Human promyelocytic leukemia cells,. HL-60, were treated with cisplattn [cis-diamminedichloroplatinum (II)] (2 itiM, 1 h). DNA- eisplatin-protein complexes were isolated and exposed to thiourea (1M), NaCN (100 mM), diethyldithio-carbamate (500 mM), or tf-methyl-D- glucamine dithiocarbamate (500 mM) for 12 h. The release of platinum was measured by atomic absorption spectroscopy. Sodium cyanide was the most effective agent, releasing about 90% of the DNA-bound platinum. Thiourea was the least effective agent, while dithiocar- bamates exhibited an intermediate. The ability of the same group of agents to split the proteins off from the protein-cisplatin-DNA complex was also evaluated and similarly dithiocarbamate were also the most effective.
We studied the effect of the modification of focal adhesion kinase (FAK) on the growth, migration and adhesion of C3H 10T1/2 cells. Cells transfected with plasmid coding for antisense FAK displayed a low level of FAK protein. Interestingly, the transfected cells achieved a higher saturation density at confluence, and displayed reduced adhesion and enhanced emigration from a confluent layer of cells when stimulated with fibronectin. In conclusion, it can be postulated that FAK plays an important role in the mechanism of contact inhibition.
The aim of the present work was to evaluate the topography of spirochetes’ cells Borrelia burgdorferi s.s. B31 in atomic force microscope (AFM). Results: The length of spirochetes B. burgdorferi has ranged between 15.38-22.68μm. The cells of spirochetes do not constitute structures of a fixed diameter and height. Thus, in order to identify real parameters of cells, the horizontal distance and vertical distance have been used in the measurements. The average value of a spirochetes’ diameter has been estimated by taking series of measures and it is 0.40 μm. The average value of a spirochetes’ height has been estimated by taking series of measures and it is 70.14 nm. The analysis of a relation between measured parameters of spirochetes: diameter and height revealed that along with the growth of diameter of a bacteria cell, its height also grows. The average value of a fibers’ diameter has been estimated by taking series of measurements and it is 0.09 μm and the average height of fibers was 7.91 nm. Conclusions: The atomic force microscope (AFM) is a modern tool with a broad spectrum of observatory and measure abilities and is a technique which has been used in biology and microbiology to investigate the topography of surface and in the evaluation properties of cells.
The nuclear matrix bound DNA fraction of rat testis showed enrichment in repetitive sequences found in the 450 bp band after gel electrophoresis of the Mspl digested rat DNA. DNA fragments isolated from this band were cloned. DNA of the clone pMspI8 showed homology to some representatives of rat LINE sequence family, and complcxcd in vitro more efficiently with testes nuclear matrix proteins than with yeast ARS1 sequence containing the matrix association region (MAR) or DNA from an other clone, MspI19. Western blot analysis showed that MspI8 sequence interacts with testes matrix protein of about 120 kDa.