Physician Assistant Student Perceptions of "Muddiest Point" Classroom Assessment Technique Implementation.

Purpose: To assess student perceptions of the use of the "Muddiest Point" as a type of formative classroom assessment technique (CAT) in a clinical skills laboratory course.

Methods: Physician assistant (PA) students enrolled in a private university were invited to complete a perception survey regarding the use of the Muddiest Point at the conclusion of the course.

Results: Survey results showed positive overall student perceptions of the Muddiest Point and desire for broader use of this CAT in other courses.

Efficacy and safety of tofacitinib for treatment of rheumatoid arthritis.

Tofacitinib is the first in a new class of nonbiologic disease-modifying antirheumatic drugs (DMARDs), a targeted, synthetic DMARD, approved for the treatment of rheumatoid arthritis (RA) as monotherapy or in combination with methotrexate or other non-biologic DMARD. Tofacitinib, an orally administered Janus kinase (JAK) inhibitor, decreases T-cell activation, pro-inflammatory cytokine production, and cytokine signaling by inhibiting binding of type I cytokine receptors family and γ-chain cytokines to paired JAK1/JAK3 receptors. The net effect of tofacitinb's mechanism of action is decreased synovial inflammation and structural joint damage in RA patients.

The SWI/SNF chromatin remodeling complex influences transcription by RNA polymerase I in Saccharomyces cerevisiae.

SWI/SNF is a chromatin remodeling complex that affects transcription initiation and elongation by RNA polymerase II. Here we report that SWI/SNF also plays a role in transcription by RNA polymerase I (Pol I) in Saccharomyces cerevisiae. Deletion of the genes encoding the Snf6p or Snf5p subunits of SWI/SNF was lethal in combination with mutations that impair Pol I transcription initiation and elongation.

The transcription elongation factor Spt5 influences transcription by RNA polymerase I positively and negatively.

Spt5p is a universally conserved transcription factor that plays multiple roles in eukaryotic transcription elongation. Spt5p forms a heterodimer with Spt4p and collaborates with other transcription factors to pause or promote RNA polymerase II transcription elongation. We have shown previously that Spt4p and Spt5p also influence synthesis of ribosomal RNA by RNA polymerase (Pol) I; however, previous studies only characterized defects in Pol I transcription induced by deletion of SPT4.

Distinguishing the roles of Topoisomerases I and II in relief of transcription-induced torsional stress in yeast rRNA genes.

To better understand the role of topoisomerase activity in relieving transcription-induced supercoiling, yeast genes encoding rRNA were visualized in cells deficient for either or both of the two major topoisomerases. In the absence of both topoisomerase I (Top1) and topoisomerase II (Top2) activity, processivity was severely impaired and polymerases were unable to transcribe through the 6.7-kb gene.

The Paf1 complex is required for efficient transcription elongation by RNA polymerase I.

Regulation of RNA polymerase I (Pol I) transcription is critical for controlling ribosome synthesis. Most previous investigations into Pol I transcription regulation have focused on transcription initiation. To date, the factors involved in the control of Pol I transcription elongation are poorly understood.

Electron microscope visualization of RNA transcription and processing in Saccharomyces cerevisiae by Miller chromatin spreading.

The Miller chromatin spreading technique for electron microscopic visualization of gently dispersed interphase chromatin has proven extremely valuable for analysis of genetic activities in vivo. It provides a unique view of transcription and RNA processing at the level of individual active genes. The budding yeast Saccharomyces cerevisiae has also been an invaluable model system for geneticists and molecular biologists.

Visual analysis of the yeast 5S rRNA gene transcriptome: regulation and role of La protein.

5S rRNA genes from Saccharomyces cerevisiae were examined by Miller chromatin spreading, representing the first quantitative analysis of RNA polymerase III genes in situ by electron microscopy. These very short genes, approximately 132 nucleotides (nt), were engaged by one to three RNA polymerases. Analysis in different growth conditions and in strains with a fourfold range in gene copy number revealed regulation at two levels: number of active genes and polymerase loading per gene.

Transcription elongation by RNA polymerase I is linked to efficient rRNA processing and ribosome assembly.

The synthesis of ribosomes in eukaryotic cells is a complex process involving many nonribosomal protein factors and snoRNAs. In general, the processes of rRNA transcription and ribosome assembly are treated as temporally or spatially distinct. Here, we describe the identification of a point mutation in the second largest subunit of RNA polymerase I near the active center of the enzyme that results in an elongation-defective enzyme in the yeast Saccharomyces cerevisiae.

EM visualization of Pol II genes in Drosophila: most genes terminate without prior 3' end cleavage of nascent transcripts.

Transcription termination by RNA polymerase II (Pol II) on most mRNA-encoding genes is dependent on transcription through a functional poly(A) signal. One model to explain this dependence predicts co-trancriptional cleavage of RNA at the poly(A) site. Electron microscopic (EM) visualization was used to investigate the in vivo frequency of transcript cleavage prior to termination.