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Query: UMLS:C1275122 (TEM)
 21,810 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peripheral lymphocytes treated with phospholipase C (phosphatidylcholine cholin phosphohydrolase E [3.1.4.3]) were examined for their response to mitogen and rosette formations. High levels of phospholipase C (greater than 0.01 unit) showed significant toxic effects on the peripheral lymphocytes as examined by the trypan blue exclusion test. This was attributable to "impurities" in the Cl. perfringens phospholipase C preparation since recovery of the mitogen responses were incomplete after heat inactivation of the enzyme. Active phospholipase C at 0.005 unit significantly (50%) suppressed the PHA response with little or no effect on the PWM stimulation. Similarly, a significant suppression of E rosette formation occurred with phospholipase C (0.005 u) treated lymphocytes. Suppression of similarly treated lymphocytes to EAC rosette was slight. It is suggested that the removal of phosphorylated amines from membrane surfaces affects T-cells more than B-cells and that the use of phospholipase C is a useful means of examining membrane functions of the lymphoid system.
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PMID:Effect of phospholipase C on lymphocyte responses to mitogen. 95 57

We have studied peripheral blood lymphocyte populations, defined in terms of their E and EAC' rosette-forming capacity in patients with Burkitt's lymphoma and controls. Total lymphocyte counts were reduced in patients compared to controls (p less than 0.005), and correlated with clinical stage and disease status. Presenting patients with Stage D tumours had the lowest levels, while patients in remission for at least 18 months had total lymphocyte counts similar to those of controls. Absolute numbers of both E and EAC' rosette-forming cells (RFC) were reduced, compared to controls, in tumour-bearing patients (p less than 0.0005 for both E and EAC' RFC) and also, to a lesser extent, in patients in remission (p less than 0.025 and less than 0.05 for E and EAC' RFC respectively). In the case of E RFC a significant reduction was present even when patients in remission for over 18 months were considered alone (p less than 0.05). Non-RFC were present in similar numbers in patients and controls, so that the reduction in total lymphocyte count can be accounted for entirely by the reduced numbers of RFC. As anticipated by this, percentages of RFC were also reduced in patients compared to controls, EAC' RFC to a lesser extent than E RFC. Non-RFC percentages were correspondingly increased. Tumour-bearing patients had significantly impaired PHA responses and cutaneous reactivity, which correlated significantly with very low levels of RFC. One possible explanation for these results is that immunoreactive lymphocytes are sequestered within the tumour. This is consistent with the immunosuppression observed in tumour-bearing patients, and would also result in difficulty in detecting even a powerful tumour-specific immune reaction by means of an assay dependent upon the participation of peripheral blood lymphocytes.
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PMID:Immunosuppression in Burkitt's lymphoma. II. Peripheral blood lymphocyte populations related to clinical status. 97 86

Heterogeneity of human T lymphocytes was examined by the rosette formation of sheep red blood cells (E-rosette) in two different reaction media: fetal calf serum (FCS) and gelatin Veronal buffer (GVB). Nearly all the T lymphocytes could form rosettes in FCS at 1 degrees C (FCS-R) independently of the incubation time. In contrast, rosette formation in GVB (GVB-R) was apparently dependent upon the incubation time and could not be used in the enumeration of the total T cells even after long incubation. Among the possible subpopulations, a fraction (T1) that could form GVB-R as well as FCS-R, and the other fraction (T2) that could form only FCS-R were partially purified by rosette formation and by density gradient on a Ficoll-Isopaque layer. In contrast to the T cell-depleted fraction (B) which formed EAC rosettes in a majority of cells and E rosettes in a few cells, only a small portion of cells from both the T1 and T2 fractions could form EAC-rosettes. T1 cells possessed high responses to PHA as estimated by the counts of 3H-TdR incorporation as well as the stimulation indices. In contrast, T2 cells possessed a lower responsiveness to the mitogen, and B fraction cells could not respond at all. These results suggested that a positive correlation exists between the ability of E rosette formation and responsiveness to PHA in the T cell subpopulations. Preliminary experiments also suggested that percentages of T1 cells highly responsive to PHA may decrease and, therefore, those of T2 cells less responsive to the mitogen may increase in the T cell population of the patients with some immunodeficiencies.
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PMID:Heterogeneity of human T lymphocytes to bind sheep erythrocytes and mitogenic responses of their subpopulations. 108 Nov 2

The cytotoxic functions of highly purified blood lymphocytes from patients with breast cancer were studied before and after radiotherapy. Addition of PHA or of rabbit antibodies to target cells (chicken erythrocytes) were chosen as two means of inducing lymphocyte cytotoxicity in vitro. The proportion of T and non-T-lymphocytes was determined by means of E and EAC rosette tests. The antibody-induced cytotoxocity of lymphocytes decreased following radiotherapy while that mediated by PHA remained unchanged. There was some reduction in the percentage of EAC rosette-forming cells. These results, as well as our earlier observations, suggest that the decrease in the peripheral blood of the proportion of lymphocytes with receptors for activated complement is responsible for changes in the antibody-mediated lymphocyte cytotoxicity.
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PMID:Effect of radiotherapy on lymphocyte cytotoxicity in vitro. 108

Thymus-derived and non-thymus-derived peripheral blood lymphocytes were examined by means of E- and EAC-rosette tests. The frequency of these lymphocyte populations was the same in hyperthyroid and euthyroid individuals. It was also demonstrated that PHA responsiveness of lymphocytes from hyperthyroid patients was equal to that of lymphocytes from euthyroid controls and did not change after treatment with 131I.
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PMID:Lymphocyte populations in peripheral blood in hyperthyroid and euthyroid subjects. 108 17

Peripheral blood lymphocytes were investigated in 20 patients with acute viral hepatitis. For assessment of B lymphocytes the rosette test was carried out using sheep erythrocytes coated with antibodies and murine complement. T lymphocytes were recognized by their ability of binding uncoated sheep erythrocytes. In 16 cases the results of EAC test in patients with viral hepatitis resembled those in healthy donors. In 3 cases a significant decrease was observed and in one case a significant rise was found in the number of cells forming EAC rosettes. The T lymphocyte count was within normal range in 19 investigated cases. The results suggest that impaired T lymphocyte reactivity to PHA in acute viral hepatitis is due to a disturbed function of T lymphocytes and not to a decrease in their number. In cases associated with significant hepatocellular damage a reduction in the number of circulating B lymphocytes was observed.
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PMID:B and T lymphocytes in viral hepatitis. 108 13

The nature of the immune response to the tumor cell is complex and has yet to be clearly defined. Although past research has foscused on the cytotoxic effect of T lymphocytes versus tumor cells, it has been shown in animal studies that B lymphocytes may also be implicated. Lymphocytes from patients with respiratory and digestive tract tumors were studied. B and T lymphocytes of peripheral blood and of draining lymph node tumors were studied using the following techniques: E rosettes (marker for T cells); membrane Ig, EAC rosettes, aggregated-Ig (marker for B lymphocytes); PHA and PKW in vitro response of lymphocytes using tritiated thymidine incorporation. It was observed that both groups of patients had normal or depressed B and T populations. PHA response was depressed in the majority of the cases with lung tumor. No difference was observed between lymphocytes from peripheral blood and from lymph node suspensions. As in normal lymph nodes the EAC rosettes were constantly observed in the cortical area of lymph node draining tumors. The immune defect observed in part of these cases is discussed in relation to the local and general immunological factors probably responsible for this defect.
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PMID:[Histological and immunological study of patients with lung and digestive tract tumors. Analysis of T and B lymphocytes from the peripheral blood and from the lymph nodes draining the tumor (author's transl)]. 108 74

PHA stimulation of peripheral blood lymphocytes and/or leukemic cells has been studied in 65 patients with acute leukemia before any prior treatment. There were 38 patients with A.L.L. and 27 with A.M.L. In relapsing A.L.L. 15 observations were made before reinduction therapy. In about 40% of all the cultures PHA stimulation was done simultaneously with PWM-stimulation. Before any treatment normal lymphocytes showed a normal response, being however somewhat diminished at relapse. Most of the cases of A.M.L. had so many leukemic cells in peripheral blood that no reliable measure of stimulation of the few lymphocytes left was possible. In A.L.L. this was however possible in about 30% of all the cases studied. In cultures of the predominantly leukemic cells, lymphoblasts showed a positive response in a minority of cases studied. If the peripheral WBC-count was high, a response was usually absent. In some of the cases of A.M.L., the leukemic cells reacted to PHA and PWM. Unexpected but very remarkable is our finding that in the control cultures, without added mitogen, the incorporation of labelled 3H-thymidine was usually very high in A.M.L. contrasting with A.L.L. leukemic cells who incorporated very little of the label. These striking differences were observed both in 72 and 144 hours cultures and were not caused by differences in viability between these two leukemic cell-types. The capacity of A.L.L.-leukemic cells to form E ("T") and EAC ("B") rosettes was studied in 20 cases. The percentages of rosette forming lymphoblasts differed widely from patient to patient. It is concluded that in A.L.L. leukemic cells are in a minority immuno-competent cells and it is suggested that the lymphoblast is an immature cell, arrested in the maturation towards a T-lymphocyte, the degree of maturity differing from patient to patient. Furthermore the striking difference in spontaneous labelling of myeloid versus lymphoblastic leukemic cells seems to be helpful in the differential diagnosis and may in part explain the well known differences in prognosis and behaviour towards cytostatics between these main leukemia types.
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PMID:T-cell qualities of lymphocytes and/or leukemic cells from peripheral blood in acute myeloid and lymphatic leukemia before treatment and at relapse. 108 49

Human peripheral blood and tonsil lymphocytes were fractionated on anti-Ig-coated Sephadex columns or by centrifugation after rosetting with native sheep erythrocytes. Both methods allowed the recovery of B and T-enriched populations the purity of which was checked by fluorescein-labelled anti-Ig serum, E and EAC rosette formation, and heterologous antisera specific for B or T lymphocytes. The proliferative response of T cells to PHA, Con A, PWM, and ALS was not found different from that of unfractionated cells, whereas no response of the B cells could be observed to these mitogens providing that no contaminating T cells were present. Addition of T lymphocytes to these unresponsive B cells allowed them to respond to phytomitogens, but not to ALS. X-irradiated T cells could, to some extent, replace the diving T lymphocytes; no T-replacing factor could be found in cell-free supernatants from T cells, whether or not they had been activated by mitrogens. This model of B-T cooperation appears useful for studying the differentiation and maturation of human B lymphocytes.
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PMID:T-dependence of human B lymphocyte proliferative response to mitogens. 108 30

The lymphoblastic response (LTT) to non-specific mitogens (PHA, PWM and ConA) of peripheral lymphocytes was investigated at days 0, 7, 14, 21 and 28 after adjuvant injection in four strains of inbred rats: Wistar (WAG), Long Evans (LE), Lewis (LEW) and Brown Norway (BN). LTT was assessed by using 18 hours H3 TdR incorporation in 5 days cultures of whole blood (micromethod). The statistical treatment of data, using principal components multifactorial analysis and analysis of variance showed a striking difference between strains. In control animals the responses to PHA and PWM were correlated and were higher in LE and WAG than in LEW and BN (BN=LEW less than LE=WAG). The response to ConA was independent of that to the other mitogens. It was generally low, but significantly higher in LEW and BN than in WAG and LE. In adjuvant-injected animals the responses to PHA and PWM were still correlated, but modified compared to control: in LE and LEW, but not in WAG and BN, a marked decrease of the response was found, reaching a minimum value within days 7 and 14. In the same time the response to ConA increased in the four strains, later in LE than in the others. However the intensity of the ConA response varied from one strain to another: it was constantly low in LE and WAG compared to LEW and BN. So the most striking modification of LTT were observed in LE and LEW, which both developed the most severe arthritis. However these different behaviours after adjuvant injection were not explained by the initial level of LTT to the different mitogens. These data suggest that the development of intense arthritis is associated with the proliferation and the release into the blood stream of a lymphocyte subpopulation, which exhibits a low response to PHA and PWM and a high response to ConA. These LTT modifications are not paralleled by quantitative variations of B-cells assessed by surface Ig immunofluorescent staining and EAC rosetting.
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PMID:Adjuvant-induced arthritis in four inbred strains of rats. An in vitro study of peripheral T and B lymphocytes. 108 95


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