Seasonal dynamics and profiles of soil NO concentrations in a temperate forest

Plant and Soil - Soils are known to be significant sources of atmospheric nitric oxide (NO), a key compound in atmospheric chemistry. NO is a key regulating substance for inter- and intra-species...     

Inter- and Intra-Species Relationships of Greenland Halibut Reinhardtius hippoglossoides (Pleuronectidae) Based on the Analysis of Nuclear and Mitochondrial Genetic Markers

Journal of Ichthyology - Samples of Greenland halibut Reinhardtius hippoglossoides (Jordan and Snyder, 1901) from the Atlantic, Arctic, and Pacific Oceans were compared using eight microsatellite...     

Changes in Bioenergetic Functions and Performance Capacity of Athletes after Administration of a Polyphenolic Antihypoxic Agent

A study was made of the effects of a polyphenolic antihypoxic agent on respiration in isolated mitochondria and homogenates of skeletal muscles and on the bioenergetic functions and performance capacity of runners. Polarographic analysis showed that preincubation of mitochondria isolated from skeletal muscles with the antihypoxic agent inhibited glutamate oxidation more than twofold in state 4. In homogenates of skeletal muscles, the antihypoxic agent in the presence or absence of an uncoupler strongly inhibited or slightly stimulated glutamate oxidation in the initial mitochondrial state, respectively. Thus, the antihypoxic agent inhibited mitochondrial ATPase but did not change the ATP synthase activity or exert a direct effect on the respiratory chain. The antihypoxic agent administered to runners at a concentration of about 30 mg/kg body mass 1 h prior to exercise at maximum power with a maximum duration of 1–10 min allowed higher acidification but did not affect the major bioenergetic functions such as O₂ consumption, excess CO₂ production, O₂ debt, and O₂ demand. The agent substantially increased the performance capacity of runners during exercise with a maximum duration of 3–10 min. Under competition conditions, administration of the agent to runners improved the results by 2–6% in 200- to 10000-m races.     

Synthesis, spectral properties, and antitumor activity of a new axially substituted phthalocyanine complex of zirconium(IV) with citric acid

The new axially substituted phthalocyanine (pc) complex of zirconium(IV) with citric acid is reported. It has been shown that the replacement of two Cl-atoms with two citric acid fragments takes place as the result of the reaction between [ZrCl2(pc)] and citric acid. The complex [Zr(citrate)2(pc)] was formed. The spectroscopic properties of the synthesized compound in DMSO, RPMI 1640 medium with and without fetal calf serum (FCS), H2O, and buffer (Tris) solutions have been described. Antitumor activity of this compound has been studied. The cytostatic activity was observed in the concentration range of 6.1-9.0x10(9) molecules [Zr(citrate)2(pc)]/cell and occurred in 4-6 h after treatment with [Zr(citrate)2(pc)] solution.     

Heat-stress-dependency and developmental modulation of gene expression: the potential of house-keeping genes as internal standards in mRNA expression profiling using real-time RT-PCR

The potential of different house-keeping genes for their use as internal standards of gene expression under changing environmental conditions and in different organs of plants was assessed. Using real-time PCR mRNA levels were precisely quantified for preselected actin and ribosomal protein genes in Arabidopsis thaliana (L.) Heinh. and Nicotiana tabacum L. grown at normal temperature and following heat stress. In tobacco leaves the mRNA levels of the constitutively expressed ribosomal protein gene Nt-L25 and the actin genes Nt-ACT9 and At-ACT66 were strongly reduced (to approximately 10%) during heat stress. Heat stress applied at the temperature optimum (37 degrees C) for elicitation of a heat stress response to Arabidopsis leaves resulted in a strong induction (several thousand-fold) of the mRNA heat shock protein genes, At-HSP17.6 and At-HSP18.2. Concomitantly, the mRNA levels of constitutively expressed actin 2 (At-ACT2) and ribosomal protein L23 (At-L23a) genes were reduced to approximately 50% of the levels in leaves incubated at room temperature. Conversely, under severe heat stress conditions (44 degrees C), the induction of At-HSP17.6 and At-HSP18.2 mRNAs was insignificant, the mRNA levels of At-ACT2 remained at approximately the same levels as in leaves incubated at room temperature, whereas the mRNA level of At-L23 declined. The mRNA levels of At-ACT2 and At-L23a examined in stem, flower and siliques of Arabidopsis plants grown under non-stress condition showed differential alterations; the mRNA level of ribosomal protein L23 correlates with the metabolic activity of tissues. The potential use of house-keeping gene expression as standards in expression profiling and the mechanisms modulating the mRNA levels are discussed.