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Organic-inorganic hybrid gels containing Si-vinylene units have been synthesized by a hydrosilylation reaction of trior tetra-ethynyl aryl compounds, 1,3,5-triethynylbenzene (TEB), 3,3 0 ,5,5 0 -tetraethynylbiphenyl (TEBP), or tetrakis(4-ethynylphenyl)-methane (TEPM), and bisdimethylsilyl compounds, 1,1,3,3-tetramethyldisiloxane (TMDS) or 1,4-bisdimetylsilylbenzene (BDMSB), in toluene. Network structure of the resulting gels was quantitatively characterized by a scanning microscopic light scattering. The reactions yielded the gels having homogeneous network structure of 1.5-2.9 nm mesh size under the monomer concentrations that were relatively higher than the critical gelation concentration. The gels obtained from TEB showed broad absorption in the range from 340 to 370 nm, and emission in the range from 440 to 490 nm. The TEB-BDMSB gels showed remarkable red shift of the emission in comparison with that of the corresponding reaction solutions derived from the network formed by r-p conjugation. The TEPM-TMDS, BDMSB gels exited by 280 nm showed not only the emission peak at around 360 nm derived from TEPM, but the broad peak at around 420 nm, which should be derived from interaction between phenyl groups of TEPM in the gels.

Aims:The long-term prognostic value of the bioavailability of l-arginine, an important source of nitric oxide for the maintenance of vascular endothelial function, has not been investigated fully. We therefore investigated the relationship between amino acid profile and long-term prognosis in patients with a history of standby coronary angiography. Methods:We measured the serum concentrations of l-arginine, l-citrulline, and l-ornithine by high-speed liquid chromatography. We examined the relationship between the l-arginine/l-ornithine ratio and the incidence of all-cause death, cardiovascular death, and major adverse cardiovascular events (MACEs) in 262 patients (202 men and 60 women, age 65±13 years) who underwent coronary angiography over a period of ≤ 10 years.Results: During the observation period of 5.5±3.2 years, 31 (12%) patients died, including 20 (8%) of cardiovascular death, while 32 (12%) had MACEs. Cox regression analysis revealed that l-arginine/l-ornithine ratio was associated with an increased risk for all-cause death (unadjusted hazard ratio, 95% confidence interval) (0.940, 0.888-0.995) and cardiovascular death (0.895, 0.821-0.965) (p＜0.05 for all). In a mod el adjusted for age, sex, hypertension, hyperlipidemia, diabetes, current smoking, renal function, and log10-transformed brain natriuretic peptide level, cardiovascular death (0.911, 0.839-0.990, p=0.028) retained an association with a low l-arginine/ l-ornithine ratio. When the patients were grouped according to an l-arginine/l-ornithine ratio of 1.16, the lower l-arginine/l-ornithine ratio group had significantly higher incidence of all-cause death, cardiovascular death, and MACEs. Conclusion:A low l-arginine/l-ornithine ratio may be associated with increased 10-year cardiac mortality.

Background: Extracellular signal-regulated kinases 1/2 (ERK1/2) play significant roles in proliferation, migration, and cell death. Tyrosine kinase inhibitors (TKIs) have a serious concern for cardiotoxicity and these agents target to EGFR/Ras/Raf/MEK/ERK pathway. In previous reports, SM22α-Cre drived EGFR receptor knockout mice revealed cardiac dysfunction. Hypothesis: We hypothesized if SM22α-Cre drived ERK2 contributed to the cardiac dysfunction mimicking toxicity of TKIs. Methods & Results: We generated SM22α-drived ERK2 knockout mice (SM22α-EKO) by crossing SM22α-Cre mice and ERK2-flox mice. The protein expressions of ERK2 in aorta and heart were markedly lowered in SM22α-EKO, whereas similar in brain, kidney, liver, spleen, and bone marrow. SM22α-EKO displayed lower exercise tolerance and peak oxygen consumptions. Echocardiography revealed left ventricular thickness and dilatation with decreased % fraction shortening (21±4 vs. 38±2%, p=0.0002). Pathological study showed that heart weight was twice accompanied by increases in cardiomyocyte volume, stronger cardiac fibrosis, and inflammations (Figure 1). Western blot analysis showed that the phosphorylation of Akt, p-38 MAP kinase, and STAT3 were also up-regulated in SM22α-EKO with control. Phenylephrine - induced vascular contraction was increased and acetylcholine - induced relaxation was impaired in SM22α-EKO. Finally, SM22α-EKO significantly reduced life span in the Kaplan-Meier plot (Figure 2). Conclusion: SM22α-EKO mice revealed spontaneous cardiac dysfunction with the activation of multiple signaling cascades for hypertrophy and inflammation resulting in sudden death. Deletion of ERK2 in heart and smooth muscle cells also led to hypercontraction of phenylephrine / endothelial dysfunction and perivascular cardiac fibrosis and inflammation. SM22α-EKO might be a valuable model for TKI - induced cardiotoxicity.

Introduction: Right ventricular (RV) dysfunction is the strongest predictor of mortality in pulmonary artery hypertension (PAH). Reactive oxygen species in heart failure cause irreversible oxidation of sarcoplasmic reticulum (SR) Ca 2+ -ATPase2 (SERCA2) C674, which results in SERCA2 dysfunction and intracellular Ca 2+ overload. However, the contribution of the loss of the thiol on C674 SERCA2 and RV failure in PAH remains unclear. Hypothesis: The loss of the thiol on C674 SERCA2 contributes to the RV dysfunction in PAH. Methods & Results: We employed the SERCA2 C674S heterozygote knock-in (SKI) mice, in which C674 is replaced by serine, mimics oxidative modification of SERCA2 by loss of the specific thiol. Wild-type mice (WT) and SKI were exposed to either normoxia (Nx) or chronic hypoxia (Hx) for four weeks. Hypoxia elevated RV systolic pressure (WT-Nx: 21.4mmHg vs. WT-Hx: 37.0mmHg, P<0.0001) and represented pulmonary vascular remodeling similarly both in WT and SKI. In histology, SKI-Hx showed the markedly increased Fulton's Index with higher levels of the mRNA expression of atrial natriuretic peptide and B-type natriuretic peptide than WT-Hx. In the exercise test, exercise duration was shorter and peak oxygen consumption was decreased in SKI-Hx than WT Hx. The mRNA levels of SERCA2 were not changed among the four groups. In Ca 2+ transient measurement of isolated myocytes with Fluo-4, SKI prolonged the time to 50% of cytosolic Ca 2+ extrusion (T50) and lower the peak Ca 2+ transient amplitude (F/F0) than WT under Nx. Prolonged T50 and lowered peak F/F0 were observed in WT-Hx, both of which additionally progressed in SKI-Hx. Conclusions: Hypoxia impaired SR Ca 2+ homeostasis in RV. SKI additionally impaired SR Ca 2+ homeostasis with the progression of RV hypertrophy. The loss of the thiol on C674 SERCA2 contributed to the pathogenesis of RV failure in PAH.