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Biomedical subjects

Yong Jiang

Publications and source records attributed to Yong Jiang.

At least 127 records · Page 7Linked to original sources
PubMed2003

Sequence and expression of a cDNA encoding both pituitary adenylate cyclase activating polypeptide and growth hormone-releasing hormone in grouper (Epinephelus coioides).

Both pituitary adenylate cyclase activating polypeptide PACAP and growth hormone-releasing hormone GHRH belong to the vasoactive intestinal polypeptide- glucagon-secretin family. They are encoded on the same gene in vertebrates (birds, amphibian, fish). Although the gene encoding PACAP and GHRH has been cloned in other fish species, characterization of this gene in the commercially important grouper (Epinephelus coioides) has not been previously reported. In this study, the GHRH/PACAP cDNA was cloned from grouper hypothalamic tissue. Two cDNA variants of the GHRH/PACAP precursor gene were identified as a result of alternative splicing, a long form encoding both PACAP and GHRH and a short form encoding only PACAP. Both the long and the short forms of the GHRH/PACAP precursor cDNA were identified in grouper 22 issues as well as expression in embryos and larvae by semi-quantitative RT-PCR detection. PACAP / GHRH precursor mRNA was expressed at a high level in the central nervous system than in several peripheral tissues. The data presented here provide the report of PACAP/GHRH mRNA expression in eye and gill tissues in fish. PACAP/GHRH mRNA was expressed in grouper embryo and all larval stages examined and was expressed at a high level starting on neurula stage onwards. The result suggests that PACAP/GHRH had an important role in the development of embryos and larvae, especially in neurula appearance stage.

Alternative Splicing↗
PubMed2003

[Preliminary result on the nosocomial infection of severe acute respiratory syndrome in one hospital of Beijing].

OBJECTIVE: To study the transmission route of severe acute respiratory syndrome (SARS) nosocomial infection. METHODS: Ten identified SARS patients were selected from a general hospital in March. Survey was carried out through a standardized questionnaire provided by Chinese Center for Disease Control and Prevention. Contents of the questionnaire would include: history of contact with SARS patient, route of infection, methods used for protection and so on. RESULTS: (1) Distribution os SARS patients were confined to 3 wards: 4, 5, and 6 on the 7, 8, 12, 13 and 14 floors in the west unit of the inpatient building. Most of the inpatients were elderly and having severe original diseases. (2) Index patients were the first generation source of transmission and they infected inpatients and medical staff, making them the second generation. People with latent infection who had close contact with SARS patients might also serve as the possible source of transmission. (3) The major transmission routes were: near distant droplet infection and close contact infection. There was also a clue to the probability of aerosol or droplet nuclei infection through air-conditioning and ventilation system. CONCLUSION: Nosocomial infection appeared to be the main characteristic of the SARS epidemic in the early stage of this hospital. Other than close contact and near space airborne transmission of SARS virus, the possibility of long-distance aerosol transmission called for further epidemiological and experimental studies in the future.

Adult↗
PubMed2003

[Screening and identification of proteins interacting with p38 MAP kinase via T7 phage-display screening system].

OBJECTIVE: To screen and identify proteins that interact with p38 mitogen-activated protein (MAP) kinases by means of T7 phage-display screening system. METHOD: His-tagged fusion protein of p38 MAP kinase was used to coat a 96-well ELISA plate and Ni-NTA resin, which served as the media for screening human lung and liver T7 phage cDNA libraries. RESULTS: After 4 rounds of biopanning, 86 independent plaques were selected and processed by EDTA. The inserted gene fragments from these plaques were amplified by PCR, the products purified by a gel recovery method. The sequences of the insertions were identified and analyzed with BLAST program in GenBank. Forty-six clones were found to encode proteins. CONCLUSION: T7 phage-display screening system is convenient, rapid and effective for screening the P38 MAP kinase-binding proteins.

Bacteriophage T7↗
PubMed2003

[A study on the epidemiology of permanent tooth carles in children aged 15 years in Anhui province].

OBJECTIVE: The first study on the epidemiology of oral health status in AnHui province was held. The purpose of this survey was to investigate the prevalence of dental diseases and the needs of dental treatment, so as to develop effective programs in providing dental care in children. METHODS: Non-proportional stratified cluster sampling was used for this study. RESULTS: The results showed that XDMFT in this group was 0.95, permanent caries prevalence rate was 39.78%, lower than that of the same age children in other 11 provinces in Mainland(P < 0.001). The proportion of DMFT was 86.78%(D), 4.30% (M), 8.92% (F), respectively. The caries number that needed dental care were 1842 teeth(0.78 teeth per person). CONCLUSION: The caries prevalence rate, the XDMF and the "F" were lower than the same age children in 11 provinces in Mainland and the "M" was higher.

Adolescent↗
PubMed2003

[Vector construction for the intracellular domain of human receptor for advanced glycation end- products and expression of the fusion protein].

OBJECTIVE: To construct a eukaryotic expression vector for GST-tagged intracellular domain of human receptor for advanced glycation end-products (hRAGE), and to study the function of the expressed fusion protein and identify its interacting proteins. METHODS: The coding sequence of the intracellular fragment of hRAGE was amplified by PCR and inserted into pGEX-KG vector, a general GST fusion protein expression vector. After PCR identification, endonuclease digestion and DNA sequencing, the recombinant was transformed into E.coli BL21 to achieve the expression of GST fusion protein induced by isopropyl-beta-D-thiogalactoside (IPTG), followed by purification of the protein on glutathione-superflow resin. RESULTS: The recombinant of GST/hRAGE-C was constructed and identified by PCR, endonucleases digestion and DNA sequencing. After protein expression was achieved in E. coli, a molecular mass of 35 kD GST fusion protein was purified, whose molecular mass and purity were assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). CONCLUSION: The expression vector for intracellular domain of hRAGE has been successfully constructed and efficient expression of the fusion protein is obtained, which can be of value for further studies.

Genetic Vectors↗
PubMed2003

[Relationships between periapical lesion and IL-1, TNF-alpha gene expression in rat].

OBJECTIVE: To understand the effects of the IL-1, TNF-alpha cytokines on the pathogenesis of periapical lesions by investigating its gene expression in rat. METHODS: The model was established by surgically exposing mandibular molar teeth and left open to permit infection from the oral environment. The SD rats were killed at 1, 2, 3, 4 weeks and mandibular molar teeth X-ray were taken. In situ hybridization was used to test IL-1alpha, IL-1beta, TNF-alpha mRNA expression in periapical area and the kinds of positive cells were identified. Using image analysis system analyzed gene expression semi-quantified. RESULTS: IL-1alpha, IL-1beta and TNF-alpha mRNA were all expressed beginning at 1 week, peaked at 3 weeks, and declined somewhat at 4 weeks, but IL-1beta mRNA was expressed at much lower levels with the same kinetics (P<0.01). Most of the staining occurred in areas that had heavy inflammatory infiltrate, fibroblasts, or endothelial cells. There was a statistically significant correlations between the area of periapical lesion and the number of positively stained cells for IL-1alpha and for TNF-alpha (IL-1alpha: r=0.875, P<0.001; TNF-alpha: r=0.858, P<0.001), and between the number of positive cells for IL-1alpha and that of for TNF-alpha (r=0.969, P<0.001). CONCLUSIONS: IL-1alpha and TNF-alpha genes are highly expressed in developing periapical lesions in rat, which supports the hypothesis that these two cytokines play a key role in pulpal and periapical pathogenesis, including the concomitant bone destruction.

Animals↗
PubMed2003

[Effects of tobacco on proliferation and attachment of human periodontal ligament fibroblast].

OBJECTIVE: To evaluate the effects of nicotine and tobacco extract (ST) on PDLFs morphology, structure, proliferation and attachment. METHODS: PDLFs were cultured in the presence of nicotine and ST at various concentration. The cell changes in the morphology and structure were examined by histological and transmission electrical microscope (TEM). The growth and attachment of cell were measured by MTT method. RESULTS: The size of the cells became smaller gradually and their shapes changed from shuttle type to oval or round when the concentration of nicotine and ST increased, the polarity of the cells was in disorder, ultrastructure showed that the organelles, especially rough-surfaced endoplasmic reticulum and golgi complex decreased in number, microtubule and microfilaments were disassembled, the nuclei became fewer or shrunk, the growth and attachment were dose-dependently inhibited. CONCLUSIONS: Nicotine and ST can change PDLFs' morphology and structure, they may inhibit the growth and attachment through disruption of the cytoskeleton, suggesting nicotine and ST may have pathological role on human periodontitis.

Cell Adhesion↗
PubMed2003

[Spatial variability of soil nutrients in cultivated surface soil of Sujiatun District, Shenyang City].

The spatial variability of organic matter (OM), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) in 0-20 cm horizon in cultivated soils of Sujiatun District, Shenyang City were investigated using geostatistics and geographic information system (GIS). Data of each variable fitted normal distribution or normal distribution after log transformation, and a spherical model for semivariogram fitted all the variables. Semivariograms indicated that OM content strongly spatially dependent with the ratio of nugget to sill of 24.11%. The contents of AN, AP and AK were moderately spatially dependent with the ratio of nugget to sill of 29.53%, 60.77% and 58.82%, respectively. The ranges of spatially dependent for OM, AN, AP and AK were 26.051, 28.293, 15.132 and 23.813 km, respectively. The spatial variability for OM and AN was fundamentally affected by structural factors such as soil formation factors, and that for AP and AK was by random factors such as fertilization. Kriging maps showed the spatial distributions of the four variables, which were useful in monitoring nutrient changes and providing quantitative support to decision and policy making for agriculture and environment management.

Geographic Information Systems↗
PubMed2002

[Regulation of lipopolysaccharide-induced inducible nitric oxide synthase gene expression by protein kinase C].

OBJECTIVE: To explore the molecular mechanism of inducible nitric oxide synthase (iNOS) gene expression induced by lipopolysaccharide (LPS) in monocytes or macrophages. METHODS: Luciferase report gene vector pGL2iNOSLuc driven by murine iNOS promoter region was constructed using gene recombination technique. RAW264.7 cells were cultured and transfected with luciferase report gene vector pGL2iNOSLuc. Twenty four hours later, PKC inhibitor H-7, calcium channel blocker verapamil, was added into the culture. LPS or PKC activator PMA was added 2 hours later to stimulate the cells. The activity of beta-galactosidase and luciferase was examined and the relative luciferase activity, representing the iNOS transactivity, was calculated. Modified Griess method was used to measure the concentration of NO(2)(-)/NO(3)(-) in the culture so as to evaluate the effect of PKC inhibitor on NO production induced by LPS. RT-PCR was used to study the effect of LPS on iNOS gene expression in RAW264.7 cells. RESULTS: Thirty minutes after stimulation of RAW264.7 cells by LPS, the activity of PKC in cytomembrane increased and the activity of PKC in cytoplasm decreased significantly in comparison with the baseline levels (P < 0.01). The NO concentration was 30.1 micro mol/L +/- 5.4 micro mol/L 12 hours after the stimulation of LPS on RAW264.7 cells, and was much more higher 24 and 48 hours after, all significantly higher than before (all P < 0.01). The NO concentration in the supernatant with H-7 at any time point was significantly lower than those in corresponding samples without H-7 (all P < 0.01). After stimulation of LPS and PMA, the relative luciferase activity was 25.3 +/- 4.6, significantly higher than the baseline level (P < 0.01). H-7 and verapamil significantly inhibited the LPS-induced iNOS transactivity (both P < 0.01). iNOS mRNA expression was increased greatly, and H-7 significantly inhibited this expression 12, 24, and 48 hours after LPS stimulation. CONCLUSION: In RAW264.7 cells, LPS stimulation increases intracellular calcium and activates PKC, thus inducing iNOS gene expression that contributes to the production of NO, which is an important signaling mechanism of NO production in septic shock.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2002

[Synergetic effect of mitogen-activated protein kinase pathway on expression of tumor necrosis factor alpha gene in RAW 264.7 cells induced by lipopolysaccharide].

OBJECTIVE: To explore the molecular mechanism of the synergetic effect of mitogen-activated protein kinase (MAPK) pathway on expression of tumor necrosis factor alpha (TFG-alpha) gene in murine monocyte (RAW264.7 cells) induced by lipopolysaccharide (LPS). METHODS: RAW264.7 cells were cultured, transfected with vectors with mutants of different constitutively active MAPK kinases, i. e., ERK, JNK, and p38, vectors with inactivated mutants of MAPK kinase, and murine TNF-alpha driven report gene pGL2TNFLuc, and then stimulated by LPS. Protein kinase assay was used to analyze the activity of MAPKs. Western blotting was used to detect the amount of target proteins. RT-PCR was used to detect the influence of the MEK/REK inhibitor PD98059, JNK inhibitor SP600125, and p38 inhibitor SB203580 on the expression of TNF-alpha gene induced by LPS. RESULTS: ERK1, JNK1, and p38 MAPKs were transiently activated by LPS. After the vectors with activated MAPK mutants were co-transfected with murine TNF-alpha driven report gene pGL2TNFLuc into RAW264.7 cells, the transcription activity of TNF-alpha promoter was induced to different degrees. After the vectors with inactivated MAPK mutants were co-transfected with murine TNF-alpha driven report gene pGL2TNFLuc into RAW264.7 cells, the transcription activity of TNF-alpha promoter was inhibited. CONCLUSION: The transactivity of TNF-alpha promoter stimulated by LPS involves ERK, JNK, and p38 pathways. These three major MAPK pathways exert synergetic effects on the gene regulation of TNF-alpha expression.

Animals↗
PubMed2002

[Construction and expression of red fluorescent protein reporter gene vector containing human eNOS promoter].

OBJECTIVE: To construct the red fluorescent protein reporter gene vector containing human eNOS promoter sequence to study the mechanism of regulating the expression of eNOS gene by vessel wall shear stress. METHODS: The genomic DNA of endothelial cells from fetal umbilical vein was drawn. The gene sequence of eNOS promoter gene therein was cloned by PCR technique and constructed into the red fluorescent protein vector, pDsRed-1. The recombinant vector, pDseNOSRed was then transfected into 293 cells, human fetal renal epithelial cells. Blank vector, pDsRed-1, was transfected into 293 cells as controls. The expression and distribution of the reporter gene were observed by fluorescent microscopy. RESULTS: PCR and double restriction enzyme digestion showed that the recombinant vector, pDseNOSRed, was constructed correctly. This vector was highly expressed in the 293 cells. Expression of red fluorescence, evenly distributed in whole cells, occurred since 12 hours after transfection, reached the peak concentration 3648 h after transfection, and dissappeared almost completely 120 h after. No red fluorescence was observed in the control cells. CONCLUSION: A red fluorescent protein reporter gene vector containing human eNOS promoter sequence and expressed highly in mammalian cells has been constructed successfully, thus providing an important and convenient tool to study the mechanism mechanism of regulating the expression of eNOS gene by vessel wall shear stress.

Cell Line↗
PubMed2002

Regulation of matrix metalloproteinase-9 (MMP-9) by translational efficiency in murine prostate carcinoma cells.

Expression of increased levels of matrix metalloproteinase-9 (MMP-9) has been implicated in tumor progression and angiogenesis. Much of our knowledge of the controls of MMP-9 levels has focused on transcription. Here we show that MMP-9 levels are also controlled by translational efficiency in murine prostate carcinoma cells. The murine prostate carcinoma cells 148-1,LMD and 148-1,PA were derived from a single mouse that had been implanted with urogenital sinus transformed by ras and myc. 148-1,PA secretes little MMP-9 yet has equivalent amounts of MMP-9 mRNA as the cell line 148-1,LMD that secretes substantially more. Infection with a retroviral vector for murine MMP-9 led to more expression of MMP-9 in both cases, but the differential remained. Human MMP-9 is equally expressed in both cells after infection with a vector for human MMP-9 indicating that the effect is species-specific. Pulse chase analysis revealed that MMP-9 was synthesized more rapidly in the 148-1,LMD cells than in the 148-1,PA cells. Markedly more MMP-9 mRNA was associated with polysomes in the cell line synthesizing more MMP-9. These results indicate regulation of MMP-9 synthesis at the level of translational efficiency.

Animals↗
PubMed2002

[Expression of intercellular adhesion molecule-1 in different organs of the mice with endotoxic shock induced by lipopolysaccharide].

To investigate and compare the expression of intercellular adhesion molecule-1 (ICAM-1) in different organs of the mice with endotoxic shock induced by lipopolysaccharide (LPS), protein and mRNA of ICAM-1 were measured by Western blotting and RT-PCR respectively in different organs of BALB/c mice administered intraperitoneally with 5 mg/kg LPS. The results showed that the constitutive expression of ICAM-1 protein and mRNA was the greatest in the lungs, followed by the spleen, kidney and intestine. After LPS stimulation, the upregulation of ICAM-1 was still greatest in the lungs, followed by the liver, spleen, heart, kidney and intestine. Compared with the normal mice, the expression of ICAM-1 protein in endotoxic shocked mice increased by 4.5-fold in the lungs, 3.0-fold in the kidney, 1.5-fold in the spleen; the expression in the liver and heart was negative under normal condition and changed into positive during endotoxic shock; but ICAM-1 expression in the intestine did not change significantly. The expression of ICAM-1 mRNA also increased consistently. These data highlight that LPS can up-regulate ICAM-1 protein and mRNA expression in different tissues of the mice with endotoxic shock. The difference in ICAM-1 expression among the organs may lead to different sensitivity of organ damage in endotoxic shock. This suggests that inhibition of ICAM-1 expression may be a useful principle for prevention and treatment of endotoxic shock.

Animals↗
PubMed2002

Induced responses in clover to an herbaceous mite.

Halotydeus destructor feeding on subterranean clover cotyledons can cause severe damage. The mites live on the soil surface and move up onto plants to feed. Foraging behaviour consists of palpating, probing, and feeding with frequent transitions between them. Sustained feeding is made up of a series of short (1-2 min) feeds separated by periods of palpating. The mites tend to feed in aggregations, and are attracted to cotyledons damaged by other mites feeding or by mechanical damage. Mites can distinguish between resistant and susceptible cotyledons within 30 min and resistance is antixenotic due to deterrence. Study of the mechanisms shows this to be induced plant resistance. Several green leaf volatiles are involved in the plant/mite interaction. After feeding commences, 2-E-hexenal is released that at low concentrations is attractive to mites, perhaps causing the feeding aggregations. The wound-induced C(8) compound, 1-octen-3-one, plays a significant role in the deterrence of cotyledons of resistant subterranean clover varieties to H. destructor. Damaged cotyledons of resistant varieties produce more 1-octen-3-one that those of susceptible varieties. Screening for resistance has identified varieties from Italy showing resistance. H. destructor does not occur in Europe. Production of damage-induced volatiles by the resistant plants may have resulted from invasion by herbivores or pathogens, but not from coevolution with these mites. The responses of H. destructor are probably an adaptation to these general plant defensive compounds.

Aldehydes↗
PubMed2002

Semiochemicals from ovaries of gravid females attract ovipositing female houseflies, Musca domestica.

Chemical signals originating from the ovaries of gravid females of Musca domestica (Diptera: Cyclorrhapha: Muscidae) attract ovipositing females to common egg-laying sites. Behavioral experiments indicated that females preferred to oviposit in fermented wheat bran containing ovaries from reproductively mature houseflies. Females preferred to oviposit in fermented wheat bran than wet wheat bran. This effect was additive with the attraction to housefly ovaries. Solvent extracts from housefly ovaries were attractive to gravid females. Extracts obtained with hexane were most attractive to gravid females for egg laying, and extracts obtained with ethyl acetate attracted more egg laying than extracts obtained by dichloromethane. Gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) analysis showed that tricosane and (Z)-9-tricosene were the main components of the hexane extracts. Both tricosane and (Z)-9-tricosene were shown to elicit dose-dependent aggregation of gravid females in oviposition bioassays, but high doses of either chemical were not attractive.

Journal Article↗
PubMed2002

Xanthone O-glycosides from Polygala tenuifolia.

Four xanthone O-glycosides, polygalaxanthones IV-VII were isolated from the roots of Polygala tenuifolia Willd., together with eight known compounds. The structures of the four xanthone O-glycosides were established as 6-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl]-1-hydroxy-3,7-dimethoxyxanthone (polygalaxanthone IV), 6-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl]-1,3-dihydroxy-7-methoxyxanthone (polygalaxanthone V), 6-O-(beta-D-glucopyranosyl)-1,2,3,7-tetramethoxyxanthone (polygalaxanthone VI), and 3-O-[alpha-D-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl]-1,6-dihydroxy-2,7-dimethoxyxanthone (polygalaxanthone VII), respectively, on the basis of analysis of spectroscopic evidence.

Glycosides↗
PubMed2002

ParE toxin encoded by the broad-host-range plasmid RK2 is an inhibitor of Escherichia coli gyrase.

Broad-host-range plasmid RK2 encodes a post-segregational killing system, parDE, which contributes to the stable maintenance of this plasmid in Escherichia coli and many distantly related bacteria. The ParE protein is a toxin that inhibits cell growth, causes cell filamentation and eventually cell death. The ParD protein is a specific ParE antitoxin. In this work, the in vitro activities of these two proteins were examined. The ParE protein was found to inhibit DNA synthesis using an E. coli oriC supercoiled template and a replication-proficient E. coli extract. Moreover, ParE inhibited the early stages of both chromosomal and plasmid DNA replication, as measured by the DnaB helicase- and gyrase-dependent formation of FI*, a highly unwound form of supercoiled DNA. The presence of ParD prevented these inhibitory activities of ParE. We also observed that the addition of ParE to supercoiled DNA plus gyrase alone resulted in the formation of a cleavable gyrase-DNA complex that was converted to a linear DNA form upon addition of sodium dodecyl sulphate (SDS). Adding ParD before or after the addition of ParE prevented the formation of this cleavable complex. These results demonstrate that the target of ParE toxin activity in vitro is E. coli gyrase.

Adenosine Triphosphate↗