Clinical value of combined plasma brain natriuretic peptide and serum cystatin C measurement on the prediction of heart failure in patients after acute myocardial infarction.

This research investigated the predictive value of combined detection of brain natriuretic peptide (BNP) and cystatin C (Cys C) in heart failure after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). Sixty-five AMI patients complicated by heart failure (HF) after PCI and 79 non-heart failure (non-HF) patients were involved in this research. The levels of Cys C and BNP were measured. Risk factors for heart failure in AMI patients after PCI were analyzed by multivariate logistic regression analysis. Efficacy of BNP and Cys C on predicting heart failure were analyzed by receiver operating characteristic (ROC) curve. Cys C and BNP levels were significantly higher in the HF group than in the non-HF group. BNP and Cys C levels were the independent influencing factors causing heart failure within one year after PCI. The area under the predicted curve (AUC) of Cys C, BNP, and combined Cys C and BNP were 0.763, 0.829, and 0.893, respectively. The combined detection of Cys C and BNP was highly valuable in predicting heart failure in AMI patients after PCI, which can be regarded as the serum markers for diagnosis and treatment of heart failure.

Improving Theaflavin-3,3'-digallate Production Efficiency Optimization by Transition State Conformation of Polyphenol Oxidase.

Theaflavins (TFs) are good for health because of their bioactivities. Enzymatic synthesis of TFs has garnered much attention; however, the source and activity of the enzymes needed limit their wide application. In this study, a microbial polyphenol oxidase from Bacillus megaterium was screened for the synthesis of theaflavin-3,3'-digallate (TFDG). Based on structural and mechanistic analyses of the enzyme, the O-O bond dissociation was identified as the rate-determining step. To address this issue, a transition state (TS) conformation optimization strategy was adopted to stabilize the spatial conformation of the O-O bond dissociation, which improved the catalytic efficiency of tyrosinase. Under the optimum transformation conditions of pH 4.0, temperature 25 °C, (-)-epigallocatechin gallate/epicatechin gallate molar ratio of 2:1, and time of 30 min, Mu4 (BmTyrV218A/R209S) produced 960.36 mg/L TFDG with a 44.22% conversion rate, which was 6.35-fold higher than that of the wild type. Thus, the method established has great potential in the synthesis of TFDG and other TFs.

Rational Design of Meso-Diaminopimelate Dehydrogenase with Enhanced Reductive Amination Activity for Efficient Production of d-p-Hydroxyphenylglycine.

d-p-hydroxyphenylglycine (d-HPG) is an important intermediate in the pharmaceutical industry. In this study, a tri-enzyme cascade for the production of d-HPG from l-HPG was designed. However, the amination activity of Prevotella timonensis meso-diaminopimelate dehydrogenase (PtDAPDH) toward 4-hydroxyphenylglyoxylate (HPGA) was identified as the rate-limiting step. To overcome this issue, the crystal structure of PtDAPDH was solved, and a "binding pocket and conformation remodeling" strategy was developed to improve the catalytic activity toward HPGA. The best variant obtained, PtDAPDHM4, exhibited a catalytic efficiency (kcat/Km) that was 26.75-fold higher than that of the wild type. This improvement was due to the enlarged substrate-binding pocket and enhanced hydrogen bond networks around the active center; meanwhile, the increased number of interdomain residue interactions drove the conformation distribution toward the closed state. Under optimal transformation conditions, PtDAPDHM4 produced 19.8 g/L d-HPG from 40 g/L racemate DL-HPG in a 3 L fermenter within 10 h, with 49.5% conversion and >99% enantiomeric excess. Our study provides an efficient three-enzyme cascade pathway for the industrial production of d-HPG from racemate DL-HPG. IMPORTANCE d-p-hydroxyphenylglycine (d-HPG) is an important intermediate in the synthesis of antimicrobial compounds. d-HPG is mainly produced via chemical and enzymatic approaches, and enzymatic asymmetric amination employing diaminopimelate dehydrogenase (DAPDH) is considered an attractive method. However, the low catalytic activity of DAPDH toward bulky 2-keto acids limits its applications. In this study, we identified a DAPDH from Prevotella timonensis and created a mutant, PtDAPDHM4, which exhibited a catalytic efficiency (kcat/Km) toward 4-hydroxyphenylglyoxylate that was 26.75-fold higher than that of the wild type. The novel strategy developed in this study has practical value for the production of d-HPG from inexpensive racemate DL-HPG.

A Tri-Enzyme Cascade for Efficient Production of L-2-Aminobutyrate from L-Threonine.

L-2-aminobutyrate (L-ABA) is an important chiral drug intermediate with a key role in modern medicinal chemistry. Here, we describe the development of an efficient method for the asymmetric synthesis of L-ABA in a tri-enzymatic cascade in Escherichia coli BL21 (DE3) using a cost-effective L-Thr. Low activity of leucine dehydrogenase from Bacillus thuringiensis (BtLDH) and unbalanced expression of enzymes in the cascade were major challenges. Mechanism-based protein engineering generated the optimal triple variant BtLDHM3 (A262S/V296C/P150M) with 20.7-fold increased specific activity and 9.6-fold increased kcat /Km compared with the wild type. Optimizing plasmids with different copy numbers regulated enzymatic expression, thereby increasing the activity ratio (0.3 : 1:0.6) of these enzymes in vivo close to the optimal ratio (0.4 : 1 : 1) in vitro. Importing the optimal triple mutant BtLDHM3 into our constructed pathway in vivo and optimization of transformation conditions achieved one-pot conversion of L-Thr to 130.2 g/L L-ABA, with 95 % conversion, 99 % e.e. and 10.9 g L-1 h-1 productivity (the highest to date) in 12 h on a 500 mL scale. These results describe a potential biosynthesis approach for the industrial production of L-ABA.

Efficient production of salvianic acid A from L-dihydroxyphenylalanine through a tri-enzyme cascade.

Salvianic acid A (SAA), used for treating cardiovascular and cerebrovascular diseases, possesses several pharmacological properties. However, the current methods for the enzymatic synthesis of SAA show low efficiency. Here, we constructed a three-enzyme cascade pathway in Escherichia coli BL21 (DE3) to produce SAA from L-dihydroxyphenylalanine (L-DOPA). The phenylpyruvate reductase (LaPPR) from Lactobacillus sp. CGMCC 9967 is a rate-limiting enzyme in this process. Therefore, we employed a mechanism-guided protein engineering strategy to shorten the transfer distances of protons and hydrides, generating an optimal LaPPR mutant, LaPPRMu2 (H89M/H143D/P256C), with a 2.8-fold increase in specific activity and 9.3-time increase in kcat/Km value compared to that of the wild type. Introduction of the mutant LaPPRMu2 into the cascade pathway and the optimization of enzyme levels and transformation conditions allowed the obtainment of the highest SAA titer (82.6 g L-1) ever reported in vivo, good conversion rate (91.3%), excellent ee value (99%) and the highest productivity (6.9 g L-1 h-1) from 90 g L-1 L-DOPA in 12 h. This successful strategy provides a potential new method for the industrial production of SAA.

Clinical value of combined plasma brain natriuretic peptide and serum cystatin C measurement on the prediction of heart failure in patients after acute myocardial infarction

This research investigated the predictive value of combined detection of brain natriuretic peptide (BNP) and cystatin C (Cys C) in heart failure after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). Sixty-five AMI patients complicated by heart failure (HF) after PCI and 79 non-heart failure (non-HF) patients were involved in this research. The levels of Cys C and BNP were measured. Risk factors for heart failure in AMI patients after PCI were analyzed by multivariate logistic regression analysis. Efficacy of BNP and Cys C on predicting heart failure were analyzed by receiver operating characteristic (ROC) curve. Cys C and BNP levels were significantly higher in the HF group than in the non-HF group. BNP and Cys C levels were the independent influencing factors causing heart failure within one year after PCI. The area under the predicted curve (AUC) of Cys C, BNP, and combined Cys C and BNP were 0.763, 0.829, and 0.893, respectively. The combined detection of Cys C and BNP was highly valuable in predicting heart failure in AMI patients after PCI, which can be regarded as the serum markers for diagnosis and treatment of heart failure.

Evaluation and Analysis of Design Elements for Sustainable Renewal of Urban Vulnerable Spaces.

The sustainable renewal design of urban vulnerable spaces is critical for urban space quality improvement. Taking Zhengzhou and surrounding cities as examples, a cognitive framework of urban vulnerable spaces is constructed. The three types of urban vulnerable spaces are vulnerable population, vulnerable cultural, and vulnerable forgotten spaces. Their sustainable renewal design elements comprise multidimensional factors, such as functional requirement, space organization, activity facility, urban context continuation, and material texture. The design elements for the sustainable update of urban vulnerable spaces are evaluated by grey relation analysis (GRA), and update strategies are proposed. The result shows that (1) vulnerable population spaces were shown to have the highest sensitivity to functional requirements and activity facility design elements, while vulnerable cultural spaces have high relevance to urban context continuation and functional requirement design elements. Furthermore, space organization, activity facility, and urban context continuation design elements all show high relevance and importance in vulnerable forgotten spaces. (2) The update of vulnerable population spaces should be designed to achieve functional communion; vulnerable cultural spaces can be reshaped through urban context implantation, and vulnerable forgotten spaces can use space creation to enhance ecological space continuity, achieving sustainable renewal. The study provides a reference for decision-making for improving urban vulnerable habitats and the sustainable renewal design of atypical urban space types.

Short-term efficacy of ticagrelor in acute ST-segment elevation myocardial infarction patients undergoing an emergency percutaneous coronary intervention.

In total, 97 acute ST-segment elevation myocardial infarction (STEMI) patients who received an emergency percutaneous coronary intervention (PCI) were enrolled and divided into a ticagrelor group and a clopidogrel group. Thrombolysis in myocardial infarction (TIMI) blood flow and the corrected TIMI frame count (CTFC) were used to assess the blood perfusion of culprit vessels. Thromboelastography (TEG) was used to evaluate the antiplatelet effect of drugs. The results showed that the incidence of TIMI grade III blood flow in the ticagrelor group was significantly higher than that in the clopidogrel group. The CTFC in the anterior descending, circumflex, and right coronary arteries was statistically significantly lower in the ticagrelor group as compared with that in the clopidogrel group. At 2 h and 7 d postdrug treatment, the adenosine diphosphate-induced platelet inhibition rate (ADP%) in the ticagrelor group increased significantly as compared with that in the clopidogrel group, and the platelet aggregation rate of the ADP pathway (MAADP) decreased significantly in the ticagrelor group versus that in the clopidogrel group. In conclusion, ticagrelor significantly improved TIMI blood flow and had a better antiplatelet effect than clopidogrel in STEMI patients undergoing an emergency PCI.

Comparison of the Effects of Ticagrelor and Clopidogrel on Inflammatory Factors, Vascular Endothelium Functions and Short-Term Prognosis in Patients with Acute ST-Segment Elevation Myocardial Infarction Undergoing Emergency Percutaneous Coronary Intervention: a Pilot Study.

BACKGROUND/AIMS: Acute ST-segment elevation of myocardial infarction (STEMI) is the most severe type of acute coronary syndrome (ACS). Particular attention has been focused on studying the pathogenesis of STEMI, and how to prevent thrombosis, reduce inflammatory reaction, stabilize plaques and improve vascular endothelial functions to preserve the survived myocardium. This study aimed to compare the anti-inflammatory endothelium-protective effects, clinical prognosis, and relevant bleeding risks of ticagrelor versus clopidogrel in patients with STEMI who underwent urgent percutaneous coronary intervention (PCI) and provide certain experimental evidence and a theoretical basis for the selection of safe and effective drugs and their proper dosage, thereby further guiding clinical medication. METHODS: We sequentially enrolled 193 patients (104 males and 89 females) admitted to hospital due to acute STEMI. These patients underwent urgent PCI between December 2013 and May 2015 and met the inclusion criteria. They were assigned (1: 1) into two groups according to different treatments, 97 patients in the ticagrelor group (treatment group), and 96 patients in the clopidogrel group (control group). Levels of hypersensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6), and endothelial cell-specific molecule 1 (ESM-1) taken at admission and 24 h, 4 days, and 7 days after administration, as well as the correlation between the levels of IL-6, hs-CRP, and ESM-1, were determined in the two groups. At the same time, the effects of treatment with ticagrelor and clopidogrel on the efficacy endpoint events (ischemic and safety) were explored. RESULTS: No statistically significant difference was found in the levels of hs-CRP, IL-6, or ESM-1 at admission between the two groups (P> 0.05); Their levels were significantly elevated 24 h after administration, with statistical differences between two groups (P< 0.05). Furthermore, a downward trend with statistically significant differences was found on Day 4 and Day 7 (P< 0.05); ESM-1 levels increased along with increases of hs-CRP and IL-6 levels, indicating ESM-1 was positively correlated with hs-CRP (r=0.523, P< 0.001) and IL-6 (r=0.431, P< 0.001); and the occurrence rates of ischemic endpoint events at 30 days were lower in the treatment group than in the control group. The occurrence of safety endpoint events was higher than in the control group; however, no statistically significant difference was found (P> 0.05). CONCLUSIONS: Compared with clopidogrel, ticagrelor appears to rapidly reduce the prevalence of inflammatory reactions and stabilize the functions of vascular endothelium to improve the stability of atherosclerotic plaque and decrease the occurrence rate of thrombosis as well as ischemic outcome events without any obvious increase in the risk of bleeding in patients with acute STEMI receiving urgent PCI. This renders it a potential drug for clinical practice. At the same time, measurement of ESM-1, a new biological marker for vascular endothelial function disorder, could possibly become a simple, effective, and practical new method for clinical evaluation of risk stratification of patients with acute STEMI at admission.

Asiatic acid inhibits lactate-induced cardiomyocyte apoptosis through the regulation of the lactate signaling cascade.

The lactate signaling cascade has recently been linked to mitochondrial energy metabolism and cardiomyocyte apoptosis in several cardiovascular diseases. Asiatic acid (AA) exhibits a variety of pharmacological effects, including antioxidant and anti-apoptotic effects. In this study, we investigated the protective effects of AA against the lactate-induced apoptosis of cardiomyocytes, as well as its mechanisms of action. Neonatal rat cardiomyocytes were pre-treated with 20 µM AA for 24 h, followed by exposure to 20 mM lactate for a further 24 h. Cell viability was determined by a cell counting kit-8 (CCK-8) assay. Cell apoptosis, reactive oxygen species (ROS) levels and mitochondrial membrane potential (Δψm) were evaluated by flow cytometry or fluorescence microscopy. The expression levels of mitochondrial monocarboxylate transporter 1 (MCT1) and cytoplasmic cytochrome c, cleaved caspase-9 and caspase-3 were assayed by western blot analysis. Our results revealed that AA significantly inhibited lactate-induced apoptosis, intracellular ROS generation and the loss of Δψm. AA also increased the expression of mitochondrial MCT1 and reduced the expression of cytoplasmic cytochrome c, cleaved caspase-9 and caspase-3 in the lactate-stimulated cardiomyocytes. To the best of our knowledge, our data demonstrate for the first time that AA plays a cytoprotective role in lactate-induced apoptosis by regulating the lactate signaling cascade, involving the inhibition of oxidative stress and mitochondria-dependent caspase activation, as well as the upregulation of mitochondrial MCT1 expression.

The relationship between functional capacity (FC) and cardiovascular risk factors (CVRFs) in senile patients after noncardiac surgery.

The aim of the present study was to investigate the relationship between the number of cardiovascular risk factors (CVRFs) and functional capacity (FC) in the senile patients undergone noncardiac surgery. One hundred and eighty-two senile patients scheduled for elective noncardiac surgery were selected. According to the Duke activity status index (DASI), the FC of each patient was evaluated, and also their CVRFs were recorded. According to the number of CVRFs, the patients were ranked into different groups. The significant differences in FC between the groups(') were identified using the analysis of variance. The examination showed that FC decreased with the increasing number of CVRFs. As a conclusion, we emphasize that with the increasing number of CVRFs, the FC of senile patients, i.e., their metabolic equivalents (METs) decrease. The occurrence of low FC and higher CVRFs is a common phenomenon in senile patients.