102 research outputs found

    Automatic epilepsy detection using fractal dimensions segmentation and GP-SVM classification

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    Objective: The most important part of signal processing for classification is feature extraction as a mapping from original input electroencephalographic (EEG) data space to new features space with the biggest class separability value. Features are not only the most important, but also the most difficult task from the classification process as they define input data and classification quality. An ideal set of features would make the classification problem trivial. This article presents novel methods of feature extraction processing and automatic epilepsy seizure classification combining machine learning methods with genetic evolution algorithms. Methods: Classification is performed on EEG data that represent electric brain activity. At first, the signal is preprocessed with digital filtration and adaptive segmentation using fractal dimensions as the only segmentation measure. In the next step, a novel method using genetic programming (GP) combined with support vector machine (SVM) confusion matrix as fitness function weight is used to extract feature vectors compressed into lower dimension space and classify the final result into ictal or interictal epochs. Results: The final application of GP SVM method improves the discriminatory performance of a classifier by reducing feature dimensionality at the same time. Members of the GP tree structure represent the features themselves and their number is automatically decided by the compression function introduced in this paper. This novel method improves the overall performance of the SVM classification by dramatically reducing the size of input feature vector. Conclusion: According to results, the accuracy of this algorithm is very high and comparable, or even superior to other automatic detection algorithms. In combination with the great efficiency, this algorithm can be used in real-time epilepsy detection applications. From the results of the algorithm's classification, we can observe high sensitivity, specificity results, except for the Generalized Tonic Clonic Seizure (GTCS). As the next step, the optimization of the compression stage and final SVM evaluation stage is in place. More data need to be obtained on GTCS to improve the overall classification score for GTCS.Web of Science142449243

    Effects of Oxime K203 and Oxidative Stress in Plasma of Tabun Poisoned Rats

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    The highly toxic nature of tabun has been known for many years, but there are still serious limitations to antidotal therapy. In this study, we used rats as an experimental model to evaluate the efficiency of bispyridinium para-oxime K203 as therapy against tabun poisoning as well as to examine if induction of oxidative stress is linked to organophosphate toxicity. K203 showed high potency in counteracting tabun poisoning. Either alone or in combination with atropine, this oxime significantly increased cholinesterase activity at 0.5 and 1 h compared to untreated rats poisoned with tabun. Simultaneous measurements of markers of oxidative stress (lipid peroxidation and superoxide dismutase) showed that tabun poisoning, but also therapy (oxime alone or oxime plus atropine) applied immediately after tabun poisoning, could generate free radical species that may cause oxidative stress in rats. (doi: 10.5562/cca1811

    The potential of medical device industry in technological and economical context

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    The high quality of public health improves not only healthy life expectancy, but also the productivity of labor. The most important part of the health care sector is the medical technology industry. The aim of this study is to analyze the current situation in the medical device industry in Europe, its potential strengths and weaknesses in the context of topical economic and demographic development. The contribution specifies an analysis of the economic state of the medical device industry in the context of demographic development of European Union's macroeconomic indicators and views of experts in the field of medical device development, concerning the opportunities for entities involved in the medical device market. There is fierce competition on the European market. The innovative activity is stable and well regulated by responsible authorities. Worldwide, the medical device market is expected to grow.Web of Science111514150

    Butirilkolinesteraza štiti štakore od inhalacijske izloženosti subletalnim dozama sarina

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    Protection experiments were conducted using different doses of equine serum butyrylcholinesterase (Eq BuChE) as pretreatment in rats. Cholinesterase activities were determined in blood [whole blood, red blood cells (RBC) acetylcholinesterase (AChE), and plasma BuChE] before and after sarin inhalation exposure in untreated rats and those pretreated with Eq BuChE. Brain AChE activity was also determined in the frontal cortex, basal ganglia and pontomedullar areas following exposure. Dose-dependent increases in plasma BuChE activity and no changes in the RBC and brain AChE activities were demonstrated following i.p. injection of different amounts of Eq BuChE. Decreases in plasma BuChE activity and RBC and brain AChE activities were observed in control rats following sarin inhalation exposure. In rats pretreated with Eq BuChE this inhibition was lower than in control animals. These results demonstrate protective effects of Eq BuChE pretreatment in rats intoxicated with sublethal concentrations of sarin by inhalation.U ovome su radu na štakorima istražene mogućnosti profilakse butirilikolinesterazom iz konjskog seruma (Eq BuChE) u različitim dozama. Aktivnost kolinesteraza izmjerena je u krvi (punoj krvi, eritrocitima i plazmi) prije i nakon inhalacije sarina u štakora koji su prethodno primili Eq BuChE. Također je nakon izlaganja sarinu mjerena aktivnost acetilkolinesteraze u tkivu uzetom iz čeonog režnja mozga štakora, bazalnih ganglija i pontomedularnog područja. Nakon primjene različitih doza Eq BuChE utvrđen je porast aktivnosti butirilkolinesteraze u plazmi koji je odgovarao dozi, ali nije bilo promjena u aktivnosti acetilkolinesteraze u eritrocitima i moždanom tkivu. U kontrolnih je štakora zamijećen pad aktivnosti butirilkolinesteraze u plazmi te acetilkolinesteraze u eritrocitima i moždanom tkivu nakon njihova izlaganja sarinu inhalacijskim putem. U štakora koji su primili profilaksu Eq BuChE ova je inhibicija bila slabija. Rezultati istraživanja potvrđuju zaštitna svojstva konjske butirilkolinesteraze kao profilakse pri otrovanju štakora subletalnim dozama sarina

    Complexity stage model of the medical device development based on economic evaluation-MedDee

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    The development of a new product is essential for the progress and success of any company. The medical device market is very specific, which is challenging. Therefore, this paper assesses an economic model for medical device evaluation using the economic, health, technology regulatory, and present market knowledge to enable the cost-time conception for any applicant. The purpose of this study is to propose a comprehensive stage model of the medical device development to subsequently describe the financial expenditure of the entire development process. The identification of critical steps was based on the literature review, and analysis, and a comparison of the available medical device development stages and directives. Furthermore, a preliminary assessment of the medical device development steps and procedures on the basis of the interviews was performed. Six interviews were conducted with an average duration of one hour, focusing on areas: relevance and level of detail of the medical device development stages, involvement of economic methods, and applicability of the proposed model. Subsequently, the improvement and modification of the medical device investment process, based on respondents' responses, were conducted. The authors have proposed the complexity model MedDee-Medical Devices Development by Economic Evaluation. This model is comprised of six phases: initiation, concept, design, production, final verification, and market disposition in which the economic methods are incorporated.Web of Science125art. no. 175

    Usporedno određivanje učinkovitosti bispiridinijevih oksima pri trovanju paraoksonom

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    The inability of standard therapy to provide adequate protection against poisoning by organophosphorus compounds (pesticides and nerve agents) motivated us to search for new, more effective oximes. We investigated the pharmacotoxicological properties of six experimental K-oximes (K027, K033, K048, K074, K075, and K203) in vivo. The therapeutic efficacy of K-oximes (at doses of 5 or 25 % of their LD50) combined with atropine was assessed in paraoxon-poisoned mice and compared with conventionally used oximes HI-6 and TMB-4. The bisoxime K074 was the most toxic (LD50=21.4 mg kg-1) to mice, while monoxime K027 was the least toxic (LD50=672.8 mg kg-1). With the exception of K033, all of the tested K-oximes showed better therapeutic efficiency than HI-6 and TMB-4. K027 and K048 stood out by demonstrating low acute toxicities and ensuring protective indices ranging from 60.0 to 100.0 LD50 of paraoxon. Taking into account that these two oximes showed a similar therapeutic efficacy regardless of the applied doses, our results suggest that K027 and K048 could be antidotes for paraoxon intoxication.Činjenica da standardna terapija ne omogućuje dovoljnu zaštitu pri otrovanju organofosfornim spojevima (pesticidima i živčanim bojnim otrovima) potaknula nas je na istraživanje novih, učinkovitijih oksima. U uvjetima in vivo ispitali smo farmakotoksikološka svojstva šest eksperimentalnih K-oksima (K027, K033, K048, K074, K075 i K203). Terapijski učinak kombinacije K-oksima (primjenjenih u dozi 5 ili 25 % njihove LD50) i atropina testiran je na miševima otrovanim paraoksonom i uspoređen s konvencionalnim oksimima HI-6 i TMB-4. Bisoksim K074 je bio najtoksičniji (LD50=21.4 mg kg-1) za miševe, dok je monooksim K027 bio najmanje toksičan (LD50=672.8 mg kg-1). Osim K033, svi K-oksimi pokazali su bolji terapijski učinak u miševa trovanih paraoksonom u odnosu na HI-6 i TMB-4. Iz skupine testiranih oksima istaknuli su se K027 i K048 koji su pokazali nisku akutnu toksičnost i osigurali protektivne indekse u rasponu od 60.0 do 100.0 LD50 paraoksona. Uzmemo li u obzir da su ta dva oksima pokazala sličan terapijski učinak bez obzira na primjenjenu dozu, prikazani rezultati upućuju na K027 i K048 kao perspektivne antidote u terapiji trovanja paraoksonom

    Synthesis and disinfection effect of the pyridine-4-aldoxime based salts

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    PubMed ID: 25719739A set of new quaternary ammonium compounds based on pyridine-4-aldoxime was synthesized, characterized with analytical data (NMR, EA, HPLC, MS) and tested for in vitro antimicrobial activity (antibacterial, antifungal) and cytotoxicity. Quaternary pyridinium-4-aldoxime salts with length of alkyl side chain from C8 to C20 and belonging to the group of cationic surfactants were investigated in this work. An HPLC experimental protocol for characterization of mixtures of all homologues has been found. Antimicrobial evaluation found that yeast-type fungi were most sensitive towards C14 and C16 analogues, whereas the C16 analogue was completely ineffective against filamentous fungi. Antibacterial assessment showed versatility of C14 and relatively high efficacy of C16 against G+ strains and C14 against G− strains. Notably, none of the studied compounds exceeded the efficacy and versatility of the benzalkonium C12 analogue, and benzalkonium analogues also exhibited lower cytotoxicity in the cell viability assay.Web of Science2033696368

    Supstituirani monokvaterni oksimi kao reaktivatori acetilkolinesteraze inhibirane ciklosarinom i klorpirifosom

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    This paper describes an in vitro study of three potential acetylcholinesterase (AChE; EC 3.1.1.7) reactivators derived from a monoquaternary reactivator pralidoxime. Compounds used were pyridinium-2-aldoxime-4- carbamoyl-N-methyl iodide (TO231), pyridinium-2-aldoxime-4-ethoxycarbonyl-N-methyl iodide (TO237), and pyridinium-2-aldoxime-5-ethoxycarbonyl-N-methyl iodide (TO238). Pralidoxime and obidoxime were used for comparison. Nerve agent cyclosarin and pesticide chlorpyrifos were used as organophosphorus cholinesterase inhibitors. The source of AChE was rat brain homogenate. None of the tested oximes was able to reactivate cyclosarin-inhibited AChE (at 1.0 mmol L-1 oxime concentration). In case of chlorpyrifos, TO231 was the most potent AChE reactivator with an 82 % reactivation at 1.0 mmol L-1 oxime concentration. This reactivating potency equals that of pralidoxime and obidoxime. TO238 was less effective, and TO237 did not reactivate chlorpyrifos-inhibited AChE at all. None of the tested AChE reactivators, reference compounds included, could be considered universal for both chlorpyrifos- and cyclosarin-inhibited AChE.U ovome in vitro istraživanju testiran je reaktivacijski potencijal triju reaktivatora acetilkolinesteraze (AChE; EC 3.1.1.7) dobivenih iz monokvaternog reaktivatora pralidoksima. Testirani su sljedeći spojevi: 4-karbamoil-2-aldoksim-1-metilpiridinijev jodid (TO231), 4-etoksikarbonil-2-aldoksim-1-metilpiridinijev jodid (TO237) te 5-etoksikarbonil-2-aldoksim-1-metilpiridinijev jodid (TO238). Za usporedbu su uzeti pralidoksim i obidoksim. Kao inhibitori kolinesteraze rabljeni su živćani otrov ciklosarin i pesticid klorpirifos. Izvor acetilkolinesteraze bio je homogenat mozga štakora. Nijedan od testiranih oksima nije uspio reaktivirati acetilkolinesterazu inhibiranu ciklosarinom pri koncentraciji oksima od 1.0 mmol L-1. Kod inhibicije klorpirifosom TO231 pokazao se najsnažnijim reaktivatorom acetilkolinesteraze s reaktivacijom od 82 % pri koncentraciji oksima od 1.0 mmol L-1. Ovaj reaktivacijski potencijal jednak je onomu pralidoksima i obidoksima. Slabiju je djelotvornost iskazao TO238, a TO237 nije uspio reaktivirati acetilkolinesterazu inhibiranu klorpirifosom. Stoga nijedan od testiranih spojeva (uključujući i referentne oksime) ne može služiti kao univerzalni reaktivator acetilkolinesteraze inhibirane klorpirifosom i ciklosarinom

    Simvastatin Inhibits Endotoxin-Induced Apoptosis in Liver and Spleen Through Up-Regulation of Survivin/NF-κB/p65 Expression

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    Endotoxemia is associated by dysregulated apoptosis of immune and non-immune cells. We investigated whether simvastatin has anti-apoptotic effects, and induces hepatocytes and lymphocytes survival signaling in endotoxin-induced liver and spleen injuries. Wistar rats were divided into the groups pretreated with simvastatin (20 or 40 mg/kg, orally) prior to a non-lethal dose of lipopolysaccharide (LPS), the LPS group, and the control. The severity of tissue inflammatory injuries was expressed as hepatic damage scores (HDS) and spleen damage scores (SDS), respectively. The apoptotic cell was detected by TUNEL (Terminal deoxynucleotidyl transferase dUTP Nick End Labeling) and immunohistochemical staining (expression of cleaved caspase-3, and anti-apoptotic Bcl-xL, survivin and NF-κB/p65). Simvastatin dose-dependently abolished HDS and SDS induced by LPS (p < 0.01), respectively. Simvastatin 40 mg/kg significantly decreased apoptotic index and caspase-3 cleavage in hepatocytes and lymphocytes (p < 0.01 vs. LPS group, respectively), while Bcl-XL markedly increased accordingly with simvastatin doses. In the simvastatin, groups were determined markedly increased cytoplasmic expression of survivin associated with nuclear positivity of NF-κB, in both hepatocytes and lymphocytes (p < 0.01 vs. LPS group). Cell-protective effects of simvastatin against LPS seemed to be mediated by up-regulation of survivin, which leads to reduced caspase-3 activation and inhibition of hepatocytes and lymphocytes apoptosis
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