PubMed Health⌕ Search

Biomedical subjects

A A Avakian

Publications and source records attributed to A A Avakian.

At least 19 recordsLinked to original sources

[Ultrastructure of the initial stages of interaction between halprowiae (Chlamydiae) and host cells].

The initial stages of the interaction of halprowiae (strain CP-1), isolated in Reiter's syndrome, with a monolayer culture of cells L-929 were studied. The electron-microscopic examination of the cells every 2 hours during the first 24 hours after the inoculation allowed to follow the processes of adsorption, endocytosis of elementary bodies and their transformation into reticulate bodies by the "decondensation" of nucleoid, which indicated the beginning of the vegetative (reproductive) stage of the developmental cycle. During all the periods of observation halprowiae were enclosed into the membranes of phagocytic vacuoles formed by host cells. Besides, in other vacuoles (probably, phagolysosomes) halprowiae at various stages of destruction could be observed. 8--10 hours after inoculation the phagosomes containing reticulate bodies began to merge, thus forming an inoculation the phagosomes containing reticulate bodies began to merge, thus forming an intracytoplasmic inclusion. In this inclusion a new generation of the agent was formed by binary-like fission. At the beginning of the vegetative stage halprowiae seem to be highly sensitive to the action of exo- and endogenic factors which may cause their L-transformation. Depending on the reaction of the host cell at the initial stages of interaction with halprowiae, 3 ways of such interaction are seemingly possible: developmental cycle, destruction in phagolysosomes. L-transformation.

Adsorption↗

[Unusual small forms in the growth cycle of halprowia (chlamydia) and their possible relation to manifestations of L-transformation].

The authors carried out a comparative electron-microscopic study of the ultrastructure and the developmental cycle of 15 Halprowiae (chlamydiae) strains isolated in different pathology from man and animals. Halprowiae were cultivated in the yolk sac epithelium of the developing chick embryos and in the L-cell monolayer cultures without any special action of the antibiotics and medicines. Formation of minute round structures ("minute forms"), 50--120 nm in diameter, separating from the protoplast into the periplasmic space and surrounded with cytoplasmic membrane by the vegetative forms of a number of strains (MP, AP-23, 25-SM, LB-1, MyB), is described. Along with minute forms, Halprowiae formed polymorphous giant bodies with long protrusions into the inclusion cavity; there was also a separation of vesicles of the cell wall membrane. This apparently indicated a structural derangement of the cell wall in these vegetative forms of Halprowiae. On the basis of similarity of the mentioned structures detected in Halprowiae reproduction to the known morphological characteristics of the L-form bacteria a possibility of L-transformation in Halprowiae during the normal developmental cycle as a peculiar compensatory adaptation to the action of host cell is supposed.

Chlamydia↗