Clinical and health economic evaluation of a post-stroke arrhythmia monitoring service.

Atrial fibrillation (AF) is a major cause of recurrent stroke and transient ischaemic attack (TIA) in the UK. As many patients can have asymptomatic paroxysmal AF, prolonged arrhythmia monitoring is advised in selected patients following a stroke or TIA. This service evaluation assessed the clinical and potential health economic impact of prolonged arrhythmia monitoring post-stroke using R-TEST monitoring devices. This was a prospective, case-controlled, service evaluation in a single health board in the North of Scotland. Patients were included if they had a recent stroke or TIA, were in sinus rhythm, and did not have another indication for, or contraindication to, oral anticoagulation. A health economic model was developed to estimate the clinical and economic value delivered by the R-TEST monitoring. Approval to use anonymised patient data in this service evaluation was obtained. During the evaluation period, 100 consecutive patients were included. The average age was 70 ± 11 years, 46% were female. Stroke was the presenting complaint in 83% of patients with the other 17% having had a TIA. AF was detected in seven of 83 (8.4%) patients who had had a stroke and one of 17 (5.9%) patients with a TIA. Health economic modelling predicted that adoption of R-TEST monitoring has a high probability of demonstrating both clinical and economic benefits. In conclusion, developing a post-stroke arrhythmia monitoring service using R-TEST devices is feasible, effective at detecting AF, and represents a probable clinical and economic benefit.

Liquid chromatography with mass spectrometry--detection of lipophilic shellfish toxins.

A rapid multiple toxin method based on liquid chromatography with mass spectrometry (LC/MS) was developed for the detection of okadaic acid (OA), dinophysistoxin-1 (DTX-1), DTX-2, yessotoxin (YTX), homoYTX, 45-hydroxy-YTX, 45-hydroxyhomo-YTX, pectenotoxin-1 (PTX-1), PTX-2, azaspiracid-1 (AZA-1), AZA-2, and AZA-3. Toxins were extracted from shellfish using methanol-water (80%, v/v) and were analyzed using a C8 reversed-phase column with a 5 mM ammonium acetate-acetonitrile mobile phase under gradient conditions. The method was validated for the quantitative detection of OA, YTX, PTX-2, and AZA-1 in 4 species (mussels, Mytilus edulis; cockles, Cerastoderma edule; oysters, Crassostrea gigas; king scallop, Pecten maximus) of shellfish obtained from United Kingdom (UK) waters. Matrix interferences in the determination of the toxins in these species were investigated. The validated linear range of the method was 13-250 microg/kg for OA, PTX-2, and AZA-1 and 100-400 microg/kg for YTX. Recovery and precision ranged between 72-120 and 1-22%, respectively, over a fortification range of 40-160 microg/kg for OA, PTX-2, and AZA-1 and 100-400 microg/kg for YTX. The limit of detection, reproducibility, and repeatability of analysis showed acceptable performance characteristics. A further LC/MS method using an alkaline hydrolysis step was assessed for the detection of OA, DTX-1, and DTX-2 in their esterified forms. In combination with the LC/MS multiple toxin method, this allows detection of all toxin groups described in Commission Decision 2002/225/EC.

Assessment of MIST Alert, a commercial qualitative assay for detection of paralytic shellfish poisoning toxins in bivalve molluscs.

A recently developed commercial rapid test kit (MIST Alert) was assessed for determination of the presence of paralytic shellfish poisoning (PSP) toxins in shellfish. Several commercially important shellfish species obtained from the UK shellfish toxin monitoring program, containing a range of total PSP toxicities as determined by the mouse bioassay (MBA), were tested. The kit detected toxin in all samples containing the European Community tolerance level of 80 microg saxitoxin (STX) equivalents/100 g shellfish flesh as determined by the MBA. With one exception, the kit detected toxin in all samples that contained >40 microg STX equivalents/100 g according to the MBA. Among samples in which the MBA did not detect toxin, the kit disagreed in 25% of the tests, although further analysis by liquid chromatography (LC) and MBA of some samples confirmed the presence of toxins. These results suggest that MIST Alert may be suitable as an initial screen for PSP toxins as part of routine monitoring programs, thereby greatly reducing the number of MBAs. Trials were also performed by nonscientific personnel to evaluate the ease of use and interpretation of results obtained by MIST Alert. The results indicated that the kits could be readily used and accurately interpreted by individuals with no technical or scientific background.

Oceanicaulis alexandrii gen. nov., sp. nov., a novel stalked bacterium isolated from a culture of the dinoflagellate Alexandrium tamarense (Lebour) Balech.

Five bacterial strains were isolated from a non-toxigenic strain of the marine dinoflagellate Alexandrium tamarense (Lebour) Balech CCMP 116 (NEPCC C116), during a survey of the diversity of bacteria associated with paralytic shellfish toxin-producing cultures of Alexandrium spp. (Dinophyta). All strains were strictly aerobic, Gram-negative, straight or curved rods. Cells were dimorphic, with stalks (or prosthecae) and non-motile or non-stalked and motile, by means of a single polar flagellum. The bacteria grew best at salt concentrations ranging from 2 to 10 % and growth occurred at 10 degrees C, but not at 50 degrees C. The G+C content of the chromosomal DNA of the strains was determined to be 61-62 mol%. Major cellular fatty acids of the bacteria presented a unique profile. 16S rRNA gene sequence analysis showed the five strains to be related to genera of budding bacteria of marine origin in the 'Alphaproteobacteria', namely, Hirschia, Maricaulis and Hyphomonas, although they exhibited substantial differences in morphology, substrate utilization and fatty acid profile to members of these genera. The five strains are proposed to comprise a new species of a new genus, Oceanicaulis alexandrii gen. nov., sp. nov., the type strain of which is C116-18(T) (=DSM 11625(T)=NCIMB 13905(T)).