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Hong Meng

Publications and source records attributed to Hong Meng.

18 recordsLinked to original sources
PubMed2007

Quantitative assessment of small intraosseous prostate cancer burden in SCID mice using fluorescence imaging.

BACKGROUND: Experimental bone metastases are typically analyzed when the skeletal tumor burden is large enough to be detected by imaging or histology. By this time, the bone microenvironment is usually destroyed, preventing useful analysis of tumor-bone interactions. METHODS: Small intraosseous tumors generated by intratibial injection of C4-2B prostate cancer cells transfected with green fluorescent protein (GFP) were assessed using in vivo and ex vivo fluorescence imaging, radiography, histology, and fluorometric analysis of bone lysates. RESULTS: Ex vivo fluorescence imaging and fluorometric analysis were capable of detecting tiny bone tumors as early as 10 days after injection. Ex vivo fluorescence imaging allowed simple quantification of small skeletal tumor burden and was useful in measuring the effect of systemic therapy. CONCLUSIONS: Ex vivo fluorescence imaging is a sensitive and easy method to quantify small skeletal tumor burden. This technique allows investigation of tumor-bone interactions while the bone microanatomy is still intact.

Animals↗
PubMed2006

Hexathiapentacene: structure, molecular packing, and thin-film transistors.

In this communication we report the electrical characteristics of hexathiapentacene (HTP) and emphasize the unusual chemical structure and molecular packing. We report field-effect mobilities as high as 0.04 cm2 V-1 s-1 and current on/off ratios of >105. With crystallographic evidence of unusually long S-S bonds compared to normal S-S bonds, we have suggested a unique resonance structure similar to trithiapentalene, which well explains the bonding characteristics of HTP. This work appears to be the first to determine its molecular structure/packing mode and to study its application in organic transistors.

Journal Article↗
PubMed2006

2,6-Bis[2-(4-pentylphenyl)vinyl]anthracene: a stable and high charge mobility organic semiconductor with densely packed crystal structure.

The development of new organic semiconductors with improved electrical performance and enhanced environmental stability is the focus of considerable research activity. This paper presents the design, synthesis, optical and electrochemical characterization, crystal packing, modeling and thin film morphology, and organic thin film field effect transistor (OTFT) device data analysis for a novel 2,6-bis[2-(4-pentylphenyl)vinyl]anthracene (DPPVAnt) organic semiconductor. We observed a hole mobility of up to 1.28 cm2/V.s and on/off current ratios greater than 107 for OTFTs fabricated using DPPVAnt as an active semiconductor layer. The mobility value is comparable to that of the current best p-type semiconductor pentacene-based device performance. In addition, we found a very interesting relationship between the charge mobility and molecule crystal packing in addition to the thin film orientation and morphology of the semiconductor as determined from single-crystal molecule packing study, thin film X-ray diffraction, and AFM measurements. The high performance of the semiconductor ranks among the best performing p-type organic semiconductors reported so far and will be a very good candidate for applications in organic electronic devices.

Journal Article↗
PubMed2006

Inhibition of human prostate cancer growth, osteolysis and angiogenesis in a bone metastasis model by a novel mechanism-based selective gelatinase inhibitor.

Metastasis to the bone is a major clinical complication in patients with prostate cancer (PC). However, therapeutic options for treatment of PC bone metastasis are limited. Gelatinases are members of the matrix metalloproteinase (MMP) family and have been shown to play a key role in PC metastasis. Herein, we investigated the effect of SB-3CT, a covalent mechanism-based MMP inhibitor with high selectivity for gelatinases, in an experimental model of PC bone metastases. Intraperitoneal (i.p.) treatment with SB-3CT (50 mg/kg) inhibited intraosseous growth of human PC3 cells within the marrow of human fetal femur fragments previously implanted in SCID mice, as demonstrated by histomorphometry and Ki-67 immunohistochemistry. The anti-osteolytic effect of SB-3CT was confirmed by radiographic images. Treatment with SB-3CT also reduced intratumoral vascular density and bone degradation in the PC3 bone tumors. A direct inhibition of bone marrow endothelial cell invasion and tubule formation in Matrigel by SB-3CT in vitro was also demonstrated. The use of the highly selective gelatinase inhibitors holds the promise of effective intervention of metastases of PC to the bone.

Animals↗
PubMed2006

Arsenic-related skin lesions and glutathione S-transferase P1 A1578G (Ile105Val) polymorphism in two ethnic clans exposed to indoor combustion of high arsenic coal in one village.

OBJECTIVES: A total of 2402 patients with arsenic-related skin lesions, such as hyperkeratosis, hyperpigmentation or hypopigmentation, or even skin cancer in a few villages in Southwest Guizhou Autonomous Prefecture, China represent a unique case of endemic arsenism related with indoor combustion of high arsenic coal. This study aimed to investigate the cluster of arsenism cases and the possible relevant factors including GSTP1 polymorphism in two clans of different ethnic origin living in one village for generations. METHODS: A questionnaire-based study was performed in 170 Miao clan P members, 10 of whom had arsenic-related skin diseases, and 153 Han clan G1 members, 50 of whom had arsenic-related skin diseases. The data were checked against the registration archives since the 1980s. At the same time, arsenic concentrations in samples of coal, indoor air, drinking water, corn and chilli pepper that were once baked over the stoves for desiccation, as well as in samples of urine and hair of clan members were determined. Glutathione S-transferase P1 (GSTP1) A1578G polymorphism was genotyped by a restriction fragment length polymorphism-based procedure. RESULTS: Arsenism morbidity in Miao clan P was significantly lower than in the neighbouring Han clan G1 [5.9 vs. 32.7%, odds ratio (OR)=0.13, 95% confidence interval (CI): 0.06-0.27, P<0.0001]. No sex differences were confirmed inside both clans. Analyses of the environmental samples indicated that Miao clan P members were exposed to higher amounts of arsenic via inhalation and food ingestion. Hair and urine samples also proved a higher arsenic body burden in ethnic Miao individuals. No corresponding differences by sex were found. Higher frequencies of combined mutant genotype G/G1578 and A/G1578 (OR=4.72, 95% CI: 2.34-9.54, P<0.0001) and of mutant allele G1578 (OR=3.22, 95% CI: 2.00-5.18, P<0.0001) were detected in diagnosed arsenism patients than in non-diseased individuals. The Miao individuals showed a lower percentage of combined mutant genotypes (30.6 vs. 52.7%, OR=0.40, 95% CI: 0.19-0.84, P=0.015) as well as of mutant allele G1578 (OR=0.46, 95% CI: 0.24-0.88, P=0.017) than their Han neighbours. CONCLUSIONS: Genetic predisposition influences dermal arsenism toxicity. The GSTP1 A1578G (Ile105Val) status might be a susceptibility factor for arsenic-related skin lesions.

Adolescent↗
PubMed2006

[On the important role of Siguan points in treatment of chronic fatigue syndrome].

OBJECTIVE: To probe into the role of Siguan points in treatment of chronic fatigue syndrome. METHODS: Based on diagnosis, pathogenesis and etiology of chronic fatigue syndrome in TCM, the role of Siguan points in treatment of chronic fatigue syndrome were induced by means of relative literatures of Siguan points in recent 10 years from 3 aspects. CONCLUSION: Acupuncture at Siguan as main points has a better therapeutic effect on chronic fatigue syndrome.

Acupuncture Points↗
PubMed2006

[Inhibitory effects of matrix metalloproteinase (MMP) inhibitor LY52 on expression of MMP-2 and MMP-9 and invasive ability of human ovarian carcinoma cell line SKOV3].

BACKGROUND & OBJECTIVE: Enhanced expression and activation of matrix metalloproteinase-2 (MMP-2) and MMP-9 are associated with tumor progression, invasion, and metastasis. Using synthetic MMP inhibitors to block the proteolytic activity of these enzymes is a potential strategy of treating cancer. This study was to observe the inhibitory effects of LY52, a synthetic specific MMP inhibitor, on the expression of MMP-2 and MMP-9 and invasive ability of human ovarian carcinoma cell line SKOV3. METHODS: The inhibitory effect of LY52 on growth of SKOV3 cells was measured by MTT and clonogenic assays. The inhibitory effect of LY52 on the activity of gelatin was evaluated by spectrophotometry using succinylated gelatin as substrate. The inhibitory effect of LY52 on the expression of MMP-2 and MMP-9 was analyzed using SDS-PAGE zymography. The adhesive ability of SKOV3 cells to fibronectin (FN), laminin (LN), and matrigel was measured using MTT assay. The invasive ability of SKOV3 cells was assessed with a transwell cell culture chamber. RESULTS: LY52 had weak cytostatic effect on SKOV3 cells, the inhibitory rates were 10.54%-37.66% within 120 h incubation when the concentration was 10 microg/ml. LY52 inhibited gelatin degradation via suppressing the activities of gelatinases, the 50% inhibitory concentration (IC50) was 11.9 microg/ml. When treated with 0.1, 1, 10, 100, or 1,000 microg/ml LY52 for 24 h, the expression of MMP-2 in SKOV3 cells was suppressed by 10.66%-31.47%, and the expression of MMP-9 was suppressed by 22.56%-56.71%. When treated with LY52 for 1 h, the maximum inhibitory rates of adhesion of SKOV3 cells to FN, LN, and matrigel were 29.79%, 48.94%, and 50.92%, respectively. When treated with 0.1, 1, 10, 100, and 1,000 microg/ml LY52 for 24 h, the inhibitory rates of invasion of SKOV3 cells were 7.5%, 42.07%, 66.54%, 72.15%, and 82.84%, respectively. CONCLUSION: LY52 suppresses the invasion of SKOV3 cells via inhibiting the expression of MMP-2 and MMP-9.

Caffeic Acids↗
PubMed2005

Structure and bonding issues at the interface between gold and self-assembled conjugated dithiol monolayers.

Organic thiols have received extensive attention recently because of their relative stability and ease of examination compared to other potential molecular electronic materials. In this work, scanning probe microscopy (SPM) is used to study (i) the structural properties of self-assembled monolayers (SAMs) containing conjugated dithiols and (ii) the formation of the upper molecule-metal interface on dithiol SAMs. The top gold film is deposited either by thermal evaporation or by nano-transfer printing (nTP). Generally, the utility of thermal evaporation is limited because of Au diffusion through the SAMs. However, several dithiol SAMs are identified in this work that bond well to Au overlayers and act as satisfactory diffusion barriers. Coassembly of conjugated dithiols and alkanemonothiols is suggested as a route to obtain dithiols that are denser packed and more vertical (than is obtained from pure dithiol routes). High-yield nTP is demonstrated on coassembled SAMs. Advantages and limitations of different Au deposition and transfer techniques are compared on a variety of length scales.

Gold↗
PubMed2005

High-performance, stable organic thin-film field-effect transistors based on bis-5'-alkylthiophen-2'-yl-2,6-anthracene semiconductors.

The development of new organic semiconductors with improved electrical performance and enhanced environmental stability is the focus of considerable research activity. This communication presents the design, synthesis, and device stability data for novel bis-5'-alkylthiophen-2'yl-2,6-anthracene organic semiconductors. When incorporated into thin-film field-effect transistors, mobilities as high as 0.5 cm2/Vs and on/off current ratios greater than 107 are observed. We have investigated device stability in terms of both shelf life and operating lifetime. Devices incorporating the reported semiconductors display an average field-effect mobility of 0.4 cm2/Vs for DHTAnt and an on/off current ratio of 106 even after 15 months of storage. Furthermore, there is no decrease in performance during continuous operation of the devices over several thousand cycles.

Journal Article↗
PubMed2003

Solid-state synthesis of a conducting polythiophene via an unprecedented heterocyclic coupling reaction.

Prolonged storage ( approximately 2 years) or gentle heating (50-80 degrees C) of crystalline 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) affords a highly conducting, bromine-doped poly(3,4-ethylenedioxythiophene) (PEDOT), as confirmed by solid-state NMR, FTIR, CV, and vis-NIR spectroscopies. The novel solid-state polymerization (SSP) does not occur for 2,5-dichloro-3,4-ethylenedioxythiophene (DCEDOT), and requires a much higher temperature (>130 degrees C) for 2,5-diiodo-3,4-ethylenedioxythiophene (DIEDOT). X-ray structural analysis of the above dihalothiophenes reveals short Hal.Hal distances between adjacent molecules in DBEDOT and DIEDOT, but not in DCEDOT. The polymerization may also occur in the melt but is significantly slower and leads to poorly conductive material. Detailed studies of the reaction were performed using ESR, DSC, microscopy, and gravimetric analyses. SSP starts on crystal defect sites; it is exothermic by 14 kcal/mol and requires activation energy of approximately 26 kcal/mol (for DBEDOT). The temperature dependence of the conductivity of SSP-PEDOT (sigma(rt) = 20-80 S/cm) reveals a slight thermal activation. It can be further increased by a factor of 2 by doping with iodine. Using this approach, thin films of PEDOT with conductivity as high as 20 S/cm were fabricated on insulating flexible plastic surfaces.

Journal Article↗
PubMed2003

A one-step synthesis of a poly(iptycene) through an unusual Diels-Alder cyclization/dechlorination of tetrachloropentacene.

We have discovered the first reaction of a substituted pentacene molecule as a dienophile. A surprisingly clean Diels-Alder self-coupling of Cl4Pn leads to a novel ladder polymer, poly(iptycene), which can be converted to a conducting carbon at relatively low temperature (600-900 degrees C). Theoretical calculations of the former reaction suggest a biradical asymmetric mechanism, despite highly symmetric reactants.

Journal Article↗
PubMed2002

Retraction.

Explore the source record for details and available documents.

Retraction Notice↗
PubMed2002

In vivo characteristics of HPV-immortalized and carcinogen transformed oral keratinocytes.

PURPOSE: To characterize in vivo features of HPV-immortalized and carcinogen transformed oral keratinocytes. METHODS: The growth and squamous differentiation of IHGK (immortalized human gingival keratinocyte with HPV), IHGKN [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, (NNK)]-carcinogen transformed keratinocytes, and two head and neck squamous cell carcinoma (HNSCC) cell lines, HN30 and HN12, were tested by injecting these cells into SCID mice. The growth, histological features, and expression of PCNA, Involucrin, and high molecular weight keratin of the tumors formed were compared among these cell lines. RESULTS: All cell lines formed a palpable lesion at 2 weeks; however, only HN30 continued to grow. IHGK and IHGKN cells formed palpable nodules within 2 weeks with no further growth after 4 to 5 weeks, and no regression of the nodule was noted at 12 weeks. HN12 cells did not form tumor nodules unless these cells were co-injected with immortalized fibroblasts. Both IHGK and IHGKN cells formed a well-circumscribed epithelial lesion with islands of differentiated squamous cells bound by a myxoid matrix. Nests of basal-horny squamous cells centrally differentiated into anucleate squamous cells. IHGK and IHGKN nodules had more squamous differentiation than HN12 and HN30 and further differentiated over time. IHGK and IHGKN cells expressed differentiation (involucrin and high molecular weight keratin) and proliferation (PCNA) markers that suggest that IHGK and IHGKN behave as well-differentiated squamous lesions when compared with malignant HN12 and HN30 nodules. IHGK and IHGKN cells showed an initial growth phase followed by terminal differentiation, and then a phase characterized by regression and host inflammatory stage. CONCLUSIONS: The growth, histology, and expression of differentiation and proliferation markers of IHGK and IHGKN lesions into SCID mice demonstrate that these cells are endowed with a limited malignant potential. Our in vivo model with these intermediate cell lines can provide a short-term analysis for studying the biology of HNSCC progression and the activity of chemoprevention agents.

Animals↗
PubMed2002

Docetaxel induced gene expression patterns in head and neck squamous cell carcinoma using cDNA microarray and PowerBlot.

PURPOSE: The purpose is to identify gene expression patterns induced by docetaxelin head and neck squamous carcinoma (HNSCC) cells using high throughput techniques. EXPERIMENTAL DESIGN: HNSCC cells were treated with docetaxel or solvent. After mRNA extraction, cDNA fluorescent (Cy3 or Cy5)-labeled probes were synthesized. Then, Cy3 and Cy5-labeled samples were hybridized onto a microarray slide. The fluorescent images were scanned and analyzed for quantification. PowerBlot immunoblotting technique was used to measure protein expression level. Using this dual approach, we focused on genes in established pathways (cell cycle, apoptosis, angiogenesis, and signal transduction) of tumorigenesis and confirmed these results with conventional techniques. RESULTS: Using cDNA microarray, we found that docetaxel altered the expression of >100 genes in HNSCC cells. A total of 153 of 1191 genes was found to have altered expression in either HN12 (n = 102), HN30 (n = 72), or both (n = 21) by docetaxel. For the PowerBlot analysis, a subset of genes (n = 46) in the cDNA microarray analysis and an additional 98 genes in the cell cycle, apoptosis, angiogenesis, and signal transduction pathways were chosen. We found that PowerBlot data agreed with cDNA microarray in 65% of genes examined. The expression of a cell cycle inhibitor (p19) and promoters (cyclin A, cyclin B1, and cyclin E2F) were increased and decreased, respectively. Apoptosis induced by docetaxel was independent of p53 and, in part, related to increased Fas expression. Both vascular endothelial growth factor secretion and basic fibroblast growth factor expression were inhibited by docetaxel, whereas thrombospondin-1 expression was increased by docetaxel. Epidermal growth factor receptor, activated epidermal growth factor receptor, and activated c-Jun NH(2)-terminal kinase expression was lowered by docetaxel. Activated extracellular signal-regulated kinase was elevated by docetaxel, but not total extracellular signal-regulated kinase levels. CONCLUSIONS: The identification of altered gene expression induced by docetaxel demonstrates additional biological activity in HNSCC cells, and the altered expression of these genes may serve as potential biomarkers to both predict clinical activity and provide information regarding potential efficacy of adding novel agents.

Annexin A5↗
PubMed2002

[Clinical immunological study on prevention and treatment of chronic pyelonephritis with yishenkang granule].

OBJECTIVE: To investigate the relationship between chronic pyelonephritis (CPN) and immune function, and the therapeutic mechanism of Yishenkang granule (YSKG). METHODS: One hundred and twenty patients of CPN were divided into 3 groups randomly, the YSKG group (treated with YSKG), the control A group (treated with Sanjin tablet) and the control B group (treated with western medicine). Serum levels of immunoglobulin (Ig), complement 3 (C3), interleukin-2 (IL-2), peripheral T-lymphocyte subsets, and urinary secretory immunoglobulin A (sIgA) were determined before and after treatment with monoclonal antibody assay, agar diffusion method, radioimmunoassay (RIA), and radioimmuno-equilibrium method, and compared with normal control. RESULTS: There were disorders of T-lymphocyte subsets in CPN, lowering of serum Ig, C3 and urinary sIgA, and increase of blood IL-2 (P < 0.05 or P < 0.01). These abnormalities could be normalized after YSKG treatment. CONCLUSION: Functional disorders of cellular and humoral immunity exist in CPN patients of chronic stage, YSKG could correct the immune functional disorder, control the recurrence of CPN effectively and alleviate the immunopathological damage.

Adult↗
PubMedDate not supplied

Caffeoyl pyrrolidine derivative LY52 inhibits tumor invasion and metastasis via suppression of matrix metalloproteinase activity.

BACKGROUND: LY52 is a caffeoyl pyrrolidine derivative designed to fit and extend into the active pocket of matrix metalloproteinase (MMP). In this study, the effects of LY52 on MMP-2 and MMP-9 activities and tumor invasion and metastasis were examined. MATERIALS AND METHODS: MMP expression in SKOV3 cells was analyzed by gelatin zymography. The anti-invasion and anti-metastasis abilities of LY52 were evaluated with penetration of SKOV3 cells through Matrigel-coated membrane in vitro and pulmonary metastasis of Lewis lung carcinoma in mice, respectively. RESULTS: LY52 significantly blocked the proteolytic activity of gelatinase. Gelatin zymography revealed that MMP-2 and MMP-9 expressions in SKOV3 cells were reduced in the presence of LY52. LY52 also suppressed SKOV3 cell invasion in vitro. Furthermore, a significant inhibition of pulmonary metastasis of Lewis lung carcinoma cells was observed in LY52-administrated mice. CONCLUSION: LY52 might suppress invasion and metastasis of carcinoma cells via inhibition of MMP-2 and MMP-9 proteolytic activities.

Animals↗