Preparation of the preliminary dose-effect calibration curve using the cytokinesis-blocking micronucleus assay in the human cytogenetics laboratory of the Health Research Institute
Description
Biological dosimetry (DB) consists of a series of techniques in which biomarkers associated with the effects of ionizing radiation (IR) such as micronuclei (MN) are used, which are very useful to assess whether a person is overirradiated since They allow an approximate calculation of the absorbed dose. The objective of this practice was the elaboration of a preliminary dose-effect calibration curve for gamma rays using the MN assay. This first stage is the basis for the calibration curve of the DB Service of the Health Research Institute (INISA). Between 2018 and 201, the following activities were carried out: 1) in vitro irradiation (with a Cobalt-60; 60Co source) of gamma rays in the Radiotherapy Service of the San Juan de Dios Hospital (HSJD) of nine samples of peripheral blood of a female volunteer, at nine different dose points (0.3 Gray (Gy), 0.5 Gy, 1Gy, 1.5 Gy, 2 Gy, 2.5 Gy, 3 Gy and 4 Gy) in which (0 Gy) is included as control to evaluate the donor's baseline; 2) culturing lymphocytes from irradiated blood using the cytokinesis blocked micronucleus (CBMN) assay and preparing cell smears including staining; and 3) analysis of MN using a light microscope. These last two activities were carried out in the INISA cytogenetics laboratories. For the elaboration of the curve, 2000 binucleated cells (BN) were analyzed for the first four doses and 1000 BN cells for the other five dose points for a total of 13000 BN cells. Subsequently, with the data resulting from the BN and MN cell count per dose, the Dose Estimate software was used to obtain the dose-effect calibration curve. The resulting curve had a linear-quadratic fit as expected (the higher the dose, the higher the frequency of MN) Y = 0.0081 (+/-0.0037) + 0.0026 (+/-0.0085) D + 0.0076 (± 0.0029 )D2; X2 = 27.5900; gl. = ; p = 0.6667; p values for the coefficients (z-test): p Α 0.3732, p α = 0.7716, p β = 0.0411. The calibration curve obtained is valuable preliminary work, which is expected to continue at INISA with the incorporation of a greater number and variety of donors, improving the staining technique for micronucleus reading
Availability note (English)
Available from Biblioteca Luis Demetrio Tinoco, Universidad de Costa Rica; Also available on line: http://repositorio.sibdi.ucr.ac.cr:8080/jspui/handle/123456789/16808Abstract (Spanish)
La dosimetria biologica (DB) consiste en una serie de tecnicas en las que se utilizaban biomarcadores asociados a los efectos de las radiaciones ionizantes (RI) como los micronucleos (MN), que son de gran utilidad para evaluar si una persona esta sobreirradiada ya que permiten hacer un calculo aproximado de la dosis absorbida. Esta practica tuvo como objetivo la elaboracion de una curva preliminar de calibracion dosis-efecto para rayos gamma utilizando el ensayo de MN. Esta primera etapa es la base para la curva de calibracion del Servicio de DB del Instituto de Investigaciones en Salud (INISA). Entre el 2018 y el 2019 se realizaron las siguientes actividades: 1) la irradiacion in vitro (con una fuente de Cobalto-60; 60Co) de rayos gamma en el Servicio de Radioterapia del Hospital San Juan de Dios (HSJD) de nueve muestras de sangre periferica de una voluntaria femenina, en nueve puntos de dosis distintos (0.3 Gray (Gy), 0.5 Gy, 1Gy, 1.5 Gy, 2 Gy, 2.5 Gy, 3 Gy y 4 Gy) en las que se incluye (0 Gy) como control para evaluar el basal de la donante; 2) el cultivo de linfocitos de la sangre irradiada utilizando el ensayo de micronucleos con bloqueo de la citocinesis (CBMN) y la preparacion de extensiones celulares incluyendo la tincion; y 3) el analisis de MN utilizando un microscopio de luz. Estas dos ultimas actividades se realizaron en los laboratorios de citigenetica del INISA. Para la elaboracion de la curve se analizaron 2000 celular binucleadas (BN) para las cuatro primeras dosis y 1000 celulas BN para los otros cinco puntos de dosis para un total de 13000 celulas BN. Posteriormente, con los datos resultantes del conteo de celulas BN y MN por dosis, se utilizo el software Dose Estimate para obtener la curva de calibracion dosis-efecto. La curva resultante tuvo un ajuste lineal-cuadratico segun lo esperado (a mayor dosis, mayor frecuencia de MN) Y = 0.0081 (+/-0.0037) + 0.0026 (+/-0.0085) D + 0.0076 (± 0.0029)D2; X2 = 27.5900; gl. = ; p = 0.6667; valores p para los coeficientes (z-test): p Α 0.3732, p α = 0.7716 p β = 0.0411. La curva de calibracion obtenida es un valioso trabajo preliminar, que se espera continuar en el INISA con la incorporacion de mayor cantidad y variedad de donantes, mejorando la tecnica de tincion para la lectura de los micronucleos. (autor)Additional details
Additional titles
- Original title (Spanish)
- Elaboracion de la curva preliminar de calibracion dosis-efecto utilizando el ensayo de micronucleos con bloqueo de la citocinesis en el laboratorio de citogenetica humana del Instituto de Investigacion en Salud
Identifiers
Publishing Information
- Imprint Place
- San Jose (Costa Rica)
- Imprint Pagination
- 46 p.
INIS
- Country of Publication
- Costa Rica
- Country of Input or Organization
- Costa Rica
- INIS RN
- 54010376
- Subject category
- S61: RADIATION PROTECTION AND DOSIMETRY; S46: INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY;
- Resource subtype / Literary indicator
- Thesis, Non-conventional Literature
- Descriptors DEI
- BIOLOGICAL MARKERS; CALIBRATION; CELL NUCLEI; DOSIMETRY; GAMMA RADIATION; IONIZING RADIATIONS; RADIATION EFFECTS
- Descriptors DEC
- CELL CONSTITUENTS; ELECTROMAGNETIC RADIATION; IONIZING RADIATIONS; RADIATIONS
Optional Information
- Notes
- Figs., charts., tabs., refs.