Mineralized Tissue Research Articles

Multifaceted skeletal effects of sevelamer carbonate in a secondary hyperparathyroidism model.

Hyperphosphatemia leads to abnormal mineralization of bones and soft tissues in patients with chronic kidney disease-induced secondary hyperparathyroidism (CKD-SHPT). Sevelamer lowers phosphate levels by binding to dietary phosphate in the gastrointestinal system, forming new bone and reducing the risk of renal osteodystrophy and fracture. However, the influence of sevelamer carbonate (SevC) on bone microarchitecture, material qualities, and mechanical behavior is unknown in CKD-SHPT conditions. We utilized a rat model of CKD-induced hyperphosphatemia by feeding a 1.8% high-phosphate diet to 5/6 nephrectomized rats to test the effects of SevC on skeletal quality and strength, employing microCT, Fourier transform infrared spectroscopy (FTIR), 3-point bending, nanoindentation, and compression tests. SevC preserved mineral homeostasis and reduced PTH, and FGF-23 levels in CKD-SHPT rats. SevC mitigated the serum renal parameters, pyrophosphate levels, and indole acetic acid. In CKD-SHPT rats, SevC reduced hyperphosphatemia, improved the mineralization defect, and upregulated mineralization-promoting genes like ankyrin-1, ectonucleotide-pyrophosphatase/phosphodiesterase-1, tissue non-specific alkaline phosphatase, phosphate-regulating endopeptidase X-linked, dentin matrix protein-1, and matrix extracellular phosphoglycoprotein. In the cortical bones of CKD-SHPT rats, SevC increased cortical mass and thickness, decreased porosity by likely decreasing cortical bone remodeling induced by high PTH, and increased osteocyte preservation. SevC mitigated all of the alterations in the mineral and matrix composition of CKD-SHPT rats, including decreased collagen-maturity, mineral-to-matrix ratio, and increased carbonate substitution of hydroxyapatite crystals. SevC enhanced bone strength and mechanical behavior in CKD-SHPT rats at a macro (three-point bending) and nano (nanoindentation) scales. These findings in CKD-SHPT rats suggest that SevC improves bone mechanical properties at various levels by decreasing serum pyrophosphate, empty lacunae, and enhancing renal clearance of indole acetic acid, organized mineral-matrix deposition, and osteocyte number by suppressing cortical remodeling.

Exploration of the covariation signal between cortical bone and dentine volumes across the upper limb bones and anterior teeth in modern humans and relevance to evolutionary anthropology.

Cortical bone and dentine are two mineralized tissues sharing a common embryological origin, developmental, and genetic background, distinct from those of enamel. Understanding their relationship is crucial to decipher the factors acting on their postnatal development, and shedding light on the evolutionary patterns of tissue proportions. Here, we investigate the coordinated variation between cortical bone and dentine volumes measured from arm and forearm bones (humeri, ulnae, radii) and upper anterior teeth (central incisors, lateral incisors, canines) of modern humans. Given the shared characteristics of cortical bone and dentine, we expect similarities in their postnatal development, which may lead to covariation between their volumes. The degree of bone-dentine covariation may be influenced by the physiological response of upper limb bones to mechanical loading. No such covariation is expected with enamel volumes, due to the greater developmental independence of bone and enamel. Our sample includes 55 adults of African and European ancestries from South African osteological collections. Principal component analysis of cortical thickness variation along the shafts of paired humeri, ulnae, and radii is used to assess asymmetry. Bone regions with bilateral asymmetry in cortical bone thickness are considered sensitive to functional loads, while regions with minimal bilateral variation likely reflect genetic influences during bone postnatal development. Statistical analyses reveal strong positive correlations between cortical bone and dentine volumes across all bones and teeth, and weaker correlations between cortical bone and enamel. We outline a complex pattern of bone-dentine covariation that varies by skeletal location and tooth type. Contrary to our expectations, the presumed functional sensitivity of bone regions does not influence the covariation signal. Additionally, the strength of the covariation appears to align with the developmental sequence of the anterior teeth, with the upper canines showing the strongest correlation with cortical bone volumes, followed by lateral and central incisors. These results provide insights into the functional and biological factors influencing the coordinated variation of cortical bone and dentine volumes during postnatal development. Further research on the cortical bone-dentine covariation across different skeletal parts, including lower limb elements, would enhance our understanding of the effects of both endogenous and exogenous factors on the development of the mineralized tissues.

REVISITING THE PHYSICAL AND CHEMICAL NATURE OF THE MINERAL COMPONENT OF BONE.

The physico-chemical characteristics of bone mineral remain heavily debated. On the nanoscale, bone mineral resides both inside and outside the collagen fibril as distinct compartments fused together into a cohesive continuum. On the micrometre level, larger aggregates are arranged in a staggered pattern described as crossfibrillar tessellation. Unlike geological and synthetic hydroxy(l)apatite, bone mineral is a unique form of apatite deficient in calcium and hydroxyl ions with distinctive carbonate and acid phosphate substitutions (CHAp), together with a minor contribution of amorphous calcium phosphate as a surface layer around a crystalline core of CHAp. In mammalian bone, an amorphous solid phase has not been observed, though an age-dependent shift in the amorphous-to-crystalline character is observed. Although octacalcium phosphate has been postulated as a bone mineral precursor, there is inconsistent evidence of calcium phosphate phases other than CHAp in the extracellular matrix. In association with micropetrosis, magnesium whitlockite is occasionally detected, indicating pathological calcification rather than a true extracellular matrix component. Therefore, the terms 'biomimetic' or 'bone-like' should be used cautiously in descriptions of synthetic biomaterials. The practice of reporting the calcium-to-phosphorus ratio (Ca/P) as proxy for bone mineral maturity oversimplifies the chemistry since both Ca2+ and PO43- ions are partially substituted. Moreover, non-mineral sources of phosphorus are ignored. Alternative compositional metrics should be considered. In the context of bone tissue and bone mineral, the term 'mature' must be used carefully, with clear criteria that consider both compositional and structural parameters and the potential impact on mechanical properties. STATEMENT OF SIGNIFICANCE: Bone mineral exhibits a unique hierarchical structure and is classified as intrafibrillar and extrafibrillar mineral compartments with distinct physico-chemical characteristics. The dynamic nature of bone mineral, i.e., evolving chemical composition and physical form, is poorly understood. For instance, bone mineral is frequently described as "hydroxy(l)apatite", even though the OH- content of mature bone mineral is negligible. Moreover, the calcium-to-phosphorus ratio is often taken as an indicator of bone mineral maturity without acknowledging substitutions at calcium and phosphate sites. This review takes a comprehensive look at the structure and composition of bone mineral, highlighting how experimental data are misinterpreted and unresolved concerns that warrant further investigation, which have implications for characterisation of bone material properties and development of bone repair biomaterials.

Influence of Grafting on Crop Productivity and Performance Using Pepper Landrace Rootstocks Under Salinity Conditions

This study was conducted at Al-Karamah Research Station - National Agricultural Research Center in the Jordan Valley, the Hashemite Kingdom of Jordan during the 2021/2022 growing season to investigate the impact of grafting on crop productivity and fruit quality parameters of a commercial pepper variety (Passion) using three pepper local landraces as rootstocks under salinity stress conditions. A split-plot experimental design system was used, where two salinity levels were the main plot treatments (2.0 dS m-1 and 4 dS m-1), and four sub-plot treatments were grafting combinations (JO 204 X Passion, JO 207 X Passion, JO 109 X Passion, and Passion as a non-grafted control treatment). Pepper productivity, total phenols, antioxidant enzyme (SOD) content, chlorophyll content in leaves, and plant leaf and root tissue minerals content were measured. The results revealed that grafting using landrace rootstocks mitigated the negative effects of salinity on nutrient uptake, accumulation, and distribution. All plants exhibited increased Na+ content under salt stress but non-grafted plants exhibited higher accumulation of toxic ions under salt stress. Moreover, salt-tolerant pepper rootstock landraces selectively absorbed higher K+ and Ca +2 ion levels than non-grafted plants. In addition, peppers grafted onto landraces exhibited enhanced antioxidant content and less oxidation stress measured as the content of MDA. All this led eventually to better productivity and fruit quality of the grafted pepper plants. Pepper Landrace (JO 207) was identified as a promising salt-tolerant accession, holding potential for future utilization in the production of grafted pepper seedlings.

The Multifactorial Relationship Between Bone Tissue Water and Stiffness at the Proximal Femur

Bone mechanical function is determined by multiple factors, some of which are still being elucidated. Here, we present a multivariate analysis of the role of bone tissue composition in the proximal femur stiffness of cadaver bones (n = 12, age 44–93). Stiffness was assessed by testing under loading conditions simulating a sideways fall onto the hip. Compositional properties of cortical and trabecular tissues were quantified in femoral neck cross sections by Fourier transform infrared (FTIR) spectroscopy and near infrared (NIR) spectroscopy. In addition, cross-sectional areas and cortical thickness and tissue mineral density (TMD) were measured at the femoral neck. Pearson correlation analysis showed a significant (p < 0.05) negative relationship between bone stiffness and cortical and trabecular water content, both total (r = -0.63) and tightly bound to matrix and mineral (r = -55). Additionally, significant (p < 0.05) positive correlations were found between stiffness and bone area, both total (r = 0.67) and trabecular (r = 0.58). However, linear regression using each of these properties to predict bone stiffness resulted in weak models (R2 = 0.36–0.48). Interestingly, we found markedly stronger models (cross-validated R2 = 0.80–0.92) by using partial least squares (PLS) regression to predict stiffness based on combinations of bone properties. The models with highest R2 values were found when including bone water parameters as explanatory variables, both total and tightly bound, in cortical and trabecular. This study provides new insights by revealing a multifactorial relationship in which higher bone water content across different tissue compartments contributes to lower bone stiffness, highlighting bone water as a potential biomarker of bone quality and proximal femur mechanical function.

Bilateral laryngeal paralysis following single‐staged, bilateral total ear canal ablation and lateral bulla osteotomy in a cocker spaniel

AbstractAn 8‐year‐old, spayed, female cocker spaniel was presented for surgical treatment of otitis externa and media/interna that was unresponsive to medical management. Preoperative computed tomography imaging revealed bilateral otitis externa and media/interna. Extensive soft tissue proliferation and mineralisation of the ear canals were present. Both tympanic bullae had lysis and proliferative bony changes. The dog underwent single‐staged, bilateral total ear canal ablation and lateral bulla osteotomies. Following recovery from anaesthesia, inspiratory respiratory distress developed. Visual examination of the larynx documented bilateral laryngeal paralysis. Palliation with unilateral arytenoid lateralisation was declined and despite 9 days of antimicrobials, anti‐inflammatory medication, oxygen therapy and supportive care, inspiratory respiratory distress persisted. The dog was euthanased due to inability to breathe comfortably without supplemental oxygen. Bilateral laryngeal paralysis was considered secondary to iatrogenic surgical trauma to the vagus nerve.

Skeletal and dental tissue mineralization: The potential role of the endoplasmic reticulum/Golgi complex and the endolysosomal and autophagic transport systems.

This paper presents a review of the potential role of the endoplasmic reticulum/Golgi complex and intracellular vesicles in mediating events leading to or associated with vertebrate tissue mineralization. The possible importance of these organelles in this process is suggested by observations that calcium ions accumulate in the tubules and lacunae of the endoplasmic reticulum and Golgi. Similar levels of calcium ions (approaching millimolar) are present in vesicles derived from endosomes, lysosomes and autophagosomes. The cellular level of phosphate ions in these organelles is also high (millimolar). While the source of these ions for mineral formation has not been identified, there are sound reasons for considering that they may be liberated from mitochondria during the utilization of ATP for anabolic purposes, perhaps linked to matrix synthesis. Published studies indicate that calcium and phosphate ions or their clusters contained as cargo within the intracellular organelles noted above lead to formation of extracellular mineral. The mineral sequestered in mitochondria has been documented as an amorphous calcium phosphate. The ion-, ion cluster- or mineral- containing vesicles exit the cell in plasma membrane blebs, secretory lysosomes or possibly intraluminal vesicles. Such a cell-regulated process provides a means for the rapid transport of ions or mineral particles to the mineralization front of skeletal and dental tissues. Within the extracellular matrix, the ions or mineral may associate to form larger aggregates and potential mineral nuclei, and they may bind to collagen and other proteins. How cells of hard tissues perform their housekeeping and other biosynthetic functions while transporting the very large volumes of ions required for mineralization of the extracellular matrix is far from clear. Addressing this and related questions raised in this review suggests guidelines for further investigations of the intracellular processes promoting the mineralization of the skeletal and dental tissues.

Degeneration of the nucleus pulposus affects the internal volumetric strains and failure location of adjacent human metastatic vertebral bodies.

Intervertebral disc (IVD) degeneration is suspected to affect the distribution of stress and strain near the vertebral endplates and in the underlying bone. This scenario is worsened by the presence of metastatic lesions on the vertebrae (primarily thoracic vertebrae (60-80%)) which increase the risk of fracture. As such, this study aimed to evaluate the effect of IVD degeneration on the internal volumetric strains and failure modes of human metastatic vertebral bodies. Five human thoracic spinal segments including one vertebra with lytic metastases and one radiologically healthy vertebra (control) were in-situ tested in pure compression within a mCT scanner (isotropic voxel size = 39 mm). Each specimen was tested in the elastic regime before and after inducing mock IVD degeneration (enzymatic degeneration with collagenase); and at failure after IVD degeneration. The volumetric strain field was measured using a global Digital Volume Correlation approach (BoneDVC). After IVD degeneration, larger maximum (+187%, P = 0.002, 95% CI= [-4447, -1209]) and minimum (+174%, P = 0.002, 95% CI= [1679, 4258]) principal strains were observed in both metastatic and control vertebrae, with peak differences in correspondence of the IVD anulus fibrosus. IVD degeneration caused a transversal fracture pattern in the vertebrae with failure location onset in the middle portion of the vertebral body and in the cortical shell. In conclusion, IVD degeneration was found to be a key factor in determining the failure mode, suggesting the clinical relevance of including IVD level of degeneration to assess patients' risk of spinal instability. STATEMENT OF SIGNIFICANCE: Vertebrae can be affected by pathologies, like bone metastases, while intervertebral discs tend to degenerate during life. Generally, these structures and pathologies are studied separately. In this study, we explored the effects of artificial intervertebral disc degeneration on the mineralised tissues of the vertebrae with metastases. We observed that the induced intervertebral disc degeneration changes the mechanical behaviour of the vertebral trabecular bone. We believe that the findings of this study may influence the scientific community to develop new clinical tools for the prediction of the risk of fracture in vertebrae with spinal metastases, including the degeneration of the intervertebral discs as a parameter.

The Role of Serum Vitamin D Levels and Vitamin D Receptor (VDR) Gene Variants on Dental Caries.

Vitamin D helps the mineralization of bone, teeth, and other calcified tissues by regulating calcium-phosphate metabolism. The nuclear activation of the vitamin D receptor (VDR) gene is essential for the effectiveness of vitamin D. The main objective of this study is to determine the role of vitamin D levels and VDR gene variants in dental caries. This study included 128 3-6-year-old children who were divided into 64 caries-free and 64 carious children. Blood samples were taken, and serum 25-hydroxyvitamin D levels were measured. Intraoral examinations were performed to record dmft index values. Genetic testing was performed on 26 children to examine VDR gene variations. Relevant gene regions were amplified using PCR and sequenced via Sanger sequencing in a total of 13 caries-free and 13 carious children. Stats analyses included chi-square/trend tests to compare count data; Student's T/Mann-Whitney U tests for two-group normally/non-normally distributed data; and the Kruskal-Wallis test for 3+ groups with non-normal data. The results showed that vitamin D levels were relatively low in the caries group, but no statistically significant relationship was found between vitamin D levels and caries. No mutations were detected in the VDR gene in either group, and there was no significant difference observed in terms of the number of ApaI, TaqI, and FokI polymorphisms. Based on these findings, the use of prophylactic vitamin D supplements to prevent caries formation or development cannot be recommended. This study provides important insights into the relationship between vitamin D and dental caries and can contribute to the development of effective preventive strategies for oral and dental health.

In vivo impact on rabbit subchondral bone of viscosupplementation with a hyaluronic acid antioxidant conjugate

ObjectiveThis study aimed to assess the effects of an antioxidant-conjugated Hyaluronic Acid (HA), specifically HA-4-aminoresorcinol (HA4AR), on articular cartilage and subchondral bone in osteoarthritis (OA). We conducted a comparative analysis between HA4AR and a commercially available high molecular weight HA formulation in a rabbit model of OA.Materials and methodsEighteen rabbits underwent unilateral anterior cruciate ligament transection (ACLT) and were divided into three groups of six: Saline-group, HA-group, and HA4AR-group, based on the type of intra-articular injection received. Additionally, eight non-operated contralateral knees served as reference points (Contralateral-group). Six weeks post-surgery, iodine-enhanced micro-computed tomography imaging was used to evaluate articular cartilage volume and thickness, and to assess subchondral bone microarchitecture and mineral density.ResultsCartilage thickness in both the HA and HA4AR groups was comparable to that of the Contralateral group. Notably, there was a significant reduction in subchondral bone plate tissue mineral density in the HA-group when compared to both the HA4AR and Saline groups (p < 0.05). However, no significant differences in trabecular subchondral bone microarchitectural parameters and mineral densities were observed between the HA4AR-group and the Saline-group. When compared to the Contralateral, Saline, and HA4AR groups, the HA-group exhibited a marked decrease in subchondral bone plate tissue mineral density (p < 0.05). Additionally, a significant reduction in trabecular bone volume fraction was noted in the HA-group compared to the Contralateral-group (p < 0.05).ConclusionsThe HA-4AR hydrogel demonstrated significant preservation of subchondral bone plate tissue mineral density compared to HA alone, while other bone microarchitectural parameters remained largely unchanged. These findings indicate that HA-4AR may provide enhanced osteoprotective benefits in the treatment of osteoarthritis.

FOOT RADIOGRAPHY IN EUROPEAN BISON (BISON BONASUS).

Bone lengths of paired digits of front and hind limbs from 12 captive European bison (Bison bonasus) of different ages (from nine to 175 months) and sexes were measured on digital radiographs in palmarodorsal (PaD) and dorsoplantar (DPl) projections of each limb. All bone lengths were measured, and lateral/medial ratios calculated. The bone measurements included length of the canon bone condyle (LCBC), length of the first, second, and third phalanges (LP1, LP2, LP3), and overall digit length (OL). Furthermore, radiographic abnormalities such as new bone formation (NBF), soft tissue mineralization (SFT), osteolysis (OS), widened vascular channels (WVC), and soft tissue swelling (STS) were recorded using PaD, DPl, and oblique projections. NBF and SFT received a single combined grade as without radiographic changes (0), mild (one to 10 changes = 1), moderate (11 to 20 changes = 2), and severe (>20 changes = 3). OS, WVC, and STS were graded as 0 = absent and 1 = present. There were no significant differences (P > 0.1) of lateral to medial ratios for LCBC, LP1, LP2, and OL in front limbs as compared with hind limbs. Only LP3 was significantly longer (P = 0.004) in the lateral digit of the hind limbs as compared with the front limbs. For both the front and the hind limbs, the lateral LCBC, LP1, LP2, LP3 and OL were significantly longer than the respective measurements of the medial bones (P < 0.05), except for LP2 and LP3 of the hind limbs. Length measurement ratios did not vary significantly with age (P > 0.1). The most common radiographic changes were both NBF and SFT, observed in all animals from 39 months of age and older. This study provides baseline data on in vivo radiographic anatomy and evaluation of feet of European bison under field conditions.

Bioactive Properties of Phosphate-Modified Silicon Oxycarbide Protective Coatings: Morphology and Functional Evaluation.

This article presents a study on the functional properties and morphology of coatings based on amorphous silicon oxycarbide modified with phosphate ions and comodified with aluminum and boron. The objective of this modification was to enhance the biocompatibility and bioactivity without affecting its protective properties. The comodification was aimed toward stabilization of phosphate in the structure. The coatings were prepared according to the typical procedure for polymer-derived ceramics: synthesized via the sol-gel method, deposited using the dip-coating technique, and subsequently pyrolyzed. Comprehensive analyses of the morphology, surface properties, corrosion resistance, and bioactivity were conducted to assess their functional performance. The coatings exhibited uniform and smooth surfaces, with phase separation observed in the boron-modified SiBPOC series. Surface wettability and free energy measurements demonstrated that SiPOC and SiBPOC coatings possessed moderate hydrophilicity and favorable surface free energy for cell adhesion and bone tissue mineralization. Corrosion resistance tests in Ringer's solution revealed that SiBPOC coatings provided the highest protection against ion leaching, while SiAlPOC showed decreased resistance due to surface cracks. Bioactivity tests indicated calcium phosphate precipitation on the surface of all samples with higher hydroxyapatite formation on SiPOC and SiAlPOC coatings. In vitro tests using MG-63 osteoblast-like cells confirmed the biocompatibility of the coatings, with SiPOC and SiBPOC exhibiting the best combination of bioactivity, cell adhesion, and proliferation. These findings suggest that the phosphate- and boron-modified SiOC-based coatings are promising candidates for enhancing bone integration in orthopedic implants.

Treatment of external root resorption with Biodentine in a tooth with a periodontal pocket: a case report with 2-year follow-up

External root resorption is characterized by the loss of mineral tissues in the dental root. This condition is difficult to diagnose, and if not identified early, it can lead to tooth extraction. The treatment consists of surgical access, removal of granulation tissues, and sealing the area with a biological material. Objective: This article reports on the treatment of ERR in the middle third of the root, associated with an 8 mm periodontal pocket using Biodentine, with a two-year follow-up. Case report: A 57-year-old woman attended complaining of discomfort in the palate. After a thorough medical history, clinical, radiographic, and tomographic evaluation, the final diagnosis was External Root Resorption. Concerned about preserving the tooth, it was suggested to fill the resorption with Biodentine and regular follow-ups. The patient agreed, and a tissue flap was raised in the palatal region, followed by sealing of the perforation with Biodentine and suturing. After 7 days, the sutures were removed, and during the six-month and two-year follow-ups, the tooth exhibited no mobility, good periodontal health, and maintained its function. Conclusion: The case demonstrated a reduction in the periodontal pocket (from 8 mm to 4 mm), maintenance of the tooth, and the effectiveness of Biodentine in treating ERR, even when exposed to the oral cavity.

Investigating The Role of Elastin and Extracellular Matrix Damage in Cardiovascular Calcification

Although calcification in the cardiovascular system is highly studied, the mechanisms behind it are not well understood. Current proposed mechanisms focus on cellular processes leading to, or controlling the unwanted mineralization in soft tissues. However, extracellular components such as collagen and elastin fundamentally regulate the mechanical properties of heart tissues. Here, we report on a toolkit to control the composition of tissues through the selective digestion of extracellular matrix (ECM) components, which can be used to design disease-specific in vitro models. Using this technique, we show that elastin as well as matrix tissue damage may play major role in cardiovascular calcification. This study highlights a novel approach to understand the role of proteins in soft tissue calcifications and may lead to the development of strategies to treat and prevent these unwanted pathological disorders.

РИСК ОСТЕОПОРОЗА У ЖЕНЩИН С ВЫЯВЛЯЕМЫМИ ПРИ МАММОГРАФИИ СОСУДИСТЫМИ КАЛЬЦИНАТАМИ МОЛОЧНЫХ ЖЕЛЕЗ

Abstract. Introduction. Calcium salt deposits in the breast vessel walls can share the mutual mechanisms compared to the ones of bone tissue mineralization mediated by the osteoprotegerin or receptors of the protein glycation end products. Aim: To assess the risk of osteoporosis or other mineral turnover disturbances in women with breast vascular calcifications found on mammography. Materials and Methods. Our study included 189 female patients who underwent mammography in 2018 and then were followed up to the year 2023. They were divided into the three groups: No calcifications group, moderate (grade 1-2) calcifications group, and pronounced (grade 3-4) calcifications group. All the patients underwent screening mammography, the dual-energy X-ray absorptiometry, and serum biochemistry tests (25-hydroxyvitamin D, total and ionized calcium, phosphorus, and magnesium). Results and Discussion. In 2018, 57 (30.16%) patients had breast vascular calcifications. The increased calcification degree was associated with the age. The most significant changes were found in TBS T-score values: In the moderate calcifications group, it was 27.5% lower compared to the no calcifications group (p=0.042); while in the pronounced calcifications group, it was 41.7% lower compared to the no calcifications group (p=0.007). Conclusions. Breast vascular calcifications are associated with the significant drop of TBS T-score values (from -2.31 to -3.97; р=0.008).

Fibroblast growth factor 23 – A review with particular reference to the physiology and pathophysiology of phosphate homeostasis in the cat

Fibroblast growth factor-23 (FGF23) is a phosphaturic hormone, discovery of which has transformed our understanding of mineral regulation in healthy mammals, including the cat. It is produced by osteoblasts and osteocytes and its prime role is to regulate phosphate entry into extracellular fluid (from bone and via the gut) and its excretion via the kidney. It interacts with other hormones (calcitriol and parathyroid hormone), inhibiting their activation and secretion respectively and so impacts on calcium as well as phosphate homeostasis. Physiological factors regulating its secretion are not well understood, although phosphate ion sensing is likely to be important. Calcium and magnesium ions are also involved and unravelling the control points and integration of the system regulating bone turnover and mineral balance whilst preventing soft tissue (non-osseous) mineralisation is a future research goal. Calciprotein particle size and number likely play an important role in this system but precisely how remains to be determined. Elevated serum FGF23 is the earliest indicator of mineral bone disorder associated with chronic kidney disease in human patients and in cats, enabling reference-range serum phosphorus to be maintained despite reduction in glomerular filtration rate which limits phosphate excretion. FGF23 also predicts CKD progression and survival in cats. The many factors influencing its secretion at different stages of CKD, including relative iron deficiency, anaemia and chronic systemic inflammation, hypomagnesaemia and α-klotho deficiency are discussed in this review, where the data available in cats with naturally occurring CKD is presented alongside that from rodent models and human CKD patients.

The potential of supplementing compound organic trace elements at lower levels in Chinese yellow-feathered broiler diets, Part I: Impacts on plasma biochemical parameters, antioxidant capacity, carcass traits, meat quality, and tissue mineral deposition

This study was conducted to evaluate the effects of replacing inorganic trace minerals (ITM) with compound organic trace minerals (OTM) at lower levels on plasma biochemical parameters, antioxidant capacity, carcass traits, meat quality, and tissue mineral deposition in Chinese yellow-feathered broilers. A total of 960 one-day-old male broilers were randomly allocated to six treatment groups. The birds were fed with either the basal diets (negative control, NC), or diets supplemented with 1,000 mg/kg (positive control, PC), 300 mg/kg, and 500 mg/kg ITM or OTM for 53 d, respectively. The results showed that the alkaline phosphatase (ALP) activity of the OTM300 group was significantly higher than that of the NC, PC, and ITM300 groups (P < 0.05). Dietary OTM supplementation could significantly increase the serum concentrations of Fe and Cu, promote the deposition of Zn and Cu in breast muscle, and increase Zn content in the tibia of Chinese yellow-feathered broilers (P < 0.05). Furthermore, dietary OTM300 treatment could significantly increase plasma CAT and CuZn-SOD activities, as well as the CAT activity in the liver (P < 0.05). The liver GSH-Px activity of the OTM500 group were significantly higher than the other groups (P < 0.05). Moreover, the supplementation of dietary OTM could significantly increase the pH45min of breast muscle, as well as decrease drip loss24h and drip loss48h of Chinese yellow-feathered broilers (P < 0.05). Furthermore, pH45min was positively correlated with liver T-AOC activity and the concentrations of Zn, Fe, Cu, and Mn in breast muscle, while drip loss48h was negatively correlated with liver T-AOC activity, plasma CAT and CuZn-SOD, as well as the concentration of Cu and Zn in breast muscle. Trace mineral sources or levels had no significant effect on the carcass traits of Chinese yellow-feathered broilers (P > 0.05). Compared with the ITM groups, OTM300 significantly increased the heart index of Chinese yellow-feathered broilers (P < 0.05). Dietary OTM upregulated the mRNA expression of TGF-β and downregulated the mRNA expression of IL-1β in the spleen (P < 0.05). In conclusion, dietary supplementation with compound OTM at lower levels could promote the deposition of trace minerals in serum and tissues, enhance antioxidant capacity, and improve the meat quality of Chinese yellow-feathered broilers.

Long-duration type 1 diabetes is associated with deficient cortical bone mechanical behavior and altered matrix composition in human femoral bone.

Type 1 diabetes (T1D) is associated with an increased risk of hip fracture beyond what can be explained by reduced bone mineral density, possibly due to changes in bone material from accumulation of advanced glycation end products (AGEs) and altered matrix composition, though data from human cortical bone in T1D are limited. The objective of this study was to evaluate cortical bone material behavior in T1D by examining specimens from cadaveric femora from older adults with long-duration T1D (≥50years; n= 20) and age- and sex-matched non-diabetic controls (n= 14). Cortical bone was assessed by mechanical testing (4-point bending, cyclic reference point indentation, impact microindentation), AGE quantification (total fluorescent AGEs, pentosidine, carboxymethyl-lysine (CML)), and matrix composition via Raman spectroscopy. Cortical bone from older adults with T1D had diminished post-yield toughness to fracture (-30%, P=.036), elevated levels of AGEs (pentosidine, +17%, P=.039), lower mineral crystallinity (-1.4%, P=.010), greater proline hydroxylation (+1.9%, P=.009), and reduced glycosaminoglycan (GAG) content (-1.3%, P<.03) compared to non-diabetics. In multiple regression models to predict cortical bone toughness, cortical tissue mineral density (Ct.TMD), CML, and Raman spectroscopic measures of enzymatic collagen crosslinks and GAG content remained highly significant predictors of toughness, while diabetic status was no longer significant (adjusted R2> 0.60, P<.001). Thus, impairment of cortical bone to absorb energy following long-duration T1D is well explained by AGE accumulation and modifications to the bone matrix. These results provide novel insight into the pathogenesis of skeletal fragility in individuals with T1D.

Dietary supplementation with fermented &lt;i&gt;Broussonetia papyrifera&lt;/i&gt; enhances tissue mineral deposition and intestinal microbiome in finishing pigs

Dietary supplementation with fermented &lt;i&gt;Broussonetia papyrifera&lt;/i&gt; enhances tissue mineral deposition and intestinal microbiome in finishing pigs

COMPARATIVE CHARACTERISTICS OF METHODS FOR THE PREVENTION OF DENTAL CARIES IN CHILDREN OF EARLY CHILDHOOD

The high prevalence and intensity of early childhood caries in Ukraine and in the world indicate insuffi cient attention of practical dentistry to the prevention of dental caries in young children. The development of adapted prevention programs considering the risk factors for the development of the disease remains relevant.Aim of the study. To compare the eff ectiveness of methods of pre- and postnatal prevention of early childhood dental caries based on correction of the microbial environment of the oral cavity and macro- and microelemental nutrition.Material and methods. The work was carried out within the framework of the research work of the Department of Pediatric Dentistry of the Bukovinian State Medical University «Development of methods of prevention and treatment of major dental diseases in children, taking into account the risk factors of their development» (DR # 0121U110122). The prenatal method of dental caries prevention was applied to a group of pregnant women (30 persons) whose average age was (25,17±1,05) years. It included the use of Elevit Pronatal and Iodomarin 200, one tablet daily, starting from the second trimester ofpregnancy, and a course of local probiotic therapy with BioGaya ProDentis chewable tablets, used for 20 days in the second trimester of pregnancy and 20 days before delivery. As a method of postnatal prevention of dental caries in children, a preventive complex was used, including the use of the probiotic BioGaya ProDentis and the vitamin and mineral complex Supervit. The course lasted three weeks twice a year. The preventive complex was applied to a group of children aged 2-3 years. The number of children in the control group was 30. The mean age of the group was (2.51±1.30) years. The eff ectiveness of preventive measures was evaluated by the prevalence and intensity of caries of primary teeth («kpv» and «kpppv»), the state of oral hygiene (M. E. Kuzmina index), the content of phosphate ions, inorganic and ionized calcium in the oral fluid of children, the content of mutans streptococci in the oral cavity and the concentration of sIgA in the oral fl uid of children. Statistical processing of the study results was performed using standard methods of variation. The study complied with all bioethical norms (conclusion of the Bioethics Commission of the Bukovinian State Medical University No. 4 dated 15.12.2022).Results of the study. The use of preventive complexes for early childhood caries, based on the supplementation of macro- and microelements and the infl uence on the microbial landscape of the oral cavity, are eff ective methods of prevention of caries of temporary teeth in children, which is confi rmed by a decrease in the prevalence and intensity of dental caries in children in the dynamics of their observation. Prenatal measures are more eff ective in the prevention of early childhood caries in children, as they optimize the processes of primary mineralization of hard dental tissues and thus strengthen them, reducing the risk of dental caries. Postnatal use of the drugs has a slightly lower preventive eff ect on early childhood caries, while it has a positive eff ect on the processes of secondary mineralization of tooth enamel, as it was found that the level of phosphate ions in the oral fl uid of children under these conditions increased by 23.72 % (p&lt;0.05), and the level of total calcium decreased by 15.84 % and its free fraction by 25.86 % (p&lt;0.05).Conclusions. Our results suggest that both methods of prevention of early childhood caries are eff ective, but prenatal prophylaxis is clinically more eff ective with respect to the hard tissues of temporary teeth in children, due to its eff ect on the processes of primary mineralization of enamel. Postnatal prophylactic measures have a positive eff ect on the secondary mineralization of the hard tissues of temporary teeth and the primary mineralization of permanent teeth and will have a clinical result in the long term.