Learn More
The high affinity of antibodies produced during responses to T-cell-dependent antigens is associated with somatic mutation in the variable region of the immunoglobulin. Indirect evidence indicates that: (1) this arises by a process of hypermutation, acting selectively on rearranged immunoglobulin variable-region genes, which is activated in centroblasts(More)
JC virus (JCV) is a neurotropic polyomavirus infecting greater than 70% of the human population worldwide during early childhood. Replication of JCV in brains of individuals with impaired immune systems results in the fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). Furthermore, JCV possesses an oncogenic potential and induces(More)
For more than a century follicles have been recognized as a site of intense cell proliferation and cell death. At last the significance of this activity is beginning to emerge: antigen-driven B-cell proliferation, somatic mutation, positive and negative selection, and memory and plasma cell development all appear to take place within the follicle.
Hue and saturation scaling were used to measure the appearance of spectral lights as a function of stimulus size for nine loci across the horizontal retinal meridian. At a given locus, each hue (R, Y, G, and B) grew as a function of stimulus size up to some asymptotic value. The parameter values of Michaelis-Menten growth functions fitted to the hue data(More)
A set of psychophysical procedures is described for rapidly measuring visual functions such as spatial contrast sensitivity, flicker fusion, and rod and cone two-color increment thresholds in young children. The psychophysical procedures, disguised as electronic space games, use a forced-choice paradigm combined with the method of descending limits. Because(More)
MOTIVATION Identifying bacterial promoters is an important step towards understanding gene regulation. In this paper, we address the problem of predicting the location of promoters and their transcription start sites (TSSs) in Escherichia coli. The accepted method for this problem is to use position weight matrices (PWMs), which define conserved motifs at(More)
Epstein-Barr virus (EBV), a human herpesvirus, establishes a persistent asymptomatic infection of the circulating B-lymphocyte pool. The mechanism of virus persistence is not understood but, given the limited lifespan of most B cells in vivo, it seems most likely that EBV-infected cells must gain access to the long-lived memory B-cell pool. Here we show in(More)
We describe molecular and clinical findings in an immunocompetent patient with an oligoastrocytoma and the concomitant presence of the human papovavirus, JC virus (JCV), which is the etiologic agent of the subacute, debilitating demyelinating disease, progressive multifocal leukoencephalopathy. Histologic review revealed a glial neoplasm consisting(More)
Primary failure of host defense mechanisms has been associated with increased infection and mortality. Anergy, the failure of delayed hypersensitivity response, has been shown to identify surgical patients at increased risk for sepsis and related mortality. The anergic and relatively anergic patients whose skin tests failed to improve had a mortality rate(More)