1,217 research outputs found
Recruitment of Immune Cells into Inflamed Tissues: Consequences for Endothelial Barrier Integrity and Tissue Functionality
Crossing the Vascular Wall: Common and Unique Mechanisms Exploited by Different Leukocyte Subsets during Extravasation
Leukocyte extravasation is one of the essential and first steps during the initiation of inflammation. Therefore, a better understanding of the key molecules that regulate this process may help to develop novel therapeutics for treatment of inflammation-based diseases such as atherosclerosis or rheumatoid arthritis. The endothelial adhesion molecules ICAM-1 and VCAM-1 are known as the central mediators of leukocyte adhesion to and transmigration across the endothelium. Engagement of these molecules by their leukocyte integrin receptors initiates the activation of several signaling pathways within both leukocytes and endothelium. Several of such events have been described to occur during transendothelial migration of all leukocyte subsets, whereas other mechanisms are known only for a single leukocyte subset. Here, we summarize current knowledge on regulatory mechanisms of leukocyte extravasation from a leukocyte and endothelial point of view, respectively. Specifically, we will focus on highlighting common and unique mechanisms that specific leukocyte subsets exploit to succeed in crossing endothelial monolayers
Secure, Mobile Visual Sensor Networks Architecture
As Wireless Sensor Network-based solutions are proliferating they are facing new challenges: they must be capable of adapting to rapidly changing environments and requirements while their nodes should have low power consumption as they usually run on batteries. Moreover, the security aspect is crucial since they frequently transmit and process very sensitive data, while it is important to be able to support real-time video or processed images over their limited bandwidth links. SMART targets to design and implement a highly reconfigurable Wireless Visual Sensor Node (WVSN) defined as a miniaturized, light-weight, secure, low-cost, battery powered sensing device, enriched with video and data compression capabilities
Diagnostic yield of electromagnetic navigation bronchoscopy is highly dependent on the presence of a Bronchus sign on CT imaging: results from a prospective study
Electromagnetic navigation bronchoscopy (ENB) has been developed as a
novel ancillary tool for the bronchoscopic diagnosis of pulmonary nodules.
Despite successful navigation in 90% of patients, ENB diagnostic yield does not
generally exceed 70%. We sought to determine whether the presence of a bronchus
sign on CT imaging conditions diagnostic yield of ENB and might account for the
discrepancy between successful navigation and diagnostic yield. METHODS: We
conducted a prospective, single-center study of ENB in 51 consecutive patients
with pulmonary nodules. ENB was chosen as the least invasive diagnostic technique
in patients with a high surgical risk, suspected metastatic disease, or
advanced-stage disease, or in those who demanded a preoperative diagnosis prior
to undergoing curative resection. We studied patient and technical variables that
might condition diagnostic yield, including size, cause, location, distance to
the pleural surface, and fluorodeoxyglucose uptake of a given nodule; the
presence of a bronchus sign on CT imaging; registration point divergence; and the
minimum distance from the tip of the locatable guide to the nodule measured
during the procedure. RESULTS: The diagnostic yield of ENB was 67% (34/51). The
sensitivity and specificity of ENB for malignancy in this study were 71% and
100%, respectively. ENB was diagnostic in 79% (30/38) patients with a bronchus
sign on CT imaging but only in 4/13 (31%) with no discernible bronchus sign.
Univariate analysis identified the bronchus sign (P = .005) and nodule size (P =
.04) as statistically significant variables conditioning yield, but on
multivariate analysis, only the bronchus sign remained significant (OR, 7.6; 95%
CI, 1.8-31.7). No procedure-related complications were observed. CONCLUSIONS: ENB
diagnostic yield is highly dependent on the presence of a bronchus sign on CT
imaging
Synovial two-phase sarcoma in third portion duodenal: clinical case and review of the literature
Early lung cancer detection using spiral computed tomography and positron emission tomography
RATIONALE:
Lung cancer screening using computed tomography (CT) is effective in detecting lung cancer in early stages. Concerns regarding false-positive rates and unnecessary invasive procedures have been raised.
OBJECTIVE:
To study the efficiency of a lung cancer protocol using spiral CT and F-18-fluorodeoxyglucose positron emission tomography (FDG-PET).
METHODS:
High-risk individuals underwent screening with annual spiral CTs. Follow-up CTs were done for noncalcified nodules of 5 mm or greater, and FDG-PET was done for nodules 10 mm or larger or smaller (> 7 mm), growing nodules.
RESULTS:
A total of 911 individuals completed a baseline CT study and 424 had at least one annual follow-up study. Of the former, 14% had noncalcified nodules of 5 mm or larger, and 3.6% had nodules of 10 mm or larger. Eleven non-small cell lung cancers (NSCLC) and one small cell lung cancer (SCLC) were diagnosed in the baseline study (prevalence rate, 1.32%), and two NSCLCs in the annual study (incidence rate, 0.47%). All NSCLCs (92% of prevalence cancers) were diagnosed in stage I (12 stage IA, 1 stage IB). FDG-PET was helpful for the correct diagnosis in 19 of 25 indeterminate nodules. The sensitivity, specificity, positive predictive value, and negative predictive value of FDG-PET for the diagnosis of malignancy were 69, 91, 90, and 71%, respectively. However, the sensitivity and negative predictive value of the screening algorithm, which included a 3-month follow-up CT for nodules with a negative FDG-PET, was 100%.
CONCLUSION:
A protocol for early lung cancer detection using spiral CT and FDG-PET is useful and may minimize unnecessary invasive procedures for benign lesions
High major histocompatibility complex class I polymorphism despite bottlenecks in wild and domesticated populations of the zebra finch ()
Background
Two subspecies of zebra finch, Taeniopygia guttata castanotis and T. g. guttata are native to Australia and the Lesser Sunda Islands, respectively. The Australian subspecies has been domesticated and is now an important model system for research. Both the Lesser Sundan subspecies and domesticated Australian zebra finches have undergone population bottlenecks in their history, and previous analyses using neutral markers have reported reduced neutral genetic diversity in these populations. Here we characterize patterns of variation in the third exon of the highly variable major histocompatibility complex (MHC) class I α chain. As a benchmark for neutral divergence, we also report the first mitochondrial NADH dehydrogenase 2 (ND2) sequences in this important model system.
Results
Despite natural and human-mediated population bottlenecks, we find that high MHC class I polymorphism persists across all populations. As expected, we find higher levels of nucleotide diversity in the MHC locus relative to neutral loci, and strong evidence of positive selection acting on important residues forming the peptide-binding region (PBR). Clear population differentiation of MHC allele frequencies is also evident, and this may be due to adaptation to new habitats and associated pathogens and/or genetic drift. Whereas the MHC Class I locus shows broad haplotype sharing across populations, ND2 is the first locus surveyed to date to show reciprocal monophyly of the two subspecies.
Conclusions
Despite genetic bottlenecks and genetic drift, all surveyed zebra finch populations have maintained high MHC Class I diversity. The diversity at the MHC Class I locus in the Lesser Sundan subspecies contrasts sharply with the lack of diversity in previously examined neutral loci, and may thus be a result of selection acting to maintain polymorphism. Given uncertainty in historical population demography, however, it is difficult to rule out neutral processes in maintaining the observed diversity. The surveyed populations also differ in MHC Class I allele frequencies, and future studies are needed to assess whether these changes result in functional immune differences
Halorhabdus tiamatea: Proteogenomics and glycosidase activity measurements identify the first cultivated euryarchaeon from a deep-sea anoxic brine lake as potential polysaccharide degrader.
Euryarchaea from the genus Halorhabdus have been found in hypersaline habitats worldwide, yet are represented by only two isolates: Halorhabdus utahensis AX-2T from the shallow Great Salt Lake of Utah, and Halorhabdus tiamatea SARL4BT from the Shaban deep-sea hypersaline anoxic lake (DHAL) in the Red Sea. We sequenced the H. tiamatea genome to elucidate its niche adaptations. Among sequenced archaea, H. tiamatea features the highest number of glycoside hydrolases, the majority of which were expressed in proteome experiments. Annotations and glycosidase activity measurements suggested an adaptation towards recalcitrant algal and plant-derived hemicelluloses. Glycosidase activities were higher at 2% than at 0% or 5% oxygen, supporting a preference for low-oxygen conditions. Likewise, proteomics indicated quinone-mediated electron transport at 2% oxygen, but a notable stress response at 5% oxygen. Halorhabdus tiamatea furthermore encodes proteins characteristic for thermophiles and light-dependent enzymes (e.g. bacteriorhodopsin), suggesting that H. tiamatea evolution was mostly not governed by a cold, dark, anoxic deep-sea habitat. Using enrichment and metagenomics, we could demonstrate presence of similar glycoside hydrolase-rich Halorhabdus members in the Mediterranean DHAL Medee, which supports that Halorhabdus species can occupy a distinct niche as polysaccharide degraders in hypersaline environments
CD47 plays a critical role in T-cell recruitment by regulation of LFA-1 and VLA-4 integrin adhesive functions
CD47 plays an important but incompletely understood role in the innate and adaptive immune responses. CD47, also called integrin-associated protein, has been demonstrated to associate in cis with β1 and β3 integrins. Here we test the hypothesis that CD47 regulates adhesive functions of T-cell α4β1 (VLA-4) and αLβ2 (LFA-1) in in vivo and in vitro models of inflammation. Intravital microscopy studies reveal that CD47(−/−) Th1 cells exhibit reduced interactions with wild-type (WT) inflamed cremaster muscle microvessels. Similarly, murine CD47(−/−) Th1 cells, as compared with WT, showed defects in adhesion and transmigration across tumor necrosis factor-α (TNF-α)–activated murine endothelium and in adhesion to immobilized intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion protein 1 (VCAM-1) under flow conditions. Human Jurkat T-cells lacking CD47 also showed reduced adhesion to TNF-α–activated endothelium and ICAM-1 and VCAM-1. In cis interactions between Jurkat T-cell β2 integrins and CD47 were detected by fluorescence lifetime imaging microscopy. Unexpectedly, Jurkat CD47 null cells exhibited a striking defect in β1 and β2 integrin activation in response to Mn(2+) or Mg(2+)/ethylene glycol tetraacetic acid treatment. Our results demonstrate that CD47 associates with β2 integrins and is necessary to induce high-affinity conformations of LFA-1 and VLA-4 that recognize their endothelial cell ligands and support leukocyte adhesion and transendothelial migration
Selected Schizosaccharomyces pombe Strains Have Characteristics That Are Beneficial for Winemaking
At present, wine is generally produced using Saccharomyces yeast followed by Oenococus bacteria to complete malolactic fermentation. This method has some unsolved problems, such as the management of highly acidic musts and the production of potentially toxic products including biogenic amines and ethyl carbamate. Here we explore the potential of the fission yeast Schizosaccharomyces pombe to solve these problems. We characterise an extensive worldwide collection of S. pombe strains according to classic biochemical parameters of oenological interest. We identify three genetically different S. pombe strains that appear suitable for winemaking. These strains compare favourably to standard Saccharomyces cerevisiae winemaking strains, in that they perform effective malic acid deacidification and significantly reduce levels of biogenic amines and ethyl carbamate precursors without the need for any secondary bacterial malolactic fermentation. These findings indicate that the use of certain S. pombe strains could be advantageous for winemaking in regions where malic acid is problematic, and these strains also show superior performance with respect to food safety
- …
