20例汉族新生儿呼吸窘迫综合征的SP-B遗传缺陷的研究

Objective To investigate the relationship between expression of surfactant protein B (SP-B) gene product and neonatal respiratory distress syndrome (NRDS) in Han ethnic group.Methods Unrelated 20 cases with NRDS of Han ethnic group were selected as NRDS group while unrelated 20 cases of Han ethnic group with other diseases were selected as a control. The cases in the control group had congenital heart disease or bronchopulmonary dysplasia or persistent pulmonary artery hypertension. Blood sample was taken from each case. Lung tissues were taken from the patients in half an hour after their death in the two groups. Expression of SP-B in the lung tissues was determined with immunohistochemical technique. Genetic deficiency variant of SP-B intron Ⅳ was screened with polymerase chain reaction (PCR).Results Two cases at gestational age of 26 weeks, one at 34 weeks and two at 42 weeks in the NRDS groups had lower expression level of SP-B in the lung tissues than those at the same age in the the control group. Expression of SP-B in the lung tissues of the control group increased with gestational age, but no such phenomenon was found in NRDS group. Further two cases at gestational age 42 weeks of NRDS group had genetic deficiency variant of SP-B intron Ⅳ with gene analysis of five cases who had lower expression of SP-B. Clinical data suggest that patients at 42 weeks of gestational age had severe illness.Conclusion Decrease of SP-B expression may be involved in occurrence of NRDS, genetic deficiency variant of SP-B intron Ⅳ exists in NRDS cases of Han ethnic group of China.

Objective: To investigate the changes of the markers of pulmonary vascular endothelial cells (PVECs) after acute lung injury (ALI) induced by bone marrow extract (BME)injection in rabbits.Methods: Thirty-one rabbits were randomized into control (CG, n ＝ 10) and experimental groups (EG, n ＝21). The rabbits in EG were injected with homogeneous bone marrow extract (0.35 ml/kg, 2 ml/h) at a slow and continuous rate through the jugular vein to establish the model of ALI. At 6 h after the injection, the number of circulating endothelial cells (CECs) in the blood, contents of granule membrane protein-140 (GMP-140), angiotensin converting enzyme (ACE) and endothelin-1 (ET-1) in the plasma and the content of GMP-140 in the pulmonary tissue were determined at various time intervals. Then the animals were killed and routine pathological examination and electron microscopy were performed to observe the changes in the pulmonary tissue.Results: The levels of plasma GMP-140, ACE, ET-1and CECs were significantly increased in the early stage (0.5 h) and remained higher for 6 h. The marked increase of plasma GMP-140 (3.25 times) in the early stage was negatively correlated to PaO2, but positively to other parameters. IHC-staining showed that the GMP-140 on the surface of PVECs became weak.Conclusions: BME injection at slow and continuous rate can establish an acceptable model of ALI. Determination of plasma GMP-140 might be an important measure for the early surveillance and the evaluation of prognosis of ALI in clinical management of serious traffic accidents.

Background: Surfactant replacement therapy has been used for few decades for the treatment of respiratory distress syndrome (RDS) and has significantly improved morbidity and mortality in premature infants. Non-invasive respiratory support has recently emerged as a strategy in the early management of RDS. In this review, we discuss the different strategies of early management of RDS.
Data sources: A literature search of PubMed database was conducted to review the subject. The quality of evidence of key clinical studies was graded according to a modified grading system of the international GRADE group.
Results: Continuous positive airway pressure (CPAP) with selective surfactant is a safe alternative to routine intubation, surfactant and mechanical ventilation in preterm infants with spontaneous breathing, and such an approach has been associated with decreased risk of death and bronchopulmonary dysplasia. There is a risk of pneumothorax when using a high pressure of CPAP (≥8 cm of H2O), a high partial pressure of carbon dioxide (PCO2 >75 mm of Hg), and a high fraction of inspired oxygen (FiO2 >0.6) as a threshold for intubation while on CPAP.
Conclusion: Not all preterm infants need surfactant treatment, and non-invasive respiratory support is a safe and effective approach.