Effect of NMDA receptor agonist and antagonist on spermatogonial stem cells proliferation in 2- and 3- dimensional culture systems

Molecular Biology Reports - The main purpose of this study was to investigate the effect of D-serine (DS) and Dizocilpine (MK-801) on the proliferation of spermatogonial stem cells (SSCs) in...     

Prevalence of Non-Tuberculosis Mycobacterial Infections among Tuberculosis Suspects in Iran: Systematic Review and Meta-Analysis

Introduction

The infections due to Non-Tuberculosis Mycobacteria (NTM) are becoming an important health problem in many countries in the world. Globally, an increase in NTM infections has been reported from many countries around the world. However, limited information is available about the prevalence of NTM infections in Iran.

Material and Methods

The data of the prevalence of NTM infections were collected from databases such as PubMed, Web of science, Cochrane Library, Embase, Scopus, Iranmedex, and Scientific Information Database. Comprehensive Meta-Analysis (V2.0, Biostat) software was used to analyze the data.

Results

The meta-analyses showed that the prevalence of NTM infections was 10.2% (95% confidence interval [95% CI] 6.3-15.9) among culture-positive cases of tuberculosis (TB) in Iran. The further stratified analyses indicated that the prevalence of NTM was higher in studies that were done after year 2000. Additionally, M. simiae (43.3% [95% CI 36.8-50.0]), M. intracellucar (27.3% [95% CI 0.7-95.5]) and M. fortuitum (22.7% [95% CI 16.1-30.9]) were the most prevalent NTM species, respectively.

Discussion

The relatively high prevalence of NTM infections (10.2%) among culture positive cases for TB underlines the need for greater enforcement of infection control strategies. Establishment of appropriate diagnostic criteria and management guidelines for NTM diseases and expanding the number and quality of regional reference laboratories may facilitate more accurate action for prevention and control of NTM infections in Iran.     

Kinetic, thermodynamic and statistical studies on the inhibition of adenosine deaminase by aspirin and diclofenac

The kinetic and thermodynamic effects of aspirin and diclofenac on the activity of adenosine deaminase (ADA) were studied in 50 mM phosphate buffer pH = 7.5 at 27 and 37 degrees C, using UV-Vis spectrophotometry and isothermal titration calorimetry (ITC). Aspirin exhibits competitive inhibition at 27 and 37 degrees C and the inhibition constants are 42.8 and 96.8 microM respectively, using spectrophotometry. Diclofenac shows competitive behavior at 27 degrees C and uncompetitive at 37 degrees C with inhibition constants of 56.4 and 30.0 microM, at respectively. The binding constant and enthalpy of binding, at 27 degrees C are 45 microM, - 64.5 kJ/mol and 61 microM, - 34.5 kJ/mol for aspirin and diclofenac. Thermodynamic data revealed that the binding process for these ADA inhibitors is enthalpy driven. QSAR studies by principal component analysis implemented in SPSS show that the large, polar, planar, and aromatic nucleoside and small, aromatic and polar non-nucleoside molecules have lower inhibition constants.     

Novel Bacteriophages in Enterococcus spp.

Most of the bacteriophages (phages) currently reported in Enterococcus spp. belong to tailed families of bacteriophages Podoviridae, Siphoviridae, and Myoviridae. There is a little information on non-tailed bacteriophages isolated from enterococci. Samples of sewage and piggery effluents were tested on pig and chicken isolates of Enterococcus faecalis, E. faecium and E. gallinarum for lytic phages. In addition, isolates were exposed to mitomycin C to induce lysogenic phages. Bacteriophages that were detected were visualized by electron microscopy. Ten bacteriophages were of isometric shape with long flexible or non-flexible tails, while one had a long head with a long flexible tail; all contained double-stranded DNA molecules. Seven Polyhedral, filamentous, and pleomorphic-shaped phages containing DNA or RNA were also observed. The pleomorphic phages were droplet- or lemon-shaped in morphology. This study is the first report on polyhedral phages in Enterococcus spp. of animal origin and also the first report of filamentous and pleomorphic phages in enterococci.     

Ligands specify estrogen receptor alpha nuclear localization and degradation

Background  

The estrogen receptor alpha (ERα) is found predominately in the nucleus, both in hormone stimulated and untreated cells. Intracellular distribution of the ERα changes in the presence of agonists but the impact of different antiestrogens on the fate of ERα is a matter of debate.     

Overlapping Genes May Control Reprogramming of Mouse Somatic Cells into Induced Pluripotent Stem Cells (iPSCs) and Breast Cancer Stem Cells

Recent findings suggest the possibility that tumors originate from cancer cells with stem cell properties. The cancer stem cell (CSC) hypothesis provides an explanation for why existing cancer therapies often fail in eradicating highly malignant tumors and end with tumor recurrence. Although normal stem cells and CSCs both share the capacity for self-renewal and multi-lineage differentiation, suggesting that CSC may be derived from normal SCs, the cellular origin of transformation of CSCs is debatable. Research suggests that the tightly controlled balance of self-renewal and differentiation that characterizes normal stem cell function is dis-regulated in cancer. Additionally, recent evidence has linked an embryonic stem cell (ESC)-like gene signature with poorly differentiated high-grade tumors, suggesting that regulatory pathways controlling pluripotency may in part contribute to the somatic CSC phenotype. Here, we introduce expression profile bioinformatic analyses of mouse breast cells with CSC properties, mouse embryonic stem (mES) and induced pluripotent stem (iPS) cells with an emphasis on how study of pluripotent stem cells may contribute to the identification of genes and pathways that facilitate events associated with oncogenesis. Global gene expression analysis from CSCs and induced pluripotent stem cell lines represent an ideal model to study cancer initiation and progression and provide insight into the origin cancer stem cells. Additionally, insight into the genetic and epigenomic mechanisms regulating the balance between self-renewal and differentiation of somatic stem cells and cancer may help to determine whether different strategies used to generate iPSCs are potentially safe for therapeutic use.     

Characterization of Bacteria by Gas Chromatography: Comparison of Trimethylsilyl Derivatives of Whole-Cell Hydrolysates

A method for the formation of the trimethylsilyl (TMS) derivatives of the whole-cell hydrolysate of bacteria was developed. The TMS derivatives were examined by gas-liquid chromatography. TMS profiles of various bacteria at the genus and species level were compared. Differences in TMS profiles of Listeria, Neisseria, and Clostridium were significant as were differences between the TMS profiles of C. perfringens and C. sporogenes. Two types of C. perfringens, two serotypes of L. monocytogenes, and one culture of C. sporogenes and N. meningitidis were studied. The possible application of TMS profiles as an aid in differentiating closely related organisms which are troublesome to separate by conventional means is discussed.     

Gold or silver deposited on layered manganese oxide: a functional model for the water-oxidizing complex in photosystem II

In this report, gold or silver deposited on layered manganese oxide has been synthesized by a simple method and characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectrometry, atomic absorption spectroscopy, and energy-dispersive X-ray mapping. The gold deposited on layered manganese oxide showed efficient catalytic activity toward water oxidation in the presence of cerium(IV) ammonium nitrate. The properties associated with this compound suggest it is a functional model for the water-oxidizing complex in photosystem II.     

Natural bond orbital, nuclear magnetic resonance analysis and hybrid-density functional theory study of σ-aromaticity in Al2F6, Al2Cl6, Al2Br6 and Al2I6

Natural bond orbital (NBO), nuclear magnetic resonance (NMR) analysis and hybrid-density functional theory based method (B3LYP/Def2-TZVPP) were used to investigate the correlation between the nucleus-independent chemical shifts [NICS, as an aromaticity criterion], σ _Al(1)-X2(b) → σ*_Al(3)-X4(b) electron delocalizations and the dissociation energies of Al₂F₆, Al₂Cl₆, Al₂Br₆ and Al₂I₆ to 2AlX₃ (X?=?F, Cl, Br, I). The results obtained showed that the dissociation energies of Al₂F₆, Al₂Cl₆, Al₂Br₆ and Al₂I₆ decrease from Al₂F₆ to Al₂I₆. Like aromatic molecules, these compounds have relatively significant negative NICS_iso(0) values. Clearly, based on magnetic criteria, they exhibit aromatic character and make it possible to consider them as σ-delocalized aromatic species, such as Möbius σ-aromatic species. The σ-aromatic character which is demonstrated by their NICS_iso(0) values decreases from Al₂F₆ to Al₂I₆. The NICS_iso values are dominated by the in-plane σ₂₂ (i.e., σ_yy, the plane containing halogen atoms bridged) chemical shift components. The increase of the NICS_iso values explains significantly the decrease of the corresponding dissociation energies of Al₂F₆, Al₂Cl₆, Al₂Br₆ and Al₂I₆. Importantly, the NBO results suggest that in these compounds the dissociation energies are controlled by the stabilization energies associated with σ _Al(1)-X2(b) →σ*_Al(3)-X4(b) electron delocalizations. The decrease of the stabilization energies associated with σ _Al(1)-X2(b) →σ*_Al(3)-X4(b) electron delocalizations is in accordance with the variation of the calculated NICS_iso values. The correlations between the dissociation energies of Al₂F₆, Al₂Cl₆, Al₂Br₆ and Al₂I₆, σ _Al(1)-X2(b) →σ*_Al(3)-X4(b) electron delocalizations, natural atomic orbitals (NAOs) and NICS_iso values have been investigated.