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1.
Med Oral Patol Oral Cir Bucal ; 26(1): e64-e70, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33037803

RESUMO

BACKGROUND: The efficacy of preemptive analgesia in managing postoperative pain remains controversial. The aim of this study was to compare the efficacy of intravenous (IV) acetaminophen administered before or immediately after the surgical extraction of an impacted mandibular third molar. MATERIAL AND METHODS: This prospective randomized clinical trial included 120 patients. The patients were assigned to one of three groups: the preoperative-treatment group (pre-group), which received 1000 mg of IV acetaminophen 20 min before surgery; the postoperative-treatment group (post-group), which received 1000 mg of IV acetaminophen after surgery; the no-treatment group (control-group), which did not receive any analgesic. Rescue analgesic (60 mg loxoprofen) was issued to each patient, with instructions on self-administration if needed. For the rescue medication usage, the time of first loxoprofen usage and the total amount of loxoprofen consumption were obtained for a 17-hour period after surgery. We measured pain using the visual analogue scale at 1 hour and at 2, 3, 4, 5, and 15 hours after surgery. RESULTS: There was no significant difference in pain level among the three groups at any time interval. However, the pre-group demonstrated significantly lower rescue analgesic consumption and longer time until initial administration. CONCLUSIONS: Administration of IV acetaminophen before third molar surgery provides more effective pain control than postoperative administration and no treatment.


Assuntos
Analgesia , Analgésicos não Narcóticos , Acetaminofen/uso terapêutico , Analgésicos não Narcóticos/uso terapêutico , Analgésicos Opioides , Método Duplo-Cego , Humanos , Dente Serotino/cirurgia , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controle , Estudos Prospectivos , Método Simples-Cego , Extração Dentária
2.
Phys Chem Chem Phys ; 19(7): 5310-5317, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28155939

RESUMO

A nerve conduction model is constructed by using some liquid-membrane cells that mimic the function of the K+ and Na+ channels. By imitating two types of Na+ channels (ligand-gated Na+ channels and voltage-gated Na+ channels), a new mechanism for the directional propagation of the action potential along the axon toward the axon terminal is proposed. When the nerve cell is excited by an external (outer) stimulus, it can be presumed that the ligand-gated channels work as power sources at the synapse to propagate the change in the membrane potential, and then the voltage-gated channels locally assist the propagation at each site of the axon (nodes of Ranvier).


Assuntos
Potenciais de Ação/fisiologia , Modelos Biológicos , Condução Nervosa/fisiologia , Canais de Potássio/metabolismo , Canais de Sódio/metabolismo
3.
Transfus Med ; 26(5): 365-372, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27350440

RESUMO

BACKGROUND AND OBJECTIVES: The effect of leukoreduction and storage periods on the accumulation of bioactive lysophospholipids and substances in human autologous blood (AB units) has not been fully investigated. MATERIALS AND METHODS: The accumulation of bioactive lysophospholipids such as sphingosine 1-phosphate (S1P) and lysophosphatidylserine (LysoPS) in AB units during the storage was investigated. The time-dependent changes and the effect of the filtration in pre-storage leuckoreduction (LR) and unmodified samples derived from 46 AB units were analysed. Additionally, the changes of lysophospholipids and platelet releasate, namely ß-thromboglobulin (ß-TG), induced by exposure of whole blood (WB) or platelet-rich plasma (PRP) to the filter material were analysed. RESULTS: LysoPS, but not S1P levels, time-dependently and significantly increased in both unmodified and LR samples. LysoPS significantly decreased in LR compared with unmodified samples, whereas S1P increased in LR compared with unmodified samples. In addition, exposure of WB and/or PRP to the filter material in vitro resulted in increased levels of S1P, LysoPS and ß-TG. CONCLUSIONS: LR effectively reduced the accumulation of LysoPS in AB units. On the other hand, it increased concentrations of S1P due to platelet activation by exposure to the filter material. These suggest that increases of S1P levels in LR and LysoPS in the unmodified samples were mainly caused by the leukocytes and/or platelets and that LR was effective in inhibiting the accumulation of LysoPS.


Assuntos
Preservação de Sangue , Transfusão de Sangue Autóloga , Procedimentos de Redução de Leucócitos , Lisofosfolipídeos/sangue , Esfingosina/análogos & derivados , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esfingosina/sangue
4.
QJM ; 117(3): 187-194, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-37878823

RESUMO

OBJECTIVE: To comprehensively evaluate diagnostic algorithms for myocardial infarction using a high-sensitivity cardiac troponin I (hs-cTnI) assay. PATIENTS AND METHODS: We prospectively enrolled patients with suspected myocardial infarction without ST-segment elevation from nine emergency departments in Japan. The diagnostic algorithms evaluated: (i) based on hs-cTnI alone, such as the European Society of Cardiology (ESC) 0/1-h or 0/2-h and High-STEACS pathways; or (ii) used medical history and physical findings, such as the ADAPT, EDACS, HEART, and GRACE pathways. We evaluated the negative predictive value (NPV), sensitivity as safety measures, and proportion of patients classified as low or high-risk as an efficiency measure for a primary outcome of type 1 myocardial infarction or cardiac death within 30 days. RESULTS: We included 437 patients, and the hs-cTnI was collected at 0 and 1 hours in 407 patients and at 0 and 2 hours in 394. The primary outcome occurred in 8.1% (33/407) and 6.9% (27/394) of patients, respectively. All the algorithms classified low-risk patients without missing those with the primary outcome, except for the GRACE pathway. The hs-cTnI-based algorithms classified more patients as low-risk: the ESC 0/1-h 45.7%; the ESC 0/2-h 50.5%; the High-STEACS pathway 68.5%, than those using history and physical findings (15-30%). The High-STEACS pathway ruled out more patients (20.5%) by hs-cTnI measurement at 0 hours than the ESC 0/1-h and 0/2-h algorithms (7.4%). CONCLUSIONS: The hs-cTnI algorithms, especially the High-STEACS pathway, had excellent safety performance for the early diagnosis of myocardial infarction and offered the greatest improvement in efficiency.


Assuntos
Infarto do Miocárdio , Humanos , Biomarcadores , Estudos Prospectivos , Infarto do Miocárdio/diagnóstico , Troponina I , Valor Preditivo dos Testes , Serviço Hospitalar de Emergência , Algoritmos , Troponina T
5.
Water Sci Technol ; 64(2): 416-22, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22097016

RESUMO

For on-site copper recovery in print circuit board factories, we propose a novel technology to obtain cupric oxide with a low content ratio of chloride from high chloride concentration waste, such as cupric chloride etchant waste. Our technology is designed to avoid formation of double salt and accumulation of cupric hydroxide. In the proposed method, etchant waste mixed with hydrogen peroxide solution is added to sodium hydroxide solution by stepwise addition. We performed lab-scale experiments on the influence of reaction pH conditions on the content ratio of chloride in recovering cupric oxide. The results show that recycled cupric oxide tends to contain a lower content ratio of chloride under higher starting temperatures and higher final pH conditions of the reaction. We also confirmed the optimized conditions; the starting temperature of the sodium hydroxide solution is higher than 70 degrees C, and the final pH of the reaction is 11.5 to 12. Based on the optimized temperature and pH conditions, we also performed a pilot trial to recover cupric oxide from real etchant waste. Then, we successfully obtained cupric oxide with a content ratio of chloride in 80 mg-Cl/kg-CuO.


Assuntos
Cobre/química , Cobre/isolamento & purificação , Bifenilos Policlorados/química , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Difração de Raios X
6.
J Exp Med ; 130(6): 1411-25, 1969 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-4982027

RESUMO

PIP: In the present study, controlled burns of 1 testis have induced the formation of testis-specific antibodies in Hartley guinea pigs. The antibodies reacted with autologous as well as homologous testicular extracts. In addition, pathological changes have been noted in the germinal components of the contralateral testis, which were similar to those observed after the induction of experimental allergic orchitis by active immunization with testicular tissue. Results of the study indicate that thermal injury to guinea pig testes can induce an autoimmune response similar to that observed after immunization with autologous or homologous testicular tissue. The antibodies formed were organ-and species-specific against a testicular antigen. Thermal injury may be associated with autoimmunization of the host by the injured organ.^ieng


Assuntos
Formação de Anticorpos , Queimaduras/imunologia , Espermatozoides , Testículo/imunologia , Animais , Reações Antígeno-Anticorpo , Cobaias , Imunodifusão , Imunoeletroforese , Masculino , Anafilaxia Cutânea Passiva , Testículo/patologia , Extratos de Tecidos
7.
J Cell Biol ; 139(3): 785-95, 1997 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-9348294

RESUMO

The dynamic rearrangement of cell-cell junctions such as tight junctions and adherens junctions is a critical step in various cellular processes, including establishment of epithelial cell polarity and developmental patterning. Tight junctions are mediated by molecules such as occludin and its associated ZO-1 and ZO-2, and adherens junctions are mediated by adhesion molecules such as cadherin and its associated catenins. The transformation of epithelial cells by activated Ras results in the perturbation of cell-cell contacts. We previously identified the ALL-1 fusion partner from chromosome 6 (AF-6) as a Ras target. AF-6 has the PDZ domain, which is thought to localize AF-6 at the specialized sites of plasma membranes such as cell-cell contact sites. We investigated roles of Ras and AF-6 in the regulation of cell-cell contacts and found that AF-6 accumulated at the cell-cell contact sites of polarized MDCKII epithelial cells and had a distribution similar to that of ZO-1 but somewhat different from those of catenins. Immunoelectron microscopy revealed a close association between AF-6 and ZO-1 at the tight junctions of MDCKII cells. Native and recombinant AF-6 interacted with ZO-1 in vitro. ZO-1 interacted with the Ras-binding domain of AF-6, and this interaction was inhibited by activated Ras. AF-6 accumulated with ZO-1 at the cell-cell contact sites in cells lacking tight junctions such as Rat1 fibroblasts and PC12 rat pheochromocytoma cells. The overexpression of activated Ras in Rat1 cells resulted in the perturbation of cell-cell contacts, followed by a decrease of the accumulation of AF-6 and ZO-1 at the cell surface. These results indicate that AF-6 serves as one of the peripheral components of tight junctions in epithelial cells and cell-cell adhesions in nonepithelial cells, and that AF-6 may participate in the regulation of cell-cell contacts, including tight junctions, via direct interaction with ZO-1 downstream of Ras.


Assuntos
Células Epiteliais/fisiologia , Cinesinas/fisiologia , Proteínas de Membrana/fisiologia , Miosinas/fisiologia , Fosfoproteínas/fisiologia , Junções Íntimas/fisiologia , Proteínas ras/fisiologia , Animais , Cálcio/fisiologia , Bovinos , Comunicação Celular , Linhagem Celular , Proteínas do Citoesqueleto/metabolismo , Cães , Células Epiteliais/metabolismo , Fibroblastos , Intestinos , Rim , Cinesinas/genética , Cinesinas/metabolismo , Cinesinas/ultraestrutura , Proteínas de Membrana/metabolismo , Proteínas de Membrana/ultraestrutura , Camundongos , Microscopia Imunoeletrônica , Miosinas/genética , Miosinas/metabolismo , Miosinas/ultraestrutura , Ocludina , Células PC12 , Fosfoproteínas/metabolismo , Fosfoproteínas/ultraestrutura , Ratos , Proteínas Recombinantes/metabolismo , Junções Íntimas/metabolismo , Junções Íntimas/ultraestrutura , Proteína da Zônula de Oclusão-1 , alfa Catenina , Proteínas ras/metabolismo
8.
J Cell Biol ; 142(4): 1053-62, 1998 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-9722616

RESUMO

The Ras target AF-6 has been shown to serve as one of the peripheral components of cell-cell adhesions, and is thought to participate in cell-cell adhesion regulation downstream of Ras. We here purified an AF-6-interacting protein with a molecular mass of approximately 220 kD (p220) to investigate the function of AF-6 at cell-cell adhesions. The peptide sequences of p220 were identical to the amino acid sequences of mouse Fam. Fam is homologous to a deubiquitinating enzyme in Drosophila, the product of the fat facets gene. Recent genetic analyses indicate that the deubiquitinating activity of the fat facets product plays a critical role in controlling the cell fate. We found that Fam accumulated at the cell-cell contact sites of MDCKII cells, but not at free ends of plasma membranes. Fam was partially colocalized with AF-6 and interacted with AF-6 in vivo and in vitro. We also showed that AF-6 was ubiquitinated in intact cells, and that Fam prevented the ubiquitination of AF-6.


Assuntos
Adesão Celular/fisiologia , Proteínas de Drosophila , Endopeptidases/fisiologia , Genes ras/genética , Cinesinas/fisiologia , Miosinas/fisiologia , Animais , Encéfalo/metabolismo , Bovinos , Linhagem Celular , Cisteína Endopeptidases/fisiologia , Imunofluorescência , Imuno-Histoquímica , Leupeptinas/farmacologia , Complexos Multienzimáticos/fisiologia , Complexo de Endopeptidases do Proteassoma , Proteínas Recombinantes de Fusão/metabolismo , Transfecção/genética , Ubiquitina Tiolesterase , Ubiquitinas/metabolismo
9.
J Clin Invest ; 47(3): 633-42, 1968 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-4866325

RESUMO

Sensitization of human recipients with transplantation antigens (leucocytes, skin, or kidney allografts) has resulted in the appearance of serum hemagglutinins directed against sheep, guinea pig, and rat erythrocytes. Such hemagglutinins have been identified as IgG and IgM antibodies. Their appearance was not related to AB0 erythrocyte group incompatibility between donors and recipients, and the antibodies were not of the Forssman or Paul-Bunnel type. The antibody responses appeared to be primarily directed against antigen(s) present on rat erythrocytes, but shared to varying extents by other species. The peak antibody titers occurred in association with allograft rejection. In this regard, they may be of interest as a possible early warning system for the diagnosis and prompt management of rejection crises in clinical organ transplantation.


Assuntos
Anticorpos , Imunologia de Transplantes , Absorção , Animais , Anticorpos Anti-Idiotípicos , Antígenos , Antígenos de Grupos Sanguíneos , Incompatibilidade de Grupos Sanguíneos , Centrifugação com Gradiente de Concentração , Eritrócitos , Feminino , Cobaias , Testes de Hemaglutinação , Humanos , Hipersensibilidade Imediata , Imunoeletroforese , Transplante de Rim , Leucócitos/imunologia , Masculino , Mercaptoetanol/farmacologia , Coelhos , Ratos , Ovinos , Transplante de Pele , Transplante Homólogo
10.
Oncogene ; 36(26): 3740-3748, 2017 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-28192407

RESUMO

TTF-1, also known as NKX2-1, is a transcription factor that has indispensable roles in both lung development and physiology. We and others have reported that TTF-1 frequently exhibits high expression with increased copy number in lung adenocarcinomas, and also has a role as a lineage-survival oncogene through transcriptional activation of crucial target genes including ROR1 and LMO3. In the present study, we employed a global proteomic search for proteins that interact with TTF-1 in order to provide a more comprehensive picture of this still enigmatic lineage-survival oncogene. Our results unexpectedly revealed a function independent of its transcriptional activity, as TTF-1 was found to interact with DDB1 and block its binding to CHK1, which in turn attenuated ubiquitylation and subsequent degradation of CHK1. Furthermore, TTF-1 overexpression conferred resistance to cellular conditions under DNA replication stress (RS) and prevented an increase in consequential DNA double-strand breaks, as reflected by attenuated induction of pCHK2 and γH2AX. Our findings suggest that the novel non-transcriptional function of TTF-1 identified in this study may contribute to lung adenocarcinoma development by conferring tolerance to DNA RS, which is known to be inherently elicited by activation of various oncogenes.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Linhagem Celular Tumoral , Quinase 1 do Ponto de Checagem/genética , Quinase 1 do Ponto de Checagem/metabolismo , Quebras de DNA de Cadeia Dupla , DNA de Neoplasias/biossíntese , DNA de Neoplasias/genética , Humanos , Neoplasias Pulmonares/patologia , Fatores de Transcrição , Transcrição Gênica , Ubiquitinação
11.
J Natl Cancer Inst ; 70(5): 811-8, 1983 May.
Artigo em Inglês | MEDLINE | ID: mdl-6341675

RESUMO

By means of indirect immunofluorescence (IIF) tests with rabbit antiserum against Forssman (F) antigen, F-antigen was demonstrated on 5 of 7 cultured cell lines originating from various cancer tissues. Results of cytotoxicity tests with normal human sera with F-antibodies confirmed the presence of F-antigen on these "IIF-positive" cell lines. In contrast, F-antigen could not be detected under the same experimental conditions on B-cell lines established from lymphoma or leukemia patients or on lymphoblastoid cell lines established from normal individuals. The expression of F-antigen was also studied on transformed rat cell lines derived from an F-negative normal cell line, 3y1. Transformation of the 3y1 line by whole DNA or by the EcoRI-C fragment (0-16 map unit) but not by the Accl-H fragment (0-4.7 map unit) of adenovirus type 12 resulted in expression of F-antigen on the cell surface. The transformed cells with F-antigen showed an in vitro growth pattern characteristic of that seen in malignant cells; this observation indicates that F-antigen expression is closely associated with malignant transformation of the cells.


Assuntos
Antígenos Heterófilos/análise , Antígeno de Forssman/análise , Neoplasias/imunologia , Adenoviridae , Animais , Linhagem Celular , Transformação Celular Viral , Testes Imunológicos de Citotoxicidade , Imunofluorescência , Humanos , Neoplasias Experimentais/imunologia , Ratos
12.
J Natl Cancer Inst ; 73(5): 1179-86, 1984 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-6436565

RESUMO

Monoclonal Forssman (F) antibodies of the IgM class were obtained by hybridization of spleen cells from an immunized F344 rat with murine myeloma cells. By means of the indirect immunofluorescence test with monoclonal F-antibodies, F-antigen was demonstrated on rat cell lines derived from a normal cell line that was transformed by transfection with whole adenovirus type 12 DNA or a fragment (E1a + E1b) of adenovirus type 12 DNA. These transformed cells were shown to shed the F-antigen into the culture supernatant, depending on their degree of malignancy. The F-antigen was demonstrated in a glycoprotein, but not in a glycolipid fraction of the supernatants. The glycoprotein purified by affinity chromatography was subjected to gel electrophoresis and subsequent Western blotting. The F-active molecules were identified as three distinct bands of approximately 130,000, 60,000, and 27,000.


Assuntos
Antígenos Heterófilos/análise , Transformação Celular Neoplásica , Antígeno de Forssman/análise , Glicoproteínas/genética , Adenoviridae/genética , Animais , Anticorpos Monoclonais , Complexo Antígeno-Anticorpo , Linhagem Celular , Imunofluorescência , Glicoproteínas/análise , Imunodifusão , Imunoglobulina M , Peso Molecular , Ratos
13.
J Natl Cancer Inst ; 77(1): 115-20, 1986 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3522995

RESUMO

Immunobiological significance of Forssman (F) glycoprotein expressed on rat tumor cells derived from transfection of a fibroblast line with whole DNA (WY-3); EcoRI-C fragment, 0-16.5 map units (CY-1); and Accl-H fragment, 0-4.7 map units (HY-1) of adenovirus 12 was investigated. Culturing of F-positive WY-3 and CY-1 cells, but not F-negative HY-1 cells, with monoclonal rat F-antibody resulted in the blocking of their cell-cell adhesion and attachment to plastic surface and inhibition of their growth. Immunization of WY-3 or CY-1 tumor-bearing F344 rats with sheep red blood cells or purified F-antigen in adjuvants brought regression of the tumor in 13 of 19 rats. No such antitumor effect was observed in F-negative HY-1 tumor-bearing rats upon immunization with the F-antigens. Results of this study indicated that the membrane glycoprotein with F-epitope may play a role in lodgement of the tumor cells in vitro and serve as an in vivo target of specific immune effectors.


Assuntos
Antígenos Heterófilos/imunologia , Antígenos de Superfície/imunologia , Antígeno de Forssman/imunologia , Neoplasias Experimentais/imunologia , Animais , Animais Recém-Nascidos , Anticorpos Monoclonais/biossíntese , Líquido Ascítico/imunologia , Divisão Celular , Linhagem Celular , Transformação Celular Viral , DNA Viral , Imunofluorescência , Antígeno de Forssman/análise , Histocitoquímica , Imunização , Técnicas Imunoenzimáticas , Neoplasias Experimentais/patologia , Ratos , Ratos Endogâmicos F344
14.
J Natl Cancer Inst ; 77(5): 1047-52, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3464796

RESUMO

Tissues of normal human gastric mucosae and 15 advanced gastric carcinomas were studied immunohistologically for the presence of receptors for epidermal growth factor (EGF) by use of a murine monoclonal antibody (528IgG), which reacts with the binding domain of human EGF receptor. On normal gastric mucosae, only parietal cells showed positive staining. On cancer tissues, definite staining was observed in 9 of 15 cases. Their staining intensities were variable and weaker in general compared to those of either gastric parietal cells or normal tonsilar squamous epithelium. No apparent correlation of EGF receptor staining with the grade of histologic differentiation or lymph node metastases of these gastric carcinomas was noted.


Assuntos
Carcinoma/metabolismo , Receptores ErbB/metabolismo , Mucosa Gástrica/metabolismo , Neoplasias Gástricas/metabolismo , Idoso , Anticorpos Monoclonais , Carcinoma/patologia , Epitélio/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/patologia
15.
J Natl Cancer Inst ; 79(5): 923-32, 1987 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2960847

RESUMO

The expression of human histocompatibility leukocyte antigen class II antigens on gastric epithelia and gastric carcinoma (GaCa) was studied with the use of murine monoclonal antibodies to DR, DQ, and DP antigens. DR and DP antigens but not DQ antigens were demonstrated in fundic glands of normal gastric epithelia, and DP+ cells were located in part of the DR+ epithelia. Of 15 GaCas examined, 11 expressed DR antigen, and the degree of the expression varied considerably among the specimens. DP antigen was found in 3 of the 11 DR+ carcinomas, and the DQ antigen was found in one of the 3 DR+ DP+ specimens. Thus the expression of class II antigens in normal gastric epithelia and GaCas appears to be in the order of DR, DP, and DQ. Studies on 3 GaCa cell lines (Kato III, MKN28, and MKN45) demonstrated that 1 line (Kato III) expressed DR antigen only, and the remaining lines were negative. Interferon (IFN)-gamma treatment enhanced the expression of DR antigen on Kato III cells and induced expression of DQ and DP antigens. The IFN-gamma treatment also induced expression of DR antigen but not DQ or DP antigens in 1 of the 2 negative cell lines. The induction of the class II antigens by IFN-gamma was shown to be dose dependent. However, maximal induction of DQ and DP antigens on the Kato III cells and DR antigens on MKN45 cells required 10 times more IFN-gamma than that needed for the maximal expression of DR antigen on Kato III. Northern blot analyses of cytoplasmic RNA from these cells were in agreement with and affirmed the above-described expression of the class II antigens on the cell lines. The DR antigen on the Kato III cells was capable of stimulating allogeneic lymphocytes in MLR, and its stimulatory activity was significantly enhanced by IFN-gamma. These results demonstrated a differential expression of class II antigens in the "DR, DP, and DQ order" in normal gastric epithelia, GaCa cells, and GaCa cell lines, suggesting different mechanisms acting discordantly on the expression of each of these antigens and that the DR antigen on the GaCa cell lines possesses MLR-stimulatory ability.


Assuntos
Mucosa Gástrica/imunologia , Antígenos HLA-D/análise , Antígenos HLA-DP/análise , Antígenos HLA-DQ/análise , Antígenos HLA-DR/análise , Neoplasias Gástricas/imunologia , Animais , Anticorpos Monoclonais/imunologia , Epitélio/imunologia , Regulação da Expressão Gênica , Antígenos HLA-DP/genética , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Humanos , Ativação Linfocitária , Teste de Cultura Mista de Linfócitos , Camundongos , RNA Neoplásico/análise , Células Tumorais Cultivadas/imunologia
16.
Biochim Biophys Acta ; 599(2): 403-16, 1980 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6893280

RESUMO

The singlet-singlet energy transfer from alloxazines to isoalloxazines has been investigated in dialmitoyl phosphatidylcholine (DPPC) liposomes and dioctadecyltrimethylammonium chloride (2C18NC) vesicles to clarify the role of the artificial membranes in the energy transfer phenomenon. The structures of the artificial membranes were divided into two types: the single-walled (sonicated DPPC) and the multi-compartment vesicles (unsonicated DPPC and sonicated 2C18NC). In the DPPC single-walled liposomes, the energy of the donor lost by quenching is efficiently transferred to the acceptor via the Förster-type dipoledipole interaction. In the case of multi-compartment liposomes of DPPC, the mean distance between donor and acceptor is so small because the external surface of a bilayer is in the vicinity of the internal surface of another bilayer. As a consequence, efficiencies both of energy transfer and of energy loss were greater than those in single-walled liposomes. The fluid property of the 2C18NC bilayer allowed the preferential collisional quenching. The marked reduction in the efficiencies of both energy transfer and energy loss were attributed to the elongation of donor-acceptor distances due to the increase of the size of liposome.


Assuntos
Flavinas , Lipossomos , Membranas Artificiais , Surfactantes Pulmonares , Compostos de Amônio Quaternário , Transferência de Energia , Bicamadas Lipídicas , Matemática , Espectrometria de Fluorescência
17.
Biochim Biophys Acta ; 509(2): 289-99, 1978 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-26400

RESUMO

Pyranine is shown to be a convenient and sensitive probe for reporting pH values, pHi, at the interior of anionic and at the outer surface of cationic liposomes. It is well shielded from the phospholipid headgroups by water molecules in the interior of anionic liposomes, but it is bound to the surface of cationic liposomes. Hydrogen ion concentrations outside the liposomes, 'bulk pH values', pHo, were measured by a combination electrode. While pHi = pHo for neutral, pHi less than pHo for anionic and pHi greater than pHo for cationic liposomes prepared in 5.0 . 10(-3) M phosphate buffers. pKa values for the ionization of pyranine were 7.22 +/- 0.04 and 6.00 +/- 0.05 in water and at the external surface of cationic liposomes. The surface potential for cationic liposomes containing dipalmitoyl-DL-alpha-phosphatidylcholine, cholesterol and octadecylamine in the molar ratio of 1.00 : 0.634 : 1.01, were calcuated to be +72.2 mV. Proton permeabilities were measured for single and multicompartment anionic liposomes. Transfer of anionic liposomes prepared at a given pH to a solution of different pH resulted in a pH gradient if sodium phosphate or borate were used as buffers. In the presence of sodium acetate proton equilibration is promptly established.


Assuntos
Sulfonatos de Arila , Concentração de Íons de Hidrogênio , Lipossomos , Pirenos , Aminas , Colesterol , Surfactantes Pulmonares
18.
Biochim Biophys Acta ; 1157(3): 324-31, 1993 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-8391846

RESUMO

Electrochemical characterization of topa quinone (6-hydroxydopa quinone), the organic cofactor of copper-containing amine oxidases, has been performed with the aid of spectroscopy and ab initio energy minimization technique. Topa quinone exhibits a totally reversible cyclic voltammogram at a mercury electrode, which is ascribed to a two-step one-electron conversion between topa quinone and topa via topa semiquinone intermediate. Digital simulation of the reversible wave has afforded the separated estimation of each one-electron redox potential. The acid-dissociation constants of the phenolic hydroxyl groups of topa quinone, topa semiquinone and topa have been evaluated electrochemically and supported by electronic and electron spin resonance spectra. At pH 7.0, topa quinone is acid-dissociated and has a two-electron redox potential of 0.079 V vs. NHE coupled with a three-proton transfer. Redox catalytic activity of topa quinone for the oxidation of amines and NADH was not observed over conventional voltammetric time periods. Energy minimization calculation of acid-dissociated topa quinone anion indicates an intermediate electronic structure between the p- and o-quinone types with three almost equivalent carbonyl groups. The lack of the redox catalytic activity of free topa quinone appears to be attributable to the partial contribution of the p-quinone-type structure.


Assuntos
Benzoquinonas/química , Di-Hidroxifenilalanina/análogos & derivados , Fenilalanina/análogos & derivados , Eletroquímica , Espectroscopia de Ressonância de Spin Eletrônica , Concentração de Íons de Hidrogênio , Oxirredução , Fenilalanina/química
19.
Biochim Biophys Acta ; 1428(2-3): 241-50, 1999 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-10434042

RESUMO

2-Amino-3-carboxy-1,4-naphthoquinone (ACNQ) is a novel growth stimulator for bifidobacteria. The role of ACNQ as a mediator of the electron transfer from NAD(P)H to dioxygen (O(2)) and hydrogen peroxide (H(2)O(2)), proposed in our previous paper, was examined using the cell-free extract and whole cells of Bifidobacterium longum. Continuous monitoring of ACNQ, O(2) and H(2)O(2) by several amperometric techniques has revealed that ACNQ works as a good electron acceptor of NAD(P)H diaphorase and that the reduced form of ACNQ is easily autoxidized and also acts as a better electron donor of NAD(P)H peroxidase than NAD(P)H. The generation of H(2)O(2) by B. longum under aerobic conditions is effectively suppressed in the presence of ACNQ. These ACNQ-mediated reactions would play roles as NAD(P)(+)-regeneration processes. The accumulation of ACNQ in the cytosol has been also suggested. These characteristics of ACNQ seem to be responsible for the growth stimulation of bifidobacteria. Vitamin K(3), which has an extremely low growth-stimulating activity and was used as a reference compound, exhibits much lower activity as an electron transfer mediator. The difference in the activity is discussed in terms of the redox potential and partition property of the quinones.


Assuntos
Bifidobacterium/efeitos dos fármacos , Substâncias de Crescimento/farmacologia , NADP/metabolismo , Naftoquinonas/farmacologia , Anaerobiose , Bifidobacterium/metabolismo , Sistema Livre de Células , Di-Hidrolipoamida Desidrogenase/metabolismo , Eletroquímica , Transporte de Elétrons/efeitos dos fármacos , Peróxido de Hidrogênio/análise , Complexos Multienzimáticos/metabolismo , NADH NADPH Oxirredutases/metabolismo , NADP/química , NADPH Desidrogenase/metabolismo , Oxirredução , Oxigênio/análise , Termodinâmica
20.
Biochim Biophys Acta ; 1389(2): 132-40, 1998 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9461254

RESUMO

Dolichyl phosphate, an essential carrier lipid in the biosynthesis of N-linked glycoprotein, has been found to induce apoptosis in rat glioma C6 cells and human monoblastic leukemia U937 cells. In the present study, dolichyl phosphate and structurally related compounds were examined regarding their apoptosis-inducing activities in U937 cells. Dihydroheptaprenyl and dihydrodecaprenyl phosphates, of which isoprene units are shorter than that of dolichyl phosphate, induced apoptosis in U937 cells. This phenomenon occurred in a dose- and time-dependent manner, as seen with dolichyl phosphate-induced apoptosis. Derivatives of the same isoprene units of dolichyl phosphate, such as dolichol, dolichal or dolichoic acid, did not induce DNA fragmentation. Farnesyl phosphate and geranylgeranyl phosphate also failed to induce apoptosis. During apoptosis, the caspase family of cysteine proteases play important roles. We observed that apoptosis induced by dihydroprenyl phosphate was mediated by caspase-3-like (CPP32-like) activation but not by caspase-1-like (ICE-like) activation. This caspase-3-like activation was inhibited by a specific inhibitor of caspase-3, DEVD-CHO, but not by an caspase-1 inhibitor YVAD-CHO. We interpret these results to mean that dihydroprenyl phosphates with more than seven isoprene units have apoptosis-inducing activity and that their signal is mediated by caspase-3-like activation.


Assuntos
Apoptose/efeitos dos fármacos , Caspases , Cisteína Endopeptidases/metabolismo , Fosfatos de Poli-Isoprenil/farmacologia , Caspase 1 , Caspase 3 , Cumarínicos/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Fragmentação do DNA/efeitos dos fármacos , Fosfatos de Dolicol/farmacologia , Ativação Enzimática , Humanos , Leucemia/metabolismo , Estrutura Molecular , Oligopeptídeos/metabolismo , Oligopeptídeos/farmacologia , Células Tumorais Cultivadas
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