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Areas Devoid (area + devoid)
Selected Abstracts2112: AO imaging of acute macular diseasesACTA OPHTHALMOLOGICA, Issue 2010M PAQUES Purpose To show clinical cases of acute macular diseases and their follow-up by adaptive optics flood imaging. Methods Cases of acute retinal ischemia, of acute macular neuroretinopathy, of photic injury and of poppers-related retinopathy have been observed by a prototypic adaptive optics flood imaging (ImagineEye corporation). Images from follow-up examinations have been registered in order to obtain retinal monitoring at the single photoreceptor level. Iamges were compared to high resolution OCT scans. Results Precise extension and progression/regression of lesions could be documented in all cases. Acute macular neuroretinopathy showed residual cones persisting within an area devoid of any detectable cone. Minute progression and regression of lesions could be documented. Acute ischemia of the inner retina due to central retinal vein occlusion resulted in focal masking of the cone mosaic. The cone mosaic reappeared during follow-up. Photic injury showed no changes over a 1 year follow-up. Images of poppers-related retinopathy showed partial improvement over time. Conclusion Adaptive optics flood imaging allows documentation of the extension and progression of acute maculopathies of various origins. [source] Regional-specific regulation of BDNF and trkB correlates with nigral dopaminergic cell sprouting following unilateral nigrostriatal axotomyJOURNAL OF NEUROSCIENCE RESEARCH, Issue 9 2008J. T. García Navia Abstract Axotomy is a powerful stimulus of axon growth and plastic changes. We investigated the potential role of BDNF/trkB signaling in the sprouting of dopaminergic nigral axons in response to axotomy of the medial forebrain bundle. Tyrosine hydroxylase immunohistochemistry revealed the existence of sprouting mechanisms in the axotomized substantia nigra (SN). Time-course changes of trkB mRNA expression demonstrated a robust increase in an area projecting from the rostral tip of the SN to the glial scar, which coincided with evidence of nigral dopaminergic sprouting. In addition, we found an early loss of this messenger in areas related to the knife cut, which recovered by 7 days postlesion. TrkB down-regulation appeared to be associated to the lesion-induced local damage, as it was restricted to an area showing Fluoro-Jade B, and TUNEL positive cells. In trkB-depleted areas, an inverse correlation between mRNA expressions of BDNF and trkB was apparent. Specific induction of BDNF mRNA was mostly seen in border of areas devoid of trkB mRNA. In contrast, in the areas exhibiting trkB mRNA expression, no BDNF mRNA was detected. We suggest that trkB levels could be a determinant element in regulating BDNF expression. Finally, the search for molecules involved in either promoting or inhibiting axonal growth, demonstrated up-regulation of GAP-43 and Nogo-A mRNA at sites close to the knife transections as early as 1 day postlesion. However, overall, Nogo-A induction was more robust than that seen for GAP-43. © 2008 Wiley-Liss, Inc. [source] Reactive changes of interstitial glia and pinealocytes in the rat pineal gland challenged with cell wall components from gram-positive and -negative bacteriaJOURNAL OF PINEAL RESEARCH, Issue 1 2005Ya Fen Jiang-Shieh Abstract:, Lipopolysaccharide (LPS), the major proinflammatory component of gram-negative bacteria, is well known to induce sepsis and microglial activation in the CNS. On the contrary, the effect of products from gram-positive bacteria especially in areas devoid of blood,brain barrier remains to be explored. In the present study, a panel of antibodies, namely, OX-6, OX-42 and ED-1 was used to study the response of microglia/macrophages in the pineal gland of rats given an intravenous LPS or lipoteichoic acid (LTA). These antibodies recognize MHC class II antigens, complement type 3 receptors and unknown lysosomal proteins in macrophages, respectively. In rats given LPS (50 ,g/kg) injection and killed 48 h later, the cell density and immunoexpression of OX-6, OX-42 and ED-1 in pineal microglia/macrophages were markedly increased. In rats receiving a high dose (20 mg/kg) of LTA, OX-42 and OX-6, immunoreactivities in pineal microglia/macrophages were also enhanced, but that of ED-1 was not. In addition, both bacterial toxins induced an increase in astrocytic profiles labelled by glial fibrillary acid protein. An interesting feature following LPS or LTA treatment was the lowering effect on serum melatonin, enhanced serotonin immunolabelling and cellular vacuolation as studied by electron microscopy in pinealocytes. The LPS- or LTA-induced vacuoles appeared to originate from the granular endoplasmic reticulum as well as the Golgi saccules. The present results suggest that LPS and LTA could induce immune responses of microglia/macrophages and astroglial activation in the pineal gland. Furthermore, the metabolic and secretory activity of pinealocytes was modified by products from both gram-positive and -negative bacteria. [source] Formation of platelet strings and microthrombi in the presence of ADAMTS-13 inhibitor does not require P-selectin or ,3 integrinJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2007A. K. CHAUHAN Summary. Background:,Ultra-large von Willebrand factor (ULVWF) and the receptor P-selectin are released from endothelial Weibel,Palade bodies during injury or inflammation. VWF mediates platelet adhesion and P-selectin promotes leukocyte rolling. ADAMTS-13 limits the duration of platelet adhesion by cleaving the ULVWF. In the absence of ADAMTS-13, long VWF filaments decorated with platelets form. Recent in vitro studies suggested that P-selectin might anchor these platelet strings to endothelium, but whether the same mechanism exists in vivo remains to be elucidated. Methods:,We address the role of P-selectin and ,3 integrin in platelet string formation in vivo using intravital microscopy by infusing inhibitory ADAMTS-13 antibody in P-selectin-/- and ,3 -deficient mice and activating the endothelium by injecting histamine. Results:,We show that inhibition of ADAMTS-13 combined with endothelial activation leads to similar extents of platelet string formation in wild-type, P-selectin- and integrin ,3 -deficient mice. Further, in venules the platelet strings can coalesce into VWF-platelet aggregates. This process utilizes neither the platelet ,3 integrin nor P-selectin. We also show in vitro that platelets can act as a bridge between the VWF fibers and that VWF can self-associate even in areas devoid of platelets. Conclusions:,The formation or retention of the platelet strings does not require P-selectin or the endothelial VWF receptor ,v,3. Furthermore, in the presence of low ADAMTS-13 activity, VWF-dependent and ,IIb,3 -independent platelet clustering occurs in veins, as has been shown at high arterial shear rates. Our study further supports the importance of regulation of VWF multimer size upon secretion from Weibel,Palade bodies. [source] | |||||||||||||