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)

Tumor incidence was studied in 1,2-dimethylhydrazine (DMH) injected male rats assigned at weaning to isoenergetic casein-sucorse deits containing 7.5%, 15%, or 22.5% protein with or without 2.5% urea. Twenty rats fed each diet were given weekly intraperitoneal injections of DMH (15 mg/kg body weight/week) for the first 24 weeks and 20 were given saline. Of 96 DMH-injected rats necropsied after 28 weeks, 88 were necropsied during the 32nd or final week of the experiment. Adenocarcinomas of the small and large intestine were larger and significantly more numberous in rats fed 15% and 22.5% dietary protein. Keratin producing papillomas of the sebaceous glands of the external ear were observed first at 21 weeks in DMH-injected rats fed 22.5% protein. These were subsequently observed in some rats from all DMH-treated groups. As time progressed, the ear tumors increased in size and number in all groups but the greatest incidence was in the group fed 22.5% protein. No tumors were observed in saline-injected rats. Urea feeding did not increase the number of tumors nor cause changes in pH, urease activity or ammonia concentration of contents of the colon or cecum, or blood cholesterol. As dietary protein increased, cecal ammonia concentrations rose while both colon and cecal pH dropped. Portal blood urea and cholesterol reose as dietary protein was increased. DMH-treated rats had significantly higher concentrations of colon and cecal ammonia and lower blood cholesterol. Altough the rats fed 7.5% protein gained significantly less weight during 0 to 6 weeks of feeding, their weight gain was significantly higher during 6 to 26 weeks. No tumors were found in rats necropsied at 16 weeks.
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PMID:Nitrogen intake and tumorigenesis in rats injected with 1,2-dimethylhydrazine. 1 Mar 59

The structure and antigenic characteristics of a human k, IgG myeloma protein that formed half-molecules were analyzed. Most of the myeloma protein found in the patient's serum and urine consisted to two chain 4.3S half-molecules. A small amount of four chain 7S myeloma protein was, however, found in the serum and was apparently formed by the same clone of tumor cells. Polyacrylamide gel electrophoresis in 8 M urea and 1% sodium dodecyl sulfate and analytical ultracentrifugation in 6 M guanidine of the fully reduced and alkylated half-molecule indicated that this myeloma protein had a heavy chain of a smaller molecular weight (approximately 45,000) than that of normal gamma chains, Except for this apparent deletion, the heavy chain resembled gamma1 chains. The amino acid composition of the peptides containing the half-cysteine residues forming the interchain disulfide bonds, the glycopeptide of the Fc fragment and the COOH-terminal structure were similar if not identical with the analogous structures of gamma1 chains. No Fc fragment could be prepared because the Fc portion of the heavy chain of the myeloma protein was extremely susceptible to degradation with papain. After mild reduction and alkylation, the 7S myeloma protein dissociated into half-molecules, indicating a lack of noncovalent interactions in the Fc fragment that are present in all classes of human immunoglogulins and are responsible for the formation ofFc dimers. The half-molecule was antigenically deficient in the Fc fragment. It failed to precipitate with anti-Fc fragment antisera in double gel diffusion tests and inhibited a Fc-anti-Fc fragment binding reaction weakly and incompletely. The half-molecule and the 7S protein had the same genetic markers on the first and second homology region of the gamma chain. The half-molecule lacked, however, the corresponding markers on the third homology region, These findings suggest that this myeloma protein had a deletion in the gamma chain which was probably located in third homology region and was likely the structural abnormality responsible for the lack of noncovalent interaction in the Fc fragment and absence of most of the antigenic determinants characteristic of gamma chains.
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PMID:Human myeloma IgG half-molecules. Structural and antigenic analyses,. 5 83

Seventeen patients with various histologic types of incurable malignant disease were treated with a combination of vinblastine, bleomycin, and cis-dichlorodiammineplatinum(II). Creatinine and blood urea nitrogen elevations were noted but were not of a severe degree. White blood cell and platelet count depressions were seen and appeared to be cumulative, though not life-threatening. Tinnitus and high-frequency hearing loss were noted. Tumor regression was seen in one patient with adenocarcinoma of the lung and in one patient with a testicular tumor. This appears to be a manageable drug combination with frequent monitoring of renal, hematopoietic, pulmonary, and auditory function. A phase II study establishing the therapeutic efficacy of this combination in advanced testicular neoplasms now appears to be indicated.
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PMID:Phase I clinical trial of combined therapy with vinblastine (NSC-49842), bleomycin (NSC-125066), and cisdichlorodiammineplatinum(II)( NSC-119875). 6 32

In a previous study, we demonstrated three variants of human alphafetoprotein by crossed immunoelectrophoresis. In addition, we correlated the capacity of alpha-fetoprotein isolates from various hepatoma and fetal sources to suppress human lymphocyte transformation in vitro with the relative proportion of the electronegative variant, HAFP-3, present in each isolate. We have now isolated alpha-fetoprotein from the serum, ascitic fluid, and saline extract of tumor from a single hepatoma patient and from a homogenate of fetal livers. When tested for their capacity to inhibit human lymphocyte transformation in vitro, tumor and fetal liver alphafetoprotein were found to be extremely potent, serum alphafetoprotein had intermediate potency, and ascitic fluid alpha-fetoprotein was the least potent. Analysis of these isolates by crossed immunoelectrophoresis confirmed the correlation between the proportion of HAFP-3 and the immunosuppressive potency of each isolate. In addition, analysis of these isolates by isoelectric focusing in polyacrylamide gels containing 8 M urea revealed further evidence of microheterogeneity; at least six molecular variants were apparent. The proportion of one of these variants, termed HAFP-3a, in each isolate was correlated with the immunosupressive potency of the isolate. The sialic acid content of the various alpha-fetoprotein isolates did not vary significantly. Our data suggest that a postsynthetic modification of alphafetoprotein occurs, probably after secretion, which reduces immunosuppressive potency by converting the active electronegative species to an inactive electropositive form. This modification probably involves a charged moiety other than sialic acid on the molecule.
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PMID:A postsynthetic modification of human alpha-fetoprotein controls its immunosuppressive potency. 7 37

Purified human alpha-fetoprotein (HAFP) from five patients with hepatoma, one with gastric carcinoma, one with an embryonal cell tumor, and from fetal liver has demonstrated immunosuppressive potencies in vitro which vary over three orders of magnitude. A reversible association of HAFP with the cell surface and a predominant effect on T cells are suggested. No evidence of complex formation between HAFP and mitogen has been found. The microheterogeneity of HAFP has been detailed with crossed immunoelectrophoresis and isoelectric focusing in polyacrylamide gels containing 8M urea, and the immunosuppressive potency of HAFP isolated from a given source can be correlated with the proportion of certain HAFP species contained in it.
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PMID:Human alpha-fetoprotein: immunosuppressive activity and microheterogeneity. 7 48

We describe a rapid and very sensitive method for detecting proteins as antigens after their separation in polyacrylamide/agarose composite gels, with or without sodium dodecyl sulfate. The polyacrylamide matrix is crosslinked with a reagent that can be cleaved with periodate or alkali to facilitate transfer of the protein bands to diazobenzyloxymethyl-paper, where they are coupled covalently. Specific proteins are detected by autoradiography after sequential incubation with unfractionated, unlabeled specific antiserum and 125I-labeled protein A from Staphylococcus aureus. Antibody and protein A can be removed with urea and 2-mercaptoethanol, and the same paper can be probed again with a different antiserum. An antiserum specific for the simian virus 40 virion proteins VP3 and VP2 has been prepared; it does not crossreact with VP1, as demonstrated by this method. An antiserum raised in rabbits against simian virus 40-transformed rabbit kidney cells is shown to be directed primarily against a periodate-sensitive moiety present in tumor (T) antigen from infected or transformed cells, whereas an antiserum raised in rabbits against large T antigen purified from lytically infected monkey kidney cells by electrophoresis in the presence of sodium dodecyl sulfate [Lane, D.P. & Robbins, A.K. (1978) Virology 87, 182-193] is directed primarily against determinants that are not sensitive to periodate.
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PMID:Transfer of proteins from gels to diazobenzyloxymethyl-paper and detection with antisera: a method for studying antibody specificity and antigen structure. 9 Nov 64

Human renin was purified from a juxtaglomerular cell tumor with a high renin content, 24.2 Goldblatt units/mg of protein. The purification procedure comprised three steps: gel filtration, DEAE-cellulose chromatography, and preparative isoelectric focusing. Five forms of renin amounting to 5.3 mg of enzyme were obtained with isoelectric points of 4.95, 5.10, 5.35, 5.55, and 5.70. They were all glycoproteins. The three major fractions had very similar specific activities, 868, 860, and 809 Goldblatt units/mg of protein. These fractions produced a single band on analytical isoelectric focusing and a single arc on immunoelectrophoresis. On polyacrylamide gel electrophoresis at pH 7.8, each fraction consisted of two renin bands with the same molecular weight, but different net charges. The molecular weight determined by gel filtration and Fergusson plot analysis on polyacrylamide gel was 38,000 to 42,000. The optimum pH determined on N-acetyltetradecapeptide substrate was 6.5, and the Km was 6.8 x 10(-6) M. These parameters were identical with those for standard human kidney renin. Antibodies raised against tumor renin completely inhibited the activity of both tumor and standard renin. Under dissociating conditions (sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel electrophoresis in the presence of 6 M urea), part of the purified enzyme dissociated into two smaller fragments (Mr = 20,000 and 25,000) containing renin activity.
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PMID:Multiple forms of human renin. Purification and characterization. 10 84

Isozymes of carbamyl phosphate synthetase (CPS), CPS I, a mitochondrial enzyme found exclusively in liver and involved in urea synthesis, and of CPS II, a soluble cytoplasmic enzyme widely distributed in animal tissues, were assayed in rat liver and in a series of rat liver neoplasms ranging widely in growth rate and degree of differentiation. CPS I was absent from fast-growing, poorly differentiated hepatomas, such as the Novikoff hepatoma and Morris hepatomas 3924A and 9098F, but was present in slow-growing, well- and highly differentiated Morris hepatomas. However, there was no close correlation between the growth rate or degree of differentiation and the CPS I activity. Activity was very high, at levels comparable with normal liver at about 9 UNITS/G, IN SLOW-GROWING, HEPATOMAS 21, 47C, and 28A but was very low in other slow-growing highly differentiated hepatomas 9618A, 66, and 16. CPS II activity was present in normal liver and all hepatomas examined, but with very low activity, of the order of 1% or less of that of CPS I activity, with maximal values at 5 to 70 milliunits/g. Again, there was no clear correlation with growth rate; the activity was lowest in fast-growing, poorly differentiated hepatomas. A striking observation was a marked lowering of CPS I activity in livers of rats bearing large, slow-growing tumors that have high CPS I activity. As the tumors grew larger and the liver CPS I decreased, a relatively constant total CPS I activity was maintained, suggesting the existence of a homeostatic mechanism. The effect was not observed in rats bearing either fast-growing hepatomas or slow-growing hepatomas with low CPS I activity and was not due to some specific nutritional effects of the tumor on the host.
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PMID:Carbamyl phosphate synthetases in rat liver neoplasms. 16 60

The predominant component of immunoreactive ACTH in the plasma of adrenalectomized normal mice and of mice bearing the adrenotropic mouse pituitary tumor, AtT-20, and in extracts of the normal mouse pituitary and pituitary tumor, has an elution volume on Sephadex G-50 gel filtration approximately midway between the void volume and the elution volume of human ACTH (1-39 peptide). The tumor extracts are shown to contain, in addition to this intermediate ACTH, 2 other components of immunoreactive ACTH, one which coelutes with 131I-labeled albumin (big ACTH) and the other with [125I]hACTH (little ACTH). Big and intermediate ACTH are urea-stable. Controlled tryptic digestion of mouse-tumor big ACTH results within 10 seconds in conversion to an intermediate component followed by continued loss of immunoreactivity. Under the same conditions of tryptic digestion of intermediate ACTH, there is only continuous loss of immuno-reactivity with no change of hormonal form. These findings strengthen the hypothesis that mouse intermediate ACTH is not a precursor for little ACTH.
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PMID:Characterization of mouse ACTH in plasma and in extracts of pituitary and of adrenotropic pituitary tumor. 17 Nov 53

For the first time results of investigations on rats with radioactive compounds in autochtonal tumors of the central nervous system, induced via placenta by Ethyl-Nitrose-Urea (ENU), are reported. In contrast to transplantation tumors the tumors induced by ENU are comparable in regard to the szintigrafic results with human brain tumors. The radiopharmaceuticals 131I-HSA, 99mTc-Pertechnetate, 203Hg-Chlormerodrin and 113m/111In-DTPA are similar to human brain tumors taken up by the ENU-tumors. For these findings it may be important, that the ENU-tumors are of neurogenic origin and do not differ histologically from the human brain tumors. The accumulation of the radioactive substances in ENU-tumors can be explained with the lesion at the blood-brain-barrier and at the blood-nerv-barrier. Therefore, it is discussed that the mechanism of the uptake is similar in human brain neoplasms and in ENU-tumors of the brain. The ENU-tumor model is suitable for testing new radiopharmaceuticals before their application in men.
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PMID:[Experimental investigations on the accumulation of radioactive compounds in autochtonal tumors in the rat (author's transl)]. 17 56


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