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Yan G, Chen W. An adaptive markov model-based method to cluster validation in image segmentation. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2005:6301-4. [PMID: 17281708 DOI: 10.1109/iembs.2005.1615938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The number of class should be detected as part of the parameter estimation procedure prior to image segmentation for segmentation algorithms. It is very important in theory and application for estimating the class number correctly. In this paper, an adaptive total energy criterion (ATEC) to cluster validation is proposed based on the Markov random field (MRF) in the image segmentation. The criterion is composed of two parts: one part is inner-energy, which describes the difference of data in the same class; another is inter-class energy, which describes the edge information. The correct class number can be obtained by minimizing the ATEC. The parameters are estimated by expectation maximum (EM) algorithm and maximum psedu-likelihood (MPL) algorithm. The complex computation is optimized by the mixture of simulated algorithm (SA) and iterated conditional mode (ICM). The experiments show that the class number can be automatically detected by adjusting the hyper-parameter in MRF. As a by-product, the segmentation can be obtained by the maximum a posteriori (MAP).
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Cheng LT, Chen W, Tang W, Wang T. Does loss of residual renal function lead to malnutrition in peritoneal dialysis patients? Clin Nephrol 2007; 66:192-201. [PMID: 16995342 DOI: 10.5414/cnp66192] [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] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES It is usually believed that loss of residual renal function is associated with anorexia and the development of malnutrition. We conducted a retrospective study in our center to evaluate the effect of declining residual renal function on patients' nutritional status. METHODS All incident uremic patients (n = 46) who began peritoneal dialysis from January 1, 2003 June 1, 2003 in our center were closely followed for 1 year with focus on maintaining strict volume control with time on dialysis. Patient's residual renal function (RRF) was assessed by the average renal urea and creatinine clearances. Those patients who had more than 50% decrease in GFR were selected for the present analysis. Serum albumin (ALB), dietary protein intake (DPI) and subjective global assessment (SGA) were closely followed. RESULTS There were 16 patients (9 males and 7 females) included in the present analysis, among whom 31.3% were diabetics. Patients' GFR declined significantly (RRF were 4.32 +/- 2.69, 2.99 +/- 2.21 and 1.24 +/- 0.99 ml/min for Months 1, 6 and 12, respectively, p < 0.05), along with a significant decline in urine volume (985.62 +/- 543.29, 698.13 +/- 463.59 and 425.63 +/- 320.52 ml/d for Months 1, 6 and 12, respectively, p < 0.01). Although weekly peritoneal Kt/V did not increase significantly, peritoneal ultrafiltration increased significantly during this period (428.75 +/- 408.96, 534.38 +/- 296.39, 844.38 +/- 440.35 ml for Months 1, 6 and 12, respectively, p < 0.05). Serum ALB increased significantly (32.34 +/- 5.07, 34.74 +/- 4.89 and 36.21 +/- 3.98 g/l for Months 1, 6 and 12, respectively, p < 0.01). DPI also increased significantly. The prevalence of malnutrition (by SGA) decreased from 62.5% at the start of dialysis to 18.8% at the end of this study (p < 0.05). CONCLUSIONS Our study suggests that rapid decline of residual renal function in PD patients does not necessarily lead to decreased dietary protein intake and deteriorated nutritional status. Focus on incremental peritoneal fluid removal along with the decline in residual renal function and, thus, maintaining volume control may be one of the critical reasons for the success.
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Chen W, Jump DB, Esselman WJ, Busik JV. Inhibition of cytokine signaling in human retinal endothelial cells through modification of caveolae/lipid rafts by docosahexaenoic acid. Invest Ophthalmol Vis Sci 2007; 48:18-26. [PMID: 17197511 PMCID: PMC1975816 DOI: 10.1167/iovs.06-0619] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE Docosahexaenoic acid (DHA(22:6,n3)) is the principal n3 polyunsaturated fatty acid (PUFA) in the retina. The authors previously demonstrated that DHA(22:6,n3) inhibited cytokine-induced adhesion molecule expression in primary human retinal vascular endothelial (hRVE) cells, the target tissue affected by diabetic retinopathy. Despite the importance of vascular inflammation in diabetic retinopathy, the mechanisms underlying anti-inflammatory effects of DHA(22:6,n3) in vascular endothelial cells are not understood. In this study the authors address the hypothesis that DHA(22:6,n3) acts through modifying lipid composition of caveolae/lipid rafts, thereby changing the outcome of important signaling events in these specialized plasma membrane microdomains. METHODS hRVE cells were cultured in the presence or absence of DHA(22:6,n3). Isolated caveolae/lipid raft-enriched detergent-resistant membrane domains were prepared using sucrose gradient ultracentrifugation. Fatty acid composition and cholesterol content of caveolae/lipid rafts before and after treatment were measured by HPLC. The expression of Src family kinases was assayed by Western blotting and immunohistochemistry. RESULTS Disruption of the caveolae/lipid raft structure with a cholesterol-depleting agent, methyl-cyclodextrin (MCD), diminished cytokine-induced signaling in hRVE cells. Growth of hRVE cells in media enriched in DHA(22:6,n3) resulted in significant incorporation of DHA(22:6,n3) into the major phospholipids of caveolae/lipid rafts, causing an increase in the unsaturation index in the membrane microdomain. DHA(22:6,n3) enrichment in the caveolae/raft was accompanied by a 70% depletion of cholesterol from caveolae/lipid rafts and displacement of the SFK, Fyn, and c-Yes from caveolae/lipid rafts. Adding water-soluble cholesterol to DHA(22:6,n3)-treated cells replenished cholesterol in caveolae/lipid rafts and reversed the effect of DHA(22:6,n3) on cytokine-induced signaling. CONCLUSIONS Incorporation of DHA(22:6,n3) into fatty acyl chains of phospholipids in caveolae/lipid rafts, followed by cholesterol depletion and displacement of important signaling molecules, provides a potential mechanism for anti-inflammatory effect of DHA(22:6,n3) in hRVE cells.
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Chen W, Sailhamer E, Berger DL, Rattner DW. Operative time is a poor surrogate for the learning curve in laparoscopic colorectal surgery. Surg Endosc 2007; 21:238-43. [PMID: 17180745 DOI: 10.1007/s00464-006-0120-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Accepted: 05/08/2006] [Indexed: 02/03/2023]
Abstract
BACKGROUND Previous studies have relied on conversion rate and operative time for construction of learning curves in laparoscopic colorectal surgery. The authors hypothesized that conversion rate and operative time were less important than complication and readmission rates in defining good outcomes and hence the learning curve. METHODS A database of 287 consecutive laparoscopic colorectal resections from a single tertiary referral center was analyzed. Outcome measures included operative time, conversion rate, major and minor complications, length of hospital stay, and the 15- and 30-day hospital readmission rate. Data were analyzed both by surgeons and by quartile case numbers. RESULTS A total of 151 right colectomies and 136 left colectomies were performed between 1995 and 2005. For both right and left colectomies, the conversion rate decreased in each of the first three quartiles, reaching a nadir of 0% for right colectomies and 3% for left colectomies in the third quartile. The conversion rates increased slightly in the fourth quartile. The operative time remained stable for three quartiles, then increased slightly in the fourth quartile. Two surgeons managed 199 of the 287 cases. Analysis of the two high-volume surgeons demonstrated that for left-sided resections, the surgeon with the shorter operative times had the higher major complication rate (13% vs 2%), overall complication rate (22% vs 2%), 30-day readmission rate (13% vs 0%), and length of stay (3.8 vs 3.1 days) (p < 0.05 for all comparisons). CONCLUSIONS In this series, operative time failed to decrease with experience, and shorter operative times did not correlate with better clinical outcomes. The failure of operative time to decline with experience often reflects surgeons' willingness to attempt more difficult cases rather than an accurate representation of a "learning curve." Therefore, complication and readmission rates are more important than operative time and conversion rates for evaluating the learning curve and quality of laparoscopic colorectal surgery.
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Chen W, Yu YS, Liu YH, Sheen JM, Hsiao CC. Nail changes associated with chemotherapy in children. J Eur Acad Dermatol Venereol 2007; 21:186-90. [PMID: 17243953 DOI: 10.1111/j.1468-3083.2006.01887.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Large series of chemotherapy-induced nail changes in children have rarely been reported in the literature. OBJECTIVE To study the pattern and onset of nail changes in cancer children receiving various chemotherapy regimens. METHODS A cross-sectional study was performed on 30 paediatric patients (aged 1-17, mean 8.3 years), including 11 with acute lymphoblastic leukaemia, five with acute myeloid leukaemia, and others. RESULTS Nail changes developed in 10 children during chemotherapy, five of whom had Muehrcke's lines, three Beau's lines, one Mees' lines and another had trachyonychia. There appeared to be no correlation between the pattern of nail alteration and the underlying cancer types or stages, or the regimens of chemotherapy. CONCLUSION One third of the children with cancers developed nail changes associated with chemotherapy. Among them, Muehrcke's lines were the most common manifestation, which were unrelated to hypoalbuminaemia in our series.
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Jiang D, Huang Q, Cai P, Rong X, Chen W. Adsorption of Pseudomonas putida on clay minerals and iron oxide. Colloids Surf B Biointerfaces 2007; 54:217-21. [PMID: 17142018 DOI: 10.1016/j.colsurfb.2006.10.030] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 10/18/2006] [Accepted: 10/19/2006] [Indexed: 10/24/2022]
Abstract
Adsorption of Pseudomonas putida on minerals including montmorillonite, kaolinite and goethite was studied. The adsorption isotherms of P. putida on the examined minerals conformed to the Langmuir equation. The amount of P. putida adsorbed followed the order: goethite > kaolinite > montmorillonite. A greater extent of P. putida adsorption on minerals was observed in the range of temperature from 15 to 35 degrees C. The adsorption of P. putida on minerals decreased with the increase of pH from 3.0 to 10.0. Magnesium ion was more efficient than sodium ion in promoting P. putida adsorption on minerals. The results suggest that electrostatic interactions play a vital role in P. putida adsorption by soil colloidal factions. The information obtained in this study is of fundamental significance for the understanding of the survival and transport of bacteria in soil systems.
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Lin HY, Chen W, Tsutsumi A. Surrogate Testing for Nonlinear Hydrodynamics in Bubble Columns. Ind Eng Chem Res 2007. [DOI: 10.1021/ie061046p] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Qin F, Chen W. Lead and copper levels in tea samples marketed in Beijing, China. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2007; 78:128-31. [PMID: 17401507 DOI: 10.1007/s00128-007-9052-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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KuoLee R, Zhao X, Austin J, Harris G, Conlan JW, Chen W. Mouse model of oral infection with virulent type A Francisella tularensis. Infect Immun 2007; 75:1651-60. [PMID: 17242058 PMCID: PMC1865681 DOI: 10.1128/iai.01834-06] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Francisella tularensis is a gram-negative facultative intracellular pathogen and the causative agent of tularemia. Little is known about the immunopathogenesis of oral infection with this pathogen. Here, for the first time, we examined the susceptibility of mice to intragastric inoculation with virulent type A F. tularensis and characterized the course of infection and the associated host responses. Both immunocompetent and immunodeficient mice were relatively susceptible to intragastric inoculation of type A F. tularensis with a 50% lethal dose (LD(50)) of 10(6) organisms, which was 100,000-fold higher than the LD(100) for intradermal or respiratory routes of infection. Mice deficient in gamma interferon or tumor necrosis factor receptors 1 and 2 were more susceptible than wild-type controls to oral infection with a high dose of the pathogen. After oral inoculation, F. tularensis appeared first in the mesenteric lymph nodes (MLN) and then rapidly spread to the livers and spleens, where the organism multiplied to high numbers and induced marked neutrophilic infiltration and severe tissue necrosis. Infected mice showed rapid increases in tissue cytokine mRNA expression, which peaked in the MLN at 2 days postinfection (dpi) and in the liver and spleen at 3 dpi. The levels of gamma interferon, interleukin-1beta (IL-1beta), IL-6, tumor necrosis factor alpha, macrophage inflammatory protein 1alpha, KC, interferon-inducible protein 10, and monocyte chemotactic protein 1 were elevated from day 2 postinoculation onward. Moreover, mice intradermally immunized with the live vaccine strain of F. tularensis showed little survival advantage over naive mice after oral challenge with type A F. tularensis. These results suggest that type A F. tularensis is an effective oral pathogen that can cause fatal systemic infection and could pose a public health concern, particularly to immunocompromised individuals, if ingested in contaminated water and food.
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MESH Headings
- Animals
- Bacterial Vaccines/administration & dosage
- Colony Count, Microbial
- Cytokines/biosynthesis
- Disease Models, Animal
- Female
- Francisella tularensis/growth & development
- Francisella tularensis/immunology
- Francisella tularensis/pathogenicity
- Gene Expression
- Histocytochemistry
- Immunocompromised Host
- Interferon-gamma/deficiency
- Lethal Dose 50
- Liver/microbiology
- Liver/pathology
- Lymph Nodes/microbiology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Receptors, Tumor Necrosis Factor/deficiency
- Spleen/microbiology
- Spleen/pathology
- Tularemia/immunology
- Tularemia/pathology
- Tularemia/prevention & control
- Vaccines, Attenuated/administration & dosage
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Huang Q, Li X, Chen W, Weiss LM. Absence of JAK-2V617F point mutations in multiple myeloma. Leukemia 2007; 21:813-4; author reply 814-5. [PMID: 17230225 DOI: 10.1038/sj.leu.2404551] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Chen W, Yang CC, Liao CY, Hung CL, Tsai SJ, Chen KF, Sheu HM, Zouboulis CC. Expression of sex-determining genes in human sebaceous glands and their possible role in the pathogenesis of acne. J Eur Acad Dermatol Venereol 2007; 20:846-52. [PMID: 16898909 DOI: 10.1111/j.1468-3083.2006.01663.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The human skin, especially the sebaceous gland, is a steroidogenic organ similar to the gonads and adrenal cortex, possessing all the enzymes required for steroid sex-hormone synthesis and metabolism. Factors regulating cutaneous steroidogenesis associated with disease status remain largely unknown. OBJECTIVE We hypothesized that transcription factors involved in sex formation and regulation of steroidogenesis in the classical steroidogenic organs are also expressed in the sebaceous glands. Their possible role in the pathogenesis of acne were investigated. METHODS We used reverse transcription polymerase chain reaction (RT-PCR), in situ hybridization and Western blotting to analyse the expression of SF-1, WT-1, SRY, SOX-9 and DAX-1 mRNAs and their proteins in cultured human sebocytes and the facial skin of acne patients. RESULTS The in situ hybridization study showed SOX-9 mRNA mainly localized in basal keratinocytes, the basal layer of the sebaceous glands and eccrine glands. Immortalized human sebaceous gland cells (SZ95) expressed mRNA for SOX-9, WT-1 and DAX-1 but not for SF-1 or SRY. The expression of DAX-1 protein was slightly inhibited by 10(-6) m oestradiol (E2) at 6 h but enhanced by 10(-6) m dihydrotestosterone (DHT) at 48 h. The facial expression of SOX-9 seemed to be higher in the acne-prone male patients, while DAX-1 was stronger in subjects without acne, although both were statistically insignificant. CONCLUSION Our findings confirm the expression of some sex-determining genes in human sebaceous glands. Further studies on a larger patient population including the normal controls are needed to elucidate the functional significance of these transcription factors in the pathogenesis of acne.
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Tabata Y, Chen W, Warrier M, Gibson A, Daines M, Khurana Hershey G. Allergy-driven Alternative Splicing of Interleukin-13 Receptor Alpha 2 Yields Distinct Membrane and Soluble Forms. J Allergy Clin Immunol 2007. [DOI: 10.1016/j.jaci.2006.12.314] [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]
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Chen W, Shen W, Chen M, Cai G, Liu X. Study on the relationship between lymphatic vessel density and distal intramural spread of rectal cancer. Eur Surg Res 2007; 39:332-9. [PMID: 17622763 DOI: 10.1159/000104837] [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] [Received: 02/03/2007] [Accepted: 05/02/2007] [Indexed: 02/05/2023]
Abstract
BACKGROUND The smallest safe margin of distal clearance for lower rectal cancer is very important for the operation. In a previous study, a few factors were found to play a role in distal intramural spread (DIS), but there are few data regarding the influence of lymphangiogenesis. We studied the relationship between lymphatic vessel density (LVD) and DIS of rectal cancer, analyzing the probable value of LVD in determining the length of distal resection of lower rectal cancer. METHODS Nine-two patients who had undergone curative resection of lower rectal cancer were included. The length of DIS, LVD and other clinicopathological factors were evaluated. Immunohistochemical lymphatic vessel staining with LYVE-1 (lymphatic vessel endothelial hyaluronan receptor) were performed to detect the LVD. RESULTS 44 cases had DIS (range 0.1-2.44, mean 0.31 cm), and cancer emboli were the most common modalities of DIS. The LVD of a peritumoral lesion was significantly higher than that of an intratumoral lesion; the LVD of the DIS subgroup was significantly higher than that of the no DIS subgroup, and the LVD of the 2 subgroups was significantly higher than that of normal rectal tissue. A significant correlation was shown by a rank correlation test between the length of DIS and the LVD at the periphery of the rectal cancer (n = 44, r = 0.755, p < 0.01). The LVD was also related to the extent of infiltration, lymphatic invasion and lymph node metastases. CONCLUSIONS Lymphangiogenesis plays an important role in rectal cancer cell metastasis and patients with a higher LVD have a better prognosis. The LVD is closely correlated with DIS. These findings may be helpful in determining the distal clearance length of rectal cancer.
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Wang X, Zhu J, Chen W, Cai L. Influence of micro-patterned laser surface texturing on the tribological performance. INTERNATIONAL JOURNAL OF COMPUTER APPLICATIONS IN TECHNOLOGY 2007. [DOI: 10.1504/ijcat.2007.015245] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zeiger R, Schatz M, Chen W, Yang S, Corrao M, Quinn V. The Burden Of Rhinitis In A Managed Care Organization (MCO). J Allergy Clin Immunol 2007. [DOI: 10.1016/j.jaci.2006.12.253] [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]
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Yu M, Li Z, Chen Y, Chen W. Improving Integrity and Reliability of Map Matching Techniques. ACTA ACUST UNITED AC 2006. [DOI: 10.5081/jgps.5.1.40] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Erdogan F, Chen W, Kirchhoff M, Kalscheuer VM, Hultschig C, Müller I, Schulz R, Menzel C, Bryndorf T, Ropers HH, Ullmann R. Impact of low copy repeats on the generation of balanced and unbalanced chromosomal aberrations in mental retardation. Cytogenet Genome Res 2006; 115:247-53. [PMID: 17124407 DOI: 10.1159/000095921] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Accepted: 05/19/2006] [Indexed: 11/19/2022] Open
Abstract
Low copy repeats (LCRs) are stretches of duplicated DNA that are more than 1 kb in size and share a sequence similarity that exceeds 90%. Non-allelic homologous recombination (NAHR) between highly similar LCRs has been implicated in numerous genomic disorders. This study aimed at defining the impact of LCRs on the generation of balanced and unbalanced chromosomal rearrangements in mentally retarded patients. A cohort of 22 patients, preselected for the presence of submicroscopic imbalances, was analysed using submegabase resolution tiling path array CGH and the results were compared with a set of 41 patients with balanced translocations and breakpoints that were mapped to the BAC level by FISH. Our data indicate an accumulation of LCRs at breakpoints of both balanced and unbalanced rearrangements. LCRs with high sequence similarity in both breakpoint regions, suggesting NAHR as the most likely cause of rearrangement, were observed in 6/22 patients with chromosomal imbalances, but not in any of the balanced translocation cases studied. In case of chromosomal imbalances, the likelihood of NAHR seems to be inversely related to the size of the aberration. Our data also suggest the presence of additional mechanisms coinciding with or dependent on the presence of LCRs that may induce an increased instability at these chromosomal sites.
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Chen W, Liu Y, Courtney HS, Bettenga M, Agrawal CM, Bumgardner JD, Ong JL. In vitro anti-bacterial and biological properties of magnetron co-sputtered silver-containing hydroxyapatite coating. Biomaterials 2006; 27:5512-7. [PMID: 16872671 DOI: 10.1016/j.biomaterials.2006.07.003] [Citation(s) in RCA: 287] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Accepted: 07/06/2006] [Indexed: 01/30/2023]
Abstract
Bacterial infection after implant placement is a significant rising complication. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. In this study, the effect of in vitro antibacterial activity and in vitro cytotoxicity of co-sputtered silver (Ag)-containing hydroxyapatite (HA) coating was evaluated. Deposition was achieved by a concurrent supply of 10 W to the Ag target and 300 W to the HA target. Heat treatment at 400 degrees C for 4 h was performed after 3 h deposition. X-ray diffraction, contact angles measurements, and surface roughness were used to characterize the coating surfaces. The RP12 strain of Staphylococcus epidermidis (ATCC 35984) and the Cowan I strain of Staphylococcus aureus were used to evaluate the antibacterial activity of the Ag-HA coatings, whereas human embryonic palatal mesenchyme cells, an osteoblast precursor cell line, were used to evaluate the in vitro cytotoxicity of the coatings. X-ray diffraction analysis performed in this study indicated peaks corresponding to Ag and HA on the co-sputtered Ag-HA surfaces. The contact angles for HA and Ag-HA surfaces were observed to be significantly lower when compared to Ti surfaces, whereas no significant difference in surface roughness was observed for all groups. In vitro bacterial adhesion study indicated a significantly reduced number of S. epidermidis and S. aureus on Ag-HA surface when compared to titanium (Ti) and HA surfaces. In addition, no significant difference in the in vitro cytotoxicty was observed between HA and Ag-HA surfaces. Overall, it was concluded that the creation of a multifunctional surface can be achieved by co-sputtering the osteoconductive HA with antibacterial Ag.
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Li J, Gong X, Yuan X, Zhou X, Chen W. 2408. Int J Radiat Oncol Biol Phys 2006. [DOI: 10.1016/j.ijrobp.2006.07.818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Reardon D, Cloughesy T, Rich J, Yung W, Cilea C, Mietlowski W, Yung L, Chen W, Lai A, Conrad C. 621 POSTER A phase I study of combination therapy with AEE788, a novel multitargeted inhibitor of ErbB and VEGF receptor family tyrosine kinases, and RAD001, a mTOR inhibitor in recurrent GBM patients. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70626-7] [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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Brookes K, Xu X, Chen W, Zhou K, Neale B, Lowe N, Anney R, Aneey R, Franke B, Gill M, Ebstein R, Buitelaar J, Sham P, Campbell D, Knight J, Andreou P, Altink M, Arnold R, Boer F, Buschgens C, Butler L, Christiansen H, Feldman L, Fleischman K, Fliers E, Howe-Forbes R, Goldfarb A, Heise A, Gabriëls I, Korn-Lubetzki I, Johansson L, Marco R, Medad S, Minderaa R, Mulas F, Müller U, Mulligan A, Rabin K, Rommelse N, Sethna V, Sorohan J, Uebel H, Psychogiou L, Weeks A, Barrett R, Craig I, Banaschewski T, Sonuga-Barke E, Eisenberg J, Kuntsi J, Manor I, McGuffin P, Miranda A, Oades RD, Plomin R, Roeyers H, Rothenberger A, Sergeant J, Steinhausen HC, Taylor E, Thompson M, Faraone SV, Asherson P. The analysis of 51 genes in DSM-IV combined type attention deficit hyperactivity disorder: association signals in DRD4, DAT1 and 16 other genes. Mol Psychiatry 2006; 11:934-53. [PMID: 16894395 DOI: 10.1038/sj.mp.4001869] [Citation(s) in RCA: 431] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder, starting in early childhood and persisting into adulthood in the majority of cases. Family and twin studies have demonstrated the importance of genetic factors and candidate gene association studies have identified several loci that exert small but significant effects on ADHD. To provide further clarification of reported associations and identify novel associated genes, we examined 1,038 single-nucleotide polymorphisms (SNPs) spanning 51 candidate genes involved in the regulation of neurotransmitter pathways, particularly dopamine, norepinephrine and serotonin pathways, in addition to circadian rhythm genes. Analysis used within family tests of association in a sample of 776 DSM-IV ADHD combined type cases ascertained for the International Multi-centre ADHD Gene project. We found nominal significance with one or more SNPs in 18 genes, including the two most replicated findings in the literature: DRD4 and DAT1. Gene-wide tests, adjusted for the number of SNPs analysed in each gene, identified associations with TPH2, ARRB2, SYP, DAT1, ADRB2, HES1, MAOA and PNMT. Further studies will be needed to confirm or refute the observed associations and their generalisability to other samples.
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Yang X, Chen W. In vitro microsomal metabolic studies on a selective mGluR5 antagonist MTEP: characterization of in vitro metabolites and identification of a novel thiazole ring opening aldehyde metabolite. Xenobiotica 2006; 35:797-809. [PMID: 16278192 DOI: 10.1080/00498250500230412] [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: 10/25/2022]
Abstract
In vitro liver microsomal studies revealed that [14C] MTEP (3-[2-methyl-1,3-thiazol-4-yl)ethynyl] pyridine) was metabolized into three major oxidative metabolites. Metabolite 1 (M1) was shown to be a hydroxymethyl metabolite; M2 was shown to be a pyridine oxide. Moreover, a novel aldehyde metabolite (M3) was identified from mouse liver microsomes. The structure of the aldehyde M3 was elucidated by LC/MS/MS. In addition, methoxyamine, an aldehyde-trapping agent, and accurate mass measurement using a high-resolution quadrupole-time of flight (Q-TOF) instrument, were used to confirm the proposed thiazole ring-opening structure of M3. A mechanism for aldehyde M3 formation was postulated based on MTEP incubation studies with 18O2 and H2 18O using mouse liver microsomes. MTEP was initially oxidized at sulfur, followed by subsequent C4-C5 of thiazole epoxidation, thiozole ring opening and further oxidative desulfation. This proposed thiazole ring-opening mechanism might represent a novel metabolism pathway for xenobiotics containing a thiazole moiety. Species differences in the metabolism of MTEP were observed in mouse, rat, dog, monkey and human liver microsomes. Mouse appears to generate all three oxidative metabolites to a greater extent than other species examined.
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Chen SC, Chen W, Hsu WH, Yu YH, Shih CM. Role of pleural fluid C-reactive protein concentration in discriminating uncomplicated parapneumonic pleural effusions from complicated parapneumonic effusion and empyema. Lung 2006; 184:141-5. [PMID: 16902838 DOI: 10.1007/s00408-005-2573-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2005] [Indexed: 12/01/2022]
Abstract
The aim of this study was to determine whether pleural fluid C-reactive protein (CRP) is useful in distinguishing complicated parapneumonic pleural effusion (CPPE) and empyema from uncomplicated parapneumonic pleural effusions (UPPE). A total of 69 consecutive patients with parapneumonic effusions were enrolled in the study: 29 with UPPE, 29 with CPPE, and 11 with empyema. Concentrations of standard biochemical parameters together with CRP in the pleural fluid were measured using an immunoturbidimetric assay. Pleural CRP was significantly higher in CPPE (11.6 mg/dl) and in empyema (12.2 mg/dl) than in UPPE (3.9 mg/dl). A cutoff value of 8.7 mg/dl for pleural CRP in the diagnosis of CPPE and empyema resulted in a sensitivity, specificity, and area under the receiver-operating characteristic curve (AUC) of 0.80, 0.97 and 0.94, respectively. Traditional lactic dehydrogenase (LDH) > or = 1000 U/L and glucose < or = 60 mg/dl can differentiate CPPE and empyema from UPPE, with the sensitivity, specificity, and AUC achieving 0.75/0.60.1.00/1.00,0.95/0.22, respectively. However, for the detection of CPPE and empyema, the combination of pleural fluid CRP > or = 8.7 mg/dl and LDH > or = 1000 U/L was valuable in achieving a sensitivity, specificity, and AUC of 0.97/1,00/0.95. This study suggests that measurement of pleural CRP can be useful in the workup of patients with a parapneumonic effusion in order to differentiate CPPE from UPPE.
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Cheng J, Jin Y, Xenopoulos A, Chen W, Wunderlich B, Diack M, Compton RN, Guiochon G. Motion and Disorder in the Plastic Crystal of the C70 Complex with Toluene by Solid State NMR and Thermal Analysis. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259408028220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Jin Y, Xenopoulos A, Cheng J, Chen W, Wunderlich B, Diack M, Jin C, Hettich RL, Compton RN, Guiochon G. Thermodynamic Characterization of the Plastic Crystal and Non-Plastic Crystal Phases of C70. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259408033780] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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