118 research outputs found

    Католицька концепція міжрелігійного діалогу: зміна акцентів

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    In Arabidopsis roots, the transcription factor MYB72 plays a dual role in the onset of rhizobacteria-induced systemic resistance (ISR) and plant survival under conditions of limited iron availability. Previously, it was shown that MYB72 coordinates the expression of a gene module that promotes synthesis and excretion of iron-mobilizing phenolic compounds in the rhizosphere, a process involved in both iron acquisition and ISR signaling. Here, we show that volatile compounds (VOCs) from ISR-inducing Pseudomonas bacteria are important elicitors of MYB72. VOCs-induced MYB72 is co-expressed with the iron uptake-related genes FERRIC REDUCTION OXIDASE 2 (FRO2) and IRON-REGULATED TRANSPORTER 1 (IRT1) in a FER-LIKE IRON DEFICIENCY INDUCED TRANSCRIPTION FACTOR (FIT)-dependent manner, indicating that MYB72 is an intrinsic part of the plants’ iron acquisition response that is typically activated upon iron starvation. However, VOCs-induced MYB72 is activated independently of the iron availability in the root vicinity. Moreover, rhizobacterial VOCs-mediated induction of MYB72 requires photosynthesis-related signals, while iron deficiency in the rhizosphere can activate MYB72 in the absence of shoot-derived signals. Together, these results show that the ISR- and iron acquisition-related transcription factor MYB72 in Arabidopsis roots is activated by rhizobacterial volatiles and photosynthesis-related signals, and can enhance the iron acquisition capacity of roots independently of the iron availability in the rhizosphere. This work highlights the role of MYB72 in plant processes by which root microbiota simultaneously stimulate systemic immunity and activate the iron uptake machinery in their host plants

    The definition of low wall shear stress and its effect on plaque progression estimation in human coronary arteries

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    Wall shear stress (WSS), the frictional force of the blood on the vessel wall, plays a crucial role in atherosclerotic plaque development. Low WSS has been associated with plaque growth, however previous research used different approaches to define low WSS to investigate its effect on plaque progression. In this study, we used four methodologies to allocate low, mid and high WSS in one dataset of human coronary arteries and investigated the predictive power of low WSS for plaque progression. Coronary reconstructions were based on multimodality imaging, using intravascular ultrasound and CT-imaging. Vessel-specific flow was measured using Doppler wire and computational fluid dynamics was performed to calculate WSS. The absolute WSS range varied greatly between the coronary arteries. On the population level, the established pattern of most plaque progression at low WSS was apparent in all methodologies defining the WSS categories. However, for the individual patient, when using measured flow to determine WSS, the absolute WSS values range so widely, that the use of absolute thresholds to determine low WSS was not appropriate to identify regions at high risk for plaque progression

    Cardiologist and cardiac surgeon view on decision-making in prosthetic aortic valve selection: Does profession matter?

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    Aims Assess and compare among Dutch cardiothoracic surgeons and cardiologists: opinion on (1) patient involvement, (2) conveying risk in aortic valve selection, and (3) aortic valve preferences. Methods and results A survey among 117 cardiothoracic surgeons and cardiologists was conducted. Group responses were compared using the Mann-Whitney U test. Most respondents agreed that patients should be involved in decision-making, with surgeons leaning more toward patient involvement (always: 83 % versus 50 % respectively; p < 0.01) than cardiologists. Most respondents found that ideally doctors and patients should decide together, with cardiologists leaning more toward taking the lead compared with surgeons (p < 0.01). Major risks of the therapeutic options were usually discussed with patients, and less common complications to a lesser extent. A wide variation in valve preference was noted with cardiologists leaning more toward mechanical prostheses, while surgeons more often preferred bioprostheses (p < 0.05). Conclusion Patient involv

    Changes in small intestinal homeostasis, morphology, and gene expression during rotavirus infection of infant mice

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    Rotavirus is the most important cause of infantile gastroenteritis. Since in vivo mucosal responses to a rotavirus infection thus far have not been extensively studied, we related viral replication in the murine small intestine to alterations in mucosal structure, epithelial cell homeostasis, cellular kinetics, and differentiation. Seven-day-old suckling BALB/c mice were inoculated with 2 x 10(4) focus-forming units of murine rotavirus and were compared to mock-infected controls. Diarrheal illness and viral shedding were recorded, and small intestinal tissue was evaluated for rotavirus (NSP4 and structural proteins)- and enterocyte-specific (lactase, SGLT1, and L-FABP) mRNA and protein expression. Morphology, apoptosis, proliferation, and migration were evaluated (immuno)histochemically. Diarrhea was observed from days 1 to 5 postinfection, and viral shedding was observed from days 1 to 10. Two peaks of rotavirus replication were observed at 1 and 4 days postinfection. Histological changes were characterized by the accumulation of vacuolated enterocytes. Strikingly, the number of vacuolated cells exceeded the number of cells in which viral replication was detectable. Apoptosis and proliferation were increased from days 1 to 7, resulting in villous atrophy. Epithelial cell turnover was significantly higher (<4 days) than that observed in controls (7 days). Since epithelial renewal occurred within 4 days, the second peak of viral replication was most likely caused by infection of newly synthesized cells. Expression of enterocyte-specific genes was downregulated in infected cells at mRNA and protein levels starting as early as 6 h after infection. In conclusion, we show for the first time that rotavirus infection induces apoptosis in vivo, an increase in epithelial cell turnover, and a shutoff of gene expression in enterocytes showing viral replication. The shutoff of enterocyte-specific gene expression, together with the loss of mature enterocytes through apoptosis and the replacement of these cells by less differentiated dividing cells, likely leads to a defective absorptive function of the intestinal epithelium, which contributes to rotavirus pathogenesis

    Lipid-rich Plaques Detected by Near-infrared Spectroscopy Are More Frequently Exposed to High Shear Stress

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    High wall shear stress (WSS) and near-infrared spectroscopy (NIRS) detected lipid-rich plaque (LRP) are both known to be associated with plaque destabilization and future adverse cardiovascular events. However, knowledge of spatial co-localization of LRP and high WSS is lacking. This study investigated the co-localization of LRP based on NIRS and high WSS. Fifty-three patients presenting acute coronary syndrome underwent NIRS-intravascular-ultrasound (NIRS-IVUS) imaging of a non-culprit coronary artery. WSS was obtained using WSS profiling in 3D-reconstructions of the coronary arteries based on fusion of IVUS-segmented lumen and CT-derived 3D-centerline. Thirty-eight vessels were available for final analysis and divided into 0.5 mm/45° sectors. LRP sectors, as identified by NIRS, were more often colocalized with high WSS than sectors without LRP. Moreover, there was a dose-dependent relationship between lipid content and high WSS exposure. This study is a first step in understanding the evolution of LRPs to vulnerable plaques. [Figure not available: see fulltext.

    Endoplasmic Reticulum Stress, Unfolded Protein Response and Altered T Cell Differentiation in Necrotizing Enterocolitis

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    Background:Endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) play important roles in chronic intestinal inflammation. Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in preterm infants and is characterized by acute intestinal inflammation and necrosis. The objective of the study is to investigate the role of ER stress and the UPR in NEC patients.Methods:Ileal tissues from NEC and control patients were obtained during surgical resection and/or at stoma closure. Splicing of XBP1 was detected using PCR, and gene expression was quantified using qPCR and Western blot.Results:Splicing of XBP1 was only detected in a subset of acute NEC (A-NEC) patients, and not in NEC patients who had undergone reanastomosis (R-NEC). The other ER stress and the UPR pathways, PERK and ATF6, were not activated in NEC patients. A-NEC patients showing XBP1 splicing (A-NEC-XBP1s) had increased mucosal expression of GRP78, CHOP, IL6 and IL8. Similar results were obtained by inducing ER stress and the UPR in vitro. A-NEC-XBP1s patients showed altered T cell differentiation indicated by decreased mucosal expression of RORC, IL17A and FOXP3. A-NEC-XBP1s patients additionally showed more severe morphological damage and a worse surgical outcome. Compared with A-NEC patients, R-NEC patients showed lower mucosal IL6 and IL8 expression and higher mucosal FOXP3 expression.Conclusions:XBP1 splicing, ER stress and the UPR in NEC are associated with increased IL6 and IL8 expression levels, altered T cell differentiation and severe epithelial injury

    Aortic geometry and long-term outcome in patients with a repaired coarctation

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    Objective This study aims to compare aortic morphology between repaired coarctation patients and controls, and to identify aortic morphological risk factors for hypertension and cardiovascular events (CVEs) in coarctation patients. Methods Repaired coarctation patients with computed tomography angiography (CTA) or magnetic resonance angiography (MRA) were included, followed-up and compared with sex-matched and age-matched controls. Three-dimensional aortic shape was reconstructed using patients' CTA or MRA, or four-dimensional flow cardiovascular magnetic resonance in controls, and advanced geometrical characteristics were calculated and visualised using statistical shape modelling. In patients, we examined the association of geometrical characteristics with (1) baseline hypertension, using multivariable logistic regression; and (2) cardiovascular events (CVE, composite of aortic complications, coronary artery disease, ventricular arrhythmias, heart failure hospitalisation, stroke, transient ischaemic attacks and cardiovascular death), using multivariable Cox regression. The least absolute shrinkage and selection operator (LASSO) method selected the most informative multivariable model. Results Sixty-five repaired coarctation patients (23 years (IQR 19-38)) were included, of which 44 (68%) patients were hypertensive at baseline. After a median follow-up of 8.7 years (IQR 4.8-15.4), 27 CVEs occurred in 20 patients. Aortic arch dimensions were smaller in patients compared with controls (diameter p&lt;0.001, wall surface area p=0.026, volume p=0.007). Patients had more aortic arch torsion (p&lt;0.001) and a higher curvature (p&lt;0.001). No geometrical characteristics were associated with hypertension. LASSO selected left ventricular mass, male sex, tortuosity and age for the multivariable model. Left ventricular mass (p=0.014) was independently associated with CVE, and aortic tortuosity showed a trend towards significance (p=0.070). Conclusion Repaired coarctation patients have a smaller aortic arch and a more tortuous course of the aorta compared with controls. Besides left ventricular mass index, geometrical features might be of importance in long-term risk assessment in coarctation patients.</p

    Aortic geometry and long-term outcome in patients with a repaired coarctation

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    Objective This study aims to compare aortic morphology between repaired coarctation patients and controls, and to identify aortic morphological risk factors for hypertension and cardiovascular events (CVEs) in coarctation patients. Methods Repaired coarctation patients with computed tomography angiography (CTA) or magnetic resonance angiography (MRA) were included, followed-up and compared with sex-matched and age-matched controls. Three-dimensional aortic shape was reconstructed using patients' CTA or MRA, or four-dimensional flow cardiovascular magnetic resonance in controls, and advanced geometrical characteristics were calculated and visualised using statistical shape modelling. In patients, we examined the association of geometrical characteristics with (1) baseline hypertension, using multivariable logistic regression; and (2) cardiovascular events (CVE, composite of aortic complications, coronary artery disease, ventricular arrhythmias, heart failure hospitalisation, stroke, transient ischaemic attacks and cardiovascular death), using multivariable Cox regression. The least absolute shrinkage and selection operator (LASSO) method selected the most informative multivariable model. Results Sixty-five repaired coarctation patients (23 years (IQR 19-38)) were included, of which 44 (68%) patients were hypertensive at baseline. After a median follow-up of 8.7 years (IQR 4.8-15.4), 27 CVEs occurred in 20 patients. Aortic arch dimensions were smaller in patients compared with controls (diameter p&lt;0.001, wall surface area p=0.026, volume p=0.007). Patients had more aortic arch torsion (p&lt;0.001) and a higher curvature (p&lt;0.001). No geometrical characteristics were associated with hypertension. LASSO selected left ventricular mass, male sex, tortuosity and age for the multivariable model. Left ventricular mass (p=0.014) was independently associated with CVE, and aortic tortuosity showed a trend towards significance (p=0.070). Conclusion Repaired coarctation patients have a smaller aortic arch and a more tortuous course of the aorta compared with controls. Besides left ventricular mass index, geometrical features might be of importance in long-term risk assessment in coarctation patients.</p

    Mucin Muc2 Deficiency and Weaning Influences the Expression of the Innate Defense Genes Reg3β, Reg3γ and Angiogenin-4

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    Background Mucin Muc2 is the structural component of the intestinal mucus layer. Absence of Muc2 leads to loss of this layer allowing direct bacterial-epithelial interactions. We hypothesized that absence of the mucus layer leads to increased expression of innate defense peptides. Specifically, we aimed to study the consequence of Muc2 deficiency (Muc2-/-) on the expression of regenerating islet-derived protein 3 beta (Reg3ß), regenerating islet-derived protein 3 gamma (Reg3¿), and angiogenin-4 (Ang4) in the intestine shortly before and after weaning. Methods Intestinal tissues of Muc2-/- and wild-type (WT) mice were collected at postnatal day 14 (P14, i.e. pre-weaning) and P28 (i.e. post-weaning). Reg3ß, Reg3¿, and Ang4 expression was studied by quantitative real-time PCR, Western-blot, in situ hybridization, and immunohistochemistry. Results Reg3ß and Reg3¿ were expressed by diverging epithelial cell types; namely enterocytes, Paneth cells, and goblet cells. Additionally, Ang4 expression was confined to Paneth cells and goblet cells. Expression of Reg3ß, Reg3¿, and Ang4 differed between WT and Muc2-/- mice before and after weaning. Interestingly, absence of Muc2 strongly increased Reg3ß and Reg3¿ expression in the small intestine and colon. Finally, morphological signs of colitis were only observed in the distal colon of Muc2-/- mice at P28, where and when expression levels of Reg3ß, Reg3¿, and Ang4 were the lowest. Conclusions Expression of Reg3 proteins and Ang4 by goblet cells point to an important role for goblet cells in innate defense. Absence of Muc2 results in up-regulation of Reg3ß and Reg3¿ expression, suggesting altered bacterial-epithelial signaling and an innate defense response in Muc2-/- mice. The inverse correlation between colitis development and Reg3ß, Reg3¿, and Ang4 expression levels might point toward a role for these innate defense peptides in regulating intestinal inflammatio
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