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Biomedical subjects

E Bucci

Publications and source records attributed to E Bucci.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Pigmented lesions of the oral cavity. II. Melanosis and melanoma].

The aetiopathogenetic and evolutive problem of primary oral melanoma is examined with particular regard for melanosis and its relationship with oral naevi. These lesions are classified differently by Authors with different opinions regarding their ability to turn malignant. In this regard, the latest and most reliable hypotheses on the subject are put forward.

Female↗
PubMed1989

[Clinico-statistical study and therapeutic approach to odontostomatological pathology in heart surgery patients].

After reporting some statistics, the procedures used in the dental treatment of the heart surgery patients subjected to anticlotting pharmacological treatment are described. Considering the considerable difficult in implementing the necessary pharmacological modifications and the high percentage of possible complications involved in these procedures, maximum interdisciplinary cooperation is recommended with heart surgery colleagues so as to carry out dental treatment in good time in patients who are candidates for heart and large vessel operations.

Adult↗
PubMed1989

[Physiopathology of the edentulous crest. Possibilities of the pharmacologic inhibition of pre- and post-operative bone resorption].

The biological causes of edentulous alveolar crest reabsorption are examined in the light of recent discoveries on the physiopathology of bone metabolism. The main techniques used for the classification of patients in terms of bone metabolism type are then described and the question of whether any currently available pharmacological treatment is capable of preparing for, supporting, preserving or even effectively replacing preprosthetic surgery is posed.

Alveolar Process↗
PubMed1988

Modulation of oxygen affinity in hemoglobin by solvent components. Interaction of bovine hemoglobin with 2,3-diphosphoglycerate and monatomic anions.

In the absence of Cl- in Hepes buffer at pH 7.4, the oxygen affinity of bovine and human hemoglobin is equally sensitive to 2,3-diphosphoglyceric acid. The low oxygen affinity measured for bovine hemoglobin at physiological salt concentration can be explained by the high affinity of Cl- anions for oxygen-linked sites that are absent in human hemoglobin. Bovine hemoglobin can discriminate between the different halogens in the sense that different halide concentrations are necessary to produce the same P50. Competition experiments indicate that the halogens interact with the same oxygen-linked sites. In agreement with the different affinities for halides, the Bohr effect of bovine hemoglobin is larger in the presence of Cl- than in that of Br- and there is good agreement between the number of protons and anions exchanged with the solvent upon oxygenation of bovine hemoglobin.

Animals↗
PubMed1988

Anisotropy decay of fluorescence as an experimental approach to protein dynamics.

This minireview makes an initial assessment of the progress made using anisotropy decay measurements for investigating the conformational changes and molecular dynamics in soluble systems. A critical analysis of available data is presented. The anisotropy decays of the tryptophan fluorescence of staphylococcal nuclease, adrenocorticotropin, melittin and of labeled transfer RNA were studied for investigating the functional conformational changes of these systems. The emissions of variously labeled immunoglobulins have been used to elucidate the conformations of these proteins before and after the binding of specific antibodies. Labeled myosin and its fragments have given information on the functional motions of the protein domains. The anisotropy decays of labeled and natural hemoglobin systems have been utilized for exploring the allosteric behavior of these molecules. The data suggest a wide applicability of this technique to the study of protein dynamics and conformational changes of macromolecules.

Immunoglobulins↗
PubMed1988

Resolution of the lifetimes and correlation times of the intrinsic tryptophan fluorescence of human hemoglobin solutions using 2 GHz frequency-domain fluorometry.

We used 2 GHz harmonic content frequency-domain fluorescence to measure the intensity and the anisotropy decays from the intrinsic tryptophan fluorescence from human hemoglobin (Hb). The tryptophan intensity decays are dominated by a short-lived component which accounts for 35-60% of the total steady state intensity. The decay time of this short component varies from 9 to 27 ps and this component is sensitive to the ligation state of Hb. Our error analyses indicate the uncertainty is about +/- 3 ps. The intensity decays also show two longer lived components near 0.7 and 8 ns, which are probably due either to impurities or to Hb molecules in conformations which do not permit energy transfer. The anisotropy decays indicate the tryptophan residues in Hb are highly mobile, with apparent correlation times near 55 ps.

Carboxyhemoglobin↗
PubMed1988

Time-resolved emission spectra of hemoglobin on the picosecond time scale.

We used front-face illumination to examine the steady-state and time-resolved emission from the intrinsic tryptophan emission of human hemoglobin (Hb). Experimental conditions were identified which eliminated all contributions of scattered light. The sensitivity obtained using front-face optics was adequate to allow measurement of the wavelength-dependent frequency response of the emission to 2 GHz. The intensity decays displayed pico- and nanosecond components in the emission at all wavelengths from 315 to 380 nm. The contribution of the picosecond component decreased from 72 to 37% over this range of wavelengths. Frequency-domain measurements were used to calculate the time-resolved emission spectra and decay-associated emission spectra. These spectra indicate that the picosecond components of the emission display maxima near 320 nm, whereas the nanosecond components are centered at longer wavelengths near 335 nm. The nanosecond components appear to be due to residual impurities which remain even in highly purified samples of Hb. However, we cannot eliminate the possibility that some of these components are due to Hb itself.

Hemoglobins↗
PubMed1988

Bovine hemoglobin as a basis for artificial oxygen carriers.

Under physiological conditions of pH and [Cl-] ions the oxygen affinity of bovine hemoglobin is lower than that of human hemoglobin. The difference tends to disappear at low ionic strength, while it increases at high ionic strength. In the presence of Cl- ions bovine hemoglobin is not sensitive to 2,3-DPG, while in the absence of Cl- ions human and bovine hemoglobin respond to 2,3-DPG in a similar way. This is due to a high preferential binding of halogens by the deoxy-conformation in the bovine system. Reaction of deoxy-bovine hemoglobin with 2,3-dibromo-salycyl-fumarate results in a decreased oxygen affinity. Compounds can be purified by anion exchange chromatography which have the sedimentation velocity of tetrameric hemoglobins. They fail to dissociate into dimers at acid pH because of the presence of intramolecular crosslinks. Reverse phase chromatography shows that both kind of subunits are modified by the reaction. The half time of retention in rats of these tetramers is near 5 h. Bovine red cells do not contain 2,3-DPG, therefore they can be stored in the cold in saline for at least 2 months without significant modifications of their oxygen affinity. The oxygen affinity of bovine red cells can be modulated by addition and subtraction of Cl- ions from and by changing the pH of the media.

2,3-Diphosphoglycerate↗