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Biomedical subjects

Jie Feng

Publications and source records attributed to Jie Feng.

At least 55 records · Page 3Linked to original sources
PubMed2005

Effects of single herbal drugs on adhesion and migration of melanocytes.

OBJECTIVE: To find herbs with effects on adhesion and migration of melanocytes in vitro. MATERIALS AND METHODS: Ethanol extracts from 14 herbs were tested. Normal human melanocytes were obtained from neonatal foreskin, and the 48-well culture dish covered with fibronectin was used for the melanocyte adhesion assay. Motility was assessed by using the micropore filter method. RESULTS: The extracts of Danshen (Radix Salviae Miltiorrhizae), Tusizi (Semen Cuscutae) and Honghua (Flos Carthami) could enhance melanocyte adhesion to fibronectin, while Cijili (Fructus Tribuli) and Huangqi (Radix Astragali) promote melanocyte migration in vitro. Buguzhi (Fructus Psoraleae), Nü Zhen Zi (Fructus Ligustri Lucidi) and Baizhi (Radix Angelicae Dahuricae) could promote both adhesion and migration of melanocytes. CONCLUSION: The above herbs may play a role through promoting adhesion and/or migration of melanocytes in the treatment of vitiligo.

Cell Adhesion↗
PubMed2004

[Changes of discharge rate and pattern of 5-hydroxytrypamine neurons of dorsal raphe nucleus in a rat model of Parkinson's disease].

In the present study, changes of the neuronal activity of 5-hydroxytrypamine (5-HT) neurons of dorsal raphe nucleus(DRN) in a rat model of Parkinson's disease (PD) were investigated with glass microelectrode recording. The results showed that the discharge rates of 5-HT neurons in control and PD rats were (1.61+/-0.56) Hz and (2.61+/-1.97) Hz, respectively. The discharge rate of PD rats was significantly increased when compared to that of the control rats. In control rats, 79% of 5-HT neurons discharged regularly and 21% in bursts. In PD rats, however, 36% of 5-HT neurons discharged regularly, 16% irregularly and 47% in bursts. The percentage of 5-HT neurons discharging in bursts was obviously higher than that of the control rats (P<0.05). The data suggest that the discharge rate and bursting pattern of 5-HT neurons in DRN are increased in a rat model of Parkinson's disease.

Animals↗
PubMed2004

A novel process for inking the stamp with biomacromolecule solution used in reactive microcontact printing.

This paper describes a novel process for inking the stamp with biomacromolecule solution used in reactive microcontact printing. The stamp was first coated with biomacromolecule solution such as bovine serum albumin (BSA) solution for 20 min, and then dried by soft nitrogen flow. After cooling the stamp below the dew point for 1 min and incubated at room temperature for 10 s, a thin layer of condensed water was formed on the stamp surface. Then, an aldehyde functionalized glass slide was pressed immediately onto the stamp for certain time, yielding the covalently patterning of the biomacromolecules on the aldehyde-containing surface. A notable feature of this process is that the biomacromolecule solution can be inked onto the stamp at a controlled state, neither too "dry" nor too "wet". As a result, the covalently grafting reaction can occur at a comparable speed with those in solution, while avoiding the contamination caused by dispersal of excessive solvent.

Biopolymers↗
PubMed2004

Long-range ordered structures in diblock copolymer melts induced by combined external fields.

The structure of diblock copolymer melts under a single external electric or shear field, as well as under combined orthogonal external fields was investigated using a cell dynamic system. The phase structure was determined by coupling the effects of the external fields with the original structure of the bulk free of external fields. The single electric or shear field generated long-range cylinders in asymmetric A4mB6m diblock copolymers and distorted lamellae in symmetric A5mB5m diblock copolymers. Successive orthogonal shear followed by an electric external field generated long-range lamellae in symmetrical A5mB5m systems. However, the simultaneous orthogonal electric and shear fields could more easily form long-range lamellae than the sequential orthogonal fields. The dynamical processes in diblock copolymer melts under orthogonal fields have been also examined.

Journal Article↗
PubMed2004

Processing enzyme glucosidase II: proposed catalytic residues and developmental regulation during the ontogeny of the mouse mammary gland.

Following the action of glucosidase I to clip the terminal alpha1,2-linked glucose, glucosidase II sequentially cleaves the two inner alpha1,3-linked glucose residues from the Glcalpha1,2Glcalpha1,3Glcalpha1,3Man(9)GlcNAc(2) oligosaccharide of the incipient glycoprotein as it undergoes folding and maturation. Glucosidase II belongs to family 31 glycosidases. These enzymes act by the acid-base catalytic mechanism. The cDNA of the wild-type and several mutant forms of the fusion protein of the enzyme in which mutations were introduced in the conserved motif D(564)MNE(567) were expressed in Sf9 cells, and the proteins were purified on Ni-NTA matrix. The catalytic activity of the purified proteins was determined with radioactive Glc(2)Man(9)GlcNAc(2) substrate. The results show that the aspartate and glutamate within the D(564)MNE(567) motif can serve for catalysis, most likely as the acid-base pair within the active site of the enzyme. The developmental regulation of glucosidase II was studied during the ontogeny of the mouse mammary gland for its growth and differentiation. The mRNA of both alpha and beta subunits of the enzyme, immunoreactive alpha and beta subunits, and enzyme activity were measured over the complete developmental cycle. The changes in all the parameters were consistent with similar fluctuations with several other enzymes of the N-glycosylation machinery reported earlier, reaching a three- to fourfold increase over the basal level in the virgin gland at the peak of lactation. Altogether it appears that there is a coordinated regulation of the enzymes involved in protein N-glycosylation during the development of the mouse mammary gland.

Amino Acid Sequence↗
PubMed2004

Receptor-mediated stimulatory effect of oligochitosan in macrophages.

Oligochitosan, which has greater than 3 but less than 10 saccharide (N-acetylglucosamine or glucosamine) residues, is obtained by either chemical or enzymatic hydrolysis of chitosan. In this work, we demonstrated that oligochitosan had an in vitro stimulatory effect on the release of tumor necrosis factor-alpha and interleukin-1 beta in macrophages. Moreover, we observed that oligochitosan could be uptaken by macrophages through confocal laser microscopy. Scatchard analysis of internalization of 2-aminoacridone-oligochitosan in macrophages indicated its internalization was mediated by a specific receptor on macrophage membrane with a Kd of 2.1 x 10(-5) M. Competition studies showed that mannose could inhibit oligochitosan internalization, while lipopolysaccharide and beta-glucan could not do it. Inhibition of mannose-BSA, fucose-BSA, and N-acetylglucosamine-BSA on oligochitosan internalization further suggests that oligochitosan internalization is mediated by a macrophage lectin receptor like with mannose specificity.

Acetylglucosamine↗
PubMed2004

Attractive interactions in dispersions of identical charged colloidal particles: a Monte Carlo simulation.

Using the Debye-Hückel pair potential, the collective interactions between identical charged particles were examined via Monte Carlo simulations. The results have shown that when the number of charges per particle and the particle volume fraction were sufficiently large, the pair long-range electrostatic repulsion generated an effective attractive interaction between identical charged particles because of many-body effects. Disordered liquid-like structures, ordered crystal-like structures, ordered structures dispersed in disordered ones, and disordered structures dispersed in ordered ones have been found. The structures are dependent on the volume fraction and charge of the particles, as well as on the electrolyte concentration.

Journal Article↗
PubMed2004

Effects of non-starch polysaccharides enzymes on pancreatic and small intestinal digestive enzyme activities in piglet fed diets containing high amounts of barley.

AIM: To investigate effects of non-starch polysaccharides(NSP) enzymes on pancreatic and small intestinal digestive enzyme activities in piglet fed diets containing high amounts of barley. METHODS: Sixty crossbred piglets averaging 13.5 kg were randomly assigned to two treatment groups with three replications (pens) based on sex and mass. Each group was fed on the diet based on barley with or without added NSP enzymes (0.15%) for a 40-d period. At the end of the experiment the pigs were weighed. Three piglets of each group were chosen and slaughtered. Pancreas, digesta from the distal end of the duodenum and jejunal mucosa were collected for determination. Activities of the digestive enzymes trypsin, chymotrypsin, amylase and lipase were determined in the small intestinal sections as well as in homogenates of pancreatic tissue. Maltase, sucrase, lactase and gamma-glutamyl transpeptidase (gamma-GT) activities were analyzed in jejunal mucosa. RESULTS: Supplementation with NSP enzymes improved growth performance of piglets. It showed that NSP enzymes had no effect on digestive enzyme activities in pancreas, but decreased the activities of proteolytic enzyme, trypsin, amylase and lipase in duodenal contents by 57.56%, 76.08%, 69.03% and 40.22%(P<0.05) compared with control, and increased gamma-GT activities in jejunal mucosa by 118.75%(P<0.05). CONCLUSION: Supplementation with NSP enzymes in barley based diets could improve piglets' growth performance, decrease activities of proteolytic enzyme, trypsin, amylase and lipase in duodenal contents and increase gamma-GT activities in jejunal mucosa.

Animals↗
PubMed2004

Synthesis of a novel photoaffinity derivative of 1-deoxynojirimycin for active site-directed labeling of glucosidase I.

Glucosidase I releases the distal alpha1,2-glucosyl residue in the Glc(3)Man(9)GlcNAc(2) precursor immediately after its transfer from the dolichol-P-P-linked intermediate in the endoplasmic reticulum and triggers the processes for the posttranslational remodeling, folding, and maturation of N-linked glycoproteins. The enzyme has been purified and characterized from several eukaryotic systems. Its cDNA and the gene have also been cloned. The enzyme is a target for the development of drugs for several pathological conditions. A structural analysis on the biochemically purified enzyme has been hampered because of its low abundance and unstable character. The recombinant enzyme has not been obtained in quantity and characterized. Glucosidase I is strongly inhibited by the glucose analog 1-deoxynojirimycin (DNM). To gain an insight into the architecture of the active site of the enzyme, we here report the synthesis of a photoactive derivative of DNM, viz. 4-(rho-azidosalicylamido)butyl-5-amido-pentyl-1-DNM (ASBA-P-DNM). With an IC(50) of 0.42 micro M, it is nearly nine times stronger inhibitor than DNM (IC(50) = 3.5 micro M). On photolysis, the bound [(125)I]ASBA-P-DNM specifically labels the native enzyme, which yields a 24-kDa peptide after treatment with V8 protease, apparently representing the region around its active site. Thus ASBA-P-DNM should serve as a novel reagent to conduct structure-function analysis on glucosidase I.

1-Deoxynojirimycin↗
PubMed2004

A HU-like gene mutation in Rhizobium leguminosarum bv. viciae affects the expression of nodulation genes.

NodD is the major regulator of nod genes expression in rhizobia. Previously, a HU-like protein in Rhizobium leguminosarum bv. viciae has been identified to bind specifically with nod promoters and be involved in in vitro nodD transcription, but its in vivo function remained unknown. In this work we have cloned and sequenced the R. leguminosarum bv. viciae gene, named hurL, for this HU-like protein. Using the E. coli-expressed HurL proteins, we proved that HurL had high affinity to several nod promoters and showed a stimulation effect on in vitro nodD transcription at appropriate concentration. The R. leguminosarum bv. viciae hurL gene was mutated by insertion of a kanamycin resistance cassette. The obtained hurL mutant strain M704 exhibited poor growth under free-living conditions and failed to induce nodules on Pisum sativum cv. Frisson and Vicia hirsuta. Further studies of NodD production and nod genes-lacZ fusions expression in the hurL mutant revealed that inactivation of hurL led to severe impairment in the nodD expression, repression in the inducible expression of nodA and nodF, and slight enhancement in the expression of px2, a gene identified earlier in this lab. These results suggested that hurL might be required for maintaining the normal expression of nod genes in R. leguminosarum bv. viciae.

Bacterial Proteins↗
PubMed2004

Halorubrum xinjiangense sp. nov., a novel halophile isolated from saline lakes in China.

A novel halophilic archaeon, strain BD-1T, was isolated from Xiao-Er-Kule Lake in Xinjiang, China. The taxonomy of strain BD-1T was studied by polyphasic methods. According to 16S rRNA gene sequence similarity, strain BD-1T was phylogenetically related to Halorubrum trapanicum (98.4 %), Halorubrum sodomense (98.0 %), Halorubrum distributum (97.8 %) and Halorubrum coriense (97.3 %). Strain BD-1T is able to grow at 10 degrees C and further differs physiologically from the above species in the assimilation of sugars. The G + C content of DNA is 68.0 % (Tm). The DNA-DNA relatedness values to Hrr. trapanicum and Hrr. distributum are 47 and 24 %, respectively. It is concluded that strain BD-1T represents a novel species of the genus Halorubrum, for which the name Halorubrum xinjiangense sp. nov. is proposed. The type strain is BD-1T (= AS 1.3527T = JCM 12388T).

Base Composition↗
PubMed2004

[Establishment and comparison of two intraperitoneally transplanted human ovarian carcinoma models with immune reconstitution in severe combined immunodeficient mice].

BACKGROUND & OBJECTIVE: Ovarian carcinoma is leading cause of death in gynecologic malignancies. The survival rate cannot be improved after routine surgery, chemotherapy, and radiotherapy. Therefore biotherapy becomes the fourth treatment pattern for ovarian carcinoma. Adequate experimental models for the development of biologic therapeutic strategies are needed. Our purpose was to establish and compare two intraperitoneally transplanted human ovarian carcinoma models with human immune reconstitution in severe combined immunodeficient (SCID) mice. METHODS: Six and ten C.B17/SCID mice were intraperitoneally injected with human ovarian adenocarcinoma SKOV3 and SKOV3.ip1 cells, respectively. Their biological, histological, and immunological features were compared. Ascites of the mice in SKOV3.ip1 group was injected into other six mice. All the 22 SCID mice were intraperitoneally injected with human peripheral blood lymphocytes (PBL) to establish immune reconstituted model. RESULTS: The taken rates of the SKOV3 and SKOV3.ip1 groups were both 100%. The latent periods of tumor growth were 20-41 days and 22-30 days, respectively (P >0.05). While the mean survival time were 50-78 days and 32-43 days, respectively (P< 0.0001). 83.3% (5/6) of the mice injected with ascites of the mice in SKOV3.ip1 group successfully formed new tumor mass and ascites. Autopsy showed the tumors of the two models were widespread in pelvic cavity. The SKOV3.ip1 group also had 0.35-5.60 ml bloody ascites that was similar to the clinical behavior of most patients, while only 0.2 ml in one mice of SKOV3 group. Histological results showed the tumors of the two groups remained the characteristics of serous papillary adenocarcinoma of human ovary, and immunohistochemistry staining showed the ovarian associated antigen OC166-9 were both positive. Human IgG were detected in 72.7% (16/22) of the mice, and human CD4(+) and CD8(+) T cells were positive in 54.5% (12/22) of the mice. CONCLUSION: The two intraperitoneally transplanted human ovarian carcinoma models had been established in human PBL reconstituted SCID mice. The SKOV3.ip1 model may be an ideal animal model for biotherapy research of ovarian carcinoma as it simulates the intraperitoneally disseminating behavior of human ovarian carcinoma in the patients with immune function, and it took relatively shorter time to be established.

Animals↗
PubMed2004

[In vivo study of antitumor immune responses induced by anti-idiotypic minibody vaccine of ovarian cancer].

BACKGROUND & OBJECTIVE: 6B11 anti-idiotypic minibody can be constructed by fusion of anti-idiotypic single chain antibody (6B11scFv) to human IgG(1) hinge and CH3, which can simulate the function of ovarian carcinoma antigen. It has immune activity of both 6B11 and human immunoglobulin IgG(1) Fc. This study was designed to evaluate whether anti-tumor immune response can be induced in BALB/c mice immunized with 6B11anti-idiotypic minibody and explore its probability as ovarian cancer vaccine. METHODS: BALB/c mice were immunized repeatedly by 6B11 anti-idiotypic minibody. Competition inhibition test, indirect ELISA test, and immune flow cytometry were used for analyzing the serum characterization of anti-anti-idiotypic antibody (Ab3) and the changes of T lymphocyte phenotype of spleen. RESULTS: The specific antitumor immune response could be induced in BALB/c mice after immunized with anti-idiotypic minibody without carrier proteins and adjuvant. The Ab3 maintained at a high level till 30 day after the last immunization. It stimulated proliferation of CD4+ T cells and CD8+ T cells from the spleen of BALB/c mice on 4th day, 14th day, 24th day, and 30th day after the last immunity respectively. CONCLUSIONS: 6B11 anti-idiotypic minibody can induce both humoral and cellular immunity against ovarian carcinoma in vivo, which provided experimental evidence for clinical use of fusion protein 6B11 minibody as anti-idiotype vaccines against ovarian carcinoma.

Animals↗
PubMed2004

[Human pituitary tumor transforming gene 1 expression in ovarian carcinoma and its clinical significance].

BACKGROUND & OBJECTIVE: Human pituitary tumor transforming gene 1 (hPTTG1) is a newly identified oncogene. We performed a large-scale screening survey to identify related genes expressed in advanced and poorly differentiated serous ovarian carcinoma using cDNA microarray analysis, and found that hPTTG1 is one of highly up-regulated genes in ovarian carcinoma. This study was to examine hPTTG1 mRNA and protein expression in various epithelial ovarian carcinoma,analyze the relationship of its expression level with FIGO stage and histological grade, and explore the functional role of hPTTG1 in ovarian carcinoma pathogenesis. METHODS: HPTTG1 mRNA expression in 27 cases of epithelial human ovarian carcinoma, and 4 cases of normal ovary was assessed with non-competitive reverse transcription polymerase chain reaction (RT-PCR), and hPTTG1 protein expression in these 27 cases of human ovarian carcinoma, and 18 cases of normal ovary was examined by immunohistochemistry. RESULTS: HPTTG1 mRNA expression level in normal ovary was low, while in ovarian carcinoma was significantly higher than that in normal counterparts (P < 0.01). Fold increase of ovarian cancer tissues to normal ovary tissues is 1.1-4.8 (median 2.4).HPTTG1 mRNA high expression level was related to poor tumor differentiation (r = 0.686, P < 0.05), but the correlation with FIGO stage was not detected. HPTTG1 protein was expressed in all cases of ovarian carcinoma, but not in normal ovaries. CONCLUSIONS: Increased hPTTG1 expression may be an important factor involved in early tumorogenesis, and may be associated with poor tumor differentiation. HPTTG1 could be a potential molecular marker of epithelial ovarian carcinoma.

Carcinoma, Endometrioid↗
PubMed2004

[Induction of T cell responses against autologous ovarian cancer by anti-idiotype minibody-pulsed dendritic cells].

BACKGROUND & OBJECTIVE: Immunotherapy of sensitizing dendritic cells (DCs) with antigen,protein,and frozen cancer cell has been widely used in treating various cancers. The 6B11 anti-idiotype-antibody,a fusion protein prepared by our research center,can mimic ovarian cancer-associated antigen OC166-9. This study was to induce T cell cytotoxicity against autologous tumor cells of patients with ovarian cancer by 6B11 anti-idiotype-antibody. METHODS: Peripheral blood samples were collected from 10 patients with epithelial ovarian cancer,Monocytes were isolated and cultured to obtain DCs. Immature DCs were stimulated with 6B11 anti-idiotype-antibody (MINI-DC group); unpulsed DCs (unpulsed-DC group),mouse F(ab) '2 fragments pulsed DCs [F(ab)'2-DC group],and T cells alone (T group) were served as controls. Mature DCs were harvested. (3)H-thymidine ((3)H-TdR) incorporation approach was used to measure effect of DCs on stimulating auto-T cell proliferation. Cytotoxicity of DC-activated T cells against auto-tumor cells was measured with (51)Cr 6-h release test,tumor cell lines,SKOV3,HLE,and K562, were used as controls. RESULTS: In 4 cases,cpm value of (3)H-TdR incorporation,as symbol of auto-T cell proliferation, in MINI-DC group was significantly higher than those in control groups. In 5 cases,specific cytotoxicity effect of T cells on auto-tumor cells was observed in MINI-DC group at effect-target ratio of 20:1,the toxicity effect of T cells in MINI-DC group was 25%-100%,significantly higher than those in F(ab)'2-DC group (18%-40%), unpulsed-DC group (13%-43%),and T group (9%-58%). In 4 cases,the toxicity effect of T cells in MINI-DC group, at effect-target ratio of 20:1,on auto-tumor cells was 25%-100%, higher than those on SKOV3 cells (5%-51%),HLE cells (2%-38%),and K562 cells (2%-25%). Moreover,the toxicity effect of T cells in MINI-DC group on auto-tumor cells can be partially blocked by anti-MHC-I antibody,which indicated that the toxicity was antigen-specific. CONCLUSION: DCs loaded with 6B11 anti-idiotype antibody that mimic ovarian cancer antigen can induce antigen specific T cell cytotoxicity against auto-ovarian tumor cells in vitro.

Adult↗
PubMed2004

[Effects of MSF on melanocyte adhesion and migration in vitro].

OBJECTIVE: To investigate the Malytea Scurfpea fruit (MSF) on melanocyte adhesion and migration. METHOD: Human epidermal melanocytes were treated with MSF and Ginger respectively, then adhesion to bovine serum fibronectin-coated culture dishes was checked. Control and treated cells were also examined for migration into micropore filters coated with the same protein. RESULT: Compared with control, MSF treated melanocytes were obviously easier to adhere to the dishes and move into the filters in a dose-dependent manner. When the dose of MSF was 200 mg x L(-1), it could not reincrease melanocyte adhesion and migration. At 10 mg x L(-1), under every other concentrations of MSF, there was no marked difference among MSF-treated, Ginger-treated and untreated melanocytes (P < 0.05) when adhesion test were studied. But to migration, even at 10 mg x L(-1) MSF, there was obvious increased migration compared with MSF-untreated or Ginger-treated melanocytes (P < 0.01). CONCLUSION: MSF has effect on melanocyte adhesion and migration, which can explain, in part, the capacity of MSF to modulate melanocyte function in vitiligo lesions.

Cell Adhesion↗
PubMed2004

Effects of endothelin-1 on melanocyte adhesion and migration.

OBJECTIVE: To investigate the effect of endothelin-1 (ET-1) on the adhesion and migration of melanocyte in vitro. METHODS: Human epidermal melanocytes that had been cultured and purified were treated with ET-1 and observed for adhesion to bovine serum fibronectin-coated culture dishes. Stem cell factor (SCF) and ET-1 treated cells were also examined for migration into micropore filters coated with the same protein. RESULTS: Compared with the SCF group, ET-1 treated melanocytes were easier to adhere to the dishes and to be moved into the filters, especially when the concentration was 32 nmol/L. When the concentration of ET-1 was 128 nmol/L or more, it could inhibit the adhesion and migration of melanocyte. At any concentration of ET-1 except at 2 nmol/L, there was a significant difference between ET-1-treated and untreated melanocytes (P < 0.01) when the adhesion test was carried out. However, even at 2 nmol/ L ET-1, there was obviously increased migration compared with those of ET-1 untreated melanocytes and SCF-treated cells (P < 0.01). CONCLUSION: ET-1 may influence the adhesion and migration of melanocyte, which can partly explain the capacity of ET-1 to regulate the melanocyte function in vitiligo lesions.

Cell Adhesion↗