Synthesis of 2-(Pyridin-2-yl)phenols and 2-(Pyridin-2-yl)anilines

Herein, we report a new synthetic strategy for 2-(pyridin-2-yl)phenols and 2-(pyridin-2-yl)anilines catalyzed by a Pd/C-ethylene system. The starting materials, 2-(pyridin-2-yl)cyclohexan-1-ones, can be easily prepared by the reaction of substituted pyridine N-oxide and cyclohexanones. The most useful feature of this method is that both 2-(pyridin-2-yl)phenols and 2-(pyridin-2-yl)anilines are easily synthesized independently using the same compound as a starting material, simply by adding or not adding a nitrogen source.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Sensitizer-Free Photochemical Regeneration of Benzimidazoline Organohydride

Organohydrides are an important class of organic compounds that can provide hydride anions for chemical and biochemical reactions, as demonstrated by reduced nicotinamide adenine dinucleotides serving as important natural redox cofactors. The coupling of hydride transfer from the organohydride to the substrate and subsequent regeneration of the organohydride from its oxidized form can realize organohydride-catalyzed reduction reactions. Depending on the structure of the organohydride, its hydridicity and ease of regeneration vary. Benzimidazoline (BIH) is one of the strongest synthetic C-H hydride donors; however, its reductive regeneration requires highly reducing conditions. In this study, we synthesized various oxidized and reduced forms of BIH derivatives with aryl groups at the 2-position and investigated their photophysical and electrochemical properties. 4-(Dimethylamino)phenyl-substituted BIH exhibited salient red-shifted absorption compared with other synthesized BIH derivatives, and visible-light-driven regeneration without using an external photosensitizer was achieved. This knowledge has significant implications for the future development of solar-energy-based catalytic photoreduction technologies that utilize organohydride regeneration strategies.

Dithiothreitol-Measured Oxidative Potential of Reference Materials of Mineral Dust: Implications for the Toxicity of Mineral Dust Aerosols in the Atmosphere

Oxidative stress is a mechanism that might raise the toxicity of mineral dust aerosols. We evaluated the oxidative potential (OP) of four reference materials (RMs) of mineral dusts using dithiothreitol assay. The OP of the water-soluble fraction of the dust RMs accounts for 40%-70% of the OP of the total fraction. The values of total and water-soluble OP normalized by the surface area of insoluble particles showed agreement among the different dust RMs. The surface area of insoluble dust particles was therefore inferred as an important factor affecting the OP of mineral dust. Using the relation between total OP and the surface area of insoluble particles of the dust RMs, we estimated the total OPs of fine and coarse atmospheric mineral dust aerosols assuming a typical particle size distribution of Asian dust aerosols observed in Japan. Mass-normalized total OPs were estimated at 44 and 23 pmol min^-1 μg^-1 for fine and coarse atmospheric mineral dust particles. They closely approximate the values observed for urban aerosols in Japan, which suggests that mineral dust plume advection can lead to a marked increase in human exposure to redox-active aerosols, even far downwind from mineral dust source regions.

Assessing oxidative stress induction ability and oxidative potential of PM2.5 in cities in eastern and western Japan

Oxidative stress is an important cause of respiratory diseases associated with exposure to PM_2.5. Accordingly, acellular methods for assessing the oxidative potential (OP) of PM_2.5 have been evaluated extensively for use as indicators of oxidative stress in living organisms. However, OP-based assessments only reflect the physicochemical properties of particles and do not consider particle-cell interactions. Therefore, to determine the potency of OP under various PM_2.5 scenarios, oxidative stress induction ability (OSIA) assessments were performed using a cell-based method, the heme oxygenase-1 (HO-1) assay, and the findings were compared with OP measurements obtained using an acellular method, the dithiothreitol assay. For these assays, PM_2.5 filter samples were collected in two cities in Japan. To quantitatively determine the relative contribution of the quantity of metals and subtypes of organic aerosols (OA) in PM_2.5 to the OSIA and the OP, online measurements and offline chemical analysis were also performed. The findings showed a positive relationship between the OSIA and OP for water-extracted samples, confirming that the OP is generally well suited for use as an indicator of the OSIA. However, the correspondence between the two assays differed for samples with a high water-soluble (WS)-Pb content, which had a higher OSIA than would be expected from the OP of other samples. The results of reagent-solution experiments showed that the WS-Pb induced the OSIA, but not the OP, in 15-min reactions, suggesting a reason for the inconsistent relationship between the two assays across samples. Multiple linear regression analyses and reagent-solution experiments showed that WS transition metals and biomass burning OA accounted for approximately 30-40% and 50% of the total OSIA or the total OP of water-extracted PM_2.5 samples, respectively. This is the first study to evaluate the association between cellular oxidative stress assessed by the HO-1 assay and the different subtypes of OA.

Direct imaging and astrometric detection of a gas giant planet orbiting an accelerating star

Direct imaging of gas giant exoplanets provides information on their atmospheres and the architectures of planetary systems. However, few planets have been detected in blind surveys with direct imaging. Using astrometry from the Gaia and Hipparcos spacecraft, we identified dynamical evidence for a gas giant planet around the nearby star HIP 99770. We confirmed the detection of this planet with direct imaging using the Subaru Coronagraphic Extreme Adaptive Optics instrument. The planet, HIP 99770 b, orbits 17 astronomical units from its host star, receiving an amount of light similar to that reaching Jupiter. Its dynamical mass is 13.9 to 16.1 Jupiter masses. The planet-to-star mass ratio [(7 to 8) × 10^-3] is similar to that of other directly imaged planets. The planet's atmospheric spectrum indicates an older, less cloudy analog of the previously imaged exoplanets around HR 8799.

One-Pot Synthesis of 3-Substiuted Indoles from 2-(2-Nitro-1-phenylethyl)cyclohexanone Derivatives

Herein, a one-pot synthesis of 3-substituted indoles from 2-(2-nitro-1-phenylethyl)cyclohexanone derivatives catalyzed by Pd/C is reported. The starting materials can be easily prepared by the reaction of substituted ketones and nitroalkenes. The facile experimental procedure comprises the treatment of 2-(2-nitro-1-phenylethyl)cyclohexanone derivatives with H₂ as a hydrogen donor in the presence of 10 mol % Pd/C. Subsequently, the exchange of H₂ with CH₂═CH₂ as a hydrogen acceptor affords a variety of 3-substituted indoles in high yields. The formation of intermediate nitrones is essential for a smooth reaction.

Metal-free reduction of CO2 to formate using a photochemical organohydride-catalyst recycling strategy

Increasing levels of CO₂ in the atmosphere is a problem that must be urgently resolved if the rise in current global temperatures is to be slowed. Chemically reducing CO₂ into compounds that are useful as energy sources and carbon-based materials could be helpful in this regard. However, for the CO₂ reduction reaction (CO₂RR) to be operational on a global scale, the catalyst system must: use only renewable energy, be built from abundantly available elements and not require high-energy reactants. Although light is an attractive renewable energy source, most existing CO₂RR methods use electricity and many of the catalysts used are based on rare heavy metals. Here we present a transition-metal-free catalyst system that uses an organohydride catalyst based on benzimidazoline for the CO₂RR that can be regenerated using a carbazole photosensitizer and visible light. The system is capable of producing formate with a turnover number exceeding 8,000 and generates no other reduced products (such as H₂ and CO).

Development of Rat Caries-Induced Pulpitis Model for Vital Pulp Therapy

Rodent animal models for vital pulp therapy are commonly used in dental research because their tooth anatomy and cellular processes are similar to the anatomy and processes in humans. However, most studies have been conducted using uninfected sound teeth, which makes it difficult to adequately assess the inflammatory shift after vital pulp therapy. In the present study, we aimed to establish a caries-induced pulpitis model based on the conventional rat caries model and then evaluate inflammatory changes during the wound-healing process after pulp capping in a model of reversible pulpitis induced by carious infection. To establish the caries-induced pulpitis model, the pulpal inflammatory status was investigated at different stages of caries progression by immunostaining targeted to specific inflammatory biomarkers. Immunohistochemical staining revealed that both Toll-like receptor 2 and proliferating cell nuclear antigen were expressed in moderate and severe caries-stimulated pulp, indicating that an immune reaction occurred at both stages of caries progression. M2 macrophages were predominant in moderate caries-stimulated pulp, whereas M1 macrophages were predominant in the severe caries-stimulated pulp. Pulp capping in teeth with moderate caries (i.e., teeth with reversible pulpitis) led to complete tertiary dentin formation within 28 d after treatment. Impaired wound healing was observed in teeth with severe caries (i.e., teeth with irreversible pulpitis). During the wound-healing process in reversible pulpitis after pulp capping, M2 macrophages were predominant at all time points; their proliferative capacity was upregulated in the early stage of wound healing compared with healthy pulp. In conclusion, we successfully established a caries-induced pulpitis model for studies of vital pulp therapy. M2 macrophages have an important role in the early stages of the wound-healing process in reversible pulpitis.

Origin of surface water in the Southern Ocean: Implications of soluble radionuclide distributions

Concentration data of soluble radionuclides in the southern South Indian Ocean and Southern Ocean transition zone are rare or insufficient for the study of its current system. We examined the lateral surface variations in soluble natural (²²⁶Ra and ²²⁸Ra) and anthropogenic (¹³⁴Cs and ¹³⁷Cs) radionuclide activity concentrations in the surface waters in this area from November 2021 to March 2022. The surface distributions of ²²⁶Ra and ¹³⁷Cs concentrations were classified into Subantarctic Mode Water-, Antarctic Intermediate Water-, and Upper Circumpolar Deep Water (UCDW)-dominated areas along latitudinal band (40°S-65°S, 110°E-120°E). Notably, the highest ²²⁶Ra concentrations occurred along the longitudinal band (60°S-65°S, 40°E-120°E). Significantly lower ¹³⁷Cs concentrations in the Southern Ocean than those in surface waters in other global oceans were observed along with depletion of ²²⁸Ra. Additionally, ²²⁶Ra and ¹³⁷Cs concentrations appeared to show small variations between eastern and western areas (2.5-3.0 mBq/L and 0.06-0.03 mBq/L, respectively). Lateral profiles in the Southern Ocean are governed by a large contribution from deep/old waters (e.g., UCDW), with a small effect from southward transport of Subantarctic Mode Water.

Novel Functional Peptide for Next-Generation Vital Pulp Therapy

Although vital pulp therapy should be performed by promoting the wound-healing capacity of dental pulp, existing pulp-capping materials were not developed with a focus on the pulpal repair process. In previous investigations of wound healing in dental pulp, we found that organic dentin matrix components (DMCs) were degraded by matrix metalloproteinase-20, and DMC degradation products containing protein S100A7 (S100A7) and protein S100A8 (S100A8) promoted the pulpal wound-healing process. However, the direct use of recombinant proteins as pulp-capping materials may cause clinical problems or lead to high medical costs. Thus, we hypothesized that functional peptides derived from recombinant proteins could solve the problems associated with direct use of such proteins. In this study, we identified functional peptides derived from the protein S100 family and investigated their effects on dental pulp tissue. We first performed amino acid sequence alignments of protein S100 family members from several mammalian sources, then identified candidate peptides. Next, we used a peptide array method that involved human dental pulp stem cells (hDPSCs) to evaluate the mineralization-inducing ability of each peptide. Our results supported the selection of 4 candidate functional peptides derived from proteins S100A8 and S100A9. Direct pulp-capping experiments in a rat model demonstrated that 1 S100A8-derived peptide induced greater tertiary dentin formation compared with the other peptides. To investigate the mechanism underlying this induction effect, we performed liquid chromatography-tandem mass spectrometry analysis using hDPSCs and the S100A8-derived peptide; the results suggested that this peptide promotes tertiary dentin formation by inhibiting inflammatory responses. In addition, this peptide was located in a hairpin region on the surface of S100A8 and could function by direct interaction with other molecules. In summary, this study demonstrated that a S100A8-derived functional peptide promoted wound healing in dental pulp; our findings provide insights for the development of next-generation biological vital pulp therapies.

The role of cellular senescence in aortic dissection

Background

Aortic dissection (AD) is a catastrophic disease that occurs suddenly. The acute mortality is high and those who survived frequently suffer from serious complications such as aneurysm formation and distal ischemia due to progressive destruction of the aortic walls. Currently, no predictor of AD onset is available nor therapeutic intervention to specifically prevent the progressive destruction in AD, because the molecular pathogenesis is largely unknown. Clinical and experimental studies highlighted the importance of inflammation in AD, although the regulatory mechanism of inflammation remains unclear. Recently, we found that cell proliferation precedes the inflammatory response in AD. Because cell proliferation causes cellular senescence that can induce inflammatory response, we hypothesized that cellular senescence participates in AD pathogenesis.

Objective

We investigated if cellular senescence contributes to AD development and progression in mouse AD model.

Methods and results

A mouse AD model was created by continuous infusion of beta-aminopropionitrile and angiotensin II (BAPN+AngII), where AD starts to develop in 3 days and occurs to most of the mice in 14 days accompanied by frequent AD rupture and death. Infusion of BAPN+AngII resulted in the induction of senescence markers Ink4a from day 3 before AD onset and persisted for the 14 days of the observational period.

Cellular senescence, as demonstrated by the expression of senescence-associated beta-galactosidase, was evident in intimal endothelial cells, medial smooth muscle cells, adventitial macrophages and fibroblasts. We examined the role of cellular senescence in AD pathogenesis by oral administration of ABT263 which is known as “senolytics” that eliminates senescent cells. ABT263 treatment reduced the expression of the senescence marker, prevented the death by AD rupture, and ameliorated the severity of AD lesion compared to the vehicle treatment. Transcriptome analysis revealed that ABT treatment suppressed the immune and inflammatory response in AD. Quantitative RT-PCR confirmed that ABT treatment prevented the induction of p21Cip1, interleukin-6, several chemokines and their receptors by 3-day infusion of BAPN+AngII.

Conclusions

These findings demonstrated that senescence of multiple cell types precedes AD development, which is likely to induce the inflammatory response. Elimination of senescent cells effectively prevented AD progression and death. Therefore, cellular senescence represents a potential predictor and a therapeutic target for AD.

Funding Acknowledgement

Type of funding sources: None.

M. avium complex pulmonary disease: does the diagnostic method affect severity and progression?

SETTING: Diagnosis of Mycobacterium avium complex pulmonary disease (MAC-PD) requires positive culture of expectorated sputum or specimens acquired by bronchoscopy. Whether patients diagnosed using bronchoscopy have milder disease and milder progression than those diagnosed using sputum remains uncertain.OBJECTIVE: To clarify whether disease severity and progression differ according to the diagnostic method.METHODS: We retrospectively analysed 92 patients with MAC-PD. We compared characteristics of patients and disease progression according to the diagnostic methods used: sputum or bronchoscopy. Additionally, we investigated the impact of these methods on disease progression using multivariate analysis.RESULTS: Patients diagnosed using sputum were younger than those diagnosed using bronchoscopy; however, there were small differences from the viewpoint of clinical practice in disease severity, and estimated progression-free survival rate did not differ significantly. The predictors of disease progression were disease forms other than non-cavitary nodular/bronchiectatic disease, hypoalbuminemia and severe radiographic scores.CONCLUSION: The diagnostic methods had no significant impact on disease severity and disease progression of MAC-PD. If the diagnosis cannot be established by sputum culture or if sputum cannot be obtained in the patients with risk factors for disease progression, bronchoscopy would be useful to provide opportunity of treatment for MAC-PD.

Furoxan Incorporation into C-H Bonds Enabling Nitrogen-Containing Functional Group Installation into the Same

A C-C bond forming method was developed, whereby a furoxan ring is incorporated into various types of C-H bonds. The protocol not only offers a concise synthetic route to a variety of alkylated furoxan derivatives but also provides an efficient strategy for the insertion of various nitrogen-containing functional groups into C-H bonds via transformation of the resultant furoxan ring.

The role of cellular senescence in aortic dissection

Background

Aortic dissection (AD) is a catastrophic disease that occurs suddenly. The acute mortality is high and those who survived frequently suffer from serious complications such as aneurysm formation and distal ischemia due to progressive destruction of the aortic walls. Currently, no reliable predictor is available for AD development and surgical intervention is the only therapeutic option to prevent the fatal events after AD development, because the pathogenesis of AD is largely unknown.

Clinical and experimental studies highlighted the importance of inflammation in AD pathogenesis, although the trigger of inflammation remains unclear. Recently, we found that cell proliferation precedes the inflammatory response in AD. Because cell proliferation triggers cellular senescence and senescent cells secrete of proinflammatory cytokines and matrix metalloproteinases, we hypothesized that cellular senescence may participate in AD pathogenesis.

Objective

We investigated if cellular senescence contributes to AD development and progression in a mouse model of AD.

Methods and results

A mouse AD model was created by continuous infusion of beta-aminopropionitrile and angiotensin II (BAPN+AngII), where AD starts to develop in 3 days and occurs to most of the mice in 14 days accompanied by frequent AD rupture and death. Infusion of BAPN+AngII resulted in the appearance of senescent cells that are positive for senescence-associated beta-galactosidase, and expression of senescence markers Arf and Ink4a in the aortic walls. Appearance of cellular senescence occurred in one day of BAPN+AngII infusion and continued throughout the observational period of 14 days. We examined the role of cellular senescence in AD pathogenesis by oral administration of ABT263 which is known as “senolytics” that eliminates senescent cells. ABT263 treatment reduced the expression of the senescence markers. In the vehicle-treated group, the mortality was 66.7% (12/18), whereas that of ABT263-treated group was 35% (14/20, P&lt;0.05 by log-rank test). The severity of AD, as assessed by the lesion length in vehicle group was33.2±3.1 mm, whereas that in ABT263 group was 24.6±1.8 mm (P&lt;0.05).

Conclusions

These findings demonstrated that cellular senescence precedes AD development, and ABT263 effectively prevented AD progression and death, indicating the involvement of cellular senescence in AD pathogenesis. Therefore, cellular senescence represents a potential predictor and a therapeutic target for AD.

Funding Acknowledgement

Type of funding sources: None.

Involvement of FAK in aortic dissection: potential role in aortic interstitial cells

Background

Aortic dissection (AD) is a fatal disease where the intimomedial layer of the aorta suddenly fail. Although it is widely accepted that hemodynamic stress on the aortic wall triggers its destruction that is further promoted by inflammatory response as exemplified by the infiltration of neutrophils and macrophages, molecular mechanism is unknown for the link of aortic wall stress, inflammation and tissue destruction. In general, mechanical stress to the tissue is converted to the cellular response through the cell adhesion molecules and the activation of focal adhesion kinase (Fak). Although it has been reported that Fak is involved in pathogenesis of aortic aneurysm by promoting migration and activation of macrophages, its role in AD is unknown. We hypothesized that Fak may be involved in AD pathogenesis.

Purpose

We investigated the involvement of Fak in AD pathogenesis, focusing on its role in inflammatory cells.

Methods and results

We created a mouse model of AD by continuous infusion of beta-aminopropionitrile, a collagen crosslink inhibitor, and angiotensin II (BAPN + Ang II). Immunostaining for activated Fak revealed that Fak was not activated in normal aorta, but was activated in the infiltrating inflammatory cells and in interstitial cells of the aortic wall after AD development. We examined the role of Fak by oral administration of PND-1186, a specific Fak inhibitor, in mouse AD model. Vehicle-treated group showed 63.6% mortality, whereas PND-1186-treated group showed 20% mortality (P&lt;0.01, n=20 for each group) in 14 days of the observational period. The aortic arch lesion, the most critical part in AD, was improved from 1.96±0.41 mm in vehicle group to 0.66±0.29 mm in PND group (P&lt;0.05). We next examined the cell type-specific role of Fak in AD by creating macrophage and granulocyte-specific deletion of Fak driven by LysM-Cre and floxed Fak system. Unexpectedly, the genetic deletion of Fak in macrophages and granulocytes had no impact on the mortality nor the severity of AD.

Conclusions

These findings proved that Fak plays a critical role in AD progression and death. Because Fak is dispensable for macrophages and granulocytes, other cell types, possibly aortic wall interstitial cells, may be regulated by Fak in AD pathogenesis. Deciphering the role of Fak would provide the fundamental understanding of AD pathogenesis.

Funding Acknowledgement

Type of funding sources: None.

Borylfuroxans: Synthesis and Applications

Herein we report the first synthesis of borylfuroxans via the reaction of sulfonylfuroxans with Lewis base-ligated boranes under radical conditions. As a synthetic application, the transformation of borylfuroxans to a range of 1,2-dioximes and their derivatives is demonstrated.

Fabrication of Vascularized DPSC Constructs for Efficient Pulp Regeneration

Dental pulp regeneration is a promising approach to restore the vitality of necrotic teeth. We have previously reported the fabrication of scaffold-free cell constructs containing only dental pulp stem cells (DPSCs) and their ability to form pulp-like tissue in the pulpless tooth. However, the DPSC construct could not build pulp-like tissue with a full root length because it is difficult to induce blood vessels from a small root canal foramen. Therefore, we hypothesized that vascular structure could be preformed in the DPSC construct by employing endothelial differentiation capability of DPSCs, and vascularized constructs might facilitate dental pulp regeneration in the pulpless tooth. In this study, vascularized DPSC constructs were fabricated by inducing endothelial differentiation, and then we investigated the behavior of differentiated DPSCs, the internal structure of cell constructs, and their pulp regenerative ability in vivo. We observed that DPSCs positive for CD31 and von Willebrand factor were localized at the outer layer of constructs and formed a reticulated lumen structure. The cells constituting the outer layer of the construct expressed endothelial differentiation markers at higher levels than cells in the inner part. These results indicated that DPSCs in the outer layer differentiated into endothelial cells and formed vascular-like structures in the cell construct. Next, a vascularized DPSC construct was transplanted into the human pulpless tooth that was implanted into immunodeficient mice in the subcutaneous space. After 6 wk of implantation, the vascularized construct formed pulp-like tissues with higher density of human CD31-positive blood vessels when compared with specimens implanted with a DPSC construct without prevascularization. These results suggest that the vascular structure formed in the DPSC construct facilitated the blood supply and enhanced pulp regeneration. This study demonstrates that a vascularized DPSC construct is a prospective biomaterial as an implant for novel dental pulp regeneration.

Regiodivergent Desymmetrization Reaction of meso-Azabicycloheptene Providing Two Enantioenriched Structural Isomers

A novel catalytic asymmetric reaction is reported where the regiodivergent desymmetrisation of meso-azabicycloheptene via allylic oxidation using a single chiral copper catalyst produced two different, enantioenriched structural isomers in high optical purity starting from a single compound. The enantioselectivity of the two structurally isomeric compounds was enriched to >99.5% ee after derivatization.

Synthesis of Substituted Anilines from Cyclohexanones Using Pd/C-Ethylene System and Its Application to Indole Synthesis

The synthesis of anilines and indoles from cyclohexanones using a Pd/C-ethylene system is reported. A simple combination of NH₄OAc and K₂CO₃ under nonaerobic conditions was found to be the most suitable to perform this reaction. Hydrogen transfer between cyclohexanone and ethylene generates the desired products. The reaction tolerates a variety of substitutions on the starting cyclohexanones.

Effects of ambient particulate matter on a reconstructed human corneal epithelium model

We evaluated the effects of ambient particulate matter (PM) on the corneal epithelium using a reconstructed human corneal epithelium (HCE) model. We collected two PM size fractions [aerodynamic diameter smaller than 2.4 µm: PM_0.3–2.4 and larger than 2.4 µm: PM_>2.4] and exposed these tissues to PM concentrations of 1, 10, and 100 µg/mL for 24 h. After exposure, cell viability and interleukin (IL) IL-6 and IL-8 levels were determined, and haematoxylin and eosin and immunofluorescence staining of the zonula occludens-1 (ZO-1) were performed on tissue sections. In addition, the effects of a certified reference material of urban aerosols (UA; 100 µg/mL) were also examined as a reference. The viability of cells exposed to 100 μg/mL UA and PM_>2.4 decreased to 76.2% ± 7.4 and 75.4% ± 16.1, respectively, whereas PM_0.3–2.4 exposure had a limited effect on cell viability. These particles did not increase IL-6 and IL-8 levels significantly even though cell viability was decreased in 100 μg/mL UA and PM_>2.4. ZO-1 expression was reduced in a dose-dependent manner in all groups. Reconstructed HCE could be used as an in vitro model to study the effects of environmental PM exposure on ocular surface cell viability and inflammation.

Photocatalytic Reductive C-O Bond Cleavage of Alkyl Aryl Ethers by Using Carbazole Catalysts with Cesium Carbonate

Methods to activate the relatively stable ether C-O bonds and convert them to other functional groups are desirable. One-electron reduction of ethers is a potentially promising route to cleave the C-O bond. However, owing to the highly negative redox potential of alkyl aryl ethers (E^red < -2.6 V vs SCE), this mode of ether C-O bond activation is challenging. Herein, we report the visible-light-induced photocatalytic cleavage of the alkyl aryl ether C-O bond using a carbazole-based organic photocatalyst (PC). Both benzylic and non-benzylic aryl ethers underwent C-O bond cleavage to form the corresponding phenol products. Addition of Cs₂CO₃ was beneficial, especially in reactions using a N-H carbazole PC. The reaction was proposed to occur via single-electron transfer (SET) from the excited-state carbazole to the substrate ether. Interaction of the N-H carbazole PC with Cs₂CO₃ via hydrogen bonding exists, which enables a deprotonation-assisted electron-transfer mechanism to operate. In addition, the Lewis acidic Cs cation interacts with the substrate alkyl aryl ether to activate it as an electron acceptor. The high reducing ability of the carbazole combined with the beneficial effects of Cs₂CO₃ made this otherwise formidable SET event possible.

Impact of tapered-shaped left ventricular outflow tract on permanent pacemaker implantation after the third-generation balloon-expandable valve implantation

Background

In the era of transcatheter aortic valve implantation (TAVI) for patients with lower surgical risk, conduction disturbances requiring permanent pacemaker implantation (PPI) after TAVI remain a serious concern. The association between tapered-shaped left ventricular outflow tract (LVOT) and PPI after TAVI has not been elucidated.

Purposes

This study sought to identify predictors for PPI after TAVI with the third-generation balloon-expandable valve, with focus on LVOT morphology.

Methods

Of 272 consecutive patients treated with the third-generation balloon-expandable valve, 256 patients without previous PPI or bicuspid valve were retrospectively analyzed.

Results

PPI was implanted after TAVI in 20 (7.8%) patients. Patients requiring PPI had smaller LVOT area (356.3 mm2 vs. 399.4 mm2, p=0.011). Moreover, receiver-operating characteristic (ROC) statistics showed that LVOT area /annulus area possessed significantly higher predictive ability than LVOT area (area under the curve: 0.91 [95% confidence interval [CI]: 0.84 to 0.95] vs. 0.67 [95% CI: 0.57 to 0.77], p&lt;0.001). Multivariable analysis revealed LVOT area /annulus area (odds ratio [OR]: 1.93 [95% CI: 1.38–2.71]; p&lt;0.001 per % of decreasing), the difference between membranous septum length and implantation depth (ΔMSID) (OR: 6.82 [95% CI 2.39–19.48]; p&lt;0.001 per mm of decreasing) and pre-existing complete right bundle branch block (CRBBB) (OR: 32.38 [95% CI 2.30–455.63]; p=0.002) as independent predictors of PPI. Further analysis using ROC statistics revealed LVOT area / annulus area of 88.5% and ΔMSID of 1.8 mm as the optimal cutoff points for prediction of PPI after the third-generation balloon-expandable valve implantation, with high negative predictive values of 98.1% and 99.0%, respectively. Figure shows the PPI rates stratified by the number of following predictors: LVOT area /annulus area &lt;88.5%, ΔMSID &lt;1.8 mm and pre-existing CRBBB. Patients with 2 or more predictors had significantly higher PPI rates than those with 1 or less predictor (67% [18 of 27 patients] vs. 1% [2 of 229 patients], p&lt;0.001).

Conclusions

LVOT area /annulus area, ΔMSID and pre-existing CRBBB were identified as powerful independent predictors for PPI after TAVI. Higher valve implantation is important to prevent excessive PPI especially for patients with pre-procedural tapered-shaped LVOT, short membranous septum or pre-existing CRBBB.

PPI rates stratified by predictors

Funding Acknowledgement

Type of funding source: None

A novel therapeutic approach for coronary inflammation and lymphatic vessels using non-invasive low-intensity pulsed ultrasound in a porcine model with DES-induced coronary hyperconstricting responses

Background

The coronary adventitia harbors lymphatic vessels (LVs). We previously demonstrated that coronary adventitial inflammation and LV dysfunction play important roles in the pathogenesis of coronary artery spasm, including drug-eluting stent (DES)-induced coronary hyperconstricting responses, in pigs and humans. However, a direct therapeutic approach to the coronary adventitia remains to be developed.

Purpose

In this study, we aimed to examine whether our novel and non-invasive therapy with low-intensity pulsed ultrasound (LIPUS) ameliorates DES-induced coronary hyperconstricting responses, and if so, what mechanisms are involved.

Methods

An everolimus-eluting stent (EES) was implanted into the left anterior descending (LAD) coronary artery in normal male pigs. They were randomly assigned to the LIPUS or the sham therapy groups. After EES implantation, in the LIPUS group, LIPUS (32 cycles, 193 mW/cm2) was applied to the heart at 3 different levels (proximal and distal stent edges and middle portion of the stent) through X-ray fluoroscopy for 20 min at each level for every other day for 2 weeks (6 days in total) (Fig. 1A, B). The sham therapy group was treated in the same manner but without LIPUS. At 4 weeks after the procedure, we performed coronary angiography to examine coronary vasoconstricting responses to intracoronary serotonin in vivo. Finally, stented coronary vessels were harvested for immunohistochemistry of vasa vasorum (vWF), LVs (LYVE-1), vascular inflammation (CD68-positive macrophages and IL-1β expression), vascular endothelial growth factor A (VEGF-A, angiogenesis marker), VEGF-C and VEGF receptor 3 (VEGFR3, lymphangiogenesis markers).

Results

Coronary vasoconstricting responses to intracoronary serotonin at the DES edges in the LAD were significantly enhanced in the sham group but were significantly suppressed in the LIPUS group, while those responses were comparable at the non-DES implanted left circumflex (LCx) coronary artery between the 2 groups (Fig. 1C, D). In addition, in vivo lymph transport speed was significantly faster in the LIPUS group than in the sham group (Fig. 1E–G). In histological analysis, the number of LVs was significantly increased in the LIPUS group compared with the sham group, whereas those of CD68 and IL-1β expressions were significantly reduced in the LIPUS group compared with the sham group. In contrast, the density of vasa vasorum was comparable between the 2 groups. Mechanistically, the extents of VEGF-C and VEGFR3 expressions were increased in the LIPUS group, whereas that of VEGF-A was comparable between the 2 groups (Fig. 1G–K). Importantly, there were significant correlations among the LV-related changes and enhanced coronary vasoconstricting responses.

Conclusion

These results provide the first evidence that the LIPUS therapy ameliorates DES-induced coronary hyperconstricting responses in pigs in vivo through structural and functional alterations of LVs (Fig. 1L).

Figure 1

Funding Acknowledgement

Type of funding source: None

The role of B cells and IgG in aortic dissection

Background

Aortic dissection (AD) is one of the destructive and fatal aortic diseases, for which molecular pathogenesis is largely unknown. Recent studies have highlighted the importance of inflammatory response in AD. We and others reported that B cells and immunoglobulins participate in pathogenesis of abdominal aortic aneurysm, another form of aortic destructive disease, by promoting inflammatory response. It is not known whether and how B cells participate in AD pathogenesis.

Methods and results

Immunohistochemical staining of human AD tissue revealed that B cells were clustered together with T cells, macrophages and neutrophils at the entry site of AD with medial disruption. B cell cluster was also observed at the site of medial disruption in mouse model of AD that was induced by continuous infusion of beta-aminopropionitrile and angiotensin II (BAPN+AngII). In muMT mouse, which is deficient for B cells and immunoglobulins due to genetic deletion of immunoglobulin heavy chain, BAPN+AngII induced significantly less severe AD compared to that in wild type. Depositions of IgG and fibrinogen, one of the endogenous antigen for natural IgG, were observed after BAPN+AngII infusion before and after AD development in wild type mice. Deposition of fibrinogen was also observed in mMT mice after BAPN+AngII infusion. The rate of aortic rupture and sudden death was approximately 42% in wild type mice, while that in muMT mouse was 12% (P&lt;0.05). Administration of mouse normal polyclonal IgG to muMT mice resulted in dramatic increase in aortic rupture and sudden death, starting at day 7 of BAPN+AngII infusion, and reaching 69% of rupture rate, indicating the critical role of IgG in AD.

Conclusion

These findings demonstrated B cells and IgG are critically involved in the destructive inflammation of AD pathogenesis. Further, the deposition of fibrinogen, one of the targets of natural IgG, precedes the development of AD. Our findings may provide the conceptual foundation of the diagnostic strategy for on-going tissue destruction and for the therapeutic opportunities to intervene the progressive tissue destruction in AD.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The Japan Society for the Promotion of Science

Phase I/II study of adding intraperitoneal paclitaxel in patients with pancreatic cancer and peritoneal metastasis

BACKGROUND

Intraperitoneal chemotherapy using paclitaxel is considered an experimental approach for treating peritoneal carcinomatosis. This study aimed to determine the recommended dose, and to evaluate the clinical efficacy and safety, of the combination of intravenous gemcitabine, intravenous nab-paclitaxel and intraperitoneal paclitaxel in patients with pancreatic cancer and peritoneal metastasis.

METHODS

The frequencies of dose-limiting toxicities were evaluated, and the recommended dose was determined in phase I. The primary endpoint of the phase II analysis was overall survival rate at 1 year. Secondary endpoints were antitumour effects, symptom-relieving effects, safety and overall survival.

RESULTS

The recommended doses of intravenous gemcitabine, intravenous nab-paclitaxel and intraperitoneal paclitaxel were 800, 75 and 20 mg/m² respectively. Among 46 patients enrolled in phase II, the median time to treatment failure was 6·0 (range 0-22·6) months. The response and disease control rates were 21 of 43 and 41 of 43 respectively. Ascites disappeared in 12 of 30 patients, and cytology became negative in 18 of 46. The median survival time was 14·5 months, and the 1-year overall survival rate was 61 per cent. Conversion surgery was performed in eight of 46 patients, and those who underwent resection survived significantly longer than those who were not treated surgically (median survival not reached versus 12·4 months). Grade 3-4 haematological toxicities developed in 35 of 46 patients, whereas non-haematological adverse events occurred in seven patients.

CONCLUSION

Adding intraperitoneal paclitaxel had clinical efficacy with acceptable tolerability.

The effect of two composite placement techniques on fracture resistance of MOD restorations with various resin composites

OBJECTIVE

The aim of this in vitro study was to compare the effect of two restorative placement techniques, centripetal incremental technique (CIT) and bulk-fill technique (BT) on the fracture resistance of Class II MOD restorations with various resin composites in molar teeth.

MATERIALS AND METHODS

Fifty-six extracted, caries free third molars were prepared with MOD preparations and restored with resin composites. The specimens were divided into two groups by placement technique, centripetal incremental technique (CIT) and bulk-fill technique (BT). Each group was subdivided into four groups according to resin composite: hybrid (Aelite LS), nano-hybrid (Virtuoso Universal), bulk fill (Filtek One Bulk Fill) and the micro-hybrid (Herculite XRV) as the control.

RESULTS

Two-way analysis of variance test (ANOVA) followed by the multiple comparison procedure, Student-Newman-Keuls Method showed no a statistically significant difference between placement techniques and fracture resistance of Class II resin composite restorations (P > 0.05). Herculite XRV resisted a significantly higher load before fracture than the other three materials at a 0.05 level of significance, while Virtuoso Universal scored the lowest load.

CONCLUSIONS

There was no significant effect of the two placement techniques on the fracture resistance of Class II resin composite restorations CLINICAL SIGNIFICANCE: Resin composite restorations in Class II MODs using a simplified bulk fill placement technique showed no significant difference in fracture resistance with the centripetal technique in molar teeth.

Synthesis and Synthetic Application of Chloro- and Bromofuroxans

Furoxans are potentially useful heteroaromatic units in pharmaceuticals and agrichemicals. However, the applications for furoxan-based compounds have been hampered due to the underdevelopment of their synthetic methods. Herein, we report a new synthetic approach for the synthesis of chloro- and bromofuroxans. The starting materials were dichloro- and dibromofuroxans, and the substituents were directly introduced to the furoxan ring in a modular fashion. The synthesized monohalofuroxans served as substrates for the installation of a second substituent to prepare further functionalized furoxans.

Association between dexamethasone treatment and alterations in serum concentrations of trace metals

Previously, a significant elevation in the serum levels of iron (Fe) was observed within a few days after the initiation of cisplatin (CDDP)-based chemotherapy. To clarify the underlying mechanisms, the serum concentration of hepcidin, a negative regulator of Fe release, was determined in the clinical samples obtained from six patients with cancer. The result showed that the serum concentration of hepcidin in patients receiving CDDP-based chemotherapy was significantly increased after 4-6 days of treatment, in comparison to the baseline level, suggesting that aforementioned excessive systemic Fe was not explained by the change of serum hepcidin level. All these patients received antiemetic premedication. We next evaluated of the effects of Pt-containing drugs and prophylactic antiemetic dexamethasone medication on the serum concentration of trace metals in mice, and on the hepatic and renal concentration of trace metals. The serum concentrations of Fe, Cu, and Zn in the CDDP-treated and oxaliplatin-treated mice were not significantly altered in comparison to those of the vehicle-treated control group. The serum concentrations of Fe, Cu, and Zn were increased after 24 h of dexamethasone treatment, compared to those of the control group (P < 0.05). The hepatic concentration of Mn was significantly reduced, whereas those of Fe and Cu inclined to diminish. The present findings suggest that dexamethasone can partly contribute to the changes in the serum concentrations of trace metals during anticancer chemotherapy.

In silico experiments of bone remodeling explore metabolic diseases and their drug treatment

Bone structure and function are maintained by well-regulated bone metabolism and remodeling. Although the underlying molecular and cellular mechanisms are now being understood, physiological and pathological states of bone are still difficult to predict due to the complexity of intercellular signaling. We have now developed a novel in silico experimental platform, V-Bone, to integratively explore bone remodeling by linking complex microscopic molecular/cellular interactions to macroscopic tissue/organ adaptations. Mechano-biochemical couplings modeled in V-Bone relate bone adaptation to mechanical loading and reproduce metabolic bone diseases such as osteoporosis and osteopetrosis. V-Bone also enables in silico perturbation on a specific signaling molecule to observe bone metabolic dynamics over time. We also demonstrate that this platform provides a powerful way to predict in silico therapeutic effects of drugs against metabolic bone diseases. We anticipate that these in silico experiments will substantially accelerate research into bone metabolism and remodeling.

Minimally invasive oesophagectomy with extended lymph node dissection and thoracic duct resection for early-stage oesophageal squamous cell carcinoma

BACKGROUND

Oesophageal squamous cell carcinoma is an aggressive disease owing to early and widespread lymph node metastases. Multimodal therapy and radical surgery may improve prognosis. Few studies have investigated the efficacy of radical lymph node and thoracic duct resection.

METHODS

Patients with oesophageal squamous cell carcinoma who underwent transthoracic minimally invasive oesophagectomy (TMIE) for cancer at Keio University Hospital between January 2004 and December 2016 were selected. Between 2004 and 2008, TMIE was performed in the lateral decubitus position without thoracic duct resection (standard TMIE). From 2009 onwards, TMIE with extended lymph node and thoracic duct resection was introduced (extended TMIE). Demographics, co-morbidity, number of retrieved lymph nodes, pathology, postoperative complications and recurrence-free survival (RFS) were compared between groups.

RESULTS

Forty-four patients underwent standard TMIE and 191 extended TMIE. There were no significant differences in clinical and pathological tumour stage or postoperative complications. The extended-TMIE group had more lymph nodes removed at nodal stations 106recL and 112. Among patients with cT1 N0 disease, RFS was better in the extended-TMIE group (P < 0·001), whereas there was no difference in RFS between groups in patients with advanced disease.

CONCLUSION

Extended TMIE including thoracic duct resection increased the number of lymph nodes retrieved and was associated with improved survival in patients with cT1 N0 oesophageal squamous cell carcinoma.

P6494Activation of focal adhesion kinase is involved in pathogenesis of aortic dissection in mice

Background

Aortic dissection (AD) is a fatal disease where the media of the aorta suddenly fail. Currently, Molecular pathogenesis of AD is unknown. Recently, we discovered that the activity of MRTF-A, a mechanosensitive transcriptional regulator, promotes AD development. The activity of MRTF-A is regulated by mechanical stress to cells, which is transduced through focal adhesion and actin dynamics. However, it is currently unknown whether the mechanotransduction mechanism is involved in AD pathogenesis.

Purpose

We investigated the role of focal adhesion kinase (FAK), a signaling molecule that transduces mechanostress from focal adhesion to actin dynamics, in AD pathogenesis.

Methods

We created a mouse model of AD with a continuous infusion of beta-aminopropionitrile (150 mg/kg/day), a collagen crosslink inhibitor, and angiotensin II (1,000 ng/kg/min) (BAPN + AngII) by an osmotic pump. This model caused about 60% death in all mice due to AD rupture within 2 weeks. In this model, we examined the severity and mortality rate of aortic dissection after 2 weeks in mice administered with PND-1186, an orally available FAK inhibitor, and in those treated with vehicle (n=20 for each group). We performed immunochemical staining, immunofluorescence staining and Western blot for activated (phosphorylated) FAK (pFAK) to evaluate the activation status of FAK in the aortic tissue. We also performed transcriptome analysis of the aortic tissue in with and without PND-1186 with BAPN + AngII stimulation before AD development.

Results

Immunochemical staining revealed that FAK was inactive in normal mouse aorta, but was strongly activated in the aortic walls after AD development. Immunofluorescence staining showed that FAK was activated mainly in smooth muscle cells after AD development. Western blot analysis also revealed that FAK was activated in 3 days after BAPN + AngII infusion before AD development, followed by transient reduction at day 7, and re-activation after AD at day 14. Significantly, administration of PND-1186 resulted in a significant reduction in the severity of AD in the aortic arch (1.96±0.41 mm in vehicle group, 0.66±0.29 mm in PND group, P<0.05). In addition, survival rate improved from 36.4% to 80.0% by administration of PND-1186 (P<0.01). In immunofluorescence staining, the PND-1186 treated group showed weaker staining of pFAK. Transcriptome analysis showed that genes for hematopoiesis and immune system were suppressed in PND-1186 treated group.

Conclusions

These findings proved that FAK plays a central role in the pathogenesis of AD probably by transmitting pathological stress to the aortic wall to cause tissue destruction. We propose that FAK is a potential therapeutic target for limiting the fatal destruction of the aortic wall of AD.

P1032Efficacy and safety of radiofrequency catheter ablation for atrial fibrillation in patients undergoing hemodaialysis

Introduction

Although radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) has become a standard therapy, the ablation outcomes in patients undergoing hemodialysis (HD) has not been fully elucidated. The present study aimed to evaluate the clinical outcomes of RFCA for AF in patients undergoing HD.

Methods

Twenty-three patients undergoing HD (17 men, age 65±8 years, 19 paroxysmal AF) who underwent RFCA for drug-refractory AF in two institutes were enrolled in the study and defined as HD group. The clinical parameters, recurrence free rate and frequency of periprocedural complications were compared to 46 randomly selected age, gender and left atrial diameter matched controls not requiring HD defined as non-HD group (34men, age 67±7 years, 38 paroxysmal AF).

Results

The patients in HD group had a significantly lower body mass index (21±3 vs. 25±3 P<0.01), higher prevalence of coronary artery disease (30% vs. 10% P=0.04), and higher prevalence of congestive heart failure (52% vs. 10% P<0.01) compared to patients in non-HD group. Echocardiography indicated lower left ventricular ejection fraction (57±17% vs. 65±9% P=0.02), higher E/e' (20±8 vs. 12±4 P<0.01), higher tricuspid regurgitation pressure gradient (30mmHg vs. 24mmHg P<0.01) and more impaired left ventricular diastolic function in HD group. All the subjects underwent bilateral pulmonary vein isolation plus additional linear lesion. The number of ablation procedure was similar between the two groups (1.43±0.5 vs. 1.46±0.6 P=0.88). During the follow-up period of 37±25 months after the last procedure, the arrhythmia free rate was similar between the two groups (86% vs. 84% log-rank P=0.82). Vascular access complication occurred in two patients in HD group, and pericardial effusion occurred in one patient in non-HD group, while no life-threatening complications were observed in either group. Cardiogenic cerebral infarction occurred in one patient in non-HD group. Discontinuation of oral anticoagulation after the ablation was more often seen in the HD group compared to non-HD group (91% vs. 60% P<0.01).

Conclusions

Although patients undergoing HD had more impaired left ventricular systolic and diastolic function, RFCA for AF in patients with HD was shown to be as effective and safe as in non-HD patients. RFCA may be an efficient approach to manage AF in patients undergoing HD.

P4601Reduced exercise capacity and clinical outcomes following acute myocardial infarction

Background

Reduced exercise capacity is known to be an important predictor of poor prognosis and disability in patients with cardiovascular diseases and chronic heart failure, and even members of the general population. However, data about exercise capacity assessed by cardiopulmonary exercise testing (CPX) in acute myocardial infarction (AMI) patients who underwent primary percutaneous coronary intervention (PCI) is scarce. The purpose of this study is to assess the associated factors and clinical influence of exercise capacity measured by CPX in AMI patients.

Methods

Among 594 consecutive AMI patients who underwent primary PCI, we examined 136 patients (85.3% men, 64.9±11.9 years) who underwent CPX during hospitalization for AMI. CPX was usually performed five days after the onset of AMI. Reduced exercise capacity was defined as peak oxygen consumption (peak VO2) ≤12. Clinical outcomes including all-cause death, myocardial infarction, and hospitalization due to heart failure were followed.

Results

Among 136 patients, reduced exercise capacity (peak VO2 ≤12) was seen in 38 patients (28%). Patients with reduced exercise capacity were older, more likely to have hypertension, and had lower renal function. In echocardiography, patients with reduced exercise capacity had higher E/e' and larger left atria. Median follow-up term was 12 months (interquartile range: 9–22). The occurrence of composite endpoints of all-cause death, myocardial infarction, and hospitalization due to heart failure was significantly higher in patients with peak VO2≤12 than those with peak VO2>12 (p<0.001). Multivariate logistic analysis showed that E/e' (Odds ratio, 1.19, 95%, confidence interval 1.09 to 1.31, p<0.001) was an independent predictor of reduced exercise capacity (peak VO2≤12).

Cumulative incidence of clinical events

Conclusion

Diastolic dysfunction is associated with reduced exercise capacity following successful primary PCI in AMI patients and may lead to poorer clinical outcomes.

P6493Syk activation is a defense mechanism in murine model of aortic dissection

Background

Aortic dissection (AD) is a serious clinical condition with unknown etiology that frequently results in fatal outcome. Recent studies showed essential role of inflammatory response both in promoting AD and aortic aneurysm (AA). However, the difference of the molecular pathogenesis between AD and AA is unclear. Previously, we reported that Syk, a tyrosine kinase that regulates differentiation and activation of inflammatory cells, promotes AA formation in a mouse model.

Objective

In the current study, we investigated the role of Syk in AD.

Methods and results

A mouse AD model was created by continuous infusion of beta-aminopropionitrile (125 mg/kg/day) and angiotensin II (1,000 ng/min/kg) (BAPN+AngII), which caused AD in approximately 80% of mice within 14 days. Immunohistochemical staining for activated (phosphorylated) Syk (pSyk) revealed that Syk was inactive in normal mouse aorta, but was activated in the aortic walls after AD development. Double immunofluorescence staining for pSyk and smooth muscle alpha actin showed that Syk was active not only in the infiltrating inflammatory cells, but also in smooth muscle cells in AD tissue. Western blot analysis revealed that BAPN+AngII treatment caused Syk activation at 3 days before AD development, followed by transient suppression, and reactivation at 14 days after AD development. We examined the significance of Syk activation in AD by treating mice with fostamatinib, a specific Syk inhibitor, before and during BAPN+AngII infusion. Notably, fostamatinib-treated group developed more severe AD compared to the vehicle-treated group. The AD lesion length was 3.80±0.86 mm for vehicle group and 8.87±1.69 mm for fostamatinib group (P<0.05, n=12 for each group). In addition, fostamatinib significantly worsened the mortality of mice due to the rupture of the aorta from 0% to 42% (P<0.05, n=12 for each group). Transcriptome analysis revealed that fostamatinib suppressed both positive and negative regulators of immune response, defense response and inflammatory response.

Conclusions

These findings uncovered the previously unrecognized role of Syk for protecting the aortic tissue in AD pathogenesis, and suggested fundamentally different disease mechanisms of AD and AA.

P4620Circulating concentration of presepsin improves early prediction of short-term mortality in patients treated at medical cardiac intensive care units

Background

Presepsin, a subtype of soluble CD14, is an inflammatory marker, which largely reflects monocytic activation. Presepsin appears to be an accurate diagnostic marker of sepsis, but its clinical significance remains unclear in cardiovascular disease.

Purpose

This prospective study aimed to investigate the predictive value of plasma presepsin levels on admission to medical (non-surgical) cardiac intensive care units (MCICUs) for short-term mortality.

Methods

We examined 1560 patients hospitalized in MCICUs and measured the baseline plasma presepsin levels at admission.

Results

Acute coronary syndrome was present in 46% of the patients, and acute decompensated heart failure in 36%. Before MCICUs admission, emergent coronary angiography or percutaneous coronary intervention was performed in 36%, mechanical ventilation was required for respiratory insufficiency in 2.1%, and intraaortic balloon pumps were needed for hemodynamic instability in 8.9%. During 6 months after admission, there were 113 (7.2%) deaths. Patients who died were older (median: 77 vs. 71 years, P<0.0001); had higher levels of presepsin (263 vs. 119 pg/mL, P<0.0001), B-type natriuretic peptide (BNP: 696 vs. 186 pg/mL, P<0.0001), high-sensitivity troponin T (hsTnT: 81 vs. 47 pg/mL, P=0.004), and high-sensitivity C-reactive protein (13.8 vs. 2.2 mg/L, P<0.0001); and had lower levels of estimated glomerular filtration rate (50 vs. 65 mL/min/1.73m2, P<0.0001) and left ventricular ejection fraction (43% vs. 51%, P<0.0001) than those of the survivors. In the multivariate Cox regression analysis, higher levels of presepsin (P=0.0002), BNP (P=0.04), and hsTnT (P=0.009) were all independent predictors of 6-month deaths. Quartiles of presepsin levels were associated with higher mortality rates within 6 months after admission (Table). Adding presepsin levels to a baseline model that included established risk factors, BNP, and hsTnT further enhanced reclassification (P=0.004) and discrimination (P=0.003) beyond that of the baseline model.

Mortality rates according to presepsin Presepsin quartile 1st 2nd 3rd 4th P value ≤80 pg/mL 81–124 pg/mL 125–232 pg/mL >232 pg/mL 1-month mortality 0.8% 2.0% 3.3% 8.0% <0.0001 6-month mortality 0.8% 3.8% 8.2% 16.3% <0.0001

Conclusions

Presepsin levels at admission could improve the prediction of short-term mortality in patients hospitalized at MCICUs.

Dithiothreitol-Measured Oxidative Potential of Size-Segregated Particulate Matter in Fukuoka, Japan: Effects of Asian Dust Events

Oxidative potential is an important property of particulate matter (PM) that has been regarded as a more health-relevant metric than PM mass. We investigated the oxidative potential of size-segregated PM and effects of Asian dust events in Fukuoka, western Japan. Aerosol particles with diameters smaller and larger than 2.5 μm (fine and coarse particles, respectively) were collected continually from 16 March through 26 May 2016. The oxidative potential was analyzed using dithiothreitol (DTT) assay; chemical components of PM were also found. Air-volume normalized oxidative potential quantified by DTT assay (DTT_v) was significantly higher during Asian dust events than during nondust-event days. The mean DTT_v of fine and coarse particles during Asian dust events were, respectively, 1.5 and 2.7 times higher than that during nonevent days. DTT_v of fine particles was highly correlated with elements dominated by anthropogenic combustion sources and with the elements emitted from multiple sources including mineral dust and combustion sources. DTT_v of coarse particles strongly correlated with the mineral dust derived elements, suggesting concentration of mineral dust particles as an important controlling factor especially for the oxidative potential of the coarse particles. We estimated the contributions of water-soluble transition metals to the oxidative potential of PM. Water-soluble transition metals (mainly Cu and Mn) can explain only approximately 37% and 60% of the measured oxidative potential of fine and coarse particles, respectively, suggesting substantial contributions of aerosol components other than water-soluble transition metals such as quinones and insoluble minerals.