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

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

The function of: (see article), fits the tumors weight growth for all studied generations in both control and treated animals. Morphological studies show the transplantable tumors in A mice to lose their similarity to a spontaneous tumor--low differentiated adenocarcinoma. Meanwhile, the tumors in C3H mice have a high differentiation level which is typical for the original tumor. 1-nitroso-1-methylurea is very effective against the first generation of tumors in both strains of mice. The tumors response to the drug becomes weaker with further passages. 1-nitroso-1-methyl urea is superior to other nitrous derivatives when used in such tumor models as breast adenocarcinoma in C3H mice.
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PMID:[Growth kinetics of transplantable mammary gland tumors in mice]. 118 55

In fifty patients with cancer, subjective and objective correlates of anorexia of malignancy were studied. Decreased taste was reported by 25 patients, and an aversion for meat was reported by 16 patients. The decreased taste symptom correlated with an elevated taste threshold for sweet (sucrose), and the symptom of meat aversion correlated with a lowered taste threshold for bitter (urea). The likelihood of having a taste abnormality increased with increasing extent of disease, but not with histologic type of neoplasm. Patients with an abnormality of taste had an increased incidence of weight loss compared with patients with normal taste, even though many in the latter group had other causes of weight loss. These observations suggest that an abnormality of taste may be one determinant of the anorexia of malignancy. Better understanding of the anorexia in the cancer patient may contribute to the care of the patient.
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PMID:Abnormalities of taste sensation in cancer patients. 119 73

The brain immediately surrounding 9L sarcoma and Walker 256 carcinosarcoma was evaluated, using radioactive water, albumin, red blood cells, urea, and sodium to quantitate isotopic exchange and permeability in the brain adjacent to tumor (BAT), normal brain, and, to a lesser extent, tumor. Exchange between blood and BAT for 14C-urea and 22Na averaged 53% of that for comparable regions of normal brain. This reduction in exchange is not explainable by differences in capillary surface area for transcapillary exchange in the BAT. This reduction in capillary permeability in the BAT could be detrimental to the delivery of watersoluble and rapidly binding drugs.
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PMID:Permeability characteristics of brain adjacent to tumors in rats. 120 30

It could be demonstrated by own investigations that ENU-tumors (brain-tumors induced with Ethyl-Nitroso-Urea) are better for clinical questions than the usual transplantation tumors. In this experimental study the temporal and quantitative condition of accumulation of 64Cu-Dimethylglyoxim and 59Fe-Acetyl-Acetone was investigated in rats with ENU-tumors compared with 99mTc-Pertnetate and and 67Ga-Citrate to answer the questions wether 64Cu-Dimethylglyoxim and 59Fe-Acetyl-Acetone are qualified for brain scanning. 64Cu-Dimethylglyoxim and 59Fe-Acetyl-Acetone show like 99mTc-Pertechnetate and 67Ga-Citrate certain affinity to the tumor. At the same time they accumulate in healthy tissues, too. The kinetice of the single radiopharmaceuticals is different. The rates of accumulation of 64Cu-Dimethylglyoxim after 24 hours and of 59Fe-Acetyl Acetone after 4 hours correspond to the rates of accumulation of 99mTc-Pertechnetate after 1 hour. Opposite to this rates of accumulation of 67Ga-Citrate are, because of the high accumulation in the bone, distinctly worse. There are 3 consequences: 1. Brain scintigraphical investigations should not be made with 67Ga-Citrate. 2. Brain scans with 64Cu-Dimethylglyoxim and 59Fe-Acetyl-Acetone will give no better results than scans with 99mTc-Pertechnetate. 3. Further investigations with 64Cu-Dimethylglyoxim and 59Fe-Acetyl-Acetone are not indicated.
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PMID:[Experimental results with new radiopharmaceuticals in autochthon brain tumors of rats (author's transl)]. 122 56

The ribosomes from Novikoff tumor and rat liver cells were extracted, purified and analyzed. The isolated ribosomes are active in Poly-U directed Poly-Phe synthesis. Sucrose density gradient centrifugation showed that the Novikoff tumor cells contained, in contrast to liver cells, almost no polysomes. The ribosomal proteins from the ribosomes were extracted and subsequently analyzed by gel electrophoresis. No differences between the ribosomal proteins of the normal and neoplastic cells could be detected by one-dimensional sodium dodecyl sulfate gel electrophoresis. Two-dimensional urea gel electrophoresis showed great similarities between the ribosomal proteins of the two kinds of cells. However some differences could be detected.
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PMID:The ribosomes of the Novikoff tumor cells: isolation, general properties and electrophoretic analysis of the protein moiety. 122 41

We have earlier reported production and characterization of monoclonal antibodies (MAbs) to human thyroglobulin (h-tg). In the present study H10 I MAb was evaluated for its immunoreactivity towards different forms of tg and various human thyroid tumours. The specificity of H10 I MAb was validated by the absence of cross reaction with tri-iodothyronine (T3) Thyroxine (T4) and human gamma globulins. Sodium-dodicyl-sulphate polyacrylamide gel electrophoresed (SDS-PAGE) immunoblot of h-tg on the nitrocellulose membrane revealed multiple immunoreactive bands on reaction with polyclonal antibody (PAb) in comparison with total lack of reactivity with H10 I MAb. The absence of immunoreactivity of H10 I MAb was demonstrated with SDS treated, Dithiothreitol (DT) treated and heat denatured tg using dot immunobinding technique. However, the H10 I MAb was able to react with tg treated with unfolding agents such as urea and guanidine hydrochloride. All the treated forms of tg were equally recognized by PAb. The immunoreactivity of the oxidized/reduced tg towards H10 I MAb was markedly reduced (60.0%) as compared to that obtained with native tg. It appears that H10 I MAb is directed towards conformational epitope involving sulphydryl bonds. Immunohistochemically, a comparable immunoreactivity between PAb and MAb was observed with normal thyroid tissues, follicular thyroid tissues, Hurthle cell carcinoma tissues and poorly differentiated thyroid tumor tissues using immunoperoxidase staining. The sections from papillary carcinoma tissue (thyroid as well as metastatic lymph node) exhibited intense immunoreactivity with PAb. Thyroglobulin present on these sections was not recognized by H10 I MAb. Nonetheless, H10 I MAb was able to detect tg in follicular differentiation wherever present. The absence of immunoreactivity of H10 I MAb in papillary carcinoma strongly suggests that this neoplasm produces tg which is antigenically different from the protein present in the normal tissue. The reactivity of H10 I MAb with metastatic lymph node of an unknown primary origin suggests its usefulness in the identification of prevalent metastasis of differentiated thyroid carcinoma other than papillary type.
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PMID:Monoclonal antibodies to human thyroglobulin: evaluation of immunoreactivity. 128 24

This paper refers to some of the chemical and biological properties of a new platinum (II) complex where the aromatic amino group of procaine is involved in the coordination with platinum and whose structure was defined by UV, IR, 1H-NMR, and elemental analysis. This new cationic platinum-triamine complex (DPR) displays excellent solubility (> 50 mg/ml) and stability in water. DPR has significant in vitro cytotoxicity against murine P388 leukemic cell line, human K562 erythroleukemic cell line and human Jurkat T cell line. The in vitro cytotoxic effects of DPR on P388 and Jurkat leukemic cells were comparable to those of cis-diamminedichloroplatinum (II) (DDP), while its activity on K562 cells was significantly better than that of DDP [IC50 = 1.07 +/- 0.36 (SD) microM vs 2.62 +/- 0.23 (SD) microM, P < 0.01]. The in vitro Pt accumulation rate for P388 cells was twice as rapid after DPR than after DDP exposure, while no difference in cellular platinum efflux was observed. The antitumor activity of DPR was tested in vivo against P388 leukemic cells in BDF1 mice and gave a % ILS value (75%) similar to that of the maximum tolerated dose (MTD) of DDP (8 mg/Kg). A comparative study of plasma urea nitrogen (PUN) levels and kidney morphological analysis in tumor-bearing mice receiving the LD50 dose of both drugs (39.3 mg/Kg and 16.5 mg/Kg for DPR and DDP, respectively), showed DPR to be less nephrotoxic than DDP. These results indicate that this new cationic platinum-triamine complex containing primary amine ligand is surprisingly active both in vitro and in vivo. In summary, the good characteristics of DPR in terms of high solubility, encouraging anticancer activity and absence of nephrotoxic effects make DPR a promising new platinum anticancer agent for preclinical development.
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PMID:Synthesis and antitumor activity of a new cis-diammineplatinum (II) complex containing procaine hydrochloride. 129 76

The expression of nucleoside diphosphate kinase (NDK) genes has been implicated as a negative regulator of murine and human tumor metastases and is critical to proper development in Drosophila melanogaster. Molecular mechanisms for the role(s) of NDK in these complex processes have not yet been elucidated, but several reports have suggested that these and many other signal transduction pathways may be activated by NDK acting directly on a regulatory GTP-binding protein(s). To test this hypothesis, we examined the ability of NDK to catalyze the phosphorylation of the GDP bound to the following three members of the superfamily of regulatory GTP-binding proteins: Gt, Ha-ras p21, and ARF. We have found no evidence to support the hypothesis that NDK can directly activate any GTP-binding protein. Rather, evidence is presented which clearly shows that all of the GTP formed upon incubation of GTP-binding proteins with NDK is the result of NDK utilizing free GDP as substrate. The GDP bound to the regulatory proteins is not a substrate for NDK under conditions in which free nucleotides are rapidly and efficiently phosphorylated. The importance of appropriate controls for dissociation of GDP from the regulatory proteins both during the NDK reaction and during the analysis of product is demonstrated. We believe there is currently no experimental evidence to support the hypothesis that NDK can directly activate a regulatory GTP-binding protein.
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PMID:Regulatory GTP-binding proteins (ADP-ribosylation factor, Gt, and RAS) are not activated directly by nucleoside diphosphate kinase. 132 60

The relative levels of mitochondrial specific gene transcripts were compared in two murine large cell lymphoma cell lines that differ in their propensities to form liver metastases and in their sensitivity to macrophage mediated antitumor cytostasis and cytolysis. Full-length transcripts of the mitochondrial genes were hybridized on electroblots from citrate/urea gels with specific gene prodes. The mitochondrially encoded gene NADH dehydrogenase subunit 5 (ND5), that encodes a component of NADH dehydrogenase (complex I) of the electron transport chain, was significantly overexpressed in the highly metastatic RAW117-H10 compared to low metastatic RAW117-P cells. Results from analysis of RNA blots were confirmed in an S1 nuclease protection assay. Since RAW117-H10 cells are significantly more resistant to cytostasis by activated macrophages in coculture and such macrophage activity can inhibit RAW117 tumor cell respiration and growth, a mechanism was suggested that allows RAW117 cell escape from certain host effector mechanisms that block cellular respiration by an increase in the in vivo concentrations of translatable messenger RNA (mRNA) that codes for key components of the electron transport chain.
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PMID:Transcripts of the mitochondrial gene ND5 are overexpressed in highly metastatic murine large cell lymphoma cells. 138 22


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