147 research outputs found
Sarcopenia Is a Negative Prognostic Factor in Patients Undergoing Transarterial Chemoembolization (TACE) for Hepatic Malignancies
Background and Aims: While transarterial chemoembolization (TACE) represents a
standard of therapy for intermediate-stage hepatocellular carcinoma (HCC) and is also routinely
performed in patients with liver metastases, it is still debated which patients represent the ideal
candidates for TACE therapy in terms of overall survival. Sarcopenia, the degenerative loss of skeletal
muscle mass and strength, has been associated with an adverse outcome for various malignancies,
but its role in the context of TACE has largely remained unknown. Here, we evaluated the role of
sarcopenia on the outcome of patients undergoing TACE for primary and secondary liver cancer.
Methods: The patients’ psoas muscle size was measured on axial computed tomography (CT)
scans and normalized for the patients’ height squared. This value was referred to as the psoas
muscle index (PMI). The PMI was correlated with clinical and laboratory markers. Results: While
pre-interventional sarcopenia had no impact on the direct tumor response to TACE, sarcopenic patients
with a pre-interventional PMI below our ideal cut-o value of 13.39 mm/m2 had a significantly
impaired long-term outcome with a median overall survival of 491 days compared to 1291 days
for patients with a high PMI. This finding was confirmed by uni- and multivariate Cox-regression
analyses. Moreover, a progressive rapid decline in muscle mass after TACE was a predictor for
an unfavorable prognosis. Conclusion: Our data suggest that sarcopenia represents a previously
unrecognized prognostic factor for patients undergoing TACE therapy which might yield important
information on the patients’ post-interventional outcome and should therefore be implemented into
clinical stratification algorithms
A common approach for absolute quantification of short chain CoA thioesters in prokaryotic and eukaryotic microbes
Background
Thioesters of coenzyme A participate in 5% of all enzymatic reactions. In microbial cell factories, they function as building blocks for products of recognized commercial value, including natural products such as polyketides, polyunsaturated fatty acids, biofuels, and biopolymers. A core spectrum of approximately 5–10 short chain thioesters is present in many microbes, as inferred from their genomic repertoire. The relevance of these metabolites explains the high interest to trace and quantify them in microbial cells.
Results
Here, we describe a common workflow for extraction and absolute quantification of short chain CoA thioesters in different gram-positive and gram-negative bacteria and eukaryotic yeast, i.e. Corynebacterium glutamicum, Streptomyces albus, Pseudomonas putida, and Yarrowia lipolytica. The approach assessed intracellular CoA thioesters down to the picomolar level and exhibited high precision and reproducibility for all microbes, as shown by principal component analysis. Furthermore, it provided interesting insights into microbial CoA metabolism. A succinyl-CoA synthase defective mutant of C. glutamicum exhibited an unaffected level of succinyl-CoA that indicated a complete compensation by the L-lysine pathway to bypass the disrupted TCA cycle. Methylmalonyl-CoA, an important building block of high-value polyketides, was identified as dominant CoA thioester in the actinomycete S. albus. The microbe revealed a more than 10,000-fold difference in the abundance of intracellular CoA thioesters. A recombinant strain of S. albus, which produced different derivatives of the antituberculosis polyketide pamamycin, revealed a significant depletion of CoA thioesters of the ethylmalonyl CoA pathway, influencing product level and spectrum.
Conclusions
The high relevance of short chain CoA thioesters to synthetize industrial products and the interesting insights gained from the examples shown in this work, suggest analyzing these metabolites in microbial cell factories more routinely than done so far. Due to its broad application range, the developed approach appears useful to be applied this purpose. Hereby, the possibility to use one single protocol promises to facilitate automatized efforts, which rely on standardized workflows
Microparticles globally reprogram Streptomyces albus toward accelerated morphogenesis, streamlined carbon core metabolism, and enhanced production of the antituberculosis polyketide pamamycin
Streptomyces spp. are a rich source for natural products with recognized industrial value, explaining the high interest to improve and streamline the performance of in these microbes. Here, we studied the production of pamamycins, macrodiolide homologs with a high activity against multiresistant pathogenic microbes, using recombinant Streptomyces albus J1074/R2. Talc particles (hydrous magnesium silicate, 3MgO·4SiO2·H2O) of micrometer size, added to submerged cultures of the recombinant strain, tripled pamamycin production up to 50 mg/L. Furthermore, they strongly affected morphology, reduced the size of cell pellets formed by the filamentous microbe during the process up to sixfold, and shifted the pamamycin spectrum to larger derivatives. Integrated analysis of transcriptome and precursor (CoA thioester) supply of particle‐enhanced and control cultures provided detailed insights into the underlying molecular changes. The microparticles affected the expression of 3,341 genes (56% of all genes), revealing a global and fundamental impact on metabolism. Morphology‐associated genes, encoding major regulators such as SsgA, RelA, EshA, Factor C, as well as chaplins and rodlins, were found massively upregulated, indicating that the particles caused a substantially accelerated morphogenesis. In line, the pamamycin cluster was strongly upregulated (up to 1,024‐fold). Furthermore, the microparticles perturbed genes encoding for CoA‐ester metabolism, which were mainly activated. The altered expression resulted in changes in the availability of intracellular CoA‐esters, the building blocks of pamamycin. Notably, the ratio between methylmalonyl CoA and malonyl‐CoA was increased fourfold. Both metabolites compete for incorporation into pamamycin so that the altered availability explained the pronounced preference for larger derivatives in the microparticle‐enhanced process. The novel insights into the behavior of S. albus in response to talc appears of general relevance to further explore and upgrade the concept of microparticle enhanced cultivation, widely used for filamentous microbes
Virulence-associated genes, resistance genes and adhesion and probiotic activity tested by a new screening method
We established an automated screening method to characterize adhesion of
Escherichia coli to intestinal porcine epithelial cells (IPEC-J2) and their
probiotic activity against infection by enteropathogenic E. coli (EPEC). 104
intestinal E. coli isolates from domestic pigs were tested by PCR for the
occurrence of virulence-associated genes, genes coding for resistances to
antimicrobial agents and metals, and for phylogenetic origin by PCR. Adhesion
rates and probiotic activity were examined for correlation with the presence
of these genes. Finally, data were compared with those from 93 E. coli
isolates from wild boars. Isolates from domestic pigs carried a broad variety
of all tested genes and showed great diversity in gene patterns. Adhesions
varied with a maximum of 18.3 or 24.2 mean bacteria adherence per epithelial
cell after 2 or 6 hours respectively. Most isolates from domestic pigs and
wild boars showed low adherence, with no correlation between
adhesion/probiotic activity and E. coli genes or gene clusters. The gene
sfa/foc, encoding for a subunit of F1C fimbriae did show a positive
correlative association with adherence and probiotic activity; however E. coli
isolates from wild boars with the sfa/foc gene showed less adhesion and
probiotic activity than E. coli with the sfa/foc gene isolated from domestic
pigs after 6 hour incubation. In conclusion, screening porcine E. coli for
virulence associated genes genes, adhesion to intestinal epithelial cells, and
probiotic activity revealed a single important adhesion factor, several
probiotic candidates, and showed important differences between E. coli of
domestic pigs and wild boars
Porcine E. coli: Virulence-Associated Genes, Resistance Genes and Adhesion and Probiotic Activity Tested by a New Screening Method
We established an automated screening method to characterize adhesion of Escherichia colito intestinal porcine epithelial cells (IPEC-J2) and their probiotic activity against infection by enteropathogenic E. coli (EPEC). 104 intestinal E. coli isolates from domestic pigs were tested by PCR for the occurrence of virulence-associated genes, genes coding for resistances to antimicrobial agents and metals, and for phylogenetic origin by PCR. Adhesion rates and probiotic activity were examined for correlation with the presence of these genes. Finally, data were compared with those from 93 E. coli isolates from wild boars.
Isolates from domestic pigs carried a broad variety of all tested genes and showed great diversity in gene patterns. Adhesions varied with a maximum of 18.3 or 24.2 mean bacteria adherence per epithelial cell after 2 or 6 hours respectively. Most isolates from domestic pigs and wild boars showed low adherence, with no correlation between adhesion/probiotic activity and E. coli genes or gene clusters. The gene sfa/foc, encoding for a subunit of F1C fimbriae did show a positive correlative association with adherence and probiotic activity; however E. coliisolates from wild boars with the sfa/foc gene showed less adhesion and probiotic activity thanE. coli with the sfa/foc gene isolated from domestic pigs after 6 hour incubation.
In conclusion, screening porcine E. coli for virulence associated genes genes, adhesion to intestinal epithelial cells, and probiotic activity revealed a single important adhesion factor, several probiotic candidates, and showed important differences between E. coli of domestic pigs and wild boars
Auditory Cortical Detection and Discrimination Correlates with Communicative Significance
Plasticity studies suggest that behavioral relevance can change the cortical processing of trained or conditioned sensory stimuli. However, whether this occurs in the context of natural communication, where stimulus significance is acquired through social interaction, has not been well investigated, perhaps because neural responses to species-specific vocalizations can be difficult to interpret within a systematic framework. The ultrasonic communication system between isolated mouse pups and adult females that either do or do not recognize the calls' significance provides an opportunity to explore this issue. We applied an information-based analysis to multi- and single unit data collected from anesthetized mothers and pup-naïve females to quantify how the communicative significance of pup calls affects their encoding in the auditory cortex. The timing and magnitude of information that cortical responses convey (at a 2-ms resolution) for pup call detection and discrimination was significantly improved in mothers compared to naïve females, most likely because of changes in call frequency encoding. This was not the case for a non-natural sound ensemble outside the mouse vocalization repertoire. The results demonstrate that a sensory cortical change in the timing code for communication sounds is correlated with the vocalizations' behavioral relevance, potentially enhancing functional processing by improving its signal to noise ratio
Protective immune trajectories in early viral containment of non-pneumonic SARS-CoV-2 infection
The antiviral immune response to SARS-CoV-2 infection can limit viral spread and prevent development of pneumonic COVID-19. However, the protective immunological response associated with successful viral containment in the upper airways remains unclear. Here, we combine a multi-omics approach with longitudinal sampling to reveal temporally resolved protective immune signatures in non-pneumonic and ambulatory SARS-CoV-2 infected patients and associate specific immune trajectories with upper airway viral containment. We see a distinct systemic rather than local immune state associated with viral containment, characterized by interferon stimulated gene (ISG) upregulation across circulating immune cell subsets in non-pneumonic SARS-CoV2 infection. We report reduced cytotoxic potential of Natural Killer (NK) and T cells, and an immune-modulatory monocyte phenotype associated with protective immunity in COVID-19. Together, we show protective immune trajectories in SARS-CoV2 infection, which have important implications for patient prognosis and the development of immunomodulatory therapies
A search for resonances decaying into a Higgs boson and a new particle X in the XH→qqbb final state with the ATLAS detector
A search for heavy resonances decaying into a Higgs boson () and a new particle () is reported, utilizing 36.1 fb of proton-proton collision data at 13 TeV collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle is assumed to decay to a pair of light quarks, and the fully hadronic final state is analysed. The search considers the regime of high resonance masses, where the and bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of mass versus mass is scanned for evidence of a signal, over a range of resonance mass values between 1 TeV and 4 TeV, and for particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of and masses, on the production cross-section of the resonance
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