[In vitro research on the interaction of natural zeolites with diploid cells from the human embryonic lung]. / Izsledvane in vitro vzaimodeistvieto na prirodni zeoliti s diploidni kletki ot choveshki embrionalen bial drob.

A study of the biological effect of the natural zeolites, clinoptilolite, mordenite and erionite on monostratum cellular culture of human embryonic lung is performed. The number of pyknotic cells, morphological changes in the cells, and monostratum, mitotic activity and changes in the cellular culture are reported during a continuous experiment. As positive control is used standard quartz dust DQ-12 and for negative dust of TiO2. It is already established that the dust particles of natural zeolites with dimensions under 5 micron display biological aggressiveness. With most strongly expressed effect is the clinoptilolite dust, which related to identical active surface, is comparable to that of quartz DQ-12. The mordenite is with moderate cytotoxic effect, proportional to the time and concentration, while erionite is with slight and very delayed effect. There are differences concerning the effect on the miotic activity of the cells. The biologic aggressiveness of the zeolites is discussed in relation to their strong active surface, their ionometabolic properties and their capacity to generate hydrogen at moistering.

[Immunofluorescence and electron microscopy study of bovine reovirus multiplication in cell culture]. / Imunofluorestsentno i elektronnomikroskopsko izsledvane vurkhu razmnozhavaneto na govezhdite reovirusi v kletuchna kultura.

The appearance and development of reovirus antigens was followed up in Vero cells. The earliest immunofluorescence finding was established at the 6th hr, consisting in the appearance of small shining granules in and around the nuclear cytoplasm. At the 24th hr in 15 per cent of the cells there was a positive immunofluorescence finding in the form of one or several objects grouped closely to the nucleus. At the 36th hr fluorescence was seen in about 50 per cent of the cells to surround the nucleus and fill the whole cytoplasm or appearing as a limited and demarkated one. By form the fluorescent objects resembled viral inclusions. The immunofluorescence finding reached its peak at the 48th hr. In cells infected with Reo 2 the appearance and cumulation of the virus antigen ran its course in the same sequence as that seen with Reo 1, however, it was manifested with higher intensity. The electron-microscopic study of Reo 1-infected cells revealed greater diversity in the stages of infection as early as the 24th hr--from the appearance of sporadic virions up to the emergence of large virus crystals the virions in which assumed square or hexagonal arrangement. There was also linear arrangement of the virions by the length of the tubular cell structures. Cells infected with Reo 1 and Reo 2 presented likewise zones with large masses of virus matrix prior to the appearance in them of new virions. There was also particular cumulation of the cell ribosomes along with the matrix formation. It is believed that the appearance of these formations is associated with the virus morphogenesis.

[Pathomorphological studies of experimental echinococcosis in sheep]. / Patomorfologichni izsledvaniia na eksperimentalna ekhinokokoza pri ovtse.

Histopathologic investigations in dynamic (from the 3rd up to the 15th month of infection) were carried out on echinococcus cysts and viscera (liver, lungs, spleen, and respective lymph nodes) of sheep with an experimental infection of Echinococcus granulosus. The echinococcus cysts differed in their development. Some of them showed normal structure, while others were in various stages of degeneration or full organization with calcification. The connective tissue capsule showed its characteristic layer structure. The liver presented strong destructive changes, particularly in tissue surrounding cysts in the stage of development. In the lungs there were interstitial and inflammatory changes with obturation of bronchioli (occasional findings). The organs of the peripheral immune system manifested morphologic changes that pointed to the presence of an immune response of mixed type.

[Cytomorphological and cytochemical studies on the multiplication of bovine reovirus type 1 in a cell culture]. / Tsitomorfologichni i tsitokhimichni prouchvaniia vurkhu razmnozhenieto na govezhdiia reovirus tip 1 v kletuchna kultura.

Parallel cytomorphologic and cytochemical studies were carried out on the replication of the bovine reovirus type 1 in the Vero cell line. It was found that a high multiplicity of infection M = 5 the first morphologic changes took place some 12 hours following infection, while at the 24th hour there appeared also the characteristic inclusion bodies. At the same time the appearance was noted of acidophile masses in the cytoplasm of some of the infected cells. The morphologic changes reached the peak values of their development at the 48th hour, and the cytoplasmic inclusions assumed a net-shaped structure of lower density. It was also found that following a short-term rise in the first 12 hours after infection there set in a general suppression of the RNA-containing material, which spread irregularly through-out the cell thus marking the nonpyroninophile viral inclusions. The desoxiribonucleic synthesis was not visibly affected, however, the nuclear chromatin remained with an unchanged structure. The viral inclusions were Feulgen PAS-negative. The hydrolytic enzymes alkaline and acid phosphatase and 5-nucleotidase were strongly inhibited after a short-term rise within the first 12 hours of infection.

[Low density lipoprotein metabolism in human fibroblast tissue cultures]. / Metabolizm lipoproteidov nizkoi plotnosti v kul'ture tkani fibroblastov cheloveka.

After the lipoproteins of low density /LDL/ were incubated at 37 degrees, they spontaneously aggregated with formation of larger particles, which were mainly absorbed by the cells of the fibroblast culture. The radioassay data showed that LDL was accumulated intracellularly. Endocytosis was not apparently the single mechanism responsible for metabolic turnover of the lipoproteins in the cells as evidenced by the low value of radioactivity of the LDL protein degradation products in the cells, as well as by alterations in the structure of the lipoproteins both absorbed on the fibroblast surface and occurring in the incubation medium.