Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. The surface expression of β2-integrins was investigated in leukocytes from patients undergoing ischemia induced by tourniquet application for elective hand surgery. Blood samples were obtained before initiation, at the end of ischemia, and after 15 minutes of reperfusion from ischemic and contralateral arms of five patients. Comparable expression of CD18, CD11a, CD11b, and CD11c could be detected by immunofluorescence in leukocytes from samples drawn from either arm before tourniquet application. In contrast, a significant increase in the expression of CD18 was detectable in monocytes, granulocytes, and lymphocytes from the ischemic arm compared with that in the nonischemic contralateral control, at the end of the ischemia time (80 ± 16 minutes). A significantly increased expression of CD11b, but not CD11a or CD11c, determinants was also observed in granulocytes and monocytes. Concomitantly, a significant reduction in the percentages of granulocytes in samples from ischemic areas was detectable. After 15 minutes of reperfusion, differences in the expression of these adhesion molecules were no longer significant. The expression of the genes encoding interleukins IL-1α, IL-1β, and IL-6 and tumor necrosis factor alpha (TNFα) proinflammatory cytokines was also studied by reverse polymerase chain reaction (rPCR) in peripheral blood mononuclear cells (PBMCs) obtained from the same samples in three patients. IL-1β or IL-6 gene expression was never observed. Expression of IL-1α and TNFα genes, as detected in two patients, was not related with induction of ischemia. However, in these patients expression of one or both these genes was observed in samples derived from the ischemic but not the control arm after 15 minutes of reperfusion. These data document that overexpression of adhesion molecules and sequestration of leukocytes take place following short ischemia times, as routinely applied clinically for minor surgical procedures.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1434-0879
    Keywords: Key words MAGE ; Seminoma ; Tumor-infiltrating lymphocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The MAGE gene family encodes antigens that are recognized by cytotoxic T-cells. The expression of MAGE antigens has been linked to tumor stage, and MAGE peptides are under investigation as possible vaccines. Seminomas are tumors that are typically accompanied by a heavy inflammatory infiltrate, but have not been studied with regard to their MAGE antigen expression and its correlation with the inflammatory infiltrate. We investigated, therefore, MAGE protein expression, the amount of cytotoxic T-cells, clonality of the lymphocytic infiltrate, apoptotic activity and occurrence of necrosis. Specimens of 27 patients with classical seminoma were examined by immunohistochemistry for CD4, CD8, CD56, CD45R0, β2-microglobulin and HLA-DR. MAGE expression was detected with the monoclonal antibody 57B, reactive with MAGE-1, -3, -4, -6 and -12. Clonality of the inflammatory infiltrate was examined by multiplex polymerase chain reaction (PCR) analysis of the T-cell receptor rearrangement. Apoptotic cells were detected by DNA nick-end labeling of fragmented DNA, and the apoptotic index was determined semi-quantitatively. Expression of 57B was found in 19 (70%) of 27 seminomas. In all cases, more than 70% of T-cells expressed CD45R0. In four cases, a predominant infiltration of CD8-positive cytotoxic T-cells (CD4/CD8 ratio 〈1) was present. However, 15 seminomas showed a CD4/CD8 ratio 〉1. In all cases, infiltration of CD56-positive natural killer cells was only focal. HLA-DR expression was not detectable in tumor tissue; β2-microglobulin was only focal in three cases. Analysis of the T-cell clonality revealed a polyclonal population. The apoptotic index was not significantly different in 57B-positive seminomas (4.15%) compared with 57B negative seminomas (3.80%). Also, no correlation between the 57B expression and the occurrence of necrosis was found. MAGE antigens are homogeneously expressed in most seminomas, but their presence does not appear to represent a dominant epitope responsible for the lymphocytic infiltrate.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0851
    Keywords: Key words Gene therapy ; Cytokine ; NK ; Xenogenic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Eleven patients with advanced cancer were treated in a clinical gene therapy trial by repeated intra- tumoral injections with different doses of xenogenic fibroblasts secreting high amounts of human interleukin-2 (Vero-IL2). Treatments in a total of 14 courses were well tolerated and resulted in clinical responses and measurable biological effects. Together with increases in serum interleukin-2 (IL-2), modifications of the V-β T cell receptor repertoire and induction of intratumoral T-cell infiltration were observed. When the intratumoral expression of endogenous cytokine genes and the persistence of the IL-2 transgene at the application site and in peripheral blood were investigated, rapid disappearance of the transgene at the application site appeared to be the most prominent biological effect. Tests detecting a single Vero-IL2 cell against a background of 105 non-transfected cells were not able to demonstrate significant expression of exogenous IL-2 (i.e. the transgene or transgene-carrying cells) in tumor biopsies or blood at different times. Therefore, further studies were performed to evaluate the mechanism(s) involved in the rapid disappearance of xenogenic carrier cells in more detail. We show here that significant in vitro cytotoxicity against transgene-carrying Vero cells can be observed in peripheral blood of all the patients before treatment as well as in healthy controls. “Cold” target inhibition shows that significant killing of Vero-IL2 cells is mediated by natural killer (NK) cells. This was confirmed by showing that established CD3−/CD16 + /CD56 + peripheral blood NK cell clones kill both K562 and Vero-IL2 target cells. The failure of other mechanisms (complement, antibody-dependent cell cytotoxicity or cytotoxic T lymphocytes) to destroy xenogenic, histoincompatible Vero cells in vitro suggests that NK cells also might be responsible for the killing of Vero-IL2 in vivo and for the failure to detect the transgene at the application site. These results might also be of importance for some aspects of the current discussion of xenotransplantation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0730-2312
    Keywords: lymphocytes ; activation ; cytokines ; cytokine gene transcription ; glutamine ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Glutamine is required for the proliferation of lymphocytes, but quantitative effects on discrete steps of activation remain unknown to date. Therefore the influence of glutamine (range: 0 mM-1 mM) on the in vitro response of human peripheral blood mononuclear cells (PBMC) to a mitogenic anti-CD3 monoclonal antibody (mAb) was investigated. Expression of surface activation markers by flow cytometry, presence of mRNA of cytokine genes by polymerase chain reaction, release of cytokines by ELISA, and entering into the cell cycle by flow cytometry were sequentially analyzed. Proliferation was measured by a 3H-thymidine incorporation assay.mRNA coding for IL-2, IL-2 receptor, IL-4, IL-5, GM-CSF, and IFN-γ was detectable independently from exogenous glutamine provision; expression of the cell surface activation marker CD69 was also glutamine independent. In contrast, later activation events including the expression of the surface activation markers CD25, CD45RO, and CD71 as well as the production of IFN-γ were found to require exogenous glutamine supply. In contrast, production of TNF-α could be observed in the absence of glutamine and was increased to a limited extent by exogenous glutamine. The overall lymphocyte response as reflected by entering into the cell cycle and proliferation was directly correlated with the glutamine concentration of the culture medium. Efficient progression through the cell cycle was found to require at least 0.5 mM glutamine and an increase in glutamine concentration from 0.1 mM to 1 mM enhanced proliferation by 50%. These results were supported by data obtained following anti-CD3 stimulation of a CD4+ T cell clone. Altogether, these data underline that a complete cellular immune response depends on an exogenous glutamine supply. Regarding glutamine requirements, they define early, glutamine-independent and late, glutamine-dependent lymphocyte activation stages.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...