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Biomedical subjects

Li Wang

Publications and source records attributed to Li Wang.

At least 145 records · Page 8Linked to original sources
PubMed2006

Removal of algae by sonication-coagulation.

Algae bloom in source water has caused serious problems in drinking water supplies, and conventional methods for its treatment have achieved only limited success. This paper reports a new technology, ultrasound assisted coagulation, for effective removal of algae cells from the source water in water treatment works. The results showed that ultrasonic pretreatment significantly enhanced the removal efficiency of algae cells. Ultrasonic irradiation for 5 s increased the algae removal efficiency by more than 20% when the coagulant dose was 0.4-0.8 mg/L. To achieve the same algae removal ratio of 90%, sonication for 5 s reduced the coagulant dose by 2/3. The optimal sonication parameters were determined as follows: sonication time of 1 s, ultrasonic power of 48 W, and solution pH of 8-9. The sound frequency had little impact on the algal removal efficiency. Ultrasonic pretreatment also significantly reduced the sample turbidity.

Cyanobacteria↗
PubMed2006

Regulation of matrix metalloproteinase production and tumor cell invasion by four monoclonal antibodies against different epitopes of HAb18G/CD147 extracellular domain.

HAb18G/CD147, a membrane spanning molecule and highly expressed in hepatocellular carcinoma (HCC) cells, was shown to stimulate the production of matrix metalloproteinases (MMPs) in the interaction of tumor cells and fibroblasts. Studies on the EMMPRIN/CD147 showed that CD147 extracellular domain is involved in the induction of MMPs. To study the biological molecular function of HAb18G/CD147 extracellular domain (HAb18G/CD147-ED) on production of MMPs following mediated tumor cell invasion, we isolated four novel monoclonal anibodies (MAbs)-1B3, 3B3, HAb18Gedomab1, and HAb18Gedomab2-against HAb18G/CD147-ED by immunization of BALB/c mice with purified HAb18G/CD147-ED fragments, which were efficiently expressed in Escherichia coli. Gelatin zymography and Boyden chamber assays were used to identify the production of MMPs in the co-cultured human fibroblast and HCC cells, and to quantify the migrated cells in the presence of the generated MAbs. The results showed that two MAbs (1B3 and 3B3) inhibited [corrected] the secretion of MMP-2 and [corrected] the HCC cell invasion, whereas the other two MAbs (HAb18Gedomab1 and HAb18Gedomab2) had reverse function [corrected] FCM additive assay showed that four MAbs recognized different epitopes of HAb18G/CD147-ED. Taken together, the results suggest that various regions of HAb18G/CD147-ED participated in the regulation of MMP secretion.

Animals↗
PubMed2006

In vitro effects of recombinant zebrafish IFN on spring viremia of carp virus and infectious hematopoietic necrosis virus.

In order to evaluate the effects of fish recombinant interferon (rIFN) on fish pathogenic rhabdoviruses, the zebrafish (Danio rerio) IFN (DreIFN) allele B gene was cloned and expressed in Escherichia coli. In addition, the effects of recombinant DreIFN (rDreIFN) on spring viremia of carp virus (SVCV), infectious hematopoietic necrosis virus (IHNV), and vesicular stomatitis virus (VSV) were surveyed in fish and chicken cells. The mature peptide of DreIFN allele B gene encodes 163 amino acids. Residues 3 and 98 are a pair of cysteines that likely form an intrachain disulfide bridge. rDreIFN protein was detected as a band at 21.6 kDa by SDS-PAGE. The purified rDreIFN has anti-SVCV and anti-IHNV activity of 3 x 10(4) U/mg-10(7) U/mg. The results indicate that rDreIFN has higher activity against SVCV and IHNV on epithelioma papulosum cyprinid (EPC) than on grass carp (C. idellus) ovary (CO) cell lines and no activity against VSV on chick embryo fibroblasts (CEF).

Amino Acid Sequence↗
PubMed2006

Pseudomonas syringae effector avrB confers soybean cultivar-specific avirulence on Soybean mosaic virus adapted for transgene expression but effector avrPto does not.

Soybean mosaic virus (SMV) was adapted for transgene expression in soybean and used to examine the function of avirulence genes avrB and avrPto of Pseudomonas syringae pvs. glycinea and tomato, respectively. A cloning site was introduced between the P1 and HC-Pro genes in 35S-driven infectious cDNAs of strains SMV-N and SMV-G7. Insertion of the uidA gene or the green fluorescent protein gene into either modified cDNA and bombardment into primary leaves resulted in systemic expression that reflected the pattern of viral movement into uninoculated leaves. Insertion of avrB blocked symptom development and detectable viral movement in cv. Harosoy, which carries the Rpg1-b resistance gene corresponding to avrB, but not in cvs. Keburi or Hurrelbrink, which lack Rpg1-b. In Keburi and Hurrelbrink, symptoms caused by SMV carrying avrB appeared more quickly and were more severe than those caused by the virus without avrB. Insertion of avrPto enhanced symptoms in Harosoy, Hurrelbrink, and Keburi. This result was unexpected because avrPto was reported to confer avirulence on P. syringae pv. glycinea inoculated to Harosoy. We inoculated Harosoy with P syringae pv. glycinea expressing avrPto, but observed no hypersensitive reaction, avrPto-dependent induction of pathogenesis-related protein la, or limitation of bacterial population growth. In Hurrelbrink, avrPto enhanced bacterial multiplication and exacerbated symptoms. Our results establish SMV as an expression vector for soybean. They demonstrate that resistance triggered by avrB is effective against SMV, and that avrB and avrPto have general virulence effects in soybean. The results also led to a reevaluation of the reported avirulence activity of avrPto in this plant.

Bacterial Proteins↗
PubMed2006

Comparison of minimum alveolar concentration between intravenous isoflurane lipid emulsion and inhaled isoflurane in dogs.

BACKGROUND: As in inhaled isoflurane anesthesia, when isoflurane lipid emulsion (ILE; 8%, vol/vol) is intravenously administered, the primary elimination route is through the lungs. This study was designed to determine the minimum alveolar concentration (MAC) and the time course of washout of isoflurane for intravenously infused ILE by monitoring end-tidal isoflurane concentration. METHODS: Twelve healthy adult mongrel dogs were assigned randomly to an intravenous anesthesia group with 8% ILE or to an inhalation anesthesia group with isoflurane vapor. An up-and-down method and stimulation of tail clamping were used to determine MAC of 8% ILE by intravenous injection in the intravenous anesthesia group and MAC by the inhaled approach in the inhalation anesthesia group, respectively. Isoflurane concentration and partial pressure in end-tidal gas, femoral arterial blood, and jugular venous blood were measured simultaneously just before each tail clamping and during washout. RESULTS: The induction time in the intravenous anesthesia group (105 +/- 24 s) was shorter than that in the inhalation anesthesia group (378 +/- 102 s; P < 0.01). MAC of 8% ILE by intravenous injection (1.12 +/- 0.18%) was significantly less than MAC by the inhaled approach (1.38 +/- 0.16%; P < 0.05). No significant difference was found between the two groups in the time course of washout of isoflurane. CONCLUSION: The MAC of intravenous anesthesia with 8% ILE was less than that of inhalation anesthesia with isoflurane vapor in dogs.

Administration, Inhalation↗
PubMed2006

Influence of angiogenin on the growth of A375 human melanoma cells and the expression of basic fibroblast growth factor.

Angiogenin was isolated as a tumor angiogenic factor solely on the basis of its angiogenic activity. Its expression is essential for melanoma progression and metastasis. Many studies have mainly focused on how it induces angiogenesis, which allows further melanoma growth and metastasis. Here, we investigated the effects of angiogenin on melanoma cell growth and studied its influence on the expression and function of the basic fibroblast growth factor. We transfected the angiogenin gene in the sense and antisense orientation into A375 cells, and obtained stable angiogenin under-expressing and over-expressing transfectants. We found that in the angiogenin antisense transfectants, the cell proliferation was decreased and the basic fibroblast growth factor-induced cell proliferation was inhibited, but the expression of basic fibroblast growth factor was increased. In contrast, in the angiogenin sense transfectants, the cell proliferation was increased, and the basic fibroblast growth factor-induced cell proliferation was also increased. The expression of basic fibroblast growth factor, however, was decreased. In conclusion, we demonstrated that, besides its angiogenic activity, angiogenin also directly contributes to A375 cell proliferation and is required for the basic fibroblast growth factor to induce cell proliferation. We also demonstrated that the endogenous angiogenin expression levels affect the expression of basic fibroblast growth factor in A375 cells. By targeting angiogenin, therefore, one may find a potential therapeutic approach to human malignant melanoma.

Angiogenesis Inducing Agents↗
PubMed2006

Protective effects of EUK4010 on beta-amyloid(1-42) induced degeneration of neuronal cells.

EUK4010 has been identified to exhibit an inhibitory effect on beta-amyloid (Abeta)(1-42)-induced loss of neuronal cell viability. Further studies demonstrated that EUK4010 attenuated the Abeta(1-42)-induced degeneration in both cultured rat hippocampal neurons and human neuroblastoma cells, as demonstrated by typical morphological changes, cell viability and the chip-based flow cytometric assay. Gene expression analysis using DNA microarray showed that the senescence marker calcium-binding protein, regucalcin (Rgn), GABA-A receptor pi subunit (Gabrp), the huntingtin binding protein, optineurin (Optn) and a semaphorin family plexin A3 similar protein (Plex-similar) changed their expression levels significantly in cultured neurons after Abeta(1-42) treatment. In this report, we have undertaken a chemical genetic approach to study the molecular basis of Abeta(1-42) effects on the neuronal degeneration. Our results demonstrate that EUK4010 completely blocked the Abeta(1-42)-induced up-regulation of GABA-A receptor pi subunit and the semaphorin family plexin A3 similar protein, and partially attenuated the down-regulation of senescence marker calcium-binding protein, regucalcin. These observations suggest that EUK4010 may prevent or reduce the Abeta toxicity by regulating the expression of genes involved in the Abeta induced neuronal degeneration. These genes may represent a promising target for the therapeutic drug development for Alzheimer's disease (AD) and other neurological disorders. Furthermore, EUK4010 and its analogues could potentially be developed as neuronal protective agents for the treatment of these diseases.

Amyloid beta-Peptides↗
PubMed2006

Glandular odontogenic cyst in China: report of 12 cases and immunohistochemical study.

OBJECTIVE: The purpose of this study was to present 12 additional cases of glandular odontogenic cyst (GOC) in the Department of Oral Pathology, School of Stomatology, Wuhan University, People's Republic of China, and to investigate their immunohistochemical cytokeratins (CKs) expression in the epithelial components. METHODS: A total of 12 GOCs were reviewed clinically and radiographically, and immunohistologic CKs AE1, 7, 8/18, 10/13, 14, 16, 19 and 20 were performed by using a standard biotin-streptavidin immunoperoxidase technique on paraffin sections. RESULTS: The present series showed that eight occurred in males and four in females. The mean age was 37.6 years with a peak incidence occurring in the third decades (six of 12). Mandibles were more affected than maxillas (7:5), especially anterior mandible (four of seven). Radiographically, ratio multilocular to unilocular radiolucencies was 5:7 usually with well-defined borders. Histologically, cystic spaces were lined by non-keratinized stratified epithelia containing focal plaque-like or whirlpool-like thickenings; surface epithelial layer-containing eosinophilic cuboidal cells; mucous cells; and mucin pools of microcystic areas in the epithelium. Immunohistochemistry showed that epithelium of GOCs stained for CKs AE1, 7, 8/18, 10/13, 14 and 19 with slight changes in their patterns, and no reaction to CKs 16 and 20. CONCLUSIONS: Most clinical and histologic features in this study were analogous to those reported west population, although with slight difference between them. Histologically, the morphology of the epithelium strongly suggested an odontogenic origin, and CKs expression of GOC was similar to that of odontogenic epithelium, suggesting histochemically that GOC might be derived from odontogenic epithelium.

Adult↗
PubMed2006

Vascular basement membrane-derived multifunctional peptide, a novel inhibitor of angiogenesis and tumor growth.

Vascular basement membrane-derived multifunctional peptide (VBMDMP) gene (fusion gene of the human immunoglobulin G3 upper hinge region and two tumstatin-derived fragments) obtained by chemical synthesis was cloned into vector pUC19, and introduced into the expression vector pGEX-4T-1 to construct a prokaryotic expression vector pGEX-4T-1-VBMDMP. Recombinant VBMDMP produced in Escherichia coli has been shown to have significant activity of antitumor growth and antimetastasis in Lewis lung carcinoma transplanted into mouse C57Bl/6. In the present study, we have studied the ability of rVBMDMP to inhibit endothelial cell tube formation and proliferation, to induce apoptosis in vitro, and to suppress tumor growth in vivo. The experimental results showed that rVBMDMP potently inhibited proliferation of human endothelial (HUVEC-12) cells and human colon cancer (SW480) cells in vitro, with no inhibition of proliferation in Chinese hamster ovary (CHO-K1) cells. rVBMDMP also significantly inhibited human endothelial cell tube formation and suppressed tumor growth of SW480 cells in a mouse xenograft model. These results suggest that rVBMDMP is a powerful therapeutic agent for suppressing angiogenesis and tumor growth.

Angiogenesis Inhibitors↗
PubMed2006

A lithium-sensitive and sodium-tolerant 3'-phosphoadenosine-5'-phosphatase encoded by halA from the cyanobacterium Arthrospira platensis is closely related to its counterparts from yeasts and plants.

3'-Phosphoadenosine-5'-phosphatase (PAPase) is required for the removal of toxic 3'-phosphoadenosine-5'-phosphate (PAP) produced during sulfur assimilation in various eukaryotic organisms. This enzyme is a well-known target of lithium and sodium toxicity and has been used for the production of salt-resistant transgenic plants. In addition, PAPase has also been proposed as a target in the treatment of manic-depressive patients. One gene, halA, which could encode a protein closely related to the PAPases of yeasts and plants, was identified from the cyanobacterium Arthrospira (Spirulina) platensis. Phylogenic analysis indicated that proteins related to PAPases from several cyanobacteria were found in different clades, suggesting multiple origins of PAPases in cyanobacteria. The HalA polypeptide from A. platensis was overproduced in Escherichia coli and used for the characterization of its biochemical properties. HalA was dependent on Mg2+ for its activity and could use PAP or 3'-phosphoadenosine-5'-phosphosulfate as a substrate. HalA is sensitive to Li+ (50% inhibitory concentration [IC50] = 3.6 mM) but only slightly sensitive to Na+ (IC50 = 600 mM). The salt sensitivity of HalA was thus different from that of most of its eukaryotic counterparts, which are much more sensitive to both Li+ and Na+, but was comparable to the PAPase AtAHL (Hal2p-like protein) from Arabidopsis thaliana. The properties of HalA could help us to understand the structure-function relationship underlying the salt sensitivity of PAPases. The expression of halA improved the Li+ tolerance of E. coli, suggesting that the sulfur-assimilating pathway is a likely target of salt toxicity in bacteria as well.

Adenosine Diphosphate↗
PubMed2006

A pair of iron-responsive genes encoding protein kinases with a Ser/Thr kinase domain and a His kinase domain are regulated by NtcA in the Cyanobacterium Anabaena sp. strain PCC 7120.

The filamentous cyanobacterium Anabaena sp. strain PCC 7120 can fix N(2) when combined nitrogen is not available in the growth medium. It has a family of 13 genes encoding proteins with both a Ser/Thr kinase domain and a His kinase domain. The function of these enzymes is unknown. Two of them are encoded by pkn41 (alr0709) and pkn42 (alr0710). These two genes are separated by only 72 bp on the chromosome, and our results indicate that they are cotranscribed. The expression of pkn41 and pkn42 is induced by iron deprivation irrespective of the nature of the nitrogen source. Mutants inactivating either pkn41, pkn42, or both grow similarly to the wild type under normal conditions, but their growth is impaired either in the presence of an iron chelator or under conditions of nitrogen fixation and iron limitation, two situations where the demand for iron is particularly strong. Consistent with these results, these mutants display lower iron content than the wild type and a higher level of expression for nifJ1 and nifJ2, which encode pyruvate:ferredoxin oxidoreductases. Both nifJ1 and nifJ2 are known to be induced by iron limitation. NtcA, a global regulatory factor for different metabolic pathways, binds to the putative promoter region of pkn41, and the induction of pkn41 in response to iron limitation no longer occurs in an ntcA mutant. Our results suggest that ntcA not only regulates the expression of genes involved in nitrogen and carbon metabolism but also coordinates iron acquisition and nitrogen metabolism by activating the expression of pkn41 and pkn42.

Anabaena↗
PubMed2006

[Clinical experience of treatment of 275 mandible fractures].

OBJECTIVE: To evaluate the treatment effect of mandible fractures. METHODS: Clinical data of 275 mandibular fracture patients of Tongchuan people's hospital were analysed. RESULTS: (1) The systemic health of 27 non-surgery cases were influenced during the intermaxillary ligation and 3 cases of them had deformity of maxillofacial region. (2) In the surgery group, 5 of 73 cases fixed by steel wire had disorder of occlusion, 6 of 169 cases fixed by titanium mini plate accepted secondary operation of removing the plates, and 6 cases fixed by bioabsorbable mini plate had better effect. CONCLUSION: The internal rigid fixation is an appropriate and effective method for the mandible fractures.

Bone Plates↗
PubMed2006

[A clinical analysis of intractable spontaneous epistaxis with 289 cases reviewed].

OBJECTIVE: To explore the clinical characteristics and the prevention strategy of intractable spontaneous epistaxis. METHOD: Two hundred and eighty-nine patients with intractable spontaneous epistaxis were retrospectively analyzed. RESULT: Intractable spontaneous epistaxis was characterized by the onset season, age, sex, and the associated disease. Nasal septums were the most common sites of bleeding. Recurrent epistaxis was mainly associated with the failure of locating the bleeding sites. CONCLUSION: Control of elevated blood pressure is essential for the prevention of intractable spontaneous epistaxis. Once epistaxis occurs, the importance of the first treatment for the haemostasis should be emphasized. For the uncontrollable epistaxis, multiple interventions are necessary.

Adolescent↗
PubMed2006

[Myopia and genetics].

The physiological manifestation of myopia is error of refraction. The incidence of myopia in Asian population is increasing much more rapidly compared with several decades ago. Most of the people in the relatively developed Chinese cities are developing or have developed myopia. Recently, researches reported six loci related to myopia. Viewing from the modern civilization and development of China, the sharp increase of the size of the population with myopia and the unbalanced change could not be explained only by gene mutation or any model of Mendelian inheritance. The comparison of the disparity of the economic and educational levels between in urban and rural areas showed that the onset of myopia might be influenced by both environmental and genetic factors. Special attention should be paid to myopia now to prevent severe physical problem in the Chinese urban population.

China↗
PubMed2006

[Prognostic value of N-terminal-pro-brain natriuretic peptide on admission in patients with chronic heart failure].

OBJECTIVE: Heart failure is responsible for a huge burden in hospital care. Our goal was to evaluate the value of N-terminal-pro-brain natriuretic peptide (Nt-proBNP) on predicting death or hospital readmission after hospital discharge in patients with chronic heart failure (CHF). METHODS: From March 2003 to April 2005, 135 consecutive patients (97 male and 38 female, mean age 60.7 years +/- 13.1 years) with chronic heart failure [dilated cardiomyopathy (44%) and coronary heart disease (35%)] were included in this study. Plasma concentrations of the Nt-proBNP were measured by ELISA on admission. All patients received conventional therapy and were followed up for 24 months. The primary end point was death or readmission. RESULTS: (1) During the follow up period (640 days +/- 100 days), 11 patients died and 39 patients rehospitalized, the median Nt-proBNP level on admission was significantly higher in patients died during the follow up period (5908 ng/L) than that of rehospitalized patients (2768 ng/L, P = 0.038). Plasma Nt-proBNP level on admission were significantly higher in primary end point group (n = 50, 2947 ng/L) than that in non-primary end point group (n = 85, 917 ng/L, P < 0.01). (2) Variables associated with an increased hazard of death and/or rehospitalization were Nt-proBNP and NYHA degree when analyzed by logistic regression models. Increased Log Nt-proBNP was the strongest independent predictor of an adverse outcome of CHF (odds ratio 13.8, 95% confidence interval 2.29 to 2.78, P < 0.01). (3) Area under the curve for Nt-proBNP in evaluating prognosis of CHF patients was 0.885 (positive predictive value 88.5%, negative predictive value 11.5%). CONCLUSION: Nt-proBNP level on admission is a strong predictor of rehospitalization and death within 24 months after hospital discharge in patients with chronic heart failure.

Adolescent↗
PubMed2006

[Gene transfer of CD151 enhanced myocardial angiogenesis and improved cardiac function in rats with experimental myocardial infarction].

OBJECTIVE: To investigate the effects of in vivo CD151 gene transfer on angiogenesis and heart function in rats with myocardial infarction. METHODS: Acute myocardial infarction (AMI) was induced in male Sprague-Dawley (SD) rats by left anterior descending coronary artery ligation. The surviving rats randomly received myocardial injection of saline (MI control), pAAV-CD151 and pAAV-GFP (n = 12/group). Sham-operated rats without myocardial injection (n = 12) were taken as normal control. Four weeks later, heart function and the expression of CD151 were measured. Micro vessels density (MVD) in infarct myocardium was observed by factor VIII related antigen immunochemical staining. RESULTS: The expression of CD151 (1.98 +/- 0.23 vs. 0.91 +/- 0.09, P < 0.01) and MVD counting [(385.4 +/- 79.9) vs. (252.5 +/- 43.0) n/mm(2), P < 0.01] in pAAV-CD151 treated MI rats were significantly higher than that in MI control group, similarly, EF (64.0 +/- 8.7)% vs. (41.5 +/- 5.0)%, P < 0.01] and dp/dt(max) (6620.2 +/- 884.6 vs. 5545.5 +/- 693.0, P < 0.01) were also significantly increased post pAAV-CD151 treatment. These parameters were not affected by pAAV-GFP treatment. CONCLUSION: CD151 in vivo gene transfer for rats with acute myocardial infarction enhanced myocardial angiogenesis and improved left ventricular function.

Animals↗
PubMed2006

[The effect of basic fibroblast growth factor and epidermal growth factor on corneal endothelial cells preserved in mid-term preserving medium].

OBJECTIVE: To investigate the effect of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) on corneal endothelial cell preserved in mid-term preserving medium. METHOD: Corneal rings were preserved in mid-term preserving medium in control group. bFGF (5 ng/ml), bFGF (20 ng/ml), EGF and bFGF + EGF were added into the mid-term preserving medium in experimental groups A, B, C, D respectively. At the 3rd, 7th and 14th day after preservation, the viability of corneal endothelial cells (CECs) was assessed by trypan blue and alizarin red stain. The microstructure of corneal endothelial cells was observed by electron microscope (EM). RESULTS: At the 14th days of preservation, viability of CECs was (10.35 +/- 1.32)% (control group), (62.18 +/- 1.56)% (group A), (92.57 +/- 0.90)% (group B), (71.01 +/- 2.67)% (group C) and (82.59 +/- 1.45)% in group D respectively. The viability of CECs in experimental groups was much higher than in control group (P < 0.01). At the 14th days, corneal rings in control group showed edematous, cloud, defect of integrity of endothelial cells and Y type conjunction broken. But in experimental groups, the corneal edema and folds were slightly, furthermore the cornea ring was transparency and cell shape was intact, especially in group B and group D. Electronic microscope (EM) showed that corneal endothelial cells Y type conjunction in experimental groups was completely integrity, endothelial cells had tight conjunction and rich micro-villa on surface, large cells body and obvious nucleus. CONCLUSION: Addition of bFGF and EGF in corneal storage medium plays a significant role in maintaining CECs structure and viability.

Drug Synergism↗