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OBJECTIVES: Valproic and arundic acids are astrocytes-modulating agents with potential effects in the treatment of Alzheimer's disease (AD). S100B is an astrocytic cytokine with a possible role in the pathogenesis of AD. In this study, we aimed to assess the glioprotective effects of valproic and arundic acids against amyloid-ß-peptide (Aß)-induced glial death and contribution of S100B to the glioprotective effects of these agents in an astrocytic culture. MATERIALS AND METHODS: We used Aß25-35 at a concentration of 200 µM in 1321N1 astrocyte cells. We treated the cells with valproic acid (0.5 and 1 mM) and/or arundic acid 50 µM for 24 hr. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) test was used to measure cell viability. The intracellular and extracellular S100B levels were measured using an ELISA kit. The data were analyzed using one-way analysis of variance followed by the Tukey's test. RESULTS: Aß (200 µM) decreased the cell viability compared to the control group (P<0.001). Valproic acid (0.5 and 1 mM) and arundic acid (50 µM) ameliorated the gliotoxic effects of Aß (P<0.05). The Aß-treated group had higher S100B levels (both intracellular and extracellular) compared to the negative control groups (P<0.001). Arundic and valproic acids (0.5 and 1 mM) decreased both the intracellular and extracellular S100B levels compared to the Aß-treated group (P<0.001). CONCLUSION: By considering homeostatic and neuroprotective functions of astrocyte, the astroprotective effects and the attenuation of S100B level may be responsible, at least in part, for the beneficial effects of valproic and arundic acids in AD.
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OBJECTIVE: Cinnamaldehyde may be responsible for some health benefits of cinnamon such as its neuroprotective effects. We aimed to investigate the cinnamaldehyde neuroprotective effects against amyloid beta (Aß) in neuronal SHSY5Y cells and evaluate the contribution of N-methyl-D-aspartate (NMDA), ryanodine, and adenosine receptors and glycogen synthase kinase (GSK)-3ß, to its neuroprotective effects. MATERIALS AND METHODS: After seeding the cells in 96-well plates, adenosine (20, 40, 80, and 120 µM), NMDA (20, 40, 80, and 120 µM), and dantrolene (as a ryanodine receptor antagonist; 2, 4, 6, 8, and 16 µM) were added to the medium containing Aß25-35 and/or cinnamaldehyde. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide method was used to assess neurotoxicity and western blot to measure the GSK-3ß protein level. RESULTS: Cinnamaldehyde (15, 20, 23, and 25 µM) significantly reversed Aß-induced toxicity in SHSY5Y neuronal cells. Adenosine (20, 40, 80 and 120 µM) inhibited the neuroprotective effects of cinnamaldehyde (15 µM). NMDA (20, 40, 80, and 120 µM) reduced cinnamaldehyde (15 and 23 µM) neuroprotective effects against Aß neurotoxicity. Dantrolene (2, 4, 8, and 16 µM) significantly reduced cinnamaldehyde (15 µM) neuroprotective effects. Cinnamaldehyde (15 and 23 µM) suppressed the Aß-induced increment of GSK-3ß protein level. CONCLUSION: NMDA and adenosine receptors suppression together with ryanodine receptors stimulation may be relevant to cinnamaldehyde neuroprotective effects against Aß neurotoxicity. Moreover, the inhibition of GSK-3ß may contribute to the cinnamaldehyde neuroprotection.
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BACKGROUND: Despite encouraging data in terms of neurological outcome, stem cell based therapy for ischemic stroke in experimental models and human patients is still hampered by multiple as yet un-optimized variables, i.e., time of intervention, that significantly influence the prognosis. The aim of the present study was to delineate the optimum time for neural stem cells (NSCs) transplantation after ischemic stroke. METHODS: The NSCs were isolated from 14 days embryo rat ganglion eminence and were cultured in NSA medium (neurobasal medium, 2% B27, 1% N2, bFGF 10 ng/mL, EGF 20 ng/mL and 1% pen/strep). The cells were characterized for tri-lineage differentiation by immunocytochemistry for tubulin-III, Olig2 and GFAP expression for neurons, oligodendrocytes and astrocyte respectively. The NSCs at passage 3 were injected intraventricularly in a rodent model of middle-cerebral artery occlusion (MCAO) on stipulated time points of 1 & 12 h, and 1, 3, 5 and 7 days after ischemic stroke. The animals were euthanized on day 28 after their respective treatment. RESULTS: dUTP nick end labeling (TUNEL) assay and Caspase assay showed significantly reduced number of apoptotic cells on day 3 treated animals as compared to the other treatment groups of animals. The neurological outcome showed that the group which received NSCs 3 days after brain ischemia had the best neurological performance. CONCLUSIONS: The optimum time for NSCs transplantation was day 3 after ischemic stroke in terms of attenuation of ischemic zone expansion and better preserved neurological performance.
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Purpose: Some reports have shown neuroprotective effects of caffeine in several neurodegenerative disorders. However, its mechanism of action is not completely clear. Therefore, the aim of this study was to explore the interference of ryanodine, N-methyl-D-aspartate (NMDA) and adenosine modulators with the neuroprotective effects of caffeine against ß-amyloid (Aß) neurotoxicity in the SHSY5Y cells. Methods: The SHSY5Y cells were treated with Aß23-35 (20µM) and/or caffeine (0.6 and 1mM), or both for 24 hours. Adenosine (20, 40, 60, 80, 100µM), NMDA (20, 50, 70, 90µM), dantrolene (2, 4, 6, 8, 10µM) were also added to the medium and incubated for 24 hours. The cell viability was measured via the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) method. The data were analyzed using one-way ANOVA followed by Bonferroni test. Results: Caffeine at all the used concentrations (0.6, 0.8, 0.9, 1, and 3mM) significantly protected neuronal cells against Aß neurotoxicity. Adenosine at the concentrations of 20, 40, 80 and 100µM diminished the neuroprotective effects of caffeine (0.6 and 1mM) against Aß neurotoxicity. NMDA at the concentrations of 20, 50, 70 and 90µM blocked caffeine (0.6 and 1mM) neuroprotective effects. Dantrolene at the concentration of 2, 4, 6, 8 and 10µM diminished the neuroprotective effects of caffeine (0.6mM) and at the concentrations of 2 and 10µM impede caffeine (1mM) neuroprotection against Aß neurotoxicity. Conclusion: Caffeine produced neuroprotective effect against Aß neurotoxicity. Blockade of adenosine and NMDA receptors, as well as the activation of ryanodine receptors, may contribute to the neuroprotective effects of caffeine.
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BACKGROUND: Extended-spectrum ß-lactamases (ESBLs) is one of the most important mechanisms of resistance to ß-lactams especially among Enterobacteriaceae family including Klebsiella spp. Different types of extended-spectrum ß-lactamases including CTX-M-type and PER enzymes are identified among gram negative bacteria. OBJECTIVES: The current study aimed to determine the prevalence of CTX-M-type and PER extended-spectrum ß-lactamases among Klebsiella spp. isolated from clinical specimens in the teaching hospital of Kashan, Iran. PATIENTS AND METHODS: One hundred Klebsiella spp. were isolated from clinical specimens of hospitalized patients at Shahid-Beheshti hospital from December 2012 to November 2013. Disk diffusion method was used to determine the susceptibility of these isolates to 14 different antimicrobial agents; disks were purchased from MAST company (United Kingdom). The phenotypic double disk synergy confirmatory test was used to screen the isolates to produce extended-spectrum ß-lactamase. DNAs of isolates were extracted using boiling method and PCR assay was used to characterize the bla CTX-M type and bla PER genes. The purified PCR products were sent to Macrogen research company (Korea) for sequencing. RESULTS: Of the total 100 Klebsiella isolates, %93 was susceptible to imipenem. Resistance to ampicillin, ceftazidime, ceftriaxone, aztreonam and cefotaxime was (92%), (67%), (65%), (64%) and (59%), respectively. The phenotypic confirmatory test (PCT) confirmed that 35% (n = 35) of the isolates were ESBL-producing Klebsiella strains. The prevalence of bla CTX-M type and bla RER genes among Klebsiella isolates were 28% (n = 28) and 9% (n = 9), respectively. CONCLUSIONS: The prevalence of ESBL-producing Klebsiella strains in Shahid-Beheshti hospital in Kashan has increased. The study concluded that there was a high prevalence of the bla CTX-M type gene among ESBL positive isolates.
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CONTEXT: The CTX-M family consists of more than 50 ß-lactamases, which are grouped on the basis of sequences into five subtypes including CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9 and CTX-M-25. OBJECTIVES: The current study aimed to detect subtypes of CTX-M extended-spectrum ß-lactamases (ESBLs) among ESBL positive Klebsiella isolates from patients in Kashan, Iran. MATERIALS AND METHODS: A total of 100 clinical isolates of Klebsiella were collected and the isolates, which showed resistance or reduced susceptibility to cefotaxime, ceftazidime and/or aztreonam by the disk diffusion method were selected. These isolates were identified as ESBL-producing isolates by double disk synergy tests using clavulanic acid, cefotaxime, ceftazidime and aztreonam. The blaCTX-M type determinants were identified by the Polymerase Chain Reaction (PCR) method followed by DNA sequencing. RESULTS: Of the 100 Klebsiella isolates, 41 (41%) demonstrated resistance or reduced susceptibility to ceftazidime and/or aztreonam and 35% (n = 35) were ESBL-producers. Twenty-eight (8o%) of the ESBL-producing isolates carried the blaCTX-M type genes. Based on PCR assays and sequencing of blaCTX-M genes, CTX-M-1, CTX-M-2 and CTX-M-9 were identified in 21 (60%), 15 (42%) and nine (34%) of these isolates, respectively (GenBank accession numbers KJ803828-KJ803829). CONCLUSIONS: Our study showed that the frequency of blaCTX-M genes among Klebsiella isolates in our region is at an alarming rate. Also, we found a high prevalence of blaCTX-M-1 ß-lactamase in Klebsiella isolates in Kashan.
