The effect of three years of TNF alpha blocking therapy on markers of bone turnover and their predictive value for treatment discontinuation in patients with ankylosing spondylitis: a prospective longitudinal observational cohort study

Introduction

Statins (hydroxymethylglutaryl coenzyme A reductase inhibitors) are effective in reducing the risk of cardiovascular morbidity and mortality in patients with hyperlipidemia, hypertension, or type II diabetes. Next to their cholesterol-lowering activity, statins have immunomodulatory properties. Based on these properties, we hypothesized that statin use may eventually lead to dysregulation of immune responses, possibly resulting in autoimmunity. We have recently shown in an observational study that statin use was associated with an increased risk of developing rheumatoid arthritis. Our objective was to investigate whether a causal relationship could be established for this finding.

Methods

The mouse collagen type II (CII)-induced arthritis (CIA) model was used, with immunization, challenge, and euthanasia at days 0, 21, and 42, respectively. Statins were given orally before (day -28 until day 21) or after (day 21 until day 42) CIA induction. Atorvastatin (0.2 mg/day) or pravastatin (0.8 mg/day) was administered. Arthritis was recorded three times a week. Serum anti-CII autoantibodies and cytokines in supernatants from Concanavalin-A-stimulated lymph node cells and CII-stimulated spleen cells were measured.

Results

Statin administration accelerated arthritis onset and resulted in 100% arthritic animals, whereas only seven out of 12 nonstatin control animals developed arthritis. Atorvastatin administration after CIA induction resulted in earlier onset than atorvastatin administration before induction, or than pravastatin administration before or after induction. The arthritic score of animals given pravastatin before CIA induction was similar to that of the nonstatin controls, whereas the other groups that received statins showed higher arthritic scores. Atorvastatin administration, especially before CIA induction, increased anti-CII autoantibody production. IL-2 and IL-17 production by lymph node and spleen cells was higher in CIA animals than in PBS controls, but was not affected by statin administration. While IFN?? production was not affected by CIA induction, atorvastatin administration before CIA induction increased the production of this cytokine.

Conclusion

These data support previous results from our observational studies, indicating a role for statins in the induction of autoimmunity.     

alpha,beta-Dehydrophenylalanine choline esters, a new class of reversible inhibitors of human acetylcholinesterase and butyrylcholinesterase

Our goal was to design, synthesize, and evaluate new cholinesterase inhibitors. Fourteen dehydroamino acids esterified to choline and to its ternary analog were synthesized by a new method that gave a yield of 84-93%. The potency of the amino acid ester derivatives was tested by measuring K(i) values for inhibition of human red cell acetylcholinesterase and human plasma butyrylcholinesterase. The most potent compound was a choline ester of dehydrophenylalanine where the amine group of the amino acid was derivatized with a benzoyl group containing a methoxy in the 2-position, CH(3)O(C(6)H(4))CONHC(CHC(6)H(5))COOCH(2)CH(2)N(+)(CH(3))(3). This compound was a strong inhibitor of both human acetylcholinesterase and human butyrylcholinesterase, with K(i) values of 10 microM and 0.08 microM, respectively. These K(i) values are comparable to that of Rivastigmine. Docking of the most potent compound into the active site of human butyrylcholinesterase showed that the lowest energy model had two benzene rings oriented towards Trp 82 and Tyr 332 whereas the positively charged nitrogen group was stabilized by Trp 231. This orientation placed the ester group 3.89 A from the active site Ser 198, a distance too far for covalent bonding, explaining why the esters are inhibitors rather than substrates. This class of anticholinesterase agents has the potential for therapeutic utility in the treatment of disorders of the cholinergic system.     

Hepatic macrophage iron aggravates experimental alcoholic steatohepatitis

One prime feature of alcoholic liver disease (ALD) is iron accumulation in hepatic macrophages/Kupffer cells (KC) associated with enhanced NF-kappaB activation. Our recent work demonstrates a peroxynitrite-mediated transient rise in intracellular labile iron (ILI) as novel signaling for endotoxin-induced IKK and NF-kappaB activation in rodent KC. The present study investigated the mechanism of KC iron accumulation and its effects on ILI response in experimental ALD. We also tested ILI response in human blood monocytes. Chronic alcohol feeding in rats results in increased expression of transferrin (Tf) receptor-1 and hemochromatosis gene (HFE), enhanced iron uptake, an increase in nonheme iron content, and accentuated ILI response for NF-kappaB activation in KC. Ex vivo treatment of these KC with an iron chelator abrogates the increment of iron content, ILI response, and NF-kappaB activation. The ILI response is evident in macrophages derived from human blood monocytes by PMA treatment but not in vehicle-treated monocytes, and this differentiation-associated phenomenon is essential for maximal TNF-alpha release. PMA-induced macrophages load iron dextran and enhance ILI response and TNF-alpha release. These effects are reproduced in KC selectively loaded in vivo with iron dextran in mice and more importantly aggravate experimental ALD. Our results suggest enhanced iron uptake as a mechanism of KC iron loading in ALD and demonstrate the ILI response as a function acquired by differentiated macrophages in humans and as a priming mechanism for ALD.     

Nisin inducible production of listeriolysin O in <Emphasis Type="Italic">Lactococcus lactis</Emphasis> NZ9000

Background  

Listeria monocytogenesis a well-characterized food-borne pathogen that infects pregnant women and immunocompromised individuals. Listeriolysin O (LLO) is the major virulence factor of the pathogen and is often used as a diagnostic marker for detection of L. monocytogenes. In addition, LLO represents a potent antigen driving T cell-mediated immunity during infection. In the present work, Lactococcus lactisNZ9000 was used as an expression host to hyper-produce LLO under inducible conditions using the NICE (NIsin Controlled Expression) system. We created a modified pNZ8048 vector encoding a six-His-tagged LLO downstream of the strong inducible PnisA promoter.     

Seed morphology,presence of areoles and water entry at imbibition of <i>Vicia dasycarpa</i> Ten. cv. Tolse F.C.A

The morphological characteristics of the seeds of Vicia dasycarpa Ten. cv. Tolse FCA were studied in relation to the area of imbibition water entry and were considered the presence of areoles. Seeds were analyzed using a stereo, optical and scanning electron microscope (SEM). The determination of the initial water entry area was carried out by immersing the seeds in a solution of tetrazolium (1%). This study showed that this species has seeds with a halo framing the hilum, an inconspicuous dry aril and a deltoid micropyle. The seedcoat pattern is papillose. The tracheid bar is surrounded by a ring of parenchymatous cells, and the tracheids show slight warty and non-vestured pits. It was confirmed the presence of an endospermic radicle pocket that surrounds and protect the radical tip. Two pairs of cotyledonar areoles were identified. It was established that the entry of water during imbibition starts in the area of the lens -having cracks- and moves in the sagittal plane. Both citological characteristic of tracheid bar and areoles presence show an apomorfous state between the Papiplionoids.     

A simple method for studying whole sections of rice grain

We developed a new and simple method to collect sections of a whole brown rice kernel for investigation of histological properties. A single kernel of rice was dehydrated through a graded ethanol series, transferred to xylene, and embedded in paraffin. During sectioning of the blocks using a rotary microtome, we used a special adhesive tape to collect and place the sections on slides so they remained flat. The use of the adhesive tape technique combined with autofluorescence characteristics allowed us to visualize cell walls throughout an entire longitudinal or transverse section of a whole rice kernel. We obtained scanning electron microscopy images of the sections to determine section quality.     

Staphylococcus aureus and Wegener's granulomatosis

Wegener's granulomatosis (WG) is a form of systemic vasculitis. It is characterized by granulomatous inflammation in the upper and lower airways, vasculitis and necrotizing glomerulonephritis, and is strongly associated with antineutrophil cytoplasmic antibodies against proteinase 3. Since the etiology of the disease is not clear, treatment, consisting of corticosteroids and immunosuppressives, is nonspecific and associated with severe side effects. Pinpointing the trigger(s) of the disease would highly improve treatment. Clinical evidence shows that an infectious agent, the bacterium Staphylococcus aureus, is a risk factor for disease relapse, suggesting its involvement in the pathogenesis of WG. Here we review both clinical and experimental data that either indicate or support a role for S. aureus in WG.     

Autoantibodies directed to novel components of the PM/Scl complex, the human exosome

The autoantigenic polymyositis/scleroderma (PM/Scl) complex was recently shown to be the human homologue of the yeast exosome, which is an RNA-processing complex. Our aim was to assess whether, in addition to targeting the known autoantigens PM/Scl-100 and PM/Scl-75, autoantibodies also target recently identified components of the PM/Scl complex. The prevalence of autoantibodies directed to six novel human exosome components (hRrp4p, hRrp40p, hRrp41p, hRrp42p, hRrp46p, hCsl4p) was determined in sera from patients with idiopathic inflammatory myopathy (n = 48), scleroderma (n = 11), or the PM/Scl overlap syndrome (n = 10). The sera were analyzed by enzyme-linked immunosorbent assays and western blotting using the affinity-purified recombinant proteins. Our results show that each human exosome component is recognized by autoantibodies. The hRrp4p and hRrp42p components were most frequently targeted. The presence of autoantibodies directed to the novel components of the human exosome was correlated with the presence of the anti-PM/Scl-100 autoantibody in the sera of patients with idiopathic inflammatory myopathy (IIM), as was previously found for the anti-PM/Scl-75 autoantibody. Other clear associations between autoantibody activities were not found. These results further support the conception that the autoimmune response may initially be directed to PM/Scl-100, whereas intermolecular epitope spreading may have caused the autoantibody response directed to the associated components.     

Polymorphism and divergence at the prune locus in Drosophila melanogaster and D. simulans

The prune locus of Drosophila melanogaster lies at the tip of the X chromosome, in a region of reduced recombination in which nearby loci show reduced variation relative to evolutionary divergence from D. simulans. DNA sequencing of prune alleles from D. melanogaster and D. simulans reveals extremely low variation in D. melanogaster but greater variation in D. simulans. Divergence between the two species is not reduced. This pattern may be explained by either positive selection leading to hitchhiking of neutral variation or background selection against deleterious mutations. The pattern of silent versus replacement polymorphism and divergence at prune is consistent with either a model of weakly deleterious selection against amino acid substitutions or balancing selection.      

Thiamine preserves mitochondrial function in a rat model of traumatic brain injury,preventing inactivation of the 2-oxoglutarate dehydrogenase complex

Background and purpose

Based on the fact that traumatic brain injury is associated with mitochondrial dysfunction we aimed at localization of mitochondrial defect and attempted to correct it by thiamine.