Biomedical subjects

Cheng Lu

Publications and source records attributed to Cheng Lu.

At least 19 recordsLinked to original sources

PubMed2006

Effects of huoxiangzhengqi liquid on enteric mucosal immune responses in mice with Bacillus dysenteriae and Salmonella typhimurium induced diarrhea.

AIM: To explore effects of huoxiangzhengqi liquid (HXZQ) on enteric mucosal immune responses in mice with Bacillus dysenteriae and Salmonella typhimurium induced diarrhea (BSD). METHODS: BSD was induced in Balb/c mice by oral administration with Bacillus dysenteriae and Salmonella typhimurium. HXZQ was administrated from the day of diarrhea induction at dosages of 5.21 g/kg and 0.52 g/kg, respectively. The onset of diarrhea and lasting time were recorded. Peyer's patches and peripheral lymphocytes were prepared for flow cytometry, and levels of TNF-alpha in peripheral blood and enteric tissue homogenates were determined with ELISA. Student's t test was employed for statistics. RESULTS: Mice in BSD group started showing continuous diarrhea on the day of induction until the fourth day when they were sacrificed. Diarrhea in the mice of HXZQ high and low dose groups lasted for 36 and 54 h, respectively. There were more CD4+ and CD8+ cells in peripheral blood, fewer CD4+ cells in Peyer's patches in BSD mice compared to normal mice. Fewer CD4+ and CD8+ cells was shown in the mice in HXZQ high group compared to BSD mice. In Peyer's patch, there were more CD8+ cells in mice in HXZQ high and low dose groups and more CD4+ in mice in HXZQ high group. Higher levels of TNF-alpha in peripheral blood and intestinal tissue homogenates in BSD group were observed. Mice in HXZQ high group showed decreased levels of TNF-alpha in peripheral blood and enteric tissue homogenates. CONCLUSION: The immune regulation of CD4+ and CD8+ cells in Peyer's patch and suppression of TNF-alpha levels in enteric homogenates may partially explain the effect of HXZQ on improvement of BSD.

Animals↗

PubMed2006

Synchronized and sustained release of multiple components in silymarin from erodible glyceryl monostearate matrix system.

Development of sustained delivery systems for herbal medicines was very difficult because of their complexity in composition. The concept of synchronized release from sustained release systems, which is characterized by release of multiple components in their original ratio that defines a herbal medicine, served as the basis for keeping the original pharmacological activity. In this study, erodible matrix systems based on glyceryl monostearate and polyethylene glycol 6000 or poloxamer 188 were prepared to perform strict control on synchronized release of the five active components of silymarin, i.e. taxifolin, silychrystin, silydianin, isosilybin and silybin. The matrix system was prepared by a melt fusion method. Synchronized release was achieved with high similarity factor f(2) values between each two of the five components. Erosion profiles of the matrix were in good correlation with release profiles of the five components, showing erosion-controlled release mechanisms. Through tuning some of the formulation variables, the system can be adjusted for synchronized and sustained release of silymarin for oral administration. In vitro hemolysis study indicated that the synchronized release samples showed a much better stabilizing effect on erythrocyte membrane.

Animals↗

PubMed2006

Characterization of Antheraea pernyi nucleopolyhedrovirus p11 gene, a homologue of Autographa californica nucleopolyhedrovirus orf108.

Antheraea pernyi nucleopolyhedrovirus (ApNPV) p11 gene is 309 bp long, potentially encoding 102 amino acids with a predicted molecular weight of 11.2 kDa. ApNPV p11 gene was cloned into the prokaryotic expression vector pQE-30 and P11 was expressed in E. coli M15. Polyclonal antiserum was made against 6xHis tagged P11 protein expressed in E. coli M15. P11 gene transcription was detected as early as 36 h post-infection (p.i.) in tussah pupa and remain at high level up to 96 h p.i. Structural localization revealed that P11 protein was present in polyhedral inclusion bodies (PIB) dilute alkaline saline (DAS) pellet (P) fractions and occlusion-derived virus (ODV), but not in PIB DAS supernatant (S) fractions and budded virus (BV). These results indicated that P11 was associated with ApNPV structure.

Amino Acid Sequence↗

PubMed2006

The effects of triptolide on enteric mucosal immune responses of DBA/1 mice with collagen-induced arthritis.

For investigating the effects of triptolide on enteric mucosal immune responses of DBA/1 mice with collagen-induced arthritis (CIA), the changes of the Peyer's patches, IEL (intraepithelial lymphocytes), LPL (lamina propria lymphocytes), periphery lymphocytes, and levels of TGF-beta in CIA mice were checked with flow cytometry or ELISA. Our results showed that triptolide could lower the arthritic scores and increase TGF-beta level. Triptolide also had an effect on enteric mucosal immune lymphocytes in Peyer's patch, IEL and LPL of CIA mice. The regulation of enteric mucosal lymphocytes might explain some of the immunosuppressive activities of triptolide.

Animals↗

PubMed2006

MicroRNAs and other small RNAs enriched in the Arabidopsis RNA-dependent RNA polymerase-2 mutant.

The Arabidopsis genome contains a highly complex and abundant population of small RNAs, and many of the endogenous siRNAs are dependent on RNA-Dependent RNA Polymerase 2 (RDR2) for their biogenesis. By analyzing an rdr2 loss-of-function mutant using two different parallel sequencing technologies, MPSS and 454, we characterized the complement of miRNAs expressed in Arabidopsis inflorescence to considerable depth. Nearly all known miRNAs were enriched in this mutant and we identified 13 new miRNAs, all of which were relatively low abundance and constitute new families. Trans-acting siRNAs (ta-siRNAs) were even more highly enriched. Computational and gel blot analyses suggested that the minimal number of miRNAs in Arabidopsis is approximately 155. The size profile of small RNAs in rdr2 reflected enrichment of 21-nt miRNAs and other classes of siRNAs like ta-siRNAs, and a significant reduction in 24-nt heterochromatic siRNAs. Other classes of small RNAs were found to be RDR2-independent, particularly those derived from long inverted repeats and a subset of tandem repeats. The small RNA populations in other Arabidopsis small RNA biogenesis mutants were also examined; a dcl2/3/4 triple mutant showed a similar pattern to rdr2, whereas dcl1-7 and rdr6 showed reductions in miRNAs and ta-siRNAs consistent with their activities in the biogenesis of these types of small RNAs. Deep sequencing of mutants provides a genetic approach for the dissection and characterization of diverse small RNA populations and the identification of low abundance miRNAs.

Arabidopsis↗

PubMed2006

Genomic and genetic characterization of rice Cen3 reveals extensive transcription and evolutionary implications of a complex centromere.

The centromere is the chromosomal site for assembly of the kinetochore where spindle fibers attach during cell division. In most multicellular eukaryotes, centromeres are composed of long tracts of satellite repeats that are recalcitrant to sequencing and fine-scale genetic mapping. Here, we report the genomic and genetic characterization of the complete centromere of rice (Oryza sativa) chromosome 3. Using a DNA fiber-fluorescence in situ hybridization approach, we demonstrated that the centromere of chromosome 3 (Cen3) contains approximately 441 kb of the centromeric satellite repeat CentO. Cen3 includes an approximately 1,881-kb domain associated with the centromeric histone CENH3. This CENH3-associated chromatin domain is embedded within a 3,113-kb region that lacks genetic recombination. Extensive transcription was detected within the CENH3 binding domain based on comprehensive annotation of protein-coding genes coupled with empirical measurements of mRNA levels using RT-PCR and massively parallel signature sequencing. Genes <10 kb from the CentO satellite array were expressed in several rice tissues and displayed histone modification patterns consistent with euchromatin, suggesting that rice centromeric chromatin accommodates normal gene expression. These results support the hypothesis that centromeres can evolve from gene-containing genomic regions.

Centromere↗

PubMed2006

Dissecting Arabidopsis thaliana DICER function in small RNA processing, gene silencing and DNA methylation patterning.

Small RNAs have several important biological functions. MicroRNAs (miRNAs) and trans-acting small interfering RNAs (tasiRNAs) regulate mRNA stability and translation, and siRNAs cause post-transcriptional gene silencing of transposons, viruses and transgenes and are important in both the establishment and maintenance of cytosine DNA methylation. Here, we study the role of the four Arabidopsis thaliana DICER-LIKE genes (DCL1-DCL4) in these processes. Sequencing of small RNAs from a dcl2 dcl3 dcl4 triple mutant showed markedly reduced tasiRNA and siRNA production and indicated that DCL1, in addition to its role as the major enzyme for processing miRNAs, has a previously unknown role in the production of small RNAs from endogenous inverted repeats. DCL2, DCL3 and DCL4 showed functional redundancy in siRNA and tasiRNA production and in the establishment and maintenance of DNA methylation. Our studies also suggest that asymmetric DNA methylation can be maintained by pathways that do not require siRNAs.

DNA Methylation↗

PubMed2006

EPR theoretical study of local molecular structure and thermal expansion coefficient for octahedral Mn2+ centers in zinc fluosilicate.

A theoretical method for studying the inter-relation between electronic and molecular structure has been proposed by diagonalizing the complete energy matrices for a d(5) configuration ion in a trigonal ligand field and considering the second-order and fourth-order EPR parameters D and (a - F) simultaneously. As for ZnSiF(6).6H(2)O:Mn(2+) and ZnSiF(6).6D(2)O:Mn(2+) complex molecules, the local lattice distortion and local thermal expansion coefficient for the octahedral Mn(2+) centers in zinc fluosilicate have been investigated, respectively. The calculations indicate that the local lattice structure around an octahedral Mn(2+) center has an expansion distortion, whether the Mn(2+) ion is doped in ZnSiF(6).6H(2)O or ZnSiF(6).6D(2)O. Moreover, the total tendency of the local lattice expansion distortion will be more and more obvious with the temperature rising, apart from some slight variations at T = 60 K for the ZnSiF(6).6H(2)O. By simulating the two low-symmetry EPR parameters D and (a - F) simultaneously, the local lattice structure parameters R and theta have been determined to vary from 2.204 Angstroms to 2.256 Angstroms and from 53.417 degrees to 52.710 degrees, respectively, in the temperature range 19-297 K for ZnSiF(6).6H(2)O:Mn(2+) and to vary from 2.215 Angstroms to 2.255 Angstroms and from 53.346 degrees to 52.714 degrees, respectively, in the temperature range 50-300 K for ZnSiF(6).6D(2)O:Mn(2+). Subsequently the dependence of local thermal expansion coefficients on the temperature is studied and the corresponding theoretical values of the local thermal expansion coefficients are reported firstly. Some characteristics of local thermal expansion coefficients of Mn(2+) in ZnSiF(6).6H(2)O:Mn(2+) and ZnSiF(6).6D(2)O:Mn(2+) systems are also analyzed.

Journal Article↗

PubMed2006

Sweating the small stuff: microRNA discovery in plants.

The class of small RNAs known as microRNAs (miRNAs) has a demonstrated role in the negative regulation of gene expression in both plants and animals. These small molecules have been shown to play a critical role in a wide range of developmental and physiological pathways. Although hundreds of different miRNAs have now been identified using cloning and computational approaches, characterization of their targets and biological roles has been more limited. New sequencing technologies promise to accelerate the sequencing of small RNAs and additional genetic and genomic strategies are being applied to assess their regulatory function on RNA targets. These technologies will enable the identification of large numbers of small RNAs from diverse species, and comparative genomics approaches based on these data are likely to identify additional miRNAs. Combined with bioinformatics and experimental approaches to separate miRNAs from short-interfering RNAs (siRNAs), the pace of miRNA discovery is likely to accelerate, leading to an improved understanding of miRNA function and biological significance.

MicroRNAs↗

PubMed2006

EST-based profiling and comparison of gene expression in the silkworm fat body during metamorphosis.

The fat body plays key roles in metabolism and sustenance of growth throughout the life of a silkworm, and thus represents a model tissue for studying development and metamorphosis. Analysis of 18,480 ESTs derived from larval and pupal fat body cDNA libraries allowed characterization of gene expression patterns in the fat body during metamorphosis. By Phrap assembling, 6,814 estimated transcription units (TUs) were generated, 2,673 of which contained 60% of the total ESTs and represented 1,366 distinctive known genes. These genes were classified into 14 categories based on their known or putative functions, and most were found to be involved in metabolism and cell defense. Further comparative analysis of the expression profiles revealed that the gene expression patterns in the larval fat body strikingly differed from those in the pupal fat body. From this, we identified a subset of genes potentially associated with metamorphic events such as the formation or destruction of specific tissues, and simultaneously confirmed the stage-specific expression patterns of several identified genes using RT-PCR examination. This work will provide a valuable resource for studying regulatory mechanisms associated with fat body developmental changes and silkworm metamorphosis.

Animals↗

PubMed2006

On the removal of shadows from images.

This paper is concerned with the derivation of a progression of shadow-free image representations. First, we show that adopting certain assumptions about lights and cameras leads to a 1D, gray-scale image representation which is illuminant invariant at each image pixel. We show that as a consequence, images represented in this form are shadow-free. We then extend this 1D representation to an equivalent 2D, chromaticity representation. We show that in this 2D representation, it is possible to relight all the image pixels in the same way, effectively deriving a 2D image representation which is additionally shadow-free. Finally, we show how to recover a 3D, full color shadow-free image representation by first (with the help of the 2D representation) identifying shadow edges. We then remove shadow edges from the edge-map of the original image by edge in-painting and we propose a method to reintegrate this thresholded edge map, thus deriving the sought-after 3D shadow-free image.

Algorithms↗

PubMed2006

Marek's disease virus encodes MicroRNAs that map to meq and the latency-associated transcript.

MicroRNAs (miRNAs) are a class of small (approximately 22-nucleotide) regulatory molecules that block translation or induce degradation of target mRNAs. These have been identified in a wide range of organisms, including viruses. In particular, the oncogenic gammaherpesviruses Kaposi's sarcoma herpesvirus and Epstein-Barr virus encode miRNAs that could potentially regulate either viral or host genes. To determine if Marek's disease virus (MDV), an oncogenic alphaherpesvirus of chickens, encodes miRNAs, we isolated small RNAs from MDV-infected chicken embryo fibroblasts (CEF) and used the 454 Life Sciences sequencing technology to obtain the sequences of 13,679 candidate host and viral small RNAs. Eight miRNAs were found, five of which flank the meq oncogene and three that map to the latency-associated transcript (LAT) region of the genome. The meq gene is unique to pathogenic serotypes of MDV and is transcriptionally active during latency and transformation, and the LAT region of the MDV genome is antisense to the immediate-early gene ICP4. Secondary structure analysis predicted that the regions flanking the miRNAs could form hairpin precursors. Northern blot analysis confirmed expression of all miRNAs in MDV-infected CEF, MDV-induced tumors, and MDV lymphoblastoid cell lines. We propose that the MDV miRNAs function to enable MDV pathogenesis and contribute to MDV-induced transformation of chicken T cells.

Amino Acid Sequence↗

PubMed2006

[Comparison of early embryogenesis between silkworm and Drosophila from both morphology and gene content level].

The diversity of insects has been the focus of many investigations. Research in the early embryonic developmental mechanism of silkworm will promote understanding in early embryonic developmental mechanism of other insects. This paper reviews the differences in early embryonic development of silkworm and Drosophila from both morphology and gene content level. The results not only provide evidences for the study of early embryonic development mechanism in silkworm, but also give clues for the study of insects diversity.

Animals↗

PubMed2006

[Study on the differential gene expression of peripheral CD4+ among rheumatoid arthritis patients of cold or heat syndrome type with or without rheumatoid factor].

OBJECTIVE: To explore the differential gene expression of peripheral CD4+ among rheumatoid arthritis (RA) patients of cold or heat syndrome type with or without rheumatoid factor (RF). METHODS: Differential gene expression of peripheral CD4+ lymphocytes purified from fasting venous blood of RA patients and healthy subjects was studied using gene chip technique. RESULTS: There were 55 differential genes between RA patients with and without RF, mainly involving those related with immune response and signal transduction. In patients with RF, 71 differential genes, mainly related with functional metabolism and immune response, and in those without RF, 70 related with functional metabolism were found between patients of cold and heat syndrome type respectively, all of them were not repetitive with the above-mentioned 55, and only 2 were found repetitive between the 70 and the 71 differential genes, mainly involving functional metabolism. CONCLUSION: The differential genes between RA patients with or without RF are different with those between patients of heat and cold syndrome type, suggesting the TCM syndrome classification has its own basis of gene expression profile.

Adult↗

PubMed2005

Simple sequence repeat-based consensus linkage map of Bombyx mori.

We established a genetic linkage map employing 518 simple sequence repeat (SSR, or microsatellite) markers for Bombyx mori (silkworm), the economically and culturally important lepidopteran insect, as part of an international genomics program. A survey of six representative silkworm strains using 2,500 (CA)n- and (CT)n-based SSR markers revealed 17-24% polymorphism, indicating a high degree of homozygosity resulting from a long history of inbreeding. Twenty-nine SSR linkage groups were established in well characterized Dazao and C108 strains based on genotyping of 189 backcross progeny derived from an F(1) male mated with a C108 female. The clustering was further focused to 28 groups by genotyping 22 backcross progeny derived from an F(1) female mated with a C108 male. This set of SSR linkage groups was further assigned to the 28 chromosomes (established linkage groups) of silkworm aided by visible mutations and cleaved amplified polymorphic sequence markers developed from previously mapped genes, cDNA sequences, and cloned random amplified polymorphic DNAs. By integrating a visible mutation p (plain, larval marking) and 29 well conserved genes of insects onto this SSR-based linkage map, a second generation consensus silkworm genetic map with a range of 7-40 markers per linkage group and a total map length of approximately 3431.9 cM was constructed and its high efficiency for genotyping and potential application for synteny studies of Lepidoptera and other insects was demonstrated.

Animals↗

PubMed2005

Effect of Gui Zhi decoction on enteric mucosal immune in mice with collagen-induced arthritis.

AIM: To explore the effect of Gui Zhi decoction on enteric mucosal immune in type II collagen-induced arthritis (CIA) in DBA mice. METHODS: Eighty DBA/1, weighing 18-22 g, were randomly divided into four groups with 20 in each group: control group, CIA group, treatment groups at high dosage and low dosage (GZH and GZL). CIA was induced by immunization with type II collagen (CII) emulsified with equal complete adjuvant at 0.1 mg CII each mouse. Blood lymphocyte suspension was screened for CD4 and CD8 expression using a flow cytometry, the CD4 and CD8 and secretory IgA (sIgA)-positive cells in enteric lamina propria tested with immunohistochemical staining. Tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1)-beta, and IL-6 concentrations in serum were assayed with RIA. RESULTS: Gui Zhi decoction can lower the arthritic scores and decrease the occurrence of arthritis. The CD4, CD8, and sIgA-positive cells in CIA mice are less than in control mice, and in Gui Zhi decoction at high dosage could restore the lowered CD4- and CD8-positive cells in lamina propria, and at both high and low dosages could increase the lowered sIgA-positive cells in lamina propria, even still lower than in normal mice. In periphery, the CD4 cells in periphery are higher in CIA mice than in control mice, and Gui Zhi decoction at high and low dosages could decrease the CD4 and CD8 cells. Also, Gui Zhi decoction at high dosage could decrease the IL-6 and TNF-alpha concentration in serum. CONCLUSION: Gui Zhi decoction can lower the arthritic scores and decrease the incidence of CIA in mice, and the mechanism is in part regulating enteric mucosal immune.

Animals↗

PubMed2005

The effect of triptolide on CD4+ and CD8+ cells in Peyer's patch of SD rats with collagen induced arthritis.

Triptolide is a purified component from a traditional Chinese herb Tripterygium wilfordii Hook F. It has been shown to have anti-inflammatory and immunosuppressive activities by its inhibitory effect on T cells. But the effect of triptolide on Peyer's patch cells is unknown. Enteric mucosal immune system, including Peyer's patch, is regarded as one of the sites for inducing immunity tolerance, and this intolerance effect has been used to induce oral tolerance which can considerably reduce arthritis severity in several models of experimental polyarthritis and RA patients. In this study, we investigated the effect of triptolide on the Peyer's patch cells and peripheral lymphocytes in collagen induced arthritis (CIA) in rats. CIA in rat is a widely studied animal model of inflammatory polyarthritis with similarities to rheumatoid arthritis (RA). Our data show that triptolide could lower the arthritic scores and delay the onset of CIA. There are more Peyer's patches in triptolide treated rats than in control rats, while there is no difference in Peyer's patch numbers between CIA rats and triptolide treated rats. In the Peyer's patch, more CD4+ cells are observed in CIA rats, and the numbers of CD4+ cells in triptolide treated rats and control rats are similar. While more CD8+ cells are observed in triptolide treated rats, and the numbers of CD8+ cells in CIA rats and control rats are similar. In periphery, more CD4+ cells and less CD4+ cells in CIA rats and triptolide treated rats are respectively observed. Therefore, the regulation on Peyer's patch might explain some of the immunosuppressive activities of triptolide, and enteric immune response might be actively involved in CIA pathogenesis. It is suggested that the Peyer's patch is one of the primary targets of the immunosuppressive activity of triptolide.

Animals↗

PubMed2005

Elucidation of the small RNA component of the transcriptome.

Small RNAs play important regulatory roles in most eukaryotes, but only a small proportion of these molecules have been identified. We sequenced more than two million small RNAs from seedlings and the inflorescence of the model plant Arabidopsis thaliana. Known and new microRNAs (miRNAs) were among the most abundant of the nonredundant set of more than 75,000 sequences, whereas more than half represented lower abundance small interfering RNAs (siRNAs) that match repetitive sequences, intergenic regions, and genes. Individual or clusters of highly regulated small RNAs were readily observed. Targets of antisense RNA or miRNA did not appear to be preferentially associated with siRNAs. Many genomic regions previously considered featureless were found to be sites of numerous small RNAs.

Arabidopsis↗