Response of Controlled Cell Load Biofilms to Cold Atmospheric Plasma Jet: Evidence of Extracellular Matrix Contribution

Aim: Study of the biocidal effect of a cold atmospheric-pressure plasma in ambient air on single-species bacterial biofilms with controlled cell density, characterized by different extracellular matrices. Methods and results: Two bacterial strains were chosen to present different Gram properties and contrasted extracellular matrices: Pseudomonas aeruginosa ATCC 15442 (Gram-negative), and Leuconostoc citreum NRRL B-1299 (Gram-positive). P. aeruginosa biofilm exhibits a complex matrix, rich in proteins while L. citreum presents the specificity to produce glucan-type exopolysaccharides when grown in the presence of sucrose. Plasma was applied on both surface-spread cells and 24-h grown biofilms with controlled cell loads over 5, 10, or 20 min. Surface-spread bacteria showed a time dependent response, with a maximal bacterial reduction of 2.5 log after 20 min of treatment. On the other hand, in our experimental conditions, no bactericidal effect could be observed when treating biofilms of P. aeruginosa and glucan-rich L. citreum. Conclusions: For biofilms presenting equivalent cell loads, the response to plasma treatment seemed to depend on the properties of the extracellular matrix characterized by infrared spectroscopy, scanning electron microscopy, or dry weight. Significance and impact of study: Both cell load standardization and biofilm characterization are paramount factors to consider the biocide effect of plasma treatments. The extracellular matrix could affect the plasma efficacy by physical and/or chemical protective effects.

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Desmopressin (DDAVP) Enhances Platelet Adhesion to the Extracellular Matrix of Cultured Human Endothelial Cells through Increased Expression of Tissue Factor

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656088 ◽

1997 ◽

Vol 77 (05) ◽

pp. 0975-0980 ◽

Cited By ~ 23

Author(s):

Angel Gálvez ◽

Goretti Gómez-Ortiz ◽

Maribel Díaz-Ricart ◽

Ginés Escolar ◽

Rogelio González-Sarmiento ◽

...

Keyword(s):

Extracellular Matrix ◽

Endothelial Cells ◽

Tissue Factor ◽

Platelet Adhesion ◽

Umbilical Vein ◽

Procoagulant Activity ◽

Experimental Conditions ◽

Chromogenic Assay

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.

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Plasma-Activated Water (PAW) as a Disinfection Technology for Bacterial Inactivation with a Focus on Fruit and Vegetables

Foods ◽

10.3390/foods10010166 ◽

2021 ◽

Vol 10 (1) ◽

pp. 166

Author(s):

Aswathi Soni ◽

Jonghyun Choi ◽

Gale Brightwell

Keyword(s):

Fruit And Vegetables ◽

Atmospheric Plasma ◽

Model Systems ◽

Thermal Treatments ◽

Bacterial Cells ◽

Bacterial Inactivation ◽

Gas Temperature ◽

Bacterial Strains ◽

Sensory Qualities ◽

Plasma Activated Water

Plasma-activated water (PAW) is generated by treating water with cold atmospheric plasma (CAP) using controllable parameters, such as plasma-forming voltage, carrier gas, temperature, pulses, or frequency as required. PAW is reported to have lower pH, higher conductivity, and higher oxygen reduction potential when compared with untreated water due to the presence of reactive species. PAW has received significant attention from researchers over the last decade due to its non-thermal and non-toxic mode of action especially for bacterial inactivation. The objective of the current review is to develop a summary of the effect of PAW on bacterial strains in foods as well as model systems such as buffers, with a specific focus on fruit and vegetables. The review elaborated the properties of PAW, the effect of various treatment parameters on its efficiency in bacterial inactivation along with its usage as a standalone technology as well as a hurdle approach with mild thermal treatments. A section highlighting different models that can be employed to generate PAW alongside a direct comparison of the PAW characteristics on the inactivation potential and the existing research gaps are also included. The mechanism of action of PAW on the bacterial cells and any reported effects on the sensory qualities and shelf life of food has been evaluated. Based on the literature, it can be concluded that PAW offers a significant potential as a non-chemical and non-thermal intervention for bacterial inactivation, especially on food. However, the applicability and usage of PAW depend on the effect of environmental and bacterial strain-based conditions and cost-effectiveness.

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MORPHOGENETIC ASPECTS OF MULTILAYERING IN PETRI DISH CULTURES OF HUMAN FETAL LUNG FIBROBLASTS

The Journal of Cell Biology ◽

10.1083/jcb.41.1.298 ◽

1969 ◽

Vol 41 (1) ◽

pp. 298-311 ◽

Cited By ~ 42

Author(s):

Tom Elsdale ◽

Robert Foley

Keyword(s):

Extracellular Matrix ◽

Human Lung ◽

Petri Dish ◽

Fetal Lung ◽

Single Species ◽

Lung Fibroblasts ◽

Human Lung Fibroblasts ◽

Spontaneous Aggregation ◽

Control Hypothesis ◽

Human Fetal Lung

Randomly seeded Petri dish cultures of embryonic human lung fibroblasts generate, in the course of their growth, highly ordered cellular arrangements. Thick, bilaterally symmetrical ridges with an axial polarity and an orthogonal, multilayered internal organization are observed within stationary cultures. The generation of these structures has been investigated. Ridges result from the spontaneous aggregation of cells in postconfluent cultures brought about by directed cell movements. These movements are promoted by the localized production of extracellular matrix sheets containing collagen, which provide new substrates for cellular colonization. Cells that have colonized one matrix substrate may secrete another above themselves, which will in turn be colonized. By a continuation of this cycle, thick stacks consisting of alternate layers of cells and matrix are produced to yield the observed aggregations. The distribution and shape of ridges in a culture imply that matrix substrates are confined to specific locations. The suggested control hypothesis assumes that all the cells in fibroblast cultures are potential producers of a single species of matrix. The serviceability of this matrix as a substrate for cellular colonization, however, is destroyed if the producer cells are motile. Matrix substrates, therefore, are only made by nonmotile cells.

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Seasonal Variation in Essential Oils Composition and the Biological and Pharmaceutical Protective Effects of Mentha longifolia Leaves Grown in Tunisia

BioMed Research International ◽

10.1155/2018/7856517 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 10

Author(s):

Karama Zouari-Bouassida ◽

Mohamed Trigui ◽

Samar Makni ◽

Lobna Jlaiel ◽

Slim Tounsi

Keyword(s):

Seasonal Variation ◽

Essential Oils ◽

Biological Activities ◽

Winter Season ◽

Inflammatory Cells ◽

Ethyl Acetate Fraction ◽

Activity Level ◽

Potential Candidate ◽

Protective Effects ◽

Bacterial Strains

This research assessed the seasonal variation of the chemical composition and antibacterial and anticholinesterase activities of essential oils extracted from M. longifolia leaves. The leaves organic fractions were also investigated for their biological activities and pharmacological functions. The essential oil highest yield was recorded in the spring season. Pulegone (26.92%), 1.8 cineole (21.3 %), and L-menthone (10.66 %) were determined as its major compounds in the winter season. In the spring oil, the main components were pulegone (38.2 %) and oleic and palmitic acids (23.79 % and 15. 26 %, respectively). Oxygenated monoterpenes were predominant in the two analyzed samples. The tested oils and organic extracts exhibited promising antibacterial effects against all of the tested bacterial strains. Thanks to its richness in phenolic and flavonoid compounds, the ethyl acetate fraction (Ml EtOAcF) displayed the most active DPPH scavenging ability (IC50 =12.64 μg/ml) and an interesting β-carotene bleaching inhibition (IC50 =34.75 μg/ml) making it a potential candidate for anti-inflammatory evaluation on rats. This evaluation evidenced that M. longifolia pretreated rats showed a marked decrease in paw oedema and inflammatory cells. Additionally, a remarkable acetylcholinesterase inhibitory activity of the Ml EtOAcF (IC50 = 12.3μg/ml) and essential oils were also observed suggesting their neuroprotective property against Alzheimer’s disease. Moreover, it was found that its activity level was season dependent. Our investigation, therefore, clearly revealed the medicinal characteristics of M. longifolia leave indicating their potential uses for natural remedies.

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Laser filament-induced aerosol formation

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-4593-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 4593-4604 ◽

Cited By ~ 20

Author(s):

H. Saathoff ◽

S. Henin ◽

K. Stelmaszczyk ◽

M. Petrarca ◽

R. Delagrange ◽

...

Keyword(s):

Particle Production ◽

Ambient Air ◽

Particle Formation ◽

Oxygen Mixture ◽

Atmospheric Conditions ◽

Aerosol Formation ◽

Experimental Conditions ◽

Particle Yield ◽

The Given ◽

Terawatt Laser

Abstract. Using the aerosol and cloud simulation chamber AIDA, we investigated the laser filament induced particle formation in ambient air, humid synthetic air, humid nitrogen, argon–oxygen mixture, and pure argon in order to simulate the particle formation under realistic atmospheric conditions as well as to investigate the influence of typical gas-phase atmospheric constituents on the particle formation. Terawatt laser plasma filaments generated new particles in the size range 3 to 130 nm with particle production rates ranging from 1 × 107 to 5 × 109 cm−3 plasma s−1 for the given experimental conditions. In all cases the particle formation rates increased exponentially with the water content of the gas mixture. Furthermore, the presence of a few ppb of trace gases like SO2 and α-pinene clearly enhanced the particle yield by number, the latter also by mass. Our findings suggest that new particle formation is efficiently supported by oxidized species like acids generated by the photoionization of both major and minor components of the air, including N2, NH3, SO2 and organics.

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DNA Interaction and Biological Activities of Heteroleptic Palladium (II) Complexes

Journal of the chemical society of pakistan ◽

10.52568/000566 ◽

2021 ◽

Vol 43 (2) ◽

pp. 227-227

Author(s):

Muhammad Anwar Saeed Muhammad Anwar Saeed ◽

Hizbullah Khan Hizbullah Khan ◽

Muhammad Sirajuddin Muhammad Sirajuddin ◽

Syed Muhammad Salman Syed Muhammad Salman

Keyword(s):

Biological Activities ◽

Thiobarbituric Acid ◽

Dna Interaction ◽

Log P ◽

Bacterial Strains ◽

Experimental Conditions ◽

H2o2 Treatment ◽

Biological Studies ◽

Almost All ◽

Anti Fungal

The manuscript describes the binding of DNA as well as biological studies of some mixed ligand dithiocarbamate Palladium (II) complexes (1-5). The observed compounds are of general formulae [PdCl(DT)(PR3)]. The dithiocarbamate “DT” and “PR3” groups are varied among the studied complexes as DT = bis[(2-methoxyethyl) dithiocarbamate)] (1 and 2), dibutyl dithiocarbamate (4 and 5), bis[(2-ethyl) hexyl dithiocarbamate)] (3); PR3 = triphenyl phosphine (1), benzy diphenyl phosphine (2), diphenyl-tert-butyl phpsphine (3), diphenyl-p-tolyl phosphine (4) and diphenyl-2-methoxy phenyl phosphine (5). The synthesized complexes were screened for DNA binding study via (UV Visible spectrophotometry and Viscometery) and biological activities such as anti-bacterial and anti-fungal, Molinspiration calculations and antioxidant potencies stimulated by hydrogen peroxide in human blood lymphocytes. In case of drug DNA interaction, complexes showed some sort of interaction with DNA solution. Almost all the complexes exhibited moderate antifungal and antibacterial behavior (against Gram positive and negative bacterial strains). The Molinspiration calculation study revealed that the said Pd (II) mixed complexes are biologically significant drugs having adequate molecular properties regarding drug likeness, except the log P values of complexes 3-5 because some structural adjustments must be done for enhancement of their bioavailability and hydrophilic nature. Regarding the antioxidant potential of complexes 1, 2 and 4, the H2O2 treatment of complexes violently decreased the action of antioxidant enzymes, superoxide dismutase and catalase and enhanced the level of thiobarbituric acid-reacting substances. Under experimental conditions, we conclude that all complexes act as anti-mutagens as they significantly suppress H2O2-induced oxidative damage at non-genotoxic concentrations.

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Joint effect of Fe(II) and Fe(III) cations on corrosion of low-carbon steel in mixture of sulfuric and phosphoric acids containing composite inhibitors based on IFKhAN-92

Corrosion Materials Protection ◽

10.31044/1813-7016-2021-0-8-18-29 ◽

2021 ◽

pp. 18-29

Author(s):

Ya.G. Avdeev ◽

◽

A.V. Panova ◽

T.E. Andreeva ◽

Yu.I. Kuznetsov ◽

...

Keyword(s):

Carbon Steel ◽

Low Carbon Steel ◽

Steel Corrosion ◽

Joint Effect ◽

Molar Ratio ◽

Protective Effects ◽

Low Carbon ◽

Experimental Conditions ◽

Component Mixture ◽

LABORATORY ASPECTS OF ANTIBIOTIC THERAPY

PEDIATRICS ◽

10.1542/peds.8.3.406 ◽

1951 ◽

Vol 8 (3) ◽

pp. 406-412

Author(s):

EARLE H. SPAULDING

Keyword(s):

Antibiotic Therapy ◽

Single Species ◽

Clinical Results ◽

Bacterial Strains ◽

In Vitro Susceptibility ◽

Bacterial Cultures ◽

Susceptibility Tests ◽

And Control ◽

Susceptibility Patterns

Bacterial strains within a single species exhibit highly specific susceptibility patterns when tested with the several antibiotics currently available. Because in vitro susceptibility tests constitute the only certain method for predicting clinical response, the bacteriology laboratory is playing an expanding part in the choice and control of antibiotic therapy. Although there is no need for bacteriologic studies in the vast majority of infections, they are sometimes essential to the successful management of severe acute, refractory and relapsing infections. The correlation between laboratory and clinical results is good providing allowances are made for certain factors discussed in this paper. Antibiotic susceptibility tests are entirely practical and should be used routinely in all laboratories which do bacterial cultures.

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Evaluation of the accuracy of thermal dissociation CRDS and LIF techniques for atmospheric measurement of reactive nitrogen species

Atmospheric Measurement Techniques ◽

10.5194/amt-10-1911-2017 ◽

2017 ◽

Vol 10 (5) ◽

pp. 1911-1926 ◽

Cited By ~ 11

Author(s):

Caroline C. Womack ◽

J. Andrew Neuman ◽

Patrick R. Veres ◽

Scott J. Eilerman ◽

Charles A. Brock ◽

...

Keyword(s):

Conversion Efficiency ◽

Reactive Nitrogen Species ◽

Thermal Dissociation ◽

Ambient Air ◽

Reactive Nitrogen ◽

Organic Nitrates ◽

Nitrogen Species ◽

Operating Characteristics ◽

Experimental Conditions ◽

Standard Additions

Abstract. The sum of all reactive nitrogen species (NOy) includes NOx (NO2 + NO) and all of its oxidized forms, and the accurate detection of NOy is critical to understanding atmospheric nitrogen chemistry. Thermal dissociation (TD) inlets, which convert NOy to NO2 followed by NO2 detection, are frequently used in conjunction with techniques such as laser-induced fluorescence (LIF) and cavity ring-down spectroscopy (CRDS) to measure total NOy when set at > 600 °C or speciated NOy when set at intermediate temperatures. We report the conversion efficiency of known amounts of several representative NOy species to NO2 in our TD-CRDS instrument, under a variety of experimental conditions. We find that the conversion efficiency of HNO3 is highly sensitive to the flow rate and the residence time through the TD inlet as well as the presence of other species that may be present during ambient sampling, such as ozone (O3). Conversion of HNO3 at 400 °C, nominally the set point used to selectively convert organic nitrates, can range from 2 to 6 % and may represent an interference in measurement of organic nitrates under some conditions. The conversion efficiency is strongly dependent on the operating characteristics of individual quartz ovens and should be well calibrated prior to use in field sampling. We demonstrate quantitative conversion of both gas-phase N2O5 and particulate ammonium nitrate in the TD inlet at 650 °C, which is the temperature normally used for conversion of HNO3. N2O5 has two thermal dissociation steps, one at low temperature representing dissociation to NO2 and NO3 and one at high temperature representing dissociation of NO3, which produces exclusively NO2 and not NO. We also find a significant interference from partial conversion (5–10 %) of NH3 to NO at 650 °C in the presence of representative (50 ppbv) levels of O3 in dry zero air. Although this interference appears to be suppressed when sampling ambient air, we nevertheless recommend regular characterization of this interference using standard additions of NH3 to TD instruments that convert reactive nitrogen to NO or NO2.

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Scaffold-supported extracellular matrices preserved by magnesium hydroxide nanoparticles for renal tissue regeneration

Biomaterials Science ◽

10.1039/d0bm00871k ◽

2020 ◽

Vol 8 (19) ◽

pp. 5427-5440 ◽

Cited By ~ 1

Author(s):

Yun Ah Kim ◽

So Young Chun ◽

Sung-Bin Park ◽

Eunyoung Kang ◽

Won-Gun Koh ◽

...

Keyword(s):

Extracellular Matrix ◽

Tissue Regeneration ◽

Magnesium Hydroxide ◽

Renal Tissue ◽

Extracellular Matrices ◽

Magnesium Hydroxide Nanoparticles

Fibroblast-derived extracellular matrix-supported scaffolds made up of PLGA were prepared with the enhanced preservation of ECM components by composites with magnesium hydroxide nanoparticles, and were applied for renal tissue regeneration.

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