33 results on '"Siska, E."'
Search Results
2. Vestibular schwannoma: natural growth and possible predictive factors
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Siska E. Dhaese, Hannah Keppler, Wouter Bauters, Ingeborg Dhooge, Heleen Parmentier, Veroniek Van Driessche, Dirk Van Roost, and Sandrien Van Vooren
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Adult ,Male ,medicine.medical_specialty ,Acoustic neuroma ,Schwannoma ,Conservative Treatment ,Severity of Illness Index ,Cohort Studies ,Predictive Value of Tests ,medicine ,Humans ,Tumor growth ,Watchful Waiting ,Aged ,Retrospective Studies ,Vestibular system ,Natural course ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,Retrospective cohort study ,Neuroma, Acoustic ,General Medicine ,Middle Aged ,Prognosis ,medicine.disease ,Magnetic Resonance Imaging ,Treatment Outcome ,Otorhinolaryngology ,Disease Progression ,Female ,Radiology ,Otologic Surgical Procedures ,business - Abstract
Background: Prediction of vestibular schwannoma (VS) growth would allow for a more differentiated follow-up protocol. Objectives: The natural course of a VS and predictive factors of growth are investigated. Methods: Sixty-two sporadic VS cases diagnosed between 2003 and 2015 were included in this retrospective cohort study. After initial surveillance, active therapy was initiated in 31/62 patients. Regular magnetic resonance images (MRIs) were performed. Two mm/year linear difference was the cut-off value for significant growth. The STROBE guidelines have been implemented. Results: Growth of the tumor was detected in 56% of patients and mainly observed in the first three years of follow-up. Tumor size remained stable in 34% and decreased in 10% of patients. No baseline information, symptom, or sign was found to be predictive for growth. Conclusions: In 56% of the initially conservatively managed VSs growth was observed and active treatment was initiated. Eighty-seven percent of the growing VSs were identified during the first three years of follow-up. The initially larger VSs seemed to grow faster and needed active treatment earlier during follow-up. No predicting factors for growth identified from the literature could be confirmed in the present study. Serial MRI remains the appropriate method to detect tumor growth.
- Published
- 2019
3. The effect of substrate consumption on the increasing of biofloculans productivity and activity of cultivation by Alcaligenes latus.
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Sumarno, L, Rudiyono, Nurlaila, and Siska, E
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- 2022
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4. Scleral shape and its correlation with corneal parameters in keratoconus
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Alejandra Consejo, Siska E. Dhaese, and Elke O. Kreps
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medicine.medical_specialty ,Keratoconus ,genetic structures ,Ocular surgery ,law.invention ,Cornea ,law ,Ophthalmology ,medicine ,Humans ,Peripheral cornea ,Keratometer ,business.industry ,Annulus (oil well) ,Astigmatism ,Corneal Topography ,General Medicine ,medicine.disease ,Sagittal plane ,eye diseases ,Sclera ,medicine.anatomical_structure ,Lens (anatomy) ,sense organs ,Human medicine ,business ,Optometry - Abstract
Purpose: To assess the correlation of the scleral shape and corneal tomographic parameters in keratoconus. Methods: Twenty eyes of 15 keratoconus patients with no previous specialty lens wear or ocular surgery were included in this study. Corneal imaging was obtained with the Pentacam HR and three-dimensional (3D) corneoscleral maps were acquired using the Eye Surface Profiler, ESP. Sagittal height was calculated at the central corneal level (annulus of 0 & ndash;4 mm radius), peripheral cornea (annulus 4 & ndash;6 mm radius) and sclera (annulus 6 & ndash;8 mm radius) using ESP maps and Pentacam HR (exclusively for the central cornea). The flattest and steepest regions of each annulus and the circumferential scleral asymmetry were calculated based on custom-made software. The Pearson correlation coefficient (r) was used to evaluate the correlation between corneal parameters as measured by Pentacam HR and scleral asymmetry. Results: Anterior corneal parameters, such as flattest and steepest keratometry, were found to be correlated with scleral asymmetry in keratoconus (all r>0.5, p < 0.05). In contrast, anterior astigmatism showed poor correlation with the level of scleral irregularity (r=-0.11; p = 0.32). Other disease-specific parameters pertaining to the posterior corneal curvature and corneal thickness were not correlated with scleral asymmetry. The steepest regions of the central cornea, peripheral cornea, and sclera tended to share a common angle (r = 0.92; p < 0.001 for central cornea compared to sclera). Conclusion: Anterior corneal parameters measured by corneal imaging are associated with the level of scleral asymmetry and the orientation of the steepest area of the sclera in eyes with keratoconus.
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- 2021
5. Optimization Sonication Time and Dilution Factor in Determining the Concentration of Endotoxin Challenge Vial with Kinetic Turbidimetric Method
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Novi, F, primary, Yati, S, additional, Siska, E, additional, and Agie, A G, additional
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- 2021
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6. Scleral shape and its correlation with corneal parameters in keratoconus
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Dhaese, Siska E., primary, Kreps, Elke O., additional, and Consejo, Alejandra, additional
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- 2020
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7. The typical MERRF (A8344G) mutation of the mitochondrial DNA associated with depressive mood disorders
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Molnar, M. J., Perenyi, J., Siska, E., Nemeth, G., and Nagy, Z.
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- 2009
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8. Indirect voltammetric determination of potassium and caesium and direct amperometric determination of potassium with tetraphenylborate using silicone rubber based graphite electrodes
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Siska, E. and Pungor, E.
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- 1971
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9. Potentiometric determination of tetraphenylborate ions with silver nitrate. Determination of silver, potassium and thallium(I)
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Siska, E. and Pungor, E.
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- 1971
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10. Challenges for the genetic screening in dysferlin deficiency – report of an instructive case and review of the literature
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Gal, A., primary, Siska, E., additional, Nagy, Z., additional, Karpati, G., additional, and Molnar, M.J., additional
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- 2008
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11. Marked phenotypic variation in a family with a new myelin protein zero mutation
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Szabo, A., primary, Züchner, S., additional, Siska, E., additional, Mechler, F., additional, and Molnar, M.J., additional
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- 2005
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12. Letters
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Ahlgren, C.E., primary, Johnson, A.L., additional, Siska, E., additional, and Himel, J., additional
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- 2003
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13. SIDS: Counseling parents to reduce the risk
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John Carroll and Siska, E. S.
14. Thalamic Dementia (Thalamus-Demenz)
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Siska, E, primary, Gereby, G, additional, and Tariska, S, additional
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- 1987
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15. Potentiometric titration of sodium pentacyanonitrosylferrate(III)
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Siska, E., primary and Pungor, E., additional
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- 1972
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16. Ultrafast Yttrium Hydride Chemistry at High Pressures via Non-equilibrium States Induced by an X-ray Free Electron Laser.
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Siska E, Smith GA, Villa-Cortes S, Conway LJ, Husband RJ, Van Cleave J, Petitgirard S, Cerantola V, Appel K, Baehtz C, Bouffetier V, Dwivedi A, Göde S, Gorkhover T, Konopkova Z, Hosseini-Saber SMA, Kuschel S, Laurus T, Nakatsutsumi M, Strohm C, Sztuk-Dambietz J, Zastrau U, Smith D, Lawler KV, Pickard CJ, Schwartz CP, and Salamat A
- Abstract
Controlling the formation and stoichiometric content of the desired phases of materials has become of central interest for a variety of fields. The possibility of accessing metastable states by initiating reactions by X-ray-triggered mechanisms over ultrashort time scales has been enabled by the development of X-ray free electron lasers (XFELs). Utilizing the exceptionally high-brilliance X-ray pulses from the EuXFEL, we report the synthesis of a previously unobserved yttrium hydride under high pressure, along with nonstoichiometric changes in hydrogen content as probed at a repetition rate of 4.5 MHz using time-resolved X-ray diffraction. Exploiting non-equilibrium pathways, we synthesize and characterize a hydride in a Weaire-Phelan structure type at pressures as low as 125 GPa, predicted using a crystal structure search, with a hydrogen content of 4.0-5.75 hydrogens per cation, that is enthalpically metastable on the convex hull.
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- 2024
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17. Longitudinal monitoring of Torque Teno virus DNAemia in kidney transplant recipients correlates with long-term complications of inadequate immunosuppression.
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Chauvelot L, Barba T, Saison C, Siska E, Kulifaj D, Bakker SJL, Koenig A, Rabeyrin M, Buron F, Picard C, Dijoud F, Manière L, Lina B, Morelon E, Dubois V, and Thaunat O
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- Humans, Male, Female, Middle Aged, Adult, Longitudinal Studies, Aged, Graft Rejection, Immunosuppressive Agents therapeutic use, Immunosuppressive Agents adverse effects, Cohort Studies, Viremia, Torque teno virus genetics, Kidney Transplantation adverse effects, DNA, Viral blood, Transplant Recipients, DNA Virus Infections virology, DNA Virus Infections blood, DNA Virus Infections immunology, Immunosuppression Therapy adverse effects
- Abstract
Optimization of individual immunosuppression, which reduces the risks of both graft loss and patients' death, is considered the best approach to improve long-term outcomes of renal transplantation. Torque Teno Virus (TTV) DNAemia has emerged as a potential biomarker reflecting the depth of therapeutic immunosuppression during the initial year post-transplantation. However, its efficacy in long-term monitoring remains uncertain. In a cohort study involving 34 stable kidney transplant recipients and 124 healthy volunteers, we established lower and upper TTV DNAemia thresholds (3.75-5.1 log10 cp/mL) correlating with T-cell activatability, antibody response against flu vaccine, and risk for subsequent serious infections or cancer over 50 months. Validation in an independent cohort of 92 recipients confirmed that maintaining TTV DNAemia within this range in >50% of follow-up time points was associated with reduced risks of complications due to inadequate immunosuppression, including de novo DSA, biopsy-proven antibody-mediated rejection, graft loss, infections, or cancer. Multivariate analysis highlighted "in-target" TTV DNAemia as the sole independent variable significantly linked to decreased risk for long-term complications due to inadequate immunosuppression (odds ratio [OR]: 0.27 [0.09-0.77]; p = 0.019). Our data suggest that the longitudinal monitoring of TTV DNAemia in kidney transplant recipients could help preventing the long-term complications due to inadequate immunosuppression., (© 2024 Wiley Periodicals LLC.)
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- 2024
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18. Nornidulin, A New Inhibitor of Plasmodium falciparum Malate: Quinone Oxidoreductase ( Pf MQO) from Indonesian Aspergillus sp. BioMCC f.T.8501.
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Cahyono AW, Fitri LE, Winarsih S, Prabandari EE, Waluyo D, Pramisandi A, Chrisnayanti E, Dewi D, Siska E, Nurlaila N, Nugroho NB, Nozaki T, and Suciati S
- Abstract
This study aimed to obtain a microbial active compound as a novel antimalarial drug from Indonesian isolates. Target-based assays were used to screen for antimalarial activity against the parasite mitochondrial, Plasmodium falciparum malate:quinone oxidoreductase ( Pf MQO) enzyme. In total, 1600 crude extracts, composed from 800 fungi and 800 actinomycetes extracts, were screened against Pf MQO, yielding six active extracts as primary hits. After several stages of stability tests, one extract produced by Aspergillus sp. BioMCC f.T.8501 demonstrated stable Pf MQO inhibitory activity. Several purification stages, including OCC, TLC, and HPLC, were performed to obtain bioactive compounds from this active extract. All purification steps were followed by an assay against Pf MQO. We identified the active compound as nornidulin based on its LC-MS and UV spectrum data. Nornidulin inhibited Pf MQO activity at IC
50 of 51 µM and P. falciparum 3D7 proliferation in vitro at IC50 of 44.6 µM, however, it had no effect on the growth of several mammalian cells. In conclusion, we isolated nornidulin from Indonesian Aspergillus sp. BioMCC f.T.8501 as a novel inhibitor of Pf MQO, which showed inhibitory activity against the proliferation of P. falciparum 3D7 in vitro.- Published
- 2023
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19. CO 2 laser heating system for in situ radial x-ray absorption at 16-BM-D at the Advanced Photon Source.
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Childs C, Smith D, Smith GA, Ellison P, Sneed D, Hinton J, Siska E, Pigott JS, Rod E, O'Donnell W, Salem R, Sturtevant B, Scharff RJ, Velisavljevic N, Park C, and Salamat A
- Abstract
We present a portable CO
2 laser heating system for in situ x-ray absorption spectroscopy (XAS) studies at 16-BM-D (High Pressure Collaborative Access Team, Advanced Photon Source, Argonne National Laboratory). Back scattering optical measurements are made possible by the implementation of a Ge beamsplitter. Optical pyrometry is conducted in the near-infrared, and our temperature measurements are free of chromatic aberration due to the implementation of the peak-scaling method [A. Kavner and W. R. Panero, Phys. Earth Planet. Inter. 143-144, 527-539 (2004) and A. Kavner and C. Nugent, Rev. Sci. Instrum. 79, 024902 (2008)] and mode scrambling of the input signal. Laser power stabilization is established using electronic feedback, providing a steady power over second timescales [Childs et al., Rev. Sci. Instrum. 91, 103003 (2020)]-crucial for longer XAS collections. Examples of in situ high pressure-temperature extended x-ray absorption fine structure measurements of ZrO2 are presented to demonstrate this new capability.- Published
- 2022
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20. Pressure-induced metallization and 3d-like behavior in TcS 2 .
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Sayre D, Siska E, Smith GA, Chang N, Park C, Poineau F, Schwartz CP, Lawler KV, and Salamat A
- Abstract
TcS
2 undergoes a charge transfer insulator to metal transition above 28 GPa. Laser annealing reveals a kinetically hindered high pressure arsenopyrite phase that is recoverable to ambient. The new phase is similar to the Mn-dichalcogenides rather than the expected Re-dichalcogenides and involves the formation of S-S and Tc-Tc bonds.- Published
- 2022
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21. Exploring natural microbial resources for the discovery of anti-malarial compounds.
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Waluyo D, Prabandari EE, Pramisandi A, Hidayati DN, Chrisnayanti E, Puspitasari DJ, Dewi D, Suryani, Kristiningrum, Oktaviani AN, Afrianti KR, Nonaka K, Matsumoto A, Tokiwa T, Adipratiwi N, Ariyani T, Hartuti ED, Putri TZ, Rahmawati Y, Inaoka DK, Miyazaki Y, Sakura T, Nurlaila, Siska E, Kurnia K, Bernawati P, Melinda, Mahsunah AH, Nugroho NB, Mori M, Dobashi K, Yamashita M, Nurkanto A, Watanabe A, Shiomi K, Wibowo AE, and Nozaki T
- Subjects
- Indonesia, Antimalarials isolation & purification, Antimalarials pharmacology, Drug Discovery, Plasmodium falciparum drug effects
- Abstract
Microorganisms in nature are highly diverse biological resources, which can be explored for drug discovery. Some countries including Brazil, Columbia, Indonesia, China, and Mexico, which are blessed with geographical uniqueness with diverse climates and display remarkable megabiodiversity, potentially provide microorganismal resources for such exploitation. In this review, as an example of drug discovery campaigns against tropical parasitic diseases utilizing microorganisms from such a megabiodiversity country, we summarize our past and on-going activities toward discovery of new antimalarials. The program was held in a bilateral collaboration between multiple Indonesian and Japanese research groups. In order to develop a new platform of drug discovery utilizing Indonesian bioresources under an international collaborative scheme, we aimed at: 1) establishment of an Indonesian microbial depository, 2) development of robust enzyme-based and cell-based screening systems, and 3) technology transfer necessary for screening, purification, and identification of antimalarial compounds from microbial culture broths. We collected, characterized, and deposited Indonesian microbes. We morphologically and genetically characterized fungi and actinomycetes strains isolated from 5 different locations representing 3 Indonesian geographical areas, and validated genetic diversity of microbes. Enzyme-based screening was developed against two validated mitochondrial enzymes from Plasmodium falciparum, dihydroorotate dehydrogenase and malate:quinone oxidoreductase, while cell-based proliferation assay was developed using the erythrocytic stage parasite of 3D7 strain. More than 17 thousands microbial culture extracts were subjected to the enzyme- and cell-based screening. Representative anti-malarial compounds discovered in this campaign are discussed, including a few isolated compounds that have been identified for the first time as anti-malarial compounds. Our antimalarial discovery campaign validated the Indonesian microbial library as a powerful resource for drug discovery. We also discuss critical needs for selection criteria for hits at each stage of screening and hit deconvolution such as preliminary extraction test for the initial profiling of the active compounds and dereplication techniques to minimize repetitive discovery of known compounds., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
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22. Synthesis and chemical stability of technetium nitrides.
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Siska E, Smith D, Salamat A, Lawler KV, Lavina B, Poineau F, and Forster PM
- Abstract
We demonstrate the synthesis and phase stability of TcN, Tc
2 N, and a substoichiometric TcNx from 0 to 50 GPa and to 2500 K in a laser-heated diamond anvil cell. At least potential recoverability is demonstrated for each compound. TcN adopts a previously unpredicted structure identified via crystal structure prediction.- Published
- 2021
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23. Phosphorus Dimerization in Gallium Phosphide at High Pressure.
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Lavina B, Kim E, Cynn H, Weck PF, Seaborg K, Siska E, Meng Y, and Evans W
- Abstract
Using combined experimental and computational approaches, we show that at 43 GPa and 1300 K gallium phosphide adopts the super- Cmcm structure, here indicated with its Pearson notation oS24. First-principles enthalpy calculations demonstrate that this structure is more thermodynamically stable above ∼20 GPa than previously proposed polymorphs. In contrast to other polymorphs, the oS24 phase shows a strong bonding differentiation and distorted fivefold coordination geometries of both P atoms. The shortest bond of the phase is a single covalent P-P bond measuring 2.171(11) Å at synthesis pressure. Phosphorus dimerization in GaP sheds light on the nature of the super- Cmcm phase and provides critical new insights into the high-pressure polymorphism of octet semiconductors. Bond directionality and anisotropy explain the relatively low symmetry of this high-pressure phase.
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- 2018
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24. Iodine-lithium-alpha-dextrin (ILαD) against Staphylococcus aureus skin infections: a comparative study of in-vitro bactericidal activity and cytotoxicity between ILαD and povidone-iodine.
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Zisi AP, Exindari MK, Siska EK, and Koliakos GG
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- Anti-Infective Agents, Local toxicity, Cell Line, Cell Survival drug effects, Colony Count, Microbial, Dextrins toxicity, Humans, Lithium toxicity, Microbial Sensitivity Tests, Microbial Viability drug effects, Povidone-Iodine toxicity, Staphylococcus aureus isolation & purification, Staphylococcus aureus physiology, Anti-Infective Agents, Local pharmacology, Dextrins pharmacology, Lithium pharmacology, Povidone-Iodine pharmacology, Staphylococcal Skin Infections microbiology, Staphylococcus aureus drug effects
- Abstract
Background: As antimicrobial resistance continues to increase, revisiting old antimicrobial agents, modified to enhance efficacy and safety, becomes important. Iodine has been widely used for more than 150 years as a wound and skin disinfectant; it is an effective broad range bactericide and does not promote the development of resistant strains. The most important iodine-based agent is povidone-iodine (PVP-I) which provides excellent antibacterial activity. However, its safety profile has been questioned., Aim: To evaluate the in-vitro antibacterial efficacy and kinetic properties of a novel iodine-based compound, iodine lithium alpha-dextrin (ILαD), against Staphylococcus aureus, and compare the in-vitro cytotoxicity profiles of ILαD and PVP-I., Methods: A minimum inhibitory concentration (MIC) microbroth dilution method was performed against 12 meticillin-resistant (MRSA) and eight meticillin-susceptible (MSSA) S. aureus clinical isolates using ILαD and PVP-I. Time-kill and post-antibiotic effect studies of ILαD provided rate-of-kill information. MTT cytotoxicity assays were performed using three cell lines, treated with MIC doses of ILαD and PVP-I., Findings: The MIC values of ILαD and PVP-I against the MRSA strains were 125 mg/L and 31.25 mg/L, respectively. Time-kill and post-antibiotic effect studies of ILαD revealed a log10 reduction factor of 3 within 8 h of exposure at a 2 × MIC dose; the post-antibiotic effect was calculated at 5±0.3h. Cell viability was affected slightly at the MIC dose of ILαD, while the MIC dose of PVP-I exerted a strong cell growth inhibitory effect of 90-95%., Conclusions: ILαD could be a promising solution against staphylococcal infections as it is effective, does not promote the development of resistant strains, and in-vitro testing indicates that it may be safer than PVP-I. Further studies are justified to determine whether ILαD overcomes the clinical limitations of PVP-I., (Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2018
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25. A Time Course of Bevacizumab (Anti-VEGF) Effect on Rat Peritoneum: Relations Between Antiadhesive Action and Fibrin Regulation Enzymes.
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Micha AE, Psarras K, Ouroumidis O, Siska E, Vlachaki E, Lymperopoulos A, Symeonidis N, Nikolaidou C, Venizelos I, Koliakos G, and Pavlidis TE
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- Animals, Cecum pathology, Male, Matrix Metalloproteinase 9 metabolism, Peritoneum pathology, Plasminogen Activator Inhibitor 1 metabolism, Rats, Rats, Wistar, Tissue Plasminogen Activator metabolism, Angiogenesis Inhibitors pharmacology, Bevacizumab pharmacology, Cecum drug effects, Fibrinolysis drug effects, Peritoneum drug effects, Tissue Adhesions prevention & control
- Abstract
Background: To investigate the early and late antiadhesive effect and any changes of fibrin matrix regulation enzymes on rat peritoneum, after local administration of bevacizumab., Methods: Rats were subjected to cecal abrasion. Bevacizumab (5 mg/kg) against placebo was given intraperitoneally. On the 2nd, 14th, and 28th postoperative days adhesions were scored, and tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-9 (MMP-9), degree of fibrosis, and angiogenesis were measured in abrased cecum and in intact parietal peritoneum., Results: Bevacizumab significantly reduced adhesions up to 15% on the 2nd, 52.5% on the 14th, and 55% on the 28th postoperative day, and significantly increased tPA concentrations in peritoneum. PAI-1 was decreased, and a significantly higher tPA/PAI-1 ratio along with an increase of MMP-9 was measured at all time points. Fibrosis and angiogenesis were significantly lower on the 14th and 28th postoperative days., Conclusions: Local bevacizumab administration has a strong early and late antiadhesive action on rat peritoneum, mediated by changes in the tPA/PAI-1 and MMP balance in favor of fibrinolysis up to 28 days after operations.
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- 2017
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26. Detection and Quantification of Silver Nanoparticles at Environmentally Relevant Concentrations Using Asymmetric Flow Field-Flow Fractionation Online with Single Particle Inductively Coupled Plasma Mass Spectrometry.
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Huynh KA, Siska E, Heithmar E, Tadjiki S, and Pergantis SA
- Abstract
The presence of silver nanoparticles (AgNPs) in aquatic environments could potentially cause adverse impacts on ecosystems and human health. However, current understanding of the environmental fate and transport of AgNPs is still limited because their properties in complex environmental samples cannot be accurately determined. In this study, the feasibility of using asymmetric flow field-flow fractionation (AF4) connected online with single particle inductively coupled plasma mass spectrometry (spICPMS) to detect and quantify AgNPs at environmentally relevant concentrations was investigated. The AF4 channel had a thickness of 350 μm and its accumulation wall was a 10 kDa regenerated cellulose membrane. A 0.02% FL-70 surfactant solution was used as an AF4 carrier. With 1.2 mL/min AF4 cross-flow rate, 1.5 mL/min AF4 channel flow rate, and 5 ms spICPMS dwell time, the AF4-spICPMS can detect and quantify 40-80 nm AgNPs, as well as Ag-SiO2 core-shell nanoparticles (51.0 nm diameter Ag core and 21.6 nm SiO2 shell), with good recovery within 30 min. This system was not only effective in differentiating and quantifying different types of AgNPs with similar hydrodynamic diameters, such as in mixtures containing Ag-SiO2 core-shell nanoparticles and 40-80 nm AgNPs, but also suitable for differentiating between 40 nm AgNPs and elevated Ag(+) content. The study results indicate that AF4-spICPMS is capable of detecting and quantifying AgNPs and other engineered metal nanomaterials in environmental samples. Nevertheless, further studies are needed before AF4-spICPMS can become a routine analytical technique.
- Published
- 2016
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27. Separation and measurement of silver nanoparticles and silver ions using magnetic particles.
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Mwilu SK, Siska E, Baig RB, Varma RS, Heithmar E, and Rogers KR
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- Magnetic Phenomena, Metal Nanoparticles analysis, Particle Size, Silver analysis, Metal Nanoparticles chemistry, Models, Chemical, Silver chemistry
- Abstract
The recent surge in consumer products and applications using metallic nanoparticles has increased the possibility of human or ecosystem exposure due to unintentional release into the environment. To protect consumer health and the environment, there is an urgent need to develop tools that can characterize and quantify these materials at low concentrations and in complex matrices. In this study, magnetic nanoparticles coated with either dopamine or glutathione were used to develop a new, simple and reliable method for the separation/pre-concentration of trace amounts of silver nanoparticles followed by their quantification using inductively coupled plasma mass spectrometry (ICP-MS). The structurally modified magnetic particles were able to capture trace amounts of silver nanoparticles (~2 ppb) and concentrate (up to 250 times) the particles for analysis with ICP-MS. Under laboratory conditions, recovery of silver nanoparticles was >99%. More importantly, the magnetic particles selectively captured silver nanoparticles in a mixture containing both nano-particulate and ionic silver. This unique feature addresses the challenges of separation and quantification of silver nanoparticles in addition to the total silver in environmental samples. Spiking experiments showed recoveries higher than 97% for tap water and both fresh and saline surface water., (© 2013. Published by Elsevier B.V. All rights reserved.)
- Published
- 2014
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28. [Congenital cataracts facial dysmorphism neuropathy syndrome--first Hungarian case report].
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Siska E, Neuwirth M, Rebecca G, and Molnár MJ
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- Adolescent, Brain diagnostic imaging, Brain pathology, Child, Child, Preschool, Developmental Disabilities physiopathology, Female, Humans, Hungary, Infant, Magnetic Resonance Imaging, Pedigree, Polymerase Chain Reaction, Protein Phosphatase 1, Psychomotor Performance, Syndrome, Tomography, X-Ray Computed, Walking, Cataract congenital, Developmental Disabilities genetics, Facial Nerve Diseases congenital, Mutation, Nuclear Proteins genetics, Phosphoprotein Phosphatases genetics, Roma genetics
- Abstract
The congenital cataracts facial dysmorphism neuropathy (CCFDN) syndrome (OMIM 604168) is a recently described autosomal recessive developmental disorder. It is almost completely restricted to an endogamous group of the European Vlax Roma population, called the Rudari. The CCFDN syndrome is a complex phenotype involving multiple systems, characterized by facial dysmorphism, congenital cataracts, microcorneae, delayed early motor and intellectual development, hypogonadotrop hypogonadism, hypomyelination of the peripheral nervous system, and serious complications related to general anaesthesia. This disorder is caused by a homozygous mutation of the carboxy-terminal domain phosphatase 1 (CTDP1) gene, localized to the 18q23 region. Authors present one genetically identified case in a large Roma family. The case documents that the CCFDN mutation is present also in the Hungarian Roma population. Underlie of antropomorphological data the authors presume that the CCFDN mutation reached Hungary as a result of emigration of Vlax Gypsies in the 18th century. The paper calls attention to the fact that molecular genetic diagnostics can replace invasive methods and makes possible the identification of heterozygotes without clinical symptoms. The introduction of the genetic screening enables us to perform genetic counselling and prevention in this high-risk population.
- Published
- 2007
29. [Hereditary motor and sensory Lom-neuropathy--first Hungarian case report].
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Szabó A, Siska E, and Molnár MJ
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- Adolescent, Adult, Child, Chromosomes, Human, Pair 8, Female, Hereditary Sensory and Motor Neuropathy genetics, Hereditary Sensory and Motor Neuropathy physiopathology, Homozygote, Humans, Hungary, Male, Phenotype, Roma, Cell Cycle Proteins genetics, Hereditary Sensory and Motor Neuropathy diagnosis, Intracellular Signaling Peptides and Proteins genetics, Mutation, Missense
- Abstract
Hereditary motor and sensory neuropathy-Lom is an autosomal recessive disorder of the peripheral nervous system, which occurs only in the european Roma population. The symptoms start in the first decade with slowly progressive gait disturbance, weakness and wasting of distal upper extremity muscles, joint deformities and hearing loss develop later in the second and third decades. This disorder is caused by a homozygous missense mutation of the NDRG1 gene, located in the 8q24 region. The Schwann cell dysfunction is most probably caused by altered lipid metabolism as a consequence of the NDRG1 mutation. Molecular genetic testing can be a first diagnostic step among roma individuals showing a Lom neuropathy phenotype, making evaluation of such patients and also genetic counselling faster and easier. Screening for hereditary neuromuscular disorders in this genetically isolated community may become an important public health issue in the near future.
- Published
- 2007
30. [Acute quadriplegia after diabetic ketoacidosis].
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Mihalik Z, Arányi Z, Siska E, Nyulasi T, and Pénzes I
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- Acute Disease, Adult, Anti-Inflammatory Agents adverse effects, Critical Illness, Diabetes Mellitus, Type 1 drug therapy, Diabetic Ketoacidosis etiology, Electric Stimulation Therapy, Electromyography, Female, Gastroenteritis complications, Glucocorticoids adverse effects, Humans, Muscular Atrophy etiology, Pneumonia complications, Polyneuropathies etiology, Quadriplegia therapy, Time Factors, Treatment Outcome, Diabetes Mellitus, Type 1 complications, Diabetic Ketoacidosis complications, Quadriplegia etiology
- Abstract
A 36-year-old female was admitted to the intensive care unit after resuscitation diagnosed with diabetic ketoacidotic coma, which was the first manifestation of her diabetes mellitus. It may have been provoked by pulmonary or gastrointestinal coinfection. Five days following admission the patient regained consciousness and homeostasis returned to normal. One week after the stabilization of her cardiopulmonary state, weaning from the respirator turned out to be unsuccessful: flaccid tetraparesis developed with rapid muscle atrophy and absence of deep tendon reflexes. The sensory system and cranial nerves remained intact. Electrophysiological studies and muscle biopsy showed serious acute illness myopathy with mild demyelination owing probably to the latent diabetes. The course of acute quadriplegia was fluctuating and correlated mainly with the activity of the systemic inflammatory response syndrome mechanisms. Myopathy might have been aggravated by using high-dose glucocorticoid therapy. The patient's general condition improved quickly as a result of full recovery from sepsis, discontinuation of glucocorticoids and normoglicaemia maintained by subcutan insulin substitution. Eight months after admission almost full neuromuscular restitution was achieved showing the reversibility of this grave illness.
- Published
- 2003
31. Limitations of Folin assays of foliar phenolics in ecological studies.
- Author
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Appel HM, Govenor HL, D'Ascenzo M, Siska E, and Schultz JC
- Subjects
- Biological Assay methods, Ecology, Indicators and Reagents, Oxidation-Reduction, Phenols analysis, Plants chemistry, Tannins analysis
- Abstract
We examined the response of the widely used Folin-Denis assay to purified tannins from 16 woody plant species and to three commercial polyphenol preparations often used as standards. The reagent's response to these chemical mixtures differed significantly among sources (tree species, commercial preparations) and sampling dates, even though the mixtures contained the same total dry weight of tannins. Response to commercial standards usually did not resemble response to actual plant tannin and produced estimates that differed from actual concentrations by as much as twofold. Species-based and seasonal differences in polyphenol composition are evidently responsible for these variable results. Reagents that depend on redox reactions, such as the Folin-Denis, do not produce reliable absolute or relative quantification of phenolics when different species or samples from different dates are compared, and use of commercial standards does not resolve this problem.
- Published
- 2001
- Full Text
- View/download PDF
32. SIDS: counseling parents to reduce the risk.
- Author
-
Carroll JL and Siska ES
- Subjects
- Breast Feeding, Environmental Exposure adverse effects, Female, Humans, Infant, Newborn, Monitoring, Physiologic, Pregnancy, Risk Factors, Sleep, Supine Position, Tobacco Smoke Pollution adverse effects, Counseling methods, Parents, Sudden Infant Death prevention & control
- Abstract
Although the cause or causes of sudden infant death syndrome (SIDS) remain unknown, the incidence of SIDS is on the decline in the United States and other countries. This decline has been accomplished largely through public education campaigns informing parents about several important factors associated with an increased risk of SIDS. These factors are prone and side infant sleeping positions, exposure of infants to cigarette smoke and potentially hazardous sleeping environments. Risk-reduction measures such as placing healthy infants to sleep in the supine position, avoiding passive smoke exposure both before and after birth and optimizing crib safety are beginning to lower the SIDS rate in this country. Through patient education, family physicians can further reduce the incidence of the number one cause of death in infants one week to one year old.
- Published
- 1998
33. [Thalamic dementia].
- Author
-
Siska E, Geréby G, and Tariska S
- Subjects
- Adult, Alpha Rhythm, Arousal physiology, Atrophy, Brain Stem pathology, Cerebellum pathology, Cerebral Cortex physiopathology, Dementia physiopathology, Electroencephalography, Female, Humans, Nerve Degeneration, Thalamic Diseases physiopathology, Thalamus physiopathology, Theta Rhythm, Dementia pathology, Thalamic Diseases pathology
- Abstract
Report with complementary clinical examinations and detailed neuropathological findings of a case of subacute progressing "thalamic dementia", interpreted as combined systemic degeneration of the dorsal and medial thalamic nuclei. For the development of the EEG changes, which were followed from beginning of the disease, a slowly advancing reduction of the function of the meso-diencephalic activating system proved responsible. The inferior olives were symmetrically atrophied and the fasciculus tegmenti centralis was on both sides completely degenerated. It is to be considered that the inferior olives are directly subordinated to the medial thalamic nuclei by the way of the fasciculus tegmenti centralis. In the cerebellum nerve cell groups and fiber bundles, which are closely connected with the reticular system, are degenerated. The systemic medial degenerations of the thalamus belong to the abiotrophies in the sense of Gowers original conception.
- Published
- 1985
- Full Text
- View/download PDF
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