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Woo SM, Min KJ, Seo BR, Nam JO, Choi KS, Yoo YH, Kwon TK. Cafestol overcomes ABT-737 resistance in Mcl-1-overexpressed renal carcinoma Caki cells through downregulation of Mcl-1 expression and upregulation of Bim expression. Cell Death Dis 2014; 5:e1514. [PMID: 25375379 PMCID: PMC4260730 DOI: 10.1038/cddis.2014.472] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/04/2014] [Accepted: 09/05/2014] [Indexed: 12/25/2022]
Abstract
Although ABT-737, a small-molecule Bcl-2/Bcl-xL inhibitor, has recently emerged as a novel cancer therapeutic agent, ABT-737-induced apoptosis is often blocked in several types of cancer cells with elevated expression of Mcl-1. Cafestol, one of the major compounds in coffee beans, has been reported to have anti-carcinogenic activity and tumor cell growth-inhibitory activity, and we examined whether cafestol could overcome resistance against ABT-737 in Mcl-1-overexpressed human renal carcinoma Caki cells. ABT-737 alone had no effect on apoptosis, but cafestol markedly enhanced ABT-737-mediated apoptosis in Mcl-1-overexpressed Caki cells, human glioma U251MG cells, and human breast carcinoma MDA-MB231 cells. By contrast, co-treatment with ABT-737 and cafestol did not induce apoptosis in normal human skin fibroblast. Furthermore, combined treatment with cafestol and ABT-737 markedly reduced tumor growth compared with either drug alone in xenograft models. We found that cafestol inhibited Mcl-1 protein expression, which is important for ABT-737 resistance, through promotion of protein degradation. Moreover, cafestol increased Bim expression, and siRNA-mediated suppression of Bim expression reduced the apoptosis induced by cafestol plus ABT-737. Taken together, cafestol may be effectively used to enhance ABT-737 sensitivity in cancer therapy via downregulation of Mcl-1 expression and upregulation of Bim expression.
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Bae DH, Choi KS, Yi HJ, Chun HJ, Ko Y, Bak KH. Cerebral Infarction after Traumatic Brain Injury: Incidence and Risk Factors. Korean J Neurotrauma 2014; 10:35-40. [PMID: 27169031 PMCID: PMC4852621 DOI: 10.13004/kjnt.2014.10.2.35] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 07/25/2014] [Accepted: 08/16/2014] [Indexed: 11/16/2022] Open
Abstract
Objective Post-traumatic cerebral infarction (PTCI) is one of the most severe secondary insults after traumatic brain injury (TBI), and is known to be associated with poor outcome and high mortality rate. We assessed the practical incidence and risk factors for the development of PTCI. Methods We conducted retrospective study on 986 consecutive patients with TBI from the period May 2005 to November 2012 at our institution. The definition of PTCI was made on non-enhanced CT scan based on a well-demarcated or fairly discernible region of low attenuation following specific vascular territory with normal initial CT. Clinical and radiological findings that related to patients' outcome were reviewed and statistically compared. Results PTCI was observed in 21 (2.1%) patients. Of various parameters, age (p=0.037), initial Glasgow coma scale score (p<0.01), brain herniation (p=0.044), and decompressive craniectomy (p=0.012) were significantly higher in patients with PTCI than patients who do not have PTCI. Duration between accident and PTCI, patterns of TBI and vascular territory of PTCI were not specific. The mortality rates were significantly higher in patients with PTCI than without PTCI. Conclusion The development of PTCI is rare after TBI, but it usually results in serious outcome and high mortality. Early recognition for risks and aggressive managements is mandatory to prevent PTCI.
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Bae DH, Kim JM, Won YD, Choi KS, Cheong JH, Yi HJ, Kim CH. Clinical outcome of paraclinoid internal carotid artery aneurysms after microsurgical neck clipping in comparison with endovascular embolization. J Cerebrovasc Endovasc Neurosurg 2014; 16:225-34. [PMID: 25340024 PMCID: PMC4205248 DOI: 10.7461/jcen.2014.16.3.225] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/15/2014] [Accepted: 09/04/2014] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE Because of the complex anatomical association among vascular, dural, and bony structures, paraclinoid internal carotid artery (ICA) aneurysms remain a major challenge for vascular neurosurgeons. We studied the clinical outcomes of 61 paraclinoid ICA aneurysms after microsurgical clipping in comparison with endovascular coiling. MATERIALS AND METHODS Between January 2008 and December 2012, we treated 61 paraclinoid ICA aneurysms created by surgical clipping or endovascular coiling. Preoperative neurologic status and postoperative outcome were evaluated using the Glasgow coma scale (GCS) and the modified Rankin scale (mRS). Postoperative hydrocephalus and vasospasm were reviewed using the patients' medical charts. RESULTS Most patients were in good clinical condition before the operations and had good treatment outcomes. Clinical vasospasm was observed after the operation in five patients, and hydrocephalus occurred in six patients. No statistically significant difference regarding aneurysm size, sex, GCS score, H-H grade, and mRS was observed between the surgical clipping group and the endovascular coiling group. In addition, the treatment results and complications did not show statistically significant difference in either group. CONCLUSION Surgical occlusion of paraclinoid ICA aneurysms is difficult; however, no significant differences were observed in the treatment results or complications when compared with coil embolization. In particular, use of an adequate surgical technique may lead to better outcomes than those for coil embolization in the treatment of large and/or wide-neck paraclinoid ICA aneurysms.
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Choi KS, Lee JH, Yi HJ, Chun HJ, Lee YJ, Kim DW. Incidence and risk factors of postoperative headache after endovascular coil embolization of unruptured intracranial aneurysms. Acta Neurochir (Wien) 2014; 156:1281-7. [PMID: 24801821 DOI: 10.1007/s00701-014-2095-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 04/02/2014] [Indexed: 11/25/2022]
Abstract
BACKGROUND Endovascular coil embolization for unruptured intracranial aneurysms (UIAs) has gained popularity because of its low morbidity and mortality in a short-term context. However, Headache is sometimes brought about or worsened after endovascular treatment, and this complaint may lead to perplexing situations, albeit infrequently. The aim of this study is to estimate the practical incidence and risk factors of postoperative headache in patients with endovascular embolization of UIAs. METHOD One hundred and thirty patients who underwent endovascular treatment of UIAs between March 2006 and May 2012 were enrolled according to inclusion criteria. From a retrospective chart review, the patients who had worsening or newly developed headache from postoperative day 1 to in-hospital stay were investigated for analyzing risk factors of post-embolization headache. Factors based on patients' demographics, anatomical and radiological features of the lesions, treatment, utilized devices and outcome were investigated, and statistically verified. RESULTS Headache occurred or was exacerbated in 32 patients (24.6 %). Of these, 30 patients showed improvement within days, but two patients with previous migraine history complained of intermittent headache over 3 months after the embolization. Univariate comparison between the headache group and the non-headache group showed that internal carotid artery (ICA) segment aneurysm, stent-assisted coiling, and no history of hypertension were associated with post-embolization headache (p < 0.05). However, stent-assisted coiling and no history of hypertension were significantly associated with post-embolization headache in logistic regression analysis (p < 0.05). CONCLUSIONS In the current study, stent-assisted coiling and no history of hypertension were important risk factors for headache in patients undergoing endovascular coil embolization for UIAs. Further investigations are still necessary to confirm the correlation of other factors which did not reach statistical significance in post-embolization headache in this limited study.
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Bae IS, Yi HJ, Choi KS, Chun HJ. Comparison of Incidence and Risk Factors for Shunt-dependent Hydrocephalus in Aneurysmal Subarachnoid Hemorrhage Patients. J Cerebrovasc Endovasc Neurosurg 2014; 16:78-84. [PMID: 25045646 PMCID: PMC4102754 DOI: 10.7461/jcen.2014.16.2.78] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 04/30/2014] [Accepted: 05/15/2014] [Indexed: 11/26/2022] Open
Abstract
Objective The objective of this study was to compare the incidence of ventricular shunt placement for shunt-dependent hydrocephalus (SDHC) after clipping versus coiling of ruptured aneurysms. Materials and Methods A retrospective review was conducted in 215 patients with aneurysmal subarachnoid hemorrhage (SAH) who underwent surgical clipping or endovascular coiling during the period from May 2008 to December 2011. Relevant clinical and radiographic data were analyzed with regard to the incidence of hydrocephalus and ventriculo-peritoneal shunt (VPS). Patients treated with clipping were assigned to Group A, while those treated with coiling were assigned to Group B. Results Of 215 patients (157 clipping, 58 coiling), no significant difference in the incidence of final VPS was observed between treatment modalities (15.3% vs. 10.3%) (p = 0.35). Independent risk factors for VPS for treatment of chronic hydrocephalus were as follows: (1) older than 65 years, (2) poorer Hunt-Hess grade IV and V, (3) Fisher grade III and IV, and (4) particularly initial presence of an intraventricular hemorrhage. Conclusion In this study comparing two modalities for treatment of aneurysm, there was no difference in the incidence of chronic hydrocephalus requiring VPS. A significantly higher rate of shunt dependency was observed for age older than 65 years, poor initial neurological status, and thick SAH with presence of initial intraventricular hemorrhage. By understanding these factors related to development of SDHC and results, it is expected that management of aneurysmal SAH will result in a better prognosis.
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Choi KS, Lee JH, Yi HJ, Chun HJ, Lee YJ, Kim DW. Erratum to: Incidence and risk factors of postoperative headache after endovascular coil embolization of unruptured intracranial aneurysms. Acta Neurochir (Wien) 2014. [DOI: 10.1007/s00701-014-2135-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Goban A, Hung CL, Yu SP, Hood JD, Muniz JA, Lee JH, Martin MJ, McClung AC, Choi KS, Chang DE, Painter O, Kimble HJ. Atom-light interactions in photonic crystals. Nat Commun 2014; 5:3808. [PMID: 24806520 DOI: 10.1038/ncomms4808] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 04/02/2014] [Indexed: 11/09/2022] Open
Abstract
The integration of nanophotonics and atomic physics has been a long-sought goal that would open new frontiers for optical physics, including novel quantum transport and many-body phenomena with photon-mediated atomic interactions. Reaching this goal requires surmounting diverse challenges in nanofabrication and atomic manipulation. Here we report the development of a novel integrated optical circuit with a photonic crystal capable of both localizing and interfacing atoms with guided photons. Optical bands of a photonic crystal waveguide are aligned with selected atomic transitions. From reflection spectra measured with average atom number N=1.1+/-0.4, we infer that atoms are localized within the waveguide by optical dipole forces. The fraction of single-atom radiative decay into the waveguide is Γ1D/Γ'≃(0.32±0.08), where Γ1D is the rate of emission into the guided mode and Γ' is the decay rate into all other channels. Γ1D/Γ' is unprecedented in all current atom-photon interfaces.
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Jeong MI, Choi YJ, Joa JH, Choi KS, Chung BN. First Report of Freesia sneak virus in Commercial Freesia hybrida Cultivars in Korea. PLANT DISEASE 2014; 98:162. [PMID: 30708612 DOI: 10.1094/pdis-05-13-0484-pdn] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In order to investigate the virus infection rate of commercial freesia cultivars in early February 2013, 19 freesia cultivars showing necrotic purple speckles or streaks on leaves, purple streaks parallel to the midrib, and necrotic speckles on leaves were collected from three different regions (Suwon and Icheon in Gyeonggi Province and Jeonju in North Jeonla Province) and used for virus detection. Nucleic acid extracts were analyzed for detection of major freesia-infecting viruses including Freesia sneak virus (FreSV) by reverse transcription (RT)-PCR with specific primer pairs. The FreSV CP gene was amplified using primer pair FreSV-F (5'-TTAGATAGTGAATCCATAAGCTGC-3') and FreSV-R (5'-ATGTCTGGAAAATACTCCGTCCAA-3'). The approximately 1.3-kb fragment of the FreSV amplified product was cloned and sequenced (GenBank Accession No. KC771891 to 98). The nucleotide sequences of CP gene of FreSV korean isolates showed 99.2 to 99.8% similarity to other FreSV isolates DQ885455, FJ807730, and GU071089, which are registered in GenBank. FreSV was detected from 71.7% of 138 plants tested while the infection rate of Freesia mosaic virus (FreMV) was 34.8%. Neither Bean yellow mosaic virus (BYMV) nor Tobacco rattle virus (TRV) were detected from any plants tested in this study. In certain cultivars, such as 'Bluebau' (II) and 'Pretty women,' most plants planted in the field showed purple streak symptoms on the leaves. In conclusion, FreSV was detected from some symptomatic freesia cultivars showing purple streak or speckles on leaves with or without necrotic spots and necrotic speckles on leaves. FreSV is currently widespread in Korea and some freesia plants were mixed infected with FreMV. FreSV has been occurring in the Netherlands for over 40 years (2). It is a plant virus in the family Ophioviridae and Ophiovirus genus. Once it occurs in freesia plantation fields, eradication is almost impossible because FreSV is transmitted by zoospores of Olpidium brassicae, which is a soilborne root-infecting fungus (3). Resting spores of O. brassicae can remain dormant in the soil and can be infective for 20 years (1). To produce virus-free freesia plants, growers should consider whether or not their fields are contaminated with O. brassicae carrying FreSV. To our knowledge, this is the first report of FreSV in freesia plants in Korea. References: (1) R. N. Campbell. Can. J. Bot. 63:2288, 1985. (2) Y. Koot et al. Tijdschrift over Plantenziekten 60:157, 1954. (3) H. J. M. van Dorst. Neth. J. Plant Pathol. 81:45, 1975.
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Ahn JY, Jung HY, Choi JY, Kim MY, Lee JH, Choi KS, Kim DH, Choi KD, Song HJ, Lee GH, Kim JH, Park YS. Natural course of noncurative endoscopic resection of differentiated early gastric cancer. Endoscopy 2012. [PMID: 23188661 DOI: 10.1055/s-0032-1325676] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND STUDY AIMS Following noncurative endoscopic resection of early gastric cancer (EGC), the patient should be observed when the underlying disease is severe, the patient is elderly, or the patient refuses further treatment. The aim of this study was to analyze the clinical outcomes of patients with differentiated EGC who underwent noncurative endoscopic resection without additional treatment. PATIENTS AND METHODS Included patients underwent noncurative endoscopic resection for differentiated EGC without additional treatment at the Asan Medical Center between July 1994 and January 2009. Clinical and oncological outcomes were analyzed. RESULTS A total of 159 patients were included in the analysis. The median follow-up period was 33 months (interquartile range [IQR] 22 - 52 months). In total, 40 patients died (25.2 %) - 3 due to stomach cancer, 34 due to other causes, and 3 from unknown causes; the median survival time after endoscopic treatment for these patients was 27.5 months (IQR 13.8 - 48.3 months). Multivariate analysis showed that the rates of underlying disease (P < 0.001) and lymphovascular invasion (P = 0.005) were higher among the 40 patients who died than among the 119 survivors. The overall 3- and 5-year survival rates were 82.9 % and 77.1 %, respectively; the rates of the patients with lymphovascular invasion were 61.9 % and 42.4 %, respectively, and the rates of patients without lymphovascular invasion were 86.1 % and 81.8 %, respectively (P < 0.001). CONCLUSIONS Additional treatment provides fewer benefits to patients who do not have long life expectancies. Additional surgery can be considered for patients with lymphovascular invasion because of its high mortality rate; however, the benefits and risks of surgery should be considered carefully.
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Choi KS, Kye SJ, Kim JY, Jeon WJ, Lee EK, Park KY, Sung HW. Epidemiological investigation of outbreaks of fowl adenovirus infection in commercial chickens in Korea. Poult Sci 2012; 91:2502-6. [PMID: 22991534 DOI: 10.3382/ps.2012-02296] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In total, 39 clinical cases of fowl adenoviruses (FAdV) infection in chickens (28 broiler, 7 native, and 4 layer chickens) between 2007 and 2010 in Korea were investigated. The FAdV types 4, 8b, and 11 comprised 18, 9, and 12 clinical cases, respectively. All FAdV type 4 cases showed clinical hydropericardium (HPS) lesions as well as inclusion body hepatitis (IBH), whereas all FAdV types 8b and 11 cases exhibited IBH lesions without HPS. All 3 types were detected in broiler (9-30 d old) and layer chickens (23-112 d old), whereas most native chickens (14-65 d old) were affected only by FAdV type 4. Infectious bursal disease virus and chicken infectious anemia virus were complications in 51.3% of FAdV cases, with mortalities of 55% to <0.1%. Chicken infectious anemia virus was detected in all native chicken cases. These results indicate that preventive measures against FAdV infection and immunosuppressive diseases on poultry farms should be implemented.
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Goban A, Choi KS, Alton DJ, Ding D, Lacroûte C, Pototschnig M, Thiele T, Stern NP, Kimble HJ. Demonstration of a state-insensitive, compensated nanofiber trap. PHYSICAL REVIEW LETTERS 2012; 109:033603. [PMID: 22861848 DOI: 10.1103/physrevlett.109.033603] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Indexed: 06/01/2023]
Abstract
We report the experimental realization of an optical trap that localizes single Cs atoms ≃215 nm from the surface of a dielectric nanofiber. By operating at magic wavelengths for pairs of counterpropagating red- and blue-detuned trapping beams, differential scalar light shifts are eliminated, and vector shifts are suppressed by ≈250. We thereby measure an absorption linewidth Γ/2π=5.7±0.1 MHz for the Cs 6S(1/2), F=4→6P(3/2), F'=5 transition, where Γ0/2π=5.2 MHz in free space. An optical depth d≃66 is observed, corresponding to an optical depth per atom d1≃0.08. These advances provide an important capability for the implementation of functional quantum optical networks and precision atomic spectroscopy near dielectric surfaces.
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Choi KS, Townson H. Evidence for X-linked introgression between molecular forms of Anopheles gambiae from Angola. MEDICAL AND VETERINARY ENTOMOLOGY 2012; 26:218-227. [PMID: 21933220 DOI: 10.1111/j.1365-2915.2011.00977.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The M and S molecular forms of the African malaria vector Anopheles gambiae (Diptera: Culicidae) are morphologically identical incipient species in which reproductive isolation is incomplete, enabling low-level gene flow between forms. In an attempt to find differences between the M and S forms, sequence variation was studied at loci along the X chromosome in adult female An. gambiae from Angola. A high proportion of M form specimens from Angola (79% of the 456 X chromosomes sampled) were found to contain a 16-bp insertion in intron 4 of the X-linked GPRCCK1 locus, relative to the AgamP3 release of the An. gambiae PEST genome sequence. The insertion was in Hardy-Weinberg equilibrium in Angolan M form populations. The same insertion was found in all S form specimens examined, regardless of where in Africa they were sampled, but was absent from a sample of M form specimens collected in Ghana, Bioko and Mali. In M form specimens from Angola, there was an association between alleles at the GPRCCK1 locus and those at a microsatellite locus, AGXH678, close to the centromere of the X chromosome, with significant linkage disequilibrium between loci separated by 0.472 Mbp (P < 0.033). We show that the insertion results from introgression from the S form into the M form, rather than from the retention of an ancestral character. Gene flow from the S to M form could allow genes of adaptive value to be transferred, including those conferring insecticide resistance and others influencing ecology and behaviour, and thus malaria transmission and control. We discuss factors that may have led to this introgression event.
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Chung YS, Gwak HS, Jung HW, Paek SH, Kim DG, Choi KS. A cranio-orbital-zygomatic approach to dumbbell-shaped trigeminal neurinomas using the petrous window. Skull Base 2011; 11:157-64. [PMID: 17167616 PMCID: PMC1656850 DOI: 10.1055/s-2001-16603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
We applied a cranio-orbital-zygomatic approach that extends the temporal craniotomy more posteriorly and minimizes the frontal orbitotomy of an ordinary orbitozygomatic approach in order to provide wide access to the already eroded petrous apices along the long axis of trigeminal neurinomas. We treated seven dumbbell-shaped trigeminal neurinomas between 1991 and 1998 (mean follow-up, 38 months; range, 9 to 109 months). The configuration of the tumor mass was assessed on magnetic resonance imaging by measuring its long diameter in the middle and posterior fossae and the width of petrous erosion. Tumors were then classified into five types based on their distribution over the petrous ridge. Total removal was achieved in six patients, who showed no evidence of tumor recurrence during the follow-up period. The only major complication was one case of anesthesia dolorosa. The one patient with a subtotal removal developed a recurrence 12 months after surgery, in the posterior fossa. The cranioorbital-zygomatic approach could be an effective method for removing dumbbell-shaped trigeminal neurinomas, particularly in cases of wide petrous erosion from the tumor. If, however, the tumor has a larger posterior fossa component, this approach may not provide adequate exposure to achieve a total resection.
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Jeon BY, Lee HY, Park EC, Choi KS, Jun JK, Kim Y, Han MA, Yoon NH, Kim EJ, Jeon SM. Satisfaction with mammography in the National Cancer Screening Programme participants of age 40s in Korea. Eur J Cancer Care (Engl) 2010; 20:803-9. [PMID: 20649810 DOI: 10.1111/j.1365-2354.2010.01210.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aim of this study was to evaluate satisfaction with the National Cancer Screening Programme of mammography in Korea and to examine the association between subscales of satisfaction and general satisfaction. We conducted a cross-sectional telephone survey for women who had obtained a National Cancer Screening Programme mammographic screening at general hospitals between May and October 2008. The present study included 2005 women in their forties. We performed multivariate linear regression using dependent variable as general satisfaction and independent variables as subscales of satisfaction, such as pre-screening information transfer, staff interpersonal skills, physical surroundings and results reporting. Participants were stratified according to the result of their mammogram as negative or positive. Mean score of satisfaction was above 2.5 of 4 for all subscales. Women who received positive results were less satisfied with all of subscale factors. Staff interpersonal skills were the most important factor that contributed to general satisfaction. Future efforts such as staff training programme of communication/attitude skills, ensuring privacy and explanation of possible discomfort of the screening would be needed.
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Han MA, Choi KS, Jun JK, Kim Y, Park EC, Lee HY. Factors associated with the intention to have colorectal cancer screening in Korean adults. Eur J Cancer Care (Engl) 2010; 20:475-82. [PMID: 20646036 DOI: 10.1111/j.1365-2354.2010.01209.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The purpose of this study was to investigate the factors related to screening intention in a population-based screening programme for colorectal cancer. The data were taken from the 2008 Korean National Cancer Screening Survey. We conducted a nationwide survey with trained interviewers using a questionnaire. A total of 2038 participants agreed to answer the survey. There were 955 study subjects aged ≥ 50 years in the target age group for colorectal cancer screening. Colorectal cancer screening behaviour and demographic characteristics were collected to evaluate intention for colorectal cancer screening and related factors. Descriptive statistics and multiple logistic regression were used in the analysis. The lifetime screening rate was 50.4% (50.9% for men and 49.8% for women). The screening rate with recommendation was 39.7% (39.3% for men and 40.1% of women). The odds ratios of intention to be screened increased significantly in younger subjects and those screened with double-contrast barium enema or colonoscopy. 'Without any symptoms' was reported as the most frequent reason for non-attendance or no intention to be screened. Age and recent screening methods were important factors related to intention to be screened for colorectal cancer. Further research is needed to identify remaining barriers to screening.
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Choi KS, Chun HJ, Yi HJ, Ko Y, Kim YS, Kim JM. Seizures and Epilepsy following Aneurysmal Subarachnoid Hemorrhage : Incidence and Risk Factors. J Korean Neurosurg Soc 2009; 46:93-8. [PMID: 19763209 DOI: 10.3340/jkns.2009.46.2.93] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Revised: 06/17/2009] [Accepted: 08/06/2009] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE Although prophylactic antiepileptic drug (AED) use in patients with aneurysmal subarachnoid hemorrhage (SAH) is a common practice, lack of uniform definitions and guidelines for seizures and AEDs rendered this prescription more habitual instead of evidence-based manner. We herein evaluated the incidence and predictive factors of seizure and complications about AED use. METHODS From July 1999 to June 2007, data of a total of 547 patients with aneurysmal SAH who underwent operative treatments were reviewed. For these, the incidence and risk factors of seizures and epilepsy were assessed, in addition to complications of AEDs. RESULTS Eighty-three patients (15.2%) had at least one seizure following SAH. Forty-three patients (7.9%) had onset seizures, 34 (6.2%) had perioperative seizures, and 17 (3.1%) had late epilepsy. Younger age (< 40 years), poor clinical grade, thick hemorrhage, acute hydrocephalus, and rebleeding were related to the occurrence of onset seizures. Cortical infarction and thick hemorrhage were independent risk factors for the occurrence of late epilepsy. Onset seizures were not predictive of late epilepsy. Moreover, adverse drug effects were identified in 128 patients (23.4%) with AEDs. CONCLUSION Perioperative seizures are not significant predictors for late epilepsy. Instead, initial amount of SAH and surgery-induced cortical damage should be seriously considered as risk factors for late epilepsy. Because AEDs can not prevent early postoperative seizures (< 1 week) and potentially cause unexpected side effects, long-term use should be readjusted in high-risk patients.
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Choi KS, Chun HJ, Yi HJ, Kim JT. Intracranial invasion from recurrent angiosarcoma of the scalp. J Korean Neurosurg Soc 2008; 43:201-4. [PMID: 19096645 DOI: 10.3340/jkns.2008.43.4.201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2007] [Accepted: 04/07/2008] [Indexed: 11/27/2022] Open
Abstract
Angiosarcoma of the brain, either primary or metastatic is extremely rare. Moreover, angiosarcoma metastasizing to the brain is also highly unlike to occur comparing with metastases to the other organs. Thus, an ideal treatment strategy has not been established. A 67-year-old man with past surgical history of a scalp angiosarcoma underwent surgical resection of intracranial invasion. Because of wide scalp flap excision and resultant poor vascularity of the scalp flap, additional radiation was not provided. Because adjuvant therapy is impossible due to poor scalp condition, more careful but ample resection of the primary lesion is essential to conduct initial operation.
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Cheung CY, Chan HW, Liu YL, Chan YH, Wong HS, Chak WL, Choi KS, Chau KF, Li CS. Prevalence of metabolic syndrome in Chinese renal transplant recipients. Hong Kong Med J 2008; 14:379-384. [PMID: 18840909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
OBJECTIVE To investigate the prevalence of metabolic syndrome in Chinese renal transplant recipients, using two different sets of diagnostic criteria. DESIGN Cross-sectional study. SETTING Regional hospital, Hong Kong. PATIENTS All Chinese patients who received solitary living-related or cadaveric kidney transplantation from 1 July 1997 to 31 December 2005 in our hospital with follow-up of more than 6 months were recruited. The diagnosis of metabolic syndrome was made according to the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) criteria and the International Diabetes Federation criteria. RESULTS Using the modified (Asian) NCEP-ATPIII criteria, a total of 39 (32%) of 121 patients had metabolic syndrome, which included 20/69 (29%) of the males and 19/52 (37%) of the females. Using the International Diabetes Federation criteria, metabolic syndrome was diagnosed in 26% of the patients, 22% in males and 31% in females. In our patients, the most common component of metabolic syndrome was hypertension and the least common was low high-density-lipoprotein-cholesterol level. Low high-density-lipoprotein-cholesterol levels were significantly more common in female patients. CONCLUSION This study shows that there is a high prevalence of metabolic syndrome in our Chinese renal transplant recipients.
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Dyer NA, Lawton SP, Ravel S, Choi KS, Lehane MJ, Robinson AS, Okedi LM, Hall MJR, Solano P, Donnelly MJ. Molecular phylogenetics of tsetse flies (Diptera: Glossinidae) based on mitochondrial (COI, 16S, ND2) and nuclear ribosomal DNA sequences, with an emphasis on the palpalis group. Mol Phylogenet Evol 2008; 49:227-39. [PMID: 18692147 DOI: 10.1016/j.ympev.2008.07.011] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 07/08/2008] [Accepted: 07/13/2008] [Indexed: 11/16/2022]
Abstract
Relationships of 13 species of the genus Glossina (tsetse flies) were inferred from mitochondrial (cytochrome oxidase 1, NADH dehydrogenase 2 and 16S) and nuclear (internal transcribed spacer 1 of rDNA) sequences. The resulting phylogeny confirms the monophyly of the morphologically defined fusca, morsitans and palpalis subgenera. Genetic distances between palpalis and morsitans subspecies suggest that their status needs revision. In particular, cytochrome oxidase 1 sequences showed large geographical differences within G. palpalis palpalis, suggesting the existence of cryptic species within this subspecies. The morphology of palpalis group female genital plates was examined, and individuals were found varying outside the ranges specified by the standard identification keys, making definitive morphological classification impossible. A diagnostic PCR to distinguish G. palpalis palpalis, G. tachinoides and G. palpalis gambiensis based on length differences of internal transcribed spacer 1 sequences is presented.
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Qin J, Choi KS, Ho SSM, Heng PA. An adaptive transmission protocol for managing dynamic shared states in collaborative surgical simulation. Stud Health Technol Inform 2008; 132:387-389. [PMID: 18391327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A force prediction algorithm is proposed to facilitate virtual-reality (VR) based collaborative surgical simulation by reducing the effect of network latencies. State regeneration is used to correct the estimated prediction. This algorithm is incorporated into an adaptive transmission protocol in which auxiliary features such as view synchronization and coupling control are equipped to ensure the system consistency. We implemented this protocol using multi-threaded technique on a cluster-based network architecture.
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Laurat J, Choi KS, Deng H, Chou CW, Kimble HJ. Heralded entanglement between atomic ensembles: preparation, decoherence, and scaling. PHYSICAL REVIEW LETTERS 2007; 99:180504. [PMID: 17995390 DOI: 10.1103/physrevlett.99.180504] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2007] [Indexed: 05/25/2023]
Abstract
Heralded entanglement between collective excitations in two atomic ensembles is probabilistically generated, stored, and converted to single-photon fields. By way of the concurrence, quantitative characterizations are reported for the scaling behavior of entanglement with excitation probability and for the temporal dynamics of various correlations resulting in the decay of entanglement. A lower bound of the concurrence for the collective atomic state of 0.9+/-0.3 is inferred. The decay of entanglement as a function of storage time is also observed, and related to the local dynamics.
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Sung NY, Choi KS, Park EC, Park K, Lee SY, Lee AK, Choi IJ, Jung KW, Won YJ, Shin HR. Smoking, alcohol and gastric cancer risk in Korean men: the National Health Insurance Corporation Study. Br J Cancer 2007; 97:700-4. [PMID: 17637680 PMCID: PMC2360367 DOI: 10.1038/sj.bjc.6603893] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 06/20/2007] [Accepted: 06/27/2007] [Indexed: 01/02/2023] Open
Abstract
We investigated the risk of gastric cancer by subsite in relation to cigarette smoking and alcohol in a large population-based cohort of 669 570 Korean men in an insurance plan followed for an average 6.5 years, yielding 3452 new cases of gastric cancer, of which 127 were cardia and upper-third gastric cancer, 2409 were distal gastric cancer and 1007 were unclassified. A moderate association was found between smoking, cardia and upper-third (adjusted relative risk (aRR) 2.2; 95% confidence interval (CI) 1.4-3.5) and distal cancers (aRR=1.4; 95% CI=1.3-1.6). We also found a positive association between alcohol consumption and distal (aRR=1.3; 95% CI=1.2-1.5) and total (aRR=1.2; 95% CI=1.1-1.4) gastric cancer. Combined exposure to high levels of tobacco and alcohol increased the risk estimates further; cardia and upper-third gastric cancers were more strongly related to smoking status than distal gastric cancer.British Journal of Cancer (2007) 97, 700-704. doi:10.1038/sj.bjc.6603893 www.bjcancer.com Published online 17 July 2007.
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Lim JH, Park JW, Min DS, Chang JS, Lee YH, Park YB, Choi KS, Kwon TK. NAG-1 up-regulation mediated by EGR-1 and p53 is critical for quercetin-induced apoptosis in HCT116 colon carcinoma cells. Apoptosis 2007; 12:411-21. [PMID: 17191121 DOI: 10.1007/s10495-006-0576-9] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Quercetin, a flavonoid molecule ubiquitously present in nature, has multiple effects on cancer cells, including the inhibition of cell proliferation and migration. However, the responsible molecular mechanisms are not fully understood. We found that quercetin induces the expression of NAG-1 (Non-steroidal anti-inflammatory drug activated gene-1), a TGF-beta superfamily protein, during quercetin-induced apoptosis of HCT116 human colon carcinoma cells. Reporter assays using the luciferase constructs containing NAG-1 promoter region demonstrate that early growth response-1 (EGR-1) and p53 are required for quercetin-mediated activation of the NAG-1 promoter. Overexpression of NAG-1 enhanced the apoptotic effect of quercetin, but suppression of quercetin-induced NAG-1 expression by NAG-1 siRNA attenuated quercetin-induced apoptosis in HCT116 cells. Taken together, the present study demonstrates for the first time that quercetin induces apoptosis via NAG-1, providing a mechanistic basis for the apoptotic effect of quercetin in colon carcinoma cells.
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Qin J, Heng PA, Choi KS, Ho SSM. An adaptive framework using cluster-based hybrid architecture for enhancing collaboration in surgical simulation. Stud Health Technol Inform 2007; 125:367-72. [PMID: 17377305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Research on collaborative virtual surgery opens the opportunity for simulating the cooperative work during surgical operations. It is however a challenging task to design and implement a high performance collaborative surgical simulation system because of the difficulty in maintaining a high level of state consistency under limited network transmission capacity. In this paper, we present an adaptive framework using cluster-based hybrid architecture to support real-time collaboration in surgical simulation. In addition to the TCP communication protocol, the framework is also equipped with UDP for multicasting, allowing for a flexible strategy to reduce network latency. A set of techniques was proposed to assure reliable transmission on top of standard yet unreliable multicast protocols. Experimental results demonstrate that this framework can support collaborative surgical simulation with lower network latencies than traditional client-server architecture.
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Seo Y, Qin Y, Vicente CL, Choi KS, Yoon J. Origin of nonlinear transport across the magnetically induced superconductor-metal-insulator transition in two dimensions. PHYSICAL REVIEW LETTERS 2006; 97:057005. [PMID: 17026135 DOI: 10.1103/physrevlett.97.057005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Indexed: 05/12/2023]
Abstract
We have studied the effect of perpendicular magnetic fields and temperatures on nonlinear electronic transport in amorphous Ta superconducting thin films. The films exhibit a magnetic field-induced metallic behavior intervening the superconductor-insulator transition in the zero temperature limit. We show that the phase-identifying nonlinear transport in the superconducting and metallic phases arises from an intrinsic origin, not from an electron heating effect. The nonlinear transport is found to accompany an extraordinarily long voltage response time.
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Kim SJ, Jeong HJ, Kim BK, Kim NH, Kim JS, Choi KS, Lee HJ, Kang ST, Shin SS, Kim WI, Eom HS, Lee KM, Um JY, Hong SH, Kim HM. Anti-inflammatory effect of jeongshintang through suppression of p38 activation in human astrocytoma, U373MG cells. Exp Mol Pathol 2006; 81:85-91. [PMID: 16698013 DOI: 10.1016/j.yexmp.2005.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Revised: 11/18/2005] [Accepted: 12/01/2005] [Indexed: 01/22/2023]
Abstract
Jeongshintang (JST) is a Korean herbal prescription, which has been successfully used for cerebral diseases. However, the anti-inflammatory effect of JST on Alzheimer's disease (AD) is still not fully understood. In this study, we investigated the effects of JST in attenuating the inflammatory response induced by interleukin (IL)-1beta plus beta-amyloid [1-42] fragment (A beta) in the human astrocyte cell line, U373MG. The production of IL-6, IL-8, and prostaglandin (PG)E2 was significantly increased by IL-1beta plus A beta (1-42) in a time-dependent manner (P < 0.05). JST significantly inhibited the IL-1beta plus A beta (1-42)-induced IL-6, IL-8, and PGE2 production at 24 h (P < 0.05). Maximal inhibition rate of IL-6, IL-8, and PGE2 production by JST was about 54.40%, 56.01%, and 44.06% respectively. JST (0.01-1 mg/ml) also attenuated the expression of cyclooxygenase (COX)-2 and activation of p38 MAPK induced by IL-1beta and A beta (1-42). These results demonstrated that JST has an anti-inflammatory effect, which might explain its beneficial effect in the treatment of various neurodegenerative diseases such as AD.
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Poo KM, Im JH, Jun BH, Kim JR, Hwang IS, Choi KS, Kim CW. Full-cyclic control strategy of SBR for nitrogen removal in strong wastewater using common sensors. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2006; 53:151-60. [PMID: 16722065 DOI: 10.2166/wst.2006.119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A full-cyclic automatic control strategy for sequencing batch reactors (SBR) was proposed using only common sensors such as ORP, DO and pH. The main objective was to develop a generally applicable and robust control strategy. To accomplish this, various control schemes found in the literature or suggested by authors were examined at diverse ammonia loads and SCOD/NH4(+)-N ratios. Advantages and constraints of each scheme were discussed and compared. Ammonia load was estimated with DO lag time during the aerobic stage, and then the influent pump was manipulated to meet the desired load at the next anoxic stage. A partial denitrification scheme was chosen for the anoxic stage period control, to save anoxic time and external carbon. For external carbon dosage control, intermittent feeding at each anoxic stage was concluded to be a suitable scheme. The anoxic stage period could be successfully controlled by the combination of pH increase and DO increase. Every suggested control scheme was incorporated into a full-cyclic control strategy and tested at 0.02, 0.035, 0.08 kg NH4(+)-N/m3/sub-cycle. From the results, it is expected to perform unmanned automatic SBR operation with this strategy.
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Cheung CY, Wong F, Chan HW, Liu YL, Chan YH, Wong HS, Chak WL, Choi KS, Chau KF, Li CS. A Single Center and Paired Kidney Analysis of Tacrolimus and Neoral-based Therapy in Chinese Cadaveric Renal Transplant Recipients. Int J Organ Transplant Med 2005. [DOI: 10.1016/s1561-5413(09)60207-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Cheung CY, Wong F, Liu YL, Chan HW, Chan YH, Wong HS, Chak WL, Choi KS, Chau KF, Li CS. A Single Center Study of CAPD Catheter Placement Using the Seldinger Technique. Int J Organ Transplant Med 2005. [DOI: 10.1016/s1561-5413(09)60191-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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80
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Wong KM, Liu YL, Leung KT, Choi KS, Chau KF, Li PCK, Li CS, Lee KC, Cheung CY, Chan YH, Lee MP. Corticosteroid therapy in a Chinese patient with nephropathy associated with human immunodeficiency virus infection. Hong Kong Med J 2004; 10:201-5. [PMID: 15181226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
A 52-year-old man with 6 years' history of human immunodeficiency virus infection who was receiving highly active antiretroviral therapy presented with acute renal failure and nephrotic syndrome. Renal biopsy revealed features consistent with nephropathy associated with human immunodeficiency virus infection. Treatment consisted of intravenous methylprednisolone followed by oral prednisolone. The patient's renal function improved, although proteinuria persisted. Human immunodeficiency virus-associated nephropathy is very rare in Asian populations and is more common among blacks. To the best of our knowledge, this is the first documented case of nephropathy associated with human immunodeficiency virus infection occurring in Hong Kong.
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Chak WL, Choi KS, Wong KM, Chan YH, Chau KF, Li CS. Pharmacoeconomic analysis of preemptive gancyclovir therapy in the prevention of cytomegalovirus infections in high-risk renal graft recipients. Transplant Proc 2003; 35:280-1. [PMID: 12591399 DOI: 10.1016/s0041-1345(02)03892-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Song MS, Kong ES, Kim GB, Kim NC, Kim CH, Kim CK, Kim HK, Roh YJ, Shin KR, Ahn SY, Lee KJ, Lee YW, Chang SO, Chon SJ, Cho NO, Cho MO, Choi KS. Development of Gerontological Nursing Curriculum Model. J Korean Acad Nurs 2003; 33:376-85. [PMID: 15314436 DOI: 10.4040/jkan.2003.33.3.376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
PURPOSE This study was conducted to develop gerontological curriculum model which reflects the need of Korean society. METHOD Three round Delphi survey method was applied to find consensus of gerontological nursing competencies (knowledge, attitudes and skills) for graduates of nursing schools from the panel of gerontological nursing practice experts. Important concepts in gerontological nursing were delineated from literature review and discussions of gerontological nursing educators. Based on these results the gerontological nursing curriculum model was developed and course structure outlined by the researchers as a group. RESULT As the result of delphi survey, 32 items of knowledge, 29 items of attitude, and 21 items of skill were identified. The curriculum model constructed around a cube with three plane- functional capacity levels, settings, and nursing practice. Specific knowledge, attitudes and skills for gerontological theory and practicum course were suggested. Competency items were assigned to theory and/or practice. CONCLUSION A curriculum model for gerontological nursing has been developed by a group of gerontological nursing educators. The curriculum model should be further tested and developed with detailed theory and practicum course outline and textbooks.
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Kim NR, Choe G, Shin SH, Wang KC, Cho BK, Choi KS, Chi JG. Childhood meningiomas associated with meningioangiomatosis: report of five cases and literature review. Neuropathol Appl Neurobiol 2002; 28:48-56. [PMID: 11849563 DOI: 10.1046/j.1365-2990.2002.00365.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Meningioangiomatosis is a unique, rare hamartomatous lesion. Meningiomas arising in the background of meningioangiomatosis are rare conditions which pathologically and radiologically mimic invasive meningiomas, but have a benign clinical course in children and young adults. In this study, five such cases are reported. To our knowledge, this is the largest reported collection of meningiomas associated with meningioangiomatosis. Less immunoreactivity for progesterone receptor and high Ki-67 labelling index are generally known to be associated with invasive meningiomas. However, high expression of progesterone receptor and low Ki-67 labelling index in the present cases supports the idea that brain invasion is not an indicator of malignancy but an independent finding associated with meningiomas which have arisen from meningioangiomatosis. We emphasize the good prognosis of such tumours and discuss pathogenesis of meningiomas with meningioangiomatosis.
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Shin KR, Kong ES, Kim GB, Kim NC, Kim CH, Kim CK, Kim HK, Ro YJ, Song MS, Ahn SY, Lee KJ, Lee YW, Chang SO, Chon SJ, Cho NO, Cho MO, Choi KS. Lived Experience with Aging in Middle-Aged Woman. J Korean Acad Nurs 2002. [DOI: 10.4040/jkan.2002.32.6.878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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85
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Park MK, Choi KS, Kim MC, Chae JS. Differential diagnosis of Salmonella gallinarum and S. pullorum using PCR-RELP. J Vet Sci 2001; 2:213-9. [PMID: 12441691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023] Open
Abstract
Salmonellosis in poultry of Korea is a significant health problem, which causes substantial economic losses. The most common causative agents of chicken salmonellosis ar S. gallinarum and S. pullorum. Traditional methods used to detect Salmoenella spp. In chicken are tedious, time consuming and confer little guarantee of sensitivity and species specificity. Therefore, a rapid and sensitive method for the differentiation of Salmonella serogroup D was assessed. We first amplified the rfbS genes by PCR and characterized the amplified product by nucleotide sequence analysis. The homology of nucleotide sequence was 99.7% between S. gallinarum and S. pullorum rfbS genes. Further comparisons of the sequences of S. gallinarum, S. gallinarum fied strain, S. pullorum and S. typhi(GenBank Accession No.M29682) showed a homology of 98.3%. The predicted amino acid sequence homology was 97.1%, 97.1% and 97.5%, respectively. Based on this comparison of these nucleotide sequences, we found unique restriction enzyme sites within the rfbS genes of S. gallinarum and S. pullorum. Thus, the PCR products could be further digested with restriction enzymes TfiI and PleI for use in a restriction fragment length polymorphism (RELP) technique. This method can be applied in the differential diagnosis between S. gallinarum and S. pullorum.
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Song KB, Choi KS, Lang WP, Jacobson JJ. Hepatitis B prevalence and infection control among dental health care workers in a community in South Korea. J Public Health Dent 2001; 59:39-43. [PMID: 11396043 DOI: 10.1111/j.1752-7325.1999.tb03233.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The objectives of this study were to investigate the prevalence of hepatitis B vaccine and use of infection control procedures by dental health care workers in Taegu, South Korea. METHODS Information was obtained with a mailed questionnaire sent to 300 private dental practices. Surveys were received from 177 dentists, 104 dental hygienists, and 46 dental assistants. All dental health care workers were asked to donate a blood sample for analysis of hepatitis B surface antigen (HBsAg) and antibody (anti-HBs). RESULTS Vaccination against hepatitis B virus was reported by 63 percent of the respondents. About 40 percent of all participants answered that they were anti-HBs positive, while another 43 percent did not know their status. About 89 percent of dentists reported that they wore a mask with all patients, while hygienists (13.6%) and assistants (13.0%) were less likely to do so. Reported use of gloves (4.5%) and protective eyewear (14%) with all patients was extremely low in every group. Among the 56 dentists who were tested for HBV markers, 23 did not receive the vaccine against hepatitis B, and 13 percent (3 of 23) were positive for HBsAg as carriers. CONCLUSIONS About 37 percent (120 of 327) of dental health care workers surveyed in this study in Korea did not receive the vaccine against HBV infection. Basic barrier techniques to prevent cross-contamination were not being used consistently. Nationwide guidelines for barrier techniques and hepatitis vaccinations should be developed and disseminated to dental personnel.
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Park SA, Park HJ, Lee BI, Ahn YH, Kim SU, Choi KS. Bcl-2 blocks cisplatin-induced apoptosis by suppression of ERK-mediated p53 accumulation in B104 cells. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2001; 93:18-26. [PMID: 11532334 DOI: 10.1016/s0169-328x(01)00176-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bcl-2 has been reported to inhibit neurotoxicity induced by cisplatin. However, neither the mechanism of cisplatin-induced neurotoxicity nor the mechanism by which Bcl-2 confers neuroprotection is clear. In this study, the signaling pathways involved in cisplatin-induced neurotoxicity were examined using a rat neuroblastoma cell line, B104. Treatment of B104 cells with cisplatin induced apoptosis, accompanying the accumulation of p53 and Bax protein. Interestingly, extracellular signal-regulated kinase 1/2 (ERK1/2) activities of MAP kinases were markedly enhanced prior to cisplatin-induced accumulation of p53 and Bax. Inhibition of ERK1/2 activities using PD98059, a selective MEK inhibitor, blocked the apoptotic cell death preventing cisplatin-induced accumulation of p53 and Bax. These results suggest that ERK mediates cisplatin-induced p53 activation to trigger apoptosis in B104 cells. Overexpression of Bcl-2 in B104 cells resulted in the complete resistance to cisplatin-induced apoptosis blocking ERK activation and the subsequent signaling pathway of p53. Our study clearly demonstrates that the action site of Bcl-2 localizes upstream of ERK in cisplatin-induced apoptotic signaling pathway.
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Kuh SE, Kim JW, Kim DS, Choi KS. Extraction of metal values from manganese nodules in the ocean environment using zinc matte as a reductant. ENVIRONMENTAL TECHNOLOGY 2001; 22:881-887. [PMID: 11561945 DOI: 10.1080/09593332208618227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The leaching process of manganese nodules in the marine environment is significant in the recovery of several metal values. In this experiment, reduction leaching of manganese nodules was carried out using zinc matte as a reductant in dilute HCl solution. The leaching characteristics of Mn, Co, Ni, and Cu from manganese nodules depended on the leaching temperature and initial HCl concentration. A temperature of approximately 70 degrees C was suitable for the present reduction leaching, and the extraction rate increased with increase in the initial HCl concentration. More than 97% of Mn, 92% of Co, and 88% of Ni were easily extracted. The dissolution of Mn, Co, Ni, and Cu depended upon the amount of zinc matte added. The ratio of liquid and solid was also an important factor in the extraction of manganese nodules. As the liquid/solid (L/S, lixiviant/manganese nodule) ratio was increased, the extraction rate increased. The extraction rate was independent of stirring speed.
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Wong KM, Chak WL, Cheung CY, Chan YH, Choi KS, Chau KF, Li CS. Hypokalemic metabolic acidosis attributed to cough mixture abuse. Am J Kidney Dis 2001; 38:390-4. [PMID: 11479167 DOI: 10.1053/ajkd.2001.26107] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This report describes a patient with mixed normal anion gap hyperchloremic metabolic and respiratory acidosis associated with hypokalemia attributed to cough mixture abuse. Metabolic acidosis was likely related to an overdose of ammonium chloride, whereas respiratory acidosis was probably related to the effect of hypokalemia on respiratory muscles, causing hypoventilation. Hypokalemia was caused by a transcellular shift of potassium induced by ephedrine and pseudoephedrine. Both ammonium chloride and ephedrine were probably present in the cough mixture obtained by our patient as an over-the-counter medication. Physicians should be aware of the potential for cough mixture abuse to cause major electrolyte disturbances that may carry the risk for major cardiac arrhythmias, particularly in youth.
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Choi KS, Fitzpatrick SL, Filipenko NR, Fogg DK, Kassam G, Magliocco AM, Waisman DM. Regulation of plasmin-dependent fibrin clot lysis by annexin II heterotetramer. J Biol Chem 2001; 276:25212-21. [PMID: 11319229 DOI: 10.1074/jbc.m101426200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In a previous report we showed that plasmin-dependent lysis of a fibrin polymer, produced from purified components, was totally blocked if annexin II heterotetramer (AIIt) was present during fibrin polymer formation. Here, we show that AIIt inhibits fibrin clot lysis by stimulation of plasmin autodegradation, which results in a loss of plasmin activity. Furthermore, the C-terminal lysine residues of its p11 subunit play an essential role in the inhibition of fibrin clot lysis by AIIt. We also found that AIIt binds to fibrin with a K(d) of 436 nm and a stoichiometry of about 0.28 mol of AIIt/mol of fibrin monomer. The binding of AIIt to fibrin was not dependent on the C-terminal lysines of the p11 subunit. Furthermore, in the presence of plasminogen, the binding of AIIt to fibrin was increased to about 1.3 mol of AIIt/mol of fibrin monomer, suggesting that AIIt and plasminogen do not compete for identical sites on fibrin. Immunohistochemical identification of p36 and p11 subunits of AIIt in a pathological clot provides important evidence for its role as a physiological fibrinolytic regulator. These results suggest that AIIt may play a key role in the regulation of plasmin activity on the fibrin clot surface.
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Wong KM, Chan YH, Cheung CY, Chak WL, Choi KS, Leung SH, Leung J, Chau KF, Tsang DN, Li CS. Cefepime versus vancomycin plus netilmicin therapy for continuous ambulatory peritoneal dialysis-associated peritonitis. Am J Kidney Dis 2001; 38:127-31. [PMID: 11431192 DOI: 10.1053/ajkd.2001.25205] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cefepime is a cephalosporin with a broad spectrum of activity against most gram-positive and gram-negative pathogens. In this study, we attempted to compare the safety and efficacy of cefepime monotherapy against the potentially more toxic combination of vancomycin and netilmicin in the treatment of continuous ambulatory peritoneal dialysis (CAPD)-associated bacterial peritonitis. Eighty-one consecutive CAPD patients who presented with peritonitis from January 1, 1998, to June 30, 2000, were recruited for study. Patients were randomized to be administered either intraperitoneal (IP) cefepime, 1 g once daily (group A), or intravenous vancomycin and netilmicin at conventional doses (group B) for 10 days. Bacterial growth was obtained in 52 episodes (66%), and pathogens identified included gram-positive organisms (30 episodes; 38%), gram-negative organisms (14 episodes; 18%), mixed organisms (2 episodes; 2.5%), and fungus (6 episodes; 8%). Eight patients were excluded after randomization for various reasons (6 patients, fungal peritonitis; 2 patients, wrong diagnoses). Because of the relatively low peritonitis rate after the use of a disconnect system, the sample size of this study was relatively small, giving a power of 0.45. There were no significant differences in primary response rates and cure rates (no relapse >28 days after completion of antibiotic therapy) between both groups of patients (group A versus group B, 82% [32 of 39 patients] versus 85% [29 of 34 patients] and 72% [28 of 39 patients] versus 76% [26 of 34 patients], respectively; P = not significant). No significant side effect was encountered in either group. Total peritonitis-related hospitalizations were 84 patient-days (1, 7, 8, 11, 20, and 37 patient-days) and 115 patient-days (3, 6, 9, 14, 21, 21, and 41 patient-days), whereas total costs per patient cure were estimated to be US $1,039 and US $1,371 in groups A and B, respectively. We conclude that once-daily 1-g IP cefepime monotherapy is a simple, safe, and cost-effective alternative to vancomycin and netilmicin therapy in the treatment of CAPD-associated bacterial peritonitis.
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92
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Park S, Choi KS, Joe KS, Kim WH, Kim HS. Variations of landfill leachate's properties in conjunction with the treatment process. ENVIRONMENTAL TECHNOLOGY 2001; 22:639-645. [PMID: 11482383 DOI: 10.1080/09593332208618244] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A study was done on the variations of water quality parameters, in conjunction with the processing steps, installed for the treatment of leachate from a sanitary landfill. The leachate was primarily subjected to biological treatment, composed of anaerobic digestion, aerobic treatment, and rotating biological contact in series. The effluent from the rotating biological contact process was further treated by combination of flocculation-sedimentation and adsorption processes. Finally, it was polished by the reverse osmosis process before discharge. The quality of raw leachate, of influents to and of effluents from the reverse osmosis process was assessed and compared. To determine size--dependent behavior of organic materials, analyses were also made for the fractionated samples through ultrafiltration. The overall treatment efficiency was about 98% for removal of organic materials. Most of the organic materials were in the low molecular weight range. In particular, about 95% of the biological oxygen demand was found to be exerted by the fraction of organic material of which cut -off molecular weight was less than 500. The analysis of molecular weight distribution confirmed that the organic materials resistant to the removal by the treatment process were humic substances, of which cut off molecular weight was greater than 500. The reverse osmosis process showed a high efficiency for removal of high molecular weight constituents. However, the final effluent showed an unexpectedly high oxygen demand.
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93
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Kim DJ, Kang JS, Ahn B, Kim KS, Park KH, Choi KS, Surh YJ, Kim ND. Chemopreventive effect of 2-(allylthio)pyrazine (2-AP) on rat colon carcinogenesis induced by azoxymethane (AOM). Cancer Lett 2001; 166:125-33. [PMID: 11311484 DOI: 10.1016/s0304-3835(01)00408-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An investigation was conducted to assess the chemopreventive effects of 2-(allylthio)pyrazine (2-AP), synthesized for potential use as a chemopreventive agent, after administration during the pre-initiation and post-initiation stages in a rat colon carcinogenesis model with azoxymethane (AOM). One hundred, 5-week-old, male F344 rats were randomly divided into two experiments (n = 50 each). Experiment 1 rats were randomly divided into three groups: Group 1 rats were pre-treated with 2-AP (25 or 50 mg/kg body weight, 3 consecutive days through the route of intragastric intubations) before AOM (20 mg/kg body weight, single subcutaneous (s.c.) injection) initiation. Group 2 rats were treated with AOM alone. Group 3 rats were given 2-AP alone without AOM initiation. The animals were killed at the end of each experiment (week 5) and the aberrant crypt foci (ACF) of the colonic mucosa were assessed after staining with methylene blue. Experiment 2 rats were randomly divided into three groups: Group 1 rats were given 2-AP (10, 25 or 50 mg/kg body weight, five-times intragastric intubations per week for 5 weeks from week 3) after AOM (15 mg/kg body weight, three s.c. injections) initiation for 2 weeks. Group 2 rats were treated with AOM alone. Group 3 rats were given 2-AP alone without AOM initiation. The animals were killed at the end of the experiment (week 8) and the ACF of the colonic mucosa were quantified. Total numbers of ACF/colon in Group 1 rats (pre-treated with 2-AP) tended to decrease (2-AP, 50 mg/kg body weight) or increase (2-AP, 100 mg/kg body weight) depending on the dose level. Total numbers of ACF/colon in Group 1 rats (treated with AOM followed by 2-AP, all subgroups; 160.8 +/- 38.0; 161.8 +/- 38.1; 137.1 +/- 48.4) were decreased significantly compared with the values in Group 2 rats (AOM alone; 214.8 +/- 48.1) (P < 0.05 or 0.01). The highest dose group (2-AP, 50 mg/kg body weight) had the lowest levels of total numbers of ACF/colon among the three subgroups. Total numbers of aberrant crypts (AC)/colon of the highest dose group (340.1+/- 117.9) decreased significantly compared with the value for Group 2 rats (AOM alone; 545.1 +/- 38.3). These results thus suggest that 2-AP may have potential as a chemopreventive agent against rat colon carcinogenesis after administration of AOM during the post-initiation stage.
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94
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Yoon CY, Hong CM, Song JY, Cho YY, Choi KS, Lee BJ, Kim CK. Effect of ethylene glycol monoethyl ether on the spermatogenesis in pubertal and adult rats. J Vet Sci 2001; 2:47-51. [PMID: 14614294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023] Open
Abstract
The effects of ethylene glycol monoethyl ether (EGEE) on testicular cell populations in pubertal (5 weeks old) and adult (9 weeks old) male rats were investigated by a flow cytometric method. A total of 50 rats (in number, 25 pubertal and 25 adult rats) was divided into 5 experimental groups including 0 (control), 50, 100, 200, and 400 mg EGEE/kg of body weight. The animals were administered by gavage for 4 weeks. In adult rats, the treatment of EGEE at the dose of 400 mg/kg of body weight decreased significantly the populations of haploid, while it increased those of diploid and tetraploid cells. In pubertal rats, the treatment of EGEE at the dose of 400 mg/kg of body weight caused only minimal changes in the relative percent of testicular cell types. These results suggest that the effects of EGEE on testicular function in pubertal rats appear to be less pronounced than in adult rats.
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95
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Cheng YL, Choi KS, Chau KF, Li CS, Yung CU, Yu AW, Wong KK. Urea reduction ratio that considers effects of ultrafiltration and intradialytic urea generation. Am J Kidney Dis 2001; 37:544-9. [PMID: 11228178 DOI: 10.1053/ajkd.2001.22078] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We modified the urea reduction ratio (URR) equation to correct the effects of ultrafiltration and intradialytic urea generation on the delivered dose of hemodialysis: mURR = [1 - (R/1 + 2*UF/BW) + 0.01*t] x 100% where mURR is modified URR, R is postdialysis plasma urea nitrogen (PUN) to predialysis PUN ratio, UF is ultrafiltrate volume in liters, BW is postdialysis body weight in kilograms, and t is dialysis session length in hours. The equation was validated against 145 hemodialysis treatments on 33 stable maintenance dialysis patients. The mURR values obtained closely predicted single-pool Kt/V (spKt/V) values. In contrast to conventional URR, the range of spKt/V values at each mURR value is narrow over a wide range of UF, t, and R values. Based on the mURR equation, mURR values of 64%, 70%, and 76% are mathematically equivalent to spKt/V levels of 1.0, 1.2, and 1.4, respectively. This equation can be a useful bedside tool to quantify hemodialysis dose.
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96
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Wong KM, Chak WL, Tsang DN, Cheung CY, Chan YH, Choi KS, Lam TW, Chau KF, Li CS. Long-term outcome in hepatitis B sero-positive oriental renal transplant recipients. Transplant Proc 2001; 33:1242-4. [PMID: 11267277 DOI: 10.1016/s0041-1345(00)02405-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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97
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Choi KS, Jun HS, Kim HN, Park HJ, Eom YW, Noh HL, Kwon H, Kim HM, Yoon JW. Role of Hck in the pathogenesis of encephalomyocarditis virus-induced diabetes in mice. J Virol 2001; 75:1949-57. [PMID: 11160694 PMCID: PMC115141 DOI: 10.1128/jvi.75.4.1949-1957.2001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Soluble mediators such as interleukin-1beta, tumor necrosis factor alpha (TNF-alpha), and inducible nitric oxide synthase (iNOS) produced from activated macrophages play an important role in the destruction of pancreatic beta cells in mice infected with a low dose of the D variant of encephalomyocarditis (EMC-D) virus. The tyrosine kinase signaling pathway was shown to be involved in EMC-D virus-induced activation of macrophages. This investigation was initiated to determine whether the Src family of kinases plays a role in the activation of macrophages, subsequently resulting in the destruction of beta cells, in mice infected with a low dose of EMC-D virus. We examined the activation of p59/p56(Hck), p55(Fgr), and p56/p53(Lyn) in macrophages from DBA/2 mice infected with the virus. We found that p59/p56(Hck) showed a marked increase in both autophosphorylation and kinase activity at 48 h after infection, whereas p55(Fgr) and p56/p53(Lyn) did not. The p59/p56(Hck) activity was closely correlated with the tyrosine phosphorylation level of Vav. Treatment of EMC-D virus-infected mice with the Src kinase inhibitor, PP2, resulted in the inhibition of p59/p56(Hck) activity and almost complete inhibition of the production of TNF-alpha and iNOS in macrophages and the subsequent prevention of diabetes in mice. On the basis of these observations, we conclude that the Src kinase, p59/p56(Hck), plays an important role in the activation of macrophages and the subsequent production of TNF-alpha and nitric oxide, leading to the destruction of pancreatic beta cells, which results in the development of diabetes in mice infected with a low dose of EMC-D virus.
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98
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Ko JH, Choi KS, Woo HJ, Lee HI, Kim CW. Evaluation of pH inhibition effect on activated sludge by the pseudo toxic concentration (CPT) concept model. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2001; 43:65-72. [PMID: 11385876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
It is generally accepted that the inhibition effect of pH on activated sludge follows the non-competitive inhibition kinetics. But the non-competitive inhibition kinetic equation cannot be directly applied to pH inhibition, due to the difficulty in quantification of pH as a term of inhibitor concentration. So, many empirical equations were developed especially for acidic condition to describe pH inhibition effect. In this research, the pseudo toxic concentration (CPT) concept model to quantify pH inhibition effect on activated sludge was proposed and compared with other existed models. Prediction of performance, presented by Prediction Accuracy and Prediction Accuracy Index, showed that the CPT concept model can explain the reduction of the maximum specific growth rate (mu max) more accurately than any other models do at a wide range of pH. The CPT concept model was applicable not only to activated sludge but also to specific microorganism groups, such as nitrifier, less acidophilic species and nitrifying biofilm.
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Choi KS, Kanatzidis MG. Si extraction from silica in a basic polychalcogenide flux. Stabilization of Ba4SiSb2Se11, a novel mixed selenosilicate/selenoantimonate with a polar structure. Inorg Chem 2001; 40:101-4. [PMID: 11195365 DOI: 10.1021/ic0007557] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An unusual compound, Ba4SiSb2Se11, was discovered from a reaction of Ba/Th/Sb/Se. It is assumed that Si was extracted from the silica reaction tube. It forms as silver needlelike crystals in the polar space group Cmc2(1) with a = 9.3981(3) A, b = 25.7192(7) A, c = 8.7748(3) A, and Z = 4. A rational synthesis has been devised at 600 degrees C. The compound is composed of Ba2+ ions stabilized between infinite one-dimensional [SiSb2Se11]8- chains running parallel to the a axis. Each chain is composed of a [SbSe2]- infinity backbone with [SiSe4]4- tetrahedra chelating every other Sb atom from the same side of the backbone. The V-shaped triselenide groups, (Se3)2-, are attached to the rest of the Sb atoms in the chain through one of their terminal Se atoms. The compound has a band gap of 1.43 eV. The Raman spectrum shows a broad shift at 247 cm-1 and a shoulder around 234 cm-1, which are related to the Se-Se vibration of the triselenide groups and/or the Si-Se vibrations of the [SiSe4]4- groups. The compound decomposes at 522 degrees C.
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100
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Chon SJ, Kong ES, Kim GB, Kim NC, Kim CH, Kim CK, Kim HK, Ro YJ, Shin KR, Song MS, Ahn SY, Lee KJ, Lee YW, Cho NO, Cho MO, Choi KS. A Study of Gerontological Nursing Curriculum. J Korean Acad Nurs 2001. [DOI: 10.4040/jkan.2001.31.5.808] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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