[Membranotropic effect of some triterpene glycosides possessing immunostimulating properties].

The peculiarities of the interaction between cell membrane lipids and triterpene glycosides from holothurians Apostichopus japonicus S. and Cucumaria japonica (holotoxin A1 and cucumarioside A2-2, respectively) were studied in comparison with plant saponins from Quillaja saponaria, known as hemolytic, adjuvant, and structure-forming components of immunostimulating complexes. Similar to Quillaja saponins, the sea glycosides, holotoxin A1 and cucumarioside A2-2 were shown to possess a high hemolytic activity (2.6 and 3 microg/ml, respectively) and sterol-depending membranotropic effect mediated by the formation of nonbilayer sterol-lipid-glycoside complexes. At the same time, cucumarioside A2-2 bound exogenic cholesterol only in the presence of membrane lipids, such as phosphatidylcholine or monogalactosyldiacylglycerol, in contrast to Quillaja saponins and holotoxin A1, which bound cholesterol in the molar ratios 1:2 and 1:8, respectively. Moreover, in all cases, tree-component complexes containing cholesterol, lipid, and glycoside exhibited a lower hemolytic activity compared with two-component sterol-glycoside complexes. It was concluded that the hydrophobic medium of cell membranes performs a potentiative role in the effective interaction between triterpene glycosides and "sterol receptors". A method for decreasing the toxicity of membranotropic holothurian glycosides possessing the immunomodulating properties was suggested.

[The prognosis of small-cell cancer and malignant carcinoid of the lung]. / O prognoze melkokletochnogo raka i zlokachestvennogo kartsinoida legkogo.

The morphological examination of 228 small-cell carcinomas and carcinoids of the lung, and evaluation of carcinoid tumor cataplasia versus posttreatment survival identified well-, moderately and poorly differentiated carcinoids. Well- and moderately differentiated tumors have a favorable clinical course and prognosis, though they tend to metastasize. Poorly differentiated carcinoids are characterized by an unfavorable course which is virtually similar to that of small-cell cancer. Prognosis of both malignancies was found to depend on primary tumor size and degree of regional lymph node involvement. Treatment should be determined by histologic type and degree of tumor extension. Well- and moderately differentiated carcinoids and the locoregional form of small-cell cancer make the case for surgery (which should be a component of combination treatment in the latter case). Complex and combination therapy should be used for poorly differentiated carcinoid and extended small-cell cancer.