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

Spontaneous reticulum cell sarcoma in SJL/J mice has been proposed as an animal tumor model for Hodgkin's lymphoma. The relationship of tumor progression and immune function is not clear, however, and has prompted a systematic evaluation of SJL/J immune competence. It was found that the ability to generate cell-mediated immunity and antibody response to allografts was not impaired in 2- to 12-month-old mice, regardless of their tumor status. All animals were capable of generating in vivo cytotoxic effector T-cells and both IgG and IgM classes of cytotoxic antibody to a tumor allograft. In addition to being able to respond, older mice showed an unexpected hyperresponsiveness to alloantigens, which suggested that escape from feedback control might be a characteristic of SJL/J mice. Loss of immune regulation was further indicated by the failure to induce tolerance to human gamma-globulin in mice 4 months and older, while 3-week-old SJL/J mice could be rendered unresponsive. Coincident with this apparent loss of regulation, circulating antibodies to synthetic double-stranded RNA, polyinosinis - polycytidylic acid, were first detected in unimmunized mice at 4 months of age, and titers remained elevated regardless of tumor status. It is suggested that tumor development as well as autoimmunity may result from an effective amplification of the immune response.
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PMID:Immune functions characteristic of SJL/J mice and their association with age and spontaneous reticulum cell sarcoma. 76 61

This study assess the effects of oral BCG, as a single agent, on tumor progression and on cell-mediated immune function in patients with metastatic malignant melanoma. Thirty patients were studied including 22 with measurable metastatic lesions and 8 with no detectable disease, following treatment of metastases by surgery, radiotherapy, or 5-(3, 3-dimethyl-1 -triazeno)-imidazole-4-carboxamide (DTIC; DIC). Oral BCG was given in doses of 120--240 mg, 1--3 times per week for periods ranging from 9 to 80 weeks and to total doses of from 1.2 to 20.1 gm. Patients were assessed by direct measurements of tumor mass, PPD skin test and in vitro blastogenic responses to PPD PHA. Of the 22 patient with measureable disease, 19 showed tumor progression and none showed regression of any lesion. Of the 8 without apparent disease, 5 remained stable and 3 had tumor recurrence. Of the total group of 30 patients, 8 showed some increased sensitivity to skin testing with PPD. Of 19 tested, 3 showed an increased PPD response in vitro, while 3 showed a decreased response. Six of 20 tested showed an increased PHA response in vitro. Oral BCG alone was not effective as an antitumor agent in patients with metastatic malignant melanoma.
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PMID:The use of oral BCG in the treatment or metastatic malignant melanoma. 78 99

The peroxidase and estradiol-metabolizing activities of mammary tumors induced by 7,12-dimethylbenz(a)anthracene were determined in fresh and stored tissue. In both cases, a wide variation in peroxidase activity was observed in 47 different tumors tested. The properties of the enzyme found in the tumors were similar to those of lactoperoxidase. It is suggested that the amount of peroxidase present might reflect the ability of tumor cells to differentiate in response to hormonal stimulation and be indicative of the degree of tumor progression.
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PMID:Metabolism of (4-14C)estradiol by 7,12-dimethylbenz(a) anthracene-induced mammary tumor peroxidase. 81 11

Six intracarotid artery infusions of DTIC were performed in 4 patients with invasive malignant melanoma of the maxillo-facial region. A total dose of 3.5 to 7 g was well tolerated. Only 1 patient who received 9.5 g in 25 days developed a reversible bone marrow depletion. Two out of the 4 patients presented a transient 50% tumor surface regression, but no response was seen after the second infusion. Of the 2 remaining patients, 1 had no measurable effect and 1 experienced tumor progression.
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PMID:Regional chemotherapy of maxillofacial malignant melanoma with intracarotid artery infusion of DTIC. 89 97

Mouse DNA and DNA of Ehrlich ascites tumor have been comparatively studied in the search for changes in DNA during tumor progression. No differences were found in kinetics of homologous (mouse X mouse) and heterologous (mouse X tumor) DNA reassociation; in thermal stability of homologous and heterologous duplexes of repeated, unique and satellite DNA; in percentage of hybridization with mouse liver heterogenous nuclear RNA; in thermal stability of the RNA.DNA hybrids. The negative results suggest that the considerable evolution of transplantable tumors (both in biological properties and in karyotype) has not been accompanied by alterations of the genome which could be detected by the now available methods of molecular hybridization for studying DNA divergence. In the light of the results obtained the functions ascribed to the mouse satellite DNA are discussed.
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PMID:Comparative investigation of DNA from mouse and Ehrlich ascites tumor cells. 92 7

CCNU (1-[2-chloroethyl]-3-cyclohexyl-1-nitrosourea, NSC-79037) was used to treat advanced malignancies in 329 evaluable patients. The treatment dosage was 130 mg/m2 for patients with adequate bone marrow reserve and 100 mg/m2 for those with compromised bone marrow. Oral treatment was repeated at 6-week intervals unless hematologic toxicity intervened. There were four complete responses: two in ovarian cancer, one with small cell carcinoma of the lung, and one with melanoma. Tumor response greater than 50% reduction in tumor size occurred in 39 patients (11.9%) while stable disease (no change or decrease or increase of less than 50% in tumor size) was noted in 152 patients (46.2%). Tumor progression occurred in 130 cases. Melanomas and ovarian and lung cancers had the highest response rates. Bone marrow depression was the major side effect of treatment; there was a significant positive correlation between the severity of leukopenia and thrombocytopenia and tumor response to treatment.
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PMID:Treatment of advanced malignancy with CCNU (NSC 79037): a phase II cooperative study with long-term follow up. 95 55

It is proposed that most neoplasms arise from a single cell of origin, and tumor progression results from acquired genetic variability within the original clone allowing sequential selection of more aggressive sublines. Tumor cell populations are apparently more genetically unstable than normal cells, perhaps from activation of specific gene loci in the neoplasm, continued presence of carcinogen, or even nutritional deficiencies within the tumor. The acquired genetic insta0ility and associated selection process, most readily recognized cytogenetically, results in advanced human malignancies being highly individual karyotypically and biologically. Hence, each patient's cancer may require individual specific therapy, and even this may be thwarted by emergence of a genetically variant subline resistant to the treatment. More research should be directed toward understanding and controlling the evolutionary process in tumors before it reaches the late stage usually seen in clinical cancer.
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PMID:The clonal evolution of tumor cell populations. 95 40

Advances in radiation techniques and increased dosage have improved the cure rate of patients with cancer of the cervix to 65 percent. Associated with this increased dosage (betatron, 5,250 r and intracavitary 137-cesium, 4,000 r at point A) has been a serious complication incidence of 10 percent. Major intestinal complications usually become manifest within an 8 to 24 month period following radiation. Few are associated with tumor and the majority are amenable to surgical correction. Rectosigmoid stenosis is a common and frequently unrecognized complication. The 8 to 12 cm. segment of rectosigmoid, with its rigid wall and narrowed lumen, can be recognized on barium examination. The symptoms are those on incomplete obstruction and deterioration, frequently confused with tumor progression. Thirty-one patients have been treated by resection and low anterior anastomosis with relief of symptoms. Rectosigmoid stenosis progressing to necrosis, perforation, or fistula (an additional 29 patients) is treated best by the Hartmann operation as a first stage. This procedure has been less complicated than either colostomy alone or resection and anastomosis. Fifteen patients with low level rectovaginal fistula or stenosis were treated by defunctioning sigmoid colostomy. A loop transverse colostomy was unsatisfactory. Ileorectovaginal fistulas occurred in an additional six patients. Preoperative investigation should establish the presence or absence of an ileal component in all fistulas. Radiation ileitis is rare as an isolated finding but frequently is associated with severe rectosigmoid damage. Surgical treatment is seldom necessary but, if indicated (ten patients), resection appears to be preferable to bypass.
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PMID:Radiation injuries to the bowel associated with the treatment of carcinoma of the cervix. 96 30

Melanoma cells carry membrane-bound antigens that induced both antibody production and cellular immunity. However, these antigens appear not to be tumor-specific, as the activity of human antisera can be absorbed out by fetal antigens. Nonetheless, the phenomenon of spontaneous regression, though mostly affecting only parts of a lesion, indicates that effective attack mechanisms do exist. Simultaneous tumor progression is due to heterogeneity of tumor cells, which vary widely in antigen expression. Cells that are not recognizable sneak through defense mechanisms and produce metastases.
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PMID:[Immunology of malignant melanoma (author's transl)]. 99 70

The given data indicate the presence of a negative correlation between metabolic indices (a decrease of the tolerance to glucose, increase of the blood level of free fatty acids, insulin, cholesterol triglycerides, cortisol, stc) and the indices of cellular immunity, which is determined by the number of rosette-forming cells and blasttransformation reaction to PHA and skin tests. Accordingly, the administration of an antidiabetic drug-phenformin (phenetylbiguanide)--apart from the improvement of metabolic pattern, results in the restoration of the cell-mediated immunity indices. These findings provide a basis for stating the phenomenon of metabolic immunodepression. The metabolic immunodepression may be supposed to prevent immunological surveillance activation, which normally is realized through the signals, provided by cells subjected to somatic mutation. It is noteworthy that the given metabolic conditions (hypercholesterinemia, hyperinsulinemia, the enhanced utilization of free fatty acids) promote the division of somatic cells. Thus, the same metabolic shifts which increase the pull of proliferating cells and, accordingly, increase the possibility of mutation development, also cause the metabolic immunodepression at the same time. These opposite metabolic influences on somatic cells and T-dependent lymphocytes cause the development of the syndrome of cancrophilia. The syndrome of cancrophilia normally arises at pregnancy, in intensive growth of the organism in childhood, accelerated development, stress and during normal ageing. Many carcinogens cause the decrease of tolerance to glucose, the increase in blood-insulin level and elevation of the threshold of sensitivity of the hypothalamus to feedback suppression. This phenomenon is based on the decrease of catecholamine level in thehypothalamus in ageing, stress and the action of some carcinogens. Thus, the syndrome of cacrophilia provides the conditions for cancer development and tumor progression, besides, the tumor itself produces the metabolic shifts typical of cancrophilia. In the light of mutation-metabolic model of cancer development, it is possible to consider the fundamental factors which increase of hinder carcinogenesis.
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PMID:[Mutational-metabolic model of carcinogenesis and the progression of the neoplastic process]. 99 16


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