Molecular regulation of vascular endothelial growth factor expression in the retinal pigment epithelium

Purpose: Vascular endothelial growth factor (VEGF) plays an important role in homeostasis and diseases of the retinal pigment epithelium (RPE), choriocapillaris, and, most notably, age-related macular degeneration (AMD). Although much is known about VEGF regulation in pathologies, little is known about the control of VEGF expression under normal conditions. VEGF expression has been previously shown to be regulated in coordination with cell differentiation in the muscle and kidney. We therefore tested the hypothesis that VEGF in the adult RPE would similarly be regulated in conjunction with differentiation. Methods: A human retinal pigment epithelium cell line (ARPE-19), a line of immortalized human RPE cells, was used for all experiments. RPE cells were polarized in culture for 4 weeks on laminin-coated Transwells. Levels of VEGF mRNA and protein were determined with real-time PCR and enzyme-linked immunosorbent assay, respectively. VEGF-luciferase reporter constructs were used to identify regions of the VEGF promoter that control VEGF expression in the RPE. Microphthalmia-associated transcription factor (MITF)-Tfe transcription factors were blocked using either a pan MITF-Tfe dominant negative or specific small interfering RNA (siRNA). Results: VEGF mRNA and protein secretion increased over time in the RPE cells cultured on Transwells, with protein secretion occurring in a polarized fashion primarily toward the basolateral side. Overexpression of a dominant negative that targets the MITF-Tfe family resulted in a 50% reduction in VEGF expression. The role of the MITF-Tfe family in VEGF regulation in the RPE was corroborated in studies with the VEGF-luciferase reporter constructs, where deletion of the distal VEGF promoter region containing putative binding sites for the MITF-Tfe family resulted in a 50% reduction in VEGF promoter activity. siRNA knockdown of the MITF-Tfe family individually, and in combination, revealed that downregulation of Tfe3 resulted in reduced VEGF expression. Conclusions: Our results indicate that Tfe3, in conjunction with other MITF-Tfe members, regulates VEGF expression in the RPE and are consistent with the hypothesis that VEGF expression in RPE cells is regulated as part of their differentiation

MODELLING OF POWDER FLOW IN ROTATIONAL MOULDING

Rotational moulding is a widely used technological process to obtain hollow plastic articles, in which polymer powders melt within a rotating mould. The first step in modelling the melting process is to analyse the kinematics of the powder in the rotating system. To this goal, a series of experimental observations was performed on a rotating cylinder partially filled with a powder (Sand X, average size 460 microns) with known physical characteristics (such as angles of repose and angles of approach). A phenomenological model was then developed, based on the assumption that the powder behaves as a Bingham-plastic fluid, obtaining theoretical predictions which were in good agreement with the experimental measurements

Preparation and Using Phantom Lesions to Practice Fine Needle Aspiration Biopsies

Currently, health workers including residents and fellows do not have a suitable phantom model to practice the fine- needle aspiration biopsy (FNAB) procedure. In the past, we standardized a model consisting of latex glove containing fresh cattle liver for practicing FNAB. However, this model is difficult to organize and prepare on short notice, with the procurement of fresh cattle liver being the most challenging aspect. Handling of liver with contamination-related problems is also a significant draw back. In addition, the glove material leaks after a few needle passes, with resulting mess. We have established a novel simple method of embedding a small piece of sausage or banana in a commercially available silicone rubber caulk. This model allows the retention of vacuum seal and aspiration of material from the embedded specimen, resembling an actual FNAB procedure on clinical mass lesions. The aspirated material in the needle hub can be processed similar to the specimens procured during an actual FNAB procedure, facilitating additional proficiency in smear preparation and staining. View accompanying video at http://www.jove.com/details.php?id=1404

Controlled Release of Drugs fromMicroparticles Produced by Ultrasonic Assisted Atomization Based on Biocompatible Polymers

Microencapsulation of active molecules in biocompatible polymers is a matter of great interest in pharmaceutical sciences. Ultrasonic assisted atomization as a new technique to produce microencapsulated systems seems to offer several advantages (low level of mechanical stress in materials, reduced energy request, reduced apparatuses size) with respect to more conventional techniques. In this work, fine drug-loaded particles were produced by ionic reticulation of droplets obtained by ultrasonic atomization of biopolymers solutions. The particles were then characterized in terms of morphology and drug release kinetics. Data were used to estimate the PNMS (Polymeric Network Mesh-Size) with the aims of clarifying its role in controlled drug release, and analyzing its relationships with material and process parameters. For materials and operative conditions investigated, the calculated PNMS was found consistent with a fast release of drugs of small molecular size

The Challenge of Onboard SAR Processing: A GPU Opportunity

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Migraine with aura in the locker room: three case reports

It is well known that physical activity can aggravate the intensity of the headache, but the pathophysiological relationship between exertion and aura is still unknown. Anecdotal reports describe episodes of migraine preceded by head trauma and visual symptoms, migraine prodrome symptoms after unusually strenuous running with no subsequent head pain or recurrent attacks of hemiplegic migraine induced only by exertion. We describe the cases of three young men with recurrent episodes of migraine with aura occurring in the locker room shortly after a football match. Since the symptoms could mimic important pathologies in approximately 10% of these of headaches, it was mandatory to exclude a secondary form of headache in these patients. Several theories exist regarding the cause of primary exertional headache, but the pathogenesis of migraine triggered by physical activity has still not been identified. The present International Classification of Headache Disorders does not mention sport/exercise-induced migraine with aura episodes as primary headache. Since there are many cases described in the literature of migraine with aura triggered only by exercise, it may be helpful to specify, in the typical aura with migraine headache comments, that in some cases it can be exclusively triggered by sport/exercise

Pathology and molecular analysis of ' Hapalotrema mistroides ' (Digenea: Spirorchiidae) infecting a Mediterranean loggerhead turtle ' Caretta caretta '

Turtle blood flukes belonging to the family Spirorchiidae (Digenea) represent a major threat for sea turtle health and are considered the most important parasitic cause of turtle stranding and mortality worldwide. Despite the large diversity of spirorchiid species found globally, there are only 2 records for free-ranging Mediterranean sea turtles that date back to the late 1800s involving just Hapalotrema mistroides Monticelli, 1896. This study describes the first fatal confirmed case of spirorchiidiasis in a free-ranging Mediterranean loggerhead turtle Caretta caretta (Linnaeus) and, owing to the complexities of taxonomic identification of these parasites, provides the first molecular characterization and phylogenetic analysis of H. mistroides from the Mediterranean Sea. The loggerhead turtle showed cachexia and digestive disorders associated with severe damage to the pancreas and intestinal ganglia, caused by deposition of Hapalotrema eggs forming granulomas. Massive Hapalotrema egg emboli in several tissues and organs and encephalitis were the most probable contributions to the death of the turtle. The congruence between the phylogenetic analysis of both the ITS2 and 28S rDNA resolved the Italian and USA H. mistroides as the same species, confirming the parasite identification. The case here described clearly indicates that the blood flukes should be considered in the differential diagnosis of Mediterranean sea turtle diseases