Wortmannin, a specific inhibitor of phosphatidylinositol-3-kinase, induces accumulation of DNA double-strand breaks.

Wortmannin, a fungal metabolite, is a specific inhibitor of the phosphatidylinositol 3-kinase (PI3K) family, which includes double-stranded DNA dependent protein kinase (DNA-PK) and ataxia telangiectasia mutated kinase (ATM). We investigated the effects of wortmannin on DNA damage in DNA-PK-deficient cells obtained from severe combined immunodeficient mice (SCID cells). Survival of wortmannin-treated cells decreased in a concentration-dependent manner. After treatment with 50 µM wortmannin, survival decreased to 60% of that of untreated cells. We observed that treatment with 20 and 50 µM wortmannin induced DNA damage equivalent to that by 0.37 and 0.69 Gy, respectively, of γ-ray radiation. The accumulation of DNA double-strand breaks (DSBs) in wortmannin-treated SCID cells was assessed using pulsed-field gel electrophoresis. The maximal accumulation was observed 4 h after treatment. Moreover, the presence of DSBs was confirmed by the ability of nuclear extracts from γ-ray-irradiated SCID cells to produce in vitro phosphorylation of histone H2AX. These results suggest that wortmannin induces cellular toxicity by accumulation of spontaneous DSBs through inhibition of ATM.

Photo-induced antibacterial activity of a porphyrin derivative isolated from the harmful dinoflagellate Heterocapsa circularisquama.

The dinoflagellate Heterocapsa circularisquama is highly toxic to bivalves. However, significant toxicity to finfish species has not been reported. We previously found that H. circularisquama has light-dependent haemolytic agents. Purification and chemical structural analyses revealed that the haemolytic agent H2-a is a porphyrin derivative, which exhibits light-dependent cytotoxicity toward tumour cells. To clarify the biological activity of H2-a further, its antibacterial activities against Gram-positive and Gram-negative bacteria were investigated in this study. A fraction (F5) equivalent to H2-a purified from the methanol extract of H. circularisquama showed potent light-dependent bactericidal activity toward Staphylococcus aureus, and the activity was concentration- and light illumination time-dependent; however, Escherichia coli was highly resistant to F5. Electron microscopic observation suggested that F5 induces morphological changes in S. aureus in a light-dependent manner. Further analysis using other bacterial species showed that the Gram-positive bacterium Bacillus subtilis was more sensitive than the Gram-negative bacteria Pseudomonas aeruginosa and Vibrio alginolyticus. These results indicate that F5 is a photo-induced antibacterial agent with relatively higher specificity to Gram-positive bacteria. Iodometric assay suggested that singlet oxygen was generated from light-illuminated F5. Histidine, a specific singlet oxygen scavenger, markedly inhibited the photosensitising antibacterial activity of F5 against S. aureus, suggesting the involvement of singlet oxygen in antibacterial activity. The antibacterial spectrum of F5 was evidently different from that of 5,10,15,20-tetra (N,N,N-trimethylanilinium) porphyrin tetratosylate, a commercially available porphyrin compound with antibacterial activity. Our results demonstrate that H. circularisquama has a novel antibacterial photosensitiser, a porphyrin derivative, with relatively higher specificity to Gram-positive bacteria. To the best of our knowledge, this is the first study to discover a porphyrin derivative with antibacterial activity in marine microalga.

The effect of ice crystals formations on the flesh quality of frozen horse mackerel (Trachurus japonicus).

It is known that the formation of ice crystals has a negative impact on the flesh quality of frozen meat. This study focuses on how the formation of ice crystals in the dorsal ordinary muscle affects the flesh quality of frozen horse mackerel (Trachurus japonicus). Freeze-thawed muscle specimens (F-TMS) of horse mackerel were first stored at -24C and then thawed. The K-value, expressible water, breaking strength of unfrozen muscle specimens (UMS) and F-TMS, and histological structure (light microscope [LM], scanning electron microscope [SEM] of UMS, frozen muscle specimens [FMS], and F-TMS) were investigated. K-values were higher in the F-TMS than in the UMS, and the increasing rate of K-value in F-TMS was approximately 1.4-fold higher than UMS. Similarly, the percentage of expressible water was higher in the F-TMS than in the UMS. The breaking strength of the UMS decreased with storage period, but it remained at a higher level than that of F-TMS. Numerous ice crystal formations in muscle cells of FMS and small interstices between cells of F-TMS were observed under LM. Moreover, we observed a relatively collapsed honeycomb structure of the extracellular matrix (ECM) under SEM, and found that collagen fibril networks of endomysiums became looser after thawing. Therefore, ice crystals contribute to vulnerabilities in the ECM. These results suggest that a decrease of freshness and the degradation of physical properties caused by ECM destruction may be due to the formation of ice crystals in muscle structures during freezing, leading to the deterioration of flesh quality during storage. PRACTICAL APPLICATIONS: The flesh quality deteriorated after thawing on the basis of degradation of physical properties. Moreover, it could be presumed that the K-value increase was exacerbated by ice crystals, and the decreasing speed of chemical freshness was sped up accompanied by ice storage after thawing. Thus, the formation of ice crystals, which destroyed the muscle cells and structures, may be one of the dominant factors causing the deterioration in the flesh quality.

Evidence for the presence of cell-surface-bound and intracellular bactericidal toxins in the dinoflagellate Heterocapsa circularisquama.

Heterocapsa circularisquama, a harmful dinoflagellate, has multiple haemolytic toxins that are considered to be involved in the toxic mechanism against shellfish and certain species of zooplankton. To evaluate the further nature of the toxins of H. circularisquama, we investigated its effects on several species of bacteria. By colony formation assay, we found that H. circularisquama had antibacterial activity toward the marine bacterium Vibrio alginolyticus in a cell density-dependent manner. When the inoculated bacterial cells were co-cultured with H. circularisquama under dinoflagellate cell culture conditions, the bacterial growth was significantly suppressed, whereas the number of live bacterial cells increased when cultured in the medium alone. Since the cell-free culture supernatant and the ruptured dinoflagellate cell suspension showed no toxic effects on V. alginolyticus, it is speculated that direct cell-to-cell contact mediated by the live dinoflagellate cells may be the major toxic mechanism. The decrease in bactericidal activity of theca-removed dinoflagellate cells may further support this speculation. H. circularisquama also showed bactericidal activities towards Escherichia coli and Staphylococcus aureus. In the dinoflagellate/bacteria co-culture system, the number of live bacterial cells declined with increasing incubation time. Light-dependent antibacterial activity of the ruptured dinoflagellate cells against S. aureus was observed, whereas no such activity was detected against E. coli. These results suggest that intracellular photosensitising bactericidal toxins, which were previously found to be porphyrin derivatives, may have specificity towards gram-positive bacteria. Based on these results together with previous studies, it is obvious that H. circularisquama possesses antibacterial activity, which may be mediated through toxins located on its cell surface. It is likely that such toxins play a role in the defence mechanism against predators and infectious bacteria. Although the exact biological significance of intracellular photosensitising toxins is still unclear, such toxins may have potential to be developed as novel photo-controllable antibiotics.

Effects of alginate oligomer on the expression of cell cycle- and stress-related genes in Chlamydomonas reinhardtii.

Enzymatically prepared alginate oligomer (AO) promoted the growth of Chlamydomonas reinhardtii in a concentration-dependent manner. AO at 2.5 mg/mL induced increase in expression levels of cyclin A, cyclin B, and cyclin D in C. reinhardtii. CuSO4 at 100 µM suppressed the growth of C. reinhardtiin, and AO at 2.5 mg/mL significantly alleviated the toxicity of CuSO4. Increased intracellular reactive oxygen species level in C. reinhardtii induced by CuSO4 was reduced by AO. After cultivation with CuSO4 at 100 µM, expression levels of ascorbate peroxidase and superoxide dismutase in C. reinhardtii were increased, and AO reduced the increased levels of these enzymes. These results suggest that AO exhibits beneficial effects on C. reinhardtii through influencing the expression of various genes not only at normal growth condition but also under CuSO4 stress.

A Prospective Multicenter Study Using a Virtual 3 Fr Percutaneous Coronary Intervention System: The V3 Registry.

OBJECTIVES: To evaluate the safety and feasibility of virtual 3 Fr (V3), sheathless 5 Fr percutaneous coronary intervention (PCI). BACKGROUND: A small-diameter guiding catheter (GC) makes less-invasive PCI possible. The V3 is an extremely slender PCI system; however, the outcome of using this system has not yet been determined. METHODS: The V3 registry is a prospective, multicenter, non-randomized study that enrolled patients who underwent elective V3-PCI. The primary endpoint was clinical success rate, and the secondary endpoints were PCI success rate in all cases, major adverse cardiac and cerebrovascular event (MACCE) at 30 days, and access-site complications. RESULTS: A total of 260 patients with 321 lesions were enrolled. Of this group, 70% were male and the mean age was 70.8 ± 10.0 years. Type B2/C lesions comprised 50.7% of the total. The clinical success rate was 95.8%, and the PCI success rate was 99.2%. PCI failure was reported in 2 chronic total occlusion cases. No MACCE was reported. Although there was no major bleeding, hematoma occurred at the puncture site in 12.7% of cases. There was a single radial artery occlusion (0.4%) without symptoms. CONCLUSIONS: PCI with the V3 was safe and feasible. Radial artery occlusion and major bleeding complications were extremely low. However, access-site hematoma frequently complicated catheter exchange.

Intracellular haemolytic agents of Heterocapsa circularisquama exhibit toxic effects on H. circularisquama cells themselves and suppress both cell-mediated haemolytic activity and toxicity to rotifers (Brachionus plicatilis).

A harmful dinoflagellate, Heterocapsa circularisquama, is highly toxic to shellfish and the zooplankton rotifer Brachionus plicatilis. A previous study found that H. circularisquama has both light-dependent and -independent haemolytic agents, which might be responsible for its toxicity. Detailed analysis of the haemolytic activity of H. circularisquama suggested that light-independent haemolytic activity was mediated mainly through intact cells, whereas light-dependent haemolytic activity was mediated by intracellular agents which can be discharged from ruptured cells. Because H. circularisquama showed similar toxicity to rotifers regardless of the light conditions, and because ultrasonic ruptured H. circularisquama cells showed no significant toxicity to rotifers, it was suggested that live cell-mediated light-independent haemolytic activity is a major factor responsible for the observed toxicity to rotifers. Interestingly, the ultrasonic-ruptured cells of H. circularisquama suppressed their own lethal effect on the rotifers. Analysis of samples of the cell contents (supernatant) and cell fragments (precipitate) prepared from the ruptured H. circularisquama cells indicated that the cell contents contain inhibitors for the light-independent cell-mediated haemolytic activity, toxins affecting H. circularisquama cells themselves, as well as light-dependent haemolytic agents. Ethanol extract prepared from H. circularisquama, which is supposed to contain a porphyrin derivative that displays photosensitising haemolytic activity, showed potent toxicity to Chattonella marina, Chattonella antiqua, and Karenia mikimotoi, as well as to H. circularisquama at the concentration range at which no significant toxicity to rotifers was observed. Analysis on a column of Sephadex LH-20 revealed that light-dependent haemolytic activity and inhibitory activity on cell-mediated light-independent haemolytic activity existed in two separate fractions (f-2 and f-3), suggesting that both activities might be derived from common compounds. Our results suggest that the photosensitising haemolytic toxin discharged from ruptured H. circularisquama cells has a relatively broad spectrum of phytoplankton toxicity, and that physical collapse of H. circularisquama cells can lead not only to the disappearance of its own toxicity, but also to mitigation of the effects of other HABs.

Alginate oligomer induces nitric oxide (NO) production in RAW264.7 cells: elucidation of the underlying intracellular signaling mechanism.

Alginate is an acidic linear polysaccharide with immune-modulating activities. In this study, we found that enzymatically digested alginate oligomer (AO) with various degrees of polymerization (DP; 2-5) induced a higher level of nitric oxide (NO) production in RAW264.7 cells than undigested alginate polymer (AP). Reverse transcription-polymerase chain reaction and western blot analyses revealed that the expression level of inducible NO synthase in AO-treated RAW264.7 cells was higher than that in AP-treated cells. AO induced nuclear translocation of nuclear factor (NF)-κB p65 subunit in RAW264.7 cells to a greater extent than AP. Although AO and AP induced similar extents of phosphorylation in three mitogen-activated protein (MAP) kinases, c-Jun N-terminal kinase inhibitor exhibited the most potent inhibitory effect on NO induction in AO- and AP-treated RAW264.7 cells, among three MAP kinase inhibitors that were tested.

Effects of moderate-to-severe obstructive sleep apnea on the clinical manifestations of plaque vulnerability and the progression of coronary atherosclerosis in patients with acute coronary syndrome.

AIMS: It is unclear whether obstructive sleep apnea (OSA) increases the recurrence of acute coronary syndrome (ACS) in patients with acute myocardial infarction (MI). We hypothesized that moderate-to-severe OSA increased the number of adverse cardiovascular events in patients who underwent primary percutaneous coronary intervention (PCI). METHODS AND RESULTS: This study included 272 patients with acute MI. Polysomnography at first admission determined that 124 patients suffered from moderate-to-severe OSA. The main study outcome measures were cardiac death, recurrence of ACS, and re-admission for heart failure. Major adverse cardiac events (MACEs) were defined as composite end points of individual clinical outcomes. Follow-up coronary angiograms were obtained in 222 patients. PCI-related measures were target vessel revascularization and newly necessitated PCI for progressive lesions. The moderate-to-severe OSA patients had increased ACS recurrence and MACEs compared with patients with mild OSA or without sleep apnea (16% vs. 7%, p = 0.014; 22% vs. 11%, p = 0.014, respectively). PCI for progressive lesions was also higher in the moderate-to-severe OSA patients (28% vs. 15%, p = 0.015). Cox regression analysis showed that moderate-to-severe OSA was an independent predictor of ACS recurrence (hazard ratio = 2.30, p = 0.040). In addition, moderate-to-severe OSA was an independent predictor of PCI for progressive lesions, with a hazard ratio of 2.38 (p = 0.015). CONCLUSIONS: Moderate-to-severe OSA increased the risk of ACS and the incidence of PCI for progressive lesions. Increased plaque vulnerability might be related to these clinical manifestations.

Modified mother-child technique using a buddy wire.

For percutaneous coronary intervention, 6 Fr guiding catheters are the current standard. However, when treating complex coronary lesions, stent delivery is sometimes difficult with a 6 Fr system because of limited back-up support. Several strategies have been proposed in order to overcome this disadvantage, including active/passive guiding- catheter support, wire support, and the anchor-balloon technique. The 4-in-6 mother-child technique is one of the most effective techniques to deliver stents into complex lesions. In the present study, we introduced a new technique in which a second guidewire was used as a buddy wire in combination with the 4 Fr mother-child technique in a case in which stent delivery via the standard 4-in-6 technique failed.

Comparison of frequency of radial artery occlusion after 4Fr versus 6Fr transradial coronary intervention (from the Novel Angioplasty USIng Coronary Accessor Trial).

The frequency of radial artery occlusion was compared between patients receiving 4Fr versus 6Fr transradial coronary interventions (TRIs) in an open-label randomized trial (ClinicalTrials.gov identifier: NCT00815997). The primary outcome measure was radial artery occlusion on the day after TRI. The secondary outcome measures were the procedural success, major advanced cardiac events, access site-related complications, procedural times, fluoroscopy times, and contrast dye usage. A total of 160 patients were included. The procedure was successful in 79 of 80 patients (99%) in both groups. Whereas the 4Fr group showed no access site-related complications, the 6Fr developed 5 (6%), including 3 radial artery occlusions and 2 bleedings (1 radial artery perforation and 1 massive hematoma; p = 0.02). Although the radial artery occlusion rate was lower in the 4Fr versus the 6Fr groups, the difference was not significant (0% vs 4%, p = 0.08). The mean hemostasis time was significantly shorter in the 4Fr than in the 6Fr groups (237 ± 105 vs 320 ± 238 minutes, p = 0.007). In conclusion, these findings suggest that 4Fr TRI may become a less invasive alternative to 6Fr TRI in treating coronary artery diseases.

Heat exposure enhances radiosensitivity by depressing DNA-PK kinase activity during double strand break repair.

PURPOSE: From the role of double strand DNA dependent protein kinase (DNA-PKcs) activity of non-homologous end joining (NHEJ) repair for DNA double strand breaks (DSBs), we aim to define possible associations between thermo-sensitisation and the enzyme activities in X-ray irradiated cells. MATERIALS AND METHODS: DNA-PKcs deficient mouse, Chinese hamster and human cultured cells were compared to the parental wild-type cells. The radiosensitivities, the number of DSBs and DNA-PKcs activities after heat-treatment were measured. RESULTS: Both DNA-PKcs deficient cells and the wild-type cells showed increased radiosensitivities after heat-treatment. The wild-type cells have two repair processes; fast repair and slow repair. In contrast, DNA-PKcs deficient cells have only the slow repair process. The fast repair component apparently disappeared by heat-treatment in the wild-type cells. In both cell types, additional heat exposure enhanced radiosensitivities. Although DNA-PKcs activity was depressed by heat, the inactivated DNA-PKcs activity recovered during an incubation at 37 °C. DSB repair efficiency was dependent on the reactivation of DNA-PKcs activity. CONCLUSION: It was suggested that NHEJ is the major process used to repair X-ray-induced DSBs and utilises DNA-PKcs activity, but homologous recombination repair provides additional secondary levels of DSB repair. The thermo-sensitisation in X-ray-irradiated cells depends on the inhibition of NHEJ repair through the depression of DNA-PKcs activities.

Activity of Aristolochia bracteolata against Moraxella catarrhalis.

A bioassay-guided fractionation of methanol extract of Aristolochia bracteolata whole plant was carried out in order to evaluate its antimicrobial activity and to identify the active compounds in this extract. Antibacterial and antifungal activities of methanol extract against gram-positive, gram-negative, and fungal strains were investigated by the agar disk diffusion method. Among the strains tested, Moraxella catarrhalis and sea urchin-derived Bacillus sp. showed the highest sensitivity towards the methanol extract and hence they are used as test organisms for the bioassay-guided fractionation. From this extract, aristolochic acid 1 (AA-1) has been isolated and has showed the greatest antibacterial activity against both standard strain and clinical isolates of Moraxella catarrhalis with equal minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 25 and 50 µg/mL. Modification of the AA-1 to AA-1 methyl ester completely abolished the antibacterial activity of the compound and the piperonylic acid moiety of AA-1 which suggested that the coexistence of phenanthrene ring and free carboxylic acid is essential for AA-1 antibacterial activity.

Co-existence of carotid artery disease, renal artery stenosis, and lower extremity peripheral arterial disease in patients with coronary artery disease.

In atherosclerosis, carotid artery stenosis (CAS), renal artery stenosis (RAS), lower extremity peripheral arterial disease (PAD), and coronary artery disease (CAD) are common pathologic lesions; their interrelationship is, however, unclear. We studied concomitant multiple atherosclerotic lesions in patients with CAD to understand their prevalence and relations. A cross-sectional analysis was performed on data from consecutive patients who underwent nonemergent coronary angiography. Simultaneous carotid and renal artery Doppler studies and ankle-brachial systolic pressure measurements were reviewed to diagnose concomitant lesions and their severity. The study included 1,734 patients (aged 71 ± 9 years; 70% men), with prevalences of CAS, RAS, lower extremity PAD, and CAD of 6%, 7%, 13%, and 72%, respectively. In patients with CAD (n = 1,253), the prevalences of CAS, RAS, and lower extremity PAD were 7%, 9%, and 16%, respectively; 24% CAD patients had ≥1 additional atherosclerotic lesion. Significant interactions among the prevalences of these lesions were found. In addition, the extent of CAD and the prevalences of CAS, RAS, and lower extremity PAD were significantly correlated. Multivariate analysis supported these relationships. In conclusion, the prevalences of CAS, RAS, lower extremity PAD, and CAD were strongly interrelated in the study population; CAD severity was related to that of other atherosclerotic lesions. Additional systematic screening of other concomitant atherosclerotic lesions is recommended, especially in CAD patients having multivessel disease, left main disease, and/or already diagnosed with other concomitant atherosclerotic lesions.

In vitro thermal effects on embryonic cells of endangered hawksbill turtle Eretmochelys imbricata.

The hawksbill turtle is an ectotherm, whose sex is determined by temperature during embryonic development. This study aimed to determine whether embryonic hawksbill turtle cells respond differently to temperature than mammalian cells. Embryonic hawksbill turtle cells were established in culture, and thermal effects on these cells were investigated in vitro. Cells were maintained in Dulbecco's Modified Eagle Medium supplemented with non-essential amino acids, vitamin solution, sodium pyruvate, and 10% fetal bovine serum at 33°C and cell proliferation occurred at 25-33°C. When cells were incubated at 37°C (the temperature of mammalian cell culture) for 24 h, cell growth was completely inhibited. This growth inhibition was evidently recovered by changing the incubation temperature back to 33°C. Expression of heat shock protein was found to increase with elevating culture temperature from 25 to 33°C.

The 4-in-5 mother-child technique: 5 Fr transradial coronary intervention for complex lesions using a 4 Fr child catheter.

Small 5 Fr guiding catheters are now used in percutaneous coronary intervention (PCI). However, when treating severely calcified and/or tortuous complex coronary lesions, the back-up support of a 5 Fr guiding catheter is often insufficient. We previously developed a 4 Fr child catheter (Kiwami ST-01; Terumo Corporation) and proposed a 4 Fr double-coaxial technique ("mother-child" configuration) to facilitate stent implantation in treating complex coronary lesions. In this manuscript, we report 2 cases of 5 Fr transradial coronary intervention in which stent delivery failed with conventional techniques. In these 2 cases, our 4 Fr double-coaxial technique was employed, and stents were successfully delivered to the target lesions. To the best of our knowledge, this is the first report demonstrating the potential of the 4-in-5 technique during 5 Fr PCI.

Comparison of short- and long-term outcomes of percutaneous coronary intervention for chronic total occlusions between patients aged ≥75 years and those aged <75 years.

Few reports are available on the safety and efficacy of percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) in older patients. In the present study, 284 patients who underwent PCI for CTOs were retrospectively evaluated by comparing the characteristics of 67 patients aged ≥75 years (the older group) and 217 patients aged <75 years (the younger group). Technical success was achieved in 77% of the patients in the older group and 79% of those in the younger group (p = 0.66). No significant differences were observed between the 2 groups in terms of the incidence of procedural complications. In the older group, a comparison between the patients with successful and failed PCI revealed significantly superior 3-year cardiac survival (97.6% vs 76.9%, p = 0.005). The 3-year cardiac survival of those with successful PCI was similar to that observed in the younger group. On multivariate analysis, successful PCI was found to be associated with a lower incidence of cardiac death in the older group (hazard ratio 0.09, 95% confidence interval 0.01 to 0.91, p = 0.042). In conclusion, this single-center, observational study suggests that PCI for CTOs can be performed with a high rate of procedural success and acceptably low mortality and morbidity in older patients, resulting in improved cardiac survival. Thus, PCI for CTO lesions should be included among the treatment strategies for older patients.

Risk of long-term dual antiplatelet therapy following drug-eluting stent implantation in octogenarians.

OBJECTIVES: To evaluate the risk of long-term dual antiplatelet therapy (DAT) following drug-eluting stent (DES) implantation in octogenarians. BACKGROUND: DES implantation requires DAT; however, DAT-associated risk in octogenarians remains unclear. METHODS: Two-hundred and six consecutive octogenarians (130 men, 83.3 ± 3.4 years) underwent stent implantation (104 bare metal stents [BMSs] and 102 DESs) and 38.0 ± 13.2 months of follow-up. RESULTS: Significantly more DES patients received DAT. The incidence of bleeding events was similar in the DES and BMS groups for 1 year (total: 10.8% vs 5.8%, P = 0.19; major: 4.9% vs 2.9%, P = 0.70). However, after 2 years, significantly more bleeding events occurred in the DES group than the BMS group (total: 2 years, 21.6% vs 9.6%, P = 0.02; 3 years, 29.4% vs 11.5%, P = 0.001; 4 years, 31.4% vs 15.4%, P = 0.007; major: 2 years, 12.7% vs 3.8%, P = 0.04; 3 years, 18.6% vs 5.8%, P = 0.005; 4 years, 19.6% vs 6.7%, P = 0.006). Overall, significantly more total bleeding events (31.4% vs 15.4%, P = 0.007) and major bleeding events (19.2% vs 6.7%, P = 0.006) were observed in the DES group than in the BMS group. The adjusted hazard ratios and 95% confidence intervals (CI) were as follows: total bleeding events, 2.203 (95% CI: 1.065-4.556; P = 0.033); major bleeding events, 4.324 (1.506-12.414; P = 0.007). CONCLUSIONS: DAT was associated with an increased risk of bleeding events in octogenarians after 2 years. DAT discontinuation should be considered for octogenarians 1-year post-DES implantation.

Renal artery intervention using a virtual 4.5-Fr guiding catheter.

A 6.5-Fr guiding catheter (Parent Plus 45, Medikit, Tokyo, Japan), composed of a hydrophilic sheathless guiding catheter and a dilator, has recently been developed for the treatment of renal artery stenosis. Because of its unique sheathless configuration, its outer diameter is comparable to that of a conventional 4.5-Fr introducer sheath, with the inner diameter being close in size to a 6.5-Fr guiding catheter. These features allow this sheathless system to be used as the sole guiding catheter while the arterial damage at the puncture site remains equivalent to that of a 4.5-Fr introducer sheath. We thus call this novel sheathless guiding catheter a virtual 4.5-Fr system. To demonstrate the potential of this virtual 4.5-Fr system, we report a case of renal artery stenosis successfully treated via the transradial route. This virtual 4.5-Fr system may become a viable alternative to conventional guiding catheters, and provide a favorable impact upon vascular access complications and patient morbidity.