RESUMEN
BACKGROUND: Genetic modification of allergenic foods such as apple has the potential to reduce their clinical allergenicity, but this has never been studied by oral challenges in allergic individuals. METHODS: We performed oral food challenges in 21 apple-allergic individuals with Elstar apples which had undergone gene silencing of the major allergen of apple, Mal d 1, by RNA interference. Downregulation of Mal d 1 gene expression in the apples was verified by qRT-PCR. Clinical responses to the genetically modified apples were compared to those seen with the wild-type Elstar using a visual analogue scale (VAS). RESULTS: Gene silencing produced two genetically modified apple lines expressing Mal d 1.02 and other Mal d 1 gene mRNA levels which were extensively downregulated, that is only 0.1-16.4% (e-DR1) and 0.2-9.9% (e-DR2) of those of the wild-type Elstar, respectively. Challenges with these downregulated apple lines produced significantly less intense maximal symptoms to the first dose (Vmax1) than with Elstar (Vmax1 Elstar 3.0 mm vs 0.0 mm for e-DR1, P = 0.017 and 0.0 mm for e-DR2, P = 0.043), as well as significantly less intense mean symptoms per dose (meanV/d) than with Elstar (meanV/d Elstar 2.2 mm vs 0.2 mm for e-DR1, P = 0.017 and 0.0 mm for e-DR2, P = 0.043). Only one subject (5%) remained symptom-free when challenged with the Elstar apple, whereas 43% did so with e-DR1 and 63% with e-DR2. CONCLUSION: These data show that mRNA silencing of Mal d 1 results in a marked reduction of Mal d 1 gene expression in the fruit and reduction of symptoms when these apples are ingested by allergic subjects. Approximately half of the subjects developed no symptoms whatsoever, and virtually all subjects wished to consume the apple again in the future.
Asunto(s)
Antígenos de Plantas/genética , Antígenos de Plantas/inmunología , Hipersensibilidad a los Alimentos/inmunología , Silenciador del Gen , Malus/efectos adversos , Malus/genética , Proteínas de Plantas/genética , Proteínas de Plantas/inmunología , Adulto , Regulación hacia Abajo , Femenino , Hipersensibilidad a los Alimentos/diagnóstico , Hipersensibilidad a los Alimentos/prevención & control , Expresión Génica , Humanos , Masculino , Plantas Modificadas Genéticamente , Adulto JovenRESUMEN
From March 1990 to July 1991, 110 patients (44 males, 66 females; mean age 54.44 +/- 8.8 years) underwent hearth valve replacement with a CarboMedics bileaflet prosthesis (CarboMedics Inc, Texas, USA). Preoperative pathophysiologic conditions were: aortic stenosis in 32 patients, aortic regurgitation in 22 patients; mitral stenosis in 27 patients and mitral regurgitation in 14 patients. Mitroaortic disease was present in 14 patients but 1 had triple valve disease. NYHA class was III or IV in 91 patients (83%). Operative mortality rate was 0.91% (1 patients). Actuarial survival rate is 95% at 58 months. Actuarial freedom from thromboembolic events in 95% at 58 months. Actuarial freedom from hemorrhage is 100%. Endocarditis befell in 2 patients; actuarial freedom from this complication at 58 months is 95%. Actuarial freedom from reoperation in 99%. We conclude that the low incidence of valve related events and the low mortality supports the use of the bileaflet valve CarboMedics.