• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.22 no.12
• /
• pp.1097-1106
• /
• 2011

In this paper, we present design method of wideband single-sideband mixer(SSM) with excellent sideband suppression and carrier suppression. We proposed SSM with 4-band split structure for uniform output flatness. From circuit simulation of this structure using Microwave OfficeTM, we got satisfactory results. We realized a SSM based on this results, then we experimented. The measured results show excellent agreements with the simulated results. We compared with two SSM's(target SSM(M Co. SM0218LC1CDC SSM) and our SSM) as well. The presented SSM is 3.35 times bigger, but sideband suppression is 3 dBc better and carrier suppression is 8 dBc better than those of comparative SSM, respectively.

• Annals of Clinical Neurophysiology
• /
• v.14 no.1
• /
• pp.29-35
• /
• 2012

Background: Peripheral neuropathy is the most frequent neurological complication in human immunodeficiency virus (HIV) infection, related with diverse etiologies including inflammation, opportunistic infection and side effects of medications. The purpose of the present study was to evaluate characteristics of HIV associated neuropathy according to the stage of HIV infection. Methods: In reviewing the medical records of HIV patients who underwent electrodiagnostic studies between 1997 and 2011, total 11 patients (all males; median age, 47 years; range, 28-71 years) with comorbid neuropathy were enrolled. Stage of HIV infection was categorized according to the Centers for Disease Control and Prevention (CDC) criteria. Classification of peripheral neuropathy was based on clinical and electrophysiological features. Results: Distal symmetric polyneuropathy was observed in 8 patients (72.7%), inflammatory demyelinating polyneuropathy in 2 patients (18.1%), and polyradiculopathy in 1 patient (9.1%). Median CD4+ T cell count was $123/mm^3$ (range, $8-540/mm^3$) and 7 patients (60%) had the most advanced HIV disease stage (CDC-C3). There was no neuropathy caused by CMV infection. Conclusions: Distal symmetric polyneuropathy was the most common type of neuropathy in HIV infection, but various forms of neuropathy such as inflammatory demyelinating polyneuropathy and polyradiculopathy were also present. HIV associated neuropathy is more frequently associated with advancing immunosuppression, although it can occur in all stages of HIV infection.

• Journal of Chest Surgery
• /
• v.53 no.5
• /
• pp.250-257
• /
• 2020

Background: Lung adenocarcinoma (LUAD) with ground-glass opacity (GGO) can become aggravated, but the reasons for this aggravation are not fully understood. The goal of this study was to analyze the genetic features and causes of progression of GGO LUAD. Methods: LUAD tumor samples and normal tissues were analyzed using an Illumina HiSeq 4000 system. After the tumor mutational burden (TMB) was calculated, the identified mutations were classified as those found only in GGO LUAD, those present only in nonGGO LUAD, and those common to both tissue types. Ten high-frequency genes were selected from each domain, after which protein interaction network analysis was conducted. Results: Overall, 227 mutations in GGO LUAD, 212 in non-GGO LUAD, and 48 that were common to both tumor types were found. The TMB was 8.8 in GGO and 7.8 in non-GGO samples. In GGO LUAD, mutations of FCGBP and SFTPA1 were identified. FOXQ1, IRF5, and MAGEC1 mutations were common to both types, and CDC27 and NOTCH4 mutations were identified in the non-GGO LUAD. Protein interaction network analysis indicated that IRF5 (common to both tissue types) and CDC27 (found in the non-GGO LUAD) had significant biological functions related to the cell cycle and proliferation. Conclusion: In conclusion, GGO LUAD exhibited a higher TMB than non-GGO LUAD. No clinically meaningful mutations were found to be specific to GGO LUAD, but mutations involved in the epithelial-mesenchymal transition or cell cycle were found in both tumor types and in non-GGO tissue alone. These findings could explain the non-invasiveness of GGO-type LUAD.

• BMB Reports
• /
• v.44 no.8
• /
• pp.529-534
• /
• 2011

Ribosomal protein S3 (rpS3) is a multifunctional protein involved in translation, DNA repair, and apoptosis. The relationship between rpS3 and cyclin-dependent kinases (Cdks) involved in cell cycle regulation is not yet known. Here, we show that rpS3 is phosphorylated by Cdk1 in G2/M phase. Co-immunoprecipitation and GST pull-down assays revealed that Cdk1 interacted with rpS3. An in vitro kinase assay showed that Cdk1 phosphorylated rpS3 protein. Phosphorylation of rpS3 increased in nocodazole-arrested mitotic cells; however, treatment with Cdk1 inhibitor or Cdk1 siRNA significantly attenuated this phosphorylation event. The phosphorylation of a mutant form of rpS3, T221A, was significantly reduced compared with wild-type rpS3. Decreased phosphorylation and nuclear accumulation of T221A was much more pronounced in G2/M phase. These results suggest that the phosphorylation of rpS3 by Cdk1 occurs at Thr221 during G2/M phase and, moreover, that this event is important for nuclear accumulation of rpS3.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.25 no.5
• /
• pp.857-862
• /
• 2011

The purpose of this study is to investigate the anti-proliferative mechanism by Trichosanthes kirilowii (TCK) in MCF-7 human breast carcinoma cell. In this study, we used human breast cancer cell line, Michigan cancer foundation-7 cells (MCF-7 cells). They were co-incubated with 30~200 ${\mu}g$/ml TCK for 48 hours, and cell viability was measured by Water-soluble tetrazolium salt-1 (WST-1) assay. After MCF-7 cells were exposed to 60 ${\mu}g$/ml of TCK for 0, 3, 6, 12, 24, 48 hours, We performed flow analysis cytometry sorting(FACS) and western blot analysis. We investigated the effect of dose-dependent cell growth inhibition by TCK, which could be proved by WST-1 assay. Also, flow cytometry analysis showed that TCK increased percentage of subG1 phase and G2/M phase cell cycle. In addition, TCK induced apoptosis through the expression of caspase-9, -3 and poly(ADP-ribose) polymerase(PARP) activation. Moreover, we showed that ATM-dependent G2/M phase arrest by DNA damage and phosphorylation of chk2, cdc25C, cdc2(Tyr15). Taken together, these results suggest that by G2/M phase arrest through DNA damage and inducing of apoptosis through intrinsic pathway, TCK may have potential tumor suppressor in breast cancer.

• The Journal of Internal Korean Medicine
• /
• v.32 no.2
• /
• pp.217-231
• /
• 2011

Objectives : This study aimed to evaluate the effects of Saengmaekcheongpye-eum (SCE) on a LPS-induced COPD (chronic obstructive pulmonary disease) model. Materials and Methods : The extract of SCE was treated to A549 cells and and LPS-induced COPD mouse model. Then, various parameters such as cell-based cyto-protective activity and histopathological finding were analyzed. Results : SCE showed a protective effect on LPS-induced cytotoxicity in A549 cells. This effect was correlated with analysis for caspase 3 levels, elastin contents, protein levels of cyclin B1, Cdc2, and phospho-Erk1/2, and gene expression of TNF-${\alpha}$ and IL-$1{\beta}$ in A549 cells. SCE treatment also revealed a protective effect on LPS-induced lung injury in COPD mouse model. This effect was evidenced via histopathological findings including immunofluorescence stains against elastin and caspase 3, and protein levels of cyclin B1, Cdc2, and Erk1/2 in lung tissue. Conclusions : These data suggest that SCE has pharmaceutical properties on lung injury. This study thus provides scientific evidence for the efficacy of SCE for clinical application to patients with COPD.

• Nutrition Research and Practice
• /
• v.14 no.2
• /
• pp.127-133
• /
• 2020

BACKGROUND/OBJECTIVES: Non-small cell lung cancer is mostly recognized among other types of lung cancer with a poor prognosis by cause of chemotherapeutic resistance and increased metastasis. Luteolin has been found to decrease cell metastasis. However, its underlying mechanisms remain unresolved. The objective of this study was to examine the effect (and its mechanism) of luteolin on the migration and invasion of human non-small cell lung cancer A549 cells. MATERIALS/METHODS: Cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Wound healing and transwell assays were evaluated to assess migration and invasion, respectively. Western blot analysis and immunofluorescence were further performed to investigate the role of luteolin and its mechanisms of action. RESULTS: Administration with up to 40 μM luteolin showed no cytotoxic activity on lung cancer A549 cells or non-cancer MRC-5 cells. Additionally, luteolin at 20-40 μM significantly suppressed A549 cells' migration, invasion, and the formation of filopodia in a concentration-dependent manner at 24 h. This is similar with western blot analysis, which revealed diminished the phosphorylated focal adhesion kinase (pFAK), phosphorylated non-receptor tyrosine kinase (pSrc), Ras-related C3 botulinum toxin substrate 1 (Rac1), cell division control protein 42 (Cdc42), and Ras homolog gene family member A (RhoA) expression levels. CONCLUSIONS: Overall, our data indicate that luteolin plays a role in controlling lung cancer cells' migration and invasion via Src/FAK and its downstream Rac1, Cdc42, and RhoA pathways. Luteolin might be considered a promising candidate for suppressing invasion and metastasis of lung cancer cells.

• BMB Reports
• /
• v.51 no.7
• /
• pp.350-355
• /
• 2018

HnRNPK is a multifunctional protein that participates in chromatin remodeling, transcription, RNA splicing, mRNA stability and translation. Here, we uncovered the function of hnRNPK in regulating the proliferation and differentiation of myoblasts. hnRNPK was mutated in the C2C12 myoblast cell line using the CRISPR/Cas9 system. A decreased proliferation rate was observed in hnRNPK-mutated cells, suggesting an impaired proliferation phenotype. Furthermore, increased G2/M phase, decreased S phase and increased sub-G1 phase cells were detected in the hnRNPK-mutated cell lines. The expression analysis of key cell cycle regulators indicated mRNA of Cyclin A2 was significantly increased in the mutant myoblasts compared to the control cells, while Cyclin B1, Cdc25b and Cdc25c were decreased sharply. In addition to the myoblast proliferation defect, the mutant cells exhibited defect in myotube formation. The myotube formation marker, myosin heavy chain (MHC), was decreased sharply in hnRNPK-mutated cells compared to control myoblasts during differentiation. The deficiency in hnRNPK also resulted in the repression of Myog expression, a key myogenic regulator during differentiation. Together, our data demonstrate that hnRNPK is required for myoblast proliferation and differentiation and may be an essential regulator of myoblast function.

• The Journal of the Korea Contents Association
• /
• v.18 no.7
• /
• pp.484-494
• /
• 2018

Middle East Respiratory Syndrome (MERS), which occurred in the Middle East in 2015, is the most acute respiratory infectious disease in Korea. The limitations of the government's ability to respond to the spread of MERS and the inadequate communication of the government to the public have reduced the public's confidence in the government's infectious disease management policy. And it became an opportunity to raise awareness that infectious diseases could easily break down the national anti-virus system. Therefore, this study investigated the emergency response system of the infectious disease in the United States and sought to improve the infection control system in Korea. In order to achieve the purpose of the study, we analyzed the government's response to the MERS in 2015, analyzed the organization structure and role of the US CDC, and IMS.

• Animal cells and systems
• /
• v.11 no.2
• /
• pp.129-134
• /
• 2007

The initiation of eukaryotic DNA replication requires assembly of the pre-replicative complex (Pre-RC) through the concerted action of Orc, Cdc6, Cdt1 and Mcm2-7 complex during G1 phase. The pre-RC assembly licenses individual replication origins for the initiation of DNA replication and sufficient number of the pre-RC is essential for proper progression of S phase. However, it is not well known how cells recognize the completion of the pre-RC assembly before G1-S transition. In order to understand the cellular responses to the defects in pre-RC assembly, we depleted the known components of pre-RC proteins using the small interference RNAs in HeLa cells. Although the defects of pre-RC assembly by the depletion of the pre-RC proteins such as Orc2, Cdt1, Mcm2 & Mcm10 did not elicit the activation of Chk1- or Chk2-dependent checkpoint pathways, these cells still showed significant decrease in the cellular level of Cdc25A proteins. These results suggests that a novel checkpoint pathway exist in HeLa cells, which is not dependent upon Chk1 or Chk2 proteins and play essential roles in the cellular responses to the defects in the pre-RC assembly. Also, among those four proteins tested in this study, the depletion of Mcm10 and Cdt1 proteins significantly increased the apoptotic cell death in HeLa cells, suggesting that these proteins not only play roles in the pre-RC assembly, but also are involved in the checkpoint responses to the defects in the pre-RC assembly.