Efficient circularization of protein-encoding RNAs via a novel cis-splicing system.

Circular RNAs (circRNAs) have emerged as a promising alternative to linear mRNA, owing to their unique properties and potential therapeutic applications, driving the development of novel approaches for their production. This study introduces a cis-splicing system that efficiently produces circRNAs by incorporating a ribozyme core at one end of the precursor, thereby eliminating the need for additional spacer elements between the ribozyme and the gene of interest (GOI). In this cis-splicing system, sequences resembling homologous arms at both ends of the precursor are crucial for forming the P9.0 duplex, which in turn facilitates effective self-splicing and circularization. We demonstrate that the precise recognition of the second transesterification site depends more on the structural characteristics of P9.0 adjacent to the ωG position than on the nucleotide composition of the P9.0-ωG itself. Further optimization of structural elements, like P10 and P1-ex, significantly improves circularization efficiency. The circRNAs generated through the cis-splicing system exhibit prolonged protein expression and minimal activation of the innate immune response. This study provides a comprehensive exploration of circRNA generation via a novel strategy and offers valuable insights into the structural engineering of RNA, paving the way for future advancements in circRNA-based applications.

Cyclo[2]pyridine[8]pyrrole: An Expanded Porphyrinoid with Three Closed-Shell Oxidation States.

We report here an expanded porphyrinoid, cyclo[2]pyridine[8]pyrrole, 1, that can exist at three closed-shell oxidation levels. Macrocycle 1 was synthesized via the oxidative coupling of two open chain precursors and fully characterized by means of NMR and UV-vis spectroscopies, MS, and X-ray crystallography. Reduction of the fully oxidized form (1, blue) with NaBH4 produced either the half-oxidized (2, teal) or fully reduced forms (3, pale yellow), depending on the amount of reducing agent used and the presence or absence of air. Reduced products 2 or 3 can be oxidized to 1 by various oxidants (quinones, FeCl3, and AgPF6). Macrocycle 1 also undergoes proton-coupled reductions with I-, Br-, Cl-, SO32-, or S2O32- in the presence of an acid. Certain thiol-containing compounds likewise reduce 1 to 2 or 3. This conversion is accompanied by a readily discernible color change, making cyclo[2]pyridine[8]pyrrole 1 able to differentiate biothiols, such as cysteine (Cys), homocysteine (Hcy), and glutathione (GSH).

Quantitative Studies on Local Structure of Molten Binary Potassium Germanates.

In situ high temperature Raman spectra of xK2O-(100-x)GeO2, samples containing 0, 5, 11.11, 20, 25, 33.3, 40, and 50 %mol K2O, were measured. The structure units and a series of model clusters have been designed, optimized, and calculated by quantum chemistry ab initio calculations. The computational simulation in conjunction with the experiments put forward a novel method to correct the experimental Raman spectra of the melts. Deconvolution of the stretching vibrational bands of nonbridging oxygen of [GeO4] tetrahedra of Raman spectra by Gaussian functions was carried out, and the quantitative distribution of different Qn species in molten binary potassium germanates was obtained. The result on all molten samples show that four-fold coordinated germanium atoms occupy a dominant position in the melt and only four-fold coordinated exists in the melt when the K2O content exceeds a certain amount. For melts with high GeO2 content, with the increasing K2O content, the structure of [GeO4] tetrahedra gradually changes from a three-dimensional network consisting of both six-membered and three-membered rings to a three-dimensional network that presents all three-membered rings.

[The effect of surgical revascularization on different timing after ST-elevation myocardial infarction on patients with ischemic heart disease and left ventricular dysfunction].

OBJECTIVE: To analysis the influence of surgical revascularization on different timing after ST-elevation myocardial infarction (STEMI) on patients with coronary artery disease and left ventricular dysfunction. METHODS: Clinical data of 225 patients admitted from January 2003 to July 2012 with history of STEMI and left ventricular dysfunction (ejection faraction<50%) who underwent isolated coronary artery bypass grafting was retrospectively reviewed. There were 186 male and 39 female patients. According to the timing of surgical revascularization after STEMI, the patients were divided into early revascularization group (ER group, <21 days), mid-term revascularization group (MR group, 21 to 90 days) and late revascularization group (LR group, >90 days). There were 20 male and 9 female patients in ER group with mean age of (63 ± 10) years, 48 male and 16 female in MR group with mean age of (63 ± 8) years, 118 male and 14 female in LR group with mean age of (62 ± 10) years, respectively. Thirty-day post-operative mortality and major complications were determined as the endpoints to evaluate the early results of operation. RESULTS: The 30-day post-operative mortality were 3.4%,0 and 2.3% among three groups respectively and there was no statistic difference between groups (χ(2) = 2.137, P = 0.330).Low cardiac output syndrome mortality were 13.8%, 3.1% and 2.3% among three groups respectively and there was statistic difference between groups (χ(2) = 8.344, P = 0.015). The ejection fractions was significantly improved in all the three groups from 42% ± 6%, 41% ± 6% and 42% ± 6% preoperatively to 46% ± 7%, 45% ± 10% and 45% ± 9% postoperatively (t = -3.378 to -2.339, all P < 0.05). The left ventricular end diastolic dimension were significantly reduced in MR group and LR group from (54 ± 6) mm and (55 ± 6) mm preoperatively to (47 ± 8) mm and (49 ± 9) mm postoperatively (t = 5.634, 5.885; P = 0.000). There was no significant change in ER group pre- and postoperatively ((51 ± 6) mm vs.(49 ± 7) mm, t = 1.524, P = 0.133). CONCLUSIONS: The patients with coronary artery disease and left ventricular dysfunction can benefit from surgical revascularization on different timing after STEMI, presenting as the reverse of left ventricle remodeling and the improvement of left ventricle function. The short-term results are mainly determined by the patients' condition, surgical technique and the level of perioperative management.It is recommended for this patient cohort to accept surgical revascularization three weeks after STEMI.

Engineered mRNAs With Stable Structures Minimize Double-stranded RNA Formation and Increase Protein Expression.

The therapeutic use of synthetic message RNA (mRNA) has been validated in COVID-19 vaccines and shows enormous potential in developing infectious and oncological vaccines. However, double-stranded RNA (dsRNA) byproducts generated during the in vitro transcription (IVT) process can diminish the efficacy of mRNA-based therapeutics and provoke innate immune responses. Existing methods to eliminate dsRNA byproducts are often cumbersome and labor-intensive. In this study, we revealed that a loose mRNA secondary structure and more unpaired U bases in the sequence generally lead to the formation of more dsRNA byproducts during the IVT process. We further developed a predictive model for dsRNA byproducts formation based on sequence characteristics to guide the optimization of mRNA sequences, helping to minimize unwanted immune response and improve the protein expression of mRNA products. Collectively, our study provides novel clues and methodologies for developing effective mRNA therapeutics with minimized dsRNA byproducts and increased protein expression.

NanoMUD: Profiling of pseudouridine and N1-methylpseudouridine using Oxford Nanopore direct RNA sequencing.

Nanopore direct RNA sequencing provided a promising solution for unraveling the landscapes of modifications on single RNA molecules. Here, we proposed NanoMUD, a computational framework for predicting the RNA pseudouridine modification (Ψ) and its methylated analog N1-methylpseudouridine (m1Ψ), which have critical application in mRNA vaccination, at single-base and single-molecule resolution from direct RNA sequencing data. Electric signal features were fed into a bidirectional LSTM neural network to achieve improved accuracy and predictive capabilities. Motif-specific models (NNUNN, N = A, C, U or G) were trained based on features extracted from designed dataset and achieved superior performance on molecule-level modification prediction (Ψ models: min AUC = 0.86, max AUC = 0.99; m1Ψ models: min AUC = 0.87, max AUC = 0.99). We then aggregated read-level predictions for site stoichiometry estimation. Given the observed sequence-dependent bias in model performance, we trained regression models based on the distribution of modification probabilities for sites with known stoichiometry. The distribution-based site stoichiometry estimation method allows unbiased comparison between different contexts. To demonstrate the feasibility of our work, three case studies on both in vitro and in vivo transcribed RNAs were presented. NanoMUD will make a powerful tool to facilitate the research on modified therapeutic IVT RNAs and provides useful insight to the landscape and stoichiometry of pseudouridine and N1-pseudouridine on in vivo transcribed RNA species.

Adaptive autonomous emergency braking model based on weather conditions.

OBJECTIVE: Vehicle active safety systems can improve vehicle security by avoiding collisions. An autonomous emergency braking (AEB) system's safety distance calculation is usually based on normal weather conditions. The AEB system's early warning capabilities decrease during adverse weather conditions. METHODS: A multilayer perceptron (MLP) model is used to obtain data from accident and weather data sets. The MLP model is trained and the severity of accidents is predicted. The severity is used as a parameter to build an adaptive AEB system algorithm that considers adverse weather conditions. RESULTS: The adaptive AEB system algorithm increases safety and reliability under adverse weather conditions. Prescan and a driver-in-the-loop system are used to test the adaptive AEB model. Both tests show that the adaptive AEB model has better performance under adverse weather than the traditional AEB model. CONCLUSIONS: The experimental results demonstrate that the adaptive AEB system can increase the safety distance in rainy weather and avoid collisions under hazy conditions.

Extended myectomy for hypertrophic obstructive cardiomyopathy.

BACKGROUND: The purpose of this study was to summarize our experience of extended ventricular septal myectomy in patients with hypertrophic obstructive cardiomyopathy (HOCM). METHODS: Thirty-eight patients (26 men, 12 women) with HOCM underwent extended ventricular septal myectomy. The mean age was 36.3 years (range, 18-64 years). Diagnosis was made by echocardiography. The mean (mean ± SE) systolic gradient between the left ventricle (LV) and the aorta was 89.3 ± 31.1 mm Hg (range, 50-184 mm Hg) according to echocardiographic assessments before the operations. Moderate or severe systolic anterior motion (SAM) of the anterior leaflet of the mitral valve was found in 38 cases, and mitral regurgitation was present in 29 cases. Extended ventricular septal myectomy was performed in all 38 cases. The results of the surgical procedures were evaluated intraoperatively with transesophageal echocardiography (TEE) and with transthoracic echocardiography (TTE) at 1 to 2 weeks after the operation. All patients were followed up with TTE after their operation. RESULTS: All patients were discharged without complications. The TEE evaluations showed that the mean systolic gradient between the LV and the aorta decreased from 94.8 ± 35.6 mm Hg preoperatively to 13.6 ± 10.8 mm Hg postoperatively (P = .0000) and that the mean thickness of the ventricular septum decreased from 28.3 ± 7.9 mm to 11.8 ± 3.2 mm (P = .0000). Mitral regurgitation and SAM were significantly reduced or eliminated. During the follow-up, all patients promptly became completely asymptomatic or complained of mild effort dyspnea only, and syncope was abolished. TTE examinations showed that the postoperative pressure gradient either remained the same or diminished. CONCLUSIONS: Extended ventricular septal myectomy is mostly an effective method for patients with HOCM, and good surgical exposure and thorough excision of the hypertrophic septum are of paramount importance for a successful surgery.

[Comparison of sternotomy off-pump coronary artery bypass and minimally invasive technique for isolated single vessel grafting].

OBJECTIVE: To compare the outcomes of minimally invasive coronary artery bypass grafting operation performed via a small thoracotomy versus da Vinci S system (Endo-A-CAB) with sternotomy off-pump coronary artery bypass grafting (OPCAB) for single vessel lesion. METHODS: From April 2000 to August 2011, a total of 194 patients with single coronary artery stenosis accepted CABG on beating heart were divided into 2 groups by different surgical approaches. Group A (n = 99) received sternotomy OPCAB while Group B (n = 95) underwent Endo-A-CAB. All patients had a history of unstable angina and coronary arteriography showed severe stenosis in left anterior descending artery (LAD). The procedure performed in Group B included robotic internal mammary artery (IMA) harvesting and single manual anastomosis to LAD and/or diagonal branch through small incision thoracotomy. IMA flow was evaluated by the Doppler flow meter after the completion of anastomosis. Grafting patency was evaluated postoperatively by computed tomography angiography (CTA) or angiography. RESULTS: The ventilation time and postoperative drainage volume in Group B were less than those in Group A ((5.1 ± 2.1) vs (10.1 ± 5.8) h, P = 0.03; (411 ± 295) vs (605 ± 244) ml, P = 0.000). No significant difference existed in blood flow, mortality and postoperative complication morbidity between two groups. All symptoms of angina disappeared. CONCLUSION: As a new advanced modality of revascularization, in comparison with OPCAB, Endo-A-CAB procedure is a less invasive and safer method of coronary artery bypass grafting for single vessel lesion.

[Early and midterm outcomes of coronary artery bypass grafting in octogenarians].

OBJECTIVE: To investigate the early and midterm postoperative outcomes and analyze risk factors of coronary artery bypass grafting (CABG) in octogenarians. METHODS: Clinical data of 38 patients aged 80 years or greater receiving isolated coronary artery bypass grafting from September 2001 to November 2010 were reviewed. There were 33 male and 5 female patients, aging from 80 to 87 years with a mean of (82.6 ± 1.2) years. Twelve patients underwent conventional (on-pump) CABG and 26 patients underwent off-pump CABG. The number of bypass grafts was 1 to 5 (mean 2.5 ± 1.1). Left internal mammary artery was used in 37 (97.3%) patients. RESULTS: The perioperative mortality was 2.6% (1/38). Postoperative complications included stroke (4 cases), respiratory infection (1 case). The atrial arrhythmias occurred in 25 patients. Intensive care unit and hospital length of stay lasted (3.8 ± 1.4) days and (15 ± 6) days, respectively. Totally 38 patients were followed up for 4 to 70 months. Six patients died during the follow-up period. The 92.6% patients recovered without any cardiac events. CONCLUSIONS: Isolated CABG can be performed safely with acceptable postoperative morbidity and mortality in octogenarians. Appropriate surgical strategy and intensive perioperative treatment must be enhanced in octogenarians who underwent CABG.

[Surgical treatment with modified Morrow procedure in hypertrophic obstructive cardiomyopathy].

OBJECTIVE: To summarize the experience of ventricular septal myectomy (modified Morrow procedure) in patients with hypertrophic obstructive cardiomyopathy (HOCM). METHODS: From June 2003 to March 2011, 38 patients (26 male and 12 female) with HOCM underwent modified Morrow procedure. The mean age was 36.3 years (ranging from 18 to 64 years). The diagnosis was made by echocardiography and spiral CT. The mean systolic gradient between the left ventricle and the aorta from transthoracic echocardiography (TTE) was (89±31) mmHg (ranging from 50 to 184 mmHg, 1 mmHg=0.133 kPa) before operation. There was moderate or severe systolic anterior motion (SAM) in 38 cases and mitral regurgitation in 29 cases. Ventricular septal myectomy with modified Morrow procedure was performed in all 38 cases. TEE was used intraoperatively to evaluate the results of the surgical procedures. After 1 to 2 weeks of operation, TTE was performed to evaluate the effect of operation. All patients were followed up with TTE after operation. RESULTS: All patients were discharged without complications. Intraoperative TEE showed that the mean systolic gradient between the left ventricle and the aorta was decreased from (95±36) mmHg before procedures to (14±11) mmHg after operation (t=13.265, P=0.000), and the thickness of ventricular septum was decreased from (28±8) mm to (12±3) mm (t=11.656, P=0.000). TTE showed that the mean systolic gradient between the left ventricle and the aorta was decreased from (89±31) mmHg preoperatively to (18±13) mmHg (t=12.729, P=0.000) in 1 to 2 weeks after operation. Mitral regurgitation and SAM were significantly improved or disappeared (t=7.930, t=5.213, both P=0.000). During the follow-up, all patients promptly became completely asymptomatic or complained of mild effort dyspnea only and syncope was abolished, and TTE showed that the pressure gradient was kept on the postoperative level or slightly decreased (P=0.494). CONCLUSIONS: Ventricular septal myectomy with modified Morrow procedure is a mostly effective method for patients with HOCM. Good surgical exposure and the hypertrophied septum thoroughly excised are paramount for successful surgery.

[Analysis of blood flow in sequential and individual saphenous vein grafts in off-pump coronary artery bypass grafting].

OBJECTIVE: To compare the blood flow in sequential and individual saphenous vein grafts (SVGs) and to analyze the influence of the location of the target vessel in off-pump coronary artery bypass grafting (OPCAB). METHODS: A total of 464 SVGs in 412 patients receiving OPCAB were nested into individual SVG (n=206), double (n=241) or triple sequential SVG (n=15), and analyzed. RESULTS: The blood flow in double and triple SVGs was significantly higher than in individual SVGs [(43.4±22.5), (43.7±19.2) and (28.9±18.7) mL/min, respectively, P<0.001, P=0.047]. There were no differences between flow in double and triple SVGs (P=0.96). Pulsatility index (PI) of the three groups were similar (2.6±1.2, 2.5±1.6, 2.8±0.9, respectively, P=0.49, P=0.49). In individual SVGs to right coronary artery, the blood flow was higher than in the posterior descending branch (PDA) (P=0.047) and posterior branch of left ventricle (PBLV), the flow-time in systole period was longer than diagonals (P=0.003), obtuse marginal (OM) (P=0.013) and PDA (P=0.002), PI was significantly lower than PDA (P=0.033) and PBLV (P=0.032). The blood flow in individual SVGs to diagonals was significantly lower than in other target vessels except for PBLV (P<0.05). Flow in double SVGs to PDA-PBLV was significantly lower than in PDA-OM. CONCLUSION: The mean blood flow in double and triple sequential SVGs is about 1.5 times higher than in individual SVGs. Individual, double, and triple SVGs have similar pI. Flow in individual SVGs to diagonals was significantly lower than in other target vessels except for PBLV.

Eleven-year outcomes of U-clips in totally robotic coronary artery bypass grafting versus standard hand-sewn running suture in robotic-assisted coronary artery bypass grafting.

OBJECTIVES: The aim of this study was to evaluate the clinical outcomes of patients undergoing off-pump robotic coronary artery bypass grafting (CABG) with either interrupted nitinol U-Clips in totally endoscopic coronary artery bypass (TECAB) or standard running suture anastomosis in robotically assisted direct coronary artery bypass (RADCAB) over a decade. METHODS: From January 2007 to December 2017, 280 patients underwent robotic off-pump CABG using the da Vinci S/Si Surgical System in our centre. TECAB with interrupted nitinol U-Clips anastomosis was performed in the left internal mammary artery (LIMA) to LAD grafting in 126 patients and RADCAB (n = 154) of the LIMA to LAD was completed with standard running suture. After discharge, patients were contacted through telephone interview and were invited to attend the outpatient clinic every 6 months or 1 year. The graft patency was assessed by coronary angiography or computed tomography angiography. RESULTS: All cases were completed without conversion to median sternotomy or cardiopulmonary bypass. A total of 275 single internal mammary artery (IMA) grafts (271 LIMAs, 4 right internal mammary arteries) and 5 bilateral IMA grafts were used as single graft or composite grafts. All the patients were discharged without in-hospital mortality or adverse outcomes. The average follow-up was 89.7 ± 30.4 months (range, 14-143 months). The cumulative survival rates (P = 0.53), the cumulative IMA patency rates (P = 0.83), and the rates of freedom from major adverse cerebrovascular and cardiovascular events (P = 0.41) between TECAB and RADCAB all showed no significant difference in the follow-up. CONCLUSIONS: Robotic off-pump CABG using IMA grafts is safe and can provide reliable long-term outcomes. Compared with the standard hand-sewn running suture technique in RADCAB, interrupted suture with the nitinol U-Clips in TECAB showed similar long-term clinical results and graft patency in LIMA to LAD bypass grafting.

New exon and accelerated evolution of placental gene Nrk occurred in the ancestral lineage of placental mammals.

INTRODUCTION: The chorioallantoic placenta is a specific organ for placental mammals. However, the adaptive events during its emergence are still poorly investigated. METHODS: We scanned the chromosome X to detect the accelerated evolution in the ancestral lineage of placental mammals, and constructed 3D protein structure models of a candidate by homology modeling. RESULTS: Eight branch-specific accelerated regions were identified. Five of these regions (P=5.61×10-11 ~ 9.03×10-8) are located in the five exons of Nik-related kinase (Nrk), which is essential in placenta development and fetoplacental induction of labor. Nrk belongs to the germinal center kinase-IV subfamily with the overall similar protein structure; however, a new exon emerged in ancestors of placental mammals and its sequence has been conserved since then. Structure modelling of NRK suggests that the accelerated exons and the placental-mammal-specific exon (as a new loop) could change the enzymatic activity and the structure of placental mammal NRK. DISCUSSION: Since the new loop is surrounded by the accelerated protein regions, it is likely that the new loop occurred and shifted the function of NRK, and then the accelerated evolution of Nrk occurred to adapt the structure change caused by the new loop in the ancestral lineage of placental mammals. Overall, this work suggests that the fundamental process of placental development and fetoplacental induction of labor has been targeted by positive Darwinian selection.

Pyridazine-bridged expanded rosarin and semi-rosarinogen.

The synthesis of the pyridazine-bridged expanded rosarin 1 and a reduced precursor, semi-rosarinogen 2, is reported. A single crystal X-ray diffraction analysis of 1 and theoretical calculations show that both 1 and 2 have distorted structures. Expanded rosarin 1 and its precursor 2 can differentiate various thiols in organic solvents by means of species-specific colour changes and reaction times.

Pickering emulsions stabilized by a lipophilic surfactant and hydrophilic platelike particles.

Liquid paraffin-water emulsions were prepared by homogenizing oil phases containing sorbitan oleate (Span 80) and aqueous phases containing layered double hydroxide (LDH) particles or Laponite particles. While water-in-oil (w/o) emulsions are obtained by combining LDH with Span 80, the emulsions stabilized by Laponite-Span 80 are always o/w types regardless of the Span 80 concentration. Laser-induced fluorescent confocal micrographs indicate that particles are absorbed on the emulsion surfaces, suggesting all the emulsions are stabilized by the particles. The difference of the particle-stabilized emulsion type may be explained by comparing particle contact angles and the oil-water interfacial tensions, indicating that more Span 80 molecules are adsorbed on the LDH particles than on Laponite. Apparently, the LDH particles are rendered more hydrophobic by Span 80, resulting in the formation of w/o emulsions. The long-term stability of the emulsions was also compared. Emulsions stabilized by Span 80 alone completely separate into two bulk phases of oil and water after 3 months. However, emulsion stability is greatly enhanced with the addition of LDH or Laponite particles. This synergism was accounted for by an increase of the dilational viscoelasticity modulus of the oil-water interface after particles were added to the aqueous phase. This increase indicates that the gel-like particle layer stays at the oil-water interface and resists emulsion coalescence. Scanning electron microscope (SEM) images display the presence of a firm layer surrounding the emulsion droplets and a three-dimensional particle network which extends into the bulk phase aiding emulsion stability.

Accelerated evolution of an Lhx2 enhancer shapes mammalian social hierarchies.

Social hierarchies emerged during evolution, and social rank influences behavior and health of individuals. However, the evolutionary mechanisms of social hierarchy are still unknown in amniotes. Here we developed a new method and performed a genome-wide screening for identifying regions with accelerated evolution in the ancestral lineage of placental mammals, where mammalian social hierarchies might have initially evolved. Then functional analyses were conducted for the most accelerated region designated as placental-accelerated sequence 1 (PAS1, P = 3.15 × 10-18). Multiple pieces of evidence show that PAS1 is an enhancer of the transcription factor gene Lhx2 involved in brain development. PAS1s isolated from various amniotes showed different cis-regulatory activity in vitro, and affected the expression of Lhx2 differently in the nervous system of mouse embryos. PAS1 knock-out mice lack social stratification. PAS1 knock-in mouse models demonstrate that PAS1s determine the social dominance and subordinate of adult mice, and that social ranks could even be turned over by mutated PAS1. All homozygous mutant mice had normal huddled sleeping behavior, motor coordination and strength. Therefore, PAS1-Lhx2 modulates social hierarchies and is essential for establishing social stratification in amniotes, and positive Darwinian selection on PAS1 plays pivotal roles in the occurrence of mammalian social hierarchies.

Robotic mitral valve repair: 7-year surgical experience and mid-term follow-up results.

BACKGROUND: The feasibility and safety of robotic mitral valve repair has been proven in several studies but the mid-term to long-term outcomes are unclear. We aim to summarize our surgical experience with robotic mitral valve repair and demonstrate the follow-up results out to 7 years. METHODS: From 2007 to 2014, 110 consecutive patients underwent robotic mitral valve repair with da Vinci Surgical System (Intuitive Surgical, USA) in our center. The operative data were collected, and patients were echocardiographically followed regularly up to 7 years. RESULTS: The patients' average age was 45±13 (14 to 70) years with male to female ratio of 2.3:1. Mitral regurgitation (95.5%) or stenosis (4.5%) was diagnosed. The triangular or quadrangular resection was the most performed type of repair (63.3%). Nitinol U-clips (58.1%), running suture (31.1%), and Cor-Knot™ suture device (LSI Solutions, Victor, NY) (10.8%) were used to secure the annuloplasty ring. All cases were performed by the same surgeon. One case of conversion to sternotomy was noted. The mean CPB time was 121±34.3 (range, 70 to 152) minutes, and the mean cross-clamp time was 82.6±25.3 (range, 47 to 122) minutes. After surgery, one death (0.91%) and two cases of transient neurocognitive defect (1.82%) occurred. Three cases of early failure of repair that required reoperation (2.73%) were noticed. All patients were successfully followed for a median of 4.1 (range, 1 month to 7 years) years and 94.5% had freedom of re-operation. CONCLUSIONS: Robotic mitral valve repair is a safe and effective procedure with excellent mid-term outcomes.

[Diagnostic study on the coronary artery bypass grafts lesions using 64 multi-slice computed tomography angiography].

OBJECTIVE: To evaluate the diagnostic accuracy in the assessment of coronary artery bypass grafts using 64 multi-slice computed tomography angiography (64-MSCTA) technology. METHODS: There were 228 patients post coronary artery bypass grafting (CABG) underwent 64-MSCTA from July 2005 to April 2007. Thirty-one patients with 82 bypass grafts performed coronary angiography (CAG) because of angina or grafts lesion showed by 64-MSCTA. RESULTS: All bypass grafts could be visualized by 64-MSCTA. Thirteen bypass graft occlusions and fourteen significant stenosis were detected by 64-MSCTA and confirmed by CAG. One venous grafts distal anastomosis was missed and another one was miss diagnosed as stenosis. One false negative and one false positive CT-finding resulted in a sensitivity of 93.3%, a specificity of 98.1%, a positive predictive value of 93.3%, a negative predictive value of 98.1% and an accuracy of 97.1% for grafts stenosis. As to the grafts lesion, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy for grafts occlusion were 96.4%, 98.1%, 96.4%, 98.1% and 97.6%, respectively. CONCLUSION: 64-MSCTA demonstrates high diagnostic accuracy in the assessment of graft patency and suitable for the follow-up of patients post CABG.