Assuntos
Atividade Bactericida do Sangue , Leucócitos/fisiologia , Peroxidase/fisiologia , Peroxidases/fisiologia , Cloretos/metabolismo , Escherichia coli , Humanos , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Iodo/metabolismo , NAD/metabolismo , NADP/metabolismo , FagocitoseRESUMO
Bacteria preincubated with myeloperoxidase (MPO) are more readily killed upon the addition of H2O2 and Cl- than controls not subject to prior incubation. This effect was evidenced by decreased requirements of MPO and H2O2 (to approximately 33%) for equivalent bactericidal activity. MPO adsorbed onto the bacterial surface is not accessible to other competing substrates such as guaiacol and [1(-14)C] alanine. It appears that when MPO is adsorbed to the bacteria, it carries out a coupled reaction in which the activated chlorine directly attacks the bacterial cell surface.
Assuntos
Cloretos/farmacologia , Peroxidase/farmacologia , Peroxidases/farmacologia , Peróxidos/farmacologia , Escherichia coli , Humanos , Testes de Sensibilidade Microbiana , Fatores de TempoRESUMO
In this study, we have attempted to correlate optical density measurements of amniotic fluids with L/S ratios. We may conclude, with over a 98 per cent accuracy, that fluids having optical density readings of 0.15 and above, at 650 nm. will have an L/S ratio over 2.0. Fluids having optical density readings up to 0.05 will have L/S ratios of about 1.3. Finally, amniotic fluids having optical densities greater than 0.05 and less than 0.15 will have L/S ratios of approximately 1.5.
Assuntos
Líquido Amniótico/análise , Fosfatidilcolinas/análise , Análise Espectral , Esfingomielinas/análise , Feminino , Humanos , Pulmão/embriologia , GravidezRESUMO
A simple and rapid test that correlates with L/S ratios has been developed. By centrifuging fresh, unfrozen amniotic fluids at 200g for 10 minutes and measuring the optical density at at 650 nm, correlation with L/S ratios is obtained. Optical density readings of 0.15 or greater correlate 100% with L/S ratios of 2.0 or greater. Optical readings below 0.15 correlate 94% with L/S ratios below 2.0.
Assuntos
Líquido Amniótico/análise , Fosfatidilcolinas/análise , Esfingomielinas/análise , Feminino , Humanos , Gravidez , Análise EspectralRESUMO
The influence of pregnancy, pregnancy plasma, and pregnancy-associated lhormones on the response of peripheral blood lymphocytes to two phytomitogens (PHS and PWM) was examined in a group of 17 healthy women during pregnancy and the postpartum period. No consistent disparity between pregnancy, postpartum, and control tests was noted in either intrinsic lymphocyte responsiveness or in the effect of autologous plasma or four pregnancy-associated hormones (estriol, progesterone, hPL, and estradiol-17 beta) on lymphocyte responsiveness.
Assuntos
Lectinas/farmacologia , Ativação Linfocitária , Período Pós-Parto , Gravidez , Adolescente , Adulto , Estradiol/farmacologia , Estriol/farmacologia , Feminino , Humanos , Lactogênio Placentário/farmacologia , Progesterona/farmacologiaAssuntos
Fenômenos Fisiológicos Bacterianos , Peróxido de Hidrogênio/sangue , Peróxido de Hidrogênio/metabolismo , Linfócitos/metabolismo , Neutrófilos/metabolismo , Fagocitose , Animais , Atividade Bactericida do Sangue , Membrana Celular/metabolismo , Cloretos/sangue , Humanos , Concentração de Íons de Hidrogênio , Hidrolases/sangue , Leucemia/sangue , Leucócitos/fisiologia , Linfócitos/imunologia , Linfócitos/fisiologia , Lisossomos/enzimologia , NADH NADPH Oxirredutases/metabolismo , NADP/sangue , NADP/metabolismo , Neutrófilos/enzimologia , Neutrófilos/imunologia , Oxirredução , Consumo de Oxigênio , Peroxidase/sangue , Peroxidase/metabolismo , Baço/citologiaRESUMO
A test that circumvents the complex methodology needed for the determination of L/S ratios has been developed. It has been observed that the optical density, measured at 400 nm, of supernatants collected from fresh amniotic fluids centrifuged at 2000 g for 10 minutes correlates with L/S ratios.
Assuntos
Líquido Amniótico , Fosfatidilcolinas/análise , Esfingomielinas/análise , Líquido Amniótico/análise , Centrifugação , Densitometria , Feminino , Humanos , Métodos , GravidezRESUMO
A 20,000 g pellet obtained from the homogenate of CD1 mouse spleen cells has measurable peroxidase and bactericidal activities. Whole body x-irradiation stimulates the in vitro peroxidative and bactericidal activities of the spleen cells. These cells do not phagocytize. However, addition of polystyrene latex particles to spleen cells from non- or x-irradiated mice, increases glucose oxidation. The extent of this stimulation (three- to fourfold) is less than that of PMN (six- to tenfold). Interaction between particles and lymphocyte surface may be the cause of this stimulation. The increased bactericidal activity due to x-ray is attributed mainly to an increase in the peroxidase activity of the lymphocytes. Surface (membrane) action rather than phagocytosis may be involved in the bactericidal process. The spleen lymphocyte peroxidase is distinct from myeloperoxidase in several respects.
Assuntos
Linfócitos/efeitos da radiação , Peroxidases/metabolismo , Efeitos da Radiação , Animais , Escherichia coli , Feminino , Glucose/metabolismo , Linfócitos/enzimologia , Linfócitos/fisiologia , Masculino , Camundongos , Baço/efeitos da radiação , Raios XRESUMO
1. MPO, H2O2 and C1- form a complex that undergoes intramolecular rearrangement yielding the chlorinium ion. 2. The chlorinium ion can interact with MPO, bacteria and amino acids. 3. The reaction can occur at a wide range of pH, H2O2 concentration and C1- concentration. 4. The chlorinium ion can attack different protein molecules to cause structural changes. 5. Preincubation of MPO with bacteria results in greater bactericidal activity. 6. Diffusible bactericidal agents are also produced by the MPO-H2O2-C1- system.
Assuntos
Cloretos/metabolismo , Sistema Fagocitário Mononuclear/fisiologia , Peroxidase/metabolismo , Peroxidases/metabolismo , Fagocitose , Animais , Bactérias , Proteínas de Bactérias , Cloretos/farmacologia , Descarboxilação , Escherichia coli , Peróxido de Hidrogênio/farmacologia , Concentração de Íons de Hidrogênio , CinéticaAssuntos
Linfócitos/imunologia , Macrófagos/imunologia , Neutrófilos/imunologia , Fagocitose , Animais , Bactérias , Síndrome de Chediak-Higashi/imunologia , Quimiotaxia , Proteínas do Sistema Complemento/metabolismo , Granuloma/imunologia , Kwashiorkor/imunologia , Leucemia/imunologia , Neutrófilos/metabolismo , Proteínas Opsonizantes , Peroxidases/deficiência , Peroxidases/metabolismoAssuntos
Leucemia Experimental/enzimologia , Peroxidases/antagonistas & inibidores , Baço/enzimologia , Animais , Radioisótopos de Carbono , Escherichia coli , Formiatos/metabolismo , Glucose/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Camundongos , Camundongos Endogâmicos AKR , Peroxidases/metabolismo , Peróxidos/metabolismo , Fagocitose , Baço/imunologiaRESUMO
The antimicrobial activities of the myeloperoxidase-H(2)O(2)-halide system have received considerable attention recently. The precise mechanism by which this system exerts its lethal activity is presently not clear. In an effort to learn more regarding a possible mechanism of action, the susceptibility of protein-bound amino acids to enzymatic attack by myeloperoxidase (MPO) in the presence of chloride ions was investigated. [1, 7-(14)C]diaminopimelic acid (DAP) was incorporated into Escherichia coli W-7 proteins with little randomization of the radioactivity. Under appropriate conditions, it was observed that the MPO-H(2)O(2)-halide system released approximately 94% of the radioactivity from labeled bacteria. This would indicate that, in addition to decarboxylation, peptide bonds are also split during this reaction. The oxidative decarboxylation of DAP-labeled bacteria by MPO (i) is Cl(-) dependent, (ii) has an acid pH optimum, (iii) requires a specific concentration of H(2)O(2) for activity, (iv) reaches a plateau by 25 min, and (v) is markedly inhibited by taurine. These properties are similar to those observed with free amino acids. It appears from these data that MPO can not only decarboxylate free and bound amino acids, yielding aldehydes, but also it can actively participate in oxidative peptide cleavage. Both of those activities may play a critical role in the microbicidal action of the leukocyte.
Assuntos
Proteínas de Bactérias/metabolismo , Deutério/farmacologia , Escherichia coli/metabolismo , Peroxidases/farmacologia , Ácidos Pimélicos/metabolismo , Aldeídos/metabolismo , Radioisótopos de Carbono , Cloro/farmacologia , Descarboxilação , Concentração de Íons de Hidrogênio , Leucócitos/fisiologia , Taurina/farmacologia , Fatores de TempoAssuntos
Estrogênios/farmacologia , Leucócitos/enzimologia , Peroxidases/metabolismo , Fagocitose/efeitos dos fármacos , Aminoácidos/metabolismo , Animais , Líquido Ascítico/citologia , Atividade Bactericida do Sangue , Radioisótopos de Carbono , Descarboxilação , Relação Dose-Resposta a Droga , Escherichia coli , Estradiol/farmacologia , Estriol/farmacologia , Estrona/farmacologia , Feminino , Guaiacol , Cobaias , Humanos , Concentração de Íons de Hidrogênio , Oxirredução , Gravidez , Progesterona/farmacologia , Estimulação QuímicaRESUMO
The 20,000g pellet obtained by centrifugation of a homogenate of rabbit alveolar macrophages has antibacterial activity in the presence of a hydrogen peroxide-generating system and iodide. Peroxidase activity has been demonstrated in this fraction. Addition of 3-amino-1,2,4-triazole diminished the antibacterial activity of the pellet-hydrogen peroxide-iodide system.