Search PubMed⌕ Search

Biomedical subjects

J Sun

Publications and source records attributed to J Sun.

At least 343 records · Page 19Linked to original sources
PubMed1999

[Study on preventive and therapeutic effect of radix salviae miltiorrhizae on recurrence and metastasis of liver cancer].

OBJECTIVE: To study the inhibitory effect of Radix Salviae Miltiorrhizae (RSM) on adhesive and invasive ability of SMMC-7721 liver cancer cells, and on the metastasis and recurrence on post-hepatectomy liver cancer in nude mice. METHODS: Effect of RSM on SMMC-7721 cell membrane intercellular adhesive molecule-1 (ICAM-1) expression was observed by immunofluorescence flow cytometry; effect on invasive ability and of SMMC-7721 cell and the detachment of which attached to fibronectin (FN) by cell migration experiment; effcet on adhesion of SMMC-7721 cell with FN by MTT method and effect on adhesion between 7721-7721, 7721-lymphocyte and 7721-endothelial cell by cell adhesion experiment. LCI-D20 human liver cancer metastasis model, after hepatectomy, was used to observe the effect of RSM on recurrence and metastasis of liver carcinoma in nude mice. RESULTS: ICAM-1 expression in SMMC-7721 cells incubated with RSM was significantly lower than that in cells did not treated with RSM. RSM could inhibit the invasive ability of SMMC-7721 cell and made the cells already attached to FN exfoliated. It could also inhibit the adhesion of 7721-7721, 7721-lymphocyte and 7721-endothelial cell. And RSM showed preventive and therapeutic effect on intrahepatic and remote metastasis/recurrence of early and late human post-hepatectomy liver cacer in nude mice. CONCLUSION: RSM could inhibit the invasion and adhesion of SMMC-7721 cell and could also prevent and inhibit metastasis and recurrence of human liver cancer after hepatectomy in nude mice.

Animals↗
PubMed1999

[Assay of aluminum content in alum and alum-processed medicinal herbs and its distribution in blood and brain in mice].

OBJECTIVE: To assay the aluminum content in alum and some Chinese medicinal herbs processed with alum, and compare the aluminum distribution of these herbs in blood and brain in mice. METHOD: Aluminum content of the herbs was assayed with spectrophotometry, snd aluminum distribution in blood and brain was assayed with atomic absorption spectrophotometry. RESULTS: Aluminum content in alum was found higher than that in the alum-processed herbs. Aluminum distribution in blood and brain after oral administration at equimolecular doses, equivalent to 5.7 mg/kg of metal Al, was studied in mice, and no significant differences were observed. CONCLUSION: Aluminum distribution in blood and brain in mice is related to the dosages of aluminum administered and has little to do with the kind of herbs used. All these medicinal herbs do not improve the absorption of aluminum in mice.

Alum Compounds↗
PubMed1999

[SPE analysis of 4 rodenticides in whole blood and liver by HPLC].

A solid phase extraction (SPE) method has been developed for the analysis of 4 rodenticides: warfarin, couatetralyl, bromadiolone and brodifacoum, using reverse phase high performance liquid chromatograph (HPLC) as determination system. The recovery is 62.6-90.0% (RSD5.1-7.8%) and 37.5-67.7% (RSD5.4%-12.8%) in whole blood and liver sample respectively. The procedure is simple and stable. And the method was confirmed to be effective in the animal experiment.

Animals↗
PubMed1999

[An experimental study on transplantation of frozen autogenous tooth-mandible compound].

OBJECTIVE: To study the feasibility of reserving the teeth in the transplantation of frozen autogenous mandible. METHODS: Forty adult Wistar rats were used for these operations of transplantation of frozen autogenous tooth-mandible compound (ATMC) and fresh ATMC. Then the healing process after transplantation of frozen ATMC and fresh ATMC was compared by clinical, radiographical, histological and microangiographical observation. RESULTS: There were no significant differences between the healing process of frozen ATMC and that of fresh ATMC, and the fibres of regenerated periodontal membrane which maintained the dental root in normal position could be imbedded in the newly formed cementum. CONCLUSION: It is feasible to transplant the frozen ATMC for reconstructing the mandible and improving its function in clinic.

Alveolar Process↗
PubMed1999

[Color comparison of VITA shade guide and metal ceramic restoration].

OBJECTIVE: To understand color distribution of Vita shade guide and metal ceramic restoration and make Vita shade guide more reasonable in clinical applying. METHODS: The international standard CIE1976L*a*b* color system and Minolta CR-100 spectrocolorimeter were selected to measure and compare the characteristics of the shade guide and metal ceramic restoration. RESULTS: Color differences were noted between the shade guide and ceramic restorations. The value of metal ceramic restoration was brighter than that of VITA shade guide tab. There was different chroma between metal ceramic restoration and Vita shade guide. Metal ceramic restorations were yellower and redder. But no saturation differences were found between ceramic restorations and D2, D3 tabs. CONCLUSION: During clinical color-matching of metal ceramic porcelains, it is suggested that a VITA shape guide tab with lower brightness and paler color than that of adjacent teeth should be selected.

Colorimetry↗
PubMed1999

[Anatomic investigation of facial canal related to middle ear surgery].

OBJECTIVE: To avoid hurting facial nerve in middle ear surgery. METHOD: 20 adult head cadavers with 40 sides tempotal bone were dissected and investigated. RESULT: 1. Prevalence of dehiscent facial nerve canal was 32.5% (13/40), while 2.5% (1/40), 27.5% (11/40), 7.5%(3/40) incidence facial nerve canal were found in the labyrinthine, horizontal, vertical segment respectively. 2. Distance between the vertical portion of facial nerve and posterior semicircular canal was 0.62-5.08(2.48 +/- 0.63) mm. Interspace between the vertical portion of facial nerve and tympanic chorda was 0-4.62 (2.12 +/- 0.76) mm at the level of tympanic ditch, while interspace between the vertical portion of facial nerve and tympanic ditch was 2.96-8.82 (5.86 +/- 1.62) mm. 3. Distance between horizontal portion of facial nerve and lateral semicircular canal was 0-3.02 (1.92 +/- 0.84) mm. Interspace between horizontal portion of facial nerve and stapedial board was 0.92-4.06(2.14 +/- 0.90) mm. CONCLUSION: Familiarity with facial nerve procession should be favorable to decrease facial paralysis with middle ear surgery.

Adult↗
PubMed1999

[Application of derivative technique in the signal processing of gas chromatography].

An application of derivative technique in the signal processing of gas chromatography(GC) is described. TCD's sensitivity of the derivative GC was 270 kV.L/kg, and its susceptibility was 0.3 microgram/L In comparison with the conventional GC, there was a 7-40 fold increase in sensitivity and a 24-40 fold decrease in susceptibility. The noise of the derivative GC was equal to or smaller than the conventional one. The minimum resolution for a pair of substances most difficulty to be separated in conventional GC, which was separated completely in the derivative GC, was 2.8. The linear range of n-butanol was 10(2) and the peak area correlation coefficient of the derivative GC was 0.9991.

1-Butanol↗
PubMed1999

[Breeding of yeast for beer manufacturing by inactivated protoplast fusion].

QSB-XI6, one of fusants, was obtained by PEG-induced fusion between UV-inactivated protoplasts of Saccharomyces cerevisiae LQ16 (Ile-, Datr) and heat-inactivated protoplasts of S. cerevisiae QSB7(Ala-, H2S-). The cell volume, bicmass, genotype and DNA content of the fusant were measured in comparison with of its parents and the results showed that QSB-XI6 was a fusant. The fermentation ability and the flocculent capacity of this fusant were higher than those of its parents. The diacetyl content of the beer produced by the fusant was measured and some other compositions of the beer was also analysed by gas chromatography. The sensory evaluation of the beer was much better and the flavour was distinctive. The results of many production trials in succession showed that all good characteristics of QSB-XI6 were stable.

Cell Fusion↗
PubMed1999

[Surgical reconstruction of laryngeal and tracheal stenosis].

OBJECTIVE: Reconstruction of laryngotracheal stenosis. METHOD: According to the pathologic condition of the larynx and trachea, various surgical procedures were designed for the treatment of laryngotracheal stenosis. These techniques included endoscopic management, laser therapy and laryngotrachoetomy with autogenous tissue and stent. RESULT: Among 36 patients, 32 were decannulated. The success rate was 88.8%. CONCLUSION: In order to improve the curation effects of laryngjotrachal stenosis, the choice of surgical procedure must be individualized to the pathologic condition of larynx and trachea, as well as the experience of the surgeon. Learning previous successful experience is also very important for a good result.

Adolescent↗
PubMed1999

[Changes of Ca(2+)-ATPase in the cochlea of guinea pig during labyrinthine hydrop].

OBJECTIVE: To investigate the localization of Ca(2+)-ATPase (Ca2+ pump) in the cochlea and its change in labyrinthine hydrops. METHODS: The left endolymphatic sac was ablated to induce endolymphatic hydrops in fourteen healthy guinea pigs after the sliver ball electrode was placed on the round window. The Ca(2+)-ATPase was studied by the lead citrate reaction in the control and hydropic ears. The reaction product was lead phosphate particles as an expression of Ca(2+)-ATPase activity under the electron-microscope. RESULTS: The Ca(2+)-ATPase activity was found mainly on the endolymphatic surface of the Reissner's membrane, the stereocilia and cuticular plate of inner and outer hair cells, as well as along the infolding plasma membrane of the strial intermediate cells. The Ca(2+)-ATPase activity was significantly decreased during endolymphatic hydrops in the above-mentioned locations. CONCLUSION: The response thresholds of filtered click were increased and the Ca(2+)-ATPase significantly decreased in the cochlea during labyrinthine hydrops. These results suggest that correlation exists between the CAP threshold and the activity of Ca(2+)-ATPase in the model of labyrinthine hydrops.

Animals↗
PubMed1999

[Determination of trace aluminium by ETV-ICP-AES].

The effect of mixed halogenation agent (polytrifluorochloroethylene (PTFCE)/hexachloroethane (C2Cl6)) on the vaporization of aluminium has been studied in electrothermal vaporization inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES). The mixed halogenation agent hastens the vaporization of Al to the plasma at low temperature compared with individual halogenation agent, and the metallic material can be prevented affectively from forming in the furnace. The detection limit of this method was 0.12 ng with RSD of 3.8% (Al: 0.3 microg x mL(-1), n = 7). The analytical results of real samples were in good agreement with those of pheumatic nebulization (PN)-ICP-AES, and the recoveries were in the range of 94.1%-102.5%.

English Abstract↗
PubMed1999

[Determination of zinc in vegetable oils by FAAS with trace injection method].

A method for the determination of zinc in the soybean, cottonseed and sesame oils by FAAS with trace injection technique was discribed in this paper. The injection volume was 30 microL. The characteristic concentration and the detection limit were 0.098 and 0.00368 microg/g, respectively. The relative standard deviation was 2.6% and the recoveries were in the range of 92.9%-107.8%. The contents of zinc in the samples were 9.67, 1.42 and 1.77 microg/g, respectively.

Limit of Detection↗
PubMed1999

[The absorption spectra of crystal thin film Cs3Cu2I5].

In this paper we measured the absorption spectra of crystal thin film Cs3Cu2I5 at room and liquid nitrogen temperatures, respectively, and calculated the excitonic coefficient of the material. The excitonic coupling energy deltaE(ex)(1) = (0.53 +/- 0.07) eV, excitonic radius a(ex) = 0. 326 nm,and forbidden zone width E(g) = (5.00 +/- 0.07) eV. The spectral analysis shows that the electron and exciton excitations of the Cs3Cu2I5 localize in the CuI subcrystal lattice, and reveals the law that governs the variance of the first excitonic peak position of the serial Cs(x)Cu(1-x) I compounds with their mol-components at low temperature.

English Abstract↗
PubMed1998

Retrograde cerebral perfusion results in flow distribution abnormalities and neuronal damage. A magnetic resonance imaging and histopathological study in pigs.

BACKGROUND: In the past few years, although significant efforts have been made to assess flow distribution during retrograde cerebral perfusion with microspheres, dye, or hydrogen clearance, flow distribution in real time is still undefined. We used MR perfusion imaging to monitor flow distribution in the brain during and after deep hypothermic circulatory arrest (DHCA) with antegrade or retrograde cerebral perfusion (ACP or RCP). METHODS AND RESULTS: Thirteen pigs were divided into 2 groups and exposed to 120 minutes of either RCP (n = 7) or ACP (n = 6) at 15 degrees C, followed by 60 minutes of cardiopulmonary bypass (CPB) at 37 degrees C. During DHCA, the brain was perfused antegradely through the common carotid artery or retrogradely through the superior vena cava at pressures of 60 to 70 mm Hg and 20 to 25 mm Hg in the ACP and RCP groups, respectively. Esophageal temperature was monitored continuously. MR perfusion images were acquired every 30 minutes before, during, and after DHCA. The brain was perfusion-fixed with formaldehyde solution for histopathology at the completion of each experiment. During initial normothermic CPB, MR perfusion imaging showed a nearly uniform distribution of flow in the brain. The same pattern was maintained with a significant increase in regional cerebral blood volume during ACP and reperfusion in the ACP group. RCP provided little or no detectable blood distribution to the brain, resulting in poor reperfusion of many areas of the brain on reflow with CPB at 37 degrees C. The total area suffering poor reperfusion was significantly higher in the RCP group than the ACP group. Histopathology showed no morphological changes in any area of the brain in the ACP group, whereas varying severity of neuronal damage was observed in different regions of the brain in the RCP group. CONCLUSIONS: ACP preserves uniform blood distribution and normal morphology of brain tissue after prolonged DHCA. RCP provides very little blood to the tissue of the brain. A 120-minute period of RCP results in abnormal flow distribution and neuronal damage during reperfusion. The damage resulting from shorter periods of RCP remains to be assessed.

Animals↗
PubMed1998

Antibody repertoire development in fetal and neonatal piglets. I. Four VH genes account for 80 percent of VH usage during 84 days of fetal life.

VDJ rearrangement and VH gene usage during fetal development in 35 outbred piglets was examined by PCR amplification of VDJs; VDJs were subsequently characterized by hybridization with VH-specific gene probes and by sequencing. VDJ rearrangement was first seen in the fetal liver on day 30 of a 114-day gestation. Four VH genes (V(H)A, V(H)B, V(H)C, and V(H)E) accounted for approximately 80% of all VH gene usage regardless of gestational age, choice of piglet, or lymphoid tissue tested; D(H)A and D(H)B were used in >90% of the fetal VDJs examined. Evidence of somatic hypermutation during fetal development was not found. The proportion of the four prominent fetal VH genes did not differ significantly between cDNA and DNA, suggesting the absence of selective B cell differentiation. A comparison of recombination signal sequences, flanking sequences, and framework sequences of these fetal genes with other germline VH genes of swine offered no clue as to their selective usage. N-region additions were prominent on day 40 but not on day 30, suggesting that the onset of terminal deoxynucleotidyltransferase activity occurs after 30 days of fetal development. These collective findings indicate that the preimmune, "natural Ab" repertoire of the fetal piglet is largely restricted to the use of four nonpolymorphic and nonmutated VH genes and two nonmutated DH segments. This suggests that the preimmune repertoire of swine is either highly restricted or almost entirely determined by junctional diversity in complementarity-determining region-3.

Animals↗
PubMed1998

Isolation of PSD-Zip45, a novel Homer/vesl family protein containing leucine zipper motifs, from rat brain.

Using monoclonal antibody against the 45 kDa postsynaptic density protein, we isolated a novel isoform of Homer/vesl. The NH2-terminal region containing a PDZ domain of this protein is identical to that of Homer/vesl, and the COOH-terminal region containing unique leucine zippers shows self-multimerization. We named this protein PSD-Zip45. In addition to specific binding of PSD-Zip45 mediated by a PDZ domain to the metabotropic glutamate receptors 1alpha or 5, the distribution of PSD-Zip45 transcripts is highly consistent with that of metabotropic glutamate receptor transcripts. The PSD-Zip45 is, therefore, the first candidate as receptor anchoring proteins containing leucine zipper motifs in the central nervous system.

Amino Acid Sequence↗
PubMed1998

Oxidation of DNA bases, deoxyribonucleosides and homopolymers by peroxyl radicals.

DNA base oxidation is considered to be a key event associated with disease initiation and progression in humans. Peroxyl radicals (ROO. ) are important oxidants found in cells whose ability to react with the DNA bases has not been characterized extensively. In this paper, the products resulting from ROO. oxidation of the DNA bases are determined by gas chromatography/MS in comparison with authentic standards. ROO. radicals oxidize adenine and guanine to their 8-hydroxy derivatives, which are considered biomarkers of hydroxyl radical (HO.) oxidations in cells. ROO. radicals also oxidize adenine to its hydroxylamine, a previously unidentified product. ROO. radicals oxidize cytosine and thymine to the monohydroxy and dihydroxy derivatives that are formed by oxidative damage in cells. Identical ROO. oxidation profiles are observed for each base when exposed as deoxyribonucleosides, monohomopolymers and base-paired dihomopolymers. These results have significance for the development, utilization and interpretation of DNA base-derived biomarkers of oxidative damage associated with disease initiation and propagation, and support the idea that the mutagenic potential of N-oxidized bases, when generated in cellular DNA, will require careful evaluation. Adenine hydroxylamine is proposed as a specific molecular probe for the activity of ROO. in cellular systems.

Adenine↗