Motor Innervation of the Guinea Pig Interarytenoid Muscle: Reinnervation Process Following Unilateral Denervation

The authors investigated the process of denervation and reinnervation of the interarytenoid (IA) muscle in the guinea pig using transmission electron microscopy and glycogen depletion technique after unilateral transection of the recurrent laryngeal nerve (RLN) and superior laryngeal nerve to clarify the innervation pattern of the unpaired IA muscle. Anastomosis between the bilateral arytenoid branches was confirmed in the belly of the IA muscle. Five weeks after transection, all of the IA muscle fibers appeared to have been reinnervated by the contralateral RLN. As the arytenoid branch of the RLN runs together with that of the contralateral RLN in a single intramuscular nerve funiculus, it is possible that collateral sprouting branches grow and extend into the adjacent denervated Schwann's sheaths. The authors conclude that the unpaired IA muscle, as a whole, receives specific motor nerve supply from the bilateral RLNs, although each muscle fiber is innervated unilaterally.     

Tumor-specific Activation of Mitogen-activated Protein Kinase in Human Colorectal and Gastric Carcinoma Tissues

To search for the signaling events in colorectal carcinoma relevant to its tumorigenesis, we investigated the activity of mitogen-activated protein kinase (MAPK) in human colorectal carcinoma tissues and paired normal tissues. Of 64 cases examined, approximately 75% (48 cases) showed tumor-specific activation of MAPK by in situ kinase renaturation assay, as well as in vitro kinase assay with immunoprecipitated MAPK. In addition, tumor-specific activation of MAPK was associated with the activation of MAPK kinase in the cases we examined. However, no clear correlation of MAPK activation with lymph node involvement, metastatic rate, stage, histological classification, age or sex was observed. These results suggest that the MAPK pathway is involved in colorectal tumor development, but its activation alone is not sufficient for malignant conversion. In contrast to colorectal carcinoma, gastric carcinoma tissues showed a lower rate of MAPK activation, suggesting that the signaling pathway activated in colorectal carcinoma tissues may differ in part from that of gastric carcinoma.     

Dental management of unilateral multiple impacted primary teeth

Impacted primary teeth can be caused by odontogenic tumors such as odontomas, cystic diseases such as dentigerous and eruption cysts, and fibrous hyperplasia of the gingiva, while elimination of those causes reportedly results in normal eruption of primary teeth. We describe the course of a child from the age of 1 year until 4 years 10 months who had primary tooth eruption failure and was treated with dental methods. Although primary teeth expected to spontaneously erupt were followed, there were several on the left side that remained unerupted. We performed a left maxillary and mandibular gingivectomy to closely examine the cause of eruption delay and tooth germ dislocation, as well as attempt to induce eruption of the primary teeth. Based on histopathological results, the diagnosis was fibroma. Surgical procedures did not result in clear improvement of eruption failure. In order to improve masticatory function and aesthetics, the child was fixed with an artificial denture for all primary teeth not expected to erupt.     

Maximum Standard Uptake Value at the Biopsy Site during F-Fluorodeoxyglucose Positron Emission Tomography Does Not Predict the Proliferation Potential of Tumor Cells in Extranodal Natural Killer/T Cell Lymphoma, Nasal Type

No abstract available.