Spatial Distribution of Flagellated Microalgae Chlamydomonas reinhardtii in a Quasi-Two-Dimensional Space.

Although the phenomenon of collective order formation by cell-cell interactions in motile cells, microswimmers, has been a topic of interest, most studies have been conducted under conditions of high cell density, where the space occupancy of a cell population relative to the space size ϕ>0.1 (ϕ is the area fraction). We experimentally determined the spatial distribution (SD) of the flagellated unicellular green alga Chlamydomonas reinhardtii at a low cell density (ϕ≈0.01) in a quasi-two-dimensional (thickness equal to cell diameter) restricted space and used the variance-to-mean ratio to investigate the deviation from the random distribution of cells, that is, do cells tend to cluster together or avoid each other? The experimental SD is consistent with that obtained by Monte Carlo simulation, in which only the excluded volume effect (EV effect) due to the finite size of cells is taken into account, indicating that there is no interaction between cells other than the EV effect at a low cell density of ϕ≈0.01. A simple method for fabricating a quasi-two-dimensional space using shim rings was also proposed.

Unique left pulmonary vein isolation in straight common trunk based on longitudinal conduction of left lateral ridge.

BACKGROUND: A left common pulmonary vein (LCPV) is the most common anatomical variation in the pulmonary vein (PV) and often influences strategies of PV isolation for atrial fibrillation (AF). Our objective was to elucidate the electrical properties of the specific shape of LCPV and to apply it to an ablation procedure. METHODS AND RESULTS: We investigated consecutive 12 out of 204 paroxysmal AF patients who had the shape of a straight common trunk in LCPV defined by the formation of a single conduit with parallel cranial and caudal walls after the coalescence of superior and inferior PVs on the distal side. The distance between the top of the bifurcation of LPVs and the level coinciding with the middle of the anterior wall of LCPV (left lateral ridge: LLR) was more than 10 mm in all the patients. The activation pattern of the LLR showed longitudinal conduction without outside connections. All the LCPV except one were successfully isolated without ablating the LLR (C-shape ablation). Only one patient had AF recurrence during the follow-up period. CONCLUSION: The LLR in LCPV with a straight common trunk has longitudinal conduction without outside connections, which permits the isolation of LCPV without ablating LLR.

Oncostatin M is a novel biomarker for coronary artery disease - A possibility as a screening tool of silent myocardial ischemia for diabetes mellitus.

OBJECTIVE: Oncostatin M (OSM) is an inflammatory cytokine of the interleukin-6 family which plays a crucial role in the pathogenesis of atherosclerosis. Therefore, we tested our hypothesis that serum OSM levels are increased in patients with coronary artery diseases (CAD). METHODS AND RESULTS: Serum OSM level was measured by sandwich technique immunoassay in 315 consecutive patients and who underwent coronary angiography at the International University of Health and Welfare Hospital from April 2019 to March 2021. A diagnosis of CAD was made in 169 patients. Serum OSM levels were significantly higher in patients with significant coronary stenosis compared to those without it. [123.0 ± 46.7 pg/mL (n = 169) vs. 98.3 ± 47.9 pg/mL (n = 146), p < 0.001]. A positive correlation was noted between serum OSM levels and severity and complexity of coronary stenosis. Importantly, the coronary revascularization significantly decreased the serum OSM levels. We furthermore detected a positive correlation between serum OSM levels and HbA1c levels. Finally, our data suggested that 120 pg/mL of serum OSM was the potential cutoff value for screening of silent myocardial ischemia related with diabetic mellitus (DM). CONCLUSION: Serum OSM can be a novel biomarker for CAD and may be useful for the screening of asymptomatic CAD in patients with DM.

Risk factors and localization of silent cerebral infarction in patients with atrial fibrillation.

BACKGROUND: It is important to identify the risk factors and localization of silent cerebral infarction (SCI), especially in younger patients with atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to examine the characteristics and risk factors for SCI in AF patients, with particular attention to localization of SCI. METHODS: The study enrolled 286 consecutive neurologically asymptomatic patients who underwent AF ablation from January 2014 to July 2017 (age 61.7 ± 10.2 [SD] years; 208 male and 78 female). All patients underwent magnetic resonance imaging (MRI) before ablation. RESULTS: SCIs were classified independently by 2 radiologists as follows: cardiogenic SCI in 19 (10.6%), lacunar SCI in 13 (8.9%), undetermined causes in 6 (1.6%), and no SCI in 248 (controls, 78.7%). Importantly, no patients with CHA2DS2-VASc score 0 had SCI on MRI. In univariable analysis, significant risk factors for lacunar SCI included age (P = .007), hypertension (P = .037), congestive heart failure (P = .040), left atrial (LA) diameter (P = .013), and cardio-ankle vascular index (P = .004). In multivariable analysis, significant risk factors for cardiogenic SCI were AF duration (odds ratio [OR] 1.01; 95% confidence interval [CI] 1.00-1.02; P = .038), ankle-brachial pressure index (OR 0.002; 95% CI 0-0.68; P = .030), and LA abnormality (OR 8.99; 95% CI 2.78-31.00; P <.001), defined by the presence of spontaneous echo contrast and/or decreased LA appendage emptying velocity. CONCLUSION: The study results indicate that among AF patients, SCIs localized in the cerebral cortex and cerebellum are frequently noted, for which cardiogenic mechanisms may be mainly involved; CHA2DS2-VASc score could be useful for screening SCI; and LA abnormality is the specific marker for cardiogenic SCI, providing useful information for risk stratification of SCI.

Low-Intensity Pulsed Ultrasound Enhances Angiogenesis and Ameliorates Left Ventricular Dysfunction in a Mouse Model of Acute Myocardial Infarction.

OBJECTIVE: Left ventricular (LV) remodeling after acute myocardial infarction still remains an important issue in cardiovascular medicine. We have recently demonstrated that low-intensity pulsed ultrasound (LIPUS) therapy improves myocardial ischemia in a pig model of chronic myocardial ischemia through enhanced myocardial angiogenesis. In the present study, we aimed to demonstrate whether LIPUS also ameliorates LV remodeling after acute myocardial infarction and if so, to elucidate the underlying molecular mechanisms involved in the beneficial effects of LIPUS. APPROACH AND RESULTS: We examined the effects of LIPUS on LV remodeling in a mouse model of acute myocardial infarction, where the heart was treated with either LIPUS or no-LIPUS 3 times in the first week (days 1, 3, and 5). The LIPUS improved mortality and ameliorated post-myocardial infarction LV remodeling in mice. The LIPUS upregulated the expression of vascular endothelial growth factor, endothelial nitric oxide synthase, phosphorylated ERK, and phosphorylated Akt in the infarcted area early after acute myocardial infarction, leading to enhanced angiogenesis. Microarray analysis in cultured human endothelial cells showed that a total of 1050 genes, including those of the vascular endothelial growth factor signaling and focal adhesion pathways, were significantly altered by the LIPUS. Knockdown with small interfering RNA of either ß1-integrin or caveolin-1, both of which are known to play key roles in mechanotransduction, suppressed the LIPUS-induced upregulation of vascular endothelial growth factor. Finally, in caveolin-1-deficient mice, the beneficial effects of LIPUS on mortality and post-myocardial infarction LV remodeling were absent. CONCLUSIONS: These results indicate that the LIPUS therapy ameliorates post-myocardial infarction LV remodeling in mice in vivo, for which mechanotransduction and its downstream pathways may be involved.

Low-intensity pulsed ultrasound induces angiogenesis and ameliorates left ventricular dysfunction in a porcine model of chronic myocardial ischemia.

BACKGROUND: Although a significant progress has been made in the management of ischemic heart disease (IHD), the number of severe IHD patients is increasing. Thus, it is crucial to develop new, non-invasive therapeutic strategies. In the present study, we aimed to develop low-intensity pulsed ultrasound (LIPUS) therapy for the treatment of IHD. METHODS AND RESULTS: We first confirmed that in cultured human endothelial cells, LIPUS significantly up-regulated mRNA expression of vascular endothelial growth factor (VEGF) with a peak at 32-cycle (P<0.05). Then, we examined the in vivo effects of LIPUS in a porcine model of chronic myocardial ischemia with reduced left ventricular ejection fraction (LVEF) (n = 28). The heart was treated with either sham (n = 14) or LIPUS (32-cycle with 193 mW/cm2 for 20 min, n = 14) at 3 different short axis levels. Four weeks after the treatment, LVEF was significantly improved in the LIPUS group (46±4 to 57±5%, P<0.05) without any adverse effects, whereas it remained unchanged in the sham group (46±5 to 47±6%, P = 0.33). Capillary density in the ischemic region was significantly increased in the LIPUS group compared with the control group (1084±175 vs. 858±151/mm2, P<0.05). Regional myocardial blood flow was also significantly improved in the LIPUS group (0.78±0.2 to 1.39±0.4 ml/min/g, P<0.05), but not in the control group (0.84±0.3 to 0.97±0.4 ml/min/g). Western blot analysis showed that VEGF, eNOS and bFGF were all significantly up-regulated only in the LIPUS group. CONCLUSIONS: These results suggest that the LIPUS therapy is promising as a new, non-invasive therapy for IHD.

Involvement of rho-kinase activation in the pathogenesis of coronary hyperconstricting responses induced by drug-eluting stents in patients with coronary artery disease.

BACKGROUND: Activation of Rho-kinase plays a central role in the pathogenesis of drug-eluting stents (DES)-induced coronary hyperconstricting responses in pigs in vivo has been previously demonstrated. In the present study, Rho-kinase activation involved in those responses in patients with coronary artery disease (CAD) is examined. METHODS AND RESULTS: In 24 patients with CAD who underwent coronary intervention with either DES or bare-metal stents (BMS), coronary vasomotor responses to intracoronary acetylcholine (ACh) before and after intracoronary pre-treatment with a Rho-kinase inhibitor, fasudil was examined. Coronary vasomotor responses by quantitative coronary angiography (QCA) and coronary vascular structure by optical coherence tomography (OCT) was evaluated. QCA showed that the coronary vasoconstricting responses to ACh were significantly enhanced in the DES group compared with the BMS group both at the proximal and the distal segments adjacent to the stents (proximal: BMS -13.0±10.7% vs. DES -25.4±14.3%, P=0.036; distal: BMS -24.4±12.2% vs. DES -43.8±14.7%, P=0.003). Importantly, fasudil markedly attenuated the enhanced vasoconstricting responses to ACh in the DES group (proximal 10.2±11.7%, distal 14.4±10.5% vs. before fasudil, both P<0.01). In the OCT imaging analysis, there was no significant correlation between intimal thickness and coronary vasoconstriction to ACh. CONCLUSIONS: These results indicate that Rho-kinase activation is substantially involved in the pathogenesis of the DES-induced coronary hyperconstricting responses in patients with CAD, suggesting the therapeutic importance of Rho-kinase pathway.

Long-term treatment with nifedipine suppresses coronary hyperconstricting responses and inflammatory changes induced by paclitaxel-eluting stent in pigs in vivo: possible involvement of Rho-kinase pathway.

AIMS: Accumulating evidence indicates that coronary vasoconstricting responses are enhanced at the edges of coronary segment implanted with a drug-eluting stent (DES) compared with a bare-metal stent (BMS) in humans. We have recently demonstrated that Rho-kinase pathway plays an important role in DES-induced coronary hyperconstricting responses associated with inflammatory changes in pigs in vivo. This study examined whether long-term treatment with calcium channel blocker suppresses DES-induced coronary hyperconstricting responses in pigs in vivo. METHODS AND RESULTS: Paclitaxel-eluting stent (PES) and a BMS were randomly implanted in the left coronary arteries in male domestic pigs with and without long-acting nifedipine (NIF, 4 mg/kg/day) for 4 weeks (n = 7 each). Coronary vasomotion was evaluated by quantitative coronary angiography at least 24 h after withdrawal of NIF to avoid its direct effects on coronary vasomotion. In the control group (without NIF), coronary vasoconstricting responses to serotonin (10 and 100 µg/kg, i.c.) were significantly enhanced at the PES site compared with the BMS site (P = 0.009), which were abolished by hydroxyfasudil (90 and 300 µg/kg, i.c.), a selective Rho-kinase inhibitor. The PES-induced vasoconstricting responses were significantly inhibited in the NIF group (P = 0.019). Histological examination showed that inflammatory cell accumulation and microthrombus formation were enhanced at the PES site compared with the BMS site (P < 0.05), both of which were significantly suppressed by NIF associated with reduced Rho-kinase expression and activity (P < 0.05). CONCLUSION: These results indicate that long-term treatment with NIF suppresses PES-induced coronary abnormalities partly through Rho-kinase pathway inhibition in vivo.

Enhanced Rho-kinase activity in circulating neutrophils of patients with vasospastic angina: a possible biomarker for diagnosis and disease activity assessment.

OBJECTIVES: The aim of this study was to examine whether Rho-kinase activity is systemically enhanced in patients with vasospastic angina (VSA) and, if so, whether a noninvasive diagnostic method could be developed to improve practice. BACKGROUND: The activated Rho-kinase pathway plays a central role in the molecular mechanism of coronary vasospasm in animal models and patients with VSA. Recently, it has been reported that Rho-kinase activity in circulating leukocytes is associated with various diseases. METHODS: Fifty-three consecutive patients with chest pain who underwent acetylcholine provocation testing for coronary spasm were examined. Patients were divided into 2 groups depending on their response to the test: VSA (n = 33) and non-VSA (n = 20) groups. Venous blood samples were collected to measure Rho-kinase activity in circulating neutrophils, determined by the extent of phosphorylation of myosin-binding subunit (MBS), a substrate of Rho-kinase. RESULTS: Rho-kinase activity was significantly higher in the VSA group than in the non-VSA group (phosphorylated MBS/total MBS ratio 1.33 ± 0.37 vs. 0.95 ± 0.22, p < 0.001). In the VSA group, no correlation was noted between Rho-kinase activity and high-sensitivity C-reactive protein, smoking, or accumulated number of coronary risk factors. After the 3-month medical treatment, Rho-kinase activity in the VSA group was significantly decreased to 1.08 ± 0.31 (p < 0.001). On receiver-operating characteristic curve analysis, a phosphorylated MBS ratio of 1.18 was identified as the best cutoff level to predict the diagnosis of VSA. CONCLUSIONS: These results indicate that Rho-kinase activity in circulating neutrophils is enhanced in patients with VSA and may be a useful biomarker for diagnosis and disease activity assessment of the vasospastic disorder.

Long-term treatment with eicosapentaenoic acid ameliorates myocardial ischemia-reperfusion injury in pigs in vivo. -Involvement of Rho-kinase pathway inhibition-.

BACKGROUND: Eicosapentaenoic acid (EPA), the major n-3 fatty acid in fish oil, exerts cardioprotective effects against ischemic heart disease; however, the detailed mechanisms remain to be elucidated. Rho-kinase plays an important role in the pathogenesis of cardiovascular diseases including ischemia-reperfusion (I/R) injury. Thus, the hypothesis that long-term EPA treatment ameliorates myocardial I/R injury through Rho-kinase pathway inhibition in pigs in vivo was investigated. METHODS AND RESULTS: Male pigs were treated with either a control chow or EPA (600·mg·kg⁻¹·day⁻¹) for 3 weeks (n=8 each) and were subjected to myocardial ischemia by 90-min occlusion of the left circumflex coronary artery and subsequent 60-min reperfusion. The EPA group had an increased EPA level in red blood cells (4.4 ± 0.3mol%). The EPA treatment significantly ameliorated myocardial I/R injury, including regional wall motion abnormality (EPA 5.3 ± 3.6 vs. control 35.1 ± 3.8 unit, P<0.0001), left ventricular ejection fraction (EPA 43 ± 9% vs. control 32 ± 7%, P<0.05), occurrence of ventricular arrhythmias (EPA 181 ± 73 vs. control 389 ± 51 events, P<0.0001) and histological accumulation of inflammatory cells (P<0.01). Importantly, the EPA treatment significantly inhibited myocardial Rho-kinase activity (assessed by the extent of the myosin-binding subunit phosphorylation) (EPA 0.47 ± 0.11 vs. control 0.77 ± 0.14, P<0.05) and preserved myocardial eNOS activity (EPA 0.56 ± 0.13 vs. control 0.23 ± 0.07, P<0.01) with a significant correlation noted between them. CONCLUSIONS: Long-term treatment with EPA ameliorates I/R injury partly through Rho-kinase pathway inhibition in vivo.

Double-blind and placebo-controlled study of the effectiveness and safety of extracorporeal cardiac shock wave therapy for severe angina pectoris.

BACKGROUND: Low-energy shock wave (SW) therapy has improved myocardial ischemia in both a porcine model and in patients with severe angina pectoris. METHODS AND RESULTS: To further confirm the effectiveness and safety of SW therapy, 8 patients with severe angina pectoris were treated with SW therapy in a double-blind, placebo-controlled and cross-over manner. SW therapy, but not placebo, significantly improved chest pain symptoms and cardiac function without any complications or adverse effects. CONCLUSIONS: Extracorporeal cardiac SW therapy is an effective, safe and non-invasive therapeutic option for severe angina pectoris.