Genetic diversity among Toxoplasma gondii isolates from different hosts and geographical locations revealed by analysis of ROP13 gene sequences

Toxoplasma gondii can infect almost all the warm-blooded animals and human beings, causing serious public health problems and economic losses worldwide. Rhoptry protein 13 (ROP13) plays some roles in the invasion process of T. gondii. In this study, sequence variation in ROP13 gene among 14 T. gondii isolates from different geographical locations and hosts was examined. The ROP13 gene was amplified from individual isolates and sequenced. Results show that the length of the ROP13 sequences was 1203 bp. In total, there were 44 variable nucleotide positions in the ROP13 sequences, and sequence variations were 0.1 to 2.0% among the 14 examined T. gondii isolates, representing higher rate in transversion than in transition. Intra-specific nucleotide variations were mainly at the second codon positions. Phylogenetic analysis of the 14 examined T. gondii isolates indicate that the ROP13 sequence was not a suitable genetic marker to differentiate T. gondii isolates of different genotypes from different hosts and geographical regions. Low variation in ROP13 gene sequence may suggest that ROP13 gene could represent a good vaccine candidate against toxoplasmosis.Key words: Toxoplasma gondii, toxoplasmosis, rhpotry protein 13 (ROP13), sequence variation, phylogenetic analysis

Myofibrillogenesis regulator 1 (MR-1) is a novel biomarker and potential therapeutic target for human ovarian cancer

<p>Abstract</p> <p>Background</p> <p>Myofibrillogenesis regulator 1 (MR-1) is overexpressed in human cancer cells and plays an essential role in cancer cell growth. However, the significance of MR-1 in human ovarian cancer has not yet been explored. The aim of this study was to examine whether MR-1 is a predictor of ovarian cancer and its value as a therapeutic target in ovarian cancer patients.</p> <p>Methods</p> <p>Reverse-transcription polymerase chain reaction (PCR) and quantitative real-time PCR were used to detect MR-1 mRNA levels in tissue samples from 26 ovarian cancer patients and 25 controls with benign ovarian disease. Anti-MR-1 polyclonal antibodies were prepared, tested by ELISA and western blotting, and then used for immunohistochemical analysis of the tissue samples. Adhesion and invasion of 292T cells was also examined after transfection of a pMX-MR-1 plasmid. Knockdown of MR-1 expression was achieved after stable transfection of SKOV3 cells with a short hairpin DNA pGPU6/GFP/Neo plasmid against the MR-1 gene. In addition, SKOV3 cells were treated with paclitaxel and carboplatin, and a potential role for MR-1 as a therapeutic target was evaluated.</p> <p>Results</p> <p>MR-1 was overexpressed in ovarian cancer tissues and SKOV3 cells. 293T cells overexpressed MR-1, and cellular spread and invasion were enhanced after transfection of the pMX-MR-1 plasmid, suggesting that MR-1 is critical for ovarian cancer cell growth. Knockdown of MR-1 expression inhibited cell adhesion and invasion, and treatment with anti-cancer drugs decreased its expression in cancer cells. Taken together, these results provide the first evidence of the cellular and molecular mechanisms by which MR-1 might serve as a novel biological marker and potential therapeutic target for ovarian cancer.</p> <p>Conclusions</p> <p>MR-1 may be a biomarker for diagnosis of ovarian cancer. It may also be useful for monitoring of the effects of anti-cancer therapies. Further studies are needed to clarify whether MR-1 is an early diagnostic marker for ovarian cancer and a possible therapeutic target.</p

Genome-wide microRNA profiling in human fetal nervous tissues by oligonucleotide microarray

OBJECTS: Our objective was to develop an oligonucleotide DNA microarray (OMA) for genome-wide microRNA profiling and use this method to find miRNAs, which control organic development especially for nervous system. MATERIALS AND METHODS: Eighteen organic samples included cerebrum and spinal cord samples from two aborted human fetuses. One was 12 gestational weeks old (G12w) and the other was 24 gestational weeks old (G24w). Global miRNA expression patterns of different organs were investigated using OMA and Northern blot. CONCLUSION: The OMA revealed that 72–83% of miRNAs were expressed in human fetal organs. A series of microRNAs were found specifically and higher-expressed in the human fetal nervous system and confirmed consistently by Northern blot, which may play a critical role in nervous system development

In situ epitaxial engineering of graphene and h-BN lateral heterostructure with a tunable morphology comprising h-BN domains

Graphene and hexagonal boron nitride (h-BN), as typical two-dimensional (2D) materials, have long attracted substantial attention due to their unique properties and promise in a wide range of applications. Although they have a rather large difference in their intrinsic bandgaps, they share a very similar atomic lattice; thus, there is great potential in constructing heterostructures by lateral stitching. Herein, we present the in situ growth of graphene and h-BN lateral heterostructures with tunable morphologies that range from a regular hexagon to highly symmetrical star-like structure on the surface of liquid Cu. The chemical vapor deposition (CVD) method is used, where the growth of the h-BN is demonstrated to be highly templated by the graphene. Furthermore, large-area production of lateral G-h-BN heterostructures at the centimeter scale with uniform orientation is realized by precisely tuning the CVD conditions. We found that the growth of h-BN is determined by the initial graphene and symmetrical features are produced that demonstrate heteroepitaxy. Simulations based on the phase field and density functional theories are carried out to elucidate the growth processes of G-h-BN flakes with various morphologies, and they have a striking consistency with experimental observations. The growth of a lateral G-h-BN heterostructure and an understanding of the growth mechanism can accelerate the construction of various heterostructures based on 2D materials

D-Ribose Induces Cellular Protein Glycation and Impairs Mouse Spatial Cognition

BACKGROUND: D-ribose, an important reducing monosaccharide, is highly active in the glycation of proteins, and results in the rapid production of advanced glycation end products (AGEs) in vitro. However, whether D-ribose participates in glycation and leads to production of AGEs in vivo still requires investigation. METHODOLOGY/PRINCIPAL FINDINGS: Here we treated cultured cells and mice with D-ribose and D-glucose to compare ribosylation and glucosylation for production of AGEs. Treatment with D-ribose decreased cell viability and induced more AGE accumulation in cells. C57BL/6J mice intraperitoneally injected with D-ribose for 30 days showed high blood levels of glycated proteins and AGEs. Administration of high doses D-ribose also accelerated AGE formation in the mouse brain and induced impairment of spatial learning and memory ability according to the performance in Morris water maze test. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that D-ribose but not D-glucose reacts rapidly with proteins and produces significant amounts of AGEs in both cultured cells and the mouse brain, leading to accumulation of AGEs which may impair mouse spatial cognition

An alternative route for the synthesis of silicon nanowires via porous anodic alumina masks

Amorphous Si nanowires have been directly synthesized by a thermal processing of Si substrates. This method involves the deposition of an anodic aluminum oxide mask on a crystalline Si (100) substrate. Fe, Au, and Pt thin films with thicknesses of ca. 30 nm deposited on the anodic aluminum oxide-Si substrates have been used as catalysts. During the thermal treatment of the samples, thin films of the metal catalysts are transformed in small nanoparticles incorporated within the pore structure of the anodic aluminum oxide mask, directly in contact with the Si substrate. These homogeneously distributed metal nanoparticles are responsible for the growth of Si nanowires with regular diameter by a simple heating process at 800°C in an Ar-H2 atmosphere and without an additional Si source. The synthesized Si nanowires have been characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman