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Biomedical subjects

Qi Wang

Publications and source records attributed to Qi Wang.

At least 91 records · Page 5Linked to original sources
PubMed2006

[Effect of acupuncture on pH values of acupoints in the goat].

OBJECTIVE: To study effect of acupuncture on pH values of acupoints and non-acupoints. METHODS: The pH values of acupoints and non-acupoints were determined with pH sense needles at the same time and separately in the goat. RESULTS: (1) The pH value of the acupoints and non-acupoints decreased when acupuncture was separately at acupoints and non-acupoints with the pH value of the acupoint decreased more significantly; (2) there was no significant difference in decreasing amplitudes of the pH values between the acupoint and non-acupoint when acupuncture was simultaneously given at acupoints and non-acupoints. CONCLUSION: Acupuncture can more significantly strengthen metabolism of acupoints; when acupuncture was simultaneously given at acupoints and non-acupoints, local metabolism is influenced each other.

Acupuncture Points↗
PubMed2006

[Screening for G1528C mutation in mitochondrial trifunctional protein gene in pregnant women with severe preeclampsia and new born infant].

OBJECTIVE: Severe preeclampsia, and hemolysis, elevated liver enzymes, and low platelet syndrome (HELLP) are serious complications of pregnancy, and evidence suggests a genetic basis for these conditions. A G1528C mutation in the alpha-subunit of the mitochondrial trifunctional protein (MTP) gene has been identified in association with these conditions. The aim of this study is to explore the carrier rate of the G1528C mutation in the MTP gene in pregnant women with severe preeclampsia, HELLP syndrome and in their newborns, as well as in a normal pregnant population, so as to determine its association with maternal liver disease among women in Beijing. METHODS: A multicenter, prospective, case control study was carried out. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to screen the G1528C mutations in the MTP gene. One hundred and forty cord blood samples from cases with severe preeclampsia (n = 130) and HELLP syndrome (n = 10) were collected. Ninety maternal peripheral blood samples among them (84 from severe preeclampsia and 6 from HELLP syndrome) were also collected for screening the common disease-causing mutation in Caucasians. Five hundred and sixty cord blood samples and 90 maternal peripheral blood samples obtained from normal pregnant women served as controls. RESULTS: The G1528C mutations in the MTP gene were not found in samples from women with severe preeclampsia and their newborns, from women with HELLP syndrome and their new borns, as well as in samples from the normal pregnant women and their new borns. CONCLUSIONS: The common disease-causing mutation of G1528C in MTP gene in Caucasians is probably not a common mutation in Chinese Han people in Beijing. Further study is needed to expand the sample size among HELLP syndrome and maternal liver diseases in Chinese population.

Case-Control Studies↗
PubMed2006

[Dynamic prediction and evaluation method of maize chilling damage].

In order to prevent and alleviate the chilling damage of maize, a dynamic prediction and evaluation method on its emergence and loss was developed by using an improved dynamic model of maize growth and dry matter accumulation, and new parameters and damage indices. The method followed the thermal constant theory and the principles of maize biology and ecology, utilized relative accumulated temperature as the leading factor of maize development stage prediction and damage discretion, and took dry matter shortage rate as the loss rate of the damage. The results of test and tryout showed that the method was objective and applicable, and suited for various places of Northeastern China through areal adjustment of parameters and indices.

Biomass↗
PubMed2005

[Surgery for iatrogenic obstruction of the second hepatic portal].

OBJECTIVE: To summarize the effects of surgery for iatrogenic obstruction of the second hepatic portal and the curative effects thereof. METHODS: Seven patients, 5 males and 2 females, aged 25-38, with iatrogenic obstruction of the second hepatic portal, due to blocking of the reflux of hepatic vein by translocated stent in 4 cases and due to occlusion of hepatic vein local thrombosis and endometrial hyperplasia caused by broken wires in 3 cases, underwent removal of the foreign bodies and plastic operation of the second hepatic portal under temporary circulatory pause and hypothermic general anesthesia via the approach of incision of the pericardium and inferior vena cava. The patients were followed up for 6 months to 5 years. RESULTS: After the operation the liver shrank and ascites was decreased significantly in all patients. The liver functions of all patients were normal during the follow-up and no complication or signs of recurrence were found. Ultrasonography and CT scan showed no stricture and stenosis. CONCLUSION: Translocation of stent is the common reason of iatrogenic obstruction of the second hepatic portal. Operational procedure including removal of the foreign bodies and plastic operation of the second hepatic portal under temporary circulatory pause and hypothermic general anesthesia via the approach of incision of the pericardium and inferior vena cava is an effective radical surgical treatment for this complication.

Adult↗
PubMed2005

Fluid structure and transport properties of water inside carbon nanotubes.

The fluid structure and transport properties of water confined in single-walled carbon nanotubes (CNTs) with different diameters have been investigated by molecular-dynamics simulation. The effects of CNT diameter, density of water, and temperature on the molecular distributions and transport behaviors of water were analyzed. It is interesting that the water molecules ordered in helix inside the (10, 10) CNT, and the layered distribution was clearly observed. It was found that the axial and radial diffusivities in CNTs were much lower than that of the bulk, and it ever decreased as the diameter of CNT decreases. The axial thermal conductivity and shear viscosity in CNTs are obviously larger than that of the bulk and those in the radial direction, they increase sharply as the diameter of CNT decreases, which is clearly in contrast to the diffusivity. The inner space of CNT and the interactions between water molecules and the confining walls play a key role in the structure and transport properties of water confined in the CNTs.

Journal Article↗
PubMed2005

High frequency induction of mitotic recombination by ionizing radiation in Mlh1 null mouse cells.

Mitotic recombination in somatic cells involves crossover events between homologous autosomal chromosomes. This process can convert a cell with a heterozygous deficiency to one with a homozygous deficiency if a mutant allele is present on one of the two homologous autosomes. Thus mitotic recombination often represents the second mutational step in tumor suppressor gene inactivation. In this study we examined the frequency and spectrum of ionizing radiation (IR)-induced autosomal mutations affecting Aprt expression in a mouse kidney cell line null for the Mlh1 mismatch repair (MMR) gene. The mutant frequency results demonstrated high frequency induction of mutations by IR exposure and the spectral analysis revealed that most of this response was due to the induction of mitotic recombinational events. High frequency induction of mitotic recombination was not observed in a DNA repair-proficient cell line or in a cell line with an MMR-independent mutator phenotype. These results demonstrate that IR exposure can initiate a process leading to mitotic recombinational events and that MMR function suppresses these events from occurring.

Adaptor Proteins, Signal Transducing↗
PubMed2005

Dynamics and density profile of water in nanotubes as one-dimensional fluid.

The transport and structural properties of water confined in nanotubes with different diameters were studied by molecular dynamics (MD) simulation. The effects of pore size, molecule-wall interaction, and the helicity of CNT on the diffusivity, thermal conductivity, and shear viscosity as well as density profile were analyzed. For diffusivity, in model NT > in armchair CNT > in zigzag CNT at similar conditions. However in contrast to the diffusivity, the thermal conductivity and the shear viscosity increase as the pore size decreases, in zigzag CNT > in armchair CNT > (or approximately ) in model NT. The ordered layer distribution of water molecules in nanotubes is clear. It suggests the structure of fluid in the zigzag CNTs is more ordered, and more solidlike. In the nanotubes, where the molecule and the pore dimensions are of similar order of magnitude, the nature of water-water and water-wall interactions, the confinement effect of space, and the helicity of CNT become more significant.

Molecular Dynamics Simulation↗
PubMed2005

Overexpression of endoplasmic reticulum molecular chaperone GRP94 and GRP78 in human lung cancer tissues and its significance.

BACKGROUND: To investigate the relationship between the expression of glucose-regulated protein94 (GRP94) and GRP78 at the level of mRNA and protein in vivo and in human lung cancer. METHODS: RT-PCR, real-time PCR, immunohistochemistry and/or Western blot were used in 54 cases of lung cancer and corresponding normal lung tissue. RESULTS: The expression pattern of GRP94 and GRP78 was similar. There was a significant overexpression of GRP94 and GRP78 at both mRNA and protein levels in cancer tissues as compared to normal tissues. The relative levels of GRP94 and GRP78 mRNA evaluated by RT-PCR in cancer and normal lung tissue were: GRP94: 3.48+/-2.06 versus 2.01+/-1.83; GRP78: 3.64+/-1.87 versus 2.21+/-1.54; by real-time PCR were: GRP94: 2.89+/-0.64 versus 1.12+/-0.54; GRP78: 2.56+/-0.82 versus 0.96+/-0.42. The relative level of GRP94 and GRP78 protein by Western blot in cancer and normal lung tissue were: GRP94: 3.46+/-1.72 versus 1.81+/-0.92; GRP78: 4.84+/-2.55 versus 1.91+/-1.15, indicating an approximate 2-fold and a 3-fold increase in GRP94 and GRP78 protein in cancer tissue as compared with normal tissue. Immunohistochemistry result for GRP94 and GRP78 in cancer and normal tissue was similar, that is: a stronger stain was observed in cancer tissue (main intensity of staining ++ to +++) compared to normal tissue (main intensity of staining + to ++). All the difference for GRP94 and GRP78 between the two tissues were significant (p<0.05). Furthermore, the overexpression of GRP94 and GRP78 in the cancer tissue correlated with grade of differentiation and stage of tumors. There was stronger expression in poorly differentiated tumors than in well-moderately differentiated tumors (p<0.05). There was also stronger expression in stage III than in stages I and II tumors (p<0.05). No statistically significant differences were found among various pathologic types of tumors. Correlation analysis showed that there is a positive correlation between GRP94 and GRP78. CONCLUSION: The expression pattern of GRP94 and GRP78 was similar in human lung cancer. They both were related with the differentiation and progression of the cancer. The expression at mRNA and protein level may be valuable in evaluating the grade of differentiation and clinical stage of human lung cancer.

Adult↗
PubMed2005

Synchrotron-based infrared and X-ray imaging shows focalized accumulation of Cu and Zn co-localized with beta-amyloid deposits in Alzheimer's disease.

Alzheimer's disease (AD) is characterized by the misfolding and plaque-like accumulation of a naturally occurring peptide in the brain called amyloid beta (Abeta). Recently, this process has been associated with the binding of metal ions such as iron (Fe), copper (Cu), and zinc (Zn). It is thought that metal dyshomeostasis is involved in protein misfolding and may lead to oxidative stress and neuronal damage. However, the exact role of the misfolded proteins and metal ions in the degenerative process of AD is not yet clear. In this study, we used synchrotron Fourier transform infrared micro-spectroscopy (FTIRM) to image the in situ secondary structure of the amyloid plaques in brain tissue of AD patients. These results were spatially correlated with metal ion accumulation in the same tissue sample using synchrotron X-ray fluorescence (SXRF) microprobe. For both techniques, a spatial resolution of 5-10 microm was achieved. FTIRM results showed that the amyloid plaques have elevated beta-sheet content, as demonstrated by a strong amide I absorbance at 1625cm(-1). Using SXRF microprobe, we find that AD tissue also contains "hot spots" of accumulated metal ions, specifically Cu and Zn, with a strong spatial correlation between these two ions. The "hot spots" of accumulated Zn and Cu were co-localized with beta-amyloid plaques. Thus for the first time, a strong spatial correlation has been observed between elevated beta-sheet content in Abeta plaques and accumulated Cu and Zn ions, emphasizing an association of metal ions with amyloid formation in AD.

Alzheimer Disease↗
PubMed2005

[Effect of pueraria crude extreact and puerarin on ethanol-induced expression of heat shock protein 70 in embryonic mouse hippocampal cultures].

OBJECTIVE: To study if the Pueraria crude extreact (CP) and standard preparation of pure puerarin (SP) possess the same neuroprotective effects on the expression of heat shock protein (HSP) 70 in the embryonic mouse hippocampal cells. METHODS: The hippocampus of 18-days-old mouse embryo was taken out and suspension of single cells was cultured. Ethanol was added to cause HSP70 mRNA expression. Solvent, ethanol of different concentrations (50, 200, and 300 mmol/L), SP + ethanol, and SP + ethanol were added respectively. Western blotting was used to detect the expression of the expression of HSP70 mRNA. RESULTS: Ethanol of different concentrations increased the expression of HSP70 mRNA and the protein in comparison with the solvent control group. SP and CP inhibited the expression of HSP70 mRNA and protein. CONCLUSION: With identical effect of anti-oxidative stress, both SP and CP inhibit the increase of expression of HSP70 mRNA and protein, thus demonstrating I vitro anti-oxidative neuroprotection.

Animals↗
PubMed2005

Hydrodynamic theories for mixtures of polymers and rodlike liquid crystalline polymers.

We develop a hydrodynamic theory for flows of incompressible blends of flexible polymers and rodlike nematic polymers (RNPs) or rodlike nematic liquid crystal polymers (RNLCPs) extending the thermodynamical theory of Muratov and E [J. Chem. Phys. 116, 4723 (2002)] for phase separation kinetics of the blend. We model the flexible polymer molecules in the polymer matrix as Rouse chains and assume the translational diffusion of the molecules is predominantly through the volume fraction of the flexible polymer and the molecules of rodlike nematic liquid crystal polymers. We then (i) derive the translational flux for the rodlike nematic liquid crystal polymers to ensure the incompressibility constraint; (ii) derive the elastic stress tensor, accounting for the contribution from both the rodlike nematic polymer and the flexible polymer matrix, as well as the extra elastic body force due to the nonlocal intermolecular potential for long range molecular interaction; (iii) show that the theory obeys positive entropy production and thereby satisfies the second law of thermodynamics. By applying the gradient expansion technique on the number density function of RNLCPs, we present an approximate, weakly nonlocal theory in differential form in which the intermolecular potential is given by gradients of the number density function of the RNLCP and the volume fraction of the flexible polymer. In the approximate theory, the elastic stress is augmented by an extra stress tensor due to the spatial convection of the macroscopic material point and long range interaction, whose divergence yields the analogous extra elastic body force with respect to the nonlocal intermolecular potential. Finally, we compare the model in steady simple shear with the Doi theory for bulk monodomains of rodlike nematic polymers.

Journal Article↗
PubMed2005

Molecular dynamics simulation of self- and mutual diffusion coefficients for confined mixtures.

The self- and mutual diffusion coefficients for binary mixtures of Ar-Kr both in the bulk and in the nanopores were studied by molecular dynamics simulations. The composition dependences and the relationships between the self- and the mutual diffusion coefficients both in the bulk and in the nanopores were further discussed. It was found that the simulation results (D(c.m.)) are close to the calculated ones (D(s)) for the Ar-Kr system. Both self- and mutual diffusion coefficients in nanopores are much lower than that of the bulk, and they ever decrease as the pore width decreases. Nevertheless, the self- and mutual diffusion coefficients increase as the mole fraction of Ar increases, and as expected, increase as the temperature increases. The self-diffusion coefficients of mixtures both in the bulk and in the nanopores are predicted by the Carman model and by the molecular cluster model.

Journal Article↗
PubMed2005

Molecular characterisation of soybean polysaccharides: an approach by size exclusion chromatography, dynamic and static light scattering methods.

Water soluble polysaccharides from soybean (SSPS) have a pectin-like structure and are used as stabilisers in acidified beverages. Physicochemical properties such as structure, molecular weight and shape or conformation are primary factors controlling their functional properties. Two soybean polysaccharides, a native SSPS and a modified SSPS treated with beta-(1-->4)-D-galactosidase (GPase/SSPS) were studied by dynamic and static light scattering (DLS, SLS) and size exclusion chromatography (SEC). Consecutive filtrations using a range of membrane pore size removed a small fraction of macromolecular aggregates from dilute polysaccharide solutions with relatively little effect on the major component molecules as monitored by DLS and SEC measurements. Access to aggregate-free dilute solutions of SSPS and GPase/SSPS allowed the direct measurement of molecular characteristics. SLS results showed that SSPS had a weight average molecular weight of (645+/-11)x 10(3)g/mol and a radius of gyration, Rg, of (23.5+/-2.8)nm. By comparing R(g) with the hydrodynamic radius, Rh (21.1+/-0.5 nm) obtained from DLS, the structural parameter rho (Rg/Rh) was found to be 1.1, suggesting that SSPS has an overall globular shape due to a highly branched structure. The modified SSPS had a significantly lower molecular weight (287+/-18)x 10(3)g/mol but a similar radius of gyration (23.2+/-1.7 nm). The structure parameter rho of GPase/SSPS was higher (rho=1.3) because of a smaller hydrodynamic radius (17.7+/-1.8 nm). This suggests that GPase/SSPS has a much less branched structure yet still differs significantly from a linear random coil conformation (rho=1.7-2.0). The results derived from SLS and DLS are in agreement with the conclusions obtained from a chemical analysis where the reduction of molecular weight of GPase/SSPS was caused by the cleavage of galactan side chains.

Carbohydrates↗
PubMed2005

Nonlocal incoherent white-light solitons in logarithmically nonlinear media.

The propagation properties of white-light solitons in spatially nonlocal media with a logarithmically nonlinearity are investigated theoretically. The existence curve of the stationary nonlocal incoherent soliton is obtained and the coherence characteristics of the soliton are also described. The evolution behaviors of the nonlocal white-light soliton are discussed in detail by both approximate analytical solution and numerical simulation when the solitons undergo periodic oscillation.

Journal Article↗
PubMed2005

Anti-apoptotic role of BARF1 in gastric cancer cells.

Epstein-Barr virus (EBV) infection has been implicated in the carcinogenesis of several types of human cancer, including gastric cancer. In contrast to two other EBV-related malingancies, nasopharyngeal carcinoma and Hodgkins Lympomain which the latent membrane protein (LMP)-1 is often detected, in gastric cancer, BARF1, one of the early EBV genes, is frequently expressed in EBV-positive specimens. This indicates that expression of BARF1 may play a positive role in the development of gastric cancer. The aim of this study was to investigate the effect of BARF1 expression in gastric cancer cells. First, a retroviral vector containing the full length BARF1 gene was transfected into an EBV negative gastric cancer cell line, BGC823, and stable transfectants expressing ectopic BARF1 were generated. Microarray analysis was then performed and gene expression profiles were analysed and compared between the cells expressing ectopic BARF1 and the vector control. In addition, the effect of BARF1 on gastric cancer cell proliferation and apoptosis was investigated by MTT assay, DAPI staining, flow cytometry as well as Western blotting. We found that expression of BARF1 in gastric cancer cells led to significant alterations of gene expression, especially genes related to proliferation and apoptosis. In addition, the BARF1 expressing cells were more resistant to apoptosis induced by a commonly used anticancer drug, taxol. This chemo-protective effect of BARF1 was associated with increased Bcl-2 and Bax ratio and decreased expression of cleaved PARP, but not alterations in cell proliferation. Our results suggest that BARF1 expression in gastric cancer cells may provide a protective role against apoptosis through an increased Bcl-2 to Bax ratio, thus promoting cancer cell survival.

Antineoplastic Agents, Phytogenic↗
PubMed2005

Selective expression of the Cre recombinase in late-stage thymocytes using the distal promoter of the Lck gene.

Transgenic mouse lines were generated that express the Cre recombinase under the control of the distal promoter of the mouse Lck gene. Cre recombination in four of these lines of transgenic mice was characterized at the single cell level using ROSA26-regulated loxP-Stop-loxP-betageo and loxP-Stop-loxP-YFP reporter mouse lines. Two of the lines showed T cell-restricted Cre recombination, whereas the other two also expressed Cre in B cells, NK cells, and monocytes. Cre recombination began at a late stage of T cell development (at or after up-regulation of the TCR during positive selection) in the two T cell-restricted lines. Lines of mice that express the Cre recombinase at late stages of thymocyte development are of value for determining the impact of mutations on T cell function in the absence of complicating effects on early thymocyte selection.

Animals↗