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Middleton LJ, Champaneria R, Daniels JP, Bhattacharya S, Cooper KG, Hilken NH, O'Donovan P, Gannon M, Gray R, Khan KS, Abbott J, Barrington J, Bhattacharya S, Bongers MY, Brun JL, Busfield R, Sowter M, Clark TJ, Cooper J, Cooper KG, Corson SL, Dickersin K, Dwyer N, Gannon M, Hawe J, Hurskainen R, Meyer WR, O'Connor H, Pinion S, Sambrook AM, Tam WH, van Zon-Rabelink IAA, Zupi E. Hysterectomy, endometrial destruction, and levonorgestrel releasing intrauterine system (Mirena) for heavy menstrual bleeding: systematic review and meta-analysis of data from individual patients. BMJ 2010; 341:c3929. [PMID: 20713583 PMCID: PMC2922496 DOI: 10.1136/bmj.c3929] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/06/2010] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate the relative effectiveness of hysterectomy, endometrial destruction (both "first generation" hysteroscopic and "second generation" non-hysteroscopic techniques), and the levonorgestrel releasing intrauterine system (Mirena) in the treatment of heavy menstrual bleeding. DESIGN Meta-analysis of data from individual patients, with direct and indirect comparisons made on the primary outcome measure of patients' dissatisfaction. DATA SOURCES Data were sought from the 30 randomised controlled trials identified after a comprehensive search of the Cochrane Library, Medline, Embase, and CINAHL databases, reference lists, and contact with experts. Raw data were available from 2814 women randomised into 17 trials (seven trials including 1359 women for first v second generation endometrial destruction; six trials including 1042 women for hysterectomy v first generation endometrial destruction; one trial including 236 women for hysterectomy v Mirena; three trials including 177 women for second generation endometrial destruction v Mirena). Eligibility criteria for selecting studies Randomised controlled trials comparing hysterectomy, first and second generation endometrial destruction, and Mirena for women with heavy menstrual bleeding unresponsive to other medical treatment. RESULTS At around 12 months, more women were dissatisfied with outcome with first generation hysteroscopic techniques than with hysterectomy (13% v 5%; odds ratio 2.46, 95% confidence interval 1.54 to 3.9, P<0.001), but hospital stay (weighted mean difference 3.0 days, 2.9 to 3.1 days, P<0.001) and time to resumption of normal activities (5.2 days, 4.7 to 5.7 days, P<0.001) were longer for hysterectomy. Unsatisfactory outcomes were comparable with first and second generation techniques (odds ratio 1.2, 0.9 to 1.6, P=0.2), although second generation techniques were quicker (weighted mean difference 14.5 minutes, 13.7 to 15.3 minutes, P<0.001) and women recovered sooner (0.48 days, 0.20 to 0.75 days, P<0.001), with fewer procedural complications. Indirect comparison suggested more unsatisfactory outcomes with second generation techniques than with hysterectomy (11% v 5%; odds ratio 2.3, 1.3 to 4.2, P=0.006). Similar estimates were seen when Mirena was indirectly compared with hysterectomy (17% v 5%; odds ratio 2.2, 0.9 to 5.3, P=0.07), although this comparison lacked power because of the limited amount of data available for analysis. CONCLUSIONS More women are dissatisfied after endometrial destruction than after hysterectomy. Dissatisfaction rates are low after all treatments, and hysterectomy is associated with increased length of stay in hospital and a longer recovery period. Definitive evidence on effectiveness of Mirena compared with more invasive procedures is lacking.
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Golson M, Misfeldt AA, Kopsombut U, Petersen C, Gannon M. High Fat Diet Regulation of β-Cell Proliferation and β-Cell Mass. THE OPEN ENDOCRINOLOGY JOURNAL 2010; 4:10.2174/1874216501004010066. [PMID: 24339840 PMCID: PMC3856766 DOI: 10.2174/1874216501004010066] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Type 2 Diabetes (T2D) is characterized by relative insulin insufficiency, caused when peripheral tissues such as liver, muscle, and adipocytes have a decreased response to insulin. One factor that elevates the risk for insulin resistance and T2D is obesity. In obese patients without T2D and initially in people who develop T2D, pancreatic β-cells are able to compensate for insulin resistance by increasing β-cell mass, effected by increased proliferation and hypertrophy, as well as increased insulin secretion per β-cell. In patients that go on to develop T2D, however, this initial period of compensation is followed by β-cell failure due to decreased proliferation and increased apoptosis. The forkhead box transcription factor FoxM1 is required for β-cell replication in mice after four weeks of age, during pregnancy, and after partial pancreatectomy. We investigated whether it is also required for β-cell proliferation due to diet-induced obesity.
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Smith NJ, Gannon M. Political risk in light rail transit PPP projects. PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-MANAGEMENT PROCUREMENT AND LAW 2008. [DOI: 10.1680/mpal.2008.161.4.179] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Since 2003 public–private partnerships (PPPs) have represented between 10 and 13.5% of the total investment in public services in the UK. The macro-economic and political benefits of PPPs were among the key drivers for central government’s decision to promote this form of procurement to improve UK public services. Political support for a PPP project is critical and is frequently cited as the most important critical success factor. This paper investigates the significance of political support and reviews the treatment of political risk in a business case by the public sector project sponsor for major UK-based light rail transit PPP projects during their development stage. The investigation demonstrates that in the early project stages it is not traditional quantitative Monte Carlo risk analysis that is important; rather it is the identification and representation of political support within a business case together with an understanding of how this information is then used to inform critical project decisions.
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Tyono I, Trudeau ME, Matyas Y, Palmer S, Beattie K, Leung M, DeAngelis C, Charbonneau F, Gannon M. Improving the flow and scheduling of patients in the Systemic Treatment Program at the Odette Cancer Centre: Decreasing patients wait-times. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.20565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Gannon M. Briefing: Crossrail. PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-MANAGEMENT PROCUREMENT AND LAW 2008. [DOI: 10.1680/mpal.2008.161.2.45] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Crossrail, one of Europe’s largest infrastructure projects, received royal assent on 22nd July 2008. Construction of Crossrail is forecast to start in 2010 and become operational in 2017. This mega rail project is expected to provide a significant boost to the UK’s economy in terms of direct and indirect employment benefits. The scheme has taken nearly a decade to achieve this significant milestone having had its private bill rejected in the early 1990s. The UK’s central government has at long last provided ‘genuine’ political support and commitment to Crossrail, a critical factor during planning that is essential despite the scheme having a technically robust business case.
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Guruswamy S, Gannon M, Ryan M, Kinsella A, Breen EG, Kelly BD. Assessment of clinical and social need in patients attending an inner-city psychiatric service. Ir J Med Sci 2008; 177:177-8. [DOI: 10.1007/s11845-008-0155-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Accepted: 03/17/2008] [Indexed: 02/07/2023]
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Abbas M, Gannon M. The use of metformin as first line treatment in polycystic ovary syndrome. IRISH MEDICAL JOURNAL 2008; 101:51-53. [PMID: 18450250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This study evaluated the use of metformin as first line treatment for patients with polycystic ovary syndrome. A retrospective review of patients' files diagnosed with PCOS over 16 months in Department of obstetrics and gynaecology of a Regional hospital. The outcome was the response to metformin treatment regardless of the main complaint. Treatment response was measured by change in LH/FSH ratio, fasting insulin, testosterone, day 21 progesterone and/or pregnancy. A day 21 progesterone greater than 25.5 nmol/l and/or pregnancy were the parameter of ovulation. Thirty-four patients were diagnosed with PCOS. Twenty-five complained of infertility (14 primary and 11 secondary), six patients had oligomenorrhoea or amenorrhoea and three presented with hirsutism. Seventeen patients received metformin as first line treatment. Eight received it with other treatment (5 clomiphene citrate and 3 ant androgens). Nine patients did not receive metformin. This study justifies the use of metformin as an appropriate first line treatment for PCOS.
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Daniel M, Vaghela H, Philpott C, Thomas R, Gannon M, Spencer H, Haggard M. Does the benefit of adenoidectomy in addition to ventilation tube insertion persist long-term? Clin Otolaryngol 2006. [DOI: 10.1111/j.1365-2273.2006.01341_5.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lefurgey A, Gannon M, Blum J, Ingram P. Leishmania donovani amastigotes mobilize organic and inorganic osmolytes during regulatory volume decrease. J Eukaryot Microbiol 2005; 52:277-89. [PMID: 15927005 DOI: 10.1111/j.1550-7408.2005.00030.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The protozoan parasite Leishmania donovani encounters large fluctuations in osmolality as it cycles between its insect vector and human host. The flagellated promastigote exhibits regulatory volume responses involving organic and inorganic osmolytes, but little is known about volume regulation in the clinically relevant amastigote that multiplies within the parasitophorous vacuoles of mammalian host cells. Using a combination of morphological, X-ray microanalytical, and biochemical approaches we determined that non-motile amastigotes respond to hypotonic stress with (1) an amino acid and l-alanine-mediated regulatory volume decrease, and (2) a parallel release of Na+, K+, P (presumably as negatively charged phosphates), and subsequently Cl- from cytoplasm and the cell as a whole. In addition P, Zn2+, and subsequently Ca2+ increase in acidocalcisomes as Cl- content declines in this compartment. This evidence is the first to document subcellular translocation of, and thus a potential role for, zinc in volume regulatory responses. These coordinated changes in organic and inorganic osmolytes demonstrate that amastigote subcellular compartments, particularly acidocalcisomes, function in maintaining ionic homeostasis in the response of Leishmania amastigotes to hypo-osmotic stress.
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Gannon M, Gamer LW, Wright CV. Regulatory regions driving developmental and tissue-specific expression of the essential pancreatic gene pdx1. Dev Biol 2001; 238:185-201. [PMID: 11784003 DOI: 10.1006/dbio.2001.0359] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
pdx1 (pancreatic and duodenal homeobox gene-1), which is expressed broadly in the embryonic pancreas and, later, in a more restricted manner in the mature beta cells in the islets of Langerhans, is essential both for organ formation and beta cell gene expression and function. We carried out a transgenic reporter gene analysis to identify region- and cell type-specific regulatory regions in pdx1. A 14.5-kb pdx1 genomic fragment corrected the glucose intolerance of pdx1(+/-) animals but, moreover, fully rescued the severe gut and pancreas defects in pdx1(-/-) embryos. Sequences sufficient to direct reporter expression to the entire endogenous pdx1 expression domain lie within 4.3 kb of 5' flanking DNA. In this region, we identified two distinct fragments that drive reporter gene expression to different sets of islet neuroendocrine cells. One shows pan-endocrine cell specificity, the other is selectively activated in insulin-producing beta cells. The endocrine-specific regulatory regions overlap a localized region of 5' flanking DNA that is remarkably conserved in sequence between vertebrate pdx1 genes, and which has been associated with beta cell-selective expression in cultured cell lines. This region contains potential binding sites for several transcription factors implicated in endodermal development and the pathogenesis of some forms of type-2 diabetes. These results are consistent with our previous proposal that conserved upstream pdx1 sequences exert control over pdx1 during embryonic organogenesis and islet endocrine cell differentiation. We propose that mutations affecting the expression and/or activity of transcription factors operating via these sequences may predispose towards diabetes, at least in part by direct effects on endocrine pdx1 expression.
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Abstract
Transgenic and 'knockout' models are increasingly used to study the role of the immune system, insulin signaling and beta-cell gene transcription in diabetes. Mice and humans have similar genetics, developmental biology and physiology. In interpreting these models, however, one needs to be mindful of some differences that exist between mice and humans.
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Demark-Wahnefried W, Price DT, Polascik TJ, Robertson CN, Anderson EE, Paulson DF, Walther PJ, Gannon M, Vollmer RT. Pilot study of dietary fat restriction and flaxseed supplementation in men with prostate cancer before surgery: exploring the effects on hormonal levels, prostate-specific antigen, and histopathologic features. Urology 2001; 58:47-52. [PMID: 11445478 DOI: 10.1016/s0090-4295(01)01014-7] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Dietary fat and fiber affect hormonal levels and may influence cancer progression. Flaxseed is a rich source of lignan and omega-3 fatty acids and may thwart prostate cancer. The potential effects of flaxseed may be enhanced with concomitant fat restriction. We undertook a pilot study to explore whether a flaxseed-supplemented, fat-restricted diet could affect the biomarkers of prostatic neoplasia. METHODS Twenty-five patients with prostate cancer who were awaiting prostatectomy were instructed on a low-fat (20% of kilocalories or less), flaxseed-supplemented (30 g/day) diet. The baseline and follow-up levels of prostate-specific antigen, testosterone, free androgen index, and total serum cholesterol were determined. The tumors of diet-treated patients were compared with those of historic cases (matched by age, race, prostate-specific antigen level at diagnosis, and biopsy Gleason sum) with respect to apoptosis (terminal deoxynucleotidyl transferase [TdT]-mediated dUTP-biotin nick end-labeling [TUNEL]) and proliferation (MIB-1). RESULTS The average duration on the diet was 34 days (range 21 to 77), during which time significant decreases were observed in total serum cholesterol (201 +/- 39 mg/dL to 174 +/- 42 mg/dL), total testosterone (422 +/- 122 ng/dL to 360 +/- 128 ng/dL), and free androgen index (36.3% +/- 18.9% to 29.3% +/- 16.8%) (all P <0.05). The baseline and follow-up levels of prostate-specific antigen were 8.1 +/- 5.2 ng/mL and 8.5 +/- 7.7 ng/mL, respectively, for the entire sample (P = 0.58); however, among men with Gleason sums of 6 or less (n = 19), the PSA values were 7.1 +/- 3.9 ng/mL and 6.4 +/- 4.1 ng/mL (P = 0.10). The mean proliferation index was 7.4 +/- 7.8 for the historic controls versus 5.0 +/- 4.9 for the diet-treated patients (P = 0.05). The distribution of the apoptotic indexes differed significantly (P = 0.01) between groups, with most historic controls exhibiting TUNEL categorical scores of 0; diet-treated patients largely exhibited scores of 1. Both the proliferation rate and apoptosis were significantly associated with the number of days on the diet (P = 0.049 and P = 0.017, respectively). CONCLUSIONS These pilot data suggest that a flaxseed-supplemented, fat-restricted diet may affect prostate cancer biology and associated biomarkers. Further study is needed to determine the benefit of this dietary regimen as either a complementary or preventive therapy.
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Dutta S, Gannon M, Peers B, Wright C, Bonner-Weir S, Montminy M. PDX:PBX complexes are required for normal proliferation of pancreatic cells during development. Proc Natl Acad Sci U S A 2001; 98:1065-70. [PMID: 11158595 PMCID: PMC14709 DOI: 10.1073/pnas.98.3.1065] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2000] [Accepted: 11/22/2000] [Indexed: 11/18/2022] Open
Abstract
The homeobox factor PDX-1 is a key regulator of pancreatic morphogenesis and glucose homeostasis; targeted disruption of the PDX-1 gene leads to pancreatic agenesis in pdx-1(-/-) homozygotes. Pdx-1 heterozygotes develop normally, but they display glucose intolerance in adulthood. Like certain other homeobox proteins, PDX-1 contains a consensus FPWMK motif that promotes heterodimer formation with the ubiquitous homeodomain protein PBX. To evaluate the importance of PDX-1:PBX complexes in pancreatic morphogenesis and glucose homeostasis, we expressed either wild-type or PBX interaction defective PDX-1 transgenes under control of the PDX-1 promoter. Both wild-type and mutant PDX-1 transgenes corrected glucose intolerance in pdx-1 heterozygotes. The wild-type PDX-1 transgene rescued the development of all pancreatic lineages in pdx-1(-/-) animals, and these mice survived to adulthood. In contrast, pancreata from pdx-1(-/-) mice expressing the mutant PDX-1 transgene were hypoplastic, and these mice died within 3 weeks of birth from pancreatic insufficiency. All pancreatic cell types were observed in pdx-1(-/-) mice expressing the mutant PDX-1 transgene; but the islets were smaller, and increased numbers of islet hormone-positive cells were noted within the ductal epithelium. These results indicate that PDX-1:PBX complexes are dispensable for glucose homeostasis and for differentiation of stem cells into ductal, endocrine, and acinar lineages; but they are essential for expansion of these populations during development.
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Gannon M, Ray MK, Van Zee K, Rausa F, Costa RH, Wright CV. Persistent expression of HNF6 in islet endocrine cells causes disrupted islet architecture and loss of beta cell function. Development 2000; 127:2883-95. [PMID: 10851133 DOI: 10.1242/dev.127.13.2883] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We used transgenesis to explore the requirement for downregulation of hepatocyte nuclear factor 6 (HNF6) expression in the assembly, differentiation, and function of pancreatic islets. In vivo, HNF6 expression becomes downregulated in pancreatic endocrine cells at 18. 5 days post coitum (d.p.c.), when definitive islets first begin to organize. We used an islet-specific regulatory element (pdx1(PB)) from pancreatic/duodenal homeobox (pdx1) gene to maintain HNF6 expression in endocrine cells beyond 18.5 d.p.c. Transgenic animals were diabetic. HNF6-overexpressing islets were hyperplastic and remained very close to the pancreatic ducts. Strikingly, alpha, delta, and PP cells were increased in number and abnormally intermingled with islet beta cells. Although several mature beta cell markers were expressed in beta cells of transgenic islets, the glucose transporter GLUT2 was absent or severely reduced. As glucose uptake/metabolism is essential for insulin secretion, decreased GLUT2 may contribute to the etiology of diabetes in pdx1(PB)-HNF6 transgenics. Concordantly, blood insulin was not raised by glucose challenge, suggesting profound beta cell dysfunction. Thus, we have shown that HNF6 downregulation during islet ontogeny is critical to normal pancreas formation and function: continued expression impairs the clustering of endocrine cells and their separation from the ductal epithelium, disrupts the spatial organization of endocrine cell types within the islet, and severely compromises beta cell physiology, leading to overt diabetes.
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Gannon M, Gilday D, Rifkind AB. TCDD induces CYP1A4 and CYP1A5 in chick liver and kidney and only CYP1A4, an enzyme lacking arachidonic acid epoxygenase activity, in myocardium and vascular endothelium. Toxicol Appl Pharmacol 2000; 164:24-37. [PMID: 10739741 DOI: 10.1006/taap.1999.8864] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other Ah receptor ligands, species differences in sensitivity and the relationship of CYP1A induction to the toxicity, are poorly understood. Ah receptor ligands induce formation of CYP1A1 and 1A2 in mammals and of a different set of enzymes, CYP1A4 and 1A5, in chicks. We examined induction by TCDD of CYP1A4 and 1A5 mRNA and protein in chick embryo liver, heart, kidney, lung, intestine, bursa, spleen, thymus, brain, and muscle by in situ hybridization and immunohistochemistry and verified the histochemical findings by CYP-specific assays, 7-ethoxyresorufin deethylase for CYP1A4 and arachidonic acid epoxygenation for CYP1A5. CYP1A4 alone was extensively induced in the cardiovascular system, in cardiac myocytes, in perivascular cells having the same location as impulse-conducting Purkinje cells, and like CYP1A1, in vascular endothelium in every organ examined. Unlike mammalian CYP1A, CYP1A4 and 1A5 were both substantially induced in kidney proximal tubules as well as liver, and neither enzyme was induced in kidney glomeruli or lung or brain parenchymal cells. The findings demonstrate (a) a route for CYP1A4 to affect cardiac function, (b) that vascular endothelium is a major site of CYP1A induction across species, and (c) that CYP1A induced in heart or endothelial cells cannot affect cardiac or vascular function via generation of arachidonic acid epoxides because the CYP1A enzymes induced in those organs are not arachidonic acid epoxygenases. Further, the specificity of CYP1A induction sites and of the catalytically active enzymes induced at each site support a significant role for CYP1A induction in Ah receptor ligand toxicity and species differences in sensitivity.
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Gerrish K, Gannon M, Shih D, Henderson E, Stoffel M, Wright CV, Stein R. Pancreatic beta cell-specific transcription of the pdx-1 gene. The role of conserved upstream control regions and their hepatic nuclear factor 3beta sites. J Biol Chem 2000; 275:3485-92. [PMID: 10652343 DOI: 10.1074/jbc.275.5.3485] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
To identify potential transactivators of pdx-1, we sequenced approximately 4.5 kilobases of the 5' promoter region of the human and chicken homologs, assuming that sequences conserved with the mouse gene would contain critical cis-regulatory elements. The sequences associated with hypersensitive site 1 (HSS1) represented the principal area of homology within which three conserved subdomains were apparent: area I (-2694 to -2561 base pairs (bp)), area II (-2139 to -1958 bp), and area III (-1879 to -1799 bp). The identities between the mouse and chicken/human genes are very high, ranging from 78 to 89%, although only areas I and III are present within this region in chicken. Pancreatic beta cell-selective expression was shown to be controlled by mouse and human area I or area II, but not area III, from an analysis of pdx-1-driven reporter activity in transfected beta- and non-beta cells. Mutational and functional analyses of conserved hepatic nuclear factor 3 (HNF3)-like sites located within area I and area II demonstrated that activation by these regions was mediated by HNF3beta. To determine if a similar regulatory relationship might exist within the context of the endogenous gene, pdx-1 expression was measured in embryonic stem cells in which one or both alleles of HNF3beta were inactivated. pdx-1 mRNA levels induced upon differentiation to embryoid bodies were down-regulated in homozygous null HNF3beta cells. Together, these results suggest that the conserved sequences represented by areas I and II define the binding sites for factors such as HNF3beta, which control islet beta cell-selective expression of the pdx-1 gene.
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Gannon M, Shiota C, Postic C, Wright CV, Magnuson M. Analysis of the Cre-mediated recombination driven by rat insulin promoter in embryonic and adult mouse pancreas. Genesis 2000; 26:139-42. [PMID: 10686610 DOI: 10.1002/(sici)1526-968x(200002)26:2<139::aid-gene12>3.0.co;2-7] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Haggard M, Gannon M. A rational strategy for the treatment of glue ear. THE PRACTITIONER 2000; 244:106, 109-11. [PMID: 10892043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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Song SY, Gannon M, Washington MK, Scoggins CR, Meszoely IM, Goldenring JR, Marino CR, Sandgren EP, Coffey RJ, Wright CV, Leach SD. Expansion of Pdx1-expressing pancreatic epithelium and islet neogenesis in transgenic mice overexpressing transforming growth factor alpha. Gastroenterology 1999; 117:1416-26. [PMID: 10579983 DOI: 10.1016/s0016-5085(99)70292-1] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS The progenitor cells responsible for transforming growth factor (TGF)-alpha-induced pancreatic ductal metaplasia and neoplasia remain uncharacterized. During pancreatic development, differentiated cell types arise from ductal progenitor cells expressing the Pdx1 homeodomain transcription factor. The aims of this study were, first, to evaluate the role of Pdx1-expressing stem cells in MT-TGFalpha transgenic mice, and second, to further characterize cell proliferation and differentiation in this model. METHODS To assess Pdx1 gene expression in normal and metaplastic epithelium, we performed in vivo reporter gene analysis using heterozygous Pdx1(lacZ/+) and bigenic Pdx1(lacZ/+)/MT-TGFalpha mice. RESULTS Pdx1(lacZ/+)/MT-TGFalpha bigenics showed up-regulated Pdx1 expression in premalignant metaplastic ductal epithelium. In addition to Pdx1 gene activation, TGF-alpha-induced metaplastic epithelium demonstrated a pluripotent differentiation capacity, as evidenced by focal expression of Pax6 and initiation of islet cell neogenesis. The majority of Pdx1-positive epithelial cells showed no expression of insulin, similar to the pattern observed during embryonic development. CONCLUSIONS Overexpression of TGF-alpha induces expansion of a Pdx1-expressing epithelium characterized by focal expression of Pax6 and initiation of islet neogenesis. These findings suggest that premalignant events induced by TGF-alpha in mouse pancreas may recapitulate a developmental program active during embryogenesis.
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Dixon S, Deverill M, Gannon M, Brazier J, Haggard M. Improving the validity of economic evaluations alongside controlled trials. J Health Serv Res Policy 1999; 4:161-3. [PMID: 10538881 DOI: 10.1177/135581969900400307] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Gannon M, Bader D. Avian cardiac progenitors: methods for isolation, culture, and analysis of differentiation. Methods Cell Biol 1997; 52:117-32. [PMID: 9379947 DOI: 10.1016/s0091-679x(08)60376-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Wu KL, Gannon M, Peshavaria M, Offield MF, Henderson E, Ray M, Marks A, Gamer LW, Wright CV, Stein R. Hepatocyte nuclear factor 3beta is involved in pancreatic beta-cell-specific transcription of the pdx-1 gene. Mol Cell Biol 1997; 17:6002-13. [PMID: 9315659 PMCID: PMC232449 DOI: 10.1128/mcb.17.10.6002] [Citation(s) in RCA: 214] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The mammalian homeobox gene pdx-1 is expressed in pluripotent precursor cells in the dorsal and ventral pancreatic bud and duodenal endoderm, which will produce the pancreas and the rostral duodenum. In the adult, pdr-1 is expressed principally within insulin-secreting pancreatic islet beta cells and cells of the duodenal epithelium. Our objective in this study was to localize sequences within the mouse pdx-1 gene mediating selective expression within the islet. Studies of transgenic mice in which a genomic fragment of the mouse pdx-1 gene from kb -4.5 to +8.2 was used to drive a beta-galactosidase reporter showed that the control sequences sufficient for appropriate developmental and adult specific expression were contained within this region. Three nuclease-hypersensitive sites, located between bp -2560 and -1880 (site 1), bp -1330 and -800 (site 2), and bp -260 and +180 (site 3), were identified within the 5'-flanking region of the endogenous pdx-1 gene. Pancreatic beta-cell-specific expression was shown to be controlled by sequences within site 1 from an analysis of the expression pattern of various pdr-1-herpes simplex virus thymidine kinase promoter expression constructs in transfected beta-cell and non-beta-cell lines. Furthermore, we also established that this region was important in vivo by demonstrating that expression from a site 1-driven beta-galactosidase reporter construct was directed to islet beta-cells in transgenic mice. The activity of the site 1-driven constructs was reduced substantially in beta-cell lines by mutating a hepatocyte nuclear factor 3 (HNF3)-like site located between nucleotides -2007 and -1996. Gel shift analysis indicated that HNF3beta present in islet beta cells binds to this element. Immunohistochemical studies revealed that HNF3beta was present within the nuclei of almost all islet beta cells and subsets of pancreatic acinar cells. Together, these results suggest that HNF3beta, a key regulator of endodermal cell lineage development, plays an essential role in the cell-type-specific transcription of the pdx-1 gene in the pancreas.
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Gibbons P, Gannon M, Wrigley M. A study of aggression among referrals to a community-based psychiatry of old age service. Int J Geriatr Psychiatry 1997; 12:384-8. [PMID: 9152725] [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: 02/04/2023]
Abstract
OBJECTIVE The aims of the study were to examine the prevalence of aggressive behaviour in a non-selected community-based population, to identify clinical and sociodemographic variables associated with aggression and to examine the relationship between aggression and outcome at 2-year follow-up. DESIGN Case series, using the Ryden Aggression Scale as a retrospective measure of aggression. SETTING A community-based specialist psychiatry of old age service. PARTICIPANTS All referrals to the service over a 3-month period. RESULTS Of the 42 subjects included in the study, 25-patients had a diagnosis of dementia. Aggressive behaviour was reported in 18 patients, this being verbal only in nine cases and both verbal and physical in nine cases. Sexual aggression and self-injurious behaviour were each reported in one case only. Aggression was found to be positively associated with a diagnosis of dementia and high physical dependency but was not found to be associated with age, sex, physical illness or the use of psychotropic medication. At 2-year follow-up, aggressive patients were found to have a higher rate of admission to psychiatric inpatient or residential care and tended to have a higher use of neuroleptic drugs. CONCLUSIONS These findings suggest that aggression is a significant problem for community-based elderly people and their carers, may increase the likelihood of admission into long-term care and that a reliable instrument to measure aggression would be useful in the clinical assessment of this population.
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Gilday D, Gannon M, Yutzey K, Bader D, Rifkind AB. Molecular cloning and expression of two novel avian cytochrome P450 1A enzymes induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin. J Biol Chem 1996; 271:33054-9. [PMID: 8955152 DOI: 10.1074/jbc.271.51.33054] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Transcriptional regulation by the aryl hydrocarbon receptor, for which the environmental toxin 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is the most potent ligand, leads in mammalian liver to the induction of genes for two distinct cytochrome P450 (CYP)1A enzymes, CYP1A1 and -1A2. Fish seem to have only one CYP1A enzyme. CYP1A enzymes have been regarded as injurious largely because of their ability to activate chemical carcinogens. We report here the cloning and sequencing of cDNAs for two catalytically distinct TCDD-induced CYP enzymes in chick embryo liver. One mediates classic CYP1A1 activities. The other has some -1A2-like activities and is also responsible for TCDD-induced arachidonic acid epoxygenation, a much more conspicuous effect in liver of chicks than of mammalian species. Amino acid sequence analysis shows that although each chick enzyme can be classified in the CYP1A family, both are more like CYP1A1 than -1A2, and neither can be said to be directly orthologous to CYP1A1 or -1A2. Phylogenetic analysis shows that the two chick enzymes form a separate branch in the CYP1A family tree distinct from mammalian CYP1A1 and -1A2 and from fish CYP1A enzymes. The findings suggest that CYP1A progenitors split into two CYP enzymes with some parallel functions independently in two evolutionary lines, evidence for convergent evolution in the CYP1A family. Northern analysis shows that the chick enzymes have a different tissue distribution from CYP1A1 and -1A2. Polymerase chain reaction and in situ hybridization data show that both chick enzymes are expressed in response to TCDD even before organ morphogenesis. The findings further suggest that beyond their role in activating carcinogens, CYP1A enzymes have conferred evolutionary and developmental advantages, perhaps as defenses in maintaining homeostatic responses to toxic chemicals.
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