Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cytotoxic action of lymphocytes on cancer cells in vitro indicates sensitization of the patient against his own tumor. The technical difficulities of this test and possibilities of standardization and simplifying the procedure are discussed. Critical steps are isolation of lymphocytes and culturing target cells without loosing their specific antigenic structure. The need for specificity controls both for lymphocytes and tumor cells is emphasized. Labelling tumor cells with isotopes represents a major improvement in evaluating the result. The role of thymus- and bone marrow-dependent lymphocytes as well as blocking factors in the serum of tumor patients can be analyzed in the cytotoxic assay. A better understanding of these mechanisms may facilitate a therapeutic approach by manipulating the interaction of tumor cells and host.
 ...
PMID:[The lymphocyte cytotoxicity test in tumor immunology (author's transl)]. 4 11

There is a need to establish the diagnosis of cancer of the larynx as early as possible. Delay in making the diagnosis should occur rarely if all of the available methods are fully utilized. Having established the presence of a carcinoma it should be possible to define the site and extent of the tumor; only with this additional information can the best treatment be selected. The use of a fiber-optic laryngoscope or a telescopic laryngoscope (Gould) has made examination of the "difficult larynx" more satisfactory. X-ray examination, with or without contrast material, has provided useful information regarding extent of the tumor, particularly with regard to its relation to the glottis. Microscopic laryngoscopy has proven to be a most reliable way to identifying "the early lesion" and of establishing the extent of an established tumor, especially if supravital staining is applied and the microsurgical laryngeal mirror and laryngeal caliper are used. The most difficult diagnosis to make at the present time is the presence of residual tumor after radiation, when the tumor does not present on the surface. The solution to this problem will not be found easily.
 ...
PMID:Diagnosis of carcinoma of the larynx: a review of current methods. 4 97

The results of molecular hybridization experiments with high-molecular-weight RNA isolated from RNA tumor viruses and DNA from normal cells suggest that RNA tumor virus genomes originate from cell genes. Some RNA tumor viruses (here called class 1) appear to have been generated in recent times in that their RNA is closely related in nucleotide sequence to certain cell genes (class 1 genes). A second class of RNA tumor viruses (here called class 2) is more distantly related to genomic information of normal cells. Structural properties of the RNA of RNA tumor viruses lead us to propose that the tumor virus RNA is originated when RNA transcripts of class 1 genes are processed by a mechanism we call "paraprocessing." We postulate that RNA paraprocessing is normally used only at particular times during differentiation and is characterized by the cytoplasmic appearance of high-molecular-weight RNA chains containing terminal polyadenylic acid (200 residues). Paraprocessing of class 1 gene transcripts in committed or differentiated cells is considered to be aberrant in transcription that can lead to the generation of an RNA tumor virus genome. If the paraprocessed class 1 gene transcript codes for a reverse transcriptase, replication of the RNA becomes possible. Transfer of the replicating RNA to a new cell can result in genetic change such that the virus genome mutates, differing from the original progenitor genes. We propose that this genetic change causes class 1 viruses to become class 2. These ideas are applied to evidence concerning the biology of infection of RNA tumor viruses and concerning the involvement of RNA tumor viruses in human cancer. Genetic change can also occur during the origination of an RNA tumor virus genome by repeated reverse transcription and recombination (45) or by genetic alteration of particularly changeable cell genes ("hot spots") (43).
 ...
PMID:RNA processing and RNA tumor virus origin and evolution. 4 50

The mechanism of neosynthesis of the human tumor-associated fetal antigen alpha-fetoprotein (AFP) in a variable percentage of patients with testicular, ovarian and extragonadal germ cell tumors has generally been considered unknown or beyond any simple explanation. Of decisive importance is the cellular basis for AFP production 1. in ontogenesis and 2. in malignancy as dependent on an exact tumor histogenesis. Based on (1) the histogenetic-embryologic classification of germ cell tumors and the concept of yolk sac tumor (or endodermal sinus tumor), (2) the available clinical and experimental observations, and (3) the immunofluorescent localization of AFP in the endodermal sinus tumor of the human testis, it is concluded that AFP synthesis in these neoplasms is explained by the fact that they contain yolk sac endoderm, which produce AFP analogous with the physiological AFP synthesis by the fetal yolk sac in early embryogenesis.
 ...
PMID:The histogenetic-embryologic basis for reappearance of alpha-fetoprotein in endodermal sinus tumors (yolk sac tumors) and teratomas. 4 95

Rabbits were immunized with extracts of primary or grafted intestinal adeno-carcinomas induced by carcinogenic drugs in inbred rats. After absorption with normal tissue extracts, the antisera were able to recognize three tumor-associated antigens. Two of them were glycoproteins, present in cancer cells but also, in trace amounts, in mucous cells of the normal digestive tract. The third antigen is not detectable in the normal digestive system, but present in normal spleen; on im-unofluorescence, it is not located in the cancer cells, but in polymorphonuclear cells infiltrating the tumor. None of the three antigens cross-reacts with human carcinoembryonic antigen, or human or rat alphafetoprotein. On the other hand, one of the glycoprotein antigens is immunologically related to the human blood group A substance.
Int J Cancer 1975 Jan 15
PMID:Antigens associated with chemically induced intestinal carcinomas of rats. 4 40

In vitro lymphocyte stimulation by mitomycin-C-blocked tumor cells has been used to demonstrate tumor-specific antigens in syngeneic murine systems and to follow the evolution of tumor immunity with the tumor-bearing state. Mitomycin-blocked tumor cells stimulated syngeneic lymphocytes from normal mice, from those bearing small tumors (less than 1 cm in diameter) and from tumor-immune mice, sensitized by tumor-cell inoculation and subsequent tumor removal, to undergo increased DNA synthesis as measured by the incorporation of tritiated thymidine. However, lymph-node cells from mice bearing tumors over 1 cm in diameter appeared to be maximally stimulated in vivo and incapable of further stimulation by the same tumor cells in vitro. This was reflected by the progressively increasing background levels of nucleic acid synthesis with the length of tumor-bearing and the size of the tumor. Although lymph-node cells from mice with large tumors did not respond to the same tumor cells in vitro, they did have normal responses to PHA. Within 7-14 days of surgical removal of the tumor, specific lymphocyte responsiveness and background activity returned to previous normal levels, but reinoculation with 10-6 tumor cells resulted in progressive tumor growth and loss of specific in vitro responsiveness when the second tumor had reached the critical size of 1 cm in diameter. Brief exposure of tumor-immune lymph-node cells to a soluble antigen extract of the same tumor resulted in a marked increase in DNA synthetic activity compared to that obtained after exposure to a different tumor extract, muscle extract or medium alone underwent stimulation when cultured with mitomycin-blocked tumor cells. However, normally responsive tumor-immune lymph-node cells, after brief exposure to a soluble antigen extract of the same tumor, initially underwent increased DNA synthesis, but were incapable of further stimulation by mitomycin-blocked tumor cells. Tumor antigen, alone or complexed with antibody, was also demonstrated in the sera of mice bearing large tumors and is thought to be responsible for the refractoriness of lymph-node cells from these mice to further stimulation in vitro. These experiments demonstrate that tumor size and the consequent antigen load to which the tumor-bearing animals is subjected have a profound effect on tumor-specific lymphocyte responsiveness.
Int J Cancer 1975 Jan 15
PMID:Refractoriness of lymph-node cells from tumour-bearing animals. 4 43

Spontaneous regression and/or remission of Friend virus (FV)-induced splenic erythroblastic leukemia was observed in CD-1 mice infected with several isolates of FV. Regression of splenic tumor was accompanied by the loss of both specific FV-induced cell membrane antigen (FVMA) and virus group-specific antigens (gsa) from the spleen cells. The frequency (percentage) of immunoglobulin-positive cells (B) and thetapositive cells (T) in the spleen was markedly decreased during leukemia progression, but there was a subsequent increase during regression. The appearance of gsa-positive (gsa+) cells in peripheral blood correlated well with the early progressive and regressive phase of leukemia (up to 7 weeks after infection). Later, the presence of these cells became unpredictable in regard to status of disease. Gsa+ blood cells reappeared in most mice with regressed splenic tumors, suggesting persistence of the virus complex in the animals. Antibody responsiveness as determined by the numbers of hemolytic plaque-forming cells, PFC, after a single immunization with sheep red blood cells (SRBC), was suppressed in leukemia progression and recovered, spontaneously, during regression of leukemia. However, hemolytic PFC elicited by antigen in both progressors and regressors expressed the specific virus-induced membrane antigen, FVMA, detectable by the PFC-inhibition test with specific antiserum and complement. Recovery of immunological responsiveness also included the spontaneous appearance of virus-neutralizing antibody to FV. However, this was not paralleled by the appearance of antibody to FVMA. Traces of anti-FVMA antibody activity were occasionally detectable in serum of both progressors and regressors and did not correlate with virus neutralization, in individual mice; This may explain the susceptibility of regressors to secondary relapse and to reinfection.
Int J Cancer 1975 Feb 15
PMID:Expression of virus-associated antigens and immune cell functions during spontaneous regression of the Friend viral murine leukemia. 4 47

Palliative urinary diversion was done in 47 cases for ureteral obstruction secondary to advanced pelvic malignancy. The average survival time was 5.3 months, with only 50 per cent of the patients alive at 3 months and only 22.7 per cent alive at 6 months. After the diversion 63.8 per cent of the survival time was spent in the hospital. Patients with carcinoma of the prostate fared better than those with other sites of tumor origin, which may reflect the natural history of this tumor.
 ...
PMID:Palliative urinary diversion for pelvic malignancy. 4 18

The metabolic mechanism for increased circulating free fatty acids in post-menopausal women with metastatic breast cancer was investigated. Hormone and metabolic response to glucose and growth hormone were compared to cancer patients and control subjects; thyroid, adrenal and pituitary function were evaluated. The results of these studies indicated that breast cancer patients had glucose intolerance and delayed and prolonged insulin secretion, increased basal growth hormone levels and insensitivity of adipose tissue to growth hormone. Cortisol and protein-bound iodine levels were normal and there was no lipolytic factor in the sera of breast cancer patients. The changes observed in breast cancer patients were not attributable to age, obesity, inanition or stress. These metabolic abnormalities may characterize host susceptibility to breast cancer or be effects of tumor.
 ...
PMID:Metabolic parameters in women with metastatic breast cancer. 4 95

Morphologic, tissue culture, immunologic, and biochemical methods have been used in an attempt to detect and characterize oncogenic viruses or their subviral components in cells derived from human prostatic carcinoma (PrCa) or benign prostatic hyperplasia (BPH). Electron microscopy was used to characterize the ultrastructural features of normal and neoplastic prostatic tissue. Examination of specimens of prostatic tissue from 34 patients with PrCa, ten patients with BPH, and three patients with bladder tumor (BT) revealed the presence of particles resembling type-C virus in three cases of PrCa and structures resembling budding type-C virus particles in one case of BPH. Fifty human prostatic tissue specimens have been set in tissue culture, of which 30 have been successfully grown for varying periods of time. Of 20 currently active cultures, nine consist primarily of epithelial cells. Immunofluorescence and mixed hemadsorption tests of cells derived from benign and malignant prostatic tissue and sera derived from patients with PrCa, BPH, BT, and other types of tumors, and from normal donors revealed that sera from patients with PrCa, BPH, or BT contain antibodies to antigens in cells derived from PrCa, BPH, or BT. The nature of these antigen-antibody reactions is under study. Initial biochemical studies have not detected reverse transcriptase in the tissue culture fluid from a small number of sparsely growing PrCa cultures nor specific gene sequences homologous to murine leukemia virus-Rauscher genomic RNA in preparations of either normal or malignant prostatic cell DNA. The results of these preliminary studies have demonstrated the applicability of the techniques employed to the study of the relationship of viruses to human PrCa and have provided a number of promising leads for further investigation.
Cancer Chemother Rep
PMID:Virologic and immunologic studies of human prostatic carcinoma. 4 14


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>