Effect of cross-tolerance between endotoxin and TNF-alpha or IL-1beta on cellular signaling and mediator production.

Endotoxin [lipopolysaccharide (LPS)] tolerance suppresses macrophage/monocyte proinflammatory-mediator production. This phenomenon also confers cross-tolerance to other stimuli including tumor necrosis factor (TNF) alpha and interleukin (IL)-1beta. Post-receptor convergence of signal transduction pathways might occur after LPS, IL-1beta, and TNF-alpha stimulation. Therefore, it was hypothesized that down-regulation of common signaling molecules induces cross-tolerance among these stimuli. LPS tolerance and cross-tolerance were examined in THP-1 cells. Phosphorylation of MAP kinases and degradation of inhibitor kappaBalpha (IkappaBalpha) DNA binding of nuclear factor-kappaB (NF-kappaB), and mediator production were examined. In naive cells, LPS, TNF-alpha, and IL-1beta induced IkappaBalpha degradation, kinase phosphorylation, and NF-kappaB DNA binding. LPS stimulation induced production of TNF-alpha or TxB2 and degradation of IRAK. However, neither TNF-alpha nor IL-1beta induced IRAK degradation or stimulated TNF-alpha or TxB2 production in naive cells. Pretreatment with each stimulus induced homologous tolerance to restimulation with the same agonist. LPS tolerance also suppressed LPS-induced TxB2 and TNF-alpha production. LPS pretreatment induced cross-tolerance to TNF-alpha or IL-1beta stimulation. Pretreatment with TNF-alpha induced cross-tolerance to LPS-induced signaling events and TxB2 production. Although pretreatment with IL-1beta did not induce cross-tolerance to LPS-induced signaling events, it strongly inhibited LPS TNF-alpha and TxB2 production. These data demonstrate that IL-1beta induces cross-tolerance to LPS-induced mediator production without suppressing LPS-induced signaling to MAP kinases or NF-kappaB activation.

Oxidative stress causes nuclear factor-kappaB activation in acute hypovolemic hemorrhagic shock.

Nuclear Factor kappaB (NFkappaB) is an ubiquitous rapid response transcription factor involved in inflammatory reactions and exerts its action by expressing cytokines, chemokines, and cell adhesion molecules. We investigated the role of NF-kappaB in acute hypovolemic hemorrhagic (Hem) shock. Hem shock was induced in male anesthetized rats by intermittently withdrawing blood from an iliac catheter over a period of 20 min (bleeding period) until mean arterial blood pressure (MAP) fell and stabilized within the range of 20-30 mmHg. Hemorrhagic shocked rats died in 26.3 +/- 2.1 min following the discontinuance of bleeding, experienced a marked hypotension (mean arterial blood pressure = 20-30 mmHg) and had enhanced plasma levels of Tumor Necrosis Factor-alpha (200 +/- 15 pg/ml, 20 min after the end of bleeding). Furthermore, aortas taken 20 min after bleeding from hemorrhagic shocked rats showed a marked hypo-reactivity to phenylephrine (PE; 1nM to 10 microM) compared with aortas harvested from sham shocked rats. Hem shocked rats also had increased levels of TNF-alpha mRNA in the liver (15-20 min after the end of bleeding) and enhanced plasma levels of 2,5-dihydroxybenzoic acid (2,5-DHBA; 6 +/- 2.2 microm), 2,3-dihydroxybenzoic acid (2,3-DHBA; 13 +/- 2.1 microm), both studied to evaluate OH(*) production. Electrophoretic mobility shift assay showed that liver NF-kappaB binding activity increased in the nucleus 10 min after the end of hemorrhage and remained elevated until the death of animals. Western blot analysis suggested that the levels of inhibitory IkappaBalpha protein in the cytoplasm became decreased at 5 min after the end of bleeding. IRFI-042, a vitamin E analogue (20 mg/kg intraperitoneally 2 min after the end of bleeding), inhibited the loss of IkappaBalpha protein from the cytoplasm and blunted the increase in NF-kappaB binding activity. Furthermore IRFI-042 increased survival time (117.8 +/- 6.51 min; p <.01) and survival rate (vehicle = 0% and IRFI-042 = 80%, at 120 min after the end of bleeding), reverted the marked hypotension, decreased liver mRNA for TNF-alpha, reduced plasma TNF-alpha (21 +/- 4.3 pg/ml), and restored to control values the hypo-reactivity to PE. Our results suggest that acute blood loss (50% of the estimated total blood volume over a period of 20 min) causes early activation of NF-kappaB, likely through an increased production of reactive oxygen species. This experiment indicates that NF-kappaB-triggered inflammatory cascade becomes early activated during acute hemorrhage even in the absence of resuscitation procedures.

Signal transduction events in Chinese hamster ovary cells expressing human CD14; effect of endotoxin desensitization.

Previous studies suggest that endotoxin (LPS) stimulation of CD14 receptors may be coupled to heterotrimeric G proteins. However, characterization of the G protein-coupled signaling pathways is incomplete. Also, specific changes in the transduction pathways occur in a phenomenon known as LPS tolerance or desensitization induced by prior exposure to LPS. In the present study, we examined potential CD14-dependent G protein-coupled signaling events in response to LPS, and changes in signaling in these pathways during LPS desensitization in Chinese Hamster Ovary (CHO) cells. LPS stimulated inhibitory kappa B alpha (IkappaB alpha) degradation and p38 phosphorylation in CHO cells transfected with human CD14 receptor (CHO-CD14), but not in CHO cells transfected with vector only. However, activation of these signaling events diverged early in the signal transduction pathways. Pretreatment with pertussis toxin, which inactivates inhibitor G protein (G alpha i) function, significantly inhibited LPS-induced p38 phosphorylation, but not LPS-induced IkappaB alpha degradation. Mastoparan, a putative G alpha i agonist, synergized with LPS to induce p38 phosphorylation. Thus, LPS stimulation of p38 phosphorylation is, in part, G alpha i coupled, whereas IkappaB alpha degradation is not. In subsequent studies, CHO-CD14 cells were desensitized by prior LPS exposure. LPS-desensitized cells exhibited augmented IkappaB alpha content and were refractory to LPS-induced IkappaB alpha degradation and p38 phosphorylation. Pretreatment with cycloheximide, a protein synthesis inhibitor, prevented the effect of LPS desensitization on augmenting cellular IkappaB alpha content and its refractoriness to LPS-induced degradation. However, cycloheximide pretreatment did not prevent impaired p38 phosphorylation in desensitized cells. IkappaB alpha upregulation in LPS tolerance may occur through increased synthesis and/or induction of protein that suppress IkappaB alpha degradation. The latter protein synthesis-dependent mechanisms may be distinct from mechanismis inhibiting p38 phosphorylation in tolerance. These findings suggest that LPS tolerance induces CD14-dependent signaling alterations in G alpha i-coupled pathways leading to mitogen-activated (MAP) kinase activation as well as G alpha i-independent pathways inducing IkappaB alpha degradation.

Usefulness of transesophageal echocardiographic monitoring to improve the outcome of stent-graft treatment of thoracic aortic aneurysms.

The stent-graft procedure is becoming an alternative to surgery for treatment of many diseases of the descending thoracic aorta. This study evaluated the role of transesophageal echocardiography (TEE), used in combination with fluoroscopy and angiography, in monitoring the outcome of stent-graft placement. Twenty-two consecutive patients were submitted to stent-graft positioning in the descending aorta for various pathologies (7 patients had type B aortic dissections, 6 had thoracic aneurysms, 2 had thoraco-abdominal aneurysms, and 7 had post-traumatic aortic aneurysms). Before stent-graft deployment, TEE changed the proximal site of stent positioning initially identified by angiography in 33% of patients (5 of 15) with aortic aneurysms because of calcifications or atheromas that could interfere with stent adhesion to the aortic wall and that were not seen on angiography. In 28% of patients (2 of 7) with aortic dissection, TEE showed the guidewire in the false lumen, allowing an immediate repositioning. After stent-graft deployment, color Doppler TEE showed a perigraft leak in 7 patients, whereas angiography detected a perigraft leak in only 2 patients (p = 0.02). In 4 of these patients, further balloon expansions resulted in resolution of the leak. In the remaining 3 patients, additional stent-graft positioning was necessary. Considering the total patient cohort, TEE yielded relevant information, resulting in procedure changes in 59% (13 of 22). In conclusion, TEE provided additional information with respect to angiography in all phases of stent-graft treatment, improving immediate outcome and reducing complications.

The reduction of myocardial damage and leukocyte polymorphonuclear accumulation following coronary artery occlusion by the tyrosine kinase inhibitor tyrphostin AG 556.

We investigated the effects of tyrophostin AG 556, a tyrosine kinase inhibitor, on the phenomenon of leukocyte accumulation during ischaemia and reperfusion of the myocardium. Male anaesthetized rats were subjected to total occlusion (45 min) of the left main coronary artery followed by 5 h reperfusion (MI/R). Sham myocardial ischaemia-reperfusion rats (Sham MI/R) were used as controls. Myocardial necrosis, myocardial myeloperoxidase activity (MPO), serum creatinine phosphokinase activity (CPK) serum Tumor Necrosis Factor (TNF-alpha) and Interleukin 6 (IL-6), cardiac intercellular adhesion molecule-1 (ICAM-1) and TNF-alpha expression and myocardial contractility (left ventricle dP/dt(max)) were evaluated. Myocardial ischaemia plus reperfusion in untreated rats produced marked myocardial necrosis, increased serum CPK activity (196.5 +/- 19 U/100 ml, at the end of reperfusion) and myeloperoxidase activity (MPO, a marker of leukocyte accumulation) both in the area-at-risk (4.5 +/- 0.5 U/g/tissue) and in necrotic area (8.2 +/- 1.2 U/g/tissue), reduced myocardial contractility (1,706 +/- 52 mmHg/s, at the end of reperfusion) and induced a marked increase in the serum levels of TNF-alpha (1,950 +/- 97 pg/ml, at 1 h of reperfusion) and IL-6 (998 +/- 16 U/ml, at the end of reperfusion). Finally, myocardial ischaemia-reperfusion injury also increased cardiac mRNA for TNF-alpha and ICAM-1 in the myocardium-at risk. Tyrphostin AG 556 (0.5, 1 and 2 mg/kg subcutaneously 5 min after the onset of reperfusion) lowered myocardial necrosis and myeloperoxidase activity in the area-at-risk (1.5 +/- 0.2 U/g/tissue, following the highest dose) and in necrotic area (2.9 +/- 0.3 U/g/tissue following the highest dose), decreased serum CPK activity (96 +/- 9 U/100 ml, at the end of reperfusion), lowered serum TNF-alpha and IL-6, increased myocardial contractility (2,096 +/- 88 mmHg s, at the end of reperfusion) and reduced cardiac mRNA levels for TNF-alpha and ICAM-1. The present data suggest that tyrosine kinase inhibitors protect against myocardial ischaemia-reperfusion injury by reducing leukocyte accumulation to the ischaemic myocardium.

Suppression of Cox-2 and TNF-alpha mRNA in endotoxin tolerance: effect of cycloheximide, antinomycin D, and okadaic acid.

Lipopolysaccharide (LPS)-tolerant human promonocytic THP-1 cells produce decreased levels of inflammatory mediators such as eicosanoids and tumor necrosis factor alpha (TNFalpha) in response to LPS. We hypothesized that transcriptional repression by newly synthesized proteins may be a mechanism for the reduced cellular response to a secondary challenge with LPS. THP-1 cells were desensitized after a 3.5 h or 20 h pre-exposure to LPS (1 microg/mL) and subsequently challenged with LPS (10 microg/mL). In cells rendered tolerant by exposure to LPS for 20 h, LPS-induced expression of cyclooxygenase (Cox)-2 and TNFalpha mRNA was suppressed. Cycloheximide (10 microM) prevented the transcriptional down-regulation of Cox-2 mRNA and to a lesser extent, TNFalpha mRNA, in LPS-tolerant cells. Transcriptional arrest with actinomycin D stabilized steady-state expression of Cox-2 mRNA in naive and tolerant cells but destabilized TNFalpha mRNA expression in LPS-tolerant cells. The observation that in naive cells Cox-2 and TNFalpha mRNA levels subside at 3 to 4 h after LPS (10 microg/mL or 1 microg/mL) suggested that LPS tolerance may occur earlier. Therefore, in subsequent experiments, the effect of LPS pretreatment for only 3.5 h was examined. This abbreviated tolerance regimen diminished secondary LPS-induced Cox-2 mRNA expression but had a lesser effect on TNFalpha mRNA expression. However, cycloheximide augmented both Cox-2 and TNFalpha mRNA expression in this group. Also, the serine/threonine phosphatase inhibitor okadaic acid augmented Cox-2 and TNFalpha mRNA expression in the LPS-tolerant cells. Although LPS-induced TNFalpha production in LPS-tolerant cells was suppressed relative to the naive cells, okadaic acid induced comparable levels of TNFalpha in tolerant and naive cells. These findings support the concept that LPS tolerance is associated with induction of proteins that alter expression of certain genes. Expression of Cox-2 mRNA appears to be particularly sensitive to down-regulation and, to a lesser extent, TNFalpha mRNA. However, this seems to vary depending on the LPS pretreatment regimen. The ability of a phosphatase inhibitor to induce TNFalpha and expression of Cox-2 and TNFalpha mRNA in LPS tolerance suggests that there may be alterations in phosphorylation status of signaling pathways, transcriptional mechanisms, or post-transcriptional mRNA stability.

Protective effects of cyclosporin-A in splanchnic artery occlusion shock.

Cyclosporin A (CsA) is an immunosuppressant drug that inhibits nitric oxide (NO) synthase induction in vascular smooth muscle cells. Splanchnic artery occlusion (SAO) shock is a lethal type of shock characterized by a marked vascular dysfunction in which the L-arginine/nitric oxide pathway plays an important role. We investigated whether CsA exerts protective effects in SAO shock by interfering with the L-arginine/nitric oxide pathway. Male anaesthetized rats (n=156) were subjected to clamping of the splanchnic arteries for 45 min. This surgical procedure resulted in an irreversible state of shock (SAO shock). Sham operated animals were used as controls. SAO shocked rats had a decreased survival (86+/-6 min, while sham shocked rats survived more than 240 min), marked hypotension, increased serum levels of TNF-alpha, enhanced plasma nitrite/nitrate concentrations (75+/-7.1 microM; sham shocked rats=1.6+/-0.5 microM) and enhanced inducible NO synthase (iNOS) protein induction and activity in the aorta. Moreover aortic rings from shocked rats showed a marked hyporeactivity to phenylephrine (PE, 1 nM - 10 microM). CsA (0.25, 0.5 and 1 mg kg(-1), 5 min after reperfusion) increased survival rate (SAO+CsA=236+/-9 min following the highest dose), reverted the marked hypotension, reduced plasma nitrite/nitrate concentration (11+/-5.2 microM following the highest dose), restored to control values the hyporeactivity to PE, and blunted iNOS protein induction and activity in aortic rings. The present data indicate that in an experimental rat model CsA may have antishock properties related to inhibition of L-arginine/nitric oxide pathway.

Genistein supplementation and estrogen replacement therapy improve endothelial dysfunction induced by ovariectomy in rats.

BACKGROUND: We investigated the effect of genistein, a phytoestrogen derived from a soy diet with a flavonoid chemical structure, on endothelial dysfunction induced by estrogen deficiency in rats. METHODS: Female mature Sprague-Dawley rats were subjected to a bilateral ovariectomy (OVX rats). Sham-operated animals (Sham OVX rats) were used as controls. Three weeks after surgery animals were randomized to the following treatments: genistein (0.2 mg/kg/day, s.c. for 4 weeks), 17 beta-estradiol (20 micrograms/kg/day, s.c. for 4 weeks) or their respective vehicles. Mean arterial blood pressure (MAP), heart rate (HR), total plasma cholesterol, plasma estradiol, plasma genistein levels and uterine weights were studied. Furthermore, we investigated acetylcholine (ACh 10 nM-10 microM) and sodium nitroprusside: (SN 15-30 nM) induced relaxation of aortic rings as well as NG-L-arginine (L-NMA: 10-100 microM) induced vasoconstriction in phenylephrine precontracted aortic segments and calcium-dependent nitric oxide synthase (cNOS) activity in homogenates of lungs taken from both sham OVX and OVX rats. RESULTS: Untreated OVX rats had, compared with sham OVX animals, unchanged body weight, MAP, HR and plasma cholesterol. In contrast ovariectomy impaired endothelial responses, blunted L-NMA induced contraction (L-NMA 100 microM: Sham OVX = 2.1 +/- 0.2 g/mg tissue; OVX = 1.7 +/- 0.4 g/mg tissue) and reduced cNOS activity. Treatment with 17 beta-estradiol increased the hormone plasma levels, reverted the endothelial dysfunction and increased cNOS activity in lung homogenates. Genistein supplementation enhanced the circulating levels of the phytoestrogen and affected NOS activity and endothelial dysfunction to the same extent. CONCLUSIONS: Our data suggest that genistein and 17 beta-estradiol show overlapping effects on experimental endothelial dysfunction.

Tacrolimus suppresses tumour necrosis factor-alpha and protects against splanchnic artery occlusion shock.

1. Tumour necrosis factor (TNF-alpha) is a pleiotropic cytokine which is deeply involved in the pathogenesis of splanchnic artery occlusion (SAO) shock. Tacrolimus, formerly known as FK506, is a macrolide antibiotic, that blocks the transcription of several proinflammatory cytokines including TNF-alpha. 2. Male anaesthetized rats were subjected to clamping of the splanchnic arteries for 45 min. This surgical procedure resulted in an irreversible state of shock (SAO shock). Sham operated animals were used as controls. SAO shocked rats had a decreased survival rate (0% at 4 h of reperfusion, while sham shocked rats survived more than 4 h), enhanced serum TNF-alpha concentrations (415+/-12 U ml(-1)), decreased mean arterial blood pressure (MAP), leukopenia and increased ileal leukocyte accumulation studied by means of myeloperoxidase activity (MPO=7.5+/-0.3 U g(-1) tissue). Moreover aortic rings from shocked rats showed a marked hyporeactivity to phenylephrine (PE, 1 nM - 10 microM), reduced responsiveness to acetylcholine (ACh, 10 nM - 10 microM) and increased staining for intercellular adhesion molecule-1 (ICAM-1). Furthermore increased mRNA for TNF-alpha was observed in peritoneal macrophages of SAO shocked rats. 3. Tacrolimus (100 microg kg(-1), 5 min after splanchnic arteries occlusion) increased survival rate (SAO + Tacrolimus = 100% at 4 h of reperfusion), reverted the marked hypotension, reduced serum TNF-alpha (15+/-3 U ml(-1)), ameliorated leukopenia, reduced ileal MPO (0.9+/-0.01 U g(-1) tissue), restored to control values the hyporeactivity to PE. improved the reduced responsiveness to ACh and blunted the enhanced immunostaining for ICAM-1 in the aorta. Finally tacrolimus suppressed cytokine mRNA levels in peritoneal macrophages. 4. The data suggest that tacrolimus may represent a new therapeutic approach in circulatory shock.

Cyclosporin-A reduces leukocyte accumulation and protects against myocardial ischaemia reperfusion injury in rats.

The present study was designed to evaluate the effect of cyclosporin A in a rat model of myocardial ischaemia reperfusion injury (MI/R). Anaesthetized rats were subjected to total occlusion (20 min) of the left main coronary artery followed by 5 h reperfusion (MI/R). Sham myocardial ischaemia-reperfusion rats (Sham MI/R) were used as controls. Myocardial necrosis, myocardial myeloperoxidase activity (MPO), serum creatinine phosphokinase activity (CPK), serum tumor necrosis factor (TNF-alpha), cardiac mRNA for TNF-alpha, cardiac intercellular adhesion molecule-1 (ICAM-1) immunostaining and myocardial contractility (left ventricle dP/dtmax) were evaluated. Myocardial ischaemia plus reperfusion in untreated rats produced marked myocardial necrosis, increased serum CPK activity and myeloperoxidase activity (a marker of leukocyte accumulation) both in the area-at-risk and in the necrotic area, reduced myocardial contractility and induced a marked increase in the serum levels of the TNF-alpha. Furthermore increased cardiac mRNA for TNF-alpha was measurable within 10 to 20 min of left main coronary artery occlusion in the area-at-risk and increased levels were generally sustained for 0.5 h. Finally, myocardial ischaemia-reperfusion injury increased ICAM-1 staining in the myocardium. Administration of cyclosporin A (0.25, 0.5 and 1 mg/kg as an i.v. infusion 5 min after coronary artery occlusion) lowered myocardial necrosis and myeloperoxidase activity in the area-at-risk and in the necrotic area, decreased serum CPK activity, increased myocardial contractility, reduced serum levels of TNF-alpha and the cardiac cytokine mRNA levels, and blunted ICAM-1 immunostaining in the injured myocardium. The data suggest that cyclosporin A suppresses leukocyte accumulation and protects against myocardial ischaemia-reperfusion injury.

Sulfatide reduces leucocyte accumulation and reverts vascular failure in splanchnic artery occlusion shock.

Selectin-mediated leucocyte accumulation is implicated in the pathogenesis of splanchnic artery occlusion. Sulfatide is recognized by P-selectin and blocks this adhesion molecule. We investigated the effects of sulfatide in rats subjected to splanchnic artery occlusion shock. Anaesthetized rats, subjected to total occlusion of the superior mesenteric artery and the coeliac trunk for 45 min developed severe shock resulting in death within 85-90 min after the release of occlusion. Sham operated animals were used as controls. Splanchnic artery occlusion shocked rats had marked hypotension, enhanced levels of tumor necrosis factor-alpha (TNF-alpha) in serum and macrophages, leucopenia and increased ileal leucocyte accumulation, studied by the means of myeloperoxidase activity. Furthermore, aortae from shocked rats showed marked hyporeactivity to phenylephrine (1 nM-10 microM), reduced responsiveness to acetylcholine (10 nM-10 microM) and an increased staining for P-selectin in the vasculature. In vivo administration of sulfatide (10 mg/kg, i.v., 5 min after occlusion of the splanchnic arteries) increased survival rate (90%, 4 h after splanchnic artery occlusion shock), enhanced mean arterial blood pressure, reduced serum TNF-alpha (37 +/- 11 U/ml vs. 398 +/- 18 U/ml), ameliorated leucopenia and reduced ileal myeloproxidase activity (1.2 +/- 0.4 U/g tissue vs. 8.2 +/- 0.8 U/g tissue). Aortae from splanchnic artery occlusion shocked rats treated with sulfatide exhibited a greater contractile response to phenylephrine and improved responsiveness to acetylcholine. Moreover sulfatide-treated rats showed a reduced staining for P-selectin in the aorta and in the superior mesenteric artery. Finally, passive immunization with specific monoclonal antibodies raised against P-selectin significantly protected from the lethality induced by splanchnic artery occlusion shock. Our results suggest that sulfatide protects against splanchnic artery occlusion shock.

Beneficial effect of raxofelast, an hydrophilic vitamin E analogue, in the rat heart after ischemia and reperfusion injury.

Several studies report that among the antioxidant agents used to reduce injury after myocardial ischemia/reperfusion, analogues of vitamin E (VE) seem to have a significant efficacy. Raxofelast is a potent antioxidant agent under investigation, structurally related to VE, having an excellent bioavailability and favourable physicochemical properties. We assessed raxofelast in a rat model of myocardial damage induced by 1 h of left coronary artery occlusion followed by 6 h of reperfusion. Myocardial ischemia/reperfusion produced: wide tissue necrosis (50.3+/-10.3%); membrane peroxidation, evaluated by assessing cardiac malondialdehyde (MAL) (87.8+/-15.8 nmol/g tissuev 9.53+/-2.4 nmol/g tissue) and plasma conjugated dienes (CD) (8.73+/-1.86 DeltaABS/mlv 1.61+/-0.45 DeltaABS/ml); endogenous antioxidant wasting [cardiac VE=23.5+/-10.2 nmol/g tissuev 61.4+/-13.4 nmol/g tissue, cardiac reduced glutatione (GSH)=2.15+/-1.23 micromol/g proteinv 7.34+/-0.92 micromol/g protein and cardiac superoxide dismutase (SOD)=8.9+/-4.1 U/mg proteinv 17. 5+/-4.2 U/mg protein]; depressed mean arterial blood pressure (MAP) (61.4+/-5.8 mmHgv 85.3+/-6.2 mmHg); heart rate (HR) (275+/-35 beats/minv 368+/-34 beats/min) and left-ventricular derivative developed force (LV dP/dtmax) (1050+/-187 mmHg/sv 2520+/-194 mmHg/s); and cardiac neutrophil accumulation, evaluated by assessing cardiac myeloperoxidase (MPO) (9.23+/-2.1 U/g tissuev 0.92+/-0.12 U/g tissue). Administration of raxofelast (25, 50 and 100 mg/kg i.p. 5 min after occlusion) limited myocardial necrosis (22.3+/-14.8%P<0. 005, following the highest dose), reduced lipid peroxidation (MAL=43. 5+/-14.7 nmol/g tissueP<0.001 and CD=4.01+/-2.21 DeltaABS/mlP<0.001, following the highest dose), restored the endogenous antioxidants VE (52.8+/-14.2 nmol/g tissueP<0.001, following the highest dose), SOD (14.2+/-2.7 U/mg proteinP<0.001, following the highest dose) and GSH (4.92+/-1.33 micromol/g proteinP<0.005, following the highest dose), improved hemodynamic parameters (MAP=68.1+/-5.3 mmHgP<0.05, HR=317+/-27 beats/minP<0.05, LV dP/dtmax=1427+/-143 mmHg/sP<0.05, following the highest dose) and reduced myocardial neutrophil infiltration (MPO=5.1+/-1.5 U/g tissueP<0.001, following the highest dose). These data suggest that raxofelast could be considered a useful drug to reduce myocardial infarction.

[The surgical treatment of a rare primary cardiac tumor: hemangioma. A report of 2 cases]. / Trattamento chirurgico di un raro tumore primitivo cardiaco: l'emangioma. Osservazione di due casi.

Primary benign tumors of the heart are particularly rare; cardiac hemangioma is one of the most rare primary benign cardiac tumors. Natural history, symptoms and prognosis of the disease depend on the potential complications due to the location and diffusion of the mass. We report on 2 cases of cardiac hemangioma, diagnosed occasionally in the first patient or due to gastroenteric symptoms in the second patient. The diagnosis was obtained by 2-D-echo and magnetic resonance imaging. In both cases the hemangioma was located on the right ventricle. Both patients underwent tumor resection in hypothermic cardiopulmonary bypass. In one case, a graft to the right coronary artery was associated; in the other case, the right ventricular outflow tract was reconstructed with an infundibular patch. Histology showed mixed hemangioma in one case and cavernous hemangioma in the other. The postoperative course was uneventful. At a follow-up of 8 years and 1 year, respectively, both patients are classified as NYHA 1 and both 2-D-echo and magnetic resonance imaging did not show any residual tumoral mass. This experience demonstrates that, depending on their location, benign neoplastic masses may be radically resected with acceptable operatory risks and excellent long-term results.

[Percutaneous aortic valvuloplasty in the adult. When and why is now useful?]. / La valvuloplastica aortica percutanea nell'adulto. Quando e per chi è ancora utile?.

Percutaneous aortic valvuloplasty was introduced into clinical practice in 1986 and widely applied in elderly patients with symptomatic aortic stenosis. Nevertheless its results have been unsatisfactory over the mid to long term due to a high incidence of restenosis after 6-12 months. At the same time, patients over 70 years are more frequently undergoing surgical aortic valve replacement with low immediate postoperative mortality and good long term results. Although randomized trials are not available, aortic valve replacement seems to be a definitive therapeutic treatment when compared to the palliative result of aortic percutaneous valvuloplasty. However, since the complication rate of valvuloplasty carried out in cardiological centers with experienced personnel is low, this procedure is still indicated in selected patients. The very old (> 80 years) patients with associated systemic disease, and candidates for major surgery are referred for this procedure. Another indication for aortic valvuloplasty is severe aortic stenosis with cardiogenic shock; in this case, valve dilatation improves clinical status and acts as a "bridge" to surgery, enabling surgical intervention to be carried out at a later date. Nowadays, aortic percutaneous valvuloplasty is a possible alternative to surgical treatment in patients with an absolute surgical contraindication and in those who are in such poor clinical condition that they cannot be immediately referred to surgery. It is also useful for patients requiring urgent non-cardiac surgery (e.g., subjects with gastrointestinal bleeding). We discuss our results with this procedure which concord with those presented in the literature.

[Brucella endocarditis: role of drug treatment associated with surgery]. / Endocardite da brucella: ruolo del trattamento medico associato a quello chirurgico.

Brucella infective endocarditis is an uncommon, but serious complication of brucellosis. The aortic valve is the most commonly affected cardiac valve, and a fearful complication is the formation of aortic root abscess. Due to the characteristics of the infection, medical therapy alone is not sufficient in treating the disease and best results are achieved in combination with surgery. We describe 2 cases of brucella endocarditis involving the aortic valve. Aggressive treatment, with surgery performed during a period of active infection, produced good results in eradication of infection and in preventing fatal complications such as rupture of aortic root abscesses.

Participation of tumour necrosis factor and nitric oxide in the mediation of vascular dysfunction in splanchnic artery occlusion shock.

1. Splanchnic artery occlusion (SAO) shock is characterized by irreversible circulatory failure. Tumour necrosis factor (TNF-alpha) may affect the L-arginine/nitric oxide (NO) pathway, thus contributing to the cardiovascular derangements of circulatory shock. 2. We investigated the contribution of both TNF-alpha and the L-arginine/nitric oxide pathway to the vascular dysfunction of SAO shock. Anaesthetized rats, subjected to total occlusion of the superior mesenteric artery and the coeliac trunk for 45 min developed a severe shock state (SAO shock) resulting in a fatal outcome within 75-90 min after the release of occlusion. Sham operated animals were used as controls. SAO shocked rats had also a marked hypotension and enhanced macrophage and serum levels of TNF-alpha. Furthermore, aortic rings from shocked rats showed a marked hyporeactivity to phenylephrine (PE 1 nM-10 microM) and reduced responsiveness to acetylcholine (ACh 10 nM-10 microM). Endothelium-denuded aortic rings had also a marked hyporeactivity to phenylephrine, which was restored to control values by in vitro administration of NG nitro-L-arginine-methyl ester (L-NAME 10 microM). 3. In vivo administration of cloricromene (2 mg kg-1, i.v.), an inhibitor of TNF-alpha biosynthesis, increased survival, enhanced mean arterial blood pressure and reduced macrophage and serum levels of TNF-alpha. Furthermore, aortic rings from shocked rats treated with cloricromene exhibited a greater contractile response to phenylephrine and improved responsiveness to ACh when compared to aortic rings from vehicle-treated SAO shocked rats. 4. Our results suggest that TNF-alpha alters both endothelial and muscular L-arginine/nitric oxide pathways which in turn produce vascular dysfunction in SAO shock.

[Restrictive cardiomyopathies]. / Le cardiomiopatie restrittive.

The restrictive cardiomyopathies are the least common of the 3 major categories of cardiomyopathic disorders seen in Western countries. According to the report of the WHO/ISFC Task Force the term restrictive cardiomyopathy applies to only 2 conditions: endomyocardial fibrosis and Loeffler endocarditis while many specific myocardial diseases can develop a restrictive pathophysiologic profile along their natural history. During the last decade this topic has received 2 main contributions: the identification of a common pathophysiologic ground linking Loeffler endocarditis and endomyocardial fibrosis and the identification of the so-called idiopathic restrictive cardiomyopathy. This condition, defined as a myocardial disease with restrictive physiology, unknown etiology and without histological evidence of infiltrative or storage diseases, appears to be the single most frequent type of restrictive cardiomyopathy in Western countries. A revision of the current classification of cardiomyopathies and particularly of restrictive myocardial disease is necessary.

[Role of transesophageal echography in the diagnosis of aortic dissection and in therapy programming]. / Ruolo dell'ecografia transesofagea nella diagnosi di dissezione aortica e nella programmazione della terapia.

The diagnostic accuracy of transesophageal echocardiography and its relevance on the decision making process were evaluated in 80 patients with suspected aortic dissection during a 37-month period. The diagnosis was proven by aortography and/or magnetic resonance and/or computerized tomography and/or surgery and/or autopsy in each case. Transesophageal echocardiography had no serious complication. A correct diagnosis of aortic dissection was made in 39 of 40 patients (sensitivity, 97.5%; specificity, 100%) and the type of dissection was correctly demonstrated in each case. Thrombi in the false lumen were detected in 16 patients. The primary entry site was correctly identified in 33 patients (85%). Aortic regurgitation was detected in 25 cases (severe in 9) and pericardial effusion in 14 (with tamponade in 2). Transesophageal echocardiography was more accurate than aortography in the diagnosis of noncommunicating intramural dissection (2 cases) and identified more precisely the retrograde extension of the dissection in DeBakey type III patients (4 cases). In 9 cases surgical indication was based on clinical data and transesophageal echocardiography alone. We conclude that transesophageal echocardiography allows a bedside, safe and accurate diagnosis of aortic dissection. In the majority of the patients it provides the minimal diagnostic information necessary to the therapeutical decision making.