Kiyoshi Udagawa

Wnt10a Is Involved in AER Formation During Chick Limb Development

The apical ectodermal ridge (AER) is indispensable for vertebrate limb development and requires Wnt/β‐catenin signaling for induction and maintenance. We report identification and involvement of Wnt10a in AER formation during chick limb development. Chicken Wnt10a has 82% identity with mouse Wnt10a in the amino acid sequence. The Wnt10a gene was expressed broadly in the surface ectoderm from as early as stage 10. By stage 15, the expression was restricted to the surface ectoderm overlying the lateral plate mesoderm. Wnt10a expression became intensified in the presumptive limb ectoderm during AER formation, and subsequently intense expression signals persisted in the AER. Wnt10a misexpression led to ectopic Fgf8 expression in the developing limb ectoderm and induced translocation of β‐catenin in chick embryo fibroblasts. These results suggest that Wnt10a is involved in AER formation in the chick limb bud through the Wnt/β‐catenin signaling pathway. Developmental Dynamics 233:282–287, 2005.

Changes of expression level of the differentiation markers in papillary thyroid carcinoma under thyrotropin suppression therapy in vivo immunohistochemical detection of thyroglobulin, thyroid peroxidase, and thyrotropin receptor

Differences in the expression levels of Thyroglobulin (Tg), Thyroid peroxidase (TPO) and thyrotropin receptor (TSH‐R) in primary and recurrent specimens under a suppressive serum TSH condition were elucidated in 26 papillary carcinoma patients.

Metastatic papillary thyroid carcinoma of the submandibular lymph nodes with extensive squamous metaplasia: report of a case.

We report a unique case of metastatic papillary thyroid carcinoma of the submandibular lymph nodes with extensive squamous metaplasia. A 48-year-old man was referred to our hospital for treatment of a thyroid tumor and right submandibular masses. A tumor, 2 cm in its largest dimension, was palpated in the right lobe of the thyroid gland. The masses in the submandibular region measured up to 3 cm in diameter. Each submandibular tumor had a cystic cavity containing slightly opaque fluid. Aspiration cytology of the thyroid established a diagnosis of papillary carcinoma. Aspirated material from the cystic cavity of one of the submandibular masses contained only keratinized material with a thyroglobulin level of 175 ng/ml. The patient underwent a total thyroidectomy with modified radical neck dissection. Microscopic examination of the resected specimen confirmed a diagnosis of papillary carcinoma of the thyroid, as well as well-differentiated squamous cell carcinoma with cystic changes in the submandibular lymph nodes. Focal immunoreactivity for thyroglobulin, combined with the absence of any other possible primary lesions in the head and neck region, suggested metastatic papillary thyroid carcinoma of the submandibular lymph nodes with extensive squamous metaplasia.