Objective To compare the differences of chromosome aberration and Rb 1 gene mutation among 3 cloned cells of SO-Rb50 cell line of retinoblastoma. Methods 1.Three cell cloned strains named MC2, MC3, MC4 were isolated from SO-Rb50. 2. Gbanding and karyotype analysis were performed on the llth passage cells of the 3 cell strains.3.All exons and the promoter region of the Rb gene were detected by PCR-SSCP analysis in tumor cell DNA extracted from the 3 cell strains. Results 1.Both numerical and structural chromosomal aberrations could be observed in these 3 cell strains.Several kinds of structural chromosomal aberrations were observed.The chromosome aberrations in the same passage of different cell strains were different.Aberration of chromosome 13 was rare and the aberration feature was different in the 3 cell strains.Five marker chromosomes were identified.M1,t(1;1)qter-p35∷q24-ter could befound in all cell strains.Two of them M4 and M5,have not been reported in SO-Rb50 cell line previously.2.SSCP analysis of exon 24 showed that MC411 and MC3138 had abnormal band. Conclusions The characteristics of heterogeneity of the original tumor cell line SO-Rb50are still kept during a long-term culture in vitro and the cloned strains had dynamic changes during this period.Aberration of chromosome 13 is not the only cause of RB;aberration of chromosome 1,a commom event in some neoplasias as well as in SO-Rb50, plays a meaningful role in the immortalization of this cell line. (Chin J Ocul Fundus Dis, 1999, 15: 146-148)
【摘要】 目的 观察慢性粒细胞性白血病（chronic myelogenous leukemia， CML）急变（blast crisis，BC）患者罕见染色体异常的临床及实验室特点。 方法 2010年2月1例患者因咳嗽和高热来我院就诊，采用常规方法检查患者骨髓细胞，应用R显带技术和荧光原位杂交技术分析骨髓细胞核型。 结果 患者具有CML-BC的典型临床及实验室特点，同时核型出现不典型t（1；9；22）合并亚二倍体罕见核型异常，临床表现病情进展快，对伊马替尼疗效差，生存期短。 结论 慢性粒细胞性白血病患者在急变期出现伴不典型Ph染色体的亚二倍体复杂核型为高危核型，此类患者可能存在对伊马替尼的耐药，如能取得血液学缓解应尽早接受异基因骨髓造血干细胞移植，争取获得长期疗效。【Abstract】 Objective To report a case of chronic myelogenous leukemia (CML) blastic transformation into acute myelogenous leukemia with rare atypical hypodiploid t(1;9;22) complex chromosome abnormalities, and to analyze its clinical and laboratory characteristics. Methods A 47-year-old man was referred to our hospital due to cough and high fever in February 2010. We collected and analyzed the patient’s clinical materials, and performed chromosomal karyotype analysis with R-banding and fluorescence in situ hybridization (FISH). Results The patient demonstrated typical clinical and laboratory characteristics of blastic crisis of chronic myelogenous leukemia (CML-BC) and displayed rare atypical hypodiploid t(1;9;22) complex chromosome abnormalities. Meanwhile, the disease was rapidly progressive, with poor response to imatinib and had short overall survival. Conclusions CML-BC patients with hypodiploidy complex chromosome abnormalities are in high risk. They may show drug-resistance to imatinib. Thus, for this type of patients, once the hematological remission is achieved, allogeneic stem cell transplant should be performed as soon as possible to get better opportunity for long-term survival.
Human chromosomes karyotyping is an important means to diagnose genetic diseases. Chromosome image type recognition is a key step in the karyotyping process. Accurate and efficient identification is of great significance for automatic chromosome karyotyping. In this paper, we propose a model named segmentally recalibrated dense convolutional network (SR-DenseNet). In each stage of the model, the dense connected network layers is used to extract the features of different abstract levels of chromosomes automatically, and then the concatenation of all the layers which extract different local features is recalibrated with squeeze-and-excitation (SE) block. SE blocks explicitly construct learnable structures for importance of the features. Then a model fusion method is proposed and an expert group of chromosome recognition models is constructed. On the public available Copenhagen chromosome recognition dataset (G-bands) the proposed model achieves error rate of only 1.60%, and with model fusion the error further drops to 0.99%. On the Padova chromosome dataset (Q-bands) the model gets the corresponding error rate of 6.67%, and with model fusion the error further drops to 5.98%. The experimental results show that the method proposed in this paper is effective and has the potential to realize the automation of chromosome type recognition.