Inhibition of microRNA-29b suppresses oxidative stress and reduces apoptosis in ischemic stroke

MicroRNAs(miRNAs) regulate protein expression by antagonizing the translation of mRNAs and are effective regulators of normal nervous system development, function, and disease. Micro RNA-29 b(mi R-29 b) plays a broad and critical role in brain homeostasis. In this study, we tested the function of mi R-29 b in animal and cell models by inhibiting mi R-29 b expression. Mouse models of middle cerebral artery occlusion were established using the modified Zea-Longa suture method. Prior to modeling, 50 nmol/kg mi R-29 b antagomir was injected via the tail vein. Mi R-29 b expression was found to be abnormally increased in ischemic brain tissue. The inhibition of mi R-29 b expression decreased the neurological function score and reduced the cerebral infarction volume and cell apoptosis. In addition, the inhibition of mi R-29 b significantly decreased the malondialdehyde level, increased superoxide dismutase activity, and Bcl-2 expression, and inhibited Bax and Caspase3 expression. PC12 cells were treated with glutamate for 12 hours to establish in vitro cell models of ischemic stroke and then treated with the mi R-29 antagomir for 48 hours. The results revealed that mi R-29 b inhibition in PC12 cells increased Bcl-2 expression and inhibited cell apoptosis and oxidative damage. These findings suggest that the inhibition of mi R-29 b inhibits oxidative stress and cell apoptosis in ischemic stroke, producing therapeutic effects in ischemic stroke. This study was approved by the Laboratory Animal Care and Use Committee of the First Affiliated Hospital of Zhengzhou University(approval No. 201709276 S) on September 27, 2017.     

肺结核患者痰标本采集的研究进展

肺结核的诊断是以病原学(包括细菌学和分子生物学)检查结果为主,而病原学检查敏感性受痰标本质量影响。痰标本质量与采集时间、采集方法等有关。本文综述了肺结核患者痰标本采集时间、采集方法及干预措施,为提高肺结核患者病原学检出率提供参考。     

A Review of Research on Mechanical Properties and Durability of Concrete Mixed with Wastewater from Ready-Mixed Concrete Plant

The wastewater from ready-mixed concrete plants is currently being recycled as concrete mixing water. It has attracted significant attention from the construction industry and researchers since it promotes sustainable development through environmental protection, energy-saving, and emissions reduction. This article review first introduces the nature of wastewater in ready-mixed concrete plants in different regions. Then the effects of solid content in water on various properties of concrete, including working performance, durability and microscopic properties, are reviewed, respectively, when concrete is mixed with wastewater instead of tap water. Furthermore, the microscopic mechanism of action in concrete mixing with wastewater is discussed, and future work is recommended. This review provides fundamentals on the study of the properties of concrete after wastewater is mixed into concrete.     

Structure Based Affinity Maturation and Characterizing of SARS-CoV Antibody CR3022 against SARS-CoV-2 by Computational and Experimental Approaches

The COVID-19 epidemic is raging around the world. Neutralizing antibodies are powerful tools for the prevention and treatment of SARS-CoV-2 infection. Antibody CR3022, a SARS-CoV neutralizing antibody, was found to cross-react with SARS-CoV-2, but its affinity was lower than that of its binding with SARS-CoV, which greatly limited the further development of CR3022 against SARS-CoV-2. Therefore, it is necessary to improve its affinity to SARS-CoV-2 in vitro. In this study, the structure-based molecular simulations were utilized to virtually mutate the possible key residues in the complementarity-determining regions (CDRs) of the CR3022 antibody. According to the criteria of mutation energy, the mutation sites that have the potential to impact the antibody affinity were then selected. Then optimized CR3022 mutants with the enhanced affinity were further identified and verified by enzyme-linked immunosorbent assay (ELISA), surface plasma resonance (SPR) and autoimmune reactivity experiments. Finally, molecular dynamics (MD) simulation and binding free energy calculation (MM/PBSA) were performed on the wild-type CR3022 and its two double-site mutants to understand in more detail the contribution of these sites to the higher affinity. It was found that the binding affinity of the CR3022 antibody could be significantly enhanced more than ten times after the introduction of the S103F/Y mutation in HCDR–3 and the S33R mutation in LCDR–1. The additional hydrogen-bonding, hydrophobic interactions, as well as salt-bridges formed between the modified double-site mutated antibody and SARS-CoV-2 RBD were identified. The computational and experimental results clearly demonstrated that the affinity of the modified antibody has been greatly enhanced. This study indicates that CR3022 as a neutralizing antibody recognizing the conserved region of RBD against SARS-CoV with cross-reactivity with SARS-CoV-2, a different member in a large family of coronaviruses, could be improved by the computational and experimental approaches which provided insights for developing antibody drugs against SARS-CoV-2.     

Updated review of genetic reticulate pigmentary disorders

Reticulate pigmentary disorders are a group of disorders characterized by hyper‐ and/or hypopigmented macules with varying sizes and amounts of pigment. Some of the disorders are heritable, such as Dowling‐Degos disease, dyschromatosis universalis hereditaria, dyschromatosis symmetrica hereditaria, reticulate acropigmentation of Kitamura and X‐linked reticulate pigmentary disorder. Although each condition possesses unique phenotypic characteristics and the prognosis for each is somewhat different, there is a large degree of overlap between the disorders and therefore they are difficult to differentiate in the clinical setting. This updated review provides a clinical and molecular delineation of these genetic reticulate pigmentary disorders and aims to establish a concise diagnostic strategy to allow clinical dermatologists to make an accurate diagnosis, as well as to provide useful information for clinical and genetic counselling.     

Backscatter coefficient measurements using a reference phantom to extract depth-dependent instrumentation factors

In previous work, we demonstrated that accurate backscatter coefficient measurements are obtained with a data reduction method that explicitly accounts for experimental factors involved in recording echo data. An alternative, relative processing method for determining the backscatter coefficient and the attenuation coefficient is presented here. This method involves comparison of echo data from a sample with data recorded from a reference phantom whose backscatter and attenuation coefficients are known. A time domain processing technique is used to extract depth and frequency dependent signal ratios for the sample and the reference phantom. The attenuation coefficient and backscatter coefficient of the sample are found from these ratios. The method is tested using tissue-mimicking phantoms with known scattering and attenuation properties.     

Genetic variants in telomere-maintenance genes and bladder cancer risk

Telomere maintenance genes play an important role in maintaining the integrity of the telomere structure that protects chromosome ends, and telomere dysfunction may lead to tumorigenesis. Genetic variation in telomere maintenance genes has been confirmed. Cumulative evidence shows that the difference of telomere length and stability among the indi- vidual depends on the genetic variants of telomere maintenance genes. Genetic variants in telomere maintenance genes may affect telomere length and stability, thus the increased cancer risk. This review intends to summarize the association of genetic variants in telomere maintenance genes with bladder cancer risk.