Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1658953 (tumor vasculature)
 2,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mode of antitumor action of rHu-TNF was elucidated in BALB/c mice bearing Meth A fibrosarcoma 7 days after transplantation with respect to time course, dose-response relationships and selectivity of the effects. The maximal cytotoxic effect on tumor cells revealed by inhibition of DNA synthesis and maximal lesional effect on tumor vasculature revealed by change in blood pool-size in the tissue were detected at 30 min and 1 h after administration of rHu-TNF, respectively. The dose-response relationship between cytotoxic and tumoricidal effects of rHu-TNF was irrespective of administration route. ED50s of these antitumor effects after i.v. administration of rHu-TNF were about 50 times as high as ED50s after i.t. administration. ED50 of i.t. given rHu-TNF for vascular effect was about 20 times as high as that for cytotoxicity while ED50 of i.v. rHu-TNF for vascular effect was only 2-3 times as high as that for cytotoxicity. The whole body autoradiographies with [125I]HSA given i.v. to see the blood influx into tumor tissue and [14C]thymidine given i.v. to see DNA synthesis in the whole body after administration of rHu-TNF revealed that the distribution of radioactivity was markedly changed in the tumor alone without any detectable change in other whole body tissues. In conclusion, the in vivo antitumor effect of rHu-TNF given i.t. or i.v. appears to be exerted through the direct action on Meth A sarcoma rather than indirectly on tumor vasculature. Under present conditions, the effect of rHu-TNF in the whole body tissues seems rather selective on cells and vasculature of the tumor.
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PMID:Mode of antitumor action of recombinant human tumor necrosis factor on the sarcoma Meth A transplanted in the mouse. 327 91

The specific uptake of 125I-A6H antibody by xenografts of the human renal cell carcinoma (RCC) TK177G in the athymic mouse was considerably greater than that seen for other human tumor xenografts and their associated antibodies (e.g., 125I-B6.2 uptake by the human breast carcinoma, Clouser). In addition the A6H-RCC model also demonstrated both greater localization indices and absolute amount of antibody bound than did the B6.2-Clouser model. Several physiological factors were studied to assess whether they might play a role in this greater specific uptake. Vascular volume was determined using the in situ labeling of red blood cells with 99mTc. Vascular permeability was determined by measuring the amount of 125I-labeled bovine serum albumin and 131I-labeled nonspecific IgG1 (anti-horseradish peroxidase) extravasated out of the tumor vasculature during 1 hr. Relative blood flow to the tumor was determined using the 86Rb method. Blood flow and vascular permeability were found to be significantly greater in the RCC tumor xenografts than in Clouser tumors. Differences in vascular permeability were especially dramatic, showing the vasculature of the RCC xenograft was twice as permeable as that of the Clouser tumor. Animals bearing either RCC or Clouser xenografts were injected with a monoclonal antibody to human major histocompatibility complexes (125I-labeled anti-human histocompatibility complex A, B, C). Tumor uptake of 125I-labeled anti-human histocompatibility complex A, B, C was found to be 5 times greater in RCC than Clouser xenografts. These results, therefore, suggest that the differences seen in the physiological factors studied can account for some of the greater specific 125I-A6H uptake by the RCC tumor than 125I-B6.2 uptake by the Clouser xenograft.
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PMID:Correlation of vascular permeability and blood flow with monoclonal antibody uptake by human Clouser and renal cell xenografts. 333 93

Using a polymer casting technique in conjunction with scanning electron microscopy, the three-dimensional characterization of tumor microvasculature as a function of age of renal adenocarcinoma in the rat kidney is undertaken. The microvasculature of the rat tumor model is compared with VX2 carcinoma in the rabbit leg muscle. Light microscopy and transmission electron microscopy on the rat tumor model are performed to correlate the features seen under scanning electron microscopy of vascular casts. The casts show marked differences between tumor and normal microvasculature. The tumor vascular architecture appears disarrayed with prevalent atypical features such as coils, ribbons, sheets, dense capillary networks, saccular dilatations, leaky and otherwise highly irregular vessels. Sprouts of new growth capillaries are seen throughout the tumor casts. Compressed vessels are present and become more pronounced in older tumors. These features are not observed in normal controls treated under identical conditions. The application of this high resolution three-dimensional casting technique to tumor studies is promising for research in basic tumor mechanics as well as in the effects of tumor vasculature on mediating radiation and chemotherapy and the fundamental mechanisms of metastasis.
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PMID:Characterization of solid tumor microvasculature: a three-dimensional analysis using the polymer casting technique. 333 61

Stereoscopic observation via an implanted sight glass in mice bearing transplanted methylcholanthrene-induced A-cells showed tumorivascular hemorrhage at 1-2 h after tumor necrosis factor (TNF) administration, congestion at 4-6 h, and hemorrhage, congestion, and blood circulation blockage at 24 h. Histological examination after TNF administration to mice bearing similar methylcholanthrene-induced A-cell transplants showed thrombus formation in the tumor vasculature at 4 h and thereafter. Suppression of this thrombus formation with heparin had no apparent influence on the necrotic response, tumor growth inhibition or complete cure rate following TNF administration to mice bearing the methylcholanthrene-induced A-cell tumors. The results suggest that direct toxicity of TNF on tumor vasculature is a factor in the overall antitumor mechanism of TNF.
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PMID:Toxic effect of tumor necrosis factor on tumor vasculature in mice. 334 88

Pharmacokinetics of chemoembolization with a fibrous collagen carrier was studied in rabbit kidney and porcine liver models. Cisplatin (1 mg/ml) chemoembolization of liver and kidney was compared with i.v. and intraarterial cisplatin infusion. Tissue platinum concentration [Pt] was measured at 2.5 h by atomic absorption spectrometry. Renal platinum retention and Angiostat (collagen for embolization) concentration were linearly related (r = 0.87, p less than 0.001). At 10 mg/ml collagen for embolization, chemoembolized kidney [Pt] was 220 +/- 50 (SE; n = 4) times contralateral kidney [Pt], and 62 and 23 times renal [Pt] by i.v. and intraarterial infusion, respectively. At 10 mg/ml collagen for embolization, chemoembolized liver [Pt] was 2 times hepatic [Pt] by i.v. and intraarterial infusion. Since hepatic tumor vasculature is end arterial, chemoembolization should yield high [Pt] in tumor (as in kidney) but lower levels in normal liver.
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PMID:Collagen chemoembolization: pharmacokinetics and tissue tolerance of cis-diamminedichloroplatinum(II) in porcine liver and rabbit kidney. 335 8

The effects of hyperthermia on murine tumor vasculature were studied by microangiography and histological examination. The tumors used were SCC VII carcinoma and mammary adenocarcinoma of syngeneic C3H/He mice. For the quantitative analysis of microangiographic changes, the percent (%) vascular area, which was defined as the percentage of opacified tumor vessel area to the entire tumor area, was determined in each microangiogram. The % vascular area after heating in a water bath at 44 degrees C for 30 min was minimized 24 hr after heating in both types of tumors. The histologic study revealed that the initial decrease of the % vascular area was due to congestion, thrombosis, and rupture of tumor vessels, and its subsequent increase was due to angiogenesis. SCC VII was more heat sensitive than mammary adenocarcinoma in terms of tumor growth delay, and tumor vessels of SCC VII were more vulnerable to heat than those of mammary adenocarcinoma. Histological examinations showed a marked difference in the architecture of vessels between the two types of tumors. Tumor vessels of mammary adenocarcinoma were supported by a connective tissue band, whereas those of SCC VII consisted of a single endothelial cell layer. Our findings suggest that the tumor vessels supported by a connective tissue band are less sensitive to heat than those without such support. The vascular damage of SCC VII was temperature dependent, and the critical temperature at which dramatic vascular damage appeared was between 42.7 degrees C and 43.7 degrees C.
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PMID:Microangiographic and histologic analysis of the effects of hyperthermia on murine tumor vasculature. 340 22

In search for an index of endothelial injury that would provide an early diagnosis of radiation pneumonitis, we investigated the plasma levels of von Willebrand Factor (Factor VIII Related Antigen, FVIII:RAg) in 14 patients undergoing pulmonary irradiation. This study was based on observations indicating that damage to the endothelium-rich pulmonary parenchyma may produce alterations in the synthesis, storage or release of FVIII:RAg, detectable in plasma. There was no correlation between FVIII:RAg levels and radiation pneumonitis, radiation dose, volume of irradiated lung, tumor burden, or time-interval between exposure and sampling. The heterogeneity of the neoplasms and the inconstant effects of radiation in the tumor vasculature are among several variables that may explain this lack of correlation. The plasma levels of FVIII:RAg cannot be used to diagnose or predict radiation pneumonitis.
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PMID:Von Willebrand factor levels do not predict or diagnose radiation pneumonitis. 348 36

The distribution of type VI collagen was examined immunohistochemically in normal tissues and in 24 human gliomas and six medulloblastomas. Its localization in the neoplasms was compared with that of fibronectin and glioma-mesenchymal extracellular matrix (GMEM) glycoprotein. In normal non-neural tissues type VI collagen was demonstrated in the interstitial connective tissue and in some basement membranes. In normal brain it was localized to the vasculature, leptomeninges, and pial-glial membrane. In neoplasms type VI collagen and fibronectin codistributed in the vasculature and stromal connective tissue. The GMEM glycoprotein, as identified by monoclonal antibody (MAb) 81C6, and a related glioma-mesenchymal matrix antigen identified by MAb 2A6, were expressed not only in the tumor vasculature and connective tissue, but also within the tumor parenchyma in association with glioma cells. The staining intensity was variable in 20 malignant gliomas and weak to absent in two pilocytic astrocytomas and six medulloblastomas. An oligodendroglioma and ependymoma both expressed the 2A6 epitope, but staining with MAb 81C6 was weak to absent. The antigens identified by MAb 81C6 and MAb 2A6 represent the only recognized extracellular matrix components, other than proteoglycans, that are associated with glioma cells in vivo. As prominent constituents of the pericellular matrix, they may be involved in recognized matrix functions such as the modulation of cell adhesion and migration.
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PMID:Distribution of type VI collagen in human gliomas: comparison with fibronectin and glioma-mesenchymal matrix glycoprotein. 365 35

The extracellular matrix is involved in many aspects of tumor cell biology, including tumor invasion and metastasis. 2A6 and 81C6 are murine monoclonal antibodies that identify glioma-mesenchymal extracellular matrix antigens. The 81C6 antigen is a high molecular weight glycoprotein composed of Mr 230,000 subunits. The expression of 2A6 antigen, 81C6 glycoprotein, fibronectin (FN), and laminin (LN) was examined immunohistochemically in ten malignant gliomas (MG) and four medulloblastomas (MBT). 2A6 and 81C6 were expressed in similar patterns by the neoplastic neuroepithelial cells in 9/10 MG and 1/4 MBT. The staining was typically diffuse and amorphous, without visualization of distinct cell bodies or processes. Less frequently, antigen was detected within tumor cell cytoplasm. In most tumors the staining was greatest in the perivascular regions. In two MG, 2A6 and 81C6 were expressed only by a subpopulation of neoplastic cells. Although intense staining was also associated with hyperplastic vascular and mesenchymal cells, many small and medium size blood vessels stained weakly or not at all. In contrast, FN and LN were expressed uniformly and intensely in the tumor vasculature, but were not expressed by neoplastic neuroepithelial cells. The 2A6 antigen and 81C6 glycoprotein are immunohistochemically distinct from FN and LN. These monoclonal antibody-defined antigens are heterogeneously expressed by neoplastic neuroepithelial cells and hyperplastic vascular-mesenchymal elements in MG and MBT. The 2A6 and 81C6 monoclonal antibodies will be useful reagents in the investigation of the extracellular matrix of malignant neuroepithelial neoplasms.
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PMID:Immunolocalization of monoclonal antibody-defined extracellular matrix antigens in human brain tumors. 403 75

This study was undertaken to determine the fluorescein angiographic characteristics of retinoblastomas, to determine the effect of various methods of treatment of these fluorescein patterns, and to determine whether fluorescein angiography can be of value in determining the response to treatment. We performed fluorescein angiography one or more times on 31 patients with retinoblastoma. Small tumors confined to the retina characteristically showed a well-defined pattern of retinal capillaries that filled during the arterial phase and became diffusely hyperfluorescent in the later phases. The fluorescein pattern varied with endophytic or exophytic tumors, depending upon the size of the tumor and the extent of vitreous or subretinal seeding. Following successful photocoagulation of a retinoblastoma, the tumor vascularity is markedly decreased and the tumor is replaced by fibrovascular tissue. Following successful radiotherapy, the tumor vasculature is altered but not typically obliterated. Three cases of presumed spontaneously regressed or arrested retinoblastomas showed much less vascularity than the active viable tumors. It is concluded that fluorescein angiography can be useful in the diagnosis and management of children with retinoblastoma.
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PMID:Fluorescein angiography of retinoblastoma. 610 Nov 27


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