[Effect of gamma-aminobutyric acid treatment on plasma substance P and calcitonin gene-related peptide levels in children with asthma].

OBJECTIVE: To study the changes in plasma substance P (SP) and calcitonin gene-related peptide (CGRP) levels in children with acute asthma before and after gamma-aminobutyric acid (GABA) treatment. METHODS: Seventy-five children with asthma were randomly assigned to GABA treatment (n=36) and control groups (n=39). Both groups were given conventional treatment for asthma. Besides the conventional treatment, the treatment group was administered with oral GABA (25-30 mg/kg•d). Plasma content of SP and CGRP was measured using ELISA before treatment and after remission. RESULTS: There were no significant differences in plasma content of SP and CGRP between the GABA treatment and control groups (P＞0.05) before treatment. Plasma content of SP and CGRP in the GABA treatment group was significantly lower than the control group (SP: 57±15 pg/mL vs 127±12 pg/mL; CGRP: 23±10 pg/mL vs 42±8 pg/mL) after remission (P<0.01). Plasma content of SP and CGRP after remission was significantly lower than before treatment (P<0.01) in both groups. There was a significantly positive correlation between plasma SP and CGRP content in asthmatic children (r=0.792, P<0.01). CONCLUSIONS: GABA can significantly decrease plasma levels of SP and CGRP in children suffering from acute asthma.

[Changes in plasma levels of thrombomodulin and D-dimer in children with different types of Mycoplasma pneumoniae pneumonia].

OBJECTIVE: To investigate the changes in plasma levels of thrombomodulin (TM) and D-dimer (DD) in children with different types of Mycoplasma pneumoniae pneumonia (MPP), and their role in the pathogenesis of MPP in children. METHODS: Fifty-two children with MMP were divided into lobar pneumonia (n=30) and interstitial pneumonia groups (n=22) and another 30 healthy children were selected as the control group. Plasma levels of TM and D-D were measured using enzyme-linked immunosorbent assay and latex-enhanced immunoturbidimetric assay, respectively. RESULTS: The lobar pneumonia, interstitial pneumonia and control groups had median plasma TM levels of 23.83, 15.56 and 8.78 µg/L respectively, with significant differences between the three groups (P<0.01). The lobar pneumonia and interstitial pneumonia groups had significantly higher plasma TM levels than the control group (P<0.01), and the lobar pneumonia group had a significantly higher plasma TM level than the interstitial pneumonia group (P<0.05). Median plasma D-D levels in the lobar pneumonia and interstitial pneumonia groups were significantly higher than the reference value (P<0.01). The lobar pneumonia group had a significantly higher plasma D-D level than the interstitial pneumonia group (0.35 µg/mL vs 0.13 µg/mL; P<0.01), and the percentage of patients with elevated plasma D-D levels was significantly higher in the lobar pneumonia group than in the interstitial pneumonia group (87% vs 59%; P<0.05). CONCLUSIONS: Children with MPP, especially those with lobar pneumonia, have increased plasma levels of TM and D-D. This suggests that damage to vascular endothelial cells and blood hypercoagulability may be involved in the pathogenesis of MPP.