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2.
Resuscitation ; 76(3): 468-70, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17935856

RESUMO

We present a case of a patient with severe multiple trauma who was treated at the scene by a physician-staffed trauma life support team. Due to a complete tracheal transection, a "cannot ventilate, cannot intubate"-situation occurred. The patient was then intubated using a fiberoptic bronchoscope in the prehospital setting. The current literature concerning fiberoptic intubation in emergencies is discussed.


Assuntos
Broncoscópios , Tecnologia de Fibra Óptica , Intubação Intratraqueal/métodos , Acidentes de Trânsito , Idoso , Serviços Médicos de Emergência , Evolução Fatal , Parada Cardíaca , Humanos , Masculino , Traqueia/lesões
3.
Anaesthesist ; 56(5): 461-5, 2007 May.
Artigo em Alemão | MEDLINE | ID: mdl-17437072

RESUMO

PURPOSE: Preclinical emergency medical treatment necessitates a comprehensive interdisciplinary knowledge by the emergency physician as well as a high level of manual dexterity. The quality of treatment therefore depends on the level of education and continuous training in emergency medical techniques. Based on an evaluation of the frequency of life-saving interventions by a physician-staffed rescue helicopter system, strategies for in-hospital training of relevant skills are suggested. MATERIAL AND METHODS: At the outset, 10 important areas of treatment (e.g. intubation, chest tube etc.) and their frequency in emergency medical services were defined as the standard to be attained by emergency physicians within 1 year. The selection of the areas of treatment was based to some extent on international recommendations. The actual frequencies of the prehospital interventions were compared to the required minimum numbers by retrospective analysis of the helicopter rescue database (NACA-X). RESULTS: During the observation period of 1 year, 20 emergency physicians responded to 956 prehospital emergency calls. A life-threatening condition requiring an on-site intervention occurred in only 521 (54.5%) patients, so that the majority of physicians did not perform the required minimum number of interventions. In order to maintain their level of skill, the emergency physicians were required to undertake additional training at the local university hospital. CONCLUSION: The frequency of on-site life-saving interventions in emergency medicine is insufficient to fulfill the quota necessary to maintain adequate training of emergency physicians. Only a link-up program at a hospital for primary care can ensure an adequate training level.


Assuntos
Resgate Aéreo/normas , Trabalho de Resgate/normas , Competência Clínica , Bases de Dados Factuais , Serviços Médicos de Emergência , Humanos , Médicos , Garantia da Qualidade dos Cuidados de Saúde , Estudos Retrospectivos
4.
FEBS Lett ; 581(4): 741-8, 2007 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-17274986

RESUMO

Rubisco assumes the double role of accumulating biomass by fixing carbon dioxide to ribulose-1,5-bisphosphate and binding of molecular oxygen to the same substrate. The specificity factor of this mutually competitive activity, defined as the ratio of carboxylation to oxygenation efficiency, varies considerably for reasons which remain obscure. The explanation and the enhancement of specificity are of high theoretical and practical interest. Despite a wealth of structures and experimental findings, the systematic analysis of available data is still at its beginning. Here, we (a) present an analysis of sequences of the large subunit which reliably finds specificity-enhancing mutations and ranks them according to the probability of success. For mutations near the C-terminus, we (b) show by simulations that the positive influence they have on specificity can be explained by the time-window hypothesis.


Assuntos
Biologia Computacional/métodos , Mutação/genética , Subunidades Proteicas/química , Subunidades Proteicas/genética , Ribulose-Bifosfato Carboxilase/química , Ribulose-Bifosfato Carboxilase/genética , Synechococcus/enzimologia , Algoritmos , Sequência de Aminoácidos , Simulação por Computador , Sequência Conservada , Dados de Sequência Molecular , Proteínas Mutantes/química , Análise de Sequência de Proteína , Especificidade por Substrato
5.
Am J Transplant ; 7(3): 527-37, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17229070

RESUMO

The biology of chemokines and their receptors have been linked to the development of chronic allograft damage. Effects of CCR1 antagonist BX 471 were studied in a Fischer to Lewis renal transplantation model at days 10, 21 and 42 after transplantation. BX 471 treatment did not effectively reduce signs of acute rejection at day 10 but significantly improved allograft function and morphology at day 21 posttransplantation. When therapy was initiated on day 21 after transplantation, glomerulosclerosis and tubulointerstitial fibrosis were significantly inhibited by day 42 posttransplantation. Parallel decrease in infiltrating and proliferating mononuclear cells (ED1, CD8 and Ki67) was observed in treated allografts. Expression of acute phase reactive and proinflammatory genes (HO-1, osteopontin) and molecules associated with fibrosis (PAI-1, TGF-beta1, biglycan) was downregulated at day 21; reduced collagen deposition was observed, parallel to a significant lower number of alpha-SMA+ interstitial myofibroblasts. In situ hybridization demonstrated that biglycan expression was reduced following CCR1 blockade in interstitium of treated allografts. CCR1 antagonism was found to inhibit CCL5-induced secretion of biglycan by macrophages in vitro. CCR1 blockade significantly inhibited development and progression of chronic allograft damage. CCR1 antagonists may represent a therapeutic option for chronic inflammation and fibrosis in renal grafts.


Assuntos
Rejeição de Enxerto/tratamento farmacológico , Falência Renal Crônica/tratamento farmacológico , Transplante de Rim , Compostos de Fenilureia/uso terapêutico , Piperidinas/uso terapêutico , Receptores de Quimiocinas/antagonistas & inibidores , Animais , Biglicano , Progressão da Doença , Proteínas da Matriz Extracelular/antagonistas & inibidores , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Fibrose , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , Falência Renal Crônica/patologia , Ativação Linfocitária/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Modelos Animais , Compostos de Fenilureia/farmacologia , Piperidinas/farmacologia , Proteoglicanas/antagonistas & inibidores , Proteoglicanas/genética , Proteoglicanas/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ratos , Receptores CCR1 , Linfócitos T/efeitos dos fármacos
6.
Resuscitation ; 66(3): 323-30, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16095797

RESUMO

BACKGROUND AND OBJECTIVE: In the Austrian emergency medical service (EMS), emergency medical technician-staffed and physician-staffed vehicles are in operation. Patients with suspected acute coronary syndromes (ACS) are treated in the pre-hospital phase and transported to the hospital by an emergency physician (EP). This study evaluates the diagnostic performance of EPs in ACS and the impact of this emergency system on the outcome of ACS in an urban area. DESIGN: Retrospective case control study. METHODS: All protocol sheets from the emergency physicians were searched for the diagnosis of ACS. The database of the emergency department (ED) was searched for patients with ACS as an admission diagnosis or ACS as discharge diagnosis. For patients admitted to an intensive care unit (ICU), the medical history from the ICU was reviewed. According to the diagnosis and the aggressiveness of therapy, patients were divided in five categories of severity at each stage of care (pre-hospital category, ED category, ICU category). RESULTS: A total of 3585 patients was analysed. Only 17.8% of the patients with ACS as the admission diagnosis and 20.3% of the patients with ACS as the discharge diagnosis were transported by an EP. 46.8% of the ACS diagnosis by EPs were confirmed in hospital. Patients transported by EPs showed a higher all-cause mortality in hospital (1.6% vs. 0.6%; p=0.011). There was no significant correlation between the pre-hospital category of patients treated by EPs and the ED category. When a 12-lead-electrocardiogram was recorded, the correlation improved slightly (rho: 0.139; p=0.006). CONCLUSIONS: The percentage of ACS patients transported to hospital by an EP is very low, and EPs seem to be "over-aware" in the diagnosis of ACS.


Assuntos
Doença das Coronárias/diagnóstico , Serviços Médicos de Emergência/estatística & dados numéricos , Qualidade da Assistência à Saúde/estatística & dados numéricos , Doença Aguda , Áustria/epidemiologia , Estudos de Casos e Controles , Doença das Coronárias/tratamento farmacológico , Doença das Coronárias/mortalidade , Cuidados Críticos/estatística & dados numéricos , Eletrocardiografia/estatística & dados numéricos , Medicina de Emergência/estatística & dados numéricos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Humanos , Avaliação de Processos e Resultados em Cuidados de Saúde , Estudos Retrospectivos , Análise de Sobrevida , Síndrome , Terapia Trombolítica/estatística & dados numéricos
7.
Plant Biol (Stuttg) ; 7(4): 342-7, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16025406

RESUMO

Disruption of the ccmM gene in the cyanobacterium Synechocystis sp. PCC 6803 causes a deficiency of carboxysomes and impairs growth in ambient CO2. The effect of this gene defect on cellular metabolism was investigated using electron microscopy, biochemical and fluorescence analysis. Mutant cells were devoid of the characteristic dense polyhedral bodies called carboxysomes. The photosynthetic oxygen evolution was considerably lower in mutant cells compared to wild type, while Rubisco activity in cell extracts was similar. During photosynthetic CO2-dependent oxygen evolution, Rubisco Vmax dropped from 142 micromol mg-1 chlorophyll h-1 (WT) to 77 micromol mg-1 chlorophyll h-1 in the mutant cells, and the Km for Ci (inorganic carbon) increased from 0.5 mM (WT) to 40 mM. The fluorescent indicator, acridine yellow, was used for non-invasive measurements of cytoplasmic pH changes in whole cells induced by addition of Ci, making use of the decrease in fluorescence yield that accompanies cytoplasmic acidification. The experimental results indicate that control of the cytoplasmic pH is linked to the internal carbon pool (Ci). Both wild-type and ccmM-deficient cells showed a linear response of acridine yellow fluorescence quenching and, thus, of internal acidification, with respect to externally added inorganic carbon. However, the fluorescence analysis of mutant (carboxysome-free) cells indicated slower kinetics of Ci accumulation.


Assuntos
Citosol/metabolismo , Synechocystis/metabolismo , Dióxido de Carbono/metabolismo , Fluorescência , Corantes Fluorescentes , Concentração de Íons de Hidrogênio , Mutagênese Insercional , Mutação , Oxigênio/metabolismo , Fotossíntese , Synechocystis/genética , Synechocystis/ultraestrutura
8.
Exp Eye Res ; 75(2): 127-33, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12137758

RESUMO

Equine recurrent uveitis (ERU) is the most serious eye disease in horses worldwide. Despite the fact that ERU is generally considered to be immune mediated, a detailed description of the histopathology of the posterior part of ERU eyes is lacking. Here, we examined sections of paraffin-embedded eyes using histological and immunhistological methods. Twenty seven eyes of 20 horses with ERU and 30 eyes of 15 healthy control horses were included in this study. We could consistently demonstrate an involvement of the retina and the choroid in all examined eyes of horses with spontaneous ERU. In eyes with minimal histopathological changes, the infiltrates consisted almost exclusively of T-cells. Histopathological changes start with the destruction of the photoreceptor outer segments, which often leads to focal retinal detachment. In more severely affected eyes, there is additional disintegration of the ganglion cell layer and the inner nuclear layer. In almost all examined eyes, lymphoid follicle formation could be demonstrated. Typical localizations of these follicles were the iris stroma and the choroid underneath the transition zone of the retina without photoreceptor cells to the region containing photoreceptor cells. These follicles consist of a T-cell rich periphery with a small center of CD3-negative lymphocytes. In cases with extreme histopathological changes, the retinal architecture is widely disintegrated with massive infiltration of the retina, the choroid, and the ciliary body by several types of inflammatory cells. Necrotic remnants of the retina are end-stage findings and there is only a minor inflammatory infiltration left. This study provides clear evidence that the retina is involved in all stages of ERU. Inflammation is mainly driven by T-cells as T-cells were demonstrated in mild stages of the disease and are also the predominating cell type in all other stages of ERU.


Assuntos
Doenças dos Cavalos/imunologia , Uveíte/veterinária , Animais , Corioide/imunologia , Corioide/patologia , Corpo Ciliar/imunologia , Corpo Ciliar/patologia , Doenças dos Cavalos/patologia , Cavalos , Iris/imunologia , Iris/patologia , Disco Óptico/imunologia , Disco Óptico/patologia , Células Fotorreceptoras de Vertebrados/imunologia , Recidiva , Retina/imunologia , Retina/patologia , Linfócitos T/imunologia , Uveíte/imunologia , Uveíte/patologia
9.
Resuscitation ; 51(3): 297-300, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11738782

RESUMO

During cardiopulmonary resuscitation, pH and base excess (BE) decrease to a variable degree due to metabolic acidosis. The main cause has been shown to be lactate, which cannot be eliminated sufficiently because of low perfusion during cardiac massage. Both BE and lactate can be measured in the prehospital phase. The aim of the study was to determine if BE and lactate are comparable variables during cardiopulmonary resuscitation (CPR) and if the measurement of lactate level alone would be sufficient to determine the patient's metabolic status and sufficiently reliable to determine the administration of buffer solutions. During the observation period, we registered 31 patients (21 males, ten females) who were resuscitated according to European Resuscitation Council recommendations, who had blood gas analysis and lactate levels measured in blood taken by arterial puncture or arterial line. The first measurement from each patient was taken after primary resuscitation (within 5-20 min). The mean lactate level was 9.85+/-2.98 (range, 4.1-18.7) mmol/l, and the mean BE was -15.0+/-5.98 (range, 5.5 to -24.3). There were statistically significant correlations between the lactate level and BE and pH (linear correlation, r=-0.673, P<0,001 and r=-0,683, P<0,001, respectively), but not with pO2 and pCO2. The receiver-operated curve analysis showed that a cut-off point of 7.0 mmol/l lactate indicates a BE below -10 with a sensitivity of 96% and a specificity of 67%. Lactate measurement is a valuable tool to determine metabolic acidosis during CPR and may be able to replace blood gas analysis in this situation.


Assuntos
Acidose/diagnóstico , Reanimação Cardiopulmonar , Parada Cardíaca/metabolismo , Ácido Láctico/sangue , Idoso , Gasometria , Feminino , Humanos , Masculino , Curva ROC , Sensibilidade e Especificidade
10.
Invest Ophthalmol Vis Sci ; 42(2): 393-8, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11157872

RESUMO

PURPOSE: To test the hypothesis that autoimmune mechanisms are involved in horses in which equine recurrent uveitis (ERU) develops spontaneously. METHODS: Material obtained from horses treated for spontaneous disease by therapeutic routine vitrectomy was analyzed for total IgG content and IgG specific for S-Antigen (S-Ag) and interphotoreceptor retinoid-binding protein (IRBP). The cellular infiltrate of the vitreous was analyzed by differential counts of cytospin preparations and flow cytometry using equine lymphocyte-specific antibodies. Antigen-specific proliferation assays were performed comparing peripheral blood lymphocytes (PBLs) with vitreal lymphocytes by stimulation with S-Ag and several S-Ag- and IRBP-derived peptides. RESULTS: The total IgG content of specimens from horses with ERU was very high with great variability among the investigated samples (11.5 +/- 8.0 mg). Autoantibodies to S-Ag or IRBP or both were found in 72% of vitreous specimens from horses with uveitis. The leukocyte infiltrates (up to 2 x 10(8) cells per sample) were dominated by lymphocytes (>90%) in most cases (22/32). Flow cytometry showed that more than 50% of these cells were CD4(+) T cells. In vitro stimulation of vitreal lymphocytes, but not of PBL, showed a strong proliferative response to peptides derived from S-Ag or IRBP in 9 of 12 patients. CONCLUSIONS: In the eyes of horses with ERU, IgG antibodies and autoreactive T cells specific for retinal antigens were detected. These results strongly support the hypothesis that ERU is an autoimmune-mediated disease and is highly similar to recurrent uveitis in humans in both clinical and immunologic parameters.


Assuntos
Autoanticorpos/análise , Autoantígenos/imunologia , Doenças Autoimunes/veterinária , Proteínas do Olho , Doenças dos Cavalos/imunologia , Fragmentos de Peptídeos/imunologia , Retina/imunologia , Uveíte/veterinária , Animais , Formação de Anticorpos , Arrestina/imunologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/cirurgia , Linfócitos T CD4-Positivos/imunologia , Citometria de Fluxo/veterinária , Doenças dos Cavalos/cirurgia , Cavalos , Imunoglobulina G/análise , Imunofenotipagem/veterinária , Ativação Linfocitária , Recidiva , Proteínas de Ligação ao Retinol/imunologia , Uveíte/imunologia , Uveíte/cirurgia , Vitrectomia/veterinária , Corpo Vítreo/citologia , Corpo Vítreo/imunologia
12.
Clin Exp Immunol ; 120(1): 162-6, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10759778

RESUMO

Immune response to retinal autoantigens plays a central role in the pathogenesis of uveitis. A synthetic peptide (B27PD) from a common sequence of various HLA-B molecules associated with uveitis, such as HLA-B27 and 51, which shares amino acid homologies with a retinal-S antigen (S-Ag)-derived peptide (PDSAg), was shown to be immunogenic in human and experimental uveitis in the rat. In this study we investigated T cell responses to B27PD and PDSAg in patients with Behçet's disease and posterior uveitis (BD-posterior uveitis; n = 33) in comparison with non-Behçet anterior uveitis (AU, n = 14), Behçet's patients without uveitis (BD, n = 15) and healthy controls (HC, n = 32) in a 6-day proliferation assay. Patients with BD and posterior uveitis had significantly higher responses (stimulation index (SI) 2.8 +/- 1.3) than those with AU (SI 1.5 +/- 0.4), BD without uveitis (SI 1.1 +/- 0.4) and HC (SI 1.1 +/- 0.6) for B27PD (P < 0.0001). Responses to PDSAg were also higher in BD with posterior uveitis patients (SI 3.3 +/- 1.6) than AU (SI 1.5 +/- 0.4), BD without uveitis (SI 1.2 +/- 0.3) and HC (SI 1.1 +/- 0.6) (P < 0. 0001). A significant correlation between the responses to PDSAg and B27PD (r = 0.56, P < 0.001) was observed. Elevated levels of IL-2 and tumour necrosis factor-alpha were also observed in culture supernatants obtained from peripheral blood mononuclear cells after stimulation with the peptides, but no correlation was found between the proliferative responses and cytokine levels. These results suggest that cellular immunity to cross-reactive HLA-B and S-Ag-derived peptides might play a role in the pathogenesis of posterior uveitis in BD.


Assuntos
Arrestina/imunologia , Doenças Autoimunes/imunologia , Síndrome de Behçet/imunologia , Antígenos HLA-B/imunologia , Antígeno HLA-B27/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Uveíte Anterior/imunologia , Adulto , Arrestina/química , Divisão Celular/imunologia , Células Cultivadas , Meios de Cultivo Condicionados/química , Feminino , Antígenos HLA-B/química , Antígeno HLA-B27/química , Antígeno HLA-B51 , Humanos , Interleucina-2/metabolismo , Ativação Linfocitária/imunologia , Masculino , Retina/imunologia , Fator de Necrose Tumoral alfa/metabolismo
13.
Photosynth Res ; 65(1): 7-13, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-16228466

RESUMO

The molecular basis of Rubisco's specificity is investigated in terms of the structure and kinetics of the enzyme. We propose that the rates of the conformational changes (closing/opening) of the binding niche exert a crucial influence on apparent binding rates and the enzyme's specificity. An extended reaction scheme for binding and conformational kinetics is presented and expressed in a mathematical model. The closed conformation, known from X-ray structures, is assumed to be necessary for binding of the gaseous substrates (carbon dioxide and oxygen) and for catalysis. Opening the niche interrupts catalysis and enables a fast exchange of those molecules between the internal cavity and the surrounding solvent. Our model predicts that specificity of Rubisco for CO(2) increases with the rate by which the niche opens. This is due to the fact that binding of the carbon dioxide is faster than oxygen binding, which is hampered by spin inversion. The apparent rate of carbon dioxide binding correlates with the repetition rate of the conformational change, and the rate of oxygen binding with the probability of the closed state.

14.
Immunol Lett ; 68(2-3): 205-12, 1999 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10424422

RESUMO

Endogenous uveitis is a T cell mediated autoimmune disease leading to impairment of visual acuity. The association of different uveitis entities with HLA-class I antigens and the discovery of antigenic mimicry between a peptide of uveitis-associated HLA-class I antigens and a peptide of retinal autoantigen led to a new hypothesis for the pathogenesis of uveitis. On the basis of this mechanism an open trial of oral tolerance induction with the HLA-peptide B27PD was initiated for nine patients with long lasting, therapy-refractive uveitis. Within 6 weeks of oral peptide treatment all patients responded with a marked decrease of intraocular inflammation, which allowed a reduction of systemic corticosteroids in seven patients. One patient, who suffered from an acute relapse, responded within 2 weeks, followed by an increase of visual acuity. In addition, two patients discontinued azathioprine immediately prior to oral tolerance induction without the occurrence of relapses. Visual acuity remained unchanged or increased in 14 of 16 eyes. One patient did not finish oral peptide treatment. None of these patients experienced any adverse events. It was concluded that the oral application of highly tolerogenic peptides might be a potent approach for the treatment of autoimmune diseases.


Assuntos
Arrestina/imunologia , Doenças Autoimunes/terapia , Antígeno HLA-B27/uso terapêutico , Tolerância Imunológica , Peptídeos/uso terapêutico , Uveíte/terapia , Administração Oral , Adolescente , Adulto , Doenças Autoimunes/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mimetismo Molecular , Uveíte/etiologia
16.
Arthritis Rheum ; 40(11): 2047-54, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9365095

RESUMO

OBJECTIVE: To study whether peptides derived from the HLA-B27 molecule sequence can stimulate peripheral blood T lymphocytes (PBL) from patients with HLA-B27-associated spondylarthropathies. METHODS: PBL from 55 HLA-B27+ patients with ankylosing spondylitis (AS), 28 HLA-B27+ patients with other spondylarthropathies, 7 rheumatoid arthritis patients, and 30 HLA-B27+ and 22 HLA-B27- healthy controls were tested in lymphocyte proliferation assays with 4 synthetic peptides derived from the HLA-B*2705 molecule. RESULTS: A 13-mer peptide (B27PA) induced significant proliferative responses in 17 of the 55 AS patients (stimulation index [SI] 2.5-17.5), as well as in 3 of the HLA-B27+ healthy controls (SI 2.5-9.8). Another 13-mer peptide (B27PC) induced PBL proliferation (SI 2.7-5.5) in 10 AS patients and in some donors of the control groups. In B27PA-specific T cell lines, an expansion of cells positive for the gamma/delta T cell receptor could be demonstrated. CONCLUSION: These results indicate that HLA-B27-derived peptides can be recognized as autoantigens by PBL of HLA-B27+ AS patients and B27+ healthy controls. Recent infections preceding the manifestation of AS may be involved in this process of anti-self major histocompatibility complex reactivity.


Assuntos
Autoantígenos/imunologia , Antígeno HLA-B27/análise , Espondilite Anquilosante/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Idoso , Linhagem Celular , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Citometria de Fluxo , Antígeno HLA-B27/química , Humanos , Interferon gama/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Peptídeos/farmacologia , Fenótipo , Receptores de Antígenos de Linfócitos T gama-delta/genética , Espondilite Anquilosante/sangue , Linfócitos T/metabolismo
17.
Immunol Lett ; 57(1-3): 193-201, 1997 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-9232451

RESUMO

In the rat model of experimental autoimmune uveitis (EAU) we have demonstrated that a peptide from the sequence of human disease-associated MHC-class I antigens can induce uveitis upon immunization. Moreover, oral administration of this MHC-peptide tolerized Lewis rats to the disease induced with two different retinal autoantigens, retinal S-antigen (S-Ag) and IRBP. In uveitis patients T cells responding to S-Ag peptide also respond to the MHC-peptide, which shows crossreactivity with the major epitope from S-Ag due to some shared discontinuous amino acid homologies. The 14-mer peptide B27PD is derived from the sequence of all HLA-B antigens that are statistically associated with uveitis (including HLA-B27). Patients with long-lasting endogenous uveitis, suffering from side effects of conventional immuno-suppressive therapy or being therapy-refractive, were orally tolerized with peptide B27PD in this first open therapeutic trial. Patients received peptide three times a week over a 12 weeks period, while only low dose steroids were allowed as concomitant medication. The aims were (1) to investigate whether immunosuppressive therapy could be discontinued and steroids reduced while relapses of ocular inflammation reside and (2) to search for side effects. The Helsinki Declaration was strictly observed and the study design approved by the local ethical committee. The first patients orally tolerized with the HLA-peptide (two had stopped azathioprine immediately prior to onset of oral peptide treatment) could discontinue their steroids because of reduced intraocular inflammation. No side effects of therapy were observed. Oral tolerance induction with a peptide derived from the patients' own HLA-antigens and crossreactive with the organ-specific autoantigen seems to be a potent therapeutic approach.


Assuntos
Doenças Autoimunes/tratamento farmacológico , Antígenos HLA/uso terapêutico , Peptídeos/uso terapêutico , Uveíte/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Animais , Arrestina/química , Doenças Autoimunes/imunologia , Reações Cruzadas , Relação Dose-Resposta a Droga , Estudos de Viabilidade , Feminino , Seguimentos , Antígenos HLA/química , Antígenos HLA/imunologia , Antígeno HLA-B27/química , Humanos , Masculino , Mimetismo Molecular , Peptídeos/química , Peptídeos/imunologia , Ratos , Ratos Endogâmicos Lew , Fatores de Tempo , Uveíte/imunologia
19.
Eur J Immunol ; 26(9): 2140-8, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8814259

RESUMO

We investigated the role of gamma/delta TCR+ T cells in induction and suppression of the T cell-mediated disease experimental autoimmune uveitis. Disease induction was studied in Lewis rats perinatally depleted of alpha/beta or gamma/delta TCR+ subpopulations. Depletion of alpha/beta TCR+ cells completely abrogated disease, whereas treatment with anti-gamma/delta antibodies had no influence on onset or intensity of uveitis. However, adoptively transferred gamma/delta+ cells from orally tolerized rats could mediate suppression of uveitis in an antigen-specific fashion. Uveitis induced by a peptide derived from the uveitogenic retinal soluble antigen (S-Ag) was suppressed by gamma/delta+ cells from rats orally tolerized with the same peptide as well as HLA peptide B27PD. This disease ameliorating effect could also be observed when rats were fed with the HLA peptide before immunization with S-Ag peptide. Transfer of alpha/beta+ T cells from the same donors as well as gamma/delta+ or alpha/beta+ cells from animals fed with control peptide had no ameliorating effect.


Assuntos
Doenças Autoimunes/prevenção & controle , Fragmentos de Peptídeos/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/fisiologia , Linfócitos T/fisiologia , Uveíte/prevenção & controle , Administração Oral , Sequência de Aminoácidos , Animais , Imunoterapia Adotiva , Ativação Linfocitária , Dados de Sequência Molecular , Ratos , Ratos Endogâmicos Lew , Linfócitos T/imunologia
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