首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Malignant progressor tumors are only weakly immunogenic and can evade host recognition and rejection. One approach to therapy involves activation of the host antitumor cellular effector mechanisms. Since monoclonal antibodies to CD3 (anti-CD3) can activate T cells in vitro, an attempt was made to determine if tumor immunity could be achieved by the administration of anti-CD3 in vivo. T lymphocytes from mice injected with anti-CD3 showed increased interleukin-2 receptor (IL-2R) expression, increased proliferation to recombinant IL-2 (rIL-2), and enhanced reactivity in both an allogeneic mixed lymphocyte reaction and a mixed lymphocyte tumor culture. Malignant tumor growth in treated mice was also examined. The anti-CD3 treatment prevented tumor outgrowth that would have killed untreated animals and also stimulated an in vivo response against a malignant progressor tumor providing lasting tumor immunity.  相似文献   

2.
New method for detecting cellular transforming genes   总被引:24,自引:0,他引:24  
Tumor induction in athymic nude mice can be used to detect dominant transforming genes in cellular DNA. Mouse NIH 3T3 cells freshly transfected with either cloned Moloney sarcoma proviral DNA or cellular DNA's derived from virally transformed cells induced tumors when injected into athymic nu/nu mice. Tumors were also induced by cells transfected with DNA from two tumor-derived and one chemically transformed human cell lines. The mouse tumors induced by human cell line DNA's contained human DNA sequences, and DNA derived from these tumors was capable of inducing both tumors and foci on subsequent transfection. Tumor induction in nude mice represents a useful new method for the detection and selection of cells transformed by cellular oncogenes.  相似文献   

3.
Tumor detection by nuclear magnetic resonance   总被引:25,自引:0,他引:25  
Spin echo nuclear magnetic resonance measurements may be used as a method for discriminating between malignant tumors and normal tissue. Measurements of spin-lattice (T(1)) and spin-spin (T(2)) magnetic relaxation times were made in six normal tissues in the rat (muscle, kidney, stomach, intestine, brain, and liver) and in two malignant solid tumors, Walker sarcoma and Novikoff hepatoma. Relaxation times for the two malignant tumors were distinctly outside the range of values for the normal tissues studied, an indication that the malignant tissues were characterized by an increase in the motional freedom of tissue water molecules. The possibility of using magnetic relaxation methods for rapid discrimination between benign and malignant surgical specimens has also been considered. Spin-lattice relaxation times for two benign fibroadenomas were distinct from those for both malignant tissues and were the same as those of muscle.  相似文献   

4.
Second-passage rat embryo cells were transfected with a neomycin resistance gene and the activated form of the c-Ha-ras I gene, or with these two genes plus the adenovirus type 2 E1a gene. Foci of morphologically transformed cells were observed in both cases; however, the frequency of transformation was at least ten times higher with two oncogenes than with the ras gene alone. All the transformed cell lines gave rise to rapidly growing tumors when injected subcutaneously into nude mice. All but one of the cell lines transformed by the ras oncogene alone formed metastatic nodules in the lungs of animals that had been injected subcutaneously with transformed cells. When transformed cells were injected intravenously, all the ras single-gene transformants gave rise to many metastatic lung nodules. In contrast, cell lines transformed with ras and E1a did not generate metastases after subcutaneous injection and gave rise to very few metastatic lung nodules after intravenous injection. These data demonstrate that a fully malignant cell with metastatic potential, as measured in an immunodeficient animal, can be obtained from early passage embryo cells by the transfection of the ras oncogene alone.  相似文献   

5.
Neurofibromatosis type 1 (NF1) is a prevalent familial cancer syndrome resulting from germ line mutations in the NF1 tumor suppressor gene. Hallmark features of the disease are the development of benign peripheral nerve sheath tumors (neurofibromas), which can progress to malignancy. Unlike humans, mice that are heterozygous for a mutation in Nf1 do not develop neurofibromas. However, as described here, chimeric mice composed in part of Nf1-/- cells do, which demonstrates that loss of the wild-type Nf1 allele is rate-limiting in tumor formation. In addition, mice that carry linked germ line mutations in Nf1 and p53 develop malignant peripheral nerve sheath tumors (MPNSTs), which supports a cooperative and causal role for p53 mutations in MPNST development. These two mouse models provide the means to address fundamental aspects of disease development and to test therapeutic strategies.  相似文献   

6.
Murine tumor cells were induced to phagocytize either Candida albicans or group A streptococcal cells. The presence of microbial particles within the tumor cell cytoplasm had no effect on in vitro tumor cell growth. However, when Candida albicans-infected tumor cells were injected into syngeneic mice, they formed tumors that grew faster, invaded the surrounding normal tissue more rapidly and metastasized more rapidly than control tumor cells. Tumor cells infected with group A streptococcal particles did not grow faster or show increased malignant behavior. These data indicate that the in vivo behavior of malignant tumor cells can be modulated by microbial particles, which are often present in the microenvironment of the growing tumor.  相似文献   

7.
Human papovavirus (JC): induction of brain tumors in hamsters   总被引:40,自引:0,他引:40  
Eighty-three percent of hamsters inoculated at birth with JC virus, a human papovavirus isolated from brain tissue of a case of progressive multifocal leukoencephalopathy, developed malignant gliomas within 6 months. Three brain tumors have been serially transplanted as subcutaneous tumors. JC virus was isolated from five of seven tumors tested. Cells from four tumors were cultivated in vitro. These cells contained an intranuclear antigen with the characteristics of a T antigen, and this antigen was antigenically related to SV40 T antigen. Although virus was not recovered from extracts of serially cultured tumor cells, JC virus was rescued when one tumor cell line was fused with permissive cells.  相似文献   

8.
The graft versus host reaction which occurs in F(1) hybrid mice injected with parental spleen cells was used to examine several immunological theories of neoplasia. Long-term survivors of this reaction developed lymphoid neoplasms which resembled Hodgkin's disease and lymphosarcoma. Mice with these tumors were chimeras, but the parental cells present within their spleens had specific immunological tolerance toward host antigens. This, together with the finding that the tumors were transplantable only to isogenic recipients, indicates that the tumors were of host rather than donor origin.  相似文献   

9.
Cells of the 10T 1/2 mouse fibroblast line transformed in vitro by ultraviolet radiation are antigenically similar to those from skin cancers produced in mice by repeated exposure to ultraviolet radiation. Both types of tumor cells grew preferentially in ultraviolet-irradiated syngeneic mice relative to untreated animals, and both were recognized by ultraviolet radiation-induced tumor-specific suppressor lymphocytes. These properties were not shared by 10T 1/2 cells transformed in vitro by x-rays or 3-methylcholanthrene.  相似文献   

10.
Lipid extracts from the pituitary gland of cattle were prepared which, when injected into a pure strain of white mice, caused development of malignant tumors in 26.8 per cent of the 67 animals injected, which corresponds with the numerical results obtained by investigators working with human liver extracts. Evidently the carcinogenic power of these lipid extracts is low. The tumors developed chiefly in organs at a distance from the site of injection, exhibiting various histological types including carcinoma as well as sarcoma. The tumors developed at an earlier date after injection of extracts from the anterior lobe as compared with those developing after injection of the posterior lobe extracts, the average period of time necessary for their development being 9.3 months for the anterior lobe extracts and 14 months for posterior lobe extracts.  相似文献   

11.
目的 探讨超声造影时间-强度曲线定量参数在乳腺良、恶性肿瘤鉴别诊断意义.方法 选取27例乳腺肿瘤患者进行超声造影,应用时间-强度曲线定量技术(伽马系数变值)检测乳腺肿块中心和边缘区域灌注参数(峰值时间、峰值强度、曲线下面积及平均通过时间),比较良、恶性肿瘤不同区域灌注参数的差异.结果 27例经病理检查证实良性13例,恶...  相似文献   

12.
Cytostructural localization of a tumor-associated antigen   总被引:2,自引:0,他引:2  
Tumor cell membrane glycoproteins may be involved in the induction of tumor immunity or in the escape of tumors from immunologic defense mechanisms. Forty-four benign and malignant breast lesions were examined for the presence of a carbohydrate precursor antigen (T antigen) of the human blood group system MN. T antigen was demonstrated by means of an immunohistochemical technique to detect tissue binding of peanut agglutinin, a plant lectin, with affinity for T antigen. Malignant breast lesions showed a pattern of T antigen expression different from that of benign breast tissues. A possible role for T antigen in the modulation of the immune response to breast carcinoma is suggested.  相似文献   

13.
重组新城疫病毒对肝癌肺转移鼠的治疗效果   总被引:1,自引:0,他引:1  
文章利用重组新城疫病毒(rNDA)治疗肝癌肺转移鼠,将免疫调节基因白细胞介素2(IL2)插入rNDV基因组,拯救获得rNDV-IL2。MTT法检验rNDV-IL2对肝癌HepG2细胞体外抑制效果。通过小鼠尾静脉注射H22肝癌细胞,构建肝癌细胞肺转移模型,腹腔注射rNDV和rNDV-IL2,治疗肝癌肺转移模型小鼠。结果表明,rNDV-IL2有效感染HepG2细胞,表达外源基因IL2并抑制HepG2细胞增殖。重组新城疫病毒rNDV-IL2治疗试验动物后,体内IL2基因表达量提高,重组新城疫病毒有效控制转移灶形成,且显著促进T细胞增殖,提高试验动物存活率,未治疗组、rDNV载体治疗组和rNDV-IL2治疗组30 d成活率分别为0、50%和77.8%。  相似文献   

14.
80只1日龄Avian鸡,随机人灵实验组和对照组,每组40只,自1日龄开始,实验组鸡肌肉注射胸腺因子D(TFD),剂量2mg/kg,对照组注射生理盐水,隔日注射,共5次。试验期42d,观察TFD对肉鸡生长、免疫及血液中某些激素影响。表明1)注射TFD可显著促进Avian鸡生长,2)23日龄时实验组鸡的外周血T淋巴细胞百分率极显著高于对照组(P〈0.01)。3)实验组在28日龄时血浆甲状腺素(T4)  相似文献   

15.
Chromosome banding analysis of human malignant melanoma has documented the nonrandom alteration of chromosome 6. To determine the relevance of chromosome 6 abnormalities in melanoma, a normal chromosome 6 was directly introduced into melanoma cell lines. The resulting (+6) microcell hybrids were significantly altered in their phenotypic properties in culture and lost their ability to form tumors in nude mice. The loss of the chromosome 6 from melanoma microcell hybrids resulted in the reversion to tumorigenicity of these cells in mice. The introduction of the selectable marker (psv2neo) alone into melanoma cell lines had no effect on tumorigenicity. These results support the idea that one or more genes on chromosome 6 may control the malignant expression of human melanoma.  相似文献   

16.
Oncogenes encoding serine/threonine or tyrosine kinases were introduced into the established rodent fibroblast cell line NIH 3T3 and tested for tumorigenic and metastatic behavior in T cell-deficient nude mice. Transforming oncogenes of the ras family were capable of converting fibroblast cell lines to fully metastatic tumors. Cell lines transformed by the kinase oncogenes mos, raf, src, fes, and fms formed experimental metastases and (in some cases) these genes were more efficient at metastatic conversion than a mutant ras gene. In contrast, cells transformed by either of two nuclear oncogenes, myc or p53, were tumorigenic when injected subcutaneously but were virtually nonmetastatic after intravenous injection. These data demonstrate that, in addition to ras, a structurally divergent group of kinase oncogenes can induce the metastatic phenotype.  相似文献   

17.
用银染法对41例针吸乳腺良恶性肿瘤细胞的AgNOR进行了形态定量研究,结果显示:乳腺癌细胞中AgNOR的数量明显高于良性肿瘤(P<0.001),且乳腺癌细胞AgNOR表现为大小不一,形态不规则及分布无规律性。提示AgNOR的数量、大小、形态及分布均反映了不同肿瘤的生物学特性。因此,AgNOR的定量对乳腺肿瘤针吸细胞学鉴别诊断具有重要的参考价值.  相似文献   

18.
The epidermal growth factor (EGF) receptor gene EGFR has been placed in a retrovirus vector to examine the growth properties of cells that experimentally overproduce a full-length EGF receptor. NIH 3T3 cells transfected with the viral DNA or infected with the corresponding rescued retrovirus developed a fully transformed phenotype in vitro that required both functional EGFR expression and the presence of EGF in the growth medium. Cells expressing 4 x 10(5) EGF receptors formed tumors in nude mice, while control cells did not. Therefore, the EGFR retrovirus, which had a titer on NIH 3T3 cells that was greater than 10(7) focus-forming units per milliliter, can efficiently transfer and express this gene, and increased numbers of EGF receptors can contribute to the transformed phenotype.  相似文献   

19.
目的评价超声联合钼靶X线检查在乳腺良恶性肿瘤鉴别诊断中的应用价值。方法经病理证实的168个乳腺肿瘤术前均行超声及钼靶X线检查,评估两种诊断方法及联合应用的灵敏度、特异度、阳性预测值、阴性预测值及诊断符合率。结果 168个乳腺肿瘤中,良性113个,恶性55个。除钼靶对恶性肿瘤钙化的显示率高于超声之外(P〈0.01),两者在其余指标的检测差异均无统计学意义(P〉0.05)。二者联合诊断乳腺良恶性肿瘤的特异度、阳性预测值及符合率均优于单用超声、钼靶,差异均有统计学意义(P〈0.01或0.05)。结论超声和钼靶X线联合应用可显著提高乳腺肿瘤的诊断符合率。  相似文献   

20.
Oncogenesis of the lens in transgenic mice   总被引:37,自引:0,他引:37  
Neoplastic tumors of the ocular lens of vertebrates do not naturally occur. Transgenic mice carrying a hybrid gene comprising the murine alpha A-crystallin promoter (-366 to +46) fused to the coding sequence of the SV40 T antigens developed lens tumors, which obliterated the eye cavity and even invaded neighboring tissue, thus establishing that the lens is not refractive to oncogenesis. Large-T antigen was detected early in lens development; it elicited morphological changes and specifically interfered with differentiation of lens fiber cells. Both alpha- and beta-crystallins persisted in many of the lens tumor cells, while gamma-crystallin was selectively reduced. Accessibility, characteristic morphology, and defined protein markers make this transparent epithelial eye tissue a potentially useful system for testing tumorigenicity of oncogenes and for studying malignant transformation from its inception until death of the animal.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号