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

A transplantable methylcholanthrene-induced fibrosarcoma of female BALB/c mice (the MC-2 fibrosarcoma) was dissociated by combined mechanical and enzymatic means, then fractionated by isopycnic centrifugation in linear albumin gradients. In some experiments recovered cells were both cultured in soft nutrietn agar and inoculated subcutaneously into syngeneic recipients. In these experiments a highly significant correlation was observed between subsequtnt colony number and rapid growth phase tumor size suggesting identity of clonigenic and tumorigenic cells. It was consistently found that clonigenic cells were markedly depleted from the low density extremes of the cell density distribution profiles suggesting that the low density neoplastic cells had irreversibly left the growth fraction. With increasing tumor age, sequential studies showed that both total and clonigenic cell density distribution profiles were variable, showing no obvious trend, suggesting that in the age (13-35 days) and size (2-8 g) range studied growth fraction changes had little selective effect on cells of any specific density. These results imply that a marked selective depletion of low density clonigenic cells (or selective accumulation of low density non-proliferative cells) must mainly occur during an earlier phase of tumor growth. Studies on several other murine solid tumors also showed maximal depletion of clonigenic cells from the least dense fractions, suggesting that this situation may be common.
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PMID:Studies on a fractionated murine fibrosarcoma: proliferative potential of the separated cells. 45 89

Different forms of cell-mediated cytotoxicity were suppressed in the presence of trypan blue. The systems affected included lysis of antibody-coated tumor cells by normal and C. parvum-stimulated mouse peritoneal cells and lysis of allogeneic targets by immune effector cells. The inhibition, measured in a 4-hr 51Cr release assay, was reversible and did not occur in the presence of 30% fetal calf serum or albumin. Binding between effector and target cells through Fc receptors was not affected, and lysis of allogeneic cells was inhibited at the lytic step rather than at the binding step. In contrast, lysis of sensitized erythrocytes was not inhibited by trypan blue, suggesting that lysis of these targets may not involve the steps required in tumor cell lysis. Trypan blue blocked the function of antibody before binding to target cells and also suppressed complement-induced cytolysis. Most individual complement components were susceptible to the inhibitory action of trypan blue. These results reveal an affinity of trypan blue for proteins in general that may be responsible for many of its biologic actions.
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PMID:Suppression of cell-mediated tumor cell lysis and complement-induced cytotoxicity by trypan blue. 46 50

Previous work in our laboratory has indicated that free fatty acids stimulate synthesis of fibrinogen by the liver. The effect of the hypolipidemic agent clofibrate on hyperfibrinogenemia associated with tumors was evaluated by monitoring clofibrate-induced changes in plasma fibrinogen concentration and biosynthesis of the protein in Buffalo rats implanted with a localized, nonmetastasizing neoplasm derived from a tumorigenic hepatoma cell line (HTC4). In tumor-bearing animals not treated with clofibrate, cancer growth was associated with elevated rates of fibrinogen synthesis and a doubling of plasma fibrinogen concentrations. Plasma free fatty acid concentrations and serum free fatty acid/albumin molar ratios were also increased in tumor-bearing rats. Treatment with clofibrate in doses which normalized the plasma free fatty acid/albumin ratio also prevented the tumor-associated rise in plasma fibrinogen. Rates of fibrinogen synthesis were lowered significantly in clofibrate-treated animals. Tumor growth was not affected by clofibrate. These results indicate that hyperfibrinogenemia associated with nonmetastasizing tumors may reflect changes in lipid metabolism which are neutralized by clofibrate. Thus, treatment with clofibrate or other hypolipidemic agents should be evaluated in cancer patients with elevated plasma fibrinogen levels and their attendant complications.
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PMID:Suppression of tumor-associated hyperfibrinogenemia and free fatty acidemia with p-phenoxybenzalbutyrate (clofibrate). 47 20

Assay conditions which, if varied, may affect the performance of the dextran-coated charcoal assay for estradiol receptor in breast cancer specimens, are reviewed. Incubation time and temperature influence the rate of binding and receptor stability. Lower temperatures preserve receptor integrity, so 2 hours of incubation at 4 degrees were chosen as standard. Various reducing agents (thiols) were tested for their effects on supernatants from high-speed centrifugations, and the following optimum levels were established: dithriothreitol, 7.5 mM for MCF cell line homogenates; and 1 mM for human breast tumor homogenates. Duration of dextran-coated charcoal extraction of the cytosol-tritiated estradiol incubation had no effect on receptor level up to 21 hours. Minimum levels of nonspecific binding could be seen by 4 hours. To overcome artifactual nonspecific binding by the charcoal, albumin is recommended as a supplement to the incubation (200 mcg or more). The dextran:charcoal ratio (1:10 by weight) recommended prevented receptor loss in the order: 1:1 1:10 1:100. 1 mg of dextran-coated charcoal (1:10) has the capacity to absorb .3-.4 mg of free estradiol. Diethylstilbestrol was as efficient as estradiol at displacing unlabeled competitors, but U11, 100A, and estrone were inefficient competitors.
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PMID:Characteristics of the dextran-coated charcoal assay for estradiol receptor in breast cancer preparations. 50 Dec 5

Quantitation of the concentration of immunoproteins in serum, and cystic fluids from six patients (three with cerebral astrocytoma and three with cerebellar hemangioblastoma) has been determined. The values for total protein, albumin, immunoproteins IgG, IgA, and IgM, and C3C (complement) in cyst fluid more closely correspond to serum than to cerebrospinal fluid values. Values for cyst fluid, cerebrospinal fluid, and serum were determined using albumin ratios in order to compare relative differences between fluids from these three compartments. Our data suggests that: 1) the major protein content of brain tumor cyst fluid is consequential to a transudative process from serum, and 2) that immunoglobulins IgG and IgA are present in higher concentrations in human brain tumor cyst fluids in comparison to IgM concentrations. These studies further question the concept of the brain as an "immunological privileged site", and may be of direct relevance to the investigation of the use of immunotherapeutic modalities as an adjunct after surgical tumor removal.
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PMID:Immunoproteins in human brain tumor cyst fluids. 55 78

Results of previous studies have shown that the VX2 carcinoma in rabbits synthesizes large amounts of prostaglandin E2 (PGE2). PGE2 secreted by the tumor is rapidly metabolized and can be measured in plasma as the metabolite 13,14-dihydro-15-keto-PGE2 (PGE2-M). We have previously proposed that the hypercalcemia that occurs in rabbits bearing the VX2 carcinoma is due to excessive secretion of PGE2 by the tumor and its subsequent action on the skeleton as a bone resorption-stimulating factor. In the course of these studies, we noted that the plasma of rabbits bearing the VS2 carcinoma became blue about 1 wk after tumor implantation. The intensity of the color increased markedly thereafter. We therefore measured ceruloplasmin in plasma by both chemical and immunological assay methods. Plasma ceruloplasmin and PGE2-M rose in parallel (within 7-10 days) and preceded by 7-10 days the development of hypercalcemia. 2 wk after tumor implantation, plasma PGE2-M and ceruloplasmin had risen about 20- and 6-fold, respectively, while the rise in plasma calcium was just beginning. Indomethacin, an inhibitor of prostaglandin synthesis, given from the time of tumor implantation prevented completely the hypercalcemia and largely inhibited the rise in ceruloplasmin. When given after hyperprostaglandinemia had developed, indomethacin produced a fall in both PGE2-M and ceruloplasmin. A rise in plasma haptoglobin concentrations similar to that seen for ceruloplasmin was also observed. No changes in plasma albumin concentrations occurred. We conclude that the acute phase reactants ceruloplasmin and haptoglobin rise rapidly in the plasma of rabbits bearing the VX2 carcinoma, and that this increase is related to arachidonic acid metabolism in these animals. It is possible that arachidonic acid metabolites also play a role in the elevations of these two plasma proteins observed in certain patients with malignant tumors.
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PMID:Acute phase reactants ceruloplasmin and haptoglobin and their relationship to plasma prostaglandins in rabbits bearing the VS2 carcinoma. 65 Jan 52

We evaluated assays of Tissue Polypeptide Antigen in serum and urine, as an index to the presence of cancer. In the assay, serum, which is first absorbed with human albumin-labeled sheep erythrocytes, or untreated urine (diluted with an equal volume of TPA-free serum) is incubated with antibody specific to Tissue Polypeptide Antigen and then reacted with sheep erythrocytes labeled with Tissue Polypeptide Antigen. We found an increased concentration of Tissue Polypeptide Antigen in the serum of 378 of 513 (74%) and in the urine of 49 of 77 (64%) patients with cancer, as compared with 40/112 (36%) and 7/29 (24%), respectively, for individuals with benign neoplasms. Normal individuals were defined as those with less than 0.09 unit of the antigen per milliliter of specimen. Concentrations exceeding this were found in 2/67 (3%) sera and 6/56 (11%) urines from supposedly normal persons. Tissue Polypeptide Antigen was found in above-normal concentrations in patients with cancer, regardless of neoplasm type and extension, with a higher proportion of abnormal values in patients with distal metastases.
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PMID:A preliminary evaluation of tissue polypeptide antigen in serum or urine (or both) of patients with cancer or benign neoplasms. 65 73

The disappearance rate (k) of i.v. glucose was measured in cachectic and non-cachectic cancer patients and tumour-free controls. The respective k values were found to be 1.06 +/- 0.27 (mean +/- s.d.), 1.64 +/- 0.34 and 1.63 +/- 0.23. Of the other parameters measured, only plasma albumin level was found to vary significantly amongst the 3 categories, the mean level being the lowest in cachectic cancer patients. The means of total plasma protein, fasting blood glucose and plasma liver enzyme concentrations were similar in the 3 groups. Glucagon, a potent insulin secretogogue, failed to augment the fasting insulin level in cachectic but did so in non-cachectic cancer patients. Taken together, the findings suggest that the reduced glucose tolerance in patients with neoplasia is due to impairment of insulin release exhibited predominantly by ill-nourished advanced cancer patients having a moderate to sever degree of hypoalbuminemia.
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PMID:Mechanism of impaired glucose tolerance in patients with neoplasia. 69 44

Heat-induced inhibition of erythrocyte sedimentation (HIES) was examined in 158 cases. HIES is significantly lower in patients with a liver cell damage isolated or due to metastases of a neoplastic process in comparison to that in patients suffering from inflammation or malign tumor not involving the liver. Generally, HIES depends upon the concentration of lysophosphatidyl choline (lysolecithin) which is set free in plasma by lecithin-cholesterol-acyltransferase (LCAT) during incubation. In patients with lever cell damage, LCAT is diminished. HIES is being influenced by several factors: Lysophosphatidyl choline is bound to albumin, and this prevents its reaction on the erythrocyte surface. Lysophospholipase reduces the concentration of lysophosphatidyl choline in the plasma by splitting off its fatty acid in the alpha-position. Specific serum proteins, the so-called agglomerines, which are responsible for the acceleration of erythrocyte sedimentation, are counteracting the HIES. The concentration of albumin and agglomerines in plasma and the activity of lysophospholipase are subject to physiologically and pathologically caused deviations. Thereby, HIES is being influenced individually at varying degrees. This makes it difficult to estimate the LCAT activity which represents the principal cause of HIES. As a consequence, HIES seems not to be suitable for clinical diagnostics.
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PMID:[Diagnostic significance of heat-induced inhibition of erythrocyte sedimentation (author's transl)]. 71 17

To evaluate the biological tolerance of the human liver to prolonged warm ischemia, two groups of extensive hepatic resection for tumor were compared. Group 1 (11 patients) performed with short hepatic inflow occlusion (7 [mean] +/- 2 [SEM] minutes), and group 2 (nine patients) operated with use of complete hepatic vascular exclusion and prolonged warm liver ischemia (38 [mean] +/- 5 [SEM] minutes). Comparison of biological values, such as transaminase, bilirubin, total protein, albumin, and fibrinogen levels, the platelet count, prothrombin complex, and proaccelerin level, did not show statistically significant differences between the two groups. Therefore, the hepatic warm ischemia period may be, if needed, safely extended beyond the classical 15 minutes. It lasted 65 minutes in one case without adverse effect. These clinical observations parallel recent experimental work and should destroy the myth of the high sensitivity of the liver to warm ischemia.
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PMID:Tolerance of the human liver to prolonged normothermic ischemia. A biological study of 20 patients submitted to extensive hepatectomy. 73 77


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