Upfront plerixafor plus G-CSF versus cyclophosphamide plus G-CSF for stem cell mobilization in multiple myeloma: efficacy and cost analysis study.

Cyclophosphamide plus G-CSF (C+G-CSF) is one of the most widely used stem cell (SC) mobilization regimens for patients with multiple myeloma (MM). Plerixafor plus G-CSF (P+G-CSF) has demonstrated superior SC mobilization efficacy when compared with G-CSF alone and has been shown to rescue patients who fail mobilization with G-CSF or C+G-CSF. Despite the proven efficacy of P+G-CSF in upfront SC mobilization, its use has been limited, mostly due to concerns of high price of the drug. However, a comprehensive comparison of the efficacy and cost effectiveness of SC mobilization using C+G-CSF versus P+G-CSF is not available. In this study, we compared 111 patients receiving C+G-CSF to 112 patients receiving P+G-CSF. The use of P+G-CSF was associated with a higher success rate of SC collection defined as ⩾5 × 10(6) CD34+ cells/kg (94 versus 83%, P=0.013) and less toxicities. Thirteen patients in the C+G-CSF arm were hospitalized owing to complications while none in the P+G-CSF group. C+G-CSF was associated with higher financial burden as assessed using institutional-specific costs and charges (P<0.001) as well as using Medicare reimbursement rates (P=0.27). Higher rate of hospitalization, increased need for salvage mobilization, and increased G-CSF use account for these differences.

Retrospective comparison of the effects of filgrastim and pegfilgrastim on the pace of engraftment in auto-SCT patients.

The high doses of chemotherapy used for the preparatory regimens before autologous blood or marrow stem cell transplantation leave patients at risk for neutropenic complications. The administration of filgrastim post transplant reduces the time to neutrophil recovery and therefore has become a standard practice at many institutions. In 2006, we implemented a practice change from filgrastim to pegfilgrastim. We present data on 164 consecutive patients (82 patients who received filgrastim compared with 82 patients who received pegfilgrastim) who received an auto-SCT between January 2006 and November 2007. Patients who received pegfilgrastim had faster engraftment (9.6 days compared with 10.9 days, P<0.0001), a lower incidence of febrile neutropenia (59% compared with 78%, P=0.015), as well as shorter hospital stay, fewer days of treatment with i.v. antibiotics (6.3 days compared with 9.6 days, P=0.006), and fewer radiographic tests, which translated to an estimated total cost savings of over $8000 per patient. Overall, there were no differences in toxicity with these two agents. We conclude that a single dose of pegfilgrastim is a safe and efficacious alternative to daily injections of filgrastim and can be a cost-effective approach in auto-SCT patients.

Conformation and translational diffusion of a xanthan polyelectrolyte chain: Brownian dynamics simulation and single molecule tracking.

In our recent Brownian dynamics (BD) simulation study, the structure and dynamics of anionic polyelectrolyte xanthan in bulk solution as well as confined spaces of slitlike channel were examined by applying a coarse-grained model with nonlinear bead-spring discretization of a whole chain [J. Jeon and M.-S. Chun, J. Chem. Phys. 126, 154904 (2007)]. This model goes beyond other simulations as they did not consider both long-range electrostatic and hydrodynamic interactions between pairs of beads. Simulation parameters are obtained from the viscometric method of rheology data on the native and sonicated xanthan polysaccharides, which have a contour length less than 1 microm . The size of the semiflexible polyelectrolyte can be well described by the wormlike chain model once the electrostatic effects are taken into account by the persistence length measured at a long length scale. For experimental verifications, single molecule visualization was performed on fluorescein-labeled xanthan using an inverted fluorescence microscope, and the motion of an individual molecule was quantified. Experimental results on the conformational changes in xanthan chain in the electrolyte solution have a reasonable trend to agree with the prediction by BD simulations. In the translational diffusion induced by the Debye screening effect, the simulation prediction reveals slightly higher values compared to those of our measurements, although it agrees with the literature data. Considering the experimental restrictions, our BD simulations are verified to model the single polyelectrolyte well.

Primary care productivity and the health care safety net in New York City.

Urban safety net providers are under pressure to improve primary care productivity. In a survey of ambulatory care facilities in New York City, productivity (measured as the number of primary care visits per provider hour) increases with exam rooms per physician but has no association with computerized information systems or tightly controlled reimbursement. Also, sample facilities rely heavily on residents, which makes these facilities sensitive to medical education policies and raises questions about quality of care for the poor. We conclude that urban safety net providers will have difficulty making the productivity improvements demanded by a more competitive health system.