Formation of iron-carbonate scale-layer and corrosion mechanism of API X70 pipeline steel in carbon dioxide-saturated 3% sodium chloride

This work presents the electrochemical results obtained during the study of the corrosion of X70 pipeline steel samples immersed in a 3 % wt NaCl solution saturated with CO2 at 20ºC under static and controlled turbulent flow conditions. In order to control the hydrodynamic conditions of the system, a rotating cylinder electrode (RCE) was used. Electrochemical techniques, Linear Polarization Resistance (LPR) and polarization curves, were used to determine the effect of turbulent flow upon the corrosion kinetics of the steel. We also elucidate the effect of temperature on the corrosion rate of the API X70 steel under the experimental conditions studied. Often, the corrosion of carbon steel in aqueous environments containing CO2 involves the formation of solid iron carbonate, FeCO3, as a corrosion product. The protective property of the formed FeCO3 scale layer to corrosion in brine solutions containing CO2 was established as the possible cause of the corrosion rate decrease above 60ºC

Corrosion study of pipeline carbon steel in sourbrine under turbulent flow conditions at 60°C

This work presents the electrochemical results obtained during the corrosion study of X52 pipeline steel sample, immersed in “sour” solution under turbulent flow conditions at 60°C. In order to obtain information on the corrosion kinetics, weight loss method, linear polarization resistance, impedance and polarization curves were used at different immersion times. In order to control the turbulent flow conditions, a rotating cylinder electrode was used at two different rotation rates, 0 and 1000 rpm. A surface analysis was carried out in order to identify the corrosion morphology and the corrosion product formed on the steel sample. In general, it was found that flow has a considerable influence upon the electrochemical process occurring on the surface of the steel. It was observed as the flow rate increased the corrosion rate also increased. In surface analysis three phases were found, mackinawite (Fe,Ni)  1+xS ,pyrrhothite (Fe(1-x)S) and marcasite (FeS2). In addition, a “localized attack” was found

Review article: The need for more efficient and patient-oriented drug development pathways in NASH—setting the scene for platform trials

Drug development; Non-alcoholic steatohepatitis; Study designsDesenvolupament de fàrmacs; Esteatohepatitis no alcohòlica; Dissenys d'estudiDesarrollo de fármacos; Esteatohepatitis no alcohólica; Diseños de estudioBackground and Aims Non-alcoholic steatohepatitis (NASH) constitutes a significant unmet medical need with a burgeoning field of clinical research and drug development. Platform trials (PT) might help accelerate drug development while lowering overall costs and creating a more patient-centric environment. This review provides a comprehensive and nuanced assessment of the NASH clinical development landscape. Methods Narrative review and expert opinion with insight gained during the EU Patient-cEntric clinicAl tRial pLatforms (EU-PEARL) project. Results Although NASH represents an opportunity to use adaptive trial designs, including master protocols for PT, there are barriers that might be encountered owing to distinct and sometimes opposing priorities held by these stakeholders and potential ways to overcome them. The following aspects are critical for the feasibility of a future PT in NASH: readiness of the drug pipeline, mainly from large drug companies, while there is not yet an FDA/EMA-approved treatment; the most suitable design (trial Phase and type of population, e.g., Phase 2b for non-cirrhotic NASH patients); the operational requirements such as the scope of the clinical network, the use of concurrent versus non-concurrent control arms, or the re-allocation of participants upon trial adaptations; the methodological appraisal (i.e. Bayesian vs. frequentist approach); patients' needs and patient-centred outcomes; main regulatory considerations and the funding and sustainability scenarios. Conclusions PT represent a promising avenue in NASH but there are a number of conundrums that need addressing. It is likely that before a global NASH PT becomes a reality, ‘proof-of-platform’ at a smaller scale needs to be provided.JMP reports having received consulting fees from Boehringer-Ingelheim, MSD and Novo Nordisk. He has received speaking fees from Gilead, Intercept, and Novo Nordisk, and travel expenses from Gilead, Rubió, Pfizer, Astellas, MSD, CUBICIN, and Novo Nordisk. He has received educational and research support from Madrigal, Gilead, Pfizer, Astellas, Accelerate, Novartis, Abbvie, ViiV, and MSD. Funds from European Commission/EFPIA IMI2 853966-2, IMI2 777377, H2020 847989, and ISCIII PI19/01898. NAdP works for Janssen. QMA is Coordinator of the EU IMI-2 LITMUS consortium, which is funded by the EU Horizon 2020 programme and EFPIA. This multistakeholder consortium includes industry partners. He reports research Grant Funding: Allergan/Tobira, AstraZeneca, Boehringer-Ingelheim, Glaxo SmithKline, Glympse Bio, Intercept, Novartis Pharma AG, Pfizer Ltd. Consultancy: 89Bio, Abbvie/Allergan, Akero, Altimentiv, Altimmune, AstraZeneca, Axcella, Blade, BMS, BNN Cardio, Boehringer-Ingelheim, Cirius, CymaBay, EcoR1, E3Bio, Eli Lilly & Company Ltd., Galmed, Genentech, Genfit SA, Gilead, Grunthal, HistoIndex, Indalo, Intercept Pharma Europe Ltd., Inventiva, IQVIA, Janssen, Johnson & Johnson, Madrigal, MedImmune, Medpace, Merck, Metacrine, NGMBio, North Sea Therapeutics, Novartis, Novo Nordisk A/S, PathAI, Pfizer Ltd., Poxel, ProSciento, Raptor Pharma, Roche, Servier, Shionogi, Terns, The Medicines Company, Viking Therapeutics. Speaker: Abbott Laboratories, Allergan/Tobira, BMS, Clinical Care Options, Falk, Fishawack, Genfit SA, Gilead, Integritas Communications, Kenes, Medscape. Royalties: Elsevier Ltd. PM works for Novartis. MSK is an employee of and a shareholder in Novo Nordisk A/S. JG has received consulting fees from Boehringer-Ingelheim, speaking fees from Echosens and travel expenses from Gilead and Abbie. Funds from ISCIII PI18/00947 and PI21/00691. JRE has received speaking fees from Gilead. FT lab’ work has been supported by the German Research Foundation (DFG, CRC/TR 362) and research grants from Gilead, Allergan, Bristol-Myers Squibb and Inventiva. VR consults for and Intercept, Novo Nordisk, Galmed, Poxel, NGM, Madrigal, Enyo, Sagimet, 89 Bio, Prosciento, Terns, and Theratechnologies, and received grants from Intercept and Gilead

Mobilization of xanthine oxidase from the gastrointestinal tract in acute pancreatitis

BACKGROUND: Xanthine oxidoreductase has been proposed to play a role in the development of local and systemic effects of acute pancreatitis. Under physiologic conditions, the enzyme exists mainly as xanthine dehydrogenase (XDH) but can be converted by proteolytic cleavage to its superoxide-generating form xanthine oxidase (XOD). In addition to its intracellular location XDH/XOD is also associated to the polysaccharide chains of proteoglycans on the external endothelial cell membrane. In the early stages of acute pancreatitis, this enzyme seems to be arising from its mobilization from the gastrointestinal endothelial cell surface. Taking into account the ability of α-amylase to hydrolyze the internal α-1,4 linkages of polysaccharides, we wanted to elucidate the involvement of α-amylase in XDH/XOD mobilization from the gastrointestinal endothelial cell surface and the relevance of the ascitic fluid (AF) as the source of α-amylase in experimental acute pancreatitis. METHODS: Acute pancreatitis was induced in male Wistar rats by intraductal administration of 5% sodium taurocholate. In another experimental group 3000 U/Kg α-amylase was i.v. administered. The concentrations of XDH, XOD and α-amylase in plasma and AF and myeloperoxidase (MPO) in lung have been evaluated. In additional experiments, the effect of peritoneal lavage and the absorption of α-amylase present in the AF by an isolated intestine have been determined. RESULTS: Similar increase in XDH+XOD activity in plasma was observed after induction of acute pancreatitis and after i.v. administration of α-amylase. Nevertheless, the conversion from XDH to XOD was only observed in the pancreatitis group. Lung inflammation measured as MPO activity was observed only in the pancreatitis group. In addition peritoneal lavage prevented the increase in α-amylase and XDH+XOD in plasma after induction of pancreatitis. Finally, it was observed that α-amylase is absorbed from the AF by the intestine. CONCLUSIONS: During the early stages of acute pancreatitis, α-amylase absorbed from AF through the gastrointestinal tract could interfere with the binding of XDH/XOD attached to glycoproteins of the endothelial cells. Proteolytic enzymes convert XDH into its oxidase form promoting an increase in circulating XOD that has been reported to be one of the mechanisms involved in the triggering of the systemic inflammatory process

CD32 is expressed on cells with transcriptionally active HIV but does not enrich for HIV DNA in resting T cells

The persistence of HIV reservoirs, including latently infected, resting CD4+ T cells, is the major obstacle to cure HIV infection. CD32a expression was recently reported to mark CD4+ T cells harboring a replication-competent HIV reservoir during antiretroviral therapy (ART) suppression. We aimed to determine whether CD32 expression marks HIV latently or transcriptionally active infected CD4+ T cells. Using peripheral blood and lymphoid tissue of ART-treated HIV+ or SIV+ subjects, we found that most of the circulating memory CD32+ CD4+ T cells expressed markers of activation, including CD69, HLA-DR, CD25, CD38, and Ki67, and bore a TH2 phenotype as defined by CXCR3, CCR4, and CCR6. CD32 expression did not selectively enrich for HIV- or SIV-infected CD4+ T cells in peripheral blood or lymphoid tissue; isolated CD32+ resting CD4+ T cells accounted for less than 3% of the total HIV DNA in CD4+ T cells. Cell-associated HIV DNA and RNA loads in CD4+ T cells positively correlated with the frequency of CD32+ CD69+ CD4+ T cells but not with CD32 expression on resting CD4+ T cells. Using RNA fluorescence in situ hybridization, CD32 coexpression with HIV RNA or p24 was detected after in vitro HIV infection (peripheral blood mononuclear cell and tissue) and in vivo within lymph node tissue from HIV-infected individuals. Together, these results indicate that CD32 is not a marker of resting CD4+ T cells or of enriched HIV DNA–positive cells after ART; rather, CD32 is predominately expressed on a subset of activated CD4+ T cells enriched for transcriptionally active HIV after long-term ART

Adhesion Molecules Associated with Female Genital Tract Infection

Altres ajuts: Marie Curie Career Integration Grant i una beca Fundació Dexeus Salut de la DonaEfforts to develop vaccines that can elicit mucosal immune responses in the female genital tract against sexually transmitted infections have been hampered by an inability to measure immune responses in these tissues. The differential expression of adhesion molecules is known to confer site-dependent homing of circulating effector T cells to mucosal tissues. Specific homing molecules have been defined that can be measured in blood as surrogate markers of local immunity (e.g. α4β7 for gut). Here we analyzed the expression pattern of adhesion molecules by circulating effector T cells following mucosal infection of the female genital tract in mice and during a symptomatic episode of vaginosis in women. While CCR2, CCR5, CXCR6 and CD11c were preferentially expressed in a mouse model of Chlamydia infection, only CCR5 and CD11c were clearly expressed by effector T cells during bacterial vaginosis in women. Other homing molecules previously suggested as required for homing to the genital mucosa such as α4β1 and α4β7 were also differentially expressed in these patients. However, CD11c expression, an integrin chain rarely analyzed in the context of T cell immunity, was the most consistently elevated in all activated effector CD8+ T cell subsets analyzed. This molecule was also induced after systemic infection in mice, suggesting that CD11c is not exclusive of genital tract infection. Still, its increase in response to genital tract disorders may represent a novel surrogate marker of mucosal immunity in women, and warrants further exploration for diagnostic and therapeutic purposes

Localized Populations of CD8low/− MHC Class I Tetramer+ SIV-Specific T Cells in Lymphoid Follicles and Genital Epithelium

CD8 T cells play an important role in controlling viral infections. We investigated the in situ localization of simian immunodeficiency virus (SIV)-specific T cells in lymph and genital tissues from SIV-infected macaques using MHC-class I tetramers. The majority of tetramer-binding cells localized in T cell zones and were CD8+. Curiously, small subpopulations of tetramer-binding cells that had little to no surface CD8 were detected in situ both early and late post-infection, and in both vaginally and rectally inoculated macaques. These tetramer+CD8low/− cells were more often localized in apparent B cell follicles relative to T cell zones and more often found near or within the genital epithelium than the submucosa. Cells analyzed by flow cytometry showed similar populations of cells. Further immunohistological characterization revealed small populations of tetramer+CD20− cells inside B cell follicles and that tetramer+ cells did not stain with γδ-TCR nor CD4 antibodies. Negative control tetramer staining indicated that tetramer+CD8low/− cells were not likely NK cells non-specifically binding to MHC tetramers. These findings have important implications for SIV-specific and other antigen-specific T cell function in these specific tissue locations, and suggest a model in which antigen-specific CD8+ T cells down modulate CD8 upon entering B cell follicles or the epithelial layer of tissues, or alternatively a model in which only antigen-specific CD8 T cells that down-modulate CD8 can enter B cell follicles or the epithelium

Therapeutic DNA vaccine induces broad T cell responses in the gut and sustained protection from viral rebound and AIDS in SIV-infected rhesus macaques.

Immunotherapies that induce durable immune control of chronic HIV infection may eliminate the need for life-long dependence on drugs. We investigated a DNA vaccine formulated with a novel genetic adjuvant that stimulates immune responses in the blood and gut for the ability to improve therapy in rhesus macaques chronically infected with SIV. Using the SIV-macaque model for AIDS, we show that epidermal co-delivery of plasmids expressing SIV Gag, RT, Nef and Env, and the mucosal adjuvant, heat-labile E. coli enterotoxin (LT), during antiretroviral therapy (ART) induced a substantial 2-4-log fold reduction in mean virus burden in both the gut and blood when compared to unvaccinated controls and provided durable protection from viral rebound and disease progression after the drug was discontinued. This effect was associated with significant increases in IFN-γ T cell responses in both the blood and gut and SIV-specific CD8+ T cells with dual TNF-α and cytolytic effector functions in the blood. Importantly, a broader specificity in the T cell response seen in the gut, but not the blood, significantly correlated with a reduction in virus production in mucosal tissues and a lower virus burden in plasma. We conclude that immunizing with vaccines that induce immune responses in mucosal gut tissue could reduce residual viral reservoirs during drug therapy and improve long-term treatment of HIV infection in humans

HCC risk stratification after cure of hepatitis C in patients with compensated advanced chronic liver disease

Background&Aims: Hepatocellular carcinoma (HCC) is a main cause of morbidity and mortality in patients with advanced chronic liver disease (ACLD) due to chronic hepatitis C and who have achieved sustained virologic response (SVR). We elaborated risk stratification algorithms for de-novo-HCC-development after SVR and validated them in an independent cohort. Methods: Derivation cohort: 527 patients with pre-treatment ACLD and SVR to interferon-free therapy were evaluated for de-novo-HCC-development. Among others, alpha-fetoprotein (AFP) and non-invasive surrogates of portal hypertension including liver stiffness measurement (LSM) were assessed pre-/post-treatment. Validation cohort: 1500 patients with compensated ACLD (cACLD) from other European centers. Results: During a median follow-up (FU) of 41 months, 22/475 cACLD (4.6%) (1.45/100patient-years)vs.12/52 decompensated patients (23.1%, 7.00/100patient-years, p<0.001) developed de-novo-HCC. Since decompensated patients were at substantial HCC-risk, we focused on cACLD for all further analyses. In cACLD, post-treatment-values showed a higher discriminative ability for patients with/without de-novo-HCC-development during FU than pre-treatment-values or absolute/relative changes. Models based on post-treatment AFP≥4.6ngxmL-1-3points, alcohol consumption (males:>30g/d/females:>20g/d)-2points (optional), age≥59year-2points, LSM≥19.0kPa-1point, and albumin<42gxL-1-1point, accurately predicted de-novo-HCC-development (bootstrapped Harrel’s C with and without considering alcohol:0.893 and 0.836). Importantly, these parameters also provided independent prognostic information in competing risk analysis and accurately stratified patients into low-(0-3points; ≈2/3 of patients) and high-risk (≥4points; ≈1/3) groups in the derivation (algorithm with alcohol consumption; 4-year HCC-risk:0%vs.16.5%) and validation (3.3%/17.5%) cohorts. An alternative approach based on age/alcohol (optional)/FU-LSM/FU-albumin (i.e., without FU-AFP) also showed a robust performance. Conclusions: Simple algorithms based on post-treatment age/albumin/LSM, and optionally, AFP and alcohol, accurately stratified de-novo-HCC-risk in cACLD patients with SVR. Approximately 2/3 were identified as having an HCC-risk <1%/y in both the derivation and validation cohort, thereby clearly falling below the cost-effectiveness threshold for HCC-surveillance. LAY SUMMARY: Simple algorithms based on age, alcohol consumption, results of blood tests (albumin and α-fetoprotein), as well as liver stiffness measurement after the end of hepatitis C treatment identify a large proportion (approximately 2/3) of patients with advanced but still asymptomatic liver disease who are at very low risk (<1%/year) of liver cancer development, and thus, might not need to undergo 6-monthly liver ultrasound