Perylene-Cy3 FRET System to Analyze Photoactive DNA Structures.

We report a new Förster resonance energy transfer (FRET) system for structural analyses of DNA duplexes using perylene and Cy3 as donor and acceptor, respectively, linked at the termini of a DNA duplex via D-threoninol. Experimentally obtained FRET efficiencies were in good agreement with theoretical values calculated based on canonical B-form DNA. Due to the relatively long Förster radius, this system can be used to analyze large DNA structures, and duplexes containing photo-reactive molecules can be analyzed since perylene can be excited with visible light.

Visible-Light-Triggered Cross-Linking of DNA Duplexes by Reversible [2+2] Photocycloaddition of Styrylpyrene.

Reversible photo-cross-linking of a DNA duplex through the [2+2] photocycloaddition of styrylpyrene is reported. Styrylpyrene moieties on d-threoninol linkers were introduced into complementary positions on DNA strands. Irradiation of the styrylpyrene pair in the duplex with visible light at λ=455 nm induced a [2+2] photocycloaddition between styrylpyrenes that cross-linked the two strands of the duplex.

Terminus-free siRNA prepared by photo-crosslinking activated via slicing by Ago2.

We report the development of photo-crosslinked siRNA strands modified at each terminus with p-cyanostilbene. The siRNA was nuclease resistant and retained RNAi activity. We further studied the activation mechanism of the covalently-crosslinked siRNA.

Hetero-Selective DNA-Like Duplex Stabilized by Donor-Acceptor Interactions.

We report on the characterization of a novel hetero-selective DNA-like duplex of pyrene and anthraquinone pseudo base pairs. The pyrene/anthraquinone pairs showed excellent selectivity in hetero-recognition and even trimers were found to form a hetero-duplex. Pyrene and anthraquinone moieties were tethered on acyclic D-threoninol linkers and linked to adjacent residues by using standard phosphoramidite chemistry.

Efficiency of [2 + 2] photodimerization of various stilbene derivatives within the DNA duplex scaffold.

A DNA duplex was used as a scaffold to evaluate the intrinsic reactivity of [2 + 2] photodimerization between stilbene derivatives; the duplex pre-organizes the substrates avoiding the need for an association step. Unmodified stilbenes were first introduced at base-pairing positions on complementary DNA strands. The duplex was then irradiated with 340 nm UV light.

p-Stilbazole moieties as artificial base pairs for photo-cross-linking of DNA duplex.

In this study, we report a photo-cross-linking reaction between p-stilbazole moieties. p-Stilbazoles were introduced into base-paring positions of complementary DNA strands. The [2 + 2] photocycloaddition reaction occurred rapidly upon light irradiation at 340 nm.

Assessment of a novel stentless mitral valve using a pulsatile mitral valve simulator.

Background And Aim Of The Study: The study aim was to develop a novel stentless mitral valve (SMV) and to evaluate its performance, using an original pulsatile simulator developed specifically to analyze the hydrodynamic function of the mitral valve.

Methods: The SMV developed at the authors' institution consists of two major components: a large anterior leaflet with commissures, and a small posterior leaflet. The valve is formed by suturing the leaflets (made from bovine pericardium) to a flexible (Duran) ring.

Chronic total occlusion of the left main coronary artery with normal left ventricular motion: the occluded site confirmed by three-dimensional computed tomography.

Total occlusion of the left main trunk (LMT) frequently results in sudden cardiac death. As a result, it is rarely observed on coronary arteriogram. There are only a few reports on chronic total occlusion of the LMT.

Late thrombosis of a drug-eluting stent overlapped in the in-stent restenotic lesion of a bare metal stent.

Late stent thrombosis occurred in the lesion of a sirolimus-eluting stent implanted 6 months previously for an in-stent restenosis lesion in the distal right coronary artery. Seventeen days before admission due to acute myocardial infarction this time, aspirin was discontinued for colon polypectomy. Ticlopidine had been discontinued 3 months before the discontinuation of aspirin.

Oozing type of left ventricular rupture via subepicardial aneurysm diagnosed 5 months after myocardial infarction.

A 71-year-old man visited our hospital complaining of increasing fatigue and exertional dyspnea. He had had severe epigastric pain for the past 5 months. On admission, chest radiogram showed marked cardiac dilatation and echocardiogram massive pericardial effusion with a small subepicardial aneurysm at the posterior wall of the left ventricle.

Systolic anterior motion (SAM) of the posterior mitral leaflet: left ventricular outflow tract obstruction in a patient without left ventricular hypertrophy.

Systolic anterior motion (SAM) of the anterior mitral leaflet with mitral-septal contact was generally thought to be a major contributor to dynamic left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy. We report an interesting case of SAM of the posterior mitral leaflet in a patient without left ventricular hypertrophy, which led to dynamic left ventricular obstruction.