1
|
Nieuwjaer N, Beydoun A, Lecomte F, Manil B, Cappelluti F, Guidoni L, Scuderi D, Desfrançois C. IRMPD spectroscopy and quantum chemistry calculations on mono- and bi-metallic complexes of acetylacetonate ligands with aluminum, iron, and ruthenium ions. J Chem Phys 2020; 153:234303. [PMID: 33353333 DOI: 10.1063/5.0031653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Metal-ligand cluster ions are structurally characterized by means of gas-phase infrared multiple photon dissociation spectroscopy. The mass-selected complexes consist of one or two metal cations M3+ (M = Al, Fe, or Ru) and two to five anionic bidentate acetylacetonate ligands. Experimental IR spectra are compared with different density functional theory calculations, namely, PBE/TZVP, B3LYP/6-31G*, and M06/6-31+G**. Frequency analysis was also performed at different levels, namely, scaled static harmonic and unscaled static anharmonic, or with ab initio molecular dynamics simulations at the PBE/TZVP level. All methods lead to simulated spectra that fit rather well with experimental data, and the spectral red shifts of several main bands, in the 1200 cm-1-1800 cm-1 range, are sensitive to the strength of the metal-ligand interaction and to the spin state of the ion. Due to the rigidity of those complexes, first principles molecular dynamics calculations provide spectra similar to that produced by static calculations that are already able to catch the main spectral signatures using harmonic calculations at the B3LYP/6-31G* level.
Collapse
Affiliation(s)
- N Nieuwjaer
- Université Sorbonne Paris Nord, Lab. de Physique des Lasers, CNRS, 93430 Villetaneuse, France
| | - A Beydoun
- Université Sorbonne Paris Nord, Lab. de Physique des Lasers, CNRS, 93430 Villetaneuse, France
| | - F Lecomte
- Université Sorbonne Paris Nord, Lab. de Physique des Lasers, CNRS, 93430 Villetaneuse, France
| | - B Manil
- Université Sorbonne Paris Nord, Lab. de Physique des Lasers, CNRS, 93430 Villetaneuse, France
| | - F Cappelluti
- University of L'Aquila, Department of Information Engineering, Computer Science and Mathematics, 67100 L'Aquila, Italy
| | - L Guidoni
- University of L'Aquila, Department of Physical and Chemical Sciences, 67100 L'Aquila, Italy
| | - D Scuderi
- Université Paris Saclay, Institut de Chimie Physique, UMR 8000 CNRS, 91400 Orsay, France
| | - C Desfrançois
- Université Sorbonne Paris Nord, Lab. de Physique des Lasers, CNRS, 93430 Villetaneuse, France
| |
Collapse
|
2
|
Palma A, Grande S, Ricci-Vitiani L, Luciani A, Buccarelli M, Biffoni M, Molinari A, Calcabrini A, D’Amore E, Guidoni L, Pallini R, Viti V, Rosi A. 307. Metabolic heterogeneity among Glioblastoma stem-like cells reflects differences in response to drug treatments. Phys Med 2018. [DOI: 10.1016/j.ejmp.2018.04.316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
3
|
Campetella M, Bovi D, Caminiti R, Guidoni L, Bencivenni L, Gontrani L. Structural and vibrational study of 2-MethoxyEthylAmmonium Nitrate (2-OMeEAN): Interpretation of experimental results with ab initio molecular dynamics. J Chem Phys 2016; 145:024507. [DOI: 10.1063/1.4956459] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M. Campetella
- Dipartimento di Chimica, Università di Roma, “La Sapienza,” P. le Aldo Moro 5, I-00185 Roma, Italy
| | - D. Bovi
- Dipartimento di Fisica, Università di Roma, “La Sapienza,” P. le Aldo Moro 5, I-00185 Roma, Italy
| | - R. Caminiti
- Dipartimento di Chimica, Università di Roma, “La Sapienza,” P. le Aldo Moro 5, I-00185 Roma, Italy
| | - L. Guidoni
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio, Coppito, I-67100 L’Aquila, Italy
| | - L. Bencivenni
- Dipartimento di Chimica, Università di Roma, “La Sapienza,” P. le Aldo Moro 5, I-00185 Roma, Italy
| | - L. Gontrani
- Dipartimento di Chimica, Università di Roma, “La Sapienza,” P. le Aldo Moro 5, I-00185 Roma, Italy
| |
Collapse
|
4
|
Harty TP, Allcock DTC, Ballance CJ, Guidoni L, Janacek HA, Linke NM, Stacey DN, Lucas DM. High-Fidelity Preparation, Gates, Memory, and Readout of a Trapped-Ion Quantum Bit. Phys Rev Lett 2014; 113:220501. [PMID: 25494060 DOI: 10.1103/physrevlett.113.220501] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Indexed: 06/04/2023]
Abstract
We implement all single-qubit operations with fidelities significantly above the minimum threshold required for fault-tolerant quantum computing, using a trapped-ion qubit stored in hyperfine "atomic clock" states of ^{43}Ca^{+}. We measure a combined qubit state preparation and single-shot readout fidelity of 99.93%, a memory coherence time of T_{2}^{*}=50 sec, and an average single-qubit gate fidelity of 99.9999%. These results are achieved in a room-temperature microfabricated surface trap, without the use of magnetic field shielding or dynamic decoupling techniques to overcome technical noise.
Collapse
Affiliation(s)
- T P Harty
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - D T C Allcock
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - C J Ballance
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - L Guidoni
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom and Laboratoire Matériaux et Phénomènes Quantiques, University of Paris Diderot, UMR 7162 CNRS, F-75205 Paris, France
| | - H A Janacek
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - N M Linke
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - D N Stacey
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - D M Lucas
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| |
Collapse
|
5
|
Fraschetti C, Montagna M, Guarcini L, Guidoni L, Filippi A. Spectroscopic evidence for a gas-phase librating G-quartet–Na+ complex. Chem Commun (Camb) 2014; 50:14767-70. [DOI: 10.1039/c4cc05149a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Na+–G4 adduct exists as a mixture of two metastable populations, rapidly interconverting at room temperature.
Collapse
Affiliation(s)
- C. Fraschetti
- Pharmaceutical Chemistry and Technologies
- Sapienza-University of Rome
- Rome, Italy
| | - M. Montagna
- Pharmaceutical Chemistry and Technologies
- Sapienza-University of Rome
- Rome, Italy
| | - L. Guarcini
- Pharmaceutical Chemistry and Technologies
- Sapienza-University of Rome
- Rome, Italy
| | - L. Guidoni
- Chemistry
- Chemical and Materials Engineering
- L'Aquila University
- 67100 L'Aquila, Italy
| | - A. Filippi
- Pharmaceutical Chemistry and Technologies
- Sapienza-University of Rome
- Rome, Italy
| |
Collapse
|
6
|
Bovi D, Guidoni L. Magnetic coupling constants and vibrational frequencies by extended broken symmetry approach with hybrid functionals. J Chem Phys 2012; 137:114107. [DOI: 10.1063/1.4752398] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
7
|
Didier P, Weiss E, Sibler AP, Philibert P, Martineau P, Bigot JY, Guidoni L. Femtosecond spectroscopy probes the folding quality of antibody fragments expressed as GFP fusions in the cytoplasm. Biochem Biophys Res Commun 2007; 366:878-84. [PMID: 18067857 DOI: 10.1016/j.bbrc.2007.11.141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Accepted: 11/23/2007] [Indexed: 12/25/2022]
Abstract
Time-resolved femtosecond spectroscopy can improve the application of green fluorescent proteins (GFPs) as protein-folding reporters. The study of ultrafast excited-state dynamics (ESD) of GFP fused to single chain variable fragment (scFv) antibody fragments, allowed us to define and measure an empirical parameter that only depends on the folding quality (FQ) of the fusion. This method has been applied to the analysis of genetic fusions expressed in the bacterial cytoplasm and allowed us to distinguish folded and thus functional antibody fragments (high FQ) with respect to misfolded antibody fragments. Moreover, these findings were strongly correlated to the behavior of the same scFvs expressed in animal cells. This method is based on the sensitivity of the ESD to the modifications in the tertiary structure of the GFP induced by the aggregation state of the fusion partner. This approach may be applicable to the study of the FQ of polypeptides over-expressed under reducing conditions.
Collapse
Affiliation(s)
- P Didier
- Faculté de Pharmacie, UMR 7175, 74, route du Rhin, 67412 Illkirch, France
| | | | | | | | | | | | | |
Collapse
|
8
|
Milman P, Maineult W, Guibal S, Guidoni L, Douçot B, Ioffe L, Coudreau T. Topologically decoherence-protected qubits with trapped ions. Phys Rev Lett 2007; 99:020503. [PMID: 17678207 DOI: 10.1103/physrevlett.99.020503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Indexed: 05/16/2023]
Abstract
We show that trapped ions can be used to simulate a highly symmetrical Hamiltonian with eigenstates naturally protected against local sources of decoherence. This Hamiltonian involves long-range coupling between particles and provides a more efficient protection than nearest neighbor models discussed in previous works. Our results open the perspective of experimentally realizing, in controlled atomic systems, complex entangled states with decoherence times up to 9 orders of magnitude longer than isolated quantum systems.
Collapse
Affiliation(s)
- P Milman
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS UMR 7162, Université Denis Diderot, 2 Place Jussieu, 75005 Paris, France
| | | | | | | | | | | | | |
Collapse
|
9
|
Grande S, Luciani AM, Rosi A, Palma A, Giovannini C, Sapora O, Guidoni L, Viti V. Metabolism of glutathione in tumour cells as evidenced by 1H MRS. FEBS Lett 2007; 581:637-43. [PMID: 17257597 DOI: 10.1016/j.febslet.2007.01.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 01/11/2007] [Accepted: 01/12/2007] [Indexed: 11/24/2022]
Abstract
1H MRS signals of glutathione and of free glutamate were examined in samples from cultured tumour cells, namely MCF-7 from mammary carcinoma and TG98 from malignant glioma, with the aim of relating signal intensities to aspects of GSH metabolism. Spectra of cells harvested at different cell densities suggest that GSH and glu signal intensities are related to cell density and proliferation and their ratio is dependent on the activity of the gamma-glutamyl cysteine synthetase. The hypothesis is confirmed by experiments performed on cells treated with buthionine sulfoximine that inhibits the enzyme activity.
Collapse
Affiliation(s)
- S Grande
- Dipartimento Tecnologie e Salute and INFN Gruppo Collegato Sanita', Istituto Superiore di Sanita', Viale Regina Elena 299, 00161 Roma, Italy
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Grande S, Giovannini C, Guidoni L, Luciani AM, Palma A, Rosi A, Sapora O, Viti V. 1H MRS signals from glutathione may act as predictive markers of apoptosis in irradiated tumour cells. Radiat Prot Dosimetry 2006; 122:205-6. [PMID: 17251247 DOI: 10.1093/rpd/ncl391] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Inhibition of apoptosis in tumour cells may depend on intracellular reduced glutathione (GSH) level. In this work, GSH levels were studied by (1)H MRS in MCF-7 and HeLa cells, characterised by a different radiosensitivity. Annexin-V test showed that the fraction of apoptotic HeLa cells after irradiation is much higher than in control, although MCF-7 cells did not show a significant apoptosis. MRS signals from GSH (G) show lower intensity in HeLa with respect to MCF-7 cells; the opposite is true for free glutamic acid [glu (g)]. After irradiation, the G/g ratio decreases in MCF-7, although remaining approximately constant in HeLa cells. Buthionine sulfoximine (BSO) treated MCF-7 cells show an increase in the percentage of apoptotic cells; in parallel, G/g ratio behaves as in HeLa. This study indicates that GSH level may act as predictive marker of apoptosis by irradiation.
Collapse
Affiliation(s)
- S Grande
- Department of Technology and Health and INFN Sanità Group, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy
| | | | | | | | | | | | | | | |
Collapse
|
11
|
de Pasquale F, Barone P, Sebastiani G, d'Errico F, Egger E, Luciani AM, Pacilio M, Guidoni L, Viti V. Ion diffusion modelling of Fricke-agarose dosemeter gels. Radiat Prot Dosimetry 2006; 120:151-4. [PMID: 16644939 DOI: 10.1093/rpd/nci683] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In Fricke-agarose gels, an accurate determination of the spatial dose distribution is hindered by the diffusion of ferric ions. In this work, a model was developed to describe the diffusion process within gel samples of finite length and, thus, permit the reconstruction of the initial spatial distribution of the ferric ions. The temporal evolution of the ion concentration as a function of the initial concentration is derived by solving Fick's second law of diffusion in two dimensions with boundary reflections. The model was applied to magnetic resonance imaging data acquired at high spatial resolution (0.3 mm) and was found to describe accurately the observed diffusion effects.
Collapse
Affiliation(s)
- F de Pasquale
- Istituto per le Applicazioni del Calcolo, CNR, viale del Policlinico 137, 00161 Rome, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Viti V, d'Errico F, Pacilio M, Luciani AM, Palma A, Grande S, Ranghiasci C, Adorante N, Guidoni L, Rosi A, Ranade M, de Pasquale F, Barone P, Sebastiani G. Optical imaging of dose distributions in Fricke gels. Radiat Prot Dosimetry 2006; 120:148-50. [PMID: 16614085 DOI: 10.1093/rpd/ncj005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ferrous-sulphate infused gels, or 'Fricke gels', encounter great interest in the field of radiation dosimetry, due to their potential for 3D radiation dose mapping. Typically, magnetic resonance (MR) relaxation rates are determined in these systems in order to derive the absorbed dose. However, when large concentration gradients are present, diffusion effects before and during the MR imaging may not be negligible. In these cases, optical techniques may represent a viable alternative. This paper describes research aimed at measuring 3D dose distributions in a Fricke-xylenol orange gel by measuring optical density with a CCD camera. This method is inexpensive and fast. A series of early experiments is described, in which optical density profiles were measured with a commercial microdensitometer for film dosimetry. The light box of the device was modified to work at 567 nm, close to the maximum absorbance of the ferric ion-xylenol orange complex. Under these conditions, the gel shows linearity with dose and high sensitivity.
Collapse
Affiliation(s)
- V Viti
- Yale University School of Medicine, New Haven, CT 06510, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Grande S, Giovannini C, Luciani AM, Palma A, Rosi A, Sapora O, Viti V, Guidoni L. Radiation effects in cultured tumour cells examined by 1H MRS: mobile lipids modulation and proliferative arrest. Radiat Prot Dosimetry 2006; 122:202-4. [PMID: 17158120 DOI: 10.1093/rpd/ncl517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Much attention has been devoted in the past to monitor changes of mobile lipid (ML) (1)H MRS signals in spectra of tumour cells. The purpose of this work is to exploit ML signals to provide information on cell metabolism after irradiation, comparing tumour cells characterised by different radiosensitivity and relating MRS findings to changes in cell proliferation and delays in cell cycle phases. Irradiated HeLa cells present less intense ML signals with respect to controls. The opposite is true for MCF-7 cells. A G(2) arrest is observed for both cell lines after irradiation. In HeLa cells, G(1) decreases and S phase is maintained; a sub G(1) peak is also visible. In MCF-7 cells, G(1) is decreased and S phase is strongly reduced, while no sub G(1) is present. The observed changes in ML are tentatively associated to cell cycle regulation of phospholipid synthesis. Mathematical modelling of ML variations is in progress.
Collapse
Affiliation(s)
- S Grande
- Department of Technology and Health and INFN Sanità Group, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Luciani AM, Palma A, Adorante N, Barone P, Grande S, Ranghiasci C, Rosi A, Guidoni L, Viti V. Optical images of dose distributions in Gel-Fricke: dosimetric performances of the gel. Radiat Prot Dosimetry 2006; 122:455-6. [PMID: 17186949 DOI: 10.1093/rpd/ncl486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The purpose of this work was to examine the dosimetric performances of the radiochromic Fricke-Agarose-Xylenol Orange gel by optical measurements in order to perform dose reconstructions, in view of a future development for 3-D maps. Optical images and dose-response curves of the gel were obtained by a CCD-based device, originally designed for reading radiochromic films, that was modified to meet the optical properties of the dosemeter. With a resolution of 0.18 x 0.18 mm the optimum range of doses in which per cent uncertainty is lower than 2% was 3-10 Gy. The minimum detectable dose, estimated as the absorbed dose corresponding to 3 SD above background, was 0.1 Gy. With a resolution of 1.98 x 1.98 mm the optimum range of doses in which per cent uncertainty is lower than 2% was 0.3-10 Gy. The minimum detectable dose, estimated as the absorbed dose corresponding to 3 SD above background, was 0.015 Gy. The comparison with alanine dosemeters in the dose range 7-10 Gy showed agreement within a few per cent and the same agreement was observed for the comparison with TLD in the range 1-3 Gy.
Collapse
Affiliation(s)
- A M Luciani
- Department of Technology and Health and INFN Sanità Group, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Didier P, Guidoni L, Bardou F. Infinite average lifetime of an unstable bright state in the green fluorescent protein. Phys Rev Lett 2005; 95:090602. [PMID: 16197199 DOI: 10.1103/physrevlett.95.090602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Indexed: 05/04/2023]
Abstract
The time evolution of the fluorescence intensity emitted by well-defined ensembles of green fluorescent proteins has been studied by using a standard confocal microscope. In contrast with previous results obtained in single-molecule experiments, the photobleaching of the ensemble is well described by a model based on Lévy statistics. By assuming the presence of thermally activated barriers, this simple model allows us to obtain information about their height distribution.
Collapse
Affiliation(s)
- P Didier
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS-ULP-ECPM, 23 rue du Loess, B.P. 43, F-67034 Strasbourg CX, France.
| | | | | |
Collapse
|
16
|
Vomir M, Andrade LHF, Guidoni L, Beaurepaire E, Bigot JY. Real space trajectory of the ultrafast magnetization dynamics in ferromagnetic metals. Phys Rev Lett 2005; 94:237601. [PMID: 16090502 DOI: 10.1103/physrevlett.94.237601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2004] [Indexed: 05/03/2023]
Abstract
We have measured the real space trajectory of the ultrafast magnetization dynamics in ferromagnetic metals induced by femtosecond optical pulses. Our approach allows the observation of the initial change of the modulus and orientation of the magnetization, occurring within a few hundreds of femtoseconds, as well as its subsequent precession and damping around the effective field. The role of the magnetocrystalline anisotropy shows up in the magnetization reorientation occurring during the electron-lattice relaxation. In addition, we propose a model which takes into account the initial demagnetization in the Bloch formalism describing the magnetization dynamics.
Collapse
Affiliation(s)
- M Vomir
- Institut de Physique et Chimie des Matériaux de Strasbourg, Unité Mixte 7504 CNRS, Université Louis Pasteur BP. 43, 23 rue du Loess, 67034 Strasbourg Cedex, France
| | | | | | | | | |
Collapse
|
17
|
Abstract
A new method to measure and analyze the time and spectrally resolved polarimetric response of magnetic materials is presented. It allows us to study the ultrafast magnetization dynamics of a CoPt3 ferromagnetic film. The analysis of the pump-induced rotation and ellipticity detected by a broad spectrum probe beam shows that magneto-optical signals predominantly reflect the spin dynamics in ferromagnets.
Collapse
Affiliation(s)
- J-Y Bigot
- Institut de Physique et Chimie des Matériaux de Strasbourg, Unité Mixte CNRS-ULP-ECPM, 23 rue du Loess, B.P. 43, 67034 Strasbourg Cedex, France.
| | | | | | | |
Collapse
|
18
|
Didier P, Guidoni L, Schwalbach G, Bourotte M, Follenius-Wund A, Pigault C, Bigot JY. Ultrafast gain dynamics of the green fluorescent protein. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(02)01379-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
19
|
Grande S, Luciani AM, Rosi A, Cherubini R, Conzato M, Guidoni L, Viti V. Radiation effects on soluble metabolites in cultured HeLa cells examined by 1H MRS: changes in concentration of glutathione and of lipid catabolites induced by gamma rays and proton beams. Int J Cancer 2002; 96 Suppl:27-42. [PMID: 11992384 DOI: 10.1002/ijc.10345] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cultured HeLa cells were irradiated with a single acute dose of either gamma rays (40 Gy) or low-energy proton beams (20 Gy). (1)H magnetic resonance spectra of intact cells harvested at different times after irradiation and of the correspondent perchloric acid (PCA) extracts prepared at different times after irradiation were run. Selected signals from glutathione and lactate were examined with the aim of investigating effects of irradiation on antioxidative stores and on mitochondrial activity. An increase of signal intensity of glutathione (GSH) takes place at 15 and 24 hr after irradiation, while a decrease of its signal intensity, accompanied by an increase of that of free glutamate, starts appearing 48 hr after irradiation. Lactate signal increases 48 hr after irradiation. Signals from lipid catabolites were also examined to explore their sensitivity in predicting the response to radiotherapy. Intensity ratios of signals of glycerophosphorylcholine and choline to that of phosphorylcholine increase with time after irradiation. Irradiating cells with gamma rays or proton beams at half a dose produces effects comparable to the metabolic variations presented here. The present experiments allow more insight into the complex pattern of the changes of GSH by irradiation and indicate that magnetic resonance spectroscopy signals from GSH, glutamate, lactate, and lipid catabolites are affected by irradiation. Finally, these data represent a first indication that the relative biological efficiency for some metabolic damage of low-energy proton beams with respect to gamma rays can reach a value of 2.
Collapse
Affiliation(s)
- S Grande
- Laboratorio di Fisica and Istituto Nazionale di Fisica Nucleare Gruppo Collegato Sanità, Istituto Superiore di Sanità, 00161 Roma, Italy
| | | | | | | | | | | | | |
Collapse
|
20
|
Luciani AM, Rosi A, Grande S, Guidoni L, Viti V, Cherubini R, Conzato M. Changes in soluble metabolites induced in tumour cells by gamma rays and proton beams: a 1H magnetic resonance spectroscopy study. Radiat Prot Dosimetry 2002; 99:307-310. [PMID: 12194313 DOI: 10.1093/oxfordjournals.rpd.a006791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cultured HeLa cells have been irradiated with a single acute dose of either gamma rays (40 Gy) or low energy proton beams (20 Gy). 1H magnetic resonance spectra of perchloric acid extracts (PCA) prepared at different times after irradiation show an intensity decrease of signal from glutathione and a parallel increase of lactate signal. Intensity ratios of signals of glycerophosphorylcholine to that of phosphorylcholine increase with time after irradiation. Irradiating cells with gamma rays or proton beams at half a dose obtain effects of comparable extent. The present experiments indicate that relevant metabolic alterations take place in cells damaged by irradiation. Finally, these data represent a first indication that the relative biological efficiency of low energy proton beams with respect to gamma rays can reach a value of 2 as evidenced by cell metabolic impairment.
Collapse
Affiliation(s)
- A M Luciani
- Lab. Fisica, Istituto Superiore di Sanità and INFN (RMI), Viale Regina Elena 299, 00161 Rome, Italy.
| | | | | | | | | | | | | |
Collapse
|
21
|
de Pasquale F, Luciani AM, Pacilio M, Guidoni L, Viti V, d'Errico F, Barone P, Sebastiani G. Dose reconstruction in irradiated Fricke-agarose gels by means of MRI and optical techniques: 2D modelling of diffusion of ferric ions. Radiat Prot Dosimetry 2002; 99:363-364. [PMID: 12194325 DOI: 10.1093/oxfordjournals.rpd.a006803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fricke-agarose gels have elicited much interest in the field of radiation dosimetry, as tissue-equivalent dosemeters. magnetic resonance (MR) relaxation rates are measured for dose reconstruction. A major problem of Fricke-agarose gels is the diffusion of the ferric ions formed after irradiation. Knowledge of the diffusion coefficient of ferric ions may be necessary. Xylene orange, a dye that specifically chelates ferric ions, was added to the Fricke gel system to reduce ion diffusion and, as the binding gives a coloured complex, to allow optical detection of ferric ions. Diffusion of ferric ions in two dimensions and time evolution of ion concentration were evaluated. MR images were obtained at different times after irradiation. Ferric ion distribution, the corresponding images and the doses at different times after irradiation were reconstructed taking into account the calculated diffusion coefficients. Diffusion was then estimated by means of two different optical methods. The agreement obtained supports the reliability of the MRI method and of the model.
Collapse
|
22
|
Luciani AM, Rosi A, Matarrese P, Arancia G, Guidoni L, Viti V. Changes in cell volume and internal sodium concentration in HeLa cells during exponential growth and following lonidamine treatment. Eur J Cell Biol 2001; 80:187-95. [PMID: 11302524 DOI: 10.1078/0171-9335-00102] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cell volumes decreased in HeLa cells as a function of time after seeding during exponential growth. Cell volume distributions revealed the presence of two cell populations in all stages of growth. When cells approached confluence, the ratio of the two populations abruptly shifted towards that characterised by the smallest volume. Percentages of G1-, S- and G2 + M-phase cells were also measured and it was found that G1 frequency increased as a function of cell density during exponential growth. Intracellular sodium concentration, [Na]i was monitored by 23Na NMR in the presence of 5 mM dysprosium (III) tripolyphosphate. [Na]i increased from 22.8 to 59.0 mM in cells from the second to the seventh day after seeding. Treatment with lonidamine, an antitumoral drug that it is known to slow down cell growth by affecting aerobic glycolysis, produced a complete block of cell progression after a few days of treatment. The progression of cell volume distributions towards smaller volumes and the increase in internal sodium concentration as a function of time after seeding were also affected by the drug. These phenomena were related to the existence of a subpopulation of mitotically inactive G1-phase cells during exponential growth, pointing out that a density-dependent cellular mechanism regulates the cell cycling in HeLa cells.
Collapse
Affiliation(s)
- A M Luciani
- Laboratorio di Fisica, Istituto Superiore di Sanitá, Roma, Italy
| | | | | | | | | | | |
Collapse
|
23
|
|
24
|
Guastadisegni C, Guidoni L, Balduzzi M, Viti V, Di Consiglio E, Vittozzi L. Characterization of a phospholipid adduct formed in Sprague Dawley rats by chloroform metabolism: NMR studies. J Biochem Mol Toxicol 2000; 12:93-102. [PMID: 9443066 DOI: 10.1002/(sici)1099-0461(1998)12:2<93::aid-jbt4>3.0.co;2-j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The formation of a covalent adduct to a single phospholipid by the oxidative chloroform metabolite, phosgene, is demonstrated in liver mitochondria of phenobarbital-pretreated Sprague Dawley (SD) rats treated with CHCl3. The densitometric analysis of the phosphorus stained extracted phospholipids showed that the formation of this adduct in liver mitochondria is accompanied by a decrease of phosphatidylethanolamine and cardiolipin. The characterization of this adduct was performed with a multinuclear NMR approach by comparison with the decreased phospholipids. Treatment of rats with [13C]chloroform resulted in an intense 13C NMR peak from either an esteric or amidic carbonyl. Very strong similarities in fatty acid composition were found between phosphatidylethanolamine and the phosgene-modified PL, using 13C and 1H NMR spectroscopy. A multiplet at 3.91 ppm coupled to a signal at 3.41 ppm was shown by two-dimensional 1H NMR in the adduct spectrum. This cross peak was interpreted as arising from the shifted resonances of the two PE head group methylene groups, due to the binding with phosgene. 31P spectrum of the adduct was identical to that of phosphatidylethanolamine. We concluded that the chloroform adduct is a modified phosphatidylethanolamine, with the phosgene-derived carbonyl bound to the amine of the head group.
Collapse
Affiliation(s)
- C Guastadisegni
- Laboratory of Environmental Hygiene, Istituto Superiore di Sanità, Rome, Italy
| | | | | | | | | | | |
Collapse
|
25
|
Abstract
Molecular dynamics simulations and electrostatic modeling are used to investigate structural and dynamical properties of the potassium ions and of water molecules inside the KcsA channel immersed in a membrane-mimetic environment. Two potassium ions, initially located in the selectivity filter binding sites, maintain their position during 2 ns of dynamics. A third potassium ion is very mobile in the water-filled cavity. The protein appears engineered so as to polarize water molecules inside the channel cavity. The resulting water induced dipole and the positively charged potassium ion within the cavity are the key ingredients for stabilizing the two K(+) ions in the binding sites. These two ions experience single file movements upon removal of the potassium in the cavity, confirming the role of the latter in ion transport through the channel.
Collapse
Affiliation(s)
- L Guidoni
- Istituto Nazionale per la Fisica della Materia, Italy and International School for Advanced Studies, Via Beirut 4, 34014 Trieste, Italy
| | | | | |
Collapse
|
26
|
de Pasquale F, Sebastiani G, Egger E, Guidoni L, Luciani AM, Marzola P, Manfredi R, Pacilio M, Piermattei A, Viti V, Barone P. Bayesian estimation of relaxation times T(1) in MR images of irradiated Fricke-agarose gels. Magn Reson Imaging 2000; 18:721-31. [PMID: 10930782 DOI: 10.1016/s0730-725x(00)00149-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The authors present a novel method for processing T(1)-weighted images acquired with Inversion-Recovery (IR) sequence. The method, developed within the Bayesian framework, takes into account a priori knowledge about the spatial regularity of the parameters to be estimated. Inference is drawn by means of Markov Chains Monte Carlo algorithms. The method has been applied to the processing of IR images from irradiated Fricke-agarose gels, proposed in the past as relative dosimeter to verify radiotherapeutic treatment planning systems. Comparison with results obtained from a standard approach shows that signal-to noise ratio (SNR) is strongly enhanced when the estimation of the longitudinal relaxation rate (R1) is performed with the newly proposed statistical approach. Furthermore, the method allows the use of more complex models of the signal. Finally, an appreciable reduction of total acquisition time can be obtained due to the possibility of using a reduced number of images. The method can also be applied to T(1) mapping of other systems.
Collapse
Affiliation(s)
- F de Pasquale
- Istituto per le Applicazioni del Calcolo, Consiglio Nazionale delle Ricerche, viale del Policlinico 137, Rome, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Pham TA, Barisien T, Grayer V, Guidoni L, Hadziioannou G, Bigot JY. Gain dynamics in oriented thin films of an oligo(para-phenylene vinylene). Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00048-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
28
|
|
29
|
Abstract
Changes in signal intensity of (1)H-MRS mobile lipids, mostly triglycerides, have been observed in cultured HeLa cells during exponential growth. Signals were intense in the first days after seeding and almost disappeared after a few days in culture. Choline-based metabolites were not affected by growth. Treatment with the antitumor drug lonidamine, which blocks cell proliferation and cell progression through cycle, increased lipid signal intensity. Morphological changes in the organization of the cell surface were detected by scanning electron microscopy during exponential growth, and were confirmed by freeze fracture analysis. The observed metabolic and structural modifications during cell growth were correlated to cell cycle progression of HeLa cells, as high-intensity lipid signals were typical of cells with a high percentage of S- and( )G(2) + M-phases, while cells with a high frequency in G(1)-phase were characterized by mobile lipid signals of very low intensity. Magn Reson Med 42:248-257, 1999.
Collapse
Affiliation(s)
- A Rosi
- Laboratorio di Fisica, Istituto Superiore di Sanitá, and INFN-Sezione Roma I, Gruppo collegato Sanitá, Rome, Italy
| | | | | | | | | | | |
Collapse
|
30
|
Abstract
Molecular dynamics simulations of the K+ channel from Streptomyces lividans (KcsA channel) were performed in a membrane-mimetic environment with Na+ and K+ in different initial locations. The structure of the channel remained stable and well preserved for simulations lasting up to 1.5 ns. Salt bridges between Asp80 and Arg89 of neighboring subunits, not detected in the X-ray structure, enhanced the stability of the tetrameric structure. Na+ or K+ ions located in the channel vestibule lost part of their hydration shell and diffused into the channel inner pore in less than a few hundred picoseconds. This powerful catalytic action was caused by strong electrostatic interactions with Asp80 and Glu71. The hydration state of the metal ions turned out to depend significantly on the conformational flexibility of the channel. Furthermore, Na+ entered the channel inner pore bound to more water molecules than K+. The different hydration state of the two ions may be a determinant factor in the ion selectivity of the channel.
Collapse
Affiliation(s)
- L Guidoni
- Scuola Internazionale Superiore di Studi Avanzati, Istituto Nazionale di Fisica della Materia, Trieste, Italy
| | | | | |
Collapse
|
31
|
Viti V, Ragona R, Guidoni L, Barone P, Furman E, Degani H. Hormonally induced modulation in the phosphate metabolites of breast cancer: analysis of in vivo 31P MRS signals with a modified prony method. Magn Reson Med 1997; 38:285-95. [PMID: 9256110 DOI: 10.1002/mrm.1910380219] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A modified Prony method (MPM) was applied to analyze the main signals present in spatially resolved 31P NMR spectra of MCF7 breast tumors implanted in nude mice. First, the method was tested on synthetic data to establish its limits of reliability. Its performance with respect to peak identification and quantification of signal intensities was then exploited on data from three implanted tumors during hormonal manipulation with estrogen and the antiestrogenic drug tamoxifen. The phosphomonoester peak was resolved into phosphocholine (PC) and phosphoethanolamine (PE). Treatment with tamoxifen led to a significant reduction in the PE to PE+PC peak amplitude ratio in the tumors under consideration. MPM analysis also revealed the presence of two different inorganic phosphate pools: a larger acidic pool and a smaller alkaline pool during estrogen-induced growth and the reverse during tumor regression.
Collapse
Affiliation(s)
- V Viti
- Laboratorio di Fisica e INFN Sez. Sanita, Istituto Superiore di Sanitá, Roma, Italy
| | | | | | | | | | | |
Collapse
|
32
|
Di Capua S, D'Errico F, Egger E, Guidoni L, Luciani AM, Rosi A, Viti V. Dose distribution of proton beams with NMR measurements of Fricke-agarose gels. Magn Reson Imaging 1997; 15:489-95. [PMID: 9223050 DOI: 10.1016/s0730-725x(96)00380-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Fricke-agarose gels have been irradiated with a proton beam. Then samples have been extracted at different depths with respect to the beam penetration distance, corresponding to different irradiation doses. Relaxation times T1 and T2, measured at 17 MHz, appear sensitive to this kind of radiation. In particular, T2 exhibits three components T2a, T2b and T2c, the first two being sensitive to proton irradiation. At 1% agarose concentration, the relaxation rates R1 = 1/T1, R2a = 1/T2a and R2b = 1/T2b of samples irradiated with both modulated and unmodulated beams, increase with the dose, irrespective of the beam energy. The yield G of Fe3+ ions per 100 eV of absorbed energy is always higher than that obtained for gamma irradiated samples.
Collapse
Affiliation(s)
- S Di Capua
- Laboratorio di Fisica e INFN Sezione Sanità, Istituto Superiore di Sanita', Roma Italy
| | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
NMR relaxation times T1 and T2 of agarose and Fricke agarose gels have been measured in the range 17-51 MHz. The analysis of the spin echo curves indicates a multiexponential behaviour, characterized by three components, at all the examined frequencies. The relative T2 values, ranging from a few to a hundred milliseconds, can be attributed to different species of water molecules present in the gel. Two of these components are characterized by relaxation rates R2a and R2b, more sensitive than R1 to gamma irradiation, the sensitivity S being S(R1) = 0.066 s-1 Gy-1, S(R2a) = 0.088 s-1 Gy-1, S(R2b) = 0.17 s-1 Gy-1. The three T2 values decrease as a function of frequency, but no gain in dose sensitivity is obtained by changing the working frequency in the examined range. The relaxivity of agarose gels containing ferrous or ferric ions has also been measured and found to be different from those of the corresponding solutions in the absence of agarose. Thus it was possible to estimate the irradiation yield from three independent parameters, R1, R2a and R2b. No effect of the dose rate or of the source energy has been observed for any of these parameters.
Collapse
Affiliation(s)
- A M Luciani
- Laboratorio di Fisica e INFN Sez, Sanità, Istituto Superiore di Sanità, Roma, Italy
| | | | | | | | | | | |
Collapse
|
34
|
Cacciafesta M, Ferri C, Carlomagno A, De Angelis C, Scuteri A, Guidoni L, Luciani AM, Rosi A, Viti V, Santucci A. Erythrocyte Na-K-Cl cotransport activity in low renin essential hypertensive patients. A 23Na nuclear magnetic resonance study. Am J Hypertens 1994; 7:151-8. [PMID: 8179850 DOI: 10.1093/ajh/7.2.151] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The Na-K-Cl cotransport activity in red blood cells from essential hypertensive men with low (n = 8, mean age 42 +/- 4 years) or normal renin activity (n = 4, mean age 43 +/- 3 years), and in normotensive men with normal renin activity (n = 7, mean age 38 +/- 4 years) has been evaluated by means of a recently developed 23Na nuclear magnetic resonance (NMR) method. Sodium efflux was determined by relating the resonating frequency of the NMR signal from extracellular sodium to sodium concentration in the presence of the shift reagent Dy(PPP)2(7-). The maximum Na+ efflux driven by cotransport (Vmax) was measured in Na(+)-loaded erythrocytes in the presence of ouabain to block the Na-K-Cl pump activity. A significant difference (P < 0.05) was found in Vmax values of low renin patients (0.70 mmol/h/L cells, range 0.40 to 0.90 mmol/h/L cells) as compared with normotensive controls (0.39 +/- 0.08 mmol/h/L cells) and normal renin hypertensives (mean 0.49 +/- 0.04 mmol/h/L cells). In conclusion, this study showed an increased activity of the Na-K-Cl cotransport in red blood cells from low renin hypertensive men as compared with normal renin hypertensives and normotensives.
Collapse
Affiliation(s)
- M Cacciafesta
- University La Sapienza, Institute of I Clinica Medica, Andrea Cesalpino Foundation, Rome, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Cacciafesta M, Ferri C, Carlomagno A, Piccirillo G, De Angelis C, Santucci A, Guidoni L, Luciani AM, Rosi A, Viti V. Increased sodium, potassium cotransport activity in salt-sensitive essential hypertensive patients. J Hypertens Suppl 1993; 11:S254-S255. [PMID: 8158371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- M Cacciafesta
- La Sapienza University, Andrea Cesalpino Foundation, Rome, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Cacciafesta M, Marigliano V, Ferri C, Piccirillo G, Scuteri A, Guidoni L, Luciani AM, Rosi A, Viti V. 23Na-NMR study of cation cotransport in human red blood cells. Am J Physiol 1992; 262:C1292-6. [PMID: 1590364 DOI: 10.1152/ajpcell.1992.262.5.c1292] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Na(+)-K+ cotransport in human erythrocytes from healthy subjects has been studied by means of 23Na-nuclear magnetic resonance (NMR) in the presence of the anionic paramagnetic shift reagent dysprosium (III) tripolyphosphate [Dy(PPP)2(7-)]. The intra- and extracellular 23Na-NMR signals were well separated, giving values of 6 +/- 1 mM for internal sodium concentration. Determination of the furosemide-sensitive Na+ efflux, in the presence of ouabain, was obtained by correlating the chemical shift variation of the external signal with changes in external Na+ concentration. For this purpose, calibration curves were generated. The values of the maximum efflux velocity (Vmax; 0.29-1 mmol.h-1.l cells-1) measured in 10 healthy adult male subjects were found to be within the range of values obtained by other authors. The NMR method proposed for the study of Na(+)-K+ cotransport is relatively simple and allows quick evaluation of cotransport Vmax values for a number of samples, being a good candidate for the study of this transport mechanism in the presence of different pathologies.
Collapse
Affiliation(s)
- M Cacciafesta
- Istituto di I Clinica Medica, Facoltà di Medicina e Chirurgia, Università di Roma La Sapienza, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Luciani AM, Rosi A, Maggiorella MT, Federico M, Sulli N, Verani P, Rossi GB, Viti V, Guidoni L. Interaction of HIV-1 with susceptible lymphoblastoid cells. 1H NMR studies. FEBS Lett 1991; 285:11-6. [PMID: 1712316 DOI: 10.1016/0014-5793(91)80713-d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Different strains of HIV susceptible lymphoblastoid cells have been infected by HIV-1 and examined by means of 1H NMR spectroscopy at different times after infection, taking advantage of the presence of high resolution lipid signals from the plasma membrane of tumor cells. A transient decrease in intensity of fatty acid signals, originated by changes in membrane structure, has been observed early after viral infection. Marked alterations in membrane-dependent steps of phospholipid synthesis can also be inferred by the observed transient depression in peaks from choline-based metabolites. Spectral modifications deriving from changes in lipid metabolism are also produced both in infected cells a few days after infection and in permanently infected cells. 1H NMR can, therefore, monitor structural and metabolic effects induced by HIV infection.
Collapse
Affiliation(s)
- A M Luciani
- Laboratorio di Fisica e INFN Sez. Sanita, Roma, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Ianzini F, Guidoni L, Simone G, Viti V, Yatvin MB. Effects of decreased pH on membrane structural organization of Escherichia coli grown in different fatty acid-supplemented media: a 31P NMR study. Arch Biochem Biophys 1990; 278:1-10. [PMID: 2181934 DOI: 10.1016/0003-9861(90)90223-l] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Total membranes from Escherichia coli cells grown in different fatty acid-supplemented media have been examined by 31P NMR at different pH values. The isolated inner and outer membranes were also studied and compared to the liposomes formed with the corresponding extracted lipids. While the liposomes show structures that are correlated with lipid composition, degree of fatty acid unsaturation, and pH, the membrane structure is mainly bilayer. The presence of two bilayer phases characterized by different chemical shift anisotropy values (delta nu csa) is detectable at neutral pH; a perturbation of the bilayer phase characterized by the smallest delta nu csa is produced by low pH. Moreover, an isotropic peak is always present in the membrane NMR spectra: its attribution to cardiolipin molecules is discussed on the basis of digestion experiments with phospholipase C.
Collapse
Affiliation(s)
- F Ianzini
- Laboratorio di Fisica, Istituto Superiore di Sanità, Rome, Italy
| | | | | | | | | |
Collapse
|
39
|
Ceccarini M, Guidoni L, Luciani AM, Mariutti G, Rosi A, Viti V. Biochemical and NMR studies on structure and release conditions of RNA-containing vesicles shed by human colon adenocarcinoma cells. Int J Cancer 1989; 44:714-21. [PMID: 2793243 DOI: 10.1002/ijc.2910440427] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Large amounts of particulate material, mostly lipid vesicles, are released by human colon adenocarcinoma HCT-8R cells when they are packed at high density in saline solution. RNA is also present in the released structures. Vesicle sheding is displayed only by healthy and viable cells. The process, in our experimental conditions, lasts up to 40 min, and can be restored by supplementing cells with nutrients and oxygen. RNA and lipids give rise to IH and 3IP NMR signals. The process is somehow related to a thermotropic transition observed by means of IH NMR spectroscopy for peculiar lipid domains in the plasma membrane. Analysis of 3IP NMR spectra of the phosphodiester groups, upon pH variation, indicates strong interaction between RNA and proteins in an assembled structure. A constant amount of polyA+ RNA can be recovered from the vesicles. The electrophoretic pattern and in vitro protein synthesis indicate that mRNA can be isolated as a functionally active molecule with a major 5 Kb fraction.
Collapse
Affiliation(s)
- M Ceccarini
- Laboratorio di Biologia Cellulare, Istituto Superiore di Sanità, Rome, Italy
| | | | | | | | | | | |
Collapse
|
40
|
Masella R, Cantafora A, Guidoni L, Luciani AM, Mariutti G, Rosi A, Viti V. Characterization of vesicles, containing an acylated oligopeptide, released by human colon adenocarcinoma cells. NMR and biochemical studies. FEBS Lett 1989; 246:25-9. [PMID: 2468527 DOI: 10.1016/0014-5793(89)80246-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
RNA-containing vesicles, recovered from the supernatant of high-density cell samples of human colon carcinoma, produce a high-resolution 1H NMR spectrum of lipids characterized by isotropic tumbling; these vesicles contain large amounts of triglycerides and cholesterol esters. Both findings have strict analogies to what is displayed by the proteolipid complexes isolated from the sera of tumor-bearing patients [(1985) Proc. Natl. Acad. Sci. USA 82, 3455-3459; (1986) FEBS Lett. 203, 164-168]. Lipid analysis and enzymatic tests indicate that these vesicles are selected micromaps of plasma membranes, analogous to those that can be recovered from culture media in which tumor cells are grown [(1985) Dev. Biol. 3, 33-57]. Peculiar lipids, an acylated oligopeptide and a modified phospholipid, are also present in the vesicles.
Collapse
Affiliation(s)
- R Masella
- Laboratorio di Metabolismo e Biochimica Patologica, Istituto Superiore di Sanità, Roma, Italy
| | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
Cultured cells from human colon adenocarcinoma spontaneously release structures which display an intense 31P NMR signal from RNA and mobile phospholipids. Furthermore, the DPH probe in the cell supernatant shows an intense fluorescence, thus indicating its insertion in lipid vesicles. The total membranes, prepared from the same cells, also release similar structures. The fatty acid chain signals from the mobile lipids, observable in the H NMR spectrum, and the fluorescence polarization of the DPH probe are strongly affected by RNAase digestion, thus indicating an association between RNA molecules and lipids. The enzymatic marker cytochrome c reductase was assayed to rule out possible contamination from endoplasmatic reticulum. A high alkaline phosphatase activity was instead found in the supernatant samples, thus indicating that the shed material is released by the plasma membrane.
Collapse
Affiliation(s)
- A Rosi
- Laboratorio di Fisica, Istituto Superiore di Sanitá, Roma, Italy
| | | | | | | | | |
Collapse
|
42
|
Abstract
An intense peak is visible in the phosphodiester region of the 31P NMR spectra of human colon adenocarcinoma HCT-8R cells. A signal at the same frequency, partially deriving from mobile phospholipids, is also observable in the spectra of total membranes and of perchloric acid extracts prepared from the same cells. The phosphodiester signals of glycerophosphorylcholine, glycerophosphorylethanolamine, and glycerophosphorylserine resonate at lower fields with respect to this broader peak and appear only in aged samples. Enzymatic treatments of the extracts would indicate that ribonucleic acid also contributes to the broad phosphodiester signal. Moreover, 1H NMR spectra show the presence of lipid structures, characterized by high mobility, in the cell and in the membrane samples, similar to what was already observed in other tumor cells and tissues.
Collapse
Affiliation(s)
- L Guidoni
- Laboratorio di Fisica, Istituto Superiore di Sanita, Rome, Italy
| | | | | | | | | |
Collapse
|
43
|
Albertini G, Fanelli E, Guidoni L, Ianzini F, Mariani P, Masella R, Rustichelli F, Viti V. Studies of structural modifications induced by γ-irradiation on distearoylphosphatidylcholine liposomes. Acta Crystallogr A 1987. [DOI: 10.1107/s0108767387084411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
44
|
Albertini G, Fanelli E, Guidoni L, Ianzini F, Mariani P, Masella R, Rustichelli F, Viti V. Studies of structural modifications induced by gamma-irradiation in distearoylphosphatidylcholine liposomes. Int J Radiat Biol Relat Stud Phys Chem Med 1987; 52:145-56. [PMID: 3496306 DOI: 10.1080/09553008714551571] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An investigation of the structural and thermodynamical modifications induced by gamma-irradiation in model membranes is reported. Differential scanning calorimetry and X-ray diffraction were used to study the different phases and associated transitions of distearoylphosphatidylcholine multilamellar liposomes after 60Co gamma-irradiation. Changes were observed in the shape of the calorimetric peaks and in the corresponding phase transition temperatures. In particular a shoulder was observed at about 20 kGy. The three phases characteristic of lecithins with identical acyl chains were detected also for the highest radiation dose. The formation of lysolecithin and stearic acid upon phospholipid degradation was observed. The lysolecithin concentration increases as a function of irradiation dose, until a saturation value is reached at 40 kGy. These results correlate quite well with those obtained for interlayer and interchain distances and for the width of the main phase transition calorimetric peak. At the highest dose (approximately equal to 80 kGy) cross-linked adjacent radicals and other molecular species are also formed. Appreciable differences, and some similarities, in the behaviour of DSPC and DPPC liposomes under gamma-irradiation were observed.
Collapse
|
45
|
Cantafora A, Ceccarini M, Guidoni L, Ianzini F, Minetti M, Viti V. Effects of gamma-irradiation on the erythrocyte membrane: ESR, NMR and biochemical studies. Int J Radiat Biol Relat Stud Phys Chem Med 1987; 51:59-69. [PMID: 3026982 DOI: 10.1080/09553008714550501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of gamma-irradiation on resealed erythrocyte ghosts have been examined with different techniques. Phospholipid analysis reveals peroxidative damage on the polyunsaturated chains of phosphatidylethanolamine. Gel electrophoresis and ESR measurements indicate modifications of the cytoskeletal proteins. 31P Nuclear magnetic resonance data show bilayer modifications that can be interpreted as changes in lipid-protein interactions. The overall picture from the present results favours interaction between lipids and proteins in the inner monolayer of the membrane.
Collapse
|
46
|
|
47
|
Albertini G, Fanelli E, Guidoni L, Ianzini F, Mariani P, Rustichelli F, Viti V. X-ray diffractometry and calorimetry studies of structural modifications induced by gamma-irradiation in phosphatidylcholine multilamellar liposomes. Int J Radiat Biol Relat Stud Phys Chem Med 1985; 48:785-96. [PMID: 3877016 DOI: 10.1080/09553008514551881] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Experimental results are reported on structural and thermodynamic modifications induced by gamma-irradiation in model membranes. Differential scanning calorimetry (DSC) and X-ray diffraction were used to study the different phases and associated transitions of dipalmitoylphosphatidylcholine after 60Co gamma-irradiation. Changes were observed in the shape of calorimetric peaks and in the corresponding enthalpy. The repetition distance of the layers increases while the distances related to the aliphatic chains decrease as a function of gamma-irradiation time. Moreover, an increase in the hexagonal symmetry with increasing dose was detected. No disappearance of a pre-transition was detected even at high doses.
Collapse
|
48
|
Guidoni L, Ianzini F, Indovina PL, Viti V. 1H- and 2H-n.m.r. studies of water in gamma-irradiated phosphatidylcholine multilamellar liposomes. Int J Radiat Biol Relat Stud Phys Chem Med 1985; 48:117-25. [PMID: 3874178 DOI: 10.1080/09553008514551121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
1H- and 2H-n.m.r. studies of gamma-irradiation-induced variations in the dynamic structure and proportional amounts of free, trapped and bound water species in multilamellar liposomes are reported and discussed. Bound water is shown to increase with dose and to be present in two different structural states. A dose-dependent decrease in the 1H-n.m.r. relaxation times of bound water following gamma-irradiation is reported. Variations are suggested as being due to large scale changes at the bilayer surface.
Collapse
|
49
|
Sapino A, Guidoni L, Bussolati G, Marchisio PC. Estrogen and tamoxifen induced cytoskeletal changes in breast cancer cells. Chemioterapia 1985; 4:243-5. [PMID: 4040818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The MCF-7 and CG-5 breast carcinoma cell lines were grown under different concentrations of estrogen and with or without the addition of tamoxifen to the media. Similar results were obtained with either cell lines. Cells cultured in estrogen-supplemented medium showed a marked change of the cell shape with the appearance of long projections sprouting from the cell body, adhesion areas being localized at the tips of these projections. A redistribution of bundles of prekeratin and actin fibres could be visualized by appropriate immuno-cytochemical procedures. Vimentin intermediate filaments and microtubules did not appear significantly modified by hormone conditioning. Tamoxifen treatment resulted in structural and cytoskeletal changes similar to those observed in estrogen stimulated cells. These data indicate that the shape and the cytoskeletal architecture of breast cancer cells can be conditioned by hormone treatment.
Collapse
|
50
|
Cicero R, Callari D, Guidoni L, Viti V, Scalia M, Maida I, Billitteri A, Sichel G. Effects of vitamin A in the presence of vitamins D3, E, K1 on red cell membrane structure. Z Naturforsch C Biosci 1984; 39:749-52. [PMID: 6093399 DOI: 10.1515/znc-1984-7-813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The incubation of erythrocyte ghosts with mixtures of vitamins A+D3, A+E, A+K1 produces decrease or increase of fluorescence anisotropy r of the DPH probe, depending on the vitamin/vitamin ratio. We found a correlation between the order parameter S and cell fusion phenomena observed by phase contrast microscopy.
Collapse
|