State University of New York System

About: State University of New York System is a education organization based out in Albany, New York, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 54077 authors who have published 78070 publications receiving 2985160 citations.

New strains of bacteria and exacerbations of chronic obstructive pulmonary disease.

Abstract: Background The role of bacterial pathogens in acute exacerbations of chronic obstructive pulmonary disease is controversial. In older studies, the rates of isolation of bacterial pathogens from sputum were the same during acute exacerbations and during stable disease. However, these studies did not differentiate among strains within a bacterial species and therefore could not detect changes in strains over time. We hypothesized that the acquisition of a new strain of a pathogenic bacterial species is associated with exacerbation of chronic obstructive pulmonary disease. Methods We conducted a prospective study in which clinical information and sputum samples for culture were collected monthly and during exacerbations from 81 outpatients with chronic obstructive pulmonary disease. Molecular typing of sputum isolates of nonencapsulated Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Pseudomonas aeruginosa was performed. Results Over a period of 56 months, the 81 patients made a ...

Internal ribosome entry sites in eukaryotic mRNA molecules

Abstract: Initiation of translation of most eukaryotic mRNAs commences with 5 end–dependent recruitment of 40S ribosomal subunits to the mRNA. The 40S subunit carrying the initiator methionine-tRNA and certain eukaryotic initiation factors (eIFs) is thought to scan the mRNA in a 5 to 3 direction until an appropriate start codon is encountered at which stage a 60S subunit joins to form an 80S ribosome that can decode the RNA into protein (Kozak 1989; Hershey and Merrick 2000). A subset of mRNAs contains internal ribosomal entry sites (IRESs), usually in the 5 NTR, that enable end-independent initiation to occur. IRES-containing mRNAs are not subjected to many of the regulatory mechanisms that control recruitment of most mRNAs to the translation apparatus. In this review, we briefly provide an introduction to the known mechanisms of translation initiation. Then, we discuss in detail the molecular mechanisms of IRES-mediated initiation and how they are used by specific mRNAs to permit translation under physiological circumstances such as mitosis, apoptosis, hypoxia, and some viral infections when translation of most mRNAs is repressed.

The molecular interstellar medium in ultraluminous infrared galaxies

Abstract: We present observations with the IRAM 30 m telescope of CO in a large sample of ultraluminous IR galaxies out to redshift z = 0.3. Most of the ultraluminous galaxies in this sample are interacting, but not completed, mergers. The CO(1-0) luminosity of all but one of the ultraluminous galaxies is high, with values of log (L${′}{r CO}$ -->/K km s-1 pc2) = 9.92 ? 0.12. The extremely small dispersion of only 30% is less than that of the far-infrared luminosity. The integrated CO line intensity is strongly correlated with the 100 ?m flux density, as expected for a blackbody model in which the mid- and far-IR radiation is optically thick. We use this model to derive sizes of the FIR- and CO-emitting regions and the enclosed dynamical masses. Both the IR and CO emission originate in regions a few hundred parsecs in radius. The median value of LFIR${r FIR}$ -->/L${′}{r CO}$ -->=160 L?/K km s-1 pc2, within a factor of 2 or 3 of the blackbody limit for the observed far-IR temperatures. The entire ISM is a scaled-up version of a normal galactic disk with the ambient densities a factor of 100 higher, making even the intercloud medium a molecular region. We compare three different techniques of H2 mass estimation and conclude that the ratio of gas mass to CO luminosity is about a factor of 4 times lower than for giant molecular clouds (GMCs) but that the gas mass is a large fraction of the dynamical mass. Our analysis of CO emission from ultraluminous galaxies reduces the H2 mass from previous estimates of 2-5 ? 1010 M? to 0.4-1.5 ? 1010 M?, which is in the range found for molecular gas-rich spiral galaxies. A collision involving a molecular gas-rich spiral could lead to an ultraluminous galaxy powered by central starbursts triggered by the compression of infalling preexisting GMCs. The extremely dense molecular gas in the center of an ultraluminous galaxy is an ideal stellar nursery for a huge starburst.