Χωρική Ανάλυση Περιστατικών Έρευνας-Διάσωσης (Search and Rescue-SAR) στον Ελλαδικό Χώρο με Χρήση Γεωγραφικών Συστημάτων Πληροφοριών

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Γεωπληροφορική

Hemolymphangioma of the lower extremities in children: two case reports

Abstract Background and purpose Hemo-lymphangiomas are rare benign tumors that arise from congenital malformation of the vascular system. They are usually diagnosed at birth or early in childhood. The management of hemo-lymphangiomas in children remains challenging because complete resection is often difficult to be achieved and recurrences are common. Methods We present the case of two children with a mass on their left tibia. Imaging modalities, plain radiograph, Ultrasonography and Magnetic Resonance were used to investigate the nature of the mass, the anatomical relationship to the neighboring tissues and help planning the surgical resection. The dominant diagnosis was hemo-lymphangioma. Both lesions increased in size in a short period of follow-up thus we decided to proceed to surgical excision. The diagnosis of hemo-lymphangioma was confirmed by histological examination of the surgical specimen. Post-operatively, seroma was formed to the first patient, managed by placing a drainage and immobilizing the limb on a splint. The second patient experienced no complications post-operatively. After 12 months of follow-up both patients had no complications or recurrence. Conclusions Very few cases of hemo-lymphangiomas of the extremities have been reported in the literature. Those tumors can grow slowly and remain asymptomatic for a long period of time or may become aggressive and enlarge rapidly, without invasive ability though. Radical resection is the choice of treatment offering the lowest recurrence rates. Other therapeutic methods are: aspiration and drainage, cryotherapy, injection of sclerotic agents and radiotherapy; although none of those offers better results that the surgical excision.</p

Ο ρόλος της αυτοανοσίας στις απορρίψεις νεφρικών μοσχευμάτων

Η επίδραση των αντισωμάτων έναντι του υποδοχέα τύπου 1 της αγγειοτενσίνης ΙΙ στην έκβαση της νεφρικής μεταμόσχευσης Εισαγωγή/Σκοπός: Μηχανισμοί αλλο- και αυτοανοσίας ενέχονται στην απόρριψη και στην απώλεια του νεφρικού μοσχεύματος. Σκοπός της μελέτης είναι η διερεύνηση της επίδρασης των αντισωμάτων έναντι του υποδοχέα τύπου 1 της αγγειοτενσίνης II (anti-AT1RAbs) τα οποία ανιχνεύονται ανεξάρτητα ή συγχρόνως με ειδικά στο δότη αντί-HLA αντισώματα (HLA-DSAs) στην έκβαση της νεφρικής μεταμόσχευσης. Υλικό &amp; Μέθοδος: Anti-AT1RAb και HLA-DSAs αναζητήθηκαν σε 71 λήπτες νεφρικού μοσχεύματος που εκδήλωσαν αποδεδειγμένη με βιοψία οξεία ή χρόνια απόρριψη, κυτταρική (TCMR) (n=51) ή μεσολαβούμενη από αντισώματα (ABMR) (n=20) οι οποίοι αποτέλεσαν την ομάδα απόρριψης (RG). Η ομάδα ελέγχου (CG) συμπεριέλαβε 71 ασθενείς με συγκρίσιμα χαρακτηριστικά χωρίς επεισόδιο απόρριψης. Η διάμεση περίοδος παρακολούθησης ήταν 3.7 (2.9-5.2) έτη. Τα αντισώματα μετρήθηκαν πριν και περιοδικά μετά τη μεταμόσχευση με μεθοδολογία Luminex (HLA-DSAs θετικά όταν MFI&gt;1000) και ανοσοενζυμική μέθοδο (anti-AT1RAbs θετικά όταν τίτλος ≥10U/mL). Αποτελέσματα: Πριν τη μεταμόσχευση, 23 (32.4%) ασθενείς στο RG, 16 με TCMR και 7 με ABMR, βρέθηκαν θετικοί στα anti-AT1RAbs έναντι 11 (15.5%) ασθενών στο CG (p=0.031). προσχηματισμένα HLA-DSAs ανιχνεύθηκαν σε 19 (26.7%) ασθενείς στο RG έναντι 6 (8.4%) στο CG (p=0.010). Ταυτόχρονη ανίχνευση anti-AT1RAbs και HLA-DSAs πριν τη μεταμόσχευση διαπιστώθηκε σε 5 patients στο RG έναντι 2 στο CG (p=0.355). Τη χρονική στιγμή της βιοψίας, 15 (21.1%) ασθενείς, 4 με ABMR και 11 με TCMR, ήταν θετικοί στα anti-AT1RAbs. Anti-AT1RAbs και HLA-DSAs ανιχνεύτηκαν ταυτόχρονα σε 7/15 (46.7%) περιπτώσεις, 3 με ABMR and 4 με TCMR. Στη διάρκεια της παρακολούθησης, 13 (18.3%) ασθενείς στο RG, 8 με ABMR και 5 με TCMR, έχασαν το μόσχευμα έναντι 1 ασθενούς (1.4%) στο CG (p=0.001). Έξι από τους 13 (46.2%) ασθενείς στο RG που έχασαν το μόσχευμα βρέθηκαν θετικοί στα anti-AT1RAbs πριν τη μεταμόσχευση. Η επιβίωση ασθενών με λειτουργούν μόσχευμα δεν διέφερε σημαντικά μεταξύ anti-AT1RAbs θετικών and -αρνητικών ληπτών νεφρικού μοσχεύματος (log-rank p=0.88). Η ταυτόχρονη ανίχνευση anti-ATR1Abs και HLA-DSAs δεν είχε σημαντική επίδραση στην επιβίωση ασθενών με λειτουργούν μόσχευμα (log-rank p=0.96). Η λειτουργία του νεφρικού μοσχεύματος στο τέλος της περιόδου παρακολούθησης ήταν καλύτερη, αλλά όχι σημαντικά, σε anti-AT1RAbs-αρνητικούς ασθενείς, με κρεατινίνη ορού 1.48 [1.20-1.98] mg/dL και eGFR (CKD-EPI) 48.5 [33.5-59.0] ml/min/1.73m2, έναντι των anti-AT1RAbs-θετικών που είχαν κρεατινίνη ορού 1.65 [1.24-2.02] mg/dL (p=0.394) και eGFR (CKD-EPI) 47.0 [34.8-60.3] ml/min/1.73m2 (p=0.966). Συμπεράσματα: Η ανίχνευση anti-ATR1Abs πριν τη μεταμόσχευση χαρακτηρίζει λήπτες νεφρικού μοσχεύματος με αυξημένο κίνδυνο απόρριψης, κυτταρικής ή μεσολαβούμενης από αντισώματα. Επιπλέον, τα anti-AT1RAbs, που ανιχνεύονται μόνα τους ή ταυτόχρονα με HLA-DSAs, φαίνεται να σχετίζονται με μειωμένη λειτουργία μοσχεύματος, αλλά ο ρόλος τους στην επιβίωση του μοσχεύματος δεν μπορεί να τεκμηριωθεί στην παρούσα μελέτη. Ο έλεγχος για αυτά τα αντισώματα φαίνεται να συμβάλλει στην εκτίμηση του ανοσολογικού κινδύνου πριν τη νεφρική μεταμόσχευση.The influence of antibodies against angiotensin II type-1 receptor on the outcome of kidney transplantation: a single-center retrospective study Background: Allo- and autoimmune mechanisms are involved in kidney allograft rejection and loss. This study investigates the impact of anti-angiotensin II type-1 receptor antibodies (anti-AT1RAbs) detected alone or in association with HLA donor specific antibodies (HLA-DSAs) on the outcome of kidney transplantation (KTx). Patients and Methods: Anti-AT1RAbs and HLA-DSAs were detected in 71 kidney transplant (KT) recipients who developed biopsy-proven acute or chronic active T-cell rejection (TCMR) (n = 51) or antibody-mediated rejection (ABMR) (n = 20), forming the rejection group (RG). The control group (CG) included 71 KTx recipients with comparable characteristics without rejection. All patients had been transplanted with negative T/B flow crossmatch (T/BFCXM). The median follow- up period was 3.7 (2.9- 5.2) years. Antibodies were determined pre- and periodically post-KTx by Luminex method for HLA-DSAs and enzyme-linked immunosorbent assay for anti-AT1RAbs. Results: Before KTx, 23 (32.4%) patients in the RG, 16 with TCMR and 7 with ABMR, were found anti-AT1RAbs positive versus 11 (15.5%) patients in the CG (p=0.031). Preformed HLA-DSAs, not detected with T/BFCXM, were found in 19 (26.7%) patients in the RG as compared to 6 (8.4%) in the CG (p=0.010). Simultaneous detection of preformed antiAT1RAbs and HLA-DSAs was found in 5 patients of RG versus 2 of CG (p=0.355). At the time of transplant biopsy, 15 (21.1%) patients, 4 with ABMR and 11 with TCMR, were positive for anti-AT1RAbs. Anti-AT1RAbs and HLA-DSAs were detected simultaneously in 7/15 (46.7%) cases, 3 with ABMR and 4 with TCMR. During the follow-up, 13 (18.3%) patients in the RG, 8 with ABMR and 5 with TCMR, lost their graft as compared to 1 patient (1.4%) in the CG (p=0.001). Six out of 13 (46.2%) RG patients who lost the graft, were found positive for anti-AT1RAbs pretransplant. Patient survival with functioning graft did not differ significantly between anti-AT1RAbs-positive and -negative KT recipients (log-rank p=0.88). Simultaneous detection of anti-ATR1Abs and HLADSAs did not have a significant influence on patient survival with functioning graft (log-rank p=0.96). Graft function at the end of follow-up was better, but not significantly, in anti-AT1RAbs-negative patients, with serum creatinine 1.48 [1.20-1.98] mg/dL and eGFR (CKD-EPI) 48.5 [33.5- 59.0] ml/min/1.73m2, as compared to anti-AT1RAbs-positive ones who had serum creatinine 1.65 [1.24-2.02] mg/dL (p=0.394) and eGFR (CKD-EPI) 47.0 [34.8-60.3] ml/min/1.73m2 (p=0.966). Conclusions: Αnti-AT1RAbs detection pretransplant characterizes KT recipients at increased risk of cellular or antibody-mediated rejection. Furthermore, anti-AT1RAbs, detected alone or simultaneously with HLA-DSAs, appear to be associated with impaired graft function, but their role in graft survival has not been documented in this study. Screening for these antibodies appears to complement pretransplant immunological risk assessment

The influence of the frequency of pulsating jets on the recirculation zone of a backward facing step. An experimental study

168 σ.Στην παρούσα εργασία διερευνήθηκε πειραματικά η επίδραση της συχνότητας παλλόμενων δεσμών αέρα στον έλεγχο της ροής απότομης διεύρυνσης. Ο αριθμός Reynolds της ροής ήταν Re = 8000, ενώ οι παλλόμενες δέσμες αέρα εισήχθησαν στη ροή από μια σχισμή, η οποία περιείχε 20 οπές, πολύ κοντά στην άνω ακμή της απότομης διεύρυνσης. Για τις μετρήσεις χρησιμοποιήθηκε η τεχνική PIV δύο διαστάσεων (2D-Particle Image Velocimetry) με σύστημα σκανδαλισμού. Τα αποτελέσματα έδειξαν ότι στη ροή σχηματίζονται δύο περιοχές ανακυκλοφορίας, μια κύρια ανθωρολογιακής φοράς (port όπως την αντιλαμβάνεται ένας παρατηρητής που κινείται μαζί με το ελεύ- θερο ρεύμα), η οποία εκτείνεται από την περιοχή απότομης διεύρυνσης μέχρι την περιοχή επανακόλλησης και μια δευτερεύουσα, η οποία είναι ωρολογιακής φοράς, βρίσκεται στην περιοχή της κάτω ακμής της απότομης διεύρυνσης και είναι πολύ μικρότερη της πρώτης. Το μήκος επανακόλλησης μεταβάλλεται με τη συχνότητα των δεσμών, ενώ υπάρχει μια συχνότητα στην οποία το μήκος γίνεται ελάχιστο. Όταν η ροή διεγείρεται με τη βέλτι- στη συχνότητα, ώστε να ισχύει St = 0.22 για τον αδιάστατο αριθμό Strouhal με βάση το ύψος H της απότομης διεύρυνσης, το μήκος επανακόλλησης μειώνεται κατά 21% περίπου σε σχέση με το μήκος χωρίς έλεγχο. Με την διεξαγωγή συγχρονισμένων μετρήσεων μέσα στην περίοδο της δέσμης, παρατηρήθηκε ότι το μήκος επανακόλλη- σης μεταβάλλεται κατά τη διάρκεια μιας περιόδου και η όλη διαδικασία είναι ένα ασταθές δυναμικό φαινόμενο. Συγχρονισμένες μετρήσεις κοντά στην απότομη διεύρυνση έδειξαν την ύπαρξη μιας δίνης, η οποία εκλύεται από το ύψος της άνω ακμής της απότομης διεύρυνσης και ταξιδεύει επεκτεινόμενη μέσα στην περίοδο προς το σημείο επανακόλλησης. Η ταχύτητά της Ux βρέθηκε περίπου σταθερή και ίση με 0.33U∞ και η Uy = 0.09U∞.In the present Diploma Thesis the effect of the frequency of pulsating jets on the recirculation zone of a backward facing step was experimentally investigated. A Re = 8000 was chosen as test case and periodic perturbation was introduced from a slot, containing 20 holes, near the step edge. A two dimensional particle image velocimeter (PIV) with a triggering mechanism was used in the flow-field measurements. The measurements showed that there are two recirculation bubbles in the flow, one major counter-clockwise bubble (port as received by a person travelling with the free stream), which expands from the step area to the recirculation region and a minor port clockwise bubble, which is formed near the bottom area of the step and is considerably smaller than the first one. The reattachment length varies with the perturbation frequency, while there exists an optimum frequency, in which the reattachment length is minimum. When perturbed with this optimum frequency, with which the nondimensional Strouhal number based on the step height H is St = 0.22, the reattachment length is reduced by almost 21% of the uncontrolled case. Performing synchronised measurements inside the jet period, it was observed that the reattachment length varies also in the period itself. The reattachment process is therefore a highly non-stable dynamic phenomenon. Synchronised measurements near the the backward facing step showed that there exists a vortex, which is released from the step edge and travels towards the reattachment region, expanding inside the period. This vortex is travelling with an almost stable velocity component, Ux = 0.33U∞ and a velocity component Uy = 0.09U∞.Γεώργιος Κ. Φιλιόπουλο

Genomic Damage in Endstage Renal Disease—Contribution of Uremic Toxins

Patients with end-stage renal disease (ESRD), whether on conservative, peritoneal or hemodialysis therapy, have elevated genomic damage in peripheral blood lymphocytes and an increased cancer incidence, especially of the kidney. The damage is possibly due to accumulation of uremic toxins like advanced glycation endproducts or homocysteine. However, other endogenous substances with genotoxic properties, which are increased in ESRD, could be involved, such as the blood pressure regulating hormones angiotensin II and aldosterone or the inflammatory cytokine TNF-α. This review provides an overview of genomic damage observed in ESRD patients, focuses on possible underlying causes and shows modulations of the damage by modern dialysis strategies and vitamin supplementation

Test performance of faecal occult blood testing for the detection of bowel cancer in people with chronic kidney disease (DETECT) protocol

<p>Abstract</p> <p>Background</p> <p>Cancer is a major cause of mortality and morbidity in patients with chronic kidney disease (CKD). In patients without kidney disease, screening is a major strategy for reducing the risk of cancer and improving the health outcomes for those who developed cancers by detecting treatable cancers at an early stage. Among those with CKD, the effectiveness, the efficacy and patients' preferences for cancer screening are unknown.</p> <p>Methods/Design</p> <p>This work describes the protocol for the DETECT study examining the effectiveness, efficiency and patient's perspectives of colorectal cancer screening using immunochemical faecal occult blood testing (iFOBT) for people with CKD. The aims of the DETECT study are 1) to determine the test performance characteristics of iFOBT screening in individuals with CKD, 2) to estimate the incremental costs and health benefits of iFOBT screening in CKD compared to no screening and 3) to elicit patients' perspective for colorectal cancer screening in the CKD population. Three different study designs will be used to explore the uncertainties surrounding colorectal cancer screening in CKD. A diagnostic test accuracy study of iFOBT screening will be conducted across all stages of CKD in patients ages 35-70. Using individually collected direct healthcare costs and outcomes from the diagnostic test accuracy study, cost-utility and cost-effective analyses will be performed to estimate the costs and health benefits of iFOBT screening in CKD. Qualitative in-depth interviews will be undertaken in a subset of participants from the diagnostic test accuracy study to investigate the perspectives, experiences, attitudes and beliefs about colorectal cancer screening among individuals with CKD.</p> <p>Discussion</p> <p>The DETECT study will target the three major unknowns about early cancer detection in CKD. Findings from our study will provide accurate and definitive estimates of screening efficacy and efficiency for colorectal cancer, and will allow better service planning and budgeting for early cancer detection in this at-risk population.</p> <p>The DETECT study is also registered with the Australia New Zealand Clinical Trials Registry <a href="http://www.anzctr.org.au/ACTRN12611000538943.aspx">ACTRN12611000538943</a></p

Uremic myopathy: Is oxidative stress implicated in muscle dysfunction in uremia?

© 2015 The Authors. Published by Frontiers Media. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3389/fphys.2015.00102Renal failure is accompanied by progressive muscle weakness and premature fatigue, in part linked to hypokinesis and in part to uremic toxicity. These changes are associated with various detrimental biochemical and morphological alterations. All of these pathological parameters are collectively termed uremic myopathy. Various interventions while helpful can't fully remedy the pathological phenotype. Complex mechanisms that stimulate muscle dysfunction in uremia have been proposed, and oxidative stress could be implicated. Skeletal muscles continuously produce reactive oxygen species (ROS) and reactive nitrogen species (RNS) at rest and more so during contraction. The aim of this mini review is to provide an update on recent advances in our understanding of how ROS and RNS generation might contribute to muscle dysfunction in uremia. Thus, a systematic review was conducted searching PubMed and Scopus by using the Cochrane and PRISMA guidelines. While few studies met our criteria their findings are discussed making reference to other available literature data. Oxidative stress can direct muscle cells into a catabolic state and chronic exposure to it leads to wasting. Moreover, redox disturbances can significantly affect force production per se. We conclude that oxidative stress can be in part responsible for some aspects of uremic myopathy. Further research is needed to discern clear mechanisms and to help efforts to counteract muscle weakness and exercise intolerance in uremic patients.This work has been co-financed by the European Union (European Social Fund—ESF) and Greek national funds through the Operational Program “Educational and Lifelong Learning” of the National Strategic Reference Framework (NSRF)—Research Funding Program: Thales (MuscleFun Project-MIS 377260) Investing in knowledge society through the European Social Fund.Published versio