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Purpose:This study evaluated powdered burn wound dressing materials from wild silkworm fibroin in an animal model.Methods:Fifteen rats were used in this experiment. Full-thickness 2×2 cm burn wounds were created on the back of rats under anesthesia. In the two experimental groups, the wounds were treated with two different dressing materials made from silkworm fibroin. In the Control Group, natural healing without any dressing material was set as control. The wound surface area was measured at five days, seven days and 14 days. Wound healing was evaluated by histologic analysis.Results:By gross observation, there were no infections or severe inflammations through 14 days post-injury. The differences among groups were statistically significant at seven days and 14 days, postoperatively (P <0.037 and 0.001, respectively). By post hoc test, the defect size was significantly smaller in experimental Group 1 compared with the Control Group and experimental Group 2 at seven days postoperatively (P =0.022 and 0.029, respectively). The difference between Group 1 and Group 2 was statistically significant at 14 days postoperatively (P <0.001). Group 1 and control also differed significantly (P =0.002). Group 1 showed a smaller residual scar than the Control Group and Group 2 at 14 days post-injury. Histologic analysis showed more re-epithelization in Groups 1 and 2 than in the Control Groups.Conclusion:Burn wound healing was accelerated with silk fibroin spun by wild silkworm Antheraea pernyi. There was no atypical inflammation with silk dressing materials. In conclusion, silk dressing materials can be used for treatment of burn wound.

Radiofrequency thermocoagulation has been used to treat chronic pain since the 1950s. The Tew electrode was developed as a flexible, curved electrode, virtually eliminating complication. Different temperatures and treatment durations were used to analyze the size and shape of lesions produced by the Tew electrode to facilitate the use of radiofrequency in chronic pain management.

A patient who complained of difficulty in opening his mouth after condylar neck fracture 1 year ago presented typical features of temporomandibular joint ankylosis in clinical and radiologic examinations. To demonstrate a possible pathogenesis of temporomandibular joint ankylosis after condylar neck fracture, the fractured condylar portion removed was examined by histologic and immunohistochemical stainings. Interpositional gap arthroplasty was performed by removing the inferomesially displaced fractured condyle, and reconstruction with subcutaneous dermis to the previous vertical height was performed immediately. The fractured condylar portion was almost intact with slight erosion of the condylar cartilage. In the hematoxylin and eosin and Masson trichrome stainings, an extensive chondroid hyperplasia with abundant hyaline cartilage was shown in the removed condylar portion. There were also hyperplastic features of the synovial membrane, which were abnormally distributed throughout the chondroid tissues. In the immunohistochemical stainings of proliferating cell nuclear antigen (PCNA) and bone morphogenetic protein (BMP)-2 and BMP-4, the chondroid tissues were conspicuously hyperplastic and strongly positive for BMP-4 but sparse for BMP-2. From these results, we think that the hyperplastic chondroid tissue was derived from the callus of the primary fractured site of the condylar neck and propose that the chondroid tissue could proliferate continuously because of synovial tissue support from around the temporomandibular joint, resulting in temporomandibular joint ankylosis. This pathogenesis is quite different from those of other diaphyseal fracture of long bones.

Purpose:This study evaluated woven silk textile for burn wound dressing materials in an animal model.Methods:Ten rats were used in this experiment. Full-thickness 2×2 cm burn wounds were created on the back of the rats under anesthesia. In the experimental group, the wounds were treated with three different dressing materials from woven silk textile. In the control group, natural healing without any dressing material was set as control. The wound surface area was measured at five days, seven days, and 14 days. Wound healing was evaluated by histologic analysis.Results:There were no statistically significant differences among groups at five days post injury. The mean defect size at seven days was largest in Group 3 (462.87 mm2), and smallest in Group 1 (410.89 mm2), not a significant difference (P =0.341). The mean defect size at 14 days was smallest at the Group 3 (308.28 mm2) and largest in the control group (388.18 mm2), not a significant difference (P =0.190). The denuded area was smaller in Group 1 (84.57 mm2) and Group 2 (82.50 mm2) compared with the control group (195.93 mm2), not statistically significant differences (P =0.066, 0.062). The difference between Group 3 and control was also not statistically significant (P =0.136). In histologic analysis, the experimental groups re-epithelialized more than control groups. No evidence was found of severe inflammation.Conclusion:The healing of burn wounds was faster with silk weave textile more than the control group. There was no atypical inflammation with silk dressing materials. In conclusion, silk dressing materials could be used to treat burn wounds.