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Background. Side effects of endocrine therapy with tamoxifen (TAM) reduce the quality of life of patients with breast cancer (BC) and adversely affect treatment compliance. Against the background of treatment of BC with TAM, the risk of developing endometrial hyperplasia (EH) increases. At the moment, algorithms for monitoring patients receiving TAM by an obstetrician-gynecologist have not been developed and approved. There are also divergent opinions of experts regarding the diagnosis and management of patients in the detection of EH. This article presents the results of the final stage of the study in 2017–2022 – a survey study. The purpose of this study was to assess adherence to endocrine therapy and satisfaction with observation by a gynecologist of women with BC after 5 years of observation and their relationship with the identified early associated polymorphisms of the CYP2D6, CYP3A5, CYP2C9 and ABCB1 genes. Materials and methods. 54 patients with BC, out of 120 who had previously passed the first pharmacogenetic stage of the study, were interviewed with specially designed questionnaire. Due to the small sample size, delta percentages (∆%) were used in each comparison group with a difference threshold of 5%. To assess associations with the studied genetic polymorphisms, previously obtained significant associations of adverse drug reactions with pharmacogenetics in the same patients were used. Results. The prevalence of all adverse drug reactions (ADRs), with the exception of EH, was higher in the group of patients who canceled TAM. Over 5 years of follow-up, 57.4% of patients were regularly observed by an obstetrician-gynecologist, 42.59% of patients visited a gynecologist less than once a year. Of all the respondents, 53.7% of patients are satisfied with the regularity and quality of dispensary observation by an oncologist, 33.33% of patients are satisfied with the regularity and quality of dispensary observation by an obstetrician-gynecologist. All studied ADRs (EH, hot flashes, asthenia, bone pain and dyspepsia) associated with various genetic polymorphisms, prevailed in the group of patients who stopped taking TAM due to drug intolerance (∆%: 25.72, 6.97, 4.81, 6.97 and 24.52 respectively) compared with the TAM-group. Conclusion. The results obtained confirm the role of the studied genetic polymorphisms in the development of ADRs of TAM, but only systemic (hot flashes, asthenia, bone pain and dyspepsia). With regard to endometrial hyperplasia, no significant differences were obtained, which requires more extensive studies.

The modification particularities of the structural and functional state of the inner mitochondrial membrane of the rat liver and myocardium were observed in conditions of artificial hypobiosis, which was created using hypoxic and hypercapnic gas medium with a body temperature reduction. Under the artificial hypobiosis the activity of NAD·H-generating enzymes of the Krebs cycle of the liver mitochondria decreases. The established changes of the enzymes activity and cytochromes content of the inner mitochondrial membrane indicate the decrease of the oxidative activity of a respiratory chain, that can be limited on a terminal (cytochrome c oxidase) site and leads to the decrease (by 49% at an average) of the H+-ATPase activity of the liver mitochondria. Under the artificial hypobiosis the detected increase of the succinate-KoQ-oxidoreductase activi ty (by 65% at average) causes the maintaining of the functional activity of a mitochondrial respiratory chain, considering the high (relative to control) cytochrome c oxidase and H+-ATPase activities of the mitochondria of the rats' myocardium. The structural changes of the inner mitochondrial membrane of the liver and myocardium in experimental conditions are accompanied by the increase of hydrophobicity of tryptophan residues microenvironment and the intramolecular modifications of protein molecules. [ABSTRACT FROM AUTHOR]

MicroRNAs are short non - coding RNAs that correlate with the levels of platelet activation which can be utilized as a biomarker when guiding P2Y12 inhibitors therapy. In this literature review, the perspectives of microRNA as a novel biomarker are discussed when guiding P2Y12 inhibitors therapy among the patients with coronary artery disease.

It was concluded on the grounds of spectrophotometric analysis of cytochrome P450 electrolysis products that cytochrome P450 unlike other hem-containing proteins is not reduced on the cathode. At the potential -1.5V it is reduced simultaneously with the transformation into cytochrome P420. Inactivation in the electric field on the electrode surface is irreversible. When the potential is above -1.4V no inactivation of cytochrome P450 takes place.

The work presents the results of the first stage of the study on the valent and structural state and function of the iron atoms in the donor-acceptor environment of the photosynthetic reaction centres of purple bacteria. 57Fe was introduced by cultivating the microorganisms in a medium enriched in this isotope. At 77 K the maxima observed in the Mössbauer spectra in intact freeze-dried cells at a speed of +2 mm/s and --1 mm/s are attributed to doublets 1.11 with the isomer ahifts of 1.3 and 0.5 mm/s respectively and the constants of the quadrupole splitting (Q.S.) of 2 mm/s and 2.2 mm/s. These are presumed to arise from cytochromes type c. The Mössbauer parameters of the intense assymetric quadrupole-split doublet of a more complex nature in the mid of the spectrum with line widths of 0.5 to 7.0 mm/s and 0.5 to 1.5 mm/s fit to these of bacterial ferredoxin. From the analysis of the control and dithionite-treated samples of the temperature dependency of the observable parameters over a temperature range of 77 to 300 K it can be concluded that in cells the iron atoms are present in various valency and spin states and the relation between the redox states of the iron atoms is dependent, in particular, on the age of the culture. The Mössbauer spectra of the cell fragments indicate that most of the intracellular iron, first of all the heme iron, is bound to the fraction of photosynthetic membranes.

A mechanism of charge transfer into the hydrophobic membrane zone is proposed. The mechanism proposed includes transfer of radical state in the long chain hydrocarbon molecules of membrane lipids. In connection with this phenomenon mechanisms of electron transfer by short pi-systems formed in the fatty acid chains are discussed, as well as mechanisms of some oxidizing processes in microsome and mitochondria membranes.

The results of histochemical, histoenzymological, and fluorescence microscopy studies of the conductive tissue of the heart in acute myocardial infarction in 30 fatal cases are presented. Focal decrease in redox and hydrolytic enzymes, monoaminoxidase, and cholinesterase in elementa of the conduction system as well as changes in the pattern of fluorescence of the specific muscle cells were found. The intensity of metabolic lesions was more pronounced at early stages of myocardial infarction in those cases where the conducting pathways were proximal to the foci of necrosis.

It was shown that 35% of the peptide groups, which form the right alpha-helices, are presented in the soluble fraction of cytochrome b5. The incorporation of cytochrome b5 into egg lecithine liposomes increases the number of alpha-helices up to 51%. On the contrary, the cytochrome incorporation into microsomal lipid liposomes slightly increases the degree of spiralization. The reduction of cytochrome b5 haem slightly decreases alpha-helices in the soluble haemoprotein as well as in the one incorporated into the artificial membrane irrespective of its phospholipid content.

Red absorption band and fluorescence of an artificial chlorophyll-albumin complex (MW 220 kD) resemble the spectroscopic properties of P 680 shifts toward longer waves with the solution pH from 7.3 to 2.5. It is suggested that light induced pH under in vivo conditions may cause similar changes which may lead to changes in the distribution of excitation energy within the pigment system of photosynthesizing organisms.

The respiration activity and the cytochrome content of the cells of Endomyces magnusii were studied during growth on a medium with 0.6 per cent sucrose. The rate of oxidation, the ration between the activities of respiration and fermentation, the quantitative content and molar ration of cytochromes remained almost the same in the course of growth. Only cytochrome oxidase was involved at the terminal stage of oxidation in the course of growth: the respiration of the cells was inhibited by 90-95 per cent by cyanide, but was resistant to the action of salicyl hydroxamate which was an inhibitor of an alternative pathway of oxidation. Mitochondria from cells harvested at the middle of the logarithmic growth phase almost did not differ in parameters from mitochondria relative to the stationary growth phase: they were tightly coupled and had the theoretical effectiveness of oxidative phosphorylation typical of oxidation of NAD-dependent substrates. All the three points of energy coupling are supposed to function at the earliest phases of growth. Endomyces magnusii differs from other yeasts in following characteristics: the absence of glucose repression, a high constant level of respiration activity, the maximum effectiveness with which the coupling apparatus functions at the earliest phases of growth, and the absence of alternative oxidation pathways.

Under gamma-irradiation of frozen water--glycerol solutions of ferrocytochrome b5 at 77 degrees K ferrocytochrome b5 in a non-equilibrium state is formed. Its absorption and MCD spectra are displaced by 1,5 nm to the long wave region. When the temperature is increased to 140 degrees K the non-equilibrium form of reduced protein is relaxes. A comparison of optical characteristics of ferrocytochrome b5 in equilibrium and non-equilibrium states shows that the structure of the protein active centre slightly depends on the state of metal oxidation. It is concluded on the basis of earlier published data on low temperature reduction of different electron transport proteins that a small effect of the oxidation state of a metal ion on the active centre structure is a common property of all the electron transport proteins. This phenomenon makes these systems an effective carrier of electrons.