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Kovacic JC, Muller D. Hypertrophic cardiomyopathy: state-of-the-art review, with focus on the management of outflow obstruction. Intern Med J 2003; 33:521-9. [PMID: 14656256 DOI: 10.1046/j.1445-5994.2003.00475.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Significant advances in our understanding and management of hypertrophic cardiomyopathy have been made in the last decade, as the complex genetics and phenotype-genotype correlations that characterize the disease are gradually unravelled. The well-described clinical heterogeneity of hypertrophic cardiomyopathy is now understood to be based on profound genetic variability, with at least 10 genes and over 150 mutations implicated. Several new therapeutic tools have entered clinical practice. The implantable cardioverter-defibrillator is now strongly indicated in those at high risk of sudden arrhythmic death. Our ability to abort sudden death in this subgroup has placed added emphasis on risk stratification in newly diagnosed patients. New procedures have also been developed for the relief of outflow obstruction in patients with refractory symptoms and a significant subaortic outflow gradient. Although not as efficacious as the 'gold-standard' surgical myectomy-myotomy, dual-chamber pacemaker implantation can be of modest benefit in select patients. Percutaneous transluminal septal myocardial ablation is an emerging catheter-based procedure for the relief of left ventricular outflow obstruction. Long-term follow-up data are still awaited. However, intermediate-term results suggest equivalent efficacy to surgical myectomy-myotomy.
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Abe K, Abe K, Abe T, Adam I, Akimoto H, Aston D, Baird KG, Baltay C, Band HR, Barklow TL, Bauer JM, Bellodi G, Berger R, Blaylock G, Bogart JR, Bower GR, Brau JE, Breidenbach M, Bugg WM, Burke D, Burnett TH, Burrows PN, Calcaterra A, Cassell R, Chou A, Cohn HO, Coller JA, Convery MR, Cook V, Cowan RF, Crawford G, Damerell CJS, Daoudi M, de Groot N, de Sangro R, Dong DN, Doser M, Dubois R, Erofeeva I, Eschenburg V, Fahey S, Falciai D, Fernandez JP, Flood K, Frey R, Hart EL, Hasuko K, Hertzbach SS, Huffer ME, Huynh X, Iwasaki M, Jackson DJ, Jacques P, Jaros JA, Jiang ZY, Johnson AS, Johnson JR, Kajikawa R, Kalelkar M, Kang HJ, Kofler RR, Kroeger RS, Langston M, Leith DWG, Lia V, Lin C, Mancinelli G, Manly S, Mantovani G, Markiewicz TW, Maruyama T, McKemey AK, Messner R, Moffeit KC, Moore TB, Morii M, Muller D, Murzin V, Narita S, Nauenberg U, Neal H, Nesom G, Oishi N, Onoprienko D, Osborne LS, Panvini RS, Park CH, Peruzzi I, Piccolo M, Piemontese L, Plano RJ, Prepost R, Prescott CY, Ratcliff BN, Reidy J, Reinertsen PL, Rochester LS, Rowson PC, Russell JJ, Saxton OH, Schalk T, Schumm BA, Schwiening J, Serbo VV, Shapiro G, Sinev NB, Snyder JA, Staengle H, Stahl A, Stamer P, Steiner H, Su D, Suekane F, Sugiyama A, Suzuki S, Swartz M, Taylor FE, Thom J, Torrence E, Usher T, Va'vra J, Verdier R, Wagner DL, Waite AP, Walston S, Weidemann AW, Weiss ER, Whitaker JS, Williams SH, Willocq S, Wilson RJ, Wisniewski WJ, Wittlin JL, Woods M, Wright TR, Yamamoto RK, Yashima J, Yellin SJ, Young CC, Yuta H. Improved direct measurement of the parity-violation parameter Ab using a mass tag and momentum-weighted track charge. PHYSICAL REVIEW LETTERS 2003; 90:141804. [PMID: 12731908 DOI: 10.1103/physrevlett.90.141804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2002] [Indexed: 05/24/2023]
Abstract
We present an improved direct measurement of the parity-violation parameter A(b) in the Z boson-b-quark coupling using a self-calibrating track-charge technique applied to a sample enriched in Z-->bb events via the topological reconstruction of the B hadron mass. Manipulation of the Stanford Linear Collider electron-beam polarization permits the measurement of A(b) to be made independently of other Z-pole coupling parameters. From the 1996-1998 sample of 400,000 hadronic Z decays, produced with an average beam polarization of 73.4%, we find A(b)=0.906+/-0.022(stat)+/-0.023(syst).
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Nogueira CW, Soares FA, Nascimento PC, Muller D, Rocha JBT. 2,3-Dimercaptopropane-1-sulfonic acid and meso-2,3-dimercaptosuccinic acid increase mercury- and cadmium-induced inhibition of delta-aminolevulinate dehydratase. Toxicology 2003; 184:85-95. [PMID: 12499112 DOI: 10.1016/s0300-483x(02)00575-9] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Compounds derived from Dimercaprol, such as meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercaptopropane-1-sulfonic acid (DMPS), are becoming common agents for treating humans exposed to heavy metals. Heavy metals such as Pb(2+), Hg(2+) and Cd(2+) can inhibit delta-aminolevulinate dehydratase (delta-ALA-D) activity. Delta-ALA-D catalyzes the condensation of two delta-aminolevulinic acid (delta-ALA) molecules with the formation of porphobilinogen, a heme precursor. The effects of DMSA and DMPS alone or in combination with Cd(2+), Hg(2+), or Pb(2+) on hepatic delta-ALA-D were examined. DMPS and DMSA caused a dose-dependent inhibition of hepatic delta-ALA-D. In the presence of Hg(2+) or Cd(2+) the inhibitory potency of DMPS increased. Similarly, the inhibitory effects of Hg(2+) and Cd(2+) were markedly increased in the presence of DMSA. In contrast, the inhibitory effect of DMPS was not changed by inclusion of Pb(2+). As observed with DMSA, Zn(2+) did not modified the inhibitory effect of DMPS. Data of the present report support the idea that the complexes formed (metals-DMSA or DMPS) were more inhibitory than the metal (Hg(2+) and Cd(2+)) or the chelating agent alone to the hepatic delta-ALA-D activity, in vitro. The mechanism of hepatic delta-ALA-D inhibition by Hg(2+)-DMPS/DMSA and Cd(2+)-DMPS/DMSA complexes involve the essential thiol groups of the enzyme.
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Houpert P, Muller D, Chazel V, Claraz M, Paquet F. Effect of DTPA on the nephrotoxicity induced by uranium in the rat. RADIATION PROTECTION DOSIMETRY 2003; 105:517-520. [PMID: 14527021 DOI: 10.1093/oxfordjournals.rpd.a006295] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The only treatment proposed after human contamination with MOX (mixed oxide of uranium and plutonium) is diethylenetriaminepentaacetic acid (DTPA), because plutonium is considered to be the major risk. However, both DTPA and uranium are nephrotoxic at high dosages and DTPA has been shown to increase in vitro the cytotoxicity induced by uranium on cultured epithelial tubular cells. This work aimed to test this effect in vivo. Rats were injected with subtoxic (57 microg kg(-1)) to toxic (639 microg kg(-1)) amounts of uranium as nitrate at 0 h, they received two DTPA injections (30 micromol kg(-1)) at 2 min and 24 h and were euthanased at 48 h. The nephrotoxic effects were evaluated by measurement of the body weight gain, food and water intake, measurement of biochemical parameters in urine and blood, and histological examination of one kidney. The main result was that DTPA did not increase the nephrotoxicity induced by uranium in the range of concentrations tested, which was inconsistent with the in vitro results.
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Griffin JL, Muller D, Woograsingh R, Jowatt V, Hindmarsh A, Nicholson JK, Martin JE. Vitamin E deficiency and metabolic deficits in neuronal ceroid lipofuscinosis described by bioinformatics. Physiol Genomics 2002; 11:195-203. [PMID: 12388797 DOI: 10.1152/physiolgenomics.00100.2002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mnd mouse, a model of neuronal ceroid lipofusinosis (NCL), has a profound vitamin E deficiency in sera and brain, associated with cerebral deterioration characteristic of NCL. In this study, the vitamin E deficiency is corrected using dietary supplementation. However, the histopathological features associated with NCL remained. With use of a bioinformatics approach based on high-resolution solid and solution state 1H-NMR spectroscopy and principal component analysis (PCA), the deficits associated with NCL are defined in terms of a metabolic phenotype. Although vitamin E supplementation reversed some of the metabolic abnormalities, in particular the concentration of phenylalanine in extracts of cerebral tissue, PCA demonstrated that metabolic deficits associated with NCL were greater than any effects produced from vitamin E supplementation. These deficits included increased glutamate and N-acetyl-L-aspartate and decreased creatine and glutamine concentrations in aqueous extracts of the cortex, as well as profound accumulation of lipid in intact cerebral tissue. This is discussed in terms of faulty production of mitochondrial-associated membranes, thought to be central to the deficits in mnd mice.
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Tassonyi E, Fathi M, Hughes GJ, Chiodini F, Bertrand D, Muller D, Fuchs-Buder T. Cerebrospinal fluid concentrations of atracurium, laudanosine and vecuronium following clinical subarachnoid hemorrhage. Acta Anaesthesiol Scand 2002; 46:1236-41. [PMID: 12421196 DOI: 10.1034/j.1399-6576.2002.461011.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Neuromuscular blocking agents may exert central nervous system effects when they reach the brain. This study assessed the concentrations and the time course of passage of vecuronium, atracurium, and its metabolite laudanosine in the cerebrospinal fluid (CSF) of patients undergoing intracranial aneurysm clipping. METHODS Twenty-five patients with subarachnoid hemorrhage were randomly allocated to receive an intravenous infusion of vecuronium (n=13) or atracurium (n=12). Arterial blood and lumbar CSF were sampled before and 1, 2, 3, 4 and 8 h after the start of the relaxant infusion. The samples were analyzed by liquid chromatography-electrospray ionization mass spectrometry (vecuronium) and high-pressure liquid chromatography (atracurium and laudanosine). RESULTS The data of 20 patients (10 in both groups) were analyzed. In 11 CSF samples from five patients atracurium was detected in concentrations from 10 to 50 ng/ml. Laudanosine was retrieved in all CSF samples at 1, 2, 3, 4 and 8 h; the highest CSF concentration of laudanosine occurred at 3 h [38 (18-63) ng/ml: median (range)]. Vecuronium was not found in any CSF sample. CONCLUSION Significant concentrations of atracurium and laudanosine but not of vecuronium were detected in the CSF of patients during and immediately after intracranial aneurysm surgery.
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Hulo S, Alberi S, Laux T, Muller D, Caroni P. A point mutant of GAP-43 induces enhanced short-term and long-term hippocampal plasticity. Eur J Neurosci 2002. [DOI: 10.1046/j.1460-9568.2002.1671406.x] [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]
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133
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Kiss JZ, Muller D. Contribution of the neural cell adhesion molecule to neuronal and synaptic plasticity. Rev Neurosci 2002; 12:297-310. [PMID: 11783716 DOI: 10.1515/revneuro.2001.12.4.297] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The neural cell adhesion molecule (NCAM) and its polysialylated form PSA-NCAM contribute to many aspects of the development and plasticity of the central nervous system. This includes mechanisms of cell differentiation and migration, neurite outgrowth, establishment of specific patterns of synaptic connections, synaptic plasticity and long-term potentiation. How NCAM and PSA-NCAM contribute to regulate all these different mechanisms remains essentially unknown. Adhesive properties appear to be important, but recent studies also point to possible interactions between NCAM and PSA-NCAM with intracellular signalling cascades that are essential to biological functions. Some of these mechanisms are discussed and a hypothesis is proposed based on the existence of cross-talk between these molecules and signalling pathways mediated by growth factors.
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Hulo S, Alberi S, Laux T, Muller D, Caroni P. A point mutant of GAP-43 induces enhanced short-term and long-term hippocampal plasticity. Eur J Neurosci 2002; 15:1976-82. [PMID: 12099903 DOI: 10.1046/j.1460-9568.2002.02026.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The growth-associated protein GAP-43 (or neuromodulin or B-50) plays a critical role during development in mechanisms of axonal growth and formation of synaptic networks. At later times, GAP-43 has also been implicated in the regulation of synaptic transmission and properties of plasticity such as long-term potentiation. In a molecular approach, we have analyzed transgenic mice overexpressing different mutated forms of GAP-43 or deficient in GAP-43 to investigate the role of the molecule in short-term and long-term plasticity. We report that overexpression of a mutated form of GAP-43 that mimics constitutively phosphorylated GAP-43 results in an enhancement of long-term potentiation in CA1 hippocampal slices. This effect is specific, because LTP was affected neither in transgenic mice overexpressing mutated forms of non-phosphorylatable GAP-43 nor in GAP-43 deficient mice. The increased LTP observed in transgenic mice expressing a constitutively phosphorylated GAP-43 was associated with an increased paired-pulse facilitation as well as an increased summation of responses during high frequency bursts. These results indicate that, while GAP-43 is not necessary for LTP induction, its phosphorylation may regulate presynaptic properties, thereby affecting synaptic plasticity and the induction of LTP.
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Abe K, Abe K, Abe T, Adam I, Akimoto H, Aston D, Baird KG, Baltay C, Band HR, Barklow TL, Bauer JM, Bellodi G, Berger R, Blaylock G, Bogart JR, Bower GR, Brau JE, Breidenbach M, Bugg WM, Burke D, Burnett TH, Burrows PN, Calcaterra A, Cassell R, Chou A, Cohn HO, Coller JA, Convery MR, Cook V, Cowan RF, Crawford G, Damerell CJS, Daoudi M, de Groot N, de Sangro R, Dong DN, Doser M, Dubois R, Erofeeva I, Eschenburg V, Fahey S, Falciai D, Fernandez JP, Flood K, Frey R, Hart EL, Hasuko K, Hertzbach SS, Huffer ME, Huynh X, Iwasaki M, Jackson DJ, Jacques P, Jaros JA, Jiang ZY, Johnson AS, Johnson JR, Kajikawa R, Kalelkar M, Kang HJ, Kofler RR, Kroeger RS, Langston M, Leith DWG, Lia V, Lin C, Mancinelli G, Manly S, Mantovani G, Markiewicz TW, Maruyama T, McKemey AK, Messner R, Moffeit KC, Moore TB, Morii M, Muller D, Murzin V, Narita S, Nauenberg U, Neal H, Nesom G, Oishi N, Onoprienko D, Osborne LS, Panvini RS, Park CH, Peruzzi I, Piccolo M, Piemontese L, Plano RJ, Prepost R, Prescott CY, Ratcliff BN, Reidy J, Reinertsen PL, Rochester LS, Rowson PC, Russell JJ, Saxton OH, Schalk T, Schumm BA, Schwiening J, Serbo VV, Shapiro G, Sinev NB, Snyder JA, Staengle H, Stahl A, Stamer P, Steiner H, Su D, Suekane F, Sugiyama A, Suzuki S, Swartz M, Taylor FE, Thom J, Torrence E, Usher T, Va'vra J, Verdier R, Wagner DL, Waite AP, Walston S, Weidemann AW, Weiss ER, Whitaker JS, Williams SH, Willocq S, Wilson RJ, Wisniewski WJ, Wittlin JL, Woods M, Wright TR, Yamamoto RK, Yashima J, Yellin SJ, Young CC, Yuta H. Improved direct measurement of A(b) and A(c) at the Z(0) pole using a lepton tag. PHYSICAL REVIEW LETTERS 2002; 88:151801. [PMID: 11955189 DOI: 10.1103/physrevlett.88.151801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2001] [Indexed: 05/23/2023]
Abstract
The parity violation parameters A(b) and A(c) of the Zb(b) and Zc(c) couplings have been measured directly, using the polar angle dependence of the polarized cross sections at the Z(0) pole. Bottom and charmed hadrons were tagged via their semileptonic decays. Both the electron and muon analyses take advantage of new multivariate techniques to increase the analyzing power. Based on the 1993-1998 SLD sample of 550,000 Z(0) decays produced with highly polarized electron beams, we measure A(b) = 0.919+/-0.030(stat)+/-0.024(syst), and A(c) = 0.583+/-0.055(stat)+/-0.055(syst).
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Boda B, Mas C, Muller D. Activity-dependent regulation of genes implicated in X-linked non-specific mental retardation. Neuroscience 2002; 114:13-7. [PMID: 12207950 DOI: 10.1016/s0306-4522(02)00218-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
X-linked forms of non-specific mental retardation are complex disorders, for which mutations in several genes have recently been identified. These include OPHN1, GDI1, PAK3, IL1RAPL, TM4SF2, FMR2 and RSK2. To investigate the mechanisms through which alterations of these gene products could result in cognitive impairment, we analyzed their expression using quantitative PCR technique in two in vitro models of activity-dependent gene regulation: kainate-induced seizures and long-term synaptic potentiation (LTP). We found that the level of expression of four genes, PAK3, IL1RAPL, RSK2 and TM4SF2, was significantly up-regulated following kainate treatment. Furthermore we observed a significant increase in mRNA levels of PAK3 and IL1RAPL following LTP induction. These results suggest a possible role for these four genes in activity-dependent brain plasticity.
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Brooks JD, Metter EJ, Chan DW, Sokoll LJ, Landis P, Nelson WG, Muller D, Andres R, Carter HB. Plasma selenium level before diagnosis and the risk of prostate cancer development. J Urol 2001. [PMID: 11696701 DOI: 10.1016/s0022-5347(05)65500-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Epidemiological studies and a randomized intervention trial suggest that the risk of prostate cancer may be reduced by selenium intake. We investigated whether plasma selenium level before diagnosis correlated with the risk of later developing prostate cancer. MATERIALS AND METHODS A case control study was performed on men from the Baltimore Longitudinal Study of Aging registry, including 52 with known prostate cancer and 96 age matched controls with no detectable prostatic disease. Plasma selenium was measured at an average time plus or minus standard deviation of 3.83 +/- 1.85 years before the diagnosis of prostate cancer by graphite furnace atomic absorption spectrophotometry. Adjusted odds ratio and 95% confidence interval were computed with logistic regression. RESULTS After correcting for years before diagnosis, body mass index, and smoking and alcohol use history, higher selenium was associated with a lower risk of prostate cancer. Compared with the lowest quartile of selenium (range 8.2 to 10.7 microg./dl.), the odds ratios of the second (10.8 to 11.8), third (11.9 to 13.2) and fourth (13.3 to 18.2) quartiles were 0.15 (95% confidence interval 0.05 to 0.50), 0.21 (0.07 to 0.68) and 0.24 (0.08 to 0.77, respectively, p =0.01). Furthermore, plasma selenium decreased significantly with patient age (p <0.001). CONCLUSIONS Low plasma selenium is associated with a 4 to 5-fold increased risk of prostate cancer. These results support the hypothesis that supplemental selenium may reduce the risk of prostate cancer. Because plasma selenium decreases with patient age, supplementation may be particularly beneficial to older men.
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Hoenderop JGJ, Vennekens R, Muller D, Prenen J, Droogmans G, Bindels RJM, Nilius B. Function and expression of the epithelial Ca2+ channel family: comparison of mammalian ECaC1 and 2. J Physiol 2001. [DOI: 10.1113/jphysiol.2001.012917] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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139
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Brooks JD, Metter EJ, Chan DW, Sokoll LJ, Landis P, Nelson WG, Muller D, Andres R, Carter HB. Plasma selenium level before diagnosis and the risk of prostate cancer development. J Urol 2001; 166:2034-8. [PMID: 11696701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
PURPOSE Epidemiological studies and a randomized intervention trial suggest that the risk of prostate cancer may be reduced by selenium intake. We investigated whether plasma selenium level before diagnosis correlated with the risk of later developing prostate cancer. MATERIALS AND METHODS A case control study was performed on men from the Baltimore Longitudinal Study of Aging registry, including 52 with known prostate cancer and 96 age matched controls with no detectable prostatic disease. Plasma selenium was measured at an average time plus or minus standard deviation of 3.83 +/- 1.85 years before the diagnosis of prostate cancer by graphite furnace atomic absorption spectrophotometry. Adjusted odds ratio and 95% confidence interval were computed with logistic regression. RESULTS After correcting for years before diagnosis, body mass index, and smoking and alcohol use history, higher selenium was associated with a lower risk of prostate cancer. Compared with the lowest quartile of selenium (range 8.2 to 10.7 microg./dl.), the odds ratios of the second (10.8 to 11.8), third (11.9 to 13.2) and fourth (13.3 to 18.2) quartiles were 0.15 (95% confidence interval 0.05 to 0.50), 0.21 (0.07 to 0.68) and 0.24 (0.08 to 0.77, respectively, p =0.01). Furthermore, plasma selenium decreased significantly with patient age (p <0.001). CONCLUSIONS Low plasma selenium is associated with a 4 to 5-fold increased risk of prostate cancer. These results support the hypothesis that supplemental selenium may reduce the risk of prostate cancer. Because plasma selenium decreases with patient age, supplementation may be particularly beneficial to older men.
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Millon R, Muller D, Schultz I, Salvi R, Ghnassia JP, Frebourg T, Wasylyk B, Abecassis J. Loss of MDM2 expression in human head and neck squamous cell carcinomas and clinical significance. Oral Oncol 2001; 37:620-31. [PMID: 11590071 DOI: 10.1016/s1368-8375(00)00122-6] [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: 11/17/2022]
Abstract
The transforming potential of the MDM2 oncogene has been attributed to the overproduction of the protein. In order to investigate regulation of MDM2 expression in head and neck squamous cell carcinomas, we analysed MDM2 gene amplification, and mRNA and protein expression in tumour specimens from 62 patients, in cell lines, and in normal epithelium adjacent to tumours or obtained from healthy patients. Additionally, TP53-induced MDM2-P2 transcription was evaluated and compared with TP53 status. MDM2 gene amplification and mRNA over-expression is infrequent, 7 and 9%, respectively. The predominant transcript codes for full-length MDM2 protein (90kD) and the level of alternatively spliced forms is not significant. We show that only 47% of tumours exhibit MDM2 immunostaining in more than one third of the neoplastic cells, and thus more than half of the tumours display no or low levels of MDM2 protein. In contrast, MDM2 protein is always detectable in basal and parabasal cells of morphologically normal epithelium outside the invasively growing tumour, as well as in a normal uvula sample. Similarly, the total amount of MDM2 transcripts analysed by reverse transcriptase-polymerase chain reaction is reduced in tumour samples compared to normal tissues, essentially due to a decrease in P2 transcript levels. The relationship between mutated p53 status and low levels of MDM2 found in cell lines is also observed to a certain extent in primary tumour samples. Overall, there is a high frequency of TP53 mutation and under-expression of MDM2 in the head and neck tumours. Moreover, a significant association of decreased MDM2 expression is observed with advanced tumour stage and 3 years survival.
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141
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Kiss JZ, Troncoso E, Djebbara Z, Vutskits L, Muller D. The role of neural cell adhesion molecules in plasticity and repair. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2001; 36:175-84. [PMID: 11690614 DOI: 10.1016/s0165-0173(01)00093-5] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Repair and functional recovery after brain injury critically depends on structural and functional plasticity of preserved neuronal networks. A striking feature of brain structures where tissue reorganization and plasticity occur is a strong expression of the polysialylated neural cell adhesion molecule (PSA-NCAM). An important role of this molecule in various aspects of neuronal and synaptic plasticity has been revealed by many studies. Recently, a new mechanism has been elucidated whereby PSA-NCAM may contribute to signalling mediated by the neurotrophic factor BDNF, thereby sensitizing neurons to this growth factor. This mechanism was shown to be important for activity-induced synaptic plasticity and for the survival and differentiation of cortical neurons. A cross-talk between these molecules may, thus, reveal a key factor for properties of structural plasticity and in particular could mediate the activity-dependent aspects of synaptic network remodeling. Animal models have been developed to assess the role of these molecules in functional recovery after lesions.
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Toni N, Buchs PA, Nikonenko I, Povilaitite P, Parisi L, Muller D. Remodeling of synaptic membranes after induction of long-term potentiation. J Neurosci 2001; 21:6245-51. [PMID: 11487647 PMCID: PMC6763190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Several morphological changes of synapses have been reported to be associated with the induction of long-term potentiation (LTP) in the CA1 hippocampus, including an transient increase in the proportion of synapses with perforated postsynaptic densities (PSDs) and a later occurrence of multiple spine boutons (MSBs) in which the two spines arise from the same dendrite. To investigate the functional significance of these modifications, we analyzed single sections and reconstructed 134 synapses labeled via activity using a calcium precipitation approach. Analyses of labeled spine profiles showed changes of the spine head area, PSD length, and proportion of spine profiles containing a coated vesicle that reflected variations in the relative proportion of different types of synapses. Three-dimensional reconstruction indicated that the increase of perforated spine profiles observed 30 min after LTP induction essentially resulted from synapses exhibiting segmented, completely partitioned PSDs. These synapses had spine head and PSD areas approximately three times larger than those of simple synapses. They contained coated vesicles in a much higher proportion than that of any other type of synapse and exhibited large spinules associated with the PSD. Also the MSBs with two spines arising from the same dendrite that were observed 1-2 hr after LTP induction included a spine that was smaller and a PSD that was smaller than those of simple synapses. These results support the idea that LTP induction is associated with an enhanced recycling of synaptic membrane and that this process could underlie the formation of synapses with segmented PSDs and eventually result in the formation of a new, immature spine.
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143
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Hulo S, Muller D. Tetrodotoxin-sensitive enhancement of inhibition in CA1 pyramidal neurones by nicotine. Neuroreport 2001; 12:1351-4. [PMID: 11388409 DOI: 10.1097/00001756-200105250-00012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Nicotine modulates excitatory and inhibitory transmission in the hippocampus by acting on receptors located on various cellular compartments. We report that nicotine, applied for 5-10 min at concentrations similar to those found during smoking (0.5-5 M), resulted in all CA1 pyramidal neurones in a marked, phasic and tonic increase in the frequency and amplitude of spontaneous inhibitory currents. This effect was fully prevented by pre-incubation with the sodium channel blocker tetrodotoxin and was partially inhibited by the two nicotinic receptor antagonists methyllicaconitine (MLA) and dihydro-beta-erythroidine (DHbetaE). We conclude that, under conditions found during smoking, nicotine enhances inhibitory transmission, an effect exclusively mediated through an enhancement of the firing rate of interneurones, without changes in spontaneous quantal release of GABA.
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Redon R, Muller D, Caulee K, Wanherdrick K, Abecassis J, du Manoir S. A simple specific pattern of chromosomal aberrations at early stages of head and neck squamous cell carcinomas: PIK3CA but not p63 gene as a likely target of 3q26-qter gains. Cancer Res 2001; 61:4122-9. [PMID: 11358835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Low-grade head and neck squamous cell carcinomas without lymph node involvement or distant metastasis (N(0)M(0)) were screened for chromosomal imbalances by comparative genomic hybridization (CGH). pT(1-2) tumors contain a low number of aberrations (average number, 4.3; 15 cases), in contrast to pT(3) tumors (average number, 11.8; 6 cases), and exhibit a specific CGH pattern, affecting three chromosomes: partial or total 3q gain and/or 3p loss (73% of cases), 8q gain (47%), and 11q13 gain (27%). Thus, these changes represent early events in the pathogenesis of low-grade tumors. Cytogenetic exploration of chromosome 3 aberrations in head and neck cell lines suggests that the formation of an isochromosome 3q is one intermediate mechanism leading to 3p losses and/or 3q gains. On the long arm of chromosome 3, most of tumors exhibit low-level gains of large segments, involving systematically the 3q26-qter area, but with two alternative smallest region overlaps at 3q26 and 3q28-qter. We decided to refine the mapping of 3q26-qter gains by using fluorescence in situ hybridization on tumor nuclei, with clones containing two outstanding positional and functional candidate genes, PIK3CA and p63, located respectively at 3q26 and at 3q28. Although PIK3CA or p63 were preferentially gained in few cases (4 of 45), both genes were over-represented in 27 of 45 low-grade N(0)M(0) carcinomas analyzed by CGH or fluorescence in situ hybridization. To evaluate the relative contribution of PIK3CA and p63 in the pathogenesis of head and neck carcinomas displaying a 3q gain, we measured their respective transcription levels in tumors with previously determined gene copy number. DNp63, the predominant p63 transcript, is overexpressed in tumors compared with normal tissues, but its expression level is independent to gene copy number. In contrast, a significant PIK3CA overexpression is associated with increased gene dosage. These results indicate that PIK3CA, contrary to DNp63, may participate to the progression of head and neck tumors consequent to a low-level 3q over-representation. Interestingly, survival analysis using CGH suggested, in accordance with previous data, that 3q26 gain, the locus of PIK3CA, could predict clinical outcome for early disease tumors. This prompts us to pursue 3q26 (or PIK3CA) prognostic evaluation in a larger population of head and neck squamous cell carcinomas.
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Chiodini F, Charpantier E, Muller D, Tassonyi E, Fuchs-Buder T, Bertrand D. Blockade and activation of the human neuronal nicotinic acetylcholine receptors by atracurium and laudanosine. Anesthesiology 2001; 94:643-51. [PMID: 11379686 DOI: 10.1097/00000542-200104000-00019] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Curaremimetic nondepolarizing muscle relaxants are widely used in clinical practice to prevent muscle contraction either during surgery or during intensive care. Although primarily acting at the neuromuscular junction, these compounds can cause adverse effects, including modification of cardiac rhythm, arterial blood pressure, and in the worst cases, triggering of seizures. In this study, we assessed the interaction of atracurium and its metabolite, laudanosine, with neuronal nicotinic receptors. METHODS The human neuronal nicotinic receptors alpha4beta2, alpha3beta4, alpha3alpha5beta4, and alpha7 are heterologously expressed in Xenopus laevis oocytes, and the effect of atracurium and its degradation product, laudanosine, were studied on these receptors. RESULTS Atracurium and laudanosine inhibited in the micromolar range the major brain alpha4beta2 receptor and the ganglionic alpha3beta4 or alpha3beta4alpha5 and the homomeric alpha7 receptors. For all four receptors, inhibition was rapid and readily reversible within less than 1 min. Atracurium blockade was competitive at alpha4beta2 and alpha7 receptors but displayed a noncompetitive blockade at the alpha3beta4 receptors. Inhibition at this receptor subtype was not modified by alpha5. Laudanosine was found to have a dual mode of action; first, it competes with acetylcholine and, second, it blocks the ionic pore by steric hindrance. At low concentrations, these two drugs are able to activate both the alpha4beta2 and the alpha3beta4 receptors. CONCLUSION Adverse effects observed during atracurium administration may be attributed, at least partly, to an interaction with neuronal nicotinic receptors.
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Vutskits L, Djebbara-Hannas Z, Zhang H, Paccaud JP, Durbec P, Rougon G, Muller D, Kiss JZ. PSA-NCAM modulates BDNF-dependent survival and differentiation of cortical neurons. Eur J Neurosci 2001; 13:1391-402. [PMID: 11298800 DOI: 10.1046/j.0953-816x.2001.01516.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We show that the loss or inactivation of the polysialic acid (PSA) tail of neural cell adhesion molecule (NCAM) on rat cortical neurons in culture leads to reduced differentiation and survival. The mechanism by which this negative effect is mediated appears to involve the neuronal response to brain-derived neurotrophic factor (BDNF): (i) in the absence of PSA or in the presence of excess free PSA added to the culture medium, BDNF-induced cell signalling is reduced; (ii) the addition of exogenous BDNF to the medium reverses the effect of PSA loss or inactivation. These data suggest that PSA-NCAM, previously shown to modulate cell migration and plasticity, is needed for an adequate sensitivity of neurons to BDNF.
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Abstract
High-frequency stimulation of excitatory synapses in many regions of the brain triggers a lasting increase in the efficacy of synaptic transmission referred to as long-term potentiation (LTP) and believed to contribute to learning and memory. One hypothesis proposed to account for the stability and properties of this functional plasticity is a structural remodeling of spine synapses. This possibility has recently received support from several studies. It has been found that spines are highly dynamic structures, that they can be formed very rapidly, and that synaptic activity and calcium modulate changes in spine shape and formation of new spines. Ultrastructural analyses bring additional support to these observations and suggest that LTP is associated with a remodeling of the postsynaptic density (PSD) and a process of spine duplication. This new information is reviewed and interpreted in light of other recent advances concerning the mechanisms of LTP and especially the role of postsynaptic glutamate receptor turnover in this form of plasticity. Taken together, a view is emerging that suggests that morphologic changes of spine synapses are associated with LTP and that they not only correlate with, but probably also contribute to the increase in synaptic transmission.
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148
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Hildeman D, Muller D. Immunopathologic weight loss in intracranial LCMV infection initiated by the anorexigenic effects of IL-1beta. Viral Immunol 2001; 13:273-85. [PMID: 11016593 DOI: 10.1089/08828240050144617] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Lymphocytic choriomeningitis virus (LCMV) infection of beta2-microglobulin-deficient (beta2m-/-) mice results in a substantial loss of body weight that is not mediated by the virus itself, but rather by CD4+ T cells responding to the viral infection. In this study, we further characterized LCMV-induced weight loss in immunocompetent and beta32m-/- mice. We show that intracranial (i.c.), but not intraperitoneal (i.p.) LCMV infection elicited significant weight loss and that weight loss was preceded by anorexia. Also, uninfected mice fed an equivalent amount as eaten by infected mice had similar weight loss compared to their infected counterparts. Interestingly, both weight loss and anorexia were greater in female than male beta2m-/- mice. LCMV-infected female beta2m-/- mice also had significantly more interleukin (IL)-betag in their cerebrospinal fluid (CSF) than did male beta2m-/- mice. Finally, intracerebroventricular (i.c.v.) administration of anti-IL-1beta antibody, but not control immunoglobulin G (IgG), attenuated the initial weight loss and increased food intake. Taken together, these results suggest that the majority of weight loss after intracranial LCMV infection is the result of anorexia and IL-1beta mediates initial anorexic weight loss.
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Abe K, Abe K, Abe T, Adam I, Akimoto H, Aston D, Baird KG, Baltay C, Band HR, Barklow TL, Bauer JM, Bellodi G, Berger R, Blaylock G, Bogart JR, Bower GR, Brau JE, Breidenbach M, Bugg WM, Burke D, Burnett TH, Burrows PN, Calcaterra A, Cassell R, Chou A, Cohn HO, Coller JA, Convery MR, Cook V, Cowan RF, Crawford G, Damerell CJ, Daoudi M, de Groot N, de Sangro R, Dong DN, Doser M, Dubois R, Erofeeva I, Eschenburg V, Etzion E, Fahey S, Falciai D, Fernandez JP, Flood K, Frey R, Hart EL, Hasuko K, Hertzbach SS, Huffer ME, Huynh X, Iwasaki M, Jackson DJ, Jacques P, Jaros JA, Jiang ZY, Johnson AS, Johnson JR, Kajikawa R, Kalelkar M, Kang HJ, Kofler RR, Kroeger RS, Langston M, Leith DW, Lia V, Lin C, Mancinelli G, Manly S, Mantovani G, Markiewicz TW, Maruyama T, McKemey AK, Messner R, Moffeit KC, Moore TB, Morii M, Muller D, Murzin V, Narita S, Nauenberg U, Neal H, Nesom G, Oishi N, Onoprienko D, Osborne LS, Panvini RS, Park CH, Peruzzi I, Piccolo M, Piemontese L, Plano RJ, Prepost R, Prescott CY, Ratcliff BN, Reidy J, Reinertsen PL, Rochester LS, Rowson PC, Russell JJ, Saxton OH, Schalk T, Schumm BA, Schwiening J, Serbo VV, Shapiro G, Sinev NB, Snyder JA, Staengle H, Stahl A, Stamer P, Steiner H, Su D, Suekane F, Sugiyama A, Suzuki S, Swartz M, Taylor FE, Thom J, Torrence E, Usher T, Va'vra J, Verdier R, Wagner DL, Waite AP, Walston S, Weidemann AW, Weiss ER, Whitaker JS, Williams SH, Willocq S, Wilson RJ, Wisniewski WJ, Wittlin JL, Woods M, Wright TR, Yamamoto RK, Yashima J, Yellin SJ, Young CC, Yuta H. Improved direct measurement of leptonic coupling asymmetries with polarized Z bosons. PHYSICAL REVIEW LETTERS 2001; 86:1162-1166. [PMID: 11178034 DOI: 10.1103/physrevlett.86.1162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2000] [Indexed: 05/23/2023]
Abstract
We present final measurements of the Z boson-lepton coupling asymmetry parameters A(e), A(mu), and A(tau) with the complete sample of polarized Z bosons collected by the SLD detector at the SLAC Linear Collider. From the left-right production and decay polar angle asymmetries in leptonic Z decays we measure A(e) = 0.1544+/-0.0060, A(mu) = 0.142+/-0.015, and A(tau) = 0.136+/-0.015. Combined with our left-right asymmetry measured from hadronic decays, we find A(e) = 0.1516+/-0.0021. Assuming lepton universality, we obtain a combined effective weak mixing angle of sin (2)theta(eff)(W) = 0.230 98+/-0.000 26.
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Abe K, Abe K, Abe T, Adam I, Akimoto H, Aston D, Baird KG, Baltay C, Band HR, Barklow TL, Bauer JM, Bellodi G, Berger R, Blaylock G, Bogart JR, Bower GR, Brau JE, Breidenbach M, Bugg WM, Burke D, Burnett TH, Burrows PN, Calcaterra A, Cassell R, Chou A, Cohn HO, Coller JA, Convery MR, Cook V, Cowan RF, Crawford G, Damerell CJ, Daoudi M, de Groot N, de Sangro R, Dong DN, Doser M, Dubois R, Erofeeva I, Eschenburg V, Etzion E, Fahey S, Falciai D, Fernandez JP, Flood K, Frey R, Hart EL, Hasuko K, Hertzbach SS, Huffer ME, Huynh X, Iwasaki M, Jackson DJ, Jacques P, Jaros JA, Jiang ZY, Johnson AS, Johnson JR, Kajikawa R, Kalelkar M, Kang HJ, Kofler RR, Kroeger RS, Langston M, Leith DW, Lia V, Lin C, Mancinelli G, Manly S, Mantovani G, Markiewicz TW, Maruyama T, McKemey AK, Messner R, Moffeit KC, Moore TB, Morii M, Muller D, Murzin V, Narita S, Nauenberg U, Neal H, Nesom G, Oishi N, Onoprienko D, Osborne LS, Panvini RS, Park CH, Peruzzi I, Piccolo M, Piemontese L, Plano RJ, Prepost R, Prescott CY, Ratcliff BN, Reidy J, Reinertsen PL, Rochester LS, Rowson PC, Russell JJ, Saxton OH, Schalk T, Schumm BA, Schwiening J, Serbo VV, Shapiro G, Sinev NB, Snyder JA, Staengle H, Stahl A, Stamer P, Steiner H, Su D, Suekane F, Sugiyama A, Suzuki A, Swartz M, Taylor FE, Thom J, Torrence E, Usher T, Va'vra J, Verdier R, Wagner DL, Waite AP, Walston S, Weidemann AW, Weiss ER, Whitaker JS, Williams SH, Willocq S, Wilson RJ, Wisniewski WJ, Wittlin JL, Woods M, Wright TR, Yamamoto RK, Yashima J, Yellin SJ, Young CC, Yuta H. First symmetry tests in polarized Z0 decays to bbg. PHYSICAL REVIEW LETTERS 2001; 86:962-966. [PMID: 11177985 DOI: 10.1103/physrevlett.86.962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2000] [Indexed: 05/23/2023]
Abstract
We have made the first direct symmetry tests in the decays of polarized Z0 bosons into fully identified bbg states, collected in the SLD experiment at SLAC. We searched for evidence of parity violation at the bbg vertex by studying the asymmetries in the b-quark polar- and azimuthal-angle distributions, and for evidence of T-odd, CP-even or CP-odd, final-state interactions by measuring angular correlations between the three-jet plane and the Z0 polarization. We found results consistent with standard model expectations and set 95% C. limits on anomalous contributions.
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