1-胺基-4-硝基-1,3-丁二烯的非线性光学性质的理论研究

以B3LYP/6 31+G 水平上优化的构型为基础,采用有限场方法(FF),分别在从头算HF和包含电子相关的MP2及B3LYP水平上计算了1 胺基 4 硝基 1,3 丁二烯的非线性光学系数.发现电子相关对分子的非线性光学极化率的影响很大,在MP2水平上计算的一阶超极化率βvec是相同基组下HF计算值的2～3倍.在从头算水平上,采用含时间的藕合微扰法(TDHF),计算了1 胺基 4 硝基 1,3 丁二烯的非线性光学极化率,得到了分子在730～24791nm范围内的色散曲线,考察了分子的色散效应.

微波辐射下2,6-二甲基-3,5-二乙氧羰基-4-二茂铁基-1,4-二氢吡啶的合成和晶体结构

标题化合物C_23H_27FeNO_4是由二茂铁甲醛、乙酰乙酸乙酯、尿素负载于SiO2在微波辐射下干反应而得。用元素分析、IR、1H NMR对化合物进行了表征,并通过了单晶X-射线衍射法确定了晶体结构,其晶体属三斜晶系,空间群P,Mr = 437.32,a = 7.462(2),b = 8.3574(13),c = 16.491(3) , a = 78.36(2),b = 88.76(3),g = 86.11(2),V = 1004.9(3) 3,Z = 2,Dc = 1.445 g/cm3,m(MoKa) = 7.80 cm-1,F(000) = 460.00,最终的偏离因子为R = 0.063,wR = 0.180。该化合物是1个由二茂铁基和1,4-二氢吡啶环组成的双功能团化合物,其中吡啶环为船式结构。

2-苯基-4-对氯苯基-1,5-苯并硫氮杂-α-(丁二酰亚胺基)-β-内酰胺的高效液相色谱法分析

采用Hypersil-ODS2(4.6mm×250mm,5μm)色谱柱,乙腈-水(70∶30)流动相,242nm检测波长,建立了测定2-苯基-4-对氯苯基-1,5-苯并硫氮杂-α-(丁二酰亚胺基)-β-内酰胺的高效液相色谱法。该法线性范为0～0.1mg/mL,回归方程为A=1.63×108c-2.86×105,相关系数r=0.9994,相对标准偏差为0.33%(c=0.06mg/mL,n=5),检出限为0.08μg/mL。平均回收率在97.2%～102.4%之间。该法重现性好,灵敏度高,简单,快速,准确。

4-(5-硝基-6-羟基-7-甲基苯并唑-2-基)苯甲酸甲酯的合成

针对聚对苯撑苯并二唑(PBO)纤维的抗压性能差和成型困难等问题,提出并合成出一种新单体的前体化合物4-(5-硝基-6-羟基-7-甲基苯并唑-2-基)苯甲酸甲酯(MMNB),总收率56.42%、纯度97.5%;可用于制备AB型单体和甲基改性PBO纤维,以改善PBO纤维的加工性能及热交联后提高轴向抗压能力。结果表明:对苯二甲酸单甲酯(MTA)先经酰氯化,然后在二氯甲烷溶剂中、三乙胺作缚酸剂与2-甲基-4-氨基-6硝基间苯二酚盐酸盐(MANR?HCl)缩合一锅法制备中间体4-[N-(2,4-二羟基-3-甲基-5-硝基苯基)氨甲酰基]苯甲酸甲酯(MNHB),收率为73.65%;MNHB在二乙二醇二甲醚溶剂中多聚磷酸作用下环合脱水合成MMNB,收率为76.61%;并经IR、MS和1H NMR确认。

AAV-mediated expression of p65shRNA and bone morphogenetic protein 4 synergistically enhances chondrocyte regeneration

BACKGROUND:Adeno-associated virus(AAV)gene therapy has been proven to be reliable and safe for the treatment of osteoarthritis in recent years.However,given the complexity of osteoarthritis pathogenesis,single gene manipulation for the treatment of osteoarthritis may not produce satisfactory results.Previous studies have shown that nuclear factorκB could promote the inflammatory pathway in osteoarthritic chondrocytes,and bone morphogenetic protein 4(BMP4)could promote cartilage regeneration.OBJECTIVE:To test whether combined application of AAV-p65shRNA and AAV-BMP4 will yield the synergistic effect on chondrocytes regeneration and osteoarthritis treatment.METHODS:Viral particles containing AAV-p65-shRNA and AAV-BMP4 were prepared.Their efficacy in inhibiting inflammation in chondrocytes and promoting chondrogenesis was assessed in vitro and in vivo by transfecting AAV-p65-shRNA or AAV-BMP4 into cells.The experiments were divided into five groups:PBS group;osteoarthritis group;AAV-BMP4 group;AAV-p65shRNA group;and BMP4-p65shRNA 1:1 group.Samples were collected at 4,12,and 24 weeks postoperatively.Tissue staining,including safranin O and Alcian blue,was applied after collecting articular tissue.Then,the optimal ratio between the two types of transfected viral particles was further investigated to improve the chondrogenic potential of mixed cells in vivo.RESULTS AND CONCLUSION:The combined application of AAV-p65shRNA and AAV-BMP4 together showed a synergistic effect on cartilage regeneration and osteoarthritis treatment.Mixed cells transfected with AAV-p65shRNA and AAV-BMP4 at a 1:1 ratio produced the most extracellular matrix synthesis(P<0.05).In vivo results also revealed that the combination of the two viruses had the highest regenerative potential for osteoarthritic cartilage(P<0.05).In the present study,we also discovered that the combined therapy had the maximum effect when the two viruses were administered in equal proportions.Decreasing either p65shRNA or BMP4 transfected cells resulted in less collagen II synthesis.This implies that inhibiting inflammation by p65shRNA and promoting regeneration by BMP4 are equally important for osteoarthritis treatment.These findings provide a new strategy for the treatment of early osteoarthritis by simultaneously inhibiting cartilage inflammation and promoting cartilage repair.

Skin brightening benefit of 4-hexylresorcinol in vivo and in vitro and its underlying mechanism

4-Hexylresorcinol(4-HR),a potent tyrosinase inhibitor,has been used as an even-tone active ingredient for skin care application since 2007.While the skin brightening efficacy of 4-HR in Chinese population has not been thoroughly investigated and its significance in keratinocytes has not been fully raveled.This study aims to evaluate the skin brightening potential of 4-HR in vivo and in vitro and explore its new mechanism of action through transcriptome approach.The skin brightening effect of 0.4%4-HR in a facial serum was assessed in an 8-week,double-blinded,placebo-controlled,and randomized clinical study in 67 Chinese participants.ITA°,melanin index(MI)and visual grading were measured at baseline and 2,4 and 8 weeks after use.A pigmented living skin equivalent(pLSE)model constructed from Asian skin cells was utilized to assess the brightening efficacy of 0.4%4-HR by measuring the model’s brightness(L^(*)value)and melanin content.Then,transcriptomic analysis of 4-HR treated human epidermal keratinocytes was conducted,and the two in vitro models were adopted for hypothesis validation afterwards.In the clinical study,the result shows both 0.4%4-HR serum and placebo chassis can significantly improve all measures as compared to baseline at the 2,4,and 8 weeks.Furthermore,0.4%HR serum demonstrates a better performance in increasing ITA°as early as 2 weeks of application and decreasing MI value than the placebo group at Week 2.In the pLSE model,0.4%4-HR with topical application evidently increases L^(*)value by 15.88%and decreases melanin content by 47.61%compared to UVB group.RNA-sequencing analysis implies that 4-HR can regulate multiple biological processes including skin development,keratinocyte differentiation,oxidant activity and autophagy function.In the blue-light challenged human keratinocytes model,4-HR shows a significant ROS suppression capacity.In the keratinocytes-melanocytes co-culture model,4-HR prompts autophagy activity and decreases melanin content.Most importantly,the melanin inhibitory activity of 4-HR is compromised after co-treating with Chloroquine,an autophagy inhibitor,suggesting autophagy regulation property of 4-HR may partially contribute to its skin brightening efficacy.Taken together,these data demonstrate skin brightening efficacy of 0.4%4-HR in vivo and in vitro,in addition to acting as a tyrosinase inhibitor,4-HR can contribute to skin brightening benefit via enhancing cellular antioxidant capacity and autophagy activation.

Toll样受体4及小胶质细胞在帕金森病中的作用

目的探讨Toll样受体4(TLR4)及小胶质细胞在帕金森病(PD)中的作用。方法将48只雄性C57BL/6J小鼠随机分为正常对照组、甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)组和TLR4抗体+MPTP组(TLR4抗体组)。用腹腔注射MPTP法制作PD小鼠模型。免疫组织化学法检测TLR4及CD11b的阳性细胞表达数,RT-qPCR法检测小鼠纹状体内TLR4 mRNA、TNF-αmRNA、IL-1βmRNA的表达。结果正常对照组、MPTP组及TLR4抗体组TLR4阳性细胞及CD11b阳性小胶质细胞数量差异有统计学意义(F=331. 758,F=131. 856;均P <0. 001)。MPTP组TLR4、CD11b阳性细胞数最高,对照组最低,三组间两两比较差异有统计学意义(均P <0. 001)。正常对照组、MPTP组及TLR4抗体组小鼠中脑TLR4 mRNA、TNF-αmRNA、IL-1βmRNA表达量差异有统计学意义(F=36. 385,F=299. 599,F=40. 191;均P <0. 001)。MPTP组TLR4 mRNA、TNF-αmRNA、IL-1βmRNA表达量最高,对照组最低,三组间两两比较差异有统计学意义(P <0. 05～0. 01)。结论 MPTP诱导的PD模型CD11b阳性细胞和炎症因子的表达明显上调,而这些上调可以通过TLR4特异性抗体部分阻断。TLR4及小胶质细胞与PD的神经炎症过程密切相关。

Protective effect of erythropoietin against 1-methyl-4-phenylpyridinium-induced neurodegenaration in PC12 cells

Objective The neuroprotective effect of erythropoietin （EPO） against 1-methyl-4-phenylpyridinium （MPP^＋）- induced oxidative stress in cultured PC12 cells, as well as the underlying mechanism, were investigated. Methods PC12 ceils impaired by MPP^＋ were used as the cell model of Parkinson＇s disease. Methyl thiazolyl tetrazolium （MTT） was used to assay the viability of the PC12 cells exposed to gradient concentrations of EPO, and the terminal deoxynucleotidyl transferase dUTP nick end labelling （TUNEL） assay was used to analyze the apoptosis ratio of PC 12 cells. The expression of Bcl-2 and Bax in PC 12 cells were examined by Western blot, and the reactive oxygen species （ROS）, the mitochondrial transmembrane potential and the activity of caspase-3 in each group were detected by spectrofluorometer. Results Treatment of PC12 cells with MPP^＋ caused the loss of cell viability, which may be associated with the elevation in apoptotic rate, the formation of ROS and the disruption of mitochondrial transmembrane potential. It was also shown that MPP＋ significantly induced the upregulation of Bax/Bcl-2 ratio and the activation of caspase-3. In contrast, EPO significantly reversed these responses and had the maximum protective effect at 1 U/mL. Conclusion The inhibitive effect of EPO on the MPP^＋ -induced cytotoxicity may be ascribed to its anti-oxidative property and anti-apoptotic activity, and EPO may provide a useful therapeutic strategy for treatment of neurodegenerative diseases such as Parkinson＇s disease.

Preparation of TiO_2/ITO film by liquid phase deposition and its photoelectrocatalytic activity for degradation of 4-aminoantipyrine

A thin layer of TiO2 film was deposited on ITO surface via the liquid phase deposition （LPD） process. The photocurrent and electrochemical impedance spectroscopy （EIS） measurements indicated that the as-prepared LPD TiO2/ITO film had an excellent photoelectrochemical performance, which showed a sensitive and rapid response to the UV irradiation. The photogenerated electron-hole pairs could be effectively separated by applying an external bias to the TiO2 film electrode. The LPD TiO2/ITO film was employed to study the photoelectrocatalytic （PEC） degradation of 4-aminoantipyrine. Compared with other techniques, the PEC technique based on such a LPD film electrode had a synergetic effect for 4-aminoantipyrine degradation. When the applied bias potential was＋0.8 V and the supporting electrolyte concentration of Na2SO4 was 0.1 mol/L, the highest degradation efficiency within 120 min could reach 95%for 0.1 mmol/L 4-aminoantipyrine solution at pH 2.0.

The Effect of Thoracic Operation on Glucose Transporter-4 mRNA Expression by Preoperative Infusion of Glucose

Objective: To investigate the changes in glucose transporter-4(Glut-4) mRNA expression in skeletal muscle before and after the thoracic operation and to observe the changes in Glut-4 mRNA expression by preoperative infusion of glucose. Methods: Twelve cases of elective thoracic operation were randomly divided into two groups, namely ordinary group Ⅰ and glucose infusion group Ⅱ. One gram of intercostal muscle was taken while thorax being opened and closed from patients under general anesthesia. Total RNA of the muscle cells was extracted by TRIzol one-step assay. Reverse transcription-competitive polymerase chain reaction (RT-PCR) was used to determine the Glut-4 mRNA amplification products with β-actin mRNA as an internal control. The Glut-4 mRNA expression was expressed by targeted gene /β-actin ×100%. The plasma glucose and insulin levels were determined at the same time.Results: Glut-4 mRNA expression was significantly reduced(P<0.05) and plasma glucose level increased (P<0.05), while thorax was being closed as compared with those while being opened. However, Glut-4 mRNA expression in glucose infusion group Ⅱ was significantly higher than ordinary group Ⅰ (P<0.01) and plasma glucose level in group Ⅱ was lower than group Ⅰ(P<0.05) when thorax was being closed. Conclusion: The results indicate that the synthesis of Glut-4 is suppressed by the surgical stress of thoracic operation under general anesthesia. We found that preoperative infusion glucose can increase Glut-4 mRNA expression at the same surgical stress and relieve postoperative insulin resistance.

Coordinated peak expression of MMP-26 and TIMP-4 in preinvasive human prostate tumor

The identification of novel biomarkers for early prostate cancer diagnosis is highly important because early detection and treatment are critical for the medical management of patients. Disruption in the continuity of both the basal cell layer and basement membrane is essential for the progression of high-grade prostatic intraepithelial neoplasia （HGPIN） to invasive adenocarcinoma in human prostate. The molecules involved in the conversion to an invasive phenotype are the subject of intense scrutiny. We have previously reported that matrix metalloproteinase-26 （MMP-26） promotes the invasion of human prostate cancer cells via the cleavage of basement membrane proteins and by activating the zymogen form of MMP-9. Furthermore, we have found that tissue inhibitor of metalloproteinases-4 （TIMP-4） is the most potent endogenous inhibitor of MMP-26. Here we demonstrate higher （p〈0.0001） MMP-26 and TIMP-4 expression in HGPIN and cancer, compared to non-neoplastic acini. Their expression levels are highest in HGPIN, but decline in invasive cancer （p〈0.001 for each） in the same tissues. Immunohistochemical staining of serial prostate cancer tissue sections suggests colocalization of MMP-26 and TIMP-4. The present study indicates that MMP-26 and TIMP-4 may play an integral role during the conversion of HGPIN to invasive cancer and may also serve as markers for early prostate cancer diagnosis.

Effect of IL-4 on altered expression of complement activation regulators in rat pancreatic cells during severe acute pancreatitis

AIM： To investigate the effect of IL-4 on the altered expression of complement activation regulators in pancreas and pancreatic necrosis during experimental severe acute pancreatitis （SAP）. METHODS： SAP model of rats was established by retrograde injection of 5% sodium taurocholate （1 mL/kg） into the pancreatic duct. We immunohistochemically assayed the expression of three complement activation regulators： decay accelerating factor （DAF; CD55）, 20 ku homologous restriction factor （HRF20; CD59） and membrane cofactor protein （MCP; CEH6）, in the pancreatic acinar cells of rats at 0, 3, 6, 12, and 24 h after the induction of SAP model. Meanwhile the levels of amylase and lipase were determined, and morphological examination was performed. Then, 61 rats were randomly divided into three groups. Group A （n = 21） received no treatment after the SAP model was established; group B （n = 20） was given IL-4 （8 IJg/animal） intraperitoneally 0.5 h before the SAP model was established; group C （n = 20） was given IL-4 （8 μg/animal） intraperitoneaUy 0.5 h after the SAP model was established. Plasma amylase and lipase, extent of pancreatic necrosis and expression of complement activation regulators were investigated 6 h after the induction of SAP model. RESULTS： Three complement activation regulators were all expressed in pancreatic acinar cells. MCP was not found on the basolateral surface as reported. Contrary to the gradually increasing plasma level of amylase and lipase, expression of complement activation regulators decreased after SAP model was set up. At the same time, the severity of pancreatic necrosis was enhanced. A strong negative correlation was found between the expression of MCP, DAF, CD59 in pancreatic acinar cells and the severity of pancreatic necrosis （r = -0.748, -0.827, -0.723; P〈0.01）. In the second series of experiments, no matter when the treatment of IL-4 was given （before or after the induction of SAP model）, the serum level of amylase or lipase was decreased and the extent of pancreatic necrosis was ameliorated significantly. Compared to SAP control group, the expression of DAF and CD59 in pancreas was reinforced when IL-4 was given before the induction of SAP model （P〈0.01, P〈0.05）, but the expression of MCP was not influenced （P〉0.05）. The expression of DAF was enhanced, when IL-4 was given after the induction of SAP model （P〈0.05）, but the expression of CD59 and MCP did not change （P〉0.05）. CONCLUSION： Complement activation regulators may participate in the pathogenesis of pancreatic inflammation. Downregulation of complement activation regulators expression may be one of the causes of pancreatic necrosis. IL-4 treatment may control SAP aggravation by enhancing expression of DAF and CD59 in pancreas and decreasing pancreatic necrosis. Moreover, DAF and CD59 may play an important role in the regulation of complement activation regulators during SAP.

Study on an Organic Hybrid Made from Chlorinated Polyethylene and 2,2'-methylene-bis- (4-methyl-6-cyclohexylphenol)

The dynamic mechanical properties and miscibility of an organic hybrid made from chlorinated polyethylene (CPE) and 2, 2'-methyIene-bis-( 4-methyl-6-cyclohexylphenol) ( ZKF ) are mainly discussed in this paper. It is found that ZKF acts as an antiplasticizer in CPE matrix and has good miscibility even with large ratio in CPE /ZKF hybrids. The glass transition temperature of various CPE /ZKF hybrids determined by DSC give a good fit to Wood's equation. Bifunctional ZKF is supposed to improve the intermolecular force of CPE, and the improvement is developed when the ZKF content increases. On the other hand, the viscoelastic properties are highly improved with the addition of ZKF. TA and tanδ peak values increase when the ZKF content increase in the CPE /ZKF hybrids, the damping capacity has been improved during the glass transition of CPE /ZKF hybrids. In addition, the glass transition temperature shifts to room temperature from the low temperature with the continuous addition of ZKF to CPE.

Enantioselective Hydrogenation of Ethyl 2-Oxo-4-phenylbutyrate on Cinchona-Platinum Catalysts

Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amount of modifier, initial concentration of reactant, pressure and temperature on conversion and enantiometric excess in a stirred autoclave and the effects of the liquid velocity, gas velocity, modifier concentration and various catalytic beds in a trickle-bed reactor. The maximum optical yields were about 50% and 60% in the two types of reactors, respectively. It was assumed that the total hydrogenation rate included the reaction rates over the unmodified and modified active sites on platinum surface and a kinetic model, which fitted the experimental data well in autoclave, was obtained. A simplified plug-flow model was proposed to describe the bed average efficiency of trickle-bed reactor.

Chiral Phosphine Ligands Derived from Sugars8. Crystal and Molecular Structure of Diphenyl (methyl 4', 6'-O-benzylidene-2'-deoxy-α-D-altropyranoside-2-)phosphine Oxide

The crystal structure of the title compound, C26H27O6P, has been determined by single--crystal X-ray diffraction. The crystal is monoclinic with space groupP21, a=16. 193(l), b=5. 804(1), c=12. 512(2) A, β=93. 187(5)°, V=1174. 13A3, Dc=1. 319 g/cm3, F(000) =492, μ= 13. 52 cm-1, Z= 2, and final R= 0. 042and Rw= 0. 040 for 2349 reflections (I≥3σ(I)). Structure analysis revealed that thepyranose and 4, 6-O-benzylidene ring of the title compound adopts a distorted chair conformation.

Fuzzy Support Vector Regression Model of 4-CBA Concentration for Industrial PTA Oxidation Process

In the past few years, support vector machines (SVMs) have been applied to many fields, such as pattern recognition and data mining, etc. However there still exist some problems to be solved. One of them is that the SVM is very sensitive to outliers or noises because of over-fitting problem. In this paper, a fuzzy support vector regression (FSVR) method is presented to deal with this problem. Strategies based on k nearest neighbor (kNN) and support vector data description (SVDD) are adopted to set the fuzzy membership values of data points in FSVR.The proposed FSVR soft sensor models based on kNN and SVDD are employed to predict the concentration of 4-carboxy-benzaldehyde (4-CBA) in purified terephthalic acid (PTA) oxidation process. Simulation results indicate that the proposed method indeed reduces the effect of outliers and yields higher accuracy.

Cytotoxic T-lymphocyte antigen 4 gene polymorphisms and susceptibility to chronic hepatitis B

AIM： To assess the three polymorphJsm regions within cytotoxic T-lymphocyte antigen 4 （CTLA-4） gene, a C/T base exchange in the promoter region-318 （CTLA-4 -318C/T）, an A/G substitution in the exon 1 position 49 （CTLA-4 49A/G）, a T/C substitution in 1172 （CTLA-4 -1172T/C） in patients with chronic hepatitis B. METHODS： Fifty-one patients with chronic hepatitis B virus infection and 150 healthy subjects were recruited sequentially as they presented to the hepatic clinic. Classification of chronic hepatitis B virus （HBV）-infected patients was as asymptomatic carrier state （26 patients） and chronic hepatitis B （25 patients）. Genomic DNA was isolated from anti-coagulated peripheral blood Bully coat using Miller＇s salting-out method. The presence of the CTLA-4 gene polymorphisms was determined using polymerase chain reaction amplification refractory mutation system （ARMS）. RESULTS： We observed a significant association between -318 genotypes frequency （T＋C-, T＋C＋, T-C＋） and susceptibility to chronic hepatitis B （P=0.012, OR=0.49, 95%CI： 0.206-1.162）. However, we did not observe a significant association for ＋49 genotype frequency （T＋C＋, T＋C- T-C＋） and -1172 genotype frequency （C＋T＋, T＋C- C＋T-） and state of disease. CONCLUSION： Our results suggest that CTLA-4 gene polymorphisms may partially be involved in the susceptibility to chronic hepatitis B.

Bio‐inspired nanostructured g-C_(3)N_(4)-based photocatalysts:A comprehensive review

As a new organic conjugated semiconductor,graphitic carbon nitride(g-C_(3)N_(4))is emerging as a fascinating material for various photocatalytic applications due to its adjustable electronic structure,outstanding thermal endurance,appealing chemical stability,low cost,and environmental friendliness.Nevertheless,unmodified bulk g-C_(3)N_(4) possesses some intrinsic limitations related to poor crystallinity,marginal visible-light harvesting,easy recombination of charge pairs,small surface area,and slow charge migration,which give rise to the low quantum efficiency of photocatalytic reactions.One efficient strategy to overcome these shortcomings is the manipulation of the microstructures of g-C_(3)N_(4).Other than the traditional structure control,mimicking the structures of creatures in nature to design and construct bio-inspired structures is a promising approach to improve the photocatalytic performance of g-C_(3)N_(4) and even g-C_(3)N_(4)-based systems.This review summarizes the recent advances of the traditional structure-control of g-C_(3)N_(4)-based systems,and bio-inspired synthesis of g-C_(3)N_(4)-based systems from two aspects of structural bionics and functional bionics.Furthermore,the fundamentals of bio-inspired design and fabrication of g-C_(3)N_(4)-based systems are introduced in detail.Additionally,the different theoretical calculations,diverse photocatalytic applications and various modification strategies of bio-inspired structured g-C_(3)N_(4)-based systems are recapped.We believe that this work will be a guiding star for future research in the new field of biomimetic photocatalysis.

Effect of deleted pancreatic cancer locus 4 gene transfection on biological behaviors of human colorectal carcinoma cells

AIM: To investigate the effect of deleted pancreatic cancer locus 4 (DPC4) gene transfection on biological behaviors of human colorectal carcinoma cells and the role of DPC4 gene in colorectal carcinogenesis. METHODS: PcDNA3.1-DPC4 plasmid was re-constructed by gene-recombination technology. SW620 cells, a human colorectal carcinoma cell line, were transfected with PcDNA3.1-DPC4 plasmid using lipofectamine transfecting technique. Transfected cells were selected with G418. Expression of Smad4 protein was detected in cells transfected with DPC4 gene by immunohistochemistry and Western blot. Biological characterristics of transfected cells were evaluated by population-doubling time and cloning efficiency. Alterations of percentage of S phage cells (S%) and apoptosis rate were determined by flow-cytometry. RESULTS: PcDNA3.1-DPC4 plasmid was constructed successfully. SW620 cells transfected with PcDNA3.1-DPC4 plasmid (DPC4+-SW620 cells) showed a strong intracellular expression of Smad4 protein, and the positive signal was localized in cytoplasm and nuclei, mainly in cytoplasm, where the expressions of Smad4 protein in SW620 cells transfected with PcDNA3.1 plasmid (PcDNA3.1-SW620 cells) and non-transfected SW620 cells (SW620 cells) were weaker than those in DPC4+-SW620 cells. The population-doubling time in DPC4+-SW620 cells (116 h) was significantly longer than that in SW620 cells (31 h) and PcDNA3.1-Sw620 cells (29 h) (P<0.01). The cloning efficiencies of DPC4+-SW620 cells (12%) were markedly lower than those of SW620 cells (69%) and PcDNA3.1-Sw620 cells (67%) (P<0.01). Compared with SW620 cells and PcDNA3.1-Sw620 cells, the Go-G1% of DPC4+-SW620 cells was obviously higher and the S% was markedly lower (P<0.05). Apoptosis rate of DPC4+-SW620 cells was significantly higher than that of SW620 cells and PcDNA3.1-SW620 cells. CONCLUSION: PcDNA3.1-DPC4 plasmid can be successfully re-constructed and stably transfected into human SW620cells, thereby the cells can steadily express Smad4. DPC4 protein may regulate proliferation of colorectal carcinoma cells by inhibiting cell growth and inducing cell apoptosis.

Effect of 2-amino-2-[2-(4-octylphenyl) ethyl] propane- 1,3-diol hydrochloride (FTY 720) on immune liver injury in mice

AIM: To investigate the protective effect against two immune liver injury models in mice by 2-amino-2-[2-(4-octylphenyl) ethyl] propane-l,3-diol hydrochloride and its possible mechanisms in Con A-induced liver damage. METHODS: Liver tissue or hepatocyte injury was monitored biochemically by measuring alanine aminotransferase (sALT) and aspartate aminotransferase (sAST) activity. Hematoxylin & eosin (HE) staining was used for histopathological examination. To evaluate the role of IFN-γ and IL-4 in the liver injury, serum levels of IFN-γ and IL-4 were determined using commercially available ELISA kit at 12 h after Con A challenge. We also determined FTY 720-induced spleen cell apoptosis by flow cytometry analysis or spleen cell proliferation test. RESULTS: Different doses of FTY 720 treatment dramatically reduced circulating markers of hepatocyte injury in two kinds of immunological liver injury models. FTY 720 dramatically reduced the elevated serum IFN-γ and IL-4 levels after Con A injection. Effect of spleen cell supernatants treated with Con A or FTY 720 on hepatocytes showed that ALT activities in cultured hepatocyte supernatants in Con A treatment group increased markedly and FTY 720 could reduce this elevated ALT activities in FTY 720 treatment group. FTY 720 dose-dependently increased the percentage of apoptotic cells in T cells and inhibited splenocyte proliferation induced by Con A. CONCLUSION: Pretreatment with FTY 720 was shown to produce protective effect on the immune liver injury in mice. The possible mechanism of FTY 720 on Con A-induced liver damage is that it could inhibit lymphocyte proliferation and induce lymphocyte apoptosis, resulting in the reduction of IL-4 or IFN-γ release, and subsequently protecting liver from being damaged by Con A.