Successful mobilization of peripheral blood HPCs with G-CSF alone in patients failing to achieve sufficient numbers of CD34+ cells and/or CFU-GM with chemotherapy and G-CSF.

BACKGROUND: Mobilization with chemotherapy and G-CSF may result in poor peripheral blood HPC collection, yielding <2 x 10(6) CD34+ cells per kg or <10 x 10(4) CFU-GM per kg in leukapheresis procedures. The best mobilization strategy for oncology patients remains unclear. STUDY DESIGN AND METHODS: In 27 patients who met either the CD34 (n = 3) or CFU-GM (n = 2) criteria or both (n = 22), the results obtained with two successive strategies-that is, chemotherapy and G-CSF at 10 microg per kg (Group 1, n = 7) and G-CSF at 10 microg per kg alone (Group 2, n = 20) used for a second mobilization course-were retrospectively analyzed. The patients had non-Hodgkin's lymphoma (5), Hodgkin's disease (3), multiple myeloma (5), chronic myeloid leukemia (1), acute myeloid leukemia (1), breast cancer (6), or other solid tumors (6). Previous therapy consisted of 10 (1-31) cycles of chemotherapy with additional chlorambucil (n = 3), interferon (n = 3), and radiotherapy (n = 7). RESULTS: The second collection was undertaken a median of 35 days after the first one. In Group 1, the results of the two mobilizations were identical. In Group 2, the number of CD34+ cells per kg per apheresis (0.17 [0.02-0.45] vs. 0.44 [0.11-0.45], p = 0. 00002), as well as the number of CFU-GM (0.88 [0.00-13.37] vs. 4.19 [0.96-21.61], p = 0.00003), BFU-E (0.83 [0.00-12.72] vs. 8.81 [1. 38-32.51], p = 0.00001), and CFU-MIX (0.10 [0.00-1.70] vs. 0.56 [0. 00-2.64], p = 0.001134) were significantly higher in the second peripheral blood HPC collection. However, yields per apheresis during the second collection did not significantly differ in the two groups. Six patients in Group 1 and 18 in Group 2 underwent transplantation, and all but one achieved engraftment, with a median of 15 versus 12 days to 1,000 neutrophils (NS), 22 versus 16 days to 1 percent reticulocytes (NS), and 26 versus 26 days to 20,000 platelets (NS), respectively. However, platelet engraftment was particularly delayed in many patients. CONCLUSION: G-CSF at 10 microg per kg alone may constitute a valid alternative to chemotherapy and G-CSF to obtain adequate numbers of peripheral blood HPCs in patients who previously failed to achieve mobilization with chemotherapy and G-CSF. This strategy should be tested in prospective randomized trials

Diameter variations of irregular fibers under different tensions

The cross-section area of animal fibers varies along the fiber length, and this geometrical irregularity has a major impact on the mechanical properties of those fibers. In practice fibers are often subjected to tensile stresses during processing and application, which may change fiber cross-section area. It is thus necessary to examine geometrical irregularity of fibers under tension. In this study, scoured animal fibers were subjected to different tensile loading using a Single Fiber Analyzer (SIFAN) instrument. The 3D images of the fiber specimens were first constructed, and then along-fiber diameter irregularities of the specimens were analyzed for different levels of tensile loading. The changes in effective fineness of the fiber specimens were also discussed. The results indicate that for the wool fibers examined, there is considerable discrepancy in the fiber diameter results obtained from the commonly used single scan along fiber length and that from multiple scans at different rotational angles, and that the diameter variation along fiber length increases as fiber tension increases. The results also show that when diameter reduction treatments are applied to wool by stretching, the reduced average fiber diameter is associated with an increase in both within-fiber and between-fiber diameter variations. So in terms of effective fineness, the change is much smaller than the difference between the average diameters of the parent and treated wool. These results have significant implications for improving the accuracy of fiber diameter measurement and evaluation. <br /

The limiting irregularity of single wool fibers

Fiber irregularity affects fiber mechanical properties. This study has, for the first time, introduced the concept of limiting irregularity to single wool fibers. The limiting irregularity is the minimum variation in fiber cross sectional area that can be expected of a single wool fiber, assuming a random length-wise distribution of its constituent cortical cells. Cortical cells were extracted from merino wool fibers and their dimensions were measured from SEM images to calculate their cross sectional area variations both between cortical cells and within cortical cells, and to work out the average number of cortical cells in the cross section of wool fibers of a given diameter. Single wool fibers were also measured at 5 &micro;m interval along length for fiber diameter variations. These variations were found to be larger than that based on fiber limiting irregularity.<br /