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Biomedical subjects

E Bevilacqua

Publications and source records attributed to E Bevilacqua.

41 records · Page 3Linked to original sources
PubMedDate not supplied

Deadtime correcton in high count rate quantitative dynamic studies with computer-assisted Anger-cameras.

The use of tracers with high radioactivity in rapid dynamic quantitative studies (such as radioisotope angiocardiography), performed by the Anger-camera and data-processor, makes it possible to obtain a high counting ratemfor correct interpretation of the results of the analysis of activity/time curves in regions of interest, the authors determined, under different working conditions, the deadtimes of two Anger-cameras (Pho-gamma HP and Radicamera II), both connected to a data-processing system (Med-II). The problems inherent in this determination are analyzed and discussed. A computer program for curve correction was written and some examples of applications of it are presented, including an experiment to test the accuracy of the correction.

Angiocardiography↗
PubMedDate not supplied

The role of the neutral amino acid transporter SNAT2 in cell volume regulation.

Sodium-dependent neutral amino acid transporter-2 (SNAT2), the ubiquitous member of SLC38 family, accounts for the activity of transport system A for neutral amino acids in most mammalian tissues. As the transport process performed by SNAT2 is highly energized, system A substrates, such as glutamine, glycine, proline and alanine, reach high transmembrane gradients and constitute major components of the intracellular amino acid pool. Moreover, through a complex array of exchange fluxes, involving other amino acid transporters, and of metabolic reactions, such as the synthesis of glutamate from glutamine, SNAT2 activity influences the cell content of most amino acids, thus determining the overall size and the composition of the intracellular amino acid pool. As amino acids represent a large fraction of cell organic osmolytes, changes of SNAT2 activity are followed by modifications in both cell amino acids and cell volume. This mechanism is utilized by many cell types to perform an effective regulatory volume increase (RVI) upon hypertonic exposure. Under these conditions, the expression of SNAT2 gene is induced and newly synthesized SNAT2 proteins are preferentially targeted to the cell membrane, leading to a significant increase of system A transport Vmax. In cultured human fibroblasts incubated under hypertonic conditions, the specific silencing of SNAT2 expression, obtained with anti-SNAT2 siRNAs, prevents the increase in system A transport activity, hinders the expansion of intracellular amino acid pool, and significantly delays cell volume recovery. These results demonstrate the pivotal role played by SNAT2 induction in the short-term hypertonic RVI and suggest that neutral amino acids behave as compatible osmolytes in hypertonically stressed cells.

Adaptation, Physiological↗
PubMedDate not supplied

[Nitrate derivatives in heart failure: physiopathological, clinical, and prognostic features].

The authors make a review about the indications and benefits of the use of nitrates in the treatment of acute and chronic cardiac failure, considering their use for a short and a long period. The advantages are reported, showing the reduction of pulmonary capillary wedge pressure and the increase of systolic output and consequently of the cardiac eject. This effect may be traceable both to the benefic effect on the mitral valve (perhaps incontinent), that in the pericadic "contraist". The reduction of the filling pressures increases the tolerance to the effort, delays the choice of the time for cardiac transplant and prolongs the survival with amelioration.

Heart Failure↗