Absolute brightness of fluorescent microspheres

Lab on a Chip ◽  
2009 ◽  
Vol 9 (3) ◽  
pp. 476-478 ◽  
Author(s):  
Isaac Finger ◽  
Scott Phillips ◽  
Elizabeth Mobley ◽  
Robert Tucker ◽  
Henry Hess
Keyword(s):  
Fluorescent Microspheres ◽  
Absolute Brightness

The influence of three algal filtrates on the grazing rate of larval oysters (Crassostrea gigas), determined by fluorescent microspheres

Aquaculture ◽  
1994 ◽  
Vol 119 (2-3) ◽  
pp. 237-247 ◽  
Author(s):  
Peter A. Thompson ◽  
David J.S. Montagnes ◽  
Barbara A. Shaw ◽  
Paul J. Harrison
Keyword(s):  
Crassostrea Gigas ◽  
Grazing Rate ◽  
Fluorescent Microspheres

Abstract 4207: Comparison of 1st-Pass Myocardial Perfusion Imaging by 64-slice CT and by MRI

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Bina Ahmed ◽  
George Gentchos ◽  
Stephen P Bell ◽  
Mei Lee Frankish ◽  
Michael Jerosch-Herold ◽  
...  
Keyword(s):  
Animal Model ◽  
Perfusion Imaging ◽  
Bolus Injection ◽  
Ct Image ◽  
Gradient Echo ◽  
Fluorescent Microspheres ◽  
Axial Mode ◽  
Image Characteristics ◽  
Peak Enhancement ◽  
Ct And Mri

The purpose of this study was to compare the signal intensity (SI) and image characteristics of 1st-pass (FP) CT imaging vs. MR FP in an animal model of resting myocardial blood flow (MBF). Pigs (n=5) were scanned at rest using FP MRI perfusion imaging. Gd-DTPA was injected IV at 5cc/sec at 0.04mmol/kg. FP MR was acquired at 3T with 3 axial slices 3mm thick per R-R interval during bolus injection using a saturation recovery gradient echo sequence. ECG gated FP CT was performed immediately thereafter on a 64-slice scanner in axial mode with 10 2.5mm thick slices during bolus injection (5cc/sec) of 40% dilution of iopamidol 370. MBF was measured at rest using fluorescent microspheres between studies. SI was measured for baseline and peak myocardial enhancement phases. Contrast enhancement (CE)= (peak-baseline) SI/baseline SI X 100. Rest MBF was 0.60±0.15 ml/min/g. Temporal resolution was similar by technique but more slices were imaged by CT per R-R interval (10 vs 3) and spatial resolution was superior for FP CT. Image characteristics are shown in the table . Baseline (top) and peak enhancement (bottom) images for FP CT and MRI are shown in the figure . Results were similar when undiluted contrast was used for each modality. Despite similar absolute change in SI, CE during FP CT is markedly reduced compared to FP MR due to a more than 20-fold higher baseline SI of the myocardium.

Abstract 12555: The Dual PPAR-α/γ Agonist Aleglitazar Enhances Arteriogenesis, Angiogenesis and Endothelial Function

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Christian Werner ◽  
Stephan H Schirmer ◽  
Valerie Pavlickova ◽  
Michael Böhm ◽  
Ulrich Laufs
Keyword(s):  
Endothelial Function ◽  
Vascular Function ◽  
Daily Injection ◽  
Peroxisome Proliferator ◽  
Fluorescent Microspheres ◽  
Artery Ligation ◽  
Peroxisome Proliferator Activated Receptor ◽  
Beneficial Effects ◽  
And Function

Objective: Peroxisome proliferator-activated receptor (PPAR)-α and -γ agonists modify lipid and glucose metabolism. The aim of the study was to characterize the effects of the dual PPAR-α/γ agonist aleglitazar on endothelial function, neoangiogenesis and arteriogenesis in mice and on human endothelial progenitor cells (EPC). Methods and Results: Male C57Bl/6 wild-type (WT, normal chow) and apolipoprotein E-deficient (apoE-/-) mice on Western-type diet (WTD) were treated with aleglitazar (10 mg/kg i.p.) or vehicle by daily injection. Hindlimb ischemia was induced by right femoral artery ligation (FAL). ApoE-/- mice on WTD treated with aleglitazar before FAL were characterized by an improvement of endothelial-dependent laser Doppler perfusion (right/left foot ratio 0.40±0.03) 1 week after FAL compared to controls (R/L foot ratio 0.24±0.01; p<0.001). Collateral-dependent perfusion measured under conditions of maximal vasodilatation 1 week after FAL using fluorescent microspheres was impaired in apoE-/- on WTD compared to WT mice (R/L leg ratio in WT 78±13 vs. apoE-/- 56±6; p<0.001) and was normalized by aleglitazar treatment. Neoangiogenesis was measured in-vivo by subcutaneously implanting discs covered with cell-impermeable filters. The vascularized area of the discs was quantified after 14 days by perfusion of the animals with space-filling fluorescent microspheres. Aleglitazar increased neoangiogenesis in WT mice by 178±18% compared to vehicle (p<0.05). Endothelium-dependent relaxation of aortic rings was impaired in apoE-/- mice on WTD for 6 weeks (relaxation to 52±5% of max. contraction) compared to WT animals (relaxation to 18±5% of max. contraction) (p<0.001). Aleglitazar treatment improved endothelial function (relaxation to 39±5% of max. contraction; p<0.05). In parallel, number and function of EPC were improved in mice. Studies in human EPC showed that 1) aleglitazar’s effects were mediated by both PPAR-α and -γ signalling and Akt and 2) migration and colony forming units were up-regulated by aleglitazar in cultivated EPC from CAD patients. Conclusion: The study provides evidence for beneficial effects of the dual PPAR-α/γ agonist aleglitazar on vascular function in addition to or mediated by its metabolic actions.

scholarly journals Intraocular pressure elevation precedes a phagocytosis decline in a model of pigmentary glaucoma

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 174 ◽  
Author(s):  
Yalong Dang ◽  
Susannah Waxman ◽  
Chao Wang ◽  
Priyal Shah ◽  
Ralitsa T. Loewen ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Trabecular Meshwork ◽  
Ex Vivo ◽  
Pigment Dispersion ◽  
Pigmentary Glaucoma ◽  
Fluorescent Microspheres ◽  
Phagocytic Capacity ◽  
Pressure Transducers ◽  
Intraocular Pressure Elevation ◽  
Iop Elevation

Background: Outflow regulation and phagocytosis are key functions of the trabecular meshwork (TM), but it is not clear how the two are related in secondary open angle glaucomas characterized by an increased particle load. We hypothesized that diminished TM phagocytosis is not the primary cause of early ocular hypertension and recreated pigment dispersion in a porcine ex vivo model. Methods: Sixteen porcine anterior chamber cultures received a continuous infusion of pigment granules (Pg), while 16 additional anterior chambers served as controls (C). Pressure transducers recorded the intraocular pressure (IOP). The phagocytic capacity of the trabecular meshwork was determined by fluorescent microspheres. Results: The baseline IOPs in Pg and C were similar (P=0.82). A significant IOP elevation occurred in Pg at 48, 120, and 180 hours (all P<0.01, compared to baseline). The pigment did not cause a reduction in TM phagocytosis at 48 hours, when the earliest IOP elevation occurred, but at 120 hours onward (P=0.001 compared to C). This reduction did not result in an additional IOP increase at 120 or 180 hours compared to the first IOP elevation at 48 hours (P>0.05). Conclusions: In this porcine model of pigmentary glaucoma, an IOP elevation occurs much earlier than when phagocytosis fails, suggesting that two separate mechanisms might be at work.

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