Search PubMed⌕ Search

Biomedical subjects

L Li

Publications and source records attributed to L Li.

At least 955 records · Page 53Linked to original sources
PubMed1999

[Left ventricular function evaluation after mitral valve replacement with preservation the subvalvular apparatus].

The objective of this study was to evaluate the left ventricular function after mitral valve replacement (MVR) with preservation of all chordae. Fourteen patients with a diagnosis of mitral regurgitation were studied. These patients, 4 males and 10 females, age from 24 to 59 years, who underwent mitral valve replacement, in which all chordae tendineae were preserved. The mean follow-up interval was 6 months. Preoperation and postoperation multigated equilibrium radionuclide angiography was performed by Elscint Helix Apex SPECT. Each patient was injected with 740MBq 99mTc-HSA, rest ejection fraction (global EF) of LV (%), regional ejection fraction (EF) of LV (%), PER/S and PFR/S were measured. Regional EF was calculated by the method of dividing the left ventricle into five segments by radial axis. The results showed that the postoperative EF of the whole left ventricle of the chordae-preserved patients was significantly greater than their preoperative EF (40.0% +/- 17.8%, to 51.6% +/- 18.2%, P < 0.02), and also the regional EF at the lateral wall of the chordae-preserved MVR was significantly greater than the preoperative regional EF (an increase from 51.0% +/- 18.1% to 69.7% +/- 21.2%, P < 0.01). MVR with preservation of all chordae, the patient's left ventricular function remarkably improved.

Adult↗
PubMed1999

[Effect of bushenjiannao 1 decoction on learning and memory functions and anti-fatigue ability in mice].

OBJECTIVE: To observe the anti-dementia effect of Bushenjiannao 1 decoction on mice. METHOD: The learning and memory tests were realized with a water maze on the learning and memory impact of mice induced by scopolamine and cycloheximide. The effect of Bushenjiannao 1 decoction on the independent activity and anti-fatigue ability of mice were also investigated. RESULT: Bushenjiannao 1 decoction used at a medium dose of 15 g crude drug/kg and a higher dose of 45 g crude drug/kg could significantly improve the learning and memory abilities of mice injected with scopolamine. Higher doses could improve these abilities of mice injected with cycloheximide, and also improve the anti-fatigue ability of mice. No significant differences were observed in the independent activity of mice between the groups. CONCLUSION: Bushenjiannao 1 decoction helps improve the learning and memory abilities and enhance the anti-fatigue ability, but has no effect on excitability of the central nervous system.

Animals↗
PubMed1999

[Population study of the CSF1PO, TPOX and TH01 STR polymorphisms in east China].

Allele and genotype frequencies of four short tandem repeat loci were determined in a population sample from east China by using PCR and fluorescence techniques. After denaturing PAGE, 9 alleles were identified for CSF1PO, 8 alleles for TPOX, and 7 alleles for TH01. All loci met Hardy-Weinberg expectations. In addition, the theoretical values of these loci for paternity and forensic casework were evaluated.

Alleles↗
PubMed1999

[Study of relative factors which influenced the embolic level of microspheres in the hamster lingual carcinoma].

OBJECTIVE: To study the relative factors which influence the embolic level of microspheres in the hamster lingual carcinoma. METHODS: Micropicture analysis instrument was used to measure the embolic level of microspheres which were poured through ascending aorta. RESULTS: The optimum pressure of embolization was 30 kPa. The embolic level approached to remote site of the lingual artery as tongue cancer developed. In early invasive cancer period, the embolic level of microspheres was at arteriole level where microspheres block "the total values" which controlled the tumor microcirculation. The optimum embolic result and less offshoot microcirculation were obtained at this time. When in later period, microspheres mainly embolized the meta-arteriole. As the microvessels dilated, the dose of microspheres must be increased to get the best embolic result. CONCLUSION: The experimental data for clinical choice of optimum pouring pressure, optimum opportunity and optimum cases.

Albumins↗
PubMed1999

[Gas chromatographic method for estimating chemical stability of nitroquanidine propellant].

This paper describes a GC analytical method for nitroquanidine propellant instead of the tranditional methylviolet method. Operating conditions were as follows: TDX-01 packed column, 150-200 mesh, 800 mm x 3 mm i.d., at 150-170 degrees C with TCD. Released gases, CO2 and N2O contents in a sealed vessel packed with nitroquanidine were calculated according to the normalization of corrected peak areas of air, CO2 and N2O. Thus, the change in the chemical stability of nitroquanidine during the period of storage and thermal aging could be observed.

English Abstract↗
PubMed1999

[Immunoaffinity purification of specific immunoglobulin from egg yolk].

Immunoaffinity column (Sepharose-4B) was made with bovine serum albumin (BSA) and used to isolate anti-BSA antibody from egg laid by hens which were immunized with BSA. Polyclonal antibody was eluted under different conditions (pH 5.0-2.8) because of its different affinity against antigen. SDS-PAGE and double-immunodiffusion analysis confirmed that antibody isolated from egg yolk was electrophoretically pure and specific. According to the separation aim in this paper, the final elution buffer was 0.1 mol/L glycine-HCl buffer, pH 2.8. The final antibody yield was higher than 90%. As a new development in chromatographic media, POROS has its maximum pressure limit of 21 MPa. It has been widely used because of its high performance, high flow and large capacity. The sugar residue of the antibody was then oxidized and coupled to the hydrazide activated POROS HY. Pure targeted protein (BSA) was obtained through the POROS HY column. The tendency of specific antibody production was investigated during the immunization period. The amount of specific antibody has increased obviously after boost immunization.

Chromatography, Affinity↗
PubMed1999

[Single-pump on-line addition of modifier for supercritical fluid chromatography].

Modified CO2 as mobile phase is usually necessary for packed-column supercritical fluid chromatography. Single syringe pump was applied in this work to add modifier through a parallel connection device, which can maintain constant and stable volume fraction of modifier without any contamination of the pump. Viscosity of the modifiers (here are methanol and acetone) and the length of the CO2 pipe line/modifier pipe line can affect the volume fraction. Volume fractions of methanol and acetone were determined by gas chromatography and ultraviolet spectrometry respectively and their rules of variation were also examined. It shows that the volume fraction of methanol is lower than that of acetone under similar condition. With fixed modifierr line, the longer the CO2 line is, the higher the volume fraction will be. The new device can conveniently alter the nature and ratio of the modifier with quite stable volume fraction. The online addition device can tentatively replace the dual-pump system.

Chromatography, Supercritical Fluid↗
PubMed1999

[The use of inexact reasoning method for differential diagnosis of pulmonary function].

This article expounds the main idea of the evidence theory and hence presents a mathematical model. Based on the above work, we have developped a computer-aided medical differential diagnosis system with Visual Basic. The system can identify restrictive ventilatory impairment, obstructive ventilatory impairment, mixed ventilatory impairment and normal. according to the valuse of patients' related indexed. In a retrospective test of 290 cases we collected, the rate of agreement between the diagnosis made by this system and the physicians was 93.1%.

Algorithms↗
PubMed1999

[Changes of biomechanical properties in goats at different times after ovariectomy].

This paper presents the changes of biomechanical properties in goats at different times after ovariectomy. 14 goats were randomly divided into three groups. These goats were ovariectomized and sacrificed at 180 days (n = 4), 360 days (n = 5) and 540 days (n = 5) after the operation. The right femur, tibia and metatarsus were taken out. The structure mechanical properties of femora were measured with the three-point bending method and those of metatarsus were measured with the compressing method. The material mechanical properties of flexure, compress and tensile strength in the compact bone specimens of femora and tibiae taken from broken ends were also measured. The results showed that the one-year group, compared with the half-year group, had all the bone geometric parameters decreased, but not statistically significant (P > 0.05); the elastic modulus of three-point bending of femora decreased by 23.27% and the others had no significant difference (P > 0.05); all the material parameters of flexurel, compress and tensile strength in compact bone specimens decreased, but only the ultimate strength of tibiae of flexure, compress and tensile strength decreased obviously (P < 0.05). The one and a half year group, compared with the one year group, had the bone density of femora and tibiae decreased, but not statistically significant (P > 0.05). All the bone geometric parameters of tibiae and the thickness of bone of femora increased (P < 0.05). The break load of three-point bending of femora increased (P < 0.05). Probably, it was related to the increase of the body weight in the one and a half year group. The elastic modulus and the ultimate strength decreased, but not statistically significant (P > 0.05). When compact bone specimens were used, the ultimate strength and elastic modulus of femora and tibiae in compress and the elastic module of tibiae in flexure decreased obviously (P < 0.05); and the others had no significant changes (P > 0.05). This study indicated that the degree of osteoporosis in ovariectomized goats increased at half a year, one year, and one and a half year postoperation, and hence suggested that the ovariectomized goat be a pretty useful big animal model of osteoporosis.

Animals↗
PubMed1999

[Determination of glycyrrhetic acid in toothpaste by reversed-phase high performance liquid chromatography (RP-HPLC)].

A method for determining glycyrrhetic acid in toothpaste by RP-HPLC is described. The operating conditions were YWG-C18 column (4.0 mm i.d. x 250 mm, 10 microns) at room temperature, V(methanol):V(0.01 mol/L KH2PO4) = 85:15 (pH 3.0) as mobile phase with flow rate of 1.0 mL/min and UV detection at 254 nm. Glycyrrhetic acid in toothpaste samples were extracted with methanol. The average recoveries of glycyrrhetic acid were 99.61%-101.67%. The relative standard deviations were 1.85%-3.16%. The method is simple, rapid and accurate.

Administration, Topical↗
PubMed1999

[Quantitative backscatter imaging].

Some methods for producing quantitative backscatter images are presented. As a basis, the data reduction method calculates absolute coefficient. The reference phantom method is easier to implement for clinical application. An application method is also presented which separates the contributions of scatter size and scattering strength to backscatter signal and displays Size image and Strength image separately. This method is generally accepted by the medical community. At last, the recent development of ultrasonic backscatter imaging is reviewed.

Algorithms↗
PubMed1999

[Genetic diversity among Chinese peanut rhizobia by rep-PCR analysis].

Repetitive sequences(repetitive extragenic palindromic[REP], and enterobacterial repetitive intergenic consensus [ERIC]) with the polymerase chain reaction(PCR) were used to fingerprint pure DNA extracted from 79 bradyrhizobial strains. These strains included 59 peanut rhizobia [Bradyrhizobium sp. (Arachis)] isolated from root nodules of 24 peanut (Arachis hypogaea L) cultivars from 23 sites in 11 provinces in China, 6 peanut rhizobial strains from other nations, and 14 reference strains of other bradyrhizobia. All the strains were clustered at the level of 11%, 2%, and 11, 24 clusters were obtained at the similarity of 50% with REP-PCR and ERIC-PCR fingerprints, respectively. The results showed that significant genomic diversity exists within the peanut rhizobia from China. Also they suggested that there are different distributions of REP and ERIC in genomic DNA of the peanut rhizobia. The combined results, REP plus ERIC data, were found between the both above. The genomic diversity seems not to correlate with their host and geographic origins. Our results supported this technique is a useful tool for genotypic characterization and identification of rhizobia as well as ecological studies.

Arachis↗
PubMed1999

[Amplification of phytoplasma 16S rDNA from banana bunchy top disease, RFLP and sequence analysis of 16S rDNA fragment].

Extract DNA from banana plants with banana bunchy top disease and amplify the phytoplasma 16S rDNA fragment by nested PCR. The classification of the phytoplasma established on the basis of 16S rDNA restriction patterns was examined by performing a sequence analysis of 16S rDNA fragment. The RFLP pattern, sequence data and phylogenic tree showed that this phytoplasma should belong to Group I(Phytoplasma asteri).

Base Sequence↗
PubMed1999

[The examination of SIgE in perennial allergic rhinitis with mast allergy test system].

OBJECTIVE: To explore the relation between serum specificity immunoglobulin E (SIgE) and skin test (intracutaneous test) as well as nasal provocation in Perennial allergy rhinitis (PAR) by Mast Allergy Test System. METHOD: Serum allergen-specific IgE (SIgE) were examined by Mast Allergy Test System in 57 case of PAR patients. RESULT: The SIgE positive rate of fannae and pteronvssinus are highest (52.6%), the sensitive rate of intracutaneous test is 88.4% and nasal provocation is 88.9%. The SIgE positive rates of cludosporium, penicillum and altemana are 26.3%, 24.6% and 21.0%, respectively. The SIgE positive rates of fannae, cockroach, shrimp, crab, egg and milk is direct proportion with intracutaneous test (P < 0.01). Pteronvssiaus and pigweek mix have no relationship with intracutaneous test (P > 0.05). In addition, the positive rate of ragweed mix SIgE is 22.8%, but there is non of this plant in South China. It is worthy of paying attention in clinic. CONCLUSION: It indicate that Mast Allergy Test System is one of the better examination for PAR allergens.

Adolescent↗
PubMed1999

[Recognition of transient evoked otoacoustic emissions].

OBJECTIVE: To measure the cochlear function more accurately, seeking for a novel method to recognize transient evoked otoacoustic emission (TEOAE) from the recorded signal. METHODS: Time-frequency domain method was used to effectively recognize TEOAE and stimulating artifact by their different short time Fourier transformation (STFT). RESULTS: The STFT of stimulating artifact features decayed rapidly in the air by exponential rule. The frequency distribution of TEOAE was similar to that of the stimulating signal, but the latency and shifting of TEOAE showed a complicated patern. The STFTs of stimulating artifact and TEOAE varied significantly. CONCLUSION: STFT recognition method can separate TEOAE and stimulating artifact effectively so as to improve the accuracy of TEOAE recognition.

Adolescent↗
PubMed1999

[Effects of cyclosporin A combined with T4 on collagen IV production, coll alpha 1 (IV) mRNA and TGF beta 1 mRNA expression in cultured human mesangial cells].

OBJECTIVE: To investigate the effects of single cyclosporin A (CsA), tripcholorlide (T4) or both on renal fibrosis. METHODS: Collagen IV concentrations in the supernatants of human mesangial cells (HMCs) in culture were measured by ELISA. Collagen type IV alpha 1 mRNA (Coll alpha 1 IV mRNA) and transforming growth factor beta 1 (TGF beta 1) mRNA expression were tested by RT-PCR. RESULTS: CsA regulated HMC collagen IV production biphysically, i.e., 1.0 microgram/ml CsA increased collagen synthesis while 0.01-0.1 microgram/ml CsA decreased its formation. T4 enhanced collagen IV production in a dose dependent manner. Combination of the two drugs in lower doses could reach the same degree of immunosuppression as a higher dose of CsA did but with less fibrogenesis. Both CsA and T4 up-regulated HMC Coll alpha 1 (IV) mRNA and TGF beta 1 mRNA expression. The degree of Coll alpha 1 (IV) mRNA expression in different groups were in accordance with that of TGF beta 1 mRNA. CONCLUSIONS: Both CsA and T4 regulate extracellular matrix formation which may be mediated by TGF beta 1. Combination of the two drugs in lower dose results in less fibrosis than a higher dose of CsA.

Cells, Cultured↗