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Biomedical subjects

G Wang

Publications and source records attributed to G Wang.

At least 307 records · Page 17Linked to original sources
PubMed2000

[Expression of lipofect AMINE mediated human GM-CSF eukaryotic expressing vector in HFCL cells].

OBJECTIVE: To construct an eukaryotic expressing vector-pIRES1neo/hGM-CSF and express it in human bone marrow stromal cell line HFCL. METHODS: Human granulocyte/macrophage colony-stimulating factor cDNA (hGM-CSF cDNA, 751 bp) was inserted into an effective eukaryotic expressing vector-pIRES1neo which contains the human cytomegalovirus (CMV) major immediate early promoter/enhancer and the internal ribosome entry site (IRES) of the encephalomyocarditis virus (ECMV). HFCL cells were transfected with the recombinant vector pIRES1neo/hGM-CSF by liposome-mediated gene transfer method. Integration of hGM-CSF in the genome, transcription of its mRNA and expression of its protein in the transfected HFCL cells were assayed by Southern blot, Northern blot, ELISA and hGM-CSF dependent cell line TF-1. RESULTS: hGM-CSF cDNA was integrated into HFCL genome successfully, hGM-CSF mRNA was transcripted and hGM-CSF protein was expressed of (56.9 +/- 0.7) ng/10(6) cells by ELISA and (6.56 +/- 0.16) x 10(3) U/10(6) cells per day by TF-1 cell assay in the supernatant. CONCLUSION: The recombinant vector is proved to be stably expressed in HFCL cells and the biological activity of hGM-CSF was detectable in the supernatant of the transfected cells.

Blotting, Northern↗
PubMed2000

[Experimental study on treatment of chronic renal failure with yishen qudu capsule].

OBJECTIVE: To study the mechanism of action of Yishen Qudu capsule (YSQDC) in experimental rat model of chronic renal failure (CRF). METHODS: Membranous nephropathy model was induced by cationized bovine serum albumin intravenous administration in rats for 7 weeks and developed to CRF. The model was then treated with YSQDC of large or small dose by gastrogavage for 5 weeks. Oxidated starch was used in the control group. RESULTS: YSQDC could reduce proteinuria, serum creatinine, blood urea nitrogen, total cholesterol, triglyceride and serum circulating immune complex (P < 0.01 or P < 0.05), it also reduced the kidney coefficient, glomerular cells and tubular protein cast significantly (all P < 0.01). The strength of immune fluorescence weakened remarkably (P < 0.01). The pathological lesions improved significantly after treatment under light and electron-microscopic examination. CONCLUSION: YSQDC could improve renal function significantly and inhibit the progression of CRF.

Animals↗
PubMed2000

[Study on improvement of liver cirrhosis and liver function in hepatolenticular degeneration patients treated with integrated Traditional and Western medicine].

OBJECTIVE: To observe the effects of sodium dimercaptosulphonate (DMPS) plus Gandou tablet, DMPS and calcium disodium ethylene diaminotetraacetate (EDTA) on improving liver cirrhosis and liver function of hepatolenticular degeneration (HLD) patients. METHODS: One hundred and forty-six HLD patients were divided into A, B, C three groups, and treated with DMPS plus Gandou tablet, DMPS and EDTA respectively, the therapeutic course was 8 weeks for three groups. The ultrasonography of liver, electrophoresis of serum protein and excretion of urinary copper were observed. RESULTS: The ultrasonography of liver was improved in all groups, the rate of improvement of group A was 54.0%, B was 44.0% and C was 39.1%. The amounts of serum albumin in A and B groups increased (P < 0.01, P < 0.05), and gamma-globulin decreased in all groups (P < 0.05). The excretion of urinary copper increased obviously in all groups (P < 0.01), and A, B groups increased more than that of C group (P < 0.05). CONCLUSIONS: The de-copper therapy could improve liver cirrhosis and liver function. The effect of DMPS plus Gandou tablet was better than that of DMPS and EDTA.

Adolescent↗
PubMed2000

[Pharmacognostical identification of antelope horn(Cornu Saigae Tataricae) and its adulterants].

OBJECTIVE: To provide appropriate information and scientific basis for identifying antelope horn (Saiga tatarica) contained in traditional Chinese patent medicines, and formulate relevant quality criteria through experiments. METHOD: Conducting comparative identification of macroscopic and microscopic characteristics of antelope horn(Saige tatarica) and its adulterants (Procapra gutturosa, Pantholops hodgsoni, Ovis ammon and Capra hircus) and giving a comparative table and an indented key to the main characteristics. RESULT AND CONCLUSION: There are remarkable differences between the authentic product and adulterants in both macroscopic and microscopic characteristics.

Animals↗
PubMed2000

[Analysis of maxillary dental-arch dimensions in adult unoperated cleft palate patients].

OBJECTIVE: Analysis of maxillary dental-arch development in adult unoperated cleft palate patients. METHODS: Dental casts was studied in 20 cases of adult unoperated cleft palate (UCP) patients, and 20 cases of normal adults were as a control group. RESULTS: The UCP group showed smaller dental-arch widths than a control group in the canine region (P < 0.05) and these was no significant difference on upper-arch depth and posterior dental arch widths between the UCP group and a control group (P > 0.05). CONCLUSION: In the UCP group major deformity were in incisor and canine region, and smaller interfere to posterior dental-arch widths and depth. Operation for cleft lip can interfere maxillary dental-arch development.

Adolescent↗
PubMed2000

[Relationships between ankylosing spondylitis and ear disease].

OBJECTIVE: To explore whether patients with ankylosing spondylitis (AS) have hearing loss and the pattern of hearing loss. METHODS: Questionnaire, physical examination of the ear, nose and throat, hearing test and sero-immunity examinations were conducted in 34 patients (68 ears) with AS. RESULTS: Among 34 patients, 11 cases reported decrease in the sound perception, and 24 cases (41 ears, 60.3%) had hearing loss as evidenced by the pure tone audiometry. In those patients with hearing loss, 2 ears with perforation of tympanic membrane showed conductive hearing loss and the remainder 39 ears showed sensorineural hearing loss in which 26 ears (66.7%) experienced high frequency hearing loss. Auditory brainstem responses were normally presented in 26 case, whereas abolished in 1 case (2 ears) with severe hearing loss. Examinations of sero-immunity showed a positive response in HLA-B27, but negative responses in the antinuclear antibody and rheumatoid factor. The percentage of the C-reactive protein increase was 81.8%. Autoantibodies anaginst the inner ear were positive in 9 cases (28.1%). In addition, all other immunological examinations revealed certain changes. CONCLUSION: More than half of the patients with AS had sensorineural hearing loss, particularly in the high frequency range. This hearing loss is paralleled by abnormal immunology and is a local expression of systemic autoimmune disease. Therefore, periodical hearing tests are necessary for these patients.

Adolescent↗
PubMed2000

[Study on the interaction of Rhus vernicifera laccase with Hg2+ ion].

The influence of the mixed time of Hg2+ ion and Rhus vernicifera laccase on the oxidation of 5,6-dibromo-2,3-dicyanohydroquinone (DDBQH2) catalyzed by laccase has been studied at pH 4.4 and 30 +/- 0.2 degrees C. Hg2+ ion can activate the catalytic activity of laccase when the mixed time is short. With the extension of the mixed time, the activation is gradually converted into inhibition. The influence of Hg2+ ion on the absorption spectrum of laccase suggests that it may be the substitution that Hg2+ ion displaces Cu(II) from the type 1 site in laccase causing the inhibition of laccase activity.

English Abstract↗
PubMed2000

[Photoluminescence characteristics of mixed aggregates in Langmuir-Blodgett multilayers].

Effects of the mixed aggregates of different active molecules and UV illumination on photoluminescence(PL) spectra of Langmuir-Blodgett multilayers were investigated. The strong interaction between hemicyanine and stilbazolium salt molecules in the mixed films caused a blue or red shift of the fluorescence band with respect to that of interleaving hemicyanine or stilbazolium salt/arachidic acid multilayers. UV illumination would dissociate the aggregates even more destroy the molecular structure, leading to a significant reduction of fluorescence intensity.

English Abstract↗
PubMed2000

[Solution of inverse problem of therman equation in quantitative X-ray fluorescence analysis. Theoretical effect coefficient method and fundamental parameter method].

In this paper, firstly the algorithmic relation between the weight fraction Ci, X-ray fluorescence relative intensity Ri and matrix effect factor Fi is created for the multi-element specimen on theoretical basis. Secondly, according to this algorithm relation, the typical method to solve inverse problem of Therman equation can be developed that is the theoretical influence coefficience method and the fundamental parameter method. Six standards are analysed by these two methods respectively, and results are good agree with the certified values.

English Abstract↗
PubMed1999

Simultaneous determination of alpha-fetoprotein and carcinoembryonic antigen in human serum by time-resolved fluoroimmunoassay.

A novel simultaneous measurement method for alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) in human sera by time-resolved fluoroimmunoassay (TR-FIA) is described. The proposed approach combines the use of europium-labeled anti-AFP antibody for AFP TR-FIA and biotinylated anti-CEA antibody complexed to samarium-labeled streptavidin for CEA TR-FIA. A 96-well microtiter plate coated with a mixture of anti-AFP and anti-CEA monoclonal antibodies was used for the assay. After it was reacted with a solution containing AFP and CEA, a mixture of anti-AFP antibody labeled with BHHCT-Eu(3+) and biotinylated anti-CEA antibody was added. The AFP concentration was determined by measuring the solid-phase fluorescence of the europium-labeled anti-AFP antibody at 615 nm. Then a BHHCT-Sm(3+)-labeled streptavidin-bovine serum albumin conjugate (SA-BSA) was added to react with the biotinylated anti-CEA antibody. After the reaction, the unreacted SA-BSA was washed out, and a 0.1 M NaOH solution containing 1.0 x 10(-5) M TOPO and 0.05% SDS was added to dissociate the samarium-labeled SA-BSA in the immune complex on the surface of the well into the solution. The CEA concentration was determined by measuring the solution fluorescence of 643 nm from the samarium-labeled SA-BSA. The present method gives detection limits of 0.07 ng/ml for AFP and 0.3 ng/ml for CEA. The coefficient variations of the method are less than 7%, and the recoveries are in the range of 90-110% for serum samples. The AFP and CEA concentrations in 27 human serum samples were determined by the present method as well as by single assay for comparison. A good correlation was obtained with the correlation coefficients of 0.990 for AFP and 0.973 for CEA.

Animals↗
PubMed1999

Human RNA helicase A is a lupus autoantigen that is cleaved during apoptosis.

Proteolytic cleavage by caspases is the central event in cells undergoing apoptosis. Cleaved proteins are often targeted by autoantibodies, suggesting that the cleavage of self Ags enhances immunogenicity and is prone to induce an autoimmune response. We found autoantibodies that immunoprecipitated a 140-kDa RNA-associated protein, provisionally designated Pa, in 11 of 350 patient sera that were positive for antinuclear Abs in an immunofluorescence test. The Pa protein gave rise to three fragments with m.w. ranging from 120-130 kDa during anti-Fas-activated apoptosis. Pure caspase-3 cleaved the Pa protein into a 130-kDa fragment corresponding to the largest of these three products. Peptide sequence analysis of a tryptic digest from immunoaffinity-purified Pa showed 100% identity to human RNA helicase A (RHA). The identity of Pa with RHA was further confirmed by immunoblotting with rabbit anti-RHA Ab using anti-Pa immunoprecipitates as substrates. All 10 anti-RHA-positive patients who were clinically analyzed were diagnosed as having systemic lupus erythematosus, and 7 of them had lupus nephritis. RHA is a multifunctional protein with roles in cellular RNA synthesis and processing. Inactivation of RHA by cleavage may be an important part of the process leading to programmed cell death. The cleaved RHA fragments that are produced during apoptosis may trigger an autoimmune response in systemic lupus erythematosus.

Amino Acid Sequence↗
PubMed1999

Case study of the effects of atmospheric aerosols and regional haze on agriculture: an opportunity to enhance crop yields in China through emission controls?

The effect of atmospheric aerosols and regional haze from air pollution on the yields of rice and winter wheat grown in China is assessed. The assessment is based on estimates of aerosol optical depths over China, the effect of these optical depths on the solar irradiance reaching the earth's surface, and the response of rice and winter wheat grown in Nanjing to the change in solar irradiance. Two sets of aerosol optical depths are presented: one based on a coupled, regional climate/air quality model simulation and the other inferred from solar radiation measurements made over a 12-year period at meteorological stations in China. The model-estimated optical depths are significantly smaller than those derived from observations, perhaps because of errors in one or both sets of optical depths or because the data from the meteorological stations has been affected by local pollution. Radiative transfer calculations using the smaller, model-estimated aerosol optical depths indicate that the so-called "direct effect" of regional haze results in an approximately 5-30% reduction in the solar irradiance reaching some of China's most productive agricultural regions. Crop-response model simulations suggest an approximately 1:1 relationship between a percentage increase (decrease) in total surface solar irradiance and a percentage increase (decrease) in the yields of rice and wheat. Collectively, these calculations suggest that regional haze in China is currently depressing optimal yields of approximately 70% of the crops grown in China by at least 5-30%. Reducing the severity of regional haze in China through air pollution control could potentially result in a significant increase in crop yields and help the nation meet its growing food demands in the coming decades.

Agriculture↗
PubMed1999

Reversible molecular adsorption based on multiple-point interaction by shrinkable gels.

A general approach is presented for creating polymer gels that can recognize and capture a target molecule by multiple-point interaction and that can reversibly change their affinity to the target by more than one order of magnitude. The polymers consist of majority monomers that make the gel reversibly swell and shrink and minority monomers that constitute multiple-point adsorption centers for the target molecule. Multiple-point interaction is experimentally proven by power laws found between the affinity and the concentration of the adsorbing monomers within the gels.

Adsorption↗
PubMed1999

Structure of an E6AP-UbcH7 complex: insights into ubiquitination by the E2-E3 enzyme cascade.

The E6AP ubiquitin-protein ligase (E3) mediates the human papillomavirus-induced degradation of the p53 tumor suppressor in cervical cancer and is mutated in Angelman syndrome, a neurological disorder. The crystal structure of the catalytic hect domain of E6AP reveals a bilobal structure with a broad catalytic cleft at the junction of the two lobes. The cleft consists of conserved residues whose mutation interferes with ubiquitin-thioester bond formation and is the site of Angelman syndrome mutations. The crystal structure of the E6AP hect domain bound to the UbcH7 ubiquitin-conjugating enzyme (E2) reveals the determinants of E2-E3 specificity and provides insights into the transfer of ubiquitin from the E2 to the E3.

Amino Acid Sequence↗
PubMed1999

Protein kinase A antagonizes Hedgehog signaling by regulating both the activator and repressor forms of Cubitus interruptus.

The Hedgehog (Hh) family of secreted proteins controls many aspects of animal development. In Drosophila, Hh transduces its signal via Cubitus interruptus (Ci), a transcription factor present in two forms: a full-length activator and a carboxy-terminally truncated repressor that is derived from the full-length form by proteolytic processing. The proteolytic processing of Ci is promoted by the activities of protein kinase A (PKA) and Slimb, whereas it is inhibited by Hh. Here we show that PKA inhibits the activity of the full-length Ci in addition to its role in regulating Ci proteolysis. Whereas Ci processing is blocked in both PKA and slimb mutant cells, the accumulated full-length Ci becomes activated only in PKA but not in slimb mutant cells. Moreover, PKA inhibits an uncleavable activator form of Ci. These observations suggest that PKA regulates the activity of the full-length Ci independent of its proteolytic processing. We also provide evidence that PKA regulates both the proteolytic processing and transcriptional activity of Ci by directly phosphorylating Ci. We propose that phosphorylation of Ci by PKA has two separable roles: (1) It blocks the transcription activity of the full-length activator form of Ci, and (2) it targets Ci for Slimb-mediated proteolytic processing to generate the truncated form that functions as a repressor.

Animals↗
PubMed1999

An R-type Ca(2+) current in neurohypophysial terminals preferentially regulates oxytocin secretion.

Multiple types of voltage-dependent Ca(2+) channels are involved in the regulation of neurotransmitter release (Tsien et al., 1991; Dunlap et al., 1995). In the nerve terminals of the neurohypophysis, the roles of L-, N-, and P/Q-type Ca(2+) channels in neuropeptide release have been identified previously (Wang et al., 1997a). Although the L- and N-type Ca(2+) currents play equivalent roles in both vasopressin and oxytocin release, the P/Q-type Ca(2+) current only regulates vasopressin release. An oxytocin-release and Ca(2+) current component is resistant to the L-, N-, and P/Q-type Ca(2+) channel blockers but is inhibited by Ni(2+). A new polypeptide toxin, SNX-482, which is a specific alpha(1E)-type Ca(2+) channel blocker (Newcomb et al., 1998), was used to characterize the biophysical properties of this resistant Ca(2+) current component and its role in neuropeptide release. This resistant component was dose dependently inhibited by SNX-482, with an IC(50) of 4.1 nM. Furthermore, SNX-482 did not affect the other Ca(2+) current types in these CNS terminals. Like the N- and P/Q-type Ca(2+) currents, this SNX-482-sensitive transient Ca(2+) current is high-threshold activated and shows moderate steady-state inactivation. At the same concentrations, SNX-482 blocked the component of oxytocin, but not of vasopressin, release that was resistant to the other channel blockers, indicating a preferential role for this type of Ca(2+) current in oxytocin release from neurohypophysial terminals. Our results suggest that an alpha(1E) or "R"-type Ca(2+) channel exists in oxytocinergic nerve terminals and, thus, functions in controlling only oxytocin release from the rat neurohypophysis.

Animals↗
PubMed1999

HIV mediates a productive infection of the brain.

BACKGROUND: Approximately one quarter of patients with AIDS develop severe cognitive deficits called HIV-associated dementia complex. There is some controversy regarding the importance of viral load and distribution in mediating this neurologic disease. OBJECTIVE: Brain HIV proviral and RNA loads were compared to define the molecular nature of HIV infection of the brain. METHOD: Neuropathologic examination was performed on brains from 10 autopsies of patients with AIDS that had short post-mortem intervals and no evidence of opportunistic infection. Viral DNA and RNA were extracted and quantified from multiple brain regions. These findings were compared with triple-label immunofluorescence for viral and cell markers. RESULTS: Brains with histopathologic evidence of HIV encephalitis contained abundant HIV RNA and DNA. Regions without productive HIV infection showed minimal proviral load. By immunocytochemistry, only brain macrophages/microglia double labeled for viral proteins. CONCLUSIONS: HIV mediates a productive infection of brain macrophages/microglia. There was no evidence supporting the hypothesis of substantial neuronal or macroglial infection, or evidence of substantial proviral burden prior to the development of productive infection.

AIDS Dementia Complex↗