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Objective To establish a real‐time fluorescent polymerase chain reaction and detect 16S rRNA gene of Legionella strains isolated from sputum specimens of patients with pulmonary infection by using this method .Methods 16s rRNA gene of Le‐gionella was used to design primers and probes .The reaction system and reaction conditions were optimized and the specificity ,sen‐sitivity and repeatability of this method were verified by detecting Legionella pneumophila ,non‐Legionella pneumophila and other bacteria .A total of 557 sputum specimens of patients with pulmonary infection were detected ,and PCR‐digestion identification method was carried out as control .Otherwise ,sequences of 16S rRNA were verified in patients with positive detection results .Re‐sults The results showed that all reference strains of Legionella were positive ,while all of other bacteria were negative ,and the sensitivity was 102 CFU/mL .Among sputum specimens collected from 577 cases of patients with pulmonary infection ,the positive rate of Legionella detected by using real‐time fluorescent PCR and PCR‐digestion identification method was 23 .1% and 19 .9% re‐spectively ,while the positive rate was 17 .2% by verifying the sequences of 16s rRNA .There were no statistically significant differ‐ences of positive rate among the three methods(P>0 .05) .Conclusion The real‐time fluorescent PCR is fast and convenient in de‐tection of Legionella strains isolated from sputum specimens of patients ,which could be an assisted method for clinically diagnosing Legionella infection .
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BACKGROUND: Although we have gained much information about leadinduced organ damage, the effect of blood lead level on T cell subgroup is yet to be determined.OBJECTIVE: To assess the effect of blood lead level on T cell subgroup of children, and the association of T cell subgroup with threshold limit value of blood lead level.DESIGN: Comparative observation.SETTING: The Institute of Molecular Microorganism, Maternity and Child Care Hospital, Shanxi Provincial Children Hospital.PARTICIPANTS: Sixty children, (32 boys and 28 girls), aged 3-6 years with a mean of (4.5±1.5) years old, were selected from the suburbs of Taiyuan city between May 2003 and October 2003. Informed consents were obtained from all their guardians. The enrolled children according to their blood lead levels were assigned into three groups, 13 in Group Ⅰ with blood lead level ≥ 0.48 μmol/L, 20 in Group 2 with lead level ≥ 0.24 μmol/L but ＜ 0.48 μmoL/L and 27 in Group 3 with lead level ＜ 0.24 μmol/L.METHODS: Blood lead level and expression of T cell subgroup were measured with graphite furnace atomic absorption spectroscopy and immunofluorescence methods respectively. Student t test was used in data analysis, and linear correlation analysis was used to assess the correlation between blood lead level and expression of T cell subgroup.level and expression of T cell subgroup.pression of CD3 and ratio of CD4 to CD8 were lower in Group 1 (lead level ≥0.48 μmol/L) than Group 3 (lead level ＜ 0.24 μmol/L) (t=3.27,blood lead level showed had significant inverse correlation with CD3 expression and the ratio of CD4 to CD8(r=-0.689,-0.674,P ＜ 0.01).CONCLUSION: A blood lead level ≥ 0.48 μmol/L, is shown to significantly decrease the expression of CD3 and ratio of CD4 to CD8 in peripheral blood, which may impair the children's immunological function.
RESUMO
BACKGROUND: Although we have gained much information about leadinduced organ damage, the effect of blood lead level on T cell subgroup is yet to be determined.OBJECTIVE: To assess the effect of blood lead level on T cell subgroup of children, and the association of T cell subgroup with threshold limit value of blood lead level.DESIGN: Comparative observation.SETTING: The Institute of Molecular Microorganism, Maternity and Child Care Hospital, Shanxi Provincial Children Hospital.PARTICIPANTS: Sixty children, (32 boys and 28 girls), aged 3-6 years with a mean of (4.5±1.5) years old, were selected from the suburbs of Taiyuan city between May 2003 and October 2003. Informed consents were obtained from all their guardians. The enrolled children according to their blood lead levels were assigned into three groups, 13 in Group Ⅰ with blood lead level ≥ 0.48 μmol/L, 20 in Group 2 with lead level ≥ 0.24 μmol/L but ＜ 0.48 μmoL/L and 27 in Group 3 with lead level ＜ 0.24 μmol/L.METHODS: Blood lead level and expression of T cell subgroup were measured with graphite furnace atomic absorption spectroscopy and immunofluorescence methods respectively. Student t test was used in data analysis, and linear correlation analysis was used to assess the correlation between blood lead level and expression of T cell subgroup.level and expression of T cell subgroup.pression of CD3 and ratio of CD4 to CD8 were lower in Group 1 (lead level ≥0.48 μmol/L) than Group 3 (lead level ＜ 0.24 μmol/L) (t=3.27,blood lead level showed had significant inverse correlation with CD3 expression and the ratio of CD4 to CD8(r=-0.689,-0.674,P ＜ 0.01).CONCLUSION: A blood lead level ≥ 0.48 μmol/L, is shown to significantly decrease the expression of CD3 and ratio of CD4 to CD8 in peripheral blood, which may impair the children's immunological function.
