Does help in decision-making in biology help in decision-making in human sciences and conversely?

A link between biological and human sciences may be established, under the condition that we should admit the existence of reciprocal influences between them. The model for the regulation of agonistic antagonistic couples (MRAAC) is built from the study of biological systems and gives rise to specific types of control. This model can be helpful in decision processes in some human sciences such as management, economical and political strategies.

As well as physiological states, pathological states and therapeutical problems may be a gushing spring for biological theory--and conversely.

New class of therapies, including bipolar therapies (BPT) and "paradoxical" unipolar therapies (PUT) were firstly proposed in relation to a clinical insight and to some results of biological investigations, then they gave rise to mathematical modeling which brought a justification of these therapies, at least from a theoretical point of view. After recalling the mathematical model for the regulation of agonistic antagonistic couples, and reporting the fundamental types of control simulation by means of it, we point out the validity of therapeutical applications inferred from this model. These therapy modalities, including BPT and PUT, now concern the following diseases: astrocytomas, epilepsia and trials on multiple sclerosis.

Pathological homeostasis: its meaning, its inferences.

The notion of 'pathological homeostasis' (PH) allows a better understanding of the escape phenomena to the effects of a therapy, as suggested by experimental researches. This concept refers to mechanisms we already know as desensitization, mutation, etc. Moreover, it focuses on the following possibility: in a couple of antagonistic agents, the already prevalent one will increase even more so that it could cancel the therapeutic effect of the administered opposite agent.

Role played by vasopressin (and of an adrenalpostpituitary imbalance) in the development of cancerous diseases.

Several authors have demonstrated that vasopressin (VP) plays a role in the metabolism of various cell lines, cancerous or not, and in particular acts upon the growth and the multiplication of cell cultures. Less known are the data concerning the existence of an adrenal-postpituitary imbalance in favour of VP in cancerous patients. Seeing that adreno-cortical hormones (ACH) are able to exert an inhibiting action on cell multiplication in vitor, a similar effect being very moderate or even absent in vivo, one can see the advantage of taking such effects into account.

Evaluation of the addition to corticoids of a growth factor (vasopressin) in the palliative therapy of malignant brain tumours.

Changes in the clinical condition, CT scans and MRIs of patients with recurrent or inoperable astrocytomas and brain metastasis have been observed following treatment with a combination of vasopressin and corticoids. These changes have not been reported with corticoids alone--at least not over the short time reported for this therapy. Ten cases of grade II astrocytomas, seven cases of grade III or IV astrocytomas and six cases of metastasis of bronchial or breast origin were studied.

[Adrenal-posterior pituitary imbalance in digestive cancer patients].

In a group of 10 patients with a cancer of the digestive tract, some investigations, performed before the surgical intervention, showed the evidence of an adrenal-postpituitary imbalance in favour of the second term. During a water loading, the plasmatic cortisol rates stayed more higher by cancerous subjects than by controls (but not the plasmatic aldosterone rates); nevertheless, the vasopressin secretion rates could be considered as more higher yet in cancerous subjects because the free water clearances were significantly lowered by these patients. Such results have to be put in relation with the opposite effects of vasopressin and corticoids on the cell mitosis, as well as with some therapeutical attempts that end to check this type of endocrine imbalance.

[New data on the adrenal-post-pituitary system of cancer patients].

A water loading test was performed in 10 patients with a cancer of the digestive tract without hyponatremia and in 10 controls. A lowering of the CfH2O was observed in the patients during the test, as well as an increase in the cortisol plasmatic rates, while aldosterone rates remained normal. To valid the hypothesis of a hypervasopressinic state in these patients, 15 cancerous patients and 12 controls had a plasmatic ADH dosage, which pointed indicated higher hormonal level in the first group.

Mathematical model for hormonal therapy (vasopressin, corticoids) in cerebral collapse and malignant tumors of the brain (36 cases).

A mathematical model of the adrenal postpituitary system has been used in cases of brain disease in which endocrine disturbances play an aggravating role. A computer simulation has suggested a type of therapy adding vasopressin to corticoids; this association seems to elicit better results than corticoids alone. Posttraumatic disorders of the cerebral hydration, on one hand, and inoperable or recurrent tumors, on the other hand, take advantage of such a systemic, formalized approach.

[Justification of a model of regulation of agonist-antagonist hormone pairs].

An attempt is made to justify the model of the regulation of agonistic-antagonistic hormonal couples (in the field of the adrenal-postpituitary interrelationships). A method of synthesis for these equations is proposed. Cancerous pathology of this regulation could be due to a disturbance in the secretion or in the catabolism of vasopressin.

Computer analog simulation of a model for the regulation of ago-antagonistic couples.

A system of quadratic differential equations is proposed within the framework of 'non-linear mechanics', but also outside this framework in respect of certain features, and it is used with a view to formalising a feedback control system. The model helps to simulate states of balance or imbalance within an ago-antagonistic couple and to suggest methods for correcting the imbalances, which do not require modification of the parameter space. Its possibilities of synchronic or diachronic functioning are emphasised.

[Analytical and analogical study of a model of the adrenal-postpituitary function (author's transl)].

After an analyitical study of mathematical models connected with osmotic or volemic regulations, and the mention of its contribution to the therapeutic act, the authors approach the stimulation, by the mean of an analogical computer, of the complete and non-linear model which associates both types of regulation. So it is possible to attempt to determine the level of adrenal and vasopressin actions according to: 1 degree the sum of the agonistic effects and the difference of their antagonistic effects; 2 degrees the perturbations brought to the system; 3 degrees the parametric values of the model. Theoretical and empirical curves seem to be in favour of such a formulation.