Josh Porterfield

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The recently established virus family Flaviviridae contains at least 68 recognized members. Sixty-six of these viruses were tested by cross-neutralization in cell cultures. Flaviviruses were separated into eight complexes [tick-borne encephalitis (12 viruses), Rio Bravo (six), Japanese encephalitis (10), Tyuleniy (three), Ntaya (five), Uganda S (four),(More)
Fusion between purified [3H]uridine-labelled West Nile virus (WNV) particles and liposomes containing RNase, was assayed by degradation of the viral RNA to trichloroacetic acid-soluble material. Fusion of virus with liposomes containing phosphatidylcholine, phosphatidylethanolamine, sphingomyelin and cholesterol (at a molar ratio of 1:1:1:1.5) was found to(More)
Interactions between animal viruses and antiviral antisera may exceptionally result in an apparent increase in viral infectivity. Halstead and coworkers demonstrated enhanced replication of dengue virus (a Flavivirus, family Togaviridae) in human or simian peripheral blood leucocytes carrying Fc receptors at subneutralising concentrations of antidengue(More)
Evidence is presented that M phi complement receptors (CR3) mediate IgM-dependent enhancement of flavivirus replication in the presence of complement. Enhancement is blocked by pretreatment of macrophages with monoclonal antibody Ml/70, which inhibits CR3 binding, but not by pretreatment with monoclonal antibody 2.4G2, which inhibits FcR binding.
Despite the considerable research that has been carried out into viral neutralization by antiviral antibody, its mechanisms remain poorly understood. Cases have been reported in which antiviral antibody can inhibit viral replication without inhibiting the binding and uptake of virus by susceptible cells. It has been shown that many enveloped viruses enter(More)
Flaviviruses, when complexed with antibody at subneutralizing concentrations, show enhanced replication in human and simian peripheral blood leukocytes (ref. 1, and J.S.M.P. and J.S.P., unpublished observations) and in P388 D1 and other macrophage cell lines. A comparable phenomenon has been demonstrated with alphaviruses and Bunyaviruses in P388 D1 cells,(More)
Bone-marrow aspirates from 5 patients with recent episodes of multiple sclerosis (M.S.) contained increased numbers of plasma cells, and aspirates from 3 of these patients contained atypical reticulum cells. When bone-marrow from 4 of the patients was inoculated into cell cultures a cytopathic effect (C.P.E.) was observed, and this effect could be serially(More)
The extracellular matrix (ECM) has been demonstrated to facilitate angiogenesis. In particular, fibronectin has been documented to activate endothelial cells, resulting in their transition from a quiescent state to an active state in which the cells exhibit enhanced migration and proliferation. The goal of this study is to examine the role of polymerized(More)
Hypoxia, a common feature of the tumor environment and participant in tumor progression, is known to alter gene and protein expression of several Extracellular Matrix (ECM) proteins, many of which have roles in angiogenesis. Previously, we reported that ECM deposited from co-cultures of Neonatal Fibroblasts (NuFF) with breast cancer cells, supported(More)
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