Chiron Corporation

About: Chiron Corporation is a based out in . It is known for research contribution in the topics: Antigen & Hepatitis C virus. The organization has 1973 authors who have published 1969 publications receiving 172330 citations.

Structure-function studies on human macrophage colony-stimulating factor (M-CSF)

Abstract: M-CSF (CSF-1) can be produced in a variety of structural forms that may affect function in vivo. Truncated, nonglycosylated forms of recombinant M-CSF (rM-CSF) from E. coli have been refolded in vitro in high yield and shown to be functionally equivalent in vitro to glycosylated rM-CSF secreted from mammalian cells. An N-terminal domain of 149 amino acids is produced by all of the known M-CSF mRNA splice variants and is the region responsible for bioactivity observed in vitro. Heterodimeric rM-CSFs from different splice variants containing this domain were produced in pure form by refolding in vitro, and are fully active, but have yet to be observed in vivo. The circulating half-life of truncated M-CSF forms injected intravenously into rats increased with the MW of the M-CSF used. Large increases in half-life in vivo were observed following chemical addition of a single molecule of 10 kD polyethylene glycol to rM-CSF in vitro. The crystal structure of rM-CSF revealed that M-CSF is a member of a family of molecules related by having a distinctive four-helical-bundle structural core. Site-directed mutagenesis showed that residues in or near helix A and helix C are involved in receptor binding, as reflected by decreased bioactivity and receptor binding of certain mutants. A soluble form of the M-CSF receptor, c-fms, was produced in a baculovirus/Sf9 expression system and purified to homogeneity. The MW of rM-CSF saturated with this soluble receptor was determined by molecular sieve chromatography and light scattering. Each dimeric M-CSF molecule appears to bind two soluble receptor molecules in vitro, supporting the observation that M-CSF signaling is linked to receptor dimerization.

Design of the therapeutic angiogenesis with recombinant fibroblast growth factor-2 for intermittent claudication (TRAFFIC) trial

Abstract: Therapeutic angiogenesis seeks to treat disorders of inadequate tissue perfusion by promoting the growth and proliferation of blood vessels from existing vascular structures. Basic fibroblast growth factor (also known as b-FGF or FGF-2) is a potent mitogen for endothelial cells. FGF-2 has been shown to promote angiogenesis and improve perfusion in animal models of hindlimb1,2 and myocardial 3,4 ischemia. ••• The Therapeutic Angiogenesis With Recombinant Fibroblast Growth Factor-2 for Intermittent Claudication (TRAFFIC) trial is a phase II, multicenter, randomized, double-blind, placebo-controlled regimen study of recombinant (r) FGF-2 or placebo in 180 subjects with moderate to severe intermittent claudication (IC) related to infrainguinal obstructive atherosclerosis. The protocol was approved by the institutional review board at each participating hospital. The major inclusion and exclusion criteria are listed in Tables 1 and 2, respectively. After written informed consent was obtained, patients underwent study-specific procedures including baseline exercise testing, hemodynamics, quality-of-life questionnaires, diagnostic angiography, and laboratory tests. Patients meeting all selection criteria were randomized to 1 of 3 groups (1:1:1). The placebo group received intraarterial placebo on days 1 and 30; the single group received rFGF-2 on day 1 and placebo on day 30; and the double group received rFGF-2 on days 1 and 30. The duration of follow-up was 180 days. The TRAFFIC study hypothesis was that intraarterial rFGF-2 increases exercise capacity in patients with moderate to severe IC due to infrainguinal peripheral artery disease (PAD). The primary end point was the change in exercise capacity as measured by the change in peak walking time from baseline to 90 days using the Gardner-graded treadmill exercise protocol. Secondary end points included change in peak walking time at 180 days, claudication onset time at 90 and 180 days, and change in ankle-brachial blood pressure index at 90 and 180 days. Changes in disease-specific and general quality of life were assessed by changes in the Walking Impairment Questionnaire and the Physical Component Summary Scale of the SF-36 Health Survey at 90 and 180 days. Acute hemodynamic changes, adverse events, renal function, antibody formation to FGF-2, and retinal examinations were followed for safety. Last, the pharmacoki