Nutrition in bone health revisited: a story beyond calcium

Advancing atom probe tomography capabilities to understand bone microstructures at near-atomic scale

Bone structure is generally hierarchically organized into organic (collagen, proteins, ...), inorganic (hydroxyapatite (HAP)) components. However, many fundamental mechanisms of the biomineralization processes such as HAP formation, the influence of trace elements, the mineral-collagen arrangement, etc., are not clearly understood. This is partly due to the analytical challenge of simultaneously characterizing the three-dimensional (3D) structure and chemical composition of biominerals in general at the nanometer scale, which can, in principle be achieved by atom probe tomography (APT). Yet, the hierarchical structures of bone represent a critical hurdle for APT analysis in terms of sample yield and analytical resolution, particularly for trace elements, and organic components from the collagen appear to systematically get lost from the analysis. Here, we applied in-situ metallic coating of APT specimens within the focused ion beam (FIB) used for preparing specimens, and demonstrate that the sample yield and chemical sensitivity are tremendously improved, allowing the analysis of individual collagen fibrils and trace elements such as Mg and Na. We explored a range of measurement parameters with and without coating, in terms of analytical resolution performance and determined the best practice parameters for analyzing bone samples in APT. To decipher the complex mass spectra of the bone specimens, reference spectra from pure HAP and collagen were acquired to unambiguously identify the signals, allowing us to analyze entire collagen fibrils and interfaces at the near-atomic scale. Our results open new possibilities for understanding the hierarchical structure and chemical heterogeneity of bone structures at the near-atomic level and demonstrate the potential of this new method to provide new, unexplored insights into biomineralization processes in the future. STATEMENT OF SIGNIFICANCE: Atom probe tomography (APT) is a relatively new technique for the analysis of bones, teeth or biominerals in general. APT can characterize the microstructure of materials in 3D down to the near-atomic level, combined with a high elemental sensitivity, down to parts per million. APT application to study biomineralization phenomena is plagued by low sample yield and poorer analytical performance compared to metals. Here we have overcome these limitations by in-situ metal coating of APT specimens. This can unlock future APT analysis to gain insights into fundamental biomineralization processes, e.g. collagen/hydroxyapatite interaction, influence of trace elements and a better understanding of bone diseases or bone biomineralization in general.

Impact loading exercise induced osteogenesis from childhood to early adulthood in tennis players aged 8-30 years

Osteogenesis with impact-loading exercise is often assessed by the extra bone growth induced in the loaded arm of tennis players. We used PRISMA to explore % bone mineral content (BMC) and area (BA) asymmetry in players 8-30 years according to weekly training hours, age, sex, maturity, and bone segment. Proper statistics for 70 groups were extracted by two reviewers from 18 eligible studies of low risk of bias (< 35, STROBE) and good quality (> 70%). The quality of the review was high (AMSTAR, 81%). Using "random effects" we tested moderation-specific meta-comparisons and meta-regressions. The loaded bones % hypertrophy was higher in BMC (19%) than BA (10%), and, with BMC and BA merged, in boys (17%) than girls (13%), in humerus (19%) than radius-ulna (14%), and in pubertal (19%) players. Weekly training hours were more important (43%) than sex (17%), puberty (14%) and bone (15%) in BMC, and puberty (48%) was more important than weekly training hours (19%), sex (12%), and radius-ulna (5%) in BA. The loaded bones % hypertrophy correlated with weekly training hours highly (> 0.60) in all maturity groups for BMC and BA, and moderately (0.41) in early adults for BA; it also correlated with age (≥ 0.60) in children and peripubertal players, but not (0.037) with starting age. Impact loading exercise favors mineralization twice than bone expansion, while puberty favors bone expansion about three times more than mineralization. The bone gains are higher for boys than girls, and for peripubertal than older players. The bone growth implications are discussed considering limitations and future research.

Study on the Bioactivity Response of the Newly Developed Zn-Cu-Mn/Mg Alloys for Biodegradable Implant Application

Scaffolds play a crucial role in bone tissue engineering to support the defect area through bone regeneration and defect reconstruction. Promising tissue regeneration without negative repercussions and avoidance of the lifelong presence inside the body make bioresorbable metals prosper in the field of regenerative medicine. Recently, Zn and its alloys have emerged as promising biodegradable materials for their moderate degradation rate and satisfactory biocompatibility. Nevertheless, it is very challenging for cells to adhere and grow over the Zn surface alone, which influences the tissue-implant integration. In this study, an attempt has been made to systematically investigate the bioactivity responses in terms of in vitro hemocompatibility, cytotoxicity, antibacterial activity, and in vivo biocompatibility of newly developed Zn-2Cu-0.5Mn/Mg alloy scaffolds with different surface roughness. The rough surface of Zn-2Cu-0.5Mg shows the highest degradation rate of 0.16 mm/yr. The rough surface exhibits a prominent role in the adsorption of protein, further enhancing cell adhesion. Concentration-dependent alloy extract shows the highest cell proliferation for 12.5% of the extract with a maximum cell viability of 101% in Zn-2Cu-0.5Mn and 108% in Zn-2Cu-0.5Mg after 3 d. Acceptable hemolysis percentages (less than 5%) with promising anticoagulation properties are observed for all of the conditions. Enhanced antibacterial (Staphylococcus aureus and Escherichia coli) activity due to a significant effect of ions illustrates the maximum killing effect on the bacterial colony for the rough Zn-2Cu-0.5Mg alloy. In addition, it is observed that for rough Zn-2Cu-0.5Mn/Mg alloys, the inflammatory response is minimal after subcutaneous implantation, and neo-bone tissue forms in the defect areas of the rat femur with satisfactory biosafety response. The osseointegration property of the Zn-2Cu-0.5Mg alloy is comparable to that of the Zn-2Cu-0.5Mn alloy. Therefore, the rough surface of the Zn-2Cu-0.5Mg alloy has the potential to enhance biocompatibility and promote better osseointegration activity with host tissues for various biomedical applications.

The ontogeny of human fetal trabecular bone architecture occurs in a limb-specific manner

Gestational growth and development of bone is an understudied process compared to soft tissues and has implications for lifelong health. This study investigated growth and development of human fetal limb bone trabecular architecture using 3D digital histomorphometry of microcomputed tomography data from the femora and humeri of 35 skeletons (17 female and 18 male) with gestational ages between 4 and 9 months. Ontogenetic data revealed: (i) fetal trabecular architecture is similar between sexes; (ii) the proximal femoral metaphysis is physically larger, with thicker trabeculae and greater bone volume fraction relative to the humerus, but other aspects of trabecular architecture are similar between the bones; (iii) between 4 and 9 months gestation there is no apparent sexual or limb dimorphism in patterns of growth, but the size of the humerus and femur diverges early in development. Additionally, both bones exhibit significant increases in mean trabecular thickness (and for the femur alone, bone volume fraction) but minimal trabecular reorganisation (i.e., no significant changes in degree of anisotropy, connectivity density, or fractal dimension). Overall, these data suggest that in contrast to data from the axial skeleton, prenatal growth of long bones in the limbs is characterised by size increase, without major reorganizational changes in trabecular architecture.

Caffeine and Purine Derivatives: A Comprehensive Review on the Chemistry, Biosynthetic Pathways, Synthesis-Related Reactions, Biomedical Prospectives and Clinical Applications

Caffeine and purine derivatives represent interesting chemical moieties, which show various biological activities. Caffeine is an alkaloid that belongs to the family of methylxanthine alkaloids and it is present in food, beverages, and drugs. Coffee, tea, and some other beverages are a major source of caffeine in the human diet. Caffeine can be extracted from tea or coffee using hot water with dichloromethane or chloroform and the leftover is known as decaffeinated coffee or tea. Caffeine and its derivatives were synthesized via different procedures on small and large scales. It competitively antagonizes the adenosine receptors (ARs), which are G protein-coupled receptors largely distributed in the human body, including the heart, vessels, brain, and kidneys. Recently, many reports showed the effect of caffeine derivatives in the treatment of many diseases such as Alzheimer's, asthma, parkinsonism, and cancer. Also, it is used as an antioxidant, anti-inflammatory, analgesic, and hypocholesterolemic agent. The present review article discusses the synthesis, reactivity, and biological and pharmacological properties of caffeine and its derivatives. The biosynthesis and biotransformation of caffeine in coffee and tea leaves and the human body were summarized in the review.

Inter-arm bone mass and size asymmetries in children tennis players are maturity status specific: a 9-month study on the effects of training time across pubertal change and somatic growth

PURPOSE

Bone growth with exercise is best assessed by tennis-induced inter-arm asymmetries. Yet, the effects of training and maturation across puberty were unclear. This study explored arm bone growth across 9 months of training in 46 tennis players 7-14 years (25 boys, 21 girls).

METHODS

Bone mineral content (BMC) and bone area (BA) were measured from DXA scans. Pubertal status was assessed by Tanner stage (TS) and somatic growth by maturity offset (MO). Children were grouped as pre- (TS I-I), early (TS I-II), and mid/late pubertal (TS II-III).

RESULTS

Training time (TT) change in the three groups was 160-170, 190-230, and 200-220 h, respectively. Bone asymmetries were large in all groups (d > 0.8, P < 0.001): 5-18 g (9-21%) and 9-17 g (17-23%) in girls and boys, respectively, for BMC, and 5-15 cm2 (6-13%) and 9-15 cm2 (12-15%) in girls and boys (10-13%), respectively, for BA. BMC and BA change asymmetry peaked at pre-puberty in girls (56%, 46%) and at early puberty in boys (57%, 43%). Asymmetry gains varied with baseline asymmetry (41%) and change in TT (38%) and TS (17%) in BMC, and with baseline asymmetry (58%) and change in MO (17%) and TS (12%) in BA.

CONCLUSION

All bone asymmetries were substantial. Tennis-induced bone gains were higher at pre- to early puberty in girls and at early to mid/late puberty in boys. Training enhanced mostly bone mass and maturity status enhanced mostly bone size; sex was not bone-change modeling impactful. Implications are discussed considering certain limitations.

Development of Zn-2Cu-xMn/Mg Alloys for Orthopedic Applications: Mechanical Performance to In Vitro Degradation under Different Physiological Environments

Zinc (Zn) and its alloys are considered futuristic biodegradable materials for their acceptable mechanical properties, suitable corrosion rate, and good biocompatibility. In this study, we report newly developed biodegradable Zn-2Cu-xMn/Mg (x = 0, 0.1, and 0.5) alloys, aiming to achieve good mechanical strength with excellent elongation, desirable wear resistance, and suitable corrosion rate. The effect of Mn/Mg addition on the structural, mechanical, wear, and degradation behaviors of the Zn-2Cu-xMn/Mg alloys was thoroughly investigated. Degradation and tribological behaviors of the alloys were explored in the presence of simulated body fluid (SBF), Dulbecco's modified Eagle medium (DMEM), and DMEM with a 10% fetal bovine serum (FBS) solution. Alloy elements and hot rolling improve their mechanical properties significantly due to precipitation hardening, grain refinement, and solid solution strengthening owing to the formation of MnZn13 and Mg2Zn11 phases. Among all the alloys, the Zn-2Cu-0.5Mn alloy achieved the highest ultimate tensile strength (UTS) of ∼405 MPa and yield strength (YS) of ∼293 MPa with an excellent elongation of ∼51%. The corrosion behavior of the alloys as determined by a potentiodynamic polarization study under different solutions follows the sequence Zn-2Cu < Zn-2Cu-0.5Mn < Zn-2Cu-0.1Mn < Zn-2Cu-0.1Mg < Zn-2Cu-0.5Mg. The corrosion rate by immersion testing for 30 and 90 days also follows the same sequence. The corrosion rate in different solutions follows the order SBF > DMEM + 10%FBS > DMEM. The addition of Mn/Mg also improves the wear resistance and slows the wear rate under wet conditions. The bending test results also indicate the highest bending strength of ∼375 MPa for the Zn-2Cu-0.5Mn alloy, among all the alloys. The bending and tensile strengths deteriorate continuously after the immersion for 30 and 90 days in the solution of SBF, DMEM, and DMEM + 10%FBS. Therefore, the Zn-2Cu-xMn/Mg (x = 0.1 and 0.5) alloys can be considered potential biodegradable implant materials.

Organic Acid-Based Chelate Trace Mineral Supplement Improves Broiler Performance, Bone Composition, Immune Responses, and Blood Parameters

Organic acid-based trace minerals are known to have more bioavailability, possibly due to fewer antagonism reactions in the lumen. A 42-day study was conducted to assess the supplementation of manganese (Mn), zinc (Zn), selenium (Se), iron (Fe), and copper (Cu) from different sources. To that end, a total of 1248-day-old As-hatched Arbor Acres chickens were examined for performance, histology, bone integrity, and plasma biochemical parameters. Experimental groups were as follows: basal diet supplying 50, 75, 100, and 120% of trace mineral requirements using an inorganic trace mineral supplement (ITM50, ITM75, ITM100, ITM120); basal diet supplying 33, 66, and 100% of trace mineral requirements using an organic acid-based trace mineral supplement (OAT33, OAT66, OAT100); plus a basal diet supplying 100% of trace mineral requirements using an amino acid-based chelated trace mineral supplement (ATM100%) as control positive. According to results, birds' fed OAT66 had the highest (P < 0.05) average daily body weight gain (ADG), average daily feed intake (ADFI), and lower feed conversion ratio (FCR). Feeding OAT66 increased (P < 0.05) villus length to crypt depth ratio, compared to OAT33 and ITM100 by 26% and 19%, respectively. The relative weight of the bursa enhanced by 22% in birds' receiving OAT supplement, compared to those received ITM supplement (P < 0.05). The plasma uric acid was reduced by 42% (P < 0.001) in birds fed with OAT66 and OAT100 when compared to those fed ITM50. Overall, our results indicated that the same performance could be achieved by using lower levels of organic trace minerals.

Alkaline earth metals for osteogenic scaffolds: From mechanisms to applications

Regeneration of bone defects is a significant challenge today. As alternative approaches to the autologous bone, scaffold materials have remarkable features in treating bone defects; however, the various properties of current scaffold materials still fall short of expectations. Due to the osteogenic capability of alkaline earth metals, their application in scaffold materials has become an effective approach to improving their properties. Furthermore, numerous studies have shown that combining alkaline earth metals leads to better osteogenic properties than applying them alone. In this review, the physicochemical and physiological characteristics of alkaline earth metals are introduced, mainly focusing on their mechanisms and applications in osteogenesis, especially magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba). Furthermore, this review highlights the possible cross-talk between pathways when alkaline earth metals are combined. Finally, some of the current drawbacks of scaffold materials are enumerated, such as the high corrosion rate of Mg scaffolds and defects in the mechanical properties of Ca scaffolds. Moreover, a brief perspective is also provided regarding future directions in this field. It is worth exploring that whether the levels of alkaline earth metals in newly regenerated bone differs from those in normal bone. The ideal ratio of each element in the bone tissue engineering scaffolds or the optimal concentration of each elemental ion in the created osteogenic environment still needs further exploration. The review not only summarizes the research developments in osteogenesis but also offers a direction for developing new scaffold materials.

Negative calcium balance despite normal plasma ionized calcium concentrations during citrate anticoagulated continuous venovenous hemofiltration (CVVH) in ICU patients

Background

Supplementation of calcium during continuous venovenous hemofiltration (CVVH) with citrate anticoagulation is usually titrated using a target blood ionized calcium concentration. Plasma calcium concentrations may be normal despite substantial calcium loss, by mobilization of calcium from the skeleton. Aim of our study is to develop an equation to calculate CVVH calcium and to retrospectively calculate CVVH calcium balance in a cohort of ICU-patients.

Methods

This is a single-center retrospective observational cohort study. In a subcohort of patients, all calcium excretion measurements in patients treated with citrate CVVH were randomly divided into a development set (n = 324 in 42 patients) and a validation set (n = 441 in 42 different patients). Using mixed linear models, we developed an equation to calculate calcium excretion from routinely available parameters. We retrospectively calculated calcium balance in 788 patients treated with citrate CVVH between 2014 and 2021.

Results

Calcium excretion (mmol/24 h) was − 1.2877 + 0.646*[Ca]blood,total * ultrafiltrate (l/24 h) + 0.107*blood flow (ml/h). The mean error of the estimation was − 1.0 ± 6.7 mmol/24 h, the mean absolute error was 4.8 ± 4.8 mmol/24 h. Calculated calcium excretion was 105.8 ± 19.3 mmol/24 h. Mean daily CVVH calcium balance was − 12.0 ± 20.0 mmol/24 h. Mean cumulative calcium balance ranged from − 3687 to 448 mmol.

Conclusion

During citrate CVVH, calcium balance was negative in most patients, despite supplementation of calcium based on plasma ionized calcium levels. This may contribute to demineralization of the skeleton. We propose that calcium supplementation should be based on both plasma ionized calcium and a simple calculation of calcium excretion by CVVH.

Graphical abstract

A novel hybrid approach to develop bioresorbable material

The need for bioresorbable implants that are able to dissolve within the body is rising, unlike their traditional counterparts. Bulk metallic glasses (BMGs) can perhaps serve this need, since they possess incredible properties, including high biocompatibility by virtue of their amorphous structure and absence of dislocations. However, the fabrication of BMGs is challenging, since, to achieve an amorphous structure, fast cooling is a pre-requisite which is very difficult to achieve for casting due to the fact that fast cooling rate and adequate rate of filling of the mold possess a trade-off relationship. Therefore, purpose of this work is to develop a simple novel hybrid approach that is cost effective and attempts to synthesize BMG based on Mg-Ca-Zn constituent. Synthesis of bioresorbable material was attempted by hybridizing friction stir processing (FSP) technique with gas tungsten arc welding (GTAW). FSP was performed with Magnesium as base material and Calcium granules as reinforcement. After FSP, GTAW process was performed by using Zn as filler material. The added Ca and Zn were found to effectively intermix with the Mg matrix in the FSP and GTAW steps, respectively. Especially, a relatively invariable distribution of Ca phases was observed in the stirred microstructure after FSP. Finally, a wide bead consisting of mixed dendritic and columnar cast structure was obtained. The current work is expected to alleviate the physiological issues pertaining to orthopaedic fixations and decrease the need for secondary surgeries in geriatric fractures.

The Relationship between Dietary Pattern and Bone Mass in School-Age Children

Early bone accrual significantly influences adult bone health and osteoporosis incidence. We aimed to investigate the relationship between dietary patterns (DPs), bone mineral content (BMC) and bone mineral density (BMD) in school-age children in China. Children aged six-nine years (n = 465) were enrolled in this cross-sectional study. DPs were identified by principal component factor analysis. Total body (TB) and total body less head (TBLH) BMC and BMD were measured using dual-energy X-ray absorptiometry. Five DPs were identified. After adjustment for covariates, multiple linear regression analysis showed that the "fruit-milk-eggs" dietary pattern was positively associated with TB (β = 10.480; 95% CI: 2.190, 18.770) and TBLH (β = 5.577; 95% CI: 0.214, 10.941) BMC, the "animal organs-refined cereals" pattern was associated with low TB BMC (β = -10.305; 95% CI: -18.433, -2.176), TBLH BMC (β = -6.346; 95% CI: -11.596, -1.096), TB BMD (β = -0.006; 95% CI: -0.011, -0.001) and TBLH BMD (β = -0.004; 95% CI: -0.007, -0.001). In conclusion, our study recommends home or school meals should be rich in fruit, milk, eggs with a moderate amount of vegetables, coarse grains and meat to promote bone development for school-age children.

Calcium deficiency worldwide: prevalence of inadequate intakes and associated health outcomes

Dietary calcium deficiency is considered to be widespread globally, with published estimates suggesting that approximately half of the world's population has inadequate access to dietary calcium. Calcium is essential for bone health, but inadequate intakes have also been linked to other health outcomes, including pregnancy complications, cancers, and cardiovascular disease. Populations in low- and middle-income countries (LMICs) are at greatest risk of low calcium intakes, although many individuals in high-income countries (HICs) also do not meet recommendations. Paradoxically, many LMICs with lower calcium intakes show lower rates of osteoporotic fracture as compared with HICs, though data are sparse. Calcium intake recommendations vary across agencies and may need to be customized based on other dietary factors, health-related behaviors, or the risk of calcium-related health outcomes. The lack of standard methods to assess the calcium status of an individual or population has challenged efforts to estimate the prevalence of calcium deficiency and the global burden of related adverse health consequences. This paper aims to consolidate available evidence related to the global prevalence of inadequate calcium intakes and associated health outcomes, with the goal of providing a foundation for developing policies and population-level interventions to safely improve calcium intake and status where necessary.

The Abundance of Trace Elements in Human Bone Relative to Bone Type and Bone Pathology

As the global population ages and the proportion of individuals afflicted with musculoskeletal disease spirals upward, there is an increasing interest in understanding and preventing bone-related diseases. Bone diseases, such as osteoporosis and osteoarthritis, are known to be influenced by a variety of factors including age, gender, nutrition, and genetics, but are also inherently linked to the human body's ability to produce biominerals of suitable quality. Because the crystal lattice structure and mineralogy of bone hydroxyapatite is surprisingly analogous to geological hydroxyapatite, trace element levels and exposure have long been proposed to influence the structure of biominerals as they do geological minerals (e.g., strontium substitution changes the crystal lattice of bone minerals, while toxic lead disrupt bone cellular processes leading to bone disease). Here, we explore the distribution of trace elements in human bones to evaluate the distribution of these elements with respect to bone type (cortical vs. trabecular) and bone disease (osteoarthritis vs. osteoporosis). We find higher concentrations of many metabolically active transition metals, as well as lead, in cortical bone compared to trabecular bone. When compared to patients who have osteoarthritis, and thus presumably normal bone minerals, osteoporosis patients have higher concentrations of scandium and chromium (Cr) in trabecular bone, and Cr and lead in cortical bone. Lower concentrations of barium and titanium are associated with osteoporotic trabecular bone. This survey is an exploratory cross-sectional geochemical examination of several trace element concentrations previously understudied in human bone minerals.

Effect of Milling Parameters on Mechanical Properties and In Vitro Biocompatibility of Mg-Zn-Co Ternary Alloy

Magnesium (Mg) is a potential candidate for biomedical implants, but its susceptibility to suffer corrosion attack in human body fluid limits its practical use. Thus, alloying Mg with other metal elements is the most effective strategy to improve its mechanical properties and biocompatibility. Herein, we report a Mg-Zn-Co ternary alloy (85-10-5 wt %) synthesized by the mechanical alloying technique. Ball-milling parameters such as ball size and milling time were varied to obtain better alloy properties. After compaction and sintering, the obtained alloy samples were subjected to various characterizations, including grain, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, X-ray diffraction (XRD), microhardness and nanoindentation analyses. In vitro biocompatibility analysis of different alloys was also performed with MC3T3-E1 osteoblasts. Grain analysis confirmed the even dispersion of particles, while SEM analysis showed the formation of laminates, spherical and fine particles with an increase in time and varied ball size. XRD results further confirmed the formation of intermetallic compounds. The microhardness of samples was increased with the increase in milling time. The Young’s modulus of ternary alloys obtained from nanoindentation analysis was comparable to the modulus of human bone. Moreover, in vitro analysis with osteoblasts showed that the developed alloys were noncytotoxic and biocompatible.

Nutritional Approaches as a Treatment for Impaired Bone Growth and Quality Following the Consumption of Ultra-Processed Food

The severe impairment of bone development and quality was recently described as a new target for unbalanced ultra-processed food (UPF). Here, we describe nutritional approaches to repair this skeletal impairment in rats: supplementation with micro-nutrients and a rescue approach and switching the UPF to balanced nutrition during the growth period. The positive effect of supplementation with multi-vitamins and minerals on bone growth and quality was followed by the formation of mineral deposits on the rats' kidneys and modifications in the expression of genes involved in inflammation and vitamin-D metabolism, demonstrating the cost of supplementation. Short and prolonged rescue improved trabecular parameters but incompletely improved the cortical parameters and the mechanical performance of the femur. Cortical porosity and cartilaginous lesions in the growth-plate were still detected one week after rescue and were reduced to normal levels 3 weeks after rescue. These findings highlight bone as a target for the effect of UPF and emphasize the importance of a balanced diet, especially during growth.

Calcium Absorption from Food Products: Food Matrix Effects

This article reviews physicochemical aspects of calcium absorption from foods. Notable differences are observed between different food products in relation to calcium absorption, which range from <10% to >50% of calcium in the foods. These differences can be related to the interactions of calcium with other food components in the food matrix, which are affected by various factors, including fermentation, and how these are affected by the conditions encountered in the gastrointestinal tract. Calcium absorption in the intestine requires calcium to be in an ionized form. The low pH in the stomach is critical for solubilization and ionization of calcium salts present in foods, although calcium oxalate complexes remain insoluble and thus poorly absorbable. In addition, the rate of gastric transit can strongly affect fractional absorption of calcium and a phased release of calcium into the intestine, resulting in higher absorption levels. Dairy products are the main natural sources of dietary calcium in many diets worldwide, which is attributable to their ability to provide high levels of absorbable calcium in a single serving. For calcium from other food products, lower levels of absorbable calcium can limit contributions to bodily calcium requirements.

Role of nitric oxide in type 1 diabetes-induced osteoporosis

Type 1 diabetes (T1D)-induced osteoporosis is characterized by decreased bone mineral density, bone quality, rate of bone healing, bone formation, and increased bone resorption. Patients with T1D have a 2-7-fold higher risk of osteoporotic fracture. The mechanisms leading to increased risk of osteoporotic fracture in T1D include insulin deficiency, hyperglycemia, insulin resistance, lower insulin-like growth factor-1, hyperglycemia-induced oxidative stress, and inflammation. In addition, a higher probability of falling, kidney dysfunction, weakened vision, and neuropathy indirectly increase the risk of osteoporotic fracture in T1D patients. Decreased nitric oxide (NO) bioavailability contributes to the pathophysiology of T1D-induced osteoporotic fracture. This review discusses the role of NO in osteoblast-mediated bone formation and osteoclast-mediated bone resorption in T1D. In addition, the mechanisms involved in reduced NO bioavailability and activity in type 1 diabetic bones as well as NO-based therapy for T1D-induced osteoporosis are summarized. Available data indicates that lower NO bioavailability in diabetic bones is due to disruption of phosphatidylinositol 3‑kinase/protein kinase B/endothelial NO synthases and NO/cyclic guanosine monophosphate/protein kinase G signaling pathways. Thus, NO bioavailability may be boosted directly or indirectly by NO donors. As NO donors with NO-like effects in the bone, inorganic nitrate and nitrite can potentially be used as novel therapeutic agents for T1D-induced osteoporosis. Inorganic nitrites and nitrates can decrease the risk for osteoporotic fracture probably directly by decreasing osteoclast activity, decreasing fat accumulation in the marrow cavity, increasing osteoblast activity, and increasing bone perfusion or indirectly, by improving hyperglycemia, insulin resistance, and reducing body weight.

Ultra-Processed Food Impairs Bone Quality, Increases Marrow Adiposity and Alters Gut Microbiome in Mice

Ultra processed foods (UPF) consumption is becoming dominant in the global food system, to the point of being the most recent cause of malnutrition. Health outcomes of this diet include obesity and metabolic syndrome; however, its effect on skeletal development has yet to be examined. This project studied the influence of UPF diet on the development and quality of the post-natal skeleton. Young female mice were fed with regular chow diet, UPF diet, UPF diet supplemented with calcium or with multivitamin and mineral complex. Mice fed UPF diet presented unfavorable morphological parameters, evaluated by micro-CT, alongside inferior mechanical performance of the femora, evaluated by three-point bending tests. Growth-plate histology evaluation suggested a modification of the growth pattern. Accumulation of adipose tissue within the bone marrow was significantly higher in the group fed UPF diet. Finally, microbiome 16SrRNA sequencing was used to explore the connection between diets, gut microbial community and skeletal development. Together, we show that consumption of UPF diet during the postnatal developmental period alters the microbiome and has negative outcomes on bone parameters and bone marrow adiposity. Micronutrients improved these phenotypes only partially. Thus, consuming a wholesome diet that contributes to a healthy microbiota is of a great significance in order to achieve healthy skeletal development.

Contribution of purified soybean trypsin inhibitor and exogenous protease to endogenous amino acid losses and mineral digestibility

The primary objective of the current study was to evaluate the impact of trypsin inhibitor (TI) and exogenous protease supplementation on endogenous loss of amino acids (AA) in broiler chickens. A total of 384 Cobb-500 broiler chicks were allocated to 4 nitrogen-free diets, each with 8 replicate cages and 12 birds per replicate. The diets were arranged as a 2 × 2 factorial with factors being dietary TI (0 or 8,000 TIU/g) and exogenous protease (0 or 15,000 PROT/kg). Desired dietary TI concentration was achieved by addition of commercially available, purified soybean TI. There was no effect of TI or exogenous protease or their interaction on growth performance of birds. However, the endogenous loss of nitrogen (N) and all AA increased (P < 0.05) due to dietary TI concentration except for Cys. The increase in endogenous AA due to TI ranged from 17% for Thr to 52.2% for Trp. Exogenous protease had no effect on endogenous loss of N and all AA. There was no effect of TI or exogenous protease or their interaction on the AID of P, however AID of Ca, Fe, Mg, Mn, and Cu was reduced (P < 0.05) due to dietary TI. The AID of Cu (P < 0.01) and K (P < 0.05) improved with exogenous protease supplementation. Significant interactions (P < 0.05) between exogenous protease and TI existed for Zn, Mg, Cu, and Na. The concentration (g/kg DM intake) of crude mucin and sialic acid increased (P < 0.05) with increased dietary TI. Decreased trypsin (P < 0.001) and increased chymotrypsin (P < 0.001) activity in the pancreas were observed as a result of exogenous protease supplementation. In conclusion, the current study showed that TI increases the endogenous loss of AA and reduced the digestibility of minerals in broiler chickens. Furthermore, exogenous protease did not affect endogenous AA flow, irrespective of added purified dietary TI.

Evaluation of the antibacterial properties and in-vitro cell compatibilities of doped copper oxide/hydroxyapatite composites

Mg, Zn and Ce-doped CuO/HA composites were prepared by a two-step sol-gel and hydrothermal process. SEM images showed a spherical appearance of HA and a needle-like morphology for doped CuO. XRD patterns revealed that all doped CuO/HA composites exhibited a hexagonal crystal structure of HA and a monoclinic crystal structure of CuO with no impurities. ICP analysis indicated that with the increase of loading amount of doped CuO, the concentrations of Cu²⁺ ions and doping ions released from composites increased. Moreover, CuO/HA composites exhibit improved antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as compared with HA. When the loading amount of doped CuO in composites increased to 15 wt%, the composites exhibited the best antibacterial activity and complete bacterial growth inhibition effect. Furthermore, the CCK-8 assay revealed that the doped CuO/HA composites are noncytotoxic and can promote the proliferation of osteosarcoma cells. This work highlights the potential of the doped CuO/HA composites with significant antibacterial activity, bioactivity and cell compatibility for potential biomedical applications in dental implants and bone regeneration.

Assessment of Body Composition and Dietary Intake in Nursing-Home Residents: Could Lessons Learned from the COVID-19 Pandemic Be Used to Prevent Future Casualties in Older Individuals?

The population of older adults, especially those living in the nursing homes, is growing. The sedentary lifestyle and possible poor nutrition in nursing homes place residents (NHRs) at risk for body composition impairments, malnutrition, and, subsequently, numerous chronic diseases. The aim of this study was to assess body composition (including body fluids) and dietary intake in NHRs. The association between osteosarcopenic adiposity syndrome (OSA) and its components, osteopenic adiposity (OA), sarcopenic adiposity (SA), and adiposity-only (AD), and specific macro- and micro-nutrients was evaluated as well. The study included 84 participants (82.1% women), aged 65.3-95.2 years. Body composition was assessed with an advanced bioelectrical impedance device BIA-ACC® and dietary intake was assessed via 24-h recall and analyzed using "Nutrition" software. The majority (95%) of participants were overweight with a high body fat and low muscle and bone mass, leading to a high prevalence of OSA (>50%), OA (13%), and AD (26%). There were only a few participants with SA, and they were not analyzed. The highest extracellular water/total body water ratio was observed in the OSA participants, indicating a heightened inflammatory state. Participants in all three body composition categories had a similar nutrient intake, with protein, fiber, omega-3 fatty acids, and almost all micronutrients being far below recommendations. In conclusion, a high prevalence of OSA among NHRs accompanied by a poor dietary intake, could place these residents at a very high risk for COVID-19 infections. Therefore, optimization of body composition and nutritional status should be included along with standard medical care in order to provide better health maintenance, particularly in the COVID-19 era.

Diabetoporosis: Role of nitric oxide

Diabetoporosis, diabetic-related decreased bone quality and quantity, is one of the leading causes of osteoporotic fractures in subjects with type 2 diabetes (T2D). This is associated with lower trabecular and cortical bone quality, lower bone turnover rates, lower rates of bone healing, and abnormal posttranslational modifications of collagen. Decreased nitric oxide (NO) bioavailability has been reported within the bones of T2D patients and can be considered as one of the primary mechanisms by which diabetoporosis is manifested. NO donors increase trabecular and cortical bone quality, increase the rate of bone formation, accelerate the bone healing process, delay osteoporosis, and decrease osteoporotic fractures in T2D patients, suggesting the potential therapeutic implication of NO-based interventions. NO is produced in the osteoblast and osteoclast cells by three isoforms of NO synthase (NOS) enzymes. In this review, the roles of NO in bone remodeling in the normal and diabetic states are discussed. Also, the favorable effects of low physiological levels of NO produced by endothelial NOS (eNOS) versus detrimental effects of high pathological levels of NO produced by inducible NOS (iNOS) in diabetoporosis are summarized. Available data indicates decreased bone NO bioavailability in T2D and decreased expression of eNOS, and increased expression and activity of iNOS. NO donors can be considered novel therapeutic agents in diabetoporosis.

The effect of high-dose, short-term caffeine intake on the renal clearance of calcium, sodium and creatinine in healthy adults

The consumption of caffeine has been linked to osteoporosis, believed to be due to enhanced bone resorption as a result of increased calcium excretion in the urine. However, the amount of calcium in the urine may not necessarily reflect the true effect of caffeine on calcium clearance. This study therefore examined the impact of high-dose, short-term caffeine intake on renal clearance of calcium, sodium and creatinine in healthy adults. In a double-blind clinical study, participants chewed caffeine (n = 12) or placebo (n = 12) gum for 5 minutes at 2-hour intervals over a 6-hour treatment period (800 mg total caffeine). Caffeine increased renal calcium clearance by 77%. Furthermore, the effect was positively correlated with sodium clearance and urine volume, suggesting that caffeine may act through inhibition of sodium reabsorption in the proximal convoluted tubule. This study confirmed that caffeine does increase renal calcium clearance and fosters further investigation into safe consumption of caffeine.

Osteosarcopenic adiposity syndrome update and the role of associated minerals and vitamins

The objectives are to present an updated synopsis on osteosarcopenic adiposity (OSA) syndrome and evaluate the roles of selected micronutrients in its prevention and management. OSA refers to the concurrent deterioration of bone (osteopenia/osteoporosis), muscle (sarcopenia) and adipose tissue expansion. It portrays the most advanced stage in a continuum of body composition disorders. Although OSA has been widely studied involving the populations of different backgrounds, its prevalence is hard to collate because different methodologies and criteria were used for its diagnosis. Another critical health aspect is the presence of low-grade chronic inflammation (LGCI) which contributes to OSA and vice versa. Nutrition is important in the prevention and management of both OSA and LGCI. Although micronutrients act in numerous metabolic and physiological processes, their roles here are presented in relation to OSA (and its components) and LGCI in general and relevant to the COVID-19 pandemic. These include calcium, magnesium, phosphorus, potassium, sodium and vitamins D and K; their interactions, physiological ratios and synergism/antagonism are discussed as well. In conclusion, calcium, magnesium and vitamin D have a profound impact on OSA and its components, and the latter two also on LGCI. Potassium and vitamin K are vital in bone, muscle functioning and possibly adipose tissue modification. Both, but particularly vitamin D, surfaced as important modulators of immune system with application in COVID-19 infections. While both phosphorus and sodium have important roles in bone, muscle and can impact adiposity, due to their abundance in food, their intake should be curbed to prevent possible damaging effects.

[Musculoskeletal laboratory diagnostics in competitive sport]

Hintergrund

Die labordiagnostische Untersuchung stellt eine wichtige Möglichkeit zur Beurteilung und Optimierung der Leistungs- und Regenerationsfähigkeit professioneller Athleten dar. Ferner ist sie für die Prävention, Diagnostik und Rehabilitation von Verletzungen und Überbelastungen von Bedeutung.

Fragestellung

Ziel dieser Arbeit ist die Darstellung muskuloskelettaler laborchemischer Parameter, die relevante Erkenntnisse für die medizinische Betreuung von Leistungssportlern liefern.

Material und Methoden

Literaturrecherche und narratives Review.

Ergebnisse

Die Bestimmung des Vitamin-D-, Calcium- und Knochenstoffwechsels stellt die laborchemische Basisdiagnostik im Rahmen der Beurteilung des Skelettstatus mit zusätzlichem präventivem Nutzen bezüglich muskuloskelettaler Verletzungen dar. Ferner können muskuläre Serummarker, z. B. Laktatdehydrogenase (LDH), Kreatinkinase (CK), Myoglobin und Aspartat-Aminotransferase (ASAT), helfen, eine metabolische Adaptation an das physische Training festzustellen und Aussagen über die muskuläre Arbeitslast und mögliche Schädigungen zu gewinnen. Die Energieverfügbarkeit kann durch eine entsprechende Bilanzierung sowie die laborchemische Bestimmung der Makro- und Mikronährstoffe eingeschätzt und optimiert werden.

Schlussfolgerungen

Die labordiagnostische Untersuchung besitzt in der Betreuung von Athleten eine sportartenübergreifende klinische Relevanz. Sie dient der Erreichung einer höchstmöglichen Leistungsfähigkeit sowie optimalen Prävention von Knochen- und Muskelverletzungen, wobei sämtliche Mangelzustände (z. B. Vitamin D) ausgeglichen werden sollten. Durch eine Periodisierung der laborchemischen Untersuchungen, mit zumindest zwei Labordiagnostiken im Jahr, und Aufstellung individueller Variabilitäts- und Referenzbereiche kann ferner eine bessere Beurteilbarkeit erreicht werden.

Genetic variants and physical activity interact to affect bone density in Hispanic children

Background

Our aim was to investigate if moderate to vigorous physical activity (MVPA), calcium intake interacts with bone mineral density (BMD)-related single nucleotide polymorphisms (SNPs) to influence BMD in 750 Hispanic children (4-19y) of the cross-sectional Viva La Familia Study.

Methods

Physical activity and dietary intake were measured by accelerometers and multiple-pass 24 h dietary recalls, respectively. Total body and lumbar spine BMD were measured by dual energy X-ray absorptiometry. A polygenic risk score (PRS) was computed based on SNPs identified in published literature. Regression analysis was conducted with PRSs, MVPA and calcium intake with total body and lumbar spine BMD.

Results

We found evidence of statistically significant interaction effects between the PRS and MVPA on total body BMD and lumbar spine BMD (p < 0.05). Higher PRS was associated with a lower total body BMD (β = − 0.040 ± 0.009, p = 1.1 × 10^− 5) and lumbar spine BMD (β = − 0.042 ± 0.013, p = 0.0016) in low MVPA group, as compared to high MVPA group (β = − 0.015 ± 0.006, p = 0.02; β = 0.008 ± 0.01, p = 0.4, respectively).

Discussion

The study indicated that calcium intake does not modify the relationship between genetic variants and BMD, while it implied physical activity interacts with genetic variants to affect BMD in Hispanic children. Due to limited sample size of our study, future research on gene by environment interaction on bone health and functional studies to provide biological insights are needed.

Conclusions

Bone health in Hispanic children with high genetic risk for low BMD is benefitted more by MVPA than children with low genetic risk. Our results may be useful to predict disease risk and tailor dietary and physical activity advice delivery to people, especially children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02537-y.

Quantitative laser-induced breakdown spectroscopy for discriminating neoplastic tissues from non-neoplastic ones

In this paper, we present a method to distinguish neoplastic tissues from non-neoplastic ones using calibration-free laser-induced breakdown spectroscopy (CF-LIBS). For this propose, plasma emission was collected from neoplastic and non-neoplastic tissues taken from the ovarian cancer mice models. Results were obtained by utilizing the characteristic plasma emission lines of different elements that have been confirmed in the investigated samples. From the temporal evolution of plasma emission, the optimum temporal-observation-windows are identified for LIBS investigation. The concentrations of the detected elements in tissues were measured by a calibration-free approach based on data process of plasma parameters at the local thermodynamic equilibrium. The neoplastic specimens provided more energetic plasma than non-neoplastic ones that resulting in higher peaks intensities, electron density and electron temperature especially in the early windows (between 0.1 µs to 0.8 µs). Results demonstrated higher concentrations of major and trace elements such as Mg, Fe, Ca, Na, and K in the neoplastic tissues. Finally, the results using CF-LIBS method were found to be in good agreement with that of Inductive coupled plasma-optical emission spectroscopy (ICP-OES).

Structural characterization of calcium-binding sunflower seed and peanut peptides and enhanced calcium transport by calcium complexes in Caco-2 cells

BACKGROUND

Peptide-Ca complexes can promote Ca absorption. The present study aimed to determine the transport mechanism and structural characteristics of sunflower seed and peanut peptides with high Ca binding capacity with respect to developing third-generation Ca supplements and functional food ingredients.

RESULTS

High Ca-binding fractions of 1-3 kDa sunflower seed peptide (SSP4 ) and ≥ 10 kDa peanut peptide (PP1 ) had higher amount of Ca transported than CaCl2 and two hydrolyzed proteins in Caco-2 cells. SSP4 and PP1 were separated by Ca ion metal chelate affinity chromatography, and high Ca-binding fractions were observed for SSP4 -P2 and PP1 -P2 . The amino acid sequences of SSP4 -P2 and PP1 -P2 were characterized by high-performance liquid chromatography-electrospray ionization-time of flight mass spectrometry. Seven and eight peptides were identified from SSP4 -P2 and PP1 -P2 , respectively. These peptides had molecular weights ranging from 1500 Da to 2500 Da and a large number of characteristic amino acid sequences, such as EEEQQQ, EQ-QQQ-QQ, QQ-QQQQQ, E-EEE, EE-EEQ, RR, Q-QQ-QQQ, EE-EQ-EE-Q, QQ-QQQQ, and Q-QQQQ, where 'E' is glutamic acid and 'Q' is glutamine.

CONCLUSION

SSP4 and PP1 can promote Ca transport in Caco-2 cells without affecting cell permeability. The amino acid sequences of SSP4 -P2 and PP1 -P2 with high Ca-binding abilities contain characteristic sequences, such as continuous glutamic acid and glutamine, and have low molecular weights. © 2020 Society of Chemical Industry.

Nutritional and Behavioral Approaches to Body Composition and Low-Grade Chronic Inflammation Management for Older Adults in the Ordinary and COVID-19 Times

As more insight is gained into personalized health care, the importance of personalized nutritional and behavioral approaches is even more relevant in the COVID-19 era, in addition to the need for further elucidation regarding several diseases/conditions. One of these concerning body composition (in this context; bone, lean and adipose tissue) is osteosarcopenic adiposity (OSA) syndrome. OSA occurs most often with aging, but also in cases of some chronic diseases and is exacerbated with the presence of low-grade chronic inflammation (LGCI). OSA has been associated with poor nutrition, metabolic disorders and diminished functional abilities. This paper addresses various influences on OSA and LGCI, as well as their mutual action on each other, and provides nutritional and behavioral approaches which could be personalized to help with either preventing or managing OSA and LGCI in general, and specifically in the time of the COVID-19 pandemic. Addressed in more detail are nutritional recommendations for and roles of macro- and micronutrients and bioactive food components; the microbiome; and optimal physical activity regimens. Other issues, such as food insecurity and nutritional inadequacy, circadian misalignment and shift workers are addressed as well. Since there is still a lack of longer-term primary studies in COVID-19 patients (either acute or recovered) and interventions for OSA improvement, this discussion is based on the existing knowledge, scientific hypotheses and observations derived from similar conditions or studies just being published at the time of this writing.

Phosvitin Derived Phospho-Peptides Show Better Osteogenic Potential than Intact Phosvitin in MC3T3-E1 Osteoblastic Cells

Phosphorylated proteins from food sources have been investigated as regulators of bone formation with potential benefits in treating osteoporosis. Egg, a cheap and nutritious food, is also the source of various proteins and bioactive peptides with applications in human health. Egg yolk is rich in phosvitin, the most phosphorylated protein in nature. Phosvitin has been shown to improve bone health in experimental animals, although the molecular mechanisms and its specific effects on bone-forming osteoblastic cells are incompletely understood. Previous work in our group has identified pancreatin-generated phosvitin phospho-peptides (PPP) as a potential source for bioactive peptides. Given this background, we examined the roles of both phosvitin and PPP in the function of osteoblastic cells. Our results demonstrated their potential to improve bone health by promoting osteoblast differentiation and proliferation, suppressing osteoclast recruitment and the deposition of extracellular matrix, although PPP appeared to demonstrate superior osteogenic functions compared to phosvitin alone.

Corrosion Resistance of Mg72Zn24Ca4 and Zn87Mg9Ca4 Alloys for Application in Medicine

The aim of this work was to monitor the corrosion rate of the Mg72Zn24Ca4 and Zn87Mg9Ca4 alloys. The purity of the alloying elements was 99.9%. The melt process was carried out in an induction furnace. The melting process took place under the cover of an inert gas (argon). The copper form was flooded by liquid alloy. Then, in order to obtain ribbons, the cast alloy, in rod shape, was re-melted on the melt spinning machine. The corrosion resistance of both alloys has been determined on the basis of the following experiments: measurements of the evolution of OCP (open circuit potential), LSV (linear sweep voltamperometry) and EIS (electrochemical impedance spectroscopy). All corrosion tests were carried out in Ringer's solution at 37 °C and pH 7.2. The corrosion tests have revealed that the zinc alloy, Zn87Mg9Ca4, exhibits significantly higher corrosion resistance in the Ringer solution compared to the magnesium alloy, Mg72Zn24Ca4. Moreover, it has been shown that the cathodic reaction proceeds faster on the surface of ribbons. EIS measurements show that the dissolution of Mg alloy proceeds with two steps: transfer of Mg2+ ions to the Ringer solution and then the formation of the corrosion products, which are deposited on the surface of magnesium alloy. It has been revealed, too, that for both bulk materials, diffusion of chloride ions through the corrosion product's layer takes place.

The Effect of the Supplementation of a Diet Low in Calcium and Phosphorus with Either Sheep Milk or Cow Milk on the Physical and Mechanical Characteristics of Bone using A Rat Model

This study assessed the effect of cow milk (CM) and sheep milk (SM) consumption on the micro-structure, mechanical function, and mineral composition of rat femora in a male weanling rat model. Male weanling rats were fed a basal diet with a 50% reduction in calcium and phosphorus content (low Ca/P-diet) supplemented with either SM or CM. Rats were fed for 28 days, after which the femora were harvested and stored. The femora were analyzed by μ-CT, three-point bending, and inductively coupled plasma-mass spectrometry (ICP-MS). The addition of either milk to the low Ca/P-diet significantly increased (p < 0.05) trabecular bone volume, trabecular bone surface density, trabecular number, cortical bone volume, and maximum force, when compared to rats that consumed only the low Ca/P-diet. The consumption of either milk resulted in a significant decrease (p < 0.05) in trabecular pattern factor, and cortical bone surface to volume ratio when compared to rats that consumed only the low Ca/P-diet. The results were achieved with a lower consumption of SM compared to that of CM (p < 0.05). This work indicates that SM and CM can help overcome the effects on bone of a restriction in calcium and phosphorus intake.

Vitamin C Deficiency and the Risk of Osteoporosis in Patients with an Inflammatory Bowel Disease

Recent research studies have shown that vitamin C (ascorbic acid) may affect bone mineral density and that a deficiency of ascorbic acid leads to the development of osteoporosis. Patients suffering from an inflammatory bowel disease are at a risk of low bone mineral density. It is vital to notice that patients with Crohn’s disease and ulcerative colitis also are at risk of vitamin C deficiency which is due to factors such as reduced consumption of fresh vegetables and fruits, i.e., the main sources of ascorbic acid. Additionally, some patients follow diets which may provide an insufficient amount of vitamin C. Moreover, serum vitamin C level also is dependent on genetic factors, such as SLC23A1 and SLC23A2 genes, encoding sodium-dependent vitamin C transporters and GSTM1, GSTP1 and GSTT1 genes which encode glutathione S-transferases. Furthermore, ascorbic acid may modify the composition of gut microbiota which plays a role in the pathogenesis of an inflammatory bowel disease.

Mg-Based Metallic Glass-Polymer Composites: Investigation of Structure, Thermal Properties, and Biocompatibility

In this work, the biomedical applicability and physical properties of magnesium-based metallic glass/polycaprolactone (PCL) composites are explored. The composites were fabricated via mechanical alloying and subsequent coextrusion. The coextrusion process was carried out at a temperature near to the supercooled liquid region of the metallic glass and the viscous region of the polymer. The structures, as well as thermal and mechanical properties of the obtained samples were characterized, and in vivo investigations were undertaken. The composite samples possess acceptable thermal and mechanical properties. Tensile tests indicate the ability of the composites to withstand more than 100% deformation. In vivo studies reveal that the composites are biologically compatible and could be promising for biomedical applications.

Effects of post exercise protein supplementation on markers of bone turnover in adolescent swimmers

BACKGROUND

This study examined the effects of whey protein supplementation, compared with an isocaloric carbohydrate beverage and water, consumed immediately following an intense swimming trial on bone turnover in adolescent swimmers.

METHODS

Fifty-eight (31 female, 27 male) swimmers (14.1 ± 0.4 years) were stratified into three groups matched for age, sex and body mass. The protein and carbohydrate groups consumed two isocaloric post-exercise beverages each containing 0.3 g.kg- 1 of whey protein (with ~ 6 mg of calcium) or maltodextrin while the control group consumed water. Participants provided a morning, fasted, resting blood sample, then performed an intense swimming trial consisting of a maximal 200 m swim followed by a high intensity interval swimming protocol (5x100m, 5x50m and 5x25m; 1:1 work-to-rest ratio). Following swimming, they consumed their first respective post-exercise beverage, and 2 h later, they performed a second maximal swim immediately followed by the second beverage. Approximately 3 h after the second beverage, two post-consumption blood samples were collected at 8 h and 24 h from baseline. Procollagen type 1 intact N-terminal propeptide (PINP) and carboxy-terminal collagen crosslinks (CTXI) were measured in serum. The multiples of medians of PINP and CTXI were also used to calculate bone turnover rate and balance.

RESULTS

No significant changes were observed in PINP. CTXI increased (+ 11%) at 8 h in all groups, but then significantly decreased (- 22%) at 24 h in the protein group only. The protein group also had a significantly higher calculated rate of bone turnover at 8 h and 24 h compared to baseline, which was not observed in the other groups.

CONCLUSIONS

These results shed light on the potential importance of protein consumed shortly after intense swimming in promoting positive bone turnover responses up to 24 h following exercise in adolescent athletes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov PRS; NCT04114045. Registered 1 October 2019 - Retrospectively registered.

Zehetbauer M, Orlov D. Surface Analysis of Biodegradable Mg-Alloys after Immersion in Simulated Body Fluid

Two binary biodegradable Mg-alloys and one ternary biodegradable Mg-alloy (Mg-0.3Ca, Mg-5Zn and Mg-5Zn-0.3Ca, all in wt%) were investigated. Surface-sensitive X-ray photoelectron spectroscopy analyses (XPS) of the alloy surfaces before and after immersion in simulated body fluid (SBF) were performed. The XPS analysis of the samples before the immersion in SBF revealed that the top layer of the alloy might have a non-homogeneous composition relative to the bulk. Degradation during the SBF immersion testing was monitored by measuring the evolution of H2. It was possible to evaluate the thickness of the sample degradation layers after the SBF immersion based on scanning electron microscopy (SEM) of the tilted sample. The thickness was in the order of 10-100 µm. The typical bio-corrosion products of all of the investigated alloys consisted of Mg, Ca, P and O, which suggests the formation of apatite (calcium phosphate hydroxide), magnesium hydrogen phosphate hydrate and magnesium hydroxide. The bioapplicability of the analyzed alloys with regard to surface composition and degradation kinetics is discussed.

A biodegradable Zn-1Cu-0.1Ti alloy with antibacterial properties for orthopedic applications

Zinc (Zn) alloys are receiving increasing attention in the field of biodegradable implant materials due to their unique combination of suitable biodegradability and good biological functionalities. However, the currently existing industrial Zn alloys are not necessarily biocompatible, nor sufficiently mechanically strong and wear-resistant. In this study, a Zn-1Cu-0.1Ti alloy is developed with enhanced mechanical strength, corrosion wear property, biocompatibility, and antibacterial ability for biodegradable implant material applications. HR and HR + CR were performed on the as-cast alloy and its microstructure, mechanical properties, frictional and wear behaviors, corrosion resistance, in vitro cytocompatibility, and antibacterial ability were systematically assessed. The microstructures of the Zn-1Cu-0.1Ti alloy after different deformation conditions included a η-Zn phase, a ε-CuZn₅ phase, and an intermetallic phase of TiZn₁₆. The HR+CR sample of Zn-1Cu-0.1Ti exhibited a yield strength of 204.2 MPa, an ultimate tensile strength of 249.9 MPa, and an elongation of 75.2%; significantly higher than those of the HR alloy and the AC alloy. The degradation rate in Hanks' solution was 0.029 mm/y for the AC alloy, 0.032 mm/y for the HR+CR alloy, and 0.034 mm/y for the HR alloy. The HR Zn-1Cu-0.1Ti alloy showed the best wear resistance, followed by the AC alloy and the alloy after HR + CR. The extract of the AC Zn-1Cu-0.1Ti alloy showed over 80% cell viability with MC3T3-E1 pre-osteoblast and MG-63 osteosarcoma cells at a concentration of ≤ 25%. The as-cast Zn-1Cu-0.1Ti alloy showed good blood compatibility and antibacterial ability. STATEMENT OF SIGNIFICANCE: This work repots a Zn-1Cu-0.1Ti alloy with enhanced mechanical strength, corrosion wear property, biocompatibility, and antibacterial ability for biodegradable implant applications. Our findings showed that Zn-1Cu-0.1Ti after hot-rolling plus cold-rolling exhibited a yield strength of 204.2 MPa, an ultimate tensile strength of 249.9 MPa, an elongation of 75.2%, and a degradation rate of 0.032 mm/y in Hanks' Solution. The hot-rolled Zn-1Cu-0.1Ti showed the best wear resistance. The extract of the as-cast alloy at a concentration of ≤ 25% showed over 80% cell viability with MC3T3-E1 and MG-63 cells. The Zn-1Cu-0.1Ti alloy showed good hemocompatibility and antibacterial ability.

Regional drinking water composition effects on hip fracture risk: a spatial analysis of nationwide hospital admissions in Portugal, from 2000 to 2010

Abstract Geographical variation on hip fractures (HF) may be related to the geographical variation of drinking water composition (DWC); minerals in drinking water may contribute to its fragility. We aim to investigate the effects of DWC on HF risk in Portugal (2000-2010). From National Hospital Discharge Register we selected admissions of patients aged ≥50 years, diagnosed with HF caused by low/moderate energy traumas. Water components and characteristics were selected at the municipality level. A spatial generalized additive model with a negative binomial distribution as a link function was used to estimate the association of HF with variations in DWC. There were 96,905HF (77.3% in women). The spatial pattern of HF risk was attenuated after being adjusted for water parameters. Results show an indirect association between calcium, magnesium, and iron and HF risk but no clear relation between aluminum, cadmium, fluoride, manganese, or color and HF risk. Regarding pH, the 6.7pH and 7pH interval seems to pose a lower risk. Different dose-response relationships were identified. The increase of calcium, magnesium, and iron values in DWC seems to reduce regional HF risk. Long-term exposure to water parameters, even within the regulatory limits, might increase the regional HF risk.

Assessment of Toxicity and Therapeutic Effects of Goose Bone in a Rat Model

Goose bone is traditionally used in the treatment of many ailments including in bone fracture. The aim of the present study was to evaluate the subacute toxicity of goose bone in a rat model by investigating some hematological and biochemical parameters in rats. Subsequently, a histopathological study was performed to confirm the presence of pathological lesions in the rat’s vital organs including the liver, kidney, heart, brain, pancreas, lung, spleen, and stomach. Adult Wistar rats were divided into four groups (n = 8) and were orally administrated with three doses (30, 60, and 120 mg/kg) of goose bone once daily for 21 days as compared to control animals (received only drinking water). Goose bone did not cause any significant changes on body weight, relative organ weight, and percentage water content at any of the administered doses. There were also no significant alterations in hematological parameters seen. All three doses administered significantly reduced the triglyceride levels as well as the atherogenic index of plasma (AIP). Animals treated with 120 mg/kg doses had significantly reduced alkaline phosphatase (ALP) activity as compared to the control group. There was no significant alteration on other serum biochemical parameters seen. Additionally, histopathological findings confirmed that there was no inflammatory, necrotic, or other toxicological feature seen for all three doses. It is concluded that goose bone is nontoxic and is safe for consumption besides having the potential to be investigated for the treatment of high triglycerides or liver-related disorder.

Septal Aperture of the Humerus: Etiology and Frequency Rates in Two European Populations

Analysis of the septal aperture was conducted on two documented European populations. Collections from the National Museum of Natural History Lisbon, Portugal, and University of Athens, Greece, were used for the study. Both collections are modern and documented for sex and age. The Portuguese sample comprises 297 individuals (149 males and 148 females) between the ages of 18 and 88. A septal aperture was observed in 50 individuals resulting in a frequency of 16.83%. The Greek sample comprises 117 individuals (68 males and 49 females) between the ages of 20 and 65. Twenty-five septal apertures were observed, giving a frequency of 21.37%. Both populations had high frequencies which exceeded those observed in European countries in previous studies. Sex analysis shows that both samples confirm that septal apertures are more common in females. The Portuguese sample also supports that septal apertures are more common in the left humerus; however, the Greek sample had a higher frequency of bilateral cases. Measurements of the Portuguese sample were taken to determine whether robusticity correlates with presence of septal apertures. These measurements concluded that there was no difference in robusticity with presence or absence of a septal aperture, challenging previous studies. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1821-1830, 2020. © 2019 American Association for Anatomy.

UHPLC assisted simultaneous separation of apigenin and prednisolone and its application in the pharmacokinetics of apigenin

A new ultra-high performance liquid chromatography-mass spectrometry-mass spectrometry (UHPLC-MS/MS) system has been formulated for the resolution of closely related drugs apigenin (API, a bioflavinoid) and prednisolone (PRD) from their mixture. This developed method comprised of a "BEH™ C18 column (50 mm × 2.1 mm, 1.7 μm)" using acetonitrile and 0.1% formic acid (35:65 v/v) at a supply rate of 0.25 mL·min-1 as eluent. It was found that selected eluent provided short run time (≤2.5 min) as well as better peak symmetry. Satisfactory values of chromatographic parameters such as resolution (Rs = 2.5), capacity factor (k; 13.6 and 23.4 for API and PRD respectively, selectivity (α = 1.72) and number of theoretical plates (N; 3789 and 42,435 for API and PRD respectively) indicate the efficiency of the developed method. The obtained separation was then exploited for the detection and measurement of API in rat plasma sample by means of PRD as an "internal standard" (IS). The eluted compounds in plasma were identified by tandem mass spectrometry by means of tandem quadrupole (TQ) detector ("Waters Corp., Milford, MA") fortified with an "electrospray ionisation (ESI)" source functioning in positive ionization mode. The determination of API in plasma was accomplished by means of "multiple reactions monitoring (MRM)" mode. Assortment of "ionization pairs" (m/z) was displayed in the following manner: API: 270.99 → 152.9 ("cone voltage" 57 V, "collision energy" 34 V), PRD: 403.172 → 385.224 ("cone voltage" 42 V, "collision energy" 13 V). The calibration curves followed linearity in concentration range of 05-1000 ng mL-1 with limit of detection "LOD" and limit of quantification "LOQ" of 7.30 and 22.77 ng mL-1, respectively. The developed method was validated taking into consideration various test conditions and satisfactory values of various parameters such as linearity (r2 ± SD = 0.9995 ± 0.0005), interday accuracy (88-120%), interday precision % RSD = 3.30-13.65% whereas intraday accuracy (91-118%) intraday precision % RSD = 1.18-5.83) indicated its validity. The validation outcomes fulfilled the standards of united states food and drug administration "USFDA" in addition Scientific Working Group for Forensic Toxicology "SWGTOX" guiding principles and were not beyond the tolerable constraint. The process developed in plasma was efficaciously harnessed in the pharmacokinetic investigation of various formulations of API after oral administration in rats.

Vitamin C intake in relation to bone mineral density and risk of hip fracture and osteoporosis: a systematic review and meta-analysis of observational studies

We aimed to systematically review available data on the association between vitamin C intake and bone mineral density (BMD), as well as risk of fractures and osteoporosis, and to summarise this information through a meta-analysis. Previous studies on vitamin C intake in relation to BMD and risk of fracture and osteoporosis were selected through searching PubMed, Scopus, ISI Web of Science and Google Scholar databases before February 2017, using MeSH and text words. To pool data, either a fixed-effects model or a random-effects model was used, and for assessing heterogeneity, Cochran's Q and I 2 tests were used. Subgroup analysis was applied to define possible sources of heterogeneity. Greater dietary vitamin C intake was positively associated with BMD at femoral neck (pooled r 0·18; 0·06, 0·30) and lumbar spine (pooled r 0·14; 95 % CI 0·06, 0·22); however, significant between-study heterogeneity was found at femoral neck: I 2=87·6 %, P heterogeneity<0·001. In addition, we found a non-significant association between dietary vitamin C intake and the risk of hip fracture (overall relative risk=0·74; 95 % CI 0·51, 1·08). Significant between-study heterogeneity was found (I 2=79·1 %, P heterogeneity<0·001), and subgroup analysis indicated that study design, sex and age were the main sources of heterogeneity. Greater dietary vitamin C intake was associated with a 33 % lower risk of osteoporosis (overall relative risk=0·67; 95 % CI 0·47, 0·94). Greater dietary vitamin C intake was associated with a lower risk of hip fracture and osteoporosis, as well as higher BMD, at femoral neck and lumbar spine.

Dietary Patterns in Relation to Low Bone Mineral Density and Fracture Risk: A Systematic Review and Meta-Analysis

Low bone mineral density (BMD) and osteoporosis-related fractures constitute a considerable public health burden. Several studies have demonstrated the association between diet and bone health. We performed a systematic review to provide an estimate of the association between different dietary patterns defined through the use of a posteriori methods and fracture or low BMD risk. A literature search on PubMed, Web of Science, and Scopus databases, up to March 2018, was performed to identify all eligible case-control, prospective, or cross-sectional studies involving subjects of both sexes and any age. Random-effects models were used. Heterogeneity and publication bias were evaluated. Stratified analyses were conducted on study characteristics. The meta-analysis includes 20 studies and identifies 3 prevalent dietary patterns: "Healthy," "Milk/dairy," and "Meat/Western." From the 10 studies on fracture, adherence to the "Healthy" pattern reduced the risk, particularly in older people (OR: 0.79; 95% CI: 0.66, 0.95; P = 0.011) and in Eastern countries (OR: 0.64; 95% CI: 0.43, 0.97; P = 0.037), whereas the risk increased with the "Meat/Western" pattern, especially for older people (OR: 1.11; 95% CI: 1.04, 1.18, P = 0.001), in those with hip fractures (OR: 1.15; 95% CI: 1.05, 1.25; P = 0.002), and in Western countries (OR: 1.10; 95% CI: 1.07, 1.14; P < 0.0001). Analyses on low BMD showed a reduced risk in the "Healthy" pattern, particularly for younger people (OR: 0.62; 95% CI: 0.44, 0.89; P = 0.009). The "Meat/Western" pattern increased low BMD risk, especially in older people (OR: 1.31; 95% CI: 1.05, 1.64; P = 0.015). The "Milk/dairy" pattern resulted in the strongest reduction in low BMD risk; when stratifying, this effect remained significant (e.g., older women-OR: 0.57; 95% CI: 0.46, 0.70; P < 0.0001). Nutrition is an important modifiable factor affecting bone health. The "Healthy" and "Milk/dairy" patterns are associated with a reduced risk of low BMD and fracture. In contrast, the "Western" pattern is inversely associated.

Corrosion and bone healing of Mg-Y-Zn-Zr-Ca alloy implants: Comparative in vivo study in a non-immobilized rat femoral fracture model

Biodegradable magnesium (Mg) alloys exhibit improved mechanical properties compared to degradable polymers while degrading in vivo circumventing the complications of permanent metals, obviating the need for surgical removal. This study investigated the safety and efficacy of Mg-Y-Zn-Zr-Ca (WZ42) alloy compared to non-degradable Ti6Al4V over a 14-week follow-up implanted as pins to fix a full osteotomy in rat femurs and as wires wrapped around the outside of the femurs as a cerclage. We used a fully load bearing model allowing implants to intentionally experience realistic loads without immobilization. To assess systemic toxicity, blood cell count and serum biochemical tests were performed. Livers and kidneys were harvested to observe any accumulation of alloying elements. Hard and soft tissues adjacent to the fracture site were also histologically examined. Degradation behavior and bone morphology were determined using micro-computed tomography scans. Corrosion occurred gradually, with degradation seen after two weeks of implantation with points of high stress observed near the fracture site ultimately resulting in WZ42 alloy pin fracture. At 14 weeks however, normal bone healing was observed in femurs fixed with the WZ42 alloy confirmed by the presence of osteoid, osteoblast activity, and new bone formation. Blood testing exhibited no significant changes arising from the WZ42 alloy compared to the two control groups. No recognizable differences in the morphology and more importantly, no accumulation of Mg, Zn, and Ca in the kidney and liver of rats were observed. These load bearing model results collectively taken, thus demonstrate the feasibility for use of the Mg-Y-Zn-Zr-Ca alloy for long bone fracture fixation applications.

Protein and bone health across the lifespan

Bone health is determined by the rate of accrual in early life, followed by the rate of age-associated bone loss. Dietary protein intake might have a role in bone health across both of these phases via pleiotropic mechanistic pathways. Herein we summarise the pathways through which protein may exert either a positive or negative influence on bone. In the introduction, we describe the acid-ash hypothesis, which states that a high-protein intake may lead to an acidic residue that must be neutralised through the leaching of calcium and other minerals from the bone, subsequently leading to demineralisation and bone weakening. Conversely, and as described in the 'Against: mechanisms through which protein may negatively impact bone' section, protein intake may act to strengthen the bone by stimulating the activity of various anabolic hormones and growth factors, or by optimising muscle mass and functionality, which itself has an osteogenic influence. The net effect of these contrasting pathways is described in the 'For: mechanisms through which protein may positively impact bone' section, where a number of meta-analyses have demonstrated that higher protein intakes have a small positive impact on bone mass and fracture risk. Sometimes higher than recommended protein intakes are advised, e.g. during the earlier and later phases of the lifespan or during reduced energy availability. We conclude that protein is an essential nutrient for bone health, although further research is required to clarify the mechanistic pathways through which it exerts its influence, along with the clarification of the quantities, food sources and timing to allow for the optimisation of this protective influence and ultimately a reduction in fracture risk.

The effect of multiple nutrients on plasma parathyroid hormone level in healthy individuals

Although the effect of isolated nutrients on plasma parathyroid hormone (PTH) is somewhat familiar, the effect of multiple nutrients on plasma PTH level has not yet been studied. The aim of this study was to identify groups of food items that are associated with the plasma PTH level in healthy individuals. This cross-sectional study enrolled 1180 healthy individuals from Croatia with plasma PTH levels inside the referent values. A food frequency questionnaire containing 58 food items was completed to evaluate the dietary intake. We used principal component analysis to reduce food items into dietary groups, followed by linear regression analysis to test the association between dietary groups and the level of PTH. The results indicate that different sorts of vegetables (p = .006), sausages, salami, mushrooms, eggs (p = .033), as well as white bread (p = .009) are associated with the increase, while bran bread (p = .009) is associated with the decreased plasma PTH level.

Zinc-based alloys for degradable vascular stent applications

The search for biodegradable metals with mechanical properties equal or higher to those of currently used permanent biomaterials, such as stainless steels, cobalt chromium and titanium alloys, desirable in vivo degradation rate and uniform corrosion is still an open challenge. Magnesium (Mg), iron (Fe) and zinc (Zn)-based alloys have been proposed as biodegradable metals for medical applications. Over the last two decades, extensive research has been done on Mg and Fe. Fe-based alloys show appropriate mechanical properties, but their degradation rate is an order of magnitude below the benchmark value. In comparison, alongside the insufficient mechanical performance of most of its alloys, Mg degradation rate has proven to be too high in a physiological environment and corrosion is rarely uniform. During the last few years, Zn alloys have been explored by the biomedical community as potential materials for bioabsorbable vascular stents due to their tolerable corrosion rates and tunable mechanical properties. This review summarizes recent progress made in developing Zn alloys for vascular stenting application. Novel Zn alloys are discussed regarding their microstructural characteristics, mechanical properties, corrosion behavior and in vivo performance.

STATEMENT OF SIGNIFICANCE

Numerous studies on magnesium and iron materials have been reported to date, in an effort to formulate bioabsorbable stents with tailorable mechanical characteristics and corrosion behavior. Crucial concerns regarding poor ductility and remarkably rapid corrosion of magnesium, and very slow degradation of iron, seem to be still not desirably fulfilled. Zinc was introduced as a potential implant material in 2013 due to its promising biodegradability and biocompatibility. Since then, extensive investigations have been made toward development of zinc alloys that meet clinical benchmarks for vascular scaffolding. This review critically surveys the zinc alloys developed since 2013 from metallurgical and biodegradation points of view. Microstructural features, mechanical, corrosion and in vivo performances of these new alloys are thoroughly reviewed and evaluated.