PURPOSE: Recent studies in an obstructive jaundice rat model showed that the bile duct epithelium is also very important in the bile duct dilatation besides the increased luminal pressure. This study evaluated the role of iNOS in the bile duct epithelium in a rat obstructive jaundice model. METHODS: Bile duct ligations were performed in male Sprague-Dawley rats. The bile ducts were harvested on seven consecutive days. Immunohistochemical staining in the bile duct was performed using anti-iNOS polyclonal antibodies. Aminoguanidine (an iNOS antagonist) was injected intraperitoneally after bile duct ligation (0, 100, and 200 mg/kg/day, n=6 in each group). One week after surgery, the diameter of bile duct was measured and bile was collected for NO analysis by 280NOA (Silvers). RESULTS: The iNOS expression level was increased in the dilated ductal epithelium after the bile duct ligation but not in the normal epithelium. Aminoguanidine decreased the mean diameter of the bile duct after the bile duct ligation: 11/-2.3 mm in the duct ligation only group; 7.5+/-0.75 mm in the 100 mg/kg/day aminoguanidine; 6+/-0.82 mm in the 200 mg/kg/day of aminoguanidine group (mean+/-SE, P<0.05). The NO concentration in the bile was decreased by aminoguanidine: 16+/-4.2 mM in the sham operation group; 40+/-4.5 mM in duct ligation only group; 34+/-6.4 mM in the 100 mg/kg/day of aminoguanidine group; 11+/-1.2 mM in the 200 mg/kg/day of aminoguanidine group (mean+/-SE). CONCLUSION: Bile duct ligation induced iNOS expression in the dilated bile duct epithelium and the iNOS antagonist partially inhibited bile duct dilatation. iNOS induction in the epithelium is partly responsible for the dilatation of the bile duct after duct ligation.
Animals ; Antibodies ; Bile Ducts* ; Bile* ; Dilatation ; Epithelial Cells* ; Epithelium ; Humans ; Jaundice, Obstructive ; Ligation* ; Male ; Models, Animal ; Nitric Oxide Synthase Type II* ; Phenobarbital ; Rats ; Rats, Sprague-Dawley

Background: Chondroblastomas, which account for approximately 1% of all bone tumors, typically occur in long bones, such as the femur, humerus, and tibia. However, in extremely rare cases, they may also occur in the craniofacial region where the tumor is often found in the squamous portion of the temporomandibular joint (TMJ) and in the temporal bone.Case presentation: This case report describes a large chondroblastoma (diameter, approximately 37 mm) that occurred in the TMJ. The tumor was sufficiently aggressive to destroy the TMJ, mandibular condyle neck, external auditory canal (EAC), mandibular fossa of the temporal bone, and facial nerve. The tumor was completely excised using a pre-auricular approach. The EAC and surgical defect were successfully reconstructed using a temporoparietal fascia flap (TPFF) and an inguinal free fat graft. There was no local tumor recurrence at the 18-month follow-up visits. However, the patient developed sensory neural hearing loss, and his eyebrow paralysis worsened, eventually requiring plastic surgery. Conclusion Large, invasive chondroblastomas of the TMJ can be completely removed through a pre-auricular approach, and the resulting surgical defect can be reconstructed using TPFF and free fat grafts. However, preoperative evaluation of the facial nerve and auditory function is necessary. Therefore, a multidisciplinary approach is essential.

Background: The pedicled buccal fat pad has been used for a long time to reconstruct oral defects due to its ease of flap formation and few complications. Many cases related to reconstruction of defects in the maxilla, such as closing the oroantral fistula, have been reported, but cases related to the reconstruction of defects in the mandible are limited. Under adequate anterior traction, pedicled buccal fat pad can be a reliable and effective method for reconstruction of surgical defects in the posterior mandible.Case presentation: This study describes two cases of reconstruction of surgical oral defects in the posterior mandible, all of which were covered by a pedicled buccal fat pad. The size of the flap was sufficient to perfectly close the defect without any tension. Photographic and radiologic imaging showed successful closure of the defects and no problems were noted in the treated area. Conclusion In conclusion, the pedicled buccal fat pad graft is a convenient and reliable method for the reconstruction of surgical defects on the posterior mandible.