Search

We investigated the effect of all-trans retinoic acid (ATRA) alone and in combination with interferon-alpha (IFN-alpha) on the granulocyte-macrophage (GM) colony formation of peripheral blood progenitors isolated from patients with chronic myeloid leukemia (CML) (n = 12) or other myeloproliferative disorders (n = 10) as well as from healthy controls (n = 7). The ATRA or IFN-alpha alone inhibited slightly, but not significantly, the GM colony growth in CML. Granulocyte-macrophage colony formation decreased significantly (P

In the present study, the ability of peripheral blood (PB) progenitor cells to form granulocyte-macrophage (GM) colonies spontaneously in methylcellulose was investigated in healthy controls and patients with myeloproliferative disorders (MPDs). Spontaneous colony formation was observed in only one of the 18 control cases (6%), but in 22 of the 29 MPD patients (76%). The incidence of spontaneous GM colonies correlated both with the number of blast cells and the amount of c-kit positive cells present in the initial sample. Spontaneous GM colony growth in PB mononuclear cells isolated from patients with MPDs seems to be a frequent phenomenon in contrast to the healthy controls and may present a marker of malignancy.

Rhizoctonia solani is a major fungal pathogen of rice (Oryza sativa L.) that causes great yield losses in all rice-growing regions of the world. Here we report the draft genome sequence of the rice sheath blight disease pathogen, R. solani AG1 IA, assembled using next-generation Illumina Genome Analyser sequencing technologies. The genome encodes a large and diverse set of secreted proteins, enzymes of primary and secondary metabolism, carbohydrate-active enzymes, and transporters, which probably reflect an exclusive necrotrophic lifestyle. We find few repetitive elements, a closer relationship to Agaricomycotina among Basidiomycetes, and expand protein domains and families. Among the 25 candidate pathogen effectors identified according to their functionality and evolution, we validate 3 that trigger crop defence responses; hence we reveal the exclusive expression patterns of the pathogenic determinants during host infection., The rice sheath blight pathogen, Rhizoctonia solani, is an important fungal pathogen that can devastate rice and maize crops. Zheng and colleagues sequence and assemble the R. solani AG1 IA genome—the first to be sequenced from the Rhizoctonia genus—using Illumina sequencing technology.

Vasoactive intestinal peptide (VIP) is a linear cationic neuropeptide composed of 28 amino acids. It belongs to the glucagon/secretin family. The biological functions of VIP are relatively broad, but it has not been well studied in the field of pharmaceutics. Especially in the selection of the way of VIP administration and the pharmaceutical formulation, the theory basis was deficient appreciably.To provide the theory basis for the pharmaceutical development of VIP, the chemical and biological stability of VIP was studied.The stability of VIP in different pH values, ionic strength, temperature, artificial gastric fluid and artificial intestinal fluid was investigated, and the concentration of VIP was calculated by HPLC method.The stability of VIP was pH-dependent. VIP was stable in acid and neutral solution, and almost didn't degrade during pH ≤ 7 solution. However, it was instability in basic solution and degraded completely at 30 min in pH 13 solution. Ionic strength did not affect its stability. VIP was stable in freezing conditions but it degraded at low concentration in cold storage. Furthermore, VIP degraded so quickly in artificial gastric fluid and artificial intestinal fluid that it can't be detected at 0 min.the chemical and biological characteristic of VIP was unstable, so it isn't suitable for oral administration.

Background The ideal plant architecture (IPA) includes several important characteristics such as low tiller numbers, few or no unproductive tillers, more grains per panicle, and thick and sturdy stems. We have developed an indica restorer line 7302R that displays the IPA phenotype in terms of tiller number, grain number, and stem strength. However, its mechanism had to be clarified. Findings We performed re-sequencing and genome-wide variation analysis of 7302R using the Solexa sequencing technology. With the genomic sequence of the indica cultivar 9311 as reference, 307 627 SNPs, 57 372 InDels, and 3 096 SVs were identified in the 7302R genome. The 7302R-specific variations were investigated via the synteny analysis of all the SNPs of 7302R with those of the previous sequenced none-IPA-type lines IR24, MH63, and SH527. Moreover, we found 178 168 7302R-specific SNPs across the whole genome and 30 239 SNPs in the predicted mRNA regions, among which 8 517 were Non-syn CDS. In addition, 263 large-effect SNPs that were expected to affect the integrity of encoded proteins were identified from the 7302R-specific SNPs. SNPs of several important previously cloned rice genes were also identified by aligning the 7302R sequence with other sequence lines. Conclusions Our results provided several candidates account for the IPA phenotype of 7302R. These results therefore lay the groundwork for long-term efforts to uncover important genes and alleles for rice plant architecture construction, also offer useful data resources for future genetic and genomic studies in rice. Electronic supplementary material The online version of this article (doi:10.1186/1939-8433-5-18) contains supplementary material, which is available to authorized users.

Rice restorer lines play an important role in three-line hybrid rice production. Previous research based on molecular tagging has suggested that the restorer lines used widely today have narrow genetic backgrounds. However, patterns of genetic variation at a genome-wide scale in these restorer lines remain largely unknown. The present study performed re-sequencing and genome-wide variation analysis of three important representative restorer lines, namely, IR24, MH63, and SH527, using the Solexa sequencing technology. With the genomic sequence of the Indica cultivar 9311 as the reference, the following genetic features were identified: 267,383 single-nucleotide polymorphisms (SNPs), 52,847 insertion/deletion polymorphisms (InDels), and 3,286 structural variations (SVs) in the genome of IR24; 288,764 SNPs, 59,658 InDels, and 3,226 SVs in MH63; and 259,862 SNPs, 55,500 InDels, and 3,127 SVs in SH527. Variations between samples were also determined by comparative analysis of authentic collections of SNPs, InDels, and SVs, and were functionally annotated. Furthermore, variations in several important genes were also surveyed by alignment analysis in these lines. Our results suggest that genetic variations among these lines, although far lower than those reported in the landrace population, are greater than expected, indicating a complicated genetic basis for the phenotypic diversity of the restorer lines. Identification of genome-wide variation and pattern analysis among the restorer lines will facilitate future genetic studies and the molecular improvement of hybrid rice.

The target pathogen Villosiclava virens (teleomorph: claviceps oryzae-sativae) was isolated from the infected rice, where it caused false smut. In our study, the forming processes of the chlamydospores, chlamydospore balls, conidiospores, and secondary conidiospores during the asexual reproduction were observed more precisely and in greater detail than previous descriptions. The microstructure of the infected rice kernel showed that the outer dense chlamydospores piled around the false smut balls grown on XBZ medium; moreover the sclerotia consisting of dense mycelium were found. The different morphology was observed across the different growing conditions. In addition, we observed the nuclear numbers of both the conidiospores and hyphae using 4',6-diamidino-2-phenylindole (DAPI) staining. Because the fungus has small chromosomes and the numbers were not previously known, we analyzed the electrophoretic karyotype using a pulsed field gel electrophoresis (PFGE) technique. The results showed that V. virens has at least 10 chromosomes ranging in size from 0.6 kb to 6 Mb. The V. virens genome size is estimated to be 23 Mb. Here, we report the morphological characteristics of the fungus and the process of asexual spores forming asexual propagules, along with the first analyze the molecular karyotype of V. virens. These results supply a foundation for further study of the pathogenicity and biology of this devastating pathogen.

The binding between two universally conserved translation initiation factors, eIF5B and eIF1A, is important in the initiation step of eukaryotic protein synthesis on the ribosome. Through this interaction, eIF1A assists in recruiting eIF5B to the initiating 40S subunit; eIF5B then encourages the joining of the 60S subunit to form an initiating 80S ribosome. Here, the expression, purification, crystallization and preliminary X-ray analyses of eIF5BΔN and the eIF5BΔN-eIF1AΔN complex from Saccharomyces cerevisiae are reported. The crystal of eIF5BΔN diffracted to 2.45 Å resolution and belonged to space group P4(1)2(1)2, with unit-cell parameters a = b = 130.0, c = 71.7 Å. The asymmetric unit was estimated to contain one molecule. The initial phase was obtained by Se-SAD. The crystal of the eIF5BΔN-eIF1AΔN complex diffracted to 3.3 Å resolution and belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 101.9, b = 120.9, c = 132.8 Å. The asymmetric unit was estimated to contain two complex molecules.

A novel solid adsorption refrigerator driven by solar energy, which adopted activated carbon fiber and ethanol as its adsorption pair, has been designed. The constant refrigerating process, different components of the machine and the theoretical feasibility analysis of the refrigeration system are discussed in detail. As the adsorbent bed, the rotary ripple board is designed and it is the key part of this rotary solid adsorption refrigerator. In order to increase the utilization efficiency of the low-temperature heat resource such as solar heat and waste heat, structure of the adsorbent bed was optimized to enhance the heat and mass transfer performance of the refrigerant in the adsorbent bed. The mass transfer process during the course of adsorption and desorption is improved due to an increase in the adsorption rate. Results indicate that the solar solid adsorption refrigerating or air conditioning for tropical locations as residential applications is feasible and can replace conventional vapor compression systems, thus reducing the need of energy systems based on fossil fuel for cooling purposes.

Sichuan basin, situated in the west of China, is the fourth biggest basin in China. In order to describe a systematic study of the cry2-type genes resources from Bacillus thuringiensis strains of Sichuan basin, a total of 791 Bacillus thuringiensis strains have been screened from 2650 soil samples in different ecological regions. The method of PCR-restriction fragment length polymorphism (PCR-RFLP) was used to identify the type of cry2 genes. The results showed that 322 Bacillus thuringiensis strains harbored cry2-type genes and four different RFLP patterns were found. The combination of cry2Aa/cry2Ab genes was the most frequent (90.4%), followed by cry2Aa (6.8%) and cry2Ab alone (2.5%), and only one novel type of cry2 gene was cloned from one isolate (JF19-2). The full-length of this novel gene was obtained by the method of thermal asymmetric interlaced PCR (Tail-PCR), which was designated as cry2Ag1 (GenBank No. ACH91610) by the Bt Pesticide Crystal Protein Nomenclature Committee. In addition, the result of scanning electron microscopic (SEM) observation showed that these strains had erose, spherical, bipyramidal, and square crystal. And the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that these strains harbored about one to three major proteins. These strains exhibited a wide range of insecticidal spectrum toxic to Aedes aegypti (Diptera) and Pieris rapae Linnaeus, 1758 (Lepidoptera). Particularly, JF19-2 contained cry2Ag gene had the highest insecticidal activity. All these researches mentioned above revealed the diversity and particularity of cry2-type gene resources from Bacillus thuringiensis strains in Sichuan basin.

With the development of information technology, web-based instruction is put into practice in China's higher learning institutions nationwide. This paper aims to explore the factors affecting students' use of the learning system The technology acceptance model is employed as the theoretical basis and questionnaire is used to measure the hypothetical model. And prior computer experience exerts significant influence on perceived ease of use, while excluding perceived usefulness. However, teaching content and communication variables produce direct influence on actual use of the system. From the results, some implication and suggestions can be provided, all these aspects considered, teachers could control these external variables and promote learner's internal perceptions. And then this could contribute to frequent usage behavior. In all, the self-access English learning system can be a successful and effective instruction model. Since the autumn of 2007 Self Access English Learning System is put into our research team use in Northwest A&F University. The questionnaire, interview, and longitudinal study conducted by our research show that, on the whole, the students' language learning ability improves dramatically with modern information technology, especially in aspects of speaking and listening. And learner autonomy has been enhanced considerably. Some problems that call for attention are respect.

We characterized a novel Bacillus thuringiensis isolate native to China (HS18-1) that shows a spherical crystal harboring two major proteins of about 70 and 130 kDa, and contains three novel cry genes (cry4Cb1, cry30Ga1, cry54-type). Furthermore, the cry4Cb1 and cry30Ga1 genes were expressed in Escherichia coli BL21 (DE3): pLysS. Insecticidal activity tests showed that the cry4Cb1 protein exhibited larvicidal activity against Aedes aegypti (Diptera) and the cry30Ga1 protein was toxic to both A. aegypti and P. xylostella (Lepidoptera).

In order to systematically investigate the cry gene resources from Bacillus thuringiensis (Bt) in different ecological regions in Sichuan Basin and further clone novel cry genes.We used the methods of microscopic and scanning electron microscopic observation, PCR-restriction fragment length polymorphism (PCR-RFLP) analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and test of insecticidal activities to research Bt strains collected in this basin.We screened 791 Bt isolates from 2650 soil samples, and found cryl, cry2, cry3, cry4/10, cry9, cry30, and cry40-type genes in this basin. Strains containing cryl genes were the most abundant in our collection (66%), and 21 different cry1-type gene combinations were found. Furthermore, several novel holotype cry genes were found and the full-length sequences of 3 novel cry genes were designated as cry54Aa1, cry30Fa1, and cry30 Ga1 by B. thuringiensis Pesticidal Crystal Protein Nomenclature Committee. The results of insecticidal activities showed that Sichuan Basin harbored Bt isolates with insecticidal activities. SDS-PAGE assay of 80 strains without PCR products indicated that these strains may harbor potentially novel cry proteins gene.The diversity and particularity of cry gene resources in Sichuan Basin have important meanings in theories and practices.

We characterized strain Rpp39 isolated from the soil of Sichuan, China. A type of cry2Aa gene was cloned and expressed in E. coli. METHODS; We characterized strain Rpp39 by scanning electron microscope, PCR-RFLP identification and SDS-PAGE analysis. We cloned cry2Aa gene by PCR clone. We constructed the recombinant plasmid pET-2Aa, and transformed E.coli.BL21 (DE3) to express by IPTG. We determined the toxicity of expressed products to the larvae of Plutella xylostella and Chilo supperssalis through bioassay.The strain Rpp39 contained three types parasporal crystals, diamond, squareness and round, observed under the scanning electron microscope. SDS-PAGE analysis showed that two kinds of molecular mass of insecticidal crystal proteins, one was about 130kD and the other 60 kDa, were expressed in isolate Rpp39. The strain contained cry1Aa, cry1Ab, cry1Ac, cry1Ia and cry2Aa gene, analyzed by the PCR-RFLP method. One cry2Aa-type gene of Rpp39 was cloned and designated as cry2Aa12 by Bacillus thuringiensis Insecticidal Crystal Proteins Nomenclature Committee. Sequence analysis revealed that this gene contained an open reading frame of 1902 nucleotides encoding a protein of 634 amino acids. Compared with Cry2Aa1 protein, Cry2Aa12 protein has shown as high as 99.7% amino acid homology. We amplified the full open reading frame sequence of the cry2Aa12 gene by use of a pair of PCR primers P3/P4 designed according to its DNA sequence, and the PCR product was inserted into the Nde I / BamH I site of E. coli expression vector pET-30a to obtain the recombinant plasmid pET-2Aa. The result of SDS-PAGE proved that Cry2Aa12 could be expressed as 65 kDa protein in E. coli BL21(DE3) strain induced by IPTG. We found that Cry2Aa12 was highly toxic to the larvae of Plutella xylostella and Chilo supperssalis through bioassay, with LC50 as 5.4 microg/mL and 22.3 microg/mL, respectively.Strain Rpp39 and cry2Aa12 gene cloned from strain Rpp39 were came from Sichuan ecological condition in China. They could be affluent in the resources of strain and gene. It has important significance to accumulate the resource.

This paper analyzes the advantages and problems existing in network-based language teaching and learning. The result of the research suggests that although there are many advantages in the network-based language teaching and learning, several serious problems still exist in this field. Meanwhile, the main purpose of the paper is to put forward some suggestions to deal with the existing problems and further facilitate network-based teaching and learning. The result of the research will benefit teachers, students and network designers as well. It is hoped that this study will throw light on network-based English language teaching and learning and give a hint to Chinese educational reform.

Rice [Oryza sativa (L.)] feeds more than half of the world’s population. Rhizoctonia solani is a major fungal pathogen of rice causing extreme crop losses in all rice-growing regions of the world. R. solani AG1 IA is a major cause of sheath blight in rice. In this study, we constructed a comprehensive and user-friendly web-based database, RSIADB, to analyse its draft genome and transcriptome. The database was built using the genome sequence (10 489 genes) and annotation information for R. solani AG1 IA. A total of six RNAseq samples of R. solani AG1 IA were also analysed, corresponding to 10, 18, 24, 32, 48 and 72 h after infection of rice leaves. The RSIADB database enables users to search, browse, and download gene sequences for R. solani AG1 IA, and mine the data using BLAST, Sequence Extractor, Browse and Construction Diagram tools that were integrated into the database. RSIADB is an important genomic resource for scientists working with R. solani AG1 IA and will assist researchers in analysing the annotated genome and transcriptome of this pathogen. This resource will facilitate studies on gene function, pathogenesis factors and secreted proteins, as well as provide an avenue for comparative analyses of genes expressed during different stages of infection. Database URL: http://genedenovoweb.ticp.net:81/rsia/index.php

In the present study, the effects of 9-cis retinoic acid (RA) and 13-cis RA on acute myeloblastic leukaemia (AML) cell growth and the induction of apoptosis as well as its relationship with bcl-2 and p53 were compared with those of all-trans RA (ATRA). The study was performed with the subclones of the retinoid-sensitive OCI/AML-2 cell line. The most prominent inhibitory effect on clonogenic cell growth and morphological apoptosis was shown by 9-cis RA. In addition, Western blotting revealed the most obvious translocation of p53 from cytosol to nucleus in the case of 9-cis RA, which was the only retinoid able to change the conformation of p53 from mutational to wild type, as demonstrated by flow cytometry. There was no difference between the retinoids in the downregulation of bcl-2 as analysed by Western blotting and flow cytometry. The RA receptor (RAR)-alpha antagonist had no effect on apoptosis in any of the three retinoids studied using the annexin V method. In conclusion, this study shows that 9-cis RA was a more potent agent than ATRA or 13-cis RA in inducing growth arrest and apoptosis in the OCI/AML-2 subclones. The effect was associated with the downregulation of bcl-2 and was hardly mediated through the RAR-alpha receptor, but might be related to the activation of p53.

The present study investigated whether all-trans retinoic acid (ATRA)-induced apoptosis in acute myeloblastic leukaemia (AML) is related to changes in mitochondrial function. Two human AML cell lines, OU-AML-3 and OU-AML-7, known to be inducible to time-dependent apoptosis of varying degrees by ATRA, were used. Apoptosis induced by ATRA was shown to be a slow event. It was detected by the DNA electrophoretic method and cytofluorimetrical annexin V assay after 48 h exposure, and by morphology and polyADPribose polymerase (PARP) cleavage after 72 h exposure of AML cells to ATRA. The efflux of mitochondrial cytochrome c to cytosol was notable in Western blotting after 48 h exposure of the cells to ATRA and was observed before the drop in the mitochondrial membrane potential, which only took place after 72 h exposure, when measured by flow cytometry and a JC-1 probe. The apoptotic events in mitochondria were more evident in the OU-AML-3 than the OU-AML-7 cell line. This might relate to the different bcl-2 contents of the cell lines: the basic bcl-2 levels of the OU-AML-7 cell line were almost twofold compared to that of the OU-AML-3 cell line, as analysed by the ELISA method. However, both of the cell lines showed progressive down-regulation of bcl-2, which began after 12–24 h exposure of the cells to ATRA as determined by ELISA, Western blotting and flow cytometry. The present results show that mitochondria have a role in ATRA-induced apoptosis in AML cells and down-regulation of bcl-2 is related to it. In view of the previously published studies, the present results underline the fact that the timing of apoptotic events, such as fragmentation of DNA, externalization of phosphatidylserine, cytochrome c efflux, change in mitochondrial membrane potential and cleavage of PARP, are, to a notable extent, cell type and inducer-dependent.

The aim of the present work was to investigate whether acute myeloblastic leukaemia (AML) blast cells express a soluble (s) form of interleukin 6 (IL-6) receptor (R), and if they do, what is the mechanism of production. Eight AML patient cell lines and 25 primary AML blast cell samples were investigated. The cell lines secreted high quantities of sIL-6R into their culture medium when examined by enzyme-linked immunosorbent assay (ELISA). To determine whether sIL-6R is synthesized by a mechanism of alternative splicing, RNA was analysed from all the AML blast cell samples by using reverse transcription polymerase chain reaction. In this method, primer sites flanking the transmembrane domain were utilized and the alternatively spliced IL-6R mRNA was distinguished from the non-spliced transcript form by size. All the cell lines and 64% of the primary blast cell samples expressed the alternatively spliced IL-6R mRNA. To confirm the phenomenon of alternative splicing at protein level, cytoplasmic protein fractions of the cell lines were investigated by using a sensitive adaptation of the Western blot method. All the cell lines expressed two IL-6R proteins sized 80 and 50 kDa and corresponding to the membraneous and soluble forms of IL-6R, respectively. In conclusion, the results obtained at both mRNA and protein levels strongly support alternative splicing as a mechanism of sIL-6R production in AML. Because sIL-6R modulates the effects of IL-6 on target cells, differences in sIL-6R expression levels may partially explain the previously observed diversity in IL-6-induced growth responses in AML.

The role of the interleukin-6/interleukin-6 receptor (IL-6/IL-6R) system in regulating blast cell growth in 8 acute myeloblastic leukemia (AML) patient-derived cell lines was investigated. As they all expressed IL-6R and as none of them responded to exogenous IL-6 under conventional serum-supplemented culture conditions, we investigated whether signaling through IL-6R plays any role in maintaining their spontaneous colony growth. This was done by treating the cells with monoclonal antibodies made against the ligand-specific IL-6R alpha-chain or the signal transducer gp130. In serum-supplemented cultures inhibition of gp130 function did not affect the cell line growth, whereas anti-IL-6R alpha-chain antibody reduced colony growth. While some of the cell lines also showed similar growth characteristics in a serum-free environment, some others changed their growth pattern and stopped responding to anti-IL-6R alpha-chain treatment. At the same time, these cell lines also began to respond to exogenously added IL-6 and, interestingly, were stimulated by anti-gp130 antibody. Hence, in some of the blast cells, clonogenic cell growth seemed to be also negatively controlled by an endogenously produced growth-depressing cytokine or cytokines that utilize gp130. All the cell lines, whether cultured in the presence or absence of serum expressed IL-6 both at mRNA and protein level. The current results indicate that AML cells can use IL-6 as a growth stimulating factor, supplied either paracrinely or autocrinely. This could implicate the use of anti-IL-6R alpha-chain antagonists in AML treatment, not IL-6.

The effect of the mast cell growth factor (MGF), also known as stem cell factor, steel factor, and kit ligand, alone or in combination with other GFs on clonogenic blast cell growth in 23 patients with acute myeloblastic leukemia (AML) was investigated. MGF alone enhanced colony formation by about 35%, being clearly stimulatory (>20% increase in colony numbers) in nine patients. The additive effect of MGF on colony growth was observed in combination with interleukin-3 (IL-3). Preincubation of the cells with MGF in suspension did not sensitize them to the effect of IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF, or IL-4 in a clonogenic cell culture assay. Although almost all the blast cell samples expressed the c-kit the receptor for MGF, at the mRNA and/or the protein level, the cells did not necessarily respond to exogenous MGF. On the other hand, blast cells were able to respond to exogenous MGF even when the cells themselves expressed MGF. Neither the expression of MGF nor the response of blast cells to exogenous MGF was related to the capability of the cells to form colonies spontaneously. In conclusion, MGF alone, but especially combined with IL-3, was a potent growth factor for clonogenic blast cells in AML. Autocrine production of MGF by AML blast cells analyzed at the mRNA level was not related to autonomous growth of the cells.

The effect of interleukin-4 (IL-4) on peripheral blood (PB) granulocyte-macrophage (GM) progenitors was investigated in the presence and absence of other hematopoietic growth factors, especially the mast cell growth factor (MGF), in eight healthy controls and in 26 patients with myeloproliferative disorders (MPDs) using a clonogenic cell culture assay. In the controls IL-4 was effective alone, stimulating myeloid colony growth in 50%, while MGF had no effect as a single factor. When either IL-4 or MGF was added to the combination of IL-3, GM-CSF, G-CSF, and IL-6, a statistically significant increase in the colony number was observed. The most potent colony formation took place when all these GFs were combined. In the combinations, the effect of IL-4 was additive, while MGF worked synergistically. In the MPDs, IL-4 had no effect at all on the GM progenitors in the whole group of MPDs or on the different subgroups.