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Biomedical subjects

P Valenti

Publications and source records attributed to P Valenti.

At least 145 records · Page 8Linked to original sources
PubMed1982

Xanthone analogues of clofibrate / Synthesis and biological evaluation as antagonists of lipolysis in vitro.

By appropriate superimposing of fenofibrate and fenofibric acid molecules, two xanthone derivatives (closed models) may be obtained. These compounds as well as their four chlorine-free isomers were prepared and tested on adrenaline- and theophylline-induced lipolysis in rat fat cells in comparison with ethyl 2-(4-chlorophenoxy)-2-methylpropionate (clofibrate). Some of these new derivatives besides being good inhibitors of adrenaline effect, as clofibrate is, were also very active in reducing theophylline-induced lipolysis. Very promising for further studies is the chlorine-free 3-isomer (3e). The possible difference in the action mechanism of these compounds as compared with clofibrate and the structure-activity relationships are briefly discussed.

Adipose Tissue↗
PubMed1981

Resistance of genus Proteus to ovotransferrin.

A total of 100 strains of Proteus, clinically isolated, were tested for sensitivity to ovotransferrin and CrCl3. Only a minority of the tested strains were not capable of growing in the presence of these iron chelating substances. Significant differences in the resistance among the four species of Proteus were noticeable only by addition to the culture medium of CrCl3 5 mM. The fact that sensitive strains were capable of growing after addition of citrate to culture medium containing ovotransferrin or CrCl3 suggests the presence in the genus Proteus of a citrate-dependent iron transport system.

Chlorides↗
PubMed1980

Capacity of staphylococci to grow in the presence of ovotransferrin or CrCl3 as a character of potential pathogenicity.

A total of 150 strains of staphylococci, clinically isolated, were tested for sensitivity to ovotransferrin (conalbumin). Among these, all the 50 coagulase-positive, mannitol-positive, and deoxyribonuclease-positive staphylococci appeared to be resistant to conalbumin, i.e., capable of growing in the presence of this transferrin. Among the other 100 strains, which were not classified as S. aureus, some appeared to be resistant and some were sensitive. The different behavior toward conalbumin is related to varying degrees of efficiency of the bacterial iron transport systems and, to test this, a simple method can be used, based on the addition of CrCl3 to the culture medium. The precipitation of iron produced by chromium salts has an effect on the growth of staphylococci similar to that produced by conalbumin and reveals the differences in the iron transport systems which occur in the genus Staphylococcus.

Biological Transport↗
PubMed1980

Separation by affinity chromatography of human very low and low density lipoproteins inhibiting Sindbis virus haemagglutination.

The haemagglutination-inhibiting activity of human serum towards Sindbis virus is linked to very low and low density lipoprotein classes, in particular to their lipid component. To investigate the specific role played in this inhibition by carbohydrates contained in the molecule, inhibitor separation was carried out by Concanavalin A-Sepharose affinity chromatography. A different behaviour among the inhibiting molecules in relation to the carbohydrate content was observed. The importance of mannose for the biological activity of the inhibitor is discussed.

Carbohydrates↗
PubMed1980

[Action of nifedipine on effort tolerance and on the left ventricular function during exercise in patients suffering from angina pectoris (author's transl)].

The therapeutic action of Nifedipine (Ni) and some of its haemodynamic effects have been studied in 24 male patients suffering from chronic, severe angina pectoris (Class II and III according to the NYHA) by means of right heart catheterization and repeated quantitative bicycle ergometer exercise test before and after 10 mg. Ni given orally. After Ni, the total work performance until exercise-induced angina occurred increased from 14.16 +/- 6.8 to 24 +/- 12.8 Kilojoules (+ 85.6%, p < 0.001), while the exercising pulmonary artery wedge pressure decreased from the initial control level of 28.5 +/- 6.7 to 17.86 +/- 4.3 mmHg (p < 0.001), indicating a probably equivalent drop in the left ventricular end-diastolic pressure and hence a clearly improved left ventricular function. The drug produced only a 3.2%, not significant rise in the exercising heart rate and a moderate fall in the exercising humeral artery systolic (-8.6 mmHg, p < 0.001), diastolic (-7.8 mmHg N.S.) and mean (-10, 1 mmHg N.S.) pressures. Most patients considered the second exercise test after Ni as less tiresome, and no relevant side-effects occurred. The mechanisms of this very evident antianginal action of Ni are discussed and it is concluded that this beneficial effect probably occurs by the way of a reduced left ventricular afterload and probably also of an increased or otherwise more efficient oxygen supply to the heart, whereas a depressing action of the myocardial contractility seems excluded.

Aged↗
PubMed1979

Different sensitivity of hemagglutinating and hemolytic activities of Sendai virus to non-antibody inhibitors.

Research was carried out in order to verify if some components of human serum, which are capable of inhibiting the hemagglutination by Sendai virus, are active even towards the hemolysis by the same virus. It was ascertained that both orosomucoid and low-density lipoproteins obtained by floatation had no action on the hemolysis by Sendai virus while lipoproteins precipitated with dextrane sulphate showed a certain inhibiting effect. This action however is not due to lipoproteins but is probably related to some substances used in the method of precipitation.

Antibodies, Viral↗
PubMed1977

[Septal displacements during intraventricular conduction disorders. Echocardiographical study].

We have analysed the echocardiograms of ten healthy subjects, sixty patients with disorders of intra-ventricular conduction, and ten who were treated by a temporary intracavitary pacemaker. There was found to be a pre-ejection displacement of the septum towards the posterior wall, beginning just after electrical depolarisation of the ventricle followed, in most cases, by 'paradoxical' displacement towards the anterior wall during systole. Such a displacement, producing a 'beaked' image on the echocardiogram, is only found when the ventricular complexes have the characteristics of complete left bundle branch block (LBBB), whether this is spontaneous LBBB or a functional LBBB produced by an intracavitary pacemaker. The results support the hypothesis that the posterior displacement of the septum in cases of LBBB is related to abnormal spread of excitation. Under these conditions, during the pre-ejection period the septal forces predominante over those of the free wall of the left ventricle. In a patient with LBBB who had failed to show this typical septal displacement in several investigations, the 'beak' of the septum could be observed only when the electrical axis deviated to the left, and when the QRS complex exceeded 0.14/s to 0.16/s, this condition being fulfilled because the LBBB was really complete at the time of the last investigation.

Aged↗