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Biomedical subjects

Z Chen

Publications and source records attributed to Z Chen.

At least 883 records · Page 49Linked to original sources
PubMed1998

[Electrophoresis of proteins in gingival crevicular fluid of patients with adult periodontitis before and after treatment].

OBJECTIVE: To analyze the overall gingival crevicular fluid (GCF) protein profiles from adult periodontitis (AP) both before and one month after conventional periodontal treatment in expectation to find reliable specific protein markers in GCF for healthy and disease. METHODS: GCF samples were collected using filter paper strips from 56 sites of 12 AP patients. The proteins of GCF were examined via sodium dodecyle sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and analyzed by the Image Master Electrophoresis Evaluation System. RESULTS: After periodontal treatment, the mean number of protein bands and the abundance and percentage of non-serum derived low molecular weight proteins (12,000, 10,000) decreased significantly (P < 0.001 and < 0.05 respectively). The percentage of non-serum derived 38,000 protein increased and correlated negatively with pocket depth and the volume of GCF before treatment. CONCLUSION: 1. the elevation of the 12,000 and 10,000 proteins are associated with the periodontal inflammation; 2. the elevation of 38,000 protein is associated with recovery.

Adult↗
PubMed1998

[Histomorphologic study of the bone repair materials by using the cold plasma technique].

OBJECTIVE: The purpose of this article is to improve the biological activity of the implant pretreated by use of cold plasma technic and to investigate the biological effects after implanted into bone. METHODS: First, HA granular was set in the electric field with high voltage and vacuum, then the gaseous mixture of ammonia, hydrogen and nitrogen was led to. By coupled capacity glow discharge, the plasma was produced and the pretreatment was completed. In this way, the surface of HA granular may obtain active amino structure. Sequently, the material was implanted into bone of the animal and the dynamic changes at the material/bone interface were histologically observed. RESULTS: The active group was definitely formed on the surface of the material after pretreatment and there were no adverse effects on the morphology and properties of the base material. Furthermore, the early formation of new bone at the interface of the material/bone was detected, and obvious effects on facilitating bone growth and osseointegration were obtained. CONCLUSION: The findings indicated that cold plasma pretreatment technic was an effective method to improve the biological activity of implant material.

Animals↗
PubMed1998

[The orthogonal design study on tumor-inhibition and cancer-block role of Chinese medicinal 1023 co].

OBJECTIVE: To study the effect of Chinese herb medicine on the inhibition of tumor formation and block of malignant transformation. METHODS: The Chinese medicine 1023 co. was given by intubation feeding started simultaneously with the painting of 0.5% DMBA on the hamster's cheek mucosa. RESULTS: The tumor formation in 1023 co. group was delayed for 12 days comparing with the control group and the incidence of dysplasia and cancer in 1023 co. group was lower significantly than that of the control group (P < 0.01). CONCLUSION: The 1023 co. is effective in inhibiting tumor formation and blocking cancerous transformation. By orthogonal design we find the proper prescription is A2 B2 C2 D1.

Animals↗
PubMed1998

[Electrophoretic analysis of protein composition in gingival crevicular fluid].

OBJECTIVE: To seek the protein composition related to periodontal diseases. METHODS: 86 gingival crevicular fluid (GCF) samples were collected by rinsing the sulgingival sulci from subjects with healthy gingiva (20), gingivitis (24) and periodontitis (42). The protein composition were examined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) on a Phast System. The gels were scanned and analyzed using Phast Image with computer. RESULTS: In inflammatory condition, the serum derived proteins with MW 82,000, 77,000, 17,000 occurred more frequently than in healthy gingiva, and the occurrence and abundance of non-serum derived proteins with MW 41,000, 21,000, 12,000 were also increased in inflammatory condition compared with healthy gingiva. CONCLUSION: The high levels of proteins with MW 82,000, 41,000, 21,000, 12,000 are close related to the periodontal inflammatory status.

Adult↗
PubMed1998

[The role of nitric oxide in hyperdynamic circulation in portal hypertensive rats].

OBJECTIVE: To evaluate the role of nitric oxide (NO) in hyper-hemodynamics in portal hypertension, we investigated the effects of nitric oxide synthase inhibitor L-NMMA with or without L-arginine, the substrate for enzyme NO synthase on the systemic and splanchnic hemodynamics in portal hypertensive rats. METHOD: Ninety-seven male Sprague-Dawley rats were divided into four groups: intrahepatic portal hypertension (IHPH, n = 23) by injection of CCl4, prehepatic portal hypertension (PHPH, n = 26) by stenosis of the portal vein, end-to-side portacaval shunt (PCS, n = 23), and sham-operated controls (SO, n = 25). Animals of each group were divided into three subgroups: systemic administration of L-NMMA (50 mg/kg BW, 1 ml), L-NMMA (50 mg/kg BW, 0.5 ml) plus L-arginine (30 mg/kg BW, 0.5 ml), and normal saline solution (1 ml). The radioactive microsphere method was used for hemodynamic study. RESULT: There was the characteristic of hyperdynamic circulatory state including increased cardiac output and splanchnic blood flow, decreased mean arterial blood pressure, total peripheral vascular resistance and splanchnic vascular resistance in IHPH, PHPH and PCS rats. The hyperdynamic circulatory state in IHPH, PHPH and PCS rats could be effectively reversed by L-NMMA to the resting values of hemodynamics in SO rats, but not the levels after administration of L-NMMA in SO rats, indicating that there is excessive production of NO in portal hypertensive and PCS rats. Administration of L-arginine counterbalanced the effects of L-NMMA on hyperdynamic circulatory state in portal hypertensive and PCS rats. CONCLUSION: NO is an important mediator of hyperdynamic circulation in portal hypertension.

Animals↗
PubMed1998

[Azone-induced changes on corneal endothelium in rabbits].

OBJECTIVE: To investigate ocular toxic effect of azone at low concentrations in rabbits to determine whether this penetration enhancer has any value for ocular use. METHODS: 0.3%, 0.6%, 0.9% concentrations of azone in an ocular emulsion vehicle were studied. Rabbits in three experimental groups received topical 30 microl of 0.3%, 0.6%, 0.9% azone respectively three times daily for 4 weeks. Rabbits in control group 1 received 30 microl of vehicle without azone as negative control and rabbits in control group 2 received nothing as normal control. Clinical and histopathological examinations of rabbit cornea endothelial cells were made by slit-lamp biomicroscopy, light microscopy and scanning electron microscopy. RESULTS: No clinical and histopathological evidence of ocular toxicity occurred in all treated and control eyes. The concentration of azone used in this study was 3-9 times higher than that (at 0.1%) at which corneal penetration of hydrophilic compounds can be enhanced enormously. CONCLUSION: Azone has value for incorporation into ocular formulations to increase therapeutic action of many hydrophilic drugs.

Animals↗
PubMed1998

[The determination of neuron-specific enolase of serum in the diagnosis and supervision of retinoblastoma].

OBJECTIVE: To investigate the value of determining quantity of neuron-specific enolase (NSE) in the diagnosis and supervision in patients with retinoblastoma (Rb). METHOD: We used rapid electrophoretic and the fluorometer method in the 35 serum specimens from 35 patients with Rb during surgery, after enucleation, respectively, at 3, 6, 12, >or= 18 months and 31 serum specimens from 31 control cases to determine the quantity of NSE and enolase isoenzymes. RESULTS: There were 207 +/- 65.9 u/L of all isoenzymes and 98.4 +/- 40.3 u/L of NSE from 35 patients with Rb. In comparison with the levels of control cases (respectively, 140.7 +/- 46.0 U//L of all isoenzymes, 41 +/- 10.9 u/L of NSE), both serum levels in patients with Rb increased obviously, the difference being significant. At 6, 12, and >or= 18 months after surgery, the determinations of all isoenzymes and NSE from 35 patients with Rb decreased step by step, the difference being significant in comparison with the values before the surgery. After surgery >or= 18 months, the levels of NSE and all enolase decreased to that of NSE and all enolase from control cases. CONCLUSION: The determination of enolase level, especially NSE of serum, is valuable for the diagnosis of patients with Rb.

Child↗
PubMed1998

[Intraocular penetration of topical lomefloxacin in rabbit's eyes].

OBJECTIVE: To measure the rabbit ocular tissue concentration of lomefloxacin (LMLX) after its topical application. METHODS: Fifteen rabbits (30 eyes) for the experiment (12 white rabbits and 3 pigmented rabbits) were divided into 5 groups. In the 1st group, 0.3% LMLX eyedrops were instilled once (1 drop each) in the 3 white rabbit's eyes. In the 2nd group, 0.3% LMLX eyedrops were instilled for 6 times (1 drop once) with an interval of 5 minutes in the 3 white rabbit's eyes. In the 3rd group, 0.3% LMLX eyedrops were instilled once (1drop each) in the 3 white rabbit's eyes after removal of corneal epithelium. In the 4th group, 0.3% LMLX eyedrops were instilled once (1 drop each) in the 3 pigmented rabbit's eyes. In the 5th group, LMLX 0.5 mg was subconjunctivally injected in the 3 white rabbit's eyes. After the administration for 30 minutes, aqueous humor was collected and the eyeball was enucleated. All measurements were performed by high-pressure liquid chromatography (HPLC). RESULTS: In the 1st group, the mean levels of drug were 8.75 +/- 3.09 microg/g in cornea, 0.21 +/- 0.1 microg/ml in aqueous humor, and 1.49 +/- 0.39 microg/g in iris, respectively. The ocular tissue concentrations of the other groups were significantly higher than that of the 1st group. The pigmented tissue of pigmented rabbit's eyes had relatively high concentration of LMLX. CONCLUSION: All concentrations of LMLX in rabbit's eyes are above the minimum inhibitory concentration for 90% (MIC(90)) of most bacterial pathogens. LMLX has greater affinity in the pigmented tissue. These results show that LMLX may be an effective antimicrobial agent for prophylactic use in ophthalmic surgery and also for the treatment of intraocular infections due to susceptible organisms.

Animals↗
PubMed1998

[Protective effect of hyperin against cerebral ischemia-reperfusion injury].

The protective effect of hyperin (Hyp) against cerebral ischemia-reperfusion injury was studied. On the cerebral ischemia-reperfusion model in mice, Hyp (50, 100 mg.kg-1, i.p.) was shown to markedly and dose-dependently inhibit the decrease of lactate dehydrogenase (LDH) in cerebrum and improve the learning and memory impairment on the step down test. On the four-vessel occlusion model in rats, Hyp(50 and 100 mg.kg-1, i.p.) significantly reduced the decreases of glutathione peroxidase(GSH-Px), superoxide dismutase(SOD) and LDH activities in the cerebrum. Hyp was also shown to inhibit the increase of nitric oxide (NO) and malondialdehyde (MDA) contents in the cerebrum and promote the recovery of EEG activities. These results suggest that Hyp has protective effect against cerebral ischemia-reperfusion injury via attenuating free radical and NO.

Animals↗
PubMed1998

[Assignment of a novel zinc finger gene ZNF191 to human chromosome 18Q12.1 by human/rodent somatic cell hybrid panel and fluorescent in situ hybridization].

A novel human zinc finger gene, ZNF191, was assigned to chromosome 18 by hybridization of human/rodent hybrid cell panel to a full-length cDNA as a probe. Meanwhile, a human genomic DNA lambda/DASH library was screened using this cDNA probe and several positive clones were obtained. Fluorescence in situ hybridization (FISH) was performed by using one of these positive clones, 16-1, as a probe. Thus, the ZNF191 gene was precisely mapped in 18q12. 1. To date, some hereditary diseases and tumors have been found to be associated with this region by analysis of genetic linkage and loss of heterozygosity. Hence, it suggested that the gene ZNF191 can be taken as a candidate gene responsible for those diseases and tumors.

Chromosome Mapping↗
PubMed1998

[The development of computer-assisted gastric function testing system].

This paper introduces a system consisting of the PC computer, sensing device, the card for electro-gastric signals amplifier and analog-digital converter. By using only one piece of 1.2 M 3" diskette, the system can realize the dialogue between human and the computer to sample, process, store and display the electro-gastric signals, and print the auxiliary analysis and diagnostic results for doctors to refer to. When the computer is more and more popular today, it is one of the convenient, painless and effective method to check up the gastric functional disease.

Adult↗
PubMed1998

[Establishment of a method for detecting transforming growth factor beta 1 mRNA].

AIM: To establish a method to measure the TGF-beta 1 mRNA level for studying the mechanism of fibrogenesis caused by schistosomiasis japonica. METHODS: Reverse-transcription polymerase chain reaction and dot blot analysis were used. A plasmid of TGF-beta 1 was constructed for standardization, and beta-actin was used as control. Eight different concentrations of the plasmid and 11 double-tube of TGF-beta 1 mRNA in the peripheral blood mononuclear cell (PBMC) of different persons were measured. RESULTS: Quantitative results of 8 different dilutions of TGF-beta 1 plasmid had positive with the logarithm of the original concentration. The results of the 11 double-tube were 1.71 +/- 0.90 and 1.54 +/- 0.88. CONCLUSION: The duplicability and stability of the method showed it can be used to analyse the TGF-beta 1 mRNA level of the peripheral blood mononuclear cells.

Humans↗
PubMed1998

[Study on the method of adsorbing albumin for enwrapping human hard tissue substitute biomaterials].

The aim of this study was to cover up the surface of human hard tissue substitute biomaterials with albumin. The cidex cross-link method was adopted to adsorb albumin so as to form a membrane for wrapping hydroxyapatite(HA), bio-glass ceramics(BGC), and hydroxyl poly-calcium sodium phosphate (HP). The results showed that this membrane of protein could enwrap the biomaterials so firmly that urea solution could not wash it off.

Adsorption↗
PubMed1998

[The changes in quantities of elements around cementum-dentin junction in human natural tooth--electron probe microanalysis].

To study the changes of inorganic and organic substance around cementum-dentin junction in the tissues of human natural tooth, the method of electron probe microanalysis was used in this research project. Determinations of weight percentage (wt%) were made for Ca, P and S elements around cementum-dentin junction. The results showed that the changes in quantities of Ca, P and S elements around cementum-dentin junction were not significant(P > 0.1). These suggest that the quantities of inorganic and organic substance have not obviously varied with the anatomic structure of natural tooth.

Adult↗
PubMed1998

[Study on bone-repairing biomaterial ytterbium oxide-hydroxyapatite].

Hydroxyapatite was extensively used to repair osteoshortage recently. To improve its bondibility and X-ray obstructibility, we added ytterbium oxide of different proportions in the synthetic process of hydroxyapatite. Ytterbium oxide is characterized by high activity and X-ray obstructibility. A cheap biomaterial with good biocompatibility and high X-ray obstructibility has been got in this way.

Animals↗
PubMed1998

[Hemorheologic change after strong blood flow disturbance caused by gunshot and its influence on the prognosis of the wounded animals].

Three types of experimental models were used in this study: 1. Both thighs of dogs were wounded by 5.56 mm bullet. 2. Femoral artery and vein were tied at the time of wounding. 3. Shock caused by simply bleeding the dogs' femoral arteries. We observed the characteristics of change hemorheology and analyzed its effects on the wounded dogs. The results showed that strong blood flow disturbances always brought about hemorheologic changes such as rapidly increased blood viscosity and red cell's aggregation index and the simultaneous phenomenon of blood concentration. These may be related to extensive endothelium injury and destruction of a number of blood cells caused by disturbance wave. The above change may give rise to abnormality of microcirculation and disturbance of matter transmission; in that sense, it may provide the physiopathologic basis for the occurrence and development of the complication.

Animals↗