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Biomedical subjects

G Li

Publications and source records attributed to G Li.

At least 469 records · Page 26Linked to original sources
PubMed1999

[Affection of aprotinin on tissue factor pathway inhibitor in peri-operation of cardiac direct vision operation].

Twenty patients underwent cardiac operation with cardiopulmonary bypass(CPB). We collected their blood samples during peri-operation and measured tissue factor pathway inhibitor(TFPI) and active coagulation time(ACT). The results were that TFPI and ACT were significantly increased after heparin injection and during CPB. The changes of TFPI and ACT were similar and pathophysiological; it was evident that heparin stimulated TFPI release and ACT prolonged during cardiac operation with CPB. Aprotinin did not affect the change of TFPI. The results suggest that TFPI has the effect on anticoagulation during CPB.

Adolescent↗
PubMed1999

[Differentially expressed cDNA sequences homologous with known genes in human nasopharyngeal carcinoma].

In order to search the tumor suppressor genes correlated with pathogenesis of human nasopharyngeal carcinoma(NPC), we applied the PCR-based subtractive hybridization technique of representational difference analysis (RDA) to the primary culture cells of normal human nasopharyngeal epithelial and HNE1, a poorly differentiated NPC cell line. Following four successive subtractions of HNE1 complementary DNA from normal human nasopharyngeal epithelial cells complementary DNA, difference products were cloned into pGEM-T easy vector and nucleotide sequences determined. Comparison of cDNA sequences against the databases identified 9 known genes. Known genes included TRIP1(TGF beta receptor interacting protein), TAF, ezrin, MHC II, actinin, Histone H1 zero, Cytokeratin 13, Squalene Synthetase and RNA Synthetase-like. Some of them have an effective suppressive ability on the tumor. In this study, we have demonstrated that cDNA RDA is an effective strategy for systematically isolating differences in gene expression between two related but functionally distinct cells. Our results also indicated that the NPC includes interaction of multigenes and this experiment offers a new route for NPC research.

Carcinoma, Squamous Cell↗
PubMed1999

[Influence factors on correct diagnosis of non-epileptic paroxysmal disorders in childhood].

To investigate the influence factors on correct diagnosis of non-epileptic seizures(NES) in childhood, we analyzed 24 h ambulatory electroencephalography(AEEG) and clinical features of the attacks in 159 children with NES. The results showed that 28% of all patients were identified as NES plus epileptic seizures. Epileptiform EEG discharges were observed in 10% of pure NES children. Abnormal findings on neurodiagnostic evaluation were obtained in 32% of NES plus epileptic seizure groups, in 11% of pure NES groups. Unnecessary anti-epileptic drugs were received in 18% of pure NES children and the kind or doses of the medicines were increased in 50% of NES plus epileptic seizure children who had been mistaken for refractory epilepsy. The influence factors on correct diagnosis of NES are mainly; variability of non-epileptic seizure expression, interictal epileptiform EEG discharges, neurologic abnormal findings, and anti-convulsant abuse.

Adolescent↗
PubMed1999

[Studies on the preparation and characters of anti-AFB1 antibody from the yolk of laying hens].

AFB1O-BSA conjugates were injected into four laying hens (A, B, C and D). The yolk anti-AFB1 antibodies A,C and D produced were obviously increased after 90 days of the first injection, and reached the peak after 135 days, and started dropping after 165 days. The indirect ELISA titer of yolk antibodies A,C and D were 1:8000, 1:6000 and 1:6000 respectively. The specificity of the antibody A was good, but a cross-reaction with AFB2, AFG1, AFG2, with an exception of AFM1, was found. The sensitivities of AFB1, AFB2, AFG1 and AFG2 were 6, 25, 125 and 2495 micrograms/L respectively.

Aflatoxin B1↗
PubMed1999

[Transcriptional activation study of transforming gene Tx-related human nasopharyngeal carcinoma].

Tx gene is the DNA sequence with transforming activity which was cloned from the epithelial cell line (CNE2) of human nasopharyngeal carcinoma(NPC). The goal of this study is to find transcriptional activated site on the Tx 2.8 kb fragment using DNase-I hypersensitivity assay, by which understanding the role of the Tx in carcinogenesis of NPC. The results showed no DNase-I hypersensitivity site on the fragment. It suggests that Tx 2.8 kb fragment homogenous to Ig kappa C might be regulated by the specific mechanism of immunoglobulin gene, rather than that of oncogenes.

Deoxyribonucleases↗
PubMed1999

[Ischemic preconditioning reduces lung ischemia reperfusion injury in vivo rabbits].

Thirty male Japanese white rabbits were randomized into two groups. Fifteen rabbits were treated with ischemic preconditioning(their left lung hilus clamped for 10 min and released for 15 min; Group IP). Fifteen rabbits were not treated with ischemic preconditioning(Group C). Then the left lung hilus of both groups were occlused for 60 min and reperfused for 60 min. The results were that after 60 min of reperfusion, in Group IP, the contents of angiotensin II (Ang II) and artery oxygen tension(PaO2) in blood samples and the contents of superoxide dismutase in lung tissue were significantly higher, while the mean pulmonary artery pressure in blood samples, the wet/dry ratio and malondialdehyde content in lung tissue were significantly lower than those in Group C; Histological findings showed less damage in Group IP. It is suggested that lung ischemic preconditioning can reduce normothermic rabbit lung ischemia-reperfusion injury.

Angiotensin II↗
PubMed1999

[Clinical research of ischemic preconditioning on lung protection].

Twenty patients, who only need to occlude main pulmonary artery underwent pulmonectomy, were randomized into two groups. Ten patients were treated with ischemic preconditioning(IP). Their main pulmonary artery was clamped for 10 minutes and released for 10 minutes(Group IP). Ten patients were not treated with ischemic preconditioning(Group C). The results showed that the content of calcitonin gene related peptide(CGRP) in Group IP was significantly higher than that in Group C after ischemic preconditioning. After lung reperfusion for 30 minutes, the value of superoxide dismutase and pulmonary vein blood oxygen tension in Group IP was significantly higher than that in Group C. It is evident that ischemic preconditioning could reduce normothermic human lung ischemia reperfusion injury. The possible mechanism is that ischemic preconditioning increases the production of endogenous CGRP.

Calcitonin Gene-Related Peptide↗
PubMed1999

[Significance of the changes of plasma endothelin, norepinephrine and atrial natriuretic peptide in treatment of heart failure with beta-blocker].

Thirty patients with chronic heart failure after conventional treatment for two weeks with cardiac diuretic and vasodilator were divided into two groups. There was addition of betaloc into Group A, but Group B kept the original treatment plan for 8 weeks. Group C consisted of 16 normal controls. The results showed that: 1. The level of plasma endothelin(ET), norepinephrine(NE), atrial natriuretic peptide(ANP) in Group A and B were higher than those in Group C. 2. The decreasing degrees of ET, NE, ANP, heart function score and the increasing degrees of CI and LVEF in Group A were more than those in Group B. 3. The change of ET was related to the changes of the others. Therefore, the beta-blocker may be associated with the decrease of the plasma concentration of ET, NE and ANP and improve heart function. It is considered that the degree of change of plasma ET may be the simple and reliable index which evaluate the degree of improving heart function.

Adrenergic beta-Antagonists↗
PubMed1999

[Study on cross-sections at the plane of the aortic arch and its adjacent structures].

The purpose of this study was to describe and explain the normal appearances of aortic arch and its adjacent structures on the transaxial sections and to provide anatomical data for the diagnosis of CT and MR images. Dissections were performed on 1.2 cm interval cross-sections of the thorax of 30 embalmed cadavers. The results showed 20.00 +/- 7.30% of the aortic arch and arch of the azygos vein at the same plane and 40.00 +/- 8.94% of the arch of the azygos vein at the level of concavity of the aortic arch. 80.00 +/- 7.30% of the top of the superior aortic recess extended to the level of the aortic arch from which the branchiocephalic trunk arises. At the level of the aortic arch, 100% of the lymph nodes of superior vena cava were located among the aortic arch, superior vena cava and trachea. At the level of azygos vein, 100% of the lymph nodes of azygos vein and the superior aortic recess were located among the superior vena cava, arch of azygos vein, trachea and concavity of aortic arch. These data suggest that aortic arch and arch of azygos vein are the key structures to identify the superior aortic recess and lymph nodes. They are essential for understanding the related pathologic changes depicted on CT and MR images.

Adult↗
PubMed1999

[Light and electron microscope observations of heart and vascular tissues in animals acutely infected with tubercle bacilli].

The objective of this study was to observe the heart and vascular pathological lesions of some animals acutely infected with H37Rv tubercle bacilli. C57 BL/6N mice and rabbits were used for the establishment of the models. Light sections were stained with HE, Z-N, MCT and BCGS-P. Ultrathin sections were stained with uranyl and lead citrate and examined by electron microscope. The results showed that tubercle bacilli were present in heart and vascular tissues. Myocardial fibre, pericardium and vascular tissues had various degrees of lesions. The lesions of myocardial fibre and pericardium were more serious than that of the vascular tissues. These findings suggest that the toxin of the tubercle bacilli can damage the tissues of the infected animals, and the excessive reproduction can be also a factor detrimental to the infected tissues.

Acute Disease↗
PubMed1999

[Factors affecting Agrobacterium-mediated genetic transformation of Poncirus trifoliata (L.) Raf].

OBJECTIVE: Establishing an effective system for the Agrobacterium-mediated genetic transformation of Poncirus trifoliata, so as to lay a foundation for improving breeds and introducing foreign genes. METHOD: The explants used for the genetic transformation were the epicotyls from Poncirus trifoliata. The Agrobacterium tumefaciens strain was EHA101, containing vector plasmid PGA482GG. The GUS gene and NPT II gene were introduced into the transformation plasmid. RESULTS: 20-day epicotyls were suitable for transformation. 2-day precultivation enhanced shoot regeneration. Shoot regeneration frequency was high when the cocultivation lasted 2-3 days. With the presence of acetosyringone during cocultivation, the efficiency of transformation could be greatly enhanced, and the frequency of shoot regeneration rose as high as 27.5%. After the explants were cocultivated with Agrobacterium, 2-day delayed selection could stimulate shoot regeneration. CONCLUSION: An effective genetic transformation system has been established for Poncirus trifoliata on the basis of factors affecting Agrobacterium-mediated genetic transformation.

Acetophenones↗
PubMed1999

[The enantiomeric separation of aromatic alcohol amino drugs by thin-layer chromatography].

Two chiral aromatic alcohol amino drugs, Labarol and Bataroc, were resolved by thinlayer chromatography (TLC) on the silica gel GF254 plates (2.5 cm x 10 cm), by using the ammonium-D-10-camphorsulfonate (CSA) as chiral ion-pair interaction agent which was added to the mobile phase in the ammonium form. All developments were carried out at lower temperature (2-4 degrees C, in a refrigerator) in small glass jars of 250 mL volume. These two drugs were not resolved at room temperature (15-30 degrees C). Analytical reagent grade methanol and dichloromethane can be directly used as mobile phase without further drying. The chiral separation occured over a range from 40% to 70% (optimum 67%) dichloromethane in the mobile phase volume ratio and 55% to 80% (optimum 60%) dichloromethane in the mobile phase volume ratio. These separation conditions were easily obtained. This method is relatively inexpensive and attractive.

Amino Alcohols↗
PubMed1999

[The biocompatibility of Chinese nitinol alloy intravascular stent].

The aim of this study was to evaluate the biocompatibility of Chinese nitinol alloy intravascular stent. Sixteen Chinese nitinol alloy intravascular stents with 4 mm ID were implanted in the left and right iliac arteries of 8 normal dogs and were observed for one to six months. The results showed that the stents implanted were completely covered by a thin layer of the neointima after one month and the surface of neointima was covered by a monolayer of endothelium-like cells. These suggest that the Chinese nitinol alloy has very good biocompatibility.

Alloys↗
PubMed1999

[Preliminary study of a new concept for left ventricular assistance dynamic aortic valve].

Dynamic aortic valve, a novel design for left ventricular assistance is proposed. An impeller similar to the airscrew is placed in the position of aortic valve. The impeller is held by a pair of bearings in the center of a cylindrical supporting cage which is located in the lumen of the aorta ascendens. The supporting cage is attached to the valve annulus by a sewing ring of textile cuff around the outside of the cage. A rotor is fitted into the cage and connected to the impeller with a common shaft. The cage supports the aortic wall, thus prevents the rotor from founching the wall and allows the rotor to rotate freely. A stator, functioning as that of the electric motor, is located outside the aortic wall. When actuated, the magnetic field generated by the stator would drive the rotor to turning, and the axial flow of blood from ventricular to the aorta would be produced, resulting in the reduction of the ventricular load. We studied this concept in a simulating model. The result suggests that this design be reasonable. Further exploration of this concept is justified.

Heart Valve Prosthesis↗
PubMed1999

[Expression of VP7 from a group A rotavirus G4 field strain in baculovirus system].

The full length of G4 type VP7 cDNA was amplified by reverse transcription and polymerase chain reaction (RT-PCR) from a group A rotavirus field strain CR117 circulated in Beijing. The amplified cDNA was first cloned into pTZ18. Sequence analysis showed 96.9% homology of the deduced amino acid between VP7 of CR117 and ST3. Then the VP7 cDNA of CR117 was subcloned into the transfer vector pBacPAK8 downstream of the polyhedrin promotor. Insect cells were cotransfected with recombinant plasmid pBacPAK8-CR117 and Bsu36I-digested BacPAK6 viral DNA. Recombinant baculovirus containing CR117 VP7 gene was obtained by plaque screen and hybridization identification. Specific VP7 with three different molecular weight was detected by Western blot using hyperimmune serum against Rotavirus strain ST3 (G4 type) when expressed in insect cells.

Animals↗
PubMed1999

[Biological characteristics of the juvenile Paragonimus westermani].

AIM: To observe the biological characteristics of the juvenile of Paragonimus westermani. METHODS: Kunmin strain mice and Wistar rats inoculated orally with 100-150 metacercariae of Paragonimus westermani were autopsied 10-30 days and 80-580 days after infection, respectively. Life-span, survival time in dead hosts or physiological saline at 5 degrees C to 8 degrees C and invasiveness of juveniles to new hosts were detected by host transfer. RESULTS: All the worms recovered from the mice and rats were stunted juveniles. The worm detection rates in the mice and rats were 19.3% and 22.2%-37.5%, respectively. The life-span of the juveniles was rather long, being not limited by the life-span of a host. Host transfer could prolong longevity and preserve invasiveness. The juveniles recovered from dead mice still possess strong vitality and invasiveness. CONCLUSION: The juvenile of P. westermani is an infective stage, having strong vitality and invasiveness.

Animals↗
PubMed1999

[Detection of circulating antigen in serum and cerebrospinal fluid for diagnosis of cerebral cysticercosis].

AIM: To detect circulating antigen(CAg) in serum and cerebrospinal fluid(CSF) from patients with cerebral cysticercosis with specific antiserum by sandwich ELISA. METHODS: Antisera were prepared from rabbits immunized respectively with 3 antigens with molecule weights of 64 kDa, 53 kDa, 32 kDa-30 kDa extracted from Cysticercus cellulosae and purified by SDS-PAGE. RESULTS: When samples from patients were tested with antiserum against 53 kDa antigen, the CAg positive rate was 93.8% in serum and 91.7% in CSF of 32 patients with active cysticercosis, whereas only one positive was found in CSF in 16 patients with inactive cysticercosis. The detection rate of CAg was significantly higher with anti-53 kDa antiserum than with anti-64 kDa and anti-32 kDa-30 kDa antiserum. CONCLUSION: Sandwich-ELISA using antiserum against 53 kDa antigen to detect CAg was found to be a promising assay for diagnosis and evaluation of treatment efficacy of active cerebral cysticercosis in terms of its high sensitivity and specificity.

Animals↗