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1.
Laryngorhinootologie ; 93(5): 309-15, 2014 May.
Artículo en Alemán | MEDLINE | ID: mdl-24519318

RESUMEN

Keloids are fibroproliferative extreme variants of an impaired wound healing, developing a tumour-like growth. In the ENT area keloids arise mainly at auricle. Often caused by piercings or trauma. They grow bulging excessively over the original scar edges and adopt sometimes bizarre morphologies. The patients complain often of dysesthesias such as burning pain, severe itching and are suffering often from stigmatization. The huge number of therapy methods, for the treatment of keloids described in the literature (silicon therapy, compression, intralesional corticoids, intra- or extralesional surgical excision, kryosurgery, radiatio, Interferon- or Bleomycin-therapy) emphasize the enormous challenge for the treating doctor, particularly in facial plastic surgery.


Asunto(s)
Estética , Queloide/cirugía , Enfermedades Otorrinolaringológicas/cirugía , Procedimientos de Cirugía Plástica/métodos , Terapia Combinada , Conducta Cooperativa , Cara/cirugía , Humanos , Comunicación Interdisciplinaria , Enfermedades Otorrinolaringológicas/patología , Recurrencia , Factores de Riesgo , Piel/patología
2.
Laryngorhinootologie ; 92(1): 51-9; quiz 60-1, 2013 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-23264076

RESUMEN

The construction of facial prostheses is frequently used as a remedial treatment method in otorhinolaryngology. Modern prostheses are often attached to the face via bone anchored titanium implants and magnetic attachments. The use of specialised silicones and colouring techniques produces prostheses which realistically mimic lost facial tissues and significantly enhance patient quality of life. The article provides an overview of the possibilities of modern epithetics in the treatment of facial defects resulting from head and neck tumors.


Asunto(s)
Estética , Neoplasias Faciales/cirugía , Neoplasias de Oído, Nariz y Garganta/cirugía , Procedimientos de Cirugía Plástica , Complicaciones Posoperatorias/rehabilitación , Implantación de Prótesis , Oído Externo/cirugía , Neoplasias Faciales/psicología , Humanos , Magnetismo , Neoplasias de Oído, Nariz y Garganta/psicología , Complicaciones Posoperatorias/psicología , Diseño de Prótesis , Ajuste de Prótesis , Implantación de Prótesis/psicología , Calidad de Vida/psicología , Procedimientos de Cirugía Plástica/psicología , Siliconas , Anclas para Sutura
3.
J Physiol Pharmacol ; 58 Suppl 5(Pt 2): 603-14, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18204174

RESUMEN

Inhalation of heparin results in local antiinflammatory and antifibrotic effects and an inhibition of blood coagulation. A number of experimental and clinical studies demonstrated that inhalant administration of heparin or low molecular weight heparin (LMWH) is a feasible and save tool for anticoagulative treatment. However, heparin and LMWH differ in respect to their molecular weight, pulmonary absorption, and principle of their anticoagulative pattern. In our study we investigated the anticoagulative effect of different doses of the LMWH certoparin after inhalation (3000 IU-9000 IU) and subcutaneous injection (3000 IU) in healthy individuals in a cross-over design. Inhalations were performed using a new device allowing inhalations with optimized and standardized breathing patterns. The anticoagulative effect was determined by measurement of the anti-factor-Xa (anti-FXa) activity. Lung function parameters were measured before and after drug inhalation. Analysis of the anti-FXa activity as a function of the time after administration revealed values of the area under the curve (AUC) of 5.70+/-1.58 U.hour/ml and 8.43+/-1.31 U.hour/ml (mean+/-SD) with interindividual coefficients of variation of 28% and 13% after injection of 3000 IU and inhalation of 9000 IU, respectively. The AUC after inhalation of 9000 IU was significantly higher (P=0.0007) compared with subcutaneous injection of 3000 IU. In consequence, in order to obtain plasma anti-FXa activities of above 0.2 U/ml, which is considered sufficient for prophylaxis of venous thrombosis, 9000 IU LMWH have to be inhaled. Compared with the subcutaneous administration, the action of certoparin is longer after inhalation than after injection. Apparently, the drug is released rapidly according to a two-compartment kinetics, and its anticoagulant activity lasts over a long time without a marked plasma peak after administration. In detail, an elevation of plasma anti-FXa activity is achieved for 12 hours to 24 hours without a distinct peak shortly after inhalation. Inhalation of LMWH does not result in any changes in lung function or other side effects. The administration of LMWH by inhalation bears the following: the non-invasive route of drug application, the low interindividual variability of the anticoagulative effect, and a long-time pharmacological effect. These properties suggest that controlled inhalation of heparin is an attractive alternative to subcutaneous administration.


Asunto(s)
Anticoagulantes/administración & dosificación , Anticoagulantes/farmacología , Heparina de Bajo-Peso-Molecular/administración & dosificación , Heparina de Bajo-Peso-Molecular/farmacología , Administración por Inhalación , Adolescente , Adulto , Anticoagulantes/efectos adversos , Área Bajo la Curva , Coagulación Sanguínea/efectos de los fármacos , Estudios Cruzados , Interpretación Estadística de Datos , Relación Dosis-Respuesta a Droga , Factor Xa/análisis , Femenino , Heparina de Bajo-Peso-Molecular/efectos adversos , Humanos , Inyecciones Subcutáneas , Masculino , Persona de Mediana Edad , Pruebas de Función Respiratoria
5.
Stroke ; 32(1): 22-9, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11136909

RESUMEN

BACKGROUND AND PURPOSE: To study the safety and efficacy of the low-molecular-weight heparin certoparin, we performed a randomized, double-blind, dose-finding multicenter trial in patients with acute ischemic stroke (Therapy of Patients With Acute Stroke [TOPAS]). METHODS: We randomized 404 patients to 4 treatment groups within 12 hours of stroke onset: 3000 U anti-factor Xa (aXa) certoparin once daily (treatment group 1); 3000 U aXa twice daily (group 2); 5000 U aXa twice daily (group 3); and 8000 U aXa twice daily (group 4). The primary efficacy variable was the proportion of patients reaching a favorable functional outcome (Barthel Index >/=90 points) at 3 months. CT was performed at trial entry, after 7 days, and on clinical deterioration. RESULTS: The proportion of patients with Barthel Index >/=90 was not different between treatment arms (61.5%, 60.8%, 63.3%, and 56.3% in the 4 groups, respectively; intent-to-treat population). European Stroke Scale scores improved in all treatment groups within the first 14 days to a similar extent. During the follow-up of 6 months, percentages of patients with recurrent stroke/transient ischemic attack were 11.0%, 5.9%, 9.7%, and 13.0% in the 4 groups, respectively. Overall mortality was only 7.4%. Two parenchymal cerebral hematomas and 1 extracranial bleeding episode occurred in treatment group 1 versus 1 and 0 in group 2, 2 and 0 in group 3, and 4 and 5 in group 4, respectively. During certoparin treatment, 1 deep vein thrombosis but no pulmonary embolism was observed. CONCLUSIONS: Dose increase of certoparin up to 8000 U aXa twice daily did not improve the functional outcome of patients with ischemic stroke. Severe bleeding tended to be more frequent in the highest dose group only.


Asunto(s)
Anticoagulantes/administración & dosificación , Isquemia Encefálica/tratamiento farmacológico , Heparina de Bajo-Peso-Molecular/administración & dosificación , Accidente Cerebrovascular/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticoagulantes/efectos adversos , Isquemia Encefálica/complicaciones , Isquemia Encefálica/diagnóstico por imagen , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Esquema de Medicación , Inhibidores del Factor Xa , Femenino , Estudios de Seguimiento , Alemania , Hemorragia/etiología , Heparina de Bajo-Peso-Molecular/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Recurrencia , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico por imagen , Tasa de Supervivencia , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
6.
Inflammation ; 25(5): 331-7, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11820460

RESUMEN

We analyzed the influence of heparins (unfractionated heparin, UFH and low molecular weight heparin certoparin) on the generation of IL-1ra, IL-6, IL-10, and IL-12p40 and from leukocyte fractions in vitro. Polymorphonuclear neutrophil leukocytes (PMN) and peripheral blood mononuclear cells (PBMC) from 16 different healthy donors were isolated and adjusted to 1 x 10(6) cells/ml supplemented RPMI 1640. Leukocyte fractions were differentially stimulated (PMN with 1 microg and 5 microg LPS, PBMC with 10 ng TSST- 1 or 2 microg ConA) in the presence or absence of heparins (1 U/ml, 2 U/ml, and 4 U/ml) for 24 h at 37 degrees C. Cytokine release was analyzed by ELISA. Certoparin but not UFH led to a dose-dependent increase in IL-6 from non-stimulated PBMC. In contrast, the release of IL-1ra, IL-10, and IL-12p40 was not modulated by heparins in a dose-dependent fashion. Increases in these cytokines occurred only as single incidents at intermediate heparin levels. An influence of the heparins on the apoptosis of PMN (measured as DNA-fragmentation in non-stimulated or LPS-stimulated cell-fractions) was not observed.


Asunto(s)
Citocinas/efectos de los fármacos , Fibrinolíticos/farmacología , Heparina de Bajo-Peso-Molecular/farmacología , Heparina/farmacología , Leucocitos/efectos de los fármacos , Citocinas/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Mediadores de Inflamación/metabolismo , Leucocitos/metabolismo , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , Neutrófilos/efectos de los fármacos , Neutrófilos/metabolismo
7.
Int J Cardiol ; 73(2): 165-71, 2000 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-10817856

RESUMEN

We investigated a possible correlation between the serologic status concerning Cytomegalovirus (CMV), Chlamydia pneumoniae (CP) and Helicobacter pylori (HP) and the occurrence of restenosis in patients undergoing percutaneous transluminal coronary angioplasty for symptomatic coronary artery disease. Tests for anti-CMV IgG, anti-Chlamydia pneumoniae IgG and IgA and HP IgG and IgA were performed with an enzyme-linked immunosorbent assay (ELISA). Restenosis was defined as >/=50% stenosis at follow-up angiography in a vessel with less than 50% stenosis immediately after PTCA. Of 148 patients, 112 (75.7%) were seropositive for CMV, 75 (50.7%) were seropositive for CP and 78 (52.7%) were seropositive for HP. Restenosis occured in 31.8% of patients. CMV seropositivity was established in 74.5% of patients with restenosis versus 76.2% without restenosis (P=0.82), CP seropositivity was established in 44. 7% of patients with restenosis versus 53.5% without restenosis (P=0. 32), HP seropositivity was established in 53.2% of patients with restenosis versus 52.5% without restenosis (P=0.94). In contrast to some earlier studies CMV or HP seropositivity could not be found to be associated with the risk of restenosis after coronary intervention. An association between the serological status of CP and restenosis could also not be established.


Asunto(s)
Angioplastia Coronaria con Balón , Infecciones por Chlamydia/complicaciones , Enfermedad de la Arteria Coronaria/microbiología , Enfermedad de la Arteria Coronaria/terapia , Infecciones por Citomegalovirus/complicaciones , Infecciones por Helicobacter/complicaciones , Infecciones por Chlamydia/diagnóstico , Chlamydophila pneumoniae/aislamiento & purificación , Constricción Patológica/diagnóstico , Constricción Patológica/etiología , Angiografía Coronaria , Vasos Coronarios/microbiología , Vasos Coronarios/virología , Infecciones por Citomegalovirus/diagnóstico , Femenino , Estudios de Seguimiento , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Recurrencia , Medición de Riesgo , Factores de Riesgo , Pruebas Serológicas
8.
Circulation ; 96(5): 1482-7, 1997 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-9315535

RESUMEN

BACKGROUND: The VERAS study (VErringerung der Restenoserate nach Angioplastie durch ein Somatostatin-analogon [Prevention of Restenosis Following Angioplasty With a Somatostatin Analogue]) was a placebo-controlled trial to evaluate the effects of octreotide for the prevention of restenosis after coronary angioplasty. Octreotide is a somatostatin analogue with antiproliferative properties on smooth muscle cell growth in vitro that limits myointimal thickening of arteries in balloon injury models. METHODS AND RESULTS: Patients received either octreotide or placebo, starting 1 hour before angioplasty and continued for 3 weeks. The minimal luminal diameters before and after angioplasty and at 6-month follow-up were analyzed with a digital quantitative algorithm. Of the initial 274 patients recruited, 217 (108 in the octreotide group and 109 in the placebo group) could be analyzed after a complete 6-month evaluation: the minimal luminal diameters were 1.67+/-0.57 mm in the octreotide-treated group and 1.66+/-0.64 mm in the placebo group (two-paired P=.70), and the relative losses were 0.16+/-0.22 and 0.13+/-0.21 (two-paired P=.27). The restenosis rates were also identical in both treatment groups: final diameter stenosis > or =50% (34.3% versus 33.9%, two-paired P=1.0), loss of > or =50% of the initial gain (34.3% versus 33.9%, two-paired P=1.0), and absolute reduction of minimal luminal diameter >0.72 mm (29.6% versus 24.8%, two-paired P=.45). Likewise, there was no difference with regard to the incidence of clinical events (death, myocardial infarction, bypass operations, reintervention). Octreotide was well tolerated, with the exception of gastrointestinal side effects, which were three times more common than in the placebo group. CONCLUSIONS: Octreotide did not reduce the angiographically determined restenosis rate or the incidence of major clinical events after coronary angioplasty.


Asunto(s)
Angioplastia Coronaria con Balón , Enfermedad Coronaria/prevención & control , Enfermedad Coronaria/terapia , Hormonas/uso terapéutico , Octreótido/uso terapéutico , Adulto , Anciano , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Recurrencia , Insuficiencia del Tratamiento
10.
Burns ; 21(6): 427-31, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8554683

RESUMEN

The integrin CD11b is an important adhesion molecule mediating the transendothelial migration of circulating polymorphonuclear granulocytes into an inflammatory region. The expression of CD11b is closely related to the ability to polymerize actin, a major component of the cytoskeleton within the phagocyte. In this study we compared the CD11b expression as well as the polymerization of actin of isolated neutrophils from patients endangered by sepsis with cells from healthy donors. The patient population was subdivided into a group of patients with severe thermal injuries and a group of patients who were admitted to an intensive care unit on suspicion of sepsis. The following results were obtained: (1) cells from burn patients, but not from non-burn patients, showed a reduced basal expression of CD11b during the first week after the burn trauma; (2) stimulation with the chemotactic peptide formyl-Met-Leu-Phe (FMLP) led to a strong overexpression of CD11b on the cells from the burn patients, this effect was not observed using cells of the second subgroup; (3) the content of polymerized actin was reduced within resting and stimulated cells from burn patients during the first 2 weeks postinjury, non-burn patient cells showed an enhanced F-actin content within the first week; (4) the ability of burn and non-burn patient cells to polymerize actin after stimulation with FMLP was slightly impaired during the first week post injury/admission. The results demonstrate that cells from patients endangered by sepsis show dysfunctions on the level of adhesion molecule expression and the strongly related actin polymerization.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Actinas/metabolismo , Quemaduras/metabolismo , Antígeno de Macrófago-1/metabolismo , Neutrófilos/metabolismo , Sepsis/metabolismo , Adulto , Anciano , Quemaduras/complicaciones , Quemaduras/patología , Femenino , Citometría de Flujo , Humanos , Masculino , Persona de Mediana Edad , Sepsis/etiología , Sepsis/patología
11.
J Leukoc Biol ; 53(3): 268-72, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8454951

RESUMEN

In order to study the biochemical mechanism underlying the cellular dysfunctions of polymorphonuclear granulocytes (PMNs) from severely burned patients, we analyzed the role of GTP-binding proteins (G-proteins) in PMNs from 11 burned patients. Our data demonstrate a significant enhancement of the basal GTPase activity within unstimulated neutrophils of severely burned patients compared to cells from healthy donors. This enhancement was significant within 4 weeks after the trauma, followed by a return to control levels. The increase in GTPase activity correlated with enhanced expression of the small G-protein Ras and the regulatory Ras-GTPase activating protein (Ras-GAP) compared to that in healthy donor cells. However, expression of the Ras-related protein Rap1, which is involved in initiation of the respiratory burst, was reduced. The observed changes in G-protein activity and expression impair the signal transduction cascade as well as bacterial killing and may lead to high susceptibility toward infections and finally to septic conditions.


Asunto(s)
Quemaduras/sangre , Proteínas de Unión al GTP/análisis , Neutrófilos/química , Adulto , Autorradiografía , Quemaduras/patología , Femenino , GTP Fosfohidrolasas/sangre , Proteínas Activadoras de GTPasa , Humanos , Immunoblotting , Masculino , Microsomas/enzimología , Persona de Mediana Edad , Neutrófilos/fisiología , Proteínas/análisis , Proteínas Activadoras de ras GTPasa
13.
Immunology ; 75(2): 281-5, 1992 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1312995

RESUMEN

The effect of various cytokines [interleukin-3(IL-3), IL-6, IL-8, tumour necrosis factor-beta (TNF-beta)] on human neutrophils (PMN) was analysed with regard to the generation of leukotrienes and the involvement of guanosine triphosphate (GTP)-binding proteins (G proteins). Incubation of cytochalasin B-pretreated PMN with cytokines alone did not lead to a generation of leukotrienes. However, the cytokines affected the formyl-methionyl-leucyl-phenylalanine-(FMLP)-induced formation of leukotrienes in a time-dependent manner. Preincubation of the cells with the different cytokines for short periods (15 seconds at 37 degrees) enhanced the subsequent FMLP-induced leukotriene generation, whereas preincubation for prolonged times resulted in a reduced formation of leukotrienes. These results correlated with the respective G protein-associated guanosine triphosphatase (GTPase) activities within isolated membrane fractions. The present study indicates a modulation of the FMLP-induced leukotriene formation by diverse cytokines via interaction with the GTP-binding proteins.


Asunto(s)
Interleucinas/inmunología , Linfotoxina-alfa/inmunología , Neutrófilos/inmunología , Células Cultivadas , Relación Dosis-Respuesta Inmunológica , GTP Fosfohidrolasas/sangre , Humanos , Interleucina-3/inmunología , Interleucina-6/inmunología , Interleucina-8/inmunología , Leucotrieno B4/biosíntesis , N-Formilmetionina Leucil-Fenilalanina/inmunología , Neutrófilos/enzimología
14.
Immunology ; 75(1): 150-6, 1992 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1537591

RESUMEN

The effects of neomycin on human neutrophils (PMN) were studied with respect to the generation of leukotrienes, the involvement of guanine triphosphate binding proteins (G proteins) and the polymerization of actin. Incubation of neutrophils with neomycin induced the generation of low amounts of leukotrienes. Co-incubation of neutrophils with neomycin and the direct G-protein activator sodium fluoride (NaF) resulted in an enhanced leukotriene formation at 0.5 mM neomycin and an inhibition at a concentration of 10 mM. Simultaneous incubation with neomycin and formyl-methionyl-leucyl-phenylalanine (FLMP) did not affect the FMLP-induced leukotriene formation. However, pretreatment of neutrophils with 10 mM neomycin followed by the addition of NaF or FMLP resulted in an enhanced generation of leukotrienes. Crude membrane fractions of PMN incubated with neomycin at different concentrations showed an enhanced (0.5 mM) as well as a reduced (10 mM) guanine triphosphatase activity. Furthermore, incubation of neutrophils with neomycin above a concentration of 0.5 mM led to the depolymerization of actin. The presented results show inhibitory and stimulatory effects of neomycin on various cell functions, which may reflect differences in transmembrane signalling.


Asunto(s)
Actinas/sangre , GTP Fosfohidrolasas/sangre , Leucotrienos/biosíntesis , Neomicina/farmacología , Neutrófilos/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Humanos , Inositol 1,4,5-Trifosfato/biosíntesis , Sustancias Macromoleculares
15.
Eicosanoids ; 5 Suppl: S39-41, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1449828

RESUMEN

Priming of human polymorphonuclear granulocytes (PMNs) with cytokines (IL-3, IL-6, TNF-alpha) followed by a subsequent stimulation (FMLP) led to an enhanced polymerization of actin and GTPase-activity which correlated to a loss of ras immunoreactivity and an increased expression of Rab proteins. Furthermore TNF-alpha and 12-HETE induced the heat shock proteins (hsp 70 family) in PMNs as was demonstrated by metabolic radiolabeling and Western blotting (anti-hsp 72). This activation of the stress response exerted a protective function towards a subsequent lytic attack by a bacterial cytolysin (leukocidin).


Asunto(s)
Citocinas/farmacología , Eicosanoides/farmacología , Proteínas de Choque Térmico/biosíntesis , Neutrófilos/metabolismo , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico , Actinas/metabolismo , Western Blotting , GTP Fosfohidrolasas/metabolismo , Humanos , Ácidos Hidroxieicosatetraenoicos/farmacología , Interleucina-3/farmacología , Interleucina-6/farmacología , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacología
16.
Int Arch Allergy Immunol ; 99(2-4): 387-389, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-34167248

RESUMEN

Preincubation of human polymorphonuclear neutrophils (PMN) with diverse cytokines for 15 s enhanced the subsequent formyl-Met-Leu-Phe (FMLP)- induced leukotriene (LT) generation. These results correlated with a significant enhanced GTPase activity and an additive actin polymerization. Preincubation with genistein, an inhibitor of tyrosine kinases, inhibited LT formation as well as GTPase activities. Incubation with IL-3 or 11-3 and FMLP led to a shift in [35S]-γ-GTP binding to microsomal proteins as compared to unstimulated or FMLP-stimulated PMN. These results suggest a fundamental role of low molecular weight GTP-binding proteins and tyrosine kinases for cellular activation.

17.
Int Arch Allergy Immunol ; 99(2-4): 397-399, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-34167270

RESUMEN

The involvement of low molecular weight G proteins (LMWG) was determined during cell-cell interaction between human neutrophils and platelets. α-[32P]-GTP binding revealed an enhanced expression of an 18-kD band and a diminished band at 21 kD derived from platelets after coincubation of both cell types. Coincubation of the cells did not show any effect on the expression of rap2, whereas rapl was enhanced. The subadditive GTPase activity after coincubation of PMN and platelets could be due to some extent to the diminished expression of the ras protein. The presented data suggest an important role of the LMWG during cell-cell interaction between PMN and platelets.

18.
Immunology ; 74(2): 271-8, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1660854

RESUMEN

Incubation of neutrophils with interferon-alpha (IFN-alpha) for 5 min and subsequent stimulation with the calcium ionophore A23187 enhanced the production of oxygen radicals, while a suppression was obtained with FMLP-stimulated cells. Similar data were observed for the direct G-protein activator sodium fluoride (NaF). Incubation of the cells with IFN-alpha and subsequent stimulation with FMLP (in the presence of cytochalasin b) reduced the generation of the chemotactic active leukotriene B4 (LTB4). The metabolism of LTB4 was significantly inhibited. IFN-alpha decreased the specific binding sites for LTB4 and increased the number of binding sites for FMLP. The GTPase activity as a parameter for the activation of G-proteins was enhanced by IFN-alpha. Preincubation of the cells with IFN-alpha and subsequent stimulation with NaF increased the GTPase activity synergistically, whereas co-incubation of IFN-alpha with FMLP showed additive effects. Our results clearly demonstrate the modulatory effects of IFN-alpha on granulocyte functions with regard to the receptor-mediated signal transduction.


Asunto(s)
Interferón-alfa/inmunología , Neutrófilos/inmunología , Células Cultivadas , GTP Fosfohidrolasas/sangre , Proteínas de Unión al GTP/metabolismo , Humanos , Leucotrieno B4/sangre , Neutrófilos/metabolismo , Receptores de Formil Péptido , Receptores Inmunológicos/análisis , Receptores de Leucotrieno B4
19.
Immunology ; 73(3): 287-92, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1652553

RESUMEN

Human polymorphonuclear granulocytes (PMN) and platelets were pre-activated with a receptor-mediated stimulus [formyl-methionyl-leucyl-phenylalanine (FMLP) or thrombin, respectively] and subsequently incubated with sodium fluoride (NaF). We investigated various cell responses, such as chemiluminescence by PMN, platelet aggregation and the release of lipid mediators [i.e. leukotriene B4 (LTB4) and its omega-oxidation products from neutrophils and 12-hydroxy-eicosatetraenoic acid (12-HETE) from platelets]. As a marker of G protein involvement, the binding of [3H]guanylylimidodiphosphate (Gpp (NH) p) to the membrane fractions of stimulated cells was determined. PMN pre-stimulated with FMLP showed a synergistically enhanced generation of leukotrienes returning to control values with the time of preincubation. Platelets preliminary treated with thrombin followed by incubation with NaF resulted in a sub-additive and time-independent mediator generation. Neither chemiluminescence by PMN nor platelet aggregation showed a similar pattern compared to the mediator release: PMN preincubated with FMLP followed by NaF resulted in a second chemiluminescence response; the aggregation of platelets which were preincubated with thrombin was partially inhibited by the addition of NaF. Membrane fractions isolated from FMLP-pre-stimulated neutrophils showed a pattern in [3H]Gpp (NH) p-binding capacity that was comparable to the respective leukotriene release. With thrombin-prestimulated platelets, no similarities between Gpp (NH) p binding, aggregation or 12-HETE generation were observed. The sequential activation of different cell populations using the same kind of stimulation lead to different cell responses, indicating the diversity of G proteins and their control mechanisms.


Asunto(s)
Plaquetas/metabolismo , Proteínas de Unión al GTP/sangre , Neutrófilos/metabolismo , Fluoruro de Sodio/farmacología , Plaquetas/efectos de los fármacos , Células Cultivadas , Humanos , Leucotrieno B4/sangre , Mediciones Luminiscentes , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/farmacología
20.
Int Arch Allergy Appl Immunol ; 94(1-4): 64-7, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1937907

RESUMEN

Simultaneous stimulation of human neutrophils (PMN) with the receptor-mediated activator formyl-met-leu-phe (FMLP) and the G protein activator sodium fluoride (NaF) resulted in the synergistic generation of leukotrienes. Activation of human platelets with thrombin and NaF showed an additive formation of 12-HETE. This enhancement in lipid mediator generation correlated with a time-dependent synergism in G protein activation after sequential stimulation of intact cells with FMLP and NaF or thrombin and NaF, respectively. In addition, polymerization of actin, an early event in cell activation, was enhanced after incubation with cytokines and FMLP.


Asunto(s)
Ácidos Hidroxieicosatetraenoicos/biosíntesis , Leucotrienos/biosíntesis , Neutrófilos/metabolismo , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico , Células Cultivadas , Proteínas de Unión al GTP/fisiología , Guanilil Imidodifosfato/metabolismo , Humanos , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/efectos de los fármacos , Fluoruro de Sodio/farmacología , Trombina/farmacología
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