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Peri-implant bone tissue regeneration involves complex processes that are not yet fully understood at the cellular and molecular levels, leaving significant gaps in our knowledge that require further investigation. Aim. The study aimed to compare peri-implant osteogenesis on titanium femoral implants with alumina composite coatings applied by different methods to conventional titanium implants in an animal model. Materials and methods. Implants underwent sandblasting with silicon carbide, plasma torch treatment, and coating with titanium, corundum, sprayed titanium wire, or hydroxyapatite, resulting in seven different surfaces. 105 female Wistar rats received implants in their right femurs and were divided into 7 groups based on implant type and exposure duration (1, 2, or 4 weeks). Implant fragments were analyzed using scanning electron microscopy and energy dispersive X-ray spectroscopy to quantify chemical elements. Ratios of carbon to nitrogen and calcium to phosphorus were calculated. Data were analyzed using the U-Mann–Whitney test, with р < 0.05 as a significant value. Results. The energy dispersive X-spectrometry results confirmed morphological analysis findings by quantitatively and qualitatively assessing implants surface chemical composition. The key elements were evaluated, relevant for identifying bone tissue components like collagen (C and N) and hydroxyapatite (Ca and P), as well as implant coatings (Ti, Al, Ca, and P). Carbon and phosphorus showed fluctuations over time, with notable differences among groups. Aluminum appeared stable in some groups but varied in others. Calcium levels remained low initially and increased steadily in hydroxyapatite coated implants. Titanium levels were high initially, decreasing slightly over time. Morphological analysis correlated with surface roughness measurements. Notably, fibrin, collagen, and bone tissue presence varied among groups over time, with some groups showing significant mineralized bone tissue accumulation. After four weeks, blood clots persisted in some groups, while others exhibited bone tissue remodeling with the presence of osteoblasts and osteoclasts. Alumina-based coatings showed signs of degradation, with alumina cement scales found among macrophages and fibers. Conclusions. Our study found that stable bone implants outperform alumina-composite coatings in long-term osseointegration due to mechanical stability. Although ceramic composites initially enhance osteoinductive properties, better attachment to titanium substrates is needed. [ABSTRACT FROM AUTHOR]

The using of explosive substances and devices can lead to brain injuries, the diagnosis of which requires the determination of primary biomarkers. Therefore, the aim was to establish and study histopathological and ultrastructural changes in the rats brain after exposure to an air blast wave. The study was carried out on 18 male Wistar rats, which were randomly divided into two groups: sham (n=9) and experimental (n=9). The animals of the experimental group were anesthetized with halothane and gently fixed in a horizontal position on the abdomen with the front part of the rat's muzzle at a distance of 5 cm from the device opening and subjected to an excess pressure of 26-36 kPa. Animals of both groups were decapitated, brains were removed, fixed, histopathological and ultrastructural analyzes were conducted using standard methods. Intergroup differences were assessed by MannWhitney U-test. Light microscopy revealed primary lesions in the form of small focal, multifocal hemorrhages, cerebral vessel ruptures and microscopic ruptures of the brain substance. In almost all brain samples, there is a significant saturation of the venous vessels with the presence of erythrocyte stasis. Violation of the blood-brain barrier, the presence of edema of the perivascular space, and petechial hemorrhages in the neuropil were registered ultrastructurally. Based on the study results, a morphological algorithm for assessing primary histostructural intracranial brain injuries and their consequences after exposure to an air shock wave was proposed. The injuries were found to be caused by the direct traumatic effect of the air shock wave. In the acute post-traumatic period, histopathological and ultrastructural changes in the brain can manifest as changes in neurons and in the blood-brain barrier and be accompanied by perivascular multifocal small-focal hemorrhages, neuropil ruptures, edema of pericellular and perivascular spaces, which together can be considered as biomarkers of primary traumatic changes after exposure to an air shock wave. [ABSTRACT FROM AUTHOR]

Serotonin is not only a neurotransmitter but also an important humoral regulator of various physiological processes outside the central nervous system. In the last decade, the concept of local serotonergic systems in peripheral organs, where serotonin realizes its effects via autocrine/paracrine mechanisms, has been under development. Such local systems have already been described in the pancreas, thymus, mammary gland, and bone marrow. We consider that a similar local serotonergic system is also characteristic of the adrenal glands. These paired organs are a key component of the mammalian endocrine system, providing a complex physiological response to stress. The adrenal glands consist of two parts distinct in origin and function—the cortex and medulla—while serotonin plays an important role in regulating hormone secretion in both of these structures. This review is aimed at analyzing the structure of the local serotonergic system in the adrenal gland as well as its role both in the regulation of adrenal functions in adult animals and in the formation of adrenals in embryogenesis. Analysis of the available data suggests that local serotonergic systems makes an organ susceptible to fluctuations in the level of serotonin circulating in the blood at all stages of ontogenesis. Thus, local sensitivity to serotonin provides the possibility of systemic humoral coordination of the development and functioning of the adrenal glands and other peripheral organs. From this perspective, the importance of local serotoninergic systems for developmental biology and medicine becomes clear. [ABSTRACT FROM AUTHOR]

The effect of mild prenatal stress in mice, leading to an increase in the placental serotonin level, on the formation of adaptive behavior in male offspring at the age of 35 days was studied. It was shown that, in BalbC mice, daily immobilization for 1 h during the period from 11 to 14 days of pregnancy led to an increase in placental and fetal serotonin levels on the 15th day of prenatal development. According to "resident–intruder" behavioral test, the prenatally stressed mice showed more reactive behavior in adulthood and low tendency to defend their territory. Thus, placental serotonin, formed under the stress condition, may act as a mediator between the environment and the fetuses and determine the adaptive behavior of offspring. [ABSTRACT FROM AUTHOR]

The extensive information accumulated over the past few decades on the important role of cerebrospinal fluid in many physiological processes in norm and pathology allowed the authors of the paper to express a hypothesis that the brain has its own endocrine system, which is represented by (a) brain neurons secreting neurohormones into the ventricles, (b) cerebrospinal fluid, a body fluid that ensures the delivery of neurohormones to the brain target regions, and (c) neurons of the periventricular region of the brain, targets for neurohormones contained in the cerebrospinal fluid. According to this hypothesis, the functional significance of the endocrine system of the brain in ontogenesis moves from the regulation of the neuron and brain development in the perinatal period to participation in volume neurotransmission in adulthood. This study is aimed at testing this hypothesis. Thus, in neonatal (fifth day of life) and adult (30th day of life) rats, it was shown that substances contained in the cerebrospinal fluid are involved in the regulation of monoamine secretion by brain neurons into the cerebrospinal fluid. These data were obtained by perfusion of cerebral ventricles with artificial cerebrospinal fluid with an increased content of K+. However, stimulation of the secretion of monoamines was not found in all animals within each age group, which is explained by the individual and age-related characteristics of the cerebrospinal fluid-brain barrier permeability. Indeed, perfusion of brain slices in the incubation medium with an increased content of K+ (in the absence of a cerebrospinal fluid-brain barrier) invariably led to the stimulation of monoamine secretion in all animals in both age groups. The second proof of the validity of our hypothesis was the demonstration of the uptake of substances from the cerebrospinal fluid into monoaminergic neurons of the brain, which are considered as potential targets for the endocrine factors of the cerebrospinal fluid. Evidence of this was obtained with the introduction into the cerebral ventricles of 4-[4-(dimethylamino)styryl]-N-methylpyridinium iodide, which has a high affinity for monoamine transporters. After intraventricular administration, this marker was incorporated into neurons in the periventricular region of the brain. Thus, evidence has been obtained that the substances contained in the cerebrospinal fluid in neonatal and adult rats are involved in the regulation of the secretion of monoamines in the cerebral ventricles, and monoamines contained in the cerebrospinal fluid enter the brain and are captured by potential target neurons. [ABSTRACT FROM AUTHOR]

Utilization of functional-protective coatings for implants based on corundum ceramics seems promising from the point of view of stability, bioinertness, and low cost. In order to study the histological criteria for evaluating the osteoinductive properties of functional protective coatings, 6 types of coatings were studied on an experimental animal model: 90 Wistar rats were implanted with 6 test types of implants with various combinations of surface treatment (sand-blasting, surface treatment with a plasma torch with simultaneous application of aluminum oxide, powdered titanium, etc.) with an exposure of 1, 2 and 4 weeks. After euthanasia, a histological examination of decalcified bone with MassonGoldner trichrome staining and TRAP-histochemical reaction for osteoclasts was performed. The obtained results demonstrated significantly higher osteoinductive properties of functional protective coatings with a more pronounced roughness (Ra>10 μm) compared to an untreated titanium surface after 2 (p<0.01) and 4 (p<0.05) weeks of implantation. The corundum ceramic coating prevented the formation of implant wear particles, hence contributed to the stabilization of the newly formed bone. Therefore, the use of functional protective implant coatings based on corundum ceramics can increase the survival rate of conventional titanium implants, since the combination of factors such as surface roughness, mechanical stability, and chemical inertness of coatings with corundum ceramics provides better osteoinductive properties of implant materials. [ABSTRACT FROM AUTHOR]

The problem of thermoelasticity for transversely isotropic plates acted upon by concentrated heat sources is solved. The {1, 2}-order equations of thermoelasticity that incorporate the transverse shear and normal stresses are used. A bending heat source with symmetric heat transfer is considered. The dependence of thermal stress components on the thermal and thermomechanical parameters of transversely isotropic plates is studied [ABSTRACT FROM AUTHOR]

We studied the effect of acute (single immobilization for 1 h) and repeated (daily immobilization for 1 min, 5 days) moderate stress on disturbances in contractility of mesenteric lymphatic vessels in rats with experimental peritonitis. Acute stress was shown to potentiate, while moderate repeated stress attenuate the effect of inflammatory stimulus. It can be hypothesized that moderate repeated stress improves adaptive capacities of the organism, which manifests in reduction or prevention of dysfunction in contractile activity of lymphatic vessels. [ABSTRACT FROM AUTHOR]