20,991 research outputs found

    Evaluation and treatment decision of pancreatic tumors by use of MRI with MRCP imaging

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    Background: Pancreatic cancer is one of the most malignant tumors. Symptoms are usually nonspecific and insidious such that the cancer is advanced by the time of diagnosis. The aim of our work was to investigate the use of MRI and MRCP in diagnosis of the patients suspected of pancreatic carcinoma and to determine the role of these methods in the evaluation of resectability of pancreatic cancer in comparison to surgical findings. Material/Methods: Forty-nine patients (33 men and 16 women) aged 44-82 had undergone to MRI and MRCP imagination of the upper abdomen on 1.5 T system with use of a standard flexible surface coil. The results of those radiological diagnostic tests were compare to the surgical findings and histopathological examination. The capacity of MR and MRCP to detect pathological mass, assess disease process nature and accuracy of assessment of the resectability of the malignant lesion were evaluated. In the statistical analysis test X2 and Fisher's precise test were performed. Results: A statistical analysis determined 88% sensitivity, 95% specifity and 94% exactness of MRI and MRCP in the evaluation of nature of tumors within the pancreas and 100% sensitivity, 91% specificity and 95% accuracy in determining the resectability of the lesion. The positive predictive value came to 83%, while the negative predictive value to 100%. The Kappa compatibility index in comparison with a surgical findings came to 0.85714. Conclusions: MR and MRCP appears an important stage in diagnosis and in assessment of pancreatic tumors. By the estimation of tumor respectability it aids clinical management

    Continuous volumetric imaging via an optical phase-locked ultrasound lens

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    In vivo imaging at high spatiotemporal resolution is key to the understanding of complex biological systems. We integrated an optical phase-locked ultrasound lens into a two-photon fluorescence microscope and achieved microsecond-scale axial scanning, thus enabling volumetric imaging at tens of hertz. We applied this system to multicolor volumetric imaging of processes sensitive to motion artifacts, including calcium dynamics in behaving mouse brain and transient morphology changes and trafficking of immune cells

    Pvr expression regulators in equilibrium signal control and maintenance of Drosophila blood progenitors.

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    Blood progenitors within the lymph gland, a larval organ that supports hematopoiesis in Drosophila melanogaster, are maintained by integrating signals emanating from niche-like cells and those from differentiating blood cells. We term the signal from differentiating cells the 'equilibrium signal' in order to distinguish it from the 'niche signal'. Earlier we showed that equilibrium signaling utilizes Pvr (the Drosophila PDGF/VEGF receptor), STAT92E, and adenosine deaminase-related growth factor A (ADGF-A) (Mondal et al., 2011). Little is known about how this signal initiates during hematopoietic development. To identify new genes involved in lymph gland blood progenitor maintenance, particularly those involved in equilibrium signaling, we performed a genetic screen that identified bip1 (bric à brac interacting protein 1) and Nucleoporin 98 (Nup98) as additional regulators of the equilibrium signal. We show that the products of these genes along with the Bip1-interacting protein RpS8 (Ribosomal protein S8) are required for the proper expression of Pvr

    Spatio-temporal Models of Lymphangiogenesis in Wound Healing

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    Several studies suggest that one possible cause of impaired wound healing is failed or insufficient lymphangiogenesis, that is the formation of new lymphatic capillaries. Although many mathematical models have been developed to describe the formation of blood capillaries (angiogenesis), very few have been proposed for the regeneration of the lymphatic network. Lymphangiogenesis is a markedly different process from angiogenesis, occurring at different times and in response to different chemical stimuli. Two main hypotheses have been proposed: 1) lymphatic capillaries sprout from existing interrupted ones at the edge of the wound in analogy to the blood angiogenesis case; 2) lymphatic endothelial cells first pool in the wound region following the lymph flow and then, once sufficiently populated, start to form a network. Here we present two PDE models describing lymphangiogenesis according to these two different hypotheses. Further, we include the effect of advection due to interstitial flow and lymph flow coming from open capillaries. The variables represent different cell densities and growth factor concentrations, and where possible the parameters are estimated from biological data. The models are then solved numerically and the results are compared with the available biological literature.Comment: 29 pages, 9 Figures, 6 Tables (39 figure files in total

    The intestinal lymphatic system: Functions and metabolic implications

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    The lymphatic system of the gut plays important roles in the transport of dietary lipids, as well as in immunosurveillance and removal of interstitial fluid. Historically, despite its crucial functions in intestinal homeostasis, the lymphatic system has been poorly studied. In the last 2 decades, identification of specific molecular mediators of lymphatic endothelial cells (LECs) growth together with novel genetic approaches and intravital imaging techniques, have advanced our understanding of the mechanisms regulating intestinal lymphatic physiology in health and disease. As its metabolic implications are gaining recognition, intestinal lymphatic biology is currently experiencing a surge in interest. This review describes current knowledge related to molecular control of intestinal lymphatic vessel structure and function. We discuss regulation of chylomicron entry into lymphatic vessels by vascular endothelial growth factors (VEGFs), hormones, transcription factors and the specific signaling pathways involved. The information covered supports the emerging role of intestinal lymphatics in etiology of the metabolic syndrome and their potential as a therapeutic target. Keywords: Lacteals, Lipid, VEGF Signaling, Endothelium, Obesit

    Dye diffusion during laparoscopic tubal patency tests may suggest a lymphatic contribution to dissemination in endometriosis: A prospective, observational study

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    Aim Women with adenomyosis are at higher risk of endometriosis recurrence after surgery. This study was to assess if the lymphatic vessel network drained from the uterus to near organs where endometriosis foci lied. Methods A prospective, observational study, Canadian Task Force Classification II-2, was conducted at Sacro Cuore Don Calabria Hospital, Negrar, Italy. 104 white women aged 18–43 years were enrolled consecutively for this study. All patients underwent laparoscopy for endometriosis and a tubal dye test was carried out. Results Evidence of dye dissemination through the uterine wall and outside the uterus was noted in 27 patients (26%) with adenomyosis as it permeated the uterine wall and a clear passage of the dye was shown in the pelvic lymphatic vessels regardless whether the tubes were unobstructed. Histological assessment of the uterine biopsies confirmed adenomyosis. Conclusion Adenomyosis is characterized by ectatic lymphatics that allow the drainage of intrauterine fluids (the dye and, perhaps, menstrual blood) at minimal intrauterine pressure from the uterine cavity though the lymphatic network to extrauterine organs. Certainly, this may not be the only explanation for endometriosis dissemination but the correlation between the routes of the dye drainage and location of endometriosis foci is highly suggestive
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