Automatic quantification of microvessel density in urinary bladder carcinoma

Seventy-three TUR-T biopsies from bladder carcinoma were evaluated regarding microvessel density, defined as microvessel number (nMVD) and cross-section endothelial cell area (aMVD). A semi-automatic and a newly developed, automatic image analysis technique were applied in immunostainings, performed according to an optimized staining protocol. In 12 cases a comparison of biopsy material and the corresponding cystectomy specimen were tested, showing a good correlation in 11 of 12 cases (92%). The techniques proved reproducible for both nMVD and aMVD quantifications related to total tumour area. However, the automatic method was dependent on high immunostaining quality. Simultaneous, semi-automatic quantification of microvessels, stroma and epithelial fraction resulted in a decreased reproducibility. Quantification in ten images, selected in a descending order of MVD by subjective visual judgement, showed a poor observer capacity to estimate and rank MVD. Based on our results we propose quantification of MVD related to one tissue compartment. When staining quality is of high standard, automatic quantification is applicable, which facilitates quantification of multiple areas and thus, should minimize selection variability. © 1999 Cancer Research Campaig

Can routine outpatient follow-up of patients with bladder cancer be improved? A multicenter prospective observational assessment of blue light flexible cystoscopy and fulguration

Reza Zare,1 Magnus Grabe,2 Gregers G Hermann,3 Per-Uno Malmström4 1Department of Urology, Vestre Viken HF Bærum Hospital, Oslo, Norway; 2Department of Urology, Skåne University Hospital, University of Lund, Malmö, Sweden; 3Department of Urology, Herlev and Gentofte Hospital, Copenhagen University, Denmark; 4Department of Urology, Institute of Surgical Sciences, Uppsala University, Uppsala, Sweden Background: The aim of this prospective cohort study was to determine the feasibility of incorporating blue light flexible cystoscopy (BLFC) and biopsy/fulguration into routine outpatient follow-up of non-muscle invasive bladder cancer patients. Methods: The study included patients with non-muscle-invasive bladder cancer (NMIBC) who were scheduled for routine follow-up. Hexaminolevulinate was instilled in the outpatient department, and the bladder was examined under white light and then with BLFC. Biopsies were taken from all suspicious lesions. Small tumors and suspicious lesions were fulgurated on site; patients with larger lesions were referred to the operating room for resection. Results: The study included 69 patients, with a mean age of 70 years (range 33–89 years) and a mean duration since NMIBC diagnosis of 8 years. Most patients had high-grade cancer at initial diagnosis (52/69) and were at high risk of recurrence (48/69). Two patients per hour could be assessed using outpatient BLFC. Preparation and instillation of hexaminolevulinate took less than 10 minutes per patient, and patients had an additional waiting time of 45–60 minutes following instillation, while the hexaminolevulinate solution was retained in the bladder before examination. Eleven patients had histologically confirmed tumors that were identified using both white light flexible cystoscopy and BLFC. An additional three patients had tumors that were identified by BLFC only: two with Ta tumors and one with carcinoma in situ. Of the 14 patients with confirmed tumors, 11 could be managed on site with fulguration, whereas three were referred to the operating room. No adverse events attributable to BLFC were reported. Conclusion: Routine outpatient management of patients with NMIBC using BLFC and on-site biopsy/fulguration is feasible, despite the additional time required for hexaminolevulinate instillation, and appears to allow early detection of recurrent lesions, which can be fulgurated without the need for hospitalization. Keywords: bladder cancer, blue light, diagnosis, flexible cystoscopy, hexaminolevulinate, outpatient

Deciphering the mode of action of the processive polysaccharide modifying enzyme dermatan sulfate epimerase 1 by hydrogen-deuterium exchange mass spectrometry

Distinct from template-directed biosynthesis of nucleic acids and proteins, the enzymatic synthesis of heterogeneous polysaccharides is a complex process that is difficult to study using common analytical tools. Therefore, the mode of action and processivity of those enzymes are largely unknown. Dermatan sulfate epimerase 1 ( DS-epi1) is the predominant enzyme during the formation of iduronic acid residues in the glycosaminoglycan dermatan sulfate. Using recombinant DS-epi1 as a model enzyme, we describe a tandem mass spectrometry-based method to study the mode of action of polysaccharide processing enzymes. The enzyme action on the substrate was monitored by hydrogen-deuterium exchange mass spectrometry and the sequence information was then fed into mathematical models with two different assumptions of the mode of action for the enzyme: processive reducing end to non-reducing end, and processive non-reducing end to reducing end. Model data was scored by correlation to experimental data and it was found that DS-epi1 attacks its substrate on a random position, followed by a processive mode of modification towards the non-reducing end and that the substrate affinity of the enzyme is negatively affected by each additional epimerization event. It could also be shown that the smallest active substrate was the reducing end uronic acid in a tetrasaccharide and that octasaccharides and longer oligosaccharides were optimal substrates. The method of using tandem mass spectrometry to generate sequence information of the complex enzymatic products in combination with in silico modeling can be potentially applied to study the mode of action of other enzymes involved in polysaccharide biosynthesis