Association between triglyceride-glucose index (TyG) and the risk of new-onset stroke in middle-aged and elderly people / 公共卫生与预防医学

Objective The high incidence, disability, and mortality rates of stroke result in a heavy economic and social burden. The aim of this study was to investigate the relationship between triglyceride-glucose (TyG) index and new-onset stroke to assist in the identification of high-risk groups for stroke and to provide ideas for effective prevention. Methods The study was based on data from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2018 and included 7630 eligible middle-aged and elderly participants. The association between TyG index and new-onset stroke was assessed by logistic regression modelling and restricted triple spline analysis. Results A total of 431 participants had a new stroke. The TyG index was found to be a risk factor for stroke occurrence when it was >8.523, and there was a positive linear association moderated by gender. Conclusion Elevated TyG index is a risk factor for new stroke. This study provides new ideas for the identification of high-risk groups for stroke and for intervention measures and timing.

Click chemistry-based enrichment strategy for tracing cellular fatty acid metabolism by LC-MS/MS / 药物分析学报

Fatty acids(FAs),which were initially recognized as energy sources and essential building blocks of biomembranes,serve as the precursors of important signaling molecules.Tracing FA metabolism is essential to understanding the biochemical activity and role of FAs in physiological and pathological events.Inspired by the advances in click chemistry for protein enrichment,we herein established a click chemistry-based enrichment(CCBE)strategy for tracing the cellular metabolism of eicosapentaenoic acid(EPA,20:5 n-3)in neural cells.Terminal alkyne-labeled EPA(EPAA)used as a surrogate was incubated with N2a,mouse neuroblastoma cells,and alkyne-labeled metabolites(ALMs)were selectively captured by an azide-modified resin via a Cu(I)-catalyzed azide-alkyne cycloaddition reaction for enrichment.After removing unlabeled metabolites,ALMs containing a triazole moiety were cleaved from solid-phase resins and subjected to liquid chromatography mass spectrometry(LC-MS)analysis.The proposed CCBE strategy is highly selective for capturing and enriching alkyne-labeled metabolites from the complicated matrices.In addition,this method can overcome current detection limits by enhancing MS sensitivity of targets,improving the chromatographic separation of sn-position glycerophospholipid regioisomers,facilitating structural characterization of ALMs by a specific MS/MS fragmentation signature,and providing versatile fluorescence detection of ALMs for cellular distribution.This CCBE strategy might be expanded to trace the metabolism of other FAs,small molecules,or drugs.

Profile and gene functional analysis of gut microbiota in women with postmenopausal osteoporosis / 中华微生物学和免疫学杂志

Objective:To explore the profile and gene functional changes of gut microbiota (GM) in women with postmenopausal osteoporosis (PMOP) in Northwest China, and the correlations between GM and bone mineral density (BMD).Methods:From November 2018 to October 2019, postmenopausal women were screened on their initial visits to our hospital, and 24 new osteoporosis (OP) patients, 30 new osteopenia patients and nine negative controls were recruited. Fecal samples were collected for GM DNA extraction, and Illumina platforms were used for high-throughput sequencing of 16S rRNA and metagenome. Species annotation, GM profile and gene functions were viewed and analyzed.Results:GM profiles were significatly different in different groups, and the LDA scores of Peptostreptococcaceae, Romboutsia, unidentified Clostridiales, Megamonas, Erysipelatoclostridium, Klebsiella and Erysipelatoclostridium ramosum were more than 3 in OP group. Metagenomic sequencing analysis indicated that gene numbers were positively correlated with BMD, and metabolism, carbohydrate metabolism, starch and sucrose metabolism and oxidative phosphorylation were negatively correlated with BMD. Receiver operating characteristic curve(ROC) showed that carbohydrate metabolism, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, oxidative phosphorylation, respectively, could identify OP with preferable sensitivity and specificity (areas under curve were 0.70, 0.72, 0.73 and 0.75, respectively). Conclusions:High-throughput sequencing had great potential for GM analysis of postmenopausal women with OP, providing evidence of the correlations between GM and BMD.

Characteristics of Visual Evoked Potential in Different Parts of Visual Impairment / 法医学杂志

OBJECTIVES@#To study the quantitative and qualitative differences of visual evoked potential (VEP) in monocular visual impairment after different parts of visual pathway injury.@*METHODS@#A total of 91 subjects with monocular visual impairment caused by trauma were selected and divided into intraocular refractive media-injury group (eyeball injury group for short), optic nerve injury group, central nervous system injury and intracranial combined injury group according to the injury cause and anatomical segment. Pattern Reversal visual evoked potential (PR-VEP) P100 peak time and amplitude, Flash visual evoked potential (F-VEP) P2 peak time and amplitude were recorded respectively. SPSS 26.0 software was used to analyze the differences of quantitative (peak time and amplitude) and qualitative indexes (spatial frequency sweep-VEP acuity threshold, and abnormal waveform category and frequency) of the four groups.@*RESULTS@#Compared with healthy eyes, the PR-VEP P100 waveforms of the intraocular eyeball injury group and the F-VEP P2 waveforms of the optic nerve group showed significant differences in prolonged peak time and decreased amplitude in injured eyes (P<0.05). The PR-VEP amplitudes of healthy eyes were lower than those of injured eyes at multiple spatial frequencies in central nervous system injury group and intracranial combined injury group (P<0.05).The amplitude of PR-VEP in patients with visual impairment involving central injury was lower than that in patients with eye injury at multiple spatial frequencies. The frequency of VEP P waveforms reaching the threshold of the intraocular injury group and the optic nerve injury group were siginificantly different from the intracranial combined injury group, respectively(P<0.008 3), and the frequency of abnormal reduction of VEP amplitude of threshold were significantly different from the central nervous system injury group, respectively(P<0.008 3).@*CONCLUSIONS@#VEP can distinguish central injury from peripheral injury, eyeball injury from nerve injury in peripheral injury, but cannot distinguish simple intracranial injury from complex injury, which provides basic data and basis for further research on the location of visual impairment injury.

Reversal of Social Recognition Deficit in Adult Mice with MECP2 Duplication via Normalization of MeCP2 in the Medial Prefrontal Cortex / 神经科学通报·英文版

Methyl-CpG binding protein 2 (MeCP2) is a basic nuclear protein involved in the regulation of gene expression and microRNA processing. Duplication of MECP2-containing genomic segments causes MECP2 duplication syndrome, a severe neurodevelopmental disorder characterized by intellectual disability, motor dysfunction, heightened anxiety, epilepsy, autistic phenotypes, and early death. Reversal of the abnormal phenotypes in adult mice with MECP2 duplication (MECP2-TG) by normalizing the MeCP2 levels across the whole brain has been demonstrated. However, whether different brain areas or neural circuits contribute to different aspects of the behavioral deficits is still unknown. Here, we found that MECP2-TG mice showed a significant social recognition deficit, and were prone to display aversive-like behaviors, including heightened anxiety-like behaviors and a fear generalization phenotype. In addition, reduced locomotor activity was observed in MECP2-TG mice. However, appetitive behaviors and learning and memory were comparable in MECP2-TG and wild-type mice. Functional magnetic resonance imaging illustrated that the differences between MECP2-TG and wild-type mice were mainly concentrated in brain areas regulating emotion and social behaviors. We used the CRISPR-Cas9 method to restore normal MeCP2 levels in the medial prefrontal cortex (mPFC) and bed nuclei of the stria terminalis (BST) of adult MECP2-TG mice, and found that normalization of MeCP2 levels in the mPFC but not in the BST reversed the social recognition deficit. These data indicate that the mPFC is responsible for the social recognition deficit in the transgenic mice, and provide new insight into potential therapies for MECP2 duplication syndrome.

Three new bioactive flavonoid glycosides from Viscum album / 中国天然药物

Two new flavonoid glycosides, named viscumneoside XII (1), and viscumneoside XIII (2); a new dihydrogen flavonoid glycoside product named viscumneoside XIV (3), were isolated from the aerial part of Viscum album, along with seven known compounds (4-10). Their structures were identified by analysis of spectroscopic data. In addition, cytotoxicity assay showed that 1, 2 and 3 possessed significant inhibitory activities against C6, A549 and MDA-MB-231 (the inhibition rate arrived about 50%, 70% and 74% respectively with IC ≤ 60.00 μmol·L), while the inhibition of TF-1 and Hela was not significant.

Two symmetrical unsaturated acids isolated from Viscum album / 中国天然药物

In the present study, two new acetylene conjugate compounds, dibutyl (2Z, 6Z)-octa-2, 6-dien-4-yne dioate (1), and dibutyl (2E, 6E)- octa-2, 6-dien-4-yne dioate (2), were isolated from the dry stem leaves of Viscum album, along with nine known compounds (3 - 11). Their structures were confirmed on the basis of spectroscopic data. Compounds 1 and 8 showed antioxidant activity against xanthine oxidase (XOD) and 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydroxyl (DPPH), with the IC of 1.22 and 1.33 μmol·L, and the SC of 4.34 and 8.22 μmol·L, respectively.

Super-Resolution Track-Density Imaging Reveals Fine Anatomical Features in Tree Shrew Primary Visual Cortex and Hippocampus / 神经科学通报·英文版

Diffusion-weighted magnetic resonance imaging (dMRI) is widely used to study white and gray matter (GM) micro-organization and structural connectivity in the brain. Super-resolution track-density imaging (TDI) is an image reconstruction method for dMRI data, which is capable of providing spatial resolution beyond the acquired data, as well as novel and meaningful anatomical contrast that cannot be obtained with conventional reconstruction methods. TDI has been used to reveal anatomical features in human and animal brains. In this study, we used short track TDI (stTDI), a variation of TDI with enhanced contrast for GM structures, to reconstruct direction-encoded color maps of fixed tree shrew brain. The results were compared with those obtained with the traditional diffusion tensor imaging (DTI) method. We demonstrated that fine microstructures in the tree shrew brain, such as Baillarger bands in the primary visual cortex and the longitudinal component of the mossy fibers within the hippocampal CA3 subfield, were observable with stTDI, but not with DTI reconstructions from the same dMRI data. The possible mechanisms underlying the enhanced GM contrast are discussed.

Expression of Arabidopsis thaliana thioesterase gene in Pichia pastoris / 生物工程学报

Thioesterase catalyzes the hydrolysis of acyl-ACP and saturated fatty acyl chain. It plays a key role in the accumulation of medium chain fatty acids in vivo. In this study, to construct an engineering strain to produce MCFAs, the Arabidopsis acyl-ACP thioesterase gene AtFatA was amplified by PCR from cDNA of arabidopsis and double digested by EcoR I/Xba I, then linked to the plasmid digested with same enzymes to get the recombinant plasmid pPICZaA-AtFatA. We transformed the gene into Pichia pastoris GS115 by electroporation and screened positive colonies by YPD medium with Zeocin. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results showed that the recombinant enzyme had a molecular of 45 kDa band which was consistent with the predicted molecular mass and we constructed the expression system of gene AtFatA in fungus for the first time. Under shake-flask conditions, Gas Chromatograph-Mass Spectrometer-computer results indicated that recombinant strain produced 51% more extracellular free MCFAs than the wild and its yield reached 28.7% of all extracellular fatty acids. This figure is 10% higher than the control group. The result provides a new way to produce MCFAs.

Dosimetric comparison between helical tomotherapy and intensity-modulated radiation therapy plans for non-small cell lung cancer / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Helical tomotherapy (HT) is a new image-guided intensity-modulated radiation therapy (IMRT) technique. It is reported that HT plan for non-small-cell lung cancer (NSCLC) can give better dose uniformity, dose gradients, and protection for the lung than IMRT plan. We compared the dosimetric characteristics of HT for NSCLC with those of conventional IMRT to observe the superiority of HT.</p><p><b>METHODS</b>There was a comparative case series comprising 10 patients with NSCLC. Computed tomographic (CT) images of delineated targets were transferred to the PrecisePlan planning system (IMRT) and Tomo planning system (HT). The prescription doses were 70 Gy/33F for the gross tumor volume (GTV) and the visible lymph nodes (GTVnd), and 60 Gy/33F for the clinical target volume (CTV) and the clinical target volume of the visible lymph nodes (CTVnd). The dose restrictions for organs at risk were as follows: the maximum dose to spinal cord ≤ 45 Gy, V20 to the total lungs < 30%, V50 to the heart < 50%, and V55 to the esophagus < 50%. Both plans were evaluated by means of the dose coverage of the targets, dose-volume histograms (DVHs), and other dosimetric indices.</p><p><b>RESULTS</b>The dose coverage, conformity, and homogeneity of the targets' volumes were found to be satisfactory in both plans, but the homogeneity of the HT plan was better than that of IMRT. The high-dose radiation volume (V20-V30) to the lung and the mean lung dose (MLD) decreased (P < 0.05), but the low-dose radiation volume (V5-V10) increased slightly in the HT plan (P > 0.05). The maximum doses to the spinal cord, heart, esophagus and trachea in the HT plan were lower than those in the IMRT plan, but the differences were not statistically significant.</p><p><b>CONCLUSIONS</b>The HT plan provids better dose uniformity, dose gradients, and protection for the organs at risk. It can reduce the high-dose radiation volume for lung and the MLD, but may deliver a larger lung volume of low-dose radiation.</p>

Culture Methods of the Oligotrophic Marine Microbes / 微生物学通报

Molecular methods and fluoroscopic techniques suggest that rich microbial diversity exist in the marine environment, but less than 1% of these microbes can be cultured in the laboratory conditions, and that the cultivable dominant species were even less. This limitation has long been a barrier to the development of environmental microbiology and the utilization of marine resources. In the past decade, novel methods for culture and detection of these uncultured marine microbes have successfully applied to obtain several conventionally-uncultured microbes including those from extreme environments. Those progresses have inspired researchers greatly. Developments in the research of marine microbial resources are an important basis for the study of the micro-world and deserve increasing scientific attention.

Verification of accuracy of multileaf collimator leaf position using a two-dimensional ion chamber array / 中华放射肿瘤学杂志

Objective To design a new method to verify the position of multileaf collimator(MLC)leaf using a two-dimensional ion chamber array(2D-array).Methods 2D-array of PTW T10018 Seven29~(TM) was used to calibrate the accuracy of MLC leaf position of Elekta Precise accelerator.The edge function of the leaf position of MLC was measured and used as the reference value.The precision of MLC leaf was then evaluated through comparing the measured and reference values.Results The accuracy of MLC leaf position was found within?0.1 mm.Conclusion This method of verifying the accuracy of multileaf collimator leaf position is easy,simple and reliable