Different Levels Of Structural Organization Research Articles

Histological and histochemical changes in liver tissue of young rats with hyperhomocysteinemia

Annotation. The decisive place in the synthesis and subsequent metabolism of homocysteine (Hcy) belongs to the liver, where, in particular, transsulfation and remethylation processes take place. It has been proven that organ tissue damage can cause hyperhomocysteinemia (HHcy). Changes in the structural and functional parameters of the liver tissue under the conditions of a significant and long-term increase in blood serum Hcy are still insufficiently studied. Modeling the state of chronic HHcy and studying the features of histological changes in liver tissue at different levels of structural organization is an urgent task. The aim of the research is to study morphological and histochemical changes in the liver tissue of young rats with HHcy. The experiment was carried out on 22 white non-linear young – aged 1-2 months, male rats. During the study, the animals were divided into two groups – control and experimental. Chronic persistent HHcy was modeled by administering thiolactone Hcy in a dose of 200 mg/kg of body weight intragastrically for 60 days to the rats of the experimental group. Histological preparations were studied using a SEO SСAN light microscope and photo-documented using a Vision CCD Camera. Succinate dehydrogenase was detected histochemically according to the Nakhlas method. To study the specifics of glycogen accumulation in hepatocytes, sections were stained using Schiff's reagent, after preliminary treatment with iodic acid (PAS reaction) in the Shabadash modification. It was established that the administration of thiolactone Hcy to young rats at a dose of 200 mg/kg led to impaired blood supply, destructive changes and growth of connective tissue in the liver. Moderate changes in the hepatocyte plates organization, a decrease in the mitotic activity of hepatocytes, and the development of fatty and vacuole-hydropic dystrophy were recorded. Histochemical studies of the liver of animals of the research group established a decrease in the activity of the succinate dehydrogenase enzyme and glycogen content in hepatocytes.

Synthesis and Spectroscopic Properties of Selected Acrylic and Methacrylic Derivatives of 2-Mercaptobenzothiazole

One of the most basic properties of chemical compounds is structural symmetry or asymmetry. This property can be considered at different levels of structural organization. The physical, chemical, biological, and technological properties of organic compounds depend on their chemical structure and are systematically related to it. The presented paper is focused on the synthesis and study of the spectroscopic properties of selected photoinitiators from the acrylate and methacrylate derivatives of 2-(benzothiazolylthio)ethyl. The indicated compounds can find potential application in medicine. The 2-(benzothiazolylthio)ethyl acrylate and methacrylate derivatives were characterized using infrared spectroscopy (IR) and nuclear magnetic resonance (NMR) spectroscopy. Their spectroscopic properties were determined on the basis of UV–Vis spectra. The calculated DFT energies and Frontier Molecular Orbitals calculations of the studied compounds were proved to be consistent with the experimental observations. The results have showed that the introduction of the ethoxy substituent increases the reactivity of the compounds and results in the slight bathochromic shift (~19 nm) of the absorption spectra maxima.

An open call for contributions to a special issue of Biophysical Reviews highlighting the research themes of VII Congress of Russian Biophysicists 2023.

We announce a call for contributions to a Special Issue of Biophysical Reviews associated with the VII Congress of Russian Biophysicists (to be held in Krasnodar, Russia, 17-23 April 2023). The Congress is the main biophysical meeting held within Russia and is organized every four years. The Congress will focus on both the physical principles and mechanisms of biological processes occurring at different levels of structural organization, from molecular to cellular to organism and to population levels. The Special Issue will accept reviews on topics from molecular biophysics, structure and dynamics of biopolymers, biophysics of the cell, energy transformation mechanisms, biophotonics, ecological biophysics, and medical biophysics, following the sections of the Congress. The VII Congress of Russian Biophysicists is supported by International Union of Pure and Applied Biophysics (IUPAB). Here we describe main topics and sections of the coming event, the paper types for the journal issue, and the key deadline dates.

Linguistic and Psychometric Validation of the Ukrainian Translation of the Inventory of Personality Organization-Revised (IPO-R-UKR)

The cultural adaptation of the psychodiagnostic questionnaire involves the implementation of a “double-blind” translation with subsequent linguistic validation considering both linguistic differences and the symbolism of the authors’ statements. Then, based on the survey data of respondents, various psychometric indicators of the questionnaire are checked. The development of Ukrainian-language questionnaires in the psychodynamic paradigm is crucial for creating an appropriate scientific evidence base of therapeutic methods and for psychotherapeutic practice to equip specialists with reliable diagnostic tools. The research objective is to carry out a professional translation of The Inventory of Personality Organization-Revised (IPO-R) into Ukrainian, followed by checking for linguistic validity and psychometric properties. The questionnaire showed high psychometric performance in the long (IPO; Lenzenweger et al., 2001) and short (IPO-R; Smits et al., 2009) versions and foreign language adaptations. It is widely used in psychological research, the theoretical and methodological basis of which is the psychoanalytic concept, in particular, the theory of O. Kernberg (Kernberg, 1986) on different levels of structural organization of personality, which underlies the psychoanalyst's choice of a strategy for working with a client. The created test version of the IPO-R-UKR questionnaire passed the stages of two-sided "double-blind" translation and was agreed upon by a team of philologists and psychologists. Based on the results of 1152 people participating in the empirical research, we have proven IPO-R-UKR to have a similar to the original two-factor structure, good internal consistency of the scales, construct convergent, and criterion validity. Thus, IPO-R-UKR can be used in practical psychological activities and scientific research to identify criteria for the structural organization of personality, such as reality testing, identity diffusion, and mechanisms of psychological defenses, as well as for screening diagnostics of the structural level of personality organization by Kernberg (1986).

Трансформація гумусових речовин дерново-підзолистого ґрунту за тривалого внесення добрив

The article reflects the results of a study of the regularities of the transformation of humic substances at different levels of structural organization during long-term fertilization against the background of liming of podzolic sandy loamy soil in a field experiment in Western Polissya of Ukraine. It was found that the low content of chemically active organic substances in the humus composition of podzolic soils, caused by the zonal features of humus formation, can be positively corrected by applying fertilizers. Long-term use of organic and mineral fertilizers intensifies the process of new formation of humic acids and the formation of their mobile forms – the ratio of Cha-1 / Cfa-1 is 0.28 in the control without fertilizers and 0.33–0.88 in the variants of fertilization against the background of liming. With an organo-mineral fertilizer system, the most favorable conditions are formed for the humification of organic substances however, the type of humus remained fulvate – the Cha / Cfa ratio is 0.93 in the control variant and 0.41 – against the background of liming. Also, the application of fertilizers had an effect on the redistribution of the polydispersity of humic acids, which was characterized by a decrease in the heterogeneity of the composition of hydrophobic molecular aggregates. In a wide range of 1800 cm-1 to 2500 cm-1, a change in the direction of the line of the integral spectrum of soil humic acids under the application of CaCO3 from left to right was found, which is associated with a change in molecular parameters. Based on the results of chromatographic analysis, it was established that the profiles of the molecular distribution of humic acids podzolic soil correspond to the humus substances class. The first fraction is characterized by the formation of ion associates of larger molecules of polar composition. The recovery of humic acids occurred mainly due to high-molecular structures, which is the most sensitive to the application of fertilizers.

Biological Computation and Compatibility Search in the Possibility Space as the Mechanism of Complexity Increase During Progressive Evolution

The idea of computational processes, which take place in nature, for example, DNA computation, is discussed in the literature. DNA computation that is going on in the immunoglobulin locus of vertebrates shows how the computations in the biological possibility space could operate during evolution. We suggest that the origin of evolutionarily novel genes and genome evolution constitute the original intrinsic computation of the information about new structures in the space of unrealized biological possibilities. Due to DNA computation, the information about future structures is generated and stored in DNA as genetic information. In evolving ontogenies, search algorithms are necessary, which can search for information about evolutionary innovations and morphological novelties. We believe that such algorithms include stochastic gene expression, gene competition, and compatibility search at different levels of structural organization. We formulate the increase in complexity principle in terms of biological computation and hypothesize the possibility of in silico computing of future functions of evolutionarily novel genes.

Морфометричні показники міокарда щурів при дії загальної гіпотермії

Hypothermia is a situation in which the internal body temperature drops below 35 degrees Celsius. The article presents the relevance, theoretical aspects and features of the action of general hypothermia on the heart in general and cardiomyocytes in particular. The purpose of the study was to study the changes in the myocardium under the action of general hypothermia at different levels of structural organization. The object of the study were the hearts of laboratory adult rats. The study involved 20 animals. The longitudinal section shows that the right ventricle is much thinner than the left and its cavity is presented in the form of a crescent. The interventricular septum is thicker than the wall of the right ventricle and goes into its cavity. Results. To establish the shape of the heart and track the dynamic changes at the organ level, we calculated an index showing the ratio of the width of the heart to its length. In 80% of cases, the heart shape of intact rats was conical, the index averaged 55%, only 20% elliptical, the index was more than 65%. We did not observe other forms of heart in the group of intact rats. In the experimental groups, a spherical heart shape appeared. The thickness of the anterior wall of the left ventricle for 10 days from the beginning of the experiment was 3.15±0.11 mm, the side wall 3.1±0.11 mm, the posterior wall 2.45±0.04 mm, interventricular septum 2.95±0.09 mm. In the right ventricle, the thickness of the anterior wall is 1.04±0.03 mm, the posterior wall is 1.36±0.04 mm. On the 30th day from the beginning of the experiment, the thickness of the anterior wall of the left ventricle was 3.21±0.11 mm, the side wall 2.65±0.06 mm, the posterior wall 3.27±0.09 mm, the interventricular septum 3.14±0.13 mm. In the right ventricle, the thickness of the anterior wall is 1.09±0.04 mm, the posterior wall is 1.38±0.03 mm. Conclusions. The increase in heart mass, change in its shape due to changes in the middle third of the heart wall of both the left and right ventricles. The highest rates were in the middle third of the heart (zone "B"): In all layers of the myocardium there is an increase in the diameter of cardiomyocytes, a decrease in the distance between individual cardiomyocytes and their groups. The distance between adjacent cardiomyocytes in the left ventricle is: in the outer layer 1/8 of the diameter of the cardiomyocyte, between groups of cardiomyocytes 1/4 of the diameter of the cardiomyocyt

Peptization of boehmites with different peptization index: An electron microscopy and synchrotron small-angle X-ray scattering study

Boehmite AlOOH is used as a precursor for the preparation of mesoporous gamma-alumina, which is of well-known interest for use as a catalyst support in petroleum refinery. The fabrication of the shaped supports is usually decomposed in several steps: synthesis of boehmite, preparation of a paste by kneading, extrusion of the paste and finally calcination to obtain the alumina phase. Mesoporous alumina is a complex hierarchical porous network, whose growth is influenced by each step of the process, and needs to be clearly understood to optimize the catalytic performances. This paper is focused on the peptization of boehmite, an important step in the fabrication which corresponds to the beginning of the kneading. Peptization is carried out in liquid phase, from two boehmites batches with different abilities to be peptized (peptization index) and with different acid/aluminum ratios. The as-obtained suspensions are characterized by coupling electron microscopy and small-angle X-ray scattering, which bring an accurate description of the samples at their different levels of structural organization. A multi-scale mechanism of peptization is then proposed. Finally, we will discuss the study of the measure of boehmites peptization index, and confirms the textural features which are relevant for the behavior of a boehmite in an acid medium.

On Novelty, Heterochrony and Developmental Constraints in a Complex Morphological Theory of Recapitulation: The Genus Trophon as a Case Study

Darwin proposed natural selection as the main evolutionary mechanism in 1859. However, he did not think that this was the only process by which new species were generated. It was the so-called Modern Synthesis who established natural selection as the only mechanism responsible for evolution. Since then, the evolutionary process is explained by the pair mutation-adaptation: new species are generated by the appearance of new mutations, which in case of allowing new adaptations to the environment, they will be fixed and organisms will survive, therefore resulting in new species. An alternative view to the plasticity promoted by the adaptationist program is to think organisms as truly organized structures, having different levels of structural organization, which would mean that not every form is possible, but only those that correspond to a certain building plan. This would be reflected in the appearance of structural constraints, showing the limits imposed to the organism during its evolutionary development. In this work, I studied the ontogeny and development of three species of the genus Trophon by geometric morphometrics, in order to clarify important concepts in evolutionary developmental biology (Evo-Devo). Integrating theoretical and empirical investigations, I could propose a new conceptual framework for heterochrony in a context of a complex theory of recapitulation. Furthermore, I could detect a developmental constraint in Trophon, which provided an opportunity to reconstruct the concept of constraint and propose a synthesis between heterochrony and constraint that explained evolution as a process fueled by them, that is, as directive and driving force.

Adaptation of epilthic ferns on different levels of structural organization

Adaptive strategies of sporophytes of epilithic ferns are identified on the basis of research studies and literature data. A complex analysis of the photosynthetic apparatus of plants is carried out on different levels of its organization: frond, mesophyll cells, and plastids. The adaptation of sporophytes to the environment is also characterized on different levels of organization. Two morphofunctional (MFTs) and two physiological-functional types (PFTs) of ferns are isolated on the basis of their adaptability to epilithic living. This division reflects the adaptive peculiarities of ferns in certain biomes.

Environmental Photochemistry of Amino Acids, Peptides and Proteins.

Amino acids, peptides and proteins are central building blocks of life and of key importance in the biogeochemistry of aquatic ecosystems. In sunlit surface waters, amino acid-based molecules at different levels of structural organization are susceptible to transformation by both direct photochemical reactions and indirect processes caused by photochemically produced reactive oxygen species (e.g. hydroxyl radical or singlet oxygen). Photochemical transformation processes can thereby affect the availability of these crucial nutrient sources in aquatic ecosystems, inhibit the function of microbial extracellular enzymes, or even promote the degradation of amino acid-based pollutant molecules. In this article, the environmental photochemistry of amino acids, peptides and proteins in aquatic systems is reviewed.

Genistein: A Phytoestrogen with Multifaceted Therapeutic Properties

Countless bioactive constituents obtained from different medicinal plants have long been focused by the researchers of the scientific community and pharmaceutical industry. In recent years, extensive in vitro and in vivo research has been carried out with these biomolecules to develop complementary and alternative medicines. Findings revealed that these molecules may act as promising agents for almost all kinds of pathophysiological states. Further, these novel bioactive compounds are mostly not harmful in dietary doses. In this eclectic review, we highlighted the beneficial role of genistein, an isoflavone available mainly in the legumes particularly in soybean. Genistein is a potent phytoestrogen which binds with both alpha and beta estrogen receptors and regulate the divergent intracellular signaling cascades of estrogen. It also has the potential to competitively inhibit different imperative ATP utilizing enzymes. These properties help genistein in regulating various cellular and biochemical functions at different levels of structural organization in the body. Moreover, it's very low cytotoxicity and abundance in regular aliment compared to other isoflavones makes it a more promising therapeutic option. Emerging evidence from the literature proves the competence of genistein in combating oxidative stress, cancer, diabetes, obesity, inflammation, osteoporosis, neuropathy and some other disorders. This review aims to unravel the assorted underlying mechanisms behind the multivariate properties of this unique aglycone.

Analysis of RNA secondary structure.

RNA has different levels of structural organization. The primary structure is the linear order of the nucleotide monomers, the RNA sequence. During transcription process, the partially synthesized RNA is folded by base-pairing and thermodynamic intramolecular or intermolecular interactions. This results in a dynamic spreading of a secondary structure along the length of the transcribed section of the RNA. The analysis of both primary or secondary structures requires the RNA end-labeling either at its 5' end using a kinase reaction with [gamma-32P]ATP, or at its 3' end using an RNA ligation reaction with [32P]pCp. End-labeled RNAs are then gradually breakdown using hydrolysing chemicals or a variety of enzymes targeting specific RNA sequences and secondary structure. The most commonly used enzymes are RNase A, T1, and V1. The partial digestion of the RNA reveals a mix of truncated RNA fragments of different lengths, called RNA ladder. The products are then separates through a high resolution gel system and subjected to autoradiographic analysis. Each visible fragment is labeled at one end, but comprises an enzyme specific sequence at the other end. Final comparison of the detected RNA ladders reveals a hypothetical model of the secondary RNA structure under assay conditions.

Chemodiversity and Molecular Plasticity: Recognition Processes as Explored by Property Spaces

In the last few years, a need to account for molecular flexibility in drug-design methodologies has emerged, even if the dynamic behavior of molecular properties is seldom made explicit. For a flexible molecule, it is indeed possible to compute different values for a given conformation-dependent property and the ensemble of such values defines a property space that can be used to describe its molecular variability; a most representative case is the lipophilicity space. In this review, a number of applications of lipophilicity space and other property spaces are presented, showing that this concept can be fruitfully exploited: to investigate the constraints exerted by media of different levels of structural organization, to examine processes of molecular recognition and binding at an atomic level, to derive informative descriptors to be included in quantitative structure--activity relationships and to analyze protein simulations extracting the relevant information. Much molecular information is neglected in the descriptors used by medicinal chemists, while the concept of property space can fill this gap by accounting for the often-disregarded dynamic behavior of both small ligands and biomacromolecules. Property space also introduces some innovative concepts such as molecular sensitivity and plasticity, which appear best suited to explore the ability of a molecule to adapt itself to the environment variously modulating its property and conformational profiles. Globally, such concepts can enhance our understanding of biological phenomena providing fruitful descriptors in drug-design and pharmaceutical sciences.

Comparative morphological analysis of peripheral endocrine glands of small mammals inhabiting areas with high levels of radioactivity and exposed to chronic irradiation in model experiments

Comparative study of cellular-tissue reactions in the endocrine organs (thyroid and adrenal glands and ovary) of rodents exposed to radiation under natural conditions (Radium station in the Komi Republic and 30-km zone of Chernobyl NPP) and under experimental conditions modeling chronic exposure is carried out. Evidence is found that low-dose chronic irradiation causes morphological disorders at different levels of structural organization (cellular-tissue, organism, and population levels). The experimental results show that the observed variations in the morphometric parameters of the thyroid and adrenal glands and ovary reflect natural changes in their functional activity (within the physiological limits). These changes are directed at the maintenance of homeostasis under altered conditions and have a compensatory and adaptive character. The effects of low-dose radiation in combination with other agents may be amplified at the level of cellular-tissue reactions. In comparison with the experimental results, natural conditions (high level of radioactivity due to α and β emitters, high natural radionuclides, toxic elements, and extreme climatic factors) induce more pronounced changes, including a significant increase in chromosomal and gene mutations in cells, destructive processes in the organs of the endocrine system, and disorders of reproductive functions.

The morphofunctional approach in paleontology

The principle of actualism is regarded as the major principle in morphofunctional studies of fossil organisms, which is based on comparisons of evolutionary series of both extinct and extant taxa. The objects and specificity of morphofunctional studies in paleontology are discussed. The revelation of relationships between morphological and functional archetypes are considered to be the major task of these studies. The ecosystem approach, constrains on actualistic reconstruction imposed by various morphofunctional modi, hierarchy of functions at different levels of structural organization and at different phylogenetic stages are considered. It is shown that parallel development and the mosaic pattern of characters are accounted for by general morphogenetic mechanisms and heterochronies.

Fibre type‐specific increase in passive muscle tension in spinal cord‐injured subjects with spasticity

Patients with spasticity typically present with an increased muscle tone that is at least partly caused by an exaggerated stretch reflex. However, intrinsic changes in the skeletal muscles, such as altered mechanical properties of the extracellular matrix or the cytoskeleton, have been reported in response to spasticity and could contribute to hypertonia, although the underlying mechanisms are poorly understood. Here we examined the vastus lateralis muscles from spinal cord-injured patients with spasticity (n = 7) for their passive mechanical properties at three different levels of structural organization, in comparison to healthy controls (n = 7). We also assessed spasticity-related alterations in muscle protein expression and muscle ultrastructure. At the whole-muscle level in vivo, we observed increased passive tension (PT) in some spasticity patients particularly at long muscle lengths, unrelated to stretch reflex activation. At the single-fibre level, elevated PT was found in cells expressing fast myosin heavy chain (MyHC) isoforms, especially MyHC-IIx, but not in those expressing slow MyHC. Type IIx fibres were present in higher than normal proportions in spastic muscles, whereas type I fibres were proportionately reduced. At the level of the isolated myofibril, however, there were no differences in PT between patients and controls. The molecular size of the giant protein titin, a main contributor to PT, was unchanged in spasticity, as was the titin : MyHC ratio and the relative desmin content. Electron microscopy revealed extensive ultrastructural changes in spastic muscles, especially expanded connective tissue, but also decreased mitochondrial volume fraction and appearance of intracellular amorphous material. Results strongly suggest that the global passive muscle stiffening in spasticity patients is caused to some degree by elevated PT of the skeletal muscles themselves. We conclude that this increased PT component arises not only from extracellular matrix remodelling, but also from structural and functional adaptations inside the muscle cells, which alter their passive mechanical properties in response to spasticity in a fibre type-dependent manner.

Conformational analysis of xylan chains

The present study provides a theoretical description of the different levels of structural organization that characterize the xylan polysaccharide in its native and hydrophobic lauroyl esterified forms. The goal of this study was to ascertain the role played by the hydroxyl or lauroyl side groups on the conformational flexibility of the xylan chain backbone. The results reported provide a detailed description of the low-energy conformers of the dimer segments, a complete characterization of the helical structures, an insight into the disordered state of the polysaccharide chains and an estimation of the cohesion of the amorphous solids. Esterification of xylan hydroxyl groups by lauric acid has a large effect on the conformational properties of the glycosidic bonds linking two repeat units. Both the location and the relative energies of the low energy areas of the potential energy surfaces strongly differ: extended and coiled conformations are preferred for the native and hydrophobic forms, respectively. Consequently, the predicted unperturbed polymer chain extension strongly depends on the structure, predicted L p of the native xylan of 35 Å compares favourably well with the experimental ones, this characteristic dramatically decreases to 9 Å for the hydrophobically modified chain. Curiously, only extended 2 1 and left-handed 3 1 helical structures are calculated stable for both polymers. The estimated cohesive parameters of amorphous bulks reveal that inter-chain interactions are stronger for the xylan chain than that for modified one, the former being stabilized by hydrogen bonds whereas hydrophobic interactions play a determinant role for the latter.

Tissue and Intracellular Reorganization of Rat Liver during Total Body Hypothermia

We studied tissue and intracellular reorganization of the liver during total body hypothermia and evaluated regeneration strategies at different levels of structural organization. Hypothermia results in morphofunctional changes in the liver (degeneration, lysis, necrobiosis, and focal necrosis of hepatocytes developing against the background of disorders in blood and lymph circulation). Decreased sinusoid/hepatocyte volume ratio is the key factor in tissue reorganization of the liver. Intracellular reorganization of hepatocytes is characterized by dysproportional changes in the volume and surface densities of the main cytoplasmic organelles involved in biosynthesis and energy production.

An intranuclear frame for chromatin compartmentalization and higher-order folding.

Recent ultrastructural, immunoelectron, and confocal microscopy observations done in our laboratory [Barboro et al. [2002] Exp. Cell. Res. 279:202-218] have confirmed that lamins and the nuclear mitotic apparatus protein (NuMA) are localized inside the interphase nucleus in a polymerized form. This provided evidence of the existence of a RNA stabilized lamin/NuMA frame, consisting of a web of thin ( approximately 3 and approximately 5 nm) lamin filaments to which NuMA is anchored mainly in the form of discrete islands, which might correspond to the minilattices described by Harborth et al. [1999] (EMBO. J. 18:1689-1700). In this article we propose that this scaffold is involved in the compartmentalization of both chromatin and functional domains and further determines the higher-order nuclear organization. This hypothesis is strongly supported by the scrutiny of different structural transitions which occur inside the nucleus, such as chromatin displacement and rearrangements, the collapse of the internal nuclear matrix after RNA digestion and the disruption of chromosome territories induced by RNase A and high salt treatment. All of these destructive events directly depend on the loss of the stabilizing effect exerted on the different levels of structural organization by the interaction of RNA with lamins and/or NuMA. Therefore, the integrity of nuclear RNA must be safeguarded as far as possible to isolate the matrix in the native form. This material will allow for the first time the unambiguous ultrastructural localization inside the INM of the components of the functional domains, so opening new avenues of investigation on the mechanisms of gene expression in eukaryotes.