Stimulation of cellular DNA synthesis by wild type and mutant bovine papillomavirus DNA

Microinjection of recombinant plasmids containing bovine papillomavirus type 1 DNA into the nuclei of mouse C127 cells results in the stimulation of cellular DNA synthesis. Mutations in the viral E2 gene have no apparent effect on this activity even though the same mutations prevent efficient C127 cell focus formation and inhibit transactivation by this gene.     

AChemS: the beginning. Association for Chemoreception Sciences

This paper unfolds the events, the people and the times that led up to the founding of AChemS and fashioned its character during its early formative years. It describes the path over which AChemS came, going from the original assertions and denials for the need of such an organization to its later inception and nascent development. This narration highlights such topics as the debate over the need for AChemS, the role of National Science Foundation in the founding of AChemS, the derivation of the Association's name, the choice of Sarasota and the Hyatt House as the meeting site, the generation of the programs for the early annual meetings, the adoption of the bylaws, the process of incorporation and tax deferment, and the birth of the Givaudan Lectureship. Most emphatically highlighted, however, is the enthusiasm, commitment and hard work that the members of the chemosensory research community displayed in bringing AChemS to fruition.      

How the Geomagnetic Field Influences Life on Earth – An Integrated Approach to Geomagnetobiology

Origins of Life and Evolution of Biospheres - Earth is one of the inner planets of the Solar System, but – unlike the others – it has an oxidising atmosphere, relatively stable...     

The structure and properties of different types of starch exposed to UV radiation: A comparative study

The effect of UV-irradiation on four different types of native starch (corn, waxy corn, wheat and potato) have been investigated. Although the changes in the chemical structure of starch specimens were small, indicating good photostability, the samples lost adsorbed water and their crystallinity degree decreased after irradiation. Moreover, a drop in average molecular weight occurred in samples (with the exception of potato starch) as a result of main chain scission. The variations in the properties of investigated specimens of various origin were related to the differences in their structure and macromolecular arrangement. The lowest photostability among the four starches was exhibited by potato starch.     

Telomerase downregulation induces proapoptotic genes expression and initializes breast cancer cells apoptosis followed by DNA fragmentation in a cell type dependent manner

The aim of the study was to analyze the consequence of silencing genes coding for the key subunits of the telomerase complex, i.e. TERT, TERC and TP1 in human breast cancer MCF7 and MDA-MB-231cells. The transfection was performed using Lipofectamine2000 and pooled siRNAs. The cytotoxic and/or antiproliferative effect of siRNA was measured by the SRB assay, the cell cycle was analysed by flow cytometry and DNA fragmentation by TUNEL analysis. Telomerase activity was assessed by TRAP, followed by PAGE and ELISA assays. Telomerase downregulation was also assessed using qPCR in order to estimate the changes in the expression profile of genes engaged in apoptosis. It was revealed that treatment of breast cancer cells with different siRNAs (100 nM) resulted in a cell type and time-dependent effects. The downregulation of telomerase subunits was followed by reduction of telomerase activity down to almost 60 % compared to control cells. However, a significant effect was only observed when the TERT subunit was downregulated. Its silencing resulted in a significant (p < 0.05) increase of apoptosis (over 10 % in MCF7 and about 5 % in MDA-MB-231 cells, corresponding to the Annexin V assay) and DNA fragmentation (almost 30 % in MCF7 and over 25 % in MDA-MB-231 cells). Interestingly, also several proapoptotic genes were induced after the downregulation of the key telomerase subunit, including Bax, Bik or caspase-1 and caspase-14, as well as NGFR and TNFSF10 which were upregulated twice and more.