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1.
World J Microbiol Biotechnol ; 33(6): 112, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28470425

RESUMO

The study of prokaryotic life in high temperature environments viz., geothermal areas, hot, acidic geysers and undersea hydrothermal vents has revealed the existence of thermophiles (or hyperthermophiles). These microorganisms possess various stress adaptation mechanisms which enable them to bypass multiple physical and chemical barriers for survival. The discovery of radiation resistant thermophile Deinococcus geothermalis has given new insights into the field of radiation microbiology. The ability of radiation resistant thermophiles to deal with the lethal effects of ionizing radiations like DNA damage, oxidative bursts and protein damage has made them a model system for exobiology and interplanetary transmission of life. They might be an antiquity of historical transport process that brought microbial life on Earth. These radiation resistant thermophiles are resistant to desiccation as well and maintain their homeostasis by advance DNA repair mechanisms, reactive oxygen species (ROS) detoxification system and accumulation of compatible solutes. Moreover, engineered radioresistant thermophilic strains are the best candidate for bioremediation of radionuclide waste while the extremolytes produced by these organisms may have predicted therapeutic uses. So, the present article delineate a picture of radiation resistance thermophiles, their adaptive mechanisms to evade stress viz., radiation and desiccation, their present applications along with new horizons in near future.


Assuntos
Archaea/fisiologia , Archaea/efeitos da radiação , Bactérias/efeitos da radiação , Fenômenos Fisiológicos Bacterianos/efeitos da radiação , Temperatura Alta , Actinobacteria/fisiologia , Actinobacteria/efeitos da radiação , Bactérias/genética , Fenômenos Fisiológicos Bacterianos/genética , Biodegradação Ambiental , Cianobactérias/fisiologia , Cianobactérias/efeitos da radiação , Dano ao DNA/efeitos da radiação , Reparo do DNA , Deinococcus/genética , Deinococcus/fisiologia , Deinococcus/efeitos da radiação , Microbiologia Ambiental , Exobiologia , Halobacterium/fisiologia , Halobacterium/efeitos da radiação , Pyrococcus/fisiologia , Pyrococcus/efeitos da radiação , Radiação Ionizante , Espécies Reativas de Oxigênio/efeitos da radiação , Explosão Respiratória/efeitos da radiação , Estresse Fisiológico , Sulfolobus/fisiologia , Sulfolobus/efeitos da radiação , Thermococcus/fisiologia , Thermococcus/efeitos da radiação
2.
New Phytol ; 213(4): 1667-1681, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28164334

RESUMO

Recent studies indicate that the ETHYLENE RESPONSE FACTOR VII (ERF-VII) transcription factor is an important regulator of osmotic and hypoxic stress responses in plants. However, the molecular mechanism of ERF-VII-mediated transcriptional regulation remains unclear. Here, we investigated the role of ERF74 (a member of the ERF-VII protein family) by examining the abiotic stress tolerance of an ERF74 overexpression line and a T-DNA insertion mutant using flow cytometry, transactivation and electrophoretic mobility shift assays. 35S::ERF74 showed enhanced tolerance to drought, high light, heat and aluminum stresses, whereas the T-DNA insertion mutant erf74 and the erf74;erf75 double mutant displayed higher sensitivity. Using flow cytometry analysis, we found that erf74 and erf74;erf75 lines lack the reactive oxygen species (ROS) burst in the early stages of various stresses, as a result of the lower expression level of RESPIRATORY BURST OXIDASE HOMOLOG D (RbohD). Furthermore, ERF74 directly binds to the promoter of RbohD and activates its expression under different abiotic stresses. Moreover, induction of stress marker genes and ROS-scavenging enzyme genes under various stress conditions is dependent on the ERF74-RbohD-ROS signal pathway. We propose a pathway that involves ERF74 acting as an on-off switch controlling an RbohD-dependent mechanism in response to different stresses, subsequently maintaining hydrogen peroxide (H2 O2 ) homeostasis in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , NADPH Oxidases/metabolismo , Explosão Respiratória , Estresse Fisiológico , Arabidopsis/genética , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Sequência de Bases , Secas , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Genes Dominantes , Luz , Modelos Biológicos , Mutação/genética , Fenótipo , Pigmentação/efeitos da radiação , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Ligação Proteica/efeitos da radiação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória/efeitos da radiação , Estresse Fisiológico/genética , Estresse Fisiológico/efeitos da radiação , Ativação Transcricional/genética
3.
Plant Physiol ; 172(3): 1465-1479, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27621425

RESUMO

Pyridine nucleotides, such as NAD, are crucial redox carriers and have emerged as important signaling molecules in stress responses. Previously, we have demonstrated in Arabidopsis (Arabidopsis thaliana) that the inducible NAD-overproducing nadC lines are more resistant to an avirulent strain of Pseudomonas syringae pv tomato (Pst-AvrRpm1), which was associated with salicylic acid-dependent defense. Here, we have further characterized the NAD-dependent immune response in Arabidopsis. Quinolinate-induced stimulation of intracellular NAD in transgenic nadC plants enhanced resistance against a diverse range of (a)virulent pathogens, including Pst-AvrRpt2, Dickeya dadantii, and Botrytis cinerea Characterization of the redox status demonstrated that elevated NAD levels induce reactive oxygen species (ROS) production and the expression of redox marker genes of the cytosol and mitochondrion. Using pharmacological and reverse genetics approaches, we show that NAD-induced ROS production functions independently of NADPH oxidase activity and light metabolism but depends on mitochondrial respiration, which was increased at higher NAD. We further demonstrate that NAD primes pathogen-induced callose deposition and cell death. Mass spectrometry analysis reveals that NAD simultaneously induces different defense hormones and that the NAD-induced metabolic profiles are similar to those of defense-expressing plants after treatment with pathogen-associated molecular patterns. We thus conclude that NAD triggers metabolic profiles rather similar to that of pathogen-associated molecular patterns and discuss how signaling cross talk between defense hormones, ROS, and NAD explains the observed resistance to pathogens.


Assuntos
Arabidopsis/imunologia , NAD/metabolismo , Imunidade Vegetal , Arabidopsis/microbiologia , Arabidopsis/efeitos da radiação , Morte Celular/efeitos da radiação , Análise Discriminante , Resistência à Doença/imunologia , Espaço Intracelular/metabolismo , Análise dos Mínimos Quadrados , Luz , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Modelos Biológicos , NADPH Oxidases/metabolismo , Nucleotídeos/metabolismo , Estresse Oxidativo/efeitos da radiação , Moléculas com Motivos Associados a Patógenos/metabolismo , Fenótipo , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Plantas/metabolismo , Imunidade Vegetal/efeitos da radiação , Folhas de Planta/citologia , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Piridinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória/efeitos da radiação , Ácido Salicílico/metabolismo
4.
J Biophotonics ; 9(11-12): 1180-1188, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27243910

RESUMO

Low-level laser therapy (LLLT) is known to enhance mitochondrial electron transfer and ATP production; thus, this study asked whether LLLT could stimulate the oxidative burst in human neutrophils (PMN) and improve their ability to kill microorganisms. Blood from healthy human subjects was collected and PMN were isolated from the samples. PMN were treated in vitro with 660 nm or 780 nm CW laser light at 40 mW power and increasing energies up to 19.2 J and were subsequently incubated with Candida albicans cells. Generation of hydroxyl radicals, hypochlorite anions and superoxide anions by PMN were checked using fluorescent probes and chemiluminescence assays; a microbicidal activity assay against C. albicans was also performed. LLLT excited PMN to a higher functional profile, which was translated as superior production of reactive oxygen species (ROS) and increased fungicidal capacity. The most efficacious energy was 19.2 J and, interestingly, the 660 nm light was even more efficacious than 780 nm at increasing the respiratory burst of PMN and the fungicidal capacity. Human neutrophils (PMN) were stimulated in vitro with 660 nm or 780 nm CW laser light at 40 mW of power and a total energy of 19.2 J. Low-level laser therapy (LLLT) excited PMN to a higher functional profile, which was translated as a superior production of reactive oxygen species (ROS) such as hydroxyl radicals (HO• ) and hypochlorite anions (ClO- ) (Figure) and increased fungicidal capacity against Candida albicans cells.


Assuntos
Candida albicans , Terapia com Luz de Baixa Intensidade , Neutrófilos/efeitos da radiação , Explosão Respiratória/efeitos da radiação , Humanos , Neutrófilos/imunologia , Espécies Reativas de Oxigênio/metabolismo
5.
Int J Radiat Biol ; 90(7): 515-26, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24597753

RESUMO

PURPOSE: Concern regarding radiation effects on human health continues to increase worldwide. Given that infection is a major cause of morbidity and mortality after exposure, the aim of this study was to evaluate decrements in immune cell populations using a mammalian model subjected to a live bacterial infection. MATERIALS AND METHODS: C57BL/6 mice were exposed to total-body irradiation (TBI) with 3 Gy protons (70 cGy/min). One, 2, 4, 8 or 16 days later, subsets of mice were injected intraperitoneally with live Escherichia coli [055:K59(B5)]. Control groups received no radiation and vehicle (no bacteria). The mice were euthanized for analyses 90-120 min after injection of the bacteria. RESULTS: There were no unexpected effects of radiation or E. coli alone. Despite dramatic radiation-induced decreases in all leukocyte populations in both the blood and spleen, irradiated mice were still able to respond to an immune challenge based on capacity to generate an oxidative burst and secrete inflammatory cytokines, i.e., tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). However, these responses were generally elevated above control values. CONCLUSIONS: Together, these results suggest the possibility for enhanced inflammation-associated tissue injury and increased risk for chronic inflammation.


Assuntos
Escherichia coli/fisiologia , Viabilidade Microbiana , Irradiação Corporal Total/efeitos adversos , Animais , Tamanho Corporal/imunologia , Tamanho Corporal/efeitos da radiação , Citocinas/metabolismo , Relação Dose-Resposta à Radiação , Contagem de Eritrócitos , Feminino , Regulação da Expressão Gênica/imunologia , Regulação da Expressão Gênica/efeitos da radiação , Antígenos de Histocompatibilidade Classe II/metabolismo , Leucócitos/citologia , Leucócitos/imunologia , Leucócitos/efeitos da radiação , Camundongos , Camundongos Endogâmicos C57BL , Tamanho do Órgão/imunologia , Tamanho do Órgão/efeitos da radiação , Contagem de Plaquetas , Explosão Respiratória/imunologia , Explosão Respiratória/efeitos da radiação , Baço/citologia , Baço/imunologia , Baço/efeitos da radiação
6.
Free Radic Res ; 47(10): 811-20, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23869974

RESUMO

This study evaluated liver from C57BL/6 mice irradiated with low-dose/low-dose-rate (LDR) γ-rays (0.01 Gy, 0.03 cGy/h), with and without subsequent exposure to acute 2 Gy gamma or proton radiation. Analyses were performed on day 56 post-exposure. Expression patterns of apoptosis-related genes were strikingly different among irradiated groups compared with 0 Gy (p < 0.05). Two genes were affected in the Gamma group, whereas 10 were modified in the LDR + Gamma group. In Proton and LDR + Proton groups, there were six and 12 affected genes, respectively. Expression of genes in the Gamma (Traf3) and Proton (Bak1, Birc2, Birc3, Mcl1) groups was no longer different from 0 Gy control group when mice were pre-exposed to LDR γ-rays. When each combined regimen was compared with the corresponding group that received acute radiation alone, two genes in the LDR + Gamma group and 17 genes in the LDR + Proton group were modified; greatest effect was on Birc2 and Nol3 (> 5-fold up-regulated by LDR + Protons). Oxygen radical production in livers from the LDR + Proton group was higher in LDR, Gamma, and LDR + Gamma groups (p < 0.05 vs. 0 Gy), but there were no differences in phagocytosis of E. coli. Sections stained with hematoxylin and eosin (H&E) suggested more inflammation, with and without necrosis, in some irradiated groups. The data demonstrate that response to acute radiation is dependent on radiation quality and regimen and that some LDR γ-ray-induced modifications in liver response were still evident nearly 2 months after exposure.


Assuntos
Raios gama , Fígado/efeitos da radiação , Prótons , Animais , Apoptose/efeitos da radiação , Relação Dose-Resposta à Radiação , Feminino , Expressão Gênica/efeitos da radiação , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória/efeitos da radiação
7.
Fish Shellfish Immunol ; 21(1): 70-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16376572

RESUMO

In order to study the sensitivity of two fish species, carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss), to the immunomodulatory effects of ultraviolet B (UVB) radiation, the fish were exposed to a single UVB dose of 50, 250, 500 or 1,000 mJ cm(-2). These species represent different phylogenetic groups of fish, and they differ also in their behaviour inhabitating often dark and turbid (carp) or clear and transparent waters (salmonids). Immune responses were studied on day 1 post-irradiation. Unexposed fish, and fish exposed to radiation depleted of UV wavelengths served as controls. UVB irradiation markedly enhanced the blood respiratory burst and cytotoxic activity in carp, but in the head kidney these parameters were significantly suppressed. Rainbow trout respiratory burst was affected only after exposure with the highest dose of UVB. Lymphopenia and granulophilia were noted in both fish blood after exposure. This study indicates that UVB irradiation modulates immune functions in both fish species studied, and that rainbow trout is more tolerant than carp against UVB. Fish are clearly adapted to the environmental UVB levels prevailing in their usual living habitats, but are also a target of undesired effects of UVB on immune functions whenever exposed to increased radiation levels.


Assuntos
Carpas/imunologia , Sistema Imunitário/efeitos da radiação , Oncorhynchus mykiss/imunologia , Raios Ultravioleta , Animais , Testes Imunológicos de Citotoxicidade/veterinária , Relação Dose-Resposta à Radiação , Hidrocortisona/sangue , Imunoglobulina M/sangue , Rim/efeitos da radiação , Leucócitos/imunologia , Leucócitos/efeitos da radiação , Medições Luminescentes/veterinária , Explosão Respiratória/efeitos da radiação , Espectrofotometria Ultravioleta/veterinária
8.
Biotechnol Bioeng ; 85(7): 714-21, 2004 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-14991649

RESUMO

This work aims to detect the two signal events in the elicitation of plant defense responses and secondary metabolism in plant cell cultures by low-energy ultrasound (US), transient production of reactive oxygen species (ROS) or the oxidative burst and jasmonic acid (JA) biosynthesis, and examine their influence on secondary metabolism. Experiments were carried out in Taxus chinensis cell suspension culture which produces the anticancer diterpenoid Taxol (paclitaxel). The culture was exposed to low-frequency US for a short period of time (2 min). At sufficiently high US power levels the US exposure significantly enhanced the Taxol production and slightly depressed cell growth and viability. The US exposure induced transient production of O(2)*- and H(2)O(2) and an increase in the intracellular JA level as well as the activities of enzymes for JA synthesis, lipoxygenase (LOX), and allene oxide synthase (AOS). Inhibition of the ROS production by putative ROS scavengers or the JA accumulation by LOX inhibitors effectively suppressed the US-stimulated Taxol production. Inhibition of the ROS production also suppressed the US-induced JA accumulation. These results suggest that oxidative burst is an upstream event to JA accumulation, and both ROS from the oxidative burst and JA from the LOX pathway are key signal elements in the elicitation of Taxol production of T. chinensis cells by low-energy US.


Assuntos
Técnicas de Cultura de Células/métodos , Ciclopentanos/metabolismo , Paclitaxel/biossíntese , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória/fisiologia , Taxus/metabolismo , Taxus/efeitos da radiação , Divisão Celular/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Ativação Enzimática , Oxirredutases Intramoleculares/metabolismo , Lipoxigenase/metabolismo , Oxilipinas , Caules de Planta/citologia , Caules de Planta/metabolismo , Explosão Respiratória/efeitos da radiação , Transdução de Sinais/fisiologia , Transdução de Sinais/efeitos da radiação , Taxus/citologia , Ultrassom
9.
Strahlenther Onkol ; 179(1): 45-9, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12540984

RESUMO

BACKGROUND: A recent study has demonstrated that radiation therapy with single doses of up to 32 Gy has only a minor effect on neutrophilic granulocyte function. In clinical practice, by contrast, fractionated irradiation is applied. Therefore, the aim of the current study was to verify the influence of fractionated radiation therapy on granulocyte function. MATERIAL AND METHODS: Density gradient-purified granulocytes of voluntary healthy donors were used for all experiments. Granulocytes were kept in RPMI 1640 without fetal calf serum, incubated for 48 h and irradiated. Their function was assessed by measuring luminol-enhanced chemiluminescence after stimulation with phorbol myristate acid (PMA). All tests were performed at least five times. RESULTS: Relative changes (any reactive oxygen species [ROS] release before stimulation was defined as being equal to 100%) in ROS release increased after stimulation wit PMA (mean +/- SD): 0 Gy: 785 +/-, 462.2%; 2 Gy: 704.3 +/- 388.1%; 6 Gy: 1,360.3 +/- 710.5%; 12 Gy: 1,119.4 +/- 581.1%; 18 Gy: 1,087.3 +/- 622.4; 6 Gy (3 x 2 Gy): 279.4 +/- 201.1%; 12 Gy (6 x 2 Gy): 278.8 +/- 175.3%; 18 Gy (9 x 2 Gy): 84.2 +/- 41.5%. Comparing relative changes in ROS release after PMA stimulation, the differences between 0, 2, 6, 12, 18 Gy, and 6 Gy (3 x 2 Gy), 12 Gy (6 x 2 Gy), 18 Gy (9 x 2 Gy), and between 6 Gy (3 x 2 Gy), 12 Gy (6 x 2 Gy) and 18 Gy (9 x 2 Gy) proved to be significant (all p < 0.005). CONCLUSION: The study shows, that clinically used fractionated irradiation has an impact on granulocyte function, but contrary to common assumption, it is not to total dose itself but rather the fractionation which influences granulocyte function. This could have a major clinical impact on radiation treatment schemes especially for benign diseases or anti-inflammatory treatment.


Assuntos
Quimiotaxia de Leucócito/efeitos da radiação , Ativação de Neutrófilo/efeitos da radiação , Neutrófilos/efeitos da radiação , Explosão Respiratória/efeitos da radiação , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Humanos , Técnicas In Vitro , Medições Luminescentes , Acetato de Tetradecanoilforbol
10.
Bioelectromagnetics ; 23(8): 599-606, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12395415

RESUMO

Comparative investigation of the susceptibility of intact and primed neutrophils of the NMRI strain mice to low intensity millimeter wave (mm wave) irradiation (41.95 GHz) was performed. The specific absorption rate was 0.45 W/kg. Isolated neutrophils were primed by a chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) at a subthreshold concentration of 10 nM for 20 min, and then the cells were activated by 1 microM fMLP. Production of the reactive oxygen species (ROS) was estimated by the luminol dependent chemiluminescence technique. It was found that the preliminary mm wave irradiation of the resting cells at 20 degrees C did not act on the ROS production induced by the chemotactic peptide. The exposure of the primed cells results in a subsequent increase in the fMLP response. Therefore, the primed neutrophils are susceptible to the mm waves. Specific inhibitors of the protein kinases abolished the mm wave effect on the primed cells. The data indicate that protein kinases actively participate in transduction of the mm wave signal to effector molecules involved in neutrophil respiratory burst.


Assuntos
Micro-Ondas , N-Formilmetionina Leucil-Fenilalanina/metabolismo , N-Formilmetionina Leucil-Fenilalanina/efeitos da radiação , Neutrófilos/imunologia , Neutrófilos/efeitos da radiação , Proteínas Quinases/metabolismo , Adjuvantes Imunológicos/efeitos da radiação , Animais , Linhagem Celular , Relação Dose-Resposta à Radiação , Masculino , Camundongos , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Proteínas Quinases/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Oxigênio/efeitos da radiação , Explosão Respiratória/efeitos dos fármacos , Explosão Respiratória/efeitos da radiação , Sensibilidade e Especificidade , Especificidade da Espécie
11.
Int J Radiat Biol ; 78(7): 567-76, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12079535

RESUMO

PURPOSE: Local irradiation with a dose of around 0.5 Gy is an effective treatment of acute necrotizing inflammations. The hypothesis that low doses of X-rays modulate the oxidative burst in activated macrophages, which plays a major role in the acute inflammatory process, was tested. MATERIALS AND METHODS: Murine RAW 264.7 macrophages were stimulated with LPS/gammaIFN, PMA or zymosan and oxidative burst was measured using either DCFH-DA or by reduction of cytochrome-C. Radiation doses of 0.3-10 Gy were given shortly before or after stimulation. RESULTS: Low X-ray doses of <1 Gy significantly reduced the oxidative burst in activated macrophages, whereas higher doses had little effect on oxidative burst. CONCLUSIONS: The modulation of oxidative burst by low radiation doses may contribute to the therapeutic effectiveness of low-dose radiotherapy of acute necrotizing inflammations.


Assuntos
Macrófagos/efeitos da radiação , Explosão Respiratória/efeitos da radiação , Animais , Linhagem Celular , Relação Dose-Resposta à Radiação , Interferon gama/farmacologia , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Camundongos , NADPH Oxidases/metabolismo , Óxido Nítrico/biossíntese , Superóxidos/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Raios X
12.
Oncogene ; 20(48): 7085-95, 2001 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-11704832

RESUMO

Haemopoietic tissues exposed to ionizing radiation are shown to exhibit increased macrophage activation, defined by ultrastructural characteristics and increased lysosomal and nitric oxide synthase enzyme activities. Macrophage activation post-irradiation was also associated with enhanced respiratory burst activities and an unexpected neutrophil infiltration. Examination of p53-null mice demonstrated that macrophage activation and neutrophil infiltration were not direct effects of irradiation, but were a consequence of the recognition and clearance of radiation-induced apoptotic cells. Increased phagocytic cell activity was maintained after apoptotic bodies had been removed. These findings demonstrate that, contrary to expectation, recognition and clearance of apoptotic cells after exposure to radiation produces both a persistent macrophage activation and an inflammatory-type response. We also demonstrate a complexity of macrophage activation following radiation that is genotype dependent, indicating that the in vivo macrophage responses to radiation damage are genetically modified processes. These short-term responses of macrophages to radiation-induced apoptosis and their genetic modification are likely to be important determinants of the longer-term consequences of radiation exposure. Furthermore, in addition to any effects attributable to immediate radiation-induced damage, our findings provide a mechanism for the production of damage via a 'bystander' effect which may contribute to radiation-induced genomic instability and leukaemogenesis.


Assuntos
Apoptose/efeitos da radiação , Efeito Espectador/fisiologia , Quimiotaxia de Leucócito/efeitos da radiação , Raios gama/efeitos adversos , Inflamação/etiologia , Ativação de Macrófagos/efeitos da radiação , Lesões Experimentais por Radiação/etiologia , Tirosina/análogos & derivados , Irradiação Corporal Total/efeitos adversos , Animais , Medula Óssea/patologia , Relação Dose-Resposta à Radiação , Indução Enzimática/efeitos da radiação , Genes p53 , Predisposição Genética para Doença , Genótipo , Inflamação/fisiopatologia , Lisossomos/enzimologia , Lisossomos/ultraestrutura , Ativação de Macrófagos/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Endogâmicos DBA , Camundongos Knockout , Neutrófilos/fisiologia , Óxido Nítrico Sintase/biossíntese , Óxido Nítrico Sintase Tipo II , Lesões Experimentais por Radiação/fisiopatologia , Tolerância a Radiação/genética , Explosão Respiratória/efeitos da radiação , Especificidade da Espécie , Baço/patologia , Proteína Supressora de Tumor p53/deficiência , Proteína Supressora de Tumor p53/fisiologia , Tirosina/metabolismo , beta-Galactosidase/biossíntese
13.
Biofizika ; 46(2): 291-7, 2001.
Artigo em Russo | MEDLINE | ID: mdl-11357344

RESUMO

The role of some components of the phospholipid metabolism in the activation of neutrophil respiratory burst and its inhibition by electromagnetic radiation (EMR) of extremely high frequencies (EHF) was studied. It was shown that EHF EMR has effect on cells with a high sensitivity to the inhibitor of phospholipase A2 4-bromophenacyl bromide. However, againsts the background of the inhibitor, the effect of EHF EMR was not observed on cells with either high or low sensitivity to the inhibitor. EHF EMR was also inefficient with cells pretreated with proadifen, an inhibitor of epoxygenase (cytochrome P-450). The results obtained suggest that the effect of EHF EMR manifests itself in cells with a high activity of phospholipase A2 and is realized with the participation of epoxygenase metabolites of arachidonic acid.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Micro-Ondas , Neutrófilos/metabolismo , Oxigenases/metabolismo , Fosfolipases A/metabolismo , Explosão Respiratória/efeitos da radiação , Acetofenonas/farmacologia , Animais , Calcimicina/farmacologia , Citocromo P-450 CYP2J2 , Inibidores das Enzimas do Citocromo P-450 , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Técnicas In Vitro , Ionóforos/farmacologia , Masculino , Camundongos , Neutrófilos/enzimologia , Oxigenases/antagonistas & inibidores , Cavidade Peritoneal/citologia , Fosfolipases A/antagonistas & inibidores , Fosfolipases A2 , Proadifeno/farmacologia , Acetato de Tetradecanoilforbol/farmacologia
15.
Toxicol Lett ; 112-113: 303-10, 2000 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10720745

RESUMO

Ultraviolet B radiation penetrates into water and can affect fish health and the immune system, as is the case with mammals. Teleost fish, the roach, were exposed to UVB irradiation in aquariums and a panel of immune parameters was determined. In addition to altered blood picture and respiratory burst by blood leukocytes, changes were noted also in major lymphatic organs. Respiratory burst and natural cytotoxicity activity of head kidney granulocytes and mitogen-activated proliferation of splenic lymphocytes were suppressed. Although mostly transitory, some parameters remained suppressed for the following 2 weeks. Ultraviolet A radiation had only minor effects. The stress induced by UVB may be involved in the modulation of immune parameters.


Assuntos
Peixes , Sistema Imunitário/efeitos da radiação , Raios Ultravioleta/efeitos adversos , Animais , Peixes/imunologia , Granulócitos/efeitos da radiação , Cabeça/efeitos da radiação , Humanos , Rim/efeitos da radiação , Linfócitos/efeitos da radiação , Explosão Respiratória/efeitos da radiação
16.
Photochem Photobiol ; 71(1): 65-70, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10649891

RESUMO

The effects of a single dose of ultraviolet B (UVB) radiation (0.4 J/cm2) on immunological functions by blood leukocytes and on hematological parameters was studied in roach (Rutilus rutilus), a teleostean fish. The respiratory burst of phorbol 12-myristate 13-acetate stimulated whole blood phagocytes increased significantly after UVB irradiation but spontaneous cytotoxicity of blood leukocytes toward 51chromium-labeled K562 target cells was not markedly altered. Differential cell counting revealed that UVB exposure significantly increased the proportion of granulocytes and significantly decreased the proportion of lymphocytes in the peripheral blood, whereas hematocrit and the total number of white and red blood cells were unchanged. Plasma cortisol concentration increased in UVB-exposed fish. Severe handling stress caused similar, although not as potent, effects on the measured parameters of fish blood as UVB irradiation. These observations suggest that in fish UVB brings about a stress response, which may account for the observed alterations in the immune parameters and leukocyte composition of blood. Exposure of fish to strong visible light induced no alterations in immunological or hematological parameters, making it unlikely that ultraviolet radiation mediates its effects through visual perception.


Assuntos
Sistema Imunitário/efeitos da radiação , Animais , Cyprinidae/sangue , Cyprinidae/imunologia , Citotoxicidade Imunológica/efeitos dos fármacos , Citotoxicidade Imunológica/efeitos da radiação , Humanos , Sistema Imunitário/efeitos dos fármacos , Células K562 , Explosão Respiratória/efeitos dos fármacos , Explosão Respiratória/efeitos da radiação , Acetato de Tetradecanoilforbol/farmacologia , Raios Ultravioleta
17.
FEBS Lett ; 446(1): 15-7, 1999 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-10100605

RESUMO

It is known that low intensity magnetic fields increase superoxide anion production during the respiratory burst of rat peritoneal neutrophils in vitro. We investigated whether the high intensity magnetic fields (1.5 T) during magnetic resonance imaging can influence the human neutrophil function under in vivo conditions. Blood samples were obtained from 12 patients immediately before and after magnetic resonance imaging (mean time 27.6(+/-11.4 min)). The induced respiratory burst was investigated by the intracellular oxidative transformation of dihydrorhodamine 123 to the fluorescent dye rhodamine 123 via flow cytometry. The respiratory burst was induced either with phorbol 12-myristate 13-acetate, Escherichia coli, N-formyl-methionyl-leucylphenylalanine or priming with tumor necrosis factor followed by FMLP stimulation. There was no significant difference between the respiratory burst before and after magnetic resonance imaging, irrespective of the stimulating agent. Short time exposure to a high intensity magnetic field during magnetic resonance imaging seems not to influence the production of radical species in living neutrophils.


Assuntos
Imageamento por Ressonância Magnética/efeitos adversos , Neutrófilos/efeitos da radiação , Explosão Respiratória/efeitos da radiação , Adulto , Animais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Ratos
18.
Photochem Photobiol ; 67(4): 433-7, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9559587

RESUMO

Roach (Rutilus rutilus) were irradiated with a single dose of ultraviolet B (UVB) radiation (0.4 J/cm2) in order to study the effects of UVB on the nonspecific immune defense mechanisms of fish. Neutrophils and macrophages were isolated from the head kidney of fish on days 1-14 postirradiation. Both random and directed migration of neutrophils, studied by migration under agarose assay, were suppressed on day 1 after UVB irradiation. The respiratory burst of phorbol 12-myristate 13-acetate-stimulated neutrophils and macrophages was also suppressed at days 1 and 2 after UVB irradiation. The suppression of migration and respiratory burst were restored or the responses were even enhanced later, but on the other hand spontaneous cytotoxicity of neutrophils toward 51chromium-labeled K562 target cells stayed suppressed throughout the 14 day follow-up. This study indicates that UVB radiation has the potential to suppress the functioning of phagocytes and to compromise the immune system of fish.


Assuntos
Quimiotaxia de Leucócito/efeitos da radiação , Peixes/imunologia , Neutrófilos/efeitos da radiação , Fagócitos/efeitos da radiação , Raios Ultravioleta , Animais , Carpas/imunologia , Tecido Linfoide/efeitos da radiação , Macrófagos/imunologia , Macrófagos/efeitos da radiação , Neutrófilos/fisiologia , Fagócitos/efeitos dos fármacos , Fagócitos/imunologia , Explosão Respiratória/efeitos dos fármacos , Explosão Respiratória/efeitos da radiação , Acetato de Tetradecanoilforbol/farmacologia
19.
Biofizika ; 42(5): 1125-34, 1997.
Artigo em Russo | MEDLINE | ID: mdl-9410041

RESUMO

The influence of low-intensity modulated electromagnetic radiation of extremely high frequencies (EHF EMR) on synergistic reaction of calcium ionophore A23187 and phorbol ester PMA in activation of the respiratory burst of the peritoneal neutrophils of mice line NMRI was investigated. The production of reactive oxygen species by the neutrophils was estimated by luminol-dependent chemiluminescence technique. The cells were irradiated in the far field zone of the channel radiator for 20 min in the presence of A23187 and then were activated by PMA after switching off the irradiation. It was shown, that continuous EHF EMR (50 microW/cm2) inhibited quasi-resonantly the synergistic reaction. The maximum effect was about 25% at carrier frequency of 41.95 GHz. Modulated radiation with carrier frequency of 41.95 GHz and modulation frequency of 1 Hz activated the synergistic reaction, but at modulation frequencies of 0.1, 16 and 50 Hz inhibited one. At fixed modulation frequency of 1 Hz the nonlinear dependence of the effect on the carrier frequency was found. The synergistic reaction was activated in the frequency range of 41.95-42.05 GHz and was inhibited at the frequencies of 41.8-41.9 GHz. The effect was observed only at raised intracellular free calcium concentration and at calcium fluxes through plasma membrane. The obtained results prove the possibility of control over cell functioning by low-intensity modulated EHF EMR, presumably, manipulating by connected systems of enzyme reactions.


Assuntos
Micro-Ondas , Neutrófilos/efeitos da radiação , Explosão Respiratória/efeitos da radiação , Animais , Calcimicina/farmacologia , Calcimicina/efeitos da radiação , Cálcio/metabolismo , Sinergismo Farmacológico , Ionóforos/farmacologia , Ionóforos/efeitos da radiação , Camundongos , Neutrófilos/metabolismo , Cavidade Peritoneal/citologia , Acetato de Tetradecanoilforbol/farmacologia , Acetato de Tetradecanoilforbol/efeitos da radiação
20.
Clin Lab Haematol ; 19(1): 39-47, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9146946

RESUMO

Treatment of human polymorphonuclear leucocytes (PMNL) separated by density sedimentation (DS) from normal donors (PMNL-NL-DS) with interferon-gamma (IFN-gamma) + granulocyte colony-stimulating factor (G-CSF) lessens the damage caused by isolation and irradiation. We have studied granulocyte-macrophage colony-stimulating factor (GM-CSF) in this system, as well as the behaviour of PMNL collected by continuous flow leucapheresis (CFL) from donors treated with G-CSF (PMNL-GCSF-CFL). After isolation, PMNLs were treated with IFN-gamma + G-CSF, GM-CSF or IFN-gamma + G-CSF + GM-CSF, irradiated with 0 or 30 Gy and studied after 0 and 20 h in cell culture. All regimens reduced apoptosis of PMNL-NL-DS. Killing of Candida albicans by 20-h-old PMNL-NL-DS was best preserved by IFN-gamma + G-CSF treatment. A similar pattern of results was obtained for assays of PMNL-NL-DS chemotaxis and superoxide production. There was a consistent trend toward reduced function after irradiation in all assays. PMNL-GCSF-CFL less often demonstrated the morphological features of apoptosis, and this was further reduced by cytokine regimens containing IFN-gamma + G-CSF. In assays of C. albicans killing and chemotaxis, 20-h-old untreated PMNL-GCSF-CFL performed as well as freshly isolated PMNL-GCSF-CFL. PMNL-GCSF-CFL showed decay in CD11b (CR3), CD16 (Fc gamma III) and CD64 (Fc gamma R1) expression after 20 h in cell culture, but treatment with IFN-gamma + G-CSF preserved expression. There was a trend toward reduced function after radiation. Comparison of PMNL-GCSF separated by CFL and DS demonstrated that CFL itself is a strong inducer of the morphological features of apoptosis. This study shows that while separation by CFL, and irradiation are damaging to PMNLs, damage may be reduced by use of cytokines.


Assuntos
Citocinas/farmacologia , Leucaférese/efeitos adversos , Transfusão de Leucócitos , Neutrófilos/efeitos dos fármacos , Neutrófilos/efeitos da radiação , Antígenos de Superfície/biossíntese , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Centrifugação com Gradiente de Concentração , Quimiotaxia de Leucócito/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos/farmacologia , Humanos , Interferon gama/farmacologia , Neutrófilos/fisiologia , Explosão Respiratória/efeitos dos fármacos , Explosão Respiratória/efeitos da radiação
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