The proinflammatory cytokines IL-8 and IL-1beta are elevated in esophagitis and Barrett's epithelium, and markedly elevated in adenocarcinoma. NF-kappaB activation is infrequent in esophagitis, but is increased in Barrett's epithelium and adenocarcinoma. The association of NF-kappaB activation with cytokine upregulation was only evident in patients with adenocarcinoma. These patterns may play an important role in Barrett's inflammation and tumourigenesis, and inhibition of the NF-kappaB/proinflammatory cytokine pathway may be an important target for future chemoprevention strategies.
The gram-negative bacterium Helicobacter pylori (H. pylori) causes chronic gastritis, gastric and duodenal ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Treatment is recommended in all symptomatic patients. The current treatment options for H. pylori infection are outlined in this review in light of the recent challenges in eradication success, largely due to the rapid emergence of antibiotic resistant strains of H. pylori. Antibiotic resistance is a constantly evolving process and numerous studies have shown that the prevalence of H. pylori antibiotic resistance varies significantly from country to country, and even between regions within the same country. In addition, recent data has shown that previous antibiotic use is associated with harbouring antibiotic resistant H. pylori. Local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy. Antimicrobial resistance is assessed by H. pylori culture and antimicrobial susceptibility testing. Recently developed molecular tests offer an attractive alternative to culture and allow for the rapid molecular genetic identification of H. pylori and resistance-associated mutations directly from biopsy samples or bacterial culture material. Accumulating evidence indicates that surveillance of antimicrobial resistance by susceptibility testing is feasible and necessary to inform clinicians in their choice of therapy for management of H. pylori infection.
Background: Vitamin D (vitD) supplementation may prolong remission in Crohn's disease (CD); however, the clinical efficacy and mechanisms are unclear. Aim: To determine changes in intestinal permeability (IP), antimicrobial peptide (AMP) concentrations and disease markers in CD, in response to vitD supplementation. Methods: In a double-blind randomised placebo-controlled study, we assigned 27 CD patients in remission to 2000 IU/day vitD or placebo for 3 mos. We determined IP, plasma cathelicidin (LL-37 in ng/mL), human-beta-defensin-2 (hBD2 in pg/mL), disease activity (Crohn's Disease Activity Index (CDAI)), C-reactive protein (CRP in mg/L), fecal calprotectin (mg/g), Quality of Life (QoL) and serum 25-hydroxyvitamin D (25(OH)D in nmol/L) at 0 and 3 mos. Results: At 3 mos., 25(OH)D concentrations were significantly higher in those whom were treated (p < 0.001). Intra-group analysis showed increased LL-37 concentrations (p ¼ 0.050) and maintenance of IP measures in the treated group. In contrast, in the placebo group, the small bowel (p ¼ 0.018) and gastro-duodenal permeability (p ¼ 0.030) increased from baseline. At 3 mos., patients with 25(OH)D 75 nmol/L had significantly lower CRP (p ¼ 0.019), higher QoL (p ¼ 0.037), higher LL-37 concentrations (p < 0.001) and non-significantly lower CDAI scores (p ¼ 0.082), compared to those with levels <75 nmol/L. Conclusion: Short-term treatment with 2000 IU/day vitD significantly increased 25(OH)D levels in CD patients in remission and it was associated with increased LL-37 concentrations and maintenance of IP. Achieving 25(OH)D 75 nmol/l was accompanied by higher circulating LL-37, higher QoL scores and reduced CRP. Registered at ClinicalTrials.gov (NCT01792388).
The innate immune system is equipped with pattern-recognition receptors that recognize pathogen-associated molecular patterns 1 . Pattern-recognition receptors include transmembrane Toll-like receptors (TLRs) and cytosolic Nod-like receptors 2 . Nod1 and Nod2 recognize structures in bacterial peptidoglycan 3 . Loss-of-function mutants of Nod2 are associated with Crohn's disease 4-6 , whereas gain-offunction mutants result in predisposition to the development of earlyonset sarcoidosis and Blau syndrome 7,8 . Nod2 responds to muramyl dipeptide (MDP), a derivative of peptidoglycan 9,10 . Nod2 consists of two amino-terminal caspase-recruitment domains (CARDs), a central self-oligomerization NACHT region and multiple carboxyterminal leucine-rich repeats 11 . Engagement of the leucine-rich repeats by MDP promotes a conformational change that exposes the NACHT domain, which allows self-oligomerization of Nod2 and the binding of its CARDs to the CARD-containing kinase RIP2 (refs. 12,13). RIP2 interacts with the kinase TAK1, which leads to activation of the transcription factor NF-κB and mitogen-activated protein kinases (MAPKs) and induction of the expression of proinflammatory cytokines [14][15][16][17][18] . Ubiquitination of RIP2 is critical for Nod2 signaling pathways 15,16 .The attachment of polyubiquitin chains to RIP2 serves to recruit TAK1 via the adaptors TAB2 and TAB3 (ref. 19), and that facilitates TAK1-induced phosphorylation and activation of IκB kinases (IKKs) that induce phosphorylation of inhibitory IκB proteins 20 . Phosphorylated IκB proteins undergo proteasome-mediated degradation 21 that allows NF-κB to translocate to the nucleus and induce proinflammatory gene expression 22 . Studies have investigated the enzymes responsible for catalyzing the ubiquitination of RIP2. The Ubc13-Uev1a dimer acts as the E2 conjugating enzyme in the Lys63 (K63)-linked polyubiquitination of RIP2 (refs. 15,16), but the identity of the E3 ubiquitin ligase(s) that directly ubiquitinate(s) RIP2 to mediate Nod2-induced activation of NF-κB remains unclear. TRAF6 has been proposed as the main E3 ligase for RIP2 (ref. 15), but the ubiquitination of RIP2 is intact in TRAF6-deficient cells 16 and knockdown of TRAF6 does not affect RIP2-mediated activation of NF-κB 9,14 . Three members of the 'IAP' family of E3 ubiquitin ligases (XIAP, cIAP1 and cIAP2) have been proposed to regulate RIP2 ubiquitination 23,24 . Although the conclusions of the last two studies differ about the functional importance of cIAP1 and cIAP2 in mediating Nod2-induced ubiquitination of RIP2, one demonstrated that XIAP promotes the ubiquitination of RIP2 and recruitment of the linear ubiquitin chain-assembly complex (LUBAC) to Nod2 (ref. 23). However, the XIAP-mediated polyubiquitination of RIP2 is not K63 linked, a type of linkage associated with RIP2-induced activation of NF-κB. The E3 ligase Itch can also directly ubiquitinate RIP2 to negatively regulate Nod2-induced activation of NF-κB 25 . Thus, it remains unclear which E3 ubiquitin ligase directly cataly...
It is accepted that the success of Helicobacter pylori eradication treatment using standard triple therapy is declining. Resistance, particularly to clarithromycin, has been shown in numerous countries to be rising to a level where the use of standard triple therapy in its current form may no longer be justified. The two major factors influencing resistance are prior exposure to the antibiotic and compliance with therapy. Regimes based on bismuth and levofloxacin, which had previously been mainly second‐line options, are now emerging as superior first‐line options. Trials of sequential and concomitant therapies are also showing the usefulness of these treatments in different populations. Options for third and subsequent line therapies include furazolidone and rifabutin‐based regimes. Susceptibility testing should be performed to maintain accurate data on resistance levels, and has also clinical utility in difficult to eradicate cases. None of these, however, will be successful unless compliance is improved upon. If compliance is assured and eradication confirmation pursued, it has been repeatedly illustrated that near full eradication is achievable.
Circulating 25OHD was significantly inversely associated with intestinal inflammation as determined by FC in CD. Subgroup analysis confirmed the association among those in clinical remission, but not in those with active disease. 25OHD was not associated with disease activity score (CDAI) or systemic inflammation (CRP). Vitamin D intervention studies are warranted to determine whether raising serum 25OHD levels in patients with CD may reduce intestinal inflammation as measured by FC.
SBA occurs in elderly patients with cardiovascular disease and CKD, as previously suggested. This study identifies a previously unrecognised risk in females, patients with chronic respiratory conditions and VTE, and the use of warfarin and asasantin retard. These associations should raise awareness of possible underlying SBA in risk patients with anemia.
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