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Biomedical subjects

Wei Wang

Publications and source records attributed to Wei Wang.

At least 361 records · Page 20Linked to original sources
PubMed2006

[Application of ICP-AES to the chemical speciation of heavy metals in flyash].

Chemical speciation of seven heavy metals of flyashes in incinerator was quantitatively tested using ICP-AES. Results showed that ICP-AES procedure could carry out quick, exact and high precision experiments. RSD ratio for most detected metals was lower than 3% while few metals present a comparatively high RSD when whose content was near the detection limits. The recovery ratio was 85.7%-100.63% flyashes were found to have high content of Zn, Pb. Cd, Cu, Mn, Pb and Zn existed mostly as carbonates and were leachable, while Cr and Ni were combined to metal oxides substrates and present immobilization characteristics.

Cadmium↗
PubMed2006

[A controlled clinical trial of long course chemotherapy regimens containing rifabutin in the treatment of multi-drug resistant pulmonary tuberculosis].

OBJECTIVE: To evaluate the curative effect and safety of a long course regimen containing Chinese-made rifabutin as compared to the regimen containing rifapentine in the treatment of multi-drug resistant pulmonary tuberculosis. METHOD: During 18 month treatment, 130 patients with multi-drug resistant pulmonary tuberculosis were divided into a treatment group (rifabutin, pasiniazide, levofloxacin, ethambutol, ethionamide, amikacin for 3 months, rifabutin, pasiniazide, levofloxacin, ethambutol, ethionamide for 6 months, rifabutin, pasiniazide, levofloxacin, ethambutol for 9 months), and a control group (rifapentine, pasiniazide, levofloxacin, ethambutol, ethionamide, amikacin for 3 months, rifabutin, pasiniazide, levofloxacin, ethambutol, ethionamide for 6 months, rifabutin, pasiniazide, levofloxacin, ethambutol for 9 months) with proportion 1:1 random, and parallel compared method. RESULTS: After intensive phase, the sputum negative conversion rates (smear negative, culture negative) of the treatment group and the control group were 41.54% (27/65) and 35.94% (23/65), chi(2) = 2.42, P > 0.05, respectively. The remarkable effective rates in chest X-ray of the two groups were all 10.77% (7/65), chi(2) = 0.01, P > 0.05, and the effective rates were 67.69% (44/65) and 56.92% (37/65), chi(2) = 1.44, P > 0.05, respectively. At the end of the treatment, the sputum negative conversion rate (smear negative, culture negative) of the treatment group was 75.0% (48/65), and of the control group was 65.08% (41/65), chi(2) = 1.88, P > 0.05. The remarkable effective rates in chest X-ray of the two groups were 46.15% (30/65) and 44.62% (29/65), chi(2) = 0.02, P > 0.05, and the effective rates were 76.92% (50/65) and 73.85% (48/65), chi(2) = 0.19, P > 0.05, respectively. The cavity closure rates were 23.64% (13/55) and 33.33% (17/51), chi(2) = 0.00, P > 0.05, respectively. CONCLUSION: Regimens containing rifabutin or rifapentine. are very effective in sputum negative conversion rate, lesion absorption and cavity closing for the treatment of multi-drug resistant pulmonary tuberculosis, with good safety and tolerance.

Adult↗
PubMed2006

Nucleocapsid amino acids 211 to 254, in particular, tetrad glutamines, are essential for the interaction between the nucleocapsid and membrane proteins of SARS-associated coronavirus.

GST pull-down assays were used to characterize the SARS-CoV membrane (M) and nucleocapsid (N) interaction, and it was found that the amino acids 211-254 of N protein were essential for this interaction. When tetrad glutamines (Q) were replaced with glutamic acids (E) at positions of 240-243 of the N protein, the interaction was disrupted.

Amino Acid Substitution↗
PubMed2006

[Effect of glucosidorum tripterygii tororum on acute graft-versus-host disease in mice].

To prevent acute graft-versus-host disease (aGVHD), glucosidorum tripterygii tororum (GTT) was used in the murine model. The lethally irradiated C57BL/6 recipients were injected with bone marrow and lymphocyte grafts from BALB/c donors and were treated intraperitoneally with GTT, cyclosporine A (CsA), or methotrexate (MTX). T lymphocytes, adhesion molecules and cytokines were detected by immunohistochemical method, flow cytometry, ELISA and RT-PCR, respectively. The results showed that all the control recipient mice (21/21) died of aGVHD within 30 days, but many recipient mice treated with GTT (19/21), CsA + MTX (13/21) and GTT + CsA (17/21) survived beyond 30 days without obvious signs of aGVHD. The numbers of CD3(+), CD4(+), CD8(+), CD11a(+), CD18(+) lymphocytes in skin and lung decreased markedly by GTT, GTT + CsA and CsA + MTX treatments. The numbers of CD3(+), CD4(+), CD8(+), CD4(+)CD11a(+), CD4(+)CD18(+), CD8(+)CD11a(+), CD8(+)CD18(+) lymphocytes in spleen decreased markedly by GTT, GTT + CsA and CsA + MTX treatments. and the changes of CD3(+), CD4(+), CD8(+) cells in small intestine were not remarkable (P > 0.05) by above mentioned GTT, GTT + CsA and CsA + MTX treatments. The serum concentrations and mRNA expressions of IL-2 and TNFalpha in spleens decreased significantly (P < 0.05); the concentration of IL-10 increased significantly (P < 0.05), the change of IL-4 was not remarkable (P > 0.05) by GTT treatment. It is concluded that the GTT may retain the graft-versus-leukemia (GVL) effect of transplant without aGVHD. The role of GTT in prevention of murine aGVHD is mediated by reduction of T lymphocytes and their subgroups, expression of adhesion molecule, and regulation of cytokine secretion.

Animals↗
PubMed2006

[Multilevel model analysis on the influence of smoking among university students in Tianjin].

OBJECTIVE: To study the influencing factors of smoking among university students on individual and classes level by multilevel model and to identify high risk groups in order to develop pertinent prevention measures which can decrease smoking behavior among university students. METHODS: Self-reported data on knowledge, attitude and behavior on smoking coming from a randomly clustered sampling of 24 classes in students from 12 universities in Tianjin. RESULTS: Through analyses of 743 questionnaires from university students, we learned that the occasional smoking rate was 10.0% , the regular smoking rate was 7.4% and 5.9% had given up smoking. The influencing factors for students who smoked occasionally and regularily were gender (OR values were 0.243 and 0. 186), moods (OR values were 0.071 and 0.078) and environment (OR values were 2.722 and 19.075). Gender (OR value was 0. 180), age (OR value was 1.567), moods (OR value was 0.221) and environment (OR value was 2.776) had positive influences on students in giving up their smoking behavior. CONCLUSION: According to the different status of university students, different measures should be taken to prevent smoking and to change thier smoking behavior.

China↗
PubMed2006

[Molecular characterization of O-antigen gene cluster of Escherichia coli O23 reference strain and identification of UDP-N-acetylglucosamine 4-epimerase].

Lipopolysaccharide (LPS) is one of the major components of the outer membrane of gram-negative bacteria. It is an amphipathic molecule composing of lipid A, a core oligosaccharide and an O-specific antigen. O-antigen, which is a repeat unit polysaccharide, is a major contribution to the antigenic variability of the bacterial cell surface. Genes involved in O-antigen biosynthesis are generally found to be clustered between the housekeeping genes galF and gnd on the chromosome of E. coli. E. coli O23 is one of the enterotoxigenic E. coli causing pediatric diarrhea in the developing world. The O-antigen gene cluster of E. coli O23 type strain was amplified by long-range PCR using primers based on galF and gnd and then sequenced. Except for galF and gnd, seven open reading frames were identified and assigned functions on the basis of their similarity to those from available databases. The seven genes include a UDP-N-acetylglucosamine 4-epimerase gene (gne), the O-antigen polymerase gene (wzy), the O-antigen transferase gene (wzx) and four glycosyltransferase genes (orf2, orf4, orf5, orf6). The UDP-N-acetylglucosamine 4-epimerase (Gne) was identified by mutation and complementation complement tests. The structure of Gne was predicted by the homology modeling method, and the active sites were also analyzed. The phylogenetic and structural analysis showed that the Gne derived from the common ancestor with E. coli O23 Gne were UDP-GlcNAc/UDP-GalNAc epimerases. The specific DNA used for rapid molecular genotyping for E. coli O23 was also identified.

Base Sequence↗
PubMed2006

[Sequence analysis of HLA-B*4061 allele newly found].

The aim of this study was aimed to investigate the molecular genetic basis for a novel HLA allele, HLA-B*4061, in Chinese population. DNA was extracted from whole blood by salting-out method. The HLA-B exons 1 - 8 of the proband was amplified and the amplified product was cloned using TOPO TA cloning sequencing kit to split the two alleles apart. Both strands of exons 2, 3 and 4 of chosen colonies were sequencing. The PCR-SSP was performed to confirm the mutations detected by sequencing. The sequencing results showed HLA-B alleles of the proband as B*4601 and the novel allele. The sequences of the novel allele have been submitted to GenBank (DQ089628, DQ089629, DQ089630). After HLA blast analysis, the novel allele showed a single nucleotide mismatch with B*400101 in exon 2 at position 272 C-->A, as the results, changing amino acid from Ser to Tyr at codon 67. It is concluded that this allele is a novel one and has been officially named B*4061 by the WHO Nomenclature Committee.

Alleles↗
PubMed2006

[Porcine endogenous retrovirus in Daweizi pigs in Hunan].

OBJECTIVE: To detect porcine endogenous retrovirus (PERV) in Daweizi pigs and to provide basic parameters of evaluating the biological safety for xenotransplantation from pigs to humans. METHODS: Ear tissues from 42 individuals were randomly collected from a Daweizi pig population. PCR and RT-PCR were performed to detect PERV proviral DNA and mRNA respectively. Finally, env-A, env-B, and env-C were amplified, sequenced, and analyzed using the BLAST software in National Center for Biotechnology Information. RESULTS: PERV proviral DNA and mRNA could be detected in the 42 individuals by PCR and RT-PCR, respectively. env-A, env-B and env-C were detected in all the individuals. Compared with other pig species (AY288779, DQ011794 and AY534304), there was 1 and 8 bp differences in the sequences of env-A and env-C, while no difference in env-B. CONCLUSION: PERV exists and has transcriptive activity in Daweizi pigs. The predominate subtype is PERV-ABC. Env genes are firstly cloned and sequenced in Daweizi pigs and there are polymorphism in the breed. As to the biological safety, the breed was not suitable as a donor in xenotransplantation.

Animals↗
PubMed2006

[Distribution and morphological changes of corneal nerves in type 2 diabetic patients detected by confocal microscopy].

OBJECTIVE: To evaluate corneal nerve distribution and morphological changes in subjects with type 2 diabetes. METHODS: Sixty-five eyes of 59 patients with type 2 diabetes (26 males, 39 females) and 26 eyes (10 males, 16 females) of control subjects were included in the present study. Based on the indirect ophthalmoscopic examination and fluorescein angiography, the diabetic group was divided into three sub-groups according to the stage of retinopathy: without diabetic retinopathy (NDR), non-proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR). The central cornea was scanned with Confoscan 3.0. The images of subbasal nerve plexus and stromal nerves were analyzed. RESULTS: Corneal branch nerve fiber density of subbasal nerve plexus decreased in diabetic group as compared with control group, the difference was statistically significant. The decrease of nerve fiber density appeared only in the PDR sub-group, while the decrease was not significant in NDR and NPDR sub-groups. No obviously difference was found among control group, NDR and NPDR sub-groups. The proportion of patients with an abnormal morphologic nerve fibers in mid-stroma in diabetes group was greater than that in the control group and the difference was statistically significant (chi(2) = 46.613, P = 0.000). CONCLUSIONS: Corneal confocal microscope allows rapid and noninvasive in vivo evaluation of corneal nerves. The subbasal and stromal nerves of subjects with type 2 diabetes were abnormal in morphology.

Aged↗
PubMed2005

TNF-alpha contributes to endothelial dysfunction in ischemia/reperfusion injury.

BACKGROUND: Despite the importance of endothelial function for coronary regulation, there is little information and virtually no consensus about the causal mechanisms of endothelial dysfunction in myocardial ischemia/reperfusion (I/R) injury. Because tumor necrosis factor-alpha (TNF-alpha) is reportedly expressed during ischemia and can induce vascular inflammation leading to endothelial dysfunction, we hypothesized that this inflammatory cytokine may play a pivotal role in I/R injury-induced coronary endothelial dysfunction. METHODS AND RESULTS: To test this hypothesis, we used a murine model of I/R (30 minutes/90 minutes) in conjunction with neutralizing antibodies to block the actions of TNF-alpha. TNF-alpha expression was increased >4-fold after I/R. To determine whether TNF-alpha abrogates endothelial function after I/R, we assessed endothelial-dependent (ACh) and endothelial-independent (SNP) vasodilation. In sham controls, ACh induced dose-dependent vasodilation that was blocked by the nitric oxide synthase (NOS) inhibitor L-NMMA (10 micromol/L), suggesting a key role for NO. In the I/R group, dilation to ACh was blunted, but SNP-induced dilation was preserved. Subsequent incubation of vessels with the superoxide (O2*-) scavenger (TEMPOL), or with the inhibitors of xanthine oxidase (allopurinol, oxypurinol), or previous administration of anti-TNF-alpha restored endothelium-dependent dilation in the I/R group and reduced I/R-stimulated O2*- production in arteriolar endothelial cells. Activation of xanthine oxidase with I/R was prevented by allopurinol or anti-TNF-alpha. CONCLUSIONS: These results suggest that myocardial I/R initiates expression of TNF-alpha, which induces activation of xanthine oxidase and production of O2*-, leading to coronary endothelial dysfunction.

Acetylcholine↗
PubMed2005

Selective modulation of L-type calcium current by magnesium lithospermate B in guinea-pig ventricular myocytes.

Magnesium lithospermate B (MLB) is the main water-soluble principle of Salviae Miltiorrhizae Radix (also called as 'Danshen' in the traditional Chinese medicine) for the treatment of cardiovascular diseases. MLB was found to possess a variety of pharmacological actions. However, it is unclear whether and how MLB affects the cardiac ion channels. In the present study, the effects of MLB on the voltage-activated ionic currents were investigated in single ventricular myocytes of adult guinea pigs. MLB reversibly inhibited L-type Ca(2+) current (I(Ca,L)). The inhibition was use-dependent and voltage-dependent (the IC(50) value of MLB was 30 microM and 393 microM, respectively, at the holding potential of -50 mV and -100 mV). In the presence of 100 microM MLB, both the activation and steady-state inactivation curves of I(Ca,L) were markedly shifted to hyperpolarizing membrane potentials, whereas the time course of recovery of I(Ca,L) from inactivation was not altered. MLB up to 300 microM had no significant effect on the fast-inactivating Na(+) current (I(Na)), delayed rectifier K(+) current (I(K)) and inward rectifier K(+) current (I(K1)). The results suggest that the voltage-dependent Ca(2+) antagonistic effect of MLB work in concert with its antioxidant action for attenuating heart ischemic injury.

Animals↗
PubMed2005

Tramadol and dihydroetorphine produce synergistic analgesic effect and postpones acute opiate tolerance in rats.

The present study investigated whether a co-application of tramadol (TRA) and dihydroetorphine (DHE) would exert a synergy in analgesic effect and delay acute tolerance development. Intraperitoneal injection of TRA (in mg) and subcutaneous injection of DHE (in ng) were delivered in fixed proportions (1:6.25, 1:12.5, 1:25, 1:50, 1:100, and 1:200). The effect of analgesia was accessed by tail-flick test and analyzed with isobolographic analysis. For test of acute tolerance, six successive injections of either TRA (20 mg/kg) alone, DHE (1 000 ng/kg) alone, or a combination of TRA (20 mg/kg) and DHE (250 ng/kg) were administered. We found that (1) except for 1 mg : 6.25 ng and 1 mg : 50 ng, combinations, all the other ratios produced a significant synergy in their analgesic effect; (2) the effect of analgesia induced by repeated TRA plus DHE injections lasted significantly longer, indicating a slower onset of acute tolerance. These results indicate that TRA and DHE injections in certain dose ratios can induce synergistic analgesia, which is resistant against the development of acute tolerance.

Analgesics, Opioid↗
PubMed2005

[Microenvironment effect of APA microcapsule on embryonic stem cell].

We undertook a series of studies to evaluate the role of microenvironment during embryonic stem cell (ESC) proliferation and differentiation. In this paper, cell microencapsulation technology was employed, which allows the free exchange of nutrients, oxygen and biologically active products between the entrapped cell and culture medium. We analyzed the feasibility of mouse ESCs in microcapsules and evaluated the growth, metabolic activity and differentiation of ESCs once enclosed in alginate-Ca(2+) microbead, solid or liquefied core alginate-poly-lysine-alginate (APA) microcapsule, respectively. We found that ESCs grew gradually in both types of microcapsules, but the appearance of cells was distinctive for each type of capsule. In the case of unliquefied microcapsules, cells created multiple spherical or lens-shaped aggregates. In contrast, the liquefied alginate core allowed the enclosed ESCs to grow together in a clump at the periphery of the capsule. Combined with cell viability and activity of glucose/lactic acid metabolism, the liquefied core of APA might provide more suitable culture conditions for the ESC growth in comparison with the unliquefied type or alginate-Ca(2+). For better evaluating the nature of ESC growth in APA microcapsules in vitro (that is whether or not encapsulated ESCs maintained undifferentiated state while they kept the ability for proliferation), the expression of the typical markers for undifferentiated, dividing ESCs, such as the stage specific embryonic antigen (SSEA-1) and alkaline phosphatase (AP), was detected by immunochemistry and immunofluorescence staining. The results showed that cell aggregates formed in the microcapsule still expressed the marker proteins at a higher level on day 22 in vitro. The expression of gene Oct-4, a transcription factor necessary for maintaining ESCs in an undifferentiated state, was also detected when RT-PCR assay was employed (on day 22 in vitro). In addition, cell aggregates were released from the microcapsules by mechanical disruption and induced into insulin-producing cells. These findings further indicate that most of the ESCs in APA microcapsule maintain their multi-potential even though the culture time prolonged as long as 22 d in vitro. Taken together, APA microcapsule provides a suitable microenvironment that promotes ESCs to maintain their stemness. Therefore, the microenvironment plays an important role in the process of ESC proliferation and differentiation.

Alginates↗
PubMed2005

Mechanism studies of the conversion of 13C-labeled n-butane on zeolite H-ZSM-5 by using 13C magic angle spinning NMR spectroscopy and GC-MS analysis.

By using 13C MAS NMR spectroscopy (MAS = magic angle spinning), the conversion of selectively 13C-labeled n-butane on zeolite H-ZSM-5 at 430-470 K has been demonstrated to proceed through two pathways: 1) scrambling of the selective 13C-label in the n-butane molecule, and 2) oligomerization-cracking and conjunct polymerization. The latter processes (2) produce isobutane and propane simultaneously with alkyl-substituted cyclopentenyl cations and condensed aromatic compounds. In situ 13C MAS NMR and complementary ex situ GC-MS data provided evidence for a monomolecular mechanism of the 13C-label scrambling, whereas both isobutane and propane are formed through intermolecular pathways. According to 13C MAS NMR kinetic measurements, both pathways proceed with nearly the same activation energies (E(a) = 75 kJ mol(-1) for the scrambling and 71 kJ mol(-1) for isobutane and propane formation). This can be rationalized by considering the intermolecular hydride transfer between a primarily initiated carbenium ion and n-butane as being the rate-determining stage of the n-butane conversion on zeolite H-ZSM-5.

Journal Article↗
PubMed2005

Stage-dependent analgesia of electro-acupuncture in a mouse model of cutaneous cancer pain.

Acupuncture is one of the most effective alternative medical treatments in pain management with the advantages of simple application, low cost and minimal side effects. However its scientific evidence and laws of action are not very clear in cancer pain relieving. The aim of this study was to examine the immediate and therapeutic anti-hyperalgesic effect of electro-acupuncture (EA) on a mouse model of cutaneous cancer pain. B16-BL6 melanoma cells were inoculated into the plantar region of unilateral hind paw and the thermal hyperalgesia was measured by using radiant heat test and hot plate test. C57BL/6 mice showed moderate and marked hyperalgesia during days 8-12 and from day 14 after the orthotopic inoculation of B16-BL6 melanoma cells into the hind paw. Single EA on day 8 after inoculation showed significant analgesic effect immediately after the treatment, the analgesic effect reached its maximum within 15-30min and declined to its minimum at 50min after EA treatment. Single EA treatment on day 20 showed no significant analgesic effect; Repeated EA treatments (started from day 8, once every other day) showed therapeutic analgesic effect, while it showed no therapeutic effect when started from day 16, a relatively late stage of this cancer pain model. The results demonstrated that EA had anti-hyperalgesic effect on early stage of cutaneous cancer pain but not on late stage. These results indicated a tight correlation of EA anti-hyperalgesic effects with the time window of cancer pain.

Animals↗
PubMed2005

Determination of lactate dehydrogenase isoenzymes in single rat glioma cells by capillary electrophoresis with electrochemical detection.

A method for determination of lactate dehydrogenase (LDH) isoenzymes in single rat glioma cells (C6) was developed. In this method, a whole cell was electrokinetically injected into the front end of the separation capillary. After that, the cell was lysed by ultrasonication and the isoenzymes in the cell were pre-separated at 20 kV for 5 min and then incubated for 2 min with the enzyme substrates nicotinamide adenine dinucleotide (NAD(+)) and lactate in the capillary electrophoresis running buffer. The electroactive product NADH generated by the isoenzymes through on-capillary enzyme-catalyzed reaction was detected at the outlet of capillary by using the end-capillary amperometric detection with a constant potential mode at a carbon fiber bundle microdisk electrode. Since the amplification of signal via the enzyme reaction, the concentration of nicotinamide adenine dinucleotide (NADH) is much higher than that of LDH. The external standardization was used to quantify isoenzymes in individual cells. Three LDH isoenzymes in single rat glioma cells (C6) were determined and quantified.

Animals↗
PubMed2005

A study on the chemical and mineralogical characterization of MSWI fly ash using a sequential extraction procedure.

The presence of heavy metals in municipal solid waste incineration (MSWI) fly ash is of environmental concern due to their leaching potential in landfill environments. Sequential chemical extraction was performed on fly ash samples from a large-scale municipal solid waste incineration plant in East China. The transformation of the mineralogical species of fly ash during the sequential extraction was studied using X-ray fluorescence (XRF) and X-ray powder diffraction (XRD). The leaching behavior of heavy metals such as zinc, lead, cadmium and copper in MSWI fly ash was considered to have a dependency relationship with the components of calcium, such as aphthitalite, calcite, anhydrite and calcium aluminate or calcium aluminosilicate.

Carbon↗