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)

Properties of aryl hydrocarbon hydroxylase in the microsomes were compared between Morris hepatoma 5123D and the host liver from rats bearing this tumor. Requirement of NADPH for the assay of the enzyme activity was observed, compared to that of NADH, and also the additive effect of NADH on the requirement of NADPH was found in the tumor and liver. Curve of pH optimum of the enzyme activity in tumor and liver differed between the rats treated with corn oil and those with 3-methylcholanthrene, indicating a slight shift of the peak value to alkaline pH in the latter. The same values of the apparent Km for NADPH and NADH were shown for the enzyme from the liver and tumor even 24 hr after the treatment with 3-methylcholanthrene, but a difference in the apparent Km for benzo[a]pyrene was demonstrated between the tumor and the host liver, showing 3.6 approximately 6.6 muM in the former and 9.1 approximately 20 muM in the latter. By the addition of 7,8- or 5,6-benzoflavone to the assay medium for the tumor, the induced enzyme was inhibited noncompetitively, and the constitutive enzyme was enhanced, as demonstrated in the host liver. As observed in the induced enzyme in both tissues, cyclohexene oxide and 1,1,1-trichloropropane oxide slightly increased the activity of the constitutive enzyme in the tumor, in contrast to its inhibition in the host liver.
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PMID:Properties of aryl hydrocarbon hydroxylase in microsomes of Morris hepatoma 5123D and the host liver. 0 50

A patient with papillary--follicular carcinoma of the thyroid, with metastases to the lungs, skeleton, and brain was treated 5 weeks after thyroidectomy with 135 mCi of 131I. Although preliminary studies with 1 mCi had not shown any iodine uptake by the brain metastasis, this lesion showed intense concentration at the time of the larger therapeutic dose. Four days later, acute hemorrhage of the tumor occurred, requiring surgical removal. Although 131I therapy would seem an unlikely cause of acute necrosis and hemorrhage in these lesions, the association of therapeutic radioiodine and hemorrhage is interesting. Since recent reports suggest that brain metastasis may be somewhat more common than previously suspected, we suggest that brain imaging be included in the workup prior to radioiodine therapy of patients with advanced metastatic disease or neurologic symptoms.
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PMID:Sudden hemorrhage in metastatic thyroid carcinoma of the brain during treatment with iodine-131. 0 32

The biochemical properties of cyclic nucleotide phosphodiesterases in a nonmetastasizing and a spontaneously metastasizing rat mammary carcinoma were compared. The phosphooiesterases in both tumors had a pH optimum of around 8.0 and preferentially hydrolysed cyclic purine nucleotides. The rate of hydrolysis of purine nucleotides in the nonmetastasizing tumor was two times higher than in the metastasizing tumor, but the rate of pyrimidine nucleotide hydrolysis was equal in both tumors. Theophylline, caffeine, and D,L-4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (Ro20-1724) inhibited the enzyme activity in both tumors; the percent inhibition was the same by each inhibitor. The cyclic nucleotie phosphodiesterase activity in either tumor was stimulated by Mg++, Mn++, and Co++ and suppressed by Ca++, Zn,++, and Ni++. EDTA inhibited the activity below the basal level (activity in the absence of added cation), an this inhibition could be recovered up to the basal level by an equimolar quantity of either Mn++ or Mg++. Further stimulation of the enzyme activity with increasing concentrations of divalent cations was observed only with Mn++. Similar effects were observe with ethylene glycol bis(beta-aminoethyl ether)-tn,n-tetraacetic acid. The stimulatory cations affected both the low and high Michaelis constant (tkm) enzymes in these tumors by increasing the maximum velocity. In the low Km enzyme, the Km was also slightly increased. Neither guanosine 3',5'-cyclic monophosphate nor adenosine 3',5'-cyclic monophosphate had any effect on the hydrolysis of the other at physiologic levels.
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PMID:Biochemical properties of cyclic nucleotide phosphodiesterase in metastasizing and nonmetastasizing rat mammary carcinomas. 0 60

Risk of cancer of the testis was related to nondescent and hernia in a comparison of 596 testicular cancer patients and 602 unaffected men who had been in active service in the U.S. Army between 1950 and 1970. Medical histories were obtained from routine service records. Undescended testis was associated with a testicular cancer risk 8.8 times that of normal. Among cancer patients with a history of undescended testis, seminomas were nearly twice as frequent as in the remaining patients. Of 14 patients with unilateral undescended testis, 12 had the tumor on the side of the defect. Testicular cancer risk was estimated to be 2.9 times higher in men who had reported having had an inguinal hernia than in those who had not. Side of hernia and side of tumor were not associated; histologic type was not related to history of hernia.
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PMID:Cryptorchidism, hernia, and cancer of the testis. 0 62

Tranfer of (14C)-gal from exogenous UDP(14C)-gal has been demonstrated with ovomucoid as glycoprotein acceptor in ascitic fluid sera from Balb/c mice bearing isogenic YC8 tumor. Transfer exists without ovomucoid, in great ratio in ascitic fluid and in sera from ascitic mice too, showing occurrence of endogenous acceptors, the origin of which has to be proved.
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PMID:[A glycoprotein: galactosyltransferase activity in the ascitic fluid and serum of mice with the YC8 tumor]. 0 34

Cortisol-sensitive and cortisol-resistant lymphoma P1798 cells specifically bind [25I]insulin. Resistant lymphocytes bind 40% less insulin than sensitive cells. These results suggest that insulin (or insulin-like substances) may play a role in growth regulation and/or response of this tumor to glucocorticoid therapy.
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PMID:Difference in the number of insulin binding sites between cortisol-sensitive and cortisol-resistant lymphoma P1798 cells. 0 12

The mechanisms controlling secretion of glucagon and other pancreatic hormones were studied in a patient affected with multihormone-secreting islet-cell tumor. Fasting glucagon levels (3,000 pg./ml.) rose to 10 ng./ml. following arginine stimulation. While oral glucose load and intravenous glucose infusion did not suppress glucagon secretion, insulin administration induced a prompt depression in glucagon levels. Glucagon, insulin, and gastrin levels were suppressed by somatostatin while calcium infusion caused a paradoxical increase. It is suggested that only some of the stimulation-inhibition mechanisms were conserved in this case of glucagon-secreting pancreatic tumor.
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PMID:Suppression and stimulation mechanisms controlling glucagon secretion in a case of islet-cell tumor producing glucagon, insulin, and gastrin. 0 26

The subcellular distribution and properties of guanylate cyclase was examined in preparations of normal rat renal cortex and Morris renal tumors MK2 and MK3. In normal kidney cortex about two-thirds of guanylate cyclase activity of homogenates was found in soluble fractions. With renal tumors the homogenate activity was less and the enzyme was equally divided between particulate and soluble fractions. The particulate enzyme in kidney cortex and tumors was associated with all particulate fractions. Triton X-100 increased the activity of all preparations. All preparations preferred Mn2+ as the sole cation. The stimulatory effects of Ca2+ on soluble enzyme and inhibitory effects on particulate activity were similar with preparations of renal cortex and tumors. ATP inhibited all preparations. Soluble and particulate guanylate cyclases from renal cortex were activated several-fold with 1 mM NaN3. Preparations of tumor enzymes did not respond to NaN3. Thus, compared to normal renal cortex the subcellular distribution of guanylate cyclase and some of its properties are altered in preparations of renal tumors.
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PMID:Properties of guanylate cyclase from rat kidney cortex and transplantable kidney tumors. 0 71

The presence of a growing tumor can lead to a significant curtailment of a graft-versus-host reaction as measured by the ability of allogeneic spleen cells to induce a host vascular response. This interference with the normal pattern of immunological reactions may be a reason for the survival of tumors in an immunologically alien environment.
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PMID:Lymphocyte-induced angiogenesis in tumor-bearing mice. 0 75

Two membrane fractions prepared from the Ehrlich ascites-tumor cell show non-identical stimulatory responses to certain amino acids in their Mg+2 -dependent activity to cleave ATP, despite the presence of ouabain and the absence of Na+ or K+. The first of these, previously described, shows little (Na+ + K+)-ATPase activity, and is characteristicallly stimulated by the presence of certain diamino acids with low pK2, and at pH values suggesting that the cationic forms of these amino acids are effective. The evidence indicates that these effects are not obtained through occupation of the kinetically discernible receptor site serving characteristically for the uphill transport of these amino acids into the Ehrlich cell. The second membrane preparation was purified with the goal of concentrating the (Na+ +K+)-ATPase activity. It also is stimulated by the model diamino acid, 4-amino-1-methylpiperidine-4-carboxylic acid, and several ordinary amino acids. The diamino acids were most effective at pH values where the neutral zwitterionic forms might be responsible. Among the optically active amino acids tested, the effects of ornithine and leucine were substantially stronger for the L than for the D isomers. The list of stimulatory amino acids again corresponds poorly to any single transport system, although the possibility was not excluded that stimulation might occur for both preparations by occupation of a membrane site which ordinarily is kinetically silent in the transport sequence. The high sensitivity to deoxycholate and to dicyclohexylcarbodiimide of the hydrolytic activity produced by the presence of L-ornithine and 4-amino-1-methyl-piperidine-4-carboxylic acid suggests that the stimulatory effect is not merely a general intensification of the background Mg+ -dependent hydrolytic activity.
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PMID:Amino acid stimulation of ATP cleavage by two Ehrlich cell membrane preparations in the presence of ouabain. 0 67


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