Ultrastructure of intermediate stages in polarity reversal of thyroid epithelium in follicles in suspension culture.

Separated thyroid follicles can be maintained in suspension culture in Coon's modified F-12 medium in 0.5\% calf serum. If the serum concentration is raised to 5\%, the follicles undergo inversion in 3-5 d. During the process of inversion, epithelial cells can be observed in intermediate stages of polarity reversal. The earliest ultrastructural changes recognized are surface changes in which tight junctions and microvilli appear at the lateral margins of the cell near the medium. Later, changes in the distribution of intracellular organelles occur. The Golgi apparatus shifts towards the end of the cell facing the medium, and lysosomes shift toward the luminal end of the cell. The right junctions and microvilli at the luminal end of the cell disappear sometime after the cytoplasmic organelles rearrange. The luminal colloid disappears only after the surface changes (loss of tight junctions and microvilli) occur at the luminal end of the cell. There appears to be some regulation of the order in which changes occur during polarity reversal of the thyroid epithelial cell

Folklorist and Ethnological Research Supported by the Board for the Research of Slovakia and Subcarpathian Ruthenia in Prague during the Interwar Period

The paper focuses on selected folklorist and ethnological activities during the inter-war period, financially supported by the Board for the Research of Slovakia and Subcarpathian Ruthenia, which was established on the initiative of T. G. Masaryk as part of the newly created Slavic Institute in Prague in 1928. This institution aimed to support links between Slovakia and the so-called Czech historical lands and the expressions of “mutuality” in the scientific, cultural or ethnic and language area, etc. The Board provided grants for conducting dialectological, folklorist, geographical and other projects, e.g. for the collection initiative of F. Wollman and his students in Bratislava and Brno in 1928–1947, covering Slovak and (yet unprocessed) Moravian folk fiction. Support was also granted to the research of music culture (D. Orel, K. Hudec, F. Zagriba, etc.), the collection of anthropological and ethnographical materials (K. Chotek, K. Domin, etc.), the study of Slovak folk embroidery (V. Pražák), folklore customs and practices (P. Bogatyrev), folk wood architecture (V. Sičynskyj, D. Stránská), Slovak dialects studied, for example, by V. Vážný, member of the Board, etc. The Slovak Encyclopaedia project, today already forgotten, was not completed. Its editors included historian V. Chaloupecký and, in particular, K. Chotek who prepared the concept of the work in 1930