Trabecular bone volume and osteoprotegerin expression in uremic rats given high calcium

Calcium (Ca)-containing phosphate binders have been recommended for the treatment of hyperphosphatemia in children with chronic kidney disease. To study the effects of high Ca levels on trabecular bone volume (BV) and osteoprotegerin (OPG) expression in uremic young rats, a model of marked overcorrection of secondary hyperparathyroidism was created by providing a diet of high Ca to 5/6 nephrectomized young rats (Nx-Ca) for 4 weeks. The results of chondrocyte proliferation and apoptosis, osteoclastic activity, OPG expression and BV were compared among intact rats given the control diet, intact rats given a high Ca diet and 5/6 nephrectomized rats given the control diet (Nx-Control) and the high Ca diet (Nx-Ca). Ionized Ca levels were higher and parathyroid hormone levels were lower in Nx-Ca rats than in the other groups. Final weight, final length and final tibial length of Nx-Ca rats were significantly less than those of the other groups, although the length gain did not differ among the groups. The hypertrophic zone width was markedly enlarged in Nx-Ca rats. Chondrocyte proliferation rates did not differ among the groups, whereas osteoclastic activity was decreased in Nx-Ca rats compared with the Nx-Control animals. The OPG expression and BV were increased in Nx-Ca rats compared with the Nx-Control rats. Increased BV should improve bone strength, whereas disturbance of osteoclastogenesis interferes with bone remodeling. Bone quality has yet to be determined in high Ca-fed uremic young rats

Serum osteoprotegerin is markedly increased and may contribute to decreased blood T cell count in hemodialysis patients

Acquired immunity is impaired in hemodialysis (HD) patients, and decreased T cell number may contribute. Receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) are expressed in cells of the immune system and affect T cell development, homeostasis and proliferation. Serum levels of RANKL and OPG and their relation to blood T cell number were evaluated in HD patients. Thirty-four HD patients and 20 healthy controls participated in the study. Serum RANKL and OPG were measured by ELISA and T cell number was assessed by flow cytometry. Median RANKL concentration did not differ between HD patients and healthy volunteers (300.00 pmol/L; range, 3,340.00 vs. 330.00 pmol/L; range, 440.00 pmol/L; p = 0.528). Median OPG was markedly higher in HD patients than in healthy volunteers (13.12 +/- A 4.71 vs. 4.71 +/- A 0.93 pmol/L, p < 0.001). The T cell count was significantly lower in HD patients than in healthy controls (1,177.00 +/- A 567.71 vs. 1,519.80 +/- A 594.96 cells/mm(3), p = 0.044). In HD patients, blood T cell number was correlated positively with serum RANKL (rho = 0.462, p = 0.007) and negatively to serum OPG (r = -0.449, p = 0.008). Serum OPG concentration is markedly increased in HD patients and may contribute to decreased blood T cell count and impaired acquired immunity that characterizes this population

Kreislaufstillstand in besonderen Situationen

Truhlář A, Deakin CD, Soar J, et al. Kreislaufstillstand in besonderen Situationen. Notfall + Rettungsmedizin. 2015;18(8):833-903