Interaction of an artificial surfactant in human pulmonary epithelial cells

Surfaxin (lucinactant), a peptide-based surfactant consisting of dipalmitoylphosphatidylcholine (DPPC) plus KL(4) (sinapultide) (a synthetic peptide modeled after human surfactant protein-B), is effective in treating respiratory distress syndrome in preterm infants. Our goal was to determine the uptake and effects of Surfaxin on human pulmonary type II cells isolated from fetal tissue and other lung cell types. Based on previous published reports, we hypothesized that this exogenous synthetic surfactant would have little effect on type II cell surfactant-related physiological features. Human type II cells and A549 and NCI-H441 adenocarcinoma cells incorporated (3)H-KL(4) and (14)C-DPPC components in Surfaxin, but with different kinetics. Fractionation of NCI-H441 and A549 cellular components indicated that the highest specific activity of (3)H-KL(4) was present in the 18,000g cellular fraction (which contains vesicles and lysosomes). The number of lamellar bodies (LBs) appears to increase in human type II cells incubated in the presence of Surfaxin when visualized by light microscopy, while LB structure (determined by electron microscopy) was not altered. Expression of endogenous surfactant protein (SP-A, SP-B, and SP-C) mRNA levels in human type II cells was not altered by the presence of Surfaxin. We conclude that while human type II cells and other lung cell types can incorporate the components of Surfaxin, the surfactant-related physiological functions of these cells are not altered.     

深圳市MSM人群的HIV感染状况及相关危险因素

目的了解深圳市男男性行为人群（MSM）艾滋病病毒（HIV）感染状况及其行为特征,分析其影响因素,为制定针对性干预策略提供建议。方法应用同伴推动抽样法招募MSM,采用电脑辅助自填问卷形式进行调查,采血检测HIV和梅毒抗体。使用RDSAT软件进行统计分析。结果调查的492名MSM,HIV阳性率为4．6％[95％可信区间（CI）：2．59％～6．7％],梅毒患病率为16．4％（95％CI：11．9％～21．0％）。平均年龄为（27．2±6．3）岁,初中以上文化占98．4％,该市户籍占8．5％,60％以上通过互联网寻找性伴,最近半年内平均男男性伴数为2．37个,32．2％的调查对象最近6个月男男性行为时未能使用安全套。艾滋病基本知识知晓率仅为61．1％,安全套使用知识知晓情况也较差,仅为55．7％。Logistic回归分析结果显示,在深圳居住小于3个月、已婚、来自HIV高流行地区、有超过一个非商业男性性伴,是MSM感染HIV的危险因素;最近6个月内获得过艾滋病相关服务,是感染HIV的保护因素。结论需进一步加强MSM中HIV监测和干预工作,有效阻断HIV传播和蔓延。     

Protease inhibitors in bronchoalveolar lavage fluid from neonates with special reference to secretory leukocyte protease inhibitor

An imbalance of proteolytic enzymes and protease inhibitors may contribute to the development of bronchopulmonary dysplasia. We studied secretory leukocyte protease inhibitor (not previously addressed), and alpha 1-antitrypsin, alpha 1-antichymotrypsin, alpha 2-macroglobulin and elastase. Albumin was used as an internal reference. Infants with pneumonia had higher concentrations of secretory leukocyte protease inhibitor (p = 0.02) and elastase (p = 0.04) in bronchoalveolar lavage fluid than those with respiratory distress syndrome; those who also developed bronchopulmonary dysplasia had intermediate values. A decreased concentration of alpha 1-antitrypsin was found in the second and third postnatal weeks (p = 0.002). Further detailed studies of the balance between proteases and protease inhibitors and of the importance of pulmonary infections in the pathogenesis of bronchopulmonary dysplasia are suggested. Secretory leukocyte protease inhibitor is important both as an elastase inhibitor of bronchial mucus and as a marker of infection in the bronchi.     

Nasal CPAP treatment of the respiratory distress syndrome

Ten newborn infants with the idiopathic respiratory distress syndrome (IRDS) or foetal aspiration (FA) were treated with a simplified nasal CPAP system (continuous positive airway pressure).The system consists of a Hudson binasal cannula and a Benveniste pediatric jet device (weight 5 g). The desired airway pressures are obtained by adjustment of the jet flow in accordance with the naso-pharyngeal flow/pressure relationship. The system was found to be effective in the treatment of 9 of the 10 children, as demonstrated by improved blood gas values, and improved respiration; the latter was also evident in infants with pronounced apnea. In one child pneumothorax, occuring after about 24 hours of successful CPAP treatment, necessitated respirator treatment.The system is quick and simple to use, and permits feeding, lung physiotherapy and routine nursing of the child during treatment.     

Variables associated with the early failure of nasal CPAP in very low birth weight infants

OBJECTIVE: To identify risk factors and neonatal outcomes associated with the early failure of "bubble" nasal continuous positive airway pressure (CPAP) in very low birth weight (VLBW) infants with respiratory distress syndrome (RDS). STUDY DESIGN: Following resuscitation and stabilization at delivery, a cohort of 261 consecutively inborn infants (birth weight < or = 1250 g) was divided into three groups based on the initial respiratory support modality and outcome at 72 hours of age: "ventilator-started" group, "CPAP-failure" group, and "CPAP-success" group. RESULTS: CPAP was successful in 76% of infants < or = 1250 g birth weight and 50% of infants < or = 750 g birth weight. In analyses adjusted for postmenstrual age (PMA) and small for gestational age (SGA), CPAP failure was associated with need for positive pressure ventilation (PPV) at delivery, alveolar-arterial oxygen tension gradient (A-a DO2) >180 mmHg on the first arterial blood gas (ABG), and severe RDS on the initial chest x-ray (adjusted odds ratio [95% CI] = 2.37 [1.02, 5.52], 2.91 [1.30, 6.55] and 6.42 [2.75, 15.0], respectively). The positive predictive value of these variables ranged from 43% to 55%. In analyses adjusted for PMA and severe RDS, rates of mortality and common premature morbidities were higher in the CPAP-failure group than in the CPAP-success group. CONCLUSION: Although several variables available near birth were strongly associated with early CPAP failure, they proved weak predictors of failure. A prospective controlled trial is needed to determine if extremely premature spontaneously breathing infants are better served by initial management with CPAP or mechanical ventilation.     

Umbilical blood gas analysis in preeclamptic versus healthy pregnancies with preterm birth

Objective: Comparing the value of umbilical cord arterial blood gas (UC-ABG) analysis in the prediction of neonatal mortality and morbidity in the preeclamptic versus healthy pregnancies with preterm birth.

Methods: Eight hundred sixteen preterm (born at?<37 gestational weeks) neonates with no other morbidities who were born by cesarean section were evaluated. Immediately after delivery, UC-ABG analysis was performed and the neonates were followed.

Results: Preeclamptic women had lower umbilical cord blood (UCB) pH (7.2 4?±?0.1 versus 7.2 7?±?0.08, p?=?0.008) and higher UCB base deficit (BD) (3.5?±?3.7 versus 2.2?±?3.4, p?=?0.005) compared with controls. In the preeclamptic group, UCB metabolic acidosis (pH?<?7.15 and B.D?>?8) was not independently associated with neonatal morbidity or mortality, while in the control group UCB metabolic acidosis was independently associated with low 10-min Apgar (OR, 4.9; 95%CI 1.37–18.03), respiratory distress syndrome (OR, 2.37; 95%CI 1.05–6.17), intraventricular hemorrhage (OR, 3.01; 95%CI 1.13–7.99), and neonatal mortality (OR, 17.33; 95%CI 4.51–66.53).

Conclusions: The preterm neonates born to preeclamptic mothers have lower UCB pH and higher BD. In these neonates, UCB acidosis is not independently associated with any adverse neonatal outcomes. In contrast, in the preterm neonates born to healthy mothers, UCB metabolic acidosis is independently associated with neonatal mortality and morbidity.     

眼镜蛇毒对油酸型呼吸窘迫综合征的保护作用

实验组小白鼠先从腹腔注射眼镜蛇毒(200μg/kg),然后从尾静脉注射油酸(0.07ml/kg),对照组先从腹腔注射生理盐水(200μl/kg),再从尾静脉注入同剂量油酸。结果表明,实验组的肺湿重、肺干重、肺系数及肺含水量等指标均比对照组显著下降。增加静脉注射的油酸剂量至0.1ml/k8,重复实验,结果相同。说明适量的眼镜蛇毒可缓解油酸型呼吸窘迫综合征(RDS)。     

视网膜色素变性遗传致病基因peripherin/RDS的突变筛选

目的 了解中国视网膜色素变性患者（RP）中peripherin/RDS基因的突变谱及突变率。方法 应用聚合酶链-异源双链-单链构象多态性（PCR-SSCP）及DNA序列分析技术对收集的15个常染色体显性遗传视网膜色谱变性家系和55例散发视网膜色素变性患者peripherin/RDS基因的第一，第二外显子进行检测。结果 15个家系及55例散发患者未检测到peripherin/RDS基因突变。结论 本研究所检测的视网膜色素变性患者与RDS基因无关，显示视网膜色素变性的遗传异质性。     

新生儿呼吸窘迫综合征的护理

目的 总结35例新生儿呼吸窘迫综合征患儿的护理体会.方法 保暖、营养支持、氧疗和替代疗法的护理,加强呼吸道管理.结果 减少合并症的发生,提高早产儿的生存率.结论 有效控制体温,正确掌握吸引、气道湿化技术,营养及热量的供给,保持足够的氧浓度是治疗成功的关键.