Characterisation of Crandell-Rees Feline Kidney (CRFK) cells as mesenchymal in phenotype

The Crandell-Rees Feline Kidney Cell (CRFK) is an immortalised cell line derived from the feline kidney that is utilised for the growth of certain vaccinal viruses. Confusion exists as to whether CRFK are epithelial or mesenchymal in phenotype. The aim of this study was to characterise CRFK cells via immunofluorescence, enzyme cytochemistry, western blotting, RT-qPCR for S100A4 and comparison to primary feline proximal tubular epithelial cells (FPTEC) and feline cortical fibroblasts (FCF). CRFK cells were of fusiform morphology and appeared similar to FCF. CRFK expressed the mesenchymal intermediate filament (IF) protein vimentin together with two cell adhesion molecules associated with feline fibroblasts (CD29 and CD44), and lacked expression of the epithelial IF cytokeratin, myogenic IF desmin and endothelial marker von Willebrand factor (vWF). In addition, CRFK did not demonstrate brush border enzyme activity typical of FPTEC. S100A4 gene expression, implicated in both neoplastic transformation and epithelial to mesenchymal transition, was highly upregulated in CRFK in comparison to the primary feline renal cells. CRFK appear phenotypically similar to fibroblasts, rather than tubular epithelial cells, and may have undergone neoplastic transformation or epithelial-to-mesenchymal transition after extensive passaging. This finding may have potential implications for future research utilising this cell line

Mechanical characterization of thrombi retrieved with endovascular thrombectomy in patients with acute ischemic stroke

Background and Purpose: Mechanical properties of thromboemboli play an important role in the efficacy of endovascular thrombectomy (EVT) for acute ischemic stroke. However, very limited data on mechanical properties of human stroke thrombi are available. We aimed to mechanically characterize thrombi retrieved with EVT, and to assess the relationship between thrombus composition and thrombus stiffness. Methods: Forty-one thrombi from 19 patients with acute stroke who underwent EVT between July and October 2019 were mechanically analyzed, directly after EVT. We performed unconfined compression experiments and determined tangent modulus at 75% strain (E-t75) as a measure for thrombus stiffness. Thrombi were histologically analyzed for fibrin/platelets, erythrocytes, leukocytes, and platelets, and we assessed the relationship between histological components and E-t75 with univariable and multivariable linear mixed regression. Results: Median E-t75 was 560 (interquartile range, 393-1161) kPa. In the multivariable analysis, fibrin/platelets were associated with increased E-t75 (a beta, 9 [95% CI, 5 to 13]) kPa, erythrocytes were associated with decreased E-t75% (a beta, -9 [95% CI, -5 to -13]) kPa. We found no association between leukocytes and E-t75. High platelet values were strongly associated with increased E-t75 (a beta, 56 [95% CI, 38-73]). Conclusions: Fibrin/platelet content of thrombi retrieved with EVT for acute ischemic stroke is strongly associated with increased thrombus stiffness. For thrombi with high platelet values, there was a very strong relationship with thrombus stiffness. Our data provide a basis for future research on the development of next-generation EVT devices tailored to thrombus composition.Neuro Imaging Researc

High-Resolution Imaging of Interaction Between Thrombus and Stent-Retriever in Patients With Acute Ischemic Stroke

Paroxysmal Cerebral Disorder

Neoatherosclerosis development following bioresorbable vascular scaffold implantation in diabetic and non-diabetic swine

Background: DM remains a risk factor for poor outcome after stent-implantation, but little is known if and how DM affects the vascular response to BVS. Aim: The aim of our study was to examine coronary responses to bioresorbable vascular scaffolds (BVS) in swine with and without diabetes mellitus fed a ‘fast-food’ diet (FF-DM and FF-NDM, respectively) by sequential optical coherence tomography (OCT)-imaging and histology. Methods: Fifteen male swine were evaluated. Eight received streptozotocin-injection to induce DM. After 9 months (M), 32 single BVS were implanted in epicardial arteries with a stent to artery (S/A)-ratio of 1.1:1 under quantitative coronary angiography (QCA) and OCT guidance. Lumen, scaffold, neointimal coverage and composition were assessed by QCA, OCT and near-infrared spectroscopy (NIRS) pre- and/or post-procedure, at 3M and 6M. Additionally, polarization-sensitive (PS)-OCT was performed in 7 swine at 6M. After sacrifice at 3M and 6M, histology and polymer degradation analysis were performed. Results: Late lumen loss was high (~60%) within the first 3M after BVS-implantation (P0.20). Neointimal coverage was highly heterogeneous in all swine (DM vs. NDM P>0.05), with focal lipid accumulation, irregular collagen distribution and neointimal calcification. Likewise, polymer mass loss was low (~2% at 3M, ~5% at 6M;P>0.20) and not associated with DM or inflammation. Conclusion: Scaffold coverage showed signs of neo-atherosclerosis in all FF-DM and FF-NDM swine, scaffold polymer was preserved and the vascular response to BVS was not influenced by diabetes

Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies

Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease. Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ∼10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results. Methods: The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings. Results: Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text. Conclusions: This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data

The influence of channel deepening on estuarine turbidity levels and dynamics, as exemplified by the Ems estuary

Active deepening of tidal channels usually results in the alteration of the vertical and the horizontal tide. This may lead to concurrent significant increases in mean suspended matter concentrations (SPM) in coastal plain estuaries, the turbidity maximum (ETM) included. This is exemplified by an extensive analysis of the Ems estuary, a prototypical heavily stressed estuary in the Dutch-German border area. Measurements show that the SPM concentrations in the lower reaches of the estuary have increased an average of 2- to 3-fold between 1954 and 2005, with a 10-fold increase observed in the upper estuary (tidal river). Longitudinal profiles of surface SPM demonstrate that the ETM has moved upstream by up to 25 km and has broadened into a zone 30 km in length which extends into the freshwater tidal river. On an annual scale, variations in freshwater discharge significantly influence the formation and breakdown of the ETM: during low river discharge the ETM approaches equilibrium over 2e3 months, whilst elevated river discharges relocate the ETM downstream over several weeks. An exploratory, semi-analytical model is calibrated to simulate the equilibrium SPM distribution in the upper estuary during five time periods from 1965 to 2005, using archival bathymetric and tidal data. Results suggest that the deepening of tidal channels and a reduction in hydraulic drag have most likely resulted in a landward shift of the SPM trapping location. The measured increase in SPM concentrations and the development of fluid mud around the 1990s likely contributed to reduced mixing and bottom drag, creating a feedback loop that further altered tidal and SPM dynamics. It is argued that the removal of some non-erodible (consolidated) layers in the lower reaches of the estuary has created new internal sediment sources that may be responsible for feeding the observed high SPM concentrations, rather than increased sediment input from the boundaries. All findings are based on and supported by measured short-term seasonal fluctuations, as well as long-term developments of yearly averaged concentrations in the longitudinal SPM distribution

Energieumsatz und Muskelstruktur bei Langzeitbelastung : eine Fallstudie

BACKGROUND AND STUDY AIMS: Hemospray (Cook Medical Inc., Winston-Salem, North Carolina, USA) is a novel, hemostatic, powder spray that has been developed for gastrointestinal use. The powder is thought to achieve hemostasis by concentrating clotting factors and forming a mechanical plug on the injured blood vessel. However, no detailed studies on the hemostatic mode of action have been performed. The aim of this study was to examine the effects of Hemospray on coagulation and clot formation both in vitro and in vivo. MATERIALS AND METHODS: Recalcification time, thromboelastometry using EXTEM and INTEM assays, and plasma coagulation tests (activated partial thromboplastin time and prothrombin time) were carried out on blood samples mixed with Hemospray, and compared with talcum powder (negative control) and kaolin (positive control) at 1 mg/mL and 10 mg/mL. Scanning electron microscopy (SEM) and light microscopy were performed on in vitro thrombi and on gastric thrombi from an animal model of gastrointestinal hemorrhage treated with Hemospray. RESULTS: The median recalcification time of whole blood was 187.5 seconds. The addition of 1 mg/mL and 10 mg/mL Hemospray significantly shortened this time (median 60 and 45 seconds, respectively; P < 0.05). The median clotting time of whole blood, measured using the INTEM assay, was 160 seconds (interquartile range [IQR] 159 - 176.5) and this was also significantly reduced by the addition of Hemospray (91 seconds [IQR 84 - 102]; P = 0.005). The plasma prothrombin time of 11.6 seconds was significantly reduced by Hemospray (9.5 seconds; P = 0.011). SEM of in vivo clots demonstrated that Hemospray rapidly interacted with whole blood, forming one confluent mass over the bleeding site. In sufficient amounts, Hemospray was able to deform and pack erythrocytes. CONCLUSIONS: Hemospray covered the bleeding site and enhanced clot formation in vivo, and shortened coagulation time in vitro. Elaboration of these unique properties in clinical practice will help to optimize future endoscopic hemostasis with Hemospray