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Abstract Objectives: Upper respiratory tract infections in children generally have significant morbidity and mortality. There is little data available about functional immaturity of the immune system and the child's susceptibility to infections at the beginning of their lives, thus, justifying a more specific immunological analysis. Method: Analysis of hemograms and innate and adaptive immune responses in 95 children between age 1 to 6 years with episodes of recurrent respiratory infections (test group n = 39) and without these episodes (control group n = 56) was carried out. The production of reactive oxygen intermediates by peripheral blood cells stimulated by phorbol myristate acetate was analyzed. Additionally, the number of B lymphocytes, auxiliary T lymphocytes, and cytotoxic cells was determined using flow cytometry. Results: Results from both groups did not show statistically significant differences in red blood cells, total leukocytes count, and the differential neutrophils, eosinophils, basophils, lymphocytes, and monocytes count. The analysis of the number of B lymphocytes, auxiliary T lymphocytes (LTCD4), and cytotoxic cells (LTCD8) also did not show any difference between both groups. However, the production of radical oxygen intermediates was significantly reduced in the test group as compared to the control group (p < 0.05). Conclusions: There was no difference in the analysis of hemograms, leukograms, or the number of lymphocytes, LTCD4, LTCD8, or LTCD19. The reduced production of oxygen intermediates in the affected group suggests that these children's microbicide capacity is compromised, which may be related to their recurrent respiratory infections.
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Objective To explore the regulating effects of Egr-1 promoter activated by ionizing radiation (IR) and doxorubicin (ADM) on the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) genes. Methods The human GM-CSF cDNA and enhanced green fluorescent protein (EGFP) cDNA were linked together with IRES(internal ribosome entry site) and then inserted into the expression vector pCIneo under control of the Egr-1 promoter(Egr-EG). The vector was transferred into human bone marrow stromal cell line HFCL by liposome transfection. And the cells were exposure to ADM and IR. The activity of EGFP in HFCL/EG cells were detected by FACS. The effect of N-acetylcysteine on the expression of EGFP following exposure to ADM and IR was examined. The amounts of GM-CSF in HFCL/EG after chemotherapy or radiation were measured with ELISA. The effects of GM-CSF in HFCL/EG cultural supernatants on expansion of CFU-GM derived from cord blood were also studied. RT-PCR analysis for the expression of GM-CSF mRNA in HFCL/EG after exposure to ADM or IR. Results The percentage of EGFP+ HFCL/EG cells exposed to ADM and IR was increased compared with non-treatment group (1.2 % and 15.2 % vs 18.2 %, t = 5.11, P < 0.01). The levels of secreted GM-CSF in HFCL/EG cells exposed to ADM and IR was increased (P < 0.01), but no difference between ADM group and IR group (P 0.05). The expression of EGFP by HFCL/EG treated with ADM and IR was significantly decreased by N-acetylcysteine. The effects of GM-CSF in HFCL/EG cultural supernatants on expansion of CFU-GM in ADM group and IR group were significantly higher than that in HFCL group and non-treatment group. However, The CFU-GM count of IR group was higher than that of ADM group. The expression of GM-CSF mRNA in HFCL/EG cells exposed to ADM and IR was significantly increased(t = 4.37, P < 0.01). Conclusions GM-CSF gene expression regulated by Egr-1 promoter induced by ADM and IR could help the recovery from hematopoietic injury.
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Objective: The aim of this study is to evaluate the impact of glucose-6- phosphate dehydrogenase deficiency in Chinese on the intracellular glucose-6-phosphate dehydrogenase activity and reactive oxygen intermediates production of peripheral neutrophil. Methods: Glucose-6-phosphate dehydrogenase, its mRNA expression and reactive oxygen intermediates production(NBT test) in silent or stimulated neutrophil from health controls and patients with glucose-6-phosphate dehydrogenase deficiency were analysized. Results: Compared with health controls, the activities of glucose-6-phosphate dehydrogenase of peripheral neutrophil from patients with glucose-6 -phosphate dehydrogenase deficiency was decreased, and its mRNA expression increased. Reactive oxygen intermediate production increased(no statistical signification) in silence but decreased following stimulation by LPS in neutrophil from normal individuals than that from patients. Conclusion: Decreased activity of G-6-PD and production of reactive oxygen intermediates following stimulation in neutrophil could be caused by G-6-PD deficiency in Chinese.
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Even though the brain has been considered to be an immunologically privileged organ, recent reports showed that certain cells of the brain may be involved in immunological process in the brain. For example, some cells of the brain can present antigen to T-lymphocytes, to express class II major histocompativility antigen, and secrete interleukin-1 and -3 molecules. In addition, they are capable to phagocytose particles and possess receptors for the Fc portion on IgG. In this study, the authors tried to isolate the microglial cells from new born mice and characterize them. The isolated cells could produce such reactive oxygen intermediates(ROIs) an superoxide and hydrogen peroxide that were measured by luminometer after amplification by lucigenin and luminol respectively and could secrete reactive nitrogen intermediates(RNIs), when the cells were incubated with r-IFN plus LPS. The cells could also ingest fluorescent particles and raise intracellular calcium after stimulation with agonists when measured by flow cytometer. Our data showed that the microglial cells of the brain may belong to a member of mononuclear phagocytic system(MPS) of the body that are responsible for the host defence against invading microorganisms.