Plasma 15-F2t-isoprostane in idiopathic pulmonary arterial hypertension

Background

15-F_2t-isoprostane (15-F_2t-IsoP), a prostaglandin F₂-like compound, is widely recognized as a biomarker of chronic heart failure. This study investigated the potential role and prognostic significance of plasma 15-F_2t-IsoP in patients with idiopathic pulmonary arterial hypertension (IPAH).

Methods

Plasma 15-F_2t-IsoP concentrations were determined in 80 consecutive IPAH patients at the time of their first right heart catheterization, and monitored for 30 ± 12 months. The expression of 15-F_2t-IsoP protein in autopsy lung samples was determined by immunohistochemical staining.

Results

Plasma 15-F_2t-IsoP concentrations were significantly increased in patients with IPAH compared with healthy controls (91 pg/ml vs. 30 pg/ml, respectively; P < 0.001). Patients with baseline 15-F_2t-IsoP concentrations ≥ 97 pg/ml had a significantly lower survival rate than those with lower baseline concentrations (P < 0.001). During follow-up, 15-F_2t-IsoP concentrations in survivors decreased, whereas concentrations in non-surviving patients increased further (P < 0.05). Elevated concentrations of 15-F_2t-IsoP were correlated with a severity of WHO functional class, lower 6-minute walking distance and mixed venous oxygen saturation, higher mean right atrial pressure and brain natriuretic peptide. Multivariate analysis revealed that the plasma 15-F_2t-IsoP concentration was an independent factor associated with mortality. Histological studies showed that the expression of 15-F_2t-IsoP was up-regulated in remodeled pulmonary vessels.

Conclusions

An elevated plasma 15-F_2t-IsoP concentration and a further increase during follow-up may be a risk factor for higher mortality in patients with IPAH.     

Analysis of pulmonary heme oxygenase-1 and nitric oxide synthase alterations in experimental hepatopulmonary syndrome

BACKGROUND & AIMS: Cirrhosis and portal hypertension due to chronic common bile duct ligation reproduce the features of human hepatopulmonary syndrome, whereas portal hypertension alone due to partial portal vein ligation does not. Nitric oxide contributes to experimental hepatopulmonary syndrome, but the nitric oxide synthase forms involved remain controversial. Recently, increased pulmonary heme oxygenase-1 expression and carbon monoxide production have also been found after common bile duct ligation. Our aim was to explore the role of the heme oxygenase-1/carbon monoxide pathway in the pathogenesis of experimental hepatopulmonary syndrome. METHODS: Pulmonary heme oxygenase-1 expression and distribution were assessed in sham; 3-week partial portal vein ligation; and 1-, 2-, 3-, 4-, and 5-week common bile duct ligation animals by Northern, Western and immunohistochemical analysis relative to endothelial and inducible nitric oxide synthase levels and to hepatopulmonary syndrome development. In vivo heme oxygenase enzyme inhibition with tin protoporphyrin IX in common bile duct ligation animals was used to define effects on intrapulmonary vasodilatation and arterial blood gases. RESULTS: Heme oxygenase-1 expression in pulmonary intravascular monocytes/macrophages and arterial carboxyhemoglobin levels increased progressively from 3 to 5 weeks after common bile duct ligation relative to controls (5-week protein levels were 15.94 +/- 1.75-fold those of sham animals; P < 0.001). Inducible nitric oxide synthase increased transiently in pulmonary intravascular monocytes/macrophages in 3-week common bile duct ligation animals, whereas pulmonary microvascular endothelial nitric oxide synthase increases began at 2 weeks and correlated with the onset of hepatopulmonary syndrome. Tin protoporphyrin treatment normalized carboxyhemoglobin and improved arterial blood gases and intrapulmonary vasodilatation, reflecting partial reversal of hepatopulmonary syndrome. CONCLUSIONS: The heme oxygenase-1/carbon monoxide system is an important contributor to the progression of experimental hepatopulmonary syndrome in addition to alterations in the endothelial nitric oxide synthase/nitric oxide pathway.     

Differential involvement of nitric oxide signaling in dopamine and PACAP stimulation of growth hormone release in goldfish

Previous studies in goldfish pituitary cells have shown that nitric oxide synthase (NOS)/nitric oxide (NO) signaling is involved in mediating the growth hormone (GH) release response to gonadotropin-releasing hormones. In this study, the involvement of this signaling pathway in mediating the action of two cAMP-mobilizing neuroendocrine stimulators of GH release, pituitary adenylate cyclase-activating polypeptide (PACAP) and dopamine (DA), was investigated in cell column perifusion experiments with primary cultures of dispersed pituitary cells. GH responses to PACAP were unaffected by three NOS inhibitors, aminoguanidine hemisulfate, 1400W and 7-nitroindazole (7-Ni). PACAP-stimulated GH release was also not reduced by two NO scavengers, rutin hydrate and PTIO, but NO-donor sodium nitroprusside (SNP)-elicited GH release was additive to the GH response to PACAP. In contrast, DA-induced GH secretion was reduced by 7-Ni, rutin hydrate and PTIO while not being additive to the GH response induced by SNP. These results indicate that although both PACAP and DA stimulation of acute GH release involve activation of adenylate cyclase/cAMP, DA- but not PACAP-signaling also utilizes the NOS/NO second messenger system.     

Urates in exhaled breath condensate as a biomarker of control in childhood asthma

Objective: The aim of this study was to (1) investigate the possibility to use urates in exhaled breath condensate (EBC) as a biomarker of airway inflammation and control in childhood asthma and (2) explore their association with other biomarkers of airway inflammation and clinical indices of asthma control (Asthma Control Test [ACT], quality of life [PAQLQ], lung function, prn beta-agonist use, time from last exacerbation [TLE]. Methods: This cross-sectional study comprised 103 consecutive patients (age 6–18 years) divided in groups of uncontrolled ([NC], n?=?53) and controlled asthma ([C], n?=?50). Measured lung function and biomarkers included: spirometry, eosinophilic cationic protein (ECP), high-sensitivity C-reactive protein (hs-CRP), exhaled NO (F_ENO), pH and urates in EBC and exhaled breath temperature (EBT). Results: Statistically significant differences were found between groups for EBC urates, EBC pH and EBT (NC versus C: EBC urates, median [IQR], µmol/L; 10 [6] versus 45 [29], p?<?0.001; EBC pH, mean [SD], 7.2 [0.17] versus 7.33 [0.16], p?=?0.002; EBT mean [SD], °C; 34.26 [0.83], versus 33.90 [0.60], p?=?0.014). EBC urates showed significant association with TLE and F_ENO (r?=?0.518, p?<?0.001; r?=?0.369, p?=?0.007, respectively) in NC, and EBC pH (r?=?0.351, p?<?0.001), FEV₁ (r?=?0.222, p?=?0.024), ACT (r?=?0.654, p?<?0.001), PAQLQ (r?=?0.686, p?<?0.001) and prn salbutamol use (r?=??0.527, p?<?0.001) in all asthmatics. Conclusion: In our study, EBC urates were found to be the best single predictor of asthma control and underlying airway inflammation. Our results provide evidence supporting the potential utility to use EBC urates as an additional non-invasive biomarker of control in childhood asthma.     

Selective modulation of endogenous nitric oxide formation in ischemia/reperfusion injury in isolated rat hearts

The role of nitric oxide (NO) in ischemia/reperfusion injury is controversial. We tested the role of inducible NOS (iNOS) in the ischemia/reperfusion injury in isolated rat hearts using the selective iNOS inhibitor S-methylisothiourea sulfate (SMT) and the non-selective NOS inhibitor N^G-nitro-L-arginine methyl ester (L-NAME). After 15 min of stabilization in Langendorff mode, hearts were perfused either with normal Krebs-Henseleit buffer, buffer containing 100 μM L-NAME, 0.5 μM SMT or 50 μM SMT for 5 min and were subjected to 25 min of ischemia followed by 30 min of reperfusion. Left ventricular developed pressure (LVDP) and total coronary flow (CF) were recorded continuously. After ischemia/reperfusion, a marked expression of iNOS protein was demonstrated by Western blotting, while virtually no iNOS protein was present in hearts without ischemia/reperfusion. Regional myocardial blood flow (RMBF) was measured with colored microspheres. Coronary vasoactive concentration of L-NAME and SMT depressed myocardial function as shown by decreased LVDP, dP/dt_max and coronary .ow before ischemia. After ischemia the recovery of the total CF was impaired in L-NAME and 50 μM SMT pretreated hearts which was related to homogenous RMBF decrease in the right and left ventricle compared to that in control group. Low concentration SMT (0.5 μM) showed no coronary vasoactive effects before ischemia and attenuated ischemia/reperfusion injury indicated by lower ischemic contracture at 25 min of ischemia and reduced CK and LDH release during reperfusion. Thus, NOS inhibition did not affect blood flow distribution in rat hearts either in the pre-ischemic or reperfusion period. Selective iNOS inhibition reduced ischemic injury by reducing ischemic contracture and CK as well as LDH release during reperfusion. Received: 20 March 2002, Returned for 1. revision: 8 April 2002, 1. Revision received: 14 August 2002, Returned for 2. revision: 5 September 2002, 2. Revision received: 3 February 2003, Accepted: 18 February 2003, Published online: 16 April 2003     

梅毒患者血清一氧化氮和一氧化氮合酶水平测定

目的　检测梅毒螺旋体感染者血清中一氧化氮 (NO)和一氧化氮合酶 (NOS)的水平。方法　用分光光度法测定血清中NO水平和NOS活性 ,血清中NO3 和NO2 总量代表体内NO水平 ,NOS催化L 精氨酸和氧的反应生成NO的多少代表血清NOS活性。结果　梅毒患者NO浓度为 115± 36 3nmol/L ,NOS活性为 35 8± 7 3U/ml,二者均远远高于正常对照组。结论　梅毒螺旋体的感染引起患者体内NO水平和NOS活性升高 ,NO在梅毒感染中可能发挥重要的作用。     

NO-releasing xanthine KMUP-1 bonded by simvastatin attenuates bleomycin-induced lung inflammation and delayed fibrosis

Background and purposePulmonary fibrosis (PF) is a progressing lung injury initiated by pulmonary inflammation (PI). Bleomycin (BLM) is the most common pathogenesis of PF through early PI and extensive extracellular matrix deposition. This study is aimed to determine whether NO-releasing KMUP-1 inhibits PI and PF, and if so, the benefits of KMUP-1S resulted from simvastatin (SIM)-bonding to KMUP-1.Experiment approachC57BL/6 male mice were intra-tracheally administered BLM (4 U/kg) at day 0. KMUP-1 (1–5 mg/kg), KMUP-1S (2.5 mg/kg), SIM (5 mg/kg), Plus (KMUP-1 2.5 mg/kg + SIM 2.5 mg/kg), and clarithromycin (CAM, 10 mg/kg) were orally and daily administered for 7 and 28 days, respectively, to mice, sacrificed at day-7 and day-28 to isolate the lung tissues, for examining the inflammatory and fibrotic signaling and measuring the cell population and MMP-2/MMP-9 activity in broncholaveolar lavage fluid (BAL).Key resultsKMUP-1 and KUP-1S significantly decreased neutrophil counts in BAL fluid. Fibroblastic foci were histologically assessed by H&E and Masson's trichrome stain and treated with KMUP-1 and references. Lung tissues were determined the contents of collagen and the expressions of TGF-β, α-SMA, HMGB1, CTGF, eNOS, p-eNOS, RhoA, Smad3, p-Smad3, MMP-2 and MMP-9 by Western blotting analyses, respectively. These changes areregulated by NO/cGMP and inhibited by various treatments. KMUP-1 and KMUP-1S predominantly prevented HMGB1/MMP-2 expression at day-7 and reduced TGF-β/phosphorylated Smad3 and CTGF at day-28.Conclusions and implicationsKMUP-1 and KMUP-S restore eNOS, inhibit iNOS/ROCKII/MMP-2/MMP-9, attenuate histologic collagen disposition and reduce BALF inflammatory cells, potentially useful for the treatment of BLM-lung PF.     

硅对大鼠血清一氧化氮合酶及一氧化氮的影响

目的　观察硅 ( Na2 Si O3)对血清中一氧化氮合酶 ( NOS)及一氧化氮 ( NO)浓度的影响 ,探讨其抗动脉粥样硬化 ( AS)的作用。方法　高脂饮食饲养 SD大白鼠造成高脂血症和早期 AS模型 ,造模时以 Na2 Si O3 溶液灌胃 ,1 0 w后比较各组血清中 NOS活性和 NO浓度以及动脉壁形态。结果　与正常对照组比较 ,早期 AS时大鼠血清 NOS活性下降 (分别为 2 9.2 3± 1 .837和 2 7.4 3± 2 .0 0 U/ml,P<0 .0 5) ,NO总浓度增加 (分别为35.71± 1 4.4 7和 1 90 .57± 76 .4 3μmol/L ,P<0 .0 1 )。灌胃 Na2 Si O3 溶液 ( 1 0 mg/k g.d )后 NOS及 NO总浓度均恢复到正常组水平。结论　 Na2 Si O3可调节动脉硬化大鼠体内 NO代谢 ,发挥抗 AS作用     

缺血预处理对大鼠压疮缺血再灌注损伤保护作用的实验研究

目的比较不同缺血处理方法对大鼠皮肤及皮下组织的保护作用,为临床判断压疮损伤的程度及压疮干预效果提供理论依据。方法将60只SD大鼠随机分为对照组（S组）、缺血再灌注组（RI组）和缺血预处理组（IPC组）,每组20只．建立大鼠压疮缺血再灌注损伤处理模型,通过肉眼观察受压程度,检测血清氧自由基的水平,以判断压疮缺血再灌注损伤程度。结果RI组和IPC组大鼠出现I期压疮的发生率为100％。IPC组血清一氧化氮、丙二醛含量高于S组,明显低于RI组．超氧化物歧化酶活性低于S组,明显高于RI组。结论缺血预处理对压疮缺血再灌注损伤具有保护作用。     

Myeloid-derived suppressor cells are increased in frequency but not maximally suppressive in peripheral blood of Type 1 Diabetes Mellitus patients

Type 1 Diabetes Mellitus (T1D) results from the destruction of insulin-producing beta cells in the pancreas by autoreactive T cells. Myeloid derived suppressor cells (MDSCs) are a recently identified immune cell subset that down-regulate T cells. Whether defects in MDSC numbers or function may contribute to T1D pathogenesis is not known. We report here that MDSCs are unexpectedly enriched in peripheral blood of both mice and patients with autoimmune diabetes. Peripheral blood MDSCs from T1D patients suppressed T cell proliferation in a contact-dependent manner; however, suppressive function could be enhanced with in vitro cytokine induction. These findings suggest that native T1D MDSCs are not maximally suppressive and that strategies to promote MDSC suppressive function may be effective in preventing or treating T1D.