鼠抗人hMIC-l单克隆抗体抑制裸鼠移植人胰腺癌体内研究

目的：初步研究鼠抗人hMIC-l单克隆抗体对胰腺癌体内给药的抗肿瘤活性,为hMIC-l抗体应用于肿瘤治疗提供实验依据。方法2种人胰腺癌细胞株PANC-1和SW1990各腋窝皮下接种24只Balb/c裸鼠,共计48只皮下接种荷瘤裸鼠分别随机共分为8组,每组6只荷瘤鼠。模型对照组荷瘤裸鼠腹腔注射0.9％氯化钠注射液（10 mL/kg,NS,Biw,ip ×8）,阳性对照组荷瘤裸鼠腹腔注射键择（50 mg/kg,qw,ip ×4）,鼠抗人hMIC-l单克隆抗体组分别荷瘤鼠尾静脉内注射鼠抗人hMIC-l单克隆抗体（10 mg/kg,Biw,ip ×8）共4周或（2 mg/kg,Biw,ip ×8）共4周。观察荷瘤裸鼠日常表现、肿瘤生长、实验后肿瘤组织切片HE染色后光镜下的组织形态学改变。结果荷瘤裸鼠尾静脉内注射鼠抗人hMIC-l单克隆抗体组裸鼠（10 mg/kg,Biw,iv ×8）肿瘤生长缓慢,瘤体明显小于模型对照组,并呈现量效关系。镜下观察鼠抗人hMIC-l单克隆抗体组实验后肿瘤组织切片胰腺结构破坏,有大量淋巴细胞浸润,肿瘤细胞明显坏死,细胞溶解。结论尾静脉内注射鼠抗人hMIC-l单克隆抗体（10 mg/kg,Biw,iv ×8）能有效抑制裸鼠移植人胰腺癌PANC-1肿瘤生长,使瘤组织坏死、结构破坏。     

转铁蛋白修饰脂质体的制备及其肝癌靶向性研究

目的：肿瘤的靶向治疗是当前研究的热点,肝肿瘤细胞表面有大量的转铁蛋白受体表达,而正常组织较少,因此本研究制备转铁蛋白（TF）修饰的脂质体（TFLPs）,并对其肝肿瘤靶向性进行研究。方法：采用薄膜分散法制备普通脂质体,考察其形态,粒径,电位。通过体外血清稳定性模拟脂质体进入体内后的稳定性。通过HepG2肿瘤细胞对TFLPs的摄取实验考查脂质体与肝癌细胞的亲和力。构建荷瘤裸鼠模型,考查TFLPs在荷瘤裸鼠体内的分布。结果：所制备的TFLPs平均粒径为108．8±9．5nm,Zeta电位为．1．80±0．73mV。学期稳定性试验结果显示,TFLPs在24h内具有良好的血清稳定性。体外细胞摄取实验表明,HepG2细胞对TFLPs的摄取效率是普通长循环脂质体（LPs）的3．4倍。荷瘤裸鼠肝组织和肿瘤组织切片结果显示,TFLPs比LPs具有更好的肿瘤靶向性。结论：该脂质体制备方法简单,与LPs相比,经转铁蛋白修饰可显著提高肿瘤细胞对脂质体的摄取,TFLPs是一种潜在高效的肝癌靶向给药系统。     

全反式维甲酸对U87-MG细胞裸鼠皮下移植瘤模型中血管生成拟态的影响

目的:明确全反式维甲酸对人恶性脑胶质瘤U87-MG细胞体内血管拟态形成的影响。方法:体外培养U87-MG细胞,并建立裸鼠皮下移植瘤模型,利用全反式维甲酸进行干预,检测荷瘤裸鼠肿瘤生长情况;利用HE染色对肿瘤组织进行细胞形态学观察;利用CD34-PAS双染法观察肿瘤血管拟态的形成情况。结果:U87-MG细胞在裸鼠体内成功荷瘤并出现血管拟态;全反式维甲酸显著抑制了U87-MG细胞实体瘤的生长和血管拟态的形成。结论:全反式维甲酸具有显著的抗肿瘤能力,其作用机制与血管拟态形成相关。     

裸鼠肿瘤动物模型VEGF受体表达及其意义

目的　通过免疫组织化学染色了解flt 1与flk 1 KDR(VEGF的两个高亲和受体 )在人肿瘤细胞皮下接种肿瘤动物模型的血管内皮细胞与肿瘤细胞中的表达。方法　取荷瘤裸鼠皮下接种瘤块 ,漂洗、固定、石蜡连续切片 ,进行两种受体相应免疫组化检测。结果　在 13种荷瘤裸鼠血管内皮细胞及肿瘤细胞中flt 1的阳性率大部分为强阳性或中阳性 ,而只有在荷人胃腺癌MKN 4 5裸鼠的肿瘤细胞中flt 1的阳性率为弱阳性 ,在荷人卵巢癌SKOv3裸鼠的肿瘤细胞中flt 1的表达为阴性。相比较而言 ,在 13种荷瘤裸鼠血管内皮细胞及肿瘤细胞中KDR的阳性率大部分为中阳性或弱阳性 ,并且在荷人肝癌SMMC 772 1裸鼠 ,荷人胃腺癌SPC A1裸鼠 ,荷人高转移肝癌移植瘤裸鼠 ,荷人卵巢癌SKOv3裸鼠的肿瘤细胞中 ,荷人宫颈癌移植瘤裸鼠和荷人胃腺癌MKN 4 5裸鼠的肿瘤细胞中 ,KDR表达为阴性。结论　VEGF受体共同表达于肿瘤血管内皮细胞与肿瘤细胞 ,提示了VEGF与VEGF受体结合作用在肿瘤演化中的重要性 ,为靶向于VEGF受体的基因治疗策略选择裸鼠动物模型提供了参考依据     

替吉奥联合三维适形放疗对胰腺癌细胞生物学的影响

目的：探究替吉奥复方制剂联合三维适形放射疗法对胰腺癌细胞生物学的影响及安全性评价。方法：培养PANC-1人胰腺癌细胞,构建PANC。1胰腺癌裸鼠异位肿瘤模型并随机进行分组。观察替吉奥联合三维适形放疗对胰腺癌肿瘤细胞生长的抑制作用,记录荷瘤裸鼠的肿瘤体积以及生存期。同时观察联合治疗所产生的副作用。结果：相比于单独用药组和单独放疗组,联合组能够显著抑制肿瘤体积生长,延长荷瘤裸鼠的中位生存期。结论：替吉奥单独给药和单独三维适形放疗均能抑制肿瘤的生长,二者联合使用能够发挥协同作用,是一种潜在的高效的胰腺癌治疗手段。     

不同方法建立的人大细胞肺癌裸鼠移植瘤模型的生物学特点

目的比较三种常用的皮下移植瘤造模方法建立的人大细胞肺癌NCI-H460裸鼠移植瘤模型的不同生物学特点,为不同的研究寻找合适的造模方法提供实验依据。方法分别用NCI-H460细胞,NCI-H460移植瘤组织块和移植瘤匀浆液对于BALB/c-nu/nu裸鼠建立皮下移植瘤模型,运用一般生物学指标观察三种移植瘤的成瘤率、瘤重、倍增时间和组织形态;采用全自动生化分析仪检测其外周血中丙氨酸氨基转氨酶（ALT）、天冬氨酸氨基转移酶（AST）、血糖（G1u）、尿素氮（BUN）和肌酐（CREA）等生化指标;利用血球分析仪检测白细胞总数（WBC）并进行分类,最后体外对其腹腔巨噬细胞吞噬活性和NK细胞活性进行了考察。结果本实验中细胞法和匀浆法的成瘤率及肿瘤生长速率显著高于埋块法且其生长更为均一,差异较小。接种5周后,与正常裸鼠比较,三组荷瘤小鼠血液中ALT、AST显著升高,BUN、CREA显著降低,埋块组的AST和BUN两项指标显著高于其他两荷瘤组。此外,接种2周后,荷瘤裸鼠的GLU显著低于正常裸鼠,匀浆液组的GLU降得最低。白细胞中,三种方法组荷瘤小鼠血液中LYM%、MN%、HGB均有降低,匀浆液组和细胞培养组的荷瘤小鼠血液中WBC、NEUT%、PLT显著高于埋块组。免疫细胞活性方面,两种细胞均呈现出正常细胞组〉匀浆组〉细胞组〉埋块组的趋势。结论细胞培养法接种数量可控,肿瘤生长均匀,适合建立不同实验需求的移植瘤模型,组织块移植法适于建立中药抗肿瘤筛选的动物模型,而匀浆液移植法则不推荐使用。裸鼠的生理生化状态和免疫功能与肿瘤的生长有密切的关系。     

特异性人端粒酶催化亚单位基因小干扰RNA对HeLa细胞生长的抑制作用

通过设计并化学合成人端粒酶催化亚单位(hTERT)特异性siRNA,观察其对hTERT表达水平及肿瘤细胞生长的影响。将hTERT-siRNA以脂质体法转染入HeLa细胞,应用RT-PCR、实时定量TRAP、Western印迹、软琼脂克隆形成实验、荷瘤裸鼠肿瘤内注射等方法检测细胞内hTERTmRNA、蛋白质表达水平及对肿瘤细胞生长的影响。RT-PCR、实时定量TRAP和Western印迹的结果显示hTERT-siRNA明显降低了HeLa细胞内hTERT的mRNA及蛋白质表达水平并伴随有端粒酶活性的下降。克隆形成实验表明hTERT-siRNA组的体外肿瘤形成能力受到抑制。荷瘤裸鼠肿瘤内注射hTERT-siRNA使肿瘤平均体积显著小于对照组。TUNEL凋亡检测表明hTERT-siRNA转染组的凋亡率明显高于对照组。研究表明hTERT特异性siRNA可以明显抑制HeLa细胞内hTERT的表达水平,对其生长有明显抑制作用,是一种有前途的肿瘤治疗新方法。     

慢性心理应激通过β-AR-PKA通路促进脑胶质瘤增殖的机制

本研究旨在探讨慢性心理应激是否可以通过β-AR-PKA(β-adrenergic receptor,β-AR)信号通路调节乳酸生成进而促进胶质瘤的增殖。首先构建人胶质瘤荷瘤裸鼠模型,待成瘤后通过束缚方法给予应激刺激4周,观察裸鼠皮下肿瘤增殖情况;ELISA检测血清中肾上腺素(epinephrine,EPI)、去甲肾上腺素(norepinephrine,NE)及瘤组织乳酸的含量;RT-PCR及Western-blotting法检测瘤组织LDHA的表达情况;用NE处理胶质瘤LN229细胞模拟应激刺激,同时加入β-AR-PKA信号通路抑制剂Propranolol及H89,检测细胞中乳酸含量、LDHA表达及细胞增殖的情况。结果显示给予应激刺激后,荷瘤应激组裸鼠皮下肿瘤体积增长明显快于单纯荷瘤组;荷瘤应激组裸鼠EPI、NE、乳酸及瘤体中LDHA的表达均高于荷瘤组;Propranolol及H89均能有效抑制NE诱导的LN229细胞增殖、LDHA的表达及乳酸生成。本研究提示慢性心理应激可以通过β-AR-PKA信号通路调节LDHA的表达,而高浓度的乳酸进一步促进了肿瘤的增殖。     

人脐带间充质干细胞体内移植的安全性研究

目的:探讨人脐带间充质干细胞(hUCMSC)的成瘤性及其对荷瘤鼠肿瘤生长的影响。方法:分离培养hUCMSC,取第6代细胞裸鼠皮下移植,观察其成瘤性;对荷瘤鼠尾静脉注射移植hUCMSC,观察其对肿瘤生长的影响;体外共培养hUCMSC和MCF-7肿瘤细胞,观察hUCMSC对MCF-7细胞克隆形成率的影响。结果:hUCMSC裸鼠皮下移植30 d,未观察到有肿瘤形成;尾静脉注射移植hUCMSC对荷瘤鼠肿瘤的生长无明显影响;体外共培养结果表明,hUCMSC对MCF-7肿瘤细胞的克隆形成无明显影响。结论:hUCMSC体内移植无成瘤性;静脉移植后对肿瘤生长无显著影响。     

重组腺病毒Ad-Mig基因治疗裸鼠肾细胞癌的实验研究

目的:研究腺病毒介导的小鼠Mig基因对BALB/c裸鼠肾细胞癌的抗肿瘤效果,探讨肾细胞癌治疗的新途径.方法:利用786-O肾癌细胞皮下注射BALB/c裸鼠建立肾细胞癌模型,应用携带Mig基因的重组腺病毒(Ad-Mig)直接进行瘤内注射治疗,观察裸鼠皮下肿瘤生长情况和荷瘤裸鼠的生存期;用乳酸脱氢酶(LDH)释放法检测CTL和NK的杀伤活性.结果:Mig基因能显著抑制荷瘤裸鼠皮下肿瘤的生长,并使鼠生存期明显延长,还能显著增强鼠脾细胞NK和CTL杀伤活性.结论:重组腺病毒Ad-Mig基因对鼠肾细胞癌有显著治疗效果.     

猕猴B病毒gC蛋白特异性抗原表位的合成和表达

目的获得B病毒gC蛋白的特异性表位抗原。方法利用长片段基因合成的方法,合成B病毒C蛋白的特性抗原表位基因,将该基因连接到pMAL-5x载体,转化到BL21受体菌进行表达,并纯化表达产物。结果成功的获得了B病毒gC蛋白的特异性抗原蛋白,该蛋白以可溶的形式表达。结论利用原核表达系统,可以产生B病毒gC蛋白的可溶性抗原,可以作为B病毒的检测抗原。     

The emergence and evolution of antimicrobial resistance: Impact on a global scale

The evolution of antimicrobial resistance is a multifaceted issue that is influenced by numerous factors. This growing healthcare problem has significantly impacted the public welfare and has substantially burdened the economic system on a global scale. In an effort to combat this rising problem, several strategies have been implemented in the recent years to stall the progression and decrease the emergence of antimicrobial resistance. The aim of this review article is to describe the various factors that have contributed to the current state of antimicrobial resistance and to evaluate potential strategies developed to reduce the burden of antimicrobial resistance.     

Skeletal metastases: decreasing tumor burden by targeting the bone microenvironment

Several common cancers often metastasize to the skeleton in advanced disease. Bone metastases are incurable and cause protracted, severe symptoms. Growth of tumor in bone is driven by a vicious cycle: tumor-secreted factors stimulate bone cells, which in turn release growth factors and cytokines. The bone-derived factors fuel the vicious cycle by acting back on the tumor cells. The vicious cycle offers novel targets for the treatment of advanced cancers. Treatments can inhibit bone cells (osteoclasts and osteoblasts) that are stimulated by tumor-secreted factors. Drugs can also inhibit tumor responses to factors enriched in the bone microenvironment, such as transforming growth factor-beta. Animal models show that these approaches, especially combination treatments, can reduce tumor burden. The results suggest a novel paradigm in which tumor growth can be effectively inhibited by drugs that target cells in the bone microenvironment and not the tumor cells themselves.     

Phosphate toxicity and tumorigenesis

In this article, we briefly summarized evidence that cellular phosphate burden from phosphate toxicity is a pathophysiological determinant of cancer cell growth. Tumor cells express more phosphate cotransporters and store more inorganic phosphate than normal cells, and dysregulated phosphate homeostasis is associated with the genesis of various human tumors. High dietary phosphate consumption causes the growth of lung and skin tumors in experimental animal models. Additional studies show that excessive phosphate burden induces growth-promoting cell signaling, stimulates neovascularization, and is associated with chromosome instability and metastasis. Studies have also shown phosphate is a mitogenic factor that affects various tumor cell growth. Among epidemiological evidence linking phosphate and tumor formation, the Health Professionals Follow-Up Study found that high dietary phosphate levels were independently associated with lethal and high-grade prostate cancer. Further research is needed to determine how excessive dietary phosphate consumption influences initiation and promotion of tumorigenesis, and to elucidate prognostic benefits of reducing phosphate burden to decrease tumor cell growth and delay metastatic progression. The results of such studies could provide the basis for therapeutic modulation of phosphate metabolism for improved patient outcome.     

Low-intensity combination chemotherapy maximizes host survival time for tumors containing drug-resistant cells

Recent clinical trials have shown that for some cancers, high-intensity alternating chemotherapy does not significantly improve either survival times or response rates compared with nonalternating therapy. The current study uses optimal control to determine the best way to treat a tumor that contains drug-resistant cells that cannot be destroyed. The delivery of two non-cross-resistant chemotherapeutic agents is limited by bounds on the drug concentration and the dose intensity. This ensures that the drug toxicity stays within a tolerable range. The aim of the therapy is to maximize the host survival time, defined as the time over which the tumor burden can be kept below a fixed bound. The model is posed as a free terminal time, optimal parameter selection problem in which the constraints are continuously parametrized by time and the number of courses of therapy is free to vary. New theory is developed so that the optimal parameter selection problem can be solved as a sequence of fixed terminal time problems using existing optimal control software. Numerical simulations of Gompertz tumor growth showed that a treatment maintaining a high tumor burden doubled and sometimes tripled with survival time under aggressive therapy. When these simulations were repeated using exponential and logistic tumor growth models, the tumor burden during treatment had little influence upon survival time. In all simulations, survival time was not extended by delivering the anticancer drugs concurrently instead of staggering the treatment arms.     

盲蝽科昆虫的分类系统概述

依据目前已有的资料 ,概述了盲蝽科昆虫的分类系统。盲蝽科隶属于半翅目异翅亚目臭虫型的盲蝽总科 ,这在半翅目学者中意见一致。但关于盲蝽科亚科及族级水平的分类系统观点不一。最合理的为 6亚科及 8亚科的分类系统。8亚科分类系统是目前最被接受和应用的系统。     

Endpoints,patient selection,and biomarkers in the design of clinical trials for cancer vaccines

Therapeutic cancer vaccines are an emerging and potentially effective treatment modality. Cancer vaccines are usually very well tolerated, with minimal toxicity compared with chemotherapy. Unlike conventional cytotoxic therapies, immunotherapy does not result in immediate tumor shrinkage but may alter growth rate and thus prolong survival. Multiple randomized controlled trials of various immunotherapeutic agents have shown a delayed separation in Kaplan–Meier survival curves, with no evidence of clinical benefit within the first 6–12 months of vaccine treatment. Overall survival benefit is seen in patients with lower disease burden who are not expected to die within those initial 6–12 months. The concept of improved overall survival without marked initial tumor reduction represents a significant shift from the current paradigms established by standard cytotoxic therapies. Future clinical studies of therapeutic vaccines should enroll patients with either lower tumor burden, more indolent disease or both, and must seek to identify early markers of clinical benefit that may correlate with survival. Until then, improved overall survival is the only clear, discriminatory endpoint for therapeutic vaccines as monotherapies.     

Sensitivity coefficient-based uncertainty analysis for multi-functionality in LCA

Purpose

In LCA, a multi-functionality problem exists whenever the environmental impacts of a multi-functional process have to be allocated between its multiple functions. Methods for fixing this multi-functionality problem are controversially discussed because the methods include ambiguous choices. To study the influence of these choices, the ISO standard requires a sensitivity analysis. This work presents an analytical method for analyzing sensitivities and uncertainties of LCA results with respect to the choices made when a multi-functionality problem is fixed.

Methods

The existing matrix algebra for LCA is expanded by explicit equations for methods that fix multi-functionality problems: allocation and avoided burden. For allocation, choices exist between alternative allocation factors. The expanded equations allow calculating LCA results as a function of allocation factors. For avoided burden, choices exist in selecting an avoided burden process from multiple candidates. This choice is represented by so-called aggregation factors. For avoided burden, the expanded equations calculate LCA results as a function of aggregation factors. The expanded equations are used to derive sensitivity coefficients for LCA results with respect to allocation factors and aggregation factors. Based on the sensitivity coefficients, uncertainties due to fixing a multi-functionality problem by allocation or avoided burden are analytically propagated. The method is illustrated using a virtual numerical example.

Results and discussion

The presented approach rigorously quantifies sensitivities of LCA results with respect to the choices made when multi-functionality problems are fixed with allocation and avoided burden. The uncertainties due to fixing multi-functionality problems are analytically propagated to uncertainties in LCA results using a first-order approximation. For uncertainties in allocation factors, the first-order approximation is exact if no loops of the allocated functional flows exist. The contribution of uncertainties due to fixing multi-functionality problems can be directly compared to the uncertainty contributions induced by uncertain process data or characterization factors. The presented method allows the computationally efficient study of uncertainties due to fixing multi-functionality problems and could be automated in software tools.

Conclusions

This work provides a systematic method for the sensitivity analysis required by the ISO standard in case choices between alternative allocation procedures exist. The resulting analytical approach includes contributions of uncertainties in process data, characterization factors, and—in extension to existing methods—uncertainties due to fixing multi-functionality problems in a unifying rigorous framework. Based on the uncertainty contributions, LCA practitioners can select fields for data refinement to decrease the overall uncertainty in LCA results.     

肿瘤血管生成抑制因子在实体瘤治疗中的应用

肿瘤的治疗是近年来广大科研及医务工作者共同关注的问题。本文通过对血管生成与肿瘤生长的关系、血管生成因子和血管生成抑制因子功能的阐述,说明了血管生成抑制因子在肿瘤发生过程中的可能作用,从而为实体瘤的抗血管生成疗法提供了理论依据。     

Chemical mutagenesis: a new strategy against the global threat of infectious diseases

The perpetual evolution of drug-resistant microbes, the overwhelming burden of acquired immune suppression due to HIV, the emergence or re-emergence of various pathogens (West Nile virus, pandemic influenza, Creutzfeld-Jacob disease), and increased fears of bioterrorism has drawn a great deal of new attention to infectious diseases. The pathogenesis of infection is characterized by complex interactions of potentially virulent microorganisms with host genetic and acquired factors. Chemical mutagenesis of the mouse genome provides a robust method to unravel this challenging problem. To deepen our understanding of the natural host response to pathogens, our team and others are interrogating the mouse genome to define genes that are crucial to the defense against infectious diseases (pathogen recognition, viral defense, bacterial defense, prion infection). In this review we highlight the current progress of these efforts and propose a toolbox for other groups that are interested in this endeavor.