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)

1. The lipoproteins of the Ehrlich ascites tumor plasma were separated into 3 distinct fractions, very low density, low density and high density lipoproteins by preparative ultracentrifugation combined with agarose column chromatography. 2. High density lipoproteins contained 74% of the total protein in the lipoproteins. By contrast, most of the lipids were present in the very low density lipoprotein fraction. 3. The fatty acid compositions of the cholesteryl esters were appreciably different in the very low, low and high density lipoproteins, whereas phospholipid and triacylglycerol fatty acid compositions were quite similar in the 3 lipoprotein fractions. 4. Very low and high density apoprotein electrophoretic patterns on sodium dodecyl sulfate-acrylamide gels were similar to those observed in the corresponding lipoprotein fractions obtained from other mammalian species. The low density fraction, however, contained 7 apoprotein bands, and 32% of the low density apoprotein was soluble in tetramethyl urea. 5. The average molecular weights as determined by analytical ultracentrifugation were 2-10(7) (very low density), 6-10(6) (low density) and 4.4-10(5) (high density).
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PMID:Characterization of the Ehrlich ascites tumor plasma lipoproteins. 17 49

Mitochondria isolated from spontaneous and transplanted mammary adenocarcinomas of two strains of mice were compared, by various biochemical criteria, to mitochondria from mammary glands of midpregnant or hormonally stimulated, cancer-free mice. The specific activities of several mitochondrial enzymes including cytochrome oxidase, alpha-glycerophosphate oxidase, and succinate dehydrogenase were twofold to threefold lower, whereas the activity of monoamine oxidase was two fold higher in tumor mitochondria. Malate dehydrogenase, adenylate kinase, and NADH oxidase showed similar levels of activity in tumor and midpregnant mammary gland mitochondria. In addition, mitochondrial polypeptide composition was analyzed by electrophoresis on sodium dodecyl sulfate-urea polyacrylamide gels. Midpregnant mammary gland and mammary tumor mitochondria were similar in polypeptide composition; however, several differences were observed. A high-molecular-weight polypeptide, present in mid-pregnant mammary gland mitochondria was absent from tumor mitochondria. Also, tumor mitochondria contained an additional high-molecular-weight polypeptide not found in the midpregnant mammary gland. There were numerous differences in the relative proportions of many polypeptides common to both tumor and midpregnant mammary gland mitochondria.
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PMID:Biochemical studies on mitochondria isolated from Normal and Neoplastic Tissues of the Mouse Mammary Gland. 17 82

Two-dimensional polyacrylamide gel electrophoresis shows that in nuclei of Novikoff hepatoma ascites cells there are approximately 75 proteins in the chromatin fraction soluble in 3 M NaCl:7 M urea. Dialysis of this fraction to an ionic strength of 0.15 produces a soluble fraction and a precipitate. The proteins in the soluble fraction have been reported to be active in gene control. Antibodies to the soluble fraction distribute diffusely throughout the nucleus, and antibodies to the precipitate localized primarily in the nucleolus and the nuclear ribonucleoprotein network. The nucleolar proteins differ from the extranucleolar proteins in antigenicity and labeling patterns. The development of methods for isolation, purification, and identification of nuclear proteins provided the opportunity for analysis of chromatin antigens in tumor cells. Utilizing two-dimensional preparative polyacrylamide gel techniques as well as conventional procedures, several nuclear proteins have been isolated in electrophoretically homogeneous states including protein A-24, a histone-like nonhistone protein; C-14, a protein that stimulates nucleolar RNA polymerase; and a chromatin antigen soluble in 3 M NaCl:7 M urea that remains soluble after dialysis to 0.15 M NaCl to precipitate the histones and the DNA. This antigen has been found in the chromatin of both the Novikoff hepatoma and the Walker 256 carcinosarcoma but not in the chromatin of either normal or regenerating liver. It is a nonhistone nuclear protein as indicated by its amino acid analysis in which the ratio of the number of acidic to basic amino acids is approximately 1.4. Further studies are in progress on the function and structure of this chromatin protein. As an approach to analysis of relative rates of synthesis of this antigen and otherproteins, the products of translation of messenger RNA of Novikoff hepatoma and normal liver are being analyzed by autoradiography of two-dimensional electrophoretic gels.
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PMID:Antigenically active nonhistone chromatin proteins in cancer cells. 18 49

The rates of urea synthesis in rat liver and in a series of rat liver neoplasms with widely different growth rates and degree of differentiation were investigated using tissue slices incubated in a Krebs-Ringer bicarbonate buffer. Urea synthesis did not occur in fast-growing, poorly differentiated Novikoff and Morris 3924A hepatomas, but it did occur in slow-growing, well- and highly differentiated hepatomas; however, there was no correlation with growth rate or degree of differentiation. Urea synthesis was comparable with normal liver, at about 32 mumoles/hr/g tissue, in the slow-growing Morris hepatomas 21, 28A, 47C, and 44; but it was very low in two other slow-growing, highly differentiated hepatomas, 9618A and 20. The well-differentiated Morris hepatoma 5123C had intermediate levels of urea synthesis. This pattern of urea synthesis closely paralleled the previously reported activity of carbamyl phosphate synthetase in these tumors. The rate of urea synthesis was normal in livers of Buffalo rats bearing fast- or slow-growing hepatomas in low urea synthesis rates, but it was markedly lowered in the livers of rats bearing large, slow-growing tumors with high urea synthesis rates. Urea synthesis in liver declined as the tumors increased in size. The total rate of urea synthesis in liver and tumor, as well as the concentrations of urea in the serum and urine of tumor-bearing animals, remained remarkably constant throughout the period of tumor growth, suggesting the existence of a homeostatic mechanism that controls the urea cycle activity in accordance with the synthetic activity of the tumor. In parabiotic animals, carbamyl phosphate synthetase activity and urea synthesis were lowered in the host livers of partners bearing tumors with high carbamyl phosphate synthetase- and urea-synthetic activity, but there was no significant effect on urea cycle activity in the normal partners. This result discounts the likelihood of a circulating humoral factor that controls hepatic urea cycle activity.
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PMID:Urea synthesis in Novikoff and Morris hepatomas. 18 16

These studies were undertaken to characterize the high molecular weight immunoreactive insulins in plasma and tumor extracts of two patients with insulinoma, and to determine whether they are biosynthetic precursors of proinsulin. Plasma was chromatographed on a Sephadex G-50 column and fractions assayed for IRI. Three peaks were observed, one in the void volume region (6%), a peak in the proinsulin region (25%), and the largest peak comigrating with insulin standard (69%). Insulinoma slices were incubated for 4 h and high molecular weight IRI was observed in chromatographed extracts of the tumor, as well as in extracts of the incubation medium, which comprised up to 3% of the total IRI. Gel filtration chromatography of a pre-operative fasting plasma from the second patient revealed a heterogeneous distribution of IRI, with approximately 53% in the high molecular weight region. At surgery an insulinoma was removed. Slices were incubated for 4 h with 14C-amino acids and extracts chromatogrphed. 14C-labeled protein was observed in the V0, and in the proinsulin and insulin regions. These 14C-labeled proteins were precipitated with anti-insulin serum, and it was determined that whereas 60-90% of 14C-protein in the proinsulin-insulin region was precipitated, virtually none of the 14C-protein in the V0 was immunoprecipitated with anti-insulin serum. The specific activities (CPM precipitated by anti-insulin serum/muU IRI) were 1, 11.4, and 3.1 for V0, proinsulin, and insulin regions, respectively. These results suggest that proinsulin is synthesized first, followed by insulin, and then the high molecular weight IRI. The high molecular weight IRI is not a biosynthetic precursor of proinsulin. Rechromatography of the high-molecular weight IRI in the presence of 8M urea dissociated 90% into smaller immunoreactive components which chromatographed in the proinsulin and insulin region. It was concluded that high molecular weight IRI's are present in plasma, tumor extracts, and incubation medium from insulinoma patients. These high molecular weight IRI's are not biosynthetic precursors, but either aggregates of proinsulin and insulin, or insulin bound to larger proteins. These studies do not rule out the existence in humans of a smaller rapidly-turning over precursor to proinsulin similar to the pre-proinsulin discovered in a rat insulinoma by Chan et al.
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PMID:Characteristics of high molecular weight insulins in insulinoma patients. 19 Feb 61

Nephroblastomas are induced in rats with N-Methyl-N-Nitroso-Urea, and selective renal artery occlusion is performed. This procedure has the same effect like occlusion by embolization. The effect of renal artery occlusion on the growth rate of nephroblastmas is controlled by angiography and gross and microscopic examinations up to 70 days following ischemia, the results are compared with a group of untreated nephroblastoma rats. There is a marked reduction of tumor size and a decrease in tumor proliferation. There is an immediate tumor cell death induced by acute and complete ischemia. Collateral blood vessels cause residual arterial blood supply of tumor parenchyma. There seems to be a correlation between collateral blood delivery and tumor size. Even 70 days after permanent ischemia there are areas of obviously absolute normal tumor cells. The conclusion of this experimental study demonstrated that growth rate of tumors can be reduced by ischemia although potentially malignancy still remains. Clinical embolization therapy is justified only in nonoperable patients with hypernephroma and with massive hematuria.
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PMID:[The influence of renal artery occlusion on tumor growth of experimental nephroblastomas (author's transl)]. 20 93

Carcinoembryonic antigen (CEA) was isolated from a human tumor with 0.02 M sodium phosphate containing 0.14 M NaCl (pH 7.0) (saline) and further studied after treatment with perchloric acid or 8 M urea. Preparations CEA obtained from saline homogenates and both methods of treatment were characterized by isoelectric focusing and gel filtration. Perchloric acid treatment resulted in an approximate 10-fold decrease in protein and a significant loss of CEA as compared to the saline- and urea-treated material. Isoelectric focusing revealed that the resultant CEA subpopulations were dependent upon the method of isolation. Urea- and saline-treated material showed complex isoelectric patterns that were quantitatively dissimilar. Perchloric acid-treated material showed a comparatively simple isoelectric pattern that was not significantly affected by electrofocusing in the presence of urea. Gel filtration on ACA 34 of the CEA obtained from each method of isolation resulted in two peaks of activity. The first peak corresponded to the void volume of the column, and the second peak coeluted with commercially available purified 125I-labeled CEA. Centrifugation of the peaks obtained resulted in a significantly greater loss of CEA from the void peak of each isolation procedure. The amount of CEA lost from the void peaks following centrifugation differed with each method of isolation and suggested the presence of aggregates.
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PMID:A comparison of methods for the isolation of carcinoembryonic antigen. 20 87

Employing high-resolution polyacryl-amide gradient slab-gel electrophoresis in 6M urea and 6% acetic acid, a distinct change in the microheterogeneity of histone H1 was detected after mengovirus infection of Ehrlich ascites tumor cells. Whereas in uninfected cells the band multiplicity was found to be 6, it was reduced to 4 in the course of the infectious cycle (8 to 9 h). It could be deomonstrated that, while the electrophoretically slowly moving subspecies H1e and H1f disappeared from the band profile of histone H1, the faster migrating bands H1a and H1b increased in relative intensity. The relative intensity of band H1d was also drastically reduced, that of band H1c stayed practically constant throughout infection. When Ehrlich ascites tumor cells were labeled with a mixture of [14C]amino acids prior to mengovirus infection, the radioactivity incorporated into histone H1 subspecies of low electrophoretic mobility was chased into histone H1 components of high mobility in the course of infection, suggesting a virus-induced, unidirectional interconversion of the multiple histone H1 subunits. With the exception of a histone H2B subspecies, which also decreased in amount, the relative quantities of the other histones stayed constant throughout infection.
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PMID:Changes in the microheterogeneity of histone H1 after mengovirus infection of Ehrlich ascites tumor cells. 20 45

A study was performed on 30 patients diagnosed antomopathologically for malignant neoplasia of the lung (epidermoid carcinomas, adenocarcinomas, oat-cell carcinomas, and neoplasias which could not be definitely classified). The following parameters for blood and urine were determined: osmolality, sodium, potassium, urea, and creatinine. Osmotic free water, creatinine, sodium, and potassium clearances were also calculated, as well as the plasma osmolality/urinary osmolality ratio. The basic aim of our study was to investigate for the presence of disturbances in the metabolism of water and alterations in plasmatic and urinary osmolality in this type of tumor. These could appear as complete inadequate ADH secretion syndromes as discovered by Bartter and Schwartz or as incomplete syndromes (hypoosmolality and/or hyponatremia). Among the more significant results was the tendency toward oliguira seen in 44% of the patients and the high incidence of plasmatic hypoosmolality (31%). In three patients plasmatic hypoosmolality and hyponatremia were concommitant in repeated observations. A complete inadequate ADH secretion syndrome was discovered in another patient with an oat-cell carcinoma. He presented plasmatic hypoosmolality, hyponatremia, relative urinary hypertonia, and oliguria but not renal, suprarenal, or hepatic pathology.
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PMID:[Investigation of the hypoosmolal syndrome in carcinomas of the lung (author's transl)]. 22 78

On gel filtration of acid-ethanol extracts from three pancreatic beta-cell adenomas 1.4% to 1.8% of total immunomeasurable insulin (IMI) eluted ahead of proinsulin. This high molecular IMI was resolved into three components. The presence of urea in the dilute acetic acid solutions of extracted tumor tissue did not influence the pattern of gel filtration. High molecular IMI dissolved in dilute acetic acid showed to be stable if immediately rechromatographed, but a partial dissociation to insulinlike and proinsulinlike components (ILC and PLC) was found if rechromatography was performed after 48 h of incubation. Mainly ILC and PLC were found on rechromatography provided high molecular IMI was dissolved and incubated briefly in 0.04M phosphate buffer, pH 7.4. It proved improbable that the proteolytic action of some protein being extracted with the hormones caused a splitting of high molecular IMI at pH 7.4. We conclude from our findings that the components of high molecular IMI are not precursors of proinsulin and insulin but are either self-associated products of the hormones or associations of insulin and proinsulin to other proteins extracted from insuloma tissue.
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PMID:Chromatographic heterogeneity of insulin extracted from insulomas. 23 76


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