Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
See detailDetection of biomarkers of pathogenic bacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
Ruelle, Virginie; Elmoualij, Benaïssa ULg; Zorzi, Willy ULg et al

in Lichtfouse, Eric; Schwarzbauer, Jan; Robert, Didier (Eds.) Environmental Chemistry : Green Chemistry and Pollutants in Ecosystems (2005)

In recent years, various mass spectrometry procedures has been developed for identifying bacteria. The accuracy and speed with which data can be obtained by Matrix-assisted laser Desorption/Ionization ... [more ▼]

In recent years, various mass spectrometry procedures has been developed for identifying bacteria. The accuracy and speed with which data can be obtained by Matrix-assisted laser Desorption/Ionization Time-of-flight Mass Spectrometry (MALDI-TOF-MS) make this an advantageous technique for environmental monitoring. However, minor variations in the sample preparation can influence the mass spectra significantly. In the present study, we have introduced a procedure to prepare bacteria by microextraction and we have optimized experimental parameters for rapid identification by MALDI-TOF-MS of whole bacterial cells isolated from environmental samples such as wastewater and soil. [less ▲]

Detailed reference viewed: 62 (32 ULg)
Full Text
Peer Reviewed
See detailDetection of BLV in frozen semen samples by PCR assay
Dus Santos, M.J.; Rodriguez, Sabrina ULg; Wigdorovitz, A. et al

in AIDS Research and Human Retroviruses (2007, April 23), 23(4), 651

Detection of BLV in frozen semen samples by PCR assay Dus Santos Maria Jose; Rodriguez Sabrina; Wigdorovitz Andrés; Trono Karina Instituto de Virología, CICVyA, INTA-Castelar. CC 77. Buenos Aires ... [more ▼]

Detection of BLV in frozen semen samples by PCR assay Dus Santos Maria Jose; Rodriguez Sabrina; Wigdorovitz Andrés; Trono Karina Instituto de Virología, CICVyA, INTA-Castelar. CC 77. Buenos Aires, Argentina. Detection of BLV in frozen semen samples by PCR assay María José Dus Santos, Sabrina Rodriguez, Andrés Wigdorovitz and Karina Trono. Instituto de Virología, CICVyA, INTA-Castelar. CC 77. Buenos Aires, Argentina mdussantos@cnia.inta.gov.ar The sanitary and economic impact of BLV infection is associated with the interference in the international movement of cattle and their germ plasm. Although experimental data support the improbability that semen from BLV-positive bulls could infect recipient cows, restriction for commercialization of semen from infected animals is still present. The objective of this work was to standardize a PCR assay to diagnose the presence of BLV genome and to describe the pattern of BLV detection in frozen semen samples. The developed methodology involves the amplification of an internal fragment of gag gene and posses a limit of detection of 60 viral particles. Additionally, a biological test in susceptible sheep was performed in order to evaluate the transmission of BLV genome by semen from seropositive animals. This data strongly suggest that semen from seropositive bulls that resulted negative by PCR can be used for artificial insemination (AI), accompanied by proper collection protocols. Frozen semen samples from 30 seropositive bulls were analyzed. It was possible to detect proviral DNA in 118 out of 545 samples. It was important to note that BLV genome detection occurred in several collections but in an alternated way with non detection periods. On the other hand, in 4 seropositive bulls, it was not possible to detect BLV genome in all the samples analyzed. The development of this PCR assay constitutes a valuable diagnostic tool to determine the BLV-free status of semen used for AI. Moreover, the results suggest that BLV could present an intermittent pattern of excretion. [less ▲]

Detailed reference viewed: 48 (0 ULg)
Full Text
Peer Reviewed
See detailDetection of BLV in frozen semen samples by PCR assay.
Rossich, L.; Gutiérrez, G.; Rodriguez, Sabrina ULg et al

Poster (2007, November 12)

Intermitent detection of BLV in frozen semen simples by PCR assay L. Rossich1, J. Gutierrez1, S. Rodriguez1, E. Lefebvre2, K. Trono1 and M. J. Dus Santos1 (1) Instituto de Virología, CICVyA, INTA-Castelar ... [more ▼]

Intermitent detection of BLV in frozen semen simples by PCR assay L. Rossich1, J. Gutierrez1, S. Rodriguez1, E. Lefebvre2, K. Trono1 and M. J. Dus Santos1 (1) Instituto de Virología, CICVyA, INTA-Castelar. CC 77. Buenos Aires, Argentina. (2) Centro de Inseminación Artificial La Elisa. Argentina. Introduction: The major route of transmission of BLV is horizontal by direct exposure to biological fluids contaminated with infected lymphocytes, mainly blood. Although viral antigens and proviral DNA has been identified in semen, milk and colostrums, natural transmission through these secretions has not been demonstrated. The sanitary and economic impact of BLV infection is associated with the interference in the international movement of cattle and their germ plasm. Although experimental data support the improbability that semen from BLV-positive bulls could infect recipient cows, restriction for commercialization of semen from infected animals is still present[1-6]. Since there is no vaccine or treatment available, eradication and control of the disease is exclusively based on early diagnostic and segregation of infected animals. In this context the specificity and sensitivity of the diagnostic test used is a critical point. We have previously developed a PCR assay with high sensitivity and specificity to detect BLV genome in frozen semen samples. The objective of this work was to study the detection of BLV in semen. Material & methods: Samples: Serum, whole blood and semen samples were obtained from CIALE (Artificial Insemination Centre La Elisa, Capitan Sarmiento, Buenos Aires, Argentina) Serology: The agar gel immunodifussion (AGID) test kit used to detect antibodies to BLV was produced by the Faculty of Veterinary, La Plata University, Argentina. An indirect ELISA using recombinant p24 as antigen was used to detect antibodies to BLV. This assay has been completely developed and standardized in the Institute of Virology, INTA-Castelar, Buenos Aires, Argentina. Detection of proviral DNA: DNA was extracted from PMBCs (purified from whole blood) and semen samples (fresh and straw). PCR assays that amplified a region of genes pol and gag and a nPCR that amplified a region of gene env were developed. Results: Two PCR assays were standardized for detecting BLV genome in semen and PMBC. The limit of detection of viral particles was assessed by the addition of purified pBLV344 (a plasmid containing the complete BLV genome, kindly provided by Dr. Willems, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium) to DNA from semen or PMBCs of a seronegative bull. By gag-PCR and pol-PCR, it was possible to detect 60 viral particles, using bromide staining after electrophoresis separation of DNA. In order to increase analytical sensitivity, a nested-PCR was developed which amplified a region of env gene. The n-PCR was able to detected 6 viral particles. Assessment of the limit of detection was highly repetitive under the standardized conditions. Frozen semen samples from 30 seropositive bulls were remitted to the laboratory and analyzed in the period 2005-2007. It was possible to detect proviral DNA in 172 out of 862 samples. BLV genome detection occurred in several collections but in an alternated way with non detection periods. Fresh semen samples, straws and whole blood were also obtained from 5 seronegative and 5 seropositive bulls and tested together for the presence of BLV provirus. Results indicated that while detection of provirus was positive in PMBC from all seropositive bulls, detection of gag, pol and env genes in semen did not occurred in all the samples. Discussions & conclusions: The results obtained suggest that BLV could present an intermittent pattern of excretion. Further studies should be done to confirmed the results obtained and to establish why the presence of BLV provirus in semen is not constant. References : 1. Choi, K, et al. 2002. Vet Diagn Invest 14: 403-406. 2. Kaja, R. and Olson, C. 1982. Theriogenology 18: 107-112. 3. Miller, J. and Van Der Maaten, M. 1979. J Natl Cancer Inst 62; 425-428. 4. Monke, D. 1986. JAVMA 188 (8): 823-826. 5. Romero, C., et al. 1983. Tropical Animal Health and production. 15: 215-218. 6. Straub O. 1982. In: Fourth International Symposium of Bovine Leukosis. The Hague: Martinus Nijhoff Publishers: 299-308. [less ▲]

Detailed reference viewed: 37 (0 ULg)
Full Text
Peer Reviewed
See detailDetection of bone sialoprotein in human (pre)neoplastic lesions of the uterine cervix
Detry, Cédric ULg; Waltregny, David ULg; Quatresooz, Pascale ULg et al

in Calcified Tissue International (2003), 73(1), 9-14

Bone sialoprotein (BSP) is a secreted glycoprotein primarily found in the mineral compartment of developing bones. BSP is detected in a variety of human cancers, particularly those that metastasize to the ... [more ▼]

Bone sialoprotein (BSP) is a secreted glycoprotein primarily found in the mineral compartment of developing bones. BSP is detected in a variety of human cancers, particularly those that metastasize to the skeleton. High expression of BSP in breast and prostate primary carcinomas is associated with progression and bone metastases development. Since squamous cell carcinoma (SCCs) of the uterine cervix also frequently metastasizes to bone, we investigated whether BSP is expressed in human cervical cancer. We examined BSP expression in cervical tissue samples from 47 patients, including 19 normal tissues, 20 squamous intraepithelial lesions (SILs) (9 low and 11 high grade) and 8 invasive SCCs. BSP protein expression was evaluated by the immunophosphatase technique using a BSP polyclonal antibody in paraffin-embedded cervical biopsies. The abundance of BSP protein was significantly higher in invasive SCCs and high grade SILs than in normal cervix tissue samples and low grade SILs, which showed no or a low level of anti-BSP immunoreactivity. In situ hybridization experiments performed on representative cervix invasive SCCs frozen sections revealed that BSP transcripts were detectable in these lesions. Our study demonstrates that BSP expression is a common feature in high grade SILs and invasive SCCs of the uterine cervix. The prognostic value of BSP detection in these lesions and the potential role of BSP as an angiogenic factor in this type of cancer are currently under investigation. [less ▲]

Detailed reference viewed: 68 (10 ULg)
Peer Reviewed
See detailDetection of Bone Sialoprotein in Human Breast Cancer Tissue and Cell Lines at Both Protein and Messenger Ribonucleic Acid Levels
Bellahcene, Akeila ULg; Antoine, Nadine ULg; Clausse, N. et al

in Laboratory Investigation : Journal of Technical Methods & Pathology (1996), 75(2), 203-10

The recent demonstration that bone sialoprotein (BSP) can be detected in human breast cancer tissue by immunoperoxidase suggests that this phosphoprotein is ectopically expressed by malignant mammary ... [more ▼]

The recent demonstration that bone sialoprotein (BSP) can be detected in human breast cancer tissue by immunoperoxidase suggests that this phosphoprotein is ectopically expressed by malignant mammary epithelial cells. Its detection in human breast cancer cells raises questions about its potential role(s) during breast cancer progression. Because BSP is secreted and is present in the serum, the positivity of breast cancer cells for BSP could have been the result of an uptake of the circulating phosphoprotein by the cells rather than of an intrinsic expression. We examined the expression of BSP at both the protein and mRNA levels in nine human breast cancer samples as well as in three human breast cancer cell lines (MCF-7, T47-D, and MDA-MB-231) using immunohistochemistry, flow cytometric analysis, immunoblot, and reverse-transcriptase PCR. BSP was detected at both protein and mRNA levels in human breast cancer tissue and in the three human breast cancer cell lines. Using a specific polyclonal anti-BSP antibody, we showed by both fluorescence-activated cell sorter analysis and immunohistochemistry experiments that all of the human breast cancer cell lines studied express BSP. This was localized at the cell surface and in the cytosol of the estrogen receptor-positive MCF-7 and T47-D cell lines, whereas it was detected only in the cytosol of the estrogen receptor-negative MDA-MB-231 cells. Using the same polyclonal anti-BSP antibody, we were able to identify an approximately 97-kd band on total protein extracts from the three cell lines by immunoblotting. Reverse-transcriptase PCR reactions using specific oligonucleotides performed on total RNA of nine human breast cancer biopsy samples and the three cell lines demonstrated the presence of BSP mRNA in all of the samples examined. This study is the first demonstration that human malignant breast epithelial cell lines express BSP at the protein and mRNA levels. Our study identified MCF-7, T47-D, and MDA-MB-231 cells as useful models for the examination of the molecular mechanisms involved in the ectopic expression of BSP in breast malignant lesions. [less ▲]

Detailed reference viewed: 22 (0 ULg)
Peer Reviewed
See detailDetection of bovine leukaemia virus antibodies. Use of monoclonal antibody to increase sensitivity in an ELISA test.
Portetelle, Daniel ULg; Bruck, C.; Mammerickx, M. et al

in Archives Internationales de Physiologie et de Biochimie (1982), 90(3),

Detailed reference viewed: 8 (0 ULg)
Peer Reviewed
See detailDetection of Bovine Leukemia Virus antibodies : use of monoclonal antibody to increase sensitivity and specificity of the ELISA test.
Portetelle, Daniel ULg; Bruck, Claudine; Mammerickx, Marc et al

in Straub, O. C. (Ed.) Proceedings of the Fifth International Symposium on bovine leukosis (1984)

Detailed reference viewed: 16 (0 ULg)
Full Text
Peer Reviewed
See detailDetection of bovine leukemia virus specific antibodies using recombinant p24-ELISA.
Gutierrez, G.; Alvarez, I.; Fondevila, N. et al

in Veterinary Microbiology (2009), 137(3-4), 224-34

We developed an indirect ELISA test (rp24-ELISA) for the detection of antibodies against the p24 capsid protein of bovine leukemia virus (BLV) in bovine serum samples. A recombinant p24 (rp24) was ... [more ▼]

We developed an indirect ELISA test (rp24-ELISA) for the detection of antibodies against the p24 capsid protein of bovine leukemia virus (BLV) in bovine serum samples. A recombinant p24 (rp24) was expressed in the Escherichia coli expression system, purified in a nickel charged resin and used as antigen in the ELISA test. A cut-off point was established considering the distribution of reactivity values obtained by rp24-ELISA on a set of 555 field serum samples that were stated as double positive (DP) or double negative (DN) by the combination of commercial agar gel immunodiffusion (AGID) assay and gp51-ELISA tests results. The rp24-ELISA showed good concordance with the agar gel immunodiffusion assay, when 710 serum samples were analyzed. In addition, rp24-ELISA demonstrated to be a precise assay with good repeatability and reproducibility and a better analytical sensitivity than AGID. From 67 discordant rp24-ELISA-AGID sera, 4 negative reactors were from the DP group, 28 positive samples were from the DN group and 35 positive samples were stated as negative by AGID but positive by the gp51-ELISA. Samples from this last subgroup were sent to an OIE reference laboratory where 28 samples were stated as negative, 5 samples were stated as positive and 2 as inconclusive. Complete concordance with blind previous results from an international proficiency test panel confirmed the capability of the assay to discriminate between infected and non-infected animals. In conclusion, the rp24-ELISA developed and standardized demonstrated to have good analytical characteristics to be considered for screening of BLV. [less ▲]

Detailed reference viewed: 9 (4 ULg)
Full Text
See detailDetection of bright multiply imaged quasars by GAIA
Finet, François ULg

Scientific conference (2011, June 06)

Bright multiply imaged quasars offer unique tools to investigate the properties of the Universe as a whole (cosmological parameters), the astrophysical properties of the remote galaxies acting as ... [more ▼]

Bright multiply imaged quasars offer unique tools to investigate the properties of the Universe as a whole (cosmological parameters), the astrophysical properties of the remote galaxies acting as deflectors (i.e. their mass, extinction law, ...) as well as the structure of the background sources (accretion disk, central engine, etc.). Multiply imaged quasars will represent the most easily identified signature of lensing in GAIA observations. Several thousands of such cases are expected with J <=20. Furthermore, the complete QSO catalog which will be built from the GAIA observations will be very attractive and unique in order to study QSO evolution, large scale structures, intervening absorbers, the inertial frame, ... The aim of this presentation is to report about a realistic estimate of the expected number of bright multiply imaged quasars that will be detected by GAIA. [less ▲]

Detailed reference viewed: 23 (4 ULg)
Full Text
Peer Reviewed
See detailDetection of carbon stock change in agricultural soils using spectroscopic techniques
Stevens, Antoine; Van Wesemael, Bas; Vandenschrick, Grégoire et al

in Soil Science Society of America Journal (2006), 70(3, MAY-JUN), 844-850

Soil organic carbon (SOC) represents one of the major pools in the global C cycle. Therefore, even small changes in SOC stocks cause important CO, fluxes between terrestrial ecosystems and the atmosphere ... [more ▼]

Soil organic carbon (SOC) represents one of the major pools in the global C cycle. Therefore, even small changes in SOC stocks cause important CO, fluxes between terrestrial ecosystems and the atmosphere. However, SOC stocks are difficult to quantify accurately due to their high spatial variability. The aim of this paper is to evaluate the potential of Imaging Spectroscopy (IS) using the Compact Airborne Spectrographic Imager (CASI; 405-950 nm) and field spectroscopy with an Analytical Spectral Devices spectrometer (ASD; 350-2500 nm) to measure SOC content in heterogeneous agricultural soils. We used both stepwise and partial least square (PLS) regression analysis to relate spectral measurements to SOC contents. Standard Error of Prediction (SEP) for the ASD ranged from 2.4 to 3.3 g C kg(-1) depending on soil moisture content of the surface layer. Imaging spectroscopy performed poorly, mainly due to the narrow spectral range of the CASI. Tests using both the CASI and the Shortwave infrared Airborne Spectrographic Imager (SASI; 900-2500 nm) showed better results. The variation in soil texture and soil moisture content degrades the spectral response to SOC contents. Currently, SEP allows to detect a SOC stock change of 7.2-9.9 Mg C ha(-1) in the upper 30 cm of the soil, and is therefore still somewhat high in comparison with changes in SOC stocks as a result of management or land conversion (0.34.9 Mg C ha(-1) yr(-1)). A detailed SOC maps produced by IS reflected the patterns in SOC contents due to the recent conversion from grassland to cropland. [less ▲]

Detailed reference viewed: 27 (8 ULg)
Full Text
Peer Reviewed
See detailDetection of carbonyl fluoride in the stratosphere
Rinsland, C. P.; Zander, Rodolphe ULg; Brown, L. R. et al

in Geophysical Research Letters (1986), 13(8), 769--772

Detailed reference viewed: 5 (0 ULg)
Peer Reviewed
See detailDetection of Chloroplast DNA by Using Fluorescent Monoclonal Anti-Bromodeoxyuridine Antibody and Analysis of Its Fate During Zygote Formation in Chlamydomonas Reinhardtii
Munaut, Carine ULg; Dombrowicz, D.; Matagne, René-Fernand ULg

in Current Genetics (1990), 18(3), 259-63

A monoclonal anti-bromodeoxyuridine antibody conjugated to fluorescein was used to detect the chloroplast nucleoids after specific incorporation of bromodeoxyuridine (BUdR) into the chloroplast DNA of ... [more ▼]

A monoclonal anti-bromodeoxyuridine antibody conjugated to fluorescein was used to detect the chloroplast nucleoids after specific incorporation of bromodeoxyuridine (BUdR) into the chloroplast DNA of Chlamydomonas reinhardtii. The incorporation of BUdR was enhanced by simultaneous treatment with fluorodeoxyuridine (FUdR). The method was applied to analyze the fate of chloroplast DNA in zygotes resulting from mating between BUdR-treated gametes (mt+ or mt-) and untreated gametes of opposite mating-type. In crosses between wild-type strains, the nucleoids of mt+ origin remained in the large majority of zygotes whereas those of mt- origin most often disappeared within the first hours following copulation. In crosses of the type mat-3 mt+ x wild-type mt- (the mat-3 mutation permits a high transmission of chloroplast genes from the mt- parent), the nucleoids of mt- origin were generally not eliminated which indicates that the mat-3 mutation prevents the selective destruction of paternal chloroplast DNA in the zygote. [less ▲]

Detailed reference viewed: 14 (3 ULg)
Full Text
Peer Reviewed
See detailDetection of Citrus Psorosis Virus Using an Improved One-Step RT-PCR
Achachi, Asmae; Jijakli, Haissam ULg; El Fahime, Elmostafa et al

in Arabian Journal for Science and Engineering (2014)

Detailed reference viewed: 34 (1 ULg)
Full Text
Peer Reviewed
See detailDetection of Clostridium botulinum neurotoxins A and B in milk by ELISA and immuno-PCR at higher sensitivity than mouse bio-assay
Rajkovic, Andreja; Elmoualij, Benaïssa ULg; Fikri, Youssef et al

in Food Analytical Methods (2011), [Epub ahead of print]

Detailed reference viewed: 70 (10 ULg)
Peer Reviewed
See detailDetection of complement-dependent lytic antibodies in sera from bovine leukemia virus-infected animals.
Portetelle, Daniel ULg; Bruck, Claudine; Burny, Arsène et al

in Annales de Recherches Vétérinaires = Annals of Veterinary Research (1978), 9(4), 667-674

Detailed reference viewed: 9 (0 ULg)
Full Text
Peer Reviewed
See detailDetection of copy number variants in the horse genome and examination of their association with recurrent laryngeal neuropathy
Dupuis, Marie-Capucine; Zhang, Zhiyan ULg; Durkin, Keith ULg et al

in Animal Genetics (2013)

We used the data from a recently performed genome-wide association study using the Illumina Equine SNP50 beadchip for the detection of copy number variants (CNVs) and examined their association with ... [more ▼]

We used the data from a recently performed genome-wide association study using the Illumina Equine SNP50 beadchip for the detection of copy number variants (CNVs) and examined their association with recurrent laryngeal neuropathy (RLN), an important equine upper airway disease compromising performance. A total of 2797 CNVs were detected for 477 horses, covering 229 kb and seven SNPs on average. Overlapping CNVs were merged to define 478 CNV regions (CNVRs). CNVRs, particularly deletions, were shown to be significantly depleted in genes. Fifty-two of the 67 common CNVRs (frequency ! 1%) were validated by association mapping, Mendelian inheritance, and/or Mendelian inconsistencies. None of the 67 common CNVRs were significantly associated with RLN when accounting for multiple testing. However, a duplication on chromosome 10 was detected in 10 cases (representing three breeds) and two unphenotyped parents but in none of the controls. The duplication was embedded in an 8-Mb haplotype shared across breeds. [less ▲]

Detailed reference viewed: 31 (11 ULg)
Full Text
See detailDetection of counterfeit Viagra by Raman microspectroscopy imaging and multivariate analysis
Sacré, Pierre-Yves ULg; Deconinck, Eric; Saerens, Lien et al

Conference (2011, May 13)

Detailed reference viewed: 45 (4 ULg)