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Biomedical subjects

S Li

Publications and source records attributed to S Li.

At least 1,117 records · Page 62Linked to original sources
PubMed1997

[The effect of combining intra-aortic balloon pumping with tianma injection on myocardial ischemic-reperfusional injury in goats].

The objective of this study was to explore the effect of combined Intra-Aortic Balloon Pumping (I-ABP) and Tianma Injection on necrotic area in goat myocardial ischemic-reperfusional models which were established by two hours ischemia and a follow-up reperfusion. The results showed that the combined effect of IABP and Tianma Injection was more significant than that of IABP or Tianma separately. It is suggested that IABP and Tianma Injection have synergetic effect on the limitation of necrotic area, which possibly results from their mechanisms for decreasing the size of infarct.

Animals↗
PubMed1997

Comparative study of hyperacuity and retinometer tests for the evaluation of vision in patients with advanced cataract.

OBJECTIVE: To investigates the clinical application value of hyperacuity test for evaluating vision through dense cataracts. METHODS: Ten normal subjects (20 years) were tested both with Bailey-Lovie type chart and three points vernier acuity test (one of the hyperacuity test); and retinometer test were performed preoperatively and postoperatively in 30 patients (31 eyes) with senile cataract. These patients' lens opacity was classified with LOCS III system. RESULTS: The correlation of vernier acuity and visual acuity of normal subjects is significant. The result of difference compression of pre-surgical and post-surgical vernier acuity of 30 cataract patients is not significant. The correlation of retinometer findings with post-surgical visual acuity shows not statistically significant. Our result shows that there is good correlation between vernier acuity and post-surgical visual acuity. CONCLUSION: It appears that hyperacuity is a good test for foveal function behind dense cataract and other ocular opacities.

Adult↗
PubMed1997

[Study of antiproliferative effect of gamma-interferon and heparin on rabbit lens epithelial cell (RLEC) cultured in vitro].

PURPOSE: To study the antiproliferative effect of gamma-interferon and heparin on rabbit lens epithelial cell(RLEC). METHODS: First passage RLEC was obtained from healthy New zealand white rabbits. Third passage cells were incubated with gamma-interferon with concentration from 0.1 u/ml to 10,000 u/ml and heparin with concentration from 100-5,000 u/ml for 48 hours. The Mosmann's MTT colorimeltric assay was used to quantitate the RLEC proliferative activation. RESULTS: In lower concentration groups (0.1-100 u/ml), gamma-interferon had no antiproliferative effect on RLEC, while in higher concentration groups (1,000 u/ml-10,000 u/ml) it exhibited some antiproliferative effect on RLEC, the rate of inhibition were 27% and 38%, respectively. Heparin of all experimental groups had antiproliferative effect on RLEC. CONCLUSION: gamma-interferon and heparin with certain concentration can inhibit proliferation of RLEC directly.

Animals↗
PubMed1997

[Study of the antioxidative effect of tea polyphenol and allitridi on cultured rat lens in vitro].

PURPOSE: To investigate the oxidative modification of lens proteins in the presence of H2O2 in vitro and the protective effect of tea polyphenol(TP) and allitridi. METHODS: Rat lenses were cultured in DMEM medium containing H2O2(1mM) at 37 degrees C in CO2 incubator. Iron and copper salts were added to the medium. At 24 or 48 hours, photographs were recorded the changes in transparency of rat lens and lens proteins were analysed by SDS-PAGE and IEF. TP and allitridi were added to the medium with lens in order to test the antioxidant effects. RESULTS: Lens opacities occurred at the equatorial region by 24 hours, progressing to totally opaque by 48 hours. SDS-PAGE revealed new bands higher than 43KD were found. In addition the 30KD band disappeared in medium containing copper salt. With addition of TP or allitridi to the culture system, all lens remained transparent. CONCLUSION: Exposure rat lens to H2O2 with iron or copper salt resulted in opacification of lens with crosslinking of crystallins and degradation of lens polypeptides. Addition of TP or allitridi prevented the lens from oxidative stress.

Allyl Compounds↗
PubMed1997

[Cost-effectiveness analysis of the screening strategies for primary angle closure glaucoma].

PURPOSE: To evaluate varlous primary angle clouse glaucoma(PACG)screening strategies by cost effectiveness analysis for choosing the best screening strategy. METHODS: We designed a model of the process of PACG screening, diagnosis, treatment, and estimated variable parameters of this model through literatures reviewed and the results of our study. Then four screening strategiers which are oblique flashlight test, measurement of axial anterior chamber depth (AACD), examination of peripheral anterior chamber depth (PACD), and combination of oblique flashlight test with examination of PACD in series were calculated by computer to obtain the costs for various screening strategies and the quality ajusted life years (QALYs) saved. We performed sensitivity analysis to determine how the variation in the parameter assumptions would affect the calculated cost effectiveness of the various screening strategies. Based on the principle of cost effectiveness, the screening strategy of more cost effective would be chosen. RESULTS: The results showed that no matter what age group, the screening strategy of oblique flashlight test and measuring PACD combined in series is the lowest cost per QALY gained than other strategies. This screening strategy is optimum, next is oblique flashlight test Screening method. We found that screening strategies not only gains QALY, but also is cost saving as well in the range 40-< 70 years old. sensitivity analysis result showed that optimum strategy is still the combined serial strategy, in addition to the capable closure angle ratio of a population with a 10% up and down, the oblique flashlight test became an optimum strategy and the combined serial method became next in > or = 70 years old group. CONCLUSION: The results showed that the oblique flashlight test and measurement of PACD combined in series is an optimum screening strategy. This research suggests that using adequate screening strategy should not only increase the QALYs, but also save the cost for the government and the patients themselves.

Anterior Chamber↗
PubMed1997

[Cultivated technique of high yield for Polygonatum officinale].

By studying cultivated materials, hided crops, cultivated way, applied fertilizer about the cultivation of Polygonatum officinale, put forward following the methods of cultivation of P. officinale. Choose rhizome segments with top buds as plant materials, adopt level rectangular pieces of land in a field width 100 cm, cultivate late-maturing corn as hiding shady, adopt density of 1.5-2.0 ten thousand plants/mu, apply N and P fertilizers in the growth.

Fertilizers↗
PubMed1997

[Transduction of antisense RNA of MHC-II gene into CD3+ cord blood stem/progenitor cells inhibits the expression of HLA-DR antigen].

OBJECTIVE: To explore whether the antisense RNA of HLA-DR gene could modulate the expression of the gene and reduce the immunogenicity of cord blood (CB) cells. METHODS: A retroviral vector encoding antisense RNA of HLA-DR gene was constructed and transducted into packaging cell line PA317 by lipofectin. CD34+ hematopoietic stem cells/progenitors were sorted and enriched by MACS. RESULTS: A high titer (1 x 1095) cfu/ml) helper-free,virus producing cell PA317 was obtained. The vector was identified by blot hybridization and mapping of restriction points. The CD3+ CB cells were infected by the supernatant of the viral cultures. The G418-resistant clone was demonstrated to express the antisense RNA of HLA-DR gene by RT-PCR technique. The expression rate of HLA-DR antigen on CB cells was 28%, which was apparently lower than that of the control (45%) with an inhibition rate of 38.25%. CONCLUSION: The introduction of antisense RNA of HLA-DR gene into CB hematopoietic stem cells can successfully decrease the expression of HLA-DR antigen. These studies provide evidences for the prevention and treatment of GVHR in clinical CB transplantation.

Animals↗
PubMed1997

[The analysis of fatty acid composition in eyes of mouse].

Fatty acids are one class of the chemical components of eyeballs, especially in the histological structure of retina. They are also the energy source for the maintenance of the normal physiology function. This paper describes the gas chromatographic analysis of fatty acid composition of mouse eyeballs for the first time. The fatty acids in mouse eyeballs were extracted by a mixture of chloroform-methanol-hydrochloric acid followed by esterification with methanol-potassium hydroxide method. The separation was performed on a 25 m x 0.25 mm PEG-20M fused silica capillary column. The qualitative and quantitative analysis of 12 main fatty acids has been accomplished. The results indicate that the normal eyeballs of mouse contain high level of saturated fatty acids which were 52.8% of the whole fatty acids. The content of the mono-unsaturated fatty acids is limited, but the poly-unsaturated fatty acids are the major constituents and account for 18.2% of the whole fatty acids. The ratio of saturated to unsaturated fatty acids is 0.6.

Animals↗
PubMed1997

[A gas chromatographic study on the characters of adsorbents in the enrichment of organic compounds from air samples].

A gas chromatographic method for the measurement of enriching characters of adsorbents used in preconcentration of organic compounds from air samples was studied. The character parameters suggested in this study include adsorption parameters (breakthrough volume or maximum sample volume) and desorption ones (minimum flashing volume and the lowest desorption temperature). The parameters of some low-molecular-mass compounds such as alcohols, saturated hydrocarbons, aromatics, esters and halohydrocarbons on GDX-301 were measured by using elution GC method. The maximum sample volumes of all the 20 compounds (with exception of methanol) got from these experiments are not less than 0.8 L at 35 degrees C for sampling tube (filled with 2 g GDX-301) and 0.3 L at 0 degrees C for focus tube (with 0.14 g GDX-301). The corresponding minimum flashing volumes of less than 177 mL and 13 mL respectively are needed to complete desorption at 180 degrees C, and the lowest desorption temperatures of not over 180 degrees C and 157 degrees C at flashing volume of 180 mL and 30 mL are lower than the maximum allowable operating temperature (250 degrees C) of GDX-301. The results showed that GDX-301 is a good adsorbent for enrichment of the organic compounds mentioned above. The following operating conditions are recommended: using the above sampling tube and focus tube, actual sample volume < or = 0.8 L, adsorption temperature < or = 35 degrees C and focus temperature 0 degrees C, desorption for 6 min from sampling tube and 1 min from focus tube at 180 degrees C with flashing rate 30 mL/min. Good correlations between the parameters and boiling point of the investigated compounds were found. It can be used to estimate the parameters of other organic compounds not measured in this study.

Adsorption↗
PubMed1997

[Studies on determination of p-aminophenol and its related compounds prepared with catalytic hydrogenation by reversed-phase high performance liquid chromatography].

Catalytic hydrogenation of nitrobenzene with supported palladium catalyst is a new method to produce p-aminophenol. p-Aminophenol, aniline and 4,4'-diaminodiphenyl ether obtained from this method were determined by reversed phase high performance liquid chromatography. The factors, e.g., concentration of methanol, pH and ionic strength which could affect separation efficiency were studied. UV spectra of p-aminophenol, aniline and 4,4'-diaminodiphenyl ether were recorded. Good separation was performed by using a 100 mm x 4.6 mm column with 5 microm Hypersil ODS, a mixture of 60% aqueous 8.0 mmol/L KH2PO4 buffered to 6.5 with 4.0 mmol/L Na2HPO4 and 40% methanol as mobile phase at a flow rate of 1.0 mL/min, and UV spectrophotometric detector at 232 nm wavelength. The calibration curves of p-aminophenol, aniline and 4,4'-diaminodiphenyl ether have good linearity over concentration range of 5-250, 5-150 and 0.2-120 mg/L, respectively. Minimum detectable limits at a signal-to-noise ratio of 2 were 0.1, 0.6 and 0.6 ng. This method has been applied to analysis of the reaction products of ultrasonic catalytic hydrogenation and industrial samples with good results and reproducibility.

Aminophenols↗
PubMed1997

[Syntheses and spectra of Mn(III)-chlorophyll-a and Mn(II)-chlorophyll-a].

Manganese(III)-chlorophyll-a [Mn(III)-Chl-a] was synthesized by the reaction of pheophytin-a and manganese(II) acetate and separated by HPCL. Manganese(II)-chlorophyll-a [Mn(II)-Chl-a] was acquired from Mn(III)-chl-a reduced by sodium hydrosulfite (Na2S2O4) in acetone-water. Because Mn(II)-Chl-a is oxidized very easily in the air, Mn (II)-Chl-a was kept under a nitrogen atmosphere and reductant during the spectroscopic measurements. Elemental analysis, absorption and FT-IR spectra proved that the metal Mn-substituted Mg of chlorophyll-a has been successfully performed and possible structure of new complexes was also given. Their formulae are [Mn(II) (chlorophyll-a)] and [Mn(III) (chlorphyll-a) (CH3COO)-(H2O)] respectively.

Chlorophyll↗
PubMed1997

[An epidemiological study of HGV infection in an epidemic area of HCV infection in Japan].

We examined the prevalence on HGV infection in a hepatitis C epidemic area where 27.8% of inhabitants 40 years or over were anti-HCV positive. Of the 200 HCV RNA positive inhabitants 17(8.5%) were HGV RNA positive, although one of the 100 anti-HCV negative inhabitants in the same epidemic area, showed HGV RNA positive (1.0%). It might suggest that HGV infections in this HCV infection epidemic area have occurred in relation to HCV infection. The rate of abnormal transaminase in inhabitants HGV RNA and HCV RNA both positive was not different from that in inhabitants HGV RNA negative, but HCV RNA positive. This indicates that a further study is needed about the relationship between liver damage and HGV infection.

Biomarkers↗
PubMed1997

Radiographic results from the Minocycline in Rheumatoid Arthritis (MIRA) Trial.

OBJECTIVE: To assess radiographically determined disease progression in patients in the Minocycline in Rheumatoid Arthritis (MIRA) Trial. METHODS: A double blind, randomized, multicenter, 48 week trial of oral minocycline (200 mg/day) or placebo in 6 clinical centers in the United States. Patients include 219 adults with active RA previously receiving limited treatment with disease modifying drugs. Posteroanterior films of the hands from baseline and final visits, blinded for sequence, were read for erosions and joint space narrowing by trained observers. Outcomes included rate of disease progression (change/month) and percentage of patients with progression from baseline, newly involved joints, and newly erosive disease. RESULTS: Using intent-to-treat analyses, progression rates for erosions (0.11 +/- 0.42 minocycline, 0.17 +/- 0.41 placebo; p = 0.47) and joint space narrowing (0.16 +/- 0.55 minocycline and 0.23 +/- 0.71 placebo; p = 0.14) were similar. (Power 43% to detect a 50% difference.) Newly erosive joints occurred more frequently in the placebo group (44 vs 32%; p = 0.08), not a statistically significant difference. CONCLUSION: Radiographic measurement of disease progression using 4 measures failed to show a significant difference between minocycline and placebo treatment, although for all methods there was a trend toward treatment benefit, consistent with reported clinical results. A one year trial duration, high measurement variability, and slow rate of radiographic progression in this cohort may explain the low power to detect a treatment effect. The measurement that denoted "newly involved" joints was most sensitive in detecting change. In future trials longer term assessment (minimum 2 years) of radiographic changes and further comparison of measures of disease progression are warranted.

Adult↗
PubMed1997

Expression in Escherichia coli and purification of human thrombopoietin.

Human thrombopoietin (TPO) has been successfully overexpressed in Escherichia coli, with an expression level of about 12% of total cellular protein. The full-length TPO gene was subcloned into the prokaryotic expression vector pKK233-2 under the control of the inducible tac promoter. The recombinant protein was produced mainly in the form of inclusion body. By efficient renaturation and one-step purification, the recombinant protein was purified to homogeneity. The specific activity and yield of recombinant TPO can reach 2 x 10(4) units/mg and 2 mg/g of wet E. coli cells respectively.

Chromatography, Liquid↗
PubMed1997

Quantification of IL-2 and IL-2 receptor mRNA in peripheral blood mononuclear cells by the RT-PCR based SHARP Signal system.

Nuclear transcription assays have shown that increases in interleukin 2 (IL-2) and its receptor (IL-2R) mRNA are reflected at the level of transcription. However, the quantification of transient and low-level expression of IL-2/IL-2R mRNAs in normal resting peripheral blood mononuclear cells (PBMC) requires a sensitive and reliable assay. We have established a quantitative reverse-transcriptase-polymerase chain reaction (RT-PCR) assay to measure IL-2/IL-2R transcripts by modifying the commercially-available SHARP Signal system to include IL-2/IL-2R RNA probes that were constructed by in vitro transcription of phagemid clones. To evaluate this modified SHARP Signal system and to demonstrate its clinical utility, the expression levels of IL-2 and IL-2R were assessed for 40 healthy normal donors. The mean +/- SEM levels of transcripts in normal PBMC expressed in zeptomol per micrograms total RNA for IL-2, IL-2R alpha and IL-2R beta were 2.6 +/- 0.5, 23.3 +/- 2.2 and 157.2 +/- 32.2 respectively. Compared with the conventional RT-PCR and gel-electrophoresis-based detection method, the SHARP Signal system is fast, not labor-intensive and inexpensive, and can be readily adapted for the measurement of other cytokines or cytokine receptor gene expressions in a clinical diagnostic laboratory environment without extensive experience in molecular techniques.

Adult↗
PubMed1997

Extractive L-lactic acid fermentation with immobilized Rhizopus oryzae in a three-phase fluidized bed.

The Rhizopus oryzae was immobilized by the calcium alginate entrapment method. A three-phase fluidized-bed bioreactor was designed to perform the immobilized-cell L-lactic acid fermentation. A solvent extraction column was coupled with the bioreactor to remove L-lactic acid from the fermentation broth. The TRPO was selected as solvent and sulfonated kerosene as diluent. The results indicated that the pH value in the broth was regulated above pH 3.5 and the fermentation rate was as high as 11 g L-lactic acid per hour per liter of beads. A mathematical model was proposed to describe the concentration of L-lactic acid in the extractive fermentation.

Fermentation↗