Effect of Chemically Transformed Macrocyclic Polyene Antibiotics on Tumor Cells.

Comparative analysis of the effects of chemically transformed polyene antibiotics pimaricin, nystatin, lucensomycin, amphotericin B, and levorin on biological objects in vivo and in vitro revealed the greatest biological activity of original amphotericin B and levorin with its derivatives. The study also examined the effects of alkyl derivatives of amphotericin B and levorin modified in certain parts of the lactone ring on the lipid and biological membranes. It is established that methylated levorin possesses larger biological activity than the original antibiotic.

[Ways of reducing mortality in injuries of the heart].

Based on an analysis of literature and 45 personal observations the authors make a conclusion that reduction of lethality following wounds of the heart can be reached by introducing certain changes into traditional approaches to the problem. In order to approximate the moment of medical aid to the victims thoracotomy for the liquidation of heart tamponade, arrest of bleeding should be performed at the place of accident or in the admission department of the hospital, even to the detriment of traditional requirements of asepsis. For the prevention and treatment of early and late complications the patients must be directed to specialized centers (thoracal departments of the hospitals).

[The submolecular structure of the Carnation Mottle virus].

The model of the tertiary structure of the CMtV subunit was suggested and the mode of its packaging into the capsid was determined on the basis of electron microscopy small-angle X-ray scattering and X-ray diffraction data. The i-ray diffraction data on the crystal of the native virion of Carnation Mottle Virus were obtained on the automatic diffractometer supplied with two-dimensional detector.

[Action of the alkyl derivatives of amphotericin B on the conductivity of bilayer lipid membranes].

Amphotericin B alkyl derivatives increased conductivity of bilayer membranes by formation of channels in them. The properties of such channels were studied. A new method for determination of the polyene antibiotic toxicity is described.

[Role of muscles stabilizing the human shoulder joint].

Clinical observations of the surgeon-traumatologist demonstrate the role of the muscles inserting to the greater and smaller tubercles of the humerus for fixating the shoulder joint.

[Recurrent dislocation of the shoulder].

The article describes rich experience in the surgical treatment of the habitual dislocation in the shoulder joint. The method is based on the anatomo-physiological grounds consisting in the repair of the capsule ligament and elimination of the provocating influence of the subcapsular muscle which had lost its elasticity because of injuries in each dislocation. Operations, when correctly fulfilled, result in favourable outcomes in 94--95% of cases.

How do ionic channel properties depend on the structure of polyene antibiotic molecules?

A study has been made of the properties of ionic channels formed in phospholipid-cholesterol bilayers by polyene antibiotics of various molecular structures. Properties of channels created by natural antibiotics with different structures of the lactone ring (amphotericin B-nystatin-mycoheptin) as well as by some derivatives of amphotericin B modified with respect to the amino and carboxyl groups are compared. Neutralization of one or both charges of the amphotericin B molecule (both by chemical modification and by pH shift) increases the probability of the channel to be in a nonconducting state.

[Penetration of polyene antibiotics into human embryonic kidney tissue cell cultures].

Penetration of 14C-amphotericin AM-2 into the cells of the tissue culture of the human embryon kidneys was studied by means of light autoradiography after incubation with the antibiotic. Microscopic examination of the autographs of the cell slices revealed the presence of the radioactive label in the cytoplasm and nucleoplasm of the cells. The revealed intracellular localization of the label was evident of the antibiotic penetration into the cells.

[Nystatin and amphotericin B sorption complexes with polyvinyl-pyrrolidone in nonaqueous solvent systems].

Complexes of polyenic antibiotics with polyvinylpyrrolidone (PVP) can be used for preparing effective pharmaceutical forms soluble in water and consisting of fine dispersions. Studies were carried out; they are of great importance for revealing the mechanism of polyen interaction with neutral polymers, as well as for development of the technological processes for production of the pharmaceutical forms. The sorption isoterms of PVP with the molecular weight of 10 000 and 35 000 on nystatin and amphotericin B were obtained in the process of precipitation in the system of dimethylformamide-ethylacetate.

[Study of the association of nystatin and amphotericin B in nonaqueous solvent systems].

Association of nystatin and amphotericin B in non-aqueous systems was studied with the method of equilibria dialysis. A specially treated celophane membrane arresting colloid associats and macromolecules with a molecular weight of more than 30000 in the systems of dimethylformamide-ethylacetate was used for the dialysis. Relation between the dialysis rate and the difference of the concentrations at every side of the membrane was used for estimation of the antibiotic colloid association level.