The Effect of Pulsed Magnetic Fields on the Production of Reactive Oxygen Species by Neutrophils

Biophysics - It has been shown that pulsed magnetic fields (the first mode: pulse duration of 2 ms, frequency repetitions of 6.25 Hz, the pulse was bell-shaped; and the second mode: pulse duration...     

The Effect of Gases on the Structural Integrity of Ice that Forms when Water and Cryoprotective Solutions Are Frozen: An Optical-Microscope Study

Biophysics - The effects of air, helium, argon, xenon, and sulfur hexafluoride on the integrity of the ice structure formed when water and a cryoprotective solutions were frozen in the temperature...     

A new species and molecular phylogeny of Brazilian succulent Euphorbia sect. Brasilienses

A new species of Euphorbia sect. Brasilienses V.W. Steinm. & Dorsey is described. Euphorbia tetrangularis Hurbath & Cordeiro is endemic to the Serra de Montevidéu, a part of the Espinhaço Range located in the state of Minas Gerais, Brazil. It differs from other species within the section based on the following characters: 4-ribbed branches, green cyathia, and green cyathial glands with erect appendages. This new species would qualify as critically endangered (CR) according to IUCN criteria. An inferred phylogeny based on a combined dataset of nuclear (ITS1) and plastid regions (psbA-trnH, trnC-ycf6, matK, atpI-atpH, psbJ-petA, trnQ-rps16?×?1) confirms the monophyly of Euphorbia sect. Brasilienses and supports the recognition of E. tetrangularis. The phylogeny also suggests that this group probably underwent a recent radiation.     

Characterization of several members of the thiol oxidoreductase family

There is no doubt as to the important role that free radicals and reactive oxygen species play in the cell. Disturbances in intracellular redox proteins are often accompanied by common pathologies, including diabetes, myocardial infarction, neurodegeneration, bronchopulmonary diseases, cancer, etc. Numerous antioxidant enzymes are related to various redox biology systems, the thiol oxidoreductase superfamily playing a key role. The superfamily includes thioredoxin, glutaredoxin, peroxiredoxin, protein disulfide isomerase, and glutathione peroxidase families and a number of other proteins. Apart from their antioxidant function, thiol oxidoreductases are capable of recycling hydroperoxyde to produce specific disulfide bonds within and between proteins, which significantly expands their functional range. In view of this, it is a topical problem of redox biology to characterize the superfamily members biochemically and to study their functional mechanisms.     

Phospholipids of liver cell nuclei during hibernation of Yakutian ground squirrel

In hibernating Yakutian ground squirrels S. undulatus, the content of total phospholipids in the nuclei of liver increased by 40% compared to that in animals in summer. In torpid state, the amount of sphingomyelin increased almost 8 times; phosphatidylserine, 7 times; and cardiolipin, 4 times. In active “winter” ground squirrels, the amount of sphingomyelin, phosphatidylserine, and cardiolipin decreased compared to the hibernating individuals but remained high compared to the “summer” ones. The torpor state did not affect the amount of lysophosphatidylcholine and phosphatidylinositol.     

The effect of weak magnetic fields on the chemiluminescence of human blood

Exposure of heparinized human venous blood that was diluted with a phosphate buffer to a combination of a static magnetic field (42 µT) and a weak (amplitude range 108–3440 nT) variable low-frequency (1, 4.4, and 16.5 Hz, ratio of amplitudes 6: 1: 1.6, respectively) magnetic field collinear to the static magnetic field enhanced blood chemiluminescence that was induced by the addition of luminol or lucigenin at physiological temperature. The free-radical scavenger edaravone (MCI-186) and apocynin, an inhibitor of NADPH oxidase, reduced the intensity of blood chemiluminescence and alleviated the effects of the magnetic fields.     

Salicylic acid influences the protease activity and posttranslation modifications of the secreted peptides in the moss Physcomitrella patens

Plant secretome comprises dozens of secreted proteins. However, little is known about the composition of the whole secreted peptide pools and the proteases responsible for the generation of the peptide pools. The majority of studies focus on target detection and characterization of specific plant peptide hormones. In this study, we performed a comprehensive analysis of the whole extracellular peptidome, using moss Physcomitrella patens as a model. Hundreds of modified and unmodified endogenous peptides that originated from functional and nonfunctional protein precursors were identified. The plant proteases responsible for shaping the pool of endogenous peptides were predicted. Salicylic acid (SA) influenced peptide production in the secretome. The proteasome activity was altered upon SA treatment, thereby influencing the composition of the peptide pools. These results shed more light on the role of proteases and posttranslational modification in the “active management” of the extracellular peptide pool in response to stress conditions. It also identifies a list of potential peptide hormones in the moss secretome for further analysis.     

Protective effect of low-intensity laser irradiation under acute toxic stress

We studied how short-term preexposure of the thymus zone in male outbred NMRI mice to helium-neon laser light (632.8 nm, 0.2 mW/cm²) affects the activity of cells of the immune system under acute toxic stress. The stress was modeled by introducing a bacterial lipopolysaccharide that significantly enhanced the production of a number of cytokines in macrophages: interleukins 1α, 1β, 6, and 10, and tumor necrosis factor TNF-α. Single exposure of healthy mice to laser light did not cause any significant change in the production of cytokines and nitric oxide in cells but increased the production of the heat shock proteins HSP25, HSP70, and HSP90. Nonetheless, if mice were exposed to red light before inducing toxic stress, then the production of almost all the cytokines studied and nitric oxide was noticeably normalized. Moreover, the production of the heat shock proteins studied was also normalized. Thus, preexposure of a small region of the animal skin surface to laser light markedly decreased the toxic effect of lipopolysaccharide.     

The stimulating effect of recombinant cytokine LIF on the mouse blastocysts during implantation

The effect of recombinant LIF cytokine (Leukemia inhibitory factor) on the isolated mouse embryos at the stages of middle and late blastocyst has been investigated. We have demonstrated here that this agent is necessary in vitro at the stage of normal trophoblast formation after the blastocysts hatch from zona pellucida. This cytokine (10 ng/ml) caused intensification of adhesion and proliferative activity of the trophoblast cells. This is important for intercellular interactions with endometrium and for invasion of embryos into the uterus. The recombinant LIF insignificantly influenced cells of the inner cell mass.     

Hydrolysis of various peptides and proteins in weak permanent and low frequency fluctuating magnetic fields

It was shown that weak combined magnetic fields (constant field 25-130 microT; variable field 0.01-0.2 microT; the range of effective frequencies of the alternating component 1-10 Hz) substantially increase the rate of hydrolysis of some proteins and peptides (eight various sequences). The concentration dependence of the dynamics of the process and the dependence of the magnitude of the effect on the parameters of the magnetic field. It was found that: (1) the effect is transmitted through a solvent preliminarily treated by magnetic fields and (2) the effect occurs in the presence of inhibitors of proteases and enzymes inactivating peroxides (catalase and horse radish peroxidase with substrate).