Alteration in the Expression of Parkinson’s-Related Genes in Rat Hippocampus by Exercise and Morphine Treatments

Russian Journal of Genetics - Parkinson’s disease (PD) as a genetically heterogeneous disease is the second common neurological disorder which is associated with motor deficits and dementia...     

Centrifugal isolation of SARS-CoV-2: numerical simulation for purification of hospitals’ air

Biomechanics and Modeling in Mechanobiology - Coronavirus and its spread all over the world have been the most challenging crisis in 2020. Hospitals are categorized among the most vulnerable...     

Influence of pore residues on permeation properties in the Kv2.1 potassium channel. Evidence for a selective functional interaction of K+ with the outer vestibule

The Kv2.1 potassium channel contains a lysine in the outer vestibule (position 356) that markedly reduces open channel sensitivity to changes in external [K(+)]. To investigate the mechanism underlying this effect, we examined the influence of this outer vestibule lysine on three measures of K(+) and Na(+) permeation. Permeability ratio measurements, measurements of the lowest [K(+)] required for interaction with the selectivity filter, and measurements of macroscopic K(+) and Na(+) conductance, were all consistent with the same conclusion: that the outer vestibule lysine in Kv2.1 interferes with the ability of K(+) to enter or exit the extracellular side of the selectivity filter. In contrast to its influence on K(+) permeation properties, Lys 356 appeared to be without effect on Na(+) permeation. This suggests that Lys 356 limited K(+) flux by interfering with a selective K(+) binding site. Combined with permeation studies, results from additional mutagenesis near the external entrance to the selectivity filter indicated that this site was located external to, and independent from, the selectivity filter. Protonation of a naturally occurring histidine in the same outer vestibule location in the Kv1.5 potassium channel produced similar effects on K(+) permeation properties. Together, these results indicate that a selective, functional K(+) binding site (e.g., local energy minimum) exists in the outer vestibule of voltage-gated K(+) channels. We suggest that this site is the location of K(+) hydration/dehydration postulated to exist based on the structural studies of KcsA. Finally, neutralization of position 356 enhanced outward K(+) current magnitude, but did not influence the ability of internal K(+) to enter the pore. These data indicate that in Kv2.1, exit of K(+) from the selectivity filter, rather than entry of internal K(+) into the channel, limits outward current magnitude. We discuss the implications of these findings in relation to the structural basis of channel conductance in different K(+) channels.     

Molecular characterization of Cryptosporidium isolates from humans and animals in Iran

Isolates of Cryptosporidium spp. from human and animal hosts in Iran were characterized on the basis of both the 18S rRNA gene and the Laxer locus. Three Cryptosporidium species, C. hominis, C. parvum, and C. meleagridis, were recognized, and zoonotically transmitted C. parvum was the predominant species found in humans.     

Relationship between the Structure and Chaperone Activity of Human αA-Crystallin after Its Modification with Diabetes-Associated Oxidative Agents and Protective Role of Antioxidant Compounds

Biochemistry (Moscow) - The study was aimed to evaluate the impact of peroxynitrite (PON, oxidative stress agent in diabetes), methylglyoxal (MGO, diabetes-associated reactive carbonyl compound),...     

T and B-cell epitopes prediction of Iranian saffron (Crocus sativus) profilin by bioinformatics tools

Plant profilins form a well-known panallergen family responsible for cross-sensitization between plant foods and pollens. We sought to map T and B-cell epitopes on the Iranian Crocus sativus profilin by bioinformatics tools. The predicted peptides are useful for further vaccine development.     

Detection of plasmid-mediated quinolone resistance in clinical isolates of Enterobacteriaceae strains in Hamadan,West of Iran

Plasmid mediated quinolone resistance (PMQR) determinants have arisen as a significant concern in recent years. The aim of this study was screening of resistant-clinical isolates to fluoroquinolone antibiotics and detection of qnr and aac(6′)-Ib-cr genes.For this purpose we collected 100 fluoroquinolone-resistant Enterobacteriaceae which were from 3 hospitals in Hamadan, west provinces of Iran, between October 2012 and June 2013. The all samples were identified by biochemical tests and confirmed by PCR method. Antimicrobial susceptibility to 14 antimicrobial agents including levofloxacin and ciprofloxacin were determined by disk diffusion methods and ciprofloxacin MIC was obtained by broth microdilution method as Clinical Laboratory Standards Institute (CLSI) recommendations. The isolates were screened for the presence of qnrA, qnrB, qnrS and aac(6′)-Ib-cr genes using PCR assay. Among the screened isolates, 64 strains (64%) of Escherichia coli, 23 strains (23%) of Klebsiella pneumoniae, 13 strains (13%) of Proteus mirabilis were collected as quinolone-resistant isolates. out of 100 isolates, two (2%) were positive for qnrS, seventeen (17%) isolates were positive for qnrB and we did not find qnrA gene in any of the isolates. There were also 32 positive isolates for aac(6′)-Ib-cr determinant. We described the prevalence of qnr and aac(6′)-Ib-cr genes in fluoroquinolone-resistant Enterobacteriaceae in Hamadan city. The carriage rate of multidrug-resistant Enterobacteriaceae in healthy people in Hamadan City is extremely high. Moreover, genes encoding transferable quinolones, in particular aac(6′)-Ib-cr, are highly prevalent in these strains.     

IL-35, a double-edged sword in cancer

Interleukin 35 (IL-35), a cytokine mainly produced by regulatory T cells (Treg cells), is composed of an Epstein-Barr virus–induced gene 3 β-chain and an IL-12 p35 α-chain. IL-35 causes tumorigenicity in cancer, protects cancer cells against apoptosis, and facilitates cancer progression. However, a few reports have referred to its contradictory roles in cancer prevention. Therefore, the exact purpose of this cytokine in cancer development has become a fundamental question that needs to be answered. In this review, we explain the structure of IL-35 and its receptors and their different signaling pathways. Finally, the function of IL-35 in some cancers and the possible application of this cytokine in approaches for cancer therapy have been discussed.     

The role of the mitochondrion in plant responses to biotic stress

Recent studies suggest that the plant mitochondrion may play a role during biotic stress responses, such as those occurring during incompatible plant–pathogen interactions. There are indications that signal molecules or pathways initiated by such interactions may directly or indirectly target mitochondrial components and that an important consequence of this targeting is an early disruption of mitochondrial homeostasis, resulting in an increased generation of mitochondrial reactive oxygen species (mROS). These mROS may then initiate further mitochondrial dysfunction and further mROS generation in a self-amplifying manner. The mROS, as well as the graded dysfunction of the mitochondrion may act as cellular signals that initiate graded cellular responses ranging from defense gene induction to initiation of programmed cell death. However, these events may be attenuated by the unique components of the plant electron transport chain that act to substitute for dysfunctional components, dampen mROS generation or facilitate in defining the cellular level of ROS and antioxidant defense systems.