Impact of Supraaortic Intimal Tears on Aortic Diameter Changes After Nontotal Arch Replacement.

BACKGROUND: This study evaluated the impact of the intimal tear location on aortic dilation and reintervention after nontotal arch replacement (non-TAR) for acute type I aortic dissection. METHODS: Between 2009 and 2017, 92 patients who underwent non-TAR for acute type I aortic dissection were enrolled. Intimal tears were analyzed at the supraaortic (SA) segment; segment 1, proximal descending thoracic aorta (DTA); segment 2, distal DTA; and segment 3, abdominal aorta. Aortic diameter was measured at the pulmonary artery bifurcation, celiac axis, maximal abdominal aorta, and maximal thoracoabdominal aorta using serial follow-up computed tomographic scans. The Fisher exact or χ2 test, independent t or Mann-Whitney U test, and log-rank test were used in the statistical analyses. RESULTS: The significant factors for increasing aortic diameter were the first location of intimal tear in the SA segment and segments 1 and 2. In the adjusted analysis, the first location of intimal tear in the SA segment and segment 1 was statistically significant. In the additional adjusted analysis, a segment 1 tear without SA tear was the only significant factor for increasing aortic diameter. The 5-year freedom from reintervention rate was significantly higher in patients with no intimal tear than in those with a segment 1 intimal tear with/without SA tear. CONCLUSIONS: We confirmed that SA and proximal DTA intimal tears are associated with subsequent aortic dilation and reintervention. These proximal aortic intimal tears might warrant aggressive surgical treatment at the initial operation or close postoperative follow-up.

Dietary Patterns Associated with Sebum Content, Skin Hydration and pH, and Their Sex-Dependent Differences in Healthy Korean Adults.

Sebum content, skin hydration and acidic skin pH are major factors in maintaining skin health. Various nutrients are reported to influence skin health, but the effect of dietary patterns (DPs) on skin health is unclear. In this study, we considered the DPs associated with these three skin health parameters in 84 healthy adults aged 19⁻37 years. Dietary intake was assessed using a food frequency questionnaire (FFQ) and skin health parameters were determined on the forehead of each subject. Among the four DPs extracted from the FFQ, DP2, characterized by a high intake of cereals, potatoes and starch, saccharides and fish and shellfish, was negatively associated with skin hydration. DP3, characterized by a high intake of potatoes and starch, seeds and nuts, fruits and eggs, was positively associated with acidic skin pH only before adjusting for potential confounders. On the other hand, DP4, characterized by a low intake of beans, and a high intake of meats, dairy products and beverages and alcohol, was negatively associated with acidic skin pH and positively associated with sebum content. The data stratified by sex revealed a negative association between skin hydration and DP2 in males and a negative association between sebum content and DP3 and a positive association between sebum content and DP4 in females. In conclusion, we demonstrated that specific DPs were associated with sebum content, skin hydration and pH in healthy Korean adults and that those associations were affected by sex.

Aorta Remodeling after Endovascular Treatment of a Chronic DeBakey IIIb Aneurysm and Simultaneous Palliation of a Renal Cell Carcinoma.

We report the case of a patient with a chronic DeBakey type IIIb aneurysm who underwent thoracic endovascular aortic repair to seal the primary entry tear and stent-graft insertion to cover the re-entry tear at the renal artery. The procedure was performed in order to achieve complete thrombosis in the entire thoracoabdominal false lumen, leading to favorable aortic remodeling. Simultaneously, ethanol ablation and renal artery embolization were performed to treat a renal tumor suspicious of renal cell carcinoma. Radical nephrectomy then confirmed clear cell carcinoma. To the best of our knowledge, no other cases of this type have been reported in the Korean literature.

Diffusion-weighted magnetic resonance imaging lesions after repair of acute type A aortic dissection: association with neurocognitive outcomes†‡.

OBJECTIVES: We sought to analyse the preoperative status of arch vessels by postoperative diffusion-weighted magnetic resonance imaging (DWI) as a potential surrogate marker for cerebral thromboembolism and its relationship to neurocognitive outcomes. METHODS: Preoperative computed tomography (CT) and postoperative DWI were available for 50 patients who received surgery for acute type A aortic dissection. Two radiologists evaluated CT and DWI scans. Mini-mental status examinations (MMSE) were performed on the same day with DWI. RESULTS: Mean age of participants was 57 ± 14 years. MMSE and DWI were performed 6 ± 3 days after surgery. New cerebral embolisms were evident in 35 of 50 patients (70%) and often occurred as multiple lesions (28/35, 80%; range 2-21). Among patients with multiple lesions, 23 (66%) were clinically silent. Pathological lesions at the origin of the arch vessels correlated with the number and volume of new DWI lesions (P < 0.05). Degree of neurocognitive dysfunction tested by MMSE was negatively associated with age (r = -0.48, P < 0.0001) and left-sided DWI lesion number and volume (r = -0.74, P < 0.0001; r = -0.707, P < 0.0001). CONCLUSIONS: DWI revealed new cerebral embolisms in 70% of patients following surgery for acute type A aortic dissection. Lesion number and volume significantly correlated with pathological status of arch vessels. MMSE was representative of left-sided lesions.

Prognostic factors for aorta remodeling after thoracic endovascular aortic repair of complicated chronic DeBakey IIIb aneurysms.

OBJECTIVES: The use of thoracic endovascular aortic repair (TEVAR) for chronic DeBakey III type b (CDIIIb) aneurysms is controversial. We analyzed the potential prognostic factors affecting aorta remodeling after this procedure. METHODS: A total of 20 patients with CDIIIb aneurysms underwent TEVAR, with full coverage of reentry tears at the descending thoracic aorta. The potential factors affecting false lumen (FL) remodeling were analyzed, including reentry tears (communicating channels visible on the computed tomography angiogram), large intimal tears below the stent graft (≥ 2 consecutive axial cuts on the computed tomography angiogram), visceral branches arising from the FL, and intercostal arteries (ICAs) arising from the FL. RESULTS: All the patients had uneventful in-hospital courses; 2 patients (10%) required reintervention during the follow-up period. Thirteen patients (65%) had complete thrombosis of the FL at stent graft segment. Compared with the complete thrombosis group, the partial thrombosis group had more reentry tears (1.8 vs 2.3, P = .48), large intimal tears (0.8 vs 1.7, P < .05), visceral branches arising from the FL (1.2 vs 2.3, P < .05), and ICAs arising from the FL (3.8 vs 5.1, P = .35). Reentry tears, visceral branches, and ICAs from the FL were significant negative prognostic factors for FL shrinkage (P < .05). CONCLUSIONS: Although reentry tears above the celiac trunk were fully covered, the visceral branches and ICAs from the FL and all communicating channels below the celiac trunk kept the FL pressurized and were unfavorable prognostic factors for aorta remodeling after TEVAR for CDIIIb aneurysms.

Wafer-scale nanowell array patterning based electrochemical impedimetric immunosensor.

We have reported that nanowell array (NWA) can enhance electrochemical detection of molecular binding events by controlling the binding sites of the captured molecules. Using NWA biosensor based amperometric analysis, we have detected biological macromolecules such as DNA, protein or aptamers at low concentrations. In this research, we developed an impedimetric immunosensor based on wafer-scale NWA for electrochemical detection of stress-induced-phosphoprotein-1 (STIP-1). In order to develop NWA sensor through the cost-effective combination of high-throughput nanopattern, the NWA electrode was fabricated on Si wafer by krypton-fluoride (KrF) stepper semiconductor process. Finally, 12,500,000 ea nanowell with a 500 nm diameter was fabricated on 4 mm × 2 mm substrate. Next, by using these electrodes, we measured impedance to quantify antigen binding to the immunoaffinity layer. The limit of detection (LOD) of the NWA was improved about 100-fold compared to milli-sized electrodes (4 mm × 2 mm) without an NWA. These results suggest that wafer-scale NWA immunosensor will be useful for biosensing applications because their interface response is appropriate for detecting molecular binding events.

Effects of intermittent lower body perfusion on end-organ function during repair of acute DeBakey type I aortic dissection under moderate hypothermic circulatory arrest.

OBJECTIVES: To avoid deep hypothermia-related side effects, moderate hypothermic circulatory arrest (HCA) is commonly employed during aortic arch repair, thereby jeopardizing end-organ protection. We sought to analyse the effect of intermittent lower body perfusion (ILBP) on end-organ function during repair of acute DeBakey type I aortic dissection (AIAD). METHODS: Between May 2008 and May 2011, 107 patients underwent surgical repair for AIAD. All operations were performed with selective cerebral perfusion (SCP) under either moderate HCA only (n = 57) or moderate HCA with ILBP (n = 50). Adverse outcomes, including operative mortality, permanent neurological deficit, temporary neurological deficit, renal failure requiring dialysis and hepatic dysfunction, were compared between the two groups. RESULTS: The mean body temperature at the initiation of SCP was 28.7 ± 1.9 °C. Overall operative mortality occurred in 6 (5.6%) patients. The incidences of permanent neurological deficit and temporary neurological deficit were 1.9 and 4.7%, respectively. None of the 9 (8.4%) patients who suffered postoperative renal failure requiring dialysis received ILBP. The laboratory data showed significantly lower levels of hepatic and kidney enzymes in the ILBP group (P < 0.05). CONCLUSIONS: Significantly lower levels of hepatic and kidney enzymes indicate more effective end-organ protection with the use of ILBP. Our data suggest that ILBP provides more effective end-organ protection during repair of aortic arch under moderate HCA.

Total Arch Replacement with Stented Elephant Trunk in DeBakey Type I Acute Aortic Dissection.

A 67-year-old female patient was treated with conventional total arch replacement and insertion of a stented elephant trunk (SET) graft into the descending thoracic aorta for acute DeBakey type I aortic dissection at one time. She had been treated with right coronary artery stent insertion for acute myocardial infarct 4 days earlier, and at that time, she was diagnosed with acute DeBakey type I aortic dissection from the ascending aorta to the suprarenal artery based on trans-esophageal echocardiography and aorta computed tomography. Through a median sternotomy, we inserted the SET graft through the opened aorta to the descending aorta. We also performed anastomosis between the proximal stented graft and the distal aortic arch, and then performed total arch replacement. For acute DeBakey type I aortic dissection, we report total arch replacement with insertion of a SET graft as a combination of conventional surgery and the interventional technique.

Supramolecular switching between flat sheets and helical tubules triggered by coordination interaction.

Here we report the spontaneous formation of switchable sheets in aqueous solution, which is based on bent-shaped aromatic amphiphiles containing m-pyridine units at the terminals and a hydrophilic dendron at the apex. The aromatic segments self-assemble into flat sheets consisting of a zigzag conformation through π-π stacking interactions. Notably, the sheets reversibly transform into helical tubules at higher concentration and into discrete dimeric macrocycles at a lower concentration in response to Ag(I) ions through reversible coordination interactions between the pyridine units of the aromatic segments and the Ag(I) ions. While maintaining the coordination bonding interactions, the helical tubules reversibly transform into the dimeric macrocycles in response to the variation in concentration.

Directional assembly of α-helical peptides induced by cyclization.

Effective stabilization of short peptide chains into a helical structure has been a challenge in the fields of chemistry and biology. Here we report a novel method for α-helix stabilization of short peptides through their confinement in a cyclic architecture. We synthesized block peptides based on a short peptide and a flexible linker as linear precursors. Subsequent cyclization of the peptide precursors resulted in a conformational change of the peptide unit from a random coil to an α-helix. The incorporation of hydrophobic residues into the peptide unit led to a facially amphiphilic conformation of the molecular cycle. The resulting amphiphilic peptide self-assembled into undulated nanofibers through the directional assembly of small oblate micelles.

Activation of fractalkine/CX3CR1 by vascular endothelial cells induces angiogenesis through VEGF-A/KDR and reverses hindlimb ischaemia.

AIMS: The present study investigated the detailed mechanism by which fractalkine (Fkn), a CX3C chemokine, induces angiogenesis and its functional implication in alleviating ischaemia in vivo. METHODS AND RESULTS: Fkn induced new vessel formation on the excised rat aorta and chick chorioallantoic membrane (CAM) through CX3CR1 activation. Immunoblotting analysis, promoter assay and electrophoretic mobility shift assay showed that Fkn upregulated hypoxia-inducible factor-1 alpha (HIF-1alpha) by cultured human aortic endothelial cells (ECs), which in turn induced mRNA and protein levels of vascular endothelial growth factor (VEGF)-A through a p42/44 mitogen-activated protein kinase pathway. In vivo Fkn-induced angiogenesis on CAM was completely blocked by functional inhibition of VEGF receptor 2 kinase insert domain-containing receptor (KDR) and Rho GTPase. C57/BL6 mice with CX3CR1(-/-) bone marrow-derived cells developed angiogenesis in the implanted Fkn-mixed Matrigel plug, suggesting CX3CR1 activation in vascular ECs is sufficient for Fkn-induced angiogenesis in vivo. The condition of rat hindlimb ischaemia, which rapidly stimulated mRNA expression of both Fkn and VEGF-A, was significantly alleviated by the injection of whole-length Fkn protein. CONCLUSION: Fkn-induced activation of CX3CR1 by ECs leads to in vivo angiogenesis through two sequential steps: the induction of HIF-1alpha and VEGF-A gene expression by CX3CR1 activation and the subsequent VEGF-A/KDR-induced angiogenesis. The potent induction of angiogenesis by Fkn can be used as a therapeutic strategy for alleviating peripheral ischaemia.

The effect of cholesterol in the liposome bilayer on the stabilization of incorporated Retinol.

The effect of cholesterol in the liposome bilayer on the stability of incorporated retinol was studied. Retinol was incorporated into liposomes containing soybean phosphatidylcholine (PC) and cholesterol (CH) at various ratios, and the liposomes were prepared as multilamellar vesicles by the dehydration-rehydration method. Retinol readily incorporated into liposomes at a ratio of 0.01:1 (w/w) retinol:lipid, with over 94.52% being incorporated in all conditions studied. The incorporation efficiency of retinol increased slightly with increasing CH content in the liposome and with increasing pH of the hydration buffer. Average particle size increased as the CH content increased, and mean particle sizes at pH 5, 7, and 9 were 30.27, 89.53, and 41.42 microm, respectively. The time course of retinol degradation in aqueous solution in liposomes with various ratios of PC to CH was determined under a variety of pH conditions (pH 5, 7, and 9), and temperatures (4, 25, 37, and 50 degrees C). The stability of incorporated retinol was enhanced by increasing the CH content. At pH 7.0 and 4 degrees C, for example, 90.17% of the retinol in liposomes containing 50:50 (PC:CH) remained after 10 days of storage, whereas 51.46% remained at 100:0 (PC:CH). These results indicate that CH in liposomes greatly increases the incorporation efficiency of retinol and the stability of incorporated retinol.