Biomedical subjects

Miao Wang

Publications and source records attributed to Miao Wang.

35 records · Page 2Linked to original sources

PubMed2004

[Expression of t(11;18) and bcl-10 in gastrointestinal MALT lymphoma].

To detect chromosome translocation t(11;18) (q21;q21) and the nuclear expression of bcl-10 in gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphoma in Chinese, a possible API2-MALT fusion transcript specific to t(11; 18) (q21; q21) in tumors from 42 cases of primary gastrointestinal lymphoma (29 cases of low grade MALT lymphoma, 13 cases of transformed MALT lymphoma) and 40 cases of diffuse large B cell lymphoma was examined by means of RT-PCR and proved by DNA-sequencing. Bcl-10 expression was examined by immunohistochemical method. The results showed that t(11;18) (q21;q21) was 14% positive in cases of low grade MALT lymphomas and 46% positive in transformed MALT lymphomas, but none in cases of DLBCL. Bcl-10 nuclear expression was seen 61% in low grade MALT and 69% in transformed MALT lymphoma. It was suggested that t(11;18) (q21;q21) was related to the prognosis and development of highly advanced MALT lymphoma but not relevant to DLBCL. Bcl-10 nuclear expressions were not significantly different between these two groups, which remains to be explained.

Adaptor Proteins, Signal Transducing↗

PubMed2004

[Effects of soil water regimes on the growth of Quercus mongolica seedlings in Changbai Mountains].

This paper studied the response of the seedlings of Quercus mongolica, one of the dominant tree species in Changbai Mountains, to the artificially controlled three soil water gradients, including their morphology, biomass and photosynthetic characteristics. The results indicated that various water regimes significantly affected the biomass and its distribution pattern in the leaves, branches and roots, as well as the leaf gas exchange. Under soil water stress, the crown structure changed, and the tree height, groundline diameter, single leaf area, and aboveground and belowground biomass were inhibited. As soil water content decreased, the ratio of belowground and aboveground biomass dry weight significantly increased. Water stress had a negative effect on net photosynthetic rate, CO2 use efficiency and carbon use efficiency. The responses of stomatal conductance, transpiration rate and water use efficiency to water stress were complicated. Only at low soil water content, the stomatal conductance and transpiration rate significantly decreased, while water use efficiency increased. It was demonstrated that Quercus mongolica was the tree species with variable resistance to drought, and the resistance could be improved by long-term soil water stress.

Biomass↗

PubMed2004

[Nitric oxide, a signaling component of ABA-induced stomatal closure].

The present study provided the evidence that exogenous NO and ABA regulated the stomatal movement in poplar leaves. It showed that different levels of SNP and ABA induced the stomatal closure in detached leaves. NO enhanced stomatal closure that induced by ABA. The effect of NO and ABA on stomatal closure was suppressed by c-PTIO, a specific NO scavenger. It was confirmed that NO involved in ABA-mediated stomatal movement. The activities of POD were dramatically inhibited, but those of SOD hardly decreased in different levels of SNP and ABA treatment. However, in vitro experiments indicated that the activities of POD were dramatically inhibited by NO, but not ABA. The results demonstrated that NO mediated ABA-induced stomatal closure of trees, and was a signaling component of ABA-induced stomatal closure.

Abscisic Acid↗

PubMed2004

[Soil N2O and CH4 fluxes in broad-leaved Korean pine forest of Changbai Mountains].

The soil N2O and CH4 fluxes in the broad-leaved Korean pine forest of Changbai Mountains under two treatments were measured by static chamber-gas chromatograph. The results showed that litter significantly influenced N2O emission and CH4 uptake, and the effect efficiency was 36.9% and 23.4%, respectively. The N2O emission fluxes of the two treatments showed similar seasonal variations, with the highest in spring, higher in summer, and lower in autumn and winter. Furthermore, their diurnal variations were the same, the maxima both occurred at 18 o'clock, and the minima appeared at 12 o'clock and 14 o'clock. As for CH4 uptake fluxes, their seasonal variations were similar. The CH4 uptake fluxes were significantly higher in summer and autumn than in spring and autumn, and their diurnal variations were also the same, both went up from 14 o'clock to 18 o'clock and then started to go down until 6 o'clock. The results also indicated that soil N2O emission fluxes were negatively linear-correlated to CH4 uptake fluxes in the broad-leaved Korean pine forest.

China↗

PubMed2004

[Expression of BCL-10 in gastrointestinal mucosa-associated lymphoid tissue lymphoma].

OBJECTIVE: To explore the significance of BCL-10 protein expression in the gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphoma. METHODS: Immunohistochemistry studies were performed using CD20, CD79a, CD3, CD45RO, CD23, CD5, CD10 monoclonal antibodies in 43 cases of gastrointestinal MALT lymphomas, including 25 indolent classical MALT lymphomas and 18 MALT lymphomas with large cell transformation. BCL-10 protein expression was assayed in the tumor cells. RESULTS: In 25 low-grade MALT lymphomas, expression of BCL-10 was found in the nuclei in 10 cases, in both nuclei and cytoplasm 1 case, in cytoplasm 3 cases and no expression 11 cases. In 18 transformed MALT lymphomas, BCL-10 was expressed in the nuclei in 7 cases, in both nuclei and cytoplasm 1 case, in cytoplasm 2 cases, no expression 8 cases. The frequency of BCL-10 expression in nuclei was the highest (44.2%). CONCLUSION: The frequency of BCL-10 expression in nuclei in the gastrointestinal MALT lymphoma is high, indicating that it may associate with the pathogenesis of this entity, and may be helpful to its diagnosis.

Adaptor Proteins, Signal Transducing↗

PubMed2003

Increased insulin sensitivity and hypoinsulinemia in APS knockout mice.

A tyrosine kinase adaptor protein containing pleckstrin homology and SH2 domains (APS) is rapidly and strongly tyrosine phosphorylated by insulin receptor kinase upon insulin stimulation. The function of APS in insulin signaling has heretofore remained unknown. APS-deficient (APS(-/-)) mice were used to investigate its function in vivo. The blood glucose-lowering effect of insulin, as assessed by the intraperitoneal insulin tolerance test, was increased in APS(-/-) mice. Plasma insulin levels during fasting and in the intraperitoneal glucose tolerance test were lower in APS(-/-) mice. APS(-/-) mice showed an increase in the whole-body glucose infusion rate as assessed by the hyperinsulinemic-euglycemic clamp test. These findings indicated that APS(-/-) mice exhibited increased sensitivity to insulin. However, overexpression of wild-type or dominant-negative APS in 3T3L1 adipocytes did not affect insulin receptor numbers, phosphorylations of insulin receptor, insulin receptor substrate-1, or Akt and mitogen-activated protein kinase. The glucose uptake and GLUT4 translocation were not affected by insulin stimulation in these cells. Nevertheless, the insulin-stimulated glucose transport in isolated adipocytes of APS(-/-) mice was increased over that of APS(+/+) mice. APS(-/-) mice also showed increased serum levels of leptin and adiponectin, which might explain the increased insulin sensitivity of adipocytes.

3T3 Cells↗

PubMed2003

Expression of human papillomavirus type 6 L1 and L2 isolated in China and self assembly of virus-like particles by the products.

To study variations of genome late region of human papillomavirus type 6 (HPV-6) isolated in China and assembling capabilities of the encoded capsid proteins, HPV-6 L1 and L2 sequences were cloned and used for expression in Bac-to-Bac baculovirus expression systems (Gibco BRL). Based upon L1 and L2 overlapping sequence two sequences (GenBank accession number AY015006, AY015008) of HPV-6 late region (2869 bp long) were assembled and classified into HPV-6b by phylogenetic analysis. Compared with prototype sequence, nine point mutations were found, including four missense mutations. L1, instead of L2, could self-assemble into virus-like particles (VLPs) in Sf9 nucleus. VLPs self-assembled by L1 alone (L1-VLPs) and by L1 plus L2 (L1+L2-VLPs) were purified and further characterized. Both types of VLPs were spherical particles with a diameter of approximately 50 nm. L1+L2 VLPs comprising L1 and L2 in the molar ratio of about 4:1 possessed the HPV-6 L1 VLP surface and conformational epitopes. In co-expression assay with a series of MOI combination of L1 and L2 recombinant baculoviruses (total MOI=10), existence of L2 of certain level enhanced L1 production by 0.8 fold and VLP production by 3 - 4 folds under experimental conditions. In conclusion, variation rate of HPV-6 genome late region is less than 0.28% and the substitutions A to G at position 7081 and G to A at 7099 may represent region characteristics. The cloned HPV-6 L1 and L2 sequences can be expressed efficiently in Sf9 cells, and the expressed products (L1 or L1+L2) can self-assemble into VLPs that resemble naturally occurring virions.

Animals↗

PubMed2003

[Effects of soil temperature and moisture on soil respiration in different forest types in Changbai Mountain].

The effects of soil temperature (0, 5, 15, 25, 35 degrees C) and water content on soil respiration in three forest types in Changbai Mountain were evaluated in laboratory condition. The results indicated that the soil respiration rate was positively correlated to soil temperature from 0 to 35 degrees C and it increased with soil water content from 0.21 to 0.37 kg.kg-1. The soil respiration rate decreased with soil water content when water content was over the range. The result suggested the interactive effects of temperature and water content on soil respiration. There were significant differences in soil respiration among the various forest types and the highest was in broad leaf Korean pine forest, then in erman's birch forest, and it was the lowest in dark coniferous forest. The optimal condition for soil respiration in broad-leaved Korean pine forest was at 35 degrees C under 0.37 kg.kg-1 water content, and it was at 25 degrees C under 0.21 kg.kg-1 in dark coniferous forest and at 35 degrees C under 0.37 kg.kg-1 water content in erman's birch forest. Because the forests of broad leaf Korean pine, dark coniferous and erman's birch are located at various altitudes, the soil temperatures had 4-5 degrees C variation in different forest types during the same period. The soil respiration rates measured in brown pine mountain soil were lower than those in dark brown forest and they were higher in mountain grass forest soil than those in brown pine mountain soil.

Carbon Dioxide↗

PubMed2003

[Soluble expression of peptide containing MUC1/Y-specific epitope in Escherichia coli and preparation of the antibody].

MUC1 mucin is a high molecular weight, type I transmembrane glycoprotein. High and aberrant expression of MUC1 is observed in various types of tumors, which make it an ideal target for tumor biotherapy as well as a biomarker for tumor diagnosis and prognosis. MUC1/Y is an isoform of MUC1 generated by alternative splicing. Specific expression of MUC1/Y in breast cancer as well as its involvement in tumor cell signal transduction have been reported. In order to purify peptides containing MUC1/Y-specific epitope in E. coli and prepare MUC1/Y-specific antibody, DNA fragment encoding the MUC1/Y-specific peptide was amplified by PCR using MUC1/Y full length cDNA as the template and cloned into fusion expression vector pGEX-2T, resulting pGEX-Y30. DNA sequencing was performed to confirm the correct amplification and orientation of the target sequence. Competent E. coli DH5alpha was transformed with pGEX-Y30 and the expression was induced for 4-5 hours in 0.2 mmol/L IPTG at 30 degrees C and 37 degrees C. Expressed proteins were released from the cells by ultrasonication or B-PER II reagent treatments. The fusion protein GST-Y30 were purified by affinity and anion exchange columns and identified by SDS-PAGE and Western-blotting. Polyclonal antibody was prepared by immunizing rabbits with the GST-Y30 protein for 4 times with intervals of 3 weeks and purified by GST column. Western blotting, ELISA and immunohistochemistry analysis were carried out using the purified antibody to confirm its MUC1/Y-binding capacity and specificity. The expressed fusion protein GST-Y30 is about 31 kD in size and represented about 20% of total cellular proteins. The majority of the GST-Y30 protein existed as soluble form when the induction was carried out at both 30 degrees C and 37 degrees C. After the two-step purification, the purity of GST-Y30 was about 94%. The titer of polyserum generated by GST-Y30 immunization was 1:320,000 by ELISA. The antiserum showed MUC1/Y specificity and can recognize MUC1/Y on MCF7 cell. The MUC1/Y-specific polyclonal antibody can be used for studying the role of MUC1/Y in carcinogenesis.

Animals↗

PubMed2002

Purification, crystallization and preliminary X-ray diffraction analysis of a novel mannose-binding lectin from Gastrodia elata with antifungal properties.

A plant antifungal protein, Gastrodia antifungal protein (GAFP-1) has been isolated from terminal corms of the orchid Gastrodia elata B1 f. elata, purified to homogeneity and crystallized by means of the hanging-drop vapour-diffusion method. The best quality crystals grew over several months at 277 K. The crystal used for data collection belongs to the space group P2(1)2(1)2, with unit-cell parameters a = 61.087, b = 91.488, c = 81.132 A. Using a synchrotron-radiation source, the resolution limit of the data reached 2.0 A, with an overall R(merge) of 0.097 and a completeness of 99.8%. Four independent molecules were estimated to be present in the asymmetric unit, with a solvent content of 46.3%. This data will help to solve the first structure of a monomeric monocot mannose-binding lectin.

Amino Acid Sequence↗

PubMed2002

Design and implementation of a gain scheduling controller for a water level control system.

The design of a gain-scheduled proportional plus integral (PI) controller for a nonlinear water-tank level control system is presented. A novel approach of determining operating points in terms of interpolation error is also given. The controller is implemented in LABVIEW in the laboratory. The field test results of the system response at different operating conditions clearly illustrate the controller's improved performance over a fixed PI controller.

Computer Simulation↗

PubMed2002

Purification, crystallization and initial structural solution of a new alpha-like toxin with cardiac toxicity from scorpion Buthus martensii Karsch.

An alpha-like toxin named BmK M7 active on both mammals and insects has been purified from the venom of scorpion Buthus martensii Karsch (BmK) recently. The electrophysiological experiments showed that M7 can bind to human cardiac Na+-channel and modify its normal properties, hence can be considered as a cardiotoxin. Single crystals of M7 have been obtained by hanging-drop vapor diffusion method using ammonium sulfate as precipitant in Tris-HCl buffer at pH 8.5. A data set to 1.40 A resolution was collected using synchrotron radiation and CCD detector in Photon Factory in Japan. Data analysis showed that the crystals belonged to space group P3(1)21/P3(1)21, with cell dimensions a=b=32.76 A, c=176.82 A. Assuming two molecules per asymmetric unit, the Vm value is 1.92 A3/Da. The initial structural analysis was carried out by molecular replacement, which showed the correct space group (P3(1)21), and the orientations and positions of the two molecules in the asymmetric unit.

Animals↗

PubMed2002

[CCA of water beetles' distribution and environmental factors in lentic samples of north Changbai Mountain].

The relationship between 28 species water beetles in 12 lentic samples and environmental factors of North Chang-bai Mountain was studied by Cononical Correspondence Analysis (CCA). The results showed that degree of underwater humus and altitude are the major factors correlated with beetles distribution, and the correlation coefficients of environmental factors and axes of CCA were 0.8371 and 0.7206 respectively, while water temperature and plant density also had certain effects. Under the influence of environmental factors, the water beetles' populations were different in different habitat. Coelambus impressopunctatus, Colymbetes magnus, Helophorus browni, Haliplus spp. distributed in deep water pool. Water temperature was not important for those beetles. Ilybius sp. and Limnebius glabriventris correlated with altitude and humus.

Animals↗

PubMed2002

[Effect of drought stress on apparent resource utilization efficiency of Quercus mongolica].

To study the effect of drought stress on the physiological characteristics and resource utilization efficiency of Quercus mongolica, a dominant species in the Korean pine broad-leaved forest in Changbai Mountain, a comparative experiment was carried out under three soil moisture gradients as 85%-100% (high water, CK), 65%-85% (Medium water, MW), and 45%-65% (low water, LW) of field water-bolding capacity. The results showed that net photosynthetic rate, stomatal conduction, transpiration rate, water utilization efficiency, apparent CO2 utilization efficiency and apparent light utilization efficiency of the seedlings of Quercus mongolica were all significantly influenced by simulated drought stress. Stomatal conduction, water utilization efficiency and net photosynthetic rate of large tress of Quercus mongolica were affected by the soil drought stress, while transpiration rate, apparent CO2 utilization efficiency, and apparent light utilization efficiency were not influenced. Moderate soil water condition could greatly increase gas exchange and water utilization efficiency. These results indicated that the responses of gas exchange and resource utilization efficiency to various water stresses were different. Quercus mongolica was a species with variable resistance to drought stress, and the resistance would be improved by drought stress, especially moderate water stress.

Carbon Dioxide↗

PubMed2002

[Effect of elevated atmospheric CO2 concentrations on photosynthesis light response characteristics of three coniferous tree species seedlings].

Potted seedlings of Pinus koraiensis, Picea koraiensis, and Larix olgensis, the dominant coniferous tree species in Changbai Mountain, were grown under elevated CO2 concentration (700 mumol.mol-1) and ambient CO2 concentration (400 mumol.mol-1) for two year, and their photosynthesis light response curves were determined with CI-301PS CO2 gas analysis system under a series of light intensity from 0 to 2500 mumol.quanta.m-2.s-1. The comparison of dark respiration rate (DRR), maximum net photosynthetic rate (Amax), quantum use efficiency (QUE), light compensation point (LCP), light saturation point (LSP) and photo inhibition point (PP) for the seedlings of these coniferous tree species under different CO2 concentration showed that Larix olgensis, which had better adaptation of photosynthesis to elevated CO2 concentration, was heliophilous species. The shade-tolerant species Picea koraiensis showed the least adaptation of photosynthesis to elevated CO2 concentration. Furthermore, the relationship between photosynthetic physiological character of tree species and their succession status was also discussed in this paper.

Carbon Dioxide↗

PubMed2002

Transient expression of strictosidine synthase in tobacco leaves by vacuum infiltration.

Strictosidine synthase (STR) is the key enzyme involved in early steps of biosynthesis of monoterpenoid indole alkaloids. STR catalyzes the condensation of tryptamine with secologanin into strictosidine. The gene encoding STR targeted to different subcellular compartments was transiently expressed in the tobacco leaves. In vitro STR enzymatic activity was measured by the depletion of tryptamine indicated by fluorescence. The results showed that the recombinant STR was effectively expressed as soluble protein in three subcellular compartments-chloroplast, vacuole and endoplasmic reticulum in the leaves of tobacco by Western blot analysis and STR enzymatic assay.

Blotting, Western↗

PubMedDate not supplied

Differential reactions of microglia to brain metastasis of lung cancer.

The brain is a common metastatic site for various types of cancers, especially lung cancer. Patients with brain metastases have a poor prognosis in spite of radiotherapy and/or chemotherapy. It is postulated that immune cells in the brain may play a major role in cancer metastasis, dormancy, and relapse. Although microglia may serve as a major component in the brain immune system, the interaction between metastatic cancer cells and microglia is still largely unknown and remains to be elucidated. In this study, we have investigated microglial reactions in brain tissues with metastatic lung cancer cells and evaluated the cytotoxic effects of lipopolysaccharide (LPS)-activated microglia on metastatic lung cancer cells in vitro. In the vicinity of metastatic lung cancer mass in the brain, microglia showed signs of significant activation. There was an obvious increase in the number of microglia labeled with ionized calcium binding adaptor molecule 1 (Iba-1) antibody, a specific marker of microglia. The microglia were observed to form a clear boundary between the tumor mass and normal brain tissue. In the region where the tumor mass was situated, only a few microglia expressed inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-alpha), indicating differential activation in those microglia. The supernatant from LPS-activated microglia induced apoptosis of metastatic lung cancer cells in vitro in a dose- and time-dependent manner. However, at lower concentrations of activated microglial supernatant, trophic effects on cancer cells were observed, some lung cancer cells being insensitive to microglial cytotoxicity. Together with the observation that TNF-alpha alone induced proliferation of the tumor cells, the findings provide possible clues to the mechanism involved in metastasis of lung cancer cells to the brain.

Animals↗