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Biomedical subjects

Y Xie

Publications and source records attributed to Y Xie.

At least 235 records · Page 13Linked to original sources
PubMed1999

[CD59-blocked erythrocytes and hemolysis tests of paroxysmal nocturnal hemoglobinuria].

OBJECTIVE: To investigate the relationship between CD59 and traditional hemolysis tests for paroxysmal nocturnal hemoglobinuria. METHODS: To make different concentrations of CD59-blocked erythrocytes by mixing with normal erythrocytes, and investigate the relationship between quantitative abnormalities of CD59 and hemolysis tests. RESULTS: The hemolysis rate was positively related to the percentage of CD59-blocked erythrocytes. The greatest hemolysis of CD59-blocked erythrocytes was found in the CoF-initiated hemolysis test when the CD59-defects less than 16%, and the greater in Ham's test. When the CD59 defects were more than 16%, CD59-blocked erythrocytes hemolyzed to a greater extent in Ham's test than in the others. CONCLUSIONS: Quantitative differences of CD59 underlies the variability in hemolysis tests, and the CoF-initiated hemolysis test is the most sensitive in detection of small CD59-defects.

Antibodies, Monoclonal↗
PubMed1999

cDNA representational difference analysis of differentially expressed cDNA sequences in human nasopharyngeal carcinoma.

OBJECTIVE: To search differentially expressed sequences correlated with pathogenesis of human nasopharyngeal carcinoma (NPC), including the candidates of tumor suppressor genes. METHODS: Representational difference analysis (RDA) was performed to isolate differentially expressed sequences between cDNA from normal human primary cultures of nasopharyngeal epithelial cells and cDNA from NPC cell line HNE1. The source of differentially expressed products were proved by Southern blot, Northern blot and in situ hybridization. The fragments were cloned with pGEM-T easy kit and sequenced by the chain termination reaction. RESULTS: Four differentially expressed cDNA fragments were isolated in the fourth subtractive hybridization using cDNA from normal human nasopharyngeal epithelial cells as tester amplicon and cDNA from NPC cell line HNE1 as driver amplicon by cDNA RDA. These differential cDNA fragments revealed that they really came from the tester amplicon and were not expressed or down-regulated in the NPC HNE1 cells. Some of the genes were expressed only in human nasopharyngeal epithelial cells but deleted or down-regulated in the biopsies of NPC. Of these obtained clones, some were the sequences of the human known genes including house-keeping genes, the others represented novel gene sequences. CONCLUSION: The differentially expressed products including the candidates of tumor-suppressor genes may be associated with the initiation of the NPC.

DNA, Complementary↗
PubMed1999

[Experimental observation of origins of osteoblasts in guided bone regeneration in long bone].

OBJECTIVE: To study the origins of osteoblasts in guided bone regeneration (GBR) so as to understand the mechanism of GBR. METHODS: New Zealand rabbits were used. Standard ununited defect models were made in bilateral middle radial shaft of each rabbit. Randomly, one defect enveloped with silicon membrane as test, another without membrane as control. 12 rabbits were selected for X-ray examination weekly after procedure. 30 rabbits were divided into 6 groups, and sacrificed at 3 days, 1, 2, 3, 4, 5 weeks after surgery for histological observation by immunohistochemical staining of BMP, BGP. RESULTS: The sealed spaces were made by silicon membranes in the defects to prevent peripheral tissue ingrowing early. The defect spaces were filled by granulation tissue formed from proliferative endoperiosteal and medullary stromal cells in bone end. Histological characteristics after callus forming showed that there were 2 - 3 layers of osteoblasts in the surface of callus, and granulation tissue in the center of bone defect. The transforming region existed between the extending callus and granulation tissue, which consisted of a few of cells and a lot of stroma. Early proliferative endo-periosteal and medullary stromal cells in the bone end were positive against BMP, BGP. Some cells in the transforming region were positive against BMP, BGP after callus forming. CONCLUSIONS: Osteoblasts derive from endoperiosteum and medullary stroma in the early stage of GBR and from granulation tissue formed by proliferative endo-periosteal and medullary stromal cells in the later stage.

Animals↗
PubMed1999

[Inhibitory effects of recombinant human neurotrophin-4/5 protein on neurotoxicity caused by arsenic trioxide].

OBJECTIVE: To study preliminarily the inhibitory effects of recombinant human neurotrophin (hNT)-4/5 protein on neurotoxicity caused by arsenic trioxide (As(2)O(3)). METHODS: Nerve cells of the chicken embryonic forebrain and PC12 cells were co-cultured with recombinant hNT-4/5 protein and As(2)O(3) (0 - 16 micromol/L) for 24 and 48 hours, respectively, to observe the survival of nerve cells and the outgrowth of PC12 cells, with clone expression and recombination techniques. RESULTS: There was significant difference in survival rate of nerve cells between the experimental and control groups (P < 0.01) after co-culture for 48 hours, and survival rate and number of neuron outgrowth increased with the concentration of hNT-4/5 protein. CONCLUSION: Recombinant hNT-4/5 protein could inhibit neurotoxicity caused by As(2)O(3), which provided a basis to find an anti-toxic factor in the environment by genetic engineering.

Animals↗
PubMed1999

[Platelet stereological study in patients with HFRS].

To investigate the effects of stereological alteration of platelets on hemorrhage in hemorrhagic fever with renal syndrome(HFRS), platelet mean cross area(A), area density of alpha-granules(Na), volume density(Vv), the mean open tubule(OCS) and pseudopodia mean(M) were performed stereometric analysis in 12 patients with HFRS. The platelet A was observed, and no significant difference was found compared with the control(P > 0.05), while the number of pseudopodia M was higher, and the open tubule number was lower than those of the control(p < 0.01). The results suggest that in addition to the total platelet count decrement, the quality deterioration and functional activity abnormalities of platelets play an important role on the disordered hemostasis and coagulation in HFRS.

Adult↗
PubMed1999

[Correlative study on the level of serum type IV collagen, laminin and the diameters of portal veins in patients with viral hepatitis].

The contents of serum Type IV collagen and laminin were detected by radioimmunoassay and the diameters of portal veins were measured by B-mode ultrasound in 102 patients with different type of viral hepatitis. The results show that an increase of levels of Type IV collagen and laminin was found in patients with chronic severe hepatitis and fulminant hepatitis. The levels of Type IV collagen and laminin were obviously increased in the patients who have the diameter of portal vein > or = 12 mm compared with the patients who have the diameter of protal < 12 mm. There was a positive correlation between the levels of Type IV collagen, laminin and the diameters of portal vein.

Adolescent↗
PubMed1999

[PCR amplification and cloning of the specific region of the gene encoding 83kd antigen from Borrelia burgdorferi].

According to the published gene sequence coding the 83 kd antigen from B31 strain of Borrelia Burgdorferi, we selected the region from 1419 bp to 1896 bp as the target sequence to design a pair of oligonucleotide primers, obtained the gene fragment by using PCR, and recombinant expression vector pBX1 by cloning the gene fragment into plasmid vector pBK-CMV. The recombinant plasmid can be made into nucleic acid probe for the classification of Borrelia burgdorferi. The gene fragment product expressed by pBX1 can be used as antigen in the serological diagnosis of Lyme disease.

Antigens, Bacterial↗
PubMed1999

[Expression of a HCV multi-epitopes antigen gene and study on its immunogenicity].

Due to the hypervariable character of hepatitis C virus (HCV), 5 conserved T and/or B cell epitopes from core, envelope, NS3 and NS5 protein of HCV were chosen to form a 270 bp multi-epitopes antigen gene. The gene was clone into a fusion vector pWR450-1 to express a beta-galactosidase-HCV hybrid protein GZ-PCX. The purified GZ-PCX protein was specifically recognized by human anti-HCV antibodies. These results show that the HCV hybrid multi-epitopes antigen has excellent immunogenicity, which might be able to be used as an effective diagnosis agent and to provide protectivity to any genotype of HCV which might partly solve the problems in the researches of HCV vaccines.

Epitopes↗
PubMed1999

[Finding of new FCC1/HN antigenic expressed sequence tag(ESTs) of Plasmodium falciparum].

AIM: To sequence the strong positive clones obtained by immuno-screening of Plasmodium falciparum FCC1/HN lambda gt11 cDNA expression library, and to elucidate the antigenic expressed sequence tags through sequencing the cDNA insert of these positive clones, and new antigenic ESTs could serve as a resource to pursue their corresponding antigen genes. METHODS: cDNA inserts of positive lambda gt11 phage clones were amplified by PCR. The PCR products, after purification, were cloned into the M13 mp18 sequencing vector. Single-stranded M13 DNA was prepared and sequenced. Then the acquired sequences were compared in homologies with EMBL/GenBank database on the PC/GENE software system and searched in NCBI (National Center for Biotechnology Information) GenBank using BLAST (Basic Local Alignment Search Tool) commond. RESULTS: Sequence C03 was part of the known P. falciparum antigenic heat shock protein 70 (Pfhsp70) gene, while the other 5 sequences were new P. falciparum antigenic expressed sequence tags (ESTs). CONCLUSION: The 5 new antigenic ESTs generated could serve as the breaking through points in our efforts to find out new P. falciparum antigen genes.

Animals↗
PubMed1999

[Determination of circulating antigen in urine of rabbits infected with Schistosoma japonicum].

AIM: To develop an immunoassay for the detection of circulating schistosome antigen (CSA) in host urine. METHODS: CSA extracted from the urine of the rabbits infected with Schistosoma japonicum was used for preparing and selecting specific monoclonal antibody. A one-step dot-ELISA using this specific McAb and a 2nd antibody was used for detection of circulating schistosome antigen in the urine of infected rabbits. RESULTS: No CSA was detected in urine from all of 22 rabbits before infection. The positive rate of CSA in infected rabbits was correlated with the intensity of infection and the time of infection. No CSA was detected in the urine rabbits of 3 weeks after infection with 25 cercariae while the positive rate of CSA in the urine from rabbits infected with 200 cercariae was 40% and 100% after 3 and 6 weeks, respectively. A combination of CSA detection in both urine and serum may increase the detectability. CONCLUSION: The specific McAb prepared by urine CSA of Schistosoma japonicum-infected rabbits can be used as a probe for detecting CSA in the urine of infected rabbits.

Animals↗
PubMed1999

[Establishment and application of dipstick sandwich colloidal dye immunoassay for circulating antigen detection in schistosomiasis patients].

AIM: To set up a simple immunoassay for the detection of circulating antigens in host serum. METHODS: A kind of colloidal pale purple dye (HFRL) used as a staining reagent for immunoassay was first selected from the dyes produced in China and an optimum condition for labelling the dye onto the combined IgM antibodies was explored. A dipstick sandwich colloidal dye immunoassay (DS-DIA) for the detection of circulating antigens in host sera was established. RESULTS: The minimal concentration of SEA detected was 5 ng/ml by DS-DIA. Serum circulating antigen detection in 14 cases of acute schistosomiasis japonica, 113 chronic cases and in 113 healthy controls revealed that the sensitivity was 100% in acute cases, 52.2% in chronic cases and the specificity was 92.9% for uninfected students. The sensitivity and specificity of DIA were similar to those of dot-ELISA. A certain degree of diagnostic complementarity up to 76.1% in sera from these patients was seen when DS-DIA and dot-ELISA were used in paralle. CONCLUSION: DS-DIA is a simple, economical and reliable method for detecting circulating antigens of Schistosoma japonicum, having a wide potential value especially for field use.

Adult↗
PubMed1999

[Sequencing and analysis of a cDNA clone CO111 of Plasmodium falciparum].

AIM: To sequence and analyse a cDNA clone CO111, reacting with immune sera obtained from rabbits immunized with Plasmodium falciparum and one McAb against P. falciparum. METHODS: cDNA clone was amplified by PCR. The PCR product was purified and polished with Klenow enzyme and ligated into the M13mp18 vector (digested by SamI) and then transformed into E. coli JM109. The positive recombinant was screened out by PCR and sequenced by the PRISM Dye Primer Sequencing Kit(ABI). The sequence was analyzed by the program from Geneva University and was compared by GenBank of EMBL. RESULTS: The nucleotide sequence of this cDNA clone contains an open-reading frame of 233 bp, which encodes a predicted polypeptide of 77 amino acid residues. The ratio between A + T and G + C is 3.16. The polypeptide is highly hydrophilic and flexible. Comparison among cDNA of P. falciparum from GenBank of EMBL showed that no sequence identical to this cDNA was found. CONCLUSION: A novel cDNA clone reacted with the antibodies against P. falciparum was isolated.

Amino Acid Sequence↗
PubMed1999

[Experimental study on antitumor activity of the root of Eurphorbia helioscopia in vivo].

Previous studies showed EWE could strongly inhibit the proliferation of tumor cells in vivo. Experimental results also showed that EWE had antitumor effect in S180-bearing mice and H22-bearing mice and prolonged life-span in S180-bearing mice in this paper, Furthermore, it was found that EWE could improve the immune function of S180-bearing mice. Therefore EWE can be considered as a potent antitumor herb.

Animals↗
PubMed1999

[Spectrophotometric determination of iron using eriochrome cyanine R as extractant with phase-separation].

Spectrophotometric determination of iron by using eriochrome cyanine R as extractant and color-developing agent in organic solvents was studied. The complex was extracted by PEG phase from the water solutions of pH4.5-6.5 (NaAc-HAc). The maximum absorption of the complex is at 560 nm and the molar absorptivity is 5.36 x 10(4) L x mol(-1) x cm(-1). Beers law was obeyed in the range of 0-40 microg Fe. Iron and eriochrome cyanine R formed a stable complex with a molar ratio of 1:2. The proposed method has been applied to the determination of copper in aluminium alloys with satisfactory results.

Benzenesulfonates↗
PubMed1998

[Primary study of differentially expressed cDNA sequences in cell line HNE1 of human nasopharyngeal carcinoma by cDNA representational difference analysis].

OBJECTIVE: To search differentially expressed sequences correlated with pathogenesis of human nasopharyngeal carcinoma (NPC), including the candidates of tumor suppressor genes. METHODS: cDNA representational difference analysis (RDA) was performed to isolate differentially expressed sequences between cDNA from normal human primary cultures of nasopharyngeal epithelial cells and cDNA from NPC cell line HNE1. The sources of differentially expressed products were proved by Southern blot and Northern blot. The fragments were cloned with pGEM-T easy kit and sequenced by the chain termination reaction. RESULTS: Four differentially expressed cDNA fragments were isolated in the fourth subtractive hybridization using cDNA from normal human primary cultures of nasopharyngeal epithelial cells as tester amplicon and cDNA from NPC cell line HNE1 as driver amplicon by cDNA RDA. These differential cDNA fragments revealed that they really came from the tester amplicon and were not expressed or down-regulated in the NPC HNE1 cells. Of these obtained clones, some are the fragments of the human known genes including house-keeping genes, the others are novel genes. CONCLUSION: NPC involves alteration of multiple genes. Some of known genes matched with the differentially expressed sequences have an effective suppressive ability on the carcinoma.

Base Sequence↗
PubMed1998

[Establishment of partial gene expression map of 7q32 in nasopharyngeal carcinoma and primary culture normal nasopharyngeal epithelial cells].

OBJECTIVE: To establish partial gene expression map of 7q32 in nasopharyngeal carcinoma (NPC) cell line, tissues and primary culture normal nasopharyngeal epithelial cells. METHODS: We detected the expression of 20 ESTs at 7q32 in NPC cell line HNE1,13 NPC biopsies and primary culture normal nasopharyngeal epithelial cells using differential RT PCR and Northern hybridization. RESULTS: 8 ESTs (AA188181, AA13079,N27556, AA031919, N22721, H20825, T91284, AA001936) expressed equally in both of HNE1 and primary culture normal nasopharyngeal epithelial cells; 7 ESTs (T64215, AA025822, R60014,R80002,H06688, R60192,R95096) expressed in neither of them; 3 ESTs (H19830,W72688,AA130630) overexpressed in HNE1 ; and 2 ESTs (AA070437, H90882) overexpressed in primary culture normal nasopharyngeal epithelial cells. W72688 and H19830 each overexpressed in 77%(10/13) of NPC biopsies; AA070437 down-expressed in 30.7% of NPC biopsies. CONCLUSION: Partial gene expression map of 7q32 in nasopharyngeal carcinoma cell line ,tissues and primary culture normal nasopharyngeal epithelial cells has been established. The up-regulation of W72688, H19830 and down-regulation of AA070437 may be related to the occurrence of NPC.

Blotting, Northern↗