Retinal Redox Stress and Remodeling in Cardiometabolic Syndrome and Diabetes

Diabetic retinopathy (DR) is a significant cause of global blindness; a major cause of blindness in the United States in people aged between 20–74. There is emerging evidence that retinopathy is initiated and propagated by multiple metabolic toxicities associated with excess production of reactive oxygen species (ROS). The four traditional metabolic pathways involved in the development of DR include: increased polyol pathway flux, advanced glycation end-product formation, activation of protein kinase Cisoforms and hexosamine pathway flux. These pathways individually and synergisticallycontribute to redox stress with excess ROS resulting in retinal tissue injury resulting in significant microvascular blood retinal barrier remodeling. The toxicity of hyperinsulinemia, hyperglycemia, hypertension, dyslipidemia, increased cytokines and growth factors, in conjunction with redox stress, contribute to the development and progression of DR. Redox stress contributes to the development and progression of abnormalities of endothelial cells and pericytes in DR. This review focuses on the ultrastructural observations of the blood retinal barrier including the relationship between the endothelial cell and pericyte remodeling in young nine week old Zucker obese (fa/ fa) rat model of obesity; cardiometabolic syndrome, and the 20 week old alloxan induced diabetic porcine model. Preventing or delaying the blindness associated with these intersecting abnormal metabolic pathways may be approached through strategies targeted to reduction of tissue inflammation and oxidative—redox stress. Understanding these abnormal metabolic pathways and the accompanying redox stress and remodeling mayprovide both the clinician and researcher a new concept of approaching this complicated disease proces

Characterization and Design of a Readout Circuit for a Piezoelectric-based Acoustic Disdrometer

In 2009, Department of Water Management (DWM) at TU Delft conceptualized the design of a low-cost disdrometer suitable for large scale, remote deployment. But, being a novel idea, its electrical characteristics were not well researched. Also, the system was not sensitive enough to measure the raindrops of diameter less than 0.9mm. Furthermore, it was found that the proposed disdrometer suffers from the edge effect i.e. when a raindrop hits on the edge of the disdrometer; the size of the raindrop is underestimated. All the aforementioned issues have been addressed in this research. The presented work discusses the electrical characteristics of the disdrometer. A readout circuit has been designed to improve the performance of the disdrometer and an innovative technique has been developed to solve the problem of edge effect. The impedance response of the disdrometer has been analyzed and an equivalent electrical model of the proposed disdrometer has been developed and characterized. Furthermore, an elaborative analysis of the edge effect has been presented. Based on this analysis, an innovative technique has been proposed for reducing the edge-effect. This technique uses the envelope of the transducer’s output to determine if the drop hit on edge. Also, a low-power (17.8mA@5V), low-noise (7.8µVrms) readout circuit has been designed. This readout circuit is able to measure the drops of size as low as 0.4mm. Because of the achieved results, this disdrometer is attracting a lot of attention of various groups from industry as well as from academia. A group of researchers from the DWM, TU Delft is looking forward to turn it in to a commercial product.Electronic InstrumentationMicroelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc

Qualitative analysis of Fruits and Vegetables using Earth’s Field Nuclear Magnetic Resonance (EFNMR) and Magnetic Resonance Imaging (MRI)

Among the imaging techniques, magnetic resonance imaging (MRI) is a non-contact and a non-invasive technique to obtain images of the objects rich in water content and provides an excellent tool to study variation of contrast among the soft issues. It often utilizes a linear magnetic field gradient to obtain an image that combines the visualization of molecular structure and dynamics. It measures the characteristics of hydrogen nuclei of water and nuclei with similar chemical shifts, modified by chemical environment across the object. In the present work, MRI of fresh tomatoes has been recorded using Terranova-MRI for qualitative analysis. The technique is effective, powerful and reliable as an investigative tool in the quality analysis and diagnosis of infections in fruits and vegetables

Pericytopathy: Oxidative Stress and Impaired Cellular Longevity in the Pancreas and Skeletal Muscle in Metabolic Syndrome and Type 2 Diabetes

The pericyte's role has been extensively studied in retinal tissues of diabetic retinopathy; however, little is known regarding its role in such tissues as the pancreas and skeletal muscle. This supportive microvascular mural cell plays an important and novel role in cellular and extracellular matrix remodeling in the pancreas and skeletal muscle of young rodent models representing the metabolic syndrome and type 2 diabetes mellitus (T2DM). Transmission electron microscopy can be used to evaluate these tissues from young rodent models of insulin resistance and T2DM, including the transgenic Ren2 rat, db/db obese insulin resistantߞT2DM mouse, and human islet amyloid polypeptide (HIP) rat model of T2DM. With this method, the earliest pancreatic remodeling change was widening of the islet exocrine interface and pericyte hypercellularity, followed by pericyte differentiation into islet and pancreatic stellate cells with early fibrosis involving the islet exocrine interface and interlobular interstitium. In skeletal muscle there was a unique endothelial capillary connectivity via elongated longitudinal pericyte processes in addition to pericyte to pericyte and pericyte to myocyte cellcell connections allowing for paracrine communication. Initial pericyte activation due to moderate oxidative stress signaling may be followed by hyperplasia, migration and differentiation into adult mesenchymal cells. Continued robust oxidative stress may induce pericyte apoptosis and impaired cellular longevity. Circulating antipericyte autoantibodies have recently been characterized, and may provide a screening method to detect those patients who are developing pericyte loss and are at greater risk for the development of complications of T2DM due to pericytopathy and rarefaction. Once detected, these patients may be offered more aggressive treatment strategies such as early pharmacotherapy in addition to lifestyle changes targeted to maintaining pericyte integrity. In conclusion, we have provided a review of current knowledge regarding the pericyte and novel ultrastructural findings regarding its role in metabolic syndrome and T2DM

En-block resection of a giant retroperitoneal lipoma presented as huge abdominal swelling: a case report

Retroperitoneal lipomas are an extremely rare entity with only less than 20 cases described in the literature so far. They can attain immoderate size due to space provided in the retroperitoneum and cause abdominal symptoms like abdominal pain, swelling and obstipation due to mass effect. Case presented here as of 53 years old male with complaint of abdominal swelling that had been progressive for the last 1 year. On computed tomography (CT) it revealed giant retroperitoneal mass? liposarcoma? occupying the space immensely. Intraoperatively, two giant retroperitoneal tumours were found which did not show any features of infiltration to nearby structures, therefore the sole tumour annihilation was achieved, which was diagnosed as benign lipoma on histopathology report later. The most important differential diagnosis is the well differentiated liposarcoma, which could only be confirmed after resection and histopathological assessment. Retroperitoneal lipomas are clearly not distinguishable from well differentiated liposarcomas on CT guided and USG guided biopsy and thus it could be misleading. Hence surgical resection with negative margins along with histopathological confirmation is treatment of choice with regular follow up to diagnose early recurrence if any.</jats:p