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Peripheral stent could fracture from cyclic loadings as a result of our blood pressures or daily activities. Fatigue performance has therefore become a key issue for peripheral stent design. A simple yet powerful tapered-strut design concept for fatigue life enhancement was investigated. This concept is to move the stress concentration away from the crown and re-distribute the stresses along the strut by narrowing the strut geometry. Finite element analysis was performed to evaluate the stent fatigue performance under various conditions consistent with the current clinical practice. Thirty stent prototypes were manufactured in-house by laser with a series of post-laser treatments, followed by the validation of bench fatigue tests for proof of concept. FEA simulation results show that the fatigue safety factor of the 40% tapered-strut design increased by 4.2 times that of a standard counterpart, which was validated by bench tests with 6.6-times and 5.9-times fatigue enhancement at room temperature and body temperature, respectively. Bench fatigue test results agreed very well with the increasing trend predicted by FEA simulation. The effects of the tapered-strut design were significant and could be considered as an option for fatigue optimization of future stent designs. [ABSTRACT FROM AUTHOR]

Eotaxin-2 is a potent chemoattractant. High concentration of eotaxin-2 triggers the inflammation and tumor metastasis. Inhibition of eotaxin-2 may protect experimental atherogenesis although the mechanism is still unclear. Toll-like receptor 4 (TLR4) plays a major role mediating vascular inflammation, which is related to atherogenesis. In the results, we demonstrated that eotaxin-2 potentially impairs the tube formation capacity of human coronary artery endothelial cells (HCAECs). Eotaxin-2 augments the monocytic adhesion in lipopolysaccharides (LPS)-induced HCAECs, and which were reversed by TLR4 siRNA. Thus this study was conducted to investigate whether eotaxin-2 increases TLR4 expression, and then enhances the sensitivity of cells to antigen stimulation in HCAECs, which mediates the increasing of the development of serious atherosclerosis. In fact, we showed that JNK/SAPK, p38 MAPK, and ERK1/2 activation contribute to the transcriptional signaling pathway, JNK/SAPK and p38 MAPK regulate post-transcriptional modification, as well as protein-trafficking pathway in eotaxin-2-treated HCAECs TLR4 expression. RNA binding proteins, such as human antigen R (HuR) and tristetraprolin (TTP) mediate stability of TLR4 mRNA and chaperone, such as PRAT4A (a protein associated with TLR4) regulate trafficking of TLR4 protein might confer eotaxin-2 responsiveness. Eotaxin-2 administration led to a significant elevation of high cholesterol diet-induced atherosclerosis, and of TLR4 expression in B6.129S7- Ldlr tm1Her /J but not Ldlr -/--/-/ Tlr4 -/- mice. Our results revealed that eotaxin-2 induced overexpression TLR4 via mitogen-activated protein kinases (MAPK) signaling pathways, RNA binding proteins-mediated mRNA stabilization, and PRAT4A-regulated trafficking in HCAECs. These effects may lead to amplification of inflammatory responses contribute to the pathogenesis of cardiovascular disorders.

Porphyromonas gingivalis (P. gingivalis) is a bacterial species that causes periodontitis. GroEL from P. gingivalis may possess biological activity and may be involved in the destruction of periodontal tissues. However, it is unclear whether P. gingivalis GroEL enhances the appearance of atherogenic phenomena in endothelial cells and vessels. Here, we constructed recombinant GroEL from P. gingivalis to investigate its effects in human coronary artery endothelial cells (HCAECs) in vitro and on aortas of high-cholesterol (HC)-fed B57BL/6 and B57BL/6-Tlr4(lps-del) mice in vivo. The results showed that GroEL impaired tube-formation capacity under non-cytotoxic conditions in HCAECs. GroEL increased THP-1 cell/HCAEC adhesion by increasing the expression of intracellular adhesion molecule (ICAM)-1 and vascular adhesion molecule (VCAM)-1 in endothelial cells. Additionally, GroEL increased DiI-oxidized low density lipoprotein (oxLDL) uptake, which may be mediated by elevated lectin-like oxLDL receptor (LOX)-1 but not scavenger receptor expressed by endothelial cells (SREC) and scavenger receptor class B1 (SR-B1) expression. Furthermore, GroEL interacts with toll-like receptor 4 (TLR4) and plays a causal role in atherogenesis in HCAECs. Human antigen R (HuR), an RNA-binding protein with a high affinity for the 3' untranslated region (3'UTR) of TLR4 mRNA, contributes to the up-regulation of TLR4 induced by GroEL in HCAECs. In a GroEL animal administration study, GroEL elevated ICAM-1, VCAM-1, LOX-1 and TLR4 expression in the aortas of HC diet-fed wild C57BL/6 but not C57BL/6-Tlr4(lps-del) mice. Taken together, our findings suggest that P. gingivalis GroEL may contribute to cardiovascular disorders by affecting TLR4 expression.

Background: Arterial stiffness is a physiologic quantitative value used to measure arterial compliance. It is predictive of coronary atherosclerosis in patients with intermediate to high cardiovascular risk. However, a correlation between arterial stiffness and subclinical coronary atherosclerosis has yet to be established. Therefore, the purpose of this study was to evaluate arterial stiffness using an arterial stiffness index (ASI) and investigate its association with coronary artery plaque in patients with subclinical coronary atherosclerosis., Methods: Our study enrolled 156 consecutive subjects who underwent health screening using a 64-slice cardiac computed tomography angiography (CCTA). Their arterial stiffness index was assessed noninvasively by CardioVision(®) MS-2000. The atheroma on the coronary vessel walls was analyzed., Results: Of the 156 patients, 53 displayed at least one > 50% stenotic lesion over the coronary arteries in CCTA images. The patients with at least one > 50% coronary stenotic plaque were older and had higher systolic blood pressure and ASI values than patients without > 50% coronary stenotic plaque. After dividing the study population into 2 groups by those patients over and under 50 years of age, the ASI positively correlated with the presentation of at least one > 50% coronary stenotic plaque in patients aged ≥ 50 years (odds ratio = 1.02, 95% confidence interval: 1.00-1.04, p = 0.03)., Conclusions: The ASI could play a role in risk stratification systems for coronary artery disease in patients with subclinical coronary atherosclerosis, and is a useful clinical marker for the correlation of early coronary plaque., Key Words: Arterial stiffness; Arterial stiffness index; Atherosclerosis; Coronary artery plaque.

Background: Sudden death is a rare but real threat to hospital-based physicians and surgeons. The association between sudden death and blood pressure (BP) fluctuations in healthcare providers has not been documented. We hypothesized that work-shift loading may lead to variable BP surges in hospital-based healthcare staff, which might contribute to their development of cardiovascular disease., Methods: Our intention is to ask 150 healthcare staff (doctors, medical technicians, and nurses) working in the coronary catheterization lab, intensive care unit, and the medical wards, respectively, to volunteer for the study. Their changes in BP would automatically be recorded every 60 minutes on an ambulatory BP monitoring machine for 24 hours during a normal workday. All events and activities would be recorded in a diary, which would allow us to coordinate BP changes with the work being done during the shift. All cardiovascular outcomes would be followed-up for a five-year duration., Conclusions: We herein report the rationale and design of this first multicenter trial in Taiwan to explore the BP behavior associated with long work shifts in healthy hospital-based healthcare providers., Key Words: Ambulatory blood pressure; Health-care staff; Occupation; Work shift.

Background: The implantation of a pacemaker is frequently a life-saving procedure. However, the process of implantation may carry an uncommon but potentially life-threatening infective complication. The prescription of prophylactic antibiotics is an effective way to reduce the risk of infection. The aim of the present study was to investigate the efficacy of 2 prophylactic antibiotic schemes and the possible risk factors associated with device-related infections., Methods: A total of 194 consecutive patients who received permanent pacemaker (PPM) implantations were enrolled in this study. Prophylactic antibiotics were prescribed for every patient with a duration of either 1 day or 3 days. The follow-up period was 3 months, and any event of device-related infection was recorded., Results: Out of the total 194 patients, there were 5 patients who experienced infective complications after PPM implantation (1 patient in the 1-day group and 4 patients in the 3-day group). The rate of infective complications showed no significant difference between the 2 kinds of antibiotic regimens (1.7% vs. 2.9%, p > 0.99). In the multivariate analysis, only the presence of pocket hematoma was an independent risk factor for infective complications (odds ratio = 3.14, p = 0.018)., Conclusions: Our study showed that the efficacies for prevention of PPM-related infections were similar between the 1-day and 3-day regimens of prophylactic antibiotics. Pocket hematoma was an independent risk factor of infective complications, and a longer duration of antibiotic treatment may be considered for these patients. Otherwise, a 1-day course of antibiotic prophylaxis may be effective enough to prevent device-related infections, and may further reduce the lengths of hospitalizations., Key Words: Complication; Infection; Permanent pacemaker implantation; Prophylatic antibiotics.