| 51. |
- Liu, D. L, et al.
(författare)
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Tumour vessel damage resulting from laser-induced hyperthermia alone and in combination with photodynamic therapy
- 1997
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Ingår i: Cancer Letters. - 1872-7980. ; 111:1-2, s. 157-165
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Tidskriftsartikel (refereegranskat)abstract
- This study examined tumour vessel injury resulting from laser-induced hyperthermia alone and in combination with photodynamic therapy (PDT) in the treatment of rat liver tumours by means of scanning electron microscopy. A total of 18 Wistar rats were divided into three groups, Group I (six animals) underwent hyperthermia for 15 min (15-min hyperthermia). Group II (six animals) underwent hyperthermia for 30 min (30-min hyperthermia). Group III (six animals) received the combined treatment of PDT and 30-min hyperthermia. For PDT, delta-amino laevulinic acid at a dose of 60 mg/kg of body weight was intravenously administered 60 min before irradiation at 635 nm. The morphological results indicated that 15-min hyperthermia gave rise to an increase in permeability of the vessels in the treated tumour. Thirty-min hyperthermia caused extreme oedema of vascular endothelial cells and restrictive openings of tumour branch vessels. The combined therapy of PDT and hyperthermia destroyed tumour vasculature. Large breaks of the inner wall of the treated tumour vessels were deeply involved in the basement membrane of the vessel. The results indicate that there may be a close link between inhibition of tumour growth and degree of damage to tumour vessels. (C) 1997 Elsevier Science Ireland Ltd.
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| 52. |
- Måsbäck, A, et al.
(författare)
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Cutaneous malignant melanoma in southern Sweden 1965, 1975, and 1985. Prognostic factors and histologic correlations
- 1997
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Ingår i: Cancer. - 0008-543X. ; 79:2, s. 275-283
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is a worldwide increase in the incidence of cutaneous malignant melanoma (CMM) among whites. In Sweden, a five-fold increase has been recorded since 1960, although the increase in mortality rate is substantially lower. Tumor thickness is recognized as the most important histologic prognostic factor for primary melanoma. In a previous study, the authors did not find any significant decrease in mean tumor thickness over the period 1965-1985 in their region. In the current study, prognostic factors for melanoma were evaluated for this time period.METHODS: In a population-based study, 468 cases of invasive melanoma, diagnosed in the years 1965, 1975, and 1985, were histopathologically reexamined. The level of invasion, tumor thickness, regressive reaction, ulceration, presence of inflammatory cells, presence of benign nevus cells, and site of presentation were studied. In 461 of these 468 patients, it was possible to correlate the histopathologic factors with survival.RESULTS: In univariate analyses, the parameters of presence of ulceration, increasing tumor thickness, male gender, nodular type of melanoma, and older age at diagnosis were significantly related to a shortened overall survival. In various multivariate models with adjustment for age and the factors studied simultaneously, ulceration, increasing tumor thickness, and male gender were significantly associated with a poor prognosis. Correlations between the factors studied were noted. It was observed that older patients tended to have thicker tumors. Thick melanomas correlated to a deeper level of invasion (Clark's), nodular growth pattern, ulceration, less inflammation, and less regression compared with thin, less invasive melanomas. Women had significantly fewer inflammatory cells and fewer signs of regression in their tumors compared with men.CONCLUSIONS: In multivariate analyses adjusted for age, increasing tumor thickness, older age, ulceration, and male gender were significantly associated with a poor prognosis among patients with invasive CMM. None of these factors showed a significant change for the years 1965, 1975, and 1985. Thus, a change in the prognostic factors studied does not explain the increased survival of melanoma patients for this time period.
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| 53. |
- Möller, Fáll Helgi, et al.
(författare)
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Angiogenesis inhibitor TNP-470 augments the effect of repeated arterial ischemia on growth but does not affect take in a rat liver tumor model
- 1997
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Ingår i: Anticancer research. - 0250-7005. ; 17:4 A, s. 2401-2406
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Tidskriftsartikel (refereegranskat)abstract
- Transient hepatic arterial occlusion causes necrosis in solid hepatic tumors in the rat, but regrowth of tumor cells and capillaries takes place from the tumor periphery. It was therefore considered of interest to combine this treatment with the angiogenesis inhibitor TNP-470 (therapeutic model). Wistar rats with a dimethylhydrazine-induced adenocarcinoma implanted into the liver received one of the following treatments: TNP-470 + transient hepatic ischemia, transient hepatic ischemia alone, TNP-470 alone or sham solution alone. Rats were sacrificed one week after the start of treatment. In addition, we investigated if TNP-470 decreases the risk of tumor take in the liver after intraportal injection of viable tumor cells (adjuvant study). Transient hepatic ischemia combined with TNP-470 gave a smaller increase in tumor volume than transient hepatic ischemia (p < 0.01), TNP-470 (p < 0.001) alone or no treatment (p < 0.001). Transient hepatic ischemia or TNP-470 caused a significant suppression of tumor growth when compared to controls (p < 0.01 in both cases). In the adjuvant study, TNP-470 caused retardation of tumor growth (p < 0.01 as compared to controls) but did not affect tumor number. It is concluded that TNP-470 suppressed tumor growth, both alone and in combination with transient hepatic ischemia, but did not affect take of tumor.
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| 54. |
- Nandakumar, Kutty Selva, 1965-, et al.
(författare)
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Early expression of interleukin-12, p40 subunit and IFN-gamma inhibits regression of AK-5 tumor
- 1997
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Ingår i: Cytokines, cellular & molecular therapy. - Abingdon : Taylor & Francis. - 1368-4736 .- 1471-177X. ; 3:4, s. 225-232
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Tidskriftsartikel (refereegranskat)abstract
- Differential immune response of syngeneic animals to a rat histiocytoma AK-5 based on the route of transplantation was investigated. Spontaneous regression of subcutaneous tumor was observed in 55-60% of animals. On the other hand, when the tumor cells were injected intraperitoneally, none of the animals survived. Earlier studies from this laboratory indicated upregulation of Th-1-type cytokines, leading to early tumor regression when the tumor was transplanted subcutaneously. Hence we evaluated and compared the circulatory-cytokine profiles in both s.c. and i.p. tumor-injected animals. Our results show an early increase in the p40 subunit of IL-12, prolific increase in IFN-gamma and lower levels of IL-2 in i.p. tumor-injected animals. However, there were no significant differences in the levels of transcripts for these cytokines in either of the groups. Significantly, a lower level of cytotoxicity was observed with splenocytes from i.p. tumor-transplanted animals. Moreover, the cytotoxicity of IL-12-activated but not IL-2-activated NK cells was inhibited by sera (rich in IL-12, p40 subunit) from i.p. tumor-transplanted animals, suggesting the participation of p40 subunit in the regulation of tumor regression. Thus the present study suggests a possible translational regulation of Th-1-type cytokines in AK-5 tumor-host interaction.
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| 55. |
- Norrback, Karl-Fredrik, et al.
(författare)
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Telomeres and telomerase in normal and malignant haematopoietic cells
- 1997
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Ingår i: European Journal of Cancer. - : Elsevier. - 0959-8049 .- 1879-0852. ; 33:5, s. 774-780
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Tidskriftsartikel (refereegranskat)abstract
- The normal haematopoietic system harbours telomerase-competent cells with a capacity to upregulate the activity to notable levels in a telomere length-independent manner. Strong telomerase activity is found in progenitor stem cells and activated lymphocytes in vitro as well as in vivo, indicating that cells with high growth requirements can readily upregulate telomerase. Despite detection of telomerase activity, a gradual telomere erosion occurs in stem cells and lymphocytes, with significantly shortened telomeres at higher ages, a phenomenon that might be of importance for developing immunosenescence and exhausted haematopoiesis. In malignant haematopoietic disorders telomerase activity is a general finding with large differences in activity levels. The strongest telomerase expression has been shown in acute leukaemias and non-Hodgkin's lymphomas, especially high grade cases. There are indications that the level of activity might parallel tumour progression and be of prognostic relevance, but studies of larger patient materials are needed. An association between the cell cycle and telomerase activity exists, especially for normal haematopoietic cells, and induction of a differentiation programme in immortalised cell lines downregulates telomerase activity. The expression of telomerase activity seems to be regulated at different levels, since for immature bone marrow cells the level of activity seemed to parallel better the phenotype than the proliferation state. The frequent expression of telomerase in leukaemias and lymphomas makes these disorders interesting targets for future anti-telomerase therapy.
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| 56. |
- Ohman, M G, et al.
(författare)
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The influence of zymosan and indomethacin on liver and kidney tumor growth. An experimental study in rats.
- 1997
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Ingår i: Journal of experimental & clinical cancer research : CR. - 0392-9078. ; 16:3, s. 243-7
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Tidskriftsartikel (refereegranskat)abstract
- Zymosan, a non-specific macrophage-stimulating agent, modifies favourably tumour growth in the liver but has minor effect on renal tumours. The mechanism accounting for variation is still to be clarified. The effect of zymosan on liver cancer may be mediated by the macrophage-monocyte system. Kupffer cells are in vitro cytotoxic against colon cancer cell lines. The kidney is sparse in macrophage elements. The prostaglandin synthesis inhibitor, indomethacin, inhibits tumor growth. In Wistar-FU rats inoculated in the liver and the kidney with an adenocarcinoma cell suspension, pretreatment with zymosan (3 mg x 100 g[-1]) significantly reduced both tumour take and liver volume. This effect was attenuated by concomitant administration of indomethacin (0.2 mg x 100 g[-1]). After 2 weeks there was still reduced liver tumour volume. No significant effects on tumour take or growth were observed when the cells were inoculated into the kidney. There was no significant effect of zymosan on an hepatoma in Lister-Hooded rats. Pretreatment with indomethacin had no effect on tumor take or initial growth.
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| 57. |
- Ottesen, Gyda Lola, et al.
(författare)
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DNA ploidy analysis in breast carcinoma. Comparison of unfixed and fixed tissue analyzed by image and flow cytometry
- 1997
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Ingår i: Analytical and Quantitative Cytology and Histology. - 0884-6812. ; 19:5, s. 413-422
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To form a methodologic basis for DNA analysis of ductal carcinoma in situ (DCIS) and invasive carcinoma (IC) of the breast, including very small lesions, by comparison of flow cytometric (FCM) and image cytometric (ICM) methods for DNA quantitation. STUDY DESIGN: The material consisted of 41 DCIS lesions and 26 ICs. FCM DNA analysis of unfixed, frozen samples were compared to (1) FCM of formalin-fixed, paraffin-embedded tissue; (2) ICM of imprints; and (3) ICM of paraffin-embedded tissue sections. RESULTS: FCM of unfixed tissue showed higher DNA measurement precision and a higher number of DNA nondiploid clones as compared to the other three methods. For the classification of DNA diploid/nondiploid cases, high concordance rates were found between the methods. Discordant cases were predominantly DNA neardiploid by FCM of unfixed tissue but DNA diploid by the other methods. The reproducibility of the DNA index (DI) was best in the interval 1.2 < DI < or = 2.2; it was 74% for FCM of fixed tissue and 79% for ICM of imprints. Clones with DI > 3 were found almost exclusively by ICM of imprints. For ICM of tissue sections, DI could not be reliably estimated. By ICM, contrary to FCM, a combined DNA diploid and nondiploid pattern was found frequently. CONCLUSION: Each of the methods has its own advantages and limitations. If possible, FCM should be combined with ICM. FCM of unfixed tissue is superior to the other methods with respect to precise DI estimation. Alternatively, FCM of fixed tissue and ICM of imprints may both give a reliable estimate of DI. ICM of tissue sections can discriminate DNA diploid from nondiploid clones, except for neardiploid subpopulations, and permits the analysis of very small lesions.
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| 58. |
- Ruijter, Emiel Th, et al.
(författare)
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Rapid microwave-stimulated fixation of entire prostatectomy specimens
- 1997
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Ingår i: Journal of Pathology. - 0022-3417. ; 183:3, s. 369-375
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Tidskriftsartikel (refereegranskat)abstract
- Conventional fixation of large solid surgical specimens is a slow process. Consequently, autolytic damage to tissues may occur if the fixative does not reach the central part of the specimen in time. However, as there is also a time relationship between formalin fixation and antigen masking, fixation for too long can also be detrimental. In seeking the optimum balance for fixation, microwave irradiation might be of assistance. This study set out to evaluate methods for fixing entire prostate glands within a brief period of time, using microwave-stimulated formalin fixation. The results show that entire prostates can be optimally fixed if formalin is present throughout the tissue as the temperature is increased by microwave irradiation. This is achieved by injecting the fixative into the prostate at multiple sites immediately following prostatectomy. The technique described ensures standardization of a critical step during tissue processing, leading to uniform microscopic results with both routine and immunohistochemical stains. It is a simple, rapid method, suitable for routine diagnostic use. Using this modified approach, DNA of much larger sizes can be extracted from paraffin-embedded material, which could expand the possibilities for molecular analysis.
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