A Knowledge-Based Deep Learning Architecture for Aspect-Based Sentiment Analysis.

The task of sentiment analysis tries to predict the affective state of a document by examining its content and metadata through the application of machine learning techniques. Recent advances in the field consider sentiment to be a multi-dimensional quantity that pertains to different interpretations (or aspects), rather than a single one. Based on earlier research, the current work examines the said task in the framework of a larger architecture that crawls documents from various online sources. Subsequently, the collected data are pre-processed, in order to extract useful features that assist the machine learning algorithms in the sentiment analysis task. More specifically, the words that comprise each text are mapped to a neural embedding space and are provided to a hybrid, bi-directional long short-term memory network, coupled with convolutional layers and an attention mechanism that outputs the final textual features. Additionally, a number of document metadata are extracted, including the number of a document's repetitions in the collected corpus (i.e. number of reposts/retweets), the frequency and type of emoji ideograms and the presence of keywords, either extracted automatically or assigned manually, in the form of hashtags. The novelty of the proposed approach lies in the semantic annotation of the retrieved keywords, since an ontology-based knowledge management system is queried, with the purpose of retrieving the classes the aforementioned keywords belong to. Finally, all features are provided to a fully connected, multi-layered, feed-forward artificial neural network that performs the analysis task. The overall architecture is compared, on a manually collected corpus of documents, with two other state-of-the-art approaches, achieving optimal results in identifying negative sentiment, which is of particular interest to certain parties (like for example, companies) that are interested in measuring their online reputation.

Influenza vaccination among nurses in Greece.

Seasonal influenza has become a serious public health problem worldwide, and vaccination is recognized as the most effective preventative measure. However, data suggest that influenza vaccination rates are generally low among health care workers. The present study showed that the vaccination rates for influenza among nurses are 21.2%.

Hypoparathyroidism and heart failure in thalassemic patients: a case report.

Hypocalcemic cardiomyopathy due to primary or secondary hypoparathyroidism is usually refractory to conventional treatment for cardiac failure but responds favorably to the restoration of normocalcemia. We report on a thalassemic patient with severe cardiac failure due to hypocalcemia. Cardiac echocardiography showed impaired biventricular performance and laboratory analyses revealed hypoparathyroidism due to hemosiderosis. Concomitant treatment for heart failure and calcium supplementation was initiated. Thereafter, clinical and laboratory improvement was achieved. In the literature of thalassemic disorders, this is the first case of heart failure associated with hypoparathyroidism in which the patient recovered significantly after the correction of hypocalcemia, providing strong evidence to support our hypothesis of hypocalcemic myocardiopathy.

Unusual association between increased bone resorption and presence of paroxysmal nocturnal hemoglobinuria phenotype in multiple myeloma.

Paroxysmal nocturnal hemoglobinuria (PNH) clones deficient in glycosylphosphatidylinositol-anchored molecules, including CD55 and CD59, have been previously described in patients with multiple myeloma (MM). The aim of this study was to investigate the possible association between existence of the PNH phenotype and myeloma bone disease. Forty-three patients with newly diagnosed MM were the subjects of the study. Radiographic evaluation of the skeleton was performed in all patients at diagnosis. The following biochemical markers were measured: bone resorption markers (tartrate-resistant acid phosphatase isoform 5b [TRACP-5b]and N-terminal cross-linking telopeptide of type-I collagen [NTX]), bone formation markers (bone alkaline phosphatase [bALP] and osteocalcin [OC]), osteoprotegerin (OPG), soluble receptor activator of nuclear factor KB ligand (sRANKL), and interleukin 6 (IL-6). Detection of CD55- and/or CD59-deficient red cell populations was performed after diagnosis. Patients with MM had elevated mean baseline NTX, TRACP-5b, sRANKL, and IL-6 levels compared with controls, whereas the mean values of bALP, OC, and OPG were significantly decreased. Four patients had no osteolytic lesions, whereas 8 patients had 1 to 3 lytic lesions, and 31 patients had more than 3 lytic lesions and/or pathologic fractures in the skeletal survey. CD55- and/or CD59-deficient red cell populations were observed in 56% of patients with MM. There was a strong correlation between the presence of PNH-like erythrocytes and increased bone resorption, as measured by NTX, TRACP-5b, and sRANKL/OPG ratio (P < .03, P < .02, and P < .02, respectively). There was also a significant correlation between PNH phenotype and severe bone disease (P < .02). These results suggest that there is a possible link between PNH phenotype and increased osteoclastic activity in MM owing to a potential effect of myeloma microenvironment on a preexisting PNH clone. Further studies are required for clarifying this phenomenon and investigating possible mechanisms of this unusual association.

Red cells with paroxysmal nocturnal hemoglobinuria-phenotype in patients with acute leukemia.

CD55 and CD59 are complement regulatory proteins that are linked to the cell membrane via a glycosyl-phosphatidylinositol anchor. They are reduced mainly in paroxysmal nocturnal hemoglobinuria (PNH) and in other hematological disorders. However, there are very few reports in the literature concerning their expression in patients with acute leukemias (AL). We studied the CD55 and CD59 expression in 88 newly diagnosed patients with AL [65 with acute non-lymphoblastic leukemia (ANLL) and 23 with acute lymphoblastic leukemia (ALL)] using the sephacryl gel test, the Ham and sucrose lysis tests and we compared the results with patients' clinical data and disease course. Eight patients with PNH were also studied as controls. Red cell populations deficient in both CD55 and CD59 were detected in 23% of ANLL patients (especially of M(0), M(2) and M(6) FAB subtypes), 13% of ALL and in all PNH patients. CD55-deficient erythrocytes were found in 6 ANLL patients while the expression of CD59 was decreased in only 3 patients with ANLL. No ALL patient had an isolated deficiency of these antigens. There was no correlation between the existence of CD55 and/or CD59 deficiency and the percentage of bone marrow infiltration, karyotype or response to treatment. However no patient with M(3), M(5), M(7) subtype of ANLL and mature B- or T-cell ALL showed a reduced expression of both antigens. The deficient populations showed no alteration after chemotherapy treatment or during disease course. This study provides evidence about the lower expression of CD55 and CD59 in some AL patients and the correlation with their clinical data. The possible mechanisms and the significance of this phenotype are discussed.

Detection of CD55- and/or CD59-deficient red cell populations in patients with plasma cell dyscrasias.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disorder characterized by a decrease or absence of glycosylphosphatidylinositol (GPI)-anchored molecules such as CD55 and CD59 from the surface of affected cells, resulting in intravascular hemolysis, cytopenia, and venous thrombosis. A PNH-like phenotype has been detected in various hematological disorders, mainly in aplastic anemia and myelodysplastic syndromes, but also in lymphoproliferative syndromes (LPSs). To the best of our knowledge, CD55- or CD59-deficient red cells have not been detected in plasma cell dyscrasias (PCDs). The aim of this study was the detection of CD55- and/or CD59-deficient red cell populations in patients with PCD. Seventy-seven patients were evaluated; 62 with multiple myeloma (MM), 7 with Waldenstrom macroglobulinemia (WM), 6 with monoclonal gammopathy of undetermined significance (MGUS), and 2 with heavy chain disease (HCD). The sephacryl gel microtyping system was applied; Ham and sucrose lysis tests were also performed on all samples with CD55- or CD59-negative populations. Red cells deficient in both molecules were detected in 10 (12.9%) of 77 patients with PCD: 2 (28.6%) of 7 with WM, 1 (16.6%) of 6 with MGUS, 6 (9.6%) of 62 with MM, and 1 of 2 patients with HCD. Isolated CD55 deficiency was found in 28.5% of all PCD patients, whereas isolated CD59 deficiency was not observed in any patients. These findings illustrate the existence of the PNH phenotype in the red cells of patients with PCD; further investigation is needed into the mechanisms and significance of this phenotype.