Proximal true lumen collapse in a chronic type B aortic dissection patient:A case report

BACKGROUND In the context of aortic dissection,increasing pressure within the newly formed false lumen can result in the progressive compression of the true aortic channel.However,true lumen collapse in chronic type B aortic dissection(cTBAD)patients is rare,with few clinical or experimental studies to date having explored the causes of such collapse.CASE SUMMARY In the present report,we describe a rare case of true-lumen collapse in an 83-yearold patient diagnosed with cTBAD,and we discuss potential therapeutic interventions for such cases.Following thoracic endovascular aortic repair(TEVAR),computed tomography angiography revealed satisfactory stent-graft positioning,no endoleakage,true lumen enlargement,thrombus formation in the false lumen,and slight enlargement of the true lumen distal to the stent-graft.Computational hemodynamic analyses indicated that the wall shear stress and pressure within the false lumen were significantly reduced following TEVAR.CONCLUSION TEVAR treatment of cTBAD patients suffering from proximal true lumen collapse can facilitate some degree of effective remodeling.

Icariin protects vascular endothelial cells from oxidative stress through inhibiting endoplasmic reticulum stress

Objective: To investigate the protective effect and underlying mechanism(s) of icariin(ICA) in preventing hydrogen peroxide(H_2O_2)-induced vascular endothelial cell injury via endoplasmic reticulum stress(ERS).Methods: To study the effects of ICA on H_2O_2-induced damage, we used the cell counting kit-8 assay to detect cell viability and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay to determine cell adhesion and apoptosis, respectively. Spectrophotometry and enzyme-linked immunosorbent assay were used to measure the expression levels of superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px). Subsequently, glucose-regulated protein 78(GRP78), activating transcription factor-4(ATF4) and eukaryotic initiation factor-2 a(eIF2 a) were detected using Western blotting.Results: In human umbilical vein endothelial cells, different concentrations of ICA exhibited multiple effects, including reduced H_2O_2 damage, improved cell viability and adhesion, reduced cell apoptosis and increased SOD and GSH-Px activity. Among the ICA concentrations used, only the H_2O_2+ 100 lmol/L ICA group had significant differences compared to the H_2O_2 group. ERS activators H_2O_2 and DL-dithiothreitol(DTT) significantly increased GRP78, ATF4 and eIF2 a expressions, decreased cell activity and reduced SOD and GSH-Px activity. In contrast, the H_2O_2+ 100 lmol/L ICA and H_2O_2+ 100 lmol/L ICA + DTT groups had significant inhibitory effects on the expressions of GRP78,ATF4 and eIF2 a proteins, showing enhanced cell viability and SOD and GSH-Px activity.Conclusion: The results showed the dose-dependent effects of ICA against H_2O_2-induced injury in vascular endothelial cells. The inhibition of GRP78, ATF4 and eIF2 a protein expressions in the ERS, and the subsequent alleviation of oxidative stress damage, might be the molecular mechanism.

Establishment of mixed plantations of Pinus sylvestris var.mongolica and Populus×xiaozhuanica may not be appropriate:evidence from litter decomposition

Aims Mongolian pine(Pinus sylvestris var.mongolica)and Xiaozhuan poplar(Populus×xiaozhuanica)are two predominant afforestation tree species in the semi-arid sandy lands of northeast china,which are characterized by poor soil nutrients.Plant litter decomposition plays a critical role in regulating nutrient cycling in terrestrial ecosystems.Admixture of broadleaf litter to conifer litter is expected to improve litter decomposition and soil fertility,and thus productivity.However,the effects on the decomposition of litter mixture of the above two tree species are not well understood.therefore,it is essential to assess the decomposition performance of litter mixture with the aim of improving forest nutrient management and the establishment of mixed plantation.Appropriate forest manage-ment practice is critical for the sustainability of site productivity in plantation forests.Methods We conducted a field litterbag decomposition transplant experi-ment for single pine litter,single poplar litter and their mixture in a pine stand,a poplar stand and an adjacent grassland for 16 months in the Keerqin Sandy Lands,northeast china.Important Findings After 16 months of incubation,there remained significantly more litter mass of pine(73.8%)than of poplar(67.2%).the mass remaining was positively correlated with litter carbon(c):nitrogen(N),c:phosphorus(P)and lignin:N ratios,and negatively with litter N and P concentrations,which suggests that initial litter chemical properties were an important factor affecting litter decay.Generally,net N and P immobilizations were observed during decomposition.this indicates that litter decomposition in this area was N-limited as N was progressively immobilized,and then tended to induce P limitation.thus,we strongly recommend prohibiting litter harvesting by local residents to maintain soil fertility in this nutrient-poor area.Our results do not support the home-field advantage hypothesis,as illustrated by the fact that,in most cases,mass loss of litter from native habitat was comparable to that in transplanted habitats during decomposition.Furthermore,a dominant additive effect was detected,indicating that the establishment of mixed plantation may not be appropriate for these two species.

Combined fenestrated/chimney thoracic endovascular repair for the treatment of blunt traumatic aortic injury:A case report

Blunt traumatic thoracic aortic injury(BTAI)is an extremely serious medical condition with a high rate of associated mortality.Recent advances in techniques such as thoracic endovascular repair offer new opportunities to manage the critical BTAI patients in an efficacious yet less invasive manner.A 65 year-old-male suffered from multiple injuries after a fall,including BTAI in the aortic arch,which resulted in dissection of the descending thoracic-abdominal aorta and iliac artery,development of an intimal flap in the left common carotid artery,and dissection of the left subclavian artery.Based on the imaging information of this patient and our clinical experience,the combined treatment of fenestrated thoracic endovascular repair and a chimney technique was immediately planned to fully repair these dissections and moreover prevent further dissection of the branching vessels,additionally to ensure sufficient blood flow in the left subclavian artery and left common carotid artery.The intervention yielded satisfactory early outcomes.Follow-up assessment at six months reported no symptoms or complications associated with the stent-graft.Computed tomography angiography further confirmed adequate stent-graft coverage of the aortic injury.