OBJECTIVE: To explore the use of β-lactoglobulin polymerized using microbial transglutaminase and heating to identify whether protein polymerization could reduce in vivo allergenicity and maintain in vitro and ex vivo immunoreactivity for use in tolerance-induction protocols. METHODS: Based on previous protocols applied in mice and children, we performed in vivo challenges (using a skin prick test) with native and polymerized β-lactoglobulin in adult patients with an IgE-mediated allergy to plactoglobulin. In vitro humoral immunoreactivity was analyzed using immunoblotting. Cell-mediated immunoreactivity was analyzed using ex vivo challenges with native and polymerized β-lactoglobulin and monitored by leukocyte adherence inhibition tests. RESULTS: The skin tests demonstrated that there was a significant reduction in immediate cutaneous reactivity after polymerization. Polymerization did not decrease the immunoblotting detection of s-IgE specific to β-lactoglobulin. Cell-mediated immunoreactivity, as assessed by ex vivo challenges and leukocyte adherence inhibition tests, did not exhibit significant differences between leukocytes challenged with native versus polymerized β-lactoglobulin. CONCLUSIONS: The polymerization of β-lactoglobulin decreased in vivo allergenicity and did not decrease in vitro humoral or ex vivo cell-mediated immunoreactivity. Therefore, we conclude that inducing polymerization using transglutaminase represents a promising technique to produce suitable molecules for the purpose of designing oral/ sublingual tolerance induction protocols for the treatment of allergies.

Ainda existem controvérsias quanto a possíveis diferenças de esvaziamento gástrico entre os sexos. Os objetivos deste estudo são: confirmar se homens e mulheres realmente diferem no esvaziamento gástrico de uma dieta sólida e investigar se esta diferença está relacionada com diferentes padrões de distribuição da dieta entre os compartimentos proximal e distal do estômago. Dezoito voluntários assintomáticos (nove do sexo masculino, com idade média de 35 ± 9 anos e nove do sexo feminino, com idade média de 41 ± 11 anos) foram estudados pela manhã, após ingestão da dieta sólida padronizada (omelete marcada com 185MBq de enxofre coloidal-99mTc). Imagens simultâneas do estômago nas projeções anterior e posterior foram adquiridas imediatamente após a ingestão da dieta e a cada 10 minutos, durante 120 minutos. Curvas de tempo versus contagem radioativa foram obtidas para o estômago total, proximal e distal. O T½ do esvaziamento gástrico foi maior para as mulheres (96,1 ± 17,2 minutos) do que para os homens (79,9 ± 17,8 minutos; P = 0,02). A análise da distribuição intragástrica da dieta mostrou que não houve diferenças entre os sexos quanto ao esvaziamento gástrico proximal, mas as mulheres apresentaram maior retenção da dieta na porção distal do estômago (P = 0,04). Nossos resultados mostram que o esvaziamento gástrico de sólidos é mais lento nas mulheres não-menopausadas assintomáticas, do que nos homens de faixa etária semelhante, provavelmente devido a maior retenção da dieta na região distal do estômago. Este fato deve ser levado em conta nos estudos de esvaziamento gástrico pela cintilografia para evitar diagnósticos errôneos de gastroparesias nas pacientes do sexo feminino.

Gender-related differences in gastric emptying are still controversial. The aims of this study were: to confirm the sex-related difference in gastric emptying of a solid meal and to investigate its association with different patterns of meal distribution between the proximal and distal gastric compartments. Eighteen healthy volunteers (nine males, mean age 35 ± 9 years; nine females, mean age: 41 ± 11 years) were studied in the morning, after ingestion of the solid test-meal (an omelette labeled with 185MBq of 99mTc-sulfur colloid). Simultaneous anterior and posterior images of the stomach were acquired immediately after ingestion of the meal and every 10 minutes for 120 minutes. Time versus activity curves were obtained for the whole, proximal and distal stomach. Gastric T½ was longer in women (96.1 ± 17.2 min) than in men (79.9 ± 17.8 min; P = 0.02). The analysis of the meal distribution inside the stomach showed no differences between males and females in proximal gastric emptying, but the meal retention in the distal compartment was significantly increased among women (P = 0.04). In conclusion, gastric emptying of a solid meal is slower in pre-menopausal women than in age-matched men, probably due to an increased retention of the meal in the distal compartment. This should be taken into consideration to avoid misleading diagnosis of gastroparesis for female patients.