Tubulin from bovine brain was polymerized in vitro using a variety of assembly conditions. Many of the formed microtubules were shown to contain 14 wall protofilaments. The number of microtubules containing 14 protofilaments increased with consecutive repetitions of cold-dissociation followed by reassembly in vitro.
Subunit structure in the walls of sectioned microtubules was first noted by Ledbetter and Porter (6), who clearly showed that certain microtubules of plant meristematic cells have 13 wall protofilaments when seen in cross section. Earlier, protofilaments of microtubular elements had been described in negatively stained material, although exact counts of… (More)
High-dose therapy with stem cell rescue is a treatment option for patients with advanced solid tumors. Although this approach has promise for some pediatric cancers, especially neuroblastoma, it is limited by the risk of relapse posttransplant as well as concern about possible reinfused tumor cells in autologous stem cell products. Antiangiogenic agents… (More)