The aim of this study was to evaluate in vitro and in vivo imaging of HER-2-over-expressing tumours using near-infrared optical imaging. A fluorochrome probe was designed by coupling Cy5.5 to anti-HER-2 antibodies. Cells over-expressing (SK-BR-3 cells) or normally expressing (PE/CA-PJ34 cells) the HER-2 protein were incubated with the probe. After removing unbound probe molecules, fluorescence intensities were determined (a.u.: arbitrary units). Cells were additionally investigated using FACS and laser scanning microscopy. The probe was also injected intravenously into tumours bearing SK-BR-3 ( n=3) or PE/CA-PJ34 ( n=3). Whole-body fluorescence images were generated and analysed. The incubation of SK-BR-3 cells with the probe led to higher fluorescence intensities [2,133 (+/-143) a.u.] compared to controls [975 (+/-95) a.u.]. The results from FACS and immunocytochemical analysis were in agreement with these findings. A distinct dependency between the fluorescence intensity and the cell number used in the incubations was detected. In vivo, the relative fluorescence intensities in SK-BR-3 tumours were higher than in PE/CA-PJ34 tumours at 16-24 h after probe application. HER-2-over-expressing tumours were depictable in their original size. Labelling of HER-2 with Cy5.5 is suitable for in vitro and in vivo detection of HER-2-over-expressing tumour cells.

Most aortic aneurysms have a degenerative genesis and show a slow expansion over years. Only a few patients with a rapid progression of mycotic or inflammatory aneurysm during some weeks or months have been reported. We report a patient with a rapidly growing symptomatic infrarenal aneurysm with a maximal diameter of 53 mm, which developed over a 5-month period from a normal aorta and did not feature typical signs of degenerative, inflammatory, or mycotic aneurysm. The aneurysm was successfully treated by endovascular repair. A complete shrinking of the aneurysm sac was demonstrated during a few weeks postoperatively. Because the patient received chemotherapy with docetaxel, cisplatin, and 5-fluorouracil for metastatic gastric carcinoma 1 year before the aneurysm occurred, we postulate that chemotherapy induced a rapid expansion of the aorta in this patient.