695 research outputs found
Prediction of final infarct volume from native CT perfusion and treatment parameters using deep learning
CT Perfusion (CTP) imaging has gained importance in the diagnosis of acute
stroke. Conventional perfusion analysis performs a deconvolution of the
measurements and thresholds the perfusion parameters to determine the tissue
status. We pursue a data-driven and deconvolution-free approach, where a deep
neural network learns to predict the final infarct volume directly from the
native CTP images and metadata such as the time parameters and treatment. This
would allow clinicians to simulate various treatments and gain insight into
predicted tissue status over time. We demonstrate on a multicenter dataset that
our approach is able to predict the final infarct and effectively uses the
metadata. An ablation study shows that using the native CTP measurements
instead of the deconvolved measurements improves the prediction.Comment: Accepted for publication in Medical Image Analysi
Characterization of Arabidopsis enhanced disease susceptibility mutants that are affected in systemically induced resistance
In Arabidopsis, the rhizobacterial strain Pseudomonas fluorescens WCS417r triggers jasmonate (JA)- and
ethylene (ET)-dependent induced systemic resistance (ISR) that is effective against different pathogens.
Arabidopsis genotypes unable to express rhizobacteria-mediated ISR against the bacterial pathogen
Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) exhibit enhanced disease susceptibility towards
this pathogen. To identify novel components controlling induced resistance, we tested 11 Arabidopsis
mutants with enhanced disease susceptibility (eds) to pathogenic P. syringae bacteria for WCS417rmediated
ISR and pathogen-induced systemic acquired resistance (SAR). Mutants eds4-1, eds8-1 and
eds10-1 failed to develop WCS417r-mediated ISR, while mutants eds5-1 and eds12-1 failed to express
pathogen-induced SAR. Whereas eds5-1 is known to be blocked in salicylic acid (SA) biosynthesis,
analysis of eds12-1 revealed that its impaired SAR response is caused by reduced sensitivity to this
molecule. Analysis of the ISR-impaired eds mutants revealed that they are non-responsive to induction
of resistance by methyl jasmonate (MeJA) (eds4-1, eds8-1 and eds10-1), or the ET precursor 1-
aminocyclopropane-1-carboxylate (ACC) (eds4-1 and eds10-1). Moreover, eds4-1 and eds8-1 showed
reduced expression of the plant defensin gene PDF1.2 after MeJA and ACC treatment, which was
associated with reduced sensitivity to either ET (eds4-1) or MeJA (eds8-1). Although blocked in
WCS417r-, MeJA- and ACC-induced ISR, eds10-1 behaved normally for several other responses to MeJA
or ACC. The results indicate that EDS12 is required for SAR and acts downstream of SA, whereas EDS4,
EDS8 and EDS10 are required for ISR acting either in JA signalling (EDS8), ET signalling (EDS4), or
downstream JA and ET signalling (EDS10) in the ISR pathway
Increasing the Brønsted acidity of Ph2PO2H by the Lewis acid B(C6F5)3. Formation of an eight-membered boraphosphinate ring [Ph2POB(C6F5)2O]2
The Deutsche Forschungsgemeinschaft (DFG) is gratefully acknowledged for financial support. The theoretical part of this work was supported by the Russian Science Foundation (Project 14-13-00832).Autoprotolysis of the metastable acid (C6F5)3BOPPh2OH, prepared in situ by the reaction of the rather weak Brønsted acid Ph2PO2H with the strong Lewis acid B(C6F5)3, gave rise to the formation of the eight-membered ring [Ph2POB(C6F5)2O]2 and C6F5H. The conjugate base was isolated as stable sodium crown ether salt [Na(15-crown-5)][Ph2PO2B(C6F5)3].Publisher PDFPeer reviewe
Changes in globus pallidus with (pre)term kernicterus
OBJECTIVE: We report serial magnetic resonance (MR) and sonographic
behavior of globus pallidus in 5 preterm and 3 term infants with
kernicterus and describe the clinical context in very low birth weight
preterm infants. On the basis of this information, we suggest means of
diagnosis and prevention. METHODS: Charts and MR and ultrasound images of
5 preterm infants and 3 term infants with suspected bilirubin-associated
brain damage were reviewed. Included were preterm infants with severe
hearing loss, quadriplegic hypertonia, and abnormal hypersignal of globus
pallidus on T2-weighted MR imaging (MRI). In 1 infant who died on day 150,
the diagnosis was confirmed during the neonatal period. The others were
picked up as outpatients and scanned at 12 or 22 months' corrected age.
Three instances of term kernicterus were included for comparison of serial
MRI in the neonatal period and early infancy: they were caused by
glucose-6-phosphate dehydrogenase deficiency, urosepsis, and dehydration
plus fructose 1-6 biphosphatase deficiency. RESULTS: Five preterm infants
of 25 to 29 weeks' gestational age presented with total serum bilirubin
(TSB) levels below exchange transfusion thresholds commonly advised. Mixed
acidosis was present in 3 infants around the TSB peak. The
bilirubin/albumin molar ratio was >0.5 in all, in the absence of
displacing drugs. All failed to pass bedside hearing screen tests and had
severe hearing loss on auditory brain response testing. Symmetrical
homogeneous hyperechogenicity of globus pallidus was the alerting feature
in 1 infant. Globus pallidus was hyperintense on T1-weighted MR images in
this child. The other infants presented with severe developmental delay as
a result of dyskinetic quadriplegia and hearing loss. Globus pallidus was
normal on T1- but hyperintense on T2-weighted MR images at 12
Literator 2010: Daniel Kehlmann. Dozentur für Weltliteratur
"Sollen doch die Literaturwissenschaftler sich damit beschäftigen, etwas Übersehenes zu finden, der Literat aber darf sich auch einmal den Luxus erlauben, über das Beliebteste zu sprechen, also jenes weltgewinnende Werk, das für immer das Bild eines Kontinents verändert hat. Südamerika, so ließ García Márquez einst jemanden in seiner frühen Novelle Der Oberst hat niemand, der ihm schreibt klagen, das sei für die meisten Menschen doch nur ein Mann mit Schnurrbart, Gitarre und Pistole. Das stimmte dereinst sicher, aber heute ist Südamerika eher ein unheimliches Haus, umgeben von Moor und buntem Regenwald, ein Land bizarrer und melancholischer Wunder. Unsere Vorstellungen sind hier so sehr durch einen einzigen Roman geprägt, dass wir es kaum mehr bemerken." Daniel Kehlman
Strain-dependent host transcriptional responses to toxoplasma infection are largely conserved in mammalian and avian hosts
Toxoplasma gondii has a remarkable ability to infect an enormous variety of mammalian and avian species. Given this, it is surprising that three strains (Types I/II/III) account for the majority of isolates from Europe/North America. The selective pressures that have driven the emergence of these particular strains, however, remain enigmatic. We hypothesized that strain selection might be partially driven by adaptation of strains for mammalian versus avian hosts. To test this, we examine in vitro, strain-dependent host responses in fibroblasts of a representative avian host, the chicken (Gallus gallus). Using gene expression profiling of infected chicken embryonic fibroblasts and pathway analysis to assess host response, we show here that chicken cells respond with distinct transcriptional profiles upon infection with Type II versus III strains that are reminiscent of profiles observed in mammalian cells. To identify the parasite drivers of these differences, chicken fibroblasts were infected with individual F1 progeny of a Type II x III cross and host gene expression was assessed for each by microarray. QTL mapping of transcriptional differences suggested, and deletion strains confirmed, that, as in mammalian cells, the polymorphic rhoptry kinase ROP16 is the major driver of strain-specific responses. We originally hypothesized that comparing avian versus mammalian host response might reveal an inversion in parasite strain-dependent phenotypes; specifically, for polymorphic effectors like ROP16, we hypothesized that the allele with most activity in mammalian cells might be less active in avian cells. Instead, we found that activity of ROP16 alleles appears to be conserved across host species; moreover, additional parasite loci that were previously mapped for strain-specific effects on mammalian response showed similar strain-specific effects in chicken cells. These results indicate that if different hosts select for different parasite genotypes, the selection operates downstream of the signaling occurring during the beginning of the host's immune response. © 2011 Ong et al
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