Biomedical subjects

Yi Ding

Publications and source records attributed to Yi Ding.

At least 55 records · Page 3Linked to original sources

PubMed2005

Lead biosorption and desorption by intact and pretreated spirulina maxima biomass.

In order to search for locally available and untried biomaterials in China with high removal capacity of heavy metals from wastewater, the feasibility of Spirulina maxima as biosorbent for lead removal and recovery from aqueous solution was investigated. The lead biosorption was studied by using intact biomass and pretreated biomass of S. maxima. The effects of operational conditions (e.g. pH, contact time, biomass concentration etc.) on lead biosorption were investigated. The biosorption was solution pH dependent and the maximum adsorption was obtained at a solution pH of about 5.5. The adsorption equilibrium was reached in 60 min. The biosorption followed the Freundlich isotherm model. The maximum removal ratios of lead were about 84% in intact biomass and 92% in pretreated biomass. The lead adsorbed could be desorbed effectively by 0.1 M nitric acid, EDTA and hydrochloric acid. The results in this study indicated that pretreated biomass of S. maxima was a promising candidate for removing lead from wastewater.

Adsorption↗

PubMed2005

One new benzyldihydrophenanthrene from Arundina graminifolia.

A novel benzyldihydrophenanthrene named arundinaol has been isolated from the rhizoma of Arundina graminifolia. The structure of has been elucidated as 7-hydroxy-1-(p-hydroxybenzyl)-2,4-dimethoxy-9,10-dihydrophenanthrene on the basis of physical and chemical evidence and spectral analysis.

Orchidaceae↗

PubMed2005

Method to detect functional estrogen receptor expression using estrogen receptor probing compound.

A novel method to detect functional estrogen receptor expression with estrogen receptor probing compound (ERPC) has been established. ERPC is composed of estradiol-BSA-biotin. ERPC can be used to detect functional estrogen receptor expression in both Western blot and immunohistochemistry. ERPC based techniques are non-radioactive, sensitive, relatively inexpensive, and can be used with all species. The use of both ERPC and ERalpha- or ERbeta-specific antibodies provides complementary information in characterizing estrogen receptors' expression and functional binding to ligand.

Blotting, Western↗

PubMed2005

The effects of Ananas comosus L. leaves on diabetic-dyslipidemic rats induced by alloxan and a high-fat/high-cholesterol diet.

The aim of this study is to demonstrate the effects of Ananas comosus L. leaves on diabetic-dyslipidemic rats. Hypoglycemic and hypolipidemic activities of the ethanolic extract of Ananas comosus L. leaves (EEACL) were evaluated in normal and alloxan-induced diabetic rats by oral glucose tolerance test and an olive oil load test. Anti-diabetic, anti-hyperlipidemic and anti-oxidative activities of EEACL were also investigated in diabetic-dyslipidemic rats induced by alloxan and a high-fat/high-cholesterol diet. EEACL at the dose of 0.40 g/kg significantly inhibited the increase in blood glucose in diabetic rats in oral glucose tolerance test, but did not cause any hypoglycerimic activity in normal rats. It also significantly inhibited the increase in postprandial triglycerides (TG) levels in both normal and diabetic rats in olive oil load test. After 15 days of treatment of diabetic dyslipidemic rats, EEACL significantly decreased blood glucose (-51.0%, P < 0.01), TG (-50.1%, P < 0.01), TC (-23.3%, P < 0.01), LDL-c (-47.9%, P < 0.01) and glycated albumin (-25.4%, P < 0.01) levels, significantly increased serum high-density lipoprotein cholesterol levels (66.2%, P < 0.01) and prevented lower body weight of diabetes (11.8%, P < 0.05), significantly lowered lipid peroxidation productions of blood (-27.8%, P < 0.01), brain (-31.6%, P < 0.05), liver (-44.5%, P < 0.01) and kidneys (-72.2%, P < 0.05) compared with those in untreated diabetic dyslipidemic rats. These data suggest that EEACL has anti-diabetic, anti-dyslipidemic and anti-oxidative activities, which may be developed into a new plant medicine for treatment of diabetes and its complications.

Ananas↗

PubMed2005

E1A sensitizes cancer cells to TRAIL-induced apoptosis through enhancement of caspase activation.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to induce apoptosis of cancer cells. Sensitization of cancer cells to TRAIL, particularly TRAIL-resistant cancer cells, could improve the effectiveness of TRAIL as an anticancer agent. The adenovirus type 5 E1A that associates with anticancer activities including sensitization to apoptosis induced by tumor necrosis factor is currently being tested in clinical trials. In this study, we investigated the sensitivity to TRAIL in the E1A transfectants ip1-E1A2 and 231-E1A cells and the parental TRAIL-resistant human ovarian cancer SKOV3.ip1 and TRAIL-sensitive human breast cancer MDA-MB-231 cells. The results indicated that the percentage of TRAIL-induced apoptotic cells was significantly higher in the E1A transfectants of both cell lines than it was in the parental cell lines. To further investigate the cellular mechanism of this effect, we found that E1A enhances TRAIL-induced activation of caspase-8, caspase-9, and caspase-3. Inhibition of caspase-3 activity by a specific inhibitor, Z-DEVD-fmk, abolished TRAIL-induced apoptosis. In addition, E1A enhanced TRAIL expression in ip1-E1A2 cells, but not in 231-E1A cells, and the anti-TRAIL neutralizing antibody N2B2 blocked the E1A-mediated bystander effect in vitro. Taken together, these results suggest that E1A sensitizes both TRAIL-sensitive and TRAIL-resistant cancer cells to TRAIL-induced apoptosis, which occurs through the enhancement of caspase activation; activation of caspase-3 is required for TRAIL-induced apoptosis; and E1A-induced TRAIL expression is involved in the E1A-mediated bystander effect. Combination of E1A and TRAIL could be an effective treatment for cancer.

Adenovirus E1A Proteins↗

PubMed2005

Soluble EphB4 regulates choroidal endothelial cell function and inhibits laser-induced choroidal neovascularization.

PURPOSE: The purpose of this study was to evaluate the effect of a soluble monomeric form of the EphB4 extracellular domain (sEphB4) on choroidal endothelial cell (CEC) migration and tube formation and on experimental laser-induced choroidal neovascularization (CNV). METHODS: EphrinB2 and EphB4 expression in CECs was investigated by Western blot analysis and immunohistochemistry. Effects of sEphB4 (0.5-3 microg/mL) on CEC migration were evaluated with a modified Boyden chamber assay. Tube formation was assayed in CEC cultures in collagen gel. CNV was induced in rats by laser photocoagulation. The effects of intravitreal injection of sEphB4 on CNV development were evaluated at day 14 by fluorescein angiography (FA), confocal volumetric analysis of isolectin-B4 labeled flatmounts, and histologic examination of CNV membranes. RESULTS: CEC cells express both EphB4 and EphrinB2, according to Western blot analysis. Immunohistochemical sections of rat eye showed immunoreactivity for both EphB4 and EphrinB2 in the choroidal endothelium. sEphB4 reduced CEC migration in response to vascular endothelial growth factor (P < 0.01). Similarly, sEphB4 inhibited CEC tube formation in a dose-dependent manner. EphB4, and to a lesser extent EphrinB2, were detected on vascular channels within laser-induced CNV membranes. Intravitreal injection of sEphB4 inhibited laser-induced CNV formation. CNV membranes showed a reduction in leakage score (P < 0.05), and membrane volumes were reduced in size (P < 0.05). Histologic analysis revealed that vascularity was reduced in sEphB4-treated membranes. CONCLUSIONS: Recombinant soluble monomeric EphB4 exerts an inhibitory effect on choroidal angiogenesis in vitro and in vivo. It should be further evaluated for its potential as a novel therapy for CNV.

Animals↗

PubMed2005

[Phenanthrene constituents from rhizome of Arundina graminifolia].

OBJECTIVE: To isolate and elucidate the constituents from rhizome of Arundina graminifolia. METHOD: Theconstituents were extracted with 95% alcohol and isolated by chromatography on silica gel, Sephedax LH-20. The structures were determined by UV, IR, NMR and MS spectral analysis. RESULT: Five phenanthrene constituents were identified as 7-hydroxy-2, 4-dimethoxy-9, 10-dihydrophenanthrene( I ), 4, 7-dihydroxy-2-methoxy-9, 10-dihydrophenanthrene ( II ), 2, 7-dihydroxy-4-methoxy-9, 10-dihydrophenanthrene ( III ), 7-hydroxy-2-methoxyphenanthrene-1,4-dione ( IV ), 7-hydroxy-2-methoxy-9, 10-dihydrophenanthrene-1,4-dione (V), respectively. CONCLUSION: All compounds were isolated from rhizome of A. graminifolia for the first time.

Orchidaceae↗

PubMed2005

[Effects of triptolide on migration of vascular endothelial cells].

OBJECTIVE: To investigate the inhibitory effects of triptolide on the migration, gene and protein expression of urokinase-type plasminogen activator (u-PA) of endothelial cells (ECs) cultured in vitro and to elucidate the anti-angiogenic mechanism of triptolide. METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured in vitro and the passage 3 cells were treated with triptolide (0, 5, 10, 20, 30 microg/L). Three-dimensional culture system was used to assess the effect of triptolide on the migration of HUVECs. Real time quantitive reverse transcription polymerase chain reaction and immunohistochemical assay were applied to detect gene and protein expression of u-PA. RESULTS: Triptolide decreased the migration activity and suppressed the expression of u-PA of HUVECs at the gene and protein level. CONCLUSION: Triptolide could inhibit the migration of ECs by reducing the gene and protein expression of u-PA. These may contribute to an elucidation of the mechanism by which triptolide inhibits the angiogenesis.

Angiogenesis Inhibitors↗

PubMed2005

[Effect of triptolide on expression of urokinase-type plasminogen activators in vascular endothelial cells].

BACKGROUND & OBJECTIVE: It has been showed that triptolide (T10) has antitumor activities. This study was to observe the inhibitory effects of T10 on proliferation of vascular endothelial cells and expression of urokinase-type plasminogen activator (u-PA), and to elucidate the antiangiogenic mechanism of T10. METHODS: Human umbilical vein endothelial cells were cultured in vitro for 3 generations, and treated with T10 (0, 5, 10, 20, and 30 microg/L), or dexamethasone (300 mg/L) as control. Cell count and 3H-TDR incorporation were used to observe cell proliferation. The chick embryo chorioallantoic membrane (CAM) test was carried out to observe the effect of T10 on angiogenesis. Immunohistochemistry and real-time quantitive reverse transcription-polymerase chain reaction (RT-PCR) were used to detect protein and mRNA levels of u-PA. RESULTS: T10 inhibited the proliferation of umbilical vein endothelial cells in a dose-dependent manner; inhibitory rate of endothelial cells was 28.93% after treatment of 5 microg/L of T10. T10 significantly reduced angiogenesis in CAM, even at the concentration of 5 microg/L (P<0.05). T10 decreased protein and mRNA levels of u-PA in endothelial cells in a dose-dependent manner; the protein level of u-PA was reduced by 41.05% after treatment of 5 microg/L of T10. CONCLUSION: T10 could inhibit the proliferation of human umbilical vein endothelial cells and expression of u-PA, which may contribute to its antiangiogenic activity.

Angiogenesis Inhibitors↗

PubMed2005

[Studies on chemical constituents from pine cone of Pinus armandii].

OBJECTIVE: To study chemical constituents from pine cone of Pinus annandii. METHOD: The constituents were isolated by chromatographic method and the structures were identified on the basis of spectral analysis. RESULT: Seven compounds were identified as sandaracopimaric acid (I), isodextropimaric acid (II), 12-hydroxyabietic acid (III), dehydroabietic acid (IV), 15-hydroxydehydroabietic acid (V), beta-sitosterol (VI) and daucosterol (VII). CONCLUSION: Compounds I-IV were isolated from this plant for the first time.

Abietanes↗

PubMed2005

[Dynamic release of tinidazole from the degradable PLLA-tinidazole blend gel].

OBJECTIVE: To determine the dynamic release of tinidazole from the degradable poly-lactic acid (PLLA)-tinidazole blend gel (a periodontal local drug delivery) by high-performance liquid chromatography (HPLC) in vitro and to observe the polylactic acid (as a vector of tinidazole) how to affect the release of tinidazole. METHODS: HPLC analysis was conducted. The operating conditions were C18-ODS-A column, water-methanol-acetic acid as mobile phase at a flow rate of 1.5 ml/min and a detection wavelength at 310 nm and a column temperature at 30 degrees C. RESULTS: The retention time of tinidazole was about 12 min. There was good linear relationship between the concentrations of tinidazole in blend gel and their peak areas in the ranges of 5 - 500 mg/L. The regression reaction was y = 0.836 + 8.452 2 x 10(-5) x (r = 0.998 6). RSD was 0.2%. Polylactic acid had no influence on the determination of tinidazole. The daily average release of tinidazole was 5.60%. The cumulative release of tinidazole was about 78.40% in 14 days. CONCLUSION: The in vitro drug release analysis is an useful method in evaluating the performance of local drug delivery system. HPLC analysis is a simple and accurate method with good reproducibility.

Chromatography, High Pressure Liquid↗

PubMed2005

[Effects of triptolide on anti-angiogenesis by reducing expression of urokinase plasminogen activator].

In order to unveil the anti-angiogenic mechanism of triptolide, we investigated the effects of triptolide on the proliferation, migration, angiogenesis and u-PA expression of cultured HUVECs. MTT assay found that triptolide could inhibit the proliferation of HUVECs, and three-dimensional culture system revealed that triptolide could curb the migration of HUVECs. The chick embryo chorioallantoic membrane (CAM) test showed that triptolide could inhibit angiogenesis. Real time quantitive RT-PCR showed the expression of u-PA of HUVECs was down-regulated by triptolide. Therefore, triptolide may inhibit the proliferation and migration of endothelial cell by way of reducing the expression of u-PA. These findings may conduce to the elucidation of the anti-angiogenic mechanism of triptolide.

Angiogenesis Inhibitors↗

PubMed2005

[Ecological footprint in building green university].

Ecological footprint is one of the best indexes to evaluate the level of green university. The approaches of ecological footprint are made up of compound approach and component approach. This paper introduces the basic principle and algorithm of the componential approach of ecological footprint, taking Northeastern University as an example and using this approach in the research of campus. Result show that the ecological footprint of Northeastern University 2003 was 24 787hm2, needing the productive land of ecology about 25 000hm2 support all kinds of consumption of the school and absorb the offal. The ecological efficiency of the school was 0.94cap/hm2. In the ecological footprints, the energy's footprints is the largest, it accounted for more than 2/3 of the total footprints, the next are food consumption and solid rubbish.

China↗

PubMed2005

[Studies on chemical constituents of Pinus armandii].

AIM: To study chemical constituents from pine cone of Pinus armandii Franch. METHODS: The constituents were isolated by chromatographic method and the structures were identified on the basis of spectral analysis. RESULTS: Four compounds were identified as 7-oxo-12alpha, 13beta-dihydroxyabiet-8(14)-en18-oic acid (I), 7-oxo-13beta-hydroxyabiet-8 (14)-en-18-oic acid (II), 8 (14)-podocarpen-13-on-18-oic acid (III) and lambertianic acid (IV). CONCLUSION: Compound I is a new diterpenoid and compounds II, III were isolated from this plant for the first time.

Carboxylic Acids↗

PubMed2005

[Comparative analysis of sequences of the 5S rDNA NTS in wild close relatives of barley from Tibet of China].

Tibet is a center of distribution and differentiation of genus Hordeum in China,and has a great deal of species resource. The sequences of the nontranscribed intergenic spacer (NTS) region of 5S nuclear ribosomal DNA was studied in 18 varieties of the close relative of wild barley (Hordeum spontaneum) from different geographical regions in Tibet and Turkmenistan. These sequences were determined by sequencing the clones of PCR products. Alignment of sequences revealed that the 5S rDNA NTS contained two comparatively conservative regions, A and B, and a variable TAG repeat (V). The number of TAG repeats varies from 4-17, also including several transitions and conversions (TAG-->TCG, TAG-->TAC). The total size of the conservative regions was from 168 -169 bp, and the sequence length variation was only 1 bp. The GC content (%) of the conservative sequence was 43.8% and the homologous of that nearly 98.2% -100%. The number of variable sites was 12 (7.1%). In general, there were more transitions than conversions in the variation sites,and the ratios of transition/conversion were 1.0 - 2.0. NTS polymorphism of 5S rDNA was mainly determined by polymorphism of TAG repeats. The molecular system-tree showed that the NTS should be a useful marker to classify the accessions in Hordeum.

Base Sequence↗

PubMed2005

[Long term survival results in advanced prostate cancer treated with combined androgen blockade].

OBJECTIVE: To understand long-term survival rate after combined androgen blockade (CAB) in patients with advanced prostate cancer. METHODS: A selected population of 59 patients with advanced prostate cancer were treated with CAB. 28.81% (17/59) of patients had clinical locally advanced disease (stage T3-4N0M0), and 45.76% (27/59) of patients had metastatic disease (stage TxNxM+). Overall, patients were followed for a median of 62 (range 6-136) months. RESULTS: Of the 59 patients with advanced prostate cancer, 3-year, 5-year and 7-year overall survival rates were 79.36%, 61.46% and 49.15%, respectively. The 5-year survival rate were 80.77% and 32.65% for clinical locally advanced disease and metastatic disease. Specifically, men with poorly differentiated prostate cancer had a 5-year survival of only 30% when compared with men with well-differentiated prostate disease who had a 5-year survival of 86.21%. CONCLUSION: Based on these findings, men with poorly differentiated cancer, stage T3c-4NxMx or TxNxM+ and PSA level above 30 microg/L had a high probability of dying from their advanced prostate cancer.

Aged↗

PubMed2005

[Expression of human papillomavirus 16 E7 DNA in patients with colorectal adenocarcinoma].

The relationship between Human papillomavirus (HPV) 16 infection and the natural course of colorectal adenocarcinoma has not been fully defined. In this study, the HPV 16 E7 DNA was detected in 82 patients with primary colorectal adenocarcinoma to study the relationship between HPV 16 infection and colorectal carcinoma. Samples were taken from both the tumors and the adjacent normal mucosa in the same patient. Polymerase chain reaction (PCR) was used to amplify the HPV16 E7 DNA fragment. The PCR products were gel-purified and sequenced for HPV genotyping. DNA sequence analysis indicated that PCR product was 297 bp. It was the equivalent of 562-858th pairs in the HPV 16 primitive sequences. Our results showed HPV16 E7 DNA expression was significantly higher in colorectal carcinoma (42/82) than in adjacent normal mucosa (4/82). The correlation was found between HPV16 E7 expression and tumor's location; the positive rate was 18.18% in the ascending colon carcinoma group and 64.10% in the rectal carcinoma group. High HPV16 E7 expression was also associated with lower Dukes stage (P < 0.01). These results indicated that there was correlation between colorectal adenocarcinoma and HPV 16 infection. HPV16 infection was relatively higher in the colorectal carcinoma and rare in the adjacent normal mucosa. Specimens expressing higher levels of HPV 16 E7 DNA were associated with lower Dukes stage and more distal location.

Adenocarcinoma↗

PubMed2005

[Studies on chemical constituents from flowers of Apocynum venetum].

OBJECTIVE: To study the chemical constituents of the flowers of Apocynum venetum. METHOD: Chromatographic methods were used to isolate compounds from the flowers of A. venetum and spectral methods were used to identify the structures of the isolated compounds. RESULT: Seven compounds, kaempferol (I), quercetin (II), quercetin-3-O-beta-D-glucoside (III), kaempferol-3-O-beta-D-glucoside (IV), vanillic acid (V), baimaside (VI), daucosterol (III), were isolated from the flowers of A. venetum. CONCLUSION: Compound I, V, VI, VII were obtained from this plant for the first time.

Apocynum↗