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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.

Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that plays an important role in tumor growth and metastasis by regulating energy metabolism and inducing angiogenesis. Elevated levels of HIF-1alpha, a subunit of HIF-1, are noted in various malignant tumors, but it is unclear whether this is so in esophageal carcinoma. The purpose of this study was to evaluate the implications of HIF-1alpha expression in esophageal squamous cell carcinoma. In 215 patients with esophageal carcinoma, we examined immunoreactivity for HIF-1alpha protein, vascular endothelial growth factor (VEGF) protein and p53 protein. In 38 patients, we examined the expression of HIF-1alpha messenger ribonucleic acid (mRNA) (using the semiquantitative reverse transcriptase-polymerase chain reaction [RT-PCR]). A positive HIF-1alpha protein expression was recognized in 95% of the patients, and was strongly apparent within both the nuclei and/or cytoplasm of tumor cells. The proportion of patients in the 'high score' group for HIF-1alpha protein expression increased significantly with increasing VEGF protein expression. Immunoreactivity for HIF-1alpha protein was found to have a significant effect on disease-free survival rate in our univariate analysis, but no effect on overall survival rate. In RT-PCR, HIF-1alpha mRNA scores correlated significantly with scores for HIF-1alpha protein expression, but not with any clinicopathologic factor or either of the survival rates. The detection of HIF-1alpha protein and mRNA would appear to offer limited information as to progression and prognosis in esophageal carcinoma.

Because of the progress in optical communication technology, understanding the propagation characteristic of optical fibers has become very important. In particular, since optical networks have been used widely, the evaluation of optical fibers in the field is essential. This paper describes the measurement of the chromatic dispersion of optical fibers and a system suitable for the measurement in the field. The approach is based on the baseband phase-comparison method. First, the conditions required for this measurement system will be clarified. Then the measurement of wavelengths and wavelength separation satisfying the requirements will be obtained by simulation. The source of each wavelength must be modulated. However, to increase the fiber length and to improve measurement precision, a modulation method based on multiple sinusoidal waves will be proposed, and the upper and lower limit of the optimum modulation frequency will be clarified. The measurement system will be constructed from these results. The technical problems in realizing the system will be shown. Finally, an example of data measured by the constructed system will be shown, and it will be demonstrated that a resolution of 0.01 ps/nm/km and measurement precision of ± 0.3 ps/nm/km can be achieved at wavelengths of 1.3 and 1.55 μm.