Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Polymers (Basel) ; 13(17)2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34502896

RESUMO

Plasma-induced free-radical polymerizations rely on the formation of radical species to initiate polymerization, leading to some extent of monomer fragmentation. In this work, the plasma-induced polymerization of an allyl ether-substituted six-membered cyclic carbonate (A6CC) is demonstrated and emphasizes the retention of the cyclic carbonate moieties. Taking advantage of the low polymerization tendency of allyl monomers, the characterization of the oligomeric species is studied to obtain insights into the effect of plasma exposure on inducing free-radical polymerization. In less than 5 min of plasma exposure, a monomer conversion close to 90% is obtained. The molecular analysis of the oligomers by gel permeation chromatography coupled with high-resolution mass spectrometry (GPC-HRMS) further confirms the high preservation of the cyclic structure and, based on the detected end groups, points to hydrogen abstraction as the main contributor to the initiation and termination of polymer chain growth. These results demonstrate that the elaboration of surfaces functionalized with cyclic carbonates could be readily elaborated by atmospheric-pressure plasmas, for instance, by copolymerization.

2.
Patient Prefer Adherence ; 14: 227-234, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32103907

RESUMO

PURPOSE: Scientific research and public opinion polls indicate that the majority of patients and their families believe that members of the patients' family should be offered the opportunity to be present during CPR, at the moment of their loved one's death, and throughout all aspects of emergency care. The study was designed to analyse the experiences and opinions of patients and family members towards Family Presence During Resuscitation (FPDR) in hospitals in Poland. PATIENTS AND METHODS: We conducted a survey related to FPDR among patients and their families during 5 months in 2017. That was preceded by a pilot study. We asked the patients and the people accompanying them to complete the questionnaire during admission to the hospital; 1000 questionnaires (500 patient responses and 500 family responses) were included in the analysis. RESULTS: Patients and their relatives more often wanted to be present during resuscitation of a loved one than they agreed to the presence of the family during their resuscitation. The vast majority of patients did not know the patient's rights regarding FPDR. 24.2% of patients and 29.2% of their relatives participated in the discussions on FPDR. The interest in FPDR indicated 29.0% of patients and 27.6% of family members. CONCLUSION: In our survey study, both patients and their family members had a negative attitude towards FPDR. Respondents (both patients and family members) had a low level of awareness that their potential to be present during CPR was included in the patient's rights.

4.
Glob Adv Health Med ; 8: 2164956119897566, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32002311

RESUMO

BACKGROUND: The emphasis on Evidence-Based Practice (EBP) is taking on new importance as the profession of nursing strives to meet the challenge of defining the direction of health care, promoting optimal outcomes, and ensuring patient safety. Therefore, Evidence-Based Practice has never been more important to nursing than in the current health-care environment. OBJECTIVE: The study was designed to assess the knowledge, behaviors, and attitudes of nurses as compared with Evidence-Based Practice in relation to the Guidelines of the European Resuscitation Council. METHODS: The study covered involved a total of 236 nurses who participated in a cardiopulmonary resuscitation course over a period of 12 months. The nurses who qualified for the study followed a complete study registration procedure. RESULTS: The current findings show that the lowest score was achieved in the domain of attitude toward selected Evidence-Based Practice aspects in professional work. Detailed domain questions concerned nurses' Evidence-Based Practice and its limitations related to procedures, the lack of equipment and personnel issues, as well as the lack of scientific evidence. Furthermore, nurses saw clinical experience as being more valuable than research findings for practical decision-making than research findings, and, according to the respondents, they presented opinions that the best way to assess the effectiveness of an action was through clinical experience. In addition, the nurses gave low scores and tended to underestimate the critical literature review aspect within the domain, along with its significance for the general professional practice, believing that search for scientific evidence alone does not apply into their professional work. CONCLUSIONS: The validated Polish version of the Evidence-Based Practice profile questionnaire is a reliable instrument. The study demonstrates that nurses are facing a multitude of limitations due to procedures, the lack of equipment, and personnel issues. Currently perceived as very poor, the ability to make critical assessments and synthesize evidence should be improved. According to the nurses, clinical experience cannot be the only and the best way to assess the effectiveness of a given measure.

6.
Ann Rheum Dis ; 72(9): 1510-6, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23041938

RESUMO

OBJECTIVES: To identify non-major histocompatibility complex susceptible genes that might contribute to Behçet's disease (BD). METHODS: We performed a genome-wide association study using DNA samples from a Korean population consisting of 379 BD patients and 800 controls. A replication study was performed in a Japanese population (363 BD patients and 272 controls). To evaluate the functional implication of the target single nucleotide polymorphisms (SNP), gene expression levels in peripheral T cells, allele-specific modulation of promoter activity and biological effect of mRNA knockdown were investigated. RESULTS: We found a novel association of BD to the GIMAP locus, mapped to chromosome 7q36.1 (rs1608157, p=6.01×10(-8) in a minor allele dominant model; rs11769828, allele based p=1.60×10(-6)). A fine mapping study identified an association with four additional SNP: rs1522596 (OR=1.45, p=7.70×10(-6)) in GIMAP4; rs10266069 (OR=1.32, p=2.67×10(-4)) and rs10256482 (OR=1.27, p=5.27×10(-4)) in GIMAP2; and rs2286900 (OR=1.61, p=3.53×10(-5)) in GIMAP1 areas. Replication study using DNA samples from the Japanese population validated the significant association between BD and the GIMAP locus. The GIMAP4 promoter construct plasmid with the minor allele of rs1608157 displayed significantly lower activity than one with the major allele. Moreover, CD4 T cells from BD patients showed a lower level of GIMAP4 mRNA, and GIMAP4 knockdown was protective against Fas-mediated apoptosis. CONCLUSIONS: These results suggest that a GIMAP cluster is a novel susceptibility locus for BD, which is involved in T-cell survival, and T-cell aberration can contribute to the development of BD.


Assuntos
Síndrome de Behçet/genética , Proteínas de Ligação ao GTP/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/métodos , Polimorfismo de Nucleotídeo Único , Adulto , Povo Asiático , Síndrome de Behçet/diagnóstico , Síndrome de Behçet/imunologia , Sobrevivência Celular , Mapeamento Cromossômico , Cromossomos Humanos Par 7 , Feminino , Técnicas de Silenciamento de Genes , Loci Gênicos , Humanos , Japão , Masculino , Interferência de RNA , RNA Mensageiro/metabolismo , Linfócitos T/imunologia , Linfócitos T/patologia
7.
Mitochondrion ; 7(1-2): 119-24, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17300998

RESUMO

Apoptosis is induced not only during morphogenesis and embryogenesis but also under various pathological conditions, especially related to oxidative stress. Apoptotic cells are phagocytized by neighboring cells while necrotic cells cause local and general reactions sometimes lethal to our bodies. Data have been accumulated to demonstrate that the switch of the cell death mode from apoptosis to necrosis does occur. However, detailed mechanisms involved in the switch mechanism remain unsolved although decreases in the intracellular level of ATP and a burst in the cellular level of reactive oxygen species (ROS) have been proposed. Recently, we have shown that the population of apoptotic cells reaches maximum in human osteosarcoma 143B cells treated for 6h with menadione (MEN) while necrotic cells become predominant at 9h of the treatment. In the present study we have attempted to clarify the role of cellular ATP in the switch mechanism using rho(0) cells derived from human osteosarcoma rho+ cells. Results are summarized as follows: (1) Apoptotic and necrotic changes in rho(0) cells are much faster than rho+ cells after the treatment with MEN. (2) Cellular level of ATP in rho(0) cells remains essentially in the same level before and after the MEN-treatment while intracellular levels of superoxide continuously increase after the MEN-treatment. (3) rho+ cells treated with MEN in the presence of antimycin A plus oligomycin show similar changes to those of MEN-treated rho(0) cells. (4) MEN-induced increases in the cellular level of superoxide are distinctly suppressed by inhibitors of NADPH oxidase. These results suggest that the intracellular level of superoxide may be a key factor directly related to the switch mechanism from apoptosis to necrosis, and that decreases in cellular level of ATP accelerate both apoptotic and necrotic changes of the cells.


Assuntos
Apoptose/fisiologia , Necrose/fisiopatologia , Estresse Oxidativo/fisiologia , Antimicina A/farmacologia , Humanos , Microscopia Eletrônica , Oligomicinas/farmacologia , Células Tumorais Cultivadas , Vitamina K 3/farmacologia
8.
J Electron Microsc (Tokyo) ; 54(2): 127-38, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15994205

RESUMO

Detailed mechanisms of the switch of the cell death mode from apoptosis to necrosis remain to be solved, although the intracellular level of ATP and that of free radicals have been postulated to be the major factors involved in the mechanisms. In the present study menadione (MEN)-induced cell injury processes were studied using rho0 cells derived from human osteosarcoma 143B cells and parental rho+ cells co-treated with inhibitors of electron transfer chain of mitochondria or oligomycin, an inhibitor of ATP synthesis. Treatment of rho+ cells with 100 microM MEN induced apoptosis, which reached the maximum at 6 h, and was followed by an abrupt decrease thereafter, while necrotic cells (NC) increased continuously when they were judged by Annexin V and PI double staining. On the other hand, MEN induced apoptotic and necrotic changes much faster in rho0 cells compared to rho+ cells. The frequency to find apoptotic cells (AP) in the former cells was distinctly smaller than that to find NC judged by Annexin V and PI double staining. Electron microscopically, a major population of rho0 cells treated with MEN for 6 h consisted of intermediate cells, and a small number of AP co-existed. At 9 h of the treatment intermediate cells were exclusively seen, and AP were hardly detected. When parental rho+ cells were treated with MEN in the presence of oligomycin or oligomycin plus antimycin A both apoptotic and necrotic changes of the cells were distinctly accelerated. The intracellular level of superoxide in rho0 cells continuously increased after the MEN treatment, whereas that of ATP remained distinctly low before and after the MEN treatment compared to that in rho+ cells. These data suggest that the intracellular level of superoxide may be a key factor controlling the switch from apoptosis to necrosis.


Assuntos
Apoptose/fisiologia , Mitocôndrias/fisiologia , Necrose/metabolismo , Trifosfato de Adenosina/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Transporte de Elétrons/efeitos dos fármacos , Citometria de Fluxo , Humanos , Potenciais da Membrana , Microscopia Eletrônica de Transmissão , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Oligomicinas/farmacologia , Fosforilação Oxidativa , Inibidores da Síntese de Proteínas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Vitamina K 3/farmacologia
9.
J Electron Microsc (Tokyo) ; 53(6): 635-47, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15582977

RESUMO

Effects of jasplakinolide (JSP), a stabilizer of F-actin, and latrunculin A (LTA), a destabilizer of F-actin, on a series of events occurring in the execution phase of staurosporine (STS)-induced apoptotic processes were studied using human osteosarcoma 143B cells. Time-dependent apparent increases of the population of cells with collapsed membrane potential of mitochondria (Delta Psi(m)) caused by STS treatment were not due to actual decreases in the Delta Psi(m) per cell, but due to the fragmentation of cells resulting in decreases in the number of active mitochondria per cell. Decreases in the Delta Psi(m) in fragmented cells occurred late in the execution phase. Both JSP and LAT failed to prevent STS-induced release of cytochrome c from mitochondria followed by the activation of caspases 3 and 9, the cleavage of poly (ADP-ribose) polymerase (PARP) and apoptotic nuclear fragmentation. However, both drugs prevented STS-induced apoptotic cell fragmentation and decreases in the Delta Psi(m). These results indicate that physicochemical states of actin filaments play a certain role in the execution phase of STS-induced apoptotic processes.


Assuntos
Citoesqueleto de Actina/efeitos dos fármacos , Apoptose/fisiologia , Inibidores Enzimáticos/farmacologia , Estaurosporina/farmacologia , Citoesqueleto de Actina/metabolismo , Antineoplásicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Caspases/efeitos dos fármacos , Caspases/metabolismo , Linhagem Celular Tumoral , Depsipeptídeos/farmacologia , Humanos , Immunoblotting , Potenciais da Membrana/efeitos dos fármacos , Microscopia Confocal , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Tiazóis/farmacologia , Tiazolidinas
10.
J Electron Microsc (Tokyo) ; 53(6): 659-70, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15582979

RESUMO

Treatment of 143B cells with microtubule-active drugs (MADs) including taxol, nocodazole and colchicine induced distinct structural changes, such as rounding of the cells with perinuclear clustering of mitochondria, when the cells were treated for up to 10 h. When the incubation time with MADs was longer than 10 h, multinuclear cells appeared, and their population increased with time. In this study perinuclear clustering of mitochondria i.e. mitochondria encircling the aggregated chromatin of the nucleus that had lost the nuclear membrane was detected. This observation was distinct from that reported in the literature. Mitochondria were aligned in a few lines; the occurrence of mitochondria in even a single line is an extreme case, resulting in one plane of section for electron microscopy. Three-dimensional reconstructions of confocal microscopic images of mitochondria revealed that they were assembled as a spherical structure. The majority of the cells with perinuclear clustering of mitochondria remained intact for up to 24 h. Mitochondria were observed to be clustered around the nucleus in the orthodox configuration or in some cases they were moderately condensed, as observed electron microscopically. Annexin V and PI double staining of cells showed that more than 90% of cells were viable. In the case of treatment with taxol, membrane potential of mitochondria per cell was well maintained although it was moderately lowered in the case of treatment with nocodazole. Taking into consideration the previous data reported from our laboratory, the present results may assist in elucidation of the behaviour of mitochondria during the dividing processes of mammalian cells, which is yet to be clarified.


Assuntos
Cromatina/ultraestrutura , Microtúbulos/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Núcleo Celular/ultraestrutura , Colchicina/farmacologia , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Microtúbulos/fisiologia , Nocodazol/farmacologia , Paclitaxel/farmacologia
11.
Acta Biochim Pol ; 51(4): 1015-22, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15625573

RESUMO

The effects of inhibitors of plasma membrane NADPH oxidase on menadione-induced cell injury processes were studied using human osteosarcoma 143B cells. The intracellular level of superoxide in the cells treated with menadione for 6 h reached a maximum followed by an abrupt decrease. The population of apoptotic cells detected by Annexin V and propidium iodide double staining also reached its maximum at 6 h of menadione-treatment while that of necrotic cells increased continuously reaching 90% of the total population at 9 h of the treatment. Pretreatment of the cells with inhibitors of NADPH oxidase, including diphenyliodonium chloride, apocynin, N-vanillylnonanamide and staurosporine was effective in lowering the menadione-induced elevations of superoxide, and also in the suppression of the switch of the cell death mode from apoptosis to necrosis in menadione-treated cells except for the case of staurosporine. These results strongly suggest that superoxide generated by NADPH oxidase, besides that generated by the mitochondria, may contribute to the remarkable increase in the intracellular level of superoxide in the cells treated with menadione for 6 h resulting in the switch from apoptosis to necrosis, although a direct evidence of the presence of active and inactive forms of NADPH oxidase in control and menadione-treated 143B cells is lacking at present.


Assuntos
Apoptose , Membrana Celular/enzimologia , NADH NADPH Oxirredutases/fisiologia , Necrose , Vitamina K 3/toxicidade , Linhagem Celular Tumoral , Humanos , NADH NADPH Oxirredutases/antagonistas & inibidores , NADPH Oxidases , Superóxidos/metabolismo
12.
Acta Biochim Pol ; 51(4): 1023-38, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15625574

RESUMO

Characterization of free radical-induced cell injury processes of placenta cells is of vital importance for clinical medicine for the maintenance of intrauterine fetal life. The present study has analyzed cell injury processes in cells of the choriocarcinoma cell line JAR treated with menadione, an anticancer drug, and H(2)O(2) in comparison to osteosarcoma 143B cells using electron microscopic and flow cytometric techniques. Flow cytometry on JAR cells exposed to 100 muM menadione and double-stained with Annexin V and propidium iodide (PI) detected apoptotic cells reaching the maximum after 4 h of incubation with a rapid decrease thereafter. Viable cells became decreased to 46% of the control after 2 h of incubation, reaching 5% after 4 h. Cells stainable with both Annexin V and PI began to increase distinctly after 2 h of incubation, reaching 55% after 4 h. Electron microscopy showed that cells stainable with both dyes specified above had condensed nuclei and swollen cytoplasm, suggesting that they were undergoing a switch of the cell death mode from apoptosis to necrosis. On the other hand, 90% of 143B cells remained intact after 4 h of menadione treatment although the intracellular levels of superoxide were always higher than those of JAR cells treated with the drug. In contrast, JAR cells were more resistant than 143B cells to H(2)O(2)-induced cytotoxicity. These results may suggest that cytotoxicity of menadione cannot be explained simply by oxygen free radicals generated from the drug. The resistance of JAR cells to oxygen free radical-induced cytotoxicity may be advantageous for intrauterine fetal life.


Assuntos
Apoptose , Estresse Oxidativo/fisiologia , Trofoblastos/metabolismo , Neoplasias Ósseas , Linhagem Celular Tumoral , Sobrevivência Celular , Coriocarcinoma , Humanos , Peróxido de Hidrogênio/toxicidade , Osteossarcoma , Superóxidos/metabolismo , Trofoblastos/efeitos dos fármacos , Trofoblastos/ultraestrutura , Vitamina K 3/toxicidade
13.
Microsc Res Tech ; 64(3): 255-8, 2004 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-15452893

RESUMO

Time-dependent changes in the cell death mode from apoptosis to necrosis were studied in cultured 143B cells treated with menadione, an anti-cancerous drug, excluding a possible involvement of "secondary necrosis." The population of apoptotic cells judged by FITC-Annexin V and propidium iodide (PI) double staining reached its maximum at 6 hours after 100 microM menadione treatment followed by an abrupt decrease thereafter, while that of necrotic cells continuously increased reaching 90% at 24 hours. Electron microscopically, cells attached to the culture dish at 6 hours after the treatment consisted of two different types of cells: cells with typical apoptotic features occupying the major population and those with condensed nuclei and swollen cytoplasm. Cells attached to the culture dish at 8 hours after the treatment consisted exclusively of those with condensed nuclei and swollen cytoplasm. Mitochondria in these cells showed various structural changes: those swollen to various degrees with deposition of flocculent densities, or those with highly condensed matrix. Distinct decreases both in intracellular levels of ATP and caspase-3-like activities and remarkable elevations of intracellular levels of superoxide, which were partly suppressed by NAD(P)H oxidase inhibitors, occurred at 6 hours after the treatment. These results may suggest that distinct increases of the intracellular level of superoxide derived from plasma membrane NAD(P)H oxidase besides that from mitochondria have triggered the transition of cell death mode from apoptosis to necrosis. Transition of highly condensed mitochondria to extremely swollen ones may reflect necrotic processes in menadione-treated cells. The present study strongly suggests that time-dependent study is essential using the electron microscopic technique to analyze detailed processes in the changes of the cell death mode.


Assuntos
Morte Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Mitocôndrias/metabolismo , Osteossarcoma/metabolismo , Vitamina K 3/farmacologia , Acetofenonas/farmacologia , Trifosfato de Adenosina/metabolismo , Apoptose/efeitos dos fármacos , Caspase 3 , Caspases/metabolismo , Núcleo Celular/efeitos dos fármacos , Clonagem Molecular , Inibidores Enzimáticos/farmacologia , Citometria de Fluxo , Humanos , Microscopia Eletrônica de Transmissão , Mitocôndrias/efeitos dos fármacos , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/metabolismo , Necrose , Osteossarcoma/tratamento farmacológico , Superóxidos/metabolismo , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...