Tetsuya Murakawa

Expression of KIT, EGFR, HER-2 and tyrosine phosphorylation in undifferentiated thyroid carcinoma: Implication for a new therapeutic approach

The KIT, epidermal growth factor receptor (EGFR) and HER‐2 oncoproteins have tyrosine kinase activity and are molecular targets in human cancer therapy. To clarify the significance of KIT, EGFR, and HER‐2 in undifferentiated thyroid carcinoma (UTC), the expression of these receptors and tyrosine phosphorylation was examined immunohistochemically in resected cases of UTC and papillary thyroid carcinoma (PTC). KIT, EGFR, and HER‐2 were also examined at the protein and mRNA levels in five UTC cell lines. KIT expression (1+), EGFR overexpression (2+/3+), HER‐2 expression (1+), and tyrosine phosphorylation were detected immunohistochemically in 40%, 70%, 10%, and 50% of the 10 UTC. In 20 PTC, KIT, EGFR, and HER‐2 were not detected, but tyrosine phosphorylation was detected in 25% of cases. In the five UTC cell lines, KIT expression (1+), EGFR overexpression (3+), HER‐2 expression (1+), and tyrosine phosphorylation were detected immunocytochemically in 60%, 100%, 20%, and 40%, respectively. Western blot analysis did not detect KIT expression, but did detect EGFR and HER‐2 expression in all five cell lines. Real‐time polymerase chain reaction detected KIT mRNA in two of the cell lines (40%), EGFR in five (100%), and HER‐2 in three (60%). The present findings suggest that EGFR overexpression was involved in the proliferation and development of UTC and was frequently accompanied by tyrosine phosphorylation. Expression of KIT and HER‐2 appeared to be weak but significant, suggesting a possible role in the development of UTC. Molecular therapies targeting KIT, EGFR, HER‐2, and/or tyrosine phosphorylation might be indicated for UTC.

A Case of Bilateral Laryngeal Nerve Paralysis after Endotracheal Intubation

Tetsuya Tanabe, Tetsuya Murakawa, Shiho Katoh, Etsuyo Tamura, Naoyuki Kohno and Satoshi Kitahara A 58-year-old woman with diffuse goiter underwent an expansive laminectomy of the spinal canal under general anesthesia in the prone and head down position. Her trachea was intubated uneventfully with a spiral tube (7.0-mm I.D.), and the cuff was filled with air (3 ml). It took 2 hours and 40 minutes to finish the surgical procedure. After extubation, stridor was noticed. Flexible laryngoscopic examination revealed stenosis of the glottis caused by bilateral laryngeal nerve paralysis, and a tracheotomy was performed. The paralysis disappeared within two weeks and the tracheal stoma was closed. The cause of the laryngeal nerve paralysis after endotracheal intubation is usually considered to be a local circulatory disorder produced by the endotracheal tube and cuff. In this case, however, the patient with diffuse goiter condition and the head down position may have been causes of the paralysis, because the other possible factors were negligible.