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Biomedical subjects

G Valensin

Publications and source records attributed to G Valensin.

44 records · Page 3Linked to original sources
PubMed1982

1H-NMR relaxation investigation of water bound to bovine rod outer segment disk membranes.

Spin-lattice relaxation times T(1) in deuterated aqueous dispersions of lecithin and rod outer segment disk membranes were measured at various concentrations and temperatures. Fast chemical exchange between two loosely defined phases of water molecules was shown to fit the data, allowing the dynamic features of "bound" water and the hydration of the biological membrane to be evaluated. The state of the water was shown to be also involved in vision physiology.

Animals↗
PubMed1982

Virus-cell interactions: nuclear magnetic resonance behaviour of intracellular water.

The water proton NMR spin-lattice relaxation time if measured in HEp-2 cells in relation to the infection by different viruses (Poliovirus type 1, Coxsackievirus B-3, human Adenovirus, Measles virus, Respiratory Syncytial virus, Herpes simplex virus, subtype 1, and Vaccinia virus). The NMR properties of intracellular water allow the early detection and identification of viruses. A close relationship is shown between the NMR behavior and the mode of virus-cell interaction.

Adsorption↗
PubMed1981

Effect of morphine analogues on the conformational state of polyriboadenylic acid in solution: an NMR study.

The interaction of morphine analogues with polyadenylic acid in aqueous solution at pH 7 has been investigated. The NMR spectra measured at several temperatures were shown to give evidence of a lowering of the transition temperature from the helix to the random-coil structure. The measured chemical shifts and relaxation times were interpreted in terms of an ionic interaction between the + N - CH3 group of the drug and phosphate residue of the polynucleotide.

Magnetic Resonance Spectroscopy↗
PubMed1979

The water proton spin-lattice relaxation times in virus-infected cells.

The water proton spin-lattice relaxation times in HEp-2 cell cultures were determined immediately after 1 h of polio-virus adsorption. The shortening of the water T1 was closely related to the multiplicity of infection, allowing direct inspections of the virus--cell interaction since the first steps of the infectious cycle. Virus-induced structural and conformational changes of cell constituents were suggested to be detectable by NMR investigation of cell water.

Carcinoma, Squamous Cell↗
PubMed1975

Co-ordination behaviour of nucleic acid bases against the Fe(I)(NO)-2 group in solution. I. Purines: ESR study.

The binding sites of purine bases in the presence of the Fe(I)(NO)-2 group were investigated on the basis of the nuclear hyperfine structure of the electron spin resonance spectra. Selective isotopic substitution with 15-NO was used to clarify co-ordindination. Coupling constants and different types of complexes were determined by means of computer-simulated ESR spectra. Comparison was made with the binding sites of nucleotides and it was concluded that N-7, in the imidazole ring, is the preferred binding site. A structure with two base molecules bonded to the iron atom was proposed. Finally 8-azaguanine, an antitumoral agent, was studied and the special behaviour of this antimetabolite was demonstrated in the biologically-interesting pH values.

Azaguanine↗