Analysis of EEG signals by combining eigenvector methods and multiclass support vector machines

A new approach based on the implementation of multiclass support vector machine (SVM) with the error correcting output codes (ECOC) is presented for classification of electroencephalogram (EEG) signals. In practical applications of pattern recognition, there are often diverse features extracted from raw data which needs recognizing. Decision making was performed in two stages: feature extraction by eigenvector methods and classification using the classifiers trained on the extracted features. The aim of the study is classification of the EEG signals by the combination of eigenvector methods and multiclass SVM. The purpose is to determine an optimum classification scheme for this problem and also to infer clues about the extracted features. The present research demonstrated that the eigenvector methods are the features which well represent the EEG signals and the multiclass SVM trained on these features achieved high classification accuracies.     

Usage of eigenvector methods to improve reliable classifier for Doppler ultrasound signals

A new approach based on the implementation of the automated diagnostic systems for Doppler ultrasound signals classification with the features extracted by eigenvector methods is presented. In practical applications of pattern recognition, there are often diverse features extracted from raw data which needs recognizing. Because of the importance of making the right decision, the present work is carried out for searching better classification procedures for the Doppler ultrasound signals. Decision making was performed in two stages: feature extraction by the eigenvector methods and classification using the classifiers trained on the extracted features. The aim of the study is classification of the Doppler ultrasound signals by the combination of eigenvector methods and the classifiers. The present research demonstrated that the power levels of the power spectral density (PSD) estimates obtained by the eigenvector methods are the features which well represent the Doppler ultrasound signals and the probabilistic neural networks (PNNs), recurrent neural networks (RNNs) trained on these features achieved high classification accuracies.     

The differentiation of human T(H)-17 cells requires transforming growth factor-beta and induction of the nuclear receptor RORgammat

T(H)-17 cells are interleukin 17 (IL-17)-secreting CD4+ T helper cells involved in autoimmune disease and mucosal immunity. In naive CD4+ T cells from mice, IL-17 is expressed in response to a combination of IL-6 or IL-21 and transforming growth factor-beta (TGF-beta) and requires induction of the nuclear receptor RORgammat. It has been suggested that the differentiation of human T(H)-17 cells is independent of TGF-beta and thus differs fundamentally from that in mice. We show here that TGF-beta, IL-1beta and IL-6, IL-21 or IL-23 in serum-free conditions were necessary and sufficient to induce IL-17 expression in naive human CD4+ T cells from cord blood. TGF-beta upregulated RORgammat expression but simultaneously inhibited its ability to induce IL-17 expression. Inflammatory cytokines relieved this inhibition and increased RORgammat-directed IL-17 expression. Other gene products detected in T(H)-17 cells after RORgammat induction included the chemokine receptor CCR6, the IL-23 receptor, IL-17F and IL-26. Our studies identify RORgammat as having a central function in the differentiation of human T(H)-17 cells from naive CD4+ T cells and suggest that similar cytokine pathways are involved in this process in mice and humans.     

Medical education in Turkey: past to future

Although medical education in the Republic of Turkey appears to be relatively new, there is almost 500 years of background development within the Anatolian region. Turkey has faced many difficulties in its past and present times, related to its vast and diverse geography, its crowded population, and the many ethnic groups that constitute its population. As in many other countries throughout the world, medical education in Turkey has recently been debated, reviewed and renewed. This article gives a general overview of the history of medical education and the present situation in Turkish medical schools; the quality and professionalism of medical education within the medical system, from the perspectives of undergraduate, postgraduate and continuing medical education; and an overview of the challenges and opportunities that presently exist.     

Detecting early changes in choroidal vascularity and thickness using optical coherence tomography in patients with corneal crosslinking for keratoconus

AIM: To investigate changes in choroidal thickness and vascularity in keratoconus patients treated with corneal crosslinking. METHODS: This study evaluated 28 eyes of 22 patients with keratoconus who underwent corneal crosslinking. The choroidal thicknesses were evaluated on enhanced depth imaging optical coherence tomography at the preoperative and postoperative 3d, 1, and 3mo. Choroidal thickness in the four cardinal quadrants and the fovea were evaluated. The choroidal vascularity index was also calculated. RESULTS: There was no significant difference in central choroidal thickness between the preoperative and postoperative 3d, 1mo (P>0.05). There was a significant increase in the 3mo (P=0.034) and a significant decrease in the horizontal choroidal vascularity index on the postoperative 3d (P=0.014), there was no statistically significant change in vertical axes and other visits in horizontal sections (P>0.05). CONCLUSION: This study sheds light on choroidal changes in postoperative corneal crosslinking for keratoconus. While it suggests the procedure’s relative safety for submacular choroid, more extensive research is necessary to confirm these findings and their clinical significance.     

Effect of zoledronic acid on serum angiogenic factors in patients with bone metastases

In this study we have investigated changes in circulating angiogenic factors after a single zoledronic acid intravenous infusion. Thirty consecutive patients who had histologically confirmed breast (n = 20) and lung cancer (n = 10) associated with confirmation of bone metastases were included in the study. Serum was also available from 10 healthy volunteers. Four mg of Zoledronic acid (Zometa, Novartis) was administered as a 15-min infusion in 100-ml normal saline on an outpatient basis. Venous blood for assessment of serum parameters was drawn just before the beginning of drug infusion and again at 7 and 28 days after the zoledronic acid infusion. Serum levels of VEGF and bFGF were assayed with ELISA kits. Serum VEGF and bFGF levels were not significantly different from healthy control groups (P > 0.05). However, we found that serum VEGF levels in lung cancer patients were significantly higher than in patients with breast cancer and controls (P = 0.009, and P = 0.022, respectively). We found no significant correlation between serum VEGF and bFGF levels. No statistically significant changes were seen following infusion of zoledronic acid in patients with bone metastases for both serum VEGF and bFGF levels (P > 0.05). Unlike previous studies, zoledronic acid did not appear to exert an angiogenic activity as there was no reduction of VEGF and bFGF circulating levels after zoledronic acid infusion.     

A sewing needle migrating into the liver in a child: case report and review of the literature

Swallowing foreign bodies is a common problem in children. Although most objects pass through the gastrointestinal tract with no untoward effect; long, sharp-pointed, or slender objects can perforate the gut. Migration of an object to the liver is extremely rare and very few cases have been reported in the literature. The aim of this study is to draw attention to this subject once again by contributing a case report of a child with a hepatic sewing needle. A survey of the literature over the period from 1971 to 2006 revealed a total of five cases of childhood hepatic sewing needle together with our case. The practical lesson illustrated by this report is that the surgeon must carefully evaluate the liver when foreign body was not found in gastrointestinal system and also perforation site was found anywhere.     

Targeted sequencing with expanded gene profile enables high diagnostic yield in non‐5q‐spinal muscular atrophies

Spinal muscular atrophies (SMAs) are a heterogeneous group of disorders characterized by muscular atrophy, weakness, and hypotonia due to suspected lower motor neuron degeneration (LMND). In a large cohort of 3,465 individuals suspected with SMA submitted for SMN1 testing to our routine diagnostic laboratory, 48.8% carried a homozygous SMN1 deletion, 2.8% a subtle mutation, and an SMN1 deletion, whereas 48.4% remained undiagnosed. Recently, several other genes implicated in SMA/LMND have been reported. Despite several efforts to establish a diagnostic algorithm for non‐5q‐SMA (SMA without deletion or point mutations in SMN1 [5q13.2]), data from large‐scale studies are not available. We tested the clinical utility of targeted sequencing in non‐5q‐SMA by developing two different gene panels. We first analyzed 30 individuals with a small panel including 62 genes associated with LMND using IonTorrent‐AmpliSeq target enrichment. Then, additional 65 individuals were tested with a broader panel encompassing up to 479 genes implicated in neuromuscular diseases (NMDs) with Agilent‐SureSelect target enrichment. The NMD panel provided a higher diagnostic yield (33%) than the restricted LMND panel (13%). Nondiagnosed cases were further subjected to exome or genome sequencing. Our experience supports the use of gene panels covering a broad disease spectrum for diseases that are highly heterogeneous and clinically difficult to differentiate.