先天性心脏病合并肺动脉高压患者肺组织一氧化氮合酶的表达

目的：通过观察先天性心脏病合并肺动脉高压患者肺组织内皮型一氧化屡合酶（eNOS)的表达，了解其肺血管内皮细胞功能有否异常。方法：32例先天性心脏病患者分为2组，组I：合并肺动脉高压患者（n=16);组Ⅱ：未合并肺动脉高压患者（n=16)。在心内直视术下，取少许右肺中叶组织，利用免疫组织化学和逆转录－聚合酶链反应（RT－PCR）技术，对eNOS进行半定量分析。结果：组Ⅱ患者肺血管内皮细胞内eNOS免疫染色比组I明显增强（F＝93．98，P＜0．01）；组Ⅱ患者肺血管内皮细胞内eNOSmRNA表达比组I明显增高（F＝58．76，P＜0．01）。结论：先天性心脏病合并肺动脉高压患者的eNOS表达减少，造成内源性一氧化氮（NO）生成不足，为该类患者吸入NO治疗肺动脉高压提供了理论依据。     

Interactions between inducible nitric oxide synthase and heme oxygenase-1 in glomerulonephritis

BACKGROUND: In anti-glomerular basement membrane (GBM) nephritis, inducible nitric oxide synthase (iNOS) and heme oxygenase (HO-1) are co-induced. Moreover, in glomerular mesangial cells iNOS-derived nitric oxide (NO) production stimulates HO-1 while HO-1 activation reduces iNOS expression/activity. These observations prompted us to explore regulatory interactions between iNOS and HO-1 in anti-GBM nephritis. METHODS: Rats with anti-GBM nephritis were pretreated with the iNOS inhibitor l-N6-(1-iminoethyl) lysine (L-NIL) or with the HO-1 inducer hemin. Glomerular HO-1 levels were assessed by Western blot analysis. iNOS activity was assessed by calculating conversion of l-arginine to l-citrulline. RESULTS: iNOS inhibition reduced glomerular HO-1 levels without altering the inflammatory response to anti-GBM antibody induced injury. Induction of HO-1 reduced glomerular iNOS activity. CONCLUSIONS: In anti-GBM nephritis iNOS up-regulates HO-1 presumably via high output NO production. Suprainduction of HO-1 attenuates iNOS activity. This negative feedback interaction points to HO-1 as a target for pharmacologic manipulation to reduce activity of prooxidant heme containing enzymes such as iNOS.     

Genetic polymorphisms of angiotensin system genes in congenital diaphragmatic hernia associated with persistent pulmonary hypertension

Background/purpose

The renin-angiotensin system plays an important role in pulmonary artery remodelling. Several polymorphisms of genes encoding for components of the renin angiotensin system such as the angiotensin converting enzyme (ACE), the angiotensinogen (AGT) gene, and the angiotensin II type 1 receptor (ATIR) have been associated with the development of pulmonary hypertension. The aim of this study was to investigate the ACE I/D genotype, the M²³⁵ T polymorphism of the AGT gene and the A¹¹⁶⁶ C polymorphism of AT1R in the lungs of congenital diaphragmatic hernia (CDH) complicated by persistent pulmonary hypertension (PPH) in the newborn.

Methods

Genomic DNA was extracted from archival paraffin-embedded lung tissue from 13 newborns with CDH complicated by PPH and from 9 controls. Genotyping for the I/D-ACE, the M²³⁵ T-AGT, and the A¹¹⁶⁶ C-ATIR gene polymorphisms were determined by a polymerase chain reaction-based method with appropriate restriction digest when required.

Results

In controls, ACE genotype distribution of DD, ID, and II was 11%, 33%, and 55%, respectively, whereas in CDH it was 70%, 15%, and 15%, respectively. The ACE-DD genotype was significantly higher in CDH compared with controls (P < .05). In CDH samples, the prevalence of AGT-MM genotype was lower (8% v. 33%; P < .05), whereas the AGT-TT genotype was higher (61% v. 22%; P < .05) compared with controls. There were no differences in allele frequencies of AT1R between CDH patients and controls.

Conclusions

These data suggest that D allele of the ACE gene insertion/deletion polymorphism and angiotensinogen M²³⁵ T polymorphism may be associated with PPH in newborns with congenital diaphragmatic hernia.     

左旋精氨酸恢复eNOS和iNOS平衡并抑制肺动脉高压的研究

目的 探讨诱导型一氧化氮合酶(iNOS)在中、晚期肺动脉高压(PH)发病中的作用机制及左旋精氨酸 (L-Arg)对其产生的影响.方法 30只雄性SD大鼠随机均分为5组,对照组(C组)、MCT3组(M3组)、MCT5组(M5组)、L-Arg3/MCT3组(L3组)、L-Arg5/MCT5组(L5组).除C组外其他组大鼠均用野百合碱一次性腹腔注射诱导PH模型.此后L3组和L5组分别连续每天腹腔注射L-Arg 3周和5周,M3组和M5组分别连续每天腹腔注射与L-Arg等量的生理盐水3周和5周,C组连续每天腹腔注射与L-Arg等量的生理盐水共5周.实验周期结束则用右心导管法测定右心室收缩压(RVSP),间接反映肺动脉压力,然后取大鼠肺组织做免疫组化,检测各组iNOS、内皮一氧化氮合酶(eNOS)和弹性蛋白(elastin)的表达变化.结果 M3和M5组中iNOS和elastin的表达明显高于C组,而eNOS表达明显少于C组;L3和L5组iNOS和elastin的表达少于相应M3和M5组,但L5组两种蛋白表达仍高于C组,L3和L5组eNOS的减少明显比相应M3和M5组少,但不及C组.结论 PH形成的中、晚期,肺组织中eNOS表达减少,而此时iNOS的表达增高可能产生大量一氧化氮(NO),但并没有改善PH的病情,而L-Arg能够恢复eNOS和iNOS之间的平衡并有效抑制PH的进展.     

Use of prostaglandin E1 to treat pulmonary hypertension in congenital diaphragmatic hernia

Background/Purpose

Prostaglandin E1 (PGE) has been used to maintain ductus arteriosus patency and unload the suprasystemic right ventricle (RV) in neonates with congenital diaphragmatic hernia (CDH) and severe pulmonary hypertension (PH). Here we evaluate the PH response in neonates with CDH and severe PH treated with PGE.

肝硬变门静脉高压症患者血红素氧化酶-1的表达

目的　探讨肝硬变门静脉高压症患者脾脏及脾血管血红素氧化酶 (HO ) 1mRNA的表达。方法　应用原位杂交方法检测 2 0例肝硬变门静脉高压症患者脾脏、脾动脉、脾静脉组织HO 1mRNA的表达 ,以 12例脾破裂患者作对照。结果　对照组仅有 4例脾组织可见弱阳性表达 ,平均阳性染色指数为 0 .0 5± 0 .0 1,其脾动、静脉组织未见HO 1mRNA表达。肝硬变门静脉高压症组 18例脾脏HO 1mRNA阳性表达 ,平均阳性染色指数为 0 .68± 0 .12 ,显著高于对照组 (P <0 .0 0 1)。脾动、静脉HO 1mRNA全部表达者 15例 ,脾动、静脉阳性染色指数分别为 0 .5± 0 .1与 0 .5 6± 0 .1,两者差异无显著性 ,(P >0 .0 5 )。结论　肝硬变门静脉高压症合并多种应激原刺激患者HO 1mRNA表达增强 ,HO 1及其代谢产物可能参与门静脉高压症多种病理过程。     

Enhanced expression of vascular endothelial growth factor in lungs of newborn infants with congenital diaphragmatic hernia and pulmonary hypertension

BACKGROUND: Pulmonary hypoplasia accompanied by pulmonary hypertension resistant to treatment is an important feature of congenital diaphragmatic hernia (CDH). The pathogenesis of the pulmonary vascular abnormalities in CDH remains to be elucidated at the molecular level. Vascular endothelial growth factor (VEGF), an endothelial cell specific mitogen, is known to play a role in pulmonary angiogenesis and vascular remodelling but there are no data on VEGF expression in patients with CDH. METHODS: Necroscopic lung specimens from 21 patients with CDH with lung hypoplasia and from seven age matched control newborn infants without lung hypoplasia were processed for immunohistochemical analysis using affinity purified anti-human VEGF antibodies. All the cases of CDH had pulmonary hypoplasia, indicated by a lung/body weight index of 200 microm) and small (<200 microm) pulmonary arteries, the most intense staining being in the medial smooth muscle cells of the small pulmonary arteries. Endothelial cells were positive for VEGF staining in patients with CDH but not in controls. CONCLUSIONS: This is the first study of VEGF expression in newborn infants with CDH. Increased levels of VEGF, especially in the small, pressure regulating pulmonary arteries, point to a potential role in vascular remodelling. This may reflect an unsuccessful attempt by the developing fetus to increase the pulmonary vascular bed in the hypoplastic lungs to alleviate the associated pulmonary hypertension.     

Lack of endothelial nitric oxide synthase promotes endothelin-induced hypertension: lessons from endothelin-1 transgenic/endothelial nitric oxide synthase knockout mice

Endothelin-1 (ET-1) is one of the most potent biologic vasoconstrictors. Nevertheless, transgenic mice that overexpress ET-1 exhibit normal BP. It was hypothesized that vascular effects of ET-1 may be antagonized by an increase of the endothelial counterpart of ET-1, nitric oxide (NO), which is produced by the endothelial NO synthase (eNOS). Therefore, cross-bred animals of ET transgenic mice (ET+/+) and eNOS knockout (eNOS-/-) mice and were generated, and BP and endothelial function were evaluated in these animals. Endothelium-dependent and -independent vascular function was assessed as relaxation/contraction of isolated preconstricted aortic rings. The tissue ET and NO system was determined in aortic rings by quantitative real-time PCR and Western blotting. Systolic BP was similar in ET+/+ and wild-type (WT) mice but was significantly elevated in eNOS-/- mice (117 +/- 4 mmHg versus 94 +/- 6 mmHg in WT mice; P < 0.001) and even more elevated in ET+/+ eNOS-/- cross-bred mice (130 +/- 4 mmHg; P < 0.05 versus eNOS-/-). Maximum endothelium-dependent relaxation was enhanced in ET+/+ mice (103 +/- 6 versus 87 +/- 4% of preconstriction in WT littermates; P < 0.05) and was completely blunted in eNOS-/- (-3 +/- 4%) and ET+/+ eNOS-/- mice (-4 +/- 4%), respectively. Endothelium-independent relaxation was comparable among all groups. Quantitative real-time PCR as well as Western blotting revealed an upregulation of the aortic ET(A) and ET(B) receptors in ET+/+ eNOS-/-, whereas eNOS was absent in aortic rings of eNOS-/- and ET+/+ eNOS-/- mice. ET-1 aortic tissue concentrations were similar in WT mice and ET+/+ eNOS-/- mice most probably as a result of an enhanced clearance of ET-1 by the upregulated ET(B) receptor. These data show for the first time that in transgenic mice that overexpress human ET-1, additional knockout of eNOS results in a further enhancement of BP as compared with eNOS-/- mice. The human ET+/+ eNOS-/- mice therefore represent a novel model of hypertension as a result of an imbalance between the vascular ET-1 and NO systems.     

门静脉高压大鼠血红素氧化酶-1mRNA的表达

目的：研究门静脉高压与血红素氧化酶（HO）－1mRNA表达的关系。方法：建立大鼠门静脉部分缩窄模型，应用原位杂交方法检测大鼠肝、脾及脾静脉HO－1mRNA的表达。结果：对照组12只大鼠所检组织均未见HO－1mRNA表达。门静脉高压组有15只大鼠脾脏HO－1mRNA呈阳性表达（83．3％），10只大鼠脾静脉呈阳性表达（55．6％）；肝组织未见HO－1mRNA表达。结论：门静脉高压大鼠处于应激状态，其脾脏及脾静脉HO－1mRNA表达增强，其代谢产物可能加剧门静脉高压。     

Inhaled nitric oxide with early surgery improves the outcome of antenatally diagnosed congenital diaphragmatic hernia

Background/Purpose: The outcome of antenatally diagnosed congenital diaphragmatic hernia (CDH) has remained poor despite aggressive therapeutic strategies. Since 1996, the authors have used a new approach including early surgery and inhaled nitric oxide (iNO). The aim of this study is to determine whether early surgery in combination with iNO improves the clinical outcome of antenatally diagnosed CDH. Methods: From 1988, 40 consecutive neonates with antenatally diagnosed CDH were admitted to the authors' hospital. Ten cases of fatal chromosomal anomalies or major cardiac anomalies were excluded from this study. From 1988 through 1995 (period 1: n = 13), delayed surgery was used in high-risk CDH. From 1996 through 2000 (period 2: n = 17), early surgery in combination with iNO was used. The severity of lung hypoplasia was evaluated using the fetal lung/thorax transverse area ratio (L/T). High-frequency oscillatory ventilation (HFOV) was used routinely during the study periods, and extracorporeal membrane oxygenation (ECMO) was used on basis of conventional entry criteria. The authors compared the clinical outcome, use of ECMO, and the L/T between the 2 periods retrospectively. Results: Patients in the 2 periods were comparable in terms of birth weight, gestational age, and the L/T. The mean age at surgery was 3.1 [plusmn] 4.9 days in period 1, and 0.8 [plusmn] 1.1 days in period 2. Fewer infants in period 2 compared with period 1 were treated with ECMO (period 1, 62% v period 2, 6%; P [lt ].01). There was significant difference in the survival rate between the 2 periods (period 1, 38% v period 2, 94%; P [lt ] .01). Conclusion: Our data suggest that early surgery and iNO improves the outcome and reduces the requirement of ECMO in the treatment of antenatally diagnosed CDH. J Pediatr Surg 37:1188-1190.     

Clinical use of extracorporeal membrane oxygenation in the treatment of persistent pulmonary hypertension following surgical repair of congenital diaphragmatic hernia

The clinical use of extracorporeal membrane oxygenation (ECMO) in the treatment of persistent pulmonary hypertension following surgical repair of congenital diaphragmatic hernia is reported on 11 patients. The patients had a total of 13 treatments; two patients had two treatments. During the same period of clinical use, 122 patients were placed on ECMO for all causes. The indications, results, and complications of the use of ECMO for treatment following surgical repair of congenital diaphragmatic hernia are presented. The reversal of persistent pulmonary hypertension is demonstrated. All patients treated by ECMO for congenital diaphragmatic hernia have survived.