Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 99
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Exp Med ; 152(1): 85-98, 1980 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-7400757

RESUMO

The mechanisms by which macrophages kill ingested microorganisms were explored using Candida albicans and Candida parapsilosis. The results indicate that efficient macrophage candidacidal activity depends upon the generation of oxygen metabolites by the phagocytic cell: (a) peritoneal macrophages from mice infected with bacillus Calmette-Guerin (BCG) or injected intraperitoneally with lipopolysaccharide (LPS) released more superoxide anion (0(2)(-)) during phagocytosis of candida and killed candida better than did resident macrophages; (b) cells of the macrophage-like line J774.1, which released negligible amounts of O(2)(-), could ingest the candida normally but not kill them; (c) killing of candida by resident, LPS- elicited, and BCG-activated macrophages was inhibited by agents that scavenge O(2)(-), hydrogen peroxide (H(2)0(2)), hydroxyl radical (x OH), and singlet oxygen; and (d) all three macrophage types killed C. parapsilosis more effectively than C. albicans, and (7. parapsilosis stimulated a more prompt and vigorous burst of macrophage oxygen consumption and 0(2)(-) release than did C. albicans. Macrophages ingested C. parapsilosis slightly more quickly than C. albicans, but phagocytosis of both strains was equivalent by 60 min of incubation. Although C. albicans contained higher concentrations of the oxygen-metabolite scavengers superoxide dismutase and catalase, neither fungal species scavenged 0(2)(-) or H(2)0(2) effectively; and C. albicans was killed more easily than C. parapsilosis by a xanthine oxidase system that generates primarily H(2)O(2) at pH 7, or 0(2)(-) and x OH at pH 10. Thus, the decreased killing of C. albicans appears to result primarily from the capability of this species to elicit less vigorous stimulation of macrophage oxidative metabolism. This capability may have general relevance to the pathogenicity of microorganisms.


Assuntos
Candida/imunologia , Macrófagos/imunologia , Fagocitose , Animais , Fenômenos Fisiológicos Sanguíneos , Candida/enzimologia , Catalase/farmacologia , Células Cultivadas , Concentração de Íons de Hidrogênio , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Camundongos , Oxirredução , Consumo de Oxigênio , Superóxido Dismutase/farmacologia , Fatores de Tempo
2.
J Exp Med ; 152(4): 808-22, 1980 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-6252274

RESUMO

Whereas phagocytic cells from normal individuals have the capacity to kill ingested bacteria and parasites, those from patients with several uncommon genetic deficiency diseases are known to be defective in bactericidal activity. Studies on neutrophils of these patients have revealed fundamental defects in their ability to reduce molecular oxygen and metabolize it to superoxide anion, hydrogen peroxide, and oxygen radicals. In the present experiments, we describe a clone of a continuous murine macrophage-like cell line, J774.16, that, upon appropriate stimulation, activates the hexose monophosphate shunt, and produces superoxide anion and hydrogen peroxide. With nitroblue tetrazolium to select against cells capable of being stimulated by phorbol myristate acetate to reduce the dye to polymer--formazan--which is toxic fot cells, we have selected for variants that are defective in oxygen metabolism. Four of these subclones have been characterized and found to be lacking in the ability (a) to generate superoxide anion, as measured by cytochrome c reduction; (b) to produce hydrogen peroxide, as measured by the ability to form complex I with cytochrome c peroxidase; and (c) to be stimulated to oxidize glucose via the hexose monophosphate shunt. These variants appear to represent a useful model for studying the molecular basis for macrophage cytocidal activity.


Assuntos
Variação Genética , Macrófagos/metabolismo , Oxigênio/biossíntese , Superóxidos/biossíntese , Animais , Linhagem Celular , Células Clonais , Glucose/metabolismo , Peróxido de Hidrogênio/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Oxirredução , Fagocitose , Sarcoma Experimental
3.
J Exp Med ; 187(4): 587-600, 1998 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-9463409

RESUMO

Two novel synthetic tetrapeptides, VEID-CHO and DMQD-CHO, could selectively inhibit caspase-6 and caspase-3, respectively. We used these inhibitors to dissect the pathway of caspase activation in Fas-stimulated Jurkat cells and identify the roles of each active caspase in apoptotic processes. Affinity labeling techniques revealed a branched protease cascade in which caspase-8 activates caspase-3 and -7, and caspase-3, in turn, activates caspase-6. Both caspase-6 and -3 have major roles in nuclear apoptosis. Caspase-6 cleaves nuclear mitotic apparatus protein (NuMA) and mediates the shrinkage and fragmentation of nuclei. Caspase-3 cleaves NuMA at sites distinct from caspase-6, and mediates DNA fragmentation and chromatin condensation. It is also involved in extranuclear apoptotic events: cleavage of PAK2, formation of apoptotic bodies, and exposure of phosphatidylserine on the cell surface. In contrast, a caspase(s) distinct from caspase-3 or -6 mediates the disruption of mitochondrial membrane potential (permeability transition) and the shrinkage of cytoplasm. These findings demonstrate that caspases are organized in a protease cascade, and that each activated caspase plays a distinct role(s) in the execution of Fas-induced cell death.


Assuntos
Apoptose , Caspases , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Oligopeptídeos/farmacologia , Receptor fas/fisiologia , Antígenos Nucleares , Autoantígenos/metabolismo , Caspase 3 , Caspase 6 , Caspase 7 , Caspase 8 , Caspase 9 , Proteínas de Ciclo Celular , Fragmentação do DNA , Ativação Enzimática , Citometria de Fluxo , Humanos , Células Jurkat , Proteínas Associadas à Matriz Nuclear , Proteínas Nucleares/metabolismo , Fuso Acromático/metabolismo
4.
Cancer Res ; 43(7): 3412-6, 1983 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6850647

RESUMO

N4-Behenoyl-1-beta-D-arabinofuranosylcytosine (BHAC), a lipophilic and deaminase-resistant derivative of 1-beta-D-arabinofuranosylcytosine (ara-C), was studied pharmacologically in patients with acute leukemia. The concentrations of BHAC, ara-C, and 1-beta-D-arabinofuranosyluracil were measured by high-performance liquid chromatography, bioassay, and gas chromatography-mass spectrometry-mass fragmentography, respectively. The data of plasma BHAC concentrations were analyzed by a MULTI computer program. In seven patients given BHAC (200 mg/body weight; 2.97 to 4.26 mg/kg) i.v. for 90 min, the plasma disappearance curve of BHAC was biphasic with a mean initial half-life of 0.37 hr and a mean second half-life of 5.27 hr. The apparent volume of the central compartment and the apparent volume of distribution were 0.047 and 0.316 liter/kg, respectively; the systemic clearance was 0.051 liter/hr/kg. BHAC concentrations in erythrocytes were significantly higher (p less than 0.01) than those in plasma at 4 to 22.5 hr after infusion, suggesting that the erythrocytes may act as a reservoir for the drug. The plasma 1-beta-D-arabinofuranosyluracil level increased to 603 ng/ml at 4 hr after infusion, and it was over 129 ng/ml for at least 22.5 hr after infusion. Plasma ara-C levels, which could be detected in only 2 of 11 patients examined, were maintained (over 0.08 micrograms/ml) for 8 hr after infusion. Urinary BHAC excretion was less than 0.2 micrograms/ml of the sensitivity limit in all samples. Prolonged urinary ara-C excretion was detected, but it was only 0.5% of the administered BHAC for 24 hr. At 12 hr after a 200-mg infusion of BHAC, BHAC level in bone marrow fluid was significantly higher (p less than 0.01) than that in plasma. In spite of the lipophilic nature of the agent, the BHAC concentration in cerebrospinal fluid was less than 0.2 micrograms/ml in 8 of 9 patients without meningeal involvement. These findings were thought to indicate a restricted and prolonged BHAC distribution including plasma, blood cells, and bone marrow fluids, which may be of importance in the administration of BHAC in the chemotherapy of hematological cancers.


Assuntos
Antineoplásicos/metabolismo , Citarabina/análogos & derivados , Leucemia/metabolismo , Doença Aguda , Adulto , Arabinofuranosiluracila/metabolismo , Medula Óssea/metabolismo , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Citarabina/metabolismo , Eritrócitos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Lactente , Infusões Parenterais , Cinética , Leucemia/sangue , Leucemia/líquido cefalorraquidiano , Pessoa de Meia-Idade , Fatores de Tempo
5.
Cancer Res ; 46(12 Pt 1): 6400-5, 1986 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3465438

RESUMO

The YK-M2 cell line was established from the peripheral blood of a patient with acute monoblastic leukemia in whom an anterior mediastinal tumor preceded the peripheral blood manifestation. The established cells grew in a single cell suspension with a doubling time of 60 h and consisted of primitive monoblastic cells. The cells were 52% positive for peroxidase staining and manifested strongly positive activity of alpha-naphthyl acetate esterase, which was completely inhibited by sodium fluoride. The cells showed strong expression of Fc gamma receptors and phagocytosed sensitized ox erythrocytes. When the cells were incubated with 1 alpha,25-dihydroxy-vitamin D3, they were induced to differentiate into mature monocyte-macrophage-like cells, which reduced the nitroblue tetrazolium dye and released a small amount of the superoxide anion. Cytogenetic studies revealed that the cells had a near-triploid karyotype with a modal chromosome number of 68, and the short arm of one No. 17 chromosome was deleted [del(17)(p11)]. The YK-M2 cell line is particularly unique in that the cells retained the polyploid karyotype that may be an initial cytogenetic change in the malignant transformation of the parent leukemia cells.


Assuntos
Aberrações Cromossômicas , Leucemia Monocítica Aguda/genética , Poliploidia , Adulto , Calcitriol/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Humanos , Cariotipagem , Leucemia Monocítica Aguda/imunologia , Leucemia Monocítica Aguda/patologia , Masculino
6.
Oncogene ; 14(23): 2741-52, 1997 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-9190889

RESUMO

The activation of multiple interleukin-1beta converting enzyme-related proteases (caspases) in apoptotic mammalian cells raises questions as to whether the multiple active caspases have distinct roles in apoptotic execution as well as how these proteases are organized in apoptotic signaling pathways. Here we used an affinity-labeling agent, YV(bio)KD-aomk, to investigate the caspases activated during apoptotic cell death. YV(bio)KD-aomk identified six distinct polypeptides corresponding to active caspases in Fas-stimulated Jurkat T cells. On staurosporine treatment, four polypeptides were detected. Competition experiments showed that the labeled caspases have distinct substrate preferences. Stepwise appearance of the labeled caspases in each cell death event was consistent with the view that the activated caspases are organized into protease cascades. Moreover, we found that stepwise activation of caspases similar to that induced by Fas ligation is triggered by exposing non-apoptotic Jurkat cell extracts to caspase-8 (MACH/FLICE/Mch5). Conversely, CrmA protein, a viral suppressor of Fas-induced apoptosis, inhibited the protease activity of caspase-8. Overall, these findings provide evidence that caspase-8, a CrmA-sensitive protease, is responsible for initiating the stepwise activation of multiple caspases in Fas-stimulated cells.


Assuntos
Apoptose , Caspases , Cisteína Endopeptidases/metabolismo , Proteínas Virais , Marcadores de Afinidade/metabolismo , Animais , Caspase 6 , Caspase 8 , Caspase 9 , Galinhas , Inibidores de Cisteína Proteinase/farmacologia , Ativação Enzimática , Humanos , Células Jurkat , Laminina/metabolismo , Oligopeptídeos/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Serpinas/farmacologia , Estaurosporina/farmacologia , Especificidade por Substrato , Receptor fas/farmacologia
7.
J Leukoc Biol ; 60(2): 191-8, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8773580

RESUMO

Stimulation of the respiratory burst in phagocytes induces the formation of mixed disulfides between sulfhydryl groups of proteins and low-molecular-weight thiols. We hypothesized that this process (S-thiolation) might be involved in turning off the respiratory burst. However, induction of S-thiolation by pretreatment of neutrophils with diamide, a direct thiol oxidizing agent, actually primed the cells for a two- to fivefold increase in total release and fourfold increase in rate of release of 02- on stimulation by f-Met-Leu-Phe. Generation of intracellular oxidants (hydroethidine fluorescence) was increased ninefold. Priming and S-thiolation were apparent at 1 min of incubation and peaked at 5-10 min. Diamide pretreatment also reduced the lag time between addition of phorbol diester and release of 02- by a mean of 23 s (41%). Dithioerythritol, a sulfhydryl-reducing agent, abolished both the S-thiolation and priming mediated by diamide. H202 also induced priming and S-thiolation; and these were eliminated by dithioerythritol. In contrast to the effect of endotoxin, diamide priming did not affect Ca2+ homeostasis of the neutrophils. Diamide did not significantly alter NADPH oxidase activity in a cell-free system. These findings suggest that sulfhydryl groups on one or more proteins play an important role in modulating the respiratory burst.


Assuntos
Proteínas Sanguíneas/metabolismo , Diamida/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Compostos de Sulfidrila/sangue , Superóxidos/metabolismo , Cálcio/sangue , Cálcio/farmacologia , Humanos , Peróxido de Hidrogênio/farmacologia , Líquido Intracelular/metabolismo , Lipopolissacarídeos/farmacologia , NADH NADPH Oxirredutases/metabolismo , NADPH Oxidases , Fator de Ativação de Plaquetas/farmacologia
8.
J Leukoc Biol ; 41(4): 289-94, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3033107

RESUMO

Freshly isolated human monocytes ingested and killed Candida albicans, and generated O2- H2O2 and .OH efficiently. When monocytes were cultured in vitro, these cells transformed into macrophages. Cultured monocytes retained their ingestive activity but lost their candidacidal activity almost completely after day 3. The release of O2- by monocytes decreased slightly with culture and that of .OH was markedly decreased on day 3 of culture. The activity of myeloperoxidase in the monocytes decreased with culture. These results suggested that the loss of candidacidal activity is due to the decrease of .OH generation and myeloperoxidase activity in cultured monocytes.


Assuntos
Fenômenos Fisiológicos Sanguíneos , Candida albicans , Macrófagos/fisiologia , Monócitos/fisiologia , Oxigênio/metabolismo , Candida albicans/imunologia , Células Cultivadas , Radicais Livres , Humanos , Peróxido de Hidrogênio/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Monócitos/enzimologia , Peroxidase/metabolismo , Fagocitose/efeitos dos fármacos , Superóxido Dismutase/farmacologia , Superóxidos/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Tempo
9.
J Leukoc Biol ; 62(2): 203-9, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9261334

RESUMO

We explored the effect of leukotriene B4 (LTB4) on endothelial cells in LTB4-induced transendothelial migration (TEM) of neutrophils as an in vitro model of neutrophil extravasation. Chemotactic response of human neutrophils to LTB4 was significantly lower than that in response to N-formyl-methionyl-leucyl-phenylalanine (fMLP), whereas the extent of TEM in response to LTB4 was significantly higher than that to fMLP. The study on random migration induced by LTB4 and fMLP also showed similar results, which indicated that LTB4 might affect the human umbilical cord vein endothelial cell (HUVEC) barrier. Neutrophil TEM was induced by pretreatment of HUVEC monolayer with LTB4 but not with fMLP. Treatment of endothelial cells by ONO-4057, a LTB4 receptor antagonist, abolished the effect of LTB4 almost completely whereas neutrophils treated with ONO-4057 could transmigrate through HUVEC treated with LTB4. These findings indicated that LTB4 could induce neutrophil TEM by acting on HUVEC.


Assuntos
Endotélio Vascular/citologia , Leucotrieno B4/farmacologia , Neutrófilos/citologia , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Quimiotaxia de Leucócito/efeitos dos fármacos , Dactinomicina/farmacologia , Humanos , Interleucina-8/biossíntese , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Fenilpropionatos/farmacologia , Receptores do Leucotrieno B4/antagonistas & inibidores
10.
J Leukoc Biol ; 61(4): 500-6, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9103237

RESUMO

Granulocyte-macrophage colony-stimulating factor (GM-CSF) induced random migration of human polymorphonuclear leukocytes (PMNs) but not chemotaxis. Chemoattractants such as N-formyl-methionyl-leucyl-phenylalanine (fMLP), leukotriene B4 (LTB4), and interleukin-8 (IL-8) induced both random migration and chemotaxis. Other inflammatory cytokines, including granulocyte colony-stimulating factor (G-CSF), interleukin 1alpha (IL-1alpha), and tumor necrosis factor alpha (TNF-alpha), did not induce either movement. One-minute exposure of PMNs to GM-CSF was sufficient for the induction of random migration, whereas fMLP-induced random migration required continued presence of fMLP. Inhibitors of phosphatidylinositol 3-kinase (PI3-K), protein kinase C (PKC), and protein tyrosine kinase (PTK) had no effect on random migration induced by GM-CSF, whereas fMLP-induced movements were partially inhibited by PTK inhibitors but not by inhibitors of PI3-K inhibitors nor PKC inhibitors. Myosin light chain kinase inhibitors inhibited movements of PMNs induced by both GM-CSF and fMLP. These findings also imply that some aspects of the signal transduction pathway of GM-CSF leading to random migration is different from that of fMLP. Our findings suggest that cell movements are controlled through diverse signal transduction systems.


Assuntos
Quimiotaxia de Leucócito/efeitos dos fármacos , Quimiotaxia de Leucócito/fisiologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/fisiologia , Transdução de Sinais/fisiologia , Androstadienos/farmacologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Cromonas/farmacologia , Citocinas/farmacologia , Inibidores Enzimáticos/farmacologia , Proteínas de Ligação ao GTP/antagonistas & inibidores , Fator Estimulador de Colônias de Granulócitos/farmacologia , Humanos , Morfolinas/farmacologia , Neutrófilos/citologia , Proteína Quinase C/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Wortmanina
11.
Free Radic Biol Med ; 30(3): 248-59, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11165871

RESUMO

The chemical property of 6-formylpterin and its biological functions were examined. Polarographic studies revealed that 6-formylpterin reacted with NAD(P)H and consumed oxygen. In contrast, other conjugated pterins, such as biopterin and neopterin, showed no consumption of oxygen. The production analysis using high-performance liquid chromatography documented that 6-formylpterin catalyzes the conversion from NADH to NAD. Electroparamagnetic resonance spin trapping experiments demonstrated that this reaction is accompanied with the generation of reactive oxygen species (ROS), superoxide anion and hydrogen peroxide. When 6-formylpterin was administered to HL-60 cells, intracellular ROS generation was observed and apoptosis was induced. In contrast, other conjugated pterins induced neither intracellular ROS generation nor apoptosis in HL-60 cells. The intracellular ROS generation by 6-formylpterin was observed in other cells, such as PanC-1 cells and Jurkat cells. 6-formylpterin suppressed cell proliferation in PanC-1 cells and inhibited Fas-mediated apoptosis in Jurkat cells. These findings indicate that, among conjugated pterins, 6-formylpterin has the unique property to transfer electron from NAD(P)H to oxygen and that the property brings about intracellular ROS generation, which exerts various biological functions such as induction of apoptosis, suppression of cell proliferation, and inhibition of Fas-mediated apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Pteridinas/farmacologia , Pterinas , Espécies Reativas de Oxigênio/metabolismo , Xantina Oxidase/antagonistas & inibidores , Catalase/farmacologia , Quelantes/farmacologia , Cromatografia Líquida de Alta Pressão , Desferroxamina/farmacologia , Eletroquímica , Espectroscopia de Ressonância de Spin Eletrônica , Inibidores Enzimáticos/metabolismo , Células HL-60 , Humanos , Peróxido de Hidrogênio/metabolismo , Células Jurkat , NAD/metabolismo , Nucleotídeos/análise , Oxirredução , Consumo de Oxigênio/efeitos dos fármacos , Pteridinas/química , Pteridinas/metabolismo , Superóxidos/metabolismo , Receptor fas/fisiologia
12.
Leuk Res ; 8(1): 63-9, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6700261

RESUMO

A 46-year-old man had acute leukemia with two cell populations of lymphoblasts and monoblasts (L1 and M5-b in FAB classification, respectively), which were characterized by morphological, cytochemical and cell marker studies. At the time of diagnosis about 80% blasts were terminal deoxynucleotidyl transferase (TdT) positive lymphoid cells, while the rest were TdT negative monocytoid cells. After induction chemotherapy of vindesine and prednisolone for 15 days, almost all blasts were TdT negative monocytoid cells. Therefore, an additional course of the chemotherapy with the protocol for acute nonlymphocytic leukemia was given and one month later the patient achieved complete remission.


Assuntos
Leucemia/patologia , Linfócitos/patologia , Monócitos/patologia , Antígenos de Superfície/análise , Medula Óssea/patologia , Humanos , Masculino , Pessoa de Meia-Idade
13.
Int J Hematol ; 60(1): 51-7, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7919238

RESUMO

We recently reported that human macrophages effectively destroyed leukemic cells. In this study, we investigated the mechanism of leukemic cell lysis by human macrophages. Human peripheral blood monocyte-derived macrophages were activated with interferon-gamma and lipopolysaccharide. Activated macrophages exhibited lytic activity against leukemic cells (K562 and HL-60 cells) by cocultivation. When macrophages and these leukemic cells were separated by a microporous membrane, activated macrophages did not show any lytic activity against these leukemic cells. However, activated macrophages interacting with leukemic cells under the microporous membrane exhibited lytic activity against leukemic cells that were placed on the microporous membrane. Different kinds of leukemic cells were also effective to induce such lytic activity in the macrophages, but normal lymphocytes could not. Culture supernatants of activated macrophages incubated with leukemic cells did not have cytolytic activity against leukemic cells. The leukemic cells used in this study were confirmed to be resistant to tumor necrosis factor (TNF), but the activated macrophage-mediated cytolytic activity was significantly inhibited by the anti-TNF antibody. These findings suggested that the contact between macrophages and leukemic cells triggered the secretion of lytic factor(s), and that TNF and other labile factor(s) co-operatively functioned to lyse leukemic cells.


Assuntos
Citotoxicidade Imunológica/fisiologia , Leucemia/patologia , Ativação de Macrófagos , Macrófagos/imunologia , Humanos , Células Tumorais Cultivadas/patologia , Fator de Necrose Tumoral alfa/fisiologia
14.
Int J Hematol ; 66(1): 69-78, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9220662

RESUMO

Phagocytosis and oxygen radical generation by human polymorphonuclear leukocytes (PMNLs) were studied by a two-color flow cytometric analysis, where the red fluorescent product(s) of hydroethidine was used as an indicator of intracellular generation of oxygen radicals and opsonized zymosan (OZ) as an indicator of phagocytosis. Unstimulated cells formed a single population of cells without any significant fluorescence. PMNLs stimulated by OZ exhibited a high red fluorescence. Most PMNLs phagocytosed OZ and generated oxygen radicals when stimulated by zymosan particles opsonized with human AB serum at concentrations of more than 10%, whereas three distinct subpopulations (designated as R1, R2 and R3) appeared when stimulated by zymosan particles opsonized with 3% serum; R1 cells enhanced neither green nor red fluorescence, R2 cells enhanced green fluorescence but not red fluorescence, and R3 cells enhanced both green and red fluorescence. The R2 cells completely disappeared by the addition of Trypan blue. Most of the R3 cells disappeared by the addition of cytochalasin B. These findings on the three fractions were confirmed by the observation under fluorescence microscopy of cells in each fraction obtained by sorting. In conclusion, PMNLs could be separated into three functionally distinct subpopulations when stimulated by zymosan particles opsonized with a suboptimal concentration of serum.


Assuntos
Citometria de Fluxo/métodos , Neutrófilos/citologia , Fagocitose , Diferenciação Celular , Radicais Livres , Humanos , Neutrófilos/metabolismo , Neutrófilos/fisiologia , Explosão Respiratória
15.
Int J Hematol ; 72(1): 48-54, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10979209

RESUMO

Receptors for the Fc region (FcR) of immunoglobulin (Ig)G play essential roles in effector functions of polymorphonuclear leukocytes (PMNs) including the antibody-mediated clearance of microbes. In contrast to the constitutive expression of the low-affinity receptors for IgG (Fc gamma RII [CD32] and Fc gamma RIII [CD16]), the high-affinity receptor Fc gamma RI (CD64) is barely detectable on unactivated PMNs. CD64 expression is induced in a slow kinetic manner by interferon (IFN)-gamma and granulocyte colony-stimulating factor (G-CSF) after 12 to 24 hours of exposure to these agents. We found that the cross-linking of CD11b as well as of CD18 induced comparable rapid increases in CD64 expression on the surface of PMNs, occurring within 15 minutes of exposure. Cross-linking of neither CD11a nor CD11c induced CD64 expression. In contrast to slow induction by IFN-gamma and G-CSF, the integrin-induced rapid CD64 expression did not require RNA synthesis. Genistein, herbimycin A, and 1,2-bis(o-aminophenoxy)ethan-N,N-N',N'-tetraacetic acid blocked the immediate expression of CD64 in a dose-dependent manner, suggesting that the signal is mediated through calcium mobilization and protein tyrosine kinase(s). Such rapid modulation of the high-affinity Fc gamma RI receptor by integrin cross-linking may reflect the requirement for rapid up-regulation of PMN effector functions, after interaction with endothelial cells, platelets or bacteria.


Assuntos
Antígenos CD18/metabolismo , Neutrófilos/metabolismo , Receptores de IgG/metabolismo , Regulação para Cima , Antígenos CD11/metabolismo , Antígenos CD11/farmacologia , Antígenos CD18/farmacologia , Citocalasina B/farmacologia , Humanos , Neutrófilos/imunologia , Neutrófilos/fisiologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Receptores de IgG/efeitos dos fármacos , Receptores de IgG/fisiologia , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
16.
Cancer Genet Cytogenet ; 130(1): 42-50, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11672773

RESUMO

We describe the establishment and characterization of a new multiple myeloma (MM) cell line, KYdelta-1, which expressed delta/kappa type immunoglobulin (Ig). The patient was a 65-year-old woman with MM, who presented extramedullary dissemination, lymphadenopathy and short survival. The KYdelta-1 cell line was derived from the pleural fluid obtained in the terminal phase of the disease. The cells expressed delta/kappa Ig in the cytoplasm, and CD10, CD29, CD33, CD38, CD44, CD54, and HLA-DR antigens on the cell surface. Chromosomal analysis revealed two independent translocations, t(3;14)(p21;q32) and t(3;11)(p21;q13), which were confirmed by fluorescence in situ hybridization using chromosome painting probes. Reverse transcriptase-mediated polymerase chain reaction (PCR) and Northern blot analyses demonstrated overexpression of the CCND1 gene, suggesting alteration of the BCL1-CCND1 locus. We thus performed long-distance inverse PCR using nested primers for the Calpha constant region of immunoglobulin heavy chain gene (IGH) and obtained a clone that encompassed the 11q13/IGH fusion. Nucleotide sequencing determined that the fusion occurred at the Salpha2 switch region and at the centromeric side of the major translocation cluster of BCL1. The other IGH allele consisted of a VDJ complex that was adjacent to the Cdelta constant gene, indicating that a class switch-like mechanism from the C(mu) to Cdelta was involved in the production of the Ig delta heavy chain. Point mutations within the P53 and N-RAS genes were presumably related to the rapidly progressive disease in this particular MM patient.


Assuntos
Cadeias Pesadas de Imunoglobulinas/imunologia , Mieloma Múltiplo/patologia , Idoso , Sequência de Bases , Northern Blotting , Southern Blotting , Cromossomos Humanos Par 14 , Cromossomos Humanos Par 3 , Clonagem Molecular , DNA de Neoplasias , Feminino , Genes p53 , Genes ras , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Hibridização in Situ Fluorescente , Cariotipagem , Dados de Sequência Molecular , Mieloma Múltiplo/genética , Mieloma Múltiplo/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência do Ácido Nucleico , Translocação Genética , Células Tumorais Cultivadas
17.
Cancer Chemother Pharmacol ; 24(6): 371-5, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2791191

RESUMO

The pharmacokinetics of oral N4-palmitoyl-1-beta-D-arabinofuranosylcytosine (PLAC), a lipophilic and deaminase-resistant derivative of 1-beta-D-arabinofuranosylcytosine (ara-C), were determined in patients with hematologic malignancies. The concentration of ara-C and 1-beta-D-arabinofuranosyluracil (ara-U), metabolites of PLAC, were measured by radioimmunoassay and gas chromatography-mass spectrometry-mass fragmentography, respectively. The concentration of PLAC was determined by measuring ara-C, which was derived from PLAC by hydrolyzation. In six patients given an oral bolus of PLAC (300 mg/m2), the plasma-disappearance curve of PLAC corresponded to a one-compartment open model, including first-order absorption. The peak plasma level was 22.9 +/- 6.4 ng/ml, and the predicted time to reach the peak level was 2.5 +/- 1.0 h. The elimination half-life was 3.8 +/- 2.7 h. The plasma ara-C level increased slowly to 6.9 ng/ml during the 1st 2-3 h after administration and remained over 1.0 ng/ml for 12 h. Plasma ara-U was detectable for at least 24 h, with a peak concentration of 376 ng/ml at 6 h. Urinary PLAC excretion was below the limit of detection (5 ng/ml) in all cases. Prolonged urinary ara-C and ara-U excretion was detected, but the total recovery rate was low (6.7% in 24 h) and varied between patients. In spite of the lipophilic nature of the drug, the PLAC concentration in the cerebrospinal fluid, measured at 3 or 6 h, was below the limit of detection in all four patients with no meningeal involvement. This study showed low but persistent levels of PLAC in plasma and tissues, with a continuous release of small amounts of ara-C, which demonstrated antitumor activity in patients with hematologic malignancies.


Assuntos
Antineoplásicos/farmacocinética , Citarabina/análogos & derivados , Doenças Hematológicas/tratamento farmacológico , Adulto , Idoso , Antineoplásicos/administração & dosagem , Arabinofuranosiluracila/metabolismo , Citarabina/administração & dosagem , Citarabina/metabolismo , Citarabina/farmacocinética , Feminino , Humanos , Leucemia/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Policitemia Vera/tratamento farmacológico
18.
Resuscitation ; 28(2): 97-102, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7846379

RESUMO

Since its introduction into clinical practice in 1988, the laryngeal mask airway (LMA) has fundamentally changed the airway management of patients undergoing routine anaesthesia. Currently in the UK, the LMA is used in > 50% of surgical procedures where an endotracheal tube (ETT) would formerly have been used. It seems timely to review the role of this device in resuscitation and its potential role in the pre-hospital arena.


Assuntos
Serviços Médicos de Emergência/métodos , Máscaras Laríngeas , Ressuscitação/instrumentação , Adulto , Anestesiologia/instrumentação , Criança , Parada Cardíaca/terapia , Humanos , Máscaras Laríngeas/efeitos adversos , Ressuscitação/métodos , Reino Unido
19.
Anticancer Res ; 6(4): 643-8, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3752943

RESUMO

Mycophenolic acid (MPA) was demonstrated to inhibit DNA and RNA synthesis in L1210 cells strongly; however these effects were remarkably reduced by guanine. The presence of MPA in the medium decreased the guanine nucleotide contents (GMP, GDP, GTP) of the cells, but the addition of guanine reversed this effect. We have reported previously that MPA had no inhibitory effect on hypoxanthine guanine phosphoribosyltransferase (HGPRTase) activity. Together these findings suggest that the decrease of guanine nucleotides induced by MPA is restored by GMP, which is formed from guanine by HGPRTase in the cells. It is speculated that a suppressor of HGPRTase activity, such as 6-mercaptopurine, may protect the antitumor activity of MPA by preventing the conversion of guanine to GMP.


Assuntos
Guanina/farmacologia , Ácido Micofenólico/antagonistas & inibidores , Ácidos Nucleicos/biossíntese , Animais , Feminino , Hipoxantina Fosforribosiltransferase/análise , Leucemia L1210/metabolismo , Mercaptopurina/farmacologia , Camundongos , Camundongos Endogâmicos , Ácido Micofenólico/metabolismo , Ácido Micofenólico/farmacologia
20.
Kansenshogaku Zasshi ; 67(7): 673-9, 1993 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-8360523

RESUMO

An assessment has been made regarding usefulness of measuring beta-D-glucan (beta-glucan) as fungal serodiagnosis in 50 cases of fungal infection with hematological diseases. Further, an assessment has been made regarding relation between hematological findings and therapeutic effect by administering miconazole, an antifungal agent (MCZ: Florid, clinically to the subjects. Positivity of beta-glucan (beta-glucan > or = 10 pg/ml) was observed in 54.5% (24/44), and the effective rate of MCZ in the positive cases was 75.0% (18/24). In the cases in whom fungus was detected, beta-glucan-positive rate was 50.0% (8/16), and MCZ-effective rate in beta-glucan-positive cases was 62.5% (5/8). The total effective rate of MCZ was 80% (40/50). Side effects were observed in 3 cases, but continual administration of MCZ was possible in all of the 3 cases. By the assessment regarding the relation between hematological findings and therapeutic effect of MCZ, it was found that the effective rates in the cases who underwent a transition with neutrophil and lymphocyte counts less than 500/microliters during the period of MCZ administration were 64.7% (11/17) and 50% (5/10), respectively, and large effects were observed in the cases who underwent a transition with the neutrophil and lymphocyte counts more than 500/microliters was 86.7% (19/22) and 91.7% (22/24), respectively. These results suggested that lymphocytes rather than neutrophils had an important role in the morbidity of fungal infection. It was noteworthy that MCZ was effective for the treatment of deep seated mycosis and significant effective rate was obtained in the group of patients who had neutrophils and lymphocytes less than 500/microliters.


Assuntos
Doenças Hematológicas/complicações , Miconazol/uso terapêutico , Micoses/tratamento farmacológico , beta-Glucanas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Glucanos/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Micoses/diagnóstico , Testes Sorológicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA