuticals, were used to sample wastewater treatment plant (WWTP) influent and effluent as well as rivers upstream and downstream of the urban complex and the WWTP. Compounds with endocrine disruptive potency were detected in river water and WWTP influent and effluent. Year-round, monthly assessment of waste waters by bioassays documented estrogenic, androgenic and dioxin-like potency as well as cytotoxicity in influent waters of the WWTP and allowed characterization of seasonal variability of these biological potentials in waste waters. The WWTP effectively removed cytotoxic compounds, xenoestrogens and xenoandrogens. There was significant variability in treatment efficiency of dioxin-like potency. The study indicates that the WWTP, despite its up-to-date technology, can contribute endocrine disrupting compounds to the river. Riverine samples exhibited dioxin-like, antiestrogenic and antiandrogenic potencies. The study design enabled characterization of effects of the urban complex and the WWTP on the river. Concentrations of PAHs and contaminants and specific biological potencies sampled by POCIS decreased as a function of distance from the city.


Assuntos
Disruptores Endócrinos/análise , Receptores Androgênicos/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Estrogênio/metabolismo , Rios/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Androgênios/análise , Androgênios/farmacologia , Animais , Bioensaio , Linhagem Celular Tumoral , Cidades , República Tcheca , Dioxinas/análise , Dioxinas/farmacologia , Disruptores Endócrinos/farmacologia , Monitoramento Ambiental , Estrogênios/análise , Estrogênios/farmacologia , Praguicidas/análise , Praguicidas/farmacologia , Dibenzodioxinas Policloradas/análise , Dibenzodioxinas Policloradas/farmacologia , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/farmacologia , Ratos , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/farmacologia , Purificação da Água
10.
Environ Int ; 45: 22-31, 2012 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-22572113

RESUMO

Endocrine-disruptive potential and concentrations of polar organic contaminants were measured in seven headwaters flowing through relatively unpolluted areas of the Czech Republic. Towns with Wastewater Treatment Plant (WWTP) discharges were the first known sources of anthropogenic pollution in the areas. River water was sampled several kilometers upstream (US) and several tens of meters downstream (DS) of the WWTP discharges, by use of Pesticide and Pharmaceutical Polar Organic Integrative Samplers (POCIS-Pest, POCIS-Pharm). Extracts of passive samplers were tested by use of a battery of in vitro bioassays to determine overall non-specific cytotoxicity, endocrine-disruptive (ED) potential and dioxin-like toxicity. The extracts were also used for quantification of polar organics. There was little toxicity to cells caused by most extracts of POCIS. Estrogenicity was detected in all types of samples even though US locations are considered to be background. At US locations, concentrations of estrogen equivalents (EEq) ranged from less than the detection limits (LOD) to 0.5 ng EEq/POCIS. Downstream concentrations of EEqs ranged from less than LOD to 4.8 ng EEq/POCIS. Concentrations of EEq in POCIS extracts from all DS locations were 1 to 14 times greater than those at US locations. Concentrations of EEq measured in extracts of POCIS-Pest and POCIS-Pharm were in a good agreement. Neither antiestrogenic nor anti/androgenic activities were detected. Concentrations of 2,3,7,8-TCDD equivalents (TEq(bio)) were detected in both types of POCIS at concentrations ranging from less than the LOD to 0.39 ng TEq(bio)/POCIS. Nearly all extracts of POCIS-Pharm contained greater concentrations of TEq(bio) activity than extracts of POCIS-Pest. Concentrations of pesticides and pharmaceuticals in extracts of POCIS were generally small at all sampling sites, but levels of some pharmaceuticals were significantly greater in both types of POCIS from DS locations. Chemical analyses along with the results of bioassays documented impacts of small towns with WWTPs on headwaters.


Assuntos
Disruptores Endócrinos/análise , Poluentes Químicos da Água/análise , Bioensaio , República Tcheca , Dioxinas/análise , Dioxinas/toxicidade , Disruptores Endócrinos/toxicidade , Monitoramento Ambiental , Estrogênios/análise , Estrogênios/toxicidade , Água Doce , Interações Hidrofóbicas e Hidrofílicas , Praguicidas/análise , Praguicidas/toxicidade , Rios/química , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/análise , Águas Residuárias/estatística & dados numéricos , Poluentes Químicos da Água/toxicidade , Poluição Química da Água/estatística & dados numéricos
11.
Environ Int ; 39(1): 134-40, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22208753

RESUMO

Here is presented some of the first information on interactions of compounds produced by cyanobacteria and green algae with estrogen receptor signaling. Estrogenic potency of aqueous extracts and exudates (culture spent media with extracellular products) of seven species of cyanobacteria (10 different laboratory strains) and two algal species were assessed by use of in vitro trans-activation assays. Compounds produced by cyanobacteria and algae, and in particular those excreted from the cells, were estrogenic. Most exudates were estrogenic with potencies expressed at 50% of the maximum response under control of the estrogen receptor ranging from 0.2 to 7.2 ng 17ß-estradiol (E(2)) equivalents (EEQ)/L. The greatest estrogenic potency was observed for exudates of Microcystis aerigunosa, a common species that forms water blooms. Aqueous extracts of both green algae, but only one species of cyanobacteria (Aphanizomenon gracile) elicited significant estrogenicity with EEQ ranging from 15 to 280 ng 17ß-estradiol (E(2))/g dry weight. Scenedesmus quadricauda exudates and extracts of Aphanizomenon flos-aquae were antagonistic to the ER when coexposed to E(2). The EEQ potency was not correlated with concentrations of cyanotoxins, such as microcystin and cylindrospermopsin, which suggests that the EEQ was comprised of other compounds. The study demonstrates some differences between the estrogenic potency of aqueous extracts prepared from the same species, but of different origin, while the effects of exudates were comparable within species. The observed estrogenic potencies are important namely in relation to the possible mass expansion of cyanobacteria and release of the active compounds into surrounding water.


Assuntos
Clorófitas/metabolismo , Cianobactérias/metabolismo , Estrogênios/metabolismo , Exsudatos e Transudatos/química , Poluentes Químicos da Água/metabolismo , Aphanizomenon/metabolismo , Bioensaio , Comunicação Celular/fisiologia , Relação Dose-Resposta a Droga , Disruptores Endócrinos/metabolismo , Disruptores Endócrinos/farmacologia , Estradiol/metabolismo , Estradiol/farmacologia , Estrogênios/farmacologia , Eutrofização , Microcystis/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Poluentes Químicos da Água/farmacologia
12.
Aquat Toxicol ; 105(3-4): 497-507, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21903046

RESUMO

The biological activity of cyanobacteria and their chemical components have been widely studied due to their blooms in eutrophic waters worldwide. The primary goal of this study was to determine if individual cyanobacterial species and mixtures of cyanobacteria collected from the environment contain compounds with the potential for interaction with signaling pathways of the aryl hydrocarbon receptor (AhR), androgen receptor (AR), estrogen receptor (ER), glucocorticoid receptor (GR) and retinoid acid receptor (RAR). Cytotoxicity and specific toxic potencies of products of freshwater cyanobacteria were determined by use of in vitro reporter gene trans-activation assays. The testing included samples prepared from five selected single cyanobacterial species cultivated in laboratory and five complex cyanobacterial biomasses collected from blooms in surface waters in the Czech Republic. The results demonstrate estrogenic potencies of extracts of cyanobacterial biomasses. Among the laboratory single species, the extract of Planktothrix agardhii (intracellular metabolites) had a potency of estrogenic equivalents (EEQ) of 3.8 ng 17ß-estradiol/g dw. The estimates of EEQs of samples prepared from complex cyanobacterial biomasses collected from freshwaters in the Czech Republic ranged from 19 to 2200 ng 17ß-estradiol/g dw. Several samples prepared from the environmental cyanobacterial biomasses potentiated the androgenic potency of dihydrotestosterone. There was no dioxin-like, glucocorticoid or anti/retinoic activity observed for any of the extracts studied. Extracts of natural complex cyanobacterial biomasses exhibited greater and more frequent presence of compounds with specific modes of action, mainly estrogenic, and also greater cytotoxicity than extracts of single cyanobacterial species. The demonstrated estrogenic potency of the compounds present in complex cyanobacterial biomasses is of environmental relevance, and could potentially contribute to endocrine disruptive effects in aquatic ecosystems in case of great bloom densities.


Assuntos
Misturas Complexas/toxicidade , Cianobactérias/química , Citotoxinas/toxicidade , Disruptores Endócrinos/toxicidade , Estrogênios/toxicidade , Transdução de Sinais/efeitos dos fármacos , Animais , Toxinas Bacterianas/toxicidade , Bioensaio , Biomassa , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Técnicas In Vitro , Microcistinas/toxicidade , Ratos , Receptores Androgênicos/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Glucocorticoides/metabolismo , Receptores do Ácido Retinoico/metabolismo
13.
Klin Onkol ; 24(3): 195-202, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21714452

RESUMO

BACKGROUNDS: Occupational exposure to antineoplastic agents may represent a risk to health care workers, although the relevance of different exposure routes is not fully understood. The objectives of this study were to determine in vitro permeation of four widely used cytotoxic drugs (cisplatin, cyclophosphamide, doxorubicin, and fluorouracil) through two reconstituted tissue models representing human skin epidermis and oral mucosa. MATERIALS AND METHODS: Experiments were conducted with reconstructed models of human epidermis and oral epithelium, cultured in a chemically-defined medium under conditions simulating possible exposure scenarios (6 h duration, three concentrations corresponding to commonly used application doses). The amounts of drugs permeated through the tissues into the receptor media were determined using ultra performance liquid chromatography with photospectrometric detection. RESULTS: The highest epidermis permeations (P = 0.2 x 10(-3) - 1.5 x 10(-3) cm x h(-1)) were observed with three polar drugs (cisplatin, cyclophosphamide and fluorouracil), while permeation by more hydrophobic doxorubicin was minor (P(max) = 0.03 x 10(-3) cm x h(-1)). As expected, more pronounced tissue permeation was observed with the reconstructed oral epithelium having the maximum permeability coefficient (P = 180 x 10(-3) cm x h(-1)) for cisplatin and fluorouracil. Histological evaluation of the exposed tissues revealed cytotoxic effects at higher doses, especially for oral epithelium. CONCLUSION: Although the skin epidermis with keratinised stratum corneum provided relatively good protection, uptake (of at least some investigated drugs) via both types of tissue should not be underestimated. Our results provide basic experimental data on the skin and oral epithelia permeation for further modelling of exposure and health risk assessment.


Assuntos
Antineoplásicos/farmacocinética , Epiderme/metabolismo , Mucosa Bucal/metabolismo , Linhagem Celular , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Cisplatino/farmacocinética , Ciclofosfamida/farmacocinética , Doxorrubicina/farmacocinética , Fluoruracila/farmacocinética , Humanos , Técnicas In Vitro , Exposição Ocupacional , Permeabilidade
14.
Anal Bioanal Chem ; 398(3): 1231-7, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20535609

RESUMO

Microcystins are cyclic peptide toxins with hepatotoxic and tumour-promoting properties which are produced in high quantities in freshwater cyanobacterial water blooms, and several studies have reported microcystin accumulation in fish with possible food transfer to humans. In this study, we provide the first comparison of liquid chromatography with single mass-spectrometric and with tandem mass-spectrometric detection for analyses of microcystins in complex fish tissue samples. Use of traditional single mass spectrometry (i.e. monitoring of ions with m/z 519.5 for microcystin-RR and m/z 995.5 for microcystin-LR) was found to provide false-positive responses, thus overestimating the concentrations of microcystins in the tissue samples. More selective tandem mass spectrometry seems to provide more reliable results. The concentrations of microcystins detected by tandem mass spectrometry in fish from controlled-exposure experiments were more than 50% lower in comparison with concentrations obtained by single mass spectrometry. Extensive analyses of edible fish parts-muscles (148 fish specimens from eight different species from five natural reservoirs with dense cyanobacterial water blooms)-showed negligible microcystin concentrations (all analyses below the limit of detection; limit of detection of 1.2-5.4 ng/g fresh weight for microcystin-RR, microcystin-YR and microcystin-LR in multiple reaction monitoring mode). Our findings have practical consequences for critical re-evaluation of the health risks of microcystins accumulated in fish.


Assuntos
Cromatografia Líquida/métodos , Peixes , Espectrometria de Massas/métodos , Microcistinas/análise , Animais
15.
Klin Onkol ; 22(5): 218-22, 2009.
Artigo em Tcheco | MEDLINE | ID: mdl-19886359

RESUMO

BACKGROUNDS: The CYTO project studies an important aspect of healthcare provision -long-term occupational exposure, both threshold and below-threshold, to chemical agents with carcinogenic and mutagenic properties, with the major focus on antineoplastic drugs.This contribution presents experimental results from the first stages of the project's experimental work, i.e. an evaluation of the physico-chemical characteristics of cytostatic agents (evaporation) and an investigation into protective glove permeation. MATERIALS AND METHODS: In co-operation with IUTA (Institut für Energie- und Umwelttechnik e.V., Duisburg, Germany), the vapour pressure of paclitaxel, doxorubicin and dacarbazine was measured following OECD guideline No. 104: Vapour pressure curve--vapour pressure balance. Furthermore, the evaporation of cytostatic drugs was examined in actual laboratory conditions by monitoring the airborne concentration using the passive sampling technique. Besides the evaporation of selected drugs, the permeation of cisplatin, cyclophosphamide, doxorubicin, 5-fluorouracil and paclitaxel through different types of gloves (vinyl, latex, nitrile) was assessed. RESULTS: Although our experiments showed relatively slow evaporation of the evaluated cytostatic drugs (the highest pressure in paclitaxel was 0.024 Pa), equilibrium concentrations may go up to milligrams per cubic metre. Nevertheless, analytical measurements of airborne contamination did not confirm these concentration levels. The glove permeation experiments with cytostatics showed good resistance of nitrile gloves (which were impermeable to all five drugs). Other materials should be avoided while handling cytostatic agents (e.g. maximum permeation of cyclophosphamide through latex was 19 microg/sq cm/hr). CONCLUSION: Although the volatility of cytostatic agents is low, it cannot be neglected considering the chronic character of exposure. However, in order to estimate actual occupational exposure, future research should focus on the development of sensitive analytical methods. Nevertheless, dermal uptake is supposed to be the major route of exposure and use of protective gloves is necessary to minimize potential risks. Our simulated time-dependent permeation experiments with cytostatic agents and different glove materials showed that good protection is provided only by nitrile gloves. The results obtained in this study will be used for the modelling of exposure doses and health risk assessment in the subsequent stages of the CYTO research project.


Assuntos
Poluentes Ocupacionais do Ar/análise , Antineoplásicos/química , Monitoramento Ambiental , Luvas Protetoras , Pessoal de Saúde , Exposição Ocupacional , Humanos , Látex , Nitrilas , Permeabilidade , Compostos de Vinila , Volatilização
16.
Aquat Toxicol ; 89(3): 172-9, 2008 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-18675471

RESUMO

Lake Pilnok located in the black coal-mining region Ostrava-Karvina, Czech Republic, contains sediments highly contaminated with powdered waste coal. Moreover, population of the endangered species of narrow-clawed crayfish Pontastacus leptodactylus with high proportion of intersex individuals (18%) was observed at this site. These findings motivated our work that aimed to evaluate contamination, endocrine disruptive potency using in vitro assays and in vivo effects of contaminated sediments on reproduction of sediment-dwelling invertebrates. Chemical analyses revealed low concentrations of persistent chlorinated compounds and heavy metals but concentrations of polycyclic aromatic hydrocarbons (PAH) were high (sum of 16 PAHs 10 microg/g dw). Organic extracts from sediments caused significant in vitro AhR-mediated activity in the bioassay with H4IIE-luc cells, estrogenicity in MVLN cells and anti-androgenicity in recombinant yeast assay, and these effects could be attributed to non-persistent compounds derived from the waste coal. We have also observed significant in vivo effects of the sediments in laboratory experiments with the Prosobranchian euryhaline mud snail Potamopyrgus antipodarum. Sediments from Lake Pilnok as well as organic extracts of the sediments (externally added to the control sediment) significantly affected fecundity during 8 weeks of exposure. The effects were stimulations of fecundity at lower concentrations at the beginning of the experiment followed by inhibitions of fecundity and general toxicity. Our study indicates presence of chemicals that affected endocrine balance in invertebrates, and emphasizes the need for integrated approaches combining in vitro and in vivo bioassays with identification of chemicals to elucidate ecotoxicogical impacts of contaminated sediment samples.


Assuntos
Disruptores Endócrinos/toxicidade , Sedimentos Geológicos/química , Caramujos/efeitos dos fármacos , Animais , Bioensaio , Linhagem Celular , Disruptores Endócrinos/química , Feminino , Metais Pesados/química , Metais Pesados/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/química , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Receptores Androgênicos/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Estrogênio/metabolismo , Caramujos/metabolismo
17.
Chemosphere ; 67(6): 1096-101, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17223168

RESUMO

Humic substances (HS) were for decades regarded as inert in the ecosystems with respect to their possible toxicity. However, HS have been recently shown to elicit various adverse effects generally attributed to xenobiotics. In our study, we used MVLN and H4IIE-luc cell lines stably transfected with luciferase gene under control of estrogen receptor (ER) and Ah receptor (AhR; receptor connected with so-called dioxin-like toxicity) for assessment of anti/estrogenic and AhR-mediated effects of 12 commercially available humic substances. Out of those, five humic acids were shown to induce AhR-mediated activity with relative potencies related to TCDD 2.6 x 10(-8)-7.4 x 10(-8). Organic extracts of HS solutions also elicited high activities what means that lipophilic molecules are responsible for a great part of effect. However, relatively high activity remaining in extracted solution suggests also presence of polar AhR-agonists. Contribution of persistent organic compounds to the observed effects was ruled out by H(2)SO(4) treatment. Eight out of twelve HS elicited significant antiestrogenic effects with IC(50) ranging from 40 to 164 mg l(-1). The possible explanations of the antiestrogenic effect include sorption of 17-beta-estradiol (E2) on HS, changes in membrane permeability for E2 or another specific mechanism.


Assuntos
Moduladores de Receptor Estrogênico/farmacologia , Substâncias Húmicas/toxicidade , Receptores de Hidrocarboneto Arílico/fisiologia , Animais , Benzopiranos/toxicidade , Linhagem Celular Tumoral , Humanos , Dibenzodioxinas Policloradas/toxicidade , Ratos , Receptores de Hidrocarboneto Arílico/efeitos dos fármacos , Receptores de Estrogênio/efeitos dos fármacos
18.
Ecotoxicology ; 15(8): 623-7, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17043765

RESUMO

The objective of this article is to inform about efforts to design and implement a data model that can parametrically describe and store information about a wide range of ecotoxicological tests and bioindication methods used in Ecological Risk Assessment (EcoRA). At the same time it describes comprehensive web-based portal built on this model that can be used to quickly find relevant biological assays (ecotoxicological biotests) for given situation and therefore support the decision-making process in EcoRA. The model structure, features of the corresponding website and its current content is described in detail and proposed development and possible collaboration is outlined. The portal (DATEST) is located at http://projects.cba.muni.cz/datest. The aim of this work is to complement existing EcoRA decision-support tools with a web-based engine for storing and searching biological tests and methods used in EcoRA as there is currently no similar informational source available on the Internet.


Assuntos
Conservação dos Recursos Naturais , Internet , Modelos Teóricos , Testes de Toxicidade/normas , Bases de Dados Factuais , Técnicas de Apoio para a Decisão , Humanos , Medição de Risco , Gestão de Riscos , Testes de Toxicidade/estatística & dados numéricos
19.
Environ Toxicol ; 21(4): 425-31, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16841315

RESUMO

N-heterocyclic polycyclic aromatic hydrocarbons (N-PAHs) belong among newly identified classes of environmental pollutants with relatively high toxic potential. N-PAHs have been detected in air, soil, marine environments, and freshwater sediments. The N-PAHs are present at lower concentrations than their nonsubstituted analogues but their greater solubility would lead to greater bioavailibity and potential for toxic effects. Here we present results of acute and chronic toxicity in traditional aquatic invertebrate ecotoxicological model (Daphnia magna) along with assessment of biochemical responses. Studied biomarkers in D. magna exposed to N-heterocyclic derivatives included glutathione levels and activities of detoxication and antioxidative enzymes glutathione S-transferase and glutathione peroxidase. Phenanthrene and 1,10-phenathroline were the most toxic of all tested compounds (EC50 < 6 microM after 48 h exposure) and all tested N-PAHs suppressed reproduction of Daphnia magna. The data suggest that N-PAHs can induce oxidative stress in D. magna. The significant decline of glutathione content was found in animals treated with acridine, 1,10-phenanthroline, benzo(h)quinoline, phenantridine, and phenazine. Significant decrease of GPx activities relative to controls was found for all tested compounds except of phenanthrene and phenazine. Activities of GST increased after exposure to phenanthridine, phenazine, and benzo(h)quinoline, and declined in D. magna treated with phenanthrene (significant at one concentration) or anthracene (not significant). Our results confirmed significant acute as well as chronic toxicities of N-PAHs as well as potential of biochemical parameters to be used as early warning signals of toxicity in Daphnia magna.


Assuntos
Daphnia/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Animais , Biomarcadores/metabolismo , Daphnia/metabolismo , Daphnia/fisiologia , Poluentes Ambientais/química , Feminino , Fertilidade/efeitos dos fármacos , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/química
20.
Clin Exp Immunol ; 143(2): 373-9, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16412063

RESUMO

Common variable immunodeficiency (CVID) is primary hypogammaglobulinaemia with an unknown aetiopathogenesis. Although various abnormalities of T and B cells have been described, their pathogenetic roles are unclear. We determined T and B lymphocyte subsets known to be abnormal in CVID in order to disclose possible relations between numerical abnormalities in those cells. Markers associated with B cell development (CD21, CD27, IgM, IgD) were determined on B lymphocytes (CD19+); T lymphocyte development (CD45RA, CD45RO, CD62L) and activation markers (CD25, CD27, CD28, CD29, CD38, CD57, HLA-DR) were determined on CD4+ and CD8+ T lymphocytes in 42 CVID patients and in 33 healthy controls. Abnormalities in CD4+ T lymphocyte activation markers (increase in CD29, HLA-DR, CD45RO, decrease in CD27, CD62L, CD45RA) were observed particularly in patients with a decreased number of memory (CD27+) and mature (CD21+) B cells (group Ia according to the Freiburg group's classification), while abnormalities observed in CD8+ cells (increase in CD27 and CD28 and decrease in HLA-DR, CD57 and CD38) did not depend upon grouping patients together according to B lymphocyte developmental subpopulations. We observed correlations between immature B cells (IgM+ CD21-) and expression of CD27, CD62L, CD45RA, CD45RO and HLA-DR on CD4+ T cells in CVID patients but not in the control group. The expression of CD27 and CD45RA on CD4+ T lymphocytes, such as the percentage of IgD+ CD27- and IgD+ CD27+ cells in B lymphocytes, showed age dependency to be more significant than in the control group. Our study demonstrates that T and B lymphocyte abnormalities in CVID are partially related to each other. Some of those abnormalities are not definite, but may evolve with age of the patient.


Assuntos
Envelhecimento/imunologia , Linfócitos B/imunologia , Imunodeficiência de Variável Comum/imunologia , Linfócitos T/imunologia , Adulto , Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos B/imunologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Subpopulações de Linfócitos B/imunologia , Biomarcadores/análise , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Imunodeficiência de Variável Comum/classificação , Feminino , Citometria de Fluxo/métodos , Humanos , Imunoglobulina D/imunologia , Imunoglobulina M/imunologia , Ativação Linfocitária/imunologia , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...