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1.
Artigo em Inglês | MEDLINE | ID: mdl-36331131

RESUMO

BACKGROUND: Cashew nuts often cause strong allergic reactions, even exceeding those of peanuts. Ana o 1 (vicilin), Ana o 2 (legumin) and Ana o 3 (2S albumin) are major cashew allergens. Co-sensitization to all three non-homologous cashew nut allergens has been observed. We hypothesize that this might be due to IgE cross-reactivity. METHODS: IgE cross-inhibitions were performed with Ana o 1-3 using sera from cashew nut allergic patients. Related hazelnut allergens Cor a 11, 9 and 14 were used as controls. For comparison, IgE cross-reactivity between the hazelnut allergens was investigated using sera from hazelnut allergic patients. RESULTS: Median percentages of cross-inhibitions between Ana o 1-3 were 84-99%. In comparison, medians of cross-inhibitions between hazelnut allergens were 33-62%. The IC50 values revealed the highest IgE affinity to Ana o 3 and Cor a 14. Hazelnut legumin Cor a 9 inhibited IgE-binding to Ana o 1, 2, and 3 with median percentages of 75%, 56%, and 48%, respectively. No cross-reactivity was observed between allergenic vicilins or between 2S albumins from cashew and hazelnut. In silico identified potentially cross-reactive peptides of Ana o 3 overlapped with previously reported IgE epitopes of all three allergens. CONCLUSIONS: IgE with high affinity to Ana o 3 that cross-reacts with the other two major non-homologous cashew nut allergens might be responsible for the high allergenic potency of cashew nut. These cross-reactive IgE comprises the major fraction of specific IgE in cashew allergic patients, and might be responsible for cross-reactivity between unrelated tree nuts.

3.
Allergy ; 73(4): 799-815, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29205393

RESUMO

Food allergy can result in considerable morbidity, impairment of quality of life, and healthcare expenditure. There is therefore interest in novel strategies for its treatment, particularly food allergen immunotherapy (FA-AIT) through the oral (OIT), sublingual (SLIT), or epicutaneous (EPIT) routes. This Guideline, prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Task Force on Allergen Immunotherapy for IgE-mediated Food Allergy, aims to provide evidence-based recommendations for active treatment of IgE-mediated food allergy with FA-AIT. Immunotherapy relies on the delivery of gradually increasing doses of specific allergen to increase the threshold of reaction while on therapy (also known as desensitization) and ultimately to achieve post-discontinuation effectiveness (also known as tolerance or sustained unresponsiveness). Oral FA-AIT has most frequently been assessed: here, the allergen is either immediately swallowed (OIT) or held under the tongue for a period of time (SLIT). Overall, trials have found substantial benefit for patients undergoing either OIT or SLIT with respect to efficacy during treatment, particularly for cow's milk, hen's egg, and peanut allergies. A benefit post-discontinuation is also suggested, but not confirmed. Adverse events during FA-AIT have been frequently reported, but few subjects discontinue FA-AIT as a result of these. Taking into account the current evidence, FA-AIT should only be performed in research centers or in clinical centers with an extensive experience in FA-AIT. Patients and their families should be provided with information about the use of FA-AIT for IgE-mediated food allergy to allow them to make an informed decision about the therapy.


Assuntos
Dessensibilização Imunológica/métodos , Dessensibilização Imunológica/normas , Hipersensibilidade Alimentar/prevenção & controle , Animais , Humanos , Imunoglobulina E/imunologia
4.
Allergy ; 72(7): 1006-1021, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28122115

RESUMO

This consensus document summarizes the current knowledge on the potential for precision medicine in food allergy, drug allergy, and anaphylaxis under the auspices of the PRACTALL collaboration platform. PRACTALL is a joint effort of the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma and Immunology, which aims to synchronize the European and American approaches to allergy care. Precision medicine is an emerging approach for disease treatment based on disease endotypes, which are phenotypic subclasses associated with specific mechanisms underlying the disease. Although significant progress has been made in defining endotypes for asthma, definitions of endotypes for food and drug allergy or for anaphylaxis lag behind. Progress has been made in discovery of biomarkers to guide a precision medicine approach to treatment of food and drug allergy, but further validation and quantification of these biomarkers are needed to allow their translation into practice in the clinical management of allergic disease.


Assuntos
Hipersensibilidade/etiologia , Hipersensibilidade/terapia , Medicina de Precisão , Idade de Início , Alérgenos/imunologia , Anafilaxia/diagnóstico , Anafilaxia/imunologia , Anafilaxia/terapia , Biomarcadores , Comorbidade , Hipersensibilidade a Drogas/diagnóstico , Hipersensibilidade a Drogas/imunologia , Hipersensibilidade a Drogas/terapia , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/terapia , Humanos , Hipersensibilidade/diagnóstico , Fenótipo , Medicina de Precisão/métodos , Índice de Gravidade de Doença
5.
Allergy ; 72(8): 1133-1147, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28058751

RESUMO

BACKGROUND: The European Academy of Allergy and Clinical Immunology (EAACI) is developing Guidelines for Allergen Immunotherapy (AIT) for IgE-mediated Food Allergy. To inform the development of clinical recommendations, we sought to critically assess evidence on the effectiveness, safety and cost-effectiveness of AIT in the management of food allergy. METHODS: We undertook a systematic review and meta-analysis that involved searching nine international electronic databases for randomized controlled trials (RCTs) and nonrandomized studies (NRS). Eligible studies were independently assessed by two reviewers against predefined eligibility criteria. The quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs and the Cochrane ACROBAT-NRS tool for quasi-RCTs. Random-effects meta-analyses were undertaken, with planned subgroup and sensitivity analyses. RESULTS: We identified 1814 potentially relevant papers from which we selected 31 eligible studies, comprising of 25 RCTs and six NRS, studying a total of 1259 patients. Twenty-five trials evaluated oral immunotherapy (OIT), five studies investigated sublingual immunotherapy, and one study evaluated epicutaneous immunotherapy. The majority of these studies were in children. Twenty-seven studies assessed desensitization, and eight studies investigated sustained unresponsiveness postdiscontinuation of AIT. Meta-analyses demonstrated a substantial benefit in terms of desensitization (risk ratio (RR) = 0.16, 95% CI 0.10, 0.26) and suggested, but did not confirm sustained unresponsiveness (RR = 0.29, 95% CI 0.08, 1.13). Only one study reported on disease-specific quality of life (QoL), which reported no comparative results between OIT and control group. Meta-analyses revealed that the risk of experiencing a systemic adverse reaction was higher in those receiving AIT, with a more marked increase in the risk of local adverse reactions. Sensitivity analysis excluding those studies judged to be at high risk of bias demonstrated the robustness of summary estimates of effectiveness and safety of AIT for food allergy. None of the studies reported data on health economic analyses. CONCLUSIONS: AIT may be effective in raising the threshold of reactivity to a range of foods in children with IgE-mediated food allergy whilst receiving (i.e. desensitization) and post-discontinuation of AIT. It is, however, associated with a modest increased risk in serious systemic adverse reactions and a substantial increase in minor local adverse reactions. More data are needed in relation to adults, long term effects, the impact on QoL and the cost-effectiveness of AIT.


Assuntos
Alérgenos/imunologia , Dessensibilização Imunológica , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/terapia , Alimentos/efeitos adversos , Imunoglobulina E/imunologia , Alérgenos/administração & dosagem , Animais , Dessensibilização Imunológica/métodos , Humanos , Razão de Chances , Qualidade de Vida , Imunoterapia Sublingual , Resultado do Tratamento
6.
Health Educ Res ; 31(1): 70-81, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26612050

RESUMO

Health literacy is 'the capacity to obtain, process and understand basic health information and services needed to make appropriate health decisions'. Although numerous studies show a link between health literacy and clinical outcomes, little research has examined the association of health literacy with oral health. No large-scale studies have assessed these relationships among American Indians, a population at risk for limited health literacy and oral health problems. This analysis was conducted as part of a clinical trial aimed at reducing dental decay among preschoolers in the Navajo Nation Head Start program. Using baseline data for 1016 parent-child dyads, we examined the association of parental health literacy with parents' oral health knowledge, attitudes, and behavior, as well as indicators of parental and pediatric oral health. More limited health literacy was associated with lower levels of oral health knowledge, more negative oral health attitudes, and lower levels of adherence to recommended oral health behavior. Parents with more limited health literacy also had significantly worse oral health status (OHS) and reported their children to have significantly worse oral health-related quality of life. These results highlight the importance of oral health promotion interventions that are sensitive to the needs of participants with limited health literacy.


Assuntos
Saúde da Criança , Letramento em Saúde , Indígenas Norte-Americanos , Saúde Bucal/educação , Pais/educação , Adulto , Idoso , Idoso de 80 Anos ou mais , Pré-Escolar , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
7.
Clin Exp Allergy ; 45(1): 238-48, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25048800

RESUMO

BACKGROUND: Evidence suggests that exposure to polycyclic aromatic hydrocarbons (PAHs) increases atopy; it is unclear how PAH exposure is linked to increased severity of atopic diseases. OBJECTIVE: We hypothesized that ambient PAH exposure is linked to impairment of immunity in atopic children (defined as children with asthma and/or allergic rhinitis) from Fresno, California, an area with elevated ambient PAHs. METHODS: We recruited 256 subjects from Fresno, CA. Ambient PAH concentrations (ng/m(3) ) were measured using a spatial-temporal regression model over multiple time periods. Asthma diagnosis was determined by current NHLBI criteria. Phenotyping and functional immune measurements were performed from isolated cells. For epigenetic measurements, DNA was isolated and pyrosequenced. RESULTS: We show that higher average PAH exposure was significantly associated with impaired Treg function and increased methylation in the forkhead box protein 3 (FOXP3) locus (P < 0.05), conditional on atopic status. These epigenetic modifications were significantly linked to differential protein expression of FOXP3 (P < 0.001). Methylation was associated with cellular functional changes, specifically Treg dysfunction, and an increase in total plasma IgE levels. Protein expression of IL-10 decreased and IFN-γ increased as the extent of PAH exposure increased. The strength of the associations generally increased as the time window for average PAH exposure increased from 24 hr to 1 year, suggesting more of a chronic response. Significant associations with chronic PAH exposure and immune outcomes were also observed in subjects with allergic rhinitis. CONCLUSIONS AND CLINICAL RELEVANCE: Collectively, these results demonstrate that increased ambient PAH exposure is associated with impaired systemic immunity and epigenetic modifications in a key locus involved in atopy: FOXP3, with a higher impact on atopic children. The results suggest that increased atopic clinical symptoms in children could be linked to increased PAH exposure in air pollution.


Assuntos
Poluição do Ar/efeitos adversos , Asma , Exposição Ambiental/efeitos adversos , Epigênese Genética/efeitos dos fármacos , Imunidade Celular/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Rinite Alérgica , Linfócitos T Reguladores/imunologia , Asma/induzido quimicamente , Asma/imunologia , Criança , Pré-Escolar , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/imunologia , Epigênese Genética/imunologia , Feminino , Fatores de Transcrição Forkhead/imunologia , Humanos , Imunoglobulina E/imunologia , Lactente , Interferon gama/imunologia , Interleucina-10/imunologia , Masculino , Rinite Alérgica/induzido quimicamente , Rinite Alérgica/imunologia
8.
Opt Lett ; 38(18): 3566-9, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-24104815

RESUMO

We present the results of a feasibility study with spatial frequency domain imaging (SFDI) to produce quantitative measurements of optical property and chromophore concentration maps of three porcine kidneys utilizing a renal occlusion model at the near-infrared wavelengths of 658, 730, and 850 nm. Using SFDI, we examined the dynamics of absolute oxygen saturation (StO2). The mean StO2 for the kidneys varied from approximately 60% before occlusion, to 20% during occlusion, to 55% after reperfusion. We also present, for the first time to the best of our knowledge, reduced scattering coefficient (µ(s)') maps of the kidney during occlusion. We observed a substantial decrease in the wavelength dependence of scattering (i.e., scattering power) in the three kidneys, with a mean decrease of 18%±2.6%, which is indicative of an increase in scatterer size, and is likely due to tissue changes such as edema that follow from occlusion and inflammation.


Assuntos
Arteriopatias Oclusivas/diagnóstico , Arteriopatias Oclusivas/metabolismo , Diagnóstico por Imagem/métodos , Rim/irrigação sanguínea , Imagem Óptica/métodos , Animais , Modelos Animais de Doenças , Feminino , Rim/metabolismo , Rim/patologia , Fenômenos Ópticos , Oxigênio/metabolismo , Suínos
9.
Int Arch Allergy Immunol ; 159(2): 179-82, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22678151

RESUMO

BACKGROUND: Peanut allergy is the leading cause of food-related anaphylaxis, and accidental exposures are common. Oral immunotherapy (OIT) has been posited as a potential treatment. METHODS: Patients aged 3-65 years with peanut-specific IgE ≥7 kU/l and/or a positive skin prick test with a history of an allergic reaction to peanut were recruited to undergo an OIT protocol. All adverse reactions were recorded by research staff or patients in real time. RESULTS: Twenty-four patients received 6,662 doses. Symptoms were mostly mild (84%), and only 3 severe gastrointestinal reactions required the administration of epinephrine. Abdominal pain was the most common reaction, followed by oropharyngeal and lip pruritus. Respiratory symptoms were rare. CONCLUSIONS: In this trial of OIT in adults and children, most reactions were mild.


Assuntos
Dessensibilização Imunológica/efeitos adversos , Hipersensibilidade a Amendoim/terapia , Administração Oral , Adolescente , Adulto , Alérgenos/administração & dosagem , Alérgenos/efeitos adversos , Arachis/efeitos adversos , Arachis/imunologia , Criança , Pré-Escolar , Dessensibilização Imunológica/métodos , Feminino , Humanos , Imunoglobulina E/sangue , Masculino , Pessoa de Meia-Idade , Hipersensibilidade a Amendoim/diagnóstico , Hipersensibilidade a Amendoim/imunologia , Proteínas de Vegetais Comestíveis/administração & dosagem , Proteínas de Vegetais Comestíveis/efeitos adversos , Segurança , Testes Cutâneos
10.
Diabetologia ; 54(1): 78-86, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20886205

RESUMO

AIMS/HYPOTHESIS: The ability to measure insulin sensitivity across the phenotypic spectrum of diabetes may contribute to a more accurate characterisation of diabetes type. Our goal was to develop and validate an insulin sensitivity (IS) score using the euglycaemic-hyperinsulinaemic clamp in a subset (n = 85) of 12- to 19-year-old youths with diabetes participating in the SEARCH study in Colorado, USA. METHODS: Youths with a diagnosis of type 1 (n = 60) or type 2 diabetes (n = 25) underwent a 3 h clamp to measure glucose disposal rate (GDR, mg kg⁻¹ min⁻¹). Demographic (age, sex, race), clinical (BMI, waist, Tanner stage) and metabolic characteristics (HbA1(c), lipids, blood pressure, urine albumin:creatinine) were used to estimate log(e)IS score via stepwise linear regression on a model-development set (n = 53). Estimated IS score was evaluated for reproducibility on two validation sets: youths with diabetes (n = 33) and healthy control youths (n = 22). RESULTS: The best model included waist, triacylglycerol (TG) and HbA1(c) levels (R² = 0.74). Diabetes type did not enter the model and there were no significant interactions between diabetes type and other predictors. Estimated IS score correlated well (r = 0.65, p < 0.0001; r = 0.62, p = 0.002) with GDR on the two validation sets. Based on this analysis, we propose the following formula to estimate insulin sensitivity in youths with diabetes: [Formula: see text]. CONCLUSIONS/INTERPRETATION: Insulin sensitivity can be estimated in adolescents with diabetes using routinely collected measures. This score can be applied to epidemiological studies of youths with diabetes to characterise relationships between dimensions of diabetes type.


Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Insulina/uso terapêutico , Adolescente , Adulto , Criança , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Técnica Clamp de Glucose , Humanos , Hipoglicemiantes/metabolismo , Hipoglicemiantes/uso terapêutico , Insulina/metabolismo , Modelos Lineares , Masculino , Triglicerídeos/sangue , Circunferência da Cintura , Adulto Jovem
11.
Diabet Med ; 28(2): 148-55, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21219421

RESUMO

AIMS: Insulin resistance and dyslipidaemia both increase cardiovascular risk in Type 1 diabetes. However, little data exist on the associations of insulin resistance to lipids in Type 1 diabetes. Our objective was to explore the associations between insulin resistance (assessed by glucose infusion rate) and lipids in people with Type 1 diabetes and determine whether adiposity and/or average glycaemia influence these associations. METHODS: Hyperinsulinaemic-euglycaemic clamp studies were performed in 60 subjects with Type 1 diabetes aged 12-19 years (age 15±2 years, 57% female, duration of diabetes 6.3±3.8 years, HbA(1c) 8.6±1.5%, IFCC=70 mmol/mol) and 40 subjects with Type 1 diabetes aged 27-61 years (age 45±9 years, 53% female, duration of diabetes 23±8 years, HbA(1c) 7.5±0.9%, IFCC=58 mmol/mol). Multiple linear regression models were fit to examine the association between glucose infusion rate and fasting lipid levels with adjustment for possible confounders. RESULTS: Lower glucose infusion rate was significantly associated with lower levels of HDL cholesterol in youths with Type 1 diabetes and with higher levels of triglycerides and higher triglyceride/HDL ratio in both youths and adults. The magnitude of the associations between glucose infusion rate and lipid levels translate into interquartile differences of 0.098 mmol/l for HDL cholesterol, 0.17 mmol/l for triglycerides and 1.06 for triglycerides/HDL in the adolescents and 0.20 mmol/l for triglycerides and 1.01 for triglycerides/HDL in the adults. The associations were attenuated and no longer statistically significant by adjustment for adiposity among adults, while adjustment for HbA(1c) had a small effect in youths and adults. CONCLUSIONS: Lower insulin sensitivity is associated with a more atherogenic lipid profile in both youths and adults with Type 1 diabetes.


Assuntos
Calcinose/fisiopatologia , Doença da Artéria Coronariana/fisiopatologia , Diabetes Mellitus Tipo 1/fisiopatologia , Angiopatias Diabéticas/fisiopatologia , Resistência à Insulina/fisiologia , Lipídeos/sangue , Adolescente , Adulto , Criança , HDL-Colesterol/sangue , Doença da Artéria Coronariana/metabolismo , Doença da Artéria Coronariana/mortalidade , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/mortalidade , Angiopatias Diabéticas/metabolismo , Angiopatias Diabéticas/mortalidade , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Triglicerídeos/sangue , Adulto Jovem
12.
Trends Biochem Sci ; 16(8): 305-9, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1957352

RESUMO

Trypanosoma and Leishmania are parasitic protozoa that cause a variety of diseases, which include African sleeping sickness and oriental sore. Attempts to determine pharmaceutically exploitable differences between host and parasite biochemistry have identified the unique trypanothione pathway as a possible target. This pathway includes the enzyme trypanothione reductase, the parasite analogue of glutathione reductase.


Assuntos
Antiprotozoários/farmacologia , NADH NADPH Oxirredutases/antagonistas & inibidores , Animais , Desenho de Fármacos , Glutationa/análogos & derivados , Glutationa/metabolismo , Leishmania/efeitos dos fármacos , Leishmania/metabolismo , Mutação , NADH NADPH Oxirredutases/genética , Espermidina/análogos & derivados , Espermidina/metabolismo , Trypanosoma/efeitos dos fármacos , Trypanosoma/metabolismo
13.
J Clin Invest ; 100(5): 1199-203, 1997 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9276737

RESUMO

Ischemia/reperfusion injury associated with organ retrieval and storage influences the development of chronic graft dysfunction, the major clinical problem in solid organ transplantation. The potential role of mononuclear cells (T cells and monocyte/macrophages) in this type of injury is unknown. Inbred male Lewis rats were uninephrectomized and the left kidney perfused in situ with 10 ml of iced University of Wisconsin solution. Immunohistological studies showed mononuclear cell infiltration of the ischemic organs associated with the upregulation of MHC class II antigen expression. Reverse transcriptase-PCR indicated that T cell associated cytokines and monocyte/macrophage activation markers/products are upregulated early after the ischemic insult. B7 expression occurred within 24 h and peaked at 3 d. Plasma creatinine levels rose transiently with complete recovery of renal function by 5 d. Animals began to develop progressive proteinuria after 8-12 wk, indicative of the long-term functional consequences of early ischemia/reperfusion injury. Blockade of T cell CD28-B7 costimulation with CTLA4Ig resulted in significant inhibition of T cell and macrophage infiltration and activation in situ. Treated animals did not exhibit transient renal dysfunction, nor developed proteinuria over time. This is the first demonstration that blocking T cell costimulatory activation in the absence of alloantigen can prevent the early and late consequences of ischemia/reperfusion injury.


Assuntos
Antígeno B7-1/fisiologia , Imunoconjugados , Rim/irrigação sanguínea , Traumatismo por Reperfusão/etiologia , Abatacepte , Animais , Antígenos CD , Antígenos de Diferenciação/farmacologia , Antígeno CTLA-4 , Antígenos de Histocompatibilidade Classe II/análise , Isquemia/complicações , Masculino , Ratos , Ratos Endogâmicos Lew , Traumatismo por Reperfusão/prevenção & controle
15.
J Clin Invest ; 101(11): 2309-18, 1998 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-9616202

RESUMO

Early blockade of T cell-costimulatory activation pathways prevents development of experimental chronic allograft rejection. Ongoing T cell recognition of alloantigen and activation may also play an important role in progression of chronic rejection, but definitive evidence is lacking. We used the fusion protein CTLA4Ig to block CD28-B7 T cell costimulation late after the onset of initial graft injury. Using the F334 into LEW rat model of chronic renal allograft rejection, transplant recipients were treated with a 10-d course of cyclosporine, and a subgroup received a single injection of CTLA4Ig at 8 wk after transplant. Functionally, CTLA4Ig administration prevented development of progressive proteinuria (14.3+/-4.1 mg/24 h versus 41.0+/-12.0 mg/24 h at 24 wk after transplant, P < 0.05). Histologically, graft mononuclear cell infiltration, glomerular hypertrophy, focal and segmental glomerulosclerosis, and intimal vascular hyperplasia were all attenuated in CTLA4Ig-treated animals. Lastly, reverse transcriptase-PCR and immunohistologic studies showed a significant reduction in the intragraft expression of key products of T cell and macrophage activation, and upregulation of what have recently been termed as "protective" genes, including the bcl family members, Bcl-2 and Bcl-xL, and hemoxygenase. Our data are the first to demonstrate that blocking T cell-costimulatory activation late after transplantation, after initial graft injury, prevents progression of chronic allograft rejection supporting the hypothesis that ongoing T cell recognition of alloantigen and activation are key mediators of ongoing chronic allograft rejection.


Assuntos
Rejeição de Enxerto/prevenção & controle , Imunoconjugados , Ativação Linfocitária , Linfócitos T/imunologia , Abatacepte , Animais , Antígenos CD , Antígenos de Diferenciação/fisiologia , Antígeno B7-1/fisiologia , Antígenos CD28/fisiologia , Antígeno CTLA-4 , Ciclosporina/uso terapêutico , Masculino , Reação em Cadeia da Polimerase , Ratos , Ratos Endogâmicos F344 , Ratos Endogâmicos Lew , Transplante Homólogo
16.
Protein Sci ; 1(7): 874-83, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1304372

RESUMO

Two enzymes involved in the biosynthesis of the trypanosomatid-specific dithiol trypanothione-glutathionylspermidine (Gsp) synthetase and trypanothione (TSH) synthetase--have been identified and purified individually from Crithidia fasciculata. The Gsp synthetase has been purified 93-fold and the TSH synthetase 52-fold to apparent homogeneity from a single DEAE fraction that contained both activities. This constitutes the first indication that the enzymatic conversion of two glutathione molecules and one spermidine to the N1,N8-bis(glutathionyl)spermidine (TSH) occurs in two discrete enzymatic steps. Gsp synthetase, which has a kcat of 600/min, shows no detectable TSH synthetase activity, whereas TSH synthetase does not make any detectable Gsp and has a kcat of 75/min. The 90-kDa Gsp synthetase and 82-kDa TSH synthetase are separable on phenyl Superose and remain separated on gel filtration columns in high salt (0.8 M NaCl). Active complexes can be formed under low to moderate salt conditions (0.0-0.15 M NaCl), consistent with a functional complex in vivo.


Assuntos
Amida Sintases , Crithidia fasciculata/enzimologia , Ligases/isolamento & purificação , Animais , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Cinética , Ligases/metabolismo , Peso Molecular
17.
Protein Sci ; 1(8): 970-9, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1304385

RESUMO

A Crithidia fasciculata 83-kDa protein purified during a separate study of C. fasciculata trypanothione synthetase was shown to have ATPase activity and to belong to the hsp90 family of stress proteins. Because no ATPase activity has previously been reported for the hsp90 class, ATP utilization by C. fasciculata hsp83 was characterized: this hsp83 has an ATPase kcat of 150 min-1 and a Km of 60 microM, whereas the homologous mammalian hsp90 binds ATP but has no ATPase activity. Crithidia fasciculata hsp83 undergoes autophosphorylation on serine and threonine at a rate constant of 3.3 x 10(-3) min-1. Similar analysis was performed on recombinant Trypanosoma cruzi hsp83, and comparable ATPase parameters were obtained (kcat = 100 min-1, Km = 80 microM, kautophosphorylation = 6.3 x 10(-3) min-1). The phosphoenzyme is neither on the ATPase hydrolytic pathway nor does it affect ATPase catalytic efficiency. Both C. fasciculata and T. cruzi hsp83 show up to fivefold stimulation of ATPase activity by peptides of 6-24 amino acids.


Assuntos
Adenosina Trifosfatases/metabolismo , Crithidia fasciculata/enzimologia , Proteínas de Choque Térmico/metabolismo , Trypanosoma cruzi/enzimologia , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/isolamento & purificação , Sequência de Aminoácidos , Animais , Sequência de Bases , Cromatografia por Troca Iônica , Crithidia fasciculata/genética , DNA de Protozoário/genética , DNA de Protozoário/isolamento & purificação , Drosophila/genética , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/isolamento & purificação , Humanos , Cinética , Camundongos , Dados de Sequência Molecular , Peso Molecular , Oligodesoxirribonucleotídeos , Fragmentos de Peptídeos/isolamento & purificação , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Homologia de Sequência de Aminoácidos , Trypanosoma cruzi/genética
18.
Transplantation ; 62(9): 1363-6, 1996 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-8932288

RESUMO

Although the immunosuppressive agents used clinically modulate acute rejection of organ allografts, their ability to prevent chronic rejection has been less clear. To ascertain the effects of prolonged maintenance treatment with cyclosporine (CsA) and mycophenolate mofetil, we examined sequential patterns of cytokine regulation by reverse transcriptase polymerase chain reaction in long-surviving renal allografts in treated recipients. In renal allografts in animals on long-term CsA therapy, there is important up-regulation of transforming growth factor-beta, Hsp70, and endothelin as compared with control animals. Conversely, interleukin-2 receptor, interferon-gamma, and tumor necrosis factor-alpha in kidney grafts in this group were expressed at lower levels compared with those noted in chronically rejecting grafts in control animals that had received only CsA for 10 days after transplantation. Morphologically, the long-term CsA-treated kidneys had more extensive arterial obliterative changes and glomerulosclerosis after 24 weeks than control organs; these changes can presumably be attributed to the nephrotoxic effects of this drug combined with the progressive changes of chronic rejection. In contrast, mycophenolate mofetil inhibited the production of all lymphocyte and macrophage-derived cytokines throughout the entire follow-up period. Allograft kidneys in these latter recipients showed no late morphological abnormalities. This agent may be important clinically in preventing chronic rejection.


Assuntos
Ciclosporina/administração & dosagem , Citocinas/biossíntese , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Imunossupressores/administração & dosagem , Transplante de Rim , Ácido Micofenólico/análogos & derivados , Animais , Citocinas/imunologia , Rejeição de Enxerto/imunologia , Masculino , Ácido Micofenólico/administração & dosagem , Ratos , Ratos Endogâmicos , Transplante Homólogo
19.
Transplantation ; 60(12): 1577-82, 1995 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-8545893

RESUMO

Chronic rejection is the primary cause of long-term allograft loss. Macrophages and their products have been shown to be critical in the development of this process in an established kidney allograft rat model. A new synthetic agent, Gamma lactone, is a specific inhibitor of macrophages and monocytes that inhibits the generation of these populations in vitro and their activities in the effector phase of host alloresponsiveness. We tested its effects on the development of chronic changes in the model. Untreated control allograft recipients developed increasing proteinuria after 12 weeks; progressive glomerulosclerosis, interstitial fibrosis, and arterial obliteration developed thereafter. Infiltrating ED1+ macrophages as noted by immunohistology increased dramatically between 12 and 16 weeks, localizing preferentially in glomeruli and perivascular areas. The presence of these cells was associated with dense expression of their products. Reverse transcription polymerase chain reaction confirmed and expanded the immunohistological findings, showing significant gene expression of macrophage-derived mediators. In contrast, recipients treated with G-Lac daily for 32 weeks never developed proteinuria; macrophage infiltration was dramatically reduced, and expression of their products was virtually absent. At 32 weeks, most glomeruli and arteries remained histologically normal. In another group in which treatment was stopped at 24 weeks, however, proteinuria began to develop by 32 weeks; macrophages infiltrated the organs and expression of their products became manifest. These results confirm the importance of macrophages and macrophage-derived factors in chronic rejection and suggest that a specific inhibitor of macrophage activation may be useful in the prevention of the process over the long term.


Assuntos
Furanos/uso terapêutico , Rejeição de Enxerto/prevenção & controle , Imunossupressores/uso terapêutico , Transplante de Rim , Macrófagos/efeitos dos fármacos , Animais , Rejeição de Enxerto/metabolismo , Rejeição de Enxerto/patologia , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Masculino , Ratos , Ratos Endogâmicos F344 , Ratos Endogâmicos Lew , Transplante Homólogo
20.
Transplantation ; 64(11): 1520-5, 1997 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9415550

RESUMO

BACKGROUND: Increasing clinical evidence suggests that delayed initial function secondary to ischemia/reperfusion injury alone, and particularly in combination with early episodes of acute rejection, reduces kidney allograft survival over time. METHODS: We investigated changes developing over the long term following a standardized ischemia/reperfusion insult in a Lewis rat model. The left kidney was isolated in a uninephrectomized host and cooled, and the pedicle was clamped for 45 min. Animals were followed for 48 weeks after initial renal injury. Organs were removed serially (4, 8, 16, 24, 32, 40, and 48 weeks) for immunohistology and reverse transcriptase polymerase chain reaction. RESULTS: Progressive proteinuria developed after 8 weeks. By immunohistology, CD4+ leukocytes and ED-1+ macrophages infiltrated the ischemic organs in parallel with up-regulation of major histocompatibility complex class II antigen expression. Because macrophages have been shown to be critical in chronic changes in other models, they were examined primarily in these studies. By reverse transcriptase polymerase chain reaction, macrophage-derived, fibrosis-inducing factors (transforming growth factor-beta, interleukin 6, and tumor necrosis factor-alpha) remained highly and constantly expressed throughout the follow-up period. The long-term influence of initial treatment with the soluble form of P-selectin glycoprotein ligand-1, a soluble ligand for P- and E-selectin, was then examined. All functional and structural changes remained at relative baseline, similar to uninephrectomized controls. CONCLUSIONS: These data suggest that blocking the initial selectin-mediated step after ischemia/reperfusion injury, which triggers significant early cellular and molecular events, also reduces later renal dysfunction and tissue damage over time. In part, the findings may be explained by the sparing of functioning nephron units, which if destroyed or compromised by the original insult, may contribute to long-term graft failure. This approach may be important clinically in the transplantation of kidneys from non-heart-beating or marginal donors or organs experiencing prolonged ischemic times.


Assuntos
Isquemia/patologia , Rim/irrigação sanguínea , Glicoproteínas de Membrana/metabolismo , Mucinas/metabolismo , Selectina-P/metabolismo , Traumatismo por Reperfusão/patologia , Animais , Quimiocina CCL2/biossíntese , Endotelina-1/biossíntese , Interleucina-6/biossíntese , Rim/patologia , Ligantes , Masculino , Reação em Cadeia da Polimerase , Proteinúria/patologia , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos Lew , Fator de Crescimento Transformador beta/biossíntese , Fator de Necrose Tumoral alfa/biossíntese
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