Preliminary study on dicentric chromosome identification algorithm based on artificial intelligence technology / 中华放射医学与防护杂志

Objective:To explore artificial intelligence technology and propose an algorithm for automatic identification of dicentric chromosomes to realize fast and high-throughput biodosimetry. In order to solve the time-consuming and laborious problem of manual analysis of dicentric chromosomes.Methods:Combining artificial intelligence technology and image processing technology, based on MATLAB software, algorithms like image preprocessing, threshold segmentation algorithm, binarization processing, area identification algorithm, convolutional neural network algorithm and double centripetal recognition algorithm were applied. A fuzzy membership function was defined to describe the degree of each chromosome belonging to a dicentric chromosome, and the discrimination threshold was set to realize the automatic identification of dicentric chromosomes.Results:Through the test on 1 471 chromosome images, compared with manual recognition, the detection rate of dicentric chromosomes cells of this algorithm reached 70.7%.Conclusions:This algorithm method carries out a preliminary study on the automatic identification of dicentric chromosomes with good result.

Observation on chromosome aberration of peripheral blood lymphocytes in children with vascular diseases after interventional procedure / 中华放射医学与防护杂志

Objective:To evaluate the effect of ionizing radiation on chromosome aberration of peripheral blood lymphocytes in children with vascular interventional procedure.Methods:The chromosome aberration of peripheral blood lymphocytes was analyzed before and after vascular interventional procedure to assess the effect of low-dose ionizing radiation on chromosomes. Peripheral blood (PB) was collected using heparin as an anticoagulant from 26 patients before and after (within 10 minutes) vascular interventional surgery. Informed consent was obtained from the patients′ parents.Results:Dicentric + centric ring (dic+ r) formation increased significantly ( U=647, P<0.01) in peripheral blood lymphocytes of children after interventional operation. No correlation was observed between the rate of dic+ r and the cumulative dose (CD), dose area product (DAP), age, body weight, gender and the estimated effective dose E ( P>0.05). There was no significant difference in dic+ r rate of children between different genders, ages and lesion sites ( P>0.05). The dic+ r rate after interventional operation exceeded 40×10 -3 in 4 of 26 cases with the highest of 95.83×10 -3. Conclusions:The ionizing radiation during children′s vascular interventional procedure might lead to the increase of chromosome aberration of peripheral blood lymphocytes and some children are abnormally sensitive. Great attention should be paid to the justification and radiation protection during interventional procedure for children.

Dose Estimation Curves Following In Vitro X-ray Irradiation Using Blood From Four Healthy Korean Individuals

Cytogenetic dosimetry is useful for evaluating the absorbed dose of ionizing radiation based on analysis of radiation-induced chromosomal aberrations. We created two types of in vitro dose-response calibration curves for dicentric chromosomes (DC) and translocations (TR) induced by X-ray irradiation, using an electron linear accelerator, which is the most frequently used medical device in radiotherapy. We irradiated samples from four healthy Korean individuals and compared the resultant curves between individuals. Aberration yields were studied in a total of 31,800 and 31,725 metaphases for DC and TR, respectively, obtained from 11 X-ray irradiation dose-points (0, 0.05, 0.1, 0.25, 0.5, 0.75, 1, 2, 3, 4, and 5 Gy). The dose-response relationship followed a linear-quadratic equation, Y=C+αD+βD², with the coefficients C=0.0011 for DC and 0.0015 for TR, α=0.0119 for DC and 0.0048 for TR, and β=0.0617 for DC and 0.0237 for TR. Correlation coefficients between irradiation doses and chromosomal aberrations were 0.971 for DC and 0.6 for TR, indicating a very strong and a moderate correlation, respectively. This is the first study implementing cytogenetic dosimetry following exposure to ionizing X-radiation.

Study on the automatic analysis of dicentric chromosome biodosimetry / 中华放射医学与防护杂志

Objective To investigate a dose response curve based on a genetic workstation with automatic analysis system of dicentric chromosome assay (DCA) for establishing a high speed dose estimation method.Methods Peripheral blood from three healthy volunteers was irradiated in vitro using 60Co γ-rays,and then lymphocytes were cultured and fixed on slides using the standard protocol for DCA.Dicentric chromosome in metaphase cells was analyzed automatically with the genetic workstation and confirmed manually,and the dose response curve of automated dicentric chromosome was fitted.Dicentric chromosome of another peripheral blood sample irradiated with different doses was manually analyzed to verify the accuracy of the above automated DCA.Results The yield of automated DCA was well fitted by an equation Y =0.018 06D2 + 0.012 79D + 0.000 489 1 with a correlation coefficient R2 =0.961.The biological dose of radiation could be accurately estimated by this dose response curve within a few minutes.Conclusions We had successfully established a new dosimetry method by analyzing dicentric chromesome automatically,which can save a lot of manual analysis time and hence has important significance for emergency rescue in nuclear accidents.

A Case of dic (1:15) (p11;p11) with t(9:22) (q34:q11) in B-ALL.

B cell ALL is a subtype of Acute lymphoblastic leukemia (ALL). Till date, 3 dicentric’s: dic (7;9), dic(9;12) and dic(9;20) with t(9;22) were reported in B- ALL . The hematological profile revealed a white blood cell count of 324.3 X10³/mm3 with 74% blasts, a hemoglobin level of 6.2 g/dl and a platelet count of 50X109 /mm. Trephine biopsy revealed proliferations of blasts which are medium sized to large and had vesicular nuclei with indented nucleoli. The biochemical parameters were normal except elevated liver AST (67U/L);ALT(121U/L);GGTP(159U/L), alkaline phosphatase (251U/L) profiles and renal urea (46mg/dl),Creatinine (1.446mg/dl) and sodium (135mEq/L). The patient was positive for the Immunophenotypic markers CD10/CD19/CD34/ CD33 by Flowcytometry. Diagnosis of B- ALL was made. To our knowledge this dic(1;15)(p11:p11) with t(9;22) (q34;q11) is the first kind of report in B-ALL. Further molecular studies are required to elucidate the pathogenesis and prognostic significance of dic(1;15) in leukemia.

Inestabilidad cariológica durante la formación de células madres del polen en Aloe vera (Aloaceae)

Con el objetivo de esclarecer la posible existencia de anomalías citogenéticas que aminoren la fertilidad del polen de Aloe vera, se analizó la etapa de proliferación celular que lleva a la formación de células madres del polen (CMPs). Se recolectaron botones florales (BF) en 25 plantas de una población ubicada a 10°34’15’’ N, 64°12’08’’ W, los cuales fueron fijados en Carnoy I por 24 h y almacenados en etanol (70 % v/v). Las observaciones se realizaron en preparaciones temporales obtenidas por la tinción del contenido de las anteras suspendidas en orceína acética (1.5 % p/v) por 5 minutos. De las 9 411 células analizadas, 17 % mostraron 1-8 puentes entre cromátidas hermanas, 13 % 1-7 micronúcleos de 0.9-4.8 µm, 8.1 % estaban unidas por puentes y 0.1 % no contenían cromatina. El resto de las células (61.8 %) presentó configuraciones aparentemente normales y sin variaciones morfométricas. La proliferación irregular de una fracción de CMPs (39.2 %) sugiere que las condiciones ambientales de la zona árida donde se realizaron los muestreos inducen inestabilidad cromosómica y cambios fisiológicos que afectan el normal desarrollo de la mitosis premeiótica, generando pérdida o adición de fragmentos, asociados a deficiencias y duplicaciones génicas.