180 research outputs found

    New Target Genes for the Peroxisome Proliferator-Activated Receptor-Ī³ (PPARĪ³) Antitumour Activity: Perspectives from the Insulin Receptor

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    The insulin receptor (IR) plays a crucial role in mediating the metabolic and proliferative functions triggered by the peptide hormone insulin. There is considerable evidence that abnormalities in both IR expression and function may account for malignant transformation and tumour progression in some human neoplasias, including breast cancer. PPARĪ³ is a ligand-activated, nuclear hormone receptor implicated in many pleiotropic biological functions related to cell survival and proliferation. In the last decade, PPARĪ³ agonistsā€”besides their known action and clinical use as insulin sensitizersā€”have proved to display a wide range of antineoplastic effects in cells and tissues expressing PPARĪ³, leading to intensive preclinical research in oncology. PPARĪ³ and activators affect tumours by different mechanisms, involving cell proliferation and differentiation, apoptosis, antiinflammatory, and antiangiogenic effects. We recently provided evidence that PPARĪ³ and agonists inhibit IR by non canonical, DNA-independent mechanisms affecting IR gene transcription. We conclude that IR may be considered a new PPARĪ³ ā€œtargetā€ gene, supporting a potential use of PPARĪ³ agonists as antiproliferative agents in selected neoplastic tissues that overexpress the IR

    A Proposed Grading System to Standardize the Description of Renal Papillary Appearance at the Time of Endoscopy in Patients with Nephrolithiasis

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    BACKGROUND AND PURPOSE: The appearance of the renal papillae in patients with nephrolithiasis can be quite variable and can range from entirely healthy to markedly diseased. The implications of such findings remain unknown. One potential reason is the lack of a standardized system to describe such features. We propose a novel grading scale to describe papillary appearance at the time of renal endoscopy. METHODS: Comprehensive endoscopic renal assessment and mapping were performed on more than 300 patients with nephrolithiasis. Recurring abnormal papillary characteristics were identified and quantified based on degree of severity. RESULTS: Four unique papillary features were chosen for inclusion in the PPLA scoring system- ductal Plugging, Pitting, Loss of contour, and Amount of Randall's plaque. Unique scores are calculated for individual papillae based on reference examples. CONCLUSIONS: The description and study of renal papillary appearance in stone formers have considerable potential as both a clinical and research tool; however, a standardized grading system is necessary before using it for these purpos

    A prototype model for evaluating SKA-LOW station calibration

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    The Square Kilometre Array telescope at low-frequency (SKA-Low) will be a phased array telescope supporting a wide range of science cases covering the frequency band 50 - 350 MHz, while at the same time asking for high sensitivity and excellent characteristics. These extremely challenging requirements resulted in a design using 512 groups of 256 log periodic dual polarized antennas each (where each group is called ā€œstationā€), for a total of 131072 antennas. The 512 stations are randomly distributed mostly within a dense area around the centre of the SKA-Low, and then in 3 arms having 16 station clusters each. In preparation for the SKA Phase 1 (SKA1) System Critical Design Review (CDR), prototype stations were deployed at the Murchison Radio-astronomy Observatory (MRO) site (Western Australia) near the Murchison Widefield Array (MWA) radio telescope. The project involved multiple parties in an International collaboration building and testing different prototypes of the SKA1-Low station near the actual site. This resulted in both organisational and logistic challenges typical of a deployment of the actual telescope. The test set-up involved a phased build-up of the complex station of log-periodic antennas, by starting from the deployment of 48 antennas and related station signal processing (called AAVS1.5, where AAVS stands for Aperture Array Verification System), followed by expansion to a full station (AAVS2.0). As reference a station with dipole antennas EDA2 (EDA: Engineering Development Array) was deployed. This test set-up was used for an extensive test and evaluation programme. All test antenna configurations were simulated in detail by electromagnetic (EM) models, and the prediction of the models was further verified by appropriate tests with a drone-based radio frequency source. Astronomical observations on Sun and galaxy transit were performed with calibrated stations of both EDA2, AAVS1.5 and AAVS2.0. All 3 configurations were calibrated. EM modelling and calibration results for the full station AAVS2.0 and EM verification for the AAVS1.5 station are presented. The comparisons between the behaviour of the log-periodic antennas and the dipoles have advanced our understanding the calibration quality and the technological maturity of the future SKA1-Low array

    Nephrocalcinosis in Calcium Stone Formers Who Do Not Have Systemic Disease

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    Purpose Nephrocalcinosis is commonly present in primary hyperparathyroidism, distal renal tubular acidosis and medullary sponge kidney disease. To our knowledge it has not been studied in patients with calcium phosphate stones who do not have systemic disease. Materials and Methods We studied patients undergoing percutaneous nephrolithotomy who had calcium phosphate or calcium oxalate stones and did not have hyperparathyroidism, distal renal tubular acidosis or medullary sponge kidney disease. On postoperative day 1 all patients underwent noncontrast computerized tomography. If there were no residual calcifications, the patient was categorized as not having nephrocalcinosis. If there were residual calcifications, the patient underwent secondary percutaneous nephrolithotomy. If the calcifications were found to be stones, the patient was categorized as not having nephrocalcinosis. If the calcifications were not stones, the patient was categorized as having nephrocalcinosis. Patients were grouped based on the type of stones that formed, including hydroxyapatite, brushite and idiopathic calcium oxalate. The extent of nephrocalcinosis was quantified as 0ā€”absent nephrocalcinosis to 3ā€”extensive nephrocalcinosis. Patients with residual calcifications on postoperative day 1 noncontrast computerized tomography who did not undergo secondary percutaneous nephrolithotomy were excluded from analysis. The presence or absence of nephrocalcinosis was correlated with metabolic studies. Results A total of 67 patients were studied, including 14 with hydroxyapatite, 19 with brushite and 34 with idiopathic calcium oxalate calculi. Nephrocalcinosis was present in 10 of 14 (71.4%), 11 of 19 (57.9%) and 6 of 34 patients (17.6%) in the hydroxyapatite, brushite and idiopathic calcium oxalate groups, respectively (chi-square p = 0.01). The mean extent of nephrocalcinosis per group was 1.98, 1.32 and 0.18 for hydroxyapatite, brushite and idiopathic calcium oxalate, respectively (p ā‰¤0.001). The presence of nephrocalcinosis positively correlated with urine calcium excretion (mean Ā± SD 287.39 Ā± 112.49 vs 223.68 Ā± 100.67 mg per day, p = 0.03). Conclusions Patients without systemic disease who form hydroxyapatite and brushite stones commonly have coexistent nephrocalcinosis. Nephrocalcinosis can occur in calcium oxalate stone formers but the quantity and frequency of nephrocalcinosis in this group are dramatically less

    The UAV-based test source as an end-to-end verification tool for aperture arrays

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    A UAV-mounted radio-frequency transmitter is proposed as a known reference field source to perform a set of functional tests on aperture arrays. The experimental results obtained on complete prototypes (end-to-end) and sub-assemblies provide good confidence on both amplitude and timing verification

    222^{222}Rn contamination mechanisms on acrylic surfaces

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    In this work, the 222^{222}Rn contamination mechanisms on acrylic surfaces have been investigated. 222^{222}Rn can represent a significant background source for low-background experiments, and acrylic is a suitable material for detector design thanks to its purity and transparency. Four acrylic samples have been exposed to a 222^{222}Rn rich environment for different time periods, being contaminated by 222^{222}Rn and its progenies. Subsequently, the time evolution of radiocontaminants activity on the samples has been evaluated with Ī±\alpha and Ī³\gamma measurements, highlighting the role of different decay modes in the contamination process. A detailed analysis of the alpha spectra allowed to quantify the implantation depth of the contaminants. Moreover, a study of both Ī±\alpha and Ī³\gamma measurements pointed out the 222^{222}Rn diffusion inside the samples

    Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia

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