Phosphate and R2D2 restrict the substrate specificity of Dicer-2, an ATP-driven ribonuclease.

Drosophila Dicer-2 generates small interfering RNAs (siRNAs) from long double-stranded RNA (dsRNA), whereas Dicer-1 produces microRNAs (miRNAs) from pre-miRNA. What makes the two Dicers specific for their biological substrates? We find that purified Dicer-2 can efficiently cleave pre-miRNA, but that inorganic phosphate and the Dicer-2 partner protein R2D2 inhibit pre-miRNA cleavage. Dicer-2 contains C-terminal RNase III domains that mediate RNA cleavage and an N-terminal helicase motif, whose function is unclear.

Exome sequencing identifies somatic mutations of DNA methyltransferase gene DNMT3A in acute monocytic leukemia.

Abnormal epigenetic regulation has been implicated in oncogenesis. We report here the identification of somatic mutations by exome sequencing in acute monocytic leukemia, the M5 subtype of acute myeloid leukemia (AML-M5). We discovered mutations in DNMT3A (encoding DNA methyltransferase 3A) in 23 of 112 (20.

Alternate modes of cognate RNA recognition by human PUMILIO proteins.

Human PUMILIO1 (PUM1) and PUMILIO2 (PUM2) are members of the PUMILIO/FBF (PUF) family that regulate specific target mRNAs posttranscriptionally. Recent studies have identified mRNA targets associated with human PUM1 and PUM2. Here, we explore the structural basis of natural target RNA recognition by human PUF proteins through crystal structures of the RNA-binding domains of PUM1 and PUM2 in complex with four cognate RNA sequences, including sequences from p38α and erk2 MAP kinase mRNAs.

Expression of caspase-8 and caspase-9 in rat hippocampus during postnatal development.

The role of caspases in the regulation of apoptosis of neurons during development is well established. An emerging body of evidence indicates that caspases may also play significant roles which are nonapoptotic. We have demonstrated previously that the executor caspase-3 exhibited a unique pattern of spatiotemporal expression in the postnatal rat hippocampal subregions, and the activation of caspase-3 in different hippocampal neurons appeared to have distinct roles during postnatal development.

Metal-free catalysts for hydrogenation of both small and large imines: a computational experiment.

This study extends our previous work of using π-FLP strategy to develop metal-free hydrogenation catalysts. Using small MeN=CMe(2) imine (im1) as a model, we previously designed cat1 and cat2 catalysts. But it is unclear whether they are capable of catalyzing the hydrogenations of bulky imines.

Design, synthesis, and biological evaluation of a biyouyanagin compound library.

Modern drug discovery efforts rely, to a large extent, on lead compounds from two classes of small organic molecules; namely, natural products (i.e., secondary metabolites) and designed compounds (i.

[Expression and clinical significance of TLR9 in ovarian cancer].

Objective: To detect the expression of Toll-like receptor 9 (TLR9) in ovarian cancer, and to explore their clinical significance.

Methods: Western blot method and immunohistochemical staining were used to examine the expression of TLR9 in the ovarian cancer, paracancerous tissues and normal ovarian tissues, obtained during operation from 30 ovarian carcinoma patients and 30 normal non-tumor patients. The relationships of TLR9 with pathological grade, clinical stage, and metastasis of ovarian cancer were statistically analyzed.

Catabolism of branched-chain amino acids in heart failure: insights from genetic models.

Genetic defects in amino acid metabolism are major causes of newborn diseases that often lead to abnormal development and function of the central nervous system. Their direct impact on cardiac development and function has rarely been investigated. Recently, the authors have established that a mitochondrial targeted 2C-type ser/thr protein phosphatase, PP2Cm, is the endogenous phosphatase of the branched-chain alpha keto acid-dehydrogenase complex (BCKD) and functions as a key regulator in branched-chain amino acid catabolism and homeostasis.

Electron dynamics in dye-sensitized solar cells: effects of surface terminations and defects.

The electron dynamics in a TiO(2)/alizarin based dye-sensitized solar cell is studied by a means of ab initio nonadiabatic molecular dynamics. The effects of surface terminations and vacancy defects on photoexcited interfacial electron transfer (ET) and energy relaxation of injected electrons are examined in detail. In particular, we consider three plausible TiO(2) surface terminations which are stable at zero temperature.

Effects of ATPM-ET, a novel κ agonist with partial μ activity, on physical dependence and behavior sensitization in mice.

Aim: to investigate the effects of ATPM-ET [(-)-3-N-Ethylaminothiazolo [5,4-b]-N-cyclopropylmethylmorphinan hydrochloride] on physical dependence and behavioral sensitization to morphine in mice.

Methods: the pharmacological profile of ATPM-ET was characterized using competitive binding and GTPγS binding assays. We then examined the antinociceptive effects of ATPM-ET in the hot plate test.

Prospective identification, isolation, and profiling of a telomerase-expressing subpopulation of human neural stem cells, using sox2 enhancer-directed fluorescence-activated cell sorting.

Sox2 is expressed by neural stem and progenitor cells, and a sox2 enhancer identifies these cells in the forebrains of both fetal and adult transgenic mouse reporters. We found that an adenovirus encoding EGFP placed under the regulatory control of a 0.4 kb sox2 core enhancer selectively identified multipotential and self-renewing neural progenitor cells in dissociates of human fetal forebrain.

Computational identification and characterization of primate-specific microRNAs in human genome.

A number of microRNAs (miRNAs) that are evolutionarily conserved not beyond primate lineage have been identified. These primate-specific miRNAs (ps-miRNAs) may attribute to the difference between high-level primates and non-primate mammals or lower vertebrates. Despite of their importance, the genome-wide miRNA conservation patterns and the properties of these ps-miRNAs are largely elusive.

Knockdown of interferon-induced transmembrane protein 1 (IFITM1) inhibits proliferation, migration, and invasion of glioma cells.

Interferon-induced transmembrane protein 1 (IFITM1) has recently been identified as a new molecular marker in human colorectal cancer. However, its role in glioma carcinogenesis is not known. In this study, we demonstrated that suppression of IFITM1 expression significantly inhibited proliferation of glioma cells in a time-dependent manner.

Mitochondria-specific transgenic overexpression of connexin-43 simulates preconditioning-induced cytoprotection of stem cells.

Aims: We previously reported that preconditioning of stem cells with insulin-like growth factor-1 (IGF-1) translocated connexin-43 (Cx-43) into mitochondria, causing cytoprotection. We posit that these preconditioning effects could be simulated by mitochondria-specific overexpression of Cx-43.

Methods And Results: During IGF-1-induced preconditioning of C57black/6 mouse bone marrow stem cell antigen-1(+) (Sca-1(+)) cells, Cx-43 was mainly translocated onto the mitochondrial inner membrane, which was abrogated by an extracellular signal-regulated kinases 1 and 2 (ERK1/2) blocker PD98059.

miR-200a regulates epithelial-mesenchymal to stem-like transition via ZEB2 and beta-catenin signaling.

The emerging concept of generating cancer stem cells from epithelial-mesenchymal transition has attracted great interest; however, the factors and molecular mechanisms that govern this putative tumor-initiating process remain largely elusive. We report here that miR-200a not only regulates epithelial-mesenchymal transition but also stem-like transition in nasopharyngeal carcinoma cells. We first showed that stable knockdown of miR-200a promotes the transition of epithelium-like CNE-1 cells to the mesenchymal phenotype.

Inhibition of inflammation and carcinogenesis in the lung and colon by tocopherols.

Tocopherols, which exist in alpha, beta, gamma, and delta forms, are antioxidative nutrients also known as vitamin E. Although alpha-tocopherol (alpha-T) is the major form of vitamin E found in the blood and tissues, gamma- and delta-T have been suggested to have stronger anti-inflammatory activities. In the present study, using a tocopherol mixture that is rich in gamma-T (gamma-TmT, which contains 57%gamma-T), we demonstrated the inhibition of inflammation as well as of cancer formation and growth in the lung and colon in animal models.

The catalytic role of N-heterocyclic carbene in a metal-free conversion of carbon dioxide into methanol: a computational mechanism study.

A density functional theory study at the M05-2X(IEFPCM, THF)/6-311+G**//M05-2X/6-31G* level has been conducted to gain insight into the catalytic mechanism of the first metal-free N-heterocyclic carbene (NHC)-catalyzed conversion of carbon dioxide into methanol. Among the various examined reaction pathways, we found that the most favorable leads to the experimentally detected intermediates, including formoxysilane (FOS), bis(silyl)acetal (BSA), silylmethoxide (SMO), and disiloxane (DSO). However, our study also revealed that formaldehyde (CH(2)O), generated from the dissociation of BSA into DSO and CH(2)O via a mechanism somewhat similar to the Brook rearrangement, should be an inevitable intermediate, although it was not reported by the experimentalists.

Umbilical cord-derived mesenchymal stem cells with forced expression of hepatocyte growth factor enhance remyelination and functional recovery in a rat intracerebral hemorrhage model.

Background: Spontaneous intracerebral hemorrhage (ICH) carries a high mortality rate, with survivors commonly left with permanent neurological deficits. Mesenchymal stem cell (MSC) transplantation promotes functional recovery in experimental ICH, and treatment with hepatocyte growth factor (HGF) is beneficial in ischemic stroke.

Objective: We hypothesize that transplantation of MSCs with previous transduction of HGF has an additive effect in promoting neurological recovery through myelin and axonal regeneration.

[Application of damage control surgery strategy in treatment of burn-trauma combined injury].

Objective: To explore the application of damage control surgery (DCS) strategy in the treatment of severe burn-trauma combined injury.

Methods: From January 2004 to December 2009, 28 patients with severe burn-trauma combined injury received salvage treatment according to DCS, including 12 cases of burn combining injury at 2 sites, 6 cases of burn combining injury at 3 sites, and 10 cases of burn combining injury at 4 sites or above. There were 18 males and 10 females with a median age of 39.

[Autogenous platelet-rich plasma gel with acellular xenogeneic dermal matrix for treatment of deep II degree burns].

Objective: To investigate the effectiveness of autogenous platelet-rich plasma (PRP) gel with acellular xenogeneic dermal matrix in the treatment of deep II degree burns.

Methods: From January 2007 to December 2009, 30 cases of deep II degree burns were treated. There were 19 males and 11 females with an average age of 42.

Inactivation of microorganisms in apple juice using an ultraviolet silica-fiber optical device.

Most juices are opaque to ultraviolet (UV) due to the high-suspended solids in them and therefore the conventional UV treatment, generally used for water treatment, cannot be used for treating juices. In order to achieve a high germicidal efficiency of UV processing, an optical device with silica optical fibers for UV light delivery was designed. Its suitability for application could be shown in experiments with Escherichia coli, Lactobacillus brevis, Saccharomyces cerevisiae and naturally contaminating microorganisms as test microorganisms.

Complete genome sequence of the rifamycin SV-producing Amycolatopsis mediterranei U32 revealed its genetic characteristics in phylogeny and metabolism.

Amycolatopsis mediterranei is used for industry-scale production of rifamycin, which plays a vital role in antimycobacterial therapy. As the first sequenced genome of the genus Amycolatopsis, the chromosome of strain U32 comprising 10,236,715 base pairs, is one of the largest prokaryotic genomes ever sequenced so far. Unlike the linear topology found in streptomycetes, this chromosome is circular, particularly similar to that of Saccharopolyspora erythraea and Nocardia farcinica, representing their close relationship in phylogeny and taxonomy.

Embrittlement of metal by solute segregation-induced amorphization.

Impurities segregated to grain boundaries of a material essentially alter its fracture behavior. A prime example is sulfur segregation-induced embrittlement of nickel, where an observed relation between sulfur-induced amorphization of grain boundaries and embrittlement remains unexplained. Here, 48x10(6)-atom reactive-force-field molecular dynamics simulations provide the missing link.