Search PubMed⌕ Search

Biomedical subjects

G Wang

Publications and source records attributed to G Wang.

At least 181 records · Page 10Linked to original sources
PubMed2001

[A study on the myocardial contractile function and intracellular free calcium in scalded rats].

OBJECTIVE: To explore the relationship between postburn myocardial function and intracellular free calcium concentration. METHODS: Sprague-Dawley (SD) rats were employed as the model in which 7 were inflicted with 43% TBSA degree scalding (S group) and 7 as sham scalding control group (C group). The hearts of the injured rats were isolated and perfused in vitro by Langendorff method after 24 postburn hours (PBHs). The hearts were connected to a cardiac function monitor, and the dynamic changes in left ventricular develop pressure (LVDP) were continuously monitored. The cardiac 19F and 31P NMR spectroscopy was determined before and after and TF-BAPTA was added to the perfusate. RESULTS: When compared with those in C group, the LVDP of scalded rat heart decreased by 40% (P < 0.01), and the myocardial cytoplasmic free calcium concentration was four times above that in C group (P < 0.01). After TF-BAPTA was taken by myocytes, cardiac LVDP only decreased by 15% to 20%, and the PCr/Pi ratio decreased, while there was no change in ATP. CONCLUSION: Myocardial contractile function could be inhibited after burn injury, which might be related to the increase of myocardial cytoplasmic free calcium concentration.

Animals↗
PubMed2001

[The study of low dose radiation inducing hormesis effect on hematopoietic system].

OBJECTIVE: To study the hormesis effect on hematopoietic system induced by low dose radiation. METHOD: CFU-GM and BFU-E were cultured in methylcellulose semi-solid culture system, levels of GM-CSF and IL-3 were assayed by ELISA and mRNA levels of GM-CSF, G-CSF, IL-3 by in situ hybridization, narrow line hybridization and Northern blot. RESULTS: (1) The in vitro yields of CFU-GM and BFU-E from radiated mice was higher than that from the control. (2) The serum protein level of GM-CSF increased obviously than that of controls; (3) mRNA levels of GM-CSF and G-CSF were also increased. CONCLUSION: There is hormesis effect on hematopoietic system induced by low dose radiation, which may be related to the increasing of cytokines.

Animals↗
PubMed2001

[The preliminary study on the oxide film of pure titanium treated by anodic oxidation].

OBJECTIVE: To study the oxide film of pure titanium implant material treated by anodic oxidation and to learn the effect of anodic oxidation on it. METHODS: Six titanium sheets, which were ground, polished and pretreated, were treated by anodic oxidation at 10 v, 24 v or 40 v for 10 minutes and at 24 v for 10 minutes, 40 minutes or 2 hours. The microstructures and the corrosive-resistance of oxide films were studied by means of X-ray diffraction and electro-chemical corrosion. RESULTS: The results of X-ray diffraction showed that the titanic peaks of 2.55 and 2.34 inverted as potential went up. Not many disorderly peaks of titanium oxide were found. And all the peaks of 2.55 and 2.34, 1.25 and 1.23, 1.72 and 1.47 did the same when time went on. Disorderly peaks of titanium oxide first appeared more and then fewer. The open loop potential of the oxide film treated by anodic oxidation moved positively, and polarized current was a 100'th of that of natural oxide film. CONCLUSIONS: The oxide film with a certain color and crystallinity could be controlled by the potential and time. The corrosive-resistance of the oxide film is greatly improved by means of anodic oxidation. It will be the next study how to utilize and adjust the rule of titanium crystal corrosion.

Dental Implants↗
PubMed2001

[Screening and characterization of human phage antibody to hepatitis virus C NS5A antigen].

OBJECTIVE: To screen and characterize human phage antibody against hepatitis C virus (HCV)NS5A antigen. METHODS: The recombinant phages were panned by recombinant HCV NS5A antigen which was coated in a microtiter plate; after five rounds of biopanning, 35 clones were obtained and demonstrated specific to NS5A antigen. The specific binding capacity of the ScFv antibody to HCV NS5A antigen was determined by ELISA. RESULTS: HCV NS5A phage antibody had a specific combination capacity with hepatitis C virus NS5A antigen. The DNA sequence data showed that the ScFv gene was composed of 789 bp and codes for a peptide of 262 amino acid residues. CONCLUSIONS: Human single chain antibody to hepatitis C virus NS5A antigen has been identified by means of the phage display technology.

Antibodies, Viral↗
PubMed2001

Effect of buyang huanwu decoction on platelet activating factor content in arterial blood pre- and post-arterial thrombosis in rats.

To explore the effect of Buyang Huanwu Decoction (BHD) on platelet activating factor (PAF) content in arterial blood pre- and post-arterial thrombosis in rats, male Wistar rats were randomly divided into 3 groups, the medicine group treated with BHD, the control group with dexamethasone liquid, and the blank group with distilled water. Oral administration was given for 14 consecutive days, once daily. Model of arterial thrombosis was established in the animals 2 hours after final medication, the blood content of PAF, dry weight (DW) and occlusion time (OT) of thrombus, and dry weight of thrombus/body weight (TW/BW) ratio were observed. Results indicated that BHD could markedly lower the arterial blood content of PAF after thrombosis, increase the OT of thrombus, reduce the dry weight of thrombus and the TW/BW ratio (P < 0.05). It is suggested that BHD can inhibit the pathologic PAF metabolism and formation and development of arterial thrombus.

Animals↗
PubMed2001

[Determination of trace amount of cadmium with vapor generation and atomic absorption spectrometry].

OBJECTIVE: This study aimed to establish a sensitive method for the determination of trace amount of cadmium. METHODS: The reaction systems for the generation of volatile cadmium species were investigated with vapor generation and atomic absorption spectrometry. RESULTS: It was found that potassium ferricyanide with hydroxylamine hydrochloride greatly enhanced the generation efficiency of the volatile species. The reaction parameters using ferricyanide-hydroxyamine-tetrahydroborate in acidic acqueous solution were optimized for efficient generation of volatile cadmium species. A detection limit (3 sigma blank, peak height mode) of 11 pg/ml was obtained under optimized conditions. The RSD of the determinations for 0.2 ngCd/ml was 3.4%. The effects of 33 diverse ions on the generation of the cadmium volatile species were investigated. The method was applied to the determination of cadmium in standard reference materials, the results obtained were in good agreement with the certified values. CONCLUSION: The method can be applied to the determination of trace cadmium in environment and food samples.

Cadmium↗
PubMed2001

[Evaluation of the effects of two operative option in the treatment of orbital fractures].

OBJECTIVE: In order to explore the treatment and it's clinical effects of orbital fractures. METHOD: 34 patients were separately treated with nasal endoscopic surgery and external nose incision surgery. RESULT: The total effective rate of nasal endoscopic surgery and external nose incision surgery was 90.0%, 91.6% respectively. There was no significant difference between the two groups (P > 0.05). CONCLUSION: Treating orbital fractures under nasal endoscopic surgery has advantages such as no incision on face, less damage, clear view and easy recheck after operation. It is the best way to treat this kind of disease.

Adolescent↗
PubMed2001

[Uvulopalatopharyngoplasty for the treatment of obstructive sleep apnea syndrome in 70 cases].

OBJECTIVE: To elevate the effect of uvulopalatopharyngoplasty (UPPP) and minimize the postoperative complications. METHOD: The data of 70 patients with obstructive sleep apnea syndrome diagnosed with polysomnography were analyzed. RESULT: 15 cases (21%) reported unchanged snoring and apnea and hyponea index. 55 cases improved after UPPP for at least 6 months. The complications included hypertensive crisis (2 cases), respiratory embarrassment (4 cases) in period of paretic UPPP. After UPPP, The complications included local hemorrhage (1 case), wound dehiscence (2 cases), temporal velopalatal insufficiency (9 cases), one had suffocation after extraction of endotracheal tube. CONCLUSION: Our results indicate that the strategies of improving the effect and avoiding the complications include: Excision of the lateral pharyngeal wall in retropalatal region and fat tissue in soft palate. Protection of palatosalpingeus and palatostaphylinus. Part preservation of uvula. Confirmation of the obstructive region. Choice of the anesthesia and preventive tracheotomy. Modified tracheotomy were safe and convenient when exchanging trachea canula.

Adult↗
PubMed2001

[The preliminary research of maxillary sinus cancer on oncogene level].

OBJECTIVE: To determine the oncogene c-myc, bcl-2' product expression in the maxillary sinus cancer and to investigate its clinical significance. METHOD: In 46 maxillary sinus cancer and 56 normal nasal mucous membrane, immunochemical method was adopted to determine oncogene c-myc and bcl-2' product. RESULT: In the normal nasal mucous membrane, the positive rates of oncogene c-myc and bcl-2' product were 0; in the maxillary sinus cancer, the positive rates of c-myc and bcl-2' product were 73.91 (34/46), 60.87 (28/46) respectively. The positive rate of c-myc' product in the relapse group(91.67%, 11/12) was significantly higher than that in the non-relapse group(67.65%, 23/34), P < 0.01; the positive rate of bcl-2' product in the relapse group(50%, 6/12) was significantly lower than that in the non-relapse group(64.71%, 22/34), P < 0.05; the positive rate of c-myc' product in the stage IV (88.89%, 8/9) was significantly higher than that in the stage II (63.64%, 7/11), P < 0.05; the positive rate of bcl-2' product in the stage II (72.73%, 8/11) was significantly higher than that in the stage IV (55.56%, 5/9), P < 0.05; the positive rate of bcl-2' product was in the negative correlation to the pathological grade of primary carcinoma. CONCLUSION: The oncogene c-myc and bcl-2 take part in the genesis and advancing course of maxillary sinus cancer. Their products were the important oncogology indexes, which might be useful to determine illness condition and predict relapse.

Carcinoma, Squamous Cell↗
PubMed2001

[Cloning of promelittin cDNA and its expression in Escherichia coli].

The cDNA encoding promelittin was obtained from the total RNA of bee poison gland by RT-PCR and was cloned to pT7Blu-T vector. The expression vector of promelittin fused with partial sequence of beta-galactosidase was constructed by ligating the fragment inserted to pUC118. Moreover, it was expressed in the strain DH5 alpha of Escherichia coli. The result of DNA sequence analysis demonstrated that the obtained cDNA sequence was same with the published one and the reading frame of fusion gene was correct.

Animals↗
PubMed2001

[Raman spectra of Cu/Zn superoxide dismutase and L-cysteine used as an electron transfer promoter].

In author's laboratory, it has been demonstrated with electrochemical techniques that L-cysteine can be used as an effective electron transfer promoter to accelerate the electron transfer process of Cu/Zn superoxide dismutase on gold electrode. In order to reveal the mechanism of this promotion, confocal microscopic Raman spectroscopic technique is employed here to obtain Raman spectra of solid state SOD and L-cysteine modified gold electrode. Moreover, Raman spectra of L-cysteine modified gold electrode with two different approaches are also obtained. Analysis and discussion for these Raman spectra are reported.

Cysteine↗
PubMed2001

[Study on the interaction between Pd(II) and Rhus vernicifera laccase].

The influence of the mixing time of Pd(II) and Rhus vernicifera laccase on the oxidation of 5,6-dibromo-2,3-dicyanohydroquinone (DDBQH2) catalyzed by laccase has been studied through spectrophotometer at pH 4.5 and (30 +/- 0.1 degree C). The activation of Pd(II) on the laccase activity is gradually converted into inhibition and ultimately inactivation with the extension of the mixing time of Pd(II) and laccase, and the rate of such conversion goes up with the increase of Pd(II) concentration. The influence of Pd(II) on the absorption spectrum of laccase suggests that it is the type I site in laccase with which Pd(II) interacts and Pd(II) may gradually and at last substitute Cu(II) from the site. The substitution may be the cause of decrease and disappearance of laccase activity.

Binding Sites↗
PubMed2001

[The characteristic infrared spectra of N-(2-phenyl-(1,2,3-triazole-formyl)-N'-arylthioueas].

The characteristic infrared spectra of N-(2-phenyl-(1,2,3-triazole-formyl)-N'-aryl)-thioueas have been studied and the changing rules with the change of chemical structure have been discussed. Specially, the effect of the characteristic infrared of long-range radical by different substitute is discussed in detail. Results show that characteristic bands of radical which as far as five radicals away form substitute group are still affected. It is very suggestive meaning for long-range spectra research.

Anti-Infective Agents↗
PubMed2001

[Study on the energy transfer fluorescence quenching among combination of acridine yellow-PAR determination of trace iron].

An energy transfers technique between 4-(2-Pyridylazo) resorcinol(PAR) and acridine yellow is studied, and optimum experimental conditions of energy transfer is done as well. It is found that in the aqueous solution of sodium lauryl sulfate, NH3.H2O-NH4Cl buffer solution at pH = 9.2, the energy transfers from acridine yellow to iron(II)-PAR complexes. So a new method of fluorometric energy transfers determination of trace iron(II) by acridine yellow--PAR was described. The range of determination of iron is 0-10 micrograms.L-1. The detection limit for iron is 0.06 microgram.L-1. The method has been applied to the determination of iron in water sample and hair with satisfactory results.

Aminoacridines↗
PubMed2000

A novel membrane anchor function for the N-terminal amphipathic sequence of the signal-transducing protein IIAGlucose of the Escherichia coli phosphotransferase system.

Enzyme IIA(Glucose) (IIA(Glc)) is a signal-transducing protein in the phosphotransferase system of Escherichia coli. Structural studies of free IIA(Glc) and the HPr-IIA(Glc) complex have shown that IIA(Glc) comprises a globular beta-sheet sandwich core (residues 19-168) and a disordered N-terminal tail (residues 1-18). Although the presence of the N-terminal tail is not required for IIA(Glc) to accept a phosphorus from the histidine phosphocarrier protein HPr, its presence is essential for effective phosphotransfer from IIA(Glc) to the membrane-bound IIBC(Glc). The sequence of the N-terminal tail suggests that it has the potential to form an amphipathic helix. Using CD, we demonstrate that a peptide, corresponding to the N-terminal 18 residues of IIA(Glc), adopts a helical conformation in the presence of either the anionic lipid phosphatidylglycerol or a mixture of anionic E. coli lipids phosphatidylglycerol (25%) and phosphatidylethanolamine (75%). The peptide, however, is in a random coil state in the presence of the zwitterionic lipid phosphatidylcholine, indicating that electrostatic interactions play a role in the binding of the lipid to the peptide. In addition, we show that intact IIA(Glc) also interacts with anionic lipids, resulting in an increase in helicity, which can be directly attributed to the N-terminal segment. From these data we propose that IIA(Glc) comprises two functional domains: a folded domain containing the active site and capable of weakly interacting with the peripheral IIB domain of the membrane protein IIBC(Glc); and the N-terminal tail, which interacts with the negatively charged E. coli membrane, thereby stabilizing the complex of IIA(Glc) with IIBC(Glc). This stabilization is essential for the final step of the phosphoryl transfer cascade in the glucose transport pathway.

Amino Acid Sequence↗
PubMed2000

Homocysteine stimulates nuclear factor kappaB activity and monocyte chemoattractant protein-1 expression in vascular smooth-muscle cells: a possible role for protein kinase C.

Monocyte chemoattractant protein-1 (MCP-1) is a potent chemokine that stimulates the migration of monocytes into the intima of arterial walls. Although many factors that induce MCP-1 expression have been identified, the effect of homocysteine on the expression of MCP-1 in atherogenesis and the underlying mechanisms are not entirely clear. The objective of the present study was to investigate the role of homocysteine in MCP-1 expression in human aorta vascular smooth-muscle cells (VSMCs). After VSMCs were incubated with homocysteine for various time periods, a nuclease protection assay and ELISA were performed. Homocysteine (0.05-0.2 mM) significantly increased the expression of MCP-1 mRNA (up to 2. 7-fold) and protein (up to 3.3-fold) in these cells. The increase in MCP-1 expression was associated with the activation of protein kinase C (PKC) as well as nuclear factor kappaB (NF-kappaB). Further investigation demonstrated that the activation of NF-kappaB was the result of a PKC-mediated reduction in the expression of inhibitory protein (IkappaBalpha) mRNA and protein in homocysteine-treated cells. Oxidative stress might also be involved in the activation of NF-kappaB by homocysteine in VSMCs. In conclusion, the present study has clearly demonstrated that the activation of PKC as well as superoxide production followed by activation of NF-kappaB is responsible for homocysteine-induced MCP-1 expression in VSMCs. These results suggest that homocysteine-stimulated MCP-1 expression via NF-kappaB activation may play an important role in atherogenesis.

Blotting, Western↗