[New horizons in medicine. The application of "fuzzy logic" in clinical and experimental medicine]

In medicine, the study of physiological and physiopathological problems is generally programmed by elaborating models which respond to the principals of formal logic. This gives the advantage of favouring the transformation of the formal model into a mathematical model of reference which responds to the principles of the set theories. All this is in the utopian wish to obtain as a result of each research, a net answer whether positive or negative, according to the Aristotelian principal of tertium non datur. Taking this into consideration, the A. briefly traces the principles of modal logic and, in particular, those of fuzzy logic, proposing that the latter substitute the actual definition of "logic with more truth values", with that perhaps more pertinent of "logic of conditioned possibilities". After a brief synthesis on the state of the art on the application of fuzzy logic, the A. reports an example of graphic expression of fuzzy logic by demonstrating how the basic glycemic data (expressed by the vectors magnitude) revealed in a sample of healthy individuals, constituted on the whole an unbroken continuous stream of set partials. The A. calls attention to fuzzy logic as a useful instrument to elaborate in a new way the analysis of scenario qualified to acquire the necessary information to single out the critical points which characterize the potential development of any biological phenomenon.

[New horizons in medicine. Aging and the laws of modern physics]

Even today the problem of aging is not well known. The latest discoveries on the arrow of time, the theory of complexity, the identification of dissipative stationary structures in "non equilibrium", the observation that deterministic systems with a complex structure may produce chaos (which today we have begun to identify, with evident contradictions, laws and principles: the laws of disorder), are the new laws by which it will be possible to understand the evolution along the time of automatic control feed-back of homeostasis and so the progression of senescence. The attention is pointed particularly to three magnitudes of modern physics: dynamic stability, dissipative structures and entropy. In aging the structures of automatic control systems are submitted to a greater functional effort with the results of a reduction of dynamic stability, an increase in dissipative phenomena and entropy. Moreover the functional exhaustion of homeostatic systems (the linearization of the system) is not compatible with life unless a substitute system takes on its function. In this condition the possibility of survival of the living subjects is conditioned to the capacity of the vicarial system of having a higher state of "non equilibrium" at disposal and therefore of a higher dissipative capacity. From the valuation of dynamic stability, dissipative structures and entropy, it appears possible in a near future to clarify many aspects of the nature and dynamics of aging.

[New horizons in medicine. Complexity and predictability in internal medicine]

Being a highly sophisticated structure, the human body should be considered on a physical level as a whole of inter-correlated non-linear dynamic systems, which are by definition, complex systems because they are always conditioned in their operativity by numerous variables. We must draw attention to the opportunity that within the field of medical science the concept of complexity referring to diagnostic, therapeutic and prognostical problems, is distinct between structural and functional. The functional complexity of a system, a phenomena, an event, MY be recognized in its dynamics, only if analysed using modern methods recently brought to light, on the relationship which exist between classic determinism and deterministic chaos. Furthermore, also on practical level, the recent discoveries on the general principles, which are at the base of the functional complexity of non-linear dynamic systems, demonstrate exactly how fragile is the probabilistic predictability which guides a doctor in clinical reasoning in all its various stages; in the gathering of anamnestic and objective data; in the programming the researches aimed at confirming the validness of the diagnosis; in the therapy aimed at reaching the best possible results; in the prognosis which summarize the destiny of the binomial patient illness. The scientific enunciate of universal nature, which demonstrate how, from a tiny uncertainty in the initial functional data of a system, of a phenomena, of an event can unleash a condition of absolute unpredictability, find daily confirmation in both clinical and experimental medicine.(ABSTRACT TRUNCATED AT 250 WORDS)

[New horizons in medicine. The attractors]

The discovery of the fact that chaotic systems can suddenly coagulate into deterministic systems, and that deterministic systems can precipitate into chaotic systems has, on the one hand, clearly revealed the limits of the Cartesian geometrization of random phenomena, and on the other, has made in possible to identify the attractor as the reference entity when studying the functional dynamics of biological systems. The attractors is identified as the point of equilibrium upon which the behaviour of a dynamic system stabilizes and towards which it is constantly attracted. In some systems the attractor is identified as an "ideal" optimum reference point termed "the point". In other systems, however, the attractor is identified as a closed curve: "the ultimate cycle". Lastly, in other systems the attractor is identified as a surface in which the space of the states delimits a flat doughnut-shaped image constituting a "torus". The recent discovery of the laws governing deterministic chaos has made it possible to identify a new type of attractor termed the "strange attractor". This attractor has a fractal dimension (i.e. one midway between linear and plane), is of finite dimension and depends on the initial condition of the system. In many biological functions it is now possible to demonstrate the presence of attractors that operate starting from different initial conditions or that vary with time or that display both these conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

[New horizons in medicine. Fractals]

In these last few years, a vertiginous growth in the application of informatics in the field of science has generated a new branch of geometry: the geometry of irregularity whose paradigmatical expression is fractals. We can identify in the fractal an object of complex structure which, when gradually enlarged, shows up details which repeat themselves as the scale of enlargement is progressively run through. It is possible, therefore, by using fractals to study and quantify in a much more concise way and much less approximatively those structures which were until recently described as granulous, tentacular, ramified, etc. Fractals bridge the gap between mathematics and visual art and allow us to explore the rapport between determinism and apparent chaos in the study of non-linear biological systems. Fractal dimension is an intermediary one between linear and surface dimensions. The applications of fractals images in the study of certain problematics which concern the cardiovascular system are referred to synthetically; particularly those concerning the sectorial differences of myocardial blood flow and the branches of small coronary vessels, both in physiological and pathological conditions. Fractal images permit us to analyse the regional flow of the pulmonary parenchyma, and to quantify pulmonary damage from thromboembolism. Other applications of fractal studies regard the digestive system, the nervous system and mammary pathology. In specialistic fields, fractals have been studied in both ophthalmology and odontology, and also in biochemistry to study protein surfaces and fluids turbulence.

[New horizons in medicine. Chaos and its laws]

We have synthesized the fundamentals that modern technology offers in all areas of research, especially in the field of biomedicine. The theory of systems, cybernetics, synergetics, boolean algebra, communication science (according to modern laws of signal transmission and translation), the solution of non-linear equations by computer science, applied principles of reduction in biological survey, fractal analysis as a representation of dynamic, chaotic, non-linear systems, defined attractors as conditioning elements of biologic function, are just a few of the many instruments that modern science offers as a revolutionary approach to research programming. Borrowing the laws of mathematics, we have defined the fundamental characteristics of linear and non-linear homeostatic systems along with the concept of predictable behavior of a system as a function of its complex structure. Lastly, we have documented, based on personal research and recent findings in biomathematics, and despite current and strong opposition, how the functional death of any dynamic system is identified by the system's absolute state of equilibrium. The operative errors at times caused by different stimuli acting on specific organs and apparatus, are interpreted not as an index of altered function but as an expression of a chaotic response of the deterministic type and therefore an indication of the system's adaptability to the specific functional requirements in that precise moment.

The application of the theory of systems in internal medicine. State of the art and perspectives

The application and contribution of Cartesian methodology to the development of medicine in physiology, pathophysiology and therapy have been overwhelming. The accumulation of knowledge over the last 3 centuries in scientific research is largely attributed to Cartesian methodology. This method, which in the past was used for the acquisition of nosological data is no longer sufficient for the interpretation of complex phenomena which modern science nowadays requires. The solution to these complex problems is only possible by means of the application of the theory of systems especially for the functional evaluation of biological feedback.

[Therapy of hypercholesterolemia and hypertriglyceridemia. Comparison of the lipid-lowering effect of simvastatin and tiadenol]

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.

Plasma cortisol and testosterone in hypercholesterolaemia treated with clofibrate and lovastatin

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.

[Proposal for the nosographic classification of 2 integrated systems. Interrelations of the cutaneous and renal systems]

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.

[Current concepts in a systemic-informatics study of feedback and blood volume homeostasis. Proposal of a mathematical reference model]

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.

[Methods for studying feedback. Proposal for a mathematical reference model]

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.

Plasmatic heparinic activity following lipid load

Changes of hemocoagulability and of plasmatic fibrinolysis have induced us to study PHA following the administration of the lipid load. We have studied the effects induced by the administration of a lipid load, constituted by 1/2 g of olive oil and by 1/2 g of butter dissolved in 200 ml of vaccine milk. PHA has been estimated in all our subjects under basal conditions and after 4 1/2 hours from the lipid load. The statistical analysis of the results we have obtained shows a significant PHA reduction following the lipid load. Concluding, our results indicates that the lipid load very frequently causes a reduction of PHA which is due to a consumption of heparin. This consumption is more probably due to the activation of lipoprotein-lipase by heparin.

Comment: On the Decomposition of Aqueous Sodium Dithionite

The mechanism proposed by M. Wayman and W. J. Lem for the decomposition of dithionite ion in aqueous solution is reconsidered in the light of previous work done by the authors.