除草醚诱导的小鼠先天性膈疝肺发育不良模型的建立

目的 建立小鼠先天性膈疝(CDH)模型.方法 实验组10只妊娠第8天的BABL/C小鼠通过灌胃给于除草醚25 mg/只,正常对照组给予橄榄油,于妊娠第20天剖宫产取出子鼠,解剖显微镜下观察子鼠有无膈疝形成,测定子鼠体重及双肺重量,HE染色观测肺组织发育情况,逆转录-聚合酶链反应(RT-PCR)检测肺组织SP-B、SP-C和VEGF表达水平.结果 实验组69只子鼠中有膈疝形成者39只,成功率为56.5%,子鼠双肺重量较对照组显著降低(P＜0.01);实验组有膈疝形成和无膈疝形成者的肺组织均发育不良,处于假腺体期和原始肺小管期;与对照组比较,实验组胎肺组织中SP-B、SP-C和VEGF表达水平均显著下调(P＜0.01),且与膈疝形成与否无关.结论 采用除草醚能在小鼠成功建立CDH模型,具有简便、成功率高的优点,为深入研究CDH发病机制及其治疗提供了新的手段.     

先天性膈疝大鼠模型肺内转化生长因子-β1表达的动态观察

目的 观察转化生长因子-β1(TGF-β1)在先天性膈疝(CDH)模型大鼠胎鼠肺内的表达情况.方法 12只成年雌性SD大鼠孕后9.5 d随机分为对照组和膈疝组,膈疝组给予Nitrofen125 mg/只灌胃,对照组给予等最食用油灌胃.至孕16 d,各组再随机分为3亚组,分别于孕16、18和21 d对孕鼠行剖宫产,观察胎鼠膈疝形成情况,记录孕21 d胎鼠体重和肺重;光镜下进行组织学观察和测量,免疫组织化学染色和图像分析对胎鼠肺内TGF-β1表达进行定位、定量分析.结果 膈疝组共有32只胎鼠形成膈疝,致畸率为72.7%.膈疝组孕21 d亚组肺重与体重之比小于相应时段对照组之亚组(P<0.01).膈疝组各亚组均存在肺发育不良,其发育明显滞后于对照组的相应亚组.两组TGF-β1免疫组织化学染色呈细胞质阳性.膈疝组各时期胎肺中TGF-β1的表达均强于对照组(P<0.01).结论 Nitrofen诱导的大鼠CDH模型在膈肌闭合之前,肺组织形态已有发育不良的表现.TGF-β1可能是导致肺发育不良的重要因子之一.     

先天性膈疝模型胎鼠肺发育不良的超微结构动态观察

目的 探讨先天性膈疝(CDH)肺发育不良的机制,研究CDH模型胎鼠肺组织不同发育阶段的超微结构特点.方法 将7只Sprague-Dawley(SD)孕鼠用随机数字表法分为两组,膈疝组(n=4):于孕9.5 d用Nitrofen(125 mg/只,溶于2 ml橄榄油中)灌胃1次,分别于SD鼠孕16 d,18 d和21 d...     

10例先天性膈疝修补术的麻醉体会

先天性膈疝的发生率是 1/4 0 0 0～ 1/5 0 0 0 ,男女之比为 2∶1。先天性膈疝是由于腹腔内脏器疝入胸腔 ,使胸腔容积变小 ,肺萎缩及纵隔摆动 ,影响气体交换 ,可出现不同程度呼吸困难和缺氧 ,麻醉及手术死亡率高达 2 3 %。适时手术是处理先天性膈疝主要措施 ,而先天性膈疝病理生理改变给麻醉处理带来了极大的困难 ,现就我院自 1995年以来 10例先天性膈疝修补术麻醉体会报告如下 :1　资料与方法1.1　一般资料 :10例中男 7例 ,女 3例。左膈疝 9例 ,右膈疝 1例 ,入院时年龄 2～ 15天 ,胎龄均为 3 7～ 40周 ,手术方式左膈疝经腹、右膈疝经右胸修…     

产时子宫外胎儿膈疝手术的麻醉一例

孕妇,37岁,75 kg,孕7月时产前检查发现胎儿膈疝,现孕38⁺²周入院。B超示单胎妊娠,胎儿膈疝,胃泡及部分肠管位于左侧胸腔,心脏右移,右肺发育基本正常,左肺状态不确定,余未发现异常。胎盘附于子宫左后侧壁。鉴于胎儿出生自主呼吸建立后胸-腹腔压力差增加,可能使膈疝病情加重,因此在产时胎儿未建立自主呼吸、利用胎盘循环行胎儿膈疝修补术以增加新生儿存活机率。与产妇反复沟通后,拟行剖宫产术+产时宫外胎儿膈疝修补术。产妇既往无特殊病史,无椎管内麻醉禁忌证。入室后开放静脉输液,监测ECG、NIBP、SpO₂、右侧桡动脉有创测压。L_2～3间隙硬膜外穿刺置管,给予2%利多卡因5     

食管癌贲门癌术后膈疝的早期诊治

1995年 9月至 2 0 0 2年 8月 ,我们共诊治食管癌术后膈疝6例 ,现将体会报道如下。临床资料　本组 6例均为食管癌术后病人。手术后 4～12d确诊为膈疝后全部经原切口入胸行膈疝修补术。术中发现 ,6例均有横结肠和大网膜疝入胸腔 ,合并有脾脏和部分空肠疝入 2例 ;伴有左肺下叶不张 2例。 4例经膈胃孔的胃前方疝入 ,2例经三角区疝入。除 1例为线结松脱外 ,其余 5例均为缝线切割 (4例线结遗留在膈肌侧、1例遗留在胃壁侧 )。本组 6例均治愈出院。讨论　有下列情况者提示早期膈疝的存在 :(1)消化道不完全梗阻症状 ,排便存在 ,但排气明显减少。 (2 )…     

胎儿先天性膈疝"子宫外产时处理"麻醉1例

患者,女性,32岁,孕37周,体重68.5 kg,诊断:足月妊娠,胎儿左侧膈疝.拟在全身麻醉下行剖宫产术、维持子宫胎盘循环下行先天性膈疝修补术. 孕28周时,彩超示胎儿左侧胸腔内可见胃泡及部分肠管回声,未见肝脏嵌入影.胎心位于胸腔右侧,心尖指向左侧,双肺受压,右肺约1.9 cm×1.5 cm,左肺约3.9 cm ×1.2 cm.孕期平稳,脐带血检查胎儿染色体核型未见异常.孕37周时,超声示右肺仅增长至约2.4 cm×2.0 cm,胎心仍位于胸腔右侧.核磁共振示胎儿左侧腹腔内容物嵌入胸腔,右肺受压,心脏向右侧移位,未见肝脾嵌入.     

麻醉与外伤性膈疝

胸部或腹部的钝性外伤,能导致膈肌的撕裂和腹内容向胸腔疝出。这类意外绝大多数来自车祸,据加拿大一医院五年的统计,每4,250例因汽车撞伤而住院的病人中就有1例发生隔疝。死亡率约为25%。作者介绍三例创伤性隔疝并提出讨论。发生创伤性膈疝的原因有下列三个因素:(1)由于突然的压力产生了胸腹压力差,“喘气”反射增大了压力差。(2)胸部受压使膈肌变形,产生了使膈肌断裂的剪断力。(3)膈肌有先天性弱点。由于膈肌的右面受到肝脏保护,约有95%的外伤性膈疝发生在左面膈肌。胃、脾、横结肠和小肠是箝入胸腔最常见的脏器,它引起肺的压缩和不同程度的纵膈移位。由于肺挫伤,气胸或因合并骨折和撕裂所致的急性失血,最后可加重     

汉防己甲素对先天性膈疝大鼠模型胎仔肺内表皮生长因子及其受体的影响和意义

目的 探讨中药成分汉防己甲素（tetrandrine,TET）对大鼠先天性膈疝（congenital diaphragmatic hernia,CDH）模型胎仔肺内表皮生长因子（epidermal growth factor,EGF）及其受体（epidermal growth factor receptor,EGFR）的影响和意义。方法 实验组20只雌性SD大鼠于孕9．5d灌胃给予除草醚115mg／只;对照组4只灌胃给等量食用油。孕18．5d,实验组根据给药不同随机分为生理盐水组（normal solution group,NS组）、地塞米松组（dexamethasone group,Dex组）、汉防己甲素组（tetrandringe group,TET组）、地塞米松＋汉防己甲素组（D＋T组）,每组5只。孕21．5d对所有孕鼠行刮宫产,取出胎鼠两侧肺组织行大体观察、HE染色、EGF、EGFR免疫组织化学染色和图像分析。结果 正常对照组共产胎仔36只,无隔疝形成。实验组共产胎仔137只,CDH形成64只,致畸率46．7％。在Dex组、TET组和T＋D组,肺组织处于原始肺泡期或进一步成熟。EGF在NS组、Dex组、TET组、D＋T组及对照组的表达量依次递减（P〈0．05）,而EGFR在NS组、Dex组、TET组、D＋T组和对照组的表达量依次递增（P〈0．05）。结论 TET可使CDH胎鼠肺内EGF表达高峰提前,使EGFR表达上调,TET和Dex联合作用对促进EGF表达高峰提前及EGFR表达上调具有明显的协同效应。TET可以通过调节EGF及EGFR在肺内的表达而实现其促进肺组织细胞发育分化和改善肺血管构型的效应。     

心脏彩色多普勒超声用于胸腔镜手术中新生儿持续肺动脉高压的观察

正在新生儿早期,低氧、高碳酸血症、酸中毒、感染、低温和早产等因素可使肺动脉压突然增高,血流经再开放的卵圆孔或动脉导管发生右向左分流,称为新生儿持续肺动脉高压,又称持续胎儿循环,在出生前10d内尤其容易发生~([1])。临床主要表现为严重低氧血症,如此则形成恶性循环。先天性食管闭锁和食管气管瘘多合并吸入性肺炎,先天性膈疝常并发肺发育不良,两种患儿亦有不少早产,胸腔     

Experimentally induced congenital diaphragmatic hernia in rats

Experiments to induce congenital diaphragmatic hernia (CDH) in rats, by means of administering a single dose of 2,4-dichlorophenyl-P-nitrophenyl (Nitrofen) on the 10th day of gestation, are reported here. Previously, congenital diaphragmatic hernia has been induced in sheep late in fetal development, and in mice early in gestation. The rat model, including a control group, was used to evaluate lung development and the presence of lung hypoplasia by morphometrical analysis. It was found that the single dose of Nitrofen, given 5 days before the normal closure of the diaphragm in the rat, leads to a high incidence of diaphragmatic hernia, mainly on the right side, and highly abnormal lung development (hypoplasia) comparable to the human situation. Both the lung weight/body weight index as well as the radial alveolar count were significantly lower in animals with CDH (P less than .05). This animal model offers a good opportunity to study abnormal lung development in relation to ventilatory capacity and pulmonary vascular reactivity.     

The effect of gastroschisis on experimental diaphragmatic hernia in fetal rabbits

Purpose

In this study, the authors analyzed the effect of experimentally induced gastroschisis on pulmonary hypoplasia in fetal rabbits with congenital diaphragmatic hernia (CDH).

Methods

Twenty-three pregnant rabbits underwent fetal surgery on gestational day 24 through 27. A left diaphragmatic hernia was created in 1 fetus (DH group) from each rabbit, and a left diaphragmatic hernia with gastroschisis was created in another fetus (GS group). The fetuses were delivered on gestational day 27 through 33. Histologic and morphometric examination of the lungs in each group was done.

Results

In the DH group, the lungs were hypoplastic with a decrease in lung weight to body weight ratio and an increase pulmonary arterial medial wall thickness. The alveolar septae were markedly thickened with increased interstitial tissue and diminished alveolar air spaces. In the GS group, the alveolar septae were thickened but narrower than those of DH group, and air spaces were increased. The pulmonary arterial wall was markedly thickened in the DH group but only slightly thickened in the GS group.

Conclusions

Pulmonary hypoplasia seen in newborn rabbits after experimentally induced diaphragmatic hernia is less severe in those rabbits with both gastroschisis and DH.     

The effect analysis and comparison between gastroschisis and tracheal ligation on experimental diaphragmatic hernia in fetal rabbits

Purpose

The authors analyzed and compared the effects of experimentally induced gastroschisis and tracheal ligation on pulmonary hypoplasia in fetal rabbits with congenital diaphragmatic hernia.

Methods

Twenty-three pregnant rabbits underwent fetal surgery on gestational day 24 through 27. Left diaphragmatic hernia was created in 1 fetus (DH group) from each rabbit, and a left diaphragmatic hernia with gastroschisis (GS group) or tracheal ligation (TL group) was created in another fetuses. The fetuses were delivered on gestational day 27 through 33. Histologic and morphometric examination of the lungs were performed in each group.

Results

In the DH group, the lungs were hypoplastic with a decrease in lung weight to body weight ratio and an increase in pulmonary arterial wall thickness. The alveolar septae were markedly thickened and diminished alveolar air spaces. In GS and TL groups, the alveolar septae were thickened but narrower than those of the DH group, air spaces were increased, and the pulmonary arterial wall was only slightly thickened.

Conclusions

Pulmonary hypoplasia seen in newborn rabbits after experimentally induced diaphragmatic hernia is less severe in those rabbits with concurrently made gastroschisis or tracheal ligation. From the histologic viewpoint, the effects of gastroschisis and tracheal ligation on pulmonary hypoplasia in diaphragmatic hernia have no differences.     

The kidney in the fetal rat model of congenital diaphragmatic hernia induced by nitrofen.

This paper explores whether there is a correlation between kidney and lung growths in an experimental model of congenital diaphragmatic hernia (CDH) induced by intragastric administration of Nitrofen (115 mg/kg) in olive oil on time-dated pregnant Wistar rats at the 9th day of gestation. For comparison we used pregnant rats treated with olive oil alone. Twenty-nine normal fetuses from 3 control rats and 24 left CDH fetuses from 6 Nitrofen rats were studied. Fetal (3.6 +/- 0.8 v 4.9 +/- 0.4 g, P < .001) and total lung (2% +/- 0.5% v 2.6% +/- 0.3% of body weight, P < .001) weights were significantly decreased in animals with CDH. Kidneys were also smaller in CDH animals although not significantly (0.7% +/- 0.1% v 0.8% +/- 0.1% of body weight, P = .05) and were also histologically immature. Regression of kidney weight on body weight for both groups yielded regression lines that were identical at analysis of covariance and all data points from the CDH group were within the control group 95% confidence limits. After converting raw data into lung/body and kidney/body weight ratios, no inverse correlation suggesting a feedback mechanism of growth regulation between both organs could be found. Since nitrofen acts through modifications of the thyroid hormone status in both dam and fetus, altered maturation of several organs should be expected although some of them, like the lung, are the leading targets. The present CDH rodent model is probably different from the human malformation in spite of the striking anatomic similarities between them.(ABSTRACT TRUNCATED AT 250 WORDS)     

Nitrofen-induced congenital malformations of the heart and great vessels in rats: an animal model

BACKGROUND: Nitrofen (2,4-dichloro-4'-nitrodiphenyl ether), a diapheny ether herbicide, is known to induce in rat fetuses a variety of congenital cardiovascular anomalies, together with diaphragmatic hernia and hydronephrosis. The purpose of the current study was to produce congenital cardiovascular anomalies in rat fetuses by oral nitrofen administration at the indicated doses and days of gestation, and to determine the characteristics of resulting nitrofen-induced cardiovascular anomalies. METHODS: All the observed fetuses were removed from pregnant Sprague-Dawley rats killed on the 21st day of gestation. They were preserved in 10% formalin, and dissection for examination was carried out under a dissecting microscope. RESULTS: The following results were based on dissecting microscopic findings of 482 offspring: (1) The 11th day of gestation was the most sensitive for nitrofen induction of congenital cardiovascular anomalies. The incidence of these was dose related. (2) Ventricular septal defect was the most common single cardiovascular anomaly, representing more than half of all such irregularities. The next most common were aortic arch anomalies and tetralogy of Fallot. (3) Cardiac anomalies derived from infundibular maldevelopment such as tetralogy of Fallot and pulmonary atresia with ventricular septal defect were observed only in the group treated with nitrofen on the 11th gestational day. (4) Aortic arch anomalies were very frequent; the great majority were anomalous right subclavian artery with left aortic arch. CONCLUSION: This animal model is suitable for further embryological investigation of the development of congenital cardiovascular anomalies.     

Cell proliferation and apoptosis in experimental lung hypoplasia

BACKGROUND/PURPOSE: Current treatment for lethal pulmonary hypoplasia in congenital diaphragmatic hernia (CDH) may be hampered by uncertainty over its origin. Herniation of abdominal organs into the chest was thought to produce lung hypoplasia by compression. Experimental CDH models suggest that disturbed lung growth precedes these events. Mammalian development comprises cell differentiation, proliferation and programmed cell death or apoptosis. Could lung hypoplasia in CDH result from alterations in these processes well before visceral herniation takes place? The aim of this study was to compare cell proliferation and apoptosis in normal and hypoplastic embryonic lungs before normal diaphragmatic closure using a CDH model. METHODS: Sprague-Dawley rats were given 100 mg of nitrofen on day 9.5 of pregnancy to create lung hypoplasia and CDH in newborns (term, 22 days). Control rats received olive oil. Cell proliferation in embryonic lung specimens was measured by bromodeoxyuridine (BrdU) incorporation at 13.5 to 15.5 days' gestation, before normal diaphragmatic closure in this species (day 16.5). Apoptosis was measured by the in situ end-nick labelling (TUNEL) method in lung sections obtained from rat embryos of 13.5 to 16.5 days' gestation. RESULTS: High levels of cell proliferation were seen in both normal control and nitrofen-exposed lungs. However, 24 hours before normal diaphragmatic closure, nitrofen-exposed lungs had significant reductions in cell proliferation on day 15.5 of gestation (P = .009 v controls). Apoptosis occurred at low levels throughout the developmental stages examined (< 0.3%) without significant differences encountered between the study groups. CONCLUSIONS: These findings have shown high rates of cell division during normal lung development before diaphragmatic closure. Decreased levels over this critical period in gestation may contribute to early lung anomalies in the nitrofen CDH model. Strategies to promote cell proliferation in the fetal lung may therefore hold future promise in human CDH. Apoptosis appears not to play a major role in hypoplastic lung development. Therapies to inhibit apoptosis would seem unlikely to improve this early lung growth.