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Yoo C, Hwang JY, Kim JE, Kim TW, Lee JS, Park DH, Lee SS, Seo DW, Lee SK, Kim MH, Han DJ, Kim SC, Lee JL. A randomised phase II study of modified FOLFIRI.3 vs modified FOLFOX as second-line therapy in patients with gemcitabine-refractory advanced pancreatic cancer. Br J Cancer 2009; 101:1658-63. [PMID: 19826418 PMCID: PMC2778540 DOI: 10.1038/sj.bjc.6605374] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background: Only a few clinical trials have been conducted in patients with advanced pancreatic cancer after failure of first-line gemcitabine-based chemotherapy. Therefore, there is no current consensus on the treatment of these patients. We conducted a randomised phase II study of the modified FOLFIRI.3 (mFOLFIRI.3; a regimen combining 5-fluorouracil (5-FU), folinic acid, and irinotecan) and modified FOLFOX (mFOLFOX; a regimen combining folinic acid, 5-FU, and oxaliplatin) regimens as second-line treatments in patients with gemcitabine-refractory pancreatic cancer. Methods: The primary end point was the 6-month overall survival rate. The mFOlFIRI.3 regimen consisted of irinotecan (70 mg m−2; days 1 and 3), leucovorin (400 mg m−2; day 1), and 5-FU (2000 mg m−2; days 1 and 2) every 2 weeks. The mFOLFOX regimen was composed of oxaliplatin (85 mg m−2; day 1), leucovorin (400 mg m−2; day 1), and 5-FU (2000 mg m−2; days 1 and 2) every 2 weeks. Results: Sixty-one patients were randomised to mFOLFIRI.3 (n=31) or mFOLFOX (n=30) regimen. The six-month survival rates were 27% (95% confidence interval (CI)=13–46%) and 30% (95% CI=15–49%), respectively. The median overall survival periods were 16.6 and 14.9 weeks, respectively. Disease control was achieved in 23% (95% CI=10–42%) and 17% patients (95% CI=6–35%), respectively. The number of patients with at least one grade 3/4 toxicity was identical (11 patients, 38%) in both groups: neutropenia (7 patients under mFOLFIRI.3 regimen vs 6 patients under mFOLFOX regimen), asthaenia (1 vs 4), vomiting (3 in both), diarrhoea (2 vs 0), and mucositis (1 vs 2). Conclusion: Both mFOLFIRI.3 and mFOLFOX regimens were tolerated with manageable toxicity, offering modest activities as second-line treatments for patients with advanced pancreatic cancer, previously treated with gemcitabine.
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Kim JC, Roh SA, Cho DH, Kim TW, Yoon SN, Kim CW, Yu CS, Kim SY, Kim YS. Chemoresponsiveness associated with canonical molecular changes in colorectal adenocarcinomas. Anticancer Res 2009; 29:3115-3123. [PMID: 19661324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
BACKGROUND The canonical molecular changes in colorectal tumorigenesis were assessed for correlation with response to chemotherapy, in order to identify candidate markers. PATIENTS AND METHODS In total, 156 patients received adjuvant postoperative fluoropyrimidine-based chemotherapy and 32 patients received oxaliplatin- or irinotecan-based chemotherapy following palliative surgery or for metastatic or recurrent colorectal tumors. Representative molecular changes in tumor tissues, including adenomatous polyposis coli (APC) gene, wingless-type MMTV integration site family (Wnt), mismatch repair (MMR), RAF, transforming growth factor (TGF)-beta, bone morphogenetic protein, and p53, had been previously determined, with an additional 42 patients included in this analysis. RESULTS The disease-free survival period (mean+/-SEM) was significantly longer after fluoropyrimidine-based adjuvant chemotherapy in tumors with TGF-beta2 expression (42+/-1.4 vs. 21+/-4.7 months; p=0.005) and D18S46 loss of heterozygosity or microsatellite instability (45.7+/-1.5 vs. 40.5+/-1.4 months; p=0.048). In the metastatic settings, the high disease-control rate of oxaliplatin and irinotecan regimens correlated significantly with wild-type APC and intact MMR, respectively, relative to mutant APC and defective MMR (p=0.013, respectively). Interestingly, specific molecular steps of tumorigenensis were closely associated with particular toxicities. CONCLUSION A subset of molecular changes occurring during colorectal tumorigenesis showed significant associations with therapeutic responses and toxicities to chemotherapy regimens, suggesting that these changes may be candidate predictors of chemoresponsiveness with further validation.
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Kim JC, Shin ES, Kim CW, Roh SA, Cho DH, Na YS, Kim TW, Kim MB, Hyun YL, Ro S, Kim SY, Kim YS. In vitro evaluation of histone deacetylase inhibitors as combination agents for colorectal cancer. Anticancer Res 2009; 29:3027-3034. [PMID: 19661311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
BACKGROUND Our primary aim was to evaluate the additive efficacy of histone deacetylase inhibitors (HDACIs) in established treatment regimens for colorectal cancer in concurrence with identifying the clinicopathological markers significantly associated with tumor responsiveness. PATIENTS AND METHODS The chemosensitivities of 125 colorectal carcinomas to established regimens [FLOX (5-FU + leucovorin + oxaliplatin) and FLIRI (5-FU + leucovorin + irinotecan)], two biologically targeted drugs (avastin and erbitux), and two hydroxamic acid derivatives (vorinostat, SAHA(R), and a novel candidate, CG2) were comparatively evaluated using an in vitro tumor response assay. RESULTS The response rates of tumors (inhibition rate > or =30%) were significantly greater for FLOX and combinations (55.2-68%) compared to FLIRI and combinations (44-63.2%) (p=0.001 to 0.048), except in the case of the CG2 combination. The additive effects of HDACIs on the respective established regimens were considerably greater for non-responsive tumors (64.3-80%) than responsive tumors (32.7-45%) (p< or =0.0001 to 0.008). A number of biological parameters, including less advanced tumors and p53 overexpression, were significantly associated with additive chemosensitivity to HDACIs in combination with FLOX and FLIRI in multivariate analyses (p< or =0.001 to 0.023). Expanding tumor growth, diffuse cytoplasmic carcinoembryonic antigen (CEA) expression and synchronous adenoma were associated with combination regimens with targeted drugs (p=0.013 to 0.032). CONCLUSION Our findings show additive chemoresponsiveness of colorectal tumors to HDAC inhibitors in combination with established regimens. The significant parameters associated with combination regimens of targeted drugs and HDACIs may be applied as effective chemosensitive markers in future clinical trials.
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Shin JW, Lee JY, Lee DU, Oh DH, Kim DH, Kim TW, Cho WJ, Jin S. Irradiation-induced shrinkage and expansion mechanisms of SiO2 circle membrane nanopores. NANOTECHNOLOGY 2009; 20:075703. [PMID: 19417431 DOI: 10.1088/0957-4484/20/7/075703] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
20 nm diameter SiO(2) nanopore arrays on gradient-thickness membranes were formed by a focused electron beam with in situ transmission electron microscopy (TEM). Nanopore shrinkage was seen in nanopores on thicker membranes, with the rate of diameter change remaining constant during the shrinkage process. In contrast, pore expansion was observed in thinner membranes, with the expansion rate being constant at the initial stage but with a slight increase at the later stage. The geometry model of shrinkage and expansion of the nanopores in relation to the electron irradiation time was investigated by utilizing the TEM tilting method.
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Lee HS, Rastelli A, Benyoucef M, Ding F, Kim TW, Park HL, Schmidt OG. Microphotoluminescence spectroscopy of single CdTe/ZnTe quantum dots grown on Si001 substrates. NANOTECHNOLOGY 2009; 20:075705. [PMID: 19417433 DOI: 10.1088/0957-4484/20/7/075705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have studied the emission properties of single CdTe/ZnTe quantum dots (QDs) grown on Si(001) substrates by using molecular beam epitaxy and atomic layer epitaxy. The good quality of the QDs is attested by the resolution-limited emission, negligible background and absence of measurable spectral jitter or blinking. Power-dependent, polarization-dependent, and temperature-dependent microphotoluminescence spectroscopy measurements were performed to identify the exciton, the biexciton, and two oppositely charged excitons in the emission spectra of single QDs.
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Kim JC, Kim DD, Lee YM, Kim TW, Cho DH, Kim MB, Ro SG, Kim SY, Kim YS, Lee JS. Evaluation of novel histone deacetylase inhibitors as therapeutic agents for colorectal adenocarcinomas compared to established regimens with the histoculture drug response assay. Int J Colorectal Dis 2009; 24:209-18. [PMID: 18830613 DOI: 10.1007/s00384-008-0590-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/17/2008] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND AIMS This study was to evaluate the efficacy of histone deacetylase (HDAC) inhibitors in colorectal cancer together with other established regimens. MATERIALS AND METHODS Chemosensitivities of 114 colorectal cancer patients to established regimens (fluorouracil (5-FU with leucovorin (FL), capecitabine, FL with irinotecan (FLIRI), and FL with oxaliplatin (FLOX)) as well as five hydroxamic acid derivatives (suberoylanilide hydroxamic acid, PXD101, and three novel candidates of CG-1, CG-2, and CG-3) were comparatively evaluated using the histoculture drug response assay. RESULTS The chemosensitivity with established regimens was between 34.2% and 52.6%, when the cutoff value of the inhibition ratio was set at 30%, and between 54.5% and 84.1% with HDAC inhibitors. All HDAC inhibitors displayed synergistic effects in combination with established regimens of FLOX and FLIRI (P < or = 0.0001-0.002). Advanced T- and N-category tumors and patients with synchronous adenoma displayed higher chemosensitivity to CG-3, CG-2, and CG-1, respectively, on a multivariate analysis (P = 0.023, 0.044, and 0.045, respectively). Tumors with mismatch repair defects were closely correlated with chemosensitivities to combined regimens of PDX101 with FLOX and FLIRI (P = 0.044 and 0.048, respectively). CONCLUSIONS Our findings firstly demonstrated the chemo-responsiveness of colorectal cancers to HDAC inhibitors with therapeutic efficacy comparable to the established regimens. Additionally, tumor growth and heredity were significantly associated with specific regimens, supporting their possible role as chemosensitive predictors.
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Park HM, Kim TW. Extension of the Helmholtz-Smoluchowski velocity to the hydrophobic microchannels with velocity slip. LAB ON A CHIP 2009; 9:291-296. [PMID: 19107287 DOI: 10.1039/b808432g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Electrokinetic flows through hydrophobic microchannels experience velocity slip at the microchannel wall, which affects volumetric flow rate and solute retention time. The usual method of predicting the volumetric flow rate and velocity profile for hydrophobic microchannels is to solve the Navier-Stokes equation and the Poisson-Boltzmann equation for the electric potential with the boundary condition of velocity slip expressed by the Navier slip coefficient, which is computationally demanding and defies analytic solutions. In the present investigation, we have devised a simple method of predicting the velocity profiles and volumetric flow rates of electrokinetic flows by extending the concept of the Helmholtz-Smoluchowski velocity to microchannels with Navier slip. The extended Helmholtz-Smoluchowski velocity is simple to use and yields accurate results as compared to the exact solutions. Employing the extended Helmholtz-Smoluchowski velocity, the analytical expressions for volumetric flow rate and velocity profile for electrokinetic flows through rectangular microchannels with Navier slip have been obtained at high values of zeta potential. The range of validity of the extended Helmholtz-Smoluchowski velocity is also investigated.
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Kim W, Chung SG, Kim TW, Seo KS. Measurement of soft tissue compliance with pressure using ultrasonography. Lymphology 2008; 41:167-177. [PMID: 19306663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Lymphedema is swelling, particularly in the subcutaneous tissues, due to accumulation of lymph. Previous imaging techniques have demonstrated associated structural changes and have been used for evaluating the status of soft tissues. However, the reliability of measurements using ultrasonography has not been evaluated and the ultrasonographic method has been unable to show changes in tissue softness. There is a need to determine if ultrasonography is a reliable technique to assess skin and subcutaneous thickness in the upper extremities with or without pressure and if the measure of compliance in soft tissue thickness is also reliable. Two examiners measured tissue thicknesses using ultrasonography and calculated the compliance with and without pressure on the forearm and upper arm, independently. The intra- and inter-rater cross-correlation coefficients of measuring soft tissue thickness were excellent (> 0.75) in the forearm (p < 0.05). In the upper arm, the reliabilities were fair-to-good. The intraclass correlation coefficients of pressure compliance in the forearm and upper arm were excellent and fair-to-good, respectively (p < 0.05). This study suggests that measurement of thickness of soft tissues using ultrasonography may be reliable and pressure compliance may reflect tissue softness in the upper extremity.
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Shin JW, No YS, Kim TW, Choi WK. Formation and microstructural properties of locally distributed ZnSiO3 nanoparticles embedded in a SiO2 layer by using a focused electron beam. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2008; 8:5566-5570. [PMID: 19198500 DOI: 10.1166/jnn.2008.1349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Locally distributed crystalline ZnSiO3 nanoparticles embedded in a SiO2 layer inserted between the ZnO thin film and the Si substrate were formed using transmission electron microscopy (TEM) with a focused electron beam irradiation process. High-resolution TEM (HRTEM) images and energy dispersive X-ray spectroscopy (EDS) profiles showed that ZnSiO3 nanocrystals with a size of approximately 6 nm were formed in the SiO2 layer. The formation mechanisms of the ZnSiO3 nanocrystals in the SiO2 layer are described on the basis of the HRTEM images and the EDS profiles.
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Yoon J, Choi D, Oh DH, Kim TW, Kim YH. Formation of copper based nanoparticles embedded in a relatively thick polyimide film by thermal curing in reducing atmosphere. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2008; 8:5433-5438. [PMID: 19198471 DOI: 10.1166/jnn.2008.1100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We investigated the formation of nanoparticles in a relatively thick polyimide (PI) film (> 1 microm) in controlled atmospheres and optical properties of these nanoparticles. Polyamic acid of 10 wt% BPDA-PDA was spin-coated on the 25 nm Cu thin film and thermally cured at 350 degrees C in high purity nitrogen or 5% H2 + 95% N2 atmosphere. The fabricated nanoparticles in high purity nitrogen atmosphere had spherical shape and were dispersed in the 1.5 microm thick PI film. Its phase was revealed as Cu and Cuprous Oxide by X-ray diffraction (XRD). Its size and optical absorption depended on deposited metal thin film thickness. After post heat-treatment in 5% H2 + 95% N2 atmosphere, surface plasmon resonance from metallic Cu nanoparticle was enhanced. In the specimens cured in reducing atmosphere, 5% H2 + 95% N2, highly dense and 3.5 nm size nanoparticles were well dispersed in an entire PI film. XRD results and optical data revealed that nanoparticles fabricated in 5% H2 + 95% N2 atmosphere were metallic Cu. Thermal curing in reducing atmosphere produces nanoparticles of high density, and uniform dispersion in a relatively thick PI film.
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Park HM, Kim TW. Recursive estimation of transient inhomogeneous zeta potential in microchannel turns using velocity measurements. Biomed Microdevices 2008; 11:231-41. [PMID: 18807196 DOI: 10.1007/s10544-008-9228-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
In the various biomedical microfluidic devices the target biomolecules are delivered by activating electroosmotic flows. The zeta potential of a microchannel wall, which determines the strength of the electroosmotic flow, is apt to change due to the adhesion of biomolecules such as DNA or protein especially around the microchannel turns. The resulting transient inhomogeneous profile of zeta potential alters flow pattern, volumetric flow rate and the band broading of solutes. In the present work, we have developed a method for the recursive estimation of transient inhomogeneous zeta potential in microchannel turns using velocity measurements. For the real time implementation of the present method, a compact and accurate reduced-order model is derived using the Karhunen-Loève Galerkin method and the Helmholtz-Smoluchowski slip velocity. The present scheme of recursive estimation is an important prerequisite to the real time control of microfluidic devices.
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Shin JW, Lee JY, No YS, Kim TW, Choi WK, Jin S. The formation mechanism of periodic Zn nanocrystal arrays embedded in an amorphous layer by rapid electron beam irradiation. NANOTECHNOLOGY 2008; 19:295303. [PMID: 21730602 DOI: 10.1088/0957-4484/19/29/295303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A periodic nano-island array of ∼7 nm diameter Zn single crystals embedded in an amorphous Zn(2x)Si(1-x)O(2) layer was created by using rapid electron beam irradiation for 50 s. A sequential process of 900 °C thermal annealing followed by electron beam irradiation induces the formation of an amorphous Zn(2x)Si(1-x)O(2) layer containing periodic Zn nanocrystals. It is shown that the periodic Zn crystal array can be produced with good control of their size and spacing. Possible formation mechanisms for the Zn crystal nano-islands are described on the basis of the experimental results.
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Yoon SH, Kumar S, Kim GH, Choi YS, Kim TW, Khondaker SI. Dielectrophoretic assembly of single gold nanoparticle into nanogap electrodes. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2008; 8:3427-3433. [PMID: 19051890 DOI: 10.1166/jnn.2008.129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report the optimization study of assembling single 20 nm gold nano-particle in 20 nm spaced electrode gap via ac dielectrophoresis (DEP) technique. It was observed that time, voltage, and frequency variations influenced significantly the assembly of gold nano-particle in the nano-gap electrodes. Frequency variation study revealed that at lower frequencies (< 1 MHz) the assembling was observed in low field regions; however, at a moderate frequency of 1 MHz, minimum number of nano-particles was assembled in high field region. Trapping of single 20 nm nano-particle in 20 nm spaced electrodes was successfully achieved under the optimized DEP parameters i.e., frequency, applied voltage and time of values corresponding to 1 MHz, 2 V, and 1 sec, respectively, with the yield of almost 66%. Our results show the promise of optimized dielectrophoresis in the future nano-engineering.
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Kim TW, Kim TW, Park KH, Kim DM. An unexpectedly low Stratus optical coherence tomography false-positive rate in the non-nasal quadrants of Asian eyes: indirect evidence of differing retinal nerve fibre layer thickness profiles according to ethnicity. Br J Ophthalmol 2008; 92:735-9. [DOI: 10.1136/bjo.2007.129502] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Kim TW, Palepu A, Cheng DM, Libman H, Saitz R, Samet JH. Factors associated with discontinuation of antiretroviral therapy in HIV-infected patients with alcohol problems. AIDS Care 2008; 19:1039-47. [PMID: 17852002 PMCID: PMC2579777 DOI: 10.1080/09540120701294245] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Although mortality rates among HIV-infected populations have declined with the advent of combination antiretroviral therapy (ART), patients with substance use disorders have benefited less from these therapies. While adherence to ART has been well studied, less is known about factors associated with discontinuation of ART. The aim of this study is to investigate predictors of discontinuation of ART in HIV-infected patients with alcohol problems, focusing on their substance use and depressive symptoms. The study cohort (n=266) was prospectively assessed with biannual standardised interviews between 2001 and 2005. Four predictor variables (cocaine, heroin, heavy alcohol use and substantial depressive symptoms) were assessed six months prior to the outcome (ART discontinuation). Longitudinal logistic regression models examined the association between predictor variables and ART discontinuation adjusting for age, gender, race/ethnicity, homelessness, CD4, HIV RNA and HIV Symptom Index. Subjects were 77% male; 43% black; 22% homeless; 45% used cocaine; 20% used heroin; 29% had heavy alcohol use; and 40% had substantial depressive symptoms. Discontinuation occurred in 135 (17%) of the observations (n=743). In bivariate analyses, cocaine use, heroin use and depressive symptoms were significantly associated with ART discontinuation but heavy alcohol use was not. In the multivariable model, substantial depressive symptoms (adjusted odds ratio (AOR)=1.66; 95% confidence interval (CI): 1.04, 2.65) but not cocaine (AOR=1.28; 95%CI: 0.76, 2.16) or heroin use (AOR=1.27 95%CI: 0.66, 2.44), remained significantly associated with ART discontinuation. Among HIV-infected adults with alcohol problems, depressive symptoms, but not substance use, predicted subsequent ART discontinuation. Recognition and treatment of depressive symptoms in this population may result in better maintenance of ART and its associated clinical benefits.
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Kim TW, Igimi S, Kajikawa A, Kim HY. Display of heterologous proteins on the surface of Lactococcus lactis using the H and W domain of PrtB from Lactobacillus delburueckii subsp. bulgaricus as an anchoring matrix. J Appl Microbiol 2008; 104:1636-43. [PMID: 18298534 DOI: 10.1111/j.1365-2672.2007.03690.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
AIMS The aim of this study was to develop a cell-surface display system for foreign antigens on the surface of a Lactococcus lactis strain using an H and W domain of PrtB from Lactobacillus delburueckii subsp. bulgaricus as an anchoring matrix. METHODS AND RESULTS To construct a cell-surface display pACL1 vector, a derivative of pSECE1 vector, we amplified the H and W domain of the cell-surface proteinase Prt B from Lact. bulgaricus using specific primers and then cloned it into a site downstream of the secretion signal sequence in the pSECE1 vector. The new system, designed for cell-surface display of recombinant proteins on L. lactis, was evaluated by the expression and display of the FliC protein of Salmonella enterica serovar Enteritidis as a reporter gene (pALC1:FliC). The expression of the FliC protein by the transformed cells was analysed by Western blot analysis, and the localization of FliC on the cell surface was confirmed by immunofluorescence microscopy and flow cytometry analysis. A specific band corresponding in size (approx. 110 kDa) to FliC plus the anchor residues was detected by anti-FliC antibody in the cell extract of L. lactis H61 harbouring pALC1:FliC, but not L. lactis H61 harbouring pALC1. In addition, flow cytometry and immunofluorescence microscopy revealed FliC-specific positive signals and a significant increase of fluorescence, respectively, in cells harbouring pALC1:FliC compared with that in control cells harbouring the parental pALC1 plasmid. These findings demonstrated that FliC was successfully displayed on the cell surface by the anchor domain of PrtB. CONCLUSIONS A pALC1 vector using the H and W domain of PrtB from Lact. bulgaricus as an anchoring matrix can be used to successfully display the FliC protein on the surface of L. lactis. SIGNIFICANCE AND IMPACT OF THE STUDY This novel way of displaying heterologous proteins on the cell surface of L. lactis using the PrtB anchor domain should prove useful for the delivery of antigens and other proteins.
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Park BS, Son DJ, Park YH, Kim TW, Lee SE. Antiplatelet effects of acidamides isolated from the fruits of Piper longum L. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2007; 14:853-5. [PMID: 17689230 DOI: 10.1016/j.phymed.2007.06.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Revised: 04/04/2007] [Accepted: 05/10/2007] [Indexed: 05/16/2023]
Abstract
The inhibitory effects of four acidamides, piperine, pipernonaline, piperoctadecalidine, and piperlongumine, isolated from the fruits of Piper longum L. on washed rabbit platelet aggregation were examined. All of the four tested acidamides showed dose-dependent inhibitory activities on washed rabbit platelet aggregation induced by collagen, arachidonic acid (AA), and platelet-activating factor (PAF), except for that induced by thrombin. Piperlongumine, in particular, showed stronger inhibitory effects than other acidamides to rabbit platelet aggregation induced by collagen, AA and PAF.
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Park HM, Lee JS, Kim TW. Comparison of the Nernst–Planck model and the Poisson–Boltzmann model for electroosmotic flows in microchannels. J Colloid Interface Sci 2007; 315:731-9. [PMID: 17681522 DOI: 10.1016/j.jcis.2007.07.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 06/12/2007] [Accepted: 07/03/2007] [Indexed: 11/21/2022]
Abstract
In the analysis of electroosmotic flows, the internal electric potential is usually modeled by the Poisson-Boltzmann equation. The Poisson-Boltzmann equation is derived from the assumption of thermodynamic equilibrium where the ionic distributions are not affected by fluid flows. Although this is a reasonable assumption for steady electroosmotic flows through straight microchannels, there are some important cases where convective transport of ions has nontrivial effects. In these cases, it is necessary to adopt the Nernst-Planck equation instead of the Poisson-Boltzmann equation to model the internal electric field. In the present work, the predictions of the Nernst-Planck equation are compared with those of the Poisson-Boltzmann equation for electroosmotic flows in various microchannels where the convective transport of ions is not negligible.
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Ryu MH, Kang YK, Jang SJ, Kim TW, Lee H, Kim JS, Park YH, Lee SS, Ryoo BY, Chang HM, Lee JL, Yook JH, Kim BS, Lee JS. Prognostic significance of p53 gene mutations and protein overexpression in localized gastrointestinal stromal tumours. Histopathology 2007; 51:379-89. [PMID: 17727479 DOI: 10.1111/j.1365-2559.2007.02797.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
AIMS Mutation of c-kit is a relatively early event in the tumorigenesis of gastrointestinal stromal tumours (GISTs). The aim was to determine the prognostic significance of p53 alterations as an additional genetic change in GISTs. METHODS AND RESULTS We reviewed 125 patients with localized GISTs subjected to complete resection between 1990 and 2002. Mutational analyses of c-kit exons 9, 11, 13 and 17, p53 exons 4-8 and immunohistochemistry for p53 protein were conducted using paraffin-embedded tissues. Alterations of p53 were observed in 50 patients (40.0%). Based on the National Institutes of Health's risk category, p53 alterations were noted more frequently in the higher risk categories (P = 0.041). With a median follow-up of 56.5 months (range: 2.3-126.8), 5-year relapse-free survival (RFS) rates were 61.7% without p53 alterations, compared with only 40.2% with p53 alterations (P = 0.009). Multivariate analysis indicated that p53 alterations comprised an independent, poor prognostic factor for RFS, in addition to c-kit mutations, large size, a high mitotic count and non-gastric primary sites. CONCLUSIONS Alterations in p53 were more commonly observed in localized GISTs at higher risk of relapse. This suggests that they are significant as an independent, poor prognostic factor.
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Kim TW, Lei XG. An improved method for a rapid determination of phytase activity in animal feed. J Anim Sci 2007; 83:1062-7. [PMID: 15827251 DOI: 10.2527/2005.8351062x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The current direct colorimetric assay for phytase activity in feeds has interference from high P background and other factors. Our objective was to develop a rapid and reliable spin column method to accurately determine phytase activity in feed ingredients or complete diets. After the feed sample was extracted by stirring in 0.2 M citrate buffer, pH 5.5, for 30 min at room temperature, the oily layer of the supernatant fraction was removed by passing through an acrodisc syringe filter (0.45-microm HT Tuffryn membrane, Gelman Laboratory, Ann Arbor, MI). The filtrate was then loaded onto a spin column (MW cutoff 30,000, Millipore, Bedford, MA) to remove free phosphate before the phytase activity assay. Compared with the direct assay, this new procedure improved both accuracy and reproducibility. When diets contained phytase at 0 to 1,500 U/kg (as fed), the CV for multiple assays of the same samples (n = 6) by the new method ranged from 1 to 6% compared with 28 to 39% by the direct method. A linear relationship was found between the added phytase activity in practical diets and the analyzed activity by the new method (r2 = 0.99; P < 0.01). In conclusion, the spin column method is an improved assay for phytase activity in animal feed, and may be used for quality control of phytase supplementation.
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Koo DH, Chang HM, Jung JY, Song JH, Lee JL, Ryu MH, Kim TW, Yook JH, Song JS, Lee JS, Kang YK. Cutaneous metastasis resembling acute dermatitis in patient with advanced gastric cancer. Clin Exp Dermatol 2007; 32:284-6. [PMID: 17263831 DOI: 10.1111/j.1365-2230.2007.02361.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The most common metastatic sites from gastric cancer are the liver, intra-abdominal lymph nodes, ovary and peritoneal cavity. Cutaneous metastasis of gastric cancer is rare, and most cutaneous metastases are typically solitary, nodular, have a firm consistency, and are red or hyperpigmented. Thus, cutaneous metastasis is easily distinguished from other skin disease. We report a case of a 60-year-old woman with cutaneous metastasis of gastric cancer, whose facial skin showed painless pruritic eczema, resembling acute dermatitis. She had earlier undergone a total gastrectomy for advanced gastric cancer in our hospital. After 14 months, she developed eczematous facial lesions; the presumptive diagnosis was acute dermatitis. However, skin biopsy unexpectedly revealed cutaneous metastasis of gastric cancer. After 6 months of systemic chemotherapy with capecitabine and cisplatin, the cutaneous metastasis was markedly improved and a clinically complete remission was accomplished.
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97
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Park HM, Kim TW. Simultaneous estimation of zeta potential and slip coefficient in hydrophobic microchannels. Anal Chim Acta 2007; 593:171-7. [PMID: 17543604 DOI: 10.1016/j.aca.2007.04.054] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 04/26/2007] [Accepted: 04/27/2007] [Indexed: 11/15/2022]
Abstract
Electroosmotic flows through hydrophobic microchannels experience velocity slip at the channel wall, which increases the volumetric flow rate at a given electric potential gradient. The conventional method of zeta potential estimation using the volumetric flow rate may yield quite inaccurate zeta potential unless the velocity slip is appropriately taken care of. In the present investigation we develop a method for simultaneous estimation of zeta potential and velocity slip coefficient in the electroosmotic flow through a hydrophobic microchannel using velocity measurements. The relevant inverse problem is solved through the minimization of a performance function utilizing a conjugate gradient method. The present method is found to estimate the zeta potential and slip coefficient accurately even with noisy velocity measurements.
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98
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Koo DH, Lee JL, Kim TW, Chang HM, Ryu MH, Yook JH, Oh ST, Kim BS, Lee JS, Kang YK. Adjuvant chemotherapy with 5-fluorouracil, doxorubicin and mitomycin-C (FAM) for 6 months after curative resection of gastric carcinoma. Eur J Surg Oncol 2007; 33:843-8. [PMID: 17207959 DOI: 10.1016/j.ejso.2006.11.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Accepted: 11/28/2006] [Indexed: 11/18/2022] Open
Abstract
AIM This study aimed to evaluate the efficacy and safety of 5-fluorouracil (5-FU), doxorubicin and mitomycin-C (FAM) adjuvant chemotherapy in patients who had undergone curative resection of gastric carcinoma. METHODS From Nov 1999 to Jan 2002, 291 consecutive patients with stage IB-IIIB gastric adenocarcinoma were given FAM adjuvant chemotherapy. Chemotherapy comprised intravenous 5-FU 600 mg/m(2) (days 1, 8, 29 and 36), doxorubicin 30 mg/m(2) (days 1 and 29) and mitomycin-C 10 mg/m(2) (day 1), every 8 weeks for 6 months. RESULTS The median follow-up time was 60.6 months, 92 patients died, and 93 patients had recurrent disease. The 5-year overall survival (OS) rates were 85.9% for stage IB, 72.1% for stage II, 58.0% for stage IIIA, and 48.2% for stage IIIB (p=0.002). The 5-year relapse-free survival (RFS) rates were 85.2% for stage IB, 71.2% for stage II, 53.3% for stage IIIA, and 39.2% for stage IIIB (p<0.001). A total of 769 cycles of chemotherapy were delivered, and 15 patients experienced grade 3 or higher leukopenia. The most common grade 3 or higher non-hematologic toxicity was nausea/vomiting (11 patients), followed by stomatitis (3 patients). CONCLUSIONS Adjuvant chemotherapy with FAM for 6 months for gastric carcinoma indicated comparable RFS and OS with an acceptable toxicity profile.
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Kim TW, Chan CC. Local anesthetic infiltration of the wound for supplemental postoperative pain management in a pediatric liver transplant patient. Paediatr Anaesth 2007; 17:87-8. [PMID: 17184441 DOI: 10.1111/j.1460-9592.2006.01963.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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100
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Kim TW, Bailard N, Coveler LA. The anesthetic management of a child with chronic hypotension for renal transplantation. J Clin Anesth 2006; 18:297-9. [PMID: 16797433 DOI: 10.1016/j.jclinane.2005.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2004] [Accepted: 10/12/2005] [Indexed: 11/22/2022]
Abstract
The anesthetic management of renal transplant recipients requires the maintenance of an adequate perfusion pressure to ensure viability of the donated kidney. A common finding among patients with end-stage renal disease is chronic hypertension. We report a case involving a 2-year-old child with an age-adjusted blood pressure below normal, undergoing transplantation of an adult cadaveric kidney, during which high-dose vasopressor medications were used to sustain the child's blood pressure at above-normal levels to help ensure perfusion of the adult allograft.
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