Human parvovirus B19 infection of monocytic cell line U937 and antibody-dependent enhancement.

Human parvovirus B19 (B19) infects human erythroid lineage cells. Accumulating evidence also shows that B19 is detectable in nonerythroid lineage cells in vivo, but the mechanism of infection is still not clear. In this study, we explored the mode of B19 infection of human monocytic cell line U937.

Ku80 autoantigen as a cellular coreceptor for human parvovirus B19 infection.

Human parvovirus B19 (B19) infects human erythroid cells expressing P antigen. However, some cell lines that were positive for P antigen failed to bind B19, whereas some cell lines had an ability to bind B19 despite undetectable expression of P antigen. We here demonstrate that B19 specifically binds with Ku80 autoantigen on the cell surface.

Over-expression of Flt3 induces NF-kappaB pathway and increases the expression of IL-6.

Activating mutations or over-expression of the Flt3 is prevalent in acute myeloblastic leukemia (AML), associated with activation of Ras/MAP kinase and other signaling pathways. In this study, we addressed the role of Flt3 in the activation of nuclear factor-kappa B (NF-kappaB), which is a target molecule of these kinase pathways. In BaF3 cells stably expressing Flt3, a NF-kappaB-responsive reporter was upregulated and its target gene, IL-6, was increased by the involvement of Flt3-ERK/MAPK-NF-kappaB pathway.

Evaluation of a novel automated chemiluminescent assay system for antimicrobial susceptibility testing.

The newly developed Rapid Lumi Eiken/IS60 (RL/IS60) system automatically determines MICs by detecting chemiluminescence produced in the reaction of a chemiluminescent probe and oxygen metabolites from living microorganisms. The present study evaluated this system for accuracy in antimicrobial susceptibility testing. Chemiluminescence intensities after 4 h of cultivation of clinically important strains were plotted against various concentrations of antimicrobial agents, which resulted in curves reflecting the levels of susceptibility.

Abnormal white matter lesions with sensorineural hearing loss caused by congenital cytomegalovirus infection: retrospective diagnosis by PCR using Guthrie cards.

We report on two patients with congenital cytomegalovirus (CMV) infection asymptomatic at birth that was diagnosed retrospectively by polymerase chain reaction (PCR) of CMV DNA using blood stored on Guthrie cards. Neuroimaging studies showed abnormal myelination without any gray matter abnormalities. In the differential diagnosis of patients with abnormal white matter lesions and sensorineural hearing loss, one should consider congenital CMV infection.

Chemically modified ribozyme targeting TNF-alpha mRNA regulates TNF-alpha and IL-6 synthesis in synovial fibroblasts of patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) is chronic polyarthritis in which a variety of inflammatory cytokines play a role. Since tumor necrosis factor-alpha (TNF-alpha) is one of the most important cytokines in the pathogenesis of RA, we evaluated the feasibility of ribozymes as a therapeutic agent to control the inflammatory process of RA synovium. A hammerhead ribozyme against TNF-alpha was chemically modified to increase nuclease resistance and added to RA fibroblastlike cell cultures without using a delivery system.

Regulation of tumor necrosis factor alpha promoter by human parvovirus B19 NS1 through activation of AP-1 and AP-2.

Human parvovirus B19 frequently causes acute and chronic arthritis in adults. The molecular mechanism of B19 arthritis, however, remains poorly understood. We previously showed that the transmission of B19 from rheumatoid synoviocytes to monocytic cells is associated with enhanced secretion of tumor necrosis factor alpha (TNF-alpha), which triggers inflammation, and interleukin-6.