[Coordinated regulation of PI3K and Notch signal pathways in the activation and proliferation of CD4(+)T lymphocytes in asthma mice].

OBJECTIVE: To explore whether the signal pathways of phosphoinositide 3-kinase (PI3K) and Notch can realize coordinated regulation on the activation and proliferation of CD4(+)T lymphocytes. METHODS: Male BALB/c mice were randomly divided into control and asthma groups. Then the murine model of asthma was established by the method of ovalbumin (OVA) challenge. The CD4(+)T lymphocytes were isolated by magnetic activated cell sorter (MACS) and then activated with phytohaemagglutinin (PHA) (10 µg/ml) and IL-2 (1000 U/ml) for 6 h. Those cells were then divided into Group A: without any treatment; Group B: treatment with PI3K inhibitor (LY294002); Group C: treatment with Notch inhibitor (gamma-secretase inhibitor, DAPT); Group D: treatment with PI3K inhibitor and Notch inhibitor. The protein and transcription levels of Cyclin A, Cyclin D1 and P27(kip1) of CD4(+)T lymphocytes were assessed by flow cytometry and reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: The results of flow cytometry showed that the purity of MACS-isolated CD4(+)T lymphocytes was 90.0% ± 5.2% and the survival rate 94.8% ± 3.2%. The protein (28.0% ± 3.5%, 14.9% ± 3.4%) and mRNA levels (0.55 ± 0.16, 1.38 ± 0.42) of Cyclin A and Cyclin D1 in CD4(+)T lymphocytes of asthma group were significantly higher than those of the control group (13.4% ± 3.5%, 7.7% ± 1.8% and 0.32 ± 0.10, 0.92 ± 0.37) (P = 0.002, 0.036 and P = 0.007, 0.042). The protein and mRNA levels (23.3% ± 3.9% and 0.16 ± 0.03) of P27(kip1) of asthma group were significantly lower than those of control group (37.5% ± 5.8% and 0.32 ± 0.03, P = 0.006 and P = 0.000). The protein and mRNA levels of Cyclin D1 in groups A, B, C and D-treated CD4(+)T lymphocytes were 12.2% ± 3.7%, 7.3% ± 3.0%, 8.1% ± 2.3%, 4.2% ± 1.7% and 1.71 ± 0.44, 1.07 ± 0.31, 1.21 ± 0.32 and 0.62 ± 0.20 respectively; groups B, C and D decreased markedly compared with group A (all P < 0.01) while group D decreased significantly compared with groups B and C (all P < 0.05). The protein levels of P27(kip1) in groups A, B, C and D were 22.9% ± 3.0%, 31.6% ± 5.3%, 28.4% ± 5.6% and 44.6% ± 2.8% respectively; group B was significantly higher than that of group A (P = 0.016) while group D was significantly higher than those of groups A, B and C (P = 0.003, 0.004, 0.000). Meanwhile P27(kip1) mRNA levels in each group were 0.16 ± 0.07, 0.36 ± 0.09, 0.63 ± 0.08 and 0.99 ± 0.21 respectively; groups B, C and D were much higher than that of group A (P = 0.016, 0.000, 0.000) while group D was significantly higher than those of groups B and C (P = 0.000, 0.023). The protein and mRNA levels of CylinA showed no statistical significance among different experimental groups (all P > 0.05). CONCLUSION: The signal pathways of PI3K and Notch may coordinately up-regulate the expression of positive regulatory factor cylinD1 and down-regulation the expression of negative regulatory factor P27(kip1) of CD4(+)T lymphocytes.

[Diagnosis and prognosis of spontaneous pneumomediastinum in eighteen children].

OBJECTIVE: To analyze the diagnosis, treatment and prognosis of spontaneous pneumomediastinum (SPM) in children. METHOD: A retrospective analysis of the clinical data of 18 children diagnosed with SPM in Yuying Children's Hospital Affiliated to Wenzhou Medical University from December 2007 to February 2013 was performed. Information of the sequelae and recurrence of SPM was obtained by telephone follow-up. SPM was diagnosed according to Versteegh's standard. SPM cases due to mechanical ventilation, trauma, inhaled foreign body or as a result of the underlying disease were not included. Also cases of secondary pneumothorax pneumomediastinum and neonatal mediastinal emphysema were excluded. RESULT: Fifteen of 18 cases were boys and 3 were girls, the range of age was from 9 to 17 years. Predisposing factors included sport activities, severe cough or without a known cause. Clinical manifestations included chest pain, chest tightness, dyspnea, neck pain, back pain, foreign body sensation or pain on swallowing, throat pain of swelling. Chest CT of 18 cases showed pneumomediastinum, 8 cases displayed varied degrees of air in neck, chest; 18 cases of SPM responded well to bed rest, oxygen, antitussive and anti-infection treatment. Fifteen cases received chest CT or X-ray inspection after therapy, showing that the pneumomediastinum disappeared or significantly absorbed, 3 cases improved in clinical symptom. Among 18 patients, telephone follow-up of 14 were successful and 4 cases were lost. An average follow-up time was (24 ± 17) months. None of the cases had any serious consequences, and recurrence happened in one case. CONCLUSION: Children's spontaneous pneumomediastinum is a benign disease. When a child has chest pain or chest tightness, SPM should be considered after excluding the common diseases. SPM can be diagnosed in association with clinical feature and chest CT examination. Patients respond well to conservative therapy and most of them had no severe sequelae.