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

Tissue albumin distribution was measured in Walker 256 tumor and skeletal muscle in vivo in 36 rats. Vascular, extravascular-extracellular, and total tissue water spaces were determined for each tissue sample by isotopic techniques. Tissue interstitial and lymph albumin values were calculated from thoracic duct albumin concentrations, and vascular albumin was determined from serum albumin levels. Total tissue albumin was measured by dilution. These data demonstrate a third tissue albumin pool that equilibrates in 3 days compared to the rapid equilibration (2 hr) of vascular and extracellular-extravascular spaces. The pool is present in both muscle and tumor but appears to equilibrate more rapidly in tumor tissue. This finding suggests that cellular ingress of albumin occurs in vivo, which may explain increased albumin catabolism in tumor-bearing hosts.
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PMID:Apparent cellular ingress of albumin in Walker 256 tumor and rat muscle. 110 5

This paper describes the modification of Centrifugal Cytology for the preparation of permanent, fixed, stained dispensions for both light and scanning electron microscopy of cells which have been isolated on bovine serum albumin (BSA) boyant density gradients. The principal problem with BSA gradient fractions is that the albumin which is present even after dilution is precipitated by the glutaraldehyde fixative. This problem has been solved by the layering of an intermediate D2O solution under the BSA and subsequent removal of the BSA solution and the underlaying with D2O containing glutaraldehyde. A special layering machine facilitates and expedites these operations. This technique has also been applied to BSA-seperated guinea pig and chicken bone marrow cells, as well as Ehrlich ascites tumor cells, hen and human blood cells. The number of celll present in each area of the slide is maintained at a constant value by utlizing a table of dilution factors. This table was generated by a computer program which calculates the concentration of cells present in the rractions and divides it by the number of celll desired.
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PMID:Centrifugal cytology. III. The utilization of centrifugal cytology for the preparation of fixed stained dispersions of cells separated by bovine serum albumin bouyant density centrifugation. 112 22

Glyceraldehyde 3-phosphate dehydrogenase and 3-phosphoglycerate kinase are, together with some other enzymes, present on the surface of intact Ehrlich tumor cells. Aldolase, on the contrary, represents cytoplasmic enzymes not present at all on the external surface, provided 2.5 percent of bovine albumin is included in the isotonic assay medium. A flux of aldolase from the cell interior to the cell exterior could be demonstrated in the absence of albumin. Therefore, any enzymatic activity monitored when keeping the Ehrlich tumor cells in the isotonic assay medium containing 2.5 percent albumin was considered to be primarily related to the outside of the plasma membrane. Of the total glyceraldehyde 3-phosphate dehydrogenase, 0.7 percent was located on the outer surface of the tumor cell, while the corresponding figure for 3-phospoglycerate kinase was 2.7 percent. Eighty percent of this surface-located 3-phosphoglycerate kinase was released into the assay medium during incubation, while the release of glyceraldehyde 3-phosphate dehydrogenase, at the same time, was minimal. A plasma membrane preparation of Ehrlich cells, mainly consisting of vesicles, showed the presence of 3-phosphoglycerate kinase but the absence of glyceraldehyde 3-phosphate dehydrogenase. Because of the vesicular nature of the membrane preparation, it was assumed that only one side of the membrane was exposed during assay. The specific binding properties of the two enzymes to the plasma membrane, as well as possible differences in their intramembranous location, are discussed.
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PMID:Enzyme activities at the surface of intact Ehrlich tumor cells with albumin in the isotonic assay medium. 113 21

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 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

A prospective study has been conducted to determine the clinical importance of lung scintigraphy in the work-up of patients thought to have bronchial carcinoma (i.e., accuracy of the scintigraphic diagnosis, data concerning spread of the primary tumor [=T] as well as the possibility of metastases to the lung hilus and mediastinum [=N]). Ninety-four patients, all of whom were hospitalized for suspected bronchial carcinoma, were examined by 133Xenon i.v., 133Xenon gas inhalation,, and 99mTc-MAA i.v. (macroaggregated albumin or microspheres of human albumin). The suspicion was confirmed in 77 patients. Central and peripheral bronchial carcinomas were kept separate in the evaluation. A normal lung scintigram practically rules out a central bronchial carcinoma. Where the scintigraphic finding prompts suspicion of central bronchial carcinoma, this suspicion must be confirmed by other examinations and preferably those which cytologically and histologically directly demonstrate the tumor. The diagnostic reliability of lung scintigraphy is drastically reduced in patients with bilateral ventilation disturbances. Because of its 27% rate of false negative findings, bronchoscopy is a less suitable means of ruling out bronchial carcinoma than scintigraphy. The peripheral bronchial carcinoma displays no characteristic scintigraphic signs; thus, a normal scintigram does not rule out peripheral bronchial carcinoma. Bronchoscopy was negative in all these patients. Spread of the primary tumor was exactly predicted with bronchoscopy in 11% and with scintigraphy in 42% of cases. When the scintigraphic criteria for hilar or mediastinal involvement are ful filled, it is practically certain that the patient is no longer radically operable. This assertion is valid when mediastinoscopy is normal. Lung scintigraphy possesses the same accuracy in the diagnosis of mediastinal involvement both with peripheral lung tumors and with centrally located tumors.
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PMID:[The value of lung scintigraphy in the staging of bronchial carcinoma. Prospective study for the determination of TN stages]. 125 Nov 66

To decrease the toxicity of hepatic arterial fluorodeoxyuridine (FUDR) administered through an Infusaid pump (Shiley Infusaid, Inc., Norwood, MA), 50 patients with liver metastases from colorectal cancer were selected randomly to receive FUDR, 0.3 mg/kg/d, for 14 of 28 days, with or without a total dose of 20 mg of hepatic arterial dexamethasone for 14 of 28 days. Patients were stratified according to the percentage of liver involvement by tumor and the perfusion pattern on macroaggrated albumin perfusion scan (MAA) scan. There was a trend toward decreased frequency of bilirubin levels in the group receiving dexamethasone plus FUDR versus the group receiving FUDR alone (9% and 30%, respectively, had a 200% or greater increase from baseline; P = 0.07). Patients in the group treated with dexamethasone and FUDR received higher doses of FUDR in the second, third, fifth, and sixth months than those receiving FUDR alone; however, this was statistically significant only in the fifth month (percentages of planned dose received: 42% and 19%, respectively; P = 0.05), and there was no overall difference for the total 6-month period. The complete and partial response rates were increased in patients receiving dexamethasone and FUDR versus FUDR alone (8% and 63% versus 4% and 36%, respectively; P = 0.03), and there was a trend toward increased survival with the addition of dexamethasone (median, 23 months and 15 months, respectively; P = 0.06). In conclusion, the use of hepatic arterial dexamethasone is associated with an increased response rate and a trend toward increased survival and decreased bilirubin levels. Therefore, the authors recommend additional investigation of the use of dexamethasone with chemotherapy to treat hepatic metastases.
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PMID:A randomized trial of intrahepatic infusion of fluorodeoxyuridine with dexamethasone versus fluorodeoxyuridine alone in the treatment of metastatic colorectal cancer. 843 72

Small pieces of normal liver tissues were obtained from patients with gallstones undergoing cholecystectomy, and hepatocytes were isolated from these tissues. They were cultured in a medium of DFH containing several growth factors and hormones, successively for more than two years over 60 passages. They showed doubling time about 25 hours, peak mitotic index near 4% and heteroploid karyotype. They kept secreting some enzymes and albumin, that are usually produced by normal liver tissue. In contrast with hepatoma cells, the cultured normal hepatocytes failed to form xenograft tumor in nude mice and their proliferation was depended upon exogenous growth-factors in vitro. The cultured hepatocytes can be used as a cell model for study of carcinogenic process and stored as a cell-pool for clinical cell transplantation in the coming years.
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PMID:[Culture and characterization of normal human hepatocytes]. 130 11

Primary rat hepatocytes were transfected with simian virus 40 DNA and cultured in a chemically defined medium. Proliferating colonies developed after 2-3 weeks. Three cell lines were established by cloning albumin-secreting colonies, as identified by an immunooverlay assay. Two of the cell lines, ALB-6 and ALB-8, expressed all five liver-specific mRNAs studied, albumin, alpha-1-antitrypsin, fibrinogen, alpha-1-acid glycoprotein, and histidase. ALB-6 cells were nontumorigenic in nude mice while ALB-8 cells were weakly tumorigenic with only one of four injected nude mice developing a slowly growing tumor. Further transfection of ALB-6 and ALB-8 cells with an activated c-Ha-ras or N-ras oncogene resulted in strongly tumorigenic cells. The tumors induced by ras-transformed ALB-6 cells were moderately differentiated hepatocellular carcinomas. The tumors derived from ras-transformed ALB-8 cells were poorly differentiated, while the slowly growing tumors induced by untransfected or control DNA-transfected ALB-8 cells were well-differentiated trabecular hepatocellular carcinomas, suggesting histological dedifferentiation of cells following ras transformation. However, the synthetic capabilities of the cells were not lost in that the ras-transfected cultures and the tumors induced by ras-transformed cells retained the ability to synthesize the five liver-specific mRNAs. Thus we have developed an in vitro model of carcinogenesis in which, by sequential exposure to SV40 DNA and a ras oncogene, primary rat hepatocytes are transformed.
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PMID:ras transformation of simian virus 40-immortalized rat hepatocytes: an in vitro model of hepatocarcinogenesis. 130 23

Hepatocyte growth factor (HGF) is a potent mitogen for primary hepatocytes. Therefore, we examined HGF as a possible autocrine growth factor in hepatocellular carcinoma (HCC). We introduced an albumin-HGF expression vector into Fao HCC cells and transgenic mice. Expression of the albumin-HGF vector in Fao HCC cells inhibited their growth in vitro. In vivo, FaoHGF cells produced tumors that averaged 10% of the sizes of G418-resistant controls when transplanted into nude mice. In contrast, hepatocytes from transgenic mice expressing HGF grew more rapidly than did those from normal siblings. Further, growth of eight additional HCC cell lines was inhibited by the addition of recombinant HGF. Finally, of 35 tumor cell lines surveyed, only 6 cell lines expressed HGF mRNA, and no HCC cell line expressed HGF. Although HGF stimulates normal hepatocytes, it is a negative growth regulator for HCC cells.
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PMID:Hepatocyte growth factor inhibits growth of hepatocellular carcinoma cells. 130 12


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