Microscopic isolation and characterization of free living amoebae (FLA) from surface water sources.in Birjand, the capital city of the South Khorasan

Background and Aim: Free living amoebae (FLA) are amphizoic protozoa that are widely found in various environmental sources. They are known to cause serious infections in human and animal nervous systems. . The aim of the current study was to determine the presence of Acanthamoeba spp in surface water sources in Birjand city employing microscopic culture analysis based on morphology features of the amoebae. Materials and Methods: In this cross-sectional study, 50 samples of surface water sources in Birjand city. including . parks pools, public squares, waterfronts, and water stations were collected and .transferred to the laboratory and were passed through nitrocellulose filter paper. The remained elements in the filters were cultured on non-nutrient agar (NNA) with 100μl Escherichia coli suspension. After a few weeks of using morphological features,the amoeba grown were identified. Results: Out of the total of 50 samples cultured on non-nutrient agar (NNA), 19 (38%) samples.were morphologically polluted with Acanthamoeba spp,. In 2 samples (4%) a colony of Vahlkampfiidae were observed. Conclusion: The results indicated that a significant percentage of surface water sources in Birjand city was contaminated with Acanthamoeba spp. It is necessary for physicians, therefore, to take into account the diseases caused by these infectious agents. Besides, local regional health professionals should take into consideration the potential role of surface stagnant water sources in transferring these infectious agents. Placing warning signs in areas contaminated with these infectious agents seems a useful measure

Effect of Magnetic Tacrine-Loaded Chitosan Nanoparticles on Spatial Learning, Memory, Amyloid Precursor Protein and Seladin-1 Expression in the Hippocampus Of Streptozotocin-Exposed Rats

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory and cognitive dysfunction due to neuronal cell loss in higher brain centers. Senile plaques containing amyloid β (Aβ) are associated with this disease as well as a reduction in cholinergic neuron numbers. Tacrine is a reversible cholinesterase inhibitor in clinical use to treat moderate forms of AD. Chitosan nanoparticles represent an effective systemic delivery system for drugs. The application of tacrine-loaded chitosan nanoparticles has been shown to selectively increase tacrine concentrations in the brain tissue. In this study, we compared magnetic and non-magnetic tacrine-loaded chitosan nanoparticles for their bioactivity and neuroprotective potency in streptozotocin (stz)-induced neurodegeneration, an accepted animal model for AD. Male rats received a single injection of stz via an implanted cannula into the lateral brain ventricle. Tacrine (tac)-loaded chitosan nanoparticles were delivered into the tail vein. Spatial learning and memory were analyzed using the Morris water maze task. Amyloid precursor protein gene (APP) and seladin-1 gene expression were studied in the hippocampus by real time-PCR. Tac-loaded non-magnetic and tac-loaded magnetic chitosan nanoparticles improved spatial learning and memory after stz treatment with magnetic nanoparticles being most effective. Similarly, tac-loaded chitosan nanoparticles increased seladin-1 and reduced APP gene expression. Again, magnetic nanoparticles were more effective. These data reveal that tac-loaded non magnetic and tac-loaded magnetic chitosan nanoparticles to a higher extent improve brain deficits related to stz application. We conclude that the magnetic target drug delivery system is a promising therapeutic strategy to protect AD-related degenerating in the CNS.