Magnetic resonance imaging focused on the ferritin heavy chain 1 reporter gene detects neuronal differentiation in stem cells

The neuronal differentiation of mesenchymal stem cells offers a new strategy for the treatment of neurological disorders.Thus,there is a need to identify a noninvasive and sensitive in vivo imaging approach for real-time monitoring of transplanted stem cells.Our previous study confirmed that magnetic resonance imaging,with a focus on the ferritin heavy chain 1 reporter gene,could track the proliferation and differentiation of bone marrow mesenchymal stem cells that had been transduced with lentivirus carrying the ferritin heavy chain 1 reporter gene.However,we could not determine whether or when bone marrow mesenchymal stem cells had undergone neuronal differentiation based on changes in the magnetic resonance imaging signal.To solve this problem,we identified a neuron-specific enolase that can be differentially expressed before and after neuronal differentiation in stem cells.In this study,we successfully constructed a lentivirus carrying the neuron-specific enolase promoter and expressing the ferritin heavy chain 1 reporter gene;we used this lentivirus to transduce bone marrow mesenchymal stem cells.Cellular and animal studies showed that the neuron-specific enolase promoter effectively drove the expression of ferritin heavy chain 1 after neuronal differentiation of bone marrow mesenchymal stem cells;this led to intracellular accumulation of iron and corresponding changes in the magnetic resonance imaging signal.In summary,we established an innovative magnetic resonance imaging approach focused on the induction of reporter gene expression by a neuron-specific promoter.This imaging method can be used to noninvasively and sensitively detect neuronal differentiation in stem cells,which may be useful in stem cell-based therapies.

Effect of temperature on heavy ion-induced single event transient on 16-nm FinFET inverter chains

The variations of single event transient(SET)pulse width of high-LET heavy ion irradiation in 16-nm-thick bulk silicon fin field-effect transistor(Fin FET)inverter chains with different driven strengths are measured at different temperatures.Three-dimensional(3D)technology computer-aided design simulations are carried out to study the SET pulse width and saturation current varying with temperature.Experimental and simulation results indicate that the increase in temperature will enhance the parasitic bipolar effect of bulk Fin FET technology,resulting in the increase of SET pulse width.On the other hand,the increase of inverter driven strength will change the layout topology,which has a complex influence on the SET temperature effects of Fin FET inverter chains.The experimental and simulation results show that the device with the strongest driven strength has the least dependence on temperature.

Mutation of Arg723Gly in β-myosin heavy chain gene in five Chinese families with hypertrophic cardiomyopathy

Background Hypertrophic cardiomyopathy （HCM） is a form of cardiomyopathy with an autosomal dominant inherited disease, which is caused by mutations in at least one of the sarcomeric protein genes. Mutations in the beta-myosin heavy chain （β-MHC） are the most common cause of HCM. This study was to reveal the disease-causing gene mutations in Chinese population with HCM, and to analyze the correlation between the genotype and phenotype. Methods The exons 3 to 26 of MYH7 were amplified by PCR, and the PCR products were sequenced in five non-kin HCM patients. A 17-year-old patient was detected to be an Arg723Gly mutation carrier. Then his family was gene-screened, and the correlation between genotype and phenotype was analyzed. Results The mutation of Arg723Gly in a Chinese family with HCM was detected for the first time. With a C-G transversion in nucleotide 13 619 of the MYH7 gene, located at the essential light chain interacting region in S1, the replacement of arginine by glycine took place at amino acid residue 723. A two-dimensional echocardiogram showed moderate asymmetrical septal hypertrophy with left atria enlargement. There was no obstruction in the left ventricular outflow tract. In his family, a total of 13 individuals were diagnosed HCM and 5 of them were dead of congestive heart failure at a mean age of 66-year-old. Eight living members were all detected to carry the mutation, in which 3 developed progressive heart failure. Moreover, the heart function of the people evidently deteriorates when their age are older than 50. The mutation and the disease show co-separated. Conclusion The Arg723Gly mutation is a malignant type. In Chinese the mutation has the similar characters to the former report but has low degree malignant.

HMG CoA reductase inhibition by Simvastatin gets rat <i>β</i>-Myosin heavy chain disappeared: A statin paradox

3-hydroxy-3methylglutaryl Coenzyme A reductase, the rate limiting enzyme of mevalonate pathway, generates, in addition to cholesterol, a range of products involved in several biological functions: oligoprenyl groups, dolichol and ubiquinone. The latter, in particular, participates in electron transport chain and, in turn, in tissue energy supply. The enzyme is inhibited by statins that, besides lowering cholesterolemia, seem to impair human energy-dependent myocardial functions (e.g. stroke volume, cardiac output, and contractile index). The modulation of heart contractile properties could be explained by the decrease of ventricle ubiquinone content and/or by putative changes in proportion of the different myosin heavy chain isoforms. Since we previously demonstrated that chronic statin treatment modifies myosin heavy chain isoform pattern in skeletal muscle impairing its functional properties, this work was aimed at investigating the effects of statin chronic treatment on both ventricle ubiquinone content and myosin heavy chain isoforms. Our results showed that simvastatin treatment leads to a reduced amount of rat ventricle ubiquinone and to β myosin heavy chain disappearance. Thus, statins which are prescribed to prevent cardiovascular disease, might induce cardiac metabolic and structural modifications whose functional implications on contractility are still to be established and carefully considered.

磁性Fe_3O_4纳米颗粒对大鼠脏器组织中Caveolin-1和Clathrin Heavy Chain蛋白表达的影响

目的:探讨磁性Fe_3O_4纳米颗粒对大鼠主要脏器组织中Caveolin-1及Clathrin Heavy Chain蛋白表达的影响,阐明其作用机制。方法:将24只Wistar大鼠按体质量随机分成对照组和低、中、高剂量磁性Fe_3O_4纳米颗粒组,尾静脉注射不同剂量磁性Fe_3O_4纳米颗粒24h后取脏器组织,Western blotting法检测大鼠主要脏器组织中Caveolin-1及Clathrin Heavy Chain蛋白的表达水平,荧光实时定量PCR法检测大鼠主要脏器组织中Caveolin-1及Clathrin Heavy Chain mRNA的表达水平。结果:与对照组比较,中和高剂量组大鼠肝脏和脾脏组织中Clathrin Heavy Chain蛋白和mRNA表达水平明显升高(P<0.05)。高剂量组大鼠肾脏组织中Clathrin Heavy Chain mRNA的表达水平与其他3组比较明显升高(P<0.05)。Caveolin-1蛋白表达水平在各剂量组之间比较差异无统计学意义(P>0.05);与对照组比较,低、中和高剂量组大鼠肝脏、肺脏和脾脏组织中Caveolin-1mRNA表达水平明显升高(P<0.05);各组肾脏组织中Caveolin-1 mRNA表达水平差异无统计学意义(P>0.05)。结论:磁性Fe_3O_4纳米颗粒能够诱导大鼠肝脏、肺脏、脾脏中Clathrin Heavy Chain蛋白表达增强,通过Clathrin Heavy Chain蛋白的内吞作用是磁性Fe_3O_4纳米颗粒进入大鼠肝脏、肺脏和脾脏细胞的途径之一。

Biotransfer of heavy metals along a soil-plant-insect-chicken food chain:Field study

The accumulation and transfer of Pb,Zn,Cu,and Cd along a soil-plant-insect-chicken food chain at contaminated sites were investigated.The study site nearing the Pb/Zn mine had been contaminated by heavy metals severely.Cadmium and Pb concentrations steadily declined with increasing trophic level（p 〈 0.01）,but concentrations of Zn and Cu slightly increased from plant to insect larva（p 〉 0.05）.The concentrations of heavy metals were the highest in chicken muscle,with lower values in liver and blood.The bioaccumulation of Pb was observed in chicken livers.The eliminations of Pb,Zn,Cu,and Cd via insect and chicken feces avoid metal bioaccumulation in insect and chicken body.These results suggest that the accumulation of heavy metals in specific animal organ of tissues could not be neglected,although transfer of metals to chicken from plant and insect was limited.

Clonal immunoglobulin heavy chain and T-cell receptor γ gene rearrangements in primary gastric lymphoma

AIM:To study the diagnostic value of immunoglobulin heavy chain(IgH)and T-cell receptorγ (TCR-γ)gene monoclonal rearrangements in primary gastric lymphoma(PGL).METHODS:A total of 48 patients with suspected PGL at our hospital were prospectively enrolled in this study from January 2009 to December 2011.The patients were divided into three groups(a PGL group,a gastric linitis plastica group,and a benign gastric ulcer group)based on the pathological results(gastric mucosal specimens obtained by endoscopy or surgery)and follow-up.Endoscopic ultrasonography(EUS)and EUSguided biopsy were performed in all the patients.The tissue specimens were used for histopathological examination and for IgH and TCR-γ gene rearrangement polymerase chain reaction analyses.RESULTS:EUS and EUS-guided biopsy were successfully performed in all 48 patients.In the PGL group(n=21),monoclonal IgH gene rearrangements were detected in 14(66.7%)patients.A positive result for each set of primers was found in 12(57.1%),8(38.1%),and 4(19.0%)cases using FR1/JH,FR2/JH,and FR3/JH primers,respectively.Overall,12(75%)patients with mucosal-associated lymphoid tissue lymphoma(n=16)and 2(40%)patients with diffuse large B-cell lymphoma(n=5)were positive for monoclonal IgH gene rearrangements.No patients in the gastric linitis plastica group(n=17)and only one(10%)patient in the benign gastric ulcer group(n=10)were positive for a monoclonal IgH gene rearrangement.No TCRgene monoclonal rearrangements were detected.The sensitivity of monoclonal IgH gene rearrangements was 66.7%for a PGL diagnosis,and the specificity was96.4%.In the PGL group,8(100%)patients with stage IIE PGL(n=8)and 6(46.1%)patients with stage IE PGL(n=13)were positive for monoclonal IgH gene rearrangements.CONCLUSION:IgH gene rearrangements may be associated with PGL staging and may be useful for the diagnosis of PGL and for differentiating between PGL and gastric linitis plastica.

Induction of Cardiomyocyte Apoptosis by Anti-Cardiac Myosin Heavy Chain Antibodies in Patients with Acute Myocardial Infarction

Autoimmune is involved in the pathogenesis of ventricular remodeling in acute myocardial infarction (AMI).In the present study, we investigated the effect of anti-cardiac myosin heavy chain antibodies (AMHCA) from patients with AMI on rat cardiomyocyte apoptosis.Cardiomyocyte apoptosis was observed and measured by DNA end labeling and Annexin-Ⅴ/PI double-staining assay.The expression of apoptosis related p53 and Bcl-2 protein and the second messenger calcium were detected respectively by Western blotting, patch clamp and confocal calcium imaging.The results showed that AMHCA was able to induce cardiomyocyte apoptosis in a dose dependent manner.Apoptosis-accelerating nucleoprotein p53 was up-regulated, while apoptosis-inhibiting cytoplasmic protein Bcl-2 was down-regulated.In parallel, cytoplasmic calcium concentration was elevated.There was no effect on L-type calcium currents.It is concluded that AMHCA in patients with AMI as a novel triggering factor can induce cardiomyocyte apoptosis, which contributes to ventricular remodeling.

Molecular cloning and mRNA expression analysis of myosin heavy chain(MyHC)from fast skeletal muscle of grass carp,Ctenopharyngodon idella

The myosin heavy chain(MyHC)is one of the major structural and contracting proteins of muscle.We have isolated the cDNA clone encoding MyHC of the grass carp,Ctenopharyngodon idella. The sequence comprises 5 934 bp,including a 5 814 bp open reading frame encoding an amino acid sequence of 1 937 residues.The deduced amino acid sequence showed 69%homology to rabbit fast skeletal MyHC and 73%–76%homology to the MyHCs from the mandarin fish,walleye pollack,white croaker,chum salmon,and carp.The putative sequences of subfragment-1 and the light meromyosin region showed 61.4%–80%homology to the corresponding regions of other fish MyHCs.The tissue-specific and developmental stage-specific expressions of the MyHC gene were analyzed by quantitative real-time PCR.The MyHC gene showed the highest expression in the muscles compared with the kidney,spleen and intestine.Developmentally,there was a gradual increase in MyHC mRNA expression from the neural formation stage to the tail bud stage.The highest expression was detected in hatching larva.Our work on the MyHC gene from the grass carp has provided useful information for fish molecular biology and fish genomics.

Effect of aerobic exercise on the contractile function of gastrocnemius myosin heavy chain

Objective To study the effect of 4-6 weeks’ treadmill training of male SD rats on the contractile function of their gastrocnemius myosin heavy chain (MHC). Methods Forty male SD rats were randomly divided into control group and training group. The treadmill training of the training group rats was incessantly performed for 4-6 weeks at an intensity of about 75% VO2max (18.5-24 m/min,gradient of 0°,each training session lasting 50 minutes,twice a day). The content of gastrocnemius MHC mRNA was tested by reverse transcription polymerase chain reaction (RT-PCR),and the changes of muscle fibre and its cross-section area (CSA) were measured using immunohistochemistry. Electric stimulation tests were used to determine the maximal tension of isometric contraction of the post-training gastrocnemius. Results ① After continuous treadmill training for 4-6 weeks,we found that the content of the total MHC,MHC Ⅰ,MHC Ⅱx,MHC Ⅱa mRNAs was 105%,105%,109% and 108% of that in the resting control group,respectively,and the MHC Ⅱb mRNA content did not change significantly. The percentage of MHC Ⅰ mRNA in the total MHC mRNA increased while that of MHC Ⅱ mRNA decreased after aerobic training. ② The slow type of fibre type Ⅰ was the main part of the MHC after training and the CSA of the muscle fibres increased simultaneously. ③ The maximal tension of isometric contraction by pulse stimulation of square wave in the training group increased significantly compared with that in the control group (P<0.01). Conclusion The findings indicate that aerobic exercise may promote an increase in the contractile function of MHC.

Agaro-Oligosaccharides Prevent Myostatin Hyperexpression and Myosin Heavy Chain Protein Degradation in C2C12 Myotubes Induced by Tumor Necrosis Factor-<i>α</i>

Myostatin is a major factor involved in the regulation of skeletal muscle protein mass. High myostatin levels have been associated with an increase in myotube shrinkage. Enhanced myostatin expression is caused by pro-catabolic reactions involving compounds such as tumor necrosis factor (TNF)-α. The present study investigated the effects of agaro-oligosaccharides (AOSs) on hypercatabolism of myotubes exposed to TNF-α. C2C12 myotubes exposed to TNF-α in the presence or absence of AOSs. Myotube exposure to TNF-α resulted in a reduction in the amount of myosin heavy chain (MyHC) protein and a decrease in myotube diameter, which was associated with increased myostatin mRNA expression. AOSs prevented TNF-α-induced MyHC protein loss and restored normal myostatin mRNA levels, with agarobiose and agarotetraose effectively suppressing the hyperexpression of the mRNA. In addition, expression levels of the known myostatin inhibitors, latent transforming growth factor beta binding protein 3 (Ltbp3) and growth and differentiation factor-associated serum protein 1 (Gasp1) mRNAs, decreased more in TNF-α-induced myotubes than in the TNF-α-free control, possibly resulting in myostatin upregulation. However, AOSs restored nearly normal expression levels of Ltbp3 and Gasp1 mRNA, potentially suppressing myostatin expression. These findings suggest that AOSs could prevent myotube shrinkage induced by TNF-α.

Isolation and Characterization of Recombinant Variable Domain of Heavy Chain Anti-idiotypic Antibodies Specific to Aflatoxin B_1

Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain （VHH）. The recombinant VHHs have a high potential as alternative reagents for the next generation of immunoassay. In particular, they might be very useful for molecular mimicry. The present study demonstrated an alpaca immunized with the F（ab＇）z fragment of anti-aflatoxin B1 mAb and developed an important anti-idiotypic （anti-ld） responses. Antigen-specific elution method was used for panning private anti-ld VHHs from the constructed alpaca VHH library. The selected VHHs were expressed, renatured, purified, and then identified by a competitive enzyme-linked immunosorbent assay （ELISA）. Our findings indicated that the VHH would be an alternative tool for haptens mimicry studies.

CHARACTERIZATION OF THE β－MYOSIN HEAVY CHAIN GENE MISSENSE MUTATIONIN A CHINESE PATINENT WITH HYPERTROPHIC CARDIOMYOPHTHY

We have analyzed the exons 13, 16, 21 and 23 of cardiac myosin heavy chain gene in 32 Chinese patients with hypertrophic cardiomyopathy by using PCR-single strand conformation polymorphism (PCR-SSCP) procedure. The result showed an altered SSCP of the exon 13 in one patient. Sequencing analysis revealed that the patient had a G to T transversion in the codon 383, resulting in the substitution of Lys by Asn. Beacause the missense mutation was found at the residue highly conserved through species evolution, this mutation is likely, to be the cause of hypertrophic cardiomyopathy in this patient. This is the first report of a mutant cardiac β-MHC gene in the Chinese population. Also, it is a novel missense mutation of the cardiac β-MHC gene.

Study on the Prediction Method of the First Heavy Rain in the Spring of Xi'an City Based on Markov Chain

[Objective] The aim was to study the Markov chain prediction method of first heavy rain in spring in Xi’an City.[Method] According to the dependent random variables of the occurrence of heavy rain,precipitation in spring in seven meteorological stations in Xi’an City from 1959 to 2010 was selected.Its occurrence date was determined by the standard of first heavy rain in spring in meteorology.According to the length of the sequence of the problem and actual situation,six states were divided.And by dint of Markov chain,first heavy rain prediction model in spring was set up.[Result] The predicted occurrence time of first heavy rain in spring in Xi’an in 2009 and 2010 was consistent with the actual situation.The prediction effect was fine.The method had clear thought and was convenient for calculation,with certain dependence and practicality.[Conclusion] This method provided reference value for the actual forecast of first heavy rain in spring.

Cloning, sequencing and analyzing of the heavy chain V region genes of human polyreactive antibodies

The heavy chain variable region genes of 5 human polyreactive mAbs generated in our laboratory have been cloned and sequenced using polymerase chain reaction (PCR) technique. We found that 2 and 3 mAbs utilized genes of the VHIV and VHIII families, respectively. The former 2 VH segments were in germline configuration. A common VH segment, with the best similarity of 90.1 % to the published VHIII germline genes, was utilized by 2 different rearranged genes encoding the V regions of other 3 mAbs. This strongly suggests that the common VH segment is a unmutated copy of an unidentified germline VHIII gene. All these polyreactive mAbs displayed a large NDN region (VH-D-JH junction). The entire H chain V regions of these polyreactive mAbs are unusually basic. The analysis of the charge properties of these mAbs as well as those of other poly- and mono- reactive mAbs from literatures prompts us to propose that the charged amino acids with a particular distribution along the H chain V region,especially the binding sites (CDRs), may be an important structural feature involved in antibody polyreactivity.

Rare Case of a Patient Presenting with Parathyroid Hormone-Related Peptide Mediated Hypercalcemia and IgG Heavy Chain Disease: Case Report and Review of Literature

IgG Heavy Chain Disease (γHCD) is a rare plasma cell disorder. Hypercalcemia related to plasma cell dyscrasias is related to non-PTHrP related mechanisms. Here we describe the first case of a patient with γHCD and PTHrP related hypercalcemia. Methods: Patient case derived from chart review from 2011 to 2015. Literature review performed searching PubMed 1968-current. Results: The patient was diagnosed with hypercalcemia with elevated PTHrP and exclusion of other etiologies of hypercalcemia. She was diagnosed with (γHCD) by M-spike 0.64 g/dL, IFE showing a broad band of IgG heavy chain, without associated light chains and severe depression of the non-mono-clonal IgG. Serum immunoglobulins demonstrated elevated IgG (2110 mg/dL), normal IgA (46 mg/dL) and decreased IgM (<21 mg/dL). Bone marrow biopsy showed 5% PCs, non-clonal by kappa/lambda, but exclusive for IgG by IHC, without any staining for IgA or IgM. The patient was started on therapy with improved hypercalcemia and PTHrP levels. Conclusions: This is the first reported case of γHCD presenting with PTHrP related hypercalcemia. Given that skeletal involvement is uncommon in γHCD, hypercalcemia secondary to γHCD may at times be a PTHrP driven phenomenon and we recommend that this test be ordered in such cases.

血清LncRNA FAF、ITIH4在慢性心力衰竭患者中的表达意义及对预后的预测价值

目的探讨血清长链非编码RNA(LncRNA)FAF、间α胰蛋白酶抑制因子重链4(ITIH4)在慢性心力衰竭(CHF)患者中的表达意义及对预后的预测价值。方法选择2020年1月—2022年1月安徽医科大学第二附属医院急诊内科收治的CHF患者187例为CHF组,再根据NYHA心功能分级分为Ⅱ级亚组65例,Ⅲ级亚组77例,Ⅳ级亚组45例。于同期招募健康志愿者103例为健康对照组。2组受试者均检测血清LncRNA FAF表达和ITIH4水平,CHF患者出院后随访12个月,统计随访期间主要不良心血管事件(MACE)发生率;多因素Logistic回归分析影响CHF患者发生MACE的因素;受试者工作特征(ROC)曲线分析LncRNA FAF、ITIH4预测CHF患者发生MACE的价值。结果CHF组血清LncRNA FAF表达、ITIH4水平低于健康对照组(t/P=24.469/<0.001、35.196/<0.001)。血清LncRNA FAF表达、ITIH4水平Ⅳ级亚组低于Ⅲ级亚组低于Ⅱ级亚组(F/P=91.653/<0.001、102.345/<0.001)。MACE亚组血清LncRNA FAF表达,ITIH4水平低于非MACE亚组(t/P=13.556/<0.001、6.293/<0.001)。NYHAⅣ级、高水平NT-proBNP是CHF患者发生MACE的危险因素[OR(95%CI)=4.627(2.245~9.538)、2.284(1.505~3.468)],高表达LncRNA FAF、高水平ITIH4是保护因素[OR(95%CI)=0.599(0.425~0.844)、0.666(0.478~0.928)]。LncRNA FAF、ITIH4及二者联合预测CHF患者发生MACE的曲线下面积为0.796、0.801、0.896,二者联合预测曲线下面积高于单独预测(Z=2.453、2.404,均P<0.001)。结论CHF患者血清LncRNA FAF表达和ITIH4水平均降低,且与不良预后有关,联合LncRNA FAF和ITIH4可预测CHF患者预后不良风险。

MYH7基因c.1574A>G突变致扩张型心肌病1S型家系分析

目的 采用全外显子组测序分析1例左心系统扩张患儿的基因变异情况,并进行家系分析,确认扩张型心肌病1S型(DCMIS)的病因。方法 收集1例左心系统扩张患儿的临床资料。采用染色体拷贝数变异测序(CNV-seq)检测患儿染色体结构缺失和重复情况。采用全外显子组测序分析患儿基因变异情况,采用Sanger测序对患儿及其父母、异卵双生姐姐变异位点进行验证。通过生物信息学分析评估变异位点的危害性。结果 患儿心脏彩色多普勒超声示左心功能降低,左心系统明显扩张增大,肺动脉高压,二尖瓣和三尖瓣反流。CNV-seq结果为seq[hg19]46,XN,未发现染色体异常。全外显子组测序分析结果显示,患儿β-心肌肌肉球蛋白重链7(MYH7)基因发生杂合变异[c.1574A>G(p.Glu525Gly)]。检索OMIM、ClinVar数据库,未见相关报道;检索ESP数据库、千人基因组数据库、ExAC数据库和gnomAD数据库,该变异位点未被收录,属于新发变异。Sanger测序证实变异存在,患儿父母、姐姐MYH7基因均正常。MYH7基因c.1574A>G(p.Glu525Gly)变异导致蛋白侧链O端与第484位赖氨酸侧链N端之间形成的氢键侧链相互作用消失。结论 c.1574A>G(p.Glu525Gly)为新发现的MYH7基因变异,是造成患儿左心系统明显扩张的原因。新发变异的检出丰富了DCMIS致病机制研究数据。

基于试验模拟的滑坡泥石流灾害链风险监测预警

[目的]开展以元阳梯田滑坡泥石流地质灾害链为基础的风险监测预警研究,为改善降雨诱发型滑坡泥石流灾害链的预警精度,提高防灾减灾工作针对性提供科学依据。[方法]采用降雨模型模拟试验来探讨元阳梯田滑坡—泥石流灾害链破坏过程,通过对降雨量、体积含水率和坡体变形破坏过程进行实时监测,分析不同降雨条件下灾害链风险预警阈值。试验设置长时间中雨(50 mm/h)、长时间暴雨(120 mm/h)、循环间歇暴雨和干旱突发型暴雨4种降雨工况。[结果]在降雨持续作用下,灾害链发展过程为:地表冲刷、蠕滑、快速滑动、泥石流运移及运移结束。坡体破坏最先从左侧坡脚开始,右侧坡脚稍后。不同降雨工况下坡体破坏形式不同:暴雨工况下坡体中部会产生一条横向裂缝,而形成上下两个滑块;中雨工况下坡体则陆续形成多个滑块;干旱突发暴雨工况下泥石流形成时间最短,运移距离最远,流通和堆积范围相比其他降雨工况更广。[结论]滑坡泥石流灾害链预警监测指标主要为累积降雨量、降雨持续时间、含水率变化和坡体变形发展现场监测。这些监测参数受降雨条件、土体性质、坡角和外部动力条件等诸多因素影响,因此在实际应用中需要综合考虑这些因素。

LINC00852调节miR-671-5p/MYH9信号轴对非小细胞肺癌细胞增殖侵袭及迁移的影响

目的:探讨长链非编码RNA00852(LINC00852)调节微小RNA-671-5p(miR-671-5p)/肌球蛋白重链9(MYH9)信号轴对非小细胞肺癌(NSCLC)细胞增殖、侵袭及迁移的影响。方法:采用qRT-PCR法检测45例2022年9月至2023年12月期间在我院进行手术的NSCLC患者术中切除的NSCLC组织及癌旁组织中LINC00852、miR-671-5p、MYH9 mRNA的表达。以A549细胞为研究对象,将其随机分为Control组、sh-NC组、sh-LINC00852组、sh-LINC00852+anti-NC组、sh-LINC00852+anti-miR-671-5p组。检测各组中LINC00852、miR-671-5p、MYH9 mRNA的表达;平板克隆实验、Transwell实验、划痕实验分别检测敲低LINC00852对A549细胞的增殖、侵袭、迁移的影响;Western blot检测各组A549细胞中PCNA、MYH9、MMP-9蛋白的表达。双荧光素酶报告基因实验检测LINC00852与miR-671-5p、miR-671-5p与MYH9之间的互作。结果:NSCLC组织LINC00852(1.65±0.34)、MYH9 mRNA表达(1.73±0.35)高于癌旁组织[(0.98±0.29)、(1.01±0.33)](t=10.058、10.041,P<0.05),miR-671-5p表达(0.52±0.15)低于癌旁组织(1.00±0.18)(t=13.742,P<0.05)。sh-LINC00852组A549细胞的克隆数、侵袭数、划痕愈合率、LINC00852、MYH9 mRNA和蛋白、PCNA蛋白、MMP-9蛋白表达低于sh-NC组、Control组,miR-671-5p表达高于sh-NC组、Control组(P<0.05);与sh-LINC00852组、sh-LINC00852+anti-NC组相比,sh-LINC00852+anti-miR-671-5p组克隆数、侵袭数、划痕愈合率、MYH9 mRNA和蛋白、PCNA蛋白、MMP-9蛋白表达升高,miR-671-5p表达降低(P<0.05)。LINC00852可以靶向负调控miR-671-5p,miR-671-5p可以靶向负调控MYH9。结论:敲低LINC00852可以抑制NSCLC细胞的增殖、侵袭、迁移,其机制可能是通过调控miR-671-5p/MYH9信号通路实现的。