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Izzet G, Zeng X, Over D, Douziech B, Zeitouny J, Giorgi M, Jabin I, Mest YL, Reinaud O. First Insights into the Electronic Properties of a Cu(II) Center Embedded in the PN3 Cap of a Calix[6]arene-Based Ligand. Inorg Chem 2006; 46:375-7. [PMID: 17279813 DOI: 10.1021/ic0620384] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first metal complex based on the calix[6]PN3 cryptand is described. The solid-state and solution studies show a 5-coordinate Cu(II) center due to its coordination to the PN3 cap and to an exchangeable guest molecule. Spectroscopic and electrochemical studies evidence surprising properties of the metal ion, which are tentatively assigned to the unusual P-Cu(II) bond enforced by the cryptand.
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202
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Kaizer J, Goger S, Speier G, Reglier M, Giorgi M. Crystal structure of μ-dichlorobis(N-benzyl-bis(2-pyridylmethyl) amino)dicopper(II) diperchlorate ethanol solvate (1:⅔), [CU2C12{N(C6H6N)2(C7H7)}2][CIO4]2 · ⅔ C2H5OH. Z KRIST-NEW CRYST ST 2006. [DOI: 10.1524/ncrs.2006.221.14.75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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203
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Kaizer J, Góger S, Speier G, Réglier M, Giorgi M. Crystal structure of μ-dichlorobis(N-benzyl-bis(2-pyridylmethyl) amino)dicopper(II) diperchlorate ethanol solvate (1:⅔), [Cu2Cl2{N(C6H6N)2(C7H7)}2][ClO4]2 · ⅔ C2H5OH. Z KRIST-NEW CRYST ST 2006. [DOI: 10.1524/ncrs.2006.221.1.75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract C39.33H42Cl4Cu2N6O8.67, trigonal, R3̅ (no. 148), a = 27.819(4) Å, c = 14.447(6) Å, V = 9682.8 Å3, Z = 9, Rgt(F) = 0.040, wRref(F2) = 0.109, T = 293 K.
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204
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Renaudeau D, Giorgi M, Silou F, Weisbecker JL. Effect of Breed (Lean or Fat Pigs) and Sex on Performance and Feeding Behaviour of Group Housed Growing Pigs in a Tropical Climate. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2006. [DOI: 10.5713/ajas.2006.593] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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205
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Ourhriss N, Giorgi M, Mazoir N, Benharref A. Absolute configuration and conformational disorder of a tricyclic thiosemicarbazone derivative. Acta Crystallogr C 2005; 61:o699-701. [PMID: 16330851 DOI: 10.1107/s0108270105033470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2005] [Accepted: 10/17/2005] [Indexed: 11/10/2022] Open
Abstract
The title compound, (1S,3R,8R)-2,2-dichloro-3,7,7,10-tetramethyltricyclo[6.4.0.0(1,3)]dodecan-11-one thiosemicarbazone, C17H25Cl2N3S, has two disordered conformations of the cycloheptane moiety and a screw-boat conformation for the cyclohexene ring. The absolute configuration was established.
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206
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Croix C, Balland-Longeau A, Allouchi H, Giorgi M, Duchêne A, Thibonnet J. Organogold(I) complexes: Synthesis, X-ray crystal structures and aurophilicity. J Organomet Chem 2005. [DOI: 10.1016/j.jorganchem.2005.07.080] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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207
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Alexakhin VY, Alexandrov Y, Alexeev GD, Amoroso A, Badełek B, Balestra F, Ball J, Baum G, Bedfer Y, Berglund P, Bernet C, Bertini R, Birsa R, Bisplinghoff J, Bradamante F, Bravar A, Bressan A, Burtin E, Bussa MP, Cerini L, Chapiro A, Cicuttin A, Colantoni M, Colavita AA, Costa S, Crespo ML, d'Hose N, Dalla Torre S, Dasgupta SS, De Masi R, Dedek N, Denisov OY, Dhara L, Diaz Kavka V, Dolgopolov AV, Donskov SV, Dorofeev VA, Doshita N, Duic V, Dünnweber W, Efremov A, Ehlers J, Eversheim PD, Eyrich W, Fabro M, Faessler M, Fauland P, Ferrero A, Ferrero L, Finger M, Finger M, Fischer H, Franz J, Friedrich JM, Frolov V, Fuchs U, Garfagnini R, Gautheron F, Gavrichtchouk OP, Gerassimov S, Geyer R, Giorgi M, Gobbo B, Goertz S, Grajek OA, Grasso A, Grube B, Grünemaier A, Gustafsson K, Hannappel J, von Harrach D, Hasegawa T, Hedicke S, Heinsius FH, Hinterberger F, von Hodenberg M, Horikawa N, Horikawa S, Ijaduola RB, Ilgner C, Ishimoto S, Iwata T, Jahn R, Janata A, Joosten R, Jouravlev NI, Kabuss E, Kalinnikov V, Kang D, Karstens F, Kastaun W, Ketzer B, Khaustov GV, Khokhlov YA, Kisselev Y, Klein F, Koivuniemi JH, Kolosov VN, Komissarov EV, Kondo K, Königsmann K, Konoplyannikov AK, Konorov I, Konstantinov VF, Korentchenko AS, Korzenev A, Kotzinian AM, Koutchinski NA, Kowalik K, Kravchuk NP, Krivokhizhin GV, Kroumchtein ZV, Kuhn R, Kunne F, Kurek K, Lamanna M, Le Goff JM, Leberig M, Lichtenstadt J, Maggiora A, Maggiora M, Magnon A, Mallot GK, Manuilov IV, Marchand C, Marroncle J, Martin A, Marzec J, Matsuda T, Maximov AN, Medved KS, Meyer W, Mielech A, Mikhailov YV, Moinester MA, Nähle O, Nassalski J, Neyret DP, Nikolaenko VI, Nozdrin AA, Obraztsov VF, Olshevsky AG, Ostrick M, Padee A, Pagano P, Panebianco S, Panzieri D, Paul S, Pereira HD, Peshekhonov DV, Peshekhonov VD, Piragino G, Platchkov S, Platzer K, Pochodzalla J, Polyakov VA, Popov AA, Pretz J, Rebourgeard PC, Reicherz G, Reymann J, Rozhdestvensky AM, Rondio E, Sadovski AB, Saller E, Samoylenko VD, Sandacz A, Sans M, Sapozhnikov MG, Savin IA, Schiavon P, Schmidt T, Schmitt H, Schmitt L, Shishkin AA, Siebert H, Sinha L, Sissakian AN, Skachkova A, Slunecka M, Smirnov GI, Sugonyaev VP, Stinzing F, Sulej R, Takabayashi N, Tchalishev VV, Tessarotto F, Teufel A, Thers D, Tkatchev LG, Toeda T, Tretyak VI, Trousov S, Vlassov NV, Webb R, Weise E, Wiesmann M, Windmolders R, Wirth S, Wiślicki W, Zanetti AM, Zaremba K, Zhao J, Ziegler R, Zvyagin A. First measurement of the transverse spin asymmetries of the deuteron in semi-inclusive deep inelastic scattering. PHYSICAL REVIEW LETTERS 2005; 94:202002. [PMID: 16090237 DOI: 10.1103/physrevlett.94.202002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Indexed: 05/03/2023]
Abstract
First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors.
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208
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Crozet MD, Giorgi M, Terme T, Vanelle P. Crystal structure of diethyl 2-( 1-methyl-5-nitro- 1H-imidazol- 4-ylmethylene)malonate, C12H15N3O6. Z KRIST-NEW CRYST ST 2005. [DOI: 10.1524/ncrs.2005.220.14.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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209
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Crozet MD, Giorgi M, Terme T, Vanelle P. Crystal structure of diethyl 2-(2-methyl-5-nitrothiazol- 4-ylmethylene)malonate, C12H14N2O6S. ACTA ACUST UNITED AC 2005. [DOI: 10.1524/ncrs.2005.220.14.229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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210
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211
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Selmeczi K, Speier G, Réglier M, Giorgi M. Crystal structure of [N,N-bis(2-[2-pyridyl]ethyl)-2-(2-aminoethoxy)ethanol]- copper(II) bis(trifluoromethanesulfonate), (CuC18H25N3O2)(F3CSO3)2. Z KRIST-NEW CRYST ST 2004. [DOI: 10.1524/ncrs.2004.219.14.153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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212
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Amatori FM, Meucci V, Giusiani M, Soldani G, Corazza M, Giorgi M. Effect of grapefruit juice on the pharmacokinetics of cyclosporine in dogs. Vet Rec 2004; 154:180-1. [PMID: 14979675 DOI: 10.1136/vr.154.6.180] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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213
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Meucci V, Gasperini A, Soldani G, Guidi G, Giorgi M. A New HPLC Method to Determine Glomerular Filtration Rate and Effective Renal Plasma Flow in Conscious Dogs by Single Intravenous Administration of Iohexol and p-Aminohippuric Acid. J Chromatogr Sci 2004; 42:107-11. [PMID: 15023265 DOI: 10.1093/chromsci/42.2.107] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A high-performance liquid chromatography method to determine iohexol (IOX) and p-aminohippuric acid (PAH) in the plasma of dogs is evaluated according to recovery, reproducibility, and linearity utilizing a gradient pump. The mobile phase consists of 50mM sodium dihydrogen phosphate with 0.5mM tetrabutylammonium chloride, the pH is adjusted to 4.1, methanol is added to the final ratio of 90:10 (v/v), the flow rate is set at 1 mL/min, and separation is achieved with an ODS2 Luna column. The UV detector is set at 254 nm. IOX and PAH are used for evaluation of the effective renal plasma flow (ERPF) and glomerular filtration rate (GFR). The present method tested in three dogs demonstrates the accuracy in the evaluation of ERPF and GFR. Because of its precision and simplicity and low cost, it can be considered a good tool for ERPF and GFR in small animal practice.
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214
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Rossi P, Giorgi M, Minutella L, Muccini E, Pacchini P, Virgili N. 1201 Relationships between anemia and polichemotherapy in cancer patients. EJC Suppl 2003. [DOI: 10.1016/s1359-6349(03)91227-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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215
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Vaccaro E, Giorgi M, Longo V, Mengozzi G, Gervasi PG. Inhibition of cytochrome p450 enzymes by enrofloxacin in the sea bass (Dicentrarchus labrax). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2003; 62:27-33. [PMID: 12413791 DOI: 10.1016/s0166-445x(02)00064-4] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Currently, there are no reports on the effects of enrofloxacin (EF), a fluoroquinolone antibiotic, on the cytochrome p450 enzymes in fish, although its use as antimicrobial agent in aquaculture has been put forward. Therefore, the in vivo and in vitro effects of EF on hepatic p450 enzymes of sea bass, a widespread food-producing fish, have been evaluated. Sea bass pretreated with a single dose of EF (3 mg/kg i.p.) or with three daily doses of EF (1 mg/kg i.p.) markedly depressed the microsomal N-demethylation of aminopyrine, erythromycin, the O-deethylation of 7-ethoxycoumarin, ethoxyresorufin and the 6beta-testosterone hydroxylase. In vitro experiments showed that EF at 10 microM inhibited the above-mentioned activities and, in particular, the erythromycin N-demethylase (ERND) and 6beta-testosterone-hydroxylase, likely dependant on a p450 3A isoform. When the nature of ERND inhibition by EF was specifically studied with sea bass liver microsomes, it was found that EF is a potent mechanism-based inhibitor, with K(i) of 3.7 microM and a K(inact) of 0.045 min(-1). An immunoblot analysis with anti p450 3A27 of trout showed that the p450 3A isoform, constitutively expressed in sea bass, is particularly susceptible to inactivation by EF. In vitro experiments with sea bass microsomes have also demonstrated that EF is oxidative deethylated by the p450 system to ciprofloxacin (CF) and that this compound maintains the ability to inactivate the p450 enzymes. The mechanism by which EF or CF inactivate the p450 enzymes has not been studied but an attack of p450 on the cyclopropan ring, present, both in EF and CF structure, with the formation of electrophilic intermediates (i.e. radicals) has been postulated. In conclusion, the EF seems to be a powerful inhibitor of p450s in the sea bass. Therefore, the clinical use of this antibiotic in aquaculture has to be considered with caution.
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216
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Giorgi M, Meucci V, Vaccaro E, Mengozzi G, Giusiani M, Soldani G. Effects of liquid and freeze-dried grapefruit juice on the pharmacokinetics of praziquantel and its metabolite 4′-hydroxy praziquantel in beagle dogs. Pharmacol Res 2003; 47:87-92. [PMID: 12526866 DOI: 10.1016/s1043-6618(02)00251-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Grapefruit juice changes the pharmacokinetic parameters of a variety of drugs metabolized primarily by cytochrome P450 3A. In a three-phase crossover study, six male beagle dogs were administered 100 ml of water (control), 100 ml of commercial liquid grapefruit juice, or 10 g of freeze-dried grapefruit juice (equivalent to 100 ml of liquid grapefruit juice) with 100 ml of water, followed after 2 h by single oral dose of praziquantel (30 mg kg(-1)). After treatment, the dogs were sampled at different times. Determination of praziquantel and its metabolite 4'-hydroxy praziquantel (identified by GC/MS) was performed by HPLC. Liquid and freeze-dried grapefruit juice preadministration increased the C(max) of praziquantel about three-fold and the AUC 2.5- and 2.3-fold, respectively. The T(max) (0.75 h) was unaffected by liquid or freeze-dried grapefruit juice, while T(1/2) was 2.3- and 1.7-fold higher compared with controls. The amount of 4'-hydroxy praziquantel was also affected by both liquid and freeze-dried grapefruit juice administration: the AUC and C(max) increased four- and three-fold, respectively and the T(max) was significantly enhanced. These findings demonstrate that both freeze-dried grapefruit juice and commercial liquid grapefruit juice significantly increase plasma concentrations and T(1/2) of praziquantel in dogs.
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217
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Dionisio D, Vivarelli A, Zazzi M, Esperti F, Fabbri C, Giorgi M, Menichini B. Long-term CD4+ T-cell response in HIV-1-infected patients continuing combination antiretroviral therapy despite high-level viremia and drug resistance. Eur J Clin Microbiol Infect Dis 2003; 22:69-71. [PMID: 12582750 DOI: 10.1007/s10096-002-0845-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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218
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Mengozzi G, Intorre L, Bertini S, Giorgi M, Secchiari PL, Soldani G. A comparative kinetic study of thiamphenicol in pre-ruminant lambs and calves. Res Vet Sci 2002; 73:291-5. [PMID: 12443688 DOI: 10.1016/s0034-5288(02)00110-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Eight healthy Holstein-Friesian calves and 8 Massese lambs of either sex (10-15-days old) were used to evaluate the pharmacokinetics of thiamphenicol after intravenous (i.v.) and oral (p.o.) administration (30 mg/kg). Plasma concentrations of thiamphenicol were determined by high-performance liquid chromatography on blood samples collected over 24h following treatment. Pharmacokinetic variables of the drug were calculated for both species and after both administration routes. After intravenous administration of thiamphenicol, a rapid distribution phase was followed by a slower elimination phase and, when thiamphenicol was administered p.o., the bioavailability was about 60% in both species. The higher volume of distribution and the longer biological elimination half-lives in pre-ruminant compared with adult animals indicate that thiamphenicol distributes widely into the extravascular compartment of pre-ruminants. Interspecies differences were observed in the kinetic behaviour of thiamphenicol with respect to peak plasma concentration (C(max)), time of peak plasma concentration (T(max)), elimination half-life (T(1/2)) and total clearance (Cl(B)). In conclusion intravenous or oral administration of 30 mg/kg of thiamphenicol provides plasma concentrations higher than minimum effective concentrations inhibiting bacterial growth (MICs) against most pathogens in pre-ruminant lambs and calves.
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219
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Balogh-Hergovich É, Speier G, Réglier M, Giorgi M. Crystal structure of 1,4-di-(2’-pyridyl)aminophthalazine, C18H14N6. Z KRIST-NEW CRYST ST 2002. [DOI: 10.1524/ncrs.2002.217.1.61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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220
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Bibila Mayaya Bisseyou Y, Kakou-Yao R, Uncuta C, Ebby N, Aycard JP, Giorgi M. Crystal structure of l-isopropyl-2,3,4,6-tetramethylpyridinium Perchlorate, C12H20ClNO4. Z KRIST-NEW CRYST ST 2002. [DOI: 10.1524/ncrs.2002.217.jg.289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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221
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Balogh-Hergovich É, Speier G, Réglier M, Giorgi M. Crystal structure of 1,4-di-(2’-pyridyl)aminophthalazine, C18H14N6. Z KRIST-NEW CRYST ST 2002. [DOI: 10.1524/ncrs.2002.217.jg.61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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222
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Bibila Mayaya Bisseyou Y, Kakou-Yao R, Uncuta C, Ebby N, Aycard JP, Giorgi M. Crystal structure of l-isopropyl-2,3,4,6-tetramethylpyridinium Perchlorate, C12H20ClNO4. Z KRIST-NEW CRYST ST 2002. [DOI: 10.1524/ncrs.2002.217.1.289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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223
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Crozet MD, Vanelle P, Giorgi M, Gellis A. 2-[2-Methyl-5-nitro-4-(phenylsulfonylmethyl)imidazol-1-yl]ethanol and 2-methyl-5-nitro-4-phenylsulfonylmethyl-1,3-thiazole. Acta Crystallogr C 2002; 58:o496-8. [PMID: 12154310 DOI: 10.1107/s0108270102011964] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2002] [Accepted: 07/05/2002] [Indexed: 11/11/2022] Open
Abstract
The title compounds, C(13)H(15)N(3)O(5)S and C(11)H(10)N(2)O(4)S(2), respectively, both contain a phenylsulfonyl group connected, through a methylene bridge, to either a substituted nitroimidazole or nitro-1,3-thiazole ring. In the imidazole-containing molecule, the nitro and sulfonyl groups are trans relative to the sulfonyl-methyl bond, while in the thiazole-containing molecule, these substituents are cis. The stabilizing interactions within the crystals are also different between the two compounds.
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224
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Bisseyou YBM, Kakou-Yao R, Uncuta C, Ebby N, Aycard JP, Giorgi M. Crystal structure of 1-isopropyl-2,3,4,6-tetramethylpyridinium perchlorate, C12H20ClNO4. Z KRIST-NEW CRYST ST 2002. [DOI: 10.1524/ncrs.2002.217.2.289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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225
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Giorgi M, Leonetti C, Citro G, Augusti-Tocco G. In vitro and in vivo inhibition of SK-N-MC neuroblastoma growth using cyclic nucleotide phosphodiesterase inhibitors. J Neurooncol 2001; 51:25-31. [PMID: 11349877 DOI: 10.1023/a:1006489020190] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The effect of cyclic nucleotide phosphodiesterase (PDE) inhibitors Zaprinast and DC-TA-46 has been tested on SK-N-MC neuroblastoma growth. Antiproliferative activity of the tested drugs was assayed both in vitro and in the xenograft model of nude mice. In clonal density experiments, the IC50 value was 3.3 microM for Zaprinast and 1.9 microM for DC-TA-46, while 7.5 microM BCNU alkylating agent was required to obtain the same effect. SK-N-MC cells xenografted in the nude mouse showed that the administration of Zaprinast and DC-TA-46 caused a significant 50% decrease of the tumour weight. These data demonstrate that PDE inhibitors may be useful for at least reducing tumour growth; they may be of interest for further evaluation as alternative molecules in the design of multiple agent protocols for neuroblastoma treatment.
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226
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Pretti C, Salvetti A, Longo V, Giorgi M, Gervasi PG. Effects of beta-naphthoflavone on the cytochrome P450 system, and phase II enzymes in gilthead seabream (Sparus aurata). Comp Biochem Physiol C Toxicol Pharmacol 2001; 130:133-44. [PMID: 11544149 DOI: 10.1016/s1532-0456(01)00231-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The effect of beta-naphthoflavone (beta-NF) on several catalytic activities of cytochrome P450 (CYP) and phase II enzymes putatively controlled by [Ah]-receptor activation in the liver, heart and kidney of gilthead seabream, was investigated. In the liver, beta-NF treatment [intraperitoneal injection (i.p.) 50 mg/kg] resulted in an increase of CYP content, immunoreactive CYP 1A and methoxyresorufin-O-demethylase (MEROD), pentoxyresorufin O-depentylase (PROD) and ethoxyresorufin-O-deethylase (EROD) activities. However, beta-NF had no effect on any of the hepatic phase II enzymes examined (benzaldehyde dehydrogenase, propionaldehyde dehydrogenase, glutathione S-transferase, UDP-glucuronyl-transferase, DT-diaphorase). Single i.p. injection of 10 mg/kg beta-NF showed a maximal induction of CYP 1A-like protein and EROD activity after 3-7 days. CYP 1A and EROD returned to control levels 18-days post-treatment. beta-NF injection also caused a rapid increase of a single band size of mRNA recognized by a CYP 1A1 cDNA fragment from sea bass (Dicentrarchus labrax). Expression of mRNA preceded the increase of EROD activity and declined rapidly by 96 h. Dose-response experiments demonstrated that EROD was significantly enhanced in liver by a single injection of 0.3 mg/kg beta-NF and was the most sensitive measurement for CYP 1A-like induction. beta-NF treatments also increased the expression of CYP 1A-like protein, mRNA and EROD, but not MEROD and PROD activities in heart and kidney.
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227
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Sénèque O, Rager MN, Giorgi M, Reinaud O. Supramolecular stabilization of a tris(imidazolyl) Zn-aqua complex evidenced by X-ray analysis: a structural model for mono-zinc active sites of enzymes. J Am Chem Soc 2001; 123:8442-3. [PMID: 11516312 DOI: 10.1021/ja016345e] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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228
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Giorgi M, Salvatori AP, Soldani G, Giusiani M, Longo V, Gervasi PG, Mengozzi G. Pharmacokinetics and microsomal oxidation of praziquantel and its effects on the P450 system in three-month-old lambs infested by Fasciola hepatica. J Vet Pharmacol Ther 2001; 24:251-9. [PMID: 11555180 DOI: 10.1046/j.1365-2885.2001.00341.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Praziquantel (PZQ) is a broadly effective trematocide and cestocide, widely employed in veterinary and human medicine. In view of several differences in both its pharmacokinetic profile in different animal species and in the cytochrome P450-dependent system between ruminant and nonruminant species, the present study was undertaken to determine the pharmacokinetics of this drug, its effects on the P450 system and the involvement of cytochrome P450 in its metabolism in 3-month-old lambs infested by Fasciola hepatica. Following both oral and i.m. administration, PZQ disposition was best described by a linear one-compartment open model with a rapid absorption and elimination. Although the PZQ dose used by the i.m. route was only half of that used by the oral route, the mean PZQ plasma concentration was higher after i.m. than after oral treatment. Oral treatment with 30 mg/kg/day of PZQ did not modify the mono-oxygenase activities tested, whilst the administration of PZQ at a dose of 60 mg/kg/day for 2 days caused a significant decrease in the P450 3A-dependent erythromycin N-demethylase and 6beta testosterone hydroxylase activities. From the incubation of microsomes from lambs not treated with PZQ, a single metabolite (PZQ 11b-OH or PZQ 1-OH) was identified by GC/MS analysis. By selective inhibition of the 3A subfamily performed with triacetyloleandromycin, the production of this metabolite declined by about 90% suggesting a prominent role of P450 3A isoforms in this oxidation. These features indicate that agents or drugs which are able to modulate P450 3A-dependent catalysis may interfere with the metabolism, bioavailability and therapeutic effects of PZQ.
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229
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Giorgi M, Bertini S, Soldani G, Giusiani M. Comparison of HPLC and GC-MS methods for determination of embutramide (a component of Tanax or T-61) in biological specimens. J Anal Toxicol 2001; 25:323-7. [PMID: 11499885 DOI: 10.1093/jat/25.5.323] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Tanax or T-61, a euthanasia solution commonly used in veterinary medicine, has been often involved in suicide attempts (humans) and malicious intoxications (animals). For forensic reasons, the identification of one or more of the three components (embutramide, mebenzonium iodide, and tetracaine hydrochloride) of Tanax is needed to confirm the hypothesis of intoxication. This study was performed with new high-performance liquid chromatographic and gas chromatographic-mass spectrometric methods to identify embutramide in biological matrices (blood, liver, kidney) from different animal species. The good sensitivity and specificity of both methods recommend their use in toxicological analysis in both human and veterinary medicine.
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230
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Giorgi M, Cianci CD, Gallagher PG, Morrow JS. Spectrin oligomerization is cooperatively coupled to membrane assembly: a linkage targeted by many hereditary hemolytic anemias? Exp Mol Pathol 2001; 70:215-30. [PMID: 11418000 DOI: 10.1006/exmp.2001.2377] [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: 11/22/2022]
Abstract
In the erythrocyte, ankyrin is the major adapter protein linking tetramers of band 3 to the spectrin-actin cytoskeleton. This linkage involves a direct interaction between ankyrin and the 14th-15th repeat unit of beta-spectrin. The spectrin cytoskeleton itself is stabilized by the self-association of spectrin heterodimers into tetramers and larger oligomers, a process mediated by the 17th repeat unit of beta-spectrin and a short NH(2) -terminal sequence in alpha-spectrin. The self-association of spectrin and its ankyrin-mediated membrane binding have generally been considered independent events. We now demonstrate that spectrin self-association, the binding of spectrin to ankyrin, and the binding of ankyrin to the 43-kDa cytoplasmic domain of band 3 (cdb3) are coupled in a positively cooperative way. In solution, [(125)I]-labeled ankyrin was found by ND-PAGE3 to enhance the affinity of spectrin self-association by 10-fold. The reciprocal process was also true, in that spectrin tetramers and oligomers bound ankyrin with enhanced affinity relative to dimer spectrin. Saturation of the beta-spectrin self-association site by an NH(2) -terminal 80-kDa alpha-spectrin peptide enhanced the affinity of spectrin dimer for ankyrin, indicating a direct relationship between ankyrin binding and the occupancy of the beta-spectrin self-association site. cdb3 accentuated these cooperative interactions. Several inherited spectrin mutations that cause hemolytic disease but that do not directly destabilize the self-association or ankyrin-binding sites can be explained by these results. Three classes of mutations appear to disrupt cooperative coupling between self-association and ankyrin binding: (i) mutation of the linker sequences that join helices C and A in repeat units that intervene between the two functional sites, mutations that presumably block repeat-to-repeat transfer of conformational information; (ii) mutations in alpha-spectrin repeats 4 to 6 that disrupt the ability of this region to trans-regulate ankyrin binding by the adjacent beta-spectrin repeats 14-15; and (iii) exon-skipping mutations that shorten alpha-spectrin and force repeats 4 to 6 to fall out-of-register with the ankyrin-binding motif in beta-spectrin. Collectively, these results demonstrate a molecular mechanism whereby a membrane receptor can directly promote cytoskeletal assembly.
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231
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Giordano D, De Stefano ME, Citro G, Modica A, Giorgi M. Expression of cGMP-binding cGMP-specific phosphodiesterase (PDE5) in mouse tissues and cell lines using an antibody against the enzyme amino-terminal domain. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1539:16-27. [PMID: 11389965 DOI: 10.1016/s0167-4889(01)00086-6] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We have produced a polyclonal antibody that specifically recognizes cGMP-binding cGMP-specific phosphodiesterase (PDE5). The antibody was raised in rabbit using as immunogen a fusion protein, in which glutathione S-transferase was coupled to a 171 amino acid polypeptide of the N-terminal region of bovine PDE5. The antibody is able to immunoprecipitate PDE5 activity from mouse tissues and neuroblastoma extracts while it has no effect on all other PDE isoforms present in the extracts. PDE5 activity recovered in the immunoprecipitates retains its sensitivity to specific inhibitors such as zaprinast (IC(50)=0.6 microM) and sildenafil (IC(50)=3.5 nM). Bands of the expected molecular mass were revealed when solubilized immunoprecipitates were analysed in Western blots. The antibody selectively stained cerebellar Purkinje neurones, which are known to express high levels of PDE5 mRNA. Western blot analysis of mouse tissues revealed the highest expression signal in mouse lung, followed by heart and cerebellum, while a lower signal was evident in brain, kidney and a very low signal was present in the liver. In the hybrid neuroblastoma-glioma NG108-15 cells the antibody revealed a high PDE5 induction after dibutyryl-cAMP treatment.
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232
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Kaizer J, Pap J, Speier G, Reglier M, Giorgi M. Crystal structure of {(µ-carbonato)bis[3,3 iminobis(N,N-dimethylpropyl-amine)]copper(II)}diperchloratehydrate,[(Cu(idpa))2(CO3)](ClO4)2·H2O. Z KRIST-NEW CRYST ST 2001. [DOI: 10.1524/ncrs.2001.216.14.553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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233
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Giorgi M, Romani M, Bagliacca M, Mengozzi G. Determination of thiamphenicol residues in albumin and yolk of hen eggs. J Vet Pharmacol Ther 2000; 23:397-9. [PMID: 11168918 DOI: 10.1046/j.1365-2885.2000.00275.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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234
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Gueddi A, Mernari B, Giorgi M, Pierrot M. Two 2,5-bis(2-pyridinyl)-1,3,4-oxadiazole–metal complexes (M= Cu and Ni). Acta Crystallogr C 2000. [DOI: 10.1107/s0108270100011707] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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235
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Giorgi M, Marini S, Longo V, Mazzaccaro A, Amato G, Gervasi PG. Cytochrome P450-dependent monooxygenase activities and their inducibility by classic P450 inducers in the liver, kidney, and nasal mucosa of male adult ring-necked pheasants. Toxicol Appl Pharmacol 2000; 167:237-45. [PMID: 10986015 DOI: 10.1006/taap.2000.8994] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study, several P450-dependent monoxygenase activities in the liver, kidney, and nasal mucosa of ring-necked pheasants were examined. In addition, the presence and inducibility of P450 isoenzymes in the hepatic and renal tissues of pheasants were examined by using typical substrates and inducers of P450s along with polyclonal antibodies raised against mammalian isoforms. Anti-rat P450 1A1 recognized in microsomes of both pheasant liver and kidney a protein that was markedly induced by beta-naphthoflavone and accompanied by an increase of various monooxygenases, in particular, methoxyresorufin-O-demethylase (MROD) activity. Anti-rat P450 2E1 revealed in microsomes of the pheasant liver but not in kidney an immunoreactive protein that was slightly induced by acetone but not accompanied by an increase of para-nitrophenol hydroxylase activity. On the other hand, acetone treatment caused an induction of other hepatic monoxygenases including MROD, erythromycin N-demethylase, and 6beta-testosterone hydroxylase. These two latter activities, known to be markers for 3A isoenzymes in rodents, were also enhanced in pheasant liver by phenobarbital but not by dexamethasone. The treatment with these two inducers also lacked to point out hepatic and renal proteins immunorelated to P450 3A or 2B subfamily, suggesting that these isoforms may be not expressed in pheasant. On the other hand, anti-rat P450 2C11 recognized two immunorelated proteins in the liver of both control and treated pheasants. The treatment with clofibrate, a mammalian inducer of 4A subfamily, induced both in liver and kidney of pheasant: i) a protein that cross-reacted with anti rat P450 4A1 and ii) the (omega) and (omega-1) lauric acid hydroxylase activities, known to be associated in mammals to this P450 subfamily. In the nasal mucosa of pheasant, a protein immunorelated to P450 2A and some monooxygenase activities (i.e., 7-ethoxycoumarin O-deethylase) linked, in mammals, to this isoform have been found; by contrast a protein immunoreactive with anti P450 2G1 was not found. In conclusion, the immunochemical properties and monooxygenase activities of constitutive and inducible P450s in pheasants were different not only from those of mammals but also from those of chickens. The findings of the present work also suggest that the P450 induction profiles might provide a potential biomarker of pheasant exposure to chemicals or environmental pollutants in the wild-field or in the stock-farm.
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Bertini S, Del Carratore R, Giorgi M, Bronzetti G, Della Croce C. Genotoxic and mono-oxygenase system effects of the fungicide maneb. Arch Toxicol 2000; 74:415-20. [PMID: 11043497 DOI: 10.1007/s002040000152] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The in vivo effects of a commercial preparation of maneb on mono-oxygenase activities of hepatic microsomes of basal and induced rats were examined. In vitro experiments with the D7 strain of yeast Saccharomyces cerevisiae were also performed. In both basal and induced rats maneb caused a decrease in cytochrome P-450 content and aniline hydroxylase. Immunoblotting analysis using anti-P-450 IIE1 antibodies confirmed the data obtained for aniline hydroxylase activity. Maneb was toxic in cells of S. cerevisiae. On the basis of in vivo and in vitro experiments it can be concluded that maneb possesses a toxic activity attributable to its main metabolite ethylene thiourea. Immunoblotting analysis indicates that maneb biotransformation influences the IIEI P-450 isoform.
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237
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Giorgi M, Seneque O, Rager MN, Reynaud O. Calix[6]Arenes: A Supramolecular Approach For The Modeling Of The Active Site Of Metalloenzymes. Acta Crystallogr A 2000. [DOI: 10.1107/s0108767300026830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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238
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Le Clainche L, Giorgi M, Reinaud O. Novel biomimetic calix[6]arene-based copper(II) complexes. Inorg Chem 2000; 39:3436-7. [PMID: 11196798 DOI: 10.1021/ic000072r] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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239
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Morrone A, Bardelli T, Donati MA, Giorgi M, Di Rocco M, Gatti R, Parini R, Ricci R, Taddeucci G, D'Azzo A, Zammarchi E. beta-galactosidase gene mutations affecting the lysosomal enzyme and the elastin-binding protein in GM1-gangliosidosis patients with cardiac involvement. Hum Mutat 2000; 15:354-66. [PMID: 10737981 DOI: 10.1002/(sici)1098-1004(200004)15:4<354::aid-humu8>3.0.co;2-l] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
GM1-gangliosidosis is a lysosomal storage disorder caused by deficiency of acid beta-galactosidase (GLB1). We report five new beta-galactosidase gene mutations in nine Italian patients and one fetus, segregating in seven unrelated families. Six of the eight patients with the infantile, severe form of the disease presented cardiac involvement, a feature rarely associated with GM1-gangliosidosis. Molecular analysis of the patients' RNA and DNA identified two new RNA splicing defects, three new and three previously described amino acid substitutions. Interestingly, all patients with cardiac involvement were homozygous for one of these mutations: R59H, Y591C, Y591N, or IVS14-2A>G. In contrast, all other patients were compound heterozygous for one of the following mutations: R201H, R482H, G579D, IVS8+2T>C. Although we could not directly correlate the presence of cardiac abnormalities with specific genetic lesions, the mutations identified in patients with cardiomyopathy fell in the GLB1 cDNA region common to the lysosomal enzyme and the Hbeta-Gal-related protein, also known as the elastin binding protein (EBP). Consequently, both molecules are affected by the mutations, and they may contribute differently to the occurrence of specific clinical manifestations.
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240
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Morrone A, Bardelli T, Donati M, Giorgi M, Di Rocco M, Gatti R, Parini R, Ricci R, Taddeucci G, D'Azzo A, Zammarchi E. β-galactosidase gene mutations affecting the lysosomal enzyme and the elastin-binding protein in GM1-gangliosidosis patients with cardiac involvement. Hum Mutat 2000. [DOI: 10.1002/(sici)1098-1004(200004)15:4<354::aid-humu8>3.3.co;2-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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241
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Abstract
In this overview the authors describe the use of Tanax (T-61) for euthanasia. Tanax is a solution with three components (embutramide, mebenzonium iodide and tetracaine hydrochloride) used for painless death in pets and laboratory animals. It is also used for malicious intoxication in animals and for suicide attempts in humans. After a description of the modality and outcome of intoxication, the authors report the secondary toxic effects evoked by N, N -dimethyl-formamide, the solvent employed to dissolve the three components of Tanax. Finally, the analytical methods used to identify Tanax components in biological fluids and tissues are described.
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Giorgi M, Morrone A, Donati MA, Ciani F, Bardelli T, Biasucci G, Zammarchi E. Lymphocyte mRNA analysis of the ornithine transcarbamylase gene in Italian OTCD male patients and manifesting carriers: identification of novel mutations. Hum Mutat 2000; 15:380-1. [PMID: 10737985 DOI: 10.1002/(sici)1098-1004(200004)15:4<380::aid-humu12>3.0.co;2-q] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A new simple, non-invasive method using ornithine transcarbamylase (OTC) mRNA isolated from peripheral blood (PBL) or lymphoblastoid cell lines has been performed. This approach based on reverse transcription and nested PCR to obtain a double strand PBL OTC cDNA allowed the identification of genetic lesions in five Italian families affected by OTC deficiency (OTCD). In the PBL OTC mRNA two new mutations, T262K and W265L, have been detected in three unrelated male OTCD patients with mild symptoms. One known mutation, T264A, has been identified in one manifesting carrier. The known mutation E310X, detected on genomic DNA of another manifesting carrier, failed to be detected in her PBL OTC mRNA because of the presence of a STOP codon. All mutations have been confirmed in the patients' and their relatives' genomic DNA. In three patients the mutations have also been confirmed in the mRNA isolated from frozen liver biopsy. The T262K amino acid substitution has been detected in a male's PBL OTC mRNA at homozygous state while a heterozygous pattern has been detected at the genomic DNA level, suggesting that the patient is a somatic mosaic for this mutation. Here we show that PBL OTC mRNA analysis is useful to detect genetic lesions in male and female OTCD patients.
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243
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Balogh-Hergovich E, Speier G, Tapodi B, Reglier M, Giorgi M. Crystal structure of 1,3-bis(2 -pyridylimino)isoindolinato- (dichloro)iron(III), Fe(C18H12N5)Cl2. Z KRIST-NEW CRYST ST 1999. [DOI: 10.1515/ncrs-1999-0489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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244
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Decréau R, Julliard M, Giorgi M. Bis(epi-globulyloxy)(phthalocyaninato)silicon, a new photosensitizer for the photodynamic therapy of cancer. Acta Crystallogr C 1999. [DOI: 10.1107/s0108270199008677] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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245
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Maggi F, Giorgi M, Fornai C, Morrica A, Vatteroni ML, Pistello M, Siciliano G, Nuccorini A, Bendinelli M. Detection and quasispecies analysis of hepatitis C virus in the cerebrospinal fluid of infected patients. J Neurovirol 1999; 5:319-23. [PMID: 10414523 DOI: 10.3109/13550289909015819] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Hepatitis C virus (HCV) is a leading cause of liver damage and has also been implicated in extrahepatic pathologies. We examined for HCV RNA paired CSF and plasma samples from 12 viremia positive patients using PCR. The CSF from 5/5 HIV-infected patients and 5/7 HIV-negative patients were HCV RNA positive. Branched DNA analysis showed that HCV loads in CSF were much lower than in plasma. Several HCV-positive CSF showed no evidence of blood contamination, impaired blood-brain barrier, or intrathecal IgG production. Comparison of HCV quasispecies in three sets of samples suggested that the virus in CSF was of plasma origin.
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246
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Benakli K, Crozet MP, Vanelle P, Giorgi M. ( E)-2-[2-(4-Chloromethylphenyl)vinyl]-1-methyl-5-nitro-1 H-imidazole. Acta Crystallogr C 1999. [DOI: 10.1107/s0108270199099424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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247
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Bonsi P, Augusti-Tocco G, Palmery M, Giorgi M. Aflatoxin B1 is an inhibitor of cyclic nucleotide phosphodiesterase activity. GENERAL PHARMACOLOGY 1999; 32:615-9. [PMID: 10382866 DOI: 10.1016/s0306-3623(98)00282-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Aflatoxin B1 (AFB1) action on cyclic nucleotide phosphodiesterase (PDE) activity has been tested on tissue extracts of various organs. In the presence of 100 microM AFB1 a significant inhibition of cAMP and cGMP hydrolytic activity is observed in all tested tissue extracts. However, cGMP hydrolytic activity appears more sensitive to AFB1 inhibition than cAMP hydrolytic activity and a considerably higher inhibition is observed in lung and spleen, than in liver, brain, kidney, and heart. When cGMP is used as substrate, the inhibitory response reaches 72% in lung and spleen extracts. We have also tested AFB1 effects on lung and liver PDE activity peaks separated by DEAE-cellulose chromatography. These data confirm the poor sensitivity to the toxin of all PDE activities present in liver, while the lung peak (where PDE V in present) shows a higher sensitivity to AFB1. In order to establish whether PDE V is in fact more sensitive to AFB1, we have used mouse neuroblastoma cells, in which cGMP hydrolytic activity has been shown to be due to PDE V only. In this case, the calculated IC50 is 24 microM and Dixon plot analysis shows a competitive inhibitory effect with a Ki of 16.7 microM. We have also used aflatoxin B2 and M2, and they proved to be much less effective than AFB1: AFB2 inhibits PDE V with an IC50 of 117 microM, while AFM2 does not show any effect. These results provide the first evidence of a competitive inhibition of AFB1 on an enzymatic activity and suggest that an alteration of cellular cyclic nucleotide levels may play a role in the mechanism of aflatoxin action.
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Calabresi P, Gubellini P, Centonze D, Sancesario G, Morello M, Giorgi M, Pisani A, Bernardi G. A critical role of the nitric oxide/cGMP pathway in corticostriatal long-term depression. J Neurosci 1999; 19:2489-99. [PMID: 10087063 PMCID: PMC6786075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
High-frequency stimulation (HFS) of corticostriatal glutamatergic fibers induces long-term depression (LTD) of excitatory synaptic potentials recorded from striatal spiny neurons. This form of LTD can be mimicked by zaprinast, a selective inhibitor of cGMP phosphodiesterases (PDEs). Biochemical analysis shows that most of the striatal cGMP PDE activity is calmodulin-dependent and inhibited by zaprinast. The zaprinast-induced LTD occludes further depression by tetanic stimulation and vice versa. Both forms of synaptic plasticity are blocked by intracellular 1H-[1,2,4]oxadiazolo[4, 3-a]quinoxalin-1-one (ODQ), a selective inhibitor of soluble guanylyl cyclase, indicating that an increased cGMP production in the spiny neuron is a key step. Accordingly, intracellular cGMP, activating protein kinase G (PKG), also induces LTD. Nitric oxide synthase (NOS) inhibitors N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME) and 7-nitroindazole monosodium salt (7-NINA) block LTD induced by either HFS or zaprinast, but not that induced by cGMP. LTD is also induced by the NO donors S-nitroso-N-acetylpenicillamine (SNAP) and hydroxylamine. SNAP-induced LTD occludes further depression by HFS or zaprinast, and it is blocked by intracellular ODQ but not by L-NAME. Intracellular application of PKG inhibitors blocks LTD induced by HFS, zaprinast, and SNAP. Electron microscopy immunocytochemistry shows the presence of NOS-positive terminals of striatal interneurons forming synaptic contacts with dendrites of spiny neurons. These findings represent the first demonstration that the NO/cGMP pathway exerts a feed-forward control on the corticostriatal synaptic plasticity.
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Maggi F, Fornai C, Morrica A, Vatteroni ML, Giorgi M, Marchi S, Ciccorossi P, Bendinelli M, Pistello M. Divergent evolution of hepatitis C virus in liver and peripheral blood mononuclear cells of infected patients. J Med Virol 1999. [PMID: 9890422 DOI: 10.1002/(sici)1096-9071(199901)57:1<57::aid-jmv8>3.0.co;2-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In infected individuals, hepatitis C virus (HCV) exists as a variably complex population of related genetic variants known as quasispecies. The quasispecies of HCV were studied previously in 10 chronically infected patients by single-strand conformation polymorphism analysis of a segment of the envelope gene E2/NS1 containing the hypervariable region 1 and it was found that certain variants (LC variants) were present both in the liver and in peripheral blood mononuclear cells (PBMC), others (L variants) were present in the liver but not in the PBMC, and still others (C variants) showed the opposite distribution. The sequence data obtained from nine such patients are reported, indicating that, within individual subjects, L and C variants are distinct phylogenetically. Results are described on the growth of HCV in stimulated healthy donor PBMC cultures supporting the concept that genetic divergence might stem, at least in part, from virus adaptation to growth in different cell types. This information may help to understand how HCV persists and produces disease in infected patients, especially with regard to extrahepatic pathology.
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Giordano D, Giorgi M, Sette C, Biagioni S, Augusti-Tocco G. cAMP-dependent induction of PDE5 expression in murine neuroblastoma cell differentiation. FEBS Lett 1999; 446:218-22. [PMID: 10100844 DOI: 10.1016/s0014-5793(99)00227-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The present study demonstrates, in both hybrid NG108-15 and mouse neuroblastoma N18TG2 cells, the presence and regulation of PDE5 mRNA during cell differentiation. PDE5 cDNA probes in Northern blot analysis recognize a approximately 9 kb transcript in bovine lung as well as in mouse neuroblastoma cells. Hybridization on total RNA extracted from dibutyryl-cAMP-treated NG108-15 cells shows a 5-fold increase of PDE5 9 kb mRNA: such an increase is not observed in N18TG2 although we observed a similar increase in the enzymatic activity of both cell lines. Our data demonstrate that PDE5 gene expression can be regulated by cAMP and suggest the existence of a complex regulatory system for PDE5 activity.
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