The Study Of Therapeutic Mechanism Of Glucocorticoid By Injection Into Sternocleidomastoid Muscle In CMT

[Object] To investigate therapeutic mechanism of glucocorticoid by injection into sternocleidomastod muscle in the Congenital Muscular Torticollis (SMT) of infants.[Methods]Part of experiment in vitro1. The skeletal muscular interstitial fibroblasts (SMIFs) and myoblasts of the Wistar neonatal rats were isolated and cultured by the method of trypsin and collagenase digestion. These kinds of cells were identitied with light microscope and electron microscope examination and immunohistochemical observation.2. DNA synthesis of SMIFs were measured by 3H-TdR incorporation. The SMIFs number was estimated by MTT assay. Flow cytometry technique was adopted to observe the cell cycle. Collagen proteins were detecded by immunochemical stain to study the effect of desamethasone on the collagen express of the SMIFs. the apoptosis of the Cell apoptosis was detected by Tunel method and electron microscopy.3. The proliferaton of myoblasts was estimated by MTT assay and the differentiation of myoblasts was studied by light microscopy, Giemsa stain and detecton of creatine kinase (CK) to study the effect of desamethasone on the proliferation and differentiation of the myoblasts.4. The differentiation of myoblasts mixed with fibroblasts was studied by the above methods to investigate the effect of fibroblasts on the differentiation of myoblasts and the effect of dexamethasone on the myoblast diterentiation after inhabiting the effect of fibroblasts.Part of clinical study72 cases of SMT with mass by injection of glucocorticoid were followed up by ultrasonography for average of 6 months. The images of the size of SCM were studied. We compare the difference of these images before and after injection of glucocoticoid. We also compare the difference of the injection group with of the group only by manual treatment.[Results]1. Desamethasone may inhibit DNA synthesis of the fibroblasts and decrease the proliferation number and the proliferation index of the fibroblasts. These effects were in a concentration- dependent manner.2. Desamethasone (10-6mol/L) may inhibit collagen I and III expression of fibroblast.3. Desamethasone my increase the apoptotic rate of fibroblasts in dose-dependent manner. Under electronic microscope, apoptotic bodies of fibroblasts were found.4. In the concentration of 10-9-10-smol/L, Desamethason may not have the effect on the differentiation of myoblasts. The confusion rate of myoblasts and the activation of creatine kinase of myoblasts were not effected by desamethasone as compared control group.5. The differentiation of myoblast in mixed culture The confusion rate and the activation of myoblasts were decreased in mixed culture as compared to the pure myoblast culture.6. In mixed culture, desamethasone may increase the confusion rate and activation of myoblast as compared to the control group, but the confusion rate and activation of myoblasts in mixed group were smaller than the pure myoblast culture group.7. The results of ultrasonography1) There were no difference of the transverse diameter between the affected side and the normal side at the time of the followed-up. But the sagital diameter of the affected side was larger.2) At the time of the followed-up, the number of the same echoic image with the normal side was increased. The number of the cases of the strong echoic image was decreased. No cases with hypoehoic image were found.3) When compared with the result of the cases only by manual treatment, the number of hyperechoic cases was deseased in the drug injection group. The number of the cases of mixed echoic image was increased and the cases of the same echoic image with normal side was also increased in the injection group.[Conclusion]In vitro, desamethasone may inhibit the proliferation of the SMIFs, increase the apoptotic rate of the SMLFs, and decrease the collage I and III expression of the SMFs, In the same condition, desamethasone had no effect on the proliferation and differentiation of the myoblast. But...