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

Macrophage precursor cells were cultured from the bone marrow of mice in a liquid culture system in the presence of conditioned medium. To separate their different maturation stages, they were passed through a discontinuous Ficoll density gradient, treated with iron plus magnet or passed through glass bead columns. The different maturation stages have been tested for their function in antibody-dependent cellular cytotoxicity (ADCC) against tumor target cells and in lymphokine-induced macrophage-mediated cytotoxicity. It is shown that the promonocyte, a nonadherent, nonphagocytic precursor cell, is a highly potent cytotoxic effector cell against antibody-coated tumor targets but is totally inactive as an effector cell in lymphokine-induced macrophage-mediated cytotoxicity. In contrast, in the lymphokine-induced macrophage-mediated cytotoxicity the cytotoxic effector cell is a mature macrophage. Thus, ADCC seems to be a function of the macrophage precursor promonocytes, whereas lymphokine-induced cytotoxicity is performed by mature macrophages. The relationship of promonocytes and killer (k) cells in ADCC against tumor targets is discussed.
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PMID:Antibody-dependent cellular cytotoxicity against tumor cells. II. The promonocyte identified as effector cell. 46 90

This report compares the sensitivity of 17 tumor cell lines to cytolysis mediated by natural killer (NK) cells or by activated, bone marrow-derived macrophages (AM) from 15 inbred mouse strains. Some tumor cell lines, notably P815, were highly sensitive to AM-mediated lysis but almost completely insensitive to NK cells, whereas other cell lines were lysed by NK cells but not AM. In a genotype survey, some low-responder strains in the NK system, such as A/Sn, were high responders in the AM system, and conversely, one intermediate to high-responder strain (C3H/HeJ) in the NK system was a low responder in AM-mediated cytolysis. In addition, macrophage cytotoxicity factor was necessary to activate macrophages, but this lymphokine did not augment NK activity. Furthermore, the NK population did not contain pre-activated macrophages since pre-activated cells were removed on glass bead columns or by iron carbonyl and a magnet; treatments which have been previously shown not to affect NK cells. These results suggest that NK cells are distinct from AM in physical characteristics, target selectivity, genotype distribution and the mechanism of cytolysis.
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PMID:A functional comparison of tumor cell killing by activated macrophages and natural killer cells. 46 92

A single intraperitoneal dose of methyl(acetoxymethyl)nitrosamine (13 mg/kg body weight) given to 78 5-week-old male rats induced 25 mesotheliomas; two mesotheliomas were found in 67 control rats. All mesotheliomas arose from the peritesticular mesothelium and had a typical microscopic appearance of branching papillary fronds with a collagenous core covered by one or many layers of plump tumor cells. Cytoplasm of tumor cells contained material that reacted positively to a colloidal iron stain and was labile to hyaluronidase. In addition to frank mesotheliomas, 16 lesions, which we called atypical mesothelial proliferations, were found. These consisted of a single focus of plump mesothelial cells overlying an area of thick stroma. Often these foci included short, non-branched papillary projections above the surface of adjacent normal mesothelium. Twelve of the 16 lesions occurred in methyl(acetoxymethyl)nitrosamine-treated rats.
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PMID:Mesotheliomas and proliferative lesions of the testicular mesothelium produced in Fischer, Sprague-Dawley and Buffalo rats by methyl(acetoxymethyl)nitrosamine (DMN-OAc). 47 88

The occupational group composed of the iron-miners working at the bottom of the mines in Lorraine makes up a high risk population for lung cancer (The carcinogenic index is 5 to 12 times as high as that of the population of non-miners). The authors report a new series of 270 cases in support of this assertion. The cancers have few particular characteristics. Their genesis appears to be related with the action of many co-factors: tobacco, various gases and noxious dust, iron particles. Our findings are similar to those of the Swedish, British and Russian authors. The occupation of iron-miner at the bottom of the mine appears then to favorize the manifestation of lung cancer. So it would be fair to consider this tumor an occupational disease, as with asbestosis.
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PMID:[Should the lung cancer of iron-miners in Lorraine be considered an occupational disease? (author's transl)]. 49 83

Iron uptake rate of the tumor tissues of the rat liver was compared with that of the nontumor tissues of the same rat liver. Ferric[59Fe] citrate was injected to rats bearing hepatoma induced by the administration of diethylnitrosamine. The tumor and nontumor tissues were enucleated from the liver and radioactivity (cpm/10 mg tissue) of the individual tissue was calculated to estimate the iron uptake rate of the tissue. Eleven rats were finally available for the study. Population mean of radioactivity of the tumor group was larger than that of the nontumor group when examined 6 hr after the injection, so far as the specimens of both groups were sufficient in number, more than 19. The variance of radioactivity of the tumor group was always larger than that of the nontumor group, probably in part due to cytological and histological varieties of the tumor tissues. These results suggest that the tumor tissues can take up more iron than the nontumor tissues.
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PMID:Radio-iron uptake of rat hepatoma. 52 Jul 51

Polymorphous tumor cells with bizarre giant nuclei are characteristic of the so-called atypical meningioma. Some of these cells are iron-positive. Meningioma cells apparently are able to store iron excessively. It is discussed whether an extremely high intracellular iron uptake is responsible for atypical meningioma growth. Derangement of mitotic spindles may lead to polyploid chromosome sets and thereby to giant nuclei. This seems likely because induction of tumor growth after iron injection has been described. Spodographic examinations showed that even histologically inconspicuous tumor cells contain fine-grained iron. Application of the Prussian-blue reaction to spodograms reveals distinctly higher iron contents than common paraffin sections had proved.
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PMID:Iron-induced atypical meningioma cells? 52 62

Tattooing provides accurate localization for tumor surgery following radiation therapy. This paper describes studies done on tattooing technique and instruments available currently. Procedures tested included hypodermic needles and three types of surgical instruments. Chemical tested included india ink, iron oxide, and colored pigments. India ink and iron oxide used with the Spaulding-Rogers Outliner gave satisfactory tattoos.
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PMID:Mucosal tattooing in oral cavity carcinoma. 53 Jun 99

A significant anemia develops in Buffalo rats bearing the Morris hepatoma 7777. By indiceal measurements the red blood cells (RBCs) appear to be microcytic and hypochromic. Ferrokinetic studies demonstrate a decreased uptake of iron in the bone marrow and an increased incorporation of iron in the spleens of the tumor-bearing animals. RBC survival studies indicate the presence of a hemolytic component which appears to contribute to the anemia. The RBCs from tumor-bearing animals (T-RBC) have a greatly increased fragility in sodium chloride solutions. Inspection of these T-RBCs by electron microscopy demonstrates significant echinocytosis when they are compared to normal cells. Electrophoretic separation of the hemoglobin from T-RBCs shows a pattern different from normal cells and consistent with the pattern described for hemoglobin from spleen and bone marrow. The findings are consistent with bone marrow inadequacy and an increased splenic erythropoiesis which is insufficient to maintain normal hematological values. The hypothesis is presented that the RBCs synthesized under these circumstances appear in the circulation with an "immature" hemoglobin pattern and are hemolyzed more readily. This process then contributes to the hemolytic component and development of the anemia.
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PMID:Host-tumor interactions: basis for the anemia in rats bearing the hepatoma 7777. 53 90

Radiotracer 67Ga-citrate is used as a tumor-seeking agent in clinical imaging investigations although fundamental reasons for its high uptake in certain malignant lesions remain unexplained. The mechanism by which 67Ga becomes concentrated in tumor cells has been investigated by comparing 67Ga and 59Fe uptake by cultured mouse myeloma cells with particular reference to uptake stimulation by transferrin. Concentrations of human transferrin down to 2 microgram/ml greatly stimulated cellular uptake of both tracers, whereas bovine transferrin proved relatively inactive. The rates of stimulated uptake of both tracers were similar as was their high degree of retention by cells, but their quantitative dependencies on transferrin concentration showed characteristic differences. Pretreatment of human transferrin with saturating amounts of nonradioactive Fe3+ canceled its ability to promote 59Fe uptake, but it had little effect on its promotion of 67Ga uptake. Further increase in the amount of added Fe3+ did cause a progressive depression of 67Ga uptake, but this effect probably relates to the iron distribution in the whole-cell culture system including the fetal calf serum component of cell growth medium. The results suggest that 67Ga and 59Fe reveal different aspects of the interaction of transferrin with cells.
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PMID:Transferrin promotion of 67Ga and 59Fe uptake by cultured mouse myeloma cells. 56 54

Apocrine tumors from the axilla of 12 patients were studied clinically and pathologically. Based on histologic features, two tumors were classified as adenomas and ten as adenocarcinomas. All of the neoplasms were characterized by a glandular arrangement of large cells with abundant eosinophillic cytoplasm and evidence of decapitation secretion. The cytoplasm of the tumor cells contained PAS-positive, diastase-resistant granules. Intracytoplasmic particles of iron were demonstrable in three of ten tumors. Follow-up was available for all 12 patients. The two patients with apocrine adenoma are alive and well. Two patients with adenocarcinoma died of unrelated causes shortly after diagnosis. Of the remaining eight patients with adenocarcinoma, three have died of disease, and one is living with skeletal metastasis. A correlation appears to exist between tumor differentiation and prognosis.
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PMID:Apocrine gland adenoma and adenocarcinoma of the axilla. 62 45


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