Population remains top priority for China.
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Asia↗
Biomedical subjects
H Li
Publications and source records attributed to H Li.
[The effect of ribozyme RzDS on duck hepatitis B virus].
To study the effect of ribozyme in vivo, the hammerhead ribozyme RzDS was designed and synthesized, which aims at the pregenome RNA of DHBV(LJ-76) at the 736 site of the genome. The RzDS cleaved efficiently its substrate in vitro. We constructed pJ-RzDS, in which RzDS was inserted into pJ120 plasmid under the control of PII promoter. After homogenous recombination with the vaccinia virus, Tian Tan strain, we got the recombinant(V-RzDS) which carried RzDS. V-RzDS was injected into nestling Beijing ducks preinfected with DHBV. On the tenth day after intravenous injection, DHBV DNA and DHBsAg in serum were detected. The quantity of DHBV DNA and DHBsAg were evidently lower than that of the controls, when V-RzDS injection was simultaneously given with DHBV. It suggests that RzDS can block replication and expression of DHBV in vivo.
Animals↗
[Dental welding titanium and its clinical usage].
Due to its excellent biocompatibility, desirable chemical and mechanical properties, Titanium has been used for implant denture, RPD and FPD, where welding techniques were indispensable. This paper introduces 5 useful modern ways to weld Titanium and their clinical usage. They are: laser, plasma welding, TIG, infraned brazing and Hruska electrowelding.
Dental Soldering↗
[Study on the Rheum palmatum volatile oil against HBV in cell culture in vitro].
The antiHBV effect of Rheum palmatum Volatile oil was studied by using 2215 cell line transfected with HBV DNA. At the same time MTT method was applied for the detection of cytoxicity of drugs, selecting acyclovir(ACV) as control medicine. It turns out that the toxic concentration of Rheum palmatum Volatile oil for 50% cells was (CD50) > 1.25 x 10(-1) g/L. When concentration was below 0.625 x 10(-1) g/L, the survival rate of cells was over 90%. The maximum inhibitory rates for HBsAg and HBeAg were 70.71 +/- 5.4% and 30.99 +/- 5.3% respectively. This shows Rheum palmatum Volatile oil possesses the effect of antiHBV in vitro.
Acyclovir↗
[An investigation on chromosome aberration of SO-Rb50 cloned cell strains].
PURPOSE: To compare the differences of chromosome aberration among 3 cloning cells (MC2, MC3 and MC4) of SO-Rb50 cell line. METHOD: G-banding and karyotype analysis were performed on the 11th passage cells of MC2, MC3 and MC4 cell strains. RESULTS: Both numerical abnormal and structural aberrations of chromosomes could be observed in these 3 cloned cell strains. Diploid cells had the preponderance over the aneuploid cells. However, some cells showed pseudiploid karyotypes. Several kinds of structural chromosome aberrations were observed. The chromosome aberrations in the same passage of different cell strains were different. Aberration of chromosome 13 was rare and the aberration feature were different in 3 cloned cell strains. Five marker chromosomes were identified. M1, t(1;1) qterp35::q24-ter could be found in all cell strains. Other markers were seen in different cell strains respectively. In our experiment, two marker chromosome in chromosome 2, M4 and M5, were found in SO-Rb50 cell line for the first time. CONCLUSION: Chromosome aberrations were different with different cloned cell strains. Combined with formerly study in SO-Rb50 cell line, we found the chromosome aberration had dynamic changes during the long-term culture in vitro. We suggest that aberration of chromosome 13 is not the only cause of Rb; aberration of chromosome 1, a common event in some neoplasias as well as in SO-Rb50, plays a meaningful role in the immortalization of this cell line; other aberrations observed in our experiment could be considered as evidences of genomic instability of the cell strains and presumably enhance the growth potential of the cells in which they develop.
Cell Line↗
[Preparation of liposome encapsulated daunorbicine and determination of daunorubicine of aqueous humor in rabbit eyes].
PURPOSE: To investigate the method of determination the concentration of daunorubicine(DNR) and liposome encapsulated daunorubicine(LDNR) of aqueous humor in rabbit eyes. METHODS: After extracapsular lens extraction, 0.1 ml of 1 mg/ml DNA and LDNR were injected into the anterior chamber. At the 12, 24, 48 hours and 1 week after operation, the aqueous humor were aspirated to determine the concentration of DNR by high performance liquid chromatography(HPLC). RESULTS: At the 12, 24, 48 hours after operation, DNR were determined in all eyes, but at one week after operation, the DNR could only be detected in LDNR group. The concentration of DNR in LDNR group were higher than DNR group.
Animals↗
Determination of intraocular lens tilt and decentration using simple and rapid method.
PURPOSE: To determine the tilt and decentration of implanted intraocular lens (IOL) in vivo one year postoperatively. METHODS: A retrospective study was performed on 67 eyes by the method introduced by Guyton using the third and fourth Purkinje imagesm through undilated pupil. RESULTS: The average decentration of implanted IOL was 0.68 mm, and the average tilt was 6.03 degrees. The result was similar to the histopathological study in postmortem eyes and the measurement in vivo. Linear-regression analysis showed there was no relationship between the tilt and decentration and the residual astigmatism, axial length, IOL power, etc. CONCLUSION: The result is similar to the other methods. The method using the third and fourth Purkinje images is simple and easy to perform. It can be used for determining the IOL position through undilated pupil and does not require special apparatus.
Adult↗
[Study of photoreflectance in Cd1-xMnxTe/Cd1-yMnyTe superlattices of II - VI diluted magnetic semiconductors].
The observation of photoreflectance spectra of Cd1-xMnxTe/Cd1-yMnyTe superlattices was carried out at temperature T = 80K. The samples were grown by molecular beam epitaxy (MBE) technique. The heavy-and light-hole excitonic transition structures 11H, 22H, 33H and 11L were observed and the theoretical calculations, including the strain effects, were performed. By comparison, both agree well.
English Abstract↗
[The constant-in time DC component in the time-resolved FTIR spectroscopy].
The direct current component in the interferogram of conventional FTIR spectroscopy is expressed by integral(infinity)0 B(sigma)dsigma. However, in time-resolved FTIR spectroscopy, the direct current component Idc(tau) also depends upon tau, the time which IR signal appears. Idc(tau) is then represented by integral(infinity)0 B(sigma, tau)dsigma, called as constant-in-time DC component by us. Idc(tau) is proportional to the signal intensity B(sigma). Idc(tau) can not be filtered by any band pass filter. After Fourier transforming, the Idc(tau) converts to a strong peak at 0cm(-1) in the IR spectrum. We call it as constant-in-time zero frequency signal Btau(0). Either Idc or Btau(0) can be used to monitor a variety of experimental conditions, such as the variation of gas pressure, laser intensity, the carbon deposition on the optics, etc. They can also be applied to measure the instrumental response time and the band pass frequency.
English Abstract↗
[Simultaneous determination of metronidazolum and vitamin B6 by the derivative spectrophotometry].
A new method for simultaneous determination of metronidazolum and vitamin B6 was established by the third derivative spectrophotometry in 0.1 mol/L HCl solution. The detection limits were 0.81 microg/mL for metronidazolum and 0.16 microg/mL for vitamin B6. The linear range of determination was 1.6-22.4 microg/mL for both metronidazolum and vitamin B6. This method has been applied to the determination of metronidazolum and vitamin B6 in tabellae metronidazoli compositae with satisfactory results. The coefficients of variation are below 2.26 and 2.65% and the recoveries are 93-102% and 99-101% for metronidazolum and vitamin 6, respectively.
Limit of Detection↗
[Synthesis of new pyrazoline fluorescent compounds and their IR spectra and fluorescence property].
The Fluorescent compounds of pyrazoline have been used in many field. According to Schellhammer theory, we designed and synthesized five new benzothiazoyl pyrazoline compounds. Their infrared spectra and fluorescent spectra of five compounds were detected. The results showed that five compounds have fluorescence, fluorescence emission wavelength is about 450nm. Effect of different substituents on the fluorescent intensity was investigated.
Fluorescent Dyes↗
Hepatitis G virus infection in screened Chinese blood donors.
BACKGROUND AND OBJECTIVES: To determine the prevalence of the recently identified hepatitis G virus (HGV)/GBV-C in screened Chinese paid blood donors. MATERIALS AND METHODS: Two hundred and seventy-nine plasma samples were tested for HGV RNA by RT-PCR with nested primers from the 5'-noncoding region of GBV-C. All samples were obtained from plasma or blood bags that had been screened twice by routine selection tests (ALT, HBsAg, Anti-HCV, anti-HIV, and syphilis) and were available for clinical use. RESULTS: HGV RNA was detected in 2 (4%) of 50 paid plasma donors from the Beijing Red Cross Blood Center, 1 (2%) of 50 paid blood donors from Taiyuan, and 9 (5%) of 179 paid blood donors from Hebei, a total HGV detection rate of 4.3% (12/279). CONCLUSIONS: Our data suggest that HGV infection is relatively frequent even in screened donors, at least in paid screened donors, although larger-scale studies are required.
Blood Donors↗
Immunological characterization of cell-surface and soluble forms of membrane type 1 matrix metalloproteinase in human breast cancer cells and in fibroblasts.
Membrane type (MT) 1 matrix metalloproteinase (MMP) activates progelatinase A (pro-MMP-2), a type IV collagenase, on the cell surface of tumors; however, its function in breast cancer progression and metastasis is not fully understood. To examine the expression of MT1-MMP in breast cancer cells and fibroblasts, a specific rabbit antibody (Ab) directed against a unique synthetic peptide derived from the human MT1-MMP catalytic domain was produced, purified, and characterized. This Ab is not likely to cross-react with MT2-, MT3-, or MT4-MMP or any other MMPs. MT1-MMP expression and pro-MMP-2 activation were stimulated by concanavalin A in two human breast carcinoma cell lines (BT549 and MDA-MB-231) and in normal human fetal-lung fibroblasts (HFL-1) and were slightly upregulated by breast cancer cell-fibroblast interactions. Both pro-MT1-MMP in plasma membrane (63.4 kDa) and the soluble forms of the enzyme in culture medium (57.6 and 25-30 kDa) were detected by immunoblot analysis, suggesting that cell-surface MT1-MMP exhibits an active conformation without the removal of its propeptide domain and that the mature enzyme is shed into the medium. In breast cancer cells, MT1-MMP and a recombinant catalytic domain of MT1-MMP were unable to activate pro-matrilysin, indicating that MT1-MMP is not a universal activator of all MMPs. MT1-MMP may play an important role in the invasive growth and spread of breast cancer cells by specifically activating pro-MMP-2 to cleave the connective-tissue barrier. Furthermore, use of the specific Ab may aid in the investigation of the role of MT1-MMP in human tumors.
Amino Acid Sequence↗
[The types and distributive features of gene mutation on beta-thalassemia in three districts in northwest China].
OBJECTIVE: To sum up the results of gene analyses on beta-Thalassemia in three districts in northwest China and discuss the types and distributive features of the mutation. METHODS: Polymerase china reaction in combination with dot-blot hybridization of allele-specific oligonucleutide probes(PCR-ASO). RESULTS: In the gene analysis carried out in 85 probands with beta-Thalassemia, twelve types of gene mutation were identified from five nationalities. CD8(-AA), CDs8-9(+G), CDs27-28(+C) heterozygote and [-28(A-->uG). CD17(A-->uT)/N] double heterozygote were firstly assayed in these districts besides the common types in Chinese, of which, [-28(A-->uG). CD17(A-->uT)/N] as double gene mutation in the same chromosome is rare. CONCLUSION: There are significant differences in the distribution and nationality features of gene mutation types for beta-Thalassemia in the three districts, so the three districts as a whole is an area with special distributive features of the disease.
Adolescent↗
[Detection of the mutant phenylalanine hydroxylase gene by dideoxy fingerprinting].
OBJECTIVE: To establish a method with high efficiency in detecting phenylalanine hydroxylase (PHA) gene mutations and hence to rapidly diagnose prenatal fetals with phenylketonuria. METHODS: Dideoxy fingerprinting (ddF) was used. It is a hybrid method of dideoxy sequencing and single strand conformation polymorphism (SSCP); it can effectively detect the presence of mutant genes and would not be limited by the length of the amplified products, by ddF, the mutant genes Y165X, Y204C and Q355H of PAH genes were detected. RESULTS: Many bands showed altered migration, compared with the controls. Abnormal band migration in Y165X and Q355H was also detected by SSCP, but it was not detected in Y204C which had large amplified products. CONCLUSION: Compared with SSCP, ddF is a more sensitive method detecting gene mutations in large fragments, ddF is a practicable method for detecting gene mutations.
DNA Fingerprinting↗
Analysis of age of onset data from case-control family studies.
Age of onset data from case-control family studies are frequently used to study the relationship between disease and environmental or genetic factors. Dependence of age of onset within family and case-control sampling designs must be taken into account in analyzing such data. In this paper, we propose a parametric likelihood approach to study the relationship between disease risk and covariates, allowing for any correlations in age of onset of disease between family members and to study the familial association in age of onset of disease due to genetic factors, after adjusting for other shared covariates within the family. The method provides a way to combine the information relating disease incidence to risk factors in relatives with the information contained in the case/control contrasts in order to obtain more precise estimates of the effects of the putative risk factors. A data set from a case-control family study of lung cancer is used to illustrate the method. The analysis indicated that history of smoking, passive smoking, and history of chronic obstructive pulmonary disease are positively associated with lung cancer risk, and that, after adjustment for these risk factors, there is little evidence of familial aggregation in lung cancer risk.
Adult↗
Chronically denervated rat Schwann cells respond to GGF in vitro.
C-erbB receptor/neuregulin signalling plays a significant role in Schwann cell function. In vivo, Schwann cells up-regulate expression of c-erbB receptors in the first month after injury, but receptor expression is down-regulated with time to levels that are not detectable immunohistochemically. The inability of chronically denervated Schwann cells to respond adequately to signals derived from regenerating axons may be one reason why delayed repair of an injured peripheral nerve frequently fails. We have examined the effects of GGF on denervated Schwann cells in vitro. A modified delayed dissociation technique was used to obtain adult rat Schwann cells from the distal stumps of transected sciatic nerves which had been acutely (7 days) or chronically (2-6 month) denervated. We found that in vitro denervated Schwann cells invariably expressed p75NTR and c-erbB receptors. There was a progressive decrease in total cell yield and the percentage of cells with Schwann cell phenotype (p75NTR and/S-100 or/laminin or /GFAP or/c-erbB positive); proliferation rate; migratory potential; and expression of the cell adhesion molecules N-CAM and N-cadherin, with increasing time of denervation. Addition of GGF2 had a significant stimulatory effect upon Schwann cell proliferation and migration, and an increased proportion of Schwann cells expressed N-CAM and N-cadherin, suggesting that these responses were mediated via GGF/c-erbB signalling. Our results support the view that it may be possible to manipulate chronically denervated Schwann cells so that they become more responsive to signals derived from regrowing axons.
Animals↗
Antibacterial activity of antibiotic coated silicone grafts.
PURPOSE: Postoperative infection remains one of the most serious complications of implantation of penile prostheses. Attempts to reduce the rate of infection by spraying the prosthesis with an antibiotic solution prior to implantation, along with perioperative antibiotics, have failed to eradicate infection. No published studies have evaluated the effect of antibiotic coating of penile prostheses. In this study, we evaluate the antibacterial effect of antibiotic-coated silicone strips as a surrogate for the penile prosthesis. MATERIALS AND METHODS: Strips coated with several different antibiotics were dipped in bacterial solutions containing Staphylococcus epidermidis or S. aureus and implanted subcutaneously in adult Sprague-Dawley rats. After a week, the strips were removed, and the number of bacteria on the strips and in the surrounding tissue were determined. The in vitro antibiotic activity of the antibiotic-coated strips against the same organisms was also determined. RESULTS: In the group of rats that received silicone strips contaminated in vitro with S. epidermidis, six of nine control rats yielded strips and tissues containing heavy bacterial growth. None of six strips coated with rifampin/minocycline yielded bacterial growth, nor did any of the seven strips coated with vancomycin. One of seven rats that received amikacin-coated strips had infection of the strip. The tissue results were similar to the strip results. In the group using S. aureus as the contaminating bacterium, the strips and tissues from eight of nine control rats yielded bacteria. None of the six rifampin/minocycline-coated strips yielded bacteria, while two of seven vancomycin-treated strips and two of six amikacin-coated strips were infected with S. aureus. The difference in bacterial growth between controls and antibiotic-coated strips reached a level of statistical significance for the rifampin/minocycline and vancomycin groups and was highly significant for the rifampin/minocycline groups. CONCLUSION: The experimental results presented here suggest that coating silicone graft material with antibiotics, particularly rifampin/minocycline, can reduce the incidence of graft colonization in contaminated wounds in rats, even in the absence of systemic antibiotics. These graft materials may prove useful in preventing the infection of penile prostheses.
Animals↗