676
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Chen F, Lam WM, Lin CJ, Qiu GX, Wu ZH, Luk KDK, Lu WW. Biocompatibility of electrophoretical deposition of nanostructured hydroxyapatite coating on roughen titanium surface:In vitroevaluation using mesenchymal stem cells. J Biomed Mater Res B Appl Biomater 2007; 82:183-91. [PMID: 17106895 DOI: 10.1002/jbm.b.30720] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A nano hydroxyapatite (HAp) layer was coated on a roughen titanium surface by means of electrophoretic deposition with an acetic anhydride solvent system. The objectives of this current study are to investigate whether nano-HAp can improve mechanical strength at a lower sintering temperature and biocompatibility. Densification temperature was lowered from usual 1000 to 800 degrees C. The coating interfacial bonding strength, phase purity, microstructure, and biocompatibility were investigated. Degradation of HA phase was not detected in XRD. A porous TiO2 layer acts as a gradient coating layer with an intermediate thermal expansion coefficient between hydroxyapatite and titanium that reduces the thermal stress. From SEM image, the coating does not contain any crack. Mesenchymal stem cell (MSC) is the progenitor cell for various tissues in mature animals, which can improve integration of bone tissue into implant. In this in vitro study, rabbit MSCs culture indicated that the HAp/Ti nanocomposite biomaterial had good biocompatibility and bioactivity. Around materials and on its surface cell grew well with good morphology. Proliferation of the MSCs on the nano-HAp coating was higher than its micron counterpart in XTT assay. These properties show potential for the orthopaedic and dental applications.
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677
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Noginova N, Chen F, Weaver T, Giannelis EP, Bourlinos AB, Atsarkin VA. Magnetic resonance in nanoparticles: between ferro- and paramagnetism. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2007; 19:246208. [PMID: 21694052 DOI: 10.1088/0953-8984/19/24/246208] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Magnetic nanoparticles of γ-Fe(2)O(3) coated with organic molecules and suspended in liquid and solid matrices, as well as non-diluted magnetic fluid, have been studied by electron magnetic resonance (EMR) at 77-380 K. Slightly asymmetric spectra observed at room temperature become much broader and symmetric, and shift to lower fields upon cooling. An additional narrow spectral component (with a line-width of 30 G) is found in diluted samples; its magnitude obeys the Arrhenius law with an activation temperature of about 850 K. The longitudinal spin-relaxation time, T(1)≈10 ns, is determined by a specially developed modulation method. The angular dependence of the EMR signal position in field-freezing samples points to substantial alignment, suggesting the formation of dipolar-coupled aggregates. The shift and broadening of the spectrum upon cooling are assigned to the effect of the surface-related anisotropy. To describe the overall spectral shape, the 'quantization' model is used which includes summation of resonance transitions over the whole energy spectrum of a nanoparticle considered as a giant exchange cluster. This approach, supplemented with some phenomenological assumptions, provides satisfactory agreement with the experimental data.
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678
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Yuan Y, Chen F, Zhao GH, Liu J, Zhang HX, Hu XS. A Comparative Study of Acrylamide Formation Induced by Microwave and Conventional Heating Methods. J Food Sci 2007; 72:C212-6. [DOI: 10.1111/j.1750-3841.2007.00332.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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679
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Gett RM, Gyorki D, Keck J, Chen F, Johnston M. CR09 MANAGING FAECAL INCONTINENCE: THE ROLE OF PTQ INJECTIONS. ANZ J Surg 2007. [DOI: 10.1111/j.1445-2197.2007.04116_9.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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680
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Chen F, Klimchitskaya GL, Mostepanenko VM, Mohideen U. Demonstration of optically modulated dispersion forces. OPTICS EXPRESS 2007; 15:4823-4829. [PMID: 19532728 DOI: 10.1364/oe.15.004823] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report the first experiment on the optical modulation of dispersion forces through a change of the carrier density in a Si membrane. For this purpose a high-vacuum based atomic force microscope and excitation light pulses from an Ar laser are used. The experimental results are compared with two theoretical models. The modulation of the dispersion force will find applications in optomechanical micromachines.
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681
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Chen F, Lee C, Teoh S. Nanofibrous modification on ultra-thin poly(e-caprolactone) membrane via electrospinning. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2007. [DOI: 10.1016/j.msec.2006.05.004] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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682
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Chen F, Bando T, Fukuse T, Omasa M, Aoyama A, Hamakawa H, Fujinaga T, Shoji T, Sakai H, Hanaoka N, Wada H. Recurrent lymphangioleiomyomatosis after living-donor lobar lung transplantation. Transplant Proc 2007; 38:3151-3. [PMID: 17112924 DOI: 10.1016/j.transproceed.2006.08.145] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Indexed: 01/04/2023]
Abstract
Living-donor lobar lung transplantation (LDLLT) has been applied to patients with various end-stage lung diseases. The recurrence of pulmonary lymphangioleiomyomatosis (LAM) after lung transplantation has been rarely reported. Herein, we report a case of recurrent pulmonary LAM after LDLLT. A 24-year-old woman presented with pneumothorax and infiltrates in the left lung 1 year after bilateral LDLLT for LAM. These symptoms and radiologic findings occurred repeatedly and then improved quickly. Thereafter, computed tomography of the chest revealed a tiny emphysematous change of the subpleural region in the left lung, which was exacerbated gradually and was finally diagnosed as LAM recurrence by transbronchial lung biopsy. In previous reports of LAM recurrence, the diagnosis was made at the time of autopsy. This is also the first reported case diagnosed early, that is, when the patient was alive and her allograft had not deteriorated badly.
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683
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Chen F, Mohideen U, Klimchitskaya GL, Mostepanenko VM. Comment on "Lateral Casimir force beyond the proximity-force approximation". PHYSICAL REVIEW LETTERS 2007; 98:068901; author reply 068902. [PMID: 17358989 DOI: 10.1103/physrevlett.98.068901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Indexed: 05/14/2023]
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684
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Chen F, Zhang Y. An Efficient Algorithm to Reconstruct Heart Rate Signal Based on an IPFM Model for the Spectral Analysis of HRV. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2006:936-9. [PMID: 17282338 DOI: 10.1109/iembs.2005.1616569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This paper introduces an efficient algorithm to reconstruct heart rate signal based on an integral pulse frequency modulation (IPFM) model. The heart rate signal was reconstructed by the summation of a set of sinc functions with different weights, whose value could be determined from the IPFM process. Simulation study demonstrated that the signal reconstructed by the proposed method would preserve high frequency component with less distortion than the popular derivative of cubic spline interpolation (DCSI) method. When applied to the spectral analysis of heart rate variability (HRV) of simulated heart rate signal, the proposed method achieved smaller bias than the DCSI method. Therefore, the proposed method would be beneficial for the reconstruction of heart rate signal and the relevant spectral analysis of HRV in the future.
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685
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Chun SY, Chen F, Washburn JG, MacDonald JW, Innes KL, Zhao R, Cruz-Correa MR, Dang LH, Dang DT. CDX2 promotes anchorage-independent growth by transcriptional repression of IGFBP-3. Oncogene 2007; 26:4725-9. [PMID: 17297462 DOI: 10.1038/sj.onc.1210258] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
CDX2 is a Drosophila caudal-related homeobox transcription factor that is important for the establishment and maintenance of intestinal epithelial cells. We have reported that CDX2 promotes tumorigenicity in a subset of human colorectal cancer cell lines. Here, we present evidence that CDX2 negatively regulates the well-documented growth inhibitor insulin-like growth factor binding protein-3 (IGFBP-3). Specifically, CDX2 binds to the IGFBP-3 gene promoter and can repress IGFBP-3 transcription, protein expression and secretion. Furthermore, inhibition of IGFBP-3 partially rescues the decreased anchorage-independent growth phenotype observed in CDX2 knockout cells. These data demonstrate for the first time that (1) CDX2 can function as a transcriptional repressor, and (2) one mechanism by which CDX2 promotes anchorage-independent growth is by transcriptional repression of IGFBP-3.
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686
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Chen F, Lu JC, Xu HR, Huang YF, Lu NQ. Preliminary investigations on the standardisation and quality control for the determination of ?-glutamyltranspeptidase activity in seminal plasma. Andrologia 2007; 39:1-6. [PMID: 17212802 DOI: 10.1111/j.1439-0272.2006.00749.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The present study was designed to assess the effects of centrifugation velocity, standing time after dilution, freezing-thawing and chymotrypsin on the determination of gamma-glutamyltranspeptidase (gamma-GT) activities in seminal plasma, and to establish an instruction for the standardisation and quality control for the determination of gamma-GT within the same laboratory and among different laboratories. The gamma-GT level and sperm concentration of each of 72 samples of seminal plasma obtained by centrifugation at 1000 g for 10 min or 3000 g for 15 min were assayed. In addition, gamma-GT activities in diluted seminal plasma with different standing time and in samples with or without chymotrypsin were measured. The results showed that there was a significant difference of gamma-GT levels in seminal plasma obtained by centrifugation at different velocities (P < 0.001), and that gamma-GT activities in seminal plasma measured after standing for 30 min after dilution were notably lower than those measured immediately after dilution (P < 0.001). However, the data indicated that both chymotrypsin and freezing-thawing had no apparent effect on the determination of seminal gamma-GT. In conclusion, standing time after dilution and centrifugation velocity should be standardised, and frozen seminal plasma could serve as quality control products for the determination of gamma-GT activity among different laboratories.
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687
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Aoyama A, Chen F, Nakamura T, Fujinaga T, Zhang J, Okamoto T, Satoda N, Takahashi A, Hamakawa H, Kondo N, Shoji T, Sakai H, Wada H, Bando T. 558: Human atrial natriuretic peptide ameliorates warm ischemia-reperfusion injury of the lung. J Heart Lung Transplant 2007. [DOI: 10.1016/j.healun.2006.11.583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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688
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Lü B, Chen F, Gong ZH, Xie H, Zhang JH, Liang JS. Intracellular localization of integrin-like protein and its roles in osmotic stress-induced abscisic acid biosynthesis in Zea mays. PROTOPLASMA 2007; 232:35-43. [PMID: 18094925 DOI: 10.1007/s00709-007-0278-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2007] [Accepted: 05/29/2007] [Indexed: 05/20/2023]
Abstract
Plants have evolved many mechanisms to cope with adverse environmental stresses. Abscisic acid (ABA) accumulates significantly in plant cells in response to drought conditions, and this is believed to be a major mechanism through which plants enhance drought tolerance. In this study, we explore the possible mechanisms of osmotic stress perception by plant cells and the consequent induction of ABA biosynthesis. Immunoblotting and immunofluorescence localization experiments, using a polyclonal antibody against human integrin beta1, revealed the presence of a protein in Zea mays roots that is similar to the integrin proteins of animals and mainly localized in the plasma membrane. Treatment with GRGDS, a synthetic pentapeptide containing an RGD domain, which interacted specifically with the integrin protein and thus blocked the cell wall-plasma membrane interaction, significantly inhibited osmotic stress-induced ABA biosynthesis in cells, and the GRGDS analog which does not contain the RGD domain had no effect. Our results show that a strong interaction exists between the cell wall and plasma membrane and that this interaction is largely mediated by integrin-like proteins. They also imply that the cell wall and/or cell wall-plasma membrane interaction plays important roles in the perception of osmotic stress. Accordingly, we conclude that the cell wall and/or cell wall-plasma membrane interaction mediated by the integrin-like protein plays important roles in osmotic stress-induced ABA biosynthesis in Zea mays.
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689
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Lu JC, Xu HR, Chen F, Huang YF, Lu NQ. Standardization and quality control for the determination of alpha-glucosidase in seminal plasma. ACTA ACUST UNITED AC 2006; 52:447-53. [PMID: 17050326 DOI: 10.1080/01485010600822705] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We attempted to provide an instruction for the standardization of alpha-glucosidase level determination and quality controls within the same laboratory and among different laboratories. Each of 51 semen samples was divided into two aliquots, centrifuging at 1000 g for 10 min or 3000 g for 15 min. The alpha-glucosidase level and sperm concentration of each sample were assayed. The alpha-glucosidase level in seminal plasma obtained at 3000 g for 15 min centrifugation was significantly lower than that at 1000 g for 10 min (p = 0.001). An additional 6 samples of seminal plasma with or without phenylmethylsulfonyl fluoride (PMSF), obtained at 3000 g for 15 min centrifugation, were frozen for 20 days, and each of 6 samples was determined for their alpha-glucosidase levels after thawing every other day. There was no significant difference between alpha-glucosidase levels in seminal plasma regardless of the presence of PMSF. The alpha-glucosidase level increased with the length of abstinence period. In conclusion, centrifugal velocity and abstinence time should be standardized in the alpha-glucosidase determination. Frozen seminal plasma may serve as the sample for quality control among clinical laboratories.
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690
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Xu HR, Lu JC, Chen F, Huang YF, Yao B, Lu NQ. The effect of chymotrypsin on the determination of total alpha-glucosidase activity in seminal plasma and the correlation between alpha-glucosidase level and semen parameters. ACTA ACUST UNITED AC 2006; 52:441-6. [PMID: 17050325 DOI: 10.1080/01485010600822689] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
To evaluate the effect of chymotrypsin on the examination of alpha-glucosidase activity in seminal plasma, thirty-nine samples of fresh liquefied semen with or without chymotrypsin and forty-eight samples of fresh un-liquefied semen with chymotrypsin were determined for the total alpha-glucosidase activity in seminal plasma. The total alpha-glucosidase level of each sample was assayed by the method of glucose oxidase. The correlations between alpha-glucosidase level and semen parameters, including semen volume, pH, sperm concentration, grade a and b motility and total motility, were analyzed with SPSS 11.0 software. The results showed that chymotrypsin had no effect on seminal alpha-glucosidase activity determination. Chymotrypsin could improve the liquefaction for un-liquefied semen, and there was no significant difference of alpha-glucosidase activity between liquefied and un-liquefied semen samples. There were significantly positive correlations between seminal alpha-glucosidase activity (U/ml) and sperm concentration (r = 0.338, p = 0.015) and between total alpha-glucosidase activity (U/ejaculate) and semen volume (r = 0.677, p = 0.000). However, there was no significant correlation between alpha-glucosidase level (U/ml) and semen volume, pH, sperm motility or grade a and b motility (r = -0.234 approximately 0.077, p = 0.099 approximately 0.993). The data indicated that chymotrypsin could be added into the un-liquefied semen samples for alpha-glucosidase activity determination, and there were different correlations between seminal alpha-glucosidase level and various semen parameters.
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691
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Chen F, Klimchitskaya GL, Mostepanenko VM, Mohideen U. Demonstration of the difference in the Casimir force for samples with different charge-carrier densities. PHYSICAL REVIEW LETTERS 2006; 97:170402. [PMID: 17155446 DOI: 10.1103/physrevlett.97.170402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Indexed: 05/12/2023]
Abstract
A measurement of the Casimir force between a gold coated sphere and two Si plates of different carrier densities is performed using a high vacuum based atomic force microscope. The results are compared with the Lifshitz theory and good agreement is found. Our experiment demonstrates that by changing the carrier density of the semiconductor plate by several orders of magnitude it is possible to modify the Casimir interaction. This result may find applications in nanotechnology.
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692
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Lee J, Chen F, Steel M, Keck J, Mackay J. Perforated rectal cancer associated with neoadjuvant radiotherapy: report of four cases. Dis Colon Rectum 2006; 49:1629-32. [PMID: 17039387 DOI: 10.1007/s10350-006-0687-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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693
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Chen F, He G, Chen G. Realization of Boolean Functions via CNN: Mathematical Theory, LSBF and Template Design. ACTA ACUST UNITED AC 2006. [DOI: 10.1109/tcsi.2006.883845] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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694
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Tan JY, Zhao N, Wu TX, Yang KH, Zhang JD, Tian JH, Liu YL, Wang KJ, Chen F, Li SF, Li YP. Steroid Withdrawal Increases Risk of Acute Rejection but Reduces Infection: A Meta-Analysis of 1681 Cases in Renal Transplantation. Transplant Proc 2006; 38:2054-6. [PMID: 16979997 DOI: 10.1016/j.transproceed.2006.06.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To evaluate the safety of steroid withdrawal in renal transplantation recipients. METHODS These following databases were searched: Medline (1966 to September 2005), OVID (1966 to 2004), Embase (1984 to 2004), Cochrane library (issue 4, 2005), Highwire (1849 to September 2005), American Transplant Congress (2005), Chinese Biomedicine database (CBM 1994 to 2005). The safety was measured by the following factors: patient and graft survival, acute rejection, chronic rejection, infection, serum creatinine. We performed meta-analysis by using Revman 4.2.7. RESULTS Nine randomized clinical trials were identified to have a steroid withdrawal and a steroid continuing group. They included 1681 patients: 845 with steroid withdrawal and 836 with continuing steroid. The risk of acute rejection after steroid withdrawal was two times higher than steroid-continuing group (RR 2.05; 95% confidence interval [CI]: 1.54, 2.72; P < .00001), while the incidence of opportunistic infection and urinary tract infection of steroid withdrawal group were lower than the control group (RR 0.80; 95%CI 0.64, 1.00; P = .05 vs RR 0.74; 95%CI, 0.60, 0.92; P = .004, respectively). The graft and patient survivals, chronic rejection, and serum creatinine were similar to the steroid continuing group. CONCLUSION Steroid withdrawal can significantly increase the risk of acute rejection episodes, but reduces the incidence of infection to a certain extent. To prophylaxis against serious infection, steroid withdrawal is worth considering using a sufficient immunosuppressive regimen. The key point is to balance the benefit and harm for the individual recipient.
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695
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Kong Q, He GQ, Chen F, Ruan H. Studies on a kinetic model for butyric acid bioproduction by Clostridium butyricum. Lett Appl Microbiol 2006; 43:71-7. [PMID: 16834724 DOI: 10.1111/j.1472-765x.2006.01902.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AIMS This paper discusses the establishment of a kinetic model for cell growth, butyric acid production and substrate consumption of Clostridium butyricum ZJUCB in batch cultivation. METHODS AND RESULTS Mathematic simulations were proposed by the logistic equation for the cell growth, the Luedeking-Piret equation for butyric acid production and the Luedeking-Piret-like equation for glucose consumption. CONCLUSION We compared the performance of our model against that obtained by the empirically experimental design. The experiment-validated model was found suitable for studying butyric acid fermentation kinetics in a complex dynamic behaviour of C. butyricum, especially for its singular growth phenomenon. SIGNIFICANCE AND IMPACT OF THE STUDY The model parameters are estimated from the data fitting and evaluated for simulation of the time courses of the concentrations of cell biomass, butyric acid and glucose and the model appears to fit the experimental data well. The results may be useful for butyric acid production by microbial fermentation.
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696
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Chen F, Bhatia D, Chang Q, Castranova V. Finding NEMO by K63-linked polyubiquitin chain. Cell Death Differ 2006; 13:1835-8. [PMID: 16858426 DOI: 10.1038/sj.cdd.4402014] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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697
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Dang LH, Chen F, Knock SA, Huang EH, Feng J, Appelman HD, Dang DT. CDX2 does not suppress tumorigenicity in the human gastric cancer cell line MKN45. Oncogene 2006; 25:2048-59. [PMID: 16331267 DOI: 10.1038/sj.onc.1209243] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
CDX2 is a Drosophila caudal-related homeobox transcription factor that is expressed specifically in the intestine. In mice, ectopic expression of CDX2 in the gastric mucosa gives rise to intestinal metaplasia and in one model, gastric carcinoma. In humans, increased CDX2 expression is associated with gastric intestinal metaplasia and tubular adenocarcinomas. These patterns of expression have shown that CDX2 is important for the initiation of intestinal metaplasia in the gastric mucosa, but the role of CDX2 in established gastric cancer remains unclear. We sought to determine whether CDX2 contributes to tumorigenic potential in established gastric cancer. The CDX2 gene in MKN45 gastric carcinoma cells was disrupted using targeted homologous recombination. The resulting CDX2-/- cells are essentially identical to their parental cells, with the exception of CDX2 ablation. We found no significant differences in the proliferation of CDX2-/- cells compared to CDX2+/+ cells, in vitro or in vivo. Molecular analyses show that loss of CDX2 predominantly altered the expression of genes involved in intestinal glandular differentiation and adhesion. However, there were no microscopic differences in tumor differentiation. We conclude that disruption of CDX2 in MKN45 cells does not significantly affect their tumorigenic potential.
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698
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Chen F, Mohideen U. Recent experimental advances in precision Casimir force measurements with the atomic force microscope. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/0305-4470/39/21/s14] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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699
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Dang LH, Chen F, Ying C, Chun SY, Knock SA, Appelman HD, Dang DT. CDX2 has tumorigenic potential in the human colon cancer cell lines LOVO and SW48. Oncogene 2006; 25:2264-72. [PMID: 16314840 DOI: 10.1038/sj.onc.1209247] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
CDX2 is a Drosophila caudal-related homeobox transcription factor that is important for the establishment and maintenance of intestinal epithelial cells. CDX2 is a marker of colon cancer, with strong staining in up to 90% of colonic adenocarcinomas. CDX2 heterozygous-null mice develop colonic neoplasms, which have suggested that CDX2 is a tumor suppressor. However, CDX2 has not been reported to affect xenograft growth. Furthermore, CDX2 is rarely mutated in colon cancer, which has led to suggestions that it may play only a minor role as a tumor suppressor in colon cancer. To understand the functional contributions of CDX2 to colon cancer, we disrupted CDX2 in LOVO and SW48 human colon cancer cell lines by targeted homologous recombination. Consistent with the literature, disruption of CDX2 enhanced anchorage-dependent cell proliferation. However, homozygous loss of CDX2 led to significant inhibition of anchorage-independent growth in LOVO cells, and cell lethality in SW48 cells. Further analyses revealed that disruption of CDX2 led to anchorage-independent G1 to S growth arrest and anoikis. In vivo xenograft studies confirmed that disruption of CDX2 inhibited LOVO tumor growth. These data demonstrate that CDX2 mediates anchorage-independent growth and survival. Thus, CDX2 has tumorigenic potential in the human colon cancer cell lines LOVO and SW48.
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700
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Hu ML, Chen F. Crystal structure of bis(2,2'-biimidazol-1-ium) tetrachloroferrate(III) chloride, (C6H7N4)2[FeCl4]Cl. Z KRIST-NEW CRYST ST 2006. [DOI: 10.1524/ncrs.2006.221.14.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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