Pelagia Vorgia

The impact of mode of delivery and gestational age on cord blood hematopoietic stem/progenitor cells.

Human cord blood has been successfully used as an alternative source of hematopoietic stem cells suitable for transplantation. The aim of this study was to assess the impact of gestational age and the mode of delivery on cord blood hematopoietic stem/progenitor cell characteristics. The mode of delivery does not seem to affect either the replating capacity of hematopoietic progenitors colony-forming unit-granulocyte-macrophage or the cord blood content in CD34+ cells. The higher percentage of CD34+ cells in cord blood from preterm deliveries compared to full-term ones indicates that hematopoietic progenitors from preterm cord blood may be suitable for transplantation. These findings should be taken into consideration when selection of cord blood units is required for potential use in transplantation.

In vitro proliferative and differentiating characteristics of CD133+ and CD34+ cord blood cells in the presence of thrombopoietin (TPO) or erythropoietin (EPO): Potential implications for hematopoietic cell transplantation

We investigated the characteristics of cord blood (CD) CD133(+) and CD34(+) cells, by flow cytometry, clonogenic assays and assessment of the replating ability (area under the curve (AUC)) following 7-day liquid culture in the presence of early acting growth factors and either thrombopoietin (TPO) or erythropoietin (EPO). The CD34(+) population showed a more effective proliferation in all parameters tested and TPO proved to be more effective than EPO. On the contrary, the CD133(+) cell fraction retained and expanded more immature elements in a modest but consistent manner with either TPO or EPO. We conclude that CD133(+) and CD34(+) expanded cord blood cells could potentially be used in combination to overcome the shortcomings of cord blood transplantation in older children and adults.

Absence seizure epilepsy detection using linear and nonlinear eeg analysis methods

In this study, we investigated three measures capable of detecting absence seizures with increased sensitivity based on different underlying assumptions. Namely, an information-based method known as Approximate Entropy, a nonlinear alternative (Order Index), and a linear variance analysis approach. The results on the long-term EEG data suggest increased accuracy in absence seizure detection achieving sensitivity as high as 97.33% with no further application of any sophisticated classification scheme.

An approach to absence epileptic seizures detection using Approximate Entropy

Epilepsy is one of the most common chronic neurological diseases and the most common neurological chronic disease of childhood. The electroencephalogram (EEG) signal provides significant information neurologists take into consideration in the investigation and analysis of epileptic seizures. The Approximate Entropy (ApEn) is a formulated statistical parameter commonly used to quantify the regularity of a time series data of physiological signals. In this paper ApEn is used in order to detect the onset of epileptic seizures. The results show that the method provides promising results towards efficient detection of onset and ending of seizures, based on analyzing the corresponding EEG signals. ApEn parameters affect the methods behavior, suggesting that a more detailed study and a consistent methodology of their determination should be established. A preliminary analysis for the proper determination of these parameters is performed towards improving the results.

Vision-based absence seizure detection

In order to diagnose epilepsy, neurologists rely on their experience, performing an equal assessment of the electroencephalogram and the clinical image. Since misdiagnosis reaches a rate of 30% and more than one-third of all epilepsies are poorly understood, a need for leveraging diagnostic precision is obvious. With the aim at enhancing the clinical image assessment procedure, this paper evaluates the suitability of certain facial expression features for detecting and quantifying absence seizures. These features are extracted by means of time-varying signal analysis from signals that are gained by applying computer vision techniques, such as face detection, dense optical flow computation and averaging background subtraction. For the evaluation, video sequences of four patients with absence seizures are used. The classification performance of a C4.5 decision tree shows accuracies of up to 99.96% with a worst percentage of incorrectly classified instances of 0.14%.

Vision-based human motion analysis in epilepsy - Methods and challenges

Motion is one of the most important characteristics in clinical epileptology. In developing an integrated motion analysis system for epileptic patients or children with neurological disorders (e.g. ADHD) we surveyed and analyzed current efforts in vision-based human motion analysis in epilepsy as well as all possible forms of motion typically encountered in known epileptic syndromes. This paper presents the results in a systematic way, and includes a critical discussion of methodological and scientific challenges that need to be addressed in this particular domain.

A8344G tRNALys mutation associated with recurrent brain stem stroke-like episodes

JO N 2921 the presence of the tRNALys A8344G mutation. This 17-year-old patient had normal growth until eight years of age when sensorineural deafness, gait instability, easy fatigability, difficulty with fine movements of the hands, as in writing, failure to grow and hypothyroidism gradually developed. At the age of 12 years, valproic acid was administered due to seizures. She showed increased serum and CSF lactate and increased urinary excretion of amino acids. A muscle biopsy was declined. At the age of 14 years lamotrigine was given, due to increased seizure frequency and, later, levetiracetam was substituted for valproic acid. At 16 years of age lack of menarche, polycystic ovaries and myoclonic jerks were noted. In September 2006, she developed diplopia that lasted for approximately 20 days. In January 2007, the patient was admitted to our service because of dysarthria, dysphagia, respiratory difficulties and worsening of gait ataxia. On examination, there was marked slowness of the saccadic eye movements with the smooth pursuit being less affected. Convergence was impaired. Speech was dysarthric and dysrhythmic, the gag reflex diminished bilaterally and the palate high arched. Deep tendon reflexes were markedly increased, with sustained ankle clonus and extensor plantar responses. Postural and intention tremor and dysmetria and dysdiachokinesia were present on all four extremities. Pes cavus was observed bilaterally. Due to respiratory difficulties associated with repeated respiratory infections, a tracheostomy was performed and the patient received mechanical ventilation intermittently. Bulbar function gradually improved. Brain MRIs in March 2006 and in September 2006 showed a focal, non-enhancing, T2 hyperintense Ioannis Zaganas Helen Latsoudis Eufrosini Papadaki Pelagia Vorgia Martha Spilioti Andreas Plaitakis

Exploiting advanced video analysis technologies for a smart home monitoring platform for epileptic patients: Technological and legal preconditions

Current advances in video surveillance systems for health purposes at patients homes, usually for the elderly and patients with chronic conditions, in conjunction with the latest achievements in vision-based human activity monitoring and motion analysis, create exciting opportunities and novel service-scenarios for the home monitoring of patients with epilepsy. Such innovative service platforms are to be used for predictive/diagnostic purposes, by enabling the quantified analysis and classification of clinical manifestations, or for the efficient treatment of patients, by supporting clinicians to better assess response to therapy. Ultimately, such platforms enhance the overall monitoring scheme of a patient usually performed by caring persons, who might occasionally miss an epileptic event. This paper discusses the technological and legal preconditions for such a platform, based on current research results for the detection of absence seizures in conjunction with the expertise on ethico-legal matters for translational research gained through the CONTRACT project.

Model-free vision-based facial motion analysis in epilepsy

The assessment of an epileptic patients clinical image during seizure manifestations is equally important for a correct disease diagnosis as are the findings in the electroencephalogram (EEG). So far, the EEG has been studied extensively and these efforts have brought significant benefits in epileptology by providing well defined patterns, quantitatively describing epileptic events. The same cannot be stated regarding the acquisition of quantifiable descriptions of a patients clinical image. This paper introduces and evaluates vision-based approaches for the automatic extraction of quantitative features describing facial motion in the domain of epilepsy.

Screening for TSC1 and TSC2 mutations using NGS in Greek children with tuberous sclerosis syndrome

Tuberous Sclerosis Complex (TSC) is a rare neurocutaneous syndrome inherited by an autosomal dominant manner. The disorder is commonly manifested by the presence of multiple benign tumors located in numerous tissues, including the brain, heart, skin and kidneys. Seizures, autism, developmental and behavioral delay, as well as non-neurological phenotypic findings, are suggestive of TSC. The identification of one pathogenic mutation in either the TSC1 or TSC2 genes is considered to be an independent diagnostic criterion. In our study, seventeen Greek patients, 2yo on average, were analyzed for the presence of pathogenic germline mutations in the aforementioned loci by Next-Generation Sequencing. A TSC1/2 gene panel was designed for the molecular diagnosis of the disease. Patients underwent initial diagnosis based on their clinical symptoms, most frequently involving the presence of skin lesions and/or epilepsy. Only one case was familial. Sixteen different genetic alterations were identified in TSC1 and TSC2 genes in fifteen patients, giving a 88% detection rate by employing NGS technology. Overall, most pathogenic mutations (11/15) identified were located in the TSC2 gene with exon 41 being the most frequent. With respect to genotype-phenotype association, no patient TSC1 (+) developed SEGA or renal cysts. No significant differences were observed between different types of TSC2 mutations and any clinical feature. Sequencing also revealed 18 different SNPs across the TSC1 and 20 across the TSC2 genes. This is the first registry of the genetic profile of TSC patients in Greece using a custom-made gene panel as molecular diagnostic tool.