Basic findings and current developments in sphingolipidoses

A comparative study of cytoplasmic granules imaged by the real-time microscope, Nile Red and Filipin in fibroblasts from patients with lipid storage diseases

Cytoplasmic granules in fibroblasts, visualized without stains, or labelled with Nile red, Filipin, or anti-LAMP-1 (lysosome-associated membrane protein 1), were imaged using the real-time microscope (RTM). New advances in light microscope technology were applied to detect cytoplasmic granules (RTM-visible granules) and characterize them by imaging contrast, size, shape, cellular distribution, composition, motion dynamics and quantity. Appearing as solid spheroids or ring structures, the majority of the RTM-visible granules contained Nile-red labelled neutral lipids. A smaller subpopulation, appearing dimmer, with less imaging contrast, contained Filipin-labelled free cholesterol. Most lipid storage granules have a diameter ranging from 0.3 mum to 0.6 mum, with a small population measuring up to 1 mum. They typically clustered in the perinuclear region and displayed relatively small oscillatory motion. Immunofluorescence based on LAMP-1 labelling highlighted granular structures that were distinct and separate from RTM-visible granules and other structures in the light modality of the microscope. RTM-visible granules were associated with disease phenotypes that have increased cellular neutral lipid stores corresponding to the Nile red-labelled droplets (e.g. triacylglycerides, cholesterol esters). As predicted, the fibroblast strains with a defect resulting in Wolman disease, when compared to control samples, consistently had RTM-visible granules, higher in imaging contrast and with larger diameters, that were labelled with Nile red, and also an increased frequency of Filipin-cholesterol complexes. By comparison, in fibroblasts where the lipid storage is less evident (Gaucher and Farber diseases) or from GM(1) gangliosidosis, where the primary storage substances are oligosaccharides, fewer and smaller RTM-visible granules were observed. In some cases, changes in contrast and morphology in the unstained cytoplasmic compartments were more evident than in the labelled structures. In summary, applying the RTM imaging system to fibroblasts enables differences between the various disease types to be seen and, in specific examples, a unique phenotype can be readily discerned.

Study of brain and vascular plexus gangliosides in meningoencephalitis of various etiology

The content of brain and vascular plexus gangliosides and their composition have been studied in 15 cases of meningoencephalitis of various etiology and degree of disease. The most pronounced decrease of ganglioside concentration was found in brain of children, who died from herpes virus infection. Decrease of ganglioside content was revealed in brain grey matter of patients with influenza virus or meningococcus infection, but not in cases of mycoplasma infection. These data provide evidence of nerve cell destruction due to meningoencephalitis of various etiology. The biochemical data obtained are in good agreement with the results of the brain of children infection by herpes virus (increase of GD1b content in grey matter). Ganglioside content in vascular plexes of patients with meningoencephalitis was found to be, on the contrary, much higher (ca 4 times) than in the controls. The higher the lesion of choroid plexes in meningoencephalitis is, the higher the ganglioside content in them is.

Heritable metabolic storage diseases

During the last decade, examinations of skin biopsies have gained increasing importance in the search for a better understanding and facilitated diagnosis of metabolic storage diseases. In addition to biochemical and tissue culture techniques, light- and electron-microscopic investigations have been recommended in a number of such disorders (1-6). There are, however, a large number of different and inhomogeneous conditions to be identified in this group. At present, approximately 300 diseases can be identified as inborn errors of metabolism by the determination of a biochemically well-established underlying defect. Moreover, a yet undetermined number of pathological conditions is accompanied by the deposition of more or less defined storage materials in cutaneous tissue elements. It appears, therefore, premature to propose a systematic dermatopathology of metabolic storage diseases, and the following contribution should be understood as an attempt to indicate possibilities and chances by quoting some representative examples.

Genetic disorders presenting as "schizophrenia". Karl Bonhoeffer's early view of the psychoses in the light of medical genetics

There is overwhelming empirical evidence for the influence of genetic factors in the etiology of schizophrenic psychoses. An appreciable and still increasing number of exogenous factors have been known for decades that are capable of inducing psychoses that present as "schizophrenia" or are more or less similar to it. In this article, genetic disorders--chromosomal abnormalities and Mendelian diseases--are summarized that may be associated with such psychoses. These disorders frequently but not necessarily exhibit additional physical symptoms. Although the majority of schizophrenic psychoses can so far not be explained by exogenous factors or well-defined genetic disorders, the proportion of these etiologies among all cases may be higher than presumed so far, because they evade detection. Data from the literature are discussed in the light of Karl Bonhoeffer's early concept of exogenous reaction types and modern medical genetics.