RESUMO
BACKGROUND: We investigated, for the first time, levels of compliance with faecal calprotectin test in inflammatory bowel disease patients. METHODS: All consecutive adult inflammatory bowel disease patients having been prescribed an faecal calprotectin test between December 2014-July 2015 were included. At their next visit to the hospital, patients had to return a stool sample for the faecal calprotectin test and answer a simple questionnaire: 'Have you brought a stool sample? If not, why not? If so, did you encounter any difficulties when collecting the sample? Were you aware of faecal calprotectin before being asked to take the test?'. RESULTS: One hundred and one patients were included (50 men; 77 patients with Crohn's disease). The range age was 40 years (19-68). Eighty-nine patients were being treated with infliximab, 10 were on vedolizumab, and two were not being treated with a biologic. Thirty-seven patients (35%) had performed the faecal calprotectin test. Eighty-one patients (80%) had not been aware of faecal calprotectin before being asked to take the test. Of the 64 patients who did not take the test, the prime reasons for non-compliance were forgetfulness (n = 49, 76.6%), a lack of perceived benefit for the test (n = 7, 11%), constipation (n = 5, 7.8%), refusal to handle faeces (n = 2, 3.1%), and difficulty collecting the stool sample (n = 1, 1.5%). CONCLUSION: Only one-third of the patients performed the faecal calprotectin test. The main reason for non-compliance was forgetfulness. Our present results emphasise the need for better patient education on the importance of complying with faecal calprotectin testing and the future of faecal calprotectin testing at home.
RESUMO
Zinc isotopic fractionation during adsorption onto a purified humic acid (PHA), an analogue of organic matter (OM), has been investigated experimentally as a function of pH. The Donnan Membrane device (DM) was used to separate Zn bound to the PHA from free Zn2+ ions in solution and allowed us to measure the isotopic ratios of free Zn2+. Below pH 6, adsorption of Zn on the PHA resulted in no measurable isotopic fractionation, while at higher pH, Zn bound to PHA was heavier than free Zn2+ (delta66Zn(PHA-FreeZn2+) = +0.24 per thousand +/- 0.06 2sigma, n = 4). This can be explained by changes in Zn speciation with pH, with higher complexation constants and shorter bond lengths for Zn-PHA complex compared to the free Zn2+. Complexation of Zn with PHA occurred mostly through binding to high affinity sites (HAS) and low affinity sites (LAS). Fractionation factors for 66Zn/64Zn ratios determined by mass balance calculations were equal to 1.0004 for HAS (alpha(HAS-solution)) and 1.000 for LAS (alpha(LAS-soultion)). delta66Zn(OM-FreeZn2+) should then vary according to the heterogeneous nature of the OM, because of the variable relative proportions of these two types of sites. The NICA-Donnan model, along with these fractionation factors and measured delta66Zn(TotalDissolved), was used to simulate the corresponding isotopic composition of free Zn2+ in the Seine River, France: delta66Zn(TotalDissolved-FreeZn2+) varied from +0.02 per thousand to +0.18 per thousand, depending on the HAS/LAS ratio assumed for the OM. This study allows a better understanding of Zn isotope fractionation mechanisms associated with organic mater binding.