Visualization of collateral channels with coronary computed tomography angiography for the retrograde approach in percutaneous coronary intervention for chronic total occlusion

[Background] There have been no reports about the diagnostic ability of coronary computed tomography angiography (CTA) in evaluating collateral channels used for retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI). [Objective] We investigated the ability and diagnostic accuracy of coronary CTA compared with invasive coronary angiography to detect collaterals used in retrograde CTO PCI and to compared the success rates for wire crossing between collaterals that are detectable and not detectable in coronary CTA. [Methods] We retrospectively reviewed data from 43 patients (55 collaterals) who underwent coronary CTA and PCI for CTO with the retrograde approach. We compared the ability of coronary CTA to visualize collaterals to invasive coronary angiography and evaluated the rates of successful wire crossing between CTA-visible and invisible collaterals. [Results] The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of coronary CTA for detecting collaterals which were used for the retrograde approach was 100.0%, 50.0%, 65.9%, 100.0%, and 74.5%, respectively. Guidewire collateral crossing was more successful in CT-visible collaterals than those not detectable in CT (74.1% vs. 46.4%, p = 0.034). There were fewer collateral vessel injuries in CTA-visible collaterals (11.1% vs. 32.1%, p = 0.041). [Conclusion] Coronary CTA provides good visualization of collaterals used in retrograde CTO PCI. For retrograde guidewire crossing, a higher success rate with fewer complications was observed in CTA-visible collaterals than in those not detectable in coronary CTA

Architecture of Replication Compartments Formed during Epstein-Barr Virus Lytic Replication

Epstein-Barr virus (EBV) productive DNA replication occurs at discrete sites, called replication compartments, in nuclei. In this study we performed comprehensive analyses of the architecture of the replication compartments. The BZLF1 oriLyt binding proteins showed a fine, diffuse pattern of distribution throughout the nuclei at immediate-early stages of induction and then became associated with the replicating EBV genome in the replication compartments during lytic infection. The BMRF1 polymerase (Pol) processivity factor showed a homogenous, not dot-like, distribution in the replication compartments, which completely coincided with the newly synthesized viral DNA. Inhibition of viral DNA replication with phosphonoacetic acid, a viral DNA Pol inhibitor, eliminated the DNA-bound form of the BMRF1 protein, although the protein was sufficiently expressed in the cells. These observations together with the findings that almost all abundantly expressed BMRF1 proteins existed in the DNA-bound form suggest that the BMRF1 proteins not only act at viral replication forks as Pol processive factors but also widely distribute on newly replicated EBV genomic DNA. In contrast, the BALF5 Pol catalytic protein, the BALF2 single-stranded-DNA binding protein, and the BBLF2/3 protein, a component of the helicase-primase complex, were colocalized as distinct dots distributed within replication compartments, representing viral replication factories. Whereas cellular replication factories are constructed based on nonchromatin nuclear structures and nuclear matrix, viral replication factories were easily solubilized by DNase I treatment. Thus, compared with cellular DNA replication, EBV lytic DNA replication factories would be simpler so that construction of the replication domain would be more relaxed

Lattice Water-Induced Helical Stacking of Tartrate-Bridged Dinuclear Palladium(II) Complexes: The Role of Hydrogen Bonding

Hydrous crystals of [{Pd^II(bpy)}₂(μ-x-tart)]·<i>n</i>H₂O (bpy: 2,2′-bipyridine; tartH₂^2–: tartrate; <b>1a</b>: x = l, <i>n</i> = 6; <b>2a</b>: x = d, <i>n</i> = 6; <b>3a</b>: x = dl, <i>n</i> = 4; <b>4a</b>: x = <i>meso</i>, <i>n</i> = 4) and anhydrous crystals of [{Pd^II(bpy)}₂(μ-l-tart)] (<b>1b</b>) were isolated from aqueous and MeOH solutions, respectively. X-ray crystallography revealed the stacked structures of clamshell-like dinuclear units in <b>1a</b>–<b>3a</b> and <b>1b</b>, where intramolecular metal–metal and π–π stacking interactions were observed. Right- and left-handed helically stacked columns were formed in the <b>1a</b> and <b>2a</b> crystals, respectively. The significant role of hydrogen bonding among lattice water molecules and tartrate is suggested because <b>1b</b> exhibited a zigzag arrangement only through intermolecular metal–metal interactions. In <b>3a</b>, l- and d-tart units stacked alternately in a zigzag arrangement with intermolecular π–π interactions. In <b>4a</b>, dimeric aggregates of the twisted dinuclear units further formed a 2D sheet architecture