POS0225 RISK OF MAJOR CARDIOVASCULAR EVENT ACROSS JAK INHIBITOR TREATED PATIENTS: ANALYSIS OF A NATIONAL CLAIM DATABASE

Background:

Inhibiting a specific JAK may impede more than one pathway, explaining both the efficacy and adverse effects observed with JAK inhibitors (JAKi). Among those, there have been recent concerns about potential thromboembolic risks with these drugs. As patients enrolled are not representative of all patients who may receive JAKi, data from trials are unlikely to provide definitive answers. Real impact of JAKi in real life on major cardiovascular events is not known.

Objectives:

To evaluate the risk of venous and arterial thromboembolic events with the use of JAKi in a real-world setting.

Methods:

A self-controlled case series analysis (method in which individuals act as their own control) was performed using data from the French national healthcare insurance system SNDS (“Système National des Données de Santé”), which included all anonymized individual level data about sociodemographic data, outpatient healthcare dispensed, hospital discharge summaries, and registration status for a list of 30 long term diseases. All patients treated by JAKi (baricitinib or tofacitinib) for rheumatoid arthritis, psoriasis arthritis and/or inflammatory bowel disease, and with at least one thromboembolic event (venous (VTE): deep vein thrombosis (DVT), pulmonary embolism (PE), arterial (ATE): acute coronary syndrome (ACS), myocardial infarction (MI), transient ischemic attack (TIA) and stroke) between 2017/11/01 and 2019/06/30 were included in the study. Associations were evaluated by incidence rate ratios (IRR), which compare the rate of events during exposed periods with rate of event during all other observed time periods. Exposed periods were defined as i) exposure to JAKi, ii) the month following exposure (post-exposure 1-30 days), and iii) long-term post-exposure (31 to 60 days). A pre-exposure period of 7 days was individualized to identify event-dependent probabilities of exposure and potential reverse causality bias, and all other periods were considered as non-exposed periods.

Results:

Among the 5,870 patients treated with JAKi between 2017/11/01 and 2019/06/30, 94 presented an incident thromboembolic event and were included. Almost two thirds were female (n=61, 64.9%), and median age was 65.4 [IQR: 55.5; 75.8] years. Most of patients have a rheumatoid arthritis (n=91, 96.8%), 62 (66.0%) were treated by baricitinib, and 32 (34.0%) by tofacitinib. Almost half (n=42, 44.7%) presented a venous thromboembolism, mainly DVT (n=31, 33.0%), and 52 (55.3%) presented an arterial thromboembolism, mainly MI (n=16, 17.0%) and stroke (n=14, 14.9%). Eleven patients (11.7%) died during the study period. The median time of occurrence of VTE was 4.3 [IQR: 2.5; 8.9] months, and 6.1 [IQR: 3.3; 9.2] months for ATE.

The median duration of exposure was 6.0 [IQR: 3.3; 10.1] months for VTE, and 12.0 [IQR: 4.8; 15.3] months for ATE. The IRR for VTE and ATE were increased during exposure, and during the 30 days following exposure (Table 1). The IRR for VTE was only increased during exposure and in the early post-exposure phase contrary to the IRR for ATE that was also increased in the pre-exposure 7-Day period. Analysis conducted on survival patients confirmed results.

Table 1.NPatient-yearsIRR95%CIVenous thromboembolic eventsNon-exposure (reference)83975.01-Pre-exposure to JAK-i1135.24.70.6-38.0Exposure to JAK-i272090.59.84.1-23.3Post-exposure 1-30 d5369.06.21.9-19.9Post-exposure 31-60 d1139.01.50.2-12.6Arterial thromboembolic eventsNon-exposure (reference)74076.81-Pre-exposure to JAK-i3344.111.52.8-46.8Exposure to JAK-i326363.87.42.9-18.7Post-exposure 1-30 d8659.211.53.8-34.6Post-exposure 31-60 d2132.24.30.8-22.0

Conclusion:

The present study found an increased risk of VTE and ATE for baricitinib and tofacitinib. The risk persists in the month following the discontinuation of treatment but disappears after day 30 post-exposure.

Disclosure of Interests:

Amandine Gouverneur: None declared, Jérôme Avouac Consultant of: JA has/had consultancy relationship and/or has received research funding in the area of potential treatments for rheumatoid arthritis from (last three years): Abbvie, Galapagos, Pfizer, Bristol Myers Squibb, Sanofi, Nordic Pharma, Chugai and MSD., Grant/research support from: JA has/had consultancy relationship and/or has received research funding in the area of potential treatments for rheumatoid arthritis from (last three years): Abbvie, Galapagos, Pfizer, Bristol Myers Squibb, Sanofi, Nordic Pharma, Chugai and MSD., Clément Prati: None declared, Jean-Luc Cracowski: None declared, Thierry Schaeverbeke Consultant of: TS consultancy and/or research fundings: Abbvie, Lilly, Pfizer, Galapagos, Novartis, BMS, Medac, NordicPharma, Biogen, Mylan, Janssen., Grant/research support from: TS consultancy and/or research fundings: Abbvie, Lilly, Pfizer, Galapagos, Novartis, BMS, Medac, NordicPharma, Biogen, Mylan, Janssen., Antoine Pariente Grant/research support from: AP reports acting as an independant expert towards the French Medicines Agency (Agence Nationale de Securité du Médicament et des Produits de Santé, ANSM) and the European Medicines Agency (EMA). AP coordinates the DRUGS Systematised Assessment in real-liFe EnviRonment (DRUGS-SAFER) programme funded by the Agence Nationale de Sécurité du Médicament et des Produits de Santé (ANSM)., Marie-Elise Truchetet Consultant of: has/had consultancy relationship and/or has received research funding in the area of potential treatments for rheumatoid arthritis and spondyloarthritis and their complications from (last three years): Abbvie, Galapagos, Lilly, Medac, Novartis, Pfizer, and Roche., Grant/research support from: has/had consultancy relationship and/or has received research funding in the area of potential treatments for rheumatoid arthritis and spondyloarthritis and their complications from (last three years): Abbvie, Galapagos, Lilly, Medac, Novartis, Pfizer, and Roche.

FRI0590 BIOMARKERS OF HEMODYNAMIC SEVERITY OF SYSTEMIC-SCLEROSIS ASSOCIATED PULMONARY ARTERIAL HYPERTENSION BY SERUM PROTEOME ANALYSIS

Objectives:

To investigate alterations in the serum proteome of patients with systemic sclerosis (SSc)-associated pulmonary hypertension (PAH), to identify proteins that correlated with hemodynamic severity and to determine their possible pathogenic role.

Methods:

Patients were included if they fulfilled the following criteria: diagnosis of limited cutaneous SSc, no extensive interstitial lung disease (ILD), and no treatment with PAH-specific therapy. Patients were classified as cases if they had a definitive diagnosis of PAH confirmed by right heart catheterization (RHC) and a serum sample collected on the same day as RHC. They were classified as controls if they had no sign suggestive of PAH on echocardiography.

Results:

In a first exploratory step, serum expression of 1129 proteins was assessed in 15 cases and 16 controls by a high-throughput proteomic assay (SOMAscan). We identified 53 proteins differentially expressed between the 2 groups. Among these 53 candidates, only 2 correlated significantly with pulmonary vascular resistance (PVR): chemerin (p=0.01,ρ=0.62) and SET nuclear proto-oncogen (SET) (p=0.01,ρ=0.62).

To validate these results, serum levels of chemerin and SET were measured by ELISA assay in 25 additional cases and 19 additional controls. Chemerin levels were confirmed to be significantly higher in cases (p=0.01) and correlated with PVR (p=0.01,ρ=0.46).

In a second step, to study the potential pathophysiological role of chemerin, we performed confocal immunofluorescence analyses on explanted lungs of healthy controls, SSc-ILD without PAH and SSc-PAH patients. Chemerin receptor, CMKLR1, was significantly increased on SSc-ILD and SSc-PAH pulmonary artery smooth muscle cells (PA-SMC).

We then tested the effect of chemerin on PA-SMC proliferation by stimulating PA-SMCs from idiopathic pulmonary arterial hypertension (iPAH) patients with serum from SSc patients with and without PH, in the presence or absence of a CMKLR1 inhibitor. PA-SMCs from iPAH were confirmed to have higher mRNA expression of CMKLR1 than controls (p=0.03). Serum from SSc-PH patients induced a significantly higher PA-SMC proliferation (p=0.005) than serum from controls. This difference was no longer significant (p=0.69) when adding the CMKLR1 inhibitor α–NETA.

Conclusion:

Chemerin is a surrogate biomarker for PVR in SSc-PAH. Increased chemerin and its receptor, CMKLR1, contribute to the SSc-PAH pathogenesis by inducing PA-SMC proliferation.

Acknowledgments:

None

Disclosure of Interests:

Sebastien SANGES: None declared, Lisa Rice: None declared, Ly Tu: None declared, Jean-Luc Cracowski Grant/research support from: JL Cracowski received grants from United Therapeutic, Bioprojet and Topadur, David Montani Grant/research support from: Dr. MONTANI reports grants and personal fees from Actelion, grants and personal fees from Bayer, personal fees from GSK, personal fees from Pfizer, personal fees from MSD, personal fees from Chiesi, outside the submitted work, Julio Mantero: None declared, Camille Ternynck: None declared, Guillemette Marot: None declared, Eric Hachlla: None declared, David Launay Grant/research support from: Dr. Launay reports personal fees from Actelion, grants and personal fees from Takeda, grants and personal fees from CSL Behring, outside the submitted work., Marc Humbert Grant/research support from: Dr. Humbert reports personal fees from Actelion, grants and personal fees from Bayer, grants and personal fees from GSK, personal fees from Merck, from United Therapeutics, personal fees from Acceleron, outside the submitted work., Christophe Guignabert: None declared, Robert Lafyatis Grant/research support from: RL holds research grants from Formation, Elpidera and Kiniksa., Consultant of: R.L. has served as a consultant for Bristol Myers Squibb, Boehringer-Mannheim, Merck, Magenta and Genentech/Roche,

Learning condyle repositioning during orthognathic surgery with a surgical navigation system

Condyle repositioning during bilateral sagittal splint osteotomy (BSSO) is a challenging step for the inexperienced surgeon. We aimed to demonstrate the benefit of navigation for learning the condyle repositioning. We treated 100 patients who underwent a BSSO. A trainee performed the condyle repositioning of one side in two phases. In the first one, the trainee positioned without watching the screen of the Orthopilot Navigation system (ONS). In the second one, the trainee could use the ONS to replace the condyle. Heuristic, anatomical and functional scores of each phase were recorded. Heuristic (17% vs. 75%; p<0.0001), anatomical (35% vs. 86%; p<0.0001) and functional (14% vs. 56%; p<0.0001) scores were significantly greater with the ONS. The ONS is a promising and original intraoperative learning tool for the repositioning of the condyle during BSSO.

Abnormal amplitude and kinetics of digital postocclusive reactive hyperemia in systemic sclerosis

OBJECTIVES

Postocclusive reactive hyperemia is mediated by two major mediators: sensory nerves and endothelium-derived hyperpolarizing factors. We hypothesized that the skin microvascular response to 5 min ischemia would differ depending upon the hand location in patients with systemic sclerosis (SSc), primary Raynaud's phenomenon (PRP) and healthy controls.

METHODS

Fifteen patients with SSc, 15 sex- and age-matched patients with PRP and healthy controls were enrolled. Their right hands were subjected to 5 min ischemia followed by a postocclusive hyperemia test, with local microcirculation monitoring by laser speckle contrast imaging on the dorsal face of the hand.

RESULTS

Postocclusive reactive hyperemia was abnormal in terms of peak and area under the curve (AUC) on all fingers except the thumb in patients with SSc and PRP compared with controls. In contrast, the kinetics of the response was longer only in SSc patients, with mean (SD) time to peak on the index, middle and ring finger were respectively 72 (58), 73 (51) and 67 (47) s for SSc; 40 (20), 40 (20) and 36 (19) s for PRP; and 34 (30), 34 (30) and 29 (24) s for controls (P=0.009 for interaction).

CONCLUSIONS

We observed decreased distal digital microvascular perfusion following 5 min of ischemia in patients presenting with PRP or SSc, while the kinetics was prolonged only in SSc. A dynamic assessment of digital skin blood flow using laser speckle contrast imaging following 5 min ischemia could be used as a tool to assess microvascular abnormalities in patients with Raynaud's phenomenon secondary to SSc.

Skin microdialysis coupled with laser speckle contrast imaging to assess microvascular reactivity

OBJECTIVE

Laser speckle contrast imaging (LSCI) can be used to assess real-time responses of skin microcirculation to pharmacological interventions. The main objective of this study was to determine whether intradermal or subdermal microdialysis fiber insertion, coupled with skin flux recording using LSCI, can be used to assess baseline cutaneous flux and the post-occlusive reactive hyperemic response. The microdialysis sites were compared to control area without microdialysis fibers.

METHODS

One dermal and two subdermal microdialysis fibers were randomly inserted in the right forearm skin of six healthy volunteers. We performed consecutively tests of post-occlusive hyperemia, infusion of 29 mM sodium nitroprusside (SNP), local thermal hyperemia at 43°C and a second 29 mM SNP infusion at the end of the experiment.

RESULTS

Two hours after fiber insertion, cutaneous vascular conductances (CVC) at the subdermal fiber sites were not different from their respective control regions of interest, while at the dermal site CVC remained higher (0.48+/-0.15 versus 0.37+/-0.1 PU.mm Hg(-1), P=0.003). The peak CVC and area under the curve observed during post-occlusive reactive hyperemia were similar at all fiber sites and their respective controls. We observed a similar increase in CVC using 29 mM SNP infusion, 40 min local heating at 43°C, and their combination. Finally, physiological and pharmacological responses of the subdermal sites were reproducible in terms of amplitude, whether expressed as raw CVC or as % CVCmax.

CONCLUSIONS

We showed that studying skin microvascular physiological or pharmacological responses using inserted subdermal microdialysis fibers coupled with LSCI is feasible and reproducible, and provides two-dimensional information. This technique will be useful for future mechanistic studies of skin microcirculation.

Cathodal iontophoresis of treprostinil and iloprost induces a sustained increase in cutaneous flux in rats

BACKGROUND AND PURPOSE

The treatment of scleroderma-related digital ulcers is still a therapeutic challenge. The most effective drugs are prostacyclin analogues. However, their usage is limited to an intravenous route of administration and by their frequent side effects. The objective of this study was to test whether treprostinil, iloprost and epoprostenol can induce sustained vasodilatation in rats when delivered locally using cutaneous iontophoresis.

EXPERIMENTAL APPROACH

Treprostinil, iloprost and epoprostenol were delivered by cathodal and anodal iontophoresis onto the hindquarters of anaesthesized rats (n= 8 for each group). Skin blood flow was quantified using laser Doppler imaging and cutaneous tolerance was assessed from day 0 to day 3.

KEY RESULTS

Cathodal but not anodal iontophoresis of treprostinil (6.4 mM), iloprost (0.2 mM) and epoprostenol (1.4 mM) induced a significant and sustained increase in cutaneous blood flow. The effects of treprostinil and iloprost were significantly different from those of treprostinil vehicle. Only weak effects were observed when both drugs were applied locally without current. Skin resistance was unchanged in areas treated with prostacyclin analogues. Finally, skin tolerance was good, with no evidence of epidermal damage.

CONCLUSIONS AND IMPLICATIONS

Cathodal iontophoresis of treprostinil and iloprost increases cutaneous blood flow with a good local tolerance. The effects of cathodal iontophoresis of these drugs should be investigated in humans, as they could have potential as new local therapies for digital ulcers in patients with scleroderma.

NLRP1 influences the systemic sclerosis phenotype: a new clue for the contribution of innate immunity in systemic sclerosis-related fibrosing alveolitis pathogenesis

BACKGROUND

Recent evidence has highlighted a potential role of interleukin 1β (IL-1β) in systemic sclerosis (SSc). NLRP1 provides a scaffold for the assembly of the inflammasome that promotes the processing and maturation of pro-IL-1β. In addition, NLRP1 variants were found to confer susceptibility to autoimmune disorders.

OBJECTIVE

/st> To study a possible association of the NLRP1 rs6502867, rs2670660 and rs8182352, rs12150220 and rs4790797 with SSc in the European Caucasian population.

METHODS

NLRP1 single nucleotide polymorphisms were genotyped in 3227 individuals comprising a discovery set (870 SSc patients and 962 controls) and a replication set including individuals from Germany (532 SSc patients and 324 controls) and Italy (527 SSc patients and 301 controls), all individuals being of European Caucasian origin.

RESULTS

Conditional analyses revealed a significant association for the NLRP1 rs8182352 variant with both anti-topoisomerase-positive and SSc-related fibrosing alveolitis (FA) subsets under an additive model: p=0.0042, OR 1.23 (95% CI 1.07 to 1.41) and p=0.0065 OR 1.19 (95% CI 1.05 to 1.36), respectively. Logistic regression analysis showed an additive effect of IRF5 rs2004640, STAT4 rs7574865 and NLRP1 rs8182352 risk alleles on SSc-related FA.

CONCLUSIONS

Our results establish NLRP1 as a new genetic susceptibility factor for SSc-related pulmonary fibrosis and anti-topoisomerase-positive SSc phenotypes. This provides new insights into the pathogenesis of SSc, underlining the potential role of innate immunity in particular in the FA-positive SSc subphenotype, which represents a severe subset of the disease.

Oral sildenafil increases skin hyperaemia induced by iontophoresis of sodium nitroprusside in healthy volunteers

BACKGROUND AND PURPOSE

Sildenafil, a specific inhibitor of phosphodiesterase 5A (PDE5A), is currently tested as a treatment for severe Raynaud's phenomenon. Here, we tested whether sildenafil, alone or combined with local sodium nitroprusside (SNP) delivered through skin iontophoresis, increased forearm cutaneous blood conductance in healthy volunteers, and to assess how well this combination was tolerated.

EXPERIMENTAL APPROACH

Ten healthy volunteers were enrolled. Variations in cutaneous vascular conductance (CVC) following oral administration of 50 or 100 mg of sildenafil with or without SNP iontophoresis were expressed as a percentage of maximal CVC, and were monitored using laser Doppler imaging. SNP iontophoresis was performed on the ventral surface of the forearm, 1 h after application of lidocaine/prilocaine cream.

KEY RESULTS

Sildenafil at 100 mg, but not 50 mg, increased overall responses (area under the curve) (44%) and peak responses (29%) to SNP iontophoresis. Sildenafil at 100 mg, but not 50 mg, increased baseline CVC (75%). Incidence of headache was not changed when SNP iontophoresis was combined with sildenafil. One episode of symptomatic arterial hypotension occurred in a volunteer given 50 mg sildenafil, 30 min after the beginning of SNP iontophoresis.

CONCLUSIONS AND IMPLICATIONS

Oral sildenafil at 100 mg potentiated local skin hyperaemia induced by SNP iontophoresis, with no increased incidence of headaches. The combination of oral specific PDE5A inhibitor and nitrates administered through skin iontophoresis deserves further investigation in diseases such as severe Raynaud's phenomenon, with particular attention to the incidence of arterial hypotension.

Association of the TNFAIP3 rs5029939 variant with systemic sclerosis in the European Caucasian population

BACKGROUND

TNFAIP3 encodes the ubiquitin-modifying enzyme, a key regulator of inflammatory signalling pathways. Convincing associations between TNFAIP3 variants and autoimmune diseases have been reported.

OBJECTIVE

To investigate the association of TNFAIP3 polymorphisms with systemic sclerosis (SSc).

METHODS

Three single nucleotide polymorphisms (SNPs) in a set of 1018 patients with SSc and 1012 controls of French Caucasian origin were genotyped. Two intergenic SNPs, rs10499194 and rs6920220, and one located in TNFAIP3 intron 2, rs5029939, were selected. The TNFAIP3 rs5029939 found to be associated with SSc in this first set was then genotyped in a second set of 465 patients with SSc and 182 controls from Germany and 184 patients with SSc and 124 controls from Italy. Pooled odd ratios were calculated by Mantel-Haenszel meta-analysis.

RESULTS

The rs5029939 G allele was found to be significantly associated with SSc susceptibility (pooled OR=2.08 (95% CI 1.59 to 2.72); p=1.16×10⁻⁷), whereas the rs10499194 and rs6920220 variants displayed no association. Only one of the predicted haplotypes investigated in the French sample was significantly associated with SSc (p=8.91×10⁻⁸), and this haplotype was discriminating only in the presence of the rs5029939 risk allele, suggesting that this SNP tags the association signal. The strongest associations of rs5029939 with subphenotypes, having large magnitudes for complex genetic disorders, were observed for diffuse cutaneous SSc (pooled OR=2.71 (1.94 to 3.79), p=5.2×10⁻⁹), fibrosing alveolitis (pooled OR=2.26 (1.61 to 3.17), p=2.5×10⁻⁶) and pulmonary arterial hypertension (pooled OR=3.11 (1.86 to 5.17), p=1.3×10⁻⁵).

CONCLUSION

These results suggest that TNFAIP3 is a genetic susceptibility factor for SSc.

Association between the IRF5 rs2004640 functional polymorphism and systemic sclerosis: a new perspective for pulmonary fibrosis

OBJECTIVE

There is now growing evidence that connective tissue diseases, including systemic sclerosis (SSc), share a common genetic background. Microarray studies support a pivotal role of type I interferon (IFN) in the pathophysiology of connective tissue diseases. Interferon regulatory factors coordinate the expression of type I IFNs, and the IRF5 gene has been identified as a susceptibility gene of systemic lupus and Sjögren's syndrome. The aim of this study was to determine whether the IRF5 rs2004640 single-nucleotide polymorphism is associated with SSc.

METHODS

The IRF5 rs2004640 (GT) functional polymorphism was genotyped in 1,641 subjects of French European Caucasian origin: a discovery set comprising 427 patients with SSc and 380 control subjects and a replication set comprising 454 patients with SSc and 380 control subjects.

RESULTS

In both the discovery set and the replication set, the TT genotype was significantly more common in patients with SSc than in control subjects, with an odds ratio (OR) for the combined populations of 1.58 (95% confidence interval [95% CI] 1.18-2.11 [P for trend 0.002]). Analyses of the whole SSc population showed a significant association between homozygosity for the T allele and the presence of antinuclear antibodies (corrected P [Pcorr]=0.04, OR 1.59, 95% CI 1.16-2.17) and fibrosing alveolitis (Pcorr=0.001, OR 2.07, 95% CI 1.38-3.11). In a multivariate analysis model including the diffuse cutaneous subtype of SSc and positivity for anti-topoisomerase I antibodies, the IRF5 rs2004640 TT genotype remained associated with fibrosing alveolitis (P=0.029, OR 1.92, 95% CI 1.07-3.44).

CONCLUSION

The IRF5 rs2004640 GT substitution is associated with susceptibility to SSc. These data provide new insight into the pathogenesis of SSc, including clues to the mechanisms leading to fibrosing alveolitis.

Myocardial infarction and Turner's syndrome

This paper reports the case of a patient with Turner's syndrome, who developed a myocardial infarction at the age of 36. Turner's syndrome, associated with gonadal insufficiency, increases atherosclerotic cardiovascular risks that must be assessed during the patient's follow-up.

Thrombolysis of mobile right atrial thrombi following severe pulmonary embolism

Thrombolysis may favorably affect the clinical outcome of mobile right atrial thrombus following pulmonary embolism (PE). We report the case of three patients with mobile right atrial thrombus following PE, in whom fibrinolysis was performed. Atrial mass disappeared on the control echocardiogram, but control ventilation perfusion scan showed new perfusion defects in all patients. Thrombolysis seems successful for the treatment of patients with mobile right atrial thrombus following PE; however, recurrent PE may be induced by fibrinolysis. This may affect the benefit of such therapy and should be taken into account when using this therapeutic treatment.

Effect of homeopathy on analgesic intake following knee ligament reconstruction: a phase III monocentre randomized placebo controlled study

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

The efficacy of homeopathy is still under debate and a recent meta-analysis recommended further randomized double-blind clinical trials to identify any clinical situation in which homeopathy might be effective.

WHAT THIS STUDY ADDS

The complex of homeopathy tested in this study (Arnica montana 5 CH, Bryonia alba 5 CH, Hypericum perforatum 5 CH and Ruta graveolens 3 DH) is not superior to placebo in reducing 24 h morphine consumption after knee ligament reconstruction.

AIMS

The efficacy of homeopathy is still under debate. The objective of this study was to assess the efficacy of homeopathic treatment (Arnica montana 5 CH, Bryonia alba 5 CH, Hypericum perforatum 5 CH and Ruta graveolens 3 DH) on cumulated morphine intake delivered by PCA over 24 h after knee ligament reconstruction.

METHODS

This was an add-on randomized controlled study with three parallel groups: a double-blind homeopathic or placebo arm and an open-label noninterventional control arm. Eligible patients were 18-60 years old candidates for surgery of the anterior cruciate ligament. Treatment was administered the evening before surgery and continued for 3 days. The primary end-point was cumulated morphine intake delivered by PCA during the first 24 h inferior or superior/equal to 10 mg day(-1).

RESULTS

One hundred and fifty-eight patients were randomized (66 in the placebo arm, 67 in the homeopathic arm and 25 in the noninterventional group). There was no difference between the treated and the placebo group for primary end-point (mean (95% CI) 48% (35.8, 56.3), and 56% (43.7, 68.3), required less than 10 mg day(-1) of morphine in each group, respectively). The homeopathy treatment had no effect on morphine intake between 24 and 72 h or on the visual analogue pain scale, or on quality of life assessed by the SF-36 questionnaire. In addition, these parameters were not different in patients enrolled in the open-label noninterventional control arm.

CONCLUSIONS

The complex of homeopathy tested in this study was not superior to placebo in reducing 24 h morphine consumption after knee ligament reconstruction.

[Biomarkers as prognostic factors in pulmonary arterial hypertension. Rationale and study design]

CURRENT SITUATION

Pulmonary arterial hypertension (PAH) is a serious disease. Its prognostic is based on the functional status quantified by the NYHA class and the 6-min walking test, and the hemodynamic data. The algorithms of treatment are solely based on the hemodynamic data and the functional status. The main objective is to test whether basal concentrations of isoprostanes, Big endotheline 1, ADMA, high sensitivity CRP, NT-Pro-BNP and cardiac troponin T are a 3-year prognostic factor in PAH using a combined criterion: death from any cause and pulmonary or cardiopulmonary transplantation.

MATERIALS AND METHODS

This is a multicenter, prospective, prognostic, single blinded study (plasma and urinary samples being blinded). The study started in november 2003, running for 2 years, with a 3 year follow-up for each patient. The main inclusion criterion is PAH. The data analysis will use a multivariable Cox model, taking into account the functional and hemodynamic parameters.

EXPECTED RESULTS

This study will determine whether any of the biomarkers tested provides additional prognostic information in PAH in addition to the functional and hemodynamic parameters.

[Pulmonary embolism with right intra-auricular thrombus. Fatal outcome during fibrinolysis]

INTRODUCTION

The spontaneous prognosis of pulmonary embolism associated with mobile intra-cardiac thrombus is most severe, and the choice of a therapeutic strategy is often difficult.

OBSERVATION

The treatment of a patient with intravenous fibrinolytics for massive pulmonary embolism and right atrium thrombus was complicated by his early death. We attributed his death to the migration of the intra-cardiac thrombus. Indeed, the cardiac ultrasound, performed when the patient's hemodynamic state had worsened, revealed the complete disappearance of the thrombus too early to correspond to its complete lysis (30th minute of fibrinolysis).

COMMENTS

In this pathology, several therapeutic approaches are possible. Surgical removal of the embolus has been validated, but cannot be proposed to all patients since it is a high-risk intervention. Fibrinolysis is generally efficient but exposes the patient to the risk of migration of the intra-cavity thrombus with occasionally deleterious evolution (as in our patient). Heparin treatment alone has been proposed as an alternative when the other two techniques are contraindicated. These techniques currently require assessment in a randomized study, in order to define the appropriate therapeutic strategy.

[Does the time between preoperative interruption of aspirin intake and operation influence postoperative blood loss and transfusion requirement in coronary artery bypass graft?]

OBJECTIVE

Impact of the interval between interruption of aspirin intake and surgery on postoperative bleeding and transfusion in coronary artery bypass graft (CABG), with extracorporeal circulation (ECC).

STUDY DESIGN

Retrospective study.

PATIENTS AND METHODS

Four hundred and twelve patients having undergone CABG were retrospectively reviewed. Three groups were evaluated according to the length of the interval defined above: Group I (< 3 days), Group II (3-7 days), Group III (> 7 days or without aspirin intake). Postoperative blood loss at 3rd, 6th, 12th, and 24th hour and transfusion requirements were assessed for the 3 groups. Aprotinin (low dose, 2 M KIU) was systematically included in the priming of the ECC circuit.

RESULTS

There were no significant differences among groups for weight, size, duration of ECC, and number of bypasses. No significant correlation was noted among the 3 groups for postoperative blood loss and transfusion. Multivariate analysis showed that factors associated to a higher risk of excessive bleeding were ECC duration and number of arterial grafts. Factors associated with a higher risk of transfusion were: emergency, minimum patient temperature during ECC, weight and preoperative haemoglobin level. Aspirine intake was not associated with an increase of bleeding or transfusion.

CONCLUSION

Our study showed that in our practice using systematic low dose of aprotinin when priming the ECC circuit, aspirin did not significantly increase bleeding or transfusion requirements in CABG with ECC, whatever the interval between interruption of aspirin intake and surgery. Consequently, in our practice, aspirin intake is interrupted on hospitalisation, one day before surgery.

[Leukotrienes and 12-HETE: key mediators of angiotensin II-mediated vascular effects.Rol in hypertension]

Arachidonic acid metabolism-derived products are key mediators of angiotensin II-mediated vascular effects. The modulatory effect of cyclooxygenase derived products--in particular thromboxane A2 and prostaglandin H2--in angiotensin II-mediated vascular effects is well established. In contrast, few studies have assessed the involvement of lipoxygenase-derived products in the vascular effects of angiotensin II. Cysteinyl leukotrienes (5-lipoxygenase-derived products) and 12-hydroxyeicosatetraenoic acids (12-HETE) (12-lipoxygenase-derived products) are potent proinflammatory and vasomotor mediators. Their biosynthesis is increased in various models of hypertension. In addition, compelling evidence has suggested that they might contribute to the vasoconstrictor, hypertrophic and mitogenic effects of angiotensin II. The demonstration of their contribution to angiotensin II-mediated vascular effects may explain, at least in part, the vascular inflammatory complications associated with hypertension.

Syntheses and preliminary pharmacological evaluation of the two epimers of the 5-F2t-isoprostane

The total synthesis of the 5-F2t-isoprostane 1 and its 5-epimer 2 from diacetone-D-glucose is described. We report preliminary data on the vascular properties of these compounds.

Increased lipid peroxidation in patients with pulmonary hypertension

Isoprostanes are chemically stable lipid peroxidation products of arachidonic acid, the quantification of which provides a novel approach to the assessment of oxidative stress in vivo. The main objective of this study was to quantify the urinary levels of isoprostaglandin F(2alpha) type III (iPF(2alpha)-III), an F(2)-isoprostane, in patients with pulmonary hypertension (PHT) in comparison with healthy controls. The secondary objective was to test whether baseline iPF(2alpha)-III levels correlate to the reversibility of pulmonary hypertension in response to inhaled NO challenge. Urinary iPF(2alpha)-III levels were measured by gas chromatography-mass spectrometry in 25 patients with PHT, 14 of whom were investigated for response to inhaled NO challenge. Urinary iPF(2alpha)-III levels in PHT patients (225 +/- 27 pmol/mmol creatinine) were 2.3 times as high as in controls (97 +/- 7 pmol/mmol creatinine, p < 0.001). The mean pulmonary arterial pressure variation and the pulmonary vascular resistance variation in response to inhaled NO were correlated to basal iPF(2alpha)-III levels. This study shows that oxidative stress is increased in patients with pulmonary hypertension. Furthermore, iPF(2alpha)-III levels inversely correlate to pulmonary vasoreactivity. These observations are consistent with the hypothesis that free radical generation is involved in PHT pathogenesis.

Formation of isoprostanes in children with type IIa hypercholesterolemia

F2-isoprostanes are stable lipid peroxidation products of arachidonic acid and their quantification provides a novel approach to the assessment of oxidative stress in vivo. F2-isoprostanes are present in increased amounts in adult hypercholesterolemia, but no data exist concerning children. We investigated urinary isoprostaglandin F2, type III production as an index of lipid peroxidation in 15 children presenting with type IIa hypercholesterolemia (serum total cholesterol, 290 [SD +/- 70] mg/dl; low-density lipoprotein cholesterol, 210 [SD +/- 90] mg/dl) compared with 15 sex- and age-paired control children (serum total cholesterol, 160 [SD +/- 20] mg/dl). Urinary levels of isoprostaglandin F2alpha type III were measured by gas chromatography mass spectrometry. Urinary concentrations did not differ significantly in hypercholesterolemic children compared with control children (84.7 [SD +/- 37] vs. 96 [SD +/- 35] pmol/mmol creatinine, respectively). No significant correlation was found with total cholesterol, low-density-lipoprotein and high-density-lipoprotein cholesterol, and apolipoprotein B and A1 serum levels. F2-isoprostane urinary levels in children with type IIa hypercholesterolemia do not differ from those of age- and sex-matched control children and are not correlated to blood lipid parameters, suggesting that hypercholesterolemia is not associated with increased lipid peroxidation in childhood.

Enhanced in vivo lipid peroxidation in scleroderma spectrum disorders

OBJECTIVE

A new family of prostaglandin F2 isomers called F2-isoprostanes, produced by free radical peroxidation of arachidonic acid, has recently been described in vivo. Its quantification has been suggested to be a reliable measure of oxidant injury in vivo. The purpose of this study was to investigate urinary F2-isoprostane formation as an index of lipid peroxidation in scleroderma spectrum disorders.

METHODS

Urine samples were obtained from 52 patients with systemic sclerosis (SSc; n = 37) or undifferentiated connective tissue diseases (UCTD; n = 15) and from 20 healthy volunteers. Urinary isoprostaglandin F2alpha type III (iPF2alpha-III) and 11-dehydro thromboxane B2 (11-dehydroTXB2) concentrations were determined using enzyme immunoassays.

RESULTS

The urinary concentration of iPF2alpha-III was approximately twice as high in patients (mean +/- SEM 229+/-16 pmoles/mmoles creatinine) as in controls (116+/-9 pmoles/mmoles creatinine) (P < 0.0001). However, the urinary concentration of iPF2alpha-III was not significantly different among patients with UCTD, limited SSc, and diffuse SSc (mean +/- SEM 221+/-27 versus 245+/-32 versus 220+/-25 pmoles/mmoles creatinine, respectively). No significant correlation was found between the urinary concentrations of iPF2alpha-III and 11-dehydroTXB2.

CONCLUSION

This study provides evidence of enhanced lipid peroxidation in both SSc and UCTD, and suggests a rationale for antioxidant treatment of SSc. Formation of F2-isoprostanes has to be investigated as a means for the evaluation of such therapy.

Determination of isoprostaglandin F2alpha type III in human urine by gas chromatography-electronic impact mass spectrometry. Comparison with enzyme immunoassay

F2-Isoprostanes are stable lipid peroxidation products of arachidonic acid, the quantification of which provides an index of oxidative stress in vivo. We describe a method for analysing isoprostaglandin F2alpha type III (15-F2t-IsoP) in biological fluids. The method involves solid-phase extraction on octadecyl endcapped and aminopropyl cartridges. After conversion to trimethylsilyl ester trimethylsilyl ether derivatives, isoprostaglandin F2alpha type III is analysed by mass spectrometry, operated in electronic impact selected ion monitoring mode. We have compared enzyme immunoassay (EIA; Cayman, Ann Arbor, MI, USA) to this method with 30 human urine aliquots following the same extraction procedure in order to determine the agreement between both methods. Isoprostaglandin F2alpha type III concentrations determined with gas chromatography-mass spectrometry (GC-MS) did not agree with those determined with EIA. Our results suggest that GC-MS and EIA do not measure the same compounds. As a consequence, comparison of clinical results using GC-MS and EIA should be avoided.

Using a WWW-based module for problem-based learning in a cardiovascular pharmacology course

The authors have constructed a problem-based learning (PBL) computer program that makes full use of Internet facilities, and is aimed at providing a stimulating supplement to standard teaching practices. The authors report on students' reactions to this new method of teaching.

Isoprostaglandin E2 type-III (8-iso-prostaglandin E2) evoked contractions in the human internal mammary artery

E2-isoprostanes are recently discovered compounds that are produced in vivo from free radical-catalysed peroxidation of arachidonic acid. One such compound whose formation is favoured by this mechanism is isoprostaglandin E2 type III (iPE2-III, also named 8-iso-prostaglandin E2 or 15-E2t-isoprostaglandin). The aim of this study was to evaluate the vasomotor properties of iPE2-III in isolated human internal mammary artery. In organ bath, iPE2-III was approximately 10 times more potent than isoprostaglandin F2alpha-III and 27 times more potent than prostaglandin E2, whereas both isoprostaglandin F3alpha-III and 15-epi-isoprostaglandin F2alpha-II induced weak contractions. The responses to iPE2-III were inhibited in a concentration-dependent manner by the thromboxane A2 receptor antagonist GR 32191 (3.10(-9) to 3.10(-7) M). Indomethacin, a cyclooxygenase inhibitor and phosphoramidon, an endothelin converting enzyme inhibitor, did not affect iPE2-III response. These data shows that iPE2-III is a more potent vasoconstrictor of human internal mammary arteries than isoprostaglandin F2alpha-III. These effects are mediated by TP receptors, but involve neither cyclooxygenase products nor endothelins. iPE2-III production may induce more pronounced vasomotor effects than isoprostaglandin F2alpha-III in situations of oxidative stress, and in particular may modulate internal mammary artery tone following coronary bypass surgery.

Vascular biology of the isoprostanes

Isoprostanes are a family of compounds produced from polyunsaturated fatty acids via a free-radical-catalysed mechanism. F(2)-isoprostanes are prostaglandin F(2alpha) isomers derived from arachidonic acid. These compounds induce potent vasoconstriction, mediated primarily by TP receptor stimulation, and in some vessels by the release of cyclooxygenase products. This vasoconstriction may be modulated by the endothelium through the release of NO. Potent vasoconstriction is also observed with E(2)-isoprostanes. Experimental and clinical data suggest a role for F(2)-isoprostanes in atherogenesis. These compounds can be detected in free forms in biological fluids as well as esterified in low-density lipoproteins or cell membranes. Their quantification represents a reliable marker of lipid peroxidation. Elevated levels of F(2)-isoprostanes in biological fluids in pathological conditions including atherosclerosis, ischaemia-reperfusion injury, and inflammatory vascular diseases, suggest a relationship between lipid peroxidation and such diseases. F(2)-isoprostanes are currently being investigated as non-invasive quantitative markers to monitor the response to anti-oxidant treatment.

Urinary F2-isoprostanes formation in kidney transplantation

BACKGROUND

Oxygen free-radical mediated lipid peroxidation has been implicated in many diseases such as chronic renal failure, hemodialysis and chronic kidney transplant rejection. However, insight into the role of free radical generation in kidney transplantation has been constrained by the limitations of current indexes of oxidant stress in vivo. Isoprostaglandin F2alpha type-III (iPF2alpha-III, formerly known as 8-iso-prostaglandin F2alpha) is emerging as a reliable marker of oxidant stress in vivo. The purpose of our study was to investigate iPF2alpha-III formation as an index of lipid peroxidation in the 5 d following kidney transplantation.

METHODS

Urinary iPF2alpha-III measurements were performed by enzyme immunoassay from day I to 5 in 11 patients undergoing kidney transplantation. Results were compared with 11 healthy volunteers matched in sex, age and cigarette smoking.

RESULTS

Urinary excretion of iPF2alpha-III at day 1 did not significantly differ between control and transplant group (111 +/- 17 vs. 92 +/- 10 pM/ mM creatinine, respectively, NS). Urinary iPF2alpha-III levels did not differ between day 1 to 5, and were not correlated to cold ischaemia time.

CONCLUSION

Our study shows no evidence of enhanced lipid peroxidation in the first 5 d following kidney transplantation.

Cysteinyl leukotrienes are involved in angiotensin II-induced contraction of aorta from spontaneously hypertensive rats

OBJECTIVE

Non specific lipoxygenase inhibitors have been reported to reduce the in vitro constrictor response and the in vivo pressor effect of angiotensin II in rats. The aim of this study was to assess the role of cysteinyl leukotrienes, in the vascular response to angiotensin II in spontaneously hypertensive rats (SHR).

METHODS

Rings of thoracic aorta from SHR and normotensive Wistar-Kyoto rats (WKY) were compared in terms of contractile responses and release of cysteinyl leukotrienes in response to angiotensin II.

RESULTS

Pretreatment with the specific 5-lipoxygenase inhibitor AA861 10 microM reduced the efficacy of angiotensin II in intact and endothelium-denuded aorta from SHR (% inhibition vs. control: 65+/-12.6% with endothelium (n=6), P<0.05; 43+/-7.2% without endothelium (n=6), P<0.05) but not in aorta from WKY. In addition, in aorta from SHR, the CysLT(1) receptor antagonist MK571 1 microM reduced by 55+/-6.1% (n=6, P<0.05) the contractile effects of angiotensin II in rings with endothelium but not in endothelium-denuded rings. Angiotensin II induced a 8.6+/-2.1-fold increase in cysteinyl leukotriene production in aorta rings from SHR with endothelium which was prevented by the AT(1) receptor antagonist losartan 1 microM but not by the AT(2) receptor antagonist PD123319 0.1 microM. In aorta rings from WKY, cysteinyl leukotriene production remained unchanged after exposition to angiotensin II. The cysteinyl leukotrienes (up to 0.1 microM) induced contractions in aorta rings from SHR but not from WKY.

CONCLUSIONS

These data suggest that cysteinyl leukotrienes, acting at least in part on endothelial CysLT(1) receptors, are involved in the contractile response to angiotensin II in isolated aorta from SHR but not from WKY.

Angiotensin II-induced contractions in human internal mammary artery: effects of cyclooxygenase and lipoxygenase inhibition

OBJECTIVE

This study investigated, in isolated human internal mammary artery, the involvement of the cyclooxygenase and the lipoxygenase pathways of arachidonic acid metabolism in the contraction induced by angiotensin II.

METHODS

Rings of human internal mammary arteries were suspended in organ baths for recording of isometric tension. In addition, the release of eicosanoids in response to angiotensin II (0.3 microM) was measured by enzyme immunoassay.

RESULTS

In human arterial rings without endothelial dependent relaxation in response to substance P or acetylcholine, the angiotensin II-induced contractions were significantly (P<0.05) reduced by 27% in the presence of GR32191 0.3 microM (thromboxane A(2) (TXA(2)) receptor antagonist) but remained unchanged in the presence of dazoxiben 100 microM (thromboxane synthase inhibitor). In addition, angiotensin II failed to modify TXB(2) and 6-keto-PGF(1alpha) production. These results suggest the contribution of a TXA(2)/PGH(2) agonist other than TXA(2) in angiotensin II-induced contractions. However, indomethacin increased (P<0.05) angiotensin II-mediated contractile response and cysteinyl leukotriene production, suggesting a redirection of arachidonic acid metabolism from the cyclooxygenase pathway to the lipoxygenase pathway. Indeed, the contractions induced by angiotensin II were inhibited (P<0.05) by phenidone 100 microM (cyclooxygenase and lipoxygenase inhibitor), baicalein 100 microM (5-, 12- and 15-lipoxygenases inhibitor), AA861 10 microM (5-lipoxygenase inhibitor) and MK571 1 microM (CysLT(1) receptor antagonist). Cysteinyl leukotrienes were released in response to angiotensin II (pg/mg dry weight tissue: 32+/-9 (basal, n=6) vs. 49+/-9 (angiotensin II 0.3 microM, n=6), P<0.05). LTD(4), and at a lesser degree LTC(4), induced contractions of internal mammary artery and MK571 1 microM abolished the contraction to LTD(4).

CONCLUSIONS

This study suggests that the in vitro vasoconstrictor effects of angiotensin II in human internal mammary artery are enhanced at least in part by eicosanoids produced by the cyclooxygenase pathway, probably PGH(2), acting on TXA(2)/PGH(2) receptors, and by lipoxygenase-derived products, particularly cysteinyl leukotrienes acting on CysLT(1) receptors.

Human internal mammary artery contraction by isoprostaglandin f(2alpha) type-III [8-iso-prostaglandin F(2alpha)]

Isoprostaglandin F(2alpha) type-III (formerly known as 8-iso-prostaglandin F(2alpha)) is produced in large quantities in vivo in clinical situations associated with oxidant stress such as atherosclerosis, hypercholesterolemia, and myocardial reperfusion. Isoprostaglandin F(2alpha) type-III may alter smooth muscle and platelet functions. The aim of this study was to evaluate the effects of isoprostaglandin F(2alpha) type-III on isolated human internal mammary arteries, and to characterise the signalling underlying mechanisms. In organ baths, concentration-dependent contractions of human internal mammary arteries were obtained in response to isoprostaglandin F(2alpha) type-III stimulation. The responses to isoprostaglandin F(2alpha) type-III were inhibited in a concentration-dependent manner by the thromboxane A(2) receptor antagonist, GR 32191 ([1R-[1 alpha(Z), 2beta,3beta,5 alpha(+)-7-[[1, 1'-biphenyl)-4-yl]methoxy]-3-hydroxy-2-(1-piperidinyl) cyclo pentyl]-4-4heptanoic acid], hydrochloride), 3x10(-9) to 3x10(-7) M). However, this effect was associated with a decreased maximal contraction. AH 6809 (6-isopropoxy-9-oxoxanthene-2-carboxylic acid, 10(-6) to 3x10(-5) M), an EP(1)-DP receptor antagonist had no effect on isoprostaglandin F(2alpha) type-III-induced contractions. The maximal responses to isoprostaglandin F(2alpha) type-III were significantly reduced in the presence of the cyclooxygenase inhibitor indomethacin (10(-5) M) (E(max): 147+/-20% vs. 213+/-19% in control group, P<0.05). Isoprostaglandin F(2alpha) type-III stimulated thromboxane B(2) release (5.7-fold increase) from human internal mammary arteries. Baicaleine, a non-specific lipoxygenase inhibitor, (10(-4) M) and AA 861 (2,3,5-trimethyl-6-(12-hydroxy-5, 10-dodecadiynyl)-1,4 benzoquinone), a 5-lipoxygenase inhibitor (10(-5) M) did not affect isoprostaglandin F(2alpha) type-III response. In conclusion, this study shows that (1) isoprostaglandin F(2alpha) type-III is a vasoconstrictor in human internal mammary arteries, with a potency equivalent to prostaglandin F(2alpha), (2) the contractions induced by isoprostaglandin F(2alpha) type-III are mediated by TP receptor but not EP(1)-DP-receptor activation, (3) thromboxane A(2) but not cysteinyl leukotrienes production is involved in the vascular effects of isoprostaglandin F(2alpha) type-III. Isoprostaglandin F(2alpha) type-III, produced at sites of free radical generation, may play an important role in internal mammary artery spasm in situations of oxidant stress such as coronary bypass surgery.

Vasoconstrictor effects of iso-prostaglandin F2alpha type-III (8-iso-prostaglandin F2alpha) on human saphenous veins

Free radical generation can initiate the peroxidation of arachidonic acid, resulting in a non-cyclooxygenase-dependent production of bioactive prostaglandin F2-like compounds. We have investigated the effects of iso-prostaglandin F2alpha type III, (iPF2alpha-III, formerly named 8-iso prostaglandin F2alpha) on human saphenous veins, and characterized the underlying mechanisms. In organ baths, the contractile effects of iPF2alpha-III were tested on saphenous vein rings coming from 22 patients. iPF2alpha-III induced concentration-dependent contractions of isolated human saphenous veins. The maximal contraction did not differ significantly from that of prostaglandin F2alpha (PGF2alpha). The pD2 values for iPF2alpha-III, PGF2alpha, endothelin-1 (ET-1), and U46619 (a stable thromboxane A2 mimetic) were 6.31+/-0.12, 5.66+/-0.13, 7.37+/-0.08, and 7.99+/-0.31, respectively (p < 0.001 for U46619 vs. iPF2alpha-III and PGF2alpha; and ET-1 vs. PGF2alpha). Emax values of iPF2alpha-III, PGF2alpha, ET-1, and U46619 were 137.7+/-24.3%, 145.9+/-7.5%, 92.9+/-16.8%, and 238.7+/-23.7%, respectively (p < 0.001 for U46619 vs. iPF2alpha-III, PGF2alpha and ET-1; and for PGF2alpha vs. ET-1). The responses to iPF2alpha-III were inhibited by GR 32191 10(-7) M, a TP-receptor antagonist, without affecting the maximal response (pD2 values were 5.98+/-0.06 in the absence, and 5.22+/-0.05 in the presence of GR32191; p < 0.001). Concentration-effect curves to iPF2alpha-III were not affected by phosphoramidon 10(-5) M (an endothelin converting enzyme inhibitor), BQ123 10(-6) M (a selective ET(A)-receptor antagonist), BQ788 10(-6) M (a selective ET(B)-receptor antagonist), and indomethacin 10(-5) M (a cyclooxygenase inhibitor). Finally, the contractile response of iPF2alpha-III did not involve the release of thromboxane B2 and ET-1, measured using enzyme immunoassays. This study demonstrates that iPF2alpha-III is a vasoconstrictor of human saphenous veins, with a potency fourfold greater than that of PGF2alpha, and 50 times less than that of the thromboxane A2 mimetic, U46619. These effects are mediated at least in part by TP-receptor stimulation, but do not involve thromboxane A2 or ET-1 release.

Furosemide inhibits thromboxane A2-induced contraction in isolated human internal mammary artery and saphenous vein

Evidence suggests that, in addition to its diuretic property, furosemide also may exert direct vascular effects. Because thromboxane A2 (TXA2) has a role in the control of vascular tone, we investigated the effect of furosemide on the contraction induced by U46619 (a stable TXA2 mimetic) on isolated human internal mammary artery (IMA) and saphenous vein (SV). Concentration-response curves to U46619 were performed in the absence (vehicle) or the presence of furosemide (0.1-1 mM) on rings of IMA and SV. In addition, the relaxant effect of furosemide (0.1 microM-1 mM) also was evaluated on U46619-precontracted IMA and SV. The participation of cyclooxygenase derivatives was studied by pretreatment with indomethacin. Furosemide (0.1-1.0 mM) caused parallel rightward shifts of U46619 concentration-response curves without affecting the maximal responses in both IMA and SV. Treatment with indomethacin (1 microM) modified neither the inhibitory effect of furosemide on U46619-induced contractions, nor the relaxant effect of furosemide on U46619-induced contractions, nor the relaxant effect of furosemide on U46619-precontracted IMA and SV. In conclusion, furosemide at high concentrations inhibited U46619-induced contraction in human isolated IMA and SV and relaxed U46619-precontracted IMA and SV by mechanisms independent of the release of relaxant prostaglandins. These results suggest that blockade of TXA2 receptors by furosemide may contribute to explaining the therapeutic effects of furosemide in the treatment of severe heart failure.

[Isoprostanes: new markers of oxidative stress in human diseases]

BACKGROUND

Most of the traditional methods used to assess oxidative stress in clinical setting are non specific, unreliable or inaccurate. Recently, a novel family of prostaglandin F2 isomers, called F2-isoprostanes, produced in vivo by a free radical peroxidation of arachidonic acid, has been described. These compounds may produce physiological or pathological effects due to their ability to alter smooth muscle and platelet functions. The quantification of the two major isoforms (isoprostaglandin F2 alpha type-III and VI) in biological fluids and tissues as markers of lipid peroxidation appears to be an important advance in our ability to explore the role of free radicals in the pathogenesis of human disease.

CLINICAL DATA

Urinary excretion of F2-isoprostanes is correlated with age, indicating increased oxidative stress during the normal aging process. High F2-isoprostanes concentration has been described in diseases such as ischemic heart disease, diabetes, Alzheimer's disease and hepatic cirrhosis. The correlation of F2-isoprostane concentrations and human diseases severity in hepatic cirrhosis, cardiac failure and diabetes suggest that these compounds may be of interest as predictive markers.

PERSPECTIVES

Preliminary studies suggest the use of F2-isoprostanes as prognosis markers. In addition, F2-isoprostanes quantification offers promising potential as intermediate endpoints for clinical studies of antioxidant therapies.

[Isoprostanes: new markers of oxidative stress. Fundamental and clinical aspects]

A novel family of prostaglandin F2 isomers, called F2-isoprostanes, produced in large quantities in vivo by a free radical peroxidation of arachidonic acid, has recently been described. The quantification of the two major isoforms (isoprostaglandin F2alpha type-III and VI) in biological fluids and tissues as markers of lipid peroxidation appears to be an important advance in our ability to explore the role of free radicals in the pathogenesis of human disease. In addition, F2-isoporstanes quantification seems promising as intermediate endpoints for clinical studies of antioxidant therapies.

Thromboxane A(2) modulates cyclic AMP relaxation and production in human internal mammary artery

Two forms of thromboxane A(2) (TP) receptors, TPalpha and TPbeta receptors, have recently been cloned. These receptors regulate adenylate cyclase activity in two opposite ways: TPalpha receptors activate, whereas TPbeta receptors inhibit adenylate cyclase and cAMP generation. The aim of this study was to examine the effects of the thromboxane A(2) analogue, U46619 (9,11-dideoxy-9alpha,11 alpha-methanoepoxy-prostaglandin F(2alpha)), on forskolin-induced relaxation and cAMP accumulation in human internal mammary artery (IMA) and saphenous vein (SV). In organ baths, IMA rings precontracted with U46619 (3.10(-9) and 3.10(-8) M) were less sensitive to forskolin than rings precontracted with methoxamine (3. 10(-6) M). In contrast, the sensitivity to forskolin was similar in SV rings contracted with the same concentrations of these agonists. U46619 reduced significantly the ten-fold increase in cAMP induced by forskolin in IMA but not in SV rings. Sensitivity and maximal relaxation in response to sodium nitroprusside were not altered in either IMA or SV. In summary, stimulation of TP receptors with the thromboxane A(2) analogue, U46619, inhibited the cAMP pathway of relaxation through the inhibition of cAMP synthesis in human IMA but not in SV. It is suggested that thromboxane A(2) may play a role in the control of muscle tone in IMA both by its potent contractile effect and by its inhibitory effect on the cAMP pathway of relaxation.

Are isoprostanes a clinical marker for antioxidant drug investigation?

Numerous pathological conditions are suspected to involve free radical production as part of their pathogenic process. Therefore, a pharmacological control of oxidative stress could probably benefit many vascular, inflammatory or degenerative diseases. However, the development of antioxidant drugs and their clinical evaluation are limited by the absence of an accurate, reliable and easy-to-handle marker of tissue oxidative events. Isoprostanes (isoPs), a prostaglandin-related series of metabolites, are emerging as major candidates for clinical measurement of oxidative stress. They are chemically stable products of lipid peroxidation, formed in cellular membranes and subsequently released and excreted in the urine. Many recent clinical studies have reported that urinary and plasma levels of isoPs (in particular the iPF2alpha-III isomer also called 8-epi-PGF2alpha) are increased in clinical conditions where oxidative stress is suspected to play a pathogenic role. Moreover, isoPs have been detected in tissue extracts from atherosclerotic plaques and Alzheimer patients brain tissue. Finally, antioxidant treatments such as vitamin E supplementation appear to reduce isoPs levels in biological fluids of treated patients. These preliminary observations argue for a further investigation of isoPs as a practical pharmacodynamic endpoint for the clinical evaluation of antioxidant therapies.

[In vitro study of of the effects of cysteinyl leukotrienes on human vascular preparations]

Leukotrienes are 5-lipoxygenase-derived arachidonic acid metabolites. In addition to their bronchoconstrictor effects, leukotrienes are also important modulators of the vascular tone which may exert paradoxical effects. Indeed, depending on the vascular tone (in either the basal or norepinephrine-precontracted state), leukotrienes are capable of inducing either contraction or relaxation. These paradoxical effects of leukotrienes depend on the vascular bed and the species investigated. Since urinary LTE4 excretion is increased in various cardiovascular diseases, including arterial pulmonary hypertension or cardiac ischaemia, the study of the effects of leukotrienes on human vascular preparations is of interest. This article reviews the in vitro evidence linking cysteinyl leukotrienes to the modulation of the vascular tone on human vascular preparations.

[Compression of the renal artery by a musculo-tendinous band: an unrecognised cause of renovascular hypertension]

Stenosis of a renal artery by extrinsic compression is an uncommon cause of renovascular hypertension. In rare cases, this compression is due to the presence of fibres from the diaphragm or the psoas muscle. This aetiology should be considered when renal artery stenosis is observed in a young hypertensive patient without cardiovascular risk factors. Spiral CT scan is particularly useful for studying the relationship between the diaphragm and arterial structures. Once the diagnosis has been made, the treatment is surgical section of the fibrous tissues responsible for the compression.

Vasorelaxant actions of enoximone, dobutamine, and the combination on human arterial coronary bypass grafts

Enoximone (a type III-selective phosphodiesterase inhibitor) and dobutamine (a beta-receptor agonist) are positive inotropic drugs frequently used in the postoperative management of coronary bypass surgery. The purpose of this study was to characterize their relaxant effects on the human internal mammary artery (IMA) and the gastroepiploic artery (GEA) and to test the hypothesis that their combination may have greater than additive relaxant effects. In organ baths, the relaxant effects of enoximone and dobutamine were tested on rings of IMA (n = 86) precontracted with U46619 (a thromboxane A2 mimetic), norepinephrine (NE), or KCl. The relaxant effects of dobutamine and enoximone also were tested on rings of GEA (n = 42) precontracted with U46619 and NE. The effect of the combination of enoximone and dobutamine were tested on rings of IMA (n = 24) precontracted with U46619 or NE. With respect to maximal relaxations induced by papaverine (10(-4) M), enoximone (< or =10(-3) M) caused full relaxations of IMA precontracted with NE, U46619, or KCI. Dobutamine (< or =10(-3) M) caused full relaxations of IMA precontracted with NE or KCI but only 46% (95% CI, 27-65) relaxation in the rings precontracted with U46619. Similar patterns of relaxation were observed in GEA rings, with dobutamine inducing partial relaxation in GEA precontracted with U46619. The pD2 values of enoximone and dobutamine were both significantly lower in segments precontracted with U46619. The in vitro threshold relaxant concentrations were in the upper limits or over the range of therapeutic plasma concentrations. The relaxant effect of the combination was significantly more important than the theoretic additive effect in IMA contracted with U46619 or NE. Enoximone and dobutamine are potent in vitro vasodilators but exert weak relaxant effects in IMA and GEA at concentrations in the therapeutic range. There is, however, a greater than additive vasorelaxant effect of the combination, suggesting that the vasorelaxant effect of the combination, in addition to the additive inotropic effect, may be beneficial to patients undergoing coronary bypass grafting.

Reactivity of the Human Internal Mammary Artery and the Gastroepiploic Artery to Constrictor Substances

The internal mammary artery (IMA) and the gastroepiploic artery (GEA) are frequently used to construct coronary artery bypass grafts. In order to determine and to compare their contractile properties, we studied the effects of constricting agents which are liberated or infused during coronary bypass surgery. IMA and GEA were arranged as ring segments and suspended in organ baths at optimal stretch using a normalization procedure. Concentration-contraction curves to angiotensin II, norepinephrine, U-46619, endothelin-1, leukotriene C(4) and KCl were performed. The sensitivity (pD(2)) of GEA and IMA to all the agents did not differ. However, GEA developed stronger maximal contraction force than IMA to angiotensin II (P < 0.001), norepinephrine (P < 0.05), U-46619 (P = 0.06), endothelin-1 (P < 0.01), and KCl (P < 0.01), whereas leukotriene C(4) did not induce a significant contraction on GEA and IMA. The higher contractility of GEA may explain that it is more prone to spasm than IMA in the clinical setting. This study reinforces IMA as a first-choice conduit for coronary artery bypass and emphasizes the need for antispastic drugs particularly when GEA is used as bypass vessel.http://link.springer-ny.com/link/service/journals/00547/bibs/8n4p187.html</hea

Functional comparison of the human isolated femoral artery, internal mammary artery, gastroepiploic artery, and saphenous vein

Human femoral, internal mammary, and gastroepiploic arteries and saphenous veins are used as bypass grafts for coronary surgery or for reconstruction in arterial occlusive disease. We have characterized the contractile responses of these vessels to various agents that are liberated during cardiac or vascular surgery. In organ baths, U46619 (a stable thromboxane A2 mimetic), norepinephrine, endothelin-1, angiotensin II, and KCl caused concentration-dependent contractions in all vessels tested. Leukotriene C4 did not induce any contraction in the arteries, whereas a contraction was obtained in the saphenous vein rings. U46619 induced the most powerful contraction in all vessels tested. The pD2 values for each agent did not differ among the different vessels. When responses were expressed as a percentage of KCl-induced contraction, the contraction of endothelin-1 (151+/-5%) and leukotriene C4 (43+/-5%) was more significant on saphenous veins than on arteries. In conclusion, thromboxane A2 appears to be the most potent endogenous constricting agent on different human vascular beds. Our second finding is that saphenous veins are more sensitive to contract to leukotriene C4 and endothelin-1 than arteries. These properties may influence early and (or) long-term vein graft patency.