The blocking efficacy of 4,9-anhydro-TTX (4,9-ah-TTX) and TTX on several isoforms of voltage-dependent sodium channels, expressed in Xenopus laevis oocytes, was tested (Na(v1.2), Na(v1.3), Na(v1.4), Na(v1.5), Na(v1.6), Na(v1.7), and Na(v1.8)). Generally, TTX was 40-231 times more effective, when compared with 4,9-ah-TTX, on a given isoform. An exception was Na(v1.6), where 4,9-ah-TTX in nanomole per liter concentrations sufficed to result in substantial block, indicating that 4,9-ah-TTX acts specifically at this peculiar isoform. The IC(50) values for TTX/4,9-ah-TTX were as follows (in nmol/l): 7.8 +/- 1.3/1,260 +/- 121 (Na(v1.2)), 2.8 +/- 2.3/341 +/- 36 (Na(v1.3)), 4.5 +/- 1.0/988 +/- 62 (Na(v1.4)), 1,970 +/- 565/78,500 +/- 11,600 (Na(v1.5)), 3.8 +/- 1.5/7.8 +/- 2.3 (Na(v1.6)), 5.5 +/- 1.4/1,270 +/- 251 (Na(v1.7)), and 1,330 +/- 459/>30,000 (Na(v1.8)). Analysis of approximal half-maximal doses of both compounds revealed minor effects on voltage-dependent activation only, whereas steady-state inactivation was shifted to more negative potentials by both TTX and 4,9-ah-TTX in the case of the Na(v1.6) subunit, but not in the case of other TTX-sensitive ones. TTX shifted steady-state inactivation also to more negative potentials in case of the TTX-insensitive Na(v1.5) subunit, where it also exerted profound effects on the time course of recovery from inactivation. Isoform-specific interaction of toxins with ion channels is frequently observed in the case of proteinaceous toxins. Although the sensitivity of Na(v1.1) to 4,9-ah-TTX is not known, here we report evidence on a highly isoform-specific TTX analog that may well turn out to be an invaluable tool in research for the identification of Na(v1.6)-mediated function, but also for therapeutic intervention.

Objective: To determine whether patients with pyridoxine-responsive seizures but normal biomarkers for antiquitin deficiency and normal sequencing of the ALDH7A1 gene may have PNPO mutations. Methods:We sequenced the PNPO gene in 31 patients who fulfilled the above-mentioned criteria.

In recent years, melatonin, i.e. the major endocrine product of the pineal gland, was investigated as to its possible regulatory role in the communication between the neuroendocrine and the immune systems. First indications that melatonin may be an endocrine immunomodulator came from early reports about antitumor effects in animals and humans. Since then evidence has accumulated suggesting that melatonin – as a well-preserved molecule during evolution – is indeed involved in the feedback between neuroendocrine and immune functions. At present we begin to discover molecular mechanisms, by which melatonin affects cellular functions in general, and from the variety of possible direct and indirect interactions it appears that melatonin may play a complex physiological role in neuroimmunomodulation. In this article we want to give a critical review of the numerous reports on melatonin influencing immune functions, and to discuss the possible different mechanisms of action, which were suggested recently.

Our data provide evidence for a strong link between a high TT/DHT ratio and an adverse metabolic phenotype in PCOS patients. This correlation was only found in PCOS patients, suggesting the TT/DHT ratio to be a new biomarker for an adverse metabolic phenotype in PCOS patients.

Chronic kidney disease (CKD) is associated with a multifactorial dysregulation of bone and vascular calcification and closely linked to increased cardiovascular mortality and concomitant bone disease. We aimed to investigate specific microRNA (miRNA) signatures in CKD patients to find indicators for vascular calcification and/or bone mineralization changes during CKD and after kidney transplantation (KT). A miRNA array was used to investigate serum miRNA profiles in CKD patients, then selected miRNAs were quantified in a validation cohort comprising 73 patients in CKD stages 3 to 5, 67 CKD patients after KT, and 36 healthy controls. A spectrum of biochemical parameters including markers for kidney function, inflammation, glucose, and mineral metabolism was determined. The relative expression of miR-223-3p and miR-93-5p was down-regulated in patients with CKD stage 4 and 5 compared to healthy controls. This down-regulation disappeared after kidney transplantation even when lower glomerular filtration rates (eGFR) persisted. MiR-223-3p and miR-93-5p were associated with interleukin-6 (IL-6) and eGFR levels, and by trend with interleukin-8 (IL-8), C-peptide, hematocrit, and parathyroid hormone (PTH). This study contributes new knowledge of serum miRNA expression profiles in CKD, potentially reflecting pathophysiological changes of bone and calcification pathways associated with inflammation, vascular calcification, mineral and glucose metabolism. Identified miRNA signatures can contribute to future risk markers or future therapeutic targets in bone and kidney disease.

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GM1 gangliosidosis manifests with progressive psychomotor deterioration and dysostosis of infantile, juvenile, or adult onset, caused by alterations in the structural gene coding for lysosomal acid beta-galactosidase (GLB1). In addition, allelic variants of this gene can result in Morquio B disease (MBD), a phenotype with dysostosis multiplex and entire lack of neurologic involvement. More than 100 sequence alterations in the GLB1 gene have been identified so far, but only few could be proven to be predictive for one of the GM1 gangliosidosis subtypes or MBD. We performed genotype analyses in 16 GM1 gangliosidosis patients of all phenotypes and detected 28 different genetic lesions. Among these, p.I55FfsX16, p.W65X, p.F107L, p.H112P, p.C127Y, p.W161X, p.I181K, p.C230R, p.W273X, p.R299VfsX5, p.A301V, p.F357L, p.K359KfsX23, p.L389P, p.D448V, p.D448GfsX8, and the intronic mutation IVS6-8A>G have not been published so far. Due to their occurrence in homozygous patients, four mutations could be correlated to a distinct GM1 gangliosidosis phenotype. Furthermore, the missense mutations from heteroallelic patients and three artificial nonsense mutations were characterized by overexpression in COS-1 cells, and the subcellular localization of the mutant proteins in fibroblasts was assessed. The phenotype specificity of 10 alleles can be proposed on the basis of our results and previous data.

No abstract