Prognostic value of computed tomography pulmonary angiography indices in patients with cancer-related pulmonary embolism: Data from a multicenter cohort study.

OBJECTIVE: To analyze the prognostic value of pulmonary artery obstruction versus right-ventricle (RV) dysfunction radiologic indices in cancer-related pulmonary embolism (PE). METHODS: We enrolled 303 consecutive patients with paraneoplastic PE, evaluated by computed tomography pulmonary angiography (CTPA) between 2013 and 2014. The primary outcome measure was serious complications at 15days. Multivariate analyses were conducted by using binary logistic and robust regressions. Radiological features such as the Qanadli index (QI) and RV dysfunction signs were analyzed with Spearman's partial rank correlations. RESULTS: RV diameter was the only radiological variable associated with an adverse outcome. Subjects with enlarged RV (diameter>45mm) had more 15-day complications (58% versus 40%, p=0.001). The QI correlated with the RV diameter (r=0.28, p<0.001), left ventricle diameter (r=-0.19, p<0.001), right ventricular-to-left ventricular diameter ratio (r=0.39, p<0.001), pulmonary artery diameter (r=0.22, p<0.001), and pulmonary artery/ascending aorta ratio (r=0.27, p<0.001). A QI≥50% was only associated with 15-day complications in subjects with enlarged RV, inverted intraventricular septum, or chronic cardiopulmonary diseases. The central or peripheral PE location did not affect the correlations among radiological variables and was not associated with clinical outcomes. CONCLUSIONS: Right ventricular dysfunction signs in CTPA are more useful than QI in predicting cancer-related PE outcome.

On the necessity of new decision-making methods for cancer-associated, symptomatic, pulmonary embolism.

BACKGROUND: Acute symptomatic pulmonary embolism (PE) varies in its clinical manifestations in patients with cancer and entails specific issues. The objective is to assess the performance of five scores (PESI, sPESI, GPS, POMPE, and RIETE) and a clinical decision rule to predict 30-day mortality. METHODS: This is an ambispective, observational, multicenter study that collected episodes of PE in patients with cancer from 13 Spanish centers. The main criterion for comparing scales was the c-indices and 95% confidence intervals (CIs) of the models for predicting 30-day mortality. RESULTS: 585 patients with acute symptomatic PE were recruited. The 30-day mortality rate was 21.3 (95% CI; 18.2-24.8%). The specific scales (POMPE-C and RIETE) were equally effective in discriminating prognosis (c-index of 0.775 and 0.757, respectively). None of these best performing scales was superior to the ECOG-PS with a c-index of 0.724. The remaining scores (PESI, sPESI, and GPS) performed worse, with c-indexes of 0.719, 0.705, and 0.722, respectively. The dichotomic "clinical decision rule" for ambulatory therapy was at least equally reliable in defining a low risk group: in the absence of all exclusion criteria, 30-day mortality was 2%, compared to 5% and 4% in the POMPE-C and RIETE low-risk categories, respectively. CONCLUSION: The accuracy of the five scales examined was not high enough to rely on to predict 30-day mortality and none of them contribute significantly to qualitative clinical judgment.

Fetal Val108/158Met catechol-O-methyltransferase (COMT) polymorphism and placental COMT activity are associated with the development of preeclampsia.

OBJECTIVE: To evaluate the association between fetal and maternal catechol-O-methyltransferase (COMT) Val158Met and methyl tetrahydrofolate reductase (MTHFR) C677T functional polymorphisms and preeclampsia, examining its influence on placental COMT and in maternal 2-methoxyestradiol (2-ME) plasma levels. DESIGN: Prospective case-control study. SETTING: University hospital. PATIENT(S): A total of 53 preeclamptic and 72 normal pregnant women. INTERVENTION(S): Maternal and cord blood samples and placental tissue samples were obtained. MAIN OUTCOME MEASURE(S): Maternal and fetal COMT and MTHFR polymorphisms were genotyped. Maternal plasma 2-ME and homocysteine levels, and expression and activity of placental COMT were measured. RESULT(S): The odds ratio for the risk of preeclampsia for fetal COMT Met/Met was 3.22, and it increased to 8.65 when associated with fetal MTHFR TT. Placental COMT activity and expression were influenced by genotype, but COMT activity in preeclamptic placentas did not differ from control pregnancies. There was no association between any genotypes and maternal 2-ME. Homocysteine levels were higher in women with preeclampsia than in normal pregnancies, and were inversely correlated with 2-ME plasma levels, indicating that its altered metabolism may lower COMT activity in vivo. CONCLUSION(S): Fetal Met-Met COMT genotype reduces COMT placental expression and activity in vitro and increases preeclampsia, risk but it does not explain the difference in maternal 2-ME levels between preeclamptic and normal pregnancies. However, the preeclamptic patients had elevated homocysteine levels that correlated inversely with 2-ME, indicating that an altered methionine-homocysteine metabolism may contribute to reduce COMT activity in vivo and explain the decreased levels of 2-ME in preeclamptic women.

2-methoxyestradiol plasma levels are associated with clinical severity indices and biomarkers of preeclampsia.

We investigated whether clinical severity indices and biomarkers for preeclampsia (PE) are associated with low plasmatic 2-methoxyestradiol (2ME) in the third trimester of gestation. Blood was collected from 53 women with PE and 73 control pregnant women before parturition. The concentration of 2ME was significantly higher in controls than in patients with PE (2906.43 ± 200.69 pg/mL vs 1818.41 ± 189.25 pg/mL). The risk of PE decreased as 2ME levels increased. The 2ME values were negatively correlated with systolic peak arterial pressure and proteinuria in PE. Additionally, those women with PE with lower 2ME had a more serious clinical situation and needed a more aggressive therapy. Finally, 2ME levels (in patients with PE and total population) were significantly correlated with concentrations of soluble fms-like tyrosine kinase 1 and placental growth factor . Summarizing, patients with PE had lower 2ME levels that were correlated with different clinical indices and biomarkers of severity, indicating that 2ME could be taken into account for the clinical management of this syndrome.

Sexual dimorphism in renal heme-heme oxygenase system in the streptozotocin diabetic rats.

Heme Oxygenase (HO) -1 and -2 exert antioxidant, cytoprotective and vascular actions in male diabetic rats. However, there is no information about the expression and functional significance of the renal HO system in diabetic females. The present study tested the hypothesis that the HO system is differentially regulated in the kidney of female Sprague Dawley diabetic rats, protecting it from nitrosative and glomerular functional damage. Two weeks after the administration of streptozotocin (STZ; 65 mg/kg. i.p), males (DM) and females (DF) showed hyperglycemia, polyuria and elevated kidney/body weight ratio, compared to their control males (CM) and females (CF). In conscious animals, creatinine clearance was higher (0.5 ± 00 vs. 0.3 ± 00; ml/min/100g BW; p<0.05) and urinary albumin excretion was lower (0.7 ± 0.3 vs 3.1 ± 0.7; mg/day) in DF compared to DM. Acute administration of a HO inhibitor stannous mesoporphyrin (SnMP 40 mol/kg, i.v.) induced a greater renal vasoconstrictor response in DF than in DM. Western blot analysis of renal tissue revealed higher renal cortex HO-1 protein levels in DF compared to all other groups; by immunohistochemistry this induction of HO-1 in DF was localized in tubular segments and glomeruli. Furthermore, renal cortical concentration of nitrosylated protein was higher in DM than in DF animals and inversely related with HO-1 levels in both renal cortex and medulla. These data demonstrate that the HO-1 protein is induced in females, associated with renal vasodilation, decreased renal nitrosative stress and reduced albuminuria, indicating that the HO system is protecting the kidney from diabetes-induced damage specifically in females.

Reactive oxygen and nitrogen species in the renal ischemia/reperfusion injury.

Renal ischemia is the most common cause of acute kidney injury (AKI) still associated with high mortality rates of about 50% in the intensive care unit. Postischemic AKI is characterized by decreased glomerular filtration rate and high renal vascular resistance with endothelial activation and dysfunction, a process of critical importance that is followed by a reduction in microvascular blood flow mainly affecting the renal outer medulla. The pathophysiology of postischemic AKI remains incompletely understood, although it seems to be a phenomenon of altered renal hemodynamics, linked critically to the production of high amounts of nitric oxide and free radicals. On the other hand, and depending on the severity of renal ischemia, tubular epithelial cells undergo a varying degree of necrosis or apoptosis with tubular obstruction followed by both, anatomical and functional recovery. The way in which vascular and tubular epithelium recover determines the final status of the renal function, ranging from full recovery to chronic renal failure and ultimately to end-stage renal disease. In this review we will revise the mechanisms responsible for these pathophysiologic alterations, including the role of heme oxygenase system and sex differences in the susceptibility to ischemic acute renal failure, and we will also review the pre- and postconditioning phenomena, in which brief episodes of ischemia before (pre-conditioning) or after (post-conditioning) the prolonged ischemia have a protective effect on AKI after reperfusion. Interestingly, these protective responses can be elicited by ischemizing distant tissues (remote conditioning). A better understanding of these mechanisms may help to improve the clinical outcome of those patients.

Chronic tempol treatment attenuates the renal hemodynamic effects induced by a heme oxygenase inhibitor in streptozotocin diabetic rats.

Heme oxygenase-1 (HO-1) is induced by oxidative stress and plays an important role in protecting the kidney from oxidant-mediated damage in the streptozotocin (STZ) rat model of type-1 diabetes mellitus (DM-1). HO-derived metabolites, presumably carbon monoxide (CO), mediate vasodilatory influences in the renal circulation, particularly in conditions linked to elevated HO-1 protein expression or diminished nitric oxide (NO) levels. We tested the hypothesis that diabetes increases oxidative stress and induces HO-1 protein expression, which contributes to regulate renal hemodynamics in conditions of low NO bioavailability. Two weeks after the induction of diabetes with STZ (65 mg/kg iv), Sprague-Dawley rats exhibited higher renal HO-1 protein expression, hyperglycemia, and elevated renal nitrotyrosine levels than control normoglycemic animals. In anesthetized diabetic rats, renal vascular resistance (RVR) was increased, and in vivo cortical NO levels were reduced (P < 0.05) compared with control animals. Acute administration of the HO inhibitor Stannous mesoporphyrin (SnMP; 40 µmol/kg iv) did not alter renal hemodynamics in control rats, but greatly decreased glomerular filtration rate and renal blood flow, markedly increasing RVR in hyperglycemic diabetic rats. Chronic oral treatment with the SOD mimetic tempol prevented the elevation of nitrotyrosine, the HO-1 protein induction, and the increases in RVR induced by SnMP in the diabetic group, without altering basal NO concentrations or RVR. Increasing concentrations of a CO donor (CO-releasing molecule-A1) on pressurized renal interlobar arteries elicited a comparable relaxation in vessels taken from control or diabetic animals. These results suggest that oxidative stress-induced HO-1 exerts vasodilatory actions that partially maintain renal hemodynamics in uncontrolled DM-1.

Sex differences in nitrosative stress during renal ischemia.

Females suffer a less severe ischemic acute renal failure than males, apparently because of higher nitric oxide (NO) bioavailability and/or lower levels of oxidative stress. Because the renal ischemic injury is associated with outer medullary (OM) endothelial dysfunction, the present study evaluated sex differences in OM changes of NO and peroxynitrite levels (by differential pulse voltammetry and amperometry, respectively) during 45 min of ischemia and 60 min of reperfusion in anesthetized Sprague-Dawley rats. Endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) protein expression and their phosphorylated forms [peNOS(Ser1177) and pnNOS(Ser1417)], 3-nitrotyrosine, reduced sulfhydryl groups (-SH), and glomerular filtration rate (GFR) were also determined. No sex differences were observed in monomeric eNOS and nNOS expression, NO, or 3-nitrotyrosine levels in nonischemic kidneys, but renal -SH content was higher in females. Ischemia increased dimeric/monomeric eNOS and nNOS ratio more in females, but the dimeric phosphorylated peNOS(Ser1177) and pnNOS(Ser1417) forms rose similarly in both sexes, indicating no sex differences in nitric oxide synthase activation. However, NO levels increased more in females than in males (6,406.0 ± 742.5 and 4,058.2 ± 272.35 nmol/l respectively, P < 0.05), together with a lower increase in peroxynitrite current (5.5 ± 0.7 vs. 12.7 ± 1.5 nA, P < 0.05) and 3-nitrotyrosine concentration, (28.7 ± 3.7 vs. 48.7 ± 3.7 nmol/mg protein, P < 0.05) in females than in males and a better preserved GFR after ischemia in females than in males (689.7 ± 135.0 and 221.4 ± 52.5 µl·min(-1)·g kidney wt(-1), P < 0.01). Pretreatment with the antioxidants N-acetyl-L-cysteine or ebselen abolished sex differences in peroxynitrite, nitrotyrosine, and GFR, suggesting that a greater oxidative and nitrosative stress worsens renal damage in males.

Acute effects of 2-methoxyestradiol on endothelial aortic No release in male and ovariectomized female rats.

The endogenous metabolites of 17beta-estradiol are thought to have protective vascular effects, especially in males and estrogen-deprived females. The present study evaluated the acute in vitro effects of the active metabolite 2-methoxyestradiol on endothelial NO release from ovariectomized female and intact male and female rat aortas. NO was measured electrochemically by differential normal pulse amperometry using carbon fiber microsensors, and also by fluorescence microscopy using 4,5-diaminofluorescein diacetate. 2-Methoxyestradiol alone induced a maintained increase in endothelial NO release in male and ovariectomized rats that was reduced by pretreatment with L-NAME. NO release induced by calcium ionophore alone (A23187) was lower in aortas from ovariectomized rats than from intact females, indicating that estrogen deprivation induces endothelial dysfunction. Pretreatment of aortas with 2-methoxyestradiol potentiated significantly the A23187-induced-NO release in ovariectomized as well as in males, but not in intact females. This potentiation was reduced or abolished by L-NAME. 2-Methoxyestradiol potentiated the vasodilatory effect of A23187 on intestinal arterioles, and also increased intestinal tissular laser-Doppler blood flow signal. These results demonstrate that 17beta-estradiol and its active metabolite 2-methoxyestradiol increase basal aortic endothelial NO production and also cause a potentiation of the calcium ionophore-stimulated NO release in male and ovariectomized, while it has no effects on intact females. 2-Methoxyestradiol appears to be a promising pharmacological agent capable of improving endothelial function in men and postmenopausal women.

Transfer of the CYP4A region of chromosome 5 from Lewis to Dahl S rats attenuates renal injury.

This study examined the effect of transfer of overlapping regions of chromosome 5 that includes (4A(+)) or excludes (4A(-)) the cytochrome P-450 4A (CYP4A) genes from the Lewis rat on the renal production of 20-hydroxyeicosatetraenoic acid (20-HETE) and the development of hypertension-induced renal disease in congenic strains of Dahl salt-sensitive (Dahl S) rats. The production of 20-HETE was higher in the outer medulla of 4A(+) than in Dahl S or 4A(-) rats. Mean arterial pressure (MAP) rose to 190 +/- 7 and 185 +/- 3 mmHg in Dahl S and 4A(-) rats fed a high-salt (HS) diet for 21 days but only to 150 +/- 5 mmHg in the 4A(+) strain. Protein excretion increased to 423 +/- 40 and 481 +/- 37 mg/day in Dahl S and 4A(-) rats vs. 125 +/- 15 mg/day in the 4A(+) strain. Baseline glomerular capillary pressure (Pgc) was lower in 4A(+) rats (38 +/- 1 mmHg) than in Dahl S rats (42 +/- 1 mmHg). Pgc increased to 50 +/- 1 mmHg in Dahl S rats fed a HS diet, whereas it remained unaltered in 4A(+) rats (39 +/- 1 mmHg). Baseline glomerular permeability to albumin (P(alb)) was lower in 4A(+) rats (0.19 +/- 0.05) than in Dahl S or 4A(-) rats (0.39 +/- 0.02). P(alb) rose to approximately 0.61 +/- 0.03 in 4A(-) and Dahl S rats fed a HS diet for 7 days, but it remained unaltered in the 4A(+) rats. The expression of transforming growth factor-beta2 was higher in glomeruli of Dahl S rats than in 4A(+) rats fed either a low-salt (LS) or HS diet. Chronic administration of a 20-HETE synthesis inhibitor (HET0016; 10 mg.kg(-1).day(-1) sc) reversed the fall in MAP and renoprotection seen in 4A(+) rats. These results indicate that the introgression of the CYP4A genes from Lewis rats into the Dahl S rats increases the renal formation of 20-HETE and attenuates the development of hypertension and renal disease.

Heme oxygenase-1 induction improves ischemic renal failure: role of nitric oxide and peroxynitrite.

The present study evaluated the effects of heme oxygenase-1 (HO-1) induction on the changes in renal outer medullary nitric oxide (NO) and peroxynitrite levels during 45-min renal ischemia and 30-min reperfusion in anesthetized rats. Glomerular filtration rate (GFR), outer medullary blood flow (OMBF), HO and nitric oxide synthase (NOS) isoform expression, and renal low-molecular-weight thiols (-SH) were also determined. During ischemia significant increases in NO levels and peroxynitrite signal were observed (from 832.1 +/- 129.3 to 2,928.6 +/- 502.0 nM and from 3.8 +/- 0.7 to 9.0 +/- 1.6 nA before and during ischemia, respectively) that dropped to preischemic levels during reperfusion. OMBF and -SH significantly decreased after 30 min of reperfusion. Twenty-four hours later, an acute renal failure was observed (GFR 923.0 +/- 66.0 and 253.6 +/- 55.3 microl.min(-1).g kidney wt(-1) in sham-operated and ischemic kidneys, respectively; P < 0.05). The induction of HO-1 (CoCl(2) 60 mg/kg sc, 24 h before ischemia) decreased basal NO concentration (99.7 +/- 41.0 nM), although endothelial and neuronal NOS expression were slightly increased. CoCl(2) administration also blunted the ischemic increase in NO and peroxynitrite (maximum values of 1,315.6 +/- 445.6 nM and 6.3 +/- 0.5 nA, respectively; P < 0.05), preserving postischemic OMBF and GFR (686.4 +/- 45.2 microl.min(-1).g kidney wt(-1)). These beneficial effects of CoCl(2) on ischemic acute renal failure seem to be due to HO-1 induction, because they were abolished by stannous mesoporphyrin, a HO inhibitor. In conclusion, HO-1 induction has a protective effect on ischemic renal failure that seems to be partially mediated by decreasing the excessive production of NO with the subsequent reduction in peroxynitrite formation observed during ischemia.

N-acetylcysteine exerts protective effects and prevents lung redox imbalance and peroxynitrite generation in endotoxemic rats.

The aim of this study was to determine in endotoxemic rats the effects of N-acetylcysteine on lung redox imbalance and plasma peroxynitrite generation. Eighty male Wistar rats were divided in two sets of five experimental groups. Six hours after vehicle (Control group: isotonic NaCl sterile solution i.p.; n=7), lipopolysaccharide (LPS group: 1 mg/Kg i.p.; n=8), N-acetylcysteine plus LPS (NAC+LPS group, n=8), NAC plus the nitric oxide synthesis inhibitor N(w)-nitro-L-arginine methyl ester plus LPS (NAC+NAME+LPS group; n=8), or NAME plus LPS (NAME+LPS group; n=9), arterial blood and lung samples were taken from each animal under sodium pentobarbital anesthesia. In five additional groups treated as described above, in vivo plasma oxidation of dihydrorhodamine (DRH) 123 to rhodamine (RH)123 was measured as index of peroxynitrite formation. LPS treated rats presented increased plasma lactate, thrombocytopenia and both, decreased reduced thiols and increased lipid peroxidation in lung tissue. Moreover, LPS produced increments in plasma concentration of nitrites/nitrates and DRH 123 oxidation. Pretreatment with NAC prevented all these changes induced by LPS except the increment in plasma concentration of nitrites/nitrates. The protective effects seen in LPS rats pretreated with NAC were not observed in the NAC+NAME+LPS group. In conclusion, the results of this study show that in endotoxemia induced by LPS in rats, NAC produces protective effects on lung redox balance and prevents peroxynitrite anion generation.

Renal ischemia induces an increase in nitric oxide levels from tissue stores.

Tissue nitric oxide (NO) levels increase dramatically during ischemia, an effect that has been shown to be partially independent from NO synthases. Because NO is stored in tissues as S-nitrosothiols and because these compounds could release NO during ischemia, we evaluated the effects of buthionine sulfoximine (BSO; an intracellular glutathione depletor), light stimulation (which releases NO, decomposing S-nitrosothiols), and N-acetyl-L-cysteine (a sulfhydryl group donor that repletes S-nitrosothiols stores) on the changes in outer medullary NO concentration produced during 45 min of renal artery occlusion in anesthetized rats. Renal ischemia increased renal tissue NO concentration (+223%), and this effect was maintained along 45 min of renal arterial blockade. After reperfusion, NO concentration fell below preischemic values and remained stable for the remainder of the experiment. Pretreatment with 10 mg/kg nitro-L-arginine methyl ester (L-NAME) decreased significantly basal NO concentration before ischemia, but it did not modify the rise in NO levels observed during ischemia. In rats pretreated with 4 mmol/kg BSO and L-NAME, ischemia was followed by a transient increase in renal NO concentration that fell to preischemic values 20 min before reperfusion. A similar response was observed when the kidney was illuminated 40 min before the ischemia. The coadministration of 10 mg/kg iv N-acetyl-L-cysteine with BSO + L-NAME restored the increase in NO levels observed during renal ischemia and prevented the depletion of renal thiol groups. These results demonstrate that the increase in renal NO concentration observed during ischemia originates from thiol-dependent tissue stores.

Acute renal hemodynamic effects of dimanganese decacarbonyl and cobalt protoporphyrin.

BACKGROUND: Heme oxygenase (HO) products have a protective role in acute renal failure (ARF) that may be hemodynamically mediated because the HO-derived carbon monoxide (CO) is an important control system of arteriolar tone. The vascular effects of HO may be caused directly through changes in CO synthesis, and indirectly by alterations in nitric oxide (NO) release. The present study evaluated in vivo the renal effects of a heme oxygenase inhibitor, Co(III)Protoporphyrin (CoPP) alone or in combination with the CO donor dimanganese decacarbonyl (Mn2(CO)10). METHODS: All drugs were administered into the renal artery of anesthetized rats. Changes in renal cortical nitric oxide concentration were measured in vivo electrochemically. RESULTS: The intrarenal administration of the CO donor Mn2(CO)10 increased blood carboxyhemoglobin levels (+74%), renal blood flow (+54%), glomerular filtration (+38%), and urinary cGMP excretion (+128%). On the other hand, the inhibition of renal HO with CoPP progressively induced an ARF characterized by a drop in renal blood flow (-77%), glomerular filtration (-93%), and urinary cGMP excretion (-93%). These deleterious effects of HO inhibition on renal function were nearly abolished by supplementing CO with the coadministration of Mn2(CO)10+ CoPP, indicating that they may be caused by inhibition of CO synthesis and the resulting hemodynamic changes. In addition, CoPP lowered the renal cortical NO concentration (-21%) and also decreased the urinary excretion of nitrates/nitrites, while Mn2(CO)10 increased renal NO levels (+20%) and raised the excretion of nitrates/nitrites, suggesting that changes in NO release may contribute to the renal effects of the HO-CO system. CONCLUSION: These results indicate that heme oxygenase-derived CO plays a cardinal role in the control of renal hemodynamics and glomerular filtration.

Role of superoxide in modulating the renal effects of angiotensin II.

Angiotensin II is known to stimulate NADPH oxidase-dependent superoxide (O2-) generation, which may contribute to the acute renal vasoconstrictor and antinatriuretic actions of this peptide. To evaluate this hypothesis, the effects of a superoxide dismutase mimetic (tempol) or a NADPH inhibitor (apocynin) on the angiotensin renal actions were studied. Renal cortical nitric oxide (NO) was measured electrochemically in vivo. Tempol increased sodium excretion and NO levels. Apocynin raised renal blood flow, glomerular filtration rate, sodium excretion, and NO levels. These results indicate the presence of an endogenous NADPH oxidase-dependent O2- generation that may modulate renal function by scavenging NO. Angiotensin II infusion reduced renal blood flow, glomerular filtration, sodium excretion, and NO levels in a dose-dependent manner. The angiotensin receptor antagonist valsartan, tempol, or apocynin blunted the angiotensin effects on renal excretion and NO, suggesting that angiotensin receptors stimulation induces the NADPH oxidase-dependent O2- generation that might reduce NO bioavailability. This idea is supported by the finding that angiotensin increased O2- generation in renal homogenates, and this effect was prevented by valsartan, apocynin, or tempol. These results indicate that some of the acute renal effects of angiotensin II may be enhanced by an increased NADPH oxidase-derived O2- production that reduces renal NO bioavailability.