The Value of Intraoperative Near-Infrared Fluorescence Imaging Based on Enhanced Permeability and Retention of Indocyanine Green: Feasibility and False-Positives in Ovarian Cancer

Objective

In ovarian cancer, two of the most important prognostic factors for survival are completeness of staging and completeness of cytoreductive surgery. Therefore, intra-operative visualization of tumor lesions is of great importance. Preclinical data already demonstrated tumor visualization in a mouse-model using near-infrared (NIR) fluorescence imaging and indocyanine green (ICG) as a result of enhanced permeability and retention (EPR). The aim of this study was to determine feasibility of intraoperative ovarian cancer metastases imaging using NIR fluorescence imaging and ICG in a clinical setting.

Methods

Ten patients suspected of ovarian cancer scheduled for staging or cytoreductive surgery were included. Patients received 20 mg ICG intravenously after opening the abdominal cavity. The mini-FLARE NIR fluorescence imaging system was used to detect NIR fluorescent lesions.

Results

6 out of 10 patients had malignant disease of the ovary or fallopian tube, of which 2 had metastatic disease outside the pelvis. Eight metastatic lesions were detected in these 2 patients, which were all NIR fluorescent. However, 13 non-malignant lesions were also NIR fluorescent, resulting in a false-positive rate of 62%. There was no significant difference in tumor-to-background ratio between malignant and benign lesions (2.0 vs 2.0; P=0.99).

Conclusions

This is the first clinical trial demonstrating intraoperative detection of ovarian cancer metastases using NIR fluorescence imaging and ICG. Despite detection of all malignant lesions, a high false-positive rate was observed. Therefore, NIR fluorescence imaging using ICG based on the EPR effect is not satisfactory for the detection of ovarian cancer metastases. The need for tumor-specific intraoperative agents remains.

Trial Registration

ISRCTN Registry ISRCTN16945066     

The uptake and intracellular distribution of [35S]trithiomolybdate in bovine liver in vivo

[35S] trithiomolybdate was administered intravenously to a group of four steer at two dose rates, 1 and 26 mg Mo per animal. Radioactivity appeared rapidly in the liver and was distributed in all the subcellular fractions examined. Examination by Sephadex G-100 gel-filtration of the cytosol fraction showed that distinct 35S-binding protein peaks were present. The protein-bound radioactivity was displaceable and was identified as [35S]thiomolybdates. No radioactivity eluted with metallothionein, but 35S was associated with the high molecular weight copper fraction, eluted in the void volume of the column, which increased transiently after the administration of the higher dose. It was suggested that the presence of protein-bound thiomolybdates in the liver gave rise to new ligands, which altered the equilibrium of copper between the different metal-binding proteins. This might be similar to the alteration in the copper-binding of albumin produced by the presence of thiomolybdates.     

Variations of susceptibility to alloxan induced diabetes in the rabbit

The variations of susceptibility to alloxan induced Diabetes in a total of seventeen rabbits was described. Our study was designed to explore dosage schedules which might improve rabbit responsiveness to and survival after alloxan treatment. A wide range of response to intravenously administered alloxan was observed. Permanent diabetes (blood glucose 350 mg/dl) was found in three rabbits after a single injection (60 mg/kg in one, 100 mg/kg in two). This effect has persisted for eight months. By contrast, two other rabbits injected with a single dose of alloxan (60 mg/kg) developed only transient hyperglycemia. Similarly, four other rabbits either did not respond or had an incomplete response after receiving a total dose of 120 mg/kg. These data suggest that there is extreme variability in individual rabbits susceptibility to the diabetogenic affects of alloxan.     

Effects of some alcohols on the conformation of mitochondrial H+-ATPase complex and F1-ATPase from pig heart

The conformations of the H+-ATPase complex and F1-ATPase in low concentrations of methanol, ethanol, n-propanol, iso-propanol and t-butanol were studied by circular dichroism. For F1-ATPase, all but methanol first increased and then decreased the circular dichroism magnitude of helical bands as the alcohol concentration was increased. With ethanol, n-propanol, iso-propanol and t-butanol, the alpha-helix content reached a maximum at about 5% alcohol and began to decrease at 10%. The content of beta-sheet showed the opposite effect, reaching a minimum at 5% and increasing slightly at higher concentrations. None of the alcohols studied had a significant effect on the conformation of the H+-ATPase complex. This difference implies that the alcohols had a greater effect on free F1-ATPase than on the membrane-bound F1-ATPase. The hydrophobic protein F0 and the membrane lipids in the H+-ATPase complex may stabilize and protect F1 from the effects of the alcohols.     

Temperature Dependence of Drug Interaction with the Platelet 5-Hydroxytryptamine Transporter: A Clue to the Imipramine Selectivity Paradox

Although [3H]imipramine is a selective radioligand for the 5-hydroxytryptamine (5-HT) transporter in human platelets, its affinity for binding to the 5-HT transporter complex at 0 degrees C (0.6 nM) is significantly higher than its potency for inhibition of [3H]5-HT uptake at the physiological temperature of 37 degrees C (Ki = 29 nM). As this apparent discrepancy could be related to the assay temperature, we studied the thermodynamics of drug interaction with the 5-HT transporter at assay temperatures between 0 degrees C and 37 degrees C, using as radioligands [3H]imipramine (0 degrees C and 20 degrees C) and [3H]paroxetine (20 degrees C and 37 degrees C), a newly available probe for the 5-HT transporter. At 20 degrees C, Ki values of 14 tricyclic and nontricyclic drugs for inhibition of [3H]imipramine and [3H]paroxetine binding to human platelet membranes were highly significantly correlated (r = 0.98, p less than 0.001), validating the use of these two radioligands to study the 5-HT transporter over a temperature range larger than was previously possible with [3H]imipramine alone. The affinity of imipramine for the 5-HT transporter is progressively enhanced with decreasing incubation temperature, thus favoring the selectivity of [3H]imipramine for the 5-HT transporter at 0 degrees C. At 37 degrees C, the Ki of imipramine for inhibition of [3H]paroxetine binding is 32 nM, and equals its Ki value for inhibition of 5-HT uptake into human platelets. With the exception of chlorimipramine, other tricyclic 5-HT uptake inhibitors showed a temperature sensitivity in their interaction with the 5-HT transporter similar to that of imipramine.(ABSTRACT TRUNCATED AT 250 WORDS)     

Colorectal carcinoma antigens detected by hybridoma antibodies.

Hybridoma cells which secrete colorectal carcinoma-specific antibodies have been produced and used to study the antigenic structure of these tumor cells. Nineteen antibodies have been studied in detail, and 15 of these are colorectal carcinoma specific. Only two antibodies reactive with carcinoembryonic antigen (CEA) have been discovered and five other antibodies that react with distinct epitopes on the cell surface have been defined. Several antigens with distinct molecular characteristics have been shown to exist by use of hybridoma antibodies. Six hybridoma antibodies have been shown to mediate antibody-dependent cell-mediated cytotoxicity (ADCC).     

Density, distribution and mobility of surface anions on a normal/transformed cell pair

The distribution and mobility of cell surface anions was investigated on low passage cultures of secondary BALB/c embryonic fibroblasts and their SV40-transformed counterparts (VLM cells) using polycationized ferritin (PCF) as a label. While the absolute number of anions/nm² of membrane was equivalent on the two cell types, the topographical distribution and mobility of these anions was strikingly different. After pulse-labeling with PCF at 37 °C, anions on BALB/c fibroblasts occurred in large piled-up clusters separated by extensive areas of membrane ( = 0.47 μm) free of negative charges. Labeling at 4 °C reduced the degree of “piling up” within the clusters, but the intercluster spacing was maintained indicating that the anions have short-range mobility in the membrane and can be cross-linked into a tight lattice at 37 °C. These anions do not, however, demonstrate any long-range mobility during a 20 min post-label incubation in PBS. In contrast, anions on VLM cells are inherently present in a random configuration of microclusters and single anions with relatively small ( = 0.09 μm) intervening areas of low charge density. Short-range mobility of surface anions is not displayed, presumably as a result of the inter-site distance, but long-range mobility is indicated by the formation of large site clusters following a 20 min incubation in PBS after pulse-labeling. Very mild proteolysis of BALB/c fibroblasts induces a change in the topography of surface anions toward the random configuration typical of VLM cells. These data are discussed in relation to altered social interactions between tumor cells which may be influenced by cell-cell adhesion characteristics.