Autologous hybrid cell fusion vaccine in a spontaneous intermediate model of breast carcinoma

Breast cancer is among the most common malignancies affecting women and reproductively intact female dogs, resulting in death from metastatic disease if not treated effectively. To better manage the disease progression, canine mammary tumor (CMT) cells derived from malignant canine mammary cancers were fused to autologous dendritic cells (DCs) to produce living hybrid-cell fusion vaccines for canine patients diagnosed with spontaneous mammary carcinoma. The high-speed sorting of rare autologous canine patient DCs from the peripheral blood provides the autologous component of fusion vaccines, and fusion to major histocompatibility complex-unmatched CMT cells were produced at high rates. The vaccinations were delivered to each patient following a surgical resection 3 times at 3-week intervals in combination with immuno-stimulatory oligonucleotides and Gemcitabine adjunct therapy. The immunized patient animals survived 3.3-times longer (median survival 611 days) than the control patients (median survival 184 days) and also appeared to exhibit an enhanced quality of life. A comparison of vaccinated patients diagnosed with inflammatory mammary carcinoma resulted in a very short median survival (42 days), suggesting no effect of vaccination. The data showed that the development of autologous living DC-based vaccine strategies in patient animals designed to improve the management of canine mammary carcinoma can be successful and may allow an identification of the antigens that can be translatable to promote effective immunity in canine and human patients.

Tat-based cell-cell fusion method for screening HIV-1 fusion inhibitors / 生物工程学报

An HIV-1 cell-cell fusion system was developed to screen HIV-1 entry inhibitors that block cell-cell fusion. In this system, the pEGFP-Tat plasmid was constructed and cotransfected into effector cells (HEK-293T) with HIV-1 envelope plasmid. TZM-bl cell, a genetically engineered cell line that expresses CD4, CXCR4, CCR5 as well as Tat-inducible β-galactosidase and luciferase reporter gene, was used as target cell. Thus, the co-culture of target cells and effector cells allows the cell fusion via Env and the activity of the fusion inhibitor can be quantified by measuring the reporter protein expression. The experimental parameters were optimized and 11 anti-HIV-1 agents including CCR5 antagonist maraviroc, reverse transcription inhibitor zidovudine (AZT) and integrase inhibitor raltegravir were tested. The result showed that the system exhibited high specificity and sensitivity. Two of eight tested anti-HIV-1 agents were found to block the cell-cell fusion. The system is suitable for efficient screening of HIV-1 cell-cell fusion inhibitors.

Propofol promotes osteoclastic bone resorption by increasing DC-STAMP expression

BACKGROUND: Propofol is an intravenous anesthetic which has antioxidant effects due to its similarity in molecular structure to α-tocopherol. It has been reported that α-tocopherol increases osteoclast fusion and bone resorption. Here, we investigated the effects of propofol on signaling pathways of osteoclastogenic gene expression, as well as osteoclastogenesis and bone resorption using bone marrow-derived macrophages (BMMs). METHODS: BMMs were cultured with macrophage colony-stimulating factor (M-CSF) alone or M-CSF plus receptor activator of nuclear factor kappa B ligand (RANKL) in the presence of propofol (0–50 µM) for 4 days. Mature osteoclasts were stained for tartrate-resistant acid phosphatase (TRAP) and the numbers of TRAP-positive multinucleated osteoclasts were counted. To examine the resorption activities of osteoclasts, a bone resorption assay was performed. To identify the mechanism of action of propofol on the formation of multinucleated osteoclasts, we focused on dendritic cell-specific transmembrane protein (DC-STAMP), a protein essential for pre-osteoclastic cell fusion. RESULTS: Propofol increased the formation of TRAP-positive multinucleated osteoclasts. In addition, the bone resorption assay revealed that propofol increased the bone resorption area on dentin discs. The mRNA expression of DC-STAMP was upregulated most strongly in the presence of both RANKL and propofol. However, SB203580, a p38 inhibitor, significantly suppressed the propofol/RANKL-induced increase in mRNA expression of DC-STAMP. CONCLUSION: We have demonstrated that propofol enhances osteoclast differentiation and maturation, and subsequently increases bone resorption. Additionally, we identified the regulatory pathway underlying osteoclast cell-cell fusion, which was enhanced by propofol through p38-mediated DC-STAMP expression.

Effect of remifentanil on pre-osteoclast cell differentiation in vitro

BACKGROUND: The structure and function of bone tissue is maintained through a constant remodeling process, which is maintained by the balance between osteoblasts and osteoclasts. The failure of bone remodeling can lead to pathological conditions of bone structure and function. Remifentanil is currently used as a narcotic analgesic agent in general anesthesia and sedation. However, the effect of remifentanil on osteoclasts has not been studied. Therefore, we investigated the effect of remifentanil on pre-osteoclast (pre-OCs) differentiation and the mechanism of osteoclast differentiation in the absence of specific stimulus. METHODS: Pre-OCs were obtained by culturing bone marrow-derived macrophages (BMMs) in osteoclastogenic medium for 2 days and then treated with various concentration of remifentanil. The mRNA expression of NFATc1 and c-fos was examined by using real-time PCR. We also examined the effect of remifentanil on the osteoclast-specific genes TRAP, cathepsin K, calcitonin receptor, and DC-STAMP. Finally, we examined the influence of remifentanil on the migration of pre-OCs by using the Boyden chamber assay. RESULTS: Remifentanil increased pre-OC differentiation and osteoclast size, but did not affect the mRNA expression of NFATc1 and c-fos or significantly affect the expression of TRAP, cathepsin K, calcitonin receptor, and DC-STAMP. However, remifentanil increased the migration of pre-OCs. CONCLUSIONS: This study suggested that remifentanil promotes the differentiation of pre-OCs and induces maturation, such as increasing osteoclast size. In addition, the increase in osteoclast size was mediated by the enhancement of pre-OC migration and cell fusion.

Confirm fusion cell line by STR technology of parentage identification / 中国医师杂志

Objective To screen and confirm cell fusion by DNA technology of parentage identification based on detecting of short tandem repeats.Methods With 20％ polyethylene glycol (PEG)-6000,human myeloma cell lines and health individual peripheral blood mononuclear cell were fused.Then selected by hypoxantin,aminopterin,thymidin (HAT) medium,and fusion cell were sub-cloned.Morphology of fusion cells was checked by regular microscope.Concentration of DNA was compared to parental cells.Allele genes,identified by short tandem repeats,of fusion cell line were sequenced and compared with each other.Results The fused cells from myeloma cell line and peripheral blood mononuclear cell (PBMC) were slightly larger than primary cells,and the proliferation cycle was not changed significantly.DNA concentration of the fused cell DNA was increased by two times.Sequences of short tandem repeats (STR) showed that the fused cell included all original genetic materials of parent cells.Conclusions DNA technology of parentage identification is a convenient and reliable method to screen and confirm fused cell.

In vitro study on the induction of antigen-specific cytotoxic T lymphocytes by fusion of dendritic cells with pancreatic canec r MiaPaCa-2 cells / 中华胰腺病杂志

Objective To investigate the ability of inducing antigen-specific cytotoxic T lymphocytes (CTL) stimulated by dendritic cell (DC) fused with MiaPaCa-2 cells in vitro.Methods DC were isolated and cultured from peripheral blood mononuclear cells (PBMCs).50%PEG and 10%DMSO were used to fuse MiaPaCa-2 cells and DC, and DC co-cultured with MiaPaCa-2 cells and DC alone served as control .The fusion efficiency was assessed by flow cytometry ( FCM) and DC-MiaPaCa-2 hybrids were identified as PE-MUC1/FITC-CD86 double positive cells . The survival rate of DC was determined by MTT method . The lymphocyte proliferation stimulated by DC in vitro was evaluated by mixed cell culture with DC in different ratios of 1∶10, 1∶20 and 1∶80.IL-2, IL-10, granzyme B and IFN-γreleased by antigen-specific CTLs were measured by ELISA assay.Results The fusion rate in DC fused with MiaPaCa-2 cells ( fused cells ) was ( 42 .30 ± 7.30)%, which was higher than (7.21 ±1.06)% in DC co-cultured with MiaPaCa-2 cells ( co-cultured cells).The cell viability of DC, co-cultured cells and fused cells was >95.0%, 85.0% and 62.8%, and fused cells had greatly lower cell viability than DC and co-cultured cells (P0.05).At the co-culture ratio of 1∶10, IL-2 secreted by CTL in DC, co-cultured and fused cells was (27.30 ±5.21 ),(897.44 ±93.05),(2 243.80 ±381.46) ng/L; IL-10 was (19.55 ± 2.05), ( 424.60 ±108.25 ), ( 706.53 ±161.29 ) ng/L; Granzyme B was ( 16.23 ±1.23 ), ( 451.07 ± 120.50),(1327.77 ±205.15)ng/L;IFN-γwas (30.11 ±4.32)、(982.00 ±124.68)、(2421.04 ±488.50) ng/L.Cytokines from the antigen-specific CTL induced by DC fused with MiaPaCa-2 cells were significantly higher than those by DC and DC co-cultured with MiaPaCa-2 cells ( all P<0.05).Conclusions The fusion of DC and pancreatic cancer MiaPaCa-2 cells could stimulate tumor antigen-specific CTL in vitro .

Investigation of the pathogenesis of cell fusion in multiple myeloma bone disease / 白血病·淋巴瘤

Objective To discuss function of the fusion cells of human bone marrow stromal cells (BMSCs) and human myeloma cell RPMI 8226 in the pathogenesis of multiple myeloma bone disease.Methods The cells,labeled by cell tracer green fluorescent probe (CMFDA) and red fluorescent probe (CMTMR),respectively,were induced into fusion by chemical polyethylene glycol (polyethyleneglycol,PEG-1000),and cell fusion model was set up.Whether fusion cells had nucleus fusion was determined by Karyotype analysis.The expressions of stemness-related genes,SIRP α gene and DC-STAMP gene in fusion cells were identified.Results Polyethylene glycol (PEG-1000) could mediate the integration of BMSCs and RPMI 8226 cells.The number of chromosomes in more than 80 ％ the hybrid cells was about 80.Fusion cells not only showed that BMSCs,stemness-related genes of c-myc,Klf-4 and OCT-4 genes expressed positively,but also the fusion-related genes SIRPα and DC-STAMP expressed positively.Conclusion BMSCs and RPMI 8226 cells can form fusion cells,and the cells have the potential for further integration,which is one of the important reasons for the promotion of muhiple myeloma bone destruction.

Malignant transformation of fusion cells derived from co-culturing human glioma cell line SU3 with murine macrophages / 中华微生物学和免疫学杂志

Objective To investigate whether the malignant transformation of macrophages ( Mφ) in glioma mesenchyme was induced by the fusion of glioma cells ( SU3 ) and Mφ.Methods SU3 cells transfected with red fluorescent protein genes were co-cultured in vitro with Mφexpressing enhanced green fluorescent protein.The cell lineages with RFP+/GFP+dual-color fluorescence were established by using monoclonal selection method.A series of tests for analyzing cancer-related phenotypes, tumorigenicity and specific markers for murine macrophage were performed.Results (1) A few of dual-color fluorescent cells were observed in the co-culture.Three monoclonal cell lineages (C3, C4 and C12) were obtained success-fully.(2) Three types of cells including RFP+, EGFP+and RFP+/EGFP+cells were formed during the cul-ture of monoclonal C12 cell lineage.The percentage of EGFP+cells was increased along the extended culture time and increased passages.Then, EGFP+cells gradually became the predominant cell population.Nota-bly, the percentage of RFP+/EGFP+cells were decreased and maintained at a low level, but the RFP+cells almost disappeared.(3) EGFP+cells from monoclonal C12 cell lineage showed the malignant characteristics such as loss of contact inhibition, rapid proliferation andchromosome aneuploidy, as well as high tumorigenic rate in nude mice (5/5).They also expressed macrophage specific marker CD68 and showed a large number of telocentric chromosomes.Conclusion The results of this study suggested that the malignant transforma-tion of host macrophages as previously observed in solid tumor might be induced by cell fusion occurred be-tween human glioma cells and macrophages.Along with the previous evidences showing the isolation of the malignantly transformed macrophages ( ihCTC) from solid tumor tissue of tumor-bearing mice, the results confirmed an objective existence of malignant transformation of host macrophages in tumor microenvironment. The malignant transformation of host cells induced by fusion with tumor cells revealed not only a new under-standing for the progression of tumor and cancer heterogeneity, but also new targets for cancer therapy.

Analyses of Entry Mechanisms of Novel Emerging Viruses Using Pseudotype VSV System

Emerging infectious diseases include newly identified diseases caused by previously unknown organisms or diseases found in new and expanding geographic areas. Viruses capable of causing clinical disease associated with fever and bleeding are referred to as viral hemorrhagic fevers (VHFs). Arenaviruses and Bunyaviruses, both belonging to families classified as VHFs are considered major etiologies of hemorrhagic fevers caused by emerging viruses; having significant clinical and public health impact. Because these viruses are categorized as Biosafety Level (BSL) 3 and 4 pathogens, restricting their use, biological studies including therapeutic drug and vaccine development have been impeded. Due to these restrictions and the difficulties in handling such live viruses, pseudotype viruses bearing envelope proteins of VHF viruses have been developed using vesicular stomatitis virus (VSV) as a surrogate system. Here, we report the successful developments of two pseudotype VSV systems; bearing the envelope proteins of Lujo virus and severe fever with thrombocytopenia syndrome (SFTS) virus, both recently identified viruses of the family Arenaviridae and Bunyaviridae, respectively. My presentation will summarize the characterization of the envelope proteins of Lujo virus including its cellular receptor use and cell entry mechanisms. In addition, I will also present a brief introduction of SFTS reported in Japan and the diagnostic studies in progress using these newly pseudotype VSV system.

Analyses of entry mechanisms of novel emerging viruses using pseudotype VSV system

Emerging infectious diseases include newly identified diseases caused by previously unknown organisms or diseases found in new and expanding geographic areas. Viruses capable of causing clinical disease associated with fever and bleeding are referred to as viral hemorrhagic fevers (VHFs). Arenaviruses and Bunyaviruses, both belonging to families classified as VHFs are considered major etiologies of hemorrhagic fevers caused by emerging viruses; having significant clinical and public health impact. Because these viruses are categorized as Biosafety Level (BSL) 3 and 4 pathogens, restricting their use, biological studies including therapeutic drug and vaccine development have been impeded. Due to these restrictions and the difficulties in handling such live viruses, pseudotype viruses bearing envelope proteins of VHF viruses have been developed using vesicular stomatitis virus (VSV) as a surrogate system. Here, we report the successful developments of two pseudotype VSV systems; bearing the envelope proteins of Lujo virus and severe fever with thrombocytopenia syndrome (SFTS) virus, both recently identified viruses of the family Arenaviridae and Bunyaviridae, respectively. My presentation will summarize the characterization of the envelope proteins of Lujo virus including its cellular receptor use and cell entry mechanisms. In addition, I will also present a brief introduction of SFTS reported in Japan and the diagnostic studies in progress using these newly pseudotype VSV system.

The fusion and division during osteoclasts formation / 中华骨科杂志

Objective To investigate the formation and special cell biological behavior of osteoclasts.Methods The live-cell imaging technology was adopted to consecutively and dynamically observe the whole process of multinuclear osteoclast formation induced by RANKL and M-CSF from rat peripheral blood monocyte.Meanwhile,the inverted phase contrast microscopy,TRAP staining,and scanning electron microscopy were also applied to identify the osteoclast.Results After 2-week cultivation,a great number of apocytes were found by the inverted phase contrast microscopy,and most apocytes and monocytes had positive reaction after TRAP staining.Moreover,many bone resorption lacunae in which osteoclasts were perhrming bone resorption function could be found in the bone slice under the scanning electron microscope.Live-cell imaging observation showed that the multinuclear osteoclasts were generated through self-fusion of monocytes,fusion of monocytes and apocytes,as well as fusion between apocytes.All fusion processes occurred under the condition of cell adherence.Time-lapse Microcinematography observation showed diverse shapes of osteoclasts and the cell division of multinuclear osteoclasts.Conclusion Rat peripheral blood monocyte can develop into osteoclast under induction of RANKL and M-CSF.Osteoclast can form gigantic apocyte via various types of cell fusion to increase its nucleus number and cell volume,vary its shape,and increase the area of plasma membrane.On the other hand,osteoclast can decrease its cell volume and nucleus number via cell division to adapt the needs of local morphology,biomechanics and bone resorption dynamics.It suggests that this non-mitosis cell division is a special cell biological behavior of osteoclast,which may be the basis of exerting its function and improving bone resorption efficiency.

Stimulation of Allogenic lymphocytes by Dendritic Cells Derived from Human Umbilical Cord Blood Fused with Breast Cancer Stem Cells.

Aims: Cancer stem cells (CSCs) are cancer cells that possess characteristics associated with normal stem cells. CSCs represent a minor subset of cells in the tumor and are thought to be the reason for the initiation of disease, resistance to cancer treatment, and the occurrence of metastasis. Therefore, breast cancer stem cells (BCSCs) targeting therapies are considered as the promising therapy for breast cancer treatment. This research aims to evaluate the tumor associated antigens presentation of dendritic cells fused with breast cancer stem cells in dendritic cells based therapies. Methodology: Human breast cancer stem cells are isolated from malignant breast tumors by enrich culture and fluorescent activated cell sorting. Human dendritic cells are isolated from umbilical cord blood by culturing CD14 monocytes in induced medium. Electrocution is used to fuse breast cancer stem cells and dendritic cells. Fusion cells are used to evaluate functions of dendritic cells (DCs) and also to stimulate T cells. Results: These findings indicate that fusion cells have the ability to present the antigens of breast cancer stem cell to T-cells, and regarding functionality. Conclusion: They appear to be very good candidates for antitumor vaccine in breast cancer.

Mutational analysis of conserved amino acids in the fusion-promoting domain of Newcastle disease virus hemgglutinin-neuraminidase protein / 中华微生物学和免疫学杂志

Objective To determine the function of conserved amino acids in the fusion-promoting domain of Newcastle disease virus (NDV) hemagglutinin-neuraminidase (HN) protein,clearly understanding mechanism of cell fusion.MethodsUsing a PCR-based site-directed mutagenesis method and the method of homology recombination occurred in vivo to change six conservative amino acids into alanine respectively.Wild type (WT) and all mutant HN proteins were exepressed in BHK-21 cells by the vacciniaT7 RNA polymerase expression system.The amount of each HN protein at the cell surface was determined by fluorescence-activated cell sorter (FACS).Cell fusion efficiency,hemadsorption activity (or receptor binding activity) and neuraminidase activity were determined.Results There was no statistic difference of cell surface expression among WT and each mutant HN protein ( P＜0.05 ).Cell fusion efficiency of each mutant protein decreased to some extent,especially 1103A decreased to 14.2％ in head.Hemadsorption activity of mutant proteins were reduced in different extent,the maximum reduction of which was also 1103A,28.2％ of wt NDV HN.There was different neuraminidase activity among each mutant HN protein.L74A increased slightly to 118.6％.L110A decreased most to 5.2％.I103A decreased second most to 5.7％.Conclusion Conserved amino acids in fusion-promoting domain of NDV HN played an important role in cell fusion.I103 was identified as a key amino acid in this domain.

Defining the function of the N-linked glycosylation site of hantavirus GM04-38 in cell fusion / 中华微生物学和免疫学杂志

ted in a loss of cell fusion,which suggests the 928 site on G2 is crucial for cell fusion and the fusion peptide is likely on G2.

Progress on the origin of hepatocyte stem cell / 国际外科学杂志

Generally speaking,the hepatocyte stem cell is not a specific cell type.but an overall name of all kinds of cells that possess stem cell characters about embryonic development and regeneration of liver.HSC is a pluripotential stem cells which have self-renewal capacity and could differentiate into mature hepatocytes and bile duct cells.According to the different origin of hepatocyte stem cell,it can be usually divided into two kinds:non liver-derived hepatocyte stem cell and liver-derived hepatocyte stem cell.

Effects of N-linked glycosylation on specific cell fusion in rubella virus / 中华微生物学和免疫学杂志

Objective To explore the effects of glycosylation in E2 and E1 protein on specific cell fusion in rubella virus(RV)strain JR23.Methods Site-directed mutagenesis was used tO obtain mutants containing new enzyme sites on the E2 and E1 gene of RV JR23.All the mutants and wild type proteins were expressed in BHK21 cells and treated with acid medium to induce specific cell fusion.The fusion functions were assayed with Giemsa staining and reporter gene method for qualitative and quantitative analysis,respectively.Expression efficieneies of mutant proteins on cell surface were quantified with fluorescence-activated cell sorter(FACS).Hemadsorption assays were performed to detect binding activity of mutant proteins qualitatively and quantitatively.Results Mutant proteins E2 N53G,S73I and S131V had 62.73%,66.66%and 55.12% of fusion activities,and E1 T78A,T179A and T211A had 66.93%,87.33%and 90.18%of fusion activities,respectively,as compared with the wild type protein.The FACS indicated that the expression efficiencies of all the mutant proteins except E2 S131V were lower than that of the wild type protein.Hemadsorption assays demonstrated that binding abilities of E2 S73I and E1 T78A decreased slightly,but that of the other four mutant proteins Wns almost same as the wild type protein. Conclusion Glycosylation on E2 N53,N71,N129 and E1 N76 were important for the specific cell fusion,but E1 N177 and N209 were almost not.

Meiotic arrest compromises pollen fertility in an interspecific hybrid between Brachiaria ruziziensis x Brachiaria decumbens (Poaceae: paniceae)

Microsporogenesis was analyzed in an interspecific hybrid between an artificially tetraploidized sexual accession of Brachiaria ruziziensis (2n=4x=36) and a natural apomictic tetraploid accession of B. decumbens. Syncytes involving a large number of cells were recorded in 15.4 percent of meiocytes. Meiosis progressed normally in syncytes during prophase I; in metaphase I, however, several nuclei were found fusioned, showing chromosome stickiness and several chromosome fragments. Meiosis was arrested in metaphase I and pycnotic nuclei and micronuclei were formed. Abnormal cytokinesis fractionated the syncyte into abnormal meiotic products that were covered by the pollen wall. Meiocytes in leptotene were recorded in all the slides prepared for both meiotic divisions, and abnormal "pollen grains" with well-developed pollen wall but containing leptotene nuclei were recorded in 9.18 percent of grains analyzed. These findings suggested that the meiocytes received the signal to enter meiosis but lacked the signal to proceed beyond leptotene. Despite the absence of the meiotic process, such cells were covered by pollen grain wall. Total pollen sterility resulted from these abnormalities combined with still others observed among meiocytes.

A microsporogênese de um híbrido interespecífico entre um acesso sexual tetraploidizado artificialmente de Brachiaria ruziziensis (2n=4x=36) e um acesso apomítico tetraplóide natural de B. decumbens (2n=4x=36) foi analisada. Sincícios envolvendo um grande número de células foram encontrados em 15,40 por cento dos meiócitos. A meiose progrediu normalmente nos sincícios durante a prófase I; em metáfase I, todavia, muitos núcleos fundiram-se, mostrando ainda aderências cromossômicas e inúmeros fragmentos. O processo meiótico foi interrompido na metáfase I, quando a cromatina formou núcleos picnóticos. Citocineses anormais fracionaram os sincícios em produtos meióticos anômalos que foram recobertos pela parede do grão de pólen. Meiócitos em leptóteno também foram observados durante todo o processo meiótico e grãos de pólen anormais com parede de pólen bem desenvolvida, mas contendo núcleos leptotênicos, foram observados em 9,18 por cento dos grãos de pólen analisados. Os resultados sugerem que os meiócitos receberam o sinal para entrar em meiose, mas não receberam o sinal para prosseguir além do leptóteno. Apesar da ausência de processo meiótico completo, os meiócitos foram cobertos pela parede do grão de pólen. Estas anormalidades, combinadas com outras causadas pela poliploidia, resultaram em total esterilidade de pólen.

Preparation and biological characteristics of renal cell carcinoma-dendritic cell fusion vaccine / 重庆医科大学学报

Objective:To prepare renal cell carcinoma-dendritic cell fusion vaccines,and observe the biological characteristics of the fusion cells,to provide theoretical basis and experimental data for further research of DC based cancer vaccines. Methods:The renal cell carcinoma and dendritic cells were fused by using polyethylene glycol(PEG). The growth curve of fusion cells,morphological characteristics,expression of costimulation molecules,abilities to amplify T lymphocytes and grow into new tumors were detected. Results:Renal cell carcinoma and dendritic cells could be fused effectively by PEG.The fusion cells had weak proliferation abilities and were unable to grow into new tumors in immunol-deficiency animals,but the costimulation molecules expression such as CD86 and HLA-DR and the abilities to irritate the proliferation of T lymphocytes were remarkably increased than that of parental control groups(P

Microsporogenesis in Brachiaria dictyoneura (Fig. & De Not.) Stapf (Poaceae: Paniceae)

icrosporogenesis was analyzed in five accessions of Brachiaria dictyoneura presenting x = 6 as the basic chromosome number. All accessions were tetraploid (2n = 4x = 24) with chromosome pairing in bi-, tri-, and quadrivalents. The recorded meiotic abnormalities were those typical of polyploids, including precocious chromosome migration to the poles, laggard chromosomes, and micronucleus formation. The frequency of these abnormalities, however, was lower than those reported for other polyploid accessions previously analyzed for other Brachiaria species. Cell fusion and absence of cytokinesis were also recorded in some accessions, leading to restitutional nucleus formation in some cells. Genetically unbalanced microspores, binucleate, and 2n microspores were found among normal meiotic products as results from these abnormalities. The limitation in using these accessions as pollen donor in interspecific crosses with sexual species with x = 7 or x = 9 in breeding programs is discussed.

In vitro and in vivo anti-tumor effects of dendritic cell vaccines sensitized by NCI-H460 lung cancer cell line / 中国肿瘤生物治疗杂志

DC group.IL-12 secretion in IL-18/fusion group was higher than that in the fusion group,and IL-12 in the pulsed DC group was higher than that in the DC group.The in vitro killing rates of the 4 groups were 79.73%,50.68%,35.81% and 4.05%,respectively.Tumor forming time in IL-18/fusion group([12.82?2.85]d) was longer than those in the pulsed DC group([8.52?1.97]d,P