Nanoparticle-Mediated Multiple Modulation of Bone Microenvironment To Tackle Osteoarthritis

Development of nanomedicines that can collaboratively scavenge reactive oxygen species (ROS) and inhibit inflammatory cytokines, along with osteogenesis promotion, is essential for efficient osteoarthritis (OA) treatment. Herein, we report the design of a ROS-responsive nanomedicine formulation based on fibronectin (FN)-coated polymer nanoparticles (NPs) loaded with azabisdimethylphoaphonate-terminated phosphorus dendrimers (G4-TBP). The constructed G4-TBP NPs-FN with a size of 268 nm are stable under physiological conditions, can be specifically taken up by macrophages through the FN-mediated targeting, and can be dissociated in the oxidative inflammatory microenvironment. The G4-TBP NPs-FN loaded with G4-TBP dendrimer having intrinsic anti-inflammatory property and FN having both anti-inflammatory and antioxidative properties display integrated functions of ROS scavenging, hypoxia attenuation, and macrophage M2 polarization, thus protecting macrophages from apoptosis and creating designed bone immune microenvironment for stem cell osteogenic differentiation. These characteristics of the G4-TBP NPs-FN lead to their effective treatment of an OA model in vivo to reduce pathological changes of joints including synovitis inhibition and cartilage matrix degradation and simultaneously promote osteogenic differentiation for bone repair. The developed nanomedicine formulation combining the advantages of both bioactive phosphorus dendrimers and FN to treat OA may be developed for immunomodulatory therapy of different inflammatory diseases.

Sevelamer reverses liver fibrosis by deactivation of hepatic stellate cells

Liver fibrosis is a chronic liver disease characterized by a progressive wound healing response caused by chronic liver injury. Currently, there are no approved clinical treatments for liver fibrosis. Sevelamer is used clinically to treat hyperphosphatemia and has shown potential therapeutic effects on liver diseases. However, there have been few studies evaluating the therapeutic effects of sevelamer on liver fibrosis, and the specific mechanisms are still unclear. In this study, we investigated the antifibrotic effects of sevelamer-induced low inorganic phosphate (Pi) stress in vitro and in vivo and analyzed the detailed mechanisms. We found that low Pi stress could inhibit the proliferation of activated hepatic stellate cells (HSCs) by promoting apoptosis, effectively suppressing the migration and epithelial-mesenchymal transition (EMT) of hepatic stellate cells. Additionally, low Pi stress significantly increased the antioxidant stress response. It is worth noting that low Pi stress indirectly inhibited the activation and migration of HSCs by suppressing transforming growth factor β (TGF-β) expression in macrophages. In a rat model of liver fibrosis, oral administration of sevelamer significantly decreased blood phosphorus levels, improved liver function, reduced liver inflammation, and increased the antioxidant stress response in the liver. Our study revealed that the key mechanism by which sevelamer inhibited liver fibrosis involved binding to gastrointestinal phosphate, resulting in a decrease in blood phosphorus levels, the downregulation of TGF-β expression in macrophages, and the inhibition of HSC migration and fibrosis-related protein expression. Therefore, our results suggest that sevelamer-induced low Pi stress can attenuate hepatic stellate cell activation and inhibit the progression of liver fibrosis, making it a potential option for the treatment of liver fibrosis and other refractory chronic liver diseases.

Biochemical markers of iron status and iron accumulation in peritoneal dialysis patients treated with ferric citrate

BACKGROUND

Hyperphosphataemia is a common complication of kidney disease. Current dialysis techniques do not provide enough phosphorus clearance, hence the need to use phosphorus binders. Treatment options include calcium carbonate, calcium acetate, lanthanum carbonate, sevelamer hydrochloride and iron-based binders. Patients receiving peritoneal dialysis (PD) with sustained elevated ferritin levels exceeding 800 ng/mL are at a higher risk of death. We identify PD patients treated with iron-based binders and compare ferritin and risk of iron accumulation to patients treated with non-iron-based binders.

METHODS

All records of patients receiving PD at Emory dialysis centres until 30 October 2021 were reviewed for phosphorus binders. Basic demographics and laboratory data were time-referenced to the days on treatment with a particular binder. Patients were followed until discontinuation of the phosphorus binder, death, transplant, transfer to another dialysis provider or censoring at 36 months after medication was started.

RESULTS

Compared to calcium acetate and sevelamer, ferric citrate utilisation in PD patients resulted in a sustained increase in ferritin. The proportion of patients with a ferritin equal to or greater than 800 ng/dL and transferrin saturation greater than 40% increased over time in patients treated with ferric citrate and was higher during the second and third year of follow-up compared to baseline values and to patients treated with calcium acetate or sevelamer. Two patients (7%) treated with ferric citrate developed clinically significant haemosiderosis.

CONCLUSIONS

Use of ferric citrated in PD resulted in significant iron accumulation as judged by ferritin levels.

Black Phosphorus Flake-Enabled Wireless Neuromodulation for Epilepsy Treatment

Epilepsy is a prevalent and severe neurological disorder and generally requires prolonged electrode implantation and tether brain stimulation in refractory cases. However, implants may cause potential chronic immune inflammation and permanent tissue damage due to material property mismatches with soft brain tissue. Here, we demonstrated a nanomaterial-enabled near-infrared (NIR) neuromodulation approach to provide nongenetic and nonimplantable therapeutic benefits in epilepsy mouse models. Our study showed that crystal-exfoliated photothermal black phosphorus (BP) flakes could enhance neural activity by altering the membrane capacitive currents in hippocampus neurons through NIR photothermal neuromodulation. Optical stimulation facilitated by BP flakes in hippocampal slices evoked action potentials with a high spatiotemporal resolution. Furthermore, BP flake-enabled NIR neuromodulation of hippocampus neural circuits can suppress epileptic signals in epilepsy model mice with minimal invasiveness and high biocompatibility. Consequently, nanomaterial-enabled NIR neuromodulation may open up opportunities for nonimplantable optical therapy of epilepsy in nontransgenic organisms.

Linear growth of children with X-linked hypophosphatemia treated with burosumab: a real-life observational study

To assess the long-term efficacy of burosumab for pediatric patients with X-linked hypophosphatemia, focusing on linear growth. This multi-center retrospective study included 35 pediatric patients who began treatment with burosumab between January 2018 and January 2021. We collected clinical data, anthropometric measurements, laboratory results, and Rickets Severity Score (RSS), from 2 years prior to treatment initiation and up to 4 years after. Burosumab was initiated at a mean age of 7.5 ± 4.4 years (range 0.6-15.9), with a mean initial dose of 0.8 ± 0.3 mg/kg, which was subsequently increased to 1.1 ± 0.4 mg/kg. The patients were followed for 2.9 ± 1.4 years (range 1-4) after initiating burosumab. Serum phosphorus levels increased from 2.7 ± 0.8 mg/dl at burosumab initiation to 3.4 ± 0.6 mg/dl after 3 months and remained stable (p < 0.001). Total reabsorption of phosphorus increased from 82.0 ± 6.8 to 90.1 ± 5.3% after 12 months of treatment (p = 0.041). The RSS improved from 1.7 ± 1.0 at burosumab initiation to 0.5 ± 0.6 and 0.3 ± 0.6 after 12 and 24 months, respectively (p < 0.001). Both height z-score and weight z-score improved from burosumab initiation to the end of the study: from - 2.07 ± 1.05 to - 1.72 ± 1.04 (p < 0.001) and from - 0.51 ± 1.12 to - 0.11 ± 1.29 (p < 0.001), respectively. Eight children received growth hormone combined with burosumab treatment. Height z-score improved among those who received growth hormone (from - 2.33 ± 1.12 to - 1.94 ± 1.24, p = 0.042) and among those who did not (from - 2.01 ± 1.01 to - 1.66 ± 1.01, p = 0.001).

CONCLUSION

 Burosumab treatment in a real-life setting improved phosphate homeostasis and rickets severity and enhanced linear growth.

WHAT IS KNOWN

• Compared to conventional therapy, burosumab treatment has been shown to increase serum phosphate levels and reduce the severity of rickets. • The effect of burosumab on growth is still being study.

WHAT IS NEW

• Height z-score improved between the start of burosumab treatment and the end of the study (-2.07 ± 1.05 vs. -1.72 ± 1.04, p < 0.001). • Eight children received burosumab combined with growth hormone treatment without side effects during the concomitant treatments.

Protective effect of activated charcoal against progression of chronic kidney disease: A randomized clinical study

Chronic kidney disease (CKD) is a non-reversible and progressive disease affecting the kidneys, significantly impacting global public health. One of the complications of chronic kidney disease is impaired intestinal barrier function, which may allow harmful products such as urea to enter the bloodstream and cause systemic inflammation. This study aimed to investigate whether supplementation with activated charcoal could reduce uremic toxins in patients with end-stage renal disease (ESRD). The study was a randomized clinical trial conducted at the Dialysis Center of al Diwaniyah Medical Hospital in the Diwaniyah Governorate. Eighty-two patients with ESRD on regular hemodialysis were enrolled, with 15 patients receiving oral supplementation with activated charcoal in addition to standard care and 13 patients receiving only standard care. Blood samples were collected at baseline and after eight weeks, and several biomarkers were measured, including estimated glomerular filtration rate (eGFR), creatinine, urea, phosphorus, albumin, and indoxyl sulfate. The results showed a significant reduction in both serum urea and serum phosphorus levels after eight weeks of oral-activated charcoal treatment. However, the other biomarkers were not affected by the treatment. In conclusion, the use of oral-activated charcoal for eight weeks in Iraqi patients undergoing maintenance hemodialysis improved urea and phosphorus levels.

2D Hetero-Nanoconstructs of Black Phosphorus for Breast Cancer Theragnosis: Technological Advancements

As per global cancer statistics of 2020, female breast cancer is the most commonly diagnosed cancer and also the foremost cause of cancer death in women. Traditional treatments include a number of negative effects, making it necessary to investigate novel smart drug delivery methods and identify new therapeutic approaches. Efforts for developing novel strategies for breast cancer therapy are being devised worldwide by various research groups. Currently, two-dimensional black phosphorus nanosheets (BPNSs) have attracted considerable attention and are best suited for theranostic nanomedicine. Particularly, their characteristics, including drug loading efficacy, biocompatibility, optical, thermal, electrical, and phototherapeutic characteristics, support their growing demand as a potential substitute for graphene-based nanomaterials in biomedical applications. In this review, we have explained different platforms of BP nanomaterials for breast cancer management, their structures, functionalization approaches, and general methods of synthesis. Various characteristics of BP nanomaterials that make them suitable for cancer therapy and diagnosis, such as large surface area, nontoxicity, solubility, biodegradability, and excellent near-infrared (NIR) absorption capability, are discussed in the later sections. Next, we summarize targeting approaches using various strategies for effective therapy with BP nanoplatforms. Then, we describe applications of BP nanomaterials for breast cancer treatment, which include drug delivery, codelivery of drugs, photodynamic therapy, photothermal therapy, combined therapy, gene therapy, immunotherapy, and multidrug resistance reversal strategy. Finally, the present challenges and future aspects of BP nanomaterials are discussed.

Peripheral Skeletal Muscle Impairment in Children After Treatment for Leukemia and Lymphoma

Exercise intolerance is a common adverse effect of childhood cancer, contributing to impaired health and well-being. While reduced aerobic fitness has been attributed to central cardiovascular deficiencies, the involvement of peripheral musculature has not been investigated. We studied peripheral muscle function in children following cancer treatment using noninvasive phosphorus-31 magnetic resonance spectroscopy. Ten acute lymphoblastic leukemia (ALL) and 1 lymphoma patient 8 to 18 years of age who completed treatment 6 to 36 months prior and 11 healthy controls participated in the study. Phosphorus-31 magnetic resonance spectroscopy was used to characterize muscle bioenergetics at rest and following an in-magnet knee-extension exercise. Exercise capacity was evaluated using a submaximal graded treadmill test. Both analysis of variance and Cohen d were used as statistical methods to determine the statistical significance and magnitude of differences, respectively, on these parameters between the patient and control groups. The patients treated for ALL and lymphoma exhibited lower anaerobic function ( P =0.14, d =0.72), slower metabolic recovery ( P =0.08, d =0.93), and lower mechanical muscle power ( d =1.09) during exercise compared with healthy controls. Patients demonstrated lower estimated VO 2peak (41.61±5.97 vs. 47.71±9.99 mL/min/kg, P =0.11, d =0.76), lower minutes of physical activity (58.3±35.3 vs. 114.8±79.3 min, P =0.12, d =0.99) and higher minutes of inactivity (107.3±74.0 vs. 43.5±48.3 min, d =1.04, P <0.05). Children treated for ALL and lymphoma exhibit altered peripheral skeletal muscle metabolism during exercise. Both deconditioning and direct effects of chemotherapy likely contribute to exercise intolerance in this population.

Current therapeutic options for the treatment of secondary hyperparathyroidism in end-stage renal disease patients treated with hemodialysis: a 12-month comparative study

AIM

The aim of the study was to investigate the effect of a new calcimimetic, Etelcalcetide, on secondary hyperparathyroidism and its effects in end-stage renal disease (ESRD) patients treated with hemodialysis (HD) compared with hemodialysis (HD) patients not treated with calcimimetics.

MATERIALS AND METHODS

The cohort study included 203 ESRD patients with secondary hyperparathyroidism (SHPT) who received HD treatment. Total number patients were randomly to two groups. The main group (n=71) included HD patients treated by new calcimimetic Etelcalcetide. The historical group (n=132) was evaluated retrospectively and included patients who had SHPT but did not receive calcimimetic treatment. Serum levels of phosphorus, calcium and parathyroid hormone were compared for 12 months. The primary endpoint of the study was death from any cause, surrogates - cases of fractures, parathyroidectomy, death from cardiovascular (CV) events.

RESULTS

The dose of Etelcalcetide changed monthly and averaged 8.58±1.79 mg. The dynamics of parathormone (PTH) indicators showed that the decrease in PTH levels by 30% from basal occurred after 3 months of treatment in 39 (54.9%) and 12 (9.1%) patients of the main group and historical group, respectively (p<0.0001). At the end of the study, the target PTH level reached in 52 (73.2%) patients in the main group and only 14 (10.6%) in the comparison group (p<0.0001). In addition to the decrease in serum PTH content, in the main group of patients, there was also a decrease in serum calcium and phosphorus levels. During the time to be analyzed, 36 deaths were reported, 61.1% of which were fatal CV events. The proportion of CV events in the mortality structure is more than 70% higher in the historical group than in the group of patients treated with Etelcalcetide, and is 69,2% vs 40,0%, respectively. The frequency of fractures is almost three times higher in the historical than in the main group of patients. The proportion of patients who required parathyroidectomy was significantly more than three times higher in the historical group than in the main group (p<0,05).

CONCLUSIONS

In a prospective study, we demonstrated the high efficacy of Etelcalcetide in the treatment of SHPT in hemodialysis patients. Treatment of SHPT with the inclusion of Etelcalcetide is accompanied by improved clinical outcomes such as the incidence of bone fractures, cardiovascular morbidity and mortality.

Abalone-Inspired Adhesive and Photo-Responsive Microparticle Delivery Systems for Periodontal Drug Therapy

Antibiotics provide promising strategies for treating periodontitis, while their delivery and controllable release with desired oral retention remain challenging. Here, inspired by the unique suction-cup structures of abalones, a novel adhesive and photo-responsive microparticle (MP) delivery system is developed to treat periodontitis through microfluidic electrospray technology. Such MPs are generated by quickly ionic cross-linking of sodium alginate together with photo-curing of poly(ethylene glycol) diacrylate of the distorted microfluidic droplets during their high-speed dropping into calcium chloride solution. Attributing to their unique concave structures, the abalone-inspired MPs exhibit desired underwater adhesion ability and stability under running water. In addition, due to the loading of antibiotics minocycline hydrochloride and near-infrared (NIR)-responsive black phosphorus during their fabrication, the resultant MPs can not only eradicate bacteria directly, but also realize a controllable and effective drug release upon NIR irradiation. Based on these features, it is demonstrated from in vivo periodontitis that the abalone-inspired MPs are firmly adhesive and can controlled-release drugs on the tooth, and thus have outstanding antibacterial efficacy against Porphyromonas gingivalis. These results indicate the particular values of the abalone-inspired MPs for oral-related disease treatment.

Early calcium and phosphorus supplementation in VLBW infants to reduce metabolic bone disease of prematurity: a quality improvement initiative

Objective

To reduce the incidence of metabolic bone disease (MBD) among very low birthweight (VLBW) infants admitted to neonatal intensive care unit from baseline of 35% by 50% over 2 years by implementing a quality improvement (QI) initiative.

Methods

A multidisciplinary QI team used evidence-based interventions and the healthcare improvement model to reduce MBD rate in VLBW infants. The specific interventions included routine enteral supplementation of calcium and phosphorus using Human Milk Fortifier (HMF) to expressed breast milk by day 14 of life (Plan/Do/Study/Act (PDSA) cycle 1), parenteral and early enteral supplementation of calcium and phosphorus (PDSA cycles 2 and 3). We included VLBW infants admitted within the study period at birth and excluded babies with congenital malformations, skeletal disorders and those who died before 2 weeks of age. Compliance with adding HMF by day 14, compliance with adding calcium and phosphorus in total parenteral nutrition (TPN) from day 1 of life and compliance with starting HMF when the baby reached 100 mL/kg/day of feeds were used as process indicators. The incidence of MBD was used as an outcome indicator during the study. The incidence of MBD was tracked using the Statistical Process Control methodology.

Results

The baseline MBD rate in 2015 was 35%. After the first PDSA cycle, 20% developed MBD (p=0.02). The same was sustained for a period of 1 year with the rate of 22%. After the second and third PDSA cycles, there was a drop in the MBD rate to 17%, and sustained for 3 months with 21%.

Conclusion

Implementation of QI initiatives decreased the MBD rate from 35% to <20%. Early parenteral calcium and phosphorus supplementation in TPN and optimising enteral supplementation with multicomponent fortifiers appear to have significant reduction in the incidence of MBD.

Effects of Bisphosphonate on Osteocyte Proliferation and Bone Formation in Patients with Diabetic Osteoporosis

Background

Bisphosphonate is currently considered one of the drugs for the first-line treatment of osteoporosis because of its ability to inhibit bone resorption, but the molecular mechanism of its effect on osteocyte proliferation and bone formation of diabetic osteoporosis is still unclear.

Objective

To confirm the potential effect on of bisphosphonate on osteocyte proliferation and bone formation in patients having diabetic osteoporosis (DO).

Methods

Sixty DO patients admitted to our hospital from February 2019 to April 2021 were randomly selected and divided into the bisphosphonate group and the control group. The total incidence, incidence of hip fracture, efficacy, bone mineral density, osteocalcin, pain score, osteocyte proliferation, bone formation index, serum calcium, and phosphorus contents were compared between two groups.

Results

The curative effect of bisphosphonic acid group was better than that of control group, and the difference was statistically significant (P < 0.05). Compared with the control group, the bone mineral density and osteocalcin in the bisphosphonic acid group were significantly improved after treatment, and the pain score in the bisphosphonic acid group was significantly lower than that in the control group (P < 0.05). After intervention treatment, the OD and PINP values in the bisphosphonate group were significantly different from those in the control group (P < 0.05). After treatment, the contents of serum calcium and phosphorus in the bisphosphonic acid group were significantly higher than those in the control group (P < 0.05). The incidence of hip fracture, spinal fracture, and other fractures in the bisphosphonic acid group was significantly lower than that in the control group (P < 0.05).

Conclusion

The treatment of DO with bisphosphonate is capability of effectively improving bone cell proliferation and bone formation, further alleviating clinical symptoms and promoting the improvement of the disease.

Meta-Analysis of Effects of Nutritional Intervention Combined with Calcium Carbonate D3 Tablets on Bone Mineral Density, Bone Metabolism, and Curative Effect in Patients with Osteoporosis

To investigate the changes in bone mineral density, bone metabolism, and efficacy of nutritional intervention combined with calcium carbonate D3 tablets in patients with osteoporosis, a RevMan 5.2 software meta-analysis was conducted in this study. According to the therapeutic direction of nutritional intervention combined with calcium carbonate D3 tablets for osteoporosis patients, relevant literature were searched in Wanfang Medical, CNKI, VIP, and PubMed literature databases at home and abroad. Keywords included bone mineral density, bone metabolism, blood calcium (Ca), blood phosphorus (P), osteocalcin (OC), bone mineral density (BMD), serum alkaline phosphatase (ALP), efficacy, osteoporosis, and nutritional intervention. Literature that met the criteria were deleted, and meta-analysis was performed using RevMan 5.2 software. The results indicate that a total of 10 Chinese literature were included. Compared with the monotherapy group, the clinical efficacy, osteocalcin, BMD, alkaline phosphatase, calcium, and phosphorus were significantly higher in the combination group (P < 0.05). Based on calcium carbonate D3, treatment combined with nutritional intervention can enhance the clinical efficacy, bone metabolism, and bone mineral density of patients with osteoporosis, and nutritional intervention combined with calcium carbonate D3 tablets is a feasible program to promote the recovery of patients with osteoporosis.

The Effect of Sodium Thiosulfate on Coronary Artery Calcification in Hemodialysis Patients

This study aimed to effectively control the disease process of hemodialysis outpatients. Hemodialysis secondary hyperparathyroidism patients were randomly divided into the control group and treatment group. The control group was treated with routine treatment, and the treatment group was treated with sodium thiosulfate based on the control group. The changes of serum calcium, phosphorus, whole parathyroid hormone, calcium-phosphorus product and coronary artery calcification (CAC) score, as well as the relief of clinical symptoms, postoperative complications and recurrence in the preoperative and postoperative periods were observed. The levels of C-reactive protein and CAC scores were significantly decreased in the treatment group after treatment. While there was no significant difference in blood calcium, blood phosphorus, PTH, calcium-phosphorus product, and CAC score in the control group after treatment. And after treatment, the proportion of skin pruritus, myasthenia, bone pain, insomnia, restless legs syndrome, and other symptoms in the treatment group was significantly decreased compared with those before treatment, but there was no significant change in the control group before and after treatment. Sodium thiosulfate can reduce the high level of CAC in hemodialysis patients obviously.

A Composite Deferoxamine/Black Phosphorus Nanosheet/Gelatin Hydrogel Scaffold for Ischemic Tibial Bone Repair

Introduction

Bone delay union is mostly caused by lack of blood supply. Although autografts, allografts and artificial bone have been widely used to treat bone delay union, the bone regeneration fails in the ischemic site accompanied by the bone donor site complications and disease transmission. Recently, there is a growing recognition of the importance of hydrogel scaffolds which are regarded as an eligible engineer tissue for bone repair. However, hydrogel is still limited in improving neovascularization.

Methods

In this work, black phosphorus nanosheet and deferoxamine (BPN-DFO) were loaded in the gelatin hydrogel to overcome the high risk of bone delay union and systemically investigated the regeneration capability of BPN-DFO hydrogel in vitro and vivo.

Results

The resulting BPN-DFO hydrogel scaffold showed superior swollen, degradation and release rate, as well as satisfied biocompatibility. BPN-DFO hydrogel shown the significant up-expression of mRNA related to bone regeneration and cell proliferation. In vivo, the proposed BPN-DFO hydrogel significantly improved osteogenesis and neovascularization in the ischemic tibial bone site of SD rats with acute femoral artery occlusion. Both macroscopic and histological evaluation of new regenerated bone showed newly formed blood vessel and collagen using BPN-DFO hydrogel. The immunohistochemistry and RT-PCR revealed that the bone regeneration could be improved via BMP/Runx2 pathway.

Conclusion

The BPN-DFO hydrogel possesses potential tissue engineer material for ischemic bone defect treatment. However, furthermore studies are needed to testify the safety and efficacy of BPN-DFO hydrogel.

Reversing the Epithelial-Mesenchymal Transition in Metastatic Cancer Cells Using CD146-Targeted Black Phosphorus Nanosheets and a Mild Photothermal Treatment

Cancer metastasis leads to most deaths in cancer patients, and the epithelial-mesenchymal transition (EMT) is the key mechanism that endows the cancer cells with strong migratory and invasive abilities. Here, we present a nanomaterial-based approach to reverse the EMT in cancer cells by targeting an EMT inducer, CD146, using engineered black phosphorus nanosheets (BPNSs) and a mild photothermal treatment. We demonstrate this approach can convert highly metastatic, mesenchymal-type breast cancer cells to an epithelial phenotype (i.e., reversing EMT), leading to a complete stoppage of cancer cell migration. By using advanced nanomechanical and super-resolution imaging, complemented by immunoblotting, we validate the phenotypic switch in the cancer cells, as evidenced by the altered actin organization and cell morphology, downregulation of mesenchymal protein markers, and upregulation of epithelial protein markers. We also elucidate the molecular mechanism behind the reversal of EMT. Our results reveal that CD146-targeted BPNSs and a mild photothermal treatment synergistically contribute to EMT reversal by downregulating membrane CD146 and perturbing its downstream EMT-related signaling pathways. Considering CD146 overexpression has been confirmed on the surface of a variety of metastatic, mesenchymal-like cancer cells, this approach could be applicable for treating various cancer metastasis via modulating the phenotype switch in cancer cells.

PLGA-collagen-BPNS Bifunctional composite mesh for photothermal therapy of melanoma and skin tissue engineering

The treatment of melanoma requires not only the elimination of skin cancer cells but also skin regeneration to heal defects. To achieve this goal, a bifunctional composite scaffold of poly(DL-lactic-co-glycolic acid) (PLGA), collagen and black phosphorus nanosheets (BPNSs) was prepared by hybridizing a BPNS-embedded collagen sponge with a PLGA knitted mesh. The composite mesh increased the temperature under near-infrared laser irradiation. The incorporation of BPNSs provided the PLGA-collagen-BPNS composite mesh with excellent photothermal properties for the photothermal ablation of melanoma cells both in vitro and in vivo. The PLGA-collagen-BPNS composite mesh had high mechanical strength for easy handling. The PLGA-collagen-BPNS composite mesh facilitated the proliferation of fibroblasts, promoted the expression of angiogenesis-related genes and the genes of components of the extracellular matrix for skin tissue regeneration. The high mechanical strength, photothermal ablation capability and skin tissue regeneration effects demonstrate that the bifunctional PLGA-collagen-BPNS composite mesh is a versatile and effective platform for the treatment of melanoma and the regeneration of skin defects.

A Systematic Review and Meta-analysis of Efficacy and Safety of Calcimimetic Agents in the Treatment of Secondary Hyperparathyroidism in Patients with Chronic Kidney Disease

BACKGROUND

Some reports have pointed out that calcimimetics agents are effective in the treatment of secondary hyperparathyroidism (SHPT) in chronic kidney disease (CKD) patients, but there is no detailed description of the advantages and disadvantages of calcimimetics agents of SHPT in CKD patients. We tried to pool the published data to verify the effectiveness of calcimimetics agents and to compare the advantages and disadvantages of cinacalcet compared with control in the treatment of SHPT in CKD patients.

METHODS

We included eligible studies of published papers from January 1st, 2000 to December 31st, 2020 in Medline, Pubmed and Web of science databases, and the data were extracted for this meta-analysis.

RESULTS

Twenty-seven studies were eligible, and all the included studies were randomized controlled trials (RCT) including patients treated with long-term dialysis. The results indicated that calcimimetic agents can reduce the parathyroid hormone (PTH, pg/ml) level (WMD = -178.22, 95% CI: -238.57, -117.86, P < 0.00001), calcium (Ca, mg/dl) level (WMD = -0.71, 95% CI: -0.86, -0.55, P < 0.00001), phosphorus (P, mg/dl) level (WMD = -0.32, 95% CI: -0.55, -0.08, P = 0.008), calcium-phosphorus product level (WMD = -7.73, 95% CI: -9.64, -5.82, P < 0.00001). Calcimimetic agents increased the bone alkaline phosphatase (BSAP, ng/ml) levels and rate of achieving target PTH, and reduced osteocalcin levels and the rate of parathyroidectomy. Calcimimetic agents increased the total adverse events' rate, the rate of hypocalcemia and gastrointestinal side effects (nausea, vomiting, abdominal pain and diarrhea), but there was no significant difference in serious adverse events between the calcimimetic agent group and control group.

CONCLUSION

Calcimimetic agents can reduce the PTH level, Ca level, P level, calcium-phosphorus product level and do not increase serious adverse events.

Novel Engineered Bacterium/Black Phosphorus Quantum Dot Hybrid System for Hypoxic Tumor Targeting and Efficient Photodynamic Therapy

Intratumoral hypoxia significantly constrains the susceptibility of solid tumors to oxygen-dependent photodynamic therapy (PDT), and effort to reverse such hypoxia has achieved limited success to date. Herein, we developed a novel engineered bacterial system capable of targeting hypoxic tumor tissues and efficiently mediating the photodynamic treatment of these tumors. For this system, we genetically engineered Escherichia coli to express catalase, after which we explored an electrostatic adsorption approach to link black phosphorus quantum dots (BPQDs) to the surface of these bacteria, thereby generating an engineered E. coli/BPQDs (EB) system. Following intravenous injection, EB was able to target hypoxic tumor tissues. Subsequent 660 nm laser irradiation drove EB to generate reactive oxygen species (ROS) and destroy the membranes of these bacteria, leading to the release of catalase that subsequently degrades hydrogen peroxide to yield oxygen. Increased oxygen levels alleviate intratumoral hypoxia, thereby enhancing BPQD-mediated photodynamic therapy. This system was able to efficiently kill tumor cells in vivo, exhibiting good therapeutic efficacy. In summary, this study is the first to report the utilization of engineered bacteria to facilitate PDT, and our results highlight new avenues for BPQD-mediated cancer treatment.

Aggregation-Induced Emission Luminogens Married to 2D Black Phosphorus Nanosheets for Highly Efficient Multimodal Theranostics

Inspired by the respective advantages of aggregation-induced emission (AIE)-active photosensitizers and black phosphorus nanomaterials in cancer treatment, the facile construction of novel AIE photosensitizers married to 2D black phosphorus nanosheets and their application for multimodal theranostics are demonstrated. The developed nanomaterial simultaneously possesses distinctive properties and multiple functions including excellent stability, good biocompatibility, intensive fluorescence emission in the NIR region, high-performance reactive oxygen species generation, good photothermal conversion efficiency, outstanding cellular uptake, and effective accumulation at the tumor site. Both in vitro and in vivo evaluation show that the presented nanotheranostic system is an excellent candidate for NIR fluorescence-photothermal dual imaging-guided synergistic photodynamic-photothermal therapies. This study thus not only extends the applications scope of AIE and black phosphorus materials, but also offers useful insights into designing a new generation of cancer theranostic protocol for potential clinical applications.

Integration of a porous coordination network and black phosphorus nanosheets for improved photodynamic therapy of tumor

Selectively attenuating the protection offered by heat shock protein 90 (HSP90), which is indispensable for the stabilization of the essential regulators of cell survival and works as a cell guardian under oxidative stress conditions, is a potential approach to improve the efficiency of cancer therapy. Here, we designed a biodegradable nanoplatform (APCN/BP-FA) based on a Zr(iv)-based porphyrinic porous coordination network (PCN) and black phosphorus (BP) sheets for efficient photodynamic therapy (PDT) by enhancing the accumulation of the nanoplatforms in the tumor area and attenuating the protection of cancer cells. Owing to the favorable degradability of BP, the nanosystem exhibited accelerated the release of the HSP90 inhibitor tanespimycin (17-AAG) and an apparent promotion in the reactive oxygen species (ROS) yield of PCN as well as expedited the degradation of the PCN-laden BP nanoplatforms. Both in vitro and in vivo results revealed that the elevated amounts of ROS and reduced cytoprotection in tumor cells were caused by the nanoplatforms. This strategy may provide a promising method for attenuating cytoprotection to aid efficient photodynamic therapy.

Clearable Black Phosphorus Nanoconjugate for Targeted Cancer Phototheranostics

Therapeutic efficacy of synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) is limited by complex conjugation chemistry, absorption wavelength mismatch, and inadequate biodegradability of the PDT-PTT agents. Herein, we designed biocompatible copper sulfide nanodot anchored folic acid-modified black phosphorus nanosheets (BP-CuS-FA) to overcome these limitations, consequently enhancing the therapeutic efficiency of PDT-PTT. In vitro and in vivo assays reveal good biocompatibility and commendable tumor inhibition efficacy of the BP-CuS-FA nanoconjugate because of the synergistic PTT-PDT mediated by near-infrared laser irradiation. Importantly, folic acid unit could target folate receptor overexpressed cancer cells, leading to enhanced cellular uptake of BP-CuS-FA. BP-CuS-FA also exhibits significant contrast effect for photoacoustic imaging, permitting its in vivo tracking. The photodegradable character of BP-CuS-FA is associated with better renal clearance after the antitumor therapy in vivo. The present research may facilitate further development on straightforward approaches for targeted and imaging-guided synergistic PDT-PTT of cancer.

Silver-Laden Black Phosphorus Nanosheets for an Efficient In Vivo Antimicrobial Application

Nanobactericides represent one of the most efficient and promising strategies for eliminating bacterial infection considering the increasing resistance threats of conventional antibiotics. Black phosphorus (BP) is the most exciting postgraphene layered 2D nanomaterial with convincing physiochemical properties, yet the study of BP-based antibiotics is still in its infancy. Here, a compact silver nanoparticle (AgNP)-doped black phosphorus nanosheet (BPN) is constructed to synergistically enhance solar disinfection through the promoted reactive oxygen species (ROS) photogeneration, which is attributed to the improved electron-hole separation and recombination of BPNs as revealed from the systematic experimental studies. An in-depth density functional theory (DFT) calculation confirms that the integrated AgNPs provide a preferred site for facilitating the adsorption and activation of O₂ , thus promoting the more efficient and robust ROS generation on BPN-AgNP nanohybrids. Besides the enhanced photoinduced ROS, the anchored AgNPs simultaneously lead to a dramatically increased affinity toward bacteria, which facilitates a synergetic pathogen inactivation. Significantly, the convincing antimicrobial BPN-AgNP contributes to the prominent wound healing and antimicrobial ability in vivo with minimized biological burden. This sophisticated design of new 2D nanohybrids opens a new avenue for further exploiting BP-based nanohybrids in portable bandage and broad-spectrum disinfection applications.

The Association of Hypophosphatemia With Resistant Lactic Acidosis in Critical Care Illness

Critically ill patients are known to have a variety of electrolyte abnormalities. Lactic acidosis can frequently be seen secondary to shock states and is usually treated with aggressive volume resuscitation. Interestingly, hypophosphatemia is a potential cause of resistant lactic acidosis, which may not be as commonly identified or considered. We present a case of a 42-year-old man admitted twice over a span of 6 months with an elevated lactate level that did not resolve with volume resuscitation. It was ultimately determined that his lactic acidosis was due to hypophosphatemia after ruling out other potential causes. Phosphate replacement therapy resulted in the normalization of his lactate. In the literature, multiple theories have indicated the association of hypophosphatemia with lactic acidosis though no prior cases exist supporting a direct relationship. In this case, we set forth to evaluate the complicated relationship between all of these factors and to highlight the importance of early detection and treatment of hypophosphatemia, which may be beneficial in treating lactic acidosis.

Black Phosphorus-Based Multimodal Nanoagent: Showing Targeted Combinatory Therapeutics against Cancer Metastasis

In breast cancer chemophotothermal therapy, it is a great challenge for the development of multifunctional nanoagents for precision targeting and the effective treatment of tumors, especially for metastasis. Herein, we successfully design and synthesize a multifunctional black phosphorus (BP)-based nanoagent, BP/DTX@PLGA, to address this challenge. In this composite nanoagent, BP quantum dots (BPQDs) are loaded into poly(lactic-co-glycolic acid) (PLGA) with additional conjugation of a chemotherapeutic agent, docetaxel (DTX). The in vivo distribution results demonstrate that BP/DTX@PLGA shows striking tropism for targeting both primary tumors and lung metastatic tumors. Moreover, BP/DTX@PLGA exhibits outstanding controllable chemophotothermal combinatory therapeutics, which dramatically improves the efficacy of photothermal tumor ablation when combined with near-light irradiation. Mechanistically, accelerated DTX release from the nanocomplex upon heating and thermal treatment per se synergistically incurs apoptosis-dependent cell death, resulting in the elimination of lung metastasis. Meanwhile, in vitro and in vivo results further confirm that BP/DTX@PLGA possesses good biocompatibility. This study provides a promising BP-based multimodal nanoagent to constrain cancer metastasis.

Near-Infrared Activated Black Phosphorus as a Nontoxic Photo-Oxidant for Alzheimer's Amyloid-β Peptide

The inhibition of amyloid-β (Aβ) aggregation by photo-oxygenation has become an effective way of treating Alzheimer's disease (AD). New near-infrared (NIR) activated treatment agents, which not only possess high photo-oxygenation efficiency, but also show low biotoxicity, are urgently needed. Herein, for the first time, it is demonstrated that NIR activated black phosphorus (BP) could serve as an effective nontoxic photo-oxidant for amyloid-β peptide in vitro and in vivo. The nanoplatform BP@BTA (BTA: one of thioflavin-T derivatives) possesses high affinity to the Aβ peptide due to specific amyloid selectivity of BTA. Importantly, under NIR light, BP@BTA can significantly generate a high quantum yield of singlet oxygen (¹ O₂ ) to oxygenate Aβ, thereby resulting in inhibiting the aggregation and attenuating Aβ-induced cytotoxicity. In addition, BP could finally degrade into nontoxic phosphate, which guarantees the biosafety. Using transgenic Caenorhabditis elegans CL2006 as AD model, the results demonstrate that the ¹ O₂ -generation system could dramatically promote life-span extension of CL2006 strain by decreasing the neurotoxicity of Aβ.

A novel heterozygous mutation c.680A>G (p. N227S) in SLC34A1 gene leading to autosomal dominant hypophosphatemia: A case report

RATIONALE

Currently, the relationship between heterozygous mutations in SLC34A1 and hypophosphatemia is controversial. Here we report an autosomal dominant hypophosphatemia pedigree carrying a novel heterozygous mutation in SLC34A1.

PATIENT CONCERNS

The proband is a 32-year old young man, presented with progressive pain and weakness in his lower extremities for more than 5 years. The proband showed persistent hypophosphatemia and low TmPO4/GFR values, indicating renal phosphate leak. His grandfather, father, and one of his uncles showed the similar symptoms.

DIAGNOSES

Autosomal dominant hypophosphatemia.

INTERVENTIONS AND OUTCOMES

Phosphorus supplement was prescribed to the proband and his affected uncle. Both their serum phosphorus levels recovered to normal and their symptoms such as back pain and lower extremity weakness were completely relieved. Whole exome sequencing was performed to identify disease-causing mutations in proband.

LESSONS

A novel heterozygous missense mutation c.680A>G (p. N227S) in exon 7 of SLC34A1 was found in proband by whole exome sequencing, which was also found in other 4 family members of this pedigree. Our report of an autosomal dominant hypophosphatemia pedigree with 5 mutant carriers enriches the clinical phenotype caused by the SLC34A1 mutations and further affirms the heterozygous mutations are causative for hypophosphatemia.

Exfoliated Black Phosphorus Promotes in Vitro Bone Regeneration and Suppresses Osteosarcoma Progression through Cancer-Related Inflammation Inhibition

Nowadays chemotherapy is the main treatment for osteosarcoma disease, even if limited by the lack of selectivity between healthy and cancer cells during the inhibition of cell division. Herein, we propose the use of few-layer two-dimensional black phosphorous (2D bP) as an alternative tool for osteosarcoma treatment and report how 2D bP can stimulate newly forming bone tissue generation after osteosarcoma resection. In our study, we have developed an in vitro model to evaluate the efficacy of 2D bP material with and without near-infrared light irradiation treatment, and we have demonstrated that the presence of 2D bP without treatment inhibits the metabolic activity of osteosarcoma cells (SAOS-2) while inducing both the proliferation and the osteogenic differentiation of human preosteoblast cells (HOb) and mesenchymal stem cells. Furthermore, we also propose an in vitro coculture model (SAOS-2 and HOb cell lines) in order to study the effect of 2D bP on inflammatory response related to cancer. On this coculture model, 2D bP may increase anti-inflammatory cytokine generation (i.e., interleukin-10) and inhibit proinflammatory mediators synthesis (i.e., interleukin-6), thus suggesting the opportunity to prevent cancer-related inflammation. Finally, we have demonstrated that 2D bP represents a promising candidate for future regenerative medicine and anticancer applications.

Repeatable Photodynamic Therapy with Triggered Signaling Pathways of Fibroblast Cell Proliferation and Differentiation To Promote Bacteria-Accompanied Wound Healing

Despite the development of advanced antibacterial materials, bacterial infection is still a serious problem for wound healing because it usually induces severe complications and cannot be eradicated completely. Most current materials cannot simultaneously provide antibacterial activity, reusability, and biocompatibility as well as participate in stimulating cell behaviors to promote bacteria-accompanied wound healing. This work fabricated a hybrid hydrogel embedded with two-dimensional (2D) few-layer black phosphorus nanosheets (BPs) via simple electrostatic interaction. Within 10 min, 98.90% Escherichia coli and 99.51% Staphylococcus aureus can be killed rapidly by this hybrid, due to its powerful ability to produce singlet oxygen (¹O₂) under simulated visible light. In addition, this hydrogel also shows a high repeatability; that is, the antibacterial efficacy can still reach up to 95.6 and 94.58% against E. coli and S. aureus, respectively, even after challenging bacteria up to four times repeatedly. In vitro and in vivo results reveal that BPs in this hybrid hydrogel can promote the formation of the fibrinogen at the early stages during the tissue reconstruction process for accelerated incrustation. In addition, BPs can also trigger phosphoinositide 3-kinase (PI3K), phosphorylation of protein kinase B (Akt), and extracellular signal-regulated kinase (ERK1/2) signaling pathways for enhanced cellular proliferation and differentiation. Moreover, the hydrogel causes no appreciable abnormalities or damage to major organs (heart, liver, spleen, lung, and kidney) in rats during the wound healing process. Therefore, this BP-based hydrogel will have great potential as a safe multimodal therapeutic system for active wound healing and sterilization.

A Review of the Relationship Between Parenteral Nutrition and Metabolic Bone Disease

Metabolic bone disease (MBD) refers to the conditions that produce a diffuse decrease in bone density and strength because of an imbalance between bone resorption and bone formation. MBD can be a potential complication in patients receiving chronic parenteral nutrition (PN) therapy and the management of this condition presents a challenge for many clinicians. The etiology of PN-associated MBD is poorly understood, but traditional risk factors can include malnutrition, vitamin and mineral deficiencies, toxic contaminants in the PN solution, concomitant medications, and presence of certain disease states. Although additional studies are warranted to further elucidate the development and management of this condition, the following review discusses some of the important factors that may play a role in the genesis of PN-associated MBD and evaluates some potential strategies for the diagnosis and treatment of this complication.

Refeeding Syndrome and Hypophosphatemia

Hypophosphatemia is a potentially life-threatening complication of reinstating nutrition in a malnourished patient. Refeeding syndrome is a term that refers to various metabolic abnormalities that may complicate carbohydrate administration in subnourished patient populations. Hypophosphatemia is the most well-known, and perhaps most significant, element of the refeeding syndrome and may result in sudden death, rhabdomyolysis, red cell dysfunction, and respiratory insufficiency. This review briefly examines refeeding-induced hypophosphatemia in the hospitalized patient in hopes of making clinicians more aware of this common, but often overlooked, potentially dangerous problem.

Between the utility and hazards of phosphorus through the centuries

Phosphorus has been shown to be a predictor of cardiovascular mortality in kidney disease subjects. Phosphorus was discovered in 1669 and was considered a philosophers stone, it was used as medicament but there were reported deaths after its use. High serum levels of phosphorus are associated with increased risk for cardiovascular disease in the general population in subjects free from chronic kidney disease. Phosphorus can be defined as a useful and hazardous element for public health.

Hereditary hypophosphatemia in Norway: a retrospective population-based study of genotypes, phenotypes, and treatment complications

OBJECTIVE

Hereditary hypophosphatemias (HH) are rare monogenic conditions characterized by decreased renal tubular phosphate reabsorption. The aim of this study was to explore the prevalence, genotypes, phenotypic spectrum, treatment response, and complications of treatment in the Norwegian population of children with HH.

DESIGN

Retrospective national cohort study.

METHODS

Sanger sequencing and multiplex ligand-dependent probe amplification analysis of PHEX and Sanger sequencing of FGF23, DMP1, ENPP1KL, and FAM20C were performed to assess genotype in patients with HH with or without rickets in all pediatric hospital departments across Norway. Patients with hypercalcuria were screened for SLC34A3 mutations. In one family, exome sequencing was performed. Information from the patients' medical records was collected for the evaluation of phenotype.

RESULTS

Twety-eight patients with HH (18 females and ten males) from 19 different families were identified. X-linked dominant hypophosphatemic rickets (XLHR) was confirmed in 21 children from 13 families. The total number of inhabitants in Norway aged 18 or below by 1st January 2010 was 1,109,156, giving an XLHR prevalence of ∼1 in 60,000 Norwegian children. FAM20C mutations were found in two brothers and SLC34A3 mutations in one patient. In XLHR, growth was compromised in spite of treatment with oral phosphate and active vitamin D compounds, with males tending to be more affected than females. Nephrocalcinosis tended to be slightly more common in patients starting treatment before 1 year of age, and was associated with higher average treatment doses of phosphate. However, none of these differences reached statistical significance.

CONCLUSIONS

We present the first national cohort of HH in children. The prevalence of XLHR seems to be lower in Norwegian children than reported earlier.

In vitro evaluation of calcium and phosphorus concentrations in enamel submitted to an in-office bleaching gel treatment containing calcium

The aim of this in vitro study was to evaluate the calcium and phosphorus concentrations in enamel surfaces before, during, and after treatment with in-office 35% hydrogen peroxide bleaching agents with 2% calcium gluconate (WCa) or without calcium gluconate (W). Twenty sound human third molars were divided into 2 groups of 10. The bleaching agents were applied to the tooth surfaces in accordance with the manufacturer's instructions: WCa, 40 minutes per day at 3 sessions with 7-day intervals; W, 3 × 15 minutes per day at 3 sessions with 7-day intervals. Enamel microbiopsies were performed prior to the bleaching treatment, immediately after each bleaching session (first, second, and third applications), and 7 and 14 days following the last bleaching treatment. The concentration levels of calcium and phosphorus in the microbiopsy specimens were recorded spectrophotometrically. There was a statistically significant decrease in the calcium concentration 7 days after the last bleaching treatment, but there was a recovery to baseline values at 14 days, regardless of the bleaching agent used (WCa and W). When W was used, there was no difference in the phosphorus concentration over time. The phosphorus concentration in the WCa group decreased after the third application, showing a significant difference from the W group at this time. However, an increase in the phosphorus concentration was observed in the posttreatment period, and no significant differences were observed between values at baseline and those at 14 days posttreatment. The in-office bleaching gel containing 2% calcium gluconate did not affect the calcium and phosphorus concentrations in enamel as compared to a calcium-free bleaching agent.

[Ultrasound monitoring of consolidation processes in fractures of long tubular bones in osteosynthesis using bioactive implants]

OBJECTIVE

To show the capabilities of ultrasound monitoring to assess consolidation processes in fractures of long tubular bones in the use of bioactive material-containing implants.

MATERIAL AND METHODS

Eighty-two (45.1%) patients whose bone fragments had been fixed with bioactive material-coated plates and 100 (54.9%) patients with bioinert material-coated ones were examined. Consolidation changes were estimated by ultrasound and X-ray studies 2, 4, 6, and 12 months after surgery. Bone metabolic changes were determined by US osteometry 2 months following surgery. Ultrasound data were compared with the biochemical markers: C-terminal telopeptide (CrossLaps) and osteocalcin.

RESULTS AND CONCLUSIONS

Ultrasound monitoring of the rates of consolidation and the time course of changes in bone strength versus the biochemical markers established the positive effect of bioactiveplates on the process of consolidation in fractures of tubular bones and made it possible to consider local osteopenic syndrome to be a prognostically favorable sign of timely callus formation.

Hypophosphatemic rickets caused by a novel PHEX gene mutation in an Indian girl

We report a girl who presented with clinical and biochemical features of hypophosphatemic rickets. Mutational analysis detected a heterozygous nonsynonymous sequence variation in exon 11 of the PHEX gene (NM_000444.4:c.1216T>C, NP_000435.3:p.Cys406Arg). This previously undescribed PHEX mutation is probably the cause of renal phosphate wasting in our patient that resulted in rickets.

[Osteopenia of prematurity--prophylaxis, diagnostics and treatment]

Osteopenia of prematurity is a metabolic bone disease of premature infants with birth weight < 1500 g and gestational age < 32 weeks. Sub-optimal bone matrix, poor skeletal support and an increased risk of fractures characterized the disease. Its importance is determined by relatively high frequency--between 30-70% of infants at risk, multifactorial etiology and impact on early and late morbidity of the newborns. The prevention and treatment of bone disorders are important aspects of the care of preterm babies.

OBJECTIVE

To identify of the risk factors, to determine early diagnostic criteria and to create a prevention program for osteopenia in infants with very low and extremely low birth weight.

MATERIALS AND METHODS

The prospective study includes 39 preterm babies with birth weight below 1500 gr. and < 32 g. w who were admitted to the NICU from September 2011-January 2012. Bone metabolism was monitored by calcium, phosphate and alkaline phosphatise at 2-weeks intervals. Vitamin D levels of the neonates were registered at birth, and at 8th week. PTH was measured at the second and the 8th weeks.

RESULTS

The following biochemical abnormalities were found. Hypophosphatemia in two weeks (P < 1,6 mmol/l), a gradual increase in phosphorus levels and normalization at eight weeks of age. There was a significant positive correlation between 25OHD/phosphorus at eight weeks/r = 0.353/. Significantly elevated levels of parathyroid hormone in eight weeks, correlating with low levels of vitamin D (negative correlation between 25OHD/parathormone r = -0.581). Blood levels of calcium and alkaline phosphatase were in normal limits.

IN CONCLUSION

Risk factors for osteopenia are: the low gestational age and low levels of vitamin D at birth. Biochemical markers of osteopenia are: changes in levels of parathyroid hormone, phosphorus and vitamin D at eight weeks of age. Prevention includes: early supplementation of vitamin D in the risk neonates with individual dose adjustment. Upon biochemical evidence of osteopenia treatment should begin in the second week of life with supplementation of phosphorus, and vitamin D 1320 IU/daily and appropriate physiotherapy.

Epidermal nevus syndrome associated with hypophosphatemic rickets

Epidermal Nevus Syndrome (ENS) is characterized by epidermal nevi associated with abnormalities involving the nervous, skeletal, and other systems. Rarely, hypophosphatemic rickets has been observed in association with epidermal nevi. A patient with ENS with right-sided serpiginous skin lesions, generalized weakness, and diffuse osteopenia associated with hypophosphatemic rickets is described. Medical management was enough to correct the clinical picture. The pathogenic mechanism involved in the onset of hypophosphatemic rickets in ENS is not fully clarified. Different studies suggest that phosphaturia, caused by circulating factor(s), called "phosphatonin(s)," may be secreted by an epidermal nevus. The nature of the phosphaturic factor(s) is not well understood, but elevated levels of circulating FGF-23 were recently reported in one patient with hypophosphatemic rickets. The authors suggest that serum FGF-23 measurement be included in the workup of this kind of rickets because there is growing evidence that in these situations the epidermal nevi produce a phosphaturic factor.

[Systemic responsiveness and the efficiency of antihomotoxic therapy for chronic opisthorchiasis. 3. Responsiveness]

The authors consider systematic responsiveness in chronic opisthorchiasis and a relationship between acute inflammation and responsiveness. A number of regularities that take place in the patho- and sanogenesis of chronic disease in general and that are important in the evaluation of the severity and prognosis of the disease and the efficiency of therapy are demonstrated on a model of severe opisthorchiasis. The reversion syndrome indicative of recovered responsiveness during therapy is described in detail. Differences in the interpretation of the helminthoovoscopic findings are shown in the context of the priority of clinical data.

Factors Affecting the Success Rate of Treatment of Recumbent Dairy Cows Suffering from Hypocalcaemia

We aimed to investigate the ratio of accompanying diseases in cows suffering from clinical hypocalcaemia and their influence on cure rate. In five veterinary practices in different regions of Germany, all recumbent cows around parturition were included in the study for a period of 1 year. After recording the case history a clinical examination was done and a serum sample was taken to measure the concentrations of calcium and phosphorus magnesium, beta-hydroxybutyrate, total bilirubin, cholesterol, urea, and the activities of ASAT, CK, and GLDH. Only cows with hypocalcaemia entered the statistical analysis. Hypocalcaemia was the major cause of recumbency in cows of the second lactation or elder. Muscle damage was the second frequent diagnose in recumbent cows and the major concomitant disease in hypocalcaemic cows. The overall cure rate was between 89.4% and 94.8%. Calcium and phosphorus concentrations did not have an influence on cure rate. Non-cured cows had higher serum activities of CK (p<0.043) and ASAT (p<0.006). Nevertheless, the activities of CK and ASAT were no good predictors of treatment failure because of their low specificity and the high cure rate of the cows in the five practices.

Milk fever and alert downer cows: does hypophosphatemia affect the treatment response?

The purpose of this prospective cohort study was to identify factors that place a dairy cow with uncomplicated milk fever (MF) at significant risk of becoming an alert downer cow (ADC) and to verify if these factors could be used to predict treatment outcome. Recumbent MF cows were examined before treatment and 52 were excluded due to complications. In all, histories and pretreatment serum samples were taken and the serum of 86 cows was analyzed for electrolyte levels (calcium, phosphorus, magnesium, and potassium). In total, 36 of the 86 samples were from ADCs and 50 from animals that responded to MF treatment (MFT). A binary-two-factor logistic model determined that a MF cow with a phosphorus pretreatment level of > or = 0.9 mmol/L was 12 times more likely not to become an ADC than one with a phosphorus level < 0.9 mmol/L (CI: 6.3,23.1). Also, a binary multivariable logistic regression analysis showed that a MF cow with a pretreatment calcium level > or = 1.7 mmol/L was 14 times more likely to become an ADC than one with a serum level < 1.7 mmol/L (CI: 2.0,98). Age and the other serum electrolytes were not statistically significant risk factors at the 0.05 level. The rigorous pretreatment examination and stringent adherence to protocol reduced ADC misclassification and fostered the strong association between single factor serum phosphorus levels and ADCs. By using a cutoff level of serum phosphorus at > or = 0.9 mmol/L, a practitioner could correctly predict that 95% of the MFs would not become ADCs and, therefore, this level would be a useful pretreatment predictor.

Clinico-pathological findings in peripartum dairy cows fed anion salts lowering the dietary cation-anion difference: involvement of serum inorganic phosphorus, chloride and plasma estrogen concentrations in milk fever

In our previous study, it was demonstrated that the administration of anion salts, which slightly lower the dietary cation-anion difference (DCAD), in the prepartum period is safe and effective for preventing milk fever in multiparous cows. In the present study, several clinico-pathological constituents in serum and urine, which might be related to milk fever, were analyzed using stored samples from the previous study to identify clinico-pathological parameters for easily evaluating the efficacy of lowering DCAD and to further investigate the mechanism by which lowering DCAD prevents milk fever. Among the parameters analyzed in the present study, inorganic phosphorus (iP) was involved in milk fever because the serum concentration and urinary excretion of iP were significantly higher in the group of primiparous cows (heifer group), which did not develop hypocalcemia, than those in other groups of multiparous cows. Serum chloride concentrations in the heifer group and the group of multiparous cows fed anion salts (anion group) tended to remain higher than those in other control groups of multiparous cows suggesting that serum chloride concentration may be utilized for evaluating the status of metabolic acidosis and the efficacy of lowerng DCAD in dairy cows fed anion salts. In addition, plasma estradiol-17beta concentration in the heifer group tended to be lower at parturition compared with that in other multiparous groups suggesting that estrogen known as a potent inhibitor of bone resorption may be involved in developing milk fever.

Effect of Lesion Characteristics and Mineralising Solution Type on Enamel Remineralisation in vitro

The aim was to study the effect of lesion preparation technique and solution composition on remineralization of artificial lesions in vitro. Lesions were prepared with similar total mineral loss, but different mineral distribution, i.e., low (14.0) or high R (34.8) values. Lesions from both groups were remineralized (10 days, 37 degrees C) in two different solutions, with similar supersaturation with respect to hydroxyapatite (St), but calcium:phosphate ratios representing either hydroxyapatite stoichiometry or plaque fluid (PF). Remineralization was quantified microradiographically, mineral distribution was compared with natural white-spot lesions. Mineral loss and depth decreased significantly, and surface-zone mineral content (Zmax) increased significantly, in all lesions. Overall there was a significant relationship of decreasing remineralization with increasing Zmax, but not within either lesion type. PF was significantly more efficient than St in high-R lesions, with lesions remineralizing almost completely in PF. Remineralization was not significantly different in PF or St for low-R lesions but in high-R lesions, PF was more efficient than St, possibly through differences in relative saturations with respect to different calcium phosphates. Differences in area:solution ratios and baseline Zmax values may also have explained the different response to PF. Low-R lesions were similar to natural white-spot lesions in terms of mineral distribution, whereas high-R were not. Concluding, both lesion and remineralizing solution type had a marked influence on remineralization. It is proposed that use of low-R lesions would be more appropriate where more physiologically relevant mineral distribution is required, whereas high-R lesions would be appropriate for studying inherent remineralizing efficiency.

Hypophosphatemia and refeeding: a corrective or a preventive attitude?

Hypophosphatemia is a rare but potentially lethal complication of the refeeding of cachectic patients. Up until now a careful monitoring of the serum phosphor level was recommended and the deficit was corrected as needed. Illustrated by two case reports we propose the use of a preventive schedule in patients with a normal renal function. We show that preventively treated patients do not develop hypophosphatemia and thereby avoid serious complications such as sudden death. In the presence of normal kidney function we propose to administer phosphor at 2 x 10 mmol/day orally or between 10 and 30 mmol IV depending on the initial phosphor levels. Further treatment is then adapted to measured levels. In the presence of kidney malfunction we propose to keep the corrective schedule.

Calcium and phosphorus nutrition in preterm infants

Metabolic bone disease is a common event in preterm infants. Between 24 wk gestation and term, the fetus accrues approximately 80% of body Ca, P and Mg. Consequently, preterm infants miss in part or completely the period of greatest mineral accretion. Ca and P requirements in preterm infants are based on demands for matching intrauterine bone mineral accretion rates and on maintenance of normal serum Ca and P concentrations. Daily physical therapy may be a useful adjunct, as it is associated with a significant increase in bone mineral density and content. Osteopenia/rickets of prematurity seems to be a self-resolving disease. However, this does not imply that a period of demineralization is acceptable. While the potential long-term consequences on peak bone mass are unclear at the moment, the short-term benefits include the avoidance of fractures, less marked dolicocephaly and improved linear growth.

Hypophosphataemic osteomalacia due to de Toni-Debre-Fanconi syndrome in a 19-year old girl

Osteomalacia associated with adult onset Fanconi syndrome is thought to result from hypophosphataemia due to renal phosphate loss and relative 1,25-dihydroxyvitamin D3 deficiency. In this disorder, the impaired renal phosphate uptake occurs as part of a generalized tubular defect in association with other features such as bicarbonuria, glycosuria and aminoaciduria. Fanconi syndrome is either hereditary--juvenile form--or is associated with various acquired or heritable diseases. In adults, the disease is similar to the juvenile form, but osteomalacia is a prominent feature. We report a sporadic, adult onset, hypophosphataemia in a 19-year old female patient who presented after puberty complaining of bone and joint pain and difficulty in walking following a minor fall. Radiological examination revealed numerous bilateral fractures of the ribs and pelvis while biochemical investigations showed combination of high phosphate clearance, low serum bicarbonate, glycosuria and glycinuria. Known causes of acquired renal tubular dysfunction were ruled out. The patient was diagnosed as having idiopathic Fanconi syndrome and started on vitamin D3 (Alfacalcidol 1 mg/day) and oral phosphorus (Joulie Solution, 1.5 g/day), which led to resolution of symptoms and an increase in serum phosphate (from 0,54 to 0,71 mmol/l) within few months following the initiation of therapy. However, radiological re-examination showed no signs of fracture healing.

[Minerals in the nutrition of extremely low birth weight infants]

OBJECTIVE

To review the literature on the role of calcium, phosphorus and trace elements in the nutrition of extremely low birth weight infants, considering their importance for metabolism, bone mineralization and as dietary components.

SOURCES OF DATA

MEDLINE, the Cochrane Database of Systematic Reviews and books on nutrition were searched between 1994 and 2004. Original research studies and reviews were selected.

SUMMARY OF THE FINDINGS

Extremely preterm infants are frequently growth-restricted at hospital discharge as a consequence of difficulties in the provision of adequate nutrition. The long-term effects of this growth restriction need to be determined. There is a paucity of studies about the role of minerals, especially micronutrients, in the nutrition of extremely preterm infants. The principal focus of this review was on calcium and phosphorus metabolism, bone mineralization and parenteral and enteral supplementation. A critical evaluation of post-discharge nutrition and its influence upon growth and bone mineralization was presented. Selenium and zinc requirements and the role of selenium as an antioxidant with possible effects on free radical diseases of the preterm infant were discussed.

CONCLUSIONS

Extremely preterm infants have low mineral reserves and, as a consequence, may have deficiencies in the postnatal period if they do not receive parenteral or enteral supplementation. More studies are needed to elucidate the actual requirements and the appropriate supplementation of micronutrients. There are controversies about the outcome and the influence of post-discharge nutrition on bone disease of prematurity.