139 research outputs found
An imaging spectroscopic survey of the planetary nebula NGC 7009 with MUSE
Aims. The spatial structure of the emission lines and continuum over the 5000 extent of the nearby, O-rich, PN NGC 7009 (Saturn
Nebula) have been observed with the MUSE integral field spectrograph on the ESO Very Large Telescope. This study concentrates on
maps of line emission and their interpretation in terms of physical conditions.
Methods. MUSE Science Verification data, in <0.600 seeing, have been reduced and analysed as maps of emission lines and continuum
over the wavelength range 4750–9350 Å. The dust extinction, the electron densities and temperatures of various phases of the ionized
gas, abundances of species from low to high ionization and some total abundances are determined using standard techniques.
Results. Emission line maps over the bright shells are presented, from neutral to the highest ionization available (He II and [Mn V]).
For collisionally excited lines (CELs), maps of electron temperature (Te from [N II] and [S III]) and density (Ne from [S II] and [Cl III])
are available and for optical recombination lines (ORLs) temperature (from the Paschen jump and ratio of He I lines) and density (from
high Paschen lines). These estimates are compared: for the first time, maps of the differences in CEL and ORL Te’s have been derived,
and correspondingly a map of t
2 between a CEL and ORL temperature, showing considerable detail. Total abundances of only He and
O were formed, the latter using three ionization correction factors. However, the map of He/H is not flat, departing by ∼2% from a
constant value, with remnants corresponding to ionization structures. An integrated spectrum over an area of 2340 arcsec2 was also
formed and compared to 1D photoionization models.
Conclusions. The spatial variation of a range of nebular parameters illustrates the complexity of the ionized media in NGC 7009.
These MUSE data are very rich with detections of hundreds of lines over areas of hundreds of arcsec2
and follow-on studies are
outlined
Systematic review and meta-analysis of the diagnostic accuracy of ultrasonography for deep vein thrombosis
Background
Ultrasound (US) has largely replaced contrast venography as the definitive diagnostic test for deep vein thrombosis (DVT). We aimed to derive a definitive estimate of the diagnostic accuracy of US for clinically suspected DVT and identify study-level factors that might predict accuracy.
Methods
We undertook a systematic review, meta-analysis and meta-regression of diagnostic cohort studies that compared US to contrast venography in patients with suspected DVT. We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, and citation lists (1966 to April 2004). Random effects meta-analysis was used to derive pooled estimates of sensitivity and specificity. Random effects meta-regression was used to identify study-level covariates that predicted diagnostic performance.
Results
We identified 100 cohorts comparing US to venography in patients with suspected DVT. Overall sensitivity for proximal DVT (95% confidence interval) was 94.2% (93.2 to 95.0), for distal DVT was 63.5% (59.8 to 67.0), and specificity was 93.8% (93.1 to 94.4). Duplex US had pooled sensitivity of 96.5% (95.1 to 97.6) for proximal DVT, 71.2% (64.6 to 77.2) for distal DVT and specificity of 94.0% (92.8 to 95.1). Triplex US had pooled sensitivity of 96.4% (94.4 to 97.1%) for proximal DVT, 75.2% (67.7 to 81.6) for distal DVT and specificity of 94.3% (92.5 to 95.8). Compression US alone had pooled sensitivity of 93.8 % (92.0 to 95.3%) for proximal DVT, 56.8% (49.0 to 66.4) for distal DVT and specificity of 97.8% (97.0 to 98.4). Sensitivity was higher in more recently published studies and in cohorts with higher prevalence of DVT and more proximal DVT, and was lower in cohorts that reported interpretation by a radiologist. Specificity was higher in cohorts that excluded patients with previous DVT. No studies were identified that compared repeat US to venography in all patients. Repeat US appears to have a positive yield of 1.3%, with 89% of these being confirmed by venography.
Conclusion
Combined colour-doppler US techniques have optimal sensitivity, while compression US has optimal specificity for DVT. However, all estimates are subject to substantial unexplained heterogeneity. The role of repeat scanning is very uncertain and based upon limited data
An Arthropod Enzyme, Dfurin 1, and a Vertebrate Furin Homolog Display Distinct Cleavage Site Sequence Preferences for a Shared Viral Proprotein Substrate
Alphaviruses replicate in vertebrate and arthropod cells and utilize a cellular enzyme called furin to process the PE2 glycoprotein precursor during virus replication in both cell types. Furin cleaves PE2 at a site immediately following a highly conserved four residue cleavage signal. Prior studies demonstrated that the amino acid immediately adjacent to the cleavage site influenced PE2 cleavage differently in vertebrate and mosquito cells (HW Heidner et al. 1996. Journal of Virology 70: 2069–2073.). This finding was tentatively attributed to potential differences in the substrate specificities of the vertebrate and arthropod furin enzymes or to differences in the carbohydrate processing phenotypes of arthropod and vertebrate cells. To further address this issue, we evaluated Sindbis virus replication and PE2 cleavage in the Chinese hamster, Cricetulus griseus Milne-Edwards (Rodentia: Cricetidae) ovary cells (CHO-K1) and in a CHO-K1-derived furin-negative cell line (RPE.40) engineered to stably express the Dfurin1 enzyme of Drosophila melanogaster Meigen (Diptera: Drosophilidae). Expression of Dfurin1 enhanced Sindbis virus titers in RPE.40 cells by a factor of 102 – 103, and this increase correlated with efficient cleavage of PE2. The PE2-cleavage phenotypes of viruses containing different amino acid substitutions adjacent to the furin cleavage site were compared in mosquito (C6/36), CHO-K1, and Dfurin1-expressing RPE.40 cells. This analysis confirmed that the substrate specificities of Dfurin1 and the putative mosquito furin homolog present in C6/36 cells are similar and suggested that the alternative PE2 cleavage phenotypes observed in vertebrate and arthropod cells were due to differences in substrate specificity between the arthropod and vertebrate furin enzymes and not to differences in host cell glycoprotein processing pathways
Family history of the cancer on the survival of the patients with gastrointestinal cancer in northern Iran, using frailty models
Salmonella Biofilm Formation on Aspergillus niger Involves Cellulose – Chitin Interactions
Salmonella cycles between host and nonhost environments, where it can become an active member of complex microbial communities. The role of fungi in the environmental adaptation of enteric pathogens remains relatively unexplored. We have discovered that S. enterica Typhimurium rapidly attaches to and forms biofilms on the hyphae of the common fungus, Aspergillus niger. Several Salmonella enterica serovars displayed a similar interaction, whereas other bacterial species were unable to bind to the fungus. Bacterial attachment to chitin, a major constituent of fungal cell walls, mirrored this specificity. Pre-incubation of S. Typhimurium with N-acetylglucosamine, the monomeric component of chitin, reduced binding to chitin beads by as much as 727-fold and inhibited attachment to A. niger hyphae considerably. A cellulose-deficient mutant of S. Typhimurium failed to attach to chitin beads and to the fungus. Complementation of this mutant with the cellulose operon restored binding to chitin beads to 79% of that of the parental strain and allowed for attachment and biofilm formation on A. niger, indicating that cellulose is involved in bacterial attachment to the fungus via the chitin component of its cell wall. In contrast to cellulose, S. Typhimurium curli fimbriae were not required for attachment and biofilm development on the hyphae but were critical for its stability. Our results suggest that cellulose–chitin interactions are required for the production of mixed Salmonella-A. niger biofilms, and support the hypothesis that encounters with chitinaceous alternate hosts may contribute to the ecological success of human pathogens
A genome-wide association scan implicates <i>DCHS2, RUNX2, GLI3, PAX1</i> and <i>EDAR</i> in human facial variation
We report a genome-wide association scan for facial features in ∼6,000 Latin Americans. We evaluated 14 traits on an ordinal scale and found significant association (P values−8) at single-nucleotide polymorphisms (SNPs) in four genomic regions for three nose-related traits: columella inclination (4q31), nose bridge breadth (6p21) and nose wing breadth (7p13 and 20p11). In a subsample of ∼3,000 individuals we obtained quantitative traits related to 9 of the ordinal phenotypes and, also, a measure of nasion position. Quantitative analyses confirmed the ordinal-based associations, identified SNPs in 2q12 associated to chin protrusion, and replicated the reported association of nasion position with SNPs in PAX3. Strongest association in 2q12, 4q31, 6p21 and 7p13 was observed for SNPs in the EDAR, DCHS2, RUNX2 and GLI3 genes, respectively. Associated SNPs in 20p11 extend to PAX1. Consistent with the effect of EDAR on chin protrusion, we documented alterations of mandible length in mice with modified Edar function
Brucellosis Vaccines: Assessment of Brucella melitensis Lipopolysaccharide Rough Mutants Defective in Core and O-Polysaccharide Synthesis and Export
Background: The brucellae are facultative intracellular bacteria that cause brucellosis, one of the major neglected zoonoses. In endemic areas, vaccination is the only effective way to control this disease. Brucella melitensis Rev 1 is a vaccine effective against the brucellosis of sheep and goat caused by B. melitensis, the commonest source of human infection. However, Rev 1 carries a smooth lipopolysaccharide with an O-polysaccharide that elicits antibodies interfering in serodiagnosis, a major problem in eradication campaigns. Because of this, rough Brucella mutants lacking the O-polysaccharide have been proposed as vaccines. Methodology/Principal Findings: To examine the possibilities of rough vaccines, we screened B. melitensis for lipopolysaccharide genes and obtained mutants representing all main rough phenotypes with regard to core oligosaccharide and O-polysaccharide synthesis and export. Using the mouse model, mutants were classified into four attenuation patterns according to their multiplication and persistence in spleens at different doses. In macrophages, mutants belonging to three of these attenuation patterns reached the Brucella characteristic intracellular niche and multiplied intracellularly, suggesting that they could be suitable vaccine candidates. Virulence patterns, intracellular behavior and lipopolysaccharide defects roughly correlated with the degree of protection afforded by the mutants upon intraperitoneal vaccination of mice. However, when vaccination was applied by the subcutaneous route, only two mutants matched the protection obtained with Rev 1 albeit at doses one thousand fold higher than this reference vaccine. These mutants, which were blocked in O-polysaccharide export and accumulated internal O-polysaccharides, stimulated weak anti-smooth lipopolysaccharide antibodies. Conclusions/Significance: The results demonstrate that no rough mutant is equal to Rev 1 in laboratory models and question the notion that rough vaccines are suitable for the control of brucellosis in endemic areas.This work was funded by the European Commission (Research Contract QLK2-CT-2002-00918) and the Ministerio de Ciencia y Tecnología of Spain
(Proyecto AGL2004-01162/GAN)
Rate and duration of hospitalisation for acute pulmonary embolism in the real-world clinical practice of different countries : Analysis from the RIETE registry
publishersversionPeer reviewe
A cross-sectional investigation of regional patterns of diet and cardio-metabolic risk in India
<p>Abstract</p> <p>Background</p> <p>The role of diet in India's rapidly progressing chronic disease epidemic is unclear; moreover, diet may vary considerably across North-South regions.</p> <p>Methods</p> <p>The India Health Study was a multicenter study of men and women aged 35-69, who provided diet, lifestyle, and medical histories, as well as blood pressure, fasting blood, urine, and anthropometric measurements. In each region (Delhi, n = 824; Mumbai, n = 743; Trivandrum, n = 2,247), we identified two dietary patterns with factor analysis. In multiple logistic regression models adjusted for age, gender, education, income, marital status, religion, physical activity, tobacco, alcohol, and total energy intake, we investigated associations between regional dietary patterns and abdominal adiposity, hypertension, diabetes, and dyslipidemia.</p> <p>Results</p> <p>Across the regions, more than 80% of the participants met the criteria for abdominal adiposity and 10 to 28% of participants were considered diabetic. In Delhi, the "fruit and dairy" dietary pattern was positively associated with abdominal adiposity [highest versus lowest tertile, multivariate-adjusted OR and 95% CI: 2.32 (1.03-5.23); P<sub>trend </sub>= 0.008] and hypertension [2.20 (1.47-3.31); P<sub>trend </sub>< 0.0001]. In Trivandrum, the "pulses and rice" pattern was inversely related to diabetes [0.70 (0.51-0.95); P<sub>trend </sub>= 0.03] and the "snacks and sweets" pattern was positively associated with abdominal adiposity [2.05 (1.34-3.14); P<sub>trend </sub>= 0.03]. In Mumbai, the "fruit and vegetable" pattern was inversely associated with hypertension [0.63 (0.40-0.99); P<sub>trend </sub>= 0.05] and the "snack and meat" pattern appeared to be positively associated with abdominal adiposity.</p> <p>Conclusions</p> <p>Cardio-metabolic risk factors were highly prevalent in this population. Across all regions, we found little evidence of a Westernized diet; however, dietary patterns characterized by animal products, fried snacks, or sweets appeared to be positively associated with abdominal adiposity. Conversely, more traditional diets in the Southern regions were inversely related to diabetes and hypertension. Continued investigation of diet, as well as other environmental and biological factors, will be needed to better understand the risk profile in this population and potential means of prevention.</p
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