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Tang M, Zhang R, Bowyer A, Eisenthal R, Hubble J. NAD-sensitive hydrogel for the release of macromolecules. Biotechnol Bioeng 2005; 87:791-6. [PMID: 15329937 DOI: 10.1002/bit.20210] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A hydrogel membrane containing immobilized ligands and receptors was synthesized and investigated for the controlled diffusion of test proteins (cytochrome C and hemoglobin). Both Cibacron blue (ligand) and lysozyme (receptor) were covalently linked to dextran molecules that were subsequently crosslinked to form a gel. The resulting stable hydrogels contained both covalent and affinity crosslinks such that their intrinsic porosities were sensitive to competitive displacers of the affinity interaction between lysozyme and Cibacron blue. Transport experiments in a twin chamber diffusion cell showed that as NAD was added to the donor side, the dissociation of the binding sites between the Cibacron blue and the lysozyme led to an increase in protein diffusion through the hydrogel. The results showed that addition of NAD caused a saturable concentration-dependent increase in the transport of both cytochrome C and hemoglobin. This effect was shown to be both specific and reversible.
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Hankey GJ, Eikelboom JW, Loh K, Tang M, Pizzi J, Thom J, Yi Q. Sustained Homocysteine-Lowering Effect over Time of Folic Acid-Based Multivitamin Therapy in Stroke Patients despite Increasing Folate Status in the Population. Cerebrovasc Dis 2005; 19:110-6. [PMID: 15608435 DOI: 10.1159/000082788] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Accepted: 08/11/2004] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND AIMS It is uncertain what impact increasing voluntary folate fortification may be having on the statistical power of randomized trials testing the homocysteine hypothesis of atherothrombosis. The objective of this study was to determine whether there has been a change in folate status between 1998 and 2002 in stroke patients randomized into the VITAmins TO Prevent Stroke (VITATOPS) Study at a single center in Perth, Australia, and what impact this may have had on the magnitude of the homocysteine-lowering effect achieved over time with folic acid-based multivitamin therapy. METHODS We conducted a randomized, double-blind, placebo-controlled study involving 285 patients with stroke or transient ischemic attack who were recruited between 1998 and 2002 and randomized to long-term folic acid 2.0 mg/day, pyridoxine 25 mg/day and cobalamin 0.5 mg/day (active VITATOPS medication) or placebo. Fasting plasma total homocysteine, red cell folate, serum cobalamin and serum pyridoxine levels were measured at baseline and 6 months, and the change in blood levels over 4 time quartiles and differences in levels between the two randomized treatments were examined. RESULTS Between 1998 and 2002, there was a significant rise in baseline mean red cell folate levels over 4 time quartiles among the entire stroke cohort (723.3, 780.1, 922.6 and 1,023.7 nmol/l in the first, second, third and fourth quartiles, respectively; p < 0.0001), but this was not associated with a spontaneous reduction in mean baseline total homocysteine levels during the same time period (12.7, 14.3, 12.1 and 12.8 micromol/l in the first, second, third and fourth quartiles, respectively; p = 0.55). The homocysteine-lowering effect of the active VITATOPS trial medication at 6 months after randomization also did not change significantly between 1998 and 2002 (difference between randomized groups: -4.1, -4.1, -3.1 and -3.6 micromol/l in the first, second, third and fourth quartiles, respectively; p = 0.56). CONCLUSIONS The homocysteine-lowering effect of the active VITATOPS trial medication has not attenuated significantly in the past 5 years despite increasing voluntary fortification of foods with folic acid as reflected by a progressive rise in baseline folate status. These data suggest that in the continuing absence of a program of mandatory folate fortification of food in populations served by centers participating in the VITATOPS trial, the study will remain adequately powered to test the homocysteine-lowering hypothesis for which it was designed.
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Baumgart K, Brown S, Gold M, Kemp A, Loblay R, Loh R, Mitrou D, Mullins R, Peake J, Ruhno J, Said M, Sinclair J, Smith V, Smith W, Solley G, Soutter V, Tang M, Ziegler J. ASCIA guidelines for prevention of food anaphylactic reactions in schools, preschools and child-care centres. J Paediatr Child Health 2004; 40:669-71. [PMID: 15569280 DOI: 10.1111/j.1440-1754.2004.00509.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
These guidelines have been developed by the anaphylaxis working party of the Australasian Society of Clinical Immunology and Allergy to provide advice for minimizing the risk of food-induced anaphylaxis in schools, preschools and child-care centres. The guidelines outline four steps for the prevention of food anaphylactic reactions in children at risk and food policy measures specific to school age and preschool age children.
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Kim DH, Kim SS, Lee HH, Jang HW, Kim JW, Tang M, Liang KS, Sinha SK, Noh DY. Oxidation Kinetics in Iron and Stainless Steel: An in Situ X-ray Reflectivity Study. J Phys Chem B 2004. [DOI: 10.1021/jp0479062] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Shi Y, Xu W, Yuan M, Tang M, Chen J, Pang Y. Expression of vip1/vip2 genes in Escherichia coli and Bacillus thuringiensis and the analysis of their signal peptides. J Appl Microbiol 2004; 97:757-65. [PMID: 15357725 DOI: 10.1111/j.1365-2672.2004.02365.x] [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: 11/26/2022]
Abstract
AIMS To determine the expression time courses and high expression level of Vip2A(c) and Vip1A(c) in Bacillus thuringiensis, and survey their insecticidal toxicity and insecticidal spectrum. METHODS AND RESULTS A kind of new vegetative insecticidal toxin genes encoded by a single operon from B. thuringiensis had been cloned and sequenced. The individual genes, 5-terminus truncated genes and the operon were respectively expressed in Escherichia coli. Only N-terminus deleted Vip2A(c) and Vip1A(c) proteins could be purified by Ni-NTA agarose, while others were processed and their N-terminal signal peptides were cleaved. The individual genes and the operon were also expressed in B. thuringiensis. Both proteins were mostly secreted into the cell supernatants. The expression level of Vip1A(c) was influenced because of the interruption of vip2A(c) gene on the operon. Bioassays showed that neither separate protein nor both performed any toxicity against tested lepidopteran and coleopteran insects. CONCLUSIONS Vip2A(c) and Vip1A(c) have similar secretion mechanism in E. coli and B. thuringiensis. Vip1A(c) remained its high expression level only when being expressed with vip2A(c) gene as an operon in B. thuringiensis. SIGNIFICANCE AND IMPACT OF THE STUDY Expression of vip2A(c) and vip1A(c) genes in E. coli and B. thuringiensis were investigated. This would help to make clear the secretion mechanism of VIP proteins and study the function of ADP-ribosyltransferase Vip2.
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Chan-Hui P, Shi Y, Tang M, Singh S. 590 Reduction of EGFR/Her-1 dimerization and phosphorylation in colorectal tumors and normal skin correlates with clinical response to Tarceva. EJC Suppl 2004. [DOI: 10.1016/s1359-6349(04)80598-6] [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] Open
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Hankey GJ, Eikelboom JW, Loh K, Yi Q, Pizzi J, Tang M, Hickling S, Le M, Klijn CJM, Dusitanond P, van Bockxmeer F, Gelavis A, Baker R, Jamrozik K. Is There Really a Power Shortage in Clinical Trials Testing the “Homocysteine Hypothesis?”. Arterioscler Thromb Vasc Biol 2004; 24:e147. [PMID: 15297291 DOI: 10.1161/01.atv.0000136385.50973.68] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Gray DA, Tsirigotis M, Brun J, Tang M, Zhang M, Beyers M, Woulfe J. Protective Effects of Mutant Ubiquitin in Transgenic Mice. Ann N Y Acad Sci 2004; 1019:215-8. [PMID: 15247017 DOI: 10.1196/annals.1297.035] [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: 11/12/2022]
Abstract
The K48R mutant ubiquitin can exert profound in vivo protective effects against a variety of insults, including agents of direct clinical relevance. The manipulation of the ubiquitin/proteasome pathway has enormous potential for clinical benefit, and it is not unreasonable to expect that such benefits will include diseases of aging.
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Mazella J, Tang M, Tseng L. Disparate effects of relaxin and TGFbeta1: relaxin increases, but TGFbeta1 inhibits, the relaxin receptor and the production of IGFBP-1 in human endometrial stromal/decidual cells. Hum Reprod 2004; 19:1513-8. [PMID: 15155604 DOI: 10.1093/humrep/deh274] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The purpose of this study was to determine the effect of progestin, relaxin (RLX) and transforming growth factor beta1 (TGFbeta1) on the content of relaxin receptor (LGR7) mRNA. The effect of RLX on insulin-like growth factor binding protein-1 (IGFBP-1) production was determined to evaluate the biological function of RLX/receptor in human endometrial cells. METHODS AND RESULTS The levels of LGR7 mRNA and the effect of hormones were determined by real-time PCR in endometrial cells. LGR7 mRNA was found to be relatively abundant in endometrial glands and decidual cells and much less in endometrial stromal cells. In stromal cells, medroxyprogesterone acetate (MPA), or MPA plus RLX, significantly increased the LGR7 mRNA and RLX alone had little effect. In decidual cells, RLX increased LGR7 mRNA in a dose- and time-dependent fashion. TGFbeta1 reduced the LGR7 mRNA. In stromal cells, MPA alone caused a slight increase (2-4-fold) of the production rate of IGFBP-1 whereas MPA plus RLX synergistically increased (>40-fold) the IGFBP-1 production. In decidual cells in which the basal production rate was already approximately 50-fold higher than in stromal cells, RLX alone caused an additional increase (>30-fold) on the production rate. TGFbeta1 inhibited the IGFBP-1 production. CONCLUSION The present study showed that in undifferentiated endometrial stromal cells, progestin increases the RLX receptor content to enhance the effect of RLX on the target gene (IGFBP-1). In decidual cells, RLX alone up-regulates its receptor, resulting in a large scale induction of IGFBP-1. TGFbeta1 has an inhibitory effect on LGR7 and IGFBP-1.
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Batchelor HK, Tang M, Dettmar PW, Hampson FC, Jolliffe IG, Craig DQM. Feasibility of a bioadhesive drug delivery system targeted to oesophageal tissue. Eur J Pharm Biopharm 2004; 57:295-8. [PMID: 15018987 DOI: 10.1016/j.ejpb.2003.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2003] [Revised: 09/08/2003] [Accepted: 10/07/2003] [Indexed: 11/24/2022]
Abstract
This contribution examines the feasibility of utilising an oesophageal-adhesive alginate layer to support model drug particles. Such a bioadhesive system offers the prospect of local drug delivery to the oesophagus, which in turn has applications in the treatment of conditions including gastro-oesophageal reflux disease and oesophageal cancer. Surface-modified (amine, carboxylate and sulfate) as well as neutral fluorescent beads were investigated as model drug particles. A fluorescence assay technique was utilised to quantify the extent and duration of adhesion of a fixed dose of these particles to excised porcine oesophageal tissue. Retention of the particles was investigated both from aqueous systems and within an adhesive alginate solution. After 30 min significantly higher adhesion of neutral beads was recorded from the alginate solution as compared to the aqueous suspension (n = 6, P < 0.05). The beads that possessed a negative charge showed significantly greater retention within the alginate carrier (n = 6, P < 0.05). However, the amine-modified beads showed retention profiles that were similar both within the alginate carrier and within the aqueous suspension (n = 6, P > 0.05).
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Shi J, Zhang S, Ma C, Liu X, Li T, Tang M, Han H, Guo Y, Zhao J, Zheng K, Kong X, Zhang K, Su Z, Zhao Z. Association between apolipoprotein CI HpaI polymorphism and sporadic Alzheimer's disease in Chinese. Acta Neurol Scand 2004; 109:140-5. [PMID: 14705977 DOI: 10.1034/j.1600-0404.2003.00193.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To investigate into the relationship of apolipoprotein CI (ApoCI) polymorphism with sporadic Alzheimer's disease (AD) in Chinese. SUBJECTS AND METHODS A total of 257 AD patients and 242 age-matched elderly individuals were genotyped for the ApoCI HpaI and apolipoprotein E (ApoE) HhaI polymorphisms. RESULTS The ApoCI A allele was associated with AD of moderate to severe dementia when patients were divided into two subgroups according to Clinical Dementia Rating scale, and the AA genotype was strongly associated with moderate to severe AD in ApoE epsilon4 allele carriers [odds ratio (OR) = 8.19, 95% confidential interval: 1.28-52.30, after adjusting for age and gender by logistic regression analysis], although in total no significant differences of allele or genotype frequency between patients and controls were found. CONCLUSION The present study partially confirmed the previous findings, suggesting that the ApoCI A allele might contribute to the susceptibility to moderate to severe sporadic AD in Chinese.
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Chen J, Yu J, Tang L, Tang M, Shi Y, Pang Y. Comparison of the expression of Bacillus thuringiensis full-length and N-terminally truncated vip3A gene in Escherichia coli. J Appl Microbiol 2003; 95:310-6. [PMID: 12859763 DOI: 10.1046/j.1365-2672.2003.01977.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Studies were performed to demonstrate the function of the putative signal peptide of Vip3A proteins in Escherichia coli. METHODS AND RESULTS The full-length vip3A-S184 gene was isolated from a soil-isolated Bacillus thuringiensis, and the vip3AdeltaN was constructed by deleting 81 nucleotides at the 5'-terminus of vip3A-S184. Both were transformed and expressed in E. coli. About 19.2% of Vip3A-S184 proteins secreted soluble proteins and others formed inclusion bodies in the periplasmic space. In contrast, the Vip3AdeltaN was insoluble and formed inclusion bodies in the cytoplasm. Bioassay indicated that Vip3A-S184 showed different toxicity against Spodoptera exigua, Helicoverpa armigera and S. litura, but Vip3AdeltaN showed no toxicity to either of them because of the deletion of the first 27 amino acids at the N-terminus. CONCLUSIONS The results suggest that the deleted N-terminal sequences were essential for the secretion of Vip3A-S184 protein in E. coli and might be required for toxicity. SIGNIFICANCE AND IMPACT OF THE STUDY The function of the putative signal peptide of Vip3A protein in E. coli was investigated. These would be helpful to make clear the unknown secretion pathway of Vip3A protein in B. thuringiensis and determine the receptor-binding domain or toxic fragment of Vip3A-S184 protein.
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Tang M, Shum P, Gong Y. Design of double-pass discrete Raman amplifier and the impairments induced by Rayleigh backscattering. OPTICS EXPRESS 2003; 11:1887-1893. [PMID: 19466071 DOI: 10.1364/oe.11.001887] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on the investigation of discrete Raman fiber amplifier in double-pass configuration based on the dispersion-compensated fiber and high reflection FBG. We proved in simulation and experiments that the double-pass configuration requires nearly 50% less pump power and the same fiber length to provide the same Raman gain and double-dispersion-compensation performance compared to the typical counter-pumped Raman amplifier. We also analyzed the equivalent noise figure (NF) and the Rayleigh backscattering impairments. The theoretical results shown that the impact of multipath interference (MPI) noise is the dominating limitation factor of this system operated at very high Raman gain region.
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Lee CK, Ma ESK, Tang M, Lam CCK, Lin CK, Chan LC. Prevalence and specificity of clinically significant red cell alloantibodies in Chinese women during pregnancy--a review of cases from 1997 to 2001. Transfus Med 2003; 13:227-31. [PMID: 12880393 DOI: 10.1046/j.1365-3148.2003.00445.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Guidelines for the prevention and management of red cell alloantibodies during pregnancy, related to anti-D in particular, are well established in Caucasian populations. However, because of the racial difference of the blood group distribution, applicability to Chinese is unknown as a result of insufficient data on the prevalence and their outcome. In a retrospective review of 28,303 (21,327 Chinese) antenatal attendances from 1997 to 2001, 213 (0.79%) women were found to have a total of 230 irregular antibodies. About 137 (0.64%) were ethnic Chinese, and a total of 160 irregular antibodies were identified in their blood samples. About 58 of these Chinese women (0.27%) were found to have 66 clinically significant antibodies. There was only one case of anti-D detected in an Rh(D)-negative subject. Our study shows the overall prevalence of clinically significant antibodies in Chinese women, which was not different from that of the Western population. However, the specificities of the antibodies differ with the commonest antibodies encountered; these being anti-Mi (57.6%), anti-E (19.7%), anti-S (10.6%) and anti-c (7.6%). Neonatal jaundice was observed in 37 babies and 10 of them required phototherapy. The findings support the previous recommendation that routine antenatal antibody screening for Chinese women may not be worthwhile except in Rh(D)-negative subjects or those with an antecedent history of haemolytic disease of the newborn (HDN). The relative high incidence of anti-Mi in the present study and the local population, in general, may warrant a large-scale prospective study of pregnancy outcome in these subjects, especially in the light of the previous case reports of HDN because of anti-Mi.
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Tang M, Zhang R, Bowyer A, Eisenthal R, Hubble J. A reversible hydrogel membrane for controlling the delivery of macromolecules. Biotechnol Bioeng 2003; 82:47-53. [PMID: 12569623 DOI: 10.1002/bit.10539] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Glucose-sensitive hydrogel membranes have been synthesized and characterized for their rate-of-delivery of macromolecules. The mechanism for changing this rate is based on variable displacement of the affinity interaction between dextran and concanavalin A (con A). Our main objective was to characterize the diffusion of model proteins (insulin, lysozyme, and BSA) through the membrane, in response to changes in environmental glucose concentrations. Membranes were constructed from crosslinked dextrans to which con A was coupled via a spacer arm. Changes in the porosity of the resulting hydrogel in the presence of glucose led to changes in the diffusion rate observed for a range of proteins. Gels of specified thickness were cast around to nylon gauze support (pore size, 0.1 mm) to improve mechanical strength. Diffusion of proteins through the gel membrane was determined using a twin-chamber diffusion cell with the concentrations being continuously monitored using a UV-spectrophotometer. Changes in the transport properties of the membranes in response to glucose were explored and it was found that, while 0.1M D-glucose caused a substantial, but saturateable, increase in the rates of diffusion of both insulin and lysozyme, controls using glycerol or L-glucose (0.1M) had no significant effect. Sequential addition and removal of external glucose in a stepwise manner showed that permeability changes were reversible. As expected, diffusion rates were inversely proportional to membrane thickness. A maximum increase in permeability was observed at pH 7.4 and at 37 degrees C. The results demonstrate that this hydrogel membrane functions as a smart material allowing control of solute delivery in response to specific changes in its external environment.
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Tang M, Harp JA, Wesley RD. Recombinant adenovirus encoding the HA gene from swine H3N2 influenza virus partially protects mice from challenge with heterologous virus: A/HK/1/68 (H3N2). Arch Virol 2002; 147:2125-41. [PMID: 12417948 DOI: 10.1007/s00705-002-0870-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Immunization with recombinant adenoviral vaccine that induces potent immunity has been applied to many infectious diseases. We report here developing a recombinant adenoviral vaccine encoding the HA gene from swine H3N2 influenza virus (SIV). Two replication-defective recombinant adenoviruses were generated: (1) rAd-HA: recombinant adenovirus encoding the HA gene from swine H3N2 influenza virus, and (2) rAd-vector: a control recombinant adenovirus containing adenovirus and transfer plasmids without a foreign HA gene. Mice given rAd-HA developed high titers of neutralizing and hemagglutination inhibition antibodies to SIV in comparison to mice inoculated with rAd-vector or PBS as early as 2 weeks after immunization, and these antibodies were substantially increased in the mice given rAd-HA within the next 3 weeks following the first dose. However, these antibodies were not able to neutralize the virus, A/HK/68 (H3N2), used for challenge. Nonetheless mice immunized with one or two doses of rAd-HA were protected from lethal challenge with heterologous virus, A/HK/1/68 (H3N2). A statistically significant ( P < 0.03) difference between survival rates of rAd-HA mice vs. rAd-vector or PBS mice was observed.
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Chen Y, Dales R, Tang M, Krewski D. Sex-related interactive effect of smoking and household pets on asthma incidence. Eur Respir J 2002; 20:1162-6. [PMID: 12449169 DOI: 10.1183/09031936.02.00273102] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The authors examined the interactive effect of smoking and pets at home on the incidence of asthma and the difference between sexes. The longitudinal data from the first two cycles of the National Population Health Survey, conducted in Canada, were used. A total of 12,636 subjects who reported no asthma at baseline were included in the analysis. The 2-yr cumulative incidence of asthma was higher in females than in males. Female sex and household pets demonstrated a significant interaction in the development of asthma. After adjustment for age, immigration and history of allergy, the odds ratio for smoking in relation to the asthma incidence was 2.50 (95% confidence interval: 1.24-5.05) for females who had pets at home and close to unity for those who had no pets. The incidence of asthma was not associated with smoking status and household pets in males. These results indicate that smoking, having pets at home and other environmental factors can partly explain asthma morbidity among female Canadians.
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Wistuba II, Maitra A, Carrasco R, Tang M, Troncoso P, Minna JD, Gazdar AF. High resolution chromosome 3p, 8p, 9q and 22q allelotyping analysis in the pathogenesis of gallbladder carcinoma. Br J Cancer 2002; 87:432-40. [PMID: 12177780 PMCID: PMC2376134 DOI: 10.1038/sj.bjc.6600490] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2002] [Revised: 04/29/2002] [Accepted: 06/07/2002] [Indexed: 12/15/2022] Open
Abstract
Our recent genome-wide allelotyping analysis of gallbladder carcinoma identified 3p, 8p, 9q and 22q as chromosomal regions with frequent loss of heterozygosity. The present study was undertaken to more precisely identify the presence and location of regions of frequent allele loss involving those chromosomes in gallbladder carcinoma. Microdissected tissue from 24 gallbladder carcinoma were analysed for PCR-based loss of heterozygosity using 81 microsatellite markers spanning chromosome 3p (n=26), 8p (n=14), 9q (n=29) and 22q (n=12) regions. We also studied the role of those allele losses in gallbladder carcinoma pathogenesis by examining 45 microdissected normal and dysplastic gallbladder epithelia accompanying gallbladder carcinoma, using 17 microsatellite markers. Overall frequencies of loss of heterozygosity at 3p (100%), 8p (100%), 9q (88%), and 22q (92%) sites were very high in gallbladder carcinoma, and we identified 13 distinct regions undergoing frequent loss of heterozygosity in tumours. Allele losses were frequently detected in normal and dysplastic gallbladder epithelia. There was a progressive increase of the overall loss of heterozygosity frequency with increasing severity of histopathological changes. Allele losses were not random and followed a sequence. This study refines several distinct chromosome 3p, 8p, 9q and 22q regions undergoing frequent allele loss in gallbladder carcinoma that will aid in the positional identification of tumour suppressor genes involved in gallbladder carcinoma pathogenesis.
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Dales RE, Choi B, Chen Y, Tang M. Influence of family income on hospital visits for asthma among Canadian school children. Thorax 2002; 57:513-7. [PMID: 12037226 PMCID: PMC1746352 DOI: 10.1136/thorax.57.6.513] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND A study was undertaken to investigate the mechanisms by which socioeconomic status may influence asthma morbidity in Canada. METHODS A total of 2968 schoolchildren aged 5-19 years with reported asthma were divided into three family income ranges. Hospital visits and risk factors for asthma, ascertained by questionnaire, were compared between the three groups. RESULTS The mean (SE) annual period prevalence of a hospital visit was 25.0 (3.1)% among schoolchildren with household incomes of less than $20 000 Canadian compared with 16.0 (1.3)% among those with incomes of more than $60 000 (p<0.05). Students with asthma from lower income households were more likely to be younger and exposed to environmental tobacco smoke and cats, and their parents were more likely to have a lower educational attainment and be unmarried (p<0.05). Across all income groups, younger age, lower parental education, having unmarried parents, and regular exposure to environmental tobacco smoke were each associated with an increase in risk of a hospital visit (p<0.05). No increased risk was detected due to sex, having pets, and not taking dust control measures. Although not statistically significant at p<0.05, there may have been an interactive effect between income and susceptibility to environmental tobacco smoke. In the lower income group those children who were regularly exposed to second hand smoke had a 79% higher risk of a hospital visit compared with a 45% higher risk in the higher income group. In a logistic regression model the association between income and hospital visit was no longer significant after adjusting for differences in reported exposure to passive smoking. CONCLUSION Socially disadvantaged Canadian schoolchildren have increased asthma morbidity. Exposure to cigarette smoke appears to be one important explanation for this observation.
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Hryciw T, Tang M, Fontanie T, Xiao W. MMS1 protects against replication-dependent DNA damage in Saccharomyces cerevisiae. Mol Genet Genomics 2002; 266:848-57. [PMID: 11810260 DOI: 10.1007/s00438-001-0605-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2001] [Accepted: 10/04/2001] [Indexed: 11/24/2022]
Abstract
A series of yeast mutants were isolated that are sensitive to killing by the monofunctional DNA-alkylating agent methyl methanesulfonate (MMS) but not by UV or X-radiation. We have cloned and characterized one of the corresponding genes, MMS1, and show that the mms1 Delta mutant is dramatically sensitive to killing by MMS and mildly sensitive to UV radiation. mms1 Delta mutants display an elevated level of spontaneous DNA damage and genomic instability. Furthermore, the mms1 Delta cells are sensitive to killing by conditions that induce replication-dependent double-strand breaks, such as treatment with camptothecin, and incubation of a cdc2-2 strain at the restrictive temperature. rad52 Delta is epistatic to mms1 Delta for MMS and camptothecin sensitivity, indicating that Mms1 acts in concert with Rad52. However, unlike mutants of the RAD52 group, mms1 Delta cells are not sensitive to gamma-rays, which induce double-strand breaks independently of DNA replication. Together these results suggest a role for an Mms1-dependent, Rad52-mediated, pathway in protecting cells against replication-dependent DNA damage.
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Bilsbury C, Tang M, Bilsbury J. The phenomenology of perfectionism: "yumpity". CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2001; 46:863-4. [PMID: 11761642 DOI: 10.1177/070674370104600921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Alrutz MA, Srivastava A, Wong KW, D'Souza-Schorey C, Tang M, Ch'Ng LE, Snapper SB, Isberg RR. Efficient uptake of Yersinia pseudotuberculosis via integrin receptors involves a Rac1-Arp 2/3 pathway that bypasses N-WASP function. Mol Microbiol 2001; 42:689-703. [PMID: 11722735 DOI: 10.1046/j.1365-2958.2001.02676.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Efficient uptake of Yersinia pseudotuberculosis into cultured mammalian cells is the result of high-affinity binding of invasin to beta1 chain integrins. We demonstrate here that uptake requires Rac1 and Arp 2/3 function. Bacterial uptake was stimulated by GTPgammaS, but was inhibited in mammalian cells transfected with the interfering Rac1-N17 derivative. Rac1 was found to be activated in response to integrin engagement by invasin, whereas Rac1 and Arp 2/3 were found to be intensely localized around phagosomes bearing bacteria, indicating a specific role for Rac1 signalling from the nascent phagosome to downstream effectors. To determine whether the Arp 2/3 complex was a component of this proposed pathway, cells overproducing various derivatives of Scar1/WAVE1, an Arp 2/3-binding protein, were analysed. Sequestration of Arp 2/3 away from the phagocytic cup as a result of Scar1/WAVE1 overproduction dramatically inhibited uptake. To determine whether signalling from Rac1 to Arp 2/3 occurred via N-WASP, uptake was analysed in a cell line lacking expression of WASP and N-WASP. Uptake was unaffected by the absence of these proteins, indicating that beta1 integrin signalling from Rac1 to Arp 2/3 can occur in the absence of N-WASP function.
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248
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Li M, Tang M, Deng X. [Positive immunoglobulin A expression in human epithelial carcinoma cell lines]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 2001; 23:451-3. [PMID: 11859707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE In the present study, we try to further elucidate which class of immunoglobulin is expressed in epithelial carcinoma cell lines. METHODS Three assays, immunohistochemistry, Western blot and enzyme-linked immunosorbent assay (ELISA) were used to detect the cellular protein extracts and the cultivated supernatant. RESULTS Seven human epithelial carcinoma cell lines, MCF-7 (human breast carcinoma cell line), SW480 (human colon carcinoma cell line), MGC (human gastric carcinoma cell line), HeLa (human cervical carcinoma cell line), HNE2, CNE1-LMP1 and Tet-on-LMP1-HNE2 (three human nasopharyngeal carcinoma cells) expressed IgA protein in their cellular extracts and cultivated supernatants. CONCLUSION Immunoglobulin is expressed in epithelium-derived carcinoma cell lines, which is in conflict with the traditional immunoglobulin theory. Our findings imply that the immunoglobulin expressed in epithelial carcinoma cells might play a role in the carcinogenesis of epithelium-derived carcinoma. Understanding the mechanism of immunoglobulin expression by cancer cells may possibly further facilitate the improvement techniques in cancer diagnosis, therapy or the mechanism of carcinogenesis.
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249
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Yoon JH, Smith LE, Feng Z, Tang M, Lee CS, Pfeifer GP. Methylated CpG dinucleotides are the preferential targets for G-to-T transversion mutations induced by benzo[a]pyrene diol epoxide in mammalian cells: similarities with the p53 mutation spectrum in smoking-associated lung cancers. Cancer Res 2001; 61:7110-7. [PMID: 11585742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
A large fraction of the p53 mutations in lung cancers from smokers are G-to-T transversions, a type of mutation that is infrequent in lung cancers from nonsmokers and in most other tumors. Previous studies have indicated that there is an association between G-to-T transversion hotspots in lung cancers and sites of preferential formation of polycyclic aromatic hydrocarbon adducts along the p53 gene. p53 codons containing methylated CpG sequences are preferential targets for formation of adducts by (+/-) anti-7beta,8alpha-dihydroxy-9alpha,10alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE). To assess the role of CpG methylation in induction of mutations by BPDE, we analyzed BPDE mutagenesis in three CpG methylated target genes: a supF shuttle vector and the cII and lacI transgenes in embryonic mouse fibroblasts. After methylation of the shuttle vector at all CpG sequences, 42% of all G-to-T transversions were at CpG sites compared with 23% in unmethylated DNA. In the cII transgene, which is methylated at CpG sequences in vivo, 83 of 147 (56%) of the BPDE-induced mutations were G-to-T transversions, and 58% (48 of 83) of all G-to-T transversions occurred at methylated CpG sequences. In the lacI gene, 68% (75 of 111) of the BPDE-induced mutations were G-to-T events, and 58 of 75 (77%) of these occurred at methylated CpG sequences. The occurrence of transversion hotspots at methylated CpGs correlated with high levels of BPDE adducts formed at such sites. This situation mirrors the one in the p53 gene in lung cancers from smokers where 236 of 465 (51%) of the G-to-T transversions occurred at methylated CpG sites. These findings further strengthen a link between polycyclic aromatic hydrocarbons present in cigarette smoke and lung cancer mutations and provide evidence that mutational processes other than C-to-T transition mutations can occur selectively at methylated CpG sequences.
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MESH Headings
- 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide/metabolism
- 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide/toxicity
- Animals
- Bacterial Proteins/genetics
- Base Sequence
- Carcinogens/metabolism
- Carcinogens/toxicity
- CpG Islands/drug effects
- CpG Islands/genetics
- DNA Adducts/genetics
- DNA Adducts/metabolism
- DNA Methylation
- Escherichia coli Proteins
- Fibroblasts/drug effects
- Fibroblasts/metabolism
- Fibroblasts/physiology
- Genes, Suppressor
- Genes, p53/genetics
- Genetic Vectors/genetics
- Humans
- Lac Repressors
- Lung Neoplasms/etiology
- Lung Neoplasms/genetics
- Mice
- Molecular Sequence Data
- Mutagenesis, Site-Directed/genetics
- Mutagens/metabolism
- Mutagens/toxicity
- RNA, Transfer/genetics
- Repressor Proteins/genetics
- Smoking/adverse effects
- Substrate Specificity
- Transcription Factors/genetics
- Transgenes/genetics
- Viral Proteins
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Abstract
This retrospective quasi-experimental study evaluated the effectiveness of an anger management group program for clients with mental health problems. The program, based on the cognitive-behavioral approach, was offered by outpatient mental health occupational therapy services of a community general hospital. Sixty-four clients, about 59% diagnosed with depressive disorder, enrolled in the program and participated in the study. The pre-treatment and post-treatment scores of the participants on the Anger Control Inventory and the State-Trait Anger Expression Inventory were compared. The results indicated significant reduction in the overall experience of intense anger, improvement in cognitive and behavioural coping mechanisms, and significant improvement in anger control after treatment. Most respondents (90%) found the program definitely helpful. The pace of the program and the variety of learning activities were identified as areas for improvement. The results showed the program had positive impact on anger management. Useful suggestions were identified for continuous quality improvements of the program.
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