Biomedical subjects

Chun-yan Wang

Publications and source records attributed to Chun-yan Wang.

15 recordsLinked to original sources

PubMed2006

[Fluorescence analysis of crude oil samples with different spectral approaches].

Fluorescence techniques based on emission spectrum, synchronous fluorescence spectrum (SFS), or three-dimensional (3D) fluorescence spectrum, have been widely used in medical, biological and chemical analyses. In the present paper, 25 crude oil samples from 15 different borefields in the concentration range from 10(-4) g x L(-1) to 10 g x L(-1) have been investigated with different spectral approaches. It was shown that, compared with conventional emission spectrum based technique used in oil logging, the 3D fluorescence technique can provide much more information in the analysis of crude oil samples but at the price of time consuming. While the SFS spectrum of a crude oil sample, taken under the emission and excitation wavelength synchronous scan with deltalambda=40 nm, can represent the main characteristic of the 3D spectrum provided, with even better spectral qualities. All the results suggest that SFS technique is a more suitable approach in crude oil sample analysis than the other two, and has a great potential to be developed as a new quantitative analysis method in petroleum logging.

English Abstract↗

PubMed2006

[2+1, 1+1 and 1+1+1 multiphoton resonant ionization of manganese atom].

Resonance ionization spectroscopy (RIS) is an important technique for trace analyses. In the present paper, based on the population rate equations, "2+1", "1+1" and "1+1+1" multiphoton resonant ionization processes of Mn atom are studied by computer simulation. The phenomena and the threshold condition of saturated excitation and ionization processes are discussed. The threshold laser intensities for saturated ionization of Mn atom with different RIS schemes are calculated. With the typical Q-switched laser duration of 10 ns, the obtained saturation threshold laser intensity for the ionization steps in all the resonant ionization processes of Mn is about 10(8) W x cm(-2) with the exception of the "1+ 1" resonant ionization of Mn which is 3 orders of magnitude lower. The obtained threshold laser intensity for the saturated excitation steps is about 10(2)-10(3) W x cm(-2) in "1+1" and "1+1+1" ionization processes. It is also shown that the threshold laser intensity required for saturated excitation and ionization processes turns smaller with the laser duration prolonged.

English Abstract↗

PubMed2006

[A new method for concentration determination of crude oil sample using three-dimensional synchronous fluorescence spectra].

In the spectral investigation of crude oil samples, it has been found that the synchronous fluorescence spectra (SFS) of the crude oil sample varied with the concentration in both the intensity and the location of peaks. Considering the information about both the changes in SFS, a new method for the concentration determination of crude oil sample using three-dimensional synchronous fluorescence was developed and introduced in the present paper. A number of samples have been investigated to verify the feasibility of the method. The concentration of each sample has been determined with a deviation under 3% in the concentration range from 10(-4) to 1.0 g x L(-1). All the results suggest that the newly developed method may become an useful means in petroleum logging.

English Abstract↗

PubMed2006

[Influence of scald on the cytoskeleton of colonic smooth muscle cells of the rats].

OBJECTIVE: To investigate the changes in the morphology and cytoskeleton (CSL) content of the CSL in the colonic smooth muscle cells (SMCs) of rats in early postscald stage, so as to elucidate the mechanism of dysfunction of gastrointestinal motility. METHODS: Seventy Wistar rats were randomly divided into normal control (n = 10, without scald) , and scald ( n = 60, with 10 cm x 7 cm wound inflicted on the back) groups. The colonic smooth muscle tissue of 10 normal rats and scalded rats were harvested at 1, 3, 6, 12, 24 and 48 postscald hours( PSH) and divided into two parts: one for histologic examination, and the other for the detection of CSL changes in the colonic smooth muscle tissue by flowcytometry method. RESULTS: The electron microscope examination showed that the arrangement of cytoskeleton of SMC of the scalded rats during 1 to 3 PSH was disordered, and sparse, and the condensed area was uneven, with fragmentation. But the morphology and distribution of CSL gradually restored to normal state during 6 to 12 PSH, and it approached that of normal group at 48 PSH. The CSL content in the colonic smooth muscle tissue of scalded rats was obviously increased at 1 PSH (610+/-23) , decreased thereafter, evidently lower than that in control group at 3 PSH (92+/-17) , and then it started to increase at 12 PSH, exceeding the normal value at 24 PSH, and continued to rise until 48 PSH. There was significant difference in CSL content in the colonic smooth muscle tissue of the rats between scald and control group ( P < 0.05 or 0. 01). CONCLUSION: Changes in the morphology and CSL content in the colonic smooth muscle tissue can be observed at early stage after a scald, which imply the kinetic balance between damage and repair in the body. In addition, changes in CSL content in the colonic smooth muscle tissue may be important factors in producing colonic dysfunction, damage of intestinal wall structure, and dynamic abnormalities of the colonic smooth muscle.

Actins↗

PubMed2005

[Preparation and characterization of monoclonal antibodies against human RANTES molecule].

AIM: To prepare monoclonal antibodies against human RANTES molecule and identify the expression of RANTES in rat small intestine after small bowel transplantation. METHODS: Murine mAbs were prepared by B lymphocyte hybridoma technique. The expression of RANTES in rat small intestine after small bowel transplantation was detected by immunohistochemistry. RESULTS: Four hybridoma cell lines secreting monoclonal antibodies to human RANTES, FMU-RANTES 1, FMU-RANTES 2, FMU-RANTES 3 and FMU-RANTES 4, were established. The titers of a scetic mAbs reached to 1 x 10(-6) and the Ig subclass of FMU-RANTES 1, FMU-RANTES 3 and FMU-RANTES 4 was IgG1(kappa) and that of FMU-RANTES 2 was IgG2b(kappa). Among these mAbs, FMU-RANTES 1, FMU-RANTES 2 and FMU-RANTES 3 could bind human RANTES protein in Western bolt. FMU-RANTES 1, FMU-RANTES 2 and FMU-RANTES 4 could be used in immunohistochemistry staining. Rat RANTES molecule could be detected in the cyto plasm of epithelial cells in rat small intestine after small bowel transplantation. CONCLUSION: Four mAbs against RANTES molecule were prepared, which can provide a useful tool in research on the structure and function of RANTES molecule. High expression of RANTES may be involved in the rejection of allogeneic graft.

Animals↗

PubMed2005

[Detection of small molecules based on surface plasmon (correction of plasman) resonance technology].

OBJECTIVE: To develop a detective method applied in online assaying of astronauts' humours using the portable online bio-molecules analyzer (POBA) based on surface plasmon resonance biosensor. METHOD: An assay format was developed based on the detection of 2, 4-Dinitrophenyl-hydrazine. The bio-molecule slide was made by DNP-BSA. Range of detection and standard curve were obtained using inhibition assay. Reliability and specificity of the assay were also tested. RESULT: 1) The linear range of the assay was 7.8 ng/ml-2 micrograms/ml with lower detection limit of 2.5 ng/ml; 2) Preparation of the bio-molecule slide and regeneration of the biosensor ensured detections for many samples. CONCLUSION: This assay method can be used to detect small molecules sensitively, rapidly and easily. It can be repeated with good reliability, and has a good application in space medicine.

Aerospace Medicine↗

PubMed2005

[Identification of cell lines expressing the putative ligand(s) for LAIR-1(CD305) and LAIR-2(CD306)].

AIM: To identify cell lines expressing the putative ligand(s) for LAIR-1 and LAIR-2. METHODS: CHO cell lines secreting LAIR-1-Fc or LAIR-2-Fc fusion protein were prepared and the supernatants from the CHO cell lines were collected and purified by protein A affinity chromatography column. Several cell lines were stained with the purified LAIR-1-Fc and LAIR-2-Fc fusion proteins and then analyzed by flow cytometry for detecting the expression of their putative ligand(s). To exclude non-specific binding between the cells and the fusion proteins, the cell lines expressing their putative ligand(s) were pre-incubated with the mAbs against LAIR-1 or LAIR-2, stained with the fusion proteins, and analyzed by flow cytometry. RESULTS: Both LAIR-1 and LAIR-2 fusion proteins bound strongly with human amnion-derived epithelial cell line WISH, and moderately with human melanoma cell line C32, human embryo kidney epithelial cell line 293T, and human umbilical vein endothelial cell line ECV304. Furthermore, this binding could be blocked by the mAb FMU-LAIR-2.2 (recognizing both LAIR-1 and LAIR-2) or mAb FMU-LAIR-2.1(recognizing LAIR-2). CONCLUSION: The putative ligand(s) for LAIR-1 and LAIR-2 were expressed on WISH, C32, 293T and ECV304 cell lines. LAIR-1 and LAIR-2 may share the same ligand(s). These findings lay the foundation for the molecular cloning of the putative ligand(s) for LAIR-1 and LAIR-2.

Animals↗

PubMed2005

[Specialization in thyroid surgery].

OBJECTIVE: To evaluate the results of surgically treated patients with benign thyroid disorders from Department of Otolaryngology- Head and Neck Surgery. METHODS: The clinical data of 496 patients operated for benign thyroid disorders were retrospectively analyzed in this department from January 2001 to April 2004. The incidence of complications, particularly postoperative permanent recurrent laryngeal nerve palsy and hypocalcemia, duration of surgery, incision length on the neck, hospitalization days and postoperative recurrence were evaluated. RESULTS: Unilateral total thyroidectomy with contralateral partial lobectomy was performed in 314 cases, unilateral total thyroidectomy with isthmectomy in 76, bilateral subtotal thyroidectomy with the remnant left at the upper pole in 29, isthmectomy in 3, total thyroidectomy in 46. The operations on 28 patients with substernal goiter have been successfully performed via cervical collar incision. Of these patients, the incidences of unilateral recurrent laryngeal nerve paralysis and temporary postoperative hypocalcemia were 0.2% (1/496) and 1.8% (9/496), respectively. There were no bilateral vocal cord paralyses and permanent hypocalcaemia. Postoperative hemorrhage requiring reoperation occurred in 3 cases (0.6%). No patients had incision infection. The mean duration of surgery was 66 min. The mean incision length on the neck was 5.2 cm. The incidence of postoperative recurrence was 0.2% (1/496). The mean hospitalization day was 6.3 d. CONCLUSIONS: Otolaryngologists who had received stringent training of head and neck surgery seem to have the advantage to avoid injury of recurrent nerve in the thyroid surgery.

Adult↗

PubMed2004

[Preliminary analysis on the gene expression profiles of medulloblastomas by use of cDNA array].

OBJECTIVE: To explore the molecular genesis of medulloblastomas with cDNA array. METHODS: Four samples of medulloblastomas and 1 sample of normal brain tissue were collected freshly. After total RNA extraction, the (32)P targeted cDNA probes were converted and then hybridized with Atlas Human Cancer Array 1.2. The gene expression profiles were acquired through autoradiography. The discrepancy between the tumor and the normal brain tissue was analyzed with Atlas Image 1.01a. RESULTS: In comparison with the genes in the normal brain tissue, 6 down-regulated and 35 up-regulated genes in the medulloblastomas were revealed by means of the microarrays and autoradiography, and were verified by reverse transcriptase-PCR. The regulatory trends of most differential expression genes were in compliance with the biological features of this tumor. CONCLUSION: Medulloblastomas are diseases involving multiple genes with some molecular pathological mechanisms different from the astrocytic gliomas. There are complex interrelationships between these genes, which need to be further researched.

Child↗

PubMed2004

[Experimental study on NK cells promoting donor marrow engraftment and hematopoietic reconstitution after MHC haploidentical BMT in mice].

OBJECTIVE: To explore the effect of donor-derived NK cells added to pretreatment conditioning regimen on hematopoietic reconstitution after MHC haplotype-mismatched BMT in mice. METHODS: Murine model of MHC haplotype-mismatched BMT was established by using BALB/c(H-2d) x C57BL/6(H-2b) (CB6F(1)(H-2d/b)) mouse as recipient, and C57BL/6(H-2b) mouse as donor. Fifty recipient mice were divided into 5 groups. The mice in the first three groups were each infused 1 x 10(6), 5 x 10(5), 2 x 10(5)/mouse donor-derived NK cells, respectively before TBI ((60)Co, 9.0 Gy) and then conditioned with TBI, followed by infusion of C57BL/6(H-2b) mice bone marrow cells four hours later. The mice in the fourth group received TBI only, and in the fifth group, TBI and BMT at the some doses as the first three groups. Hematopoietic reconstitution, survival time, body weight, histopathology of the recipients were followed up. RESULTS: (1) Survival time was (5.15 +/- 0.66) days for the fourth group, and > 30 days for the other 4 groups. (2) Leukocyte and platelet counts at day 10 after BMT were (0.99 +/- 0.22) x 10(9)/L and (61.0 +/- 7.27) x 10(9)/L respectively for the fifth group and (2.01 +/- 0.21) x 10(9)/L, (101.50 +/- 16.34) x 10(9)/L; (1.98 +/- 0.29) x 10(9)/L, (99.50 +/- 16.41) x 10(9)/L and (1.97 +/- 0.21) x 10(9)/L, (98.0 +/- 16.19) x 10(9)/L for the first three groups, respectively. Histopathology displayed no GVHD in all the groups. CONCLUSION: Donor-derived NK cells could promote hematopoietic reconstitution after MHC haplotype-mismatched BMT in mice.

Animals↗

PubMed2004

[Construction and expression of human EpCAM eukaryotic expression vectors and identification of their products].

AIM: To construct EpCAM eukaryotic expression vectors pIg-EpCAM and pEGFP-EpCAM and to express them in COS7 cells. METHODS: EpCAM cDNA was amplified by PCR and then inserted into the pIg and pEGFP vectors respectively to construct recombinant vectors pIg-EpCAM and pEGFP-EpCAM. The two recombinant vectors were transfected into COS7 cells under the mediation of liposome. The expressed EpCAM-Ig fusion protein was detected by Western blot. The expression of EpCAM-GFP fusion protein was observed under fluorescence microscope. RESULTS: DNA sequencing demonstrated that EpCAM was correctly cloned into the two vectors. The culture supernatant of the pIg-EpCAM-transfected COS7 cells could bind effectively to mAb against human IgG Fc. Green fluorescence distributed evenly in the cytoplasm and nuclei of pEGFP-transfected COS7 cells, whereas in pEGFP-EpCAM transfected COS7 cells, green fluorescence distributed mainly on the surface of the cells. CONCLUSION: Two EpCAM eukaryotic expression vectors have been constructed and expressed successfully, which lays the foundation for functional research of EpCAM and for preparation of mAb to EpCAM.

Animals↗

PubMed2003

[Preliminary study on the mechanism of connexin 43 gene transfection in the control of glioma cell proliferation].

OBJECTIVE: To study the mechanism involved in the control of glioma cell proliferation with transfection of connexin (Cx) 43 gene. METHODS: C6 rat glioma and TJ905 human glioblastoma cell lines without Cx43 gene expression were transfected with Cx43cDNA mediated by lipofectamine. Northern blot, in situ hybridization and immunohistochemical technology were used to detect the expression of Cx43mRNA and its protein with MTT assay and silver colloid stain for the detection of cell proliferation, TUNEL method for determination of cell apoptosis, scrape loading dye transfer (SLDT) for GJIC, Western blot and immunohistochemical technology for bFGF, PDGF, EGFR, IGF-I and IGFBP3 expression. RESULTS: Cx 43 gene transfected glioma cells showed decreased proliferation, restored GJIC and decreased bFGF, PDGF, IGFBP3, except EGFR expression and cell apoptosis which showed no change. CONCLUSION: The mechanism of Cx 43 gene inhibiting gliomas cell proliferation is the restoration of GJIC and decreased autocrine growth factors.

Animals↗

PubMed2003

[Inhibitory effect of NS398 on the proliferation of human ovarian cancer cell lines CAOV3 and OVCAR3 in vitro].

OBJECTIVE: To observe the inhibitive effect of cyclooxygenase-2 (COX-2) selective inhibitor, [N-[2-(cyclohexyloxy)-4-nitrophenyl]-methane sulfonamide] (NS398, one of nonsteroidal anti-inflammatory drugs), on human ovarian cancer cell lines CAOV3 and OVCAR3 during the proliferative process in vitro. METHODS: Streptovidin peroxidase conjugated (SP) immunohistochemical assay was performed to examine the expression of COX-2 protein in human ovarian epithelial serous cancer cell lines CAOV3 and OVCAR3 respectively. The proliferative inhibition process of the two cell lines by NS398 was observed with methyl thiazolyl tetrazolium (MTT) rapid photocolorimetric assay. Cell morphologic changes were observed under the inverted phase contrast microscope and electron microscope. DNA ladder assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were employed for the cell apoptosis. RESULTS: COX-2 protein was expressed in both of the cell lines. The inhibitory rate of proliferation exerted by NS398 increased with the density and the time of NS398 respectively. In contrast to the control, the absorbance of the experiment (NS398 200 micro mol/L for 72 h) decreased obviously (P < 0.05). With regard to the cell morphology, the "vacuole" presented in the cytoplasm and apoptosis body was able to be observed, and the microvilli on the surface of the cell disappeared. There were characteristic ladder bands after CAOV3 and OVCAR3 were treated by NS398 (100 micro mol/L) for 72 h. The brown-yellow granules located in the nucleus of most CAOV3 cells, which indicated apoptosis. CONCLUSIONS: Above findings suggest that COX-2 may provide an effective chemotherapeutic target for ovarian cancer, and selective COX-2 inhibitors can be used as chemotherapeutic agents for ovarian cancer.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2003

[Preliminary study on the gene expression profiles of ependymomas with cDNA array].

OBJECTIVE: To investigate the differential gene expression of ependymomas. METHODS: Four fresh samples of ependymomas and 1 of normal brain tissue were collected during operation. The extracted total RNAs were converted as (32)P tagged cDNA probes, which were then hybridized with the Atlas Human Cancer Array, producing the array based hybridization maps following the protocol provided with the kit. A set of special software was applied to the analysis and RT-PCR was performed to test the result. RESULT: In comparison with the normal brain tissue, there were 31 upregulated gene and 1 downregulated gene in ependymomas, most of which were firstly found to be differentially expressed in this kind of tumor. CONCLUSION: The discrepancy of gene expression profiles between ependymomas and normal brain tissues is highly put through and effectively detected with cDNA array, which provides new information for the further research on the molecular mechanisms of this lesion.

Brain↗

PubMed2002

[Determination of trace manganese in food by flame atomic absorption spectrometry with microemulsion sampling injection].

The effects of four surfactants and microemulsion were studied in the detection on trace manganses in food by flame atomic absorption spectrometry. The results showed that the absorption increased when one of two of surfactants and microemulsion were used. The microemulsion are the most effective. The absorption increased by 58%. A method of determination on trace manganese by means of atomic absorption spectrometry sensitized with microemulsion was established. At the same time, we also made a recovery experiment for trace manganese in food, The relative standard deviation is 2.90%-5.62%, and recovery is 97.0%-98.2%.

Emulsions↗