Biomedical subjects

Ying Zhao

Publications and source records attributed to Ying Zhao.

At least 73 records · Page 4Linked to original sources

PubMed2004

[Influence of seven absorption enhancers on nasal mucosa--assessment of toxicity].

OBJECTIVE: To study the influence of seven different absorption enhancers on nasal mucosa. METHODS: By testing last time of ciliary movement, velocity of ciliary movement, ciliary structural and specific cellular changes of nasal mucosa the influence of seven different absorption enhancers on nasal mucosa. RESULTS: The effect on lasting time of ciliary movement was 1%SDS>1%SDC>1%Brij35>5%Tween80>0.1%EDTA>5%HP-beta-CD>1%lecithin the effect on velocity of ciliary movement 1%Brij35>1%SDC>1%SDS>0.1%EDTA>1%lecithin>5%Tween80>5%HP-beta-CD,and the effect on ciliary structural and specific cellular changes of nasal mucosa 1%SDS approximately 1%SDC approximately 1%Brij35>5%Tween80>0.1%EDTA approximately 5% HP-beta-CD approximately 1%lecithin. CONCLUSION: The three methods have good correlation.

Absorption↗

PubMed2004

[Preparation and properties of 5-fluorouracil-loaded chitosan microspheres for the intranasal administration].

OBJECTIVE: To study the preparation technique and release characteristic of 5-fluorouracil loaded chitosan microspheres for the intranasal administration. METHODS: Using the liquid paraffin as the oil phase,and span-80 as the emuifier; 5-fluorouracil-loaded chitosan microspheres were achieved by emulsion-chemical crosslink technique. The orthogonal experimental design was applied to optimize the preparation procedure. Dynamic dialysis method was used to determine the releasing characteristic of microspheres in vitro and it influencing factors. Swelling behavior was expressed by swelling ratio. The degree of mucoadhesion was investigated by determining the mucociliary transport rate(MTR) of the microparticle across a frog palate. RESULTS: Microspheres with a good shape and narrow size distribution were prepared. The average diameter was (43+/-4) microm. The drug loading was 38.5%+/-1.0%. The entrapment efficiency was 79.0%+/-1.8%. The drug release profile in vitro could be described by Higuichi equation Q=0.1035t(1/2)+0.0284 (r=0.9965). Chitosan had good mucoadhesive property and caused a significant reduction in MTR(P<0.01). CONCLUSION: The optimized preparation technique is stable and has a high entrapment efficiency. So it could be used to prepare 5-fluorouracil-loaded chitosan microspheres for the intranasal administration. Chitosan is a good material for nasal preparation and has prospective development in the pharmaceutical field.

Adhesiveness↗

PubMed2004

Phosphatase of regenerating liver-3 promotes motility and metastasis of mouse melanoma cells.

Recent reports suggested that phosphatase of regenerating liver (PRL)-3 might be involved in colorectal carcinoma metastasis with an unknown mechanism. Here we demonstrated that PRL-3 expression was up-regulated in human liver carcinoma compared with normal liver. PRL-3 was also highly expressed in metastatic melanoma B16-BL6 cells but not in its lowly metastatic parental cell line, B16 cells. B16 cells transfected with PRL-3 cDNA displayed morphological transformation from epithelial-like shape to fibroblast-like shape. PRL-3-overexpressed cells showed much higher migratory ability, which could be reversed by specific anti-sense oligodeoxynucleotide and the phosphatase inhibitors sodium orthovanadate or potassium bisperoxo oxovanadate V. Meanwhile, the expression of the catalytically inactive PRL-3 mutations (D72A or C104S) significantly reduced the cell migratory capability. In addition, PRL-3 transfectants demonstrated altered extracellular matrix adhesive property and up-regulated integrin-mediated cell spreading efficiency. Furthermore, we confirmed that PRL-3 could facilitate lung and liver metastasis of B16 cells in an experimental metastasis model in mice, consistent with accelerated proliferation and growth rate both in vitro and in vivo. Together, these observations provide convincing evidence that PRL-3 truly plays a causal role in tumor metastasis.

Animals↗

PubMed2004

Helicobacter pylori heat-shock protein 60 induces inflammatory responses through the Toll-like receptor-triggered pathway in cultured human gastric epithelial cells.

Contact between Helicobacter pylori and gastric epithelial cells results in activation of NF-kappaB followed by secretion of interleukin (IL)-8. However, host-cell receptor(s) and their ligands involved in H. pylori-related IL-8 production have yet to be fully defined. In this study, the interaction between Toll-like receptors (TLRs), which are host receptors for pathogens involved in the innate immune response, and heat-shock protein (HSP) 60, an immune-potent antigen of H. pylori, was examined during H. pylori-induced IL-8 secretion in vitro. Recombinant H. pylori HSP60 (rHpHSP60) was prepared and added to cultured KATO III human gastric epithelial cells with or without pre-incubation with mouse monoclonal anti-TLR2 or anti-TLR4 antibodies. IL-8 mRNA expression and IL-8 protein release were analysed by Northern blotting and immunoassay. Involvement of NF-kappaB activation was analysed immunocytochemically by anti-NF-kappaB p65 antibody and ammonium pyrrolidinedithiocarbamate (PDTC), an inhibitor of NF-kappaB-mediated transcriptional activation. rHpHSP60 induced IL-8 mRNA expression and IL-8 secretion in a dose-dependent manner in KATO III cells. Anti-TLR2 antibody inhibited rHpHSP60-induced IL-8 secretion by 75 %, and anti-TLR4 antibody inhibited it by 30 %. rHpHSP60 induced nuclear translocation of NF-kappaB p65, which was inhibited by pretreatment with anti-TLR2 antibody. Treatment with PDTC significantly decreased the secretion of IL-8 induced by rHpHSP60. These findings suggest that H. pylori HSP60 activates NF-kappaB and induces IL-8 production through TLR-triggered pathways in gastric epithelial cells. Thus, it is possible that H. pylori HSP60 and TLR interaction in host cells contributes to the development of gastric inflammation caused by H. pylori infection.

Animals↗

PubMed2004

Determination of threshold concentrations of allergens and evaluation of two different histamine concentrations in canine intradermal testing.

The purpose of this study was to determine the optimal histamine concentration and allergen threshold concentrations for canine intradermal testing. Thirty healthy dogs were tested using two different concentrations of histamine and four different concentrations of each allergen. The optimal histamine concentration was determined to be 1:10 000 w/v. The threshold concentration was at least 1750 PNU/mL for all tested grasses, weeds, trees, moulds and insects, except for fleas which was as least 1:500 w/v. For Dermatophagoides pteronyssinus, the optimal threshold concentration was 250 PNU/mL, whereas for Dermatophagoides farinae and Tyrophagus putrescentiae, it was 100 PNU/mL. Threshold concentration for all epidermals except human dander was at least 1250 PNU/mL. The optimal threshold concentration for human dander was 300 PNU/mL. Our results suggest that the currently used 1:100 000 w/v concentration of histamine and the 1000 PNU/mL concentration for most grasses, weeds, trees, moulds, epidermals and insects may not be appropriate for canine intradermal testing.

Allergens↗

PubMed2004

Helicobacter pylori infection targets adherens junction regulatory proteins and results in increased rates of migration in human gastric epithelial cells.

The human gastric pathogen Helicobacter pylori attaches to antral epithelial cells in vivo. Cultured human antral epithelial cells, AGS and NCI-N87 cell lines, were grown in the absence or presence of H. pylori and compared with respect to gene transcript levels, protein expression, organization of the actin cytoskeleton, and the regulation of cell migration. The Clontech Neurobiology array detected differentially expressed transcripts, while Western blots were used to investigate related changes in protein levels. Infection with H. pylori consistently upregulated annexin II, S100 A7, Rho-GTP, and IQGAP-1, whereas SSTR-1 was downregulated upon H. pylori infection. In the adherens junction, E-cadherin and IQGAP-1 were translocated from the plasma membrane to intracellular vesicles. The primary and NCI-N87 cells were similar with respect to cell-cell and cell-matrix adhesion and cell migratory behavior; in contrast the AGS cells were significantly different from the primary gastric epithelial cell preparations, and thus caution must be used when using this cell line for studies of gastric disease. These studies demonstrate a correlation between H. pylori infection and alterations to epithelial cell adhesion molecules, including increased levels of Rho-GTP and cell migration. These data indicate that destabilizing epithelial cell adherence is one of the factors increasing the risk of H. pylori-infected individuals developing gastric cancer.

Adherens Junctions↗

PubMed2004

Astilbin prevents concanavalin A-induced liver injury by reducing TNF-alpha production and T lymphocytes adhesion.

The aim of this study was to evaluate the effect of astilbin on concanavalin A (Con A)-induced hepatitis, a T cell-dependent model of liver injury. Con A administration resulted in a severe liver injury in mice, with a strong increment in spleen cell adhesion and liver infiltration of T cells, as well as in tumour necrosis factor (TNF)-alpha production. Against this liver injury, astilbin significantly inhibited the elevation in transaminase activity, reduced the TNF-alpha production, and improved the histological changes, including inflammatory infiltration, hepatocyte necrosis and degeneration and Kupffer cell hyperplasia. In addition, astilbin inhibited the adhesion of spleen cells and purified T lymphocytes isolated from the liver-injured mice to fibronectin, laminin and type IV collagen.Moreover, the adhesion of human Jurkat T cells to endothelial cell line ECV-304 was also inhibited by astilbin. These results suggest that the improvement of the T cell-mediated liver injury by astilbinmay be related to the reduction in TNF-alpha production and in T cell adhesion to extracellular matrices and endothelial cells.

Animals↗

PubMed2004

Fumigaclavine C improves concanavalin A-induced liver injury in mice mainly via inhibiting TNF-alpha production and lymphocyte adhesion to extracellular matrices.

Fumigaclavine C, an alkaloidal metabolite, was produced by Aspergillus fumigatus (strain No. CY018). This study examined the effect of this compound on concanavalin A (Con A)-induced liver injury in mice, a T cell-dependent model of liver damage. Con A administration resulted in severe liver injury, T lymphocyte activation and a strong increment in spleen cell adhesion, as well as in tumour necrosis factor-alpha (TNF-alpha) production. Against this liver injury, the intraperitoneal administration of fumigaclavine C dose-dependently inhibited the elevation in transaminase activity, TNF-alpha production in serum and the histological changes, including inflammatory infiltration, hepatocyte necrosis and degeneration and Kupffer cell hyperplasia. In addition, this compound in-vitro also inhibited the proliferation of spleen cells induced by Con A, and reduced their IL-2 and TNF-alpha production. Moreover, the intraperitoneal administration of fumigaclavine C inhibited the potential of spleen cells isolated from the liver-injured mice to adhere to fibronectin, laminin and type IV collagen. These results suggest that the improvement of this T cell-mediated liver injury by fumigaclavine C may be related to the inhibition of lymphocyte activation, proliferation and adhesion to extracellular matrices as well as the reduction in TNF-alpha production.

Alkaloids↗

PubMed2004

Cloning and characterization of testis-specific spermatogenesis associated gene homologous to human SPATA4 in rat.

Rat SPATA4 gene, homologue to the human and mouse SPATA4 gene, expressed specifically in the rat testis was cloned by informatics analysis. The cDNA mapped to chromosome 16 in the rat genome is made up of 6 exons and the exon-intron boundaries obey to the AG/GT rule. The gene contains a 972 bp open reading frame encoding 323 amino acid sequences with theoretical molecular weight of 36.64 KD and isoelectric point of 9.65. One CpG island is located in the gene from site -200 to +198. A typical promoter is also predicted from site -630 to +101. According to the computer-aided analysis of the putative protein encoded by the rat SPATA4, no transmembrane region and no signal peptides are found in the protein. Multi-tissue RT-PCR results show that the SPATA4 gene is expressed specifically in the testis only. Moreover, the expression of SPATA4 occurs in a development stage-dependent pattern. According to the RT-PCR results, no expression of SPATA4 is detected until the rat is 30 d old after birth. The amount of SPATA4 mRNA increases from 30-d to 65-d-old rat and then keeps stable after that. In conclusion, this study proves the conservation of SPATA4 in mammalian animals and predicts its important role in spermatogenesis.

Amino Acid Sequence↗

PubMed2004

[Comparing two kinds of labeled streptavidin biotin methods and selecting the best antigen retrieval method].

OBJECTIVE: To compare two kinds of labeled streptavidin biotin(LsAB) methods and provide the optimal method of antigen retrieval. METHODS: The alkaline phosphatase(AP) LsAB method and the horseradish peroxidase (HRP) LsAB method were used to stain anti-tryptase in paraffin embedding tissue of patients with chronic obstructive pulmonary disease (COPD) and their staining effects were compared. The antigens were repaired by high pressure cooking, tryptin digestion and microwave, and the repairing effects were compared. RESULTS: The backgrounds of stained sections were more distinct and the color distinction of nucleus and positive signal were brighter by AP-LsAB, compared with those by HRP-LsAB; the repairing effect of high pressure cooking was better than the repairing effect of tryptin digestion and than that of microwave. CONCLUSION: AP-LsAB and high pressure cooking retrieval were recommended for use in immunohistochemical staining of pulmonary inflammatory tissue.

Alkaline Phosphatase↗

PubMed2004

[Eye socket reconstruction with free radial forearm flap in anophthalmic orbital syndrome and contracted eye socket].

OBJECTIVE: To assess the effect of eye socket reconstruction with free radial forearm flap. METHODS: Reconstructive procedures were performed in 7 patients underwent orbital exenteration for malignant tumors and in 9 patients underwent enucleation and postoperative irradiation of the orbit for the treatment of retinoblastoma. These patients were suffered from anophthalmic orbital syndrome and contractive eye socket. A microvascular surgical technique with a free radial forearm flap was adopted. Hydroxyapatite implant was inserted as an intraorbital implantation. RESULTS: All patients were followed up for 6 months to 5 years and good cosmetic results were obtained. A large eye socket was achieved permanently. Artificial eye could be fitted with satisfactory results. CONCLUSION: Free radial forearm flap transplantation offers a useful option for the treatment of anophthalmic orbital syndrome.

Adolescent↗

PubMed2004

[The distribution of mast cells in benign and malignant prostate lesions and its biologic significance].

OBJECTIVE: To study the distribution profile of mast cells in benign and malignant prostate lesions and its biologic significance. METHODS: Fifty-three prostate specimens collected from 2000 through 2002 were examined, and the distribution of mast cells were analyzed. The paraffin sections were stained with anti-human mast cell tryptase immunohistologically. The numbers of cells stained with positive results in ten high-power fields were counted, and the mean was calculated. RESULTS: No significant relationship of mast cell distribution to inflammation in benign prostatic hyperplasias was observed. Significant differences between the mean mast cell numbers of intratumoral region and those of peritumoral region were noted (P<0.05). There was statistically significant difference in the mean mast cell numbers between well-differentiated groups and poorly-differentiated groups (P>0.05). CONCLUSION: There exists a relationship between prostate carcinoma tissue and mast cells. Mast cells may inhabit the tumor cells by different pathways.

Adenocarcinoma↗

PubMed2004

[Secondary compounds in rice varieties resistant to Nilaparvata lugens].

By the method of high-performance liquid chromatography (HPLC), this paper studied the contents of 13 secondary compounds from 130 samples of 26 rice varieties resistant to brown planthopper (BPH) Nilaparvata lugens biotype II. A prediction model was established through principal component analysis and multiple regression analysis: Y = 3.4593 - 0.02491 X1 + 0.08475 X2 - 0.04227 X8 + 0.1174 X12. The relationships between the BPH-resistant level of rice varieties and the area values of chromatographic peaks were significant (r2 = 0.84, P < 0.01). The results demonstrated that Peak 1, Peak 2, Peak 8 and Peak 12 were the major secondary compounds affecting the resistance to BPH biotype II, which suggested that the BPH resistance of the varieties came from the action of several secondary compounds that varied in contribution to the resistance.

Animals↗

PubMed2004

[Study on fluorescence spectra of the four heterocyclic compounds in solution].

The fluorescence spectra of the four compounds have been studied. Geometric configurations of the four compounds have been optimized by semi-empirical method RHF/AM1 of quantum chemistry. There is no imaginary frequency in vibrational analysis. Their fluorescence spectra have also been calculated by RHF/CIS. The results of calculation in solution are better agreement with experimental values than in gas phase.

English Abstract↗

PubMed2004

[A comparative study of malignant tissue diagnosis using ATR and microscopy FTIR spectroscopy].

A comparative FTIR study was undertaken between ATR (attenuated total reflection) and infrared microscopy on their application to measuring the same tissue for cancer diagnosis. The measurements showed that the coincidence of pathological diagnosis with ATR is higher than that of microscopy FTIR method. The result indicated that the measured area of tumor tissue is critical. The area for microscopy measurement is approximately 250 microm2, it reflects the heterogeneity of the tissue. However, the ATR measurement provides more information of malignant tissue for the measured area is 1.9 x 10(5) times than microscopy. Therefore, ATR exhibit the high accuracy in cancer detection for clinical application.

Fiber Optic Technology↗

PubMed2004

[Study on fluorescence spectra of four kinds of pyrazoline dimers].

The fluorescence spectra of four kinds of pyrazoline dimers have been studied. Their geometric configurations have been optimized by semi-empirical method RHF/AM1 of quantum chemistry. There is no imaginary frequency in vibrational analysis. Their fluorescence spectra have also been calculated by RHF/CIS. The results of the calculation are essentially consistent with the experimental values.

Dimerization↗

PubMed2004

[Oil spill identification by near-infrared spectroscopy].

Petroleum oil spill happens occasionally at sea. It's important to differentiate the exact products in order to carry out following actions to decrease harmfulness. In the present study, a rapid oil spill identification method by near infrared spectroscopy coupled with pattern recognition techniques is proposed. 56 simulated spilled oils of gasoline, diesel fuel and lubricating oil in marine were chosen to develop the method. Organic reagent of CCl4 was used to extract the oil. Pattern recognition techniques were established by principal component analysis (PCA) coupled with Mahalanobis' distance with the multiplicative signal correction (MSC) and Norris first derivative pretreatment. The study shows that PCA technique is a useful method to extract the main characteristics, and Mahalanobis' distance is an ellipsoidal boundary that circumscribes a data cluster. And oil spill samples with concentration above 0.4 microL x mL(-1) can be successfully identified by the method. The developed technique could be further applied to the identification of spilled oil in marine.

Algorithms↗

PubMed2004

[Study on the synthesis, characterization of structure and fluorescence properties of the solid complex of europium ion with 1,10-phenanthroline and 2-thiopheneglyoxylic acid].

The complex of europium with 1,10-phenanthroline and 2-thiopheneglyoxylic acid (HL) was synthesized. Its chemical formula was determined to be [EuL2 x phen x (H2O)3]NO3 by elemental analysis, electrical conductivity, IR and 1H NMR. It was found that the europium ion coordinated to the O atoms of 2-thiopheneglyoxylic acid and H2O, and to the N atoms of 1,10-phenanthroline. Its fluorescence property was determined by the excitation and emission spectra at room temperature, the emission peaks at 592 and 618 nm were assigned to the 5D0-7F1 and 5D0-7F2, respectively. It was also observed that the title complex emits strong red fluorescence under ultraviolet light at room temperature. In the IR spectrum, the characteristic absorption nu(C=O) (1719 cm(-1)), nu(C-O) (1232 cm(-1)), delta(O-H) (909 cm(-1)) of 2-thiopheneglyoxylic acid disappeared in the complex, the nu(as) and nu(s) of -COO- appeared at 1642 and 1408 cm(-1) in the complex respectively. In 1H NMR, the signals of 2-thiopheneglyoxylic acid were shifted upfield, and those of 1,10-phenanthroline downfield. It is proved by the TG curve that the complex is stable from ambient temperature to 250 degrees C.

Europium↗