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Wang XH, Istepanian RSH, Song YH. Application of wavelet modulus maxima in microarray spots recognition. IEEE Trans Nanobioscience 2004; 2:190-2. [PMID: 15376908 DOI: 10.1109/tnb.2003.816230] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This paper presents a novel approach to recognize the microarray image spots. The approach is based on the detection of wavelet modulus maxima in the microarray images. The detected maxima is actually the contour of the spots and thus the spots are recognized precisely. Then, the intensities within the contour of the spots can be obtained with low error rate. The test results on example image show this is an effective approach, especially for those spots with low intensities.
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202
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Wang XH, Li DP, Wang WJ, Feng QL, Cui FZ, Xu YX, Song XH. Covalent immobilization of chitosan and heparin on PLGA surface. Int J Biol Macromol 2004; 33:95-100. [PMID: 14599590 DOI: 10.1016/s0141-8130(03)00072-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Chitosan and heparin were covalently immobilized onto a poly(lactic acid-co-glycolic acid) (PLGA) surface using N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC), N-hydroxysuccinimide (NHS) in a 2-morpholinoethane sulfonic acid (MES) buffer system. The properties of the modified PLGA surface and the control were investigated by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). The water contact angle of the modified film was greatly decreased and the element content on the surface of the films changed correspondingly. Platelet adhesion assay showed that blood compatibility of the chitosan/heparin modified film was improved while hepatocyte culture indicated that the cell compatibility of the modified film was enhanced.
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Wang XH, Yan GT, Wang LH, Hao XH, Zhang K, Xue H. The mediating role of cPLA2 in IL-1 beta and IL-6 release in LPS-induced HeLa cells. Cell Biochem Funct 2004; 22:41-4. [PMID: 14695653 DOI: 10.1002/cbf.1052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Studies were conducted to characterize a HeLa cell model by which the roles of the 85-kDa phospholipase A2 (cPLA2) in interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) release could be evaluated. At first, untreated HeLa cells were compared with lipopolysaccharide (LPS)-treated HeLa cells. The latter resulted in cPLA2 overexpression and an increased trend of IL-1 beta and IL-6 release. The indicated doses of 85-kDa cPLA2 antisense oligonucleotide directed against the initiation site were then used to block cPLA2 in LPS-induced HeLa cells. The process led to a dose-dependent decrease in cPLA2 protein with no noticeable change of cPLA2 mRNA. Compared with that of LPS added only, a reduction of IL-1 beta and IL-6 levels in the supernatants of transfected cells following the repression of cPLA2 was observed. These results suggested that 85-kDa cPLA2 may mediate the signalling cascades by which IL-1 beta and IL-6 were released in LPS-induced HeLa cells.
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204
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Wang XH, Kivshar YS, Gu BY. Giant lamb shift in photonic crystals. PHYSICAL REVIEW LETTERS 2004; 93:073901. [PMID: 15324237 DOI: 10.1103/physrevlett.93.073901] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2004] [Indexed: 05/24/2023]
Abstract
We obtain a general result for the Lamb shift of excited states of multilevel atoms in inhomogeneous electromagnetic structures and apply it to study atomic hydrogen in inverse-opal photonic crystals. We find that the photonic-crystal environment can lead to very large values of the Lamb shift, as compared to the case of vacuum. We also suggest that the position-dependent Lamb shift should extend from a single level to a miniband for an assembly of atoms with random distribution in space, similar to the velocity-dependent Doppler effect in atomic/molecular gases.
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Li HM, Zhuang ZH, Wang Q, Pang JCS, Wang XH, Wong HL, Feng HC, Jin DY, Ling MT, Wong YC, Eliopoulos AG, Young LS, Huang DP, Tsao SW. Epstein–Barr virus latent membrane protein 1 (LMP1) upregulates Id1 expression in nasopharyngeal epithelial cells. Oncogene 2004; 23:4488-94. [PMID: 15064751 DOI: 10.1038/sj.onc.1207580] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nasopharyngeal carcinoma is closely associated with Epstein-Barr virus (EBV) infection. The EBV-encoded LMP1 has cell transformation property. It suppresses cellular senescence and enhances cell survival in various cell types. Many of the downstream events of LMP1 expression are mediated through its ability to activate NF-kappaB. In this study, we report a novel function of LMP1 to induce Id1 expression in nasopharyngeal epithelial cells (NP69) and human embryonal kidney cells (HEK293). The Id1 is a basic helix-loop-helix (bHLH) protein and a negative transcriptional regulator of p16(INK4a). Expression of Id1 facilitates cellular immortalization and stimulates cell proliferation. With the combination of both specific chemical inhibitors and genetic inhibitors of cell signaling, we showed that induction of Id1 by LMP1 was dependent on its NF-kappaB activation domain at the carboxy-terminal region, CTAR1 and CTAR2. Induction of Id1 by LMP1 may facilitate clonal expansion of premalignant nasopharyngeal epithelial cells infected with EBV and may promote their malignant transformation.
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Istepanian R, Philip N, Wang XH, Laxminarayan S. Non-telephone healthcare: the role of 4G and emerging mobile systems for future m-health systems. Stud Health Technol Inform 2004; 103:465-70. [PMID: 15747957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The next generation of "m-health technologies" is a new and evolving topic in the areas of telemedical and telecare systems. These technologies involve the exploitation of mobile telecommunication and multimedia technologies to provide better access to healthcare personnel on the move, by removing the key disadvantage of trailing wires in current systems. These technologies provide equal access to medical information and expert care by overcoming the boundaries of separation that exist today between different users of such medical information. A great benefit to all users will be a more efficient use of resources and far greater location independence. In this paper we will address some notes and future trends in these emerging areas and their applications for m-health systems. Especially we will discuss the role of 4G and emerging mobile systems for future m-health systems. The new technologies can make the remote medical monitoring, consulting, and health care more flexible and convenient. But, there are challenges for successful wireless telemedicine, which are addressed in this paper.
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207
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Wang XH, Istepanian RSH, Song YH. Microarray image enhancement by denoising using stationary wavelet transform. IEEE Trans Nanobioscience 2003; 2:184-9. [PMID: 15376907 DOI: 10.1109/tnb.2003.816225] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Microarray imaging is considered an important tool for large scale analysis of gene expression. The accuracy of the gene expression depends on the experiment itself and further image processing. It's well known that the noises introduced during the experiment will greatly affect the accuracy of the gene expression. How to eliminate the effect of the noise constitutes a challenging problem in microarray analysis. Traditionally, statistical methods are used to estimate the noises while the microarray images are being processed. In this paper, we present a new approach to deal with the noise inherent in the microarray image processing procedure. That is, to denoise the image noises before further image processing using stationary wavelet transform (SWT). The time invariant characteristic of SWT is particularly useful in image denoising. The testing result on sample microarray images has shown an enhanced image quality. The results also show that it has a superior performance than conventional discrete wavelet transform and widely used adaptive Wiener filter in this procedure.
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208
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Wang XH, Gu BY, Wang R, Xu HQ. Decay kinetic properties of atoms in photonic crystals with absolute gaps. PHYSICAL REVIEW LETTERS 2003; 91:113904. [PMID: 14525429 DOI: 10.1103/physrevlett.91.113904] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2002] [Indexed: 05/24/2023]
Abstract
Decay kinetic properties of a two-level atom near the band edges of photonic crystals (PCs) with absolute gaps are studied based on the Green's function expression for the evolution operator. The local coupling strength between the photons and an atom is evaluated by an exact numerical method. It is found that the decay behavior of an excited atom can be fundamentally changed by the variation of the atomic position: Weisskopf-Wigner and non-Weisskopf-Wigner decay phenomena occur at different atomic positions in the PCs as a result of a significant difference in the local coupling strength. Our finding implies that it is possible to engineer the luminescence spectrum by controlling the atomic position.
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209
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Tachakra S, Wang XH, Istepanian RSH, Song YH. Mobile e-Health: The Unwired Evolution of Telemedicine. Telemed J E Health 2003; 9:247-57. [PMID: 14611692 DOI: 10.1089/153056203322502632] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The movement of telemedicine from desktop platforms to wireless and mobile configurations may have a significant impact on future health care. This paper reviews some of the latest technologies in wireless communication and their application in health care. The new technologies can make the remote medical monitoring, consulting, and health care more flexible and convenient. But, there are challenges for successful wireless telemedicine, which are addressed in this paper.
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210
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Wang XH, Li DP, Wang WJ, Feng QL, Cui FZ, Xu YX, Song XH, van der Werf M. Crosslinked collagen/chitosan matrix for artificial livers. Biomaterials 2003; 24:3213-20. [PMID: 12763448 DOI: 10.1016/s0142-9612(03)00170-4] [Citation(s) in RCA: 212] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Matrices composed of collagen and chitosan may create an appropriate environment for the regeneration of livers. In this study, we have prepared, characterized and evaluated a new collagen/chitosan matrix (CCM). The CCM was made by using crosslinking agent 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) in N-hydroxysuccinimide (NHS) and a 2-morpholinoethane sulfonic acid (MES) buffer system. The chemical characteristics were evaluated by Fourier-transformed infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The mechanical strength was measured by tensile tests. The platelet deposition and hepatocyte culture experiments show that CCM has excellent blood and cell compatibility. The results suggest that the CCM is a promising candidate matrix for implantable bioartificial livers.
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212
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Wang JS, Zhu QR, Wang XH. Breastfeeding does not pose any additional risk of immunoprophylaxis failure on infants of HBV carrier mothers. Int J Clin Pract 2003; 57:100-2. [PMID: 12661791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
Whether babies born to hepatitis B (HB) carrier mothers with HB immunoprophylaxis at birth can be breastfed safely is controversial. A total of 230 such babies were followed up for one year to assess the influence of feeding method on the efficacy of HB immunoprophylaxis. The positive rates of anti-HBs at different ages are not statistically different between the breastfed group and the bottle-fed group. At 1 year, the rate was 80.9% in the breastfed group and 73.2% in the bottle-fed group in infants with HB vaccine alone, and 90.9% in the breastfed group and 90.3% in the bottle-fed group in infants with HBIG plus HB vaccine. There were no significant differences in the incidence of immunoprophylaxis failure between breastfed and bottle-fed babies. The results indicated that breastfeeding does not have a negative influence on the response of anti-HBs and on the failure rates of immunoprophylaxis in the infants born to HB carrier mothers.
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213
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Wong YC, Wang XH, Ling MT. Prostate Development and Carcinogenesis. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 227:65-130. [PMID: 14518550 DOI: 10.1016/s0074-7696(03)01008-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The process involved in the development and carcinogenesis of the prostate gland is complex. During early prostate development, the androgenic hormone from embryonic testicles is required for ductal formation, growth, and branching morphogenesis of the prostate gland. From this early stage, interactions between the epithelium and mesenchyme become firmly established through paracrine influence (i.e., growth factors) from mesenchyme (stroma), in response to testosterone, acting on epithelium to stimulate its proliferation, morphogenetic differentiation, and function. In return, the epithelium also exerts its paracrine effects on mesenchyme by regulating the differentiation and specific organizational pattern of its stromal smooth muscle. In a normal adult prostate, the maintenance of normal glandular structure and function is dependent not only on the constant presence of testosterone, but also on a normal intact and stable stroma. This chapter will concentrate first on factors involved in the normal development of the prostate gland and then on the aberrant changes in the homeostatic balance arising either from within (i.e., mutations) or outside (i.e., changes in hormonal balance) that result in derangements of the prostate gland. Finally, environmental and genetic factors that lead to prostate carcinogenesis including activation of oncogenes and mutations of tumor suppressor genes are also discussed.
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214
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Tan YP, Lin Q, Wang XH, Joshi S, Hew CL, Leung KY. Comparative proteomic analysis of extracellular proteins of Edwardsiella tarda. Infect Immun 2002; 70:6475-80. [PMID: 12379732 PMCID: PMC130330 DOI: 10.1128/iai.70.11.6475-6480.2002] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
A comparison of extracellular proteins of virulent and avirulent Edwardsiella tarda strains revealed several major, virulent-strain-specific proteins. Proteomic analysis identified two of the proteins in the virulent strain PPD130/91 as flagellin and SseB, which are virulence factors in bacterial pathogens. PCR amplification and DNA sequencing confirmed the presence of the genes that encode these proteins. Our results clearly demonstrated the potency of the proteomic approach in identifying virulence factors.
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215
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Wang XH, Wang R, Gu BY, Yang GZ. Decay distribution of spontaneous emission from an assembly of atoms in photonic crystals with pseudogaps. PHYSICAL REVIEW LETTERS 2002; 88:093902. [PMID: 11864006 DOI: 10.1103/physrevlett.88.093902] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2001] [Indexed: 05/23/2023]
Abstract
Spontaneous decay behaviors from an assembly of atoms (or molecules) in 3D photonic crystals (PC's) with pseudogaps are investigated. Theoretically, a lifetime distribution function for these atoms or molecules is defined to reveal decay kinetics. Our calculations show that quite wide or narrow lifetime distributions can occur for different spread configurations of the atoms (or molecules). The pure PC effect may lead to coexistence of both accelerated and inhibited decay processes. These results provide theoretical clarification for substantial discrepancies in the recent reported experiments.
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216
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Jeffs SA, Gorny MK, Williams C, Revesz K, Volsky B, Burda S, Wang XH, Bandres J, Zolla-Pazner S, Holmes H. Characterization of human monoclonal antibodies selected with a hypervariable loop-deleted recombinant HIV-1(IIIB) gp120. Immunol Lett 2001; 79:209-13. [PMID: 11600200 DOI: 10.1016/s0165-2478(01)00289-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Recombinant gp120 of the HIV-1(IIIB) isolate (BH10 clone) has been mutated to form the PR12 protein with the first 74 C-terminal amino acids and the V1, V2 and V3 hypervariable loops deleted. A variety of studies have shown that the CD4 binding domain (CD4bd) is very well exposed in PR12 in contrast to rgp120(LAI). Using PR12 for selection of human monoclonal antibodies (MAbs) from HIV-infected individuals, five MAbs were generated with specificities to the epitopes overlapping the CD4bd (1570A,1570C,1570D,1595 and 1599). The three MAbs, 1570A, C and D, generated from one HIV-infected individual, represent one MAb as determined by sequence analysis of the V(H)3 region. Since the epitopes overlapping the CD4bd exhibit variability among HIV-1 clades, the specificity of anti-CD4bd MAbs were distinguished by differing patterns of binding to recombinant envelope proteins derived from clade A, B, C, D and E viruses. The PR12-selected MAbs were also compared with a panel of gp120-selected anti-CD4bd MAbs and showed a different range of specificities. MAb 1599 is clade B specific, MAb 1595 reacts with the A, B and D clades, while MAb 1570 recognises the most conserved epitope, as it binds to all proteins. The results show that the exposure of different epitopes in the CD4bd of the PR12 protein allows this protein to serve as an immunogen and to induce anti-CD4bd antibodies.
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217
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Wang XH. Free energy fluctuations for bimodal directed polymers in 1+1 dimensions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 64:057102. [PMID: 11736143 DOI: 10.1103/physreve.64.057102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2001] [Indexed: 05/23/2023]
Abstract
By investigating the covariance between the free energy and the entropy, we studied the free energy fluctuations for bimodal directed polymers at finite temperatures. It is proposed that they have a phase transition from the KPZ behavior for p<p(c) to the EW behavior for p>p(c) for the free energy fluctuations at any finite temperature.
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Wang XH, Wang SQ, Wen SY, Guan W, Mao BZ. [The inhibitory effects of hepatocyte targeting pH-sensitive liposome mediated phosphorothioate antisense oligonucleotide on gene expression controlled by HCV 5'NCR]. SHENG WU GONG CHENG XUE BAO = CHINESE JOURNAL OF BIOTECHNOLOGY 2001; 17:626-30. [PMID: 11910753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Antisense oligodeoxynucleotide is a negative charged macromolecule and hence is difficult to penetrate cell membrane and liable to degradation. To increase the effective concentration of antisense drugs in the target cells, a hepatocyte-targeting liposome directed to asialoglycoprotein receptors exclusively expressing on the hepatocyte membrane was designed and prepared based on the receptor-mediated gene transfer. In order to accelerate endosomal exit of nucleic acid drugs, the liposomal formulation with pH-sensitive property was adopted. The hepatocyte-targeting and pH-sensitivity of liposome were analyzed by galactose-receptor competitive inhibition and hemolysis of chicken red blood cell. Antisense oligodeoxynucleotide, HCV363 against HCV 5'NCR, was delivered via prepared liposome to transgenic cell HepG2.9706 and evaluated for its inhibitory effect on luciferase expression controlled by HCV 5'NCR in HepG2.9706 using Luciferase Assay System The results showed that different concentrations (10, 20, 30 mmol/L) of galactose solutions reduce the delivery effects of liposome to some extend that were up to saturation when the concentrations of galactose solution exceed 20 mmol/L. Prepared liposomes mixed with chicken RBC are put into PBS buffers with different pH values(4.0-8.0), it was observed that the amount of heme is greatly released in acidic PBS (pH < 6) due to the fusion of liposome and RBC membranes. Liposome-mediated HCV363 has dose-dependent inhibitory activities on luciferase expression controlled by HCV 5'NCR in HepG2.9706 and the inhibitory rate is 86% at a concentration of 1.0 mumol/L. In conclusion, the liposome is proven to be a hepatocyte-targeting pH-sensitive delivery system that can increase the pharmaceutical effects of antisense drugs.
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Wang XH, Connor M, Wilson D, Wilson HI, Nicholson GM, Smith R, Shaw D, Mackay JP, Alewood PF, Christie MJ, King GF. Discovery and structure of a potent and highly specific blocker of insect calcium channels. J Biol Chem 2001; 276:40306-12. [PMID: 11522785 DOI: 10.1074/jbc.m105206200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We have isolated a novel family of insect-selective neurotoxins that appear to be the most potent blockers of insect voltage-gated calcium channels reported to date. These toxins display exceptional phylogenetic specificity, with at least a 10,000-fold preference for insect versus vertebrate calcium channels. The structure of one of the toxins reveals a highly structured, disulfide-rich core and a structurally disordered C-terminal extension that is essential for channel blocking activity. Weak structural/functional homology with omega-agatoxin-IVA/B, the prototypic inhibitor of vertebrate P-type calcium channels, suggests that these two toxin families might share a similar mechanism of action despite their vastly different phylogenetic specificities.
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220
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Potters L, Cao Y, Calugaru E, Torre T, Fearn P, Wang XH. A comprehensive review of CT-based dosimetry parameters and biochemical control in patients treated with permanent prostate brachytherapy. Int J Radiat Oncol Biol Phys 2001; 50:605-14. [PMID: 11395226 DOI: 10.1016/s0360-3016(01)01473-0] [Citation(s) in RCA: 223] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE The American Brachytherapy Society recommends that postprostate implant dosimetry be performed on all patients undergoing transperineal interstitial permanent prostate brachytherapy (TIPPB) utilizing CT scan clinical target volume reconstructions. This study was undertaken to assess the recommended dosimetry parameters from a large cohort of patients undergoing TIPPB that would predict for PSA relapse-free survival (PSA-RFS). METHODS AND MATERIALS Seven hundred nineteen consecutive patients with clinical stage T1/T2 adenocarcinoma of the prostate underwent TIPPB using either I-125 or Pd-103. Postimplant dosimetry was performed at 2 to 3 weeks with CT scan 3-dimensional reconstructions obtained on all patients. The D90 and D100 doses (defined as the minimum dose covering 90% and 100% of the prostate volume, respectively) and the V100 (defined as the percent of the prostate receiving 100% of the prescribed dose) were obtained for each patient. Regression analysis was performed on the D90 dose, D100 dose, and V100 to test for cutoff points that would predict for PSA-RFS, defined by a modification of the American Society for Therapeutic Radiology and Oncology consensus panel statement. A cutoff value was found and was subjected to subset analysis to assess for its robustness. Treatment-related factors were tested for their ability to achieve dosimetry at or above the cutoff dose. RESULTS The median follow-up from this cohort is 30 months (7-71 months) with a 48-month PSA-RFS of 89.5%. A D90 dose-response cutoff value > or =90% of the prescribed dose was identified. Prostate implants with a D90 dose <90% of the prescribed dose had an 80.4% 4-year PSA-RFS, while those with a D90 dose > or =90% of the prescribed dose had a 92.4% 4-year PSA-RFS (p = 0.001). No cutoff value was found for the V100 and D100 dose that predicted for PSA-RFS. Using the cutoff value, the D90 dose at 90% of the prescribed dose, a difference in 4-year PSA-RFS survival was identified for patients treated with I-125 (p = 0.04), Pd-103 (p = 0.01), TIPPB as monotherapy (p = 0.001), the addition of hormone therapy (p = 0.005), and TIPPB without hormone therapy (p = 0.001). The D90 dose was not significant for the group of patients treated with external beam radiotherapy and TIPPB (p = 0.15). The only significant finding from Cox regression analysis to predict for a poor D90 dose (<90% of the prescribed dose) was a CT/TRUS volume ratio >1.5 (p = 0.02). CONCLUSIONS The American Brachytherapy Society recommends that postimplant CT-based dosimetry be performed for all patients treated with TIPPB. This prospective study identified that the D90 dose > or =90% of the prescribed dose can be used as a factor for predicting PSA-RFS in patients treated with brachytherapy. A dose-response using the D90 dose was observed for several typical clinical treatment variations used in the practice of TIPPB. Using the D90 dose appears to be a satisfactory parameter for predicting outcome in patients treated with TIPPB.
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Pisters LL, Wang XH, Chung LW, Hsieh JT. Differential expression of c-erb B2/neu, epidermal growth factor receptor, cytokeratin 8, and the prostatic steroid-binding protein gene in rat ventral prostate during postnatal development. Prostate 2001; 47:164-71. [PMID: 11351345 DOI: 10.1002/pros.1059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The development and progression of prostate neoplasia may recapitulate the early developmental pattern of expression of genes in the prostate. The study of prostate development may, therefore, provide insights into the molecular mechanisms important in prostate neoplasia and reveal new markers. METHODS We compared postnatal expression of four genes: neu and epidermal growth factor receptor genes (EGFR), androgen-upregulated in the ventral prostate of adult rats (C-3), and androgen-repressed (CK8) in Sprague-Dawley rats. In situ hybridization was performed on prostate frozen sections collected on postnatal days 1, 5, 10, 15, 20, 30, and 60 from five rats per day. Staining intensities for antisense probes specific for each gene were determined relative to day 1 intensity. RESULTS Growth factor receptors including neu and EGFR may be coordinately regulated in the basal-cell population during prostate development. CK8 and C-3 show evidence of similar androgen regulation during development. CONCLUSIONS CK8 and C-3 have distinct patterns of expression in the postnatal period of development and these genes may be good markers of differentiation. Both neu and EGFR may be involved in androgen-independent growth of basal cell population in prostate. Prostate 47:164-171, 2001.
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Wang XH. Regular and anomalous scaling of a randomly advected passive scalar. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 63:047302. [PMID: 11308984 DOI: 10.1103/physreve.63.047302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2000] [Revised: 12/29/2000] [Indexed: 05/23/2023]
Abstract
Extending Kolmogorov's refined similarity hypothesis to study the inertial behavior <[T(x+r,t)-T(x,t)](2n)>~r(zeta(2n)) of a passive scalar T(x,t) advected by a rapidly changing incompressible velocity field, a random variable straight theta was introduced by Ching [Phys. Rev. Lett. 79, 3644 (1997)]. In this paper, the statistical distribution of the random variable X=straight theta/sqrt[<straight theta(2)>] is investigated analytically for the scaling in two limits, n-independent scaling zeta(2n)=zeta(2) and regular scaling zeta(2n)=nzeta(2), and numerically for the scaling of the Kraichnan conjecture zeta(2n)=1 / 2[sqrt[4ndzeta(2)+(d-zeta(2))(2)]-(d-zeta(2))]. For n-independent scaling zeta(2n)=zeta(2), the statistical distribution of X tends to an exponential distribution when zeta(2)-->0 or d-->infinity and to a Gaussian distribution when zeta(2)-->2 and d=2. For regular scaling zeta(2n)=nzeta(2), the statistical distribution of X tends to a Gaussian distribution when zeta(2)-->0 or d-->infinity. In d=2, there seems to be a phase transition for the probability density function P(X) from a convex to a concave function when the value of zeta(2) is increased and the critical point is zeta(2)=4/3 where the random variable X has a uniform distribution in [-sqrt[3],sqrt[3]]. In d=3, P(X) is a convex function for all 0<zeta(2)<2 and tends to a constant on its support [-sqrt[3],sqrt[3]] when zeta(2)-->2. For the scaling of the Kraichnan conjecture, P(X) has two peaks in d=2 for zeta(2)>1.33, but, in d=3, it has only one peak for all 0<zeta(2)<2 and changes very slowly with the value of X in the neighborhood of X=0 as zeta(2)-->2.
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Miller AE, McCulley JP, Bowman RW, Cavanagh HD, Wang XH. Patient satisfaction after LASIK for myopia. THE CLAO JOURNAL : OFFICIAL PUBLICATION OF THE CONTACT LENS ASSOCIATION OF OPHTHALMOLOGISTS, INC 2001; 27:84-8. [PMID: 11352454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
PURPOSE To determine satisfaction among patients treated with laser-in-situ-keratomileusis (LASIK) for various degrees of myopia (-0.75 D to -16.00 D) and myopic astigmatism (+0.50 D to +4.50 D) and assess factors which may affect satisfaction. METHODS One-hundred seventy-four consecutive patients treated with LASIK between November 1, 1997 and October 31, 1998 were surveyed. Charts were reviewed to collect refractive data. RESULTS Eighty-three patients (163 eyes) returned surveys for a response rate of 53%. Of the responders, 55% were female, the average age was 39.6 years (range 21-59), the mean preoperative sphere was -6.36 +/- 0.23 D, cylinder +0.94 +/- 0.07 D, and spherical equivalent-5.89 +/- 0.23 D. Ninety-six percent of eyes enjoyed freedom from corrective lenses following LASIK. Twenty-nine percent reported reduced night vision clarity following LASIK and 27% noted more eye dryness following LASIK. Overall, 84.8% were at least "very pleased" with the results of the procedure and 97% indicated that they would decide again to have LASIK. Uncorrected visual acuity and lower preoperative cylinder correlated positively with satisfaction, while increased postoperative dry eyes correlated negatively with satisfaction. CONCLUSIONS This study demonstrates a very high level of patient satisfaction following excimer laser treatment for myopia and myopic astigmatism. A great deal of literature has evaluated objective outcomes of LASIK, but this is one of few studies to examine patient satisfaction.
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Wang XH, Potters L. A theoretical derivation of the nomograms for permanent prostate brachytherapy. Med Phys 2001; 28:683-7. [PMID: 11339766 DOI: 10.1118/1.1359248] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
This study calculates the required minimum radioactivity to deliver a prescribed dose of radiation to a target using radioisotopes in permanent prostate brachytherapy. Assuming the radioactivity to be in a continuous form, an integral equation--Fredholm equation of the first kind, can be formulated with the radioactivity density used as the variable. The density distribution to produce a uniform volume dose rate is determined using a quadrature method and the radial profile behaves smoothly from the zero radius, and peaks sharply approaching the volume boundary. The density for Pd-103 is about 1.5 times that of I-125 due to its higher spatial attenuation. A nomogram is the relationship between the total activity per unit dose (A) and the dimension of the volume (d). Expressing the nomogram as A=c X dn U/Gy, then (c,n)= [(0.0098, 2.09) I-125] and [(0.031, 2.25) Pd-103]. Compared with the Memorial nomogram, (c,n)=[(0.011,2.2) I-125] and [(0.036,2.56) Pd-103], or that quoted by AAPM TG64, (c,n)=[(0.014,2.05) I-125] and [(0.056,2.22) Pd-103], our calculation determined an average 33% and 35% decrease for I-125, and 89% and 77% decrease for Pd-103, respectively. Two reasons for the extra total activity found in the Memorial and AAPM nomograms are: (a) An imperfect clinical situation limited by the restraints of implant techniques (e.g., use of templates) associated with the presence of adjacent normal organs, and (b) source discretization into seeds. When radioactivity is clumped as discrete seeds, higher activity is needed because of "wastage" in two aspects: (a) Dose cold-spots at intersource spaces, (b) hot-spots around the sources. Thus in theory, use of lower activity seeds will require less total activity to deliver a prescribed dose. Based on our study, Pd-103 delivers a higher therapeutic ratio and a lower integral dose to the patient compared to I-125.
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Anis AH, Lynd LD, Wang XH, King G, Spinelli JJ, Fitzgerald M, Bai T, Paré P. Double trouble: impact of inappropriate use of asthma medication on the use of health care resources. CMAJ 2001; 164:625-31. [PMID: 11258208 PMCID: PMC80815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND There is considerable controversy about the regular use of short-acting beta-agonists for the treatment of asthma. Although case-control studies have suggested that excessive use of these drugs may worsen asthma control and increase the risk of fatal or near-fatal asthma, the controversy remains unresolved because of the confounding that exists among disease control, disease severity and the use of short-acting beta-agonists. Whatever the cause-and-effect relation between the use of short-acting beta-agonists and disease severity, we hypothesized that their excessive use, in conjunction with underuse of inhaled corticosteroids, would be a marker for poorly controlled asthma and excessive use of health care resources. METHODS To characterize the pattern of health services utilization among asthmatic patients taking various doses of inhaled beta-agonists and corticosteroids in British Columbia, we linked the relevant health administrative databases. All patients between 5 and 50 years of age for whom a prescription for a short-acting beta-agonist was filled in 1995 and whose prescription data were captured through the provincial drug plan were included in a retrospective analysis of prescriptions for asthma drugs, physician prescribing patterns and health services utilization. Patients' use of asthma medication was classified as appropriate (low doses of short-acting beta-agonist and high doses of inhaled corticosteroid) or inappropriate (high doses of short-acting beta-agonist and low doses of inhaled corticosteroid), and the 2 resulting groups were compared, by means of logistic, Poisson and gamma regression, for differences in prescribing patterns, physician visits and use of hospital resources. RESULTS A total of 23,986 patients were identified as having filled a prescription for a short-acting beta-agonist (for inhalation) in 1995. Of these, 3069 (12.8%) filled prescriptions for 9 or more canisters of beta-agonist, and of this group of high-dose beta-agonist users, 763 (24.9%) used no more than 100 micrograms/day of inhaled beclomethasone. On average, those with inappropriate use of beta-agonists visited significantly more physicians for their prescriptions (1.8 v. 1.4), and each of these physicians on average wrote significantly more prescriptions for asthma medications per patient than the physicians who prescribed to appropriate users (5.2 v. 2.5 prescriptions). Patients with inappropriate use were more likely to be admitted to hospital (adjusted relative risk [RR] 1.68, 95% confidence interval [CI] 1.25-2.26), were admitted to hospital more frequently (adjusted RR 1.81, 95% CI 1.41-2.32) and were more likely to require emergency admission (adjusted RR 1.93, 95% CI 1.35-2.77). INTERPRETATION Despite the widespread distribution of guidelines for asthma pharmacotherapy, inappropriate use of asthma medications persists (specifically excessive use of inhaled short-acting beta-agonists combined with underuse of inhaled corticosteroids). Not only are patients who use medication inappropriately at higher risk for fatal or near-fatal asthma attacks, but, as shown in this study, they use significantly more health care resources than patients with appropriate medication use.
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