Evaluation of CSF Neurotransmitters and Folate in 25 Patients with Rett Disorder and Effects of Treatment

Background: Rett disorder (RD) is a progressive neurodevelopmental entity caused by mutations in the MECP2 gene. It has been postulated that there are alterations in the levels of certain neurotransmitters and folate in the pathogenesis of this disease. Here we re-evaluated this hypothesis. Patients and Methods: We evaluated CSF folate, biogenic amines and pterines in 25 RD patients. Treatment with oral folinic acid was started in those cases with low folate. Patients were clinically evaluated and videotaped up to 6 months after therapy. Results: CSF folate was below the reference values in 32% of the patients. Six months after treatment no clinical improvement was observed. Three of the four patients with the R294X mutation had increased levels of a dopamine metabolite associated to a particular phenotype. Three patients had low levels of a serotonin metabolite. Two of them were treated with fluoxetine and one showed clinical improvement. No association was observed between CSF folate and these metabolites, after adjusting for the patients age and neopterin levels. Conclusion: Our results support that folinic acid supplementation has no significant effects on the course of the disease. We report discrete and novel neurotransmitter abnormalities that may contribute to the pathogenesis of RD highlighting the need for further studies on CSF neurotransmitters in clinically and genetically well characterized patients.

Effects of a Shortage of Imiglucerase on Three Patients with Type I Gaucher Disease

Background: Children with Gaucher disease type I (GD1) are usually treated with enzyme replacement therapy (ERT) at a dose of 30-60U/Kg/2W. Recently, due to an acute shortage supply of imiglucerase, a reduced dose or a reduced infusion frequency was recommended. Objective: To evaluate the effects of a reduced infusion frequency of imiglucerase over 15 months of follow-up. Patients and Methods: Three patients (1M:2F) were treated with ERT since a median age of 7 years (range 5-12). Only one had bone crisis and Erlenmeyer deformations. Median duration of treatment before dose reduction was 3 years (range 1-8). ERT resulted in total regression of symptoms, normalization of hematological parameters and progressive improvement of chitotriosidase in all patients. In August 2009 infusion schedule was changed from a media 45U/Kg every two weeks to every four weeks. Results: All patients remained asymptomatic and with no major change on hematological parameters except for the patient with bone crisis who presented subnormal platelet count. All patients showed an upward trend in chitotriosidase values. Comments: Although a longer follow-up is needed, is probable that even children completely stabilized can probably not be kept on lower doses even though the reduction of frequency of the infusions represent a lower social burden.

Differential Internalization of Amphotericin B - Conjugated Nanoparticles in Human Cells and the Expression of Heat Shock Protein 70

Although a variety of nanoparticles (NPs) functionalized with amphotericin B, an antifungal agent widely used in the clinic, have been studied in the last years their cytotoxicity profile remains elusive. Here we show that human endothelial cells take up high amounts of silica nanoparticles (SNPs) conjugated with amphotericin B (AmB) (SNP-AmB) (65.4 12.4 pg of Si per cell) through macropinocytosis while human fibroblasts internalize relatively low amounts (2.3 0.4 pg of Si per cell) because of their low capacity for macropinocytosis. We further show that concentrations of SNP-AmB and SNP up to 400 mg/mL do not substantially affect fibroblasts. In contrast, endothelial cells are sensitive to low concentrations of NPs (above 10 mg/mL), in particular to SNP-AmB. This is because of their capacity to internalize high concentration of NPs and high sensitivity of their membrane to the effects of AmB. Low-moderate concentrations of SNP-AmB (up to 100 mg/mL) induce the production of reactive oxygen species (ROS), LDH release, high expression of pro-inflammatory cytokines and chemokines (IL-8, IL-6, G-CSF, CCL4, IL-1b and CSF2) and high expression of heat shock proteins (HSPs) at gene and protein levels. High concentrations of SNP-AmB (above 100 ug/mL) disturb membrane integrity and kill rapidly human cells(60% after 5 h). This effect is higher in SNP-AmB than in SNP.