Background and Purpose— Mechanical thrombectomy may involve multiple attempts to retrieve the occluding thrombus. This study examined the composition of thrombus fragments retrieved with each pass of a device during the thrombectomy procedure. Second, the per-pass composition was compared with procedural and clinical data including angiographic outcome and stroke etiology. Methods— Thrombi were retrieved from 60 patients with acute ischemic stroke, where thrombus fragments retrieved in each pass were segregated as individual samples and maintained throughout the histological analysis as independent samples. All samples were stained with hematoxylin and eosin and Martius Scarlet Blue. The relative composition of red blood cells, fibrin, and white blood cells in thrombus fragments from each pass was quantified. Results— Over the 60 cases, thrombus material was retrieved in 106 of 138 passes. The number of passes required to complete the cases ranged from 1 to 6 passes. The analysis of thrombus fragments retrieved in each pass provided a greater insight into the thrombectomy procedure progression than the overall thrombus composition; the red blood cell content of thrombus fragments retrieved in passes 1 and 2 was significantly higher than that retrieved in passes 3 to 6. The removal of thrombus material in a total of 1, 2, or 3 passes was associated with the highest percentage of final modified Thrombolysis in Cerebral Infarction score of 2c-3. There was no association between modified Thrombolysis in Cerebral Infarction score and per-pass thrombus composition. Conclusions— The differentiation achieved through the per-pass analysis of acute ischemic stroke thrombi provides a greater insight into the thrombectomy procedure progression than the combined per-case thrombus analysis. Insights gained may be a useful consideration in determining the treatment strategy as a case evolves and may be useful for the development of new devices to increase rates of 1-pass recanalization.

Seven different clot types were developed to replicate common AIS thrombi. These clot analogs may be beneficial for the preclinical evaluation of endovascular therapies, and may be applied to interventional technique training.

Amoebic gill disease (AGD) is a proliferative gill disease of marine cultured Atlantic salmon Salmo salar, with the free-living protozoan Neoparamoeba perurans being the primary aetiological agent. The increased incidence of AGD in recent years presents a significant challenge to the Atlantic salmon farming industry in Europe. In this study, a real-time TaqMan ® PCR assay was developed and validated to detect Neoparamoeba perurans on Atlantic salmon gills and further used to monitor disease progression on a marine Atlantic salmon farm in Ireland in conjunction with gross gill pathology and histopathology. The assay proved specific for N. perurans, with no cross-reactivity with the related species N. pemaquidensis, N. branchiphila or N. aestuarina, and was capable of detecting 2.68 copies of N. perurans DNA µl −1. Although the parasite was detected throughout the 18 mo period of this study, mortality peaks associated with clinical AGD were only recorded during the first 12 mo of the marine phase of the production cycle. The initial AGD outbreak resulted in peak mortality in Week 17, which was preceded by PCR detections from Week 13 onwards. Freshwater treatments were an effective method for controlling the disease, resulting in a reduction in the weekly mortality levels and also a reduction in the number of PCR-positive fish. In comparison to traditional diagnostic methods, our PCR assay proved to be highly sensitive and a valuable tool to monitor disease progression and, therefore, has the potential to provide information on the timing and effectiveness of treatments.

Amoebic gill disease (AGD) is one of the main diseases affecting Atlantic salmon (Salmo salar L.) mariculture. Hallmarks of AGD are hyperplasia of the lamellar epithelium and increased production of gill mucus. This study investigated the expression of genes involved in mucus secretion, cell cycle regulation, immunity and oxidative stress in gills using a targeted 21-gene PCR array. Gill samples were obtained from experimental and natural Neoparamoeba perurans infections, and sampling points included progressive infection stages and post-freshwater treatment. Up-regulation of genes related to mucin secretion and cell proliferation, and down-regulation of pro-inflammatory and pro-apoptotic genes were associated with AGD severity, while partial restoration of the gill homeostasis was detected post-treatment. Mucins and Th2 cytokines accoun ted for most of the variability observed between groups highlighting their key role in AGD. Two mucins (muc5, muc18) showed differential regulation upon disease. Substantial up-regulation of the secreted muc5 was detected in clinical AGD, and the membrane bound muc18 showed an opposite pattern. Th2 cytokines, il4/13a and il4/13b2, were significantly up-regulated from 2 days post-infection onwards, and changes were lesion-specific. Despite the differences between experimental and natural infections, both yielded comparable results that underline the importance of the studied genes in the respiratory organs of fish, and during AGD progression.

Gill diseases are a complex and multifactorial challenge for marine farmed Atlantic salmon. Co-infections with putative pathogens are common on farms; however, there is a lack of knowledge in relation to the potential effect co-infections may have on pathology. The objective of this study was to determine the prevalence and potential effects of Neoparamoeba perurans, Desmozoon lepeophtherii, Candidatus Branchiomonas cysticola, Tenacibaculum maritimum and salmon gill poxvirus (SGPV) during a longitudinal study on a marine Atlantic salmon farm. Real-time PCR was used to determine the presence and sequential infection patterns of these pathogens on gill samples collected from stocking until harvest. A number of multilevel models were used to determine the effect of these putative pathogens on gill health (measured as gill histopathology score), while adjusting for the effect of water temperature and time since the last freshwater treatment. Results indicate that between 12 and 16 weeks post-seawater transfer (wpst), colonization of the gills by all pathogens had commenced and by week 16 of marine production each of the pathogens had been detected. D. lepeophtherii and Candidatus B. cysticola were by far the most prevalent of the potential pathogens detected during this study. Detections of T. maritimum were found to be significantly correlated with temperature showing distinct seasonality. Salmon gill poxvirus was found to be highly sporadic and detected in the first sampling point, suggesting a carryover from the freshwater stage of production. Finally, the model results indicated no clear effect between any of the pathogens. Additionally, the models showed that the only variable which had a consistent effect on the histology score was N. perurans.