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

The authors have studied the influence of primary, methylcholanthrene-induced tumor on T and B lymphocytes of spleen, thymus, draining lymph nodes and peripheral blood of rats. Differences in weight of tumors were found to correlate with changes in proportionality of T and B lymphocytes of followed organs. Small tumors induced but insignificant changes. There was increased trapping of T lymphocytes in spleen and lymph nodes with simultaneous decrease in peripheral blood. The authors noted a high percentage of blasts. B lymphocytes showed a tendency to compensate for the loss of T cells. Large, progressively growing tumors caused evident exhaustion in the number of both cell types in lymph nodes and peripheral blood. In the spleen there was slower exhaustion. Reduction in the number of B lymphocytes correlated with the size of tumor. Blasts disappeared. Proportionality of T and B lymphocytes in thymus did not appear to be influenced by the size of tumor.
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PMID:Studies on T and B lymphocytes in rats bearing methylcholanthrene-induced tumor. 31 20

The kinetics of T and B lymphocytes were studied in the spleen, the lymph nodes, peripheral blood and the thymus of tumor-bearing rats in a time dependence following tumor transplantation with varying doses of allogeneic tumor cells. The dose of the transplanted tumor cells proved to be a limiting factor in the altered proportions of T and B cells in the various phases of immunological response of the tumorous host. A lower dose of tumor cells induced but a nonsignificant decline in the numbers of T lymphocytes in correlation with tumor growth and the tumor rejected within 19 days. A high dose of tumor cells caused an evident exhaustion of T cells in all the lymphoid organs followed (excepting the thymus), and the tumor was not rejected even by the end of the experiment. Evidently, the presence of tumor cells did not affect the B cell pool. The results are interpreted in the sense of a functional heterogeneity of the various subpopulations of T lymphocytes. The reactivity and responsibility of these subpopulations in the phase of tumor growth and its rejection is discussed.
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PMID:Kinetics of thymus- and bone marrow-derived lymphocytes in rats during tumor growth. 33 15

Mediastinal and hilar renal cell carcinoma metastases are reported in 9 patients, representing an incidence rate of 8 per cent in the series. This observation indicated an ominous prognosis since the mean survival of these patients was only 1.4 months after the discovery of the neoplasm. It is postulated that this poor prognosis is attributable to the size of the primary lesion, with direct extension into retroperitoneal structures and perhaps to an associated exhaustion of immunologic defense mechanisms of the patients. Dissemination from the involved retroperitoneal lymphatics to the thoracic duct and then in retrograde fashion via the bronchomediastinal and paratracheal trunks is advocated as the pathway for this tumor dissemination.
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PMID:Renal cell carcinoma presenting with metastases to pulmonary hilar nodes. 91 45

Administration of hyperimmune antibody to leukemia L1210 to allogeneic mice inhibited the development of macrophage-mediated immunity to L1210 in those hosts. In contrast to immunized mice, animals pretreated with antibody showed rapid activation of their peritoneal macrophages, followed by their disappearance and the inability of the residual peritoneal monocytic cells to attach L1210 cells even in the presence of proved cytophilic antibody to L1210. The inhibitory activity of the antibody, which resided entirely in its IgG2 fraction, was manifested only when the specific antigen (L1210 cells) was also injected within 2 days. Pretreatment with antibody to a different leukemia, EL4, failed to inhibit the monocytic uptake of L1210, but it did inhibit uptake of EL4 by monocytes if injected with its homologous antigen. Restoration of the functional capacity of macrophages was accomplished by injecting 1 X 10-7 bone marrow cells i.v. into "suppressed" mice, but 1.5 X 10-7 thymocytes failed to correct the defect. Significantly, thymocytes antagonized the restorative capability of bone marrow cells when they were injected concomitantly. These results indicate that specific inhibition of cytophilic antibody receptors on monocytes could be accomplished through a direct mechanism involving activation and exhaustion of macrophages and an indirect mechanism, perhaps mediated through "suppressor" thymus-derived cells. Although enhancement of the growth of leukemia cells did not occur, several parallels exist in mice with enhanced growth of different tumors. This inhibiotry phenomenon may thus represent another instance of "blocking" in tumor immunity, where the target of suppressive antibody-antigen is the macrophage as well as the lymphocyte.
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PMID:Analysis and reversal of the inhibition of cytophilic antibody receptors produced by antibody. 107 91

Recent publications point towards a probable influence of trace elements on the cancerogenicity of chemical substances. On the basis of these reports we chose Al(OH)3 as trace element in our experiments, trying to clarify the influence of some adjuvants of vaccines on oncogenesis as described by several authors. To female NMRI-mice we applied subcutaneously 10 mug, 50 mug, 100 mug benzo(a)pyrene respectively in 0,5 ml tricaprylin-Al(OH)3-gel mixture and compared it with similar doses of benzo(a)pyrene in 0,5 ml tricaprylin-NaCl solutions. Results of experiments: 1. Al(OH)3 considerably reduced the tumor formation in the groups, treated with 10 and 50 mug benzo(a)pyrene; even tumor rates in the 100 mug benzo(a)pyrene group were diminished but much less than by the lower doses. 2. After ninety weeks the amount of tumors in the groups treated with 10 or 50 mug benzo(a)pyrene + Al(OH)3 was significantly lower than that of their control groups. At the highest doses (100 mug) a significant difference could not be noted. 3. Mean periods of tumor induction within all groups treated with benzo(a)pyrene-Al(OH)3 were significantly prolonged in comparison to controls. 4. In experiments with subcutaneously treated mice the doses-effect-relationship is changed when Al(OH)3 corresponds to the results of experiment with atmospheric dusts or exhaustion condensates. It is still pending whether adsorbtive or other processes make this effect.
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PMID:Investigations on the carcinogenic burden by air pollution in man. XI. About the effect of aluminiumhydroxid upon the benzo(a)pyrene carcinogenesis. 116 75

The kinetics of monolayer cell cultures, derived from brain tumors which had been labeled with 3H-thymidine just prior to surgical removal, have been investigated. Analysis of autoradiographs indicates that: 1. the distribution of cell types in primary cultures is similar to that of the viable areas of the parent tumor in vivo; 2. the first week of culture constitutes a lag phase; and 3. vigorous proliferation commences during the second week of culture. Double labeling of the tritiated cultures with 14C-thymidine indicates that the pulse labeling index (PLI) of primary cultures during the second week is lower than that of the parent tumor and that the PLI of the culture increases during the second week. In contrast, we found that long-term established cultures in our laboratory have a high PLI during the first few days after passage, quickly reach a maximum, and then drop precipitously 1 week after passage. These latter variations in PLI correspond to the following growth pattern: 1. exponential growth; 2. a stationary phase due to medium exhaustion; or 3. a a plateau due to overcrowding. There are indications that some cell types, which have the capacity to divide in the parent tumor, lose this ability after transfer to tissue culture.
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PMID:The kinetics of cultured human glioma cells: autoradiographic studies. 118 4

The regional lymph nodes from 47 patients with carcinoma of the bladder who had undergone radical cystectomy and bilateral pelvic lymphadenectomy were classified into 3 histologic patterns that correlated with immunologic function. Lymph nodes were designated as stimulated if they exhibited prominent germinal centers (B cell proliferation) and expansion of the deep cortex (T cell proliferation), depleted if they appeared markedly hypocellular and fibrotic, and unstimulated if they resembled a normal resting lymph node. Correlation of the histologic pattern with the extent of disease revealed that patients whose nodes appeared stimulated had fewer metastases (p less than 0.05) than those with either unstimulated or unstimulated combined with a depleted pattern. A markedly improved 5-year survival rate was seen in patients with a stimulated pattern (p less than 0.0001) compared to those patients who exhibited a depleted and/or unstimulated lymph node pattern. The survival advantage related to the stimulated pattern was observed primarily among patients with advanced disease. It is suggested that stimulated nodes reflect proliferation of T and B lymphocytes engaged in cell-mediated and humoral immune responses to the bladder tumor and that this favorably influenced survival in those patients. Patients whose lymph nodes showed a depleted pattern fared poorly despite the extent of the disease and those with an unstimulated pattern were intermediate in survival. A depleted pattern may represent a state of local immune paralysis, exhaustion of the draining lymph nodes as a result of exposure to excess tumor-derived products such as antigen or toxic substances or simply an atrophic node incapable of response. In the absence of a local immune response such patients might be expected to do poorly. These results suggest that morphologic evaluation of the lymph nodes regional to bladder cancer may provide a clue to their immunologic function and a more accurate guide to prognosis of patients with this neoplasm.
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PMID:Prognostic significance of regional lymph node histology in cancer of the bladder. 125 85

The peculiarities of the development of spontaneous fluctuations of the c.s.f. pressure (CSFP) (B- and plato-waves) in the early postoperative period in 169 neurosurgical patients were studied according to the location of the pathological process and the severity of the clinical condition. The dependence between the CSPF spontaneous fluctuations, the changes of intracerebral pressure, and the dynamics of bioelectrical activity of the brain was studied. The development of spontaneous wave CSFP fluctuations was found to be dependent on the location of the tumor and the severity of the clinical condition. These fluctuations occurred most frequently in patients who were in a critical state (12-8 marks on Glasgow's scale) with the process located in the diencephalo-stem brain areas. A hypothesis is suggested, according to which the cause of the wave CSFP fluctuations of the B-wave type is connected with the change of the vasomotor center to the cyclic regimen of work: the neurogenic change of the vascular tonus, causing in succession constriction and dilatation of the vessels, leads to rhythmic CSFP oscillations. CSFP plato-waves occur in cases in which the constriction phase fails to appear after the dilatation phase, i.e., the tonic pressor effect of the vasomotor center does not occur, which may be due to its exhaustion. In death of the brain and in terminal states the vasomotor center loses the ability to cause neurogenic regulation of the vascular tonus, to provide the pressor effect in particular, which leads to the disappearance of spontaneous CSFP fluctuations.
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PMID:[The mechanism of the development of spontaneous fluctuations in the cerebrospinal fluid pressure ("plateau" and B waves)]. 166 35

In cases of tumor surgical operation, which stimulated metastatic spreading, distinct activation of hypothalamic structures was observed simultaneously with generalization of impairments in the neurotransmitting systems, accompanied by their exhaustion and disturbance. Pathology-related alterations in brain neurotransmitting reactions, provoked by surgical operation in cases of tumors, considerably exceeded similar parameters in non-operated or sham-operated animals.
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PMID:[Biochemical characteristics of the brain mediator systems during stimulation of metastasis from surgical removal of a tumor]. 168 57

Human hematopoietic cells can be maintained in vitro for many weeks in the absence of exogenously provided hematopoietic growth factors if an adequate stromal cell containing adherent layer is present. We have now extended the use of this type of long-term culture (LTC) system to create a model of perturbed hematopoiesis in which human tumor cells that constitutively produce a variety of factors are co-cultured together with normal human marrow cells. In the present study, we used the human bladder carcinoma cell line (5637) because these cells were known to produce not only a variety of factors active directly on hematopoietic cells but also factors that can stimulate hematopoietic growth factor production by human marrow stromal cells. Analysis of mRNA extracted from the adherent layer and measurement of growth factor bioactivity in the medium of established LTC of human marrow containing irradiated 5637 cells, showed increased levels of interleukin-1 and -6, as well as granulocyte and granulocyte-macrophage colony-stimulating factor production by comparison to control cultures. As in normal cultures, high proliferative potential clonogenic hematopoietic cells were found almost exclusively in the adherent layer of these co-cultures, but these primitive cells were maintained in a state of continuous turnover, in contrast to control cultures where the same cell types showed the expected oscillation between a quiescent and a proliferating state following each weekly change of the medium. A similar perturbation of primitive progenitor cycling was achieved by adding medium conditioned by 5637 cells twice a week to otherwise normal LTC. The presence of irradiated 5637 cells in the LTC or the addition of 5637 conditioned medium also resulted in modest (2- to 3-fold) but sustained increases in the total hematopoietic progenitor population, as well as in the final output of terminally differentiated granulocytes and macrophages. These findings indicate that primitive hematopoietic cells in LTC can be kept in a state of continuous activation for many weeks by appropriate endogenous or exogenous hematopoietic growth factor provision and that this does not necessarily lead either to their rapid exhaustion or to a large amplification in output of mature progeny.
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PMID:Continuous activation of primitive hematopoietic cells in long-term human marrow cultures containing irradiated tumor cells. 171 96


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