Sunscreens are mainly characterized by their sun-protection factor (SPF), which is measured according to the in vivo gold standard ISO 24444. Although the SPF concept is simple, SPF values are difficult to measure, due to the rather high variability caused by the complex interaction of light and skin. For half a century, there have been attempts to correlate the costly and ethically controversial in vivo procedure with a non-invasive (in vitro) method.
View Article and Find Full Text PDFMucopolysaccharidosis type II (OMIM 309900) is a lysosomal storage disorder caused by iduronate 2-sulfatase (IDS) deficiency and accumulation of glycosaminoglycans, leading to progressive neurodegeneration. As intravenously infused enzyme replacement therapy cannot cross the blood-brain barrier (BBB), it fails to treat brain pathology, highlighting the unmet medical need to develop alternative therapies. Here, we test modified versions of hematopoietic stem and progenitor cell (HSPC)-mediated lentiviral gene therapy (LVGT) using IDS tagging in combination with the ubiquitous MND promoter to optimize efficacy in brain and to investigate its mechanism of action.
View Article and Find Full Text PDFOligosaccharidoses, sphingolipidoses and mucolipidoses are lysosomal storage disorders (LSDs) in which defective breakdown of glycan-side chains of glycosylated proteins and glycolipids leads to the accumulation of incompletely degraded oligosaccharides within lysosomes. In metabolic laboratories, these disorders are commonly diagnosed by thin-layer chromatography (TLC) but more recently also mass spectrometry-based approaches have been published. To expand the possibilities to screen for these diseases, we developed an ultra-high-performance liquid chromatography (UHPLC) with a high-resolution accurate mass (HRAM) mass spectrometry (MS) screening platform, together with an open-source iterative bioinformatics pipeline.
View Article and Find Full Text PDFSphingolipidoses are severe, mostly infantile lysosomal storage disorders (LSDs) caused by defective glycosphingolipid degradation. Two of these sphingolipidoses, Tay Sachs and Sandhoff diseases, are caused by β-Hexosaminidase (HEXB) enzyme deficiency, resulting in ganglioside (GM2) accumulation and neuronal loss. The precise sequence of cellular events preceding, and leading to, neuropathology remains unclear, but likely involves inflammation and lysosomal accumulation of GM2 in multiple cell types.
View Article and Find Full Text PDFBackground: Urinary excretion of the tetrasaccharide 6-α-D-glucopyranosyl-maltotriose (Glc₄) is increased in various clinical conditions associated with increased turnover or storage of glycogen, making Glc₄ a potential biomarker for glycogen storage diseases (GSD). We developed an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) assay to detect Glc₄ in urine without interference of the Glc₄ isomer maltotetraose (M₄).
Methods: Urine samples, diluted in 0.
Sialic acid storage disease (SASD) is an inborn error resulting from defects in the lysosomal membrane protein sialin. The SASD phenotypical spectrum ranges from a severe presentation, infantile sialic acid storage disease (ISSD) which may present as hydrops fetalis, to a relatively mild form, Salla disease. Screening for SASD is performed by determination of free sialic acid (FSA) in urine or amniotic fluid supernatant (AFS).
View Article and Find Full Text PDFBased on the current weight of evidence of all available data, the risk for humans from the use of nano-structured titanium dioxide (TiO(2)) or zinc oxide (ZnO) currently used in cosmetic preparations or sunscreens is considered negligible. There is a large body of information that when viewed in its entirety is considered as sufficient to demonstrate that these nano-structured ultraviolet (UV) filters, irrespective of various treatments (coatings) or crystalline structure, can be regarded as safe for use at concentrations up to 25% in cosmetic products to protect the skin from harmful effects of solar UV radiation. "Nano" TiO(2) and ZnO formulated in topically applied sunscreen products exist as aggregates of primary particles ranging from 30-150 nm in size.
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