The role of mitochondria in myocardial damage caused by energy metabolism disorders: From mechanisms to therapeutics.

Myocardial damage is the most serious pathological consequence of cardiovascular diseases and an important reason for their high mortality. In recent years, because of the high prevalence of systemic energy metabolism disorders (e.g., obesity, diabetes mellitus, and metabolic syndrome), complications of myocardial damage caused by these disorders have attracted widespread attention. Energy metabolism disorders are independent of traditional injury-related risk factors, such as ischemia, hypoxia, trauma, and infection. An imbalance of myocardial metabolic flexibility and myocardial energy depletion are usually the initial changes of myocardial injury caused by energy metabolism disorders, and abnormal morphology and functional destruction of the mitochondria are their important features. Specifically, mitochondria are the centers of energy metabolism, and recent evidence has shown that decreased mitochondrial function, caused by an imbalance in mitochondrial quality control, may play a key role in myocardial injury caused by energy metabolism disorders. Under chronic energy stress, mitochondria undergo pathological fission, while mitophagy, mitochondrial fusion, and biogenesis are inhibited, and mitochondrial protein balance and transfer are disturbed, resulting in the accumulation of nonfunctional and damaged mitochondria. Consequently, damaged mitochondria lead to myocardial energy depletion and the accumulation of large amounts of reactive oxygen species, further aggravating the imbalance in mitochondrial quality control and forming a vicious cycle. In addition, impaired mitochondria coordinate calcium homeostasis imbalance, and epigenetic alterations participate in the pathogenesis of myocardial damage. These pathological changes induce rapid progression of myocardial damage, eventually leading to heart failure or sudden cardiac death. To intervene more specifically in the myocardial damage caused by metabolic disorders, we need to understand the specific role of mitochondria in this context in detail. Accordingly, promising therapeutic strategies have been proposed. We also summarize the existing therapeutic strategies to provide a reference for clinical treatment and developing new therapies.

[Distribution and Removal of Antibiotic Resistance Genes in Two Sequential Wastewater Treatment Plants].

Wastewater treatment plants (WWTPs) have been regarded as important point-sources of antibiotic resistance genes (ARGs) in aquatic environments. To investigate the distribution and removal of ARGs in WWTPs, a pharmaceutical wastewater treatment plant (PWWTP) and an integrated wastewater treatment plant (IWWTP) in a fine-chemical industrial park were chosen, and polymerase chain reaction (PCR) and real-time PCR techniques were used to determine the occurrence and abundances of ARGs along the treatment processes. Ten and fifteen ARGs were detected initially in the influents of PWWTP and IWWTP respectively, in which tetracycline and sulfonamide resistance genes were frequently reported, while dfrA13 was first reported in WWTPs. The most abundant ARGs in the influents were sul Ⅰ and sul Ⅱ, followed by dfrA13, tetQ, floR, tetO, and tetW. The total ARGs increased by 0.21 log after the treatment by PWWTP, whose effluent contributed 0.87% to the inflow yet 5.05% to the total ARGs of IWWTP. Finally the total ARGs removed by IWWTP was 1.03 log, with the remaining ARGs then transported within the final effluent to the nearby coastal area. The authors concluded that the environmental and other impacts from the spread of ARGs on the microbial communities of the coastal environment needed further study.

Rice straw pretreatment using deep eutectic solvents with different constituents molar ratios: Biomass fractionation, polysaccharides enzymatic digestion and solvent reuse.

Lignocellulosic biomass pretreatment with deep eutectic solvents (DESs) is a promising and challenging process for production of biofuels and valuable platform chemicals. In this work, rice straw was mainly fractionated into carbohydrate-rich materials (CRMs) and lignin-rich materials (LRMs) by 90% lactic acid/choline chloride (LC)-water solution with different molar ratio of hydrogen bond donor (HBD, lactic acid) and hydrogen bond acceptor (HBA, choline chloride). It was found that high HBD/HBA molar ratio of DESs was favorable for achieving CRMs and LRMs with high purity, and both HBD and HBA were responsible for effective biomass fractionation possibly due to their synergistic effect on highly efficient breakage of the linkage between hemicellulose and lignin and thus lignin extraction. About 30%-35% of lignin in native rice straw was fractionated as LRMs, and exceeding 70% of xylan were removed and fractionated into the liquid stream as forms of xylose, furfural and humins after pretreatment using aqueous LC (3:1, 5:1) solution. Consequently, polysaccharides enzymatic hydrolysis of the CRMs were significantly enhanced. Moreover, all the DESs could be recovered with high yields of around 90%, and 69% of the LC (3:1) was recovered after 5 cycles reuse at 90 °C. Besides, the recycled DES maintained a good pretreatment ability, and glucose yields of 60-70% were achieved in the enzymatic hydrolysis of CRMs obtained in each cycle. The facile process established in present work is promising for large scale production of fermentable sugars and other chemicals.

Insight into the structure-function relationships of deep eutectic solvents during rice straw pretreatment.

Rice straw pretreatment mediated by choline chloride (ChCl) or lactic acid (Lac) sequences deep eutectic solvents (DESs) was investigated in this work. Hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) proved to be both important for DESs pretreatment efficiency. DESs containing lots of hydroxyl or amino groups with a high intermolecular hydrogen-bond (H-bond) strength exhibited weak biomass deconstruction abilities. The presence of strong electron-withdrawing groups in DESs was benefit for xylan removal, thus furnishing higher cellulose digestibility. The relationships between the properties of DESs, xylan removal and cellulose digestibility of pretreated biomass were established. It was found that xylan removal was negatively correlated with the pKa values of HBDs, and the enzymatic cellulose digestibility of the residues was linearly and positively related to xylan removal instead of delignification. These results provide a preliminary reference for rational design of novel DESs for biomass pretreatment.

Is fusion superior to non-fusion for the treatment of thoracolumbar burst fracture? A systematic review and meta-analysis.

OBJECTIVE: The purpose of this meta-analysis was to compare the efficacy and safety between patients with thoracolumbar burst fracture who underwent posterior fixation alone (non-fusion) and supplemented with fusion. METHODS: A comprehensive search of related literature was performed in PubMed, Embase and the Cochrane library. Clinical outcomes (LBOS and VAS), surgical outcomes (operation time, blood loss, hospital stay and perioperative complications), and radiographic outcomes (kyphotic angle, decreased vertebral body height and segmental motion) were assessed in the meta-analysis. Data analysis was conducted with RevMan 5.3 software. RESULTS: Five RCTs and three retrospective studies including a total of 445 cases were identified. We found that there was no significant difference in terms of LBOS, VAS, implant-related complications, kyphotic and VBH parameters. However, there was a significant difference regarding blood loss, operation time, segmental motion and donor site pain between fusion and non-fusion. CONCLUSION: This meta-analysis demonstrated that posterior fixation alone could achieve satisfactory clinical and radiological results in treating thoracolumbar burst fracture. Moreover, posterior fixation without fusion was superior to additional fusion with less blood loss, shorter operation time, better segmental motion and lower donor site pain.

[Abundance of Cell-associated and Cell-free Antibiotic Resistance Genes in Two Wastewater Treatment Systems].

For revealing the characteristics of antibiotic resistance genes (ARGs) in wastewater treatment systems, real-time PCR was adopted to investigate the variation of abundances of cell-associated ARGs and cell-free ARGs, in a municipal wastewater treatment system (M for short) and a coking wastewater treatment system (C for short). In system M, the absolute abundances of the cell-associated ARGs, sul Ⅱ,tetC,blaPSE-1, and ermB, were much higher than those of the cell-free fractions in the influent. The biological treatment process did not enrich antibiotic resistance bacteria (ARBs) and membrane filtration of the MBR effectively reduced both cell-associated and cell-free DNA in water. The total ARGs removal was 2.54-4.95 logs. In system C, the biological treatment process enriched the sul Ⅱ -carried ARBs; however, the relative and absolute abundances of cell-free sul Ⅱ were decreased. The succeeding process, coagulation-sand filtration, decreased the absolute abundance of cell-associated sul Ⅱ, but increased the absolute abundance of cell-free sul Ⅱ in water. The proportion of cell-free sul Ⅱ in total sul Ⅱ gene increased from 0.05% in the biological treatment effluent to 1.33% in the sand filtration effluent and further increased to 9.31% after the effluent was kept at 25℃ and at dark for five days. The ratio of cell-free ARGs to total ARGs increased with deep removal of ARBs and lysis of residual cells. The risk of ARG proliferation by cell-free DNA in the effluent needs further evaluation.