Genomic DNA analysis of rat retinal tumor induced by adenovirus type 12.

To elucidate the pathogenesis of human retinoblastoma, we investigated the genomic expression in retinal tumors induced by human adenovirus type 12 in rats, using various DNA probes. Seven rats received a single intraocular inoculation of concentrated virus fluid within 24 hours after birth. Intravitreous tumors were induced in two out of seven animals (28.5%) within 30 to 64 days after the inoculation. A remarkably uniform histologic feature, i.e., neuroblastic cells in association with Homer-Wright pseudorosettes, was present in all cases. The adenovirus-related oncoprotein gene E1A and human retinoblastoma susceptibility gene were detected in the tumors by Southern blot hybridization. In situ hybridization analysis demonstrated expression of adenovirus type 12 E1A gene in the inner granular layer of the retina. It was suggested that integration of adenovirus type 12 E1A fragment with the host genome and expression of the gene were required for induction of this tumor.     

Production of xenoantiserum to a chemically induced murine tumor: analysis of tumor specificity in different immune tests.

The method of in vivo absorption of xenoantisera raised against murine chemically-induced tumors has been used to obtain specific anti-tumor sera. To assess if the tumor specificity was maintained under different experimental conditions, the sera were employed in in vitro tests based on different immunologic reactions. In vivo absorption results in the production of xenoantisera which are highly specific for the immunizing tumor and that lack antibody activity toward histocompatibility and organ specific antigens and endogenous virus antigens. Thus, in vivo absorbed antisera appear to be valuable reagents for the immunochemical characterization of chemically-induced tumors.     

Inhibitory effects of biochanin A on mouse lung tumor induced by benzo(a)pyrene.

Biochanin A, an isoflavone compound, is reported to have an inhibitory effect on benzo(a)pyrene [B(a)P] metabolism. We examined the modifying effect of biochanin A on in vivo carcinogenesis using a mouse lung tumor model. As carcinogens, a single subcutaneous injection of 0.5mg of B(a)P was given within 24 hours after birth. The test groups were injected with 0.125mg of biochanin A in 0.1ml DMSO by i.p. 3 times a week for 6 weeks after weaning. All mice were sacrificed at week 9 and the incidence and multiplicity of lung tumors were examined. Concomitant administration of biochanin A showed a significant inhibitory effect on the incidence of tumor-bearing mice (12.5%, P < 0.01), as well as the mean number of tumors (0.13, P < 0.001), compared with the group treated with B(a)P alone in which the incidence was 57.1% and the mean number was 1.0. These results suggest that biochanin A has inhibitory potential on the development of mouse lung tumor induced by B(a)P.     

肿瘤细胞诱导血小板聚集的机理

Lewis肺癌细胞(3LL),黑色素瘤细胞(B16a)与绒毛膜上皮癌细胞(NHCh-4)能引起人血小板的聚集反应,但聚集的强度与波型不同。胶质母细胞瘤细胞,(NHC-3)与直肠癌细胞(NHC-6)不引起血小板的聚集反应。抗血小板膜糖蛋白(GP)Ⅱb/Ⅲa的单克隆抗体SZ-21抑制3LL引起的血小板聚集,抗GPIb的单克隆抗体AN51能部分抑制NHCh-4诱导的聚集。NHCh-4能刺激血小板生成TXP_2。3LL与B16a对血小板TXB_2生成的影响很小。结果表明,不同的肿瘤细胞引起血小板聚集的能力和机理各不相同,血小板在不同肿瘤转移中所起的作用也不一样。     

肿瘤细胞冻融裂解物上清对凋亡细胞负载的树突状细胞生物学特性的作用研究

目的:探讨Balb/c小鼠骨髓瘤SP2/0细胞冻融裂解物上清对SP2/0凋亡细胞负载的骨髓来源的树突状细胞(DC)的成熟、生物学特性及功能的影响。方法: 采用小鼠重组粒细胞-巨噬细胞集落刺激因子(GM-CSF)和白介素4(IL-4)诱导骨髓来源的DC, 100Gyγ射线辐照诱导SP2/0细胞凋亡, 与未成熟DC共育16-20h;SP2/0细胞冻融裂解物上清和脂多糖(LPS)分别作用于DC48h。采用免疫荧光标记和流式细胞术分析DC表型;[³H]-TdR掺入试验和[⁵¹Cr]释放试验测定DC刺激T细胞增殖和细胞杀伤效应。采用腹股沟皮下DC主动免疫治疗SP2/0荷瘤小鼠, 每间隔14d治疗1次, 共3个疗程, 观察肿瘤生长情况及小鼠生存期。结果:(1)经SP2/0冻融裂解物上清和脂多糖(LPS)诱导凋亡肿瘤细胞负载的DC高表达共刺激分子CD40、CD80、CD86和MHC-Ⅱ分子, 但抗原摄取能力均下降;(2)SP2/0冻融裂解物上清组和LPS组DC体外刺激T细胞增殖和激活CTL能力均高于对照组(P＜0.05);(3)经SP2/0冻融裂解物上清组主动免疫治疗小鼠存活期长于其它各组(P＜0.05)。结论:小鼠SP2/0细胞冻融裂解物上清可诱导凋亡细胞负载的树突状细胞成熟, 能够刺激T细胞增殖和激发肿瘤特异性细胞毒性T淋巴细胞(CTL), 主动免疫治疗可激发荷瘤小鼠体内有效的肿瘤特异性免疫力, 延长荷瘤小鼠生存期。     

Cell-surface antigens induced by avian RNA tumor viruses: detection by a cytotoxic microassay

A microcytotoxicity test for chicken embryo cells was introduced to search for new antigens after the infection of these cells with avian leukosis and sarcoma virus strains. At least two kinds of antigens could be demonstrated: (i) a subgroup-specific, presumably viral envelope (Ve) antigen on the surface of all avian tumor virus-infected chicken cells and (ii) a group-specific tumor-specific surface antigen (TSSA) common to all avian sarcoma virus transformed chicken cells regardless of the virus subgroup. A strong anti-TSSA response could also be elicited in chickens by the injection of either an avian leukosis virus strain or a nonconverting mutant of an avian sarcoma virus. In this assay system, the cytotoxic effect acting via the TSSA was considerably stronger than the one acting via the Ve antigen alone.     

Isolation and structural analysis of peptide mimotopes for the disialoganglioside GD2, a neuroblastoma tumor antigen

The disialoganglioside GalAcbeta1-4(NeuAcalpha2-8NeuAcalpha2-3)Galbeta1-4Glcbeta1-1Cer (GD2) is expressed on various tumors, including neuroblastoma, and was defined as a relevant tumor antigen. The monoclonal anti-GD2 antibody 14.18 is widely used for diagnostic purposes in neuroblastoma, and in its mouse/human chimeric form (ch14.18) now enters passive immunotherapeutic regimens in phase II clinical trials. This study aimed to generate structural mimics of the 14.18 epitope of GD2. Therefore, we used the ch14.18 antibody for selecting immunoreactive GD2 peptide mimotopes from a decamer phage display library. In all, 13 GD2 peptide mimics could be determined by biopanning and their specificity was demonstrated by exclusive recognition by the ch14.18 antibody. Furthermore, their nature of being GD2 mimics and their degree of mimicry was confirmed by competition with the natural antigen. When performing a comparative visualization of the GD2 epitope and selected mimotopes using a three-dimensional computer modeling system (BALLView), we demonstrated fitting of the GD2 molecule and the mimotopes in the antigen-binding pouch of a GD2 specific antibody. Moreover, the computer modeling argued for optimal affinity of the GD2 mimotopes. We thus provide evidence that the generation of GD2 peptide mimotopes is successful when using the neuroblastoma antibody ch14.18 for selection, and that this approach might offer a tool to develop a vaccination strategy against this malignant pediatric tumor.     

乙烯雌酚诱导的大鼠垂体瘤模型的建立

目的:观察己烯雌酚诱导大鼠垂体瘤成瘤的稳定性,为后继研究提供实验基础。方法:60只标准Wistar-Furth大鼠随机分成己烯雌酚注射组、灭菌花生油注射组和对照组,每组20只,观察处理后大鼠一般情况、体重及行为学改变,并分别于4周、8周、和12周处死大鼠,观察成瘤情况和垂体重量变化,HE染色及免疫组化染色的方法鉴别肿瘤类型及CD31表达。结果:处理后2周,己烯雌酚注射组大鼠体重增长明显较其余2组缓慢,并出现脱毛、行动缓慢等表现。在相应时点处死大鼠,实验组出现肿瘤形成,4周、8周和12周成瘤率分别为30%、90%和100%,其余2组成瘤率为0。HE染色可见异常细胞。免疫组化鉴别均为催乳素(PRL)腺瘤,部分混杂促肾上腺皮质激素(ACTH)。实验组垂体组织无论成瘤与否,CD31阳性表达率与对照组相比差异显著。成瘤与否跟大鼠性别无关。结论:腹腔注射己烯雌酚诱导Wistar-Furth大鼠垂体瘤模型成瘤效果确切稳定。在成瘤过程中,部分指标出现动态变化,可以作为进一步研究的模型。     

Macrophage-mediated tumor lysis induced by loach egg lectin

Vertebrate lectin purified from loach egg was tested for induction of tumor lysis mediated by macrophages. Loach egg lectin lysed tumor cells but not normal spleen cells in cooperation with BCG- or glucan (TAK)-elicited peritoneal macrophages of mice. Corynebacterium parvum-, OK432-, glycogen-, lipopolysaccharide-elicited or resident macrophages were not effective. Neither loach egg lectin nor BCG nor glucan macrophages alone had a cytolytic action on tumor cells. Thus, the vertebrate lectin from loach egg is a mediator in macrophage-mediated tumor lysis, inducing binding of macrophages to target cells. This lectin-dependent macrophage-mediated cytolysis (LDMC) was inhibited by galactose, N-acetylgalactosamine, fucose, or rhamnose. These results suggest that tumor cells can be recognized via glycoconjugates on cell membrane in addition to tumor-associated antigen and that some animal lectins participate in macrophage-mediated tumor lysis.     

A framework for power analysis using a structural equation modelling procedure

Background  

This paper demonstrates how structural equation modelling (SEM) can be used as a tool to aid in carrying out power analyses. For many complex multivariate designs that are increasingly being employed, power analyses can be difficult to carry out, because the software available lacks sufficient flexibility.     

艾氏腹水瘤全细胞瘤苗诱导的特异性杀伤活性

目的研究艾氏腹水瘤全细胞瘤苗诱导的特异性杀伤活性。方法用40g/L的多聚甲醛处理的艾氏腹水瘤细胞作为全细胞瘤苗免疫Balb/c小鼠,建立瘤苗小鼠模型。用HE染色法对亲本肿瘤细胞皮下再次攻击形成的肿瘤结节进行病理学观察;用51Cr释放法测定瘤苗免疫组、荷瘤组、正常组小鼠脾细胞,对亲本艾氏腹水瘤细胞和Sp2/0细胞的杀伤活性。结果HE染色显示,经瘤苗免疫后亲本肿瘤细胞皮下再次攻击形成的肿瘤结节中,瘤细胞几乎完全坏死,同时在坏死部位有大量炎细胞浸润、纤维母细胞和小血管增生;而对照组则无以上现象。效靶比为200∶1时,免疫小鼠脾细胞体外杀伤亲本艾氏腹水瘤细胞的杀伤率(％)为(42.3±3.2)％,显著高于荷瘤组的(12.1±2.3)％、正常组的(6.1±1.1)％和对Sp2/0细胞的杀伤率(8.8±0.4)％(P均∨0.05)。结论艾氏腹水瘤全细胞瘤苗可诱导机体产生特异性杀伤活性。     

Quantitative analysis of the immunogenic activity of SV40 virus and of tumor cells induced by this virus

A study of specific antitumor immunity created in Syrian hamsters by oncogenic virus SV40 and by tumor cells induced by the same virus showed that the level of specific resistance depends on the immunizing dose of virus and cells. Investigation of the resistance-inducing activity of a wild strain of SV40 virus showed that the minimal dose inducing resistance in hamsters was ten times higher than for the tsA-30 mutant of the virus. The minimal resistance-inducing dose of irradiated cells of a tumor induced by the same strain of SV40 virus was 9·10⁵ cells; a tenfold increase in the dose led to a significant increase in the level of specific antitumor immunity.Laboratory of Immunology of Tumors, Oncologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR L. M. Shabad.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 8, pp. 223–225, August, 1978.