F. Van Hoof

Pompe's Disease: An Inborn Lysosomal Disorder with Storage of Glycogen

SummaryAnatomopathological studies are reported in a new case of Pompes disease (glycogenosis type II). The topography of the selective neuronal involvement is again stressed and more accurately localized regarding the thalamus. The accumulation of glycogen-filled vacuoles in astroglia, Schwann cells and myenteric plexus is demonstrated by light or electron microscopy or both.The histochemical features of the basophilic material coexisting with glycogen in striated muscle are described. Our results indicate a close relationship between glycogen and the basophilic material; they indicate that phosphate groups may be responsible for the alcianophilia and metachromasia at low pH.Ultrastructural studies of biopsy and autopsy specimens of striated muscle show that much of the glycogen is in vacuoles which are most probably of lysosomal nature.

Infantile form of sialic acid storage disorder: Clinical, ultrastructural, and biochemical studies in two siblings

We describe two sibs with coarse facies, hepatosplenomegaly, prominent psychomotor retardation and unexpectedly fair complexion. Ultrastructural studies of conjunctival, skin, bone marrow and liver biopsies from these individuals showed generalized lysosomal storage of polysaccharidelike material, i.e., membrane bound inclusions containing sparse, fibrillo-granular material. Biochemical analyses of urine and cultured fibroblasts from these patients revealed increased levels of free (unbound) sialic acid.The ultrastructural and biochemical findings in these sibs are similar to those previously found in Salla disease, however, the clinical course is much more severe. It is concluded that these children represent a new pathogenetic entity whose basic defect is still to be defined.

Bile acids in peroxisomal disorders

Abstract. We examined serum bile acids in patients with different peroxisomal disorders. Patients with Zellweger syndrome (n= 23), infantile form of Refsum disease (n= 6) and neonatal adrenoleukodystrophy (n= 4) consistently had increased levels of bile acid precursors. Patients with X‐linked adrenoleukodystrophy, (n= 5) classical Refsum disease (n= 3), hyperpipecolic acidaemia (n= 4) and rhizomelic chondrodysplasia punctata (n= 9) did not have increased bile acid precursor levels. Total serum bile acids (41 μg ml‐1) and the percentage of bile acid precursors (80%) were highest in typical Zellweger patients who died young. Long‐living Zellweger patients, neonatal adrenoleukodystrophy patients and infantile Refsum disease patients had, on average, less cholestasis and a lower percentage of bile acid precursors. We also observed that total serum bile acids and the percentage of bile acid precursors decreased with age in longliving Zellweger patients. Screening for bile acid precursors, combined with very long chain fatty acids analysis is, in our experience, an easy and reliable firstline approach to the detection of peroxisomal disorders.

Human hair follicle grafts onto nude mice: morphological study

In recent years, genetically immunodeficient animals have been widely used for xenograft experiments, mainly in the field of cancer research. Heterologous skin, including human skin, has been grown away from the donor after grafting on congenitally athymic nude mice. Normal human skin and diseased skin processes have been studied in this model. In this paper we report preliminary data on morphological aspects of skin appendageal behavior and especially hair follicle growth in a number of skin specimens grafted onto nude mice.