RESUMO
Objective To investigate the diagnostic value of MR diffusion tensor imaging (DTI) and diffusion tensor fiber bundle imaging (DTT) in white matter injury of cerebral infarction in different periods, and to observe the damage of white matter fiber bundles. Methods Four adult male rhesus monkeys, aging 8. 0 ± 1. 5 years old and weighted 9. 6 ± 1. 2 kg were experimented. Middle cerebral artery (Ml segment) embolization-reperfusion model was prepared by rhesus monkey autologous thrombosis and recanalization with recombinant tissue plasminogen activator 2. 5 h after embolization. Routine magnetic resonance imaging (MRI), diffusion weighted imaging (DWI) and DTI were performed at 4 h, 7 d and 30 d after surgery, respectively. The anisotropic coefficient (FA) values and changes of the white matter fiber bundles in corresponding parts of cerebral white matter between the infarcted side and the healthy side were compared. Results FA and the number of fiber bundles in the infarct side showed a trend of decrease on day 7 and increase on day 30 after ischemia, and the difference was statistically significant (At 4 h, 7 d and 30 d after cerebral ischemia, FA was 0. 301 ± 0. 045, 0. 200 ± 0. 050 and 0. 305 ± 0. 026, respectively: The number of fiber bundles was 43. 0 ± 1. 6, 22. 8 ±11.0 and 31.3 ± 6. 4, respectively. F values were 8. 223 and 7. 861, respectively; all P 0. 05). Conclusion DTI and DTT can better evaluate the degree of white matter fiber bundle injury in cerebral infarction at different stages, which is of great value in guiding clinical diagnosis and predicting prognosis.
RESUMO
Objective:To prepare Dermatophagoides farinae (Der f) crude protein to establish BALB/c bronchial asthma model , and to observe the morphology and degranulation of mast cells and detect related cytokines .Methods: Dermatophagoides farinae ( Der f) crude protein were prepared by trituration .30 BALB/c mice were randomly divided into 3 groups:PBS control group (A), asthma model group (B) and Der f crude protein treatment group (C).Group A were treated with PBS(100 μl) all the time, group B and group C were treated with 50 μg Der f crude protein mixed with 50μl alum adjuvant on day 0,day 7 and day 14.On day 28 group A and B were subcutaneous injected with PBS (100 μl) and group C were subcutaneous injected with Der f crude protein (350μg) in PBS(100 μl) at 1-day intervals.One week after the last treatment ,group A,B and C were intranasally challenged with 50 μg Der f crude protein daily for seven days .Twenty-four hours after the last challenge , airway hyper-responsiveness ( AHR) was assessed by using whole-body plethysmography .Two days post challenged , mice were sacrificed and bronchoalveolar lavage fluid ( BALF) was collected.Number of the total cells and eosinophil was determined .Level of IL-4,IL-10 and IFN-γcytokines in the BALF and the su-pernatant of splenocyte culture was assayed by ELISA .Level of Der f specific IgE and histamine in the sera was determined by ELISA . Airway inflammation was analyzed by HE staining .Observation of the morphology and degranulation of mast cells was analyzed by tolui -dine blue staining.Results:Compared with group B,AHR and the lung inflammation in group C were greatly reduced (P<0.01). Numbers of total cells and eosinophils in BALF of group C were significantly lower than that of group B ( P<0.01 ) .Compared with group B, the observation of degranulation of mast cells was insignificant in group C .Compared with group B(IgE:1.905), the level of specific IgE was significantly lower in groups C (IgE:1.278)(P<0.01).The level of IL-4 in BALF of group C was significantly lower than that of group B(P<0.01).Compared with group A and B, the level of IL-10 in BALF was significantly higher in group C (P<0.01) and the level of IFN-γin BALF of group C was significantly higher than that of group A and B (P<0.01).Compared with group B, the level of IL-4 in cultured splenocytes was significantly lower in group C (P<0.01), and the level of IL-10 and IFN-γin cultured splenocytes of group C was significantly higher than that of group B (P<0.01).Compared with group B, the level of histamine in BALF was slightly lower in groups C (P<0.05), and the level of histamine in sera was significantly lower in groups C (P<0.05). Conclusion:The degranulation of mast cells of murine bronchial asthma model was suppressed after the desensitization therapy .