Comparative characteristics of changes in subchondral bone of rats after antenatal glucocorticoid administration and modeling of osteoporosis

Background. Osteoporosis is a progressive systemic bone disease that results in decreased bone mineral density and, as a result, increases the risk of bone fractures. Changes that occur in the subchondral bone in osteoporosis or because of hormones can cause degenerative changes in the articular cartilage that underlie osteoarthritis. Objective. The aim of the study was to identify and compare morphological changes that occur in the subchondral bone in experimental simulations of osteoporosis and in adult rats that were born from females that were exposed to glucocorticoid solution administration in the 3rd trimester of pregnancy. Methods. Tibias of 26 white mature laboratory rats were studied. In serial sections, the relative areas occupied by bone trabeculae and lacunae were calculated. Results. The relative area involving the bone trabeculae (23,2 ± 3,70%) statistically significantly decreased at 21 day in the group of animals that undergone a simulation of osteoporosis in comparison with the control group. Similar changes are observed in the group of experimental animals that were born from females that were exposed to glucocorticoid solution administration in the 3rd trimester of pregnancy. Conclusion. Thus, the results of the study demonstrate the similarity of morphological changes occurring in the subchondral bone in rats that undergone a simulation of osteoporosis and rats that were born from females that were exposed to glucocorticoid solution administration in the 3rd trimester of pregnancy.

Analysis of the Dynamics of Marine Structures and Species with Criterial Mathematical Models

The influence of the area of artificial substrates (collectors) on the biological parameters of populations of mussels (Mytilus galloprovincialis Lamarck) during their cultivation in the Black Sea has been investigated. For growing mollusks, four types of collectors were used, with different relative areas (ω), i.e., with different ratios of the substrate area (S) per unit length of the collector (L), which were 0.09, 0.21, 0.34, and 0.55. It was found that, during a 1.5-year cultivation, the density (N, ind./m) and biomass (B, kg/m) change and reach a certain stationary state, determined by the relative area of the substrate. It was shown that, on collectors with a higher value of ω, there was a decrease in the average length (L, mm) and weight (W, g) of the mollusk yield. The Boysen–Jensen method was used to calculate the total production of mollusks (P), elimination (E), and specific production (P/B coefficient) for each type of reservoir, and it was shown that P increased with an increase in the substrate area, while E and P/B coefficients decreased. Based on the analysis of the obtained results, it was concluded that during the cultivation of mussels these parameters are regulated by density-dependent population factors (intraspecific competition) for space (substrate) and food.

Cambio de área glaciar en el volcán Maipo (Andes Centrales), una aproximación morfométrica: 4 décadas de registros satelitales

Current climatic conditions in Central Andes (CA) (31-36 °S) have triggered the reduction of glacier area. Although CA are geographically circumscribed to an area under the same macroclimatic domain, their rugged topography creates several topoclimates as response to the effects of elevation, slope and aspect (morphometric factors). This study explores the impact of morphometric factors on the evolution of the glacial surface located above of Maipo volcano (34°09'50''S; 69°49'53''W). Through the use of 11 LANDSAT images (MSS, TM and OLI), the spatio-temporal evolution (period 1976-2020) of the glacier area was reconstructed. On this period, glacier area was reduced by 6 ± 0.5 km2 (-0.14 ± 0.01 km2a-1), equal to 63 % of 1976 glacial area (9.6 ± 0.5 km2). Fifty percent of the reduction occurred between 3,900 and 4,000 m elevation, with absolute losses towards lower elevations. In addition, it was detected that for every 100 m of ascent the relative area loss rate decreased 0.1 %a-1 (R2 = 0.81; p-value

Effects of gamma radiation and post-operative cisplatin injection on the incorporation of bone allografts in rats

Background. The reconstruction of long bone defects that occur after resection of tumors is a problem that requires constant study. Bone allografts are often used in this scenario. Unfortunately, while they are prepared, allografts partially lose their strength and osteoinductive properties; their survivability in oncological patients is only 40% after 10 years. This is why the search for superior allograft treatment methods and the study of allograft remodeling and incorporation in oncological patients, whose state has been affected by radiation or chemotherapy, is an area of interest. Purpose – study the structure of bone tissue in the distal metaphysis of a rat’s femur after bone allograft implantation (sterilized using gamma radiation or antibiotic saturation) and post-operative intraperitoneal cisplatin injection. Materials and Methods. Experiments were performed on 20 male white rats aged 5–6 months at the beginning of the experiment and weighed 365.8 ± 6.4g. All rats underwent a surgery that created a defect in the distal metaphysis of the femur which was filled with a bone allograft treated with gamma radiation (Control-1 and Experimental-1 groups) or saturated with an antibiotic (Control-2 and Experimental-2 groups). 14 days after allograft implantation, animals from the control groups received an intraperitoneal injection of 2.0–2.4 ml of 0.9% NaCl, while animals from the experimental groups received 2.5mg/kg of cisplatin. Histological analysis and histomorphometry were completed 30 days after the surgery. Results. 30 days after the operation, the smallest relative area of bone tissue (11.79%) was observed in rats from the Experimental-1 group, with gamma radiation treated allografts and post-operative intraperitoneal cisplatin injections. A somewhat higher value was found in the Experimental-2 group (antibiotic saturation + cisplatin) – 31.64%. In the control groups, (intraperitoneal injection 0.9% NaCl), the relative area of bone tissue was 16.7% (Control-1, gamma radiation treatment) and 58.09% (Control-2, antibiotic saturation). The relative area of fibrous tissue was the largest in the Experimental-1 group – 31.55% and the smallest in the Control-2 group – 12.79%. Conclusions. Allograft remodeling occurs along with the formation of bone and fibrous tissue when allografts are used to fill defects in the distal femoral metaphysis of rats, However, the relative percentages of those tissues depend on the allograft sterilization method and the use of cytostatic agents. The largest relative percentage of bone tissue (58.09%) was obtained using an allograft saturated with antibiotics and without the administration of cisplatin. The smallest (11.79%), on the other hand, occurred in gamma radiation treated allografts with cisplatin injected intraperitoneally after the operation

Eardrum perforation treatment blood plasma enriched with platelet growth factors

Introduction. The problem of the development of acute post-traumatic otitis media has not lost its relevance. Long-term preservation of the defect of the tympanic membrane contributes to the development of chronic inflammation in the middle ear and a deterioration in the quality of life of patients.Objective. To study the effect of blood plasma enriched with platelet growth factors on the regeneration of the tympanic membrane tissues in patients with acute post-traumatic perforation.Materials and methods. Patients with acute post-traumatic perforation of the tympanic membrane were divided into the main (24 people) and control (19 people) groups. Patients of the main group in the area of perforation of the tympanic membrane were injected once by application with a clot of autoplasma, enriched with platelet growth factors. The control group patients underwent dynamic observation of the processes of natural regeneration of the tympanic membrane tissues. On the 5, 10 and 15th days, the tissue regeneration of the tympanic membranes was assessed subjectively (patient complaints, audiometry) and objectively (otoscopy with the calculation of the dynamics of the relative perforation area, otoacoustic emission).Results. A single application of blood plasma enriched with platelet growth factors to the perforation area was significantly more often accompanied by closure of the tympanic membrane perforation (p ≤ 0.01) and a decrease in the average relative area of the tympanic membrane perforation on days 10 and 15 of the study (p ≤ 0.01). The dynamics of the average relative area of the tympanic membrane perforation reflected a high rate of closure of the tympanic membrane defect in the main group. Better healing of the tympanic membrane in patients of the main group was accompanied by an improvement in the auditory function of the affected ear. The quality of hearing was, on average, significantly better in the patients of the main group than in the patients of the control group, both on the 10th and 15th days of observation (p ≤ 0.01).Conclusion. Clinical use of blood plasma enriched with platelet growth factors has a beneficial effect on the rate, intensity of closure of the tympanic membrane perforation and hearing.

Ensuring a Stable Relative Area of Burnishing of Partially Regular Microrelief Formed on End Surfaces of Rotary Bodies

The scheme of arrangement of grooves of partially regular microrelief of type II shifted by 0.5 angular pitch is considered. Such grooves are formed by vibration on end faces of rotary bodies. An analytical dependence was obtained to determine the relative area of a partially regular microrelief depending on the geometric parameters of V-shaped grooves. The parameters of the grooves of a partially regular microrelief formed at different distances from the center of rotation are determined, at which the value of the relative area of the partially regular microrelief formed on the treated surface will be stable.

P–414 HLA-G expression as a new prognostic marker of successful implantation

Study question Is the low HLA-G expression a determinant of early reproductive loss? Summary answer Low expression of HLA-G is associated with pregnancy complications and can be one of the reasons of spontaneous abortion (such as RPL). What is known already The dysregulated maternal immune responses to invading embryos may play role in RIF, RPL, and second- and third-trimester obstetrical conditions. HLA-G is a molecule that was first known to confer protection to the fetus from destruction by the immune system of its mother, thus critically contributing to fetal–maternal tolerance due to inducing displacement of pro-inflammatory to Th1 cell-mediated response of Th2, has a positive influence on the process of implantation. HLA-G is mainly restricted to the fetal–maternal interface on the extravillous cytotrophoblast, to placenta, amnion. Study design, size, duration It was a prospective complex cohort study from 2016–2020 years with pathomorphological investigations. The purpose of this study is to investigate the HLA-G and KIR2DL4 expression in chorionic villous among 3 groups (study included 118 cases of abortion material): group 1 – 36 cases after missed abortion with normal karyotype, group 2 – 36 cases after missed abortion with polyploidy and group 3 – 46 cases after induced abortion group (normal pregnancy). Participants/materials, setting, methods Criteria of inclusion: abortive material from 3 groups of women with missed or after induced abortion; 6–12 weeks, singleton pregnancy, cytogenetic of chorionic villous was obligatorily - normal fetal karyotype and polyploidy of fetus. Pathomorophological investigation included H&E stain, IHC and confocal laser scanning microscopy. Immunohistochemical examination included quantitative and qualitative assessment of the expression of Anti-HLA-G (mouse monoclonal) in an extra villous trophoblast and Anti-KIR2DL1+KIR2DL3 + KIR2DL4 + KIR2DS4 (rabbit polyclonal) in chorionic villi. Main results and the role of chance The immunohistochemical study showed homogenous distribution HLA-G expression in extravillous trophoblast cells (EVT) and KIR2DL4 expression in chorion villous both in missed abortion groups and in induced abortion group. HLA-G expression average relative area in 1 and 2 groups was not statistically different (in 1 group with normal karyotype 33,9±3,5 and in 2 group 38,6±2,8). But the expression of HLA-G in 3 group was strictly higher (55,6 ±2,4). The average relative area of KIR2DL4 receptor wasn’t statistically different among 3 groups. However, the histological picture both missed abortion groups (for the genetic\immunological reasons for rejection) is the only one - this is a missed abortion of an early terms of gestation. In a histological study of missed abortion, as our study shows, the histological picture is similar in 1 and 2 groups. Thus, in 1 group with a normal karyotype of the fetus (before conducting the chorion cytogenetic study in the genetics laboratory) in 59.2% the histological examination determined a picture of an impaired early pregnancy with signs of trophoblast chromosomal pathology. Thus, without a cytogenetic study of the chorion, it is impossible to clearly determine whether the chromosomal pathology of the fetus is the cause of missed abortion. Limitations, reasons for caution There is no limitations, reasons for caution. Wider implications of the findings: Thus, HLA-G molecule has a leading role in the onset and successful prolongation of pregnancy, implantation, placentation and fetal development. Trial registration number 98–2019

SHIPS WITH SMALL WATER-PLANE AREA: THE MAIN INFORMATION

Ships with small water-plane area (below “SWA ships”) have very special shape of hulls. It is the reason of characteristic specificity of such ships. SWA ships usually are multi-hull ones. And as all multi-hulls, SWA ships differ from the comparable mono-hulls by bigger deck area relative the displacement and by simple ensuring of stability. There are some architectural types of SWA ships. Their differences are shown by the article. Relative area of deck and initial transverse stability of SWA ships are compared. Statistical data on performance: twin-hull SWA versus catamarans. Common specificity of and . The main external loads. Special method of designing. Main disadvantages. Conclusions, recommendation.

Subchondral Bone Relative Area and Density in Human Osteoarthritic Femoral Heads Assessed with Micro-CT before and after Mechanical Embedding of the Innovative Multi-Spiked Connecting Scaffold for Resurfacing THA Endoprostheses: A Pilot Study

The multi-spiked connecting scaffold (MSC-Scaffold) prototype is the essential innovation in the fixation of components of resurfacing total hip arthroplasty (THRA) endoprostheses in the subchondral trabecular bone. We conducted the computed micro-tomography (micro-CT) assessment of the subchondral trabecular bone microarchitecture before and after the MSC-Scaffold embedding in femoral heads removed during long-stem endoprosthesis total hip arthroplasty (THA) of different bone densities from 4 patients with hip osteoarthritis (OA). The embedding of the MSC-Scaffold in subchondral trabecular bone causes the change in its relative area (BA/TA, bone area/total area ratio) ranged from 18.2% to 24.7% (translating to the calculated density ρB relative change 11.1–14.4%, and the compressive strength S relative change 75.3–122.7%) regardless of its initial density (before the MSC-Scaffold embedding). The densification of the trabecular microarchitecture of subchondral trabecular bone due to the MSC-Scaffold initial embedding gradually decreases with the increasing distance from the apexes of the MSC-Scaffold’s spikes while the spatial extent of this subchondral trabecular bone densification ranged from 1.5 to 2.5 mm (which is about half the height of the MSC-Scaffold’s spikes). It may be suggested, despite the limited number of examined femoral heads, that: (1) the magnitude of the effect of the MSC-Scaffold embedding on subchondral trabecular bone densification may be a factor contributing to the maintenance of the MSC-Scaffold also for decreased initial bone density values, (2) the deeper this effect of the subchondral trabecular bone densification, the better strength of subchondral trabecular bone, and as consequence, the better post-operative embedding of the MSC-Scaffold in the bone should be expected.