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  • 1
    ISSN: 1365-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Macrophages play a role in the host defence against cancer. Little is known about changes in macrophage populations during early metastatic growth. To evaluate the distribution, number and phenotype of macrophages in the development of hepatic metastases in a rat model (Wag/Rij rats and syngeneic CC531 colon carcinoma cell line), an immunohistochemical study was performed with the monoclonal antibodies ED1 (monocytes, and all macrophages), ED2 (resident tissue macrophages, like Kupffer cells) and ED3 (a subpopulation of macrophages which may play a role in the recruitment of lymphocytes). OX19 and Hisl4 were used to identify lymphocytes. In this study a new monoclonal antibody CC52 is described, which recognizes the CC531 tumour cell line. Liver metastases were induced by injection of CC53I colon carcinoma cells into a mesenteric vein. Rats were killed at various intervals. Results show three major macrophage populations during hepatic tumour growth: (1) on day 3, infiltrates are observed around the micrometastases, which contain mainly newly recruited macrophages (ED1+ and ED2−); (2) after 7 days, ED3-positive (ED3 +) macrophages together with T lymphocytes are found in the infiltrates; (3) an increase in the number of ED2-positive (ED2+) Kupffer cells is observed in the liver parenchyma after 14 days. In conclusion, the present results suggest that various populations of macrophages, newly recruited (ED1+) as well as resident Kupffer cells (ED2+), are involved in the immune response against tumour cell deposits in the liver.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1432-0851
    Schlagwort(e): Liposomes ; (Dichloromethylene)bisphosphonate ; Kupffer cells ; Metastatic growth ; Liver
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The evidence that Kupffer cells are capable of controlling metastatic growth in the liver in vivo is largely circumstantial. The best approach when studying natural cytotoxicity activities of Kupffer cells is to investigate the effect of Kupffer cell elimination on tumour growth. Until now it has not been possible to eliminate Kupffer cells without affecting other cell populations. We have recently developed a new method to eliminate Kupffer cells selectively: intravenous injection of liposome-encapsulated (dichloromethylene)bisphosphonate (Cl2MDP-liposomes) leads to effective elimination of all Kypffer cells, without affecting non-phagocytic cells. Wag/Rij rats were injected with Cl2MDP-liposomes. After 48 h, rats were inoculated with syngeneic CC531 colon carcinoma cells by injection in the portal system. The results show a strongly enhanced tumour growth in the liver of the Cl2MDP-liposometreated rats. In these animals, livers were almost completely replaced by tumour and had increased in weight, whereas in the control groups only a few (four to eight) small (1-mm) tumour nodules were found. These data show that selective elimination of Kupffer cells results in enhanced tumour growth in the liver, implying that Kupffer cells play a crucial role in controlling tumour growth in the liver.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1432-0851
    Schlagwort(e): Kupffer cell ; Human granulocyte/macrophage-colony-stimulating factor ; Interferon γ ; Cytotoxicity ; SW948 ; Tumor necrosis factor α
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In this study we investigated the effect of the cytokines human granulocyte/macrophage-colony-stimulating Factor (hGM-CSF) and interferon γ (IFNγ) on human Kupffer-cell-mediated cytotoxicity against the SW948 coloncarcinoma cell line. Kupffer cells were isolated from small liver wedge biopsies, taken from 14 patient who had had abdominal surgery for colon carcinoma or partial hepatectomy. The cells were incubated with hGM-CSF (100 ng/ml), or with IFNγ (100 U/ml) or with their combination and the perecentage cytotoxicity was determined using a recently described modified assay. Additional experiments were performed with tumour-necrosis-factor-α(TNFα)-sensitive U937 cells as target. The TNFα secretion of Kupffer cells was measured and we evaluated the effect of TNFα on colon tumour targets. We performed human-Kupffer cell-mediated cytotoxicity blocking experiments with anti-TNFα and used paraformaldehydefixed Kupffer cells to demonstrate lysis of TNFα-sensitive WEHI-164 cells and of SW948 cells. The overall cytotoxicity against SW948 caused by unactivated Kupffer cells (n=14), and by Kupffer cells activated with hGM-CSF (n=14), IFNγ (n=6) or their combination (n=6) was respectively: 19.5±2.6%, 25.3±2.9% 41±9.4% and 45.6±8% at E/T=1 and 28.2±2.9%, 35.6±3.2%, 55.6±9.7% and 62.8% at E/T=5. All differences were statistically significant (P〈0.05). No growth-promoting activity by hGM-CSF on the SW948 tumour cells was observed. U937 cells were highly susceptible to Kupffer-cell-mediated cytotoxicity. The TNFα secretion by human Kupffer cells increased in parallel to their cytotoxicity after incubation with these cytokines. Soluble TNFα had only a slight anti-proliferative effect on SW948 cells, while specific anti-TNFα blocked Kupffer cell cytotoxicity by up to 80%. Finally, paraformaldehyde-fixed Kupffer cells were able to lyse WEHI-164 and SW948 cells. This indicates that expression of cell-associated TNFα is the main cytolytic mechanism of human-Kupffer-cell-mediated cytotoxicity. The implications for the use of hGM-CSF and IFNγ in vivo are discussed.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1432-0851
    Schlagwort(e): Key words: Kupffer cell  –  Human granulocyte/macrophage-colony-stimulating factor  –  Interferon γ –  Cytotoxicity  –  SW948  –  Tumor necrosis factor α
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. In this study we investigated the effect of the cytokines human granulocyte/macrophage-colony-stimulating Factor (hGM-CSF) and interferon γ (IFNγ) on human Kupffer-cell-mediated cytotoxicity against the SW948 coloncarcinoma cell line. Kupffer cells were isolated from small liver wedge biopsies, taken from 14 patients who had had abdominal surgery for colon carcinoma or partial hepatectomy. The cells were incubated with hGM-CSF (100 ng/ml), or with IFNγ (100 U/ml) or with their combination and the percentage cytotoxicity was determined using a recently described modified assay. Additional experiments were performed with tumour-necrosis-factor-α(TNFα)-sensitive U937 cells as target. The TNFα secretion of Kupffer cells was measured and we evaluated the effect of TNFα on colon tumour targets. We performed human-Kupffer-cell-mediated cytotoxicity blocking experiments with anti-TNFα and used paraformaldehyde-fixed Kupffer cells to demonstrate lysis of TNFα-sensitive WEHI-164 cells and of SW948 cells. The overall cytotoxicity against SW948 caused by unactivated Kupffer cells (n = 14), and by Kupffer cells activated with hGM-CSF (n = 14), IFNγ (n = 6) or their combination (n = 6) was respectively: 19.5±2.6%, 25.3±2.9%, 41±9.4% and 45.6±8% at E/T = 1 and 28.2±2.9%, 35.6±3.2%, 55.6±9.7% and 62.8% at E/T = 5. All differences were statistically significant (P 〈0.05). No growth-promoting activity by hGM-CSF on the SW948 tumour cells was observed. U937 cells were highly susceptible to Kupffer-cell-mediated cytotoxicity. The TNFα secretion by human Kupffer cells increased in parallel to their cytotoxicity after incubation with these cytokines. Soluble TNFα had only a slight anti-proliferative effect on SW948 cells, while specific anti-TNFα blocked Kupffer cell cytotoxicity by up to 80%. Finally, paraformaldehyde-fixed Kupffer cells were able to lyse WEHI-164 and SW948 cells. This indicates that expression of cell-associated TNFα is the main cytolytic mechanism of human-Kupffer-cell-mediated cytotoxicity. The implications for the use of hGM-CSF and IFNγ in vivo are discussed.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-119X
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary On light microscopical (LM) level dendritic cells (DC) isolated from lymphoid organs can be discriminated from macrophages (Mø) by the presence of acid phosphatase (APh) activity in a spot near the nucleus and constitutional expression of class II antigens. The aim of our study was to investigate whether DC and monocytes (Mo) enriched from human peripheral blood could be discriminated on the electron microscopical (EM) level. Therefore we developed a triple method by which we compared the presence of myeloperoxidase (MPO) containing vesicles, the localization of APh containing vesicles and expression of MHC class II and RFD1 (a DC-associated class II-like antigen) plasmamembrane antigens. DC, functionally characterized as potent stimulators in a MLR, are MPO-negative, whereas Mo show MPO in cytoplasmic granules. Although both DC and Mo show little APh activity at LM level, both types of cells show APh activity at the EM level but at different locations. In DC APh containing vesicles are present in a distinct juxtanuclear area, in contrast to Mo, which show APh activity in lysosomes scattered throughout the whole cytoplasm. Moreover, on both LM and EM level, DC are strongly class II positive, whereas Mo show variable labelling intensity for class II, while RFD1 was only found on DC.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1432-0584
    Schlagwort(e): “Leukemic” HLTBMC's ; Adhesion molecules
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Human long-term bone marrow cultures (HLTBMCs) were established with bone marrow samples collected from 15 patients with acute myeloid leukemia (AML) and compared with HLTBMCs from eight healthy volunteers. During 6 weeks of culture, the cellular composition of HLTBMCs was quantitatively studied. The cells of the HLTBMCs were divided into three main categories: fibroblasts, macrophages, and ‘other cells’ (endothelial cells, hematopoietic cells and undefined cells). HLTBMCs derived from healthy volunteers demonstrated a very consistent development. The number of fibroblasts increased during culture and the number of macrophages decreased, resulting in a steady state after 3 weeks of culture. In contrast, HLTBMCs derived from patients with AML showed a strikingly different pattern of irregular development and a steady state was not reached under our conditions. The APAAP technique was used to demonstrate expression of adhesion molecules. VLA2, VLA5, VLA6, LFA1, Mac1, p150/95, β2-chain, HCAM, ICAM1, NCAM, and VCAM1 were more expressed on ‘normal’ as compared with ‘leukemic’ bone marrow stromal cells, although this reached significance only for β2-chain and NCAM. VLA1, 3, and 4 were expressed in a higher percentage on ‘leukemic’ stroma (not significant). More expression was seen on ‘normal’ as opposed to ‘leukemic’ macrophages for the adhesion molecules tested, except for VLA5. The differences reached significance for the majority of molecules tested. It is concluded that striking differences exist in cellular composition and adhesion molecule expression between HLTBMCs from healthy individuals and those from patients with AML. This may have an impact on the pathogenesis of AML.
    Materialart: Digitale Medien
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  • 7
    ISSN: 1432-2218
    Schlagwort(e): Key words: Cytotoxicity — Interleukin 6 — Laparoscopic surgery — Monocyte — SW 948
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: Experimental animal research shows that immunologic defenses against tumor cells are disturbed by surgical trauma, resulting in an increased rate of tumor implantation and the growth of subsequent metastases. Minimally invasive surgery is associated with a preservation of postoperative immunologic functions and, in animal models, with decreased tumor growth. The objective was to study the influence of several surgical procedures, approached conventionally and laparoscopically, on interleukin-6 (IL-6) and monocyte-mediated cytotoxicity (MMC). Methods: Five groups of five patients each were included in this prospective study: laparoscopic cholecystectomy (minor trauma) group, Nissen fundoplication (laparoscopic and conventional as moderate trauma) groups, and sigmoid colectomy (laparoscopic and conventional as major trauma) groups. Preoperatively, 1 and 4 days after surgery, IL-6 and MMC against SW948 colon cancer cell line were determined. Results: The IL-6 levels differed significantly between the three laparoscopic procedures (p= 0.004) and increased according to the degree of trauma. There was no significant difference in MMC between the three laparoscopic procedures. However, MMC was suppressed after conventional procedures and preserved after laparoscopic procedures (p= 0.001). There was no correlation between IL-6 levels and changes in MMC. Conclusions: More extensive laparoscopic procedures induce increased levels of IL-6, reflecting higher levels of trauma. Conventional surgical procedures result in depressed MMC in the postoperative period. After laparoscopic procedures, MMC is preserved. These findings may be of importance in preventing implantation and growth of cancer cells spread by surgical manipulation.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Surgical endoscopy and other interventional techniques 14 (2000), S. 812 -816 
    ISSN: 1432-2218
    Schlagwort(e): Key words: CD11b — Laparoscopic surgery — Leukocyte — Oxidative burst — Phagocytosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: Laparoscopic surgery is thought to result in a better preservation of patients' immunological defenses. Polymorphonuclear leukocytes (PMN) are the most important effector cells in the elimination of pathogenic microorganisms. Because little is known about their function after laparoscopic surgery, we studied PMN phagocytosis, antigen expression, and oxygen radical production. Methods: In this study, 17 patients scheduled for Nissen fundoplication were randomly assigned to undergo either a laparoscopic or conventional procedure. To study phagocytic capacity, PMN were incubated with fluorescein isothiocyanate (FITC)-labeled Staphylococcus aureus. Plasma opsonic capacity was measured by comparing PMN phagocytosis in the presence of patients' own plasma with phagocytosis in the presence of control plasma. Cellular activation was measured by the expression of various cell surface markers and by assessment of PMA-stimulated oxidative burst. Results: Phagocytosis by PMN in the presence of patients' plasma was significantly lower 2 h after the conventional operation. No decrease in phagocytosis was observed when control plasma was used, indicating a decreased opsonic capacity of plasma after conventional surgery. No changes were observed after laparoscopic surgery. Furthermore, CD11b expression was significantly lower after the laparoscopic approach, indicating a blunted cellular activation. A significantly lower PMA-stimulated oxidative burst further confirmed the tempered stimulation after laparoscopic surgery. Conclusions: Laparoscopic surgery results in a preservation of the plasma opsonic capacity, and thereby the ability of PMN to phagocytose bacteria. Moreover, the postoperative cellular activation is reduced. The preserved phagocytosis and the blunted activation may prevent the development of postoperative infectious complications.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 121 (1973), S. 369-374 
    ISSN: 1617-4623
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Two genes involved in the enzymatic conversion of D-alanine to pyruvate are described, alnA and alnR. The alnA gene, located between ara and leu, is probably the structural gene for alaninase. The alnR gene, which can be cotransduced with thr but not with leu, could be demonstrated to be a regulatory gene with the aid of a mutation resulting in permanent repression and a thermosensitive revertant of this mutation restoring inducibility at 28°C, but not at 42°C.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Langenbeck's archives of surgery 384 (1999), S. 250-258 
    ISSN: 1435-2451
    Schlagwort(e): Key words Laparoscopic surgery ; Systemic immune response
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: Immune suppression is an established consequence of surgical stress and trauma. Postoperative changes in the systemic immune system are proportional to the degree of surgical trauma and subsequent immune suppression may be implicated in the development of infectious complications and tumor metastasis formation. Laparoscopic surgery reduces the magnitude of the operative trauma and is thought to preserve postoperative immunological defenses. Methods: Relevant literature concerning postoperative immune functions and laparoscopic surgery was reviewed and clinical implications are discussed. Results: The influence of laparoscopic surgery on the postoperative systemic immune response is significantly less after laparoscopic cholecystectomy than with the conventional approach. Few immunological data are available concerning more advanced laparoscopic procedures. Various animal model studies of postoperative septic complications and tumor growth show that the postoperative preservation of the systemic immune response after laparoscopic surgery can have enormous clinical advantages. Conclusion: Laparoscopic surgery preserves the postoperative immunological defenses. In the future, this may imply a lower number of infections, less local recurrence and even fewer distant metastases. Prospective randomized studies are necessary to see whether these suspected advantages can be demonstrated in clinical practice.
    Materialart: Digitale Medien
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