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Biomedical subjects

Z Chen

Publications and source records attributed to Z Chen.

At least 703 records · Page 39Linked to original sources
PubMed1999

[The relationship between anticardiolipin antibodies and fetal intrauterine growth retardation].

To investigate the relationship between anticardiolipin antibodies(ACA) and fetal intrauterine growth retardation(IUGR), serum ACA was determined in 60 pregnant women by enzyme linked immunosorbent assay(ELISA). Binding index(BI) of ACA-IgM or ACA-IgG in cases with IUGR(n = 30) was significantly higher than that in normal pregnant women(n = 30) (P < 0.05). There was no obvious relationship between the weight of neonate and BI of ACA-IgM(r = 0.1904), ACA-IgA(r = 0.1829) or ACA-IgG(r = 0.2013) in IUGR group. Increased ACA-IgM had a negative association with C3 (r = -0.4108, P < 0.05) and C4(r = -0.4092, P < 0.05), respectively. After routine therapy for IUGR during 27-35 weeks' gestation, the weights of neonates were 2436.87 +/- 437.29 gram in ACA-IgG positive group(n = 15) and 2905.33 +/- 195.95 gram in ACA-IgG negative group(n = 15). There was a statistical significance between these two groups(P < 0.01). It is concluded that ACA may play an important role in the pathogenesis of IUGR. The determination of ACA is also useful for early diagnosis and treatment of IUGR.

Adult↗
PubMed1999

[Establishment of sandwich ELISA with McAbs to measure histidine-rich glycoprotein in plasma].

The objective of this paper is to establish a method using sandwich ELISA with McAbs to measure plasma histidine-rich glycoprotein (HRG). The results showed that this method, with a working range from 2.5 ng.ml-1 to 80 ng.ml-1, provided the lower limit of detection of 1 ng.ml-1, the average intra-assay CV, the interassay CV and the recovery rate of HRG were 8.2%, 11.5% and 89.1%, respectively. Interference by antithrombin III and human albumin was not significant. With this method, the concentration of plasma HRG from healthy donors was (110.3 +/- 9.7) mg.L-1, and the value of plasma HRG in liver cirrhosis was (79.5 +/- 12.6) mg.L-1. These results suggest that sandwich ELISA with McAbs is high sensitive, precise and specific.

Adult↗
PubMed1999

[Seed germinative characteristics and embryo development of Schisandra chinensis (Turcz.) Bail].

OBJECTIVE: To detect the germinative character of S. chinensis seeds. METHOD: Using low temperature and gibberellin treatment. RESULT: The breach rate of seeds was increased by both low temperature and gibberellin, but the breach on different seeds appeared untidy, which showing a character. The embryo development is normal before breaching and increased in volume rapidly after breaching. CONCLUSION: The bypoplasia of embryos is not the primary reason for long dormancy of the seeds.

Plants, Medicinal↗
PubMed1999

[Determination of chlorogenic acid in chrysanthemum morifolium Ramat.flower].

OBJECTIVE: To determine the contents of chlorogenic acid in flower of Chrysanthemum morifolium. METHOD: Column: Nova-Pak C18, 4 microns, 4.6 mm x 250 mm, mobile phase: MeOH-0.1 mol.L-1 NaH2PO4(pH 2.65)30:70, detection wavelength: 328 nm. RESULTS: Flowers of 20 batches bought from the market were analysed. Contents of chlorogenic acid were 0.060%-0.467%. CONCLUSION: Chlorogenic acid is a suitable component for the quality control of C. morifolium.

Chlorogenic Acid↗
PubMed1999

[Immunogenicity and immunoprotection of a leptospiral DNA vaccine].

Leptospirosis is one of the most widespread zoonosis. Immunization of NZW rabbit with plasmid DNA constructs encoding leptospiral endoflagellin can induce specific antibody response in the animal. The vector, VR1012 consists of a pUC18 backbone with the cytomegalovirus (CMV) IE1 enhancer, promoter, and intron A transcription regulatory elements and the BGH polyadenylation sequences driving the expression of leptospiral endoflagellar gene, flaB2. In this study, a pair of oligonucleotide primers were designed to amplify the endoflagellar of L. interrogans serovar lai. An approximately 840 bp fragment was generated with PCR and inserted into expressed plasmid vector, VR1012, after the fragment of VR1012 were digested respectively with EcoRV and Sall. A recombinant plasmid (designated VR1012 + flaB2) was obtained. Plasmid encoding leptospiral endoflagellin was injected into quadriceps of NZW rabbits. This resulted in the generation of specific leptospiral antibody with very high ELISA titer. Immunoprotection was performed in guinea pigs. The group "VR1012 + flaB2" had higher survival rate, compared with the group "VR1012 only" (control) and the group "Normal Saline only" (control). The result suggests that the technique of DNA injection should have an advantage over certain previous vaccine technologies.

Animals↗
PubMed1999

[Alignment of DNA sequences of ompL1 genes of insert fragment of recombinant plasmid, pDC38 of L. interrogans serovar lai and L. kirschneri].

In a previous study a genomic library of L. interrogans serovar lai was constructed by the present authors. Hybridization analysis (In situ, dot blot, Southern blot) with the DNA fragment containing OmpL1 (alpha-32P labeled) was performed. One of positive clones designated pDC38, was analyzed with 9 restriction enzymes (EcoRI, Bam HI, Hind III, Bgl, XbalI, ScaI, KpnI, PstI, Dra II). DNA hybridization was applied to analyze the homology of the recombinant fragment of ompL1 with the DNA of 18 strains of L. interrogans. The results showed that the homology of fragments of ompL1 were present in pathogenic Leptospira strains, but they were not in the non-pathogenic Leptospira biflexa strain Patoc I, Leptonema illini strain 3055. Therefore, Dr. David A. Haake performed the sequencing of pDC38. The results showed that pDC38 contained two inserts of 2.7 kb and 3.0 kb. The 3.0 insert contained a complete copy of the ompL1 gene. Dr. David A. Haake amplified the ompL1 gene using PCR primers specific for the ends of the gene and cloned the amplicon into pBluescript KS for sequencing. The alignment of complete DNA sequences of ompL1 of L. kirschneri and L. interrogans serovar lai showed the similarity of nucleotide sequences was 90%, variation was 10%. The derived amino acid sequence showed there was a high degree of amino acid sequence homology with ompL1 of L. kirschneri. These findings indicated that ompL1 gene was one of the important outer membrane protein genes in the L. interrogans serovar lai and using the probe pDC38 might provide a good tool for classification and identification of Leptospira.

Amino Acid Sequence↗
PubMed1999

[Cytocompatibility of three substituted materials of human beings' hard tissue].

OBJECTIVE: To evaluate the osteocompatibility of three substituted materials of human beings' hard tissue (hydroxyapatite, bioglass ceramic and Ti-6Al-4V) and a new experimental method for evaluating the osteocompatibility of replaced materials of hard tissues in vitro. METHODS: The isolated osteoblasts from parietal and frontal bones of Sparague Dawley rats from 1 day to 3 days were used to estimate osteocompatibility of three substituted materials in vitro. The cells were inoculated onto specimens of HA, BGC and Ti-6Al-4V for 1 day, 3, 5 and 7 days, then the morphology and proliferating rates of cells on different materials were tested. RESULTS: Rat osteoblasts could attach, spread and proliferate on three materials as normal cells, and proliferating rates of cells on HA and BGC surface were as the same as normal, but that on Ti-6Al-4V was lower than the normal cells. CONCLUSION: The osteocompatibility of HA and BGC are better than that of Ti-6Al-4V and rat osteoblast culture system can be used to evaluate the osteocompatibility of substituted materials in vitro.

Alloys↗
PubMed1999

[Design of HA/Ti biomedical implants with the use of ion-beam-assisted deposition].

Hydroxy-apatite (Ca10(PO4)6(OH)2,HA) is a potential material for coating on metal implants owing to its bioaffinity and osteo-integration to body. At present, in addition to bulk HA directly used in restoration and reconstruction surgery, hydroxy-apatite is also coated on metal implants by plasma-spraying method, adhesion and sintering. However, these kinds of biomaterials are restricted in application due to their insufficient strength and weak bonding. It is of great advantage to modify the surface of titanium and its alloy by ion-beam-assisted deposition (IBAD) combining ion implantation with physical vapor deposition(PVD). This paper is focused on the design of HA/Ti implants by ion-beam-assisted deposition technique and the computation of fabricating parameter using Trim96 program. The present investigation lays a foundation of further researches and application.

Coated Materials, Biocompatible↗
PubMed1999

[Analysis of Parkinson's EEG based on the complexity measure].

EEG represents the electricy activity of neurons in human brain; it is of course repeatedly used for studying and analyzing the brain activity and the status of brain function. We analyzed the Parkinson's and normal persons' EEG, with the aid of Kc complexity and C1 complexity defined by Kolmogorov and Xujinhua respectively. The results of the analysis on the data from 200 patients and 200 normal persons indicate that the complexity of EEG can be regarded as a feature classifying the Parkinson's EEG and normal persons' EEG.

Algorithms↗
PubMed1999

[Simultaneous determination of gibberellins A1 and A3 in foxtail millet seedlings by high performance liquid chromatography].

Gibberellin A1(GA1) and Gibberellin A3(GA3) in millet seedlings were simultaneously determined by HPLC on a Zorbax-ODS-C18 (4.6 mm x 250 mm, 10 microns) column, using a mobile phase consisting of V (0.02 mol/L phosphate buffer solution, pH 4.0):V(methanol) = 2.2:1, a flow rate of 0.8 mL/min and a UV detection at 210 nm. GA1 and GA3 were separated completely in 10 min. Correlation coefficients for linear equations were 0.9986 and 0.9978, recoveries were 102.54% and 99.59%, respectively. Two normal cultivars and their dwarf-mutants were determined by this method. The results showed that both GA1 and GA3 were discovered in foxtail millet seedling, and endogenous mass ratio of GA1 and GA3 in foxtail millet dwarf-mutants were significantly lower than those in normal cultivars, and the concentrations of endogenous GA1 and GA3 were important factors for plant-height.

English Abstract↗
PubMed1999

[Evaluation on cytotoxicity of gallium alloy].

Cytotoxicity is an important indicator to the biocompatibility of biomaterials. In this study, the cytotoxicity of Gallium alloy was evaluated by the method of cell relative growth rate in vitrousing L-929 mouse fibroblast. The cell relative growth rate of Gallium alloy was the absorbency ratio between the solution of Gallium alloy and negative control. The relative growth rates of Gallium aloy were converted into the scores of cytotoxicity. It was found from the results that Gallium alloy had no cytotoxicity.

Alloys↗
PubMed1999

[Purification and characterization of antifungal peptide LP-1].

An antifungal peptide LP-1 from Bacillus subtilis TG26 strain was purified by acid precipitation, acetone precipitation and Hi-pore reversed phase column chromatography. The molecular weight of LP-1 is 1057.3 D as determined by MALDI-TOF mass spectrometry, and its pI is 4.75 by PAG-IEF. It was also found to be thermostable. Its antifungal spectrum showed that LP-1 has strong inhibitory activity against many plant pathogenic fungi, such as Pythium aphanidermatum, Gibberella zeae, Alternaria longipe, Fusarium oxysporum f. lycopersici, etc.. The abnormal hyphal growth of Trichoderma viride caused by LP-1 such as swollen tips, twisted, short growth and cytoplasm condensation was also observed. Both ninhydrin reaction and peptide sequencing suggested that LP-1 is a cyclic peptide.

Anti-Bacterial Agents↗
PubMed1999

[Prokaryotic expressed trichosanthin and other two proteins have anti-fungal activity in vitro].

DNAs encoding Trichosanthin, tobacco class I Chitinase and tobacco class I beta-1, 3-Glucanase were expressed in E. coli, respectively. The expression products were assayed for their anti-fungal activity. All of three kinds of proteins show anti-fungal activity. When two of them combined, this activity was enhanced greatly. When three of them combined, the stronger anti-fungal activity was observed.

Antifungal Agents↗
PubMed1999

[Molecular cloning and sequencing of outer capsid protein gene of rice dwarf virus and its expression in Escherichia coli].

The S2 full-length cDNA of rice dwarf phytoreovirus which enocodes the viral outer capsid protein was cloned and its complete nucleotide sequence was determined. The results showed that S2 is 3512 bp long with a large open reading frame which encodes a protein of 1116 amino acids. It shares 94.6% and 95.4% identity with RDV of Japanese H isolate in terms of nucleotide and amino acid sequences, respectively, and it also shows some homology with VP2 of rotavirus at the level of amino acid sequence. The search of deduced RDV S2 amino acid sequence in Blast network found that there were 4 leucine-rich motifs in P2 protein, and ten amino acids within the hydrophibic region at amino-terminus could form an alpha-helix. Predicted secondary structure of S2 cDNA indicated that a hairpin and a stem loop are present in the 5'-end within 50 bp, and a stem loop in the 3'-end within 50 bp. RDV S2 partial and full-length sequences were then cloned into expression vector pET-11d & pTrcHisC. SDS-PAGE and Western blot proved that amino- and carborn-termini of P2 were successfully expressed in E. coli.

Amino Acid Sequence↗
PubMed1999

[Changes in transforming growth factor beta 1 mRNA and its clinical value in patients with schistosomal liver fibrosis].

AIM: To explore the changes in TGF-beta 1 mRNA in patients with schistosomal liver fibrosis. METHODS: Reverse-transcription polymerase chain reaction and dot blot analysis were used to determine the level of TGF-beta 1 mRNA in PBMC. The serum levels of hyaluronic acid, type IV collagen, laminine and procollagen III peptide were also measured simultaneously. RESULTS: The mean level (m +/- s) of PBMC TGF-beta 1 mRNA was significantly higher in late-stage schistosomiasis group (LSS) (1.26 +/- 0.14), liver cirrhosis group (LC) (2.05 +/- 0.81) and hepatocellular carcinoma group (HCC) than that in control group (0.62 +/- 0.40) (P < 0.05). PBMC TGF-beta 1 mRNA level was higher in LC and HCC than that in LSS (P < 0.05). No significant difference was found in TGF-beta 1 mRNA between PBMC and liver tissue in patients with HCC. All patients with increased fibrogenic activity (i.e., abnormal levels of serum HA, Col-IV and LN) had increased levels of TGF-beta 1 mRNA. CONCLUSION: The level of TGF-beta 1 mRNA is correlated with the fibrotic activity of liver, the increasement of TGF-beta 1 mRNA in schistosomiasis patients after praziquantel treatment might induce liver fibrosis.

Adult↗