Real-time PCR (real-time + pcr)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Real-time PCR

  • quantitative real-time pcr

  • Terms modified by Real-time PCR

  • real-time pcr amplification
  • real-time pcr analysis
  • real-time pcr method

  • Selected Abstracts


    RAPHIDOPHYCEAE [CHADEFAUD EX SILVA] SYSTEMATICS AND RAPID IDENTIFICATION: SEQUENCE ANALYSES AND REAL-TIME PCR ASSAYS,

    JOURNAL OF PHYCOLOGY, Issue 6 2006
    Holly A. Bowers
    Species within the class Raphidophyceae were associated with fish kill events in Japanese, European, Canadian, and U.S. coastal waters. Fish mortality was attributable to gill damage with exposure to reactive oxygen species (peroxide, superoxide, and hydroxide radicals), neurotoxins, physical clogging, and hemolytic substances. Morphological identification of these organisms in environmental water samples is difficult, particularly when fixatives are used. Because of this difficulty and the continued global emergence of these species in coastal estuarine waters, we initiated the development and validation of a suite of real-time polymerase chain reaction (PCR) assays. Sequencing was used to generate complete data sets for nuclear encoded small-subunit ribosomal RNA (SSU rRNA; 18S); internal transcribed spacers 1 and 2, 5.8S; and plastid encoded SSU rRNA (16S) for confirmed raphidophyte cultures from various geographic locations. Sequences for several Chattonella species (C. antiqua, C. marina, C. ovata, C. subsalsa, and C. verruculosa), Heterosigma akashiwo, and Fibrocapsa japonica were generated and used to design rapid and specific PCR assays for several species including C. verruculosa Hara et Chihara, C. subsalsa Biecheler, the complex comprised of C. marina Hara et Chihara, C. antiqua Ono and C. ovata, H. akashiwo Ono, and F. japonica Toriumi et Takano using appropriate loci. With this comprehensive data set, we were also able to perform phylogenetic analyses to determine the relationship between these species. [source]


    3,-azido-3,-deoxythymidine induces deletions in L5178Y mouse lymphoma cells,,

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 3-4 2007
    Jianyong Wang
    Abstract 3,-Azido-3,-deoxythymidine (AZT), a nucleoside analogue used for the treatment of acquired immunodeficiency syndrome (AIDS), induced a significant dose-related increase in the thymidine kinase (Tk) mutant frequency (MF) in L5178Y/Tk+/, 3.7.2C mouse lymphoma cells. Treatment with 1 mg/ml (3,742 ,M) AZT for 24 hr resulted in a MF of 407 × 10,6 compared to a control MF of 84 × 10,6. The MFs of the large and small colony mutants resulting from AZT exposure were 142 × 10,6 and 265 × 10,6, respectively. One hundred and fifty mutants from the 1 mg/ml (3,742 ,M) AZT-treated culture and sixty-nine mutants from independent untreated cultures were isolated and analyzed. LOH analysis using a heteromorphic microsatellite locus located in the Tk gene was performed to determine the presence or absence of the Tk+ allele. Eight other microsatellite markers spanning the entire mouse chromosome 11 also were examined for heterozygosity to determine the extent of LOH. In addition, Tk gene dosage analysis was conducted using Real-Time PCR in those mutants showing LOH at the Tk locus. The presence of only one Tk allele based on Real-Time PCR indicated that the mutant resulted from deletion while the presence of two alleles was consistent with a recombination event. More mutants from the AZT-treated culture showed Tk LOH than did independent mutants from the untreated cultures (91% vs. 64%) and the induced mutants also showed distinct chromosome 11 LOH patterns. The mutation spectrum of mutants from AZT-treated cells was also significantly different from that of spontaneous mutants. More deletions and fewer intragenic mutations were observed in the mutants from the AZT-treated culture than independent mutants from the untreated control. Our data indicate that AZT primarily induced LOH mutations in L5178Y mouse lymphoma cells and a large number of LOH mutations resulted from deletions. Environ. Mol. Mutagen., 2007. Published 2007 Wiley-Liss, Inc. [source]


    Molecular determinants of irinotecan efficacy

    INTERNATIONAL JOURNAL OF CANCER, Issue 10 2006
    Daniel Vallböhmer
    Abstract Molecular markers predicting the efficacy of CPT-11 based chemotherapies in patients with colorectal cancer (CRC) are unknown. Therefore, we investigated whether mRNA levels of drug targets (Topoisomerase I, TS), enzymes involved in 5-FU metabolism (DPD), in angiogenesis (EGFR, IL-8, VEGF) and in DNA-repair/drug detoxification (ERCC1, GST-P1) are associated with the clinical outcome of patients with CRC treated with first-line CPT-11 based chemotherapy. Thirty three patients with metastatic CRC were included in the study. Intratumoral gene expression levels were assessed from paraffin-embedded tissue samples, using laser capture microdissection and quantitative Real-Time PCR. Complete response was observed in 1 patient, partial response in 12 patients, stable disease in 13 patients and progressive disease in 6 patients. Response was inevaluable for 1 patient. Patients with complete response or partial response were classified as responders, while patients with stable disease or progressive disease were classified as nonresponders. High intratumoral mRNA levels of EGFR, ERCC1 and GSPT-P1 were each significantly associated with response to CPT-11 based chemotherapy. Recursive partitioning analysis showed that mRNA levels of EGFR and ERCC1 are primarily responsible for delineating responders from nonresponders. Also, the combination of high intratumoral gene expression levels of both EGFR and ERCC1 was significantly associated with progression-free survival. The mRNA levels of EGFR had a significant correlation with expression levels of ERCC1, GST-P1 and VEGF. This small retrospective study suggests that gene expression levels of EGFR, ERCC1 and GST-P1 may be useful in predicting the clinical outcome of patients with metastatic CRC treated with first-line CPT-11 based chemotherapy. © 2006 Wiley-Liss, Inc. [source]


    Putative-farnesoic acid O -methyltransferase (FAMeT) in medfly reproduction

    ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2010
    Laura Vannini
    Abstract A gene potentially involved in juvenile hormone (JH) biosynthesis was previously identified in Ceratitis capitata as the putative- farnesoic acid O-methyltransferase (FAMeT). Since JH is involved in insect reproduction, we silenced the putative-FAMeT expression by RNA interference in Ceratitis capitata to evaluate its implication in egg production. FAMeT gene expression was knocked down in females and males after eclosion and in 1- and 2-day-old females. Treated specimens were left to mate with each other or with untreated partners to evaluate the extent of each sex influencing egg production. Gene silencing was investigated by Real-Time PCR. Results unambiguously showed that FAMeT has a measurable role on the fertility of both medfly sexes. © 2010 Wiley Periodicals, Inc. [source]


    The putative-farnesoic acid O -methyl transferase (FAMeT) gene of Ceratitis capitata: characterization and pre-imaginal life expression

    ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2010
    Laura Vannini
    Abstract Farnesoic acid O -methyl transferase (FAMeT) is the enzyme involved in the penultimate step of insect juvenile hormone (JH) biosynthesis and is thus a key regulator in insect development and reproduction. We report the characterization of the putative- FAMeT in the medfly or Mediterranean fruit fly, Ceratitis capitata. This gene was identified by suppressive subtractive hybridization and completely sequenced by the screening of a medfly cDNA library. The obtained sequence was analyzed for conserved protein domain identification and its expression profile was evaluated by quantitative Real-Time PCR in medfly pre-imaginal life. The tissue expression of the isolated gene was verified by in situ hybridization on third instar larvae sections. The characterization of the isolated gene pointed out several typical features of methyl transferase genes. The pre-imaginal putative- FAMeT expression levels were consistent with JH titer change in Diptera. As recognized in some crustaceans, this gene seems to be widely expressed in the medfly as well. Ceratitis capitata is one of the most relevant agricultural pests against which insecticides and the sterile insect technique (SIT) are extensively used in spite of the well-known limitations of these approaches. Although results are not conclusive for the physiological role of the isolated gene, they suggest the characterization of a new gene in the Mediterranean fruit fly potentially involved in JH biosynthesis and may, therefore, have implications for pest control. © 2010 Wiley Periodicals, Inc. [source]


    Aroclor 1254 alters morphology, survival, and gene expression in Xenopus laevis tadpoles

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2002
    Anna M. Jelaso
    Abstract PCBs are persistent environmental contaminants that cause a variety of adverse health effects in wildlife and humans. This article describes the use of signature gene expression patterns that link increased PCB exposure with progressive, adverse biological effects. Developing Xenopus laevis tadpoles of two age classes were exposed to the PCB mixture Aroclor 1254 for 2 days. Real-time PCR was used to quantitate mRNA expression for 11 physiologically relevant, potential bioindicator genes. Younger tadpoles (5 days postfertilization) were resistant to Aroclor 1254 and showed few changes in gross morphology, swimming behavior, survival, or gene expression. Older tadpoles (11 days postfertilization) were more susceptible to Aroclor 1254. Exposure to 25 and 50 ppm Aroclor 1254 caused alterations in gross morphology and swimming behavior and statistically significant decreases in survival. These tadpoles showed statistically significant decreases in gene expression for 9 out of the 11 genes measured. Tadpoles exposed to 10 ppm showed incipient health changes but had gene expression profiles similar to the tadpoles treated with higher doses of Aroclor 1254. Tadpoles exposed to 1 ppm did not exhibit any observable adverse health effects, yet statistically significant decreases in gene expression occurred in these tadpoles (4 out of 11 genes). After prolonged exposure, tadpoles exposed to 1 and 10 ppm Aroclor 1254 exhibited health effects similar to those exposed to higher concentrations. Therefore, changes in expression of specific genes may serve not only as molecular bioindicators of Aroclor 1254 exposure but also as predictors of impending adverse health effects. Environ. Mol. Mutagen. 40:24,35, 2002. © 2002 Wiley-Liss, Inc. [source]


    Real-time PCR assay for the identification of Thrips palmi,

    EPPO BULLETIN, Issue 1 2005
    L. F. F. Kox
    Since Thrips palmi became a regulated pest for most European countries, inspections at points of entry into Europe and monitoring in Europe have intensified not only for T. palmi but also for thrips as a whole. Morphological identification of thrips is performed on adults and to a lesser extent on second-stage larvae only, because no adequate identification keys for the separation of species based on the characteristics of eggs, first-stage larvae, pre-pupae or pupae are available. We have developed a real-time PCR assay based on TaqMan. A T. palmi -specific set of primers and probe were selected within the mitochondrial cytochrome oxidase I (COI) gene. The specificity of the assay was assessed using 15 specimens of Thrips palmi and 61 specimens of 23 other thrips species commonly occuring in Europe. All T. palmi specimens were detected, and no cross reactions with other thrips were observed. The method was tested on single larvae and adults and proved to be applicable for both those stages of T. palmi. [source]


    Mobilisation of tumour cells along with CD34+ cells to peripheral blood in multiple myeloma

    EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5-6 2001
    Lene Meldgaard Knudsen
    Abstract:Background: Cells belonging to the malignant clone are found in the peripheral blood in myeloma patients. In order to minimise the content of tumour cells in the stem cell product it is crucial to perform stem cell harvest at a time when tumour cells in the peripheral blood are at a minimum. Objective: The aim of the study was to compare the mobilisation kinetics of normal CD34+ cells and myeloma plasma cells during mobilisation with either G-CSF alone or high-dose cyclophosphamide (HDCy) plus G-CSF. Design and methods: Morning blood samples were drawn each day during mobilisation from start of G-CSF or HDCy and to the end of leukapheresis, and were analysed by flow cytometry for content of CD34+ cells and myeloma plasma cells (CD38+ + CD45,). Tumour cells were also estimated by a patient-specific real-time polymerase chain reaction (PCR) method based on the 5, nuclease TaqMan technology. Results: Flow cytometry data from 16 patients showed concomitant mobilisation of CD34+ cells and myeloma plasma cells. Seven patients were mobilised twice; first with G-CSF alone and then with HDCy plus G-CSF. There was no difference between the two mobilisation regimens regarding tumour cell mobilisation kinetics. Real-time PCR was performed in one patient and confirmed the mobilisation of tumour cells at the time when CD34+ blood cells were at a maximum. Conclusions: Tumour cells are mobilised to the peripheral blood at the same time as CD34+ cells in multiple myeloma patients after priming with both G-CSF alone and HDCy in combination with G-CSF. [source]


    Retina expresses a novel variant of the ryanodine receptor

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2007
    Varda Shoshan-Barmatz
    Abstract Calcium released from intracellular stores via the ryanodine receptor (RyR) mediates a variety of signalling processes. We previously showed that retina expresses the three known types of RyR, but retinal membrane preparations exhibit unique characteristics such as Ca2+ -independent [3H]ryanodine-binding and inhibition by caffeine. We have heretofore suggested that the major retinal RyR isoform is novel. The present study aimed to identify this receptor isoform and to localize RyR in mammalian retina. Immunoblotting with specific and pan-antibodies showed that the major retinal RyR has a mobility similar to that of RyR2 or RyR3. Real-time PCR revealed that the major type is RyR2, and RT-PCR followed by sequencing showed a transcript that encodes a protein with ~ 99% identity to RyR2, yet lacking two regions of seven and 12 amino acids and including an additional insertion of eight amino acids. An antibody against RyR2 localized this type to somas and primary dendrites of most retinal neurons. An antibody against RyR1 localized RyR to most somas but also revealed staining in photoreceptor outer segments, concentrated on the disk membranes at their rim. The ryanodine-binding properties and the electrophoretic mobility of RyR from the outer segments were similar to those of the whole retinal preparation. The results thus identify a novel variant of RyR2 which can contribute to regulating photoreceptor Ca2+ concentrations. The restricted localization of the outer segment RyR to the disk rim suggests that its activation mechanism involves a coupling between retinal RyR and the cGMP-gated channel. [source]


    Peptide antibiotic human beta-defensin-1 and ,2 contribute to antimicrobial defense of the intrahepatic biliary tree

    HEPATOLOGY, Issue 4 2004
    Kenichi Harada
    Human beta-defensins (hBDs) are important antimicrobial peptides that contribute to innate immunity at mucosal surfaces. This study was undertaken to investigate the expression of hBD-1 and hBD-2 in intrahepatic biliary epithelial cells in specimens of human liver, and 4 cultured cell lines (2 consisting of biliary epithelial cells and 2 cholangiocarcinoma cells). In addition, hBD-1 and hBD-2 were assayed in specimens of bile. hBD-1 was nonspecifically expressed immunohistochemically in intrahepatic biliary epithelium and hepatocytes in all patients studied, but expression of hBD-2 was restricted to large intrahepatic bile ducts in 8 of 10 patients with extrahepatic biliary obstruction (EBO), 7 of 11 with hepatolithiasis, 1 of 6 with primary biliary cirrhosis (PBC), 1 of 5 with primary sclerosing cholangitis (PSC), 0 of 6 with chronic hepatitis C (CH-C), and 0 of 11 with normal hepatic histology. hBD-2 expression was evident in bile ducts exhibiting active inflammation. Serum C reactive protein levels correlated with biliary epithelial expression of hBD-2. Real-time PCR revealed that in all of 28 specimens of fresh liver, including specimens from patients with hepatolithiasis, PBC, PSC, CH-C and normal hepatic histology, hBD-1 messenger RNA was consistently expressed, whereas hBD-2 messenger RNA was selectively expressed in biliary epithelium of patients with hepatolithiasis. Immunobloting analysis revealed hBD-2 protein in bile in 1 of 3 patients with PSC, 1 of 3 with PBC, and each of 6 with hepatolithiasis; in contrast, hBD-1 was detectable in all bile samples examined. Four cultured biliary epithelial cell lines consistently expressed hBD-1; in contrast these cell lines did not express hBD-2 spontaneously but were induced to express hBD-2 by treatment with Eschericia coli, lipopolysaccharide, interleukin-1, or tumor necrosis factor-,. In conclusion, these findings suggest that in the intrahepatic biliary tree, hBD-2 is expressed in response to local infection and/or active inflammation, whereas hBD-1 may constitute a preexisting component of the biliary antimicrobial defense system. Supplementary material for this article can be found on the Hepatology website (http:/interscience.wley.com/jpages/0270,9139/suppmat/index.html). (Hepatology 2004;40:925-932). [source]


    Isolation and characterization of epithelial progenitor cells from human fetal liver

    HEPATOLOGY RESEARCH, Issue 1 2008
    Yi-Nan Liu
    Aim:, Hepatic progenitor cells can serve as an alternative source of hepatocytes for the treatment of liver diseases. Methods:, We isolated and expanded the epithelial progenitor cells (EPC) from the human fetal liver and investigated the differentiation of EPC into hepatic cells by fluorescence-activated cell sorter (FACS), real-time polymerase chain reaction (PCR), immunofluorescence assay, western blotting, and periodic acid,Schiff staining. Results:, Isolated EPC possessed highly proliferative ability and subpassaged for more than 25 passages. Real-time PCR showed that EPC expressed liver epithelial markers (cytokeratin [CK]8 and CK18) and biliary-specific markers (CK7 and CK19). FACS analysis indicated that these cells were positive for CD117, CD147, CD90, CD44, human leucocyte antigen class I and CD71, but negative for CD34 and CD45. The EPCpossessed multipotential indicated by differentiating into osteoblasts and adipocytes; when subjected to the hepatic differentiation condition, EPC could be induced to hepatocyte-like cells, which expressed albumin, alpha-fetoprotein, and CK18 proteins. Two months after EPC transplantation, we observed that the grafted cells differentiated into hepatocyte-like cells and there was no observable tumor mass. Conclusion:, We have isolated and characterized the human fetal liver-derived EPC and these cells may serve as an ideal cell source for cell-replacement therapy of diseased livers. [source]


    Over-expression of phosphatase of regenerating liver-3 correlates with tumor progression and poor prognosis in nasopharyngeal carcinoma

    INTERNATIONAL JOURNAL OF CANCER, Issue 8 2009
    Jun Zhou
    Abstract This study aimed at clarifying the expression of phosphatase of regenerating liver-3 (PRL-3), one member of protein tyrosine phosphatase (PTP) superfamily, in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathologic features, including the survival of patients with NPC. Real-time PCR and Western blot showed that the expression level of PRL-3 was markedly higher in NPC cell lines than that in the normal nasopharyngeal epithelial cell at both mRNA and protein levels. Immunohistochemical analysis revealed overexpression of PRL-3 in 97 of 174 (55.7%) paraffin-embedded archival NPC biopsies. Statistical analysis showed that PRL-3 expression was positively correlated with N classification (p = 0.033), distant metastasis (M classification, p = 0.048) and clinical stage (p = 0.005) of patients. Patients with higher PRL-3 expression had shorter overall survival time, whereas patients with lower level of PRL-3 had better survival. Multivariate analysis suggested that PRL-3 expression might be an independent prognostic indicator for the survival of patients with NPC. Disruption of endogenous PRL-3 protein through a siRNA knockdown technique was shown to suppress the invasion ability and migration potency of 5-8F and HONE1 cells, substantially. Interestingly, we also found that no significant effect on the proliferation of 5-8F and HONE1 cells was observed after PRL-3 was down-regulated. Our results suggest that PRL-3 protein is a valuable marker for progression of NPC patients. High PRL-3 expression is associated with poor overall survival in patients with NPC. © 2008 Wiley-Liss, Inc. [source]


    Real-time PCR quantification of haematopoietic chimerism after transplantation: a comparison between TaqMan and hybridization probes technologies

    INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1p1 2010
    J. MARTINEZ-LOPEZ
    Summary This study aimed to compare the sensitivity and accuracy of two methods of quantitative real-time polymerase chain reaction (qrt-PCR), in order to determine haematopoietic chimerism (CH): single nucleotide polymorphisms using TaqMan (TM) probes and insertion/deletion polymorphisms using Hybridization (Hyb) probes. A total of 106 samples from 20 patients who underwent allogenic stem cell transplantation (n = 14) or live-donor liver transplantation (n = 6) were studied. The mean level of chimerism was 8.37% for the TM method and 7.73% in the Hyb method, which was not significantly different (P = 0.69). The Pearson correlation coefficient between the two methods was r = 0.91 (P < 0.001). The estimation of the regression line, using the Passing and Balbock method was Intercept A ,0.0381 [95% confidence interval (CI) ,0.1265 to 0.0296) and Slope B: 1.04609(95% CI 0.9349,1.161). Bland,Altman data showed that the standard deviations, which differed between the two methods (%Hyb,%TM), were 0.98 and ,1.28. The accuracy and sensitivity of qrt-PCR chimerism is independent of the method used if the optimization is adequate and satisfies the criteria for adequate study. Real-time PCR, independent of the method adopted, is a very good tool for study levels of CH. [source]


    Overexpression of secreted frizzled-related protein 1 inhibits bone formation and attenuates parathyroid hormone bone anabolic effects

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2010
    Wei Yao
    Abstract Secreted frizzled-related protein 1 (sFRP1) is an antagonist of Wnt signaling, an important pathway in maintaining bone homeostasis. In this study we evaluated the skeletal phenotype of mice overexpressing sFRP1 (sFRP1 Tg) and the interaction of parathyroid hormone (PTH) treatment and sFRP1 (over)expression. Bone mass and microarchitecture were measured by micro-computed tomography (µCT). Osteoblastic and osteoclastic cell maturation and function were assessed in primary bone marrow cell cultures. Bone turnover was assessed by biochemical markers and dynamic bone histomorphometry. Real-time PCR was used to monitor the expression of several genes that regulate osteoblast maturation and function in whole bone. We found that trabecular bone mass measurements in distal femurs and lumbar vertebral bodies were 22% and 51% lower in female and 9% and 33% lower in male sFRP1 Tg mice, respectively, compared with wild-type (WT) controls at 3 months of age. Genes associated with osteoblast maturation and function, serum bone formation markers, and surface based bone formation were significantly decreased in sFRP1 Tg mice of both sexes. Bone resorption was similar between sFRP1 Tg and WT females and was higher in sFRP1 Tg male mice. Treatment with hPTH(1-34) (40,µg/kg/d) for 2 weeks increased trabecular bone volume in WT mice (females: +30% to 50%; males: +35% to 150%) compared with sFRP1 Tg mice (females: +5%; males: +18% to 54%). Percentage increases in bone formation also were lower in PTH-treated sFRP1 Tg mice compared with PTH-treated WT mice. In conclusion, overexpression of sFRP1 inhibited bone formation as well as attenuated PTH anabolic action on bone. The gender differences in the bone phenotype of the sFRP1 Tg animal warrants further investigation. © 2010 American Society for Bone and Mineral Research [source]


    Vitamin D Receptor: Key Roles in Bone Mineral Pathophysiology, Molecular Mechanism of Action, and Novel Nutritional Ligands,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue S2 2007
    Peter W Jurutka
    Abstract The vitamin D hormone, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], binds with high affinity to the nuclear vitamin D receptor (VDR), which recruits its retinoid X receptor (RXR) heterodimeric partner to recognize vitamin D responsive elements (VDREs) in target genes. 1,25(OH)2D3 is known primarily as a regulator of calcium, but it also controls phosphate (re)absorption at the intestine and kidney. Fibroblast growth factor 23 (FGF23) is a phosphaturic hormone produced in osteoblasts that, like PTH, lowers serum phosphate by inhibiting renal reabsorption through Npt2a/Npt2c. Real-time PCR and reporter gene transfection assays were used to probe VDR-mediated transcriptional control by 1,25(OH)2D3. Reporter gene and mammalian two-hybrid transfections, plus competitive receptor binding assays, were used to discover novel VDR ligands. 1,25(OH)2D3 induces FGF23 78-fold in osteoblasts, and because FGF23 in turn represses 1,25(OH)2D3 synthesis, a reciprocal relationship is established, with FGF23 indirectly curtailing 1,25(OH)2D3 -mediated intestinal absorption and counterbalancing renal reabsorption of phosphate, thereby reversing hyperphosphatemia and preventing ectopic calcification. Therefore, a 1,25(OH)2D3,FGF23 axis regulating phosphate is comparable in importance to the 1,25(OH)2D3,PTH axis that regulates calcium. 1,25(OH)2D3 also elicits regulation of LRP5, Runx2, PHEX, TRPV6, and Npt2c, all anabolic toward bone, and RANKL, which is catabolic. Regulation of mouse RANKL by 1,25(OH)2D3 supports a cloverleaf model, whereby VDR-RXR heterodimers bound to multiple VDREs are juxtapositioned through chromatin looping to form a supercomplex, potentially allowing simultaneous interactions with multiple co-modulators and chromatin remodeling enzymes. VDR also selectively binds certain ,3/,6 polyunsaturated fatty acids (PUFAs) with low affinity, leading to transcriptionally active VDR-RXR complexes. Moreover, the turmeric-derived polyphenol, curcumin, activates transcription of a VDRE reporter construct in human colon cancer cells. Activation of VDR by PUFAs and curcumin may elicit unique, 1,25(OH)2D3 -independent signaling pathways to orchestrate the bioeffects of these lipids in intestine, bone, skin/hair follicle, and other VDR-containing tissues. [source]


    Diminished Bone Formation During Diabetic Fracture Healing is Related to the Premature Resorption of Cartilage Associated With Increased Osteoclast Activity,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2007
    Rayyan A Kayal
    Abstract Histological and molecular analysis of fracture healing in normal and diabetic animals showed significantly enhanced removal of cartilage in diabetic animals. Increased cartilage turnover was associated with elevated osteoclast numbers, a higher expression of genes that promote osteoclastogenesis, and diminished primary bone formation. Introduction: Diminished bone formation, an increased incidence of nonunions, and delayed fracture healing have been observed in animal models and in patients with diabetes. Fracture healing is characterized by the formation of a stabilizing callus in which cartilage is formed and then resorbed and replaced by bone. To gain insight into how diabetes affects fracture healing, studies were carried out focusing on the impact of diabetes on the transition from cartilage to bone. Materials and Methods: A low-dose treatment protocol of streptozotocin in CD-1 mice was used to induce a type 1 diabetic condition. After mice were hyperglycemic for 3 weeks, controlled closed simple transverse fractures of the tibia were induced and fixed by intramedullary pins. Histomorphometric analysis of the tibias obtained 12, 16, and 22 days after fracture was performed across the fracture callus at 0.5 mm proximal and distal increments using computer-assisted image analysis. Another group of 16-day samples were examined by ,CT. RNA was isolated from a separate set of animals, and the expression of genes that reflect the formation and removal of cartilage and bone was measured by real-time PCR. Results: Molecular analysis of collagen types II and × mRNA expression showed that cartilage formation was the same during the initial period of callus formation. Histomorphometric analysis of day 12 fracture calluses showed that callus size and cartilage area were also similar in normoglycemic and diabetic mice. In contrast, on day 16, callus size, cartilage tissue, and new bone area were 2.0-, 4.4-, and 1.5-fold larger, respectively, in the normoglycemic compared with the diabetic group (p < 0.05). Analysis of ,CT images indicated that the bone volume in the normoglycemic animals was 38% larger than in diabetic animals. There were 78% more osteoclasts in the diabetic group compared with the normoglycemic group (p < 0.05) on day 16, consistent with the reduction in cartilage. Real-time PCR showed significantly elevated levels of mRNA expression for TNF-,, macrophage-colony stimulating factor, RANKL, and vascular endothelial growth factor-A in the diabetic group. Similarly, the mRNA encoding ADAMTS 4 and 5, major aggrecanases that degrade cartilage, was also elevated in diabetic animals. Conclusions: These results suggest that impaired fracture healing in diabetes is characterized by increased rates of cartilage resorption. This premature loss of cartilage leads to a reduction in callus size and contributes to decreased bone formation and mechanical strength frequently reported in diabetic fracture healing. [source]


    Suppression of growth of pancreatic cancer cell and expression of vascular endothelial growth factor by gene silencing with RNA interference

    JOURNAL OF DIGESTIVE DISEASES, Issue 4 2008
    Jian WANG
    OBJECTIVE: To explore the anti-angiogenesis and tumor cell growth suppressive effects resulted from gene silencing by RNAi in BxPC-3 human pancreatic cancer cells. METHODS: The designation and transfection of vascular endothelial growth factor (VEGF)-siRNA lentivirus was carried out in vitro. Real-time PCR and western blot were conducted to measure the expression levels of VEGF mRNA and protein. Flow cytometry was employed to evaluate cell apoptosis and cell death. A lactate dehydrogenase (LDH) assay was used to assess the cytotoxicity of VEGF-siRNA. A 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was used to picture the cellular growth. For the in vivo study, BxPC-3 cells were injected subcutaneously into nude mice to form xenografts. The mice were divided into three groups according to the intervention used. The control group, the negative control group and the knockdown group of mice were injected with saline, an empty lentivirus vehicle and lentivirus carrying VEGF-siRNA, respectively. None of the mice died during the study. When these mice were killed, the xenografts were collected and the tumor sizes of the different groups were compared. Finally, immunohistochemistry was used to assess the VEGF expression level and microvascular density. RESULTS: After the transfection of VEGF-siRNA lentivirus, the cellular expression of VEGF mRNA decreased to 50% of the control and the VEGF protein in the BxPC-3 cells decreased to 30% of the control. Apoptosis and cell death increased after transfection of the VEGF-siRNA lentivirus. The LDH assay showed high cytotoxicity induced by VEGF-siRNA lentivirus transfection. The MTT assay showed slower cellular growth in the knockdown cells. Tumor growth suppression was observed in nude mice that had received the VEGF-siRNA lentivirus transfection, and the tumor sizes of the xenografts in this group were clearly smaller than those in other two groups. VEGF expression and microvascular density were significantly decreased. CONCLUSION: Vascular endothelial growth factor gene silencing via VEGF-siRNA can effectively inhibit the production of VEGF and exert an anti-angiogenesis and tumor cell growth suppressive effect both in vitro and in vivo. [source]


    Real-time PCR for the detection and quantitative analysis of IHNV in salmonids

    JOURNAL OF FISH DISEASES, Issue 6 2001
    K Overturf
    The rapid identification and quantification of virus in diseased fish is a goal both conservationists and commercial aquaculturists have struggled to attain. Recently a technique for the detection of viral mRNA particles that uses fluorescent tagging and amplification has been developed. Utilizing primers and fluorescent labelled probes generated for the specific identification of the nucleocapsid (N) and glycoprotein (G) genes of infectious haematopoietic necrosis virus (IHNV), and an instrument that measures cyclic emittance of fluorescence, the presence or absence of virus can be easily and rapidly confirmed. This method is not only useful in confirming viral presence but is effective in measuring the relative or absolute quantity of virus present within the sample. This allows for the determination of the health status of a carrier fish by measuring the quantity of viral genomes or transcribed viral genes present. Because this method is based on sequence detection, instead of virus isolation in cell culture, it is also effective in determining the presence of pathogenic organisms from water, fish feeds, or other potential reservoirs of infection. [source]


    Analysis of mixed infections by multiple genotypes of human cytomegalovirus in immunocompromised patients

    JOURNAL OF MEDICAL VIROLOGY, Issue 5 2009
    P. Sowmya
    Abstract Human cytomegalovirus (HCMV) is a significant cause of morbidity and mortality in immunocompromised patients. The present study was carried out to determine the frequency of occurrence of multiple genotypes of HCMV in immunocompromised patients, to determine if there is any discrepancy in identification of mixed infections by multiple genotypes in paired clinical specimens obtained from patients and to determine the significance of viral load differences between patients infected with single and multiple genotypes. One hundred clinical specimens from 75 patients were included in the study. Real-time PCR; Multiplex PCR and PCR-based RFLP were applied for the determination of viral load and genotyping of HCMV, respectively. Out of the 75 patients, 36 (48%) carried multiple genotypes. Discrepancy with regard to detection of genotypes were found in 17/25 patients whose paired clinical specimens were analyzed. Mixed genotypes were found more often in peripheral blood than urine or intraocular fluids collected from the same patient. There was a statistically significant difference between the median viral loads of clinical specimens carrying single genotypes and multiple genotypes. Mixed infections with multiple genotypes were found predominantly in the leukocyte fraction of peripheral blood specimens. The detection of mixed infections by multiple genotypes in the hypervariable regions of HCMV can be a surrogate marker of an increase in viral load. J. Med. Virol. 81:861,869, 2009. © 2009 Wiley-Liss, Inc. [source]


    Quantitation of myelin oligodendrocyte glycoprotein and myelin basic protein in the thymus and central nervous system and its relationship to the clinicopathologic features of autoimmune encephalomyelitis

    JOURNAL OF NEUROSCIENCE RESEARCH, Issue 3 2006
    Hiroshi Sakuma
    Abstract There is controversy whether the amount of autoantigens expressed in the thymus regulates negative selection of autoreactive T cells and determine susceptibility or resistance to experimental autoimmune encephalomyelitis (EAE). In the present study, we have addressed this issue by quantifying neuroantigens in the thymus of two EAE-susceptible (LEW and LEW.1AV1) and one EAE-resistant (BN) rat strains. We further examined whether amounts of neuroantigens in various parts of the central nervous system (CNS) affect the clinical course and lesion distribution of acute and chronic EAE. Real-time PCR and histologic analyses showed that there was no significant difference in the amount and distribution of myelin oligodendrocyte glycoprotein and myelin basic protein in the thymus and CNS among the three strains and that both acute and chronic EAE lesions in the CNS were preferentially distributed in the area where neuroantigens were abundantly present. These findings suggest that susceptibility or resistance to EAE is not regulated by the amount of the neuroantigens expressed in the thymus. Furthermore, the lesion distribution, but not the clinical course, of EAE is related to the neuroantigen expression in the CNS. © 2006 Wiley-Liss, Inc. [source]


    Expression of keratinocyte growth factor and its receptor in odontogenic keratocysts

    JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 5 2009
    Y. Suyama
    Background:, The mitotic activity of the epithelial cells of odontogenic keratocysts (OKCs) is greater than that of other odontogenic jaw cysts, and the mitotic activity of the epithelial cells decreases after marsupialization. Keratinocyte growth factor (KGF) interacts with its specific receptor (KGFR), and elicits the proliferation and/or differentiation of the various types of epithelial cells. The aim of this study was to investigate the expression of KGF/KGFR in OKCs before and after marsupialization. Methods:, The expression of KGF was immunohistochemically detected in the specimens of 16 OKCs and 11 dentigerous cysts before and after marsupialization. The expression of KGF mRNA was measured in the fibroblasts isolated from OKCs by real-time PCR. Results:, KGF was expressed in the epithelial cells and fibroblasts of 12 and seven of 16 OKC specimens, respectively. The intensity of the KGF expression in both the epithelial cells and the fibroblasts significantly decreased after marsupialization. KGFR was expressed throughout the epithelium in 15 of 16 OKC specimens, but the intensity of the KGFR expression did not change after marsupialization. The expression of KGF was detected in the epithelium of two of 11 dentigerous cyst specimens, but not in the fibroblasts before marsupialization. Real-time PCR revealed that recombinant human interleukin (IL)-1, increased the expression of KGF mRNA in the fibroblasts isolated from OKCs. Conclusion:, KGF/KGFR signaling may play a crucial role in the epithelial cells of OKCs. Furthermore, the expression of KGF in the fibroblasts of OKCs is regulated by IL-1,. [source]


    Altered binding of MYF-5 to FOXE1 promoter in non-syndromic and CHARGE-associated cleft palate

    JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 1 2009
    Mario Venza
    Background:, Three different homozygous loss-of-function mutations of the Forkhead box E1 (FOXE1) gene have been associated with syndromic cleft palate. Here, we screened the entire promoter region to identify the variations in significant consensus motifs affecting FOXE1 transcription. Method:, Genomic DNAs of 35 cleft palate patients, 10 of whom with CHARGE association, 80 unrelated healthy people and 80 unaffected first-degree relatives were analysed by automatic sequencing. The Transcription Element Search System program was employed to identify transcription factor binding sites. The protein-DNA complexes were observed using DNA band-shift assays and oligonucleotide competition analyses. Real-time PCR was used to estimate FOXE1 expression at mRNA level. Results:, In 11 non-syndromic cleft palate patients, a novel non-coding polymorphism (C,G) in the 5,-untranslated region of FOXE1 was found. The variation fell into a putative consensus sequence for the transcription factor MYF-5 and completely impaired the ability of MYF -5 to bind to its motif, as shown by EMSA experiments. As a consequence, a significantly reduced FOXE1 mRNA expression was observed. Conclusions:, In 45% of non-syndromic cleft palate patients, a novel homozygous polymorphism that prevented the binding of MYF -5 to FOXE1 promoter and affected the FOXE1 expression was found. As recent data show the role of MYF-5 in the muscle-dependent craniofacial skeletal development and in the fusion of primary palate and secondary palate, the results reported here strongly suggest a more significant involvement of this factor in the cleft palate onset. [source]


    A Quantitative Polymerase Chain Reaction Assay for the Detection of Polyscytalum pustulans, the Cause of Skin Spot Disease of Potato

    JOURNAL OF PHYTOPATHOLOGY, Issue 3 2009
    A. K. Lees
    Abstract Skin spot disease of potato caused by the pathogen Polyscytalum pustulans is likely to become more important with the withdrawal of 2-aminobutane as a fungicide, and new methods of control will need to be found. As part of a disease control strategy, it will be necessary to study the disease in more detail, to utilize host resistance and to identify stocks where problems are likely to arise. Existing methods for the detection and quantification of P. pustulans are time-consuming and require specific expertise. Real-time PCR assays have been developed for many pathogens of potato and have subsequently been used as tools for the study of the epidemiology and control of disease. The development of a real-time PCR assay for the detection and quantification of P. pustulans is described. The specificity of the assay was demonstrated and detection was shown to be reliable at levels as low as 20,250 fg/,l DNA, (equivalent to 60,680 pg DNA/g) in soil and on symptomless tubers at attogram (ag) levels. These values are in line with previously developed tests. [source]


    Using Real-time PCR to Discriminate and Quantify the Closely Related Wheat Pathogens Oculimacula yallundae and Oculimacula acuformis

    JOURNAL OF PHYTOPATHOLOGY, Issue 11-12 2005
    K. Walsh
    Abstract Oculimacula yallundae and O. acuformis are the causal agents of eyespot disease of wheat and other cereals. The two fungi react differently to the application of fungicides, but they cannot be distinguished visually and their occurrence is often masked by other less damaging pathogens. Current methods to detect and distinguish Oculimacula species are impractical when testing large numbers of samples. A real-time polymerase chain reaction (PCR) assay, suitable for large-scale testing, was developed and used for quantitative detection and discrimination of O. yallundae and O. acuformis. As the available DNA sequences differ by only a small number of conserved nucleotide polymorphisms, three different methods were investigated to achieve the desired specificity. A combination of mutagenically separated PCR and a shortened primer gave the best specificity for O. yallundae and O. acuformis, respectively. Although the comparison illustrated the practicalities of each method, it was not possible to devise a fixed set of rules for the design of primers to discriminate two closely related sequences; it is assumed that sequence context is an overriding and difficult to predict factor, and that a range of empirical approaches may need to be taken to reach the specificity required. [source]


    Procysteine Stimulates Expression of Key Anabolic Factors and Reduces Plantaris Atrophy in Alcohol-Fed Rats

    ALCOHOLISM, Issue 8 2009
    Jeffrey S. Otis
    Background:, Long-term alcohol ingestion may produce severe oxidant stress and lead to skeletal muscle dysfunction. Emerging evidence has suggested that members of the interleukin-6 (IL-6) family of cytokines play diverse roles in the regulation of skeletal muscle mass. Thus, our goals were (i) to minimize the degree of oxidant stress and attenuate atrophy by supplementing the diets of alcohol-fed rats with the glutathione precursor, procysteine, and (ii) to identify the roles of IL-6 family members in alcoholic myopathy. Methods:, Age- and gender-matched Sprague-Dawley rats were fed the Lieber-DeCarli liquid diet containing either alcohol or an isocaloric substitution (control diet) for 35 weeks. Subgroups of alcohol-fed rats received procysteine (0.35%, w/v) for the final 12 weeks. Plantaris morphology was assessed by hematoxylin and eosin staining. Major components of glutathione metabolism were determined using assay kits. Real-time PCR was used to determine expression levels of several genes. Results:, Plantaris muscles from alcohol-fed rats displayed extensive atrophy, as well as decreased glutathione levels, decreased activities of glutathione reductase and glutathione peroxidase, decreased superoxide dismutase (SOD)-2 (Mn-SOD2), and increased NADPH oxidase-1 gene expression,each indicative of significant oxidant stress. Alcohol also induced gene expression of catabolic factors including IL-6, oncostatin M, atrogin-1, muscle ring finger protein-1, and IGFBP-1. Procysteine treatment attenuated plantaris atrophy, restored glutathione levels, and increased catalase, Cu/Zn-SOD1, and Mn-SOD2 mRNA expression, but did not reduce other markers of oxidant stress or levels of these catabolic factors. Instead, procysteine stimulated gene expression of anabolic factors such as insulin-like growth factor-1, ciliary neurotrophic factor, and cardiotrophin-1. Conclusions:, Procysteine significantly attenuated, but did not completely abrogate, alcohol-induced oxidant stress or catabolic factors. Rather, procysteine minimized the extent of plantaris atrophy by inducing components of several anabolic pathways. Therefore, anti-oxidant treatments such as procysteine supplementation may benefit individuals with alcoholic myopathy. [source]


    Ethanol Increases Fetal Human Neurosphere Size and Alters Adhesion Molecule Gene Expression

    ALCOHOLISM, Issue 2 2008
    Sharada D. Vangipuram
    Background:, Ethanol (ETOH) consumption by pregnant women can result in Fetal Alcohol Spectrum Disorder (FASD). To date, the cellular targets and mechanisms responsible for FASD are not fully characterized. Our aim was to determine if ETOH can affect fetal human brain-derived neural progenitor cells (NPC). Methods:, Neural progenitor cells were isolated by positive selection from normal second trimester fetal human brains (n = 4) and cultured, for up to 72 hours, in mitogenic media containing 0, 1, 10, or 100 mM ETOH. From 48 to 72 hours in culture, neurospheres generated in these conditions were filmed using time-lapse video microscopy. At the end of 72 hours, neurosphere diameter and roundness were measured using videographic software. Mitotic phase analysis of cell-cycle activity and apoptotic cell count were also performed at this time, by flow cytometry using propidium iodide (PI) staining. Real-time PCR was used to estimate expression of genes associated with cell adhesion pathways. Results:, Neurosphere diameter correlated positively (r = 0.87) with increasing ETOH concentrations. There was no significant difference in cell-cycle activity and no significant increase in apoptosis with increasing ETOH concentrations. Time-lapse video microscopy showed that ETOH (100 mM) reduced the time for neurosphere coalescence. Real-time PCR analysis showed that ETOH significantly altered the expression of genes involved in cell adhesion. There was an increase in the expression of , and , Laminins 1, , Integrins 3 and 5, Secreted phosphoprotein1 and Sarcoglycan ,. No change in the expression of , Actin was observed while the expression of , Integrin 2 was significantly suppressed. Conclusions:, ETOH had no effect on NPC apoptosis but, resulted in more rapid coalescence and increased volume of neurospheres. Additionally, the expression of genes associated with cell adhesion was significantly altered. ETOH induced changes in NPC surface adhesion interactions may underlie aspects of neurodevelopmental abnormalities in FASD. [source]


    Ethanol Tolerance Caused by slowpoke Induction in Drosophila

    ALCOHOLISM, Issue 5 2006
    Roshani.
    Background: The large-conductance calcium-activated potassium channel encoded by the slowpoke gene has recently been implicated in the ethanol response. Caenorhabditis elegans carrying mutations in this gene have altered ethanol sensitivity and Drosophila mutant for this gene are unable to acquire rapid tolerance to ethanol or anesthetics. In Drosophila, induction of slowpoke expression has been linked to anesthetic resistance. Methods: We used Drosophila as a model system to examine the relationship between slowpoke expression and ethanol tolerance. Real-time PCR and a reporter transgene were used to measure slowpoke induction after ethanol sedation. An inducible slowpoke transgene was used to manipulate slowpoke levels in the absence of ethanol sedation. Results: Ethanol sedation increased transcription from the slowpoke neural promoters but not from the slowpoke muscle/tracheal cell promoters. This neural-specific change was concomitant with the appearance of ethanol tolerance, leading us to suspect linkage between the two. Moreover, induction of slowpoke expression from a transgene produced a phenotype that mimics ethanol tolerance. Conclusions: In Drosophila, ethanol sedation induces slowpoke expression in the nervous system and results in ethanol tolerance. The induction of slowpoke expression alone is sufficient to produce a phenotype that is indistinguishable from true ethanol tolerance. Therefore, the regulation of the slowpoke BK-type channel gene must play an integral role in the Drosophila ethanol response. [source]


    Novel pharmacogenetic markers for treatment outcome in azathioprine-treated inflammatory bowel disease

    ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2009
    M. A. SMITH
    Summary Background, Azathioprine (AZA) pharmacogenetics are complex and much studied. Genetic polymorphism in TPMT is known to influence treatment outcome. Xanthine oxidase/dehydrogenase (XDH) and aldehyde oxidase (AO) compete with TPMT to inactivate AZA. Aim, To assess whether genetic polymorphism in AOX1, XDH and MOCOS (the product of which activates the essential cofactor for AO and XDH) is associated with AZA treatment outcome in IBD. Methods, Real-time PCR was conducted for a panel of single nucleotide polymorphism (SNPs) in AOX1, XDH and MOCOS using TaqMan SNP genotyping assays in a prospective cohort of 192 patients receiving AZA for IBD. Results, Single nucleotide polymorphism AOX1 c.3404A > G (Asn1135Ser, rs55754655) predicted lack of AZA response (P = 0.035, OR 2.54, 95%CI 1.06,6.13) and when combined with TPMT activity, this information allowed stratification of a patient's chance of AZA response, ranging from 86% in patients where both markers were favourable to 33% where they were unfavourable (P < 0.0001). We also demonstrated a weak protective effect against adverse drug reactions (ADRs) from SNPs XDH c.837C > T (P = 0.048, OR 0.23, 95% CI 0.05,1.05) and MOCOS c.2107A > C, (P = 0.058 in recessive model, OR 0.64, 95%CI 0.36,1.15), which was stronger where they coincided (P = 0.019). Conclusion, These findings have important implications for clinical practice and our understanding of AZA metabolism. [source]


    Quantitative detection of hepatitis B virus DNA in serum by a new rapid real-time fluorescence PCR assay

    JOURNAL OF VIRAL HEPATITIS, Issue 6 2001
    R. Jardi
    A sensitive and accurate HBV DNA quantification assay is essential for monitoring hepatitis B virus (HBV) replication. This study evaluated a real-time PCR method performed in the LightCyclerTM analyser for quantitative HBV DNA assay. HBV DNA results with this method were compared with those obtained using a branched-chain DNA (bDNA) solution hybridization assay. Real-time PCR was performed using two adjacent fluorescently labelled probes and primers corresponding to the HBV core gene. The same standard employed in the bDNA assay was used for calibration. Serum samples came from 193 HBV surface antigen (HBsAg)-positive patients (34 HBV e antigen (HBeAg)-positive and 93 with antibody to HBeAg (anti-HBe)), and 66 asymptomatic HBV carriers. In addition, we analysed serum samples from 8 anti-HBe-positive patients who had been receiving lamivudine treatment for more than three years. A linear standard curve was seen in the range from 103 to 108 copies/mL. In the reproducibility analysis, intra-assay coefficient of variation (CVs) at two known HBV DNA concentrations were 4% and 2% and interassay CVs were 6% and 4%. The median of serum HBV DNA by real-time PCR was 9.2 × 108 copies/mL in HBeAg-positive patients with persistently elevated alanine aminotransferase (ALT) levels, 1.3 × 107 copies/mL in anti-HBe-positive cases with persistently elevated ALT levels, 3.7 × 104 copies/mL in anti-HBe-positive patients with fluctuating ALT levels and 104 copies/mL in asymptomatic HBV carriers. The differences in HBV DNA levels among the various groups studied were statistically significant (P < 0.05). The cut-off between chronic hepatitis patients and asymptomatic carriers was found to be at a serum HBV DNA concentration of 5 × 104 copies/mL. Of the 109 serum samples with a viral load < 7.5 × 105 (negative by bDNA assay) 44 (40%) were positive by real-time PCR: 24 (56%) chronic hepatitis and 20 (33%) asymptomatic carriers. There was a positive association between HBV DNA levels determined by real-time PCR and ALT levels (P < 0.05), which was not observed with the bDNA assay for HBV DNA quantification. At 12 months of lamivudine treatment, 6 patients (75%) showed HBV DNA levels < 5 × 104 copies/mL (range < 103,2 × 103), significantly lower than at baseline. At 36 months, 2 of 8 (25%) showed HBV DNA levels persistently lower than 5 × 104 copies/mL (1.7 × 103, 6 × 103). The LightCycler quantitative real-time PCR is a practical, sensitive, reproducible single-tube assay with a wide dynamic range of detection. The assay is automatic except for DNA extraction and the running time is only 70 min. The LightCycler real-time PCR is useful for identifying different states of HBV infection and for evaluating the efficacy of viral therapy. [source]


    Carriage, quantification, and predominance of methanogens and sulfate-reducing bacteria in faecal samples

    LETTERS IN APPLIED MICROBIOLOGY, Issue 1 2006
    J.A. Stewart
    Abstract Aims:, To determine carriage rates and densities of methanogens and sulfate-reducing bacteria in adults and children using molecular methods, and to also determine if a reciprocal relationship exists between these organisms. Methods and Results:, Real-time PCR was used to detect and quantify methanogens and sulfate-reducing bacteria. Real-time PCR was more sensitive than breath methane measurements. Real-time PCR assays were applied to faecal DNA samples collected from 40 children and 12 adults. Methanogens were present in 25% of the children and 42% of the adults studied, and sulfate-reducing bacteria were detected in 15% of the children and 58% of the adults. High levels of sulfate-reducing bacteria were found in two methanogenic adults. Conclusions:, Carriage rates and densities of methanogens and sulfate-reducing bacteria are greater in adults than in children. Competition does not necessarily lead to the predominance of one group in the faecal microflora. Significance and Impact of the Study:, This study describes sensitive, molecular assays that could be used to monitor these organisms in gastrointestinal disease. Therapeutic exclusion of one group from the bowel would not necessarily lead to the expansion of the other, as there does not appear to be a reciprocal relationship between these groups. [source]