RESUMEN
Superoxide anion is produced in human platelets predominantly by Nox2-dependent NADPH oxidases. In vitro experiments have shown that it might play a role in modulating platelet functions. The relationship between platelet superoxide production and aggregation remains poorly defined. Accordingly, we aimed to study superoxide production and aggregation in platelets from subjects with significant cardiovascular risk factors (hypertension, hypercholesterolemia, smoking and diabetes mellitus) and from control individuals. Moreover, we studied the effects of novel polyphenol-rich extracts of Aronia melanocarpa (chokeberry) berries on platelet function in vitro. Superoxide production was significantly increased in patients with cardiovascular risk profile when compared to controls, while platelet aggregation in response to either collagen or thrombin were borderline higher, and did not reach statistical significance. Interestingly, no relationship was observed between platelet aggregation ex vivo and platelet superoxide production in either of studied groups. No correlation was found between endothelial function (measured by FMD) and platelet aggregation ex vivo either. Polyphenol-rich extracts of A. melanocarpa berries caused a significant concentration dependent decrease in superoxide production only in patients with cardiovascular risk factors, while no effect was observed in the control group. A. melanocarpa extracts abolished the difference in superoxide production between risk factor patients and controls. A. melanocarpa extracts exerted significant concentration dependent anti-aggregatory effects in both studied groups, which indicated that these effects may be independent of it's ability to modulate superoxide production. The anti-aggregatory effects of chokeberry extracts were similar irrespective of aggregation inducing agent (collagen or thrombin). Moreover, they appear to be independent of platelet NO release as NOS inhibition by L-NAME did not lead to their abrogation.
Asunto(s)
Antioxidantes/farmacología , Aterosclerosis/sangre , Plaquetas/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Photinia/química , Agregación Plaquetaria/efectos de los fármacos , Superóxidos/metabolismo , Antioxidantes/aislamiento & purificación , Aterosclerosis/metabolismo , Plaquetas/metabolismo , Humanos , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacologíaRESUMEN
BACKGROUND: Staphylococcus aureus has important implications for the pathogenesis of atopic dermatitis (AD). In some patients S. aureus can be eradicated from the skin during anti-inflammatory treatment, while in others bacterial colonization is persistent. Potential mechanisms and features of these two distinct groups of patients are not known. OBJECTIVE: Accordingly, we studied relationships between the ability to eliminate S. aureus during an anti-inflammatory treatment and selected clinical and immunological features. METHODS: Quantitative assessment of S. aureus on the skin, in nasal vestibule and throat, serum IgE levels, CD4/CD8 T-cell ratio, lymphocyte proliferation and phagocyte oxidative burst were determined during the exacerbation and after 4 and 12 weeks of the treatment using topical steroid and oral antihistamine in 34 patients with AD. RESULTS: S. aureus was found on the skin of all 34 patients during exacerbation. Disease severity scoring of atopic dermatitis (SCORAD) correlated with the density of bacteria. Treatment with oral antihistamine and topical steroid resulted in a significant alleviation of symptoms, which correlated with the elimination of S. aureus from the skin in 70% of patients. In the remaining 30% of patients, dense (more than 10(10)/cm2) S. aureus skin colonization, persisted despite the treatment. Patients with persistent S. aureus presented with higher serum IgE levels, lower lymphocyte proliferation in response to staphylococcal enterotoxin B, phytohaemagluttinin and anti-CD3. Persistence of S. aureus was more common in men. CONCLUSIONS: Patients with AD differ in the ability to clear S. aureus from the skin during anti-inflammatory treatment, which appears to be related to the abnormalities in immunological parameters. Local antibiotic therapy should be considered only in patients with persistent S. aureus colonization.
Asunto(s)
Dermatitis Atópica/inmunología , Infecciones Cutáneas Estafilocócicas/inmunología , Administración Tópica , Adulto , Antialérgicos/administración & dosificación , Antialérgicos/inmunología , Relación CD4-CD8/métodos , Cetirizina/administración & dosificación , Cetirizina/inmunología , Dermatitis Atópica/complicaciones , Dermatitis Atópica/microbiología , Femenino , Antagonistas de los Receptores Histamínicos H1 no Sedantes/administración & dosificación , Antagonistas de los Receptores Histamínicos H1 no Sedantes/inmunología , Humanos , Inmunoglobulina E/análisis , Masculino , Furoato de Mometasona , Nariz/microbiología , Faringe/microbiología , Pregnadienodioles/administración & dosificación , Pregnadienodioles/inmunología , Piel/microbiología , Infecciones Cutáneas Estafilocócicas/complicaciones , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/aislamiento & purificaciónRESUMEN
Using automatic erythrocyte aggregometer type MA-1 (Myrenne gmbh, Germany), we investigated the hypothesis that therapeutic effectiveness of quinapril--angiotensin converting enzyme inhibitor (ACEI)--in the treatment of hypertension would correlate with improvement of red blood cell (RBC) aggregability. Experiments were performed on commercially available inbred strain of spontaneously hypertensive male rats (SHR) aged 19-21 weeks. Age-matched normotensive Wistar-Kyoto (WKY) rats genetically related to SHR were used as a control. Aggregability of RBC in hypertensive rats was significantly higher than in control WKY animals. Quinapril (100 microg/kg) administered i.p. for 8 days improved RBC aggregability in normotensive rats but surprisingly not in SHR animals. Beneficial effect of quinapril on RBC aggregation observed in normotensive animals did not occur when this drug was injected in combination with aspirin (1 or 50 mg/kg) or with indomethacin (20 mg/kg) or with L-NAME (10 mg/kg). However, much the same damaging effects on RBC aggregability were observed when aspirin, indomethacin or L-NAME were each administered into normotensive animals without quinapril. In contrast with normotensive rats, aggregability of RBC in SHR was not affected either by quinapril or by indomethacin and by L-NAME, given separately or in combination. The only compound significantly worsening RBC aggregability in SHR was aspirin but this effect was not dose-dependent. Quinapril-induced improvement of RBC aggregability in normotensive rats (but not in SHR) was completely abolished by simultaneous administration of B2 receptor antagonist icatibant and successfully mimicked by 8 days of treatment with bradykinin. In vitro aggregability of RBC isolated from WKY was not affected by previous incubation (30 min at 37 degrees C) with quinapril, indomethacin or L-NAME. Only aspirin (3 mM) significantly increased RBC aggregability as compared to placebo. It is concluded that under physiological conditions quinapril efficiently inhibits RBC aggregability and this effect is modulated by secretion of endothelial mediators, mainly prostacyclin and nitric oxide. In hypertension quinapril, in spite of lowering of arterial blood pressure, is unable to display its beneficial effects on RBC aggregability possibly due to the hypertension-induced/accompanied dysfunction of vascular endothelium. Aspirin revealed unique erythrocyte damaging properties, presumably independent of inhibition of cyclooxygenase but related to a direct membrane protein acetylation.
Asunto(s)
Bradiquinina/análogos & derivados , Modelos Animales de Enfermedad , Endotelio Vascular/metabolismo , Endotelio Vascular/patología , Agregación Eritrocitaria/efectos de los fármacos , Hipertensión/complicaciones , Tetrahidroisoquinolinas/antagonistas & inhibidores , Tetrahidroisoquinolinas/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Inhibidores de la Enzima Convertidora de Angiotensina/farmacocinética , Animales , Aspirina/efectos adversos , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/genética , Bradiquinina/farmacología , Quimioterapia Combinada , Epoprostenol/biosíntesis , Epoprostenol/metabolismo , Hipertensión/sangre , Hipertensión/tratamiento farmacológico , Indometacina/efectos adversos , Inyecciones Intraperitoneales , Masculino , NG-Nitroarginina Metil Éster/efectos adversos , Óxido Nítrico/biosíntesis , Óxido Nítrico/metabolismo , Quinapril , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Tetrahidroisoquinolinas/administración & dosificaciónRESUMEN
Nitric oxide (NO) and reactive oxygen species exert multiple modulating effects on inflammation and play a key role in the regulation of immune responses. They affect virtually every step of the development of inflammation. Low concentrations of nitric oxide produced by constitutive and neuronal nitric oxide synthases inhibit adhesion molecule expression, cytokine and chemokine synthesis and leukocyte adhesion and transmigration. Large amounts of NO, generated primarily by iNOS can be toxic and pro-inflammatory. Actions of nitric oxide are however not dependent primarily on the enzymatic source, but rather on the cellular context, NO concentration (dependent on the distance from NO source) and initial priming of immune cells. These observations may explain difficulties in determining the exact role of NO in Th1 and Th2 lymphocyte balance in normal immune responses and in allergic disease. Similarly superoxide anion produced by NAD(P)H oxidases present in all cell types participating in inflammation (leukocytes, endothelial and other vascular cells etc) may lead to toxic effects, when produced at high levels during oxidative burst, but may also modulate inflammation in a far more discrete way, when continuously produced at low levels by NOXs (non-phagocytic oxidases). The effects of both nitric oxide and superoxide in immune regulation are exerted through multiple mechanisms, which include interaction with cell signalling systems like cGMP, cAMP, G-protein, JAK/STAT or MAPK dependent signal transduction pathways. They may also lead to modification of transcription factors activity and in this way modulate the expression of multiple other mediators of inflammation. Moreover genetic polymorphisms exist within genes encoding enzymes producing both NO and superoxide. The potential role of these polymorphisms in inflammation and susceptibility to infection is discussed. Along with studies showing increasing role of NO and free radicals in mediating inflammatory responses drugs which interfere with these systems are being introduced in the treatment of inflammation. These include statins, angiotensin receptor blockers, NAD(P)H oxidase inhibitors, NO-aspirin and others. In conclusion in this mini-review we discuss the mechanisms of nitric oxide and superoxide dependent modulation of inflammatory reactions in experimental animals and humans. We also discuss potential roles of nitric oxide as a mediator of allergic inflammation.
Asunto(s)
Inflamación/inmunología , Óxido Nítrico/inmunología , Superóxidos/inmunología , Animales , Humanos , Inflamación/etiología , Inflamación/fisiopatología , Mediadores de Inflamación/inmunología , Modelos Biológicos , Óxido Nítrico/efectos adversos , Óxido Nítrico/metabolismo , Transducción de Señal/fisiología , Superóxidos/efectos adversos , Superóxidos/metabolismoRESUMEN
BACKGROUND: Leukotrienes are potent mediators of allergic inflammation and their role in the pathogenesis of allergic disorders, particularly asthma, is well established. Their importance in the pathogenesis of atopic eczema/dermatitis syndrome (AEDS) is still unclear. We aimed to compare urinary cysteinyl leukotriene (Cys-LT) levels during exacerbation and remission of AEDS in relation to clinical status, IgE levels, and eosinophil counts. METHODS: Urinary Cys-LTs were measured by direct enzyme immunoassay in 17 adult patients with AEDS and in 17 healthy controls in whom atopy had been excluded. Cys-LTs were compared during exacerbation and remission of AEDS in relation to the clinical status measured by SCORAD. Total IgE levels were measured by enzyme-linked immunoassay (ELISA). RESULTS: Mean clinical score during the exacerbation was 64.3 +/- 3.1 and during remission 22.4 +/- 4 (P < 0.01). Cys-LTs levels were significantly higher during the exacerbation of AEDS than in the control group (230.9 +/- 20.8 vs 123.2 +/- 9.9 pg/mg creatinine; P < 0.005). During the remission, the difference between AEDS patients and the control group was not significant (96.3 +/- 8.7 vs 123.2 +/- 9.9 pg/mg creatinine; P = 0.8). During AEDS exacerbation Cys-LTs levels were significantly correlated with the clinical status (rS = 0.73, P < 0.01) and with eosinophil counts (r = 0.86; P < 0.01) but not with the duration of the disease, age of patients, or IgE levels. CONCLUSIONS: Our results point to enhanced biosynthesis of Cys-LTs during the AEDS exacerbations. Inflammatory cells, e.g. eosinophils are the most probable source of Cys-LTs. A strong correlation between Cys-LT levels and clinical status may in part explain preliminary clinical observations of efficacy of leukotriene antagonists in alleviating symptoms of AEDS.
Asunto(s)
Cisteína/orina , Dermatitis/orina , Eccema/orina , Hipersensibilidad/orina , Leucotrienos/orina , Adolescente , Adulto , Dermatitis/fisiopatología , Eccema/fisiopatología , Eosinófilos/patología , Femenino , Humanos , Hipersensibilidad/fisiopatología , Inmunoglobulina E/análisis , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Inducción de Remisión , Índice de Severidad de la Enfermedad , SíndromeRESUMEN
Many diseases of the heart and circulatory system have been linked with both dysfunction of vascular endothelium and insufficient deformability of erythrocytes. Using shear stress laser diffractometry we investigated whether deformability of erythrocytes would be regulated endogenously by generation of two endothelial secretogogues: prostacyclin and nitric oxide. Experiments were performed in rats ex vivo and with whole blood or isolated erythrocytes in vitro. Iloprost--a stable analogue of prostacyclin (10 microg/kg i.v.) and SIN-1 (NO-donor) at a dose of 2 mg/kg/min i.v induced a significant improvement of deformability of erythrocytes ex vivo. Improvements of deformability by these two compounds were also evident in vitro when they were applied at a range of concentrations of 1 microM and 3 microM, respectively. Cyclooxygenase (indomethacin 20 mg.kg i.v.) and nitric oxide synthase (L-NAME 10 mg/kg i.v.) inhibitors while worsening deformability ex vivo, they did not affect (3 mM and 10 microM, respectively) rheological functions of erythrocytes in vitro. Aggravating effects of these inhibitors on erythrocyte deformability ex vivo were reversed by prostacyclin and nitric oxide supplemented exogenously. Aspirin at a low (1 mg/kg i.v.) and high dose (50 mg/kg i.v.), contrary to indomethacin and L-NAME, aggravated erythrocyte deformability either ex vivo or in vitro. It is concluded that autocrine function of vascular endothelium plays an important role in regulation of rheology of red blood cells in flowing blood. The mechanism of this phenomenon is unclear but some possible explanations are discussed. In addition, in our experiments aspirin revealed unique erythrocyte damaging properties, possibly independent of inhibition of cyclooxygenase, but related to a direct protein acetylation.
Asunto(s)
Endotelio Vascular/metabolismo , Epoprostenol/metabolismo , Deformación Eritrocítica/fisiología , Molsidomina/análogos & derivados , Óxido Nítrico/metabolismo , Animales , Inhibidores Enzimáticos/farmacología , Epoprostenol/farmacología , Deformación Eritrocítica/efectos de los fármacos , Iloprost/farmacología , Masculino , Molsidomina/farmacología , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Ratas , Ratas WistarRESUMEN
UNLABELLED: Despite the great progress, our understanding of the pathogenesis of atopic dermatitis (AD) is still incomplete. In particular, the clinical importance of various changes of the immune system parameters is unclear. Accordingly we have undertaken the study to compare selected parameters of cellular and humoral immunity between AD subjects (n = 26) and healthy controls (n = 10). These parameters included immunoglobulin levels (IgE in particular), neutrophil respiratory, oxygen burst, peripheral blood lymphocyte phenotype and response to mitogens. We also analysed the relationship between these parameters and clinical severity of skin lesions. RESULTS: Mean total immunoglobulin E levels were very significantly increased in the AD group (1563 +/- 459 vs 35.5 +/- 12.1 IU/ml; p = 0.001). Simultaneously total serum IgE levels varied extensively between individual subjects with AD and were significantly correlated to clinical severity of the disease (Rs = 0.44; p = 0.02). Atopic dermatitis was also associated with the increase in the number of CD4+ and simultaneous decrease in the CD8+ lymphocytes causing statistically significant difference in CD4:CD8 ratio compared to the control group. We also observed changes of proliferation indices to phytohaemagglutinin (decrease) and increase of responses to anti CD3 mAb (OKT-3) and staphylococcal enterotoxin B. None of these immune parameters however, appeared to be statistically correlated to clinical status. CONCLUSIONS: We find that atopic dermatitis is associated with significant changes of several important indices of cellular and humoral immunity including increased IgE levels and altered peripheral lymphocyte proliferation capacity and phenotype. Change of total IgE levels appears to be the most important from clinical point of view.
Asunto(s)
Antígenos CD/sangre , Dermatitis Atópica/inmunología , Inmunoglobulina E/sangre , Neutrófilos/metabolismo , Biomarcadores/sangre , Relación CD4-CD8 , Estudios de Casos y Controles , Enterotoxinas/farmacología , Humanos , Inmunosupresores , Linfocitos/metabolismo , Mitógenos/farmacología , Muromonab-CD3/farmacología , Consumo de Oxígeno , Fenotipo , Fitohemaglutininas/farmacología , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas , Superantígenos/farmacologíaRESUMEN
Inflammation is a major process in the pathogenesis of bronchial asthma. Pivotal role in the induction of the inflammation in atopic subjects is played by mast cells and eosinophils and their mediators. Lymphocytes T and macrophages modulate this process. Although the pathogenesis of asthma in non-atopic subjects is not totally clear the inflammation has similar course as in asthma with IgE overproduction. Current research emphasise e.g. the role of adhesion molecules, bronchial epithelial cells and nitric oxide in the pathogenesis of asthma. Selectin E, ICAM-1, VCAM-1 take part in the migration of inflammatory cells in the asthmatic lung. Expression of these molecules is included by IL-1, TNF-alpha, and IL-4. Inflammation leads to the bronchial epithelial damage and release of proinflammatory cytokines, which augment the above process. The epithelial damage causes exposure of nerve endings, which can lead to the activation of axon reflexes. The concentration of NO in the exhaled air of asthmatics is much higher than in healthy subjects. It may be produced by inflammatory cells and may augment the inflammation as well as cause bronchial hyperresponsiveness. The better understanding of inflammatory patterns of bronchial asthma has major influence on the therapeutic approach. Inhaled anti-inflammatory drugs are of the first choice in pharmacotherapy of even mild forms of asthma.
Asunto(s)
Asma/etiología , Inflamación/fisiopatología , Asma/fisiopatología , Bronquios/fisiopatología , Moléculas de Adhesión Celular/fisiología , Citocinas/fisiología , Epitelio/fisiología , Humanos , Infecciones/complicaciones , Óxido Nítrico/fisiologíaRESUMEN
Clinical study was conducted on 77 adult patients with hypersensitivity to honey bee venom (HBV) to determine clinical characteristics and pathogenesis of hypersensitivity to HBV as well as the effect of specific immunotherapy(ITS) with HBV on several clinical and immunological parameters. The patients studied (43 women and 34 men of age ranging between 18-61 years with a mean age at 30 years) were divided into two groups: Group 1-44 patients with a history of anaphylactic shock following honey bee sting, who received specific immunotherapy with HBV. Group 2-33 patients hypersensitive to HBV(9 people reacted with severe anaphylactic systemic reaction, while others had skin reactions) who were not treated by ITS method. In all patients skin tests with HBV allergen were conducted before and at various stages of immunotherapy. Specific IgE (I1), s-IgG4 (I1), total IgE, IgG, IgA, IgM, C3c, C4 were estimated in sera samples obtained at the beginning, during the course and at the end of ITS. Dynamics of changes of these parameters were studied during a 3-year period of ITS. The challenge tests were conducted at the end of the treatment. 86.9% of treated patients reacted with IgE-mediated reactions. They showed elevated levels of s-IgE before immunotherapy, and significant decrease in s-IgE and increase in s-IgG4 titers after ITS. 10.4% of patients showed clinical symptoms of anaphylaxis, but non-IgE mediated. IgE titer in these patients was < or = 0.2 IU/ml and has not significantly changed during immunotherapy. s-IgG, levels were in these patients below 2 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)