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

Graphs and tables are shown describing the growth especially the depth of the ice-ball in tissue during freezing with round flow and massive probes (2-20 mm diameter). Thus prior to clinical application of cryosurgery the probe diameter and the time of freezing can be estimated corresponding to the size of the tumor. Results are presented for temperatures of the cooling fluid of -196 degrees C (liquid nitrogen) and -80 degrees C.
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PMID:[Graphs on the growth of the ice-ball using round cryoprobes at -80 degrees C and -196 degrees C (author's transl)]. 14 Sep 61

Glucagon activated adenylate cyclase in a homogenate of a pheochromocytoma over the concentration range 1 times 10 minus 8M to 1 times 10 minus 6M. Several other hormones including adrenocorticotropin, thyrotropin, parathyroid hormone and histamine were without effect. The tumor glucagon receptor was characterized and found to be similar in several ways to the glucagon receptor previously reported in normal tissue such as liver and heart. One, the receptor specifically bound 125-I-glucagon. Two, solubilization of the pheochromocytoma abolished glucagon-activation of the adenylate cyclase. Three, glucagon-responsiveness of the adenylate cyclase was partially restored by the addition of phosphatidylserine to the incubations. One major difference was observed between the glucagon receptor in tumor tissue and that in liver and heart, namely, a marked lability in 125-I-glucagon binding and adenylate cyclase activity. Within four days, despite storage in liquid nitrogen, 75% of the binding activity and all of the adenylate cyclase activity in the solubilized preparation were lost. The factor(s) responsible for this lability remains unidentified.
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PMID:Characterization of the glucagon receptor in a pheochromocytoma. 16 16

The hypothesis that selective action of cyclophosphamide, compared to other nitrogen mustards, is due to a balance between enzymatic formation of inactive metabolites and chemical formation of the alkylating product was studied in view of previous observation in our laboratory. Metabolite analysis, inhibition of growth of tumor cells in culture, and kinetic analysis of relevant enzyme activities were used in this investigation. The effect of tissue-soluble enzyme fractions on biochemically prepared aldophosphamide, aldophosphamide analogs, and phosphoramide mustard showed: (a) a range of deactivation abilities with aldophosphamide (liver greater than kidney greater than intestinal mucosa greater than tumor greater than spleen = bovine serum albumin solution); (b) the formation of different amounts of carboxyphosphamide from aldophosphamide; and (c) only comparatively small reductions in the toxicity of phosphoramide mustard and of 4-hydroxy-4methylcyclophosphamide. Correlations were found between NAD+-dependent aldehyde dehydrogenase activity and the deactivation ability of tissue-soluble enzyme fractions. Blockage (by C4 substitution) or inhibition (by disulfiram) of secondary oxidation of aldophosphamide, mediated by aldehyde dehydrogenase, resulted in diminished deactivation ability in vitro and reduced selectivity in vivo.
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PMID:Studies on the selective action of cyclophosphamide (NSC-26271): Inactivation of the hydroxylated metabolite by tissue-soluble enzymes. 17 12

Nitrogen-13 labeled L-glutamic acid was evaluated as an imaging agent for tumors involving bone. The enzymatically prepared labeled compound was administered intravenously to dogs with spontaneous tumors, and tumor uptake was determined with a gamma camera and rectilinear scanner. These tumors were well visualized with 13N-glutamic acid, and the results compared favorably with uptake studies performed on the same animals with 99mTc-diphosphonate.
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PMID:Imaging of tumors involving bone with 13N-glutamic acid. 18 83

Attempts to design an agent which would release cytotoxic nitrogen mustards within collagenase-producing tumors led to the synthesis of Cbz-L-Pro-L-Leu-Gly-L-Pro-Gly-NHC6H4N(CH2CH2Cl)2 (10). 10 was cleaved in vitro by bacterial and tumor-associated collagenase as expected at the peptide bond joining L-leucine and glycine to give Gly-L-Pro-Gly-NHC6H4N(CH2CH2Cl)2 which was over six times more toxic, on a molar basis, than 10. In vivo tests of 10 against well-advanced Sarcoma-180 gave disappointing results. The lack of specific antitumor activity may be accounted for by the presence of competing cleavage reactions by collagenases in certain normal tissues.
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PMID:Collagenase-sensitive peptidyl-nitrogen mustards as potential antitumor agents. 21 58

The cytotoxic action of certain antitumor agents is potentiated by centrophenoxine although centrophenoxine itself is not an antitumor agent. Previous investigations have suggested that centrophenoxine might potentiate the cytotoxicity produced by antitumor drugs that alkylate, and other modalities that damage, DNA, but that it would not potentiate the cytotoxicity produced by antitumor drugs that inflict cellular damage in other ways. To test this hypothesis, the antitumor effects of X-irradiation UV-irradiation, alkylating agents and antitumor drugs that are not ordinarily considered to be alkylating agents were determined in the presence and absence of centrophenoxine. Mouse P388 lymphoma cells growing in static suspension culture were used as the experimental tumor. The cytotoxic action of most alkylating agents was found to be potentiated by centrophenoxine; Included in this group were several difunctional nitrogen mustards, two ethylenimines, a nitrosourea and mitomycin C. Greatest enhancement, 7-fold, was of chlorambucil antitumor activity. Centrophenoxine did not potentiate the lethality of X- or UV-irradiation or the cytotoxicity of several antineoplastic drugs that are not alkylating agents.
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PMID:Potentiation of antitumor drug action by centrophenoxine: specificity. 32 65

Studies on volunteers have shown that the gas hypoxic mixture containing 10% of oxygen and 90% of nitrogen (GHM-10) renders a protective action on the genetic apparatus of human skin cells but provides no protection of the peripheral blood leucocytes, which show the identical character of metabolic processes as neoplastic cells. Under clinically performed distant x-ray therapy for breast cancer the inhaling of GHM-10 was found to render the antiradiation protective action on different normal tissues (skin, subcellular connective tissue, muscle tissue, mammary gland tissue), but it fails to protect the tumor tissue and regional lymph nodes involved. The clinical observations were supported by pathomorphological examination of the operation material.
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PMID:[Radiation protection using a gaseous hypoxic mixture in oncological practice]. 38 Jan 57

Peripheral blood lymphocytes (PBL) from normal human donors were sensitized in vitro against allogeneic human acute myelocytic leukemia (AML) cells by means of an unidirectional mixed lymphocyte-tumor cell culture (MLTC) technique. The cytotoxic responsiveness of the sensitized lymphocytes, as determined in vitro by the 51Cr-release assay, varied among individual lymphocyte donors and was greatly dependent on the sensitization culture conditions. Induction of cytotoxic effector cells was augmented appreciably by adding to the cultures minute amounts of the immunopotentiating agent MER-BCG. Responding lymphocytes and stimulating leukemia cells cryopreserved for several weeks in liquid nitrogen were as effective as fresh cells in generating effector lymphocytes; the cytotoxic capacity of already sensitized lymphocytes was fully retained by cryopreservation. The implications of these findings for possible clinical employment of in vitro sensitized lymphocytes in adoptive immunotherapy of cancer are discussed.
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PMID:In vitro induction of cytotoxic effector cells against human neoplasms. I. Sensitization conditions and effect of cryopreservation on the induction and expression of cytotoxic responses to allogeneic leukemia cells. 38 44

There are many factors which are responsible for the high incidence of cachexia in human neoplasia. In this review, those considered to be of major importance are discussed. Nutritional disturbances, such as anorexia and malabsorption, are common and nutritional repletion may be beneficial to certain patients. Raised metabolic rate and energy expenditure are also encountered. Tumour cells may act as a nitrogen trap or energy sink, but the significance of these mechanisms in man is questionable. Ectopic hormone production by tumours is well established and a number of tumour-derived substances have been described which interfere with the intermediary metabolism of the host. The significance of these various substances also remains uncertain. Most experimental studies of cancer cachexia have utilized transplantable animal tumour models which bear a poor resemblance to the clinical condition. Development of more suitable models with human tumour xenografts might allow a quicker and better understanding of the aetiologies of human cancer-induced cachexia.
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PMID:Cancer cachexia in man: a review. 39 80

The tumor-inhibitory effect of an intralesional injection of Propionibacterium acnes was of limited duration ("finite"). Our model was the DBA/2 syngeneic mouse injected with P815 mastocytoma cells (5 X 10(5)) into each rear footpad; only the left was treated, leaving the right as a "pseudometastasis." The finite effect occurred at approximately 21 days after the first treatment. Subsequent i.p. treatments with P. acnes did not alter this effect, although they increased mean survival time. With one footpad tumor, we achieved 22% cures with complete regression and no sign of metastatic growth. A RNA fraction from P. acnes produced inhibition of tumor growth, but crude cell walls and cell walls treated with Pronase had no effect. A P. acnes cytoplasmic fraction with tumor-inhibitory activity was pelleted by high-speed centrifugation; this fraction inhibited P815 mastocytoma as fully as whole cells injected in one-fifth the dose on a nitrogen basis and did not cause a local inflammatory reaction. The activity of the pellet also differed from whole cells in that it was equally inhibitory to the pseudometastasis in the contralateral right rear footpad. The cytoplasmic fraction apparently contained at least two active components since activity was obtained at two dilution levels. Such activity was relatively stable at 5 degrees, but it was unstable at -30 degrees.
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PMID:Antitumor activity of Propionibacterium acnes (Corynebacterium parvum) and isolated cytoplasmic fractions. 40 91


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