Buxu Tongyu Granule Alleviates Myocardial Ischemia by Activating Vascular Smooth Muscle Cell Soluble Guanylate Cyclase to Inhibit Abnormal Vasomotion

Myocardial ischemia is a serious threat to human health,and vascular dysfunction is its main cause.Buxu Tongyu(BXTY)Granule is an effective traditional Chinese medicine(TCM)for treating myocardial ischemia.However,the underlying mechanism of BXTY is still unclear.In this study,we demonstrate that BXTY ameliorates myocardial ischemia by activating the soluble guanylate cyclase(sGC)-30,50-cyclic guanosine monophosphate(cGMP)-protein kinase G(PKG)signaling pathway in vascular smooth muscle cells(VSMCs)to dilate the arteries.BXTY was given by gavage for ten consecutive days before establishing an animal model of acute myocardial ischemia in mice via the intraperitoneal injection of pituitrin.The results showed that BXTY alleviated the symptoms of myocardial ischemia induced by pituitrin in mice,including electrocardiogram abnormalities and changes in plasma enzymes.In addition,BXTY dilated pre-constricted blood vessels and inhibited the vasoconstriction of the superior mesenteric artery in a dose-dependent but endothelial-independent manner.These effects were eliminated by preincubating vascular rings with the sGC inhibitors NS 2028 or ODQ,or with the PKG inhibitor KT 5823.Moreover,BXTY increased the protein expression of sGC-b1 and the intracellular second messenger cGMP level in mouse aortic vascular smooth muscle cells(MOVAs).NS 2028 or ODQ reversed these effects of BXTY.The expression level of the cGMP downstream effector protein PKG-1 increased after treating MOVAs with BXTY.NS 2028,ODQ,or KT 5823 also reversed this effect of BXTY.In conclusion,BXTY can improve the symptoms of acute myocardial ischemia in mice,and activating the sGC-cGMP-PKG pathway in VSMCs to induce vasodilation is its key pharmacodynamic mechanism.

Soluble ST2:A Novel Biomarker for Diagnosis and Prognosis of Cardiovascular Disease

The increasing incidence of cardiovascular disease(CVD)is a significant global health concern,affecting millions of individuals each year.Accurate diagnosis of acute CVD poses a formidable challenge,as misdiagnosis can significantly decrease patient survival rates.Traditional biomarkers have played a vital role in the diagnosis and prognosis of CVDs,but they can be influenced by various factors,such as age,sex,and renal function.Soluble ST2(sST2)is a novel biomarker that is closely associated with different CVDs.Its low reference change value makes it suitable for continuous measurement,unaffected by age,kidney function,and other confounding factors,facilitating risk stratification of CVDs.Furthermore,the combination of sST2 with other biomarkers can enhance diagnostic accuracy and prognostic value.This review aims to provide a comprehensive overview of sST2,focusing on its diagnostic and prognostic value as a myocardial marker for different types of CVDs and discussing the current limitations of sST2.

新型4-苯氧基吡啶类c-Met激酶抑制剂的合成和抗肿瘤活性研究

为了发现新型高活性c-Met激酶抑制剂,以2-氨基-4-氯吡啶为原料,经醚化、酰化、烷基化、还原和酰化等多步反应,制备了6种未见文献报道的4-苯氧基吡啶类化合物,化合物结构经红外光谱、核磁共振氢谱和质谱确证.生物活性测试结果显示,6种化合物对MKN-45、A549、H460和HT-294种肿瘤细胞株具有很好的抗增殖活性,两种化合物对c-Met激酶具有很好的抑制活性.其中化合物7b抑制MKN-45、A549、H460和HT-29细胞株的IC 50值分别为1.89、5.14、0.74、0.60μmol/L.该化合物在1000 nmol/L和200 nmol/L的浓度下对c-Met激酶的抑制率分别为96.2%和82.8%,显示出了优异的抗肿瘤活性.

黄芪建中汤对脾胃虚寒证胃溃疡大鼠炎症因子及HGF/c-Met信号通路的影响

目的观察黄芪建中汤对脾胃虚寒证胃溃疡大鼠炎症因子及HGF/c-Met信号通路的影响。方法将60只大鼠随机分为4组,即正常组、模型组、黄芪建中汤组[黄芪建中汤6.8 g/(kg·d)]、奥美拉唑组[奥美拉唑肠溶胶囊4.2 mg/(kg·d)],每组15只大鼠。正常组除外,其他组采用耗气破气法结合饥饱失常法进行大鼠脾胃虚寒证模型造模,再采用冰醋酸法建立大鼠胃溃疡模型。比较各组大鼠体质量、溃疡指数;HE染色观察大鼠胃组织病理学变化;采用酶联免疫吸附法检测血清中白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)含量;免疫组化法检测胃组织中肝细胞生长因子(HGF)、肝细胞生长因子受体(c-Met)表达;荧光定量PCR检测胃组织HGF、c-Met m RNA水平。结果与正常组相比,模型组大鼠体质量降低,溃疡指数升高,IL-6、IL-1β、TNF-α含量升高,HGF升高,HGF、c-Met m RNA升高(P<0.05);与模型组相比,黄芪建中汤组和奥美拉唑组大鼠体质量升高,溃疡指数降低,IL-6、IL-1β、TNF-α降低,HGF升高,HGF、c-Met mRNA升高(P<0.05)。结论黄芪建中汤可以通过抑制炎症因子、调节HGF/c-Met通路的表达促进胃黏膜修复。

基于转录组测序探究C-MET表达在非小细胞肺癌中的免疫调控机制

目的通过转录组测序技术分析C-MET表达在非小细胞肺癌中的免疫调控机制。方法使用siRNA分子干扰技术将C-MET高表达肺腺癌细胞株(H1993)、肺鳞癌细胞株(EBC-1)的C-MET表达沉默,利用转录组测序技术检测C-MET沉默前后细胞差异表达的基因(DEGs),通过生物信息学分析挖掘出C-MET可能参与调控的免疫微环境信号通路及相关基因。最后使用人免疫细胞与H1993、EBC-1共培养技术验证C-MET对免疫因子(INF-γ、INF-β、CXCL-10)的影响。结果通过转录组测序技术共检测到505个DEGs,其中H1993的C-MET调控前后表达差异组的表达差异基因共有38个,上调的差异表达基因有24个,下调的差异表达基因有14个。EBC-1的C-MET调控前后表达差异组的表达差异基因共有467个,上调的差异表达基因有347个,下调的差异表达基因121个。差异基因的KEGG分析表明,C-MET表达可能通过白细胞介素(IL-17)信号通路、白细胞分化、细胞因子受体活性、细胞周期、细胞因子-细胞因子受体相互作用参与免疫细胞调节因子的调控。使用肺癌细胞与人免疫细胞共同培养技术验证C-MET对免疫因子分泌的影响,Rt-qPCR检测结果提示:与C-MET高表达组共培养的PBMC中干扰素(INF-γ)的m RNA转录水平是低表达组的77倍、CXCL-10的mRNA转录水平是低表达组的1.6倍,INF-β的mRNA转录水平是低表达组的2倍。结论C-MET表达可能通过IL-17信号通路、白细胞分化、细胞因子受体活性通路参与肿瘤周围免疫微环境调控。

Experimental verification of nanonization enhanced solubility for poorly soluble optoelectronic molecules

Solubility enhancement has been a priority to overcome poor solubility with optoelectronic molecules for solution-processable devices. This study aims to obtain experimental data on the effect of particle sizes on the solubility properties of several typical optoelectronic molecules in organic solvents, including the solubility results of 1,3-bis(9-carbazolyl)benzene(m CP), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)ben zene(TPBi) and 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole(PBD) in ethanol and acetonitrile,respectively. Nanoparticles of m CP, TPBi and PBD with sizes from dozens to several hundred nanometers were prepared by solvent antisolvent precipitation method and their solubility were determined by using isothermal saturation method. The saturation solubility of nanoparticles of three kinds of optoelectronic molecules exhibited increase of 12.9%-25.7% in comparison to the same raw materials in the form of microparticles. The experimental evidence indicates that nanonization technology is a feasible way to make optoelectronic molecules dissolve in liquids with enhanced solubility.

Quantification of soluble epoxide hydrolase inhibitors in experimental and clinical samples using the nanobody-based ELISA

To ensure proper dosage of a drug,analytical quantification of it in biofluid is necessary.Liquid chromatography mass spectrometry(LC-MS)is the conventional method of choice as it permits accurate identification and quantification.However,it requires expensive instrumentation and is not appropriate for bedside use.Using soluble epoxide hydrolase(sEH)inhibitors(EC5026 and TPPU)as examples,we report development of a nanobody-based enzyme-linked immunosorbent assay(ELISA)for such small molecules and its use to accurately quantify the drug chemicals in human samples.Under optimized conditions,two nanobody-based ELISAs were successfully established for EC5026 and TPPU with low limits of detection of 0.085 ng/mL and 0.31 ng/mL,respectively,and two order of magnitude linear ranges with high precision and accuracy.The assay was designed to detect parent and two biologically active metabolites in the investigation of a new drug candidate EC5026.In addition,the ELISAs displayed excellent correlation with LC-MS analysis and evaluation of inhibitory potency.The results indicate that nanobody-based ELISA methods can efficiently analyze drug like compounds.These methods could be easily implemented by the bedside,in the field in remote areas or in veterinary practice.This work illustrates that nanobody based assays offer alternative and supplementary analytical tools to mass spectrometry for monitoring small molecule medicines during clinical development and therapy.Attributes of nanobody based pharmaceutical assays are discussed.

宫颈癌患者癌组织c-Met mRNA与NF-κB mRNA表达的关系及其对预后的影响

目的分析肝细胞生长因子受体原癌基因c-Met mRNA与核因子-κB(NF-κB)mRNA在宫颈癌发病中的关系及对宫颈癌患者预后的影响。方法选取本院宫颈癌患者89例作为癌变组,宫颈癌前病变患者89例作为癌前病变组,因子宫肌瘤行全子宫切除患者89例作为正常宫颈组。采用RT-PCR检测3组宫颈组织中c-Met、NF-κB mRNA相对表达量。采用Spearman/Pearson分析c-Met mRNA与NF-κB mRNA在宫颈癌发病中的关系。采用Kaplan-Meier曲线分析不同c-Met mRNA、NF-κB mRNA表达水平患者的3年生存率。结果宫颈组织中c-Met、NF-κB mRNA相对表达量,癌变组>癌前病变组>正常宫颈组(P<0.05)。癌前病变组、癌变组c-Met mRNA与NF-κB mRNA呈正相关(P<0.001)。c-Met高表达与NF-κB mRNA高表达在宫颈癌发病中呈正向交互作用(P<0.05)。c-Met、NF-κB mRNA与宫颈癌临床分期、淋巴结转移、脉管浸润呈正相关,与分化程度呈负相关(P<0.05)。癌变组c-Met、NF-κB mRNA高表达患者3年生存率低于低表达患者(P<0.05)。结论c-Met mRNA与NF-κB mRNA高表达在宫颈癌发病中呈正向交互作用,与临床分期、淋巴结转移、脉管浸润呈正相关,且宫颈癌患者3年生存率显著降低。

CTC、RON及c-Met在早期三阴性乳腺癌预后预测中的作用

目的 分析循环肿瘤细胞(CTC)、受体酪氨酸激酶(RON)及间质表皮转化因子(c-Met在早期三阴性乳腺癌(TNBC)预后预测中的作用。方法 分析2018年1月至2021年1月于郑州大学第一附属医院进行诊治的1 225例乳腺癌患者资料,根据纳入标准最终选取168例TNBC患者设为研究组,选取患者癌旁3 cm的组织为对照组,另选取同时期在本院进行健康体检者168名为健康组。根据患者治疗后的预后情况将研究组分为预后良好组(n=142)以及预后不良组(n=26)。比较研究组与健康组CTC的表达情况,比较研究组与对照组c-Met与RON的表达情况,采用多元Logistic回归分析影响TNBC预后的独立危险因素;并通过受试者工作特征曲线(ROC)分析c-Met、RON、CTC对TNBC患者预后的预测价值。结果 研究组CTC水平高于健康组,差异有统计学意义(P<0.05);研究组c-Met与RON阳性表达高于对照组,差异有统计学意义(P<0.05);预后良好组、预后不良组年龄、肿瘤直径比较差异无统计学意义(P>0.05),预后良好组、预后不良组腋窝淋巴结、体重指数、糖尿病、RON、c-Met、CTC比较,差异有统计学意义(P<0.05),经非条件多因素logistic回归模型分析显示,腋窝淋巴结转移、CTC阳性、RON阳性、c-Met阳性为TNBC患者预后的危险因素(P<0.05)。CTC、RON及c-Met单独检测以及三者联合检测AUC分别为0.764、0.778、0.776、0.857,其中三者联合检测AUC值最大。结论 联合检测RON、c-MET、CTC水平对TNBC患者预后具有一定的预测价值。

Eukaryotic expression, purification and activity characterization of human soluble DSG2 extracellular domain protein

Objective:To construct a secretory eukaryotic expression vector of DSG2 fused with the Fc region of the human IgG,to validate its expression in 293T cells,and to purify the secretory protein with biological activity.Methods:The DSG2 extracellular domain fragment gene(DSG2ex),was amplified by PCR,and was inserted into the eukaryotic expression plasmid pCMV3-IgG1 to construct the recombinant eukaryotic expression plasmid-pCMV3-DSG2ex-IgG1.The successfully constructed eukaryotic expression plasmid was transfected into 293T cells to express and secrete DSG2 extracellular domain protein.The targeted protein was purified from the cell culture supernatant by Protein A affinity chromatography and confirmed by Western Blotting and ELISA.Results:The pCMV3-DSG2ex-IgG1 eukaryotic expression plasmid was successfully constructed.The highest protein expression level was obtained with 293T cells after 96 h of transfection.The relative molecular mass of the purified product was between 100 and 130 kDa was estimated by SDS-PAGE,which was consistent with the expectation.The yield of the purified protein reached 0.8 mg/ml with a purity over 90%.The purified DSG2 extracellular domain protein with IgG1 tag was recognized by IgG monoclonal antibodies by Western blotting.Moreover,the ELISA results showed that the prepared DSG2 extracellular domain protein had significant binding activity to human type 55 adenovirus Fiber Knob protein(HAdV-55).Conclusion:A simple and efficient method for eukaryotic expression and purification of human soluble DSG2 extracellular domain protein was successfully established,and biologically active DSG2 extracellular domain protein was purified,which laid the foundation for the later study of its protein function and anti-adenovirus drugs.

Elevated soluble fas blood concentrations in patients dying from spontaneous intracerebral hemorrhage

BACKGROUND Several studies of spontaneous intracerebral hemorrhage(SICH)patients have shown apoptotic changes in brain samples after hematoma evacuation.However,there have been no data on the association between blood concentrations of soluble fas(sFas)(the main surface death receptor of the extrinsic apoptosis pathway)and the prognosis of spontaneous intracranial hypotension(SIH)patients.AIM To determine whether there is an association between blood sFas concentrations and SICH patient mortality.METHODS We included patients with severe and supratentorial SIH.Severe was defined as having Glasgow Coma Scale<9.We determined serum sFas concentrations at the time of severe SICH diagnosis.RESULTS We found that non-surviving patients(n=36)compared to surviving patients(n=39)had higher ICH score(P=0.001),higher midline shift(P=0.004),higher serum sFas concentrations(P<0.001),and lower rate of early hematoma evacuation(P=0.04).Multiple logistic regression analysis showed an association between serum sFas concentrations and 30-d mortality(odds ratio=1.070;95%confidence interval=1.014-1.129;P=0.01)controlling for ICH score,midline shift,and early hematoma evacuation.CONCLUSION The association of blood sFas concentrations and SICH patient mortality is a novel finding in our study.

Research progress on the development of hepatocyte growth factor/c-Met signaling pathway in gastric cancer:A review

Hepatocyte growth factor(HGF)and its receptor,c-Met,play important roles in the occurrence,development,and treatment of gastric cancer(GC).This review explored the function of the HGF/c-Met signaling pathway in GC and its potential targeted therapeutic mechanisms.As one of the most common malignant tumors worldwide,GC has a complex pathogenesis and limited therapeutic options.Therefore,a thorough understanding of the molecular mechanism of GC is very important for the development of new therapeutic methods.The HGF/c-Met signaling pathway plays an important role in the proliferation,migration,and invasion of GC cells and has become a new therapeutic target.This review summarizes the current research progress on the role of HGF/c-Met in GC and discusses targeted therapeutic strategies targeting this signaling pathway,providing new ideas and directions for the treatment of GC.

分泌型PD-1抗体可提高c-Met CAR-T细胞对胰腺癌细胞的杀伤作用

目的设计并制备能够分泌PD-1抗体和靶向c-Met的CAR-T细胞,以消除肿瘤对CAR-T细胞的免疫抑制作用,从而提高CAR-T细胞对胰腺癌的治疗效果。方法采用Kaplan-Meier Plotter、GEPIA和Timer2.0生物信息学数据库,分析c-Met在胰腺癌中的表达、生存期及免疫浸润。免疫组化检测胰腺癌临床样本c-Met和PD-L1表达,流式细胞术验证胰腺癌细胞Aspc-1 c-Met和PD-L1表达通过基因编辑将PD-1分泌型抗体和HIS标签连接至2代c-Met CAR分子后,构建PD-1/c-Met CAR质粒并包被慢病毒,慢病毒感染至活化T细胞内,通过流式细胞技术检测CAR-T阳性率和细胞亚群;Western blotting检测分泌型PD-1抗体在细胞上清液中的存在;体外功能试验中,通过LDH释放实验检测CAR-T对靶细胞的杀伤效率,CCK-8检测靶细胞存在下PD-1抗体对CAR-T增殖的促进作用。ELISA检测PD-1/c-Met CAR-T和c-Met CAR-T活化后细胞因子的分泌量。结果生信分析结果显示,胰腺癌组织c-Met表达高于正常组织(P<0.01);c-Met表达水平与胰腺癌患者生存期呈负相关(P<0.01)。c-Met的表达可能与多种免疫细胞浸润成正相关。免疫组化结果显示,胰腺癌c-Met和PD-L1表达均高于癌旁组织(P<0.01);流式细胞术结果显示,Aspc-1细胞c-Met和PD-L1表达量为90.7%和57.7%,琼脂糖凝胶电泳显示成功制备四代PD-1/c-Met CAR分子;流式细胞术和Western blotting显示,成功构建PD-1/c-Met CAR-T且PD-1抗体可顺利分泌。体外功能验证中LDH结果显示,PD-1/c-Met CART对肿瘤细胞杀伤效率在效靶比为20:1时高于c-Met CAR-T(P<0.01);CCK-8实验结果显示,靶细胞刺激72 h后增殖效率高于c-Met CAR-T(P<0.01);ELISA结果显示,PD-1/c-Met CAR-T分泌的细胞因子IL-2和TNF-α高于c-Met CAR-T(P<0.01)。结论PD-1抗体分泌型c-Met CAR-T可成功构建,并在体外胰腺癌细胞上显示出优于c-Met CAR-T肿瘤杀伤效率和增殖效率。

细胞间质上皮转化因子(c-Met)中和抗体的筛选及鉴定

目的通过抗体的随机突变库和细胞展示技术,对具有中和活性的细胞间质上皮转化因子(c-Met)抗体进行结构和活性优化,获得亲和力高、激动活性低的抗体,并使其保持亲本抗体的中和及内化活性,提高抗体偶联药物(ADC)的成药性。方法构建和筛选c-Met中和激动型抗体3E1D7的重链互补决定区3(CDR3)随机突变库,获得CDR3区有4个氨基酸突变的候选抗体2G5。通过ELISA检测2G5的中和活性,流式细胞术检测其在A549细胞的内化,CCK-8法检测2G5对人脐静脉内皮细胞(HUVEC)增殖的影响,通过Transwell^(TM)小室检测2G5对A549细胞迁移的影响,通过Western blot法检测2G5对c-Met磷酸化的影响。结果突变抗体2G5与抗原c-Met保持较高的结合能力,半数有效浓度(EC_(50))为41.53 ng/mL,并具有较高的中和活性。在A549细胞中,2G5引起显著的内化效应,但不激活c-Met信号通路和细胞迁移。2G5不能引起HUVEC增殖。结论通过建立抗体随机突变库可优化c-Met抗体的活性,获得成药性更高的突变型抗体。

人源抗c-Met单链抗体腹腔注射可抑制A549肺腺癌荷瘤小鼠移植瘤生长

目的 该实验旨在验证间质上皮转化单链抗体(Met scFv)在体内对皮下移植瘤裸鼠的抗肿瘤作用。方法 建立裸鼠肿瘤模型,皮下注射A549肺腺癌细胞,成瘤后通过腹腔注射IRDye680 LT N-羟基琥珀酰亚胺(NHS)酯标记的Met scFv,借助小动物成像仪进行实时监测以观察该抗体在荷瘤小鼠体内的动态分布情况,检测肿瘤组织细胞c-Met与抗体的亲和力,定期尾静脉注射Met scFv,观察肿瘤体积变化并绘制肿瘤生长曲线。免疫组织化学染色法检测Met scFv是否能有效结合肿瘤组织中的c-Met抗原。结果 裸鼠体内分布结果表明,在最初的3 h内,Met scFv主要分布于腹腔内。经过大约48 h,荧光信号开始在肿瘤组织中聚集。瘤体免疫组织化学染色结果显示,肿瘤组织中c-Met高表达;定期尾静脉注射Met scFv,可使小鼠瘤体生长明显减缓。结论 Met scFv在体内特异性识别肿瘤细胞且表现出显著的抗肿瘤活性。

c-Met作为嵌合抗原受体T(CAR-T)细胞治疗结肠癌靶点的生物信息学预测及验证

目的探索细胞间充质上皮转化因子(c-Met)作为嵌合抗原受体T(CAR-T)细胞治疗结肠癌有效靶点的可能性。方法通过生物信息学方法分析c-Met在结肠腺癌(COAD)中的特异性表达及其临床意义;使用免疫组织化学验证结肠癌临床患者肿瘤组织中c-Met的表达,采用流式细胞术检测HCT116结肠癌细胞株中c-Met的表达;使用慢病毒感染人外周血单个核细胞(PBMC)中原代T细胞,制备靶向c-Met的二代CAR-T细胞,并观察c-Met CAR-T细胞对HCT116细胞的抑制效果。结果免疫组织化学与生物信息学显示c-Met在COAD中高表达,其中相对低表达的患者生存预后较好,在正常结肠组织中低表达或不表达。流式细胞术显示c-Met在HCT116细胞中也高表达。c-Met CAR-T细胞能够靶向表达抗原的肿瘤细胞,并且在抗原刺激下,CAR-T细胞特异性增殖,起到杀伤癌细胞与释放白细胞介素2(IL-2)和γ干扰素(IFN-γ)的生物学作用。结论c-Met有成为COAD潜在治疗靶点的潜能;c-Met CAR-T细胞在体外对结肠癌细胞具有抑制作用。

Anti-tumor Effect and Protective Effect on Chemotherapeutic Damage of Water Soluble Extracts from Hedyotis diffusa

Bai-Hua-She-She-Cao Hedyotis diffusa Willd. (Ru-biaceae) is a medicinal herbwidely distributed in northeast Asian countries. In traditional Chinese medicine, it has the effectof 'clearing away heat and toxic material, promoting blood circulation and removing blood stasis'.It is a well known Chinese folk-medicine used for the treatment of appendicitis, sore throat, mumps,acne, sebo-rheic dermatitis and various kinds of tumors, such as tumors of digestive tract,carcinoma of liver. It was reported that the MeOH extract of H. diffusa demonstrated a significantantitumor activity and ursolic acid succeeded in being isolated from the MeOH extract as an activecomponent . Shan BN, et al suggested that the direct aqueous extract of H. diffusa hadimmuno-modulating activity and antitumor activity in vitro through stimulating the immune system tokill or engulf tumor cells. But regarding anti-tumor activity in vivo of water soluble extracts fromH. diffusa, no detail was reported. Therefore, we prepared water soluble extracts (H_1 and H_2)from H. diffusa and evaluated their anti-tumor property in vivo experiments as well as protectiveeffect on chemo-therapeutic damage.

Effects of Cold Acclimation and CaCl_2 on Total Soluble Protein, CaM and Freezing Resistance of Populus tomentosa Seedlings

Populus tomentosa seedlings used for cold acclimation at -3℃ were pretreated with or without 10?mmol·L -1 CaCl 2, 3?mmol·L -1 of Ca 2+ chelator EGTA, 0 1?mmol·L -1 of Ca 2+ channel inhibitor LaCl 3,and 0 05?mmol·L -1 of CaM antagonist CPZ. The changes in the contents of total soluble protein and CaM, and freezing resistance in all pretreated seedlings in various periods ( viz: following cold acclimation, chilling stress and recovery) were investigated. Results showed that cold acclimation increased the contents of total soluble protein and CaM, and freezing resistance of seedlings, which could be strongly reduced by the pretreatments of EGTA CPZ and LaCl 3 Cold acclimation combined with CaCl 2 pretreatment enhanced the effect of cold acclimation on freezing resistance, and obviously increased the contents of total soluble protein and CaM, reduced the declining degree of the contents of total soluble protein and CaM caused by chilling stress as compared with cold acclimation, augmented the increase in the level of total soluble protein and CaM during the recovery periods. Further analysis found that an increase in total soluble protein content during cold acclimation with or without CaCl 2 pretreatment mainly resulted from the increase in content of heat stable protein in total soluble protein. It is suggested that Ca 2+ calmodulin may be involved in the synthesis of total soluble protein, and the induction of freezing resistance of seedlings.

Cold Acclimation-Induced Changes in Total Soluble Protein, RNA, DNA, RNase and Freezing Resistance in Populus tomentosa Cuttings

The changes in the contents of total soluble protein and RNA, the activity of RNase in leaves and branches of Populus tomentosa cuttings at various periods (viz: cold acclimation, deacclimation, chilling stress and the recovery after chilling stress), and the survival rate and the freezing resistance of cuttings during cold acclimation at -3℃ were investigated. Results showed that cold acclimation not only increased the contents of total soluble protein and RNA, the survival rates and the freezing resistance of cuttings, decreased the activity of RNase, but also reduced the declining degree of total soluble protein and RNA contents, and the increasing level of RNase caused by chilling stress as compared with the controls. In addition, cold acclimation augmented the increase in the level of total soluble protein and RNA, and facilitated the decrease of RNase during the recovery periods. Further analysis found that the DNA content of all treatments kept relative stability at various periods. The changes in total soluble protein, RNA and RNase were closely related to the freezing resistance of cuttings. It appears that the increase of RNA content caused by cold acclimation induced decrease of RNase activity may be involved in the accumulation of total soluble protein and the induction of freezing resistance of cuttings.

Photocatalytic Degradation of Water-Soluble Dyes by LaCoO_3

Pervoskite type oxides LaCoO 3 was prepared by citrate method with the granula of 20 nm-30 nm. With a fluorescent Hg lamp or sunlight as irradiator, the degradation experiments of various water soluble dyes were carried out in the suspension system of LaCoO 3 . The results show that the pervoskite type oxide LaCoO 3 has good photocatalytic activity.Studied by X ray photoelectron spectroscopy and photoacoustic spectra, its photocatalytic activity is found to be related with factors such as the d electron structure of ion Co 3+ ,Co—O binding energy and adsorbed oxygen on the surface etc.