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Sample records for vitro plasma inactivation

  1. Bacterial inactivation/sterilization by argon plasma treatment on contaminated titanium implant surfaces:In vitro study

    Science.gov (United States)

    Annunziata, Marco; Donnarumma, Giovanna; Caputo, Pina; Nastri, Livia; Guida, Luigi

    2016-01-01

    Background Surface treatment by argon plasma is widely used as the last step of the manufacturing process of titanium implant fixtures before their sterilization by gamma rays. The possibility of using such a technology in the daily clinical practice is particularly fascinating. The aim of the present study was to assess the effects of the argon plasma treatment on different titanium implant surfaces previously exposed In vitro to bacterial contamination. Material and Methods Sterile c.p. titanium implant discs with turned (T, Sa: 0.8 µm ), sandblasted/acid-etched (SAE, Sa: 1.3 µm) and titanium plasma sprayed (TPS, Sa: 3.0µm) surface were used in this study. A strain of Aggregatibacter actinomycetemcomitans ATCC3718 was grown at 37°C under anaerobic conditions for 24 h and then transferred on six discs for each of the three surface types. After 24 hours, a half of the contaminated discs (control group) were directly used to evaluate the colony forming units (CFUs). The other half of the contaminated discs (test group) were treated in an argon plasma chamber for 12 minutes at room temperature prior to be analyzed for CFU counting. All assays were performed using triplicate samples of each material in 3 different experiments. Results When the CFU counting was carried out on control discs, a total of 1.50x106±1.4x105, 1.55x106±7.07x104 and 3.15x106±2.12x105 CFU was respectively assessed for T, SAE and TPS discs, without statistically significant differences among the three surfaces. On the contrary, any trace of bacterial contamination was assessed for titanium discs treated in the argon plasma chamber prior to be analyzed, irrespectively to the implant surface tested. Conclusions Within the limit of this study, reported data suggested that the argon plasma technology could be efficiently used to decontaminate/sterilize previously infected titanium implant surfaces. Key words:Argon plasma, titanium implant surface, Aggregatibacter actinomycetemcomitans. PMID

  2. Hyaluronan decreases surfactant inactivation in vitro.

    Science.gov (United States)

    Lu, Karen W; Goerke, Jon; Clements, John A; Taeusch, H William

    2005-02-01

    Hyaluronan (HA) is an anionic polymer and a constituent of alveolar fluid that can bind proteins, phospholipids, and water. Previous studies have established that nonionic polymers improve the surface activity of pulmonary surfactants by decreasing inactivation of surfactant. In this work, we investigate whether HA can also have beneficial effects when added to surfactants. We used a modified pulsating bubble surfactometer to measure mixtures of several commercially available pulmonary surfactants or native calf surfactant with and without serum inactivation. Surface properties such as equilibrium surface tension, minimum and maximum surface tensions on compression and expansion of a surface film, and degree of surface area reduction required to reach a surface tension of 10 mN/m were measured. In the presence of serum, addition of HA dramatically improved the surface activities of all four surfactants and in some cases in the absence of serum as well. These results indicate that HA reduces inactivation of surfactants caused by serum and add evidence that endogenous HAs may interact with alveolar surfactant under normal and abnormal conditions.

  3. Inactivation of virus in solution by cold atmospheric pressure plasma: identification of chemical inactivation pathways

    Science.gov (United States)

    Aboubakr, Hamada A.; Gangal, Urvashi; Youssef, Mohammed M.; Goyal, Sagar M.; Bruggeman, Peter J.

    2016-05-01

    Cold atmospheric pressure plasma (CAP) inactivates bacteria and virus through in situ production of reactive oxygen and nitrogen species (RONS). While the bactericidal and virucidal efficiency of plasmas is well established, there is limited knowledge about the chemistry leading to the pathogen inactivation. This article describes a chemical analysis of the CAP reactive chemistry involved in the inactivation of feline calicivirus. We used a remote radio frequency CAP produced in varying gas mixtures leading to different plasma-induced chemistries. A study of the effects of selected scavengers complemented with positive control measurements of relevant RONS reveal two distinctive pathways based on singlet oxygen and peroxynitrous acid. The first mechanism is favored in the presence of oxygen and the second in the presence of air when a significant pH reduction is induced in the solution by the plasma. Additionally, smaller effects of the H2O2, O3 and \\text{NO}2- produced were also found. Identification of singlet oxygen-mediated 2-imidazolone/2-oxo-His (His  +14 Da)—an oxidative modification of His 262 comprising the capsid protein of feline calicivirus links the plasma induced singlet oxygen chemistry to viral inactivation.

  4. Degradation and inactivation of Shiga toxins by nitrogen gas plasma.

    Science.gov (United States)

    Sakudo, Akikazu; Imanishi, Yuichiro

    2017-12-01

    Shiga toxin (Stx)-producing Escherichia coli (STEC) leads to food poisoning by causing hemorrhagic colitis and hemolytic uremic syndrome. Some STEC produce Shiga toxin 1 (Stx1) and/or Shiga toxin 2 (Stx2), a relatively stable protein toxin, necessitating the development of an efficient inactivation method. Here we applied a nitrogen gas plasma apparatus to the inactivation of Stx. Samples of Stx1 and Stx2 were treated with a nitrogen gas plasma generated by a plasma device using a short high-voltage pulse applied by a static induction thyristor power supply at 1.5 kpps (kilo pulse per second). The recovered Stx samples were then analyzed for immunological and biological activities. Immunochromatography demonstrated that Stx1 and Stx2 were degraded by the gas plasma. Quantification by enzyme-linked immunosorbent assay (ELISA) showed that both toxins were efficiently degraded to less than 1/10th of their original concentration within 5 min of treatment. Western blotting further showed the gas plasma treatment degraded the A subunit, which mediates the toxicity of Stx. Moreover, an assay using HEp-2 cells as an index of cytotoxicity showed that gas plasma treatment reduced the toxic activity of Stx. Therefore, nitrogen gas plasma might be an efficient method for the inactivation of Stx.

  5. Non-thermal plasma for inactivated-vaccine preparation.

    Science.gov (United States)

    Wang, Guomin; Zhu, Ruihao; Yang, Licong; Wang, Kaile; Zhang, Qian; Su, Xia; Yang, Bing; Zhang, Jue; Fang, Jing

    2016-02-17

    Vaccines are of great importance in controlling the spread of infectious diseases in poultry farming. The safety and efficacy of vaccines are also essential. To explore the feasibility of a novel technology (non-thermal plasma) in inactivated vaccine preparation, an alternating current atmospheric pressure non-thermal plasma (NTP) jet with Ar/O2/N2 as the operating gas was used to inactivate a Newcastle disease virus (NDV, LaSota) strain and H9N2 avian influenza virus (AIV, A/Chicken/Hebei/WD/98) for vaccine preparation. The results showed that complete inactivation could be achieved with 2 min of NTP treatment for both NDV and AIV. Moreover, a proper NTP treatment time is needed for inactivation of a virus without destruction of the antigenic determinants. Compared to traditional formaldehyde-inactivated vaccine, the vaccine made from NDV treated by NTP for 2 min (NTP-2 min-NDV-vaccine) could induce a higher NDV-specific antibody titer in specific pathogen-free (SPF) chickens, and the results of a chicken challenge experiment showed that NTP-2 min-NDV-vaccine could protect SPF chickens from a lethal NDV challenge. Vaccines made from AIV treated by NTP for 2 min (NTP-2 min-AIV-vaccine) also showed a similar AIV-specific antibody titer compared with traditional AIV vaccines prepared using formaldehyde inactivation. Studies of the morphological changes of the virus, chemical analysis of NDV allantoic fluid and optical emission spectrum analysis of NTP suggested that reactive oxygen species and reactive nitrogen species produced by NTP played an important role in the virus inactivation process. All of these results demonstrated that it could be feasible to use non-thermal NTP as an alternative strategy to prepare inactivated vaccines for Newcastle disease and avian influenza. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Nonthermal Plasma Inactivation of Food-Borne Pathogens

    OpenAIRE

    Misra, N.; Tiwari, B.; Rahavarao, K.; Cullen, Patrick

    2011-01-01

    Non-thermal plasma (NTP) is electrically energized matter, composed of highly reactive species including gas molecules, charged particles in the form of positive ions, negative ions, free radicals, electrons and quanta of electromagnetic radiation (photons) at near-room temperature. NTP is an emerging nonthermal technology with potential applications for decontamination in the food industries. An upsurge in the research activities for plasma based inactivation of food borne pathogens is evide...

  7. Virus-inactivated plasma - Plasmasafe: a one-year experience

    Science.gov (United States)

    De Silvestro, Giustina; Bagatella, Paola; Tison, Tiziana; Quaino, Vania; Carraro, Paolo; Tenderini, Maria Luisa; Lazzaro, Annarosa; Marotti, Alberto

    2007-01-01

    Background Fresh-frozen plasma (FFP) is a widely used blood transfusion product. The transfusion safety of this product is ensured by legally obligatory tests, but can be further improved by using some technical procedures, such as methylene blue (MB) and solvent-detergent (SD) viral inactivation methods. Mainly organisational criteria led us to introduce the SD viral inactivation technique as a service activity. In this report we describe our first year of experience, following the introduction of the SD technique, and thus the use of SD-virally inactivated plasma (PlasmaSafe). Materials and methods In order to evaluate the appropriate use and the therapeutic efficacy of PlasmaSafe in our Blood Transfusion Unit, the following programme was planned: quality control [prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen] of the FFP units (N=312); evaluation of the clinical effectiveness on 490 patients (879 transfusion events); pre- and post-treatment monitoring of indicators of coagulation (PT, aPTT, fibrinogen, proteins S and C, factor VIII) on 15 patients; treatment of three patients with thrombotic thrombocytopenic purpura (TTP) undergoing plasma-exchange; haemovigilance of adverse reactions provoked by SD-plasma. Results The indicators of coagulation in the FFP units varied greatly: the PT ranged from 50–120%, the aPTT from 24–41 seconds and the fibrinogen concentration from 1.42–6.84 g/L. Seventy-six percent of the patients responded to the plasma administration; moreover, two of 15 patients in whom protein S was assayed, showed no increase of this haemostatic protein. The TTP patients responded to plasma exchange treatment following four sessions of apheresis. During the observation period 8,422 PlasmaSafe units were transfused and no adverse reactions were recorded. Conclusion PlasmaSafe, a pharmaceutical-like product with a standardised content of coagulation factors, was found to be effective at correcting coagulation

  8. Inactivation of animal and human prions by hydrogen peroxide gas plasma sterilization.

    Science.gov (United States)

    Rogez-Kreuz, C; Yousfi, R; Soufflet, C; Quadrio, I; Yan, Z-X; Huyot, V; Aubenque, C; Destrez, P; Roth, K; Roberts, C; Favero, M; Clayette, P

    2009-08-01

    Prions cause various transmissible spongiform encephalopathies. They are highly resistant to the chemical and physical decontamination and sterilization procedures routinely used in healthcare facilities. The decontamination procedures recommended for the inactivation of prions are often incompatible with the materials used in medical devices. In this study, we evaluated the use of low-temperature hydrogen peroxide gas plasma sterilization systems and other instrument-processing procedures for inactivating human and animal prions. We provide new data concerning the efficacy of hydrogen peroxide against prions from in vitro or in vivo tests, focusing on the following: the efficiency of hydrogen peroxide sterilization and possible interactions with enzymatic or alkaline detergents, differences in the efficiency of this treatment against different prion strains, and the influence of contaminating lipids. We found that gaseous hydrogen peroxide decreased the infectivity of prions and/or the level of the protease-resistant form of the prion protein on different surface materials. However, the efficiency of this treatment depended strongly on the concentration of hydrogen peroxide and the delivery system used in medical devices, because these effects were more pronounced for the new generation of Sterrad technology. The Sterrad NX sterilizer is 100% efficient (0% transmission and no protease-resistant form of the prion protein signal detected on the surface of the material for the mouse-adapted bovine spongiform encephalopathy 6PB1 strain and a variant Creutzfeldt-Jakob disease strain). Thus, gaseous or vaporized hydrogen peroxide efficiently inactivates prions on the surfaces of medical devices.

  9. Kinetics of Tomato Peroxidase Inactivation by Atmospheric Pressure Cold Plasma Based on Dielectric Barrier Discharge

    OpenAIRE

    Cullen, Patrick; Pankaj, Shashi; Misra, N

    2013-01-01

    Atmospheric pressure cold plasma technology is an emerging nonthermal food technology for microbiological decontamination of food and bio-materials. This study demonstrates the applicability of in-package cold plasma technology as a novel means to inactivation of enzymes. The kinetics of inactivation of tomato peroxidase as a model enzyme was studied at 30, 40 and 50kV, for up to 5’ of atmospheric air dielectric barrier discharge plasma treatments. The enzyme activity was found to decrease wi...

  10. Blue light-mediated inactivation of Enterococcus faecalis in vitro.

    Science.gov (United States)

    Pileggi, Giorgio; Wataha, John C; Girard, Myriam; Grad, Iwona; Schrenzel, Jacques; Lange, Norbert; Bouillaguet, Serge

    2013-05-01

    In dentistry, residual infection remains a major cause of failure after endodontic treatment; many of these infections involve Enterococcus faecalis. In the current study, we explored the possibility that blue light activated photosensitizers could be used, in principle, to inactivate this microbe as an adjunct disinfection strategy for endodontic therapy. Three blue light absorbing photosensitizers, eosin-Y, rose bengal, and curcumin, were tested on E. faecalis grown in planktonic suspensions or biofilms. Photosensitizers were incubated for 30 min with bacteria then exposed to blue light (450-500 nm) for 240 s. Sodium hypochlorite (3%) was used as a control. After 48 h, the viability of E. faecalis was estimated by measuring colony-forming units post-exposure vs. untreated controls (CFU/mL). Blue light irradiation alone did not alter E. faecalis viability. For planktonic cultures, blue light activated eosin-Y (5 μM), rose bengal (1 μM), or curcumin (5 μM) significantly (pfaecalis viability compared to exposure to the unirradiated photochemicals. For biofilm cultures, concentrations of light-activated eosin-Y, rose bengal, and curcumin of 100, 10, and 10 μM respectively, completely suppressed E. faecalis viability (p<0.05). Although the current results are limited to an in vitro model, they support further exploration of blue light activated antimicrobials as an adjunct therapy in endodontic treatment. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Rapid inactivation of Penicillium digitatum spores using high-density nonequilibrium atmospheric pressure plasma

    Science.gov (United States)

    Iseki, Sachiko; Ohta, Takayuki; Aomatsu, Akiyoshi; Ito, Masafumi; Kano, Hiroyuki; Higashijima, Yasuhiro; Hori, Masaru

    2010-04-01

    A promising, environmentally safe method for inactivating fungal spores of Penicillium digitatum, a difficult-to-inactivate food spoilage microorganism, was developed using a high-density nonequilibrium atmospheric pressure plasma (NEAPP). The NEAPP employing Ar gas had a high electron density on the order of 1015 cm-3. The spores were successfully and rapidly inactivated using the NEAPP, with a decimal reduction time in spores (D value) of 1.7 min. The contributions of ozone and UV radiation on the inactivation of the spores were evaluated and concluded to be not dominant, which was fundamentally different from the conventional sterilizations.

  12. Microbial Inactivation in the Liquid Phase Induced by Multigas Plasma Jet.

    Directory of Open Access Journals (Sweden)

    Toshihiro Takamatsu

    Full Text Available Various gas atmospheric nonthermal plasmas were generated using a multigas plasma jet to treat microbial suspensions. Results indicated that carbon dioxide and nitrogen plasma had high sterilization effects. Carbon dioxide plasma, which generated the greatest amount of singlet oxygen than other gas plasmas, killed general bacteria and some fungi. On the other hand, nitrogen plasma, which generated the largest amount of OH radical, killed ≥ 6 log of 11 species of microorganisms, including general bacteria, fungi, acid-fast bacteria, spores, and viruses in 1-15 min. To identify reactive species responsible for bacterial inactivation, antioxidants were added to bacterial suspensions, which revealed that singlet oxygen and OH radicals had greatest inactivation effects.

  13. Inactivation of possible microorganism food contaminants on packaging foils using nonthermal plasma and hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Scholtz, V., E-mail: Vladimir.Scholtz@vscht.cz; Khun, J. [Institute of Chemical Technology in Prague, Department of Physics and Measurements, Faculty of Chemical Engineering (Czech Republic); Soušková, H. [Institute of Chemical Technology in Prague, Department of Computing and Control Engineering, Faculty of Chemical Engineering (Czech Republic); Čeřovský, M. [Institute of Chemical Technology in Prague, Department of Food Preservation, Faculty of Food and Biochemical Technology (Czech Republic)

    2015-07-15

    The inactivation effect of nonthermal plasma generated in electric discharge burning in air atmosphere with water or hydrogen peroxide aerosol for the application to the microbial decontamination of packaging foils is studied. The microbial inactivation is studied on two bacterial, two yeasts, and two filamentous micromycete species. The inactivation of all contaminating microorganisms becomes on the area of full 8.5 cm in diameter circular sample after short times of several tens of seconds. Described apparatus may present a possible alternative method of microbial decontamination of food packaging material or other thermolabile materials.

  14. Effects of heat-inactivated Bifidobacterium BB12 on cariogenicity of Streptococcus mutans in vitro.

    Science.gov (United States)

    Schwendicke, Falk; Horb, Kateryna; Kneist, Susanne; Dörfer, Christof; Paris, Sebastian

    2014-12-01

    Since some probiotic bacteria are cariogenic themselves, their suitability for caries management is questionable. Inactivated bacteria or their supernatants have been found to exert probiotic effects, whilst having several advantages compared with living bacteria. We hypothesized that viable and heat-inactivated Bifidobacterium animalis BB12 reduces the cariogenicity of Streptococcus mutans (SM) in vitro. We assessed mono- and mixed species biofilms of SM and viable or heat-inactivated BB12. Biofilms were grown in a continuous-culture-system under cariogenic conditions on smooth proximal enamel or cavitated dentine. For each of eight experimental subsets (4 biofilms×2 hard-tissue conditions), a total of 32 specimens was used. After 10 days, bacterial numbers of 12 biofilms per group were analysed, and all specimens submitted to transversal microradiography. Mineral loss was higher in cavitated dentine than smooth enamel for all biofilms (p0.05), whilst heat-inactivated BB12 decreased cariogenicity of SM in dentinal cavities (p0.05). Heat-inactivated BB12 reduced the cariogenicity of SM in dentinal cavities in vitro. Inactivated probiotics might be suitable for caries control. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Inactivation of Herpesvirus hominis types 1 and 2 by silver nitrate in vitro and in vivo.

    Science.gov (United States)

    Coleman, V R; Wilkie, J; Levinson, W E; Stevens, T; Jawetz, E

    1973-09-01

    Herpes simplex virus (HSV) types 1 and 2 (two strains each) were inactivated at different rates in vitro by 40 muM AgNO(3). The inactivation of HSV type 1 strains was virtually complete in 10 to 15 min, whereas almost half of the infectivity of HSV type 2 strains survived this exposure. One strain of type 1 inoculated into rabbit eyes was almost completely inactivated by 1% AgNO(3) solution dropped into the eye 20 min later, so that there was markedly reduced viral replication and less corneal herpetic disease. One strain of HSV type 2 in the rabbit eye was not effectively inactivated by 1% AgNO(3). From these results, it seems likely that AgNO(3) instillation into the eyes of a newborn who has passed through a birth canal infected with HSV might prevent eye infection with HSV type 1 but not with type 2. The greater resistance of HSV type 2 strains to chemical inactivation in vitro and in vivo may be of medical concern.

  16. Cold plasma source for bacterial inactivation at atmospheric pressure

    DEFF Research Database (Denmark)

    Chen, Weifeng; Stamate, Eugen; Mejlholm, Ole

    plasma treatment conditions (e.g. power, frequency, time). Preliminary experiments were also performed to evaluate the eect of plasma treatment time on the reduction of the concentration of microorganisms (Lactobacillus sakei and Photobacterium phosphoreum) on inoculated slides of Long & Hammer agar....... The results show that the concentration of Lb. sakei on agar slides was reduced signicantly (P phosphoreum to below the detection limit...

  17. Inactivation of AIDS-causing retroviruses by the manufacturing procedures for human plasma proteins.

    Science.gov (United States)

    Hilfenhaus, J; Gregersen, J P

    1988-04-01

    Human retroviruses causing AIDS (HIV) may occur in human plasma. Since HIV contaminated plasma cannot be completely excluded by testing for anti-HIV, AIDS safety of human plasma products can only be achieved by introducing HIV inactivating and/or eliminating methods into the manufacturing procedure. Here we review a number of methods used when manufacturing plasma derivatives at Behringwerke. These methods were previously developed either to produce a protein of required purity or to manufacture hepatitis safe products. Methods used to produce purer proteins are ethanol fractionation, pepsin treatment, affinity chromatography or various protein precipitation procedures. The method developed at Behringwerke for inactivating infectious viruses in plasma protein preparations not destroying the biological activities of the human protein is pasteurization, i.e. 10 h heat treatment of the aqueous protein solution at 60 degrees C. To investigate the HIV inactivating efficiency of the methods mentioned above, aliquots of an infectious HIV type 1 concentrate were added to a protein preparation, the resulting HIV spiked preparation treated according to the method to be studied and the amount of infectious HIV in this preparation determined before and after treatment. By all methods reported on here the HIV type 1 isolate was completely inactivated resulting in high inactivation factors. In addition, the heat stability of HIV type 2 was tested in aqueous solution at 60 degrees C proving that both HIV-1 and HIV-2 isolates are of comparably low heat stability under these conditions. From the results discussed here it can be concluded that all commercial human protein products of Behringwerke derived from either human plasma or placenta do not contain any infectious retrovirus causing AIDS and thus have a high margin of safety regarding the transmission of AIDS.

  18. Single channel atmospheric pressure transporting plasma and plasma stream demultiplexing: physical characterization and application to E. coli bacteria inactivation

    Science.gov (United States)

    Valinataj Omran, A.; Sohbatzadeh, F.; Siadati, S. N.; Hosseinzadeh Colagar, A.; Akishev, Y.; Arefi-Khonsari, F.

    2017-08-01

    In this article, we developed transporting plasma sources that operate at atmospheric pressure. The effect of electrode configuration on plasma transporting was investigated. In order to increase the transporting plasma cross-section, we converted a plasma stream into four plasma channels by a cylindrical housing. Electron excitation and rotational temperatures were estimated using optical emission spectroscopy. Furthermore, the electrical and temporal characteristics of the plasma, discharge power and charge deposition on the target were investigated. The propagation characteristics of single and multi-channel transporting plasma were compared with the same cross-sectional area. Two configurations for multi-channels were designed for this purpose. Escherichia coli bacteria were exposed to the single and multi-channel transporting discharge for different time durations. After exposure, the results indicated that the inactivation zones were significantly increased by a multi-channel transporting plasma. Finally, E. coli inactivation by those plasma apparatuses was compared with that of several standard antimicrobial test discs such as Gentamicin, Tetracycline, Amoxicillin and Cefixime.

  19. Oral bacterial inactivation using a novel low-temperature atmospheric-pressure plasma device

    Directory of Open Access Journals (Sweden)

    Ya-Ting Chang

    2016-03-01

    Conclusion: The novel low-temperature atmospheric-pressure device was capable of achieving effective sterilization of E. faecalis within a 2-minute interval. Further studies are needed to validate complete inactivation, refine the laboratory-made low-temperature plasma device, and develop a new plasma-jet device, which will be superior to traditional sterilization methods and can be used in root canal environment. This novel sterilization method can also be used as a clinical reference tool.

  20. Antimicrobial and cold plasma treatments for inactivation of listeria monocytogenes on whole apple surface

    Science.gov (United States)

    Introduction: Produce and bacterial cell surface structure play an important role as to where and how bacteria attach to produce surfaces. The efficacy of a novel antimicrobial solution developed in our laboratory was investigated in combination with cold plasma treatments for inactivation of Liste...

  1. Nonthermal inactivation of norovirus surrogates on blueberries using atmospheric cold plasma

    Science.gov (United States)

    Viruses are currently the leading cause of foodborne outbreaks, most of which are associated with foods consumed raw. Cold plasma (CP) is an emerging novel nonthermal technology that can be used to surface decontaminate foods. This study investigated CP technology for the nonthermal inactivation of ...

  2. Inactivation of Escherichia coli on blueberries using cold plasma with chemical augmentation inside a partial vacuum

    Science.gov (United States)

    Justification: The mechanism by which cold plasma inactivates pathogens is through the production of free reactive chemical species. Unfortunately, the most reactive chemical species have the shortest half-life. In a vacuum their half-life is believed to be prolonged. Additionally, these reactive sp...

  3. Potential applications of nonthermal plasmas against biofilm-associated micro-organisms in vitro.

    Science.gov (United States)

    Puligundla, P; Mok, C

    2017-05-01

    Biofilms as complex microbial communities attached to surfaces pose several challenges in different sectors, ranging from food and healthcare to desalination and power generation. The biofilm mode of growth allows microorganisms to survive in hostile environments and biofilm cells exhibit distinct physiology and behaviour in comparison with their planktonic counterparts. They are ubiquitous, resilient and difficult to eradicate due to their resistant phenotype. Several chemical-based cleaning and disinfection regimens are conventionally used against biofilm-dwelling micro-organisms in vitro. Although such approaches are generally considered to be effective, they may contribute to the dissemination of antimicrobial resistance and environmental pollution. Consequently, advanced green technologies for biofilm control are constantly emerging. Disinfection using nonthermal plasmas (NTPs) is one of the novel strategies having a great potential for control of biofilms of a broad spectrum of micro-organisms. This review discusses several aspects related to the inactivation of biofilm-associated bacteria and fungi by different types of NTPs under in vitro conditions. A brief introduction summarizes prevailing methods in biofilm inactivation, followed by introduction to gas discharge plasmas, active plasma species and their inactivating mechanism. Subsequently, significance and aspects of NTP inactivation of biofilm-associated bacteria, especially those of medical importance, including opportunistic pathogens, oral pathogenic bacteria, foodborne pathogens and implant bacteria, are discussed. The remainder of the review discusses majorly about the synergistic effect of NTPs and their activity against biofilm-associated fungi, especially Candida species. © 2017 The Society for Applied Microbiology.

  4. In vitro photodynamic inactivation of Sporothrix schenckii complex species.

    Science.gov (United States)

    Nunes Mario, Débora Alves; Denardi, Laura Bedin; Brayer Pereira, Daniela Isabel; Santurio, Janio Morais; Alves, Sydney Hartz

    2014-10-01

    Photodynamic therapy has been applied successfully against cutaneous and subcutaneous mycoses. We applied methylene blue as a photosensitizing agent and light emitting diode (InGaAlP) against Sporothrix schenckii complex species in an in vitro assay. The viability of the conidia was determined by counting colony-forming units. Methylene blue in conjunction with laser irradiation was able to inhibit the growth of all tested samples. The in vitro inhibition of Sporothrix spp. isolates by laser light deserves in vivo experimental and clinical studies since it may be a promising treatment for cutaneous and subcutaneous sporotrichosis. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. A key inactivation factor of HeLa cell viability by a plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Takehiko; Yokoyama, Mayo [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Johkura, Kohei, E-mail: sato@ifs.tohoku.ac.jp [Department of Histology and Embryology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621 (Japan)

    2011-09-21

    Recently, a plasma flow has been applied to medical treatment using effects of various kinds of stimuli such as chemical species, charged particles, heat, light, shock wave and electric fields. Among them, the chemical species are known to cause an inactivation of cell viability. However, the mechanisms and key factors of this event are not yet clear. In this study, we focused on the effect of H{sub 2}O{sub 2} in plasma-treated culture medium because it is generated in the culture medium and it is also chemically stable compared with free radicals generated by the plasma flow. To elucidate the significance of H{sub 2}O{sub 2}, we assessed the differences in the effects of plasma-treated medium and H{sub 2}O{sub 2}-added medium against inactivation of HeLa cell viability. These two media showed comparable effects on HeLa cells in terms of the survival ratios, morphological features of damage processes, permeations of H{sub 2}O{sub 2} into the cells, response to H{sub 2}O{sub 2} decomposition by catalase and comprehensive gene expression. The results supported that among chemical species generated in a plasma-treated culture medium, H{sub 2}O{sub 2} is one of the main factors responsible for inactivation of HeLa cell viability. (fast track communication)

  6. The role of VUV radiation in the inactivation of bacteria with an atmospheric pressure plasma jet

    CERN Document Server

    Schneider, Simon; Ellerweg, Dirk; Denis, Benjamin; Narberhaus, Franz; Bandow, Julia E; Benedikt, Jan

    2011-01-01

    A modified version of a micro scale atmospheric pressure plasma jet (\\mu-APPJ) source, so-called X-Jet, is used to study the role of plasma generated VUV photons in the inactivation of E. coli bacteria. The plasma is operated in He gas or a He/O2 mixture and the X-Jet modification of the jet geometry allows effective separation of heavy reactive particles (such as O atoms or ozone molecules) from the plasma-generated photons. The measurements of the evolution of zone of inhibitions formed in monolayers of vegetative E. coli bacteria, of VUV emission intensity and of positive ion spectra show that photochemistry in the gas phase followed by photochemistry products impacting on bacteria can result in bacterial inactivation. Interestingly, this process is more effective than direct inactivation by VUV radiation damage. Mainly protonated water cluster ions are detected by mass spectrometry indicating that water impurity has to be carefully considered. The measurements indicate that the combination of the presence...

  7. Non-thermal plasma-activated water inactivation of food-borne pathogen on fresh produce

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruonan; Wang, Guomin; Tian, Ying; Wang, Kaile [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang, Jue, E-mail: zhangjue@pku.edu.cn [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China); Fang, Jing [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China)

    2015-12-30

    Highlights: • We propose a new approach to treat S. aureus inoculated on strawberries by PAW. • PAW could inactivate S. aureus on strawberries via the Log Reduction results, further confirmed by CLSM and SEM. • The short-lived ROS in PAW are considered the most important agents in inactivation process. • No significant change was found in color, firmness and pH of the PAW treated strawberries. - Abstract: Non-thermal plasma has been widely considered to be an effective method for decontamination of foods. Recently, numerous studies report that plasma-activated water (PAW) also has outstanding antibacterial ability. This study presents the first report on the potential of PAW for the inactivation of Staphylococcus aureus (S. aureus) inoculated on strawberries. PAW treatments achieved a reduction of S. aureus ranging from 1.6 to 2.3 log at day-0 storage, while 1.7 to 3.4 log at day-4 storage. The inactivation efficiency depended on the plasma-activated time for PAW generation and PAW-treated time of strawberries inoculated with S. aureus. LIVE/DEAD staining and scanning electron microscopy results confirm that PAW could damage the bacterial cell wall. Moreover, optical emission spectra and oxidation reduction potential results demonstrate the inactivation is mainly attributed to oxidative stress induced by reactive oxygen species in PAW. In addition, no significant change was found in color, firmness and pH of the PAW treated strawberries. Thus, PAW can be a promising alternative to traditional sanitizers applied in the fresh produce industry.

  8. In vitro inactivation of Enterococcus faecalis with a led device.

    Science.gov (United States)

    D'Ercole, S; Spoto, G; Trentini, P; Tripodi, D; Petrini, M

    2016-07-01

    Non-coherent light-emitting diodes (LEDs) are effective in a large variety of clinical indications; however, the bactericidal activity of LEDs is unclear, although the effectiveness of such lights is well known. Currently, no studies have examined the effects of NIR-LED on bacteria. The aims of this study were to verify the antibacterial activity of 880-nm LED irradiation on a bacterial suspension of Enterococcus faecalis and to compare it with the actions of sodium hypochlorite (NaOCl) and the concurrent use of both treatments. Before we proceeded with the main experiment, we first performed preliminary tests to evaluate the influence of such parameters as the distance of irradiation, the energy density, the irradiation time and the presence of photosensitizers on the antimicrobial effects of LEDs. After treatment, the colony forming units per milliliter (CFU/mL) was recorded and the data were submitted to ANOVA and Bonferroni post hoc tests at a level of significance of 5%. The results showed that LED irradiation, at the parameters used, is able to significantly decrease E. faecalis viability in vitro. The total inhibition of E. faecalis was obtained throughout concurrent treatment of LED and NaOCl (1%) for 5min. The same antimicrobial activity was confirmed in all of the experiments (p<0.05), but no statistically significant differences were found by varying such parameters as the distance of irradiation (from 0.5mm to 10mm), energy density (from 2.37 to 8.15mJ/s), irradiation time (from 5min to 20min) or by adding toluidine blue O (TBO). Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Plasma inactivation of microorganisms on sprout seeds in a dielectric barrier discharge.

    Science.gov (United States)

    Butscher, Denis; Van Loon, Hanne; Waskow, Alexandra; Rudolf von Rohr, Philipp; Schuppler, Markus

    2016-12-05

    Fresh produce is frequently contaminated by microorganisms, which may lead to spoilage or even pose a threat to human health. In particular sprouts are considered to be among the most risky foods sold at retail since they are grown in an environment practically ideal for growth of bacteria and usually consumed raw. Because heat treatment has a detrimental effect on the germination abilities of sprout seeds, alternative treatment technologies need to be developed for microbial inactivation purposes. In this study, non-thermal plasma decontamination of sprout seeds is evaluated as a promising option to enhance food safety while maintaining the seed germination capabilities. In detail, investigations focus on understanding the efficiency of non-thermal plasma inactivation of microorganisms as influenced by the type of microbial contamination, substrate surface properties and moisture content, as well as variations in the power input to the plasma device. To evaluate the impact of these parameters, we studied the reduction of native microbiota or artificially applied E. coli on alfalfa, onion, radish and cress seeds exposed to non-thermal plasma in an atmospheric pressure pulsed dielectric barrier discharge streamed with argon. Plasma treatment resulted in a maximum reduction of 3.4 logarithmic units for E. coli on cress seeds. A major challenge in plasma decontamination of granular food products turned out to be the complex surface topology, where the rough surface with cracks and crevices can shield microorganisms from plasma-generated reactive species, thus reducing the treatment efficiency. However, improvement of the inactivation efficiency was possible by optimizing substrate characteristics such as the moisture level and by tuning the power supply settings (voltage, frequency) to increase the production of reactive species. While the germination ability of alfalfa seeds was considerably decreased by harsh plasma treatment, enhanced germination was observed under

  10. Evaluation of pathogen inactivation on sliced cheese induced by encapsulated atmospheric pressure dielectric barrier discharge plasma.

    Science.gov (United States)

    Yong, Hae In; Kim, Hyun-Joo; Park, Sanghoo; Alahakoon, Amali U; Kim, Kijung; Choe, Wonho; Jo, Cheorun

    2015-04-01

    Pathogen inactivation induced by atmospheric pressure dielectric barrier discharge (DBD) (250 W, 15 kHz, air discharge) produced in a rectangular plastic container and the effect of post-treatment storage time on inactivation were evaluated using agar plates and cheese slices. When agar plates were treated with plasma, populations of Escherichia coli, Salmonella Typhimurium, and Listeria monocytogenes showed 3.57, 6.69, and 6.53 decimal reductions at 60 s, 45 s, and 7 min, respectively. When the pathogens tested were inoculated on cheese slices, 2.67, 3.10, and 1.65 decimal reductions were achieved at the same respective treatment times. The post-treatment storage duration following plasma treatment potently affected further reduction in pathogen populations. Therefore, the newly developed encapsulated DBD-plasma system for use in a container can be applied to improve the safety of sliced cheese, and increasing post-treatment storage time can greatly enhance the system's pathogen-inactivation efficiency. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Radiation inactivation target size of rat adipocyte glucose transporters in the plasma membrane and intracellular pools

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, D.B.; Berenski, C.J.; Spangler, R.A.; Jung, C.Y.

    1987-06-15

    The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior to and after insulin treatment, respectively. In the case of microsomal membranes, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses, which may be interpreted as indicating the presence of a radiation-sensitive inhibitor. These results suggest that the adipocyte glucose transporter occurs as a monomer in the plasma membrane while existing in the intracellular reserve pool either as a homodimer or as a stoichiometric complex with a protein of an approximately equal size.

  12. Radiation inactivation target size of rat adipocyte glucose transporters in the plasma membrane and intracellular pools.

    Science.gov (United States)

    Jacobs, D B; Berenski, C J; Spangler, R A; Jung, C Y

    1987-06-15

    The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior to and after insulin treatment, respectively. In the case of microsomal membranes, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses, which may be interpreted as indicating the presence of a radiation-sensitive inhibitor. These results suggest that the adipocyte glucose transporter occurs as a monomer in the plasma membrane while existing in the intracellular reserve pool either as a homodimer or as a stoichiometric complex with a protein of an approximately equal size.

  13. Effects of Background Fluid on the Efficiency of Inactivating Yeast with Non-Thermal Atmospheric Pressure Plasma

    Science.gov (United States)

    Ryu, Young-Hyo; Kim, Yong-Hee; Lee, Jin-Young; Shim, Gun-Bo; Uhm, Han-Sup; Park, Gyungsoon; Choi, Eun Ha

    2013-01-01

    Non-thermal plasma at atmospheric pressure has been actively applied to sterilization. However, its efficiency for inactivating microorganisms often varies depending on microbial species and environments surrounding the microorganisms. We investigated the influence of environmental factors (surrounding media) on the efficiency of microbial inactivation by plasma using an eukaryotic model microbe, Saccharomyces cerevisiae, to elucidate the mechanisms for differential efficiency of sterilization by plasma. Yeast cells treated with plasma in water showed the most severe damage in viability and cell morphology as well as damage to membrane lipids, and genomic DNA. Cells in saline were less damaged compared to those in water, and those in YPD (Yeast extract, Peptone, Dextrose) were least impaired. HOG1 mitogen activated protein kinase was activated in cells exposed to plasma in water and saline. Inactivation of yeast cells in water and saline was due to the acidification of the solutions by plasma, but higher survival of yeast cells treated in saline may have resulted from the additional effect related to salt strength. Levels of hydroxyl radical (OH.) produced by plasma were the highest in water and the lowest in YPD. This may have resulted in differential inactivation of yeast cells in water, saline, and YPD by plasma. Taken together, our data suggest that the surrounding media (environment) can crucially affect the outcomes of yeast cell plasma treatment because plasma modulates vital properties of media, and the toxic nature of plasma can also be altered by the surrounding media. PMID:23799081

  14. Reactive radical-driven bacterial inactivation by hydrogen-peroxide-enhanced plasma-activated-water

    Science.gov (United States)

    Wu, Songjie; Zhang, Qian; Ma, Ruonan; Yu, Shuang; Wang, Kaile; Zhang, Jue; Fang, Jing

    2017-08-01

    The combined effects of plasma activated water (PAW) and hydrogen peroxide (H2O2), PAW/HP, in sterilization were investigated in this study. To assess the synergistic effects of PAW/HP, S. aureus was selected as the test microorganism to determine the inactivation efficacy. Also, the DNA/RNA and proteins released by the bacterial suspensions under different conditions were examined to confirm membrane integrity. Additionally, the intracellular pH (pHi) of S. aureus was measured in our study. Electron spin resonance spectroscopy (ESR) was employed to identify the presence of radicals. Finally, the oxidation reduction potential (ORP), conductivity and pH were measured. Our results revealed that the inactivation efficacy of PAW/HP is much greater than that of PAW, while increased H2O2 concentration result in higher inactivation potential. More importantly, as compared with PAW, the much stronger intensity ESR signals and higher ORP in PAW/HP suggests that the inactivation mechanism of the synergistic effects of PAW/HP: more reactive oxygen species (ROS) and reactive nitrogen species (RNS), especially OH and NO radicals, are generated in PAW combined with H2O2 resulting in more deaths of the bacteria.

  15. Effects of a plasma heating procedure for inactivating Ebola virus on common chemical pathology tests.

    Science.gov (United States)

    Chong, Y K; Ng, W Y; Chen, Sammy P L; Mak, Chloe M

    2015-06-01

    The recent declaration of Ebola virus disease as epidemic by the World Health Organization indicates urgency for affected countries and their laboratories to evaluate and provide treatment to patients potentially infected by the Ebola virus. A heat inactivation procedure involving treating specimens at 60°C for 60 minutes has been suggested for inactivation of the Ebola virus. This study aimed at evaluating the effect of plasma heating on common biochemical tests. Comparative experimental study. A regional chemical pathology laboratory in Hong Kong. Forty consecutive plasma specimens for general chemistry analytes on Beckman Coulter AU5822 and another 40 plasma specimens for troponin I analysis on Access 2 Immunoassay System were obtained, anonymised, and divided into two aliquots. One aliquot was analysed directly and the other was analysed after heating at 60°C for 60 minutes. A total of 20 chemical pathology tests were evaluated. Nine tests (sodium, potassium, chloride, urea, creatinine, total calcium, phosphate, total protein, and glucose) were not significantly affected by the heat inactivation procedure and remained clinically interpretable. Results for magnesium (15% mean increase), albumin (41% mean increase), bilirubin (8% mean decrease), amylase (27% mean decrease), and troponin I (76% mean decrease) were still interpretable using regression estimation with proportional bias. However, all enzymes studied except amylase (alanine transaminase, aspartate transaminase, alkaline phosphatase, gamma-glutamyltransferase, creatine kinase, and lactate dehydrogenase) were inactivated to a significant degree. Their Pearson r or Spearman rho values ranged from no significant correlation (P≥0.05) to 0.767, and most normality was rejected. Heat inactivation results in no significant change in electrolytes, glucose, and renal function tests, but causes a significant bias for many analytes. Recognition of the relationship between pre- and post-heat inactivation

  16. Inactivation of Pathogenic Bacteria on Seeds by Active Oxygen Species Generated in Low-Pressure Plasma

    Science.gov (United States)

    Ono, Reoto; Uchida, Shohei; Hayashi, Nobuya; Kosaka, Rina; Soeda, Yasutaka

    2015-09-01

    The inactivation of bacteria on seeds by active oxygen species generated by a low-pressure oxygen plasma is investigated. Species of active oxygen contributing to the inactivation of bacteria are attempted to be identified. Cylindrical stainless chamber with the internal volume of 17 L is used and RF antenna is set inside the chamber. The oxygen gas pressure is 20-100 Pa. RF power of 13.56 MHz is supplied to RF antenna and CCP is generated. After irradiation, bacteria are extracted from seeds and cultivated on nutrient agars. The number of colonies on these agars is counted after 48 h incubation. The number of bacteria on seeds decreases to less than 10-3 after plasma irradiation for 45 min comparing with that of control. The tendency of the reduction rate of bacteria on seeds has positive correlation with that of the light emission intensity of the singlet excited oxygen molecule as the oxygen gas pressure is varied. It is supposed that the singlet excited oxygen molecule would be one of the major factors for the inactivation of bacteria on seeds.

  17. Inactivation of Salmonella enterica serovar Typhimurium on fresh produce by cold atmospheric gas plasma technology.

    Science.gov (United States)

    Fernández, A; Noriega, E; Thompson, A

    2013-02-01

    Cold atmospheric gas plasma treatment (CAP) is an alternative approach for the decontamination of fresh and minimally processed food. In this study, the effects of growth phase, growth temperature and chemical treatment regime on the inactivation of Salmonella enterica serovar Typhimurium (S. Typhimurium) by Nitrogen CAP were examined. Furthermore, the efficacy of CAP treatment for decontaminating lettuce and strawberry surfaces and potato tissue inoculated with S. Typhimurium was evaluated. It was found that the rate of inactivation of S. Typhimurium was independent of the growth phase, growth temperature and chemical treatment regime. Under optimal conditions, a 2 min treatment resulted in a 2.71 log-reduction of S. Typhimurium viability on membrane filters whereas a 15 min treatment was necessary to achieve 2.72, 1.76 and 0.94 log-reductions of viability on lettuce, strawberry and potato, respectively. We suggest that the differing efficiency of CAP treatment on the inactivation of S. Typhimurium on these different types of fresh foods is a consequence of their surface features. Scanning electron microscopy of the surface structures of contaminated samples of lettuce, strawberry and potato revealed topographical features whereby S. Typhimurium cells could be protected from the active species generated by plasma. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Inactivation of model viruses suspended in fresh frozen plasma using novel methylene blue based device.

    Science.gov (United States)

    Elikaei, Ameneh; Sharifi, Zohreh; Hosseini, Seyed Masoud; Latifi, Hamid; Musavi Hosseini, Mir Kamaran

    2014-02-01

    There is a concern on safety of human Fresh Frozen Plasma (FFP) as it is a source of some medicinal products. The possibility of transmission of blood-borne are reported often due to emerging viruses. There are some Pathogen Reduction Technologies (PRT) to inactivate viruses. Methylene Blue (MB) based method is one of them. The aim of this study was to examine new designated device to inactivate model viruses. Four model viruses were used in this study:Vesicular stomatitis virus (VSV), Herpes Simplex Virus I (HSV-1), Bovine Viral DiarrheaVirus(BVDV) and Polio Virus.50% Tissue Culture Infective Dose (TCID 50) and Reed-Muench Methods were used to titer the viruses. MB in two final concentration of 0.1 μM and 1 μM and illumination in about 627nm with red LED (Lamp Emitting Diode) for 15, 30, 45 and 60 minutes were used. Three replicates employed for each experiments. 1μMconcentration of MB showed more effective than 0.1μMin all designed illumination period for inactivation of HSV, VSV and BVDV. This method also demonstrated best results for enveloped model viruses. The most Log reduction for HSV, VSV and BVDV were6.28, 5.54 and 6.22, respectively. For HSV and BVDV inactivation, the best illumination period was 45 minutes. Model viruses showed sensitivity combination of MB and illumination using red LEDs. As results show this device could inactivate model viruses and reduce their titer very close to approved commercial devices, in compare.

  19. Inactivation and removal of Zika virus during manufacture of plasma-derived medicinal products.

    Science.gov (United States)

    Blümel, Johannes; Musso, Didier; Teitz, Sebastian; Miyabayashi, Tomoyuki; Boller, Klaus; Schnierle, Barbara S; Baylis, Sally A

    2017-03-01

    Zika virus (ZIKV) is an emerging mosquito-borne Flavivirus of major public health concern. The potential for ZIKV transmission by blood transfusion has been demonstrated; however, inactivation or removal of ZIKV during the manufacture of plasma-derived medicinal products has not been specifically investigated. Inactivation of ZIKV by pasteurization and solvent/detergent (S/D) treatment was investigated by spiking high-titer ZIKV stocks into human serum albumin and applying either heat or adding different mixtures of S/D reagents and assaying for infectious virus particles. Removal of ZIKV was evaluated using filters of differing pore sizes (75, 40, 35, and 19 nm), assaying for infectious virus and RNA. Electron microscopy was performed to determine the size of ZIKV particles. Neutralization of virus infectivity by immunoglobulins was investigated. ZIKV was effectively and rapidly inactivated by liquid heat treatment as well as by various mixtures of S/D reagents with reduction factors more than 4 log, in each case. Effective reduction of ZIKV infectivity was demonstrated for virus filtration for filters with average pore sizes of not more than 40 nm, although a significant proportion of virus RNA was detected in the 40- to 35-nm filtrates likely due to the presence of subviral particles observed by electron microscopy. None of the immunoglobulin preparations investigated neutralized ZIKV infectivity. Pasteurization and S/D treatment very rapidly inactivated ZIKV and filters with a pore size of not more than 40 nm removed all infectious ZIKV, demonstrating the effectiveness of these virus reduction strategies used during the manufacture of plasma-derived medicinal products. © 2016 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  20. [Pathogen inactivation in fresh frozen plasma using riboflavin and ultraviolet light: effects on plasma proteins and coagulation factor VII].

    Science.gov (United States)

    Stanojković, Zoran; Antić, Ana

    2011-01-01

    Riboflavin (vitamin B2) activated by ultraviolet (UV) light, produces active oxygen which damages cell membrane and prevents replication of the carrier of diseases (viruses, bacteria, protozoa) in all blood products. The aim of this study was to establish the influence of the process of photo inactivation in pathogens using riboflavin and UV rays on the concentration of coagulation factor VIII:C (FVIII:C) and proteins in plasma that were treated before freezing. The examination included 20 units of plasma, separated from whole blood donated by voluntary blood donors around 6 hours from the moment of collection. The units were pooled and separated in to two groups: one consisted of 10 control units and the other of 10 experimental units. Experimental units of the plasma were treated by riboflavin (35 mL) and UV rays (6.24 J/mL, 265-370 nm) on Mirasol aparature (Caridian BCT Biotechnologies, USA) in approximate duration of 6 minutes. Furthermore, 35 mL of saline solution was added to the control plasma. One sample for examining was taken from the control plasma (KG) and two residual were taken from experimental plasma after the addition of riboflavin either before (EG1) or post illumination (EG2). Results. Comparing the mean values of FVIII:C (%) we noticed statistically significantly higher level in the EG1 group than in the EG2 group (65.00 +/- 4.52 vs. 63.20 +/- 4.73; t = 4.323, p = 0.002), while between the KG and experimental groups (EG1 and EG2) there was no statistically significant difference in the concentration of FVIII:C. There was a statistically significant decrease of albumin concentration (g/L) in the EG2 group comparing to the KG (33.35 +/- 0.94 vs. 31.94 +/- 0.84; t = 3.534, p = 0.002), but there was no mentioned difference in albumin concentration between the KG and the EG1, so as between the EG1 and the EG2. Plasma inactivated by riboflavin and UV rays (Mirasol PRT system, Caridian BCT, U.S.A.) keeps all the characteristics of conventional plasma

  1. Pathogen inactivation in fresh frozen plasma using riboflavin and ultraviolet light: Effects on plasma proteins and coagulation factor VIII

    Directory of Open Access Journals (Sweden)

    Stanojković Zoran

    2011-01-01

    Full Text Available Background/Aim. Riboflavin (vitamin B2 activated by ultraviolet (UV light, produces active oxygen which damages cell membrane and prevents replication of the carrier of diseases (viruses, bacteria, protozoa in all blood products. The aim of this study was to establish the influence of the process of photo inactivation in pathogens using riboflavin and UV rays on the concentration of coagulation factor VIII:C (FVIII:C and proteins in plasma that were treated before freezing. Methods. The examination included 20 units of plasma, separated from whole blood donated by voluntary blood donors around 6 hours from the moment of collection. The units were pooled and separated in to two groups: one consisted of 10 control units and the other of 10 experimental units. Experimental units of the plasma were treated by riboflavin (35 mL and UV rays (6.24 J/mL, 265-370 nm on Mirasol aparature (Caridian BCT Biotechnologies, USA in approximate duration of 6 minutes. Furthermore, 35 mL of saline solution was added to the control plasma. One sample for examining was taken from the control plasma (KG and two residual were taken from experimental plasma after the addition of riboflavin either before (EG1 or post illumination (EG2. Results. Comparing the mean values of FVIII:C (% we noticed statistically significantly higher level in the EG1 group than in the EG2 group (65.00 ± 4.52 vs 63.20 ± 4.73; t = 4.323, p = 0.002, while between the KG and experimental groups (EG1 and EG2 there was no statistically significant difference in the concentration of FVIII:C. There was a statistically significant decrease of albumin concentration (g/L in the EG2 group comparing to the KG (33.35 ± 0.94 vs 31.94 ± 0.84; t = 3.534, p = 0.002, but there was no mentioned difference in albumin concentration between the KG and the EG1, so as between the EG1 and the EG2. Conclusion. Plasma inactivated by riboflavin and UV rays (Mirasol PRT sistem, Caridian BCT, USA keeps all the

  2. Validation of cold plasma treatment for protein inactivation: a surface plasmon resonance-based biosensor study

    Science.gov (United States)

    Bernard, C.; Leduc, A.; Barbeau, J.; Saoudi, B.; Yahia, L'H.; DeCrescenzo, G.

    2006-08-01

    Gas plasma is being proposed as an interesting and promising tool to achieve sterilization. The efficacy of gas plasma to destroy bacterial spores (the most resistant living microorganisms) has been demonstrated and documented over the last ten years. In addition to causing damage to deoxyribonucleic acid by UV radiation emitted by excited species originating from the plasma, gas plasma has been shown to promote erosion of the microorganism in addition to possible oxidation reactions within the microorganism. In this work, we used lysozyme as a protein model to assess the effect of gas plasma on protein inactivation. Lysozyme samples have been subjected to the flowing afterglow of a gas discharge achieved in a nitrogen-oxygen mixture. The efficiency of this plasma treatment on lysozyme has been tested by two different assays. These are an enzyme-linked immunosorbent assay (ELISA) and a surface plasmon resonance (SPR)-based biosensor assay. The two methods showed that exposure to gas plasma can abrogate lysozyme interactions with lysozyme-specific antibodies, more likely by destroying the epitopes responsible for the interaction. More specifically, two SPR-based assays were developed since our ELISA approach did not allow us to discriminate between background and low, but still intact, quantities of lysozyme epitope after plasma treatment. Our SPR results clearly demonstrated that significant protein destruction or desorption was achieved when amounts of lysozyme less than 12.5 ng had been deposited in polystyrene 96-well ELISA plates. At higher lysozyme amounts, traces of available lysozyme epitopes were detected by SPR through indirect measurements. Finally, we demonstrated that a direct SPR approach in which biosensor-immobilized lysozyme activity is directly measured prior and after plasma treatment is more sensitive, and thus, more appropriate to define plasma treatment efficacy with more certainty.

  3. Validation of cold plasma treatment for protein inactivation: a surface plasmon resonance-based biosensor study

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, C [Laboratoire d' Innovation et d' Analyse de Bioperformance (LIAB), Institut de Genie Biomedical, Ecole Polytechnique de Montreal, Montreal Qc, H3C 3A7 (Canada); Leduc, A [Laboratoire de Microbiologie, Faculte de Medecine Dentaire, Universite de Montreal, Montreal Qc, H3C 3J7 (Canada); Barbeau, J [Laboratoire de Microbiologie, Faculte de Medecine Dentaire, Universite de Montreal, Montreal Qc, H3C 3J7 (Canada); Saoudi, B [Groupe de Physique des Plasmas, Universite de Montreal, Montreal Qc, H3C 3J7 (Canada); Yahia, L' H [Laboratoire d' Innovation et d' Analyse de Bioperformance (LIAB), Institut de Genie Biomedical, Ecole Polytechnique de Montreal, Montreal Qc, H3C 3A7 (Canada); Crescenzo, G De [Groupe Bio-P2, Departement de Genie Chimique, Ecole Polytechnique de Montreal, Montreal Qc, H3C 3A7 (Canada)

    2006-08-21

    Gas plasma is being proposed as an interesting and promising tool to achieve sterilization. The efficacy of gas plasma to destroy bacterial spores (the most resistant living microorganisms) has been demonstrated and documented over the last ten years. In addition to causing damage to deoxyribonucleic acid by UV radiation emitted by excited species originating from the plasma, gas plasma has been shown to promote erosion of the microorganism in addition to possible oxidation reactions within the microorganism. In this work, we used lysozyme as a protein model to assess the effect of gas plasma on protein inactivation. Lysozyme samples have been subjected to the flowing afterglow of a gas discharge achieved in a nitrogen-oxygen mixture. The efficiency of this plasma treatment on lysozyme has been tested by two different assays. These are an enzyme-linked immunosorbent assay (ELISA) and a surface plasmon resonance (SPR)-based biosensor assay. The two methods showed that exposure to gas plasma can abrogate lysozyme interactions with lysozyme-specific antibodies, more likely by destroying the epitopes responsible for the interaction. More specifically, two SPR-based assays were developed since our ELISA approach did not allow us to discriminate between background and low, but still intact, quantities of lysozyme epitope after plasma treatment. Our SPR results clearly demonstrated that significant protein destruction or desorption was achieved when amounts of lysozyme less than 12.5 ng had been deposited in polystyrene 96-well ELISA plates. At higher lysozyme amounts, traces of available lysozyme epitopes were detected by SPR through indirect measurements. Finally, we demonstrated that a direct SPR approach in which biosensor-immobilized lysozyme activity is directly measured prior and after plasma treatment is more sensitive, and thus, more appropriate to define plasma treatment efficacy with more certainty.

  4. Inactivation of factor VIIa by antithrombin in vitro, ex vivo and in vivo: role of tissue factor and endothelial cell protein C receptor.

    Directory of Open Access Journals (Sweden)

    Rit Vatsyayan

    Full Text Available Recent studies have suggested that antithrombin (AT could act as a significant physiologic regulator of FVIIa. However, in vitro studies showed that AT could inhibit FVIIa effectively only when it was bound to tissue factor (TF. Circulating blood is known to contain only traces of TF, at best. FVIIa also binds endothelial cell protein C receptor (EPCR, but the role of EPCR on FVIIa inactivation by AT is unknown. The present study was designed to investigate the role of TF and EPCR in inactivation of FVIIa by AT in vivo. Low human TF mice (low TF, ∼ 1% expression of the mouse TF level and high human TF mice (HTF, ∼ 100% of the mouse TF level were injected with human rFVIIa (120 µg kg(-1 body weight via the tail vein. At varying time intervals following rFVIIa administration, blood was collected to measure FVIIa-AT complex and rFVIIa antigen levels in the plasma. Despite the large difference in TF expression in the mice, HTF mice generated only 40-50% more of FVIIa-AT complex as compared to low TF mice. Increasing the concentration of TF in vivo in HTF mice by LPS injection increased the levels of FVIIa-AT complexes by about 25%. No significant differences were found in FVIIa-AT levels among wild-type, EPCR-deficient, and EPCR-overexpressing mice. The levels of FVIIa-AT complex formed in vitro and ex vivo were much lower than that was found in vivo. In summary, our results suggest that traces of TF that may be present in circulating blood or extravascular TF that is transiently exposed during normal vessel damage contributes to inactivation of FVIIa by AT in circulation. However, TF's role in AT inactivation of FVIIa appears to be minor and other factor(s present in plasma, on blood cells or vascular endothelium may play a predominant role in this process.

  5. Preparation, purification and virus inactivation of intravenous immunoglobulin from human plasma.

    Science.gov (United States)

    Aghaie, A; Pourfatollah, A A; Bathaie, S Z; Moazzeni, S M; Khorsand Mohammad Pour, H; Banazadeh, S

    2010-01-01

    IVIG can be prepared from fractionation of normal human plasma and it is used as a therapeutic drug for treatment of various diseases. IVIG has been for some time the high-growth product within the plasma derived products, at both a global and a national country level. Fractionation was performed according to Cohn method with some modifications. Fraction II was first produced and then it was used for purification and virus inactivation steps. Two methods of virus inactivation (pasteurization at 60 degrees C for 10 hours and solvent/detergent treatment with TnBP and Tween 80) were used and validated. A chromatography method (cation exchange chromatography on CM Sepharose FF) was also added to obtain high purity. The final product (in liquid and freeze dried formulation) meets European Pharmacopeias requirements. The amount of PKA and aggregates was beyond the acceptance limit. The intactness of the IVIG was also examined by circular dichroism (secondary and tertiary structure). It was stable after 6 months of storage. Since Iran market is completely dependant on importation of plasma derived products, it is important to develop such methods for production of IVIG to obtain regional demands.

  6. In vitro studies of chlorin e6-assisted photodynamic inactivation of Helicobacter pylori

    Science.gov (United States)

    Simon, C.; Mohrbacher, C.; Hüttenberger, D.; Bauer-Marschall, Ina; Krickhahn, C.; Stachon, A.; Foth, H.-J.

    2014-03-01

    Helicobacter pylori (HP), a gram-negative microaerophilic bacterium located in gastric mucosa, plays an im- portant role in gastro carcinogenesis. Due to the increasing emergence of antibiotic resistance, photodynamic inactivation of bacteria presents a new approach to treat bacterial infections, like HP. In vitro experiments were performed to determine the irradiation conditions for a complete inactivation of HP with the photosensitizer Chlorin e6 (Ce6). The HP strain CCUG 38770 (Culture Collection, University of Gothenburg, Sweden) was routinely cultured under microaerophilic conditions, suspended in sodium chloride, incubated with Ce6 and irradiated briefly with red light of the appropriate wavelength of λ = 660 nm. Series of measurements of different Ce6-concentrations (0.1 μM - 100 μM) were carried out, whereby the incubation time was kept constant at 1 min. The absorbed energy dose has been selected in varying the irradiation time (1 s - 300 s) and the power density (4.5 mW/cm2 - 31 mW/cm2 ). Quantification of inactivation was performed by enumeration of the grown colonies. In addition, the accumulation of Ce6 in HP cells was studied more precisely by uorescence spectroscopy. With a Ce6 concentration of 100 μM and a power density of 9 mW cm2 , a 6-log10 reduction in the survival rate of HP was achieved within 30 seconds of irradiation. In conclusion the most relevant factor for the inactivation of HP is the exposure time of irradiation, followed by the concentration of Ce6 and the light intensity. Further studies with HP strains obtained from patient specimens are under current investigation.

  7. Differential Inactivation of Fungal Spores in Water and on Seeds by Ozone and Arc Discharge Plasma.

    Science.gov (United States)

    Kang, Min Ho; Pengkit, Anchalee; Choi, Kihong; Jeon, Seong Sil; Choi, Hyo Won; Shin, Dong Bum; Choi, Eun Ha; Uhm, Han Sup; Park, Gyungsoon

    2015-01-01

    Seed sterilization is essential for preventing seed borne fungal diseases. Sterilization tools based on physical technologies have recently received much attention. However, available information is very limited in terms of efficiency, safety, and mode of action. In this study, we have examined antifungal activity of ozone and arc discharge plasma, potential tools for seed sterilization. In our results, ozone and arc discharge plasma have shown differential antifungal effects, depending on the environment associated with fungal spores (freely submerged in water or infected seeds). Ozone inactivates Fusarium fujikuroi (fungus causing rice bakanae disease) spores submerged in water more efficiently than arc discharge plasma. However, fungal spores associated with or infecting rice seeds are more effectively deactivated by arc discharge plasma. ROS generated in water by ozone may function as a powerful fungicidal factor. On the other hand, shockwave generated from arc discharge plasma may have greatly contributed to antifungal effects on fungus associated with rice seeds. In support of this notion, addition of ultrasonic wave in ozone generating water has greatly increased the efficiency of seed disinfection.

  8. Differential Inactivation of Fungal Spores in Water and on Seeds by Ozone and Arc Discharge Plasma.

    Directory of Open Access Journals (Sweden)

    Min Ho Kang

    Full Text Available Seed sterilization is essential for preventing seed borne fungal diseases. Sterilization tools based on physical technologies have recently received much attention. However, available information is very limited in terms of efficiency, safety, and mode of action. In this study, we have examined antifungal activity of ozone and arc discharge plasma, potential tools for seed sterilization. In our results, ozone and arc discharge plasma have shown differential antifungal effects, depending on the environment associated with fungal spores (freely submerged in water or infected seeds. Ozone inactivates Fusarium fujikuroi (fungus causing rice bakanae disease spores submerged in water more efficiently than arc discharge plasma. However, fungal spores associated with or infecting rice seeds are more effectively deactivated by arc discharge plasma. ROS generated in water by ozone may function as a powerful fungicidal factor. On the other hand, shockwave generated from arc discharge plasma may have greatly contributed to antifungal effects on fungus associated with rice seeds. In support of this notion, addition of ultrasonic wave in ozone generating water has greatly increased the efficiency of seed disinfection.

  9. Ultraviolet (UV-C inactivation of Enterococcus faecium, Salmonella choleraesuis and Salmonella typhimurium in porcine plasma.

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    Elena Blázquez

    Full Text Available The objective of this study was to assess the effectiveness of an ultraviolet (UV-C, 254 nm irradiation system on reducing the load of Salmonella typhimurium (S. typhimurium, Salmonella choleraesuis (S. choleraesuis resistant to streptomycin and Enterococcus faecium (E. faecium inoculated in sterile porcine plasma and then subjected to different UV-C irradiation doses (750, 1500, 3000, 6000 and 9000 J/L using a pilot plant UV-C device working under turbulent flow. Results indicated that UV-C treatment induced a viability reduction of 0.38, 1.18, 3.59, 4.72 and 5.06 log10 S. typhimurium when irradiated at 750, 1500, 3000, 6000 and 9000 J/L, respectively. The observed log10 reduction of S. choleraesuis was 1.44, 2.68, 5.55, 7.07 and 7.97 at 750, 1500, 3000, 6000 and 9000 J/L, respectively. The best-fit inactivation for S. choleraesuis was the Weibull distribution curve, while the best-fit curve for S. typhimurium was the Weibull plus tail model, indicating that around 102 cfu/mL resistant S. typhimurium was detected when the liquid plasma was UV-C irradiated at doses up to 9000 J/L. Viability reduction for E. faecium was 0.44, 1.01, 3.70, 5.61 and 6.22 log10 when irradiated at 750, 1500, 3000, 6000 and 9000 J/L, respectively, with no bacterial resistance observed with UV-C doses of 6000 J/L or higher. The biphasic model was the best fit model for the inactivation curve for E. faecium. For the three microorganisms tested, about a 4 log-unit reduction was achieved when the liquid plasma was irradiated at 3000J/L. Overall results demonstrate the usefulness of the UV-C system to inactivate bacteria in liquid plasma before spray-drying. We conclude that the UV-C system can provide an additional biosafety feature that can be incorporated into the manufacturing process for spray-dried animal plasma.

  10. Ultraviolet (UV-C) inactivation of Enterococcus faecium, Salmonella choleraesuis and Salmonella typhimurium in porcine plasma.

    Science.gov (United States)

    Blázquez, Elena; Rodríguez, Carmen; Ródenas, Jesús; Pérez de Rozas, Ana; Segalés, Joaquim; Pujols, Joan; Polo, Javier

    2017-01-01

    The objective of this study was to assess the effectiveness of an ultraviolet (UV-C, 254 nm) irradiation system on reducing the load of Salmonella typhimurium (S. typhimurium), Salmonella choleraesuis (S. choleraesuis) resistant to streptomycin and Enterococcus faecium (E. faecium) inoculated in sterile porcine plasma and then subjected to different UV-C irradiation doses (750, 1500, 3000, 6000 and 9000 J/L) using a pilot plant UV-C device working under turbulent flow. Results indicated that UV-C treatment induced a viability reduction of 0.38, 1.18, 3.59, 4.72 and 5.06 log10 S. typhimurium when irradiated at 750, 1500, 3000, 6000 and 9000 J/L, respectively. The observed log10 reduction of S. choleraesuis was 1.44, 2.68, 5.55, 7.07 and 7.97 at 750, 1500, 3000, 6000 and 9000 J/L, respectively. The best-fit inactivation for S. choleraesuis was the Weibull distribution curve, while the best-fit curve for S. typhimurium was the Weibull plus tail model, indicating that around 102 cfu/mL resistant S. typhimurium was detected when the liquid plasma was UV-C irradiated at doses up to 9000 J/L. Viability reduction for E. faecium was 0.44, 1.01, 3.70, 5.61 and 6.22 log10 when irradiated at 750, 1500, 3000, 6000 and 9000 J/L, respectively, with no bacterial resistance observed with UV-C doses of 6000 J/L or higher. The biphasic model was the best fit model for the inactivation curve for E. faecium. For the three microorganisms tested, about a 4 log-unit reduction was achieved when the liquid plasma was irradiated at 3000J/L. Overall results demonstrate the usefulness of the UV-C system to inactivate bacteria in liquid plasma before spray-drying. We conclude that the UV-C system can provide an additional biosafety feature that can be incorporated into the manufacturing process for spray-dried animal plasma.

  11. Impact of surface structure and feed gas composition on Bacillus subtilis endospore inactivation during direct plasma treatment

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    Christian eHertwig

    2015-08-01

    Full Text Available This study investigated the inactivation efficiency of cold atmospheric pressure plasma treatment on Bacillus subtilis endospores dependent on the used feed gas composition and on the surface, the endospores were attached on. Glass petri-dishes, glass beads and peppercorns were inoculated with the same endospore density and treated with a radio frequency plasma jet. Generated reactive species were detected using optical emission spectroscopy. A quantitative polymerase chain reaction (qPCR based ratio detection system was established to monitor the DNA damage during the plasma treatment.Argon + 0.135 % vol. oxygen + 0.2 % vol. nitrogen as feed gas emitted the highest amounts of UV-C photons and considerable amount of reactive oxygen and nitrogen species. Plasma generated with argon + 0.135 % vol. oxygen was characterized by the highest emission of reactive oxygen species, whereas the UV-C emission was negligible. The use of pure argon showed a negligible emission of UV photons and atomic oxygen, however the emission of vacuum (VUV photons was assumed. Similar maximum inactivation results were achieved for the three feed gas compositions.The surface structure had a significant impact on the inactivation efficiency of the plasma treatment. The maximum inactivation achieved was between 2.4 and 2.8 log10 on glass petri-dishes and 3.9 to 4.6 log10 on glass beads. The treatment of peppercorns resulted in an inactivation lower than 1.0 log10. qPCR results showed a significant DNA damage for all gas compositions. Pure argon showed the highest results for the DNA damage ratio values, followed by argon + 0.135 % vol. oxygen + 0.2 % vol. nitrogen. In case of argon + 0.135 % vol. oxygen the inactivation seems to be dominated by the action of reactive oxygen species. These findings indicate the significant role of VUV and UV photons in the inactivation process of Bacillus subtilis endospores.

  12. In Vitro Inactivation of Kudoa septempunctata Spores Infecting the Muscle of Olive Flounder Paralichthys olivaceus.

    Science.gov (United States)

    Yokoyama, Hiroshi; Funaguma, Naoko; Kobayashi, Shoko

    2016-01-01

    Kudoa septempunctata, a myxosporean parasite infecting the trunk muscles of olive flounder (Paralichthys olivaceus), has been recently reported to be the causative agent of a type of food poisoning in humans. Patients exhibited acute diarrhea and vomiting after ingestion of the raw flesh of infected flounder. A recent increase in the number of food-poisoning cases has prompted us to develop a control strategy of this parasite. In this study, we evaluated the efficacy of several temperature and chemical treatments for inactivating K. septempunctata spores in vitro using the vital staining assay with the fluorescent dyes Hoechst 33342 and propidium iodide (PI). Screening tests of treatment methods against K. septempunctata suggested that 25% ethanol for 5 min, 80°C for 10 s, limonene at 10 μL/mL for 5 min, and salinities at 0‰ and 160‰ for 5 min were effective for killing spores. To verify toxicity loss in K. septempunctata spores after the treatments, tight junction barrier integrity assays with Caco-2 cells were conducted. The results of the Caco-2 assays corresponded well with those of the Hoechst 33342-PI staining assay. Further studies are required to determine a practical treatment procedure for inactivating spores considering the treatment application in the production process of cultured olive flounder.

  13. Effect of Surface Roughness in Model and Fresh Fruit Systems on Microbial Inactivation Efficacy of Cold Atmospheric Pressure Plasma.

    Science.gov (United States)

    Bhide, Siddharth; Salvi, Deepti; Schaffner, Donald W; Karwe, Mukund V

    2017-08-01

    This study investigates the efficacy of cold atmospheric pressure plasma (CAPP) on microbial inactivation as influenced by surface roughness of two types of surfaces: sandpaper and fresh fruit peel. Different grits of closed-coat sandpaper were selected, with their roughness (Pq) values ranging from 6 to 16 μm. Apple, orange, and cantaloupe peels were selected for roughness values that were similar to the sandpapers. The sandpapers and the fruit peel surfaces were spot inoculated with Enterobacter aerogenes (109 CFU/63.64 cm2) and exposed to CAPP for 492 s. Similar microbial enumeration techniques were used for both systems to quantify the microbial inactivation. The smoothest sandpaper showed a 0.52-log higher inactivation of E. aerogenes (2.08 log CFU/63.64 cm2 sandpaper surface inactivation) than did the roughest sandpaper (1.56 log CFU/63.64 cm2 sandpaper surface inactivation), and the difference was statistically significant (P fruit peel surface (apple) showed a 1.25-log higher inactivation of the microorganism (1.86 log CFU/63.64 cm2 fruit peel surface inactivation) than did the roughest fresh fruit peel surface (cantaloupe; 0.61 log CFU/63.64 cm2 fruit peel surface inactivation), and the difference was statistically significant (P difference, the microbial inactivation efficacy of CAPP decreased with increasing surface roughness. The results from fruit surfaces show high variability and were not directly predictable from the sandpaper data. This suggests that the microbial inactivation efficacy of CAPP in real-world food systems, such as on fresh fruit peels, is affected by factors in addition to surface roughness.

  14. Effect of two virus inactivation methods. Electron beam irradiation and binary ethylenimine treatment on determination of reproductive hormones in equine plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kyvsgaard, N.C.; Nansen, P. [The Royal Veterinary and Agricultural Univ., Danish Centre for Experimental Parasitology, Frederiksberg (Denmark); Hoeier, R.; Brueck, I. [The Royal Veterinary and Agricultural Univ., Dept. of Clinical Studies, Section of Reproduction, Frederiksberg (Denmark)

    1997-12-31

    Ionizing irradiation and binary ethylenimine treatment have previously been shown to be effective for in-vitro inactivation of virus in biological material. In the present study the 2 methods were tested for possible effects on measurable concentrations of reproductive hormones in equine plasma (luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone (P{sub 4}), and oestradiol-17 {beta} (E{sub 2})). The inactivation methods were electron beam irradiation with a dose from 11 to 44 kGy or treatment with binary ethylenimine (BEI) in concentrations of 1 and 5 mmol/L. Generally, there was a close correlation (r>0.8, p<0.001) between pre- and post-treatment hormone levels. Thus, the different phases of the oestrous cycle could be distinguished on the basis of measured hormone concentrations of treated samples. However, both treatments significantly changed hormone concentrations of the plasma samples. For LH, FSH, and E{sub 2} the effect of irradiation and BEI treatment was depressive and dose-dependant. For P{sub 4} the effect of irradiation was also depressive and dose-dependant. However, the highest dose of BEI resulted in an increase of measured P{sub 4} concentration, which may be attributed to changes in the plasma matrix due to the treatment. Although the treatments affected measured hormone concentrations, the close correlation between pre-treatment and post-treatment measurements means that the diagnostic value will remain unchanged. (au). 17 refs.

  15. Modeling of inactivation of surface borne microorganisms occurring on seeds by cold atmospheric plasma (CAP)

    Science.gov (United States)

    Mitra, Anindita; Li, Y.-F.; Shimizu, T.; Klämpfl, Tobias; Zimmermann, J. L.; Morfill, G. E.

    2012-10-01

    Cold Atmospheric Plasma (CAP) is a fast, low cost, simple, easy to handle technology for biological application. Our group has developed a number of different CAP devices using the microwave technology and the surface micro discharge (SMD) technology. In this study, FlatPlaSter2.0 at different time intervals (0.5 to 5 min) is used for microbial inactivation. There is a continuous demand for deactivation of microorganisms associated with raw foods/seeds without loosing their properties. This research focuses on the kinetics of CAP induced microbial inactivation of naturally growing surface microorganisms on seeds. The data were assessed for log- linear and non-log-linear models for survivor curves as a function of time. The Weibull model showed the best fitting performance of the data. No shoulder and tail was observed. The models are focused in terms of the number of log cycles reduction rather than on classical D-values with statistical measurements. The viability of seeds was not affected for CAP treatment times up to 3 min with our device. The optimum result was observed at 1 min with increased percentage of germination from 60.83% to 89.16% compared to the control. This result suggests the advantage and promising role of CAP in food industry.

  16. Inactivation of Zika virus by solvent/detergent treatment of human plasma and other plasma-derived products and pasteurization of human serum albumin.

    Science.gov (United States)

    Kühnel, Denis; Müller, Sebastian; Pichotta, Alexander; Radomski, Kai Uwe; Volk, Andreas; Schmidt, Torben

    2017-03-01

    In 2016 the World Health Organization declared the mosquito-borne Zika virus (ZIKV) a "public health emergency of international concern." ZIKV is a blood-borne pathogen, which therefore causes concerns regarding the safety of human plasma-derived products due to potential contamination of the blood supply. This study investigated the effectiveness of viral inactivation steps used during the routine manufacturing of various plasma-derived products to reduce ZIKV infectivity. Human plasma and intermediates from the production of various plasma-derived products were spiked with ZIKV and subjected to virus inactivation using the identical techniques (either solvent/detergent [S/D] treatment or pasteurization) and conditions used for the actual production of the respective products. Samples were taken and the viral loads measured before and after inactivation. After S/D treatment of spiked intermediates of the plasma-derived products Octaplas(LG), Octagam, and Octanate, the viral loads were below the limit of detection in all cases. The mean log reduction factor (LRF) was at least 6.78 log for Octaplas(LG), at least 7.00 log for Octagam, and at least 6.18 log for Octanate after 60, 240, and 480 minutes of S/D treatment, respectively. For 25% human serum albumin (HSA), the mean LRF for ZIKV was at least 7.48 log after pasteurization at 60°C for 120 minutes. These results demonstrate that the commonly used virus inactivation processes utilized during the production of human plasma and plasma-derived products, namely, S/D treatment or pasteurization, are effective for inactivation of ZIKV. © 2016 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  17. Nonthermal inactivation of norovirus surrogates on blueberries using atmospheric cold plasma.

    Science.gov (United States)

    Lacombe, Alison; Niemira, Brendan A; Gurtler, Joshua B; Sites, Joseph; Boyd, Glenn; Kingsley, David H; Li, Xinhui; Chen, Haiqiang

    2017-05-01

    Viruses are currently the leading cause of foodborne outbreaks, most of which are associated with foods consumed raw. Cold plasma (CP) is an emerging novel nonthermal technology that can be used to surface decontaminate foods. This study investigated CP technology for the nonthermal inactivation of human norovirus surrogates, Tulane virus (TV) and murine norovirus (MNV), on the surface of blueberries. Blueberries (5 g) were weighed into sterile 4 oz. glass jars and inoculated with TV, 5 log PFU/g. Samples were treated with atmospheric CP for 0, 15, 30, 45, and 60 s at a working distance of 7.5 cm with 4 cubic feet/minute (cfm) of CP jet. Temperature readings were taken with an infrared camera prior to, and immediately following, CP treatments. In order to establish the impact of air flow during CP treatment (4 cfm), an additional 7 cfm jet of room temperature air was introduced from a separate nozzle. The experiment was repeated with 90 and 120 s as additional treatment time points. Viral titers were measured immediately after each treatment with a plaque assay using LLC-MK2 cells (TV) or RAW 264.7 cells (MNV). TV was significantly reduced 1.5 PFU/g compared to the control after treatment time of 45s, which was achieved regardless of temperature conditions. With the addition of 7 cfm of ambient air, the maximum log reduction for TV was 3.5 log PFU/g after 120s of treatment. MNV was significantly reduced by 0.5 log PFU/g compare to the control at 15s, and further treatment of MNV with ambient air brought the log reduction to greater than 5 log PFU/g at 90 s of treatment (Fig. 3). These results demonstrate that CP viral inactivation does not rely on thermal inactivation, and is therefore nonthermal in nature. With further optimization, CP may be used by food processors as a means of nonthermal inactivation of foodborne viruses. Published by Elsevier Ltd.

  18. A comparative study for the inactivation of multidrug resistance bacteria using dielectric barrier discharge and nano-second pulsed plasma.

    Science.gov (United States)

    Park, Ji Hoon; Kumar, Naresh; Park, Dae Hoon; Yusupov, Maksudbek; Neyts, Erik C; Verlackt, Christof C W; Bogaerts, Annemie; Kang, Min Ho; Uhm, Han Sup; Choi, Eun Ha; Attri, Pankaj

    2015-09-09

    Bacteria can be inactivated through various physical and chemical means, and these have always been the focus of extensive research. To further improve the methodology for these ends, two types of plasma systems were investigated: nano-second pulsed plasma (NPP) as liquid discharge plasma and an Argon gas-feeding dielectric barrier discharge (Ar-DBD) as a form of surface plasma. To understand the sterilizing action of these two different plasma sources, we performed experiments with Staphylococcus aureus (S. aureus) bacteria (wild type) and multidrug resistant bacteria (Penicillum-resistant, Methicillin-resistant and Gentamicin-resistant). We observed that both plasma sources can inactivate both the wild type and multidrug-resistant bacteria to a good extent. Moreover, we observed a change in the surface morphology, gene expression and β-lactamase activity. Furthermore, we used X-ray photoelectron spectroscopy to investigate the variation in functional groups (C-H/C-C, C-OH and C=O) of the peptidoglycan (PG) resulting from exposure to plasma species. To obtain atomic scale insight in the plasma-cell interactions and support our experimental observations, we have performed molecular dynamics simulations to study the effects of plasma species, such as OH, H2O2, O, O3, as well as O2 and H2O, on the dissociation/formation of above mentioned functional groups in PG.

  19. Inactivation of Bacillus cereus vegetative cells by gastric acid and bile during in vitro gastrointestinal transit

    Science.gov (United States)

    2012-01-01

    Background The foodborne pathogen Bacillus cereus can cause diarrhoeal food poisoning by production of enterotoxins in the small intestine. The prerequisite for diarrhoeal disease is thus survival during gastrointestinal passage. Methods Vegetative cells of 3 different B. cereus strains were cultivated in a real composite food matrix, lasagne verde, and their survival during subsequent simulation of gastrointestinal passage was assessed using in vitro experiments simulating transit through the human upper gastrointestinal tract (from mouth to small intestine). Results No survival of vegetative cells was observed, despite the high inoculum levels of 7.0 to 8.0 log CFU/g and the presence of various potentially protective food components. Significant fractions (approx. 10% of the consumed inoculum) of B. cereus vegetative cells survived gastric passage, but they were subsequently inactivated by bile exposure in weakly acidic intestinal medium (pH 5.0). In contrast, the low numbers of spores present (up to 4.0 log spores/g) showed excellent survival and remained viable spores throughout the gastrointestinal passage simulation. Conclusion Vegetative cells are inactivated by gastric acid and bile during gastrointestinal passage, while spores are resistant and survive. Therefore, the physiological form (vegetative cells or spores) of the B. cereus consumed determines the subsequent gastrointestinal survival and thus the infective dose, which is expected to be much lower for spores than vegetative cells. No significant differences in gastrointestinal survival ability was found among the different strains. However, considerable strain variability was observed in sporulation tendency during growth in laboratory medium and food, which has important implications for the gastrointestinal survival potential of the different B. cereus strains. PMID:23034184

  20. Inactivation of Candida biofilms by non-thermal plasma and its enhancement for fungistatic effect of antifungal drugs.

    Directory of Open Access Journals (Sweden)

    Yi Sun

    Full Text Available We investigated the antifungal effect of non-thermal plasma, as well as its combination with common antifungal drugs, against Candida biofilms. A direct current atmospheric pressure He/O(2 (2% plasma microjet (PMJ was used to treat Candida biofilms in a 96-well plate. Inactivation efficacies of the biofilms were evaluated by XTT assay and counting colony forming units (CFUs. Morphological properties of the biofilms were evaluated by Scanning Electron Microscope (SEM. The sessile minimal inhibitory concentrations (SMICs of fluconazole, amphotericin B, and caspofungin for the biofilms were also tested. Electron Spin Resonance (ESR spectroscopy was used to detect the reactive oxygen species (ROS generated directly and indirectly by PMJ. The Candida biofilms were completely inactivated after 1 min PMJ treatment, where severely deformed fungal elements were observed in SEM images. The SMICs of the tested antifungal drugs for the plasma-treated biofilms were decreased by 2-6 folds of dilution, compared to those of the untreated controls. ROS such as hydroxyl radical ((•OH, superoxide anion radical ((•O(2 (- and singlet molecular oxygen ((1O(2 were detected by ESR. We hence conclude that He/O(2 (2% plasma alone, as well as in combination with common antifungal drugs, is able to inactivate Candida biofilms rapidly. The generation of ROS is believed to be one of the underlying mechanisms for the fungicidal activity of plasma.

  1. Inactivation of Candida biofilms by non-thermal plasma and its enhancement for fungistatic effect of antifungal drugs.

    Science.gov (United States)

    Sun, Yi; Yu, Shuang; Sun, Peng; Wu, Haiyan; Zhu, Weidong; Liu, Wei; Zhang, Jue; Fang, Jing; Li, Ruoyu

    2012-01-01

    We investigated the antifungal effect of non-thermal plasma, as well as its combination with common antifungal drugs, against Candida biofilms. A direct current atmospheric pressure He/O(2) (2%) plasma microjet (PMJ) was used to treat Candida biofilms in a 96-well plate. Inactivation efficacies of the biofilms were evaluated by XTT assay and counting colony forming units (CFUs). Morphological properties of the biofilms were evaluated by Scanning Electron Microscope (SEM). The sessile minimal inhibitory concentrations (SMICs) of fluconazole, amphotericin B, and caspofungin for the biofilms were also tested. Electron Spin Resonance (ESR) spectroscopy was used to detect the reactive oxygen species (ROS) generated directly and indirectly by PMJ. The Candida biofilms were completely inactivated after 1 min PMJ treatment, where severely deformed fungal elements were observed in SEM images. The SMICs of the tested antifungal drugs for the plasma-treated biofilms were decreased by 2-6 folds of dilution, compared to those of the untreated controls. ROS such as hydroxyl radical ((•)OH), superoxide anion radical ((•)O(2) (-)) and singlet molecular oxygen ((1)O(2)) were detected by ESR. We hence conclude that He/O(2) (2%) plasma alone, as well as in combination with common antifungal drugs, is able to inactivate Candida biofilms rapidly. The generation of ROS is believed to be one of the underlying mechanisms for the fungicidal activity of plasma.

  2. Auranofin inactivates Trichomonas vaginalis thioredoxin reductase and is effective against trichomonads in vitro and in vivo.

    Science.gov (United States)

    Hopper, Melissa; Yun, Jeong-Fil; Zhou, Bianhua; Le, Christine; Kehoe, Katelin; Le, Ryan; Hill, Ryan; Jongeward, Gregg; Debnath, Anjan; Zhang, Liangfang; Miyamoto, Yukiko; Eckmann, Lars; Land, Kirkwood M; Wrischnik, Lisa A

    2016-12-01

    Trichomoniasis, caused by the protozoan parasite Trichomonas vaginalis, is the most common, non-viral, sexually transmitted infection in the world, but only two closely related nitro drugs are approved for its treatment. New antimicrobials against trichomoniasis remain an urgent need. Several organic gold compounds were tested for activity against T. vaginalis thioredoxin reductase (TrxR) in cell-free systems as well as for activity against different trichomonads in vitro and in a murine infection model. The organic gold(I) compounds auranofin and chloro(diethylphenylphosphine)gold(I) inhibited TrxR in a concentration-dependent manner in assays with recombinant purified reductase and in cytoplasmic extracts of T. vaginalis transfected with a haemagglutinin epitope-tagged form of the reductase. Auranofin potently suppressed the growth of three independent clinical T. vaginalis isolates as well as several strains of another trichomonad (Tritrichomonas foetus) in a 24 h-assay, with 50% inhibitory concentrations of 0.7-2.5 µM and minimum lethal concentrations of 2-6 µM. The drug also compromised the ability of the parasite to overcome oxidant stress, supporting the notion that auranofin acts, in part, by inactivating TrxR-dependent antioxidant defences. Chloro(diethylphenylphosphine)gold(I) was 10-fold less effective against T. vaginalis in vitro than auranofin. Oral administration of auranofin for 4 days cleared the parasites in a murine model of vaginal T. foetus infection without displaying any apparent adverse effects. The approved human drug auranofin may be a promising agent as an alternative treatment of trichomoniasis in cases when standard nitro drug therapies have failed. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  3. Inactivation of the AIDS-causing retrovirus and other human viruses in antihemophilic plasma protein preparations by pasteurization.

    Science.gov (United States)

    Hilfenhaus, J; Herrmann, A; Mauler, R; Prince, A M

    1986-01-01

    Heat treatment at 60 degrees C for 10 h in solution (pasteurization) was introduced into the manufacturing process of antihemophilic cryoprecipitate (AHC) and factor VIII concentrates (F VIII) to reduce the risk of transmission of hepatitis to hemophiliacs. Since the acquired immunodeficiency syndrome (AIDS) may also be transmitted to hemophiliacs by antihemophilic plasma protein preparations, we have investigated inactivation of the AIDS virus HTLV III by pasteurization in AHC or F VIII and included in this study cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), poliovirus and vaccinia virus. Each of these viruses was efficiently inactivated by pasteurization although considerable differences were observed between the different viruses HTLV III was rapidly inactivated, becoming nondetectable within 30-60 min. Our findings indicate that pasteurized AHC or F VIII should have a high margin of safety regarding the transmission of AIDS or any other infectious disease caused by viruses such as those tested.

  4. Bacterial inactivation by high-voltage atmospheric cold plasma: influence of process parameters and effects on cell leakage and DNA.

    Science.gov (United States)

    Han, L; Lu, H; Patil, S; Keener, K M; Cullen, P J; Bourke, P

    2014-04-01

    This study investigated a range of atmospheric cold plasma (ACP) process parameters for bacterial inactivation with further investigation of selected parameters on cell membrane integrity and DNA damage. The effects of high voltage levels, mode of exposure, gas mixture and treatment time against Escherichia coli and Listeria monocytogenes were examined. 10(8) CFU ml(-1) E. coli ATCC 25922, E. coli NCTC 12900 and L. monocytogenes NCTC11994 were ACP-treated in 10 ml phosphate-buffered saline (PBS). Working gas mixtures used were air (gas mix 1), 90% N2 + 10% O2 (gas mix 2) and 65% O2 + 30% CO2 + 5% N2 (gas mix 3). Greater reduction of viability was observed for all strains using higher voltage of 70 kVRMS and with working gas mixtures with higher oxygen content in combination with direct exposure. Indirect ACP exposure for 30 s inactivated below detection level both E. coli strains. L. monocytogenes inactivation within 30 s was irrespective of the mode of exposure. Leakage was assessed using A260 absorbance, and DNA damage was monitored using PCR and gel electrophoresis. Membrane integrity was compromised after 5 s, with noticeable DNA damage also dependent on the target cell after 30 s. Plasma treatment was effective for inactivation of challenge micro-organisms, with a greater sensitivity of L. monocytogenes noted. Different damage patterns were observed for the different bacterial strains attributed to the membrane structure and potential resistance mechanisms. Using atmospheric air as working gas resulted in useful inactivation by comparison with high nitrogen or high oxygen mix. The mechanism of inactivation was a function of treatment duration and cell membrane characteristics, thus offering potential for optimized process parameters specific to the microbial challenge. © 2013 The Society for Applied Microbiology.

  5. Inactivation of model viruses and bacteria in human fresh frozen plasma using riboflavin and long wave ultraviolet rays.

    Science.gov (United States)

    Elikaei, Ameneh; Hosseini, Seyed Masoud; Sharifi, Zohreh

    2017-02-01

    Pathogen reduction technologies are among methods to eliminate transfusion transmitted infections. Mirasol method using riboflavin in combination with ultraviolet rays is one of them. The aims of this study were to investigate the effectiveness of Mirasol method to inactivate some model pathogens as well as examination of the sensitivity of plasma proteins after treatment. Riboflavin in 50μM concentration and ultraviolet (365 nm) in three different energy doses (3.6, 7.2, and 10.8 j/cm2) were employed to inactivate model pathogens. Four standard viruses were used in this study including Vesicular Stomatitis Virus (VSV), Herpes Simplex Virus1 (HSV-1), Bovine Viral Diarrhea Virus (BVDV) and Polio Virus. 50% Tissue Culture Infectious Dose (TCID50) and Reed-Muench Methods were used to estimate viruses' titers. E. coli and Staphylococcus aureus were used as bacterial models. Four plasma proteins including factor V, VIII, fibrinogen and antithromin were used to determine their sensitivity to pathogen inactivation treatment. The most pathogen reduction titre was determined for 15 minutes irradiation period equal to 10.8 J/cm2 that is corresponding to Log 6.10 for BVDV, Log 6.09 for HSV-1, Log 6.62 for VSV and Log 3.36 for Polio. Bacterial reduction titer was Log 6.94 for E. coli and Log 7.00 for S. aureus. Indicator proteins for plasma activity were determined to be 75% for factor V, 88% for factor VIII, 52% for fibrinogen and 94% for antithrombin. Results showed that the employed method can inactivate most of the pathogens in fresh frozen plasma. The acceptable activities of selected plasma proteins remained after treatment.

  6. Use of Raman Spectroscopy and Phase-Contrast Microscopy To Characterize Cold Atmospheric Plasma Inactivation of Individual Bacterial Spores.

    Science.gov (United States)

    Wang, Shiwei; Doona, Christopher J; Setlow, Peter; Li, Yong-Qing

    2016-10-01

    Raman spectroscopy and phase-contrast microscopy were used to examine calcium dipicolinate (CaDPA) levels and rates of nutrient and nonnutrient germination of multiple individual Bacillus subtilis spores treated with cold atmospheric plasma (CAP). Major results for this work include the following: (i) >5 logs of spores deposited on glass surfaces were inactivated by CAP treatment for 3 min, while deposited spores placed inside an impermeable plastic bag were inactivated only ∼2 logs in 30 min; (ii) >80% of the spores treated for 1 to 3 min with CAP were nonculturable and retained CaDPA in their core, while >95% of spores treated with CAP for 5 to 10 min lost all CaDPA; (iii) Raman measurements of individual CAP-treated spores without CaDPA showed differences from spores that germinated with l-valine in terms of nucleic acids, lipids, and proteins; and (iv) 1 to 2 min of CAP treatment killed 99% of spores, but these spores still germinated with nutrients or exogenous CaDPA, albeit more slowly and to a lesser extent than untreated spores, while spores CAP treated for >3 min that retained CaDPA did not germinate via nutrients or CaDPA. However, even after 1 to 3 min of CAP treatment, spores germinated normally with dodecylamine. These results suggest that exposure to the present CAP configuration severely damages a spore's inner membrane and key germination proteins, such that the treated spores either lose CaDPA or can neither initiate nor complete germination with nutrients or CaDPA. Analysis of the various CAP components indicated that UV photons contributed minimally to spore inactivation, while charged particles and reactive oxygen species contributed significantly. Much research has shown that cold atmospheric plasma (CAP) is a promising tool for the inactivation of spores in the medical and food industries. However, knowledge about the effects of plasma treatment on spore properties is limited, especially at the single-cell level. In this study, Raman

  7. The effectiveness of riboflavin photochemical-mediated virus inactivation and changes in protein retention in fresh-frozen plasma treated using a flow-based treatment device.

    Science.gov (United States)

    Zhu, Liguo; Pan, Jichun; Wei, Chao; Wang, Haibao; Xiang, Rong; Zhang, Jingang; Wang, Deqing

    2015-01-01

    A flow-based treatment device using riboflavin and ultraviolet (UV) light was developed to inactivate viruses in fresh-frozen plasma (FFP). The objective of this study was to evaluate the in vitro effectiveness of virus inactivation and changes in protein quality in FFP treated with this device. FFP-contaminating viruses were treated with riboflavin and UV light using a one-pass linear flow device. The infectivity of viruses was measured using established biologic assays. Real-time polymerase chain reaction (PCR) was performed to detect damage to viral nucleotides after treatment. Treated plasma was analyzed using standard coagulation assays. FFP treated at the UV dose of 3.6 J/cm(2) (J) exhibited a mean reduction of virus titer of more than 4 logs. The effectiveness increased significantly at higher doses. Real-time PCR showed that the cycle threshold values for both complete inactivation and virus recultivation were higher than that of the untreated sample. At doses of 3.6, 5.4, and 7.2 J, the protein recovery rates were 60.2 ± 8.6, 46.6 ± 9.4, and 28.0 ± 1.0% for fibrinogen; 67.0 ± 3.1, 57.3 ± 8.0, and 49.2 ± 3.8% for Factor VIII; 93.6 ± 2.8, 89.6 ± 6.1, and 86.5 ± 5.3% for antithrombin-III; and 72.1 ± 5.6, 59.8 ± 14.2, and 49.2 ± 8.4% for Protein C, respectively. The effectiveness of virus inactivation was enhanced, but total activity of plasma factors was reduced, in a UV dose-dependent manner. © 2014 The Authors. Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  8. Cold Plasma Inactivation of Bacterial Biofilms and Reduction of Quorum Sensing Regulated Virulence Factors.

    Directory of Open Access Journals (Sweden)

    Dana Ziuzina

    Full Text Available The main objectives of this work were to investigate the effect of atmospheric cold plasma (ACP against a range of microbial biofilms commonly implicated in foodborne and healthcare associated human infections and against P. aeruginosa quorum sensing (QS-regulated virulence factors, such as pyocyanin, elastase (Las B and biofilm formation capacity post-ACP treatment. The effect of processing factors, namely treatment time and mode of plasma exposure on antimicrobial activity of ACP were also examined. Antibiofilm activity was assessed for E. coli, L. monocytogenes and S. aureus in terms of reduction of culturability and retention of metabolic activity using colony count and XTT assays, respectively. All samples were treated 'inpack' using sealed polypropylene containers with a high voltage dielectric barrier discharge ACP generated at 80 kV for 0, 60, 120 and 300 s and a post treatment storage time of 24 h. According to colony counts, ACP treatment for 60 s reduced populations of E. coli to undetectable levels, whereas 300 s was necessary to significantly reduce populations of L. monocytogenes and S. aureus biofilms. The results obtained from XTT assay indicated possible induction of viable but non culturable state of bacteria. With respect to P. aeruginosa QS-related virulence factors, the production of pyocyanin was significantly inhibited after short treatment times, but reduction of elastase was notable only after 300 s and no reduction in actual biofilm formation was achieved post-ACP treatment. Importantly, reduction of virulence factors was associated with reduction of the cytotoxic effects of the bacterial supernatant on CHO-K1 cells, regardless of mode and duration of treatment. The results of this study point to ACP technology as an effective strategy for inactivation of established biofilms and may play an important role in attenuation of virulence of pathogenic bacteria. Further investigation is warranted to propose direct evidence

  9. Inactivation and removal of influenza A virus H1N1 during the manufacture of plasma derivatives.

    Science.gov (United States)

    Jeong, Eun Kyo; Sung, Hark Mo; Kim, In Seop

    2010-11-01

    Although transmission of pandemic influenza A virus H1N1 2009 is still occurring globally, little has been reported about how this outbreak has affected the safety of plasma derivatives. To evaluate the safety of plasma derivatives, dedicated virus clearance processes used during their production were investigated for their effectiveness in eliminating this virus of recent concern. In this study, influenza A virus H1N1 strain A/NWS/33 (H1N1) was chosen as a surrogate. H1N1 was completely inactivated by fraction IV fractionation as well as pasteurization during the manufacture of albumin. H1N1 was also effectively removed into the precipitate by fraction III fractionation and completely inactivated by low pH incubation as well as pasteurization during the manufacture of intravenous immunoglobulin. H1N1 was completely inactivated within 1 min of solvent/detergent treatment using 0.3% tri (n-butyl) phosphate and 1.0% Triton X-100 and also completely inactivated within 10 min of dry-heat treatment at 98 °C during the manufacture of factor VIII. H1N1 was completely removed by virus filtration process using Viresolve NFP filter and also completely inactivated by pasteurization during the manufacture of anti-thrombin III. These results indicate that all the virus clearance processes commonly used have sufficient H1N1 reducing capacity to achieve a high margin of safety. Copyright © 2010 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

  10. Hemostatic properties and protein expression profile of therapeutic apheresis plasma treated with amotosalen and ultraviolet A for pathogen inactivation.

    Science.gov (United States)

    Ohlmann, Philippe; Hechler, Béatrice; Chafey, Philippe; Ravanat, Catherine; Isola, Hervé; Wiesel, Marie-Louise; Cazenave, Jean-Pierre; Gachet, Christian

    2016-09-01

    The INTERCEPT Blood System (IBS) using amotosalen-HCl and ultraviolet (UV)A inactivates a large spectrum of microbial pathogens and white blood cells in therapeutic plasma. Our aim was to evaluate to what extent IBS modifies the capacity of plasma to generate thrombin and induces qualitative or quantitative modifications of plasma proteins. Plasma units from four donors were collected by apheresis. Samples were taken before (control [CTRL]) and after IBS treatment and stored at -80°C until use. The activities of plasma coagulation factors and inhibitors and the thrombin generation potential were determined using assays measuring clotting times and the calibrated automated thrombogram (CAT), respectively. The proteomic profile of plasma proteins was examined using a two-dimensional differential in-gel electrophoresis (2D-DIGE) method. Nearly all of the procoagulant and antithrombotic factors tested retained at least 78% of their initial pre-IBS activity. Only FVII and FVIII displayed a lower level of conservation (67%), which nevertheless remained within the reference range for conventional plasma coagulation factors. The thrombin generation profile of plasma was conserved after IBS treatment. Among the 1331 protein spots revealed by 2D-DIGE analysis, only four were differentially expressed in IBS plasma compared to CTRL plasma and two were identified by mass spectrometric analysis as transthyretin and apolipoprotein A1. The IBS technique for plasma moderately decreases the activities of plasma coagulation factors and antithrombotic proteins, with no impact on the thrombin generation potential of plasma and very limited modifications of the proteomic profile. © 2016 AABB.

  11. Inactivation of a 25.5 µm Enterococcus faecalis biofilm by a room-temperature, battery-operated, handheld air plasma jet

    Science.gov (United States)

    Pei, X.; Lu, X.; Liu, J.; Liu, D.; Yang, Y.; Ostrikov, K.; Chu, Paul K.; Pan, Y.

    2012-04-01

    Effective biofilm inactivation using a handheld, mobile plasma jet powered by a 12 V dc battery and operated in open air without any external gas supply is reported. This cold, room-temperature plasma is produced in self-repetitive nanosecond discharges with current pulses of ˜100 ns duration, current peak amplitude of ˜6 mA and repetition rate of ˜20 kHz. It is shown that the reactive plasma species penetrate to the bottom layer of a 25.5 µm-thick Enterococcus faecalis biofilm and produce a strong bactericidal effect. This is the thickest reported biofilm inactivated using room-temperature air plasmas.

  12. Inactivated probiotic Bacillus coagulans GBI-30 induces complex immune activating, anti-inflammatory, and regenerative markers in vitro

    Directory of Open Access Journals (Sweden)

    Jensen GS

    2017-08-01

    Full Text Available Gitte S Jensen,1 Howard A Cash,2 Sean Farmer,2 David Keller2 1NIS Labs, Esplanade, Klamath Falls, OR, USA, 2Ganeden Biotech Inc., Landerbrook Drive Suite, Mayfield Heights, OH, USA Objective: The aim of this study was to document the immune activating and anti-inflammatory effects of inactivated probiotic Bacillus coagulans GBI-30, 6086 (Staimune™ cells on human immune cells in vitro.Methods: In vitro cultures of human peripheral blood mononuclear cells (PBMC from healthy blood donors were treated with inactivated B. coagulans GBI-30, 6086 cells for 24 hours. After incubation, the PBMC were stained with fluorochrome-labeled monoclonal antibodies for CD3, CD56, and CD69 to monitor cellular activation by flow cytometry. The culture supernatants were tested for cytokine profile using a 27-plex Luminex array, including pro- and anti-inflammatory cytokines, chemokines, and growth factors.Results: Inactivated B. coagulans GBI-30, 6086 cells induced the CD69 early activation marker on CD3+ CD56− T lymphocytes, CD3+ CD56+ NKT cells, CD3−CD56+ NK cells, and also some cells within the CD3−CD56− non-T non-NK cell subset. Culture supernatants showed robust increases in the immune-activating cytokines IL-1β, IL-6, IL-17A, and TNF-α. IFN-γ levels were increased, along with three chemokines, MCP-1, MIP-1α, and MIP-1β. The two anti-inflammatory cytokines IL-1ra and IL-10 showed increases, as well as the G-CSF growth factor involved in repair and stem cell biology. In contrast, GM-CSF levels showed a mild decrease, showing a highly selective growth factor response.Conclusion: The inactivated B. coagulans GBI-30, 6086 cells activated human immune cells and altered the production of both immune activating and anti-inflammatory cytokines and chemokines. Of special importance is the novel demonstration of a selective upregulation of the G-CSF growth factor involved in postinjury and postinflammation repair and regeneration. This suggests that

  13. Inactivation of duck hepatitis B virus by a hydrogen peroxide gas plasma sterilization system: laboratory and 'in use' testing.

    Science.gov (United States)

    Vickery, K; Deva, A K; Zou, J; Kumaradeva, P; Bissett, L; Cossart, Y E

    1999-04-01

    Human hepatitis B virus (HBV) is an important cause of nosocomial infections and can be transmitted by contaminated instruments. However, tests of the efficacy of sterilization of materials and equipment contaminated by HBV are difficult to perform because the virus cannot be cultured in the laboratory. In this study, we aimed to evaluate the capability of a low temperature, hydrogen peroxide gas plasma sterilizer (Sterrad, Advanced Sterilization Products, Irvine California,) to inactivate duck hepatitis B virus (DHBV). In laboratory efficacy studies using DHBV dried on to glass filter carriers and exposed to one-half of the hydrogen peroxide gas plasma sterilization process, there was a 10(7) or greater decrease in the viral titer, with no infectivity detected on the carriers after treatment. In-use studies were performed using a laparoscope that was experimentally contaminated with DHBV to mimic the possible transmission of infection between successive patients. Following exposure to the hydrogen peroxide gas plasma sterilization process no transmission of DHBV infection from the laparoscope occurred despite obvious visual soiling with blood (N = 8) while the transmission rate for the unprocessed laparoscope (positive control) was 100% (26/26), and that for instruments after a water wash was 63% (7/11). In conclusion the hydrogen gas plasma sterilization process completely inactivates DHBV a representative of the hepadna group of viruses.

  14. Involvement of multiple stressors induced by non-thermal plasma-charged aerosols during inactivation of airborne bacteria

    Science.gov (United States)

    Vaze, Nachiket D.; Park, Sin; Brooks, Ari D.; Fridman, Alexander; Joshi, Suresh G.

    2017-01-01

    A lab-scale, tunable, single-filament, point-to-point nonthermal dieletric-barrier discharge (DBD) plasma device was built to study the mechanisms of inactivation of aerosolized bacterial pathogens. The system inactivates airborne antibiotic-resistant pathogens efficiently. Nebulization mediated pre-optimized (4 log and 7 log) bacterial loads were challenged to plasma-charged aerosols, and lethal and sublethal doses determined using colony assay, and cell viability assay; and the loss of membrane potential and cellular respiration were determined using cell membrane potential assay and XTT assay. Using the strategies of Escherichia coli wildtype, over-expression mutant, deletion mutants, and peroxide and heat stress scavenging, we analyzed activation of intracellular reactive oxygen species (ROS) and heat shock protein (hsp) chaperons. Superoxide dismutase deletion mutants (ΔsodA, ΔsodB, ΔsodAΔsodB) and catalase mutants ΔkatG and ΔkatEΔkatG did not show significant difference from wildtype strain, and ΔkatE and ΔahpC was found significantly more susceptible to cell death than wildtype. The oxyR regulon was found to mediate plasma-charged aerosol-induced oxidative stress in bacteria. Hsp deficient E. coli (ΔhtpG, ΔgroEL, ΔclpX, ΔgrpE) showed complete inactivation of cells at ambient temperature, and the treatment at cold temperature (4°C) significantly protected hsp deletion mutants and wildtype cells, and indicate a direct involvement of hsp in plasma-charged aerosol mediated E. coli cell death. PMID:28166240

  15. Involvement of multiple stressors induced by non-thermal plasma-charged aerosols during inactivation of airborne bacteria.

    Directory of Open Access Journals (Sweden)

    Nachiket D Vaze

    Full Text Available A lab-scale, tunable, single-filament, point-to-point nonthermal dieletric-barrier discharge (DBD plasma device was built to study the mechanisms of inactivation of aerosolized bacterial pathogens. The system inactivates airborne antibiotic-resistant pathogens efficiently. Nebulization mediated pre-optimized (4 log and 7 log bacterial loads were challenged to plasma-charged aerosols, and lethal and sublethal doses determined using colony assay, and cell viability assay; and the loss of membrane potential and cellular respiration were determined using cell membrane potential assay and XTT assay. Using the strategies of Escherichia coli wildtype, over-expression mutant, deletion mutants, and peroxide and heat stress scavenging, we analyzed activation of intracellular reactive oxygen species (ROS and heat shock protein (hsp chaperons. Superoxide dismutase deletion mutants (ΔsodA, ΔsodB, ΔsodAΔsodB and catalase mutants ΔkatG and ΔkatEΔkatG did not show significant difference from wildtype strain, and ΔkatE and ΔahpC was found significantly more susceptible to cell death than wildtype. The oxyR regulon was found to mediate plasma-charged aerosol-induced oxidative stress in bacteria. Hsp deficient E. coli (ΔhtpG, ΔgroEL, ΔclpX, ΔgrpE showed complete inactivation of cells at ambient temperature, and the treatment at cold temperature (4°C significantly protected hsp deletion mutants and wildtype cells, and indicate a direct involvement of hsp in plasma-charged aerosol mediated E. coli cell death.

  16. Involvement of multiple stressors induced by non-thermal plasma-charged aerosols during inactivation of airborne bacteria.

    Science.gov (United States)

    Vaze, Nachiket D; Park, Sin; Brooks, Ari D; Fridman, Alexander; Joshi, Suresh G

    2017-01-01

    A lab-scale, tunable, single-filament, point-to-point nonthermal dieletric-barrier discharge (DBD) plasma device was built to study the mechanisms of inactivation of aerosolized bacterial pathogens. The system inactivates airborne antibiotic-resistant pathogens efficiently. Nebulization mediated pre-optimized (4 log and 7 log) bacterial loads were challenged to plasma-charged aerosols, and lethal and sublethal doses determined using colony assay, and cell viability assay; and the loss of membrane potential and cellular respiration were determined using cell membrane potential assay and XTT assay. Using the strategies of Escherichia coli wildtype, over-expression mutant, deletion mutants, and peroxide and heat stress scavenging, we analyzed activation of intracellular reactive oxygen species (ROS) and heat shock protein (hsp) chaperons. Superoxide dismutase deletion mutants (ΔsodA, ΔsodB, ΔsodAΔsodB) and catalase mutants ΔkatG and ΔkatEΔkatG did not show significant difference from wildtype strain, and ΔkatE and ΔahpC was found significantly more susceptible to cell death than wildtype. The oxyR regulon was found to mediate plasma-charged aerosol-induced oxidative stress in bacteria. Hsp deficient E. coli (ΔhtpG, ΔgroEL, ΔclpX, ΔgrpE) showed complete inactivation of cells at ambient temperature, and the treatment at cold temperature (4°C) significantly protected hsp deletion mutants and wildtype cells, and indicate a direct involvement of hsp in plasma-charged aerosol mediated E. coli cell death.

  17. In vitro antimicrobial effects and mechanism of atmospheric-pressure He/O2 plasma jet on Staphylococcus aureus biofilm

    Science.gov (United States)

    Xu, Zimu; Shen, Jie; Cheng, Cheng; Hu, Shuheng; Lan, Yan; Chu, Paul K.

    2017-03-01

    The antimicrobial effects and associated mechanism of inactivation of Staphylococcus aureus (S. aureus) NCTC-8325 biofilms induced by a He/O2 atmospheric-pressure plasma jet (APPJ) are investigated in vitro. According to CFU (colony forming units) counting and the resazurin-based assay, the 10 min He/O2 (0.5%) APPJ treatment produces the optimal inactivation efficacy (>5 log10 ml-1) against the S. aureus biofilm and 5% of the bacteria enter a viable but non-culturable (VBNC) state. Meanwhile, 94% of the bacteria suffer from membrane damage according to SYTO 9/PI counterstaining. Scanning electron microscopy (SEM) reveals that plasma exposure erodes the extracellular polymeric substances (EPS) and then the cellular structure. The H2DCFDA-stained biofilms show larger concentrations of intracellular reactive oxygen species (ROS) in membrane-intact bacteria with increasing plasma dose. The admixture of oxygen in the working gas highly contributes to the deactivation efficacy of the APPJ against S. aureus and the plasma-induced endogenous ROS may work together with the discharge-generated ROS to continuously damage the bacterial membrane structure leading to deactivation of the biofilm microbes.

  18. Oxygen removal during pathogen inactivation with riboflavin and UV light preserves protein function in plasma for transfusion.

    Science.gov (United States)

    Feys, H B; Van Aelst, B; Devreese, K; Devloo, R; Coene, J; Vandekerckhove, P; Compernolle, V

    2014-05-01

    Photochemical pathogen inactivation technologies (PCT) for individual transfusion products act by inhibition of replication through irreversibly damaging nucleic acids. Concern on the collateral impact of PCT on the blood component's integrity has caused reluctance to introduce this technology in routine practice. This work aims to uncover the mechanism of damage to plasma constituents by riboflavin pathogen reduction technology (RF-PRT). Activity and antigen of plasma components were determined following RF-PRT in the presence or absence of dissolved molecular oxygen. Employing ADAMTS13 as a sentinel molecule in plasma, our data show that its activity and antigen are reduced by 23 ± 8% and 29 ± 9% (n = 24), respectively, which corroborates with a mean decrease of 25% observed for other coagulation factors. Western blotting of ADAMTS13 shows decreased molecular integrity, with no obvious indication of additional proteolysis nor is riboflavin able to directly inhibit the enzyme. However, physical removal of dissolved oxygen prior to RF-PRT protects ADAMTS13 as well as FVIII and fibrinogen from damage, indicating a direct role for reactive oxygen species. Redox dye measurements indicate that superoxide anions are specifically generated during RF-PRT. Protein carbonyl content as a marker of disseminated irreversible biomolecular damage was significantly increased (3·1 ± 0·8 vs. 1·6 ± 0·5 nmol/mg protein) following RF-PRT, but not in the absence of dissolved molecular oxygen (1·8 ± 0·4 nmol/mg). RF-PRT of single plasma units generates reactive oxygen species that adversely affect biomolecular integrity of relevant plasma constituents, a side-effect, which can be bypassed by applying hypoxic conditions during the pathogen inactivation process. © 2013 International Society of Blood Transfusion.

  19. A Comprehensive Tutorial on In Vitro Characterization of New Photosensitizers for Photodynamic Antitumor Therapy and Photodynamic Inactivation of Microorganisms

    Directory of Open Access Journals (Sweden)

    Tobias Kiesslich

    2013-01-01

    Full Text Available In vitro research performed on eukaryotic or prokaryotic cell cultures usually represents the initial step for characterization of a novel photosensitizer (PS intended for application in photodynamic therapy (PDT of cancer or photodynamic inactivation (PDI of microorganisms. Although many experimental steps of PS testing make use of the wide spectrum of methods readily employed in cell biology, special aspects of working with photoactive substances, such as the autofluorescence of the PS molecule or the requirement of light protection, need to be considered when performing in vitro experiments in PDT/PDI. This tutorial represents a comprehensive collection of operative instructions, by which, based on photochemical and photophysical properties of a PS, its uptake into cells, the intracellular localization and photodynamic action in both tumor cells and microorganisms novel photoactive molecules may be characterized for their suitability for PDT/PDI. Furthermore, it shall stimulate the efforts to expand the convincing benefits of photodynamic therapy and photodynamic inactivation within both established and new fields of applications and motivate scientists of all disciplines to get involved in photodynamic research.

  20. Atmospheric pressure plasma produced inside a closed package by a dielectric barrier discharge in Ar/CO2 for bacterial inactivation of biological samples

    DEFF Research Database (Denmark)

    Chiper, Alina Silvia; Chen, Weifeng; Mejlholm, Ole

    2011-01-01

    The generation and evaluation of a dielectric barrier discharge produced inside a closed package made of a commercially available packaging film and filled with gas mixtures of Ar/CO2 at atmospheric pressure is reported. The discharge parameters were analysed by electrical measurements and optica...... times higher in the Ar/CO2 plasma compared with an Ar plasma. The efficiency of the produced plasma for the inactivation of bacteria on food inside the closed package was investigated....

  1. Effect of atmospheric cold plasma (ACP) with its extended storage on the inactivation of Escherichia coli inoculated on tomato.

    Science.gov (United States)

    Prasad, Priyanka; Mehta, Deepak; Bansal, Vasudha; Sangwan, Rajender S

    2017-12-01

    The study investigated the efficacy of atmospheric cold plasma (ACP) treatment on inactivation of E. coli load during extended storage period of 48h at both the temperatures of refrigeration (4°C) as well as room (25°C). The tomato samples were spot inoculated with E. coli and exposed to ACP at 15 and 60kV for 5, 10, 15, and 30min followed by their storage at 4°C and 25°C. The highest log reduction of 6logCFUmL -1 was achieved in population of E. coli after 15min of ACP treatment at 60kV, which was sustained up to storage duration of 48h at both the temperatures. Furthermore, significant reduction in E. coli was found at plasma treatment of 60kV in comparison to 15kV. The inactivation of E. coli was significantly (pcoli. In addition, investigation of E. coli exposed tomato surface was done using scanning electron microscopy that clearly showed the breakdown of cell cover of E. coli as a consequence of ACP. The study predicts the promising potential of the technique in sanitization of vegetables that are eaten raw like tomato. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. In vitro photodynamic inactivation of conidia of the phytopathogenic fungus Colletotrichum graminicola with cationic porphyrins.

    Science.gov (United States)

    Vandresen, Camila Chevonica; Gonçalves, Alan Guilherme; Ducatti, Diogo Ricardo Bazan; Murakami, Fabio Seigi; Noseda, Miguel Daniel; Duarte, Maria Eugenia Rabello; Barreira, Sandra Mara Woranovicz

    2016-05-11

    Photodynamic inactivation (PDI) is an efficient approach for the elimination of a series of microorganisms; however, PDI involving phytopathogenic filamentous fungi is scarce in the literature. In the present study, we have demonstrated the photoinactivating properties of five cationic meso-(1-methyl-4-pyridinio)porphyrins on conidia of the phytopathogen Colletotrichum graminicola. For this purpose, photophysical properties (photostability and (1)O2 singlet production) of the porphyrins under study were first evaluated. PDI assays were then performed with a fluence of 30, 60, 90 and 120 J cm(-2) and varying the porphyrin concentration from 1 to 25 μmol L(-1). Considering the lowest concentration that enabled the best photoinactivation, with the respective lowest effective irradiation time, the meso-(1-methyl-4-pyridinio)porphyrins herein studied could be ranked as follows: triple-charged 4 (1 μmol L(-1) with a fluence of 30 J cm(-2)) > double-charged-trans2 (1 μmol L(-1) with 60 J cm(-2)) > tetra-charged 5 (15 μmol L(-1) with 90 J cm(-2)) > mono-charged 1 (25 μmol L(-1) with 120 J cm(-2)). Double-charged-cis-porphyrin 3 inactivated C. graminicola conidia in the absence of light. Evaluation of the porphyrin binding to the conidia and fluorescence microscopic analysis were also performed, which were in agreement with the PDI results. In conclusion, the cationic porphyrins herein studied were considered efficient photosensitizers to inactivate C. graminicola conidia. The amount and position of positive charges are related to the compounds' amphiphilicity and therefore to their photodynamic activity.

  3. A H2 very high frequency capacitively coupled plasma inactivates glyceraldehyde 3-phosphate dehydrogenase(GapDH) more efficiently than UV photons and heat combined

    Science.gov (United States)

    Stapelmann, Katharina; Lackmann, Jan-Wilm; Buerger, Ines; Bandow, Julia Elisabeth; Awakowicz, Peter

    2014-02-01

    Plasma sterilization is a promising alternative to commonly used sterilization techniques, because the conventional methods suffer from certain limitations, e.g. incompatibility with heat-sensitive materials, or use of toxic agents. However, plasma-based sterilization mechanisms are not fully understood yet. A low-pressure very high frequency capacitively coupled plasma is used to investigate the impact of a hydrogen discharge on the protein glyceraldehyde 3-phosphate dehydrogenase (GapDH). GapDH is an enzyme of glycolysis. As a part of the central metabolism, it occurs in nearly all organisms from bacteria to humans. The plasma is investigated with absolutely calibrated optical emission spectroscopy in order to identify and to quantify plasma components that can contribute to enzyme inactivation. The contribution of UV photons and heat to GapDH inactivation is investigated separately, and neither seems to be a major factor. In order to investigate the mechanisms of GapDH inactivation by the hydrogen discharge, samples are investigated for etching, induction of amino acid backbone breaks, and chemical modifications. While neither etching nor strand breaks are observed, chemical modifications occur at different amino acid residues of GapDH. Deamidations of asparagines as well as methionine and cysteine oxidations are detected after VHF-CCP treatment. In particular, oxidation of the cysteine in the active centre is known to lead to GapDH inactivation.

  4. Low pH gel intranasal sprays inactivate influenza viruses in vitro and protect ferrets against influenza infection

    Directory of Open Access Journals (Sweden)

    Lambkin-Williams Robert

    2007-05-01

    Full Text Available Abstract Background Developing strategies for controlling the severity of pandemic influenza is a global public health priority. In the event of a pandemic there may be a place for inexpensive, readily available, effective adjunctive therapies to support containment strategies such as prescription antivirals, vaccines, quarantine and restrictions on travel. Inactivation of virus in the intranasal environment is one possible approach. The work described here investigated the sensitivity of influenza viruses to low pH, and the activity of low pH nasal sprays on the course of an influenza infection in the ferret model. Methods Inactivation of influenza A and avian reassortment influenza was determined using in vitro solutions tests. Low pH nasal sprays were tested using the ferret model with an influenza A Sydney/5/97 challenge. Clinical measures were shed virus, weight loss and body temperature. Results The virus inactivation studies showed that influenza viruses are rapidly inactivated by contact with acid buffered solutions at pH 3.5. The titre of influenza A Sydney/5/97 [H3N2] was reduced by at least 3 log cycles with one minute contact with buffers based on simple acid mixtures such as L-pyroglutamic acid, succinic acid, citric acid and ascorbic acid. A pH 3.5 nasal gel composition containing pyroglutamic acid, succinic acid and zinc acetate reduced titres of influenza A Hong Kong/8/68 [H3N2] by 6 log cycles, and avian reassortment influenza A/Washington/897/80 X A Mallard/New York/6750/78 [H3N2] by 5 log cycles, with 1 min contact. Two ferret challenge studies, with influenza A Sydney/5/97, demonstrated a reduction in the severity of the disease with early application of low pH nasal sprays versus a saline control. In the first study there was decreased weight loss in the treatment groups. In the second study there were reductions in virus shedding and weight loss, most notably when a gelling agent was added to the low pH formulation

  5. Feed gas effect on plasma inactivation mechanism of Salmonella Typhimurium in onion and quality assessment of the treated sample.

    Science.gov (United States)

    Khan, Muhammad Saiful Islam; Lee, Eun-Jung; Hong, Suk-In; Kim, Yun-Ji

    2017-12-18

    A submerged dielectric barrier discharge (DBD) plasma reactor was used to inactivate artificially inoculated reference strains of Salmonella Typhimurium ATCC 14028 on sliced onion (3 cm × 3 cm). Salmonella Typhimurium reductions obtained after 10 min of treatment were 3.96 log CFU/slice and 1.64 log CFU/slice for clean dry air and N2 feed gas, respectively. Variations observed in Optical Emission Spectra (OES) for different feed gases are responsible for the inactivation level variations of Salmonella Typhimurium. The physiochemical properties of the onion slices, such as quercetin content, ascorbic acid content and color parameters, were monitored before and after treatment and the changes that occurred were measured to be in the acceptable range. Quercetin content was reduced only 3.74-5.07% for 10 min treatment, higher reduction was obtained for the use of clean dry air than that of N2 feed gas. Ascorbic acid loss was measured to be 11.82% and 7.98% for a 10 min treatment with clean dry air and N2 feed gas, respectively. The color parameters did not show significant changes upon treatment (p > 0.05) of the same duration for the uses of different feed gases.

  6. Fibrinolysis during liver transplantation is enhanced by using solvent/detergent virus-inactivated plasma (ESDEP)

    NARCIS (Netherlands)

    J. de Jonge (Jeroen); T.H.N. Groenland (Theo); H.J. Metselaar (Herold); L.E. Visser (Loes); H.W. Tilanus (Hugo); H.H.D.M. van Vliet (Huib); J.N.M. IJzermans (Jan)

    2002-01-01

    textabstractAfter the introduction of solvent/detergent-treated plasma (ESDEP) in our hospital, an increased incidence of hyperfibrinolysis was observed (75% vs 29%; P = 0.005) compared with the use of fresh frozen plasma for liver transplantation. To clarify this increased

  7. Immunogenicity and safety of a plasma-derived heat-inactivated hepatitis B vaccine (CLB). Studies in volunteers at a low risk of infection with hepatitis B virus

    NARCIS (Netherlands)

    Lelie, P. N.; Reesink, H. W.; de Jong-van Manen, S. T.; Dees, P. J.; Reerink-Brongers, E. E.

    1984-01-01

    The safety and immunogenicity of a plasma-derived heat-inactivated hepatitis B vaccine (CLB) were evaluated in 471 healthy human volunteers, who, both in their occupations and in their private lives, had been at minimal risk of being infected with hepatitis B virus. The first 202 individuals

  8. Synergistic Effect of Atmospheric-pressure Plasma and TiO2 Photocatalysis on Inactivation of Escherichia coli Cells in Aqueous Media

    Science.gov (United States)

    Zhou, Renwu; Zhou, Rusen; Zhang, Xianhui; Li, Jiangwei; Wang, Xingquan; Chen, Qiang; Yang, Size; Chen, Zhong; Bazaka, Kateryna; (Ken) Ostrikov, Kostya

    2016-01-01

    Atmospheric-pressure plasma and TiO2 photocatalysis have been widely investigated separately for the management and reduction of microorganisms in aqueous solutions. In this paper, the two methods were combined in order to achieve a more profound understanding of their interactions in disinfection of water contaminated by Escherichia coli. Under water discharges carried out by microplasma jet arrays can result in a rapid inactivation of E. coli cells. The inactivation efficiency is largely dependent on the feed gases used, the plasma treatment time, and the discharge power. Compared to atmospheric-pressure N2, He and air microplasma arrays, O2 microplasma had the highest activity against E. coli cells in aqueous solution, and showed >99.9% bacterial inactivation efficiency within 4 min. Addition of TiO2 photocatalytic film to the plasma discharge reactor significantly enhanced the inactivation efficiency of the O2 microplasma system, decreasing the time required to achieve 99.9% killing of E. coli cells to 1 min. This may be attributed to the enhancement of ROS generation due to high catalytic activity and stability of the TiO2 photocatalyst in the combined plasma-TiO2 systems. Present work demonstrated the synergistic effect of the two agents, which can be correlated in order to maximize treatment efficiency. PMID:28004829

  9. In-package inactivation of human pathogenic bacteria and viruses on leafy greens using atmospheric cold plasma as a terminal processing step

    Science.gov (United States)

    Atmospheric cold plasma (ACP) treatment is a novel, promising antimicrobial method. Dieletric barrier discharge forms of ACP are of particular interest, due to their potential for in-package decontamination. The objectives of this work were to quantify ACP inactivation of E. coli O157:H7, Salmonella...

  10. Inactivation of chemical and heat-resistant spores of Bacillus and Geobacillus by nitrogen cold atmospheric plasma and comparison to thermal and chemical based methods

    NARCIS (Netherlands)

    Bokhorst-van de Veen, van H.; Xie, H.; Esveld, D.C.; Abee, T.; Mastwijk, H.C.; Nierop Groot, M.N.

    2015-01-01

    Bacterial spores are resistant to severe conditions and form a challenge to eradicate from food or food packaging material. Cold atmospheric plasma (CAP) treatment is receiving more attention as potential sterilization method at relatively mild conditions but the exact mechanism of inactivation is

  11. Application of a Dielectric Barrier Discharge Atmospheric Cold Plasma (Dbd-Acp) for Eshcerichia Coli Inactivation in Apple Juice.

    Science.gov (United States)

    Liao, Xinyu; Li, Jiao; Muhammad, Aliyu Idris; Suo, Yuanjie; Chen, Shiguo; Ye, Xingqian; Liu, Donghong; Ding, Tian

    2018-02-01

    Atmospheric cold plasma (ACP) is a promising non-thermal technology in food industry. In this study, a dielectric barrier discharge (DBD)-ACP exhibited strong bactericidal effect on Escherichia coli in apple juice. Under a 30 to 50 W input power, less than 40 s treatment time was required for DBD-ACP to result in 3.98 to 4.34 log CFU/mL reduction of E. coli in apple juice. The inactivation behavior of ACP on E. coli was well described by the Weibull model. During the treatment, the cell membrane of E. coli was damaged severely by active species produced by plasma, such as hydrogen peroxide, ozone and nitrate. In addition, the ACP exposure had slight effect on the °Brix, pH, titratable acidity (TA), color values, total phenolic content, and antioxidant capacity of apple juice. However, higher level of DBD-ACP treatment, 50 W for more than 10 s in this case, resulted in significant change of the pH, TA, color and total phenolic content of apple juice. The results in this study have provided insight in potential use of DBD-ACP as an alternative to thermal processing for fruit juices in food industry. Escherichia coli O157:H7 in apple juice is a potential risk for public health. This study demonstrated that 30 s cold plasma treatment resulted in more than 4 log CFU/mL reduction under 50 W, while the quality attributes of apple juice were not significantly affected. Therefore, cold plasma technology is a promising alternative substitute of traditional thermal processing for juice pasteurization. © 2018 Institute of Food Technologists®.

  12. An evolved ribosome-inactivating protein targets and kills human melanoma cells in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Green David E

    2010-02-01

    Full Text Available Abstract Background Few treatment options exist for patients with metastatic melanoma, resulting in poor prognosis. One standard treatment, dacarbazine (DTIC, shows low response rates ranging from 15 to 25 percent with an 8-month median survival time. The development of targeted therapeutics with novel mechanisms of action may improve patient outcome. Ribosome-inactivating proteins (RIPs such as Shiga-like Toxin 1 (SLT-1 represent powerful scaffolds for developing selective anticancer agents. Here we report the discovery and properties of a single chain ribosome-inactivating protein (scRIP derived from the cytotoxic A subunit of SLT-1 (SLT-1A, harboring the 7-amino acid peptide insertion IYSNKLM (termed SLT-1AIYSNKLM allowing the toxin variant to selectively target and kill human melanoma cells. Results SLT-1AIYSNKLM was able to kill 7 of 8 human melanoma cell lines. This scRIP binds to 518-A2 human melanoma cells with a dissociation constant of 18 nM, resulting in the blockage of protein synthesis and apoptosis in such cells. Biodistribution and imaging studies of radiolabeled SLT-1AIYSNKLM administered intravenously into SCID mice bearing a human melanoma xenograft indicate that SLT-1AIYSNKLM readily accumulates at the tumor site as opposed to non-target tissues. Furthermore, the co-administration of SLT-1AIYSNKLM with DTIC resulted in tumor regression and greatly increased survival in this mouse xenograft model in comparison to DTIC or SLT-1AIYSNKLM treatment alone (115 day median survival versus 46 and 47 days respectively; P values IYSNKLM is stable in serum and its intravenous administration resulted in modest immune responses following repeated injections in CD1 mice. Conclusions These results demonstrate that the evolution of a scRIP template can lead to the discovery of novel cancer cell-targeted compounds and in the case of SLT-1AIYSNKLM can specifically kill human melanoma cells in vitro and in vivo.

  13. Chitosan nanoparticles for antimicrobial photodynamic inactivation: characterization and in vitro investigation.

    Science.gov (United States)

    Chen, Chueh-Pin; Chen, Chin-Tin; Tsai, Tsuimin

    2012-01-01

    The growing resistance to antibiotics has rendered antimicrobial photodynamic inactivation (PDI) an attractive alternative treatment modality for infectious diseases. Chitosan (CS) was shown to further potentiate the PDI effect of photosensitizers and was therefore used in this study to investigate its ability to potentiate the activity of erythrosine (ER) against bacteria and yeast. CS nanoparticles loaded with ER were prepared by ionic gelation method and tested for their PDI efficacy on planktonic cells and biofilms of Streptococcus mutans, Pseudomonas aeruginosa and Candida albicans. The nanoparticles were characterized for their size, polydispersity index and zeta potential. No toxicity was observed when planktonic cells and biofilms were treated with the nanoparticles in the dark. However, when the cells were exposed to light irradiation after treatment with free ER or ER/CS nanoparticles, a significant phototoxicity was observed. The antimicrobial activity of ER/CS nanoparticles was significantly higher than ER in free form. The particle size and incubation time of the nanoparticles also appeared to be important factors affecting their PDI activity against S. mutans and C. albicans. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

  14. Inactivation of Candida Strains in Planktonic and Biofilm Forms Using a Direct Current, Atmospheric-Pressure Cold Plasma Micro-Jet

    Science.gov (United States)

    Zhu, Wei-Dong; Sun, Peng; Sun, Yi; Yu, Shuang; Wu, Haiyan; Liu, Wei; Zhang, Jue; Fang, Jing

    A direct-current, atmospheric-pressure, He/O2 (2%) cold plasma ­microjet is applied to Candida species (C. glabrata, C. albicansand C. krusei). Effective inactivation is achieved both in air and in water within 5 min of plasma treatment. Same plasma treatment also successfully inactivated candida biofilms on Petri dish. The inactivation was verified by cell viability test (XTT assay). Severe deformation of Candida biofilms after the plasma treatment was observed through scanning electron microscope (SEM). Optical emission spectroscopy shows strong atomic oxygen emission at 777 nm. Hydroxyl radical (•OH), superoxide anion radical (•O2-) and singlet molecular oxygen (1O2) are detected by electron spin resonance (ESR) spectroscopy. The sessile minimal inhibitory concentrations (SMICs) of fluconazole, amphotericin B, and caspofungin against the Candida spp. biofilms were decreased to 2-6 fold dilutions in plasma microjet treated group in comparison with the controls. This novel approach may become a new tool for the treatment of clinical dermatosis

  15. Inactivation of Gram-Negative Bacteria by Low-Pressure RF Remote Plasma Excited in N2-O2 Mixture and SF6 Gases

    Directory of Open Access Journals (Sweden)

    Ayman Al-Mariri

    2013-12-01

    Full Text Available The role of low-pressure RF plasma in the inactivation of Escherichia coli O157, Klebsiella pneumoniae, Proteus mirabilis, and Enterobacter sakazakii using N2-O2 and SF6 gases was assessed. 1×109 colony-forming units (CFUs of each bacterial isolate were placed on three polymer foils. The effects of pressure, power, distance from the source, and exposure time to plasma gases were optimized. The best conditions to inactivate the four bacteria were a 91%N2-9%O2 mixture and a 30-minute exposure time. SF6 gas was more efficient for all the tested isolates in as much as the treatment time was reduced to only three minutes. Therefore, low-pressure plasma could be used to sterilize heat and/or moisture-sensitive medical instruments.

  16. In vitro sensitivity of Candida spp. to hematoporphyrin monomethyl ether-mediated photodynamic inactivation

    Science.gov (United States)

    Wang, Yucheng; Wang, Ying; Wu, Sumin; Gu, Ying

    2014-11-01

    Background: An increasing prevalence of Candida infections has emerged with the wide use of immune-suppressants and antibiotics. Current antifungal drugs exhibit low efficiency and high toxicity to the normal organs. Photodynamic inactivation (PDI) provides an alternative therapeutic strategy involving the use of photosensitizer (PS) and light irradiation. This study evaluated PDI effects against strains of C. albicans, C. parapsilosis, C. krusei and C. glabrata, using the PS of hematoporphyrin monomethyl ether (HMME), which is a second-generation PS clinically approved in China. Methods: Suspensions (~106 CFU/ml) were incubated with seven HMME concentrations (0.25~50 μM) for 30 min followed by 532-nm laser irradiation for 10 min at 40 mW/cm2. Viability of cells was assayed by CFU counting. Furthermore, fetal calf serum (10%) and singlet oxygen quencher sodium azide (100mM) were respectively added to the suspension of C. krusei to evaluate their roles in PDI process. Results: Among the four species, C. albicans was the most sensitive to PDI; 4 log10 killing was achieved at the concentration of 7.5 μM. C. glabrata was the most resistant; 3 log10 killing was not obtained even at PS concentration of 50 μM. PDI effects against C. krusei were inhibited by both serum and sodium azide. Conclusions: HMME-mediated PDI was able to effectively kill Candida in our experimental conditions, mainly through a Type Ⅱ photoprocess. However, the effects could be intensively reversed by the presence of serum. Thus, there might be a long way before HMME can be used in fighting against Candida in real infectious foci.

  17. Cold plasma inactivates salmonella on grape tomatoes in a commercial PET plastic container without affecting quality

    Science.gov (United States)

    Introduction: The number of outbreaks of foodborne illnesses associated with the consumption of fresh tomatoes has increased. Little research has been conducted on the effects of direct treatment of cold plasma (CP) on the microbial decontamination and preservation of bulk tomatoes packaged in comme...

  18. Cold plasma inactivation of human pathogens on foods and regulatory status update

    Science.gov (United States)

    Contamination of foods with human pathogens such as Salmonella, Listeria monocytogenes, Escherichia coli O157:H7, norovirus, and other pathogens is an ongoing challenge for growers and processors. In recent years, cold plasma has emerged as a promising antimicrobial treatment for fresh and fresh-cut...

  19. Nonthermal inactivation of the norovirus surrogate tulane virus on blueberries using atmospheric cold plasma

    Science.gov (United States)

    Viruses are currently the leading cause of foodborne outbreaks, most of which are associated with foods consumed raw. Cold plasma (CP) is an emerging novel nonthermal technology that can be used for the surface decontamination of foods. This study investigated CP technology for the nonthermal inacti...

  20. Treatment of blood with a pathogen reduction technology using ultraviolet light and riboflavin inactivates Ebola virus in vitro.

    Science.gov (United States)

    Cap, Andrew P; Pidcoke, Heather F; Keil, Shawn D; Staples, Hilary M; Anantpadma, Manu; Carrion, Ricardo; Davey, Robert A; Frazer-Abel, Ashley; Taylor, Audra L; Gonzales, Richard; Patterson, Jean L; Goodrich, Raymond P

    2016-03-01

    Transfusion of plasma from recovered patients after Ebolavirus (EBOV) infection, typically called "convalescent plasma," is an effective treatment for active disease available in endemic areas, but carries the risk of introducing other pathogens, including other strains of EBOV. A pathogen reduction technology using ultraviolet light and riboflavin (UV+RB) is effective against multiple enveloped, negative-sense, single-stranded RNA viruses that are similar in structure to EBOV. We hypothesized that UV+RB is effective against EBOV in blood products without activating complement or reducing protective immunoglobulin titers that are important for the treatment of Ebola virus disease (EVD). Four in vitro experiments were conducted to evaluate effects of UV+RB on green fluorescent protein EBOV (EBOV-GFP), wild-type EBOV in serum, and whole blood, respectively, and on immunoglobulins and complement in plasma. Initial titers for Experiments 1 to 3 were 4.21 log GFP units/mL, 4.96 log infectious units/mL, and 4.23 log plaque-forming units/mL. Conditions tested in the first three experiments included the following: 1-EBOV-GFP plus UV+RB; 2-EBOV-GFP plus RB only; 3-EBOV-GFP plus UV only; 4-EBOV-GFP without RB or UV; 5-virus-free control plus UV only; and 6-virus-free control without RB or UV. UV+RB reduced EBOV titers to nondetectable levels in both nonhuman primate serum (≥2.8- to 3.2-log reduction) and human whole blood (≥3.0-log reduction) without decreasing protective antibody titers in human plasma. Our in vitro results demonstrate that the UV+RB treatment efficiently reduces EBOV titers to below limits of detection in both serum and whole blood. In vivo testing to determine whether UV+RB can improve convalescent blood product safety is indicated. © 2016 AABB.

  1. Chitosan nanoparticles enhance the efficiency of methylene blue-mediated antimicrobial photodynamic inactivation of bacterial biofilms: An in vitro study.

    Science.gov (United States)

    Darabpour, Esmaeil; Kashef, Nasim; Mashayekhan, Shohreh

    2016-06-01

    Biodegradable chitosan nanoparticles (CSNPs) with an intrinsic antimicrobial activity may be a good choice to improve the effectiveness of antimicrobial photodynamic inactivation (APDI). The aim of this study was to investigate the effect of CSNPs on the efficiency of methylene blue (MB)-mediated APDI of Staphylococcus aureus and Pseudomonas aeruginosa biofilms. We also assessed the phototoxicity of MB+CSNPs towards human fibroblasts. CSNPs were prepared using ionic gelation method and characterized by dynamic light scattering (DLS) and field-emission scanning electron microscope (FESEM). Biofilms were developed in a 96-well polystyrene plate for 24h. In vitro phototoxic effect of MB+CSNPs (at final concentrations of 50μM MB) at fluence of 22.93J/cm(2)) on biofilms were studied. Appropriate controls were included. Also, in vitro cytotoxicity and phototoxicity of the above mixture was assessed on human dermal fibroblasts. DLS and FESEM measurements confirmed the nanometric size of the prepared CSNPs. APDI mediated by the mixture of MB and CSNPs showed significant anti-biofilm photoinactivation (P3 and >2 log10 CFU reduction in S. aureus and P. aeruginosa biofilms, respectively) while MB-induced APDI led to approximately <1 log10 CFU reduction. At the same experimental conditions, only 25.1% of the fibroblasts were photoinactivated by MB+CSNPs. Our findings showed that CSNPs enhanced the efficacy of MB-APDI; it may be due to the disruption of biofilm structure by polycationic CSNPs and subsequently deeper and higher penetration of MB into the biofilms. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Ultraviolet (UV-C) inactivation of Enterococcus faecium, Salmonella choleraesuis and Salmonella typhimurium in porcine plasma

    OpenAIRE

    Bl?zquez, Elena; Rodr?guez, Carmen; R?denas, Jes?s; P?rez de Rozas, Ana; Segal?s, Joaquim; Pujols, Joan; Polo, Javier

    2017-01-01

    The objective of this study was to assess the effectiveness of an ultraviolet (UV-C, 254 nm) irradiation system on reducing the load of Salmonella typhimurium (S. typhimurium), Salmonella choleraesuis (S. choleraesuis) resistant to streptomycin and Enterococcus faecium (E. faecium) inoculated in sterile porcine plasma and then subjected to different UV-C irradiation doses (750, 1500, 3000, 6000 and 9000 J/L) using a pilot plant UV-C device working under turbulent flow. Results indicated that ...

  3. Oxidative modification and electrochemical inactivation of Escherichia coli upon cold atmospheric pressure plasma exposure.

    Directory of Open Access Journals (Sweden)

    Marlène Dezest

    Full Text Available Cold atmospheric pressure plasmas (CAPPs are known to have bactericidal effects but the mechanism of their interaction with microorganisms remains poorly understood. In this study the bacteria Escherichia coli were used as a model and were exposed to CAPPs. Different gas compositions, helium with or without adjunctions of nitrogen or oxygen, were used. Our results indicated that CAPP induced bacterial death at decontamination levels depend on the duration, post-treatment storage and the gas mixture composition used for the treatment. The plasma containing O2 in the feeding gas was the most aggressive and showed faster bactericidal effects. Structural modifications of treated bacteria were observed, especially significant was membrane leakage and morphological changes. Oxidative stress caused by plasma treatment led to significant damage of E. coli. Biochemical analyses of bacterial macromolecules indicated massive intracellular protein oxidation. However, reactive oxygen and nitrogen species (RONS are not the only actors involved in E. coli's death, electrical field and charged particles could play a significant role especially for He-O2 CAPP.

  4. Cold plasma inactivation of internalised bacteria and biofilms for Salmonella enterica serovar Typhimurium, Listeria monocytogenes and Escherichia coli.

    Science.gov (United States)

    Ziuzina, Dana; Han, Lu; Cullen, Patrick J; Bourke, Paula

    2015-10-01

    Microbial biofilms and bacteria internalised in produce tissue may reduce the effectiveness of decontamination methods. In this study, the inactivation efficacy of in-package atmospheric cold plasma (ACP) afterglow was investigated against Salmonella Typhimurium, Listeria monocytogenes and Escherichia coli in the forms of planktonic cultures, biofilms formed on lettuce and associated bacteria internalised in lettuce tissue. Prepared lettuce broth (3%) was inoculated with bacteria resulting in a final concentration of ~7.0 log10 CFU/ml. For biofilm formation and internalisation, lettuce pieces (5 × 5 cm) were dip-inoculated in bacterial suspension of ~7.0 log10 CFU/ml for 2 h and further incubated for 0, 24 and 48 h at either 4 °C or room temperature (~22 °C) in combination with light/dark photoperiod or at 4 °C under dark conditions. Inoculated samples were sealed inside a rigid polypropylene container and indirectly exposed (i.e. placed outside plasma discharge) to a high voltage (80 kVRMS) air ACP with subsequent storage for 24 h at 4 °C. ACP treatment for 30s reduced planktonic populations of Salmonella, L. monocytogenes and E. coli suspended in lettuce broth to undetectable levels. Depending on storage conditions, bacterial type and age of biofilm, 300 s of treatment resulted in reduction of biofilm populations on lettuce by a maximum of 5 log10 CFU/sample. Scanning electron and confocal laser microscopy pointed to the incidence of bacterial internalisation and biofilm formation, which influenced the inactivation efficacy of ACP. Measured intracellular reactive oxygen species (ROS) revealed that the presence of organic matter in the bacterial suspension might present a protective effect against the action of ROS on bacterial cells. This study demonstrated that high voltage in-package ACP could be a potential technology to overcome bacterial challenges associated with food produce. However, the existence of biofilms and internalised bacteria should be

  5. Evaluation of the treatment of both sides of raw chicken breasts with an atmospheric pressure plasma jet for the inactivation of Escherichia coli.

    Science.gov (United States)

    Yong, Hae In; Kim, Hyun-Joo; Park, Sanghoo; Choe, Wonho; Oh, Mi Wha; Jo, Cheorun

    2014-08-01

    Atmospheric pressure plasma (APP) is an emerging nonthermal microbial inactivation technique. In this study, agar and raw chicken breast were inoculated with Escherichia coli and treated with an APP jet based on cold arc plasma. The aim of this study was to investigate the optimum conditions for the plasma treatment of an APP jet in order to maximize the efficiency of E. coli inactivation. The combination of N2+O2 (10 standard cubic centimeters per minute) and a longer treatment time (10 min) resulted in the highest inactivation of E. coli on agar plates with an optimum treatment distance of 20 mm. The samples in dry and wet conditions showed similar reductions in E. coli count when one side of the samples was treated at a given treatment time. Treating both sides-2.5 min on each side-resulted in a higher growth inhibition of E. coli than treatment of a single side only for 5 min. However, there was no significant difference between one-side treated samples (10 min) and both-sides treated samples (5+5 min). When the concentration of E. coli in the chicken breast sample was 10(4) colony-forming units (CFU)/g, the reduction rate of the E. coli was the highest, followed by 10(5), 10(6), and 10(7) CFU/g; however, no difference was found between 10(3) and 10(4) CFU/g. In conclusion, various treatment conditions may affect the inactivation efficiency of E. coli. In the present study, the optimum condition was determined as the treatment distance of 20 mm and longer treatment time (10 min) with the addition of oxygen to the nitrogen gas flow. Furthermore, the cell concentration of sample was an important parameter for the efficacy of the inactivation process.

  6. Hepatitis E virus derived from different sources exhibits different behaviour in virus inactivation and/or removal studies with plasma derivatives.

    Science.gov (United States)

    Yunoki, Mikihiro; Tanaka, Hiroyuki; Takahashi, Kadue; Urayama, Takeru; Hattori, Shinji; Ideno, Shoji; Furuki, Rie; Sakai, Kaoru; Hagiwara, Katsuro; Ikuta, Kazuyoshi

    2016-09-01

    Hepatitis E virus (HEV) causes viral hepatitis, and is considered a risk factor for blood products. Although some HEV inactivation/removal studies have been reported, detailed investigations of different manufacturing steps as heat treatment, partitioning during cold ethanol fractionation, low pH treatment, and virus filtration have yet to be reported for plasma-derived medicinal products. In this study, human serum- and swine faeces-derived HEVs, with and without detergent treatment, were used. The kinetic patterns of inactivation, log reduction value, or partitioning during the process were evaluated. In addition, the mouse encephalomyocarditis virus (EMCV) and canine and porcine parvoviruses (CPV/PPV) were also evaluated as model viruses for HEV. Small pore size (19 or 15 nm) virus filtration demonstrated effective removal of HEV. Middle pore size (35 nm) virus filtration and 60 °C liquid heating demonstrated moderate inactivation/removal. Ethanol fractionation steps demonstrated limited removal of HEV. Unpurified HEV exhibited different properties than the detergent-treated HEV, and both forms displayed differences when compared with EMCV, CPV, and PPV. Limited or no inactivation of HEV was observed during low pH treatment. Untreated plasma-derived HEV from humans showed different properties compared to that of HEV treated with detergent or derived from swine faeces. Therefore, HEV spike preparation requires more attention. Copyright © 2016 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  7. In vitro Inactivation of Latent HSV by Targeted Mutagenesis Using an HSV-specific Homing Endonuclease

    Directory of Open Access Journals (Sweden)

    Martine Aubert

    2014-01-01

    Full Text Available Following acute infection, herpes simplex virus (HSV establishes latency in sensory neurons, from which it can reactivate and cause recurrent disease. Available antiviral therapies do not affect latent viral genomes; therefore, they do not prevent reactivation following therapy cessation. One possible curative approach involves the introduction of DNA double strand breaks in latent HSV genomes by rare-cutting endonucleases, leading to mutagenesis of essential viral genes. We tested this approach in an in vitro HSV latency model using the engineered homing endonuclease (HE HSV1m5, which recognizes a sequence in the HSV-1 gene UL19, encoding the virion protein VP5. Coexpression of the 3′-exonuclease Trex2 with HEs increased HE-mediated mutagenesis frequencies up to sixfold. Following HSV1m5/Trex2 delivery with adeno-associated viral (AAV vectors, the target site was mutated in latent HSV genomes with no detectable cell toxicity. Importantly, HSV production by latently infected cells after reactivation was decreased after HSV1m5/Trex2 exposure. Exposure to histone deacetylase inhibitors prior to HSV1m5/Trex2 treatment increased mutagenesis frequencies of latent HSV genomes another two- to fivefold, suggesting that chromatin modification may be a useful adjunct to gene-targeting approaches. These results support the continuing development of HEs and other nucleases (ZFNs, TALENs, CRISPRs for cure of chronic viral infections.

  8. In vitro Inactivation of Latent HSV by Targeted Mutagenesis Using an HSV-specific Homing Endonuclease.

    Science.gov (United States)

    Aubert, Martine; Boyle, Nicole M; Stone, Daniel; Stensland, Laurence; Huang, Meei-Li; Magaret, Amalia S; Galetto, Roman; Rawlings, David J; Scharenberg, Andrew M; Jerome, Keith R

    2014-02-04

    Following acute infection, herpes simplex virus (HSV) establishes latency in sensory neurons, from which it can reactivate and cause recurrent disease. Available antiviral therapies do not affect latent viral genomes; therefore, they do not prevent reactivation following therapy cessation. One possible curative approach involves the introduction of DNA double strand breaks in latent HSV genomes by rare-cutting endonucleases, leading to mutagenesis of essential viral genes. We tested this approach in an in vitro HSV latency model using the engineered homing endonuclease (HE) HSV1m5, which recognizes a sequence in the HSV-1 gene UL19, encoding the virion protein VP5. Coexpression of the 3'-exonuclease Trex2 with HEs increased HE-mediated mutagenesis frequencies up to sixfold. Following HSV1m5/Trex2 delivery with adeno-associated viral (AAV) vectors, the target site was mutated in latent HSV genomes with no detectable cell toxicity. Importantly, HSV production by latently infected cells after reactivation was decreased after HSV1m5/Trex2 exposure. Exposure to histone deacetylase inhibitors prior to HSV1m5/Trex2 treatment increased mutagenesis frequencies of latent HSV genomes another two- to fivefold, suggesting that chromatin modification may be a useful adjunct to gene-targeting approaches. These results support the continuing development of HEs and other nucleases (ZFNs, TALENs, CRISPRs) for cure of chronic viral infections.Molecular Therapy-Nucleic Acids (2014) 3, e1; doi:10.1038/mtna.2013.75; published online 4 February 2014.

  9. Atmospheric cold plasma inactivation of aerobic microorganisms on blueberries and effects on quality attributes.

    Science.gov (United States)

    Lacombe, Alison; Niemira, Brendan A; Gurtler, Joshua B; Fan, Xuetong; Sites, Joseph; Boyd, Glenn; Chen, Haiqiang

    2015-04-01

    Cold plasma (CP) is a novel nonthermal technology, potentially useful in food processing settings. Berries were treated with atmospheric CP for 0, 15, 30, 45, 60, 90, or 120 s at a working distance of 7.5 cm with a mixture of 4 cubic feet/minute (cfm) of CP jet and 7 cfm of ambient air. Blueberries were sampled for total aerobic plate count (APC) and yeast/molds immediately after treatment and at 1, 2, and 7 days. Blueberries were also analyzed for compression firmness, surface color, and total anthocyanins immediately after each treatment. All treatments with CP significantly (P blueberries and could be optimized to improve the safety and quality of produce. Published by Elsevier Ltd.

  10. Sterilization/disinfection of medical devices using plasma: the flowing afterglow of the reduced-pressure N2-O2 discharge as the inactivating medium

    Science.gov (United States)

    Moisan, Michel; Boudam, Karim; Carignan, Denis; Kéroack, Danielle; Levif, Pierre; Barbeau, Jean; Séguin, Jacynthe; Kutasi, Kinga; Elmoualij, Benaïssa; Thellin, Olivier; Zorzi, Willy

    2013-07-01

    Potential sterilization/disinfection of medical devices (MDs) is investigated using a specific plasma process developed at the Université de Montréal over the last decade. The inactivating medium of the microorganisms is the flowing afterglow of a reduced-pressure N2-O2 discharge, which provides, as the main biocidal agent, photons over a broad ultraviolet (UV) wavelength range. The flowing afterglow is considered less damaging to MDs than the discharge itself. Working at gas pressures in the 400—700 Pa range (a few torr) ensures, through species diffusion, the uniform filling of large volume chambers with the species outflowing from the discharge, possibly allowing batch processing within them. As a rule, bacterial endospores are used as bio-indicators (BI) to validate sterilization processes. Under the present operating conditions, Bacillus atrophaeus is found to be the most resistant one and is therefore utilized as BI. The current paper reviews the main experimental results concerning the operation and characterization of this sterilizer/disinfector, updating and completing some of our previously published papers. It uses modeling results as guidelines, which are particularly useful when the corresponding experimental data are not (yet) available, hopefully leading to more insight into this plasma afterglow system. The species flowing out of the N2-O2 discharge can be divided into two groups, depending on the time elapsed after they left the discharge zone as they move toward the chamber, namely the early afterglow and the late afterglow. The early flowing afterglow from a pure N2 discharge (also called pink afterglow) is known to be comprised of N2+ and N4+ ions. In the present N2-O2 mixture discharge, NO+ ions are additionally generated, with a lifetime that extends over a longer period than that of the nitrogen molecular ions. We shall suppose that the disappearance of the NO+ ions marks the end of the early afterglow regime, thereby stressing our intent

  11. THE CYTOKINES SYNTHESIS IN VITRO IN THE TICK-BORNE ENCEPHALITIS VIRUS INFECTED CELLS AND IN THE PRESENCE OF INACTIVATED VACCINE

    Directory of Open Access Journals (Sweden)

    M. V. Mesentseva

    2014-01-01

    Full Text Available Abstract. Tick-borne encephalitis (TBE is severe neuroinfectious disease with involvement of immune mechanisms in pathogenesis. Comparative analysis of synthesis of key cytokines had been performed for the TBE virus (TBEV infected cells and in the presence of inactivated vaccine against TBE in vitro. Persistent TBEV infection of immortal tissue culture of human larynx cancer cells caused transcription activation of interferons IFNα, IFNγ, IFNλ1, interleukins IL-1β, IL-2, IL-4, IL-8, IL-10, IL-12, tumour necrosis factor TNFα as well as one of apoptosis factors Fas. Comparison of transcription and production of cytokines revealed that the TBEV infection resulted in posttranscription Th1 shift of cytokine response. In the presence of inactivated vaccine against TBE based on the same strain Sofjin of the TBEV activation of transcription of cytokines IFNα, IFNλ1, IL-4, IL-10 was also observed as after the TBEV infection that together with an additional stimulation of GM-CSF production might serve as an evidence of Th2 response. Involvement of IFNIII type (IFNλ1 both during persistent infection and after addition of inactivated vaccines was found in the first time. Differences in dynamics of cytokines IL-2, IL-8, IL-10, IL-12, TNFα response during the TBEV infection and in the presence of inactivated vaccine are described.

  12. Inactivation of viruses in platelet suspensions that retain their in vitro characteristics: Comparison of psoralen-ultraviolet A and merocyanine 540-visible light methods

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, R.Y.; Moroff, G.; Wagner, S.; Dabay, M.H.; Dorfman, E.; George, V.; Ribeiro, A.; Shumaker, J.; Benade, L.E. (Jerome H. Holland Laboratory, American Red Cross, Rockville, MD (USA))

    1991-07-01

    The ability of two fundamentally different photochemical procedures to inactivate model viruses in platelet suspensions was compared. Merocyanine 540 (MC 540) with visible light was used as an example of an oxygen-dependent chemical-directed at the viral membrane, and aminomethyl trimethyl psoralen (AMT) with ultraviolet A light (UVA) was used as an example of a nucleic acid-directed system. Antiviral conditions in petri dishes were identified and the effects of these procedures on platelet suspensions in plastic storage containers were studied. Concentrations of photochemicals in the 10 to 150 mumol range with 30 to 60 minutes of visible light (MC 540) or 1 to 2 minutes of UVA (AMT) readily inactivated 5 to 6 log10 of vesicular stomatitis virus (VSV) and other model viruses in platelet suspensions, provided the plasma concentration was reduced to about 15 percent by the use of a synthetic platelet storage medium. Extracellular pH, morphology scores, and aggregation response dropped markedly when platelets were treated with MC 540 and visible light. However, treatment with 136 mumol per L of AMT and 1 to 3 minutes of UVA could inactivate 5 log10 of VSV in platelet suspensions with retention of platelet characteristics for 4 days, particularly if oxygen levels were reduced during treatment. These studies demonstrate that AMT-UVA treatment meets the initial requirements for virus inactivation in platelet suspensions.

  13. Inactivated probiotic Bacillus coagulans GBI-30 induces complex immune activating, anti-inflammatory, and regenerative markers in vitro

    National Research Council Canada - National Science Library

    Jensen GS; Cash HA; Farmer S; Keller D

    2017-01-01

    ...., Landerbrook Drive Suite, Mayfield Heights, OH, USA Objective: The aim of this study was to document the immune activating and anti-inflammatory effects of inactivated probiotic Bacillus coagulans GBI-30, 6086 (Staimune...

  14. Spray-dried plasma and fresh frozen plasma modulate permeability and inflammation in vitro in vascular endothelial cells.

    Science.gov (United States)

    Wataha, K; Menge, T; Deng, X; Shah, A; Bode, A; Holcomb, J B; Potter, D; Kozar, R; Spinella, P C; Pati, S

    2013-01-01

    After major traumatic injury, patients often require multiple transfusions of fresh frozen plasma (FFP) to correct coagulopathy and to reduce bleeding. A spray-dried plasma (SDP) product has several logistical benefits over FFP use in trauma patients with coagulopathy. These benefits include ease of transport, stability at room temperature, and rapid reconstitution for infusion. Our past work suggests that FFP promotes endothelial stability by inhibiting endothelial permeability. The main goal of this project is to determine if solvent-detergent-treated SDP is equivalent to FFP in inhibiting vascular endothelial cell (EC) permeability and inflammation in vitro. Furthermore, this study aimed to determine if solvent-detergent treatment and spray drying of plasma alters the protective effects of FFP on EC function. The five groups tested in our studies are the following: 1) fresh frozen-thawed plasma (FFP); 2) solvent-detergent-treated FFP; 3) solvent-detergent-treated SDP; 4) lactated Ringer's solution; and 5) Hextend. This study demonstrates that in vitro SDP and FFP equivalently inhibit vascular EC permeability, EC adherens junction breakdown, and endothelial white blood cell binding, an effect that is independent of changes in Vascular Cell Adhesion Molecule 1, Intracellular Adhesion Molecule 1, or E-selectin expression on ECs. Solvent-detergent treatment of FFP does not alter the protective effects of FFP on endothelial cell function in vitro. These data suggest the equivalence of FFP and SDP on modulation of endothelial function and inflammation in vitro. © 2013 American Association of Blood Banks.

  15. Gene Inactivation in the Cyanobacterium Synechococcus sp. PCC 7002 and the Green Sulfur Bacterium Chlorobium tepidum Using In Vitro-Made DNA Constructs and Natural Transformation

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Sakuragi, Yumiko; Bryant, Donald A

    2004-01-01

    Inactivation of a chromosomal gene is a useful approach to study the function of the gene in question and can be used to produce a desired phenotype in the organism. This chapter describes how to generate such mutants of the cyanobacterium Synechococcus sp. PCC 7002 and the green sulfur bacterium...... Chlorobium tepidum by natural transformation with synthetic DNA constructs. Two alternative methods to generate the DNA constructs, both performed entirely in vitro and based on the polymerase chain reaction (PCR), are also presented. These methods are ligation of DNA fragments with T4 DNA ligase...

  16. Haemovigilance data on the use of methylene blue virally inactivated fresh frozen plasma with the Theraflex MB-Plasma System in comparison to quarantine plasma: 11 years' experience.

    Science.gov (United States)

    Politis, C; Kavallierou, L; Hantziara, S; Parara, M; Zervou, E; Katsarou, O; Hatzitaki, M; Fountouli, P; Gioka, A; Tzioura, K; Koumarianos, S; Asariotou, M; Richardson, C

    2014-10-01

    Haemovigilance is an effective tool for identifying adverse effects of blood components. We analyse cumulative haemovigilance data in order to compare the two secured therapeutic plasmas that have been in use for more than 11 years in Greece - methylene blue-treated fresh frozen plasma (MB-FFP) and quarantine fresh frozen plasma (Q-FFP) - regarding safety and adverse events. Data from the centralised active haemovigilance system of Greece for the period 2001-2011 were used to examine the association between FFP types and adverse events. Post-transfusion information on infectious and non-infectious adverse events was analysed. Events were examined by reaction type, severity and imputability to transfusion. The incidence of adverse events was higher with Q-FFP (1:3620) than MB-FFP (1 : 24 593) by a factor of 6·79 [95% confidence interval (CI) 2·52-27·8]. Allergic adverse events were also commoner with Q-FFP (1 : 7489) than with MB-FFP (1:24 593), by a factor of 3·28 (95% CI 1·17-13·7). All adverse reactions experienced by the MB plasma recipients were considered to be mild. Haemovigilance over 11 years has demonstrated the long-term safety of MB-FFP in comparison to untreated quarantine FFP. In addition to lowering the adverse event rate, implementing the system on a national scale in at-risk countries would presumably reduce the transmission of severe viral infections including emerging infectious diseases by transfusion. © 2014 British Blood Transfusion Society.

  17. The effective concentration of tranexamic acid for inhibition of fibrinolysis in neonatal plasma in vitro.

    Science.gov (United States)

    Yee, Branden E; Wissler, Richard N; Zanghi, Christine N; Feng, Changyong; Eaton, Michael P

    2013-10-01

    Neonates are at high risk for bleeding complications after cardiovascular surgery. Activation of intravascular fibrinolysis is one of the principal effects of cardiopulmonary bypass that causes poor postoperative hemostasis. Antifibrinolytic medications such as tranexamic acid are often used as prophylaxis against fibrinolysis, but concentration/effect data to guide dosing are sparse for adults and have not been published for neonates. Higher concentrations of tranexamic acid than those necessary for inhibition of fibrinolysis may have adverse effects. Therefore, we investigated the concentration of tranexamic acid necessary to inhibit activated fibrinolysis in neonatal plasma. We conducted an in vitro study using neonatal plasma derived from the placenta/cord units from 20 term, elective cesarean deliveries. Graded concentrations of tranexamic acid were added to aliquots of the pooled plasma before maximally activating fibrinolysis with high-dose tissue-type plasminogen activator. Thromboelastography was then performed with the primary outcome variable being lysis at 30 minutes. These procedures were repeated on pooled adult normal plasma and dilutions of neonatal plasma. The minimum concentrations of tranexamic acid to completely prevent fibrinolysis were 6.54 μg/mL (95% confidence interval, 5.19-7.91) for neonatal plasma and 17.5 μg/mL (95% confidence interval, 14.59-20.41) for adult plasma. Neonatal plasma requires a significantly lower concentration than adult plasma (P fibrinolysis in neonatal plasma in vitro. These data may be useful in designing a dosing scheme for tranexamic acid appropriate for neonates.

  18. In Vitro Studies of Interaction of Rickettsia and Macrophages: Effect of Ultraviolet Light on Coxiella burnetii Inactivation and Macrophage Enzymes

    Science.gov (United States)

    1980-03-01

    Effect of Ultraviolet Light on Coxiella burnetii Inactivation . and Macrophage Enzymes /- ( JAMES S. TTE RICHARD A.IKISH|MOTAMWXPETER.GyANON|CO V...unirtea-s- i4’fn Medical Researc’Tii-’feIflte of lnJto AM .¢fyrflrt Der’Ic iferi,.Maiyiand2,70O ) The inactivation of Coxiella burnetii in suspension or...biochemical assays were pur- intracellular fate of Coxiella burnetii in guinea chased from Koch-Light Laboratories, Ltd. pig peritoneal macrophages, it was

  19. In vitro studies of interaction of rickettsia and macrophages: effect of ultraviolet light on Coxiella burnetti inactivation and macrophage enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Little, J.S.; Kishimoto, R.A.; Canonico, P.G.

    1980-03-01

    The inactivation of Coxiella burnetii in suspension or in cultures of guinea pig peritoneal macrophages by ultraviolet (uv) light was studied. The effect of uv treatment on the activity of macrophage organelle marker enzymes and their subsequent equilibration in linear sucrose gradients was also determined. It was shown that uv treatment for 15 s at a distance of 10 cm inactivated C. burnetti, either in suspension or within guinea pig peritoneal macrophages. Similar uv treatment had little effect on the activity or equilibration of macrophage organelle marker enzymes in linear sucrose gradients.

  20. Flexible thin-layer plasma inactivation of bacteria and mold survival in beef jerky packaging and its effects on the meat's physicochemical properties.

    Science.gov (United States)

    Yong, Hae In; Lee, Haelim; Park, Sanghoo; Park, Jooyoung; Choe, Wonho; Jung, Samooel; Jo, Cheorun

    2017-01-01

    The aims of the present study were to examine the use of a flexible thin-layer plasma system in inactivating bacteria and mold on beef jerky in a commercial package and to evaluate the physicochemical changes of the jerky. After plasma treatment for 10min, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Aspergillus flavus populations on the beef jerky were reduced by approximately 2 to 3Log CFU/g. No significant changes in metmyoglobin content, shear force, and myofibrillar fragmentation index were found in the plasma-treated beef jerky. On the other hand, the peroxide content and L ⁎ value were decreased whereas the a ⁎ and ΔE value were increased in the plasma-treated sample. Sensory evaluation indicated negative effects of plasma treatment on flavor, off-odor, and overall acceptability of the beef jerky. In conclusion, the flexible thin-layer plasma system could be employed as a means for decontamination of beef jerky, with slight changes to the physicochemical quality of the product. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Synergy effect of heat and UV photons on bacterial-spore inactivation in an N{sub 2}-O{sub 2} plasma-afterglow sterilizer

    Energy Technology Data Exchange (ETDEWEB)

    Boudam, M K; Moisan, M, E-mail: michel.moisan@umontreal.c [Groupe de Physique des Plasmas, Universite de Montreal, C.P. 6128, Succursale Centre-Ville, Montreal H3C 3J7, Quebec (Canada)

    2010-07-28

    As a rule, medical devices (MDs) made entirely from metals and ceramics can withstand, for sterilization purposes, elevated temperatures such as those encountered in autoclaves (moist heat {>=}120 {sup 0}C) or Poupinel (Pasteur) ovens (dry heat {>=}160 {sup 0}C). This not the case with MDs containing polymers: 70 {sup 0}C seems to be a limit beyond which their structural and functional integrity will be compromised. Nonetheless, all the so-called low-temperature sterilization techniques, relying essentially on some biocidal chemistry (e.g. ethylene oxide, H{sub 2}O{sub 2}, O{sub 3}), are operated at temperatures close to 65 {sup 0}C, essentially to enhance the chemical reactivity of the biocidal agent. Based on this fact, we have examined the influence of increasing the temperature of the polystyrene Petri dish containing B. atrophaeus bacterial spores when exposing them to UV radiation coming from an N{sub 2}-O{sub 2} flowing plasma afterglow. We have observed that, for a given UV radiation intensity, the inactivation rate increases with the temperature of the Petri dish, provided heat and UV photons are applied simultaneously, a clear case of synergistic effect. More specifically, it means that (i) simply heating the spores at temperatures below 65 {sup 0}C without irradiating them with UV photons does not induce mortality; (ii) there is no additional increase in the inactivation rate when the Petri has been pre-heated and then brought back to ambient temperature before the spores are UV irradiated; (iii) no additional inactivation results from post-heating spores previously inactivated with UV radiation. Undoubtedly, the synergistic effect shows up only when the physico-chemical agents (UV photons and temperature) are simultaneously in action.

  2. In vitro inactivation of two Egyptian A/H5N1 viruses by four commercial chemical disinfectants.

    Science.gov (United States)

    Marzouk, Eman; Abd El-Hamid, Hatem S; Awad, Ashraf M; Zessin, Karl-Hans; Abdelwhab, E M; Hafez, Hafez M

    2014-09-01

    The highly pathogenic H5N1 avian influenza virus (A/H5N1) devastated the poultry industry and posed a serious health threat. Cleaning and disinfection are essential parts of preventative and postoutbreak management of A/H5N1 infections in poultry. In this preliminary study, we used suspension and carrier tests to evaluate the impact of concentration, time of exposure, surface porosity, and organic matter on the ability of four commercial chemical disinfectants to inactivate two A/H5N1 viruses of clade 2.2.1 isolated in 2006 and 2010 from broiler flocks in Egypt. Viruses were incubated with 0.5%, 1%, and 2% of formalin, glutaraldehyde, TH4, and Virkon S for 15, 30, 60, and 120 min at room temperature (22 +/- 2 C). In suspension tests, in the absence of organic matter, all disinfectants, at each concentration, except Virkon S 0.5%, effectively inactivated virus suspensions after a 15-min exposure time. In the presence of organic matter, the use of low concentrations of formalin (0.5%), glutaraldehyde (0.5%), or Virkon S (0.5%) was not sufficient to inactivate the viruses after 15 min. In gauze carrier tests, only formalin at any concentration for 15 min was sufficient to inactivate the viruses, whereas different concentrations or exposure times were required for glutaraldehyde (0.5% for 60 min), TH4 (0.5% for 30 min), and Virkon S (0.5% for 60 min or 1% for 30 min). In wood carrier tests, total inactivation of the virus was obtained at concentrations of 0.5% for 30 min (formalin and TH4) or 60 min (glutaraldehyde and Virkon S). This study emphasizes the need to use high concentrations of and/or extended time of exposure to disinfectants for efficient inactivation of A/H5N1, particularly in the presence of organic matter or different surfaces, which are common in poultry operations. In addition, it seemed that the virus isolated in 2010 was more resistant to disinfectants than the isolate from 2006 when wood was used as a carrier.

  3. Size of the plasma membrane H+-ATPase from Neurospora crassa determined by radiation inactivation and comparison with the sarcoplasmic reticulum Ca2+-ATPase from skeletal muscle.

    Science.gov (United States)

    Bowman, B J; Berenski, C J; Jung, C Y

    1985-07-25

    Using radiation inactivation, we have measured the size of the H+-ATPase in Neurospora crassa plasma membranes. Membranes were exposed to either high energy electrons from a Van de Graaff generator or to gamma irradiation from 60Co. Both forms of radiation caused an exponential loss of ATPase activity in parallel with the physical destruction of the Mr = 104,000 polypeptide of which this enzyme is composed. By applying target theory, the size of the H+-ATPase in situ was found to be approximately 2.3 X 10(5) daltons. We also used radiation inactivation to measure the size of the Ca2+-ATPase of sarcoplasmic reticulum and got a value of approximately 2.4 X 10(5) daltons, in agreement with previous reports. By irradiating a mixture of Neurospora plasma membranes and rabbit sarcoplasmic reticulum, we directly compared the sizes of these two ATPases and found them to be essentially the same. We conclude that both H+-ATPase and Ca2+-ATPase are oligomeric enzymes, most likely composed of two approximately 100,000-dalton polypeptides.

  4. Influence of iodinated contrast media on the activities of histamine inactivating enzymes diamine oxidase and histamine N-methyltransferase in vitro.

    Science.gov (United States)

    Kuefner, M A; Feurle, J; Petersen, J; Uder, M; Schwelberger, H G

    2014-01-01

    Iodinated contrast media can cause pseudoallergic reactions associated with histamine release in significant numbers of patients. To clarify whether these adverse reactions may be aggravated by a compromised histamine catabolism we asked if radiographic contrast agents in vitro inhibit the histamine inactivating enzymes diamine oxidase (DAO) and histamine N-methyltransferase (HMT). Nine iodinated contrast agents were tested in vitro. Following pre-incubation of purified porcine kidney DAO and recombinant human HMT with 0.1-10mM of the respective contrast medium (H2O and specific inhibitors of DAO and HMT as controls) enzyme activities were determined by using radiometric micro assays. None of the contrast media irrespective of their structure showed significant inhibition of the activities of DAO and HMT. Pre-incubation of the enzymes with specific inhibitors led to complete inhibition of the respective enzymatic activity. The iodinated contrast media tested in vitro did not exhibit inhibition of histamine converting enzymes at physiologically relevant concentrations. However due to the in vitro character of this study these results do not directly reflect the in vivo situation. Copyright © 2012 SEICAP. Published by Elsevier Espana. All rights reserved.

  5. Synergistic Effects of Nonthermal Plasma and Disinfecting Agents against Dental Biofilms In Vitro

    OpenAIRE

    Koban, Ina; Geisel, Marie Henrike; Holtfreter, Birte; Jablonowski, Lukasz; H?bner, Nils-Olaf; Matthes, Rutger; Masur, Kai; Weltmann, Klaus-Dieter; Kramer, Axel; Kocher, Thomas

    2013-01-01

    Aim. Dental biofilms play a major role in the pathogenesis of many dental diseases. In this study, we evaluated the synergistic effect of atmospheric pressure plasma and different agents in dentistry on the reduction of biofilms. Methods and Results. We used monospecies (S. mutans) and multispecies dental biofilm models grown on titanium discs in vitro. After treatment with one of the agents, the biofilms were treated with plasma. Efficacy of treatment was determined by the number of colony f...

  6. In Vitro Antimicrobial Effect of a Cold Plasma Jet against Enterococcus faecalis Biofilms

    OpenAIRE

    Chunqi Jiang; Christoph Schaudinn; Jaramillo, David E.; Paul Webster; J. William Costerton

    2012-01-01

    The hypothesis that a cold plasma jet has the antimicrobial effect against Enterococcus faecalis biofilms was tested in vitro. 27 hydroxyapatite discs were incubated with E. faecalis for six days to form a monoculture biofilm on the disc surface. The prepared substrata were divided into three groups: the negative control, the positive control (5.25% NaOCl solution), and the plasma treatment group. Resultant colony-forming unit counts were associated with observations of bacterial cell morphol...

  7. In vitro corrosion investigations of plasma-sprayed hydroxyapatite ...

    Indian Academy of Sciences (India)

    The present paper discusses various issues associated with biological corrosion of uncoated and plasma-sprayed hydroxyapatite (HA)-coated 316L SS and studies the effect of contents of calcium phosphate (CaP) on corrosion behaviour of hydroxyapatite (HA) coatings in simulated body fluid (Ringer's solution).

  8. Plasma of pregnant and preeclamptic women activates monocytes in vitro

    NARCIS (Netherlands)

    Faas, M.M.; Donker, R.B.; van Pampus, M.G.; Huls, A.M.; Salomons, J.; de Vos, P.; Aarnoudse, J.G.

    OBJECTIVE: The objective of the study was to test the hypothesis that factors circulating in the plasma of pregnant women and women with preeclampsia activate monocytes. STUDY DESIGN: Blood samples were taken from patients with early-onset severe preeclampsia (n = 9), healthy pregnant women (n = 9),

  9. In vitro corrosion investigations of plasma-sprayed hydroxyapatite ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. The present paper discusses various issues associated with biological corrosion of uncoated and plasma-sprayed hydroxyapatite (HA)-coated 316L SS and studies the effect of contents of calcium phosphate. (CaP) on corrosion behaviour of hydroxyapatite (HA) coatings in simulated body fluid (Ringer's solution).

  10. Ca(2+)-independent fusion of secretory granules with phospholipase A2-treated plasma membranes in vitro.

    OpenAIRE

    Nagao, T.; Kubo, T.; Fujimoto, R.; Nishio, H; Takeuchi, T.; Hata, F.

    1995-01-01

    The fusion of secretory granules with plasma membranes prepared from rat parotid gland was studied in vitro to clarify the mechanism of exocytosis. Fusion of the granules with plasma membranes was measured by a fluorescence-dequenching assay with octadecyl rhodamine B, and release of amylase was also measured to confirm the fusion as a final step of the secretory process. Plasma membranes that had been pretreated with porcine phospholipase A2 (PLA2) in the presence of 20 microM Ca2+ fused wit...

  11. Steady-state plasma concentration of donepezil enantiomers and its stereoselective metabolism and transport in vitro.

    Science.gov (United States)

    Lili, Wan; Cheng, Guo; Zhiyong, Zhou; Qi, Yu; Yan, Li; Dan, Li; Xueli, Zheng; Yuan, Zhong

    2013-09-01

    The aim of the present study was to elucidate the differences in the plasma concentration of two enantiomers of donepezil in Chinese patients with Alzheimer's disease (AD) and investigate in vitro stereoselective metabolism and transport. Donepezil enantiomers were separated and determined by LC-MS/MS using D5-donepezil as an internal standard on a Sepax Chiralomix SB-5 column. In vitro stereoselective metabolism and transport of donepezil were investigated in human liver microsomes and MDCKII-MDR1 cell monolayer. Pre-dose (Css-min) plasma concentrations were determined in 52 patients. The mean plasma level of (R)-donepezil was 14.94 ng/ml and that of (S)-donepezil was 23.37 ng/ml. One patient's plasma concentration of (R)-donepezil was higher than (S)-donepezil and the ratio is 1.51. The mean plasma levels of (S)-donepezil were found to be higher than those of (R)-donepezil in 51 patients and the ratio of plasma (R)- to (S)-donepezil varies from 0.34 to 0.85. In the in vitro microsomal system, (R)-donepezil degraded faster than (S)-donepezil. V(max) of (R)-donepezil was significantly higher than (S)-donepezil. The P-gp inhibition experiment shown that the P(app) of the two enantiomers was higher than 200 and the efflux ratios were 1.11 and 0.99. The results of the P-gp inhibition identification experiment showed IC50 values of 35.5 and 20.4 μM, respectively, for the two enantiomers. The results indicate that donepezil exhibits stereoselective hepatic metabolism that may explain the differences in the steady-state plasma concentrations observed. Neither (R)- nor (S)-donepezil was a P-gp substance and the two enantiomers are highly permeable through the blood-brain barrier. © 2013 Wiley Periodicals, Inc.

  12. Packaging materials for plasma sterilization with the flowing afterglow of an N2-O2 discharge: damage assessment and inactivation efficiency of enclosed bacterial spores

    Science.gov (United States)

    Levif, P.; Séguin, J.; Moisan, M.; Soum-Glaude, A.; Barbeau, J.

    2011-10-01

    In conventional sterilization methods (steam, ozone, gaseous chemicals), after their proper cleaning, medical devices are wrapped/enclosed in adequate packaging materials, then closed/sealed before initiating the sterilization process: these packaging materials thus need to be porous. Gaseous plasma sterilization being still under development, evaluation and comparison of packaging materials have not yet been reported in the literature. To this end, we have subjected various porous packagings used with conventional sterilization systems to the N2-O2 flowing afterglow and also a non-porous one to evaluate and compare their characteristics towards the inactivation of B. atrophaeus endospores deposited on a Petri dish and enclosed in such packagings. Because the sterilization process with the N2-O2 discharge afterglow is conducted under reduced-pressure conditions, non-porous pouches can be sealed only after returning to atmospheric pressure. All the tests were therefore conducted with one end of the packaging freely opened, post-sealing being required. The features of these packaging materials, namely mass loss, resistance, toxicity to human cells as well as some characteristics specific to the plasma method used such as ultraviolet transparency, were examined before and after exposure to the flowing afterglow. All of our results show that the non-porous packaging considered is much more suitable than the conventionally used porous ones as far as ensuring an efficient and low-damage sterilization process with an N2-O2 plasma-afterglow is concerned.

  13. Determination of the functional size of oxytocin receptors in plasma membranes from mammary gland and uterine myometrium of the rat by radiation inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Soloff, M.S.; Beauregard, G.; Potier, M.

    1988-05-01

    Gel filtration of detergent-solubilized oxytocin (OT) receptors in plasma membrane fractions from both regressed mammary gland and labor myometrium of the rat, showed that specific (/sup 3/H)OT binding was associated with a heterogeneously sized population of macromolecules. As radiation inactivation is the only method available to measure the apparent molecular weights of membrane proteins in situ, we used this approach to define the functional sizes of OT receptors. The results indicate that both mammary and myometrial receptors are uniform in size and of similar molecular mass. Mammary and myometrial receptors were estimated to be 57.5 +/- 3.8 (SD) and 58.8 +/- 1.6 kilodaltons, respectively. Knowledge of the functional size of OT receptors will be useful in studies involving the purification and characterization of the receptor and associated membrane components.

  14. Potentiation of antimicrobial photodynamic inactivation mediated by a cationic fullerene by added iodide: in vitro and in vivo studies.

    Science.gov (United States)

    Zhang, Yunsong; Dai, Tianhong; Wang, Min; Vecchio, Daniela; Chiang, Long Y; Hamblin, Michael R

    2015-03-01

    Antimicrobial photodynamic inactivation with fullerenes bearing cationic charges may overcome resistant microbes. We synthesized C60-fullerene (LC16) bearing decaquaternary chain and deca-tertiary-amino groups that facilitates electron-transfer reactions via the photoexcited fullerene. Addition of the harmless salt, potassium iodide (10 mM) potentiated the ultraviolet A (UVA) or white light-mediated killing of Gram-negative bacteria Acinetobacter baumannii, Gram-positive methicillin-resistant Staphylococcus aureus and fungal yeast Candida albicans by 1-2+ logs. Mouse model infected with bioluminescent Acinetobacter baumannii gave increased loss of bioluminescence when iodide (10 mM) was combined with LC16 and UVA/white light. The mechanism may involve photoinduced electron reduction of (1)(C60>)* or (3)(C60>)* by iodide producing I· or I2 followed by subsequent intermolecular electron-transfer events of (C60>)-· to produce reactive radicals.

  15. Evaluation of silver-infused polylactide films for inactivation of Salmonella and feline calicivirus in vitro and on fresh-cut vegetables.

    Science.gov (United States)

    Martínez-Abad, A; Ocio, M J; Lagarón, J M; Sánchez, G

    2013-03-01

    There is a growing trend to develop packaging materials with an active role in guarantying that the quality and safety characteristics of packaged products will remain or improve from preparation throughout shelf-life. In the present study, 0.001-1.0 wt.% silver ions were satisfactorily incorporated into polylactide (PLA) films by a solvent casting technique. Silver migration from the films was measured by voltamperometry and then correlated with its antimicrobial efficacy against Salmonella enterica and feline calicivirus (FCV), a human norovirus surrogate, by using the Japanese industrial standard (JIS Z 2801). The PLA-silver films showed strong antibacterial and antiviral activity in vitro, with increasing effects at higher silver concentrations. Moreover, results show that FCV was less susceptible to silver than Salmonella. When films were applied on food samples, antibacterial and antiviral activity was reduced as compared to in vitro. Antimicrobial activity was very much dependent on the food type and temperature. In lettuce samples incubated at 4 °C during 6 days, 4 log CFU of Salmonella was inactivated for films with 1.0 wt.% and no infectious FCV was reported under the same conditions. On paprika samples, no antiviral effect was seen on FCV infectivity whereas films showed less antibacterial activity on Salmonella. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Impact of photodynamic inactivation (PDI) using the photosensitizer chlorin e6 on viability, apoptosis, and proliferation of human keratocytes in vitro.

    Science.gov (United States)

    Wang, Jiong; Stachon, Tanja; Eppig, Timo; Langenbucher, Achim; Seitz, Berthold; Szentmáry, Nóra

    2013-12-01

    Photodynamic inactivation (PDI) may be a potential alternative in cases of therapy-resistant infectious keratitis. The purpose of our study was to determine the impact of PDI using the photosensitizer chlorin e6 (Ce6) on viability, apoptosis, and proliferation of human keratocytes, in vitro. Primary human keratocytes were isolated by digestion in collagenase (1 mg/ml) from human corneal buttons, and cultured in DMEM/Ham's F12 medium supplemented with 10 % FCS. Keratocyte cell cultures underwent illumination using red (670 nm) light for 13 min following exposure to 50 nM to 64 μM concentrations of Ce6 in the culture medium. Twenty-four hours after PDI, cell viability was evaluated by the Alamar blue assay, total DNA content of the cells and apoptosis using the APO-DIRECT Kit, and cell proliferation by the BrdU Cell Proliferation Assay Kit. Using Ce6 or illumination only, we did not detect significant changes of cell viability, apoptosis, and proliferation. Using illumination, viability of keratocytes decreased significantly above 100 nM (P proliferation at 250 nM Ce6 concentration (P = 0.01) and the percentage of apoptotic keratocytes increased significantly at 500 nM (P proliferation, and also triggers apoptosis of human keratocytes, in vitro.

  17. Synergistic Effects of Nonthermal Plasma and Disinfecting Agents against Dental Biofilms In Vitro

    Science.gov (United States)

    Koban, Ina; Geisel, Marie Henrike; Holtfreter, Birte; Jablonowski, Lukasz; Hübner, Nils-Olaf; Matthes, Rutger; Masur, Kai; Weltmann, Klaus-Dieter; Kramer, Axel; Kocher, Thomas

    2013-01-01

    Aim. Dental biofilms play a major role in the pathogenesis of many dental diseases. In this study, we evaluated the synergistic effect of atmospheric pressure plasma and different agents in dentistry on the reduction of biofilms. Methods and Results. We used monospecies (S. mutans) and multispecies dental biofilm models grown on titanium discs in vitro. After treatment with one of the agents, the biofilms were treated with plasma. Efficacy of treatment was determined by the number of colony forming units (CFU) and by live-dead staining. For S. mutans biofilms no colonies could be detected after treatment with NaOCl or H2O2. For multispecies biofilms the combination with plasma achieved a higher CFU reduction than each agent alone. We found an additive antimicrobial effect between argon plasma and agents irrespective of the treatment order with cultivation technique. For EDTA and octenidine, antimicrobial efficacy assessed by live-dead staining differed significantly between the two treatment orders (P effective treatment of dental biofilms on titanium discs with atmospheric pressure plasma could be increased by adding agents in vitro. PMID:24159388

  18. Synergistic Effects of Nonthermal Plasma and Disinfecting Agents against Dental Biofilms In Vitro.

    Science.gov (United States)

    Koban, Ina; Geisel, Marie Henrike; Holtfreter, Birte; Jablonowski, Lukasz; Hübner, Nils-Olaf; Matthes, Rutger; Masur, Kai; Weltmann, Klaus-Dieter; Kramer, Axel; Kocher, Thomas

    2013-01-01

    Aim. Dental biofilms play a major role in the pathogenesis of many dental diseases. In this study, we evaluated the synergistic effect of atmospheric pressure plasma and different agents in dentistry on the reduction of biofilms. Methods and Results. We used monospecies (S. mutans) and multispecies dental biofilm models grown on titanium discs in vitro. After treatment with one of the agents, the biofilms were treated with plasma. Efficacy of treatment was determined by the number of colony forming units (CFU) and by live-dead staining. For S. mutans biofilms no colonies could be detected after treatment with NaOCl or H2O2. For multispecies biofilms the combination with plasma achieved a higher CFU reduction than each agent alone. We found an additive antimicrobial effect between argon plasma and agents irrespective of the treatment order with cultivation technique. For EDTA and octenidine, antimicrobial efficacy assessed by live-dead staining differed significantly between the two treatment orders (P effective treatment of dental biofilms on titanium discs with atmospheric pressure plasma could be increased by adding agents in vitro.

  19. Efficacy of Atmospheric Pressure Plasma as an Antibacterial Agent Against Enterococcus Faecalis in Vitro

    Science.gov (United States)

    Cao, Yingguang; Yang, Ping; Lu, Xinpei; Xiong, Zilan; Ye, Tao; Xiong, Qing; Sun, Ziyong

    2011-02-01

    Enterococcus faecalis (E. faecalis) is a microorganism that can survive extreme challenges in obturated root canals. The aim of this study was to evaluate the efficacy of a non-thermal atmospheric pressure plasma plume against E. faecalis in vitro. A non-thermal atmospheric pressure plasma jet device which could generate a cold plasma plume carrying a peak current of 300 mA was used. The antibacterial efficacy of this device against E. faecalis and its biofilm under different conditions was detected. The antibacterial efficacy of the plasma against E. faecalis and Staphylococcus aureus (S. aureus) was also evaluated. After plasma treatment, the average diameter of inhibition zone on S. aureus and E. faecalis was 2.62±0.26 cm and 1.06±0.30 cm, respectively (P < 0.05). The diameter was increased with prolongation of the treatment duration. The diameters of inhibition zone of the sealed Petri dishes were larger than those of the uncovered Petri dishes. There was significant difference in colony-forming units between plasma group and control group on E. faecalis biofilm (P < 0.01). The transmission electron microscopy revealed that the ultrastructural changes cytoderm of E. faecalis were observed after treatment for 2 min. It is concluded that the non-thermal atmospheric pressure plasma could serve as an effective adjunct to standard endodontic microbial treatment.

  20. Plasma-induced grafting of polydimethylsiloxane onto polyurethane surface: Characterization and in vitro assay

    Energy Technology Data Exchange (ETDEWEB)

    Shourgashti, Z. [Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Khorasani, M.T., E-mail: m.khorasani@ippi.ac.i [Biomaterials Department of Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of); Khosroshahi, S.M.E. [Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2010-09-15

    Plasma-induced grafting of polydimethylsiloxane (PDMS) onto the surface of polyurethane (PU) film. The virgin, plasma treated, and PDMS grafted PU films were characterized by means of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, water drop contact angle measurements, and scanning electron microscopy (SEM). The ATR-FTIR spectrogram of the grafted film showed the new characteristic peaks of PDMS. These grafted surfaces exhibited higher hydrophobicity and homogenous morphology. In vitro cell culture study showed that modified surfaces as well as virgin film were compatible with fibroblast cells. The formation of graft polymers combines the biostability of silicone with excellent physical and mechanical properties of PU.

  1. Roles of individual radicals generated by a submerged dielectric barrier discharge plasma reactor during Escherichia coli O157:H7 inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Muhammad Saiful Islam [Department of Food Biotechnology, University of Science and Technology, Daejeon, 305-350 (Korea, Republic of); Lee, Eun-Jung [Food Safety Research Group, Korea Food Research Institute, Seongnam-si, Gyeonggi-Do (Korea, Republic of); Kim, Yun-Ji, E-mail: yunji@kfri.re.kr [Department of Food Biotechnology, University of Science and Technology, Daejeon, 305-350 (Korea, Republic of); Food Safety Research Group, Korea Food Research Institute, Seongnam-si, Gyeonggi-Do (Korea, Republic of)

    2015-10-15

    A submerged dielectric barrier discharge plasma reactor (underwater DBD) has been used on Escherichia coli O157:H7 (ATCC 35150). Plasma treatment was carried out using clean dry air gas to investigate the individual effects of the radicals produced by underwater DBD on an E. coli O157:H7 suspension (8.0 log CFU/ml). E. coli O157:H7 was reduced by 6.0 log CFU/ml for 2 min of underwater DBD plasma treatment. Optical Emission Spectra (OES) shows that OH and NO (α, β) radicals, generated by underwater DBD along with ozone gas. E. coli O157:H7 were reduced by 2.3 log CFU/ml for 10 min of underwater DBD plasma treatment with the terephthalic acid (TA) OH radical scavenger solution, which is significantly lower (3.7 log CFU/ml) than the result obtained without using the OH radical scavenger. A maximum of 1.5 ppm of ozone gas was produced during the discharge of underwater DBD, and the obtained reduction difference in E.coli O157:H7 in presence and in absence of ozone gas was 1.68 log CFU/ml. The remainder of the 0.62 log CFU/ml reduction might be due to the effect of the NO (α, β) radicals or due to the combined effect of all the radicals produced by underwater DBD. A small amount of hydrogen peroxide was also generated but does not play any role in E. coli O157:H7 inactivation.

  2. Antimicrobial photodynamic inactivation of Staphylococcus aureus biofilms in bone specimens using methylene blue, toluidine blue ortho and malachite green: An in vitro study.

    Science.gov (United States)

    Rosa, Luciano Pereira; da Silva, Francine Cristina; Nader, Sumaia Alves; Meira, Giselle Andrade; Viana, Magda Souza

    2015-05-01

    To evaluate the in vitro effectiveness of APDI with a 660 nm laser combined with methylene blue (MB), toluidine blue ortho (TBO) and malachite green (MG) dyes to inactivate Staphylococcus aureus (ATCC 25923) biofilms in compact and cancellous bone specimens. Eighty specimens of compact and 80 of cancellous bone were contaminated with a standard suspension of the microorganism and incubated for 14 days at 37°C to form biofilms. After this period, the specimens were divided into groups (n=10) according to established treatment: PS-L- (control - no treatment); PSmb+L-, PStbo+L-, PSmg+L- (only MB, TBO or MG for 5 min in the dark); PS-L+ (only laser irradiation for 180 s); and APDImb, APDItbo and APDImg (APDI with MB, TBO or MG for 180 s). The findings were statistically analyzed by ANOVA at 5% significance levels. All experimental treatments showed significant reduction of log CFU/mL S. aureus biofilms when compared with the control group for compact and cancellous bones specimens; the APDI group's treatment was more effective. The APDI carried out for the compact specimens showed better results when compared with cancellous specimens at all times of application. For the group of compact bone, APDImg showed greater reductions in CFU/mL (4.46 log 10). In the group of cancellous bone, the greatest reductions were found in the APDImb group (3.06 log 10). APDI with methylene blue, toluidine blue ortho and malachite green dyes and a 660 nm laser proved to be effective in the inactivation of S. aureus biofilms formed in compact and cancellous bone. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Effectiveness of antimicrobial photodynamic therapy using a 660 nm laser and methyline blue dye for inactivating Staphylococcus aureus biofilms in compact and cancellous bones: An in vitro study.

    Science.gov (United States)

    Rosa, Luciano Pereira; Silva, Francine Cristina da; Nader, Sumaia Alves; Meira, Giselle Andrade; Viana, Magda Souza

    2015-06-01

    New therapeutic modalities such as antimicrobial photodynamic therapy (APDT) has been investigated in order to be a valid alternative to the treatment of infections caused by different microorganisms. This work evaluated the in vitro effectiveness of Antimicrobial Photodynamic Therapy (APDT) using 660 nm laser combined with methylene blue dye to inactivate Staphylococcus aureus (ATCC 25923) biofilms in compact and cancellous bones specimens. Eighty specimens of compact bone and 80 specimens of cancellous bone were contaminated with a standard suspension of S. aureus and incubated for 14 days at 37°C to induce the formation of biofilms. The specimens were then divided into groups (n = 10) according to the established treatment: PS-L- (control--no treatment), PS+L- (only AM for 5 min in the dark), PS-L+90 (only laser irradiation for 90 s), PS-L+180 (only laser irradiation for 180 s), PS-L+300 (only laser irradiation for 300 s), APDT90 (APDT for 90 s), APDT180 (APDT for 180 s), and APDT300 (APDT for 300 s). The findings were statistically analyzed by ANOVA 5%. All of the experimental treatments showed a significant reduction (log 10 CFU/mL) of S. aureus biofilms in compact and cancellous bones specimens compared with the control group, and the APDT group was the most effective. Compact specimens treated with APDT showed the greatest reduction in biofilms compared with cancellous specimens, regardless of length of treatment. APDT with methylene blue dye and a 660 nm laser proved to be effective in inactivating S. aureus biofilms formed in compact and cancellous bone. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Cold plasma therapy of a tooth root canal infected with enterococcus faecalis biofilms in vitro.

    Science.gov (United States)

    Pan, Jie; Sun, Ke; Liang, Yongdong; Sun, Peng; Yang, Xiaohui; Wang, Jing; Zhang, Jue; Zhu, Weidong; Fang, Jing; Becker, Kurt H

    2013-01-01

    Complete sterilization of an infected root canal is an important challenge in endodontic treatment. Traditional methods often cannot achieve high-efficiency sterilization because of the complexity of the root canal system. The objective of the study was to investigate in vitro the feasibility of using a cold plasma treatment of a root canal infected with Enterococcus faecalis biofilms. Seventy single-root teeth infected with E. faecalis biofilms were divided into 7 groups. Group 1 served as the negative control group (no treatment), and group 7 was the positive control group with teeth treated with calcium hydroxide intracanal medication for 7 days. Groups 2 to 6 included teeth treated by cold plasma for 2, 4, 6, 8, and 10 minutes, respectively. The disinfection of the E. faecalis biofilm was evaluated by colony-forming unit (CFU) counting. Scanning electron microscopy was used to evaluate the structural changes of the E. faecalis biofilm before and after plasma treatment. Confocal scanning laser microscopy was used to investigate the vitality of the microorganisms in the biofilm before and after plasma treatment. A significant decrease in the number of CFUs was observed after prolonged cold plasma treatment (based on the statistical analysis of the teeth in groups 2-6). Compared with the positive control group, cold plasma treatment of 8 or 10 minutes (groups 5 and 6) had a significantly higher antimicrobial efficacy (P faecalis death and destruction of the biofilm. The cold plasma had a high efficiency in disinfecting the E. faecalis biofilms in in vitro dental root canal treatment. Copyright © 2013 American Association of Endodontists. All rights reserved.

  5. In vitro photodynamic inactivation of plant-pathogenic fungi Colletotrichum acutatum and Colletotrichum gloeosporioides with Novel Phenothiazinium photosensitizers.

    Science.gov (United States)

    de Menezes, Henrique D; Rodrigues, Gabriela B; Teixeira, Simone de Pádua; Massola, Nelson S; Bachmann, Luciano; Wainwright, Mark; Braga, Gilberto U L

    2014-03-01

    The increasing tolerance to currently used fungicides in both clinical and agricultural areas is of great concern. The nonconventional light-based approach of antimicrobial photodynamic treatment (APDT) is a promising alternative to conventional fungicides. We evaluated the effects of APDT with four phenothiazinium derivatives (methylene blue [MB], new methylene blue N [NMBN], toluidine blue O [TBO], and the novel pentacyclic phenothiazinium photosensitizer [PS] S137) on conidia of three fungal species (Colletotrichum acutatum, Colletotrichum gloeosporioides, and Aspergillus nidulans). The efficacy of APDT with each PS was determined, initially, based on photosensitizer MICs. Additionally, the effects of APDT with two selected PSs (NMBN and S137) on survival of conidia were evaluated. The subcellular localization of the PS in C. acutatum conidia was determined. The effects of photodynamic treatments on leaves of the plant host Citrus sinensis were also investigated. APDT with S137 showed the lowest MIC. MICs for S137 were 5 μM for the three fungal species when a fluence of 25 J cm(-2) was used. APDT with NMBN (50 μM) and S137 (10 μM) resulted in a reduction in the survival of the conidia of all species of approximately 5 logs with fluences of ≥15 J cm(-2). Washing of the conidia before light exposure did not prevent photodynamic inactivation. Both NMBN and S137 accumulated in cytoplasmic structures, such as lipid bodies, of C. acutatum conidia. No damage to orange tree leaves was observed after APDT.

  6. Comparison of Conventional and Microwave Treatment on Soymilk for Inactivation of Trypsin Inhibitors and In Vitro Protein Digestibility

    Directory of Open Access Journals (Sweden)

    Brinda Harish Vagadia

    2018-01-01

    Full Text Available Soymilk is lower in calories compared to cow’s milk, since it is derived from a plant source (no cholesterol and is an excellent source of protein. Despite the beneficial factors, soymilk is considered as one of the most controversial foods in the world. It contains serine protease inhibitors which lower its nutritional value and digestibility. Processing techniques for the elimination of trypsin inhibitors and lipoxygenase, which have shorter processing time and lower production costs are required for the large-scale manufacturing of soymilk. In this study, the suitable conditions of time and temperature are optimized during microwave processing to obtain soymilk with maximum digestibility with inactivation of trypsin inhibitors, in comparison to the conventional thermal treatment. The microwave processing conditions at a frequency of 2.45 GHz and temperatures of 70 °C, 85 °C and 100 °C for 2, 5 and 8 min were investigated and were compared to conventional thermal treatments at the same temperature for 10, 20 and 30 min. Response surface methodology is used to design and optimize the experimental conditions. Thermal processing was able to increase digestibility by 7% (microwave and 11% (conventional compared to control, while trypsin inhibitor activity reduced to 1% in microwave processing and 3% in conventional thermal treatment when compared to 10% in raw soybean.

  7. Potassium Iodide Potentiates Antimicrobial Photodynamic Inactivation Mediated by Rose Bengal in In Vitro and In Vivo Studies.

    Science.gov (United States)

    Wen, Xiang; Zhang, Xiaoshen; Szewczyk, Grzegorz; El-Hussein, Ahmed; Huang, Ying-Ying; Sarna, Tadeusz; Hamblin, Michael R

    2017-07-01

    Rose bengal (RB) is a halogenated xanthene dye that has been used to mediate antimicrobial photodynamic inactivation for several years. While RB is highly active against Gram-positive bacteria, it is largely inactive in killing Gram-negative bacteria. We have discovered that addition of the nontoxic salt potassium iodide (100 mM) potentiates green light (540-nm)-mediated killing by up to 6 extra logs with the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, the Gram-positive bacterium methicillin-resistant Staphylococcus aureus, and the fungal yeast Candida albicans The mechanism is proposed to be singlet oxygen addition to iodide anion to form peroxyiodide, which decomposes into radicals and, finally, forms hydrogen peroxide and molecular iodine. The effects of these different bactericidal species can be teased apart by comparing the levels of killing achieved in three different scenarios: (i) cells, RB, and KI are mixed together and then illuminated with green light; (ii) cells and RB are centrifuged, and then KI is added and the mixture is illuminated with green light; and (iii) RB and KI are illuminated with green light, and then cells are added after illumination with the light. We also showed that KI could potentiate RB photodynamic therapy in a mouse model of skin abrasions infected with bioluminescent P. aeruginosa. Copyright © 2017 American Society for Microbiology.

  8. Effects of platelet-rich plasma in a model of bovine endometrial inflammation in vitro

    OpenAIRE

    Marini, M G; C.; Perrini; Esposti, P.; Corradetti, B.; Bizzaro, D.; Riccaboni, P.; Fantinato, E.; Urbani, G.; Gelati, G.; Cremonesi, F.; Lange-Consiglio, A.

    2016-01-01

    Background Endometritis reduces fertility and is responsible for major economic losses in beef and dairy industries. The aim of this study was to evaluate an alternative therapy using platelet-rich plasma (PRP). PRP was tested in vivo, after bovine intrauterine administration, and in vitro on endometrial cells. Methods Bovine endometrial cells were cultured until passage (P) 10 with 5?% or 10?% PRP. Effect of PRP on endometrial cell proliferation and on the expression of genes [prostaglandin-...

  9. A single-center prospective study on the safety of plasma exchange procedures using a double-viral-inactivated and prion-reduced solvent/detergent fresh-frozen plasma as the replacement fluid in the treatment of thrombotic microangiopathy.

    Science.gov (United States)

    Vendramin, Chiara; McGuckin, Siobhan; Alwan, Ferras; Westwood, John-Paul; Thomas, Mari; Scully, Marie

    2017-01-01

    Patients presenting with acute episodes of thrombotic microangiopathies (TMAs) require urgent access to plasma exchange (PEX). OctaplasLG, a solvent/detergent fresh-frozen plasma product that has undergone viral inactivation and prion reduction step, has been used in our institution since 2013, replacing Octaplas. We prospectively reviewed 981 PEX procedures where OctaplasLG was the replacement fluid in 90 patients admitted acutely with a TMA presentation within our institution from January 1, 2013, to December 31, 2015. We recorded citrate toxicities, plasma reactions, viral transfer, complications related to central venous catheter, and venous thrombotic events (VTEs). Citrate toxicities were 5.4%, plasma reactions were 2%, and all were classified as Grade 1 or 2. VTE had an incidence of 12.2%, although 50% of the episodes occurred in early remission when patients were not receiving PEX. No line insertions complications were recorded. Line-associated infections were 2.2%. Hepatitis B and C serology and human immunodeficiency virus (HIV) were checked on admission. There were four patients who may have had passive transient transfer of hepatitis B antibodies from pooled plasma. No hepatitis C or HIV viral transfer was documented after treatment and no seroconversion was detected after treatment. Our data have demonstrated that the incidence of complications during PEX is low and using OctaplasLG is comparable to the low incidence of reactions. No cases of anaphylaxis, transfusion-related acute lung injury, or fatal plasma reactions were seen. There was no evidence of viral transmission or seroconversion after treatment. © 2016 AABB.

  10. Development of TiO2 powder-coated food packaging film and its ability to inactivate Escherichia coli in vitro and in actual tests.

    Science.gov (United States)

    Chawengkijwanich, Chamorn; Hayata, Yasuyoshi

    2008-04-30

    Titanium dioxide (TiO2) has attracted a great deal of attention as a photocatalytic disinfecting material in the food and environmental industry. TiO2 has been used to inactivate a wide variety of microorganisms in many applications. In the present study, we aimed to develop a TiO2 powder-coated packaging film and clarify its ability to inactivate Escherichia coli both in vitro and in actual tests, using two different particle sizes and two types of illumination at different intensities. No inhibition effect of the testing method itself on the growth of E. coli was observed. The cells of E. coli were found to have decreased 3 log CFU/ml after 180 min of illumination by two 20 W black-light bulbs (wavelength of 300-400 nm) on TiO2-coated oriented-polypropylene (OPP) film, while E. coli decreased 1 log CFU/m with black-light illumination of uncoated OPP film. The results showed that both ultraviolet A (UVA; wavelength of 315-400 nm) alone and TiO2-coated OPP film combined with UVA reduced the number of E. coli cell in vitro, but that the reduction of E. coli cell numbers was greater by TiO2-coated OPP film combined with UVA. The antimicrobial effect of TiO2-coated film is dependent on the UVA light intensity (0, TiO2 coating on the surface of OPP film. The surviving cell numbers of E. coli on TiO2-coated film decreased 3 log and 0.35 log CFU/ml after 180 min of illumination by two 20 W black bulbs and two 20 W daylight fluorescent bulbs, respectively. Despite the lesser efficacy of the photocatalytic method with fluorescent lights, the survival of E. coli cells using this method was 50% of that using fluorescent lights alone. In the actual test, the number of E. coli cells from cut lettuce stored in a TiO2-coated film bag irradiated with UVA light decreased from 6.4 on Day 0 to 4.9 log CFU/g on Day 1, while that of an uncoated film bag irradiated with UVA light decreased from 6.4 to 6.1 log CFU/g after 1 day of storage. The result shows that the TiO2-coated film

  11. In vitro combinations of red blood cell, plasma and platelet components evaluated by thromboelastography.

    Science.gov (United States)

    Agren, Anna; Edgren, Gustaf; Kardell, Malin; Ostlund, Anders; Wikman, Agneta Taune

    2014-10-01

    Thromboelastography is increasingly used to evaluate coagulation in massively bleeding patients. The aim of this study was to investigate how different combinations of blood components affect in vitro whole blood clotting measured by thromboelastography. Packed red blood cells, plasma and platelets from fresh and old blood components were mixed in vitro, in proportions of 4:4:1, 5:5:2, 8:4:1 and 2:1:0, and analysed with thromboelastography. For the ratio 4:4:1 the experiment was done at both 37 °C and 32 °C. Thromboelastography curves were within normal reference values for the blood component proportions of 4:4:1 and 5:5:2. For 8:4:1, the angle and maximal amplitude were reduced below normal values, indicating low levels of fibrinogen and/or platelets. For the 2:1:0 proportion, all parameters were affected resulting in severely impaired in vitro clot formation. The reaction-time, reflecting the coagulation factor-dependent, initial clot formation, was slightly increased at a low temperature. Prolonged storage of the components did not affect the curve. With the introduction of guidelines on the management of massive bleeding it is important to have tools for the assessment of the new protocols. In vitro evaluation of mixtures of packed red blood cells, plasma and platelets by thromboelastography may be relevant in the prediction of in vivo clot formation and haemostasis.

  12. Susceptibility of Candida albicans, Staphylococcus aureus, and Streptococcus mutans biofilms to photodynamic inactivation: an in vitro study.

    Science.gov (United States)

    Pereira, Cristiane Aparecida; Romeiro, Rogério Lima; Costa, Anna Carolina Borges Pereira; Machado, Ana Karina Silva; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso

    2011-05-01

    The purpose of this study was to evaluate specific effects of photodynamic inactivation (PDI) using methylene blue as photosensitizer and low-power laser irradiation on the viability of single-, dual-, and three-species biofilms formed by C. albicans, S. aureus, and S. mutans. Biofilms were grown in acrylic discs immersed in sterile brain heart infusion broth (BHI) containing 5% sucrose, inoculated with microbial suspension (10(6) cells/ml) and incubated for 5 days. On the fifth day, the effects of the methylene blue (MB) photosensitizer at a concentration of 0.1 mg/ml for 5 min and InGaAlP laser (660 nm) for 98 s, alone and conjugated were evaluated. Next, the discs were placed in tubes with sterile physiological solution [0.9% sodium chloride (NaCl)] and sonicated for to disperse the biofilms. Ten-fold serial dilutions were carried and aliquots seeded in selective agar, which were then incubated for 48 h. Then the numbers CFU/ml (log(10)) were counted and analyzed statistically (ANOVA, Tukey test, p < 0.05). Scanning electron microscopy (SEM) on discs treated with PDI and control biofilms groups was performed. Significant decreases in the viability of all microorganisms were observed for biofilms exposed to PDI mediated by MB dye. Reductions (log(10)) of single-species biofilms were greater (2.32-3.29) than the association of biofilms (1.00-2.44). Scanning electron microscopy micrographs suggested that lethal photosensitization occurred predominantly in the outermost layers of the biofilms. The results showed that PDI mediated by MB dye, might be a useful approach for the control of oral biofilms.

  13. Combined Effects of Long-Living Chemical Species during Microbial Inactivation Using Atmospheric Plasma-Treated Water▿

    OpenAIRE

    Naïtali, Murielle; Kamgang-Youbi, Georges; Herry, Jean-Marie; Bellon-Fontaine, Marie-Noëlle; Brisset, Jean-Louis

    2010-01-01

    Electrical discharges in humid air at atmospheric pressure (nonthermal quenched plasma) generate long-lived chemical species in water that are efficient for microbial decontamination. The major role of nitrites was evidenced together with a synergistic effect of nitrates and H2O2 and matching acidification. Other possible active compounds are considered, e.g., peroxynitrous acid.

  14. Combined Effects of Long-Living Chemical Species during Microbial Inactivation Using Atmospheric Plasma-Treated Water▿

    Science.gov (United States)

    Naïtali, Murielle; Kamgang-Youbi, Georges; Herry, Jean-Marie; Bellon-Fontaine, Marie-Noëlle; Brisset, Jean-Louis

    2010-01-01

    Electrical discharges in humid air at atmospheric pressure (nonthermal quenched plasma) generate long-lived chemical species in water that are efficient for microbial decontamination. The major role of nitrites was evidenced together with a synergistic effect of nitrates and H2O2 and matching acidification. Other possible active compounds are considered, e.g., peroxynitrous acid. PMID:20889799

  15. Cold atmospheric pressure plasma treatment of ready-to-eat meat: Inactivation of Listeria innocua and changes in product quality

    DEFF Research Database (Denmark)

    Rød, Sara Katrine; Hansen, Flemming; Leipold, Frank

    2012-01-01

    The application of cold atmospheric pressure plasma for decontamination of a sliced ready-to-eat (RTE) meat product (bresaola) inoculated with Listeria innocua was investigated. Inoculated samples were treated at 15.5, 31, and 62 W for 2–60 s inside sealed linear-low-density-polyethylene bags...

  16. Flow Cytometry Assessment of In Vitro Generated CD138+ Human Plasma Cells

    Directory of Open Access Journals (Sweden)

    Rayelle Itoua Maïga

    2014-01-01

    Full Text Available The in vitro CD40-CD154 interaction promotes human B lymphocytes differentiation into plasma cells. Currently, CD138 is the hallmark marker enabling the detection of human plasma cells, both in vitro and in vivo; its presence can be monitored by flow cytometry using a specific antibody. We have developed a culture system allowing for the differentiation of memory B lymphocytes. In order to detect the newly formed plasma cells, we have compared their staining using five anti-CD138 monoclonal antibodies (mAbs. As a reference, we also tested human cell lines, peripheral blood mononuclear cells, and bone marrow samples. The five anti-CD138 mAbs stained RPMI-8226 cells (>98% with variable stain index (SI. The highest SI was obtained with B-A38 mAb while the lowest SI was obtained with DL-101 and 1D4 mAbs. However, the anti-CD138 mAbs were not showing equivalent CD138+ cells frequencies within the generated plasma cells. B-A38, B-B4, and MI-15 were similar (15–25% while DL-101 mAb stained a higher proportion of CD138-positive cells (38–42%. DL-101 and B-A38 mAbs stained similar populations in bone marrow samples but differed in their capacity to bind to CD138high and CD138lo cell lines. In conclusion, such cellular fluctuations suggest heterogeneity in human plasma cell populations and/or in CD138 molecules.

  17. Ca(2+)-independent fusion of secretory granules with phospholipase A2-treated plasma membranes in vitro.

    Science.gov (United States)

    Nagao, T; Kubo, T; Fujimoto, R; Nishio, H; Takeuchi, T; Hata, F

    1995-04-15

    The fusion of secretory granules with plasma membranes prepared from rat parotid gland was studied in vitro to clarify the mechanism of exocytosis. Fusion of the granules with plasma membranes was measured by a fluorescence-dequenching assay with octadecyl rhodamine B, and release of amylase was also measured to confirm the fusion as a final step of the secretory process. Plasma membranes that had been pretreated with porcine phospholipase A2 (PLA2) in the presence of 20 microM Ca2+ fused with the granules within 30 s, and induced amylase release by reacting with the membranes of granules, whereas without this pretreatment they had no significant effect. The fusion process accompanied by amylase release was induced in the presence of 10 mM EGTA, and therefore was apparently Ca(2+)-independent. On the other hand, the presence of EGTA or 100 microM quinacrine, an inhibitor of PLA2, during treatment of plasma membranes with PLA2 inhibited their fusogenic activity, suggesting the importance of activation of PLA2. Arachidonic acid and linoleic acid were released from the plasma membranes during the PLA2 treatment. The presence of albumin, an adsorbent of fatty acids, during the treatment also inhibited the activity. Pretreatment of the membranes with arachidonic acid or linoleic acid did not have any effect, but the presence of exogenously added arachidonic acid during PLA2 treatment enhanced the membrane-fusion-inducing effect of PLA2. Pretreatment of the membranes with lysophosphatidylcholine induced fusogenic activity. These findings suggest that the conformational change in the plasma-membrane phospholipids induced by PLA2 and the presence of arachidonic acid or linoleic acid produced by PLA2 are important in the process of fusion of secretory granules with the plasma membranes of rat parotid acinar cells and that the fusion process itself is independent of Ca2+.

  18. In Vitro Studies with Modoc Virus in Vero Cells: Plaque Assay and Kinetics of Growth, Neutralization, and Thermal Inactivation

    Science.gov (United States)

    Davis, James W.; Hardy, James L.

    1973-01-01

    A sensitive and quantitative assay system is described for plaquing Modoc virus in Vero cells. Neutralizing antibodies to Modoc virus could be detected by using this in vitro system by their interference with viral plaque formation. Virus was readily neutralized within 30 min at 37 C by a 1:10 dilution of hyperimmune hamster serum. The rate of neutralization and the total amount of virus neutralized was not altered significantly by the addition of 20 U of guinea pig complement to the hyperimmune hamster serum. A study of the growth of Modoc virus in Vero cells is also presented. After an initial latent period of 20 h, viral titer increased exponentially for 20 h. By 83 h after infection, 8,000 plaque-forming units of virus were detected per cell. The stability of viral infectivity in phosphate-buffered saline at pH 7.4 was evaluated. No reduction in viral titer was detected after 3 days at 7 or 22 C. A continuous decrease in infectivity at 37 C was observed, however, throughout the observation period. PMID:4201641

  19. Graptopetalum paraguayense ameliorates chemical-induced rat hepatic fibrosis in vivo and inactivates stellate cells and Kupffer cells in vitro.

    Directory of Open Access Journals (Sweden)

    Li-Jen Su

    Full Text Available BACKGROUND: Graptopetalum paraguayense (GP is a folk herbal medicine with hepatoprotective effects that is used in Taiwan. The aim of this study was to evaluate the hepatoprotective and antifibrotic effects of GP on experimental hepatic fibrosis in both dimethylnitrosamine (DMN- and carbon tetrachloride (CCl(4-induced liver injury rats. METHODS: Hepatic fibrosis-induced rats were fed with the methanolic extract of GP (MGP by oral administration every day. Immunohistochemistry, biochemical assays, and Western blot analysis were performed. The effects of MGP on the expression of fibrotic markers and cytokines in the primary cultured hepatic stellate cells (HSCs and Kupffer cells, respectively, were evaluated. RESULTS: Oral administration of MGP significantly alleviated DMN- or CCl(4-induced liver inflammation and fibrosis. High levels of alanine transaminase, aspartate transaminase, bilirubin, prothrombin activity and mortality rates also decreased in rats treated with MGP. There were significantly decreased hydroxyproline levels in therapeutic rats compared with those of the liver-damaged rats. Collagen I and alpha smooth muscle actin (α-SMA expression were all reduced by incubation with MGP in primary cultured rat HSCs. Furthermore, MGP induced apoptotic cell death in activated HSCs. MGP also suppressed lipopolysaccharide-stimulated rat Kupffer cell activation by decreasing nitric oxide, tumor necrosis factor-α and interleukin-6 production, and increasing interleukin-10 expression. CONCLUSIONS: The results show that the administration of MGP attenuated toxin-induced hepatic damage and fibrosis in vivo and inhibited HSC and Kupffer cell activation in vitro, suggesting that MGP might be a promising complementary or alternative therapeutic agent for liver inflammation and fibrosis.

  20. In Vitro Dialysis of Cytokine-Rich Plasma With High and Medium Cut-Off Membranes Reduces Its Procalcific Activity.

    Science.gov (United States)

    Willy, Kevin; Hulko, Michael; Storr, Markus; Speidel, Rose; Gauss, Julia; Schindler, Ralf; Zickler, Daniel

    2017-09-01

    Recently developed high-flux (HF) dialysis membranes with extended permeability provide better clearance of middle-sized molecules such as interleukins (ILs). Whether this modulation of inflammation influences the procalcific effects of septic plasma on vascular smooth muscle cells (VSMCs) is not known. To assess the effects of high cut-off (HCO) and medium cut-off (MCO) membranes on microinflammation and in vitro vascular calcification we developed a miniature dialysis model. Plasma samples from lipopolysaccharide-spiked blood were dialyzed with HF, HCO, and MCO membranes in an in vitro miniature dialysis model. Afterwards, IL-6 concentrations were determined in dialysate and plasma. Calcifying VSMCs were incubated with dialyzed plasma samples and vascular calcification was assessed. Osteopontin (OPN) and matrix Gla protein (MGP) were measured in VSMC supernatants. IL-6 plasma concentrations were markedly lower with HCO and MCO dialysis. VSMC calcification was significantly lower after incubation with MCO- and HCO-serum compared to HF plasma. MGP and OPN levels in supernatants were significantly lower in the MCO but not in the HCO group compared to HF. In vitro dialysis of cytokine-enriched plasma samples with MCO and HCO membranes reduces IL-6 levels. The induction of vascular calcification by cytokine-enriched plasma is reduced after HCO and MCO dialysis. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  1. Inactivation of Escherichia coli O157:H7 and Aerobic Microorganisms in Romaine Lettuce Packaged in a Commercial Polyethylene Terephthalate Container Using Atmospheric Cold Plasma.

    Science.gov (United States)

    Min, Sea C; Roh, Si Hyeon; Boyd, Glenn; Sites, Joseph E; Uknalis, Joseph; Fan, Xuetong; Niemira, Brendan A

    2017-01-01

    The effects of dielectric barrier discharge atmospheric cold plasma (DACP) treatment on the inactivation of Escherichia coli O157:H7 and aerobic microorganisms in romaine lettuce packaged in a conventional commercial plastic container were evaluated during storage at 4°C for 7 days. Effects investigated included the color, carbon dioxide (CO2) generation, weight loss, and surface morphology of the lettuce during storage. Romaine lettuce pieces, with or without inoculation with a cocktail of three strains of E. coli O157:H7 (~6 log CFU/g of lettuce), were packaged in a polyethylene terephthalate commercial clamshell container and treated at 34.8 kV at 1.1 kHz for 5 min by using a DACP treatment system equipped with a pin-type high-voltage electrode. Romaine lettuce samples were analyzed for inactivation of E. coli O157:H7, total mesophilic aerobes, and yeasts and molds, color, CO2 generation, weight loss, and surface morphology during storage at 4°C for 7 days. The DACP treatment reduced the initial counts of E. coli O157:H7 and total aerobic microorganisms by ~1 log CFU/g, with negligible temperature change from 24.5 ± 1.4°C to 26.6 ± 1.7°C. The reductions in the numbers of E. coli O157:H7, total mesophilic aerobes, and yeasts and molds during storage were 0.8 to 1.5, 0.7 to 1.9, and 0.9 to 1.7 log CFU/g, respectively. DACP treatment, however, did not significantly affect the color, CO2 generation, weight, and surface morphology of lettuce during storage (P > 0.05). Some mesophilic aerobic bacteria were sublethally injured by DACP treatment. The results from this study demonstrate the potential of applying DACP as a postpackaging treatment to decontaminate lettuce contained in conventional plastic packages without altering color and leaf respiration during posttreatment cold storage.

  2. Proteomic analysis identifies interleukin 11 regulated plasma membrane proteins in human endometrial epithelial cells in vitro

    Science.gov (United States)

    2011-01-01

    Background During the peri-implantation period, the embryo adheres to an adequately prepared or receptive endometrial surface epithelium. Abnormal embryo adhesion to the endometrium results in embryo implantation failure and infertility. Endometrial epithelial cell plasma membrane proteins critical in regulating adhesion may potentially be infertility biomarkers or targets for treating infertility. Interleukin (IL) 11 regulates human endometrial epithelial cells (hEEC) adhesion. Its production is abnormal in women with infertility. The objective of the study was to identify IL11 regulated plasma membrane proteins in hEEC in vitro using a proteomic approach. Methods Using a 2D-differential in-gel electrophoresis (DIGE) electrophoresis combined with LCMS/MS mass spectrometry approach, we identified 20 unique plasma membrane proteins differentially regulated by IL11 in ECC-1 cells, a hEEC derived cell line. Two IL11 regulated proteins with known roles in cell adhesion, annexin A2 (ANXA2) and flotillin-1 (FLOT1), were validated by Western blot and immunocytochemistry in hEEC lines (ECC-1 and an additional cell line, Ishikawa) and primary hEEC. Flotilin-1 was further validated by immunohistochemistry in human endometrium throughout the menstrual cycle (n = 6-8/cycle). Results 2D-DIGE analysis identified 4 spots that were significantly different between control and IL11 treated group. Of these 4 spots, there were 20 proteins that were identified with LCMS/MS. Two proteins; ANXA2 and FLOT1 were chosen for further analyses and have found to be significantly up-regulated following IL11 treatment. Western blot analysis showed a 2-fold and a 2.5-fold increase of ANXA2 in hEEC membrane fraction of ECC-1 and Ishikawa cells respectively. Similarly, a 1.8-fold and a 2.3/2.4-fold increase was also observed for FLOT1 in hEEC membrane fraction of ECC-1 and Ishikawa cells respectively. In vitro, IL11 induced stronger ANXA2 expression on cell surface of primary hEEC and ECC-1 whilst

  3. Proteomic analysis identifies interleukin 11 regulated plasma membrane proteins in human endometrial epithelial cells in vitro

    Directory of Open Access Journals (Sweden)

    Stanton Peter G

    2011-05-01

    Full Text Available Abstract Background During the peri-implantation period, the embryo adheres to an adequately prepared or receptive endometrial surface epithelium. Abnormal embryo adhesion to the endometrium results in embryo implantation failure and infertility. Endometrial epithelial cell plasma membrane proteins critical in regulating adhesion may potentially be infertility biomarkers or targets for treating infertility. Interleukin (IL 11 regulates human endometrial epithelial cells (hEEC adhesion. Its production is abnormal in women with infertility. The objective of the study was to identify IL11 regulated plasma membrane proteins in hEEC in vitro using a proteomic approach. Methods Using a 2D-differential in-gel electrophoresis (DIGE electrophoresis combined with LCMS/MS mass spectrometry approach, we identified 20 unique plasma membrane proteins differentially regulated by IL11 in ECC-1 cells, a hEEC derived cell line. Two IL11 regulated proteins with known roles in cell adhesion, annexin A2 (ANXA2 and flotillin-1 (FLOT1, were validated by Western blot and immunocytochemistry in hEEC lines (ECC-1 and an additional cell line, Ishikawa and primary hEEC. Flotilin-1 was further validated by immunohistochemistry in human endometrium throughout the menstrual cycle (n = 6-8/cycle. Results 2D-DIGE analysis identified 4 spots that were significantly different between control and IL11 treated group. Of these 4 spots, there were 20 proteins that were identified with LCMS/MS. Two proteins; ANXA2 and FLOT1 were chosen for further analyses and have found to be significantly up-regulated following IL11 treatment. Western blot analysis showed a 2-fold and a 2.5-fold increase of ANXA2 in hEEC membrane fraction of ECC-1 and Ishikawa cells respectively. Similarly, a 1.8-fold and a 2.3/2.4-fold increase was also observed for FLOT1 in hEEC membrane fraction of ECC-1 and Ishikawa cells respectively. In vitro, IL11 induced stronger ANXA2 expression on cell surface of primary h

  4. Coating with Autologous Plasma Improves Biocompatibility of Mesh Grafts In Vitro: Development Stage of a Surgical Innovation

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    Holger Gerullis

    2013-01-01

    Full Text Available Purpose. To investigate mesh coating modalities with autologous blood components in a recently developed in vitro test system for biocompatibility assessment of alloplastic materials. Materials and Methods. Seven different mesh types, currently used in various indications, were randomly investigated. Meshes were coated prior to cultivation with autologous peripheral blood mononuclear cells (PBMCs, platelets, and blood plasma. Pretreated meshes were incubated over 6 weeks in a minced tissue assay, representative for fibroblasts, muscle cells, and endothelial cells originating from 10 different patients. Adherence of those tissues on the meshes was microscopically investigated and semiquantitatively assessed using a previously described scoring system. Results. Coating with peripheral blood mononuclear cells did not affect the adherence score, whereas coating with platelets and blood plasma increased the score suggesting improved biocompatibility in vitro. The previous ranking of native meshes remained consistent after coating. Conclusion. Plasma coating of meshes improves their biocompatibility score in a novel in vitro test system.

  5. A Novel Micro Cold Atmospheric Plasma Device for Glioblastoma Both In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Zhitong Chen

    2017-05-01

    Full Text Available Cold atmospheric plasma (CAP treatment is a rapidly expanding and emerging technology for cancer treatment. Direct CAP jet irradiation is limited to the skin and it can also be invoked as a supplement therapy during surgery as it only causes cell death in the upper three to five cell layers. However, the current cannulas from which the plasma emanates are too large for intracranial applications. To enhance efficiency and expand the applicability of the CAP method for brain tumors and reduce the gas flow rate and size of the plasma jet, a novel micro-sized CAP device (µCAP was developed and employed to target glioblastoma tumors in the murine brain. Various plasma diagnostic techniques were applied to evaluate the physics of helium µCAP such as electron density, discharge voltage, and optical emission spectroscopy (OES. The direct and indirect effects of µCAP on glioblastoma (U87MG-RedFluc cancer cells were investigated in vitro. The results indicate that µCAP generates short- and long-lived species and radicals (i.e., hydroxyl radical (OH, hydrogen peroxide (H2O2, and nitrite (NO2−, etc. with increasing tumor cell death in a dose-dependent manner. Translation of these findings to an in vivo setting demonstrates that intracranial µCAP is effective at preventing glioblastoma tumor growth in the mouse brain. The µCAP device can be safely used in mice, resulting in suppression of tumor growth. These initial observations establish the µCAP device as a potentially useful ablative therapy tool in the treatment of glioblastoma.

  6. Non-thermal plasma modified growth and differentiation process of Capsicum annuum PP805 Godiva in in vitro conditions

    Science.gov (United States)

    Safari, Nasrin; Iranbakhsh, Alireza; Ardebili, Zahra Oraghi

    2017-05-01

    With the aim of evaluating the possible impacts of cold plasma on the structure and growth pattern of Capsicum annuum, the current study was carried out. The seeds were exposed to an argon-derived plasma (0.84 W cm-2 surface power densities) for 0, 1 or 2 minutes. Plasma-treated seeds were grown in the Murashige and Skoog (MS) medium or MS medium supplemented with BA and IAA. The presence of purple stems was recorded in plasma-treated plants grown in the medium supplemented with hormones. The recorded morphological differences were dependent on the exposure time of plasma treatments and/or the presence of hormones in the culture media. Plasma treatment of 1 minute had an improving effect on the shoot and root lengths as well as total leaf area, whereas plasma treatment of 2 minutes had an adverse effect. In contrast to the 1 minute treatment, plasma treatment of 2 minutes significantly impaired growth and hence reduced the total biomass. Alterations in stem diameter and differences in tissue patterns (especially in the vascular system) occurred, and were mainly dependent on the plasma exposure time and/or the presence of hormones. This is a first report on the effects of cold plasma on plant growth in in vitro conditions.

  7. Subcritical Water Hydrolysis Effectively Reduces the In Vitro Seeding Activity of PrPSc but Fails to Inactivate the Infectivity of Bovine Spongiform Encephalopathy Prions.

    Science.gov (United States)

    Murayama, Yuichi; Yoshioka, Miyako; Okada, Hiroyuki; Takata, Eri; Masujin, Kentaro; Iwamaru, Yoshifumi; Shimozaki, Noriko; Yamamura, Tomoaki; Yokoyama, Takashi; Mohri, Shirou; Tsutsumi, Yuji

    2015-01-01

    The global outbreak of bovine spongiform encephalopathy (BSE) has been attributed to the recycling of contaminated meat and bone meals (MBMs) as feed supplements. The use of MBMs has been prohibited in many countries; however, the development of a method for inactivating BSE prions could enable the efficient and safe use of these products as an organic resource. Subcritical water (SCW), which is water heated under pressure to maintain a liquid state at temperatures below the critical temperature (374°C), exhibits strong hydrolytic activity against organic compounds. In this study, we examined the residual in vitro seeding activity of protease-resistant prion protein (PrPSc) and the infectivity of BSE prions after SCW treatments. Spinal cord homogenates prepared from BSE-infected cows were treated with SCW at 230-280°C for 5-7.5 min and used to intracerebrally inoculate transgenic mice overexpressing bovine prion protein. Serial protein misfolding cyclic amplification (sPMCA) analysis detected no PrPSc in the SCW-treated homogenates, and the mice treated with these samples survived for more than 700 days without any signs of disease. However, sPMCA analyses detected PrPSc accumulation in the brains of all inoculated mice. Furthermore, secondary passage mice, which inoculated with brain homogenates derived from a western blotting (WB)-positive primary passage mouse, died after an average of 240 days, similar to mice inoculated with untreated BSE-infected spinal cord homogenates. The PrPSc accumulation and vacuolation typically observed in the brains of BSE-infected mice were confirmed in these secondary passage mice, suggesting that the BSE prions maintained their infectivity after SCW treatment. One late-onset case, as well as asymptomatic but sPMCA-positive cases, were also recognized in secondary passage mice inoculated with brain homogenates from WB-negative but sPMCA-positive primary passage mice. These results indicated that SCW-mediated hydrolysis was

  8. [In vitro comparison of antibacterial properties of plasma sprayed wollastonite coatings loading silver and gentamicin].

    Science.gov (United States)

    Dong, Yu-qi; Li, Bao-e; Liu, Xuan-yong; Feng, Yu; Cao, Cong

    2008-12-15

    To develop antibacterial coatings for orthopedic implants with a sustained release of drugs. Wollastonite coatings were deposited on the titanium substrates by an atmospheric plasma spray system. After soaking in weight percent of 5% AgNO(3) solution for 24 h, the wollastonite coatings loading silver were obtained. Gentamicin were loaded on the wollastonite coatings by collagen grafting process. The release rates of drugs from wollastonite coatings were investigated by the in vitro solution soaking test. One strain of S. aureus was used in zone of inhibition test to evaluate the antibacterial properties of drug loaded wollastonite coatings, and the cell culture test was used to evaluate their cytotoxicity. Silver and gentamicin loaded wollastonite coatings were successfully prepared. The release of silver ions from the silver loaded wollastonite coatings lasted 50 d in deionized water, effectively inhibiting the growth of S. aureus for 40 d. While an initial burst release of gentamicin was found during the in vitro solution soaking test. The gentamicin released from gentamicin loaded wollastonite coatings can inhibit the growth of S. aureus for 18 d. Both the two kinds of antibacterial wollastonite coatings showed no adverse effect on cellular adhesion, proliferation and alkaline phosphatase expression. Compared with gentamicin loaded wollastonite coatings, silver loaded wollastonite coatings may have more promising clinical applications due to the even and long-time antibacterial agent release.

  9. In vitro cytotoxicity of carbon black nanoparticles synthesized from solution plasma on human lung fibroblast cells

    Science.gov (United States)

    Panomsuwan, Gasidit; Chokradjaroen, Chayanaphat; Rujiravanit, Ratana; Ueno, Tomonaga; Saito, Nagahiro

    2018-01-01

    Carbon black nanoparticles (CB-NPs) have been synthesized from liquid benzene by a solution plasma method at room temperature and atmospheric pressure. The morphological observation by scanning electron microscopy revealed the agglomeration of aggregated fine particles. The synthesized CB-NPs were predominantly amorphous as confirmed by X-ray diffraction. The in vitro cytotoxicity of CB-NPs on the human lung fibroblast (MRC-5) cell line was assessed by the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and systematically compared with those of two types of commercial carbon blacks (i.e., Vulcan XC-72 and Ketjenblack EC-600JD). Cell viabilities were studied at different concentrations of 32.5, 65, 125, and 250 µg/mL. It was found that the CB-NPs derived from solution plasma exhibited a lower cytotoxicity on the MRC-5 cells than the other two comparative carbon blacks. The viability of MRC-5 cells exposed to CB-NPs remained higher than 90% even at a high concentration of 250 µg/mL. This result preliminarily confirmed the biosafety and potential use of CB-NPs in the field of biological applications.

  10. Accumulation of genistein and lipophilic genistein derivatives in lipoproteins during incubation with human plasma in vitro.

    Science.gov (United States)

    Kaamanen, Maija; Adlercreutz, Herman; Jauhiainen, Matti; Tikkanen, Matti J

    2003-03-17

    Atherosclerosis is initiated by the uptake and retention of oxidized low-density lipoprotein (LDL) into the arterial intima. We have previously shown that dietary isoflavone phytoestrogens inhibit LDL oxidation in vitro. The inhibition could have been caused by undetected isoflavone metabolites associated with lipoproteins. In the present study, we incubated human plasma with [3H]genistein, both with and without the lecithin:cholesterol acyltransferase (LCAT) inhibitor dithionitrobenzoic acid (DTNB). Our results indicated that the 3H-label was attached to both high-density lipoprotein (HDL) and LDL, and that it represented both underivatized genistein and lipophilic derivatives of genistein, part of which were identified as fatty acid monoesters. The latter was demonstrated by the findings that DTNB decreased the HDL and LDL associated radioactivity in the lipophilic fraction isolated by hydrophobic chromatography and that saponification hydrolysis liberated a corresponding part of the 3H-label. Two-dimensional reversed-phase thin-layer chromatography (TLC) demonstrated that a corresponding part of the radioactivity comigrated with genistein monoester standards in the absence of DTNB but was abolished if DTNB had been present in the incubation. In summary, incubation of plasma with [3H]genistein resulted in accumulation of underivatized genistein as well as lipophilic genistein derivatives in lipoproteins. A smaller part of the latter were genistein monoesters, while part remained unidentified. Our results suggest an explanation for the increased oxidation resistance of isolated LDL during intake of soybean isoflavones.

  11. Effects of platelet-rich plasma in a model of bovine endometrial inflammation in vitro.

    Science.gov (United States)

    Marini, Maria Giovanna; Perrini, Claudia; Esposti, Paola; Corradetti, Bruna; Bizzaro, Davide; Riccaboni, Pietro; Fantinato, Eleonora; Urbani, Giuseppe; Gelati, Giorgio; Cremonesi, Fausto; Lange-Consiglio, Anna

    2016-09-13

    Endometritis reduces fertility and is responsible for major economic losses in beef and dairy industries. The aim of this study was to evaluate an alternative therapy using platelet-rich plasma (PRP). PRP was tested in vivo, after bovine intrauterine administration, and in vitro on endometrial cells. Bovine endometrial cells were cultured until passage (P) 10 with 5 % or 10 % PRP. Effect of PRP on endometrial cell proliferation and on the expression of genes [prostaglandin-endoperoxide synthase 2 (COX2), tumor protein p53 (TP53), oestrogen receptors (ER-α and ER-β), progesterone receptor (PR) and c-Myc] involved in the regulation of oestrus cycle and fetal-maternal interaction were evaluated. Moreover, to evaluate the ability of PRP to counteract inflammation, 10 and 100 ng/ml of bacterial endotoxin lipopolysaccharide (LPS) were used to inflame endometrial cells in vitro for 1, 6, 12, 24 and 48 h. The expression of genes such as interleukin 1β (IL-1β), interleukin-8 (IL-8), inducible nitric oxide synthase (iNOS), prostaglandin-endoperoxide synthase 2 (COX2/PTGS2), and the release of PGE-2, IL-1β and IL-8 were evaluated. In vivo treatment with PRP increased the detection of PR. In vitro, 5 % PRP at passage 5 increased proliferation rate and induced a significant increase in the expression of all studied genes. Furthermore, the results revealed that 10 ng/ml of LPS is the most effective dose to obtain an inflammatory response, and that PRP treatment significantly down regulated the expression of pro-inflammatory genes. This study lays the foundations for the potential treatment of endometritis with PRP in vivo.

  12. Enzymatic degradation of in vitro Staphylococcus aureus biofilms supplemented with human plasma.

    Science.gov (United States)

    Watters, Chase M; Burton, Tarea; Kirui, Dickson K; Millenbaugh, Nancy J

    2016-01-01

    Enzymatic debridement is a therapeutic strategy used clinically to remove necrotic tissue from wounds. Some of the enzymes utilized for debridement have been tested against bacterial pathogens, but the effectiveness of these agents in dispersing clinically relevant biofilms has not been fully characterized. Here, we developed an in vitro Staphylococcus aureus biofilm model that mimics wound-like conditions and employed this model to investigate the antibiofilm activity of four enzymatic compounds. Human plasma at concentrations of 0%-50% was supplemented into growth media and used to evaluate biofilm biomass accumulation over 24 hours and 48 hours in one methicillin-sensitive and five methicillin-resistant strains of S. aureus. Supplementation of media with 10% human plasma resulted in the most robust biofilms in all six strains. The enzymes α-amylase, bromelain, lysostaphin, and papain were then tested against S. aureus biofilms cultured in 10% human plasma. Quantification of biofilms after 2 hours and 24 hours of treatment using the crystal violet assay revealed that lysostaphin decreased biomass by up to 76%, whereas α-amylase, bromelain, and papain reduced biomass by up to 97%, 98%, and 98%, respectively. Scanning electron microscopy confirmed that the dispersal agents detached the biofilm exopolysaccharide matrix and bacteria from the growth surface. Lysostaphin caused less visible dispersal of the biofilms, but unlike the other enzymes, induced morphological changes indicative of bacterial cell damage. Overall, our results indicate that use of enzymes may be an effective means of eradicating biofilms and a promising strategy to improve treatment of multidrug-resistant bacterial infections.

  13. Enzymatic degradation of in vitro Staphylococcus aureus biofilms supplemented with human plasma

    Directory of Open Access Journals (Sweden)

    Watters CM

    2016-04-01

    Full Text Available Chase M Watters,1,2 Tarea Burton,1 Dickson K Kirui,1 Nancy J Millenbaugh1 1Maxillofacial Injury and Disease Department, Naval Medical Research Unit San Antonio, Joint Base San Antonio-Fort Sam Houston, TX, USA; 2Wound Infections Department, Naval Medical Research Center, Silver Spring, MD, USA Abstract: Enzymatic debridement is a therapeutic strategy used clinically to remove necrotic tissue from wounds. Some of the enzymes utilized for debridement have been tested against bacterial pathogens, but the effectiveness of these agents in dispersing clinically relevant biofilms has not been fully characterized. Here, we developed an in vitro Staphylococcus aureus biofilm model that mimics wound-like conditions and employed this model to investigate the antibiofilm activity of four enzymatic compounds. Human plasma at concentrations of 0%–50% was supplemented into growth media and used to evaluate biofilm biomass accumulation over 24 hours and 48 hours in one methicillin-sensitive and five methicillin-resistant strains of S. aureus. Supplementation of media with 10% human plasma resulted in the most robust biofilms in all six strains. The enzymes α-amylase, bromelain, lysostaphin, and papain were then tested against S. aureus biofilms cultured in 10% human plasma. Quantification of biofilms after 2 hours and 24 hours of treatment using the crystal violet assay revealed that lysostaphin decreased biomass by up to 76%, whereas a-amylase, bromelain, and papain reduced biomass by up to 97%, 98%, and 98%, respectively. Scanning electron microscopy confirmed that the dispersal agents detached the biofilm exopolysaccharide matrix and bacteria from the growth surface. Lysostaphin caused less visible dispersal of the biofilms, but unlike the other enzymes, induced morphological changes indicative of bacterial cell damage. Overall, our results indicate that use of enzymes may be an effective means of eradicating biofilms and a promising strategy to improve

  14. In vitro characterization of two different atmospheric plasma jet chemical functionalizations of titanium surfaces

    Science.gov (United States)

    Mussano, F.; Genova, T.; Verga Falzacappa, E.; Scopece, P.; Munaron, L.; Rivolo, P.; Mandracci, P.; Benedetti, A.; Carossa, S.; Patelli, A.

    2017-07-01

    Plasma surface activation and plasma polymers deposition are promising technologies capable to modulate biologically relevant surface features of biomaterials. The purpose of this study was to evaluate the biological effects of two different surface modifications, i.e. amine (NH2-Ti) and carboxylic/esteric (COOH/R-Ti) functionalities obtained from 3-aminopropyltriethoxysilane (3-APTES) and methylmethacrylate (MMA) precursors, respectively, through an atmospheric plasma jet RF-APPJ portable equipment. The coatings were characterized by Scanning Electron Microscopy, FT-IR spectroscopy, XPS and surface energy calculations. Stability in water and after UV sterilization were also verified. The pre-osteoblastic murine cell line MC3T3-E1 was used to perform the in-vitro tests. The treated samples showed a higher quantity of adsorbed proteins and improved osteoblast cells adhesion on the surfaces compared to the pristine titanium, in particular the COOH/R-Ti led to a nearly two-fold improvement. Cell proliferation on coated samples was initially (at 24 h) lower than on titanium control, while, at 48 h, COOH/R-Ti reached the proliferation rate of pristine titanium. Cells grown on NH2-Ti were more tapered and elongated in shape with lower areas than on COOH/R-Ti enriched surfaces. Finally, NH2-Ti significantly enhanced osteocalcin production, starting from 14 days, while COOH/R-Ti had this effect only from 21 days. Notably, NH2-Ti was more efficient than COOH/R-Ti at 21 days. The amine functionality elicited the most relevant osteogenic effect in terms of osteocalcin expression, thus establishing an interesting correlation between early cell morphology and later differentiation stages. Taken together, these data encourage the use of the functionalization procedures here reported in further studies.

  15. In vitro efficacy of cold atmospheric pressure plasma on S. sanguinis biofilms in comparison of two test models

    Directory of Open Access Journals (Sweden)

    Gorynia, Susanne

    2013-04-01

    Full Text Available [english] Dental plaque critically affects the etiology of caries, periodontitis and periimplantitis. The mechanical removal of plaque can only be performed partially due to limited accessibility. Therefore, plaque still represents one of the major therapeutic challenges. Even though antiseptic mouth rinses reduce the extent of biofilm temporarily, plaque removal remains incomplete and continuous usage can even result in side effects. Here we tested argon plasma produced by kinpen09 as one option to inactivate microorganisms and to eliminate plaque. biofilms cultivated in either the European Biofilm Reactor (EUREBI or in 24 well plates were treated with argon plasma. In both test systems a homogeneous, good analyzable and stable biofilm was produced on the surface of titan plates within 72 h (>6,9 log CFU/ml. Despite the significantly more powerful biofilm production in EUREBI, the difference of 0.4 log CFU/ml between EUREBI and the 24 well plates was practically not relevant. For that reason both test models were equally qualified for the analysis of efficacy of cold atmospheric pressure plasma. We demonstrate a significant reduction of the biofilm compared to the control in both test models. After plasma application of 180 s the biofilm produced in EUREBI or in 24 well plates was decreased by 0.6 log CFU/ml or 0.5 log CFU/ml, respectively. In comparison to recently published studies analyzing the efficacy of kinpen09, produces a hardly removable biofilm. Future investigations using reduced distances between plasma source and biofilm, various compositions of plasma and alternative plasma sources will contribute to further optimization of the efficacy against biofilms.

  16. Thrombin generation, ProC(®)Global, prothrombin time and activated partial thromboplastin time in thawed plasma stored for seven days and after methylene blue/light pathogen inactivation.

    Science.gov (United States)

    Thiele, Thomas; Hron, Gregor; Kellner, Sarah; Wasner, Christina; Westphal, Antje; Warkentin, Theodore E; Greinacher, Andreas; Selleng, Kathleen

    2016-01-01

    Methylene blue pathogen inactivation and storage of thawed plasma both lead to changes in the activity of several clotting factors. We investigated how this translates into a global loss of thrombin generation potential and alterations in the protein C pathway. Fifty apheresis plasma samples were thawed and each divided into three subunits. One subunit was stored for 7 days at 4 °C, one was stored for 7 days at 22 °C and one was stored at 4 °C after methylene blue/light treatment. Thrombin generation parameters, ProC(®)Global-NR, prothrombin time and activated partial thromboplastin time were assessed on days 0 and 7. The velocity of thrombin generation increased significantly after methylene blue treatment (increased thrombin generation rate; time to peak decreased) and decreased after storage (decreased thrombin generation rate and peak thrombin; increased lag time and time to peak). The endogenous thrombin generation potential remained stable after methylene blue treatment and storage at 4 °C. Methylene blue treatment and 7 days of storage at 4 °C activated the protein C pathway, whereas storage at room temperature and storage after methylene blue treatment decreased the functional capacity of the protein C pathway. Prothrombin time and activated partial thromboplastin time showed only modest alterations. The global clotting capacity of thawed plasma is maintained at 4 °C for 7 days and directly after methylene blue treatment of thawed plasma. Thrombin generation and ProC(®)Global are useful tools for investigating the impact of pathogen inactivation and storage on the clotting capacity of therapeutic plasma preparations.

  17. Photochemical inactivation of pathogenic bacteria in human platelet concentrates.

    Science.gov (United States)

    Lin, L; Londe, H; Janda, J M; Hanson, C V; Corash, L

    1994-05-01

    Platelet concentrates (PC) may be infrequently contaminated with low levels of bacteria that can cause septicemia and death in patients receiving transfusion therapy. We evaluated the efficacy of a photochemical decontamination (PCD) technique using 8-methoxypsoralen (8-MOP) and long wavelength UV light (UVA) to inactivate bacteria in standard therapeutic PC. Twelve phylogenetically distinct pathogenic bacteria, 5 gram-positive and 7 gram-negative organisms, were seeded into PC to a final challenge dose ranging from 10(5) to 10(7) colony-forming units (CFU)/mL. Contaminated PC were treated with 8-MOP (5 micrograms/mL) and 5 J/cm2 of UVA, a PCD treatment regimen found to adequately preserve in vitro platelet function. Greater than 10(5) CFU/mL of all 5 gram-positive (Staphylococcus aureus, Streptococcus epidermidis, Streptococcus pyogenes, Listeria monocytogenes, and Corynebacterium minutissimum) and 2 of the gram-negative (Escherichia coli and Yersinia enterocolitica) organisms were inactivated. The remaining 5 gram-negative organisms were more resistant, with less than 10(1) to 10(3.7) CFU/mL inactivated under these conditions. The inactivation efficiency for this resistant group of gram-negative organisms was improved when PC were resuspended in a synthetic storage medium with reduced plasma protein concentration (15%) and an increased 8-MOP concentration (23.4 micrograms/mL). Illumination with 3 J/cm2 of UVA in this system inactivated greater than 10(5) CFU/mL of 4 resistant gram-negative organisms (Salmonella choleraesuis, Enterobacter cloacae, Serratia marcescens, and Klebsiella pneumoniae) and 10(4.1) CFU/mL of the most resistant gram-negative organism (Pseudomonas aeruginosa). This level of PCD treatment did not adversely affect in vitro platelet function. These results demonstrate that PCD using 8-MOP (5 to 23.4 micrograms/mL) effectively inactivated high levels of pathogenic bacteria in PC with adequate preservation of in vitro platelet properties.

  18. In vitro characterization of two different atmospheric plasma jet chemical functionalizations of titanium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mussano, F., E-mail: federico.mussano@unito.it [CIR Dental School, Department of Surgical Sciences UNITO, via Nizza 230, 10126, Turin (Italy); Genova, T. [CIR Dental School, Department of Surgical Sciences UNITO, via Nizza 230, 10126, Turin (Italy); Department of Life Sciences and Systems Biology, UNITO, via Accademia Albertina 13, 10123, Turin (Italy); Verga Falzacappa, E. [Department of Molecular Science and Nanosystems, UNIVE, Via Torino 155, 30170, Venezia (Italy); Nadir srl, Via Torino 155, 30170 Venezia (Italy); Scopece, P. [Nadir srl, Via Torino 155, 30170 Venezia (Italy); Munaron, L. [Department of Life Sciences and Systems Biology, UNITO, via Accademia Albertina 13, 10123, Turin (Italy); Centre for Nanostructured Interfaces and Surfaces (NIS) (Italy); Rivolo, P.; Mandracci, P. [Politecnico di Torino, Department of Applied Science and Technology, Materials and Microsoystems Laboratory (ChiLab), Corso Duca degli Abruzzi 24, 10129, Torino (Italy); Benedetti, A. [Department of Molecular Science and Nanosystems, UNIVE, Via Torino 155, 30170, Venezia (Italy); Carossa, S. [CIR Dental School, Department of Surgical Sciences UNITO, via Nizza 230, 10126, Turin (Italy); Patelli, A. [Department of Physics and Astronomy, UNIPD, via Marzolo 8, 35122 Padova (Italy)

    2017-07-01

    Highlights: • NH{sub 2}-Ti and COOH/R-Ti obtained via atmospheric plasma jet RF-APPJ portable equipment. • Higher quantity of adsorbed proteins and improved cell adhesion on treated surfaces. • More tapered and elongated cells on NH{sub 2}-Ti compared to COOH/R-Ti. • Higher osteocalcin expression on NH{sub 2}-Ti. - Abstract: Plasma surface activation and plasma polymers deposition are promising technologies capable to modulate biologically relevant surface features of biomaterials. The purpose of this study was to evaluate the biological effects of two different surface modifications, i.e. amine (NH{sub 2}-Ti) and carboxylic/esteric (COOH/R-Ti) functionalities obtained from 3-aminopropyltriethoxysilane (3-APTES) and methylmethacrylate (MMA) precursors, respectively, through an atmospheric plasma jet RF-APPJ portable equipment. The coatings were characterized by Scanning Electron Microscopy, FT-IR spectroscopy, XPS and surface energy calculations. Stability in water and after UV sterilization were also verified. The pre-osteoblastic murine cell line MC3T3-E1 was used to perform the in-vitro tests. The treated samples showed a higher quantity of adsorbed proteins and improved osteoblast cells adhesion on the surfaces compared to the pristine titanium, in particular the COOH/R-Ti led to a nearly two-fold improvement. Cell proliferation on coated samples was initially (at 24 h) lower than on titanium control, while, at 48 h, COOH/R-Ti reached the proliferation rate of pristine titanium. Cells grown on NH{sub 2}-Ti were more tapered and elongated in shape with lower areas than on COOH/R-Ti enriched surfaces. Finally, NH{sub 2}-Ti significantly enhanced osteocalcin production, starting from 14 days, while COOH/R-Ti had this effect only from 21 days. Notably, NH{sub 2}-Ti was more efficient than COOH/R-Ti at 21 days. The amine functionality elicited the most relevant osteogenic effect in terms of osteocalcin expression, thus establishing an interesting correlation

  19. The importance of selecting a proper biological milieu for protein corona analysis in vitro: Human plasma versus human serum.

    Science.gov (United States)

    Mirshafiee, Vahid; Kim, Raehyun; Mahmoudi, Morteza; Kraft, Mary L

    2016-06-01

    Nanoparticle (NP) exposure to biological fluids in the body results in protein binding to the NP surface, which forms a protein coating that is called the "protein corona". To simplify studies of protein-NP interactions and protein corona formation, NPs are incubated with biological solutions, such as human serum or human plasma, and the effects of this exposure are characterized in vitro. Yet, how NP exposure to these two different biological milieus affects protein corona composition and cell response has not been investigated. Here, we explore the differences between the protein coronas that form when NPs are incubated in human serum versus human plasma. NP characterization indicated that NPs that were exposed to human plasma had higher amounts of proteins bound to their surfaces, and were slightly larger in size than those exposed to human serum. In addition, significant differences in corona composition were also detected with gel electrophoresis and liquid chromatography-mass spectrometry/mass spectrometry, where a higher fraction of coagulation proteins and complement factors were found on the plasma-exposed NPs. Flow cytometry and confocal microscopy showed that the uptake of plasma-exposed NPs was higher than that of serum-exposed NPs by RAW 264.7 macrophage immune cells, but not by NIH 3T3 fibroblast cells. This difference is likely due to the elevated amounts of opsonins, such as fibrinogen, on the surfaces of the NPs exposed to plasma, but not serum, because these components trigger NP internalization by immune cells. As the human plasma better mimics the composition of the in vivo environment, namely blood, in vitro protein corona studies should employ human plasma, and not human serum, so the biological phenomena that is observed is more similar to that occurring in vivo. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. The effective concentration of epsilon-aminocaproic Acid for inhibition of fibrinolysis in neonatal plasma in vitro.

    Science.gov (United States)

    Yurka, Heather G; Wissler, Richard N; Zanghi, Christine N; Liu, Xiang; Tu, Xin; Eaton, Michael P

    2010-07-01

    Pediatric patients, particularly neonates, are at high risk for bleeding complications after cardiovascular surgery because of their immature hemostatic system, small size, and the complex operations they require. Activation of intravascular fibrinolysis is one of the principle effects of cardiopulmonary bypass that causes poor postoperative hemostasis. This complication has long been recognized and treated with antifibrinolytic medications, including the lysine analog epsilon aminocaproic acid (EACA). The therapeutic plasma concentration of EACA has been scientifically determined for the adult population, but the current recommended dosage for neonates has been empirically derived from adult studies. Therefore, we investigated the appropriate concentration of EACA for neonates undergoing bypass. We conducted an in vitro study using neonatal plasma derived from the placenta/cord units from 20 term, elective cesarean deliveries. Graded concentrations of EACA were added to aliquots of the plasma pool before activating fibrinolysis with tissue-type plasminogen activator. Standard kaolin-activated thromboelastograms were then run with the primary outcome variable being estimated percent lysis. These procedures were repeated on samples of commercially available pooled adult normal plasma for comparison. We found that neonatal plasma required significantly lower concentrations of EACA to completely prevent fibrinolysis than did adult plasma (44.2 microg/mL and 47.8 microg/mL for neonatal plasma and 94.4 and 131.4 microg/mL in adult plasma for 400 and 1000 U/mL of plasminogen activator, respectively, P < 0.001). Our data establish the minimal effective concentration of EACA necessary to completely prevent fibrinolysis in neonatal blood in vitro. This concentration is significantly less than that targeted by current dosing schemes, indicating that neonates are possibly being exposed to greater levels of EACA than is clinically necessary.

  1. Spray-dried plasma and fresh frozen plasma modulate permeability and inflammation in vitro in vascular endothelial cells

    NARCIS (Netherlands)

    Wataha, K.; Menge, T.; Deng, X.; Shah, A.; Bode, A.; Holcomb, J.B.; Potter, D.; Kozar, R.; Spinella, P.C.; Pati, S.

    2013-01-01

    BACKGROUND: After major traumatic injury, patients often require multiple transfusions of fresh frozen plasma (FFP) to correct coagulopathy and to reduce bleeding. A spray-dried plasma (SDP) product has several logistical benefits over FFP use in trauma patients with coagulopathy. These benefits

  2. Cold Plasma-activated hydrogen peroxide aerosol inactivates Escherichia coli 0157:H7, Salmonella Typhimurium, and Listeria innocua and maintains quality of grape tomato, spinach and cantaloupe

    Science.gov (United States)

    The purpose of this study was to investigate the efficacy of aerosolized hydrogen peroxide in inactivating bacteria and maintaining quality of grape tomato, baby spinach leaves and cantaloupe. Stem scar and smooth surfaces of tomatoes, spinach leaves, and cantaloupe rinds, inoculated with Escherich...

  3. Triacylglycerol-rich lipoproteins protect lipoprotein lipase from inactivation by ANGPTL3 and ANGPTL4.

    Science.gov (United States)

    Nilsson, Stefan K; Anderson, Fredrick; Ericsson, Madelene; Larsson, Mikael; Makoveichuk, Elena; Lookene, Aivar; Heeren, Joerg; Olivecrona, Gunilla

    2012-10-01

    Lipoprotein lipase (LPL) is important for clearance of triacylglycerols (TG) from plasma both as an enzyme and as a bridging factor between lipoproteins and receptors for endocytosis. The amount of LPL at the luminal side of the capillary endothelium determines to what extent lipids are taken up. Mechanisms to control both the activity of LPL and its transport to the endothelial sites are regulated, but poorly understood. Angiopoietin-like proteins (ANGPTLs) 3 and 4 are potential control proteins for LPL, but plasma concentrations of ANGPTLs do not correlate with plasma TG levels. We investigated the effects of recombinant human N-terminal (NT) ANGPTLs3 and 4 on LPL-mediated bridging of TG-rich lipoproteins to primary mouse hepatocytes and found that the NT-ANGPTLs, in concentrations sufficient to cause inactivation of LPL in vitro, were unable to prevent LPL-mediated lipoprotein uptake. We therefore investigated the effects of lipoproteins (chylomicrons, VLDL and LDL) on the inactivation of LPL in vitro by NT-ANGPTLs3 and 4 and found that LPL activity was protected by TG-rich lipoproteins. In vivo, postprandial TG protected LPL from inactivation by recombinant NT-ANGPTL4 injected to mice. We conclude that lipoprotein-bound LPL is stabilized against inactivation by ANGPTLs. The levels of ANGPTLs found in blood may not be sufficient to overcome this stabilization. Therefore it is likely that the prime site of action of ANGPTLs on LPL is in subendothelial compartments where TG-rich lipoprotein concentration is lower than in blood. This could explain why the plasma levels of TG and ANGPTLs do not correlate. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. An unusually large 5q duplication in an adult female subject: spreading of inactivation and in vitro instability of the derivative Xp/5q chromosome.

    Science.gov (United States)

    Rovescalli, A; Ghidoni, A

    1989-01-01

    An unbalanced translocation resulting in an unusually large partial 5q trisomy (5q11-5qter) and partial Xp monosomy (Xp11-Xpter) is reported in a 24 yr old woman with phenotypic abnormalities including gonadal dysgenesis and mental retardation. The karyotypes of the parents and the brother were found normal. Peripheral blood stimulated lymphocytes and cutaneous fibroblasts of the proband exhibited constantly, after BrdU incorporation, selective inactivation of the derivative X;5 chromosome spreading to the 5q duplicate segment. A variety of numerical and structural changes involving the derivative chromosome were observed in about 10% of cells of the cultured lymphoblastoid line established from the subject's lymphocytes. The extended 5q duplication, according to the literature, is generally accompanied by a severe phenotype and by developmental failure; it is therefore believe that genetic inactivation of the 5q duplicated region permitted the proband's development to adult age, despite the profound chromosomal imbalance.

  5. Platelet-Derived Short-Chain Polyphosphates Enhance the Inactivation of Tissue Factor Pathway Inhibitor by Activated Coagulation Factor XI.

    Directory of Open Access Journals (Sweden)

    Cristina Puy

    Full Text Available Factor (F XI supports both normal human hemostasis and pathological thrombosis. Activated FXI (FXIa promotes thrombin generation by enzymatic activation of FXI, FIX, FX, and FV, and inactivation of alpha tissue factor pathway inhibitor (TFPIα, in vitro. Some of these reactions are now known to be enhanced by short-chain polyphosphates (SCP derived from activated platelets. These SCPs act as a cofactor for the activation of FXI and FV by thrombin and FXIa, respectively. Since SCPs have been shown to inhibit the anticoagulant function of TFPIα, we herein investigated whether SCPs could serve as cofactors for the proteolytic inactivation of TFPIα by FXIa, further promoting the efficiency of the extrinsic pathway of coagulation to generate thrombin.Purified soluble SCP was prepared by size-fractionation of sodium polyphosphate. TFPIα proteolysis was analyzed by western blot. TFPIα activity was measured as inhibition of FX activation and activity in coagulation and chromogenic assays. SCPs significantly accelerated the rate of inactivation of TFPIα by FXIa in both purified systems and in recalcified plasma. Moreover, platelet-derived SCP accelerated the rate of inactivation of platelet-derived TFPIα by FXIa. TFPIα activity was not affected by SCP in recalcified FXI-depleted plasma.Our data suggest that SCP is a cofactor for TFPIα inactivation by FXIa, thus, expanding the range of hemostatic FXIa substrates that may be affected by the cofactor functions of platelet-derived SCP.

  6. In vitro sealing of iatrogenic fetal membrane defects by a collagen plug imbued with fibrinogen and plasma.

    Science.gov (United States)

    Engels, A C; Hoylaerts, M F; Endo, M; Loyen, S; Verbist, G; Manodoro, S; DeKoninck, P; Richter, J; Deprest, J A

    2013-02-01

    We aimed to demonstrate local thrombin generation by fetal membranes, as well as its ability to generate fibrin from fibrinogen concentrate. Furthermore, we aimed to investigate the efficacy of collagen plugs, soaked with plasma and fibrinogen, to seal iatrogenic fetal membrane defects. Thrombin generation by homogenized fetal membranes was measured by calibrated automated thrombography. To identify the coagulation caused by an iatrogenic membrane defect, we analyzed fibrin formation by optical densitometry, upon various concentrations of fibrinogen. The ability of a collagen plug soaked with fibrinogen and plasma was tested in an ex vivo model for its ability to seal an iatrogenic fetal membrane defect. Fetal membrane homogenates potently induced thrombin generation in amniotic fluid and diluted plasma. Upon the addition of fibrinogen concentrate, potent fibrin formation was triggered. Measured by densiometry, fibrin formation was optimal at 1250 µg/mL fibrinogen in combination with 4% plasma. A collagen plug soaked with fibrinogen and plasma sealed an iatrogenic membrane defect about 35% better than collagen plugs without these additives (P = 0.037). These in vitro experiments suggest that the addition of fibrinogen and plasma may enhance the sealing efficacy of collagen plugs in closing iatrogenic fetal membrane defects. © 2013 John Wiley & Sons, Ltd.

  7. Extracorporeal Shockwave Therapy Increases Growth Factor Release from Equine Platelet-Rich Plasma In Vitro

    Directory of Open Access Journals (Sweden)

    Kathryn A. Seabaugh

    2017-12-01

    Full Text Available IntroductionExtracorporeal shockwave therapy (ESWT and platelet-rich plasma (PRP are common treatments for soft tissue injuries in horses. Shockwave triggers cell specific responses to promote healing. Growth factors released from PRP also promote healing. It has been hypothesized that greater growth factor release would amplify the healing process. The combination of ESWT and PRP could promote healing in injured tendons and ligaments in the horse. The objective of this study was to determine if application of shockwaves to PRP samples increases the concentration of transforming growth factor-β1 (TGF-β1 and platelet-derived growth factor ββ (PDGF-ββ released from the platelets in vitro.Materials and methodsPRP was produced from blood drawn from six horses. The PRP from each horse was exposed to the following treatments: (1 positive control (freeze-thaw cycle, (2 untreated negative control, or shockwaves with either (3 a “standard probe” (ESWT-S with a 2 cm focal width and medium energy density or (4 a “power probe” (ESWT-P with a 1 cm focal width and high energy density. After each treatment, the samples were centrifuged, and the supernatant was harvested. The supernatant was then used for growth factor quantification via commercially available ELISA kits for TGF-β1 and PDGF-ββ.ResultsConcentrations of TGF-β1 and PDGF-ββ in PRP that underwent a freeze-thaw cycle were significantly increased compared with all other treatments. Both ESWT-S and ESWT-P resulted in significantly increased TGF-β1 concentrations, 46 and 33%, respectively, when compared with the negative control. Both ESWT-S and ESWT-P resulted in significantly increased PDGF-ββ concentrations, 219 and 190%, respectively, when compared with the negative control.DiscussionThese data indicate that the application of ESWT to PRP increases the expression of growth factors in vitro. This suggests that the combination therapy of local PRP injection followed by ESWT

  8. Gadolinium-based magnetic resonance contrast agents at 7 Tesla: in vitro T1 relaxivities in human blood plasma.

    Science.gov (United States)

    Noebauer-Huhmann, Iris M; Szomolanyi, Pavol; Juras, Vladimír; Kraff, Oliver; Ladd, Mark E; Trattnig, Siegfried

    2010-09-01

    PURPOSE/INTRODUCTION: The aim of this study was to determine the T1 relaxivities (r1) of 8 gadolinium (Gd)-based MR contrast agents in human blood plasma at 7 Tesla, compared with 3 Tesla. Eight commercially available Gd-based MR contrast agents were diluted in human blood plasma to concentrations of 0, 0.25, 0.5, 1, and 2 mmol/L. In vitro measurements were performed at 37 degrees C, on a 7 Tesla and on a 3 Tesla whole-body magnetic resonance imaging scanner. For the determination of T1 relaxation times, Inversion Recovery Sequences with inversion times from 0 to 3500 ms were used. The relaxivities were calculated. The r1 relaxivities of all agents, diluted in human blood plasma at body temperature, were lower at 7 Tesla than at 3 Tesla. The values at 3 Tesla were comparable to those published earlier. Notably, in some agents, a minor negative correlation of r1 with a concentration of up to 2 mmol/L could be observed. This was most pronounced in the agents with the highest protein-binding capacity. At 7 Tesla, the in vitro r1 relaxivities of Gd-based contrast agents in human blood plasma are lower than those at 3 Tesla. This work may serve as a basis for the application of Gd-based MR contrast agents at 7 Tesla. Further studies are required to optimize the contrast agent dose in vivo.

  9. In vitro evaluation of the inhibitory effect of canine serum, canine fresh frozen plasma, freeze-thaw-cycled plasma, and Solcoseryl™ on matrix metalloproteinases 2 and 9.

    Science.gov (United States)

    Chow, Derek W Y; Chau, Ying; Yeung, Wai Kit; Westermeyer, Hans D

    2015-05-01

    Compare the efficacy of canine serum, fresh frozen plasma (FFP), freeze-thaw-cycled plasma (FTCP), and Solcoseryl(™) at inhibiting matrix metalloproteinases (MMP) 2 and 9 in vitro. Matrix metalloproteinases 2 and 9 activity in the presence of serum, FFP, FTCP, or Solcoseryl(™) was assayed using a commercially available fluorogenic gelatinase activity kit. Matrix metalloproteinases 2 activity in the presence of serum, FFP, FTCP, and Solcoseryl(™) was 20.84%, 5.76%, 8.10%, and 83.03%, respectively of uninhibited MMP 2 activity. MMP 9 activity in the presence of serum, FFP, FTCP, and Solcoseryl(™) was 57.36%, 58.35%, 49.35%, and -8.69%, respectively of uninhibited MMP 9 activity. Serum, FFP, and FTCP exhibit similar levels of MMP 2 and 9 inhibitions. Solcoseryl(™) causes minimal MMP 2 inhibition, but profound MMP 9 inhibition. © 2014 American College of Veterinary Ophthalmologists.

  10. Characterization of Mexican coriander (Eryngium foetidum) essential oil and its inactivation of Listeria monocytogenes in vitro and during mild thermal pasteurization of pineapple juice.

    Science.gov (United States)

    Ngang, Jean J Essia; Nyegue, Maximilienne A; Ndoye, Foe C; Tchuenchieu Kamgain, Alex D; Sado Kamdem, Sylvain L; Lanciotti, Rosalba; Gardini, Fausto; Etoa, François-Xavier

    2014-03-01

    The aim of this work was to characterize the essential oil (EO) of Eryngium foetidum (EfEO) and assess its activity toward Listeria monocytogenes in broth and during thermal inactivation of the pathogen in pineapple juice. In this respect, EfEO was chemically characterized, and its antilisteria potential in broth as a function of pH, cell load, and EfEO concentration was assessed through a central composite design. Furthermore, the inactivation kinetics of L. monocytogenes in the juice were assessed by combining EfEO and low pasteurization temperatures. A total of 81 compounds were identified from EfEO. The reduction of pH and cell load increased EO activity. The use of only 15 ppm of EfEO during pasteurization of pineapple juice at 60°C reduced the time required for a 4-log reduction in L. monocytogenes CFU/ml by 74.9% (i.e., from 8.5 to 2.1 min) compared with treatment without EfEO. It could be concluded that EfEO activity toward L. monocytogenes increases with the reduction of pH and that it can be used at sublethal concentrations in combination with low temperatures in pineapple juice pasteurization. This study demonstrates that EO-assisted pasteurization is a promising strategy for the reduction of thermal impact during juice production. EfEO is easily available and compatible with many juices and is thus promising for industrial application.

  11. Inactivation Data.xlsx

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data set is a spreadsheet that contains results of inactivation experiments that were conducted to to determine the effectiveness of chlorine in inactivating B....

  12. A feeder-free, human plasma-derived hydrogel for maintenance of a human embryonic stem cell phenotype in vitro

    Directory of Open Access Journals (Sweden)

    Lewis Fiona C

    2012-08-01

    Full Text Available Abstract Background Human embryonic stem cells (hESCs represent a tremendous resource for cell therapies and the study of human development; however to maintain their undifferentiated state in vitro they routinely require the use of mouse embryonic fibroblast (MEF feeder-layers and exogenous protein media supplementation. Results These well established requirements can be overcome and in this study, it will be demonstrated that phenotypic stability of hESCs can be maintained using a novel, human plasma protein-based hydrogel as an extracellular culture matrix without the use of feeder cell co-culture. hESCs were resuspended in human platelet poor plasma (PPP, which was gelled by the addition of calcium containing DMEM-based hESC culture medium. Phenotypic and genomic expression of the pluripotency markers OCT4, NANOG and SOX2 were measured using immunohistochemistry and qRT-PCR respectively. Typical hESC morphology was demonstrated throughout in vitro culture and both viability and phenotypic stability were maintained throughout extended culture, up to 25 passages. Conclusions PPP-derived hydrogel has demonstrated to be an efficacious alternative to MEF co-culture with its hydrophilicity allowing for this substrate to be delivered via minimally invasive procedures in a liquid phase with polymerization ensuing in situ. Together this provides a novel technique for the study of this unique group of stem cells in either 2D or 3D both in vitro and in vivo.

  13. Effect of gamma, ethylene oxide, electron beam, and plasma sterilization on the behaviour of SR-PLLA fibres in vitro.

    Science.gov (United States)

    Nuutinen, Juha-Pekka; Clerc, Claude; Virta, Tuija; Törmälä, Pertti

    2002-01-01

    The aim of this study was to evaluate the effect of various sterilization processes on the physical and mechanical properties of self-reinforced bioabsorbable fibres made out of polylactide (PLLA). The samples were sterilized using plasma, ethylene oxide (one and two cycles), gamma (25 kGy at room temperature, 25 kGy in dry ice, and 2 x 25 kGy at room temperature), and electron beam (15, 25, and 55 kGy) sterilization. The intrinsic viscosity, crystallinity, and mechanical properties (modulus of elasticity, yield strength, and ultimate tensile strength) were tested before and immediately after each sterilization treatment, as well as up to 30 weeks in vitro. Compared with unsterilized fibres, the intrinsic viscosity was markedly decreased after radiation sterilization (gamma and electron beam) and the loss in mechanical properties was accelerated during in vitro degradation. Plasma and ethylene oxide (one and two cycles) did not markedly alter the properties of the samples after sterilization or during in vitro degradation. These data are important for determining the effect of various sterilization processes on the physical and mechanical properties of polylactide-based materials and can be used to predict how fast degradation of the mechanical properties of the self-reinforced PLLA will occur. They can also be used to tailor the degradation kinetics to optimize implant design.

  14. Modeling of human factor Va inactivation by activated protein C

    Directory of Open Access Journals (Sweden)

    Bravo Maria

    2012-05-01

    Full Text Available Abstract Background Because understanding of the inventory, connectivity and dynamics of the components characterizing the process of coagulation is relatively mature, it has become an attractive target for physiochemical modeling. Such models can potentially improve the design of therapeutics. The prothrombinase complex (composed of the protease factor (FXa and its cofactor FVa plays a central role in this network as the main producer of thrombin, which catalyses both the activation of platelets and the conversion of fibrinogen to fibrin, the main substances of a clot. A key negative feedback loop that prevents clot propagation beyond the site of injury is the thrombin-dependent generation of activated protein C (APC, an enzyme that inactivates FVa, thus neutralizing the prothrombinase complex. APC inactivation of FVa is complex, involving the production of partially active intermediates and “protection” of FVa from APC by both FXa and prothrombin. An empirically validated mathematical model of this process would be useful in advancing the predictive capacity of comprehensive models of coagulation. Results A model of human APC inactivation of prothrombinase was constructed in a stepwise fashion by analyzing time courses of FVa inactivation in empirical reaction systems with increasing number of interacting components and generating corresponding model constructs of each reaction system. Reaction mechanisms, rate constants and equilibrium constants informing these model constructs were initially derived from various research groups reporting on APC inactivation of FVa in isolation, or in the presence of FXa or prothrombin. Model predictions were assessed against empirical data measuring the appearance and disappearance of multiple FVa degradation intermediates as well as prothrombinase activity changes, with plasma proteins derived from multiple preparations. Our work integrates previously published findings and through the cooperative

  15. In vitro photodynamic inactivation effects of cationic benzylidene cyclopentanone photosensitizers on clinical fluconazole-resistant Candida albicans planktonic cells and biofilms

    Science.gov (United States)

    Zhou, Shaona; Fang, Yanyan; Ye, Zulin; Wang, Ying; Zhao, Yuxia; Gu, Ying

    2016-10-01

    Background: An increasing prevalence of Candida infections has emerged with the wide use of immune-suppressants and antibiotics. Photodynamic inactivation (PDI) as a new approach to treat localized Candida infections is an emerging and promising field nowadays. This study evaluated the efficacy of photodynamic therapy using two new Cationic benzylidene cyclopentanone photosensitizers(P1 and P2) against strains of clinical fluconazole-resistant Candida albicans. Methods: Suspensions and biofilms of Candida species were incubated with P1 and P2 concentrations (0.25 50 μM) for 30 min followed by 532nm laser irradiation. For planktonic suspensions, viability of cells was assayed by CFU counting. For biofilms, the metabolic activity was evaluated by XTT. Results: In PDI of a planktonic culture of clinical fluconazole-resistant Candida albicans, P2 showed the higher efficacy. After incubation with 25 μM of P2 for 30 min and irradiation with 532nm laser (36 J cm-2), the viability of C. albicans planktonic cells decreased by 3.84 log10. For biofilm cells, a higher light dose of 75 mW cm-2 was necessary to achieve 97.71% metabolic activity reduction. Conclusions: The results of this investigation demonstrated that benzylidene cyclopentanone photosensitizer, P2, is an efficient photosensitizer to kill C. albicans. Moreover, single-species biofilms were less susceptible to PDT than their planktonic counterparts.

  16. An in vitro investigation of bacteria-osteoblast competition on oxygen plasma-modified PEEK

    NARCIS (Netherlands)

    Rochford, Edward T. J.; Subbiahdoss, Guruprakash; Moriarty, T. Fintan; Poulsson, Alexandra H. C.; van der Mei, Henny C.; Busscher, Henk J.; Richards, R. Geoff

    2014-01-01

    Polyetheretherketone (PEEK) films were oxygen plasma treated to increase surface free energy and characterized by X-ray photoelectron microscopy, atomic force microscopy, and water contact angles. A parallel plate flow chamber was used to measure Staphylococcus epidermidis, Staphylococcus aureus,

  17. In vitro study of the effects of radio frequency generated for plasma in neoplastic cells HT-29; Estudo in vitro dos efeitos da radiofrequencia gerada por plasmas em celulas neoplasicas HT-29

    Energy Technology Data Exchange (ETDEWEB)

    Andrighetto, Daniela; Dornelles, Eduardo Bortoluzzi; Cruz, Ivana Beatrice Manica da; Lüdke, Everton, E-mail: daniela.andrighetto@hotmail.com, E-mail: dornellesedu@gmail.com, E-mail: ibmcruz@hotmail.com, E-mail: evertonludke@gmail.com [Universidade Federal de Santa Maria (UFSM), RS (BRazil)

    2014-07-01

    The goal of this study is to develop an in vitro irradiation cell system with controllable irradiation intensities of 27 MHz produced by an argon plasma column with variable amplitude modulation in the 100-700 kHz range. This paper presents and discusses a proposed experiment, with toxicity analysis (DNA Picogreen®) and cell viability (MTT assay) in the radiation-induced HT-29 cell line (colon adenocarcinoma). The data allow us to observe that cellular toxicity effects may occur with exposure to fields produced by argon plasma with intensities on the order of at least 3.2 W / cm2 and exposure times above 3.5 hours continuously. An analysis of cell populations for cell toxicity tests using the Student's t-test did not show significant changes (p <0.05) in the amount of DNA released by the action of radiofrequency, although it has been found that cell viability (MTT) is not significantly altered by long exposures to radiation induced plasma RF signals in 27 MHz (p> 0.34). Cytotoxic effects due to the destruction of cell wall by heating the samples were not detected in any of the tests.

  18. In vitro cell-biological performance and structural characterization of selective laser sintered and plasma surface functionalized polycaprolactone scaffolds for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Van Bael, Simon, E-mail: simon.vanbael@mech.kuleuven.be [Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Department of Mechanical Engineering, Division of Biomechanics and Engineering Design, Katholieke Universiteit Leuven, Celestijnenlaan 300c, bus 2419, 3001 Heverlee (Belgium); Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, bus 813, 3000 Leuven (Belgium); Desmet, Tim [Polymer Chemistry and Biomaterials Research Group, Ghent University, Krijgslaan 281 S4 Bis, Ghent, 9000 (Belgium); Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); Chai, Yoke Chin [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, bus 813, 3000 Leuven (Belgium); Pyka, Gregory [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, bus 813, 3000 Leuven (Belgium); Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, bus 2450, 3001 Leuven (Belgium); Dubruel, Peter [Polymer Chemistry and Biomaterials Research Group, Ghent University, Krijgslaan 281 S4 Bis, Ghent, 9000 (Belgium); Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); Kruth, Jean-Pierre [Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Schrooten, Jan [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, bus 813, 3000 Leuven (Belgium)

    2013-08-01

    In the present study a structural characterization and in vitro cell-biological evaluation was performed on polycaprolactone (PCL) scaffolds that were produced by the additive manufacturing technique selective laser sintering (SLS), followed by a plasma-based surface modification technique, either non-thermal oxygen plasma or double protein coating, to functionalize the PCL scaffold surfaces. In the first part of this study pore morphology by means of 2D optical microscopy, surface chemistry by means of hydrophilicity measurement and X-ray photoelectron spectroscopy, strut surface roughness by means of 3D micro-computed tomography (CT) imaging and scaffold mechanical properties by means of compression testing were evaluated before and after the surface modifications. The results showed that both surface modifications increased the PCL scaffold hydrophilicity without altering the morphological and mechanical properties. In the second part of this study the in vitro cell proliferation and differentiation of human osteoprogenitor cells, over 14 days of culture in osteogenic and growth medium were investigated. The O{sub 2} plasma modification gave rise to a significant lower in vitro cell proliferation compared to the untreated and double protein coated scaffolds. Furthermore the double protein coating increased in vitro cell metabolic activity and cell differentiation compared to the untreated and O{sub 2} plasma PCL scaffolds when OM was used. - Highlights: • Polycaprolactone scaffolds are produced with selective laser sintering. • 2 types of plasma based surface functionalization were applied. • Plasma had no significant effect on strut roughness and pore morphology. • Plasma improved surface hydrophilicity. • In vitro cell differentiation increased with plasma protein coated functionalization.

  19. A new approach for studying GPCR dimers: drug-induced inactivation and reactivation to reveal GPCR dimer function in vitro, in primary culture, and in vivo

    Science.gov (United States)

    Teitler, Milt; Klein, Michael T.

    2011-01-01

    GPCRs are a major family of homologous proteins and are key mediators of the effects of numerous endogenous neurotransmitters, hormones, cytokines, therapeutic drugs, and drugs-of-abuse. Despite the enormous amount of research on the pharmacological and biochemical properties of GPCRs, the question as to whether they exist as monomers, dimers, or higher order structures in the body is unanswered. The GPCR dimer field has been dominated by techniques involving recombinant cell lines expressing mutant receptors, often involving the solubilization of the receptors. These techniques cannot be applied in vivo or even to primary cell cultures. This review will focus on a novel approach to exploring the functional properties of homodimers. Studies of the 5-HT7 and 5-HT2A serotonin receptors have revealed that binding of a pseudo-irreversible antagonist (“inactivator”) to one of the orthosteric sites of a homodimer abolishes all receptor activity, and subsequent binding of a competitive antagonist to the orthosteric site of the second protomer releases the inactivator, allowing the receptor to return to an active state. This approach demonstrates allosteric crosstalk between protomers of native GPCR homodimers, indicating that GPCRs do exist and function as homodimers in both recombinant cells and rat primary astrocytes. This technique can be applied universally using intact recombinant or primary cells in culture, membrane homogenate preparations and, potentially, in vivo. The data obtained using the 5-HT7 and 5-HT2A receptors are strongly supportive of a GPCR homodimer structure, with little evidence of monomer involvement in the function of these receptors. PMID:22119169

  20. Packaging materials for plasma sterilization with the flowing afterglow of an N{sub 2}-O{sub 2} discharge: damage assessment and inactivation efficiency of enclosed bacterial spores

    Energy Technology Data Exchange (ETDEWEB)

    Levif, P; Moisan, M; Soum-Glaude, A [Groupe de Physique des Plasmas, Universite de Montreal, CP 6128, Succursale Centre-Ville, Montreal H3C 3J7, Quebec (Canada); Seguin, J; Barbeau, J, E-mail: michel.moisan@umontreal.ca [Faculte de Medecine Dentaire, Laboratoire de Controle des Infections, Universite de Montreal, CP 6128, Montreal H3C 3J7, Quebec (Canada)

    2011-10-12

    In conventional sterilization methods (steam, ozone, gaseous chemicals), after their proper cleaning, medical devices are wrapped/enclosed in adequate packaging materials, then closed/sealed before initiating the sterilization process: these packaging materials thus need to be porous. Gaseous plasma sterilization being still under development, evaluation and comparison of packaging materials have not yet been reported in the literature. To this end, we have subjected various porous packagings used with conventional sterilization systems to the N{sub 2}-O{sub 2} flowing afterglow and also a non-porous one to evaluate and compare their characteristics towards the inactivation of B. atrophaeus endospores deposited on a Petri dish and enclosed in such packagings. Because the sterilization process with the N{sub 2}-O{sub 2} discharge afterglow is conducted under reduced-pressure conditions, non-porous pouches can be sealed only after returning to atmospheric pressure. All the tests were therefore conducted with one end of the packaging freely opened, post-sealing being required. The features of these packaging materials, namely mass loss, resistance, toxicity to human cells as well as some characteristics specific to the plasma method used such as ultraviolet transparency, were examined before and after exposure to the flowing afterglow. All of our results show that the non-porous packaging considered is much more suitable than the conventionally used porous ones as far as ensuring an efficient and low-damage sterilization process with an N{sub 2}-O{sub 2} plasma-afterglow is concerned.

  1. In vitro bioaccessibility, bioavailability and plasma protein interaction of polyphenols from Annurca apple (M. pumila Miller cv Annurca).

    Science.gov (United States)

    Tenore, Gian Carlo; Campiglia, Pietro; Ritieni, Alberto; Novellino, Ettore

    2013-12-15

    The in vitro bioaccessibility, bioavailability and plasma protein interaction of polyphenols from Annurca apple and other conventional cultivars were evaluated. Salivary digestion concentrated into the medium 27-35% of native apple polyphenols, suggesting the potential bioavailability through the oral mucosal epithelium of significant amounts of bioactive compounds that could be gastric sensitive and/or poorly absorbed in the intestine. Annurca flesh revealed the highest content and provided the best intestinal bioaccessibility and bioavailability of oligomeric procyanidins among all of the apple peel and flesh tested. Since 49.4% of native procyanidins were not absorbed, they are expected to accumulate in the intestinal lumen where a potential inhibition capacity of cellular cholesterol uptake could be assumed. The permeated procyanidins (6.7% of their native pattern, 12.0% of intestinal procyanidins) significantly bound (58.7%) to plasma HDLs, suggesting a major role in cholesterol metabolism. Our results would indicate Annurca apple and its potential nutraceuticals as effective in the regulation of plasma cholesterol levels. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. In vitro variables of apheresis platelets are stably maintained for 7 days with 5% residual plasma in a glucose and bicarbonate salt solution, PAS-5.

    Science.gov (United States)

    Radwanski, Katherine; Wagner, Stephen J; Skripchenko, Andrey; Min, Kyungyoon

    2012-01-01

    Platelet additive solutions (PASs) facilitate improved recovery of plasma and may reduce the severity and/or frequency of plasma-associated transfusion reactions. Current apheresis platelet (PLT) PAS products contain approximately 30 to 40% residual plasma. In an effort to further decrease the residual plasma, two in vitro studies were conducted with PLTs suspended in 5% plasma and a reformulated PAS-3, named PAS-5, that contains additional salts, glucose, and bicarbonate. In Study 1, PLTs suspended in 5% plasma/95% PAS-5 were prepared directly on a separator (Amicus, Fenwal, Inc.) without additional centrifugation or washing. In Study 2, a double unit of hyperconcentrated Amicus PLTs in plasma was collected, divided, and centrifuged to prepare a control unit in 100% plasma and a paired test unit in 5% plasma/95% PAS-5. The in vitro properties of PLTs were assessed in both studies during 7-day storage at 20 to 24°C with continuous agitation. In Study 1, PLT concentration, pH, mean PLT volume (MPV), HCO(3)(-), pCO(2), pO(2), lactate dehydrogenase, and hypotonic shock response (HSR) did not significantly change during storage. By Day 7, glucose levels and morphology scores modestly decreased (17.6 and 14.4%, respectively) and lactate levels modestly increased (to 7.2 mmol/L). In Study 2, MPV, pH, glucose, pO(2), HSR, and morphology were comparable in control and test PLTs during 7-day storage. Glucose consumption and lactate production were significantly less in test versus control PLTs (p≤0.0015). Extent of shape change and %CD62P-positive test PLTs were less than those of controls (p<0.001). Apheresis PLTs suspended in 5% plasma/95% PAS-5 maintained in vitro properties during 7-day storage. © 2011 American Association of Blood Banks.

  3. Studies on the mechanism of capacitation: albumin-mediated changes in plasma membrane lipids during in vitro incubation of rat sperm cells.

    OpenAIRE

    Davis, B K; R. Byrne; Bedigian, K

    1980-01-01

    Plasma membrane isolated from rat sperm cells after incubation in vitro had a significantly lower cholesterol/phospholipid mole ratio when the medium contained serum albumin. Transfer of albumin-bound phospholipids to the membrane can largely account for this effect. The result is broadly consistent with a previously proposed model for albumin-induced destabilization of sperm membrane (capacitation) and its reversal by seminal plasma membrane vesicles. Albumin also decreased sialic acid and, ...

  4. In vitro Heparin Precipitation in the Plasma of Euthyroid women with ...

    African Journals Online (AJOL)

    And history of recurrent miscarriage associated with auto antibodies have had a high rate of life births in subsequent pregnancies when they were treated with low dose aspirin together with low dose heparin. An in-vitro assay thus provide basis for the intricate interaction. DESIGN: Two hundred and ten (210) healthy ...

  5. The effects of plasma electrolytically oxidized NiTi on in vitro endothelialization

    NARCIS (Netherlands)

    Huan, Z.; Yu, H.; Li, H.; Ruiter, M. S.; Chang, J.; Apachitei, I.; Duszczyk, J.; de Vries, C. J. M.; Fratila-Apachitei, L. E.

    2016-01-01

    The role of biomaterials surface in controlling the interfacial biological events leading to implant integration is of key importance. In this study, the effects of NiTi surfaces treated by plasma electrolytic oxidation (PEO) on human umbilical vein endothelial cells (HUVECs) have been investigated.

  6. Enhanced Biological Behavior of In Vitro Human Gingival Fibroblasts on Cold Plasma-Treated Zirconia

    Science.gov (United States)

    Zheng, Miao; Yang, Yang; Liu, Xiao-Qiang; Liu, Ming-Yue; Zhang, Xiao-Fei; Wang, Xin; Li, He-Ping; Tan, Jian-Guo

    2015-01-01

    Objective To evaluate whether atmospheric-pressure dielectric-barrier-discharge plasma treatment of zirconia enhances its biocompatibility with human gingival fibroblasts. Materials and Methods The zirconia disks were divided into four groups and treated using helium atmospheric-pressure dielectric-barrier-discharge plasmas for 30, 60 or 90 s or left untreated. The surface morphology, wettability and chemical elements were analyzed. Fibroblasts density, morphology, morphometry and attachment-related genes expression were measured at different time points from 3 to 72 h. Results After plasma treatment, the surface morphology and roughness remained the same, while the contact angle decreased from 78.31° to 43.71°, and the surface C/O ratio decreased from 3.17 to 0.89. The surficial areas and perimeters of HGFs were increased two-fold in the treated groups at 3 h. Fibroblasts density increased on treated disks at all time points, especially the ones treated for 60 s. Attachment-related genes in the groups treated for 30 and 60 s were significantly higher at 3 and 24 h. Conclusion The helium atmospheric-pressure dielectric-barrier-discharge plasma treatment enhances the biological behavior of fibroblasts on zirconia by increasing the expression of attachment-related genes within 24 h and promoting the cell density during longer culture times. Wettability of zirconia, an important physicochemical property, has a vital influence on the cell behaviors. PMID:26461253

  7. In vitro Heparin Precipitation in the Plasma of Euthyroid women with ...

    African Journals Online (AJOL)

    Antimicrosomal autoantibody (Anti-TPO) ELISA assay was determined. The plasma treatment at the different PH with heparin and aspirin in physiological buffers were carried out. RESULT: At PH5.0 (i.e. the Uterus physiological PH) using 100i.u/ml heparin in 0.2M acetate buffer yielded 70% precipitate compared to ...

  8. Inactivation of Bacillus atrophaeus by OH radicals

    Science.gov (United States)

    Ono, Ryo; Yonetamari, Kenta; Tokumitsu, Yusuke; Yonemori, Seiya; Yasuda, Hachiro; Mizuno, Akira

    2016-08-01

    The inactivation of Bacillus atrophaeus by OH radicals is measured. This study aims to evaluate the bactericidal effects of OH radicals produced by atmospheric-pressure nonthermal plasma widely used for plasma medicine; however, in this study, OH radicals are produced by vacuum ultraviolet (VUV) photolysis of water vapor instead of plasma to allow the production of OH radicals with almost no other reactive species. A 172 nm VUV light from a Xe2 excimer lamp irradiates a He-H2O mixture flowing in a quartz tube to photodissociate H2O to produce OH, H, O, HO2, H2O2, and O3. The produced reactive oxygen species (ROS) flow out of the quartz tube nozzle to the bacteria on an agar plate and cause inactivation. The inactivation by OH radicals among the six ROS is observed by properly setting the experimental conditions with the help of simulations calculating the ROS densities. A 30 s treatment with approximately 0.1 ppm OH radicals causes visible inactivation.

  9. Evaluation of the safety, immunogenicity, and protective efficacy of whole inactivated simian immunodeficiency virus (SIV) vaccines with conformationally and functionally intact envelope glycoproteins.

    Science.gov (United States)

    Lifson, Jeffrey D; Rossio, Jeffrey L; Piatak, Michael; Bess, Julian; Chertova, Elena; Schneider, Douglas K; Coalter, Vicky J; Poore, Barbara; Kiser, Rebecca F; Imming, Robert J; Scarzello, Anthony J; Henderson, Louis E; Alvord, W Gregory; Hirsch, Vanessa M; Benveniste, Raoul E; Arthur, Larry O

    2004-07-01

    A novel, general approach to chemical inactivation of retroviruses was used to produce inactivated simian immunodeficiency virus (SIV) particles with functional envelope glycoproteins. Inactivated virions of three different virus isolates (SIVmne E11S, SIVmac239, and SIVmac239 g4,5), prepared by treatment with 2,2'-dithiodipyridine (aldrithol-2, AT-2), were not detectably infectious, in vitro or in vivo. Immunization of pigtailed macaques with inactivated SIVmne E11S particles, without adjuvant, induced both humoral and cellular immune responses. Four of six animals immunized with the inactivated particles did not show measurable SIV RNA in plasma (virus (SIVmne E11S), compared to peak values of > or =10(6) copy Eq/ml in challenged SIV-naive control animals (p = 0.0001). Despite the absence of measurable viral RNA in plasma in these animals, culturable virus and viral DNA were initially detectable in blood and lymph node specimens; in contrast to control animals, SIV DNA could no longer be detected in PBMC by 10 weeks postchallenge in five of six SIV-immunized animals (p = 0.0001). However, vaccines did not resist a sequential rechallenge with the heterologous pathogenic virus SIVsm E660. AT-2-inactivated virus with functional envelope glycoproteins is a novel class of vaccine immunogen and was noninfectious, under conditions of rigorous in vivo challenge, and induced both binding and neutralizing antibody responses, along with cellular immune responses. Results suggest that immunization facilitated effective containment of pathogenic homologous challenge virus. With further optimization, AT-2-inactivated viral particles may be a useful class of immunogen in the development of a vaccine to prevent AIDS.

  10. In vitro evaluation of cell proliferation and collagen synthesis on titanium following plasma electrolytic oxidation.

    Science.gov (United States)

    Whiteside, Paul; Matykina, Endzhe; Gough, Julie E; Skeldon, Peter; Thompson, George E

    2010-07-01

    Titania-based coatings produced by plasma electrolytic oxidation are being investigated as bioactive surfaces for titanium implants. In this study, plasma electrolytic oxidation was performed in calcium- and phosphorus-based electrolytes under DC conditions, resulting in coatings of thickness of approximately 8-15 mum. Coating morphologies, microstructures, and compositions were examined by scanning electron microscopy with energy-dispersive X-ray analysis, X-ray diffraction, and electron probe microanalysis. The coatings revealed a cratered morphology, with incorporated calcium and phosphorus species. Proliferation rates of primary human osteoblasts cells on the coatings were up to approximately 37% faster than those for uncoated titanium and 316L stainless steel reference materials. Further, the coatings assisted cell adhesion and generation and anchorage of collagen. The amount of collagen was upto approximately 2.4 times greater than for the reference substrates. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.

  11. In vitro lingual bracket evaluation of indirect bonding with plasma arc, LED and halogen light.

    Science.gov (United States)

    Magno, A F F; Martins, R P; Vaz, L G; Martins, L P

    2010-02-01

    Evaluate the shear bond strength (SBS) and the adhesive remnant index (ARI) of indirect bonded lingual brackets using xenon plasma arc light, light-emitting diode (LED) and conventional quartz-tungsten-halogen light. Lingual brackets were bonded indirectly to 60 premolars divided to three groups according to the curing light used: Group 1, plasma arc for 6 s; Group 2, LED for 10 s; and Group 3, halogen light for 40 s. After bonding, the specimens were subjected to a shear force until debonding. The debonding pattern was assessed and classified according to the ARI scores. The mean shear bond strengths were accessed by anova followed by the Student-Newman-Keuls test for multiple comparisons. ARI scores were assessed using the chi-square test. The three groups showed significant differences (p plasma arc, during 60% of the time used for the LED, produced lower SBS than obtained with the latter. Using LED during 25% of the time of the halogen light produced lower SBS than obtained with the latter. These differences did not influence the debonding pattern and are clinically acceptable according to the literature.

  12. In vitro study of thimerosal reactions in human whole blood and plasma surrogate samples.

    Science.gov (United States)

    Trümpler, Stefan; Meermann, Björn; Nowak, Sascha; Buscher, Wolfgang; Karst, Uwe; Sperling, Michael

    2014-04-01

    Because of its bactericidal and fungicidal properties, thimerosal is used as a preservative in drugs and vaccines and is thus deliberately injected into the human body. In aqueous environment, it decomposes into thiosalicylic acid and the ethylmercury cation. This organomercury fragment is a potent neurotoxin and is suspected to have similar toxicity and bioavailability like the methylmercury cation. In this work, human whole blood and physiological simulation solutions were incubated with thimerosal to investigate its behaviour and binding partners in the blood stream. Inductively coupled plasma with optical emission spectrometry (ICP-OES) was used for total mercury determination in different blood fractions, while liquid chromatography (LC) coupled to electrospray ionisation time-of-flight (ESI-TOF) and inductively coupled plasma-mass spectrometry (ICP-MS) provided information on the individual mercury species in plasma surrogate samples. Analogous behaviour of methylmercury and ethylmercury species in human blood was shown and an ethylmercury-glutathione adduct was identified. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. In vitro cell-biological performance and structural characterization of selective laser sintered and plasma surface functionalized polycaprolactone scaffolds for bone regeneration.

    Science.gov (United States)

    Van Bael, Simon; Desmet, Tim; Chai, Yoke Chin; Pyka, Gregory; Dubruel, Peter; Kruth, Jean-Pierre; Schrooten, Jan

    2013-08-01

    In the present study a structural characterization and in vitro cell-biological evaluation was performed on polycaprolactone (PCL) scaffolds that were produced by the additive manufacturing technique selective laser sintering (SLS), followed by a plasma-based surface modification technique, either non-thermal oxygen plasma or double protein coating, to functionalize the PCL scaffold surfaces. In the first part of this study pore morphology by means of 2D optical microscopy, surface chemistry by means of hydrophilicity measurement and X-ray photoelectron spectroscopy, strut surface roughness by means of 3D micro-computed tomography (CT) imaging and scaffold mechanical properties by means of compression testing were evaluated before and after the surface modifications. The results showed that both surface modifications increased the PCL scaffold hydrophilicity without altering the morphological and mechanical properties. In the second part of this study the in vitro cell proliferation and differentiation of human osteoprogenitor cells, over 14 days of culture in osteogenic and growth medium were investigated. The O2 plasma modification gave rise to a significant lower in vitro cell proliferation compared to the untreated and double protein coated scaffolds. Furthermore the double protein coating increased in vitro cell metabolic activity and cell differentiation compared to the untreated and O2 plasma PCL scaffolds when OM was used. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Effects of exposure of epididymal boar spermatozoa to seminal plasma on the binding of zona pellucida proteins during in vitro capacitation

    NARCIS (Netherlands)

    Harkema, W.; Colenbrander, B.; Engel, B.; Woelders, H.

    2004-01-01

    The purpose of the investigation was to determine whether seminal plasma plays a role in the increase during in vitro capacitation of the number of boar spermatozoa with enhanced binding of zona pellucida proteins. Ejaculated spermatozoa and spermatozoa collected from the caudae epididymides of

  15. Efecto inhibidor del crecimiento bacteriano in vitro del plasma rico en plaquetas

    OpenAIRE

    Huapaya Lazo, Carlos Enrique; Noriega Castañeda, Jorge

    2008-01-01

    Objetivo: determinar el efecto inhibidor del crecimiento bacteriano del Plasma Rico en Plaquetas (PRP) sobre el Estafilococo aureus. Material y método: se tomó 20cc de sangre a cada uno de los cinco pacientes que intervinieron en el estudio, obteniéndose el PRP activado con trombina y bovina en cada una de las muestras. Se realizaron dos procedimientos diferentes, procesándose cada muestra por quintuplicado. En el primero se enfrenta el PRP puro y combinado con Ampicilina 500mg con el Estafil...

  16. Inactivation of insulin-like-growth factors diminished the anabolic effects of pregnancy-associated plasma protein-A (PAPP-A) on bone in mice.

    Science.gov (United States)

    Phang, David; Rehage, Mark; Bonafede, Blake; Hou, Diana; Xing, Weirong; Mohan, Subburaman; Wergedal, Jon E; Qin, Xuezhong

    2010-06-01

    In vivo studies have provided ubiquitous evidence that pregnancy-associated plasma protein-A (PAPP-A) functions as a potent anabolic factor. While some evidence supports the prediction that increasing IGF bioavailability contributes to the anabolic effects of PAPP-A, definitive evidence has been lacking. This important issue has been addressed in this study using a unique mouse model in which PAPP-A was overexpressed in bone either alone or together with a protease-resistant IGFBP-4 analog (PRBP-4) which serves as an IGF inhibitor. PAPP-A transgenic mice exhibited a 25% increase in skull bone mineral density (BMD) whereas PRBP-4 transgenic mice showed a 20-25% decrease in this parameter at an age of 3months. Femur/tibia size-related parameters were significantly increased in PAPP-A transgenic mice but decreased in PRBP-4 transgenic mice. This data clearly demonstrates that PAPP-A transgenic mice exhibit opposite phenotypes in both flat bone and long bone compared to PRBP-4 transgenic mice which have reduced IGF bioavailability in bone. Importantly, PRBP-4 and PRBP-4/PAPP-A double transgenic mice shared essentially identical phenotypes in both flat and long bones. Calvarial thickness, skull BMD and long bone parameters were reduced to similar degrees in PRBP-4 and PRBP-4/PAPP-A transgenic mice relative to wild-type littermates. Our findings provide compelling evidence that PAPP-A increases bone formation primarily by increasing IGF bioavailability and that other alternative pathways may play a negligible role in mediating the anabolic effect of PAPPA in bone. This clear definition of PAPP-A's mechanism of action is critical for future translational studies on the therapeutic application of PAPP-A. Copyright 2010 Elsevier Ltd. All rights reserved.

  17. In vitro, in silico and integrated strategies for the estimation of plasma protein binding. A review.

    Science.gov (United States)

    Lambrinidis, George; Vallianatou, Theodosia; Tsantili-Kakoulidou, Anna

    2015-06-23

    Plasma protein binding (PPB) strongly affects drug distribution and pharmacokinetic behavior with consequences in overall pharmacological action. Extended plasma protein binding may be associated with drug safety issues and several adverse effects, like low clearance, low brain penetration, drug-drug interactions, loss of efficacy, while influencing the fate of enantiomers and diastereoisomers by stereoselective binding within the body. Therefore in holistic drug design approaches, where ADME(T) properties are considered in parallel with target affinity, considerable efforts are focused in early estimation of PPB mainly in regard to human serum albumin (HSA), which is the most abundant and most important plasma protein. The second critical serum protein α1-acid glycoprotein (AGP), although often underscored, plays also an important and complicated role in clinical therapy and thus the last years it has been studied thoroughly too. In the present review, after an overview of the principles of HSA and AGP binding as well as the structure topology of the proteins, the current trends and perspectives in the field of PPB predictions are presented and discussed considering both HSA and AGP binding. Since however for the latter protein systematic studies have started only the last years, the review focuses mainly to HSA. One part of the review highlights the challenge to develop rapid techniques for HSA and AGP binding simulation and their performance in assessment of PPB. The second part focuses on in silico approaches to predict HSA and AGP binding, analyzing and evaluating structure-based and ligand-based methods, as well as combination of both methods in the aim to exploit the different information and overcome the limitations of each individual approach. Ligand-based methods use the Quantitative Structure-Activity Relationships (QSAR) methodology to establish quantitate models for the prediction of binding constants from molecular descriptors, while they provide

  18. In vivo and in vitro antibacterial activity of conglutinin, a mammalian plasma lectin

    DEFF Research Database (Denmark)

    Friis-Christiansen, P; Thiel, S; Svehag, S E

    1990-01-01

    Conglutinin is a mammalian C-type lectin which agglutinates iC3b-coated erythrocytes. Ingram [13] found that euglobulin from bovine serum may confer partial protection against experimental infections in mice. We now present evidence that the protective activity in euglobulin against infections...... of BALB/c mice with Salmonella typhimurium is mediated by conglutinin. Conglutinin also demonstrated antibacterial activity against E. coli and S. typhimurium in vitro. The expression of this activity required the presence of heat-labile serum factors and peritoneal exudate or spleen cells......, but not antibodies to the bacteria. Antibacterial activity was also demonstrated when the bacteria were pretreated with serum at 37 degrees C before incubation with conglutinin and cells. The activity of conglutinin was not observed when factor I-deficient or EDTA-treated serum was used instead of normal serum...

  19. Flavivirus infection from mosquitoes in vitro reveals cell entry at the plasma membrane

    Energy Technology Data Exchange (ETDEWEB)

    Vancini, Ricardo [Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC (United States); Kramer, Laura D. [Wadsworth Center, New York State Department of Health, and School of Public Health, State University of New York at Albany, Albany, NY (United States); Ribeiro, Mariana; Hernandez, Raquel [Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC (United States); Brown, Dennis, E-mail: dennis_brown@ncsu.edu [Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC (United States)

    2013-01-20

    Dengue and West Nile viruses are enveloped RNA viruses that belong to genus Flavivirus (family Flaviviridae) and are considered important mosquito-borne viral pathogenic agents worldwide. A potential target for intervention strategies is the virus cell entry mechanism. Previous studies of flavivirus entry have focused on the effects of biochemical and molecular inhibitors on viral entry leading to controversial conclusions suggesting that the process is dependent upon endocytosis and low pH mediated membrane fusion. In this study we analyzed the early events in the infection process by means of electron microscopy and immuno-gold labeling of viral particles during cell entry, and used as a new approach for infecting cells with viruses obtained directly from mosquitoes. The results show that Dengue and West Nile viruses may infect cells by a mechanism that involves direct penetration of the host cell plasma membrane as proposed for alphaviruses.

  20. Human CD38hiCD138+ Plasma Cells Can Be Generated In Vitro from CD40-Activated Switched-Memory B Lymphocytes

    Directory of Open Access Journals (Sweden)

    Rayelle Itoua Maïga

    2014-01-01

    Full Text Available B lymphocyte differentiation into long-lived plasma cells is the keystone event for the production of long-term protective antibodies. CD40-CD154 and CD27-CD70 interactions are involved in human B lymphocyte differentiation into CD38hiCD138+ cells in vivo as well as in vitro. In this study, we have compared these interactions in their capacity to drive switched-memory B lymphocytes differentiation into CD38hiCD138+ plasma cells. The targeted B lymphocytes were isolated from human peripheral blood, expanded for 19 days, and then submitted to CD70 or CD154 interactions for 14 days. The expanded B lymphocytes were constitutively expressing CD39, whereas CD31’s expression was noticed only following the in vitro differentiation step (day 5 and was exclusively present on the CD38hi cell population. Furthermore, the generated CD38hiCD138+ cells showed a higher proportion of CD31+ cells than the CD38hiCD138- cells. Besides, analyses done with human blood and bone marrow plasma cells showed that in vivo and de novo generated CD38hiCD138+ cells have a similar CD31 expression profile but are distinct according to their reduced CD39 expression level. Overall, we have evidences that in vitro generated plasma cells are heterogeneous and appear as CD39+ precursors to the ones present in bone marrow niches.

  1. Poly(hydroxyethyl methacrylate) based affinity membranes for in vitro removal of anti-dsDNA antibodies from SLE plasma.

    Science.gov (United States)

    Uzun, Lokman; Yavuz, Handan; Osman, Bilgen; Celik, Hamdi; Denizli, Adil

    2010-07-01

    The preparation of polymeric membrane using affinity technology for application in blood filtration devices is described here. DNA attached poly(hydroxyethyl methacrylate) (PHEMA) based microporous affinity membrane was prepared for selective removal of anti-dsDNA antibodies from systemic lupus erythematosus (SLE) patient plasma in in vitro. In order to further increase blood-compatibility of affinity membrane, aminoacid based comonomer N-methacryloyl-L-alanine (MAAL) was included in the polymerization recipe. PHEMAAL membrane was produced by a photopolymerization technique and then characterized by swelling tests and scanning electron microscope (SEM) studies. Blood-compatibility tests were also performed. The water swelling ratio of PHEMAAL membrane increased significantly (133.2%) compared with PHEMA (58%). PHEMAAL membrane has large pores around in the range of 5-10 microm. All the clotting times increased when compared with PHEMA membrane. Loss of platelets and leukocytes was very low. DNA loading was 7.8 mg/g. There was a very low anti-dsDNA-antibody adsorption onto the plain PHEMAAL membrane, about 78 IU/g. The PHEMAAL-DNA membrane adsorbed anti-dsDNA-antibody in the range of 10-68 x 10(3)IU/g from SLE plasma. Anti-dsDNA-antibody concentration decreased significantly from 875 to 144 IU/ml with the time. Anti-dsDNA-antibodies could be repeatedly adsorbed and eluted without noticeable loss in the anti-dsDNA-antibody adsorption amount. (c) 2010 Elsevier B.V. All rights reserved.

  2. The delayed dissolution of paracetamol products in the canine fed stomach can be predicted in vitro but it does not affect the onset of plasma levels.

    Science.gov (United States)

    Kalantzi, Lida; Polentarutti, Britta; Albery, Tamsin; Laitmer, Dimitris; Abrahamsson, Bertil; Dressman, Jennifer; Reppas, Christos

    2005-05-30

    Although it is generally believed that paracetamol can be used as a marker of gastric emptying, there have been reports in the literature that show delayed dissolution of immediate release paracetamol tablets using standard in vitro setups and food-simulating media, delayed disintegration of paracetamol products in the fed stomach, and no correlation of paracetamol absorption with gastric emptying in the fed state. In this study, we confirmed that dissolution of Panodil and Apotel tablets is delayed in food-simulating media regardless of the in vitro hydrodynamics and on a formulation dependent manner. Further, we assessed the usefulness of in vitro dissolution data in the prediction of delayed disintegration time in the fed stomach and we examined the importance of delayed gastric disintegration on the onset of plasma levels using the canine model. In vitro dissolution data in cow's milk reflected the delayed disintegration of Panodil tablets in the fed stomach. In vitro dissolution of Apotel tablets in milk was delayed less than of Panodil and the effect of dosing conditions on the in vivo disintegration was not apparent. However, for the products tested in this study, there was no correlation between intragastric disintegration and onset of plasma levels probably because gastric emptying in also delayed in the fed state.

  3. Fortification of blood plasma from cancer patients with human serum albumin decreases the concentration of cisplatin-derived toxic hydrolysis products in vitro.

    Science.gov (United States)

    Morris, Thomas T; Ruan, Yibing; Lewis, Victor A; Narendran, Aru; Gailer, Jürgen

    2014-11-01

    While cisplatin (CP) is still one of the world's bestselling anticancer drugs, its intravenous administration is inherently associated with severe, dose limiting toxic side-effects. Although the molecular basis of the latter are not well understood, biochemical transformations of CP in blood and the interaction of the generated platinum species with plasma proteins likely play a critical role since these processes will ultimately determine which platinum-species reach the intended tumor cells as well as non-target cells. Compared to healthy subjects, cancer patients often have decreased plasma human serum albumin (HSA) concentrations. Little, however, is known about how the plasma HSA concentration will affect the metabolism of CP. To gain insight, we obtained blood plasma from healthy adults (n = 20, 42 ± 4 g HSA per L) and pediatric cancer patients (n = 11, 26 ± 7 g HSA per L). After the incubation of plasma at 37 °C, a pharmacologically relevant dose of CP was added and the Pt-distribution therein was determined by size-exclusion chromatography coupled on-line to an inductively coupled plasma atomic emission spectrometer. At the 2 h time point, a 5.9% increase of toxic CP-derived hydrolysis products was detected in pediatric cancer patient plasma, while 9.8% less platinum was protein bound compared to plasma from healthy controls. These in vitro results suggest that the elevated concentration of highly reactive free CP-derived hydrolysis products in plasma may cause the toxic side-effects in cancer patients. More importantly, the deliberate increase of the plasma HSA concentration in cancer patients prior to CP treatment would represent a simple strategy to possibly alleviate the fraction of patients that suffer from drug induced toxic side-effects.

  4. Porous tantalum coatings prepared by vacuum plasma spraying enhance bmscs osteogenic differentiation and bone regeneration in vitro and in vivo.

    Science.gov (United States)

    Tang, Ze; Xie, Youtao; Yang, Fei; Huang, Yan; Wang, Chuandong; Dai, Kerong; Zheng, Xuebin; Zhang, Xiaoling

    2013-01-01

    Tantalum, as a potential metallic implant biomaterial, is attracting more and more attention because of its excellent anticorrosion and biocompatibility. However, its significantly high elastic modulus and large mechanical incompatibility with bone tissue make it unsuitable for load-bearing implants. In this study, porous tantalum coatings were first successfully fabricated on titanium substrates by vacuum plasma spraying (VPS), which would exert the excellent biocompatibility of tantalum and alleviate the elastic modulus of tantalum for bone tissue. We evaluated cytocompatibility and osteogenesis activity of the porous tantalum coatings using human bone marrow stromal cells (hBMSCs) and its ability to repair rabbit femur bone defects. The morphology and actin cytoskeletons of hBMSCs were observed via electron microscopy and confocal, and the cell viability, proliferation and osteogenic differentiation potential of hBMSCs were examined quantitatively by PrestoBlue assay, Ki67 immunofluorescence assay, real-time PCR technology and ALP staining. For in vivo detection, the repaired femur were evaluated by histomorphology and double fluorescence labeling 3 months postoperation. Porous tantalum coating surfaces promoted hBMSCs adhesion, proliferation, osteogenesis activity and had better osseointegration and faster new bone formation rate than titanium coating control. Our observation suggested that the porous tantalum coatings had good biocompatibility and could enhance osseoinductivity in vitro and promote new bone formation in vivo. The porous tantalum coatings prepared by VPS is a promising strategy for bone regeneration.

  5. Plasma carboxypeptidase U (CPU, CPB2, TAFIa) generation during in vitro clot lysis and its interplay between coagulation and fibrinolysis.

    Science.gov (United States)

    Leenaerts, Dorien; Aernouts, Jef; Van Der Veken, Pieter; Sim, Yani; Lambeir, Anne-Marie; Hendriks, Dirk

    2017-07-26

    Carboxypeptidase U (CPU, CPB2, TAFIa) is a basic carboxypeptidase that is able to attenuate fibrinolysis. The inactive precursor procarboxypeptidase U is converted to its active form by thrombin, the thrombin-thrombomodulin complex or plasmin. The aim of this study was to investigate and characterise the time course of CPU generation in healthy individuals. In plasma of 29 healthy volunteers, CPU generation was monitored during in vitro clot lysis. CPU activity was measured by means of an enzymatic assay that uses the specific substrate Bz-o-cyano-Phe-Arg. An algorithm was written to plot the CPU generation curve and calculate the parameters that define it. In all individuals, CPU generation was biphasic. Marked inter-individual differences were present and a reference range was determined. The endogenous CPU generation potential is the composite effect of multiple factors. With respect to the first CPU activity peak characteristics, we found correlations with baseline proCPU concentration, proCPU Thr325Ile polymorphism, time to clot initiation and the clot lysis time. The second CPU peak related with baseline proCPU levels and with the maximum turbidity of the clot lysis profile. In conclusion, our method offers a technique to determine the endogenous CPU generation potential of an individual. The parameters obtained by the method quantitatively describe the different mechanisms that influence CPU generation during the complex interplay between coagulation and fibrinolysis, which are in line with the threshold hypothesis.

  6. In vitro cell culture, platelet adhesion tests and in vivo implant tests of plasma-polymerized para-xylene films

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Chia-Man [Department of Surgery, Taichung Veterans General Hospital, Taiwan, ROC (China); National Yang-Ming University, Taipei, Taiwan, ROC (China); Yeh, Chou-Ming, E-mail: cmchou4301@gmail.com [Taichung Hospital, Department of Health, Executive Yuan, Taiwan, ROC (China); Chung, Chi-Jen [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); He, Ju-Liang [Department of Materials Science and Engineering, Feng Chia University, Taiwan, ROC (China)

    2013-09-01

    Plasma-polymerized para-xylene (PPX) was developed in a previous study by adjusting the process parameters: pulse frequency of the power supply (ω{sub p}) and para-xylene monomer flow rate (f{sub p}). All the obtained PPX films exhibit an amorphous structure and present hydrophobicity (water contact angle ranging from 98.5° to 121.1°), higher film growth rate and good fibroblast cell proliferation. In this study, in vitro tests (fibroblast cell compatibility and platelet adhesion) and an in vivo animal study were performed by using PPX deposited industrial-grade silicone sheets (IGS) and compared with medical-grade silicone ones (MS), which were commonly manufactured into catheters or drainage tubes in clinical use. The results reveal that PPX deposited at high ω{sub p} or high f{sub p}, in comparison with MS, exhibit better cell proliferation and clearly shows less cell adhesion regardless of ω{sub p} and f{sub p}. PPX also exhibit a comparatively lower level of platelet adhesion than MS. In the animal study, PPX-coated IGS result in similar local tissue responses at 3, 7 and 28 days (short-term) and 84 days (long-term) after subcutaneous implantation the abdominal wall of rodents compared with respective responses to MS. These results suggest that PPX-coated industrial-grade silicone is one alternative to high cost medical-grade silicone.

  7. Porous tantalum coatings prepared by vacuum plasma spraying enhance bmscs osteogenic differentiation and bone regeneration in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Ze Tang

    Full Text Available Tantalum, as a potential metallic implant biomaterial, is attracting more and more attention because of its excellent anticorrosion and biocompatibility. However, its significantly high elastic modulus and large mechanical incompatibility with bone tissue make it unsuitable for load-bearing implants. In this study, porous tantalum coatings were first successfully fabricated on titanium substrates by vacuum plasma spraying (VPS, which would exert the excellent biocompatibility of tantalum and alleviate the elastic modulus of tantalum for bone tissue. We evaluated cytocompatibility and osteogenesis activity of the porous tantalum coatings using human bone marrow stromal cells (hBMSCs and its ability to repair rabbit femur bone defects. The morphology and actin cytoskeletons of hBMSCs were observed via electron microscopy and confocal, and the cell viability, proliferation and osteogenic differentiation potential of hBMSCs were examined quantitatively by PrestoBlue assay, Ki67 immunofluorescence assay, real-time PCR technology and ALP staining. For in vivo detection, the repaired femur were evaluated by histomorphology and double fluorescence labeling 3 months postoperation. Porous tantalum coating surfaces promoted hBMSCs adhesion, proliferation, osteogenesis activity and had better osseointegration and faster new bone formation rate than titanium coating control. Our observation suggested that the porous tantalum coatings had good biocompatibility and could enhance osseoinductivity in vitro and promote new bone formation in vivo. The porous tantalum coatings prepared by VPS is a promising strategy for bone regeneration.

  8. Protective effect of atmospheric pressure plasma on oxidative stress-induced neuronal injuries: an in vitro study

    Science.gov (United States)

    Yan, Xu; Qiao, Yajun; Ouyang, Jiting; Jia, Mei; Li, Jiaxin; Yuan, Fang

    2017-03-01

    Atmospheric pressure plasma jet (APPJ) can produce biological active species for biomedical applications. This work proves direct evidence of the protective effects of APPJ against oxidative stress. SH-SY5Y cells, a commonly used cell model for the study of neurotoxicity and neuroprotection, were treated with APPJ for different durations. Then, cells were exposed to 200 µM H2O2 for 24 h and cell viability was measured using a CCK-8 kit. Changes in cell apoptosis were further confirmed by calcein-AM fluorescence imaging and flow cytometry. Extracellular NO production was detected using the Griess method. The results showed that APPJ protected SH-SY5Y from H2O2-induced apoptosis in a time-dependent manner. Moreover, extracellular NO production was significantly increased with the APPJ treatment. The results show in vitro that APPJ treatment could protect SH-SY5Y cells from oxidative stress by reducing cell apoptosis, which might be related to the reactive nitrogen species induced by the APPJ treatment. Our results indicate that the APPJ may have therapeutic potential as a novel ‘NO donor drug’ in neuroprotection and in the treatment of neurodegenerative diseases.

  9. Inactivation of B. subtilis spores by low pressure plasma—influence of optical filters and photon/particle fluxes on the inactivation efficiency

    Science.gov (United States)

    Fiebrandt, Marcel; Hillebrand, Bastian; Lackmann, Jan-Wilm; Raguse, Marina; Moeller, Ralf; Awakowicz, Peter; Stapelmann, Katharina

    2018-01-01

    Inactivation experiments were performed with Bacillus subtilis spores in a low pressure double inductively coupled plasma (DICP) system. Argon, nitrogen and oxygen at 5 Pa were used as feed gas to change the emission spectrum in the range of 100 nm to 400 nm, as well as between radical and metastable densities. Optical filters were applied, to block particles and selected wavelengths from the spores. By determining absolute photon fluxes, the sporicidal efficiency of various wavelength ranges was evaluated. The results showed good agreement with other plasma experiments, as well as with monochromatic light inactivation experiments from a synchrotron. The findings indicated that the inactivation rate constants of broadband plasma emission and monochromatic light were identical, and that no synergistic effect exists. Furthermore, the influence of radicals, ions and metastables on the inactivation efficiency was of minor importance in the set-up used, and radiation was the main reason for spore inactivation.

  10. Improved in vitro evaluation of novel antimicrobials: potential synergy between human plasma and antibacterial peptidomimetics, AMPs and antibiotics against human pathogenic bacteria.

    Science.gov (United States)

    Citterio, Linda; Franzyk, Henrik; Palarasah, Yaseelan; Andersen, Thomas Emil; Mateiu, Ramona Valentina; Gram, Lone

    2016-01-01

    Stable peptidomimetics mimicking natural antimicrobial peptides (AMPs) have emerged as a promising class of potential novel antibiotics. In the present study, we aimed at determining whether the antibacterial activity of two α-peptide/β-peptoid peptidomimetics against a range of bacterial pathogens was affected by conditions mimicking in vivo settings. Their activity was enhanced to an unexpected degree in the presence of human blood plasma for thirteen pathogenic Gram-positive and Gram-negative bacteria. MIC values typically decreased 2- to 16-fold in the presence of a human plasma concentration that alone did not damage the cell membrane. Hence, MIC and MBC data collected in these settings appear to represent a more appropriate basis for in vivo experiments preceding clinical trials. In fact, concentrations of peptidomimetics and peptide antibiotics (e.g. polymyxin B) required for in vivo treatments might be lower than traditionally deduced from MICs determined in laboratory media. Thus, antibiotics previously considered too toxic could be developed into usable last-resort drugs, due to ensuing lowered risk of side effects. In contrast, the activity of the compounds was significantly decreased in heat-inactivated plasma. We hypothesize that synergistic interactions with complement proteins and/or clotting factors most likely are involved. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  11. {sup 99m}Tc-NC100668, a new tracer for imaging venous thromboemboli: pre-clinical biodistribution and incorporation into plasma clots in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, David [Grove Centre, Research and Development, GE Healthcare Bio-Sciences, Little Chalfont (United Kingdom); Uppsala University Hospital, Institution of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala (Sweden); Lewis, Joanne; Battle, Mark; Lear, Rochelle; Farrar, Gill; Barnett, D.J.; Godden, Vanessa; Oliveira, Alexandra; Coombes, Catherine [Grove Centre, Research and Development, GE Healthcare Bio-Sciences, Little Chalfont (United Kingdom); Ahlstroem, Haakan [Uppsala University Hospital, Institution of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala (Sweden)

    2006-11-15

    {sup 99m}Tc-NC100668 is a new radiotracer being developed to aid the diagnosis of thromboembolism. The structure of NC100668 is similar to a region of human {alpha}{sub 2}-antiplasmin, which is a substrate for factor XIIIa (FXIIIa). The purpose of this study was to confirm the uptake of {sup 99m}Tc-NC100668 into forming plasma clot and to establish the biodistribution of {sup 99m}Tc-NC100668 in Wistar rats. The in vitro plasma clot uptake of {sup 99m}Tc-NC100668 and other compounds with known affinities to FXIIIa was measured using a plasma clot assay. The biodistribution and blood clot uptake of radioactivity of {sup 99m}Tc-NC100668 in normal Wistar rats and those bearing experimentally induced deep vein thrombi were investigated. The in vitro uptake of {sup 99m}Tc-NC100668 was greater than that for [{sup 14}C]dansyl cadaverine, a known substrate of FXIIIa in the plasma clot assay. The biodistribution of {sup 99m}Tc-NC100668 in male and female Wistar rats up to 24 h p.i. showed that radioactivity was rapidly excreted, predominantly into the urine, with very little background tissue retention. In vivo the uptake and retention of {sup 99m}Tc-NC100668 into the blood clot was greater than could be accounted for by non-specific accumulation of the radiotracer within the blood clot. {sup 99m}Tc-NC100668 was retained by plasma clots in vitro and blood clots in vivo. No significant tissue retention which could interfere with the ability to image thrombi in vivo was observed. This evidence suggests that {sup 99m}Tc-NC100668 might be useful in the detection of thromboembolism. (orig.)

  12. Human umbilical cord blood plasma can replace fetal bovine serum for in vitro expansion of functional human endothelial colony-forming cells.

    Science.gov (United States)

    Huang, Lan; Critser, Paul J; Grimes, Brenda R; Yoder, Mervin C

    2011-07-01

    A hierarchy of endothelial colony-forming cells (ECFC) with different levels of proliferative potential has been identified in human circulating blood and blood vessels. ECFC has recently become an attractive target for new vascular regenerative therapies; however, in vitro expansion of ECFC typically depends on the presence of fetal bovine serum (FBS) or fetal calf serum (FCS) in the culture medium, which is not appropriate for its therapeutic application. To identify optimal conditions for in vitro expansion of ECFC, the effects of human endothelial serum-free medium (SFM) supplemented with six pro-angiogenic cytokines and human umbilical cord blood plasma (HCP) were investigated. The in vitro morphology, proliferation, surface antigen expression and in vivo vessel-forming ability were utilized for examining the effects of medium on ECFC. This novel formulation of endothelial cell culture medium allows us, for the first time, to isolate and expand human ECFC efficiently in vitro with a low concentration of HCP (1.5%) and without bovine serum additives. In this serum-reduced medium (SRM), human ECFC colony yields remained quantitatively similar to those cultured in a high concentration (10%) of bovine serum-supplemented medium. SRM-cultured ECFC displayed a robust clonal proliferative ability in vitro and human vessel-forming capacity in vivo. The present study provides a novel method for the expansion of human ECFC in vitro and will help to advance approaches for using the cells in human therapeutic trials.

  13. In vitro degradation and biocompatibility of Fe–Pd and Fe–Pt composites fabricated by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Huang, T. [State Key Laboratory for Turbulence and Complex System, College of Engineering, Peking University, Beijing 100871 (China); Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Cheng, J. [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zheng, Y.F., E-mail: yfzheng@pku.edu.cn [State Key Laboratory for Turbulence and Complex System, College of Engineering, Peking University, Beijing 100871 (China); Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China)

    2014-02-01

    The Fe–Pd and Fe–Pt composites prepared by spark plasma sintering have small grain size. • The addition of Pd or Pt greatly accelerated the degradation rate of pure iron. • Fe–Pd and Fe–Pt composites uniformly corroded in Hank's solution. • Fe–Pd and Fe–Pt composites both exhibited excellent in vitro biocompatibility.

  14. Photodynamic Inactivation of Food Pathogen Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Irina Buchovec

    2010-01-01

    Full Text Available The aim of this study is to examine the possibility to inactivate food pathogen Listeria monocytogenes by nonthermal antimicrobial treatment – photosensitization. L. monocytogenes was incubated with 5-aminolevulinic acid (ALA (7.5 mM for 0–2 h to produce endogenous photosensitizers and then illuminated with visible light. The LED-based light source used for the illumination of L. monocytogenes emitted light at λ=400 nm with energy density of 20 mW/cm2. The illumination time varied from 0 to 20 min, and a total energy dose reached 0–24 J/cm2. The obtained results reveal that L. monocytogenes can effectively produce endogenous porphyrins after incubation with 7.5 mM ALA. Subsequent illumination of cells with visible light significantly decreased their viability in vitro (4 log. After adhesion of Listeria to the surface of packaging material and following photosensitization, the surface-attached bacterial population was inactivated by 3.7 log. In addition, most resistant Listeria biofilms are susceptible to this treatment. Their inactivation reached 3.1 log under certain experimental conditions. The cells and biofilms of Gram-positive bacteria L. monocytogenes ATCL3C 7644 could be effectively inactivated by ALA-based photosensitization in the solution as well as adhered onto the surface of packaging material in a nonthermal way.

  15. De novo transcriptome assembly of Perkinsus olseni trophozoite stimulated in vitro with Manila clam (Ruditapes philippinarum) plasma.

    Science.gov (United States)

    Hasanuzzaman, Abul Farah Md; Robledo, Diego; Gómez-Tato, Antonio; Alvarez-Dios, Jose A; Harrison, Peter W; Cao, Asunción; Fernández-Boo, Sergio; Villalba, Antonio; Pardo, Belén G; Martínez, Paulino

    2016-03-01

    The protistan parasite Perkinsus olseni is a deadly causative agent of perkinsosis, a molluscan disease affecting Manila clam (Ruditapes philippinarum), having a significant impact on world mollusc production. Deciphering the underlying molecular mechanisms in R. philippinarum-P. olseni interaction is crucial for controlling this parasitosis. The present study investigated the transcriptional expression in the parasite trophozoite using RNA-seq. Control and treatment (in vitro challenged with Manila clam-plasma) P. olseni trophozoite RNA were extracted and sequenced on the Illumina HiSeq 2000 instrument using a 100-bp paired-end sequencing strategy. Paired reads (64.7 million) were de novo assembled using Trinity, and the resultant transcripts were further clustered using CAP3. The re-constructed P. olseni transcriptome contains 47,590 unique transcripts of which 23,505 were annotated to 9764 unique proteins. A large number of genes were associated with Gene Ontology terms such as stress and immune-response, cell homeostasis, antioxidation, cell communication, signal transduction, signalling and proteolysis. Among annotated transcripts, a preliminary gene expression analysis detected 679 up-regulated and 478 down-regulated genes, linked to virulence factors, anti-oxidants, adhesion and immune-response molecules. Genes of several metabolic pathways such as DOXP/MEP, FAS II or folate biosynthesis, which are potential therapeutic targets, were identified. This study is the first description of the P. olseni transcriptome, and provides a substantial genomic resource for studying the molecular mechanisms of the host-parasite interaction in perkinsosis. In this sense, it is also the first evaluation of the parasite gene expression after challenge with clam extracellular products. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Platelet-rich plasma enhances the integration of bioengineered cartilage with native tissue in an in vitro model.

    Science.gov (United States)

    Sermer, Corey; Kandel, Rita; Anderson, Jesse; Hurtig, Mark; Theodoropoulos, John

    2018-02-01

    Current therapies for cartilage repair can be limited by an inability of the repair tissue to integrate with host tissue. Thus, there is interest in developing approaches to enhance integration. We have previously shown that platelet-rich plasma (PRP) improves cartilage tissue formation. This raised the question as to whether PRP could promote cartilage integration. Chondrocytes were isolated from cartilage harvested from bovine joints, seeded on a porous bone substitute and grown in vitro to form an osteochondral-like implant. After 7 days, the biphasic construct was soaked in PRP for 30 min before implantation into the core of a donut-shaped biphasic explant of native cartilage and bone. Controls were not soaked in PRP. The implant-explant construct was cultured for 2-4 weeks. PRP-soaked bioengineered implants integrated with host tissue in 73% of samples, whereas controls only integrated in 19% of samples. The integration strength, as determined by a push-out test, was significantly increased in the PRP-soaked implant group (219 ± 35.4 kPa) compared with controls (72.0 ± 28.5 kPa). This correlated with an increase in glycosaminoglycan and collagen accumulation in the region of integration in the PRP-treated implant group, compared with untreated controls. Immunohistochemical studies revealed that the integration zone contained collagen type II and aggrecan. The cells at the zone of integration in the PRP-soaked group had a 3.5-fold increase in matrix metalloproteinase-13 gene expression compared with controls. These results suggest that PRP-soaked bioengineered cartilage implants may be a better approach for cartilage repair due to enhanced integration. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Inactivation of rabies virus.

    Science.gov (United States)

    Wu, Guanghui; Selden, David; Fooks, Anthony R; Banyard, Ashley

    2017-05-01

    Rabies virus is a notifiable pathogen that must be handled in high containment facilities where national and international guidelines apply. For the effective inactivation of rabies virus, a number of reagents were tested. Virkon S (1%) solution caused more than 4log reduction of rabies virus in culture medium supplemented with 10% foetal calf serum within 1min. Isopropyl alcohol (70%) treatment resulted in >3log reduction of rabies virus within 20s when applied at a ratio of 19:1, making it a suitable agent for surface decontamination whereas 70% ethanol was ineffective. Rabies virus (from 102.33 to 103ffu/ml) was also inactivated when cell cultures were fixed with 3% or 4% paraformaldehyde for 30min. Regardless of inactivation procedure, when taking inactivated virus preparations out of a biological containment envelope, proof of inocuity must be demonstrated to cover any possible error/deviation from procedure. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  18. Pathogen Inactivation Technologies for Cellular Blood Components: an Update

    Science.gov (United States)

    Schlenke, Peter

    2014-01-01

    Summary Nowadays patients receiving blood components are exposed to much less transfusion-transmitted infectious diseases than three decades before when among others HIV was identified as causative agent for the acquired immunodeficiency syndrome and the transmission by blood or coagulation factors became evident. Since that time the implementation of measures for risk prevention and safety precaution was socially and politically accepted. Currently emerging pathogens like arboviruses and the well-known bacterial contamination of platelet concentrates still remain major concerns of blood safety with important clinical consequences, but very rarely with fatal outcome for the blood recipient. In contrast to the well-established pathogen inactivation strategies for fresh frozen plasma using the solvent-detergent procedure or methylene blue and visible light, the bench-to-bedside translation of novel pathogen inactivation technologies for cell-containing blood components such as platelets and red blood cells are still underway. This review summarizes the pharmacological/toxicological assessment and the inactivation efficacy against viruses, bacteria, and protozoa of each of the currently available pathogen inactivation technologies and highlights the impact of the results obtained from several randomized clinical trials and hemovigilance data. Until now in some European countries pathogen inactivation technologies are in in routine use for single-donor plasma and platelets. The invention and adaption of pathogen inactivation technologies for red blood cell units and whole blood donations suggest the universal applicability of these technologies and foster a paradigm shift in the manufacturing of safe blood. PMID:25254027

  19. Inactivation of Zika virus in platelet components using amotosalen and ultraviolet A illumination.

    Science.gov (United States)

    Santa Maria, Felicia; Laughhunn, Andrew; Lanteri, Marion C; Aubry, Maite; Musso, Didier; Stassinopoulos, Adonis

    2017-08-01

    Concerned over the risk of Zika virus (ZIKV) transfusion transmission, public health agencies recommended the implementation of mitigation strategies for its prevention. Those strategies included the use of pathogen inactivation for the treatment of plasma and platelets. The efficacy of amotosalen/ultraviolet A to inactivate ZIKV in plasma had been previously demonstrated, and the efficacy of inactivation in platelets with the same technology was assumed. These studies quantify ZIKV inactivation in platelet components using amotosalen/ultraviolet A. Platelet components were spiked with ZIKV, and ZIKV infectious titers and RNA loads were measured by cell culture-based assays and real-time polymerase chain reaction in spiked platelet components before and after photochemical treatment using amotosalen/ultraviolet A. The mean ZIKV infectivity titers and RNA loads in platelet components before inactivation were either 4.9 log10 plaque forming units per milliliter, or 4.4 log10 50% tissue culture infective dose per milliliter and 7.5 log10 genome equivalents per milliliter, respectively. No infectivity was detected immediately after amotosalen/ultraviolet A treatment. No replicative virus remained after treatment, as demonstrated by multiple passages on Vero cell cultures; and ZIKV RNA was not detected from the first passage after inactivation. Additional experiments in this study demonstrated efficient inactivation to the limit of detection in platelets manufactured in 65% platelet additive solution, 35% plasma, or 100% plasma. As previously demonstrated for plasma, robust levels of ZIKV inactivation were achieved in platelet components. With inactivation of higher levels of ZIKV than those reported in asymptomatic, RNA-reactive blood donors, the pathogen-inactivation system using amotosalen/ultraviolet A offers the potential to mitigate the risk of ZIKV transmission by plasma and platelet transfusion. © 2017 The Authors Transfusion published by Wiley Periodicals, Inc

  20. The non-enzymatic inactivation of thirteen β-lactam antibiotics in human faeces

    NARCIS (Netherlands)

    Jansen, G; Weissing, F; de Vries Hospers, H; Tonk, R; van der Waaij, D

    1992-01-01

    In order to obtain a method that could predict the in vitro inactivation of an antibiotic in the digestive tract, the non-enzymatic inactivation of 13 beta-lactam antibiotics by human faeces was investigated. Benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin,

  1. The non-enzymatic inactivation of thirteen beta-lactam antibiotics in human faeces

    NARCIS (Netherlands)

    Jansen, G; Weissing, F; de Vries-Hospers, H; Tonk, R; van der Waaij, D

    1992-01-01

    In order to obtain a method that could predict the in vitro inactivation of an antibiotic in the digestive tract, the non-enzymatic inactivation of 13 beta-lactam antibiotics by human faeces was investigated. Benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin,

  2. Inactivation of 12 viruses by heating steps applied during manufacture of a hepatitis B vaccine

    NARCIS (Netherlands)

    Lelie, P. N.; Reesink, H. W.; Lucas, C. J.

    1987-01-01

    The efficacy of two heating cycles (90 sec at 103 degrees C and 10 hr at 65 degrees C) used during manufacture of a plasma-derived hepatitis-B vaccine was validated for the inactivation of 12 virus families. A period of 15 min warming up to 65 degrees C had already completely inactivated

  3. Evaluation of hepatic clearance prediction using in vitro data: emphasis on fraction unbound in plasma and drug ionisation using a database of 107 drugs.

    Science.gov (United States)

    Hallifax, David; Houston, J Brian

    2012-08-01

    Underprediction of in vivo intrinsic clearance (CL(int)) of unbound drug from human hepatic in vitro systems using physiological extrapolation methodology is accepted as a common outcome. Poulin et al. (2012. J Pharm Sci 101:838-851) recently proposed an approach involving determination of effective fraction unbound in plasma (fu(p)) based on albumin-facilitated hepatic uptake of acidic/neutral drugs which improved prediction accuracy and precision for 25 drugs highly bound to plasma proteins. This approach includes correction of unbound drug according to the ionisation fraction either side of the plasma membrane based on pH difference. Here, we assessed the proposed method using a larger database of predictions of CL(int) for 107 drugs involving hepatocytes (89 drugs) and microsomes (64 drugs). The proposed method was similarly effective in minimising average prediction bias (to within twofold), unlike the conventional fu(p) correction method. However, precision was similar between methods and there was no evidence in the larger database that prediction bias was associated with fu(p). Prediction bias for hepatocytes was clearance dependent by either method, indicating important sources of bias from in vitro methodology. Therefore, to progress beyond empirical correction of bias, there is further need of mechanistic elucidation to improve prediction methodology. Copyright © 2012 Wiley Periodicals, Inc.

  4. 'In vitro' studies on the interaction of rickettsia and macrophages. I. Effect of ultraviolet light on 'Coxiella burnetii' inactivation and macrophage enzymes: uv-inactivated 'C. burnetii'/macrophage enzymes. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Little, J.S.; Kishimoto, R.A.; Canonico, P.G.

    1979-09-04

    The inactivation of Coxiella burnetii in suspension or in cultures of guinea pig peritoneal macrophages by ultraviolet (UV) light was studied. The effect of UV treatment on the activity of macrophage organelle marker enzymes and their subsequent equilibration in linear sucrose gradients was also determined. It was shown that UV treatment of 600 microwatts/sq cm for 15 sec at a distance of 10 cm inactivated C. burnetii, either in suspension (10 to the 8th power organisms/ML) or within guinea pig peritoneal macrophages. Similar UV treatment had little effect on the activity or equilibration of macrophage organelle marker enzymes in linear sucrose gradients. However, longer exposure caused considerable inactivatioin of these enzymes.

  5. Photodynamic inactivation of fibroblasts by a cationic porphyrin

    NARCIS (Netherlands)

    Lambrechts, Saskia A. G.; Schwartz, Kevin R.; Aalders, Maurice C. G.; Dankert, Jacob B.

    2005-01-01

    An important determinant of the clinical applicability and value of antimicrobial photodynamic inactivation (PDI) is the cytotoxicity of the treatment to human cells. We evaluated the in vitro cytotoxicity of PDI to human dermal fibroblasts using 5-phenyl-10,15,20-tris(N-methyl-4-pyridyl)porphyrin

  6. Two SNF1-Related Protein Kinases from Spinach Leaf Phosphorylate and Inactivate 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase, Nitrate Reductase, and Sucrose Phosphate Synthase in Vitro1

    Science.gov (United States)

    Sugden, Christopher; Donaghy, Paul G.; Halford, Nigel G.; Hardie, D. Grahame

    1999-01-01

    We resolved from spinach (Spinacia oleracea) leaf extracts four Ca2+-independent protein kinase activities that phosphorylate the AMARAASAAALARRR (AMARA) and HMRSAMSGLHLVKRR (SAMS) peptides, originally designed as specific substrates for mammalian AMP-activated protein kinase and its yeast homolog, SNF1. The two major activities, HRK-A and HRK-C (3-hydroxy-3-methylglutaryl-coenzyme A reductase kinase A and C) were extensively purified and shown to be members of the plant SnRK1 (SNF1-related protein kinase 1) family using the following criteria: (a) They contain 58-kD polypeptides that cross-react with an antibody against a peptide sequence characteristic of the SnRK1 family; (b) they have similar native molecular masses and specificity for peptide substrates to mammalian AMP-activated protein kinase and the cauliflower homolog; (c) they are inactivated by homogeneous protein phosphatases and can be reactivated using the mammalian upstream kinase; and (d) they phosphorylate 3-hydroxy-3-methylglutaryl-coenzyme A reductase from Arabidopsis at the inactivating site, serine (Ser)-577. We propose that HRK-A and HRK-C represent either distinct SnRK1 isoforms or the same catalytic subunit complexed with different regulatory subunits. Both kinases also rapidly phosphorylate nitrate reductase purified from spinach, which is associated with inactivation of the enzyme that is observed only in the presence of 14-3-3 protein, a characteristic of phosphorylation at Ser-543. Both kinases also inactivate spinach sucrose phosphate synthase via phosphorylation at Ser-158. The SNF1-related kinases therefore potentially regulate several major biosynthetic pathways in plants: isoprenoid synthesis, sucrose synthesis, and nitrogen assimilation for the synthesis of amino acids and nucleotides. PMID:10318703

  7. The effect of lidocaine on in vitro neutrophil and endothelial adhesion molecule expression induced by plasma obtained during tourniquet-induced ischaemia and reperfusion.

    LENUS (Irish Health Repository)

    Lan, W

    2012-02-03

    BACKGROUND: Changes in neutrophil and endothelial adhesion molecule expression occur during perioperative ischaemia and reperfusion (I\\/R) injury. We investigated the effects of lidocaine on neutrophil-independent changes in neutrophil and endothelial adhesion molecule expression associated with tourniquet-induced I\\/R. METHODS: Plasma was obtained from venous blood samples (tourniquet arm) taken before (baseline), during, 15 min, 2 and 24 h following tourniquet release in seven patients undergoing elective upper limb surgery with tourniquet application. Isolated neutrophils from healthy volunteers (n = 7) were pretreated in the presence or absence of lidocaine (0.005, 0.05 and 0.5 mg mL(-1) for 1 h, and then incubated with I\\/R plasma for 2 h. Human umbilical vein endothelial cells (HUVECs) were pretreated in the presence or absence of lidocaine (0.005, 0.05 and 0.5 mg mL(-1)) for 1 h, and then incubated with the plasma for 4 h. Adhesion molecule expression was estimated using flow cytometry. Data were analysed using ANOVA and post hoc Student-Newman-Keuls tests. RESULTS: I\\/R plasma (withdrawn 15 min following tourniquet release) increased isolated neutrophil CD11b (P = 0.03), CD18 (P = 0.01) and endothelial intercellular adhesion molecule-1 (ICAM-1) (P = 0.008) expression compared to baseline. CD11b, CD18 and ICAM-1 expression on lidocaine (0.005 mg mL(-1)) treated neutrophils was similar to control. CD11b (P < 0.001), CD18 (P = 0.03) and ICAM-1 (P = 0.002) expression on lidocaine (0.05 mg mL(-1)) treated neutrophils and HUVECs was less than that on controls. CONCLUSION: Increased in vitro neutrophil and endothelial cell adhesion molecule expression on exposure to plasma obtained during the early reperfusion phase is diminished by lidocaine at greater than clinically relevant plasma concentrations.

  8. Antioxidant Chemo-Protective Role Of Buffalo Colostrum And Milk Whey Derived Peptide Against 2 4-Dinitrophenol Induced-Oxidative Damage On Human Plasma In Vitro.

    Directory of Open Access Journals (Sweden)

    Alemayehu Letebo Albejo

    2017-09-01

    Full Text Available This study investigates the role of buffalo colostrum and milk whey derived peptides in protection against oxidative damage induced by 2 4-Dinitrophenol 2 4-DNP in human blood serum samples in vitro. A biomarker enzymes for oxidative stress like Alkaline phosphatase ALP and acid phosphatase ACP oxidative damage markers indicating extent of host antioxidant reserve indicators like reduced glutathione GSH were measured by spectrophotometric techniques in four different groups namely 1 Human blood plasma only control 2 Human blood plasma 24-DNP 3 Human blood plasma colostrum whey derived peptides 24-DNP 4 Human blood plasma colostrum whey derived peptides 5 Human blood plasma milk whey derived peptides 24-DNP and 6 Human blood plasma milk whey derived peptides. Following exposure to 2 4-DNP levels of antioxidants like GSH was significantly decreased in comparison to control e.g. GSH 0.568 0.015 vs0.871 0.022mol0.1 mg proteins. In addition the concentration of biomarker enzymes for 24-DNP induced membrane damage and oxidative stress like ALP and ACP were increased in serum by oxidant compared to control e.g. ALP 5.497 0.185 vs. 2.782 0.000molmg protein ACP 1.689 0.047 vs. 0.629 0.047molmg protein. Pretreatment with buffalo whey derived peptides significantly protects 24-DNP induced RBC membrane lyses and release of ALP and ACP into serum environment. e.g. ALP 3.444 0.094 vs. 5.497 0.185 molmg protein ACP 0.629 0.047 vs. 1.689 0.047molmg protein. Pretreatment with whey derived peptides give protection to oxidative damage and shifts the trend towards amelioration and replenishment of the antioxidant status.

  9. An In Vitro Analysis of the Effects of Intravenous Lipid Emulsion on Free and Total Local Anaesthetic Concentrations in Human Blood and Plasma

    Directory of Open Access Journals (Sweden)

    Louise Ann Clark

    2014-01-01

    Full Text Available Background. Intravenous lipid emulsion (ILE is recommended as a “rescue” treatment for local anaesthetic (LA toxicity. A purported mechanism of action suggests that lipophilic LAs are sequestered into an intravascular “lipid-sink,” thus reducing free drug concentration. There is limited data available correlating the effects of ILE on LAs. Aims. To compare the in vitro effect of ILE on LA concentrations in human blood/plasma and to correlate this reduction to LA lipophilicity. Method. One of four LAs (bupivacaine-most lipophilic-4 mg/L, ropivacaine-6 mg/L, lignocaine-14 mg/L, and prilocaine-least lipophilic-7 mg/L was spiked into plasma or whole blood. ILE or control-buffer was added. Plasma was centrifuged to separate ILE and total-LA concentration assayed from the lipid-free fraction. Whole blood underwent equilibrium dialysis and free-LA concentration was measured. Percent reduction in LA concentration from control was compared between the LAs and correlated with lipophilicity. Results. ILE caused a significant reduction in total and free bupivacaine concentration compared with the other LAs. Ropivacaine had the least reduction in concentration, despite a lipophilicity similar to bupivacaine. The reduction in LA concentration correlated to increasing lipophilicity when ropivacaine was excluded from analysis. Conclusion. In this first in vitro model assessing both free- and total-LA concentrations exposed to ILE in human blood/plasma, ILE effect was linearly correlated with increasing lipophilicity for all but ropivacaine.

  10. Pathogen Inactivation Technologies: The Advent of Pathogen-Reduced Blood Components to Reduce Blood Safety Risk.

    Science.gov (United States)

    Devine, Dana V; Schubert, Peter

    2016-06-01

    Pathogen inactivation technologies represent a shift in blood safety from a reactive approach to a proactive protective strategy. Commercially available technologies demonstrate effective killing of most viruses, bacteria, and parasites and are capable of inactivating passenger leukocytes in blood products. The use of pathogen inactivation causes a decrease in the parameters of products that can be readily measured in laboratory assays but that do not seem to cause any alteration in hemostatic effect of plasma or platelet transfusions. Effort needs to be made to further develop these technologies so that the negative quality impact is ameliorated without reducing the pathogen inactivation effectiveness. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Removal of naturally grown human biofilm with an atmospheric pressure plasma jet: An in-vitro study.

    Science.gov (United States)

    Jablonowski, Lukasz; Fricke, Katja; Matthes, Rutger; Holtfreter, Birte; Schlüter, Rabea; von Woedtke, Thomas; Weltmann, Klaus-Dieter; Kocher, Thomas

    2017-05-01

    The removal of biofilm is a prerequisite for a successful treatment of biofilm-associated diseases. In this study, we compared the feasibility of an atmospheric pressure plasma device with a sonic powered brush to remove naturally grown supragingival biofilm from extracted teeth. Twenty-four periodontally hopeless teeth were extracted. Argon jet plasma with an oxygen admixture of 1 vol% and a sonically driven brush were used to remove biofilm with application times of 60 s, 180 s and 300 s. The treatment efficiency was assessed with light microscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The highest biofilm removal rate was observed after an application time of 180 s/300 s with the sonic brush (80.4%/86.2%), plasma (75.5%/89.0%). These observations were confirmed by SEM. According to XPS analysis, plasma treatment decreased the amount of carbon and nitrogen, indicative of an extensive removal of proteins. Plasma treatment of naturally grown biofilm resulted in an effective cleaning of the tooth surface and was comparable to mechanical treatment. Treatment time had a significant influence on plaque reduction. These results showed that plasma could be a useful adjuvant treatment modality in cases where biofilm removal or reduction plays a decisive role, such as periodontitis and peri-implantitis. Plasma-treated biofilm on an extracted tooth. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Antithrombin inactivation by neutrophil elastase requires heparin.

    Science.gov (United States)

    Jordan, R E; Nelson, R M; Kilpatrick, J; Newgren, J O; Esmon, P C; Fournel, M A

    1989-09-11

    In certain thrombotic states, large declines in the levels of functional circulating antithrombin occur, which may reflect the highly active nature of the endothelial surface in suppressing excessive amounts of activated coagulation enzymes. Alternatively, we have recently observed an unexpected and paradoxical in vitro functioning of heparin that could result in the inactivation of antithrombin in pathologic conditions. Specifically, antithrombin was rendered nonfunctional as an inhibitor of clotting enzymes as a result of a limited, heparin-dependent cleavage by neutrophil elastase. This inactivation occurred only in the presence of the active anticoagulant heparin fraction, which suggested that the heparin-antithrombin complex was the substrate for elastase attack. Interestingly, neutrophil elastase was found to bind tightly to heparin and heparin-like materials. Neutrophil elastase has been previously linked to nonspecific proteinolysis occurring in inflammatory thrombotic reactions. This affinity of both antithrombin and elastase for heparin suggests a novel mechanism of potential specificity. An important component of this hypothesis is the localization of the elastase/antithrombin reaction away from the high circulating levels of elastase inhibitors. The proposed inactivation of antithrombin on the vascular surface would likely occur only in pathologic states associated with neutrophil sequestration and activation. Nevertheless, this mechanism could lead to a localized reversal of the nonthrombogenic nature of the endothelium and potentially lead to significant reductions of functional antithrombin in certain disease states.

  13. Thermal Inactivation of Viruses

    Science.gov (United States)

    1977-10-01

    S) VIKU3FS THERMAL RESISTANCE FOODS FLUIDS FOOD PROCESSING FOOD PRESERVATION CONTAMINATION HEAT VIRAL NUCLEIC ACIDS ao’.AjUsTNACT (Conilnum...an rm**— •**» It nmc +nmy m>d Id+atttr by M«o* fmbm) A review of the literature pertaining to thermal inactivation of virus in fluid media» fluid...vacuum packaged in cans or in flexible pouches , frozen to ca. -40 C, and irradiated within a temperature range of -40 C to -8 C to obtain the

  14. Kinetic analysis of Legionella inactivation using ozone in wastewater.

    Science.gov (United States)

    Li, Jun; Li, Kunquan; Zhou, Yan; Li, Xuebin; Tao, Tao

    2017-02-01

    Legionella inactivation using ozone was studied in wastewater using kinetic analysis and modeling. The experimental results indicate that the relationship between the ozone concentration, germ concentration, and chemical oxygen demand (COD) can be used to predict variations in germ and COD concentrations. The ozone reaction with COD and inactivation of Legionella occurred simultaneously, but the reaction with COD likely occurred at a higher rate than the inactivation, as COD is more easily oxidized by ozone than Legionella. Higher initial COD concentrations resulted in a lower inactivation rate and higher lnN/N0. Higher temperature led to a higher inactivation efficiency. The relationship of the initial O3 concentration and Legionella inactivation rate was not linear, and thus, the Ct value required for a 99.99% reduction was not constant. The initial O3 concentration was more important than the contact time, and a reduction of the initial O3 concentration could not be compensated by increasing the contact time. The Ct values were compared over a narrow range of initial concentrations; the Ct values could only be contrasted when the initial O3 concentrations were very similar. A higher initial O3 concentration led to a higher inflection point value for the lnN/N0 vs C0t curve. Energy consumption using a plasma corona was lower than when using boron-doped diamond electrodes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Evaluation of Cold Plasma Treatment and Safety in Disinfecting 3-week Root Canal Enterococcus faecalis Biofilm In Vitro.

    Science.gov (United States)

    Li, Yinglong; Sun, Ke; Ye, Guopin; Liang, Yongdong; Pan, Hong; Wang, Guomin; Zhao, Yijiao; Pan, Jie; Zhang, Jue; Fang, Jing

    2015-08-01

    Although endodontic infection is caused by multi-bacteria species, Enterococcus faecalis is usually isolated in chronic apical periodontitis. The aim of this study was to evaluate the effectiveness and mechanical safety of cold plasma therapy in disinfecting 3-week E. faecalis biofilms. Teeth with 3-week E. faecalis biofilm were treated with AC argon/oxygen (Ar/O2) cold plasma for various treatment times and compared with those treated with Ca(OH)2, 2% chlorhexidine gel, and Ca(OH)2/chlorhexidine for a week. Antimicrobial efficacy was assessed by colony-forming unit method. Scanning electron microscopy was used to assess the morphologic changes of E. faecalis biofilm by plasma. Confocal laser scanning microscopy was used to confirm the viability of the biofilm after the plasma treatment. Microhardness and roughness changes of root canal dentin caused by plasma were verified with Vickers Hardness Tester and 3D Profile Measurement Laser Microscope, respectively. There were no detectable live bacteria after 12 minutes of cold plasma treatment. This was further confirmed by scanning electron microscopy and confocal laser scanning microscopy results. Microhardness and roughness of root canal dentin showed no significant difference after plasma treatment. Atmospheric pressure cold plasma is an effective therapy in endodontics for its strong sterilization effect on fully matured biofilm within a few minutes. Meanwhile, it has an accepted mechanical safety for its low temperature and not affecting the microhardness and roughness of root canal dentin significantly. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. Decolonisation of MRSA, S. aureus and E. coli by cold-atmospheric plasma using a porcine skin model in vitro.

    Directory of Open Access Journals (Sweden)

    Tim Maisch

    Full Text Available In the last twenty years new antibacterial agents approved by the U.S. FDA decreased whereas in parallel the resistance situation of multi-resistant bacteria increased. Thus, community and nosocomial acquired infections of resistant bacteria led to a decrease in the efficacy of standard therapy, prolonging treatment time and increasing healthcare costs. Therefore, the aim of this work was to demonstrate the applicability of cold atmospheric plasma for decolonisation of Gram-positive (Methicillin-resistant Staphylococcus aureus (MRSA, Methicillin-sensitive Staphylococcus aureus and Gram-negative bacteria (E. coli using an ex vivo pig skin model. Freshly excised skin samples were taken from six month old female pigs (breed: Pietrain. After application of pure bacteria on the surface of the explants these were treated with cold atmospheric plasma for up to 15 min. Two different plasma devices were evaluated. A decolonisation efficacy of 3 log(10 steps was achieved already after 6 min of plasma treatment. Longer plasma treatment times achieved a killing rate of 5 log(10 steps independently from the applied bacteria strains. Histological evaluations of untreated and treated skin areas upon cold atmospheric plasma treatment within 24 h showed no morphological changes as well as no significant degree of necrosis or apoptosis determined by the TUNEL-assay indicating that the porcine skin is still vital. This study demonstrates for the first time that cold atmospheric plasma is able to very efficiently kill bacteria applied to an intact skin surface using an ex vivo porcine skin model. The results emphasize the potential of cold atmospheric plasma as a new possible treatment option for decolonisation of human skin from bacteria in patients in the future without harming the surrounding tissue.

  17. The effect of organochlorines and heavy metals on sex steroid-binding proteins in vitro in the plasma of nesting green turtles, Chelonia mydas.

    Science.gov (United States)

    Ikonomopoulou, Maria Petrou; Olszowy, Henry; Hodge, Mary; Bradley, Adrian J

    2009-07-01

    In this study on green turtles, Chelonia mydas, from Peninsular Malaysia, the effect of selected environmental toxicants was examined in vitro. Emphasis was placed on purported hormone-mimicking chemicals such as dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene, dieldrin, lead, zinc and copper. Five concentrations were used: high (1 mg/L), medium (10(-1) mg/L), low (10(-2) mg/L), very low (10(-6) mg/L) and control (diluted carrier solvent but no toxicants). The results suggest that environmental pesticides and heavy metals may significantly alter the binding of steroids [i.e. testosterone (T) and oestradiol] to the plasma proteins in vitro. Competition studies showed that only Cu competed for binding sites with testosterone in the plasma collected from nesting C. mydas. Dieldrin and all heavy metals competed with oestradiol for binding sites. Furthermore, testosterone binding affinity was affected at various DDT concentrations and was hypothesised that DDT in vivo may act to inhibit steroid-protein interactions in nesting C. mydas. Although the precise molecular mechanism is yet to be described, DDT could have an effect upon the protein conformation thus affecting T binding (e.g. the T binding site on the steroid hormone binding protein molecule).

  18. Plasma components and platelet activation are essential for the antimicrobial properties of autologous platelet-rich plasma: an in vitro study.

    Directory of Open Access Journals (Sweden)

    Lorenzo Drago

    Full Text Available Autologous platelet concentrates are successfully adopted in a variety of medical fields to stimulate bone and soft tissue regeneration. The rationale for their use consists in the delivery of a wide range of platelet-derived bioactive molecules that promotes wound healing. In addition, antimicrobial properties of platelet concentrates have been pointed out. In this study, the effect of the platelet concentration, of the activation step and of the presence of plasmatic components on the antimicrobial activity of pure platelet-rich plasma was investigated against gram positive bacteria isolated from oral cavity. The antibacterial activity, evaluated as the minimum inhibitory concentration, was determined through the microdilution two-fold serial method. Results seem to suggest that the antimicrobial activity of platelet-rich plasma against Enterococcus faecalis, Streptococcus agalactiae, Streptococcus oralis and Staphylococcus aureus is sustained by a co-operation between plasma components and platelet-derived factors and that the activation of coagulation is a fundamental step. The findings of this study may have practical implications in the modality of application of platelet concentrates.

  19. Polyionic complexes of butyrylcholinesterase and poly-l-lysine-g-poly(ethylene glycol): Comparative kinetics of catalysis and inhibition and in vitro inactivation by proteases and heat.

    Science.gov (United States)

    Hester, Kirstin; Liu, Jing; Flynn, Nicholas; Sultatos, Lester G; Geng, Liyi; Brimijoin, Stephen; Ramsey, Joshua D; Hartson, Steven; Ranjan, Ashish; Pope, Carey

    2017-09-25

    We previously reported that recombinant human butyrylcholinesterase (rhBChE) complexed with a series of copolymers of poly-l-lysine (PLL) with grafted (polyethylene) glycol (PEG) (i.e., PLL-g-PEG) showed reduced catalytic activity but relatively similar concentration-dependent inactivation of the organophosphorus inhibitor paraoxon. Herein, we compared the kinetics of catalysis (using butyrylthiocholine as the substrate) and inhibition (using four different inhibitors) of free and copolymer-complexed rhBChE. Using scanning electron microscopy, polyionic complexes of rhBChE with three different PLL-g-PEG copolymers (based on PLL size) appeared as spheroid-shaped particles with relatively similar particle sizes (median diameter = 35 nm). Relatively similar particle sizes were also noted using dynamic light scattering (mean = 26-35 nm). The three copolymer-complexed enzymes exhibited reduced kcat (30-33% reduction), but no significant changes in Km. Inhibitory potency (as reflected by the bimolecular rate constant, ki) was similar among the free and copolymer-complexed enzymes when paraoxon was the inhibitor, whereas statistically significant reductions in ki (16-60%) were noted with the other inhibitors. Sensitivity to inactivation by proteases and heat was also compared. Copolymer-complexed enzymes showed lesser time-dependent inactivation by the proteases trypsin and pronase and by heat compared to the free enzyme. Understanding the unique properties of PLL-g-PEG-BChE complexes may lead to enhanced approaches for use of BChE and other protein bioscavengers. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Inactivation of Herpes Simplex Viruses by Nonionic Surfactants

    Science.gov (United States)

    Asculai, Samuel S.; Weis, Margaret T.; Rancourt, Martha W.; Kupferberg, A. B.

    1978-01-01

    Nonionic surface-active agents possessing ether or amide linkages between the hydrophillic and hydrophobic portions of the molecule rapidly inactivated the infectivity of herpes simplex viruses. The activity stemmed from the ability of nonionic surfactants to dissolve lipid-containing membranes. This was confirmed by observing surfactant destruction of mammalian cell plasma membranes and herpes simplex virus envelopes. Proprietary vaginal contraceptive formulations containing nonionic surfactants also inactivated herpes simplex virus infectivity. This observation suggests that nonionic surfactants in appropriate formulation could effectively prevent herpes simplex virus transmission. Images PMID:208460

  1. Effects of Rutin and Hesperidin and Their Al(III and Cu(II Complexes on in Vitro Plasma Coagulation Assays

    Directory of Open Access Journals (Sweden)

    Vesna Kuntić

    2011-02-01

    Full Text Available Two flavonoids, rutin and hesperidin, were investigated in vitro for anticoagulant activity through coagulation tests: activated partial thromboplastin time (aPTT, prothrombin time (PT and thrombin time (TT. Only an ethanolic solution of rutin at the concentration of 830 µM prolonged aPTT, while TT and PT were unaffected. In order to evaluate whether the prolongation of aPTT was due to the decrease of coagulation factors, the experiment with deficient plasma was performed, showing the effects on factors VIII and IX. Since pharmacological activity of flavonoids is believed to increase when they are coordinated with metal ions, complexes of these flavonoids with Al(III and Cu(II ions were also tested. The results showed that complexes significantly prolonged aPTT and had no effects on PT and TT. Assay with deficient plasma (plasma having the investigated factor at less then 1% revealed that complexes could bind to the coagulation factors, what may lead to a non-specific inhibition and aPTT prolongation. An effort was made to correlate stability of complexes with their anticoagulant properties.

  2. Drosophila QVR/SSS modulates the activation and C-type inactivation kinetics of Shaker K(+) channels.

    Science.gov (United States)

    Dean, Terry; Xu, Rong; Joiner, William; Sehgal, Amita; Hoshi, Toshinori

    2011-08-03

    The quiver/sleepless (qvr/sss) gene encodes a small, glycosylphosphatidylinositol-anchored protein that plays a critical role in the regulation of sleep in Drosophila. Loss-of-function mutations in qvr/sss severely suppress sleep and effect multiple changes in in situ Shaker K(+) currents, including decreased magnitude, slower time-to-peak, and cumulative inactivation. Recently, we demonstrated that SLEEPLESS (SSS) protein modulates Shaker channel activity, possibly through a direct interaction at the plasma membrane. We show here that SSS accelerates the activation of heterologously expressed Shaker channels with no effect on deactivation or fast N-type inactivation. Furthermore, this SSS-induced acceleration is sensitive to the pharmacological disruption of lipid rafts and sufficiently accounts for the slower time-to-peak of in situ Shaker currents seen in qvr/sss mutants. We also find that SSS decreases the rate of C-type inactivation of heterologously expressed Shaker channels, providing a potential mechanism for the cumulative inactivation phenotype induced by qvr/sss loss-of-function mutations. Kinetic modeling based on the in vitro results suggests that the SSS-dependent regulation of channel kinetics accounts for nearly 40% of the decrease in Shaker current magnitude in flies lacking SSS. Sleep duration in qvr/sss-null mutants is restored to normal by a qvr/sss transgene that fully rescues the Shaker kinetic phenotypes but only partially rescues the decrease in current magnitude. Together, these results suggest that the role of SSS in the regulation of sleep in Drosophila correlates more strongly with the effects of SSS on Shaker kinetics than current magnitude.

  3. In vitro bactericidal efficacy of atmospheric-pressure plasma jet on titanium-based implant infected with Staphylococcus aureus

    Science.gov (United States)

    Park, Young-Ouk; Lee, Chang-Min; Kim, Myung-Sun; Jung, Sang-Chul; Yang, Seong-Won; Kook, Min-Suk; Kim, Byung-Hoon

    2017-01-01

    Staphylococcus aureus is a representative of gram-positive bacteria that causes skin infection, respiratory diseases, and burned tissue infections. The aim of this study was to evaluate the sterilizing efficiency of an atmospheric-pressure plasma jet (APPJ) on S. aureus adhered on a titanium surface. During the APPJ sterilization, the plasma gases used were Ar, Ar+N2, and Ar+O2. With increasing APPJ treatment time, the viability of S. aureus decreased. The addition of O2 gas to Ar gas resulted in a higher sterilizing efficiency than the addition of other groups. Plasma exposure induced bacterial oxidative stress, and it was confirmed that the cell membrane was seriously damaged by the production of reactive oxygen species. Our finding suggests that the APPJ is an effective tool for clinical antimicrobial therapy.

  4. Inactivation of Microorganisms

    Science.gov (United States)

    Alzamora, Stella Maris; Guerrero, Sandra N.; Schenk, Marcela; Raffellini, Silvia; López-Malo, Aurelio

    Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, and ultraviolet light). These technologies have been reported to reduce microorganism population in foods while avoiding the deleterious effects of severe heating on quality. Among technologies, high-energy ultrasound (i.e., intensities higher than 1 W/cm2, frequencies between 18 and 100 kHz) has attracted considerable interest for food preservation applications (Mason et al., 1996; Povey and Mason, 1998).

  5. Surface bioactivity modification of titanium by CO{sub 2} plasma treatment and induction of hydroxyapatite: In vitro and in vivo studies

    Energy Technology Data Exchange (ETDEWEB)

    Hu Xixue [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China); Shen Hong [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Shuai Kegang [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang Enwei [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China); Bai Yanjie; Cheng Yan; Xiong Xiaoling [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wang Shenguo [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Fang Jing, E-mail: jfang@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School of Stomatology, Peking University, Beijing 100081 (China)

    2011-01-01

    Since metallic biomaterials used for orthopedic and dental implants possess a paucity of reactive functional groups, bioactivity modification of these materials is challenging. In the present work, the titanium discs and rods were treated with carbon dioxide plasma and then incubated in a modified simulated body fluid 1.5SBF to obtain a hydroxyapatite layer. Surface hydrophilicity of samples, changes of surface chemistry, surface morphologies of samples, and structural analysis of formed hydroxyapatite were investigated by contact angle to water, X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The results demonstrated that hydrophilicity of titanium surface was improved and hydroxyl groups increased after modification with carbon dioxide plasma treatment. The hydroxyl groups on the surface of titanium were the richest after carbon dioxide plasma treatment under the condition of 20 W for less than 30 s. The hydroxyapatite formability of titanium surface was enhanced by carbon dioxide plasma pretreatment, which was attributed to the surface chemistry. MC3T3-E1 cell as a model cell was cultured on the Ti, CPT-Ti and CPT/SBF-Ti discs in vitro, and the results of the morphology and differentiation of the cell showed that CPT/SBF-Ti was the highest bioactive. The relative parameters of the new bone around the Ti and CPT/SBF-Ti rods including bone mineral density (BMD), a ratio of bone volume to total volume (BV/TV), trabecular thickness (Tb.Th.) and trabecular number (Tb.N.) were analyzed by a micro-computed tomography (micro-CT) after 4-, 8- and 12-week implantation periods in vivo. The results indicated that the CPT/SBF-Ti was more advantageous for new bone formation.

  6. In vitro and in vivo microbial adhesion and growth on argon plasma-treated silicone rubber voice prostheses

    NARCIS (Netherlands)

    Everaert, EPJM; Van de Belt-Gritter, B; Van der Mei, HC; Busscher, HJ; Verkerke, GJ; Dijk, F; Mahieu, HF; Reitsma, A

    Patients who undergo a total laryngectomy usually receive a silicone rubber voice prosthesis for voice rehabilitation. Unfortunately, biofilm formation on the esophageal side of voice prostheses limits their lifetime to 3-4 mon on average. The effects of repeated argon plasma treatment of medical

  7. Effect of seminal plasma removal before cryopreservation of bovine semen obtained by electroejaculation on semen quality and in vitro fertility.

    Science.gov (United States)

    Campanholi, Suzane Peres; Monteiro, Fabio Morato; Ribeiro Dias, Erika Aline; Mercadante, Maria Eugênia Zerlotti; de Paz, Claudia Cristina Paro; Dell'Aqua Junior, José Antonio; Papa, Frederico Ozanam; Dell'Aqua, Camila de Paula Freitas; Vantini, Roberta; Garcia, Joaquim Mansano

    2017-02-01

    Cryopreservation of bull semen is a common biotechnology procedure in cattle breeding. However, when the ejaculate is obtained by electroejaculation, wide variation is observed in the sperm/seminal plasma (SP) ratio that can affect the freezability of semen in this species. The removal of SP may improve the quality of frozen bull semen. The objective of this study was to evaluate the effect of SP removal from the ejaculate on the cryopreservation of semen from 38 Nellore bulls collected by electroejaculation. After collection, the ejaculate was divided into three aliquots: (1) control (N) diluted to a concentration of 60 × 10(6) spermatozoa/mL and frozen with SP; (2) centrifugation (C) at ×600g for 10 minutes and the pellet resuspended and frozen at the same concentration as N; and (3) filtration (F) through SpermFilter and sperm recovered and frozen at the same concentration as N. After thawing, sperm kinetics, plasma and acrosome membrane integrity, mitochondrial membrane potential, oxidative stress, and in vitro fertility were evaluated. Statistical analysis was performed using the SAS 9.2 package, and differences were considered significant when P < 0.05. Higher average path velocity and straight-line velocity were observed in the groups submitted to SP removal compared to the control group (P < 0.01). In contrast, filtered samples exhibited higher beat cross frequency, straightness, and linearity compared to the other groups. Plasma membrane integrity was reduced when SP was removed, but lower oxidative stress was observed in groups C and F (34.91 ± 2.95% and 31.63 ± 2.95%, respectively) compared to group N (57.39 ± 2.95%). However, the percentage of hatched blastocysts was similar in the N and F groups (21.22 ± 1.05% and 24.00 ± 1.05%, respectively) and higher compared to group C (18.83 ± 1.05%). In conclusion, removal of SP by centrifugation for bull semen freezing reduced the rate of in vitro-produced embryos, whereas filtration of

  8. Comparison of bond strength between orthodontic brackets bonded with halogen and plasma arc curing lights: an in-vitro and in-vivo study.

    Science.gov (United States)

    Signorelli, Michael D; Kao, Elizabeth; Ngan, Peter W; Gladwin, Marcia A

    2006-02-01

    This study assessed in-vitro shear bond strength and in-vivo survival rate of orthodontic brackets bonded with either a halogen or a plasma arc light. Ninety extracted premolars were divided into 6 groups of 15. Stainless steel brackets were bonded to the teeth by using either a halogen light with a 20-second curing time or a plasma arc light with a 2-, 6-, or 10-second curing time. Brackets were debonded either within 30 minutes of bonding or after thermocycling for 24 hours. Bond strengths were tested on a testing machine at a crosshead speed of 1 mm/minute. The bracket failure interface was measured with a modified adhesive remnant index score. Data were analyzed by using ANOVA and Tukey-Kramer multiple comparison tests. For the in-vivo study, a split-arch design was used to determine the bracket-failure rate and distribution in 25 patients. The patients were followed for a mean period of 1.1 years (386 days). Survival analysis was carried out to compare the failure rates of the 2 techniques. No significant differences in bond strengths were found 30 minutes after bonding between the halogen light (13.6 +/- 3.8 MPa) and the plasma arc light with 2-, 6-, or 10-second curing times (9.6 +/- 2.9, 14.2 +/- 4.6, 16.0 +/- 3.0 MPa, respectively). Similar bond strengths were also found between the halogen light with a 20-second (16.1 +/- 3.6 MPa) curing time and plasma arc light with 6 seconds (18.2 +/- 4.6 MPa) of curing time after 24 hours of thermocycling. For the in-vivo study, no significant difference was found in bracket failure rates between the 2 light sources (4.9% in both groups). No significant differences were found between ARI scores for the halogen light and the plasma arc light at either 30 minutes or 24 hours after debonding. These results indicate that the plasma arc light with a 6-second curing time can produce similar bond strength and bracket-failure rates as the halogen light that requires a longer curing time.

  9. In vitro evaluation of microleakage under ceramic and metal brackets bonded with LED and plasma arc curing.

    Science.gov (United States)

    Davari, Abdolrahim; Yassaei, Soghra; Karandish, Mariam; Zarghami, Fateme

    2012-09-01

    The aim of the present study was to evaluate these two high intensity light curing units regarding microleakage beneath metal and ceramic brackets. A total of 60 freshly extracted human premolar teeth were randomly divided into four groups of 15 samples; group I: Metal bracket + LED cured, group II: Ceramic bracket + LED cured, group III: Metal bracket + plasma arc cured, group IV: Ceramic bracket + plasma arc cured. After photopolymerization, the teeth were immersed in water and thermocycled (500 cycles between 5 and 55). Specimens were further sealed with nail varnish and stained with 5% basic fuchsin for 24 hours. All of the teeth were sectioned with two parallel longitudinal occlusogingival cuts and examined under a stereomicroscope. The microleakage was measured with a digital caliper and scored from 0 to 3 for marginal microleakage at the bracket-adhesive and adhesive-enamel interfaces from both the occlusal and gingival margins. Microleakage was detected in all groups. The plasma arc cured group showed less microleakage than light emitting diode (LED) cured in all samples at the enamel-adhesive interface at the gingival margin (ceramic brackets, p = 0.009 and metal brackets, p = 0.005). The plasma arc cured samples showed less microleakage than LED cured in metal brackets at the adhesive-brackets interface at the occlusal margin (p = 0.033). While curing with an LED unit, ceramic brackets displayed significantly less microleakage than metal ones at the gingival margin of adhesive-enamel interface (p = 0.013). The gingival margin in all groups exhibited higher microleakage compared with those observed in occlusal sides in all sample groups (p plasma arc units. 2. In all groups the microleakage at the gingival margin is greater than the occlusal margin. The microleakage formation permits the passage of bacteria and oral fluids initiating white spot lesions beneath the bracket base.

  10. In vitro biocompatibility of plasma-aided surface-modified 316L stainless steel for intracoronary stents.

    Science.gov (United States)

    Bayram, Cem; Mizrak, Alpay Koray; Aktürk, Selçuk; Kurşaklioğlu, Hurkan; Iyisoy, Atila; Ifran, Ahmet; Denkbaş, Emir Baki

    2010-10-01

    316L-type stainless steel is a raw material mostly used for manufacturing metallic coronary stents. The purpose of this study was to examine the chemical, wettability, cytotoxic and haemocompatibility properties of 316L stainless steel stents which were modified by plasma polymerization. Six different polymeric compounds, polyethylene glycol, 2-hydroxyethyl methacrylate, ethylenediamine, acrylic acid, hexamethyldisilane and hexamethyldisiloxane, were used in a radio frequency glow discharge plasma polymerization system. As a model antiproliferative drug, mitomycin-C was chosen for covalent coupling onto the stent surface. Modified SS 316L stents were characterized by water contact angle measurements (goniometer) and x-ray photoelectron spectroscopy. C1s binding energies showed a good correlation with the literature. Haemocompatibility tests of coated SS 316L stents showed significant latency (t-test, p < 0.05) with respect to SS 316L and control groups in each test.

  11. In vitro biocompatibility of plasma-aided surface-modified 316L stainless steel for intracoronary stents

    Energy Technology Data Exchange (ETDEWEB)

    Bayram, Cem; Denkbas, Emir Baki [Nanotechnology and Nanomedicine Division, The Institute For Graduate Studies in Science and Engineering, Hacettepe University, 06800, Ankara (Turkey); Mizrak, Alpay Koray [Institute of Materials Science and Nanotechnology, Bilkent University, UNAM, 06800, Ankara (Turkey); Aktuerk, Selcuk [Department of Physics, Mugla University, 48000 Koetekli, Mugla (Turkey); Kursaklioglu, Hurkan; Iyisoy, Atila [Department of Cardiology, School of Medicine, Gulhane Military Medicine Academy, 06018, Ankara (Turkey); Ifran, Ahmet, E-mail: denkbas@hacettepe.edu.t [Department of Hematology, School of Medicine, Gulhane Military Medicine Academy, 06018, Ankara (Turkey)

    2010-10-01

    316L-type stainless steel is a raw material mostly used for manufacturing metallic coronary stents. The purpose of this study was to examine the chemical, wettability, cytotoxic and haemocompatibility properties of 316L stainless steel stents which were modified by plasma polymerization. Six different polymeric compounds, polyethylene glycol, 2-hydroxyethyl methacrylate, ethylenediamine, acrylic acid, hexamethyldisilane and hexamethyldisiloxane, were used in a radio frequency glow discharge plasma polymerization system. As a model antiproliferative drug, mitomycin-C was chosen for covalent coupling onto the stent surface. Modified SS 316L stents were characterized by water contact angle measurements (goniometer) and x-ray photoelectron spectroscopy. C1s binding energies showed a good correlation with the literature. Haemocompatibility tests of coated SS 316L stents showed significant latency (t-test, p < 0.05) with respect to SS 316L and control groups in each test.

  12. Effect of Fast Curing Lights, Argon Laser, and Plasma Arc on Bond Strengths of Orthodontic Brackets: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    M. Hashem-Hoseini

    2008-12-01

    Full Text Available Objective: Nowadays light-cured composites are used widely by orthodontists to bond brackets. As these composites require 20-40 seconds time per tooth to be light cured, more chair-time in needed compared to self-cured composites. In recent years, the argon laser and plasma arc lights have been introduced in dentistry to reduce this curing time. The purpose of this study was to compare bond strength of brackets bonded with the argon la-ser and plasma arc light with those bonded with the conventional halogen light.Materials and Methods: Fifty-one intact human premolars were randomly divided into three groups of 17 teeth each. Stainless steel twin premolar brackets (018- in Dyna lock, 3M Unitek were bonded to the teeth using one of these curing devices in each group: the halogen unit (Coltolux 75, Switzerland, the argon laser unit (Bo-5, Iran , and the plasma arc unit (Remecure 15, Belgium. The orthodontic adhesive was the same in the three groups (Transbond XT, 3M Unitek. After thermal cycling, the diametral tensilebond strength of specimens was measured using a debonding plier in a Zwick Universal Testing machine (Z/100, Germany.Results: The mean bond strengths was 17.344 MPa (SD=4.567 for halogen 19.172 MPa(SD=6.328 for laser and 19.322 MPa (SD=4.036 for plasma arc groups. No statistically significant difference existed in the mean bond strengths among three groups.Conclusion: Argon laser lights, significantly reducing the curing time of orthodonticbrackets without affecting bond strength, have the potential to be considered as advanta-geous alternatives to conventional halogen light.

  13. Inactivation of complement by Loxosceles reclusa spider venom.

    Science.gov (United States)

    Gebel, H M; Finke, J H; Elgert, K D; Cambell, B J; Barrett, J T

    1979-07-01

    Zymosan depletion of serum complement in guinea pigs rendered them highly resistant to lesion by Loxosceles reclusa spider venom. Guinea pigs deficient in C4 of the complement system are as sensitive to the venom as normal guinea pigs. The injection of 35 micrograms of whole recluse venom intradermally into guinea pigs lowered their complement level by 35.7%. Brown recluse spider venom in concentrations as slight as 0.02 micrograms protein/ml can totally inactivate one CH50 of guinea pig complement in vitro. Bee, scorpion, and other spider venoms had no influence on the hemolytic titer of complement. Fractionation of recluse spider venom by Sephadex G-200 filtration separated the complement-inactivating property of the venom into three major regions which could be distinguished on the basis of heat stability as well as size. None was neutralized by antivenom. Polyacrylamide gel electrophoresis of venom resolved the complement inactivators into five fractions. Complement inactivated by whole venom or the Sephadex fractions could be restored to hemolytic activity by supplements of fresh serum but not by heat-inactivated serum, pure C3, pure C5, or C3 and C5 in combination.

  14. A simple method for assessing free brain/free plasma ratios using an in vitro model of the blood brain barrier.

    Directory of Open Access Journals (Sweden)

    Maxime Culot

    Full Text Available Historically, the focus has been to use in vitro BBB models to optimize rate of drug delivery to the CNS, whereas total in vivo brain/plasma ratios have been used for optimizing extent. However, these two parameters do not necessarily show good correlations with receptor occupancy data or other pharmacological readouts. In line with the free drug hypothesis, the use of unbound brain concentrations (Cu,br has been shown to provide the best correlations with pharmacological data. However, typically the determination of this parameter requires microdialysis, a technique not ideally suited for screening in early drug development. Alternative, and less resource-demanding methodologies to determine Cu,br employ either equilibrium dialysis of brain homogenates or incubations of brain slices in buffer to determine fraction unbound brain (fu,br, which is subsequently multiplied by the total brain concentration to yield Cu,br. To determine Cu,br/Cu,pl ratios this way, still requires both in vitro and in vivo experiments that are quite time consuming. The main objective of this study was to explore the possibility to directly generate Cu,br/Cu,pl ratios in a single in vitro model of the BBB, using a co-culture of brain capillary endothelial and glial cells in an attempt to mimick the in vivo situation, thereby greatly simplifying existing experimental procedures. Comparison to microdialysis brain concentration profiles demonstrates the possibility to estimate brain exposure over time in the BBB model. A stronger correlation was found between in vitro Cu,br/Cu,pl ratios and in vivo Cu,br/Cu,pl obtained using fu,br from brain slice than with fu,br from brain homogenate for a set of 30 drugs. Overall, Cu,br/Cu,pl ratios were successfully predicted in vitro for 88% of the 92 studied compounds. This result supports the possibility to use this methodology for identifying compounds with a desirable in vivo response in the CNS early on in the drug discovery

  15. Cryosurvival and in vitro fertilizing capacity postthaw is improved when boar spermatozoa are frozen in the presence of seminal plasma from good freezer boars.

    Science.gov (United States)

    Hernández, Marta; Roca, Jordi; Calvete, Juan J; Sanz, Libia; Muiño-Blanco, Teresa; Cebrián-Pérez, José A; Vázquez, Juan M; Martínez, Emilio A

    2007-01-01

    The study evaluated the protective effect of seminal plasma (SP) added to freezing extender against cryopreservation injuries to boar spermatozoa. Pooled sperm-rich fractions collected from 9 fertile boars were frozen in 0.5-mL straws after being extended in a conventional freezing extender either alone or supplemented with 5% of SPs (SP1-SP4) collected from the sperm-rich fractions (diluted 1:1, vol/vol, in Beltsville Thawing Solution extender) from 4 boars (1-4) with known sperm cryosurvival (poor, moderate, and good sperm freezers). Cryopreservation injuries were assessed in terms of postthaw sperm motility (assessed by computer-assisted sperm analysis), viability (plasma membrane and acrosome integrity assessed simultaneously by flow cytometry), membrane lipid peroxidation (malondialdehyde [MDA] production), and the ability of thawed spermatozoa to fertilize in vitro-matured homologous oocytes. The addition of SP from good sperm freezers (SP3 and SP4) improved (P freezers also increased (P < .05) the percentage of penetrated (SP3) and polyspermic oocytes (SP4) with respect to the control. Neither the total amount of SP proteins, protein profiles, nor antioxidant capacity of the different SPs were related to the various cryosurvival/fertilizing capacities of the processed spermatozoa.

  16. Cold atmospheric plasma (CAP changes gene expression of key molecules of the wound healing machinery and improves wound healing in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Stephanie Arndt

    Full Text Available Cold atmospheric plasma (CAP has the potential to interact with tissue or cells leading to fast, painless and efficient disinfection and furthermore has positive effects on wound healing and tissue regeneration. For clinical implementation it is necessary to examine how CAP improves wound healing and which molecular changes occur after the CAP treatment. In the present study we used the second generation MicroPlaSter ß® in analogy to the current clinical standard (2 min treatment time in order to determine molecular changes induced by CAP using in vitro cell culture studies with human fibroblasts and an in vivo mouse skin wound healing model. Our in vitro analysis revealed that the CAP treatment induces the expression of important key genes crucial for the wound healing response like IL-6, IL-8, MCP-1, TGF-ß1, TGF-ß2, and promotes the production of collagen type I and alpha-SMA. Scratch wound healing assays showed improved cell migration, whereas cell proliferation analyzed by XTT method, and the apoptotic machinery analyzed by protein array technology, was not altered by CAP in dermal fibroblasts. An in vivo wound healing model confirmed that the CAP treatment affects above mentioned genes involved in wound healing, tissue injury and repair. Additionally, we observed that the CAP treatment improves wound healing in mice, no relevant side effects were detected. We suggest that improved wound healing might be due to the activation of a specified panel of cytokines and growth factors by CAP. In summary, our in vitro human and in vivo animal data suggest that the 2 min treatment with the MicroPlaSter ß® is an effective technique for activating wound healing relevant molecules in dermal fibroblasts leading to improved wound healing, whereas the mechanisms which contribute to these observed effects have to be further investigated.

  17. Plasma anti-Müllerian hormone as a predictive endocrine marker to select Bos taurus (Holstein) and Bos indicus (Nelore) calves for in vitro embryo production.

    Science.gov (United States)

    Batista, E O S; Guerreiro, B M; Freitas, B G; Silva, J C B; Vieira, L M; Ferreira, R M; Rezende, R G; Basso, A C; Lopes, R N V R; Rennó, F P; Souza, A H; Baruselli, P S

    2016-01-01

    This study evaluated the association between plasma anti-Müllerian hormone (AMH) concentrations and in vitro embryo production in Bos indicus (Nelore; experiment 1) and Bos taurus (Holstein; experiment 2) calves superstimulated or not with 140 mg of porcine follicle-stimulating hormone (pFSH; 4 decreasing doses twice daily). Oocytes were recovered from calves aged 2 to 4 mo after receiving gonadotropin stimulation (Nelore, n = 15; Holstein, n = 12) or not (Nelore, n = 15; Holstein, n = 12). Cycling heifers formed a positive control group (n = 15 for Nelore [aged 18-24 mo], n = 10 for Holstein [aged 14-16 mo]). All the calves underwent laparoscopic ovum pickup, and cycling heifers underwent a regular transvaginal ultrasound-guided ovum pickup for oocyte recovery. Immediately before oocyte retrieval, blood samples were taken for subsequent AMH determination (ng/mL). Regardless of the genetic group, calves that received pFSH (3.6 ± 1.1 in Nelore and 4.6 ± 1.2 in Holstein) or did not receive pFSH (3.2 ± 1.0 in Nelore and 2.5 ± 0.8 in Holstein) had greater plasma AMH concentrations (P = 0.01 in Nelore and P = 0.003 in Holstein) than cycling heifers (1.1 ± 0.2 in Nelore and 0.6 ± 0.07 in Holstein). AMH concentrations in calves with or without pFSH were similar in both genetic groups (3.6 ± 1.1 vs 3.2 ± 1.0 in Nelore; 4.6 ± 1.2 vs 2.5 ± 0.8 in Holstein). In calves, positive correlations were observed between plasma AMH concentrations and the numbers of follicles >2 mm (r = 0.86, P taurus calves. Therefore, AMH is a promising tool for selecting oocyte donor calves to maximize results during in vitro embryo production. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Photodynamic inactivation of pathogens causing infectious keratitis

    Science.gov (United States)

    Simon, Carole; Wolf, G.; Walther, M.; Winkler, K.; Finke, M.; Hüttenberger, D.; Bischoff, Markus; Seitz, B.; Cullum, J.; Foth, H.-J.

    2014-03-01

    The increasing prevalence of antibiotic resistance requires new approaches also for the treatment of infectious keratitis. Photodynamic Inactivation (PDI) using the photosensitizer (PS) Chlorin e6 (Ce6) was investigated as an alternative to antibiotic treatment. An in-vitro cornea model was established using porcine eyes. The uptake of Ce6 by bacteria and the diffusion of the PS in the individual layers of corneal tissue were investigated by fluorescence. After removal of the cornea's epithelium Ce6-concentrations keratitis patients were tested in liquid culture against different concentrations of Ce6 (1 - 512 μM) using 10 minutes irradiation (E = 18 J/cm2 ). This demonstrated that a complete inactivation of the pathogen strains were feasible whereby SA was slightly more susceptible than PA. 3909 mutants of the Keio collection of Escherichia coli (E.coli) were screened for potential resistance factors. The sensitive mutants can be grouped into three categories: transport mutants, mutants in lipopolysaccharide synthesis and mutants in the bacterial SOS-response. In conclusion PDI is seen as a promising therapy concept for infectious keratitis.

  19. Hydrolysis of plasma triacylglycerol-rich lipoproteins from immature and laying hens (Gallus domesticus) by lipoprotein lipase in vitro.

    Science.gov (United States)

    Griffin, H; Grant, G; Perry, M

    1982-01-01

    Very-low-density (VLD) lipoproteins and portomicrons were isolated from the plasma of immature and laying hens and their size, lipid composition and susceptibility to hydrolysis by lipoprotein lipase were compared. In agreement with other studies, VLD lipoproteins from laying hens were found to be smaller and have a different lipid composition than VLD lipoproteins from immature hens. Portomicrons from immature and laying hens had mean diameters of about 150 nm and similar lipid compositions. Hydrolysis of VLD lipoproteins from immature hens, and portomicrons from immature and laying hens, proceeded rapidly until at least 40% of the substrate had been used. In contrast only 1--15% of laying-hen VLD-lipoprotein triacylglycerol was readily hydrolysis occurred slowly. The limited susceptibility of laying-hen VLD lipoproteins appeared to be due to their low content of lipoprotein lipase activator apoprotein, which occurred despite an abundance of activator in the high-density lipoproteins of laying-hen plasma. The results provide further evidence that the liver of the laying hen synthesizes specialized lipoproteins. Their limited susceptibility to hydrolysis by lipoprotein lipase is probably a major factor in ensuring transport of lipid to yolk rather than to other tissues. The form of transport of dietary lipid, however, is similar in immature and laying hens. PMID:7150269

  20. Effect of the pulmonary deposition and in vitro permeability on the prediction of plasma levels of inhaled budesonide formulation.

    Science.gov (United States)

    Salar-Behzadi, Sharareh; Wu, Shengqian; Mercuri, Annalisa; Meindl, Claudia; Stranzinger, Sandra; Fröhlich, Eleonore

    2017-10-30

    The growing interest in the inhalable pharmaceutical products requires advanced approaches to safe and fast product development, such as in silico tools that can be used for estimating the bioavailability and toxicity of developed formulation. GastroPlus™ is one of the few available software packages for in silico simulation of PBPK profile of inhalable products. It contains a complementary module for calculating the lung deposition, the permeability and the systemic absorption of inhalable products. Experimental values of lung deposition and permeability can also be used. This study aims to assess the efficiency of simulation by applying experimental permeability and deposition values, using budesonide as a model substance. The lung deposition values were obtained from the literature, the lung permeability data were experimentally determined by culturing Calu-3 cells under air-liquid interface and submersed conditions to morphologically resemble bronchial and alveolar epithelial cells, respectively. A two-compartment PK model was created for i.v. administration and used as a background for the in silico simulation of the plasma profile of budesonide after inhalation. The predicted plasma profile was compared with the in vivo data from the literature and the effects of experimental lung deposition and permeability on prediction were assessed. The developed model was significantly improved by using realistic lung deposition data combined with experimental data for peripheral permeability. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Viral inactivation in hemotherapy: systematic review on inactivators with action on nucleic acids

    Directory of Open Access Journals (Sweden)

    Patricia Marial Sobral

    2012-01-01

    Full Text Available The aim of this study was to conduct a systematic review on the photoinactivators used in hemotherapy, with action on viral genomes. The SciELO, Science Direct, PubMed and Lilacs databases were searched for articles. The inclusion criterion was that these should be articles on inactivators with action on genetic material that had been published between 2000 and 2010. The key words used in identifying such articles were "hemovigilance", "viral inactivation", "photodynamics", "chemoprevention" and "transfusion safety". Twenty-four articles on viral photoinactivation were found with the main photoinactivators covered being: methylene blue, amotosalen HCl, S-303 frangible anchor linker effector (FRALE, riboflavin and inactin. The results showed that methylene blue has currently been studied least, because it diminishes coagulation factors and fibrinogen. Riboflavin has been studied most because it is a photoinactivator of endogenous origin and has few collateral effects. Amotosalen HCl is effective for platelets and is also used on plasma, but may cause changes both to plasma and to platelets, although these are not significant for hemostasis. S-303 FRALE may lead to neoantigens in erythrocytes and is less indicated for red-cell treatment; in such cases, PEN 110 is recommended. Thus, none of the methods for pathogen reduction is effective for all classes of agents and for all blood components, but despite the high cost, these photoinactivators may diminish the risk of blood-transmitted diseases.

  2. Endothelial microparticles (EMP for the assessment of endothelial function: an in vitro and in vivo study on possible interference of plasma lipids.

    Directory of Open Access Journals (Sweden)

    Sabrina H van Ierssel

    Full Text Available BACKGROUND: Circulating endothelial microparticles (EMP reflect the condition of the endothelium and are of increasing interest in cardiovascular and inflammatory diseases. Recently, increased numbers of EMP following oral fat intake, possibly due to acute endothelial injury, have been reported. On the other hand, the direct interference of lipids with the detection of EMP has been suggested. This study aimed to investigate the effect of lipid-rich solutions, commonly administered in clinical practice, on the detection, both in vitro and in vivo, of EMP. METHODS: For the in vitro assessment, several lipid-rich solutions were added to whole blood of healthy subjects (n = 8 and patients with coronary heart disease (n = 5. EMP (CD31+/CD42b- were detected in platelet poor plasma by flow cytometry. For the in vivo study, healthy volunteers were evaluated on 3 different study-days: baseline evaluation, following lipid infusion and after a NaCl infusion. EMP quantification, lipid measurements and peripheral arterial tonometry were performed on each day. RESULTS: Both in vitro addition and in vivo administration of lipids significantly decreased EMP (from 198.6 to 53.0 and from 272.6 to 90.6/µl PPP, respectively, p = 0.001 and p = 0.012. The EMP number correlated inversely with the concentration of triglycerides, both in vitro and in vivo (r = -0.707 and -0.589, p<0.001 and p = 0.021, respectively. The validity of EMP as a marker of endothelial function is supported by their inverse relationship with the reactive hyperemia index (r = -0.758, p = 0.011. This inverse relation was confounded by the intravenous administration of lipids. CONCLUSION: The confounding effect of high circulating levels of lipids, commonly found in patients that receive intravenous lipid-based solutions, should be taken into account when flow cytometry is used to quantify EMP.

  3. In vitro studies of PBT Nonwoven Fabrics adsorbent for the removal of low density lipoprotein from hyperlipemia plasma

    Science.gov (United States)

    Cao, Ye; Wang, Hong; Yang, Chao; Zhong, Rui; Lei, Yu; Sun, Kang; Liu, Jiaxin

    2011-06-01

    Polyanion ligands such as acrylic acid (AA) and heparin were grafted on PBT Nonwoven Fabrics (PBTNF) to study their effect on the adsorption of low density lipoprotein (LDL). These modified PBTNFs were characterized by Horizontal Attenuated Total Reflectance Fourier Transform Infrared spectroscopy and X-ray Photoelectron spectroscopy. The blood compatibilities of the modified PBTNFs were examined using in vitro hemolysis rate (HR), platelet adhesion, total protein (TP) and activated partial thromboplastin time. The results showed that direct immobilized heparin could improve PBTNF-PAA's blood compatibility and decrease the adsorption capability of useful high density lipoprotein, but would possess so low bioactivity that could not further improve the absorption of LDL and TC. Since the PBTNF-PAA55-Heparin adsorbent had quite good adsorption selectivity for these proteins, it can be an excellent candidate for depletion of LDL with good blood compatibility.

  4. In vitro studies of PBT Nonwoven Fabrics adsorbent for the removal of low density lipoprotein from hyperlipemia plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cao Ye; Wang Hong [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610052 (China); Yang Chao [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhong Rui [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610052 (China); Lei Yu [Chengdu Blood Center, Chengdu 610041 (China); Sun Kang [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu Jiaxin, E-mail: jxliu8122@vip.sina.com [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610052 (China)

    2011-06-15

    Polyanion ligands such as acrylic acid (AA) and heparin were grafted on PBT Nonwoven Fabrics (PBTNF) to study their effect on the adsorption of low density lipoprotein (LDL). These modified PBTNFs were characterized by Horizontal Attenuated Total Reflectance Fourier Transform Infrared spectroscopy and X-ray Photoelectron spectroscopy. The blood compatibilities of the modified PBTNFs were examined using in vitro hemolysis rate (HR), platelet adhesion, total protein (TP) and activated partial thromboplastin time. The results showed that direct immobilized heparin could improve PBTNF-PAA's blood compatibility and decrease the adsorption capability of useful high density lipoprotein, but would possess so low bioactivity that could not further improve the absorption of LDL and TC. Since the PBTNF-PAA55-Heparin adsorbent had quite good adsorption selectivity for these proteins, it can be an excellent candidate for depletion of LDL with good blood compatibility.

  5. The selective effect of plasma activated medium in an in vitro co-culture of liver cancer and normal cells

    Science.gov (United States)

    Duan, J.; Lu, X.; He, G.

    2017-01-01

    In this work, a co-culture system with liver cancer cell line HepG2 and normal cell line L02 is used to investigate the selective effect on cancer and normal cells by plasma activated medium (PAM), which is closer to the real environment where cancer cells develop. Besides, the co-culture system is a better model to study the selective effect than the widely used separate culture systems, where the cancer cell line and normal cell line are cultured independently. By using the co-culture system, it is found that there is an optimum dose of PAM to induce significant cancer cell apoptosis while keeping minimum damage to normal cells.

  6. Phenylbutazone radicals inactivate creatine kinase.

    Science.gov (United States)

    Miura, T; Muraoka, S; Fujimoto, Y

    2001-02-01

    Creatine kinase (CK) was used as a marker molecule to examine the side effect of damage to tissues by phenylbutazone (PB), an effective drug to treat rheumatic and arthritic diseases, with horseradish peroxidase and hydrogen peroxide (HRP-H(2)O2). PB inactivated CK during its interaction with HRP-H(2) O(2), and inactivated CK in rat heart homogenate. PB carbon-centered radicals were formed during the interaction of PB with HRP-H(2)O2. The CK efficiently reduced electron spin resonance signals of the PB carbon-centered radicals. The spin trap agent 2-methyl-2-nitrosopropane strongly prevented CK inactivation. These results show that CK was inactivated through interaction with PB carbon-centered radicals. Sulfhydryl groups and tryptophan residues in CK were lost during the interaction of PB with HRP-H(2)O2, suggesting that cysteine and tryptophan residues are oxidized by PB carbon-centered radicals. Other enzymes, including alcohol dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, but not lactate dehydrogenase, were also inactivated. Sulfhydryl enzymes seem to be sensitive to attack by PB carbon-centered radicals. Inhibition of SH enzymes may explain some of the deleterious effects induced by PB.

  7. Characteristics and in vitro response of thin hydroxyapatite–titania films produced by plasma electrolytic oxidation of Ti alloys in electrolytes with particle additions

    Science.gov (United States)

    Yeung, W. K.; Sukhorukova, I. V.; Shtansky, D. V.; Levashov, E. A.; Zhitnyak, I. Y.; Gloushankova, N. A.; Kiryukhantsev-Korneev, P. V.; Petrzhik, M. I.; Matthews, A.

    2016-01-01

    The enhancement of the biological properties of Ti by surface doping with hydroxyapatite (HA) is of great significance, especially for orthodontic applications. This study addressed the effects of HA particle size in the electrolyte suspension on the characteristics and biological properties of thin titania-based coatings produced on Ti–6Al–4V alloy by plasma electrolytic oxidation (PEO). Detailed morphological investigation of the coatings formed by a single-stage PEO process with two-step control of the electrical parameters was performed using the Minkowski functionals approach. The surface chemistry was studied by glow discharge optical emission spectroscopy and Fourier transform infrared spectroscopy, whereas mechanical properties were evaluated using scratch tests. The biological assessment included in vitro evaluation of the coating bioactivity in simulated body fluid (SBF) as well as studies of spreading, proliferation and osteoblastic differentiation of MC3T3-E1 cells. The results demonstrated that both HA micro- and nanoparticles were successfully incorporated in the coatings but had different effects on their surface morphology and elemental distributions. The micro-particles formed an irregular surface morphology featuring interpenetrated networks of fine pores and coating material, whereas the nanoparticles penetrated deeper into the coating matrix which retained major morphological features of the porous TiO2 coating. All coatings suffered cohesive failure in scratch tests, but no adhesive failure was observed; moreover doping with HA increased the coating scratch resistance. In vitro tests in SBF revealed enhanced bioactivity of both HA-doped PEO coatings; furthermore, the cell proliferation/morphometric tests showed their good biocompatibility. Fluorescence microscopy revealed a well-organised actin cytoskeleton and focal adhesions in MC3T3-E1 cells cultivated on these substrates. The cell alkaline phosphatase activity in the presence of

  8. Differential effect of platelet-rich plasma and fetal calf serum on bone marrow-derived human mesenchymal stromal cells expanded in vitro.

    Science.gov (United States)

    Goedecke, Anja; Wobus, Manja; Krech, Mathias; Münch, Nadine; Richter, Katja; Hölig, Kristina; Bornhauser, Martin

    2011-08-01

    Mesenchymal stromal cells (MSCs) derived from various sources have great potential for use in cell-based therapies. Since the proportion of primary MSCs contained in bone marrow or adipose tissue is low, plastic adherence and in vitro expansion are necessary to expand MSCs prior to clinical application. Human platelet-rich plasma has been introduced as an alternative serum source but functional differences have so far not been described. Here we cultured MSCs derived from human bone marrow in medium supplemented with either 10% fetal calf serum (FCS) or 5% and 10% platelet-rich plasma (PRP) until the first or second passage. Parameters under investigation were cell yield, clonogenicity, phenotype as well as migratory and differentiation potential. In addition, the secretion of SDF-1α and the induced migration of CD34(+) haematopoietic stem cells (HSCs) were investigated with regard to the different serum source. The use of PRP resulted in a significantly higher expansion rate and yield at passages 0 and 1. In addition, the level of secreted SDF-1α was significantly increased in the supernatant of MSCs cultured with FCS instead of human PRP. Consistent with this, the migration capacity of MSCs cultured with 10% FCS as well as their capability to induce the migration of CD34(+) haematopoietic progenitors in a transwell assay was higher. Our results demonstrate that human PRP can be seen as an alternative serum source to FCS for MSC cultivation. However, the requirements of the specific clinical application must be carefully considered before the respective serum source is selected. Copyright © 2010 John Wiley & Sons, Ltd.

  9. Influence of biflorin on the labelling of red blood cells, plasma protein, cell protein, and lymphocytes with technetium-99m: in vitro study

    Directory of Open Access Journals (Sweden)

    Thiago M. Aquino

    Full Text Available In this paper we report the results of an in vitro study involving the influence of biflorin (an o-quinone isolated from Capraria biflora L. that has potent antimicrobial activity on the Tc-99m labeling of red blood cells, plasma protein, cells protein, and lymphocytes. Blood was withdrawn from Wistar rats and incubated with various concentrations of biflorin, and solutions of stannous chloride and Tc-99m were added. Plasma (P and red blood cells (RBC were isolated, precipitated, and centrifuged, and soluble (SF and insoluble (IF fractions were isolated. The results show that the highest concentration (100% of biflorin is able to reduce the uptake of Tc-99m (%ATI on RBC and the fixation on IF-P. To study the influence of biflorin on 99mTc lymphocyte labeling, human blood was submitted to a technique with Ficoll-Hypac and centrifuged, and white cells were isolated. Lymphocytes (2.5 mL; 1.0 x 10(6 cells/mL were obtained and a 0.2 mL solution was incubated with biflorin (0.1 mL. Solutions of stannous chloride and 99mTc were added. Lymphocytes were separated and the %ATI bound in these cells was evaluated. A reduction in %ATI (from 97.85 ± 0.99 to 88.86 ± 5 was observed for RBC and for IF-P (73.24 ± 5.51 to 20.72 ± 6.95. In this case the results showed no decrease in %ATI for the lymphocytes with biflorin.

  10. Comparison of green pit viper and Agkistrodon halys antivenom in inhibition of coagulopathy due to Trimeresurus albolabris venom: an in-vitro study using human plasma.

    Science.gov (United States)

    Lam, S K; Yip, S F; Crow, P; Fung, H T; Cheng, J Mh; Tan, K S; Wong, O F; Yeung, D Yt; Wong, Y K; Poon, K M; Ades, G

    2017-02-01

    There are two antivenoms that may be administered in Hong Kong following a bite by Trimeresurus albolabris: the green pit viper antivenom from the Thai Red Cross Society in Thailand and the Agkistrodon halys antivenom from the Shanghai Institute of Biological Products in China. Both are recommended by the Central Coordinating Committee of Accident and Emergency Services of the Hospital Authority for treating patients with a bite by Trimeresurus albolabris. The choice of which antivenom to use is based on physician preference. This study aimed to compare the relative efficacy of the two antivenoms. This in-vitro experimental study was carried out by a wildlife conservation organisation and a regional hospital in Hong Kong. Human plasma from 40 adult health care worker volunteers was collected. The Trimeresurus albolabris venom was added to human plasma and the mixture was assayed after incubation with each antivenom (green pit viper and Agkistrodon halys) using saline as a control. Fibrinogen level and clotting time in both antivenom groups were studied. The mean fibrinogen level was elevated from 0 g/L to 2.86 g/L and 1.11 g/L after the addition of green pit viper antivenom and Agkistrodon halys antivenom, respectively. When mean clotting time was measured, the value was 6.70 minutes in the control, prolonged to more than 360 minutes by green pit viper antivenom and to 19.06 minutes by Agkistrodon halys antivenom. Green pit viper antivenom was superior to Agkistrodon halys antivenom in neutralisation of the thrombin-like and hypofibrinogenaemic activities of Trimeresurus albolabris venom.

  11. An in vitro evaluation of novel NHA/zircon plasma coating on 316L stainless steel dental implant

    Directory of Open Access Journals (Sweden)

    Ebrahim Karamian

    2014-04-01

    Full Text Available The surface characteristics of an implant that influence the speed and strength of osseointegration include crystal structure and bioactivity. The aim of this study was to evaluate the bioactivity of a novel natural hydroxyapatite/zircon (NHA/zircon nanobiocomposite coating on 316L stainless steel (SS dental implants soaking in simulated body fluid. A novel NHA/zircon nanobiocomposite was fabricated with 0 (control, 5, 10, and 15 wt% of zircon in NHA using ball mill for 1 h. The composite mixture was coated on SS implants using a plasma spray method. Scanning electron microscopy (SEM was used to evaluate surface morphology, and X-ray diffraction (XRD was used to analyze phase composition and crystallinity (Xc. Further, calcium ion release was measured to evaluate the coated nanobiocomposite samples. The prepared NHA/zircon coating had a nanoscale morphological structure with a mean crystallite size of 30–40 nm in diameter and a bone-like composition, which is similar to that of the biological apatite of a bone. For the prepared NHA powder, high bioactivity was observed owing to the formation of apatite crystals on its surface. Both minimum crystallinity (Xc=41.1% and maximum bioactivity occurred in the sample containing 10 wt% of zircon because of minimum Xc and maximum biodegradation of the coating sample.

  12. Effects of argon laser on in vitro aggregation of platelets in platelet rich plasma and whole blood

    Energy Technology Data Exchange (ETDEWEB)

    Doerger, P.T.; Glueck, H.I.; McGill, M.

    1988-06-01

    The effects of an Argon laser on platelet aggregation were studied, since platelets may be exposed to laser energy when used intravascularly. Various preparations of platelets in platelet rich plasma (PRP) and whole blood, with or without aspirin, were tested with the aggregating agents ADP, collagen, thrombin, and epinephrine. Simultaneous release of ATP was also measured in PRP. At relatively low levels of irradiation, platelet aggregation was potentiated. Enhancement was evidenced by an increase in percent aggregation, earlier onset of the reaction, and reduction in the amount of aggregating agent required. In PRP, the mechanism of laser potentiation appeared to be the release of endogenous ATP from platelets. At relatively high levels of irradiation, platelets were destroyed and aggregation abolished. In whole blood, the mechanism was somewhat more complicated since release of ATP occurred from RBCs as well as platelets. Spontaneous aggregation following laser treatment occurred in isolated instances in PRP and in every trial in whole blood preparations. Aspirin ingestion inhibited the laser's effects in PRP but not in whole blood. These results may have important clinical implications for laser angioplasty, and the potentiated aggregation response may prove useful in laboratory studies of platelet function.

  13. Molecular mechanism of plasma sterilization in solution with the reduced pH method: importance of permeation of HOO radicals into the cell membrane

    Science.gov (United States)

    Takai, Eisuke; Ikawa, Satoshi; Kitano, Katsuhisa; Kuwabara, Junpei; Shiraki, Kentaro

    2013-07-01

    Sterilization of certain infected areas of the human body surface is necessary for dental and surgical therapies. Because the blood is filled with body fluid, sterilization in solution is essential. In vitro solution sterilization has been successively carried out using a combination of low-temperature atmospheric-pressure plasma and the reduced pH method, where the solution is sufficiently acidic. Here, we show the molecular mechanism of such plasma sterilization in solution based on microbiology. Three kinds of bacteria were inactivated by plasma treatment under various pH conditions. The theoretical and experimental models revealed that the sterilization was characterized by the concentration of hydroperoxy radicals (HOO·), which were dependent on the pH value. Bacterial inactivation rates were proportional to the HOO· concentrations calculated by the theoretical model. To evaluate the penetration of radicals into the cell membrane, a bacterial model using dye-included micelles was used. Decolouration rates of the model were also in proportion with the calculated HOO· concentrations. These results indicate that the key species for plasma sterilization were hydroperoxy radicals. More importantly, the high permeation of hydroperoxy radicals into the cell membrane plays a key role for efficient bactericidal inactivation using the reduced pH method.

  14. Simultaneous characterisation of silver nanoparticles and determination of dissolved silver in chicken meat subjected to in vitro human gastrointestinal digestion using single particle inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Ramos, K; Ramos, L; Gómez-Gómez, M M

    2017-04-15

    In this study, a chicken meat containing AgNPs (candidate reference material Nanolyse 14) has been used as a model matrix to study the fate and behaviour of AgNPs upon oral ingestion following an in vitro model that included saliva, gastric and intestinal digestions. The behaviour of a 40nm AgNPs standard solution during the three digestion steps was also evaluated. Sample preparation conditions were optimised to prevent AgNPs oxidation and/or aggregation and to ensure the representativeness of the reported results. Total silver released from the test sample and the evaluated AgNP standard was determined by inductively coupled plasma mass spectrometry (ICPMS). The presence of both AgNPs and dissolved silver in the extracts was confirmed by single particle (SP)-ICPMS analysis. AgNPs were sized and the particle number concentration determined in the three digestion juices. Experimental results demonstrated differentiated behaviours for AgNP from the standard solution and the meat sample highlighting the relevance of using physiological conditions for accurate risk assessment. In the most realistic scenario assayed (i.e., spiked chicken meat analysis), only 13% of the AgNPs present in the reference material would reach the intestine wall. Meanwhile, other bioaccessible dissolved forms of silver would account for as much as 44% of the silver initially spiked to the meat paste. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The Phytocomplex from Fucus vesiculosus and Ascophyllum nodosum Controls Postprandial Plasma Glucose Levels: An In Vitro and In Vivo Study in a Mouse Model of NASH.

    Science.gov (United States)

    Gabbia, Daniela; Dall'Acqua, Stefano; Di Gangi, Iole Maria; Bogialli, Sara; Caputi, Valentina; Albertoni, Laura; Marsilio, Ilaria; Paccagnella, Nicola; Carrara, Maria; Giron, Maria Cecilia; De Martin, Sara

    2017-02-15

    Edible seaweeds have been consumed by Asian coastal communities since ancient times. Fucus vesiculosus and Ascophyllum nodosum extracts have been traditionally used for the treatment of obesity and several gastrointestinal diseases. We evaluated the ability of extracts obtained from these algae to inhibit the digestive enzymes α-amylase and α-glucosidase in vitro, and control postprandial plasma glucose levels in a mouse model of non-alcoholic steatohepatitis (NASH); a liver disease often preceding the development of Type 2 diabetes (T2DM). This model was obtained by the administration of a high-fat diet. Our results demonstrate that these algae only delayed and reduced the peak of blood glucose (p < 0.05) in mice fed with normal diet, without changing the area under the blood glucose curve (AUC). In the model of NASH, the phytocomplex was able to reduce both the postprandial glycaemic peak, and the AUC. The administration of the extract in a diet particularly rich in fat is associated with a delay in carbohydrate digestion, but also with a decrease in its assimilation. In conclusion, our results indicate that this algal extract may be useful in the control of carbohydrate digestion and absorption. This effect may be therapeutically exploited to prevent the transition of NASH to T2DM.

  16. Arsenic Species in Edible Seaweeds Using In Vitro Biomimetic Digestion Determined by High-Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Yan-Fang Zhao

    2014-01-01

    Full Text Available Arsenite [As (III], arsenate [As (V], methylarsonate (MMA, and dimethylarsinate (DMA in five edible seaweeds (the brown algae Laminaria japonica, red algae Porphyra yezoensis, brown algae Undaria pinnatifida, brown algae Hizikia fusiformis, and green algae Enteromorpha prolifera were analyzed using in vitro digestion method determined by high-performance liquid chromatography inductively coupled plasma mass spectrometry. The results showed that DMA was found in the water extracts of all samples; As (III were detected in L. japonica and U. pinnatifida and about 23.0 and 0.15 mg/kg of As (V were found in H. fusiformis and E. prolifera respectively. However, after the gastrointestinal digestion, As (V was not detected in any of the five seaweeds. About 0.19 and 1.47 mg/kg of As (III was detected in the gastric extracts of L. japonica and H. fusiformis, respectively, and about 0.31 and 0.10 mg/kg of As (III were extracted from the intestinal extracts of Porphyra yezoensis and U. pinnatifida, respectively. The present results successfully reveal the differences of As species and levels in the water and biomimetic extracts of five edible seaweeds. The risk assessment of the inorganic arsenic in the five edible seaweeds based on present data showed almost no hazards to human health.

  17. The Phytocomplex from Fucus vesiculosus and Ascophyllum nodosum Controls Postprandial Plasma Glucose Levels: An In Vitro and In Vivo Study in a Mouse Model of NASH

    Directory of Open Access Journals (Sweden)

    Daniela Gabbia

    2017-02-01

    Full Text Available Edible seaweeds have been consumed by Asian coastal communities since ancient times. Fucus vesiculosus and Ascophyllum nodosum extracts have been traditionally used for the treatment of obesity and several gastrointestinal diseases. We evaluated the ability of extracts obtained from these algae to inhibit the digestive enzymes α-amylase and α-glucosidase in vitro, and control postprandial plasma glucose levels in a mouse model of non-alcoholic steatohepatitis (NASH; a liver disease often preceding the development of Type 2 diabetes (T2DM. This model was obtained by the administration of a high-fat diet. Our results demonstrate that these algae only delayed and reduced the peak of blood glucose (p < 0.05 in mice fed with normal diet, without changing the area under the blood glucose curve (AUC. In the model of NASH, the phytocomplex was able to reduce both the postprandial glycaemic peak, and the AUC. The administration of the extract in a diet particularly rich in fat is associated with a delay in carbohydrate digestion, but also with a decrease in its assimilation. In conclusion, our results indicate that this algal extract may be useful in the control of carbohydrate digestion and absorption. This effect may be therapeutically exploited to prevent the transition of NASH to T2DM.

  18. Harmful Effects of Leukocyte-Rich Platelet-Rich Plasma on Rabbit Tendon Stem Cells In Vitro.

    Science.gov (United States)

    Zhang, Lei; Chen, Shuo; Chang, Peng; Bao, Nirong; Yang, Chao; Ti, Yufan; Zhou, Liwu; Zhao, Jianning

    2016-08-01

    Platelet-rich plasma (PRP) is now widely used as a promising treatment for patients with tendinopathy. However, the efficacy of PRP treatment for tendinopathy is controversial mainly because of inconsistent results from human clinical trials and particularly because the concentration and effect of leukocytes in PRP remain largely unknown. Leukocyte-rich PRP (L-PRP) inhibits growth factor release, decreases proliferation, and induces nontenocyte differentiation of tendon stem cells (TSCs); increases catabolic cytokine concentrations; and causes inflammation and apoptosis. Thus, L-PRP has a detrimental effect on tendon stem/progenitor cells, which impairs injured tendon healing. Controlled laboratory study. Pure PRP (P-PRP) and L-PRP were prepared from the same individual rabbit blood, and platelet numbers in each PRP product were adjusted to reach the same level. The leukocyte level in L-PRP was 4 and 8 times higher than those in whole blood and P-PRP, respectively. The growth factors in both P-PRP and L-PRP were measured by enzyme-linked immunosorbent assay kits. The morphology, stemness, proliferation, and differentiation of TSCs grown in L-PRP and P-PRP were examined by microscopy, immunocytochemistry, population doubling time, quantitative real-time polymerase chain reaction, and histological analysis. L-PRP produced lower levels of growth factors, such as vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), transforming growth factor (TGF)-β1, and platelet-derived growth factor (PDGF), than did P-PRP. TSC proliferation was significantly decreased in L-PRP in a concentration-dependent manner. Furthermore, TSCs cultured in P-PRP produced more collagen and formed tendon-like tissue; however, TSCs grown in L-PRP differentiated into nontenocytes and produced more inflammatory factors such as membrane-associated prostaglandin synthase (mPGES) and interleukin (IL)-1β. Moreover, L-PRP was associated with increased apoptosis. L-PRP has harmful

  19. Inactivation of 10(15) chimpanzee-infectious doses of hepatitis B virus during preparation of a heat-inactivated hepatitis B vaccine

    NARCIS (Netherlands)

    Lelie, P. N.; Reesink, H. W.; Niessen, J.; Brotman, B.; Prince, A. M.

    1987-01-01

    The safety of a plasma-derived hepatitis-B vaccine inactivated by two heating steps (90 sec at 103 degrees C followed by 10 hr pasteurization at 65 degrees C) was validated in chimpanzees; 10(3) chimpanzee-infectious doses (CID50) of hepatitis-B virus (HBV), subjected to the purification steps

  20. Influenza Vaccine, Inactivated or Recombinant

    Science.gov (United States)

    ... die from flu, and many more are hospitalized.Flu vaccine can:keep you from getting flu, make flu ... What is inactivated or recombinant influenza vaccine?A dose of flu vaccine is recommended every flu season. Children 6 months through 8 years of age may need two ...

  1. Cytolytic T lymphocyte responses to metabolically inactivated stimulator cells. I. Metabolic inactivation impairs both CD and LD antigen signals

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, A.; Boyle, W.

    1982-03-01

    The effects of metabolic inactivation of spleen cells on antigen presentation to precursors of alloreactive cytolytic T lymphocytes (T/sub c/) were examined. By serological methods, populations inactivated by ultraviolet irradiation, glutaraldehyde fixation or plasma membrane isolation were found to retain normal levels of H-2K/D and Ia antigens. However, comparison of the antigen doses required to stimulate secondary T/sub c/ responses in mixed leukocyte culture showed that the inactivated preparations were approximately 10-fold less immunogenic than X-irradiated spleen cells. Their total inability to stimulate primary cytolytic responses pointed to at least a 100-fold impairment of immunogenicity for unprimed T/sub c/ precursors in the case of uv-irradiated and glutaraldehyde-treated stimulator cells, and at least a 10-fold impairment for membrane fragments. Experiments showing that the capacity of cell monolayers to absorb precursor T/sub c/ from unprimed spleen populations was reduced following uv-irradiation or glutaraldehyde treatment provided direct evidence that this loss of immunogenicity was due in part to suboptimal antigen presentation to precursor T/sub c/. It is concluded that, in addition to the traditional view that these treatments damage the ''LD'' signal to helper T lymphocytes, metabolic inactivation also impairs recognition of ''CD'' determinants by precursor T/sub c/.

  2. Inhibition of bone resorption by selective inactivators of cysteine proteinases.

    Science.gov (United States)

    Hill, P A; Buttle, D J; Jones, S J; Boyde, A; Murata, M; Reynolds, J J; Meikle, M C

    1994-09-01

    Inactivators of cysteine proteinases (CPs) were tested as inhibitors of bone resorption in vitro and in vivo. The following four CP inactivators were tested: Ep475, a compound with low membrane permeability which inhibits cathepsins B, L, S, H, and calpain; Ep453, the membrane-permeant prodrug of Ep475; CA074, a compound with low membrane permeability which selectively inactivates cathepsin B; and CA074Me, the membrane-permeant prodrug of CA074. The test systems consisted of 1) monitoring the release of radioisotope from prelabelled mouse calvarial explants and 2) assessing the extent of bone resorption in an isolated osteoclast assay using confocal laser microscopy. Ep453, Ep475, and CA074Me inhibited both stimulated and basal bone resorption in vitro while CA074 was without effect; the inhibition was reversible and dose dependent. None of the inhibitors affected protein synthesis, DNA synthesis, the PTH-enhanced secretion of beta-glucuronidase, and N-acetyl-beta-glucosaminidase, or the spontaneous release of lactate dehydrogenase. Ep453, Ep475, and CA074Me dose-dependently inhibited the resorptive activity of isolated rat osteoclasts cultured on bone slices with a maximal effect at 50 microM. The number of resorption pits and their mean volume was reduced, whilst the mean surface area remained unaffected. Again, CA074 was without effect. Ep453, Ep475, and CA074Me, but not CA074, when administered subcutaneously at a dose of 60 micrograms/g body weight inhibited bone resorption in vivo as measured by an in vivo/in vitro assay, by about 20%. This study demonstrates that cathepsins B, L, and/or S are involved in bone resorption in vitro and in vivo. Whilst cathepsin L and/or S act extracellularly, and possibly intracellularly, cathepsin B mediates its effects intracellularly perhaps through the activation of other proteinases involved in subosteoclastic collagen degradation.

  3. Plasma Therapy: An Overview

    Directory of Open Access Journals (Sweden)

    Rajkumar Diwan

    2011-01-01

    Full Text Available Definition: Plasma, the fourth state of matter, is a collection of charged particles (electrons, ions, neutral atoms. Recent demonstration of plasma technology in treatment of living cells, tissue and organs are creating a new field at the intersection of plasma science and technology with biology and medicine known as plasma medicine. Plasma medicine is one of the newest fields of modem applied plasma chemistry. It appeared several years ago and comprises studies concerning the direct action of low-temperature, one atmosphere air plasma (cold plasma/nonthermal plasmalnonequilibrium on body tissues for various noninvasive therapeutic treatments or diagnostics purpose. The study of plasma holds promise for a myriad of applications ranging from lasers and electronics, hazardous decontamination, sterilization and disinfection of foods, soil, water, instruments, to medical uses in wound healing and treating certain types of tumors and cancers. Plasma represents a new state-of-the-art sterilization and disinfection treatment for certain oral and environmental pathogens, heat-sensitive materials, hard and soft surfaces, and may assist health care facilities in the management of various health concerns. The role that low temperature atmospheric pressure plasma (LTAPP could play in the inactivation of pathogenic microorganisms might prove to be a new, faster, more economical alternative.

  4. Inactivation of rabies virus by hydrogen peroxide.

    Science.gov (United States)

    Abd-Elghaffar, Asmaa A; Ali, Amal E; Boseila, Abeer A; Amin, Magdy A

    2016-02-03

    Development of safe and protective vaccines against infectious pathogens remains a challenge. Inactivation of rabies virus is a critical step in the production of vaccines and other research reagents. Beta-propiolactone (βPL); the currently used inactivating agent for rabies virus is expensive and proved to be carcinogenic in animals. This study aimed to investigate the ability of hydrogen peroxide (H2O2) to irreversibly inactivate rabies virus without affecting its antigenicity and immunogenicity in pursuit of finding safe, effective and inexpensive alternative inactivating agents. H2O2 3% rapidly inactivated a Vero cell adapted fixed rabies virus strain designated as FRV/K within 2h of exposure without affecting its antigenicity or immunogenicity. No residual infectious virus was detected and the H2O2-inactivated vaccine proved to be safe and effective when compared with the same virus harvest inactivated with the classical inactivating agent βPL. Mice immunized with H2O2-inactivated rabies virus produced sufficient level of antibodies and were protected when challenged with lethal CVS virus. These findings reinforce the idea that H2O2 can replace βPL as inactivating agent for rabies virus to reduce time and cost of inactivation process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Angiogenic properties of sustained release platelet-rich plasma: characterization in-vitro and in the ischemic hind limb of the mouse.

    Science.gov (United States)

    Bir, Shyamal Chandra; Esaki, Jiro; Marui, Akira; Yamahara, Kenichi; Tsubota, Hideki; Ikeda, Tadashi; Sakata, Ryuzo

    2009-10-01

    While single growth factor has limitation to induce optimal neovascularization, platelet-rich plasma (PRP) is an autologous reserver of various growth factors. However, little is known about the mechanism of PRP-related neovascularization.The objective of this investigation was to characterize the angiogenic and growth factor content of PRP and to determine, in vitro, its effect on endothelial cell proliferation. Additionally, this experiment sought to determine the effectiveness of different compositions of PRP (solution versus sustained release) on perfusion and neovascularization in a murine model of hind limb ischemia. Different growth factors were measured by enzyme-linked immunosorbent assay (ELISA). In vivo study, we used gelatin hydrogel as a sustained release carrier for growth factors in PRP. We induced hind limb ischemia by excising right femoral artery in wild type C57BL6 mice. After surgery, mice were randomly assigned to four experimental groups; control (C), 100 muL of sustained release form of platelet-poor plasma (PPP), 100 muL of solution form of PRP (PRP-sol), 100 muL of sustained release form of PRP (PRP-sr); each formulation was administered via an intramuscular injection to the ischemic hind limb. Endpoint evaluations were blood perfusion by laser Doppler perfusion image, vascular density by anti Von Willebrand factor (vWF), and mature vessel density by anti smooth muscle actin (SMA) antibody. Green fluorescent protein (GFP+) transgenic mice were generated by transplantation of bone marrow derived mononuclear cells to wild type C57BL6 mice, and finally CD34+ cell in the ischemic site of transgenic mice was detected by staining with anti-CD34 antibody. In vitro study showed that PRP containing different growth factors induces endothelial cell proliferation and capillary tube formation. In vivo study demonstrated that sustained release of PRP increased perfusion of ischemic tissue as measured by laser Doppler perfusion imaging (LDPI) (57 +/- 12

  6. Rapid fabrication of dense 45S5 Bioglass®compacts through spark plasma sintering and evaluation of their in vitro biological properties.

    Science.gov (United States)

    Li, Zhong; Thompson, Brianna C; Hu, Huanlong; Khor, Khiam Aik

    2016-10-27

    It is challenging to obtain dense 45S5 Bioglass ® (45S5) with controlled crystallinity and satisfactory mechanical properties by conventional sintering processes due to its fast crystallization above the first glass transition temperature. Spark plasma sintering (SPS) has stood out in this respect by virtue of its capability to provide fast heating and densification rates. However, there have been insufficient investigations into the in vitro biological properties of 45S5 compacts obtained by SPS. In this study, we report the fabrication of fully densified 45S5 pellets in the temperature range of 500 °C-600 °C through a rapid SPS process (sintering for 3 min) as well as the assessment of the influence of sintering temperature and aqueous aging on the biological properties of sintered pellets with L929 and MG63 cells. The cell culture results showed that both extended ageing and a lower SPS temperature in the 500-600 °C range could generally lead to faster cell proliferation and higher cell viability. The former was possibly caused by the slower alkalization of the media during cell culture, and the latter may have resulted from the release of more Ca and Si ions. The pellet sintered at 550 °C without aqueous aging led to the highest ALP activity in MG63 cells, which may be attributed to the high interfacial pH at the pellet surface and the leaching of more Si ions. Therefore, dense 45S5 compacts with mild crystallinity consolidated by SPS at 550 °C is a promising candidate for orthopedic implants in loading bearing applications.

  7. Inactivation of allergens and toxins.

    Science.gov (United States)

    Morandini, Piero

    2010-11-30

    Plants are replete with thousands of proteins and small molecules, many of which are species-specific, poisonous or dangerous. Over time humans have learned to avoid dangerous plants or inactivate many toxic components in food plants, but there is still room for ameliorating food crops (and plants in general) in terms of their allergens and toxins content, especially in their edible parts. Inactivation at the genetic rather than physical or chemical level has many advantages and classical genetic approaches have resulted in significant reduction of toxin content. The capacity, offered by genetic engineering, of turning off (inactivating) specific genes has opened up the possibility of altering the plant content in a far more precise manner than previously available. Different levels of intervention (genes coding for toxins/allergens or for enzymes, transporters or regulators involved in their metabolism) are possible and there are several tools for inactivating genes, both direct (using chemical and physical mutagens, insertion of transposons and other genetic elements) and indirect (antisense RNA, RNA interference, microRNA, eventually leading to gene silencing). Each level/strategy has specific advantages and disadvantages (speed, costs, selectivity, stability, reversibility, frequency of desired genotype and regulatory regime). Paradigmatic examples from classical and transgenic approaches are discussed to emphasize the need to revise the present regulatory process. Reducing the content of natural toxins is a trade-off process: the lesser the content of natural toxins, the higher the susceptibility of a plant to pests and therefore the stronger the need to protect plants. As a consequence, more specific pesticides like Bt are needed to substitute for general pesticides. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Inactivating mutations in NPC1L1 and protection from coronary heart disease

    NARCIS (Netherlands)

    Stitziel, Nathan O.; Won, Hong-Hee; Morrison, Alanna C.; Peloso, Gina M.; Do, Ron; Lange, Leslie A.; Fontanillas, Pierre; Gupta, Namrata; Duga, Stefano; Goel, Anuj; Farrall, Martin; Saleheen, Danish; Ferrario, Paola; König, Inke; Asselta, Rosanna; Merlini, Piera A.; Marziliano, Nicola; Notarangelo, Maria Francesca; Schick, Ursula; Auer, Paul; Assimes, Themistocles L.; Reilly, Muredach; Wilensky, Robert; Rader, Daniel J.; Hovingh, G. Kees; Meitinger, Thomas; Kessler, Thorsten; Kastrati, Adnan; Laugwitz, Karl-Ludwig; Siscovick, David; Rotter, Jerome I.; Hazen, Stanley L.; Tracy, Russell; Cresci, Sharon; Spertus, John; Jackson, Rebecca; Schwartz, Stephen M.; Natarajan, Pradeep; Crosby, Jacy; Muzny, Donna; Ballantyne, Christie; Rich, Stephen S.; O'Donnell, Christopher J.; Abecasis, Goncalo; Sunyaev, Shamil; Nickerson, Deborah A.; Buring, Julie E.; Ridker, Paul M.; Chasman, Daniel I.; Austin, Erin; Ye, Zi; Kullo, Iftikhar J.; Weeke, Peter E.; Shaffer, Christian M.; Bastarache, Lisa A.; Denny, Joshua C.; Roden, Dan M.; Palmer, Colin; Deloukas, Panos; Lin, Dan-Yu; Tang, Zheng-zheng; Erdmann, Jeanette; Schunkert, Heribert; Danesh, John; Marrugat, Jaume; Elosua, Roberto; Ardissino, Diego; McPherson, Ruth; Watkins, Hugh; Reiner, Alex P.; Wilson, James G.; Altshuler, David; Gibbs, Richard A.; Lander, Eric S.; Boerwinkle, Eric; Gabriel, Stacey; Kathiresan, Sekar

    2014-01-01

    Ezetimibe lowers plasma levels of low-density lipoprotein (LDL) cholesterol by inhibiting the activity of the Niemann-Pick C1-like 1 (NPC1L1) protein. However, whether such inhibition reduces the risk of coronary heart disease is not known. Human mutations that inactivate a gene encoding a drug

  9. Experimental Study on Inactivation of Bacterial Endotoxin by Using Dielectric Barrier Discharge

    Science.gov (United States)

    Shi, Xingmin; Li, Yaxi; Zhang, Guanjun; Ma, Yue; Shao, Xianjun

    2011-12-01

    The low-temperature plasma (LTP) generated by dielectric barrier discharge (DBD) was used to sterilize the E.coli endotoxin, which is usually difficult to kill by traditional methods. Three different concentrations of bacterial endotoxin (1 EU/mL, 0.5 EU/mL and 0.25 EU/mL) were treated by LTP for different time (20 s, 40 s and 60 s). Tachypleus amebocyte lysate (TAL) method was employed to detect the concentration variation of bacterial endotoxin before and after the plasma treatment, and endotoxic shock mice model was used to evaluate the inactivation effects of LTP on endotoxin for further study. Experimental results demonstrated that, DBD plasma can inactivate the bacterial endotoxin quickly and effectively, and when the LTP treatment time was increased, the concentrations of bacterial endotoxin decreased gradually (after 60 s plasma treatment, its inactivation effect was beyond the Chinese pharmacopoeia standard), and the average survival time of mice gradually extended. The possible inactivation mechanisms are proposed to be related to reactive oxygen species (ROSs).

  10. Sterilization by oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Adir Jose; Mansano, Ronaldo Domingues; Andreoli Pinto, Terezinha de Jesus; Ruas, Ronaldo; Silva Zambon, Luis da; Silva, Monica Valero da; Verdonck, Patrick Bernard

    2004-07-31

    The use of polymeric medical devices has stimulated the development of new sterilization methods. The traditional techniques rely on ethylene oxide, but there are many questions concerning the carcinogenic properties of the ethylene oxide residues adsorbed on the materials after processing. Another common technique is the gamma irradiation process, but it is costly, its safe operation requires an isolated site and it also affects the bulk properties of the polymers. The use of a gas plasma is an elegant alternative sterilization technique. The plasma promotes an efficient inactivation of the micro-organisms, minimises the damage to the materials and presents very little danger for personnel and the environment. Pure oxygen reactive ion etching type of plasmas were applied to inactivate a biologic indicator, the Bacillus stearothermophilus, to confirm the efficiency of this process. The sterilization processes took a short time, in a few minutes the mortality was complete. In situ analysis of the micro-organisms' inactivating time was possible using emission spectrophotometry. The increase in the intensity of the 777.5 nm oxygen line shows the end of the oxidation of the biologic materials. The results were also observed and corroborated by scanning electron microscopy.

  11. Experiences with semi-routine production of riboflavin and UV-B pathogen-inactivated platelet concentrates in three blood centres.

    Science.gov (United States)

    van der Meer, P F; Couture, C; Hervig, T; Kruit, G; Devine, D V; de Korte, D; Kerkhoffs, J-L

    2017-01-01

    For a clinical platelet (PLT) transfusion trial conducted in three countries, the production of PLT concentrates (PCs) that were pathogen inactivated with the Mirasol technology was set up and validated. While the Mirasol procedure is applied to an established PLT product, the PLT processing procedure still had to be modified to ensure a treated PC was of sufficient quality. Further, the effect of simulated transport conditions and the effect of ambient light on Mirasol-treated PCs was determined. Platelet concentrates in plasma were made from pooled buffy coats followed by Mirasol treatment. To mimic transport conditions, units were left unagitated for 6 h at room temperature. To mimic ambient light exposure, units were held unagitated for 4 h in direct fluorescent tube light. Measures had to be taken to allow 7-day storage of treated concentrates. In one site, PCs made from five buffy coats with >450 × 109 PLTs were removed from inventory. Another site went from five to four buffy coats per pool. Interruption of agitation for 6 h on day 3 did not induce meaningful changes in in vitro measures, even when stored up to 7 days. Exposure to ambient light for 4 h, either on day 3 or 6, had no effect on in vitro measures. The Mirasol pathogen inactivation process can be implemented in routine, but changes to current PLT processing methods might be needed. Transport conditions and 4-h-long ambient light exposure have no negative effect on the in vitro quality of Mirasol-treated PCs. © 2016 International Society of Blood Transfusion.

  12. Photosensitized inactivation of infectious blood-borne human parasites

    Science.gov (United States)

    Judy, Millard M.; Sogandares-Bernal, Franklin M.; Matthews, James Lester

    1995-05-01

    Blood-borne viruses and protozoan parasites that are infectious to humans pose risk world-wide of infection transmission through blood and blood product transfusion. Blood-borne infectious viruses include human immunodeficiency virus (HIV-I), which causes AIDS; hepatitis C virus, which can cause chronic hepatitis; and cytomegalovirus, which can be dangerous to immunocompromised patients, e.g., the newborn, transplant recipients, and AIDS patients. Infectious blood-borne protozoan parasites include Trypanosoma cruzi, which causes Chagas' disease, endemic throughout Central and South America; the Trypanosoma species causing African sleeping sickness endemic in Central Africa; and Plasmodium falciparum, which causes malignant and increasingly drug- resistant human malaria prevalent throughout the tropics. Some researchers have focused on using photosensitizers to inactivate HIV-I and other viruses in whole blood, packed red cells, and platelet concentrates without compromising blood product function. Our group previously has reported photosensitized in vitro inactivation of P. falciparum and the mouse malaria organism Plasmodium berghei in whole blood using hematoporphyrin derivative (HPD) and of T. cruzi using benzoporphyrin derivatives BPDMA and BPDDA, dihematoporphyrin ether (DHE), and hydroxyethylvinyldeuteroporphyrin (HEVD). These results suggest that continued investigation is warranted to evaluate the potential for photosensitized inactivation of blood-borne parasites in blood banking.

  13. Effects of atmospheric pressure plasma jet with floating electrode on murine melanoma and fibroblast cells

    Science.gov (United States)

    Xu, G.; Liu, J.; Yao, C.; Chen, S.; Lin, F.; Li, P.; Shi, X.; Zhang, Guan-Jun

    2017-08-01

    Atmospheric pressure cold plasma jets have been recently shown as a highly promising tool in certain cancer therapies. In this paper, an atmospheric pressure plasma jet (APPJ) with a one inner floating and two outer electrode configuration using helium gas for medical applications is developed. Subjected to a range of applied voltages with a frequency of 19.8 kHz at a fixed rate of gas flow (i.e., 3 l/min), electrical and optical characteristics of the APPJ are investigated. Compared with the device only with two outer electrodes, higher discharge current, longer jet, and more active species in the plasma plume at the same applied voltage together with the lower gas breakdown voltage can be achieved through embedding a floating inner electrode. Employing the APPJ with a floating electrode, the effects of identical plasma treatment time durations on murine melanoma cancer and normal fibroblast cells cultured in vitro are evaluated. The results of cell viability, cell apoptosis, and DNA damage detection show that the plasma can inactivate melanoma cells in a time-dependent manner from 10 s to 60 s compared with the control group (p melanoma cells at the same treatment time. The different basal reactive oxygen species level and antioxidant superoxide dismutase level of two kinds of cells may account for their different responses towards the identical plasma exposure.

  14. The Tissue-Engineered Tendon-Bone Interface: In Vitro and In Vivo Synergistic Effects of Adipose-Derived Stem Cells, Platelet-Rich Plasma, and Extracellular Matrix Hydrogel.

    Science.gov (United States)

    McGoldrick, Rory; Chattopadhyay, Arhana; Crowe, Christopher; Chiou, Grace; Hui, Kenneth; Farnebo, Simon; Davis, Christopher; Le Grand, Anais; Jacobs, Molly; Pham, Hung; Chang, James

    2017-12-01

    Suboptimal healing of the tendon-bone interface remains an unsolved problem. The authors hypothesized that (1) platelet-rich plasma and prolonged in vitro incubation will produce interface scaffolds with greater reseeding of viable adipose-derived stem cells; and (2) when implanted with extracellular matrix hydrogel, constructs will display superior in vivo strength repair and biocompatibility. Achilles-calcaneal composite tendon-bone interface scaffold grafts were harvested from 30 Wistar rats. After physicochemical decellularization and lyophilization, scaffolds were revitalized in rat plasma or 100% activated rat platelet-rich plasma and reseeded with viable adipose-derived stem cells. For part 2 of the study, 90 Sprague-Dawley rats underwent reconstruction with one of five decellularized, lyophilized scaffold revitalization/reseeding conditions: (1) phosphate-buffered saline; (2) lyophilized, 100% activated platelet-rich plasma; (3) platelet-rich plasma and extracellular matrix hydrogel; (4) platelet-rich plasma and 14-day reseeding with ASC-luc2-eGFP cells; and (5) plasma, reseeding, and hydrogel. In part 1, platelet-rich plasma-revitalized grafts demonstrated greater live viable adipose-derived stem cell loads at 3, 7, and 14 days and total adipose-derived stem cell loads at 7 and 14 days with visibly greater live surface cellularity, layering, migration, and penetration. In part 2, bioluminescence imaging confirmed cell viability to day 22 after implantation. Biomechanical strength testing demonstrated a significant increase in ultimate failure load for reseeded groups compared with all other groups at week 2, whereas only reseeded grafts with hydrogel remained significantly stronger at weeks 4 and 8. Histologic examination demonstrated most increased tendinous cellular invasion and fibrocartilage repopulation at 8 weeks in the reseeded group with hydrogel. Masson trichrome staining demonstrated persistence of the scaffold structure at week 8 and blinded

  15. Inactivation of multidrug resistant (MDR)- and extensively drug resistant (XDR)-Mycobacterium tuberculosis by photodynamic therapy.

    Science.gov (United States)

    Sung, Nackmoon; Back, Sunmi; Jung, Jinhee; Kim, Ki-Hong; Kim, Jong-Ki; Lee, Jae Ho; Ra, Yongjoon; Yang, Hee Chul; Lim, Cheong; Cho, Sukki; Kim, Kwhanmien; Jheon, Sanghoon

    2013-12-01

    We investigated the effects of photodynamic therapy (PDT) on anti-tuberculosis (TB) activity by measuring inactivation rates, expressed as D-value, of MDR- and XDR-Mycobacterium tuberculosis (M. tb) clinical strains in vitro. Approximately 10(6) colony forming unit per milliliter (CFU/ml) of the bacilli were irradiated with various doses of laser light after exposure to photosensitizers. Survival of M. tb was measured by enumerating CFU in 7H10 medium to measure D-values. No inactivation of M. tb was observed when exposed to photosensitizers (radachlorin or DH-I-180-3) only or laser light only (P>0.1). Treatment with a combination of photosentizer and laser inactivated M. tb although there was a significant difference between the types of photosensitizers applied (Pcurves for the clinical M. tb strains were obtained up to laser doses of 30 J/cm(2) but prolonged irradiation did not linearly inactivate M. tb, yielding sigmoid PDT inactivation curves. D-values of M. tb determined from the slope of linear regression lines in PDT were not significantly different and ranged from 10.50 to 12.13 J/cm(2) with 670 nm laser irradiation at 100 mW/cm(2) of the fluency rate, except for a drug-susceptible strain among the clinical strains tested. This suggests that PDT inactivated M. tb clinical strains regardless of drug resistance levels of the bacilli. Intermittent and repeated PDT allowed acceleration of the inactivation of the bacilli as a way to avoid the sigmoid inactivation curves. In conclusion, PDT could be alternative as a new option for treatment for MDR- and XDR-tuberculosis. Copyright © 2013. Published by Elsevier B.V.

  16. Human plasma-derived immunoglobulin G fractionated by an aqueous two-phase system, caprylic acid precipitation, and membrane chromatography has a high purity level and is free of detectable in vitro thrombogenic activity.

    Science.gov (United States)

    Vargas, M; Segura, Á; Wu, Y-W; Herrera, M; Chou, M-L; Villalta, M; León, G; Burnouf, T

    2015-02-01

    Instituto Clodomiro Picado has developed an immunoglobulin G (IgG) plasma fractionation process combining a polyethylene glycol/phosphate aqueous two-phase system (ATPS), caprylic acid precipitation and anion-exchange membrane chromatography. We evaluated the purity and in vitro thrombogenicity of such IgG, in line with current international requirements. Contributions of the different production steps to reduce thrombogenicity were assessed at 0·2 l-scale, and then the methodology was scaled-up to a 10 l-scale and final products (n = 3) were analysed. Purity, immunoglobulin composition, and subclass distribution were determined by electrophoretic and immunochemical methods. The in vitro thrombogenic potential was determined by a thrombin generation assay (TGA) using a Technothrombin fluorogenic substrate. Prekallikrein activator (PKA), plasmin, factor Xa, thrombin and thrombin-like activities were assessed using S-2302, S-2251, S-2222, S-2238 and S-2288 chromogenic substrates, respectively, and FXI by an ELISA. The thrombogenicity markers were reduced mostly during the ATPS step and were found to segregate mostly into the discarded liquid upper phase. The caprylic acid precipitation eliminated the residual procoagulant activity. The IgG preparations made from the 10 l-batches contained 100% gamma proteins, low residual IgA and undetectable IgM. The IgG subclass distribution was not substantially affected by the process. TGA and amidolytic activities revealed an undetectable in vitro thrombogenic risk and the absence of proteolytic enzymes in the final product. Fractionating human plasma by an ATPS combined with caprylic acid and membrane chromatography resulted in an IgG preparation of high purity and free of a detectable in vitro thrombogenic risk. © 2014 International Society of Blood Transfusion.

  17. Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

    Directory of Open Access Journals (Sweden)

    Liliana Costa

    2012-06-01

    Full Text Available Photodynamic inactivation (PDI has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.

  18. Plasma Biomedicine in Orthopedics

    Science.gov (United States)

    Hamaguchi, Satsohi

    2012-10-01

    Various effects of plasmas irradiation on cells, tissues, and biomaterials relevant for orthopedic applications have been examined. For direct application of plasmas to living cells or tissues, dielectric barrier discharges (DBDs) with helium flows into ambient air were used. For biomaterial processing, on the other hand, either helium DBDs mentioned above or low-pressure discharges generated in a chamber were used. In this presentation, plasma effects on cell proliferation and plasma treatment for artificial bones will be discussed. First, the conditions for enhanced cell proliferation in vitro by plasma applications have been examined. The discharge conditions for cell proliferation depend sensitively on cell types. Since cell proliferation can be enhanced even when the cells are cultured in a plasma pre-treated medium, long-life reactive species generated in the medium by plasma application or large molecules (such as proteins) in the medium modified by the plasma are likely to be the cause of cell proliferation. It has been found that there is strong correlation between (organic) hydroperoxide generation and cell proliferation. Second, effects of plasma-treated artificial bones made of porous hydroxyapatite (HA) have been examined in vitro and vivo. It has been found that plasma treatment increases hydrophilicity of the surfaces of microscopic inner pores, which directly or indirectly promotes differentiation of mesenchymal stem cells introduced into the pores and therefore causes faster bone growth. The work has been performed in collaboration with Prof. H. Yoshikawa and his group members at the School of Medicine, Osaka University.

  19. Rose Bengal-decorated silica nanoparticles as photosensitizers for inactivation of gram-positive bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Guo Yanyan; Zhang Peng [Department of Chemistry, New Mexico Tech, Socorro, NM 87801 (United States); Rogelj, Snezna, E-mail: pzhang@nmt.edu [Department of Biology, New Mexico Tech, Socorro, NM 87801 (United States)

    2010-02-10

    A new type of photosensitizer, made from Rose Bengal (RB)-decorated silica (SiO{sub 2}-NH{sub 2}-RB) nanoparticles, was developed to inactivate gram-positive bacteria, including Methicillin-resistant Staphylococcus aureus (MRSA), with high efficiency through photodynamic action. The nanoparticles were characterized microscopically and spectroscopically to confirm their structures. The characterization of singlet oxygen generated by RB, both free and immobilized on a nanoparticle surface, was performed in the presence of anthracene-9,10-dipropionic acid. The capability of SiO{sub 2}-NH{sub 2}-RB nanoparticles to inactivate bacteria was tested in vitro on both gram-positive and gram-negative bacteria. The results showed that RB-decorated silica nanoparticles can inactivate MRSA and Staphylococcus epidermidis (both gram-positive) very effectively (up to eight-orders-of-magnitude reduction). Photosensitizers of such design should have good potential as antibacterial agents through a photodynamic mechanism.

  20. Inactivation of poliovirus by chloramine-T.

    Science.gov (United States)

    Gowda, N M; Trieff, N M; Stanton, G J

    1981-01-01

    Since concern has recently been expressed about the presence of genotoxic substances due to chlorination of water and wastewater, chloramine-T (CAT) is proposed as an alternative disinfectant to chlorine. The viricidal properties of chlorine and CAT were compared. Kinetics of inactivation of poliovirus type 2 by chlorine and CAT in chlorine demand-free water were investigated by using a kinetic apparatus. Inactivation of the virus by chlorine and CAT occurred in two steps. The initial linear part of the inactivation curve followed a pseudo-first-order reaction with the virus. An obvious dose-response relationship was demonstrated with CAT. The rate of inactivation of the virus by CAT was faster in acid medium than in alkaline medium. Inactivation kinetic studies were performed at different temperatures, and the kinetic, Arrhenius, and thermodynamic parameters were evaluated. The rate of inactivation of poliovirus type 2 by chlorine was faster than that by CAT under identical conditions. A mechanism for the viral inactivation in acid conditions was proposed which led to a rate equation consistent with the experimental results. The results indicate that CAT may be an effective viricide against poliovirus type 2 in an acid medium. PMID:6271058

  1. Mechanistic Aspects of Adenovirus Serotype 2 Inactivation with Free Chlorine ▿ †

    Science.gov (United States)

    Page, Martin A.; Shisler, Joanna L.; Mariñas, Benito J.

    2010-01-01

    Free chlorine is an effective disinfectant for controlling adenoviruses in drinking water, but little is known about the underlying inactivation mechanisms. The objective of this study was to elucidate the molecular components of adenovirus type 2 (Ad2) targeted by free chlorine during the inactivation process. The effects of free chlorine treatment on several Ad2 molecular components and associated life cycle events were compared to its effect on the ability of adenovirus to complete its life cycle, i.e., viability. Free chlorine treatment of Ad2 virions did not impair their ability to interact with monoclonal antibodies specific for hexon and fiber proteins of the Ad2 capsid, as measured by enzyme-linked immunosorbent assays, nor did it impair their interaction with recombinant, purified Coxsackie-adenovirus receptor (CAR) proteins in vitro. Free chlorine-treated Ad2 virions also retained their ability to bind to CAR receptors on A549 cell monolayers, despite being unable to form plaques, suggesting that free chlorine inactivates Ad2 by inhibiting a postbinding event of the Ad2 life cycle. DNA isolated from Ad2 virions that had been inactivated by free chlorine was able to be amplified by PCR, indicating that genome damage was not the cause of inactivation. However, inactivated Ad2 virions were unable to express E1A viral proteins during infection of A549 host cells, as measured by using immunoblotting. Collectively, these results indicate that free chlorine inactivates adenovirus by damaging proteins that govern life cycle processes occurring after host cell attachment, such as endocytosis, endosomal lysis, or nuclear delivery. PMID:20305026

  2. Inactivation of human antithrombin by neutrophil elastase. Kinetics of the heparin-dependent reaction.

    Science.gov (United States)

    Jordan, R E; Nelson, R M; Kilpatrick, J; Newgren, J O; Esmon, P C; Fournel, M A

    1989-06-25

    Human neutrophil elastase catalyzes the inactivation of antithrombin by a specific and limited proteinolytic cleavage. This inactivation reaction is greatly accelerated by an active anticoagulant heparin subfraction with high binding affinity for antithrombin. A potentially complex reaction mechanism is suggested by the binding of both neutrophil elastase and antithrombin to heparin. The in vitro kinetic behavior of this system was examined under two different conditions: 1) at a constant antithrombin concentration in which the active anticoagulant heparin was varied from catalytic to saturating levels; and 2) at a fixed, saturating heparin concentration and variable antithrombin levels. Under conditions of excess heparin, the inactivation could be continuously monitored by a decrease in the ultraviolet fluorescence emission of the inhibitor. A Km of approximately 1 microM for the heparin-antithrombin complex and a turnover number of approximately 200/min was estimated from these analyses. Maximum acceleratory effects of heparin on the inactivation of antithrombin occur at heparin concentrations significantly lower than those required to saturate antithrombin. The divergence in acceleratory effect and antithrombin binding contrasts with the anticoagulant functioning of heparin in promoting the formation of covalent antithrombin-enzyme complexes and is likely to derive from the fact that neutrophil elastase is not consumed in the inactivation reaction. A size dependence was observed for the heparin effect since an anticoagulantly active octasaccharide fragment of heparin, with avid antithrombin binding activity, was without effect on the inactivation of antithrombin by neutrophil elastase. Despite the completely nonfunctional nature of elastase-cleaved antithrombin and the altered physical properties of the inhibitor as indicated by fluorescence and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the inactivated inhibitor exhibited a circulating half

  3. Inactivation of highly activated spinach leaf sucrose-phosphate synthase by dephosphorylation. [Spinacia oleracea

    Energy Technology Data Exchange (ETDEWEB)

    Huber, J.L. (North Carolina State Univ., Raleigh (United States)); Huber, S.C. (Dept. of Agriculture, Raleigh, NC (United States) North Carolina State Univ., Raleigh (United States)); Hite, D.R.C.; Outlaw, W.H. Jr. (Florida State Univ., Tallahassee (United States))

    1991-01-01

    Spinach (Spinacia oleracea L.) leaf sucrose-phosphate synthase (SPS) can be phosphorylated and inactivated in vitro with ({gamma}-{sup 32}P)ATP. Thus, it was surprising to find that SPS, extracted from leaves fed mannose in the light to highly activate the enzyme, could be inactivated in an ATP-independent manner when desalted crude extracts were preincubated at 25{degrees}C before assay. The spontaneous inactivation involved a loss in activity measured with limiting substrate concentrations in the presence of the inhibitor, Pi, without affecting maximum catalytic activity. The spontaneous inactivation was unaffected by exogenous carrier proteins and protease inhibitors, but was inhibited by inorganic phosphate, fluoride, and molybdate, suggesting that a phosphatase may be involved. Okadaic acid, a potent inhibitor of mammalian type 1 and 2A protein phosphatases, had no effect up to 5 micromolar. Inactivation was stimulated about twofold by exogenous Mg{sup 2+} and was relatively insensitive to Ca{sup 2+} and to pH over the range pH 6.5 to 8.5. Radioactive phosphate incorporated into SPS during labeling of excised leaves with ({sup 32}P)Pi (initially in the dark and then in the light with mannose) was lost with time when desalted crude extracts were incubated at 25 C, and the loss in radiolabel was substantially reduced by fluoride. These results provide direct evidence for action of an endogenous phosphatase(s) using SPS as substrate.

  4. Silence of the fathers: early X inactivation.

    Science.gov (United States)

    Cheng, Mimi K; Disteche, Christine M

    2004-08-01

    X chromosome inactivation is the mammalian answer to the dilemma of dosage compensation between males and females. The study of this fascinating form of chromosome-wide gene regulation has yielded surprising insights into early development and cellular memory. In the past few months, three papers reported unexpected findings about the paternal X chromosome (X(p)). All three studies agree that the X(p) is imprinted to become inactive earlier than ever suspected during embryonic development. Although apparently incomplete, this early form of inactivation insures dosage compensation throughout development. Silencing of the X(p) persists in cells of extraembryonic tissues, but it is erased and followed by random X inactivation in cells of the embryo proper. These findings challenge several aspects of the current view of X inactivation during early development and may have profound impact on studies of pluripotency and epigenetics.

  5. Microbial Inactivation by Ultrasound Assisted Supercritical Fluids

    Science.gov (United States)

    Benedito, Jose; Ortuño, Carmen; Castillo-Zamudio, Rosa Isela; Mulet, Antonio

    A method combining supercritical carbon dioxide (SC-CO2) and high power ultrasound (HPU) has been developed and tested for microbial/enzyme inactivation purposes, at different process conditions for both liquid and solid matrices. In culture media, using only SC-CO2, the inactivation rate of E. coli and S. cerevisiae increased with pressure and temperature; and the total inactivation (7-8 log-cycles) was attained after 25 and 140 min of SC-CO2 (350 bar, 36 °C) treatment, respectively. Using SC-CO2+HPU, the time for the total inactivation of both microorganisms was reduced to only 1-2 min, at any condition selected. The SC-CO2+HPU inactivation of both microorganisms was slower in juices (avg. 4.9 min) than in culture media (avg. 1.5 min). In solid samples (chicken, turkey ham and dry-cured pork cured ham) treated with SC-CO2 and SC-CO2+HPU, the inactivation rate of E. coli increased with temperature. The application of HPU to the SC-CO2 treatments accelerated the inactivation rate of E. coli and that effect was more pronounced in treatments with isotonic solution surrounding the solid food samples. The application of HPU enhanced the SC-CO2 inactivation mechanisms of microorganisms, generating a vigorous agitation that facilitated the CO2 solubilization and the mass transfer process. The cavitation generated by HPU could damage the cell walls accelerating the extraction of vital constituents and the microbial death. Thus, using the combined technique, reasonable industrial processing times and mild process conditions could be used which could result into a cost reduction and lead to the minimization in the food nutritional and organoleptic changes.

  6. In vitro study of 3D PLGA/n-HAp/β-TCP composite scaffolds with etched oxygen plasma surface modification in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Hee-Sang [Department of Dental Materials, School of Dentistry, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju 61452 (Korea, Republic of); Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, 255 Jungang-ro, Sunchon 57922 (Korea, Republic of); Kook, Min-Suk [Department of Oral and Maxillofacial Surgery, School of Dentistry, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju 61452 (Korea, Republic of)

    2016-12-01

    Highlights: • PLGA and PLGA/n-HAp/β-TCP scaffolds were successfully fabricated by 3D printing. • Oxygen plasma etching increases the wettability and surface roughness. • Bioceramics and oxygen plasma etching and could be used to improve the cell affinity. - Abstract: Three-dimensional (3D) scaffolds have many advantageous properties for bone tissue engineering application, due to its controllable properties such as pore size, structural shape and interconnectivity. In this study, effects on oxygen plasma surface modification and adding of nano-hydroxyapatite (n-HAp) and β-tricalcium phosphate (β-TCP) on the 3D PLGA/n-HAp/β-TCP scaffolds for improving preosteoblast cell (MC3T3-E1) adhesion, proliferation and differentiation were investigated. The 3D PLGA/n-HAp/β-TCP scaffolds were fabricated by 3D Bio-Extruder equipment. The 3D scaffolds were prepared with 0°/90° architecture and pore size of approximately 300 μm. In addition 3D scaffolds surface were etched by oxygen plasma to enhance the hydrophilic property and surface roughness. After oxygen plasma treatment, the surface chemistry and morphology were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. And also hydrophilic property was measured by contact angle. The MC3T3-E1 cell proliferation and differentiation were investigated by MTT assay and ALP activity. In present work, the 3D PLGA/HAp/beta-TCP composite scaffold with suitable structure for the growth of osteoblast cells was successfully fabricated by 3D rapid prototyping technique. The surface hydrophilicity and roughness of 3D scaffold increased by oxygen plasma treatment had a positive effect on cell adhesion, proliferation, and differentiation. Furthermore, the differentiation of MC3T3-E1 cell was significantly enhanced by adding of n-HAp and β-TCP on 3D PLGA scaffold. As a result, combination of bioceramics and oxygen plasma treatment showed a synergistic effect on

  7. A specific plasminogen activator inhibitor-1 antagonist derived from inactivated urokinase.

    Science.gov (United States)

    Gong, Lihu; Proulle, Valerie; Fang, Chao; Hong, Zebin; Lin, Zhonghui; Liu, Min; Xue, Guangpu; Yuan, Cai; Lin, Lin; Furie, Barbara; Flaumenhaft, Robert; Andreasen, Peter; Furie, Bruce; Huang, Mingdong

    2016-10-01

    Fibrinolysis is a process responsible for the dissolution of formed thrombi to re-establish blood flow after thrombus formation. Plasminogen activator inhibitor-1 (PAI-1) inhibits urokinase-type and tissue-type plasminogen activator (uPA and tPA) and is the major negative regulator of fibrinolysis. Inhibition of PAI-1 activity prevents thrombosis and accelerates fibrinolysis. However, a specific antagonist of PAI-1 is currently unavailable for therapeutic use. We screened a panel of uPA variants with mutations at and near the active site to maximize their binding to PAI-1 and identified a potent PAI-1 antagonist, PAItrap. PAItrap is the serine protease domain of urokinase containing active-site mutation (S195A) and four additional mutations (G37bR-R217L-C122A-N145Q). PAItrap inhibits human recombinant PAI-1 with high potency (Kd = 0.15 nM) and high specificity. In vitro using human plasma, PAItrap showed significant thrombolytic activity by inhibiting endogenous PAI-1. In addition, PAItrap inhibits both human and murine PAI-1, allowing the evaluation in murine models. In vivo, using a laser-induced thrombosis mouse model in which thrombus formation and fibrinolysis are monitored by intravital microscopy, PAItrap reduced fibrin generation and inhibited platelet accumulation following vascular injury. Therefore, this work demonstrates the feasibility to generate PAI-1 inhibitors using inactivated urokinase. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  8. In vitro study of 3D PLGA/n-HAp/β-TCP composite scaffolds with etched oxygen plasma surface modification in bone tissue engineering

    Science.gov (United States)

    Roh, Hee-Sang; Jung, Sang-Chul; Kook, Min-Suk; Kim, Byung-Hoon

    2016-12-01

    Three-dimensional (3D) scaffolds have many advantageous properties for bone tissue engineering application, due to its controllable properties such as pore size, structural shape and interconnectivity. In this study, effects on oxygen plasma surface modification and adding of nano-hydroxyapatite (n-HAp) and β-tricalcium phosphate (β-TCP) on the 3D PLGA/n-HAp/β-TCP scaffolds for improving preosteoblast cell (MC3T3-E1) adhesion, proliferation and differentiation were investigated. The 3D PLGA/n-HAp/β-TCP scaffolds were fabricated by 3D Bio-Extruder equipment. The 3D scaffolds were prepared with 0°/90° architecture and pore size of approximately 300 μm. In addition 3D scaffolds surface were etched by oxygen plasma to enhance the hydrophilic property and surface roughness. After oxygen plasma treatment, the surface chemistry and morphology were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. And also hydrophilic property was measured by contact angle. The MC3T3-E1 cell proliferation and differentiation were investigated by MTT assay and ALP activity. In present work, the 3D PLGA/HAp/beta-TCP composite scaffold with suitable structure for the growth of osteoblast cells was successfully fabricated by 3D rapid prototyping technique. The surface hydrophilicity and roughness of 3D scaffold increased by oxygen plasma treatment had a positive effect on cell adhesion, proliferation, and differentiation. Furthermore, the differentiation of MC3T3-E1 cell was significantly enhanced by adding of n-HAp and β-TCP on 3D PLGA scaffold. As a result, combination of bioceramics and oxygen plasma treatment showed a synergistic effect on biocompatibility of 3D scaffolds. This result confirms that this technique was useful tool for improving the biocompatibility in bone tissue engineering application.

  9. Photodynamic-induced inactivation of Propionibacterium acnes

    Science.gov (United States)

    Koenig, Karsten; Teschke, M.; Eick, Stephen G.; Pfister, W.; Meyer, Herbert; Halbhuber, Karl-Juergen

    1998-05-01

    We report on photodynamically induced inactivation of the skin bacterium Propionibacterium acnes (P. acnes) using endogenous as well as exogenous photosensitizers and red light sources. P. acnes is involved in the pathogenesis of the skin disease acne vulgaris. The skin bacterium is able to synthesize the metal-free fluorescent porphyrins protoporphyrin IX (PP) and coproporphyrin (CP) as shown by in situ spectrally-resolved detection of natural autofluorescence of human skin and bacteria colonies. These naturally occurring intracellular porphyrins act as efficient endogenous photosensitizers. Inactivation of P. acnes suspensions was achieved by irradiation with He-Ne laser light in the red spectral region (632.8 nm). We monitored the photodynamically-induced death of single bacteria using a fluorescent viability kit in combination with confocal laser scanning microscopy. In addition, the photo-induced inactivation was calculated by CFU (colony forming units) determination. We found 633 nm-induced inactivation (60 mW, 0.12 cm2 exposure area, 1 hour irradiation) of 72% in the case of non-incubated bacteria based on the destructive effect of singlet oxygen produced by red light excited endogenous porphyrins and subsequent energy transfer to molecular oxygen. In order to achieve a nearly complete inactivation within one exposure procedure, the exogenous photosensitizer Methylene Blue (Mb) was added. Far red exposure of Mb-labeled bacteria using a krypton ion laser at 647 nm and 676 nm resulted in 99% inactivation.

  10. Acceleration of the thrombin inactivation of single chain urokinase-type plasminogen activator (pro-urokinase) by thrombomodulin

    NARCIS (Netherlands)

    Munk, G.A.W. de; Groeneveld, E.; Rijken, D.C.

    1991-01-01

    The in vitro effects of thrombomodulin on the inactivation of single chain urokinase-type plasminogen activator (scu-PA) by thrombin were investigated by incubating scu-PA with varying concentrations of human thrombin, in both the absence and presence of soluble rabbit thrombomodulin. 50%

  11. THE INVITRO INACTIVATION OF 13 BETA-LACTAM ANTIBIOTICS BY OTHER MECHANISMS THAN ADSORPTION TO FECAL SUBSTANCE

    NARCIS (Netherlands)

    DEVRIESHOSPERS, H; JANSEN, G; TONK, R; OENEMA, D; VANDERWAAIJ, D

    1993-01-01

    We have investigated the antibiotic inactivating capacity of intestinal contents in vitro in faeces. In the presently reported study the influence of beta-lactamase catalyzed hydrolysis on the antimicrobial activity of 13 commonly used beta-lactam antibiotics was investigated, while the influence of

  12. Pharmacokinetics of tildipirosin in porcine plasma, lung tissue, and bronchial fluid and effects of test conditions on in vitro activity against reference strains and field isolates of Actinobacillus pleuropneumoniae.

    Science.gov (United States)

    Rose, M; Menge, M; Bohland, C; Zschiesche, E; Wilhelm, C; Kilp, S; Metz, W; Allan, M; Röpke, R; Nürnberger, M

    2013-04-01

    The pharmacokinetics of tildipirosin (Zuprevo(®) 40 mg/mL solution for injection for pigs), a novel 16-membered-ring macrolide for the treatment for swine respiratory disease (SRD), was investigated in studies collecting blood plasma and postmortem samples of lung tissue and bronchial fluid (BF) from swine. In view of factors influencing the in vitro activity of macrolides, and for the interpretation of tildipirosin pharmacokinetics in relation to minimum inhibitory concentrations (MIC), additional experiments were conducted to study the effects of pH, carbon dioxide-enriched atmosphere, buffers, and serum on tildipirosin MICs for various reference strains and Actinobacillus (A.) pleuropneumoniae field isolates. After single intramuscular (i.m.) injection at 4 mg/kg body weight, maximum plasma concentration (Cmax) was 0.9 μg/mL observed within 23 min (Tmax ). Mean residence time from the time of dosing to the time of last measurable concentration (MRTlast) and terminal half-life (T1/2) both were about 4 days. A dose-response relationship with no significant sex effect is observed for area under the plasma concentration-time curve from time 0 to the last sampling time with a quantifiable drug concentration (AUClast) over the range of doses up to 6 mg/kg. However, linear dose proportionality could not be proven with statistical methods. The time-concentration profile of tildipirosin in BF and lung far exceeded that in blood plasma. In lung, tildipirosin concentrations reached 3.1 μg/g at 2 h, peaked at 4.3 μg/g at day 1, and slowly declined to 0.8 μg/g at day 17. In BF, tildipirosin levels were 14.3, 7.0, and 6.5 μg/g at days 5, 10, and 14. T1/2 in lung was ∼7 days. Tildipirosin is rapidly and extensively distributed to the respiratory tract followed by slow elimination. Culture media pH and carbon dioxide-enriched atmosphere (CO2 -EA) had a marked impact on in vitro activity of tildipirosin in reference strains of various rapidly growing aerobic and

  13. [Influence of intravenous injection of fucoidan from brown seaweed Fucus evanescens by plasma rabbits anticoagulant activity and neutralisation by sulphate protamin of fucoidans antithrombin activity in vitro].

    Science.gov (United States)

    Lapikova, E S; Drozd, N N; Makarov, V A; Zviagintseva, T N; Shevchenko, N M; Kuznetsova, T A; Besednova, N N

    2012-01-01

    With fucoidan from Fucus evanescens dose increase from 1 to 5 mg/kg plasma coagulation time in test A(see symbol)TB increases. Sulphate protamin in final concentration 0.67-1.35 mkg/ml will neutralise antithrombin activity of fucoidans from brown seaweed Fucus evanescens and Laminaria cichorioides. The gravimetrichesky relation for the investigated samples makes an antidot/anticoagulant 1.

  14. [Comparative study of in vitro and in vivo effect of ouabain and calixarene C107 on Na+,K(+)-ATPase activity in plasma membranes of rat hepatocytes].

    Science.gov (United States)

    Tsymbaliuk, O V; Kosterin, S O; Rodik, R V; Kal'chenko, V I

    2010-01-01

    The comparative study of influence of ouabain and calixarene C107, and the structure component of this calixarene--fragment M3, in the conditions of in vitro and chronic action in vivo on Na+, K(+)-ATPase activity was carried out on the fractions of plasmatic membranes (PM) of the rat hepatocytes. A general property in the conditions in vitro is the ability of calixarene C107 and ouabain (both substances were in the concentration of 1 mM) to inhibit PM Na+, K(+)-ATPase of rat hepatocytes. However, in the case of activities of calixarene C107 and ouabain in the conditions in vivo heterogeneous action on Mg2(+)-ATPase and Mg2+, Na+, K(+)-ATPase activities takes place: total activity in the conditions of injection of increased concentrations of ouabain remains without changes, but Mg2(+)-ATPase activity significantly grows; in analogous conditions under the action of calixarene C107 both these activities decrease twice in comparison with control. Both under the in vitro and in vivo conditions, M3 fragment (the structural component of C107) does not change the values of investigated enzymatic activities. The biochemical mechanisms of calixarene C107 action on Na+, K(+)-ATPase activity in PM of rat hepatocytes are discussed.

  15. The influence of raw and processed garlic and onions on plasma classical and non-classical atherosclerosis indices: investigations in vitro and in vivo.

    Science.gov (United States)

    Gorinstein, Shela; Leontowicz, Hanna; Leontowicz, Maria; Jastrzebski, Zenon; Najman, Katarzyna; Tashma, Zev; Katrich, Elena; Heo, Buk-Gu; Cho, Ja-Yong; Park, Yun-Jum; Trakhtenberg, Simon

    2010-05-01

    Garlic and white and red varieties of onion were subjected to processing by a variety of culinary methods, and bioactive compounds then determined. For in vivo studies, 84 male Wistar rats were randomly divided into 14 diet groups, each of six rats, including two control groups (one with no supplementation and one with cholesterol supplementation only). During the 30-day trial, the basal diets of the other 12 groups were supplemented with 1% cholesterol and raw or processed vegetables. Both raw red onion and red onion subjected to blanching for 90 s hindered the rise in plasma lipids more than the other vegetables studied in the supplemented diets. The decrease in antioxidant activity compared to the cholesterol-supplemented control group was significantly less for the group fed with red onion subjected to blanching for 90 s. No histological changes were detected in the studied organs of rats that had been fed cholesterol. In conclusion, blanching for 90 s most fully preserved the bioactive compounds and antioxidant potentials, and hindered the rise in plasma lipid levels and the decrease in plasma antioxidant activity of rats fed cholesterol. Alkaline phosphatase levels correlated with classical atherosclerosis indices, and determination of alkaline phosphatase is suggested as an additional index in atherosclerosis testing. Copyright (c) 2009 John Wiley & Sons, Ltd.

  16. In vitro antibacterial and cytotoxic activities of plasma-modified polyethylene terephthalate nonwoven dressing with aqueous extract of Rhizome Atractylodes macrocephala.

    Science.gov (United States)

    Shu, Yi-Ting; Kao, Kuo-Ting; Weng, Ching-Sung

    2017-08-01

    In this study, a natural and non-cytotoxic antibacterial dressing containing aqueous extract of Rhizome Atractylodes macrocephala (RAM), which has been widely used in traditional herbal medicine and documented with antibacterial activities in literatures, was developed by aid of the extraction technique, nonwoven substrates and plasma-induced grafting technology. The effectiveness of these herbal antibacterial dressings with different treatment were investigated through the assays of grafting yield, SEM, FTIR, antibacterial activities and cytotoxicity. The remarkable grafting of RAM extracts onto PET nonwovens after plasma treatment, with the best of 51.24%, revealed that the surface property of PET substrates were improved effectively, and the successful grafting can also be confirmed from SEM and FTIR results by the appearance of new peaks associated with the presence of polysaccharides and flavonoids in aqueous extracts. The plasma treatment further increased the broad-spectrum antibacterial effects of PET nonwoven dressings containing RAM extract with the best inhibition width of 12.84mm and 16.81mm against S. aureus and E. coli, respectively, which was no less than ones of commercial antibacterial dressings. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Inactivation of pathogenic bacteria in food matrices: high pressure processing, photodynamic inactivation and pressure-assisted photodynamic inactivation

    Science.gov (United States)

    Cunha, A.; Couceiro, J.; Bonifácio, D.; Martins, C.; Almeida, A.; Neves, M. G. P. M. S.; Faustino, M. A. F.; Saraiva, J. A.

    2017-09-01

    Traditional food processing methods frequently depend on the application of high temperature. However, heat may cause undesirable changes in food properties and often has a negative impact on nutritional value and organoleptic characteristics. Therefore, reducing the microbial load without compromising the desirable properties of food products is still a technological challenge. High-pressure processing (HPP) can be classified as a cold pasteurization technique, since it is a non-thermal food preservation method that uses hydrostatic pressure to inactivate spoilage microorganisms. At the same time, it increases shelf life and retains the original features of food. Photodynamic inactivation (PDI) is also regarded as promising approach for the decontamination of food matrices. In this case, the inactivation of bacterial cells is achieved by the cytotoxic effects of reactive oxygens species (ROS) produced from the combined interaction of a photosensitizer molecule, light and oxygen. This short review examines some recent developments on the application of HPP and PDI with food-grade photosensitizers for the inactivation of listeriae, taken as a food pathogen model. The results of a proof-of-concept trial of the use of high-pressure as a coadjutant to increase the efficiency of photodynamic inactivation of bacterial endospores is also addressed.

  18. C1-esterase inhibitor blocks T lymphocyte proliferation and cytotoxic T lymphocyte generation in vitro

    DEFF Research Database (Denmark)

    Nissen, Mogens Holst; Bregenholt, S; Nording, J A

    1998-01-01

    We have previously shown that activated C1s complement and activated T cells cleave beta2-microglobulin (beta2m) in vitro leading to the formation of desLys58 beta2m. This process can specifically be inhibited by C1-esterase inhibitor (C1-inh). Furthermore we showed that exogenously added desLys58...... beta2m in nanomolar amounts to a one-way allogenic mixed lymphocyte culture (MLC) increased the endogenous production of IL-2 and the generation of allo-specific cytotoxic T lymphocytes. C1-inh was purified from fresh human plasma and added to human or murine MLC and mitogen-stimulated lymphocyte...... cultures grown in the presence of complement-inactivated serum. Read-outs were cell proliferation, lymphokine production and development of T cell-mediated cytotoxicity. We found that addition of C1-inh to MLC and mitogen-exposed murine and human lymphocyte cultures inhibited proliferation, the development...

  19. Effect of an extract of Artemisia vulgaris L. (Mugwort on the in vitro labeling of red blood cells and plasma proteins with technetium-99m

    Directory of Open Access Journals (Sweden)

    Danielle Amorim Terra

    2007-09-01

    Full Text Available The aim of this work was to evaluate the effect of an extract of the Artemisia vulgaris L. (mugwort on the labeling of blood constituents with technetium-99m (99mTc. Blood samples from Wistar rats were incubated with a mugwort extract and the radiolabeling of blood constituents was carried out. Plasma and blood cells were separated by centrifugation. Aliquots of plasma and blood cells were also precipitated with trichloroacetic acid and centrifuged to isolate soluble and insoluble fractions of plasma and blood cells. Radioactivity in each fraction was counted and the percentages of radioactivity (%ATI was calculated. Mugwort extract decreased significantly (pO objetivo desse trabalho foi avaliar o efeito da Artemisia vulgaris L.(artemisa na marcação dos constituintes sangüíneos com tecnécio-99m (99mTc. Amostras de sangue obtidas de ratos Wistar foram incubadas com um extrato de artemisa e o processo de radiomarcação dos constituintes sangüíneos foi realizado. Plasma e células sangüíneas foram isoladas por centrifugação. Alíquotas de plasma e células sangüíneas foram também precipitadas com ácido tricloroacético para isolamento de frações solúvel e insolúvel. A radiatividade em cada fração foi contada e as porcentagens de radioatividade (%ATI foram calculadas. O extrato de artemisa diminuiu significantemente (p<0,05 a %ATI nas células sanguíneas e nas proteínas celulares. A análise dos resultados indicou que o extrato de artemisa apresentaria substâncias que interferir no transporte de íons estanoso e/ou pertecnetato através da membrana do eritrócito alterando a marcação das células sangúineas com 99mTc.

  20. Decontamination of foods by cold plasma

    Science.gov (United States)

    Cold plasma is a novel nonthermal food processing technology for meats, poultry, fruits, and vegetables. This flexible sanitizing method uses electricity and a carrier gas, such as air, oxygen, nitrogen, or helium to inactivate microbes without the use of conventional antimicrobial chemical agents. ...

  1. Investigation on physicochemical properties of plasma-activated water for the application of medical device sterilization

    Science.gov (United States)

    Abuzairi, Tomy; Ramadhanty, Savira; Puspohadiningrum, Dini Fithriaty; Ratnasari, Anita; Poespawati, Nji Raden; Purnamaningsih, Retno Wigajatri

    2018-02-01

    Plasma activated water (PAW) is a new approach to bacterial inactivation while ensuring safety and maintaining the properties of the material sterilized. Reported research imply that PAW has been effective for inactivation of bacteria. In this paper, plasma treatment using atmospheric pressure plasma was demonstrated. Physicochemical properties such as pH, temperature, ORP, and nitrite concentration were assessed. The results suggest that plasma treatment causes acidification on water and generate reactive species, creating an environment suitable for killing bacteria. Therefore, plasma activated water is an assuring method for medical devices sterilization.

  2. Preservation of imaging capability in sensitive ultrasound contrast agents after indirect plasma sterilization.

    Science.gov (United States)

    Albala, Lorenzo; Ercan, Utku K; Joshi, Suresh G; Eisenbrey, John R; Teraphongphom, Nutte; Wheatley, Margaret A

    2015-10-15

    Many injectables are not amenable to standard sterilization methods, which destroy sensitive materials. This is particularly true for ultrasound contrast agents (UCA) consisting of gas bubbles stabilized by a surfactant or polymer shell. We investigated a new method to achieve safe and effective sterilization in production by introducing dielectric-barrier discharge non-thermal plasma. A dielectric-barrier discharge was generated to first produce plasma-treated phosphate-buffered saline (PTPBS), which was used as a sterilant solution for our UCA SE61, avoiding direct heat, pressure, chemicals, or radiation. Treated samples were tested for acoustic properties in vitro and in a flow phantom, and for sterility by standard methods. Three minutes plasma treatment of phosphate-buffered saline (PBS) proved effective. The samples showed significant inactivation of inoculated bacteria upon PTPBS treatment as compared to un-treated-PBS (p=0.0022). The treated and untreated samples showed no statistical significance (p>0.05) in acoustic response or bubble diameter (mean±SEM: 2.52±0.31 μm). Nile Red was used to model intercalation of drug in the hydrophobic shell, intercalated successfully into SE61, and was unaffected by plasma treatment. The PTPBS completely sterilized suspensions of UCA, and it did not compromise the acoustic properties of the agent or its ability to retain a hydrophobic compound. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. In vitro and ex vivo approach for anti-urolithiatic potential of bioactive fractions of gokhru with simultaneous HPLC analysis of six major metabolites and their exploration in rat plasma.

    Science.gov (United States)

    Sharma, Ikshit; Khan, Washim; Ahmad, Sayeed

    2017-12-01

    Tribulus terrestris L. (Zygophyllaceae) fruits have long been used in traditional systems of medicine for the treatment of various urinary diseases including urolithiasis. To explore the anti-urolithiatic potential of gokhru and to develop an analytical method for quantitative estimation of metabolites for its quality control. Aqueous extract of gokhru fruit was prepared through maceration followed by decoction to produce a mother extract, which was further used for polarity-based fractionations. In vitro and ex vivo anti-urolithiatic activity of mother extract and fractions at different concentration (100-1000 μg/mL) were carried out using aggregation assay in synthetic urine and in rat plasma, however, nucleation assay for 30 min was done using confocal microscopy. A simultaneous HPLC method has been developed for quantification of diosgenin, catechin, rutin, gallic acid, tannic acid and quercetin in mother extract and in fractions. The extraction resulted in 14.5% of w/w mother extract, however, polarity-based fractionation yielded 2.1, 2.6, 1.5, 1.3 and 6.1% w/w of hexane, toluene, dichloromethane (DCM), n-butanol and water fractions, respectively. In vitro and ex vivo studies showed a significant anti-urolithiatic potential of n-butanol fraction. Further, HPLC analysis revealed significantly (p vitro and ex vivo studies demonstrated potent anti-urolithiatic activity of n-butanol fraction which can be developed as new phytopharmaceuticals for urolithiasis. HPLC method can be used for quality control and pharmacokinetic studies of gokhru.

  4. Kinetics of Hydrothermal Inactivation of Endotoxins ▿

    Science.gov (United States)

    Li, Lixiong; Wilbur, Chris L.; Mintz, Kathryn L.

    2011-01-01

    A kinetic model was established for the inactivation of endotoxins in water at temperatures ranging from 210°C to 270°C and a pressure of 6.2 × 106 Pa. Data were generated using a bench scale continuous-flow reactor system to process feed water spiked with endotoxin standard (Escherichia coli O113:H10). Product water samples were collected and quantified by the Limulus amebocyte lysate assay. At 250°C, 5-log endotoxin inactivation was achieved in about 1 s of exposure, followed by a lower inactivation rate. This non-log-linear pattern is similar to reported trends in microbial survival curves. Predictions and parameters of several non-log-linear models are presented. In the fast-reaction zone (3- to 5-log reduction), the Arrhenius rate constant fits well at temperatures ranging from 120°C to 250°C on the basis of data from this work and the literature. Both biphasic and modified Weibull models are comparable to account for both the high and low rates of inactivation in terms of prediction accuracy and the number of parameters used. A unified representation of thermal resistance curves for a 3-log reduction and a 3 D value associated with endotoxin inactivation and microbial survival, respectively, is presented. PMID:21193667

  5. Pattern of secretion of pregnancy-associated plasma protein-A (PAPP-A) during pregnancies complicated by fetal aneuploidy, in vivo and in vitro.

    Science.gov (United States)

    Leguy, Marie Clémence; Brun, Stephanie; Pidoux, Guillaume; Salhi, Houria; Choiset, Agnes; Menet, Marie Claude; Gil, Sophie; Tsatsaris, Vassilis; Guibourdenche, Jean

    2014-12-28

    Pregnancy-associated placental protein-A (PAPP-A) is a metalloprotease which circulates as an hetero-tetramer in maternal blood. Its maternal serum concentration in fetal trisomy 21 is decreased during the first trimester, so that PAPP-A is a useful screening biomarker. However, the regulation of PAPP-A placental secretion is unclear. We therefore investigated the secretion of PAPP-A in pregnancies complicated by fetal aneuploidies, both in vivo and in vitro. Maternal serum collected between 10 WG and 33 WG during 7014 normal pregnancies and 96 pregnancies complicated by fetal trisomy 21, 18, and 13 were assayed for PAPP-A using the Immulite 2000xpi system®. The pregnancies were monitored using ultrasound scanning, fetal karyotyping and placental analysis. Villous cytotrophoblasts were isolated from normal and trisomic placenta and cultured to investigate PAPP-A secretion in vitro (n=6). An increased nuchal translucency during the first trimester is a common feature of many chromosomal defect but each aneuploidy has its own syndromic pattern of abnormalities detectable at the prenatal ultrasound scanning and confirmed at the fetal examination thereafter. PAPP-A levels rise throughout normal pregnancy whereas in trisomy 21, PAPP-A levels were significantly decreased, but only during the first trimester. PAPP-A levels were decreased in trisomy 13 and sharply in trisomy 18, whatever the gestational age. In vitro, PAPP-A secretion was decreased in aneuploidy, and associated with decreased hCG secretion in Trisomy 21 and 18. These biochemical profiles did not appear to be linked to any specific histological lesions affecting the placenta. These profiles may reflect different quantitative and qualitative placental dysfunctions in the context of these aneuploidies.

  6. Surface properties and in vitro analyses of immobilized chitosan onto polypropylene non-woven fabric surface using antenna-coupling microwave plasma.

    Science.gov (United States)

    Tyan, Yu-Chang; Liao, Jiunn-Der; Lin, Shu-Ping

    2003-09-01

    Antenna coupling microwave plasma enables a highly efficient and oxidative treatment of the outermost surface of polypropylene (PP) non-woven fabric within a short time period. Subsequently, grafting copolymerization with acrylic acid (AAc) makes the plasma-treated fabric durably hydrophilic and excellent in water absorbency. With high grafting density and strong water affinity, the pAAc-grafted fabric greatly becomes feasible as an intensive absorbent and as a support to promote chitosan-immobilization through amide bonds. Experimental result demonstrated that surface analyses by FTIR-ATR have shown that R-CONH-R', amide binding were emerged between pAAc and chitosan. The XPS measurements on C(1s) 286.0 eV (C-OH), 286.5 eV (C-N) and 288.1 eV (O=C-NH) also could be found. Bioactivity assessments on the chitosan-immobilized surfaces were anticipated by activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen concentration. By means of cell counter we counted the ratio of blood cell adhesion on the modified fabric matrix. After human plasma incubated with the chitosan-immobilized PP fabrics, the required time for aPTT and blood cell adhesion increased significantly, while fibrinogen concentration and TT did not change. Due to the capability of anticoagulation and cell adhesion, the chitosan-immobilized PP fabric can be used as the substrate for cell culturing and then developed the wound-dressing substitute for second-degree burn.

  7. Physiological and transcriptional response of Bacillus cereus treated with low-temperature nitrogen gas plasma

    NARCIS (Netherlands)

    Mols, J.M.; Mastwijk, H.C.; Nierop Groot, M.N.; Abee, T.

    2013-01-01

    Aims - This study was conducted to investigate the inactivation kinetics of Bacillus cereus vegetative cells upon exposure to low-temperature nitrogen gas plasma and to reveal the mode of inactivation by transcriptome profiling. Methods and Results - Exponentially growing B. cereus cells were

  8. Characterization of Damage to Bacteria and Bio-macromolecules Caused by (V)UV Radiation and Particles Generated by a Microscale Atmospheric Pressure Plasma Jet

    Science.gov (United States)

    Lackmann, Jan-Wilm; Schneider, Simon; Narberhaus, Franz; Benedikt, Jan; Bandow, Julia E.

    Atmospheric pressure plasma jets effectively inactivate bacteria on ­surfaces including infected tissues. This is due to the combined effects of (V)UV radiation, reactive oxygen and nitrogen species, ions, and high electric fields. A well-characterized microscale atmospheric pressure plasma jet (μ-APPJ) operated with He/O2 gas mixture has been modified so that (V)UV radiation and heavy reactive particles (mainly O3 molecules and O atoms) emitted from the plasma source can be separated effectively. The separation is achieved by an additional lateral He flow, which diverts the heavy particles from the jet axis. The new jet geometry is called X-Jet. Separation of different plasma components allows studying their effects on living cells and bio-macromolecules separately. First, the effectiveness of the separation of different plasma components was demonstrated by treatment of monolayers of vegetative Bacillus subtilis cells. To characterize effects on nucleic acids, dried plasmid DNA and total cellular RNA were treated with the separated plasma components. Dried bovine serum albumin was used to study etching effects of (V)UV radiation and heavy particles on proteins. We found that heavy particles emitted from the X-Jet kill vegetative cells more effectively than the (V)UV radiation from this type of plasma source. All bio-macromolecules investigated, DNA, RNA, and proteins, are affected by plasma treatment. DNA exposed to the (V)UV-channel of the jet seems to be prone to thymine dimer formation not only in vitro but also in vivo as indicated by induction of the photolyase in Escherichia coli, while DNA strand breaks occur under both jet channels. Heavy particles seem more effective in degrading RNA and in etching protein in vitro.

  9. Inactivation of glutathione peroxidase by benzaldehyde.

    Science.gov (United States)

    Tabatabaie, T; Floyd, R A

    1996-12-01

    Chronic benzaldehyde exposure is known to cause central nervous system (CNS) disturbances. Previous studies have shown that benzaldehyde causes the formation of reactive oxygen species (ROS) in rat synaptosomal fractions. Benzaldehyde has also been implicated in ROS formation in the CNS of rats treated with toluene. We have found that benzaldehyde effectively inactivates the antioxidant enzyme glutathione peroxidase (Ki approximately 15 microM), but has no effect on the other antioxidant enzymes tested: catalase, superoxide dismutase, and glutathione reductase. This effect has been found to be specific to benzaldehyde since other structurally related and unrelated aldehydes tested were found to be devoid of inactivating capacity toward glutathione peroxidase. Since glutathione peroxidase is the main enzyme responsible for removal of hydrogen peroxide and organic hydroperoxides in brain, its inactivation by benzaldehyde may be a main contributor to the observed ROS formation and the observed neurotoxicity caused by either benzaldehyde or toluene exposure.

  10. Neutrophils Turn Plasma Proteins into Weapons against HIV-1.

    Directory of Open Access Journals (Sweden)

    Cornelia Speth

    Full Text Available As a consequence of innate immune activation granulocytes and macrophages produce hypochlorite/hypochlorous acid (HOCl via secretion of myeloperoxidase (MPO to the outside of the cells, where HOCl immediately reacts with proteins. Most proteins that become altered by this system do not belong to the invading microorganism but to the host. While there is no doubt that the myeloperoxidase system is capable of directly inactivating HIV-1, we hypothesized that it may have an additional indirect mode of action. We show in this article that HOCl is able to chemically alter proteins and thus turn them into Idea-Ps (Idea-P = immune defence-altered protein, potent amyloid-like and SH-groups capturing antiviral weapons against HIV-1. HOCl-altered plasma proteins (Idea-PP have the capacity to bind efficiently and with high affinity to the HIV-1 envelope protein gp120, and to its receptor CD4 as well as to the protein disulfide isomerase (PDI. Idea-PP was able to inhibit viral infection and replication in a cell culture system as shown by reduced number of infected cells and of syncytia, resulting in reduction of viral capsid protein p24 in the culture supernatant. The unmodified plasma protein fraction had no effect. HOCl-altered isolated proteins antithrombin III and human serum albumin, taken as representative examples of the whole pool of plasma proteins, were both able to exert the same activity of binding to gp120 and inhibition of viral proliferation. These data offer an opportunity to improve the understanding of the intricacies of host-pathogen interactions and allow the generation of the following hypothetical scheme: natural immune defense mechanisms generate by posttranslational modification of plasma proteins a potent virucidal weapon that immobilizes the virus as well as inhibits viral fusion and thus entry into the host cells. Furthermore simulation of this mechanism in vitro might provide an interesting new therapeutic approach against

  11. Kinetics of Hydrothermal Inactivation of Endotoxins ▿

    OpenAIRE

    Li, Lixiong; Wilbur, Chris L.; Mintz, Kathryn L.

    2011-01-01

    A kinetic model was established for the inactivation of endotoxins in water at temperatures ranging from 210°C to 270°C and a pressure of 6.2 × 106 Pa. Data were generated using a bench scale continuous-flow reactor system to process feed water spiked with endotoxin standard (Escherichia coli O113:H10). Product water samples were collected and quantified by the Limulus amebocyte lysate assay. At 250°C, 5-log endotoxin inactivation was achieved in about 1 s of exposure, followed by a lower ina...

  12. Micro-Biocidal Activity of Yeast Cells by Needle Plasma Irradiation at Atmospheric Pressure

    Science.gov (United States)

    Kurumi, Satoshi; Takahashi, Hideyuki; Taima, Tomohito; Suzuki, Kaoru; Hirose, Hideharu; Masutani, Shigeyuki

    In this study, we report on the biocidal activity technique by needle helium plasma irradiation at atmospheric pressure using borosilicate capillary nozzle to apply for the oral surgery. The diameter of needle plasma was less than 50 µm, and temperature of plasma irradiated area was less than body temperature. Needle plasma showed emission due to OH and O radical. Raman spectra and methylene blue stain showed yeast cells were inactivated by needle plasma irradiation.

  13. Kinetics and thermodynamics of the thermal inactivation and chaperone assisted folding of zebrafish dihydrofolate reductase.

    Science.gov (United States)

    Thapliyal, Charu; Jain, Neha; Rashid, Naira; Chaudhuri Chattopadhyay, Pratima

    2017-11-11

    The maintenance of thermal stability is a major issue in protein engineering as many proteins tend to form inactive aggregates at higher temperatures. Zebrafish DHFR, an essential protein for the survival of cells, shows irreversible thermal unfolding transition. The protein exhibits complete unfolding and loss of activity at 50 °C as monitored by UV-Visible, fluorescence and far UV-CD spectroscopy. The heat induced inactivation of zDHFR follows first-order kinetics and Arrhenius law. The variation in the value of inactivation rate constant, k with increasing temperatures depicts faster inactivation at elevated temperatures. We have attempted to study the chaperoning ability of a shorter variant of GroEL (minichaperone) and compared it with that of conventional GroEL-GroES chaperone system. Both the chaperone system prevented the aggregation and assisted in refolding of zDHFR. The rate of thermal inactivation was significantly retarded in the presence of chaperones which indicate that it enhances the thermal stability of the enzyme. As minichaperone is less complex, and does not require high energy co-factors like ATP, for its function as compared to conventional GroEL-GroES system, it can act as a very good in vitro as well as in vivo chaperone model for monitoring assisted protein folding phenomenon. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. EDQM biological reference preparation for rabies vaccine (inactivated) for veterinary use.

    Science.gov (United States)

    Daas, A; Bruckner, L; Milne, C

    2015-01-01

    Rabies is a deadly zoonotic disease. Control of rabies in animals by vaccination is an important strategy to protect humans from infection and control the spread of the disease. Requirements for the quality control of rabies vaccines (inactivated) for veterinary use include an in vivo quantitative potency determination as outlined in the Ph. Eur. monograph 0451. Performance of this assay requires a reference preparation calibrated in International Units (IU). A European Pharmacopeia (Ph. Eur.) Biological Reference Preparation (BRP) for rabies vaccines (inactivated) for veterinary use, calibrated in IU, has been established for this purpose. Due to the dwindling stocks of the current batch (batch 4) of Ph. Eur. BRP for rabies vaccines (inactivated) for veterinary use, a collaborative study was run as part of the EDQM Biological Standardisation Programme to establish BRP batch 5. Ten laboratories, including Official Medicines Control Laboratories and manufacturers, participated. The candidate BRP5 was assayed against the 6(th) International Standard for rabies vaccine using the in vivo vaccination-challenge assay (monograph 0451) to assign a potency value. The candidate was also compared to BRP batch 4 to establish continuity. Taking into account the results from the comparisons a potency of 10 IU/vial was assigned and in March 2015 the Ph. Eur. Commission adopted the material as Ph. Eur. BRP for rabies vaccines (inactivated) for veterinary use batch 5. In addition to the in vivo assay 3 laboratories tested the candidate material using their in-house in vitro assays for information.

  15. Inactivated coxsackievirus A10 experimental vaccines protect mice against lethal viral challenge.

    Science.gov (United States)

    Shen, Chaoyun; Liu, Qingwei; Zhou, Yu; Ku, Zhiqiang; Wang, Lili; Lan, Ke; Ye, Xiaohua; Huang, Zhong

    2016-09-22

    Coxsackievirus A10 (CVA10) has become one of the major causative agents of hand, foot and mouth disease (HFMD). It is now recognized that CVA10 should be targeted for vaccine development. We report here that β-propiolactone inactivated whole-virus based CVA10 vaccines can elicit protective immunity in mice. We prepared two inactivated CVA10 experimental vaccines derived from the prototype strain CVA10/Kowalik and from a clinical isolate CVA10/S0148b, respectively. Immunization with the experimental vaccines elicited CVA10-specific serum antibodies in mice. The antisera from vaccinated mice could potently neutralize in vitro infection with either homologous or heterologous CVA10 strains. Importantly, passive transfer of the anti-CVA10 sera protected recipient mice against CVA10/Kowalik or CVA10/S0148b infections. Moreover, active immunization with the inactivated vaccines also conferred protection against homologous and heterologous infections in mice. Collectively, our results demonstrate the proof-of-concept for inactivated whole-virus based CVA10 vaccines. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Reversible Heat-Induced Inactivation of Chimeric β-Glucuronidase in Transgenic Plants1

    Science.gov (United States)

    Almoguera, Concepción; Rojas, Anabel; Jordano, Juan

    2002-01-01

    We compared the expression patterns in transgenic tobacco (Nicotiana tabacum) of two chimeric genes: a translational fusion to β-glucuronidase (GUS) and a transcriptional fusion, both with the same promoter and 5′-flanking sequences of Ha hsp17.7 G4, a small heat shock protein (sHSP) gene from sunflower (Helianthus annuus). We found that immediately after heat shock, the induced expression from the two fusions in seedlings was similar, considering chimeric mRNA or GUS protein accumulation. Surprisingly, we discovered that the chimeric GUS protein encoded by the translational fusion was mostly inactive in such conditions. We also found that this inactivation was fully reversible. Thus, after returning to control temperature, the GUS activity was fully recovered without substantial changes in GUS protein accumulation. In contrast, we did not find differences in the in vitro heat inactivation of the respective GUS proteins. Insolubilization of the chimeric GUS protein correlated with its inactivation, as indicated by immunoprecipitation analyses. The inclusion in another chimeric gene of the 21 amino-terminal amino acids from a different sHSP lead to a comparable reversible inactivation. That effect not only illustrates unexpected post-translational problems, but may also point to sequences involved in interactions specific to sHSPs and in vivo heat stress conditions. PMID:12011363

  17. Protein Phosphatase 1 inactivates Mps1 to ensure efficient Spindle Assembly Checkpoint silencing.

    Science.gov (United States)

    Moura, Margarida; Osswald, Mariana; Leça, Nelson; Barbosa, João; Pereira, António J; Maiato, Helder; Sunkel, Claudio E; Conde, Carlos

    2017-05-02

    Faithfull genome partitioning during cell division relies on the Spindle Assembly Checkpoint (SAC), a conserved signaling pathway that delays anaphase onset until all chromosomes are attached to spindle microtubules. Mps1 kinase is an upstream SAC regulator that promotes the assembly of an anaphase inhibitor through a sequential multi-target phosphorylation cascade. Thus, the SAC is highly responsive to Mps1, whose activity peaks in early mitosis as a result of its T-loop autophosphorylation. However, the mechanism controlling Mps1 inactivation once kinetochores attach to microtubules and the SAC is satisfied remains unknown. Here we show in vitro and in Drosophila that Protein Phosphatase 1 (PP1) inactivates Mps1 by dephosphorylating its T-loop. PP1-mediated dephosphorylation of Mps1 occurs at kinetochores and in the cytosol, and inactivation of both pools of Mps1 during metaphase is essential to ensure prompt and efficient SAC silencing. Overall, our findings uncover a mechanism of SAC inactivation required for timely mitotic exit.

  18. Inactivation of Ichthyophonus spores using sodium hypochlorite and polyvinyl pyrrolidone iodine

    Science.gov (United States)

    Hershberger, P.K.; Pacheco, C.A.; Gregg, J.L.

    2008-01-01

    Chlorine and iodine solutions were effective at inactivating Ichthyophonus spores in vitro. Inactivation in sea water increased directly with halogen concentration and exposure duration, with significant differences (P < 0.05) from controls occurring at all chlorine concentrations and exposure durations tested (1.5-13.3 ppm for 1-60 min) and at most iodine concentrations and exposure durations tested (1.2 ppm for 60 min and 5.9-10.7 ppm for 1-60 min). However, 10-fold reductions in spore viability occurred only after exposure to halogen solutions at higher concentrations and/or longer durations (13 ppm total chlorine for 1-60 min, 5.9 ppm total iodine for 60 min, and 10.7 ppm total iodine for 1-60 min). Inactivation efficacy was greater when halogen solutions were prepared in fresh water, presumably because of combined effects of halogen-induced inactivation and general spore instability in fresh water. The results have practical implications for disinfection and biocontainment in research laboratories and other facilities that handle live Ichthyophonus cultures and/or infected fish.

  19. In vitro effects of l-carnitine and glutamine on motility, acrosomal abnormality, and plasma membrane integrity of rabbit sperm during liquid-storage.

    Science.gov (United States)

    Sarıözkan, Serpil; Ozdamar, Saim; Türk, Gaffari; Cantürk, Fazile; Yay, Arzu

    2014-06-01

    This study was designed to evaluate the in vitro effects of l-carnitine and glutamine (Gln) on the sperm quality parameters of liquid-stored rabbit semen maintained up to 24 h at 5°C. Pooled and extended ejaculates were divided into two equal portions. l-Carnitine doses of 0.5, 1 and 2mM were added to the first portion, and glutamine was added at the same doses to the second portion. All samples were cooled to 5°C and examined at 0, 6, 12 and 24 h of liquid storage. Supplementation of the semen extender with three different doses of l-carnitine provided significant increases in the percentage of motile sperm at 12 h (Pl-carnitine significantly (Pl-carnitine and Gln provided a protection for sperm against cool storage-induced functional and structural damages. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. X-chromosome inactivation and escape

    Indian Academy of Sciences (India)

    2015-11-06

    Nov 6, 2015 ... She predicted many of the features of X inactivation, for e.g., .... feature that locks silencing, i.e. DNA methylation at CpG islands of X-linked ..... 1996 XIST RNA paints the inactive X chromosome at interphase: evidence for a novel RNA involved in nuclear/chromosome structure. J. Cell Biol. 132, 259–275.

  1. Bioinactivation: Software for modelling dynamic microbial inactivation.

    Science.gov (United States)

    Garre, Alberto; Fernández, Pablo S; Lindqvist, Roland; Egea, Jose A

    2017-03-01

    This contribution presents the bioinactivation software, which implements functions for the modelling of isothermal and non-isothermal microbial inactivation. This software offers features such as user-friendliness, modelling of dynamic conditions, possibility to choose the fitting algorithm and generation of prediction intervals. The software is offered in two different formats: Bioinactivation core and Bioinactivation SE. Bioinactivation core is a package for the R programming language, which includes features for the generation of predictions and for the fitting of models to inactivation experiments using non-linear regression or a Markov Chain Monte Carlo algorithm (MCMC). The calculations are based on inactivation models common in academia and industry (Bigelow, Peleg, Mafart and Geeraerd). Bioinactivation SE supplies a user-friendly interface to selected functions of Bioinactivation core, namely the model fitting of non-isothermal experiments and the generation of prediction intervals. The capabilities of bioinactivation are presented in this paper through a case study, modelling the non-isothermal inactivation of Bacillus sporothermodurans. This study has provided a full characterization of the response of the bacteria to dynamic temperature conditions, including confidence intervals for the model parameters and a prediction interval of the survivor curve. We conclude that the MCMC algorithm produces a better characterization of the biological uncertainty and variability than non-linear regression. The bioinactivation software can be relevant to the food and pharmaceutical industry, as well as to regulatory agencies, as part of a (quantitative) microbial risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Pulsed electric field inactivation in a microreactor

    NARCIS (Netherlands)

    Fox, M.B.

    2006-01-01

    Pulsed electric fields (PEF) is a novel, non-thermal pasteurization method which uses short, high electric field pulses to inactivate microorganisms. The advantage of a pasteurization method like PEF compared to regular heat pasteurization is that the taste, flavour, texture and nutritional value

  3. Inactivation of human norovirus using chemical sanitizers

    Science.gov (United States)

    The porcine gastric mucin binding magnetic bead (PGM-MB) assay was used to evaluate the ability of chlorine, chlorine dioxide, peroxyacetic acid, hydrogen peroxide, and trisodium phosphate to inactivate human norovirus within 10 percent stool filtrate. One min free chlorine treatments at concentrat...

  4. Inactivation of prion infectivity by ionizing rays

    Energy Technology Data Exchange (ETDEWEB)

    Gominet, M. [Ionisos, ZI les Chatinieres, F01120 Dagneux (France); Vadrot, C.; Austruy, G. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France); Darbord, J.C. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France)], E-mail: darbord@pharmacie.univ-paris5.fr

    2007-11-15

    Inactivation of prion deposits on medical devices or prion contamination in pharmaceutical raw materials is considered as impossible by using gamma irradiation. Early, the guideline WHO/CDS/CSR/APH/2000 has described irradiation as an ineffective process. But, in 2003, S. Miekka et al. noted radiation inactivation of prions in a particular application to purify human albumin, shown by the physical denaturation of the infectious protein (PrP). The aim of our study was to determine the inactivation of prions with a scrapie model (strain C506M3) by irradiating standardised preparations. Results: Gamma irradiation was partially effective, showing a 4-5 log reduction on exposure to 50 kGy. A characteristic effect-dose curve was not observed (25, 50 and 100 kGy), only an increase in the incubation period of the murine disease (229 days with 25 kGy to 290 days with 100 kGy) compared with 170 days without irradiation. Since the inactivation was not a total one, the observed effect is significant. It is proposed that further work be undertaken with the model to investigate the application of gamma radiation known levels of prion contamination.

  5. Safety of snake antivenom immunoglobulins: efficacy of viral inactivation in a complete downstream process.

    Science.gov (United States)

    Caricati, C P; Oliveira-Nascimento, L; Yoshida, J T; Caricati, A T P; Raw, I; Stephano, M A

    2013-01-01

    Viral safety remains a challenge when processing a plasma-derived product. A variety of pathogens might be present in the starting material, which requires a downstream process capable of broad viral reduction. In this article, we used a wide panel of viruses to assess viral removal/inactivation of our downstream process for Snake Antivenom Immunoglobulin (SAI). First, we screened and excluded equine plasma that cross-reacted with any model virus, a procedure not published before for antivenoms. In addition, we evaluated for the first time the virucidal capacity of phenol applied to SAI products. Among the steps analyzed in the process, phenol addition was the most effective one, followed by heat, caprylic acid, and pepsin. All viruses were fully inactivated only by phenol treatment; heat, the second most effective step, did not inactivate the rotavirus and the adenovirus used. We therefore present a SAI downstream method that is cost-effective and eliminates viruses to the extent required by WHO for a safe product. © 2013 American Institute of Chemical Engineers.

  6. Battling Bacterial Biofilms with Gas Discharge Plasma

    Science.gov (United States)

    Zelaya, Anna; Vandervoort, Kurt; Brelles-Mariño, Graciela

    Most studies dealing with growth and physiology of bacteria have been carried out using free-living cells. However, most bacteria live in communities referred to as biofilms where cooperative interactions among their members make conventional methods of controlling microbial growth often ineffective. The use of gas discharge plasmas represents an alternative to traditional decontamination/sterilization methods. We studied biofilms using two organisms, Chromobacterium violaceum and Pseudomonas aeruginosa. With the first organism we demonstrated almost complete loss of cell culturability after a 5-min plasma treatment. However, additional determinations showed that non-culturable cells were still alive after short exposure times. We have recently reported the effect of plasma on P. aeruginosa biofilms grown on borosilicate coupons. In this paper, we present results for plasma treatments of 1-, 3-, and 7-day old P. aeruginosa biofilms grown on polycarbonate or stainless-steel coupons. Results indicate nearly 100% of ­biofilm inactivation after 5 min of exposure with similar inactivation kinetics for 1-, 3-, and 7-day-old biofilms, and for both materials used. The inactivation kinetics is similar for both organisms, suggesting that the method is useful regardless of the type of biofilm. AFM images show changes in biofilm structure for various plasma exposure times.

  7. Inactivation of Escherichia coli by citral.

    Science.gov (United States)

    Somolinos, M; García, D; Condón, S; Mackey, B; Pagán, R

    2010-06-01

    The aim was to evaluate (i) the resistance of Escherichia coli BJ4 to citral in a buffer system as a function of citral concentration, treatment medium pH, storage time and initial inoculum size, (ii) the role of the sigma factor RpoS on citral resistance of E. coli, (iii) the role of the cell envelope damage in the mechanism of microbial inactivation by citral and (iiii) possible synergistic effects of mild heat treatment and pulsed electric fields (PEF) treatment combined with citral. The initial inoculum size greatly affected the efficacy of citral against E. coli cells. Exposure to 200 microl l(-1) of citral at pH 4.0 for 24 h at 20 degrees C caused the inactivation of more than 5 log(10) cycles of cells starting at an inoculum size of 10(6) or 10(7) CFU ml(-1), whereas increasing the cell concentration to 10(9) CFU ml(-1) caused citral at pH 4.0 than pH 7.0. The rpoS null mutant strain E. coli BJ4L1 was less resistant to citral than the wild-type strain. Occurrence of sublethal injury to both the cytoplasmic and outer membranes was demonstrated by adding sodium chloride or bile salts to the recovery media. The majority of sublethally injured cells by citral required energy and lipid synthesis for repair. A strongly synergistic lethal effect was shown by mild heat treatment combined with citral but the presence of citral during the application of a PEF treatment did not show any advantage. This work confirms that cell envelope damage is an important event in citral inactivation of bacteria, and it describes the key factors on the inactivation of E. coli cells by citral. Knowledge about the mechanism of microbial inactivation by citral helps establish successful combined preservation treatments.

  8. The Recombinant Maize Ribosome-Inactivating Protein Transiently Reduces Viral Load in SHIV89.6 Infected Chinese Rhesus Macaques

    Directory of Open Access Journals (Sweden)

    Rui-Rui Wang

    2015-01-01

    Full Text Available Ribosome inactivating proteins (RIPs inhibit protein synthesis by depurinating the large ribosomal RNA and some are found to possess anti-human immunodeficiency virus (HIV activity. Maize ribosome inactivating protein (RIP has an internal inactivation loop which is proteolytically removed for full catalytic activity. Here, we showed that the recombinant active maize RIP protected chimeric simian-human immunodeficiency virus (SHIV 89.6-infected macaque peripheral blood mononuclear cells from lysis ex vivo and transiently reduced plasma viral load in SHIV89.6-infected rhesus macaque model. No evidence of immune dysregulation and other obvious side-effects was found in the treated macaques. Our work demonstrates the potential development of maize RIP as an anti-HIV agent without impeding systemic immune functions.

  9. Role of FAAH-like anandamide transporter in anandamide inactivation.

    Directory of Open Access Journals (Sweden)

    Kwannok Leung

    Full Text Available The endocannabinoid system modulates numerous physiological processes including nociception and reproduction. Anandamide (AEA is an endocannabinoid that is inactivated by cellular uptake followed by intracellular hydrolysis by fatty acid amide hydrolase (FAAH. Recently, FAAH-like anandamide transporter (FLAT, a truncated and catalytically-inactive variant of FAAH, was proposed to function as an intracellular AEA carrier and mediate its delivery to FAAH for hydrolysis. Pharmacological inhibition of FLAT potentiated AEA signaling and produced antinociceptive effects. Given that endocannabinoids produce analgesia through central and peripheral mechanisms, the goal of the current work was to examine the expression of FLAT in the central and peripheral nervous systems. In contrast to the original report characterizing FLAT, expression of FLAT was not observed in any of the tissues examined. To investigate the role of FLAT as a putative AEA binding protein, FLAT was generated from FAAH using polymerase chain reaction and further analyzed. Despite its low cellular expression, FLAT displayed residual catalytic activity that was sensitive to FAAH inhibitors and abolished following mutation of its catalytic serine. Overexpression of FLAT potentiated AEA cellular uptake and this appeared to be dependent upon its catalytic activity. Immunofluorescence revealed that FLAT localizes primarily to intracellular membranes and does not contact the plasma membrane, suggesting that its capability to potentiate AEA uptake may stem from its enzymatic rather than transport activity. Collectively, our data demonstrate that FLAT does not serve as a global intracellular AEA carrier, although a role in mediating localized AEA inactivation in mammalian tissues cannot be ruled out.

  10. Radiation inactivation target size of rat adipocyte glucose transporter

    Energy Technology Data Exchange (ETDEWEB)

    Jung, C.Y.; Jacobs, D.B.; Berenski, C.J.; Spangler, R.A.

    1987-05-01

    In situ assembly states of rat adipocyte glucose transport protein in plasma membrane (PM) and in microsomal pool (MM) were assessed by measuring target size (TS) of D glucose-sensitive, cytochalasin B binding activity. High energy radiation inactivated the binding in both PM and MM by reducing the total capacity of the binding (B/sub T/) without affecting the dissociation constant (K/sub D/). The reduction in B/sub T/ as a function of radiation dose was analyzed based on classical target theory, from which TS was calculated. TS in the PM of insulin-treated adipocytes was 58 KDa. TS in the MM of noninsulin-treated and insulin-treated adipocytes were 112 and 109 KDa, respectively. With MM, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses showing a shoulder in the semilog plots, which may be due to an interaction with a radiation sensitive inhibitor. With these results, they propose the following model: Adipocyte glucose transporter, while exists as a monomer (T) in PM, occurs in MM either as a homodimer (T/sub 2/) or as a heterodimer (TX) with a protein X of a similar size. These dimers (T/sub 2/ or TX) in MM, furthermore, may form a multi-molecular assembly with another, large (300-400 KDa) protein Y, and insulin increases this assembly formation. These putative, transporter-associated proteins X and Y may play an important role in control of transporter distribution between PM and MM, particularly in response to insulin.

  11. Eradication of Pseudomonas aeruginosa biofilms by atmospheric pressure non-thermal plasma.

    Directory of Open Access Journals (Sweden)

    Mahmoud Y Alkawareek

    Full Text Available Bacteria exist, in most environments, as complex, organised communities of sessile cells embedded within a matrix of self-produced, hydrated extracellular polymeric substances known as biofilms. Bacterial biofilms represent a ubiquitous and predominant cause of both chronic infections and infections associated with the use of indwelling medical devices such as catheters and prostheses. Such infections typically exhibit significantly enhanced tolerance to antimicrobial, biocidal and immunological challenge. This renders them difficult, sometimes impossible, to treat using conventional chemotherapeutic agents. Effective alternative approaches for prevention and eradication of biofilm associated chronic and device-associated infections are therefore urgently required. Atmospheric pressure non-thermal plasmas are gaining increasing attention as a potential approach for the eradication and control of bacterial infection and contamination. To date, however, the majority of studies have been conducted with reference to planktonic bacteria and rather less attention has been directed towards bacteria in the biofilm mode of growth. In this study, the activity of a kilohertz-driven atmospheric pressure non-thermal plasma jet, operated in a helium oxygen mixture, against Pseudomonas aeruginosa in vitro biofilms was evaluated. Pseudomonas aeruginosa biofilms exhibit marked susceptibility to exposure of the plasma jet effluent, following even relatively short (≈ 10's s exposure times. Manipulation of plasma operating conditions, for example, plasma operating frequency, had a significant effect on the bacterial inactivation rate. Survival curves exhibit a rapid decline in the number of surviving cells in the first 60 seconds followed by slower rate of cell number reduction. Excellent anti-biofilm activity of the plasma jet was also demonstrated by both confocal scanning laser microscopy and metabolism of the tetrazolium salt, XTT, a measure of bactericidal

  12. Effects of Bacterial Inactivation Methods on Downstream Proteomic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Andy; Merkley, Eric D.; Clowers, Brian H.; Hutchison, Janine R.; Kreuzer, Helen W.

    2015-05-01

    Inactivation of pathogenic microbial samples is often necessary for the protection of researchers and to comply with local and federal regulations. By its nature, biological inactivation causes changes to microbial samples, potentially affecting observed experimental results. While inactivation induced damage to materials such as DNA has been evaluated, the effect of various inactivation strategies on proteomic data, to our knowledge, has not been discussed. To this end, we inactivated samples of Yersinia pestis and Escherichia coli by autoclave, ethanol, or irradiation treatment to determine how inactivation changes liquid chromatography tandem mass spectrometry data quality as well as apparent protein content of cells. Proteomic datasets obtained from aliquots of samples inactivated by different methods were highly similar, with Pearson correlation coefficients ranging from 0.822 to 0.985 and 0.816 to 0.985 for E. coli and Y. pestis, respectively, suggesting that inactivation had only slight impacts on the set of proteins identified. In addition, spectral quality metrics such as distributions of various database search algorithm scores remained constant across inactivation methods, indicating that inactivation does not appreciably degrade spectral quality. Though overall changes resulting from inactivation were small, there were detectable trends. For example, one-sided Fischer exact tests determined that periplasmic proteins decrease in observed abundance after sample inactivation by autoclaving (α = 1.71x10-2 for E. coli, α = 4.97x10-4 for Y. pestis) and irradiation (α = 9.43x10-7 for E. coli, α = 1.21x10-5 for Y. pestis) when compared to controls that were not inactivated. Based on our data, if sample inactivation is necessary, we recommend inactivation with ethanol treatment with secondary preference given to irradiation.

  13. Seemingly neutral polymorphic variants may confer immunity to splicing-inactivating mutations

    DEFF Research Database (Denmark)

    Nielsen, Karsten Bork; Sørensen, Suzette; Cartegni, Luca

    2007-01-01

    The idea that point mutations in exons may affect splicing is intriguing and adds an additional layer of complexity when evaluating their possible effects. Even in the best-studied examples, the molecular mechanisms are not fully understood. Here, we use patient cells, model minigenes, and in vitro...... assays to show that a missense mutation in exon 5 of the medium-chain acyl-CoA dehydrogenase (MCAD) gene primarily causes exon skipping by inactivating a crucial exonic splicing enhancer (ESE), thus leading to loss of a functional protein and to MCAD deficiency. This ESE functions by antagonizing...... a juxtaposed exonic splicing silencer (ESS) and is necessary to define a suboptimal 3' splice site. Remarkably, a synonymous polymorphic variation in MCAD exon 5 inactivates the ESS, and, although this has no effect on splicing by itself, it makes splicing immune to deleterious mutations in the ESE...

  14. Assessment of immunogenic potential of Vero adapted formalin inactivated vaccine derived from novel ECSA genotype of Chikungunya virus.

    Science.gov (United States)

    Tiwari, Mugdha; Parida, Manmohan; Santhosh, S R; Khan, Mohsin; Dash, Paban Kumar; Rao, P V Lakshmana

    2009-04-21

    The recent resurgence of Chikungunya virus (CHIKV) in India and Indian Ocean Islands with unusual clinical severity is a matter of great public health concern. Despite the fact that CHIKV resurgence is associated with epidemic of unprecedented magnitude, no approved licensed vaccine is currently available. In the present study, a Vero cell adapted purified formalin inactivated prototype vaccine candidate was prepared using a current Indian strain implicated with the explosive epidemic during 2006. The bulk preparation of the vaccine candidate was undertaken in microcarrier based spinner culture using cytodex-1 in virus production serum free medium. The inactivation of the virus was accomplished through standard formalin inactivation protocol. The mice were immunized subcutaneously with alhydrogel gel formulation of inactivated virus preparation. The assessment of both humoral and cell-mediated immune response was accomplished through ELISA, plaque reduction neutralization test (PRNT), microcytotoxicity assay and cytokine production assay. The results revealed that formalin inactivated vaccine candidate induced both high titered ELISA (1:51,200) and plaque reduction neutralizing antibodies (1:6400) with peak antibody titer being observed during 6 -- 8 weeks of post-vaccination. In the absence of suitable murine challenge model, the protective efficacy was established by both in vitro and in vivo neutralization tests. Further assessment of cellular immunity through in vitro stimulation of spleenocytes from immunized mice revealed augmentation of high levels of both pro- and anti-inflammatory cytokines, indicating a mixed balance of Th1 and Th2 response. These findings suggest that the formalin inactivated Chikungunya vaccine candidate reported in this study has very good immunogenic potential to neutralize the virus infectivity by augmenting both humoral and cell-mediated immune response.

  15. Influence of resuscitation fluids, fresh frozen plasma and antifibrinolytics on fibrinolysis in a thrombelastography-based, in-vitro, whole-blood model.

    Science.gov (United States)

    Kostousov, Vadim; Wang, Yao-Wei W; Cotton, Bryan A; Wade, Charles E; Holcomb, John B; Matijevic, Nena

    2013-07-01

    Hyperfibrinolysis has been identified as a mechanism of trauma coagulopathy associated with poor outcome. The aim of the study was to create a trauma coagulopathy model (TCM) with a hyperfibrinolysis thrombelastography (TEG) pattern similar to injured patients and test the effects of different resuscitation fluids and antifibrinolytics on fibrinolysis. TCM was established from whole blood by either 15% dilution with isotonic saline, lactated Ringer's, Plasma-Lyte, 5% albumin, Voluven, Hextend, 6% dextran in isotonic saline or 30% dilution with lactated Ringer's plus Voluven and supplementation with tissue factor and tissue plasminogen activator (tPA). These combinations resulted in a TCM that could then be 'treated' with tranexamic acid (TXA) or 6-aminocaproic acid (ACA). Clot formation was evaluated by TEG. Whole-blood dilution by 15% with crystalloids and albumin in the presence of tissue factor plus tPA resulted in an abnormal TEG pattern and increased fibrinolysis, as did dilution with synthetic colloids. TXA 1 μg/ml or ACA 10 μg/ml were sufficient to suppress fibrinolysis when TCM was diluted 15% with lactated Ringer's, but 3 μg/ml of TXA or 30 μg/ml of ACA were needed for fibrinolysis inhibition induced by simultaneous euvolemic dilution with lactated Ringer's plus Voluven by 30%. A total of 15% dilution of whole blood in the presence of tissue factor plus tPA results in a hyperfibrinolysis TEG pattern similar to that observed in severely injured patients. Synthetic colloids worsen TEG variables with a further increase of fibrinolysis. Low concentrations of TXA or ACA reversed hyperfibrinolysis, but the efficient concentrations were dependent on the degree of fibrinolysis and whole-blood dilution.

  16. Controlled release of moxifloxacin from intraocular lenses modified by Ar plasma-assisted grafting with AMPS or SBMA: An in vitro study.

    Science.gov (United States)

    Pimenta, A F R; Vieira, A P; Colaço, R; Saramago, B; Gil, M H; Coimbra, P; Alves, P; Bozukova, D; Correia, T R; Correia, I J; Guiomar, A J; Serro, A P

    2017-08-01

    Intraocular lenses (IOLs) present an alternative for extended, local drug delivery in the prevention of post-operative acute endophthalmitis. In the present work, we modified the surface of a hydrophilic acrylic material, used for manufacturing of IOLs, through plasma-assisted grafting copolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), with the aim of achieving a controlled and effective drug release. The material was loaded with moxifloxacin (MFX), a commonly used antibiotic for endophthalmitis prevention. The characterization of the modified material showed that relevant properties, like swelling capacity, wettability, refractive index and transmittance, were not affected by the surface modification. Concerning the drug release profiles, the most promising result was obtained when AMPS grafting was done in the presence of MFX. This modification led to a higher amount of drug being released for a longer period of time, which is a requirement for the prevention of endophthalmitis. The material was found to be non-cytotoxic for rabbit corneal endothelial cells. In a second step, prototype IOLs were modified with AMPS and loaded with MFX as previously and, after sterilization and storage (30days), they were tested under dynamic conditions, in a microfluidic cell with volume and renovation rate similar to the eye aqueous humour. MFX solutions collected in this assay were tested against Staphylococcus aureus and Staphylococcus epidermidis and the released antibiotic proved to be effective against both bacteria until the 12th day of release. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Inactivation of a Norovirus by High-Pressure Processing▿

    Science.gov (United States)

    Kingsley, David H.; Holliman, Daniel R.; Calci, Kevin R.; Chen, Haiqiang; Flick, George J.

    2007-01-01

    Murine norovirus (strain MNV-1), a propagable norovirus, was evaluated for susceptibility to high-pressure processing. Experiments with virus stocks in Dulbecco's modified Eagle medium demonstrated that at room temperature (20°C) the virus was inactivated over a pressure range of 350 to 450 MPa, with a 5-min, 450-MPa treatment being sufficient to inactivate 6.85 log10 PFU of MNV-1. The inactivation of MNV-1 was enhanced when pressure was applied at an initial temperature of 5°C; a 5-min pressure treatment of 350 MPa at 30°C inactivated 1.15 log10 PFU of virus, while the same treatment at 5°C resulted in a reduction of 5.56 log10 PFU. Evaluation of virus inactivation as a function of treatment times ranging from 0 to 150 s and 0 to 900 s at 5°C and 20°C, respectively, indicated that a decreasing rate of inactivation with time was consistent with Weibull or log-logistic inactivation kinetics. The inactivation of MNV-1 directly within oyster tissues was demonstrated; a 5-min, 400-MPa treatment at 5°C was sufficient to inactivate 4.05 log10 PFU. This work is the first demonstration that norovirus can be inactivated by high pressure and suggests good prospects for inactivation of nonpropagable human norovirus strains in foods. PMID:17142353

  18. An In Vitro Investigation of Platelet-Rich Plasma-Gel as a Cell and Growth Factor Delivery Vehicle for Tissue Engineering.

    Science.gov (United States)

    Jalowiec, Jagoda M; D'Este, Matteo; Bara, Jennifer Jane; Denom, Jessica; Menzel, Ursula; Alini, Mauro; Verrier, Sophie; Herrmann, Marietta

    2016-01-01

    Platelet-rich plasma (PRP) has been used for different applications in human and veterinary medicine. Many studies have shown promising therapeutic effects of PRP; however, there are still many controversies regarding its composition, properties, and clinical efficacy. The aim of this study was to evaluate the influence of different platelet concentrations on the rheological properties and growth factor (GF) release profile of PRP-gels. In addition, the viability of incorporated bone marrow-derived human mesenchymal stem cells (MSCs) was investigated. PRP (containing 1000 × 10(3), 2000 × 10(3), and 10,000 × 10(3) platelets/μL) was prepared from human platelet concentrates. Platelet activation and gelification were achieved by addition of human thrombin. Viscoelastic properties of PRP-gels were evaluated by rheological studies. The release of GFs and inflammatory proteins was measured using a membrane-based protein array and enzyme-linked immunosorbent assay. MSC viability and proliferation in PRP-gels were assessed over 7 days by cell viability staining. Cell proliferation was examined using DNA quantification. Regardless of the platelet content, all tested PRP-gels showed effective cross-linking. A positive correlation between protein release and the platelet concentration was observed at all time points. Among the detected proteins, the chemokine CCL5 was the most abundant. The greatest release appeared within the first 4 h after gelification. MSCs could be successfully cultured in PRP-gels over 7 days, with the highest cell viability and DNA content found in PRP-gels with 1000 × 10(3) platelets/μL. The results of this study suggest that PRP-gels represent a suitable carrier for both cell and GF delivery for tissue engineering. Notably, a platelet concentration of 1000 × 10(3) platelets/μL appeared to provide the most favorable environment for MSCs. Thus, the platelet concentration is an important consideration for the clinical

  19. Plasma harmonics

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    Preface; Why plasma harmonics? A very brief introduction Early stage of plasma harmonic studies - hopes and frustrations New developments in plasma harmonics studies: first successes Improvements of plasma harmonics; Theoretical basics of plasma harmonics; Basics of HHG Harmonic generation in fullerenes using few-cycle pulsesVarious approaches for description of observed peculiarities of resonant enhancement of a single harmonic in laser plasmaTwo-colour pump resonance-induced enhancement of odd and even harmonics from a tin plasmaCalculations of single harmonic generation from Mn plasma;Low-o

  20. Cathepsin D inactivates cysteine proteinase inhibitors, cystatins.

    Science.gov (United States)

    Lenarcic, B; Kos, J; Dolenc, I; Lucovnik, P; Krizaj, I; Turk, V

    1988-07-29

    The formation of inactive complexes in excess molar amounts of human cathepsins H and L with their protein inhibitors human stefin A, human stefin B and chicken cystatin at pH 5.6 has been shown by measurement of enzyme activity coupled with reverse-phase HPLC not to involve covalent cleavage of the inhibitors. Inhibition must be the direct result of binding. On the contrary the interaction of cystatins with aspartic proteinase cathepsin D at pH 3.5 for 60 min followed by HPLC resulted in their inactivation accompanied by peptide bond cleavage at several sites, preferentially those involving hydrophobic amino acid residues. The released peptides do not inhibit papain and cathepsin L. These results explain reported elevated levels of cysteine proteinases and lead to the proposal that cathepsin D exerts an important function, through inactivation of cystatins, in the increased activities of cysteine proteinases in human diseases including muscular distrophy.

  1. Female meiotic sex chromosome inactivation in chicken.

    Directory of Open Access Journals (Sweden)

    Sam Schoenmakers

    2009-05-01

    Full Text Available During meiotic prophase in male mammals, the heterologous X and Y chromosomes remain largely unsynapsed, and meiotic sex chromosome inactivation (MSCI leads to formation of the transcriptionally silenced XY body. In birds, the heterogametic sex is female, carrying Z and W chromosomes (ZW, whereas males have the homogametic ZZ constitution. During chicken oogenesis, the heterologous ZW pair reaches a state of complete heterologous synapsis, and this might enable maintenance of transcription of Z- and W chromosomal genes during meiotic prophase. Herein, we show that the ZW pair is transiently silenced, from early pachytene to early diplotene using immunocytochemistry and gene expression analyses. We propose that ZW inactivation is most likely achieved via spreading of heterochromatin from the W on the Z chromosome. Also, persistent meiotic DNA double-strand breaks (DSBs may contribute to silencing of Z. Surprisingly, gammaH2AX, a marker of DSBs, and also the earliest histone modification that is associated with XY body formation in mammalian and marsupial spermatocytes, does not cover the ZW during the synapsed stage. However, when the ZW pair starts to desynapse, a second wave of gammaH2AX accumulates on the unsynapsed regions of Z, which also show a reappearance of the DSB repair protein RAD51. This indicates that repair of meiotic DSBs on the heterologous part of Z is postponed until late pachytene/diplotene, possibly to avoid recombination with regions on the heterologously synapsed W chromosome. Two days after entering diplotene, the Z looses gammaH2AX and shows reactivation. This is the first report of meiotic sex chromosome inactivation in a species with female heterogamety, providing evidence that this mechanism is not specific to spermatogenesis. It also indicates the presence of an evolutionary force that drives meiotic sex chromosome inactivation independent of the final achievement of synapsis.

  2. Chlorine Inactivation of Spores of Encephalitozoon spp.

    OpenAIRE

    Johnson, C. H.; Marshall, M. M.; DeMaria, L. A.; Moffet, J. M.; Korich, D. G.

    2003-01-01

    This report is an extension of a preliminary investigation on the use of chlorine to inactivate spores of Encephalitozoon intestinalis and to investigate the effect of chlorine on two other species, E cuniculi and E. hellem, associated with human infection. The 50% tissue culture infective doses of these three species were also determined. On the basis of the results obtained, it appears that chlorination of water is an effective means of controlling spores of these organisms in the aquatic e...

  3. Rapid inactivation of SARS-like coronaviruses.

    Energy Technology Data Exchange (ETDEWEB)

    Kapil, Sanjay (Kansas State University, Manhattan, KS); Oberst, R. D. (Kansas State University, Manhattan, KS); Bieker, Jill Marie; Tucker, Mark David; Souza, Caroline Ann; Williams, Cecelia Victoria

    2004-03-01

    Chemical disinfection and inactivation of viruses is largely understudied, but is very important especially in the case of highly infectious viruses. The purpose of this LDRD was to determine the efficacy of the Sandia National Laboratories developed decontamination formulations against Bovine Coronavirus (BCV) as a surrogate for the coronavirus that causes Severe Acute Respiratory Syndrome (SARS) in humans. The outbreak of SARS in late 2002 resulted from a highly infectious virus that was able to survive and remain infectious for extended periods. For this study, preliminary testing with Escherichia coli MS-2 (MS-2) and Escherichia coli T4 (T4) bacteriophages was conducted to develop virucidal methodology for verifying the inactivation after treatment with the test formulations following AOAC germicidal methodologies. After the determination of various experimental parameters (i.e. exposure, concentration) of the formulations, final testing was conducted on BCV. All experiments were conducted with various organic challenges (horse serum, bovine feces, compost) for results that more accurately represent field use condition. The MS-2 and T4 were slightly more resistant than BCV and required a 2 minute exposure while BCV was completely inactivated after a 1 minute exposure. These results were also consistent for the testing conducted in the presence of the various organic challenges indicating that the test formulations are highly effective for real world application.

  4. Deactivation of Enterococcus Faecalis Bacteria by an Atmospheric Cold Plasma Brush

    Science.gov (United States)

    Chen, Wei; Huang, Jun; Du, Ning; Liu, Xiao-Di; Lv, Guo-Hua; Wang, Xing-Quan; Zhang, Guo-Ping; Guo, Li-Hong; Yang, Si-Ze

    2012-07-01

    An atmospheric cold plasma brush suitable for large area and low-temperature plasma-based sterilization is designed and used to treat enterococcus faecalis bacteria. The results show that the efficiency of the inactivation process by helium plasma is dependent on applied power and exposure time. After plasma treatments, the cell structure and morphology changes can be observed by scanning electron microscopy. Optical emission measurements indicate that reactive species such as O and OH play a significant role in the sterilization process.

  5. Inactivation of TSE agents: safety of blood and blood-derived products.

    Science.gov (United States)

    Taylor, D M

    2003-02-01

    Evidence relating to whether the blood of individuals with sporadic Creutzfeldt-Jakob disease is infectious is discussed. The conclusion is that this is unproven. Similar consideration is given to the blood of individuals with variant Creutzfeldt-Jakob disease; it is concluded that there is no convincing evidence that the blood is infectious but reasons for caution are presented. There is discussion regarding factors that add to the safety of plasma-derived therapeutic products, including the capacity of the manufacturing processes to inactivate or remove infectivity by the chemical and physical processes involved. There is extended discussion regarding the inactivation of these types of agents and the few reliable options available in worst-case scenarios such as the processing of instruments used neurosurgically on known or suspected cases. The most effective method is exposure to 1 M sodium hydroxide during autoclaving at 121 degrees C. The inappropriateness of applying any of the most effective methods to blood and blood-products because they are harsh and denaturing is discussed. Nevertheless, such procedures have potential application to the plant used in the manufacture of plasma-products. Evidence is presented which suggests that even more modest treatments (the use of lower concentrations of sodium hydroxide at lower temperatures) are effective when applied to surfaces that are free from any tissue contamination, as is the case with plant used to manufacture plasma-derived products. This evidence has come from studies carried out by the gelatin manufacturers of Europe regarding the capability of their manufacturing systems to inactivate the causal agent of bovine spongiform encephalopathy.

  6. Normalization of serum calcium by cinacalcet in a patient with hypercalcaemia due to a de novo inactivating mutation of the calcium-sensing receptor.

    NARCIS (Netherlands)

    Timmers, H.J.L.M.; Karperien, M.; Hamdy, N.A.; Boer, H. de; Hermus, A.R.M.M.

    2006-01-01

    Familial benign hypocalciuric hypercalcaemia (FHH) results from a heterozygous inactivating mutation of the calcium-sensing receptor (CaR) and is characterized by hypercalcaemia, hypocalciuria and inappropriately normal plasma levels of parathyroid hormone. In a minority of patients, a loss of

  7. AVALIAÇÃO IN VITRO DO SÊMEN CAPRINO RESFRIADO, COM OU SEM CENTRIFUGAÇÃO DO PLASMA SEMINAL E DILUÍDO EM LEITE DESNATADO-GLICOSE E TRIS-GEMA DE OVO

    Directory of Open Access Journals (Sweden)

    Thereza Cristina Calmon de Bittencourt

    2006-10-01

    Full Text Available O objetivo deste trabalho foi comparar in vitro quatro tratamentos para o resfriamento de sêmen caprino, a partir de 32 ejaculados de quatro bodes, submetidos aos diluidores tris-gema de ovo e leite desnatado-glicose, e processados com ou sem centrifugação do plasma seminal. O sêmen foi resfriado e conservado a 4º C durante 48 horas.Os resultados foram expressos em média e desvio padrão e submetidos a ANOVA (P<0,05 para a análise estatística (SPSS – versão 11.0. Nas amostras leite desnatado-glicose sem (T1 e com (T2 centrifugação e tris-gema de ovo sem (T3 e com (T4 centrifugação, após 48 horas de resfriamento,obtiveram-se as médias de 33,00; 30,68; 40,62 e 46,78 para motilidade (% e de 2,23; 2,34; 2,65 e 3,25 para vigor (0-5.Quanto às patologias de acrossoma (% e de cauda (%,após 48 horas de conservação a 4º C, obtiveram-se as seguintes médias: 5,16; 5,94; 3,81; 4,47 e 16,25; 12,38; 15,34;11,47, respectivamente, para as amostras T1, T2, T3 e T4. Os diferentes tratamentos não alteraram o pH (p>0,05. Conclui-se que o diluidor tris-gema de ovo preservou melhor(p<0,05 a motilidade, o vigor e a patologia de acrossoma, do que o leite desnatado-glicose. A remoção do plasma seminal, por sua vez, não influenciou (p>0,05 as características seminais avaliadas, exceto em relação à patologia de cauda. PALAVRAS-CHAVE: Caprino, centrifugação, diluidor, resfriamento, sêmen.

  8. Perfluorooctanesulfonate Mediates Renal Tubular Cell Apoptosis through PPARgamma Inactivation.

    Directory of Open Access Journals (Sweden)

    Li-Li Wen

    Full Text Available Perfluorinated chemicals (PFCs are ubiquitously distributed in the environments including stainless pan-coating, raincoat, fire extinguisher, and semiconductor products. The PPAR family has been shown to contribute to the toxic effects of PFCs in thymus, immune and excretory systems. Herein, we demonstrated that perfluorooctanesulfonate (PFOS caused cell apoptosis through increasing ratio of Bcl-xS/xL, cytosolic cytochrome C, and caspase 3 activation in renal tubular cells (RTCs. In addition, PFOS increased transcription of inflammatory cytokines (i.e., TNFα, ICAM1, and MCP1 by NFκB activation. Conversely, PFOS reduced the mRNA levels of antioxidative enzymes, such as glutathione peroxidase, catalase, and superoxide dismutase, as a result of reduced PPARγ transactivational activity by using reporter and chromatin immuoprecipitation (ChIP assays. PFOS reduced the protein interaction between PPARγ and PPARγ coactivator-1 alpha (PGC1α by PPARγ deacetylation through Sirt1 upregulation, of which the binding of PPARγ and PGC1α to a peroxisome proliferator response element (PPRE in the promoter regions of these antioxidative enzymes was alleviated in the ChIP assay. Furthermore, Sirt1 also deacetylated p53 and then increased the binding of p53 to Bax, resulting in increased cytosolic cytochrome C. The effect of PPARγ inactivation by PFOS was validated using the PPARγ antagonist GW9662, whereas the adverse effects of PFOS were prevented by PPARγ overexpression and activators, rosiglitozone and L-carnitine, in RTCs. The in vitro finding of protective effect of L-carnitine was substantiated in vivo using Balb/c mice model subjected to PFOS challenge. Altogether, we provide in vivo and in vitro evidence for the protective mechanism of L-carnitine in eliminating PFOS-mediated renal injury, at least partially, through PPARγ activation.

  9. Chlorine inactivation of Tubifex tubifex in drinking water and the synergistic effect of sequential inactivation with UV irradiation and chlorine.

    Science.gov (United States)

    Nie, Xiao-Bao; Li, Zhi-Hong; Long, Yuan-Nan; He, Pan-Pan; Xu, Chao

    2017-06-01

    The inactivation of Tubifex tubifex is important to prevent contamination of drinking water. Chlorine is a widely-used disinfectant and the key factor in the inactivation of T. tubifex. This study investigated the inactivation kinetics of chlorine on T. tubifex and the synergistic effect of the sequential use of chlorine and UV irradiation. The experimental results indicated that the Ct (concentration × timereaction) concept could be used to evaluate the inactivation kinetics of T. tubifex with chlorine, thus allowing for the use of a simpler Ct approach for the assessment of T. tubifex chlorine inactivation requirements. The inactivation kinetics of T. tubifex by chlorine was found to be well-fitted to a delayed pseudo first-order Chick-Watson expression. Sequential experiments revealed that UV irradiation and chlorine worked synergistically to effectively inactivate T. tubifex as a result of the decreased activation energy, Ea, induced by primary UV irradiation. Furthermore, the inactivation effectiveness of T. tubifex by chlorine was found to be affected by several drinking water quality parameters including pH, turbidity, and chemical oxygen demand with potassium permanganate (CODMn) concentration. High pH exhibited pronounced inactivation effectiveness and the decrease in turbidity and CODMn concentrations contributed to the inactivation of T. tubifex. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Rapid in vitro tests to determine the toxicity of raw wastewater and ...

    African Journals Online (AJOL)

    2012-09-18

    Sep 18, 2012 ... Chemosphere 51 539–543. KENDIG D and TARLOFF J (2007) Inactivation of lactate dehydro- genase by several chemicals: Implications for in vitro toxicology studies. Toxicol. In Vitro 21 125–132. KIRBY M, MORRIS S, HURST M, KIRBY S, NEALL P, TYLOR T and FAGG A (2000) The use of cholinesterase ...

  11. Cold Atmospheric Plasma Technology for Decontamination of Space Equipment

    Science.gov (United States)

    Thomas, Hubertus; Rettberg, Petra; Shimizu, Tetsuji; Thoma, Markus; Morfill, Gregor; Zimmermann, Julia; Müller, Meike; Semenov, Igor

    2016-07-01

    Cold atmospheric plasma (CAP) technology is very fast and effective in inactivation of all kinds of pathogens. It is used in hygiene and especially in medicine, since the plasma treatment can be applied to sensitive surfaces, like skin, too. In a first study to use CAP for the decontamination of space equipment we could show its potential as a quite promising alternative to the standard "dry heat" and H2O2 methods [Shimizu et al. Planetary and Space Science, 90, 60-71. (2014)]. In a follow-on study we continue the investigations to reach high application level of the technology. First, we redesign the actual setup to a plasma-gas circulation system, increasing the effectivity of inactivation and the sustainability. Additionally, we want to learn more about the plasma chemistry processes involved in the inactivation. Therefore, we perform detailed plasma and gas measurements and compare them to numerical simulations. The latter will finally be used to scale the decontamination system to sizes useful also for larger space equipment. Typical materials relevant for space equipment will be tested and investigated on surface material changes due to the plasma treatment. Additionally, it is planned to use electronic boards and compare their functionality before and after the CAP expose. We will give an overview on the status of the plasma decontamination project funded by the Bavarian Ministry of Economics.

  12. X-chromosomal inactivation directly influences the phenotypic manifestation of X-linked protoporphyria.

    Science.gov (United States)

    Brancaleoni, V; Balwani, M; Granata, F; Graziadei, G; Missineo, P; Fiorentino, V; Fustinoni, S; Cappellini, M D; Naik, H; Desnick, R J; Di Pierro, E

    2016-01-01

    X-linked protoporphyria (XLP), a rare erythropoietic porphyria, results from terminal exon gain-of-function mutations in the ALAS2 gene causing increased ALAS2 activity and markedly increased erythrocyte protoporphyrin levels. Patients present with severe cutaneous photosensitivity and may develop liver dysfunction. XLP was originally reported as X-linked dominant with 100% penetrance in males and females. We characterized 11 heterozygous females from six unrelated XLP families and show markedly varying phenotypic and biochemical heterogeneity, reflecting the degree of X-chromosomal inactivation of the mutant gene. ALAS2 sequencing identified the specific mutation and confirmed heterozygosity among the females. Clinical history, plasma and erythrocyte protoporphyrin levels were determined. Methylation assays of the androgen receptor and zinc-finger MYM type 3 short tandem repeat polymorphisms estimated each heterozygotes X-chromosomal inactivation pattern. Heterozygotes with equal or increased skewing, favoring expression of the wild-type allele had no clinical symptoms and only slightly increased erythrocyte protoporphyrin concentrations and/or frequency of protoporphyrin-containing peripheral blood fluorocytes. When the wild-type allele was preferentially inactivated, heterozygous females manifested the disease phenotype and had both higher erythrocyte protoporphyrin levels and circulating fluorocytes. These findings confirm that the previous dominant classification of XLP is inappropriate and genetically misleading, as the disorder is more appropriately designated XLP. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. The role of chemical sputtering during plasma sterilization of Bacillus atrophaeus

    Energy Technology Data Exchange (ETDEWEB)

    Opretzka, J [Center for Plasma Science and Technology, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Benedikt, J [Center for Plasma Science and Technology, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Awakowicz, P [Center for Plasma Science and Technology, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Wunderlich, J [Fraunhofer Institut for Process Engineering and Packaging, Giggenhauser Strasse 35, 85354 Freising (Germany); Keudell, A von [Center for Plasma Science and Technology, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)

    2007-05-07

    The inactivation of bacteria by plasma discharges offers the unique benefits of short treatment times, minimal damage to the objects being sterilized and minimal use of hazardous chemicals. Plasmas produce reactive fluxes of ions, atoms and UV photons from any given precursor gas and are expected to be a viable method for such sterilization applications. The plasma based inactivation of harmful biological systems is, however, not yet widely used, because any validation is hampered by the limited knowledge about the interaction mechanisms at the interface between a plasma and a biological system. By using quantified beams of hydrogen atoms, argon ions and UV photons, the treatment of bacteria in a typical argon-hydrogen plasma is mimicked in a very controlled manner. As an example the inactivation of endospores of Bacillus atrophaeus is studied. It is shown that the impact of H atoms alone causes no inactivation of bacteria. Instead, the simultaneous impact of atoms and low energy ions causes a perforation of the endosporic shell. The same process occurs during plasma treatment and explains the efficient inactivation of bacteria.

  14. The role of chemical sputtering during plasma sterilization of Bacillus atrophaeus

    Science.gov (United States)

    Opretzka, J.; Benedikt, J.; Awakowicz, P.; Wunderlich, J.; von Keudell, A.

    2007-05-01

    The inactivation of bacteria by plasma discharges offers the unique benefits of short treatment times, minimal damage to the objects being sterilized and minimal use of hazardous chemicals. Plasmas produce reactive fluxes of ions, atoms and UV photons from any given precursor gas and are expected to be a viable method for such sterilization applications. The plasma based inactivation of harmful biological systems is, however, not yet widely used, because any validation is hampered by the limited knowledge about the interaction mechanisms at the interface between a plasma and a biological system. By using quantified beams of hydrogen atoms, argon ions and UV photons, the treatment of bacteria in a typical argon-hydrogen plasma is mimicked in a very controlled manner. As an example the inactivation of endospores of Bacillus atrophaeus is studied. It is shown that the impact of H atoms alone causes no inactivation of bacteria. Instead, the simultaneous impact of atoms and low energy ions causes a perforation of the endosporic shell. The same process occurs during plasma treatment and explains the efficient inactivation of bacteria.

  15. Linking plasma kinetics to plasma-bio interactions

    Science.gov (United States)

    Bruggeman, Peter

    2015-05-01

    Cold non-equilibrium atmospheric pressure plasmas have received a lot of attention in the last decade due to their huge potential for biomedical applications. In my group, we have characterized an RF driven APPJ in great detail. The characterization includes electrical measurements, imaging, optical emission spectroscopy, (two photon enhanced) laser induced fluorescence, Thomson scattering, Rayleigh scattering, Raman scattering and mass spectrometry. This led to a detailed knowledge of the electron density, electron temperature, gas temperature, NO, O, OH, O3 densities, ionic species and air concentrations in the plasma effluent. Living organisms for in vitro studies are typically kept in complex solutions or culture media. Plasma-bio interactions involves not only the production of reactive species in the plasma gas phase but also transport to the liquid phase and plasma induced liquid phase chemistry and its impact on the living organisms. Reactive nitrogen and oxygen species have been identified as the key reactive species. Recent results of my group show that controlling the gas phase plasma chemistry can lead to significant different biological responses of the living organisms corresponding to different chemical pathways. The effect of plasma jet interaction with liquids containing mammalian cells, bacteria and virus will be discussed. The outcomes of these studies allow unraveling chemical pathways responsible for plasma-bio interactions and linking plasma kinetics to plasma-bio interactions.

  16. X Inactivation and Progenitor Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ruben Agrelo

    2011-04-01

    Full Text Available In mammals, silencing of one of the two X chromosomes is necessary to achieve dosage compensation. The 17 kb non-coding RNA called Xist triggers X inactivation. Gene silencing by Xist can only be achieved in certain contexts such as in cells of the early embryo and in certain hematopoietic progenitors where silencing factors are present. Moreover, these epigenetic contexts are maintained in cancer progenitors in which SATB1 has been identified as a factor related to Xist-mediated chromosome silencing.

  17. Modeling the pressure inactivation dynamics of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Yamamoto K.

    2005-01-01

    Full Text Available Escherichia coli, as a model microorganism, was treated in phosphate-buffered saline under high hydrostatic pressure between 100 and 300 MPa, and the inactivation dynamics was investigated from the viewpoint of predictive microbiology. Inactivation data were curve fitted by typical predictive models: logistic, Gompertz and Weibull functions. Weibull function described the inactivation curve the best. Two parameters of Weibull function were calculated for each holding pressure and their dependence on holding pressure was obtained by interpolation. With the interpolated parameters, inactivation curves were simulated and compared with the experimental data sets.

  18. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  19. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  20. Inactivation of Candida glabrata by a humid DC argon discharge afterglow: dominant contributions of short-lived aqueous active species

    Science.gov (United States)

    Xiong, Qing; Liu, Hongbin; Lu, Weiping; Chen, Qiang; Xu, Le; Wang, Xia; Zhu, Qunlin; Zeng, Xue; Yi, Ping

    2017-05-01

    Plasma medicine applications are currently attracting significant interest all over the world. Bactericidal treatments of Candida glabrata cultured in saline suspension are performed in this study by a room-temperature reactive afterglow of a DC-driven argon discharge. Water vapor was added to the discharge to study the inactivation contributions of reactive hydrolytic species including OH and H2O2 transporting along the gas flow to the treated solutions. The inactivation results indicate that the dominant roles in the bactericidal treatments are played by the short-lived aqueous active species, but not the stable species like H2O2aq (aq indicates an aqueous species). Further analysis shows that the ·OHaq radicals play an important role in the inactivation process. The ·OHaq radicals in the suspension are mostly produced from the direct dissolution of the OH species in the reactive afterglow. With the increase of added water vapor content, the ·OHaq production increases and enhances the inactivation efficiency of C. glabrata. Furthermore, it is found that the ambient air diffusion shows essential effects on the bactericidal activity of the remote humid argon discharge. Higher bactericidal effects can be obtained in open-space treatments compared to in a controlled Ar + H2O gas atmosphere. Key active air-byproduct species are believed to be generated in the suspension during the treatments and contributing to the inactivation process. Based on chemical analysis, the peroxynitrous acid ONOOHaq is considered as the key antimicrobial air-byproduct species. These results indicate the important dependence of plasma biomedical effects on the processing environment, which finally relates to the critical contributions of the key reactive species formed therein.

  1. Treatment of Streptococcus mutans bacteria by a plasma needle

    Science.gov (United States)

    Zhang, Xianhui; Huang, Jun; Liu, Xiaodi; Peng, Lei; Guo, Lihong; Lv, Guohua; Chen, Wei; Feng, Kecheng; Yang, Si-ze

    2009-03-01

    A dielectric barrier discharge plasma needle was realized at atmospheric pressure with a funnel-shaped nozzle. The preliminary characteristics of the plasma plume and its applications in the inactivation of Streptococcus mutans (S. mutans), the most important microorganism causing dental caries, were presented in this paper. The temperature of the plasma plume does not reach higher than 315 K when the power is below 28 W. Oxygen was injected downstream in the plasma afterglow region through the powered steel tube. Its effect was studied via optical-emission spectroscopy, both in air and in agar. Results show that addition of 26 SCCM O2 does not affect the plume length significantly (SCCM denotes cubic centimeter per minute at STP). The inactivation of S. mutans is primarily attributed to ultraviolet light emission, O, OH, and He radicals.

  2. Inactivation of Template-Directed Misfolding of Infectious Prion Protein by Ozone

    Science.gov (United States)

    Ding, Ning; Price, Luke M.; Braithwaite, Shannon L.; Balachandran, Aru; Belosevic, Miodrag

    2012-01-01

    Misfolded prions (PrPSc) are well known for their resistance to conventional decontamination processes. The potential risk of contamination of the water environment, as a result of disposal of specified risk materials (SRM), has raised public concerns. Ozone is commonly utilized in the water industry for inactivation of microbial contaminants and was tested in this study for its ability to inactivate prions (263K hamster scrapie = PrPSc). Treatment variables included initial ozone dose (7.6 to 25.7 mg/liter), contact time (5 s and 5 min), temperature (4°C and 20°C), and pH (pH 4.4, 6.0, and 8.0). Exposure of dilute suspensions of the infected 263K hamster brain homogenates (IBH) (0.01%) to ozone resulted in the in vitro destruction of the templating properties of PrPSc, as measured by the protein misfolding cyclic amplification (PMCA) assay. The highest levels of prion inactivation (≥4 log10) were observed with ozone doses of 13.0 mg/liter, at pH 4.4 and 20°C, resulting in a CT (the product of residual ozone concentration and contact time) value as low as 0.59 mg · liter−1 min. A comparison of ozone CT requirements among various pathogens suggests that prions are more susceptible to ozone degradation than some model bacteria and protozoa and that ozone treatment may be an effective solution for inactivating prions in water and wastewater. PMID:22138993

  3. Synthesis and characterization of PLGA nanoparticles containing mixture of curcuminoids for optimization of photodynamic inactivation

    Science.gov (United States)

    Suzuki, Isabella L.; Inada, Natália M.; Marangoni, Valéria S.; Corrêa, Thaila Q.; Zucolotto, Valtencir; Kurachi, Cristina; Bagnato, Vanderlei S.

    2016-03-01

    Because of excessive use of antibiotics there is a growth in the number of resistant strains. Due to this growth of multiresistant bacteria, the number of searches looking for alternatives antibacterial therapeutic has increased, and among them is the antimicrobial photodynamic therapy (aPDT) or photodynamic inactivation (PDI). The photodynamic inactivation involves the action of a photosensitizer (PS), activated by a specific wavelength, in the present of oxygen, resulting in cytotoxic effect. Natural curcumin, consists of a mixture of three curcuminoids: curcumin, demethoxycurcumin and bis-demethoxycurcumin. Curcumin has various pharmacological properties, however, has extremely low solubility in aqueous solutions, which difficult the use as therapeutic agent. The present study aims to develop polymeric PLGA nanoparticles containing curcuminoids to improve water solubility, increase bioavailability providing protection from degradation (chemistry and physics), and to verify the efficacy in photodynamic inactivation of microorganisms. The PLGA-CURC were synthesized by nanoprecipitation, resulting in two different systems, with an average size of 172 nm and 70% encapsulation efficiency for PLGA-CURC1, and 215 nm and 80% for PLGA-CURC2. Stability tests showed the polymer protected the curcuminoids against premature degradation. Microbiological tests in vitro with curcuminoids water solution and both suspension of PLGA-CURC were efficient in Gram-positive bacterium and fungus. However, the solution presented dark toxicity at high concentrations, unlike the nanoparticles. Thus, it was concluded that it was possible to let curcuminoids water soluble by encapsulation in PLGA nanoparticles, to ensure improved stability in aqueous medium (storage), and to inactivate bacteria and fungus.

  4. Bim nuclear translocation and inactivation by viral interferon regulatory factor.

    Directory of Open Access Journals (Sweden)

    Young Bong Choi

    2010-08-01

    Full Text Available Viral replication efficiency is in large part governed by the ability of viruses to counteract pro-apoptotic signals induced by infection of the host cell. Human herpesvirus 8 (HHV-8 uses several strategies to block the host's innate antiviral defenses via interference with interferon and apoptotic signaling. Contributors include the four viral interferon regulatory factors (vIRFs 1-4, which function in dominant negative fashion to block cellular IRF activities in addition to targeting IRF signaling-induced proteins such as p53 and inhibiting other inducers of apoptosis such as TGFbeta receptor-activated Smad transcription factors. Here we identify direct targeting by vIRF-1 of BH3-only pro-apoptotic Bcl-2 family member Bim, a key negative regulator of HHV-8 replication, to effect its inactivation via nuclear translocation. vIRF-1-mediated relocalization of Bim was identified in transfected cells, by both immunofluorescence assay and western analysis of fractionated cell extracts. Also, co-localization of vIRF-1 and Bim was detected in nuclei of lytically infected endothelial cells. In vitro co-precipitation assays using purified vIRF-1 and Bim revealed direct interaction between the proteins, and Bim-binding residues of vIRF-1 were mapped by deletion and point mutagenesis. Generation and experimental utilization of Bim-refractory vIRF-1 variants revealed the importance of vIRF-1:Bim interaction, specifically, in pro-replication and anti-apoptotic activity of vIRF-1. Furthermore, blocking of the interaction with cell-permeable peptide corresponding to the Bim-binding region of vIRF-1 confirmed the relevance of vIRF-1:Bim association to vIRF-1 pro-replication activity. To our knowledge, this is the first report of an IRF protein that interacts with a Bcl-2 family member and of nuclear sequestration of Bim or any other member of the family as a means of inactivation. The data presented reveal a novel mechanism utilized by a virus to control

  5. Efficacy of select disinfectants at inactivating Ranavirus.

    Science.gov (United States)

    Bryan, Laura K; Baldwin, Charles A; Gray, Matthew J; Miller, Debra L

    2009-04-06

    Ranavirus can cause disease in reptiles and amphibians. Because survival time outside of a host remains uncertain, equipment must be disinfected to prevent transmission of ranaviruses. However, disinfectant efficacy against amphibian ranaviruses has not been investigated for chlorhexidine (Nolvasan), sodium hypochlorite (bleach), or potassium compounds. Our goal was to determine the efficacy of Nolvasan (0.25, 0.75 and 2.0%), bleach (0.2, 1.0, 3.0 and 5.0%), and Virkon S (1.0%) at inactivating Ranavirus at 1 and 5 min contact durations. Potassium permanganate (KMnO4) (2.0 and 5.0 ppm) was also tested with a 60 min contact time. Nolvasan at 0.75 and 2.0% and bleach at 3.0 and 5.0% concentration were effective for both contact durations. Virkon S was effective for both durations, but KMnO4 was not effective at either concentration. Concentrations of Nolvasan, bleach and Virkon S that are at least 0.75, 3.0 and 1.0%, respectively, are effective at inactivating Ranavirus after 1 min exposure time.

  6. X-changing information on X inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Barakat, Tahsin Stefan; Jonkers, Iris; Monkhorst, Kim [Department of Reproduction and Development, Room Ee 09-71, Erasmus MC, PO Box 2040, 3000 CA Rotterdam (Netherlands); Gribnau, Joost, E-mail: j.gribnau@erasmusmc.nl [Department of Reproduction and Development, Room Ee 09-71, Erasmus MC, PO Box 2040, 3000 CA Rotterdam (Netherlands)

    2010-03-10

    In female somatic cells of mammalian species one X chromosome is inactivated to ensure dosage equality of X-encoded genes between females and males, during development and adulthood. X chromosome inactivation (XCI) involves various epigenetic mechanisms, including RNA mediated gene silencing in cis, DNA methylation, and changes in chromatin modifications and composition. XCI therefore provides an attractive paradigm to study epigenetic gene regulation in a more general context. The XCI process starts with counting of the number of X chromosomes present in a nucleus, and initiation of XCI follows if this number exceeds one per diploid genome. Recently, X-encoded RNF12 has been identified as a dose-dependent activator of XCI. In addition, other factors, including the pluripotency factors OCT4, SOX2 and Nanog, have been implicated to play a role in suppression of initiation of XCI. In this review, we highlight and explain these new and old findings in the context of a stochastic model for X chromosome counting and XCI initiation.

  7. Cold Plasma: an emerging antimicrobial intervention to improve food safety

    Science.gov (United States)

    Contamination of fresh and fresh-cut fruits and vegetables by foodborne pathogens has prompted research into novel interventions. Cold plasma is a nonthermal food processing technology which uses energetic, reactive gases to inactivate contaminating microbes. This flexible sanitizing method uses ele...

  8. Inactivation of single-chain urokinase-type plasminogen activator by thrombin in human subjects.

    Science.gov (United States)

    Braat, E A; Levi, M; Bos, R; Haverkate, F; Lassen, M R; de Maat, M P; Rijken, D C

    1999-08-01

    Thrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a virtually inactive two-chain form (tcu-PA/T), a process that may protect a blood clot from early fibrinolysis. It is not known under what circumstances tcu-PA/T can be generated in vivo. We have studied the occurrence of tcu-PA/T in human subjects with a varying degree of hypercoagulability. tcu-PA/T was assessed in the plasma of patients with disseminated intravascular coagulation (DIC), endotoxin-treated volunteers, patients with unstable angina pectoris, and patients selected for hip replacement. Relationships between tcu-PA/T and several markers reflecting thrombin generation were examined. tcu-PA/T was observed only in the plasma of patients with DIC and was associated with all thrombin markers and with scu-PA and urokinase antigen. Prothrombin fragment 1 + 2 and urokinase antigen were independent predictors of tcu-PA/T. The fact that tcu-PA/T could not be detected in the other three groups was explained by a lower extent of thrombin generation, a greater inhibition of thrombin by antithrombin, or less available urokinase antigen in these groups. The contribution of scu-PA to total urokinase antigen was decreased in the patients with DIC because of inactivation by thrombin, which may be an additional explanation for the inadequate fibrinolysis observed in these patients. These findings show that scu-PA can be inactivated in the circulation under severe pathophysiologic circumstances and that the process of inactivation depends not only on the generation of thrombin but also on the control of thrombin activity by its inhibitor antithrombin.

  9. IL-15 enhances cross-reactive antibody recall responses to seasonal H3 influenza viruses in vitro [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Junqiong Huang

    2017-11-01

    Full Text Available Background: Recently, several human monoclonal antibodies that target conserved epitopes on the stalk region of influenza hemagglutinin (HA have shown broad reactivity to influenza A subtypes. Also, vaccination with recombinant chimeric HA or stem fragments from H3 influenza viruses induce broad immune protection in mice and humans. However, it is unclear whether stalk-binding antibodies can be induced in human memory B cells by seasonal H3N2 viruses. Methods: In this study, we recruited 13 donors previously exposed to H3 viruses, the majority (12 of 13 of which had been immunized with seasonal influenza vaccines. We evaluated plasma baseline strain-specific and stalk-reactive anti-HA antibodies and B cell recall responses to inactivated H3N2 A/Victoria/361/2011 virus in vitro using a high throughput multiplex (mPlex-Flu assay. Results: Stalk-reactive IgG was detected in the plasma of 7 of the subjects. Inactivated H3 viral particles rapidly induced clade cross-reactive antibodies in B cell cultures derived from all 13 donors. In addition, H3 stalk-reactive antibodies were detected in culture supernatants from 7 of the 13 donors (53.8%.  H3 stalk-reactive antibodies were also induced by H1 and H7 subtypes. Interestingly, broadly cross-reactive antibody recall responses to H3 strains were also enhanced by stimulating B cells in vitro with CpG2006 ODN in the presence of IL-15. H3 stalk-reactive antibodies were detected in  CpG2006 ODN + IL-15 stimulated B cell cultures derived from 12 of the 13 donors (92.3%, with high levels detected in cultures from 7 of the 13 donors. Conclusions: Our results demonstrate that stalk-reactive antibody recall responses induced by seasonal H3 viruses and CpG2006 ODN can be enhanced by IL-15.

  10. [Polyphenolic antioxidants efficiently protect urease from inactivation by ultrasonic cavitation].

    Science.gov (United States)

    Metelitsa, D I; Tarun, E I; Losev, Iu P

    2002-01-01

    Inactivation of urease (25 nM) in aqueous solutions (pH 5.0-6.0) treated with low-frequency ultrasound (LFUS; 27 kHz, 60 Wt/cm2, 36-56 degrees C) or high-frequency ultrasound (HFUS; 2.64 MHz, 1 Wt/cm2, 36 or 56 degrees C) has been characterized quantitatively, using first-order rate constants: kin, aggregate inactivation; kin*, thermal inactivation; and kin* (US), ultrasonic inactivation. Within the range from 1 nM to 10 microM, propyl gallate (PG) decreases approximately threefold the rate of LFUS-induced inactivation of urease (56 degrees C), whereas resorcinol poly-2-disulfide prevents this process at 1 nM or higher concentrations. PG completely inhibits HFUS-induced inactivation of urease at 1 nM (36 degrees C) or 10 nM (56 degrees C). At 0.2-10 microM, human serum albumin (HSA) increases the resistance of urease (at 56 degrees C) treated with HFUS to temperature- and cavitation-induced inactivation. Complexes of gallic acid polydisulfide (GAPDS) with HSA (GAPDS-HSA), formed by conjugation of 1.0 nM PGDS with 0.33 nM HSA, prevent HFUS-induced urease inactivation (56 degrees C).

  11. Scale down of the inactivated polio vaccine production process

    NARCIS (Netherlands)

    Thomassen, Y.E.; Oever, van 't R.; Vinke, C.M.; Spiekstra, A.; Wijffels, R.H.; Pol, van der L.A.; Bakker, W.A.M.

    2013-01-01

    The anticipated increase in the demand for inactivated polio vaccines resulting from the success in the polio eradication program requires an increase in production capacity and cost price reduction of the current inactivated polio vaccine production processes. Improvement of existing production

  12. Suicide inactivation of horseradish peroxidase by excess hydrogen ...

    African Journals Online (AJOL)

    In reactions carried out in sodium acetate buffer, higher inactivation rates were observed when the buffer ion concentration was increased, an indication that peroxidase might be generating reactive radicals from the buffer molecules. Promethazine exerted a modest protective effect against inactivation; however, higher ...

  13. Effects of electrolytes on virus inactivation by acidic solutions.

    Science.gov (United States)

    Nishide, Mitsunori; Tsujimoto, Kazuko; Uozaki, Misao; Ikeda, Keiko; Yamasaki, Hisashi; Koyama, A Hajime; Arakawa, Tsutomu

    2011-06-01

    Acidic pH is frequently used to inactivate viruses. We have previously shown that arginine synergizes with low pH in enhancing virus inactivation. Considering a potential application of the acid inactivation of viruses for the prevention and treatment of superficial virus infection at body surfaces and fixtures, herein we have examined the effects of various electrolytes on the acid-induced inactivation of the herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), the influenza A virus (IAV) and the poliovirus upon their incubation at 30˚C for 5 min. Eight electrolytes, i.e., phosphate, NaCl, glutamate, aspartate, pyrrolidone carboxylate, citrate, malate and acetate were tested. No detectable inactivation of the poliovirus was observed under the conditions examined, reflecting its acid-resistance. HSV-1 and HSV-2 responded similarly to the acid-treatment and electrolytes. Some electrolytes showed a stronger virus inactivation than others at a given pH and concentration. The effects of the electrolytes were virus-dependent, as IAV responded differently from HSV-1 and HSV-2 to these electrolytes, indicating that certain combinations of the electrolytes and a low pH can exert a more effective virus inactivation than other combinations and that their effects are virus-specific. These results should be useful in designing acidic solvents for the inactivation of viruses at various surfaces.

  14. Ebola Virus Inactivation by Detergents Is Annulled in Serum

    NARCIS (Netherlands)

    van Kampen, Jeroen J. A.; Tintu, Andrei; Russcher, Henk; Fraaij, Pieter L. A.; Reusken, Chantal B. E. M.; Rijken, Mikel; van Hellemond, Jaap J.; van Genderen, Perry J. J.; Koelewijn, Rob; de Jong, Menno D.; Haddock, Elaine; Fischer, Robert J.; Munster, Vincent J.; Koopmans, Marion P. G.

    2017-01-01

    Treatment of blood samples from hemorrhagic fever virus (HFV)-infected patients with 0.1% detergents has been recommended for virus inactivation and subsequent safe laboratory testing. However, data on virus inactivation by this procedure are lacking. Here we show the effect of this procedure on

  15. EDITORIAL: Focus on Plasma Medicine

    Science.gov (United States)

    Morfill, G. E.; Kong, M. G.; Zimmermann, J. L.

    2009-11-01

    'Plasma Healthcare' is an emerging interdisciplinary research topic of rapidly growing importance, exploring considerable opportunities at the interface of plasma physics, chemistry and engineering with life sciences. Some of the scientific discoveries reported so far have already demonstrated clear benefits for healthcare in areas of medicine, food safety, environmental hygiene, and cosmetics. Examples include ongoing studies of prion inactivation, chronic wound treatment and plasma-mediated cancer therapy. Current research ranges from basic physical processes, plasma chemical design, to the interaction of plasmas with (i) eukaryotic (mammalian) cells; (ii) prokaryotic (bacteria) cells, viruses, spores and fungi; (iii) DNA, lipids, proteins and cell membranes; and (iv) living human, animal and plant tissues in the presence of biofluids. Of diverse interests in this new field is the need for hospital disinfection, in particular with respect to the alarming increase in bacterial resistance to antibiotics, the concomitant needs in private practices, nursing homes etc, the applications in personal hygiene—and the enticing possibility to 'design' plasmas as possible pharmaceutical products, employing ionic as well as molecular agents for medical treatment. The 'delivery' of the reactive plasma agents occurs at the gaseous level, which means that there is no need for a carrier medium and access to the treatment surface is optimal. This focus issue provides a close look at the current state of the art in Plasma Medicine with a number of forefront research articles as well as an introductory review. Focus on Plasma Medicine Contents Application of epifluorescence scanning for monitoring the efficacy of protein removal by RF gas-plasma decontamination Helen C Baxter, Patricia R Richardson, Gaynor A Campbell, Valeri I Kovalev, Robert Maier, James S Barton, Anita C Jones, Greg DeLarge, Mark Casey and Robert L Baxter Inactivation factors of spore-forming bacteria using low

  16. Chlorophyll mediated photodynamic inactivation of blue laser on Streptococcus mutans

    Science.gov (United States)

    Astuti, Suryani Dyah; Zaidan, A.; Setiawati, Ernie Maduratna; Suhariningsih

    2016-03-01

    Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm2. The results show that exposure to laser with energy dose of 7.18 J/cm2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

  17. Kinetic modelling of enzyme inactivation : kinetics of heat inactivation of the extracellular proteinase from Pseudomonas fluorescens 22F

    NARCIS (Netherlands)

    Schokker, E.P.

    1997-01-01

    The kinetics of heat inactivation of the extracellular proteinase from Pseudomonas fluorescens 22F was studied. It was established, by making use of kinetic modelling, that heat inactivation in the temperature range 35 - 70 °C was most likely caused

  18. Development of thermostable lyophilized inactivated polio vaccine.

    Science.gov (United States)

    Kraan, Heleen; van Herpen, Paul; Kersten, Gideon; Amorij, Jean-Pierre

    2014-10-01

    The aim of current study was to develop a dried inactivated polio vaccine (IPV) formulation with minimal loss during the drying process and improved stability when compared with the conventional liquid IPV. Extensive excipient screening was combined with the use of a Design of Experiment (DoE) approach in order to achieve optimal results with high probability. Although it was shown earlier that the lyophilization of a trivalent IPV while conserving its antigenicity is challenging, we were able to develop a formulation that showed minimal loss of potency during drying and subsequent storage at higher temperatures. This study showed the potential of a highly stable and safe lyophilized polio vaccine, which might be used in developing countries without the need of a cold-chain.

  19. Inactivation of Coxiella burnetti by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, G.H.; McCaul, T.F.; Williams, J.C.

    1989-01-01

    The gamma radiation inactivation kinetics for Coxiella burnetii at - 79 C were exponential. The radiation dose needed to reduce the number of infective C. burnetii by 90% varied from 0-64 to 1.2 kGy depending on the phase of hte micro-organism, purity of the culture and composition of suspending menstruum. The viability of preparations containing C. burnetti was completely abolished by 10 kGy without diminishing antigenicity or ability to elicit a protective immune response in vaccinated mice. Immunocytochemical examinations using monoclonal antibodies and electron microscopy demonstrated that radiation doses of 20 kGy did not alter cell-wall morphology or cell-surface antigenic epitopes.

  20. Inactivation of Coxiella burnetii by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, G.H.; McCaul, T.F. (Army Medical Research Inst. of Infectious Diseases, Fort Detrick, Frederick, MD (USA)); Williams, J.C. (National Inst. of Allergy and Infectious Diseases, Bethesda, MD (USA))

    1989-12-01

    The gamma radiation inactivation kinetics for Coxiella burnetii at - 79{sup 0}C were exponential. The radiation dose needed to reduce the number of infective C. burnetii by 90% varied from 0.64 to 1.2 kGy depending on the phase of the micro-organism, purity of the culture and composition of suspending menstruum. The viability of preparations containing 10{sup 11} C. burnetii ml{sup -1} was completely abolished by 10 kGy without diminishing antigenicity or ability to elicit a protective immune response in vaccinated mice. Immunocytochemical examinations using monoclonal antibodies and electron microscopy demonstrated that radiation doses of 20 kGy did not alter cell-wall morphology or cell-surface antigenic epitopes. (author).

  1. Esterase resistant to inactivation by heavy metals

    KAUST Repository

    El, Dorry Hamza

    2014-09-25

    EstATII is an esterase that a halotolerant, thermophilic and resistant to a spectrum of heavy metals including toxic concentration of metals. It was isolated from the lowest convective layer of the Atlantis II Red Sea brine pool. The Atlantis II brine pool is an extreme environment that possesses multiple harsh conditions such as; high temperature, salinity, pH and high concentration of metals, including toxic heavy metals. A fosmid metagenomic library using DNA isolated from the lowest convective layer this pool was used to identify EstATII. Polynucleotides encoding EstATII and similar esterases are disclosed and can be used to make EstATII. EstATII or compositions or apparatuses that contain it may be used in various processes employing lipases/esterases especially when these processes are performed under harsh conditions that inactivate other kinds of lipases or esterases.

  2. Plasma medicine—current state of research and medical application

    Science.gov (United States)

    Weltmann, K.-D.; von Woedtke, Th

    2017-01-01

    Plasma medicine means the direct application of cold atmospheric plasma (CAP) on or in the human body for therapeutic purposes. Further, the field interacts strongly with results gained for biological decontamination. Experimental research as well as first practical application is realized using two basic principles of CAP sources: dielectric barrier discharges (DBD) and atmospheric pressure plasma jets (APPJ). Originating from the fundamental insights that the biological effects of CAP are most probably caused by changes of the liquid environment of cells, and are dominated by reactive oxygen and nitrogen species (ROS, RNS), basic mechanisms of biological plasma activity are identified. It was demonstrated that there is no increased risk of cold plasma application and, above all, there are no indications for genotoxic effects. The most important biological effects of cold atmospheric pressure plasma were identified: (1) inactivation of a broad spectrum of microorganisms including multidrug resistant ones; (2) stimulation of cell proliferation and tissue regeneration with lower plasma treatment intensity (treatment time); (3) inactivation of cells by initialization of programmed cell death (apoptosis) with higher plasma treatment intensity (treatment time). In recent years, the main focus of clinical applications was in the field of wound healing and treatment of infective skin diseases. First CAP sources are CE-certified as medical devices now which is the main precondition to start the introduction of plasma medicine into clinical reality. Plasma application in dentistry and, above all, CAP use for cancer treatment are becoming more and more important research fields in plasma medicine. A further in-depth knowledge of control and adaptation of plasma parameters and plasma geometries is needed to obtain suitable and reliable plasma sources for the different therapeutic indications and to open up new fields of medical application.

  3. Challenge study of the pathogen reduction capacity of the THERAFLEX MB-Plasma technology.

    Science.gov (United States)

    Reichenberg, S; Gravemann, U; Sumian, C; Seltsam, A

    2015-08-01

    Although most pathogen reduction systems for plasma primarily target viruses, bacterial contamination may also occur. This study aimed to investigate the bacterial reduction capacity of a methylene blue (MB) treatment process and its virus inactivation capacity in lipaemic plasma. Bacterial concentrations in plasma units spiked with different bacterial strains were measured before and after the following steps of the THERAFLEX MB-Plasma procedure: leucocyte filtration, MB/light treatment and MB filtration. Virus inactivation was investigated for three virus types in non-lipaemic, borderline lipaemic and highly lipaemic plasma. Leucocyte filtration alone efficiently eliminated most of the tested bacteria by more than 4 logs (Staphylococcus epidermidis and Staphylococcus aureus) or to the limit of detection (LOD) (≥ 4.8 logs; Escherichia coli, Bacillus cereus and Klebsiella pneumoniae). MB/light and MB filtration further reduced Staphylococcus epidermidis and Staphylococcus aureus to below the LOD. The small bacterium Brevundimonas diminuta was reduced by 1.7 logs by leucocyte filtration alone, and to below the LOD by additional MB/light treatment and MB filtration (≥ 3.7 logs). Suid herpesvirus 1, bovine viral diarrhoea virus and human immunodeficiency virus 1 were efficiently inactivated by THERAFLEX MB-Plasma, independent of the degree of lipaemia. THERAFLEX MB-Plasma efficiently reduces bacteria, mainly via the integrated filtration system. Its virus inactivation capacity is sufficient to compensate for reduced light transparency due to lipaemia. © 2015 International Society of Blood Transfusion.

  4. Human male meiotic sex chromosome inactivation.

    Directory of Open Access Journals (Sweden)

    Marieke de Vries

    Full Text Available In mammalian male gametogenesis the sex chromosomes are distinctive in both gene activity and epigenetic strategy. At first meiotic prophase the heteromorphic X and Y chromosomes are placed in a separate chromatin domain called the XY body. In this process, X,Y chromatin becomes highly phosphorylated at S139 of H2AX leading to the repression of gonosomal genes, a process known as meiotic sex chromosome inactivation (MSCI, which has been studied best in mice. Post-meiotically this repression is largely maintained. Disturbance of MSCI in mice leads to harmful X,Y gene expression, eventuating in spermatocyte death and sperm heterogeneity. Sperm heterogeneity is a characteristic of the human male. For this reason we were interested in the efficiency of MSCI in human primary spermatocytes. We investigated MSCI in pachytene spermatocytes of seven probands: four infertile men and three fertile controls, using direct and indirect in situ methods. A considerable degree of variation in the degree of MSCI was detected, both between and within probands. Moreover, in post-meiotic stages this variation was observed as well, indicating survival of spermatocytes with incompletely inactivated sex chromosomes. Furthermore, we investigated the presence of H3K9me3 posttranslational modifications on the X and Y chromatin. Contrary to constitutive centromeric heterochromatin, this heterochromatin marker did not specifically accumulate on the XY body, with the exception of the heterochromatic part of the Y chromosome. This may reflect the lower degree of MSCI in man compared to mouse. These results point at relaxation of MSCI, which can be explained by genetic changes in sex chromosome composition during evolution and candidates as a mechanism behind human sperm heterogeneity.

  5. X chromosome inactivation in women with alcoholism.

    Science.gov (United States)

    Manzardo, Ann M; Henkhaus, Rebecca; Hidaka, Brandon; Penick, Elizabeth C; Poje, Albert B; Butler, Merlin G

    2012-08-01

    All female mammals with 2 X chromosomes balance gene expression with males having only 1 X by inactivating one of their X chromosomes (X chromosome inactivation [XCI]). Analysis of XCI in females offers the opportunity to investigate both X-linked genetic factors and early embryonic development that may contribute to alcoholism. Increases in the prevalence of skewing of XCI in women with alcoholism could implicate biological risk factors. The pattern of XCI was examined in DNA isolated in blood from 44 adult women meeting DSM-IV criteria for an alcohol use disorder and 45 control women with no known history of alcohol abuse or dependence. XCI status was determined by analyzing digested and undigested polymerase chain reaction (PCR) products of the polymorphic androgen receptor (AR) gene located on the X chromosome. Subjects were categorized into 3 groups based upon the degree of XCI skewness: random (50:50 to 64:36%), moderately skewed (65:35 to 80:20%), and highly skewed (>80:20%). XCI status from informative women with alcoholism was found to be random in 59% (n = 26), moderately skewed in 27% (n = 12), or highly skewed in 14% (n = 6). Control subjects showed 60, 29, and 11%, respectively. The distribution of skewed XCI observed among women with alcoholism did not differ statistically from that of control subjects (χ(2) test = 0.14, 2 df, p = 0.93). Our data did not support an increase in XCI skewness among women with alcoholism or implicate early developmental events associated with embryonic cell loss or unequal (nonrandom) expression of X-linked gene(s) or defects in alcoholism among women. Copyright © 2012 by the Research Society on Alcoholism.

  6. Photocatalytic inactivation of biofilms on bioactive dental adhesives.

    Science.gov (United States)

    Cai, Yanling; Strømme, Maria; Melhus, Asa; Engqvist, Håkan; Welch, Ken

    2014-01-01

    Biofilms are the most prevalent mode of microbial life in nature and are 10-1000 times more resistant to antibiotics than planktonic bacteria. Persistent biofilm growth associated at the margin of a dental restoration often leads to secondary caries, which remains a challenge in restorative dentistry. In this work, we present the first in vitro evaluation of on-demand photocatalytic inactivation of biofilm on a novel dental adhesive containing TiO2 nanoparticles. Streptococcus mutans biofilm was cultured on this photocatalytic surface for 16 h before photocatalytic treatment with ultraviolet-A (UV-A) light. UV-A doses ranging from 3 to 43 J/cm(2) were applied to the surface and the resulting viability of biofilms was evaluated with a metabolic activity assay incorporating phenol red that provided a quantitative measure of the reduction in viability due to the photocatalytic treatments. We show that an UV-A irradiation dose of 8.4 J/cm(2) leads to one order of magnitude reduction in the number of biofilm bacteria on the surface of the dental adhesives while as much as 5-6 orders of magnitude reduction in the corresponding number can be achieved with a dose of 43 J/cm(2). This material maintains its functional properties as an adhesive in restorative dentistry while offering the possibility of a novel dental procedure in the treatment or prevention of bacterial infections via on-demand UV-A irradiation. Similar materials could be developed for the treatment of additional indications such as peri-implantits. Copyright © 2013 Wiley Periodicals, Inc.

  7. Improved immunogenicity of Newcastle disease virus inactivated vaccine following DNA vaccination using Newcastle disease virus hemagglutinin-neuraminidase and fusion protein genes.

    Science.gov (United States)

    Firouzamandi, Masoumeh; Moeini, Hassan; Hosseini, Davood; Bejo, Mohd Hair; Omar, Abdul Rahman; Mehrbod, Parvaneh; Ideris, Aini

    2016-03-01

    The present study describes the development of DNA vaccines using the hemagglutinin-neuraminidase (HN) and fusion (F) genes from AF2240 Newcastle disease virus strain, namely pIRES/HN, pIRES/F and pIRES-F/HN. Transient expression analysis of the constructs in Vero cells revealed the successful expression of gene inserts in vitro. Moreover, in vivo experiments showed that single vaccination with the constructed plasmid DNA (pDNA) followed by a boost with inactivated vaccine induced a significant difference in enzyme-linked immunosorbent assay antibody levels (p inactivated vaccine alone. Taken together, these results indicated that recombinant pDNA could be used to increase the efficacy of the inactivated vaccine immunization procedure.

  8. Cold plasma technology: bactericidal effects on Geobacillus stearothermophilus and Bacillus cereus microorganisms.

    Science.gov (United States)

    Morris, Angela D; McCombs, Gayle B; Akan, Tamer; Hynes, Wayne; Laroussi, Mounir; Tolle, Susan L

    2009-01-01

    Cold plasma, also known as Low Temperature Atmospheric Pressure Plasma (LTAPP) is a novel technology consisting of neutral and charged particles, including free radicals, which can be used to destroy or inactivate microorganisms. Research has been conducted regarding the effect of cold plasma on gram-positive bacteria; however, there is limited research regarding its ability to inactivate the spore-formers Geobacillus stearothermophilus and Bacillus cereus. The purpose of this study was to determine if cold plasma inactivates G. stearothermophilus and B. cereus vegetative cells and spores. Nine hundred eighty-one samples were included in this study (762 experimental and 219 controls). Experimental samples were exposed indirectly or directly to cold plasma, before plating and incubating for 16 hours. Control samples were not exposed to cold plasma. The percentage-kill and cell number reductions were calculated from Colony Forming Units (CFU). Data were statistically analyzed at the .05 level using one-way ANOVA, Kruskal Wallis and Tukey's tests. There was a statistically significant difference in the inactivation of G. stearothermophilus vegetative cells receiving indirect and direct exposure (p=0.0001 and p=0.0013, respectively), as well as for B. cereus vegetative cells and spores (p=0.0001 for direct and indirect). There was no statistically significant difference in the inactivation of G. stearothermophilus spores receiving indirect exposure (p=0.7208) or direct exposure (p=0.0835). Results demonstrate that cold plasma exposure effectively kills G. stearothermophilus vegetative cells and B. cereus vegetative cells and spores; however, G. stearothermophilus spores were not significantly inactivated.

  9. EDITORIAL: Gas plasmas in biology and medicine

    Science.gov (United States)

    Stoffels, Eva

    2006-08-01

    and its attendant complications, such as inflammation and scarring. Another substantial research direction makes use of the bactericidal properties of the plasma. The number of findings on plasma inactivation of bacteria and spores is growing; plasma sterilization has already achieved some commercial success. In future, bacteriostatic properties of cold plasmas will even facilitate non-contact disinfection of human tissues. At this moment, one cannot explicitly list all the medical procedures in which cold plasmas will be involved. My personal intuition predicts widespread use of plasma treatment in dentistry and dermatology, but surely more applications will emerge in the course of this multi-disciplinary research. In fact, some plasma techniques, such as coagulation and coblation, are already used in clinical practice—this is another image of plasma science, which is so far unfamiliar to plasma physicists. Therefore, this particular topic forms a perfect platform for contacts between physicists and medical experts. Our colleagues from the medical scientific community will continue giving us feedback, suggestions or even orders. Biomedical plasmas should not become an isolated research area—we must grow together with medical research, listen to criticism, and eventually serve the physicians. Only then will this new field grow, flourish and bear fruit. All the above-mentioned topics meet in this issue of Journal of Physics D: Applied Physics, comprising the most significant examples of modern biomedical plasma research. Browsing through the contributions, the reader can trace back the progress in this field: from fundamental physical (numerical) studies, through phenomenology and physics of new discharges, studies on plasma-surface modification, bacterial inactivation tests, fundamental cell biological investigations, to final in vivo applications. One may ask why this selection has found its place in a purely physical journal—many contributions are concerned

  10. Two-Dimensional Microdischarge Jet Array in Air: Characterization and Inactivation of Virus

    Science.gov (United States)

    Nayak, Gaurav

    Cold atmospheric pressure plasmas (CAPs) have proven to be quite effective for surface disinfection, wound healing and even cancer treatment in recent years. One of the major societal challenges faced today is related to illness caused by food-borne bacteria and viruses, particularly in minimally processed, fresh or ready-to-eat foods. Gastroenteritis outbreaks, caused, for example, by the human Norovirus (NV) is a growing concern. Current used technologies seem not to be fully effective. In this work we focus on a possible solution based on CAP technology for surface disinfection. Many discharge sources have been studied for disinfection and the two major challenges faced are the use of expensive noble gases (Ar/He) by many plasma sources and the difficulty to scale up the plasma devices. The efficacies of these devices also vary for different plasma sources, making it difficult to compare results from different research groups. Also, the interaction of plasma with the biological matter is not understood well, particularly for virus. In this work, a two-dimensional array of micro dielectric barrier discharge is used to treat Feline Calicivirus (FCV), which is a surrogate for human Norovirus. The plasma source can be operated with an air flow rate (up to 94 standard liters per minute or slm). The use of such discharge source also raises important scientific questions which are addressed in this work. These questions include the effect of gas flow rate on discharge properties and the production of reactive species responsible for virus inactivation and the underlying inactivation mechanism. The plasma source is characterized via several diagnostic techniques such as current voltage measurements for electrical characterization and power measurements, optical emission spectroscopy (OES) to determine the gas temperature, cross-correlation spectroscopy (CCS) for microdischarge evolution and timescales, UV absorption spectroscopy to measure the O3 density, absolute IR

  11. Photodynamic inactivation of microorganisms sensitized by cationic BODIPY derivatives potentiated by potassium iodide.

    Science.gov (United States)

    Reynoso, Eugenia; Quiroga, Ezequiel D; Agazzi, Maximiliano L; Ballatore, María B; Bertolotti, Sonia G; Durantini, Edgardo N

    2017-10-11

    The photodynamic inactivation mediated by 1,3,5,7-tetramethyl-8-[4-(N,N,N-trimethylamino)phenyl]-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 3 and 8-[4-(3-(N,N,N-trimethylamino)propoxy)phenyl]-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 4 was investigated on Staphylococcus aureus, Escherichia coli and Candida albicans. In vitro experiments indicated that BODIPYs 3 and 4 were rapidly bound to microbial cells at short incubation periods. Also, fluorescence microscopy images showed green emission of BODIPYs bound to microbial cells. Photosensitized inactivation improved with an increase of the irradiation time. Similar photoinactivation activities were found for both BODIPYs in bacteria. The photoinactivation induced by these BODIPYs was effective for both bacteria. However, the Gram-positive bacterium was inactivated sooner and with a lower concentration of a photosensitizer than the Gram-negative bacterium. After 15 min irradiation, the complete eradication of S. aureus was obtained with 1 μM photosensitizer. A reduction of 4.5 log in the E. coli viability was found when using 5 μM photosensitizer and 30 min irradiation. Also, the last conditions produced a decrease of 4.5 log in C. albicans cells treated with BODIPY 3, while 4 was poorly effective. On the other hand, the effect of the addition of KI on photoinactivation at different irradiation periods and salt concentrations was investigated. A smaller effect was observed in S. aureus because the photosensitizers alone were already very effective. In E. coli, photokilling potentiation was mainly found at longer irradiation periods. Moreover, the photoinactivation of C. albicans mediated by these BODIPYs was increased in the presence of KI. In solution, an increase in the formation of the BODIPY triplet states was observed with the addition of the salt, due to the effect of external heavy atoms. The greater intersystem crossing together with the formation of reactive iodine species induced by BODIPYs may be

  12. Virus-specific thermostability and heat inactivation profiles of alphaviruses.

    Science.gov (United States)

    Park, So Lee; Huang, Yan-Jang S; Hsu, Wei-Wen; Hettenbach, Susan M; Higgs, Stephen; Vanlandingham, Dana L

    2016-08-01

    Serological diagnosis is a critical component for disease surveillance and is important to address the increase in incidence and disease burden of alphaviruses, such as the chikungunya (CHIKV) and Ross River (RRV) viruses. The gold standard for serological diagnosis is the plaque reduction neutralization test (PRNT), which demonstrates the neutralizing capacity of serum samples after the removal of complement activity and adventitious viruses. This procedure is normally performed following inactivation of the virus at 56°C for 30min. Although this protocol has been widely accepted for the inactivation of envelope RNA viruses, recent studies have demonstrated that prolonged heat inactivation is required to completely inactivate two alphaviruses, Western equine encephalitis virus and CHIKV. Incomplete inactivation of viruses poses a laboratory biosafety risk and can also lead to spurious test results. Despite its importance in ensuring the safety of laboratory personnel as well as test integrity, systematic investigation on the thermostability of alphaviruses has not been performed. In this study, the temperature tolerance and heat inactivation profiles of RRV, Barmah Forest, and o'nyong-nyong viruses were determined. Variations in thermostability were observed within the Semliki forest serocomplex. Therefore, evidence-based heat inactivation procedures for alphaviruses are recommended. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Inactivation of STAT3 Signaling Impairs Hair Cell Differentiation in the Developing Mouse Cochlea

    Directory of Open Access Journals (Sweden)

    Qianqian Chen

    2017-07-01

    Full Text Available Although STAT3 signaling is demonstrated to regulate sensory cell differentiation and regeneration in the zebrafish, its exact role is still unclear in mammalian cochleae. Here, we report that STAT3 and its activated form are specifically expressed in hair cells during mouse cochlear development. Importantly, conditional cochlear deletion of Stat3 leads to an inhibition on hair cell differentiation in mice in vivo and in vitro. By cell fate analysis, inactivation of STAT3 signaling shifts the cell division modes from asymmetric to symmetric divisions from supporting cells. Moreover, inhibition of Notch signaling stimulates STAT3 phosphorylation, and inactivation of STAT3 signaling attenuates production of supernumerary hair cells induced by a Notch pathway inhibitor. Our findings highlight an important role of the STAT3 signaling during mouse cochlear hair cell differentiation and may have clinical implications for the recovery of hair cell loss-induced hearing impairment.

  14. Plasma physics

    CERN Document Server

    Drummond, James E

    2013-01-01

    A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and 70s.Hailed by Science magazine as a ""well executed venture,"" the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwa

  15. Radiation inactivation (target size analysis) of the gonadotropin-releasing hormone receptor: evidence for a high molecular weight complex

    Energy Technology Data Exchange (ETDEWEB)

    Conn, P.M.; Venter, J.C.

    1985-04-01

    In the present study we used radiation inactivation (target size analysis) to measure the functional mol wt of the GnRH receptor while it is still a component of the plasma membrane. This technique is based on the observation that an inverse relationship exists between the dose-dependent inactivation of a macromolecule by ionizing radiation and the size of that macromolecule. This method demonstrates a mol wt of 136,346 +/- 8120 for the GnRH receptor. This estimate is approximately twice that obtained (60,000) by photoaffinity labeling with a radioactive GnRH analog followed by electrophoresis under denaturing conditions and, accordingly, presents the possibility that the functional receptor consists of a high mol wt complex in its native state. The present studies indicate that the GnRH receptor is either a single weight class of protein or several closely related weight classes, such as might occur due to protein glycosylation.

  16. Relative Inactivation by Staphylococcus aureus of Eight Cephalosporin Antibiotics

    Science.gov (United States)

    Fong, Ignatius W.; Engelking, Elin R.; Kirby, William M. M.

    1976-01-01

    These studies extend the recent observation that cefazolin is inactivated to a greater extent than cephaloridine by some strains of penicillinase-producing Staphylococcus aureus, whereas cephalothin undergoes little if any inactivation. In Mueller-Hinton broth (inoculum, 3 × 106) 100 recently isolated strains had minimal inhibitory concentrations (MICs) ≤ 2 μg/ml for cephalothin and cephaloridine, whereas in Trypticase soy broth (TSB) 50% had MICs > 2 μg/ml and 10% (designated “resistant” strains) were >8 μg/ml for cephaloridine but remained ≤2 μg/ml for cephalothin. A large inoculum (3 × 107) of strains with high MICs in TSB almost completely inactivated 50 μg of cefazolin per ml in 6 h, with progressively less inactivation, in the following order, of cephaloridine, cephalexin, cephradine, cephapirin, and cefamandole; cefoxitin and cephalothin underwent little if any inactivation. The greater inactivation in TSB than in Mueller-Hinton broth appeared to be due to a greater production of β-lactamases by each colony-forming unit, since the inoculum size in the two broths was not significantly different. In contrast, “susceptible” strains (MICs ≤ 2 μg/ml in both broths) inactivated cephaloridine more than cefazolin, and equal amounts of powdered bacterial extracts confirmed the fact that qualitatively different β-lactamases were produced by the susceptible and resistant strains. Disk diffusion tests were unreliable in separating the two groups of staphylococci. The clinical significance of inactivation by strains with high MICs is not known but, unless susceptibility can be clearly established, cephalothin appears preferable for severe staphylococcal infections, since it undergoes little if any inactivation by any strains of staphylococci. PMID:938023

  17. Loss of Na+ channel inactivation by anemone toxin (ATX II) mimics the myotonic state in hyperkalaemic periodic paralysis.

    Science.gov (United States)

    Cannon, S C; Corey, D P

    1993-01-01

    1. Mutations that impair inactivation of the sodium channel in skeletal muscle have recently been postulated to cause several heritable forms of myotonia in man. A peptide toxin from Anemonia sulcata (ATX II) selectively disrupts the inactivation mechanism of sodium channels in a way that mimics these mutations. We applied ATX II to rat skeletal muscle to test the hypothesis that myotonia is inducible by altered sodium channel function. 2. Single-channel sodium currents were measured in blebs of surface membrane that arose from the mechanically disrupted fibres. ATX II impaired inactivation as demonstrated by persistent reopenings of sodium channels at strongly depolarized test potentials. A channel failed to inactivate, however, in only a small proportion of the depolarizing steps. With micromolar amounts of ATX II, the ensemble average open probability at the steady state was 0.01-0.02. 3. Ten micromolar ATX II slowed the relaxation of tension after a single twitch by an order of magnitude. Delayed relaxation is the in vitro analogue of the stiffness experienced by patients with myotonia. However, peak twitch force was not affected within the range of 0-10 microM ATX II. 4. Intracellular injection of a long-duration, constant current pulse elicited a train of action potentials in ATX II-treated fibres. After-depolarizations and repetitive firing often persisted beyond the duration of the stimulus. Trains of action potentials varied spontaneously in amplitude and firing frequency in a similar way to the electromyogram of a myotonic muscle. Both the after-depolarization and the post-stimulus firing were abolished by detubulating the fibres with glycerol. 5. We conclude that a loss of sodium channel inactivation alone, without changes in resting membrane conductance, is sufficient to produce the electrical and mechanical features of myotonia. Furthermore, in support of previous studies on myotonic muscle from patients, this model provides direct evidence that only a

  18. Thermoradiation inactivation of naturally occurring organisms in soil

    Science.gov (United States)

    Reynolds, M. C.; Lindell, K. F.; David, T. J.

    1973-01-01

    Samples of soil collected from Kennedy Space Center near spacecraft assembly facilities were found to contain microorganisms very resistant to conventional sterilization techniques. The inactivation behavior of the naturally occurring spores in soil was investigated using dry heat and ionizing radiation, first separately, then in combination. Dry heat inactivation rates of spores were determined for 105 and 125 C. Radiation inactivation rates were determined for dose rates of 660 and 76 krad/hr at 25 C. Simultaneous combinations of heat and radiation were then investigated at 105, 110, 115, 120, and 125 C. Combined treatment was found to be highly synergistic requiring greatly reduced radiation doses to accomplish sterilization.

  19. Biocompatibility of plasma nanostructured biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Slepičková Kasálková, N. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Bačáková, L. [Institute of Physiology, Academy of Sciences of the Czech Republic 142 20 Prague (Czech Republic); Sajdl, P. [Department of Power Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

    2013-07-15

    Many areas of medicine such as tissue engineering requires not only mastery of modification techniques but also thorough knowledge of the interaction of cells with solid state substrates. Plasma treatment can be used to effective modification, nanostructuring and therefore can significantly change properties of materials. In this work the biocompatibility of the plasma nanostructured biopolymers substrates was studied. Changes in surface chemical structure were studied by X-ray photoelectron spectroscopy (XPS). The morphology pristine and modified samples were determined using atomic force microscopy (AFM). The surface wettability was determined by goniometry from contact angle. Biocompatibility was determined by in vitro tests, the rat vascular smooth muscle cells (VSMCs) were cultivated on the pristine and plasma modified biopolymer substrates. Their adhesion, proliferation, spreading and homogeneous distribution on polymers was monitored. It was found that the plasma treatment leads to rapid decrease of contact angle for all samples. Contact angle decreased with increasing time of modification. XPS measurements showed that plasma treatment leads to changes in ratio of polar and non-polar groups. Plasma modification was accompanied by a change of surface morphology. Biological tests found that plasma treatment have positive effect on cells adhesion and proliferation cells and affects the size of cell’s adhesion area. Changes in plasma power or in exposure time influences the number of adhered and proliferated cells and their distribution on biopolymer surface.

  20. Study of messenger RNA inactivation and protein degradation in an Escherichia coli cell-free expression system

    Directory of Open Access Journals (Sweden)

    Noireaux Vincent

    2010-07-01

    Full Text Available Abstract Background A large amount of recombinant proteins can be synthesized in a few hours with Escherichia coli cell-free expression systems based on bacteriophage transcription. These cytoplasmic extracts are used in many applications that require large-scale protein production such as proteomics and high throughput techniques. In recent years, cell-free systems have also been used to engineer complex informational processes. These works, however, have been limited by the current available cell-free systems, which are not well adapted to these types of studies. In particular, no method has been proposed to increase the mRNA inactivation rate and the protein degradation rate in cell-free reactions. The construction of in vitro informational processes with interesting dynamics requires a balance between mRNA and protein synthesis (the source, and mRNA inactivation and protein degradation (the sink. Results Two quantitative studies are presented to characterize and to increase the global mRNA inactivation rate, and to accelerate the degradation of the synthesized proteins in an E. coli cell-free expression system driven by the endogenous RNA polymerase and sigma factor 70. The E. coli mRNA interferase MazF was used to increase and to adjust the mRNA inactivation rate of the Firefly luciferase (Luc and of the enhanced green fluorescent protein (eGFP. Peptide tags specific to the endogenous E. coli AAA + proteases were used to induce and to adjust the protein degradation rate of eGFP. Messenger RNA inactivation rate, protein degradation rate, maturation time of Luc and eGFP were measured. Conclusions The global mRNA turnover and the protein degradation rate can be accelerated and tuned in a biologically relevant range in a cell-free reaction with quantitative procedures easy to implement. These features broaden the capabilities of cell-free systems with a better control of gene expression. This cell-free extract could find some applications in

  1. Comparing the efficacy of chlorine, chlorine dioxide, and ozone in the inactivation of Cryptosporidium parvum in water from Parana State, Southern Brazil.

    Science.gov (United States)

    Pereira, Juliana Tracz; Costa, Adriana Oliveira; de Oliveira Silva, Márcia Benedita; Schuchard, Wagner; Osaki, Silvia Cristina; de Castro, Edilene Alcântara; Paulino, Rosangela Clara; Soccol, Vanete Thomaz

    2008-12-01

    In the present work, assays were performed to compare the efficacy of hypochlorous acid, chlorine dioxide, and ozone in the inactivation of Cryptosporidium oocyst in public water supply from Brazilian South conditions. Experiments were carried out in samples containing 2 x 10(4) oocysts/ml of C. parvum purified from feces of experimentally contaminated calves. An in vitro excystation method was used to evaluate oocysts' viability and to determine the inactivation rates of hypochlorous acid at 2 ppm, chlorine dioxide at 1, 2, and 5 ppm, and ozone at the doses of 0.18, 0.24, 0.36, 0.48, and 1.44 mg/l. By using hypochlorous acid, the maximum inactivation rate obtained was 49.04% after 120 min. Chlorine dioxide at 5 ppm inactivated 90.56% of oocysts after 90 min of contact. Ozone was the most effective product, rendering an inactivation of 100% with the concentration of 24 mg/l. Resistance of Cryptosporidium to the usual disinfectants and the need for more effective water treatments to prevent waterborne diseases in Brazil are discussed in this manuscript.

  2. Photodynamic Inactivation of E. coli PTCC 1276 Using Light Emitting Diodes: Application of Rose Bengal and Methylene Blue as Two Simple Models.

    Science.gov (United States)

    Kariminezhad, Hasan; Amani, Hossein; Khanbabaie, Reza; Biglarnia, Mahbobeh

    2017-07-01

    The lack of a comparative study about potential of high-power light emitting diodes (LEDs) for photodynamic inactivation (PDI) of pathogenic microorganisms has remained as a challenging issue for researchers. Therefore, the aim of this study is to fill this gap through introduction of an efficient model for in vitro PDI in an aqueous medium. For this purpose, two individual 30 mW/cm2 irradiation systems were designed using suitable sets of green and red LEDs. At another work, Methylene blue (MB) and Rose bengal (RB) as two simple models in the range of 5-150 μM were used in order to compare PDI of E. coli PTCC 1276 using red and green LED systems. Our results showed that a first-order mathematical model has the strength to describe the temporal variation of survival curves. Based on our results, when concentration of photosensitizer increased, the rate of inactivation for RB increased while MB depicted a maximum rate value at 25 μM. In a comparative study, optimum inactivation of E. coli PTCC 1276 obtained during 2- and 10-min irradiation of the LED systems using RB and MB at 150 and 25 μM, respectively. With regard to lower value of inactivation time and higher rate of inactivation for RB, use of simultaneous green high-power LEDs and RB is proposed as an efficient approach for PDI of pathogenic bacteria in future industrial applications.

  3. New Proof-of-Concept in Viral Inactivation: Virucidal Efficacy of 405 nm Light Against Feline Calicivirus as a Model for Norovirus Decontamination.

    Science.gov (United States)

    Tomb, Rachael M; Maclean, Michelle; Coia, John E; Graham, Elizabeth; McDonald, Michael; Atreya, Chintamani D; MacGregor, Scott J; Anderson, John G

    2017-06-01

    The requirement for novel decontamination technologies for use in hospitals is ever present. One such system uses 405 nm visible light to inactivate microorganisms via ROS-generated oxidative damage. Although effective for bacterial and fungal inactivation, little is known about the virucidal effects of 405 nm light. Norovirus (NoV) gastroenteritis outbreaks often occur in the clinical setting, and this study was designed to investigate potential inactivation effects of 405 nm light on the NoV surrogate, feline calicivirus (FCV). FCV was exposed to 405 nm light whilst suspended in minimal and organically-rich media to establish the virucidal efficacy and the effect biologically-relevant material may play in viral susceptibility. Antiviral activity was successfully demonstrated with a 4 Log 10 (99.99%) reduction in infectivity when suspended in minimal media evident after a dose of 2.8 kJ cm -2 . FCV exposed in artificial faeces, artificial saliva, blood plasma and other organically rich media exhibited an equivalent level of inactivation using between 50-85% less dose of the light, indicating enhanced inactivation when the virus is present in organically-rich biologically-relevant media. Further research in this area could aid in the development of 405 nm light technology for effective NoV decontamination within the hospital environment.

  4. Plasma spectroscopy

    CERN Document Server

    Fujimoto, Takashi

    2004-01-01

    Plasma is ubiquitous, whether it occurs in cooking gas flames, fluorescent lamps or in the sun and the stars. This book deals with the light that these plasmas emit, the characteristics of the light, and why it occurs. The author provides a framework from which a coherent account of this phenomena can be made.

  5. Plasma Decontamination: A Case Study on Kill Efficacy of Geobacillus stearothermophilus Spores on Different Carrier Materials.

    Science.gov (United States)

    Semmler, Egmont; Novak, Wenzel; Allinson, Wilf; Wallis, Darren; Wood, Nigel; Awakowicz, Peter; Wunderlich, Joachim

    2016-01-01

    A new technology to the pharmaceutical field is presented: surface decontamination by plasmas The technology is comparable to established barrier systems like e-beam, volatile hydrogen peroxide, or radiation inactivation of microbiological contaminations. This plasma technology is part of a fully automated and validated syringe filling line at a major pharmaceutical company and is in production operation. Incoming pre-sterilized syringe containers ("tubs") are processed by plasma, solely on the outside, and passed into the aseptic filling isolator upon successful decontamination. The objective of this article is to present the operating principles and develop and establish a validation routine on the basis of standard commercial biological indicators. Their decontamination efficacies are determined and correlated to the actual inactivation efficacy on the pharmaceutical packaging material.The reference setup is explained in detail and a short presentation of the cycle development and the relevant plasma control parameters is given, with a special focus on the in-process monitor determining the cycle validity. Different microbial inactivation mechanisms are also discussed and evaluated for their contribution and interaction to enhance plasma decontamination. A material-dependent inactivation behavior was observed. In order to be able to correlate the tub surface inactivation of Geobacillus stearothermophilus endospores to metallic biological indicators, a comparative study was performed. Through consistently demonstrating the linear inactivation behavior between the different materials, it becomes possible to develop an effective and time-saving validation scheme. The challenge in new decontamination systems lies in a thorough validation of the inactivation efficacy under different operating regimes. With plasma, as an ionized gas, a new barrier concept is introduced into pharmaceutical aseptic processing of syringes. The presented system operates in vacuum and only

  6. Evaluation of Chlorine Treatment Levels for Inactivation of Human Norovirus and MS2 Bacteriophage during Sewage Treatment.

    Science.gov (United States)

    Kingsley, David H; Fay, Johnna P; Calci, Kevin; Pouillot, Régis; Woods, Jacquelina; Chen, Haiqiang; Niemira, Brendan A; Van Doren, Jane M

    2017-12-01

    This study examined the inactivation of human norovirus (HuNoV) GI.1 and GII.4 by chlorine under conditions mimicking sewage treatment. Using a porcine gastric mucin-magnetic bead (PGM-MB) assay, no statistically significant loss in HuNoV binding (inactivation) was observed for secondary effluent treatments of ≤25 ppm total chlorine; for both strains, 50 and 100 ppm treatments resulted in ≤0.8-log 10 unit and ≥3.9-log 10 unit reductions, respectively. Treatments of 10, 25, 50, and 100 ppm chlorine inactivated 0.31, 1.35, >5, and >5 log 10 units, respectively, of the norovirus indicator MS2 bacteriophage. Evaluation of treatment time indicated that the vast majority of MS2 and HuNoV inactivation occurred in the first 5 min for 0.2-μm-filtered, prechlorinated secondary effluent. Free chlorine measurements of secondary effluent seeded with MS2 and HuNoV demonstrated substantial oxidative burdens. With 25, 50, and 100 ppm treatments, free chlorine levels after 5 min of exposure ranged from 0.21 to 0.58 ppm, from 0.28 to 16.7 ppm, and from 11.6 to 53 ppm, respectively. At chlorine treatment levels of >50 ppm, statistically significant differences were observed between reductions for PGM-MB-bound HuNoV (potentially infectious) particles and those for unbound (noninfectious) HuNoV particles or total norovirus particles. While results suggested that MS2 and HuNoV (measured as PGM-MB binding) behave similarly, although not identically, both have limited susceptibility to chlorine treatments of ≤25 ppm total chlorine. Since sewage treatment is performed at ≤25 ppm total chlorine, targeting free chlorine levels of 0.5 to 1.0 ppm, these results suggest that traditional chlorine-based sewage treatment does not inactivate HuNoV efficiently. IMPORTANCE HuNoV is ubiquitous in sewage. A receptor binding assay was used to assess inactivation of HuNoV by chlorine-based sewage treatment, given that the virus cannot be routinely propagated in vitro Results reported here

  7. Different impact of heat-inactivated and viable lactic acid bacteria of aquatic origin on turbot (Scophthalmus maximus L.) head-kidney leucocytes.

    Science.gov (United States)

    Muñoz-Atienza, Estefanía; Araújo, Carlos; Lluch, Nuria; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M; Magadán, Susana

    2015-05-01

    In aquaculture, several criteria should be considered to select an appropriate probiotic, including the aquatic origin and safety of the strain and its ability to modulate the host immune response. The properties and effects of probiotics are strain-specific and some factors such as viability, dose and duration of diet supplementation may regulate their immunomodulatory activities. In this study, we assessed the in vitro effect of eight heat-inactivated and viable lactic acid bacteria (LAB) of aquatic origin belonging to the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella on the viability and innate immune response of turbot (Scophthalmus maximus L.) leucocytes. Head-kidney leucocytes were incubated with viable and heat-inactivated LAB at different concentrations. After incubation, the viability of leucocytes was evaluated using colorimetric assays (MTT and LDH) and flow cytometry (annexin V/propidium iodide). Heat-inactivated LAB showed no cytotoxic effect while viable LAB exerted variable influence on apoptosis of turbot phagocytes and lymphocytes. Leucocyte respiratory burst activity and phagocytosis were also differentially activated, as viable LAB stimulated leucocytes more efficiently than the heat-inactivated LAB. Our results suggest diverse strain-specific mechanisms of interaction between the evaluated LAB and turbot leucocytes. Furthermore, our work sets up in vitro systems to evaluate the effect of LAB as potential probiotics, which will be useful to develop efficient screening. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. PLASMA ENERGIZATION

    Science.gov (United States)

    Furth, H.P.; Chambers, E.S.

    1962-03-01

    BS>A method is given for ion cyclotron resonance heatthg of a magnetically confined plasma by an applied radio-frequency field. In accordance with the invention, the radiofrequency energy is transferred to the plasma without the usual attendent self-shielding effect of plasma polarlzatlon, whereby the energy transfer is accomplished with superior efficiency. More explicitly, the invention includes means for applying a radio-frequency electric field radially to an end of a plasma column confined in a magnetic mirror field configuration. The radio-frequency field propagates hydromagnetic waves axially through the column with the waves diminishing in an intermediate region of the column at ion cyclotron resonance with the fleld frequency. In such region the wave energy is converted by viscous damping to rotational energy of the plasma ions. (AEC)

  9. Aβ seeds resist inactivation by formaldehyde.

    Science.gov (United States)

    Fritschi, Sarah K; Cintron, Amarallys; Ye, Lan; Mahler, Jasmin; Bühler, Anika; Baumann, Frank; Neumann, Manuela; Nilsson, K Peter R; Hammarström, Per; Walker, Lary C; Jucker, Mathias

    2014-10-01

    Cerebral β-amyloidosis can be exogenously induced by the intracerebral injection of brain extracts containing aggregated β-amyloid (Aβ) into young, pre-depositing Aβ precursor protein- (APP) transgenic mice. Previous work has shown that the induction involves a prion-like seeding mechanism in which the seeding agent is aggregated Aβ itself. Here we report that the β-amyloid-inducing activity of Alzheimer's disease (AD) brain tissue or aged APP-transgenic mouse brain tissue is preserved, albeit with reduced efficacy, after formaldehyde fixation. Moreover, spectral analysis with amyloid conformation-sensitive luminescent conjugated oligothiophene dyes reveals that the strain-like properties of aggregated Aβ are maintained in fixed tissues. The resistance of Aβ seeds to inactivation and structural modification by formaldehyde underscores their remarkable durability, which in turn may contribute to their persistence and spread within the body. The present findings can be exploited to establish the relationship between the molecular structure of Aβ aggregates and the variable clinical features and disease progression of AD even in archived, formalin-fixed autopsy material.

  10. Inactivation of RNA viruses by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nonomiya, Takashi; Morimoto, Akinori; Iwatsuki, Kazuo; Tsutsumi, Takamasa (Ministry of Agriculture, Forestry and fisheries, Yokohama, Kanagawa (Japan). Animal Quarantine Service); Ito, Hitoshi; Yamashiro, Tomio; Ishigaki, Isao

    1992-09-01

    Four kinds of RNA viruses, Bluetongue virus (BT), Bovine Virus Diarrhea-Mucosal Disease virus (BVD[center dot]MD), Bovine Respiratory Syncytial virus (RS), Vesicular Stmatitis virus (VS), were subjected to various doses of gamma irradiation to determine the lethal doses. The D[sub 10] values, which are the dose necessary to decimally reduce infectivity, ranged from 1.5 to 3.4 kGy under frozen condition at dry-ice temperature, and they increased to 2.6 to 5.0 kGy under frozen condition at dry-ice temperature. Serum neutralzing antibody titer of Infectious Bovine Rhinotracheitis (IBR) was not adversely changed by the exposure to 36 kGy of gamma-rays under frozen condition. Analysis of electrophoresis patterns of the bovine serum also reveales that the serum proteins were not remarkably affected, even when exposed to 36 kGy of gamma radiation under frozen condition. The results suggested that gamma irradiation under frozen condition is an effective means for inactivating both DNA and RNA viruses without adversely affecting serum proteins and neutralizing antibody titer. (author).

  11. CHLORINE INACTIVATION OF CATEGORY "A" BIO-TERRORISM AGENTS

    Science.gov (United States)

    This poster presents information on the inactivation of select bioterrorist agents. Information will be presented on chlorine disinfection of vegetative cells of Brucella suis, Brucella melitensis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis and endos...

  12. Use of genetic algorithms for high hydrostatic pressure inactivation ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    ) for high hydrostatic pressure (HHP) inactivation of Bacillus cereus spores, Bacillus subtilis spores and cells,. Staphylococcus aureus and Listeria monocytogenes, all in milk buffer, were used to demonstrate the utility of ...

  13. Inactivation Strategies for Clostridium perfringens Spores and Vegetative Cells.

    Science.gov (United States)

    Talukdar, Prabhat K; Udompijitkul, Pathima; Hossain, Ashfaque; Sarker, Mahfuzur R

    2017-01-01

    Clostridium perfringens is an important pathogen to human and animals and causes a wide array of diseases, including histotoxic and gastrointestinal illnesses. C. perfringens spores are crucial in terms of the pathogenicity of this bacterium because they can survive in a dormant state in the environment and return to being live bacteria when they come in contact with nutrients in food or the human body. Although the strategies to inactivate C. perfringens vegetative cells are effective, the inactivation of C. perfringens spores is still a great challenge. A number of studies have been conducted in the past decade or so toward developing efficient inactivation strategies for C. perfringens spores and vegetative cells, which include physical approaches and the use of chemical preservatives and naturally derived antimicrobial agents. In this review, different inactivation strategies applied to control C. perfringens cells and spores are summarized, and the potential limitations and challenges of these strategies are discussed. Copyright © 2016 American Society for Microbiology.

  14. Inactivation of rabies diagnostic reagents by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, W.C.; Chappell, W.A.; George, E.H.

    1980-11-01

    Treatment of CVS-11 rabies adsorbing suspensions and street rabies infected mouse brains with gamma radiation resulted in inactivated reagents that are safer to distribute and use. These irradiated reagents were as sensitive and reactive as the nonirradiated control reagents.

  15. Biocontrol interventions for inactivation of foodborne pathogens on produce

    Science.gov (United States)

    Post-harvest interventions for control of foodborne pathogens on minimally processed foods are crucial for food safety. Biocontrol interventions have the primary objective of developing novel antagonists in combinations with physical and chemical interventions to inactivate pathogenic microbes. Ther...

  16. Enzyme inactivation kinetics: Coupled effects of temperature and moisture content

    NARCIS (Netherlands)

    Perdana, J.A.; Fox, M.B.; Schutyser, M.A.I.; Boom, R.M.

    2012-01-01

    Enzymes are often dried for stability reasons and to facilitate handling. However, they are often susceptible to inactivation during drying. It is generally known that temperature and moisturecontent influence the enzymeinactivation kinetics. However, the coupledeffect of both variables on

  17. Enterococcus faecalis and pathogenic streptococci inactivate daptomycin by releasing phospholipids.

    Science.gov (United States)

    Ledger, Elizabeth V K; Pader, Vera; Edwards, Andrew M

    2017-10-01

    Daptomycin is a lipopeptide antibiotic with activity against Gram-positive bacteria. We showed previously that Staphylococcus aureus can survive daptomycin exposure by releasing membrane phospholipids that inactivate the antibiotic. To determine whether other pathogens possess this defence mechanism, phospholipid release and daptomycin activity were measured after incubation of Staphylococcus epidermidis, group A or B streptococci, Streptococcus gordonii or Enterococcus faecalis with the antibiotic. All bacteria released phospholipids in response to daptomycin, which resulted in at least partial inactivation of the antibiotic. However, E. faecalis showed the highest levels of lipid release and daptomycin inactivation. As shown previously for S. aureus, phospholipid release by E. faecalis was inhibited by the lipid biosynthesis inhibitor platensimycin. In conclusion, several pathogenic Gram-positive bacteria, including E. faecalis, inactivate daptomycin by releasing phospholipids, which may contribute to the failure of daptomycin to resolve infections caused by these pathogens.

  18. Evaluation of the Efficacy of Inactivated Oil-Emulsion Newcastle ...

    African Journals Online (AJOL)

    Evaluation of the Efficacy of Inactivated Oil-Emulsion Newcastle Disease Komarov Vaccine against Clinical Disease, Lesions and Immune Response, Following Challenge with Velogenic Newcastle Disease Virus in Laying Chickens.

  19. 21 CFR 610.11a - Inactivated influenza vaccine, general safety test.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Inactivated influenza vaccine, general safety test... Inactivated influenza vaccine, general safety test. For inactivated influenza vaccine, the general safety test... subcutaneous or intraperitoneal injection of 5.0 milliliters of inactivated influenza vaccine into each guinea...

  20. Shaker IR T449 mutants separate C- from U-type inactivation.

    Science.gov (United States)

    Jamieson, Quentin; Jones, Stephen W

    2014-04-01

    Previous studies demonstrated that slow inactivation of the Shaker potassium channel can be made ~100-fold faster or slower by point mutations at a site in the outer pore (T449). However, the discovery that two forms of slow inactivation coexist in Shaker raises the question of which inactivation process is affected by mutation. Equivalent mutations in K(V)2.1, a channel exhibiting only U-type inactivation, have minimal effects on inactivation, suggesting that mutation of Shaker T449 acts on C-type inactivation alone, a widely held yet untested hypothesis. This study reexamines mutations at Shaker T449, confirming that T449A speeds inactivation and T449Y/V slow it. T449Y and T449V exhibit U-type inactivation that is enhanced by high extracellular potassium, in contrast to C-type inactivation in T449A which is inhibited by high potassium. Automated parameter estimation for a 12-state Markov model suggests that U-type inactivation occurs mainly from closed states upon weak depolarization, but primarily from the open state at positive voltages. The model also suggests that WT channels, which in this study exhibit mostly C-type inactivation, recover from inactivation through closed-inactivated states, producing voltage-dependent recovery. This suggests that both C-type and U-type inactivation involve both open-inactivated and closed-inactivated states.

  1. Pokeweed antiviral protein inactivates pokeweed ribosomes; implications for the antiviral mechanism.

    Science.gov (United States)

    Bonness, M S; Ready, M P; Irvin, J D; Mabry, T J

    1994-02-01

    Pokeweed antiviral protein (PAP) and other ribosome-inactivating proteins (RIPs) had previously been thought to be incapable of attacking conspecific ribosomes, thus having no effect on endogenous processes. This assertion conflicts with a model for PAP's in vivo antiviral mechanism in which PAP (a cell wall protein) selectively enters virus-infected cells and disrupts protein synthesis, thus causing local suicide and preventing virus replication. We show here that pokeweed (Phytolacca americana) ribosomes, as well as endod (Phytolacca dodecandra) ribosomes, are indeed highly sensitive to inactivation by conspecific RIPs. Ribosomes isolated from RIP-free pokeweed and endod suspension culture cells were found to be highly active in vitro, as measured by poly(U)-directed polyphenylalanine synthesis. Phytolacca ribosomes challenged with conspecific RIPs generated dose-response curves (IC50 of 1 nM PAP or dodecandrin) very similar to those from wheat germ ribosomes. To determine if Phytolacca cells produce a cytosolic 'anti-RIP' protective element, ribosomes were combined with Phytolacca postribosomal supernatant factors from culture cells, then challenged with conspecific RIPs. Resulting IC50 values of 3-7 nM PAP, PAP-II, PAP-S or dodecandrin indicate that supernatants from these Phytolacca cells lack a ribosomal protective element. This research demonstrates that PAP inactivates pokeweed ribosomes (and is therefore potentially toxic to pokeweed cells) and supports the local suicide model for PAP's in vivo antiviral mechanism. The importance of spatial separation between PAP and ribosomes of cells producing this RIP is emphasized, particularly if crop plants are transformed with the PAP gene to confer antiviral protection.

  2. Stochastic and deterministic model of microbial heat inactivation.

    Science.gov (United States)

    Corradini, Maria G; Normand, Mark D; Peleg, Micha

    2010-03-01

    Microbial inactivation is described by a model based on the changing survival probabilities of individual cells or spores. It is presented in a stochastic and discrete form for small groups, and as a continuous deterministic model for larger populations. If the underlying mortality probability function remains constant throughout the treatment, the model generates first-order ("log-linear") inactivation kinetics. Otherwise, it produces survival patterns that include Weibullian ("power-law") with upward or downward concavity, tailing with a residual survival level, complete elimination, flat "shoulder" with linear or curvilinear continuation, and sigmoid curves. In both forms, the same algorithm or model equation applies to isothermal and dynamic heat treatments alike. Constructing the model does not require assuming a kinetic order or knowledge of the inactivation mechanism. The general features of its underlying mortality probability function can be deduced from the experimental survival curve's shape. Once identified, the function's coefficients, the survival parameters, can be estimated directly from the experimental survival ratios by regression. The model is testable in principle but matching the estimated mortality or inactivation probabilities with those of the actual cells or spores can be a technical challenge. The model is not intended to replace current models to calculate sterility. Its main value, apart from connecting the various inactivation patterns to underlying probabilities at the cellular level, might be in simulating the irregular survival patterns of small groups of cells and spores. In principle, it can also be used for nonthermal methods of microbial <