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Biomedical subjects

G Van Dessel

Publications and source records attributed to G Van Dessel.

At least 19 recordsLinked to original sources

Two cases of mucopolysaccharidosis type III (Sanfilippo). An anatomopathological study.

Anatomopathological studies of one case of Sanfilippo disease types A and C, respectively, are presented. The storage phenomenon is very severe in the central as well as in the peripheral nervous system of both patients. Light microscopy does not show significant differences between the two cases. Electron microscopy of the nervous system reveals in both cases the presence of variable amounts of zebra bodies and of membrano-granulo-vacuolar inclusions. The presence of larger amounts of zebra bodies in the type A case and of larger quantities of membrano-granulo-vacuolar inclusions in the type C case constitute probably a nondistinctive feature between the two types. Light and electron microscopic studies of visceral organs do not disclose significant differences either. It is concluded that no major morphological differences between Sanfilippo disease types A and C can be observed.

Adolescent

Two cases of mucopolysaccharidosis type III (Sanfilippo). A biochemical study.

The mucopolysaccharide and lipid composition of human nervous tissue and viscera from one case of Sanfilippo disease type A and one case of Sanfilippo disease type C, were investigated. In the brain a moderate increase of acid glycosaminoglycans occurred. This phenomenon was much more pronounced in the viscera, especially in the liver. In all tissues this increase was mainly due to an accumulation of heparan sulphate. Changes in lipid composition were noted, but can be regarded as secondary effects. The biochemical results reported also suggest some general conclusions. (a) AGAG and lipid analyses do not permit differentiation between the subtypes of Sanfilippo disease. (b) The differences in lipid composition can probably be considered as consequences of variation in secondary effects. (c) The severe demyelination in brain correlates well with the biochemical lipid analysis. However, in other instances it remains difficult to bridge the gap still existing between some morphological and biochemical data.

Adolescent

RNA synthesis in isolated bovine thyroid nuclei and nucleoli. alpha-Amanitin effect, a hint to the existence of a specific regulatory system.

DNA dependent RNA polymerase activities in isolated bovine thyroid nuclei and nucleoli have been studied. They retain their RNA synthetic activity for an extended period of time. This RNA synthetic activity is sensitive to actinomycin D and requires the presence of all four ribonucleoside triphosphates. The optimal conditions have been determined. Polyacrylamide gel electrophoresis reveals that the RNA synthesized has a size distribution ranging from 34S to 4S. The production of 18S-8S RNA is very sensitive to low concentrations of alpha-amanitin. However, in isolated bovine thyroid nuclei (not in nucleoli) this drug displays an effect on all RNA classes produced. The alpha-amanitin induced drastic decrease of [3H]-UMP incorporation in RNA of all sizes synthesized by isolated bovine thyroid nuclei is discussed.

Amanitins