Development of Refolding Process to Obtain Active Recombinant Human Bone Morphogenetic Protein-2 and its Osteogenic Efficacy on Oral Stem Cells

BMP-2 is a well-known TGF-beta related growth factor, having a significant role in bone and cartilage formation. It has been employed to promote bone formation in some clinical trials, and to differentiate mesenchymal stem cells into osteoblasts. However, it is difficult to obtain this protein in its soluble and active form. hBMP-2 is expressed as an inclusion body in the bacterial system. To continuously supply hBMP-2 for research, we optimized the refolding of recombinant hBMP-2 expressed in E. coli, and established an efficient method by using detergent and alkali. Using a heparin column, the recombinant hBMP-2 was purified with the correct refolding. Although combinatorial refolding remarkably enhanced the solubility of the inclusion body, a higher yield of active dimer form of hBMP-2 was obtained from one-step refolding with detergent. The refolded recombinant hBMP-2 induced alkaline phosphatase activity in mouse myoblasts, at ED₅₀ of 300-480ng/ml. Furthermore, the expressions of osteogenic markers were upregulated in hPDLSCs and hDPSCs. Therefore, using the process described in this study, the refolded hBMP-2 might be cost-effectively useful for various differentiation experiments in a laboratory.

Indirect Co-Culture of Stem Cells from Human Exfoliated Deciduous Teeth and Oral Cells in a Microfluidic Platform

Oral epithelial-mesenchymal interactions play a key role in tooth development and assist differentiation of dental pulp. Many epithelial and mesenchymal factors in the microenvironment influence dental pulp stem cells to differentiate and regenerate. To investigate the interaction between oral cells during differentiation, we designed a microfluidic device system for indirect co-culture. The system has several advantages, such as consumption of low reagent volume, high-throughput treatment of reagents, and faster mineralization analysis. In this study, stem cells from human exfoliated deciduous teeth were treated with media cultured with human gingival fibroblasts or periodontal ligament stem cells. When human exfoliated deciduous teeth was incubated in media cultured in human gingival fibroblasts and human periodontal ligament stem cells under the concentration gradient constructed by the microfluidic system, no remarkable change in human exfoliated deciduous teeth mineralization efficiency was detected. However, osteoblast gene expression levels in human exfoliated deciduous teeth incubated with human gingival fibroblasts media decreased compared to those in human exfoliated deciduous teeth treated with human periodontal ligament stem cells media, suggesting that indirect co-culture of human exfoliated deciduous with human gingival fibroblasts may inhibit osteogenic cytodifferentiation. This microfluidic culture device allows a co-culture system set-up for sequential treatment with co-culture media and differentiation additives and facilitated the mineralization assay in a micro-culture scale.

Selective apoptotic effect of Zelkova serrata twig extract on mouth epidermoid carcinoma through p53 activation / 国际口腔科学杂志·英文版

Apoptosis or programmed cell death plays an essential role in chemotherapy-induced tumor cell killing, and inducers of apoptosis are commonly used in cancer therapy. Treatment with Zelkova serrata extracts was performed in human gingival fibroblast (HGF), mouth epidermoid carcinoma cell (KB), lower gingival squamous cancer cell (YD38) and tongue mucoepidermoid carcinoma cells (YD15). We observed that extract prepared from Zelkova serrata twig selectively inhibited proliferation of various oral cancer cells, but not normal gingival fibroblasts, in a dose-dependent manner. Caspase-8-mediated apoptosis was induced by treatment with the extract only in mouth epidermoid carcinoma and not in other types of cancer cells, including lower gingival squamous cell carcinoma. The selective apoptotic effect of Zelkova serrata twig extract in mouth epidermoid carcinoma was dependent on normal p53 status. Apoptosis was not remarkably induced by treatment with the extract in either lower gingival squamous or tongue mucoepidermoid carcinoma cells, both of which contain abnormalities of p53. Upon treatment with Zelkova serrata twig extract, mouth epidermoid carcinoma cells accumulated in S phase by activation of p21. These data indicate that Zelkova serrata twig extract exerted a cancer type-specific, p53-dependent apoptotic effect and disturbed the cell cycle, which suggests that herbal medicine could be a treatment for specific types of cancers.

Focal-Type Autoimmune Pancreatitis Mimicking Cholangiocarcinoma / 대한내과학회지

Autoimmune pancreatitis (AIP) is a rare pancreatic disorder of autoimmune etiology. It has characteristic clinical features, such as pancreatic parenchymal swelling and irregular narrowing of the main pancreatic duct due to plasma cell infiltration. It occurs mostly in Far East Asia. Although it generally involves whole pancreatic parenchyma, some cases demonstrate focal involvement of the pancreas or adjacent organs, which are often mistaken for cancer. We report a case of AIP that was confused with cholangiocarcinoma of the distal common bile duct (CBD). The patient experienced sudden development of jaundice with vague abdominal discomfort. Abdominal computed tomography revealed a well-enhanced lesion, and positron emission tomography showed high standard uptake value at the distal CBD, indicating malignant disease. However, pathological examination by surgical excision indicated focal-type AIP. This is believed to be the first case of focal-type AIP mimicking cholangiocarcinoma.

Cavernous Sinus Metastasis of Non-Small Cell Lung Cancer / 결핵및호흡기질환

Progressive ptosis and headache developed in a 50-year-old woman with non-small cell lung cancer. Although brain magnetic resonance imaging showed improved cerebellar metastasis after prior radiotherapy without any other abnormality, the follow-up examination taken 6 months later revealed metastasis to the cavernous sinus. The diagnosis of metastasis to the cavernous sinus is often difficult because it is a very rare manifestation of lung cancer, and symptoms can occur prior to developing a radiologically detectable lesion. Therefore, when a strong clinical suspicion of cavernous sinus metastasis exists, thorough neurologic examination and serial brain imaging should be followed up to avoid overlooking the lesion.

Reduced right-side lung volume on a chest radiograph / 대한내과학회지

No abstract available.

A bioactivity study of Portland cement mixed with beta-glycerophosphosphate on human pulp cell / 대한치과보존학회지

The purpose of this study is to investigate the response of human pulp cell on Portland cement mixed with beta-glycerophosphate. To investigate the effect of beta-glycerophosphate and/or dexamethasone on human pulp cell, ALP activity on various concentration of beta-glycerophosphate and dexamethasone was measured and mineral nodule of human pulp cell was stained with Alizarin red S. MTS assay and ALP activity of human pulp cell on Portland cement mixed with various concentration of beta-glycerophosphate (10 mM, 100mM, 1M) was measured and the specimens were examined under SEM. Addition of beta-glycerophosphate or dexamethasone alone had no effect however, the addition of 5 mM beta-glycerophosphate and 100 nM dexamethasone had the largest increasement in ALP activity. There was no toxicity in all samples and the data showed that Portland cement mixed with 10 mM beta-glycerophosphate had more increase in ALP activity compared with control. In conclusion, Portland cement mixed with beta-glycerophosphate has no toxicity and promotes differentiation and mineralization of pulp cell compared with additive-free Portland cement. This implicated that application of Portland cement mixed with beta-glycerophosphate might form more reparative dentin and in turn it would bring direct pulp capping to success.

A Case of Henoch-Schonlein Purpura Developed during Treatment of Lung Cancer / 결핵및호흡기질환

Henoch-Schonlein Purpura (HSP) is a systemic vasculitis involving small vessels with the deposition of immune complexes containing IgA and C3, which is characterized by associated skin, joint, renal, and gastrointestinal manifestations. Although there were several causes such as autoimmunity, infection, and drugs, it also can be presented as a form of vasculitidies associated with malignancies. We report a case of HSP developed during treatment for non-small cell lung cancer in a 66-year-old man. Multiple purpuric skin lesions occurred in both legs after the first cycle of chemotherapy, which was diagnosed as HSP by clinical and pathologic examinations. Due to the itching sensation, topical steroid was applied and the patient was improved 3 weeks later without a scheduled change in chemotherapy.

Newly Developed Weakness of Lower Extremities Despite Improved Brain Metastasis of Lung Cancer after Radiotherapy / 결핵및호흡기질환

An intramedullary spinal cord metastasis (ISCM) rarely develops in systemic cancer but is indicative of a poor prognosis. A 56-year-old man was admitted due to weakness of the lower extremities. He had received radiotherapy 3 months prior for a brain metastasis that had developed 1 year after achieving a complete response from chemotherapy for extended stage small cell lung cancer. Although the brain lesion had improved partially, ISCM from the cervical to lumbar-sacral spinal cords, which was accompanied by a leptomeningeal dissemination, was diagnosed based on magnetic resonance imaging of the spine and cerebrospinal fluid cytology. Finally, he died of sudden cardiac arrest during treatment. This is the first case of ISCM involving the whole spinal segments. Physicians should be aware of the subsequent development of ISCM in lung cancer patients with a previously known brain metastasis who present with new neurological symptoms.