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Biomedical subjects

C Bruno

Publications and source records attributed to C Bruno.

At least 127 records · Page 7Linked to original sources
PubMed1984

[Changes in the synaptic activity in sciatic nerve-extensor digitorum longus (preparations induced by ethanol)].

The aim of this research is the study of the modification of synaptic activity caused by ethanol in the rat sciatic nerve-extensor digitorum longus (EDL) muscle preparation. For such a purpose, intracellular recordings have been carried out, keeping the muscle immersed in normal Ringer solution and in Ringer solutions containing ethanol at different concentrations up to 0,8 M. Therefore, the resting potential of muscle cells and the frequency of m.e.p.p.s were measured. Qualitative observations of m.e.p.p.s shape were also carried out. Ethanol increases the frequency of m.e.p.p.s in the rat sciatic nerve - EDL muscle preparation. The logarithm of relative frequency (frequency in Ringer solution with ethanol/frequency in normal Ringer solution) is linear with respect to the concentration of ethanol, with a slope of 1.44. Furthermore, ethanol increases the amplitude and lengthens the time course of m.e.p.p.s. The muscle cells undergo a hyperpolarization of about 2-3% at the lowest concentrations of ethanol tested.

Animals↗
PubMed1984

[Variations in the hyperpolarization potential of ethanol on muscle during reinnervation].

Ethanol causes the hyperpolarization of the excitable membranes. In the Extensor Digitorum Longus (EDL) muscle of the rat the increase of resting membrane potential is 2-5% and is independent of the concentration of alcohol between 0.2 and 0.4 M, while at higher concentrations the membrane potential falls to levels equal or inferior to the normal potential. We have studied the hyperpolarization action of ethanol on the denervated muscle by crushing the sciatic nerve. Also under these conditions in which, as is known, there is a drop in the resting potential, ethanol causes hyperpolarization, however it is in general greater and it is dependent upon the concentration between 0.2 and 0.8 M.

Animals↗
PubMed1984

[The recovery of motor innervation during treatment with ethanol].

We have studied the effects of the fluidizing action of ethanol on motor reinnervation in order to clarify if membrane fluidity changes affect synaptic plasticity and nerve regeneration. Sprague Dawley rats were denervated by crushing the sciatic nerve and subsequently, on the 16th day, the degree of reinnervation of the EDL muscle was observed by electrophysiological technique: in particular an observation was made of the resting potential and the m.e.p.p.s frequency by intracellular recordings in muscle fibers. During the nerve regeneration period, the rats were treated with 3 g of ethanol per kilogram of body weight per day. We have found that ethanol quickens the resting potential recovery but does not affect the m.e.p.p.s frequency.

Action Potentials↗
PubMed1983

[Effects of nicotine on the electrocardiogram of the rat].

In these experiments in the rat was studied the action of nicotine, administered intravenously in doses from 20 to 900 gamma/Kg. It was seen that, after the injection of lower doses, in the first phase there is always a more or less conspicuous diminution of the heart rate and a light and fleeting rise of the time of a-v conduction; there follows, after 25-30', a phase in which there is, as already noted, a rise of the heart rate. After higher doses was observed always an increase of the heart rate. Extrasystoles due to the action of nicotine was not observed. Sometime were observed signs of subendocardial damage or of fleeting right bundle-branch block. After a dose of 300 gamma (900 gamma/Kg) was observed a conspicuous and brief inhibition of sinus node activity and of the a-v conduction.

Animals↗
PubMed1983

[Gelatin-cystine, keratogenesis and structure of the hair].

It is known how noticeable modifications may be induced in the high sulphur content proteins of wool, by enrichment of the diet of sheep with cysteine or sulphur amino acids. It is also well known how the oral ingestion of gelatin significantly increases hair diameter and the degree of hardness of finger and toe nails. To the end of verifying the possible stimulating selective action performed by cystine and gelatin in the keratinization processes of the hairy structures, it was controlled: amino acids content in hair of normal rat after oral ingestion of a controlled quantity of gelatin-cystine added in the diet. The same experiments have been carried out on rats in which the condition of sufference of the hair was induced by means of a biotin-free diet. From the obtained data it seems that gelatin-cystine, added in the diet of normal or suffering rats, helps to modify the cysteine content of the sulphur-rich hair proteins (+ 50% abt.). The diet supplement bring about a considerable increasing of CYS (+ 35%) with a decreasing of GLY (- 15%).

Amino Acids↗
PubMed1981

[The importance of N-acetylneuraminic acid and of its interaction with Ca++ in the stability of the erythrocytic membrane].

The aim of this paper is to draw information about influence of human red cell N-acetyl-neuraminic acid and its interaction with Ca++ on membrane itself stability. Then, changes of red cell behavior in reply to osmotic stress with and without Ca++ after treatment with neuraminidase has been studied. We noted that the treatment with neuraminidase causes spontaneous hemolysis (about 9%), independently of medium osmolarity. As regards membrane resistance to osmotic stretching, N-acetyl-neuraminic acid has a destabilizing effect on most erythrocytes whereas its interaction with Ca++ don't influences significantly membrane resistance to osmotic stretching. Nevertheless, in extreme conditions of osmolarity (i.e. when hemolysis of younger red cells occurs), destabilizing effect of N-acetyl-neuraminic acid is no longer observable and, on the contrary, when it interacts with Ca++, it increases the osmotic resistance of red cells.

Calcium↗
PubMed1981

[Effects of Vipera berus venom on the activity of some coagulation factors].

The activity of some clotting factors of human blood after incubation at 37 degrees C with Vipera berus venom (400 microgram/ml of plasma) has been measured. Factor V, initially, is activated by venom, but rapidly its activity decreases, becoming lower of that of controls and it exhausts oneself almost fully after 2 hours. Changes in the prothrombin and fibrinogen activity by venom action have not been noted.

Adult↗
PubMed1981

[Experimental electrocardiography research. A study in the rat of the cardiovascular effects of verapamil].

Electrocardiographic changes induced by Verapamil, drug inducing inhibition of transmembrane movement of calcium into cardiac cells and mobilization of intracellular Ca++, have been studied in 10 anesthetized rats. Authors observed that Verapamil has: 1) negative chronotropic action on SA node; sometimes appears a superior nodal rhythm; 2) inconstantly, negative dromotropic action with prolonged atrioventricular conduction and "period of Luciani-Wenckebach'; 3) effective antiarrhythmic action; 4) no protective action towards peripheric vascular epinephrine effects; 5) remarkable negative inotropic action, whose Authors consider indirect signs the electrocardiographic changes, which indicate severe coronary failure, and the death of 6 rats by acute pulmonary edema.

Animals↗
PubMed1981

[Experimental electrocardiographic research. Study in the rat of the cardiovascular effects of labetalol].

Electrocardiographic changes induced by Labetalol, a drug blocking alpha- and beta-adrenergic receptors, have been studied in 10 anesthetized rats. Authors observed that Labetalol has: 1) slightly negative chronotropic action; 2)slightly negative dromotropic action on both atrio-ventricular and intraventricular conduction; 3) effective antiarrhythmic and alpha-blocking action and, inconstantly, 4) the so-called "intrinsic sympathicomimetic action" (I.S.A.), typical of several beta-blocking drugs.

Animals↗
PubMed1981

[Coagulant and anticoagulant action of Vipera berus venom on human blood].

The effect of Vipera berus venom on coagulation of human blood has been studied. PTT and coagulation time according to Quick of normal human plasma kept with Vipera berus venom (400 microgram/ml) for variable times have been misused. The venom has an immediate coagulant and, subsequently, anticoagulant effect.

Blood Coagulation↗
PubMed1979

[Variations in human blood osmotic globular resistance by the action of Vipera berus venom in different experimental conditions. I. Hemolytic effect].

The effect of Berus Viper's venom on human blood globular resistance with changing incubation conditions has been studied. Particularly venom's concentration (from 200 to 400 microgram/ml of blood), temperature (from 20 degrees C to 37 degrees C) and time (from 1/2h to 2h) have been changed. Time and temperature are important factors in haemolytic process development, instead venom's concentration behave like a factor not significantly haemolysis modifying.

Dose-Response Relationship, Drug↗