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Seo Y, Nam J, Yun H, Jun MBG, Lee D. Effect of Au-Coating on the Laser Spot Cutting on Spring Contact Probe (SCP) for Semi-Conductor Inspection. Materials (Basel) 2021; 14:ma14123300. [PMID: 34203677 PMCID: PMC8232112 DOI: 10.3390/ma14123300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 11/16/2022]
Abstract
Spring contact probes (SCPs) are used to make contact with various test points on printed circuit boards (PCBs), wire harnesses, and connectors. Moreover, they can consist of the test interface between the PCBs and the semiconductor devices. For mass production of SCPs, ultra-small precision components have been manufactured by conventional cutting methods. However, these cutting methods adversely affect the performance of components due to tool wear and extreme shear stress at the contact point. To solve this problem, laser spot cutting is applied to Au-coated SCP specimens as an alternative technique. A 20 W nano-second pulsed Ytterbium fiber laser is used, and the experimental variables are different laser parameters including the pulse duration and repetition rate. After the spot cutting experiments, the heat-affected zone (HAZ) and material removal zone (MRZ) formed by different total irradiated energy (Etotal) was observed by using a scanning electron microscope (SEM). Then, the size of HAZ, top and bottom parts of MRZ, and roundness were measured. Furthermore, the change rate of HAZ and MRZ on Au-coated and non-coated specimens was analyzed with regard to different pulse durations. Based on these results, the effect of Au-coating on the SCP was evaluated through the comparison with the non-coated specimen. Consequently, in the Au-coated specimen, hole penetration was observed at a low pulse duration and low total energy due to the higher thermal conductivity of Au. From this study, the applicability of laser spot cutting to Au-coated SCP is investigated.
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Affiliation(s)
- Youngjin Seo
- Department of Future Convergence Engineering, Kongju National University, Cheonan 31080, Korea;
| | - Jungsoo Nam
- Intelligent Manufacturing System R&D Department, Korea Institute of Industrial Technology, Cheonan 31056, Korea;
- Department of Mechanical Engineering, Purdue University, West Lafayette, IN 47907-2088, USA; (H.Y.); (M.B.G.J.)
| | - Huitaek Yun
- Department of Mechanical Engineering, Purdue University, West Lafayette, IN 47907-2088, USA; (H.Y.); (M.B.G.J.)
| | - Martin Byung Guk Jun
- Department of Mechanical Engineering, Purdue University, West Lafayette, IN 47907-2088, USA; (H.Y.); (M.B.G.J.)
| | - Dongkyoung Lee
- Department of Future Convergence Engineering, Kongju National University, Cheonan 31080, Korea;
- Department of Mechanical and Automotive Engineering, Kongju National University, Cheonan 31080, Korea
- Correspondence:
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Lim JY, Nam JS, Shin H, Park J, Song HI, Kang M, Lim KI, Choi Y. Identification of Newly Emerging Influenza Viruses by Detecting the Virally Infected Cells Based on Surface Enhanced Raman Spectroscopy and Principal Component Analysis. Anal Chem 2019; 91:5677-5684. [DOI: 10.1021/acs.analchem.8b05533] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Jae-young Lim
- Department of Bio-convergence Engineering, Korea University, Seoul 02841, South Korea
| | - Jung-soo Nam
- Department of Medical & Pharmaceutical Sciences, Sookmyung Women’s University, Seoul 04310, South Korea
| | - Hyunku Shin
- Department of Bio-convergence Engineering, Korea University, Seoul 02841, South Korea
| | - Jaena Park
- Department of Bio-convergence Engineering, Korea University, Seoul 02841, South Korea
| | - Hye-in Song
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Seoul 04310, South Korea
| | - Minsung Kang
- Department of Bio-convergence Engineering, Korea University, Seoul 02841, South Korea
| | - Kwang-il Lim
- Department of Medical & Pharmaceutical Sciences, Sookmyung Women’s University, Seoul 04310, South Korea
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Seoul 04310, South Korea
| | - Yeonho Choi
- Department of Bio-convergence Engineering, Korea University, Seoul 02841, South Korea
- School of Biomedical Engineering, Korea University, Seoul 02841, South Korea
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Lim JY, Nam JS, Yang SE, Shin H, Jang YH, Bae GU, Kang T, Lim KI, Choi Y. Identification of Newly Emerging Influenza Viruses by Surface-Enhanced Raman Spectroscopy. Anal Chem 2015; 87:11652-9. [DOI: 10.1021/acs.analchem.5b02661] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Jae-young Lim
- Department
of Bio-convergence Engineering, Korea University, Seoul, 136-713, Korea
| | - Jung-soo Nam
- Department of Medical & Pharmaceutical Sciences, Sookmyung Women’s University, Seoul, 140-742, Korea
| | - Se-eun Yang
- Department
of Bio-convergence Engineering, Korea University, Seoul, 136-713, Korea
| | - Hyunku Shin
- Department
of Bio-convergence Engineering, Korea University, Seoul, 136-713, Korea
| | - Yoon-ha Jang
- Department of Medical & Pharmaceutical Sciences, Sookmyung Women’s University, Seoul, 140-742, Korea
| | - Gyu-Un Bae
- Research
Center for Cell Fate Control, College of Pharmacy, Sookmyung Women’s University, Seoul, 140-742, Korea
| | - Taewook Kang
- Department of Chemical & Biomolecular Engineering, Sogang University, Seoul, 121-742, Korea
| | - Kwang-il Lim
- Department of Medical & Pharmaceutical Sciences, Sookmyung Women’s University, Seoul, 140-742, Korea
| | - Yeonho Choi
- Department
of Bio-convergence Engineering, Korea University, Seoul, 136-713, Korea
- School
of Biomedical Engineering, Korea University, Seoul, 136-713, Korea
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Moon SY, Nam J, Rathwell K, Kim WS. Copper-Catalyzed Chan–Lam Coupling between Sulfonyl Azides and Boronic Acids at Room Temperature. Org Lett 2014; 16:338-41. [DOI: 10.1021/ol403717f] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Soo-Yeon Moon
- Department of Chemistry and
Nano Science, Ewha Womans University, Global Top 5 Program, Seoul 120-750, Korea
| | - Jungsoo Nam
- Department of Chemistry and
Nano Science, Ewha Womans University, Global Top 5 Program, Seoul 120-750, Korea
| | - Kris Rathwell
- Department of Chemistry and
Nano Science, Ewha Womans University, Global Top 5 Program, Seoul 120-750, Korea
| | - Won-Suk Kim
- Department of Chemistry and
Nano Science, Ewha Womans University, Global Top 5 Program, Seoul 120-750, Korea
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Nam JS, Kim AR, Yoon JC, Byun Y, Kim SA, Kim KR, Cho S, Seong BL, Ahn CW, Lee JM. The humoral immune response to the inactivated influenza A (H1N1) 2009 monovalent vaccine in patients with Type 2 diabetes mellitus in Korea. Diabet Med 2011; 28:815-7. [PMID: 21672004 DOI: 10.1111/j.1464-5491.2011.03255.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS We evaluated the antibody response to a single-dose adjuvanted, inactivated, pandemic H1N1 influenza vaccination in patients with diabetes and assessed factors associated with the failure to induce antibody responses. METHODS Eighty-two patients with Type 2 diabetes were vaccinated and antibody responses were determined with haemagglutination inhibition assay and anti-haemagglutinin antibody ELISA. RESULTS Among 70 antibody-negative patients at baseline, 34 (48.6%) achieved seroconversion; 28 (60.9%) in the young adults group and six (25%) in the elderly group acquired H1N1-specific antibodies. Patients in the older age range or with longer duration of diabetes had a lower seroconversion rate. CONCLUSIONS Our data show low cross-reactive antibody carrying rate and low seroconversion rate in patients with diabetes. Until larger-scale, case-controlled trials become available, older patients and patients with a longer duration of diabetes should be considered for the two-dose vaccination or have antibody titres measured after the first vaccination.
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Affiliation(s)
- J S Nam
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
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Nam JS, Nam JY, Yoo JS, Cho M, Park JS, Ahn CW, Cha BS, Lee EJ, Lim SK, Kim KR, Lee HC. The effect of mosapride (5HT-4 receptor agonist) on insulin sensitivity and GLUT4 translocation. Diabetes Res Clin Pract 2010; 87:329-34. [PMID: 20060191 DOI: 10.1016/j.diabres.2009.12.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 12/09/2009] [Accepted: 12/15/2009] [Indexed: 01/08/2023]
Abstract
AIMS We investigated the effect of mosapride, 5HT-4 (5-hydroxytryptamine) agonist, on blood glucose level and insulin sensitivity in subjects with impaired glucose tolerance (IGT) and conducted an in vitro study to evaluate the action mechanism. METHODS Thirty IGT patients were randomly assigned to receive either mosapride or placebo for 2 weeks. Biochemical profiles and insulin sensitivity index from euglycemic hyperinsulinemic clamp test were assessed before and after treatment. In cultured myotubes from human skeletal muscle cells, insulin- and mosapride-induced GLUT4 translocation and tyrosine phosphorylation of IRS-1 were determined. RESULTS After 2 weeks of treatment with mosapride, glucose disposal rates were significantly increased up to those of control (mosapride 5.47+/-1.72 vs 7.06+/-2.13, P=0.004, placebo 5.42+/-1.85 vs 5.23+/-1.53mgkg(-1)min(-1)). Fasting plasma glucose (FPG) and insulin levels were decreased. Mosapride increased the contents of GLUT4 in plasma membrane representing the increased recruitment of glucose transporters from intracellular pool. While insulin treatment on human skeletal muscle cell resulted in an increased tyrosine phosphorylation of IRS-1, mosapride did not have any effect. CONCLUSIONS Mosapride is effective in decreasing FPG without stimulating insulin secretion in IGT subjects, possibly by inducing GLUT4 translocation in skeletal muscles.
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Affiliation(s)
- J S Nam
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
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Nam JS, Nam JY, Yoo JS, Cho M, Park JS, Ahn CW, Cha BS, Lee EJ, Lim SK, Kim KR, Lee HC. The effect of rosiglitazone on insulin sensitivity and mid-thigh low-density muscle in patients with Type 2 diabetes. Diabet Med 2010; 27:30-6. [PMID: 20121886 DOI: 10.1111/j.1464-5491.2009.02897.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS We examined the effect of rosiglitazone on insulin sensitivity, abdominal fat and mid-thigh intramuscular fat distribution, and plasma concentrations of adipocytokines in patients with Type 2 diabetes. METHODS Rosiglitazone was administered at a daily dose of 4 mg to 42 Type 2 diabetes patients [age 32-70 years, body mass index (BMI) 17.5-32.6 kg/m(2), 15 women, 27 men] for 12 weeks. Various anthropometric and metabolic profiles, plasma adiponectin, leptin, and resistin levels were measured, and insulin resistance was calculated from the short insulin tolerance test. Body fat composition was assessed by computed tomography. RESULTS Twelve weeks' rosiglitazone treatment resulted in improved insulin resistance despite increases in body weight and BMI. There was a significant decrease in abdominal visceral adipose tissue area (145 +/- 65.6 vs. 129 +/- 73.1 cm(2), P = 0.049). Mid-thigh low-density muscle area (TLDMA) increased from 23 +/- 9.6 to 26 +/- 8.2 cm(2) (P = 0.009). There were significant changes in plasma adipocytokines, but they were not significantly correlated with changes in insulin resistance. CONCLUSIONS Rosiglitazone treatment resulted in an improvement of insulin responsiveness in Type 2 diabetic subjects, which was associated with the redistribution of visceral and subcutaneous adipose tissue, an increase in TLDMA, and changes in serum adipocytokine levels. Further studies are needed to elucidate the insulin sensitizing mechanism of rosiglitazone on peripheral skeletal muscles.
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Affiliation(s)
- J S Nam
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
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Abstract
AIMS Low serum nerve growth factor (NGF) levels have been reported in patients with diabetic peripheral neuropathy (DPN), but the role of NGF in the development of neuropathy is unclear. Thus, we investigated the associations of serum NGF level and NGF receptor activity with the presence and severity of DPN. METHODS One hundred and thirty-six patients with Type 2 diabetes were included in this cross-sectional study. Serum NGF levels were measured by ELISA. Expressions of NGF receptors (TrkA and p75(NTR)) were measured by immunohistochemical staining. The presence and severity of DPN were assessed by neuropathy disability score (NDS) and by corneal nerve fibre length (cNFL) and nerve branch density (cNBD) using in vivo confocal microscopy. RESULTS Patients with DPN had higher serum NGF levels (56-451 pg/ml) than patients without DPN (4-54 pg/ml). However, in DPN patients, serum NGF was negatively associated with neuropathy severity (mild 222 +/- 64 pg/ml; moderate 114 +/- 17 pg/ml; severe 89 +/- 20 pg/ml). This negative association was consistent in all severity indices (NDS, P < 0.001; cNFL, P < 0.001; cNBD P = 0.010) even after adjustment for age, sex, diabetes duration, insulin use, fasting glucose and glycated haemoglobin. Although NGF receptor activities had significantly (P < 0.05) negative associations with the presence and severity of neuropathy, these associations were not significant when adjusted for other factors. CONCLUSIONS Serum NGF level was positively associated with the presence of DPN but negatively associated with neuropathy severity in DPN patients. The change in serum NGF might be a consequence of, rather than a contributor to, the early development of DPN.
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Affiliation(s)
- H C Kim
- Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea
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Nam JS, Park JS, Cho MH, Jee SH, Lee HS, Ahn CW, Lowe WL, Kim KR. The association between pulse wave velocity and metabolic syndrome and adiponectin in patients with impaired fasting glucose: cardiovascular risks and adiponectin in IFG. Diabetes Res Clin Pract 2009; 84:145-51. [PMID: 19261346 DOI: 10.1016/j.diabres.2009.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 01/29/2009] [Accepted: 02/03/2009] [Indexed: 01/19/2023]
Abstract
We aimed to assess how metabolic profiles, surrogate markers of insulin resistance, and subclinical atherosclerosis are interrelated in subjects with impaired fasting glucose (IFG) and investigate whether the diagnosis of metabolic syndrome (MetS) further increases the risk of cardiovascular disease among subjects already at risk. We analyzed 1739 Korean subjects with IFG. The parameters of MetS, plasma adiponectin level, and pulse wave velocity (PWV) were assessed. Subjects with MetS had unfavorable metabolic parameters, lower adiponectin level, and higher peripheral PWV compared to those without MetS. Adiponectin correlated with fasting glucose, waist circumference, triglyceride, HDL-cholesterol, BMI, HOMA-IR, and the number of MetS components. In addition to blood pressure, peripheral PWV was associated with triglyceride, waist circumference, and the number of MetS components while aortic PWV correlated positively with fasting plasma glucose. Multiple linear regression analysis revealed that adiponectin correlated with HDL-cholesterol, HOMA-IR, fasting glucose, waist circumference, and triglyceride, peripheral PWV with blood pressure, body mass index, waist circumference, and the number of MetS components, and aortic PWV with fasting plasma glucose. In subjects with IFG, concurrent MetS increases PWV and has an unfavorable effect on cardiovascular risks, and these risks were further increased by additional MetS components.
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Affiliation(s)
- J S Nam
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
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Kim CS, Song MK, Park JS, Cho MH, Kim HJ, Nam JS, Kang ES, Ahn CW, Cha BS, Lee EG, Lim SK, Kim KR, Lee HC, Huh KB. The clinical and immunogenetic characteristics of adult-onset type 1 diabetes mellitus in Korea. Acta Diabetol 2007; 44:45-54. [PMID: 17530466 DOI: 10.1007/s00592-007-0241-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Accepted: 12/27/2006] [Indexed: 11/28/2022]
Abstract
Although the HLA class II alleles and immunological abnormalities are associated with type 1 diabetes mellitus (T1DM) in all racial groups, there are considerable variations in the genotypes and the prevalence of autoantibodies. In order to investigate the characteristics of the immunogenetic patterns and to use these as an early diagnostic tool and guideline for a therapeutic plan, we examined the clinical characteristics and the patterns of anti-GAD antibody (GADA), IA-2 antibody (IA-2A), HLA-DR and HLA-DQ in Korean adult-onset T1DM patients. Adult-onset patients had higher serum C-peptide levels than child-onset patients. In adult-onset patients, the prevalence of GADA and IA-2A were 59.5% and 15.3% respectively, and increased frequencies of HLADR4 and-DR9 were found. The frequencies of HLADQA1,-DQB1 and-DQ heterodimers were similar to those of the control, but child-onset patients had high frequencies of the HLA-DR3,-DR4,-DR9, DQA1*0301, DQA1*0501 and DQB1*0201 genotypes. In conclusion, Korean adult-onset T1DM patients had a lower prevalence of GADA, which was comparable to that found in Caucasian patients. The detection of GADA might help to predict the insulin dependency of adult-onset diabetes. Difference in the frequencies of diabetes associated with HLA type suggests that there might be a heterogeneity in the pathogenesis of diabetes according to the age of onset.
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Affiliation(s)
- C S Kim
- Department of Internal Medicine, Yonsei University College of Medicine, 134 Shinchon-Dong, Seodaemun-Ku, Seoul, Korea
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Kang CH, Jung WY, Kang YH, Kim JY, Kim DG, Jeong JC, Baek DW, Jin JB, Lee JY, Kim MO, Chung WS, Mengiste T, Koiwa H, Kwak SS, Bahk JD, Lee SY, Nam JS, Yun DJ, Cho MJ. AtBAG6, a novel calmodulin-binding protein, induces programmed cell death in yeast and plants. Cell Death Differ 2006; 13:84-95. [PMID: 16003391 DOI: 10.1038/sj.cdd.4401712] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Calmodulin (CaM) influences many cellular processes by interacting with various proteins. Here, we isolated AtBAG6, an Arabidopsis CaM-binding protein that contains a central BCL-2-associated athanogene (BAG) domain. In yeast and plants, overexpression of AtBAG6 induced cell death phenotypes consistent with programmed cell death (PCD). Recombinant AtBAG6 had higher affinity for CaM in the absence of free Ca2 + than in its presence. An IQ motif (IQXXXRGXXXR, where X denotes any amino-acid) was required for Ca2 +-independent CaM complex formation and single amino-acid changes within this motif abrogated both AtBAG6-activated CaM-binding and cell death in yeast and plants. A 134-amino-acid stretch, encompassing both the IQ motif and BAG domain, was sufficient to induce cell death. Agents generating oxygen radicals, which are known to be involved in plant PCD, specifically induced the AtBAG6 transcript. Collectively, these results suggest that AtBAG6 is a stress-upregulated CaM-binding protein involved in plant PCD.
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Affiliation(s)
- C H Kang
- Division of Applied Life Science (BK21 program) and Environmental Biotechnology National Core Research Center, Graduate School of Gyeongsang National University, Jinju 660-701, Korea
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Kim JK, Huh SO, Choi H, Lee KS, Shin D, Lee C, Nam JS, Kim H, Chung H, Lee HW, Park SD, Seong RH. Srg3, a mouse homolog of yeast SWI3, is essential for early embryogenesis and involved in brain development. Mol Cell Biol 2001; 21:7787-95. [PMID: 11604513 PMCID: PMC99948 DOI: 10.1128/mcb.21.22.7787-7795.2001] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2001] [Accepted: 08/15/2001] [Indexed: 11/20/2022] Open
Abstract
Srg3 (SWI3-related gene product) is a mouse homolog of yeast SWI3, Drosophila melanogaster MOIRA (also named MOR/BAP155), and human BAF155 and is known as a core subunit of SWI/SNF complex. This complex is involved in the chromatin remodeling required for the regulation of transcriptional processes associated with development, cellular differentiation, and proliferation. We generated mice with a null mutation in the Srg3 locus to examine its function in vivo. Homozygous mutants develop in the early implantation stage but undergo rapid degeneration thereafter. An in vitro outgrowth study revealed that mutant blastocysts hatch, adhere, and form a layer of trophoblast giant cells, but the inner cell mass degenerates after prolonged culture. Interestingly, about 20% of heterozygous mutant embryos display defects in brain development with abnormal organization of the brain, a condition known as exencephaly. Histological examination suggests that exencephaly is caused by the failure in neural fold elevation, resulting in severe brain malformation. Our findings demonstrate that Srg3 is essential for early embryogenesis and plays an important role in the brain development of mice.
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Affiliation(s)
- J K Kim
- School of Biological Sciences and Institute of Molecular Biology and Genetics, Seoul National University, Kwanak-gu, Shinlim-dong, Seoul 151-742, Republic of Korea
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Chung YR, Sung KC, Mo HK, Son DY, Nam JS, Chun J, Bae KS. Kitasatospora cheerisanensis sp. nov., a new species of the genus Kitasatospora that produces an antifungal agent. Int J Syst Bacteriol 1999; 49 Pt 2:753-8. [PMID: 10319499 DOI: 10.1099/00207713-49-2-753] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An actinomycete, strain YC75T, which produced bafilomycin-like antifungal compounds, was identified as a member of the genus Kitasatospora on the basis of morphological and chemotaxonomic characteristics. The strain produced the aerial and fragmenting vegetative mycelia consisting of straight chains of 20 or more smooth-surfaced spores. Submerged spores were formed in tryptic soy broth. No soluble pigments were formed. Whole-cell hydrolysates contained glucose and mannose, but not galactose. The 16S rDNA sequence of YC75T was compared with those of the other representative kitasatosporae and streptomycetes. Strain YC75T formed a significant monophyletic clade with Kitasatospora phosalacinea. The levels of DNA relatedness between strain YC75T and representatives of the genus Kitasatospora ranged from 16 to 59% including K. phosalacinea (28 and 40%). It is clear from polyphasic evidence that the isolate should be classified as Kitasatospora cheerisanensis sp. nov., whose type strain is YC75T (= KCTC 2395T). The presence of galactose in whole-cell hydrolysates may not be a stable chemical marker for the genus Kitasatospora.
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Affiliation(s)
- Y R Chung
- Department of Microbiology, Gyeongsang National University, Chinju, Republic of Korea.
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Nam JS, Lee DH, Lee KH, Park HM, Bae KS. Cloning and phylogenetic analysis of chitin synthase genes from the insect pathogenic fungus, Metarhizium anisopliae var. anisopliae. FEMS Microbiol Lett 1998; 159:77-84. [PMID: 9485597 DOI: 10.1111/j.1574-6968.1998.tb12844.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Degenerated PCR primers were used to amplify chitin synthase genes from genomic DNA of Metarhizium anisopliae var. anisopliae. Through cloning and sequencing of approximately 600-bp fragments amplified by PCR, we found three genes encoding different types of chitin synthases, designated MaCHS1, MaCHS2, and MaCHS3. Southern blot analysis performed on genomic DNA showed that each of the chitin synthases MaCHS1, MaCHS2, and MaCHS3 is encoded by a single copy gene. Alignment of their deduced amino acid sequences with those of other euascomycetes separated the sequences into three distinct classes. MaCHS1 was identified as a gene for class I chitin synthase, MaCHS2 for class II, and MaCHS3 for class III. The UPGMA dendrogram and phylogenetic tree of the deduced amino acid sequences revealed the taxonomic and evolutionary position of Metarhizium anisopliae var. anisopliae.
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Affiliation(s)
- J S Nam
- Genetic Resources Center, KRIBB, Taejon, South Korea
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15
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Kim JS, Nam JS, Chae HD, Kim KT. A protein kinase C-activating phorbol ester enhances transcription of the human DBH gene through a cyclic AMP response element in SK-N-BE(2)C cells. Brain Res Mol Brain Res 1997; 51:154-60. [PMID: 9427517 DOI: 10.1016/s0169-328x(97)00227-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Protein kinase C (PKC) activation after treatment of human neuroblastoma SK-N-BE(2)C cells with phorbol 12-myristate 13-acetate (PMA) was found to enhance transcription of the human dopamine beta-hydroxylase (DBH) in those cells. To identify which cis-acting element is responsive to the PMA treatment during DBH gene expression, we employed transient transfection assays with serially deleted constructs of the human DBH gene's 5' upstream region fused to the chloramphenicol acetyltransferase (CAT) gene. Treatment of transfected cells with PMA resulted in an approximate threefold increase in CAT expression for all deletion constructs ranging from -978 bp to -262 bp, while the enhancement did not occur with a construct shortened to -114 bp. The region between -262 and -114 bp from the initiation site of transcription contains several cis-regulatory elements including a cyclic AMP response element (CRE) and putative AP1 and YY1 sequences. Site-directed mutagenesis of those cis-acting elements were performed to identify which of the elements mediated the PMA-induced transcriptional enhancement. Substitution of bases in the putative AP1 site containing in part a putative YY1 sequence did not effect the PMA inducibility. However, specific mutations in the CRE sequence abolished the PMA-inducible effect. Changing the CRE sequence into an authentic AP1 sequence (TGACGTCC --> TGACTCA) did not affect the PMA inducibility, suggesting that AP1 factors might interact with the new AP1 site upon PKC activation. A specific PKC inhibitor, GF109203X, completely inhibited the stimulatory effect of PMA on the expression of the human DBH gene. PMA induced an increase in the DBH mRNA level as detected by Northern blot analysis. Gel retardation showed that the binding of nuclear factors to CRE, putative YY1, and AP1 was sequence specific. Our data suggest that the enhancement of the human DBH gene expression by PMA treatment is mediated by the CRE motif in the 5' upstream region of the gene, and occurs via a PKC-dependent pathway.
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Affiliation(s)
- J S Kim
- Department of Life Science, Pohang University of Science and Technology, POSTECH, South Korea
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Nam JS, Kwon GS, Lee SO, Hwang JS, Lee JD, Yoon BD, Lee TH. Bioflocculant produced by Aspergillus sp. JS-42. Biosci Biotechnol Biochem 1996; 60:235-7. [PMID: 9063970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A bioflocculant from a fungus, Aspergillus sp. JS-42, was purified by precipitations with acetone and cetylpyridinium chloride. The flocculating activity was not significantly affected by pH from 3 to 8, but was stimulated by the addition of CaCl2, and was effective only when the reaction mixture contained an adequate amount of flocculant. The flocculant could efficiently flocculate all tested solids suspended in aqueous solution, including various microorganisms, organic acids, and inorganic materials.
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Affiliation(s)
- J S Nam
- Department of Microbiology, College of Natural Sciences, Pusan National University, Korea
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