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

The late effects of various immunosuppressive insults on cell-mediated immunity in mice were studied in an attempt to assess the role of immune surveillance in the aging process. Results were obtained using susceptibility to allogeneic tumor cell challenge, graft-versus-host reaction (GVHR), blastogenic response to PHA, a thymus derived T cell-specific plant mitogen, and cytolytic activity against allogeneic tumor cells as measures of immunologic activity. In vivo studies late in life show that resistance to allogeneic tumor cells is significantly decreased in thymectomized mice, whereas those treated with cortisone, cyclophosphamide and sublethal X-ray remain unchanged. Spleen cells from only the thymectomized and the sublethally irradiated mice show reduced activity in the GVHR. No difference is seen in the activity of bone marrow cells. Results consistent with these findings were obtained in in vitro studies. Thus spleen cells from thymectomized or sublethally irradiated mice show decreased activity is response to PHA, whereas no change is seen in spleen cells from other treated groups. Hence, surgical and physical insults are more likely to induce long-lasting immunosuppression in those immunocompetent tissues whose activity normally diminishes with advancing age. Furthermore, the degree of immunosuppression seen in this study is not of the order of magnitude that one could reasonably predict a significant decrease in mean life-span.
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PMID:The late effects of selected immunosuppressants on immunocompetence, disease incidence, and mean life-span. II. Cell-mediated immune activity. 0 May 62

The objective of this investigation was to throw light on the biological behavior and metabolic regulation of hepatic enzymes of the nonoxidative branch of the pentose phosphate pathway. The activities of transaldolase (EC 2.2.1.2) and trasketolase (EC 2.2.1.1) Were compared in biological conditions that involve modulation of gene expression such as in starvation, in differentiation, after partial hepatectomy, and in a spectrum of hepatomas of different growth rates. The enzyme activities were determined under optimal kinetic conditions by spectrophotometric methods in the 100,000 X g supernatant fluids prepared from tissue homogenates. The kinetic properties of transaldolase and transketolase were similar in normal liver and in rapidly growing hepatoma 3924A. For transaldolase, apparent Km values of 0.13 mM (normal liver) and 0.17 mM (hepatoma) were observed for erythrose 4-phosphate and of 0.30 to 0.35 mM for fructose 6-phosphate. The pH optima in liver and hepatoma were at approximately 6.9 to 7.2. For the transketolase substrates, ribose 5-phosphate and xylulose 5-phosphate, the apparent Km values were 0.3 and 0.5 mM, respectively, in both liver and hepatoma. A broad pH optimum around 7.6 was observed in both tissues. In organ distribution studies, enzyme activities were measured in liver, intestinal mucosa, thymus, kidney, spleen, brain, adipose tissue, lung, heart, and skeletal muscle. Taking the specific activity of liver as 100%, transaldolase activity was the highest in intestinal mucosa (316%) and in thymus (219%); it was the lowest in heart (53%) and in skeletal muscle (21%). Transketolase activity was highest in kidney (155%) and lowest in heart (26%) and skeletal muscle (23%). Starvation decreased transaldolase and transketolase activities in 6 days to 69 and 74%, respectively, of those of the liver of the normal, fed rat. This was in the same range as the decrease in the protein concentration (66%y. In the liver tumors, transaldolase activity was increased 1.5- to 3.4-fold over the activities observed in normal control rat liver. Transketolase activity showed no relationship to tumor proliferation rate. In the regenerating liver at 24 hr after partial hepatectomy, the activity of both pentose phosphate pathway enzymes was in the same range as that of the sham-operated controls. In differentiation at the postnatal age of 5, 12, 23, and 32 days, hepatic transaldolase activities were 33, 44, 55, and 72%, respectively, of the activities observed in the 60-day-old, adult male rat. During the same period, transketolase activ-ties were 18, 21, 26, and 55% of the activities observed in liver of adult rat. The demonstration of increased transaldolase activity in hepatomas, irrespective of the degree of tumor malignancy, differentiation, or growth rate, suggests that the reprogramming of gene expression in malignant transformation is linked with an increase in the expression of this pentose phosphate pathway enzyme...
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PMID:Behavior of transaldolase (EC 2.2.1.2) and transketolase (EC 2.2.1.1) Activities in normal, neoplastic, differentiating, and regenerating liver. 1 80

We have used indirect immunofluorescence to study antibody responses directed against membrane antigens expressed on in vitro and in vivo T1699 mammary adenocarcinoma cells. IgG1, IgG2a, IgG2b, IgG3, IgA, and IgM antibodies were present in the serum of DBA/2 mice bearing T1699 tumors; IgG2a and IgG2b antibodies were readily detected on the cells in situ. Lesser amounts of the other classes and subclasses could be detected by indirect immunofluorescence measurements on in vivo tumor cells and with low pH eluates of in vivo cells tested on the in vitro line of T1699. The antigenic determinants on in situ tumor cells are not saturated with antibody as these cells demonstrated enhanced fluorescence of all immunoglobulin classes and subclasses when treated with autologous serum. Experiments with thymus-depleted mice indicated that immunoglobulin production was strongly dependent on thymus-derived cells for all immunoglobulin classes and subclasses except IgG2b. Our studies suggest that IgG2a may be active in the macrophage-mediated cytotoxic reaction and IgG2b in the immediate hypersensitivity reaction to T1699 cells. These results provide further evidence for an active role of tumor-specific antibody in the host defense to the T1699 adenocarcinoma in situ.
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PMID:The antibody response to the T1699 murine adenocarcinoma: antibody class and subclass heterogeneity detected in serum and in situ. 1 30

This report concerns a 49 year old asymptomatic male who had a mediastinal mass demonstrated on routine radiography. A large encapsulated tumour composed of small regular cells arranged in clumps and acini with fine vascular stroma was removed. The differential diagnosis on routine H&E section included parathyroid tumor, medullary carcinoma arising in ectopic thyroid tissue, epithelial thymoma or carcinoid tumor of the thymus. The presence of compressed thymic tissue around the tumor, and of argentaffin granules together with the electron microscopic appearance characteristic of the "enterochromaffin" or "APUD" group of cells allowed the diagnosis of carcinoid tumor of the thymus to be made. Electron microscopy showed that the cell cytoplasm contained electron dense membrane bound granules, together with bundles of microfilaments. Vesicles of smooth surfaced reticulum were present but rough surfaced reticulum was inconspicuous. No desmosomes were demonstrated. Special stains for amyloid and glycogen were negative.
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PMID:Carcinoid tumour of the thymus. A case report including discussion of the morphological diagnosis and the cell of origin. 2 95

Following intravenous administration, 2'-deoxycoformycin (0.25 mg/kg) was rapidly distributed to tissues of both normal mice and mice bearing L1210 leukemia cells and readily eliminated, primarily by urinary excretion. Elimination of 2'-deoxycoformycin from plasma was biphasic, and half-lives for the alpha- and beta-phases of 10 and 33 min for normal mice and 7 and 40 min for L1210-bearing animals. The volume of distribution at steady state was approximately 20 ml, suggesting that the drug was distributed in the total body water for both groups of mice. The kidney, liver, small intestine, spleen, thymus, and L1210 tumor had tissue/plasma ratios greater than or equal to 1 at 15 min after dosing. In both groups, greater than 90% of the dose of 2'-deoxycoformycin was recovered in the urine within 3 hr. As determined by bioautography of urine samples, no detectable metabolism occurred. The presence of the L1210 tumor caused changes in the tissue distribution of 2'-deoxycoformycin. At later time periods, tissues from tumor-bearing mice contained significantly higher levels of this drug when compared to normal mice. However, the tumor was without significant effect on blood levels or urinary excretion of 2'-deoxycoformycin.
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PMID:Pharmokinetics of 2'-deoxycoformycin in normal and L1210 leukemic mice. 3 19

A new method for the analysis and purification of the RNA-directed DNA polymerase of RNA tumor viruses has been developed. This nucleic acid affinity chromatography system utilizes an immobilized oligo (dT) moiety annealed with poly (A). The alpha and alphabeta DNA polymerases of avain myeloblastosis virus bound effectively to poly (A) oligo (dT)-cellulose. Alpha DNA polymerase did not bind effectively to poly (A) oligo (dT)-cellulose, poly (A)-cellulose, or to cellulose. Alphabeta bound to oligo (dT)-cellulose and cellulose at the same extent (approximately 30%), indicating that this enzyme did not bind specifically to the oligo (DT) moiety only. However, alphabeta bound to poly (A)-cellulose two to three times better than to cellulose itself, showing that alphabeta could bind to poly (A) without a primer. Alphabeta DNA polymerase also bound to poly (C)-cellulose, whereas alpha did not. These data show that the alpha DNA polymerase is defective in binding to nucleic acids if the beta subunit is not present. Data is presented which demonstrates that the alphabeta DNA polymerase bound tighter to poly (A). oligo (DT)-cellulose and to calf thymus DNA-cellulose than the alpha DNA polymerase, suggesting that the beta subunit or, at least part of it is responsible for this tighter binding. In addition, alphabeta DNA polymerase is able to reversibly transcribe avian myeloblastosis virus 70S RNA approximately fivefold faster than alpha DNA polymerase in the presence of Mg2+ and equally efficient in the presence of Mn2+. alpha DNA polymerase transcribed 9S globin m RNA slightly better than alphabeta with either metal ion.
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PMID:Binding properties of avian myeloblastosis virus DNA polymerases to nucleic acid affinity columns. 4 87

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.
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PMID:[The lymphocyte cytotoxicity test in tumor immunology (author's transl)]. 4 11

Lethally irradiated mice protected with allogeneic fetal liver cells or with syngeneic or allogeneic marrow and spleen cells treated with antisera to mouse immunoglobulins or to the T cell-associated theta antigen and their controls were observed for up to 750 days. The best survival rates were found in the large groups given syngeneic marrow and spleen or allogeneic fetal liver cells (70-85% 700-day survival); in contrast, 43% of the group injected with allogeneic cells treated with anti-theta serum and 19% of those given antiimmunoglobulin-treated cells were alive 700 days postradiation. Pulmonary infection was the most frequent cause of death of long-term survivors in all groups. Tumor incidence was increased in recipients of allogeneic cells (13% versus 4% among syngeneic chimeras), but the renal pathology seen in these groups was no greater than that noted in the syngeneic controls. Beginning 600 days after irradiation, mice from experimental and control groups were killed and their spleens were cultured with thymus-dependent antigens and the mitogens concanavalin A and lipopolysaccharide, Escherichia coli. The most frequent finding in all groups was mild to moderate impairment of T cell-dependent responses.
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PMID:Allogeneic radiation chimeras. Long-term studies. 5 Jun 55

Lymphoid cells of mice were sensitized in vivo either by H-2 strain-specific tumor allografts or by activation in lethally irradiated F1 hybrids and tested for cytotoxicity on 51Cr-labeled target cells. The release of 51Cr varied linearly with the logarithm to the proportion of effector lymphocytes to target cells and with the time of interaction. The release of 51Cr was immunologically specific and restricted to H-2 incompatibility. Spleen cells immune to public specificities of the target genotype were not cytotoxic. However, lymphoid cells immune to only one private specificity of a third-party target genotype were highly cytotoxic. The cytotoxicity of activated thymus cells on target cells sharing one private specificity with the genotype used for sensitization was significantly enhanced when the effector thymocytes were activated also against H-2 specificities not shared by the target strain. The results suggest that gene products that facilitate sensitization of effector cells may be determined both by the H-2K and the H-2D end of the H-2 complex. It remains to be shown whether the products of these loci, operating during sensitization in vivo, are body-wide correlated to the lymphocyte-defined specificities detectable during the mixed leukocyte culture interaction.
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PMID:Incompatibility at irrelevant H-2 specificities augments in vivo stimulation of alloaggressive cells. 5 89

The results of thymectomy carried out in 150 cases of myasthenia gravis are discussed. In a group of 123 cases followed for 1 to 5 years after the operation, full remission was observed in 24.4% of cases, significant improvement in 36.6%, slight improvement in 24.4% and no improvement in 8.1%, while deterioration occurred in 1.6% of patients. No correlation was found between the result of the operation and the age and sex of patients, but better results were achieved in those treated surgically rather soon after the onset of symptoms. This correlation was particularly evident in the group with full remissions. The results obtained in the cases without thymic tumors were better than in the cases with tumors. No correlation was noted between the results of the operation and the histological characteristics of the thymus in the group with thymic hyperplasia and in the group with thymic atrophy. The surgically treated group (150 cases), compared with the conservatively treated group (75 cases), showed the superiority of the surgical method (lower rate of death and deterioration, higher rate of improvement and remission). In discussing the indications for surgical treatment the authors emphasize that advances in anaesthesiology in recent years have reduced the risk of operation. It is suggested that the indications for surgical treatment should be expanded and operations should be performed as early as possible after the onset of clinical manifestations without regard to the age and sex of the patient. Operation should not be considered in cases belonging to group 1, 2a (sometimes 2b) only, with duration of the disease over 8-10 years and with little or no progression of the process, if the presence of a thymic tumor has been excluded.
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PMID:Evaluation of results of thymectomy in myasthenia gravis. 5 71


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