Biomedical subjects
Publications and source records attributed to M S Gavelli.
The mathematical definition of arterial pressure is an essential requisite if one is to develop an informatic model. By applying analytical calculus we can set up a cybernetic model. We have proposed a cybernetic program for the study of renin-dependent arterial pressure.
The authors report the results of a comparative study of the effects of lovastatin and gemfibrozil on plasma cholesterol. Both drugs inhibit the enzyme systems responsible for cholesterol synthesis at the initial stages. The trial was conducted in 40 patients with nonfamilial hypercholesterolemia of whom 20 were treated with lovastatin and 20 with gemfibrozil. Throughout the trial, subjects took a dietary regime of about 1500 cal. Thirty days' before the start of the trial, patients received a placebo daily. Before and after the placebo period and at the end of 30 days treatment with either drug, cholesterol, esterified cholesterol, VLDL, LDL, and HDL cholesterol, apolipoprotein B, phospholipid, triglyceride and free fatty acid blood levels were tested, as well as the level of fatty acid saturation (iodine number), and the activities of lipase and plasma heparin. The results obtained showed both drugs to induce significant reductions of total, VLDL- and LDL-cholesterol and apolipoprotein B, and a relative increase in HDL-cholesterol. Triglyceride blood level was more markedly reduced in patients treated with gemfibrozil compared to those treated with lovastatin, a difference accounted for by the different levels at which the two drugs interfere with the enzymes of the initial stages of cholesterol synthesis. Plasma free fatty acids rose more markedly under gemfibrozil while plasma lipase and heparin activity did not show any appreciable changes under either drugs. The authors conclude by pointing out that the use of these drugs should be decided according to the type of metabolic disorder to be corrected.
The authors report the results obtained in a comparative study of effects of clofibrate and simvastatin. The investigation was carried out on 44 patients with type IIB hypercholesterolemia subdivided into two groups. Throughout the study, patients observed a diet of about 1500 Kcal daily. Thirty days before starting drug treatment, all patients were given a placebo daily, either of the two drugs being administered during the subsequent 30 days. Plasma cholesterol level was examined before starting placebo and before drug treatment and every five days throughout drug treatment. The results obtained showed that both drugs reduced cholesterol plasma level significantly but the reduction obtained with simvastatin was greater than that obtained with clofibrate. The specificity of the use of these drugs in the management of hypercholesterolemia is stressed.
The common language of many researchers of different scientific fields, is the systematic method. In this paper the concept of abstract systems is developed. The applications of multidimensional abstract systems, of oriented probabilistic type, in biological systems is especially stressed. For mathematical interpretation of the problem, Moore's model is proposed.
A comparative trial was carried out on the effect on lipid metabolism of two drugs which inhibit the enzyme systems involved in cholesterol synthesis: tiadenol and simvastatin. The trial was performed in 40 patients with non familial and non secondary hypercholesterolemia. Subjects were divided into two groups of 20 patients each, one to be treated with tiadenol, the other with simvastatin. During the study period all patients followed a dietary regime of about 1500 cal daily. Thirty days before the trial, patients were given a placebo daily, and this was followed by thirty days with the drugs studied. Prior to the placebo period and at the end of the experimental period, blood was drawn for the assessment of total cholesterol, esterified cholesterol, VLDL-, LDL- and HDL-cholesterol, apolipoprotein B, phospholipids, and triglycerides. Both drugs were found to induce significant reductions of total cholesterol, VLDL, and LDL, a relative increase of HDL, and reduction of apolipoprotein B. Triglyceride blood level was markedly reduced in tiadenol-treated subjects, and to a lesser extent also in simvastatin-treated ones. This difference is attributed to the different levels at which the drugs interfere with the early steps of cholesterol synthesis. The authors conclude by pointing out that the two drugs should be used selectively according to the type of metabolic disorder prevalent in the individual patient.
The authors report the results of a study of 1963 patients treated with daily doses of 2 g DEAE-dextran. This was an open trial intended to evaluate the evolution of several biohumoral parameters under treatment for dyslipidemias. Statistically significant results were obtained for cholesterol blood level, triglycerides and body weight, as well as a favorable trend for HDL-cholesterol. Side effects or untoward reactions to DEAE-dextran were not observed.
Having briefly recalled the close functional interaction of diseases which often involve both syplay between skin and kidney, the authors suggest a new model for the nosographic classificastems and are at present observed with increasing frequency.
Attention is drawn to the relationship between informatic and biological models in the study of problems of human physiology and physiopathology. The biomathematical principles are analyzed, to which reference must be made for the elaboration of the expert systems, necessary in evaluating biological feed-back in particular.
Plasma testosterone and cortisol concentrations were measured in 32 familial heterozygous hypercholesterolaemic subjects, aged 40-45 years. The subjects were divided into two groups of 16, each containing eight men and eight women. The women had normal menstrual cycles. After a period on placebo, one group of patients was given 40 mg/day lovastatin and the other was given 1500 mg/day clofibrate. Both drugs significantly reduced the plasma cholesterol concentration, however, unlike clofibrate, lovastatin did not decrease plasma levels of testosterone and cortisol. The response to stimulation by adrenocorticotrophic hormone of plasma cortisol and urinary 17-hydroxy levels was significantly reduced by treatment with clofibrate, but unchanged by lovastatin. The different effects produced by the two drugs probably reflect different mechanisms and sites of action.
Attention is drawn to the relationship between informatics and biological models in the study of problems of human physiology and physiopathology. The biomathematical principles, to which reference must be made for the elaboration of the expert systems, necessary in evaluating biological feed-back in particular, are analyzed.
Attention is drawn to the relationship between information and biological models in the study of problems of human physiology and physiopathology. The biomathematical principles, to which reference must be made for the elaboration of the expert systems, necessary in evaluating biological feedback in particular are analyzed.