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1.
BMC Plant Biol ; 20(1): 467, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33045997

RESUMO

BACKGROUND: This study describes a promising method for understanding how halophytes adapt to extreme saline conditions and to identify populations with greater resistance. Image and colour analyses have the ability to obtain many image parameters and to discriminate between different aspects in plants, which makes them a suitable tool in combination with genetic analysis to study the plants salt tolerance. To the best of our knowledge, there are no publications about the monitoring of halophytic plants by non-destructive methods for identifying the differences between plants that belong to different maternal salinity environments. The aim is to evaluate the ability of image analysis as a non-destructive method and principal component analysis (PCA) to identify the multiple responses of two S. europaea populations, and to determine which population is most affected by different salinity treatments as a preliminary model of selection. RESULTS: Image analysis was beneficial for detecting the phenotypic variability of two S. europaea populations by morphometric and colour parameters, fractal dimension (FD), projected area (A), shoot height (H), number of branches (B), shoot diameter (S) and colour change (ΔE). S was found to strongly positively correlate with both proline content and ΔE, and negatively with chlorophyll content. These results suggest that proline and ΔE are strongly linked to plant succulence, while chlorophyll decreases with increased succulence. The negative correlation between FD and hydrogen peroxide (HP) suggests that when the plant is under salt stress, HP content increases in plants causing a reduction in plant complexity and foliage growth. The PCA results indicate that the greater the stress, the more marked the differences. At 400 mM a shorter distance between the factorial scores was observed. Genetic variability analysis provided evidence of the differences between these populations. CONCLUSIONS: Our non-destructive method is beneficial for evaluating the halophyte development under salt stress. FD, S and ΔE were relevant indicators of plant architecture. PCA provided evidence that anthropogenic saline plants were more tolerant to saline stress. Furthermore, random amplified polymorphic DNA analysis provided a quick method for determining genetic variation patterns between the two populations and provided evidence of genetic differences between them.


Assuntos
Chenopodiaceae/crescimento & desenvolvimento , Chenopodiaceae/genética , Salinidade , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/fisiologia , Fractais , Variação Genética , Genótipo , Polônia
2.
Radiat Environ Biophys ; 59(3): 357-387, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32372284

RESUMO

This work presents an overview of the applications of retrospective dosimetry techniques in case of incorporation of radionuclides. The fact that internal exposures are characterized by a spatially inhomogeneous irradiation of the body, which is potentially prolonged over large periods and variable over time, is particularly problematic for biological and electron paramagnetic resonance (EPR) dosimetry methods when compared with external exposures. The paper gives initially specific information about internal dosimetry methods, the most common cytogenetic techniques used in biological dosimetry and EPR dosimetry applied to tooth enamel. Based on real-case scenarios, dose estimates obtained from bioassay data as well as with biological and/or EPR dosimetry are compared and critically discussed. In most of the scenarios presented, concomitant external exposures were responsible for the greater portion of the received dose. As no assay is available which can discriminate between radiation of different types and different LETs on the basis of the type of damage induced, it is not possible to infer from these studies specific conclusions valid for incorporated radionuclides alone. The biological dosimetry assays and EPR techniques proved to be most applicable in cases when the radionuclides are almost homogeneously distributed in the body. No compelling evidence was obtained in other cases of extremely inhomogeneous distribution. Retrospective dosimetry needs to be optimized and further developed in order to be able to deal with real exposure cases, where a mixture of both external and internal exposures will be encountered most of the times.


Assuntos
Radiação Ionizante , Radiometria/métodos , Animais , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Radioisótopos/farmacocinética
3.
Chem Biol Interact ; 258: 69-78, 2016 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-27545834

RESUMO

This study evaluated the effect of electron beam irradiation on the cytotoxic activity of anthracycline antibiotics such as doxorubicin (DOX), epirubicin (EPI), and dunorubicin (DAU) in human acute lymphoblastic leukemia cell line CCRF-CEM and its multidrug-resistant variant CCRF-VCR1000 cell line characterized by the overexpression of ABCB1 gene. Drugs were irradiated at doses of 10 and 25 kGy. Data from EPR studies proved that the highest concentration of free radicals was found in DOX and that the number of stable free radicals is always greater after irradiation. In in vitro studies, a higher cytotoxic activity of irradiated DOX and EPI in multidrug-resistant CCRF-VCR1000 cells was observed. This tendency was maintained during the storage at 4 °C for 90 days. Changes in CCRF-CEM cells' viability were not dependent on the irradiation status and its dose and were only drug-concentration dependent in all measurement time points. It was proved that increased potency of 25 kGy e-beam irradiated drugs results from their enhanced proapoptotic activity. Apoptotic cell death observed in CCRF-VCR1000 cells treated with irradiated drugs was caspase-8, -9, and -3 dependent and related to the increased Bax/Bcl-2 ratio. No significant differences in the effects of irradiated and non-irradiated drugs on p53 and NFκB transcription factor level and their translocation to the nucleus were noted. Increased activity of the irradiated drugs was not dependent on ABCB1 level.


Assuntos
Apoptose/efeitos dos fármacos , Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/efeitos da radiação , Elétrons , Epirubicina/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Apoptose/efeitos da radiação , Western Blotting , Caspases/metabolismo , Linhagem Celular Tumoral , Daunorrubicina/química , Daunorrubicina/farmacologia , Doxorrubicina/química , Espectroscopia de Ressonância de Spin Eletrônica , Epirubicina/química , Radicais Livres/metabolismo , Humanos , NF-kappa B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Proteína Supressora de Tumor p53/metabolismo
4.
J Intellect Disabil Res ; 60(6): 564-70, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27028200

RESUMO

BACKGROUND: Little is known about depression among women with Rett syndrome (RTT) despite recent advances in knowledge about RTT. In this study, we aimed to establish the prevalence of depression among women with RTT as identified by a screening telephone interview and to explore the clinical factors associated with this. METHODS: The study employed the cross-sectional analysis of data from telephone interviews with carers of 56 women with RTT, using validated questionnaires for assessing mental health problems, challenging behaviour and RTT severity. RESULTS: Scores on the mental health assessment reached the affective/neurotic threshold in eight cases (14.3%). No significant differences were found between those reaching the threshold and those who did not in terms of severity of RTT phenotype, health problems or social circumstances. There was a significant association between screening identified depression and higher lethargy and social withdrawal. CONCLUSIONS: Screening identified depression was found among a sizeable minority of women with RTT. Further investigation is needed to establish a clinically validated prevalence of depression among this group and to identify behavioural features that would lead to prompt psychiatric assessment.


Assuntos
Transtorno Depressivo/fisiopatologia , Síndrome de Rett/fisiopatologia , Adulto , Comorbidade , Estudos Transversais , Transtorno Depressivo/epidemiologia , Feminino , Humanos , Pessoa de Meia-Idade , Prevalência , Síndrome de Rett/epidemiologia , Adulto Jovem
6.
Chem Biol Interact ; 242: 1-12, 2015 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-26362502

RESUMO

One of the main problems of present-day oncology is the ability of neoplastic cells to develop different mechanisms of resistance to chemotherapeutic agent. A natural compound oleanolic acid (OA) was found to be active against many types of neoplastic cells. This paper examines the influence of eight semisynthetic oleanolic acid derivatives on drug-sensitive human acute promyelocytic leukemia cell line HL-60 and its multidrug resistant subline ABCC1 overexpressing HL-60/AR. Viability inhibition, proapoptotic activity, as well as influence on the ABCC1 gene expression level, ability to inhibit the transport function of multidrug resistance associated protein 1 (ABCC1) and to alter its level by the tested compounds, were evaluated. The most potent compounds were DIOXOL (methyl 3,11-dioxoolean-12-en-28-oate) and HIMOXOL (methyl 3-hydroxyimino-11-oxoolean-12-en-28-oate). DIOXOL was most efficient in inducing apoptosis of HL-60 cells. It activated both intrinsic and extrinsic pathways of apoptotic cell death. Proapoptotic properties of DIOXOL were probably related to the significant decrease of p65 NFκB level and inhibition of its translocation to the nucleus. In turn, HIMOXOL was the most potent compound against resistant HL-60/AR cells. It inhibited ABCC1 transport function (short time response) and decreased the level of ABCC1 protein (long time response) as a result of reduction of ABCC1 expression.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Leucemia Promielocítica Aguda/tratamento farmacológico , Ácido Oleanólico/análogos & derivados , Fragmentação do DNA/efeitos dos fármacos , Resistência a Múltiplos Medicamentos , Células HL-60/efeitos dos fármacos , Células HL-60/enzimologia , Humanos , Leucemia Promielocítica Aguda/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Terapia de Alvo Molecular/métodos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Ácido Oleanólico/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Fator de Transcrição RelA/metabolismo
7.
Mol Psychiatry ; 20(10): 1179-87, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26055427

RESUMO

In a positron-emission tomography (PET) study with the ß-amyloid (Aß) tracer [(18)F]-florbetaben, we previously showed that Aß deposition in transgenic mice expressing Swedish mutant APP (APP-Swe) mice can be tracked in vivo. γ-Secretase modulators (GSMs) are promising therapeutic agents by reducing generation of the aggregation prone Aß42 species without blocking general γ-secretase activity. We now aimed to investigate the effects of a novel GSM [8-(4-Fluoro-phenyl)-[1,2,4]triazolo[1,5-a]pyridin-2-yl]-[1-(3-methyl-[1,2,4]thiadiazol-5-yl)-piperidin-4-yl]-amine (RO5506284) displaying high potency in vitro and in vivo on amyloid plaque burden and used longitudinal Aß-microPET to trace individual animals. Female transgenic (TG) APP-Swe mice aged 12 months (m) were assigned to vehicle (TG-VEH, n=12) and treatment groups (TG-GSM, n=12), which received daily RO5506284 (30 mg kg(-1)) treatment for 6 months. A total of 131 Aß-PET recordings were acquired at baseline (12 months), follow-up 1 (16 months) and follow-up 2 (18 months, termination scan), whereupon histological and biochemical analyses of Aß were performed. We analyzed the PET data as VOI-based cortical standard-uptake-value ratios (SUVR), using cerebellum as reference region. Individual plaque load assessed by PET remained nearly constant in the TG-GSM group during 6 months of RO5506284 treatment, whereas it increased progressively in the TG-VEH group. Baseline SUVR in TG-GSM mice correlated with Δ%-SUVR, indicating individual response prediction. Insoluble Aß42 was reduced by 56% in the TG-GSM versus the TG-VEH group relative to the individual baseline plaque load estimates. Furthermore, plaque size histograms showed differing distribution between groups of TG mice, with fewer small plaques in TG-GSM animals. Taken together, in the first Aß-PET study monitoring prolonged treatment with a potent GSM in an AD mouse model, we found clear attenuation of de novo amyloidogenesis. Moreover, longitudinal PET allows non-invasive assessment of individual plaque-load kinetics, thereby accommodating inter-animal variations.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Placa Amiloide/tratamento farmacológico , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Compostos de Anilina/síntese química , Compostos de Anilina/farmacologia , Animais , Estudos de Casos e Controles , Angiopatia Amiloide Cerebral/terapia , Modelos Animais de Doenças , Feminino , Estudos Longitudinais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Placa Amiloide/diagnóstico por imagem , Placa Amiloide/enzimologia , Placa Amiloide/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Estilbenos/síntese química , Estilbenos/farmacologia
8.
Analyst ; 140(7): 2330-5, 2015 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-25700000

RESUMO

Intracellular redox potential is a highly regulated cellular characteristic and is critically involved in maintaining cellular health and function. The dysregulation of redox potential can result in the initiation and progression of numerous diseases. Redox potential is determined by the balance of oxidants and reductants in the cell and also by pH. For this reason a technique for quantitative measurement of intracellular redox potential and pH is highly desirable. In this paper we demonstrate how surface enhanced Raman scattering (SERS) nanosensors can be used for multiplexed measurement of both pH and redox potential in live single cells.


Assuntos
Espaço Intracelular/química , Espaço Intracelular/metabolismo , Nanotecnologia , Análise Espectral Raman , Linhagem Celular , Sobrevivência Celular , Humanos , Concentração de Íons de Hidrogênio , Oxirredução
9.
Radiat Prot Dosimetry ; 164(1-2): 42-5, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25205835

RESUMO

Creating a sustainable network in biological and retrospective dosimetry that involves a large number of experienced laboratories throughout the European Union (EU) will significantly improve the accident and emergency response capabilities in case of a large-scale radiological emergency. A well-organised cooperative action involving EU laboratories will offer the best chance for fast and trustworthy dose assessments that are urgently needed in an emergency situation. To this end, the EC supports the establishment of a European network in biological dosimetry (RENEB). The RENEB project started in January 2012 involving cooperation of 23 organisations from 16 European countries. The purpose of RENEB is to increase the biodosimetry capacities in case of large-scale radiological emergency scenarios. The progress of the project since its inception is presented, comprising the consolidation process of the network with its operational platform, intercomparison exercises, training activities, proceedings in quality assurance and horizon scanning for new methods and partners. Additionally, the benefit of the network for the radiation research community as a whole is addressed.


Assuntos
Bioensaio/métodos , Planejamento em Desastres/organização & administração , Lesões por Radiação/prevenção & controle , Monitoramento de Radiação/métodos , Proteção Radiológica/métodos , Liberação Nociva de Radioativos/prevenção & controle , Emergências , Europa (Continente) , Humanos , Exposição à Radiação/prevenção & controle , Gestão da Segurança/organização & administração
10.
Radiat Prot Dosimetry ; 151(4): 621-5, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22923244

RESUMO

In Europe, a network for biological dosimetry has been created to strengthen the emergency preparedness and response capabilities in case of a large-scale nuclear accident or radiological emergency. Through the RENEB (Realising the European Network of Biodosimetry) project, 23 experienced laboratories from 16 European countries will establish a sustainable network for rapid, comprehensive and standardised biodosimetry provision that would be urgently required in an emergency situation on European ground. The foundation of the network is formed by five main pillars: (1) the ad hoc operational basis, (2) a basis of future developments, (3) an effective quality-management system, (4) arrangements to guarantee long-term sustainability and (5) awareness of the existence of RENEB. RENEB will thus provide a mechanism for quick, efficient and reliable support within the European radiation emergency management. The scientific basis of RENEB will concurrently contribute to increased safety in the field of radiation protection.


Assuntos
Proteção Radiológica , Liberação Nociva de Radioativos , Defesa Civil , Emergências , Europa (Continente) , Humanos , Liberação Nociva de Radioativos/prevenção & controle
11.
Radiat Prot Dosimetry ; 147(4): 573-92, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21183550

RESUMO

The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements.


Assuntos
Monitoramento de Radiação , Radiação Ionizante , Radiometria/métodos , Carga Corporal (Radioterapia) , Humanos , Doses de Radiação , Estudos Retrospectivos , Medição de Risco
12.
J Hazard Mater ; 167(1-3): 52-63, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19179007

RESUMO

The factorial design of experiments and desirability function approach has been applied for multi-response optimization in pervaporation separation process. Two organic aqueous solutions were considered as model mixtures, water/acetonitrile and water/ethanol mixtures. Two responses have been employed in multi-response optimization of pervaporation, total permeate flux and organic selectivity. The effects of three experimental factors (feed temperature, initial concentration of organic compound in feed solution, and downstream pressure) on the pervaporation responses have been investigated. The experiments were performed according to a 2(3) full factorial experimental design. The factorial models have been obtained from experimental design and validated statistically by analysis of variance (ANOVA). The spatial representations of the response functions were drawn together with the corresponding contour line plots. Factorial models have been used to develop the overall desirability function. In addition, the overlap contour plots were presented to identify the desirability zone and to determine the optimum point. The optimal operating conditions were found to be, in the case of water/acetonitrile mixture, a feed temperature of 55 degrees C, an initial concentration of 6.58% and a downstream pressure of 13.99 kPa, while for water/ethanol mixture a feed temperature of 55 degrees C, an initial concentration of 4.53% and a downstream pressure of 9.57 kPa. Under such optimum conditions it was observed experimentally an improvement of both the total permeate flux and selectivity.


Assuntos
Compostos Orgânicos/química , Purificação da Água/métodos , Acetonitrilas , Análise de Variância , Etanol , Membranas Artificiais , Permeabilidade , Pressão , Soluções , Temperatura , Ultrafiltração , Água
13.
J Radiol Prot ; 28(4): 499-509, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19029584

RESUMO

Regulatory cooperation between the Norwegian Radiation Protection Authority and the Federal Medical Biological Agency (FMBA) of the Russian Federation has the overall goal of promoting improvements in radiation protection in Northwest Russia. One of the projects in this programme has the objectives to review and improve the existing medical emergency preparedness capabilities at the sites for temporary storage of spent nuclear fuel and radioactive waste. These are operated by SevRAO at Andreeva Bay and in Gremikha village on the Kola Peninsula. The work is also intended to provide a better basis for regulation of emergency response and medical emergency preparedness at similar facilities elsewhere in Russia. The purpose of this paper is to present the main results of that project, implemented by the Burnasyan Federal Medical Biophysical Centre. The first task was an analysis of the regulatory requirements and the current state of preparedness for medical emergency response at the SevRAO facilities. Although Russian regulatory documents are mostly consistent with international recommendations, some distinctions lead to numerical differences in operational intervention criteria under otherwise similar conditions. Radiological threats relating to possible accidents, and related gaps in the regulation of SevRAO facilities, were also identified. As part of the project, a special exercise on emergency medical response on-site at Andreeva Bay was prepared and carried out, and recommendations were proposed after the exercise. Following fruitful dialogue among regulators, designers and operators, special regulatory guidance has been issued by FMBA to account for the specific and unusual features of the SevRAO facilities. Detailed sections relate to the prevention of accidents, and emergency preparedness and response, supplementing the basic Russian regulatory requirements. Overall it is concluded that (a) the provision of medical and sanitary components of emergency response at SevRAO facilities is a priority task within the general system of emergency preparedness; (b) there is an effective and improving interaction between SevRAO and the local medical institutions of FMBA and other territorial medical units; (c) the infrastructure of emergency response at SevRAO facilities has been created and operates within the framework of Russian legal and normative requirements. Further proposals have been made aimed at increasing the effectiveness of the available system of emergency preparedness and response, and to promote interagency cooperation.


Assuntos
Defesa Civil/legislação & jurisprudência , Serviços Médicos de Emergência/legislação & jurisprudência , Resíduos Industriais/prevenção & controle , Monitoramento de Radiação/legislação & jurisprudência , Proteção Radiológica/legislação & jurisprudência , Resíduos Radioativos/prevenção & controle , Gerenciamento de Resíduos/legislação & jurisprudência , Regulamentação Governamental , Humanos , Reatores Nucleares/legislação & jurisprudência , Federação Russa , Gestão da Segurança/legislação & jurisprudência
14.
J Environ Radioact ; 99(9): 1474-83, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18550231

RESUMO

The ERICA Integrated Approach requires that a risk assessment screening dose rate is defined for the risk characterisation within Tiers 1 and 2. At Tier 3, no numerical screening dose rate is used, and the risk characterisation is driven by methods that can evaluate the possible effects of ionising radiation on reproduction, mortality and morbidity. Species sensitivity distribution has been used to derive the ERICA risk assessment predicted no-effect dose rate (PNEDR). The method used was based on the mathematical processing of data from FRED (FASSET radiation effects database merged with the EPIC database to form FREDERICA) and resulted in a PNEDR of 10 microGy/h. This rate was assumed to ascribe sufficient protection of all ecosystems from detrimental effects on structure and function under chronic exposure. The value was weighed against a number of points of comparison: (i) PNEDR values obtained by application of the safety factor method, (ii) background levels, (iii) dose rates triggering effects on radioactively contaminated sites and (iv) former guidelines from literature reviews. In Tier 3, the effects analysis must be driven by the problem formulation and is thus highly case specific. Instead of specific recommendations on numeric values, guidance on the sorts of methods that may be applied for refined effect analysis is provided and illustrated.


Assuntos
Ecossistema , Monitoramento de Radiação/métodos , Radiação Ionizante , Medição de Risco/métodos , Animais , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Desenvolvimento Vegetal , Plantas/efeitos da radiação , Literatura de Revisão como Assunto
15.
Radiats Biol Radioecol ; 42(6): 595-9, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12530132

RESUMO

The most commonly used indicators of ionizing radiation exposure are cytogenetic measures and survival parameters. All these methods have their advantages, disadvantages and uncertainties, such that better biological estimators of the absorbed dose, especially in the low dose range, are being sought. In this study we analyzed apoptosis and several proteins involved in the regulation of apoptosis as possible indicators of irradiation after relatively small doses (0.1-2 Gy) of X-rays. The studies were carried out in seven lymphoid cell lines: two mouse lymphoma L5178Y, the human pre-B cell leukemia Reh, and four human Epstein-Barr virus-transformed lymphoid cell lines (two apparently normal and two Ataxia-telangiectasia (AT)). We detected apoptosis with the in situ terminal deoxynucleotidyl transferase assay and flow cytometry, and measured the expression of several apoptotic-regulatory proteins (Bcl-2, Bax, Bclx, NF kappa B) with Western blotting. The cytokinesis-block micronucleus assay, comet assay as a measure of DNA damage, and trypan blue survival test were also done for comparison Although for the most of examined parameters of radiation sensitivity: i.e. micronucleus assay, trypan blue test and percentage of apoptosis--there were observed clear dose-effect relationships for all cell lines examined, we did not find agreement between values for these measured parameters. There are marked differences in both timing of apoptosis and percentage of apoptotic cells. Variation in the apoptotic fraction in the controls for different sets of experiments is not very pronounced. There is however considerable variation for the same parameters in irradiated cells, possibly due to their cell cycle status during irradiation, as the cultures were not synchronized. Overall, neither the numbers of apoptotic cells nor the expression of apoptosis-related proteins, nor DNA repair can serve as dose estimators or sensors for these lines, but still these parameters can give valuable supplementary information about radiation sensitivity.


Assuntos
Biomarcadores , Linfócitos/efeitos da radiação , Tolerância a Radiação , Animais , Western Blotting , Linhagem Celular Transformada , Ensaio Cometa , Dano ao DNA , Humanos , Linfócitos/metabolismo , Camundongos , Testes para Micronúcleos , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Células Tumorais Cultivadas , Raios X
16.
Int J Radiat Biol ; 77(3): 269-80, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11258841

RESUMO

PURPOSE: To examine the possible associations between radiation sensitivity to doses 2 Gy, and such features of lymphoid cell responses as apoptosis, expression of apoptosis regulatory proteins (Bcl-2 family) and cell cycle progression in relation to biological dosimetry. MATERIALS AND METHODS: The cell lines examined were: Epstein Barr virus transformed lymphoid ataxia-telangiectasia (AT) cell lines, GM00717C, homozygous, and GM00736A, heterozygous, for ATM; human pro-B lymphoblastic leukaemia, Reh; murine L5178Y lymphoma sublines, LY-R and LY-S. Assays performed following X-irradiation with doses from 0.1 to 2 Gy were: terminal deoxyribonucleotidyl transferase (TdT) assay to measure apoptotic fraction, DNA content analysis by flow cytometry to assess cell cycle distribution, trypan blue exclusion test to determine cell viability, cytochalasin block micronucleus assay to assess cytogenetic damage, and Western blotting to detect proteins from the Bcl-2 family. RESULTS: The cell lines in the study were of different but rather high radiation sensitivity, which was unrelated to their propensity to undergo apoptosis or micronucleus frequency. The expression of apoptotic regulatory proteins from the Bcl-2 family (constitutive and expressed 4 or 24 h after irradiation) was not related to radiation sensitivity. CONCLUSION: None of the simple predictive tests used in the study, alone or evaluated together was suitable for detection of radiation hypersensitivity although cells known to be hypersensitive (LY-S and GM00717C) were included in the analysis.


Assuntos
Linfócitos/efeitos da radiação , Tolerância a Radiação , Animais , Apoptose , Biomarcadores , Contagem de Células , Ciclo Celular/efeitos da radiação , Linhagem Celular , Sobrevivência Celular/efeitos da radiação , DNA/análise , DNA/efeitos da radiação , Relação Dose-Resposta à Radiação , Citometria de Fluxo , Humanos , Marcação In Situ das Extremidades Cortadas , Linfócitos/metabolismo , Linfócitos/patologia , Camundongos , Testes para Micronúcleos , Valor Preditivo dos Testes , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
17.
Wiad Parazytol ; 47 Suppl 1: 107-12, 2001.
Artigo em Polonês | MEDLINE | ID: mdl-16897960

RESUMO

The effectiveness of neonatal screening for anti-Toxoplasma IgM or IgA and IgM specific antibodies followed by an intensive anti-parasitic therapy for a prevention of clinical and immunological reactivations of congenital infection was studied. Thirty-five congenitally infected infants were included into clinical and serological follow-up. The children were mostly asymptomatic at birth or they expressed some non-specific reversible clinical abnormalities in neonatal period. Clinically overt toxoplasmosis occurred in 10 patients, including one infant with a severe form; 2 children had co-existing CMV infections. During the follow-up period, no clinical relapses were reported. Asymptomatic immunological rebounds of IgG or of IgG and IgA specific antibodies were observed in 16 patients. Anti-parasitic treatment initiated soon after birth seems to be promising in a prevention of early clinical sequelae of congenital T. gondii infection.


Assuntos
Doenças do Sistema Nervoso Central/diagnóstico , Imunoglobulina M/sangue , Triagem Neonatal/organização & administração , Complicações Parasitárias na Gravidez/diagnóstico , Complicações Parasitárias na Gravidez/prevenção & controle , Toxoplasmose Congênita/diagnóstico , Toxoplasmose Congênita/prevenção & controle , Animais , Anticorpos Antiprotozoários/sangue , Doenças do Sistema Nervoso Central/prevenção & controle , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Polônia/epidemiologia , Gravidez , Avaliação de Programas e Projetos de Saúde , Toxoplasma , Resultado do Tratamento
18.
J Exp Bot ; 51(345): 703-11, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10938862

RESUMO

The exposure of dark-grown Pharbitis nil seedlings to continuous R induces a rapid decrease in PHYA mRNA abundance with a half-life of about 2 h. A 5 min R pulse also induces this decline, and the effect is partially reversible by subsequent FR irradiation, confirming that the regulation of expression is mediated via the Pfr form of a phytochrome. When de-etiolated seedlings are returned to darkness after a W photoperiod, PHYA mRNA slowly reaccumulates from 20% to 50% of the dark level within 24 h. The rate of reaccumulation is greatly accelerated by the removal of Pfr with a FR pulse, resulting in reaccumulation to 100% within approximately 11 h. Without FR irradiation PHYA mRNA expression remains fully repressed for at least 11 h after the end of the photoperiod, suggesting that the controlling Pfr is highly stable.


Assuntos
Regulação da Expressão Gênica de Plantas , Luz , Fitocromo/metabolismo , Plantas/genética , Sequência de Aminoácidos , Sequência de Bases , Escuridão , Dados de Sequência Molecular , Fotoperíodo , Fitocromo/genética , Fitocromo A , Plantas/metabolismo , RNA Mensageiro/análise
19.
Radiat Environ Biophys ; 39(1): 33-40, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10789893

RESUMO

We examined apoptosis and expression of p53, E2F-1, bax, bclx(L) and bc12 proteins in two L5178Y (LY) murine lymphoma sublines, LY-R and LY-S, which differ in radiosensitivity and double-strand break (DSB) repair. Both sublines are heterozygous for a p53 mutation in codon 170 that precludes the transactivation function. Accordingly, there is no G1/S arrest after irradiation. We found that there is no change in expression of E2F-1, bax, bclx(L) or bc12 proteins in both LY sublines after x-irradiation. LY-R cells do not constitutively express bc12, whereas both sublines show high bax content. Radiation induces delayed apoptosis to a greater extent in LY-S than in LY-R cells. The apoptosis can be seen 24 h after irradiation (2 Gy) of LY-S cells, with a maximum at 48 h. LY-R cells need 5 Gy and 72 h post-irradiation incubation to show marked apoptosis (identified by the TUNEL method). The reported observations support the assumption that differential radiosensitivity of LY sublines is associated with the induction of apoptosis that is not related to transactivation by p53 and is primarily related to differential DNA repair ability.


Assuntos
Apoptose/efeitos da radiação , Proteínas de Transporte , Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Genes p53 , Mutação , Animais , Ciclo Celular/efeitos da radiação , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Genes p53/genética , Leucemia L5178 , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Tolerância a Radiação , Proteína 1 de Ligação ao Retinoblastoma , Fatores de Transcrição/genética , Células Tumorais Cultivadas , Raios X , Proteína X Associada a bcl-2 , Proteína bcl-X
20.
J Photochem Photobiol B ; 58(2-3): 170-4, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11233646

RESUMO

Cells from the mouse lymphoma cell line L5178Y-R were exposed to blue light from phototherapy lamps in the presence of solutions of 160 microM bilirubin supplemented with serum albumin. HPLC analysis showed that the bilirubin solution was photooxidised as a function of increasing light dose. The cells were stained with trypan blue to score necrosis, and apoptosis was assayed by the terminal deoxynucleotide transferase assay (TdT) or by studying the nuclear structure in cells stained with propidium iodide. A rapidly developing apoptosis was observed after light doses killing 60-80% of the cells as judged from the trypan blue exclusion test. The fraction of apoptotic cells was smaller than the fraction of necrotic cells. Exposure of the cells to fractions of light at a high dose rate was compared to the effect of the same total dose at a lower dose rate given as a single fraction. No large differences were found, however, there was a tendency of a higher degree of necrosis as well as apoptosis in the cells receiving the light in fractions at a high dose rate.


Assuntos
Bilirrubina/farmacologia , Linfoma/terapia , Fototerapia , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Linfoma/patologia , Camundongos , Fotobiologia , Fármacos Fotossensibilizantes/farmacologia , Células Tumorais Cultivadas
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