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Fu Y, Huang SS, Wang QQ, Han MY, Wang GJ, Kang DY, Dai P, Yuan YY. [Using PGT to give birth to hereditary conductive deafness SYNS1 family a healthy offspring: a case report]. Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2024; 59:243-248. [PMID: 38561263 DOI: 10.3760/cma.j.cn115330-20230925-00116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Affiliation(s)
- Y Fu
- National Clinical Research Center for Otolaryngologic Diseases, College of Otolaryngology-Head and Neck Surgery, Sixth Medical Center of the PLA General Hospital, Beijing 100037, China Department of Otorhinolaryngology, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, Qingdao 266035, China
| | - S S Huang
- National Clinical Research Center for Otolaryngologic Diseases, College of Otolaryngology-Head and Neck Surgery, Sixth Medical Center of the PLA General Hospital, Beijing 100037, China
| | - Q Q Wang
- National Clinical Research Center for Otolaryngologic Diseases, College of Otolaryngology-Head and Neck Surgery, Sixth Medical Center of the PLA General Hospital, Beijing 100037, China
| | - M Y Han
- National Clinical Research Center for Otolaryngologic Diseases, College of Otolaryngology-Head and Neck Surgery, Sixth Medical Center of the PLA General Hospital, Beijing 100037, China
| | - G J Wang
- National Clinical Research Center for Otolaryngologic Diseases, College of Otolaryngology-Head and Neck Surgery, Sixth Medical Center of the PLA General Hospital, Beijing 100037, China
| | - D Y Kang
- National Clinical Research Center for Otolaryngologic Diseases, College of Otolaryngology-Head and Neck Surgery, Sixth Medical Center of the PLA General Hospital, Beijing 100037, China
| | - P Dai
- National Clinical Research Center for Otolaryngologic Diseases, College of Otolaryngology-Head and Neck Surgery, Sixth Medical Center of the PLA General Hospital, Beijing 100037, China
| | - Y Y Yuan
- National Clinical Research Center for Otolaryngologic Diseases, College of Otolaryngology-Head and Neck Surgery, Sixth Medical Center of the PLA General Hospital, Beijing 100037, China
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Yang JY, Wang QQ, Han MY, Huang SS, Kang DY, Zhang X, Yang SY, Dai P, Yuan YY. [Phenotype-genotype analysis of the autosomal recessive hereditary hearing loss caused by OTOA variations]. Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2023; 58:460-469. [PMID: 37114731 DOI: 10.3760/cma.j.cn115330-20220620-00361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Objective: To analyze the phenotypic-genotypic characteristics of hereditary deafness caused by OTOA gene variations. Methods: Family histories, clinical phenotypes and gene variations of six pedigrees were analyzed, which were diagnosed with hearing loss caused by OTOA gene variations at the PLA General Hospital from September 2015 to January 2022. The sequence variations were verified by Sanger sequencing and the copy number variations were validated by multiplex ligation-dependent probe amplification (MLPA) in the family members. Results: The hearing loss phenotype caused by OTOA variations ranged from mild to moderate in the low frequencies, and from moderate to severe in the high frequencies in the probands, which came from six sporadic pedigrees, among which a proband was diagnosed as congenital deafness and five were diagnosed as postlingual deafness. One proband carried homozygous variations and five probands carried compound heterozygous variations in OTOA gene. Nine pathogenic variations (six copy number variations, two deletion variations and one missense variation) and two variations with uncertain significance in OTOA were identified in total, including six copy number variations and five single nucleotide variants, and three of the five single nucleotide variants were firstly reported [c.1265G>T(p.Gly422Val),c.1534delG(p.Ala513Leufs*11) and c.3292C>T(p.Gln1098fs*)]. Conclusions: OTOA gene variations can lead to autosomal recessive nonsyndromic hearing loss. In this study, the hearing loss caused by OTOA defects mostly presents as bilateral, symmetrical, and postlingual, and that of a few presents as congenital. The pathogenic variations of OTOA gene are mainly copy number variations followed by deletion variations and missense variations.
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Affiliation(s)
- J Y Yang
- Department of Otomicrosurgery, College of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Otolaryngologic Diseases, Beijing 100048, China
| | - Q Q Wang
- Department of Otomicrosurgery, College of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Otolaryngologic Diseases, Beijing 100048, China
| | - M Y Han
- Department of Otomicrosurgery, College of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Otolaryngologic Diseases, Beijing 100048, China
| | - S S Huang
- Department of Otomicrosurgery, College of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Otolaryngologic Diseases, Beijing 100048, China
| | - D Y Kang
- Department of Otomicrosurgery, College of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Otolaryngologic Diseases, Beijing 100048, China
| | - X Zhang
- Department of Otomicrosurgery, College of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Otolaryngologic Diseases, Beijing 100048, China
| | - S Y Yang
- Department of Otomicrosurgery, College of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Otolaryngologic Diseases, Beijing 100048, China
| | - P Dai
- Department of Otomicrosurgery, College of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Otolaryngologic Diseases, Beijing 100048, China
| | - Y Y Yuan
- Department of Otomicrosurgery, College of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Otolaryngologic Diseases, Beijing 100048, China
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Sung M, Kim DH, Jee HM, Kim JH, Ha EK, Shin YH, Han MY. Urine phthalate levels were associated with skin barrier dysfunction and atopic sensitization in children. Eur Rev Med Pharmacol Sci 2023; 27:2888-2898. [PMID: 37070889 DOI: 10.26355/eurrev_202304_31920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
OBJECTIVE Phthalates can cause immunological disorders and aggravate allergic diseases. Thus, we investigated the relationship between urinary phthalate, skin barrier function, and atopic sensitization in children. PATIENTS AND METHODS In total, 448 school children [334 with severe allergic disease; and 123 with severe atopic dermatitis (AD)] aged 10-12 years were enrolled in this study between June and July 2017. Four high-molecular-weight phthalates (HMWP) [Σ4HMWP] and three low-molecular-weight phthalates (LMWP) [Σ3LMWP] metabolites in urine samples, specific immunoglobulin E (IgE), and total eosinophil count were measured. Four-part trans epidermal water loss (TEWL) (cheek, leg, and upper/lower arm; Σ4TEWL) was measured to evaluate the skin barrier function. RESULTS After adjusting for confounding variables, Σ4TEWL was significantly associated with the quartiles of urinary Σ4HMWP [adjusted β=7.897, 95% confidence interval (CI): 0.636-15.158, p=0.033] and Σ3LMWP (adjusted β=9.670, 95% CI: 2.422-16.919, p=0.009). The adjusted analyses revealed that the quartiles of urinary Σ4HMWP and Σ3LMWP were not significantly associated with total eosinophil count, atopic sensitization, and severe AD (p>0.05). According to the quartiles of urinary Σ4HMWP and Σ3LMWP, there were significant differences in the TEWL of the lower arm and leg (p<0.05) but not in cheek and upper arm. CONCLUSIONS Exposure to HMWPs and LMWPs was significantly associated with skin barrier dysfunction but not with atopic sensitization. These results suggest that children exposed to phthalates may be more susceptible to fragile skin barrier function.
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Affiliation(s)
- M Sung
- Department of Pediatrics, Soonchunhyang University Gumi Hospital, Gumi, Republic of Korea.
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Sung M, Jee HM, Kim JH, Ha EK, Shin YH, Kim JH, Lim DH, Han MY. Serum vitamin D level mitigates fractional exhaled nitric oxide linked to bisphenol-A in school-aged children. Eur Rev Med Pharmacol Sci 2022; 26:1640-1647. [PMID: 35302211 DOI: 10.26355/eurrev_202203_28232] [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] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
OBJECTIVE Previous studies on the relationship of bisphenol-A (BPA) with fractional exhaled nitric oxide (FeNO) had conflicting results, suggesting that other factors may modulate this relationship. Thus, we investigated the modulating effect of vitamin D on the relationship of BPA with FeNO in children. PATIENTS AND METHODS This study recruited 432 children (10 to 12 years old) from the general pediatric population of Korea between June and July 2017. We conducted measurements of urinary BPA, serum vitamin D, specific serum IgE, FeNO, and data from impulse oscillometry (reactance area [AX], airway resistance at 5 Hz [Rrs5] and 20 Hz [Rrs10], and the difference of Rrs5 and Rrs20 [Rrs5-20]). RESULTS Serum vitamin D (adjusted β =- 0.014, p=0.002) and urinary BPA (β = 0.006, p<0.001) level was significantly associated with FeNO. Urinary BPA level was significantly associated with FeNO in children with low vitamin D levels (≤23 ng/mL; αβ = 0.006, p < 0.001), but not in children with high vitamin D levels (>23 ng/mL). The interaction of vitamin D and BPA had a significant effect on FeNO (pint = 0.005). There was no relationship with the airway lung function (Rrs5, AX, and Rrs5-20) to serum vitamin D and urinary BPA level. Vitamin D ameliorated the BPA-mediated increase of FeNO in children. CONCLUSIONS These results suggest that children with low vitamin D levels may be more susceptible to airway inflammation due to BPA.
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Affiliation(s)
- M Sung
- Department of Pediatrics, Soonchunhyang University Gumi Hospital, Gumi, Republic of Korea.
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Yon DK, Lee SW, Ha EK, Lee KS, Jung YH, Jee HM, Kim MA, Ahn JC, Sheen YH, Han MY. Serum lipid levels are associated with allergic rhinitis, nasal symptoms, peripheral olfactory function, and nasal airway patency in children. Allergy 2018; 73:1905-1908. [PMID: 29786875 DOI: 10.1111/all.13484] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D. K. Yon
- Department of Pediatrics; CHA Bundang Medical Center; CHA University School of Medicine; Seongnam Korea
| | - S. W. Lee
- Department of Pediatrics; CHA Bundang Medical Center; CHA University School of Medicine; Seongnam Korea
| | - E. K. Ha
- Department of Pediatrics; CHA Bundang Medical Center; CHA University School of Medicine; Seongnam Korea
| | - K. S. Lee
- Department of Pediatrics; CHA Bundang Medical Center; CHA University School of Medicine; Seongnam Korea
| | - Y.-H. Jung
- Department of Pediatrics; CHA Bundang Medical Center; CHA University School of Medicine; Seongnam Korea
| | - H. M. Jee
- Department of Pediatrics; CHA Bundang Medical Center; CHA University School of Medicine; Seongnam Korea
| | - M. A. Kim
- Department of Internal Medicine; CHA Bundang Medical Center; CHA University School of Medicine; Seongnam Korea
| | - J.-C. Ahn
- Department of Otorhinolaryngology-Head and Neck Surgery; CHA Bundang Medical Center; CHA University School of Medicine; Seongnam Korea
| | - Y. H. Sheen
- Department of Pediatrics; CHA Gangnam Medical Center; CHA University School of Medicine; Seoul Korea
| | - M. Y. Han
- Department of Pediatrics; CHA Bundang Medical Center; CHA University School of Medicine; Seongnam Korea
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Sheen YH, Jee HM, Kim DH, Ha EK, Jeong IJ, Lee SJ, Baek HS, Lee SW, Lee K, Lee KS, Jung Y, Sung M, Kim MA, Han MY. Serum zonulin is associated with presence and severity of atopic dermatitis in children, independent of total IgE and eosinophil. Clin Exp Allergy 2018; 48:1059-1062. [DOI: 10.1111/cea.13158] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Y. H. Sheen
- Department of Pediatrics CHA Gangnam Medical Center CHA University Seoul Korea
| | - H. M. Jee
- Department of Pediatrics CHA Bundang Medical Center CHA University Seongnam Korea
| | - D. H. Kim
- Department of Dermatology CHA Bundang Medical Center CHA University Seongnam Korea
| | - E. K. Ha
- Department of Pediatrics CHA Bundang Medical Center CHA University Seongnam Korea
| | - I. J. Jeong
- Department of Dermatology CHA Bundang Medical Center CHA University Seongnam Korea
| | - S. J. Lee
- Department of Pediatrics CHA Bundang Medical Center CHA University Seongnam Korea
| | - H. S. Baek
- Department of Pediatrics Hallym University Kangdong Sacred Heart Hospital Hallym University College of Medicine Seoul Korea
| | | | - K.‐J. Lee
- Department of Information and Statistics Korea National Open University Seoul Korea
| | - K. S. Lee
- Department of Pediatrics CHA Bundang Medical Center CHA University Seongnam Korea
| | - Y.‐H. Jung
- Department of Pediatrics CHA Bundang Medical Center CHA University Seongnam Korea
| | - M. Sung
- Department of Pediatrics Inje University Haeundae Paik Hospital Busan Korea
| | - M. A. Kim
- Department of Internal Medicine CHA Bundang Medical Center CHA University Seongnam Korea
| | - M. Y. Han
- Department of Pediatrics CHA Bundang Medical Center CHA University Seongnam Korea
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Chen B, Han MY, Peng K, Zhou SL, Shao L, Wu XF, Wei WD, Liu SY, Li Z, Li JS, Chen GQ. Global land-water nexus: Agricultural land and freshwater use embodied in worldwide supply chains. Sci Total Environ 2018; 613-614:931-943. [PMID: 28946381 DOI: 10.1016/j.scitotenv.2017.09.138] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 09/13/2017] [Accepted: 09/14/2017] [Indexed: 06/07/2023]
Abstract
As agricultural land and freshwater inextricably interrelate and interact with each other, the conventional water and land policy in "silos" should give way to nexus thinking when formulating the land and water management strategies. This study constructs a systems multi-regional input-output (MRIO) model to expound global land-water nexus by simultaneously tracking agricultural land and freshwater use flows along the global supply chains. Furthermore, land productivity and irrigation water requirements of 160 crops in different regions are investigated to reflect the land-water linkage. Results show that developed economies (e.g., USA and Japan) and major large developing economies (e.g., mainland China and India) are the overriding drivers of agricultural land and freshwater use globally. In general, significant net transfers of these two resources are identified from resource-rich and less-developed economies to resource-poor and more-developed economies. For some crops, blue water productivity is inversely related to land productivity, indicating that irrigation water consumption is sometimes at odds with land use. The results could stimulus international cooperation for sustainable land and freshwater management targeting on original suppliers and final consumers along the global supply chains. Moreover, crop-specific land-water linkage could provide insights for trade-off decisions on minimizing the environmental impacts on local land and water resources.
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Affiliation(s)
- B Chen
- Laboratory of Systems Ecology and Sustainability Science, College of Engineering, Peking University, Beijing 100871, China
| | - M Y Han
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, PR China
| | - K Peng
- Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China
| | - S L Zhou
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, PR China
| | - L Shao
- School of Humanities and Economic Management, China University of Geosciences, Beijing 100083, People's Republic of China
| | - X F Wu
- Economics School, Zhongnan University of Economics and Law, Wuhan 430073, China
| | - W D Wei
- Business School, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - S Y Liu
- Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control, Yanshan University, Qinhuangdao 066004, PR China
| | - Z Li
- Laboratory of Systems Ecology and Sustainability Science, College of Engineering, Peking University, Beijing 100871, China
| | - J S Li
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, PR China; Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
| | - G Q Chen
- Laboratory of Systems Ecology and Sustainability Science, College of Engineering, Peking University, Beijing 100871, China.
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Abstract
We report remarkable photovoltaic effect in YBa2Cu3O6.96 (YBCO) ceramic between 50 and 300 K induced by blue-laser illumination, which is directly related to the superconductivity of YBCO and the YBCO-metallic electrode interface. There is a polarity reversal for the open circuit voltage Voc and short circuit current Isc when YBCO undergoes a transition from superconducting to resistive state. We show that there exists an electrical potential across the superconductor-normal metal interface, which provides the separation force for the photo-induced electron-hole pairs. This interface potential directs from YBCO to the metal electrode when YBCO is superconducting and switches to the opposite direction when YBCO becomes nonsuperconducting. The origin of the potential may be readily associated with the proximity effect at metal-superconductor interface when YBCO is superconducting and its value is estimated to be ~10–8 mV at 50 K with a laser intensity of 502 mW/cm2. Combination of a p-type material YBCO at normal state with an n-type material Ag-paste forms a quasi-pn junction which is responsible for the photovoltaic behavior of YBCO ceramics at high temperatures. Our findings may pave the way to new applications of photon-electronic devices and shed further light on the proximity effect at the superconductor-metal interface.
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Affiliation(s)
- F Yang
- 1] College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007, P. R. China [2] Henan Key Laboratory of Photovoltaic Materials, Xinxiang 453007, P. R. China
| | - M Y Han
- 1] College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007, P. R. China [2] Henan Key Laboratory of Photovoltaic Materials, Xinxiang 453007, P. R. China
| | - F G Chang
- 1] College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007, P. R. China [2] Henan Key Laboratory of Photovoltaic Materials, Xinxiang 453007, P. R. China
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Hahm MI, Chae Y, Kwon HJ, Kim J, Ahn K, Kim WK, Lee SY, Park YM, Han MY, Lee KJ, Lee HY, Min I. Do newly built homes affect rhinitis in children? The ISAAC phase III study in Korea. Allergy 2014; 69:479-87. [PMID: 24428419 DOI: 10.1111/all.12355] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND As Korea has experienced rapid economic development, the lifestyles of Koreans have become more Westernized, in terms of urbanization and dietary habits. Also, the prevalences of allergic diseases, such as rhinitis, asthma, and dermatitis, have increased rapidly. This study aimed to identify the factors influencing the symptoms of rhinitis conditions, including rhinitis, allergic rhinitis, overlapped rhinitis, and overlapped allergic rhinitis, among Korean children aged 6-7 years. METHODS The study subjects were drawn from participants in the International Study of Asthma and Allergies in Childhood (ISAAC) study in 2010 and were aged 6-7 years. We analysed data for a total of 3804 children. RESULTS The prevalences of symptoms suggestive of rhinitis and allergic rhinitis in the previous 12 months were 43.4% and 22.1%, respectively. For overlapped rhinitis and overlapped allergic rhinitis, only 2.5% and 1.9% of the children had overlapping symptoms, having rhinitis with asthma and eczema simultaneously. Gender, a parental history of allergic disease, mould or dampness at home, and the risk factors for 'sick building syndrome' (SBS) were risk factors influencing rhinitis diseases. In particular, a history of moving to a newly built home in the child's infancy was strongly associated with symptoms of all the rhinitis diseases examined. CONCLUSIONS This study identified patterns of the prevalence of rhinitis conditions among Korean children that were similar to those reported in Western countries. We confirmed that a history of moving to a newly built home during infancy was associated with a considerable risk of rhinitis conditions.
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Affiliation(s)
- M.-I. Hahm
- Department of Health Administration and Management; College of Medical Science; Soonchunhyang University; Asan Korea
| | - Y. Chae
- Department of Occupational and Environmental Medicine; Dankook University Hospital; Cheonan Korea
| | - H.-J. Kwon
- Department of Preventive Medicine; Dankook University College of Medicine; Cheonan Korea
| | - J. Kim
- Department of Pediatrics; Samsung Medical Center; Environmental Health Center for Atopic Diseases; Sungkyunkwan University School of Medicine; Seoul Korea
| | - K. Ahn
- Department of Pediatrics; Samsung Medical Center; Environmental Health Center for Atopic Diseases; Sungkyunkwan University School of Medicine; Seoul Korea
| | - W.-K. Kim
- Department of Pediatrics; Inje University College of Medicine; Seoul Korea
| | - S.-Y. Lee
- Department of Pediatrics; Hallym Sacred Heart Hospital; Hallym University College of Medicine; Anyang Korea
| | - Y. M. Park
- Department of Pediatrics; Konkuk University Hospital; Konkuk University School of Medicine; Seoul Korea
| | - M. Y. Han
- Department of Pediatrics; CHA University School of Medicine; Seongnam Korea
| | - K.-J. Lee
- Department of Information and Statistics; Korea National Open University; Seoul Korea
| | - H.-Y. Lee
- Department of Social Medicine; Dankook University College of Medicine; Cheonan Korea
| | - I. Min
- Department of Health Administration and Management; College of Medical Science; Soonchunhyang University; Asan Korea
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Amin MT, Kim TI, Amin MN, Han MY. Effects of catchment, first-flush, storage conditions, and time on microbial quality in rainwater harvesting systems. Water Environ Res 2013; 85:2317-2329. [PMID: 24597047 DOI: 10.2175/106143013x13706200598433] [Citation(s) in RCA: 9] [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] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Rainwater collected from a rooftop rainwater harvesting (RWH) system is typically not considered suitable for potable uses, primarily because of poor microbial quality. The quality of stored rainwater, however, can be improved through basic design and maintenance practices during the construction and operation of an RWH system. This paper presents the microbial analysis of rainwater in two RWH systems installed at the Seoul National University Campus in South Korea. Rainwater samples were collected at different locations within each system and analyzed for total and fecal coliforms, Escherichia coli, and heterotrophic plate count bacteria. Within their storage tanks, water quality improved horizontally from inlet to outlet points, and higher quality was observed at the supply point (located about 0.5 m from the base of the tank) than at the surface or bottom of the tank. First-flush rainwater was found to be highly contaminated but rainwater quality improved following about 1 mm of precipitation. The catchment surface also had a significant effect on the quality of rainwater; samples collected from a rooftop exhibited better microbial quality than from a terrace catchment. Better water quality in underground tanks (dark storage conditions) compared to open weirs/ filters (exposed to natural light) demonstrated the importance of storage conditions. Water quality also improved with longer storage, and a decrease of 70% to 90% in microbial concentrations was observed after about 1 week of storage time. The findings of this study demonstrate that the microbial quality of harvested rainwater can be improved significantly by the adoption of proper design and maintenance guidelines such as those discussed in this paper.
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Affiliation(s)
- M T Amin
- Alamoudi Water Chair, King Saud University, Riyadh 11451, Kingdom of Saudi Arabia
| | - Tschung-il Kim
- Civil and Environmental Engineering Department, Seoul National University, South Korea
| | - M N Amin
- Department of Civil and Environmental Engineering, College of Engineering, King Faisal University, Al-Hofuf, Al-Ahsa 31982, Kingdom of Saudi Arabia
| | - M Y Han
- Civil and Environmental Engineering Department, Seoul National University, South Korea
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Lee JY, Moon HJ, Kim TI, Kim HW, Han MY. Quantitative analysis on the urban flood mitigation effect by the extensive green roof system. Environ Pollut 2013; 181:257-261. [PMID: 23892044 DOI: 10.1016/j.envpol.2013.06.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 06/25/2013] [Accepted: 06/27/2013] [Indexed: 06/02/2023]
Abstract
Extensive green-roof systems are expected to have a synergetic effect in mitigating urban runoff, decreasing temperature and supplying water to a building. Mitigation of runoff through rainwater retention requires the effective design of a green-roof catchment. This study identified how to improve building runoff mitigation through quantitative analysis of an extensive green-roof system. Quantitative analysis of green-roof runoff characteristics indicated that the extensive green roof has a high water-retaining capacity response to rainfall of less than 20 mm/h. As the rainfall intensity increased, the water-retaining capacity decreased. The catchment efficiency of an extensive green roof ranged from 0.44 to 0.52, indicating reduced runoff comparing with efficiency of 0.9 for a concrete roof. Therefore, extensive green roofs are an effective storm water best-management practice and the proposed parameters can be applied to an algorithm for rainwater-harvesting tank design.
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Affiliation(s)
- J Y Lee
- KIST (Korea Institute of Science and Technology), Gangneung Institute, Gangnueng 210-340, South Korea.
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Han MY, Dai JJ, Zhang Y, Lin Q, Jiang M, Xu XY, Liu Q. Identification of osteoarthritis biomarkers by proteomic analysis of synovial fluid. J Int Med Res 2013; 40:2243-50. [PMID: 23321181 DOI: 10.1177/030006051204000622] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE To use proteomic analysis to identify novel candidate biomarker proteins in synovial fluid for the differential diagnosis of osteoarthritis and rheumatoid arthritis. METHODS Synovial fluid samples were analysed using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Data were used to generate an artificial neural network (ANN). The identification of one protein peak was confirmed via Western blotting. RESULTS Fluid samples were analysed from 36 patients with osteoarthritis and 24 with rheumatoid arthritis. In total, three protein peaks (mass-to-charge ratio [m/z] 3893, 10,576 and 14,175 Da) were identified as potential biomarkers for osteoarthritis. The ANN differentiated between osteoarthritis and rheumatoid arthritis with a sensitivity of 89.4% and a specificity of 91.2%. The protein peak at m/z 10 576 was identified as S100 calcium binding protein A12 (S100A12). CONCLUSIONS A combination of SELDI-TOF-MS and ANN identified osteoarthritis biomarkers. SELDI-TOF-MS may be a useful tool in the screening of synovial fluid for osteoarthritis diagnosis.
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Affiliation(s)
- M Y Han
- Cancer Therapy and Research Centre, Shandong Provincial Hospital, Shandong University, Jinan Province, China
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Nawaz M, Han MY, Kim TI, Manzoor U, Amin MT. Silver disinfection of Pseudomonas aeruginosa and E. coli in rooftop harvested rainwater for potable purposes. Sci Total Environ 2012; 431:20-25. [PMID: 22664534 DOI: 10.1016/j.scitotenv.2012.05.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 04/30/2012] [Accepted: 05/07/2012] [Indexed: 06/01/2023]
Abstract
Rainwater harvesting being an alternate source in water scarce areas is becoming a common practice. Catchment contact, however, deteriorates the quality of rainwater making it unfit for potable purposes. To improve the quality of harvested rainwater, silver was used as antimicrobial agent in this study. Rainwater samples were taken from underground storage tank of a rooftop rainwater harvesting system installed in one of the buildings at Seoul National University, Seoul, South Korea. The target microorganisms (MOs) were Pseudomonas aeruginosa and Escherichia coli which were measured by using plate count method and standard MPN method, respectively. The efficiency of silver disinfection was evaluated at concentrations, ranging from 0.01 to 0.1 mg/l; the safe limit approved by WHO. The experiments were performed for 168 h with different time intervals to evaluate the parameters including inactivation rate, residual effect of silver and re-growth in both MOs at lower (i.e. 0.01-0.04 mg/l) as well as the higher concentrations of silver (i.e. 0.08-0.1 mg/l). Results showed the re-growth in both MOs was only in the case of lower concentrations of silver. The possible reason of re-growth at these concentrations of silver may be the halting of bacterial cell replication process for some time without permanent damage. The kinetics of this study suggest that higher inactivation and long term residual effect towards both MOs can be achieved with the application of silver at 0.08 mg/l or higher under safe limit.
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Affiliation(s)
- M Nawaz
- Alamoudi Water Chair, King Saud University, P.O. Box 2460, Riyadh, 11451, Saudi Arabia
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14
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Mun JS, Han MY. Design and operational parameters of a rooftop rainwater harvesting system: definition, sensitivity and verification. J Environ Manage 2012; 93:147-153. [PMID: 22054581 DOI: 10.1016/j.jenvman.2011.08.024] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 08/01/2011] [Accepted: 08/17/2011] [Indexed: 05/31/2023]
Abstract
The appropriate design and evaluation of a rainwater harvesting (RWH) system is necessary to improve system performance and the stability of the water supply. The main design parameters (DPs) of an RWH system are rainfall, catchment area, collection efficiency, tank volume and water demand. Its operational parameters (OPs) include rainwater use efficiency (RUE), water saving efficiency (WSE) and cycle number (CN). The sensitivity analysis of a rooftop RWH system's DPs to its OPs reveals that the ratio of tank volume to catchment area (V/A) for an RWH system in Seoul, South Korea is recommended between 0.03 and 0.08 in terms of rate of change in RUE. The appropriate design value of V/A is varied with D/A. The extra tank volume up to V/A of 0.15∼0.2 is also available, if necessary to secure more water. Accordingly, we should figure out suitable value or range of DPs based on the sensitivity analysis to optimize design of an RWH system or improve operation efficiency. The operational data employed in this study, which was carried out to validate the design and evaluation method of an RWH system, were obtained from the system in use at a dormitory complex at Seoul National University (SNU) in Korea. The results of these operational data are in good agreement with those used in the initial simulation. The proposed method and the results of this research will be useful in evaluating and comparing the performance of RWH systems. It is found that RUE can be increased by expanding the variety of rainwater uses, particularly in the high rainfall season.
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Affiliation(s)
- J S Mun
- Rainwater Research Center, Seoul National University, 599 Gwanangno, Gwanak-gu, Seoul 151-742, Republic of Korea.
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15
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Dillon AC, Robinson MB, Han MY, George SM. Decomposition of Alkylsilanes on Silicon Surfaces Using Transmission Ftir Spectroscopy. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-222-213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTFourier transform infrared (FTIR) transmission spectroscopy was used to monitor the decomposition of alkylsilanes such as diethylsilane (DES) [(CH3 CH2)2SiH2], di-t-butylsilane (DTBS) [((CH3)3C)2SiH2] and ethylsilane (ES) [CH3CH2SiH3 on high-surface-area porous silicon samples. The FTIR spectra revealed that tKe akylsilanes dissociatively adsorb on porous silicon at 300 K to form SiH and Si-alkyl species. As the silicon surface was progressively annealed, the Si-alkyl species decomposed and produced gas phase ethylene (DES,ES) or isobutylene (DTBS). The decomposition of the alkyl group was accompanied by the growth of additional SiH surface species. These reaction products were consistent with a [β-hydride elimination reaction. Above 700 K, the SiH surface species decreased concurrently with the desorption of H2 from the porous silicon surface. The uptake of surface species was also monitored at various adsorption temperatures to determine the optimal exposure temperatures for carbon-free silicon deposition. Carbon contamination was not detected at adsorption temperatures below 640 K prior to H2 desorption. Because the alkylsilane adsorption process is self-limiting at temperatures below 640 K, alkylsilanes may be useful molecular precursors for the atomic layer epitaxy (ALE) of silicon.
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16
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Han MY, Mun JS. Operational data of the Star City rainwater harvesting system and its role as a climate change adaptation and a social influence. Water Sci Technol 2011; 63:2796-2801. [PMID: 22049701 DOI: 10.2166/wst.2011.597] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The Star City rainwater harvesting system (RWHS) was featured in the December, 2008, issue of Water 21. The article highlighted that the RWHS has a 3,000 m3 rainwater tank used in water saving, flood mitigation, and emergency response. Since then, many news media, public officials, and people from both South Korea and abroad have visited the RWHS. In this paper, two years of the system's operational data are presented and its role in short- and long-term climate change adaptation is investigated. The downstream sewer system has become safe for a 50-year rainfall without upgrading the existing sewer system, which was designed for a 10-year period. The 26,000 m3 of water saved has reduced the energy requirement of transferring water from a distant area. The success of the Star City RWHS has influenced 47 cities across South Korea, including Seoul, to enact regulations on rainwater management. It has shown that decentralized rainwater management can supplement the existing centralized system to ensure its safety.
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Affiliation(s)
- M Y Han
- Department of Civil and Environmental Engineering, Seoul National University, 599 Gwanangno, Gwanak-gu, Seoul 151-742, Republic of Korea
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17
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Lee JY, Kim HJ, Han MY. Quality assessment of rooftop runoff and harvested rainwater from a building catchment. Water Sci Technol 2011; 63:2725-2731. [PMID: 22049771 DOI: 10.2166/wst.2011.592] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A major obstacle to the promotion of rainwater harvesting is chemical and microbiological concerns. To determine its suitability as an alternative water resource, water quality parameters such as pH, turbidity and metal ion concentrations and counted total coliform, Escherichia coli and heterotrophic bacteria were measured. It was observed that the stored rainwater had a neutral average pH and that its turbidity depended on the duration and intensity of the rainfall event. Metal concentrations were within the permissible limits specified in the Korea drinking water standard. In addition, counts of coliform, E. coli and heterotrophic bacteria were higher in the first flush 5 min after the start of the rainfall event. Principal component analysis and correlation analysis through 40 events in 2009 showed that the quality of stored rainwater depends on the conditions of the catchment and storage tank and the antecedent dry period.
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Affiliation(s)
- J Y Lee
- Natural Products Center, KIST (Korea Institute of Science and Technology), Gangneung Institute, Gangnueng 210-340, South Korea
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18
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Abstract
In order to evaluate the potential of rainwater harvesting (RWH) for mitigating water scarcity in a semi-arid zone of the country (Mashhad-Iran), three typical RWH systems were installed and monitored. The first system consists of 5,000 m² natural ground catchment which was leveled and covered with plastic sheets allowing for maximum possible runoff generation. Surface runoff was conducted into a 500 m³ ground reservoir via a series of draining ditches and an end collection channel. The water collected from a plastic covered catchment was used for irrigation of dryland wheat cultivation. According to the result of two years measurements, grain yield was almost doubled in irrigated plots when compared to conventional rainfed cultivation. In the second RWH system, runoff generated from about 2 ha asphaltic road and parking was diverted into a 1,200 m³ ground reservoir. The results of 2 years measurement for reservoir inflow and outflow indicated that runoff generated during rainy season was sufficient to produce necessary water for irrigating 900 planted fruit trees during successive dry seasons. The last experiment reported here is about a 40 m² roof area which was connected to a plastic tank for runoff measurement. The conclusion was that the proposed RWH system can produce enough water for building's toilets' flashes and other sanitary purposes so that the potable water could be saved considerably. In general, the results of three rainwater harvesting experiments showed the importance of using rainwater for compensating the effect of water shortages which is repeatedly occurring due to the effect of current climate change and ever increasing water utilization for drinking and food production.
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Affiliation(s)
- J Tabatabaee
- Khorasan Agriculture and Natural Resource Research Center, Iran.
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19
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Abstract
Recent research and monitoring undertaken by various institutions have emphasized measurements of river-water quality. Based on the results, government agencies have set guidelines to improve river-water quality management. However, the relationship between water quality and land use/land cover (LULC) has not been examined closely in South Korea to date. This study investigated this relationship in the Imgok River watershed. For this study, the relationship between water quality parameters, e.g. metallic ions, biological oxygen demand and chemical oxygen demand (BOD and COD), NH₃, NO₃ and PO₄ levels and land-use types (abandoned mine land, forest/grassland, agricultural, livestock and residential areas) was examined by correlation analysis with significant level (p<0.05) and principal component analysis (PCA). Applying PCA to water quality parameters according to land-use coverage, the principal component impacting river water quality were found to be the pH, metallic ions, BOD, PO₄, COD and total suspended solids (TSS) for abandoned mine land (AML) coverage; BOD, NO₃ and PO₄ for forest/grassland areas; TSS, NO₃, and PO₄ for agricultural land; BOD, COD, NH₃ and NO₃ for livestock coverage; and BOD, COD, NH₃ and PO₄ for residential areas. For the AML, the pH exhibited a significant negative correlation with other water quality parameters at the significant level (p<0.05). Grassland showed significant positive correlations of BOD with values of 0.837 NO₃ and 0.514 PO₄. In agricultural land, TSS had a significant negative correlation with value of -0.772 PO₄. For livestock coverage, BOD had significant positive correlations with values of 0.865 COD, 0.629 NH₃, 0.709 NO₃ and 0.472 TSS. In residential areas, COD was significantly positively correlated with values of 0.988 BOD and 0.856 PO₄, and TSS was highly positively correlated with value of 0.810 NO₃ but highly negatively correlated with value of -0.702 PO₄. Based on the above, LULC is a significant factor to influence on river water quality and this relationship should be based on the management plan for river water quality control. Future work will be conducted to take more samples in the entire river and season, to run water quality model and to choose a new method for better analysis and more accurate relationship between land-use and water quality.
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Affiliation(s)
- J Y Lee
- Natural Products Center, KIST (Korea Institute of Science and Technology)-Gangneung Institute, Gangnueng 210-340, South Korea.
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20
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Amin MT, Han MY. Roof-harvested rainwater for potable purposes: application of solar collector disinfection (SOCO-DIS). Water Res 2009; 43:5225-5235. [PMID: 19783275 DOI: 10.1016/j.watres.2009.08.041] [Citation(s) in RCA: 6] [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] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 08/20/2009] [Accepted: 08/24/2009] [Indexed: 05/28/2023]
Abstract
The efficiency of solar disinfection (SODIS), recommended by the World Health Organization, has been determined for rainwater disinfection, and potential benefits and limitations discussed. The limitations of SODIS have now been overcome by the use of solar collector disinfection (SOCO-DIS), for potential use of rainwater as a small-scale potable water supply, especially in developing countries. Rainwater samples collected from the underground storage tanks of a rooftop rainwater harvesting (RWH) system were exposed to different conditions of sunlight radiation in 2-L polyethylene terephthalate bottles in a solar collector with rectangular base and reflective open wings. Total and fecal coliforms were used, together with Escherichia coli and heterotrophic plate counts, as basic microbial and indicator organisms of water quality for disinfection efficiency evaluation. In the SOCO-DIS system, disinfection improved by 20-30% compared with the SODIS system, and rainwater was fully disinfected even under moderate weather conditions, due to the effects of concentrated sunlight radiation and the synergistic effects of thermal and optical inactivation. The SOCO-DIS system was optimized based on the collector configuration and the reflective base: an inclined position led to an increased disinfection efficiency of 10-15%. Microbial inactivation increased by 10-20% simply by reducing the initial pH value of the rainwater to 5. High turbidities also affected the SOCO-DIS system; the disinfection efficiency decreased by 10-15%, which indicated that rainwater needed to be filtered before treatment. The problem of microbial regrowth was significantly reduced in the SOCO-DIS system compared with the SODIS system because of residual sunlight effects. Only total coliform regrowth was detected at higher turbidities. The SOCO-DIS system was ineffective only under poor weather conditions, when longer exposure times or other practical means of reducing the pH were required for the treatment of stored rainwater for potable purposes.
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Affiliation(s)
- M T Amin
- Department of Environmental Sciences, COMSATS Institute of Information Technology, Abbottabad, 22060, Pakistan.
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21
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Jiang Z, Henriksen EA, Tung LC, Wang YJ, Schwartz ME, Han MY, Kim P, Stormer HL. Infrared spectroscopy of Landau levels of graphene. Phys Rev Lett 2007; 98:197403. [PMID: 17677660 DOI: 10.1103/physrevlett.98.197403] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Indexed: 05/16/2023]
Abstract
We report infrared studies of the Landau level (LL) transitions in single layer graphene. Our specimens are density tunable and show in situ half-integer quantum Hall plateaus. Infrared transmission is measured in magnetic fields up to B=18 T at selected LL fillings. Resonances between hole LLs and electron LLs, as well as resonances between hole and electron LLs, are resolved. Their transition energies are proportional to sqrt[B], and the deduced band velocity is (-)c approximately equal to 1.1 x 10(6) m/s. The lack of precise scaling between different LL transitions indicates considerable contributions of many-particle effects to the infrared transition energies.
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Affiliation(s)
- Z Jiang
- Department of Physics, Columbia University, New York, NY 10027, USA.
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22
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Abstract
Design of a rainwater storage tank is mostly based on the mass balance of rainwater with respect to the tank, considering aspects such as rainfall runoff, water usage and overflow. So far, however, little information is available on the quality aspects of the stored rainwater, such as the behavior of particles, the effect of retention time of the water in the tank and possible influences of system configuration on water quality in the storage tank. In this study, we showed that the performance of rainwater storage tanks could be maximized by recognizing the importance of water quality improvement by sedimentation and the importance of the system configuration within the tank, as well as the efficient collection of runoff. The efficiency of removal of the particles was increased by there being a considerable distance between the inlet and the outlet in the rainwater storage tank. Furthermore, it is recommended that the effective water depth in a rainwater tank be designed to be more than 3 m and that the rainwater be drawn from as close to the water surface as possible by using a floating suction device. An operation method that increases the retention time by stopping rainwater supply when the turbidity of rainwater runoff is high will ensure low turbidity in the rainwater collected from the tank.
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Affiliation(s)
- M Y Han
- School of Civil, Urban & Geosystems Engineering, Seoul National University, San 56-1, Shilim-dong, Gwanak-gu, Seoul, 151-742, Republic of Korea.
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Dockko S, Park SC, Kwon SB, Han MY. Application of the flotation process to thicken the sludge from a DAF plant. Water Sci Technol 2006; 53:159-65. [PMID: 16752777 DOI: 10.2166/wst.2006.220] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Dissolved air flotation (DAF) was evaluated for thickening of the sludges from a water treatment plant which uses DAF. Solid flux theory for gravity thickening was applied to the solid flux of DAF sludge. The higher the polymer dosage, at fixed solid concentration, the greater the rising velocity becomes. When applied with solid flux equations, a similar relationship to that of gravity thickening has been found. However, the values were much higher than in gravity thickening, because both the inflow solid concentration and the floating velocity were higher than for settled sludge. With this result, the proper dosage of polymer could be derived from the relationship between total solid flux and withdrawal velocity of DAF sludge.
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Affiliation(s)
- S Dockko
- Dankook University, Dept of Civil and Environmental Eng, Chungnam, Korea.
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24
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Han MY, Kim MK, Ahn HJ. Effects of surface charge, micro-bubble size and particle size on removal efficiency of electro-flotation. Water Sci Technol 2006; 53:127-32. [PMID: 16752773 DOI: 10.2166/wst.2006.216] [Citation(s) in RCA: 10] [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] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Flotation is a water treatment alternative to sedimentation, and uses small bubbles to remove low-density particles from potable water and wastewater. The effect of zeta potential, bubble size and particle size on removal efficiency of the electro-flotation process was investigated because previous model-simulations indicated that these attributes are critical for high collision efficiency between micro-bubbles and particles. Solutions containing Al3+ as the metal ion were subjected to various conditions. The zeta potentials of bubbles and particles were similar under identical conditions, and their charges were influenced by metal ion concentration and pH. Maximum removal efficiency was 98 and 12% in the presence and absence of flocculation, respectively. Removal efficiency was higher when particle size was similar to bubble size. These results agree with modelling simulations and indicate that collision efficiency is greater when the zeta potential of one is negative and that of the other is positive and when their sizes are similar.
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Affiliation(s)
- M Y Han
- The School of Civil, Urban and Geosystems Engineering, Seoul National University, Korea.
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25
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Dockko S, Han MY. Fundamental characteristics of bubbles and ramifications for the flotation process. Water Sci Technol 2004; 50:207-214. [PMID: 15686023] [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] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Flotation processes involve the use of very small bubbles (micro-bubbles) to separate particles from water. The process has become a good alternative to sedimentation, especially where the particles are small or of low density. Although the flotation process commences with a collision between particles and bubbles, most research has been focused only on the characteristics of the particles. In this paper, recent theoretical and experimental research on the characteristics of bubbles is summarized. The effect on the collision efficiency of the size and charge of bubbles is calculated through trajectory analysis. The size and charge of bubbles are measured under different conditions and the ramifications of the results are discussed. The results may lead to a better understanding and optimization of the existing process. In particular, we discuss an idea that a new advanced flotation process might be possible by the modification of the characteristics of the bubble alone or of both bubble and particle.
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Affiliation(s)
- S Dockko
- Dankook University, Chunan city, Chungnam, Korea.
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26
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Han MY, Ahn HJ, Shin MS, Kim SR. The effect of divalent metal ions on the zeta potential of bubbles. Water Sci Technol 2004; 50:49-56. [PMID: 15566186] [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] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Micro-bubbles are used in electro-flotation (EF) and dissolved air flotation (DAF) for particle separation. The efficiency of these flotation processes depends on the collision of bubble and particle and the collision efficiency is affected by certain parameters with respect to the size and zeta potential of bubble and particle. Therefore, it is necessary to monitor not only the zeta potential of the particle, but also that of the bubble. Gas bubbles are reported to be generally negatively charged in water. In this paper, we report a study performed to measure the zeta potential of bubbles in solutions containing divalent metals and find factors which can produce positively charged bubbles. Calcium and magnesium ions were selected as divalent metal ions because natural water normally contains an appreciable quantity of them. It was found that bubbles are negatively charged in CaCl2 solutions whereas, under certain conditions, they become positively charged in MgCl2. Charge reversal of bubbles was observed above 10(-2) M Mg, especially above pH 9. A probable principle that explained the charge reversal could be a combined mechanism with both specific adsorption of hydroxylated species and formation of hydroxide precipitates. Creating solution conditions that can produce positively charged bubbles in flotation methods might make it possible to remove particles using lesser amounts of coagulant or even none at all.
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Affiliation(s)
- M Y Han
- Department of Civil Urban and Geosystem Engineering, Seoul National University, San 56-1, Shillim-dong, Gwanak-gu, Seoul, 151-742, Republic of Korea.
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Yoon SY, Jeong MJ, Yoo J, Lee KI, Kwon BM, Lim DS, Lee CE, Park YM, Han MY. Grb2 dominantly associates with dynamin II in human hepatocellular carcinoma HepG2 cells. J Cell Biochem 2002; 84:150-5. [PMID: 11746524 DOI: 10.1002/jcb.1275] [Citation(s) in RCA: 13] [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] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The two SH3 domains and one SH2 domain containing adaptor protein Grb2 is an essential element of the Ras signaling pathway in multiple systems. The SH2 domain of Grb2 recognizes and interacts with phosphotyrosine residues on activated tyrosine kinases, whereas the SH3 domains bind to several proline-rich domain-containing proteins such as Sos1. To define the difference in Grb2-associated proteins in hepatocarcinoma cells, we performed coprecipitation analysis using recombinant GST-Grb2 fusion proteins and found that several protein components (p170, p125, p100, and p80) differently associated with GST-Grb2 proteins in human Chang liver and hepatocarcinoma HepG2 cells. Sos1 and p80 proteins dominantly bind to Grb2 fusion proteins in Chang liver, whereas p100 remarkably associate with Grb2 in HepG2 cells. Also GST-Grb2 SH2 proteins exclusively bound to the p46(Shc), p52(Shc), and p66(Shc) are important adaptors of the Ras pathway in HepG2 cells. The p100 protein has been identified as dynamin II. We observed that the N-SH3 and C-SH3 domains of Grb2 fusion proteins coprecipitated with dynamin II besides Sos1. These results suggest that dynamin II may be a functional molecule involved in Grb2-mediated signaling pathway on Ras activation for tumor progression and differentiation of hepatocarcinoma cells.
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Affiliation(s)
- S Y Yoon
- Cell Biology Laboratory, Korea Research Institute of Bioscience and Biotechnology, P.O. Box 115, Yusung, Taejon 305-600, Korea
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28
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Han MY, Shim JS, Chung YK, Park YH. Diagnosing and optimizing water treatment processes by using particle counter: a case study in Korea. Water Sci Technol 2002; 45:511-518. [PMID: 11936674] [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] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The goal of the flocculation process is to change the particle size distribution to best suit the subsequent processes. Although several methods exist to evaluate the flocculation process, no single universally accepted method has yet to be developed. The purpose of this paper is to present experiences whereby particle counting was used in the diagnosis and optimization of the flocculation process. A commercially available on-line continuous particle counter has been used in evaluating the design and the operation of this process at two conventional Water Treatment Plants. The evaluation is based on particle dynamics, i.e., the change of the number of small and large particles. Some design deficiencies in the distribution channel and flocculation process have been identified from this method, and thus some operational parameters are suggested for optimum performance. Because the optimum condition may be site-specific, the method presented in this paper will be beneficial in the evaluation of the flocculation process at other water treatment plants.
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Affiliation(s)
- M Y Han
- School of Civil, Urban & Geosystem Engineering, Seoul National University, Korea
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29
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Won M, Jang YJ, Chung KS, Kim DU, Hoe KL, Han MY, Kim HB, Lee SH, Oh HW, Yoo HS. Pleckstrin homology domain interacts with Rkp1/Cpc2, a RACK1 homolog, to modulate Pck2-mediated signaling process in Schizosaccharomyces pombe. Biochem Biophys Res Commun 2001; 289:987-92. [PMID: 11741288 DOI: 10.1006/bbrc.2001.6094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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: 11/22/2022]
Abstract
Rkp1/Cpc2, a fission yeast RACK1 homolog, interacts with Pck2, a PKC homolog, and is involved in the regulation of pck2-mediated signaling process. The N-terminal region of split pleckstrin homology domain (nPH) in human PLC-gamma1 bound to Rkp1/Cpc2 concomitantly with Pck2. nPH inhibited kinase activity of GST-Pck2 purified from Schizosaccharomyces pombe in vitro. The lethality induced by pck2(+) overexpression was suppressed by coexpression of either rkp1(+) or nPH domain. This result suggests that Rkp1/Cpc2 interacts with PH domain-containing protein and regulates the Pck2-mediated signaling process in S. pombe.
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Affiliation(s)
- M Won
- Genome Research Center, Korea Research Institute of Biotechnology and Bioscience, Taejon, 305-600, Korea.
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30
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Abstract
An hypoxic microenvironment is an important modulator of gene expression in many pathophysiological conditions. In this study, we show a coordinate activation of heat shock transcription factor (HSF) and hypoxia-inducible factor-1 (HIF-1) in RIF tumor cells by hypoxia. Since heat shock protein (hsp) and angiogenic factor genes that are regulated by HSF and HIF-1 are thought to contribute to the malignant progression of hypoxic tumor cells, it was of our major interest to identify the components that are responsible for the activation of both HSF and HIF-1. Our finding that a bioflavonoid quercetin (QCT), a well known inhibitor of hsp gene expression, significantly inhibited the transcriptional activation of HSF and HIF-1 strongly suggests that QCT-sensitive molecule(s) is involved in the transcriptional activation of HSF and HIF-1 by hypoxia. Our results revealed that PCKalpha, delta and epsilon isoforms are expressed in RIF cells, but only PKCdelta was specifically translocated to the membrane by hypoxia. Our results also revealed that the translocation of PKCdelta was completely abrogated by QCT. Moreover, inhibiting the PKCdelta activation, either pharmacologically with phorbol 12-myristate 13-acetate or with bisindolymaleimide II or genetically by transient transfection of a dominant negative PKCdelta, significantly inhibited the transcriptional activation of HSF and HIF-1 by hypoxia. These results strongly substantiate a view that the PKCdelta isozyme is the QCT-sensitive molecule that plays an important role in transmitting hypoxia signals to both HSF and HIF-1. Here we show that the membrane translocation of PKCdelta is dependent on the activation of phosphoinositol 3-kinase (PI3K). Treatment with PI3K inhibitor, wortmannin or LY294002, abrogated not only PKCdelta translocation but the subsequent transcriptional activation of HSF and HIF-1 by hypoxia. Together, our study shows that the PKCdelta isozyme acts as a shared component in transmitting hypoxia-induced signals to both HSF and HIF-1, and that the upstream regulator of PKCdelta is PI3K.
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Affiliation(s)
- S H Baek
- Department of Biology, University of Incheon, Korea
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Yoo J, Jeong MJ, Lee SS, Lee KI, Kwon BM, Park YM, Han MY. Negative regulation of YY1 transcription factor on the dynamin I gene promoter. Biochem Biophys Res Commun 2001; 283:340-3. [PMID: 11327704 DOI: 10.1006/bbrc.2001.4784] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [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: 11/22/2022]
Abstract
Dynamin I is highly expressed in brain and plays a critical role in clathrin-mediated endocytosis and synaptic vesicle recycling. To elucidate the molecular mechanism by which expression of dynamin I is tissue-specifically regulated, we previously cloned and characterized the promoter of the mouse dynamin I gene and suggested that there is a negative regulatory element in this promoter region. In the present study, we showed that YY1 binds to this negative regulatory element located at -111 to -107 by using the EMSA and supershift analyses. Cotransfection experiment using an YY1 expression vector revealed that YY1 exerts a repressive role on the dynamin I gene promoter activity. These results demonstrate that transcription factor YY1 negatively regulates dynamin I expression via binding to the negative regulatory element.
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Affiliation(s)
- J Yoo
- Cell Biology Laboratory, Korea Research Institute of Bioscience and Biotechnology, Taejon, Yusung, 305-600, Korea
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Yoo J, Jeong MJ, Lee SS, Lee KI, Kwon BM, Kim DS, Park YM, Han MY. The Neuron Restrictive Silencer Factor Can Act as an Activator for Dynamin I Gene Promoter Activity in Neuronal Cells. Biochem Biophys Res Commun 2001; 283:928-32. [PMID: 11350074 DOI: 10.1006/bbrc.2001.4857] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The neuron restrictive silencer element (NRSE) has been identified in several neuronal genes and confers neuron specificity by silencing transcription in nonneuronal cells. We have previously reported that Sp1 and an NF-kappaB-like element (NE-1) are required for the promoter activity of mouse dynamin I gene. In the present study, we found that the upstream regulatory region of the dynamin I promoter has an NRSE-like sequence and showed that neuron restrictive silencer factor (NRSF) binds to this element in neuronal cells as well as in nonneuronal cells. We also showed that NRSF activates the promoter activity of dynamin I gene in neuronal cells. From the results in this study, we suggest that NRSE might be involved in the neuron restriction of dynamin I expression, and NRSF could act as an activator for promoter activity of dynamin I gene in neuronal cells.
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Affiliation(s)
- J Yoo
- Cell Biology Laboratory, Korea Research Institute of Bioscience and Biotechnology, Yusung, Taejon, 305-600, Korea
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Jeong MJ, Yoo J, Lee SS, Lee KI, Cho A, Kwon BM, Moon MJ, Park YM, Han MY. Increased GTP-binding to dynamin II does not stimulate receptor-mediated endocytosis. Biochem Biophys Res Commun 2001; 283:136-42. [PMID: 11322780 DOI: 10.1006/bbrc.2001.4681] [Citation(s) in RCA: 4] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Regarding the molecular mechanism of dynamin in receptor-mediated endocytosis, GTPase activity of dynamin has been thought to have a critical role in endocytic vesicle internalization. However, a recent report suggested that GTP-binding to dynamin itself activates the dynamin to recruit molecular machinery necessary for endocytosis. In this study, to investigate the role of GTP binding to dynamin II, we generated two mutant dynamin II constructs: G38V and K44E. G38V, its GTP binding site might be mainly occupied by GTP caused by reduced GTPase activity, and K44E mutant, its GTP binding site might be vacant, caused by its decreased affinity for GTP and GDP. From the analysis of the ratio of GTP vs GDP bound to dynamin, we confirmed these properties. To test the effect of these mutant dynamins on endocytosis, we performed flow cytometry and confocal immunofluorescence analysis and found that these two mutants have inhibitory effect on transferrin-induced endocytosis. Whereas fluorescent transferrin was completely internalized in wild-type (WT) dynamin II expressing cells, no intracellular accumulation of fluorescent transferrin was found in the cells overexpressing K44E and G38V mutant. Interestingly, the amount of GTP bound to K44E was increased when endocytosis was induced than that bound to WT. The present results suggested that the GTPase activity of dynamin II is required for formation of endocytic vesicle and GTP-binding to dynamin II per se is not sufficient for stimulating endocytosis.
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Affiliation(s)
- M J Jeong
- Cell Biology Laboratory, Korea Research Institute of Bioscience and Biotechnology, Taejon, Yusung, 305-600, Korea
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Shin SY, Kim SY, Kim JH, Min DS, Ko J, Kang UG, Kim YS, Kwon TK, Han MY, Kim YH, Lee YH. Induction of early growth response-1 gene expression by calmodulin antagonist trifluoperazine through the activation of Elk-1 in human fibrosarcoma HT1080 cells. J Biol Chem 2001; 276:7797-805. [PMID: 11121417 DOI: 10.1074/jbc.m009465200] [Citation(s) in RCA: 30] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The early growth response gene-1 (Egr-1) is a transcription factor that plays an important role in cell growth and differentiation. It has been known that Egr-1 expression is down-regulated in many types of tumor tissues, including human fibrosarcoma HT1080 cells, and introduction of the Egr-1 gene into HT1080 cells inhibits cell growth and tumorigenic potential. Trifluoperazine (TFP), a phenothiazine class calmodulin antagonist, is known to inhibit DNA synthesis and cell proliferation and potentially important in antitumor activities. To understand the regulatory mechanism of Egr-1, we investigated the effect of TFP on expression of Egr-1 in HT1080 cells. Herein, we report that Egr-1 expression was increased by TFP in synergy with serum at the transcriptional level. Both the Ca(2+)/calmodulin-dependent protein kinase II inhibitor KN62 and the calcineurin inhibitor cyclosporin A enhanced TFP-dependent increase of Egr-1, suggesting that the Ca(2+)/calmodulindependent pathway plays a role in regulation of Egr-1 expression in HT1080 cells. The TFP-stimulated increase of the Egr-1 protein was preferentially inhibited by the MEK-specific inhibitor PD98059. In addition, activation of human Egr-1 promoter and the transcriptional activation of the ternary complex factor Elk-1 induced by TFP were inhibited both by pretreatment of PD98059 and by expression of the dominant-negative RasN17. These results indicate that the Ras/MEK/Erk/Elk-1 pathway is necessary for TFP-induced Egr-1 expression. We propose that the calmodulin antagonist TFP stimulates Egr-1 gene expression by modulating Ras/MEK/Erk and activation of the Elk-1 pathway in human fibrosarcoma HT1080 cells.
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Affiliation(s)
- S Y Shin
- Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu 705-717, South Korea
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Min JN, Han MY, Lee SS, Kim KJ, Park YM. Regulation of rat heat shock factor 2 expression during the early organogenic phase of embryogenesis. Biochim Biophys Acta 2000; 1494:256-62. [PMID: 11121583 DOI: 10.1016/s0167-4781(00)00053-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A central step in the transcriptional regulation of heat shock protein (hsp) genes is the binding of the heat shock factor (HSF) to the upstream heat shock elements (HSEs). In vertebrates, HSF2 has been suggested to mediate the transcriptional regulation of hsp gene expression during development and differentiation. The expression levels of HSF2 were shown to vary widely among fully developed mouse organs. However, there exists limited information on the regulation of HSF2 expression during the inductive stage of organ formation in mammalian development. In this study, we have cloned the rat HSF2 cDNA and examined embryos for HSF2 expression from days 9.5 (E9.5) to 15.5 (E15.5) of gestation that correspond to the period when the major organ primordia are being actively established. We show that rat HSF2 has 94.6 and 96.3% identity to mouse HSF2 in nucleotide and amino acid sequences, respectively. By establishing a competitive RT-PCR, we show that about 503.6 pg of HSF2 mRNA were present per microgram of embryonic RNA in the primitive streak stage E9.5 embryos. The amounts of HSF2 mRNA then gradually decreased, resulting in an approximately 300-fold reduction in E15.5 embryos. The amounts of HSF2 mRNA in the embryos were found to be closely correlated with those of HSF2 protein and their HSE-binding activities. To our knowledge, this is the first detailed report on the structure and regulation of the rat HSF2 during the early organogenic period of mammalian embryogenesis.
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Affiliation(s)
- J N Min
- Department of Biology, University of Inchon, Dohwa-Dong, South Korea
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Park EM, Choi JH, Park JS, Han MY, Park YM. Measurement of glutathione oxidation and 8-hydroxy-2'-deoxyguanosine accumulation in the gerbil hippocampus following global ischemia. Brain Res Brain Res Protoc 2000; 6:25-32. [PMID: 11086260 DOI: 10.1016/s1385-299x(00)00033-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Involvement of oxidative stress in ischemia/reperfusion-induced brain damage has been suggested. However, experimental support of this suggestion was limited partly because sensitive indices to assess oxidative consequences of ischemic brain damage were few. We have established biochemical assay systems to assess oxidative brain damage following ischemia. Mongolian gerbil brains were subjected to global ischemia/reperfusion, and the hippocampi were analyzed for oxidative damage by measuring temporal changes in glutathione and 8-ohdG following ischemia. Under oxidative stress, glutathione is known to be oxidized and subsequently depleted from cells. Therefore, glutathione content and its redox status can serve as sensitive indicators of oxidative damage. The accumulation of 8-ohdG has also been recognized as an excellent marker for oxidative DNA damage. The reduced and oxidized glutathione were measured by HPLC method following derivatization with 2,4-dinitrofluorobenzene. The 8-ohdG in DNA hydrolyzate was measured by HPLC with electrochemical detection. While total glutathione content decreased, glutathione oxidation ratio and 8-ohdG accumulation increased over a period of 30 min of reperfusion following ischemia. The results demonstrated that glutathione content, its oxidation ratio, and the accumulated 8-ohdG could be utilized as sensitive indices for the assessment of oxidative brain damage.
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Affiliation(s)
- E M Park
- Department of Chemistry, University of Inchon, 402-749, Inchon, South Korea
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Yoo J, Lee SS, Jeong MJ, Lee KI, Kwon BM, Kim SH, Park YM, Han MY. Characterization of the mouse dynamin I gene promoter and identification of sequences that direct expression in neuronal cells. Biochem J 2000; 351 Pt 3:661-8. [PMID: 11042120 PMCID: PMC1221405] [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: 02/18/2023]
Abstract
Dynamin I is expressed at high levels in brain and its expression is regulated during the developmental stages of brain. To elucidate the molecular mechanism by which the expression is tissue-specifically regulated, we cloned the 5'-flanking region of the mouse dynamin I gene and determined the nucleotide sequence of 1036 bases upstream from the translation start site. Transient transfection studies with a chloramphenicol acetyltransferase reporter gene in neuroblastoma NS20Y and Lewis lung cells demonstrated that the 5'-flanking region has a cell-type-specific promoter activity. Deletion analyses demonstrated that the minimal promoter activity was detected in the proximal region 195 bp upstream of the translation initiation codon (-90 to +105). The minimal promoter was embedded in a GC-rich region (75% GC content), in which an Sp1-binding motif and a nuclear factor (NF)-kappa B-like element (NE-1) were found, but it lacked TATA and CAAT boxes. Mutational analysis and electrophoretic mobility-shift assay analysis revealed that Sp1 binds to the Sp1 site and that this element is critical for the promoter activity of the dynamin I gene. We found that the NE-1 sequence is required for the expression of the dynamin I gene but NEBP (NE-1-binding protein), which binds to the NE-1 sequence, is not NF-kappa B. We also found that one base in the NE-1 sequence (the underlined G residue in GGGATTCGCGGA) is critical for binding specificity to discriminate between NEBP and NF-kappa B. By UV cross-linking analysis, we found that NEBP is an approx. 104 kDa nuclear protein.
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Affiliation(s)
- J Yoo
- Cell Biology Laboratory, Korea Research Institute of Bioscience and Biotechnology, P.O. Box 115, Yusung, Taejon 305-600, Korea
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Nam JY, Kim HK, Kwon JY, Han MY, Son KH, Lee UC, Choi JD, Kwon BM. 8-O-Methylsclerotiorinamine, antagonist of the Grb2-SH2 domain, isolated from Penicillium multicolor. J Nat Prod 2000; 63:1303-1305. [PMID: 11000046 DOI: 10.1021/np0001169] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new secondary metabolite, 8-O-methylsclerotiorinamine (1), was isolated from a strain of Penicillium multicolor, and its structure was established using NMR spectroscopy and chemical evidence. The metabolite inhibited significantly the binding between the Grb2-SH2 domain and the phosphopeptide derived from the Shc protein and also blocked the protein-protein interactions of Grb2-Shc in cell-based experiments, with IC(50) values of 5.3 and 50 microM, respectively.
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Affiliation(s)
- J Y Nam
- Korea Research Institute of Bioscience & Biotechnology, 52 Uen-dong, Yusung, Taejon, 305-333, Republic of Korea
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Abstract
A series of cinnamaldehydes was synthesized for the study of inhibitory activity against cyclin dependent kinases (CDKs). A couple of compounds selectively inhibited cyclin D1-CDK4 with an IC50 value of 7-18 microM.
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Affiliation(s)
- H W Jeong
- Korea Research Institute of Bioscience and Biotechnology, KIST, Taejon, South Korea
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Kim HK, Nam JY, Han MY, Son KH, Choi JD, Kwon BM, Takusagawa HL, Huang Y, Takusagawa F. Natural and synthetic analogues of actinomycin D as Grb2-SH2 domain blockers. Bioorg Med Chem Lett 2000; 10:1455-7. [PMID: 10888331 DOI: 10.1016/s0960-894x(00)00258-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [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: 11/21/2022]
Abstract
Natural analogues (D, C2, and VII) of actinomycin inhibit Grb2 SH2 domain binding with phosphopeptide-derived from Shc in vitro and in intracellular system. To study structure-activity relationships, 13 actinomycin analogues were synthesized and we found that the inhibition activity depended on the substituents of cyclic peptide groups in actinomycin and two analogues with Tyr residue are the most potent inhibitors with IC50 value of 0.5 and 0.8 microM, respectively.
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Affiliation(s)
- H K Kim
- Korea Research Institute of Bioscience and Biotechnology, Yusung, Taejon, South Korea
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Abstract
Expression of heat shock proteins (HSPs) has been shown to protect mammalian cells exposed to a variety of stress stimuli. Among various HSPs, small HSPs from diverse species were shown to protect cells against oxidative stress. Here, we show that the overexpression of the mouse small hsp gene, hsp25, provides protection against ionizing radiation. Our results demonstrate that the radiation survival of the L929 cells stably transfected with hsp25 was enhanced compared with that of the parental or vector transfected control, L25#1 cells. Our results also demonstrate that the radiation-induced apoptosis was reduced in HSP25 overexpressors. A detailed analysis of glutathione composition of those clones that overexpressed HSP25 revealed the increases of the glutathione pool, which primarily resulted from the increase of reduced glutathione. Our data suggest that higher content of GSH in HSP25 overexpressors was because of a faster reduction of oxidized glutathione (GSSG) to GSH rather than an increased de novo synthesis of GSH. The activities of glutathione reductase (GRd) and glutathione peroxidase (GPx) were greater in HSP25 overexpressors but the activity of gamma-glutamylcysteine synthetase was similar between the transfectants and the control cells. Consistent with our view, a steady state ratio of the GSH/GSSG was greater in the transfectants in comparison with the control L25#1 cells. A difference in the relative ratio became more significant after exposure to the ionizing radiation. To our knowledge, this study provides the first experimental evidence in support of the hypothesis that small HSP plays a key role in radioresistance by modulating the metabolism of glutathione. Based on the results obtained from the current investigation, we propose that HSP25 helps facilitate the glutathione-redox cycle and therefore, enhances glutathione utilization and maintains the cellular glutathione pool in favor of the reduced states.
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Affiliation(s)
- S H Baek
- Department of Biology, University of Inchon, Inchon, Korea
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Baek SH, Kim JY, Choi JH, Park EM, Han MY, Kim CH, Ahn YS, Park YM. Reduced glutathione oxidation ratio and 8 ohdG accumulation by mild ischemic pretreatment. Brain Res 2000; 856:28-36. [PMID: 10677608 DOI: 10.1016/s0006-8993(99)02376-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A critical role of oxidative stress has been implicated in ischemic brain damage. Mild ischemic pretreatment and/or synthesis of heat shock proteins (HSPs) has been suggested to protect against oxidative brain damage. However, experimental support of this suggestion have proven to be difficult partly because sensitive indices to assess oxidative consequences of ischemic brain damage were few. In this study, we have attempted to establish biochemical assay systems to quantitate oxidative brain damage following ischemia. We produced experimental brain ischemia in the Mongolian gerbil (Meriones unguiculatus) and examined the hippocampus for ischemic brain damage. The results obtained from ischemic gerbil hippocampus demonstrated that oxidative brain damage can be quantitated by determining glutathione oxidation ratio together with the accumulation of the oxidative DNA damage product, 8-hydroxy-2'-deoxyguanosine (8 ohdG). Our results also demonstrated a role for mild ischemic pretreatment and synthesis of HSPs against oxidative brain damage. We showed that mild 2-min ischemic pretreatment reduced the degree of both glutathione oxidation ratio and 8 ohdG accumulation in gerbil hippocampus subsequent to 10 min ischemic challenge. We also showed that the accumulation of HSP70 was closely associated with the reduction of oxidative brain damage. To our knowledge, this is the first report to investigate glutathione redox states and oxidative DNA damage levels to evaluate a protective role of mild ischemic pretreatment and HSP synthesis following brain ischemia. Our data validate the previous suggestions and provide new additional data that argue for the protective role of mild ischemic pretreatment and HSP70 synthesis against oxidative brain damage.
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Affiliation(s)
- S H Baek
- Department of Biology, 177 Nam-Gu, Dowha-Dong, Univ. of Inchon, 402-749, Inchon, South Korea
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Carragee EJ, Han MY, Yang B, Kim DH, Kraemer H, Billys J. Activity restrictions after posterior lumbar discectomy. A prospective study of outcomes in 152 cases with no postoperative restrictions. Spine (Phila Pa 1976) 1999; 24:2346-51. [PMID: 10586459 DOI: 10.1097/00007632-199911150-00010] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.0] [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: 02/01/2023]
Abstract
STUDY DESIGN A prospective clinical trial was conducted. OBJECTIVES To determine the feasibility of removing activity restrictions after surgery and encouraging early return to work; to ascertain the clinical and behavioral response to such a strategy; and to identify factors predictive of early return to work, preparatory to possible randomized clinical trials. SUMMARY OF BACKGROUND INFORMATION Current practice usually entails several weeks to several months of restricted activities after lumbar discectomy to avoid disc "reinjury." Earlier work has suggested these restrictions may not be necessary. METHODS One hundred fifty-two consecutive working patients undergoing limited open discectomy for herniated lumbar intervertebral disc were treated postoperatively with no activity restrictions. Patients were encouraged to return to full activities as soon as possible. The patients were followed for a minimum of 2 years (average follow-up time = 4.8 years). At follow-up, an independent examiner evaluated each patient and collected further postoperative data. RESULTS One hundred forty-nine of the 152 patients (98%) returned to work. The average work loss was 1.2 weeks and 148 of 149 patients had returned to full duty by 8 weeks. Approximately one-third of the group returned to work within 1 week of surgery (32%), many the next day. Statistical analysis demonstrated very early return to work did not correlate with either recurrent sciatica, reoperation for reherniation, or ultimate clinical outcome. Seventeen patients (11.2%) had possible reherniations (recurrent sciatica) and eight underwent reoperation (5.3%). CONCLUSION Lifting of postoperative activity restrictions after limited discectomy allowed shortened time to return to work relative to the 4 to 16 weeks commonly recommended. Complication rates appear comparable to those reported in the literature for patients under postoperative restrictions. Postoperative restrictions may not be necessary in most patients.
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Affiliation(s)
- E J Carragee
- Spinal Surgery Section, Stanford University School of Medicine, California, USA.
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Kim HK, Nam JY, Han MY, Lee EK, Choi JD, Bok SH, Kwon BM. Actinomycin D as a novel SH2 domain ligand inhibits Shc/Grb2 interaction in B104-1-1 (neu*-transformed NIH3T3) and SAA (hEGFR-overexpressed NIH3T3) cells. FEBS Lett 1999; 453:174-8. [PMID: 10403397 DOI: 10.1016/s0014-5793(99)00710-3] [Citation(s) in RCA: 16] [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] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Actinomycins, a family of bicyclic chromopeptide lactones with strong antineoplastic activity, were screened as inhibitors of Shc/Grb2 interaction in in vitro assay systems. To investigate the effects of actinomycin D on Shc/Grb2 interaction in cell-based experiments, we used SAA (normal hEGFR-overexpressed NIH3T3) cells and B104-1-1 (neu*-transformed NIH3T3) cells, because a large number of the Shc/Grb2 complexes were detected. Associated protein complexes containing Shc were immunoprecipitated from actinomycin D-treated cell lysates with polyclonal anti-Shc antibody. Then the association with Grb2 was assessed by immunoblotting with monoclonal anti-Grb2 antibody. The result of the immunoblotting experiment revealed that actinomycin D inhibited Shc/Grb2 interaction in a dose-dependent manner in both B104-1-1 and EGF-stimulated SAA cells. The inhibition of Shc/Grb2 interaction by actinomycin D in B104-1-1 cells also reduced tyrosine phosphorylation of MAP kinase (Erk1/Erk2), one of the major components in the Ras-MAP kinase signaling pathway. These results suggest that actinomycin D could be a non-phosphorylated natural and cellular membrane-permeable SH2 domain antagonist.
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Affiliation(s)
- H K Kim
- Korea Research Institute of Bioscience and Biotechnology, KIST, Taejon, South Korea
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Koh WS, Yoon SY, Kwon BM, Jeong TC, Nam KS, Han MY. Cinnamaldehyde inhibits lymphocyte proliferation and modulates T-cell differentiation. Int J Immunopharmacol 1998; 20:643-60. [PMID: 9848396 DOI: 10.1016/s0192-0561(98)00064-2] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.2] [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
Two kinds of cinnamaldehyde derivative, 2'-hydroxycinnamaldehyde (HCA) and 2'-benzoxy-cinnamaldehyde (BCA), were studied for their immunomodulatory effects. These compounds were screened as anticancer drug candidates from stem bark of Cinnamomum cassia for their inhibitory effect on farnesyl protein transferase activity. Ras activation, which is accompanied with its farnesylation, has been known to be important in immune cell activation as well as in carcinogenesis. Treatment of these cinnamaldehydes to mouse splenocyte cultures induced suppression of lymphoproliferation following both Con A and LPS stimulation in a dose-dependent manner. A dose of I microM of HCA and BCA inhibited the Con A-stimulated proliferation by 69% and 60%, and the LPS-induced proliferation by 29% and 21%, respectively. However, the proliferation induced by PMA plus ionomycin was affected by neither HCA nor BCA treatment. Decreased levels of antibody production by HCA or BCA treatment were observed in both SRBC-immunized mice and LPS-stimulated splenocyte cultures. The exposure of thymocytes to HCA or BCA for 48 h accelerated T-cell differentiation from CD4 and CD8 double positive cells to CD4 or CD8 single positive cells. The inhibitory effect of cinnamaldehyde on lymphoproliferation was specific to the early phase of cell activation, showing the strongest inhibition of Con A- or LPS-stimulated proliferation when added concomitantly with the mitogens. In addition, the treatment of HCA and BCA to splenocyte cultures attenuated the Con A-triggered progression of cell cycle at G1 phase with no inhibition of S to G2/M phase transition. Although cinnamaldehyde treatment had no effect on the IL-2 production by splenocyte cultures stimulated with Con A, it inhibited markedly and dose-dependently the expression of IL-2Ralpha and interferon-gamma. Taken together, the results in this study suggest both HCA and BCA inhibit the lymphoproliferation and induce a T-cell differentiation through the blockade of early steps in signaling pathway leading to cell growth.
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Affiliation(s)
- W S Koh
- Immune Regulation Research Unit, Korea Research Institute of Bioscience and Biotechnology, Taejon
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46
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Abstract
OBJECTIVE To evaluate serial serum C-reactive protein (CRP) levels for diagnosis of neonatal infection. SETTING A regional intensive care nursery and two community intensive care nurseries. METHODS All neonates treated for suspected bacterial infection were prospectively evaluated using a standardized clinical pathway. Infants were categorized as having proven sepsis (bacteria isolated from blood, cerebrospinal fluid, or urine culture), probable sepsis (clinical and laboratory findings consistent with bacterial infection without a positive culture), or no sepsis (findings not consistent with sepsis), without consideration of CRP levels. Infants whose blood cultures yielded skin flora but who demonstrated no other signs of bacterial infection were not considered to have sepsis. CRP levels were determined at the initial evaluation and on each of the next two mornings. Sensitivity, specificity, predictive values, and likelihood ratios were calculated for the first (CRP #1), second (CRP #2), higher of the second and third (CRP #2 and #3), or highest of all three CRP levels (CRP x 3). RESULTS Sepsis was suspected within the first 3 days after birth in 1002 infants (early-onset) and on 184 occasions in 134 older infants (late-onset). There were 20 early-onset and 53 late-onset episodes of proven sepsis, and 74 early-onset and 12 late-onset episodes of probable sepsis. CRP #1 had sensitivities of 39.4% and 64.6% for proven or probable sepsis and 35.0% and 61.5% for proven sepsis in early-onset and late-onset episodes, respectively. CRP levels on the morning after the initial evaluation (CRP #2) had higher sensitivities (92. 9% and 85.0% for proven or probable sepsis and 78.9% and 84.4% for proven sepsis in early-onset and late-onset episodes, respectively), and normal results were associated with lower likelihoods of infection (likelihood ratios for normal results of 0.10 and 0.19 for proven or probable sepsis and 0.27 and 0.21 for proven sepsis, in early-onset and late-onset episodes, respectively). Three serial serum CRP levels had sensitivities of 97.8% and 98.1% for proven or probable sepsis and 88.9% and 97.5% for proven sepsis in early-onset and late-onset episodes, respectively. The negative predictive values for CRP x 3 were 99.7% and 98.7% for both proven or probable sepsis and for proven sepsis in early-onset and late-onset episodes, respectively. A CRP level obtained at the time of the initial evaluation can be omitted without significant loss of sensitivity or negative predictive value: the sensitivities of CRP #2 and #3 were 97.6% and 94.4% for proven or probable sepsis and 88.9% and 96.4% for proven sepsis in early-onset and late-onset episodes, respectively; negative predictive values were 99.7% both for proven and for proven or probable early-onset sepsis, 97.6% for proven or probable late-onset infection, and 98.8% for proven late-onset infection. Serial normal CRP levels were associated with a markedly reduced likelihood of infection as compared with that in the entire population before testing, with likelihood ratios ranging from 0.03 to 0.16 for the various subgroups. Maximum CRP levels >3 mg/dL had positive predictive values >20% for proven or probable early-onset infections and for proven or probable and proven late-onset infections, but only those >6 mg/dL had such a high positive predictive value for proven early-onset sepsis. CONCLUSIONS Serial CRP levels are useful in the diagnostic evaluation of neonates with suspected infection. Two CRP levels <1 mg/dL obtained 24 hours apart, 8 to 48 hours after presentation, indicate that bacterial infection is unlikely. The sensitivity of a normal CRP at the initial evaluation is not sufficient to justify withholding antibiotic therapy. The positive predictive value of elevated CRP levels is low, especially for culture-proven early-onset infections.
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Affiliation(s)
- W E Benitz
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, CA 94304, USA
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47
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Nam JY, Kim HK, Son KH, Kim SU, Kwon BM, Han MY, Chung YJ, Bok SH. Actinomycin D, C2 and VII, inhibitors of Grb2-SHC interaction produced by Streptomyces. Bioorg Med Chem Lett 1998; 8:2001-2. [PMID: 9873474 DOI: 10.1016/s0960-894x(98)00345-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 11/18/2022]
Abstract
Actinomycin D, C2 and VII, cyclic peptides, inhibited Grb2 SH2 domain association (IC50 5-7 microM) with a phosphotyrosine containing peptide derived from the Shc protein (pTyr317). Actinomycins are the first examples of nonphosphorylated natural ligands of SH2 domain.
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Affiliation(s)
- J Y Nam
- Korea Research Institute of Bioscience and Biotechnology, Taejon, Korea
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48
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Han MY, Huang W, Chew CH, Gan LM, Zhang XJ, Ji W. Large Nonlinear Absorption in Coated Ag2S/CdS Nanoparticles by Inverse Microemulsion. J Phys Chem B 1998. [DOI: 10.1021/jp972877z] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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49
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Abstract
Previously we and others have demonstrated that oxidative stress involving generation of reactive oxygen species (ROS) is responsible for the cytotoxic action of TNF alpha. Protective effect of small heat shock proteins (HSP) against diverse oxidative stress conditions has been suggested. Although overexpression of small HSP was shown to provide an enhanced survival of TNF alpha-sensitive cells when challenged with TNF alpha, neither the nature of TNF alpha-induced cytotoxicity nor the protective mechanism of small HSP has been completely understood. In this study, we have attempted to determine whether TNF alpha induces oxidative DNA damage in TNF alpha-sensitive L929 cells. We chose to measure the level of 8-hydroxy-2'-deoxyguanosine (8 ohdG), which has been increasingly recognized as one of the most sensitive markers of oxidative DNA damage. Our results clearly demonstrated that the level of 8 ohdG increased in L929 cells in a TNF alpha dose-dependent manner. Subsequently, we asked whether small HSP has a protective effect on TNF alpha-induced oxidative DNA damage. To accomplish this goal, we have stably transfected into L929 cells, which are devoid of endogenous small HSP, with the mouse small hsp cDNA (hsp25). We found that TNF alpha-induced 8 ohdG was decreased in cells overexpressing exogenous small HSP25. We also found that the cell-killing activity of TNF alpha was decreased in these cells as measured by clonogenic survival. Taken together, results from the current study show that a cytotoxic mechanism of TNF alpha involves oxidative damage of DNA, and that overexpression of the small HSP25 reduces this oxidative damage. We suggest that the reduction of oxidative DNA damage is an important protective mechanisms of small HSP against TNF alpha.
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Affiliation(s)
- Y M Park
- Department of Biology, Inchon University College of Natural Science, Korea
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50
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Abstract
We have developed a high throughput screening method for SH2 domain binding ligands and blockers. This method measures directly the binding of a 3H-labeled phosphopeptide derived from the sequence around tyrosine317 in the human Shc (SpYVNVK) to the SH2 domain of Grb2, which is precoated as glutathione S-transferase fusion proteins on solid phase. The optimum concentration for the fusion protein coating was 300 ng/100 microl/well for SH2 domain binding. Although an 8-h incubation at 4 degrees C for the coating of fusion protein was required to reach a maximum binding, even a 2-h coating produced 84% of the maximum binding. Saturation of ligand peptide binding in our assay system was observed at 10 pmol/well for the SH2 domain. However, 2 pmol/well showed consistent and reproducible results for the binding when the incubations were performed for 8 h at 4 degrees C. Competitive binding inhibition studies with various unlabeled phosphopeptides imply that the binding assay is highly specific to peptide sequences and able to screen possible ligands or blockers of signal transduction pathway mediated by Grb2 SH2 binding. In conclusion, our new method for SH2 domain binding is easy, rapid, and most of all inexpensive. These advantages over existing assay methods make this method especially suitable for a high throughput application, such as the screening for anticancer drug candidates.
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Affiliation(s)
- W S Koh
- Immune Regulation Research Unit, Korea Research Institute of Bioscience and Biotechnology, Yusung, Taejon, South Korea
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