[Mathematical algorithm for constructing optimal standard descriptors for differential diagnostics of chest organ diseases].

This paper presents a mathematical algorithm based on constructing optimal standard descriptors to reduce the major causes of medical errors in groups of patients with chest diseases. It was shown that the mathematical algorithm based on the results of correlation analysis mand calculation of the prognostic sum of descriptors for the study (medical errors) and control (no medical errors) groups allows a new patient to be referred to either group. A computer program based on the mathematical algorithm enables it to be applied to determining group affiliation of the patients.

[Strategic problems in counteracting the spread of HIV infection in the Altai Territory].

The Altai Territory belongs at present to regions with the insignificant level of the spread of HIV infection. By December 1, 1999, the Altai Territory had 31 registered cases of HIV infection, which constituted 1.33 per 10,000 of the population (the corresponding figure for the whole of Russia being 14.

[The anti-ischemic properties of crown ether derivatives].

Experiments on open-chest anaesthetized cats were made to test derivatives of crown ethers, such as benzylase-15-crown-5 and dibenzylase-15-crown-5 for their effects on myocardial ischemia and the functional status of a myocardial ischemic focus in temporary coronary occlusion during coronary spasm induced by dihydroergotamine and during coronary microthrombosis caused by ADP. When intravenously administered in doses of 0.5-15 mg/kg, the tested agents were found to enhance myocardial tolerance to ischemia, depressed ST segment in ischemia induced by coronary occlusion and administration of ATP, and prevented ST-segment depression during coronary spasm.

[The relationship between the magnitude of the negative inotropic action and chemical structure of crown-ether derivatives].

The relationship between the inotropic effect and chemical structure of 15-crown-5 and 18-crown-6 derivatives was studied in experiments in open-chest anaesthesized cats, by using computer-aided analysis. The findings showed that the 15-crown-5 derivatives produced more pronounced cardiotropic effect and they were less toxic than 18-crown-6 derivatives. Computer-aided analysis revealed pharmacophoric groups which are responsible for cardiotropic (negative inotropic) activity in the series of crown ether derivatives.

[Mechanism of the vascular action of verapamil and a crown ether derivative].

The effects of verapamil and benzyl-aza-15-crown-5 on pressor reactions of blood pressure and perfusion pressure in the femoral artery after administration of noradrenaline, tyramine, angiotensin amide and stimulation of the femoral nerve were studied in acute experiments on anesthetized cats (pentobarbital sodium, 50 mg/kg). Verapamil (0.5 mg/kg) and benzyl-aza-15-crown-5 (9 mg/kg) suppressed pressor reactions to the nerve stimulation and produced no changes at administration of noradrenaline, tyramine and angiotensin amide.