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Aim: (i) To quantify biofilm removal from a simulated isthmus and a lateral canal in an artificial root canal system during syringe irrigation with NaOCl at different concentrations and delivered at various flow rates (ii) to examine whether biofilm removal is further improved by a final high‐flow‐rate rinse with an inert irrigant following irrigation with NaOCl. (iii) to simulate the irrigant flow in these areas using a computer model (iv) to examine whether the irrigant velocity calculated by the computer model is correlated to biofilm removal. Methodology: Ninety‐six artificial root canals with either a simulated isthmus or lateral canal were used. A dual‐species in vitro biofilm was formed in these areas using a Constant Depth Film Fermenter. NaOCl at various concentrations (2, 5 and 10%) or adhesion buffer (control) was delivered for 30 s by a syringe and an open‐ended needle at 0.033, 0.083, or 0.166 mL s−1 or passively deposited in the main root canal (phase 1). All specimens were subsequently rinsed for 30 s with adhesion buffer at 0.166 mL s−1 (phase 2). The biofilm was scanned by Optical Coherence Tomography to determine the percentage of the remaining biofilm. Results were analysed by two 3‐way mixed‐design ANOVAs (α = 0.05). A Computational Fluid Dynamics model was used to simulate the irrigant flow inside the artificial root canal system. Results: The flow rate during phase 1 and additional irrigation during phase 2 had a significant effect on the percentage of the remaining biofilm in the isthmus (P = 0.004 and P < 0.001). Additional irrigation during phase 2 also affected the remaining biofilm in the lateral canal significantly (P ≤ 0.007) but only when preceded by irrigation at medium or high flow rate during phase 1. The effect of NaOCl concentration was not significant (P > 0.05). Irrigant velocity in the isthmus and lateral canal increased with increasing flow rate and it was substantially correlated to biofilm removal from those areas. Conclusions: The irrigant flow rate affected biofilm removal in vitro more than NaOCl concentration. Irrigant velocity predicted by the computer model corresponded with the pattern of biofilm removal from the simulated isthmus and lateral canal. [ABSTRACT FROM AUTHOR]

Abstract: Aim: To investigate the effects of ultrasonic activation file type, lateral canal location and irrigant on the removal of a biofilm‐mimicking hydrogel from a fabricated lateral canal. Additionally, the amount of cavitation and streaming was quantified for these parameters. Methodology: An intracanal sonochemical dosimetry method was used to quantify the cavitation generated by an IrriSafe 25 mm length, size 25 file inside a root canal model filled with filtered degassed/saturated water or three different concentrations of NaOCl. Removal of a hydrogel, demonstrated previously to be an appropriate biofilm mimic, was recorded to measure the lateral canal cleaning rate from two different instruments (IrriSafe 25 mm length, size 25 and K 21 mm length, size 15) activated with a P5 Suprasson (Satelec) at power P8.5 in degassed/saturated water or NaOCl. Removal rates were compared for significant differences using nonparametric Kruskal–Wallis and/or Mann–Whitney U‐tests. Streaming was measured using high‐speed particle imaging velocimetry at 250 kfps, analysing both the oscillatory and steady flow inside the lateral canals. Results: There was no significant difference in amount of cavitation between tap water and oversaturated water (P = 0.538), although more cavitation was observed than in degassed water. The highest cavitation signal was generated with NaOCl solutions (1.0%, 4.5%, 9.0%) (P < 0.007) and increased with concentration (P < 0.014). The IrriSafe file outperformed significantly the K‐file in removing hydrogel (P < 0.05). Up to 64% of the total hydrogel volume was removed after 20 s. The IrriSafe file typically outperformed the K‐file in generating streaming. The oscillatory velocities were higher inside the lateral canal 3 mm compared to 6 mm from WL and were higher for NaOCl than for saturated water, which in turn was higher than for degassed water. Conclusions: Measurements of cavitation and acoustic streaming have provided insight into their contribution to cleaning. Significant differences in cleaning, cavitation and streaming were found depending on the file type and size, lateral canal location and irrigant used. In general, the IrriSafe file outperformed the K‐file, and NaOCl performed better than the other irrigants tested. The cavitation and streaming measurements revealed that both contributed to hydrogel removal and both play a significant role in root canal cleaning. [ABSTRACT FROM AUTHOR]

Diffusion tensor imaging (DTI) is a popular method to assess differences in fiber organization in diseased and healthy muscle tissue. Previous work has shown that muscle DTI measurements depend on signal-to-noise ratio (SNR), %fat, and tissue T2. The goal of this study was to evaluate the potential biasing effects of these factors on skeletal muscle DTI data in patients with Duchenne Muscular Dystrophy (DMD). MR images were obtained of the right lower leg of 21 DMD patients and 12 healthy controls on a Philips 3T system. DTI measurements were combined with quantitative in-vivo measures of mean water T2, %fat and SNR to evaluate their effect on DTI parameter estimation. All outcome measures were determined within ROIs drawn for six lower leg muscles. Between group analysis, using all ROIs, revealed a significantly elevated FA in the GCL, SOL and PER muscles ( p<0.05) and an increased mean diffusivity ( p<0.05) and λ3 ( p<0.05) in the TA muscle of DMD patients. In-vivo evaluation of the individual confounders showed behaviour in line with predictions from previous simulation work. To account for these confounders, subsequent analysis used only ROIs with SNR greater than 20. With this criterion we found significantly greater MD in the TA muscle of DMD patient ( p<0.009) and λ3 in the TA and GCL muscles ( p<0.001) of DMD patients, but no differences in FA. As both increased %fat and lower SNR are expected to reduce the apparent MD and λ3, these between-group differences are likely due to pathophysiology. However, the increased FA, observed when using all ROIs, likely reflects the effect of low SNR and %fat on the DTI parameter estimation. These findings suggest that measuring mean water T2, %fat and SNR is essential to ascribe changes in DTI measures to intrinsic diffusion changes or to confounding influences. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT The use of stem cells for the repair of damaged cardiac tissue after a myocardial infarction holds great promise. However, a common finding in experimental studies is the low number of cells delivered at the area at risk. To improve the delivery, we are currently investigating a novel delivery platform in which stem cells are conjugated with targeted microbubbles, creating echogenic complexes dubbed StemBells. These StemBells vibrate in response to incoming ultrasound waves making them susceptible to acoustic radiation force. The acoustic force can then be employed to propel circulating StemBells from the centerline of the vessel to the wall, facilitating localized stem cell delivery. In this study, we investigate the feasibility of manipulating StemBells acoustically in vivo after injection using a chicken embryo model. Bare stem cells or unsaturated stem cells (<5 bubbles/cell) do not respond to ultrasound application (1 MHz, peak negative acoustical pressure P_ = 200 kPa, 10% duty cycle). However, stem cells which are fully saturated with targeted microbubbles (>30 bubbles/cell) can be propelled toward and arrested at the vessel wall. The mean translational velocities measured are 61 and 177 μm/s for P- = 200 and 450 kPa, respectively. This technique therefore offers potential for enhanced and well-controlled stem cell delivery for improved cardiac repair after a myocardial infarction. Biotechnol. Bioeng. 2015;112: 220-227. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Aim To introduce and characterize a reproducible hydrogel as a suitable biofilm mimic in endodontic research. To monitor and visualize the removal of hydrogel from a simulated lateral canal and isthmus for the following: I) Ultrasonic-Activated Irrigation (UAI) with water, ii) UAI with NaOCl and iii) NaOCl without UAI. Methodology A rheometer was used to characterize the viscoelastic properties and cohesive strength of the hydrogel for suitability as a biofilm mimic. The removal rate of the hydrogel from a simulated lateral canal or isthmus was measured by high-speed imaging operating at frame rates from 50 to 30 000 fps. Results The hydrogel demonstrated viscoelastic behaviour with mechanical properties comparable to real biofilms. UAI enhanced the cleaning effect of NaOCl in isthmi (P < 0.001) and both NaOCl and water in lateral canals (P < 0.001). A greater depth of cleaning was achieved from an isthmus (P = 0.009) than from a lateral canal with UAI and also at a faster rate for the first 20 s. NaOCl without UAI resulted in a greater depth of hydrogel removal from a lateral canal than an isthmus (P < 0.001). The effect of UAI was reduced when stable bubbles were formed and trapped in the lateral canal. Different removal characteristics were observed in the isthmus and the lateral canal, with initial highly unstable behaviour followed by slower viscous removal inside the isthmus. Conclusions The biofilm-mimicking hydrogel is reproducible, homogenous and can be easily applied and modified. Visualization of its removal from lateral canal anatomy provides insights into the cleaning mechanisms of UAI for a biofilm-like material. Initial results showed that UAI improves hydrogel removal from the accessory canal anatomy, but the creation of stable bubbles on the hydrogel-liquid interface may reduce the cleaning rate. [ABSTRACT FROM AUTHOR]

Aim (i) To evaluate the effect of needle type and insertion depth, root canal size and irrigant flow rate on the entrapment of air bubbles in the apical part of a root canal (apical vapor lock) during syringe irrigation using experiments and a Computational Fluid Dynamics ( CFD) model, (ii) to investigate whether the irrigant contact angle affects bubble entrapment, (iii) to examine if an established vapor lock can be removed by syringe irrigation. Methodology Bubble entrapment during irrigation of straight artificial root canals of size 35 or 50 was evaluated by real-time visualizations. The irrigant was delivered by a closed-ended or an open-ended needle positioned at 1 or 3 mm short of working length (WL) and at a flow rate of 0.033-0.260 mL s−1. Results were analysed by nonparametric tests at 0.05 significance. Selected cases were also simulated by a two-phase CFD model. Results A vapor lock was observed in 48% of the cases investigated experimentally. Increasing the apical size, using an open-ended needle, positioning the needle closer to WL and delivering the irrigant at higher flow rate resulted in significantly smaller vapor lock. An increased contact angle resulted in the entrapment of a larger bubble when a low flow rate was used. Both brief insertion of the needle to WL whilst irrigating at a flow rate of 0.083 mL s−1 and delivering the irrigant at 0.260 mL s−1 without changing the needle position were capable of removing an established vapor lock. Conclusions Apical vapor lock may occur under certain conditions, but appears to be easily prevented or removed by syringe irrigation. [ABSTRACT FROM AUTHOR]

Aim To evaluate the effect of multiple refreshment/activation cycles and temperature on the reaction rate of sodium hypochlorite (NaOCl) with bovine dentine during ultrasonic activated irrigation (UAI) under laboratory conditions. Methodology The root canal walls of 24 standardized root canals in bovine incisors were exposed to a standardized volume of NaOCl at different temperatures (24 °C and 38 °C) and exposure times (20, 60 and 180 s). The irrigant was refreshed and ultrasonically activated four times for 20 s followed by a 40 s rest interval, with no refreshment and no activation as the controls. The reaction rate was determined by measuring the amount of active chlorine in the NaOCl solution before and after being exposed to dentine during the specific experimental conditions. Calorimetry was used to measure the electrical-to-sonochemical conversion efficiency during ultrasonic activation. Results Refreshment, activation and exposure time all increased the reaction rate of NaOCl ( P < 0.05). During activation, the temperature of the irrigant increased up to 10 °C. Such temperature rise was insufficient to enhance the reaction rate of NaOCl ( P > 0.125). Conclusions The reaction rate of NaOCl with dentine is enhanced by refreshment, ultrasonic activation and exposure time. Temperature rise of irrigant during ultrasonic activation was not sufficient to alter the reaction rate. [ABSTRACT FROM AUTHOR]

Aim (i) To quantify in a simulated root canal model the file-to-wall contact during ultrasonic activation of an irrigant and to evaluate the effect of root canal size, file insertion depth, ultrasonic power, root canal level and previous training, (ii) To investigate the effect of file-to-wall contact on file oscillation. Methodology File-to-wall contact was measured during ultrasonic activation of the irrigant performed by 15 trained and 15 untrained participants in two metal root canal models. Results were analyzed by two 5-way mixed-design anovas. The level of significance was set at P < 0.05. Additionally, high-speed visualizations, laser-vibrometer measurements and numerical simulations of the file oscillation were conducted. Results File-to-wall contact occurred in all cases during 20% of the activation time. Contact time was significantly shorter at high power ( P < 0.001), when the file was positioned away from working length ( P < 0.001), in the larger root canal ( P < 0.001) and from coronal towards apical third of the root canal ( P < 0.002), in most of the cases studied. Previous training did not show a consistent significant effect. File oscillation was affected by contact during 94% of the activation time. During wall contact, the file bounced back and forth against the wall at audible frequencies (ca. 5 kHz), but still performed the original 30 kHz oscillations. Travelling waves were identified on the file. The file oscillation was not dampened completely due to the contact and hydrodynamic cavitation was detected. Conclusion Considerable file-to-wall contact occur-red during irrigant activation. Therefore, the term ' Passive Ultrasonic Irrigation' should be amended to ' Ultrasonically Activated Irrigation'. [ABSTRACT FROM AUTHOR]

Spatio-temporal magnetic field changes in the brain caused by breathing or body movements can lead to image artifacts. This is especially a problem in T2*-weighted sequences. With the acquisition of an extra echo (navigator), it is possible to measure the magnetic field change induced frequency offset for a given slice during image acquisition. However, substantial local variation across a slice can occur. This work describes an extension of the conventional navigator technique that improves the estimation of the magnetic field distribution in the brain during strong field fluctuations. This is done using the combination of signals from multiple coil elements, the coil sensitivity profiles, and frequency encoding: termed sensitivity-encoded navigator echoes. In vivo validation was performed in subjects who performed normal breathing, nose touching, and deep breathing during scanning. The sensitivity-encoded navigator technique leads to an error reduction in estimating the field distribution in the brain of 73% ± 16% compared with 56% ± 14% for conventional estimation. Image quality can be improved via incorporating this navigator information appropriately into the image reconstruction. When the sensitivity-encoded navigator technique was applied to a T2*-weighted sequence at 7 T, a ghosting reduction of 47% ± 13% was measured during nose touching experiments compared with no correction. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Boutsioukis C, Gogos C, Verhaagen B, Versluis M, Kastrinakis E, van der Sluis LWM. The effect of apical preparation size on irrigant flow in root canals evaluated using an unsteady Computational Fluid Dynamics model. International Endodontic Journal, 43, 874–881, 2010. Aim To evaluate the effect of apical preparation size on irrigant flow inside a root canal during final irrigation with a syringe and two different needles types, using a Computational Fluid Dynamics (CFD) model. Methodology A validated CFD model was used to simulate the irrigant flow from either a side-vented or a flat 30G needle positioned inside root canals having sizes of 25, 35, 45 and 55, all with a .06 taper, at 3 mm short of working length (WL). Velocity, pressure and shear stress in the root canal were evaluated. Results Different preparation sizes resulted in minor differences in the flow pattern in the apical root canal. Major differences were observed between the two needle types. The side-vented needle could not achieve irrigant replacement to the WL even in a size 55, .06 taper root canal. Significant irrigant replacement was evident almost to the WL in size 35, 45 and 55, .06 taper root canals with the flat needle. The maximum shear stress decreased as the preparation size increased. The flat needle developed higher mean pressure at the apical foramen. Both needles led to a similar gradual decrease in apical pressure as the preparation size increased. Conclusions Apical preparation size affected irrigant replacement, the shear stress on the canal wall and the pressure at the apical foramen. Root canal enlargement to sizes larger than 25 appeared to improve the performance of syringe irrigation. Adequate space between the needle and the canal wall should be ensured to allow for an effective reverse flow of the irrigant towards the canal orifice. [ABSTRACT FROM AUTHOR]

Boutsioukis C, Gogos C, Verhaagen B, Versluis M, Kastrinakis E, van der Sluis LWM. The effect of root canal taper on the irrigant flow: evaluation using an unsteady Computational Fluid Dynamics model. International Endodontic Journal, 43, 909–916, 2010. Aim To evaluate the effect of root canal taper on irrigant flow inside a prepared root canal during final irrigation with a syringe and two types of needles, using a Computational Fluid Dynamics (CFD) model. Methodology A validated CFD model was used to simulate irrigant flow from either a side-vented or a flat 30G needle positioned inside size 30, .02 taper, 30, .04, 30, .06, ProTaper F3 or size 60, .02 taper root canals, at 3 mm short of working length (WL). Velocity, pressure and shear stress in the root canal were evaluated. Results The side-vented needle could not achieve irrigant replacement to the WL in any of the cases. Significant irrigant replacement was evident further than 2 mm apically to the tip of the flat needle in the size 30, .06 taper, F3 and size 60, .02 taper canal. A wider distribution of wall shear stress was noted as the canal taper increased but the maximum shear stress decreased. The flat needle led to higher mean pressure at the apical foramen. Both needles showed a similar gradual decrease in apical pressure as the taper increased, but the least pressure was calculated in the size 60, .02 taper canal. Conclusions An increase in root canal taper improved irrigant replacement and wall shear stress whilst reducing the risk for irrigant extrusion. Irrigant flow in a minimally tapered root canal with a large apical preparation size also improved irrigant replacement and wall shear stress and reduced the risk for irrigant extrusion, compared to the tapered root canals with a smaller apical preparation size. [ABSTRACT FROM AUTHOR]

Boutsioukis C, Verhaagen B, Versluis M, Kastrinakis E, van der Sluis LWM. Irrigant flow in the root canal: experimental validation of an unsteady Computational Fluid Dynamics model using high-speed imaging. International Endodontic Journal 43, 393–403, 2010. Aim To compare the results of a Computational Fluid Dynamics (CFD) simulation of the irrigant flow within a prepared root canal, during final irrigation with a syringe and a needle, with experimental high-speed visualizations and theoretical calculations of an identical geometry and to evaluate the effect of off-centre positioning of the needle inside the root canal. Methodology A CFD model was created to simulate irrigant flow from a side-vented needle inside a prepared root canal. Calculations were carried out for four different positions of the needle inside a prepared root canal. An identical root canal model was made from poly-dimethyl-siloxane (PDMS). High-speed imaging of the flow seeded with particles and Particle Image Velocimetry (PIV) were combined to obtain the velocity field inside the root canal experimentally. Computational, theoretical and experimental results were compared to assess the validity of the computational model. Results Comparison between CFD computations and experiments revealed good agreement in the velocity magnitude and vortex location and size. Small lateral displacements of the needle inside the canal had a limited effect on the flow field. Conclusions High-speed imaging experiments together with PIV of the flow inside a simulated root canal showed a good agreement with the CFD model, even though the flow was unsteady. Therefore, the CFD model is able to predict reliably the flow in similar domains. [ABSTRACT FROM AUTHOR]

Aim To test ex vivo the efficiency of laser-activated irrigation in removing dentine debris from the apical part of the root canal and to visualize in vitro the fluid dynamics during the activation of the irrigant by laser, using high-speed imaging at a relevant timescale. Methodology Root canals with a standardized groove in one canal wall filled with dentine debris were irrigated with syringe irrigation, ultrasonically or laser-activated irrigation (LAI) using 2% sodium hypochlorite as irrigant. The quantity of dentine debris after irrigation was determined. Visualization of the fluid dynamics during activation was achieved using a high-speed camera and a glass model. Results Laser-activated irrigation was significantly more effective in removing dentine debris from the apical part of the root canal than passive ultrasonic irrigation or hand irrigation when the irrigant was activated for 20 s. Conclusions The in vitro recordings suggest that streaming, caused by the collapse of the laser-induced bubble, is the main cleaning mechanism of LAI. [ABSTRACT FROM AUTHOR]

Background: Adenosine is a signalling nucleoside that has been proposed to contribute to the pathogenesis of asthma. Adenosine is produced in inflammatory environments and acts via adenosine receptors (A1R, A2AR, A2BR, and A3R) expressed by a wide variety of cells, resulting in pro- and anti-inflammatory effects. Objective: To compare AR expression in asthma patients and healthy subjects, and to assess the effect of allergen challenge on AR expression of inflammatory cells and on cytokines in peripheral blood and sputum in asthma. Methods: Asthma patients underwent an allergen challenge, and blood and induced sputum samples were taken before and 24 h after allergen challenge to study inflammatory cells numbers, AR expression and cytokine production. Blood and sputum were investigated at one time point in healthy subjects. AR expression was measured by flow cytometry (blood) or on cytospins using immunocytochemistry (sputum). Cytokines (luminex, ELISA) and adenosine (HPLC) were measured in sputum supernatant. Results: The percentage of A2BR expressing neutrophils in sputum was lower in asthma patients than in healthy subjects ( P = 0.016). Allergen challenge decreased A1R and A2AR expression on neutrophils and A1R expression on T cells in peripheral blood (all P < 0.05). Allergen challenge increased IL-8 levels and eosinophil numbers ( P < 0.05), whereas it decreased thymic stromal lymphopoietin levels and the percentage of A1R expressing macrophages in induced sputum ( P < 0.05). Conclusions: Allergen challenge has a down-regulatory effect on AR expression in asthma, suggesting a contribution of adenosine-related effector mechanisms in the pathophysiology. [ABSTRACT FROM AUTHOR]

Ultrasonic irrigation of the root canal can be performed with or without simultaneous ultrasonic instrumentation. When canal shaping is not undertaken the term passive ultrasonic irrigation (PUI) can be used to describe the technique. In this paper the relevant literature on PUI is reviewed from a MEDLINE database search. Passive ultrasonic irrigation can be performed with a small file or smooth wire (size 10–20) oscillating freely in the root canal to induce powerful acoustic microstreaming. PUI can be an important supplement for cleaning the root canal system and, compared with traditional syringe irrigation, it removes more organic tissue, planktonic bacteria and dentine debris from the root canal. PUI is more efficient in cleaning canals than ultrasonic irrigation with simultaneous ultrasonic instrumentation. PUI can be effective in curved canals and a smooth wire can be as effective as a cutting K-file. The taper and the diameter of the root canal were found to be important parameters in determining the efficacies of dentine debris removal. Irrigation with sodium hypochlorite is more effective than with water and ultrasonic irrigation is more effective than sonic irrigation in the removal of dentine debris from the root canal. The role of cavitation during PUI remains inconclusive. No detailed information is available on the influence of the irrigation time, the volume of the irrigant, the penetration depth of the instrument and the shape and material properties of the instrument. The influence of irrigation frequency and intensity on the streaming pattern as well as the complicated interaction of acoustic streaming with the adherent biofilm needs to be clarified to reveal the underlying physical mechanisms of PUI. [ABSTRACT FROM AUTHOR]

Purpose Uveal melanoma (UM) is an intraocular neoplasm with an annual incidence of 7 per million. UM originates from melanocytes just like cutaneous melanoma (CM) and similar to CM, the MAPK pathway is involved in the development of UM. However, not all UM seem to depend on the activation of this pathway. Loss of ERK signalling may be correlated with progression as the ERK negative cells are derived from UM metastasis. Here, tumours apparently use different mechanisms to proliferate and survive. In this study, we aimed to determine the pathway that is up‐regulated in UM metastases and to inhibit its function with targeted kinase inhibitors. Methods We used pathway profiling to identify the pathways that are important in metastases. Furthermore, the c‐Met inhibitor (Crizotinib) was used to inhibit the c‐Met receptor and to identify downstream targets. Colony formation assays and 3D sphere assays were used to characterize UM cells in a three dimensional environment. Results Reduced c‐Met activation rather than reduced expression was induced with Crizotinib treatment. Subsequently, c‐Met inhibition was correlated with reduced colony formation. c‐Met positive UM cells captured in 3D spheres revealed a reduced capacity to migrate upon Crizotinib treatment compared to cells that lack activated c‐Met. Conclusion c‐Met activation was observed in metastasizing UM where it serves as biomarker for Crizotinib treatment. Efficacy of treatment was shown by inhibition of growth and migration. Combined our data reveals c‐Met signalling in progression of UM and support the use of Crizotinib for UM metastasis. [ABSTRACT FROM AUTHOR]

Purpose Uveal melanoma (UM) leads to metastasis in up to 50% of the patients. Patients at risk are readily identified using an array of prognostic markers but an effective treatment is lacking. We recently identified Src as an important tyrosine kinase that conveys MAPK activation in UM. GNAQ/GNA11 mutations are the common denominators of oncogene signalling in UM and Src is a likely downstream kinase. We describe the preclinical analysis of Dasatinib, a known inhibitor or Src kinase, in UM. Methods Eight tumours were removed, cultured and exposed to Dasatinib treatment. proliferation and MAPK signalling were evaluated. Additionally, 36 UM samples were analyzed for Src/ERK signalling, GNAQ/GNA11 mutation status, chromosome 3 and known histological prognostic parameters. Results Growth arrest was observed in 5 of 8 UM cultures and molecular analysis indicated that Dasatinib inhibited MAPK via Src. Treatment efficacy associated with MAPK and Src kinase activity as UM cells with the highest Src activity and MAPK activation displayed the strongest growth inhibition. Furthermore, treatment responses tended to be better in UM cultures with monosomy 3. In the cohort of primary UM, Src expression was highly correlated with MAPK activation and monosomy 3. Conclusion We identified the Src family kinase inhibitor, Dasatinib, as a treatment option for UM. Dasatinib inhibits UM proliferation and may also inhibit UM progression as an association between Src and monosomy 3 was revealed. Consequently, monosomy 3 analysis in tumour tissue may suffice both the prognosis and choice of treatment. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the role of 3 Tesla MRI in the diagnosis, measurement and treatment planning of choroidal and iridociliary melanoma and comparison of results with Ultrasound and histology to measure the accuracy of MRI. Methods : Prospective analyses of consecutive 12 patients, four with iridociliary and eight having choroidal melanocytic tumors. All these patients had ultrasound (10MHz) or UBM (50MHz), 3 Tesla MRI and underwent primary enucleation. The enucleated eyes were examined for gross measurements and histopathology was done. Results Iris/iridociliary melanocytic tumors showed that MRI was positive in two cases and comparable to UBM. In one case tumor was identifiable only on saggital sections while in one case of Leiomyoma MRI gave much details and enhancement patterns. For posterior tumors MRI was positive in all the eight cases and results were comparable to ultrasound and macroscopic pathology in six cases. Conclusion 3 Tesla MRI showed comparable results to UBM /USG and macroscopic pathology in 80% of patients. MRI should be performed if clinical and USG are in doubt to get additional information for diagnosis of other melanocytic tumors. An important finding was that for iris‐iridociliary melanomas MRI saggital images should be used for interpretation. [ABSTRACT FROM AUTHOR]

Purpose Uveal melanoma with a bad prognosis contain high numbers of infiltrating macrophages, especially of the M2 phenotype, and different subsets of lymphocytes. The aim of this study is to determine the presence of inflammatory cells in uveal melanoma‐containing eyes enucleated after different types of irradiation, i.e. ruthenium‐106 brachytherapy, sandwich therapy, or proton beam irradiation. Methods We analyzed 46 eyes enucleated due to tumor recurrence, non‐responsiveness, or complications after irradiation. Immunofluorescence staining was performed to determine the presence of CD68+ and CD68+CD163+macrophages, CD3+, CD8+ and Foxp3+ regulatory T lymphocytes. Outcomes were compared with known clinical and histological prognostic parameters. Results Numbers of CD68+ and CD68+CD163+ macrophages in secondarily‐enucleated eyes varied widely, but was not related to the reason for enucleation. The median of CD3, CD8, FoxP3+ lymphocyte counts was 55, 99 and 9 cells/mm2, respectively. When compared to primarily‐enucleated eyes, the lymphocytic infiltration was significantly (p<.02) higher in irradiated eyes. Conclusion Numbers of T‐lymphocytes and macrophages varied widely. Irradiation has no clear effect on the number and type of macrophages in uveal melanoma. However, there were higher numbers of lymphocytes in previously irradiated uveal melanoma. [ABSTRACT FROM AUTHOR]

Purpose Uveal melanoma (UM) is the most common intra‐ocular tumor in adults that often leads to metastases for which no effective treatment is available. The aim of this study was to analyze molecular mechanisms in UM in order to reveal treatment targets. Methods Efficacy of kinase inhibitors and molecular mechanisms are analyzed in preclinical models of UM. Focus in this study was on the kinases and pathways that are associated with metastasis. Results Based on c‐Met expression in UM with a bad prognosis (monosomy 3) and activation of c‐Met in all metastasis cell lines c‐Met was chosen as treatment target and Crizotinib was chosen as candidate drug. Crizotinib is a dual kinase inhibitor that inhibits both ALK and c‐Met. Molecular analysis revealed that Crizotinib was able to inhibit c‐Met in UM effectively at nano‐molar range. Proliferation was however not affected by Crizotinib treatment when cells were grown attached to culture dishes. To achieve growth inhibition with Crizotinib cells had to be grown non‐attached. Moreover, only tumor cells that contained activated c‐Met were affected by Crizotinib while c‐Met negative cells continued to grow in the presence of the drug. Molecular analysis furthermore revealed that focal adhesion kinase (FAK) is a downstream target that was also inactivated in response to Crizotinib treatment. FAK is involved in tumor cell motility and tumor cell extravasation that are both crucial processes in metastasis. Conclusion We propose Crizotinib as a possible treatment option for metastasizing UM. As c‐Met expression is highly correlated with monosomy 3, both c‐Met and monosomy 3 may be evaluated as biomarker for Crizotinib treatment. [ABSTRACT FROM AUTHOR]

Purpose The presence of infiltrating immune cells in uveal melanoma is associated with poor prognosis. An analysis of the different functional phenotypes of the tumor‐infiltrating leukocytes (TIL) may help to gain insight in the role of these infiltrating immune cells. Methods The density of CD8+ (CD3+CD8+ T cells) and CD4+ (CD3+CD8− T cells) T lymphocytes, CD4+ regulatory T cells (Tregs; CD3+CD8‐Foxp3+ cells), CD68+ and CD68+CD163+ macrophages was evaluated by immunofluorescence histochemistry in 43 cases of uveal melanoma. The correlations between different parameters were analyzed and their presence compared to known morphologic, immunologic, cytogenetic and molecular prognostic variables. Results The presence of increased numbers of all T cell subsets was associated with an epithelioid cell type, monosomy 3, and the class 2 gene expression profile (GEP). The presence of TIL was very variable, but strong correlations were observed between the different types of TIL. The presence of Tregs was correlated with the presence of M2 macrophages. Conclusion Uveal melanoma with more malignant characteristics such as monosomy 3 and the class 2 GEP contained more TILs, which included Tregs. These data suggest that tumor‐intrinsic factors distinguishing bad from good melanoma probably control the initiation of inflammation, which involves infiltration of tumors by different lymphocytic and myeloid immune cell subtypes, and support the notion that immunosuppressive inflammation contributes to increased malignancy in high risk uveal melanoma cases. [ABSTRACT FROM AUTHOR]

Purpose Intravitreal bevacizumab, a humanized monoclonal antibody to VEGF‐A, was originally developed as an anti‐tumour treatment, and is used to treat macular edema in radiation retinopathy. As this drug may potentially be used to treat primary uveal melanoma (UM) and/or its metastases, we analyzed the effect of bevacizumab on UM growth. Methods Mice inoculated with B16F10 melanoma cells into the anterior chamber of the eye were monitored for tumour growth and vascularisation after bevacizumab treatment. UM cell proliferation and the expression of VEGF‐A, GLUT‐1, and HIF‐1α were analyzed in vitro. Results Bevacizumab treatment resulted in an acceleration of intraocular tumour growth in mice, but did not induce UM cell proliferation in vitro. Incubation with bevacizumab induced VEGF‐A and GLUT‐1 mRNA expression via the HIF‐1α pathway in UM cell lines and primary cell cultures. Surprisingly, VEGF‐A expression in mice did not result in more vessels, but we did perceive more anterior chamber hemorrhages in vivo. Conclusion Anti‐VEGF treatment with bevacizumab induces intraocular tumour growth in mice. Although bevacizumab did not induce the number of vessels in treated mice, we did observe more anterior chamber hemorrhages. One of the mechanism involved, is the induction of VEGF‐A expression in hypoxic UM cell lines and cultures through the HIF‐1α pathway, resulting in a 'pseudohypoxic' condition. This phenomenon has been described in other tumours and maybe the consequence of tumour adaptive or evasive resistance. The use of bevacizumab for treatment of macular edema (due to radiation retinopathy) after irradiation of UM should therefore be carefully considered. [ABSTRACT FROM AUTHOR]

Purpose One of the prognostically bad parameters in uveal melanoma is the presence of an inflammatory phenotype, characterized by an increased expression of HLA antigens and an immunologic infiltrate. We wondered whether the presence of specific chemokines and cytokines in the aqueous humor (AqH) from uveal melanoma‐containing eyes is associated with this inflammatory phenotype, with the presence of macrophages, and/or with survival. Methods Directly following enucleation, AqH was obtained from 37 eyes containing uveal melanoma. Samples were stored at ‐80 °C till use. Using a multiplex bead array, 15 different cytokines were measured. Determination of intratumoral macrophages was performed by immunohistochemistry and immunofluorescence. The presence of specific cytokines was compared to histopathological, genetic and clinical tumor characteristics, as well as patient survival. Results Several cytokines showed a significantly higher expression in the AqH from uveal melanoma‐containing eyes compared to the AqH from eyes undergoing cataract surgery. Only MCP‐3 was associated with the presence of macrophages and the tumor promoting M2‐type macrophage in uveal melanoma patients. Hardly any correlations were found between cytokine levels and known prognostic factors for uveal melanoma. Also, cytokine levels were not of predictive value for survival. Conclusion Although increased levels of inflammation‐related cytokines are present in the AqH of uveal melanoma‐containing eyes, hardly any associations with the presence of macrophages and their subtypes, with clinical and histopathological parameters, and prognosis were found. [ABSTRACT FROM AUTHOR]

Having physiological correct flow waveforms is a key feature for experimental studies of blood flow, especially in the process of developing and testing a new medical device such as stent, mechanical heart valve, or any implantable medical device that involves circulation of blood through the device. It is also a critical part of a perfusion system for cardiopulmonary bypass and extracorporeal membrane oxygenation procedures. This study investigated the feasibility of a novel roller pump for use in experimental flow phantoms. Flow rates of carotid flow profile measured directly with the ultrasonic flow meter matched well with the reference flow rates programmed into the machine with similarity index of 0.97 and measured versus programmed flow rates at specific time-points of peak systolic velocity (PSV): 0.894 vs 0.880, end systolic velocity (ESV): 0.333 vs 0.319, and peak diastolic velocity (PDV): 0.514 vs 0.520 L/min. Flow rates derived from video analysis of the pump motion for carotid, suprarenal, and infrarenal flows also matched well with references with similarity indices of 0.99, 0.99, and 0.96, respectively. Measured flow rates (mean/standard deviation) at PSV, ESV, and PDV time-points for carotid: 0.883/0.016 vs 0.880, 0.342/0.007 vs 0.319, and 0.485/0.009 vs 0.520; suprarenal: 3.497/0.014 vs 3.500, 0.004/0.003 vs 0, and 1.656/0.073 vs 1.453; infrarenal: 4.179/0.024 vs 4.250, -1.147/0.015 vs -1.213, and 0.339/0.017 vs 0.391 L/min, respectively. The novel roller pump is suitable for benchtop testing of physiological flow., (© 2020 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals, Inc.)