The Ability of Cyanobacterial Cells to Restore UV-B Radiation Induced Damage to Photosystem II is Influenced by Photolyase Dependent DNA Repair

Damage of DNA and Photosystem-II are among the most significant effects of UV-B irradiation in photosynthetic organisms. Both damaged DNA and Photosystem-II can be repaired, which represent important defense mechanisms against detrimental UV-B effects. Correlation of Photosystem-II damage and repair with the concurrent DNA damage and repair was investigated in the cyanobacterium Synechocystis PCC6803 using its wild type and a photolyase deficient mutant, which is unable to repair UV-B induced DNA damages. A significant amount of damaged DNA accumulated during UV-B exposure in the photolyase mutant concomitant with decreased Photosystem-II activity and D1 protein amount. The transcript level of psbA3, which is a UV-responsive copy of the psbA gene family encoding the D1 subunit of the Photosystem-II reaction center, is also decreased in the photolyase mutant. The wild-type cells, however, did not accumulate damaged DNA during UV-B exposure, suffered smaller losses of Photosystem-II activity and D1 protein, and maintained higher level of psbA3 transcripts than the photolyase mutant. It is concluded that the repair capacity of Photosystem-II depends on the ability of cells to repair UV-B-damaged DNA through maintaining the transcription of genes, which are essential for protein synthesis-dependent repair of the Photosystem-II reaction center

Receptorok a belsőfül és a vertebrobasilaris erek primer szenzoros rostjain = Receptor expression of primary sensory nerves around the inner ear and vertebrobasilar arteries

Kimutattuk, hogy a VR1 receptorok a ggl. n. trigeminiből eredő és a vertebrobasilaris rendszert ellátó szenzoros rostokban megtalálhatók. A VR1 receptorokkal jelölt primér szenzoros rostokat nyomon követtük a BA, AICA, SMA, és az a. radiolaris felszínén. A VR1 receptorok a szenzoros neuronokon kolokalizációt mutatnak a SP-vel és trkA receptorokkal. Igazoltuk a trkA receptorok jelenlétét a cochleaban a postnatalis időszakban. A trkA receptorok szenzoros rostokhoz kötöttek. Igazoltuk, a stria vascularis marginalis setjeiben a VR1 receptorok jelenlétét. A VR1 receptor a marginalis sejtekben kolokalizációt mutat -plazma membran calcium ATPase-val. Kolokalizácót igazoltunk a marginalis sejtek basolateralis oldalán a VR1 és Na+-K+ ATPase között is. A VR1 receptorok és a Na+-K+ ATPase kolokalizációt mutatott a stria vascularis capillarisai körül is. A VR1 receptorok a szöveti pH változásokkal, nyomásváltozásokkal, ill. hőmérsékleti ingadozásokkal hozhatók ingerületbe, s ily módon befolyással lehetnek a cochlean belüli ozmotikus változáskora, ill. pH értékek beállítására. A VR1 receptorokban bekövetkezett morfológiai és funkcionális károsodás a cochlea nyomásviszonyainak megváltozását eredményezhetik, amely eltérések a Méni?re szindróma és Méni?re betegség tünet együttesét hozhatják létre. A VR1 receptorok a Ca++-ion és Na+-K+-ion háztartással való kapcsolata révén oki tényezővé léphet elő egyéb idegi jellegű halláscsökkenések patomechanizmusában is. | This research has demonstrated that VR1 receptors are found sensory fibers originating in ggl. n. trigemini and supplying the vertebrobasilar system. Primary sensory fibers marked with VR1 receptors were tracked on the surface of BA, AICA, SMA, and a. radiolar. VR1 receptors demonstrate co-localization on sensory neurons with SP and trkA receptors. The results have been verified the presence of trkA receptors in the cochlea in the postnatal period. TrkA receptors are bound to sensory fibers. Results have verified the presence of VR1 receptors in marginal cells of the stria vascularis. VR1 receptors show co-localization in the marginal cells with plasma membrane calcium ATPase. Co-localization has also been detected on the basolateral side of the marginal cells between VR1 and Na+-K+ ATPase. VR1 receptors and Na+-K+ ATPase as well demonstrated co-localization around the capillaries of the stria vascularis. VR1 receptors can be stimulated by pH changes in the tissue, changes of pressure, and temperature fluctuations, and this way can affect osmotic changes as well as pH value setting within the cochlea. Morphological and functional impairment in VR1 receptors may result in changes of pressure in the cochlea, which can create the symptoms of Méni-re-s syndrome and Méni-re-s disease. Due to their connection with Ca++-ion and Na+-K+-ion balance, VR1 receptors can become causal factors in the patomechanism of other neurological hearing empairments

Scanning drift tube measurements of electron transport parameters in different gases: argon, synthetic air, methane and deuterium

Measurements of transport coef cients of electrons in a scanning drift tube apparatus are reported for different gases: argon, synthetic air, methane and deuterium. The experimental system allows the spatio-temporal development of the electron swarms (‘swarm maps’) to be recorded and this information, when compared with the pro les predicted by theory, makes it possible to determine the ‘time-of- ight’ transport coef cients: the bulk drift velocity, the longitudinal diffusion coef cient and the effective ionization coef cient, in a well-de ned way. From these data, the effective Townsend ionization coef cient is determined as well. The swarm maps provide, additionally, direct, unambiguous information about the hydrodynamic/ non-hydrodynamic regimes of the swarms, aiding the selection of the proper regions applicable for the determination of the transport coef cients

Interaction of nanoparticles with biological systems

Nanoparticles (NPs) are literally and figuratively infiltrating all fields of biological research. They are sophisticated tools that can be customized, either by smart engineering or by the attachment of specific ligands, to match the requirements of a particular task. Through their inherent and functionalized properties they are the basis for new developments while enhancing the efficiency of already existing techniques or rendering methods to be more specific. They provide new approaches for therapeutic applications and brand new platforms for diagnostic processes. In this review we provide an insight into the practical applications of NPs, emphasizing their use in biosensing, bioimaging, biomolecule delivery systems and enzyme immobilization. Since the interest in the interactions of NPs and biological systems is fairly new, we also elaborate on the drawbacks of their practical applications by reporting their potential toxicity in in vitro and in vivo systems

Statistical Analysis of the Hydrological and Hydrometeorological Characteristics of the Upper Tisza Basin

Tisza is the largest water base in the eastern part of Szabolcs-Szatmár-Bereg County, in north-eastern Hungary, and its indirect use is mainly associated with agriculture. Our work investigates the hypothesis that decrease in water levels and water discharges of the Upper Tisza in recent decades, together with the incision of the riverbed and the precipitation falling in the area, have an impact on the groundwater level of the Szatmár-Bereg Plain. In our study, data from three water gauges located between the settlements of Tiszaújlak and Vásárosnamény and data from groundwater level monitoring wells (MW) and Hydrometeorological (HMS) stations on the Szatmár-Bereg Plain were compared using statistical methods in Past 4.11 software. The aim of the current study was to identify the strategic steps that need to be taken by the organisations responsible for water management in the Upper Tisza basin in the light of the changes in hydrological, hydrometeorological, and meteorological factors. To ensure that the region has sufficient water supplies for the next decade, appropriate water management and agricultural strategies could be the solution

A unified optical damage criterion based on the probability density distribution of detector signals

Various methods and procedures have been developed so far to test laser induced optical damage. The question naturally arises, that what are the respective sensitivities of these diverse methods. To make a suitable comparison, both the processing of the measured primary signal has to be at least similar to the various methods, and one needs to establish a proper damage criterion, which has to be universally applicable for every method. We defined damage criteria based on the probability density distribution of the obtained detector signals. This was determined by the kernel density estimation procedure. We have tested the entire evaluation procedure in four well-known detection techniques: direct observation of the sample by optical microscopy; monitoring of the change in the light scattering power of the target surface and the detection of the generated photoacoustic waves both in the bulk of the sample and in the surrounding air