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Mitsuishi K, Liu ZQ, Shimojo M, Han M, Furuya K. Dynamic profile calculation of deposition resolution by high-energy electrons in electron-beam-induced deposition. Ultramicroscopy 2005; 103:17-22. [PMID: 15777596 DOI: 10.1016/j.ultramic.2004.11.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effect of the accelerating voltage of incident electrons on the resolution of electron-beam-induced deposition was investigated by a dynamic Monte Carlo profile simulator which includes the electron scattering in the already grown deposit structure. By simulating the deposition at two different accelerating voltages of 20 and 200 kV with an idealistic zero-diameter incident probe on a bulk substrate, it was revealed that the smaller size structures were attainable by 200 keV than by 20 keV. The effect of the substrate was also argued by comparing the above results with the simulation results obtained for a point-like starting substrate. Surprisingly, the shapes of the deposits grown on bulk substrates were reproduced well by the simulations starting from point-like substrates indicating the small effect of the substrate on the shape of deposits.
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Tanaka M, Shimojo M, Han M, Mitsuishi K, Furuya K. Ultimate sized nano-dots formed by electron beam-induced deposition using an ultrahigh vacuum transmission electron microscope. SURF INTERFACE ANAL 2005. [DOI: 10.1002/sia.1978] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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203
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Wiedmann M, Wang X, Tang X, Han M, Li M, Mao Z. PI3K/Akt-dependent regulation of the transcription factor myocyte enhancer factor-2 in insulin-like growth factor-1- and membrane depolarization-mediated survival of cerebellar granule neurons. J Neurosci Res 2005; 81:226-34. [PMID: 15931671 DOI: 10.1002/jnr.20556] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Survival signals such as insulin-like growth factor-1 (IGF-1) or membrane depolarization convey their neuronal protective effects through the activation of signaling networks and nuclear factors. In cerebellar granule neurons, IGF-1 mediates survival primarily through the PI3K/Akt pathway. The function of the transcription factor myocyte enhancer factor-2 (MEF2) is required for mediating membrane depolarization-dependent neuronal survival. However, whether PI3K/Akt regulates MEF2 and the role of MEF2 in IGF-1-mediated survival of neurons are unknown. In addition, the contribution of the PI3K/Akt pathway in membrane depolarization-induced neuronal survival remains undefined. We show here that the PI3K/Akt pathway promotes the survival of cerebellar granule neurons derived from Long-Evans rats following IGF-1 stimulation or membrane depolarization through regulation of MEF2 activity. IGF-1 stimulated the gene transactivation activity of MEF2 and its DNA binding potential. Moreover, regulation of MEF2 function by IGF-1 was dependent on the activity of the PI3K/Akt signaling pathway. Blocking MEF2 function reduced IGF-1-induced survival of cerebellar granule neurons. Membrane depolarization stimulated phosphorylation of Akt in cerebellar granule neurons. Blocking of the PI3K/Akt pathway with either a pharmacological inhibitor of PI3K, LY294002, or dominant negative mutants of PI3K and Akt inhibited the membrane depolarization-induced increase in MEF2 transactivation as well as its DNA binding activity and reduced neuronal survival. Together, these findings provide clear evidence to support an important role of the PI3K/Akt pathway in the regulation of nuclear survival factor MEF2 upon either IGF-1 stimulation or membrane depolarization, thus placing MEF2 as a novel downstream effector of the PI3K/Akt pathway in neurons.
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Fallena M, Han M, Stastny P. Natural killer (NK) cell crossmatch: Functional analysis of inhibitory KIR receptors and their HLA ligands. Hum Immunol 2004. [DOI: 10.1016/j.humimm.2004.07.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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205
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Guo Y, Han M, Tan Y, Tsai J, Giang C, Stastny P. HLA class I genes in the SHE ethnic minority of South China determined by multiplexed single nucleotide extension (MSNE). Hum Immunol 2004. [DOI: 10.1016/j.humimm.2004.07.214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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206
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Han M, Tan Y, Guo Y, Romphruk A, Leelayuwat C, Stastny P. Allele level typing of HLA-B locus by multiplexed single nucleotide extension (MSNE) and a study of b15 in different ethnic groups. Hum Immunol 2004. [DOI: 10.1016/j.humimm.2004.07.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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207
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Englbrecht C, Han M, Mader M, Osanger A, Mayer K. Curated databases and their role in clinical bioinformatics. Yearb Med Inform 2004. [DOI: 10.1055/s-0038-1638188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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208
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Shimojo M, Mitsuishi K, Tanaka M, Han M, Furuya K. Application of transmission electron microscopes to nanometre-sized fabrication by means of electron beam-induced deposition. J Microsc 2004; 214:76-9. [PMID: 15049871 DOI: 10.1111/j.0022-2720.2004.01307.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electron beam-induced deposition was carried out using a scanning transmission electron microscope with a field emission gun to fabricate nanometre-sized structures. A small amount of a metal-organic gas was introduced near the substrate in the microscope chamber, and focused electron beams were irradiated. Two- and three-dimensional structures were fabricated by scanning the beam position. The minimum line width of the freestanding structures was 8 nm at a constant gas flux used. This line width of 8 nm is considered to be achieved by employing a high accelerating voltage, which leads to a small probe size, and the optimum scanning speed.
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Englbrecht CC, Han M, Mader MT, Osanger A, Mayer KFX. Curated databases and their role in clinical bioinformatics. Yearb Med Inform 2004:121-136. [PMID: 27706315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023] Open
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210
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Han M, He QP, Yong G, Siesjö BK, Li PA. NXY-059, a nitrone with free radical trapping properties inhibits release of cytochrome c after focal cerebral ischemia. Cell Mol Biol (Noisy-le-grand) 2003; 49:1249-52. [PMID: 14983994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Recent studies have demonstrated that disodium 2,4-disulfophenyl-N-tert-butylnitrone (NXY-059), a novel nitrone with free radical trapping properties, has a considerable neuroprotective effect against cerebral ischemic injury. The mechanisms of its action have not been fully defined. In order to evaluate whether NXY-059 exerts its protective effects by inhibiting the release of cytochrome c, a key initiator of programmed cell death pathway, we have studied the effects of NXY-059 on reducing infarct volume and on inhibiting cytochrome c release from the mitochondria after transient focal cerebral ischemia. Wistar rats were subjected to 2 hr of middle cerebral artery occlusion and perfusion-fixed after 4, 6, 12, and 24 hr of reperfusion. NXY-059 (30 mg/kg) was i.v. injected 1 hr after reperfusion and followed immediately by 30 mg/kg/hr continuous i.v. infusion for the entire reperfusion period. The results showed that NXY-059 reduced infarct volume from 37.2% to 12.5% (p<0.0001). Immunocytochemistry demonstrated that the release of cytochrome c increased at 6 hr, peaked at 12 and 24 hr of reperfusion. NXY-059 treatment prevented ischemia-induced cytochrome c release. NXY-059 may reduce ischemic brain damage through suppressing the cell death pathway that is initiated by cytochrome c release.
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Han M, Zhang Y, Giang C, Tan Y, Stastny P. Single nucleotide extension (SNE) with multiplexed polystyrene beads: a robust, high-throughput method for HLA-A locus typing. Hum Immunol 2002. [DOI: 10.1016/s0198-8859(02)00477-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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212
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Zhang Y, Han M, Giang C, Vorhaben R, Lavingia B, Stastny P. Study of MICA in 201 African Americans by flow cytometry-based single nucleotide extension: a new platform for high-throughput DNA typing. Hum Immunol 2002. [DOI: 10.1016/s0198-8859(02)00519-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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213
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Han M. Thermodynamic and rheological variation in polysulfone solution by PVP and its effect in the preparation of phase inversion membrane. J Memb Sci 2002. [DOI: 10.1016/s0376-7388(01)00718-9] [Citation(s) in RCA: 337] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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214
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Kong K, Han M, Yeom HW, Miyamoto Y, Sugino O, Sasaki T, Ohno T, Yu BD. Novel pathway to the growth of diamond on cubic beta-SiC(001). PHYSICAL REVIEW LETTERS 2002; 88:125504. [PMID: 11909474 DOI: 10.1103/physrevlett.88.125504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2001] [Indexed: 05/23/2023]
Abstract
By carrying out first-principles calculations on diamond-forming processes, we predict a method for the heteroepitaxial growth of diamond on cubic beta-SiC(001). In the method, we used two processes: (i) the preformation of an sp(3)-like surface configuration of beta-SiC(001) by the adsorption of group-V surfactants; (ii) the successive growth of diamond by the segregation of the surfactants onto a surface and the desorption of surface hydrogen. Analyzing the segregation energies, we found that the atomic size effect plays a crucial role in the surfactant-mediated growth of diamond on beta-SiC(001).
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215
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Roberts WW, Bergstralh EJ, Blute ML, Slezak JM, Carducci M, Han M, Epstein JI, Eisenberger MA, Walsh PC, Partin AW. Contemporary identification of patients at high risk of early prostate cancer recurrence after radical retropubic prostatectomy. Urology 2002; 57:1033-7. [PMID: 11377299 DOI: 10.1016/s0090-4295(01)00978-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To develop a model that will identify a contemporary cohort of patients at high risk of early prostate cancer recurrence (greater than 50% at 36 months) after radical retropubic prostatectomy for clinically localized disease. Data from this model will provide important information for patient selection and the design of prospective randomized trials of adjuvant therapies. METHODS Proportional hazards regression analysis was applied to two patient cohorts to develop and cross-validate a multifactorial predictive model to identify men with the highest risk of early prostate cancer recurrence. The model and validation cohorts contained 904 and 901 men, respectively, who underwent radical retropubic prostatectomy at Johns Hopkins Hospital. This model was then externally validated using a cohort of patients from the Mayo Clinic. RESULTS A model for weighted risk of recurrence was developed: R(W)'=lymph node involvement (0/1)x1.43+surgical margin status (0/1)x1.15+modified Gleason score (0 to 4)x0.71+seminal vesicle involvement (0/1)x0.51. Men with an R(W)' greater than 2.84 (9%) demonstrated a 50% biochemical recurrence rate (prostrate-specific antigen level greater than 0.2 ng/mL) at 3 years and thus were placed in the high-risk group. Kaplan-Meier analyses of biochemical recurrence-free survival demonstrated rapid deviation of the curves based on the R(W)'. This model was cross-validated in the second group of patients and performed with similar results. Furthermore, similar trends were apparent when the model was externally validated on patients treated at the Mayo Clinic. CONCLUSIONS We have developed a multivariate Cox proportional hazards model that successfully stratifies patients on the basis of their risk of early prostate cancer recurrence.
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Wang Y, Healy T, Augustinus P, Baba M, Bao C, Flemming B, Fortes M, Han M, Marone E, Mehta A, Ke X, Kirby R, Kjerfve B, Schaeffer-Novelli Y, Wolanski E. Chapter Two Definition, properties, and classification of muddy coasts. PROCEEDINGS IN MARINE SCIENCE 2002. [DOI: 10.1016/s1568-2692(02)80076-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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217
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Park J, Jung Y, Han M, Lee S. Simultaneous removal of cadmium and turbidity in contaminated soil-washing water by DAF and electroflotation. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2002; 46:225-230. [PMID: 12523758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The removal of cadmium and turbidity from contaminated soil-washing water was studied by dissolved air flotation (DAF) and electroflotation at laboratory scale by using sodium lauryl sulfate (SLS) as an anionic surfactant, and calcium hydroxide (Ca(OH)2) as a coagulant. Using DAF, and in the presence of SLS or Ca(OH)2, the maximum recovery rate of cadmium obtained at a stoichiometric cadmium to collector and coagulant ratio of 1:4.5 was 51.1% and 80.8%, while the removal rate of turbidity was 18.4% and 19.2%. However, satisfactory cadmium and turbidity removal was not obtained by DAF. Much more significant removal of cadmium (100%, not detected in the residual) and turbidity (95.7%) was obtained by electroflotation using an aluminium metal plate as electrode, which generated hydroxide and aluminum ion. As a consequence, electroflotation is considered an effective method to separate cadmium and turbidity from contaminated soil-washing water. The electroflotation process may have practical applications for the removal of other hazardous metals from contaminated soil-washing water.
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218
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Starr DA, Hermann GJ, Malone CJ, Fixsen W, Priess JR, Horvitz HR, Han M. unc-83encodes a novel component of the nuclear envelope and is essential for proper nuclear migration. Development 2001; 128:5039-50. [PMID: 11748140 DOI: 10.1242/dev.128.24.5039] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nuclear migration plays an essential role in the growth and development of a wide variety of eukaryotes. Mutations in unc-84, which encodes a conserved component of the nuclear envelope, have been shown to disrupt nuclear migration in two C. elegans tissues. We show that mutations in unc-83 disrupt nuclear migration in a similar manner in migrating P cells, hyp7 precursors and the intestinal primordium, but have no obvious defects in the association of centrosomes with nuclei or the structure of the nuclear lamina of migrating nuclei. We also show that unc-83 encodes a novel transmembrane protein. We identified three unc-83 transcripts that are expressed in a tissue-specific manner. Antibodies against UNC-83 co-localized to the nuclear envelope with lamin and UNC-84. Unlike UNC-84, UNC-83 localized to only specific nuclei, many of which were migratory. UNC-83 failed to localize to the nuclear envelope in unc-84 mutants with lesions in the conserved SUN domain of UNC-84, and UNC-83 interacted with the SUN domain of UNC-84 in vitro, suggesting that these two proteins function together during nuclear migration. We favor a model in which UNC-84 directly recruits UNC-83 to the nuclear envelope where they help transfer force between the cytoskeleton and the nucleus.
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Pierce AJ, Hu P, Han M, Ellis N, Jasin M. Ku DNA end-binding protein modulates homologous repair of double-strand breaks in mammalian cells. Genes Dev 2001; 15:3237-42. [PMID: 11751629 PMCID: PMC312854 DOI: 10.1101/gad.946401] [Citation(s) in RCA: 414] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Chromosomal double-strand breaks (DSBs) in mammalian cells are repaired by either homology-directed repair (HDR), using a homologous sequence as a repair template, or nonhomologous end-joining (NHEJ), which often involves sequence alterations at the DSB site. To characterize the interrelationship of these two pathways, we analyzed HDR of a DSB in cells deficient for NHEJ components. We find that the HDR frequency is enhanced in Ku70(-/-), XRCC4(-/-), and DNA-PKcs(-/-) cells, with the increase being particularly striking in Ku70(-/-) cells. Neither sister-chromatid exchange nor gene-targeting frequencies show a dependence on these NHEJ proteins. A Ku-modulated two-ended versus one-ended chromosome break model is presented to explain these results.
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220
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Hirasawa K, Kim S, Hu J, Murata J, Han M, Jin C. Improvement of generalization ability for identifying dynamical systems by using universal learning networks. Neural Netw 2001; 14:1389-404. [PMID: 11771719 DOI: 10.1016/s0893-6080(01)00117-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This paper studies how the generalization ability of models of dynamical systems can be improved by taking advantage of the second order derivatives of the outputs with respect to the external inputs. The proposed method can be regarded as a direct implementation of the well-known regularization technique using the higher order derivatives of the Universal Learning Networks (ULNs). ULNs consist of a number of interconnected nodes where the nodes may have any continuously differentiable nonlinear functions in them and each pair of nodes can be connected by multiple branches with arbitrary time delays. A generalized learning algorithm has been derived for the ULNs, in which both the first order derivatives (gradients) and the higher order derivatives are incorporated. First, the method for computing the second order derivatives of ULNs is discussed. Then, a new method for implementing the regularization term is presented. Finally, simulation studies on identification of a nonlinear dynamical system with noises are carried out to demonstrate the effectiveness of the proposed method. Simulation results show that the proposed method can improve the generalization ability of neural networks significantly, especially in terms that (1) the robust network can be obtained even when the branches of trained ULNs are destructed, and (2) the obtained performance does not depend on the initial parameter values.
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Abstract
Vulval differentiation in Caenorhabditis elegans involves several fundamental cellular events, including cell fusion, division and migration. We have characterized the role of the lin-40 (also known as egr-1) gene in these cellular processes. LIN-40 is homologous to the metastasis-associated factor 1 (MTA1) in mammals, which has been identified as a component of the nucleosome remodeling and histone deacetylation (NuRD) complex that functions as a transcriptional co-repressor. We show here that lin-40 negatively regulates vulval fate specification at least partly by promoting cell fusion between the vulval precursor cells and the hypodermal syncytium at an early larval stage. This inhibitory function of lin-40 might be carried out by downregulating lin-39 Hox expression. We also show that lin-40 is specifically required for cell divisions along the transverse orientation during vulval morphogenesis.
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Chai XQ, Wen JK, Han M. [Effect of yiqi jianpi drugs on apoptosis and relevant gene expression in cultured vascular smooth muscle cell]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 2001; 21:909-12. [PMID: 12575593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To explore the effect of Yiqi Jianpi (YQJP, supplementing Qi and invigorating Spleen) recipe on vascular smooth muscle cells (VSMC) apoptosis and it's mechanisms. METHODS VSMC apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP nicked labeling (TUNEL) analysis, transmission electron microscope (TEM), flow cytometry and DNA agarose electrophoresis. The expression activity of bcl-2, c-myc and p53 genes were determined using Northern blotting. RESULTS The typical characteristics of apoptotic VSMC was observed following treatment by the YQJP drug serum. The DNA extracted from VSMC revealed a ladder pattern in electrophoresis. Flow cytometric analysis revealed G0/G1 stage cell blocking phenomena, the hypodiploid apoptotic cell increased, displayed typical peak of apoptosis, the rate of cell apoptosis and YQJP serum concentration were in a dose-dependent manner. The result of hybridization showed that 30% of YQJP serum could inhibit apoptotic gene bcl-2 expression, upregulated the level of apoptogenous gene c-myc and p53 mRNA. CONCLUSION VSMC apoptosis could be induced by YQJP recipe and its mechanism might be through affecting the apoptosis related gene expression activity.
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Chen Z, Han M. C. elegans Rb, NuRD, and Ras regulate lin-39-mediated cell fusion during vulval fate specification. Curr Biol 2001; 11:1874-9. [PMID: 11728311 DOI: 10.1016/s0960-9822(01)00596-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The tumor suppressor Rb and the NuRD (nucleosome remodeling and histone deacetylation) complex have been implicated in transcriptional repression during cell cycle progression and cell fate specification. The Rb/E2F complex physically interacts with and thus recruits the NuRD complex to actively repress transcription. Caenorhabditis elegans counterparts of Rb, E2F/DP, and some NuRD complex components appear to function in a common class B synthetic Multivulva (synMuv) pathway to antagonize RTK/Ras signaling during vulval fate specification. Therefore, it has been suggested that they function together in a single complex to repress vulva-specific gene transcription. However, little is known about the in vivo interactions between these class B synMuv genes and their relationships with other pathways in specific cellular processes during vulval development. We show that C. elegans Rb/E2F and NuRD complexes antagonize Ras activity by controlling a lin-39 Hox-mediated cell fusion event that regulates the competence of vulval cells. Interestingly, Rb/E2F and NuRD complexes exhibit very different genetic properties. While the NuRD complex negatively regulates lin-39 Hox activity, likely by downregulating its expression, RB/E2F appears to play dual roles in regulating lin-39: a negative role in controlling its activity and a previously uncharacterized positive role in regulating its expression.
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Spencer AG, Orita S, Malone CJ, Han M. A RHO GTPase-mediated pathway is required during P cell migration in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2001; 98:13132-7. [PMID: 11687661 PMCID: PMC60836 DOI: 10.1073/pnas.241504098] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2001] [Accepted: 09/24/2001] [Indexed: 11/18/2022] Open
Abstract
The Rho family of guanine triphosphate hydrolases controls various cellular processes, including cell migration. We describe here the demonstration of a role for a RhoA GTPase homologue during cell migration in Caenorhabditis elegans. We show that eliminating or reducing rho-1 gene function by using a dominant-negative transgene or dsRNA interference results in a severe defect in migration of hypodermal P cells to a ventral position. Biochemical and genetic data also suggest that unc-73, which encodes a Trio-like guanine nucleotide exchange factor, may act as an activator of rho-1 in the migration process. Mutations in let-502 ROCK, a homologue of a RhoA effector in mammals, also cause defects in P cell migration, suggesting that it may be one of several effectors acting downstream of rho-1 during P cell migration. Finally, we provide evidence to support the idea that other small Rac subfamily small GTPases act redundantly and in parallel to RHO-1 in this specific cell migration event.
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Barocas DA, Han M, Epstein JI, Chan DY, Trock BJ, Walsh PC, Partin AW. Does capsular incision at radical retropubic prostatectomy affect disease-free survival in otherwise organ-confined prostate cancer? Urology 2001; 58:746-51. [PMID: 11711353 DOI: 10.1016/s0090-4295(01)01336-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To evaluate the influence of isolated, histologically identified capsular incision (CI) (exposure of benign or malignant glands to the inked surgical margin in the setting of organ-confined disease) on disease progression after anatomic radical retropubic prostatectomy (RRP) for clinically localized prostate cancer. METHODS Between March 1993 and September 1999, 4747 men underwent RRP at the Johns Hopkins Hospital; 107 men (2.3%) were diagnosed with CI in otherwise organ-confined disease; 92 (86%) had at least 6 months (mean 30) of follow-up. We matched these CI cases (based on surgeon, age, clinical stage, final pathologic Gleason grade, and preoperative serum prostate-specific antigen level) one-for-one with controls in three additional pathologically defined groups and compared the freedom from disease progression (prostate-specific antigen level greater than 0.2 ng/mL and/or local palpable recurrence) after RRP. RESULTS The actuarial 3-year likelihood of freedom from disease progression was 87.8% for the CI group, 96.4% for men with organ-confined disease (P = 0.10), 91.3% for men with extraprostatic extension and negative surgical margins (P = 0.99), and 73.9% for men with positive surgical margins resulting from extraprostatic extension (P <0.01). No statistically significant difference was found in the actuarial likelihood of freedom from disease progression between men with CI into benign glands (n = 22) and men with CI into tumor (n = 70) (P = 0.93). CONCLUSIONS No statistically significant difference was found in the likelihood of early recurrence between patients with isolated CI and other specimen-confined disease. Patients with isolated CI have a significantly lower likelihood of early recurrence than patients with positive surgical margins due to extraprostatic extension, regardless of whether the CI is into benign glands or tumor. Long-term follow-up is necessary to confirm these findings.
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