| 1. |
- Aibinu, A.M., et al.
(författare)
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Vascular intersection detection in retina fundus images using a new hybrid approach
- 2010
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Ingår i: Computers in Biology and Medicine. - : Elsevier. - 0010-4825 .- 1879-0534. ; 40:1, s. 81-89
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Tidskriftsartikel (refereegranskat)abstract
- The use of vascular intersection aberration as one of the signs when monitoring and diagnosing diabetic retinopathy from retina fundus images (FIs) has been widely reported in the literature. In this paper, a new hybrid approach called the combined cross-point number (CCN) method able to detect the vascular bifurcation and intersection points in FIs is proposed. The CCN method makes use of two vascular intersection detection techniques, namely the modified cross-point number (MCN) method and the simple cross-point number (SCN) method. Our proposed approach was tested on images obtained from two different and publicly available fundus image databases. The results show a very high precision, accuracy, sensitivity and low false rate in detecting both bifurcation and crossover points compared with both the MCN and the SCN methods.
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| 2. |
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| 3. |
- Berglund, Lisa, et al.
(författare)
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Nuclear Factor of Activated T Cells Regulates Osteopontin Expression in Arterial Smooth Muscle in Response to Diabetes-Induced Hyperglycemia
- 2010
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Ingår i: ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY. - Baltimore : Lippincott Williams & Wilkins. - 1079-5642. ; 30, s. 154-218
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Tidskriftsartikel (refereegranskat)abstract
- Objective-Hyperglycemia is a recognized risk factor for cardiovascular disease in diabetes. Recently, we reported that high glucose activates the Ca2+/calcineurin-dependent transcription factor nuclear factor of activated T cells (NFAT) in arteries ex vivo. Here, we sought to determine whether hyperglycemia activates NFAT in vivo and whether this leads to vascular complications. Methods and Results-An intraperitoneal glucose-tolerance test in mice increased NFATc3 nuclear accumulation in vascular smooth muscle. Streptozotocin-induced diabetes resulted in increased NFATc3 transcriptional activity in arteries of NFAT-luciferase transgenic mice. Two NFAT-responsive sequences in the osteopontin (OPN) promoter were identified. This proinflammatory cytokine has been shown to exacerbate atherosclerosis and restenosis. Activation of NFAT resulted in increased OPN mRNA and protein in native arteries. Glucose-induced OPN expression was prevented by the ectonucleotidase apyrase, suggesting a mechanism involving the release of extracellular nucleotides. The calcineurin inhibitor cyclosporin A or the novel NFAT blocker A-285222 prevented glucose-induced OPN expression. Furthermore, diabetes resulted in higher OPN expression, which was significantly decreased by in vivo treatment with A-285222 for 4 weeks or prevented in arteries from NFATc3(-/-) mice. Conclusions-These results identify a glucose-sensitive transcription pathway in vivo, revealing a novel molecular mechanism that may underlie vascular complications of diabetes.
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| 4. |
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| 5. |
- Butt, Naveed R., et al.
(författare)
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An Improved Classification Scheme for Standoff Detection of Explosives via Raman Spectroscopy
- 2010
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Konferensbidrag (refereegranskat)abstract
- Raman spectroscopy is a laser-based vibrational tech- nique that can provide spectral signatures unique to a multitude of compounds. The technique is gaining widespread interest as a method for detecting hidden explosives due to its sensitivity and ease of use. In this work, we present a computationally e±cient clas- si¯cation scheme for accurate stando® identi¯cation of several common explosives using visible-range Raman spectroscopy. Using real measurements, we evaluate and modify a recent correlation-based approach to classify Raman spectra from various both harmful and commonplace substances. The results show that the proposed approach can, at a distance of 30 me- ters, or more, successfully classify measured Raman spectra from several explosive substances, including Nitromethane, TNT, DNT, Hydrogen Peroxide, TATP and Ammonium Nitrate.
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| 6. |
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| 7. |
- Diehl, Carl, et al.
(författare)
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Protein Flexibility and Conformational Entropy in Ligand Design Targeting the Carbohydrate Recognition Domain of Galectin-3.
- 2010
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 132, s. 14577-14589
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Tidskriftsartikel (refereegranskat)abstract
- Rational drug design is predicated on knowledge of the three-dimensional structure of the protein-ligand complex and the thermodynamics of ligand binding. Despite the fundamental importance of both enthalpy and entropy in driving ligand binding, the role of conformational entropy is rarely addressed in drug design. In this work, we have probed the conformational entropy and its relative contribution to the free energy of ligand binding to the carbohydrate recognition domain of galectin-3. Using a combination of NMR spectroscopy, isothermal titration calorimetry, and X-ray crystallography, we characterized the binding of three ligands with dissociation constants ranging over 2 orders of magnitude. (15)N and (2)H spin relaxation measurements showed that the protein backbone and side chains respond to ligand binding by increased conformational fluctuations, on average, that differ among the three ligand-bound states. Variability in the response to ligand binding is prominent in the hydrophobic core, where a distal cluster of methyl groups becomes more rigid, whereas methyl groups closer to the binding site become more flexible. The results reveal an intricate interplay between structure and conformational fluctuations in the different complexes that fine-tunes the affinity. The estimated change in conformational entropy is comparable in magnitude to the binding enthalpy, demonstrating that it contributes favorably and significantly to ligand binding. We speculate that the relatively weak inherent protein-carbohydrate interactions and limited hydrophobic effect associated with oligosaccharide binding might have exerted evolutionary pressure on carbohydrate-binding proteins to increase the affinity by means of conformational entropy.
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| 8. |
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| 9. |
- Fagman, Henrik, 1975, et al.
(författare)
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Morphogenesis of the thyroid gland.
- 2010
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Ingår i: Molecular and cellular endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 323:1, s. 35-54
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Forskningsöversikt (refereegranskat)abstract
- Congenital hypothyroidism is mainly due to structural defects of the thyroid gland, collectively known as thyroid dysgenesis. The two most prevalent forms of this condition are abnormal localization of differentiated thyroid tissue (thyroid ectopia) and total absence of the gland (athyreosis). The clinical picture of thyroid dysgenesis suggests that impaired specification, proliferation and survival of thyroid precursor cells and loss of concerted movement of these cells in a distinct spatiotemporal pattern are major causes of malformation. In normal development the thyroid primordium is first distinguished as a thickening of the anterior foregut endoderm at the base of the prospective tongue. Subsequently, this group of progenitors detaches from the endoderm, moves caudally and ultimately differentiates into hormone-producing units, the thyroid follicles, at a distant location from the site of specification. In higher vertebrates later stages of thyroid morphogenesis are characterized by shape remodeling into a bilobed organ and the integration of a second type of progenitors derived from the caudal-most pharyngeal pouches that will differentiate into C-cells. The present knowledge of thyroid developmental dynamics has emerged from embryonic studies mainly in chicken, mouse and more recently also in zebrafish. This review will highlight the key morphogenetic steps of thyroid organogenesis and pinpoint which crucial regulatory mechanisms are yet to be uncovered. Considering the co-incidence of thyroid dysgenesis and congenital heart malformations the possible interactions between thyroid and cardiovascular development will also be discussed.
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| 10. |
- Fagman, Henrik, 1975, et al.
(författare)
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Morphogenetics of early thyroid development.
- 2010
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Ingår i: Journal of molecular endocrinology. - 1479-6813.
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Forskningsöversikt (refereegranskat)abstract
- The thyroid develops from the foregut endoderm. Yet uncharacterized inductive signals specify endoderm progenitors to a thyroid cell fate that assemble in the pharyngeal floor from which the primordium buds and migrates to the final position of the gland. The morphogenetic process is regulated by both cell-autonomous (activated by e.g. Nkx2-1, Foxe1, Pax8 and Hhex) and mesoderm-derived (mediated by e.g. Tbx1 and Fgf) mechanisms acting in concert to promote growth and survival of progenitor cells. The developmental role of thyroid-stimulating hormone is limited to thyroid differentiation set to work after the gross anatomy of the gland is already sculptured. This review summarizes recent advances on the molecular genetics of thyroid morphogenesis put into context of endoderm developmental traits and highlights established and potentially novel mechanisms of thyroid dysgenesis of relevance to congenital hypothyroidism in man.
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