High thiopurine metabolite concentrations associated with lymphopenia in inflammatory bowel disease (IBD) pediatric patients receiving aminosalicylates combined with azathioprine.

OBJECTIVE: Aminosalicylates are widely used with azathioprine in the treatment of IBD. The association results in an increase in 6-TGN levels in adults with IBD with a difference in the occurrence of myelotoxic effects. Scarce data are available in pediatric population. We proposed to investigate the effect of the coadministration of aminosalicylates on thiopurine concentrations in pediatric IBD patients. MATERIALS AND METHODS: Data from 71 patients treated for at least 1 y by azathioprine and aminosalicylates were recorded. 6-TGN and 6-MeMPN concentrations, blood cell counts and liver function tests were compared between patients taking and those not taking aminosalicylates. RESULTS: Aminosalicylate therapy was associated with a significant increase in mean 6-TGN but also 6-MeMPN concentrations. In patients in remission, 6-TGN level was related to aminosalicylate dosage (r = 0.561, p = 0.010). Lymphopenia rate was higher in patients receiving combined therapy compared to monotherapy whereas a slight rise in leucopenia was found. CONCLUSIONS: This observation suggests that the higher frequency of lymphopenia may be associated with the elevated 6-TGN concentrations recovered in patients treated with aminosalicylates. This combination does not improve remission rate but could increase adverse effects especially lymphopenia.

The role of macroscopic sputum quality assessments to optimise sputum testing for tuberculosis.

SETTING: Community-wide active case finding for tuberculosis (TB) using Xpert® MTB/RIF as the primary screening tool, Ca Mau Province, Viet Nam. OBJECTIVES: To determine whether macroscopic sputum quality characteristics (sputum colour and volume) can be used to predict Xpert MTB-negative sputum and hence exclude sputum samples from testing. DESIGN: Field staff conducted household visits to approximately 51,200 adults in 58 villages randomly selected from throughout the province. Sputum samples from all screened participants who were able to produce ⩾1 ml sputum underwent macroscopic sputum assessment and were tested with Xpert. RESULTS: Of the 21,624 sputum samples tested, 159 (0.74%) were Xpert MTB-positive; 93% of the samples were 1-2 ml and nearly all were mucoid (93%) or mucopurulent (5.7%). One salivary sample was Xpert MTB-positive (2.0% of all salivary samples). The lowest positive predictive value for any sputum volume or colour characteristic was 0.66%. This was not substantially different from the overall prevalence of positive sputum Xpert MTB (0.74%). CONCLUSION: Sputum colour and volume cannot be used to predict the presence or absence of M. tuberculosis in sputum detected using Xpert. These sputum quality parameters cannot therefore be used to exclude sputum samples from testing for TB.

Novel oral phosphate binder with nanocrystalline maghemite-phosphate binding capacity and pH effect.

Hyperphosphatemia is one of the main risk factors contributing to morbidity and mortality in patients with end stage renal disease. The demand for a new phosphate binder is continuously increasing since the number of patients suffering under hyperphosphatemia is growing. However, side effects and high pill burden of currently available phosphate binders are the main reasons for low compliance and uncontrolled serum phosphate levels. Therefore, the aim of this study was to develop a novel phosphate binder with a high phosphate binding capacity over the entire gastrointestinal (GI) pH range. This novel phosphate binder C-PAM-10 is based on d-mannose coated nanocrystalline maghemite and belongs to the new class of phosphate binders, called the "iron based agents". It was possible to obtain a phosphate binding product that showed very high phosphate binding capacities with the characteristic of being pH independent at relevant pH ranges. The simulation of a GI passage ranging from pH 1.2 to pH 7.5 showed a 2.5 times higher phosphate binding capacity compared to the commonly used phosphate binder sevelamer carbonate. The simulation of a pH sensitive coating that releases the iron based phosphate binder at pH values ≥4.5 still showed a very high phosphate binding capacity combined with very low iron release which might decrease iron related side effects in vivo. Therefore, C-PAM-10 and its variations may be very promising candidates as a superior phosphate binder.

Phytoplankton distribution and productivity in a highly turbid, tropical coastal system (Bach Dang Estuary, Vietnam).

Phytoplankton diversity, primary and bacterial production, nutrients and metallic contaminants were measured during the wet season (July) and dry season (March) in the Bach Dang Estuary, a sub-estuary of the Red River system, Northern Vietnam. Using canonical correspondence analysis we show that phytoplankton community structure is potentially influenced by both organometallic species (Hg and Sn) and inorganic metal (Hg) concentrations. During March, dissolved methylmercury and inorganic mercury were important factors for determining phytoplankton community composition at most of the stations. In contrast, during July, low salinity phytoplankton community composition was associated with particulate methylmercury concentrations, whereas phytoplankton community composition in the higher salinity stations was more related to dissolved inorganic mercury and dissolved mono and tributyltin concentrations. These results highlight the importance of taking into account factors other than light and nutrients, such as eco-toxic heavy metals, in understanding phytoplankton diversity and activity in estuarine ecosystems.