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Gang Cheng

Publications and source records attributed to Gang Cheng.

At least 73 records · Page 4Linked to original sources
PubMed2003

Decrease of intracellular ATP content downregulated UCP2 expression in mouse hepatocytes.

Mitochondrial uncoupling protein 2 (UCP2) plays an important role in regulating energy metabolism. We previously reported that UCP2 expression in steatotic livers is increased which leads to diminished hepatic ATP stores and renders steatotic hepatocytes vulnerable to ischemic damage. In this study, reagents that inhibit the production of ATP were used to mimic an ischemic state in the liver in order to investigate the effects of decreased intracellular ATP levels on UCP2 expression in a murine hepatocyte cell line (HEP6-16). Carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP), an oxidative phosphorylation uncoupler, was found to decrease intracellular ATP levels in a dose- and time-dependent manner. Relatively high concentrations of FCCP from 8 to 80 microM were required to reduce the intracellular concentration of ATP. The inhibitory effect of FCCP on intracellular ATP was significantly potentiated by 2-deoxy-D-glucose, an inhibitor of glycolysis that when administered alone had no negative effect on cellular ATP levels in mouse hepatocytes. Decreased intracellular ATP levels were accompanied by lower UCP2 mRNA expression. Upon removal of FCCP and/or 2-deoxy-D-glucose and reculture with normal medium, ATP and UCP2 mRNA levels returned to normal within a few hours. Mitochondrial membrane potential in HEP6-16 cells was dissipated by 80 microM FCCP but not 8 microM FCCP, suggesting that the downregulation of UCP2 expression by FCCP was not related to mitochondrial potential changes. Consequently, the in vitro manipulation of ATP stores is consistent with the in vivo observations associated with ischemia/reperfusion injury.

Adenosine Triphosphate↗
PubMed2003

Prostaglandin D2 reinforces Th2 type inflammatory responses of airways to low-dose antigen through bronchial expression of macrophage-derived chemokine.

PGD2, a lipid mediator released from mast cells, is known to participate in allergic reactions. However, the mechanism by which PGD2 contributes to such reactions remains unclear. We established a novel experimental model of asthma that permitted direct assessment of the role of PGD2 in airway inflammation. Antigen-sensitized mice were exposed to aerosolized prostaglandin D2 (PGD2) 1 d before challenge with low-dose aerosolized antigen. Not only the numbers of eosinophils, lymphocytes, and macrophages but also the levels of IL-4 and IL-5 in bronchoalveolar lavage fluid were higher in PGD2-pretreated mice than in control mice. The expression of macrophage-derived chemokine (MDC), a chemoattractant for Th2 cells, was greater in PGD2-pretreated mice than in control. Injection of anti-MDC antibody into PGD2-pretreated mice markedly inhibited inflammatory cell infiltration as well as Th2 cyto-kine production after antigen challenge. These results indicate that PGD2 accelerates Th2 type inflammation by induction of MDC. Our results suggest that this mechanism may play a key role in the development of human asthma and that MDC might be a target molecule for therapeutic intervention.

Animals↗
PubMed2003

Automatic localization of implanted seeds from post-implant CT images.

An automatic localization method of implanted seeds from a series of post-implant computed tomography (CT) images is described in this paper. Post-implant CT studies were obtained for patients who underwent prostate brachytherapy. Bright areas were segmented using binary thresholding in each CT slice, and geometrical information on these areas was collected. Large areas (possibly containing two connected seeds) were split into smaller ones by geometry-based filtering in each slice. The area connectivity along the longitudinal direction was analysed using a geometry-based connection search algorithm executed on every area slice by slice, so that the connected areas were combined into one object. The weighted centroid of each object was taken as the seed position. This method was tested on a seed-containing prostate phantom as well as using CT studies from patients. Statistical analysis demonstrates that it can achieve above 99% detection rate with reliable localization accuracy and high speed. It is reliable and convenient for localizing implanted seeds on CT and can be used to assist post-implant dosimetry for prostate brachytherapy.

Algorithms↗
PubMed2003

[Immunohistochemical research of integrin alpha 5 expression during mandibular fracture healing].

OBJECTIVE: To investigate the expression change of integrin alpha 5 during mandibular fracture healing. METHODS: Using rabbit mandibular fracture model, the fractured bone tissues were obtained and paraffin slices were made on the days of 1, 3, 5, 7, 14, 30, 60 and 90 after surgery, respectively. Non-fractured mandibles were used as normal control. LsAB immunohistochemical method was used to detect the expression of integrin alpha 5 in bone tissue, especially on osteoblasts and osteoclasts. RESULTS: Integrin alpha 5 was widely expressed in fractured bone and surrounding soft tissues. The expression of integrin alpha 5 increased 7 days after fracture, peaked in 14 to 30 days and returned to nearly normal in 60-90 days. CONCLUSION: During mandibular fracture healing, the expression of integrin alpha 5 in bone tissue increased clearly. It is estimated that integrin alpha 5 players an important role in fracture healing.

Animals↗
PubMed2003

Protonation equilibrium and lipophilicity of olamufloxacin (HSR-903), a newly synthesized fluoroquinolone antibacterial.

This study was performed to characterize the protonation equilibrium at the molecular level and pH-dependent lipophilicity of olamufloxacin. The deprotonation fraction of the carboxyl group as a function of pH was specifically calculated at the critical wavelength 294 nm, where UV pH-dependent absorbance of olamufloxacin was independent of the ionized state of the aminopyrrolidinyl amino group but heavily depended on that of the carboxyl moiety. Accordingly, micro-protonation equilibrium could be described using a nonlinear least-squares regression program MULTI. In contrast, macro-protonation equilibrium was depicted at most wavelengths where olamufloxacin absorbance was influenced by ionized states of both proton-binding groups, results coinciding with the former. Furthermore, distribution features of four microspecies in aqueous phase were assessed. The apparent partition coefficient versus pH profile of olamufloxacin showed a parabolic curve in n-octanol/buffer system which reached peak near pH 8, agreeing with the above determined isoelectric point (pI). Ion-pair effect was observed for olamufloxacin under an acidic condition, eliciting experimental values higher than those theoretically calculated, which was similar to ciprofloxacin but not levofloxacin due to amino group type. Moreover, olamufloxacin was moderately lipophilic in comparison with other quinolones, with an apparent partition coefficient of 1.95 at pH 7.4.

Anti-Bacterial Agents↗
PubMed2003

Effects of CD80 and CD86 on cytokine production in patients with wasp-venom allergy who receive venom immunotherapy.

Several studies have provided evidence that activation of antigen-specific T cells requires interactions between CD28 on T cells and its ligands, CD80 and CD86, on antigen-presenting cells (APCs). However, the effects of CD80 and CD86 on cytokine production in patients with Hymenoptera venom allergy who receive venom immunotherapy remain unclear. We examined the effects of CD80 and CD86 on Th1- and Th2-cytokine production before and after venom immunotherapy in patients with wasp-venom allergy. Peripheral blood mononuclear cells (PBMCs) were isolated from patients with wasp-venom allergy before and after three months of venom immunotherapy. CD4+ T cells and monocytes were isolated as APCs from PBMCs and were cocultured with wasp venom in the presence of anti-CD80 or -CD86 blocking antibodies. Interleukin (IL)-4, IL-10, and interferon (IFN)-gamma were measured by enzyme-linked immunosorbent assay. The expression of CD80 and CD86 on CD14+ PBMCs was detected by fluorescence-activated cell-sorter analysis. The expression of CD86, but not that of CD80, on CD14+ PBMCs cocultured with venom increased after three months of venom immunotherapy, but not before venom immunotherapy. Blockade of CD86 reduced IL-10 production after three months of venom immunotherapy. IL-10 production promoted by CD86 costimulation may be involved in the mechanism of venom immunotherapy in patients with venom allergy.

Antigens, CD↗
PubMed2003

Apoptosis induced by simvastatin in rat vascular smooth muscle cell through Ca2+-calpain and caspase-3 dependent pathway.

Several studies have shown that simvastatin induces apoptosis in a variety of cell lines including vascular smooth muscle cells (VSMCs), but the exactly mechanisms involved in it is not very clear. The aim of this study was to investigate the mechanisms and signal pathways involved in apoptosis induced by simvastatin. When exposed to 30 microM simvastatin, [Ca2+]i in VSMCs increased with time and reached to 336 +/- 52 nM at 6 h, more than four-fold of control (P<0.01, n=5). Verapamil (80 microM), a membrane voltage-dependent Ca2+ channel blocker, attenuated simvastatin-induced augmentation of free calcium concentration from 336 +/- 52 nM to 144 +/- 34 nM (P<0.01). After being exposed to 30 microM simvastatin for 8 h, calpain activity markedly increased (P<0.05, n=4) and reached to more than three-fold of control at 12 h (P<0.01). Caspase-3 was also activated by simvastatin after 12 h. Verapamil and PD150606, a cell-permeable selective calpain inhibitor, significantly inhibited simvastatin-induced augmentation of calpain activity and blocked caspase-3 activation, respectively. Furthermore, 80 microM verapamil and 100 microM PD150606 decreased simvastatin-induced apoptosis rate from 24.2 +/- 1.7% to 7.9 +/- 0.6% (P<0.01, n=4) and 9.5 +/- 1.9% (P<0.01), respectively and also prevented simvastatin-induced DNA laddering. In conclusion, we indicated that simvastatin increases cytosolic free calcium concentration mainly through calcium influx from extracellular solution and then induces apoptosis by activating caspase-3 via calcium-dependent protease calpain.

Acrylates↗
PubMed2003

Production of TARC and MDC by naive T cells in asthmatic patients.

The helper (Th)2 cell-attracting chemokines thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) are ligands for the chemokine receptor CCR4. A number of cellular sources of TARC and MDC have been identified, including not only macrophages, dendritic cells, and natural killer cells, but also bronchial epithelial cells. Recent studies report that TARC and MDC may serve as pivotal chemokines for the development of Th2-dominated experimental allergen-induced asthma. This study was designed to assess TARC and MDC production by CD4+ T cells, including naive T cells and memory/effector T cells, purified from peripheral blood mononuclear cells in patients with asthma. Asthmatic subjects included in this study had mild asthmatic symptoms, positive skin test responses to house dust mite allergen, and elevated level of Dermatophagoides farinae immunoglobulin E in the sera. CD4+ T cells--CD45RA+ CD4+ T cells--as naive T cells and CD45RO+ CD4+ T cells--as memory/effector T cells--were purified by negative selection from peripheral blood mononuclear cells obtained from asthmatic patients (n = 6) and healthy controls (n = 6). These cells and established Th1/Th2 cell lines were then cultured in the presence of both anti-CD3 and -CD28 antibodies. After 48 hr of incubation, concentrations of TARC, MDC, interleukin (IL)-4, IL-5, and interferon-gamma in the supernatants were measured by enzyme-linked immunoadsorbent assay. Reverse transcriptase-polymerase chain reaction was performed to analyze mRNA expression of TARC and MDC. Our results clearly showed that TARC and MDC were produced by activated CD45RA+ CD4+ T cells rather than by activated CD45RO+ CD4+ T cells, and the levels of these chemokines in the asthmatic patients were higher than those in the healthy controls. Furthermore, these chemokines production by Th2 cell lines were greater than those by Th1 cell lines, but the level were smaller than those by naive T cells. Our studies suggest that TARC and MDC are produced by naive T cells rather than by memory/effector T cells, including Th2 cells, in asthmatic patients, and these chemokines were produced at modest levels in any T-cell populations from healthy controls. Taken together, naive T cells in asthma have a peculiar function to produce TRAC and MDC, which contribute to local migration of Th2 cells into lung and lymphoid tissues, along with a function as precursor for memory/effector T cell. This novel function of naive T cells may be implicated in the development of asthma.

Adult↗
PubMed2003

[Effects of Bakumondo-to (Mai-Men-Dong-Tang) on cough sensitivity to capsaicin in asthmatic patients with cough hypersensitivity].

UNLABELLED: Some patients with bronchial asthma have increased cough sensitivity. In such patients coughing may be an inducer of wheeze. The aim of the present study was to investigate the effect of Bakumondo-to on the cough sensitivity and respiratory tract inflammation in asthmatic patients with increased cough sensitivity. In addition influences of intensity of respiratory tract inflammation, gender, type of asthma, and disease period on the effect of Bakumondo-to on the cough sensitivity were examined. Twenty-one bronchial asthmatics whose cough thresholds to capsaicin were less than 3.9 microM were examined. METHODS: Cough thresholds to capsaicin (concentration of inhaled capsaicin solution causing 5 or more coughs) was measured before and after 2 months or more treatment with Bakumondo-to (9 g/day, TJ-29). Number of eosinophils in peripheral blood, sputum eosinophil ratio, and ECP level in the serum were also measured before and after treatment. RESULTS: Bakumondo-to significantly increased the cough threshold. Although respiratory tract inflammation was not significantly improved, number of eosinophils in peripheral blood, sputum eosinophil ratio and ECP level in the serum were remarkably decreased more than the half. And Bakumondo-to was more effective in asthmatic subjects with severe airway inflammation. Furthermore, a greater effect of it was observed in women. A greater effect was also observed in patients having a disease duration of less than 1 year. CONCLUSION: Our results suggest that Bakumondo-to may be an effective therapeutic preparation for coughing in asthmatic patients with cough hypersensitivity.

Adolescent↗
PubMed2003

[Clinical application of acellular allogenic dermis with autogenous epithelium in wound repair].

OBJECTIVE: To observe the clinical effect of acellular allogenic dermis with split-thickness autogenous skin graft for coverage of wound. METHODS: Acellular allogenic dermis with split-thickness autogenous skin graft was used to repair 34 wounds of head, neck, trunk and extremities. The area of wounds was from 5 cm x 10 cm to 12 cm x 19 cm. Out of 34 wounds, there were 2 due to old granulation, 4 due to excision of giant pigmented nevus, 6 due to excision of capillary hemangioma of skin and 22 due to excision of scar. RESULTS: All grafts survived and had the smooth surface without obvious pigmentation and with slight wound contraction. CONCLUSION: Acellular allogenic dermis with autologous epithelium for coverage of various wounds is an ideal procedure.

Adolescent↗
PubMed2003

Establishment of a fluorescent polymerase chain reaction method for the detection of the SARS-associated coronavirus and its clinical application.

OBJECTIVE: To establish a fluorescent polymerase chain reaction (F-PCR) method for detecting the coronavirus related to severe acute respiratory syndrome (SARS) and to evaluate its value for clinical application. METHODS: The primers and the fluorescence-labeled probe were designed and synthesized according to the published sequence of the SARS-associated coronavirus genes. A F-PCR diagnosis kit for detecting the coronavirus was developed, and 115 clinical nasopharyngeal gargling liquid samples were tested. RESULTS: The sequence of PCR amplified products completely matched the related sequence of the SARS-associated coronavirus genome. Forty-nine out of 67 samples from identified SARS patients and 8 of 18 samples from persons having close contact with SARS patients showed positive results. All 30 samples from healthy controls were negative. CONCLUSION: The F-PCR method established may be a rapid, accurate and efficient way for screening and for the early diagnosis of SARS patients.

Fluorescence↗
PubMed2003

His-Purkinje lineages and development.

The heartbeat is initiated and coordinated by a multi-component set of specialized muscle tissues collectively referred to as the pacemaking and conduction system. Over the last few years, impetus has gathered into unravelling the cellular and molecular processes that regulate differentiation and integration of this essential cardiac network. One focus of our collective work has been the developmental history of cells comprising His-Purkinje tissues of the conduction system. This interest in part arose from studies of the expression of connexins in periarterial Purkinje fibres of the chick heart. Using lineage-tracing strategies, including those based on replication-defective retroviruses and adenoviruses, it has been shown that conduction cells are derived from multipotent, cardiomyogenic progenitors in the tubular heart. Moreover, heterogeneity within myocardial clones has indicated that the elaboration of the conduction system in the chick embryo occurs by progressive, localized recruitment from within this pool of cardiomyogenic cells. Cell birth dating has revealed that inductive conscription of cells to central elements of the conduction system (e.g. the His bundle) precedes recruitment to the peripheral components of the network (i.e. subendocardial and periarterial Purkinje fibres). Birth dating studies in rodents suggest an analogous recruitment process is occurring in this species. In addition to summarizing earlier work, this chapter provides information on ongoing studies of cell-cell signalling and transcriptional mechanisms that may regulate the development of His-Purkinje tissues.

Animals↗
PubMed2003

Efficacy and safety of rush immunotherapy in patients with Hymenoptera allergy in Japan.

In Japan, approximately 40 persons die annually from anaphylaxis caused by Hymenoptera stings. Venom immunotherapy is considered safe and effective for the treatment of allergic systemic reactions caused by Hymenoptera stings in patients with Hymenoptera allergy. We studied the efficacy and safety of rush immunotherapy in patients who had a history of systemic reactions to Hymenoptera stings in Japan. Between 1988 and 2002, 95 patients with a history of systemic reactions to Hymenoptera stings were investigated. The stings originated from honeybees in 5 patients, yellow jackets in 28, wasps in 48, both yellow jackets and wasps in 9, and both yellow jackets and honeybees in 5. All patients had venom-specific IgE antibodies in sera (RAST score > or = 2) and received rush immunotherapy with venom extracts at our hospital. Forty-three patients had 63 field re-stings during immunotherapy. Of these patients, 41 (95.3%) with 59 field re-stings (93.7%) had no systemic reactions. Two patients (4.7%) with four field restings (6.3%) had anaphylactic shock. Although anaphylactic reactions developed in two patients (2.1%) during rush immunotherapy with honeybee venom and one patient (1.1%) during maintenance therapy wasp venom, systemic adverse reactions were mitigated by treatment with antihistamines before venom injection. Our results show that immunotherapy is safe and effective for the prevention of systemic reactions to Hymenoptera re-stings in patients with Hymenoptera allergy. We therefore recommend that patients who are allergic to Hymenoptera venom prophylactically receive immunotherapy.

Adolescent↗
PubMed2003

[Comparative study of lipophilicity from immobilized artificial chromatography and n-octanol/buffer systems].

AIM: To compare lipophilicity measuring scale stemmed from immobilized artificial membrane chromatography and n-octanol/buffer systems. METHODS: A test set consisted of 27 structurally diverse compounds. The lipophilicity of these were evaluated by both immobilized artificial membrane chromatography (IAMC) and n-octanol/buffer systems, which were expressed as lg kIAM and lg DO/W,7.4, respectively. RESULTS: With regard to each individual group, good correlation coefficient (r2) over 0.81 was obtained (0.82 for acid; 0.88 for neutral, 0.81 for base and 0.92 for ampholyte, respectively). However, a smaller r2 (0.62) was acquired for all compounds studied than that of each individual group. CONCLUSION: IAMC and n-octanol/buffer systems were shown to be different in lipophilicity.

Buffers↗
PubMed2003

[Evaluation of interaction between drugs and ordered phospholipid membrane by immobilized artificial membrane chromatography].

AIM: To investigate the interaction between drugs and ordered phospholipid membrane using immobilized artificial membrane chromatography (IAMC). METHODS: IAMC was used to determine the interaction drugs with phospholipid membrane, expressed as membrane affinity (lg kIAM). An n-octanol/buffer system was also employed as the reference hydrophobicity (lg Do/w,7.4). RESULTS: Within the range of used acetonitrile percentages (phi) 0-30% in mobile phase, retention index (lg kIAM) showed excellent correlation with phi. Intercepts of fitted straight lines between lg kIAM and phi were comparable but slopes were much different for the three organic modifiers (acetonitrile, ethanol and methanol). Effects by adding CH2 substituent on lipophilicity difference (delta lg kIAM and delta lg Do/w,7.4) were similar for p-hydroxyl benzoic methyl ester to butyl ester, whereas different for p-hydroxylbenzoic acid to methyl ester. CONCLUSION: IAMC system is a convenient, efficient and rapid tool for determining membrane interaction.

Membranes, Artificial↗
PubMed2002

Early development of the hypothalamus of a wallaby (Macropus eugenii).

We have studied the development of the hypothalamus of an Australian marsupial, the tammar wallaby (Macropus eugenii), to provide an initial anatomic framework for future research on the developing hypothalamus of diprotodontid metatheria. Cytoarchitectural (hematoxylin and eosin), immunohistochemical (CD 15 and growth associated protein, GAP-43), tritiated thymidine autoradiography, and carbocyanine dye tracing techniques were applied. Until 12 days after birth (P12), the developing hypothalamus consisted of mainly a ventricular germinal zone with a thin marginal layer, but by P25, most hypothalamic nuclei were well differentiated, indicating that the bulk of hypothalamic cytoarchitectural development occurs between P12 and P25. Strong CD 15 immunoreactivity was found in radial glial fibers in the rostral hypothalamus during early developmental ages, separating individual hypothalamic compartments. Immunoreactivity for GAP-43 was used to reveal developing fiber bundles. The medial forebrain bundle was apparent by P0, and the fornix appeared at P12. Tritiated thymidine autoradiography revealed lateral-to-medial and dorsal-to-ventral neurogenetic gradients similar to those seen in rodents. Dye tracing showed that projections to the posterior pituitary arose from the supraoptic nucleus at P5 and from the paraventricular nucleus at P10. Projections to the medulla were first found from the lateral hypothalamic area at P0 and paraventricular nucleus at P10. In conclusion, the pattern of development of the wallaby hypothalamus is broadly similar to that found in eutheria, with comparable neurogenetic compartments to those identified in rodents. Because most hypothalamic maturation takes place after birth, wallabies provide a useful model for experimentally manipulating the developing mammalian hypothalamus.

Animals↗
PubMed2002

Anti-interleukin-9 antibody treatment inhibits airway inflammation and hyperreactivity in mouse asthma model.

Numerous in vitro and in vivo studies in both animals and patients with asthma have shown that interleukin (IL)-9 is an important inflammatory mediator in asthma. To examine the effects of IL-9 antagonism on airway inflammation, ovalbumin-sensitized BALB/c mice were intravenously given anti-IL-9 antibody or an isotype-matched control antibody 30 minutes before challenge with aerosolized ovalbumin. Airway response to methacholine was measured, and samples of bronchoalveolar lavage fluid (BALF) were obtained 24 hours after the last antigen challenge. Lung tissue was harvested and examined histopathologically. After ovalbumin challenge, there were significant increases in airway hyperreactivity, the numbers of inflammatory cells in lung, and IL-4, IL-5, and IL-13 production in BALF. Treatment with anti-IL-9 antibody significantly prevented airway hyperreactivity in response to methacholine inhalation. Blockade of IL-9 reduced the numbers of eosinophils (0.3 +/- 0.1 x 10(5) and 23.6 +/- 0.5 x 10(5)/ml, anti-IL-9 antibody/control immunoglobulin G) and lymphocytes (0.2 +/- 0.2 x 10(5) and 0.8 +/- 0.1 x 10(5)/ml) in BALF. Anti-IL-9 antibody treatment also reduced the concentrations of IL-4 (from 70.6 +/- 4.6 to 30.8 +/- 5.2 pg/ml), IL-5 (from 106.4 +/- 12 to 54.4 +/- 6.6 pg/ml), and IL-13 (from 44.2 +/- 7.6 to 30.1 +/- 5.5 pg/ml) in BALF. Macrophage-derived cytokine expression in the airways was also decreased by IL-9 blockade. Taken together, our findings emphasize the importance of IL-9 in the pathogenesis of asthma and suggest that blockade of IL-9 may be a new therapeutic strategy for bronchial asthma.

Animals↗