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

A new model is presented for the study of the effects of supranormal temperatures on human tumors in vivo. Human tumors heterotransplanted serially in nude mice were heated in vivo by means of local radio-frequency heating. A lung carcinoma, a breast carcinoma, a colon carcinoma, and a malignant melanoma were studied. The tumors were transplanted s.c. in the inguinal area or under the kidney capsule of adult nude mice. The s.c. tumors were heated for 30 min. Temperatures of 43--44 degrees C were reached in the surrounding normal tissues, whereas in the center of the tumor temperatures of 46--49 degrees C were recorded. In 11 of 16 randomized pairs of mice, the growth of the tumor treated by hyperthermia was inhibited by 75% or more as compared with the growth of the untreated tumor control. No mortality and only temporary damage to skin and muscle were observed. The kidney tumors were also treated for 30 min, but it was possible to reach only 40 degrees C in the abdomen. Seventy-five % mortality was observed. Of seven randomized pairs evaluated, five exhibited a reduction of growth varying from 37 to 63%9 The model proposed appears to be a workable and promising one, especially for s.c. growing tumors.
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PMID:Hyperthermic treatment of human tumors heterotransplanted in nude mice. 44 23

The chemotherapeutic activity of thymidine (dThd) was tested against four human tumor xenografts growing in nude mice, including a melanoma, an oat cell carcinoma of the lung, a colon carcinoma, and a breast carcinoma. Tumor-bearing mice were given an infusion of dThd (1 g/kg/day) s.c. for 72 hr each week for three weeks. Tumor growth in the treated mice was compared to that in randomized concurrent control mice infused with media alone. A significant effect was found only for the melanoma, and it was cytostatic rather than cytotoxic. Even when melanomas of very small initial volume were treated, there were no complete regressions, and tumor growth resumed when dThd treatment was stopped. In culture, sustained dThd concentrations of greater than 3.2 mM were required to cause death of the melanoma cells; in the mice the dThd level during infusion ranged from 1 to 5 mM. This exposure to dThd, although failing to produce a tumor response, did produce significant toxicity in the nude mice in the form of myelosuppression and leukopenia. Flow cytometric analysis of marrow cells during the dThd infusion showed an accumulation of cells in S phase, but proliferation was not completely halted since cells with G2-M content of DNA were present in the marrow even after 72 hr of dThd exposure. This study failed to demonstrate a therapeutically useful effect of dThd on these tumors.
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PMID:Activity of thymidine as a chemotherapeutic agent against human tumor xenografts in nude mice. 47 23

Human interferon decreased DNA but not RNA synthesis in a human colon carcinoma cell line, WiDr; in addition, there was a two- to three-fold increase in the expression of a tumor-associated antigen, carcinoembryonic antigen. In contrast, interferon had no effect on a normal human diploid cell line, WI-38. Thus, in addition to its anti-cellular effect against tumor cells, interferon can also modulate tumor antigenicity.
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PMID:Enhancement of carcinoembryonic antigen expression by interferon. 47 91

The sensitivity to local tumor hyperthermia (43 degrees, 60 min) of a spectrum of eight different solid mouse tumors (Lewis lung carcinoma, M5076 ovarian carcinoma, colon carcinoma 38, colon carcinoma 26, mammary adenocarcinoma C3HBA, mammary adenocarcinoma 16C, glioma 26, and B16 melanoma) was investigated. A microwave (2.45-GHz) apparatus produced localized heating of the tumors without generation of whole-body hyperthermia. The temperature at the center of the heated tumors was regulated to within +/- 0.1 degrees while the temperature uniformity within the tumor was +/- 0.5 degrees. The local hyperthermia treatments reduced the size and retarded the growth of the treated tumors compared with control values for each of the tumors tested. The faster-growing Lewis lung carcinoma and B16 melanoma were the least responsive to treatment, while the slower-growing colon 38 and M5076 ovarian carcinomas were the most responsive. Multiple treatments resulted in longer grwoth delays and greater tumor growth inhibition than did single treatments. No consistent difference in life span between the control and treated groups was measured, and only five of 188 treated animals were cured.
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PMID:Effects of local tumor hyperthermia on the growth of solid mouse tumors. 49 85

Two human colon carcinoma cell lines derived from the same tumor specimen were characterized. The cell lines, COLO 320 and COLO 321, have amine precursor uptake and decarboxylation cell properties, such as ectopic production of norepinephrine, epinephrine, serotonin, adrenocorticotropic hormone, and parathyroid hormone. The cells were morphologically different from most colon cell lines. Double minutes (DM) were initially present in nearly 100% of the metaphases. In a few subcultures of COLO 320, DM have persisted for 1.5 years. However, in COLO 321 and some subcultures of COLO 320, a loss of DM was observed and new marker chromosomes with homogeneously staining regions were observed. These unusual cell lines should be valuable for studies of apudomas of the colon and the cytogenetic phenomena of DM and homogeneously staining regions.
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PMID:Cell lines from human colon carcinoma with unusual cell products, double minutes, and homogeneously staining regions. 49 17

Antibody-dependent cell-mediated cytotoxicity (ADCC) against human colon carcinoma cells grown in vitro was demonstrated with two specific rabbit anti-carcinoembryonic antigen (cea) antisera. The same antisera did not lyse the colon carcinoma cells in the presence of complement but without lymphocytes. The normal human lymphocytes in the absence of anti-CEA antiserum had a very low cytotoxic activity during the three hours 51Cr release assay used in this study. Two colon carcinoma cell lines, HT-29 and Co-115, expressing CEA on their surface as demonstrated by immunofluorescence, were significantly lysed in the ADCC test, whereas control tumor cell lines, not expressing CEA, were not affected by the anti-CEA sera and the lymphocytes. The specificity of the reaction was further demonstrated by the inhibition of antibody-dependent cell-mediated cytotoxicity after the addition of increasing amounts of purified CEA to the antiserum. The absorption of the anti-CEA antisera was controlled by radioimmunoassay. Absorption of the antisera by normal lung extracts and red cells of different blood groups did not decrease the cytotoxicity.
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PMID:[Antiserums against carcino-embryonic antigen (CEA) can induce a specific lysis of colon carcinoma cells by normal lymphocytes]. 56 64

Male F344 rats, 8 weeks of age, were given 16 intrarectal administrations of N-methyl-N-nitrosourea (NMU) at one of three dose levels over a period of 8 weeks. Five days after the final NMU instillation, rats were placed on one of three diets: chow with gelatin beadlets, chow with beadlets containing 0.024% 13-cis-retinoic acid, or chow and beadlets with 0.006% of the trimethylmethoxy phenyl analog of retinoic acid ethylamide. Groups of 20-40 rats were killed at 22-26 weeks after the first carcinogen treatment. The number of rats with colon carcinoma and the number of tumors per rat were dose related. In addition, "blind" histopathologic evaluation of four predesignate colon locations revealed a dose-related incidence of microscopic preinvasive and invasive colon carcinomas. The feeding of diets containing these two retinoids did not significantly alter the incidence of these parameters of carcinogenesis or the mean histopathologic score at predesignated colon locations for preinvasive or invasive neoplastic lesions. Over 90% of the colon neoplasms induced were invasive tubulopapillary adenocarcinomas. The diameters of the tumors correlated significantly with degrees of invasion of the colons. Only 1 tumor (a signet ring carcinoma) metastasized to the peritoneal cavity. Only 2 of 300 rats treated with NMU had tumors at sites other than the colon.
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PMID:Dose response to intrarectal administration of N-methyl-N-nitrosourea and histopathologic evaluation of the effect of two retinoids on colon lesions induced in rats. 65 Jul 11

The DNA alkaline elution technique provides a sensitive assay for the effects of DNA-damaging drugs in mammalian cells. We have adapted this method to permit measurements of effects on DNA in solid tumors. Human colon carcinoma xenografts in nude mice were treated with a single i.p. injection of 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea, and the effects on the DNA were followed for 19 hr. Drug doses in the pharmacological range produced significant reductions in DNA alkaline elution rates in assays in which X-ray was used to introduce a standard frequency of single-strand breaks. These changes in alkaline elution rate were attribute to the production of both DNA interstrand and DNA-protein cross-links, which were distinguished from each other on the basis of the extent to which the effect on elution could be reversed by proteinase K. Crosslinking increased for about 8 hr after treatment with little change thereafter up to 19 hr. A drug-resistant tumor line exhibited substantially less cross-linking than did a drug-sensitive line at all time points examined.
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PMID:DNA cross-linking by in vivo treatment with 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea of sensitive and resistant human colon carcinoma xenograms in nude mice. 66 42

The growth characteristics and metastatic behavior of human tumors growing in athymic nude mice were studied. Human tumor cell lines HEp-2 (carcinoma or larynx) and SW480 (colon carcinoma) were transplanted into athymic nude mice of BALB/c origin. Tumor cells (1 x 10(6) and 2 x 10(7)) were given either s.c. or i.p. Following s.c. injection tumors developed rapidly to become easily palpable with 2 weeks forming a s.c. tumor focus surrounded by a thick fibrous capsule. Animals with s.c. transplants were little affected by the growing tumor. At the time they were sacrificed at Day 34 (HEp-2) and 62 (SW480), a large part of the tumor was necrotic. Capsular infiltration and invasion of lymphatic vessels and perineural and perivascular lymphatic spaces were observed. Metastases to regional lymph nodes were seen in animals kept alive for up to 6 months. Following i.p. transplantation, tumors spread widely in the peritoneal cavity, invaded intraabdominal organs, and metastasized to mediastinal lymph nodes and lungs. Fifteen of 26 animals (60%) developed metastases. Necrosis of the i.p. growing tumors was minimal. All animals in this group died as a result of tumor growth.
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PMID:Growth patterns and metastatic behavior of human tumors growing in athymic mice. 68 9

With the paired-labeled antibody technique, the in vivo localization of radioiodinate, affinity-purified antibody to carcinoembryonic antigen (CEA) was studied in GW-39, a xenografted, CEA-producing tumor model. When compared to the whole immunoglobulin G fraction, a 4-fold greater tumor accumulation of radioantibody was obtained with affinity-purified specific CEA antibody. The degree of increased tumor localization of affinity-purified antibody was similar to its improved immunoreactivity as observed in radioimmunoassay and binding to CEA immunoadsorbent. Affinity-purified antibody cross-reactive with CEA and colon carcinoma antigen III was as equally effective in tumor localization as was specific CEA antibody prepared similarly. It thus appears that affinity-purified CEA radioantibody will provide a superior tumor-imaging agent for clinical use.
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PMID:Localization of GW-39 human tumors in hamsters by affinity-purified antibody to carcinoembryonic antigen. 85 62


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