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Biomedical subjects

Jun Luo

Publications and source records attributed to Jun Luo.

At least 55 records · Page 3Linked to original sources
PubMed2004

Prostate cancer detection on urinalysis for alpha methylacyl coenzyme a racemase protein.

PURPOSE: We assessed the feasibility of a novel urinary test for prostate cancer based on the presence of alpha methylacyl coenzyme A racemase (AMACR) protein in voided urine specimens obtained after prostate biopsy. MATERIALS AND METHODS: Clean catch voided urine specimens were prospectively collected from 26 consecutive men immediately after transrectal ultrasound guided prostate biopsy for suspected malignancy. The presence of AMACR was evaluated in a blinded manner by Western blot analysis and correlated with biopsy results and patient clinical information. RESULTS: AMACR was detected in the urine in 18 of 26 patients (69%). AMACR was detected in all 12 patients with biopsy confirmed adenocarcinoma of the prostate (100% sensitivity, 95% CI 75 to 100), in 5 of 12 with no evidence of cancer on biopsy (58% specificity, 95% CI 29 to 78) and in 1 of 2 (50%, 95% CI 3 to 80) with atypia on biopsy. Overall AMACR detection was associated with cancer status by prostate biopsy in 21 of 26 patients (86%). CONCLUSIONS: We report the feasibility of a novel, noninvasive, nonprostate specific antigen based molecular approach to detect prostate cancer in voided urine. To our knowledge this is the first report of AMACR protein detection in the urine of patients with prostate cancer. A screening test based on urinary AMACR may develop into a useful adjunct to serum prostate specific antigen and digital rectal examination for identifying men at increased risk for harboring prostate cancer despite negative biopsy. Such a test has potential application for stratifying patients into low and high risk groups for surveillance vs repeat biopsy.

Acyl Coenzyme A↗
PubMed2004

[Development and application of geographic information system of Aedes vector in Chaozhou city, Guangdong province].

OBJECTIVE: To explore the spatial distribution character of dengue fever and the change of Aedes' population, so as to provide macroscopical decision-making evidences of prevention and supervision on dengue fever. METHODS: (1) Collecting data on morbidity of dengue and supervision on vector's population in the corresponding period. (2) Drawing digitized map of Chaozhou in scale of 1:50,000, including elements of boundary, residential areas, road and traffic, altitude, water systems etc. (3) Measuring the latitude and longitude of center position of surveillance safes on the scene. (4) Processing spatial analysis by the ArcGIS 8.5 software. RESULTS: Distribution of Aedes showed spatial cluster in Chaozhou, while its density was related to the distance to the watersides. The closer to the watersides, the higher the density was. Map on spatial distribution showed that although the Aedes epidemic situation changed yearly, but primarily be kept in high, middle, low regions. Cross-validation effects of the distribution maps were satisfactory. CONCLUSION: Geographic information system was promising in analyzing data on dengue fever, and better than other routine research methods.

Aedes↗
PubMed2004

[Study on the influence of medical abortion and surgical abortion on subsequent pregnancy].

OBJECTIVE: To evaluate and compare medical abortion versus surgical abortion in respect of their influence on the safety of the mother and baby in the subsequent pregnancy and parturition. METHODS: Based on the principle of informed consent of subjects, 150 healthy pregnant women with a past history of having experienced medical abortion once were included in the study group (also called medical abortion group), and in the same period, 150 healthy pregnant women with a past history of having experienced surgical abortion once were enrolled into the comparison group (also called surgical abortion group). From then on, all the pregnant women in the two groups were followed up till a week after labor. The baseline data of the two groups were comparable (P>0.05). The rates of complications observed in these women during pregnancy and labor were evaluated. RESULTS: The incidence rates of miscarriage, placental abnormality, premature delivery and postpartum hemorrhage in the study group were significantly lower than those in the comparison group (P<0.05). No significant differences on other variables were observed between the two groups. CONCLUSION: Medical abortion is probably safer than surgical abortion in respect of their influence on subsequent pregnancy. So, provided there is less contraindication, medical abortion may be the choice for terminating unwanted pregnancy, especially for those women without a child.

Abortifacient Agents↗
PubMed2004

[CML cell line K562 cell apoptosis induced by mangiferin].

This study was aimed to investigate the effects and the mechanism of mangiferin on chronic myeloid leukemia cell lines K562 cells in vitro. The antiproliferation effects of mangiferin on K562 leukemia cells were tested by tetrazolium salt (MTT) method; the apoptosis induced by mangiferin on K562 cell line was explored by means of cell morphology, DNA gel electrophoresis and flow cytometry. The changes in bcr/abl gene expression was detected by using reverse transcriptase (RT)-PCR. The results showed that five different concentrations of mangiferin (25 - 200 micromol/L) dose-dependently and time-dependently inhibited the proliferation of K562 cells, and induced apoptosis in K562 cell line. RT-PCR revealed that bcr/abl gene expression was down-regulated when K562 cells had been treated with different concentrations of mangiferin. In conclusion, mangiferin remarkably inhibits the proliferation of K562 leukemia cells in vitro, and induces apoptosis in K562 cell line probably through down-regulation of bcr/abl gene expression.

Apoptosis↗
PubMed2004

[Expression of NFkappaB p65 and its target genes in gastric cancer and precancerous lesions].

OBJECTIVE: To study the expression of NFkappaB p65 and its target genes in intestinal metaplasia (IM), dysplasia (Dys), gastric cancer (GC) infected with Helicobacter pylori (Hp) and explore the mechanism of infection by cytotoxin-associated antigen A expressing Hp (CagA(+)Hp) in the development of gastric cancer. METHODS: CagA antibody in blood sample of 289 patients was determined by ELISA. Hp was detected by rapid urease test and Warthin starry staining. Expression of NFkappaB p65 and its target genes in IM, Dys and GC was examined by immunohistochemistry. RESULTS: In IMI approximately II, IMIII, DysI, DysII approximately III and GC, the expression of NFkappaB p65 was significantly higher in patients with CagA(+)Hp infection than those without CagA Hp infection. In IMIII and DysII approximately III, the expression of NFkappaB p65, c-myc, CyclinD(1) and bcl-xl was significantly higher in patients with CagA Hp infection than those without CagA Hp infection. In gastric cancer infected with CagA(+)Hp, the expression of NFkappaB p65, c-myc, CyclinD(1) and bcl-xl was significantly higher in intestinal type than in diffuse type. CONCLUSION: There are different mechanisms in intestinal type and diffuse type in the development of gastric cancer. The occurrence of intestinal type gastric cancer is associated with CagA(+)Hp infection which by NFkappaB p65 upregulating the expression of c-myc, CyclinD(1),bcl-xl in patients with IMIII, DysII approximately III. It may be an effective method to prevent gastric cancer by inhibiting NFkappaB p65.

Adult↗
PubMed2004

[Detection of the Salmonella invasion gene invA using molecular beacon probe].

OBJECTIVE: To detect Salmonella invasion gene invA. METHODS: The invA gene of Salmonella was amplified with PCR reaction system containing the molecular beacon probe labeled with 6-carboxy fluorescein (6-FAM) at its 5' end and with (4-dimethylaminophenylazo)benzoic acid (DABCYL) at its 3' end, and the fluorescence signal was read at the end of PCR. RESULTS: The fluorescence values of S.enteritidis, S. paratyphi A, S. paratyphi B, S.typhi antigen H, S.typhi, and enteroinvasive E.coli were 161.6, 104.5, 85.9, 83.1, 94.8 and 46.1 respectively. The results of PCR of Salmonella was consistent with that of agarose gel electrophoresis. CONCLUSION: PCR with fluorogenic molecular beacon probe is rapid, specific, sensitive, and convenient for detecting Salmonella with invA gene.

Bacterial Proteins↗
PubMed2003

[Relationship between hippocampal long term potentiation induction and activity of 26S proteasome].

The present study examined the changes in 26S proteasome activity and the signal molecule mechanism regulating 26S proteasome activity in long term potentiation (LTP) in rat hippocampal slices. The results are as follows: 26S proteasome activity was 190+/-14.3 cpm/(100 microg.2 h) before tetanus, a significant increase in 26S proteasome activity (273+/-18.3 cpm/(100 microg.2 h) was found 10 min after tetanus, when the slope of fEPSP was markedly increased. Interestingly, 26S proteasome activity returned to baseline level (210+/-12.8 cpm/(100 microg.2 h) 60 min after tetanus. Moreover, the N-methyl-D-aspartate (NMDA) receptor inhibitor AP-5, which blocked LTP, prevented the increase in the 26S proteasome activity. The results suggest that NMDA receptors contribute to the transient increase in 26S proteasome activity during induction of LTP in the hippocampal CA1 region.

Animals↗
PubMed2003

Di-mu-cyanato-bis[(cyanato-kappaN)(tetramethylethylenediamine-kappa2N,N')copper(II)] and catena-poly[[mu3-cyanato-kappa3O:N:N-bis[(cyanato-kappaN)(1,3-diaminopropane-kappa2N,N')copper(II)]]-mu3-cyanato-kappa3N:N:O].

The two title Cu(II) complexes, [Cu(2)(NCO)(4)(tmeda)(2)] (tmeda is tetramethylethylenediamine, C(6)H(16)N(2)), (I), and [Cu(NCO)(2)(pn)](n) (pn is 1,3-diaminopropane, C(3)H(10)N(2)), (II), have been synthesized and their crystal structures determined. In (I), which lies about an inversion centre, each Cu centre possesses a distorted tetragonal-pyramidal geometry with four basal N atoms from two cyanate anions [Cu-N = 1.945 (2) and 1.948 (3) A] and one tmeda molecule [Cu-N = 2.053 (2) and 2.071 (2) A], and one axial O atom [Cu-O = 2.737 (3) A] from another cyanate anion. The two neighbouring Cu atoms in (I) are joined by a pair of cyanates in an end-to-end fashion, forming a dimer. In (II), each Cu centre adopts a distorted square-bipyramidal geometry, with four equatorial N atoms from two cyanates [Cu-N = 1.988 (2) and 2.007 (3) A] and a pn ligand [Cu-N = 1.996 (3) and 2.011 (3) A], and one apical N atom [Cu-N = 2.437 (3) A] and an apical O atom [Cu-O = 2.900 (3) A] from two cyanates. In contrast with (I), the two neighbouring Cu atoms in (II) are bridged by two cyanates in an end-on fashion, to form a centrosymmetric dimeric unit. These units are further crosslinked, forming a two-dimensional network structure, via weak interactions between the bridging cyanate O atom and a neighbouring Cu atom, plus interactions of the amine H atoms with the cyanate O atoms and the terminal cyanate N atom.

Journal Article↗
PubMed2003

Alpha-methylacyl-CoA racemase as an androgen-independent growth modifier in prostate cancer.

Alpha-methylacyl-CoA racemase (AMACR) is an enzyme involved in beta-oxidation of branched-chain fatty acids and bile acid intermediates. Recent work has identified AMACR as a new diagnostic marker for prostate cancer (PCa). The data from the present study suggest that AMACR is also functionally important for the growth of PCa cells. Overexpressed AMACR from both clinical tissues and PCa cell lines is wild type by sequence analysis and functionally active by enzymatic assay. Correspondingly, enzyme activity of AMACR increases approximately 4-fold in PCa in comparison with adjacent normal prostate. Small interference RNA (siRNA) against AMACR, but not the control inverted siRNA, reduced the expression of AMACR and significantly impaired proliferation of the androgen-responsive PCa cell line LAPC-4. No effect was observed in HeLaS3 cells, which express AMACR at a low level. Cell cycle analyses revealed a G(2)-M cell cycle arrest in LAPC-4 cells treated with siRNA compared with mock treatment or control inverted siRNA. Expression of a siRNA-resistant form of AMACR in LAPC-4 cells protects the cells from growth arrest after AMACR-specific siRNA treatment. Data from Western blotting and luciferase-based reporter assays suggest that the function and expression of AMACR are independent of androgen receptor-mediated signaling. Moreover, simultaneous inhibition of both the AMACR pathway by siRNA and androgen signaling by means of androgen withdrawal or antiandrogen suppressed the growth of LAPC-4 cells to a greater extent than either treatment alone. Taken together, these data suggest that AMACR is essential for optimal growth of PCa cells in vitro and that this enzyme has the potential to be a complementary target with androgen ablation in PCa treatment.

Androgen Antagonists↗
PubMed2003

Decreased gene expression of steroid 5 alpha-reductase 2 in human prostate cancer: implications for finasteride therapy of prostate carcinoma.

BACKGROUND: Steroid 5alpha-reductase 2 (SRD5A2) catalyzes the conversion of testosterone to the more potent androgen, DHT, in the prostate. The therapeutic influence of SRD5A2 inhibitor finasteride on prostate cancer is currently unknown. The direction and extent of changes in SRD5A2 expression in disease tissues is a relevant issue in this regard. METHODS: The expression differences of SRD5A2 in tissues representative of normal, benign, and malignant growth in the human prostate were examined in parallel by comparative analysis of relevant microarray gene expression data. Semiquantitative RT-PCR was used to further verify the gene expression differences of SRD5A2. RESULTS: Consistently decreased expression of SRD5A2 was observed in 25 prostate cancer samples when compared to 25 matched normal samples and nine BPH samples. Expression differences among these samples for six other genes were presented in parallel as indicators of the direction and extent of expression changes. These additional genes include SRD5A1, Hepsin (overexpressed in prostate cancer), AMACR (overexpressed in prostate cancer), Keratin 8 (epithelial marker), smooth muscle actin (stromal marker), Nell2 (overexpressed in BPH). Semiquantitative RT-PCR verified the expression differences for SRD5A2 in six normal, six BPH, and six prostate cancer samples. CONCLUSIONS: Results from this study, combined with those from previous studies, indicate an association of prostate cancer with reduced 5alpha-reductase enzymatic activity as a result of remarkably decreased expression of the SRD5A2 gene. The implications of this study for finasteride therapy of prostate cancer are discussed.

Case-Control Studies↗
PubMed2003

Bis(dicyanamido)(diethylenetriamine-kappa(3)N)copper(II) and (dicyanamido)(triethylenetetramine-kappa(4)N)copper(II) dicyanamide.

Two new complexes, [Cu(C(2)N(3))(2)(dien)] (dien is diethylenetriamine, C(4)H(13)N(3)), (I), and [Cu(C(2)N(3))(trien)](C(2)N(3)) (trien is triethylenetetramine, C(6)H(18)N(4)), (II), have been characterized by single-crystal X-ray diffraction. Both complexes display a distorted tetragonal-pyramidal geometry. In (I), the Cu atom is coordinated in the basal plane by three diethylenetriamine N atoms [Cu-N = 2.000 (2), 2.004 (2) and 2.025 (2) A] and one terminal N atom [Cu-N = 1.974 (2) A] from one monodentate dicyanamide group, and in the apical position by one terminal N atom [Cu-N = 2.280 (2) A] from the other monodentate dicyanamide group. In (II), the Cu atom is surrounded by four triethylenetetramine N atoms [Cu-N = 2.012 (2), 2.014 (2), 2.019 (2) and 2.031 (2) A in the basal plane] and a terminal N atom [Cu-N = 2.130 (2) A in the apical site] from one monodentate dicyanamide group. The other dicyanamide anion is not directly coordinated to the metal atom. In both (I) and (II), hydrogen-bond interactions between the uncoordinated terminal N atoms of two dicyanamide ions and the amine H atoms lead to the formation of three-dimensional networks.

Journal Article↗
PubMed2003

New experimental limit on the photon rest mass with a rotating torsion balance.

A rotating torsion balance method is used to detect the product of the photon mass squared and the ambient cosmic vector potential A(e). The signal is modulated by rotating the torsion balance to ensure the effectiveness of detection for all possible orientations of the vector potential. The influences of sidereal disturbances of environment are also removed by virtue of this modulation method. The experimental result shows micro (2)(gamma)A(e)<1.1 x 10(-11) T m/m(2), with micro (-1)(gamma) as the characteristic length associated with photon mass. If the ambient cosmic vector potential A(e) is 10(12) T m due to cluster level fields, we obtain a new upper limit on photon mass of 1.2 x 10(-51) g.

Journal Article↗
PubMed2003

The collagenolytic effects of the traditional Chinese medicine preparation, Han-Dan-Gan-Le, contribute to reversal of chemical-induced liver fibrosis in rats.

Han-Dan-Gan-Le (HDGL), a Chinese herb preparation composed of Stephaniat tetrandra, Salvia miltorrhiza, Radix paeoniae, Astragalus membranaceus, and Ginkgo biloba, has been used to treat human liver fibrosis. This study was designed to examine the therapeutic effect of HDGL on chemical-induced liver fibrosis in adult Wistar rats. Liver fibrosis was produced in rats by carbon tetrachloride (1.2 ml CCl(4)/kg, 2 times/week, after an initial dose of 5.0 ml CCl(4)/kg, sc), plus a diet of 20% fat, 0.05% cholesterol (continuous) and 30% alcohol in the drinking water ad libitum (every other day) for 8 weeks. HDGL (0.5 and 1.0 g/kg, ig, daily for 6 weeks) was administered to rats 72 hrs after the last dose of CCl(4) to examine its therapeutic effects on chemical-induced liver fibrosis. Upon pathological examination, the HDGL treatment had significantly reversed chemical-induced liver fibrosis and other hepatic lesions. Hepatic collagen accumulation induced by CCl(4) was markedly reduced by HDGL treatment, as evidenced by hepatic collagen content and by immunohistochemical analysis of type-I collagen in liver. HDGL appeared to stimulate the collagenolytic process in the liver, as a 30-50% increase in urinary excretion of hydroxyproline was observed with HDGL treatment as compared to rats only given CCl(4). In conclusion, HDGL can effectively reverse chemically induced liver fibrosis, and this appears to be due, at least in part, to the stimulation of hepatic collagenolysis, resulting in a resolution of hepatic fibrosis.

Animals↗
PubMed2003

Human prostate cancer precursors and pathobiology.

Prostate cancer is among the most common malignancies. It is estimated that 1 in 6 men in the United States will be diagnosed with this disease. Despite the high prevalence and importance of prostate cancer, the molecular mechanisms underlying its development and progression remain poorly understood. This article reviews new information about the roles of oxidants and electrophiles in prostate cancer; the potential importance of chronic inflammation and atrophy in prostate carcinogenesis, and implications for chemoprevention; evidence supporting telomere shortening and genetic instability in the etiology of prostate cancer; and alpha-methylacyl-coenzyme A racemase (AMACR) as a potential marker for prostate carcinogenesis. These new results show that at least some high-grade prostatic intraepithelial neoplasias (PIN) and early adenocarcinomas appear to arise from proliferative inflammatory atrophy (PIA). Inflammation and other environmental factors may lead to the destruction of prostate epithelial cells, and increased proliferation may occur as a response to this cell death. Such proliferation may be mechanistically related to decreased p27(Kip1) observed in PIA. The decreased apoptosis associated with these events may also be related to increased expression of Bcl-2. Increased oxidant and electrophile stress in the setting of increased proliferation associated with these events may lead to elevated glutathione S-transferase P1 (GSTP1) expression as a genomic-protective measure. However, aberrant methylation of the CpG island of the GSTP1 gene promoter silences GSTP1 gene expression and protein levels, setting the stage for additional genetic damage and accelerated progression toward PIN and carcinoma. Additional results show that AMACR may be an important new marker of prostate cancer, and its use in combination with p63 staining may provide the basis for an improved method for identification of prostate cancer.

Adenocarcinoma↗
PubMed2003

Looking beyond morphology: cancer gene expression profiling using DNA microarrays.

Although molecular testing has been increasingly used in clinical practice, the precise diagnosis and prognosis of most human cancers still heavily rely on descriptive histopathological data. Identification of robust molecular markers associated with distinctive morphological parameters will assist in diagnostic and prognostic assessment. On the other hand, the diversity of morphologically identical/similar cancers can be manifested at multiple levels, most importantly at the level of clinical outcome. In the past several years, DNA microarray technology has been widely used in the context of cancer research, resulting in a deluge of new information that can be used to identify molecular alterations common to all tumors as well as signatory profiles unique to a subcategory of cancers. These new findings will very likely transform the clinical management of cancer patients in the near term. This article reviews recent advances in cancer gene expression-profiling results derived from the application of DNA microarray technology, with an emphasis on studies performed on human prostate cancer specimens. We discuss broad issues relevant to cancer expression profiling and attempt to illustrate the rapid pace of novel discoveries using prostate cancer as examples wherever appropriate.

DNA, Neoplasm↗
PubMed2003

Alpha-methylacyl-CoA racemase: a variably sensitive immunohistochemical marker for the diagnosis of small prostate cancer foci on needle biopsy.

Expression of the alpha-methylacyl-CoA racemase (AMACR) gene has recently been demonstrated by several groups to be markedly elevated in prostate cancer cells with little expression in benign prostate tissue and has been suggested as a molecular marker of prostate cancer on needle biopsy. There is scant data, however, as to the sensitivity and specificity of AMACR in the diagnosis of small foci of cancer on needle biopsy. A total of 209 needle biopsies of the prostate with small foci (<5% of a core) of prostatic adenocarcinoma were identified. A total of 175 cases were received in consultation by one of the authors (140 from a single institution and 35 from different outside institutions) and 34 cases were from our hospital file. Immunohistochemistry for high molecular weight cytokeratin and p63 was performed in all cases to confirm the diagnosis of cancer. Only AMACR staining that was significantly stronger than that of background benign glands was considered positive; 88% of all cases of prostate cancer were positive for AMACR. The sensitivity varied among the different groups: 100% for the in house cases, 87.1% for the cases from a single institution, and 80% for cases from different outside institutions. The mean percentage of stained glands in positive cases was 95.9%, with 150 (71.8%) cases showing 100% of the glands positive and 25 (12.0%) cases showing no staining. Because negative staining for basal cell markers, especially in a small focus of atypical glands, is not necessarily diagnostic of prostate cancer, positive staining for AMACR can increase the level of confidence in establishing a definitive malignant diagnosis. However, the sensitivity of AMACR staining may vary in specimens from different pathology laboratories, possibly related to differences in fixation and processing. It is important to optimize the staining technique for each laboratory and recognize that some small cancers on needle biopsy may be AMACR negative.

Adenocarcinoma↗
PubMed2003

[Tissue microarray and in situ hybridization study on hypoxia inducible factor 1alpha mRNA expression in epithelial ovarian tumor].

OBJECTIVE: To study the expression and significance of hypoxia inducible factor 1alpha (HIF-1alpha) in epithelial ovarian tumors. METHODS: The expression of HIF-1alpha mRNA in 295 patients with epithelial ovarian tumor was analyzed retrospectively by high-throughput tissue microarray and in situ hybridization, which was compared with 13 normal ovarian tissue samples. RESULTS: The expression rates of HIF-1alpha mRNA were 0, 13.2%, 42.1% and 81.9% in normal ovarian tissue, benign, borderline and malignant ovarian tumors. Expression rate of HIF-1alpha mRNA in borderline and invasive tumor was significantly higher than those in normal ovarian tissue and benign tumor (P < 0.001). Statistical analysis revealed that the expression of HIF-1alpha mRNA was not related to FIGO stages or histological subtypes. Close negative relation was observed between the expression of HIF-1alpha mRNA and tumor histological differentiation (P < 0.001). CONCLUSION: The overexpression of HIF-1alpha may play an important role in oncogenesis of epithelial ovarian tumor. Tissue microarray is an efficient technique of molecular biology.

Adult↗