Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Injection of RF virus (RFV), a papovavirus isolated from human urine, into newborn Syrian hamsters induced subcutaneous sarcomas in 50% of the recipients with 18- to 48-week latent periods. Transplantation of 2 X 10(6) primary RFV-induced tumor cells into weaning hamsters caused tumors in 100% of the recipients within 1-2 weeks. Continuous tissue culture cell lines were established from two primary tumors; one of these was transplantable. An in vitro-transformed continuous cell line (RF-194) obtained by infection of primary hamster embryo fibroblasts with RFV was transplantable in weaning hamsters. Neither infectious RFV nor virion antigens were detected in transformed cells. No RFV was recovered when transformed cells were fused with permissive, human embryo kidney cells by means of inactivated Sendai virus. Immunoperoxidase staining was used to show that all three RFV-transformed cell lines contained an intranuclear T-antigen closely similar to that of simian virus 40(SV40)-infected cells. Most hamsters (84%) with primary or transplanted RFV tumors responded with antibodies that reacted with RFV T-antigen and the T-antigen of SV40-infected cells. Likewise, hamster antisera against SV40 T-antigen cross-reacted with RFV T-antigen. Adsorption of RFV T-antisera with an excess of lyophilized SV40-transformed cells removed all detectable activity against SV40 T-antigen but left significant activity against RFV T-antigen. The reciprocal adsorption produced an antiserum spedicic for SV40 T-antigen. Thus human and simian papovavirus T-antigens were related but immunologically separable.
 ...
PMID:Induction of tumors in Syrian hamsters by a human renal papovavirus, RF strain. 6 61

GM54VA human cells transformed by simian virus 40 (SV40) were fused with peritoneal macrophages obtained from three different mouse strains. All 27 hybrid clones studied were positive for SV40 tumor antigen in 100% of their cells and contained human chromosome 17. Human chromosome 17 was the only human chromosome present in five of the hybrid clones. Fusion of GM54VA cells and either thymidine kinase (EC 2.7.1.75)-deficient mouse or Chinese hamster fibroblasts resulted in the growth in hypoxanthine-aminopterin-thymidine medium of hybrid clones positive and negative for SV40 tumor antigen. Counterselection of the hybrid clones positive for tumor antigen in medium containing 5-bromodeoxyuridine resulted in the growth of hybrid cells that were negative for tumor antigen. These experiments indicate that negative for tumor antigen. These experiments indicate that SV40 is integrated in only one of the two parental human chromosomes 17. Because the genome of SV40 has been assigned to human chromosome 7 in two other SV40-transformed human cell lines, at least two different integration sites for SV40 would seem to be present in human cells: one located in human chromosome 7 and the other located in human chromosome 17.
 ...
PMID:Assignment of the integration site for simian virus 40 to chromosome 17 in GM54VA, a human cell line transformed by simian virus 40. 18 10

Beta-emitting radionuclides are important constituents of isotope inventories in light water reactors and may pose an inhalation hazard to industrial workers or the general population if they are released. To study the biological effects of such potential exposures, a series of life span studies was initiated in which beagle dogs were exposed to aerosols of relatively insoluble fused clay particles containing 90Y, 91Y, 144Ce or 90Sr. Groups of dogs exposed to each radionuclide received graded initial lung burdens of radioactivity. When combined with the varied physical half-lives of the four radionuclides, this resulted in a wide variety of radiation doses and dose patterns to the lung. Deaths (greater than 640 days after exposure) were generally associated with pulmonary neoplasia in dogs that inhaled 91Y, 144Ce or 90Sr. These dogs had cumulative lung doses to death greater than 20 000 rads. Exposure to 144Ce or 90Sr with dose rates that decreased slowly induced pulmonary haemangiosarcomas. Pulmonary irradiation from 91Y, with a rapidly decreasing dose rate, resulted in pulmonary epithelial tumours. No malignant lung tumours have been seen within 1540 days after exposure to 90Y. The animals in the main studies have been observed for 1342 to 2756 days after exposure.
 ...
PMID:Comparative pulmonary carcinogenicity of inhaled beta-emitting radionuclides in beagle dogs. 19 66

Nucleated cells (Ehrlich ascites tumor cells or L strain cells) and human red blood cells (RBC)-ghosts were mixed and fused by ultraviolet-inactivated HVJ (Sendai virus). The cell mixture was stained with FITC conjugated anti-RBC ghost antiserum and then applied to FACS II apparatus. The apparatus sorted mononuclear cells fused with RBC-ghosts from the cell mixture on the basis of both the light scattering and fluorescence profiles. When the same procedure was carried out on a mixture containing cells and intact human RBC, the cells sorted by this method were cells into which hemoglobin had been injected. The sorted cells were capable of forming colonies in culture. This sorting method may be useful for collecting cells in which macromolecules have been injected artificially by fusion of RBC-ghosts enclosing macromolecules.
 ...
PMID:An attempt to separate mononuclear cells fused with human red blood cell-ghosts from a cell mixture treated with HVJ (Sendai virus) using a fluorescence activated cell sorter (FACS II). 20 48

Mouse teratocarcinoma cells from the OTT6050 ascites tumor were established in tissue culture and selected for 5-bromodeoxyuridine (BrdUrd) resistance. The embryonal carcinoma cells grew without a feeder layer, remained deficient for thymidine kinase (EC 2.7.1.75), and differentiated like the original tumor into various tissues after subcutaneous injection into 129 mice. We fused the BrdUrd-resistant mouse teratocarcinoma cells with HT1080-6TG human diploid fibrosarcoma cells deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8) and selected for hybrid cells in hypoxanthine/aminopterin/thymidine medium. The resulting hybrid cells segregated human chromosomes quickly and retained one to three human chromosomes including chromosome 17 that carries the human genes for thymidine kinase and galactokinase (EC 2.7.1.6). Single hybrid cells from five independent clones containing human chromosome 17 were injected into mouse blastocysts bearing several genetic markers that affect the coat color phenotype and strain-specific enzyme variants in order to detect tissue differentiation derived from the injected cells. After the injection of single hybrid cells into a total of 103 experimental blastocysts that had been surgically transferred to pseudopregnant foster mothers, 49 mice were born and 2 of them clearly revealed coat mosaicism. In 2 of 17 mice thus far analyzed, the injected hybrid cells proved to be capable of participating substantially in development of seven different organs. However, human gene products have not yet been detected unequivocally in those tissues and weak human-specific galactokinase activity could be recovered only from two mosaic tissues. Our results demonstrate that, after in vitro culture and selection, at least some of the human-mouse hybrid cells still retain their in vivo potential to differentiate and become functionally integrated in the living organism. It now seems feasible to cycle mouse teratocarcinoma cells carrying human genetic material through mice via blastocyst injection to study human gene expression during differentiation.
 ...
PMID:Chimeric mice derived from human-mouse hybrid cells. 20 75

The process of glycocalyx formation by the trilaminar membrane was investigated at the subcellular level by use of cultivated cancer cells derived from a human stomach adenocarcinoma. Glycocalyx was apparently synthesized on the characteristic trilaminar membrane of Golgi-derived vesicles which gave rise to cytoplasmic vacuoles which, in turn, fused to form an intracytoplasmic cyst. Characteristic microvilli similar to those of intestinal epithelium extended from the membrane lining the intracytoplasmic cyst. These ultrastructural features agree with earlier histochemical findings in suggesting intestinal metaplasia in the origin of the gastric tumor. The morphologic features of the cancer cells clearly indicated that glycoprotein is first synthesized in the Golgi complex and fully formed mucoprotein then emerges as membrane-bound glycocalyx in the vesicles budding from the Golgi stacks. The glycocalyx layer is an integral part of the external leaflet of the characteristic trilaminar membrane. Abundant deposits of glycocalyx in the intracytoplasmic cyst constituted the ultrastructural basis for a distinctive type of signet ring cell that differed from mucous signet ring cells derived from goblet cells.
 ...
PMID:Deviated formation of intestinal glycocalyx in human stomach cancer cells. Another type of signet ring cell. 20 29

Carcinoembryonic antigen (CEA) was purified from tumor tissue under mild conditions at neutral pH by a procedure that utilized affinity chromatography on concanvalin A. Further purification by gel filtration provided CEA in 10 to 20% yield and 10% purity. Antibody to this preparation was rendered specific for CEA by adsorption on a column of normal liver proteins bound to Sepharose. On reaction by immunodiffusion against a crude tumor extract, the adsorbed antibody produced two precipitin lines, of which one was relatively weak. These two precipitin lines fused completely with the two respective lines produced by antibody to perchloric acid-treated CEA. The major antigen found in crude tumor extracts and in CEA preparations purified at neutral pH was nearly undetectable in perchloric acid extracts of tumor homogenates. Further investigations showed that 60 to 70% of the CEA in crude tumor extracts and in preparations isolated at netural pH is destroyed and/or becomes insoluble acidic conditions.
 ...
PMID:The isolation of carcinoembryonic antigen from tumor tissue at neutral pH. 24 82

The effect of cytoplasm upon the expression of tumorigenicity was examined with a pair of mouse and a pair of Chinese hamster cell lines, in intraspecies cybrids formed by reciprocal fusions between either tumorigenic or nontumorigenic cells and cytoplasms derived from them. With the mouse cells, 3T3 and the simian virus 40-transformed line SVT2, the cybrid clones were tumorigenic when SVT2 cells were fused with 3T3 cytoplasts, but not in the reciprocal fusion. With the hamster cells, CHEF/18 and the spontaneous transformant CHEF/16, however, tumorigenicity was partially suppressed in cybrid clones formed by fusion of tumorigenic CHEF/16 cells with CHEF/18 cytoplasts; cybrids were nontumorigenic in the reciprocal fusion. Thus, cybrid analysis has shown that tumorigenicity is not cytoplasmically transmitted in these two cell pairs, but suppression of tumor-forming ability may be cytoplasmically transmitted in the hamster cybrids.
 ...
PMID:Tumorigenicity and its suppression in cybrids of mouse and Chinese hamster cell lines. 27 80

When horse-radish peroxidase (HPO) was administered iv to Vx2 carcinoma-bearing rabbits, an HPO reaction product was detected in the lumina of blood vessels and the extracellular spaces between tumor cells in the first few minutes after administration. HPO was also seen in vesicles in tumor cells. Fifteen minutes to 1 hour after administration, the HPO reaction product was found mainly in the large membrane-bound vacuoles. Within 6--12 hours, the HPO activity gradually diminished in large membrane-bound vacuoles (lysosomes). In conclusion, exogenous HPO was rapidly incorporated into Vx2 carcinoma cells by pinocytosis, and then pinocytotic vesicles were fused with lysosomes.
 ...
PMID:Cytochemical study on uptake of exogenous peroxidase by Vx2 carcinoma cells transplanted into the rabbit. 28 Jul 9

Thymidine kinase-deficient OTT6050 mouse teratocarcinoma cells were fused with hypoxanthine phosphoribosyltransferase-deficient Fu5AH rat hepatoma cells by means of inactivated Sendai virus. The resulting hybrid cells, which were selected in hypoxanthine/aminopterin/thymidine medium, retained almost all of the mouse chromosomes and various numbers of rat chromosomes, and showed many chromosomal rearrangements. The hybrid cells, as well as both parental lines, formed tumors after subcutaneous injection into athymic nude mice. Single rat--mouse hybrid cells from a clonally established subline were transplanted into C57BL6/J mouse blastocysts carrying many genetic markers suitable for the detection of hybrid cell-derived tissue contributions. From 144 blastocysts, each of which was injected with a hybrid cell and then surgically transferred to the uterus of a pseudopregnant foster mother, 62 adult mice developed without any visible coat mosaicism. However, three of these mice showed internal hybrid-cell participation in their livers and a limited number of organs of endomesodermal origin. A tumor classifiable as hemangio endothelioma was found in the liver, the only mosaic tissue, of one of the chimeric mice. Nine different rat-specific enzyme variants were detected in the mosaic organs. A considerable number of variations concerning the presence and quantitative activity of the foreign gene products probably resulted from chromosomal segregation, tissue-specific gene activity, or dosage compensation during differentiation in vivo. Our results demonstrate that cultured malignant rat--mouse hybrid cells differentiate normally and become functionally integrated during development. The appearacne in vivo of certain rat-specific gene products that are not found in the hybrid cells under conditions in vitro indicates differential gene expression of the introduced xenogeneic chromosomes.
 ...
PMID:Xenogeneic gene expression in chimeric mice derived from rat--mouse hybrid cells. 28 11


1 2 3 4 5 6 7 8 9 10 Next >>