Biomedical subjects

Gang Wang

Publications and source records attributed to Gang Wang.

At least 55 records · Page 3Linked to original sources

PubMed2006

An ESS for the height of a plant population, or an optimal height for an individual?--Rethinking game-theoretic models for plant height.

Plants only interact with neighbors over restricted distances, so local conditions are of great significance for plants. It is therefore important to consider spatial structure and neighborhood effects if we are to understand plants' strategies. We constructed a spatially-explicit, game theory model to explore optimal height growth at the individual-level. In the model, there is no ESS for height growth at the population level, because there is an "instantaneous" optimal height growth strategy for the individual plant that changes depending on the local light environment. The optimal strategy is plasticity in response to local conditions. Game-theoretic models for plant phenotypic traits should move from "mean-field approximations" towards explicit modeling of local interactions.

Ecosystem↗

PubMed2006

[The effect of combination of glycine and methylprednisolone on Kupffer cells of liver after hemorrhagic shock in rats].

OBJECTIVE: To investigate the effect of combination of glycine and methylprednisolone (MP) on Kupffer cells in liver of rats suffered from hemorrhagic shock. METHODS: Fifty Wistar rats were bled to establish the shock model and subsequently resuscitated with shed blood and normal saline. Just prior to resuscitation, the rats were randomly assigned to 5 groups: sham group, shock group, shock + glycine group, shock + MP group and shock + glycine + MP group. The intracellular calcium concentration and the level of tumor necrosis factor alpha (TNF alpha) in the culture medium of Kupffer cells were determined after stimulation with different concentrations (1, 10, 100 and 1000 ng/ml) of lipopolysaccharide (LPS). RESULTS: Concentration of intracellular calcium and production of TNF-alpha by isolated Kupffer cells stimulated by LPS were elevated significantly in the rats with hemorrhagic shock, which were totally prevented by glycine + MP compared with other groups (P < 0.005). CONCLUSIONS: The combination of glycine and MP prevents the increase of intracellular calcium of Kupffer cell, suppress Kupffer cell activation, decrease the production of TNF-alpha of Kupffer cell and block systemic inflammatory responses more effectively than single administer of glycine or MP.

Animals↗

PubMed2006

Identification of differently expressed genes in human colorectal adenocarcinoma.

AIM: To investigate the differently expressed genes in human colorectal adenocarcinoma. METHODS: The integrated approach for gene expression profiling that couples suppression subtractive hybridization, high-throughput cDNA array, sequencing, bioinformatics analysis, and reverse transcriptase real-time quantitative polymerase chain reaction (PCR) was carried out. A set of cDNA clones including 1260 SSH inserts amplified by PCR was arrayed using robotic printing. The cDNA arrays were hybridized with fluorescent-labeled probes prepared from RNA of human colorectal adenocarcinoma (HCRAC) and normal colorectal tissues. RESULTS: A total of 86 genes were identified, 16 unknown genes and 70 known genes. The transcription factor Somult9 influencing cell differentiation was downregulated. At the same time, Heat shock protein 10 KDis downregulated and Calmoulin is up-regulated. CONCLUSION: Downregulation of heat shock protein 10 KD lost its inhibition of Ras, and then attenuated the Ras GTPase signaling pathway, increased cell proliferation and inhibited cell apoptosis. Down-regulated transcription factor Somult9 influences cell differentiation and cell-specific gene expression. Down-regulated Somult9 also decreases its binding to calmodulin, accumulates calmodulin as receptor-activated kinase and phosphorylase kinase due to the activation of PhK.

Adenocarcinoma↗

PubMed2006

Prostaglandin E2 EP1 receptors: downstream effectors of COX-2 neurotoxicity.

Cyclooxygenase-2 (COX-2), a rate-limiting enzyme for prostanoid synthesis, has been implicated in the neurotoxicity resulting from hypoxia-ischemia, and its inhibition has therapeutic potential for ischemic stroke. However, COX-2 inhibitors increase the risk of cardiovascular complications. We therefore sought to identify the downstream effectors of COX-2 neurotoxicity, and found that prostaglandin E(2) EP1 receptors are essential for the neurotoxicity mediated by COX-2-derived prostaglandin E(2). EP1 receptors disrupt Ca(2+) homeostasis by impairing Na(+)-Ca(2+) exchange, a key mechanism by which neurons cope with excess Ca(2+) accumulation after an excitotoxic insult. Thus, EP1 receptors contribute to neurotoxicity by augmenting the Ca(2+) dysregulation underlying excitotoxic neuronal death. Pharmacological inhibition or gene inactivation of EP1 receptors ameliorates brain injury induced by excitotoxicity, oxygen glucose deprivation and middle cerebral artery (MCA) occlusion. An EP1 receptor inhibitor reduces brain injury when administered 6 hours after MCA occlusion, suggesting that EP1 receptor inhibition may be a viable therapeutic option in ischemic stroke.

Animals↗

PubMed2006

Integrated isotachophoretic preconcentration with zone electrophoresis separation on a quartz microchip for UV detection of flavonoids.

A quartz microchip integrated isotachophoretic (ITP) preconcentration with zone electrophoresis (ZE) separation was fabricated using a novel multi-point pressure method featured in normal temperature and lower pressure during bonding process. ITP followed by subsequential ZE of two flavonoids, quercetin and isorhamnetin on the microchip was performed consecutively on the homemade microfluidic workstation with UV detection, resulting in a decreased detectable concentration of 32-fold, compared to the ZE mode only, and their detection limits decreased down to 0.2 microg/mL and 1.2 microg/mL, respectively.

Electrophoresis, Microchip↗

PubMed2006

Economic burden of Parkinson's disease in a developing country: a retrospective cost analysis in Shanghai, China.

We investigated economic costs from patients with Parkinson's disease (PD) in Shanghai, China, which could be used as a baseline for future evaluations. Data were collected from 190 patients by interview during 1-year period. Direct medical care costs averaged approximately Chinese yuan, renminbi (RMB) 4,305 (USD 519, or EUR 410) per year per patient, of which drugs (RMB 2,677) accounted for the major costly component. Nonmedical direct costs were much less than direct health care costs, averaging approximately RMB 3,301 (USD 398, or EUR 314). Costs due to loss of productivity averaged approximately RMB 73 (USD 8.8, or EUR 7.0) per patient per year. Taken together, the overall mean annual cost for PD in our series was approximately RMB 7,679 (USD 925, or EUR 731), and these costs accounted for around half of the mean annual income. Total cost was significantly associated with the disease severity and the frequency of outpatient visits. In addition, levodopa equivalent dose (LED) and the number of drugs being taken were also closely related with the drug cost. The results indicate that the economic burden of Chinese PD patients is heavy.

Adult↗

PubMed2006

Altered keratin 17 peptide ligands inhibit in vitro proliferation of keratinocytes and T cells isolated from patients with psoriasis.

BACKGROUND: Identification of critical autoantigenic T-cell epitopes is key to developing antigen-based therapies for autoimmune diseases, including psoriasis. Our previous work demonstrated that 3 peptides on keratin 17 are able to stimulate peripheral blood lymphocytes of HLA-DRB1*07-positive patients with psoriasis and to serve as immunodominant T-cell epitopes. OBJECTIVE: We sought to determine antagonistic altered peptide ligands to psoriatic T cells with a down-modulatory effect in inhibiting keratinocyte proliferation. METHODS: Psoriatic altered peptide ligands were generated by single alanine residue substitutions at a critical T-cell receptor contact residue position. Antagonistic altered peptide ligands were identified by suppression screening of psoriatic T-cell activation and keratinocyte proliferation. RESULTS: Altered peptide ligands 119R and 355L can inhibit psoriatic T-cell activation more effectively than other altered peptide ligands, especially 355L, with inhibition of T-cell proliferation and the secretion of interferon gamma and interleukin 2 in parallel with the up-regulation of interleukins 4 and 10 as well as transforming growth factor-beta. In coincubation assay, altered peptide ligands 119R and 355L can down-regulate the function of psoriatic T cells more effectively than wild-type epitopes solely, but less effectively than altered peptide ligands solely. In prepulse assay altered peptide ligand 119R can down-regulate the activation of psoriatic T cells more effectively than in coincubation but less effectively as compared with altered peptide ligand 119R only. Altered peptide ligand 355L was also shown to have a similar presentation. T-cell culture supernatants (1:100) from the concentrations (10 microg.mL(-1) and 100 microg.mL(-1) with 119R, 100 microg.mL(-1) with 355L) were more effective than the other ratios in inhibiting keratinocyte proliferation. LIMITATIONS: This study had a relatively small sample size (52 patients and 48 healthy controls). CONCLUSION: Our findings show that the altered peptide ligands 119R (VAALEEANTELEVKI) and 355L (ENRYCVQASQIQGLI) are capable of inhibiting proliferative responses of psoriatic T cells and keratinocyte proliferation in vitro, at least, with enhanced helper T cell type 2 polarization. Thus, to our knowledge, this article is the first report of the demonstration of therapeutic activity of altered peptide ligands derived from keratin 17.

Cell Proliferation↗

PubMed2006

Antisense oligonucleotides-induced local blockade of T-bet expression leads to airway inflammation in rats.

AIM: To explore whether local blockade of T-box expressed in T cells (T-bet) expression in the lungs could lead to airway inflammation. METHODS: Twenty-four rats were randomly divided into 4 groups: saline group, ovalbumin (OVA)-sensitized group, nonsense group, and the antisense group. The OVA-sensitized rats were sensitized and challenged with OVA, and the rats in the nonsense and antisense groups were subjected to an aerosol delivery of the nonsense and antisense oligonucleotides (AS-ODN) of T-bet (0.1%, w/v). The levels of interferon-gamma (IFN-gamma), interleukin-4 (IL-4), and IL-5 in the bronchoalveolar lavage fluid (BALF) were detected by ELISA, and the mRNA and the protein expression of T-bet and GATA-3 genes were examined by in situ hybridization and Western blot analysis, respectively. RESULTS: The expression of T-bet mRNA and protein in the lungs of the rats in the antisense group were inhibited effectively. The lungs of the rats in the antisense and OVA-sensitized groups showed eosinophil and lymphocyte inflammatory infiltration, and eosinophilia located predominantly around the airways. The number of GATA-3 mRNA-positive cells and the level of GATA-3 protein in the lungs of the rats in the antisense and the OVA-sensitized groups significantly increased. The level of IL-4 and IL-5 in the BALF in the antisense and OVA-sensitized groups were elevated, but the level of IFN-gamma decreased markedly. CONCLUSION: Antisense ODN-induced local blockade of T-bet expression leads to airway inflammation with a selective alteration in patterns of cytokine expression and recruitment of eosinophil cells similar to that in the OVA-sensitized animals.

Animals↗

PubMed2006

Role of inositol 1,4,5-trisphosphate receptors in alpha1-adrenergic receptor-induced cardiomyocyte hypertrophy.

AIM: Intracellular Ca2+ plays pivotal roles in diverse cellular functions, including gene transcription that underlies cardiac remodeling during stress responses. However, the role of inositol 1,4,5-trisphosphate receptors (IP3Rs) in the mediation of cardiac intracellular Ca2+ and hypertrophic growth remains elusive. Prior work with neonatal rat ventricular myocytes suggests that activation of IP3Rs may be linked to a1 adrenergic receptor (alpha1AR) increased stereotyped Ca2+ spark occurrence and global Ca2+ oscillations. Thus, we hypothesized that Ca2+ release through IP3Rs was necessary for alpha1AR-stimulated cardiac hypertrophy. METHODS: We used myoinositol 1,4,5-trisphosphate hexakis (butyryloxymethyl) ester (IP3BM), a membrane-permeant ester of IP3, to activate IP3Rs directly, and Fluo 4/AM to measure intracellular Ca2+ signaling. RESULTS: IP3BM (10 micromol x L(-1)) mimicked the effects of phenylephrine, a selective agonist of alpha1AR, in increments in local Ca2+ spark release (especially in the perinuclear area) and global Ca2+ transient frequencies. More importantly, IP3R inhibitors, 2-aminoethoxydiphenyl borate and Xestospongin C, abolished the IP3BM-induced Ca2+ responses, and significantly suppressed alpha1AR-induced cardiomyocyte hypertrophy assayed by cell size, [3H] leucine incorporation and atrial natriuretic factor gene expression, during sustained (48 h) phenylephrine stimulation. CONCLUSION: These results, therefore, provide cellular mechanisms that link IP3R signaling to alpha1AR-stimulated gene expression and cardiomyocyte hypertrophy.

Adrenergic alpha-1 Receptor Agonists↗

PubMed2006

Ca2+ sparks and Ca2+ glows in superior cervical ganglion neurons.

AIM: Ca2+ release from the endoplasmic reticulum (ER) is an integral component of neuronal Ca2+ signaling. The present study is to investigate properties of local Ca2+ release events in superior cervical ganglion (SCG) neurons. METHODS: Primary cultured SCG neurons were prepared from neonatal rats (P3-P7). Low concentration of caffeine was used to induce Ca2+ release from the ER Ca2+ store, and intracellular Ca2+ was recorded by high-resolution line scan confocal imaging and the Ca2+ indicator Fluo-4. RESULTS: Two populations of local Ca2+ release events with distinct temporal characteristics were evoked by 1.5 mmol/L caffeine near the surface membrane in the soma and the neurites of SCG neurons. Brief events similar to classic Ca2+ sparks lasted a few hundreds of milliseconds, whereas long-lasting events displayed duration up to tens of seconds. Typical somatic and neurite sparks were of 0.3- and 0.52-fold increase in local Fluo-4 fluorescence, respectively. Typical Ca2+ glows were brighter (deltaF/F0 approximately 0.6), but were highly confined in space. The half maximum of full duration of neurite sparks was much longer than those in the soma (685 vs 381 ms). CONCLUSION: Co-existence of Ca2+ sparks and Ca2+ glows in SCG neurons indicates distinctive local regulation of Ca2+ release kinetics. The local Ca2+ signals of variable, site-specific temporal length may bear important implications in encoding a 'memory' of the trigger signal.

Animals↗

PubMed2006

Effective use of corticosteroids in treatment of plastic bronchitis with hemoptysis in Chinese adults.

AIM: To investigate whether corticosteroids are effective in the treatment of plastic bronchitis with hemoptysis. METHODS: A retrospective, clinical study was undertaken. Thirty two patients with only first episodes of plastic bronchitis with hemoptysis were divided into a steroid group (n=18) treated with glucocorticoids, and a non-steroid group (n=14). The supportive therapy was uniformly applied to both groups, except for glucocorticoids. Variables such as temperature and white blood cell counts were determined. Furthermore, the volume of hemoptysis and bronchial casts were evaluated in detail daily. RESULTS: There was no difference in the demographic data and variables at baseline between both groups (all P>0.05). On days 5, 6, 7 and 8, the volume of hemoptysis was significantly decreased in the steroid group compared with the non-steroid group (43+/-15 mL vs 117+/-33 mL on d 5, 29+/-12 mL vs 97+/-23 mL on d 6, 18+/-10 mL vs 80+/-20 mL on d 7, and 13+/-8 mL vs 66+/-14 mL on d 8; all P<0.05), and on d 10 after fibreoptic bronchoscopy, the cases with bronchial casts was reduced evidently in the steroid group in comparison with the non-steroid group (OR=5.69, 95% CI=1.76-43.6; P=0.005). There was no significance in mechanical ventilation and mortality between both groups. CONCLUSION: Despite some limitations of this study, it has been demonstrated that, on the basis of common supportive therapy, corticosteroids would be effective and safe for the treatment of plastic bronchitis with hemoptysis.

Adrenal Cortex Hormones↗

PubMed2006

Inlaying nanoscale surface recess patterns with nanoscale objects.

A simple and versatile approach to constructing patterns on a solid surface using nanoscale objects is demonstrated. The approach is essentially an inlaying process, in which recess patterns fabricated on a surface are selectively filled with nanoscale objects. The objects are anchored firmly on the surface due to the spatial confinement provided by the recess structures. Protein molecules and inorganic nanoparticles are used in this demonstration. Cyclic voltammetry is used to detect electron transfer signals from patterns of protein molecules. The approach suggests a potentially fast, high-throughput and versatile technique for constructing architectural structures on a solid surface using nanoscale objects.

Electrochemistry↗

PubMed2006

Overexpression of interleukin 21 induces expansion of hematopoietic progenitor cells.

The interleukin 21 (IL-21) receptor is expressed on T-cells, B-cells, and natural killer cells, and IL-21 is critical for regulating immunoglobulin production in vivo in cooperation with IL-4. So far, however, little is known about a role for IL-21 outside the immune system. We investigated the effect of IL-21 on hematopoiesis in vivo by using the hydrodynamics gene-delivery method. Overexpression of IL-21 increases Sca-1+ cells in the periphery and spleen. It also increases the numbers of c-Kit+, Sca-1+, and lineage-/low (KSL) cells and colony-forming units-granulocyte-macrophage (CFU-GM) in the spleen, indicating the expansion of hematopoietic progenitor cells. We found that even in RAG2-/- mice, which lack mature T-cells and B-cells, IL-21 induced an increase in KSL cells and CFU-GM in the spleen. These results demonstrate that IL-21 can induce the expansion of hematopoietic progenitor cells in vivo, even in the absence of mature T-cells and B-cells.

Animals↗

PubMed2006

Significance of Id-1 up-regulation and its association with EGFR in bladder cancer cell invasion.

Epidermal growth factor receptor (EGFR) is suggested to be one of the positive factors in the invasive progression of bladder cancer. Id-1 (inhibitor of differentiation or DNA binding), a helix-loop-helix (HLH) transcription factor, was recently identified as a key factor in the EGFR signalling pathway. The aim of this study was to investigate the role of Id-1 in bladder cancer progression and its relation-ship with EGFR. Using clinical specimens from different stages of bladder cancer, immunohistochemical staining was performed to determine if Id-1 expression was positively associated with tumour staging and EGFR expression. The direct role of Id-1 in cancer cell invasion was also investigated through ectopically expressing the Id-1 gene in a RT112 bladder cancer cell line by wound closure and collagen invasion assays. To explore the therapeutic potential of targeting the Id-1 gene in the treatment of invasive bladder cancer, we studied if inactivation of the Id-1 gene through small RNA interference could lead to the suppression of invasion in a MGHU1 bladder cancer cell line. Our results showed that the up-regulation of Id-1 was associated with increased EGFR expression, clinical staging and the invasion ability of bladder cancer cells. Inactivation of Id-1 may be a potential therapeutic target to inhibit the invasion by bladder cancer cells.

Blotting, Western↗

PubMed2006

[Effect of dexamethasone on expression of fractalkine in lipopolysaccharide-induced acute lung injury].

OBJECTIVE: To investigate the effect of dexamethasone on the expression of fractalkine (FKN) in lipopolysaccharide (LPS)-induced acute lung injury (ALI). METHODS: The rat model of ALI was established by injection of LPS at the dose of 4 mg/kg. 42 Wistar rats were randomly divided into the normal group (n=6), LPS group (n=18), and dexamethasone (DEX) group (n = 18), and then the rats in both LPS and DEX groups were divided into three subgroups (1 h, 2 h and 4 h after injection of LPS), respectively. The pathological condition and the wet/dry ratio (W/D) of the lung were observed, and serum TNF-alpha level, and FKN mRNA of the lung were detected with ELISA and RT-PCR. RESULTS: The W/D, serum TNF-alpha level, and FKN mRNA of the lung were significantly increased in LPS group, compared with those in normal group (all P < 0.05), but the W/D, serum TNF-alpha level, and FKN mRNA of the lung in the DEX group were much more decreased than those in the LPS group (all P < 0.05). In addition, the expression of FKN mRNA in the lung tissue positively correlated with the concentration of TNF-alpha (r = 0.674, P <0.05). CONCLUSION: The findings suggested that pre-treatment with dexamethasone could inhibit the TNF-alpha level and prevent the increase of the expression of FKN mRNA, which may be one of the mechanisms by which DEX serves as a protection against LPS-induced lung injury.

Animals↗

PubMed2006

[Inhibitory effects of tetraethylammonium on proliferation and voltage-gated potassium channels in human cervical carcinoma cell line SiHa].

BACKGROUND & OBJECTIVE: Various potassium channels are known to be involved in proliferation of many malignant cell lines. This study was to explore the role of voltage-gated potassium channels in proliferation of human cervical carcinoma cells through observing the effects of tetraethylammonium (TEA) on proliferation and outward potassium currents in human cervical carcinoma cell line SiHa. METHODS: SiHa cells were treated with TEA. The effect of TEA on proliferation of SiHa cells was assessed by MTT assay. Cell apoptosis and cell cycle were detected by flow cytometry with Hoechst 33258 staining. The outward potassium currents were recorded by patch clamp technique. RESULTS: TEA inhibited the proliferation of SiHa cells in dose-and time-dependent manners, and induced cell apoptosis. The cell cycle was arrested at G0/G1 phase after treatment with TEA. Exposure of SiHa cells to 10 mmol/L TEA reduced the peak outward potassium currents significantly from (260+/-12) pA to (58+/-6) pA (P<0.01). CONCLUSIONS: Voltage-gated potassium channels play an important role in regulating proliferation of cervical carcinoma SiHa cells. Blocking voltage-gated potassium channels could inhibit proliferation of SiHa cells.

Apoptosis↗

PubMed2006

[Effect of perioperative continuous epidural morphine administration on plasma D-dimer in patients undergoing total hip replacement].

OBJECTIVE: To evaluate the effect of perioperative continuous epidural morphine administration on plasma D-dimer level in patients undergoing total hip replacement. METHODS: Forty ASA I-II patients undergoing total hip replacement under epidural anesthesia were randomized into two groups. In one group, the patients were given epidural administration of morphine 15 min before operation at 4 mg (in 10 ml normal saline) and for 48 h after the operation at 80 microg/h, while those in the other group received epidural injection of the same amount of normal saline before operation and 0.15% ropivacaine 2.0 ml/h for 48 h in the same manner after operation. Blood samples were taken before anesthesia (T(0)), at the end of operation (T(1)), and 24 h and 48 h after operation (T(2) and T(3)) for determination of plasma IL-6 and D-dimer levels. RESULTS: In both groups plasma IL-6 and D-dimer levels showed significant increase at T(1), T(2) and T(3) in comparison with those at T(0), and their levels were significantly lower in morphine group than in ropivacaine group at T(1), T(2) and T(3). CONCLUSION: Epidural morphine can lower plasma IL-6 and D-dimer levels and correct blood hypercoagulability in patients undergoing total hip replacement.

Aged↗

PubMed2006

[Problems and strategies in clinical trials of traditional Chinese medicine].

To explore the problems and the strategies in clinical trials of traditional Chinese medicine (TCM), including the method and concealment of randomizing, equipoise of baseline, blindness and outcome measures, adverse reaction observation, statistical method and publication bias. The consolidated standard of reporting trials (CONSORT) is recommended to be applied in order to improve the quality of design and report of randomized controlled trials (RCTs) of TCM, and in case of human is taken as the subject of trial, according to the fundamental ethical principle, the clinical trial design should be censored by institutional review board (IRB), and the informed consent should be signed to protect the rights and interests of the trial participator.

Humans↗