title: [Evaluation of recent thymic output function in benzene-exposed workers].
abstract: OBJECTIVE
  To analyze the content of signal joint T-cell receptor excision DNA circles signal joint T-cell receptor excision DNA circles (sjTRECs) within peripheral blood mononuclear cells (PBMCs), thereby to infer the level of naive T cells and the recent thymic output function in benzene-exposed workers.
  
  
  METHODS
  Quantitative detection of sjTRECs in DNA of peripheral blood mononuclear cells from 11 normal individuals and 62 benzene-exposed workers were performed by real-time polymerase chain reaction (PCR) and TaqMan technique.
  
  
  RESULTS
  The median value of sjTRECs copies/1,000 PBMCs was 7.81 in normal individuals whereas it was 2.56 copies/1 000 PBMCs in age-unadjusted benzene-exposed workers (P < 0.01). And its levels were obviously different between two different age groups: that in 30-year-old group (1.76 copies/1,000 PBMCs, n = 23) was less than <or= 30-years-old group (3.19 copies/1,000 PBMCs, n = 39, P < 0.05).
  
  
  CONCLUSIONS
  Benzene exposure may influence the recent thymic output function, and the sjTRECs levels may relate with the age of benzene-exposed workers.
authors.affiliation: Institute of Hematology, Medical College, Jinan University, Guangzhou 510632, China.
authors.forename: Su-fang
authors.initials: SF
authors.lastname: Han
authors.forename: Yang-qiu
authors.initials: YQ
authors.lastname: Li
authors.forename: Li-jian
authors.initials: LJ
authors.lastname: Yang
authors.forename: Shao-hua
authors.initials: SH
authors.lastname: Chen
authors.forename: Wei-wei
authors.initials: WW
authors.lastname: Liu
authors.forename: Zhen-qian
authors.initials: ZQ
authors.lastname: Huang
authors.forename: Jin-ming
authors.initials: JM
authors.lastname: Wu
authors.forename: Jia-yu
authors.initials: JY
authors.lastname: Chen
mesh_terms: D000328:Adult; D001554:Benzene / Q000506:poisoning*; D005260:Female; D015329:Gene Rearrangement, T-Lymphocyte / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D016133:Polymerase Chain Reaction; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology / Q000502:physiology*
chemical_list: D011948:Receptors, Antigen, T-Cell; D001554:Benzene