A reference high-pressure CO2 adsorption isotherm for ammonium ZSM-5 zeolite: results of an interlaboratory study

This paper reports the results of an international interlaboratory study led by the National Institute of Standards and Technology (NIST) on the measurement of high-pressure surface excess carbon dioxide adsorption isotherms on NIST Reference Material RM 8852 (ammonium ZSM-5 zeolite), at 293.15 K (20 °C) from 1 kPa up to 4.5 MPa. Eleven laboratories participated in this exercise and, for the first time, high-pressure adsorption reference data are reported using a reference material. An empirical reference equationn e x = d ( 1 + exp [ - ln ( P ) + a / b ] ) c , [n ex -surface excess uptake (mmol/g), P-equilibrium pressure (MPa), a = -6.22, b = 1.97, c = 4.73, and d = 3.87] along with the 95% uncertainty interval (U k = 2 = 0.075 mmol/g) were determined for the reference isotherm using a Bayesian, Markov Chain Monte Carlo method. Together, this zeolitic reference material and the associated adsorption data provide a means for laboratories to test and validate high-pressure adsorption equipment and measurements. Recommendations are provided for measuring reliable high-pressure adsorption isotherms using this material, including activation procedures, data processing methods to determine surface excess uptake, and the appropriate equation of state to be used.

Preparation and characterization of SNO-PEG-hemoglobin as a candidate for oxygen transporting material

Acellular hemoglobin (Hb) derivates developed as oxygen carriers are known to cause hypertensive reactions due to their nitric oxide (NO) scavenging action. To modulate this undesired activity, we have developed a new Hb derivative, s-nitrosylated polyethylene glycol (PEG)-modified hemoglobin (SNO-PEG-Hb), which can deliver oxygen and NO. After human Hb was modified with PEG to increase its molecular weight, the free sulfhydryl groups of Hb were s-nitrosylated with s-nitrosoglutathione. Administration of unmodified Hb into anesthetized rats caused a hypertensive reaction, while s-nitrosylated Hb derivatives such as SNO-Hb and SNO-PEG-Hb did not raise blood pressure. The plasma half-lives of heme and NO bound to SNO-PEG-Hb were 11.5 and 2.4 hours respectively, indicating that the s-nitrosylated Hb derivative may act as a slow-releasing agent for NO. Based on these findings, SNO-PEG-Hb is a useful candidate for a blood substitute and tool for oxygen therapeutics.

Effects of Lanthanum Carbonate on Coronary Artery Calcification and Cardiac Abnormalities After Initiating Hemodialysis

It is known that calcium-containing phosphate binders are more closely associated with the progression of vascular calcification than non-calcium-containing phosphate binders. In this study, we investigated the effect of the non-calcium-containing phosphate binder, lanthanum carbonate on the progression of coronary artery calcification and cardiovascular abnormalities compared to that of calcium-containing phosphate binder in chronic kidney disease patients during the early period after initiating hemodialysis. This was a randomized open-label study in which patients were divided into the calcium carbonate or lanthanum carbonate group. We evaluated blood samples, coronary artery calcification using high-resolution computed tomography, and cardiac abnormalities using echocardiography prior to and after initiating hemodialysis. Cardiac dimension and systolic function were significantly improved in the lanthanum carbonate group compared to those in the calcium carbonate group. Although statistically significant differences were not observed in all the patients, only among patients with moderate coronary artery calcification, the changes in coronary artery calcification score at 18 months were significantly smaller in the lanthanum carbonate group than those in the calcium carbonate group. The percent change in coronary artery calcification at 18 months was significantly correlated with the serum fibroblast growth factor 23 levels at 18 months (r = 0.245, P < 0.05). This significant correlation was particularly strong in patients with moderate coronary artery calcification (r = 0.593, P < 0.001). Our study suggests that lanthanum carbonate ameliorates cardiac abnormalities, and may slow coronary artery calcification development in patients with moderate coronary artery calcification, during the early period following hemodialysis initiation.

Newly Developed Rat Model of Chronic Kidney Disease-Mineral Bone Disorder

Aim: Chronic kidney disease–mineral bone disorder (CKD–MBD) is associated with all-cause and cardiovascular morbidity and mortality in patients with CKD. Thus, elucidating its pathophysiological mechanisms is essential for improving the prognosis. We evaluated characteristics of CKD–MBD in a newly developed CKD rat model.

Methods: We used male Sprague–Dawley (SD) rats and spontaneously diabetic Torii (SDT) rats, which are used as models for nonobese type 2 diabetes. CKD was induced by 5/6 nephrectomy (Nx). At 10 weeks, the rats were classified into six groups and administered with a vehicle or a low- or high-dose paricalcitol thrice a week. At 20 weeks, the rats were sacrificed; blood and urinary biochemical analyses and histological analysis of the aorta were performed.

Results: At 20 weeks, hemoglobin A1c (HbA1c) levels, blood pressure, and renal function were not significantly different among the six groups. Serum calcium and phosphate levels tended to be higher in SDT-Nx rats than in SD-Nx rats. The urinary excretion of calcium and phosphate was significantly greater in SDT-Nx rats than in SD-Nx rats. After administering paricalcitol, serum parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) levels were significantly higher in SDT-Nx rats than in SD-Nx rats. The degree of aortic calcification was significantly more severe and the aortic calcium content was significantly greater in SDT-Nx rats than in SD-Nx rats.

Conclusions: We suggest that our new CKD rat model using SDT rats represents a useful CKD–MBD model, and this model was greatly influenced by paricalcitol administration. Further studies are needed to clarify the detailed mechanisms underlying this model.

A Case of Fibrillary Glomerulonephritis with Fibril Deposition in the Arteriolar Wall and a Family History of Renal Disease

Herein, we report a case of fibrillary glomerulonephritis (FGN). FGN usually shows non-amyloidal fibrils in the mesangium and glomerular capillary walls on electron microscopy. Inherited cases of FGN have been reported in only 3 families, and the suspected genetic form was autosomal dominant. In the present case, the deposition of microfibrils in the arteriolar wall as well as the glomerulus is unique. Our patient's father died of nephrotic syndrome, and his elder brother had a biopsy-proven glomerulopathy. The histological findings of the brothers are similar to mesangial proliferative glomerulonephritis and resemble each other. Therefore, our case is presumed to be familial FGN. Additionally, herein, we review the literature and reconsider the histological and clinical characters of FGN.

Comparison of the effects of novel vitamin D receptor analog VS-105 and paricalcitol on chronic kidney disease-mineral bone disorder in an experimental model of chronic kidney disease

When using vitamin D, the most important clinical problems are hypercalcemia, hyperphosphatemia, and vascular calcification. VS-105 is a novel vitamin D receptor (VDR) analog. In the present study, we compared the effects of VS-105 and paricalcitol on chronic kidney disease-mineral bone disorder (CKD-MBD) in a CKD rat model. We used male Sprague-Dawley (SD) rats and performed 5/6 nephrectomy at 8-9 weeks. At 10 weeks, the rats were classified into five groups and administered vehicle, low-dose paricalcitol (LP, 0.1μg/kg), high-dose paricalcitol (HP, 0.3μg/kg), low-dose VS-105 (LV, 0.2μg/kg), and high-dose VS-105 (HV, 0.6 μg/kg) three times a week for 10 weeks. There were no significant differences in blood pressure or renal function among the five groups. Alhough serum calcium levels were comparable between the LP and LV groups, they were higher in the HP group than in the HV group. Serum phosphate levels were higher in the paricalcitol-treated groups than in the VS-105-treated groups and paticularly higher in the HP group than in the other groups. The urinary excretion of phosphate was greater in the VS-105-treated groups than in the paricalcitol-treated groups. Serum parathyroid hormone (PTH) levels decreased and serum fibroblast growth factor-23 (FGF23) levels were elevated after administering paricalcitol and VS-105; however, serum FGF23 levels were remarkably elevated in the paricalcitol-treated groups. Further biochemical analyses revealed that the calcium content of the aorta was higher in the paricalcitol-treated groups than in the VS-105-treated group. VDR and Klotho expression in the kidney was significantly higher in the VS-105-treated groups than in the paricalcitol-treated groups although both agents increased these expressions. Our data suggest that VS-105 had a lesser effect on CKD-MBD than paricalcitol except in the case of serum PTH levels. The mechanism appears to be associated with the difference in VDR and Klotho expression.

The Effects of Plasma Exchange on Severe Vasculitis with Diffuse Alveolar Hemorrhage

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis is a life-threatening disease characterized by rapidly progressive glomerulonephritis (RPGN) and diffuse alveolar hemorrhage (DAH). Glucocorticoids and immunosuppressants are commonly used to treat this disease but may induce irreversible side effects, particularly in elderly patients. We herein report the case of a 76-year-old woman with RPGN. After methylprednisolone pulse therapy, DAH occurred, and she required ventilatory support. After plasma exchange, her serum creatinine level improved, and she was discharged with home oxygen therapy. Immunosuppressive agents other than glucocorticoids were not required. In conclusion, plasma exchange with glucocorticoid therapy may be effective in treating severe ANCA-associated vasculitis in elderly patients.

Serum FGF23 levels may not be associated with serum phosphate and 1,25-dihydroxyvitamin D levels in patients with Fanconi syndrome-induced hypophosphatemia

Fibroblast growth factor 23 (FGF23) is regulated by sustained phosphate supplementation and restriction. However, few studies have investigated FGF23 levels in patients with Fanconi syndrome. Therefore, we evaluated intact and C-terminal FGF23 and FGF23-associated parameters in four patients with Fanconi syndrome. Serum intact and C-terminal FGF23 levels were extremely low. Although serum phosphate and 1,25-dihydroxyvitamin D levels improved to or above the normal range within 1 year of treatment with oral phosphate and calcitriol, serum FGF23 levels remained low. Serum FGF23 levels in patients with Fanconi syndrome might be regulated by novel factors other than serum phosphate and 1,25-dihydroxyvitamin D levels.

[Impact of neutron radiation on the viability of tumor cells cultured in the presence of boron-10 isotope]

OBJECTIVE

To investigate the impact of a neutron beam formed with the accelerator-based epithermal neutron source designed at the G.I. Budker Institute of Nuclear Physics (INP) on the viability of human and animal tumor cells cultured in the presence of boron-10 isotope.

MATERIAL AND METHODS

Human U251 and T98G glioma cells and Chinese hamster CHO-K1 and V-79 cells were incubated at various concentrations in the culture medium containing 10B-enriched L-boronophenylalanine. The cells were irradiated with a neuron beam using the accelerator-based epithermal neuron source. A clonogenic assay was used to evaluate the viability of the irradiated cells. The absorbed doses obtained from elastic scattering of fast neutrons by substance nuclei and the doses obtained from boron neutron capture were calculated using the NMS code. The absorbed doses of gamma-radiation were measured with a mixed radiation dosimeter.

RESULTS

The viability of boron-containing and intact human U251 and T98G cell lines and Chinese hamster CHO-K1 and V-79 cells was analyzed after neutron beam radiation. Irradiation of all four cell lines were cultured in the presence of 10B was shown to reduce their colony-forming capacity compared with the control. Elevated boron levels in the culture medium resulted in a significant decrease in the proportion of survived cells. Radiation had the most pronounced impact on the proliferative capacity of the human U251 glioma cell lines.

CONCLUSION

The cultures of human tumor cells and mammalian cells demonstrated that the neutron beam formed with the accelerator-based epithermal neutron source designed at the INP, was effective in reducing the viability of tumor cells in the presence of 10B.

[Efficacy and safety of selective estrogen receptor modulators in patients with advanced chronic kidney disease]

Selective estrogen receptor modulators(SERMs)have beneficial effects on the improvement of bone mineral density of the spine and hip, and decrease the vertebral fracture in postmenopausal women. Similar to patients with advanced chronic kidney disease, including dialysis patients, however, SERMs cannot decrease the risk of hip fracture, which is extremely high in Japanese dialysis patients. One of the most important disadvantages of SERMs is an increase in the risk of venous thromboembolic events and fatal stroke in high-risk groups of the Framingham Stroke Risk Score. On the other hand, SERMs may be used in unique osteoporosis drugs for reducing the incidence and progression of breast cancer. Moreover, SERMs attenuate oxidative stress and may lessen the deterioration of kidney function in patients with chronic kidney disease. The evidences for the efficacy and safety of SERMs in patients with advanced chronic kidney disease are insufficient, and knowledge concerning the selection and indication of osteoporosis drugs for those patients need to be developed.