Expression of TGFbeta Family in the Developing Internal Ear of Rat Embryos

In order to investigate the expression patterns of the transforming growth factor (TGF)beta isoforms in the internal ear, an immunohistochemical study of rat embryos was performed. Rat embryos were taken on the 13th, 15th, 17th, and 19th day after conception and their internal ears were immunohistochemically stained against TGF beta1, beta2, and beta3. As a result, the 13-day-old embryo showed a very weak positivity to TGF beta1. After the 15th day of pregnancy, no reactivity to TGF beta1 was defected. Immunoreactivity to TGF beta2 was observed from the 15th day of pregnancy throughout the rest of the period. The ampulla of the semicircular canal and the cochlear duct showed a notably strong immunohistochemical reaction. A strong reaction to TGF beta3 was observed on the 15th day of pregnancy. However, no positive reactions were observed thereafter. A strong immunoreactivity was observed especially on the apical cytoplasms, the surfaces of the epithelial cells, and basement membranes of the cochlear duct, as well as the semicircular canals of the developing internal ear of rat embryo.

A Case of Bilateral Bridges of a Korean Atlas / 체질인류학회지

We report a case of bilateral bridges of atlas of a Korean atlas and accompanying variation of the course of the left suboccipital nerve that was observed during the practice of the human anatomy in Seonam university, college of medicine. Bridges of atlas across the groove for the vertebral artery run inferomedially from the posterior margins of the superior articular processes to the posterior margins of the grooves. Widths of the narrowest middle portions of the bridges are 5.05 mm at the left and 0.7 mm at the right. Superior and inferior widths of left bridge are 11.6 mm and 10.9 mm, and of the right are 4.45 mm and 4.65 mm respectively. Cross-sectional areas of the foramina formed by bridges of atlas are 34.7 mm 2 at the left and 29.3 mm 2 at the right. These sizes are much smaller than the sizes of the transverse foramina of the atlas at each side, but diameters of the second and third portions of the left vertebral artery are same as 4.3 mm. At the junction between the left bridge and the posterior arch distinct suture line was observed. Because of the relatively wide bridge, the left suboccipital nerve runs more laterally than the right. It turns to the posterior, pierces the obliquus capitis inferior muscle, and branches out to adjacent suboccipital muscles. Branch to the rectus capitis posterior muscles obliquely cross over the suboccipital triangle to these muscles.

Expression of the TGF-beta Family during the Development of Rat Eye / 대한해부학회지

The development of eye is a very dynamic process in which various cells and tissues from diverse originneuroectoderm, surface ectoderm and mesenchyme, undergo induction, mitosis and differentiation. During this process advances, many growth factors are involved. Transforming growth factor betas (TGF-betas) are the pivotal growth factors during cellular growth, differentiation, matrix formation, migration and wound healing. Especially during the development of tissues, TGF-beta s are secreted and induce growth and differentiation of adjacent cells. To investigate the functions of TGF-betas during the development of eye, we studied the expression of TGF-betas in rat embryos. For this study, Sprague-Dawley rat embryos were taken on the 11th 13th, 15th, 17th and 19th day of gestation. To confirm the morphological changes of eyes on each developmental stage, sections were stained with hematoxylin and eosin. Then, to document the expressive patterns of TGF-beta1, beta2, beta3 and TGF-beta receptor type II (TbetaR), immunohistochemistry was applied. The results were obtained as follows: TGF-beta1 was partially expressed in the lens only on the 19th day of gestation. TGF-beta2 was expressed in the retina and lens on the 11th and 13th day, while it was detected in most areas of the eye from the 15th to 19th day. TGF-beta3 was expressed only in the pigment cell layer of the retina on the 11th day, but it was detected in various areas along the advance of the development. Immunoreactivity of TGF-beta3 was always weaker than TGF-beta2. TbetaR showed strong immunoreactivity in where the reactivity of TGF-beta2 was detected. These results indicate that TGF-beta2 and beta3 play important roles during the development of eye.