Non-linearity and gaps in results distribution over successive Roche Lipase method applications: improvement but persistence.

Non-linearity within the primary measurement range of a lipase assay (<300 U/L) has been shown on Cobas® Roche analyzers, causing gaps in results distribution between 300 and 400 U/L. Since, new lipase method applications (LMAs) have been used. The purpose is to retrospectively evaluate their impact on relative frequencies of lipase results (RFLs).Plasma lipase results from two hospital laboratories, assayed over 7.2 years, were collected. Over this period, three successive LMAs, characterized by automated repeat-on-dilution (1/11, 1/2, or 1/10), were applied for lipase results >300 U/L: LMA1 and LMA2 on the Modular®P800, Cobas®c501 and Cobas®C701 analyzers, and LMA3 on the Cobas®C701. RFLs were determined, linearity tests were performed, and inter-agreements between lipase results corrected and uncorrected for nonlinear biases were assessed, using 180 U/L as a decisional cut-off for acute pancreatitis.Overall, RFL gaps narrowed from LMA1 (300 to ∼380 U/L) to LMA3 (300 to ∼330 U/L). For a lipase activity fixed at 300 U/L, non-linearity biases were determined at -11.2% on the Modular®P800 (LMA1), -20.8% on the Cobas®c501 (LMA1), and -3.5% (LMA2) and -2.2% (LM3) on the Cobas®C701. Diagnostically, a maximum of 0.48% lipase results were misclassified as negative (LMA1 on the Cobas®c501), and a minimum of 0.01% misclassified as negative (LMA3 on the Cobas®C701). In conclusion, successive Roche lipase method applications improved linearity within the primary measurement range. While persisting, gaps in lipase results distribution narrowed with the evolution of the methods, with a minor impact in terms of diagnostic of acute pancreatitis.

Imbalance of the Vanin-1 Pathway in Systemic Sclerosis.

Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of the skin and visceral organs and vascular alterations. SSc pathophysiology involves systemic inflammation and oxidative stress. Because the vanin-1 gene (vnn1) encodes an enzyme with pantetheinase activity that converts vasculoprotective pantethine into profibrotic pantothenic acid and pro-oxidant cystamine, we tested this pathway in the pathophysiology of SSc. Activation of the vanin-1/pantetheinase pathway was investigated in wild-type BALB/c mice with hypochlorous acid (HOCl)-induced SSc by ELISA and Western blotting. We then evaluated the effects of the inactivation of vnn1 on the development of fibrosis, endothelial alterations, and immunological activation in mice with HOCl- and bleomycin-induced SSc. We then explored the vanin-1/pantetheinase pathway in a cohort of patients with SSc and in controls. In wild-type mice with HOCl-induced SSc, the vanin-1/pantetheinase pathway was dysregulated, with elevation of vanin-1 activity in skin and high levels of serum pantothenic acid. Inactivation of the vnn1 gene in vnn1-/- mice with HOCl-induced SSc prevented the development of characteristic features of the disease, including fibrosis, immunologic abnormalities, and endothelial dysfunction. Remarkably, patients with diffuse SSc also had increased expression of vanin-1 in skin and blood and elevated levels of serum pantothenic acid that correlated with the severity of the disease. Our data demonstrate that vanin-1/pantetheinase controls fibrosis, vasculopathy, autoimmunity, and oxidative stress in SSc. The levels of vanin-1 expression and pantothenic acid determine SSc severity and can be used as markers of disease severity. More importantly, inhibition of vanin-1 can open new therapeutic approaches in SSc.

Protein oxidative stress markers in peritoneal fluids of women with deep infiltrating endometriosis are increased.

STUDY QUESTION: Are protein oxidative stress markers [thiols, advanced oxidation protein products (AOPP), protein carbonyls and nitrates/nitrites] in perioperative peritoneal fluid higher in women with histologically proven endometriosis when compared with endometriosis-free controls? SUMMARY ANSWER: Protein oxidative stress markers are significantly increased in peritoneal fluids from women with deep infiltrating endometriosis with intestinal involvement when compared with endometriosis-free controls. WHAT IS KNOWN ALREADY: Endometriosis is a common gynaecologic condition characterized by an important inflammatory process. Various source of evidence support the role of oxidative stress in the development of endometriosis. STUDY DESIGN, SIZE, DURATION: We conducted a prospective laboratory study in a tertiary-care university hospital between January 2011 and December 2012, and included 235 non-pregnant women, younger than 42 year old, undergoing surgery for a benign gynaecological condition. PARTICIPANTS/MATERIALS, SETTING, METHODS: After complete surgical exploration of the abdomino-pelvic cavity, 150 women with histologically proven endometriosis and 85 endometriosis-free controls women were enrolled. Women with endometriosis were staged according to a surgical classification in three different phenotypes of endometriosis: superficial peritoneal endometriosis (SUP), ovarian endometrioma (OMA) and deeply infiltrating endometriosis (DIE). Perioperative peritoneal fluids samples were obtained from all study participants. Thiols, AOPP, protein carbonyls and nitrates/nitrites were assayed in all peritoneal samples. MAIN RESULTS AND THE ROLE OF CHANCE: Concentrations of peritoneal AOPP were significantly higher in endometriosis patients than in the control group (median, 128.9 µmol/l; range, 0.3-1180.1 versus median, 77.8 µmol/l; range, 0.8-616.1; P < 0.001). In a similar manner concentrations of peritoneal nitrates/nitrites were higher in endometriosis patients than in the control group (median, 24.8 µmol/l; range, 1.6-681.6 versus median, 18.5 µmol/l; range, 1.6-184.5; P < 0.05). According to the surgical classification, peritoneal fluids protein AOPP and nitrates/nitrites were significantly increased only in DIE samples when compared with controls (P < 0.001 and P < 0.05; respectively), whereas the others forms of endometriosis (SUP and OMA) showed non-statistically significant increases. We found positive correlations between peritoneal fluids AOPP concentrations, nitrites/nitrates levels and the total number of intestinal DIE lesions (r = 0.464; P < 0.001 and r = 0.366; P = 0.007; respectively). LIMITATIONS, REASONS FOR CAUTION: Inclusion of only surgical patients may constitute a possible selection bias. In fact, our control group involved women who underwent surgery for benign gynaecological conditions. This specificity of our control group may lead to biases stemming from the fact that some of these conditions, such as fibroids, ovarian cysts or tubal infertility, might be associated with altered peritoneal proteins oxidative stress markers. WIDER IMPLICATIONS OF THE FINDINGS: We demonstrate the existence of a significantly increased protein oxidative stress status in peritoneal fluid from women with endometriosis especially in cases of DIE with intestinal involvement. This study opens the way to future more mechanistics studies to determine the exact role of protein oxidative stress in the pathogenesis of endometriosis. Even if an association does not establish proof of cause and effect, these intrinsic biochemical characteristics of endometriosis may lead to the evaluation of therapeutic approaches targeting oxidative imbalance. STUDY FUNDING/COMPETING INTERESTS: No funding was used for this study. The authors have no conflict of interest.

Reactive oxygen species-mediated killing of activated fibroblasts by arsenic trioxide ameliorates fibrosis in a murine model of systemic sclerosis.

OBJECTIVE: In patients with systemic sclerosis (SSc), activated fibroblasts produce reactive oxygen species (ROS) that stimulate their proliferation and collagen synthesis. By analogy with tumor cells that undergo apoptosis upon cytotoxic treatment that increases ROS levels beyond a lethal threshold, we tested whether activated fibroblasts could be selectively killed by the cytotoxic molecule arsenic trioxide (As(2) O(3) ) in a murine model of SSc. METHODS: SSc was induced in BALB/c mice by daily intradermal injections of HOCl. Mice were simultaneously treated with daily intraperitoneal injections of As(2) O(3) . RESULTS: As(2) O(3) limited dermal thickness and inhibited collagen deposition, as assessed by histologic examination and measurement of mouse skin and lung collagen contents. As(2) O(3) abrogated vascular damage, as shown by serum vascular cell adhesion molecule 1 level, and inhibited the production of autoantibodies, interleukin-4 (IL-4), and IL-13 by activated T cells. These beneficial effects were mediated through ROS generation that selectively killed activated fibroblasts containing low levels of glutathione. CONCLUSION: Our findings indicate that treatment with As(2) O(3) dramatically improves skin and lung fibrosis in a mouse model of SSc, providing a rationale for the evaluation of As(2) O(3) treatment in patients with SSc.

Prognostic value of soluble urokinase plasminogen activator receptor in patients presenting to the emergency department with chest pain suggestive of acute coronary syndrome.

INTRODUCTION: Soluble urokinase plasminogen activator receptor (suPAR) is a prognostic biomarker of cardiovascular disease. OBJECTIVES: We aimed to evaluate the early prognostic value of suPAR in patients presenting to the emergency department (ED) with chest pain suggestive of acute coronary syndrome (ACS). PATIENTS AND METHODS: In a post-hoc analysis from a multicenter study including patients with a chest pain < 6 h, suPAR concentrations at ED admission were studied according to the outcome at 30-days. RESULTS: 198 patients (median age 56 years) in whom 16% had an ACS, were included. Fifteen (7.3%) patients presented a 30-day event. At ED admission, median (IQR) suPAR concentrations were higher in patients with a 30-day event in comparison to patients without event (4.54 (3.09-8.61) vs. 2.72 (2.10-3.43) ng/mL, p < 0.001). The ROC curve AUC of suPAR for the prediction of a 30-days event was 0.775 [95%CI: 0.710-0.831]. The optimal threshold was 3.3 ng/mL, with a sensitivity of 73 [45-92] % and a specificity of 72 [65-79] %. The association of a suPAR < 3.3 ng/mL AND a NT-proBNP < 160 ng/L AND a HEART score < 4 had a negative predictive value of 99 [91-100] %. A suPAR value at admission above 3.3 ng/mL was independently and significantly associated with a 30-day event in chest pain emergency patients (OR 4.87 [1.35-17.51], p = 0.015). CONCLUSION: suPAR is a promising biomarker for early prediction of events in chest pain emergency patients.

Expression and extracellular release of Trx80, the truncated form of thioredoxin, by TNF-alpha- and IL-1beta-stimulated human synoviocytes from patients with rheumatoid arthritis.

Thioredoxin (Trx) plays several important roles, through changes to sulfhydryl reactions and protein interactions, in controlling cellular signalling processes in RA (rheumatoid arthritis). Trx80, the 10 kDa C-terminal truncated form of Trx, is a potent mitogenic cytokine and is involved in the Th1 response. In the present study, we have investigated the ability of synoviocytes from five RA patients to induce Trx80 after ex vivo stimulation by the pro-inflammatory cytokines IL-1beta (interleukin-1beta) and TNF-alpha (tumour necrosis factor-alpha) or by H(2)O(2). Synoviocytes from five OA (osteoarthritis) patients were used as controls. Immunoprecipitation assays using two different antibodies showed that RA, but not OA, cells expressed intact Trx80 protein in culture even when not stimulated. Treatment with pro-inflammatory cytokines alone or in combination enhanced this basal production and induced the extracellular release of Trx80 by all of the RA cells tested. Under our experimental conditions, the rate of Trx80 release from RA cells was approx. 30% of the total Trx produced. In contrast, Trx80 was not detected in response to H(2)O(2) in RA or OA synoviocyte lysates and their respective culture supernatants, indicating that the oxidative process induced by H(2)O(2) in synoviocytes was unable to modify Trx80 release. Moreover, Trx80 induced synoviocyte proliferation as evaluated by [(3)H]thymidine incorporation. These results highlight the effect of the inflammatory process on the release of both Trx and Trx80 from RA synoviocytes, and suggest that the cytokine-induced increase in Trx80 cell release may constitute a link between inflammation and the immune system in RA.

Impairment of thioredoxin reductase activity by oxidative stress in human rheumatoid synoviocytes.

The thioredoxin/thioredoxin reductase system is strongly induced in patients with rheumatoid arthritis (RA). We have investigated the impact on TR activity of doses of superoxide anion generated by the hypoxanthine (HX)/xanthine oxidase (XO) system and by hydrogen peroxide, H(2)O(2), for various times and compared the findings with synoviocytes obtained from osteoarthritis (OA) patients. At baseline, TR activity in RA cells was significantly higher than in OA cells (2.31 +/- 0.65 versus 0.74 +/- 0.43 mUnit/mg protein, p < 0.01). HX/XO and H(2)O(2) in RA cells decreased TR activity, which was found to be unchanged in OA cells. H(2)O(2) and superoxide anion caused a time-dependent accumulation of oxidized TR and induced the formation of carbonyl groups in TR protein in RA cells rather than OA cells, and oxidized the selenocysteine of the active site. The oxidation in TR protein was irreversible in RA cells but not in OA cells. In conclusion, we report that the oxidative aggression generates modifications in the redox status of the active site of the TR and induces an alteration of the Trx/TR system, concomitant with those of the other antioxidant systems that could explain the causes of oxidative stress related to RA disease.

High redox thioredoxin but low thioredoxin reductase activities in the serum of patients with rheumatoid arthritis.

BACKGROUND: Thioredoxin (Trx)/thioredoxin reductase (TrxR) is a redox-active system induced by oxidative stress. We investigated its status as a function of RA disease activity. METHODS: 64 consecutive RA patients and 27 healthy subjects were enrolled in the study. Serum Trx protein levels were evaluated using an immunoassay and immunoblot, while redox Trx and TrxR activities and oxidative stress markers (carbonyl groups, thiols), were determined using spectrophotometric methods. RESULTS: Redox Trx activity and Trx protein concentrations were significantly higher in RA patients than in controls (redox Trx activity: 37.7+/-22.6 versus 21.1+/-7.9 ng/mL, p<0.01; Trx protein: 25.5+/-12.0 versus 12.3+/-5.1 ng/mL, p<0.0001). Redox Trx activity correlated with the DAS score (r=0.45, p=0.004) and with the tender joint count (r=0.49, p=0.002) whereas there was no correlation with Trx protein concentrations. Immunoblot analysis showed that circulating Trx was partially aggregated. TrxR activity was lower in the serum of RA patients than in healthy subjects (197+/-70 versus 263+/-56 U/L, p=0.002). TrxR activity was correlated with the DAS score (r=0.53, p<0.001) and with the tender joint count (r=0.36, p<0.01). There were no correlations between oxidative stress marker levels and redox Trx activity, Trx protein concentrations or TrxR activity. CONCLUSION: Redox Trx and TrxR activities correlated with the disease activity of RA patients consistent with the hypothesis that Trx/TrxR activities may contribute to disease activity in RA.

Pantethine Prevents Murine Systemic Sclerosis Through the Inhibition of Microparticle Shedding.

OBJECTIVE: Endothelial cell (EC) damage in systemic sclerosis (SSc) is reflected by the shedding of microparticles (MPs). The aim of this study was to show that inhibiting MP release using pantethine or by inactivating ATP-binding cassette transporter A1 (ABCA1) ameliorates murine SSc. METHODS: First, the effects of pantethine on MP shedding and on basal oxidative and nitrosative stresses in ECs and fibroblasts were determined in vitro. The effects of pantethine were then tested in vivo. SSc was induced in BALB/c mice by daily intradermal injection of HOCl. Mice were simultaneously treated daily with pantethine by oral gavage. RESULTS: In vitro, pantethine inhibited MP shedding from tumor necrosis factor-stimulated ECs and abrogated MP-induced oxidative and nitrosative stresses in ECs and fibroblasts. Ex vivo, pantethine also restored redox homeostasis in fibroblasts from mice with SSc. In vivo, mice with SSc displayed skin and lung fibrosis associated with increased levels of circulating MPs and markers of oxidative and endothelial stress, which were normalized by administration of pantethine or inactivation of ABCA1. CONCLUSION: Pantethine is a well-tolerated molecule that represents a potential treatment of human SSc.

Acute and sustained effects of dihydropyridine-type calcium channel antagonists on oxidative stress in systemic sclerosis.

PURPOSE: To evaluate the potential antioxidant properties of dihydropyridine calcium channel antagonists in systemic sclerosis. METHODS: Forty-two patients with systemic sclerosis were included (mean [+/- SD] age, 54 +/- 12 years; mean disease duration, 8 +/- 7 years). Plasma markers of oxidative stress (carbonyl residues, advanced oxidation protein products, malondialdehyde, nitrosothiols, and total thiol groups) were determined 72 hours after the discontinuation of usual dihydropyridine treatment (with either nifedipine or nicardipine), shortly after reinitiation of treatment, and 9 to 12 months later (long-term treatment) in 19 of the patients. Baseline values were compared with those in 23 healthy volunteers. RESULTS: Mean levels of plasma markers of oxidative stress were much higher in patients with systemic sclerosis than in controls (carbonyls, 0.4 +/- 0.1 nmol/mg protein vs. 0.3 +/- 0.1 nmol/mg protein, P = 0.0001; advanced oxidation protein products, 111 +/- 13 micromol/L vs. 47 +/- 7 micromol/L, p = 0.003; malondialdehyde, 11.3 +/- 3.3 micromol/L vs. 5.5 +/- 1.3 micromol/L, P <0.0001; nitrosothiols, 1.6 +/- 0.2 micromol/L vs. 0.6 +/- 0.2 micromol/L, P <0.0001). In contrast, thiol levels were lower in systemic sclerosis patients (264 +/- 80 micromol/L vs. 435 +/- 50 micromol/L, P <0.0001). Short-term treatment led to a significant decrease in oxidative stress markers (carbonyls, 0.3 +/- 0.1 nmol/mg protein, P <0.0001), advanced oxidation protein products (60 +/- 3 micromol/L, P <0.0001), malondialdehyde (8.8 +/- 5.6 micromol/L, p = 0.0002), and nitrosothiols (1.4 +/- 0.2 micromol/L, p = 0.0001), but an increase in thiol levels (340 +/- 84 micromol/L, P <0.0001). These decreases persisted with long-term treatment. CONCLUSION: Dihydropyridines significantly decrease oxidative stress in systemic sclerosis patients, in both the short and long term.

Lack of association of eNOS (G894T) and p22phox NADPH oxidase subunit (C242T) polymorphisms with systemic sclerosis in a cohort of French Caucasian patients.

OBJECTIVE: To assess the influence of endothelial nitric oxide synthase (eNOS) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase polymorphisms on the susceptibility of patients to and clinical expression of systemic sclerosis (SSc). METHODS: Seventy-seven French Caucasian patients with SSc were studied. Patients and ethnically matched controls (n=49) were genotyped, by restriction enzyme digestion of polymerase chain reaction (PCR) products, for G894T polymorphism in exon 7 of the eNOS gene and for C242T polymorphism of the gene encoding the p22(phox) NADPH oxidase subunit. RESULTS: The allele and genotype frequencies of the polymorphisms did not differ between patients with SSc and the controls. Moreover, there was no association between these polymorphisms and disease phenotypes. CONCLUSION: Our results indicate that eNOS (G894T) and p22(phox) (C242T) polymorphisms do not influence susceptibility to and the course of systemic sclerosis.

Chalcone-Coumarin derivatives as potential anti-cancer drugs: an in vitro and in vivo investigation.

Cancer cells display an overproduction of reactive oxygen species resulting from an exaggerated intrinsic oxidative stress. However, the concept of deleterious oxidants versus beneficial antioxidants has recently evolved. Indeed, molecules like natural coumarins have shown anti-oxidant or pro-oxidant properties depending on their intracellular concentration. Therefore, we have investigated the structure-activity relationship of a variety of coumarin derivatives in terms of cytotoxicity towards human and murine carcinoma cell lines (HT29, HepG2, A549, MCF7, OVCAR and CT26). Amongst those compounds, (E)-7-methoxy-4-(3-oxo-3- phenylprop-1-enyl)-2H-chromen-2-one and (E)-7-hydroxy-4-(3-(4-hydroxyphenyl)-3-oxoprop-1-enyl)-2H-chromen-2-one displayed the most potent cytotoxic effect on colon cancer cells, CT26, (IC50=4.9µM) linked to their pro-oxidant properties. Those compounds triggered the in vitro production of reactive oxygen species by tumor cells, leading to their death through a necrotic process. In vivo, molecules also slowed down tumor growth by 65.7% and 35.4%, respectively, without inducing significant side effects.

Treatment of oxaliplatin-induced peripheral neuropathy by intravenous mangafodipir.

BACKGROUND: The majority of patients receiving the platinum-based chemotherapy drug oxaliplatin develop peripheral neurotoxicity. Because this neurotoxicity involves ROS production, we investigated the efficacy of mangafodipir, a molecule that has antioxidant properties and is approved for use as an MRI contrast enhancer. METHODS: The effects of mangafodipir were examined in mice following treatment with oxaliplatin. Neurotoxicity, axon myelination, and advanced oxidized protein products (AOPPs) were monitored. In addition, we enrolled 23 cancer patients with grade ≥ 2 oxaliplatin-induced neuropathy in a phase II study, with 22 patients receiving i.v. mangafodipir following oxaliplatin. Neuropathic effects were monitored for up to 8 cycles of oxaliplatin and mangafodipir. RESULTS: Mangafodipir prevented motor and sensory dysfunction and demyelinating lesion formation. In mice, serum AOPPs decreased after 4 weeks of mangafodipir treatment. In 77% of patients treated with oxaliplatin and mangafodipir, neuropathy improved or stabilized after 4 cycles. After 8 cycles, neurotoxicity was downgraded to grade ≥ 2 in 6 of 7 patients. Prior to enrollment, patients received an average of 880 ± 239 mg/m2 oxaliplatin. Patients treated with mangafodipir tolerated an additional dose of 458 ± 207 mg/m2 oxaliplatin despite preexisting neuropathy. Mangafodipir responders managed a cumulative dose of 1,426 ± 204 mg/m2 oxaliplatin. Serum AOPPs were lower in responders compared with those in nonresponders. CONCLUSION: Our study suggests that mangafodipir can prevent and/or relieve oxaliplatin-induced neuropathy in cancer patients. Trial registration. Clinicaltrials.gov NCT00727922. Funding. Université Paris Descartes, Ministère de la Recherche et de l'Enseignement Supérieur, and Assistance Publique-Hôpitaux de Paris.

Increased serum oxidative stress markers in women with uterine leiomyoma.

BACKGROUND: Uterine leiomyomas (fibroids) are the most common gynaecological benign tumors in premenopausal women. Evidences support the role of oxidative stress in the development of uterine leiomyoma. We have analysed oxidative stress markers (thiols, advanced oxidized protein products (AOPP), protein carbonyls and nitrates/nitrites) in preoperative sera from women with histologically proven uterine leiomyoma. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a laboratory study in a tertiary-care university hospital. Fifty-nine women with histologically proven uterine leiomyoma and ninety-two leiomyoma-free control women have been enrolled in this study. Complete surgical exploration of the abdominopelvic cavity was performed in each patient. Preoperative serum samples were obtained from all study participants to assay serum thiols, AOPP, protein carbonyls and nitrates/nitrites. Concentrations of serum protein carbonyl groups and AOPP were higher in leiomyoma patients than in the control group (p=0.005 and p<0.001, respectively). By contrast, serum thiol levels were lower in leiomyoma patients (p<0.001). We found positive correlations between serum AOPP concentrations and total fibroids weight (r=0.339; p=0.028), serum AOPP and serum protein carbonyls with duration of infertility (r=0.762; p=0.006 and r=0.683; p=0.021, respectively). CONCLUSIONS/SIGNIFICANCE: This study, for the first time, reveals a significant increase of protein oxidative stress status and reduced antioxidant capacity in sera from women with uterine leiomyoma.

Hypoxia induces nitric oxide synthase in rheumatoid synoviocytes: consequences on NADPH oxidase regulation.

We investigated the effects of hypoxia on inducible NO synthase (iNOS) activity and expression in rheumatoid arthritis (RA) synoviocytes. We further studied the relationship between nitrosative stress and NADPH oxidase (NOX) in such conditions. Human cultured synoviocytes were treated for 24 hours with IL-1ß, TNF-α or neither, and submitted to hypoxia or normoxia for the last 6 hours. Nitrite production and iNOS expression were increased under hypoxia conditions in RA cells in comparison to normoxia. Hypoxia did not potentate the basal and cytokine-induced superoxide productions, while NOXs' subunit expression and p47-phox phosphorylation were increased. Nitrosylation of NOXs and p47-phox was not raised under hypoxia conditions. Finally, peroxynitrite production was significantly increased under hypoxia conditions, in comparison to normoxia. Our results provide evidence for upregulation of iNOS and NOX activities in RA synoviocytes under hypoxia conditions, associated to an increased peroxynitrite production. Synovial cell metabolism under hypoxia conditions might be different from that in normoxia.

Oxidative stress markers are increased since early stages of infection in syphilitic patients.

Clinical symptoms of syphilis are the consequence of the spirochete propensity to induce persistent chronic inflammation, which could participate to oxidative stress increase. The present study was designed to evaluate the level of oxidative stress biomarkers and antioxidant defences in a cohort of syphilitic patients. Serum oxidative status was explored in 63 patients diagnosed with early syphilis, 34 consulting patients negative for syphilis and 19 healthy controls. Total plasma thioredoxin (Trx) and thiols were determined as antioxidant capacity markers, °NO, advanced oxidation protein products (AOPP) and protein carbonyl levels as oxidative stress status biomarkers, and CRP as marker of inflammation. Mean serum levels of Trx, AOPP, carbonyls, and nitrates/nitrites were significantly higher, whereas thiols level was lower in syphilitic patients compared to non-syphilitic patients and healthy controls (respectively, p < 0.05/p < 0.01 for Trx, p < 0.005/p < 0.0001 for AOPP, p < 0.05/p < 0.005 for carbonyls, p < 0.005/p < 0.05 for nitrates/nitrites and p < 0.01/p < 0.0001 for thiols). According to the stage of the disease, results highlighted a marked and sustained oxidative stress imbalance from the first stage to the latent period of the disease. Moreover, syphilitic patients presented a low inflammation status reflected by median of CRP level (1.7 mg/L, range 5th-95th percentile from <0.1 to 33.7 mg/L), correlated with antioxidant capacity decrease (thiols) at stage 1 (r = -0.725; p < 0.0001) and nitrosative stress increase (nitrates/nitrites) at stage 2 and latent (respectively, r = 0.285, p < 0.05 and r = 0.650, p < 0.05). These findings indicate that at all stages of the disease, despite a low-grade inflammatory state, syphilis infection generates a major oxidative and nitrosative stress which may be involved in the pathophysiology of the disease.

trans-Resveratrol downregulates Txnip overexpression occurring during liver ischemia-reperfusion.

Txnip (thioredoxin-interacting protein) is a protein with multifunctional roles in cellular responses and stress-related diseases. Txnip is involved in intracellular redox regulation and has been recently described as a possible link between redox state and metabolism. trans-Resveratrol (T-res) is a natural phytoalexin with antiproliferative, antiapoptotic and antioxidative effects. However, to date there have been no reports of the implication of Txnip in a model of liver acute stress such as ischemia-reperfusion (I/R) and no work has looked for a T-res effect on Txnip. Here we studied the effects of a post-ischemic treatment of T-res on the liver thioredoxin (Trx)/Txnip system and investigated whether the T-res effects were dependent on *NO production. In this work, liver I/R induced hepatic Txnip expression and T-res inhibited I/R Txnip expression. This decrease in Txnip expression by T-res was associated with an increase in liver Trx redox activity and a decrease in hepatic I/R-induced Trx-1 expression with no effect on Trx-2, on plasma Trx redox activity or on liver and plasma Trx reductase activity, independently of *NO production. In conclusion, these results show that in our model, not only did T-res protect Trx redox activity by diminishing the Txnip protein expression; it also reduced secretion of Trx1. This is the first report of a major implication of the Trx1/Txnip system in hepatic I/R injuries. It also affirms the importance of the antioxidant effect of T-res on the Trx1/Txnip system.

Nifedipine protects against overproduction of superoxide anion by monocytes from patients with systemic sclerosis.

We have reported previously that dihydropyridine-type calcium-channel antagonists (DTCCA) such as nifedipine decrease plasma markers of oxidative stress damage in systemic sclerosis (SSc). To clarify the cellular basis of these beneficial effects, we investigated the effects in vivo and in vitro of nifedipine on superoxide anion (O2*-) production by peripheral blood monocytes. We compared 10 healthy controls with 12 patients with SSc, first after interruption of treatment with DTCCA and second after 2 weeks of treatment with nifedipine (60 mg/day). O2*- production by monocytes stimulated with phorbol myristate acetate (PMA) was quantified by the cytochrome c reduction method. We also investigated the effects in vitro of DTCCA on O2*- production and protein phosphorylation in healthy monocytes and on protein kinase C (PKC) activity using recombinant PKC. After DTCCA had been washed out, monocytes from patients with SSc produced more O2*- than those from controls. Nifedipine treatment considerably decreased O2*- production by PMA-stimulated monocytes. Treatment of healthy monocytes with nifedipine in vitro inhibited PMA-induced O2*- production and protein phosphorylation in a dose-dependent manner. Finally, nifedipine strongly inhibited the activity of recombinant PKC in vitro. Thus, the oxidative stress damage observed in SSc is consistent with O2*- overproduction by primed monocytes. This was decreased by nifedipine treatment both in vivo and in vitro. This beneficial property of nifedipine seems to be mediated by its cellular action and by the inhibition of PKC activity. This supports the hypothesis that this drug could be useful for the treatment of diseases associated with oxidative stress.

Nifedipine decreases sVCAM-1 concentrations and oxidative stress in systemic sclerosis but does not affect the concentrations of vascular endothelial growth factor or its soluble receptor 1.

Microvascular injury, oxidative stress, and impaired angiogenesis are prominent features of systemic sclerosis (SSc). We compared serum markers of these phenomena at baseline and after treatment with nifedipine in SSc patients. Forty successive SSc patients were compared with 20 matched healthy subjects. All SSc patients stopped taking calcium-channel blockers 72 hours before measurements. Twenty SSc patients were also examined after 14 days of treatment with nifedipine (60 mg/day). Quantitative ELISA was used to measure the serum concentrations of vascular endothelial growth factor (VEGF), soluble VEGF receptor 1 (sVEGFR-1), soluble vascular cell adhesion molecule 1 (sVCAM-1), carbonyl residues, and advanced oxidation protein products (AOPP). The median concentrations of VEGF, sVEGFR-1, sVCAM-1, carbonyl residues, and AOPP were significantly higher in SSc patients than in healthy subjects at baseline. A correlation was found between VEGF concentration and carbonyl residue concentration (r = 0.43; P = 0.007). Nifedipine treatment led to a significant decrease in concentrations of sVCAM-1, carbonyl residues, and AOPP but did not affect concentrations of VEGF and sVEGFR-1. Nifedipine treatment ameliorated endothelium injury in patients with SSc, as shown by the concentrations of adhesion molecules and oxidative damage markers. The fact that VEGF and sVEGFR-1 concentrations were not changed whereas oxidative stress was ameliorated by nifedipine is consistent with the hypothesis that VEGF signalling is impaired in SSc. However, more experimental evidence is needed to determine whether the VEGF pathway is intrinsically defective in SSc.

Correlation of serum collagen I carboxyterminal telopeptide concentrations with cutaneous and pulmonary involvement in systemic sclerosis.

OBJECTIVE: Systemic sclerosis (SSc) is characterized by fibrosis involving the skin and various internal organs. Type I collagen (Col I) is the most abundant extracellular matrix protein deposited in cutaneous involvement. We investigated Col I biochemical markers in patients with SSc. METHODS: All consecutive patients admitted for SSc over a 9 month period and a healthy control group were investigated. Serum concentrations of the C-terminal telopeptide of Col I (s-CTX-I), C-terminal type I procollagen propeptide (PICP), osteocalcin, and bone alkaline phosphatases (ALP), and urinary concentrations of deoxypyridinoline (u-DPD) and u-CTX-I were determined by ELISA. RESULTS: A total of 33 patients with SSc were included: mean age +/- SD was 54 +/- 12 yrs, with a mean disease duration of 5.4 +/- 3.9 years. Sixteen of 33 patients with SSc had s-CTX-I values exceeding the upper limit of normal values of the test and the mean +/- SEM was significantly higher (7388 +/- 1422 pmol/l) than in healthy controls (2800 +/- 1120 pmol/l; p < 0.001). s-CTX-I correlated with the Rodnan skin score (p = 0.003); it was higher in patients with diffuse disease (8459 +/- 3125; n = 14) than in patients with the limited form (6453 +/- 1235; n = 19; p < 0.02). This marker also correlated with acute phase reactants (C-reactive protein, p = 0.004; erythrocyte sedimentation rate, p = 0.02). s-CTX-I was high in patients with positive antitopoisomerase I autoantibodies (p = 0.04) and in patients with a decrease in forced vital capacity to less than 75% (p = 0.02). u-DPD concentration was high in patients with SSc (10.6 +/- 1.4 nmol/mmol creatinine vs 6.3 +/- 2.1 in controls; p < 0.01). No difference between patients and controls or correlations with the disease were found for PICP, u-CTX-I, osteocalcin, and bone ALP concentrations. CONCLUSION: s-CTX-I, a marker of Col I degradation, is correlated with cutaneous and pulmonary involvement and with acute phase reactants in patients with SSc. This marker is a good candidate for further evaluation for disease activity and treatment purposes.