RESUMEN
BACKGROUND: Tyrophagus putrescentiae (Tp) is a source of aeroallergen that causes allergic diseases. OBJECTIVE: To describe an acute and chronic murine model of allergic asthma with Tp extract with no systemic sensitization and no use of adjuvant. METHODS: Mites from dust sample were cultured and a raw extract was produced. Female BALB/c mice (6-8 weeks) were challenged intranasally with Tp extract or Dulbecco's phosphate-buffered saline, for 10 consecutive days (acute protocol) or for 6 weeks (chronic protocol). Twenty-four hours after the last intranasal challenge, bronchoalveolar lavage fluid (BALF) was performed for total and differential cells count, cytokine analysis, and eosinophil peroxidase activity. Lung tissue was also removed for histopathologic analysis. RESULTS: Tp extract has shown a significant increase in total cells count from BALF as well as an increase in absolute eosinophils count, eosinophil peroxidase activity, interleukin (IL)-5 and IL-13 levels, in both acute and chronic protocols. Peribronchovascular infiltrate, goblet cells hyperplasia and collagen deposition were shown in the airways of acute and chronic Tp-exposed mice. CONCLUSION: Our data suggest that the intranasal exposure to Tp extract, with no systemic sensitization and no use of adjuvants, induces a robust allergic inflammation in the lungs of mice, in both acute and chronic models. Our Tp extract seems to be a potent allergen extract which may be used in asthma model studies.
RESUMEN
OBJETIVOS: Foram avaliados os efeitos do uso de células tronco da medula óssea (CTM) e do plasma rico em plaquetas (PRP) na regeneração de nervos periféricos, utilizando um modelo estabelecido de regeneração de nervo ciático em ratos. MÉTODOS: Um defeito nervoso de 10 mm foi reconstruído com a utilização de um tubo de silicone preenchido com CTM, PRP ou ambos. O grupo controle recebeu somente o tubo de silicone. Foi realizado ainda um quinto grupo no qual o intervalo foi reconstruído utilizando o segmento ressecado do nervo. A função motora foi testada seis semanas após a cirurgia utilizando teste de marcha. Após o teste motor, os ratos foram anestesiados, o nervo ciático e o tubo foram ressecados e foi realizada microscopia eletrônica de transmissão. RESULTADOS: A análise quantitativa demonstra uma melhora na recuperação funcional no grupo CTM em comparação com os demais grupos. Regeneração nervosa foi demonstrada no grupo CTM por microscopia eletrônica de trasmissão com uma recuperação praticamente completa da anatomia neural. CONCLUSÃO: Nossos resultados sugerem que o uso de CTM associado com a técnica de tubulização promove uma satisfatória recuperação da função motora e regeneração nervosa.
OBJECTIVES: The effects of the use of bone marrow stem cells (MSC) and platelet-rich plasma (PRP) on peripheral nerves regeneration were assessed by using an established model of sciatic nerve regeneration in rats. METHODS: A 10-mm nervous defect was reconstructed by using a silicone tube filled with MSC, PRP or both. The control group received only the silicone tube. A fifth group was also set, in which the interval was reconstructed by using a dried segment of the nerve. Motor function was tested six weeks after surgery, by means of a gait test. After motor test, the rats were anesthetized, the sciatic nerve and the tube were dried, and the transmission electronic microscopy was performed. RESULTS: The quantitative analysis shows an improved functional recovery in MSC group compared to the other groups. Nervous regeneration was reported for MSC group by means of transmission electronic microscopy with an almost full recovery of the neural anatomy. CONCLUSION: Our results suggest that the use of MSC combined with tubing technique yields a satisfactory recovery of motor function and nervous regeneration.