高氧、维甲酸对胎鼠肺角化细胞生长因子及其受体表达的影响

目的　探讨高氧、维甲酸 (RA)对胎鼠肺成纤维细胞 (LFs)和肺泡II型上皮细胞 (AECII)角化细胞生长因子 (KGF)及其受体 (KGFR)表达的影响。方法　原代培养胎鼠肺LFs及AECII ,待生长至亚汇合状态时 ,随机分为 :空气组 ,空气 +RA组 ,高氧组 ,高氧 +RA组。于培养 2、6、12、2 4、4 8(AECII)和 72h(LFs)时 ,采用半定量RT -PCR方法检测KGF和KGFR的mRNA表达。结果　与空气组比较 ,高氧 2h时 ,胎鼠LFsKGFmRNA表达即明显下降 ,6h时达极点 ,以后下降趋势逐渐减弱 ,至 4 8h后已无显著性差异 ;高氧 2、6、12和 2 4h时 ,其下降幅度分别为 3 0、5 2、2 3和 2 1倍 (P <0 0 5、0 0 1、0 0 1和 0 0 5 )。RA可上调高氧状态下胎鼠LFsKGFmRNA表达 ,与高氧组比较 ,高氧 +RA组在 2、6、12和 2 4h时KGFmRNA表达分别是高氧组的 2 4、3 4、1 7和 1 8倍 (P <0 0 5、0 0 1、0 0 1和 0 0 5 )。高氧对胎鼠AECIIKGFRmRNA表达影响较小 ,与空气组比较 ,仅在高氧 12h和 2 4h时其表达量分别是空气组的 2 3和 1 3倍 (P <0 0 5 ) ;RA对AECIIKGFRmRNA表达没有影响。结论　促进KGF的表达是RA发挥高氧肺损伤保护作用的重要机制之一     

高氧对早产大鼠角化细胞生长因子mRNA及增殖细胞核抗原表达的影响

目的　探讨 85 %高浓度氧暴露对早产新生大鼠肺组织角化细胞生长因子 (KGF)mRNA及增殖细胞核抗原 (PCNA)动态表达的影响。方法　早产SD大鼠生后 1d随机分为空气组、高氧组。高氧组持续暴露 85 %氧气中 ,空气组置于同一室内常压空气中。两组分别于 1、4、7、10、14和 2 1d时 ,提取肺组织RNA ,采用半定量逆转录聚合酶链反应 (RT PCR)测定KGFmRNA ;同时应用免疫组化检测肺组织切片中PCNA。结果　 (1)与空气组相比 ,高氧 1d时 ,KGFmRNA表达无明显差异 (P >0 0 5 ) ;4d时明显增强 ,较空气组增加 3 8倍 (P <0 0 0 1) ;其后开始下降 ,7d时较空气组增加 1 8倍 (P<0 0 5 ) ;10d时两组间无明显差异 (P >0 0 5 ) ;14d时较空气组降低 1 5倍 (P <0 0 1) ,2 1d时复又增高 ,较空气组增加 1 15倍 (P <0 0 1)。 (2 )空气组早产新生大鼠生后 14d内肺组织中均有PCNA表达 ,并且PCNA阳性细胞 90 %以上定位于气道和肺泡上皮细胞 ,2 1d时几乎检测不出其表达 ;与空气组比较 ,高氧组 1～ 4d时肺组织中PCNA表达明显减弱 ,7～ 10d时增强且部分间质细胞也有表达 ,2 1d时PCNA阳性细胞以间质细胞为主。结论　 85 %高氧暴露可促进早产新生大鼠肺组织KGFmRNA及PCNA表达     

前列腺素E1对高氧诱导新生大鼠脑损伤的保护作用

目的 探讨前列腺素E1（PGE-1）对高氧诱导新生大鼠脑损伤的保护作用,并观察糖调节蛋白78（GRP78）、CHOP蛋白表达的变化,为临床应用PGE-1治疗高氧引起的新生儿脑损伤提供理论依据。方法 将60只新生Wistar大鼠随机分成空气对照组、高氧脑损伤模型组和高氧脑损伤+PGE-1组。除空气对照组外均制备高氧脑损伤模型,从造模第1天起,高氧脑损伤+PGE-1组腹腔注射PGE-1,剂量为每日2 μg/kg,连续7 d,其他两组以生理盐水替代。检测各组大鼠脑组织含水量,苏木精-伊红染色观察脑组织病理变化,核染色结合TUNEL染色观察脑细胞凋亡情况,Western blot法检测脑组织GRP78、CHOP蛋白水平。结果 高氧脑损伤模型组脑组织含水量高于高氧脑损伤+PGE-1组及空气对照组（P < 0.05）;高氧脑损伤+PGE-1组脑组织含水量高于空气对照组（P < 0.05）。脑组织病理切片结果显示：高氧脑损伤模型组大鼠脑实质可见炎症细胞浸润增多,轻度脑血管水肿;高氧脑损伤+PGE-1组大鼠脑实质周围炎症及水肿较高氧脑损伤模型组减轻。高氧脑损伤模型组脑组织细胞凋亡指数高于高氧脑损伤+PGE-1组及空气对照组（P < 0.05）;高氧脑损伤+PGE-1组脑组织细胞凋亡指数高于空气对照组（P < 0.05）。高氧脑损伤模型组脑组织GRP78、CHOP蛋白的相对表达高于高氧脑损伤+PGE-1组和空气对照组（P < 0.05）;高氧脑损伤+PGE-1组GRP78、CHOP蛋白的相对表达高于空气对照组（P < 0.05）。结论 PGE-1对高氧诱导脑损伤新生大鼠具有保护作用,其机制可能为通过下调GRP78、CHOP蛋白表达,从而抑制细胞凋亡。     

罗格列酮对新生大鼠高氧肺损伤的保护作用

目的：探讨PPAR-γ配体罗格列酮在新生大鼠高氧肺损伤中的保护作用。方法：取新生Sprague-Dawley大鼠96只,随机分为对照组、高氧组和罗格列酮治疗组。对照组在空气中饲养,后两组暴露在85%～90%氧气中。治疗组给予罗格列酮腹腔内注射每日1次（2 mg/kg）。3组于实验第1、3、7、14 d各处死8只大鼠并取其肺组织,行苏木精-伊红染色观察其病理形态改变,同时取其肺泡灌洗液（BALF）,检测其中的丙二醛（MDA）含量及白细胞计数。结果：对照组在各时间点均未见明显病理性改变;高氧组3 d时肺泡上皮细胞肿胀,肺泡腔内可见大量炎性渗出液,14 d时肺泡减少,肺间质增厚,肺泡发育受阻;与高氧组相比,罗格列酮治疗组炎症反应表现较轻,肺泡发育障碍有所缓解。与对照组相比,高氧组3 d时辐射状肺泡计数(RAC)明显下降（P<0.05）,MDA和白细胞计数明显增高（P<0.05）,这种变化一直持续至14 d（P<0.05）;与高氧组相比,罗格列酮治疗组3、7、14 d各亚组RAC明显增高（P<0.05）,MDA和白细胞计数水平较低（P<0.05）。结论：高氧肺损伤时出现肺部的急性炎症反应和肺泡发育受阻,罗格列酮对高氧肺损伤可能具有保护作用。     

不同来源骨髓间充质干细胞对新生大鼠高氧肺损伤的影响

目的 研究大鼠及人骨髓来源的问充质干细胞(mesenchymal stem cells,MSCs)对高氧所致新生大鼠肺组织损伤的干预作用.方法 采用贴壁选择法分离、培养、扩增大鼠及人骨髓来源MSCs,以PBS按要求稀释供注射用;3日龄清洁级SD新生大鼠24只,随机分为高氧 人MSCs组(A组)、高氧 鼠MSCs(B组)、高氧对照组(C组)三组;A、B、C三组均先将大鼠置于95%氧环境下7 d后,A组每只大鼠腹腔注射5×104的人MSCs,B组每只大鼠腹腔注射5×104的鼠MSCs,C组仅注射PBS,注射后72 h(13日龄)处死全部动物,肺组织病理学检测辐射状肺泡计数(radical alveolar eounts,RAC);ELASA法检测肺组织匀浆TNFα、IL-1β含量.结果 与对照组相比,二个注射MSCs组(A、B组)RAC值显著增高,TNFα、IL-1β显著降低.A、B组间差异也有统计学意义.结论 给新生大鼠腹腔注射人MSCs及鼠MSCs均可对高氧损伤的肺损伤起保护作用,其机制可能与MSCs影响损伤部位细胞因子的表达有关.     

Longitudinal assessment of growth and bone mineral accretion in prematurely born infants treated for chronic lung disease with dexamethasone

The objective of this study in premature infants was to assess the relationship between dexamethasone, growth and bone mineral accretion. Nine appropriate size for gestational age premature infants treated for chronic lung disease with tapering doses of dexamethasone (0.5–0.1 mg/kg/day over 37±7 days) were individually matched to a comparison infant by sex, gestational age, birth-weight, and type of feed. Infant growth and bone mineral accretion were measured at equivalent gestational ages from recruitment until 6 months corrected age. During hospitalization, mean rate of weight, length and head circumference growth and bone mineral accretion in the distal radius were significantly lower in the dexamethasone-treated infants in spite of similar nutrient intakes. Dexamethasone infants had significantly lower plasma phosphorus, and urinary calcium, pyridinoline and N-telopeptide excretion. Dexamethasone affected absolute length, but not weight, throughout the study. No significant differences were observed in body composition or absolute radial and whole body bone mineral content. The results indicate that dexamethasone therapy compromises growth and bone mineral accretion in small premature infants. `Catch-up' linear growth was not evident at 6 months of age and reflects the importance of early nutrition interventions.     

神经生长因子减轻新生大鼠缺氧缺血性脑损伤

目的 观察神经生长因子对新生大鼠缺氧缺血性脑损伤的保护作用。方法 对５４只７日龄Ｗｉｓｔａｒ大鼠随机分为ＮＧＦ治疗组和对照组,缺氧缺血后即刻腹腔内注射ＮＧＦ或生理盐水。４４小时后测定各组脑含水量,２８天后测量各组脑重量并观察脑大体改变和组织学改变。     

卡托普利对高氧致新生大鼠慢性肺疾病的保护作用及机制探讨

目的：观察高氧致慢性肺疾病（CLD）新生大鼠肺组织ACE,AngⅡ和ColⅠ蛋白及mRNA含量的动态变化,以探讨卡托普利的保护作用及机制。方法：足月新生Wistar大鼠240只,随机分为高氧组、空气对照组、卡托普利治疗组和盐水对照组,每组各60只。将高氧组、盐水对照组和卡托普利治疗组的足月新生Wistar 大鼠（连同母鼠）生后即置于氧舱内持续吸入高浓度氧（FiO2=0.9）21 d造成高氧肺损伤模型,空气对照组吸入空气。卡托普利治疗组于生后7 d每天经胃管灌服卡托普利每日30 mg/kg, 盐水对照组每天经胃管灌服等量生理盐水。每组分别于实验开始后第1,3,7,14,21天随机选取6只麻醉后处死。肺组织采用ELISA法测定ColⅠ蛋白含量,用日产7170全自动生化分析仪测定ACE活性,用放免法测定AngⅡ的含量。用RT-PCR法检测肺组织ACE,AngⅡ,ColⅠmRNA表达的动态变化并同时观察肺组织形态学变化。结果：与空气对照组比较,高氧组、盐水对照组肺组织ACE,AngⅡ,ColⅠ蛋白含量及mRNA表达在实验后第14天明显升高,第21天达高峰(P<0.05或P<0.01),卡托普利治疗组上述指标与高氧组、盐水对照组比较明显降低(P<0.05或P<0.01),但仍高于空气对照组（P<0.05）。 肺组织形态学改变：高氧组、盐水对照组第14天肺组织间质细胞增多,出现纤维化改变。第21天正常肺泡结构消失,肺组织出现严重的纤维化。卡托普利治疗组肺组织纤维化病变明显减轻。结论：卡托普利干预抑制了高氧致CLD新生大鼠肺组织ACE,AngⅡ,ColⅠ蛋白含量及mRNA表达,减轻了肺纤维化病变,这可能是卡托普利对高氧肺损伤具有保护作用的机制之一。［中国当代儿科杂志,2007,9（2）：169-173］     

川芎嗪对慢性高氧肺损伤新生大鼠内源性一氧化氮合酶表达水平的影响

目的观察川芎嗪干预对新生大鼠高氧肺损伤的影响及可能作用机制。方法80只足月新生12h内的清洁级SD大鼠,随机分为空气组（A组）、空气＋川芎嗪组（B组）、高氧（60％）组（C组）、高氧＋川芎嗪组（D组）。B、D两组每日腹腔注射川芎嗪30mg／kg,一日一次,A、C两组每日腹腔注射等量生理盐水,实验第14天每组随机选取8只,测量体重后取肺组织,测量肺质量,HE染色观察肺组织病理改变并计算其放射状肺泡计数（RAC）、RT—PCR方法检测内皮型一氧化氮合酶（eNOS）mRNA表达水平;免疫组织化学染色法检测eNOS蛋白表达水平。结果C组显示明显的肺泡发育受阻,体重（g）、肺质量（g）、RAC值（个）较A、B组均明显减少[体重：（17．4±3．2）比（29．5±1．7）、（29．3±1．6）,肺质量：（0．26±0．04）比（0．41±0．03）、（0．40±0．03）,RAC值：（4．8±0．7）比（9．0±0．8）、（8．8±0．9）,P〈0．05],D组病理改变减轻,体重、肺质量、RAC值高于C组（P〈0．05）,与A组相近（P〉0．05）。与A组（3．54±0．37）相比,C组肺组织eNOS表达水平（2．76±0．23）明显降低,D组（3．80±0．36）表达较C组增加,差异有统计学意义（P〈0．05）,与A组相近（P〉0．05）。结论高氧可导致新生大鼠出现肺损伤,病理改变类似于早产儿新型支气管肺发育不良,川芎嗪干预对其有一定保护作用,其机制可能与川芎嗪促进eNOS的表达并捅过内源性NO生成增多而降低肺微血管压力有美．     

MK-801对新生大鼠高氧性肺损伤的保护作用

目的观察谷氨酸(Glu)的NMDA受体拮抗剂MK-801对新生大鼠高氧性肺损伤的影响,探讨Glu在高氧性肺损伤中的可能作用。方法出生12h内的SD新生大鼠随机分为:空气对照组、空气 MK-801组、高氧对照组及高氧 MK-801组。观察持续高氧暴露7d后各组肺湿/干重比(W/D)、支气管肺泡灌洗液(BALF)中白细胞及中性粒细胞数、肺组织及BALF中一氧化氮(NO)含量的变化。结果MK-801可有效地抑制高氧所致新生大鼠肺W/D、BALF中白细胞和中性粒细胞、肺组织和BALF中NO含量的增高。结论MK-801可有效地减轻新生大鼠高氧性肺损伤,提示内源性Glu通过NMDA受体介导,促进NO的产生而加重肺损伤。     

Executive function skills are associated with reading and parent-rated child function in children born prematurely

Background

Preterm children are at risk for executive function (EF) problems, which have been linked to behavior and learning problems in full term children. In this study, we examine the relationship between EF and functional outcomes in preterm children.

Aim

To evaluate (1) EF skills of 9- to 16-year-old children born across the spectrum of gestational age (GA), (2) relationship of degree of prematurity to EF skills, and (3) contributions of EF skills to two functional outcomes — reading scores and parent-rated child function.

Method

Preterm children < 36 weeks gestation (n = 72) were compared to full term children (n = 42) of similar age, gender and SES, on measures of EF, reading, and parent-ratings of child function. Multiple regression models evaluated contributions to EF skills and functional outcomes.

Results

Compared to full term controls, preterm children had poorer EF performance on a complex planning and organization task and did not increase planning time as task difficulty increased. Their spatial memory capacity was not different. GA contributed to EF skills, but was mediated by IQ. EF contributed to the variance in reading skills but did not add to the variance in reading when IQ was considered. EF skills significantly contributed to the variance in parent-rated child function, but IQ did not.

Conclusion

EF skills contribute to measures of functional outcome in this high-risk population. The use of EF skills as an early marker for learning and functional problems and as a target for intervention in children born preterm warrants future study.     

结缔组织生长因子在高氧致早产鼠慢性肺疾病中的表达及其作用

目的：肺纤维化是高氧致慢性肺疾病(chroniclungdiseases,CLD)的最终结局,结缔组织生长因子(connectivetissuegrowthfactor,CTGF)是近年来发现的与纤维化形成密切相关的因子,但其在CLD肺纤维化中的作用目前尚未见报道。该实验旨在研究CTGF在高氧致CLD中的动态表达规律,并探讨其在CLD中的作用。方法：将50例早产鼠随机分为实验组(高氧组)和对照组(空气组),分别于建立模型后1,3,7,14,21d应用免疫组化技术动态检测肺组织中CTGF的表达部位和强度,对肺组织纤维化程度进行病理组织学评分。结果：对照组小鼠CTGF仅在血管内皮细胞、支气管、细支气管上皮细胞有微弱表达;实验组于建立模型后1,3,7d表达部位与对照组相似,表达强度与对照组无差异(P>0.05),14d表达增强(P<0.01),在部分肺上皮细胞、肺泡间隔、成纤维细胞中出现表达,21d表达明显增强(P<0.01)。高氧组14d和21dCTGF表达水平与肺组织纤维化程度呈明显正相关(分别为r=0.903,r=0.926,均P<0.01)。结论：随着高氧暴露时间的延长和纤维化的发展,CTGF表达增强,其与高氧所致CLD肺纤维化的发生密切相关。     

Diminished lung function, RSV infection, and respiratory morbidity in prematurely born infants

Background

Diminished lung function appears to be a risk factor for respiratory syncytial virus (RSV) infection/bronchiolitis in term born infants.

Aims

To determine if diminished lung function prior to neonatal unit discharge was associated with subsequent symptomatic RSV lower respiratory tract infection (LRTI) and respiratory morbidity in prematurely born infants.

Methods

Of 39 infants in a tertiary neonatal intensive care unit (median gestational age 28 weeks, range 23–31), 20 had bronchopulmonary dysplasia. Lung function (compliance and resistance of the respiratory system (C_rs and R_rs) and functional residual capacity (FRC)) was measured on the neonatal unit at 36 weeks postmenstrual age (PMA). Following neonatal unit discharge, nasopharyngeal aspirates were obtained on every occasion, at home or in hospital, an infant had an LRTI. RSV was identified by immunofluorescence and/or culture.

Results

The 15 infants who suffered a symptomatic RSV LRTI had a higher mean R_rs and suffered more wheeze at follow up than the rest of the cohort. Regression analysis showed that a high R_rs was significantly associated with a symptomatic RSV LRTI; significant factors for cough were a high R_rs and a symptomatic RSV LRTI, and for wheeze were a high R_rs.

Conclusion

Prematurely born infants, who had a symptomatic RSV LRTI and/or respiratory morbidity at follow up, had worse lung function prior to neonatal unit discharge.     

Sleeping position, oxygen saturation and lung volume in convalescent, prematurely born infants

OBJECTIVE: To determine whether the effects of sleeping position on lung volume and oxygenation are influenced by postmenstrual age (PMA) and oxygen dependency in convalescent prematurely born infants. DESIGN: Prospective study. SETTING: Tertiary neonatal unit. PATIENTS: 41 infants (21 oxygen dependent), median gestational age 28 weeks (range 24-31 weeks) and birth weight 1120 g (range 556-1780 g). INTERVENTION: Infants were studied both supine and prone at two-weekly intervals from 32 weeks' PMA until discharge. Each posture was maintained for 1 h. MAIN OUTCOME MEASURES: Pulse oximeter oxygen saturation (Spo(2)) was monitored continuously, and at the end of each hourly period functional residual capacity (FRC) was measured. RESULTS: Overall, lung volumes were higher in the prone position throughout the study period; there was no significant effect of PMA on lung volumes. Overall, Spo(2) was higher in the prone position (p = 0.02), and the effect was significant in the oxygen-dependent infants (p = 0.03) (mean difference in Spo(2) between prone and supine was 1.02%, 95% CI 0.11% to 1.92%), but not in the non-oxygen-dependent infants. There was no significant influence of PMA on Spo(2). CONCLUSION: In the present study, prone sleeping did not improve oxygenation in prematurely born infants, 32 weeks' PMA or older and with no ongoing respiratory problems. However, the infants were monitored in each position for an hour, thus it is recommended that oxygen saturation should continue to be monitored after 32 weeks' PMA to be certain that longer periods of supine sleeping are not associated with loss of lung volume and hypoxaemia.     

Early predictors of hypertension in prematurely born adolescents

Objective: To assess the blood pressure of former preterm and term matched adolescent controls and to identify risk factors associated with blood pressure at 16 years. Design: Observational cohort study. Secondary analysis of a randomized clinical trial. Setting: Three academic centres participating in the Multicenter Indomethacin IVH Prevention Trial. Participants: A total of 296 children born in 1989–1992 with birth weights 600 to <1250 g who participated in the Multicenter Indomethacin IVH Prevention Trial and 95 term controls were evaluated at 16 years. Main outcome measures: Blood pressure and predictors of blood pressure. Results: The adjusted mean difference in blood pressure for preterm adolescents was 5.1 mm Hg; p = 0.002 for systolic and 2.1 mm Hg; p = 0.027 for diastolic blood pressure. Among preterms, the primary predictors of increased systolic blood pressure were weight gain velocity between birth and 36 months (b = 8.54, p < 0.001), pre‐eclampsia (b = 5.67, p = 0.020), non‐white race (b = 3.77, p = 0.04) and male gender (b = 5.09). Predictors of diastolic blood pressure were weight gain velocity between birth and 36 months (b = 4.69, p = 0.001), brain injury (b = 6.51, p = 0.002) and male gender (b = ?2.4, p = 0.02). Conclusions: Early programming secondary to increased early weight gain velocity, intrauterine stress and neonatal brain injury may all contribute to risk of increased blood pressure among former preterm adolescents.