Modified Eu‐doped Y2O3 nanoparticles as turn‐off luminescent probes for the sensitive detection of pyridoxine

Europium‐doped yttrium oxide nanoparticles (Y₂O₃:Eu NPs) modified by captopril were prepared in aqueous solution. In this study, we report the effect of pyridoxine hydrochloride on the photoluminescence intensity of Y₂O₃:Eu NPs in pH 7.2 buffer solution. By increasing the pyridoxine concentration, the luminescence intensity of Y₂O₃:Eu NPs is quenched. The results show that this method demonstrates high sensitivity for pyridoxine determination. A linear relationship is observed between 0.0 and 62.0 μM with a correlation coefficient of 0.995 and a detection limit of 0.023 μM. Copyright © 2014 John Wiley & Sons, Ltd.     

Human adipose derived stem cell exosomes enhance the neural differentiation of PC12 cells

Molecular Biology Reports - Human adipose stem cells (hADSCs) are proper cell sources for tissue regeneration. They mainly mediate their therapeutic effects through paracrine factors as exosomes....     

Antimicrobial susceptibility profiles associated with bacterial meningitis among children: a referral hospital-based study in Iran

Bacterial meningitis continues to be associated with high morbidity and mortality rate worldwide, especially in the pediatric age group. This study was performed to identify the microbial etiologies of meningitis among 31 children, who were admitted in the Emergency Ward of a referral pediatric hospital in Iran. Culture identification showed that Streptococcus pneumoniae (12 subjects), Haemophilus influenzae (11 subjects) were the most common bacteria, followed by Escherichia coli (7 cases) and Neisseria meningitidis (only one case). Antibiotic susceptibility tests revealed that vancomycin had the best effect on S. pneumoniae in comparison with other antibiotics, whereas H. influenzae and E. coli were more susceptible to ceftriaxone, ceftazidime, and ceftizoxime than other antibiotics. In conclusion, despite the advances in antibiotic therapy and vaccine development, bacterial meningitis still is a health problem. S. pneumoniae, H. influenzae, and N. meningitidis are the main sources of bacterial meningitis, but other organisms such as E. coli should also be suspected, when a case is admitted to a referral pediatric hospital.     

Protective effect of gallic acid isolated from Peltiphyllum peltatum against sodium fluoride-induced oxidative stress in rat’s kidney

In the present study, the nephroprotective effect of gallic acid isolated from Peltiphyllum peltatum was examined in sodium fluoride (NaF) treated rats. Nephrotoxicity was induced by 1-week intoxication of NaF at 600 ppm through drinking water. The levels of thiobarbituric acid reactive substances, reduced glutathione as well as activities of superoxide dismutase and catalase in renal tissues homogenates were determined. The serum biochemical markers of renal injuries including creatinine, serum urea, blood urea nitrogen, uric acid levels as well as the levels of phosphate and calcium were also assessed. Intoxication with NaF caused a significant increase in the levels of thiobarbituric acid reactive substances (46 % versus to control) and reduced the glutathione concentration (47 %) and the activities of superoxide dismutase (46 %) and catalase (41 %) in renal tissues homogenates. NaF intoxication also induced significant alterations in the kidney biochemical markers increasing the levels of urea, uric acid, blood urea nitrogen, creatinine, and phosphate and decreasing the levels of calcium. Daily administration of gallic acid (20 mg/kg) for 1 week before NaF intoxication brought the antioxidant–oxidant balance similar to the NaF-untreated group. Silymarin, used a standard antioxidant agent, also showed a nephroprotective activity. We concluded that NaF caused nephrotoxicity and oxidative stress in renal tissues and daily administration of gallic acid for 1 week prior to intoxication inhibited toxicity and oxidative stress.     

Recovery of soil respiration after drying

Soils are frequently exposed to drying and wetting events and previous studies have shown that rewetting results in a strong but short-lived flush of microbial activity. The aim of this study was to determine the effect of the water content during the dry period on the size and duration of the flush and on the rate of recovery. Two soils (a sand and a sandy loam) were maintained at different water contents (WC) 30, 28 and 25 g water kg^?1 soil (sand) and 130, 105 and 95 g water kg^?1 soil (sandy loam) for 14 days, then rewet to the water content at which respiration was optimal [WC 35 (sand), WC200 (sandy loam)] and maintained at this level until day 68. Ground pea straw (C/N 26) was added and incorporated on day 1. The controls were maintained at the optimal water content throughout the 68 days. Respiration rates during the dry phase (days 1?C14) decreased with decreasing water content. The flush of respiration after rewetting peaked on day 15 in the sandy loam and on day 16 in the sand; it was greatest in the soils that had been maintained at the lowest water content [WC25 (sand) and WC95 (sandy loam)]. Cumulative respiration during the remainder of the incubation period in which all soils were maintained at optimal water content increased more strongly in the soils that had been dry compared to the constantly moist control. On the final day of the dry period (day 14), cumulative respiration in the dry soils was 29?C65% (sand) and 67?C94% (sandy loam) of the constantly moist control whereas on day 68 it was 80?C84% (sand) and 86?C96% (sandy loam). The greater increase in cumulative respiration in the previously dry soils can be explained by the reduced decomposition rates during the dry period which resulted in higher substrate availability on day 14 compared to the constantly moist control. Microbial community structure assessed by phospholipid fatty acid analyses changed over time in all treatments but was less affected by water content than respiration; it differed only between the highest and the lowest water content. These differences were maintained throughout the incubation period in the sandy loam and transiently in the sand. It can be concluded that the soil water content during the dry phase affects the size of the flush in microbial activity upon rewetting and that microbial activity in previously dried soils may not be fully restored even after 54 days of moist incubation, suggesting that drying of soil can have a significant and long-lasting impact on microbial functioning.     

Coordinated activity of ventral tegmental neurons adapts to appetitive and aversive learning

Our understanding of how value-related information is encoded in the ventral tegmental area (VTA) is based mainly on the responses of individual putative dopamine neurons. In contrast to cortical areas, the nature of coordinated interactions between groups of VTA neurons during motivated behavior is largely unknown. These interactions can strongly affect information processing, highlighting the importance of investigating network level activity. We recorded the activity of multiple single units and local field potentials (LFP) in the VTA during a task in which rats learned to associate novel stimuli with different outcomes. We found that coordinated activity of VTA units with either putative dopamine or GABA waveforms was influenced differently by rewarding versus aversive outcomes. Specifically, after learning, stimuli paired with a rewarding outcome increased the correlation in activity levels between unit pairs whereas stimuli paired with an aversive outcome decreased the correlation. Paired single unit responses also became more redundant after learning. These response patterns flexibly tracked the reversal of contingencies, suggesting that learning is associated with changing correlations and enhanced functional connectivity between VTA neurons. Analysis of LFP recorded simultaneously with unit activity showed an increase in the power of theta oscillations when stimuli predicted reward but not an aversive outcome. With learning, a higher proportion of putative GABA units were phase locked to the theta oscillations than putative dopamine units. These patterns also adapted when task contingencies were changed. Taken together, these data demonstrate that VTA neurons organize flexibly as functional networks to support appetitive and aversive learning.     

Stable Isotope and Trace Element Studies on Gladiators and Contemporary Romans from Ephesus (Turkey, 2nd and 3rd Ct. AD) - Implications for Differences in Diet

The gladiator cemetery discovered in Ephesus (Turkey) in 1993 dates to the 2^nd and 3^rd century AD. The aim of this study is to reconstruct diverse diet, social stratification, and migration of the inhabitants of Roman Ephesus and the distinct group of gladiators. Stable carbon, nitrogen, and sulphur isotope analysis were applied, and inorganic bone elements (strontium, calcium) were determined. In total, 53 individuals, including 22 gladiators, were analysed. All individuals consumed C₃ plants like wheat and barley as staple food. A few individuals show indication of consumption of C₄ plants. The δ¹³C values of one female from the gladiator cemetery and one gladiator differ from all other individuals. Their δ³⁴S values indicate that they probably migrated from another geographical region or consumed different foods. The δ¹⁵N values are relatively low in comparison to other sites from Roman times. A probable cause for the depletion of ¹⁵N in Ephesus could be the frequent consumption of legumes. The Sr/Ca-ratios of the gladiators were significantly higher than the values of the contemporary Roman inhabitants. Since the Sr/Ca-ratio reflects the main Ca-supplier in the diet, the elevated values of the gladiators might suggest a frequent use of a plant ash beverage, as mentioned in ancient texts.     

Expression Patterns of ABC Transporter Genes in Fluconazole-Resistant <Emphasis Type="Italic">Candida glabrata</Emphasis>

Clinical management of fungal diseases is compromised by the emergence of antifungal drug resistance in fungi, which leads to elimination of available drug classes as treatment options. An understanding of antifungal resistance at molecular level is, therefore, essential for the development of strategies to combat the resistance. This study presents the assessment of molecular mechanisms associated with fluconazole resistance in clinical Candida glabrata isolates originated from Iran. Taking seven distinct fluconazole-resistant C. glabrata isolates, real-time PCRs were performed to evaluate the alternations in the regulation of the genes involved in drug efflux including CgCDR1, CgCDR2, CgSNQ2, and CgERG11. Gain-of-function (GOF) mutations in CgPDR1 alleles were determined by DNA sequencing. Cross-resistance to fluconazole, itraconazole, and voriconazole was observed in 2.5 % of the isolates. In the present study, six amino acid substitutions were identified in CgPdr1, among which W297R, T588A, and F575L were previously reported, whereas D243N, H576Y, and P915R are novel. CgCDR1 overexpression was observed in 57.1 % of resistant isolates. However, CgCDR2 was not co-expressed with CgCDR1. CgSNQ2 was upregulated in 71.4 % of the cases. CgERG11 overexpression does not seem to be associated with azole resistance, except for isolates that exhibited azole cross-resistance. The pattern of efflux pump gene upregulation was associated with GOF mutations observed in CgPDR1. These results showed that drug efflux mediated by adenosine-5-triphosphate (ATP)-binding cassette transporters, especially CgSNQ2 and CgCDR1, is the predominant mechanism of fluconazole resistance in Iranian isolates of C. glabrata. Since some novel GOF mutations were found here, this study also calls for research aimed at investigating other new GOF mutations to reveal the comprehensive understanding about efflux-mediated resistance to azole antifungal agents.     

In-silico and in-vitro investigation on the phenylalanine metabolites’ interactions with hexokinase of Rat’s brain mitochondria

Hexokinase (HK) is the first enzyme of glycolysis pathway. In brain, most dominant form of HK, HK-I, binds reversibly to the outer mitochondria membrane. Those metabolites that affect binding or releasing of the enzyme from the mitochondria have regulatory effect on glucose consumption of the cell. In this study destructive effect of phenylalanine and its metabolites in relation to glucose metabolism in brain have been studied. The results show that phenylpyruvic acid decreases the activity of enzyme in the presence and absence of glucose-6-phosphate (G6P) and increases the release of the enzyme from mitochondria, whereas phenylalanine and phenyllactic acid have no such effects. Obtained Interactions and elicited binding energies of docking and MD simulations also showed more affinity for phenylpyruvic acid compared with the other potent inhibitors for hexokinase after the natural product of G6P. It is possible that phenylpyruvic acid is the cause of the reduction of glucose consumption by decreasing hexokinase activity and the higher inhibitory function. Therefore, production of ATP declines in brain cells.