TBI risk stratification at presentation: a prospective study of the incidence and timing of radiographic worsening in the Parkland Protocol.

Background: We have created a theoretical algorithm for venous thromboembolism prophylaxis after traumatic brain injury (TBI) known as the Parkland Protocol, which stratifies patients into low-, medium-, and high-risk categories for spontaneous progression of hemorrhage. This prospective study characterizes the incidence and timing of radiographic progression of the TBI patterns in these categories.

Methods: Inclusion criterion was presentation with intracranial blood between February 2010 and March 2011; exclusion was receipt of only one computed tomographic scan of the head during the inpatient stay or preinjury warfarin.

A human T-cell lymphotropic virus type 1 enhancer of Myc transforming potential stabilizes Myc-TIP60 transcriptional interactions.

The human T-cell lymphotropic virus type 1 (HTLV-1) infects and transforms CD4+ lymphocytes and causes adult T-cell leukemia/lymphoma (ATLL), an aggressive lymphoproliferative disease that is often fatal. Here, we demonstrate that the HTLV-1 pX splice-variant p30II markedly enhances the transforming potential of Myc and transcriptionally activates the human cyclin D2 promoter, dependent upon its conserved Myc-responsive E-box enhancer elements, which are associated with increased S-phase entry and multinucleation. Enhancement of c-Myc transforming activity by HTLV-1 p30II is dependent upon the transcriptional coactivators, transforming transcriptional activator protein/p434 and TIP60, and it requires TIP60 histone acetyltransferase (HAT) activity and correlates with the stabilization of HTLV-1 p30II/Myc-TIP60 chromatin-remodeling complexes.

HIV-1 Tat interactions with p300 and PCAF transcriptional coactivators inhibit histone acetylation and neurotrophin signaling through CREB.

The human immunodeficiency virus type-1 (HIV-1) infects microglia, macrophages, and astrocytes in the central nervous system (CNS) and may cause severe neurological diseases, such as AIDS-related dementias or progressive encephalopathies, as a result of CNS inflammation and neurotrophin signaling defects associated with expression of viral antigens and HIV-1 replication in the brain. The HIV Tat protein can be endocytosed by surrounding uninfected cells; interacts with transcriptional coactivators/acetyltransferases, p300/CREB-binding protein, and p300/CREB-binding protein-associated factor (PCAF); and induces neuronal apoptosis. Since nerve growth factor (NGF) receptor and brain-derived neurotrophic factor receptor signaling through CREB requires p300 and PCAF histone acetyltransferases, we sought to determine whether HIV-1 Tat coactivator interactions interfere with neurotrophin receptor signaling in neuronal cells.

Nerve growth factor receptor signaling induces histone acetyltransferase domain-dependent nuclear translocation of p300/CREB-binding protein-associated factor and hGCN5 acetyltransferases.

The transcriptional coactivators, p300/CREB-binding protein-associated factor (PCAF) and hGCN5, are recruited to chromatin-remodeling complexes on enhancers of various gene promoters in response to growth factor stimulation. However, the molecular mechanisms by which surface receptor signals modulate the assembly of nuclear transcription complexes are not fully understood. Here we report that nerve growth factor receptor signaling induces nuclear translocation of PCAF and hGCN5 dependent upon the phosphorylation of Ser and Thr residues within their histone acetyltransferase domains, which requires activation of PI3K, Rsk2(pp90), and MSK-1.