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

The effect of hyperthermia on normal and tumor tissue was studied following water bath heating of a methylcholanthrene-induced fibrosarcoma (FSaI) isotransplanted into the feet of C3H mice. The time-temperature relation for the 50% tumor control dose over the temperature range of 41.5--45.5 degrees showed a log linear relationship which followed a biphasically modified Arrhenius plot. At temperatures above 43 degrees, there was a 50% reduction in heating time to obtain the 50% tumor control dose for each 1 degree increase in temperature, corresponding to an activation energy of 140 kcal/mol. At temperatures below 43 degrees, the curve was steeper, with a tendency to double the treatment time for each 0.5 degree reduction in temperature (activation energy, approximately 230kcal/mol). Normal tissue damage in the tumor-bearing foot was estimated at two levels with a 50% response dose assay. Severe normal tissue damage showed a time-temperature relationship similar to the tumor response, thus indicating no variation in therapeutic ratio at different temperatures. However, for slight tissue damage, the therapeutic ratio increased with decreasing temperatures, yielding a better therapeutic ratio at lower temperatures. The time-temperature relationship obtained in the FSaI fibrosarcoma is supported by other studies and points to a general time-temperature relationship for hyperthermic tumor destruction.
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PMID:Time-temperature relationship th hyperthermic treatment of malignant and normal tissue in vivo. 45 7

Synergistic muscles (soleus and plantaris) from a gastrocnemius-tenotomized hindlimb were compared to the same muscles in a sham-operated hindlimb in both tumor-bearing and non tumor-bearing rats. In nontumor-bearing animals muscle from the tenotomized hindlimb had a significant increase in wet weight (26%), percent-water (5%), and total nitrogen/muscle (10%) consistent with muscular hypertrophy. In tumor-bearing animals, muscle from the tenotomized hindlimb had a significant increase in wet weight and percent water, but there was no significant difference in total nitrogen/muscle. As the tumor burden increased, the final muscle weight, in both the tenotomized and sham-operated hindlimb, was found to decrease proportionately. Only in animals with large (23% body wt) tumor burdens did hypertrophied muscle weigh significantly less than sham-operated muscle from nontumor-bearing animals. This indicated that, in rats with large tumor burdens, work-induced hypertrophy was unable to preserve muscle mass despite the fact that hypertrophied muscle was 24% heavier than contralateral sham-operated muscle.
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PMID:Effect of work-induced hypertrophy on skeletal muscle of tumor- and nontumor-bearing rats. 45 41

Two cases of papillary carcinoma of the bladder are presented in which the ureter could not be demonstrated by standard radiographic techniques. Computed tomography (CT) allowed identification of the tumor filled ureter. Intraureteral papillary tumor has a radiographic density (CT number) above that of water but less than that of the enveloping ureter.
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PMID:Intraureteral tumor demonstrated by computed tomography. 45 60

Gangliosides, cholesterol, and phospholipids were quantitated in the tissues of 11 human neural tumors and the cells of two gliomas cultured in vitro. All tumor tissues contained higher water concentrations but lower total lipid concentrations than either human grey or white matter. In general they contained less cholesterol, sphingomyelin, and serine glycerophospholipid but more choline glycerophospholipid than white matter. Concentrations of total ganglioside sialic acid were intermediate between grey and white matter. Compared with normal brain, all tumors had greater proportions of the structurally less complex gangliosides and smaller proportions of the more complex gangliosides. This was most marked in the rapidly growing tumors while the better differentiated astrocytomas contained the greatest proportions of complex gangliosides. The cells of the cultured tumors contained amounts of total lipid and total phospholipid similar to their parent tissues. However, the cultures had less cholesterol, sphingomyelin, and total ganglioside than their parent tissues. There were significant amounts of choline and ethanolamine plasmalogens in both cultures and parent tissues. The ganglioside patterns of both cultures were complex but they contained a greater proportion of structurally simpler gangliosides than their parent tissues.-Yates, A. J., D. K. Thompson, C. P. Boesel, C. Albrightson, and R. W. Hart. Lipid composition of human neural tumors.
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PMID:Lipid composition of human neural tumors. 45 65

The pulsed nuclear magnetic resonance technique was explored for its potential diagnostic value in human cancer. Measurements of proton spin-lattice relaxation times (T1) of cellular water protons of normal and malignant esophageal tissues showed elevated T1 values in the latter. In some cases, tissues which appeared normal on gross examination assumed as uninvolved tissues had T1 values higher than the other grossly uninvolved tissues and often closer to the T1 of the corresponding tumor tissue. A histopathological study of the assumed uninvolved areas also studied for the T1 values was therefore undertaken. A preliminary study demonstrated the presence of malignant cell groups or clusters in some of the uninvolved samples with higher T1 compared to the true uninvolved tissues, which had a normal histological picture and low T1 values. This observation has brought out the importance of histopathological studies in addition to relaxation studies to comprehend contributory factors to relaxation. Secondly, it lends support to the thesis of elevated T1 values being characteristics of the malignant state.
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PMID:Histopathological evidence in support of the association of elevated proton spin-lattice relaxation times with the malignant state. 46 67

Sodium nitrite has been widely used as one of the most effective food additives to tinge color on cured meat. However, it has been elucidated that this chemical is not merely a precursor of N-nitroso compounds, many of which are strongly carcinogenic, but also a mutagenic substance in biological tests. In order to ascertain the possible tumorigenicity of sodium nitrite itself, chronic toxicity of the agent in mice, by means of daily oral administration as drinking water for more than 18 months, in the concentration of 0.5 (maximum tolerated dose), 0.25, and 0.125%, was tested. As a result, development of various tumors, including thymic lymphoma, nonthymic lymphoid leukemia, pulmonary adenoma and carcinoma, and benign and malignant tumors in soft tissue, was seen in these mice. However, as to the incidence of tumors as well as the developmental time of each histologically classified tumor, no apparent difference was detected between those in the experimental groups and the control group.
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PMID:Chronic toxicity of sodium nitrite in mice, with reference to its tumorigenicity. 46 85

It was possible to produce gastric adenocarcinoma in five of 69, healthy, young albino mice of both sexes given N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in their drinking water at a concentration of 100 microgram/ml. The tumoral lesions were most clearly defined in the group that received MNNG for the longest period of time, that is, 68 weeks. On the other hand, in the rest of the groups, which received MNNG for fewer weeks, there were lesions found in a total of nine animals which consisted in foci of typical and atypical hyperplasia, erosion of the mucosa, and, in one animal, an adenomatous polyp. Contrary to findings in humans, intestinal metaplasia preceding or accompanying the neoplasia was found to be an inconsistent alteration and a not very frequent one.
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PMID:Production of proliferation lesions in gastric mucosa of albino mice by oral administration of N-methyl-N'-nitro-N-nitrosoguanidine. 46 96

Transplacental induction of lung tumor by 1-ethyl-1-nitrosourea (ENU) was studied in pregnant ddY mice which were given a single intraperitoneal injection of 58.5 mg/kg of ENU in water between day 13 and 19 of gestation. Within 4 approximately 6 weeks after birth, pulmonary tumor nodules were found in all offsprings exposed to ENU, and they were histopathologically adenoma. Number of tumor nodules could be counted under the stereomicroscope from approximately day 40 after birth. The size of tumor increased with the lapse of time but the number of tumor nodules did not increase markedly. Weekly injections of urethan or ENU into mice pretreated with ENU in their fetal age enhanced the number of pulmonary adenoma. The development of other tumor was not seen except a few cases of lymphoma. Tumor development in the lung by injection of ENU in ddY mice during gestation is reproducible, relatively simple, and rapid. Therefore, it is considered that this may be a useful method for screening of antitumor agent.
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PMID:Tumor development in lung of ddY mice following transplacental exposure to 1-ethyl-1-nitrosourea. 46 99

Hepatic tumors were induced in medakas (Oryzias latipes) by the addition of diethylnitrosamine (DEN) to their aquarium water. Medakas are useful for study because they are highly susceptible to the carcinogenic effect of DEN and the time for tumor induction is relatively short. Tumors had a histological pattern similar to that of mammalian hepatic tumors. The medaka seems to be susceptible to water-soluble carcinogens.
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PMID:Importance of hepatic neoplasms in lower vertebrate animals as a tool in cancer research. 46 53

Two cases illustrating the value of CT in the assessment of spinal dysraphic tissue are presented. In one case, the configuration and origins of two osseous diastematomyelic spurs were shown well; in the second case, the CT recognition of a sacral lipoma led to air myelographic confirmation of the tumor and tethered cord. CT phantom studies indicated that dysraphic tissues, such as fat, cartilage, and fibrous tissue, are better identified and quantitated in the spinal canal when surrounded by air. Varying degrees of image degradation occur with water (simulating CSF) or metrizamide.
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PMID:Computed tomography and spinal dysraphism: clinical and phantom studies. 47 Dec 18


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