Yoon-Kyung Sohn

TGF‐β‐induced protein βig‐h3 is upregulated by high glucose in vascular smooth muscle cells

TGF‐β‐induced gene‐h3 (βig‐h3) is an adhesive molecule that interacts with integrins. Because TGF‐β plays an important role in diabetic complications and βig‐h3 serves as a cell substrate, we hypothesized that diabetic conditions might increase βig‐h3 synthesis in vascular smooth muscle cells (VSMCs), which may subsequently contribute to the pathogenesis of diabetic angiopathy. The concentrations of βig‐h3 and TGF‐β were measured in conditioned media using an enzyme‐linked immunosorbent assay. An immunohistochemical study showed that βig‐h3 was expressed in the VSMCs and the matrix of rat aortas. TGF‐β stimulated βig‐h3 production, and high glucose induced βig‐h3 as well as TGF‐β production in the VSMCs. The high glucose‐induced βig‐h3 expression was almost entirely blocked by an anti‐TGF‐β antibody. βig‐h3 protein mediated the adhesion, spreading, migration, and proliferation of rat VSMCs. These results suggest that the high glucose‐induced βig‐h3 in VSMCs regulates VSMC functions and may play an important role in diabetic angiopathy.

A histopathologic study of the nervous system after inhalation exposure of 1-bromopropane in rat

1-Bromopropane (1-BP) has recently become known as an alternative cleaning material with less damage to the ozone layer. However, its toxicity is not fully evaluated. This study was designed to investigate the repeated inhalation toxicity of 1-BP on the nervous systems in Sprague-Dawley rats. The experiment was done by repeated exposure of the rats to 0, 200, 500, and 1250 ppm for 6 h per day, 5 days a week, for 13 weeks, respectively. Morphologic studies were done for the central nervous system, sacral and peroneal nerves. The serial sections of the brain and spinal cord of 1-BP inhalation groups revealed no pathological features either in the gray or white matter. The nerve fiber teasing, light and electron microscopic studies of the sacral and peroneal nerve fibers showed no significant difference between 1-BP inhalation groups and the control group. From these results, it is concluded that the nervous system is histologically resistant to the repeated inhalation of 1-BP up to 1250 ppm for 13 weeks. Experiments with higher concentrations of 1-BP and the functional studies are necessary to clarify the 1-BP toxicity.

The Role of Microsatellite Instability at Chromosome 11p15.5 in the Progression of Breast Ductal Carcinoma

The study of microsatellite instability (MSI) has provided the evidence to support asequential, progressive pathway for the development of cancer. In this study, we analyzed the role of MSI at chromosome 11p15.5 using microdissection of paraffin-embedded tissue from 68 matched normal and breast tumor samples. Components of intraductal, invasive and metastatic foci in lymph node were assessed for MSI using the polymorphic markers D11S922, tyrosine hydroxylase (TH) and D11S988. We found that MSI at D11S922 was relatively high incidence than other two markers and increased during breast cancer progression. The overall frequency of MSI at D11S922 was 26.7% in pure intraductal carcinoma, 36.4% in invasive carcinoma, and 40.0% in invasive carcinoma with metastases. We observed no significant correlation between MSI at chromosome 11p15.5 and the patients age, tumor size, histological grade, or lymph node metastasis. We compared the MSI incidence with the expression of prognostic markers, such as p53, c-erb B2, estrogen receptor, and progesterone receptor, and found no significant correlation. We suggest that the MSI of chromosome 11p15.5 is increased during breast cancer progression, but long-term follow-up study would establish whether MSI at chromosome 11p15.5 could be useful as a potential prognostic marker for breast cancer.