9 research outputs found

    Investigation of the Role of TNF-α Converting Enzyme (TACE) in the Inhibition of Cell Surface and Soluble TNF-α Production by Acute Ethanol Exposure

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    Toll-like receptors (TLRs) play a fundamental role in the immune system by detecting pathogen associated molecular patterns (PAMPs) to sense host infection. Ethanol at doses relevant for humans inhibits the pathogen induced cytokine response mediated through TLRs. The current study was designed to investigate the mechanisms of this effect by determining whether ethanol inhibits TLR3 and TLR4 mediated TNF-α secretion through inhibition of transcription factor activation or post-transcriptional effects. In NF-κB reporter mice, activation of NF-κB in vivo by LPS was inhibited by ethanol (LPS alone yielded 170,000±35,300 arbitrary units of light emission; LPS plus ethanol yielded 56,120±16880, p = 0.04). Inhibition of protein synthesis by cycloheximide revealed that poly I:C- or LPS-induced secreted TNF-α is synthesized de novo, not released from cellular stores. Using real time RT-PCR, we found inhibition of LPS and poly I:C induced TNF-α gene transcription by ethanol. Using an inhibitor of tumor necrosis factor alpha converting enzyme (TACE), we found that shedding caused by TACE is a prerequisite for TNF-α release after pathogen challenge. Flow cytometry was used to investigate if ethanol decreases TNF-α secretion by inhibition of TACE. In cells treated with LPS, ethanol decreased both TNF-α cell surface expression and secretion. For example, 4.69±0.60% of untreated cells were positive for cell surface TNF-α, LPS increased this to 25.18±0.85%, which was inhibited by ethanol (86.8 mM) to 14.29±0.39% and increased by a TACE inhibitor to 57.88±0.62%. In contrast, cells treated with poly I:C had decreased secretion of TNF-α but not cell surface expression. There was some evidence for inhibition of TACE by ethanol in the case of LPS, but decreased TNF-α gene expression seems to be the major mechanism of ethanol action in this system

    Structural changes in the cells of some bacteria during population growth: a fourier transform infrared-attenuated total reflectance study

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    Structural changes occurring in the cells of several bacteria during their growth curves have been investigated by Fourier transform infrared (FT-IR) spectroscopy using the sampling technique of attenuated total reflectance (ATR). Spectra reflect all of the components of the cells including the cell walls, cell membranes, internal structures and the cytoplasm. The bacteria studied were Bacillus stearothermophilus, Halobacterium salinarium, Halococcus morrhuae and Acetobacter aceti. All species showed significant spectral changes during their growth curves, indicating structural changes in the cells during increases in cell numbers. The major change for B. stearothermophilus was in the lipid content which was at a maximum during the exponential phase of the growth curve. For the halophiles H. salinarium and H. morrhuae the major change was that the concentration of sulfate ion in the cells varied during the growth curve and was at a maximum during the mid-part of the exponential phase of the growth curve. A. aceti cells showed increasing polysaccharide content during the growth curve as well as maximum lipid content during the exponential phase of growth

    A revision of the genus Europicardium

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    The cardiid genus Europicardium Popov, 1977 was introduced for a small group of Cenozoic species from Europe, but remained almost unknown in the western literature until about 15 years ago, and its type species, Cardium multicostatum Brocchi, 1814, continued to be cited mainly as Trachycardium multicostatum. Many records are available for this species from the Miocene of Europe, but most are based on several distinct, often misidentified species. In the present revision, based on museum material, the taxonomy of Europicardium is discussed and the identity of its type species is fixed. Seven species are assigned to Europicardium: E. multicostatum (Brocchi, 1814), E. miorotundatum (Sacco, 1899) (lectotype designated), E. miocaudatum (Sacco, 1899), E. polycolpatum (Cossmann & Peyrot, 1912), E. pseudomulticostatum (Zhizhchenko, 1934), E. badeniense (Kokay, 1996) and E. hoernesi sp. nov. from the middle Miocene of Austria. However, literature records and museum material suggest the occurrence of additional species and the need for further investigation. The oldest record of Europicardium is from the early Miocene of the Aquitaine Basin, from where the genus likely spread into the Mediterranean and throughout the Paratethys. Europicardium reached a maximum diversity in the early middle Miocene (Badenian) of the Paratethys, probably in relation to the Miocene Climatic Optimum, and also with the complex and variable palaeogeography of the Paratethys, which promoted differentiation and diversity. Europicardium disappeared from the Paratethys when it became a freshwater basin in the late Miocene, and from the Mediterranean due to the Messinian Salinity Crisis. The last European species was E. multicostatum, which arrived in the Mediterranean from the adjacent Atlantic with the post-Messinian recolonization, and became extinct in the Pleistocene due to climatic deterioration. At the present day, Europicardium occurs in the tropical waters of West Africa, with three specie

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    Taxonomy and biology of the argonauts (Cephalopoda: Argonautidae) with particular reference to Australian material

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