Acquired aplastic anemia (AA) is a life-threatening bone marrow aplasia caused by the autoimmune destruction of hematopoietic stem and progenitor cells. There are no existing diagnostic tests that definitively establish AA, and diagnosis is currently made via systematic exclusion of various alternative etiologies, including inherited bone marrow failure syndromes (IBMFSs). The exclusion of IBMFSs, which requires syndrome-specific functional and genetic testing, can substantially delay treatment.
View Article and Find Full Text PDFOsteoclast-rich undifferentiated carcinoma of the urinary tract (ORUCUT) is a rare tumor composed of ovoid to spindle-shaped mononuclear cells with intermixed or focally clustered osteoclast-like giant cells. Previous studies have demonstrated that the mononuclear cells are neoplastic cells, while the giant cells are reactive cells of histiocytic lineage. The association between these tumors and classic urothelial carcinomas suggest that the mononuclear cells are derived from urothelial cells; however, no studies have been conducted to assess the immunohistochemical profile of ORUCUT with more specific urothelial markers.
View Article and Find Full Text PDFInfluenza A is a negative-sense RNA virus with an eight-segment genome. Some segments encode more than one polypeptide product, but how the virus accesses alternate internal open reading frames (ORFs) is not completely understood. In segment 2, ribosomal scanning produces two internal ORFs, PB1-F2 and N40.
View Article and Find Full Text PDFInfluenza A virus is a segmented single-stranded (-)RNA virus that causes substantial annual morbidity and mortality. The transcriptome of influenza A is predicted to have extensive RNA secondary structure. The smallest genome segment, segment 8, encodes two proteins, NS1 and NEP, via alternative splicing.
View Article and Find Full Text PDFBackground: Influenza A virus contributes to seasonal epidemics and pandemics and contains Global Ordered RNA structure (GORS) in the nucleoprotein (NP), non-structural (NS), PB2, and M segments. A related virus, influenza B, is also a major annual public health threat, but unlike influenza A is very selective to human hosts. This study extends the search for GORS to influenza B.
View Article and Find Full Text PDFThe 3' splice site of the influenza A segment 7 transcript is utilized to produce mRNA for the critical M2 ion-channel protein. In solution a 63 nt fragment that includes this region can adopt two conformations: a pseudoknot and a hairpin. In each conformation, the splice site, a binding site for the SF2/ASF exonic splicing enhancer and a polypyrimidine tract, each exists in a different structural context.
View Article and Find Full Text PDFThe 3' splice site of influenza A segment 7 is used to produce mRNA for the M2 ion-channel protein, which is critical to the formation of viable influenza virions. Native gel analysis, enzymatic/chemical structure probing, and oligonucleotide binding studies of a 63 nt fragment, containing the 3' splice site, key residues of an SF2/ASF splicing factor binding site, and a polypyrimidine tract, provide evidence for an equilibrium between pseudoknot and hairpin structures. This equilibrium is sensitive to multivalent cations, and can be forced towards the pseudoknot by addition of 5 mM cobalt hexammine.
View Article and Find Full Text PDFInfluenza A is a significant public health threat, partially because of its capacity to readily exchange gene segments between different host species to form novel pandemic strains. An understanding of the fundamental factors providing species barriers between different influenza hosts would facilitate identification of strains capable of leading to pandemic outbreaks and could also inform vaccine development. Here, we describe the difference in predicted RNA secondary structure stability that exists between avian, swine and human coding regions.
View Article and Find Full Text PDFInfluenza A is a negative sense RNA virus of significant public health concern. While much is understood about the life cycle of the virus, knowledge of RNA secondary structure in influenza A virus is sparse. Predictions of RNA secondary structure can focus experimental efforts.
View Article and Find Full Text PDFBiochem Mol Biol Educ
March 2005
One of the challenges in teaching biochemistry is facilitating students' interest in and mastery of metabolism. The many pathways and modes of regulation can be overwhelming for students to learn and difficult for professors to teach in an engaging manner. We have found it useful to take advantage of prevailing interest in popular yet controversial weight-loss methods, particularly low-carbohydrate diets.
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