12 research outputs found

    Toward an Expert System for Terrain Analysis.

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    Terrain analysis is the systematic study of image patterns relating to the origin, and composition of distinct terrain units called landforms. It takes into account and provides information about physical site factors which are used by civil engineers for evaluating the suitability of a site for a terrain related engineering application. Terrain analysis is a time consuming labor intensive process and requires a significant degree of expertise. In this dissertation, an expert system paradigm has been adopted, for developing a computational approach to terrain analysis problem solving. A methodology was developed for the representation and management of uncertain terrain knowledge. The vagueness that is inherent in the descriptions of terrain analysis terms was represented using fuzzy models. The Dempster-Shafer theory of evidence was adopted to establish hypotheses about the type of terrain based on observed evidences. A goal directed backward form of reasoning was employed for evaluating the suitability of a site for a terrain related engineering application. The reasoning strategy was formalized in production rules, and the fuzzy models of terrain terms were formalized in frames. Procedural computations were formalized in LISP code. The methodology was implemented in the Terrain Analysis eXpert (TAX) system. TAX was developed by employing the expert system shell KEE (Knowledge Engineering Environment) and the image processing package ELAS (Earth resources Laboratory Application Software). TAX was tested with a real data set consisting of a digitized color infra-red photograph and digital elevation data. The conclusions arrived at by TAX compared favorably to those reached by an expert who analyzed the same site using traditional photointerpretation techniques

    Effect of sildenafil in liver ischemia/reperfusion

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    We evaluated the role of sildenafil in a rat liver ischemia-reperfusion model. Forty male rats were randomly allocated in four groups. The sham group underwent midline laparotomy only. In the sildenafil group, sildenafil was administered intraperitoneally 60 minutes before sham laparotomy. In the ischemia-reperfusion (I/R) group, rats were subjected to 45 minutes of hepatic ischemia followed by 120 minutes of reperfusion, while in the sild+I/R group rats were subjected to a similar pattern of I/R after the administration of sildenafil, 60 minutes before ischemia. Two hours after reperfusion, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured and histopathological examination of the lobes subjected to ischemia as well as TUNEL staining for apoptotic bodies was performed. Additionally, myeloperoxidase (MPO) activity and the expression of intercellular adhesion molecule-1 (ICAM-1) were analyzed. Serum markers of hepatocellular injury were significantly lower in the sild+I/R group, which also exhibited lower severity of histopathological lesions and fewer apoptotic bodies, as compared to the I/R group. The I/R group showed significantly higher MPO activity and higher expression of ICAM-1, as compared to the sild+I/R group. Use of sildenafil as a preconditioning agent in a rat model of liver I/R exerted a protective effect.Αξιολογήσαμε την επίδραση της σιλδεναφίλης σε ένα πρότυπο ισχαιμίας-επαναιμάτωσης ήπατος σε επίμυες. Σαράντα αρσενικοί επίμυες χωρίστηκαν τυχαία σε τέσσερις ομάδες. Η ομάδα sham υποβλήθηκε μόνο σε μέση λαπαροτομία. Στην ομάδα της σιλδεναφίλης (sild+sham), χορηγήθηκε σιλδεναφίλη ενδοπεριτοναϊκά και ακολούθησε μετά από 60 λεπτά μέση λαπαροτομία. Στην ομάδα ισχαιμίας-επαναιμάτωσης (I/R), οι επίμυες υποβλήθηκαν σε 45 λεπτά ηπατικής ισχαιμίας η οποία ακολουθήθηκε από 120 λεπτά επαναιμάτωσης, ενώ στην ομάδα της σιλδεναφίλης και ισχαιμίας-επαναιμάτωσης (Sild+I/R) οι επίμυες υποβλήθηκαν σε παρόμοια διαδικασία με την ομάδα Ι/R αφού προηγήθηκε χορήγηση σιλδεναφίλης 60 λεπτά πριν από την πρόκληση ισχαιμίας. Δύο ώρες μετά την επαναιμάτωση, μετρήθηκαν τα επίπεδα της αμινοτρανσφεράσης της αλανίνης (ALT) και της ασπαρτικής αμινοτρανσφεράσης (AST) ορού και πραγματοποιήθηκε ιστοπαθολογική εξέταση των λοβών που είχαν υποβληθεί σε ισχαιμία. Πραγματοποιήθηκε χρώση TUNEL για την ανίχνευση αποπτωτικών σωμάτων και επιπρόσθετα αναλύθηκε η δραστικότητα της μυελοϋπεροξειδάσης (ΜΡΟ) και η έκφραση του μορίου διακυτταρικής προσκόλλησης-1 (ICAM-1). Οι δείκτες ηπατοκυτταρικής βλάβης του ορού ήταν σημαντικά χαμηλότεροι στην ομάδα Sild+I/R, η οποία παρουσίασε επίσης μειωμένης βαρύτητας ιστοπαθολογικές αλλοιώσεις και λιγότερα αποπτωτικά σώματα, σε σύγκριση με την ομάδα Ι/R. Η ομάδα Ι/R έδειξε σημαντικά υψηλότερη δραστικότητα ΜΡΟ και υψηλότερη έκφραση του ICAM-1, σε σύγκριση με την ομάδα Sild+I/R. H xρήση της σιλδεναφίλης ως μέσο ισχαιμικής προετοιμασίας, στο συγκεκριμένο πρότυπο ισχαιμίας-επαναιμάτωσης ήπατος σε επίμυες, έδειξε να ασκεί προστατευτική δράση

    Sympathetic Nerve Injury in Thyroid Cancer

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    The double innervation of the thyroid comes from the sympathetic and parasympathetic nervous system. Injury rates during surgery are at 30% but can be minimized by upwardly preparing the thyroid vessels at the level of thyroid capsule. Several factors have been accused of increasing the risk of injury including age and tumor size. Our aim was to investigate of there is indeed any possible correlations between these factors and a possible increase in injury rates following thyroidectomy. Seven studies were included in the meta-analysis. Statistical correlation was observed for a positive relationship between injury of the sympathetic nerve and thyroid malignancy surgery (p < 0.001; I2 = 74%) No statistical correlations were observed for a negative or positive relationship between injury of the sympathetic nerve and tumor size. There was also no statistically significant value observed for the correlation of the patients’ age with the risk of sympathetic nerve injury (p = 0.388). Lack of significant correlation reported could be due to the small number of studies and great heterogeneity between them

    Spinal ependymomas: Prognostic factors and treatment results

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    Objective: We retrospectively analyzed patients with spinal ependymomas who were treated in our institute. We correlated outcome and recurrence with clinical and pathological features. Materials and Methods: Between January 2000 and January 2010, we treated 14 patients with spinal ependymoma (10 males, 4 females; mean age: 48.3±18 years, range: 18-79 years). All patients were operated and received standard postoperative care. The outcome was estimated based on Frankel scale. Results: The most common presenting symptom was pain. All tumors were operated through a posterior approach and gross total resection was performed in 13/14 cases. Histopathological examination revealed the presence of one anaplastic ependymoma, nine grade II ependymomas, and four myxopapillary ependymomas. The mean Ki-67 index was 1.5%. All the patients were followed up postoperatively for an average of 5.1 years. One patient was reoperated because of recurrent disease and another received radiotherapy due to dissemination of disease. No association was found between extent of resection, tumor location, Ki-67 index, and recurrence of disease. There was a trend toward a higher risk of recurrence in myxopapillary ependymomas. Eight patients improved postoperatively. Interestingly, during the follow-up period, four patients developed a secondary neoplasia. Conclusion: Early intervention and gross total resection of spinal ependymomas are associated with a favorable outcome. Further studies are needed to clarify the incidence of the development of a second cancer in these patients

    Government Debt Crisis and the Impact on National Health Systems: A Retrospective Study and Policy Recommendations to Greece

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    This article aims to explore the impact of the government debt crisis on the national health system (NHS) using a representative sample of respondents in Greek hospitals and provides certain suggestions regarding health policies that could be implemented at the national or local level. This study was conducted at the Evangelismos &amp; Eye Polyclinic of Athens General Hospital in Athens, Greece. The study period was January and February of 2016, and the study included 600 outpatients who frequently submitted to follow-ups and consented to participate. Based on the results of this study, the participants had an average health status, while 94.2% of them had medical insurance. The predominant reason (88%) for choosing public hospitals instead of private practices was insufficient income. Further investigation revealed a significant positive correlation between the participant’s age and the number of hospital visits, the number of medical tests performed, and their satisfaction from the health services provided. Finally, a probit-model was used in order to study factors that could potentially influence their level of satisfaction from the services they used

    The Role of SNHG15 in the Pathogenesis of Hepatocellular Carcinoma

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    Long non-coding RNAs (lncRNAs) are transcripts of more than 200 nucleotides which cannot be translated into proteins. Small nucleolar RNA host gene 15 (SNHG15) is a lncRNA whose dysregulation has been found to have an important impact on carcinogenesis and affect the prognosis of cancer patients in various cancer types. Hepatocellular carcinoma (HCC) is one of the most common cancers with a poor long-term prognosis, while the best prognostic factor of the disease is its early diagnosis and surgery. Consequently, the investigation of the mechanisms of hepatocarcinogenesis, as well as the discovery of efficient molecular markers and therapeutic targets are of great significance. An extensive literature search was performed in MEDLINE in order to identify clinical studies that tried to reveal the role of SNHG15 in HCC. We used keywords such as &lsquo;HCC&rsquo;, &lsquo;hepatocellular carcinoma&rsquo;, &lsquo;SNHG15&rsquo; and &lsquo;clinical study&rsquo;. Finally, we included four studies written in English, published during the period 2016&ndash;2021. It was revealed that SNHG15 is related to the appearance of HCC via different routes and its over-expression affects the overall survival of the patients. More assays are required in order to clarify the potential role of SNHG15 as a prognostic tool and therapeutic target in HCC

    Intensive-Dose Tinzaparin in Hospitalized COVID-19 Patients: The INTERACT Study

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    (1) Background: It is well-established that coronavirus disease-2019 (COVID-19) is highly pro-inflammatory, leading to activation of the coagulation cascade. COVID-19-induced hypercoagulability is associated with adverse outcomes and mortality. Current guidelines recommend that hospitalized COVID-19 patients should receive pharmacological prophylaxis against venous thromboembolism (VTE). (2) INTERACT is a retrospective, phase IV, observational cohort study aiming to evaluate the overall clinical effectiveness and safety of a higher than conventionally used prophylactic dose of anticoagulation with tinzaparin administered for VTE prevention in non-critically ill COVID-19 patients with moderate disease severity. (3) Results: A total of 705 patients from 13 hospitals in Greece participated in the study (55% men, median age 62 years). Anticoagulation with tinzaparin was initiated immediately after admission. A full therapeutic dose was received by 36.3% of the participants (mean ± SD 166 ± 33 IU/Kgr/day) and the remaining patients (63.9%) received an intermediate dose (mean ± SD 114 ± 22 IU/Kgr/day). The median treatment duration was 13 days (Q1–Q3: 8–20 days). During the study (April 2020 to November 2021), 14 thrombotic events (2.0%) were diagnosed (i.e., three cases of pulmonary embolism (PE) and 11 cases of deep venous thrombosis, DVT). Four bleeding events were recorded (0.6%). In-hospital death occurred in 12 patients (1.7%). Thrombosis was associated with increasing age (median: 74.5 years, Q1–Q3: 62–79, for patients with thrombosis vs. 61.9 years, Q1–Q3: 49–72, p = 0.0149), increased D-dimer levels for all three evaluation time points (at admission: 2490, Q1–Q3: 1580–6480 vs. 700, Q1–Q3: 400–1475, p p p < 0.0001). Clinical and laboratory improvement was affirmed by decreasing D-dimer and CRP levels, increasing platelet numbers and oxygen saturation measurements, and a drop in the World Health Organization (WHO) progression scale. (4) Conclusions: The findings of our study are in favor of prophylactic anticoagulation with an intermediate to full therapeutic dose of tinzaparin among non-critically ill patients hospitalized with COVID-19

    Early treatment of COVID-19 with anakinra guided by soluble urokinase plasminogen receptor plasma levels: a double-blind, randomized controlled phase 3 trial

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    Early increase of soluble urokinase plasminogen activator receptor (suPAR) serum levels is indicative of increased risk of progression of coronavirus disease 2019 (COVID-19) to respiratory failure. The SAVE-MORE double-blind, randomized controlled trial evaluated the efficacy and safety of anakinra, an IL-1 alpha/beta inhibitor, in 594 patients with COVID-19 at risk of progressing to respiratory failure as identified by plasma suPAR &gt;= 6 ng ml(-1), 85.9% (n = 510) of whom were receiving dexamethasone. At day 28, the adjusted proportional odds of having a worse clinical status (assessed by the 11-point World Health Organization Clinical Progression Scale (WHO-CPS)) with anakinra, as compared to placebo, was 0.36 (95% confidence interval 0.26-0.50). The median WHO-CPS decrease on day 28 from baseline in the placebo and anakinra groups was 3 and 4 points, respectively (odds ratio (OR) = 0.40, P &lt; 0.0001); the respective median decrease of Sequential Organ Failure Assessment (SOFA) score on day 7 from baseline was 0 and 1 points (OR = 0.63, P = 0.004). Twenty-eight-day mortality decreased (hazard ratio = 0.45, P = 0.045), and hospital stay was shorter.The SAVE-MORE phase 3 study demonstrates the efficacy of anakinra, an IL-1 alpha/beta inhibitor, in patients with COVID-19 and high serum levels of soluble plasminogen activator receptor
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