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  • 1
    ISSN: 1600-065X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary: This article reviews our immunotherapy research with natural killer (NK) cells in a syngeneic rat colorectal cancer liver and lung metastasis model. Using adoptive transfer of interleukin (IL)-2-activated NK cells, NK cells were shown to selectively infiltrate the tumors. More NK cells were found in tumors when the NK cells were directly injected into tumor-draining blood vessels than when the cells were injected in systemic blood vessels. Under optimal conditions, a limited, though significant, effect of adoptively transferred NK cells on tumor growth was shown. We observed that both endogenous and adoptively transferred NK cells were predominantly present in the stroma surrounding the tumor cell nodules. It is possible that they did not penetrate the nodules containing the tumor cells because of the presence of a basal membrane-like structure around these nodules. Adoptively transferred NK cells may initiate elimination of tumor cells by activating other effector cells, whereas some may eliminate tumor cells by direct cell–cell contact. A diverse array of molecules was shown to be involved in this process. CD45 on NK cells was found to be important in initiating the lysis-inhibitory signal upon binding of ‘self’ major histocompatibility complex (MHC) class I on potential target cells. Our results indicate that NK-cell cancer therapy is still promising and needs improvement.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé L'importance relative des facteurs pronostiques dans les cancers papillaires et folliculaires de la thyroïde ont été étudiés chez 113 patients selon le modèle de Cox. Voici les facteurs de pronostic étudiés: histologie, degré de différentiation, extension extrathyroïdienne, envahissement ganglionnaire, présence de métastase à distance au moment du diagnostic, contenu nucléaire en ADN, âge au moment du diagnostic, et sexe. Le contenu d'ADN nucléaire était mesuré dans les tumeurs primitives par la cytométrie de flux. La thyroïdectomie totale suivie d'I 131 était le traitement standard. Les résultats montraient que le contenu nucléaire en ADN était en corrélation significative avec le type histologique et le degré de malignité dans les cancers papillaires. La présence de métastases à distance était de loin le facteur pronostique le plus important. Dans le groupe de patients sans métastases (n=91), la présence de polyploïdie (c'est-à-dire 2 chaînes aberrantes ou plus) était le facteur pronostique significatif pour la survie globale. Pour la survie sans maladie, la polyploïdie venait après le facteur âge. Dans le groupe présentant des métastases à distance (n=22), tous les patients avec tumeurs polyploïdes sont morts pour huit patients de ceux qui avaient des tumeurs à ploïdie différente. Mais le petit nombre de patients de ce groupe interdit de considérer ces résultats comme significatifs. Cette étude démontre que le contenu nucléaire en ADN est un facteur pronostique chez les patients ayant un cancer papillaire et folliculaire sans métastases au moment du diagnostic.
    Abstract: Resumen La importancia relativa de los factores de pronóstico en el cancer papilar y folicular de la glándula tiroides fue estudiada en 113 pacientes utilizando el modelo de riesgos proporcionales de Cox. Los factores de pronóstico analizados fueron: histologia, grado tumoral, crecimiento extratiroideo, extension ganglionar, metastasis distantes en el momento del diagnóstico, contenido nuclear de DNA, edad en el momento del diagnóstico, y sexo. El contenido nuclear de DNA fue determinado en tumores primarios mediante citometn'a de flujo. El tratamiento estandar fue la tiroidectomía total y la ablación postoperatoria con131I. Los resultados muestran que el contenido nuclear de DNA se correlaciona en forma significativa con el tipo histológico y en el cancer papilar también con el grado tumoral. La presencia de metastasis distantes en el momento del diagnóstico es, muy ampliamente, el más importante factor de pronóstico. En el grupo de pacientes libre de metastasis distantes (n=91), la multiploidia (i.e., presencia de 2 o más lineas primitivas aberrantes) aparece como el único factor de significatión en cuanto a supervivencia global. Respecto a supervivencia libre de enfermedad la multiploidia aparece como segundo factor, después de la edad. En el grupo de pacientes con metástasis distantes (n=22) todos los 6 pacientes con tumores multiploides murieron, en comparación con 8 (50%) de 16 de aquellos con tumores con cualquier otro tipo de ploidia. Sinembargo, el pequeno número que constituye este grupo impide derivar resultados de signification. El presente estudio demuestra que el contenido nuclear de DNA es un factor pronóstico en pacientes con cancer tiroideo papilar y folicular libres de metastasis distantes.
    Notes: Abstract The relative importance of prognostic factors in papillary and follicular thyroid cancer was studied in 113 patients using Cox's proportional hazards model. Prognostic factors studied were: histology, tumor grade, extrathyroidal growth, nodal involvement, distant métastases at diagnosis, nuclear DNA content, age at diagnosis, and sex. Nuclear DNA content was measured in primary tumors by flow cytometry. Total thyroidectomy and postoperative131I ablation was the standard treatment. The results showed that nuclear DNA content correlated significantly with histologic type and, in papillary cancer, also with tumor grade. The presence of distant metastases at diagnosis was, by far, the most important prognostic factor. In the patient group without distant metastases (n=91), multiploidy (i.e., presence of 2 or more aberrant stemlines) was the only significant prognostic factor for overall survival. With respect to diseasefree survival, multiploidy was second only to the age factor. In the patient group with distant métastases (n=22), all 6 patients with multiploid tumors died compared to 8 (50%) of 16 of those with other ploidy tumors. However, the small number in this group precluded significant results. The present study demonstrates that nuclear DNA content is a prognostic factor in those patients with papillary and follicular thyroid cancer without distant metastases at diagnosis.
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  • 3
    ISSN: 1432-0851
    Keywords: Lymphokine-activated killer activity ; 2-Mercaptoethanol ; Indomethacin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The role of 2-mercaptoethanol and indomethacin in the induction of lymphokine-activated killer (LAK) activity by interleukin-2 (IL-2) in rat splenocyte cultures was investigated. Spleens from 4-month-old male rats of five different strains were tested. Splenocytes were cultured for 3–5 days in the presence of IL-2 (1000 U/ml) and LAK activity was assessed by 4-h51Cr release assays with P815 and YAC-1 cells as targets. LAK activity could be induced by IL-2 in splenocytes from all rat strains, but only when 2-mercaptoethanol was present in the culture medium. Optimal LAK activity was induced when the 2-mercaptoethanol concentration in splenocyte cultures was at least 5 µM. Different rat strains showed differences in levels of in vitro induction of LAK activity. In the presence of 2-mercaptoethanol the level of LAK activity induced by IL-2 was high in BN and Lewis rats, intermediate in Wistar and Wag rats, and low in DZB rats. In the absence of 2-mercaptoethanol no or minimal LAK activity was induced. Furthermore we observed that addition of 50 µm indomethacin to the culture medium in the presence of 2-mercaptoethanol augmented the induction of LAK activity to some extent. In the absence of 2-mercaptoethanol, addition of indomethacin resulted only in low levels or no induction of LAK activity. We conclude that for optimal induction of LAK activity by IL-2 in rat splenocyte cultures 2-mercaptoethanol is essential, while indomethacin can only marginally further improve this induction.
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  • 4
    ISSN: 1432-0851
    Keywords: Bispecific monoclonal antibody ; Lymphokine-activated killer cell ; Rat ; CD8
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In vivo targeting of lymphokine-activated killer (LAK) cells to tumour deposits by bispecific monoclonal antibodies (bimAb) may be a way to improve adoptive immunotherapy. We developed a bimAb against adherent LAK (ALAK) cells and colon tumour CC531 in Wag rats. The bimAb was produced by somatic hybridization of two mouse hybridomas, one producing monoclonal antibodies (mAb) against CD8 (IgG2b, OX8), and the other producing mAb against a CC531-associated antigen (IgG1, CC52). A bimAb-producing clone was selected by an enzyme-linked immunosorbent assay with CC531 tumour cells. BimAb were purified from ascitic fluid by protein A affinity chromatography. Each of five pooled peak fractions was analysed by flow cytometry for the presence of bimAb. Most bimAb were found in a fraction that was eluted at pH 4.5 from protein A. FPLC analysis of this fraction revealed that no parental antibodies were present. The OX8 × CC52 bimAb greatly increased conjugate formation in vitro between ALAK cells and CC531. Results of51Cr-release assays with CC531 as target cells and ALAK cells as effector cells were not significantly different in the presence or in the absence of the bimAb. The methods we used here, a cell enzyme-linked immunosorbent assay and flow cytometry, are simple methods for development and purification of a bimAb when a functional selection method is not a priori available. The OX8 × CC52 bimAb we developed this way may increase in vivo tumour targeting of ALAK cells and thus augment antitumour effect in vivo.
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  • 5
    ISSN: 1432-0851
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previous experiments in a syngeneic rat liver tumor model using the colon adenocarcinoma CC531 demonstrated that injection of interleukin-2 (IL-2) induced significant antitumor responses. Furthermore, it was found that this treatment strategy was accompanied by an increase in the number of natural killer (NK) cells in and around the tumor. In the present study, the role of endogenous NK cells in IL-2-mediated antitumor responses was further elucidated by depleting tumor-bearing rats of NK cells, using the anti-CD161A mouse IgG1 antibody 3.2.3. Rats were depleted either after or prior to tumor induction and subsequently treated with IL-2. The results demonstrated that depletion of NK cells in tumor-bearing rats did not influence IL-2-induced antitumor effects. In addition, injection of IL-2 in NK-cell-depleted rats induced repopulation of NK cells in the peripheral blood from 3 days on and further after the last injection with IL-2. Therefore, the possibility cannot be excluded that de novo recruited NK cells play a role in attaining IL-2 mediated antitumor effects, but NK cells, which were present before or during the start of IL-2 therapy, were not relevant.
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  • 6
    ISSN: 1432-0851
    Keywords: Lymphokine-activated killer activity ; Interleukin-2 ; 2-Mercaptoethanol ; Macrophages/monocytes ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the present study we investigated the inhibition of interleukin-2(IL-2)-induced lymphokine-activated killer (LAK) activity in rat splenocyte cultures in relation to the presence of 2-mercaptoethanol and macrophages/monocytes. The presence of 2-mercaptoethanol is necessary for induction of LAK activity in rat splenocyte cultures. Removal of macrophages/monocytes from rat splenocytes by plastic or nylon-wool adherence, or iron ingestion resulted in LAK induction by IL-2 in the absence of 2-mercaptoethanol. The effect of macrophages/monocytes on LAK activity was also studied in transwell co-cultures. In the absence of 2-mercaptoethanol, the induction of LAK activity was very low in macrophage/monocyte-depleted splenocytes with macrophages/monocytes in the upper compartment of a transwell culture. In contrast, in the presence of 2-mercaptoethanol a high level of LAK activity was induced in these transwell cultures, showing that 2-mercaptoethanol abolished the LAK-inhibiting capacity of macrophages/monocytes. In addition, established LAK activity was strongly inhibited when, after LAK induction, splenocytes were cultured with supernatant of unfractionated splenocytes, which were cultured with IL-2 but in the absence of 2-mercaptoethanol. Addition of 2-mercaptoethanol abrogated the inhibiting effect of the supernatant completely. These experiments demonstrate that rat macrophages/monocytes produce 2-mercaptoethanolsensitive soluble LAK-inhibiting factors. Ultrafiltration of conditioned culture medium of macrophages/monocytes revealed the presence of LAK-inhibiting factors larger than 10 kDa. We concluded that 2-mercaptoethanol-sensitive soluble factors produced by macrophages/monocytes determine the level of LAK induction in rat splenocyte cultures.
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  • 7
    ISSN: 1432-0851
    Keywords: Key words: Lymphokine-activated killer activity – Interleukin-2 – 2-Mercaptoethanol – Macrophages/monocytes – Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. In the present study we investigated the inhibition of interleukin-2(IL-2)-induced lymphokine-activated killer (LAK) activity in rat splenocyte cultures in relation to the presence of 2-mercaptoethanol and macrophages/monocytes. The presence of 2-mercaptoethanol is necessary for induction of LAK activity in rat splenocyte cultures. Removal of macrophages/monocytes from rat splenocytes by plastic or nylon-wool adherence, or iron ingestion resulted in LAK induction by IL-2 in the absence of 2-mercaptoethanol. The effect of macrophages/monocytes on LAK activity was also studied in transwell co-cultures. In the absence of 2-mercaptoethanol, the induction of LAK activity was very low in macrophage/monocyte-depleted splenocytes with macrophages/monocytes in the upper compartment of a transwell culture. In contrast, in the presence of 2-mercaptoethanol a high level of LAK activity was induced in these transwell cultures, showing that 2-mercaptoethanol abolished the LAK-inhibiting capacity of macrophages/monocytes. In addition, established LAK activity was strongly inhibited when, after LAK induction, splenocytes were cultured with supernatant of unfractionated splenocytes, which were cultured with IL-2 but in the absence of 2-mercaptoethanol. Addition of 2-mercaptoethanol abrogated the inhibiting effect of the supernatant completely. These experiments demonstrate that rat macrophages/monocytes produce 2-mercaptoethanol-sensitive soluble LAK-inhibiting factors. Ultrafiltration of conditioned culture medium of macrophages/monocytes revealed the presence of LAK-inhibiting factors larger than 10 kDa. We concluded that 2-mercaptoethanol-sensitive soluble factors produced by macrophages/monocytes determine the level of LAK induction in rat splenocyte cultures.
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  • 8
    ISSN: 1432-0843
    Keywords: Key words Drug resistance ; Melphalan ; Extrahepatic organs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: Glutathione (GSH) plays an important role in the resistance of tumors to cytostatics. Therefore, depletion of GSH by the GSH synthesis inhibitor buthionine sulfoximine (BSO) has been proposed to enhance the efficacy of certain anticancer agents. We studied the effect of BSO in rats bearing intrahepatically implanted tumors of the CC531 colorectal cancer cell line on the antitumor activity of melphalan (L-PAM). Since these liver tumors tend to derive most of their blood supply from the hepatic artery, we evaluated whether delivery of BSO into the hepatic artery would more selectively decrease GSH levels in the implanted tumor tissue as compared with normal liver and extrahepatic tissues. Methods: Tumor-bearing rats were treated with a 24-h continuous infusion of 0.375 mmol/kg BSO via the jugular vein, immediately followed by a bolus L-PAM (15 μmol/kg; 4.5 mg/kg) infusion via the hepatic artery. Laparotomy was performed on day 14 and 28 after treatment for measurement of the liver tumors. For the evaluation of locoregional administration of BSO, a 24-h continuous infusion of 0.375 mmol/kg BSO was delivered into either the hepatic artery, the portal vein, or the jugular vein in freely moving rats and GSH levels in the tumor, liver, kidney, lung, heart, bone marrow, and blood were measured. Results: BSO infusion via the jugular vein increased the antitumor efficacy of L-PAM injected into the hepatic artery 2-fold as determined at 14 days after treatment. Although infusion of BSO via the hepatic artery depleted GSH more severely in the tumor as compared with jugular vein or portal vein administration, the additional effect was only slight (10%). No difference was observed in any other tissue. Conclusion: GSH depletion increased the cytostatic efficacy of L-PAM 2-fold in vivo as determined at 14 days after treatment. Hepatic artery infusion of BSO translated into a statistically significant, but probably not therapeutically relevant, increase in tumor GSH depletion as compared with the other routes of BSO administration.
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  • 9
    ISSN: 1432-0843
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To enable the treatment of hepatic metastasis with higher, theoretically more effective, doses of systemically toxic anticancer drugs, an isolated liver perfusion (ILP) technique was developed in WAG/Ola rats. First, in a toxicity study the maximally tolerated dose (MTD) of mitomycin C (MMC) was determined for a 25-min ILP and for hepatic artery infusion (HAI) after the administration of a bolus dose. The MTD in the ILP setting (4.8 mg/kg) was 4 times that using HAI (1.2 mg/kg). Subsequently, in a rat colorectal hepatic-metastasis model, concentrations of MMC in tumour, liver, plasma and perfusate were measured during a 25-min ILP to investigate the expected pharmacokinetic advantage of ILP. The mean plasma level determined after ILP (1.2 as well as 4.8 mg/kg MMC) was significantly lower (P〈0.001) than that obtained following HAI. This may explain both the absence of severe systemic toxicity and the higher MTD in ILP-treated groups. No significant difference in mean tumour and liver tissue concentrations of MMC were found when the groups treated with 1.2 mg/kg drug via HAI vs ILP were compared. The mean MMC concentration in tumour tissue was significantly higher (almost 5 times;P〈0.05) in rats treated by ILP with the MTD (4.8 mg/kg) than in those treated via HAI with the MTD (1.2 mg/kg). ILP of MMC can be safely performed using a dose 4 times higher than the MTD in the HAI setting, leading to an almost 5-fold concentration of MMC in hepatic metastasis. ILP of MMC may therefore represent a promising therapy for metastasis confined to the liver.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Breast cancer research and treatment 8 (1986), S. 189-196 
    ISSN: 1573-7217
    Keywords: breast cancer ; pathologic features ; prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a selected group of 207 breast cancer patients with tumor-free axillary nodes, clinical and pathological features were evaluated as to their relationship to long-term disease-free survival. No clinical feature was found to be prognostically useful. Of pathologic features studied, four appear to have significance. These are (1) the volume of the primary mass, (2) the histologic or nuclear grade, (3) the presence of invasive lobular carcinoma in the primary mass, and possibly (4) the presence of neoplastic cells in intramammary lymphatic vessels. When two or more of these four features are present, prognosis is less favorable than when there is only one, but the influences are not arithmetically additive.
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