The Experts below are selected from a list of 9132 Experts worldwide ranked by ideXlab platform

Nataša Todorović-raković - One of the best experts on this subject based on the ideXlab platform.

  • Detection of c-myc amplification in formalin-fixed paraffin-embedded tumor tissue by chromogenic in situ hybridization (CISH).
    Methods in molecular biology (Clifton N.J.), 2013
    Co-Authors: Nataša Todorović-raković
    Abstract:

    In situ hybridization (ISH) allows evaluation of genetic abnormalities, such as changes in chromosome number, chromosome translocations or gene amplifications, by hybridization of tagged DNA (or RNA) probes with complementary DNA (or RNA) sequences in interphase nuclei of target tissue. However, chromogenic in situ hybridization (CISH) is also applicable to formalin-fixed, paraffin-embedded (FFPE) tissues, besides metaphase chromosome spreads. CISH is similar to fluorescent in situ hybridization (FISH) regarding pretreatments and hybridization protocols but differs in the way of visualization. Indeed, CISH signal detection is similar to that used in immunohistochemistry, making use of a peroxidase-based chromogenic reaction instead of fluorescent dyes. In particular, tagged DNA probes are indirectly detected using an enzyme-conjugated antibody targeting the tags. The enzymatic reaction of the chromogenic substrate leads to the formation of strong permanent brown signals that can be visualized by Bright-Field Microscopy at 40 × magnification. The advantage of CISH is that it allows the simultaneous observation of gene amplification and tissue morphology and the slides can be stored for a long time.

Christopher J De Jonge - One of the best experts on this subject based on the ideXlab platform.

  • simple determination of human sperm dna fragmentation with an improved sperm chromatin dispersion test
    Fertility and Sterility, 2005
    Co-Authors: Jose Luis Fernandez, Lourdes Muriel, Vicente Goyanes, Enrique Segrelles, J Gosalvez, Maria Enciso, Marie Lafromboise, Christopher J De Jonge
    Abstract:

    Objective To improve the sperm chromatin dispersion (SCD) test and develop it as a simple kit (Halosperm ® kit) for the accurate determination of sperm DNA fragmentation using conventional Bright-Field Microscopy. Design Method development, comparison, and validation. Setting Medical genetics laboratory, academic biology center, and reproductive medicine centers. Patient(s) Male infertility patients attending the Reproductive Medicine Center. A varicocele patient and a group of nine fertile subjects. Intervention(s) None. Main Outcome Measure(s) [1] The quality of chromatin staining in relaxed sperm nuclear halos and tail preservation; [2] SCD scoring reproducibility; [3] comparison with the sperm chromatin structure assay in 45 samples; [4] frequency of sperm with DNA fragmentation after incubation with increasing doses of the nitric oxide donor sodium nitroprusside and in sperm samples for 9 fertile men, 46 normozoospermic patients, 23 oligoasthenoteratozoospermic patients, and a subject with varicocele. Result(s) The sperm nuclei with DNA fragmentation, either spontaneous or induced, do not produce or show very small halos of DNA loop dispersion after sequential incubation in acid and lysis solution. The improved SCD protocol (Halosperm ® kit) results in better chromatin preservation, therefore highly contrasted halo images can be accurately assessed using conventional Bright-Field Microscopy after Wright staining. Moreover, unlike in the original SCD procedure, the sperm tails are now preserved, making it possible to unequivocally discriminate sperm from other cell types. The χ 2 test did not detect significant differences in the mean number of sperm cells with fragmented DNA as scored by four different observers. The intraobserver coefficient of variation for the estimated percentage of spermatozoa with fragmented DNA ranged from 6% to 12%. There was good correlation between the SCD and the sperm chromatin structure assay DNA fragmentation index (intraclass correlation coefficient R: 0.85; percent DNA fragmentation index mean difference: 2.16 significantly higher for SCD). Using the Halosperm ® ® kit, a dose-dependent increase in sperm DNA damage after sodium nitroprusside incubation was detected. The percentage of sperm cells with fragmented DNA in the fertile group was 16.3 ± 6.0, in the normozoospermic group, 27.3 ± 11.7, and in the oligoasthenoteratozoospermic group, 47.3 ± 17.3. In the varicocele sample, an extremely high degree of nuclear disruption was detected in the population of sperm cells with fragmented DNA. Conclusion(s) The improved SCD test, developed as the Halosperm ® kit, is a simple, cost effective, rapid, reliable, and accurate procedure, for routinely assessing human sperm DNA fragmentation in the clinical andrology laboratory.

Leiguang Wang - One of the best experts on this subject based on the ideXlab platform.

  • Measurement of sperm DNA fragmentation using Bright-Field Microscopy: comparison between sperm chromatin dispersion test and terminal uridine nick-end labeling assay
    Fertility and sterility, 2009
    Co-Authors: Zhang Lihong, Yi Qiu, Kehua Wang, Qiuju Wang, Guozhen Tao, Leiguang Wang
    Abstract:

    Objective To compare sperm chromatin dispersion (SCD) test with terminal deoxynucleotidyle transferase-mediated terminal uridine nick-end labeling (TUNEL) assay in assessing DNA fragmentation in human sperm through Bright-Field Microscopy. Design Prospectively designed, side-by-side comparative study. Setting Medical genetics laboratory in a provincial research institution. Patient(s) Sixty male patients presented for infertility evaluation and 30 fertile, volunteer sperm donors. Intervention(s) Semen analysis, SCD test, and TUNEL assay on the same semen sample and on the same spermatozoa. Main Outcome Measure(s) Sperm DNA fragmentation, determined by SCD test score or TUNEL assay score. Result(s) Sperm chromatin dispersion test and TUNEL assay identified similar proportions of sperm cells with DNA fragmentation in the same semen samples. When the SCD test and TUNEL assay were performed simultaneously on the same spermatozoa, TUNEL-negative sperm showed a large halo, whereas TUNEL-positive sperm showed no halo after Diff-Quik staining. However, in some sperm cells, DNA damage was detected by the SCD test but not by the TUNEL assay. Conclusion(s) Sperm chromatin dispersion test and TUNEL assay are both effective in detecting sperm DNA damage. Using Bright-Field Microscopy, the SCD test appears to be more sensitive than the TUNEL assay.

Carlos Wilson Gomes Lopes - One of the best experts on this subject based on the ideXlab platform.

  • experimental transmission of cryptosporidium baileyi apicomplexa cryptosporidiidae isolated of broiler chicken to japanese quail coturnix japonica
    Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia , 2005
    Co-Authors: Sergian V Cardozo, Carlos Wilson Gomes Lopes
    Abstract:

    In this work, oocysts of Cryptosporidium baileyi were isolated and identified in broiler chickens from three different Municipalities of the State of Rio de Janeiro, where they were isolated and identified by using the centrifuge- flotation technique associated to Bright-Field. Staining techniques, such as: modified Ziehl-Neelsen and safranin-methylene blue, were carried out to confirm natural infection. Oocysts of C. baileyi from broiler chickens were able to infect Coccidia-free Japanese quails, by observation of endogenous stages at histological sections, and the elimination of oocysts in the feces with prepatent period of seven days and patent period of 21 days after infection. Oocysts of C. baileyi from broiler chickens and Japanese quails were similar on Bright-Field Microscopy. With respect to the staining techniques used in this research, all of them left to significant changes in length and width of oocysts, but shape indexes were maintained. Bright-Field Microscopy was the best technique for oocysts comparison shed by broiler chickens and Japanese quail because of no different among oocysts were observed.

  • transmissao experimental de cryptosporidium baileyi apicomplexa cryptosporidiidae isolado de frango de corte a codorna japonesa coturnix japonica
    Revista Brasileira De Parasitologia Veterinaria, 2005
    Co-Authors: Sergian V Cardozo, Walter Leira Teixeira Filho, Carlos Wilson Gomes Lopes
    Abstract:

    2 ABSTRACT: - CARDOZO, S.V.; TEIXEIRA FILHO, W.L.; LOPES, C.W.G. (Experimental transmission of Cryptosporidum baileyi (Apicomplexa: Cryptosporidiidae) isolated of broiler chicken to Japanese quail (Coturnix japonica)). Transmissao experimental de Cryptosporidium baileyi (Apicomplexa: Cryptoporidiidae) isolado de frango de corte a codorna japonesa. Revista Brasileira de Parasitologia Veterinaria, v. 14, n. 3, p. 119-124, 2005. Universidade Federal Rural do Rio de Janeiro, Departamento de Parasitologia Animal, Km 7 da BR 465, Seropedica, RJ, Brazil, 23890-000. E-mail: lopescwg@ufrrj.br In this work, oocysts of Cryptosporidium baileyi were isolated and identified in broiler chickens from three different Municipalities of the State of Rio de Janeiro, where they were isolated and identified by using the centrifuge- flotation technique associated to Bright-Field. Staining techniques, such as: modified Ziehl-Neelsen and safranin- methylene blue, were carried out to confirm natural infection. Oocysts of C. baileyi from broiler chickens were able to infect Coccidia-free Japanese quails, by observation of endogenous stages at histological sections, and the elimination of oocysts in the feces with prepatent period of seven days and patent period of 21 days after infection. Oocysts of C. baileyi from broiler chickens and Japanese quails were similar on Bright-Field Microscopy. With respect to the staining techniques used in this research, all of them left to significant changes in length and width of oocysts, but shape indexes were maintained. Bright-Field Microscopy was the best techinique for oocysts comparison shed by broiler chickens and Japanese quail because of no different among oocysts were observed.

Michel Daudon - One of the best experts on this subject based on the ideXlab platform.

  • Advances in the identification of calcium carbonate urinary crystals
    Clinica Chimica Acta, 2021
    Co-Authors: Vincent Frochot, Vincent Castiglione, Ivan Lucas, Jean-philippe Haymann, Emmanuel Letavernier, Dominique Bazin, Giovanni Fogazzi, Michel Daudon
    Abstract:

    The examination of the urinary sediment of a 64-year-old woman showed the presence of three different types of crystals, all with unusual morphology, which could not be identified with Bright Field Microscopy, polarized light, and the knowledge of urine pH (7.5). The use of microscopic infrared spectroscopy, Raman spectroscopy and energy dispersive X-ray spectroscopy led to the identification of the three types of crystals as calcite, vaterite and aragonite, which are all variants of calcium carbonate crystals. This paper confirms the complex morphology and nature that urinary crystals may at times have and the utility of advanced infrared spectroscopy techniques for their identification.