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Soo Hyeon Kim Ho Jun Lee Ji-Chul Yoo Hyun Jung Park Ju Yeon Jeong Ye Been Seo 《Journal of biomaterials science. Polymer edition》2018,29(7-9):997-1010
AbstractTo increase healing rate of tympanic membrane (TM) perforations, patching procedure has been commonly conducted. Biocompatible, biodegradable patching materials which is not limited across cultures is needed. The authors evaluated the effectiveness of novel transparent duck’s feet collagen film (DCF) patch in acute traumatic TM perforation. This procedure was compared with spontaneous healing and paper patching. Cell proliferation features were observed in paper and DCF patches. Forty-eight TMs of 24 rats were used for animal experiment, perforations were made on each TMs, and divided into three groups according to treatment modality. Sixteen were spontaneously healed, 16 were paper patched and 16 were DCF patched. The gross and histological healing results were analyzed. Both paper and DCF patch showed no cytotoxicity, but cell proliferations were more active in DCF than paper in early stage. In animal study, the healing of TM perforations were completed within 14 days in all three groups, but found to be faster in DCF patch group than paper patch or spontaneous healing group. The DCF patches were transparent and size of DCF patches were gradually decreased, so there were no need to remove the DCF patches to check the wound status or after the completion of healing. According to this result, authors concluded that DCF patch is transparent, biocompatible and biodegradable material, and can induce fast healing in acute traumatic TM perforations. 相似文献
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Min S. Kim Yoo R. Kim Nam J. Yoo Sug H. Lee 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2013,121(2):85-94
DNMT3A, a DNA methyltransferase that functions for de novo methylation, is important in development and many cellular processes related to tumorigenesis. Somatic mutations of DNMT3A gene, including recurrent mutations in its Arg‐882, were recently reported in acute myelogenous leukemia (AML), strongly suggesting its role in development of AML. To see whether DNMT3A mutation occurs in other malignancies as well, we analyzed DNMT3A in 916 cancer tissues from 401 hematologic malignancies (AML, acute lymphoblastic leukemias (ALL), multiple myelomas and lymphomas) and 515 carcinomas (lung, breast, prostate, colorectal and gastric carcinomas) using a single‐strand conformation polymorphism (SSCP) assay. We identified DNMT3A mutations, especially the Arg‐882 mutations, in adulthood AML (9.4%). In addition, we found DNMT3A mutations in pre‐B‐ALL and three lung cancers at lower frequencies. Allelic loss of DNMT3A was frequently observed in most cancer types analyzed, including lymphomas (48.1%), gastric cancers (23.5%) and lung cancers (18.3%) irrespective of DNMT3A mutation. Also, loss of DNMT3A expression was common in lung cancers (46.4%), and was associated with the allelic loss. Our data indicate that DNMT3A gene is mutated mainly in AML, but it occurs in other cancers, such as ALL and lung cancer, despite the lower incidences. Also, the data suggest that DNMT3A is altered in many cancer types by various ways, including somatic mutations, allelic loss and loss of expression that might play roles in tumorigenesis. 相似文献
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Yeon Ju Bae Jae-Cheal Yoo Nammi Park Dawon Kang Jaehee Han Eunmi Hwang Jae-Yong Park Seong-Geun Hong 《The Korean journal of physiology & pharmacology》2013,17(1):57-64
Cells can resist and even recover from stress induced by acute hypoxia, whereas chronic hypoxia often leads to irreversible damage and eventually death. Although little is known about the response(s) to acute hypoxia in neuronal cells, alterations in ion channel activity could be preferential. This study aimed to elucidate which channel type is involved in the response to acute hypoxia in rat pheochromocytomal (PC12) cells as a neuronal cell model. Using perfusing solution saturated with 95% N2 and 5% CO2, induction of cell hypoxia was confirmed based on increased intracellular Ca2+ with diminished oxygen content in the perfusate. During acute hypoxia, one channel type with a conductance of about 30 pS (2.5 pA at -80 mV) was activated within the first 2~3 min following onset of hypoxia and was long-lived for more than 300 ms with high open probability (Po, up to 0.8). This channel was permeable to Na+ ions, but not to K+, Ca+, and Cl- ions, and was sensitively blocked by amiloride (200 nM). These characteristics and behaviors were quite similar to those of epithelial sodium channel (ENaC). RT-PCR and Western blot analyses confirmed that ENaC channel was endogenously expressed in PC12 cells. Taken together, a 30-pS ENaC-like channel was activated in response to acute hypoxia in PC12 cells. This is the first evidence of an acute hypoxia-activated Na+ channel that can contribute to depolarization of the cell. 相似文献
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Jong-Sun Yoo Yun-Jung Lee Joo Won Yoon Kyeong Eun Hyung Kwang Woo Hwang 《The Korean journal of physiology & pharmacology》2012,16(5):349-353
Activated T cells express inhibitory receptors such as CTLA-4 that can downregulate immune responses. Blockade of or genetic deficiency in CTLA-4 can result in autoimmunity. Therefore, strategies to increase the inhibitory function of CTLA-4 may be attractive in settings of undesirable T cell responses such as autoimmunity or transplant rejection. We have tested the hypothesis that transgenic constitutive expression of CTLA-4 can further attenuate immune responses when compared with normal inducible expression. Our results indicate that transgenic expression of CTLA-4 in mouse T cells (CTLA-4-Tg T cells) results in reduced cell cycle progression and increased apoptosis of TCR-stimulated T cells. CTLA-4-Tg T cells display reduced T cell proliferation in an in vivo model of graft versus host disease (GVHD). These results further our understanding of how CTLA-4 can be manipulated to inhibit immune responses and may help development of new therapeutic strategies for clinical settings of autoimmunity and transplantation. 相似文献
110.
Hye-Dong Yoo Dan Leung Jasbinder Sanghara Darren Daley Rob Soest Raymond J. Andersen 《Pharmaceutical biology》2013,51(4):223-225
The novel sesquiterpene hydroquinone isoarenarol (1) and the known compound arenarol (2) were isolated from extracts of the marine sponge Dysidea arenaria Bergquist as part of a search for new protein kinase inhibitors. Both 1 and 2 showed potent and selective protein kinase inhibition in vitro. 相似文献