Effect of eldecalcitol, an active vitamin D analog, on hip structure and biomechanical properties: 3D assessment by clinical CT.

The effects of an active vitamin D analog, eldecalcitol (ELD), on bone mineral density (BMD), bone geometry, and biomechanical properties of the proximal femur were investigated by using clinical CT. The subjects - a subgroup of a recent randomized, double-blind study comparing anti-fracture efficacy of ELD with alfacalcidol (ALF) - constituted 193 ambulatory patients with osteoporosis (189 postmenopausal women and 4 men aged 52-85years, average±SD: 70.9±6.92years) enrolled at 11 institutions. Multidetector-row CT data was acquired at baseline and at completion of 144weeks\u27 treatment. Cross-sectional densitometric and geometric parameters of the femoral neck were derived from three-dimensional CT data. Biomechanical properties including cross-sectional moment of inertia (CSMI), section modulus (SM) and buckling ratio (BR) of the femoral neck, and CSMI of the femoral shaft were also calculated. We found that, 1) with respect to the femoral neck cross-sectional parameters (total bone), in the ALF group, volumetric BMD (vBMD) decreased but bone mass was maintained and cross-sectional area (CSA) increased. In contrast, ELD maintained vBMD with a significant increase in bone mass and a trend toward increased CSA. 2) With respect to the femoral neck cross-sectional parameters (cortex), cortical thickness decreased in the ALF group, but was maintained in the ELD group. In the ALF group, vBMD and bone mass increased, and CSA was maintained. In the ELD group, vBMD, CSA, and bone mass increased. 3) With respect to the biomechanical properties of the femoral neck, ELD improved CSMI and SM to a greater extent than did ALF. BR increased in both the ALF and ELD groups. 4) With respect to the femoral shaft parameters, overall the results of bone geometry and CSMI of the femoral shaft were very consistent with the results for the femoral neck; however, cortical vBMD of the femoral shaft decreased significantly in both the ELD and ALF groups. In conclusion, our longitudinal analysis of hip geometry by clinical CT revealed the unexpected potential of ELD to increase cortical CSA, vBMD, and bone mass, and to maintain cortical thickness, probably through the more potent effect of ELD in mitigating endocortical bone resorption than ALF. By improving the biomechanical properties of the proximal femur, ELD may have the potential to reduce the risk of hip fractures

Long-term Observation of Osteomalacia Caused by Adefovir-Induced Fanconi’s Syndrome

A 64-year-old man suffering polyarthralgia and bone pain was referred to our hospital. Renal dysfunction, hypophosphatemia and increased levels of bone alkaline phosphatase were found. The patientʼs serum creatinine level had gradually increased after the initiation of adefovir dipivoxil administration for hepatitis B. In agreement with multifocal uptakes of bone scintigraphy, iliac bone biopsy revealed an abnormal increase in osteoid tissues. Reducing the dose of adefovir and initiating the administration of eldecalcitol were effective for reducing proteinuria and glucosuria, and for ameliorating bone pain with an increase in serum phosphate level. This case first showed a clinical course of hypophosphatemic osteomalacia caused by secondary Fanconiʼs syndrome for 8 years after adefovir administration. Early diagnosis is important for the reversibility of bone damage and for a better renal prognosis

Oral manifestation and salivary changes in renal patients undergoing hemodialysis

Salivary changes in hemodialysis patients may result in various oral manifestations. This research intended to determine oral manifestations and some salivary markers in hemodialysis patients. This cross-sectional study was conducted on 30 hemodialysis patients (the patient group) and 30 healthy individuals (the control group). Saliva urea and calcium levels and pH values of the participants were measured, and oral manifestations such as pale mucosa, xerostomia, halitosis, changes in the sense of taste, increased calculus formation, gingival bleeding, etc. were recorded in the information collection form. The data was analyzed using T-test and chi-square, and p<0.05 was considered to be significant. The mean salivary urea level and pH value in the patient group were significantly higher compared to those of the control group (P<0.05), but there were no significant differences between the two groups with respect to salivary calcium. Halitosis, xerostomia, and increased calculus were the most prevalent manifestations, and gum bleeding was the least prevalent among the patients. Advanced chronic renal insufficiency can increase salivary urea level, pH value, halitosis, xerostomia, and calculus formation, and may cause pale mucosa

Vitamin D-VDR (vitamin D receptor) alleviates glucose metabolism reprogramming in lipopolysaccharide-induced acute kidney injury

Background: Our previous study showed that vitamin D (VD)-vitamin D receptor (VDR) plays a nephroprotective role in lipopolysaccharide (LPS)-induced acute kidney injury (AKI). Recently, glucose metabolism reprogramming was reported to be involved in the pathogenesis of AKI.Objective: To investigate the role of VD-VDR in glucose metabolism reprogramming in LPS-induced AKI.Methods: We established a model of LPS-induced AKI in VDR knockout (VDR-KO) mice, renal proximal tubular-specific VDR-overexpressing (VDR-OE) mice and wild-type C57BL/6 mice. In vitro, human proximal tubular epithelial cells (HK-2 cells), VDR knockout and VDR overexpression HK-2 cell lines were used.Results: Paricalcitol (an active vitamin D analog) or VDR-OE reduced lactate concentration, hexokinase activity and PDHA1 phosphorylation (a key step in inhibiting aerobic oxidation) and simultaneously ameliorated renal inflammation, apoptosis and kidney injury in LPS-induced AKI mice, which were more severe in VDR-KO mice. In in vitro experiments, glucose metabolism reprogramming, inflammation and apoptosis induced by LPS were alleviated by treatment with paricalcitol or dichloroacetate (DCA, an inhibitor of p-PDHA1). Moreover, paricalcitol activated the phosphorylation of AMP-activated protein kinase (AMPK), and an AMPK inhibitor partially abolished the protective effect of paricalcitol in LPS-treated HK-2 cells.Conclusion: VD-VDR alleviated LPS-induced metabolic reprogramming in the kidneys of AKI mice, which may be attributed to the inactivation of PDHA1 phosphorylation via the AMPK pathway

Muscle dysfunction during physical activity – muscle rhabdomyolysis

Rhabdomyolysis is the breakdown of striated muscle fibers, which results in the release of muscle cell components into the peripheral circulation. Most cases of rhabdomyolysis are the result of trauma, often a consequence of seizures, alcohol and drug abuse but in some cases it is associated with very intensive physical activity. Proper understanding of muscle rhabdomyolysis can contribute to better preparation of sportsman for the intensive physical activity and to protect his body from episodes of extensive muscle breakdown and prevent their occurrence.            This article is an attempted to summarize and show medical and biochemical basics of muscle rhabdomyolysis with a special attention to the episodes that occurs during physical activity. It may help in prevention of such cases in the future and protects the body of a sportsmen