• Journal of Life Science
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• v.29 no.12
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• pp.1337-1344
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• 2019

Osteoporosis is characterized by a reduction in bone mass and typically manifests as an increase in fractures. Because this disease is common in elderly populations and lifespans are rapidly increasing, the incidence of osteoporosis has also grown. Most drugs currently used for osteoporosis treatment target osteoclasts in the bone tissue to prevent absorption. However, these medications also cause certain side effects and, furthermore, cannot increase bone mass. Thus, in order to control osteoporosis, regenerative medicine that utilizes adult stem cells and osteoblasts has been extensively studied. Statins, also known as 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, are cholesterol-lowering drugs that have been widely prescribed for cardiovascular diseases. Interestingly, recent studies have reported the beneficial effects of various statins on bone formation via the activation of osteoblasts. Thus, the current study investigated the effects of seven statin-family drugs on osteoblast activity during osteogenic differentiation using adult stem cells from human periosteal tissue. Specifically, statin effects on alkaline phosphatase activity, an early marker of bone cell differentiation, and on calcium deposit, a late marker of bone cell differentiation, were assessed. The results demonstrate that some statins (for example, pitavastatin and pravastatin) have a weak but positive effect on bone formation, and the findings therefore suggest that statin treatments can be a novel modulator for osteogenic differentiation and regenerative medicine using periosteal stem cells.

• Journal of fish pathology
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• v.22 no.3
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• pp.263-273
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• 2009

There is an increasing number of reports describing Streptococcus parauberis as an important pathogen of cultured olive flounder Paralichthys olivaceus and starry flounder Platichthys stellatus in Korea. We tried to determine the effects of water temperature (14${^{\circ}C}$ and 21${^{\circ}C}$) on the pathogenicity in Streptococcal disease caused by S. parauberis. We have challenged 180 olive flounder by i.p injection to $2.0{\times}10^{7}$ live cells/fish. Mortality was monitored for 21 days post challenge. And histopathological characterizations as infection degree, tissue degeneration and/or bacterial distribution were investigated with H&E stain and in situ hybridization technique. Fifty percent and 16.7% of mortality occurred within 21 days at 21${^{\circ}C}$ and 14${^{\circ}C}$ water temperature, respectively. In most cases, the typical symptoms of olive flounder infected with S. parauberis were darkness of the skin, lethargy, mild abdominal distension cause by ascites, splenomegaly, congested liver and internal organs paleness. The pericardial sac contained large amounts of cloudy fluid. Numerous whitish nodules, which were variable in size and often confluent, were randomly scattered throughout the myocardium. Especially, pericarditis and/or myocarditis was observed in all tested fishes after death. Positive in reaction with S. parauberis were found in all tissues in situ hybridization analysis. The relative numbers of S. parauberis in heart were much more than in liver, spleen, kidney and stomach. We evaluated that S. parauberis strain causes serious damage in the pericardium, shortness of breath and the blood disorder. Therefore, pericarditis and myocarditis caused by S. parauberis were closely related to mortality of olive flounder.

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

• Radiation Oncology Journal
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• v.12 no.3
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• pp.271-284
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• 1994

Purpose : Phospholipase C(PLC) isozymes play significant roles in transmembrane signal transduction. PLC-${\gamma}1$ acts as the intracellular effector in signal transduction for cellular proliferation and differentiation. Ras oncoprotein is also involved in cell growth. We determined the biological significance of PLC and ras oncoprotein in regeneration following radiation and the effect of different modes of administration of 5-FU. Materials and Methods : To determine the effect of the administration mode of 5-FU on the regeneration of intestinal mucosa of rats following radiation, we compared the expression of PLC and ras oncoprotein in six groups. Group I had no treatment. Group II received radiation(8 Gy) only. Group III received radiation(8 Gy) and 5-FU(150mg/kg) continuous intravenous (iv) infusion for 12 hours. Group IV received radiation(8 Gy) and 5-FU(750mg/kg) iv bolus injection. Group V received only 5-FU(150mg/kg) continuous iv infusion for 12 hours, Group VI received only 5-FU (150mg/kg) iv bolus injection. Through immunoblotting and immunohistochemistry, we examined the expression of PLC and ras oncoprotein in rat jejunum at 96 hours after radiation or 5-FU administration and at 120 hours after radiation and 5-FU adminstration. We also investigated the histological findings using hematoxylin and eosin stain. Results : In the immunohistochemistry study, PLC-${\gamma}1$ expression was the highest in group III followed by groups II and VI in that order and was weakly positive in groups V and VI. PLC-${\gamma}1$ was hardly detected in the control group. The expression of ras oncoprotein was the same as the PLC-${\gamma}1$ expression for all groups. These results were confirmed by the histological findings regarding the mucosal regeneration. In the immunoblotting analysis, PLC-${\gamma}1$ expression was the highest in group III followed by group IV and II in that order. This difference between the immunoblotting and immunohistochemistry study was due to the high expression of PLC-${\gamma}1$ on the damaged surface epithelium rather than to its expression in the regeneration region as observed in the immunohistochemistry study for group IV. The expression of PLC-${\delta}1$ was positive only in group V and VI, which received both radiation and 5-FU, and the expression of PLC-${\beta}1$ was negligible for all groups. Conclusion : These results suggest that PLC-${\gamma}1$ mediated signal transduetion and ras oncoprotein may have a significant role in mucosal regeneration after radiation, and that continuous iv infusion of 5-FU may induce active regeneration in intestinal mucosa following radiation. In addition, the expression of PLC-${\delta}1$ in combined group of radiation and 5-FU implies that PLC-${\delta}1$ may be involved in signal transduction mediated by concerted action between radiation and 5-FU.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.347-355
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• 1999

Background: Phospholipase C(PLC) plays a central role in cellular signal transduction and is important in cellular growth, differentiation and transformation. There are currently ten known mammalian isozymes of PLC reported to this date. Hydrolysis of phosphatidylinositol 4,5-bisphosphate($PIP_2$) by PLC produces two important second messengers, inositol 1,4,5-trisphosphate($IP_3$) and diacylglycerol. PLC-${\gamma}1$, previously, was known to be activated mainly through growth factor receptor tyrosine kinase. Other mechanisms of activating PLC-yl have been reported such as activation through tau protein in the presence of arachidonic acid in bovine brain and activation by $IP_3$, phosphatidic acid, etc. Very recently, another PLC-${\gamma}1$ activator protein such as tau has been found in bovine lung tissue, which now is considered to be AHNAK protein. But there has been no report concerning AHNAK and its associated disease to this date. In this study, we examined the expression of the PLC-${\gamma}1$ activator, AHNAK, in lung cancer specimens and their paired normal. Methods: From surgically resected human lung cancer tissues taken from twenty-eight patients and their paired normal counterparts, we evaluated expression level of AHNAK protein using immunoblot analysis of total tissue extract Immunohistochemical stain was performed with primary antibody against AHNAK protein. Results: Twenty-two among twenty-eight lung cancer tissues showed overexpression of AHNAK protein (eight of fourteen squamous cell lung cancers, all of fourteen adenocarcinomas). The resulting bands were multiple ranging from 70 to 200 kDa in molecular weight and each band was indistinct and formed a smear, reflecting mobility shift mainly due to proteolysis during extraction process. On immunohistochemistry, lung cancer tissues showed a very heavy, dense staining with anti-AHNAK protein antibody as compared to the surrounding normal lung tissue, coresponding well with the results of the western blot Conclusion: The overexpression of PLC-${\gamma}1$ activator protein, AHNAK in lung cancer may provide evidence that the AHNAK protein and PLC-${\gamma}1$ act in concerted manner in carcinogenesis.

• Tuberculosis and Respiratory Diseases
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• v.47 no.6
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• pp.747-756
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• 1999

Background: Acid-fast stain and cultures for diagnosis of pulmonary tuberculosis are primary and essential method, but have their limitation : low sensitivity and time consuming. The objective of this study is comparison of amplified Mycobacterium tuberculosis direct test(MTD) by the conventional AFB smears and cultures in the detection of Mycobacterium tuberculosis in respiratory specimens. Methods: During the period between November, 1997 and May, 1998 a total of 267 respiratory specimens (sputum 173, bronchial washing 94) from 187 patients suspected pulmonary tuberculosis were subjected to AFB smears, cultures and MID test. MID is based on nucleic acid amplification. We compared the MID with 3% Ogawa culture method. In positive AFB smear and negative MID specimen, positive culture identification between nontuberculous mycobacterium and M.tuberculosis was assesed by using Accuprobe M.tuberculosis complex probe. In negative AFB smear and negative AFB culture, MTD results are assessed by clinical follow-up. Results : 1) Compared with culture in sputum and bronchial fluid specimens, sensitivity and specificity of MTD in positive AFB smear is 79.7% and 20.0%, sensitivity and specificity of MTD in negative AFB smear specimens is 75.0% and 79.7%. 2) Discrepant analysis is assessed by clinical follow-up and other specimen results beyond study. Culture negative but MTD positive specimens were proved to be true positive and gave MTD sensitivity 79.2%, specificity of 84.4%, positive predictive value 80.5% and negative predictive value 83.2%. 3) 14 out of 31 specimens in negative AFB smear, negative AFB culture and positive MTD showed pulmonary tuberculosis diagnosed on clinical follow-up and sensitivity is 45.2%. 4) 2 out of 13 specimens in positive AFB smear, positive AFB culture and negative MID diagnosed as non tuberculous mycobacterium by Accuprobe culture. Conclusion: This study suggested that MID in respiratory specimens is simple and rapid diagnostic method, but considered adjuvant method rather than replace the conventional AFB smear and culture.

• Investigative Magnetic Resonance Imaging
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• v.17 no.3
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• pp.181-191
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• 2013

Purpose : To evaluate the usefulness of in vivo magnetic resonance (MR) imaging for tracking intravenously injected superparamagnetic iron oxide (SPIO)-labeled human umbilical vein endothelial cells (HUVECs) in an acute renal failure (ARF) rat model. Materials and Methods: HUVECs were labeled with SPIO and poly-L-lysine (PLL) complex. Relaxation rates at 1.5-T MR, cell viability, and labeling stability were assessed. HUVECs were injected into the tail vein of ARF rats (labeled cells in 10 rats, unlabeled cells in 2 rats). Follow-up serial $T2^*$-weighted gradient-echo MR imaging was performed at 1, 3, 5 and 7 days after injection, and the MR findings were compared with histologic findings. Results: There was an average of $98.4{\pm}2.4%$ Prussian blue stain-positive cells after labeling with SPIOPLL complex. Relaxation rates ($R2^*$) of all cultured HUVECs at day 3 and 5 were not markedly decreased compared with that at day 1. The stability of SPIO in HUVECs was maintained during the proliferation of HUVECs in culture media. In the presence of left unilateral renal artery ischemia, $T2^*$-weighted MR imaging performed 1 day after the intravenous injection of labeled HUVECs revealed a significant signal intensity (SI) loss exclusively in the left renal outer medulla regions, but not in the right kidney. The MR imaging findings at days 3, 5 and 7 after intravenous injection of HUVECs showed a SI loss in the outer medulla regions of the ischemically injured kidney, but the SI progressively recovered with time and the right kidney did not have a significant change in SI in the same period. Upon histologic analysis, the SI loss on MR images was correspondent to the presence of Prussian blue stained cells, primarily in the renal outer medulla. Conclusion: MR imaging appears to be useful for in vivo monitoring of intravenously injected SPIO-labeled HUVECs in an ischemically injured rat kidney.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1285-1295
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• 1997

Background : EGFR is one of the initial step in signal transduction pathway about multistep carcinogenesis. It is homologous to oncogene erbB-2 and is the receptor for EGF and TGF alpha. EGFR has important role in the growth and differentiation of tumor cells. So, EGFR in non-small cell lung cancer was examined to search for possible evidence as clinical prognostic factor. Methods : To investigate the role of EGFR in lung cancer, the author performed immunohistochemical stain of EGFR on 57 resected primary non-small cell lung cancer specimens. And the author analyzed the correlation between EGFR expression, clinical parameters, Sand $G_1$ phase fraction and survival. Results : 1) EGFR were detected in 56% of total 57 patients (according to histologic type, squamous cancer 50%, adenocarcinoma 63%, large cell cancer 75%) (according to TNM stage, stage I 64%, stage II 38%, stage III 55%) (according to cellular differentiation, well 50%, moderately 52%, poorly 65%). All differences were insignificant 2) Using the flow cytometric analysis, mean S-phase fraction of EGFR (+) and (-) group were 22.3(${\pm}10.5$)%. 18.0(${\pm}10.9$)% (p>0.05), mean $G_1$-phase fraction of EGFR (+) and (-) group were 68.4(${\pm}11.6$)%, 71.1(${\pm}12.8$)%, (p>0.05) 3) Two-year survival rate of EGFR (+) and (-) group were 53%, 84%, median survival time of EGFR (+) and (-) group were 26, 53 months. (p<0.05, Kaplan-Meier, generalized Wilcox) Conclusion : EGFR immunostaining may be a simple and useful method for survival prediction in non-small cell lung cancer.

• Pediatric Infection and Vaccine
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• v.9 no.1
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• pp.85-94
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• 2002

Purpose: This study was performed for analysis of the results of polymerase chain reaction(PCR) and antibody test of Mycoplasma pneumoniae(M. pneumoniae) in children with symptoms of respiratory tract infection. In the cases of both positive antibody test and PCR for M. pneumoniae, the chest X-ray findings were assessed. Methods: The antibody test was done in 1,979 cases who have been admitted to Wonkwang university hospital department of pediatrics with symptoms of respiratory tract infection from January, 2000 to December, 2001. The positive antibody test was defined as titer of 1 : 80 and over 1 : 80. The PCR of M. pneumoniae were done in randomly selected 131 cases of respiratory tract infection. The chest X-ray findings were assessed in the cases of positive antibody test and PCR. Results: The numbers of cases of the positive antibody test for M. pneumoniae were 499 cases(25%). The PCR for M. pneumoniae were performed in 131 cases and the 45 cases(34%) were positive and 86 cases(66%) were negative. The 56 of 86 PCR negative cases were also negative antibody test, but 30 cases were positive antibody test. The 36 cases of 45 PCR positive cases were antibody positive, and 9 cases were antibody negative. The sputum Gram stain and culture for M. pneumoniae were negative in all the 499 cases of mycoplasma antibody positive respiratory infection. In these antibody positive 499 cases, the most common X-ray findings was interstitial pneumonic infiltration in 266 cases(53%), and pleural effusion were detected in 22 cases(4%), but nonspecific chest X-ray finding showed in 129 cases(26%). In PCR positive 45 cases, the most common chest X-ray finding was interstitial pneumonic infiltration in 32 cases(71%). Conclusion: The PCR for M. pneumoniae is more useful method for detection of mycoplasma infection in children with respiratory tract infection. The M. pneumoniae is a important etiologic agent for respiratory infection in children.

• Radiation Oncology Journal
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• v.19 no.4
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• pp.335-344
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• 2001

Purpose : The aim of this study was to clarify the role of VEGF expression as an independent prognostic factor and to identify the patients at high risk for poor prognosis in stage IB cervical cancer. Materials and methods : A total of 118 patients with stage IB cervical cancer who had radical hysterectomy and pelvic lymph node dissection were included in the study. All known high risk factors of the patients were pathologically confirmed from the surgical specimen. Of the 118 patients, n patients were treated with postoperative radiotherapy and/or chemotherapy. VEGF expression was examined using immunohistochemistry in formalin-fixed, paraffin-embedded specimens of post-hysterectomy surgical materials. A semiquantitative analysis was made using a scoring system of 0, +, ++, and +++ for increasing intensity of stain. We classified the patients with scores from 0 to ++ as low VEGF expression and the patients with a score of +++ as high VEGF expression. Results : Of the 118 patients, 35 patients $(29.7\%)$ showed high VEGF expression. Strong correlations were found between the high VEGF expression and both deep stromal invasion (p=0.01) and the positive pelvic node (p=0.03). The 5-year overall and disease-free survival rates for all 118 patients were $95.5\%\;and\;93.8\%$. The 5-year overall (p=0.03) and disease-free survival (p<0.001) rates were $98.5\%\;and\;100%$ for low VEGF expression (0, +, and ++) and $85.5\%\;and\;79.7\%$ for high VEGF expression, respectively. Pelvic and distant failures for low versus high VEGF expression were $1.2\%$ versus $17.1\%$, (p=0.001) and $0\%$ versus $14.3\%$ (p<0.001), respectively. In a Cox multivariate analysis of survival, the high VEGF expression (p=0.02) and the bulky mass (p=0.02) were significant prognostic factors for overall survival. The high VEGF expression (p=0.002), and bulky mass (p=0.01) demonstrated as significant prognostic indicators for disease free survival. Conclusion : These results showed that VEGF expression was a highly significant predictor for pelvic and distant failure and the most significant prognostic factor of overall and disease free survival for the patients with stage IB cervix cancer treated with radical surgery. We strongly suggest that the immune-histochemistry for VEGF expression be performed in a routine clinical setting in order to identify the patients at high risk for poor prognosis in early stage cervical cancer. Furthermore, postoperative and/or chemotherapy did not reduce the pelvic failure and distant metastasis. To improve the cure rate for the patients with high VEGF expression in stage IB cervical cancer, antiangiogenic therapy including anti-VEGF Ab may be new treatment option.