Review article: optimal preparation for surgery in Crohn's disease.

BACKGROUND: One-third of Crohn's disease (CD) patients will undergo abdominal surgery within the first 5 years of diagnosis. AIM: To review the available evidence on pre-operative optimisation of CD patients. METHODS: The literature regarding psychological support, radiological imaging, abdominal abscess management, nutritional support, thromboembolic prophylaxis and immunosuppression in the perioperative setting was reviewed. RESULTS: For diagnosis of fistulas, abscesses and stenosis, ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) have a high diagnostic accuracy. Under either CT or US guidance, it is possible to perform abscess percutaneous drainage (PD), which, with systemic antibiotic therapy, should be the first-line approach to intra-abdominal abscesses. CD patients with weight loss <10% within the last 3-6 months, body mass index < 18.5 kg/m(2) and/or albumin levels <30 g/L, are at an increased risk of post-operative complications. Pre-operative nutritional support should be used in these patients. IBD patients undergoing surgery have a higher risk of venous thromboembolic disease than patients with colorectal cancer, and current guidelines recommend that they should receive prophylaxis with heparin. Whether the use of anti-TNF agents before surgery increases the likelihood of post-operative complications, is the subject of much debate. To date, cumulative evidence from most studies (all retrospective) suggests that there is no such risk increment. Prospective studies are necessary to firmly establish this conclusion. CONCLUSIONS: Preparation for surgery requires close interaction between surgeons, gastroenterologist, radiologists, psychologists and the patient. Correct pre-operative planning of surgical treatment has a major impact on the outcome of such treatment.

Generation of a novel antibody probe to the apical sodium-dependent bile acid transporter that inhibits ileal bile acid absorption.

Intestinal bile acid absorption is mediated by a sodium-dependent transporter located in the brush border apical membrane of ileocytes. The transmembrane topology and the role of individual amino acid residues in the bile acid transport process have been investigated by means of various experimental approaches, leading to multiple hypotheses. We raised a monoclonal antibody against a segment of the transporter comprising vicinal cysteine residues, in order to evaluate its functional role. A 14 amino acid peptide, corresponding to amino acids 104-117 of the transporter, was synthesized, and a monoclonal anti-peptide antibody was raised. In vitro uptake-inhibition studies in the presence of the monoclonal anti-peptide antibody were performed using ileal brush border membrane vesicles. Rabbit ileum was perfused in vivo with 5 mM taurocholic acid in the presence of the monoclonal antibody, and bile acid absorption inhibition was evaluated. The anti-peptide monoclonal antibody significantly reduced the in vitro uptake and in vivo absorption of taurocholic acid. The present data demonstrate the functional relevance of the 104-117 peptide segment and report the generation of a novel antibody against the apical sodium-dependent bile acid transporter (ASBT) that may be used as a therapeutic agent in hypercholesterolemia and in cholestatic pruritus.

Calcium, iron, and zinc uptake from digests of infant formulas by Caco-2 cells.

Our aim was to estimate the bioavailability of calcium, iron, and zinc from infant formulas using a model that includes in vitro digestion and a Caco-2 cell culture to estimate the uptake. The cell culture conditions were selected, and uptake assays were carried out first with calcium, iron, and zinc standard solutions, and then with the soluble fraction of enzymatic digests of an adapted milk-based and a soy-based infant formula. It was not possible to measure the uptake of calcium, iron, and zinc from standard solutions added to the cell cultures in amounts similar to those present in infant formula digests with our method. The fact that it was, however, possible in the case of enzymatic digests suggests the presence of components in the digests that enhance mineral uptake. When mineral uptakes were expressed as percentages of the mineral present, statistically significant differences were found in the case of calcium between the uptake from the milk- and the soy-based formulas. For iron and zinc no such differences were observed.

Effect of proteins, phytates, ascorbic acid and citric acid on dialysability of calcium, iron, zinc and copper in soy-based infant formulas.

The possible effect of ascorbic acid, citric acid, proteins and phytate on dialysability of Ca, Fe, Zn and Cu in soy-based infant formulas is studied, taking dialysability as a measure of the amount of element available for absorption. Different dialysis percentages for similar element contents in different formulas are found. A regression analysis was applied between Ca, Zn, Cu and Fe dialysis percentages and soy-based formula components to estimate the possible influence of the latter on the dialysability of the elements. Significant correlations were found between citric acid contents and dialysability of Zn and Fe. No correlations were found between protein, ascorbic acid and phytic acid contents and the dialysis percentages of the four minerals. However, we must to point out that the range of protein contents was narrow and the ascorbic acid: iron ratio was high in our formulas.