When Supramolecular Chemistry Meets Chemical Biology: New Strategies to Target Proteins through Host-Guest Interactions.

Supramolecular chemistry for targeting proteins is of great interest for the development of novel approaches to recognize, isolate and control proteins. Taking advantage of chemical biology approaches, such as genetic-code expansion and enzyme-mediated ligation, guest recognition elements can be built into proteins of interest, allowing supramolecular control of protein function and regulation. In this viewpoint article, we will discuss the methods, applications, limitations, and future perspectives of supramolecular chemistry for targeting proteins in a site-specific manner.

Long-term clinical outcomes in transradial versus transfemoral access for left main percutaneous coronary intervention.

OBJECTIVE: The present study compared 10-year clinical outcomes between transradial access (TRA) and transfemoral access (TFA) for left main (LM) percutaneous coronary intervention (PCI). BACKGROUND: There are limited data regarding the long-term safety and efficacy of TRA for LM PCI. METHODS: This retrospective study evaluated consecutive patients who underwent unprotected LM PCI between January 2004 and December 2008 at Fu Wai Hospital. The exclusion criteria were age of less than 18 years and presentation with acute myocardial infarction. The primary endpoint was major adverse cardiac or cerebrovascular events (MACCE), which was defined as a composite of all-cause death, myocardial infarction, stroke, and any revascularization at the 10-year follow-up. RESULTS: Among 913 eligible patients, TRA was used for 417 patients (45.7%) and TFA was used for 496 patients (54.3%). The 30-day clinical outcomes were similar between the two groups. Results from the 10-year follow-up revealed that MACCE occurred in 180 patients (46.7%) from the TRA group and in 239 patients (51.2%) from the TFA group (log-rank p = .3). The TRA and TFA groups also had low and comparable cumulative rates of all-cause death (14.6% vs. 17.3%, log-rank p = .56) and cardiac death (7.9% vs. 9.1%, log-rank p = .7). CONCLUSION: The present study revealed no significant differences in long-term clinical outcomes when TRA or TFA were used for LM PCI.

Long-Term Clinical Outcomes of Unprotected Left Main Percutaneous Coronary Intervention: A Large Single-Centre Experience.

AIMS: This study sought to report the 10-year clinical outcomes of patients who underwent unprotected left main (LM) percutaneous coronary intervention (PCI) in a large centre. METHODS AND RESULTS: A total of 913 consecutive patients who underwent unprotected LM PCI from January 2004 to December 2008 at Fu Wai Hospital were retrospectively analysed; the mean age was 60.0 ± 10.9 years, females accounted for 22% of patients, diabetes was present in 27.7% of patients, and an LM bifurcation lesion occurred in 82.9% of patients. During the median follow-up of 9.7 years, major adverse cardiac or cerebrovascular events (MACCEs) occurred in 25.6% (234) of patients, and the rates of all-cause death, myocardial infarction, and stroke were 14.9%, 11.0%, and 7.1%, respectively. Cardiac death occurred in only 7.9% of patients. The estimated event rate was 41.9% for death/myocardial infarction/any revascularization and 45.9% for death/MI/stroke/any revascularization. Definite/probable stent thrombosis occurred in 4.3% (39) of patients. According to the subgroup analysis, IVUS-guided PCI was associated with less long-term MACCEs. Further multivariate analysis identified that age and LVEF<40% were the only independent predictors for 10-year death. Age, LVEF<40%, creatinine clearance, and incomplete revascularization were independent predictors for death/MI, while a two-stent strategy, diabetes, a transradial approach, and the use of bare metal stents (BMSs) or first-generation drug-eluting stents (DESs) were not. CONCLUSIONS: Unprotected LM PCI in a large cohort of consecutive patients in a single large centre demonstrated favourable long-term outcomes up to 10 years even with the use of BMSs and first-generation of DESs.

A General Supramolecular Approach to Regulate Protein Functions by Cucurbit[7]uril and Unnatural Amino Acid Recognition.

Regulation of specific protein function is of great importance for both research and therapeutic development. Many small or large molecules have been developed to control specific protein function, but there is a lack of a universal approach to regulate the function of any given protein. We report a general host-guest molecular recognition approach involving modification of the protein functional surfaces with genetically encoded unnatural amino acids bearing guest side chains that can be specifically recognized by cucurbit[7]uril. Using two enzymes and a cytokine as models, we showed that the activity of proteins bearing unnatural amino acid could be turned off by host molecule binding, which blocked its functional binding surface. Protein activity can be switched back by treatment with a competitive guest molecule. Our approach provides a general tool for reversibly regulating protein function through molecular recognition and can be expected to be valuable for studying protein functions.

An Orthogonal Tyrosyl-tRNA Synthetase/tRNA Pair from a Thermophilic Bacterium for an Expanded Eukaryotic Genetic Code.

The Escherichia coli-derived tyrosyl-tRNA synthetase was the first enzyme engineered for genetic code expansion in a eukaryotic system but can charge only a limited set of structurally simple noncanonical amino acids. In contrast, the thermophilic Methanocaldococcus jannaschii-derived tyrosyl-tRNA synthetase mutants, used in only a prokaryotic system, can charge a surprisingly large set of structurally diverse ncAAs, due to their remarkable structural ability to tolerate mutations. Inspired by this, we characterized a new class of tyrosyl-tRNA synthetase/tRNATyr pairs from thermophilic bacterium Geobacillus stearothermophilus, which is homologous to the E. coli tyrosyl-tRNA synthetase but with better thermostability. This new pair is both orthogonal in mammalian cells and in Saccharomyces cerevisiae for genetic code expansion and can charge a diverse set of ncAAs with a comparable cellular efficiency, better specificity, and lower background, as compared to those of its E. coli homologue. This thermostable enzyme provides an alternative scaffold for synthetase library screening or evolution to genetically encode more structurally complex ncAAs in eukaryotic cells.

Proteomic Identification of Protein Tyrosine Phosphatase and Substrate Interactions in Living Mammalian Cells by Genetic Encoding of Irreversible Enzyme Inhibitors.

Protein tyrosine phosphatases (PTPs) play critical roles in cell signaling pathways, but identification of unknown PTPs for a given substrate in live cells remain technically challenging. Here, we synthesized a series of tyrosine-based irreversible PTP inhibitors and characterized by site-specific encoding on substrate proteins in cells with an expanded genetic code. By fine-tuning the chemical reactivity, we identified optimal active amino acid probes to covalently cross-link a PTP and its substrate both in vitro and in mammalian cells. Using HER2 as an example, we provide first direct evidence of HER2 Y1023 and SHP2 cross-linking in situ in living human cells. Moreover, proteomic analysis using our approach identified PTP1B as a novel phosphatase for HER2 that specifically dephosphorylated pY1221 position, which may shed light on the puzzle of PTP1B's role in HER2 positive breast cancer. This novel method provides a useful tool for dissecting tyrosine phosphoregulation in living cells.

Comparison of procedural and long-term outcomes between transradial and transfemoral approach in one-stage intervention for triple vessel coronary artery disease.

OBJECTIVES: The aim of the present study was to evaluate the safety, feasibility, procedural, and long-term outcomes by the transradial (TR) approach as compared to transfemoral (TF) approach in patients with triple vessel coronary artery disease undergoing one-stage percutaneous coronary intervention. BACKGROUND: The feasibility, safety, and efficacy between the TR and TF approach for coronary interventional treatment have been compared in some complex situations including AMI and unprotected left main disease. However, in terms of triple vessel disease (3VD) intervention, there has been no comparison regarding procedural and long-term outcomes between the TR and TF approach. METHODS: A total of 4,974 consecutive patients (TR n = 3,856, TF n = 1,118), who were diagnosed with 3VD without LM disease and underwent one-stage percutaneous revascularization, were enrolled in the study. Procedural results and clinical outcomes were obtained through database and follow-up. We used the propensity score matching method and obtained 930 pairs of patients with comparable baseline data in order to compare the procedural and long-term outcome between TR and TF groups. In the study cohort, risk reduction of all the clinical outcomes were evaluated with Cox's proportional-hazards models. Cumulative incidences concerning safety and efficacy of the cohort were estimated by the Kaplan-Meier method and a comparison was made utilizing the log-rank test. RESULTS: After propensity score matching, the baseline clinical and angiographic characteristics were similar between the 2 groups. Regarding procedural results, no significant differences were observed between the 2 groups, with the exception of a decreased hospital stay (TR 7.49 ± 4.46 days vs. TF 8.63 ± 6.23 days, P < 0.0001) and fewer bleedings (TR 1.0% vs. TF 2.9, P = 0.003) in the TRI group. After an average 21-month follow-up, the all-cause mortality (TR 1.7% vs. TF 4.2%, P = 0.0014; HR 0.44, 0.25-0.79) was significantly lower with TRI patients. Other clinical outcomes were comparable between the 2 groups. CONCLUSIONS: As compared to TFI, TRI for 3VD intervention is feasible, safe, and associated with similar procedural success, shorter hospitalization, reduced bleeding, lower incidence of death, and comparable long-term efficacy.

[Clinical features and outcome of eight patients with mediastinal and neck hematoma after transradial cardiac catheterization approach].

OBJECTIVE: The clinical features of patients with mediastinal and/or neck hematoma after transradial cardiac catheterization were reviewed and analyzed to help the clinicians to recognize this complication, and try their best to avoid the complication and treat the complication properly. METHODS: A total of 8 patients with mediastinal and/or neck hematoma after right transradial cardiac catheterization in Fuwai hospital from January 1, 2005 to the end of 2012 were included in this study. Among these 8 patients, 1 patient underwent coronary angiography, 7 patients underwent percutaneous coronary intervention and drug eluting stents were successfully implanted in 6 patients. The clinical data of these patients were analyzed retrospectively. RESULTS: Super slide hydrophilic guild-wire was used in all patients. These patients felt chest pain, dyspnea and neck pain and neck or throat tightness after the procedure. CT scan was performed in all 8 patients and reviewed mediastinal hematoma, 4 patients complicated with neck hematoma, and suspicious laceration on the right subclavian artery or branch of innominate artery were found in 2 patients. Post procedure hemoglobin decrease was evidenced in all 8 patients. Anti-platelet therapy was discontinued until discharge in 2 patients, dual anti-platelet drugs were transiently discontinued or underwent dosage reduction in 4 patients, protamine was administered in 2 patients to neutralize heparin. Blood transfusion was not required, there was no stent thrombosis, and surgery was not indicated for all 8 patients. No complication was reported during follow up. CONCLUSIONS: Mediastinal and/or neck hematoma is a rare complication post transradial catheterization approach. This complication is caused by super slide guild-wire or catheter's injury of small vessels near the aortic arch or subclavian artery, especially with rough manipulation. Neck and mediastinal CT scan should be performed as early as possible for patients with suspect hematoma and prognosis is usually fine with suitable therapy.

Supplementing maternal diet with milk oligosaccharides and probiotics helps develop the immune system and intestinal flora of offsprings.

Intestinal flora is very important for improving the development of the immune system in newborns. Maternal diet during pregnancy and lactation is one of the key factors affecting the growth and development of offspring. The objective of the present study was to examine whether supplementation of maternal diet with milk oligosaccharides and Bifidobacterium could influence the development of the intestinal flora and immune system of neonatal mice. In total, 30 pregnant Institute of Cancer Research (ICR) mice were randomly divided into six groups: a control group (basal diet) and five intervention groups (basal diet supplemented with different doses of 2'-fucosyllactose [2'-FL] and Bifidobacterium Bb12) during the pregnancy period. All female mice were monitored for physical health during gavage. After delivery, the number of mice in each litter, any deformity, and the development of the offspring were recorded. The spleen, blood, and fecal samples of six groups of 10-12 day-old offspring were collected. The results demonstrated that maternal milk oligosaccharides and probiotics conferred protective effects against lipopolysaccharide (LPS)-induced immunosuppression in mice offspring by significantly enhancing the immune organ indexes, splenocyte proliferation, immunoglobulin (immunoglobulin G, A, M) production as well as improving the macrophage phagocytosis (p < .05). The abundance of Lactobacilli and Bifidobacteria in the feces of offspring mice in the intervention groups was significantly higher than that of the offspring mice in the control group (p < .05). These findings suggest that the combination of 2'-FL and Bifidobacterium Bb12 displayed synergistic interactions between the two components that could promote the development of the immune system of the offsprings and improve their microbiota through maternal ingestion.

Recent Advances in Genetic Code Expansion Techniques for Protein Phosphorylation Studies.

Protein phosphorylation is a reversible, residue-specific posttranslational modification that plays a pivotal role in cell signaling, and the phosphorylation state of proteins is tightly regulated by kinases and phosphatases. Malfunction of this regulation is often associated with human diseases, and therefore elucidation of the function and regulation of this posttranslational modification is important. Genetic code expansion, which allows for site-specific introduction of noncanonical amino acids directly into target proteins in response to a non-sense codon is a powerful method for preparing homogeneously phosphorylated proteins both in Escherichia coli and mammalian cells and therefore is useful for studying protein phosphorylation. Herein, we summarize recent developments in the application of genetic code expansion for protein phosphorylation studies.

[Impact of cytochrome P450 2C19 polymorphisms on outcome of cardiovascular events in clopidogrel-treated Chinese patients after percutaneous coronary intervention].

OBJECTIVE: To investigate the impact of cytochrome P450 (CYP) 2C19 681G > A polymorphism on long-term prognosis of clopidogrel-treated Chinese patients after percutaneous coronary intervention (PCI). METHODS: Between January 1, 2009 and August 31,2009, 267 patients with coronary heart disease who received PCI and treated with clopidogrel for 12 months were enrolled. CYP2C19 * 2 was detected by MALDI-TOF MS and patients were grouped into CYP2C19 * 1/ * 1 (n = 130) and CYP2C19 * 2 carriers group (n = 137). Follow-up was 12 months. The primary endpoint was angina recurrence, urgent coronary revascularization, acute myocardial infarction, stent thrombosis, death and the combined end points. RESULTS: Baseline data were similar between two groups (P > 0.05). Urgent coronary revascularization and the combined end points occurred more frequently in CYP2C19 * 2 carriers than in CYP2C19 * 1/* 1 patients (7.3% vs. 1.5% and 8.0% vs. 2.3% respectively, all P < 0.05). But incidence of angina recurrence, acute myocardial infarction, stent thrombosis and death was similar between two groups (all P > 0.05). Hazard risk of 1 year cumulative survival of CYP2C19 * 2 carriers group was significantly higher than CYP2C19 * 1/ * 1 group after PCI ( HR = 3.59, 95% CI: 1.02 - 12.87, P < 0.05). CONCLUSION: CYP2C19 681G > A polymorphism is a determinant of prognosis in coronary heart disease patients receiving chronic clopidogrel treatment after PCI.

[The in-hospital outcome and predictors of major adverse cardiac events after transradial intervention in patients with coronary artery disease].

OBJECTIVE: The purpose of this study is to evaluate the in-hospital clinical outcome of patients with coronary artery disease who underwent transradial intervention (TRI) and analyze the predictors of clinical outcome. METHODS: From May 2004 to May 2009, there were 16 281 patients who underwent transradial intervention, as well as 5388 patients who underwent transfemoral intervention (TFI) at our institution. The clinical characteristics, procedural characteristics, and in-hospital clinical adverse events were compared between TRI and TFI groups. Multivariable logistic regression analysis was performed to determine predictors of in-hospital major adverse cardiac events (composite of death, myocardial infarction, or target lesion revascularization) of TRI. RESULTS: The annulations time was significantly longer for TRI than TFI (P < 0.01), fluoroscopy time, amount of contrast agent and procedural success rate (95.5% for TRI and 96.2% for TFI) were similar between the two groups. However, the rates of vascular complications (0.1% for TRI group and 1.3% for TFI group, P < 0.01), incidence of in-hospital major adverse cardiac events (1.6% vs. 3.8%, P < 0.01) and in-hospital death (0.2% vs. 0.4%, P < 0.01) were all significantly lower in TRI group compared with TFI group. The following characteristics were identified as independent multivariate predictors of in-hospital major adverse cardiac events of TRI: age ≥ 65 (OR: 1.98, 95%CI: 1.50 - 2.61, P < 0.01), prior myocardial infarction (OR: 2.14, 95%CI: 1.63 - 2.82, P < 0.01), use of drug-eluting stent (DES) (OR: 0.68, 95%CI: 0.47 - 0.98, P = 0.04), dissection during procedure (OR: 4.08, 95%CI: 2.28 - 7.33, P < 0.01), left main lesion (OR: 2.12, 95%CI: 1.09 - 4.13, P = 0.03), number of implanted stents (OR: 1.25, 95%CI: 1.09 - 1.43, P < 0.01), and total stented length (OR: 1.01, 95%CI: 1.00 - 1.02, P = 0.03). CONCLUSIONS: In this large single-centre patient cohort, the transradial intervention is superior to transfemoral intervention in terms of in-hospital safety and efficacy. Age ≥ 65, prior myocardial infarction, use of DES, dissection during procedure, left main lesion, number of implanted stents and total stented length were identified as independent multivariate predictors of in-hospital major adverse cardiac events of TRI.

Stent thrombosis following 2 drug-eluting stent implantations for coronary bifurcation lesion: a single-center analysis.

BACKGROUND: The incidence of stent thrombosis (ST) following 2 drug-eluting stent (DES) implantations for coronary bifurcation lesions needs to be identified. METHODS: From April 2004 to April 2009, 705 consecutive patients with true bifurcation lesions who underwent a double stenting procedure with DES at the Fu Wai Hospital were analyzed. RESULTS: Six (0.85%) patients had a definite ST, all of them had an early (4 acute and 2 subacute) definite ST. Probable ST occurred in 4 patients; in all of these cases, the event occurred early and was adjudicated because of the occurrence of sudden death within 30 days of the procedure. Therefore, a total of 10/705 (1.42%) patients had a definite or probable ST. Possible stent thrombosis was adjudicated only in 1 patient 371 days after the initial PCI in whom the cause of death was unexplained. Compared to the patients without definite and probable ST, patients with definite and probable ST were older, had more unstable angina, lower LVEF, and more left main bifurcation lesions (63.2 +/- 8.9 vs. 56.8 +/- 10.9 yrs; P = 0.049, 100% vs. 64.7%; P = 0.018, 50.6 +/- 9.9 vs. 60.3 +/- 12.4%; P = 0.019 and 70.0% vs. 36.1%; P = 0.043). Logistic analysis results indicated that only LVEF (OR 0.92, 95% CI 0.87-0.93; P = 0.017) was associated with definite and probable ST. CONCLUSIONS: The present study indicates that modern 2-DES technique for bifurcation lesions was comparatively safe with a low incidence of ST.

[Comparison of outcomes after transradial intervention in patients of different age groups].

OBJECTIVE: To compare the in-hospital clinical outcome of patients with coronary artery disease in different age groups [< 65 years (younger), 60 to 79 years (older), and ≥ 80 years (octogenarians)] underwent transradial intervention (TRI) so asto analyze the predictors of adverse events. METHOD: From May 2004 to May 2009, a total of 16 293 patients underwent transradial intervention at our institution. The in-hospital outcome for patients in different age groups after TRI was investigated. Multivariable logistic regression analysis was performed to determinate the predictors of in-hospital major adverse cardiac events (MACE) (composed of death, myocardial infarction or target vessel revascularization). RESULTS: Angiographic success rates were not different (97.5%, 97.4%, 98.1%, P > 0.05) between 3 groups. However, the rates of procedural complications became progressively higher with age group (0.8%, 1.2%, 4.0%, P < 0.01). In-hospital MACE (1.3% vs 2.2% vs 7.5%, P < 0.01) and mortality (0.1% vs 0.3% vs 2.9%, P < 0.01) increased incrementally with age group. Aad it was associated with a significant decrement of DES (92.0%, 89.6%, 57.3%, P < 0.01). The following characteristics were identified as independent multivariate predictors of in-hospital major adverse cardiac events: age ≥ 80 (OR 6.26, 95%CI: 3.33 to 11.74; P < 0.01), prior myocardial infarction (OR 2.19, 95%CI: 1.66 to 2.88; P < 0.01), left main lesion (OR 2.02, 95%CI: 1.04 to 3.91; P = 0.04), age of 65 to 79 (OR 1.83, 95%CI: 1.37 to 2.43; P < 0.01), number of implanted stents (OR 1.31, 95%CI: 1.15 to 1.50; P < 0.01), total stented length (OR 1.01, 95%CI: 1.01 to 1.02; P = 0.03), and use of DES (OR 0.59, 95%CI: 0.39 to 0.89; P = 0.01). CONCLUSIONS: The younger and older patients undergoing TRI have a more favorable in-hospital outcome. However the octogenarians has a substantially higher risk of in-hospital MACE.

[Clinical characteristics and outcome comparison between young (< or = 45 years) female and male patients with coronary artery disease undergoing percutaneous coronary intervention].

OBJECTIVE: To compare the clinical characteristics and clinical outcomes in young (< / = 45 years) female and male coronary artery disease (CAD) patients undergoing percutaneous coronary intervention (PCI). METHODS: Angiographic and clinical data from 124 premenopausal female patients who underwent elective PCI from April 2004 to February 2008 were compared to age-matched 430 male patients who underwent elective PCI between 2006 and 2007 in our department. All patients were treated according to guidelines and coronary angiography was repeated after 6 months. One year clinical follow-up were performed in all patients. RESULTS: Incidences of dyslipidemia, the history of myocardial infarction and smoking were significantly lower in female patients than in male patients (all P < 0.01). Left main, left anterior descending and bifurcation lesions were more common while type C lesion and right coronary lesion were less common in young female CAD group compared to young male CAD group (P < 0.01-0.05). The average lesion length in female patients was significantly longer than that in male patients [(20.36 +/- 13.37) mm vs. (23.04 +/- 13.86) mm, P < 0.05]. The in-hospital and follow-up incidences of major adverse cardiac events, stent thrombosis and in-stent restenosis were similar between young female and male CAD patients. CONCLUSIONS: CAD risk factors were less and vessel lesions were more likely to be found at left main, left anterior descending and bifurcation in young female CAD patients compared to young male CAD patients. The clinical outcomes were similar between young female and male CAD patients.

Efficient Selection Scheme for Incorporating Noncanonical Amino Acids Into Proteins in Saccharomyces cerevisiae.

With the advances in the field of expanded genetic code, the application of non-canonical amino acid (ncAA) is considered an effective strategy for protein engineering. However, cumbersome and complicated selection schemes limit the extensive application of this technology in Saccharomyces cerevisiae. To address this issue, a simplified selection scheme with confident results was developed and tested in this study. Based on a mutation library derived from Escherichia coli tyrosyl-tRNA synthetase (EcTyrRS), a logic gate in synthetic biology was used to optimize screening procedures. We found that an "and" gate was more suitable than an "or" gate for isolating aminoacyl-tRNA synthetase from S. cerevisiae. The successful incorporation of O-methyltyrosine (OMeY) proved the utility and efficiency of this new selection scheme. After a round of positive selection, several new OMeY-tRNA synthetase (OMeYRS) mutants were screened, and their incorporation efficiency was improved. Furthermore, we characterized the insertion of several tyrosine analogs into Herceptine Fab and discovered that OMeYRS and its mutants were polyspecific. One of these mutants showed an optimal performance to incorporate different ncAAs into recombinant proteins in S. cerevisiae; this mutant was cloned and transfected into mammalian cells, and the results proved its functionality in HEK293 cells. This study could expand the application of ncAA in S. cerevisiae to construct efficient yeast cell factories for producing natural and synthetic products.

Thermophilic Pyrrolysyl-tRNA Synthetase Mutants for Enhanced Mammalian Genetic Code Expansion.

Genetic code expansion (GCE) is a powerful technique for site-specific incorporation of noncanonical amino acids (ncAAs) into proteins in living cells, which is achieved through evolved aminoacyl-tRNA synthetase mutants. Stability is important for promoting enzyme evolution, and we found that many of the evolved synthetase mutants have reduced thermostabilities. In this study, we characterized two novel pyrrolysyl-tRNA synthetases (PylRSs) derived from thermophilic archaea: Methanosarcina thermophila (Mt) and Methanosarcina flavescens (Mf). Further study demonstrated that the wild-type PylRSs and several mutants were orthogonal and active in both Escherichia coli and mammalian cells and could thus be used for GCE. Compared with the commonly used M. barkeri PylRS, the wild-type thermophilic PylRSs displayed reduced GCE efficiency; however, some of the mutants, as well as some chimeras, outperformed their mesophilic counterparts in mammalian cell culture at 37 °C. Their better performance could at least partially be attributed to the fact that these thermophilic synthetases exhibit a threshold of enhanced stability against destabilizing mutations to accommodate structurally diverse substrate analogues. These were indicated by the higher melting temperatures (by 3-6 °C) and the higher expression levels that were typically observed for the MtPylRS and MfPylRS mutants relative to the Mb equivalents. Using histone H3 as an example, we demonstrated that one of the thermophilic synthetase mutants promoted the incorporation of multiple acetyl-lysine residues in mammalian cells. The enzymes developed in this study add to the PylRS toolbox and provide potentially better scaffolds for PylRS engineering and evolution, which will be necessary to meet the increasing demands for expanded substrate repertoire with better efficiency and specificity in mammalian systems.

Comparison of changes in early inflammatory markers between sirolimus- and paclitaxel-eluting stent implantation.

BACKGROUND: Systemic inflammation after coronary intervention identifies patients at increased risk of subsequent cardiac events. Cardiac events, especially in-stent restenosis, are less frequent after use of sirolimus-eluting stent (SES) compared with paclitaxel-eluting stent (PES). However, the underlying mechanism for this disparity is not well investigated. We hypothesize that an attenuated inflammatory response after SES implantation may be a contributor. PURPOSE: In the present study, we sought to determine the early inflammatory response after SES implantation in patients with single-vessel disease compared with PES implantation, and evaluate the relationship between inflammatory response and late clinical outcomes in a randomized design. METHODS: Thirty-two patients with stable angina were randomly enrolled into the two groups, SES or PSE group (n = 16 respectively). Peripheral blood samples were taken before PCI, 24 and 72 h after stenting. The plasma concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) were determined by enzyme-linked immunosorbent assay (ELISA). The clinical and angiographic follow-up was performed at 8 months after stenting. RESULTS: The data showed that there was no significant difference in clinical and angiographic baseline characteristics between the two groups. The plasma CRP and IL-6 levels at 24 h after stenting were significant higher in both groups compared with baseline (p < 0.01 respectively). Likewise, the CRP levels at 72 h after stenting were also significant higher compared with baseline in both groups (p < 0.01 respectively). However, the plasma levels of IL-6 at 24 h and CRP at 72 h after stenting were higher in PES group compared with SES group (p < 0.05). At 8 months follow-up, the rates of major adverse cardiac events, target lesion revascularization, in-stent and in-segment restenosis were similar in both groups. However, the late loss in both in-stent and in-segment was significantly higher in the PES group than in SES group (p < 0.001 respectively). CONCLUSIONS: Our findings suggest that a drug-eluting stent implantation could trigger a systemic inflammatory response as previously demonstrated. However, SES implantation results in a lower inflammatory response compared with PES implantation, which seems to be associated with greater late of in-stent and in-segment loss at 8-month follow-up with PES.

[Analysis of acute myocardial infarction one month after stent implantation].

OBJECTIVE: To study the possible causes of ST-elevated acute myocardial infarction (STEAMI) occurring one month after percutaneous coronary intervention (PCI). METHODS: One hundred and ninety two patients aged from 40 - 79 years who had a successful previous PCI and also received primary PCI due to STEAMI in this hospitalization were included in this study. The AMI-related lesions and previous angiographic findings such as the number of lesions, the degree of the stenosis, the type of stents and the acute results of last PCI, etc. were recorded in detail. If the AMI-related lesion was localized in-stents or at the edge of stents (distance from the edge < or = 5 mm), it was defined as late thrombosis, otherwise it was regarded as an AMI induced by new-lesion. RESULTS: New lesions, as the cause of STEAMI, were found in 144 cases (Group A, 75%), and late thrombosis in 48 patients (Group B, 25%). There was a significant difference in the average time from previous PCI to AMI (30.1 +/- 12.4 vs. 20.3 +/- 11.9 months) between the two groups. Diabetes mellitus (DM) and drug-eluting stents (DES) utilization were associated with markedly higher morbidity of late thrombosis in adjusted logistic regression analysis [hazard ratio (HR) 3.387, 95% CI 1.053 - 10.898 and HR 5.311, 95%CI 1.066 - 26.464]. CONCLUSIONS: STEAMI occurred 1 month after PCI are more likely to be developed from previous insignificant lesions than from late thrombosis in stents. Moreover, DM and DES are associated with a high incidence of late thrombosis, which may indicate that intensive antiplatelet therapy should be considered in diabetic patients receiving PCI.