AIM:To investigate the histone modification changes of topoisomerase Ⅱα( TOPOⅡα) promoter regulatory factor Sp1 in the patients with chronic benzene poisoning .METHODS:The bone marrow samples were collect-ed from 25 chronic benzene poisoning cases and 25 controls.The chromatin immunoprecipitation assay was carried out to study the possible mechanism of TOPOⅡαpromoter regulatory factor Sp 1 expression changes .The mRNA expression of Sp1 was detected by RT-PCR.RESULTS:Compared with the controls , the histone H4 acetylation and histone H3 acetyla-tion of Sp1 in the chronic benzene poisoning patients significantly decreased (P<0.01), and histone H3K9 methylation level of Sp1 increased (P<0.01), but the histone H3K4 methylation level of SP1 was not obviously changed (P>0.05). The mRNA expression of Sp1 in the chronic benzene poisoning patients was significantly lower than that in the controls (P<0.05).CONCLUSION:In chronic benzene poisoning patients , the histone acetylation and methylation modification changes of TOPOⅡαpromoter regulatory factor Sp 1 accompanied with the changes of mRNA level are observed .Histone H4 and H3 acetylation and H3K9 methylation modification of Sp1 may play an important role in the benzene ’s hematopoiet-ic toxicities.

Objective To investigate the roles of fiberoptic bronchoscopy in diagnosis and treatment for infants with refractory and persistent wheezing. Methods From Jun. 2012 to Dec. 2013, 52 hospitalized children with age between four 4 months and 1 year old were recruited for ifberoptic bronchoscopy, who had been wheezing for at least four weeks and treated ineffectively with conventional anti-inlfammatory agents:budesonide and compound ipratropium bromide solution. Then, the pathogenesis of refractory and persistent wheezing was summarized based on clinical features, detection of CT imaging of three-dimensional airway reconstruction and cardiac CT, results of bronchoscopy inspection, and bronchoalveolar lavage lfuid culture. Results Among the 52 cases, 40 were with ground glass-like changes (76.92%) in pulmonary spiral CT testing, 4 with mosaic perfusion syndrome (7.69%), 8 with segmental pulmonary consolidation (15.38%), 8 with obstructive pulmonary emphysema (15.38%), and 1 with left primary bronchial foreign body. In addition, through bronchofibroscopy, there were 52 cases with imlfammation (100%),3 with tracheal stenosis (5.77%), 3 with left and/or right main bronchus stenosis of the external pressure, 18 with bronchomalacia(34.62%), 2 cases with foreign body (3.84%), one in trachea (1.92%), the other in left main bronchus (1.92%), 10 with bronchial mucus plug (19.23%), and 8 (15.38%) with congenital airway malformations (including 3 at tracheal bronchus, 1 at left upper lobe bronchial stenosis and 1 at bronchial Bridge). The culture of bronchoalveolar lavage lfuid were conducted for all patients. The positive rate of bronchoalveolar lavage lfuid was 9.62%(5/52 cases), including 2 cases with tip Escherichia coli, 2 with Haemophilus inlfuenzae, and 1 with Acinetobacter baumannii. Conclusions First, infection is the primary cause of refractory and persistent wheezing, which is persistent in airway resulted from multi-drug resistant bacteriua. Second, refractory and persistent wheezing is often caused by multi-factors including infection, congenital airway malformations, the endogenous and exogenous foreign body, cardiovascular malformation, etc. These factors often lead to dififcult wheezing control. The last, the diagnosis rate of the refractory and persistent wheezing can be improved by combination of ifberoptic bronchoscopy and lung spiral CT.

OBJECTIVETo investigate histone acetylation modification of topoisomerase enzyme Ⅱα (TOPOⅡα) promoter regulation factors in patients with chronic benzene poisoning, to explore the possible regulatory mechanism of TOPOⅡα involved in toxicity of chronic benzene poisoning;

METHODSThe bone marrow samples were from 25 chronic benzene poisoning cases and 25 controls. The Chromatin Immunoprecipitation (ChIP) assay was carried out to study the possible mechanism of TOPOⅡα promoter regulation factors expression changes. TOPOⅡα promoter regulation factors mRNA were detected by RT-PCR technique.

RESULTS(1) Compared with the control, the histone H4 acetylation, histone H3 acetylation level of TOPOⅡα promoter regulation factors SP1, ATF-2, SP3, NF-YA, P53, C-MYB, ICBP90, NF-M in chronic benzene poisoning patients decreased, with the significant difference (P<0.05) , except for C-JUN (P>0.05) ; (2) The mRNA expression of TOPOⅡαpromoter regulation factors SP1, NF-YA, C-MYB, C-JUN and NF-M were significantly lower than in the control with the significant difference (P<0.05) , while the expression of SP3、P53 mRNA increased (P<0.05) , ATF-2、ICBP90 mRNA wasn't changed (P>0.05) .

CONCLUSION(1) Chronic benzene poisoning TOPO Ⅱα promoter regulation factors histone modification changes accompanied with mRNA level changed. (2) Histone acetylation modification of topoisomerase enzyme Ⅱα promoter regulation factors takes important role in the benezen's Hematopoietic toxicity.

Acetylation ; Antigens, Neoplasm ; metabolism ; Benzene ; poisoning ; Case-Control Studies ; Chromatin Immunoprecipitation ; Chronic Disease ; DNA Topoisomerases, Type II ; metabolism ; DNA-Binding Proteins ; metabolism ; Histones ; metabolism ; Humans ; Poisoning ; metabolism ; Promoter Regions, Genetic ; RNA, Messenger ; metabolism