Role of the Nitric Oxide (NO) in the Regulation of Steroidogenesis in Placenta During Physiological Pregnancy and Preeclampsia (Experimental Study)

The aim of the study was to establish the role of nitric oxide (NO) in the regulation of steroidogenesis in the placenta during physiological pregnancy and experimental preeclampsia (PE) in rats. EPR centers of the placenta, free NO and its metabolites were determined by the Electron Paramagnetic Resonance (EPR) method. At the last stage of pregnancy in the EPR spectra of the rats’ placenta with PE alterations of the signals intensity of mitochondrial steroidogenic electron transport proteins were detected: the FeS-centers of adrenodoxin decreased, the ferricytochrome P-450 increased, the free NO content decreased, and the complexes of NO with heme (HbNO) and non-heme iron (FeSNO) were detected. These data indicate the violation of placental steroidogenesis, which is confirmed by a decrease in the level of progesterone in blood. Therefore, the nitrosylation of mitochondrial proteins is an important redox-dependent mechanism of regulation of the intensity of steroidogenesis.

Note on Appearance of Zigzak Type Self Similarity in Flying Bird Flocks Performing Directional Collective Motions in Mild-Weather Conditions

It is argued here that very regular and coordinated patterns of bird flocks in motion, in quiescent weather conditions, can be expected to first emerge upon minimal configurational entropy production for the flock(s) vs. air mass couple. This is immediately to accept if certain ultralow friction conditions apply, with the air-bird flock friction coefficient f approaching minimal values. Then, quite geometrically coordinated, apparently self-similar zigzak type patterns show up during the flock’s motion. Otherwise, the coherence of the flying patterns is lost, the flocks become disorganized, characteristic of fairly large configurational-space (individual positions involving) entropy, and their average acceleration supposedly gets on appreciable nonzero values. The oversimplified analysis performed in this study does not assume really far-from-equilibrium (thermo)dynamic conditions to occur.

Advances in EPR Dosimetry in Terms of Retrospective Determination of Absorbed Dose in Radiation Accidents

The electron paramagnetic resonance measurements of dosimetric signals originating from radicals generated under the influence of ionizing radiation allow to determine the dose absorbed by the casualties of radiation accidents. The study material can consist of victim’s teeth, bones or nails. Also human hair and mineral glass from personal electronic devices, that people had in the moment of accident, are considered to be useful in dosimetry. Although X-band (9.4 GHz) spectrometers predominate, Q-band devices (34 GHz) enable to increase the sensitivity of measurements and reduce the size of specimens, whereas L-band machines (1.1 GHz) are suitable for in vivo dosimetry. The EPR tooth enamel dosimetry has been used many times to assess the cumulative radiation dose and health risk in people living in areas contaminated due to the radiation accidents and to determine the unknown absorbed doses in patients after the overexposures during radiotherapy treatment.