Enhancing early bladder cancer detection with fluorescence-guided endoscopic optical coherence tomography.

We report an experimental study of the possibility of enhancing early bladder cancer diagnosis with fluorescence-image-guided endoscopic optical coherence tomography (OCT). After the intravesical instillation of a 10% solution of 5-aminolevulinic acid, simultaneous fluorescence imaging (excitation of 380-420 nm, emission of 620-700 nm) and OCT are performed on rat bladders to identify the photochemical and morphological changes associated with uroepithelial tumorigenesis. The preliminary results of our ex vivo study reveal that both fluorescence and OCT can identify early uroepithelial cancers, and OCT can detect precancerous lesions (e.g., hyperplasia) that fluorescence may miss. This suggests that a cystoscope combining 5-aminolevulinic acid fluorescence and OCT imaging has the potential to enhance the efficiency and sensitivity of early bladder cancer diagnosis.

Pharmacokinetics of 4-[4"-(2",2",6",6"-tetramethyl-1"-piperidinyloxy) amino]-4'-demethylepipodophyllotoxin in mice bearing sarcoma 180.

AIM: To study the pharmacokinetics of 4-[4"-(2",2",6",6"-tetramethyl- 1"-piperindyloxy) amino]-4'-demethylepipodophyllotoxin (GP-7) in mice bearing sarcoma 180. METHOD: Using HPLC with a uv detector at 285 nm. RESULTS: The plasma concentration-time course of GP-7 in mice was best fitted to a 2-compartment open modle after iv 20, 60 mg.kg-1. At both doses the plasma T1/2 beta was around 40 min. The highest concentration was found in liver and lung. The level of GP-7 was higher in tumor than in kidney, spleen, and bone marrow after ip 20 mg.kg-1 for 10 d. Urinary excretion of GP-7 as unchanged drug accounted for about 20% of the administered doses 72 h after injection. CONCLUSION: GP-7 disappeared more slowly from the plasma of mice bearing sarcoma 180, distributed extensively over the tissues and was partially excreted from urine. The concentrition of GP-7 in tumor was higher.

[Determination of hexamethylene bisacetamide in plasma by high performance liquid chromatography].

A high performance liquid chromatographic assay was developed for determination of the plasma concentration of hexamethylene bisacetamide (HMBA) in rabbit. Plasma samples were vortex-mixed with 0.3 ml of methanol and centrifuged at 10000 r/min for 5 min. A 20 microliters aliquot of the supernatant was injected into the HPLC system. Analysis was performed on a Du Pont Zorbax C18 column (250 mm x 4.6 mm, 10 microns) with a precolumn (50 mm x 4.6 mm, 10 microns, YWG-C18). The eluent was methanol--water (30:70), with flow rate of 1.0 ml.min-1 and UV detection at 210 nm. The limit of detection was 1.0 microgram.ml-1 in plasma and the calibration curve was linear over the range 5-1000 micrograms.ml-1 (r = 0.9988). The HPLC assay was applied for studying the pharmacokinetics of HMBA in rabbit.