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Biomedical subjects

G Marchetti

Publications and source records attributed to G Marchetti.

At least 37 records · Page 2Linked to original sources
PubMed1979

[The behavior of blood viscosity in polyglobulism].

In polyglobulic subjects we have found a variable reduction of plasmatic viscosity, with an increase of total viscosity. If the increase of Ht is the first cause of the increase of total viscosity, it is less simple to find the cause of plasmatic viscosity decrease; to this end we have analysed direct and indirect factors (coagulation factors, proteinous and lipidic components). We haven't found any significant qualitative alterations. It is proposed the importance of the interventions of basic proteins of polication type. To this end it has been studied the connection between plasmatic viscosity and ESR, being both influenced by the same factors, but in a contrary way and with variable results. Then the role of plasmatic viscosity in these subjects, in substitution of ESR, is significant.

Adult↗
PubMed1979

[Variations of hematic and plasmatic viscosity as a function of flow velocity, analyzed by means of an experimental model].

The authors have determined the hematic and plasmatic viscosity in 60 sound subjects, 30 men and 30 women respectively, at different values of cut drop, corresponding to the values that can be found at different levels of circulatory system. These subjects had value of Ht, total protidemy, cholesterolemy and trigliceryds, included in normal limits. For these determinations, made at constant temperature, they have used Well-Brookfield with a divergent angle of 0,8 degrees. In this way they could determinate the normality limits of hematic and plasmatic viscosity, in men and women, in connection with the physiologic modifications of flux speed. It has been confirmed the tixotropo behaviour of blood, whose viscosity increases exponentially for lessenings of cut drop and we have put this fact in touch with genesis of thrombosis. They haven't shown any expressive difference in the behaviour of the curves of two undergroups; the curve of middle values is higher for men, and it seems that this difference is owing to Ht. esclusively. In the end they have considered the curves of subjects that had values of viscosity different from normality; in this way they have found three different curves, in pathologic conditions.

Blood Flow Velocity↗
PubMed1978

Hemodynamic and metabolic changes induced by temporary clamping of the thoracic aorta.

Numerous authors reported a significant deterioration of heart function induced by aortic cross-clamping. Nevertheless, the aorta has been clamped during various surgical procedures without any complication. We studied the hemodynamic and metabolic variations induced by 20 min thoracic aorta cross-clamping in 6 open-chest dogs. During clamping the most striking modifications were an increase in coronary blood flow of over 65%, an increase in cardiac work of over 77% and an increase in total peripheral resistances of over 68% compared to base values. No significant variations were found in the heart rate and cardiac index. Metabolic parameters, such as O2 consumption and lactate consumption increased significantly during the clamping period. The increase in lactate consumption and the progressive and continuous improvement in oxygenation indexes (lactate/pyruvate, redox potential, excess of lactate) proved the absence of any myocardial anoxia during this period. Within 15--30 min after declamping all hemodynamic and metabolic parameters reverted to values close to basal values. These data strongly suggest that the mammalian heart can tolerate this procedure satisfactorily for a limited period of time. In clinical settings, one should consider the base conditions of the cardiovascular system before transposing these conclusions.

Animals↗
PubMed1978

Effects of creatinol-O-phosphate (COP) on haemodynamics and cardiac metabolism in conscious and anaesthetized dogs.

The effects of creatinol-O-phosphate (COP, Aplodan) have been studied on haemodynamics and cardiac metabolism of virtually normal heart (conscious dogs with electromagnetic probes chronically implanted) and progressively failing heart (open chest anaesthetized dogs). The results obtained show that COP in both series of experiments increased cardiac work and improved some myocardial metabolic parameters (delta redox potential across the heart, lactate/pyruvate ratio, excess lactate) probably by enhancing the myocardial O2 supply-consumption ratio, and consequently increasing the amount of O2 available for energetic reactions in the cardiac muscle and possibly in other tissues as well.

Animals↗
PubMed1978

Pharmacokinetics of deslanatoside C-3H administered parenterally to the guinea-pig, rabbit and dog.

The pharmacokinetics of Deslanatoside C-3H, a short-acting polar cardiac glycoside, were investigated in the guinea-pig, rabbit and dog, after parenteral administration. Deslanatoside C was on average 20% plasma protein-bound and had a red blood celle/plasma partition ratio of 1/9. Tissue uptake of Deslanatoside C observed in the guinea-pig seems on average to be higher than in rabbits. Among the various organs and fluids tested, the highest levels were encountered in the urine, bile and kidneys of both the guinea-pig and rabbit. The main excretory route of this glycoside was via the urine, although significant amounts were excreted via the bile in all the three species tested. Cumulative urinary excretion 24 hr after i.v. injection was 50% (75% of which in unchanged form) in the guinea-pig, 46.5% (86% of which in unchanged form) in the rabbit, and 42.9%(84% of which in unchanged form) in the dog. Among the cardiac glycosides, Deslantoside C seems to possess the highest urinary excretion rate, which has in fact also recently been confirmed in human subjects.

Animals↗
PubMed1977

Absorption, fate and excretion of glaziovine-14C in the dog.

The pharmacokinetic parameters of glaziovine, a proaporphine alkaloid with neuropharmacological properties, were investigated in dogs. At alkaline pH, glaziovine-14C showed a very high partition coefficient value from a buffered water solution and both benzene and chloroform. When administered i.v. to both conscious and anaesthetized dogs, levels of glaziovine-14C were higher in the heart, liver, kidneys and brain, and lower in skeletal muscle, skin and plasma. The high amount of radioactivity found in the small intestine as well as that found in bile obtained from a biliary fistula demonstrates that glaziovine is excreted both via the bile and via urine in not dissimilar amounts at least in dogs. When administered orally, peak plasma levels were encountered in 1 hr. Cumulative urinary excretion of glaziovine over a 24 hr period was 49% after the i.v. route and 39% after the oral route. By comparing the percentage of urinary excretion or the area under the plasma level time curve (AUC) obtained in the first 24 hr after i.v. and oral administration, percentages of bioavailability were obtained ranging from 80 to 98%. Glaziovine thus seems to possess a very high enteral absorption.

Absorption↗
PubMed1976

Plasma turnover and excretion of K-strophanthoside-3H in human volunteers after parenteral administration.

Pharmacokinetic parameters of K-strophanthoside-3H, a short-acting cardiac glycoside, were investigated in healthy subjects, patients suffering from heart disease, renal failure and in cholecystectomized patients with a biliary T-tube inserted surgically, after parenteral administration of 250 mug of the glycoside. The healthy subjects, patients suffering from heart disease and those with the biliary T-tube showed a dominant half-time for plasma turnover of the glycoside of 15-16 h after the i.v. route and 18-22 h after the i.m. route and cumulative urinary excretion of the drug over a 24 h period of 37-42% (i.v. route) and 32-33% (i.m. route). The volumes of distribution were lower in patients with heart disease and patients with biliary fistula than in the healthy subjects. In patients suffering from renal failure the dominant half-time of plasma turnover was higher (33 h), while cumulative urinary excretion of the glycoside (12%) and the volumes of distribution were lower than in the healthy subjects. A peak of plasma levels 30 min after i.m. administration of K-strophanthoside-3H leads to the conclusion that this glycoside is rapidly absorbed when injected intramuscularly.

Bile↗