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

Immunological endeavor in recent years calls for a reappraisal of the concept of immunosurveillance against neoplasia. This concept proposes an immunological policing system capable of aborting tumor growth by the recognition of "nonself" tumor associated antigens on neoplastic cells. The model is supported by evidence of tumor induction in the immunosuppressed host and the demonstration of an immune response to tumors in animals. The occurrence of tumor, regarded as a failure of immunosurveillance, is attributed to selection of neoplastic cells for immunological or other reasons or abnormal humoral or cellular antitumor immune responses. However protagonists of the postulate are faced with mounting evidence that fails to support the surveillance hypothesis. These observations include, inter alia, the monoclonality of certain tumors, the low incidence of spontaneous tumors in genetically immunodeficient mice and immunological privileged sites, and new ideas about the pathogenesis of lymphoproliferative neoplasms. However, contradictory arguments are not sufficiently substantiated to prosecute the case against surveillance conclusively. In citing highlights of the evolving quandary, both the pros and cons of immunological surveillance are presented here.
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PMID:Immunological surveillance against neoplasia: an immunological quandary. 10 13

Parenteral and enteral nutrition are being used as adjuncts to cancer therapy. A liquid diet formulation containing a 27% solution of glucose and 3.9% crystalline amino acids with electrolytes and vitamins was given continuously for a week via parenteral (iv), and via intragastric (ig) routes and also was given ad libitum via the oral or per os (po) route to groups of Buffalo rats with and without a Morris No. 7777 transplantable hepatoma to find out how these feeding procedures affect tumor-host interactions. Other groups of rats with and without the hepatoma were given solid food ad libitum. The following parameters were examined: mortality, carcass and organ weights, body and tumor growth, nitrogen balance, energy intake, fluid balance, urinalysis, hematology values, and serum protein levels. The results are considered with respect to the influence of the tumor on the host and the influence of the feeding procedure on the animal with and without a tumor. The presence of the hepatoma was associated with: higher mortality, a decrease in carcass mass, leucocytosis, anemia, a decrease in serum IgG, transferrin and albumin, and an increase in serum alpha fetoprotein. The iv and ig feeding procedures alone resulted in some mortality which was exacerbated by the presence of the tumor. Mortality was especially high in the tumorous rats on the ig feeding procedure. The degree of positive nitrogen balance and carcass mass was similar in non-tumorous rats fed the same liquid diet formula when given iv, ig, or po. Tumorous rats fed the liquid diet ad libitum showed anorexia and a significantly lower nitrogen balance. The iv and ig feeding of tumorous rats at a level which was well above those of the tumorous rats given solid or liquid diet ad libitum maintained the same degree of positive nitrogen balance as non-tumorous rats. Even though the iv feeding of tumorous rats maintained about the same degree of positive nitrogen balance as non-tumorous rats, these tumorous rats still suffered loss of carcass mass. It appears that the large rapidly growing hepatoma has priority for available nutrition over the host. It is further suggested that the rapidly growing hepatoma places an ever increasing demand on the available nutrients. Thus, a point is eventually reached where even supplemental nutritional support can no longer meet the needs of the growing hepatoma and the host.
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PMID:Tumor-host responses to various nutritional feeding procedures in rats. 10 99

Provision of adequate nutrition makes a major contribution toward improvement of clinical, biochemical, cellular, and psychologic status of the cancer patient in the face of the disease process and the side effects of various treatments. The principles of nutrition support include the following: 1) Malnutrition induced by cancer and its treatment adversely affects the patient and complicates further treatment of the disease. 2) Malnutrition is not an obligatory response of the host to cancer. 3) A rational nutritional therapeutic program for a patient requires analysis of the factors inducing depletion in that patient. 4) Every patient should have an early and periodic assessment of nutritional status. 5) Nutrition therapy, when indicated, should be instituted early. 6) The application and effectiveness of therapeutic programs must become part of the medical audit and general clinical procedure for inpatients and outpatients. 7) The objectives of nutritional therapy are: a) supportive, b) adjunctive, and c) definitive. 8) Nutritional status, tumor growth and anti-tumor treatment are intimately related. 9) Nutritional therapy has the potential for difficulties as well as benefits. 10) The provision of optimal nutrition care requires a multidisciplinary approach with physicians, nurses, dietitians, and pharmacists working as a team with adequate laboratory facilities and administrative and financial support.
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PMID:Principles of nutritional therapy. 10 85

In over 1000 cancer patients treated with intravenous hyperalimentation (IVH), tumor growth has not been identified and catheter-related sepsis has been minimal. Studies in rats demonstrated that the host benefits more than the tumor during nutritional repletion, and any stimulation of tumor growth in the rat-tumor model could be manipulated with DNA specific drugs to benefit the host. A study of 65 malnourished cancer patients undergoing oncologic therapy and treated with IVH indicated that much of the immune suppression in these patients was the result of malnutrition coincident with or secondary to oncologic treatment. Conclusions reached in this study were that nutritional repletion resulted in a return of skin test reactivity, proper wound healing in the surgical patient, and possibly an increase in response to chemotherapy. Certainly, the use of IVH allowed specific oncologic therapy to be administered to a group of malnourished patients who otherwise might not have been acceptable candidates for intensive antineoplastic therapy.
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PMID:Nutrition, cancer, and intravenous hyperalimentation. 10 87

Collagen synthesis is increased over three-fold in capsules surrounding dimethylbenzanthracene-induced rat breast tumors compared to the tumor parenchyma and over six-fold compared to normal breast connective tissue. Increased collagen synthesis is independent of the rate of tumor growth and final tumor size. Pretreatment of animals with beta-aminopropionitrile to inhibit collagen cross-linking caused an 82% decrease in tumor formation and a significant reduction in tumor volume (approximately 0.4 cu cm) compared to controls (approximately 10 cu cm). The four small tumors that did develop in the lathyritic animals had increased collagen synthesis in the interior tumor stroma and reduced collagen synthesis in the tumor capsule. These findings suggest that the collagenous capsule surrounding dimethylbenzanthracene tumors functions as a physical barrier to protect the tumor from the immune system of the host. The apparent antitumor effects of beta-aminopropionitrile may be due to immunopotentiation and/or cytotoxic actions of the drug.
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PMID:Collagen synthesis in capsules surrounding dimethylbenzanthracene-induced rat breast tumors and the effect of pretreatment with beta-aminopropionitrile. 11 Apr 42

Hamster cheek pouches were sensitized with the potent allergen DNCB either before the initiation of DMBA tumorigenesis or by direct application to already developed tumors. Among animals treated prior to tumorigenesis induction there was an apparent delay in onset of tumors and decreased rate of tumor growth. Direct application of DNCB to already established tumors seemed to temporarily arrest tumor growth; later, however, tumor growth rate resumed to approximately that in untreated control animals. It is concluded that DNCB contact hypersensitivity may exert some influence on the DMBA tumorigenesis process as manifested by delay in tumor onset or by temporarily retarding growth of established tumors. It appears that DNCB sensitization prior to tumorigenesis is generally more effective than DNCB applied after tumor development.
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PMID:Immunologic manipulation of DMBA tumorigenesis in hamster cheek pouch by DNCB contact hypersensitivity. 11 30

Rats bearing the Morris hepatoma No. 7777 were randomized into three treatment groups. Two of the groups received a nutritionally complete liquid formula diet per os ad libitum. One of these two groups received hydrazine sulfate (HS; an inhibitor of gluconeogenesis) twice daily (15 mg/kg) for 5 days. A third group of tumorous rats received the HS therapy and was given the liquid diet parenterally for 5 days. Tumorous rats fed per os, especially with HS therapy demonstrated inhibition of tumor growth, reduction of body and carcass weight, anorexia and decreased nitrogen retention. The combination of parenteral feeding and HS therapy sustained body and carcass weight with high nitrogen retention but stimulated tumor growth and was associated with liver toxicity. These results support the concept that cancer cachexia involves 'a systemic energy-losing cycle dependent on an interplay of tumor glycolysis and gluconeogenesis'.
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PMID:Total parenteral nutrition and inhibition of gluconeogenesis on tumor-host responses. 11 15

The effect of 1,3,5(10)-estratriene-3, 16 alpha, 17 beta-triol (estriol), 1, 3, 5(10)-estratriene-2,3-diol-17-one (2-hydroxyestrone), and 1,3,5(10)-estratriene-2,3,17 beta-triol (2-hydroxyestradiol) on the growth of dimethylbenz(a)anthracene-induced mammary tumor and of R3230AC-transplantable mammary tumor was compared with that produced by estradiol benzoate treatment. Estriol showed minimal inhibition of tumor growth in dimethylbenz(a)anthracene-induced tumor and no effect on R3230AC tumor while 2-hydroxyestrone showed no effect of tumor inhibition. On the other hand, 2-hydroxyestradiol showed appreciable inhibition of tumor growth in both tumors studied. That 2-hydroxyestradiol has been found to bind to estrogen receptors in mammary tumors and is uterotropic suggests that the inhibition of tumor growth by 2-hydroxyestradiol may be similar to the mechanism of inhibition of mammary tumors by high concentrations of estradiol.
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PMID:Effect of catechol estrogens on rat mammary tumors. 11 83

The immunogenicity of a series of mouse tumor lines propagated in vivo (T and B lymphomas and mammary adenocarcinoma) was tested after alteration of the cell membrane-lipid microviscosity. Tumor cells used for immunization were first treated to alter the lipid content, then irradiated and injected intraperitoneally into syngeneic mice. A second identical immunization was performed 14 days later. The degree of immunization in the treated mice was assessed by survival time after challenge with untreated viable tumor cells of the same origin as the immunizing cells. For all tumors tested, enrichment of the immunizing cells with cholesterol or cholesteryl hemisuccinate, which increased the membrane-lipid microviscosity significantly, afforded a marked increase in immunization, compared to that obtained with cells that were only irradiated. Furthermore, in over 90% of the mice that were pretreated with cholesteryl hemisuccinate-enriched cells, tumor growth after the challenge was not detectable. Because the lipid-modifying treatments of the immunizing cells involve no toxic substances, these results may provide the basis for a potent approach to immunotherapy of human cancer.
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PMID:Effective tumor immunization induced by cells of elevated membrane-lipid microviscosity. 11 28

A radio (51Cr) micro-tube leukocyte adherence inhibition assay is described. In this study, murine mononuclear cells were labeled with 51Cr, plated into tissue culture plates with different tumor extracts and counts/min (cpm) of the non-adherent cells were used as a parameter of adherence inhibition. This assay was used to measure anti-tumor immunity, in vitro, in 3 murine tumor systems: MCA-38 colon adenocarcinoma, L1210 lymphoma and P815 mastocytoma. Tumor immunity was detected using 3 doses (0.01-0.001 mg/ml) of tumor extract in the MCA-38 tumor model, and using 2 doses (0.1-0.05 mg/ml) of tumor extract in both the L1210 and P815 tumor models. It was observed that specific tumor-associated adherence inhibition could be measured in the MCA-38 tumor model between days 7 and 22 of tumor growth and in the L1210 and P815 tumor models between days 7 and 17 of tumor growth. The radio-LAI assay described is an easy, specific and reproducible way to measure tumor-associated adherence inhibition, in vitro.
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PMID:A radio (51Cr) micro-tube leukocyte adherence inhibition assay: specific tumor-associated immunity in 3 murine tumor systems. 11 17


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