Global Loss of Freshwater and Salination of Sea

L

Processes Responsible for Global Freshwater Loss

L

Genotoxikus hatásra bekövetkező funkcionális és strukturális DNS változások = Functional and structural changes in DNA upon genotoxic effects

Morfológiai és biokémiai vizsgálataink arra utalnak, hogy a a genotoxikus hatások kategorizálhatók az okozott kromatin változások alapján. A kemotoxikus változások potenciális diagnosztikus jelentősége miatt vizsgáltuk a nehézfémek (elsősosrban kadmium) (Banfalvi et al., 2005), a gamma sugárzás (Nagy et al., 2004), az UVB sugárzás (Ujvárosi et al., 2007) és a carcinogén (dimetilnitrózamin) hatására bekövetkező kromatin változásokat (Trencsényi et al., 2007). Kadmium kezelés jellegzetes szakadásokat és nagy lyukakat hozott létre a sejtmagban. A gamma sugárzás preapoptotikus hatására: a. a sejtek és sejtmagok mérete megnőtt, b. DNA tartalmuk a sejtciklus minden szakaszában kisebb volt a normál kezeletlen populációhoz képest, c. a sejtciklus a korai S fázisban leállt (2,4 C értéknél), d. a kromatin kondenzálás annak fibrilláris szakaszában akadt el, e. az apoptotikus testek száma és nagysága a sejtciklus haladásávalfordítva arányos: sok apró apoptotikus testtel az S fázis elején és kevés nagy apoptotikus testtel az S fázis végén. A CHO sejtekben mért vizsgálatokat humán K562 sejteken megerősítettük. UVB sugárzás hatására a kromoszómák nem voltak láthatók, a sérülés hatására vékony összefüggő kromatin fátyol vonta be mind az interfázisos, mind a metafázisos kromoszómákat. | Morphological and biochemical studies after genotoxic treatments suggest that the consequences of various chromatin injuries can be categorized based on the assessment of injury-specific chromatin changes. Due to its diagnostic significance, we have started to determine and systematize the effects of heavy metals, primarily cadmium treatment (Banfalvi et al., 2005), gamma irradiation (Nagy et al., 2004) and UV irradiation (Ujvarosi et al., 2007). After cadmium treatment and have seen the same large extensive disruptions and holes in the nuclear membrane and sticky incompletely folded chromosomes typical for cadmium treatment (Nagy et al., 2004; Banfalvi et al., 2007). Preapoptotic changes upon γ-irradiation manifested as: (a) The cellular and nuclear sizes increased. (b) The DNA content was lower in each elutriated subpopulation of cells. (c) The progression of the cell cycle was arrested in the early S phase at 2.4 C value. (d) The chromatin condensation was blocked at its fibrillary stage. (e) The number and size of apoptotic bodies were inversely correlated with the progression of the cell cycle, with many small apoptotic bodies in early S phase and less but larger apoptotic bodies in late S phase (Nagy et al., 2004). Similar observations were made in K562 cells (Banfalvi et al., 2007). UV irradiation blocked chromatin condensation at its fibrillary stage, nuclear structures were blurred and covered with fibrillary chromatin, neither interphase nor metaphase chromosomes were visible

Antineoplastic potential of mycotoxins

Fungal toxins are secondary metabolites, in which many of them were mycotoxins, affecting eukaryotic cells with a broad range of structural and functional variety contributing to the multitude of their classification. This refers to the harmful genotoxic (mutagenic, teratogenic, and carcinogenic) effects of mycotoxins on the one hand, and their cytocidic and antineoplastic properties on the other hand. This “double edged sword” effect could be utilized against the spread of tumors in older patients when the survival is much more important than the mutagenic side effects. To decide which fungal toxins could be used as combined cytotoxic and antimetastatic agents, mycotoxins were divided into three categories: (a) highly genotoxic (mutagenic, teratogenic, and carcinogenic), (b) adversely toxic, and (c) antitumorigenic agents. Highly cytotoxic mycotoxins with tolerable side effects, combined with an antineoplastic character, could be potential candidates against metastasis. From the structure–function relationship of antimetastatic mycotoxins, only general conclusions have been drawn. The presence of ring structures containing heteroatoms, functional groups, and the cumulative presence of oxygen atoms contributed to the oxidative stress and cytotoxicity of mycotoxins. The preselection of mycotoxins excluded category (a), and only the categories (b) and (c) were considered to be potential agents against the metastatic spread of abdominal tumors in rodent metastatic tumor experiments

Effect of amphotericin B and voriconazole on the outgrowth of conidia of Aspergillus fumigatus followed by time-lapse microscopy

L