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

Rhodium(II) acetate, propionate, and butyrate showed a considerable variation in their antitumor activity against Ehrlich ascites tumor cells in mice, with the butyrate complex being the most active. The three complexes markedly inhibited DNA synthesis of Ehrlich ascites tumor cells in vivo. Rhodium (II) butyrate was the most potent inhibitor followed by the propionate complex. One hour after administration, rhodium(II) propionate and butyrate induce more uridine-5-3H incorporation into RNA than is seen in the controls. Equilibrium dialysis studied showed that rhodium(II) acetate-1-14C binds to single stranded DNA, poly-A, ribonuclease A, and bovine serum albumin but not to highly polymerized native calf thymus DNA, poly-G, or poly-C. In these cases binding occurred at the two axial positions of rhodium(II) acetate to a nitrogen donor in the ligands. The formation constants of the rhodium(II) acetate and propionate complexes with 5'-adenosine monophosphate were determined. The rhodium(II) propionate complex was more stable. Sedimentation and viscosity measurements of poly-A and poly-A/rhodium(II) acetate complexes indicate a high degree of intramolecular crosslinking in the rhodium(II) acetate/poly-A complex. The rhodium(II) carboxylate complexes were also found to be potent inhibitors of purified DNA polymerase I and RNA polymerase from Escherichia coli.
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PMID:Interaction of Rhodium(II) carboxylates with molecules of biologic importance. 110 39

Encephalitis developing after prolonged antineoplastic therapy in two patients with Hodgkin's disease and in one with multiple myeloma was found at autopsy to be caused by toxoplasmosis. To better understand the pathogenesis of the brain lesions, ranging from microscopic foci to some having a diameter of 6 cm. and characterized by proliferation of the organisms at the margins of expanding necrosis, an animal model was studied. Similar lesions were produced in hamsters by inducing relapse of chronic latent toxoplasmosis through administration of cortisone, cyclophosphamide, or whole body irradiation, but toxic doses of nitrogen mustard and urethane did not precipitate relapse. Notably, relapsing toxoplasmosis generally involves the brain exclusively, suggesting a special susceptibility related to immune mechanisms. The roles of cells and of antibodies in immune surveillance against this chronic infection in otherwise normal hosts are considered. In man the suppression of cellular immunities by certain antineoplastic agents would seem to be decisive in causing relapse of toxoplasmosis, rather than the replacement of immunologically active cells by neoplasm. Because the infection can be controlled with sulfadiazine and pyrimethamine, a high index of suspicion is essential to detect incipient cerebral toxoplasmosis. serial serologic testing is helpful by demonstrating titer elevations; however, poor antibody production or transferred antibody may be misleading clinically when single tests are evaluated. Similarly, a poor inflammatory cell response can make it difficult for the histopathologist to detect small lesions in these patients.
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PMID:Immunosuppression and toxoplasmic encephalitis: clinical and experimental aspects. 111 86

Mycophenolic acid, a novel antibiotic of low toxicity containing no nitrogen atoms in its structure, induces tumor regression in several murine solid tumor assays. It has been reported in extensive structure-activity studies that chemical modifications on the antibiotic itself reduce or eliminate antitumor activity. With the objective of antitumor activity enhancement, nitrogen-containing analogs of mycophenolic acid were synthesized according to a program directed toward the ultimate synthesis of close bioisosteres of the antibiotic. Intial efforts reported here describe the terpenoid side-chain degradation of N-geranyl-2(1H)-pyridones and N-geranylglutarimides, where the terminal isopropylidene is replaced with a carboxyl group as it occurs in mycophenolic acid. The resulting nitrogen-containing analogs of the antitumor antibiotic were inactive in the l-1210 and Walker 256 tumor systems.
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PMID:Antitumor agents II: nitrogen analogs of mycophenolic acid. 113 12

Bilateral nephrectomy, renal perfusion and bench surgery have been used in the management of synchronous bilateral renal pelvic tumors in a 35-year-old man. The possibility of bilateral nephrectomy followed by hemodialysis and eventual transplantation was considered but was not done because we believe for the present time that the nature of the immune response and its importance in the pathogenesis of cancer are complicated and poorly defined. It is likely that immunosuppression may tip the balance toward the tumor. Bench surgery allowed us to perform radical resection of these urothelial tumors yet preserve enough renal tissue to sustain life. This patient is now enjoying an active life and has a blood urea nitrogen of 30 mg. per cent and a serum creatinine of 1.2 mg. per cent from the functioning third of the former right kidney.
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PMID:The treatment of bilateral synchronous renal pelvic tumors with Bench surgery. 114 35

The response of a model brain tumor system in the rat to single doses of x irradiation has been studied. Solid tumors were exposed in situ, removed, dissociated into single cells, and grown in tissue culture. The fraciton of surviving clonogenic cells wasdetermined as a function of x-ray dose level for tumors irradiated in anesthetized, air-breathing rats, and for tumors irradiated in rats killed 5 minutes prior to irradiation bynitrogen gas asphyxiation. The parameters of the survival curve for tumors irradiatedin air-breathing rats were: DO= 295 rads; DQ= 350 rads; and n= 3.0. Similarly, thesurvival parameters for tumors irradiated in nitrogen gas asphyxiated rats were: DO=625 rads; DQ=675 rads; and n= 3.0. The survival curve of these tumor cells when assayed in in vitro tissue culture only has parameters of: DO= 225 rads; DQ= 350 rads; andn= 4.7. Data form the in vivo to in vivo tumor cell survival curves suggest that there is no significant hypoxic fraction in this brain tumor.
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PMID:Cellular radiosensitivity of a rat brain tumor. 114 88

Immediate and delayed effects of nitrogen mustard (HN2) (0.1 mg/kg/day for 4 days) on the growth and cell proliferation patterns of the 3-methylcholanthrene-induced autogenous rat sarcoma were studied. Tumor cells were labeled continuously with 0.5 muCi tritiated thymidine/g for 24 hours. The labeling index fell from 36.4 to 14.0% and the mitotic index from 0.88 to 0.67% after two treatments with HN2. At that time, tumor growth stopped and remained arrested during HN2 administration. After four injections of HN2, the labeling index was reduced further to 0.73% and the mitotic index to 0.36%. After the drug was withdrawn, tumor growth resumed at the pretreatment rate, even though the labeling index on day 3 was only 15.5% (or 40% of the control). The percent labeled mitosis curves and DNA contents, before and 4 days after HN2 was given, were similar. It was concluded that a subpopulation of cells of predominantly short intermitotic times caused tumor growth before and after drug treatment.
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PMID:Growth and regrowth of an autogenous rat sarcoma: effects of nitrogen mustard. 115 48

Ethanol-insoluble components were extracted from fresh garlic with 0.9% NaCl solution containing streptomycin and penicillin. This extract, containing approximately 10% sugar, 0.3% nitrogen, and 0.4% ash, was termed garlic sugar solution. This garlic sugar solution (Medium 1) was used as the suspending medium for Ehrlich ascites tumor cells attenuated with allicin, the main principle of garlic, and 0.9% NaCl solution containing streptomycin and penicillin (Medium 2) was also used as the suspending medium. Mice of DDD strain were immunized with the attenuated tumor cells suspended in Medium 1 or 2. After immunization, the immunized and control mice were challenged intraperitoneally with viable Ehrlich ascites tumorcells. Animals immunized with the attenuated tumor cells suspended in Medium 1 acquired significantly stronger resistance against the tumor cells than animals immunized with those suspended in Medium 2.
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PMID:Adjuvant action of garlic sugar solution in animals immunized with Ehrlich ascites tumor cells attenuated with allicin. 118 76

Previous studies from this laboratory indicated that inorganic and organic anions inhibit the unidirectional influx and net transport of the folate analog methotrexate in mammalian cells. Studies were undertaken to establish whether anions retained in uremia might inhibit the membrane transport of folates. Methotrexate was utilized as a model folate compound and its transport was determined in the Ehrlich ascites tumor cell. Influx of methotrexate was inhibited when cells were suspended into sera or ultrafiltrates of sera (pH adjusted to 7.4 by regulation of PCO2) from uremic patients, an effect that was decreased after the patient underwent hemodialysis or peritoneal dialysis. The inhibitory effect of uremic sera correlated well with the level of retained anions as estimated from the "anion gap," but could not be related to changes in osmolality, blood urea nitrogen (BUN), sodium, potassium, calcium, or magnesium. While inhibiting the influx of methotrexate, inorganic anions did not displace methotrexate from albumin binding sites. Anionic inhibition of the membrane transport of 5-methyl [14C] tetrahydrofolate was also demonstrated and this was shown to be accompanied by a depression in the rate of incorporation of the labeled 14C moiety into nucleic acids and protein. The data suggested that transport of folates is impaired in uremia and raises the possibility that whatever the measured blood folate level in the uremic individual with retained anions, the rate of uptake of folates into folate-dependent tissues which this blood folate level will sustain may be reduced.
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PMID:Inhibition of the membrane transport of folates by anions retained in uremia. 118 41

Ninety-two courses of daily low-dose intravenous nitrogen mustard were administered to 46 patients with advanced cutaneous lymphomas (mycosis fungoides, Sezary syndrome and lymphoma cutis). Seventy-eight % of patients showed objective clinical remission, and 35% reached a clinically disease-free state following 1 or more courses. The response rate was greater in patients with the plaque-tumor type of mycosis fungoides than in those with erythrodermic variants. Therapy was free of significant side effects.
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PMID:Frequent low doses of intravenous mechlorethamine for late-stage mycosis fungoides lymphoma. 119 53

In rabbits transplanted Brown-Pearce carcinoma the content of nitrous compounds in tissues is changed in a different way: in the liver and kidneys -- nitrous compounds are accumulated, while in cardiac and skeletal muscles their concentration is diminished. It is found that tumor cells in mice with Ehrlich carcinoma accumulate radioactive aminoacid considerably faster than adjacent tissues not involved by neoplasma. A continuous glucose administration in tumor-bearing rabbits renders a marked nitrogen-saving effect by means of attenuation of catabolism of myoproteins, as a result of it the balance between the processes of synthesis and catabolism in host tissues is shifted toward synthesis.
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PMID:[Correlation of some nitrogenous compounds in the blood and tissues of tumor-bearing rabbits in hyperglycemia]. 119 83


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