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Biomedical subjects

Q Wang

Publications and source records attributed to Q Wang.

At least 415 records · Page 23Linked to original sources
PubMed2000

[Determination of notoginsenoside R1 in radix notoginseng by HPLC-ELSD].

OBJECTIVE: To establish a method for the determination of notoginsenoside R1 in Radix Notoginseng. METHOD: The HPLC-ELSD method was used for the determination. Chromatographic conditions: Shimpack CLC-ODS column(6.0 mm x 150 mm), acetonitrile-water(30:70) as the mobile phase, and Shimadzu LC-6A with SEDEX 55 ELSD detector. RESULT: The recovery rate is 101.57% and relative standard deviation 1.98%. CONCLUSION: The method is reliable for the quality control of Radix Notoginseng.

Chromatography, High Pressure Liquid↗
PubMed2000

[The influence of basic fibroblast growth factor on the adhesion characteristics of osteoblasts in rabbit].

OBJECTIVE: To investigate the influence of basic fibroblast growth factor (bFGF) on adhesion characteristics of osteoblasts, aimed at the important problem in bone tissue engineering of how to promote the adherence of osteoblasts to extracellular matrix materials. METHODS: 5 ng/ml, 10 ng/ml, 50 ng/ml, 100 ng/ml, 200 ng/ml bFGF were used to induce bone marrow stromal-derived osteoblasts of rabbit for 24 hours before incubation, and the common culture medium as the control. The attached cells were calculated with stereology method at 0.5 hour, 1st hour, 2nd hour, 4th hour, 8th hour after seeding. RESULTS: The number of attached cells was significant higher in the experimental group when induced by 10 ng/ml bFGF than that in the control group (P < 0.01); the number did not increase with the increase of bFGF concentration and there was no significant difference between the experimental group induced by 100 ng/ml bFGF and control group, and the number was even obviously lower in the experimental group when induced by 200 ng/ml than the control group (P < 0.01). CONCLUSION: bFGF can influence the adhesion characteristics of osteoblasts, 10 ng/ml bFGF can promote the adherence of osteoblasts to matrix materials, but 200 ng/ml bFGF may inhibit cell adhesion.

Animals↗
PubMed2000

[Geometrical analysis of operative designs in unilateral cleft lip repair].

OBJECTIVE: To study the differences in geometric principle in cleft lip repair between Millard and Tennison-Randall's method. METHODS: The moving patterns of the peaks of cupid's bow along the cleft on both sides varied according to the operative designs respectively. On the above basis, the larger vertical distance that the peaks of cupid's bow would drop in both operative designs respectively, which were calculated under the similar clinical conditions. RESULTS: It was found that the most obvious characteristic in Millard's design is to make the rotational axle on both cupid's bow peaks along the cleft drop farther away on the horizontal direction. However the Tennison-Randall's characteristic is to make the center of the rotational axle as near as possible to the cupid's bow peaks on the vertical direction. CONCLUSION: It is concluded that Millard's design conforms to the requirement of reconstructing the lip on the physiological aspect, but Tennison-Randall's design complies more on the geometric principles, which is the reason why both methods of cleft lip repair can not be replaced by each other. And this study will make both kinds of operation designs be applied clearly and easily.

Cleft Lip↗
PubMed2000

[Analysis of imidacloprid and damanlin by high performance liquid chromatography].

A new method for determination of imidacloprid and damanlin by using HPLC was established. It was carried out on a mu Bondapak C18 column (3.9 mm i.d. x 300 mm) with ACN-MeOH-H2O (60:10:30, V/V) as eluent and detected at 240 nm using photodiode array detector. The results of imidacloprid and damanlin were 3.71% and 15.65% respectively. The standard deviations for imidacloprid and damanlin were 0.88% and 0.76% respectively.

Animals↗
PubMed2000

[The roles of estrogen and progestin in epileptogenesis and their mechanisms of action].

Clinical data showed that periodic alterations of estrogen and progestin in some women patients with catamenial epilepsy might affect seizure susceptibility. In the present study, in order to explore the roles of estrogen and progestin in epilepsy and elucidate their mechanisms of action, we utilized animal seizure models induced by intracerebroventricular(i.c.v) coriaria lactone(CL) and intraperitoneal(i.p.) bemegride(Be), studied the effects of estrogen and progestin on central nervous system(CNS) functions in behavior, electrophysiological, cellular, molecular and gene levels by means of neuroelectrophysiology, flow cytometry, high performance liquid chromatography, immunocytochemical and in situ hybridization techniques. From our observation we concluded that ovarian hormones are neuroactive steroids and new neuromodulaters, they could affect the excitability of CNS by regulating immediate early genes, amino acid neurotransmitters and N-methyl-D-aspartate receptor(NMDAR).

Animals↗
PubMed2000

[A histopathologic and immunohistochemical study of 68 cases of hemangioblastoma].

The aim of this study was to evaluate the histologic characteristics of hemangioblastoma (HB) and investigate the histogenesis of its stromal cells. Sixty-eight cases of hemangioblastoma were studied by light microscopy and thirty-three cases were examined by immunohistochemical stainning. Forty-eight of the 68 patients were males and 20 were females. The average age was 37. Fifty-two cases (76.6%) had been present for two months to one year before the diagnosis was made. Sixty cases (88.2%) arose in the cerebellum. Fifty cases (73.5%) appeared as cystic nodules. Histologically, the 68 cases of HB were further categorized into three subtypes: typical (30 cases), cellular (21 cases) and reticular (17 cases). In 33 cases, the stromal cell were positive for NSE, but negative for F-VIII, UEA-1, GFAP and EMA. In summary, there are three essential histologic categories of hemangioblastoma, and its stromal cells may well have the characters of neuroendocrine differentiation.

Adolescent↗
PubMed2000

[Preparation of monoclonal antibodies against malaria through immunization of mice with recombinant plasmid DNA].

BALB/c mice were immunized by injection of recombinant plasmid DNA carrying MSP1-31 fragment of Plasmodium falciparum. After antiserum was induced, McAbs were prepared by fusing SP2/0 myeloma cells with spleen cells. Specific McAbs were detected in hybridoma culture supernatant and mouse ascites by ELISA, positive hybridomas were cloned by technique of limiting dilutions. Two McAbs, 9H9 and 8A2, against the malaria protein were produced and characterized. The titers of the two McAbs in acites were 1:10,000 and 1:2500 respectively. The Ig subclass of these McAbs was IgG1. Western blot test showed that the McAb specifically reacted with MSP1-31 antigen. These results proved that monoclonal antibodies could be produced by use of immunization of mice with plasmid DNA or DNA vaccine.

Animals↗
PubMed2000

[Nucleotide sequence analysis of E2 major protective antigen encoding region of 12 strains of hog cholera virus(HCV)].

cDNA fragments, of HCV envelope glycoprotein E2 major gene of 11 field strains isolated in China in different time and 1 French reference strain(Thiveral) were amplified respectively with RT-PCR method and sequenced. The fragments amplified located by the 5' 2485 to 2708 of E2 major domains B and C and encoded 75 amino acid residues of E2 glycoprotein. All the products amplifield by RT-PCR from 12 strains in the study were same size of 224 bp. Comparing 12 sequences with other 9 references strains sequence reported before using software DNAstar, it was found that Hog Cholera Virus could be classified in two groups by analysis of phylogenetic tree. Strains Brescia, Gpe, Ald, Thiverval, C, CW, HCLV, HCVSM, BJCY1/96, BJTX3/96, BJSY2/96, HeNXH2/98, HeNZZ1/82 and GDGZ1/95 were assigned to group A and were 85.7%-100% for nucleotide sequence and 83.8%-100% for amino acid sequence in homology; but strains HCVF98, HCVF94, HeBHH2/95, LN1/84, SZGM1/85, SCCD1/79 and Alfort were assigned to group B and were 84.3%-100% for nucleotide sequence and 85.1%-100% for amino acid sequence in homology; and 21 strains of HCV were 78.1%-100% for nucleotide sequence and for 78.4%-100% amino acid sequence in homology. Homology were 99.1% for nucleotide sequence and 100% for amino acid sequence between strains HCLV in our study and strains C reported by Rijn's in the Netherlands. It's showed our method of sequencing is reliable. There were obvious differences between the two groups in sequences of envelope glycoprotein E2 major gene, especially in the amino acid substitutions of sites 713 and 729 respectively, and it is showed the two groups of HCV field strains might vary genetically in some extents. The results of other report of challenging of the partial field strains showed that the Chinese stock vaccine virus(HCLV) has good immunity.

Amino Acid Sequence↗
PubMed2000

[The mechanism of bone formation promoted by mechano-electrical environments--current studies on local bone factors].

The mechanism for promoting bone formation under the mechanical and the electromagnetical fields stimulation is not yet quite clear. In recent years, it has been found the mechanical and electromagnetical environments may induce the osteogenic cells to produce some local bone factors, such as prostaglandin E2(PGE2), insultine-like growth factors-II (IGF-II), bone morphogenetic protein (BMP) and transforming growth factor beta (TGF-beta). These factors play an important role in bone formation and remodeling. This article introduces current studies on some of these local bone factors under the stimulation of the mechanical and electromagnetical environments.

Bone Morphogenetic Proteins↗
PubMed2000

[Mechanisms of opioid receptor-induced elevation in intracellular calcium by confocal laser scanning microscopy].

OBJECTIVE: To determine the acute and chronic effects of opioid receptor agonists on the intracellular free calcium concentration ([Ca2+]i) in NG-LNCXiNOS cells, stably expressing iNOS gene, and regulation of G-protein on opioid-induced response in [Ca2+]i. METHODS: A single cell [Ca2+]i is measured by confocal laser scanning microscopy using Ca(2+)-sensitive dye Fluo-3 as an new calcium fluorescent probe. RESULTS: DPDPE(D-Pen2, D-Pen5-enkephalin), a delta-opioid receptor agonist, and morphine acutely induced the increase in [Ca2+]i of NG-LNCXiNOS cells. The elevation in [Ca2+]i by DPDPE could be abolished with naloxone. Pretreatment of the cells with pertussis toxin (PTX) at 100 ng/ml for 24 hours almost completely blocked morphine-evoked response. In contrast to acute effect of opioid agonists on [Ca2+]i, the cells exposed to 1 mumol/L DPDPE or 10 mumol/L morphine for 48 hours also appeared to raise [Ca2+]i. However, the elevation in [Ca2+]i was not greater than that caused by acute effect of DPDPE or morphine. After cell "withdrawal" was precipitated by the addition of 10 mumol/L naloxone, the increase in [Ca2+]i could further be intensified. CONCLUSIONS: The opioid agonist-induced increase in [Ca2+]i is mediated by opioid receptor and regulated though PTX-sensitive G-protein. The attenuation of this response in chronically treated cells with opioid agonist is associated with receptor desensitization.

Calcium↗
PubMed2000

[Changes of AC/cAMP system and phosphorylation regulation of adenylate cyclase activity in brain regions from morphine-dependent mice].

OBJECTIVE: To further understand the changes of AC/cAMP system in the brain regions from morphine-dependent mice. METHODS: By inducing morphine dependence in mice, we observed changes in AC/cAMP signal system, the phosphorylation regulation of adenylate cyclase (AC) activity in brain regions and effect of protein kinase A (PKA) inhibitor on the development of morphine dependence. RESULTS: (1) In morphine-dependent mice, AC activity, cAMP contents, and cytosolic PKA activity in striatum, hippocampus, and cerebral cortex were significantly higher than those of control. But there were no similar changes in cerebellum, and PKA inhibitor injected intracerebroventricular 15 min prior to morphine injection could inhibit the changes of AC activity; (2) These changes described above were not observed in mice treated with naloxone 30 min prior to daily morphine injection; (3) In striatum and cerebral cortex of morphine-dependent mice, level of AC phosphorylation in vitro was apparently higher as compared to control group. It indicated that the level of AC phosphorylation in vivo was decreased in morphine-dependent mice; (4) PKA inhibitor was given to mice intracerebroventricular (i.c.v.) 15 min. prior to daily morphine injection could prevent the development of morphine dependence in mice. CONCLUSIONS: The up-regulation of AC/cAMP-PKA signal system in some brain regions occurred in the state of morphine dependence and the effect was mediated via specific activation of opiate receptors. Furthermore, that PKA affecting AC phosphorylated state and leading to the increase of AC activity suggest that the increase of PKA activities during chronic morphine treatment could lead to the positive feedback regulation in AC/cAMP system and further potentiate the AC/cAMP system, and these may be one of important mechanisms by which chronic opiate induce dependence in target neurons.

Adenylyl Cyclases↗
PubMed2000

[Association of microtubule promoting and binding activity of tau with its phosphorylation sites].

OBJECTIVE: To explore the association between the abnormal phosphorylation sites found in Alzheimer disease (AD) tau and the inhibition of its biological activity. METHODS: Ultracentrifugation, chromatography, manual Edman degradation and autosequence techniques were used to prepare and phosphorylate human recombinant tau, isolate and purify 32P tau peptides and determine phosphorylation sites. RESULTS: (1) Phosphorylation of tau by casein kinase-1 (CK-1), cyclic AMP-dependent protein kinase (PKA) and glycogen synthetase kinase-3 (GSK-3) differentially inhibited its biological activity, and the inhibition of this activity of tau by GSK-3 was significantly increased if tau was prephosphorylated by CK-1 or PKA. The most potent inhibition was seen by a combined phosphorylation of tau with PKA and GSK-3. (2) The treatment of tau by PKA and GSK-3 combination induced phosphorylation of tau at Ser-195, Ser-198, Ser-199, Ser-202, Thr-205, Thr-231, Ser-235, Ser-262, Ser-356, Ser-404, whereas only Thr-181, Ser-184, Ser-262, Ser-356 and Ser-400 were phosphorylated by GSK-3 alone under the same conditions. Among the above-mentioned phosphorylation sites, Ser-198, Ser-199, Ser-202, Thr-205, Thr-231, Ser-235, Ser-262, Ser-400 and Ser-404 were seen in Alzheimer tau. The phosphorylation of Ser-262 only slightly inhibited its biological activity, and Ser-198, Ser-199, Ser-202, Thr-231, Ser-235, Ser-400 and Ser-404 also presented in fetal tau which was highly active, suggesting that Thr-205 was the unique site which both caused the potent inhibition of biological activity and specifically presented in AD abnormally phosphorylated tau. CONCLUSIONS: Phosphorylation of Thr-205 might play a key role in tau pathology in AD.

Alzheimer Disease↗
PubMed2000

New perspectives on anti-HER2/neu therapeutics.

HER2/neu and the epidermal growth factor receptor (EGFR) are significantly overexpressed in several cancer cells. Overexpression of these two receptors accounts for progression of many types of cancer: breast, ovarian, skin, pancreas and brain. In recent years, several approaches to disable the receptor complexes have shown promise. Antibody-based therapy, kinase inhibitors and other inhibitors of signaling molecules are the major approaches. Our group developed the concept that an anti-p185HER2/neu monoclonal antibody might represent a therapeutic for cancer and this has culminated in a clinically useful therapeutic, the humanized monoclonal antibody Herceptin (trastuzumab). We have now developed a small-molecule form of an anti-HER2/neu peptidomimetic (AHNP) that exhibit functions comparable to those of the monoclonal antibody Herceptin. This approach may be considered a new paradigm in receptor-specific tumor therapeutics. A brief review of our approach in developing receptor-specific therapeutic agents for HER2/neu-related cancer is presented.

Journal Article↗
PubMed2000

[The analysis of linseed oil by FTIR and FT-Raman].

Linseed oil is an important natural sanitarian oil. To qualitative analyses the linseed oil, FTIR and FT-Raman were used to identify the contents of it. It is indicated that each component has characteristic frequency, and can be discriminated from others by IR and Raman spectroscopy. This is useful for the further on-line quantitative analysis and quality control of linseed oil.

Fourier Analysis↗
PubMed2000

[Spectroscopy and structure of the zinc complexes with mixed ligands].

The negative ion, MS4(2-) (M = Mo, W, V ect.), is used widely in molecule designed as construction fragment because of its various ligand mode. The IR and Raman spectra of the crystals Zn(phen)2 WS4 and Zn(phen)2MoS4 with mixed ligands MS4(2-) and 1, 10-phenanthroline have been investigated, and the coincidence between the spectrum and the structure has been discussed as well.

Chelating Agents↗
PubMed2000

[A new chemiluminescence immunoassay method for the determination of cancer embryo antigen].

A new chemiluminescent probe 10,10'-dimethyl-3,3'-disulfo-9,9'-biacridine DMDSBA) is used to label anti-CEA antibody, the molar incorporation is 1.15-1.32 mole of DMDSBA per mol anti-CEA; the conditions of labeling reaction, sandwich immunoassay and chemiluminescent reaction are studied. Moreover, a new double antibody sandwich chemiluminescence immunoassay is firstly established, the linear calibration ranges is 1.5-150.0 ng.mL-1 and the detection limit is 0.53 ng.mL-1. This method is used to detect cancer embryo antigen (CEA) in human serum, the results are well-matched with that of radio immunoassay.

Carcinoembryonic Antigen↗