PubMed Health⌕ Search

Biomedical subjects

V Dan

Publications and source records attributed to V Dan.

At least 19 recordsLinked to original sources

Hydrogels in endovascular embolization. IV. Effect of radiopaque spherical particles on the living tissue.

In this study we report the results of toxicological, histological and haematological experiments on radiopaque spherical particles based on poly(2-hydroxyethyl methacrylate). These particles have been developed for endovascular occlusion of various organs. Radiopacity was attained by two independent methods: the chemical attachment of radiopaque substances to the hydrogel or the precipitation of radiopaque substances in the hydrogel network. The first method yields particles that appear to have uniformly-distributed contrast material, but in the particles prepared by the second procedure the contrast material is predominantly located on the surface. The visibility of such particles by X-rays makes possible controlled embolus introduction and inspection of the polymer for long periods after embolization. Radiopaque contrasting changes the morphology and reduces the porosity of the material but supports quick thrombus formation. Embolic material implanted in rabbits becomes surrounded by a thin fibrous capsule and undergoes partial organization. This and other results of medico-biological investigations have fully demonstrated the biocompatibility of radiopaque spherical emboli, which can now be used clinically.

Animals↗

Patterns of action of glucoamylase isozymes from Aspergillus species on glycogen.

Glucoamylase isozymes from black Aspergillus species have been freed of all traces of alpha-amylase by chromatography on Bio-Gel P-100, as evidenced by limited hydrolysis of oxidized amylose. Glucoamylase I retains its ability to hydrolyze rabbit-liver glycogen rapidly. By contrast, glucoamylase II hydrolyzes glycogen slowly, and addition of alpha-amylase to glucoamylase II does not enhance its activity toward glycogen. These results indicate that alpha-amylase is not involved in hydrolysis of glycogen by glucoamylase.

Amylases↗