| Object 1) To test the reactive changes of normal nasal mucosa under photodynamic therapy(PDT) and damage of Photodynamic Therapy with different light dose on normal nasal mucosa,and for Photodynamic Therapy application for safe dose in the nasal. 2) To preliminarily investigate the therapeutic effect of Photodynamic Therapy(PT) treating Allergic Rhinitis(AR).Method 1) 24 New Zealand rabbits were randomly divided into 4 groups: normal control group “A”, 100 mw irradiation group “B”, 200 mw irradiation group “C”, 400 mwirradiation group “D”, each group 6 rabbits. Sampled nasal mucosa was toke separately from the same position of the rabbits from the 4 groups separately on 1st, 3rd, 7th, 14 th, 21 st, 28 th day. Histomorphology changes of the sampled nasal mucosa were observed using light microscope and transmission electron microscopy(TEM). The damage of three tachykinins: substance P(SP), neurokinin A(NKA) and neurokinin B(NKB) of nerve fibers are observed after immunohistochemical staining.2) 18 New Zealand rabbits were randomly divided into 3 groups: experimental group “A”, negative control group “B” and blank control group “C”. Rabbits of A and B groups were sensitized with Ovalbumin(OVA) to get animal AR model. Group A was treated with PDT while group B and group C were applied with natural light treatment. Symptoms and signs were compared before and after treatment and the change of nasal mucosa were observed with light microscope and transmission electron microscope. The damage of substance P(SP) of nerve fibers is observed after immunohistochemical staining.Results 1) Compared with the group A, the nasal mucosa tissues from the group B,C,D have seen seriously inflammation reaction with basal layer damaged on the 1st and 3rd day after PDT application, the epithelial cells of nasal mucosa were arranged in disorder, and part of cilium shortened and become abnormal or even disappeared, each organelles damaged obviously; on the 7th, 14 th, 21 st day, it can be see that ciliated cell, columnar cell and goblet cell start regenerate, basal cell and lamina propria glands proliferated, and the glands have seen secretion phenomenon; on the 28 th day, group B and C have found ciliated columnar epithelium took back the nasal mucosas with small amount of microvilli, and mucous granules were found in the column cells;At the same time, the group D have seen moderate inflammation reaction, the part of cilium shortened and disappeared, and does not appear obvious signs of recovery. Nasal immunohistochemical staining of the group B, C, D rabbits from various stages have shown that three kind of neuropeptides were not expressed.2) After PDT treatment, group A rabbits’ AR symptoms and signs were improved significantly compared to group B, light microscope and transmission electron microscope observation have shown that the number of inflammatory cells of group A rabbits decreased significantly and the mucosal structure returned to normal after PDT treatment. After 21 days, as compared with group C, the differences the times of sneezing and scratching and nasal secretion have no statistical significance(P>0.05). Nasal immunohistochemical staining of the experimental group rabbits from various stages have shown that SP were not expressed.Conclusions 1) When light dose between 100 mw and 100 mw, PDT application in the nasal is safety, Normal rabbit nasal mucosas will be temporarily damaged after PDT applied, the damaged nasal mucosas begin to recover in one week, and return to normal in about 4 weeks. Most structure and functions have recovered at the fourth week except some nerve endings. So it is reasonable to suggest that PDT can be used in AR treatment through proper control of light dose, the concentration of photosensitizer and the time of irradiation.2) PDT has certain therapeutic effect in experimental AR treatment, it is supposed that PDT can be used in AR treatment after consummating its therapeutic mechanism. |
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