Construction of a [15]Annulenone-[15]annulenyl Ion Cycle

Previously, we have reported the synthesis of furanoid [15]annulenones and their protonated species. With the benefits of FT NMR spectroscopy, some of experiments have now been reinvestigated. The annulenone may undergo dynamic conformational changes to provide an interesting cycle, which can be driven by protonation- deprotonation sequence

Synthetic and biochemical studies on the effect of persulfidation on disulfide dimer models of amyloid β42 at position 35 in Alzheimer's etiology

Protein persulfidation plays a role in redox signaling as an anti-oxidant. Dimers of amyloid β42 (Aβ42), which induces oxidative stress-associated neurotoxicity as a causative agent of Alzheimer's disease (AD), are minimum units of oligomers in AD pathology. Met35 can be susceptible to persulfidation through its substitution to homoCys residue under the condition of oxidative stress. In order to verify whether persulfidation has an effect in AD, herein we report a chemical approach by synthesizing disulfide dimers of Aβ42 and their evaluation of biochemical properties. A homoCys-disulfide dimer model at position 35 of Aβ42 formed a partial β-sheet structure, but its neurotoxicity was much weaker than that of the corresponding monomer. In contrast, the congener with an alkyl linker generated β-sheet-rich 8–16-mer oligomers with potent neurotoxicity. The length of protofibrils generated from the homoCys-disulfide dimer model was shorter than that of its congener with an alkyl linker. Therefore, the current data do not support the involvement of Aβ42 persulfidation in Alzheimer's disease

Bilateral verses bilateral with tri-segmental endoscopic drainage using metal stents for high-grade malignant hilar biliary obstructions: A multicenter, randomized controlled trial: BRAVE study (BRAVE study)

Introduction: Bilateral endoscopic drainage with self-expanding metallic stent (SEMS) can be used to manage hilar malignant biliary obstruction (HMBO) more effectively in comparison to unilateral drainage. An increased drainage area is predicted to prolong stent patency and patient survival. However, few reports have described the utility of trisegmental drainage and the benefits of using trisegmental drainage remain unknown. Thus, we launched a randomized clinical trial (RCT) to compare the clinical outcomes between bilateral and trisegmental drainage using SEMSs in patients with high-grade HMBO. Methods and analysis: This study was conducted as a multicenter randomized control trial (RCT) in 8 high-volume medical centers in Japan, and will prove the non-inferiority of bilateral drainage to trisegmental drainage. Patients with unresectable HMBO with Bismuth type IIIa or IV who pass the inclusion and exclusion criteria will be randomized to receive bilateral or trisegmental drainage at a 1:1 ratio. At each center, the on-site study investigators will obtain informed consent from the candidates, and will use an electronic data capture system (REDCap) to input necessary information, and register candidates with the registration secretariat. The primary endpoint is the rate of non-recurrent biliary obstruction (RBO) at 180 days after SEMSs placement. A -10% non-inferiority margin is assumed in the statistical analysis of the primary endpoint. Secondary endpoints include the rate of technical and clinical success, time to recurrent biliary obstruction (TRBO), causes of RBO, procedure-related adverse events (AEs), procedure time, TRBO with or without endoscopic sphincterotomy, overall survival, and the technical and clinical success rates at reintervention. Discussion: If the non-inferiority of bilateral drainage is demonstrated, it is predicted that the procedure time will be shortened and the medical cost will be reduced, which will be beneficial to the patient and the medical economy

AMD-associated submacular hemorrhage

Purpose To investigate the clinical features, treatment options, and visual outcomes of submacular hemorrhage (SMH) secondary to neovascular age-related macular degeneration (nAMD). Design A retrospective, observational case series. Methods Setting: Multicenter institutional setting. Patient Population: A total of 127 patients (127 eyes; 88 men, 39 women; (mean age, 74.2 years)) diagnosed with AMD-associated SMHs exceeding 2 disc diameters involving the fovea. Observation: The AMD types, previous treatments, treatment options, anatomic findings, and best-corrected visual acuity (BCVA) were assessed. Main Outcome Measures: Clinical features, treatment options, and visual outcomes of SMHs secondary to nAMD. Results Thirty-two eyes had typical AMD, 94 eyes polypoidal choroidal vasculopathy (PCV), and one eye retinal angiomatous proliferation. Eighty-five eyes were treatment-naïve; 42 eyes were treated previously: anti-vascular endothelial growth factor (VEGF) therapy (n = 26), photodynamic therapy (n = 3), and combined therapy (n = 13). Treatment of SMHs included vitrectomy (36 eyes), pneumatic displacement (49 eyes), and anti-VEGF monotherapy (42 eyes). The final BCVA improved significantly in treatment-naïve cases from 0.86 to 0.62 logarithm of the minimal angle of resolution (logMAR) unit (Snellen equivalent from 20/145 to 20/83) and from 0.80 to 0.56 (Snellen equivalent from 20/126 to 20/73) in PCV cases. Meanwhile, the BCVA logMAR values improved from 1.15 to 0.75 (Snellen equivalent from 20/283 to 20/112) and from 0.87 to 0.63 (Snellen equivalent from 20/148 to 20/85) in eyes that underwent vitrectomy or pneumatic displacement, respectively. In eyes with BCVAs between 20/133 to 20/40 at SMH onset, the final VA in the pneumatic displacement group was better than in the anti-VEGF monotherapy group. One eye had a retinal detachment and 1 eye had a macular hole in the vitrectomy group, and 5 eyes had a vitreous hemorrhage in the pneumatic displacement group. Conclusions The recommended treatment for SMHs secondary to nAMD exceeding 2 disc area and with BCVA below 20/40 is vitrectomy or pneumatic displacement for visual improvement

A multicenter survey for submacular hemorrhage

Purpose To evaluate the clinical characteristics, treatment trends, and visual prognosis of submacular hemorrhage (SMH) secondary to neovascular age-related macular degeneration (nAMD) and retinal arterial macroaneurysm (RAM). Methods This retrospective study enrolled 187 Japanese patients with SMH at 10 institutions from 2015 to 2018. Medical records including SMH etiology, best-corrected visual acuity (BCVA), fundus photographs, optical coherence tomography images, and selected treatments were analyzed. Results Major causes of SMH were typical nAMD (tnAMD) (18%), polypoidal choroidal vasculopathy (PCV) (50%) and RAM (29%). Age, male/female ratio, baseline BCVA, central retinal thickness, and involved retinal layers were significantly different between etiologies (all P<0.0001). Treatment with anti-vascular endothelial growth factor drugs with and without intravitreal gas injection was chosen for half of eyes in the tnAMD and PCV groups, whereas vitrectomy was performed in 83.7% of eyes with RAM. The final BCVA improved significantly from baseline in the PCV and RAM groups (P = 0.0009, P<0.0001) and final BCVA was significantly better in the PCV group at a level similar to the other groups (P = 0.0007, P = 0.0008). BCVA improvement from baseline was significantly greater in the RAM group compared with the tnAMD (P = 0.0152) and PCV (P = 0.017) groups. Multivariate analysis revealed better final BCVA was significantly associated with younger age (P = 0.0054), better baseline BCVA (P = 0.0021), RAM subtype (P = 0.0446), and no tnAMD (P = 0.001). Conclusions The characteristics of, and treatment strategy for, SMH were different between the underlying diseases. Anti-vascular endothelial growth factor treatment with or without expansile gas was mainly chosen for SMH in tnAMD and PCV, whereas vitrectomy with gas was the most common treatment for RAM, and the higher rate for vitrectomy might result in the greater BCVA improvement in the RAM group than in the other groups. Final BCVA was better in PCV, RAM, and tnAMD, in that order, because patients with PCV were younger and had better baseline BCVA

Background Factors Affecting Visual Acuity at Initial Visit in Eyes with Central Retinal Vein Occlusion : Multicenter Study in Japan

Purpose: To determine the baseline characteristics of patients with central retinal vein occlusion (CRVO) that were significantly associated with the best-corrected visual acuity (BCVA) at the initial examination. Methods: This was a retrospective multicenter study using the medical records registered in 17 ophthalmological institutions in Japan. Patients with untreated CRVO (≥20-years-of-age) who were initially examined between January 2013 and December 2017 were studied. The patients’ baseline factors that were significantly associated with the BCVA at the initial examination were determined by univariate and multivariate linear regression analyses. Results: Data from 517 eyes of 517 patients were analyzed. Univariate analyses showed that an older age (r = 0.194, p < 0.001) and the right eye (r = −0.103, p < 0.019) were significantly associated with poorer BCVA at the initial visit. Multivariate analyses also showed that an older age (β = 0.191, p < 0.001) and the right eye (β = −0.089, p = 0.041) were significantly associated with poorer BCVA at the initial visit. Conclusions: The results indicate that an older age, a known strong factor, and the right eye were significantly associated with poorer BCVA at the initial visit to the hospital. These results suggest that functional and/or anatomical differences between the right and left eyes may be involved in these results

Natriuretic peptide receptor guanylyl cyclase-A pathway counteracts glomerular injury evoked by aldosterone through p38 mitogen-activated protein kinase inhibition

Guanylyl cyclase-A (GC-A) signaling, a natriuretic peptide receptor, exerts renoprotective effects by stimulating natriuresis and reducing blood pressure. Previously we demonstrated massive albuminuria with hypertension in uninephrectomized, aldosterone-infused, and high salt-fed (ALDO) systemic GC-A KO mice with enhanced phosphorylation of p38 mitogen-activated protein kinase (MAPK) in podocytes. In the present study, we examined the interaction between p38 MAPK and GC-A signaling. The administration of FR167653, p38 MAPK inhibitor, reduced systolic blood pressure (SBP), urinary albumin excretion, segmental sclerosis, podocyte injury, and apoptosis. To further investigate the local action of natriuretic peptide and p38 MAPK in podocytes, we generated podocyte-specific (pod) GC-A conditional KO (cKO) mice. ALDO pod GC-A cKO mice demonstrated increased urinary albumin excretion with marked mesangial expansion, podocyte injury and apoptosis, but without blood pressure elevation. FR167653 also suppressed urinary albumin excretion without reducing SBP. Finally, we revealed that atrial natriuretic peptide increased phosphorylation of MAPK phosphatase-1 (MKP-1) concomitant with inhibited phosphorylation of p38 MAPK in response to MAPK kinase 3 activation, thereby resulting in decreased mRNA expression of the apoptosis-related gene, Bax, and Bax/Bcl2 ratio in cultured podocytes. These results indicate that natriuretic peptide exerts a renoprotective effect via inhibiting phosphorylation of p38 MAPK in podocytes.</p