• Korean Journal of Microbiology
• /
• v.45 no.3
• /
• pp.246-250
• /
• 2009

Retroviruses enter host cells by membrane fusion between the viral Env proteins on the virus membrane and a virus receptor on the cellular membrane. The envelope protein of the ecotropic Moloney murine leukemia virus is synthesized as a gp85 precursor and is proteolytically cleaved into an extracellular surface unit (SU) and the transmembrane protein (TM). The cytoplasmic tail (16 amino acid; R peptide) of the TM protein is further cleaved by the viral protease during virion maturation. Unlike the wild type Env protrin bearing the R peptide, R peptide-truncated Envelope induces syncytia in susceptible cells. To understand the mechanism of R peptidetruncated Env in syncytium formation, R peptide-truncated Env expressing full-length molecular clone containing EGFP in PRR (proline rich region) of Env was constructed. This molecular clone induced syncytia in transfected NIH3T3 cells, fluorescence was detected in the cytoplasm and at the plasma membrane, while the nuclei did not stain and appeared black by fluorescence microscopy. Interestingly, virions with truncated envelope produced from transfected NIH3T3 cells induced syncytia in NIH3T3 cells, but fluorescence was not detected in the same infected cells. It is believed that cell-free viruses direct the fusion of neighboring cells without infection. Our data suggests that use of EGFP-tagged envelope for monitoring syncytium is a sensitive and convenient method. We also found that virion incorporated the R peptide-truncated Env is able to induce the formation of syncytia by fusion from without.

• Korean Journal of Microbiology
• /
• v.52 no.3
• /
• pp.319-326
• /
• 2016

An antimicrobial bacterium to pathogenic microorganisms, strain $W5-1^T$ was isolated from Korean fermented-food Kimchi. The isolate was Gram-staining-variable, strictly aerobic, rod-shaped, endospore-forming, and motile with peritrichous flagella. It grew at $15-40^{\circ}C$, at pH 6.0-10.0, and in the presence of 0-4% NaCl. Strain $W5-1^T$ could hydrolyze esculin and xylan, and assimilate $\small{D}$-mannose, but not $\small{D}$-mannitol. Strain $W5-1^T$ showed antimicrobial activity against Listeria monocytogens, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhi. The G+C content of the DNA of strains $W5-1^T$ was 52.6 mol%. The predominant respiratory quinone was menaquinone-7 (MK-7) and the major cellular fatty acids were $C_{16:0}$, antieiso-$C_{15:0}$, $C_{18:0}$, and $C_{12:0}$. The strain contained meso-diaminopimelic acid in cell-wall peptidoglycan. On the basis of 16S rRNA gene sequence and phylogenetic analysis, the strain W5-1 was shown to belong to the family Paenibacillaceae and was most closely related to Paenibacillus pinihumi $S23^T$ (98.4% similarity) and Paenibacillus tarimensis $SA-7-6^T$ (96.4%). The DNA-DNA relatedness between the isolate and Paenibacillus pinihumi $S23^T$ was 8.5%, indicating that strain $W5-1^T$ represented a species in the genus Paenibacillus. On the basis of the evidence from this polyphasic study, it is proposed that strain $W5-1^T$ is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus kimchicus sp. nov. is proposed. The type strain is $W5-1^T$ (=KACC $15046^T$ = $LMG 25970^T$).

• Journal of Life Science
• /
• v.16 no.6
• /
• pp.1052-1059
• /
• 2006

The heat shock response is induced by environmental stress, pathophysiological state and non-stress conditions and wide spread from bacteria to human. Although translations of most proteins are stopped under a heat shock response, heat shock proteins (HSPs) are produced to protect cell from stress. When heat shock response is induced, conformation of HSF1 was changed from monomer to trimer and HSF1 specifically binds to DNA, which was called a heat shock element(HSE) within the promoter of the heat shock genes. Human HSF1(hHSFl) contains five cysteine(Cys) residues. A thiol group(R-SH) of Cys is a strong nucleophile, the most readily oxidized and nitrosylated in amino acid chain. This consideration suggests that Cys residues may regulate the change of conformation and the activity of hHSF1 through a redox-dependent thiol/disulfide exchange reaction. We want to construct role of five Cys residues of hHSF by redox reagents. According to two studies, Cys residues are related to trimer formation of hHSF1. In this study, we want to demonstrate the correlation between structural change and DNA-binding activity of HSF1 through forming disulfide bond and trimerization. In this results, we could deduce that DNA binding activity of DNA binding domain wasn't affected by redox for always expose outside to easily bind to DNA. DNA binding activity of wild-type HSF's DNA binding domain was affected by conformational change, as conformational structure change (trimerization) caused DNA binding domain.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.2
• /
• pp.352-367
• /
• 1998

Intracellular pH (pHi) plays an important role in the regulation of cellular processes by influencing the acitivity of various enzymes in cells. Therefore, almost every type of mammalian cell possesses an ability to regulate its pHi. One of the most prominent mechanisms in the regulation of pHi is $Na^+/H^+$ exchanger. This exchanger has been known to be activated when cells are stimulated by the binding of agonist to the muscarinic receptors. Therefore, the aims of this study were to compare the rates of $H^+$ extrusion through $Na^+/H^+$ exchanger before and during muscarinic stimulation and to investigate the possible existence of $HCO_3^-$ transporter which is responsible for the continuous supply of $HCO_3^-$ ion to saliva. Acinar cells were isolated from the rat mandibular salivary glands and loaded with pH-sensitive fluoroprobe, 2', 7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein(BCECF), for 30min at room temperature. Cells were attached onto the coverglass in the perfusion chamber and the changes in pHi were measured on the iverted microscope using spectrofluorometer. 1. By switching the perfusate from $HCO_3^-$-free to $HCO_3^-$-buffered solution, pHi decreased by $0.39{\pm}0.02$ pH units followed by a slow increase at an initial rate of $0.04{\pm}0.007$ pH units/min. The rate of pHi increase was reduced to $0.01{\pm}0.002$ pH units/min by the simultaneous addition of 1 mM amiloride and $100{\mu}M$ DIDS. 2. An addition and removal of $NH_4^+$ caused a decrease in pHi which was followed by an increase in pHi. The increase of pHi was almost completely blocked by 1mM amiloride in $HCO_3^-$-free perfusate which implied that the pHi increase was entired dependent on the activation of $Na^+/H^+$ exchanger in $HCO_3^-$-free condition. 3. An addition of $10{\mu}M$ carbachol increased the initial rate of pHi recovery from $0.16{\pm}0.01$ pH units/min to $0.28{\pm}0.03pH$ units/min. 4. The initial rate of pHi decrease induced by 1mM amiloride was also increased by the exposure of the acinar cells to $10{\mu}M$ carbachol ($0.06{\pm}0.008pH$ unit/min) compared with that obtained before carbachol stimulation ($0.03{\pm}0.004pH$ unit/min). 5. The intracellular buffering capacity ${\beta}1$ was $14.31{\pm}1.82$ at pHi 7.2-7.4 and ${\beta}1$ increased as pHi decreased. 6. The rate of $H^+$ extrusion through $Na^+/H^+$ exchanger was greatly enhanced by the stimulation of the cells with $10{\mu}M$ carbachol and there was an alkaline shift in the activity of the exchanger. 7. An intrusion mechanism of $HCO_3^-$ was identified in rat mandibular salivary acinar cells. Taken all together, I observed 3-fold increase in $Na^+/H^+$ exchanger by the stimulation of the acinar cells with $10{\mu}M$ carbachol at pH 7.25. In addition, I have found an additional mechanism for the regulation of pHi which transported $HCO_3^-$ into the cells.

• Tuberculosis and Respiratory Diseases
• /
• v.59 no.5
• /
• pp.530-535
• /
• 2005

Background and Aims : Cigarette smoking induces an inflammatory response in the airways, which may play a key role in the pathogenesis of chronic obstructive pulmonary disease. Interleukin-6 (IL-6) is one of the cytokines that plays an important role in inducing bronchial inflammation. The aim of this study was to determine if the level of the pro-inflammatory cytokine, Interleukin-6, is increased when the bronchial epithelial cells are exposed to a cigarette smoke extract (CSE) and an extract from stop smoking-aiding cigarettes, and examined the safety of these commercially available stop smoking-aiding cigarettes. Method : Bronchial epithelial cells were exposed to CSE from cigarette and stop smoking-aiding cigarettes for 24 hours. ELISA was used to measure the IL-6 levels in the supernatant from each condition. The IL-6 mRNA levels were measured by Taqman Real time RT-PCR. N-acetyl-L-cysteine(NAC) was added to each condition to determine if NAC can inhibit the release of IL-6 from the bronchial epithelial cells when they are exposed to CSE from cigarette and stop smoking-aiding cigarettes. Result : When bronchial epithelial cells were exposed to a CSE from cigarettes and stop smoking-aiding cigarettes, each type of CSE stimulated IL-6 production from the bronchial epithelial cells. The IL-6 mRNA level in the Bronchial epithelial cells was also elevated and NAC was found to inhibit the release of IL-6 from bronchial epithelial cells when they were exposed to the CSE from cigarettes and stop smoking-aiding cigarettes. Conclusion : Commercially available stop smoking-aiding cigarette can induce bronchial inflammation and can be harmful to smokers. Therefore, the safety of these cigarettes for smoking cessation should be evaluated.

• Radiation Oncology Journal
• /
• v.24 no.3
• /
• pp.164-170
• /
• 2006

[ $\underline{Purpose}$ ]: This study identified the result of postoperative radiation therapy and the prognostic factors to affect survival rates in cancer patients. $\underline{Materials\;and\;Methods}$: One hundred and thirty three patients with cervical cancer who were treated with postoperative radiation therapy following surgery at our institution between June 1985 and November 2002 were retrospectively analyzed. One hundred and thirteen patients had stage IB disease, and 20 patients had stage IIA disease. Histological examination revealed 118 squamous cell carcinoma patients and 15 adenocarcinoma patients. Sixty seven patients were noted to have stromal invasion greater than 10 mm, and 45 patients were noted to have stromal Invasion 10 mm or less. Positive lymphovascular invasion was found in 24 patients, and positive pelvic lymph nodes were noted in 39 patients. Positive vaginal resection margin was documented in 8 patients. All of the patients were treated with external beam radiation therapy to encompass whole pelvis and primary surgical tumor bed. Intracavitary radiation therapy was added to 19 patients who had positive or close surgical margins. $\underline{Results}$: Actuarial overall and disease-free survival rates for entire group of the patients were 88% and 84% at 5 years, respectively. Five-year disease-free survival rates for patients with stromal invasion greater than 10 mm and 10 mm or less were 76% and 97%, respectively (p<0.05). Also there was a significantly lower survival in patients with positive pelvic lymph nodes compared with patients with negative pelvic lymph nodes (p<0.05). However, lymphovascular invasion, positive vaginal resection margins were not statistically significant prognostic factors. Addition of neoadjuvant chemotherapy or type of surgery did not affect disease-free survival. $\underline{Conclusion}$: Postoperative radiation therapy appears to achieve satisfactory local control with limited morbidity in cervical cancer patients with high pathologic risk factors. Distant metastasis was a dominant failure pattern to affect survival in cervical cancer patients after radical surgery and radiation and more effective systemic treatment should be investigated in these high-risk patients.

• The Korean Journal of Zoology
• /
• v.31 no.2
• /
• pp.111-121
• /
• 1988

This study was attempted to investigate the regional distribution and shapes of pancreatic endocrifle cells in the hedgehog, Erinaceus koneanus by the immunocytochemical PAP methods (Nalane, 1968; Stemberger, 1979). The tissue specimen taken from the splenic and duodenal regions of pancreas(proximai, middle and distal portions, respectively) were fixed with Bouin solution and the sections(5$\mu$ m) were followed by simple and double staining with 2 substrates, DAB and 4-CI-1-naphthol. The results were as following: Glucagon(A) cells, 13 $\mu$ m x 9.5 $\mu$ m in size, were found in the islets periphery and among the exocrine parenchyma. A cells were abundant in all the portions of splenic region and distal portion of duodenal region in contrast to a few in the proximal and middle portion of duodenal region. The shapes of the A cells were round, oval and pyramidal types. Insulin(B) cells, 11.6$\mu$m x 9.4$\mu$m in sise, were round or oval in shape and located throughout the islets. B cells were the most numerous cell types in all portions of splenic region and distal protion of duodenal region as compared with the other portions. Somatostatin(D) cells, 12.6$\mu$m x 9.1 $\mu$m in size, were round or oval in shape and found in the islets periphery and scattered in the exocrine parenchyma. These cells were rare in all the portions of splenic and duodenal region. Pancreatic polypeptide(PP) cells of various type, 12.8$\mu$ m x 8.5 $\mu$ m in size, were found in the islets periphery and among the exocrine parenchyma. PP cells were numerous in the proximal and middle portion of duodenal region, but rarely scattered in the other portions.

• Journal of Life Science
• /
• v.24 no.8
• /
• pp.820-826
• /
• 2014

The localization to specific subcellular sites and the regulation of cell surface receptors and channels are crucial for proper functioning. Postsynaptic density-95/Disks large/Zonula occludens-1 (PDZ)-domain is involved in recognition of and interaction between various proteins, by which the localization and the regulation are mediated. Multi-PDZ domain protein 1 (MUPP1) contains 13 PDZ domains. MUPP1 serves a scaffolding function for structure proteins and signaling proteins, but the mechanism how MUPP1 is stabilized and signalized has not yet been elucidated. We used the yeast two-hybrid system to identify proteins that interact with PDZ domains of MUPP1. We found an interaction between MUPP1 and Parkin. Parkin is an E3 ubiquitin ligase. Loss-of-function mutations of Parkin gene are known to cause an autosomal recessive juvenile parkinsonism. Parkin bound to the $12^{th}$ PDZ domain, but not to other PDZ domains of MUPP1. The C-terminal end of Parkin has a type II PDZ-association motif, which was essential for the interaction with MUPP1 in the yeast two-hybrid assay. When co-expressed in HEK-293T cells, Parkin co-localized with MUPP1. When co-expressed with ubiquitin in HEK-293T cells, MUPP1 has been strongly ubiquitinated by Parkin. These findings collectively suggest that MUPP1 is a novel substrate of Parkin and its function or stability could be modulated by Parkin-mediated ubiquitination.

• Radiation Oncology Journal
• /
• v.18 no.4
• /
• pp.226-232
• /
• 2000

Purpose :This study was performed to find out the prognostic factors affecting local control in early glottic cancer treated with radiation therapy alone. Materials and Methods :We analysed 37 patients of histologically confirmed early glottic cancer treated at Chonnam National University Hospital between July Im and December 1995, retrospectively. Age of patients ranged from 30 to 73 years (median; 59 years). Thirty-five (95$\%$) patients were male. Histological type was all squamous cell carcinoma. According to the staging system of 1997 American Joint Committee on Cancer, 37 patients were restaged as follows: Tla; U (73$\%$), Tlb; 3 (8$\%$), 72: 7 (19$\%$). Radiation therapy was done using 6 MV X-ray of linear accelerator The range of total radiation dose delivered to the glottic lesion was between 5,040 cGy and 7,020 cGy (median; 6,600 cGy). Median follow-up period was U months. local control rates were calculated by Kaplan-Meier method. Generalized Wilcoxon test was used to evaluate the difference of control rates between comparable groups. Multivariate analysis using Cox proportional hazard model was done to find out prognostic factors affecting local control. Results:5 year survival rate of 37 patients was 89$\%$. Local control rate of 37 patients was 74$\%$ in 5 years. We included age, 7-stage, anterior commissure involvement, fraction size, total radiation dose, treatment time of radiotherapy as potential prognostic factors in univariate and multivariate analysis. As a result, treatment time had statistical significance in local control rate in both univariate (p=0.026) and multivariate (p=0.017) analysis. Complication was not recorded except one patient with hypothyroidism. Conclusion :This study revealed that overall treatment time of radiation was a significant factor affecting local control rate.

• Tuberculosis and Respiratory Diseases
• /
• v.45 no.4
• /
• pp.766-775
• /
• 1998

Background : The prognosis of patients with lung cancer is still poor. Lung cancer exhibits a variable clinical outcome, even in those patients with same stage. Numerous reports suggest that oncogene expression might playa role in explaining the variability of response and survival But many of these reports are still under debate. So we studied the clinical relevance of oncogene expression in Korean lung cancer patients. Immunohistochemistry of p53, erbB-2, CEA expression was performed. Method: From March, 1992 until March, 1997, 120 patients with lung cancer were reviewed. p53, erbB-2, and CEA expression were detected on paraffin-embedded tumor blocks with the use of monoclonal antibodies. The survival and response has correlated with the expressibility of p53, erbB-2, and CEA oncoprotein Results: Overall, the expression rates of p53, erbB-2, and CEA were 33.7%, 59.3%, and 32.6% respectively. Expression rates were not correlated to cell type or stage. Compared with response to chemotherapy, no correlation was found. The expression of p53, erbB-2, or CEA was not correlated with 2-year survival. With simultaneous applications of p53, erbB-2, and CEA, patients with 2 or more expressions also did not show poor response to chemotherapy. Conclusion: We conclude the p53, erbB-2, and CEA expression are clinically less useful in predicting response to chemotherapy or survival.