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Jun Luo

Publications and source records attributed to Jun Luo.

At least 37 records · Page 2Linked to original sources
PubMed2005

Peroxisomal branched chain fatty acid beta-oxidation pathway is upregulated in prostate cancer.

Overexpression of alpha-methylacyl-CoA racemase (AMACR), an enzyme involved in branched chain fatty acid beta-oxidation, in prostate cancer has been reported. Here, we report that an enzyme downstream from AMACR in the peroxisomal branched chain fatty acid beta-oxidation pathway-D-bifunctional protein (DBP)-is also upregulated in prostate cancer at both mRNA and protein levels, accompanied by increased enzymatic activity. Furthermore, our data suggest that pristanoyl-CoA oxidase (ACOX3), which is expressed at extremely low level in other human organs studied including the liver, might contribute significantly to peroxisomal branched chain fatty acid beta-oxidation in human prostate tissue and some prostate cancer cell lines. In contrast to these results for peroxisomal enzymes, no significant expression changes of mitochondrial fatty acid beta-oxidation enzymes were observed in prostate cancer tissues through comprehensive quantitative RT-PCR screening. These data for the first time provide evidence for the selective over-activation of peroxisomal branched chain fatty acid beta-oxidation in prostate cancer, emphasizing a new metabolic change during prostate oncogenesis.

17-Hydroxysteroid Dehydrogenases↗
PubMed2005

Identification of 20 snoRNA-like RNAs from the primitive eukaryote, Giardia lamblia.

From a specialized cDNA library of Giardia lamblia, 20 snoRNA-like RNAs, including 16 box C/D sRNAs and four box H/ACA sRNAs, were first identified. The sRNAs were predicted to guide a total of 11 2'-O-methylation and four pseudouridylation sites on the G. lamblia rRNAs, respectively. By using primer extension assay, seven methylation sites were precisely mapped in the G. lamblia 16S rRNA, despite its high GC content. All of the sRNA genes locate on the small intergenic regions of the G. lamblia genome and seem to be independently transcribed from their own promoters. Particularly, a cluster composed of GlsR17 and GlsR18 genes is transcribed as a dicistronic precursor, implying a mechanism of endonuclease cleavage for the maturation of the two sRNAs. The systematic identification of the sRNAs in G. lamblia has provided valuable information about the characteristics of the two major families of small guide RNAs in one of the most primitive eukaryotes and would contribute to the understanding of the evolution of small non-messenger RNA genes from prokaryotes to eukaryotes.

Animals↗
PubMed2005

Persistence of marrow stromal cells implanted into acutely infarcted myocardium: observations in a xenotransplant model.

OBJECTIVE: It has been reported that unmatched adult bone marrow stromal cells could be tolerated by immune-competent allotransplant or xenotransplant recipients under various conditions. This study examined whether xenogeneic bone marrow stromal cells implanted immediately after myocardial infarction can survive and differentiate, attenuating deterioration in left ventricular function. METHODS: In groups I and II (n = 34), myocardial infarctions were created in immunocompetent adult Lewis rats by proximal left coronary artery ligation. In group I, 3 x 10(6)lacZ-labeled mouse bone marrow stromal cells were immediately injected into the peri-infarct area of the left ventricle, whereas in group II, only culture medium was injected. There were 10 early and 4 late deaths. At 4 weeks after injection, hearts were stained for beta-galactosidase and troponin IC. In groups IIIA and IIIB, lacZ-labeled mouse skin fibroblasts were implanted into rat myocardium (n = 10 each) with and without left coronary artery ligation, respectively, and the rats were killed serially. In group IV, animals underwent sham surgery (n = 5, no deaths). At 4 weeks, surviving rats in groups I, II, and IV (n = 10, n = 10, and n = 5, respectively) underwent blinded transthoracic echocardiography for ventricular function studies. RESULTS: In group I, labeled mouse-derived bone marrow stromal cells were found within rat myocardium that stained positively for troponin IC 4 weeks after implantation. Functionally, mean left ventricular ejection fraction (P = .007), stroke volume (P = .03), and fractional shortening (P = .02) were all significantly higher in group I than in group II. In groups IIIA and IIIB, mouse fibroblasts induced cellular infiltration with rapid loss of donor cells. No labeled cells were found after 4 days. In group IV, there was no change in cardiac function. CONCLUSION: Xenogeneic bone marrow stromal cells implanted into acutely ischemic myocardium induced by coronary artery ligation were immunologically tolerated, survived and differentiated, resulting in a cardiac chimera which improved left ventricular function. This unique immunologic tolerance may suggest the feasibility of using bone marrow stromal cells as universal donor cells.

Animals↗
PubMed2005

[Relation between the expression of hypoxia inducible factor-1alpha and angiogenesis in ovarian cancer using tissue microarray].

OBJECTIVE: To study the relation between the expression of hypoxia inducible factor-1alpha (HIF-1alpha)and angiogenesis in ovarian cancer. METHODS: The expressions of HIF-1alpha mRNA, vascular endothelial growth factor (VEGF), and CD(34) in 295 patients with epithelial ovarian tumors were analyzed by tissue microarray technology, in situ hybridization and immunohistochemistry, and compared with those of 13 normal ovarian tissue samples. RESULTS: The expressions of HIF-1alpha mRNA were observed in 0, 13.2%, 42.1% and 81.9% of normal ovarian tissue, benign, borderline and malignant ovarian tumors respectively. Expression rates of HIF-1alpha mRNA in borderline and invasive tumors were significantly higher than those in normal ovarian tissues and benign tumors (P < 0.01). Statistical analysis revealed that the expression of HIF-1alpha mRNA was not related to surgical stages and histological subtypes. Close positive relation was observed between the expression of HIF-1alpha mRNA and tumor histological grade (r = 0.246, P < 0.01). There were significant correlations between the expression of HIF-1alpha mRNA and VEGF (r = 0.206, P = 0.01) and microvessel density (MVD) level (r = 0.451, P < 0.01). CONCLUSION: HIF-1alpha may play a role in angiogenesis of ovarian carcinoma, and may promote the development of the carcinoma.

Adenocarcinoma↗
PubMed2005

[Effects of selenoprotein on blood glucose, Ca2+ transfer and NO system in diabetic mice].

OBJECTIVE: To study the controlling effect of selenoprotein on blood glucose, Ca2+ transfer and NO system in diabetic mice. METHODS: Male Kunming mice of (20.3 +/- 1.7) g body weight were injected 200 mg/kg bw, 2% alloxan in abdomen to make diabetic model (DM), and were randomly divided into six groups: normal control group (I), normal + selenoprotein group(Se 100 microg/kg bw) (lI), DM control group (III), DM + lower dose selenoprotein group(Se 100 microg/kg bw) (IV), DM + higher dose selenoprotein group (Se 300 microg/kg bw) (V), DM + Na2SeO3 group (Se 100 microg/kg bw) (VI). RESULTS: The level of blood glucose in V group [(20.4 +/- 6.3 mmol/L] were significantly lower than lII group(45.3 +/- 3.3) mmol/L P < 0.05. The activity of Ca(2+) -ATPase of kidney in V group (0.90 +/- 0.5 micromol/ (h x mg prot) is significantly higher than III group [(0.35 +/- 0.1) micromol/(h x mg prot)] (P < 0.05, and the activity of NOS in V group [(25.0 +/- 4.3) U/ml] is significantly lower than III group [(35.2 +/- 4.4) U/ml] (P < 0.05). CONCLUSION: Selenoprotein that supplemented selenium doseis 300 microg Se/kg weight could significantly decrease blood glucose, increase the activities of Ca(2+) -ATPase on kidney and weaken the activities of plasma NOS in diabetic mice.

Animals↗
PubMed2005

[Reasonable applications of automatic exposure control in computed radiography].

This paper is to explore the reasonable applications of automatic exposure control in computed radiography, and to improve the quality of CR images. It is very important to select a suitable KV value in automatic exposure control in computed radiography. At the same time, a suitable ionization chamber, correct density compensation and necesary post-processing should be selected.

Adolescent↗
PubMed2005

[Polymorphism Analysis of the CSN1S2 Gene Digested.].

PCR-RFLP was applied to analyze the polymorphism of CSN1S2 gene in 170 goats that comprised of five goat breeds, namely Xinong Saanen dairy goat, Guanzhong dairy goat, Shaannan white goat, Angora goat and Boer goat. A 310 bp -long PCR product was digested with Alw26I and demonstrated polymorphism in five goat populations that were all at Hardy-Weinberg equilibrium (P>0.05). For Xinong Saanen dairy goat, Guanzhong dairy goat, Shaannan white goat, Angora goat and Boer goat, gene heterozygosity/effective allele gene number/Shaanon information entropy /Polymorphism information content were 0.1589/1.1889/0.2955/0.1463, 0.4114/1.6981/0.6017/0.5171, 0.1653/1.1980/0.3046/0.1516, 0646/1.0691/0.1463/ 0.0625, 0.0541/1.0572/0.1270/ 0.0526, respectively. According to the heredity diversity indexes described above of the five goat breeds, Guanzhong dairy goat had the most abundant heredity diversity and showed high polymorphism, and Xinong Saanen dairy goat and Shaannan white goat were inferior, while Angora goat and Boer goat had the lowest genetic variability.

Alleles↗
PubMed2004

Trefoil factor 3 overexpression in prostatic carcinoma: prognostic importance using tissue microarrays.

BACKGROUND: Human intestinal trefoil factor 3 (TFF3) is a member of a family of polypeptides encoded by a cluster of genes on chromosome 21. Through gene expression profiling studies TFF3 mRNA has been found to be overexpressed in prostate cancer. METHODS: We used immunochemistry on tissue microarrays and software tools, collectively referred to as TMAJ, for online assessment of staining to analyze samples from 294 primary tumors and 61 metastatic lesions. RESULTS: Applying a cutoff of 20% of cells staining as positive, the frequency of staining was 18.8% in normal (51 of 272) and 47.0% in primary tumors (126 of 268), P < 0.0001, Wilcoxon rank sum). Expression of TFF3 in metastatic prostate cancer was similar to that in primary tumors. TFF3 expression was not associated with time to biochemical recurrence, development of distant metastasis, or death due to prostate cancer. Scoring data derived from visual estimation of expression correlated highly with semi-automated image analysis using the Automated Cellular Imaging System (ACIS) from Chromavision, Inc. CONCLUSIONS: These studies validate that TFF3 is overexpressed at the protein level in a subset of primary and metastatic prostate cancers, show the first use of the TMAJ database, and demonstrate the ability to semi-automatically scan and score immunohistochemically stained tissue microarray slides.

Biomarkers, Tumor↗
PubMed2004

Catena-poly[[bis(1H-benzotriazole-kappaN3)cobalt(II)]-di-mu-tricyanomethanido-kappa2N:N'] and catena-poly[[bis(3,5-dimethyl-1H-pyrazole-kappaN2)manganese(II)]-di-mu-tricyanomethanido-kappa2N:N'].

Two new one-dimensional coordination polymers, viz. the title compounds, [Co[C(CN)(3)](2)(C(6)H(5)N(3))(2)](n), (I), and [Mn[C(CN)(3)](2)(C(5)H(8)N(2))(2)](n), (II), have been synthesized and characterized by X-ray diffraction. Both complexes consist of linear chains with double 1,5-tricyanomethanide bridges between neighbouring divalent metal ions. The Co and Mn atoms are located on centres of inversion. In (I), the coordination environment of the Co(II) atom is that of an elongated octahedron. The Co(II) atom is coordinated in the equatorial plane by four nitrile N atoms of four bridging tricyanomethanide ions, with Co-N distances of 2.106 (2) and 2.110 (2) A, and in the apical positions by two N atoms from the benzotriazole ligands, with a Co-N distance of 2.149 (2) A. The [Co[C(CN)(3)](2)(C(6)H(5)N(3))(2)] units form infinite chains extending along the a axis. These chains are crosslinked via a hydrogen bond between the uncoordinated nitrile N atom of a tricyanomethanide anion and the H atom on the uncoordinated N atom of a benzotriazole ligand from an adjacent chain, thus forming a three-dimensional network structure. In (II), the Mn(II) atom also adopts a slightly distorted octahedral geometry, with four nitrile N atoms of tricyanomethanide ligands [Mn-N = 2.226 (2) and 2.227 (2) A] in equatorial positions and two N atoms of the monodentate 3,5-dimethylpyrazole ligands [Mn-N = 2.231 (2) A] in the axial sites. In (II), one-dimensional polymeric chains extending along the b axis are formed, with tricyanomethanide anions acting as bidentate bridging ligands. A hydrogen bond between the uncoordinated nitrile N atom of the tricyanomethanide ligand and the H atom on the uncoordinated N atom of a 3,5-dimethylpyrazole group from a neighbouring chain links the molecule into a two-dimensional layered structure.

Journal Article↗
PubMed2004

Design of a compact disk-like microfluidic platform for enzyme-linked immunosorbent assay.

This paper presents an integrated microfluidic device on a compact disk (CD) that performs an enzyme-linked immunosorbent assay (ELISA) for rat IgG from a hybridoma cell culture. Centrifugal and capillary forces were used to control the flow sequence of different solutions involved in the ELISA process. The microfluidic device was fabricated on a plastic CD. Each step of the ELISA process was carried out automatically by controlling the rotation speed of the CD. The work on analysis of rat IgG from hybridoma culture showed that the microchip-based ELISA has the same detection range as the conventional method on the 96-well microtiter plate but has advantages such as less reagent consumption and shorter assay time over the conventional method.

Animals↗
PubMed2004

Identification of aryl hydrocarbon receptor as a putative Wnt/beta-catenin pathway target gene in prostate cancer cells.

Recent genetic and functional analyses have implicated the wnt/beta-catenin signaling pathway in prostate cancer (CaP) pathogenesis. Thus, there is much interest in understanding the consequences of wnt signaling in CaP; target gene expression is one important area of inquiry and is the focus of this report. Adenoviral-mediated overexpression of a mutant, hyperactive form of beta-catenin in CWR22-Rv1 CaP cells led to increased aryl hydrocarbon receptor (AhR, or dioxin receptor) and transmembrane protein 2 RNA transcript expression, as detected by cDNA-microarray analyses. Validating these results, reverse transcription-PCR assays demonstrated that in CWR22-Rv1 cells as well as in LAPC-4 CaP cells, increased putative target gene RNA expression occurs with transient overexpression of mutant beta-catenin, treatment of cells with lithium chloride, or with wnt3a-conditioned medium, three distinct modes of experimental wnt/beta-catenin pathway activation. This beta-catenin-associated expression of AhR and transmembrane protein 2 does not require de novo protein synthesis and may only involve a certain subset of CaP cell lines. Western and immunofluorescence analyses were undertaken to assess the relationship between the wnt/beta-catenin-stimulated increase in AhR transcripts and AhR protein expression; we provide evidence that an association exists whereby up-regulation of AhR RNA by wnt or beta-catenin is coupled with augmented AhR protein levels. Intriguingly, these studies also demonstrated that nuclear beta-catenin staining may not be a sole deciding factor when predicting the status of wnt/beta-catenin signaling in CaP cells. Finally, the extent to which wnt signaling may synergize with an environmental agonist of AhR (2,3,7,8-tetrachlorodibenzo-p-dioxin) to potentiate AhR transcriptional activity was examined. Considering previous work linking AhR to processes of development and carcinogenesis, our data may highlight one particular role for wnt/beta-catenin signaling in prostate tumor biology.

Animals↗
PubMed2004

[Changes in neural cell adhesion molecule mRNA expression and protein level in the CA1 region of the hippocampus during long term potentiation induction and maintenance].

It has been demonstrated that neural cell adhesion molecule (NCAM) is critical for the induction and maintenance of long term potentiation (LTP) in the CA1 region of rat hippocampus. In the present study, we investigated the changes in NCAM mRNA expression and NCAM protein level after the induction of LTP in vitro using the techniques of in situ hybridization and Western blot. The results showed that the number of NCAM mRNA positive labelled neurons significantly increased (76.6+/-11.5 neurons) 10 min after tetanus when the slope of fEPSP markedly increased. The level of NCAM protein also increased significantly (7.190+/-0.64 arbitrary unit/50 microg protein) 10 min after tetanus. The number of NCAM mRNA positive labelled neurons no longer changed (73.3+/-14.0) 1 h after tetanus, however, the NCAM protein level (9.031+/-0.71) at 1 h after tetanus was higher than that at 10 min after tetanus. Moreover, the NMDA receptor inhibitor AP-5, which blocked LTP, prevented the increase in NCAM mRNA expression and NCAM protein level. The results demonstrate that NCAM mRNA expression maintains a high level, whereas NCAM protein changes from a low level to a high level during induction and maintenance of LTP.

Animals↗
PubMed2004

Expression of nuclear factor-kappa B and target genes in gastric precancerous lesions and adenocarcinoma: association with Helicobactor pylori cagA (+) infection.

AIM: To examine the expression of nuclear factor kappaB (NF-kappaB) and its target genes in intestinal metaplasia (IM), dysplasia (DYS) and gastric carcinoma (GC) infected with Helicobacter pylori (H pylori) and to investigate the mechanism underlying H pylori cytotoxin associated gene A (cag A) infection leading to gastric adenocarcinoma. METHODS: Expressions of NF-kappaB/p65 and its target genes: c-myc, cyclinD1 and bcl-xl were immunohistochemically examined in 289 cases of gastric biopsy and resection specimens from patients with IM, DYS and GC infected with H pylori. H pylori in the above mentioned tissues was detected by Warthin-Starry stain and rapid urease tests. IgG antibody to cagA in sera of the patients was measured by ELISA. RESULTS: The positive rates of NF-kappaB/p65 were significantly higher in groups with cagA of IMI-II(28/33), IM III(48/52), DYSI(27/31), DYS II-III(28/32), GC(35/40) than in groups without cagA of IMI-II(4/17), IMIII(3/20), DYSI(3/20), DYSII-III(6/21), GC(10/23). The expressions of c-myc, cyclinD1, and bcl-xl were significantly higher in groups with cagA of IM III(47/52, 49/52, 46/52), DYSII-III(29/32, 26/32, 25/32) than in groups without cagA of IM III(8/20, 7/20, 5/20), DYSII-III(10/21, 8/21, 3/21), which were in conformity with the expression of NF-kappaB in IM III, and DYSII-III. A significantly higher expression level of NF-kappaB/p65, c-myc, cyclinD1 and bcl-xl was detected in intestinal type GC(27/28, 18/28, 22/28, 24/28) than in diffuse type GC(8/12, 3/12, 3/12, 6/12), respectively. CONCLUSION: There may be two different molecular mechanisms in the occurrence of intestinal and diffuse type gastric carcinomas. Intestinal type gastric carcinoma is strongly associated with high expression of c-myc, cyclinD1 and bcl-xl through NF-kappaB/p65 activated by H pylori cagA. Inhibiting the activity of NF-kappaB is an effective and promising way to prevent intestinal type gastric carcinoma.

Adenocarcinoma↗
PubMed2004

Preparation of both antipodes of enantiopure inherently chiral calix[4]crowns.

Both antipodes of enantiopure inherently chiral calix[4]crown derivatives were successfully obtained through separation of their BINOL diastereomeric derivatives of corresponding racemates using preparative TLC instead of conventional HPLC methods. Such a result provides a basis for future study of chiral recognition and asymmetric catalysis with inherently chiral calixrene derivatives.

Journal Article↗
PubMed2004

A fibrous-bed bioreactor for continuous production of monoclonal antibody by hybridoma.

A fibrous-bed bioreactor (FBB) has been developed to culture hybridoma cells for long-term continuous production of monoclonal antibody (MAb). A non-woven polyester fibrous matrix was used to immobilize the cells to reach a high viable cell density of 3 x 10(8) cells cm(-3) packed bed, which gave a high volumetric MAb productivity of 1 g L(-1) day(-1) under continuous feed conditions with the medium containing 10% serum. Reducing the medium serum content to 1% increased MAb production to 6.5 g L(-1) day(-1) in a repeated batch FBB culture. MAb production was higher at higher dissolved oxygen (DO) levels in the range between 10% and 70% of air saturation, although DO did not significantly affect glucose metabolism and lactate production. The medium LDH (lactate dehydrogenase) level increased dramatically when the DO level was decreased from 30% to 10%, suggesting that a critical DO level of approximately 30% is necessary for maintaining the FBB culture for long-term operation. Compared with suspension cultures in T-flasks and spinner flasks, the FBB culture had a lower lactate yield from glucose (0.80 vs. 0.91 g g(-1), produced MAb at a higher concentration (up to 442 mg L(-1) vs. 83.5 mg L(-1), and was stable for continuous long-term operation (more than 1 month). The superior FBB performance was attributed to the highly porous fibrous matrix that enabled the efficient mass transfer, cell immobilization, and continued growth and regeneration that are critical to maintaining a high density of viable and productive cell populations. The cells immobilized in the fibrous matrix had high viability (>85%) even though many of them were in growth arrest (G1/G0 phase) as indicated by their smaller cell size (<10 microm). Scanning electron microscopic studies of the cell-matrix showed that the high density of cells formed large clumps within the interstitial spaces of the fibrous matrix. Their close contact and interaction with each other might have contributed to their ability to survive well under adverse conditions such as low DO and low serum content in the medium. It was also found that the cells present inside the fibrous matrix had a higher viability and lower apoptosis than those present in the liquid suspension, indicating that the fibrous matrix had selectively retained healthy, nonapoptotic cells and dislodged apoptotic and dead cells; this also might have contributed to the stability of the long-term culture. This work demonstrated that the FBB originally developed for microbial fermentation also gave excellent results in achieving high cell density, productivity, and product concentrations, and should have a good potential for industrial animal cell culture applications.

Antibodies, Monoclonal↗