Influence of Magnetic Field on Brain Activity During Administration of Caffeine

The aim of the present work is to evaluate the effect of caffeine, the world’s most popular psychoactive drug, on the electric activity of the rat’s brain that exposed to extremely low-frequency magnetic field (ELF-MF), during 15 days. The obtained results showed that administration of caffeine in a group of rats by dose of 10 mg/kg (equivalent to human daily consumption) caused a reduction in the mean power amplitude of electroencephalogram (EEG) trace for almost all frequency bands especially α (8–12 Hz). It was observed that the influence of caffeine was more evident in motor cortex than in visual cortex. While the exposure of another group to ELF-MF of intensity 0.2 mT during the same period caused an enhancement in the mean power amplitude of most EEG frequency bands; this was more observed in the right hemisphere of the brain than that of the left hemisphere. The administration of caffeine while rats were exposed to ELF-MF, led, after 5 days of exposure, to a great increase in the mean power amplitude of α band at all places of recording electrodes. It may be concluded that caffeine administration was more effective in reducing the hazardous of ELF-MF in motor cortex than in visual cortex.     

A conserved role for the zinc finger polyadenosine RNA binding protein,ZC3H14, in control of poly(A) tail length

The ZC3H14 gene, which encodes a ubiquitously expressed, evolutionarily conserved, nuclear, zinc finger polyadenosine RNA-binding protein, was recently linked to autosomal recessive, nonsyndromic intellectual disability. Although studies have been carried out to examine the function of putative orthologs of ZC3H14 in Saccharomyces cerevisiae, where the protein is termed Nab2, and Drosophila, where the protein has been designated dNab2, little is known about the function of mammalian ZC3H14. Work from both budding yeast and flies implicates Nab2/dNab2 in poly(A) tail length control, while a role in poly(A) RNA export from the nucleus has been reported only for budding yeast. Here we provide the first functional characterization of ZC3H14. Analysis of ZC3H14 function in a neuronal cell line as well as in vivo complementation studies in a Drosophila model identify a role for ZC3H14 in proper control of poly(A) tail length in neuronal cells. Furthermore, we show here that human ZC3H14 can functionally substitute for dNab2 in fly neurons and can rescue defects in development and locomotion that are present in dNab2 null flies. These rescue experiments provide evidence that this zinc finger-containing class of nuclear polyadenosine RNA-binding proteins plays an evolutionarily conserved role in controlling the length of the poly(A) tail in neurons.     

Sequence analysis of sub-genotype D hepatitis B surface antigens isolated from Jeddah,Saudi Arabia

Little is known about the prevalence of HBV genotypes/sub-genotypes in Jeddah province, although the hepatitis B virus (HBV) was identified as the most predominant type of hepatitis in Saudi Arabia. To characterize HBV genotypes/sub-genotypes, serum samples from 15 patients with chronic HBV were collected and subjected to HBsAg gene amplification and sequence analysis. Phylogenetic analysis of the HBsAg gene sequences revealed that 11 (48%) isolates belonged to HBV/D while 4 (18%) were associated with HBV/C. Notably, a HBV/D sub-genotype phylogenetic tree identified that eight current isolates (72%) belonged to HBV/D1, whereas three isolates (28%) appeared to be more closely related to HBV/D5, although they formed a novel cluster supported by a branch with 99% bootstrap value. Isolates belonging to D1 were grouped in one branch and seemed to be more closely related to various strains isolated from different countries. For further determination of whether the three current isolates belonged to HBV/D5 or represented a novel sub-genotype, HBV/DA, whole HBV genome sequences would be required. In the present study, we verified that HBV/D1 is the most prevalent HBV sub-genotype in Jeddah, and identified novel variant mutations suggesting that an additional sub-genotype designated HBV/DA should be proposed. Overall, the results of the present HBsAg sequence analyses provide us with insights regarding the nucleotide differences between the present HBsAg/D isolates identified in the populace of Jeddah, Saudi Arabia and those previously isolated worldwide. Additional studies with large numbers of subjects in other areas might lead to the discovery of the specific HBV strain genotypes or even additional new sub-genotypes that are circulating in Saudi Arabia.     

Importin alpha: a multipurpose nuclear-transport receptor

The importin alpha/beta heterodimer targets hundreds of proteins to the nuclear-pore complex (NPC) and facilitates their translocation across the nuclear envelope. Importin alpha binds to classical nuclear localization signal (cNLS)-containing proteins and links them to importin beta, the karyopherin that ferries the ternary complex through the NPC. A second karyopherin, the exportin CAS, recycles importin alpha back to the cytoplasm. In this article, we discuss control mechanisms that importin alpha exerts over the assembly and disassembly of the ternary complex and we describe how new groups of importin alpha genes arose during the evolution of metazoan animals to function in development and differentiation. We also describe activities of importin alpha that seem to be distinct from its housekeeping functions in nuclear transport.     

The cortisol awakening response (CAR) in male children with autism spectrum disorder

Our ability to adapt to change is fundamental. The cortisol awakening response (CAR) is a sharp rise in cortisol 30 min after waking to help prepare an individual for ensuing stress. Children with autism spectrum disorder (ASD) often have difficulty adapting to change. Exploration of the CAR is warranted; yet, the few studies investigating it are inconclusive. The CAR was investigated in 94 pre-pubertal male children 8-to-12 years of age with ASD (46) and typical development (TD, 48). Salivary samples were collected over three diurnal cycles involving two morning samples: M1: Immediately upon Waking and M2: 30-min Post Waking (M2 − M1 = CAR). The magnitude of the CAR was measured by independent two sample t-tests, variability was measured using Levene's Test, the sequence of the CAR was analyzed by a linear mixed-effects model and proportion of children exhibiting a CAR by chi-square test of independence. There were no significant differences on the CAR between the groups based on magnitude (t(92) = − 0.14, p = 0.89, d = 0.04), variability (F(45,47) = 1.11, p = 0.72, η² = 0.11) or the sequence over three days (F(2,88) = 0.26, p = 0.77, η² = 0.01). No significant differences were shown in the proportion of children exhibiting a CAR across the groups based on child (χ²(1) = 0.02, p = 0.89) or adult criterion (χ²(1) = 1.82, p = 0.18). Despite group differences in the regulation and responsivity of cortisol, the CAR is indistinguishable between children with and without ASD. Inconsistencies across studies may be due to age, criterion used, and diagnostic distinctions.     

CURRICULUM GUIDE FOR RESEARCH ETHICS WORKSHOPS FOR COUNTRIES IN THE MIDDLE EAST

To help ensure the ethical conduct of research, many have recommended educational efforts in research ethics to investigators and members of research ethics committees (RECs). One type of education activity involves multi‐day workshops in research ethics. To be effective, such workshops should contain the appropriate content and teaching techniques geared towards the learning styles of the targeted audiences. To ensure consistency in content and quality, we describe the development of a curriculum guide, core competencies and associated learning objectives and activities to help educators organize research ethics workshops in their respective institutions. The curriculum guide is divided into modular units to enable planners to develop workshops of different lengths and choose content materials that match the needs, abilities, and prior experiences of the target audiences. The content material in the curriculum guide is relevant for audiences in the Middle East, because individuals from the Middle East who participated in a Certificate Program in research ethics selected and developed the training materials (e.g., articles, powerpoint slides, case studies, protocols). Also, many of the activities incorporate active‐learning methods, consisting of group work activities analyzing case studies and reviewing protocols. The development of such a workshop training curriculum guide represents a sustainable educational resource to enhance research ethics capacity in the Middle East.     

Characterization of the receptor for insulin-like growth factor on Leishmania promastigotes

Insulin-like growth factor (IGF)-I constitutively present in the skin is one of the first growth factors that Leishmania parasites encounter after transmission to the vertebrate host. We have previously shown that IGF-I is a potent growth-promoting factor for Leishmania parasites. IGF-I binds specifically to a single-site putative receptor at the parasite membrane, triggering a cascade of phosphorylation reactions. In the present article we characterize the receptor for IGF-I on Leishmania (Leishmania) mexicana promastigotes. The receptor is a monomeric glycoprotein with a molecular mass of 65 kDa and is antigenically related to the alpha chain of human type 1 IGF-I receptor. Upon IGF-I stimulation the receptor undergoes autophosphorylation on tyrosine residues with activation of its signaling pathway. Activation of the IGF-I receptor also leads to phosphorylation of an 185-kDa molecule that is homologous to the substrate of the insulin receptor present in human cells, the insulin receptor substrate 1 (IRS-1).     

Inhibition of calpain blocks the phagosomal escape of Listeria monocytogenes

Listeria monocytogenes is a gram-positive facultative intracellular bacterium responsible for the food borne infection listeriosis, affecting principally the immunocompromised, the old, neonates and pregnant women. Following invasion L. monocytogenes escapes the phagosome and replicates in the cytoplasm. Phagosome escape is central to L. monocytogenes virulence and is required for initiating innate host-defence responses such as the secretion of the cytokine interleukin-1. Phagosome escape of L. monocytogenes is reported to depend upon host proteins such as γ-interferon-inducible lysosomal thiol reductase and the cystic fibrosis transmembrane conductance regulator. The host cytosolic cysteine protease calpain is required in the life cycle of numerous pathogens, and previous research reports an activation of calpain by L. monocytogenes infection. Thus we sought to determine whether host calpain was required for the virulence of L. monocytogenes. Treatment of macrophages with calpain inhibitors blocked escape of L. monocytogenes from the phagosome and consequently its proliferation within the cytosol. This was independent of any direct effect on the production of bacterial virulence factors or of a bactericidal effect. Furthermore, the secretion of interleukin-1β, a host cytokine whose secretion induced by L. monocytogenes depends upon phagosome escape, was also blocked by calpain inhibition. These data indicate that L. monocytogenes co-opts host calpain to facilitate its escape from the phagosome, and more generally, that calpain may represent a cellular Achilles heel exploited by pathogens.