Defining and investigating difficult asthma: Developing quality indicators

SummaryBackgroundThere is no agreed definition of ‘difficult asthma’ or what investigations should be available to investigate these patients. Patients with difficult asthma remain symptomatic on high levels of treatment and are high users of medical resources.AimTo develop a set of quality indicators for the definition and investigation of difficult asthma.MethodModified RAND Appropriateness Method was used. An expert panel composed of nine hospital asthma specialists who run ‘difficult’ asthma clinics and were identified from a shortlist of key workers in the field. Indicators were rated as necessary to define and investigate difficult asthma.ResultsDifficult asthma was defined as ‘symptoms persisting beyond therapy consistent with step 4 of the British Thoracic Society (BTS) guidelines’ (high dose inhaled corticosteroids and long acting β2-agonists). Eighty-three indicators were identified (40 relating to definition and 43 relating to investigations). Of these 32 (39%) were rated as necessary: 7 out of 40 (18%) for defining difficult asthma and 23 out of 43 (53%) for investigations. Indicators of high medical resource usage were characteristic of the ‘difficult’ nature of the management of patient with difficult asthma. A framework for the investigation of these patients was created.ConclusionThe listed performance indicators identify a range of requirements that are necessary to define difficult asthma. Targeting of real needs in this group of patients will lead to better patient care and reduction of ‘waste’ in provision of healthcare

Cylindrospermopsin- and deoxycylindrospermopsin-producing Raphidiopsis raciborskii and microcystin-producing Microcystis spp. in Meiktila lake, Myanmar

Meiktila Lake is a shallow reservoir located close to Meiktila city in central Myanmar. Its waterisusedforirrigation,domesticpurposesanddrinkingwater. Nodetailedstudyofthepresence of cyanobacteria and their potential toxin production has been conducted so far. To ascertain thecyanobacterialcompositionandpresenceofcyanobacterialtoxinsinMeiktilaLake,watersamples were collected in March and November 2017 and investigated for physico-chemical and biological parameters. Phytoplanktoncompositionandbiomassdeterminationrevealedthatmostofthesamples were dominated by the cyanobacterium Raphidiopsis raciborskii. In a polyphasic approach, seven isolated cyanobacterial strains were classified morphologically and phylogenetically as R. raciborskii, and Microcystis spp. and tested for microcystins (MCs), cylindrospermopsins (CYNs), saxitoxins and anatoxins by enzyme-linked immunosorbent assay (ELISA) and liquid chromatography–mass spectrometry (LC–MS). ELISA and LC–MS analyses confirmed CYNs in three of the five Raphidiopsis strains between 1.8 and 9.8 µg mg−1 fresh weight. Both Microcystis strains produced MCs, one strain 52 congeners and the other strain 20 congeners, including 22 previously unreported variants. Due to the presence of CYN- and MC-producing cyanobacteria, harmful effects on humans, domestic and wild animals cannot be excluded in Meiktila Lake

Epimers of azaspiracids: Isolation, structural elucidation, relative LC-MS response, and in vitro toxicity of 37-epi-azaspiracid-1

Since azaspiracid-1 (AZA1) was identified in 1998, the number of AZA analogues has increased to over 30. The development of an LC-MS method using a neutral mobile phase led to the discovery of isomers of AZA1, AZA2, and AZA3, present at 3c2-16% of the parent analogues in phytoplankton and shellfish samples. Under acidic mobile phase conditions, isomers and their parents are not separated. Stability studies showed that these isomers were spontaneous epimerization products whose formation is accelerated with the application of heat. The AZA1 isomer was isolated from contaminated shellfish and identified as 37-epi-AZA1 by nuclear magnetic resonance (NMR) spectroscopy and chemical analyses. Similar analysis indicated that the isomers of AZA2 and AZA3 corresponded to 37-epi-AZA2 and 37-epi-AZA3, respectively. The 37-epimers were found to exist in equilibrium with the parent compounds in solution. 37-epi-AZA1 was quantitated by NMR, and relative molar response studies were performed to determine the potential differences in LC-MS response of AZA1 and 37-epi-AZA1. Toxicological effects were determined using Jurkat T lymphocyte cells as an in vitro cell model. Cytotoxicity experiments employing a metabolically based dye (i.e., MTS) indicated that 37-epi-AZA1 elicited a lethal response that was both concentration- and time-dependent, with EC50 values in the subnanomolar range. On the basis of EC50 comparisons, 37-epi-AZA1 was 5.1-fold more potent than AZA1. This data suggests that the presence of these epimers in seafood products should be considered in the analysis of AZAs for regulatory purposes. \ua9 2014 American Chemical Society.Peer reviewed: YesNRC publication: Ye

Accumulation-depuration potential and natural occurrence of Microcystin-LR toxin in basil

Accumulation of hepatotoxic cyanobacterial toxins, like microcystin-LR (MC-LR), in edible crops through irrigation with contaminated water can result in human health&nbsp;risks. To assess the accumulation and depuration potential of MC-LR in basil under an optimized laboratory condition and to quantify its natural occurrence in basil samples collected from different markets in&nbsp;Belgium. Basil plants in hydroculture were exposed to 5, 10 or 50 µg L-1 MC-LR for 7 days. The depuration process was assessed by transferring plants to uncontaminated Hoagland solution &nbsp;for another 7 days. Moreover, 50 basil products were collected from the Belgian markets. Basil leaves (lab and market) and roots (lab only) were analyzed using a validated UHPLC-MS/MS-based method to quantify MC-LR. ELISA and HRLCMS-techniques were applied to verify MC-LR presence in accumulation and depuration samples.[A3]&nbsp; Concentration dependent accumulation of MC-LR was observed in both basil leaves and roots, reaching for the highest treatment condition up to 87.90 µg kg-1 and 143.80 µg kg-1, respectively. The basil roots accumulated more toxin compared to the leaves. Depuration was observed for all treatment conditions in both roots and leaves. At least six replicates were included and the whole experiment was repeated two times. These results were corroborated by both the ELISA and HRLCMS at the highest treatment condition. Moreover, MC-LR was detected below LOQ (1 µg kg-1) in one market&nbsp;sample. These results show the potential of basil to accumulate MC-LR from irrigation water, potentially resulting in human exposure to high levels of toxin. For the first time in Belgium, MC-LR was also detected in a vegetable from the market, showing human exposure through vegetables is already a&nbsp;reality.</p

Extraction of microalgal toxins by large-scale pumping of seawater in Spain and Norway, and isolation of okadaic acid and dinophysistoxin-2.

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