Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

The $B^0$-$\bar B^0$ oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives $\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)}$ ps$^{-1}$.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

Cytokine accumulation in osteitis fibrosa of renal osteodystrophy

Bone marrow fibrosis occurs in association with a number of pathological states. Despite the extensive fibrosis that sometimes characterizes renal osteodystrophy, little is known about the factors that contribute to marrow accumulation of fibrous tissue. Because circulating cytokines are elevated in uremia, possibly in response to elevated parathyroid hormone levels, we have examined bone biopsies from 21 patients with end-stage renal disease and secondary hyperparathyroidism. Bone sections were stained with antibodies to human interleukin-1alpha (IL-1alpha), IL-6, IL-11, tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-ß (TGF-ß) using an undecalcified plastic embedding method. Intense staining for IL-1alpha, IL-6, TNF-alpha and TGF-ß was evident within the fibrotic tissue of the bone marrow while minimal IL-11 was detected. The extent of cytokine deposition corresponded to the severity of fibrosis, suggesting their possible involvement in the local regulation of the fibrotic response. Because immunoreactive TGF-ß and IL-6 were also detected in osteoblasts and osteocytes, we conclude that selective cytokine accumulation may have a role in modulating bone and marrow cell function in parathyroid-mediated uremic bone disease

Chronic kidney disease Markov model comparing paricalcitol to calcitriol for secondary hyperparathyroidism: A US perspective

Objective: The objective of this study was to determine the cost effectiveness of paricalcitol versus calcitriol for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease in the United States setting. Methods: A Markov process model was developed employing data sources from the published literature, paricalcitol clinical trials and observational studies, official US price/tariff lists and national population statistics. The comparator was calcitriol, a non-selective vitamin D receptor activator (VDRA) medication. The primary perspective of the study was that of the third-party payer in the US. The efficacy outcomes (reduction in secondary hyperparathyroidism (SHPT), reduction in proteinuria, complications and mortality) were extrapolated to: number of life-years gained (LYG) and number of quality-adjusted life-years (QALYs). Clinical and economic outcomes were discounted at 3.5%. Results: The reference case analysis was a 10-year time horizon based on a comparison of paricalcitol with calcitriol, which is started in chronic kidney disease (CKD) stage 3 and continued in CKD stage 4 and CKD stage 5. The use of paricalcitol leads to a cost saving of US$1941. The inclusion of indirect costs leads to a cost saving of US$2528. The use of paricalcitol leads to an increase in life-years gained (0.47 years) and a gain in QALYs (0.43). The use of paricalcitol results in a dominant outcome from the perspective of the third-party payer, as well as from the societal perspective. One-way sensitivity analyses and probabilistic sensitivity analyses confirmed the robustness of the model. Conclusion: This model showed that the favorable clinical benefit of paricalcitol results in positive short and long-term health economic benefits. This study suggests that the use of paricalcitol in patients with early chronic kidney disease may be cost-effective from the third-party payer perspective in the US versus calcitriol. Additional comparative studies are necessary to validate these results

Prevalence of abnormal serum vitamin D, PTH, calcium, and phosphorus in patients with chronic kidney disease: Results of the study to evaluate early kidney disease

Abnormalities of mineral metabolism occur early in chronic kidney disease. Quantification of the prevalence of these abnormalities has not been described using current assays nor in large unselected populations. This outpatient cohort cross-sectional study was conducted in 153 centers, (71% primary care practices). Blood for parathyroid hormone (PTH), vitamin D metabolites, creatinine, calcium (Ca), and phosphorus (P) were drawn between June and October 2004. Low 1,25-dihydroxyvitamin D (1,25 OH2 D3) was defined as <22pg/ml. The 1814 patients had a mean age of 71.1 years old; 48% had diabetes mellitus (DM). Low 1,25 OH2 D3 was evident at all estimated glomerular filtration rate (eGFR) levels: 13% in those with eGFR >80ml/min, >60% in those with eGFR <30ml/min. High PTH (>65pm/dl) occurred in 12% with eGFR >80ml/min. Serum Ca and P were normal until eGFR was <40ml/min. Significant differences in the mean and median values of 1,25 OH2 D3, PTH, but not 25(OH)D3 levels, were seen across deciles of eGFR (P<0.001). Multivariate analysis revealed that DM, increased urinary albumin/creatinine ratio and lower eGFR predicted lower values of 1,25 OH2 D3. A high prevalence of mineral metabolite abnormalities occurs in a large unreferred US cohort. Low 1,25 OH2 D3 and elevated PTH are common at higher eGFR than previously described. As bone, cardiovascular disease, and mineral metabolite are correlated; further studies are necessary to determine the importance of these findings relative to outcomes