Cardiovascular risk factors are associated with augmented thrombogenicity in healthy individuals: analysis using the Total Thrombus-formation Analysis System.

BACKGROUND: Rupture of an atherosclerotic plaque and subsequent exposure of the subendothelial prothrombotic matrix to blood cause arterial thrombosis. Circulating platelets play an indispensable role in the growth of arterial thrombi partially owing to their unique ability to adhere to the subendothelial matrix and to aggregate to each other under flow conditions. Recently, the Total Thrombus-formation Analysis System (T-TAS) was developed for ex vivo analysis of the thrombogenic potential of whole blood samples under flow conditions. Despite the potential clinical utility of the T-TAS in assessing the risk for thrombosis and bleeding, reference intervals for T-TAS analysis in healthy individuals have not been determined. METHODS: In total, 122 whole blood samples were collected from healthy volunteers ranging in age from 25 to 45 years. T-TAS analysis and hematological, physiological, and lifestyle assessments were conducted in these subjects. Whole blood samples anticoagulated with hirudin were perfused into a collagen-coated microchip (PL chip). The time to 10 kPa and the area under the flow pressure curve up to 10 min (AUC10) were analyzed as representative variables for thrombogenic potential. Reference intervals, which were defined as 2.5-97.5 percentiles, were determined. Additionally, univariate and multivariate analyses were performed to identify factors associated with the AUC10 in the T-TAS. RESULTS: The time to 10 kPa and the AUC10 widely varied, even in healthy volunteers. The reference intervals were 1.50-4.02 min and 223.4-456.8, respectively, at a shear rate of 1500 s- 1. Univariate and multivariate analyses showed that platelet counts were most significantly associated with the AUC10 of the T-TAS. The presence of one or more cardiovascular risk factors of a high body mass index, a high pulse pressure, high fasting serum glucose levels, high low-density lipoprotein-cholesterol levels, a history of smoking, and no habitual exercise, had the second largest effect on the AUC10 of the T-TAS. CONCLUSIONS: Healthy volunteers who had any cardiovascular risk factors showed augmented thrombogenicity, even in artificial uniform capillaries, compared with those without any risk factors in the T-TAS.

DR396, an apoptotic DNase γ inhibitor, attenuates high mobility group box 1 release from apoptotic cells.

High mobility group box1 (HMGB1) is a non-histone chromatin chromosomal protein playing an important role in chromatin architecture and transcriptional regulation. Recently, HMGB1 has been shown to be secreted into extracellular milieu in necrosis and apoptosis, and involved in inflammatory responses. However, the mechanism by which apoptotic cells release HMGB1 is unclear. In this study, to investigate the mechanism of HMGB1 release, we searched inhibitors of HMGB1 release from apoptotic cells. As a result, three compounds, 4-(4,6-dichloro-[1,3,5]-triazin-2-ylamino)-2-(6-hydroxy-3-oxo-3H-xanthen-9-yl)-benzoic acid (DR396), Pontacyl Violet 6R (PV6R), and Fmoc-D-Cha-OH (FDCO) in our in-house chemical library were found to inhibit HMGB1 release from staurosporine (STS)-induced apoptotic HeLa S3 cells. Interestingly, these three compounds have been previously categorized into apoptotic DNase γ inhibitors. Therefore, we examined whether apoptotic nucleosomal DNA fragmentation is involved in the release of HMGB1 during apoptosis. Expectedly, DR396, which is the most potent and specific inhibitor of DNase γ, was found to almost completely inhibit both HMGB1 release and internucleosomal DNA cleavage in HeLa S3 cells transfected with DNase γ expression vector and stably expressing DNase γ (HeLa S3/γ cells). These results clearly suggest that nucleosomal DNA fragmentation catalyzed by DNase γ is critical in the release of HMGB1 from apoptotic cells.

The release of high mobility group box 1 in apoptosis is triggered by nucleosomal DNA fragmentation.

High mobility group box 1 (HMGB1) initially identified as a non-histone chromosomal protein, which mainly functions as chromatin structure and transcriptional regulation, has been recently reported to be secreted into extracellular milieu in necrosis and apoptosis, and act as a proinflammatory mediator. However, the mechanism by which apoptotic cells release HMGB1 is not clear. In this study, we found that staurosporine (apoptosis-inducer)-induced HMGB1 release was associated with nucleosomal DNA fragmentation catalyzed by caspase-activated DNase (CAD) in WEHI-231 cells. Importantly, this event was effectively attenuated by the treatment of a pan-caspase inhibitor, Z-VAD-fmk, and by the inhibition of CAD-mediated DNA fragmentation by the expression of caspase-resistant inhibitor of CAD (ICAD-CR). In WEHI-231/ICAD-CR and WEHI-231/Puro cells, DNase γ-catalyzed nucleosomal DNA fragmentation occurred by anti-IgM antibody treatment was critical for HMGB1 release. Furthermore, in DNase γ stably-expressing HeLa S3 cells (HeLa S3/γ), the release of HMGB1 accompanied with nucleosomal DNA fragmentation was more apparent than that in parental HeLa S3 cells in which DNA fragmentation was scarcely observed. Taken together, these date suggest that nucleosomal DNA fragmentation catalyzed by CAD or DNase γ plays a pivotal role in HMGB1 release.

Iodine atom transfer [3 + 2] cycloaddition reaction with electron-rich alkenes using N-tosyliodoaziridine derivatives as novel azahomoallyl radical precursors.

Treatment of N-tosyliodoaziridine derivatives with Et(3)B efficiently produces various azahomoallyl radical (2-akenylamidyl radical) species which give oxygen-functionalized pyrrolidine derivatives through iodine atom transfer [3 + 2] cycloaddition with electron-rich alkenes such as enol ethers and ketene acetal. The present cycloaddition reaction proceeds regioselectively via C-N bond cleavage of an aziridinylalkyl radical intermediate and addition of the resulting azahomoallyl radicals to the terminal carbon of an alkene. The reaction of alkenes with the cyclohexenylamidyl radical generated from an optically active bicyclic iodoaziridine [(1S,2S,6S)-2-iodo-7-(p-toluenesulfonyl)-7-azabicyclo[4.1.0]heptane, 94% ee] also proceeds to give optically active octahydroindole derivatives (84-93% ee).

Dysgeusia due to an orthodontic wire: a case report.

A 14-year-old female developed gustatory disorder due to an orthodontic wire having pierced the right trigonal retromolar. The patient's complaints included traction pain on the right lower jaw, numbness on the right front half of the tongue and hypogeusia with the exception of sweet tastes. Possible causes of dysgeusia in this case were: (i) direct mechanical compression of a gustatory nerve by the orthodontic wire; and (ii) disturbance of blood supply to a gustatory nerve by edema that developed in nerve tissues around the wire. The patient's retention of a normal threshold for the recognition of sweet tastes is not fully understood.

Radical cascade reaction with 1,4-dienes and 1,4-enynes using 2-(iodomethyl)cyclopropane-1,1-dicarboxylate as a homoallyl radical precursor: one-step synthesis of bicyclo[3.3.0]octane derivatives.

[reaction: see text] Radical cascade reaction with various 1,4-dienes and 1,4-enynes using dimethyl 2-(iodomethyl)cyclopropane-1,1-dicarboxylate as a homoallyl radical precursor smoothly proceeds through an iodine atom transfer mechanism to give functionalized bicyclo[3.3.0]octane derivatives in good yields.

Radical [3 + 2] cycloaddition reaction with various alkenes using iodomethylcyclopropane derivatives as new homoallyl radical precursors.

Radical iodine atom transfer [3 + 2] cycloaddition with various alkenes using dimethyl 2-(iodomethyl)cyclopropane-1,1-dicarboxylate and 1,1-bis(phenylsulfonyl)-2-(iodomethyl)cyclopropane as new precursors of a homoallyl radical species smoothly proceeds to give functionalized cyclopentane derivatives in good yields.