Phosphate Metabolism in Health and Disease

Natural Polyphenol Delivered Methylprednisolone Achieve Targeted Enrichment for Acute Spinal Cord Injury Therapy

The strong anti-inflammatory effect of methylprednisolone (MP) is a necessary treatment for various severe cases including acute spinal cord injury (SCI). However, concerns have been raised regarding adverse effects from MP, which also severely limits its clinical application. Natural polyphenols, due to their rich phenolic hydroxyl chemical properties, can form dynamic structures without additional modification, achieving targeted enrichment and drug release at the disease lesion, making them a highly promising carrier. Considering the clinical application challenges of MP, a natural polyphenolic platform is employed for targeted and efficient delivery of MP, reducing its systemic side effects. Both in vitro and SCI models demonstrated polyphenols have multiple advantages as carriers for delivering MP: (1) Achieved maximum enrichment at the injured site in 2 h post-administration, which met the desires of early treatment for diseases; (2) Traceless release of MP; (3) Reducing its side effects; (4) Endowed treatment system with new antioxidative properties, which is also an aspect that needs to be addressed for diseases treatment. This study highlighted a promising prospect of the robust delivery system based on natural polyphenols can successfully overcome the barrier of MP treatment, providing the possibility for its widespread clinical application.

Matrix first, minerals later: fine-tuned dietary phosphate increases bone formation in zebrafish

Bone matrix formation and mineralization are two closely related, yet separated processes. Matrix formation occurs first, mineralization is a second step strictly dependent on the dietary intake of calcium and phosphorus (P). However, mineralization is commonly used as diagnostic parameter for bone-related diseases. In this context, bone loss, often characterized as a condition with reduced bone mineral density, represents a major burden for human health, for which increased dietary mineral intake is generally recommended. Using a counterintuitive approach, we use a low-P diet followed by a sufficient-P intake to increase bone volume. We show in zebrafish by histology, qPCR, micro-CT, and enzyme histochemistry that a two-months period of reduced dietary P intake stimulates extensive formation of new bone matrix, associated with the upregulation of key genes required for both bone matrix formation and mineralization. The return to a P-sufficient diet initiates the mineralization of the abundant matrix previously deposited, thus resulting in a striking increase of the mineralized bone volume as proven at the level of the vertebral column, including vertebral bodies and arches. In summary, bone matrix formation is first stimulated with a low-P diet, and its mineralization is later triggered by a sufficient-P dietary intake. In zebrafish, the uncoupling of bone formation and mineralization by alternating low and sufficient dietary P intake significantly increases the bone volume without causing skeletal malformations or ectopic mineralization. A modification of this approach to stimulate bone formation, optimized for mammalian models, can possibly open opportunities to support treatments in patients that suffer from low bone mass.

Association Between the Serum Phosphate Levels and Hospital Mortality as Well as 90-Day Mortality Among Critically Ill Patients with Chronic Obstructive Pulmonary Disease: A Retrospective Cohort Study

Purpose

COPD patients frequently have abnormal serum phosphorus levels. The objective of this study was to examine the correlation between serum phosphorus levels with hospital and 90-day mortality in critically ill patients with COPD.

Patients and Methods

The MIMIC IV database was used for this retrospective cohort analysis. We extracted demographics, vital signs, laboratory tests, comorbidity, antibiotic usage, ventilation and scoring systems within the first 24 hours of ICU admission. Restricted cubic splines and multivariate cox regression analysis models were used to evaluate the connection between serum phosphorus with hospital and 90-day mortality. We assessed and classified various factors including gender, age, renal disease, severe liver disease, the utilization of antibiotics and congestive heart failure.

Results

We included a total of 3611 patients with COPD, with a median age of 70.7 years. After adjusting for all other factors, we observed a significant positive association between serum phosphate levels with both hospital mortality (HR 1.19, 95% CI: 1.07-1.31, p<0.001) and 90-day mortality (HR 1.15, 95% CI: 1.06-1.24, p<0.001). Compared to the medium group (Q2 ≥3.15, <4.0), the adjusted hazard ratios for hospital mortality were 1.47 (95% CI: 1.08-2, p=0.013), and 1.31 (95% CI: 1.06-1.61, p=0.013) for 90-day mortality in the high group (Q3≥4.0). Hospital mortality decreased at serum phosphate levels below 3.8 mg/dl (HR 0.664, 95% CI: 0.468-0.943, p=0.022), but increased for both hospital (HR 1.312, 95% CI: 1.141-1.509, p<0.001) and 90-day mortality (HR 1.236, 95% CI: 1.102-1.386, p<0.001) when levels were above 3.8 mg/dl. Subgroup and sensitivity analyses yielded consistent results.

Conclusion

In critical ill COPD patients, this study demonstrated a non-linear association between serum phosphate levels and both hospital and 90-day mortality. Notably, there was an inflection point at 3.8 mg/dl, indicating a significant shift in outcomes. Future prospective research is necessary to validate this correlation.

Circulating 25-hydroxycholecalciferol and calcium levels, and alkaline phosphatase activity among people living with and without human immunodeficiency virus and injecting drugs in kenya

BACKGROUND

People who inject drugs (PWID) and living with the human immunodeficiency virus (PLHIV) are at higher risk of suffering marked derangements in micronutrient levels, leading to poor disease and treatment outcomes. Consequently, this can be monitored by measuring key biomarkers, such as total circulating (serum) 25-hydroxycholecalciferol (25(OH)D3), calcium, and alkaline phosphatase (ALP) for timely intervention. Therefore, circulating levels of 25(OH)D3 and calcium, and ALP activity were determined in PWID and are highly active anti-retroviral treatment (HAART)-experienced or -naive, along with those without HIV infection.

METHODS

This cross-sectional study compared serum concentrations of 25(OH)D3, calcium, and ALP in Kenyan PLHIV and were HAART-naive (n = 30) or -experienced (n = 61), PWID and without HIV (n = 132).

RESULTS

Circulating 25(OH)D3 levels were significantly different amongst the study groups (P < 0.001), and were significantly lower in the HAART-experienced (median, 17.3; IQR, 18.3 ng/ml; P < 0.001) and -naive participants (median, 21.7; IQR, 12.8 ng/ml; P = 0.015) relative to uninfected (median, 25.6; IQR, 6.8 ng/ml) PWID. In addition, the proportions of vitamin D deficiency (55.7%, 40.0%, and 17.4%) and insufficiency (31.1%, 53.3%, and 63.6%) compared to sufficiency (13.1%, 6.7%, and 18.9%; P < 0.001) were greater amongst HAART-experienced, -naive, and uninfected study groups, respectively. Likewise, serum total calcium concentrations were lower in the HAART-experienced relative to HIV-negative (P = 0.019) individuals. Serum ALP activity was also lower in the HAART-experienced in contrast to HIV-negative PWID (P = 0.048). Regression analysis indicated that predictors of circulating 25(OH)D3 were: age (β = 0.287; R2 = 8.0%; P = 0.017) and serum ALP (β = 0.283; R2 = 6.4%; P = 0.033) in the HAART-experienced PWID, and serum ALP (β = 0.386; R2 = 14.5%; P < 0.001) in the HIV-negative PWID.

CONCLUSION

This study suggests that HIV-1 infection and HAART, including injection substance use, decrease circulating 25(OH)D3, calcium and ALP activity. In addition, age and ALP activity are associated with low circulating vitamin D levels in HAART-experienced PWID. The results highlight the importance of incorporating vitamin D and calcium supplementation in treatment and rehabilitation protocols for PLHIV.

Etiology of hypophosphatemia in adults

Long-term hypophosphatemia, defined by serum phosphorus (P) levels <2.5mg/dL, impairs the development and quality of mineralized tissue of the skeletal, dental, and auditory systems. P homeostasis depends mainly on intestinal absorption and renal excretion. Hypophosphatemia may be due to the redistribution of P to the intracellular space, increased renal losses, or decreased intestinal absorption. Hypophosphatemia can be categorized as acute or chronic, depending on the time course. Most cases, either acute or chronic, are due to acquired causes. However, some chronic cases may have a genetic origin. Accurate and early diagnosis, followed by adequate treatment, is essential to limit its negative effects on the body.

Microplastics alter the microbiota-mediated phosphorus profiles at sediment-water interface: Distinct microbial effects between sediment and plastisphere

Microplastics (MPs) are ubiquitous in freshwater sediments, raising concern about their potential impacts on ecosystem services. However, the specific impacts of microbiota mediated by MPs in sediment and plastisphere compartments on P availability remain elusive. This investigation conducted a series of microcosm experiments utilizing eutrophic lake sediment amended with fuel-based polyethylene terephthalate (PET), bio-based polylactic acid (PLA) MPs, and a natural cobblestone substrate to unravel their effects. The findings highlighted that MPs induced alterations in bacterial communities in both sediment and plastisphere, consequently modifying P availabilities at the sediment-water interface (SWI). In comparison to non-biodegradable PET, biodegradable PLA MPs presented higher proportions of specific bacteria and functional genes associated with P profiles, such as Firmicutes, Ignavibacteriota, and P mineralizing genes in the sediment and plastisphere. This, in turn, elevated the levels of soluble reactive P in the porewater by 54.19 % (0-1 cm), 55.81 % (1-3 cm), and 18.24 % (3-5 cm), respectively. Additionally, PLA obviously altered P immobilization capacity and bioavailability, increasing the organic P fraction. Whereas, inert cobblestone exhibited negligible influence on P biogeochemical processes during the incubation. Moreover, the biofilm communities and those in the surrounding sediment specifically contributed to the changes in P profiles at the SWI. The functional genes associated with P profiles in the sediment mainly concentrate on P mineralization and P uptake/transport. In the plastisphere, P activation genes are obviously affected under MP exposure. This study fills the knowledge gap concerning the repercussions of MPs on ecosystem services.

Resveratrol and Vitamin D: Eclectic Molecules Promoting Mitochondrial Health in Sarcopenia

Sarcopenia refers to the progressive loss and atrophy of skeletal muscle function, often associated with aging or secondary to conditions involving systemic inflammation, oxidative stress, and mitochondrial dysfunction. Recent evidence indicates that skeletal muscle function is not only influenced by physical, environmental, and genetic factors but is also significantly impacted by nutritional deficiencies. Natural compounds with antioxidant properties, such as resveratrol and vitamin D, have shown promise in preventing mitochondrial dysfunction in skeletal muscle cells. These antioxidants can slow down muscle atrophy by regulating mitochondrial functions and neuromuscular junctions. This review provides an overview of the molecular mechanisms leading to skeletal muscle atrophy and summarizes recent advances in using resveratrol and vitamin D supplementation for its prevention and treatment. Understanding these molecular mechanisms and implementing combined interventions can optimize treatment outcomes, ensure muscle function recovery, and improve the quality of life for patients.

Phosphorus balance calculator: an individualized tool for treatment of hyperphosphatemia in hemodialysis patients

BACKGROUND

Lack of evaluations of the dietary phosphorus and dialysis phosphorus removal in daily clinical practice are common obstacles to assessing phosphorus balance and controlling phosphorus in hemodialysis patients. We aimed to investigate whether individualized therapy using a phosphorus balance calculator improves phosphorus control.

METHODS

A randomized, open-label, multicenter, 4-week clinical trial was conducted. A total of 119 maintenance hemodialysis patients aged 18-85 years old and with serum phosphorus level >1.45 mmol/L from three university teaching hospitals in Shanghai were enrolled. Patients were randomized in a 1:1 ratio to individualized therapy (n = 60) or conventional therapy (n = 59). The primary outcome was the serum phosphorus concentration after 4-week treatment. Secondary outcomes included the serum calcium and parathyroid hormone (PTH) concentrations, changes in serum phosphorus, calcium and PTH concentrations, and the proportion of patients achieving target ranges of serum phosphorus, calcium and PTH after 4-week treatment.

RESULTS

Among 119 randomized participants [mean age 62 years; 68 male (57%)], 116 completed the trial. Using the phosphorus balance calculator, the individualized group achieved a better phosphorus balance state and significantly reduced serum phosphorus (1.62 ± 0.45 mmol/L versus 1.85 ± 0.45 mmol/L, P = .006), increased the proportions of patients achieving target serum phosphorus range (41% versus 18%, P = .006) and had greater adjusted mean difference in change in serum phosphorus over the 4 weeks (-0.47 versus -0.23 mmol/L, P = .010) when compared with conventional therapy. No significant changes were observed in serum calcium and PTH levels, the proportion of patients achieving target serum calcium or PTH levels, or the adjusted mean difference of serum calcium and PTH levels over the treatment period.

CONCLUSION

Phosphorus balance calculator was proved to improve serum phosphorus control in patients undergoing maintenance hemodialysis, offering a new tool for managing hyperphosphatemia.

Organic phosphate but not inorganic phosphate regulates Fgf23 expression through MAPK and TGF-ꞵ signaling

One of the main regulators of phosphate homeostasis is fibroblast growth factor 23 (FGF23), secreted by osteocytes. The effects of organic versus inorganic dietary phosphate on this homeostasis are unclear. This study used MC3T3-E1 FGF23-producing cells to examine the transcriptomic responses to these phosphates. Most importantly, the expression and secretion of FGF23 were only increased in response to organic phosphate. Gene ontology terms related to a response to environmental change were only enriched in cells treated with organic phosphate while cells treated with inorganic phosphate were enriched for terms associated with regulation of cellular phosphate metabolism. Inhibition of MAPK signaling diminished the response of Fgf23 to organic phosphate, suggesting it activates FGF23. TGF-β signaling inhibition increased Fgf23 expression after the addition of organic phosphate, while the negative TGF-β regulator Skil decreased this response. In summary, the observed differential response of FGF23-producing to phosphate types may have consequences for phosphate homeostasis.

The role of fibroblast growth factor 23 in regulation of phosphate balance

Phosphate is essential for numerous biological processes, and serum levels are tightly regulated to accomplish these functions. The regulation of serum phosphate in a narrow physiological range is a well-orchestrated process and involves the gastrointestinal (GI) tract, bone, kidneys, and several hormones, namely, parathyroid hormone, fibroblast growth factor 23 (FGF23), and 1,25-dihydroxyvitamin D (1,25 Vitamin D). Although primarily synthesized in the bone, FGF23, an endocrine FGF, acts on the kidney to regulate phosphate and Vitamin D homeostasis by causing phosphaturia and reduced levels of 1,25 Vitamin D. Recent studies have highlighted the complex regulation of FGF23 including transcriptional and post-translational modification and kidney-bone cross talk. Understanding FGF23 biology has led to the identification of novel therapeutic agents to treat diseases that disrupt phosphate metabolism secondary to FGF23. The focus of this review is to provide an overview of phosphate homeostasis, FGF23 biology, and the role of FGF23 in phosphate balance.

Investigation of the Proton-Bound Dimer of Dihydrogen Phosphate and Formate Using Infrared Spectroscopy in Helium Droplets

Understanding the structural and dynamic properties of proton-bound complexes is crucial for elucidating fundamental aspects of chemical reactivity and molecular interactions. In this work, the proton-bound complex between dihydrogen phosphate and formate, and its deuterated counterparts, is investigated using IR action spectroscopy in helium droplets. Contrary to the initial expectation that the stronger phosphoric acid would donate a proton to formate, both experiment and theory show that all exchangeable protons are located in the phosphate moiety. The experimental spectra show good agreement with both scaled harmonic and VPT2 anharmonic calculations, indicating that anharmonic effects are small. Some H-bending modes of the nondeuterated complex are found to be sensitive to the helium environment. In the case of the partially deuterated complexes, the experiments indicate that internal dynamics leads to isomeric interconversion upon IR excitation.

Early manifestation of hypophosphatemic rickets in goslings: a potential role of insufficient muscular adenosine triphosphate in motility impairment of early P-deficient geese

We aimed to determine the onset time of hypophosphatemic rickets and investigate the mechanism of motility impairment through adenosine triphosphate (ATP) production in goslings. Two hundred and sixteen 1-day-old male Jiangnan white geese were randomly divided into 3 groups, with 6 replicates and 12 geese per replicate. Birds were fed on 3 diets: a control diet (nonphytic phosphorus, NPP, 0.38%), a P-deficient diet (PD; NPP, 0.08%), and a high P diet (HP; NPP, 0.80%) for 14 d. Subsequently, all birds were shifted to the control diet for an additional 14 d. The cumulative incidence of lameness increased significantly (P < 0.01) starting on d 4, reaching over 80% on d 7 and 100% on d 12 in the PD group. Drinking and eating frequency decreased from d 4 and d 5, respectively, in the PD group compared to the other groups (most P < 0.01). The PD group exhibited shorter and narrower beaks, higher (worse) curvature scores of the beak and costochondral junctions, swelling caput costae, and dirtier feathers since d 4, in contrast to the control and HP groups (most P < 0.01). The HP had bigger (P < 0.05) beak and sternum sizes than the control groups on d 4 to 11. Leg muscle ATP levels were lower (P < 0.01 or 0.05) on d 4 to 11; in contrast, adenosine diphosphate (d 7-11) was higher in PD compared to the control (P < 0.05). Leg muscle ATP level had positive linear (R2 > 0.40) correlations (r > 0.60) with eating and drinking frequencies on d 7 and 11 (P < 0.01). Bone stiffness, feather cleanliness, and ATP levels recovered (P > 0.05) to the control level, whereas bone size did not recover (P < 0.05) in PD and HP after eating the control diet for 2 wk. The onset time of hypophosphatemic rickets was around 4 d in goslings, and insufficient leg muscle ATP was related to the impaired motility observed in early P-deficient geese.

Obeticholic acid attenuates the intestinal barrier disruption in a rat model of short bowel syndrome

BACKGROUND

Short bowel syndrome (SBS) features nutrients malabsorption and impaired intestinal barrier. Patients with SBS are prone to sepsis, intestinal flora dysbiosis and intestinal failure associated liver disease. Protecting intestinal barrier and preventing complications are potential strategies for SBS treatment. This study aims to investigate the effects of farnesoid X receptor (FXR) agonist, obeticholic acid (OCA), have on intestinal barrier and ecological environment in SBS.

METHODS AND RESULTS

Through testing the small intestine and serum samples of patients with SBS, impaired intestinal barrier was verified, as evidenced by reduced expressions of intestinal tight junction proteins (TJPs), increased levels of apoptosis and epithelial cell damage. The intestinal expressions of FXR and related downstream molecules were decreased in SBS patients. Then, global FXR activator OCA was used to further dissect the potential role of the FXR in a rat model of SBS. Low expressions of FXR-related molecules were observed on the small intestine of SBS rats, along with increased proinflammatory factors and damaged barrier function. Furthermore, SBS rats possessed significantly decreased body weight and elevated death rate. Supplementation with OCA mitigated the damaged intestinal barrier and increased proinflammatory factors in SBS rats, accompanied by activated FXR-related molecules. Using 16S rDNA sequencing, the regulatory role of OCA on gut microbiota in SBS rats was witnessed. LPS stimulation to Caco-2 cells induced apoptosis and overexpression of proinflammatory factors in vitro. OCA incubation of LPS-pretreated Caco-2 cells activated FXR-related molecules, increased the expressions of TJPs, ameliorated apoptosis and inhibited overexpression of proinflammatory factors.

CONCLUSIONS

OCA supplementation could effectively ameliorate the intestinal barrier disruption and inhibit overexpression of proinflammatory factors in a rat model of SBS and LPS-pretreated Caco-2 cells. As a selective activator of FXR, OCA might realize its protective function through FXR activation.

Impact of carbonated beverages on early onset of osteoporosis: A narrative review

Background: Processed and semi-processed foods are getting popular in the diets of the Western population. The Western diet is almost coupled with consuming carbonated beverages, either alcoholic or nonalcoholic. The presence of sugar, caffeine, and alcohol in different carbonated beverages and detrimental dietary patterns are leading causes of obesity, diabetes, and periodontal diseases in the young population. Aims: This article aims to review the impact of carbonated beverages on early onset of osteoporosis. Methods: A nonsystematic literature review searches in PubMed and Google Scholar electronic databases with predefined terms relating to carbonated beverages, caffeine intake, childhood obesity, osteoporosis, and bone softness. Results: Bone diseases significantly increase due to early exposure to caffeine and phosphoric acid in the pubertal period. Musculoskeletal growth is a dynamic and complex process, and bone mass achievement is of great importance in this process. According to the global burden of diseases, bone disorders consist of "6.8% of total disability-adjusted life-years." The consumption of soft drinks and their impact on bone accretion and bone mineral density in the young population is under research in the current literature on osteoporotic disorders. Since bone is a metabolically active tissue, it's in constant reconstruction mode. This process is regulated by genetic, hormonal, nutritional, and physical factors. Any imbalance in one of these processes might lead to mineral deposition and osteoporosis. Conclusion: Habitual intake of carbonated drinks with added sugars and caffeine is associated with increased body weight and bone fragility; stringent regulations are needed for proper education.

Genetic causes of hypophosphatemia

Phosphate is a key component of mineralized tissues and is also part of many organic compounds. Phosphorus homeostasis depends especially upon intestinal absorption, and renal excretion, which are regulated by various hormones, such as PTH, 1,25-dihydroxyvitamin D, and fibroblast growth factor 23. In this review we provide an update of several genetic disorders that affect phosphate transporters through cell membranes or the phosphate-regulating hormones, and, consequently, result in hypophosphatemia.

Role of Nutrition in the Management of Patients with Multiple Endocrine Neoplasia Type 1

Multiple endocrine neoplasia type 1 (MEN1) is a rare syndrome caused by inactivating mutations in the MEN1 tumor suppressor gene. The three main clinical manifestations of MEN1 are primary hyperparathyroidism (PHPT), duodenal-pancreatic neuroendocrine tumors (DP-NETs) and anterior pituitary tumors. Endocrine tumors in patients with MEN1 differ from sporadic tumors because of their younger age at onset, common multiple presentations and the different clinical course. MEN1 is characterized by a complex clinical phenotype; thus, patients should be followed by a multidisciplinary team of experts that includes an endocrinologist, a surgeon, a oncologist, a radiotherapist, and not least, a nutritionist. It is important to remember the fundamental role that diet plays as a primary prevention tool, together with a healthy and active lifestyle in preventing osteoporosis/osteopenia and reducing the risk of developing kidney stones due to hypercalciuria, two frequent clinical complications in MEN1 patients. Is very important for MEN1 patients to have an adequate intake of calcium, vitamin D, magnesium and phosphate to maintain good bone health. The intake of foods containing oxalates must also be kept under control because in combination with calcium they concur to form calcium oxalate crystals, increasing the risk of nephrolithiasis. Another aspect to consider is the management of patients with pancreatic neuroendocrine tumors undergoing major surgical resections of the pancreas that can lead to alterations in digestion and absorption mechanisms due to partial or total reduction in pancreatic enzymes such as amylase, lipase, and protease, resulting in malabsorption and malnutrition. Therefore, the nutritionist's aim should be to devise a dietary plan that takes into consideration each single patient, educating them about a healthy and active lifestyle, and accompanying them through various life stages by implementing strategies that can enhance their quality of life.

Male Lrp5A214V mice maintain high bone mass during dietary calcium restriction by altering the vitamin D endocrine system

Environmental factors and genetic variation individually impact bone. However, it is not clear how these factors interact to influence peak bone mass accrual. Here we tested whether genetically programmed high bone formation driven by missense mutations in the Lrp5 gene (Lrp5A214V) altered the sensitivity of mice to an environment of inadequate dietary calcium (Ca) intake. Weanling male Lrp5A214V mice and wildtype littermates (control) were fed AIN-93G diets with 0.125%, 0.25%, 0.5% (reference, basal), or 1% Ca from weaning until 12 weeks of age (ie, during bone growth). Urinary Ca, serum Ca, Ca regulatory hormones (PTH, 1,25 dihydroxyvitamin D3 (1,25(OH)2D3)), bone parameters (μCT, ash), and renal/intestinal gene expression were analyzed. As expected, low dietary Ca intake negatively impacted bones and Lrp5A214V mice had higher bone mass and ash content. Although bones of Lrp5A214V mice have more matrix to mineralize, their bones were not more susceptible to low dietary Ca intake. In control mice, low dietary Ca intake exerted expected effects on serum Ca (decreased), PTH (increased), and 1,25(OH)2D3 (increased) as well as their downstream actions (ie, reducing urinary Ca, increasing markers of intestinal Ca absorption). In contrast, Lrp5A214V mice had elevated serum Ca with a normal PTH response but a blunted 1,25(OH)2D3 response to low dietary Ca that was reflected in the renal 1,25(OH)2D3 producing/degrading enzymes, Cyp27b1 and Cyp24a1. Despite elevated serum Ca in Lrp5A214V mice, urinary Ca was not elevated. Despite an abnormal serum 1,25(OH)2D3 response to low dietary Ca, intestinal markers of Ca absorption (Trpv6, S100g mRNA) were elevated in Lrp5A214V mice and responded to low Ca intake. Collectively, our data indicate that the Lrp5A214V mutation induces changes in Ca homeostasis that permit mice to retain more Ca and support their high bone mass phenotype.

Potential Drug-Nutrient Interactions of 45 Vitamins, Minerals, Trace Elements, and Associated Dietary Compounds with Acetylsalicylic Acid and Warfarin-A Review of the Literature

In cardiology, acetylsalicylic acid (ASA) and warfarin are among the most commonly used prophylactic therapies against thromboembolic events. Drug-drug interactions are generally well-known. Less known are the drug-nutrient interactions (DNIs), impeding drug absorption and altering micronutritional status. ASA and warfarin might influence the micronutritional status of patients through different mechanisms such as binding or modification of binding properties of ligands, absorption, transport, cellular use or concentration, or excretion. Our article reviews the drug-nutrient interactions that alter micronutritional status. Some of these mechanisms could be investigated with the aim to potentiate the drug effects. DNIs are seen occasionally in ASA and warfarin and could be managed through simple strategies such as risk stratification of DNIs on an individual patient basis; micronutritional status assessment as part of the medical history; extensive use of the drug-interaction probability scale to reference little-known interactions, and application of a personal, predictive, and preventive medical model using omics.

Dual-core-component multiphasic bioceramic granules with selective-area porous structures facilitating bone tissue regeneration and repair

Ca-phosphate/-silicate ceramic granules have been widely studied because their biodegradable fillers can enhance bone defect repair accompanied with bioactive ion release and material degradation; however, it is a challenge to endow bioceramic composites with time-dependent ion release and highly efficient osteogenesis in vivo. Herein, we prepared dual-core-type bioceramic granules with varying chemical compositions beneficial for controlling ion release and stimulating osteogenic capability. Core-shell-structured bioceramic granules (P8-Sr4@Zn3, P8-Sr4@TCP, and P8-Sr4@HAR) composed of 8% P- and 4% Sr-substituting wollastonite (P8, Sr4) dual core components and different shell components, such as 3% Zn-substituting wollastonite (Zn3), β-tricalcium phosphate (β-TCP), and hardystonite (HAR), were prepared by cutting extruded core-shell fibers through dual-core ternary nozzles, followed by high-temperature sintering post-treatment. The experimental results showed that nonstoichiometric wollastonite core components contributed to more biologically active ion release in Tris buffer in vitro, and the sparingly dissolvable shell component readily maintained the granule morphology in vivo; thus, such bioceramic implants can adjust new bone growth and material degradation over time. In particular, bioceramic granules encapsulated by the TCP shell exhibited the most appreciable osteogenic capacity and expected biodegradation, which was mostly favorable for bone repair in critical bone defects. It is reasonable to consider that this new multiphasic bioceramic granule design is versatile for developing next-generation implants for various bone damage repairs.

Exploring microgel adsorption: synthesis, classification, and pollutant removal dynamics

Microgels have gained significant importance for the removal of pollutants owing to their stimulus-responsive behavior, high stability, and reusable capacity. However, despite these advantages, several hurdles need to be overcome to fully maximize their potential as effective adsorbents for eradicating various contaminants from the environment, such as metallic cations, organic compounds, anions, harmful gases, and dyes. Therefore, a critical review on the adsorption of pollutants by microgels is needed. In this regard, this review presents the latest developments in the adsorptive properties of microgels. The synthetic methods, architectural structures, and stimulus-responsive behavior of microgels are explained in detail. In addition, this review explores various factors that directly influence the adsorption of pollutants by microgels, such as pH, feed composition, content of pollutants, content of comonomers, agitation time, temperature, microgel dose, nature of both adsorbates (pollutants) and adsorbents (microgels), nature of the medium, and ionic strength. Various adsorption isotherms are also explored together with the kinetic aspects of the adsorption process to provide a comprehensive understanding.

Overcoming the Low-Stability Bottleneck in the Clinical Translation of Liposomal Pressurized Metered-Dose Inhalers: A Shell Stabilization Strategy Inspired by Biomineralization

Currently, several types of inhalable liposomes have been developed. Among them, liposomal pressurized metered-dose inhalers (pMDIs) have gained much attention due to their cost-effectiveness, patient compliance, and accurate dosages. However, the clinical application of liposomal pMDIs has been hindered by the low stability, i.e., the tendency of the aggregation of the liposome lipid bilayer in hydrophobic propellant medium and brittleness under high mechanical forces. Biomineralization is an evolutionary mechanism that organisms use to resist harsh external environments in nature, providing mechanical support and protection effects. Inspired by such a concept, this paper proposes a shell stabilization strategy (SSS) to solve the problem of the low stability of liposomal pMDIs. Depending on the shell material used, the SSS can be classified into biomineralization (biomineralized using calcium, silicon, manganese, titanium, gadolinium, etc.) biomineralization-like (composite with protein), and layer-by-layer (LbL) assembly (multiple shells structured with diverse materials). This work evaluated the potential of this strategy by reviewing studies on the formation of shells deposited on liposomes or similar structures. It also covered useful synthesis strategies and active molecules/functional groups for modification. We aimed to put forward new insights to promote the stability of liposomal pMDIs and shed some light on the clinical translation of relevant products.

Acquired disorders of phosphaturia: Beyond tumor-induced osteomalacia

Phosphate is an integral part of human cellular structure and function. Though most recognised disorders of phosphaturia are genetic in origin, phosphate loss due to acquired conditions is commonly encountered in clinical practice. Acquired hypophosphatemia is most commonly due to renal phosphate wasting and can produce significant morbidity. It also heralds future kidney damage, and continued exposure can lead to progressive kidney injury and potentially renal failure. These conditions are a diverse group of disorders with common shared mechanisms causing loss of phosphate in the urine. Renal phosphate loss can occur as an isolated entity or as a part of generalised proximal tubular dysfunction, i.e., Fanconi's syndrome. An insight into the pathophysiological mechanisms of acquired phosphaturia can help clinicians monitor their patients better and avoid potential harms.

Effect of early serum phosphate disorder on in-hospital and 28-day mortality in sepsis patients: a retrospective study based on MIMIC-IV database

BACKGROUND

This study aims to assess the influence of early serum phosphate fluctuation on the short-term prognosis of sepsis patients.

METHODS

This retrospective study used the Medical Information Mart for Intensive Care IV database to analyze serum phosphate levels in sepsis patients within 3 days of ICU admission. According to the absolute value of delta serum phosphate (the maximum value minus the minimum value of serum phosphorus measured within three days), the patients were divided into four groups, 0-1.3, 1.4-2.0, 2.1-3.1, and ≥ 3.2 mg/dl. Meanwhile, the direction of delta serum phosphate was compared. With the serum phosphate change group of 0-1.3 mg/dl as the reference group, the relationship between delta serum phosphate and in-hospital mortality and 28-day mortality was analyzed by multivariate Logistics regression analysis.

RESULTS

The study involved 1375 sepsis patients. Serum phosphate changes (0-1.3, 1.4-2.0, 2.1-3.1, and ≥ 3.2 mg/dl) correlated with in-hospital and 28-day mortality variations (p = 0.005, p = 0.008). Much higher serum phosphate fluctuation elevated in-hospital and 28-day mortality. Compared to the 0-1.3 mg/dl change group, adjusted odds ratios (OR) in other groups for in-hospital mortality were 1.25 (0.86-1.81), 1.28 (0.88-1.86), and 1.63 (1.10-2.43), and for 28-day mortality were 1.21 (0.86-1.72), 1.10 (0.77-1.57), and 1.49 (1.03-2.19). Under the trend of increasing serum phosphate, the ORs of in-hospital mortality and 28-day mortality in ≥ 3.2 mg/dl group were 2.52 and 2.01, respectively.

CONCLUSION

In conclude, the delta serum phosphate ≥ 3.2 mg/dl was associated with in-hospital mortality and 28-day mortality in patients with sepsis.

LMS-Based Pediatric Reference Values for Parameters of Phosphate Homeostasis in the HARP Cohort

CONTEXT

The assessment of phosphate homeostasis in children is challenging due to the marked changes in laboratory parameters during growth and development, and the lack of adequate reference values.

OBJECTIVE

To develop Lambda-Mu-Sigma (LMS)-based continuous pediatric reference percentiles for 7 key laboratory parameters of phosphate homeostasis.

METHODS

This cross-sectional, single-center study, the HAnnover Reference values for Pediatrics (HARP) study, included 455 children aged 0.1-18 years (254 boys) from outpatient hospital clinics and a secondary school program. Main outcome measures were LMS-based continuous reference percentiles for serum phosphate, plasma intact fibroblast growth factor 23 (iFGF23), and its cofactor soluble Klotho (sKlotho), tubular maximum phosphate reabsorption per glomerular filtration rate (TmP/GFR), fractional tubular reabsorption of phosphate (TRP), and urinary calcium/creatinine (Ca/Crea) and phosphate/creatinine (Pi/Crea) ratios.

RESULTS

LMS-based percentiles and z-scores were established for 7 key laboratory parameters of phosphate homeostasis, which were all found to be age-dependent. Serum phosphate, TmP/GFR, and sKlotho associated with sex. Serum phosphate, TmP/GFR, and urinary Ca/Crea and Pi/Crea levels were highest in infancy and declined until age 18 years, while phosphate and TmP/GFR values reached adult levels earlier in girls compared to boys. iFGF23 concentrations are highest in infancy and fall to a stable plateau by 4 years of age, while sKlotho peaks during adolescence.

CONCLUSION

This is the first report of LMS-based continuous pediatric reference percentiles for key laboratory parameters of phosphate homeostasis that allow calculation of standardized patient z-scores to facilitate test result interpretation in children and adolescents.

Comparative clinical study of phosphorous necrosis and medical-related osteonecrosis of the jaws

BACKGROUND

Phosphorous necrosis of the jaw (PNJ) exhibits similar clinical and pathological features as medical-related osteonecrosis of the jaw (MRONJ). This study aims at comparing the similarities and differences between PNJ and MRONJ regarding pathological features and to provide a theoretical basis for the clinical diagnosis and management of PNJ.

MATERIAL AND METHODS

A retrospective analysis was conducted to assess clinical differences among 38 PNJ patients and 31 MRONJ patients, who were diagnosed and treated between January 2009 and October 2022. Pathological alterations in bone tissue were evaluated using EDS, H&E, Masson, and TRAP staining on five specimens from both MRONJ and PNJ cases; furthermore, immunohistochemistry was used to determine the expression levels of OPG, RANKL, and Runx2. The mandibular coronoid process was removed from individuals with temporomandibular joint ankylosis to serve as a control.

RESULTS

CBCT imaging demonstrated necrotic bone formation in block, strip, or plaque shapes. EDS analysis showed that the calcium/phosphorus ratio in the bone tissue of PNJ and MRONJ was significantly lower than that of the control group (P < 0.05). Additionally, staining indicated reduced osteoblast counts, disrupted bone trabecular structure, and decreased collagen fiber content in the bone tissues of PNJ and MRONJ. Immunohistochemistry demonstrated that RANKL expression was significantly lower in MRONJ compared to PNJ and control groups (P < 0.05). Conversely, Runx2 expression was significantly higher in PNJ than in MRONJ and control groups (P < 0.05), and there was no significant difference in OPG expression.

CONCLUSION

PNJ and MRONJ demonstrate comparable clinical manifestations and pathological traits, although disparities may exist in their underlying exhibit comparable clinical manifestations, pathological traits, and molecular mechanisms.

Phosphorus Intake and Potential Dietary Influences Examined via 24-Hour Urinary Biomarker Measurements in German Children and Adolescents Over 3 Decades

BACKGROUND

Increases in phosphorus intake have been observed over the past years in adult populations. However, biomarker-based data are lacking on whether or not phosphorus intake also increased in children.

OBJECTIVE

The aim of this study was to examine 24-hour urinary phosphate excretion (PO4-Ex) and diet-related biomarkers potentially influencing phosphorus status in German children and adolescents from 1985 to 2015.

DESIGN

This longitudinal noninvasive biomarker-based cohort study examined 24-hour urine samples from children and adolescents of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study, collected over 3 decades.

PARTICIPANTS/SETTING

Examined individuals (n = 1,057) were healthy participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study, situated in Dortmund, Germany, who had been asked to collect one yearly 24-hour urine sample. Six thousand seven hundred thirty-seven samples collected from participants aged 3 to 17 years between 1985 (baseline) and 2015, were included.

MAIN OUTCOME MEASURES

phosphorus intake was examined biomarker-based by analyzed PO4-Ex in 24-hour urine samples. Whether acid-base status and intakes of protein, salt, and fruits and vegetables, may have relevantly contributed to PO4-Ex levels was assessed by determining 24-hour excretions of net acid, urea-nitrogen, and sodium as well as specific standardized excretions of potassium plus oxalate.

STATISTICAL ANALYSES PERFORMED

Trend analysis over 30 years and potentially influencing diet factors were examined using linear mixed-effect regression models (PROC-MIXED). Adjustments for sex, age, and body surface area were performed.

RESULTS

No change was identifiable for PO4-Ex over the 3 decades; neither in 3 to 8, 9 to 13, nor in 14 to 17 year olds. However, sodium excretion increased (P = .001). PROC-MIXED analysis on intraindividual changes in PO4-Ex revealed direct relationships with net acid excretion, urea-nitrogen, and sodium excretion and an inverse relationship with a biomarker of fruit and vegetable intake.

CONCLUSIONS

Despite a direct relationship between PO4-Ex and a biomarker of industrially processed food consumption; that is, sodium excretion, which showed an increasing time trend, phosphorus intake was found to remain stable over decades in children and adolescents.

Vascular Calcification: A Passive Process That Requires Active Inhibition

The primary cause of worldwide mortality and morbidity stems from complications in the cardiovascular system resulting from accelerated atherosclerosis and arterial stiffening. Frequently, both pathologies are associated with the pathological calcification of cardiovascular structures, present in areas such as cardiac valves or blood vessels (vascular calcification). The accumulation of hydroxyapatite, the predominant form of calcium phosphate crystals, is a distinctive feature of vascular calcification. This phenomenon is commonly observed as a result of aging and is also linked to various diseases such as diabetes, chronic kidney disease, and several genetic disorders. A substantial body of evidence indicates that vascular calcification involves two primary processes: a passive process and an active process. The physicochemical process of hydroxyapatite formation and deposition (a passive process) is influenced significantly by hyperphosphatemia. However, the active synthesis of calcification inhibitors, including proteins and low-molecular-weight inhibitors such as pyrophosphate, is crucial. Excessive calcification occurs when there is a loss of function in enzymes and transporters responsible for extracellular pyrophosphate metabolism. Current in vivo treatments to prevent calcification involve addressing hyperphosphatemia with phosphate binders and implementing strategies to enhance the availability of pyrophosphate.

Calcium-phosphate homeostasis and insulin resistance in men

BACKGROUND AND AIMS

Data on P homeostasis in insulin resistance (IR) are still conflicting. We investigated calcium-phosphate homeostasis parameters in men with/without IR.

METHODS AND RESULTS

177 volunteers (aged 61.62 ± 12.11), whose body mass index (BMI) was 29.97 ± 6.35, were studied. On fasting blood and spot urine samples, we measured serum creatinine, sodium (sNa), potassium (sK), chloride (sCl), calcium (sCa), phosphate (sP), alkaline phosphatase total activity (ALP), glucose, insulin, parathyroid hormone (PTH), 25-hydroxy-vitamin D [25(OH)D], and urinary electrolytes corrected for creatinine (uNa/Cr, uK/Cr, uCl/Cr, uCa/Cr, and uP/Cr). Through the QUICKI index, we separated subjects with (IR+, n = 68) or without (IR-, n = 109) IR, and their parameters were compared. Associations were assessed by age-adjusted partial correlation, whose coefficients were compared by Fisher's transform. IR + had higher sP (3.54 ± 0.65 vs. 3.35 ± 0.47, p = 0.044) and lower uCa/Cr levels (0.073 ± 0.056 vs. 0.095 ± 0.072, p = 0.047) than IR-. BMI correlated with sP (r = 0.21, p < 0.05) and PTH (r = 0.29, p < 0.01). QUICKI negatively correlated with sCa (r = -0.22, p < 0.05) and positively with uCa/Cr (r = 0.21, p < 0.05), in turn correlating with uNa/Cr (r = 0.45, p < 0.001). In both groups, uCa/Cr correlated with eGFR and uNa/Cr (p < 0.05 to p < 0.001). In IR + only, sP correlated with BMI, PTH with insulin, and uP/Cr (p < 0.05 for all). IR+ and IR-coefficients differed (p < 0.05 to p < 0.001) for the correlation of sP with BMI and of PTH with insulin and uP/Cr.

CONCLUSION

The higher sP and lower uCa/Cr levels found in men with IR + suggest that IR could modulate calcium-phosphate homeostasis, likely by affecting their renal handling.

Endocrine FGFs and their signaling in the brain: Relevance for energy homeostasis

Since their discovery in 2000, there has been a continuous expansion of studies investigating the physiology, biochemistry, and pharmacology of endocrine fibroblast growth factors (FGFs). FGF19, FGF21, and FGF23 comprise a subfamily with attributes that distinguish them from typical FGFs, as they can act as hormones and are, therefore, referred to as endocrine FGFs. As they participate in a broad cross-organ endocrine signaling axis, endocrine FGFs are crucial lipidic, glycemic, and energetic metabolism regulators during energy availability fluctuations. They function as powerful metabolic signals in physiological responses induced by metabolic diseases, like type 2 diabetes and obesity. Pharmacologically, FGF19 and FGF21 cause body weight loss and ameliorate glucose homeostasis and energy expenditure in rodents and humans. In contrast, FGF23 expression in mice and humans has been linked with insulin resistance and obesity. Here, we discuss emerging concepts in endocrine FGF signaling in the brain and critically assess their putative role as therapeutic targets for treating metabolic disorders.

Glioblastoma multiforme influence on the elemental homeostasis of the distant organs: the results of inter-comparison study carried out with TXRF method

Glioblastoma (GBM) is a fast-growing and aggressive brain tumor which invades the nearby brain tissue but generally does not spread to the distant organs. Nonetheless, if untreated, GBM can result in patient death in time even less than few months from the diagnosis. The influence of the tumor progress on organs other than brain is obvious but still not well described. Therefore, we examined the elemental abnormalities appearing in selected body organs (kidney, heart, spleen, lung) in two rat models of GBM. The animals used for the study were subjected to the implantation of human GBM cell lines (U87MG and T98G) characterized by different levels of invasiveness. The elemental analysis of digested organ samples was carried out using the total reflection X-ray fluorescence (TXRF) method, independently, in three European laboratories utilizing various commercially available TXRF spectrometers. The comparison of the data obtained for animals subjected to T98G and U87MG cells implantation showed a number of elemental anomalies in the examined organs. What is more, the abnormalities were found for rats even if neoplastic tumor did not develop in their brains. The most of alterations for both experimental groups were noted in the spleen and lungs, with the direction of the found element changes in these organs being the opposite. The observed disorders of element homeostasis may result from many processes occurring in the animal body as a result of implantation of cancer cells or the development of GBM, including inflammation, anemia of chronic disease or changes in iron metabolism. Tumor induced changes in organ elemental composition detected in cooperating laboratories were usually in a good agreement. In case of elements with higher atomic numbers (Fe, Cu, Zn and Se), 88% of the results were classified as fully compliant. Some discrepancies between the laboratories were found for lighter elements (P, S, K and Ca). However, also in this case, the obtained results fulfilled the requirements of full (the results from three laboratories were in agreement) or partial agreement (the results from two laboratories were in agreement).

Cytocompatible and osteoconductive silicon oxycarbide glass scaffolds 3D printed by DLP: a potential material for bone tissue regeneration

Bone lesions affect individuals of different age groups, compromising their daily activities and potentially leading to prolonged morbidity. Over the years, new compositions and manufacturing technologies were developed to offer customized solutions to replace injured tissue and stimulate tissue regeneration. This work used digital light processing (DPL) technology for three-dimensional (3D) printing of porous structures using pre-ceramic polymer, followed by pyrolysis to obtain SiOC vitreous scaffolds. The SiOC scaffolds produced had an amorphous structure (compatible with glass) with an average porosity of 72.69% ± 0.99, an average hardness of 935.1 ± 71.0 HV, and an average maximum flexural stress of 7.8 ± 1.0 MPa, similar to cancellous bone tissue. The scaffolds were not cytotoxic and allowed adult stem cell adhesion, growth, and expansion. After treatment with osteoinductive medium, adult stem cells in the SiOC scaffolds differentiated to osteoblasts, assuming a tissue-like structure, with organization in multiple layers and production of a dense fibrous matrix rich in hydroxyapatite. The in vitro analyses supported the hypothesis that the SiOC scaffolds produced in this work were suitable for use as a bone substitute for treating critically sized lesions, with the potential to stimulate the gradual process of regeneration of the native tissue. The data obtained stimulate the continuity of studies with the SiOC scaffolds developed in this work, paving the way for evaluating safety and biological activity in vivo.

Phosphate Homeostasis and Disorders of Phosphate Metabolism

Phosphate is indispensable for human life and evolutionary changes over several millions of years have established tightly regulated mechanisms to ensure phosphate homeostasis. In this process, calcium and phosphate metabolism have come to be intricately linked together. Three hormones (PTH, FGF23 and Calcitriol) maintain the fine balance of calcium and phosphate metabolism through their actions at three sites (the gut, the kidneys and the skeleton). Disorders that disrupt this balance can have serious clinical consequences. Acute changes in serum phosphate levels can result in life threatening complications like respiratory failure and cardiac arrythmias. Chronic hypophosphataemia predominantly affects the musculoskeletal system and presents as impaired linear growth, rickets, osteomalacia and dental problems. Hyperphosphataemia is very common in the setting of chronic kidney disease and can be difficult to manage. A thorough understanding of calcium and phosphate homeostasis is essential to diagnose and treat conditions associated with hypo and hyperphosphataemia. In this review, we will discuss the calcium and phosphate metabolism, aetiologies and management of hypo and hyperphosphataemia.

Introduction to Osteoporosis, Osteomalacia, and Fragility Fractures

Background

Osteoporosis is a disease of the bones leading to decreased bone mineral density, leading to fragility fractures. This article is an overview of osteoporosis, osteomalacia and fragility fractures and serves as an introductory article for this special issue on osteoporosis.

Methods

This is a short, comprehensive account of the given conditions with concepts and a review from the recent literature. The authors provide relevant references from the literature in the bibliography. The sections herein have also been deliberated in the meetings of experts of osteoporosis.

Results

An overview of osteoporosis, osteomalacia and fragility fractures is provided, including definitions and summaries of aetiology, pathophysiology, diagnosis, prevention, and management. A detailed account of some of these topics will be provided in subsequent chapters.

Conclusion

Osteoporosis is a silent disease with the potential to cause significant morbidity and mortality if not detected early. It is important to differentiate from and diagnose associated osteomalacia to provide accurate therapy. It is also important to identify the type of fragility fractures and initiate treatment for bone strengthening to prevent subsequent fractures.

The Effect of Illumination Patterns during Mung Bean Seed Germination on the Metabolite Composition of the Sprouts

Mung bean (Vigna radiata (L.) Wilczek) sprouts are popular over the world because of their taste, nutritional value, well-balanced biochemical composition, and other properties beneficial for human health. Germination conditions affect the composition of metabolites in mung bean sprouts, so a detailed study into its variability is required. This article presents the results of a comparison of the metabolite composition in the leaves of mung bean sprouts germinated first in the dark (DS) and then in the light (LS). Gas chromatography with mass spectrometry (GC-MS) made it possible to identify more than 100 compounds representing various groups of phytochemicals. Alcohols, amino acids, and saccharides predominated in the total amount of compounds. The analysis of metabolomic profiles exposed a fairly high intra- and intervarietal variability in the metabolite content. DS and LS differed in the qualitative and quantitative content of the identified compounds. The intravarietal variability was more pronounced in DS than in LS. DS demonstrated higher levels of saccharides, fatty acids, acylglycerols, and phenolic compounds, while amino acids were higher in LS. Changes were recorded in the quantitative content of metabolites participating in the response of plants to stressors-ornithine, proline, GABA, inositol derivatives, etc. The changes were probably induced by the stress experienced by the sprouts when they were transferred from shade to light. The analysis of variance and principal factor analysis showed the statistically significant effect of germination conditions on the content of individual compounds in leaves. The identified features of metabolite variability in mung bean genotypes grown under different conditions will contribute to more accurate selection of an illumination pattern to obtain sprouts with desirable biochemical compositions for use in various diets and products with high nutritional value.

Resting state EEG rhythms in different stages of chronic kidney disease with mild cognitive impairment

Here, we tested that standard eyes-closed resting-state electroencephalographic (rsEEG) rhythms may characterize patients with mild cognitive impairment due to chronic kidney disease at stages 3-4 (CKDMCI-3&4) in relation to CKDMCI patients under hemodialysis (CKDMCI-H) and mild cognitive impairment (MCI) patients with cerebrovascular disease (CVMCI). Clinical and rsEEG data in 22 CKDMCI-3&4, 15 CKDMCI-H, 18 CVMCI, and 30 matched healthy control (HC) participants were available in a national archive. Spectral rsEEG power density was calculated from delta to gamma frequency bands at scalp electrodes. Results showed that (1) all MCI groups over the HC group showed decreased occipital rsEEG alpha power density; (2) compared to the HC and CVMCI groups, the 2 CKDMCI groups had higher rsEEG delta-theta power density; and (3) the CKDMCI-3&4 group showed the lowest parietal rsEEG alpha power density. The present rsEEG measures may be useful to monitor the impact of circulating uremic toxins on brain regulation of cortical arousal for quiet vigilance in CKDMCI patients.

A multifunctional polydopamine/genipin/alendronate nanoparticle licences fibrin hydrogels osteoinductive and immunomodulatory potencies for repairing bone defects

Here, we fabricated a hybrid nanoparticle composed of polydopamine nanoparticles (pNPs), alendronate (Al) and genipin (GP) for cranial bone defect repair. Al was crosslinked into pNPs via GP (Al@pNPs), after which hybrid nanoparticles were obtained. By embedding these Al@pNPs into the fibrin hydrogels, a multifunctional bone repair scaffold was fabricated (Al@pNPs/Fg). The Al@pNPs/Fg exhibited three synergistic effects on the bone microenvironment: i) enhanced ectomesenchymal stem cell (EMSC) osteogenic differentiation by activating the piezo 1 channel; ii) inhibited the formation and function of osteoclasts related to the NF-κB signaling pathways; and iii) promoted M2 polarization and anti-inflammatory factor expression under normal and simulated inflammatory conditions. Al@pNPs/Fg ultimately promoted cranial bone defect regeneration in an SD rat model. This simple and low-cost technology provides a new approach to constructing an efficient delivery system and has desirable biological properties, providing a tissue-committed niche for the repair of bone defects.

Risk Profile of Patients with Brushite Stone Disease and the Impact of Diet

This study examined the profile of patients and the impact of diet on the risk of brushite stone formation under controlled, standardized conditions. Sixty-five patients with brushite nephrolithiasis were enrolled in the study. Metabolic, dietary, and 24 h urinary parameters were collected under the habitual, self-selected diet of the patients and the balanced mixed, standardized diet. The [13C2]oxalate absorption, ammonium chloride, and calcium loading tests were conducted. All patients had at least one abnormality on the usual diet, with hypercalciuria (84.6%), increased urine pH (61.5%), and hyperphosphaturia (43.1%) being the most common. Absorptive hypercalciuria was present in 32.1% and hyperabsorption of oxalate in 41.2%, while distal renal tubular acidosis (dRTA) was noted in 50% of brushite stone formers. The relative supersaturation of brushite did not differ between patients with and without dRTA. Among all recent brushite-containing calculi, 61.5% were mixed with calcium oxalate and/or carbonate apatite. The relative supersaturation of brushite, apatite, and calcium oxalate decreased significantly under the balanced diet, mainly due to the significant decline in urinary calcium, phosphate, and oxalate excretion. Dietary intervention was shown to be effective and should be an integral part of the treatment of brushite stone disease. Further research on the role of dRTA in brushite stone formation is needed.

A nomogram for predicting sepsis-associated delirium: a retrospective study in MIMIC III

OBJECTIVE

To develop a nomogram for predicting the occurrence of sepsis-associated delirium (SAD).

MATERIALS AND METHODS

Data from a total of 642 patients were retrieved from the Medical Information Mart for Intensive Care (MIMIC III) database to build a prediction model. Multivariate logistic regression was performed to identify independent predictors and establish a nomogram to predict the occurrence of SAD. The performance of the nomogram was assessed in terms of discrimination and calibration by bootstrapping with 1000 resamples.

RESULTS

Multivariate logistic regression identified 4 independent predictors for patients with SAD, including Sepsis-related Organ Failure Assessment(SOFA) (p = 0.004; OR: 1.131; 95% CI 1.040 to 1.231), mechanical ventilation (P < 0.001; OR: 3.710; 95% CI 2.452 to 5.676), phosphate (P = 0.047; OR: 1.165; 95% CI 1.003 to 1.358), and lactate (P = 0.023; OR: 1.135; 95% CI 1.021 to 1.270) within 24 h of intensive care unit (ICU) admission. The area under the curve (AUC) of the predictive model was 0.742 in the training set and 0.713 in the validation set. The Hosmer - Lemeshow test showed that the model was a good fit (p = 0.471). The calibration curve of the predictive model was close to the ideal curve in both the training and validation sets. The DCA curve also showed that the predictive nomogram was clinically useful.

CONCLUSION

We constructed a nomogram for the personalized prediction of delirium in sepsis patients, which had satisfactory performance and clinical utility and thus could help clinicians identify patients with SAD in a timely manner, perform early intervention, and improve their neurological outcomes.

Association between serum phosphate and in-hospital mortality of patients with AECOPD: A retrospective analysis on eICU database

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is an important adverse event in the development of chronic obstructive pulmonary disease (COPD). Hyperphosphatemia is associated with higher mortality in patients with multiple diseases. In this study, we aimed to determine the relationship between serum phosphate and the risk of in-hospital mortality in patients with AECOPD. Methods: In the present study, patients with AECOPD were enrolled in the electronic Intensive Care Unit Collaborative Research Database (eICU-CRD), and divided into three groups according to the tertiles of serum phosphate level. The primary outcome measure was all-cause in-hospital mortality. The association between serum phosphate level and in-hospital mortality was investigated using multivariate logistic regression analysis. Moreover, subgroup analysis was performed to explore whether the relationship was consistent among different subgroups. Results: A total of 1199 AECOPD patients were included in this study. Non-survivors had higher serum phosphate levels than survivors. All patients were classified into lowest tertile, median tertile, and highest tertile, respectively. Multivariate logistic regression analysis indicated that serum phosphate was positively associated with in-hospital mortality after adjusting for confounders. Moreover, there was a significant trend across tertiles when serum phosphate level was diverted as a categorical variable. In addition, subgroup analysis demonstrated that serum phosphate was consistently associated with a higher risk of in-hospital mortality in different subgroups. Conclusion: Higher serum phosphate was positively associated with the increased in-hospital mortality in patients with AECOPD. Hyperphosphatemia may be an underlying high-risk factor for in-hospital mortality owing to AECOPD.

Elevated morbidity and mortality in patients with chronic idiopathic hypophosphatemia: a nationwide cohort study

Background

Chronic idiopathic hypophosphatemia (CIH) induced by X-linked hypophosphatemic rickets or tumor-induced osteomalacia is a rare inherited or acquired disorder. However, due to its rarity, little is known about the epidemiology and natural course of CIH. Therefore, we aimed to identify the prevalence and long-term health outcomes of CIH patients.

Methods

Using the Korean Health Insurance Review and Assessment claims database, we evaluated the incidence of hypophosphatemia initially diagnosed from 2003 to 2018. After excluding secondary conditions that could change serum phosphorus levels, we identified 154 patients (76 men and 78 women) with non-secondary and non-renal hypophosphatemia. These hypophosphatemic patients were compared at a ratio of 1:10 with age-, sex-, and index-year-matched controls (n = 1,540).

Results

In the distribution of age at diagnosis, a large peak was observed in patients aged 1-4 years and small peaks were observed in ages from 40-70 years. The age-standardized incidence rate showed non-statistically significant trend from 0.24 per 1,000,000 persons in 2003 to 0.30 in 2018. Hypophosphatemic patients had a higher risk of any complication (adjusted hazard ratio [aHR], 2.17; 95% confidence interval [CI], 1.67-2.69) including cardiovascular outcomes, chronic kidney disease, hyperparathyroidism, osteoporotic fractures, periodontitis, and depression. Hypophosphatemic patients also had higher risks of mortality and hospitalization than the controls (aHR, 3.26; 95% CI, 1.83-5.81; and aHR, 2.49; 95% CI, 1.97-3.16, respectively).

Conclusion

This first nationwide study of CIH in South Korea found a bimodal age distribution and no sex differences among patients. Hypophosphatemic patients had higher risks of complications, mortality, and hospitalization compared to age- and sex-matched controls.

Targeting aging with the healthy skeletal system: The endocrine role of bone

Aging is an inevitable biological process, and longevity may be related to bone health. Maintaining strong bone health can extend one's lifespan, but the exact mechanism is unclear. Bone and extraosseous organs, including the heart and brain, have complex and precise communication mechanisms. In addition to its load bearing capacity, the skeletal system secretes cytokines, which play a role in bone regulation of extraosseous organs. FGF23, OCN, and LCN2 are three representative bone-derived cytokines involved in energy metabolism, endocrine homeostasis and systemic chronic inflammation levels. Today, advanced research methods provide new understandings of bone as a crucial endocrine organ. For example, gene editing technology enables bone-specific conditional gene knockout models, which allows the study of bone-derived cytokines to be more precise. We systematically evaluated the various effects of bone-derived cytokines on extraosseous organs and their possible antiaging mechanism. Targeting aging with the current knowledge of the healthy skeletal system is a potential therapeutic strategy. Therefore, we present a comprehensive review that summarizes the current knowledge and provides insights for futures studies.

ANALYSIS OF THE RELATIONSHIP BETWEEN EARLY SERUM PHOSPHATE LEVELS AND SHORT-TERM MORTALITY IN SEPTIC PATIENTS: A RETROSPECTIVE STUDY BASED ON MIMIC-IV

ABSTRACT

Objective: The aim of the study is to explore the impact of early serum phosphate levels on the prognosis of critically ill patients with sepsis. Methods: In this retrospective large cohort study, data of patients with sepsis were obtained from the Medical Information Mart for Intensive Care IV database. Patients were retrospectively divided into a control group and three study groups according to their daily serum phosphate levels within 2 days of intensive care unit (ICU) admission. A Cox regression model was used to evaluate the association between serum phosphate levels and 28-day morbidity. Results: This study included 9,691 patients diagnosed with sepsis. During the first 2 days of ICU admission, patients with hyperphosphatemia in either of the 2 days had higher 28-day mortality, while patients in the hypophosphatemia group had lower 28-day mortality (first day, 32.9% vs. 16.3%; second day, 36.3% vs. 14.7%). After adjusting for potential confounders, hyperphosphatemia was significantly associated with 28-day mortality; however, only hypophosphatemia on the second day was independently associated with reduced 28-day mortality. After stratification in the hypophosphatemia group, subgroup analysis showed that only the association between the mild hypophosphatemia group and 28-day mortality reached statistical significance (hazard ratio = 0.76, 95% CI = 0.65-0.89, P = 0.001). Conclusions: Mild hypophosphatemia might improve the short-term prognosis of patients with sepsis, and hyperphosphatemia is an independent risk factor for the outcomes of septic patients. After ICU admission, the serum phosphate levels on the second day had a better independent correlation with 28-day mortality, which prompted us to reconsider the optimal timing of phosphate evaluation.

Neutralization of Intracellular pH Homeostasis to Inhibit Osteoclasts Based on a Spatiotemporally Selective Delivery System

Osteoporosis is a global disease caused by abnormal overactivation of osteoclasts. The acidic environment in sealing zone of osteoclasts with H⁺ pumped from cytoplasm is critical to the maturation of osteoclasts. Therefore, reducing the intracellular H⁺ concentration can reduce the H⁺ secretion of osteoclasts from the source. In our study, we developed a novel nanovesicle which encapsulates Na₂HPO₄ with a liposome hybridizes with preosteoclast membrane (Na₂HPO₄@Lipo-pOCm). These nanovesicles release Na₂HPO₄ into the preosteoclast by targeting preosteoclasts and membrane fusion, reducing the intracellular H⁺ concentration, and achieve biological cascade regulation of osteoclasts through simple pH regulation. In vitro and in vivo experiments confirmed that these nanovesicles reduce mitochondrial membrane potential by decreasing intracellular H⁺ concentration, thereby reducing the ROS in osteoclasts as well as the expression of the upstream transcription factor FOXM1 of Acp5. In short, this nanovesicle can significantly inhibit the osteoclasts and ameliorate osteoporosis caused by OVX.

Focusing on Phosphorus Loads: From Healthy People to Chronic Kidney Disease

Phosphorus is an essential micromineral with a key role in cellular metabolism and tissue structure. Serum phosphorus is maintained in a homeostatic range by the intestines, bones, and kidneys. This process is coordinated by the endocrine system through the highly integrated actions of several hormones, including FGF23, PTH, Klotho, and 1,25D. The excretion kinetics of the kidney after diet phosphorus load or the serum phosphorus kinetics during hemodialysis support that there is a "pool" for temporary phosphorus storage, leading to the maintenance of stable serum phosphorus levels. Phosphorus overload refers to a state where the phosphorus load is higher than is physiologically necessary. It can be caused by a persistently high-phosphorus diet, renal function decline, bone disease, insufficient dialysis, and inappropriate medications, and includes but is not limited to hyperphosphatemia. Serum phosphorus is still the most commonly used indicator of phosphorus overload. Trending phosphorus levels to see if they are chronically elevated is recommended instead of a single test when judging phosphorus overload. Future studies are needed to validate the prognostic role of a new marker or markers of phosphorus overload.

Oxidative Stress and Natural Antioxidants in Osteoporosis: Novel Preventive and Therapeutic Approaches

This review reports in detail the cellular and molecular mechanisms which regulate the bone remodeling process in relation to oxidative stress (OS), inflammatory factors, and estrogen deficiency. OS is considered an important pathogenic factor of osteoporosis, inducing osteocyte apoptosis and varying levels of specific factors, such as receptor activator κB ligand (RANKL), sclerostin, and, according to recent evidence, fibroblast growth factor 23, with consequent impairment of bone remodeling and high bone resorption. Bone loss increases the risk of fragility fractures, and the most commonly used treatments are antiresorptive drugs, followed by anabolic drugs or those with a double effect. In addition, recent data show that natural antioxidants contained in the diet are efficient in preventing and reducing the negative effects of OS on bone remodeling and osteocytes through the involvement of sirtuin type 1 enzyme. Indeed, osteocytes and some of their molecular factors are considered potential biological targets on which antioxidants can act to prevent and reduce bone loss, as well as to promote bone anabolic and regenerative processes by restoring physiological bone remodeling. Several data suggest including antioxidants in novel therapeutic approaches to develop better management strategies for the prevention and treatment of osteoporosis and OS-related bone diseases. In particular, anthocyanins, as well as resveratrol, lycopene, oleuropein, some vitamins, and thiol antioxidants, could have protective and therapeutic anti-osteoporotic effects.

Mild Hypophosphatemia-Associated Conditions in Children: The Need for a Comprehensive Approach

To better understand the causes of hypophosphatemia in children, we evaluated all serum phosphate tests performed in a tertiary hospital with unexpected but persistent temporary or isolated hypophosphatemia over an 18 year period. We collected 29,279 phosphate tests from 21,398 patients, of which 268 (1.2%) had at least one result showing hypophosphatemia. We found that endocrinopathies (n = 60), tumors (n = 10), and vitamin D deficiency (n = 3) were the medical conditions most commonly associated with mild hypophosphatemia, but in many patients the cause was unclear. Among patients with endocrinopathies, those with diabetes mellitus were found to have lower mean serum phosphate levels (mean 3.4 mg/dL) than those with short stature (3.7 mg/dL) or thyroid disorders (3.7 mg/dL). In addition, we found a correlation between glycemia and phosphatemia in patients with diabetes. However, despite the potential relevance of monitoring phosphate homeostasis and the underlying etiologic mechanisms, renal phosphate losses were estimated in less than 5% of patients with hypophosphatemia. In the pediatric age group, malignancies, hypovitaminosis D, and endocrine disorders, mostly diabetes, were the most common causes of hypophosphatemia. This real-world study also shows that hypophosphatemia is frequently neglected and inadequately evaluated by pediatricians, which emphasizes the need for more education and awareness about this condition to prevent its potentially deleterious consequences.

Progress and current trends in the electrochemical determination of phosphate ions for environmental and biological monitoring applications

The determination of phosphate ions in biological testing is critical for environmental safety. A reliable and accurate method is required to measure the true phosphate ion concentrations; in this regard, the electrochemical method is preferable because of its simple operation, fast response, and high sensitivity. By compiling existing electroanalytical techniques, researchers can compare the advantages and disadvantages of each method. This review examines the progress and recent advances in electrochemical sensing strategies adapted for the determination of phosphate ions in the environmental and during biological monitoring. We first discuss the history of phosphorus and the development of methods to detect phosphates. The recognition elements of phosphate ion sensors for environmental applications include metal-based, nanomaterial-based, carbon-based, and enzymatic electrodes. Phosphate determination in biological samples, such as blood serum, drugs, and other biological fluids, such as urine and saliva, as well as phosphate esters, is also discussed. The final part of our review addresses the current challenges that phosphate sensing technology faces and illustrates future opportunities for more reliable phosphate detection.

FGF23 functions and disease

The main function of fibroblast growth factor 23 (FGF23) is the regulation of phosphate metabolism through its action on the sodium-dependent phosphate cotransporters in the proximal renal tubules. Additionally, FGF23 interacts with vitamin D and parathyroid hormone in a complex metabolic pathway whose detailed mechanisms are still not clear in human physiology and disease. More recently, research has also focused on the understanding of mechanisms of FGF23 action on organs and system other than the kidneys and bone, as well as on its interaction with other metabolic pathways. Collectively, the new evidence are successfully used for the clinical evaluation and management of FGF23-related disorders, for which new therapies with many potential applications are now available.

The Application of Black Phosphorus Nanomaterials in Bone Tissue Engineering

Recently, research on and the application of nanomaterials such as graphene, carbon nanotubes, and metal-organic frameworks has become increasingly popular in tissue engineering. In 2014, a two-dimensional sheet of black phosphorus (BP) was isolated from massive BP crystals. Since then, BP has attracted significant attention as an emerging nanomaterial. BP possesses many advantages such as light responsiveness, electrical conductivity, degradability, and good biocompatibility. Thus, it has broad prospects in biomedical applications. Moreover, BP is composed of phosphorus, which is a key bone tissue component with good biocompatibility and osteogenic repair ability. Thereby, BP exhibits excellent advantages for application in bone tissue engineering. In this review, the structure and the physical and chemical properties of BP are described. In addition, the current applications of BP in bone tissue engineering are reviewed to aid the future research and application of BP.

Osteomalacia Is Not a Single Disease

Among bone-material qualities, mineralization is pivotal in conferring stiffness and toughness to the bone. Osteomalacia, a disease ensuing from inadequate mineralization of the skeleton, is caused by different processes leading to decreased available mineral (calcium and/or phosphate) or enzymatic alterations. Vitamin D deficiency, which remains the major cause of altered mineralization leading to inadequate intestinal calcium and phosphate absorption, may be also associated with other conditions primarily responsible for abnormal mineralization. Given the reality of widespread vitamin D inadequacy, a full biochemical assessment of mineral metabolism is always necessary to rule out or confirm other conditions. Both too-high or too-low serum alkaline phosphatase (ALP) levels are important for diagnosis. Osteomalacic syndrome is reversible, at least in part, by specific treatment. Osteomalacia and bone mineralization themselves constitute largely unexplored fields of research. The true prevalence of the different forms of osteomalacia and the recovery after proper therapy have yet to be determined in the real world. Although non-invasive techniques to assess bone mineralization are not available in clinical practice, the systematic assessment of bone quality could help in refining the diagnosis and guiding the treatment. This review summarizes what is known of osteomalacia recent therapeutic developments and highlights the future issues of research in this field.