708 research outputs found
Transcriptomic Complexity of Aspergillus terreus Velvet Gene Family under the Influence of Butyrolactone I
Filamentous fungi of the Ascomycota phylum are known to contain a family of conserved conidiation regulating proteins with distinctive velvet domains. In Aspergilli, this velvet family includes four proteins, VeA, VelB, VelC and VosA, and is involved in conidiation and secondary metabolism along with a global regulator LaeA. In A. terreus, the overexpression of LaeA has been observed to increase the biogenesis of the harmaceutically-important secondary metabolite, lovastatin, while the role of the velvet family has not been studied. The secondary metabolism and conidiation of A. terreus have also been observed to be increased by butyrolactone I in a quorum-sensing manner. An enlightenment of the interplay of these regulators will give potential advancement to the industrial use of this fungus, as well as in resolving the pathogenic features.
In this study, the Aspergillus terreus MUCL 38669 transcriptome was strand-specifically sequenced to enable an in-depth gene expression analysis to further investigate the transcriptional role of butyrolactone I in these processes. The sequenced transcriptome revealed intriguing properties of the velvet family transcripts, including the regulator laeA, and uncovered the velC gene in A. terreus. The reliability refining microarray gene expression analysis disclosed a positive regulatory role
for butyrolactone I in laeA expression, as well as an influence on the expression of the canonical conidiation-regulating genes under submerged culture. All of this supports the suggested regulative role of butyrolactone I in A. terreus secondary metabolism, as well as conidiation
Thermal and porosity properties of meteorites : A compilation of published data and new measurements
We report direct measurements of thermal diffusivity and conductivity at room temperature for 38 meteorite samples of 36 different meteorites including mostly chondrites, and thus almost triple the number of meteorites for which thermal conductivity is directly measured. Additionally, we measured porosity for 34 of these samples. Thermal properties were measured using an optical infrared scanning method on samples of cm-sizes with a flat, sawn surface. A database compiled from our measurements and literature data suggests that thermal diffusivities and conductivities at room temperature vary largely among samples even of the same petrologic and chemical type and overlap among, for example, different ordinary chondrite classes. Measured conductivities of ordinary chondrites vary from 0.4 to 5.1 W m(-1) K-1. On average, enstatite chondrites show much higher values (2.33-5.51 W m(-1) K-1) and carbonaceous chondrites lower values (0.5-2.55 W m(-1) K-1). Mineral composition (silicates versus iron-nickel) and porosity control conductivity. Porosity shows (linear) negative correlation with conductivity. Variable conductivity is attributed to heterogeneity in mineral composition and porosity by intra- and intergranular voids and cracks, which are important in the scale of typical meteorite samples. The effect of porosity may be even more significant for thermal properties than that of the metal content in chondrites.Peer reviewe
Low-level liquid scintillation spectrometer for Ăź-counting
A new liquid scintillation (LS) spectrometer has been developed. lt improves the signal to noise ratio of C-14 assays by an order of magnitude compared to conventional LS systems. As a result, precision for a modern sample is 0.2 % and the dating limit is 64 Ky BP for a 15 ml sample of benzene. Sophisticated MCA facilities allow the use of Multiparameter Multichannel Analysis for data validation and age evaluation. Despite the high sophistication, the spectrometer, (named QUANTULUS) is seif contained, microprocessor controlled and user friendly. lt can be used with full advantage in a normal laboratory environment
A Potential Biofilm Metabolite Signature for Caries Activity - A Pilot Clinical Study
BACKGROUND: This study's aim was to compare the dental biofilm metabolite-profile of caries-active (N=11) or caries-free (N=4) children by gas chromatography-mass spectrometry (GC/MS) analyses.
METHODS: Samples collected after overnight fasting, with or without a previous glucose rinse, were combined for each child based on the caries status of the site, re-suspended in ethanol and analyzed by GC/MS.
RESULTS: Biofilm from caries-active sites exhibited a different chromatographic profile compared to caries-free sites. Qualitative and quantitative analysis suggested a special cluster of branched alcohols and esters present at substantially higher intensity in biofilms of caries-active sites.
CONCLUSIONS: This pilot study indicates that there are metabolites present in the biofilm which have the potential to provide a characteristic metabolomics signature for caries activity
Stereospecific modulation of GABA(A) receptor function by urocanic acid isomers
A deamination product of histidine, urocanic acid, accumulates in the
skin of mammals as trans-urocanic acid. Ultraviolet (UV) irradition
converts it to the cis-isomer that is an important mediator in
UV-induced immunosuppression. We have recently shown that urocanic acid
interferes with the agonist binding to GABAA receptors. We now report
that the effects of urocanic acid on binding of a convulsant ligand
(t-butylbicyclo[35S]phosphorothionate) to GABAA receptors in brain
membrane homogenates are dependent on pH of the incubation medium, the
agonistic actions being enhanced at the normal pH of the skin (5.5).
Using Xenopus laevis oocytes expressing recombinant rat
alpha1beta1gamma2S GABAA receptors, the low pH potentiated the direct
agonistic action of trans-urocanic acid under two-electrode
voltage-clamp, whereas cis-urocanic acid retained its low efficacy both
at pH 5.5 and 7.4. The results thus indicate clear differences between
urocanic acid isomers in functional activity at one putative receptor
site of immunosuppression, the GABAA receptor, the presence of which
in the skin remains to be demonstrated.</p
Tools for BIM-GIS integration (IFC georeferencing and conversions): Results from the GeoBIM benchmark 2019
The integration of 3D city models with Building Information Models (BIM), coined as GeoBIM, facilitates improved data support to several applications, e.g., 3D map updates, building permits issuing, detailed city analysis, infrastructure design, context-based building design, to name a few. To solve the integration, several issues need to be tackled and solved, i.e., harmonization of features, interoperability, format conversions, integration of procedures. The GeoBIM benchmark 2019, funded by ISPRS and EuroSDR, evaluated the state of implementation of tools addressing some of those issues. In particular, in the part of the benchmark described in this paper, the application of georeferencing to Industry Foundation Classes (IFC) models and making consistent conversions between 3D city models and BIM are investigated, considering the OGC CityGML and buildingSMART IFC as reference standards. In the benchmark, sample datasets in the two reference standards were provided. External volunteers were asked to describe and test georeferencing procedures for IFC models and conversion tools between CityGML and IFC. From the analysis of the delivered answers and processed datasets, it was possible to notice that while there are tools and procedures available to support georeferencing and data conversion, comprehensive definition of the requirements, clear rules to perform such two tasks, as well as solid technological solutions implementing them, are still lacking in functionalities. Those specific issues can be a sensible starting point for planning the next GeoBIM integration agendas
GATA6 modulates the ductular reaction to bile duct ligation
Background GATA6, a transcription factor expressed in cholangiocytes, has been implicated in the response to liver injury. In biliary atresia, a disease characterized by extrahepatic bile duct obstruction, liver expression of GATA6 increases with pathological bile duct expansion and decreases after successful Kasai portoenterostomy. The aim of this study was to garner genetic evidence that GATA6 is involved in ductular formation/expansion. Methods The murine Gata6 gene was conditionally deleted using Alb-cre, a transgene expressed in hepatoblasts (the precursors of hepatocytes and cholangiocytes) and mature hepatocytes. Bile duct ligation (BDL) was used to model biliary obstruction. Results Alb-Cre;Gata6(flox/flox) mice were viable and fertile. Cre-mediated recombination of Gata6 in hepatocytes had little impact on cellular structure or function. GATA6 immunoreactivity was retained in a majority of biliary epithelial cells in adult Alb-Cre;Gata6(flox/flox) mice, implying that surviving cholangiocytes were derived from hepatoblasts that had escaped biallelic Cre-mediated recombination. Although GATA6 immunoreactivity was preserved in cholangiocytes, Alb-cre;Gata6(flox/flox) mice had a demonstrable biliary phenotype. A neutrophil-rich infiltrate surrounded newly formed bile ducts in neonatal Alb-Cre;Gata6(flox/flox) mice. Foci of fibrosis/necrosis, presumed to reflect patchy defects in bile duct formation, were observed in the livers of 37% of adult Alb-cre;Gata6(flox/flox) mice and 0% of controls (p <0.05). Most notably, Alb-cre;Gata6(flox/flox) mice had an altered response to BDL manifest as reduced survival, impaired bile ductule proliferation, increased parenchymal necrosis, reduced fibrosis, and enhanced macrophage accumulation in the portal space. Conclusions GATA6 orchestrates intrahepatic biliary remodeling and mitigates liver injury following extrahepatic bile duct obstruction. Graphic abstractPeer reviewe
Laboratory-based surveillance of COVID-19 in the Greater Helsinki area, Finland, February-June 2020
Objectives: The aim was to characterise age-and sex-specific severe acute respiratory syndrome coronavirus disease-2 (SARS-CoV-2) RT-PCR sampling frequency and positivity rate in Greater Helsinki area in Finland during February & ndash;June 2020. We also describe the laboratory capacity building for these diagnostics. Methods: Laboratory registry data for altogether 80,791 specimens from 70,517 individuals was analysed. The data included the date of sampling, sex, age and the SARS-CoV-2 RT-PCR test result on specimens collected between 1 February and 15 June 2020. Results: Altogether, 4057/80,791 (5.0%) of the specimens were positive and 3915/70,517 (5.6%) of the individuals were found positive. In all, 37% of specimens were from male and 67% from female subjects. While the number of positive cases was similar in male and female subjects, the positivity rate was significantly higher in male subjects: 7.5% of male and 4.4% of female subjects tested positive. The highest incidence/100,000 was observed in those aged >80 years. The proportion of young adults in positive cases increased in late May 2020. Large dips in testing frequency were observed during every weekend and also during public holidays. Conclusions: Our data suggest that men pursue SARS-CoV-2 testing less frequently than women. Consequently, a subset of coronavirus disease-2019 infections in men may have gone undetected. People sought testing less frequently on weekends and public holidays, and this may also lead to missing of positive cases. The proportion of young adults in positive cases increased towards the end of the study period, which may suggest their returning back to social behaviour with an increased risk of infection. (c) 2020 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-ncnd/4.0/).Peer reviewe
Pathological Investigation of Congenital Bicuspid Aortic Valve Stenosis, Compared with Atherosclerotic Tricuspid Aortic Valve Stenosis and Congenital Bicuspid Aortic Valve Regurgitation
Congenital bicuspid aortic valve (CBAV) is the main cause of aortic stenosis (AS) in young adults. However, the histopathological features of AS in patients with CBAV have not been fully investigated.We examined specimens of aortic valve leaflets obtained from patients who had undergone aortic valve re/placement at our institution for severe AS with CBAV (n = 24, CBAV-AS group), severe AS with tricuspid aortic valve (n = 24, TAV-AS group), and severe aortic regurgitation (AR) with CBAV (n = 24, CBAV-AR group). We compared the histopathological features among the three groups. Pathological features were classified using semi-quantitative methods (graded on a scale 0 to 3) by experienced pathologists without knowledge of the patients' backgrounds. The severity of inflammation, neovascularization, and calcium and cholesterol deposition did not differ between the CBAV-AS and TAV-AS groups, and these four parameters were less marked in the CBAV-AR group than in the CBAV-AS (all p<0.01). Meanwhile, the grade of valvular fibrosis was greater in the CBAV-AS group, compared with the TAV-AS and CBAV-AR groups (both p<0.01). In AS patients, thickness of fibrotic lesions was greater on the aortic side than on the ventricular side (both p<0.01). Meanwhile, thickness of fibrotic lesions was comparable between the aortic and ventricular sides in CBAV-AR patients (p = 0.35).Valvular fibrosis, especially on the aortic side, was greater in patients with CBAV-AS than in those without, suggesting a difference in the pathogenesis of AS between CBAV and TAV
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