Effect of superparamagnetic nanoparticles coated with various electric charges on α-synuclein and ß-amyloid proteins fibrillation process.

BACKGROUND: Most of nanoparticles are nontoxic and have high absorption capability. Therefore, nanoparticles binding can effectively restrain fibrillation of ß-amyloid and α-synuclein proteins and eventually prevent the toxicity of pathogenesis peptide of Alzheimer. Super paramagnetic iron oxide nanoparticles (SPIONs) contain iron oxide core which can be connected to a special part through magnetic coating. MATERIALS AND METHODS: In this study, the effect of SPIONs with different charges was simultaneously examined on the fibrillation of both ß-amyloid and α-synuclein proteins by applying Thioflavin-T assay. RESULTS: According to the results of the investigation on amyloid-fibrillation mechanism in both ß-amyloids and α-synucleins, it was revealed that negatively-charged nanoparticles encoded to -COOH by dextran-coating were able to have a considerable absorption decrease from 17,000-12,000 after 320 minutes delay to lag phase and decrease in binding level of thioflavin-T particles to ß-sheets. CONCLUSION: The different concentrations of these nanoparticles and special coating of each particle had an effect on the kinetics of ß-amyloid and α-synuclein fibrillations.

Importance of viral pathogens in children with acute gastroenteritis in the south of Iran.

BACKGROUND AND OBJECTIVES: Different types of viruses are the leading cause of acute diarrhea among infants and young children worldwide. Epidemiological surveillance of viral agents is critical for the develop.ment of effective preventive measures, including vaccines. This study aimed to determine the prevalence of the four major enteropathogenic viruses-rotavirus, norovirus, adenovirus and astrovirus-in children over 7 years of age. DESIGN AND SETTING: A cross-sectional descriptive study conducted on stool specimens of children with acute gastroenteritis admitted to the Pediatrics Unit of 17 Shahrivar Hospital in Borazjan, Iran from October 2008 to September 2010. PATIENTS AND METHODS: Acute gastroenteritis was defined as >=3 loose watery stools per 24 hours. A total of 375 stool samples were collected from hospitalized children aged < 7 years old with acute gastroenteritis. All samples were investigated by using enzyme-linked immunosorbent assay for the presence of viral antigens. RESULTS: Rotavirus was detected in 91 (24.3%) of the patients whereas the prevalence of norovirus, adenovirus and astrovirus was 12.5%, 5.1% and 2.4%, respectively. On average, 75.9% of children with viral diarrhea were younger than 2 years old (P=.023). All the strains of viral gastroenteritis studied peaked in the autumn, except for adenovirus which peaked in spring (P=.015). The most common clinical symptoms included diarrhea (92.2%), vomiting (68.7%), abdominal cramp (60.8%) and moderate dehydration (57.2%). CONCLUSION: Since nearly half of gastroenteritis cases (44.3%) were due to viral agents, testing for the viral antigens may guide the clinical approach to those patients with acute diarrhea particularly in the case of children less than 2 years old, and during cold seasons.