树瘤状ZnO-Bi_2O_3复合氧化物微晶的生长及光学特性

利用超声液相掺杂法合成具有三级分型结构的Bi_2O_3-ZnO纳米复合氧化物.用粉末X射线衍射(XRD)和X射线光电子能谱(XPS)对产物的物相和组成进行分析.扫描电镜观察结果表明,超声时间和掺杂氧化铋摩尔分数是控制产物形貌的关键因素.同时探讨树瘤状晶体形成机理.紫外-可见(UV-Vis)和荧光光谱(PL)显示所合成的产品具有光学性质.

不锈钢GTAW焊焊接中的氧化试验研究

对于不锈钢的焊接,在NDT检测中仅对夹渣、未熔合、未焊透、气孔等缺陷均有评定标准,而对菜花状缺陷、树瘤状氧化缺陷、蓝脆现象、氧化现象等却没有评定方法及标准。为此,以不锈钢管的焊接试验为主结合不锈钢板的焊接,针对不锈钢在GTAW焊焊接中氧化缺陷的防止方法、氧化评定及检测标准提出几点看法,供行业界借鉴与批评指证。

Heat-shocked tumor cell lysate-pulsed dendritic cells induce effective anti-tumor immune response in vivo

AIM. To study whether heat-shocked tumor cells could enhance the effect of tumor cell lysate-pulsed dendritic cells （DCs） in evoking anti-tumor immune response in vivo. METHODS： Mouse undifferentiated colon cancer cells （CT-26） were heated at 42℃ for 1 h and then frozenthawed. The bone marrow-derived DCs pulsed with heatshocked CT-26 cell lysate （HSCT-26 DCs） were recruited to immunize syngeneic naive BALB/c mice. The cytotoxic activity of tumor specific cytotoxic T lymphocytes （CTLs） in mouse spleen was evaluated by IFN-enzyme-linked immunospot （ELISpot） and LDH release assay. The immunoprophylactic effects induced by HSCT-26 DCs in mouse colon cancer model were compared to those induced by single CT-26 cell lysate-pulsed DCs （CT-26 DCs） on tumor volume, peritoneal metastasis and survival time of the mice. RESULTS： Heat-treated CT-26 cells showed a higher hsp70 protein expression. Heat-shocked CT-26 cell lysate pulsing elevated the co-stimulatory and MHC-Ⅱ molecule expression of bone marrow-derived DCs as well as interleukin-12 p70 secretion. The IFN-y secreting CTLs induced by HSCT-26 DCs were significantly more than those induced by CT-26 DCs （P=0.002）. The former CTLs＇ specific cytotoxic activity was higher than the latter CTLs＇ at a serial E/T ratio of 10：1, 20：1, and 40：1. Mouse colon cancer model showed that the tumor volume of HSCT-26 DC vaccination group was smaller than that of CT-26 DC vaccination group on tumor volume though there was no statistical difference between them （24 mm^3 vs 8 mm^3, P=0.480）. The median survival time of mice immunized with HSCT-26 DCs was longer than that of those immunized with CT-26 DCs （57 d vs 43 d, P = 0.0384）. CONCLUSION： Heat-shocked tumor cell lysate-pulsed DCs can evoke anti-tumor immune response in vivo effectively and serve as a novel DC-based tumor vaccine.

Heparanase expression,degradation of basement membrane and low degree of infi ltration by immunocytes correlate with invasion and progression of human gastric cancer

AIM： To disclose the mechanisms that accelerate or limit tumor invasion and metastasis in gastric cancer patients. METHODS： The heparanase expression, continuity of basement, degree of infiltration by dendritic cells and lymphocytes in gastric cancer tissues from 33 the early and late stage patients were examined by immunohistochemistry, in situ hybridization and transmission electron microscopy. RESULTS： Heparanase mRNA expression in the late stage patients with gastric cancer was stronger than that in the early stage gastric cancer patients. In the early stage gastric cancer tissues, basement membrane （BM） appeared intact, whereas in the late stage, discontinuous BM was often present. The density of Sl00 protein positive tumor infiltrating dendritic cells （TIDC） in the early stage gastric cancer tissues was higher than that in the late stage. The infiltrating degree of tumor infiltrating lymphocytes （TIL） in the early stage patients whose tumor tissues contained a high density of TIDC was significantly higher than that in the late stage gastric cancer tissues patients with a low density of TIDC. There were few cancer cells penetrated through the continuous BM of cancer nests in the early stage gastric cancers, but many cancer cells were found outside of the defective BM of cancer nests in the late stage. CONCLUSION： Our results suggest that strongheparanase expression is related with the degradation of BM which allows or accelerates tumor invasion and metastasis. However, high density of TIDC and degree of infiltration by TIL are associated with tumor progression in human gastric cancers.

Combinational adenovirus-mediated gene therapy and dendritic cell vaccine in combating well-established tumors

Recent developments in tumor immunology and biotechnology have made cancer gene therapy and immunotherapy feasible. The current efforts for cancer gene therapy mainly focus on using immunogenes, chemogenes and tumor suppressor genes. Central to all these therapies is the development of efficient vectors for gene therapy. By far, adenovirus （AdV）-mediated gene therapy is one of the most promising approaches, as has confirmed by studies relating to animal tumor models and clinical trials. Dendritic cells （DCs） are highly efficient, specialized antigen-presenting cells, and DC- based tumor vaccines are regarded as having much potential in cancer immunotherapy. Vaccination with DCs pulsed with tumor peptides, lysates, or RNA, or loaded with apoptotic/necrotic tumor cells, or engineered to express certain cytokines or chemokines could induce significant antitumor cytotoxic T lymphocyte （CTL） responses and antitumor immunity. Although both AdV-mediated gene therapy and DC vaccine can both stimulate antitumor immune responses, their therapeutic efficiency has been limited to generation of prophylactic antitumor immunity against re-challenge with the parental tumor cells or to growth inhibition of small tumors. However, this approach has been unsuccessful in combating well-established tumors in animal models. Therefore, a major strategic goal of current cancer immunotherapy has become the development of novel therapeutic strategies that can combat well-established tumors, thus resembling real clinical practice since a good proportion of cancer patients generally present with significant disease. In this paper, we review the recent progress in AdV-mediated cancer gene therapy and DC-based cancer vaccines, and discuss combined immunotherapy including gene therapy and DC vaccines. We underscore the fact that combined therapy may have some advantages in combating well-established tumors vis-a-vis either modality administered as a monotherapy.

IL-13Ra2-and glioma stem cell-pulsed dendritic cells induce glioma cell death in vitro

Objective Gliomas are the most common malignant tumors in the central nervous system.Despite multiple therapies including surgery,chemotherapy,and radiotherapy,the prognosis of patients remains poor.Immunotherapy is an alternative method of treating glioma,and the use of dendritic cell vaccines is one of the promising treatment options.However,there is no specific tumor cell antigen that can trigger dendritic cells(DCs).IL-13Ra2 is a specific antigen expressed in glioma cells;in the current study,we have attempted to explore whether IL-13Ra2 could be the antigen that triggers DCs and to envisage its application as potential therapy for glioma.Methods The expression of IL-13Ra2 was detected in U251 glioma cell lines and primary glioma tissues using different methods.DCs from human blood were isolated and pulsed with recombinant IL-13Ra2,following which the cytotoxicity of these DCs on glioma cells was detected and analyzed.Results About 55.9% human glioma tissue cells expressed IL-13Ra2,while normal brain tissue cells did not show any expression.DC vaccines loaded with IL-13Ra2,glioma cell antigen,and brain tumor stem cell(BTSC) antigen could significantly stimulate the proliferation of T lymphocytes and induce cell death in the glioma tissue.Compared to other groups,DC vaccines loaded with BTSC antigen showed the strongest ability to activate cytotoxic T lymphocytes(CTLs),while the glioma cell antigen group showed no significant difference.Conclusion IL-13Ra2,which is expressed in gliomas and by glioma stem cells,as well as IL-13Ra2 could prove to be potential antigens for DC vaccine-based immunotherapy.

Dendritic cell therapy with improved outcome in glioma multiforme―a case report

Malignant gliomas are the most devastating tumors in clinical practice and nave poorest survival, Immunological treatment of such patients may likely increase the survival and quality of life. Dendritic cells （DCs）, most potent antigen presenting cells in combination with oral chemotherapeutic agents may be tried for patients giving consent to such treatment. We have successfully combined the two therapies in an adult male patient who was on downhill course after being operated on once with post operation chemotherapy and radiotherapy for glioma in the left parietal area. He received five dendritic cell therapy vaccines in combination with oral chemotherapy and responded dramatically having near normal quality of life for an additional five months with this regime, increasing the survival after operation to 11 months. This therapy is continuing with radiological betterment of the lesion. The DCs are matured with antigen extracted from wax embedded tissue at 6th day of culture. We feel that the treatment can be given to more number of patients to establish its efficacy for the dreaded cancer glioblastoma multiforme.

Induction of protective antitumor activity of tumor lysate-pulsed dendritic cells vaccine in RM-1 prostate cancer model

Objective： To investigate the antitumor activity of tumor lysate-pulsed dendritic cells vaccine in RM-1 prostate cancer mice model with the survival time of mice calculated and the tumor size measured in DC vaccine therapy. Methods： C57BL/6 mice were immunized on the dorsal flank by s.c. inoculation of Lysate-DC, ova-DC, and non-DC on day -7. On day 0, 2× 10^6cells of RM-1 tumor cells （H-2b） were injected s.c. in C57BL/6 mice pre-treated by s.c. inoculation of modified DCs, correspondingly. DTH assay was performed with modified DCs. In partial test, for the determination of which immune cells were required for antitumor activity, mice were immunodepleted of CD4, CDS, or natural killer （NK） NK1.1 cells with the corresponding monoclonal antibodies. The survival time of nude mice loaded with tumor cells was calculated and the size of tumor measured. Results： In RM-1 mice prostate cancer model, immunized with lysate-DC, compared with ova-DC and non-DC, the pre-infection vaccine resulted in 100% clearance of primary tumors, whereas on day 0 of injection vaccine cleared 40-60% of primary tumors. On day 0, C57BL/6 mice （H-2b） were immunized with Lysate-DC, compared with ova-DC and non-DC by caudal vein injection, then on day 15, RM-1 cells were inoculated. On day 30, average diameters of tumor in different groups of modified DC were 23.7±5.4 mm, 22.1±4.9 mm, 4.3±2.6 mm, respectively. Lysate-DC, compared with ova-DC and non-DC, can greatly depressed RM-1 tumor cell growth （P〈0.01）. The mean survival time of C57BL/6 mice in Lysate-DC, ova-DC and non-DC groups were 15.8±2.6, 16.6±3.2, 39.0±5.6, respectively, and there was a significant difference in the mean survival time in lysate-DC group between ova-DC and non-DC group （P〈0.01）. DTH test showed that lysate-DC could prime T lymphocyte and elicit tumor antigen specific immune response, and over 80% mice in groups of lysate-DC showed obvious swelling in their foot pad. This response was strengthened with repeating inoculation, whereas DTH response was not seen in control group. In vivo depletion of NK cells resulted in a 40-60% reduction in growth suppression within the primary tumor, and depletion of CD4^＋ cells resulted in a 20% reduction in growth suppression. Conclusion： The minor lysate-pulsed dendritic cells vaccine could elicit antitumor activity in RM-1 loaded C57BL/6 mice, and prolong the duration of RM-1 loaded C57BL/6 mice. So DC-based immunotherapy with hormone-refractory prostate carcinoma yielded protective immunity, generated efficient cellular antitumor responses, thereby providing further preclinical support for feasible immunotherapy approaches for prostate cancer.

Anti-tumor effect of CTLs activated by dendritic cells pulsed with K-ras mutant peptide and whole tumor antigen on pancreatic cancer

Objective： We studied the role of specific cytotoxic T lymphocytes （CTLs） activated by dendritic cells （DCs） presenting cationic nanoparticles with the K-ras （12-Val） mutant peptide and whole tumor antigen in the killing of different pancreatic cancer cell lines in vitro and in vitro. Methods： Peripheral blood DCs were induced by rhGM-CSF and IL-4 and cultured. DCs were sensitized by whole antigen of a pancreatic cancer cell line （PANC-1） with expression of K-ras mutant, K-ras mutant peptide （K-ras＋peptide） and cationic nanoparticles with K-ras mutant peptide （K-ras＋peptide-CNP）, respectively. Cell surface markers were measured by flow cytometry. Lymphocyte proliferation was detected by the 3H-TdR test, and ELISAwas performed to detect IFN-y secretion. 125I-UdR was used to measure the killing effect of CTLs. We also evaluated the antitumor activity of CTLs in vivo in a tumor-bearing nude mouse model prepared with the PANC-1 （K-ras＋） and SW1990 （K-ras-） cell lines. Results： Compared with K-ras＋peptide, low concentration K-ras＋pepUde-CNP can be effectively presented by DCs （P 〈 0.05）. CTLs induced by DCs pulsed with whole tumor antigen had significant greater killing effect （P 〈 0.05） on PANC-1 and SW1990 pancreatic cancer cells compared with K-ras＋peptide and K-ras＋peptide-CNP-induced CTLs. CTLs induced by DCs pulsed with K-ras＋peptide and K-ras＋peptide-CNP had a specific killing effect （P 〈 0.05） for PANC-1 and no effect （P 〉 0.05） on SW1990 cell lines （P 〉 0.05）. Conclusion： Cationic nanoparticles with K-ras （12-Val） mutant peptide can be effectively presented by DCs at a low concentration in a short time. CTLs induced by K-ras＋peptide-CNP had specific killing activity for the pancreatic cancer cell line with the K-ras （12-Val） mutant and could significantly inhibit tumor growth and increase the survival time of tumor-bearing nude mice.

Effect of dendritic cell modified by gp96-peptide complex on antitumor effect in H22 cell

Objective： To investigate the antitumor effect of dendritic cell （DC） modified by gp96-peptide complexes both in vitro and in vivo. Methods：Gp96-peptide complexes were acquired from H22 liver cancer cells in mice. DC were cultured from bone marrow cells and modified by gp96-peptide complexes. Spleen lymphocytes of mice were activated by modified DC and the cytotoxicity were detected by ^51Cr release method. Modified DC, gp96-peptide complexes and inactivated H22 cells were injected into mice bearing H22 liver cancer cells to observe the levels of IL-10, IFN-y in serum and the alteration of proportions of CD8^＋-IFNy^＋ and CD8^＋-IL-10^＋ cells, CD4^＋-IFNy^＋ and CD4^＋-IL-10^＋ cells. Results： DC modified by gp96-peptide complexes can activate spleen lymphocyte and the latter can specifically kill H22 cells but not Ehrilich ascites carcinoma cells. Modified DC can improve the host＇s antitumor immune response and the proportions of Thl cells, inhibiting tumor growth. Conclusion： Gp96-peptide complexes can activate DC effectively, making DC a good vaccine.

Enhanced anti-tumor immunity ex vivo induced by GM-CSF gene transducted dendritic cell vaccine

Objective： The aim of the study was to investigate whether dendritic cell （DC） precursors, recruited by injection of chemokine ligand 3 （CCL3）, induce enhanced anti-tumor immunity after granulocyte-macrophage colony stimulating factor （GM-CSF） transfection in mice ex vivo. Methods： The 615 mice were injected with CCL3 via the tail vein. Freshly isolated B220–CD11c＋ cells were cultured with cytokines. For adenoviral （Ad）-mediated gene transduction, DCs were transferred AdGM-CSF gene at different ratios of multiplicity of infection （MOI） to determine the optimal gene transfection conditions, and detecting the expression of GM-CSF after transfection. The variation of GM-CSF gene-modified DCs were analyzed by morphological observation, phenotype analysis, and mixed lymphocyte reaction （MLR）. DCs were loaded with gastric cancer antigen obtained by frozen and thawed method. The stimulated DCs vaccination induced T lymphocytes, and the killing effect of T cells to gastric cancer cells was assayed by MTT. INF-γ production was determined with the INF-γ ELISA kit. Results： B220–CD11c＋ cells numbers increased after CCL3 injection. ELISA results showed that after GM-CSF gene modification, DC could produce high level of GM-CSF. When DCs were transferred AdGM-CSF gene at MOI equal to 1：100, GM-CSF level in culture supernatants reached saturation [（130.00 ± 12.61） pg/mL]. After GM-CSF gene-modification, DCs tended to more maturated through morphological observation and were phenotypically identical to typical DC and gained the capacity to stimulate allogeneic T cells. T lymphocytes stimulated with DC transduced with GM-CSF gene showed the specific killing effect on gastric carcinoma cells and produced high level of INF-γ [（1245.00 ± 13.75） pg/mL]. Conclusion： CCL3-recruited DCs modified by adenovirus-transducted GM-CSF could produce high level of GM-CSF, which tended to more maturated, and the capacity of activating allogeneic T lymphocytes proliferation was enhanced greatly. Moreover, they could stimulate specific cytotoxic T lymphocyte （CTL） to gastric cancer ex vivo.

In vitro study on the morphology of human blood dendritic cells and LPAK cells inducing apoptosis of the hepatoma cell line

Objective To observe in vitro effects and morphological changes of human peripheral blood dendritic cells (DCs) on the ability of lymphokine and phytohaemagglutininum (PHA) activated killer (LPAK) cells to induce apoptosis of the human hepatoma cell line (BEL-7402， B).Methods Experimental groups were divided into LD group (DCs+L+B), L group (L+B)， D group (DCs+B) and B group. The methods of neutral red uptake, ordinary light microscopy, electron microscopy, TDT mediated X-dUTP nick end labeling (TUNEL) were used. Results The difference between the D group and the B group was not distinct (P>0.05). The difference between the LD group and the L group was distinct， with DCs+LPAK >LPAK (P<0.01) in cytotoxity. Apoptotic cells were TUNEL positive in light microscopy, and apoptotic nuclei were stained yellow brown and dark brown, with size and shape varying from cell to cell. Ultrastructural change in apoptotic tumor cells comprised of compaction and condensation of nuclear chromatin， and condensation of cytoplasm and apoptotic bodies. At the same time, LPAK cells manifested the characteristics of autophagic apoptosis, and there were some autophagic bodies in it. Conclusions The combination of human blood DCs and LPAK cells could induce apoptosis of BEL-7402 cells effectively, with some LPAK cells manifesting the characteristics of autophagic apoptosis.

Immunotherapy of DC-CIK cells enhances the efficacy of chemotherapy for solid cancer: a meta-analysis of randomized controlled trials in Chinese patients

Objective： Professional antigen-presenting dendritic cells （DCs） and cytokine-induced killer （CIK） cells, components of anti-cancer therapy, have shown clinical benefits and potential to overcome chemotherapeutic re- sistance. To evaluate whether DC-CIK cell-based therapy improves the clinical efficacy of chemotherapy, we reviewed the literature on DC-CIK cells and meta-analyzed randomized controlled trials （RCTs）. Methods： We searched several databases and selected studies using predeflned criteria. RCTs that applied chemotherapy with and without DC-CIK cells separately in two groups were included. Odds ratio （OR） and mean difference （MD） were reported to measure the pooled effect. Results： Twelve reported RCTs （826 patients）, which were all performed on Chinese patients, were included. Combination therapy exhibited better data than chemotherapy： 1-year overall survival （OS） （OR=0.22, P〈0.01）, 2-year OS （OR=0.28, P〈0.01）, 3-year OS （OR=0.41, P〈0.01）, 1-year disease-free survival （DFS） （OR=0.16, P〈0.05）, 3-year DFS （OR=0.32, P〈0.01）, objective response rate （ORR） （OR=0.54, P〈0.01）, and disease control rate （DCR） （OR=0.46, P〈0.01）. Moreover, the levels of CD3＋ T-lymphocytes （MD=-11.65, P〈0.05） and CD4＋ T-lymphocytes （MD=-8.18, P〈0.01） of the combination group were higher. Conclusions： Immunotherapy of DC-CIK cells may enhance the efficacy of chemotherapy on solid cancer and induces no specific side effect. Further RCTs with no publishing bias should be designed to confirm the immunotherapeutic effects of DC-CIK cells.

Dendrimer-based nanoparticles in cancer chemotherapy and gene therapy

This review discusses recent studies on dendrimer-based nanoparticles in cancer chemotherapy and gene therapy. In order to achieve the high efficacy and low side effects of chemotherapy and gene therapy, it is essential to combine the unique features of dendrimers and the specific tumor microenvironment to target delivery and control release of therapeutic agents to tumor tissues and cells. Strategies to design the dendrimer-based delivery system in this review include non-modified dendrimers, dendrimer conjugates, assembled amphiphilic dendrimers, nanohybrid dendrimer carriers and dendrimers with inherent activity. In addition, specific functional groups on these dendrimers as stimuli-responsive system for targeting delivery and controlled release of therapeutic agents are discussed.

Recent therapeutic applications of the theranostic principle with dendrimers in oncology

At the intersection between treatment and diagnosis, nanoparticles technologies are strongly impacting the development of both therapeutic and diagnostic agents.Consequently, the development of novel modalities for concomitant noninvasive therapy and diagnostics known as theranostics as a single platform has gained significant interests. These multifunctional theranostic platforms include carbon-based nanomaterials（e.g., carbon nanotubes）, drug conjugates, aliphatic polymers, micelles, vesicles, core-shell nanoparticles, microbubbles and dendrimers bearing different contrast agents and drugs, such as cytotoxic compounds in the oncology domain. Dendrimers emerged as a new class of highly tunable hyperbranched polymers, and have been developed as useful theranostic platforms. Magnetic resonance imaging, gamma scintigraphy, computed tomography and optical imaging are the main techniques developed with dendrimers in the theranostic domain in oncology. Different imaging agents have been used such as Gd（Ⅲ）,19F, Fe2O3（MRI）,76Br（PET）,111In,88Y,153Gd,188Re,131I（SPECT）,177Lu,gold（CT） and boronated groups, siliconnaphthalocyanines,dialkylcarbocyanines and QDs（optical imaging dyes）.