Bone Elements Research Articles

Symmetry breaking and effects of nutrient walkway in time-dependent bone remodeling incorporating poroelasticity

Bone is an extraordinary biological material that continuously adapts its hierarchical microstructure to respond to static and dynamic loads for offering optimal mechanical features, in terms of stiffness and toughness, across different scales, from the sub-microscopic constituents within osteons—where the cyclic activity of osteoblasts, osteoclasts, and osteocytes redesigns shape and percentage of mineral crystals and collagen fibers—up to the macroscopic level, with growth and remodeling processes that modify the architecture of both compact and porous bone districts. Despite the intrinsic complexity of the bone mechanobiology, involving coupling phenomena of micro-damage, nutrients supply driven by fluid flowing throughout hierarchical networks, and cells turnover, successful models and numerical algorithms have been presented in the literature to predict, at the macroscale, how bone remodels under mechanical stimuli, a fundamental issue in many medical applications such as optimization of femur prostheses and diagnosis of the risk fracture. Within this framework, one of the most classical strategies employed in the studies is the so-called Stanford’s law, which allows uploading the effect of the time-dependent load-induced stress stimulus into a biomechanical model to guess the bone structure evolution. In the present work, we generalize this approach by introducing the bone poroelasticity, thus incorporating in the model the role of the fluid content that, by driving nutrients and contributing to the removal of wastes of bone tissue cells, synergistically interacts with the classical stress fields to change homeostasis states, local saturation conditions, and reorients the bone density rate, in this way affecting growth and remodeling. Through two paradigmatic example applications, i.e. a cylindrical slice with internal prescribed displacements idealizing a tract of femoral diaphysis pushed out by the pressure exerted by a femur prosthesis and a bone element in a form of a bent beam, it is highlighted that the present model is capable to catch more realistically both the transition between spongy and cortical regions and the expected non-symmetrical evolution of bone tissue density in the medium–long term, unpredictable with the standard approach. A real study case of a femur is also considered at the end in order to show the effectiveness of the proposed remodeling algorithm.

Effect of Copper and Selenium Supplementation on the Level of Elements in Rats' Femurs under Neoplastic Conditions.

A study was conducted to determine the effect of long-term supplementation with selenium and copper, administered at twice the level used in the standard diet of rats, on the content of selected elements in the femoral bones of healthy rats and rats with implanted LNCaP cancer cells. After an adaptation period, the animals were randomly divided into two experimental groups. The rats in the experimental group were implanted with prostate cancer cells. The rats in the control group were kept in the same conditions as those in the experimental group and fed the same diet, but without implanted cancer cells. The cancer cells (LNCaP) were intraperitoneally implanted in the amount of 1 × 106 (in PBS 0.4 mL) at the age of 90 days. The content of elements in the samples was determined by a quadrupole mass spectrometer with inductively coupled plasma ionization (ICP-MS). In the femoral bones of rats with implanted LNCaP cells, in the case of the standard diet and the copper-enriched diet, there was a marked decreasing trend in the content of the analysed elements relative to the control rats. This may indicate slow osteolysis taking place in the bone tissue. Contrasting results were obtained for the diet enriched with selenium; there was no significant reduction in the level of these elements, and there was even an increase in the concentrations of Fe and K in the bones of rats with implanted LNCaP cells. Particularly, numerous changes in the mineral composition of the bones were generated by enriching the diet with copper. The elements that most often underwent changes (losses) in the bones were cobalt, iron, manganese and molybdenum. The changes observed, most likely induced by the implantation of LNCaP cells, may indicate a disturbance of mineral homeostasis.

Nail Mineral Composition Changes Do Not Reflect Bone Mineral Changes Caused by Boron Supplementation.

Nails have been found to be a non-invasive and readily available tissue whose mineral content can change because of a change in dietary mineral intake. Thus, this study was undertaken to determine whether boron (B) supplementation would change the concentrations of some mineral elements in nails and whether these changes correlated with changes induced in bone. Female New Zealand White rabbits (aged 8months, 2-2.5kg weight) were fed a grain-based, high-energy diet containing 3.88mg B/kg. The rabbits were divided into four treatment groups: controls receiving no supplemental B (N: 7; C) and three groups supplemented with 30mg B/L in drinking water as borax decahydrate (Na2B4O7∙10H2O, N: 10; BD), borax anhydrous (Na2B4O7, N: 7; Bah), and boric acid (H3BO3, N: 7; BA). Boron, calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), phosphorus (P), potassium (K), sodium (Na), sulfur (S), and zinc (Zn) concentrations in nails were determined by inductively coupled plasma atomic emission spectroscopy. Parametric and non-parametric multiple group comparisons and post hoc tests were performed and whether a correlation between nail and tibia and femur mineral elements concentrations were determined. A p-value of < 0.05 was considered statistically significant. Boron was not detectable in control nails but was found in the nails of the three B supplemented groups. Boron supplementation markedly increased the Ca concentration in nails with the effect greatest in the BA and BD groups. The P and Mg concentrations also were increased by B supplementation with the effect most marked in the BA group. In contrast, B supplementation decreased the Na concentration with the effect most noticeable in the BD and Bah groups. The Zn concentration in nails was not affected by BA and BD supplementation but was decreased by Bah supplementation. Boron supplementation did not significantly affect the concentrations of Cu, Fe, Mo, K, and S in nails. No meaningful significant correlations were found between nail mineral elements and tibia and femur mineral elements found previously. Nails can be an indicator of the response to boron supplementation but are not useful to indicate changes in mineral elements in bone in response to B supplementation.

Angiogenesis, Osseointegration, and Antibacterial Applications of Polyelectrolyte Multilayer Coatings Incorporated With Silver/Strontium Containing Mesoporous Bioactive Glass on 316L Stainless Steel.

The main causes for failure in implant surgery are prolonged exposure of implants or wound and tissue ischemia. Bacterial infection caused by the surrounding medical environment and equipment is also a major risk factor. The medical risk would be greatly reduced if we could develop an implant coating to guide tissue growth and promote antibacterial activity. Mesoporous bioactive glasses are mainly silicates with good osteoinductivity and have been used in medical dentistry and orthopedics for several decades. Strontium ions and silver ions could plausibly be incorporated into bioactive glass to achieve the required function. Strontium ions are trace elements in human bone that have been proposed to promote osseointegration and angiogenesis. Silver ions can cause bacterial apoptosis through surface charge imbalance after bonding to the cell membrane. In this study, functional polyelectrolyte multilayer (PEM) coatings were adhered to 316L stainless steel (SS) by spin coating. The multilayer film was composed of biocompatible and biodegradable collagen as a positively charged layer, γ-polyglutamic acid (γ-PGA) as a negatively charged layer. Chitosan was incorporated to the 11th positively charged layer as a stabilizing barrier. Spray pyrolysis prepared mesoporous bioactive glass incorporated with silver and strontium (AgSrMBG) was added to each negatively charged layer. The PEM/AgSrMBG coating was well hydrophilic with a contact angle of 37.09°, hardness of 0.29 ± 0.09 GPa, Young’s modulus of 5.35 ± 1.55 GPa, and roughness of 374.78 ± 22.27 nm, as observed through nano-indention and white light interferometry. The coating’s antibacterial activity was sustained for 1 month through the inhibition zone test, and was biocompatible with rat bone marrow mesenchymal stem cells (rBMSCs) and human umbilical vein endothelial cells (HUVECs), as observed in the MTT assay. There was more hydroxyapatite precipitation on the PEM/AgSrMBG surface after being soaked in simulated body fluid (SBF), as observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In both in vitro and in vivo tests, the PEM/AgSrMBG coating promoted angiogenesis, osseointegration, and antibacterial activity due to the sustained release of silver and strontium ions.

Prediction and Verification of Epimedium Flavonoids With Different Glycosylation Numbers in Reversing Glucocorticoid-Induced Bone Formation Inhibition by Molecular Docking and Zebrafish

Glucocorticoids have been detected in environmental waters, and their biological potency has raised concerns on their impact on aquatic vertebrates especially fish. Numerous researches showed that the continuous and direct contact of aquatic vertebrates with glucocorticoid contaminants in environmental water will cause bone formation inhibition. The aim of this study is to predict and verify the effect of icaritin (IT), icariin (ICA), and baohuside-I (BHG-I) in reversing glucocorticoid-induced bone formation inhibition (GIBFI) by molecular docking and zebrafish model. We contrasted their activity in reversing GIBFI from their affinity to bone metabolism proteins (OPG, RANKL, BMP-2, BMP-4, Runx-2) by molecular docking. Subsequently, zebrafish model was adopted to evaluate their reverse effects on GIBFI. Alizarin red staining coupled with image quantification were performed to evaluate the effects of ICA, IT, and BHG-I on skeleton stained area (SSA) and cumulative optical density (COD). Inductively coupled plasma-mass spectrometry was applied to determine the contents of bone mineral elements (CBME, Mg, K, Ca, Fe, Zn) in zebrafish bones. Docking results showed the receptors (BMP-2, BMP-4, and Runx2) all combined well to ICA, while BHG-I bound well to OPG, the affinity between IT and the above targets were the weakest. Fortunately, IT, ICA, and BHG-I significantly increased the SSA, COD, and the contents of Ca compared with the model group (p &amp;lt; 0.05) in the order of IT&amp;gt;ICA&amp;gt;BHG-I. In conclusion, the glycosyl groups increased the H-bond affinity between flavonoids and target sites, which weakened bone formation. IT, BHG-I, and ICA all alleviated GIBFI, but their intensity order was IT&amp;gt;ICA&amp;gt;BHG-I.

MATHEMATICAL MODELING OF THE STRESS-STRAIN RELATIONS OF THE FOOT ELEMENTS IN THE CONDITIONS OF LATERAL MALLEOLUS HYPOPLASIA

One of the most common complications of long-term talocrural joint (TCJ) injury is the development of chronic instability. Among the risk factors for its occurrence - congenital or acquired shortening (hypoplasia) of the lateral malleolus of varying degrees. Objective. Determine the effect of lateral malleolus hypoplasia on the distribution of stresses in the bone and ligament elements of the foot. Methods. Mathematical modeling of the distal end of thelower extremity was performed. There are two variants of the position of the heel bone — varus and valgus with an angle of deviation from the vertical axis in both cases 15°. A vertical distributed load of 700 N was applied to the tibial plateau. On the supporting surface of the feet model's were rigidly fixed. Measurements of mechanical stresses were performed at control points. According to the criteria for estimating the stress-strain relations (SSR), the Misesstress was used. Results. It was determined that lateral malleolus hypoplasia increases the values of stresses on the lateral side of the distal tibial bone from 6.3 MPa to 6.4 MPa, from the medial — on the heel bone from 5.8 MPa to 6.0 MPa, talus from 2.1 MPa to 2.3 MPa. SSR on TCJ are also varies. In the case of a neutral position of the heel bone, lateral malleolus hypoplasia causes a decrease in the values of the ligaments on the lateral side of the TCJ,which can be explained by their elongation and, consequently, the projection increase in length In the case of varus or valgus position of the heel bone under conditions of lateral ankle hypoplasia, it was found that the varus position of the heel bone overstrains the ligaments on the lateral side, valgus - from the medial. Conclusions. Decreased stress in the ligaments of the TCJ in cases of valgus or varus position of the heel bone is one of the factors reducing the functional stability of the joint and may be the cause of its chronic instability.

Bone diagenesis in the marine environment‐I: Characterization and distribution of trace elements in terrestrial mammalian bones recovered from historic shipwrecks

AbstractUnlike the chemical composition and diagenetic modification of buried bones, subaqueous archaeological bone diagenesis has not been studied in detail. This observational work presents a macroscopic and microscopic characterization of 11 variably preserved archaeological terrestrial mammalian bones submerged in seawater and/or surrounded by marine sediment for 169–347 years. In situ trace element analysis was undertaken to identify geochemical fingerprints of diagenesis. The analyzed bones belong to a collection of underwater archaeological faunal materials excavated from four shipwreck sites. With one exception, all archaeological bones were fragmented, some were also heavily stained, and in two samples, the damage to the cortical layer was extensive. Bioerosion was assessed by scanning electron microscopy (SEM), and bone trace element chemistry (by laser ablation inductively coupled mass spectrometry—LA‐ICP‐MS) was compared with that of an unsubmerged modern sheep bone control. In the control, several trace elements were low in concentration (weighted mean concentration &lt;1 ppm; Cr, Co, Ni, Cu, Y, rare earth elements, Th, U). In the submerged archaeological bones, the weighted mean concentration of Li, Cr, Cu, and U was enriched relative to the modern sheep bone, whereas Rb and Ba were depleted. The best‐preserved bone, recovered from Batavia, showed less variation in trace element patterns compared with the more poorly preserved bones. The only archaeological bone with preserved macroscopic structure and cortex showed a gradual decrease in trace element concentration from the outer surface towards the medullary cavity, whereas in samples where more cortical damage was noted, the distribution of these elements is more irregular. With the exception of Cu and Cr, the elements focused on in this work (Li, U, Rb, and Ba) are nonessential to life, supported by their low concentration in the modern sheep bone (with the exception of Ba). The results suggest that early macroscopic and microscopic diagenetic alteration influences the concentration and distribution of chemical elements in submerged bones and that in situ trace element analysis provides clues for the reconstruction of taphonomic trajectories.

The Impact of Major and Trace Elements in Serum and Bone on Dual-Energy X-Ray Absorptiometry-Derived Hip Strength

The purpose of this study was to establish associations between both serum levels and bone content of a wide range of elements (Na, K, P, Ca, Mg, Zn, Cu, Cr, Mn, Fe, and Pb), with hip strength (HS) indices derived from dual-energy X-ray absorptiometry (DXA). The study population consisted of a number of male patients aged 56–77 years following hip replacement due to osteoarthritis of the hip. Bone specimens were taken from the femoral head and neck during arthroplasty. The elemental analyses were carried out using coupled plasma optical emission spectrometry. The following DXA-HS parameters were assessed: buckling ratio (BR), cross-sectional area (CSA) and its moment of inertia (CSMI), section modulus, and Femoral Strength Index (FSI). Age was positively correlated with Na, K, and Cu in the bone. Ca in the bone was positively associated with BR and negatively with SM and CSMI. Of all the DXA-HS parameters, the weakest associations of elements in the bone were found with FSI and the strongest with BR. Among the elements in the serum, the strongest negative associations were found for K, Cr, Mn, and Zn with CSA, while the majority of bone elements were associated either positively (Ca, P, Mg, Zn, and Cu) or negatively (Mn, Fe, Pb, and Cr) with BR. In conclusion, the interactions between individual elements in blood serum and bone with DXA-HS could not be unequivocally established.

Current Advances in the Roles of Doped Bioactive Metal in Biodegradable Polymer Composite Scaffolds for Bone Repair: A Mini Review

The election of bone tissue engineering scaffolds material is mainly based on the bionics of natural bones. Although the content of trace elements in bone is low, the lack of them affects the growth and metabolism of bones, thus increasing the risk of orthopedic diseases caused by the deterioration of bone quality. Therefore, inspired by trace elements in natural bone, biodegradable polymer composite scaffolds doped with bioactive metals such as Mg, Zn, Sr, Fe, Cu, Mn, Co, Li, Ag, Nb, and V have attracted more attention. Herein, the role of bioactive metals doping in biodegradable polymer matrix is mainly reviewed, including improving hydrophilicity, preventing aseptic inflammation caused by acidic degradation products, imparting antibacterial activity, improving mechanical properties, and promoting vascularization of polymer scaffolds. Then, the reasons and solutions for interfacial bonding and cytotoxicity caused by doping bioactive metals are focused on.

Nutritional reconstruction in an early modern population: Searching for a relationship between dental microwear and bone element composition

BackgroundObserving the microwear patterns of the dental crowns enamel surface can provide information on the ingredients and structure of the food consumed, but also on eating habits and lifestyle. Major role in reconstructing the diet and lifestyle of past populations is played by the analysis of alkaline earth metals, such as strontium, barium, zinc and calcium. Ba and Sr are indicators of the consumption of vegetables, plants (cereals and legumes) and marine organisms. This study aims to assess dietary diversity and identify its components based on microscopic techniques and chemical analyses of material from early modern archaeological sites in Wrocław, Poland. MethodsThe material consisted of 36 permanent molars and the intrasternal parts of 122 first ribs, collected from 6 Wroclaw early modern cemeteries. Tooth microwear was evaluated on Scanning electron microscopy images, with Microwear 4.02 software. Bone chemical composition (Ca, P, Ba, Sr content) was evaluated with mass spectrometry. ResultsMost lines were present on the teeth from St. Mary Magdalene Cemetery, with the lowest average number of lines observed on the teeth from St. Barbara Cemetery. The Ca/P ratios calculated for different sites formed two clusters that allows to distinguish two groups of archaeological sites with different bone preservation status. Number of differences in Ba/Sr, Sr/Ca, Ba/Ca ratios was found between disctinct archaeological sites. A number of correlations were found between the concentration of the chemical elements, but no statistically significant correlation was found between the microwear characteristics and the proportion of the elements studied. Some strong correlations were found between microwear features and the Ca/P ratio. Conclusionsthe different values of Sr/Ca, Ba/Ca and Ba/Sr ratios indicate different diets in the different communities. The data obtained indicate a mixed diet, with a relatively high proportion of animal products throughout Wrocław. Conclusions should be treated with caution due to secondary diagenesis. The lack of interdependence between microwear and chemical composition characteristics suggests that the two methods should be considered complementary and not overlapping, as they provide different insights into the diets of past populations. The comparison of microwear between different sites should always take into account secondary diagenesis and the burial environment, as these influence the characteristics of microwear.

Preparation and Physicochemical Evaluation of Hydroxyapatite-gelatin Nanoparticles

One of the promising fields of research is tissue engineering that can facilitate available therapeutic methods. Nanosized hydroxyapatite (HA) is one of the key elements in mineral bone. It is possible to affect the surrounding osteoprogenitor cells using nano-sized HA and through this improve bone repair through changing paracrine signaling. The present paper is an attempt to prepare and evaluate physicochemical properties of hydroxyapatite-gelatin nanoparticles. To this end, two sizes were prepared including S100 and S150 using standard chemical precipitation. To characterize the size and morphology of the synthesized powders, X-ray diffraction and Brunauer-Emmett-Teller (BET) surface area were determined using Autosrob-IQ2-MP. To measure the calcium ions released by HANPs, an inductively coupled plasma optical emission spectrometer (ICP-OES) was used. The collected data was analyzed in SPSS 19.0. In the case of S100, the hydrodynamic diameter based on DLS analyses was equal to 626.10±14.95nm; this figure for S150 was equal to 262.33±46.5. There was a larger specific surface area in S100 compared to S150; in addition, S100 had wider diffraction peaks, which is in agreement with small and poorly crystalline crystals. On the other hand, the diffraction peaks of S150 were sharper, which means that the crystallinity was higher in S150. In addition, HANPs of all sizes had degradability and HANPs with smaller sizes (S100) degraded faster compared to larger-sized S150. The pH level of the control, S100, and S150 was 7.24±0.01, and 7.26±0.02 so that there was no significant difference between them. Nanoparticle size is a key factor in the biological environment, which provides a reference for HANPs in biomedical uses.

Potential of Black Phosphorus in Immune‐Based Therapeutic Strategies

Black phosphorus (BP) consists of phosphorus atoms, an essential element of bone and nucleic acid, which covalently bonds to three adjacent phosphorus atoms to form a puckered bilayer structure. With its anisotropy, band gap, biodegradability, and biocompatibility properties, BP is considered promising for cancer therapy. For example, BP under irradiation can convert near-infrared (NIR) light into heat and reactive oxygen species (ROS) to damage cancer cells, called photothermal therapy (PTT) and photodynamic therapy (PDT). Compared with PTT and PDT, the novel techniques of sonodynamic therapy (SDT) and photoacoustic therapy (PAT) exhibit amplified ROS generation and precise photoacoustic-shockwaves to enhance anticancer effect when BP receives ultrasound or NIR irradiation. Based on the prospective phototherapy, BP with irradiation can cause a “double-kill” to tumor cells, involving tumor-structure damage induced by heat, ROS, and shockwaves and a subsequent anticancer immune response induced by in situ vaccines construction in tumor site, which is referred to as photoimmunotherapy (PIT). In conclusion, BP shows promise in natural antitumor biological activity, biological imaging, drug delivery, PTT/PDT/SDT/PAT/PIT, nanovaccines, nanoadjuvants, and combination immunotherapy regimens.

Assessment of Growth Plate Chondrocytes Proliferative Activity in Embryonic Endochondral Ossification via Ki-67 Immunofluorescence.

Cell proliferation is one of the key events that regulates organism development. In the limb, chondrocytes differentiate into amulti-layered cellular template called the growth plate. Chondrocyte proliferation is essential to provide the necessary cells that allow growth of a bone. Deregulated cell proliferation will lead to truncated bone elements. Immunofluorescence is a biological technique that uses specific antibodies to detect the subcellular localization of a proliferative marker within cellular or tissue context. In this chapter, we illustrate how to perform immunofluorescence to detect the localization of Ki-67 (a marker of actively growing/proliferating chondrocytes) in order to assess the growth fraction of the columnar chondrocytes in the growth plate in paraffin-embedded mouse tissue limb.

The state of the bone structures of the temporomandibular joint in dental patients with unilateral terminal defects of the dentition

The aim of the study was to evaluate morphological changes in the bone structures of the elements of the temporomandibular joint in patients with unilateral terminal defects of the dentition. The study involved 90 patients aged 18 to 44 years, who underwent: clinical examination of the maxillofacial region, cone-beam computed tomography with digital processing of computed tomograms in the Avantis 3D system, statistical processing of the results obtained. In the course of the study, two main samples were determined: depending on the side of the defect and on the duration of the appearance of the defect of the dentition. During the study of 90 computed tomograms of patients with unilateral terminal defects of the dentition and their further computer processing, the structural features of the bone elements of the temporomandibular joint were studied, the main morphometric changes of the mandibular heads were established, a comparative characteristic of morphometric parameters in the study groups was carried out. The identified structural changes in the heads of the lower jaw in patients with unilateral end defects of the dentition appear as a result of the presence of an untreated defect of the dentition for a long period of time.

Radiological analysis of size of bone elements of the temporomandibular joint in children and adolescents with class II malocclusion

The aim of the study was to assess the ratio of bone elements of the temporomandibular joint (TMJ) in children and adolescents with distal occlusion according to cone-beam computed tomography (CBCT). CBCT of the TMJ was analyzed in 121 patients aged 12-18 years, which were divided into two age groups: group I - children aged 12-15 years (62 cases in total, of which 47 patients with distal occlusion and 15 patients with physiological occlusion) and II group - adolescents aged 15-18 years (59 cases, of which 48 patients with distal occlusion and 11 patients with physiological occlusion). CBCT of the temporomandibular joint was performed by the standard method in the position of habitual occlusion and maximally open mouth. The size of the TMJ joint space in the anterior, upper and posterior sections was determined by the method of Rabukhina N.A., the analysis of the ratio of the bone elements of the TMJ was carried out using the Craniometry program. The size of the joint space and the angle β of the temporomandibular joint in the anterior section on the right and left in children aged 12-15 with distal occlusion is increased compared to children with physiological occlusion in the position of habitual occlusion. In adolescents 15-18 years old with distal occlusion, the size of the TMJ joint space is increased in the anterior section on the right and left and reduced in the posterior section on the right, angle α is reduced on the right and left, angle β is reduced on the right, angle γ is increased on the right compared to adolescents with physiological occlusion. The revealed deviations indicate the presence of violations in the ratio of the bone elements of the TMJ, which are aggravated with age. Analysis of the results obtained during CBCT in children and adolescents allows us to correct the plan of orthodontic treatment and predict its results.

Evaluation of maxillary bones using cone beam computed tomography: A systematic review

Cone beam computed tomography is widely used in dentistry, due to its easy accessibility, low cost and better accuracy compared to medical tomography. The present study aims to conduct a systematic review of the literature on the evaluation of jaw bones using cone beam computed tomography. A bibliographic search was performed in the electronic databases PubMed, Scopus, Embase and Web of Science. At the end of the analysis, 10 articles published between 1998 and 2015 were included. Cone beam computed tomography is a precise and fast method, used to evaluate digital images in high resolution, with sharpness, precision. In addition, the acquisition of these images is essential to measure bone elements, in quantity and quality. It should also be noted that the forecast of bone strength will depend on several factors, such as bone density and microarchitecture. Thus, the professional and reduces the likelihood of making mistakes, which interfere with the prognosis of dental treatment.

Tissue Distribution of Mercury and Its Relationship with Selenium in Atlantic Bluefin Tuna (Thunnus thynnus L.).

Mercury (Hg) is an important heavy metal to consider in marine predators, while selenium (Se) has a natural antagonistic effect on this metal in fish. The Atlantic bluefin tuna (ABFT, Thunnus thynnus) is a pelagic top-level predator of the trophic web and their Hg muscular content is an object of concern in food safety. Nevertheless, little is known about levels of this metal in remaining tissues, which may be important as by-product source, and its relationship with Se. Thus, concentration of both elements in liver, kidney, brain, gill and bone, in addition to muscle, of ABFT were determined. The kidney was the tissue with the highest concentration of Hg (Total-Hg, THg) and Se, and the Se/THg concentration ratio was similar in all tissues, except bone and muscle. The Selenium Health Benefit Value (HBVSe) was positive in each specimen and tissue, indicating that the Se plays an important role against Hg not only in the muscle.

Visualization of the Cartilage and Bone Elements in the Craniofacial Structures by Alcian Blue and Alizarin Red Staining.

Craniofacial morphogenesis is underpinned by orchestrated growth and form-shaping activity of skeletal and soft tissues in the head and face. Disruptions during development can lead to dysmorphology of the skull, jaw, and the pharyngeal structures. Developmental disorders can be investigated in animal models to elucidate the molecular and cellular consequences of the morphogenetic defects. A first step in determining the disruption in the development of the head and face is to analyze the phenotypic features of the skeletal tissues. Examination of the anatomy of bones and cartilage over time and space will identify structural defects of head structures and guide follow-up analysis of the molecular and cellular attributes associated with the defects. Here we describe a protocol to simultaneously visualize the cartilage and bone elements by Alcian blue and Alizarin red staining, respectively, of wholemount specimens in mouse models.

Direct STR typing from human bones

Identification by STR analysis of bones is time-consuming, mainly due to the lengthy decalcification required and complex DNA extraction process. To streamline this process, we developed a direct STR typing protocol from bone samples. We optimized bone sample amounts using femur and tibia and two commercial PCR kits (Identifiler™ Plus and IDplex Plus kits). Optimally, 100 mg of bone powder in 300 µL PBS buffer was heated at 98 °C for three minutes to produce a supernatant for DNA amplification. IDplex Plus performed better than Identifiler™ Plus in terms of allele recovery and peak height. Fifteen samples of each of seven bone elements (1st distal phalange of hand, capitate, femur, metacarpal 4, patella, talus, and tibia; N = 105) were then subjected to direct STR typing with the optimized protocol, and 94.3% were high partial to full profiles. The performance of the developed protocol was similar for all bone elements. Median peak heights were significantly better in profiles of cancellous bone than compact bone (p = 0.033) and significantly different across the bone elements (p < 0.001). Ten casework samples from various conditions and up to 7-year-PMI were subjected to both direct STR and conventional STR typing. No significant difference in the number of alleles was seen (95% HDI of −13.5 to 5.15). As well as being rapid, convenient, and safe, the protocol could help improve STR typing from bones.

MATHEMATICAL MODELING OF GRAFT FIXATION VARIANTS TO THE ANTERIOR MARGIN OF THE GLENOID PERFORMING LATARJET PROCEDURE

Latarjet procedure is a common standard in the treatment of anterior and anterior-inferior shoulder instability with a significant glenoid defect. However, like any other surgical technique, it has a list of certain intra- and postoperative complications, including mistakes in the positioning of the bone block. A necessary guarantee of prevention and reduction of the frequency of possible complications associated with graft positioning is a well-performedpreoperative planning with an understanding of the biomechanical functioning of the shoulder joint with the translated bone block. Objective. According to the mathematical modelling we studied the changes that occur in the stress-strain state of the shoulder joint model depending on the options for graft fixation and may occur during the Latarjet procedure. Methods. To solve this problem, a finite element model of the shoulder was created. The simulationswere performed using the SolidWorks computer-aided design system. The following situations were simulated: variants of fixing screws relative to the plane of the articular surface of the glenoid (parallel to the plane, at an angle of 10° and 20°) and variants of graft fixation height at the anterior edge of the glenoid (at the lower edge of the glenoid, 10 mm and 20 mm upper edge). Calculations of the stress-strain state of the models were performed with the CosmosM software package. Results and conclusions. The presence of a bone graft fixed with metal screws at the area of the defect at the anterior edge of the glenoid, leads to an increase in stress levels in the bone elements of the model. Changes in the stress-strain state of the shoulder model also occur, depending on the angle of the screws that secure the graft. The highest stress level was determined when providing the fixing screws at an angle of 10°, the lowest — when providing the screws parallel to the articular surface of the glenoid. The stresses on the locking screws increased slightly with increasing angle of the screws. When studying the height of graft fixation, the most favorable option, in terms of stress distribution on the articular surface of the glenoid and fixing screws, is its location in the lower part of the anterior edge of the glenoid.