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Biomedical subjects

L Li

Publications and source records attributed to L Li.

At least 739 records · Page 41Linked to original sources
PubMed2000

[Morphological observation on dorsal root ganglion neurons of embryonic chicken in vitro].

The aim of this study was to explore the developmental character of neurons from dorsal root ganglion (DRG) of embryonic chicken in vitro. The DRG neurons of Hamburger stage 35 were cultured and prepared at 0, 1, 2, 3, 4, 5, 7, 14 and 21 days respectively. The number of neuronal survival was counted at each cultured stage (observed area: 2.5 x 10(5) microns 2) and the morphological change of neurons in vitro was observed and compared with that of neurons in vivo. The results showed the counts of neuronal survival were 94 +/- 4, 83 +/- 6, 67 +/- 4, 65 +/- 7, 68 +/- 5, 71 +/- 9, 73 +/- 6, 22 +/- 4, and 0 respectively; the cultured neuronal shape during 48 h incubation was mainly oval or sphere, similar to that of neurons in vivo. However, the shape of some neurons changed into cone or shuttle after three days incubation, while the neuronal shape in vivo did not change. These findings indicate that only some of neurons can survive and grow and the lifetime is limited in vitro, on the other hand, the developmental character of neurons in vitro may be different from that of neurons in vivo.

Animals↗
PubMed2000

[Evaluation on usage of serum troponin-I, CK-MBmass and myoglobin measurements in diagnosing acute myocardial infarction].

The purpose of this study was to search the sensitivity of three indicators in early diagnosis of acute myocardial infarction (AMI) and analyze their window-time duration in serum, along with the decision on experimental golden indicator in later AMI inspection and effect assessment after recovery by testing the concentrations of CTnI, CK-MBmass and Mb in AMI patients' serum. By using corpuscle chemiluminescence, the serum concentrations of CTnI, CK-MBmass and Mb in AMI patients, UA (unstable angina) patients, SM (skeletal muscle) patients and a normal group were assayed and compared. A dynamic analysis was followed in five periods, which separately focused on 3-5, 8-14, 20-24, 72 hours and 7 days after heart aching occurred in AMI patients. The results showed the positive rates of CTnI, CK-MBmass and Mb in AMI patients were 65%, 70% and 70% respectively, and the positive rate of CTnI in UA and SM groups was 0%. The CTnI, CK-MBmass and Mb values in group AMI were significantly higher than those in groups of UA and SM. Separately, the CTnI value in AMI was 84 and 91.63 times (the CTnI values) in UA and SM; the CK-MBmass value in AMI was 8.82 and 4.67 times and the Mb value in AMI was 11.57 and 2.25 times as high as those in UA and SM. Significant difference was observed by the comparison between AMI group and UA, SM groups (P < 0.001). According to the dynamic analysis, CTnI, CK-MBmass and Mb rose significantly at the early stage of AMI onset (3-5 hrs), and then gradually increased with time. The climax occurred in the period of 8-14 hrs and Mb returned to its normal state in 72 hrs. On the 7th day, CTnI still existed in serum, but CK-MBmass approximated to normality. In conclusion, these data demonstrate a relatively high sensitivity of CTnI, CK-MBmass and Mb in early diagnosis of AMI. CTnI is specific to cardiac muscle for its special positive rate. Also, CK-MBmass and Mb are of higher clinical value in diagnosing cardiac muscle damage. CTnI has the longest window-time, which makes it the best special indicator for terminal inspection and recovery decision on AMI.

Adult↗
PubMed2000

[The effect of soft tissue repairing at different times on the union of type III b tibial fracture].

OBJECTIVE: To investigate the effect of soft tissue repairing at different times on the union of type III b tibial fracture. METHODS: From January 1987 to January 1999, seventy-six type III b tibial fractures were divided into 3 groups: early group(0 to 7 days), subacute group(8 to 30 days), late group(more than 30 days) according to the time of soft tissue repairing. The morbidity rates of complications such as infection, nonunion as well as the time to union were compared respectively. RESULTS: Followed up for 10 to 36 months (averaged 24 months), the infection and nonunion rates of early group were lower than that of subacute and late groups(P < 0.01), the average time of fracture union of early group was less than that of subacute and late groups. CONCLUSION: Early soft tissue repairing can decrease the complications and the time to union of Type III b tibial fracture obviously. The time of "early" should be limited in one week and as soon as possible.

Accidents, Traffic↗
PubMed2000

[Hairy root induction and in vitro cultivation of Pueraria lobata willa. ohwi].

OBJECTIVE: To study the hairy root induction and hormone-free in vitro liquid cultivation of Pueraria lobata (Willd) Ohwi. METHOD: Co-cultivation of super-virulent Agrobacterium rhizogenes R1601 with P. lobata leaves in vitro. RESULTS: Hairy roots of rapid growth, high branches and plagiotropism developed vigorously on the surface of leaves, exhibiting rapid growth and resistance to kanamycin in hormone-free medium in vitro. CONCLUSION: A method of hairy root induction with A. rhizogenes as well as a system hairy root liquid cultivation in vitro for P. lobata have been established.

Coculture Techniques↗
PubMed2000

[Effects of the expression of mouse metallothionein-I gene in human HeLa cell line on drug resistance].

Metallothionein-I (MT-I) gene was inserted into EcoRI site by using pSV2-neo plasmid vector. Recombiant plasmid was transfected into HeLa cells by DNA-calcium phosphate precipitation technique. MT-I expression colones were growing in medium including G418. The amount of MT-I expression in transfected cells was found 2.6 times higher than that of non-transfected ones. In order to observe the relationship between the expression of MT-I gene in cells and drug resistance, cells were treated with different concentrations of cisplatin and adriamycin respectively. The results indicated that cisplatin (0.1 mumol/ml) inhibited the growth of both transfected and non-transfected cells. The inhibitory rates were 34% and 82% respectively(P < 0.05). IC50(50% inhibitory concentration for cell growing) was 0.144 mumol/ml and 0.061 mumol/ml and the ratio of them was 2.36: 1 after the treatment of cisplatin 72 h later. The cells were treated with adriamycin 72 h later, the inhibitory rates of transfected and non-transfected cells were 18% and 25% separately. The rates showed no significant difference (P > 0.05). The results indicated that MT was related to drug resistance of tumor cells.

Animals↗
PubMed2000

[Effects of 6 kinds of metal elements on meiotic maturation and in vitro fertilization on mouse oocyte].

To study the effects of Cd, Pb, Ni, Mn, Cr and Al on reproductive toxicity, the meiotic maturation and in vitro fertilization(IVF) of mouse oocytes were studied using in vitro culture and IVF of mouse oocytes. The results showed that except Al(NO3)2, the other groups [CdCl2, Pb(NO3)2, NiCl2, MnSO4 and CrCl3] could significantly reduce the number of superovulation oocyte. All of them could inhibit the meiotic maturation, the rates of IVF and extruding of the first polar body, but there was no impact on the germinal vesicle breakdown (GVBD) in vivo. The results also showed that except Al(NO3)3, other elements could obviously inhibit germinal vesicle breakdown of mouse oocytes. The results suggested that these elements might damage the process of meiotic maturation of oocyte of women at child-bearing age oocyte and reduce the fertility and reproductive capacity and result in sterile.

Animals↗
PubMed2000

[Effect of estrogen on the expression of c-myc protein of bone in mice].

In order to study the mechanism by which estrogen effects on bone, the effect of estrone on expression of c-myc protein in the epiphyseal plate of fetal mouse long bone was detected by immunohistochemistry procedure in vitro. The result showed that the concentrations of estrone areas of positively staining cells increased significantly in proliferative zone at 10(-9) mol/L, in proliferative zone and resting zone at 10(-8) mol/L, and in resting zone, proliferative zone and hypertrophic zone at 10(-7) mol/L respectively. It was considered that estrogen might enforce endochondral bone formation by enhancing expression of c-myc in long bone.

Animals↗
PubMed2000

[Usefulness of Cofiler PCR amplification kit in parentage testing].

Parentage testing was performed by using multiple PCR and automated genescan and genotype analysis. Parentage was excluded in 36 cases, including 22 of 149 paternity trios and 14 of 37 paternity duos. In the 22 trios and 14 duos in which paternity was excluded, a mean of 6.1 and 5 incompatible STR markers were noted. The application value of six loci which included in the Cofiler amplification kit was showed here. The discrimination power ranged from 0.8023 for TPOX to 0.9203 for D16S539. The cumulative power of exclusion was provided as 0.9825. Three mutation were found (one each at D3S1358, TPOX, CSF1PO). For most nonexcluded paternity duos, only when the Cofiler amplification kit was used in conjunction with Profiler Plus kit, the RCP value was acceptable. The data showed that the Cofiler kit could play an important role in cases of paternity duos.

Forensic Medicine↗
PubMed2000

[A clinical study on PA-MSHA vaccine used for adjuvant therapy of lymphoma and lung cancer].

The objective of this study was to evaluate the effectiveness and safety of pseudomonas aeruginosa MSHA vaccine (PA-MSHA vaccine) used as an immune modulator. The study was carried out after the design of a non-blind, randomized controlled trial. The malignant lymphoma patients were divided into experiment group (45 cases) and control group (43 cases). Likewise were distributed the lung cancer patients: 44 cases in experiment group and 45 cases in control group. The two experiment groups received chemotherapy + PA-MSHA vaccine. The two control groups were given chemotherapy alone. The results showed that the clinical efficacy rate was 95.56% for the exp. group and 69.77% (P < 0.01) for the control group of the malignant lymphoma cases; the clinical efficacy rate was 59.09% for the exp. group and 42.22% (P < 0.01) for the control group of the lung cancer cases. The infection rate was 17.78% for the exp. group and 37.21% (P < 0.05) for the control group of the malignant lymphoma cases; the infection rate was 15.91% for the exp. group and 40.00% (P < 0.05) for the control group of the lung cancer cases. The comprehensive immune effectiveness rates for the exp. group and control group of the malignant lymphoma cases were 77.78% and 23.26% (P < 0.01) respectively. The comprehensive immune effectiveness rates for the exp. group and control group of the lung cancer cases were 84.09% and 35.56% (P < 0.01) respectively. Adverse reactions were found in 5 cases, of which, one was given medical care while the others automatically recovered. These results indicate that PA-MSHA vaccine, as a new kind of immune modulator, can improve the effectiveness of treatment for tumor with low adverse reaction rate.

Adjuvants, Immunologic↗
PubMed2000

[A comparative study on the capacities of different strains of Streptococcus sanguis for P-aminobenzoic acid production].

This study was intended to compare the capacities of different strains of Strep, sanguis for P-Aminobenzoic acid (PABA) production. The synthesis of PABA during the growth of four strains of Strep. sanguis was measured by the reversed-phase high-performance liquid chromatographic method. The results showed that the concentrations of PABA synthesized by S. sanguis 10556, S. sanguis 10557, S. sanguis S34 and S. sanguis H7-4. Were 1.979 +/- 0.081 micrograms/ml, 1.383 +/- 0.193 micrograms/ml, 1.983 +/- 0.052 micrograms/ml and 1.032 +/- 0.229 micrograms/ml, respectively, and in term of PABA concentration, S. sanguis 10556 was significantly different from S. sanguis 10557 and S. sanguis H7-4; S. sanguis S34 was significantly different from S. sanguis 10557 and S. sanguis H7-4. No significant difference was found between S. sanguis 10556 and S. sanguis S34, nor between S. sanguis 10557 and S. sanguis H7-4, either. In conclusion, the method is simple, rapid and accurate. S. sanguis did synthesize PABA, and the difference in ability for PABA formation existed among the four strains of S. sanguis. This study is helpful to researches on the symbiosis between S. sanguis and S. muntans and to determination of their role in the microbial homeostasis of dental plaque.

4-Aminobenzoic Acid↗
PubMed2000

[Screening of acrystalliferous mutants from Bacillus thuringiensis and their transformation properties].

After elevating growth temperature of YBT-1463 and other 8 Bacillus thuringiensis parental strains to 42 degrees C, 9 acrystalliferous(Cry-) mutants were obtained, and then a series of partial plasmid-cured mutants were further obtained from 3 Cry- mutants BMB151, BMB154 and BMB160 by elevating temperature to 44 degrees C. One of which, BMB170, was further treated by elevating temperature to 46 degrees C and adding 0.05% SDS as the plasmid-curing agent. The resulting mutant, which was designated BMB171 and had no resident plasmid, was finally obtained. The studies on the transformation efficiency and stability of Cry- mutants showed that the transformation frequencies, as well as stability of several exogenous plasmids(pHT3101, pBMB1736, etc.) introduced into Cry- mutants by electroporation, were correlated with the numbers of resident plasmids bearing by the relevant recipients, the patterns of plasmid replicons and the sizes of those exogenous plasmids. Meanwhile, a much higher electro-transformation frequencies of Cry- mutants than the parental strain YBT-1463 was found, and the highest of the transformation frequency, in BMB 171, could reach up to 10(7) transformants/microgram DNA, and the stability of those exogenous plasmids in BMB171 were also higher than in other Cry- mutants and YBT-1463 strain.

Bacillus thuringiensis↗
PubMed2000

[Inhibitory effects of N-(4-hydroxylphenol) retinamide on transformed human bronchial epithelial cells in vitro and reconstructed human bronchial epithelium in vivo].

Precancerous lesion is one of most important steps in tumorigenesis. It has been shown that retinoids have reliable effects on controlling many kinds of animal tumor and malignant tumor cell lines in vitro, but there is no laboratory report on the biological effect of retinoids on the precancerous lesion of human lung cancer. In this study the methods including of cell serum-free culture, precancerous model of human bronchial epithelium reconstructed in rat trachea/xenotransplanted in nude mice, flowcytometry, immunohistochemistry, TUNEL and pathological observation have been used to study the biological effects of N-(4-hydroxylphenol) retinamide (4-HPR), one new kind of retinoids, on transformed human bronchial epithelial cells in vitro and premalignant human bronchial epithelium in vivo. The results showed that in the study in vitro, the proliferation of transformed human bronchial epithelial cells, the ratio of cells in S phase, and the percentage of cells that positively react to antibody Ki-67 and mpm-2 were inhibited, but apoptotic cells were induced significantly by 4-HPR exposure. At the experiment in vivo, both growth rates and precancerous grades of the reconstructed human bronchial epithelium were reduced, and apoptotic cells were also observed in epithelium after 4-HPR treatment. The results suggested that 4-HPR is one of hopeful chemopreventive medicines to lung cancer.

Adult↗
PubMed2000

[The somatic embryogenesis and establishment of transformation experiment system in Larix principis-Rupprechtii].

Larix principis-Rupprechtii is one of the superior afforestation forest trees growing in north China. Embryogenic cultures were initiated from immature zygotic embryos of Larix principis-Rupprechtii on S culture medium containing 2, 4-D 0-2.2 mg/L, KT and BA each at 0-0. 8 mg/L. Embryogenic calli were subcultured and multiplicated on S + B culture medium containing dropping off each hormone concentration. We set up 33 steady-going embryogenic cell lines; We studied on the growth stage and genotype differences of every embryogenic cell lines; and Finded more than 10 high-frequency somatic embryogenesis cell lines such as 2K, 2T, 2I, 2J, 3C etc.. The number of 2T somatic embryos reaches 314/per gram of embryogenic tissue and the number of 3C somatic embryos is 185/per gram of embryogenic tissue. The re-induction method of Larix principis-Rupprechtii from somatic embryos was used to produce renewable embryogenic cultures and steady-going embryogenic cell lines effectively. Mature somatic embryos can germinate and develop further into plantlets when they are isolated and cultured on a hormone-free WPM culture medium. The regeneration plantlets were obtained. Furthermore, the transformation with a truncated gene of Bacillus thuringensis (B. t) were carried out, the PCR showed positive results, because of this, embryogenic cell line of Larix principis-Rupprechtii can be used for transformation experiments to support further breeding in forestry.

Cell Line↗
PubMed2000

[Bacteriological study of single nasal sinusitis and sensitivity of antibiotics].

OBJECTIVE: To properly understand the bacterial distribution and susceptibility to antibiotics in the sinus of nasal sinusitis. METHOD: The mucosal and secretion in sinus were taken from 135 patients who suffered with single nasal sinusitis, by functional endoscopic sinus surgery, were cultured for bacteria. Meanwhile the antimicrobial susceptibility was determined for ordinary antibiotics. RESULT: The bacterial growth was present in 88.15% of cases, mixed bacterial growth was present in 52.10% of all bacterial, anaerobe growth was present in 39.06% of all bacteria, the susceptibility to penicillin was in 53.12% of all bacteria and cefaolin was in 87.50%. The susceptibility to metronidazole was in 94.67% of all anaerobes. CONCLUSION: We think the method that penicillin in combination with streptomycin and metronidazole, sufameth oxazole united with metronidazole, cefaolin added metronidazole were effective in nasal sinusitis treatment before the antimicrobial susceptive examination had been done.

Anti-Bacterial Agents↗
PubMed2000

[Resources and distribution of Cordyceps sinensis in Naqu Tibet].

This paper reported the resources and distribution of Cordyceps sinensis in Naqu district, the principally grown zone in Tibet. The investigation showed that the yearly yield of Cordyceps sinensis are 7000 kg, the distribution areas are Baqin, Suoxian, Biru, Jiali, Naqu and Nierong county at 30 degrees 20'-32 degrees 48' N, 92 degrees 0'-94 degrees 50' E. The rangs of vertical distribution from the elevation 5000 m to 4100 m; the ecological geographical distribution is affected mainly by vegetation, soil, temperature and humidity.

Animals↗