Immune response to PSV-23 is impaired in Crohn's disease (CD) patients on combination immunosuppressive therapy but is normal among non-immunosuppressed patients. Given the unpredictable likelihood for immunosuppressive therapy, newly diagnosed patients with IBD should undergo vaccination before the initiation of immunosuppressive therapy.

Bowel preparation is a core issue in colonoscopy, as it is closely related to the quality of the procedure. Patients often find that bowel preparation is the most unpleasant part of the examination. It is widely accepted that the quality of cleansing must be excellent to facilitate detecting neoplastic lesions. In spite of its importance and potential implications, until recently, bowel preparation has not been the subject of much study. The most commonly used agents are high-volume polyethylene glycol (PEG) electrolyte solution and sodium phosphate. There has been some confusion, even in published meta-analyses, regarding which of the two agents provides better cleansing. It is clear now that both PEG and sodium phosphate are effective when administered with proper timing. Consequently, the timing of administration is recognized as one of the central factors to the quality of cleansing. The bowel preparation agent should be administered, at least in part, a few hours in advance of the colonoscopy. Several low volume agents are available, and either new or modified schedules with PEG that usually improve tolerance. Certain adjuvants can also be used to reduce the volume of PEG, or to improve the efficacy of other agents. Other factors apart from the choice of agent can improve the quality of bowel cleansing. For instance, the effect of diet before colonoscopy has not been completely clarified, but an exclusively liquid diet is probably not required, and a low-fiber diet may be preferable because it improves patient satisfaction and the quality of the procedure. Some patients, such as diabetics and persons with heart or kidney disease, require modified procedures and certain precautions. Bowel preparation for pediatric patients is also reviewed here. In such cases, PEG remains the most commonly used agent. As detecting neoplasia is not the main objective with these patients, less intensive preparation may suffice. Special considerations must be made for patients with inflammatory bowel disease, including safety and diagnostic issues, so that the most adequate agent is chosen. Identifying neoplasia is one of the main objectives of colonoscopy with these patients, and the target lesions are often almost invisible with white light endoscopy. Therefore excellent quality preparation is required to find these lesions and to apply advanced methods such as chromoendoscopy. Bowel preparation for patients with lower gastrointestinal bleeding represents a challenge, and the strategies available are also reviewed here. Core tip: Bowel preparation for colonoscopy is a central issue related to the quality of the procedure. There are different agents for bowel preparation that can be administered with different schedules. We review the most commonly used agents, as well as new agents and combinations. Moreover, certain considerations should be taken into account for special populations in order to improve safety, efficacy and tolerance. Regimens for bowel preparation in special situations are discussed, such as for pedi...

Biallelic loss-of-function (LOF) mutations of the NCF4 gene, encoding the p40 phox subunit of the phagocyte NADPH oxidase, have been described in only 1 patient. We report on 24 p40 phox -deficient patients from 12 additional families in 8 countries. These patients display 8 different in-frame or out-of-frame mutations of NCF4 that are homozygous in 11 of the families and compound heterozygous in another. When overexpressed in NB4 neutrophil-like cells and EBV-transformed B cells in vitro, the mutant alleles were found to be LOF, with the exception of the p.R58C and c.120_134del alleles, which were hypomorphic. Particle-induced NADPH oxidase activity was severely impaired in the patients' neutrophils, whereas PMAinduced dihydrorhodamine-1,2,3 (DHR) oxidation, which is widely used as a diagnostic test for chronic granulomatous disease (CGD), was normal or mildly impaired in the patients. Moreover, the NADPH oxidase activity of EBV-transformed B cells was also severely impaired, whereas that of mononuclear phagocytes was normal. Finally, the killing of Candida albicans and Aspergillus fumigatus hyphae by neutrophils was conserved in these patients, unlike in patients with CGD. The patients suffer from hyperinflammation and peripheral infections, but they do not have any of the invasive bacterial or fungal infections seen in CGD. Inherited p40 phox deficiency underlies a distinctive condition, resembling a mild, atypical form of CGD. phox -deficient patient is compound heterozygous for a premature stop codon and a missense mutation in the PX domain that compromises binding to PI(3)P, which results in the impairment of neutrophil phagocytosis-induced oxidase activity (26). As in classic CGD neutrophils, intracellular oxidant production after stimulation with serum-opsonized zymosan (SOZ), IgG beads, or serumopsonized Staphylococcus aureus is impaired in the patient's neutrophils, and S. aureus killing is also defective (20,26,30). However, in this patient, unlike in classic CGD patients, the production of O 2 -by neutrophils in response to stimulation with PMA or formyl-methionyl-leucyl-phenylalanine (fMLF) is normal (26). The killing of S. aureus by neutrophils is also impaired in p40 phox deficiency and classic CGD are largely unknown. Here, we describe the characteristics of 24 patients from 12 families in 8 countries with biallelic mutations of NCF4. The Journal of Clinical Investigation R E S E A R C H A R T I C L E

SUMMARY Background

IBD has continued to increase in the study cohort, slowly approaching the level reported in developed countries.

The incidence and prevalence of inflammatory bowel disease (IBD) has increased in recent years in several Latin American countries. There is a need to raise awareness in gastroenterologists and the population in general, so that early diagnosis and treatment of ulcerative colitis (UC) and Crohn's Disease (CD) can be carried out. It is important for all physicians to have homogeneous criteria regarding the diagnosis and treatment of IBD in Latin America. The Pan American Crohn's and Colitis Organisation (PANCCO) is an organization that aims to include all the countries of the Americas, but it specifically concentrates on Latin America. The present Consensus was divided into two parts for publication: 1) Diagnosis and treatment and 2) Special situations. This is the first Latin American Consensus whose purpose is to promote a perspective adapted to our Latin American countries for the diagnosis, treatment, and monitoring of patients with UC and CD.

Losartan does not seem to influence liver injury and fibrogenic events in the CDD model of NASH.

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