MicroRNA-17-mediated down-regulation of apoptotic protease activating factor 1 attenuates apoptosome formation and subsequent apoptosis of cardiomyocytes.

Heart diseases such as myocardial infarction (MI) can damage individual cardiomyocytes, leading to the activation of cell death programs. The most scrutinized type of cell death in the heart is apoptosis, and one of the key events during the propagation of apoptotic signaling is the formation of apoptosomes, which relay apoptotic signals by activating caspase-9. As one of the major components of apoptosomes, apoptotic protease activating factor 1 (Apaf-1) facilitates the formation of apoptosomes containing cytochrome c (Cyto-c) and deoxyadenosine triphosphate (dATP). Thus, it may be possible to suppress the activation of the apoptotic program by down-regulating the expression of Apaf-1 using miRNAs. To validate this hypothesis, we selected a number of candidate miRNAs that were expected to target Apaf-1 based on miRNA target prediction databases. Among these candidate miRNAs, we empirically identified miR-17 as a novel Apaf-1-targeting miRNA. The delivery of exogenous miR-17 suppressed Apaf-1 expression and consequently attenuated formation of the apoptosome complex containing caspase-9, as demonstrated by co-immunoprecipitation and immunocytochemistry. Furthermore, miR-17 suppressed the cleavage of procaspase-9 and the subsequent activation of caspase-3, which is downstream of activated caspase-9. Cell viability tests also indicated that miR-17 pretreatment significantly prevented the norepinephrine-induced apoptosis of cardiomyocytes, suggesting that down-regulation of apoptosome formation may be an effective strategy to prevent cellular apoptosis. These results demonstrate the potential of miR-17 as an effective anti-apoptotic agent.

Preoperative coronary angiography within one day of valve surgery is not associated with postoperative acute kidney injury in patients with preserved renal function.

BACKGROUND: Acute kidney injury (AKI) is a common complication after cardiac surgery. Associations between the time interval (TI) from preoperative coronary angiography (CAG) to cardiac surgery have been investigated, although with conflicting results. METHODS: We evaluated data collected from a retrospective review of consecutive patients who underwent preoperative CAG and heart valve surgery at our institution between September 2008 and February 2013. A total of 426 patients met the study criteria. Patients were divided into two groups according to the length of time between preoperative CAG and valve surgery: within one day (group A) or longer than one day (group B). Logistic regression was applied to analyze the relationships between TI and postoperative AKI. RESULTS: Of 426 patients, 140 (33%) underwent CAG on preoperative day 1, while 286 (67%) underwent CAG on preoperative day 2 or sooner. AKI occurred in 19 (13.6%) patients in group A and in 35 (12.2%) patients in group B (p = 0.70). CAG on preoperative day 1 was not associated an increased risk of AKI relative to CAG on preoperative day 2 or sooner (p = 0.49; odds ratio, 1.26; 95% CI, 0.66 to 2.41). CONCLUSIONS: Preoperative CAG within one day of elective heart valve surgery is not associated with an increase in postoperative AKI in patients with normal renal function.

Effects of preemptive cerebrospinal fluid drainage on spinal cord protection during thoracic endovascular aortic repair.

BACKGROUND: Spinal cord injury (SCI) is reported to occur in 3-12% of thoracic endovascular aortic repair (TEVAR) cases, but is a potentially preventable complication of TEVAR for thoracoabdominal pathologies. Although many strategies have been devised to reduce the incidence of SCI, the effectiveness of prophylactic cerebrospinal fluid drainage (CSFD) and left subclavian artery (LSA) revascularization remains controversial. METHODS: From 2012 to 2014, 162 patients underwent TEVAR at a single institution. We prospectively collected and retrospectively reviewed the data of 81 patients who underwent preoperative CSFD among the 162 patients. LSA revascularization was routinely used when LSA need to be covered. Preoperative characteristics, intraoperative variables, and outcomes were analyzed. RESULTS: The mean (SD) age of the patients was 60.6 (12.5) years, and 57 patients (70%) were male. Twenty-five patients (31%) presented with degenerative aneurysm; 48 (59%), type B dissection; 5, (6%) penetrating aortic ulcer; and 3 (4%), intramural hematoma. Thirty-six patients (44%) underwent LSA revascularization before TEVAR. Two (2.5%) of the patients who underwent preoperative CSFD had SCI, of whom one recovered ambulatory status at discharge after hypertensive therapy and another had a permanent disability. Prior abdominal aortic aneurysm (AAA) repair tended to relate to SCI (P=0.065), and preoperative aortic rupture was a significant independent risk factor of SCI (P=0.002). CONCLUSIONS: Preemptive CSFD as an adjunctive procedure to TEVAR proved to be more effective than selective use of CSFD in other prior reports of SCI cases. Preoperative CSFD is recommended as a prophylactic procedure in patients at high risk of SCI during TEVAR.

An implementation of sensor-based force feedback in a compact laparoscopic surgery robot.

Despite the rapid progress in the clinical application of laparoscopic surgery robots, many shortcomings have not yet been fully overcome, one of which is the lack of reliable haptic feedback. This study implemented a force-feedback structure in our compact laparoscopic surgery robot. The surgery robot is a master-slave configuration robot with 5 DOF (degree of freedom corresponding laparoscopic surgical motion. The force-feedback implementation was made in the robot with torque sensors and controllers installed in the pitch joint of the master and slave robots. A simple dynamic model of action-reaction force in the slave robot was used, through which the reflective force was estimated and fed back to the master robot. The results showed the system model could be identified with significant fidelity and the force feedback at the master robot was feasible. However, the qualitative human assessment of the fed-back force showed only limited level of object discrimination ability. Further developments are underway with this result as a framework.