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Copyright of Monatsschrift Kinderheilkunde is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite their ecological importance, very little is known about the taxonomy and ecology of benthic diatoms in coral-reef ecosystems. Diatom densities and community compositions were investigated in three distinct regions of the Great Barrier Reef (GBR): (a) Wet Tropics (WT), (b) Princess Charlotte Bay (PCB), and (c) the Outer Shelf (OS). About 209 taxa were observed in the GBR sediments studied, with an average abundance of 2.55 × 106 cells ml-1 in the upper 1 cm of sediment. Total diatom abundances were about twice as high in inshore reefs of PCB and WT compared with OS reefs. A redundancy analysis (RDA) of diatom composition clearly grouped the three regions separately but showed little influence of grain size, nitrogen and organic carbon content of the sediments. The only distinct correlates were inorganic carbon and the distance to the mainland associated with OS communities. Analysis of similarity (ANOSIM) of diatom community composition revealed significant differences between all three regions. Indicator values showed that most highly abundant taxa occurred in all regions. However, several taxa were clearly identified as characteristic of particular regions. It is hypothesised that variations in nutrient and light availability are the most likely explanation for the observed differences in community composition. [ABSTRACT FROM AUTHOR]

Copyright of Monatsschrift Kinderheilkunde is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Electrical stimulation of the retina using implantable devices may be one possible approach in the treatment of blindness causing progressive degeneration of the outer retina. Stimulation of ganglion cells or fibers could be achieved by epiretinal positioning of a microelectrode array as one component of a retinal prosthesis. Experiments were performed in rabbits to determine whether it is possible to elicit cortical responses with current pulses delivered via an epiretinal placed microelectrode array. Methods: Polyimide-based microelectrode arrays with platinum electrodes and silicon-based TiN electrode arrays were implanted and placed onto the retinal surface of healthy pigmented rabbits after vitrectomy. The devices were temporarily fixated under PFCL and connected to constant current sources delivering bi- or monophasic current pulses. Cortical evoked potentials were recorded using subcutaneously implanted EEG electrodes over the visual cortex. Results: The surgical procedures for implantation and fixation could be performed without serious complications. The electrode array could be placed in the area of the visual streak. Cortical potentials could be recorded after pulse train stimulation either with biphasic or with monophasic pulses. At threshold, pulses of 10 µA/phase and 100 µs/phase were necessary for detection of an electrically evoked cortical potential (EEP). Charge delivery at threshold varied between 0.1 and 0.3 nC/phase and charge densities varied between 1 and 12 µC/cm2. The EEP amplitude increased with increasing stimulus strength. The cortical response could be completely blocked with a retrobulbar injection of 4 ml lidocaine 2%. Conclusion: Constant current pulses delivered via Retina Stimulator devices equipped either with platinum electrodes or with TiN electrodes placed onto the inner retinal surface were able to elicit cortical potentials in the rabbit visual system. At threshold the charge delivery seems to be in a safe range. [ABSTRACT FROM AUTHOR]

Vitronectin, an integrinbinding a-l-glycoprotein with potent cell-adhesion and proliferation-mediating properties, has been shown to be incorporated in surgically removed membranes from patients with proliferative vitreoretinopathy (PVR), proliferative diabetic retinopathy (PDR) and macular pucker. Therefore we developed an ELISA technique to quantify levels of vitronectin in human vitreous and plasma samples in order to be able to evaluate the significance of vitronectin in these different vitreoretinal diseases. Our results indicate a significant increase of vitronectin in all proliferative disorders except idiopathic macular pucker. Adjustment of all probes to equal total protein content yielded a significant increase only in PDR (type 11 diabetes). Plasma samples demonstrated a significant increase of vitronectin in patients with type Il diabetes suffering from PDR. Therefore, break-down of the blood-retina barrier appears to be the most likely explanation for the increased levels of vitronectin in the vitreous. Our results indicate that vitronectin may not only be involved in the regulation of epiretinal membrane formation at significantly higher levels in patients with type II diabetes, but the increase of vitronectin in diabetic plasma may also help to explain the pathological alteration of the coagulation cascade in diabetics. [ABSTRACT FROM AUTHOR]

Proliferative vitreoretinopathy (PVR), the most severe complication of retinal detachment surgery and posterior segment ocular trauma, is characterized by the intraocular proliferation of non-neoplastic cells with formation of vitreal and periretinal membranes resulting in renewed traction retinal detachment. As retinal pigment epithelial (RPE) cells have been shown to play an essential role in the development of PVR, we investigated the acute and chronic effects of daunomycin on the morphology and viability of porcine RPE cells in vitro. The intense and complete inhibition of cell proliferation reported in this study adds to previous evidence that daunomycin may be useful for pharmacological treatment of human PVR. [ABSTRACT FROM AUTHOR]

Eight eyes were examined histologically after silicone oil injection. Intraretinal deposits suggestive of silicone were not present in attached retinas, but were frequently observed in detached retinas when subretinal silicone occurred. This may possibly be due to defects in the horizontal conducting structures of the retina such as those occurring in persistent detachment with disorganization of the retina. Morphologically, the retina was essentially normal 3.5 years after the silicone injection. This observation contradicts the idea that silicone oil has a toxic effect. [ABSTRACT FROM AUTHOR]

Perforating and penetrating globe injuries secondary to peribulbar and retrobulbar anaesthesia are often complicated by vitreous haemorrhage and retinal detachment. We describe the effectiveness of primary silicone oiltamponade in the repair of three perforatedglobes secondary to local anaesthesia for ophthalmic surgery. Three patients with axial myopia had peribulbar and retrobulbar anaesthesia for extracapsular cataract extraction (two patients) and cryotherapy (one patient). All eyes sustained a vitreous haemorrhage obscuring the view to the fundus. Retinal detachments were detected by B-scan ultrasound. In all eyes, scleral buckling, pars plana vitrectomy and silicone oil tamponade were performed as a primary surgical procedure. All the patients had complete anatomic reposition. In two patients, after two years follow-up, visual acuity was between 6/12to 6/36 with the retina attached and no proliferative vitreoretinopathy (PVR). The third patient had blind painful eye and enucleation was performed. Primary use of silicone oil tamponade, in the management of perforated globe with retinal detachment due to local anaesthesia injection, is recommended. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Kinderheilkunde is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Monatsschrift Kinderheilkunde is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bei der proliuferativen Vitreoretinopathie (PVR) führt der Zusammenbruch vitreoretinaler Grenzstrukturen durch Amotio, perforierende Traumen oder chirurgische Eingriffe zu einer überschießenden regenerativen zellulären Aktivität mit Ausbildung vitreoretinaler Traktionsmembranen. Die Exsudation von Plasma und Thrombozyten als wesentliches pathogenetisches Ereignis bei der PVR-Entstehung wird durch eine Umgehung der physiologischen Blut-Retina-Schranke und Blut-Glaskörper-Schranke ermöglicht. Bei der Untersuchung der Bedeutung einzelner biochemischer Faktoren in der PVR-Genese läßt sich der Einfluß der Integrität der Blut-Retina-Schranke nur durch kompliziertere Nachweismethoden abschätzen. Ziel solcher Untersuchungen ist die Unterscheidung lokaler okulärer Prozesse von systemischen Einflüssen, die dann wiederum einer differenzierten, spezifischen Therapie zugeführt werden sollen. Proliferative vitreoretinopathy (PVR) is characterized by massive regenerative cellular activity with formation of vitreoretinal traction membranes. This disease process is initiated by rhegmatogenous retinal detachment, posterior segment ocular trauma, and previous vitreoretinal surgery. Exudation of plasma and platelets, a major pathogenetic event in PVR, is caused by defects of blood retinal barrier and blood vitreous barrier function. The role of blood retinal barrier integrity with regard to the significance of single biochemical factors in PVR can only be estimated by complex biochemical analyses using multiple laboratory techniques. Differential therapeutic approaches, however, will only be optimized if local processes in PVR can be distinguished from systemic influences derived from blood retinal barrier dysfunction. [ABSTRACT FROM AUTHOR]

• Purpose: To determine the effectiveness of autologous platelets in repair of optic disc pit associated with persistent macular detachment. • Patient: We report on a 44-year-old woman with optic disc pit associated with persistent macular detachment. The patient underwent an uneventful pars plana vitrectomy with autologous platelets injected over the optic disc pit. Good anatomical and functional results were obtained. • Conclusion: This surgical approach may be a valuable adjunct to the surgical management of optic disc pit associated with persistent macular detachment. [ABSTRACT FROM AUTHOR]

Proliferative vitreoretinopathy (PVR), the major complication of rhegmatogenous retinal detachment and posterior segment ocular trauma, is a multistage disease process eventually resulting in traction retinal detachment. The migration of macrophages to a site of disrupted barriers between the vitreous, retina, and choroidea, respectively, is considered to be an important step in the early pathogenesis of PVR. In this study, we demonstrate the presence of numerous mononuclear phagocytes in a human PVR membrane by an APAAP (alkaline phosphatase - anti-alkaline phosphatase) immunostain using a monoclonal mouse anti-human macrophage antibody. This finding correlates with a highly positive fibronectin immunostain in the same specimen. Our results warrant further investigation of the involvement of mononuclear phagocytes in vitreoretinal proliferative disorders. [ABSTRACT FROM AUTHOR]