0000000000130862
AUTHOR
F. Bertuzzi
showing 5 related works from this author
EVALUATION OF STABILITY AND ENZYMATIC ACTIVITIES OF PROTEOLYTIC ENZYMES USED IN PANCREATIC ISLET TRANSPLANTATION
2009
In pancreatic islets purification, for cell therapy applications, the major enzymes used are obtained from Clostridium hystoliticum; class I and class II collagenases (Coll-G and Coll-H). In a well defined composition Coll-G/Coll-H together enzymes working on hydrophobic amminoacid, the neutral protease (Dispase) or the thermolysin (Thermostable Neutral Protease), are used in Langerhans islets purification. By electrophoresis and gelatin zymography approaches, in combination to densitometry quantitative valuation we have compared in composition, stability and autodigestion processes C. hystoliticum collagenases, Neutral protease and Thermolysin from two different producers, Roche and Serva.…
A new method to valued efficiency of enzyme blend for pancreas tissue digestion.
2009
One of the best successful example of cell therapy is represented by islet transplantation since the '90. However islet isolation methods are not completely standardized yet. More than half of isolation procedures failed to isolate adequate islets for transplantation, due to variable pancreas condition, and to unpredictable enzymatic blend efficiency. Enzymes used for pancreas digestion are purified from Clostridium histolyticum; these enzymes has a broad substrate specificity and potent collagenolytic activity compared to vertebrate collagenases. However, a major obstacle in human islet isolation successful is due to the variability in composition and concentration of the collagenases used…
Comparative study on enzymatic activity and molecules stability of some commercial proteolytic enzymes used in pancreatic islet isolation.
2009
In pancreatic islets purification, for cell therapy applications, the major enzymes used are obtained from Clostridium hystoliticum; class I and class II collagenases (COLL G and COLL H). They are used in a defined tissue dissociation enzyme (TDE) mixtures together neutral protease (Dispase) or thermolysin (Thermostable Neutral Protease). The TDE mixtures were in part responsible for the success of the Edmonton protocol; however, just to now, people working in islets purification found discrepancy in an application to another one. This variability in application see in the enzymatic blend composition the higher accused, such as the contamination from endotoxines due to extractive production…
Image segmentation to evaluate islets of langherans
2008
This contribution deals with an unsupervised system to process digital photomicrographs in order to locate and analyze islets of Langherans in human pancreases. The experiment has been conducted on real data and, though we are still going to complete the evaluation of the whole method, we expect to define a set of proper features (e.g. area, perimeter, fractal dimension, shape complexity, texture and entropy) useful for a fast and reliable counting of healthy cells. In particular, this research aims to measure the advisability of a possible implantation in patients affected by type I diabetes mellitus
A new method to valued efficiency of enzyme blends for pancreas tissue digestion
2009
One of the best successful examples of cell therapy is represented by islet transplantation since 1990. However islet isolation methods are not completely standardized yet. More than half of isolation procedures failed to isolate adequate islets for transplantation, due to variable pancreas conditions and to unpredictable enzymatic blend efficiency. Enzymes used for pancreas digestion include collagenases and neutral proteases: their composition and activity are largely variable between different batches. We set up a new in vitro method to better in vitro characterize enzymatic blend before its use in human pancreas. In our experimental approach human immortalized cells (ECV-304) or human is…