Tnf(alpha)-dependent and Tnf(alpha)-independent Activation of Macrophage Effector Function

Tumor necrosis factor α (TNFα) is a pleiotropic cytokine that is predominantly produced by activated macrophages. The effects of TNFα are as diverse as the cells with which it interacts, e.g., stimulating fibroblast growth, exerting cytotoxic/cytostatic; activity against various human and murine cell lines, promoting inflammation through upregulation of endothelial adhesion molecules and IL-8 production. Yet TNFα is best known, and in fact was originally described, for its role in the bacterial-induced hemorrhagic necrosis of tumors and exacerbation of septic shock in which aberrant TNFα production leads to vascular collapse, cachexia, multiple organ failure, and ultimately death in as many as 100,000 people each year in the United States alone. LPS, a component of the outer cell wall of gram-negative bacteria, is the principal inducer of macrophage TNFα production. TNFα production can be enhanced by IFNγ which also induces upregulation of TNFα receptors allowing for the establishment of a TNFα autocrine loop. It has been hypothesized that autocrine TNFα stimulation plays a critical role in the induction of macrophage effector function, e.g., nitric oxide production. This dissertation represents efforts to evaluate the respective roles of the TNFα receptors in the induction of macrophage effector function, in addition to examining the mechanism by which autocrine TNFα exerts its effects on macrophages. Exploiting the species specificity of the murine TNFα receptor type 2 (TNF-R2), splenic macrophages were stimulated with human TNFα (which binds to TNF-R1 but not TNF-R2), in the presence of IFNγ. Human TNFα was effective in the induction of nitric oxide production, albeit at concentrations 12.5-fold greater than those required by murine TNFα to achieve the same result. Addition of anti-TNF-R1 completely inhibited the murine TNFα mediated induction of macrophage effector function. However, treatment with anti-TNF-R2 resulted in partial inhibition of macrophage activation. Taken together this data suggests that the primary TNFα mediated signals involved in macrophage activation are transduced through TNF-R1, although TNF-R2 appears to contribute to the intensity of the macrophage response. To evaluate the role of autocrine TNFα signaling in the induction of macrophage effector function, immortalized macrophages from normal C57Bl/6J mice (B6/J2) and C57Bl/6J mice containing gene targeted disruptions of the TNF-R1 and TNF-R2 genes (TRN) were stimulated under CD14-dependent and CD14-independent conditions. Although the B6/J2 and TRN clones mounted similar NO responses to LPS in the presence of serum, the TRN macrophages generated a weak nitric oxide response as compared to B6/J2 when stimulated with LPS under serum-free conditions. The involvement of TNFα autocrine stimulation in the CD14-independent activation was corroborated by the ability of soluble TNF-R1 to inhibit the response of B6/J2 macrophages to LPS in serum-free medium. CD14-independent LPS stimulation of TRN and B6/J2 resulted in equivalent levels of IL-1β, TNFα, and NOS gene expression, as determined by RT-PCR, and in release of equivalent amounts of biologically active TNFα. However, western blot analysis revealed that NOS protein production by TRN was as much as 50% less than that produced by B6/J2. These results indicate that autocrine TNFα stimulation contributes to the signaling pathways initiated by ligation of CD14-independent LPS receptors and may be involved in NOS post-transcriptional regulation

Screening of cryptic species among clinical Aspergillus isolates collected during one year period in a Portuguese reference laboratory

Objectives: Correct identification of Aspergillus species is important given that sibling species may show variable susceptibilities to multiple antifungal drugs and also because sharper definition of species may facilitate epidemiological studies. Thus, we screened Aspergillus clinical isolates from Portuguese hospitals to determine which, if any, of the cryptic species of Aspergillus were involved in patient infections. Methods: Over a one year period, Aspergillus isolates from Portuguese health institutions were collected. These isolates were identified on the basis of microscopic morphology and through the use of molecular tools. Genomic DNA was prepared from each isolate and the sequencing of the Internal Transcribed Spacers (ITS) regions, specifically the ITS1 and ITS2 non-coding regions flanking the 5.8S rDNA was used to determine the species complex, whereas β-tubulin and calmodulin sequencing was done to achieve the correct species identification. Results: Over the study period, 57 Aspergillus isolates from clinical samples were collected from 10 Portuguese health institutions. According to the morphological observations, 29 isolates were identified as Aspergillus fumigatus, 11 A. flavus, 8 A. niger, 3 A. nidulans, 2 A. terreus, 2 A. candidus and 2 Aspergillus sp. Among those isolates, six species-complexes were detected by ITS sequencing, and were distributed as follows: fumigati (50.1%), flavi (21.0%), nigri (15.8%), terrei (5.3%), nidulantes (3.6%) and versicolores (3.6%). β-tubulin and calmodulin sequencing resulted in ten (17.5%) cryptic species being identified among the 57 isolates. Six of those isolates belonged to the nigri complex (A. brasiliensis, A. awamorii and A. tubigensis), two to the versicolores complex (A. sidowii and A. fructus), one to the fumigati complex (A. lentulus) and one to the nidulantes complex (Emmericella echinulata). Conclusion: With rigorous application of molecular tools, cryptic species of Aspergillus are not uncommon in the clinic. The identification of cryptic species among the collected clinical isolates of Aspergillus alerts the clinician to isolates with reduced susceptibilities to antifungal drugs and emphasizes a correct identification to species level

Acoustic performance of a 50.8-cm (20-inch) diameter variable-pitch fan and inlet. Volume 2: Acoustic data

Results from acoustic tests on a 50.8 cm (20 inch) QCSEE Under-the-Wing (UTW) engine, variable pitch fan and inlet simulator are tabulated. Tests were run in both forward and reverse thrust mdoes with a bellmouth inlet, five accelerating inlets (one hardwall and four treated), and four low Mach number inlets (one hardwall and three treated). The 1/3 octave-band acoustic data are presented for the model size on the measured 5.2 m (17.0 ft) arc and also data scaled to full QCSEE size 71:20 on a 152.4 m (500 ft) sideline

A large conformational change of the translocation ATPase SecA

The ATPase SecA mediates the posttranslational translocation of a wide range of polypeptide substrates through the SecY channel in the cytoplasmic membrane of bacteria. We have determined the crystal structure of a monomeric form of Bacillus subtilis SecA at a 2.2-Å resolution. A comparison with the previously determined structures of SecA reveals a nucleotide-independent, large conformational change that opens a deep groove similar to that in other proteins that interact with diverse polypeptides. We propose that the open form of SecA represents an activated state

PLA/WOOD BIOCOMPOSITES: IMPROVING COMPOSITE STRENGTH BY CHEMICAL TREATMENT OF THE FIBERS

A resol type phenolic resin was prepared for the impregnation of wood particles used for the reinforcement of PLA. A preliminary study showed that the resin penetrates wood with rates depending on the concentration of the solution and on temperature. Treatment with a solution of 1 wt% resin resulted in a considerable increase of composite strength and decrease of water absorption. Composite strength improved as a result of increased inherent strength of the wood, but interfacial adhesion might be modified as well. When wood was treated with resin solutions of larger concentrations, the strength of the composites decreased, first slightly, then drastically to a very small value. A larger amount of resin results in a thick coating on wood with inferior mechanical properties. At large resin contents the mechanism of deformation changes; the thick coating breaks very easily leading to the catastrophic failure of the composites at very small loads

ICIS 2008 Panel Report: Design Science in Information Systems: Hegemony, Bandwagon, or New Wave?

In the past few years, design science has become a topic of increasing importance, especially in the North American academic IS community. Some observers see a new hegemony forming. Others dispute that but suggest that design science is merely the latest bandwagon rolling through the IS domain. A panel at the 2008 International Conference on Information Systems debated views of design science prevalent in the IS community. This paper reports on the panel discussion and attempts to position design science from various perspectives, including North American and European views, the latter with a long tradition of design-based IS scholarship

ICIS 2008 Panel Report: Design Science in Information Systems: Hegemony, Bandwagon, or New Wave?

In the past few years, design science has become a topic of increasing importance, especially in the North American academic IS community. Some observers see a new hegemony forming. Others dispute that but suggest that design science is merely the latest bandwagon rolling through the IS domain. A panel at the 2008 International Conference on Information Systems debated views of design science prevalent in the IS community. This paper reports on the panel discussion and attempts to position design science from various perspectives, including North American and European views, the latter with a long tradition of design-based IS scholarship

Macular telangiectasia type 2 - Visual acuity, disease endstage and the MacTel Area. MacTel Project Report No. 8

Purpose: To report the visual acuity measures from the MacTel registry study and to investigate and describe phenotypic findings in eyes with substantial vision loss due to MacTel type 2 Design: Cross-sectional multi-center study. Subjects: Participants of the Natural History Observation (and Registry) of MacTel Study. Methods: Best–corrected visual acuity (BCVA) data, retinal imaging data and clinical data were accessed from the MacTel study databases in May 2019. Main Outcome Measures: Frequency distribution of BCVA and its relation to age. Morphological changes in eyes with very late disease stages, defined by a BCVA ≤ 20/200. Average retinal thickness of ETDRS fields on OCT. Dimensions of the area affected by MacTel (MacTel area). Results: BCVA was ≤20/50 in 37.3% and ≤20/200 in 3.8% of 4449 eyes of 2248 patients. 18.4% and 0.7% of all patients had bilateral BCVA ≤20/50 and ≤20/200, respectively. There was an asymmetry between right and left eyes (median BCVA 71 versus 74 letters), a finding supported by more advanced morphological changes in right eyes. BCVA correlated with participant’s age, but the effect size was small. If a neovascularization or macular hole was present, bilateral occurrence was frequent (33% or 17%, respectively), and BCVA was >20/200 (79% or 78% respectively) or ≥20/50 (26% or 13%, respectively). Eyes with advanced disease (BCVA ≤20/200) showed the following characteristics: 1) Atrophy of the foveal photoreceptor layer with or without associated subretinal fibrosis; 2) an affected area, termed here the “MacTel area”, limited to a horizontal diameter not exceeding the distance between the temporal optic disc margin and foveal center, and the vertical diameter not exceeding approximately 0.85 times this distance. Exceptions were eyes with large active or inactive neovascular membranes; 3) reduced retinal thickness measures within the MacTel area; and 4) less frequent retinal greying and more frequent hyperpigmentations compared to eyes with better BCVA. Conclusions: Severe vision loss is rare in MacTel and is related to photoreceptor atrophy in most people. Results indicate disease asymmetry with slightly worse vision and more advanced disease manifestation in right eyes. MacTel-related neurodegeneration does not spread beyond the limits of the “MacTel area”