Biomedical subjects

Hui Wang

Publications and source records attributed to Hui Wang.

At least 307 records · Page 17Linked to original sources

PubMed2004

[Plasmid-mediated cephalosporinase among extended-spectrum-beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae].

OBJECTIVE: To investigate the prevalence and genotype of plasmid-mediated cephalosporinase (AmpC) beta-lactamase in extended-spectrum-beta-lactamase-producing (ESBL) Escherichia coli and Klebsiella pneumoniae. METHODS: 24 strains of cefoxitin-resistant ESBL-producing E. coli and 8 strains of K. pneumoniae were collected from January to December 2001 at Beijing Chaoyang Hospital. Analytical isoelectric focusing electrophoresis was used to measure the pI of the beta-lactamase. Conjugation experiment was used to study the transfer of cefoxitin resistance. The homology of the isolates was determined by pulsed field gel electrophoresis (PFGE). Plasmid-mediated AmpC enzyme genes were amplified and sequenced by using multiplex PCR. RESULTS: The prevalence of ESBL-producing E. coli and K. pneumoniae were 16.8% (49/292) and 16.5% (35/212), respectively. The prevalence of AmpC enzyme among ESBL-producing E. coli and K. pneumoniae isolates were 2.0% (1/49) and 17.1% (6/35), respectively. These 7 isolates produced DHA-1 AmpC enzyme. One strain of K. pneumoniae could transfer cefoxitin resistance to the recipient. Among 7strains, 5 strains produced CTX-M-3 and 2 produced SHV-12 ESBL. These 7 strains also produced TEM-1 broad-spectrum enzymes. These strains harbored 2 - 5 plasmids and one of them were 33 - 36 kb. PFGE showed these strains came from a variety of clones. CONCLUSIONS: In this hospital, 7 strains of the ESBL-positive E. coli and K. pneumoniae produced both DHA-1AmpC enzyme and CTX-M-3/SHV-12 ESBL. These 7 strains were from different clones.

Anti-Bacterial Agents↗

PubMed2004

[Two Ph chromosome positive chronic myelogenous leukemia patients with rare bcr/abl fusion gene].

OBJECTIVE: To investigate the unusual bcr/abl fusion gene structures of two Ph chromosome positive chronic myelogenous leukemia (CML) patients in chronic phase (CP). METHODS: By using general M- and micro -bcr/abl specific primers respectively, bcr/abl fusion transcripts were detected by reverse transcription-polymerase chain reaction (RT-PCR). The RT-PCR products sequencing was performed, the DNA sequences were analyzed in Genebank and the bcr and abl sequences at the fusion site were identified. DNA was amplified by PCR using a set of primers designed according to the sequencing result of RT-PCR products. RESULTS: Two patients showed typical manifestations of CML-CP. Their RT-PCR products were different from usual M- or micro -type; one was longer than M-bcr/abl but shorter than micro -bcr/abl, the other one was shorter than M-bcr/abl. The RT-PCR products sequencing showed that both products contained bcr and abl gene sequences. The first patient's bcr gene was broken within exon 18, and fused to abl gene exon 2(a2), and a 40 bp of partial abl intron 1b fragment was inserted between them, resulting in a novel in-frame bcr/abl fusion transcript-e18-int-a2 which has not been reported in the literature so far. In the second patient, deletion of abl exon2(a2) led to exon 13(b2) of bcr gene fusing with abl exon 3(a3). CONCLUSION: Uncommon bcr/abl fusion gene may occur in typical Ph(+) CML patient.

Adult↗

PubMed2004

[Changes of mitochondrial calcium, adenosine triphosphate and adenosine diphosphate contents induced by occlusal trauma in rabbit's masseter muscles].

OBJECTIVE: To study the role of Ca2+ overload and energy metabolism in mitochondria in masticatory muscle dysfunctional induced by occlusal trauma. METHODS: Mitochondrial Ca2+ contents were measured with atomic emission spectrophotometer. Mitochondrial ATP and ADP contents were measured with high performance liquid chromatography. RESULTS: (1) Mitochondrial Ca2+ contents of masseter muscle ipsilateral to metal splint in ten and twenty days' experimental groups and that contralateral to metal splint in twenty days' experimental group increased significantly (P < 0.05). (2) Mitochondrial ATP contents of masseter muscle ipsilateral to metal splint in experimental groups were higher than that in control groups and contralateral to metal splint after twenty days. (3) Mitochondrial Ca2+ contents of masseter muscle ipsilateral to metal splint were significantly negatively correlated to the mitochondrial ATP contents (r = -0.780, P < 0.05). CONCLUSION: Ca2+ overload in mitochondria depresses ATP production, which results in energy metabolism disorder in masticatory muscle cells. It may play an important role in the mechanism that occlusal trauma results in masticatory muscle dysfunction.

Adenosine Diphosphate↗

PubMed2004

[Expression of MCP-1 in airway of rats with COPD].

OBJECTIVE: To explore the role of monocyte chemoattractant protein-1 (MCP-1) in the pathogenesis of chronic obstructive plumonary disease (COPD). METHODS: Rat COPD model was established by exposing the rats to cigarette smoke daily. After COPD model was set up, bronchoalveolar lavage was performed. Total cell counts and alveolar macrophage (AM) counts in bronchoalveolar lavage fluid (BALF) were examined and the levels of MCP-1 and tumor necrosis factor-alpha (TNF-alpha) in BALF and serum were measured by ELISA. Lung tissue sections stained by HE were measured in terms of MLI, MAN and PAA by picture analysis system. RESULTS: MLI and PAA in COPD model were higher than those of control group while MAN was just on the contrary. Except MCP-1 levels in serum [(32.75 +/- 10.91) pg/ml vs (24.13 +/- 6.92) pg/ml, P>0.05], MCP-1 levels, TNF-alpha levels, total cell counts and AM counts in BALF of COPD model group were significantly higher than those of control group (P<0.01). Positive correlations were demonstrated among MCP-1 levels, TNF-alpha levels and AM counts in BALF in COPD group, but were not demonstrated between MCP-1 levels, TNF-alpha levels in serum and AM counts. CONCLUSION: There is a close correlation between MCP-1 in BALF and airway inflammation in COPD.

Animals↗

PubMed2004

[Effect of Ginkgo biloba L leaves on oxidation of human low density lipoproteins in vitro].

OBJECTIVE: To study the effects of Ginkgo biloba L leave on oxidation of human low density lipoproteins (LDL) induced by Fe2+ or Cu2+ in vitro. METHODS: LDL was oxidized by Fe2+ or Cu2+ for 1, 2, 4, 6h, while it was protected by extracts from leaves of Ginkgo biloba L. ( EGB761), ginkgo flavonids(GF) and ginkgo terpenlactones (GT). Lipofusion (LF), malondialdehyde (MDA) and vitamin E (VitE) were measured as the index of the oxidation of LDL by means of Fluorescence spectroscopy methods. RESULTS: Each extract can inhibit the oxidation of LDL, the inhibition of each extract is increasing during the first 4 hours and subsequently decrease, after 6 hours all the inhibitor have almost lost their ability on antioxidation. CONCLUSION: EGB761, GF and GT are effective antioxidant and the anti-oxidation vary with time.

Antioxidants↗

PubMed2004

[The effects of losartan on pulmonary arterial collagen and AT1 in chronic hypoxic rats].

OBJECTIVE: To investigate the effects of losartan on pulmonary arterial collagen and AT1 in chronic hypoxic rats. METHODS: Thirty male SD rats were randomly divided into three groups: control group, hypoxic group and therapeutic group. The animal model of pulmonary hypertension was established by exposing the rats to normabaric hypoxic conditions for three weeks. Then, the therapeutic group was given losartan for two weeks. We measured the expression of Collagen I, III and AT1 in arterioles by means of immunohistochemistry. RESULTS: The positive degree of Collagen I in pulmonary arterioles in the hypoxic group was higher than that in the control group [(1.5202+/-0.069) vs (1.1324+/-0.071), P<0.01]; but in the therapeutic group it was lower than that in the hypoxic group [(1.1637+/-0.062) vs (1.5202+/-0.069), P<0.01]. There was no significant difference in collagen III and AT1 among the three groups (P>0.05). CONCLUSION: Losartan could reduce pulmonary arterial collagen I expression, it may be one of the therapeutic mechanisms on hypoxic pulmonary hypertension of losartan.

Angiotensin II Type 1 Receptor Blockers↗

PubMed2004

[Relationship between the pathologic changes of human embryo fibroblast cells and expression of late mRNA after human cytomegalovirus infection in vitro].

OBJECTIVE: To study the relationship between late mRNA and the cytopathic effect(CPE) and ultrastructural features after human cytomegalovirus (HCMV) infection in vitro. METHODS: Human embryo fibroblast cells(HEL) were infected with HCMV AD169 strain. The expression of the HCMV late mRNA was measured by semiquantitative RT-PCR, the cytopathic effect (CPE) and the cell ultrastructure were observed by means of light microscopy and electron microscopy, respectively. RESULTS: The HCMV late mRNA could be detected 12 hours postinfection and increased gradually, but the CPE appeared 48 hours postinfection in HEL cells. The HCMV infected cells exhibited significant mitochondrial enlargement and the number of mitochondrial ridge deletion, the cisternae lumen of endoplasmic reticulum (ER) dilation and vacuolization (at the end age). The mature nucleocapsid could be observed 96 hours postinfection. CONCLUSION: The ultrastructural changes have an intimate correlation with the expression of HCMV late mRNA and play an important role in the life circle of the virus. HCMV late mRNA may serve as a indicator of the clinical effect of treatment in active HCMV infection.

Cytomegalovirus↗

PubMed2004

[Comparison study on inhibitory effect of extracts from leaves of Ginkgo biloba L. on the oxidation of human low density lipoproteins].

OBJECTIVE: To compare the effects of extracts from leaves of Ginkgo biloba L. (EGB761), ginkgo flavonoids (GF) and ginkgo terpenlactones (GT) on the oxidation of human plasma low density lipoproteins (LDL) induced by Fe2+ or Cu2+. METHOD: LDL was pretreated with EGB761, GF and GT, then was oxidized by CuSO4 or FeSO4 6 micromol/L for 4 h. Fluorescence Spectroscopy methods were adopted to determine the contents of lipofusion (LF), malondialdehyde (MDA) and vitamin E (VitE) of LDL oxidized by Fe2+ or Cu2+ and protected by EGB761, GF or GT. RESULT: After the oxidation of LDL induced by Fe2+ or Cu2+, VitE was exhausted, while MDA and LF were markedly increased. EGB761, GF and GT prevented the decrease of VitE and increases of MDA and LF in the ox-LDL. The inhibitory effect was GF > EGB761 > GT. CONCLUSION: GF played the main role in anti-oxidation.

Antioxidants↗

PubMed2004

[Synthetical evaluation of promoting effect of some kinds of transdermal enhancers with grey relational cluster method].

OBJECTIVE: Synthetical evaluation of promoting effect of some kinds of transdermal enhancers was carried through. METHOD: Diclofenac sodium was used as model, and azone and l-menthol and synthetic borneol and olieic acid and essential oil from Cnidium monnieri were used as transdermal enhancers. Transdermal absorption experimentation of diclofenac sodium on the device of penetrating skins in vitro was done. Cumulation of permeation amount and penetrating rates and steady fluxes and lag times were observed, and grey relational cluster method was used to evaluate the promoting effect of some kinds of transdermal enhancers. RESULT: As for promoting effect on diclofenac sodium, azone and l-menthol were the best, and synthetic borneol and olieic acid ranked behind. CONCLUSION: Grey relational cluster method can evaluate promoting effect objectively and fairly.

Administration, Cutaneous↗

PubMed2004

[Effect of shenwu capsule on the peripheral blood lymphocyte DNA of rat model induced by beta-amyloid injection].

OBJECTIVE: To investigate the effect of the new Traditional Chinese Compound Shenwu Capsule on the damage of lymphocyte DNA and lipid peroxidation in peripheral blood of rats induced by beta-amyloid injection. METHOD: The animal model was made by injection of beta-amyloid25-35 into hippocampus of rats. DNA damage of lymphocytes was measured by the single cell gel electrophoresis (SCGE) combined with the laser scanning confocal microscopy (LSCM). The content of malondialdehyde (MDA) was determined by TBA assay. RESULT: Shenwu Capsule decreased the rate of the comet-like cell, comet-like cell lengh (TCL), and tail moment (TM) of lymphocytes in peripheral blood of model rats. Shenwu Capsule also declined the MDA content in serum of Abeta model rats. CONCLUSION: Shenwu Capsule has protective effect on peripheral blood lymphocyte DNA.

Amyloid beta-Peptides↗

PubMed2004

[Growth inhibitory effect of adriamycin conjugated to single-chain antibody on human lung adenocarcinoma in vitro].

OBJECTIVE: To evaluate the growth inhibitory effect of adriamycin (ADM) conjugated to an anti-lung cancer single-chain antibody (ScFv) 2A7-1 on lung adenocarcinoma cell line A2 in vitro. METHODS: 2A7-1 cell culture medium was concentrated by ultra-filtration (with Amicon P10Z filter), and soluble ScFv was purified using RPAS purification kit. ADM was conjugated to 2A7-1 by glutaraldehyde. A(280) and A(490) of the conjugate 2A7-1-ADM were determined by spectrophotometry and the molar ratio of 2A7-1 to ADM was calculated. Immunoreactivity of the conjugate was detected by immunohistochemistry. Its growth inhibitory effect on lung adenocarcinoma cell line A2 was determined by colony formation assay in vitro. RESULTS: The molar ratio of 2A7-1 to ADM was 1:3.2. The conjugate strongly reacted with A2 cell. Its growth inhibitory effect on A2 cells was 4 times as potent as ADM. CONCLUSION: Adriamycin conjugated to anti-lung cancer single-chain antibody 2A7-1 has much higher cytotoxic activity than unconjugated adriamycin against human lung adenocarcinoma.

Adenocarcinoma↗

PubMed2004

[Determination of 14 trace elements in soybean and its products by atomic absorption spectrometry].

Fourteen trace elements in soybean and its products were determined by atomic absorption spectrometry. The effects of cinefaction temperature, cinefaction time, and the concentration of HNO3 as a digestion solution were investigated in detail. The effect of the concentration of SrCl2 on the determination of Ca and Mg was also studied. The results obtained show that the soybean and its products contain higher amounts of K, Na, Ca, Mg, Fe, Cu, Zn and Mn than other elements.

Animals↗

PubMed2004

[Modification and high level expression of protective antigen fragment of botulinum neurotoxin serotype A].

Designed a pair of primers through modifying N-terminal bases (5bps) of gene after ATG but not changing amino acid, and amplified a smaller mutated gene sequnce (468bp) containing two protective antigenic determinants from pBlue-BoNTaHc, N-terminal codon of mutated gene fragment is changed from low to high frenqence in E. coli. Mutated gene was ligated into pGEM-T vector and sequenced, then, cloned into a expression plasmid pBV220. As a result, cloned gene was expressed in insoluble form by temperature inducing (from 30 degrees C to 42 degrees C) in E. coli. Expression product is 40% of total proteins and is of specific binding activity to antibody in ELISA. The successful modification and high level expression of protective fragment of botulinum neurotoxin serotype A(BoNTaHc468) gene is conducive to further study on antitoxin and vaccine.

Bacterial Vaccines↗

PubMed2004

[Preparation of alpha-toxin's protective antigen of clostridium perfringens type A and research for its primary immunological protective function].

Induced by 42 degrees C, the recombinant engineering bacterial pBV/cpa408 was highly expressed. After having been pelleted by 80% (NH4)2 SO4 and dialysised, the expressed protein was isolated and purified by the gel filtration choromatography. Then according to an amount of 1.0 mg/kg, the Kunming Mice (body weighted 18g) were immuned with the purified protein by intraperitoneal inoculation. One week after the first enhanced immunization, the Kunming Mice were attacked with an amount of 1.0MLD alpha-toxin, in which the eight mice immuned all survive and the control group all died. During the period of immunization, the titre of the mouse's serum antibody was measured by ELISA. One week after the first immunization, the titre of the mice's serum antibody was 1:800, but that of one week after the first enhanced immunization reached to 1:6400.

Animals↗

PubMed2004

[Morphologic and physiochemical properties of bovine jugular conduit stabilized by dye-mediated poto-oxidation].

OBJECTIVE: To determine the morphologic and physiochemical properties of bovine jugular conduit with valves stabilized by dye-mediated photo-oxidation. METHODS: Twenty-four bovine jugular conduits with valves were divided into 3 groups and treated with dye-mediated photo-oxidation (Group I), glutaraldehyde (Group II) and untreated group (Group II), respectively. Morphologic and physiochemical properties of the 3 groups, including wall thickness, diameter, tissue water content, heat shrinking temperature, breaching strength, and tissue protein extraction assay were studied. RESULTS: There was no difference in wall thickness, diameter, tissue water content, and heat shrinking temperature between Group I and II ,but there was significant difference between Group I and II. The breaching strength of Group I was higher than that of Group IU (P < 0.05), but lower than that of Group II (P < 0. 05). A decrease in extractable tissue protein was found in Group I and II. CONCLUSION: The dye-mediated photooxidation can effectively preserve the structure and the anti-regurgitation function of valves and improve the tissue stability and enhance the tension of bovine jugular conduit with valves.

Animals↗

PubMed2003

Adenosine kinase is inactivated by geminivirus AL2 and L2 proteins.

AL2 and L2 are related proteins encoded by geminiviruses of the Begomovirus and Curtovirus genera, respectively. Both are pathogenicity determinants that cause enhanced susceptibility when expressed in transgenic plants. To understand how geminiviruses defeat host mechanisms that limit infectivity, we searched for cellular proteins that interact with AL2 and L2. Here, we present evidence that the viral proteins interact with and inactivate adenosine kinase (ADK), a nucleoside kinase that catalyzes the salvage synthesis of 5'-AMP from adenosine and ATP. We show that the AL2 and L2 proteins inactivate ADK in vitro and after coexpression in Escherichia coli and yeast. We also demonstrate that ADK activity is reduced in transgenic plants expressing the viral proteins and in geminivirus-infected plant tissues. By contrast, ADK activity is increased after inoculation of plants with diverse RNA viruses or a geminivirus lacking a functional L2 gene. Consistent with its ability to interact with multiple cellular kinases, we also demonstrate that AL2 is present in both the nucleus and the cytoplasm of infected plant cells. These data indicate that ADK is targeted by viral pathogens and provide evidence that this "housekeeping" enzyme might be a part of host defense responses. In previous work, we showed that AL2 and L2 also interact with and inactivate SNF1 kinase, a global regulator of metabolism that is activated by 5'-AMP. Together, these observations suggest that metabolic alterations mediated by SNF1 are an important component of innate antiviral defenses and that the inactivation of ADK and SNF1 by the geminivirus proteins represents a dual strategy to counter this defense. AL2 proteins also have been shown to act as suppressors of RNA silencing, an adaptive host defense response. A possible relationship between ADK inactivation and silencing suppression is discussed.

Adenosine Kinase↗

PubMed2003

Sonochemical fabrication and characterization of stibnite nanorods.

Regular stibnite (Sb(2)S(3)) nanorods with diameters of 20-40 nm and lengths of 220-350 nm have been successfully synthesized by a sonochemical method under ambient air from an ethanolic solution containing antimony trichloride and thioacetamide. The as-prepared Sb(2)S(3) nanorods are characterized by employing techniques including X-ray powder diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, transmission electron microscopy, selected area electron diffraction, high-resolution transmission electron microscopy, and optical diffuse reflection spectroscopy. Microstructural analysis reveals that the Sb(2)S(3) nanorods crystallize in an orthorhombic structure and predominantly grow along the (001) crystalline plane. High-intensity ultrasound irradiation plays an important role in the formation of these Sb(2)S(3) nanorods. The experimental results show that the sonochemical formation of stibnite nanorods can be divided into four steps in sequence: (1) ultrasound-induced decomposition of the precursor, which leads to the formation of amorphous Sb(2)S(3) nanospheres; (2) ultrasound-induced crystallization of these amorphous nanospheres and generation of nanocrystalline irregular short rods; (3) a crystal growth process, giving rise to the formation of regular needle-shaped nanowhiskers; (4) surface corrosion and fragmentation of the nanowhiskers by ultrasound irradiation, resulting in the formation of regular nanorods. The optical properties of the Sb(2)S(3) amorphous nanospheres, irregular short nanorods, needle-shaped nanowhiskers, and regular nanorods are investigated by diffuse reflection spectroscopic measurements, and the band gaps are measured to be 2.45, 1.99, 1.85, and 1.94 eV, respectively.

Journal Article↗

PubMed2003

Antisense therapy targeting MDM2 oncogene in prostate cancer: Effects on proliferation, apoptosis, multiple gene expression, and chemotherapy.

This study was undertaken to investigate the role of mouse double minute 2 (MDM2) oncogene in prostate cancer growth and the potential of MDM2 as a target for prostate cancer therapy. An antisense anti-human-MDM2 mixed-backbone oligonucleotide was tested in human prostate cancer models with various p53 statuses, LNCaP (p53wt/wt), DU145 (p53mt/mt), and PC3 (p53null). In a dose- and time-dependent manner, it specifically inhibited MDM2 expression and modified expression of several genes, at both mRNA and protein levels. In LNCaP cells, p53, p21, Bax, and hypophosphorylated retinoblastoma tumor suppressor protein (pRb) levels increased, whereas Bcl2, pRb protein, and E2F transcription factor 1 (E2F1) levels decreased. In DU145 cells, p21 levels were elevated and E2F1 levels decreased, although mutant p53, Rb, and Bax levels remained unchanged. In PC3 cells, MDM2 inhibition resulted in elevated p21, Bax, and pRb levels and decreased ppRb and E2F1 levels. In all three cell lines, MDM2 inhibition reduced cell proliferation, induced apoptosis, and potentiated the effects of the chemotherapeutic agents 10-hydroxycamptothecin and paclitaxel. The anti-MDM2 oligonucleotide showed antitumor activity and increased therapeutic effectiveness of paclitaxel in both LNCaP and PC3 xenografts, causing changes in gene expression similar to those seen in vitro. In summary, this study demonstrates that MDM2 has a role in prostate cancer growth via p53-dependent and p53-independent mechanisms and that multiple genes are involved in the process. MDM2 inhibitors such as second-generation antisense oligonucleotides have a broad spectrum of antitumor activities in human cancers regardless of p53 status, providing novel approaches to therapy of human prostate cancer.

Apoptosis↗