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Biomedical subjects

E Giovannini

Publications and source records attributed to E Giovannini.

At least 73 records · Page 4Linked to original sources
PubMed1980

[Mono-dimensional and bi-dimensional echocardiographic diagnosis of corrected transposition of the great vessels].

Three patients with corrected transposition of the great arteries (CTGA) have been studied by means of single plane (M-mode) and two-dimensional (2-D) echocardiography: the first study was performed after surgical closure of a VSD and the remaining two before cardiac catheterization. The following M-mode findings can suggest the diagnosis in CTGA: the interventricular septum (IVS) may not be visualized, there is lack of continuity between the posterior a-v valve (tricuspid) echoes and the anterior great artery (aorta), the posterior a-v valve leaflets may show some abnormalities in shape. The measurement of systolic time intervals of both semilunar valves can help in distinguishing the pulmonary artery from the aorta; further information can be obtained by means of peripheral venous contrast injection, which, in absence of right-to-left shunt, opacifies the posterior great vessel (pulmonary). The 2-D view of the heart allows the identification of the morphological type of ventricle and of the spatial great arteries relationship. The posteriorly and left located ventricle is recognized as morphologically right, because of the tricuspidal shape of its a-v valve: its attachment to IVS is lower than that of the mitral valve (4-chambers view) and three leaflets may be evident (short-axis); 3 papillary muscles and gross trabeculations can be identified (short axis and 4-chambers views, respectively). In long-axis the anterior vessel (aorta) runs parallel to the sternum; in short-axis both vessels are imaged as adjacent circles; by means of peripheral contrast injection, in conditions without right-to-left-shunt, the right and posterior vessel is recognized as a pulmonary artery. The differential diagnosis is discussed with d-transposition, Fallot's tetralogy, Taussig-Bing anomaly, common trunk, univentricular heart. According to our experience, the diagnosis of CTGA and associated defects can be made by M-mode and 2-D echocardiography.

Adult↗
PubMed1979

[Derivation of a velocity equation for a reaction model witwh two binding sites for acetylcholinesterase].

The authors suggest a kinetic model with two binding sites for acetylcholinesterase; it is suitable to study particular enzyme forms that show a kinetic pattern which cannot be explained by the model with a single binding site of Krupka and Laidler. The velocity equation was obtained using the algorithm of King and Altman and carrying out elementary calculations.

Acetylcholinesterase↗
PubMed1979

[Kinetic analysis of a reaction model with two binding sites for acetylcholinesterase].

After having suggested a kinetic model with two binding sites for acetylcholinesterase, the authors obtained the various function of [I] (1/vi; (vo/vi-1)/[I]; 1/Vi; Ki/Vi) starting from the velocity equation. An analytical study was then carried out showing the theoretical shape of such functions at different values of the kinetic parameters.

Acetylcholinesterase↗
PubMed1978

Erythrocyte acetylcholinesterase activity changes in the early stages of anemic and hypobaric hypoxia or after CoCl2 treatment in rabbits.

The authors studied the changes of erythrocyte acetylcholinesterase (AChE) activity in rabbits respectively subjected to bleeding, hypobaric hypoxia and CoCl2 treatment; in such conditions a rise of the enzyme activity was observed. Similar increases take place also as a consequence of intravenous infusions carried out by using lactic or hydrochloric acid. The authors suggest that these increases in the erythrocyte AChE activity are connected with the decrease of the pCO2 that occurs in the various experimental conditions achieved.

Acetylcholinesterase↗
PubMed1978

[The carotidogram in the diagnosis of the juxtavalvular fibrotic aortic stenosis. Report of 47 cases (author's transl)].

The morphological aspect of the carotid pulse has been under study in 47 cases of juxtavalvular aortic stenosis previously confirmed through hemodynamic and surgical examinations. The study included 39 cases of subvalvular fibrous stenosis (subaortic fibrous stenosis) (SAsV) and 8 cases of supravalvular annular aortic stenosis (S AsV). In 75% of both SAsV and SAsV cases the carotid pulse showed a rapid ascent and a finely notched apex, while in 25% of the cases it followed the pattern of a typical valvular stenosis. This is more obvious for the left carotid artery. The morphology of the carotid pulse resulted as independent from the aortic ventricular gradient, but, on the other hand, connected with the simultaneous stenotic involvement of the valvular cusps. The sign possesses not only high sensitivity but also high specificity with regard to juxtavalvular aortic stenoses because it has only been met with in 2 cases of valvular aortic stenosis. The pathophysiological explanation remains as yet obscure.

Adolescent↗
PubMed1978

Early effects of cobalt chloride treatment on certain blood parameters and on urine composition.

The authors studied the variations of some blood parameters and urine composition during the first hours after CoCl2 treatment in rats and rabbits. These showed an increase in hematocrit with a decrease in plasma volume and, at the same time, a decrease in total proteinemia as well as in the albumin (rabbits) and gamma-globulin fractions. On the basis of observations carried out in rabbits, these phenomena are not seen if the cobalt is complexed with cysteine before treatment; moreover, they are at least partly reversed by cysteine administration soon after cobalt. Plasma Na+ and K+ concentrations do not show significant changes in CoCl2-treated rabbits; on the contrary, the excretion of such electrolytes, as well as urinary protein content, decreases. In addition, the urine of CoCl2-treated rabbits contains at least two pigmented substances with different molecular weights, which are separable by dialysis and DEAE-cellulose chromatography and both contain cobalt in different percentages. The authors believe that CoCl2 treatment leads to an early and profound increase in vascular permeability with depletion of plasmatic material in the tissues and hemoconcentration; moreover, the above stated phenomena seem to be correlated with the forming of cobalt complexes.

Animals↗
PubMed1977

[Considerations on the diagnostic and therapeutic approach to hypertrophic subaortic stenosis (author's transl)].

Several physiopathological, diagnostic and therapeutic considerations have arisen from the observation of an operated case of hypertrophic subaortic stenosis associated with mitralic insufficiency and fibrosis of the interventricular septum. Keeping in mind the variability of the clinical pictures and the functional and anatomical factors which determine the clinical picture of the hypertrophic subaortic stenosis, it is concluded that a careful, unbiassed, clinical approach is necessary to determine the therapeutic procedure in each individual case.

Adult↗
PubMed1976

Activity of inhibitors on plasmatic erythropoietin and on the renal and splenic erythropoietic factors in the rabbit.

The author has studied the action of Cleland's reagent and Koshland's reagent on the erythropoietic factors present in the kidneys and the spleen of normal rabbits, in the plasma of bled rabbits and in the mixtures obtained through incubation of normal plasma with kidney and spleen homogenates. The results show that Cleland's reagent inhibits the activity of the renal and splenic erythro-stimulant factors, whereas it has no effect upon the erythropoietin in anaemic plasma and in plasma-kidney and plasma-spleen incubation mixtures. The activity of erythropoietin, on the other hand, is inhibited by Koshland's reagent, which has no influence on the renal and splenic erythro-stimulant factors.

2-Hydroxy-5-nitrobenzyl Bromide↗
PubMed1976

[Systolic time intervals in obstructive hypertrophic cardiomyopathy. The effects of adrenergic beta-stimulation and beta-blockade in 38 cases (author's transl)].

The authors report on the behaviour of systolic time intervals, studied with a noninvasive poligraphic technique, under normal conditions, after adrenergic beta stimuls (orciprenaline) and successive beta blocker (pindolole) in 38 patients with obstructive cardiomyopathy. Under normal conditions, the authors observed a marked dispersion of PEP and TEVS data, which have, however, average normal values. The IPEP was reduced in 29% of cases, was normal in 47.3% and raised in 23.7%; the ITEVS was reduced in 55.2% of cases, was normal in 21.1%, raised in 23.7%; the PEP/TEVS was reduced in 23.7%, normal in 31.6% and raised in 44.7%. The beta stimulation demonstrated a number of behaviour patterns: the most frequent cause was a reduction of PEP in the cases where it had been raised or where it had remained within normal limits, an increase of TEVS in the cases where it had been diminished or normal, a reduction of the PEP/TEVS correlation where these values were increased or normal. The beta blocker, followed by beta stimulus, brought on variations opposite from those of the beta stimulation. Thus, one can consider the hypothesis that the possible behaviour patterns and combination of PEP and TEVS result from different anatomical and functional expressions that can become obstructive cardiomyopathy, according to the seriousness of the obstruction, the ventricular compliance and the contractility.

Adult↗
PubMed1975

The subcellular localization of the erythrostimulant factors present in the kidney and spleen of the rabbit.

The subcellular localization of erythrostimulant factors contained in the kidney and spleen of the rabbit have been studied. This was done by subjecting homogenates to fractionation by centrifugation and assessing the erythrostimulant capacity of the hypotonic extracts prepared from the various fractions thus obtained. The results of these studies show that the erythrostimulant factors are present in the light mitochondrial and microsomal fractions of the normal kidney. In conditions of anaemia they are to be found not only in the above-mentioned fractions but also in the mitochondrial fraction. By contrast, in the spleen such factors are present only in the mitochondrial fraction. It is likely that the different localization of the erythrostimulant factors in the kidney and in the spleen of the rabbit may be closely connected with the different functions performed by these organs in the humoral regulation of erythropoiesis.

Animals↗