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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An ependymoma was induced in the brain of a BD-IX rat by repeated doses of MNU. In vitro grown cells of the tumor were fibroblasts and stellate cells considered to be glial. Reimplantation of these cells into the brain of another BD-IX rat resulted a tumor growing in the meninges. This tumor was then repeatedly transplanted over several passages. Its gross morphology resembled that of a sarcoma; however, glial in cells could be demonstrated with silver methods. A cell line derived from the first transplanted tumor group proved to contain S-100 protein in traces in the first passages in vitro. Explanted cells of the primary ependymoma were cloned. Two clones were established, RGL 1 and RGL 2. The cells of both clones resembled morphologically the stellate elements of the primary explant. RGL 1 contained S-100 protein. It was cloned again in the 16th subpassage. Four clones were established. Only 1 contained S-100 protein in traces. The clone RGL 1 had a subdiploid karyotype with a modal number of 39 and a large submetacentric marker. It was subcloned in the 25th passage with two clones, both having a karyotype of 41 chromosomes.
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PMID:In vitro growth of neoplastic rat glial cells. 12 46

The various stages of divergent neuroepithelial differentiation were studied in the solid transplants of a transplantable mouse testicular teratoma (OTT-6050) maintained in both ascitic and solid forms. They included: a) areas of undifferentiated medullary epithelium corresponding to the rare human medulloepithelioma; b) areas of neuroblastic differentiation corresponding to neuroblastoma, with more mature neuronal differentiation corresponding to ganglioneuroma or, when mixed with glial elements, to ganglioglioma; and c) more mature neuroglial areas resembling astrocytoma, oligodendroglioma or ependymoma, as well as more primitive areas corresponding to ependymoblastoma. In tissue culture using collagen-coated coverslips, astrocytic differentiation was found in the outgrowth zone after 15 days, confirmed by immunofluorescence with antibodies to an astroglia-specific protein. In organ culture systems, glial components, including ependymal structures, were preserved in tumor explants, and astrocytic differentiation, as expressed by glial fiber formation, was increased after 4 to 6 weeks in vitro. No neuronal differentiation was demonstrable, however. The neuroepithelial component of this experimental teratoma may provide a model for the study of neoplastic neuroepithelial differentiation.
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PMID:An experimental mouse testicular teratoma as a model for neuroepithelial neoplasia and differentiation. I. Light microscopic and tissue and organ culture observations. 16 76

Tumors of the human nervous system (neuroblastomas, an ependymoma, a medulloblastoma, and a Schwannoma) obtained during surgery have been cultured organotypically by the method of Wolff. The tumors retained characteristic morphology, organization and patterns of behavior in vitro, and one neuroblastoma gave rise to a growing long-term culture. Long-term organotypic culture, where maintenance of tissue organization and growth occur together, is recommended for the study of neoplasms of the nervous system.
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PMID:Organ culture of human nervous system tumors. 17 38

Newborn hamsters were inoculated intracerebrally with BK virus. Between 3 and 6 months after inoculation, they developed papillary ependymoma (8 hamsters, 42%) or functional malignant islet cell tumors of the pancreas (insulinoma, 8 hamsters), or both (1 hamster). Both tumors contained an antigen reactive to SV40 T-antibody, suggesting that at least a part of BK virus genomen has been integrated into the tumor cells. No infectious virus was detected in the extract of these tumors.
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PMID:Induction of papillary ependymomas and insulinomas in the Syrian golden hamster by BK virus, a human papovavirus. 19 23

Ependymomas were produced in 44 of 50 Syrian golden hamsters and in 9 of 31 outbred Swiss mice inoculated intracerebrally with high-titer, purified BK virus (BKV). Tumors contained a T-antigen that reacted with BKV-specific T-antibody in immunofluorescence and complement-fixation tests. A proportion of tumor-bearing animals had antibodies to BKV T-antigen in their sera. BKV could be rescued from two tumor cell lines by Sendal virus-mediated fusion with Vero cells. A low, or lack of, oncogenic activity was displayed by BKV inoculated sc, ip, or iv.
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PMID:High incidence of ependymomas induced by BK virus, a human papovavirus: brief communication. 19 71

BK virus (BKV), a human papovavirus, was inoculated iv into 3-week-old Syrian golden hamsters. Between 2 1/2 and 9 months after inoculation, 82% of the animals developed tumors. The induced neoplasms were ependymoma, carcinoma of the pancreatic islets, osteosarcoma, adenocarcinoma, angiosarcoma, angioma, lymphoma, and seminoma. Hypersecretion of insulin, glucagon, C-peptide, and calcitonin was detected in tumors of pancreatic islets. BKV etiology of tumors was supported by the following evidence: 1) No tumors with BKV-specific markers appeared in animals given injections of buffer, animals inoculated with BKV neutralized by anti-BKV-specific serum, or uninoculated controls; 2) BKV tumor (T) antigen was detected by immunofluorescence and complement fixation tests in tumors of animals inoculated with infectious BKV and in transplanted tumors; 3) antibodies to BKV T-antigen were detected in sera of animals bearing primary or transplanted tumors; 4) BKV could be activated by Sendai virus-mediated fusion of neoplastic cells with susceptible Vero cells; and 5) no endogenous hamster oncornaviruses were found in tumors.
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PMID:Ependymomas, malignant tumors of pancreatic islets, and osteosarcomas induced in hamsters by BK virus, a human papovavirus. 21 Dec 43

In order to locate the target cells for malignant transformation by BK virus (a human papova virus) in hamster brain, electron microscopic observation of tumor originally induced in hamster brain by BK virus was performed. With light microscopy, the BK virus-induced tumor (Vn 17) bore a close resemblance to human malignant ependymoma. Under the electron microscope, numerous microvilli and few cilia were visible on the surface of the tumor cells. These tumor cells were joined to each other by desmosomes. Gap junctions were not observed. Multilayered cuboidal cells were observed around the lumen and blood vessels in the tumor. With regard to fine structure, three types of Vn 17 cells were recognized; ependymal like cells, tanycytes with prominent cell processes, and undifferentiated cells with few cytoplasmic organelles. There was no basal lamina between the ependymal cells and the connective tissue stroma. The Vn 17 cells showed some similarity to the ultrastructural features of the epemdymal cells of newborn rabbits, suggesting that the target cells for Vn 17 may be cells related to ependyma. Malignant transformation of the cells would be initiated in the early stages after BK virus inoculation into the brain of newborn hamsters.
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PMID:Electron microscopic features of a brain tumor induced in hamster by BK virus, a human papova virus. 23 94

Tumors of the fourth ventricle, particularly ependymomas, may grow out of the ventricular cavity into the cerebellopontine angle cistern and the subarachnoid cisterns. The angiographic changes will then suggest both the intra- and extraventricular location of the tumors. The ependymoma is the most prone of the fourth ventricle tumors to demonstrate this pattern of growth.
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PMID:Extra-axial growth of fourth ventricle tumors - angiographic changes. 30 Apr 73

A case is discussed in which the patient presented with a primary extradural sacrococcygeal ependymoma and synchronous pulmonary metastasis. The clinical course has been characterized by recurrent pulmonary metastases. Management has consisted of repeated surgical resections of the pulmonary metastases and the tumor at the primary site; and the use of a wide spectrum of chemotherapeutic agents. Transplantation of this tumor into nude mice initially resulted in rapid growth but there was spontaneous regression in the second transplants. A general discussion of the management of such lesions is presented, and the literature pertaining to this tumor is discussed.
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PMID:Metastasizing extradural ependymoma of the sacrococcygeal region: case report and review of literature. 37 64

The literature on chemical induction and natural occurrence of neurogenic tumors in mice and some unpublished data from our laboratories are reviewed. Neurogenic tumors are a minor component of the total tumorigenic response of mice to alkylating agents such as ENU and MNU. In comparison with rats, a given dose of ENU induces a much lower incidence of neurogenic tumors in mice, and the mean latency is much longer than in rats. Although most neurogenic tumors induced by ENU in mice by either transplacental or direct postnatal exposure are of glial or Schwann cell origin, as in rats, and occur most frequently in the cerebrum or cranial nerves, respectively, medulloblastomas of the cerebellum also occur in treated mice. Transplacental and neonatal exposure to ENU were much more effective in inducing neurogenic tumors than treatment later in life. Ependymomas were not seen in mice, although they are common in ENU-treated rats. Neuroblastoma of the adrenal medulla, a common human pediatric tumor, has not been induced to either species, but it does occur spontaneously in mice. The induction by ENU of medulloblastomas demonstrates that this rodent equivalent of an embryonal tumor of the human nervous system can result from exposure to exogenous chemical agents.
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PMID:Transplacental and neonatal induction of neurogenic tumors in mice: comparison with related species and with human pediatric neoplasms. 38 62


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