Objective
To determine the presence and spatial distribution of different macrophage phenotypes, governed by granulocyte macrophage colony‐stimulating factor (GM‐CSF) and macrophage ...colony‐stimulating factor (M‐CSF) skewing signals, in giant cell arteritis (GCA) lesions.
Methods
Temporal artery biopsies (TABs, n = 11) from treatment‐naive GCA patients, aorta samples from GCA‐related aneurysms (n = 10) and atherosclerosis (n = 10) were stained by immunohistochemistry targeting selected macrophage phenotypic markers, cytokines, matrix metalloproteinases (MMPs) and growth factors. In vitro macrophage differentiation (n = 10) followed by flow cytometry, Luminex assay and ELISA were performed to assess whether GM‐CSF and M‐CSF are drivers of macrophage phenotypic heterogeneity.
Results
A distinct spatial distribution pattern of macrophage phenotypes in TABs was identified. CD206+/MMP‐9+ macrophages were located at the site of tissue destruction, whereas FRβ+ macrophages were located in the inner intima of arteries with high degrees of intimal hyperplasia. Notably, this pattern was also observed in macrophage‐rich areas in GCA aortas but not in atherosclerotic aortas. Flow cytometry showed that GM‐CSF treatment highly upregulated CD206 expression, while FRβ was expressed by M‐CSF‐skewed macrophages, only. Furthermore, localised expression of GM‐CSF and M‐CSF was detected, likely contributing to macrophage heterogeneity in the vascular wall.
Conclusions
Our data document a distinct spatial distribution pattern of CD206+/MMP‐9+ macrophages and FRβ+ macrophages in GCA linked to tissue destruction and intimal proliferation, respectively. We suggest that these distinct macrophage phenotypes are skewed by sequential GM‐CSF and M‐CSF signals. Our study adds to a better understanding of the development and functional role of macrophage phenotypes in the pathogenesis of GCA and opens opportunities for the design of macrophage‐targeted therapies.
In this study, we revealed a distinct spatial distribution of macrophage phenotypes in GCA‐affected vessel walls. CD206+/MMP‐9+ macrophages were located at the site of tissue destruction, whereas FRβ+ macrophages were located in the inner intima of arteries with high degrees of intimal hyperplasia. We suggest that these distinct macrophage phenotypes are skewed by sequential GM‐CSF and M‐CSF signals.
The transformation-deficient strain E26, isolated as a pHV60 insertion mutant, was used to isolate comK, a novel transcription unit required for genetic competence in Bacillus subtilis. Mutational ...analysis and sequence determination showed that comK contained one open reading frame (ORF), which could encode a protein of 192 amino acid residues with a predicted molecular weight of 22,500. An integrated copy of comK not only complemented the competence deficiency of a comK deletion mutant, but also that of strains E26 and FB93. Expression of comK occurred exclusively in glucose-based minimal medium during the transition to stationary growth phase. Furthermore, the expression of late competence genes appeared to be dependent on the gene product of comK, the expression of which in turn depended on the presence of a functional comL (or srfA) transcription unit. These epistatic interactions indicate that comK is a competence locus occupying an intermediate position in the competence signal transduction network. Primer extension analysis showed that comK has one major transcription start site, preceded by a sequence resembling the consensus promoter used by the sigma A form of RNA polymerase.
A general system is described that facilitates gene replacements such that the recombinant strains are not labelled with antibiotic resistance genes. The method is based on the conditional ...replication of derivatives of the lactococcal plasmid pWV01, which lacks the repA gene encoding the replication initiation protein. Replacement vectors can be constructed in and isolated from gram-positive and gram-negative helper strains that provide RepA in trans. Cointegrate formation of the integration vectors with the chromosome of the target strain is selected by antibiotic resistance. Resolution of the cointegrate structure is identified in the second step of the procedure by the loss of the lacZ reporter gene present in the delivery vector. The second recombination event results either in gene replacement or in restoration of the original copy of the gene. As no antibiotic resistance marker is present in the genome of the mutant the system can be used to introduce multiple mutations in one strain. A feasibility study was performed using Lactococcus lactis and Bacillus subtilis as model organisms. The results indicate that the method should be applicable to any non-essential gene in numerous bacterial species.
•An accelerated multislice algorithm (STEMcl) was developed.•Simulating series of large supercells is typical for defective and amorphous systems.•A new numerical approach is used to overcome the ...memory constraint limiting the maximum computable system size.•The contrast formation of vacancies/voids in STEM simulation are studied.•The detectability is discussed in terms of density changes.
Electron microscopy images are interference patterns and can generally not be interpreted in a straight forward manner. Typically, time consuming numerical simulations have to be employed to separate specimen features from imaging artifacts. Directly comparing numerical predictions to experimental results, realistic simulation box sizes and varying imaging parameters are needed. In this work, we introduce an accelerated multislice algorithm, named STEMcl, that is capable of simulating series of large super cells typical for defective and amorphous systems, in addition to parameter series using the massive parallelization accessible in today’s commercial PC-hardware, e.g. graphics processing units (GPUs). A new numerical approach is used to overcome the memory constraint limiting the maximum computable system size. This approach creates the possibility to study systematically the contrast formation arising by structural differences. STEM simulations of structure series of a crystalline Si and an amorphous CuZr system are presented and the contrast formation of vacancies/voids are studied. The detectability of vacancies/voids in STEM experiments is discussed in terms of density changes.
Gears are used under demanding conditions which lead to a continuous change of the tooth surface. With an increasing operation time, appearances of fatigue, like micropitting, can be noticed. ...Micropitting is characterized by micro-cracks in the surface. In some cases, these cracks grow or join to networks and in combination with subsurface caused stress intensities, e.g. at microstructural defects in the material, this leads to macroscopic pittings, which end the serviceability of a transmission.
This contribution defines micropitting and pitting and analyses their interaction and interdependency. A fatigue simulation for these mechanisms is introduced. Results of test rig trials and material analyses are presented and have been used to research these mechanisms, their interaction and also to validate the simulation.
•Description of the fatigue mechanisms micropitting and pitting on gear tooth flanks.•Explanation of the interaction and interdependency of micropitting and pitting.•Mathematical modelling of these mechanisms and their integration in a simulation.•Transferring of Lundberg/Palmgren fatigue approach for roller bearings to gears.•Validated simulation results for wear, micropitting and pitting on gears.
Methylenecyclobutanes are found to undergo Wacker oxidation via a semi‐pinacol‐type rearrangement. Key to a successful process is the use of tert‐butyl nitrite as oxidant, which not only enables ...efficient catalyst turn‐over but also ensures high Markovnikov‐selectivity under mild conditions. Thus, cyclopentanones (26 examples) can be accessed in an overall good yield and excellent selectivity (up to 97 % yield, generally >99 : 1 ketone:aldehyde ratio). Stereochemical analysis of the reaction sequence reveals migration aptitudes in line with related 1,2‐shifts. By introducing a pyox ligand to palladium, prochiral methylenecyclobutanes can be desymmetrized, thus realizing the first enantioselective Wacker oxidation.
Methylenecyclobutanes undergo Wacker oxidation towards cyclopentanones under mild reaction conditions. A semi‐pinacol‐type rearrangement is proposed to be responsible for the intermediary 1,2‐shift, which not only explains the formation of the products, but also rationalizes the reaction outcomes in terms of site‐, regio‐ and enantioselectivity.
A large body of evidence ascribes a pivotal role in emotion processing to the insular cortex. However, the complex structure and lateralization of emotional deficits following insular damage are not ...understood. Here, we investigated emotional ratings of valence and arousal and skin conductance responses (SCR) to a graded series of emotionally arousing scenes in patients with left (n = 10) or right (n = 9) insular damage and in healthy controls (n = 18). We found a significant reduction in overall SCRs, arousal ratings and valence extremity scores in right-lesioned patients, as compared to left-lesioned patients and healthy controls. The degree of right insular damage was significantly correlated with the degree of arousal, SCR and extremity attenuation. Additional analyses of correlations between subjective arousal ratings resp. SCR and normative arousal ratings revealed that both lesion groups had evaluative and physiological difficulties to discover changes in stimulus arousal. Although no group differences emerged on overall ratings of valence, analysis of correlations between subjective and normative valence ratings displayed markedly reduced accuracy in right-lesioned patients, as compared to left-lesioned patients and healthy controls. Our findings support the hypothesis that the left and right insulae subserve different functions in emotion processing, potentially due to asymmetrical representations of autonomic information in the left and right human forebrain. The right insula may serve as integral node for sympathetic arousal and cognitive-affective processing.
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