13 research outputs found

    Immunolymphoscintigraphy for Metastatic Sentinel Nodes: Test of a Model

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    Aim. To develop a method and obtain proof-of-principle for immunolymphoscintigraphy for identification of metastatic sentinel nodes. Methods. We selected one of four tumour-specific antibodies against human breast cancer and investigated (1), in immune-deficient (nude) mice with xenograft human breast cancer expressing the antigen if specific binding of the intratumorally injected, radioactively labelled, monoclonal antibody could be scintigraphically visualized, and (2) transportation to and retention in regional lymph nodes of the radioactively labelled antibody after subcutaneous injection in healthy rabbits. Results and Conclusion. Our paper suggests the theoretical possibility of a model of dual isotope immuno-lymphoscintigraphy for noninvasive, preoperative, malignant sentinel node imaging

    Early Effects of Combretastatin-A4 Disodium Phosphate on Tumor Perfusion and Interstitial Fluid Pressure

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    Combretastatin-A4 disodium phosphate (CA4DP) is a vascular-disruptive agent that causes an abrupt decrease in tumor blood flow. The direct actions of CA4DP include increases in vascular permeability and destabilization of the endothelial cytoskeleton, which are thought to contribute to occlusion of the tumor vasculature. It has been proposed that increased permeability causes a transient increase in interstitial fluid pressure (IFP), which in turn could collapse intratumoral blood vessels. We examined the immediate effects of CA4DP on tumor IFP in C3H mammary carcinoma. Mice were treated with 100 mg/kg CA4DP by intraperitoneal injection. Tumor perfusion was recorded by laser Doppler flowmetry at separate time points, and IFP was recorded continuously by the wick-in-needle method. In this study, we found that CA4DP treatment resulted in a rapid reduction in tumor perfusion, followed by a decrease in IFP; no increases in IFP were observed. This suggests that CA4DP-induced reductions in tumor perfusion are not dependent on increases in IFP

    Quantitative Estimates of Vascularity in Solid Tumors by Non-Invasive Near-Infrared Spectroscopy

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    We examined the relationship between non-invasive estimates of the tumor hemoglobin concentration by near-infrared spectroscopy (NIRS) and histological scores of tumor vascularity by Chalkley counts in seven tumor lines in nude mice [malignant gliomas: U87, U118, U373; small cell lung cancers (SCLC): 54A, 54B, DMS79; prostate cancer: MatLyLu (MLL)]. We also evaluated the effect of continuous anti-angiogenic treatment with TNP-470 on tumor hemoglobin concentration and tumor vascularity in U87 and MLL tumors. Non-invasive NIRS recordings were performed with a custom-built flash near-infrared spectrometer using light guide-coupled reflectance measurements at 800±10 nm. Chalkley counts were obtained from CD31-immunostained cryosections. The NIRS recordings in arbitrary absorbance units increased with tumor size in the individual tumors until a plateau was reached at approximately 150 mm(3). This plateau was relatively tumor line-specific. NIRS recordings at the plateau phase were strongly correlated (P<.001, n=71) to the histological vessel score (Chalkley count) of the same individual tumors excised immediately after the NIRS was performed. Non-invasive NIRS recordings of the highly vascularized gliomas (U87, U118, and U373) plus the MatLyLu tumor line were significantly higher than the three less vascularized SCLC tumor lines (P<.001). Continuous treatment with the anti-angiogenic compound TNP-470, an endothelial cell inhibitor, significantly retarded tumor growth in both U87 and MLL tumors, but all tumors eventually grew. When comparing treated and untreated tumors of similar size, both NIRS recordings and Chalkley counts were significantly lower in TNP-470-treated tumors (P<.05). In conclusion, the NIRS technique provides a non-invasive measure of the degree of vascularization in untreated tumors and the NIRS technique can measure modifications in tumor vascularization by anti-angiogenic therapy

    Acute Effects of Vascular Modifying Agents in Solid Tumors Assessed by Noninvasive Laser Doppler Flowmetry and Near Infrared Spectroscopy

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    The potential of noninvasive laser Doppler flowmetry (LDF) and near infrared spectroscopy (NIRS) to detect acute effects of different vascular-modifying agents on perfusion and blood volume in tumors was evaluated. C3H mouse mammary carcinomas (∼200 mm(3)) in the rear foot of CDF1 mice were treated with flavone acetic acid (FAA, 150 mg/kg), 5,6-dimethylxanthenone-4-acetic acid (DMXAA, 20 mg/kg), combretastatin A-4 disodium phosphate (CA4DP, 250 mg/kg), hydralazine (HDZ, 5 mg/kg), or nicotinamide (NTA, 500 mg/kg). Tumor perfusion before and after treatment was evaluated by noninvasive LDF, using a 41°C heated custom-built LDF probe with four integrated laser/receiver units, and tumor blood volume was estimated by NIRS, using light guide coupled reflectance measurements at 800±10 nm. FAA, DMXAA, CA4DP, and HDZ significantly decreased tumor perfusion by 50%, 47%, 73%, and 78%, respectively. In addition, FAA, DMXAA, and HDZ significantly reduced the blood volume within the tumor, indicating that these compounds to some degree shunted blood from the tumor to adjacent tissue, HDZ being most potent. CA4DP caused no change in the tumor blood volume, indicating that the mechanism of action of CA4DP was vascular shut down with the blood pool trapped in the tumor. NTA caused no change in either tumor perfusion or tumor blood volume. We conclude that noninvasive LDF and NIRS can determine acute effects of vascular modifying agents on tumor perfusion and blood volume

    Coregulation of Glucose Uptake and Vascular Endothelial Growth Factor (VEGF) in Two Small-Cell Lung Cancer (SCLC) Sublines In Vivo and In Vitro

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    We examined the relationship between (18)F- labeled 2-fluro-2-deoxy-d-glucose (FDG) uptake, and expression of glucose transporters (GLUTs) in two human small-cell lung cancer (SCLC) lines CPH 54A and CPH 54B. Changes in the expression of GLUTs and vascular endothelial growth factor (VEGF) during 12-, 18-, and 24 hours of severe hypoxia in vivo (xenografts) and in vitro (cell cultures) were recorded for both tumor lines. The two SCLC lines are subpopulations of the same patient tumor. In spite of their common genomic origin they represent consistently different metabolic and microenvironmental phenotypes as well as treatment sensitivities. There were higher levels of Glut-1 protein in 54B and a correspondingly higher FDG uptake in this tumor line (P<.001). During hypoxia a significant upregulation of in VEGF mRNA, GLUT-1 mRNA, and Glut-1 and -3 protein occurred with a distinctly different time course in the two cell lines. A similar co-upregulation of GLUT and VEGF was seen in hypoxic tumors of both lines. There were no significant changes of HIF-1α mRNA during hypoxia in either of the cell lines. A more detailed understanding of such correlations between glucose metabolism, angiogenesis, and microenvironmental phenotype of tumors, by positron emission tomography (PET) and molecular techniques might further sophisticate our interpretation of glycolytic predominance in tumors as seen by (18)FFDG PET

    Improved Effect of an Antiangiogenic Tyrosine Kinase Inhibitor (SU5416) by Combinations with Fractionated Radiotherapy or Low Molecular Weight Heparin

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    The effect of combining SU5416 with fractionated radiotherapy or with low molecular weight (LMW) heparin (dalteparin) was studied in U87 human glioblastoma xenografts in nude mice. SU5416 is antiangiogenic by a specific inhibition of the vascular endothelial growth factor receptor 2 (VEGFR-2), and heparins are assumed to bind VEGF. Both SU5416 (100 mg/kg every second day in 5 days) and 3 Gy x 5 produced moderate, yet significant, growth inhibition. Tumors treated with concomitant irradiation and short-term SU5416 maintained a lower growth rate during regrowth than the other treatment groups (P=.007). Dalteparin (1000 IE/kg subcutaneously once a day) had no growth-inhibitory effect on its own, but when this LMW heparin was added to the SU5416 schedule, a significantly enhanced growth inhibition was obtained. VEGF protein content in tumors was not significantly altered by SU5416, but a significant decrease in VEGF levels was found in tumors treated with concomitant dalteparin and SU5416 compared with controls (P=.03). We conclude that: 1) an additive growth-inhibitory effect is obtained by combining SU5416 and fractionated radiotherapy; and 2) LMW heparin (dalteparin), in combination with SU5416, decreases the level of VEGF in tumors and increases the growth-inhibitory effect of SU5416
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