Comparison of methylene blue/gentian violet stain to Gram's stain for the rapid diagnosis of gonococcal urethritis in men.

PubMed

Taylor, Stephanie N; DiCarlo, Richard P; Martin, David H

2011-11-01

We compared a simple, one-step staining procedure using a mixture of methylene blue and gentian violet to Gram stain for the detection of gonococcal urethritis. The sensitivity and specificity of both Gram stain and methylene blue/gentian violet stain were 97.3% and 99.6%, respectively. There was a 100% correlation between the 2 methods.

[Effects of methyl tertiary butyl ether on cell cycle and cell apoptosis].

PubMed

Zhou, W; Huang, G; Zhang, H; Ye, S

2000-07-01

To explore the effects of the new gasoline additive, methyl tertiary butyl ether (MTBE) on cell cycle and cell apoptosis. Flow cytometry was used to evaluate the effect of MTBE (1, 2, 4 microl/ml, 24 h) on NIH/3T3 cell cycles; and the effect of MTBE on Hela cell apoptosis was evaluated by detecting cell survival using crystal violet staining. Flow cytometry showed that MTBE could change NIH/3T3 cell cycles, decrease the number of cells in S stage, and arrest cells at G(2) + M stage. The results suggested that MTBE could affect NIH/3T3 cell cycles and induce cell proliferation. This situation existed 48 hours after the treatment, and cell cycles came back normal 96 hours after the treatment. By detecting cell survival using crystal violet staining, we found that MTBE could inhibit the apoptosis of Hela cells which was induced by tumor necrosis factor (TNF)alpha and cycloheximide. MTBE's carcinogenicity to animals may relate to induction of cell proliferation and inhibition of cell apoptosis.

A Case-Control Study of Oral Epithelial Proliferative Markers among Sudanese Toombak Dippers Using Micronuclei Assay, Argyrophilic Nucleolar Organizer Region, Papanicolaou and Crystal Violet Methods

PubMed Central

Anass, M. Abbas; G. Ahmed, Hussain

2013-01-01

The use of Toombak has been reported to play a major role in the etiology of oral cancer in Sudan. The cellular proliferative activity on the oral epithelium of 210 Toombak dippers was assessed by applying the micronuclei frequency, mean argyrophilic nucleolar organizer region (AgNOR) counts, Papanicolaou method, and 1% crystal violet stain. Participants were divided into 3 groups: 200 were apparently healthy individuals, 100 were Toombak users (cases), 100 were non-tobacco users (control) and 10 were patients with oral squamous cell carcinomas. Cytological atypia was identified among 4 (4%). Toombak users and was not found among the control group (P<0.04). The micronuclei frequencies were higher in Toombak users (1.026) than in the control group (0.356) (P<0.0001). The mean AgNOR counts in Toombak users (2.423) were higher than control group (1.303) (P<0.0001). Neither Toombak users nor control group showed mitotic figures in 1% crystal violet method. The results of this research showed that Toombak dipping is a high risk factor for increase in the cellular proliferation in the oral mucosa. The cytological proliferative marker methods used are useful for screening Toombak users. PMID:24179643

Use of the gram stain in microbiology.

PubMed

Beveridge, T J

2001-05-01

The Gram stain differentiates bacteria into two fundamental varieties of cells. Bacteria that retain the initial crystal violet stain (purple) are said to be "gram-positive," whereas those that are decolorized and stain red with carbol fuchsin (or safranin) are said to be "gram-negative." This staining response is based on the chemical and structural makeup of the cell walls of both varieties of bacteria. Gram-positives have a thick, relatively impermeable wall that resists decolorization and is composed of peptidoglycan and secondary polymers. Gram-negatives have a thin peptidoglycan layer plus an overlying lipid-protein bilayer known as the outer membrane, which can be disrupted by decolorization. Some bacteria have walls of intermediate structure and, although they are officially classified as gram-positives because of their linage, they stain in a variable manner. One prokaryote domain, the Archaea, have such variability of wall structure that the Gram stain is not a useful differentiating tool.

GrB-TWEAK: A Potential Novel Biologic for NSCLC Therapy

DTIC Science & Technology

2015-09-01

72 hours. Cell viability was determined using the crystal violet staining method followed by solubilization of the dye in Sorenson’s buffer as...using the cationic dye JC-1 (JC-1 Assay Kit; MitoProbe) according to the manufacturer’s instructions, as previously described (8). For in vivo detection...mitochondrial depolarization (the loss of mitochondrial transmembrane potential as measured by green fluorescence of the JC-1 cationic dye in its

Opioid Use after TBI

DTIC Science & Technology

2013-07-01

hippocampal formation. b. Cresyl violet histochemistry Cresyl violet histological processing of tissue stains Nissl substance, which is composed mostly of...for:  Reactive glial response is being determined by measuring the luminance intensity of GFAP staining  Necrotic and apoptotic cell death by

Regulation of the Epithelial-Mesenchymal Transition in Prostate Cancer

DTIC Science & Technology

2013-06-01

removed by a cotton swab, and the cells on the lower surface of the membrane were stained by crystal violet. BD BioCoat Matrigel Invasion Chambers...PTK6 downstream players, including AKT, p130CAS, FAK, and ERK5. AKT signaling pro- motes the EMT in different cancer cell lines (23, 45, 46). PTK6...Yang R, Crawford SE, Vasioukhin V, Fuchs E, et al. Protein tyrosine kinase 6 negatively regulates growth and pro- motes enterocyte differentiation in

BIODEGRADATION OF CRYSTAL VIOLET BY THE WHITE ROT FUNGUS PHANEROCHAETE CHRYSOPORIUM

EPA Science Inventory

Biodegradation of crystal violet (N,N,N',N',N",N"-hexamethylpararosaniline) in ligninolytic (nitrogen-limited) cultures of the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance of crystal violet and by the identification of three metabolites (N,N,...

Potential of a lytic bacteriophage to disrupt Acinetobacter baumannii biofilms in vitro.

PubMed

Liu, Yannan; Mi, Zhiqiang; Niu, Wenkai; An, Xiaoping; Yuan, Xin; Liu, Huiying; Wang, Yong; Feng, Yuzhong; Huang, Yong; Zhang, Xianglilan; Zhang, Zhiyi; Fan, Hang; Peng, Fan; Li, Puyuan; Tong, Yigang; Bai, Changqing

2016-10-01

The ability of Acinetobacter baumannii to form biofilms and develop antibiotic resistance makes it difficult to control infections caused by this bacterium. In this study, we explored the potential of a lytic bacteriophage to disrupt A. baumannii biofilms. The potential of the lytic bacteriophage to disrupt A. baumannii biofilms was assessed by performing electron microscopy, live/dead bacterial staining, crystal violet staining and by determining adenosine triphosphate release. The bacteriophage inhibited the formation of and disrupted preformed A. baumannii biofilms. Results of disinfection assay showed that the lytic bacteriophage lysed A. baumannii cells suspended in blood or grown on metal surfaces. These results suggest the potential of the lytic bacteriophage to disrupt A. baumannii biofilms.

Fate of Bacterial and Viral Bio-Warfare Agents in Disinfected Waters

DTIC Science & Technology

2010-10-01

600 nm; approximately 4 h). An aliquot of 0.4 mL bacterial culture is spread onto the surface of Sporulation Media A Medium (SMA) and incubated at...dishes containing Sporulation Medium Sterile distilled water at 4 °C 70% EtOH Crystal violet Stain 1.2 Sporulation media A: Nutrient broth 8g/L...phase (approximately 4 h). 2.2 Seeding the Sporulation Plates 1. Label 150 mm Petri dishes of SM A Medium. 2. Inoculate, by aseptically spreading

Gram's Stain Does Not Cross the Bacterial Cytoplasmic Membrane.

PubMed

Wilhelm, Michael J; Sheffield, Joel B; Sharifian Gh, Mohammad; Wu, Yajing; Spahr, Christian; Gonella, Grazia; Xu, Bolei; Dai, Hai-Lung

2015-07-17

For well over a century, Hans Christian Gram's famous staining protocol has been the standard go-to diagnostic for characterizing unknown bacteria. Despite continuous and ubiquitous use, we now demonstrate that the current understanding of the molecular mechanism for this differential stain is largely incorrect. Using the fully complementary time-resolved methods: second-harmonic light-scattering and bright-field transmission microscopy, we present a real-time and membrane specific quantitative characterization of the bacterial uptake of crystal-violet (CV), the dye used in Gram's protocol. Our observations contradict the currently accepted mechanism which depicts that, for both Gram-negative and Gram-positive bacteria, CV readily traverses the peptidoglycan mesh (PM) and cytoplasmic membrane (CM) before equilibrating within the cytosol. We find that not only is CV unable to traverse the CM but, on the time-scale of the Gram-stain procedure, CV is kinetically trapped within the PM. Our results indicate that CV, rather than dyes which rapidly traverse the PM, is uniquely suited as the Gram stain.

Biofilm Formation of Staphylococcus aureus on Various Surfaces and Their Resistance to Chlorine Sanitizer.

PubMed

Lee, Jung-Su; Bae, Young-Min; Lee, Sook-Young; Lee, Sun-Young

2015-10-01

This study investigated the effect of material types (polystyrene, polypropylene, glass, and stainless steel) and glucose addition on Staphylococcus aureus biofilm formation, and the relationship between biofilm formation measured by crystal violet (CV) staining and the number of biofilm cells determined by cell counts was studied. We also evaluated the efficacy of chlorine sanitizer on inhibiting various different types of S. aureus biofilms on the surface of stainless steel. Levels of biofilm formation of S. aureus were higher on hydrophilic surfaces (glass and stainless steel) than on hydrophobic surfaces (polypropylene and polystyrene). With the exception of biofilm formed on glass, the addition of glucose in broth significantly increased the biofilm formation of S. aureus on all surfaces and for all tested strains (P ≤ 0.05). The number of biofilm cells was not correlated with the biomass of the biofilms determined using the CV staining method. The efficacy of chlorine sanitizer against biofilm of S. aureus was not significantly different depending on types of biofilm (P > 0.05). Therefore, further studies are needed in order to determine an accurate method quantifying levels of bacterial biofilm and to evaluate the resistance of bacterial biofilm on the material surface. Biofilm formation of Staphylococcus aureus on the surface was different depending on the surface characteristics and S. aureus strains. There was low correlation between crystal violet staining method and viable counts technique for measuring levels of biofilm formation of S. aureus on the surfaces. These results could provide helpful information for finding and understanding the quantification method and resistance of bacterial biofilm on the surface. © 2015 Institute of Food Technologists®

SU-F-T-676: Measurement of Hydroxyl Radicals in Radiolized Water Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouyang, Z; Ngwa, W; Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA

2016-06-15

Purpose: Hydroxyl radicals can be produced within tissue by radiation therapy, and they are largely responsible for DNA damage and cell killing. Coumarin-3-carboxylic acid (3-CCA) and crystal violet are reported to react with hydroxyl radicals and can be used for fluorescence and absorbance measurements, respectively. This study assesses the ability of hydroxyl measurement for both 3-CCA and crystal violet in radiolized water systems in order to provide dosimetric information in radiation chemistry and radiation biology experiments. Methods: 3-CCA and crystal violet were both dissolved in phosphate buffered saline (PBS, pH 7.4) with final concentrations 0.5 mg/mL and 0.05 mg/mL. 3-CCAmore » and control solutions (PBS only) were loaded in black bottom 96-well plates. Crystal violet and control solutions were loaded in clear bottom 96-well plates. The prepared solutions were irradiated at 2 Gy using a small animal radiation research platform. Fluorescence reading with 360 nm excitation wavelength and 485 nm emission wavelength was done for 3-CCA, and absorbance reading at wavelength 580 nm was done for crystal violet before and after radiation. Results: 3-CCA showed clear difference in fluorescence before and after radiation, which suggested hydroxyl production during radiation. However, crystal violet absorbance at 580 nm was not changed significantly by radiation. Conclusion: The overall conclusion is that 3-CCA can be used for hydroxyl measurement in radiolized water systems, while crystal violet cannot, although crystal violet is reported widely to react with hydroxyl radicals produced in Fenton reactions. Possible reasons could relate to reaction pH.« less

Inhibition and inactivation of Salmonella typhimurium biofilms from polystyrene and stainless steel surfaces by essential oils and phenolic constituent carvacrol.

PubMed

Soni, Kamlesh A; Oladunjoye, Ademola; Nannapaneni, Ramakrishna; Schilling, M Wes; Silva, Juan L; Mikel, Benjy; Bailey, R Hartford

2013-02-01

Persistence of Salmonella biofilms within food processing environments is an important source of Salmonella contamination in the food chain. In this study, essential oils of thyme and oregano and their antimicrobial phenolic constituent carvacrol were evaluated for their ability to inhibit biofilm formation and inactivate preformed Salmonella biofilms. A crystal violet staining assay and CFU measurements were utilized to quantify biofilm cell mass, with evaluating factors such as strain variation, essential oil type, their concentrations, exposure time, as well as biofilm formation surface. Of the three Salmonella strains, Salmonella Typhimurium ATCC 23564 and Salmonella Typhimurium ATCC 19585 produced stronger biofilms than Salmonella Typhimurium ATCC 14028. Biofilm formation by different Salmonella strains was 1.5- to 2-fold higher at 22°C than at 30 or 37°C. The presence of nonbiocidal concentrations of thyme oil, oregano oil, and phenolic carvacrol at 0.006 to 0.012% suppressed Salmonella spp. biofilm formation 2- to 4-fold, but could not completely eliminate biofilm formation. There was high correlation in terms of biofilm inactivation, as determined by the crystal violet-stained optical density (at a 562-nm wavelength) readings and the viable CFU counts. Reduction of biofilm cell mass was dependent on antimicrobial concentration. A minimum concentration of 0.05 to 0.1% of these antimicrobial agents was needed to reduce a 7-log CFU biofilm mass to a nondetectable level on both polystyrene and stainless steel surfaces within 1 h of exposure time.

Synergistic Effects of Sodium Chloride, Glucose, and Temperature on Biofilm Formation by Listeria monocytogenes Serotype 1/2a and 4b Strains ▿ † ‡

PubMed Central

Pan, Youwen; Breidt, Frederick; Gorski, Lisa

2010-01-01

Biofilm formation by Listeria monocytogenes is generally associated with its persistence in the food-processing environment. Serotype 1/2a strains make up more than 50% of the total isolates recovered from food and the environment, while serotype 4b strains are most often associated with major outbreaks of human listeriosis. Using a microplate assay with crystal violet staining, we examined biofilm formation by 18 strains of each serotype in tryptic soy broth with varying concentrations of glucose (from 0.25% to 10.0%, wt/vol), sodium chloride (from 0.5% to 7.0%, wt/vol) and ethanol (from 1% to 5.0%, vol/vol), and at different temperatures (22.5°C, 30°C, and 37°C). A synergistic effect on biofilm formation was observed for glucose, sodium chloride, and temperature. The serotype 1/2a strains generally formed higher-density biofilms than the 4b strains under most conditions tested. Interestingly, most serotype 4b strains had a higher growth rate than the 1/2a strains, suggesting that the growth rate may not be directly related to the capacity for biofilm formation. Crystal violet was found to stain both bacterial cells and biofilm matrix material. The enhancement in biofilm formation by environmental factors was apparently due to the production of extracellular polymeric substances instead of the accumulation of viable biofilm cells. PMID:20048067

A rapid method combining Golgi and Nissl staining to study neuronal morphology and cytoarchitecture.

PubMed

Pilati, Nadia; Barker, Matthew; Panteleimonitis, Sofoklis; Donga, Revers; Hamann, Martine

2008-06-01

The Golgi silver impregnation technique gives detailed information on neuronal morphology of the few neurons it labels, whereas the majority remain unstained. In contrast, the Nissl staining technique allows for consistent labeling of the whole neuronal population but gives very limited information on neuronal morphology. Most studies characterizing neuronal cell types in the context of their distribution within the tissue slice tend to use the Golgi silver impregnation technique for neuronal morphology followed by deimpregnation as a prerequisite for showing that neuron's histological location by subsequent Nissl staining. Here, we describe a rapid method combining Golgi silver impregnation with cresyl violet staining that provides a useful and simple approach to combining cellular morphology with cytoarchitecture without the need for deimpregnating the tissue. Our method allowed us to identify neurons of the facial nucleus and the supratrigeminal nucleus, as well as assessing cellular distribution within layers of the dorsal cochlear nucleus. With this method, we also have been able to directly compare morphological characteristics of neuronal somata at the dorsal cochlear nucleus when labeled with cresyl violet with those obtained with the Golgi method, and we found that cresyl violet-labeled cell bodies appear smaller at high cellular densities. Our observation suggests that cresyl violet staining is inadequate to quantify differences in soma sizes.

Pleural fluid Gram stain

MedlinePlus

Gram stain of pleural fluid ... mixing it with a violet stain (called a Gram stain). A laboratory specialist uses a microscope to ... reveals an abnormal collection of pleural fluid. The Gram stain can help identify the bacteria that might ...

Nature and origin of the violet stains on the walls of a Roman tomb.

PubMed

Dominguez-Moñino, Irene; Diaz-Herraiz, Marta; Jurado, Valme; Laiz, Leonila; Miller, Ana Z; Santos, Juan Luis; Alonso, Esteban; Saiz-Jimenez, Cesareo

2017-11-15

The Circular Mausoleum tomb (Roman Necropolis of Carmona, Spain) dates back from the first century AD and is characterized by a dense microbial (phototrophic) colonization on the walls and ceiling. However, some walls exhibited an important number of violet stains of unknown origin. The microbial communities of these violet stains are mainly composed of cyanobacteria, streptomycetes and fungi. A strain of Streptomyces parvus, isolated from the walls, produces a violet pigment in culture media. High performance liquid chromatography-mass spectrometry of the culture extracts obtained from this Streptomyces revealed the presence of a few granaticins, pigments with a benzoisochromanequinone structure. When metabolically active in the tomb, S. parvus synthesizes the pigments that diffuse into the mortar. During rain and/or wetting periods, the pigments are solubilized by alkaline waters and elute from the starting position to the surrounding mortar, enlarging the pigmented area and thus contributing to this exceptional biodeterioration phenomenon. Copyright © 2017 Elsevier B.V. All rights reserved.

Exposure to Crystal Violet, Its Toxic, Genotoxic and Carcinogenic Effects on Environment and Its Degradation and Detoxification for Environmental Safety.

PubMed

Mani, Sujata; Bharagava, Ram Naresh

2016-01-01

Crystal Violet (CV), a triphenylmethane dye, has been extensively used in human and veterinary medicine as a biological stain, as a textile dye in textile processing industries and also used to provide a deep violet color to paints and printing ink. CV is also used as a mutagenic and bacteriostatic agent in medical solutions and antimicrobial agent to prevent the fungal growth in poultry feed. Inspite of its many uses, CV has been reported as a recalcitrant dye molecule that persists in environment for a long period and pose toxic effects in environment. It acts as a mitotic poison, potent carcinogen and a potent clastogene promoting tumor growth in some species of fish. Thus, CV is regarded as a biohazard substance. Although, there are several physico-chemical methods such as adsorption, coagulation and ion-pair extraction reported for the removal of CV, but these methods are insufficient for the complete removal of CV from industrial wastewaters and also produce large quantity of sludge containing secondary pollutants. However, biological methods are regarded as cost-effective and eco-friendly for the treatment of industrial wastewaters, but these methods also have certain limitations. Therefore, there is an urgent need to develop such eco-friendly and cost-effective biological treatment methods, which can effectively remove the dye from industrial wastewaters for the safety of environment, as well as human and animal health.

Oxidation kinetics of crystal violet by potassium permanganate in acidic medium

NASA Astrophysics Data System (ADS)

Khan, Sameera Razi; Ashfaq, Maria; Mubashir; Masood, Summyia

2016-05-01

The oxidation kinetics of crystal violet (a triphenylmethane dye) by potassium permanganate was focused in an acidic medium by the spectrophotometric method at 584 nm. The oxidation reaction of crystal violet by potassium permanganate is carried out in an acidic medium at different temperatures ranging within 298-318 K. The kinetic study was carried out to investigate the effect of the concentration, ionic strength and temperature. The reaction followed first order kinetics with respect to potassium permanganate and crystal violet and the overall rate of the reaction was found to be second order. Thermodynamic activation parameters like the activation energy ( E a), enthalpy change (Δ H*), free energy change (Δ G*), and entropy change (Δ S*) have also been evaluated.

[Active carbon from Thalia dealbata residues: its preparation and adsorption performance to crystal violet].

PubMed

Chu, Shu-Yi; Yang, Min; Xiao, Ji-Bo; Zhang, Jun; Zhu, Yan-Ping; Yan, Xiang-Jun; Tian, Guang-Ming

2013-06-01

By using phosphoric acid as activation agent, active carbon was prepared from Thalia dealbata residues. The BET specific surface area of the active carbon was 1174.13 m2 x g(-1), micropore area was 426.99 m2 x g(-1), and average pore diameter was 3.23 nm. An investigation was made on the adsorption performances of the active carbon for crystal violet from aqueous solution under various conditions of pH, initial concentration of crystal violet, contact time, and contact temperature. It was shown that the adsorbed amount of crystal violet was less affected by solution pH, and the adsorption process could be divided into two stages, i. e., fast adsorption and slow adsorption, which followed the pseudo-second-order kinetics model. At the temperature 293, 303, and 313 K, the adsorption process was more accordance with Langmuir isotherm model, and the maximum adsorption capacity was 409.83, 425.53, and 438.59 mg x g(-1), respectively. In addition, the adsorption process was spontaneous and endothermic, and the randomness of crystal violet molecules increased.

[Biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5].

PubMed

Hu, Rong; Huang, Jian-Bo; Yang, Zhou-Ping; Cheng, Zi-Zhang; Jing, De-Jun; Huang, Qian-Ming

2011-12-01

With a shaker, this paper studied the characteristics of the biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5 under different adsorption time, initial pH, and temperature, as well as the desorption and recycling use of the dyes. The biosorption of crystal violet and malachite green by R. graminis Y-5 had the peaks (93.8% and 87.7%, respectively) at pH 7.0, dye concentration 50 mg x L(-1), 150 r x min(-1), 30 degrees C, and lasting 10 hours. After desorption, the biosorption rate of crystal violet and malachite green by R. graminis was 85.5% and 78.5%, respectively, indicating that the biosorption of crystal violet and malachite green was reversible, and the recycling use of the dyes by R. graminis was quite good, i. e., the dyes were renewable and could be recycled. Biosorption could be the mechanism of the decolorization of the dyes. The dyes were mostly adsorbed on the R. graminis surface -OH. The adsorption process was fast, efficient, and reversible, suggesting that R. graminis had a high potential for waste water treatment.

Capture Matrices Handbook

DTIC Science & Technology

2014-04-01

192–195. 2. I. Šafařik and M. Šafařikova.2002. “Detection of Low Concentrations of Malachite Green and Crystal Violet in Water,” Water Research 36... Malachite Green and Crystal Violet in Water,” Water Research 36:196–200. 5. F. P. Schwarz and S. P. Wasik. 1976. “Fluorescence Measurements of Benzene...Detection of Low Concentration of Malachite Green and Crystal Violet in Water,” Water Research 36:196–200. 3. Y. Lee, C.-L. Chang, and L.-M. Fu. 2011

Biochar pyrolyzed from MgAl-layered double hydroxides pre-coated ramie biomass (Boehmeria nivea (L.) Gaud.): Characterization and application for crystal violet removal.

PubMed

Tan, Xiao-Fei; Liu, Yun-Guo; Gu, Yan-Ling; Liu, Shao-Bo; Zeng, Guang-Ming; Cai, Xiaoxi; Hu, Xin-Jiang; Wang, Hui; Liu, Si-Mian; Jiang, Lu-Hua

2016-12-15

A novel biochar/MgAl-layered double hydroxides composite (CB-LDH) was prepared for the removal of crystal violet from aqueous solution by pyrolyzing MgAl-LDH pre-coated ramie stem (Boehmeria nivea (L.) Gaud.). Pyrolysis played dual role for both converting biomass into biochar and calcining MgAl-LDH during the pyrolysis process. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and zeta potential analysis were used to characterize the CB-LDH. The results of characterization suggested that the calcined LDH was successfully synthesized and coated on biochar. The resulted CB-LDH had higher total pore volume and more functional groups than the pristine biochar. Adsorption experimental data fitted well with the pseudo-second order kinetics model and the Freundlich isotherm model. The rate-controlled step was controlled by film-diffusion initially and then followed by intra-particle diffusion. Thermodynamic analysis showed that the adsorption of crystal violet was a spontaneous and endothermic process. The higher pH and temperature of the solution enhanced the adsorption performance. CB-LDH could also have excellent ability for the removal of crystal violet from the actual industrial wastewater and groundwater with high ionic strength. LDH adsorption, electrostatic attraction, pore-filling, π-π interaction and hydrogen bond might be the main mechanisms for crystal violet adsorption on CB-LDH. The results of this study indicated that CB-LDH is a sustainable and green adsorbent with high performance for crystal violet contaminated wastewater treatment and groundwater remediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detection of intracellular glutathione using ThiolTracker violet stain and fluorescence microscopy.

PubMed

Mandavilli, Bhaskar S; Janes, Michael S

2010-07-01

Glutathione plays an important role in protecting mammalian cells from oxidative stress and cell death. Because reduced glutathione (GSH) represents the large majority of intracellular free thiols, cell-permeant, thiol-reactive fluorescent probes represent potentially useful indicators of intracellular GSH. The ThiolTracker Violet stain (a registered trademark of Invitrogen) is a bright fluorescent probe that is highly reactive to thiols and can be used as a convenient and effective indicator of intracellular GSH and general redox status by a variety of detection modalities. While this probe has been validated in flow cytometry and microplate fluorimetry assays, the following method will describe details on the use of the ThiolTracker Violet dye in traditional fluorescence microscopy, as well as high-content imaging and analysis.

Quirks of dye nomenclature. 8. Methylene blue, azure and violet.

PubMed

Cooksey, C J

2017-01-01

Methylene blue was synthesized in 1877 and soon found application in medicine, staining for microscopy and as an industrial dye and pigment. An enormous literature has accumulated since its introduction. Early on, it was known that methylene blue could be degraded easily by demethylation; consequently, the purity of commercial samples often was low. Therefore, demethylation products, such as azures and methylene violet, also are considered here. The names and identity of the components, their varying modes of manufacture, analytical methods and their contribution to biological staining are discussed.

Adsorption of Crystal Violet Dye Using Zeolite A Synthesized From Coal Fly Ash

NASA Astrophysics Data System (ADS)

Jumaeri; Kusumastuti, E.; Santosa, S. J.; Sutarno

2017-02-01

Adsorption of Crystal Violet (CV) dye using zeolite A synthesized from coal fly ash (ZA) has been done. Effect of pH, contact time, and the initial concentration of dye adsorption was studied in this adsorption. Model experimental of adsorption isotherms and adsorption kinetics were also studied. The adsorption is done in a batch reactor at room temperature. A total of 0.01 g of zeolite A was added to the Erlenmeyer flask 50 mL containing 20 mL of the dye solution of Crystal Violet in a variety of conditions of pH, contact time and initial concentration. Furthermore, Erlenmeyer flask and its contents were shaken using an orbital shaker at a speed of 200 rpm. After a specified period of adsorption, the solution was centrifuged for 2 minutes so that the solids separated from the solution. The concentration of the dye after adsorption determined using Genesis-20 Spectrophotometer. The results showed that the Zeolite A synthesized from coal fly ash could be used as an effective adsorbent for Crystal Violet dye. The optimum adsorption occurs at pH 6, and contact time 45 minutes. At the initial concentration of 2 to 6 mg/L, adsorption is reduced from 79 to 62.8%. Crystal Violet dye adsorption in zeolite A fulfilled kinetic model of pseudo-order 2 and model of Freundlich adsorption isotherm.

Improving Student Results in the Crystal Violet Chemical Kinetics Experiment

ERIC Educational Resources Information Center

Kazmierczak, Nathanael; Vander Griend, Douglas A.

2017-01-01

Despite widespread use in general chemistry laboratories, the crystal violet chemical kinetics experiment frequently suffers from erroneous student results. Student calculations for the reaction order in hydroxide often contain large asymmetric errors, pointing to the presence of systematic error. Through a combination of "in silico"…

A Rapid Method Combining Golgi and Nissl Staining to Study Neuronal Morphology and Cytoarchitecture

PubMed Central

Pilati, Nadia; Barker, Matthew; Panteleimonitis, Sofoklis; Donga, Revers; Hamann, Martine

2008-01-01

The Golgi silver impregnation technique gives detailed information on neuronal morphology of the few neurons it labels, whereas the majority remain unstained. In contrast, the Nissl staining technique allows for consistent labeling of the whole neuronal population but gives very limited information on neuronal morphology. Most studies characterizing neuronal cell types in the context of their distribution within the tissue slice tend to use the Golgi silver impregnation technique for neuronal morphology followed by deimpregnation as a prerequisite for showing that neuron's histological location by subsequent Nissl staining. Here, we describe a rapid method combining Golgi silver impregnation with cresyl violet staining that provides a useful and simple approach to combining cellular morphology with cytoarchitecture without the need for deimpregnating the tissue. Our method allowed us to identify neurons of the facial nucleus and the supratrigeminal nucleus, as well as assessing cellular distribution within layers of the dorsal cochlear nucleus. With this method, we also have been able to directly compare morphological characteristics of neuronal somata at the dorsal cochlear nucleus when labeled with cresyl violet with those obtained with the Golgi method, and we found that cresyl violet–labeled cell bodies appear smaller at high cellular densities. Our observation suggests that cresyl violet staining is inadequate to quantify differences in soma sizes. (J Histochem Cytochem 56:539–550, 2008) PMID:18285350

Extractive biodecolorization of triphenylmethane dyes in cloud point system by Aeromonas hydrophila DN322p.

PubMed

Pan, Tao; Ren, Suizhou; Xu, Meiying; Sun, Guoping; Guo, Jun

2013-07-01

The biological treatment of triphenylmethane dyes is an important issue. Most microbes have limited practical application because they cannot completely detoxicate these dyes. In this study, the extractive biodecolorization of triphenylmethane dyes by Aeromonas hydrophila DN322p was carried out by introducing the cloud point system. The cloud point system is composed of a mixture of nonionic surfactants (20 g/L) Brij 30 and Tergitol TMN-3 in equal proportions. After the decolorization of crystal violet, a higher wet cell weight was obtained in the cloud point system than that of the control system. Based on the results of thin-layer chromatography, the residual crystal violet and its decolorized product, leuco crystal violet, preferred to partition into the coacervate phase. Therefore, the detoxification of the dilute phase was achieved, which indicated that the dilute phase could be discharged without causing dye pollution. The extractive biodecolorization of three other triphenylmethane dyes was also examined in this system. The decolorization of malachite green and brilliant green was similar to that of crystal violet. Only ethyl violet achieved a poor decolorization rate because DN322p decolorized it via adsorption but did not convert it into its leuco form. This study provides potential application of biological treatment in triphenylmethane dye wastewater.

Comparative analysis of quantitative methodologies for Vibrionaceae biofilms.

PubMed

Chavez-Dozal, Alba A; Nourabadi, Neda; Erken, Martina; McDougald, Diane; Nishiguchi, Michele K

2016-11-01

Multiple symbiotic and free-living Vibrio spp. grow as a form of microbial community known as a biofilm. In the laboratory, methods to quantify Vibrio biofilm mass include crystal violet staining, direct colony-forming unit (CFU) counting, dry biofilm cell mass measurement, and observation of development of wrinkled colonies. Another approach for bacterial biofilms also involves the use of tetrazolium (XTT) assays (used widely in studies of fungi) that are an appropriate measure of metabolic activity and vitality of cells within the biofilm matrix. This study systematically tested five techniques, among which the XTT assay and wrinkled colony measurement provided the most reproducible, accurate, and efficient methods for the quantitative estimation of Vibrionaceae biofilms.

Automated single-slide staining device. [in clinical bacteriology

NASA Technical Reports Server (NTRS)

Wilkins, J. R.; Mills, S. M.

1975-01-01

An automatic single-slide Gram staining device is described. A timer-actuated solenoid controls the dispensing of gentian violet, Gram iodine solution, decolorizer, and 1% aqueous safranin in proper sequence and for the time required for optimum staining. The amount of stain or reagent delivered is controlled by means of stopcocks below each solenoid. Used stains and reagents can be flushed automatically or manually. Smears Gram stained automatically are equal in quality to those prepared manually. The time to complete one Gram cycle is 4.80 min.

Terrific Trichomes (and Other Specialised Cells) in African Violets: How to Get a Lot from One Plant in the Classroom

ERIC Educational Resources Information Center

Cottrell, Vicki M.

2013-01-01

African violet (genus "Saintpaulia") was identified as a particularly suitable genus for the study of specialised plant cells in the classroom using microscopes. The techniques described here involve simple preparation without staining. The cells and structures that can be investigated include: trichomes (hairs); stomata; guard cells and…

Adsorption of crystal violet onto functionalised multi-walled carbon nanotubes: Equilibrium and kinetic studies.

PubMed

Sabna, V; Thampi, Santosh G; Chandrakaran, S

2016-12-01

Synthetic dyes present in effluent from textile, paper and paint industries contain crystal violet (CV), a known carcinogenic agent. This study investigates the modification of multiwalled carbon nanotubes by acid reflux method and equilibrium and kinetic behaviour of adsorption of CV onto functionalized multi-walled carbon nanotubes (fMWNTs) in batch system. High stability of the fMWNTs suspension in water indicates the hydrophilicity of fMWNTs induced due to the formation of functional groups that make hydrogen bonds with water molecules. fMWNTs were characterized by Fourier Transform Infra Red (FTIR) spectroscopy and the functional groups present on the fMWNTs were confirmed. Characteristic variation was observed in the FTIR spectra of fMWNTs after adsorption of crystal violet onto it. Adsorption characteristics were evaluated as a function of system variables such as contact time, dosage of fMWNTs and initial concentration and pH of the crystal violet solution. Adsorption capacity of fMWNTs and percentage removal of the dye increased with increase in contact time, adsorbent dosage and pH but declined with increase in initial concentration of the dye. fMWNTs showed higher adsorption capacity compared to that of pristine MWNTs. Data showed good fit with the Langmuir and Freundlich isotherm models and the pseudo-second order kinetic model; the maximum adsorption capacity was 90.52mg/g. Kinetic parameters such as rate constants, equilibrium adsorption capacities and regression coefficients were estimated. Results indicate that fMWNTs are an effective adsorbent for the removal of crystal violet from aqueous solution. Copyright © 2015 Elsevier Inc. All rights reserved.

Phelligridin D-loaded oral nanotube titanium implant enhances osseointegration and prevents osteolysis in rat mandible.

PubMed

Kim, Ji-Eun; Takanche, Jyoti Shrestha; Kim, Jeong-Seok; Lee, Min-Ho; Jeon, Jae-Gyu; Park, Il-Song; Yi, Ho-Keun

2018-04-12

Poor bone quality and osteolysis are the major causes of implant failure in dentistry. Here, this study tested the effect of phelligridin D-loaded nanotubes titanium (Ti) for bone formation around the dental implants. The purpose of this study was to enhance osseointegration of phelligridin D-loaded implant into the bone for bone formation and prevention of osteolysis. Cell viability, crystal violet staining, Western blot, alizarin red S staining, alkaline phosphatase activity, tartrate-resistant acid phosphatase staining, micro-computed tromography (μ-CT), hematoxylin and eosin (H&E) and immunohistochemical staining were used in vitro and in vivo to test the biocompatibility of phelligridin D. Phelligridin D enhanced osteoblast differentiation and mineralization by increasing bone morphogenic protein-2/7 (BMP-2/7), Osterix, Runx-2, osteoprotegerin (OPG), alkaline phosphatase and inhibited osteoclast differentiation by decreasing receptor activator of nuclear factor kappa-B ligand (RANKL) in MC-3T3 E1 cells. Further, phelligridin D promoted bone regeneration around nanotube Ti implant surface by increasing the levels of BMP-2/7 and OPG in a rat model. Phelligridin D also inhibited osteolysis by suppressing the expression of RANKL. These findings strongly suggest that phelligridin D is a new compound representing a potential therapeutic candidate for implant failure caused by osteolysis and poor bone quality of teeth.

Isolation and Applications of Prostate Side Population Cells Based on Dye Cycle Violet Efflux

PubMed Central

Gangavarapu, Kalyan J.; Huss, Wendy J.

2011-01-01

This unit describes methods for the digestion of human prostate clinical specimens, dye cycle violet (DCV) staining procedure for the identification, isolation, and quantitation of radiolabeled dihydrotestosterone (DHT) retention of side population cells. The principle of the side population assay is based on differential efflux of DCV, a cell membrane permeable fluorescent dye, by cells with high ATP binding cassette (ABC) transporter activity. Cells with high ABC transporter activity efflux DCV and fall in the lower left quadrant of a flow cytograph are designated as “side population” cells. This unit emphasizes tissue digestion, DCV staining, flow settings for sorting side population cells and quantitation of radiolabeled DHT retention. PMID:21400686

Sensitive detection of malachite green and crystal violet by nonlinear laser wave mixing and capillary electrophoresis.

PubMed

Maxwell, Eric J; Tong, William G

2016-05-01

An ultrasensitive label-free antibody-free detection method for malachite green and crystal violet is presented using nonlinear laser wave-mixing spectroscopy and capillary zone electrophoresis. Wave-mixing spectroscopy provides a sensitive absorption-based detection method for trace analytes. This is accomplished by forming dynamic gratings within a sample cell, which diffracts light to create a coherent laser-like signal beam with high optical efficiency and high signal-to-noise ratio. A cubic dependence on laser power and square dependence on analyte concentration make wave mixing sensitive enough to detect molecules in their native form without the use of fluorescent labels for signal enhancement. A 532 nm laser and a 635 nm laser were used for malachite green and crystal violet sample excitation. The use of two lasers of different wavelengths allows the method to simultaneously detect both analytes. Selectivity is obtained through the capillary zone electrophoresis separation, which results in characteristic migration times. Measurement in capillary zone electrophoresis resulted in a limit of detection of 6.9 × 10(-10)M (2.5 × 10(-19) mol) for crystal violet and 8.3 × 10(-11)M (3.0 × 10(-20) mol) for malachite green at S/N of 2. Copyright © 2016. Published by Elsevier B.V.

Assembly of potassium niobate nanosheets/silver oxide composite films with good SERS performance towards crystal violet detection

NASA Astrophysics Data System (ADS)

Zhu, Kun; Hong, Zhen; Kang, Shi-Zhao; Qin, Lixia; Li, Guodong; Li, Xiangqing

2018-04-01

The orderly potassium niobate nanosheets/silver oxide (Ag2O) composite films with uniform morphology were achieved by layer-by-layer self-assembly combined with ultraviolet light irradiation. The composition, structure and morphology of the potassium niobate nanosheets/Ag2O composite films were studied by XPS, XRD and SEM. Furthermore, the films were used as a SERS probe to detect crystal violet molecules. The results showed that the potassium niobate nanosheets/Ag2O composite films were an active substrate for fast and sensitive detection of crystal violet with low concentration. The limit of detection by the films can reach 1 × 10-6 mol L-1. Both electromagnetic enhancement and chemical enhancement contributed to the enhanced SERS in the (potassium niobate nanosheets/Ag2O)4 films. Moreover, it was found that the films were relatively stable under light irradiation or heat treatment in a certain range.

Combined histochemical staining, RNA amplification, regional, and single cell cDNA analysis within the hippocampus.

PubMed

Ginsberg, Stephen D; Che, Shaoli

2004-08-01

The use of five histochemical stains (cresyl violet, thionin, hematoxylin & eosin, silver stain, and acridine orange) was evaluated in combination with an expression profiling paradigm that included regional and single cell analyses within the hippocampus of post-mortem human brains and adult mice. Adjacent serial sections of human and mouse hippocampus were labeled by histochemistry or neurofilament immunocytochemistry. These tissue sections were used as starting material for regional and single cell microdissection followed by a newly developed RNA amplification procedure (terminal continuation (TC) RNA amplification) and subsequent hybridization to custom-designed cDNA arrays. Results indicated equivalent levels of global hybridization signal intensity and relative expression levels for individual genes for hippocampi stained by cresyl violet, thionin, and hematoxylin & eosin, and neurofilament immunocytochemistry. Moreover, no significant differences existed between the Nissl stains and neurofilament immunocytochemistry for individual CA1 neurons obtained via laser capture microdissection. In contrast, a marked decrement was observed in adjacent hippocampal sections stained for silver stain and acridine orange, both at the level of the regional dissection and at the CA1 neuron population level. Observations made on the cDNA array platform were validated by real-time qPCR using primers directed against beta-actin and glyceraldehyde-3 phosphate dehydrogenase. Thus, this report demonstrated the utility of using specific Nissl stains, but not stains that bind RNA species directly, in both human and mouse brain tissues at the regional and cellular level for state-of-the-art molecular fingerprinting studies.

Improved panels for clinical immune phenotyping: Utilization of the violet laser.

PubMed

Ryherd, Mark; Plassmeyer, Matthew; Alexander, Connor; Eugenio, Ines; Kleschenko, Yuliya; Badger, Ariel; Gupta, Raavi; Alpan, Oral; Sønder, Søren Ulrik

2017-05-10

Clinical diagnostic laboratories are subject to numerous regulations imposed by government agencies. Laboratory developed tests for flow cytometry panels are essentially restricted to the use of analyte-specific reagents (ASR) antibodies. With the advances in clinical flow cytometry systems, there is a trend toward the utilization of blue/red/violet laser flow systems and 8 to 10-color panels. Currently, the selection of commercially available ASR antibodies for the violet laser is very limited. The market is dominated by Brilliant Violet 421 (BV421) manufactured by BD Biosciences and Pacific Blue (PB) manufactured by Beckman Coulter. In this study, we compare BV421 and PB conjugated ASR antibodies. Whole blood was stained and acquired on a Gallios flow cytometer system. For single color staining, the stain index (SI) was calculated. For the two panels, the compensation matrix was calculated and the performance of the antibody cocktails analyzed in FCS Express. The results show that five out of six tested BV421 conjugated antibodies have significantly higher SI than their PB counterparts. Furthermore, BV421 antibodies require less compensation for spillover than PB. Finally, BV421 conjugated antibodies give better separation between negative and positive populations in the context of an 8 and 10 color panel without affecting the intensity of the other dyes. Overall, using BV421 conjugated antibodies results in better separation between populations compared to PB conjugated antibodies without negatively affecting other fluorochromes in our panels. We conclude that the BV421 conjugated ASR antibodies are currently the better available option for clinical flow panels. © 2017 International Clinical Cytometry Society. © 2017 International Clinical Cytometry Society.

Adsorption of gentian violet dyes in aqueous solution on microporous AlPOs molecular sieves synthesized by ionothermal method

NASA Astrophysics Data System (ADS)

Fortas, W.; Djelad, A.; Hasnaoui, M. A.; Sassi, M.; Bengueddach, A.

2018-02-01

In this work, AlPO-34, like-chabazite (CHA) zeolite, was ionothermally prepared using the ionic liquid (IL), 1-ethyl-3-methylimidazolium chloride [EMIMCl], as solvent. The solids obtained were characterized by x-ray powder diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FTIR), thermal analysis (TG) and nitrogen adsorption/desorption at 77.3 K. The results show that the ionic liquid is occluded in the AlPO-34 framework and consequently it acts also as a structure-directing agent. The variation of chemical composition led to AlPO-34 materials with different crystal sizes and morphologies. The well crystallized AlPO-34 material was used as adsorbent for Crystal Violet (CV) dye removal from aqueous solutions. The effect of adsorption parameters such as pH and initial concentration were investigated. It was found that adsorption dyes is favorable at pH = 6. The adsorption isotherm data follow the Langmuir equation in which parameters are calculated. The selected AlPO-34 sample exhibited a high crystal violet dye removal of 46.08 mg g-1 at pH = 6.

Application of Micro-cloud point extraction for spectrophotometric determination of Malachite green, Crystal violet and Rhodamine B in aqueous samples

NASA Astrophysics Data System (ADS)

Ghasemi, Elham; Kaykhaii, Massoud

2016-07-01

A novel, green, simple and fast method was developed for spectrophotometric determination of Malachite green, Crystal violet, and Rhodamine B in water samples based on Micro-cloud Point extraction (MCPE) at room temperature. This is the first report on the application of MCPE on dyes. In this method, to reach the cloud point at room temperature, the MCPE procedure was carried out in brine using Triton X-114 as a non-ionic surfactant. The factors influencing the extraction efficiency were investigated and optimized. Under the optimized condition, calibration curves were found to be linear in the concentration range of 0.06-0.60 mg/L, 0.10-0.80 mg/L, and 0.03-0.30 mg/L with the enrichment factors of 29.26, 85.47 and 28.36, respectively for Malachite green, Crystal violet, and Rhodamine B. Limit of detections were between 2.2 and 5.1 μg/L.

Application of Micro-cloud point extraction for spectrophotometric determination of Malachite green, Crystal violet and Rhodamine B in aqueous samples.

PubMed

Ghasemi, Elham; Kaykhaii, Massoud

2016-07-05

A novel, green, simple and fast method was developed for spectrophotometric determination of Malachite green, Crystal violet, and Rhodamine B in water samples based on Micro-cloud Point extraction (MCPE) at room temperature. This is the first report on the application of MCPE on dyes. In this method, to reach the cloud point at room temperature, the MCPE procedure was carried out in brine using Triton X-114 as a non-ionic surfactant. The factors influencing the extraction efficiency were investigated and optimized. Under the optimized condition, calibration curves were found to be linear in the concentration range of 0.06-0.60mg/L, 0.10-0.80mg/L, and 0.03-0.30mg/L with the enrichment factors of 29.26, 85.47 and 28.36, respectively for Malachite green, Crystal violet, and Rhodamine B. Limit of detections were between 2.2 and 5.1μg/L. Copyright © 2016 Elsevier B.V. All rights reserved.

Post-column reaction for simultaneous analysis of chromatic and leuco forms of malachite green and crystal violet by high-performance liquid chromatography with photometric detection

USGS Publications Warehouse

Allen, J.L.; Meinertz, J.R.

1991-01-01

The chromatic and leuco forms of malachite green and crystal violet were readily separated and detected by a sensitive and selective high-performance liquid chromatographic procedure. The chromatic and leuco forms of the dyes were separated within 11 min on a C18 column with a mobile phase of 0.05 M sodium acetate and 0.05 M acetic acid in water (19%) and methanol (81%). A reaction chamber, containing 10% PbO2 in Celite 545, was placed between the column and the spectrophotometric detector to oxidize the leuco forms of the dyes to their chromatic forms. Chromatic and leuco malachite green were quantified by their absorbance at 618 nm; and chromatic and leuco Crystal Violet by their absorbance at 588 nm. Detection limits for chromatic and leuco forms of both dyes ranged from 0.12 to 0.28 ng. A linear range of 1 to 100 ng was established for both forms of the dyes.

Opioid use after TBI

DTIC Science & Technology

2012-07-01

of tissue stains Nissl substance, which is composed mostly of rough endoplasmic reticulum and is lost after neuronal injury or axonal degeneration...Carson, 1990). For cresyl violet histochemistry, tissue was rinsed and dried overnight before staining . Sections were dehydrated through graded...five minutes. Differentiation was timed such that both Nissl substance and cell nuclei were clearly visible. Slides were washed in graded alcohol and

The Inhibition of Escherichia coli Biofilm Formation by Gallium Nitrate-Modified Titanium.

PubMed

Zhu, Yuanyuan; Qiu, Yan; Chen, Ruiqi; Liao, Lianming

2015-08-01

Periprosthetic infections are notoriously difficult to treat due to biofilm formation. Previously, we reported that gallium-EDTA attached to PVC (polyvinyl chloride) surface could prevent bacterial colonization. Herein we examined the effect of this gallium-EDTA complex on Escherichia coli biofilm formation on titanium. It was clearly demonstrated that gallium nitrate significantly inhibited the growth and auto-aggregation of Escherichia coli. Furthermore, titanium with gallium-EDTA coating resisted bacterial colonization as indicated by crystal violet staining. When the chips were immersed in human serum and incubated at 37 °C, they demonstrated significant antimicrobial activity after more than 28 days of incubation. These findings indicate that gallium-EDTA coating of implants can result in a surface that can resist bacterial colonization. This technology holds great promise for the prevention and treatment of periprosthetic infections.

Crystal Violet Lactone Salicylaldehyde Hydrazone Zn(II) Complex: a Reversible Photochromic Material both in Solution and in Solid Matrix

PubMed Central

Li, Kai; Li, Yuanyuan; Tao, Jing; Liu, Lu; Wang, Lili; Hou, Hongwei; Tong, Aijun

2015-01-01

Crystal violet lactone (CVL) is a classic halochromic dye which has been widely used as chromogenic reagent in thermochromic and piezochromic systems. In this work, a very first example of CVL-based reversible photochromic compound was developed, which showed distinct color change upon UV-visible light irradiation both in solution and in solid matrix. Moreover, metal complex of CVL salicylaldehyde hydrozone was facilely synthesized, exhibiting reversible photochromic properties with good fatigue resistance. It was served as promising solid material for photo-patterning. PMID:26412101

Up-conversion media on basis single crystals BaY2F8 for UV and VUV solid state lasers

NASA Astrophysics Data System (ADS)

Pushkar, A. A.; Ouvarova, T. V.; Molchanov, V. N.

2007-04-01

Crystal BaY IIF 8 represents the big interest as the perspective active media for lasers ultra-violet (UV) and vacuumultra- violet (VUV) regions. For the decision of problems with solarization this media and a choice of sources pump it is offered to use up-conversion mechanisms pump with activators from rare-earth elements (RE). We have developed technology of grown of oriented monocrystals BaY IIF 8, have defined influence of orientation on growth rate and quality ofthe received monocrystals.

Cavity-enhanced frequency doubling from 795nm to 397.5nm ultra-violet coherent radiation with PPKTP crystals in the low pump power regime.

PubMed

Wen, Xin; Han, Yashuai; Bai, Jiandong; He, Jun; Wang, Yanhua; Yang, Baodong; Wang, Junmin

2014-12-29

We demonstrate a simple, compact and cost-efficient diode laser pumped frequency doubling system at 795 nm in the low power regime. In two configurations, a bow-tie four-mirror ring enhancement cavity with a PPKTP crystal inside and a semi-monolithic PPKTP enhancement cavity, we obtain 397.5nm ultra-violet coherent radiation of 35mW and 47mW respectively with a mode-matched fundamental power of about 110mW, corresponding to a conversion efficiency of 32% and 41%. The low loss semi-monolithic cavity leads to the better results. The constructed ultra-violet coherent radiation has good power stability and beam quality, and the system has huge potential in quantum optics and cold atom physics.

Enhanced tetrazolium violet reduction of Salmonella spp. by magnesium addition to the culture media.

PubMed

Junillon, Thomas; Morand, Lucie; Flandrois, Jean Pierre

2014-09-01

Tetrazolium salts (TTZ), such as tetrazolium violet (TV), have been widely used for microbiological studies. The formation of the colored formazan product due to bacterial reduction of the uncolored reagent is extensively exploited to stain cells or colonies in agar or on filters. But an important toxic effect of tetrazolium salts on bacteria exists that limits their use at high concentrations, impairing the efficient staining of the colonies. This is especially the case for Salmonella spp. where we observed, using a classic photometric approach and mathematical modeling of the growth, an important impact of tetrazolium violet on the apparent growth rate below the inhibitory concentration. In this study, we demonstrate that adding magnesium to the medium in the presence of TV leads to a significant increase in the apparent growth rate. Moreover, when higher TV concentrations are used which lead to total inhibition of Salmonella strains, magnesium addition to the culture media allows growth and TV reduction. This effect of magnesium may allow the use of higher TTZ concentrations in liquid growth media and enhance bacteria detection capabilities. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation of TiO2 photocatalyst performance for decolorization in the presence of hydrodynamic cavitation as hybrid AOP.

PubMed

Bethi, Bhaskar; Sonawane, S H; Rohit, G S; Holkar, C R; Pinjari, D V; Bhanvase, B A; Pandit, A B

2016-01-01

In this article, an acoustic cavitation engineered novel approach for the synthesis of TiO2, cerium and Fe doped TiO2 nanophotocatalysts is reported. The prepared TiO2, cerium and Fe doped TiO2 nanophotocatalysts were characterized by XRD and TEM analysis to evaluate its structure and morphology. Photo catalytic performance of undoped TiO2 catalyst was investigated for the decolorization of crystal violet dye in aqueous solution at pH of 6.5 in the presence of hydro dynamic cavitation. Effect of catalyst doping with Fe and Ce was also studied for the decolorization of crystal violet dye. The results shows that, 0.8% of Fe-doped TiO2 exhibits maximum photocatalytic activity in the decolorization study of crystal violet dye due to the presence of Fe in the TiO2 and it may acts as a fenton reagent. Kinetic studies have also been reported for the hybrid AOP (HAOP) that followed the pseudo first-order reaction kinetics. Copyright © 2015 Elsevier B.V. All rights reserved.

Bile Salt-induced Biofilm Formation in Enteric Pathogens: Techniques for Identification and Quantification.

PubMed

Nickerson, Kourtney P; Faherty, Christina S

2018-05-06

Biofilm formation is a dynamic, multistage process that occurs in bacteria under harsh environmental conditions or times of stress. For enteric pathogens, a significant stress response is induced during gastrointestinal transit and upon bile exposure, a normal component of human digestion. To overcome the bactericidal effects of bile, many enteric pathogens form a biofilm hypothesized to permit survival when transiting through the small intestine. Here we present methodologies to define biofilm formation through solid-phase adherence assays as well as extracellular polymeric substance (EPS) matrix detection and visualization. Furthermore, biofilm dispersion assessment is presented to mimic the analysis of events triggering release of bacteria during the infection process. Crystal violet staining is used to detect adherent bacteria in a high-throughput 96-well plate adherence assay. EPS production assessment is determined by two assays, namely microscopy staining of the EPS matrix and semi-quantitative analysis with a fluorescently-conjugated polysaccharide binding lectin. Finally, biofilm dispersion is measured through colony counts and plating. Positive data from multiple assays support the characterization of biofilms and can be utilized to identify bile salt-induced biofilm formation in other bacterial strains.

Species-specific characteristics of the biofilm generated in silicone tube: an in vitro study.

PubMed

Kim, Dong Ju; Park, Joo-Hee; Chang, Minwook

2018-04-03

To investigate characteristics of biofilm which is usually found in silicone tube for nasolacrimal duct surgery and can be the root of chronic bacterial infections eventually resulted in surgical failure. To form a biofilm, sterile silicone tube was placed in culture media of Staphylococcus aureus, Corynebacterium matruchotii, Pseudomonas aeruginosa, or Streptococcus pneumonia. Biofilms formed on these silicone tubes were fixed with 95% ethanol and stained with 0.1% crystal violet. After staining, the optical densities of biofilms were measured using spectrophotometer on a weekly basis for 12 weeks. Staphylococcus aureus group and Pseudomonas aeruginosa group formed significantly more amounts of biofilms compared to the control group. The maximum optical densities of the two groups were found on week 3-4 followed by a tendency of decrease afterwards. However, the amounts of biofilms formed in other groups of silicone tubes were not statistically significant from that of the control group. Bacterial species that could form biofilm on silicone tube included Staphylococcus aureus (week 3) and Pseudomonas aeruginosa (Week 4). It is important to first consider that the cause of infection around 1 month after silicone tube intubation can be Staphylococcus aureus and Pseudomonas aeruginosa.

Pathogenic features and characteristics of food borne pathogens biofilm: Biomass, viability and matrix.

PubMed

Lin, Shiqi; Yang, Ling; Chen, Gu; Li, Bing; Chen, Dingqiang; Li, Lin; Xu, Zhenbo

2017-10-01

Biofilm is a ubiquitous growth pattern of bacterial species survival but is notorious for its threat on public health and food contamination. Extensive studies of the biofilm structure, formation, quantification, quorum sensing system and underlying control strategies have been reported during the past decades. Insightful elucidation of the pathogenic features and characteristic of bacterial biofilm can facilitate in devising appropriate control strategies for biofilm eradication. Therefore, this review mainly summarized the pathogenic features of biofilms from food borne microorganisms, including the biomass (which could be quantified using crystal violet and fluorogenic dye Syto9 assays), viability (which could be determined by tetrazolium salts, fluorescein diacetate, resazurin staining and alamar blue assays) and matrix (which are commonly detected by dimethyl methylene blue and wheat germ agglutinin assays). In addition, three features were further compared with its particular benefits in specific application. Copyright © 2017 Elsevier Ltd. All rights reserved.

Halophilic microbial communities in deteriorated buildings.

PubMed

Adamiak, Justyna; Otlewska, Anna; Gutarowska, Beata

2015-10-01

Halophilic microorganisms were traditionally isolated from an aquatic environment. There has been little research conducted into halophiles inhabiting the terrestrial environment in which historic monuments deteriorate. Salt efflorescence deposited on the walls is an observed phenomenon on the surface of historic buildings, and would favour the growth of halophiles. However, some conditions have to be fulfilled in order for efflorescence to occur: (1) the presence of salts, (2) porosity, (3) a source of water. Salt crystallization influences the material structure (cracking, detachment, material loss), but active growth of halophilic microorganisms may be a serious threat to historic materials as well, leading to aesthetical changes such as coloured biofilms, orange to pink or even violet stains. This is why it is important to investigate halophilic microorganisms, taking into consideration both the environmental conditions they need to grow in, material characteristics they inhabit, the mechanisms they possess to cope with osmotic stress, and the methods that should be applied for their identification.

Biofilm Formation by Pseudomonas Species Onto Graphene Oxide-TiO2 Nanocomposite-Coated Catheters: In vitro Analysis

NASA Astrophysics Data System (ADS)

Deb, Ananya; Vimala, R.

The present study focuses on the development of an in vitro model system for biofilm growth by Pseudomonas aerouginosa onto small discs of foley catheter. Catheter disc used for the study was coated with graphene oxide-titanium oxide composite (GO-TiO2) and titanium oxide (TiO2) and characterized through XRD, UV-visible spectroscopy. Morphological analysis was done by scanning electron microscopy (SEM). The biofilm formed on the catheter surface was quantified by crystal violet (CV) staining method and a colorimetric assay (MTT assay) which involves the reduction of tetrazolium salt. The catheter coated with GO-TiO2 showed reduced biofilm growth in comparison to the TiO2-coated and uncoated catheter, thus indicating that it could be successfully used in coating biomedical devices to prevent biofilm formation which is a major cause of nosocomial infection.

Determination of residues of three triphenylmethane dyes and their metabolites (malachite green, leuco malachite green, crystal violet, leuco crystal violet, and brilliant green) in aquaculture products by LC/MS/MS: first action 2012.25.

PubMed

Hurtaud-Pessel, Dominique; Couëdor, Pierrick; Verdon, Eric; Dowell, Dawn

2013-01-01

During the AOAC Annual Meeting held from September 30 to October 3, 2012 in Las Vegas, NV, the Expert Review Panel (ERP) on Veterinary Drug Residues reviewed data for the method for determination of residues of three triphenylmethane dyes and their metabolites (malachite green, leuco malachite green, crystal violet, leuco crystal violet, and brilliant green) in aquaculture products by LC/MS/MS, previously published in the Journal of Chromatography A 1218, 1632-1645 (2006). The method data were reviewed and compared to the standard method performance requirements (SMPRs) found in SMPR 2009.001, published in AOAC's Official Methods of Analysis, 19th Ed. (2012). The ERP determined that the data were acceptable, and the method was approved AOAC Official First Action. The method uses acetonitrile to isolate the analyte from the matrix. Then determination is conducted by LCIMS/MS with positive electrospray ionization. Accuracy ranged from 100.1 to 109.8% for samples fortified at levels of 0.5, 0.75, 1.0, and 2.0 microg/kg. Precision ranged from 2.0 to 10.3% RSD for the intraday samples and 1.9 to 10.6% for the interday samples analyzed over 3 days. The described method is designed to accurately operate in the analytical range from 0.5 to 2 microg/kg, where the minimum required performance limit for laboratories has been fixed in the European Union at 2.0 microg/kg for these banned substances and their metabolites. Upper levels of concentrations (1-100 microg/kg) can be analyzed depending on the different optional calibrations used.

TRAIL-induced programmed necrosis as a novel approach to eliminate tumor cells

PubMed Central

2014-01-01

Background The cytokine TRAIL represents one of the most promising candidates for the apoptotic elimination of tumor cells, either alone or in combination therapies. However, its efficacy is often limited by intrinsic or acquired resistance of tumor cells to apoptosis. Programmed necrosis is an alternative, molecularly distinct mode of programmed cell death that is elicited by TRAIL under conditions when the classical apoptosis machinery fails or is actively inhibited. The potential of TRAIL-induced programmed necrosis in tumor therapy is, however, almost completely uncharacterized. We therefore investigated its impact on a panel of tumor cell lines of wide-ranging origin. Methods Cell death/viability was measured by flow cytometry/determination of intracellular ATP levels/crystal violet staining. Cell surface expression of TRAIL receptors was detected by flow cytometry, expression of proteins by Western blot. Ceramide levels were quantified by high-performance thin layer chromatography and densitometric analysis, clonogenic survival of cells was determined by crystal violet staining or by soft agarose cloning. Results TRAIL-induced programmed necrosis killed eight out of 14 tumor cell lines. Clonogenic survival was reduced in all sensitive and even one resistant cell lines tested. TRAIL synergized with chemotherapeutics in killing tumor cell lines by programmed necrosis, enhancing their effect in eight out of 10 tested tumor cell lines and in 41 out of 80 chemotherapeutic/TRAIL combinations. Susceptibility/resistance of the investigated tumor cell lines to programmed necrosis seems to primarily depend on expression of the pro-necrotic kinase RIPK3 rather than the related kinase RIPK1 or cell surface expression of TRAIL receptors. Furthermore, interference with production of the lipid ceramide protected all tested tumor cell lines. Conclusions Our study provides evidence that TRAIL-induced programmed necrosis represents a feasible approach for the elimination of tumor cells, and that this treatment may represent a promising new option for the future development of combination therapies. Our data also suggest that RIPK3 expression may serve as a potential predictive marker for the sensitivity of tumor cells to programmed necrosis and extend the previously established role of ceramide as a key mediator of death receptor-induced programmed necrosis (and thus as a potential target for future therapies) also to the tumor cell lines examined here. PMID:24507727

UV-vis, IR and 1H NMR spectroscopic studies and characterization of ionic-pair crystal violet-oxytetracycline

NASA Astrophysics Data System (ADS)

Orellana, Sandra; Soto, César; Toral, M. Inés

2010-01-01

The present study shows the formation and characterization of the ionic-pair between the antibiotic oxytetracycline and the dye crystal violet in ammonia solution pH 9.0 ± 0.2 extracted into chloroform. The characterization was demonstrated using UV-vis spectrophotometry, 1H NMR, measurement of relaxation times T1 and IR spectroscopy, using a comparison between the signals of individual pure compounds with the signals with the mixture CV-OTC in different alkaline media. The formation of ionic-pair was also corroborated by new signals and chemical shifts. (2D) NMR spectroscopy experiments show that the interaction is electrostatic.

Decolorization of Malachite Green and Crystal Violet by Waterborne Pathogenic Mycobacteria

PubMed Central

Jones, Jefferson J.; Falkinham III, Joseph O.

2003-01-01

Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium scrofulaceum, Mycobacterium marinum, and Mycobacterium chelonae tolerate high concentrations of the dyes malachite green and crystal violet. Cells of strains of those species decolorized (reduced) both malachite green and crystal violet. Because decolorized malachite green lacked antimicrobial activity, the resistance of these mycobacteria could be due, in part, to their ability to decolorize the dyes. Small amounts of malachite green and its reduced, decolorized product were detected in the lipid fraction of M. avium strain A5 cells grown in the presence of malachite green, suggesting that a minor component of resistance could be due to sequestering the dyes in the extensive mycobacterial cell surface lipid. The membrane fraction of M. avium strain A5 had at least a fivefold-higher specific decolorization rate than did the crude extract, suggesting that the decolorization activity is membrane associated. The malachite green-decolorizing activity of the membrane fraction of M. avium strain A5 was abolished by either boiling or proteinase exposure, suggesting that the decolorizing activity was due to a protein. Decolorization activity of membrane fractions was stimulated by ferrous ion and inhibited by dinitrophenol and metyrapone. PMID:12821489

Expansion of the scope of AOAC first action method 2012.25 - single-laboratory validation of triphenylmethane dye and leuco metabolite analysis in shrimp, tilapia, catfish, and salmon by LC-MS/MS

USDA-ARS?s Scientific Manuscript database

Prior to conducting a collaborative study of AOAC First Action 2012.25 LC-MS/MS analytical method for the determination of residues of three triphenylmethane dyes (malachite green, crystal violet, and brilliant green) and their metabolites (leucomalachite green and leucocrystal violet) in seafood, a...

Counterion dye staining of proteins in one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tryptic gel digestion of stained protein for mass spectrometry.

PubMed

Cong, Wei-Tao; Wang, Xu; Hwang, Sun-Young; Jin, Li-Tai; Choi, Jung-Kap

2012-01-01

A fast and matrix-assisted laser desorption/ionization mass spectrometry compatible protein staining method in one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis is described. It is based on the counterion dye staining method that employs oppositely charged two dyes, zincon and ethyl violet, to form an ion-pair complex. The protocol, including fixing, staining, and quick washing steps, can be completed in 1-1.5 h, depending upon gel thickness. It has the sensitivity comparable to the colloidal Coomassie Brilliant Blue G stain using phosphoric acid as a component of staining solution (4-8 ng). The counterion dye stain does not induce protein modifications that complicate interpretation of peptide mapping data from mass spectrometry. Considering the speed, sensitivity, and compatibility with mass spectrometry, the counterion dye stain may be more practical than any other dye-based protein stains for routine proteomic researches.

Expression and purification recombinant human dentin sialoprotein in Escherichia coli and its effects on human dental pulp cells.

PubMed

Yun, Ye-Rang; Kim, Hae-Won; Kang, Wonmo; Jeon, Eunyi; Lee, Sujin; Lee, Hye-Young; Kim, Cheol-Hwan; Jang, Jun-Hyeog

2012-05-01

Dentin sialoprotein (DSP) is cleaved from dentin sialophosphoprotein (DSPP) and most abundant dentinal non-collagenous proteins in dentin. DSP is believed to participate in differentiation and mineralization of cells. In this study, we first constructed recombinant human DSP (rhDSP) in Escherichia coli (E. coli) and investigated its odontoblastic differentiation effects on human dental pulp cells (hDPCs). Cell adhesion activity was measured by crystal violet assay and cell proliferation activity was measured by MTT assay. To assess mineralization activity of rhDSP, Alizarin Red S staining was performed. In addition, the mRNA levels of collagen type І (Col І), alkaline phosphatase (ALP), and osteocalcin (OCN) were measured due to their use as mineralization markers for odontoblast-/osteoblast-like differentiation of hDPCs. The obtained rhDSP in E. coli was approximately identified by SDS-PAGE and Western blot. Initially, rhDSP significantly enhanced hDPCs adhesion activity and proliferation (p<0.05). In Alizarin Red S staining, stained hDPCs increased in a time-dependent manner. This odontoblastic differentiation activity was also verified through mRNA levels of odontoblast-related markers. Here, we first demonstrated that rhDSP may be an important regulatory ECM in determining the hDPCs fate including cell adhesion, proliferation, and odontoblastic differentiation activity. These findings indicate that rhDSP can induce growth and differentiation on hDPCs, leading to improve tooth repair and regeneration. Copyright © 2012 Elsevier Inc. All rights reserved.

Distinction of Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts with a selection medium.

PubMed

Tsukatani, Tadayuki; Suenaga, Hikaru; Higuchi, Tomoko; Shiga, Masanobu; Noguchi, Katsuya; Matsumoto, Kiyoshi

2011-01-01

Bacteria are fundamentally divided into two groups: Gram-positive and Gram-negative. Although the Gram stain and other techniques can be used to differentiate these groups, some issues exist with traditional approaches. In this study, we developed a method for differentiating Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt} (WST-8) via 2-methyl-1,4-napthoquinone with a selection medium. We optimized the composition of the selection medium to allow the growth of Gram-negative bacteria while inhibiting the growth of Gram-positive bacteria. When the colorimetric viability assay was carried out in a selection medium containing 0.5µg/ml crystal violet, 5.0 µg/ml daptomycin, and 5.0µg/ml vancomycin, the reduction in WST-8 by Gram-positive bacteria was inhibited. On the other hand, Gram-negative bacteria produced WST-8-formazan in the selection medium. The proposed method was also applied to determine the Gram staining characteristics of bacteria isolated from various foodstuffs. There was good agreement between the results obtained using the present method and those obtained using a conventional staining method. These results suggest that the WST-8 colorimetric assay with selection medium is a useful technique for accurately differentiating Gram-positive and -negative bacteria.

Feasibility of a tetracycline-binding method for detecting synovial fluid basic calcium phosphate crystals.

PubMed

Rosenthal, Ann K; Fahey, Mark; Gohr, Claudia; Burner, Todd; Konon, Irina; Daft, Laureen; Mattson, Eric; Hirschmugl, Carol; Ryan, Lawrence M; Simkin, Peter

2008-10-01

Basic calcium phosphate (BCP) crystals are common components of osteoarthritis (OA) synovial fluid. Progress in understanding the role of these bioactive particles in clinical OA has been hampered by difficulties in their identification. Tetracyclines stain calcium phosphate mineral in bone. The aim of this study was to investigate whether tetracycline staining might be an additional or alternative method for identifying BCP crystals in synovial fluid. A drop of oxytetracycline was mixed with a drop of fluid containing synthetic or native BCP, calcium pyrophosphate dihydrate (CPPD), or monosodium urate (MSU) crystals and placed on a microscope slide. Stained and unstained crystals were examined by light microscopy, with and without a portable broad-spectrum ultraviolet (UV) pen light. A small set of characterized synovial fluid samples were compared by staining with alizarin red S and oxytetracycline. Synthetic BCP crystals in synovial fluid were quantified fluorimetrically using oxytetracycline. After oxytetracycline staining, synthetic and native BCP crystals appeared as fluorescent amorphous aggregates under UV light. Oxytetracycline did not stain CPPD or MSU crystals or other particulates. Oxytetracycline staining had fewer false-positive test results than did alizarin red S staining and could provide estimates of the quantities of synthetic BCP crystals in synovial fluid. With further validation, oxytetracycline staining may prove to be a useful adjunct or alternative to currently available methods for identifying BCP crystals in synovial fluid.

Enhanced photocatalytic performance of CeO2-TiO2 nanocomposite for degradation of crystal violet dye and industrial waste effluent

NASA Astrophysics Data System (ADS)

Zahoor, Mehvish; Arshad, Amara; Khan, Yaqoob; Iqbal, Mazhar; Bajwa, Sadia Zafar; Soomro, Razium Ali; Ahmad, Ishaq; Butt, Faheem K.; Iqbal, M. Zubair; Wu, Aiguo; Khan, Waheed S.

2018-03-01

This study presents the synthesis of CeO2-TiO2 nanocomposite and its potential application for the visible light-driven photocatalytic degradation of model crystal violet dye as well as real industrial waste water. The ceria-titania (CeO2-TiO2) nanocomposite material was synthesised using facile hydrothermal route without the assistance of any template molecule. As-prepared composite was characterised by SEM, TEM, HRTEM, XRD, XPS for surface features, morphological and crystalline characters. The formed nanostructures were determined to possess crystal-like geometrical shape and average size less than 100 nm. The as-synthesised nanocomposite was further investigated for their heterogeneous photocatalytic potential against the oxidative degradation of CV dye taken as model pollutant. The photo-catalytic performance of the as-synthesised material was evaluated both under ultra-violet as well as visible light. Best photocatalytic performance was achieved under visible light with complete degradation (100%) exhibited within 60 min of irradiation time. The kinetics of the photocatalytic process were also considered and the reaction rate constant for CeO2-TiO2 nanocomposite was determined to be 0.0125 and 0.0662 min-1 for ultra-violet and visible region, respectively. In addition, the as-synthesised nanocomposite demonstrated promising results when considered for the photo-catalytic degradation of coloured industrial waste water collected from local textile industry situated in Faisalabad region of Pakistan. Enhanced photo-catalytic performance of CeO2-TiO2 nanocomposite was proposed owing to heterostructure formation leading to reduced electron-hole recombination.

Topical gentian violet compared with nystatin oral suspension for the treatment of oropharyngeal candidiasis in HIV-1-infected participants.

PubMed

Mukherjee, Pranab K; Chen, Huichao; Patton, Lauren L; Evans, Scott; Lee, Anthony; Kumwenda, Johnstone; Hakim, James; Masheto, Gaerolwe; Sawe, Frederick; Pho, Mai T; Freedberg, Kenneth A; Shiboski, Caroline H; Ghannoum, Mahmoud A; Salata, Robert A

2017-01-02

Compare the safety and efficacy of topical gentian violet with that of nystatin oral suspension (NYS) for the treatment of oropharyngeal candidiasis in HIV-1-infected adults in resource-limited settings. Multicenter, open-label, evaluator-blinded, randomized clinical trial at eight international sites, within the AIDS Clinical Trials Group. Adult HIV-infected participants with oropharyngeal candidiasis, stratified by CD4 cell counts and antiretroviral therapy status at study entry, were randomized to receive either gentian violet (0.00165%, BID) or NYS (500 000 units, QID) for 14 days. Cure or improvement after 14 days of treatment. Signs and symptoms of oropharyngeal candidiasis were evaluated in an evaluator-blinded manner. The study was closed early per Data Safety Monitoring Board after enrolling 221 participants (target = 494). Among the 182 participants eligible for efficacy analysis, 63 (68.5%) in the gentian violet arm had cure or improvement of oropharyngeal candidiasis versus 61 (67.8%) in the NYS arm, resulting in a nonsizable difference of 0.007 (95% confidence interval: -0.129, 0.143). There was no sizable difference in cure rates between the two arms (-0.0007; 95% confidence interval: -0.146, 0.131). No gentian violet-related adverse events were noted. No sizable differences were identified in tolerance, adherence, quality of life, or acceptability of study drugs. In gentian violet arm, 61 and 39% of participants reported 'no' and 'mild-to-moderate' staining, respectively. Cost for medication procurement was significantly lower for gentian violet versus NYS (median $2.51 and 19.42, respectively, P = 0.01). Efficacy of gentian violet was not statistically different than NYS, was well tolerated, and its procurement cost was substantially less than NYS.

The cyclic-di-GMP diguanylate cyclase CdgA has a role in biofilm formation and exopolysaccharide production in Azospirillum brasilense.

PubMed

Ramírez-Mata, Alberto; López-Lara, Lilia I; Xiqui-Vázquez, Ma Luisa; Jijón-Moreno, Saúl; Romero-Osorio, Angelica; Baca, Beatriz E

2016-04-01

In bacteria, proteins containing GGDEF domains are involved in production of the second messenger c-di-GMP. Here we report that the cdgA gene encoding diguanylate cyclase A (CdgA) is involved in biofilm formation and exopolysaccharide (EPS) production in Azospirillum brasilense Sp7. Biofilm quantification using crystal violet staining revealed that inactivation of cdgA decreased biofilm formation. In addition, confocal laser scanning microscopy analysis of green-fluorescent protein-labeled bacteria showed that, during static growth, the biofilms had differential levels of development: bacteria harboring a cdgA mutation exhibited biofilms with considerably reduced thickness compared with those of the wild-type Sp7 strain. Moreover, DNA-specific staining and treatment with DNase I, and epifluorescence studies demonstrated that extracellular DNA and EPS are components of the biofilm matrix in Azospirillum. After expression and purification of the CdgA protein, diguanylate cyclase activity was detected. The enzymatic activity of CdgA-producing cyclic c-di-GMP was determined using GTP as a substrate and flavin adenine dinucleotide (FAD(+)) and Mg(2)(+) as cofactors. Together, our results revealed that A. brasilense possesses a functional c-di-GMP biosynthesis pathway. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Rapid screening of potential autophagic inductor agents using mammalian cell lines.

PubMed

Martins, Waleska K; Severino, Divinomar; Souza, Cleidiane; Stolf, Beatriz S; Baptista, Maurício S

2013-06-01

Recent progress in understanding the molecular basis of autophagy has demonstrated its importance in several areas of human health. Affordable screening techniques with higher sensitivity and specificity to identify autophagy are, however, needed to move the field forward. In fact, only laborious and/or expensive methodologies such as electron microscopy, dye-staining of autophagic vesicles, and LC3-II immunoblotting or immunoassaying are available for autophagy identification. Aiming to fulfill this technical gap, we describe here the association of three widely used assays to determine cell viability - Crystal Violet staining (CVS), 3-[4, 5-dimethylthiaolyl]-2, 5-diphenyl-tetrazolium bromide (MTT) reduction, and neutral red uptake (NRU) - to predict autophagic cell death in vitro. The conceptual framework of the method is the superior uptake of NR in cells engaging in autophagy. NRU was then weighted by the average of MTT reduction and CVS allowing the calculation of autophagic arbitrary units (AAU), a numeric variable that correlated specifically with the autophagic cell death. The proposed strategy is very useful for drug discovery, allowing the investigation of potential autophagic inductor agents through a rapid screening using mammalian cell lines B16-F10, HaCaT, HeLa, MES-SA, and MES-SA/Dx5 in a unique single microplate. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Neuronal density, size and shape in the human anterior cingulate cortex: a comparison of Nissl and NeuN staining.

PubMed

Gittins, Rebecca; Harrison, Paul J

2004-03-15

There are an increasing number of quantitative morphometric studies of the human cerebral cortex, especially as part of comparative investigations of major psychiatric disorders. In this context, the present study had two aims. First, to provide quantitative data regarding key neuronal morphometric parameters in the anterior cingulate cortex. Second, to compare the results of conventional Nissl staining with those observed after immunostaining with NeuN, an antibody becoming widely used as a selective neuronal marker. We stained adjacent sections of area 24b from 16 adult brains with cresyl violet or NeuN. We measured the density of pyramidal and non-pyramidal neurons, and the size and shape of pyramidal neurons, in laminae II, III, Va, Vb and VI, using two-dimensional counting methods. Strong correlations between the two modes of staining were seen for all variables. However, NeuN gave slightly higher estimates of neuronal density and size, and a more circular perikaryal shape. Brain pH was correlated with neuronal size, measured with both methods, and with neuronal shape. Age and post-mortem interval showed no correlations with any parameter. These data confirm the value of NeuN as a tool for quantitative neuronal morphometric studies in routinely processed human brain tissue. Absolute values are highly correlated between NeuN and cresyl violet stains, but cannot be interchanged. NeuN may be particularly useful when it is important to distinguish small neurons from glia, such as in cytoarchitectural studies of the cerebral cortex in depression and schizophrenia.

Comparative effect of a stannous fluoride toothpaste and a sodium fluoride toothpaste on a multispecies biofilm.

PubMed

Cheng, Xingqun; Liu, Jinman; Li, Jiyao; Zhou, Xuedong; Wang, Lijiang; Liu, Jiquan; Xu, Xin

2017-02-01

This paper aimed to compare the mode of action of a stannous fluoride-containing toothpaste with a conventional sodium fluoride-containing toothpaste on anti-biofilm properties. A three-species biofilm model that consists of Streptococcus mutans, Streptococcus sanguinis and Porphyromonas gingivalis was established to compare the anti-biofilm properties of a stannous fluoride-containing toothpaste (CPH), a conventional sodium fluoride-containing toothpaste (CCP) and a negative control (PBS). The 48h biofilms were subjected to two-minute episodes of treatment with test agents twice a day for 5 consecutive days. Crystal violet staining and XTT assays were used to evaluate the biomass and viability of the treated biofilm. Live/dead staining and bacteria/extracellular polysaccharides (EPS) double-staining were used to visualize the biofilm structure and to quantify microbial/extracellular components of the treated biofilms. Species-specific fluorescent in situ hybridization and quantitative polymerase chain reaction (qPCR) were used to analyze microbial composition of the biofilms after treatment. The biomass and viability of the biofilms were significantly reduced after CPH toothpaste treatment. The inhibitory effect was further confirmed by the live/dead staining. The EPS amounts of the three-species biofilm were significantly reduced by CCP and CPH treatments, and CPH toothpaste demonstrated significant inhibition on EPS production. More importantly, CPH toothpaste significantly suppressed S. mutans and P. gingvalis, and enriched S. sanguinis in the three-species biofilm. In all experiments CPH had a significantly greater effect than CCP (p<0.05) and CCP had a greater effect than PBS (p<0.05). Stannous fluoride-containing toothpaste not only showed better inhibitory effect against oral microbial biofilm, but was also able to modulate microbial composition within multi-species biofilm compared with conventional sodium fluoride-containing toothpaste. Copyright © 2016 Elsevier Ltd. All rights reserved.

Colorimetric Nucleic Acid Detection on Paper Microchip Using Loop Mediated Isothermal Amplification and Crystal Violet Dye.

PubMed

Roy, Sharmili; Mohd-Naim, Noor Faizah; Safavieh, Mohammadali; Ahmed, Minhaz Uddin

2017-11-22

Nucleic acid detection is of paramount importance in monitoring of microbial pathogens in food safety and infectious disease diagnostic applications. To address these challenges, a rapid, cost-effective label-free technique for nucleic acid detection with minimal instrumentations is highly desired. Here, we present paper microchip to detect and quantify nucleic acid using colorimetric sensing modality. The extracted DNA from food samples of meat as well as microbial pathogens was amplified utilizing loop-mediated isothermal amplification (LAMP). LAMP amplicon was then detected and quantified on a paper microchip fabricated in a cellulose paper and a small wax chamber utilizing crystal violet dye. The affinity of crystal violet dye toward dsDNA and positive signal were identified by changing the color from colorless to purple. Using this method, detection of Sus scrofa (porcine) and Bacillus subtilis (bacteria) DNA was possible at concentrations as low as 1 pg/μL (3.43 × 10 -1 copies/μL) and 10 pg/μL (2.2 × 10 3 copies/μL), respectively. This strategy can be adapted for detection of other DNA samples, with potential for development of a new breed of simple and inexpensive paper microchip at the point-of-need.

Light-Induced Fluorescence Modulation of Quantum Dot-Crystal Violet Conjugates: Stochastic Off-On-Off Cycles for Multicolor Patterning and Super-Resolution.

PubMed

Jung, Sungwook; Park, Joonhyuck; Bang, Jiwon; Kim, Jae-Yeol; Kim, Cheolhee; Jeon, Yongmoon; Lee, Seung Hwan; Jin, Ho; Choi, Sukyung; Kim, Bomi; Lee, Woo Jin; Pack, Chan-Gi; Lee, Jong-Bong; Lee, Nam Ki; Kim, Sungjee

2017-06-07

Photoswitching or modulation of quantum dots (QDs) can be promising for many fields that include display, memory, and super-resolution imaging. However, such modulations have mostly relied on photomodulations of conjugated molecules in QD vicinity, which typically require high power of high energy photons at UV. We report a visible light-induced facile modulation route for QD-dye conjugates. QD crystal violets conjugates (QD-CVs) were prepared and the crystal violet (CV) molecules on QD quenched the fluorescence efficiently. The fluorescence of QD-CVs showed a single cycle of emission burst as they go through three stages of (i) initially quenched "off" to (ii) photoactivated "on" as the result of chemical change of CVs induced by photoelectrons from QD and (iii) back to photodarkened "off" by radical-associated reactions. Multicolor on-demand photopatterning was demonstrated using QD-CV solid films. QD-CVs were introduced into cells, and excitation with visible light yielded photomodulation from "off" to "on" and "off" by nearly ten fold. Individual photoluminescence dynamics of QD-CVs was investigated using fluorescence correlation spectroscopy and single QD emission analysis, which revealed temporally stochastic photoactivations and photodarkenings. Exploiting the stochastic fluorescence burst of QD-CVs, simultaneous multicolor super-resolution localizations were demonstrated.

Delayed post-treatment with bone marrow-derived mesenchymal stem cells is neurorestorative of striatal medium-spiny projection neurons and improves motor function after neonatal rat hypoxia-ischemia.

PubMed

Cameron, Stella H; Alwakeel, Amr J; Goddard, Liping; Hobbs, Catherine E; Gowing, Emma K; Barnett, Elizabeth R; Kohe, Sarah E; Sizemore, Rachel J; Oorschot, Dorothy E

2015-09-01

Perinatal hypoxia-ischemia is a major cause of striatal injury and may lead to cerebral palsy. This study investigated whether delayed administration of bone marrow-derived mesenchymal stem cells (MSCs), at one week after neonatal rat hypoxia-ischemia, was neurorestorative of striatal medium-spiny projection neurons and improved motor function. The effect of a subcutaneous injection of a high-dose, or a low-dose, of MSCs was investigated in stereological studies. Postnatal day (PN) 7 pups were subjected to hypoxia-ischemia. At PN14, pups received treatment with either MSCs or diluent. A subset of high-dose pups, and their diluent control pups, were also injected intraperitoneally with bromodeoxyuridine (BrdU), every 24h, on PN15, PN16 and PN17. This permitted tracking of the migration and survival of neuroblasts originating from the subventricular zone into the adjacent injured striatum. Pups were euthanized on PN21 and the absolute number of striatal medium-spiny projection neurons was measured after immunostaining for DARPP-32 (dopamine- and cAMP-regulated phosphoprotein-32), double immunostaining for BrdU and DARPP-32, and after cresyl violet staining alone. The absolute number of striatal immunostained calretinin interneurons was also measured. There was a statistically significant increase in the absolute number of DARPP-32-positive, BrdU/DARPP-32-positive, and cresyl violet-stained striatal medium-spiny projection neurons, and fewer striatal calretinin interneurons, in the high-dose mesenchymal stem cell (MSC) group compared to their diluent counterparts. A high-dose of MSCs restored the absolute number of these neurons to normal uninjured levels, when compared with previous stereological data on the absolute number of cresyl violet-stained striatal medium-spiny projection neurons in the normal uninjured brain. For the low-dose experiment, in which cresyl violet-stained striatal medium-spiny neurons alone were measured, there was a lower statistically significant increase in their absolute number in the MSC group compared to their diluent controls. Investigation of behavior in another cohort of animals showed that delayed administration of a high-dose of bone marrow-derived MSCs, at one week after neonatal rat hypoxia-ischemia, improved motor function on the cylinder test. Thus, delayed therapy with a high- or low-dose of adult MSCs, at one week after injury, is effective in restoring the loss of striatal medium-spiny projection neurons after neonatal rat hypoxia-ischemia and a high-dose of MSCs improved motor function. Copyright © 2015 Elsevier Inc. All rights reserved.

Detection and identification of dyes in blue writing inks by LC-DAD-orbitrap MS.

PubMed

Sun, Qiran; Luo, Yiwen; Yang, Xu; Xiang, Ping; Shen, Min

2016-04-01

In the field of forensic questioned document examination, to identify dyes detected in inks not only provides a solid foundation for ink discrimination in forged contents identification, but also facilitates the investigation of ink origin or the study regarding ink dating. To detect and identify potential acid and basic dyes in blue writing inks, a liquid chromatography-diode array detection-Orbitrap mass spectrometry (LC-DAD-Orbitrap MS) method was established. Three sulfonic acid dyes (Acid blue 1, Acid blue 9 and Acid red 52) and six triphenylmethane basic dyes (Ethyl violet, Crystal violet, Methyl violet 2B, Basic blue 7, Victoria blue B and Victoria blue R) were employed as reference dyes for method development. Determination of the nine dyes was validated to evaluate the instrument performance, and it turned out to be sensitive and stable enough for quantification. The method was then applied in the screening analysis of ten blue roller ball pen inks and twenty blue ballpoint pen inks. As a result, including TPR (a de-methylated product of Crystal violet), ten known dyes and four unknown dyes were detected in the inks. The latter were further identified as a de-methylated product of Victoria blue B, Acid blue 104, Acid violet 49 and Acid blue 90, through analyzing their characteristic precursor and product ions acquired by Orbitrap MS with good mass accuracy. The results showed that the established method is capable of detecting and identifying potential dyes in blue writing inks. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Single-species microbial biofilm screening for industrial applications.

PubMed

Li, Xuan Zhong; Hauer, Bernhard; Rosche, Bettina

2007-10-01

While natural microbial biofilms often consist of multiple species, single-species biofilms are of great interest to biotechnology. The current study evaluates biofilm formation for common industrial and laboratory microorganisms. A total of 68 species of biosafety level one bacteria and yeasts from over 40 different genera and five phyla were screened by growing them in microtiter plates and estimating attached biomass by crystal violet staining. Most organisms showed biofilm formation on surfaces of polystyrene within 24 h. By changing a few simple conditions such as substratum characteristics, inoculum and nutrient availability, 66 strains (97%) demonstrated biofilm formation under at least one of the experimental conditions and over half of these strains were classified as strong biofilm formers, potentially suitable as catalysts in biofilm applications. Many non-motile bacteria were also strong biofilm formers. Biofilm morphologies were visualized for selected strains. A model organism, Zymomonas mobilis, easily established itself as a biofilm on various reactor packing materials, including stainless steel.

Venom present in sea anemone (Heteractis magnifica) induces apoptosis in non-small-cell lung cancer A549 cells through activation of mitochondria-mediated pathway.

PubMed

Ramezanpour, Mahnaz; da Silva, Karen Burke; Sanderson, Barbara J S

2014-03-01

Lung cancer is a major cause of cancer deaths throughout the world and the complexity of apoptosis resistance in lung cancer is apparent. Venom from Heteractis magnifica caused dose-dependent decreases in survival of the human non-small-cell lung cancer cell line, as determined by the MTT and Crystal Violet assays. The H. magnifica venom induced cell cycle arrest and induced apoptosis of A549 cells, as confirmed by annexin V/propidium iodide staining. The venom-induced apoptosis in A549 cells was characterized by cleavage of caspase-3 and a reduction in the mitochondrial membrane potential. Interestingly, crude extracts from H. magnifica had less effect on the survival of non-cancer cell lines. In the non-cancer cells, the mechanism via which cell death occurred was through necrosis not apoptosis. These findings are important for future work using H. magnifica venom for pharmaceutical development to treat human lung cancer.

Pseudomonas aeruginosa biofilm growth inhibition on medical plastic materials by immobilized esterases and acylase.

PubMed

Kisch, Johannes Martin; Utpatel, Christian; Hilterhaus, Lutz; Streit, Wolfgang R; Liese, Andreas

2014-09-05

Biofilms are matrix-encapsulated cell aggregates that cause problems in technical and health-related areas; for example, 65 % of all human infections are biofilm associated. This is mainly due to their ameliorated resistance against antimicrobials and immune systems. Pseudomonas aeruginosa, a biofilm-forming organism, is commonly responsible for nosocomial infections. Biofilm development is partly mediated by signal molecules, such as acyl-homoserine lactones (AHLs) in Gram-negative bacteria. We applied horse liver esterase, porcine kidney acylase, and porcine liver esterase; these can hydrolyze AHLs, thereby inhibiting biofilm formation. As biofilm infections are often related to foreign material introduced into the human body, we immobilized the enzymes on medical plastic materials. Biofilm formation was quantified by Crystal Violet staining and confocal laser scanning microscopy, revealing up to 97 % (on silicone), 54 % (on polyvinyl chloride), and 77 % (on polyurethane) reduced biomass after 68 h growth. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Salmonella enterica isolates from layer farm environments are able to form biofilm on eggshell surfaces.

PubMed

Pande, Vivek V; McWhorter, Andrea R; Chousalkar, Kapil K

2016-08-01

This study examined the eggshell biofilm forming ability of Salmonella enterica isolates recovered from egg farms. Multicellular behaviour and biofilm production were examined at 22 and 37°C by Congo red morphology and the crystal violet staining assay. The results indicated that the biofilm forming behaviour of Salmonella isolates was dependent on temperature and associated with serovars. Significantly greater biofilm production was observed at 22°C compared with 37°C. The number of viable biofilm cells attached to eggshells after incubation for 48 h at 22°C was significantly influenced by serovar. Scanning electron microscopic examination revealed firm attachment of bacterial cells to the eggshell surface. The relative expression of csgD and adrA gene was significantly higher in eggshell biofilm cells of S. Mbandaka and S. Oranienburg. These findings demonstrate that Salmonella isolates are capable of forming biofilm on the eggshell surface and that this behaviour is influenced by temperature and serovar.

Utilization of biogenic tea waste silver nanoparticles for the reduction of organic dyes

NASA Astrophysics Data System (ADS)

Kaur, H.; Jaryal, N.

2018-05-01

Eco-friendly synthesis of nanoparticles is the need of the society today. Present study has been undertaken to investigate the greener approach for the preparation of medicinally and chemically important nanoparticles. Tea waste has been taken to synthesis silver nanoparticles. The nanoparticles are characterized by x-ray Diffraction, and Transmission Emission Microscopy studies. The particle size varied from 2 to 34 nm. These silver nanoparticles were evaluated for their reducing activity against four organic dyes viz crystal violet, methylene blue, Congo red and brilliant green. The particles exhibited good catalytic activity against crystal violet, methylene blue and brilliant green but no activity was visible for Congo red. Furthermore, AgNPs shows very promising and prominent antioxidant activity.

Investigation of new dyes for chromovitrectomy: preclinical biocompatibility of trisodium, orangell and methyl violet.

PubMed

Badaro, Emmerson; Souza-Lima, Rodrigo A; Novais, Eduardo A; Maia, Mauricio; Hirai, Flávio; Meyer, Carsten H; Farah, Michel Eid; Rodrigues, Eduardo B

2015-01-01

To investigate the retinal toxicity by electroretinography (ERG), clinical examination and histology after intravitreal injection of biological stains in two concentrations: Trisodium (0.50 g/L and 1.00 g/L), Orangell (0.25 g/L and 1.00 g/L) and Methyl Violet (0.50 g/L and 1.00 g/L). Eighteen New-Zealand albinos rabbits were assigned in six groups (n = 3 in each group). The animals in group 1 received Trisodium in the dose of 0.50 g/L and group 2 received 1.00 g/L; Group 3 received Orangell in the dose of 0.25 g/L and group 4 received 1.00 g/L; Group 5 received Methyl Violet in the dose of 1.00 g/L and group 6 received 0.50 g/L. A volume of 0.05 mL of dye was injected in the right eyes, whereas the left eyes received the same volume of balanced salt solution (BSS) as control. ERG recordings and clinical examination were performed at baseline and seven days after intravitreal injection. The ERG responses at one week after injection were compared with baseline levels. A decrease in the post-injection amplitude of more than 50% was considered remarkable. After the 7-day follow-up, rabbits were euthanized and eye enucleated for light microscopy (LM) histological evaluation. At clinical examination by indirect ophthalmoscopy seven days after dye injection, all eyes were negative for cataract, hemorrhage, retinal detachment, and intraocular opacities. Amplitude analysis of maximum scotopic b-wave showed no significant reduction in either dye injected or control eyes. Neither dye nor BSS caused significant retinal alteration on LM at doses tested. Trisodium, Orangell and Methyl Violet can be applied in future studies in order to prove the capacity to stain preretinal tissues and vitreous without toxicity. The three dyes did not induce significant ERG amplitude reduction or LM alterations in this preliminary experimental research. Trisodium, Orangell and Methyl Violet may be potentially useful vital dyes for ocular surgery, and deserve further investigation.

Coupled adsorption-photocatalytic degradation of crystal violet under sunlight using chemically synthesized grafted sodium alginate/ZnO/graphene oxide composite.

PubMed

Mohamed, S K; Hegazy, Sh H; Abdelwahab, N A; Ramadan, A M

2018-03-01

This research aimed to synthesize natural polymer nanocomposite and employ it for coupled adsorption- photocatalytic degradation of crystal violet. Sodium alginate-g-poly (acrylic acid-co-cinnamic acid) and its composites with ZnO nanorods and graphene oxide sheets were synthesized and characterized using FT-IR, XRD, SEM, HR-TEM and DR/UV-vis spectroscopy. The adsorption efficiency of samples for crystal violet has been studied in the dark. The effect of different parameters as pH, initial dye concentration, contact time and temperature on the adsorption efficiency of the synthesized sample has been examined. Kinetics studies showed that the adsorption of all samples was well described by the pseudo-second-order model and the equilibrium adsorption results fitted Freundlich model. The maximum adsorption capacity achieved at pH 5.0 was 13.85 mg g -1 . Thermodynamic studies exhibited that the adsorption is spontaneous, endothermic in nature and leads to higher entropy. Coupled adsorption-photocatalytic degradation studies under sunlight showed an enhancement in the removal efficiency by 10%. In the case of sodium alginate-g-poly (acrylic acid-co-cinnamic acid)/ZnO/graphene oxide composite, the removal efficiency after 5 h under sunlight was 94% versus 84% in the dark. Copyright © 2017 Elsevier B.V. All rights reserved.

Biofilm formation, cellulose production, and curli biosynthesis by Salmonella originating from produce, animal, and clinical sources.

PubMed

Solomon, Ethan B; Niemira, Brendan A; Sapers, Gerald M; Annous, Bassam A

2005-05-01

The ability of 71 strains of Salmonella enterica originating from produce, meat, or clinical sources to form biofilms was investigated. A crystal violet binding assay demonstrated no significant differences in biofilm formation by isolates from any source when tested in any of the following three media: Luria-Bertani broth supplemented with 2% glucose, tryptic soy broth (TSB), or 1/20th-strength TSB. Incubation was overnight at 30 degrees C under static conditions. Curli production and cellulose production were monitored by assessing morphotypes on Luria-Bertani agar without salt containing Congo red and by assessing fluorescence on Luria-Bertani agar containing calcofluor, respectively. One hundred percent of the clinical isolates exhibited curli biosynthesis, and 73% demonstrated cellulose production. All meat-related isolates formed curli, and 84% produced cellulose. A total of 80% of produce-related isolates produced curli, but only 52% produced cellulose. Crystal violet binding was not statistically different between isolates representing the three morphotypes when grown in TSB; however, significant differences were observed when strains were cultured in the two other media tested. These data demonstrate that the ability to form biofilms is not dependent on the source of the test isolate and suggest a relationship between crystal violet binding and morphotype, with curli- and cellulose-deficient isolates being least effective in biofilm formation.

Violet laser diodes as light sources for cytometry.

PubMed

Shapiro, H M; Perlmutter, N G

2001-06-01

Violet laser diodes have recently become commercially available. These devices emit 5-25 mW in the range of 395-415 nm, and are available in systems that incorporate the diodes with collimating optics and regulated power supplies in housing incorporating thermoelectric coolers, which are necessary to maintain stable output. Such systems now cost several thousand dollars, but are expected to drop substantially in price. Materials and Methods A 4-mW, 397-nm violet diode system was used in a laboratory-built flow cytometer to excite fluorescence of DAPI and Hoechst dyes in permeabilized and intact cells. Forward and orthogonal light scattering were also measured. DNA content histograms with good precision (G(0)/G(1) coefficient of variation 1.7%) were obtained with DAPI staining; precision was lower using Hoechst 33342. Hoechst 34580, with an excitation maximum nearer 400 nm, yielded the highest fluorescence intensity, but appeared to decompose after a short time in solution. Scatter signals exhibited relatively broad distributions. Violet laser diodes are relatively inexpensive, compact, efficient, and quiet light sources for DNA fluorescence measurement using DAPI and Hoechst dyes; they can also excite several other fluorescent probes. Copyright 2001 Wiley-Liss, Inc.

Cell-cycle synchronisation of bloodstream forms of Trypanosoma brucei using Vybrant DyeCycle Violet-based sorting.

PubMed

Kabani, Sarah; Waterfall, Martin; Matthews, Keith R

2010-01-01

Studies on the cell-cycle of Trypanosoma brucei have revealed several unusual characteristics that differ from the model eukaryotic organisms. However, the inability to isolate homogenous populations of parasites in distinct cell-cycle stages has limited the analysis of trypanosome cell division and complicated the understanding of mutant phenotypes with possible impact on cell-cycle related events. Although hydroxyurea-induced cell-cycle arrest in procyclic and bloodstream forms has been applied recently with success, such block-release protocols can complicate the analysis of cell-cycle regulated events and have the potential to disrupt important cell-cycle checkpoints. An alternative approach based on flow cytometry of parasites stained with Vybrant DyeCycle Orange circumvents this problem, but is restricted to procyclic form parasites. Here, we apply Vybrant Dyecycle Violet staining coupled with flow cytometry to effectively select different cell-cycle stages of bloodstream form trypanosomes. Moreover, the sorted parasites remain viable, although synchrony is rapidly lost. This method enables cell-cycle enrichment of populations of trypanosomes in their mammal infective stage, particularly at the G1 phase.

Cell-cycle synchronisation of bloodstream forms of Trypanosoma brucei using Vybrant DyeCycle Violet-based sorting

PubMed Central

Kabani, Sarah; Waterfall, Martin; Matthews, Keith R.

2010-01-01

Studies on the cell-cycle of Trypanosoma brucei have revealed several unusual characteristics that differ from the model eukaryotic organisms. However, the inability to isolate homogenous populations of parasites in distinct cell-cycle stages has limited the analysis of trypanosome cell division and complicated the understanding of mutant phenotypes with possible impact on cell-cycle related events. Although hydroxyurea-induced cell-cycle arrest in procyclic and bloodstream forms has been applied recently with success, such block-release protocols can complicate the analysis of cell-cycle regulated events and have the potential to disrupt important cell-cycle checkpoints. An alternative approach based on flow cytometry of parasites stained with Vybrant DyeCycle Orange circumvents this problem, but is restricted to procyclic form parasites. Here, we apply Vybrant Dyecycle Violet staining coupled with flow cytometry to effectively select different cell-cycle stages of bloodstream form trypanosomes. Moreover, the sorted parasites remain viable, although synchrony is rapidly lost. This method enables cell-cycle enrichment of populations of trypanosomes in their mammal infective stage, particularly at the G1 phase. PMID:19729042

Adsorption of Crystal Violet on Activated Carbon Prepared from Coal Flotation Concentrate

NASA Astrophysics Data System (ADS)

Aydogmus, Ramazan; Depci, Tolga; Sarikaya, Musa; Riza Kul, Ali; Onal, Yunus

2016-10-01

The objective of this study is firstly to investigate the floatability properties of Zilan- Van coal after microwave irradiation and secondly to produce activated carbon from flotation concentrate in order to remove Crystal Violet (CV) from waste water. The flotation experiments showed that microwave heating at 0.9 kW power level for 60 sec exposure time enhanced the hydrophobicity and increased the flotation yield. The activated carbon with remarkable surface area (696 m2/g) was produced from the flotation concentrate and used to adsorb CV from aqueous solution in a batch reactor at different temperature. The adsorption properties of CV onto the activated carbon are discussed in terms of the adsorption isotherms (Langmuir and Freundlich) and found that the experimental results best fitted by the Langmuir model.

Capillary electrophoresis of chitooligosaccharides in acidic solution: simple determination using a quaternary-ammonium-modified column and indirect photometric detection with crystal violet.

PubMed

Hattori, Toshiaki; Anraku, Nobuhiro; Kato, Ryo

2010-02-01

Five chitosan oligosaccharides were separated in acidic aqueous solution by capillary electrophoresis (CE) with indirect photometric detection using a positively coated capillary. Electrophoretic mobility of the chitooligosaccharides (COSs) depended on the number of monomer units in acidic aqueous solution, similar to other polyelectrolyte oligomers. The separation was developed in nitric acid aqueous solution at pH 3.0 with 1 mM Crystal Violet, using a capillary positively coated with N-trimethoxypropyl-N,N,N-trimethylammonium chloride. The limit of the detection for chitooligosaccharides with two to six saccharide chains was less than 5 microM. CE determination of an enzymatically hydrolyzed COS agreed with results from HPLC. 2009 Elsevier B.V. All rights reserved.

Photo Inactivation of Streptococcus mutans Biofilm by Violet-Blue light.

PubMed

Gomez, Grace F; Huang, Ruijie; MacPherson, Meoghan; Ferreira Zandona, Andrea G; Gregory, Richard L

2016-09-01

Among various preventive approaches, non-invasive phototherapy/photodynamic therapy is one of the methods used to control oral biofilm. Studies indicate that light at specific wavelengths has a potent antibacterial effect. The objective of this study was to determine the effectiveness of violet-blue light at 380-440 nm to inhibit biofilm formation of Streptococcus mutans or kill S. mutans. S. mutans UA159 biofilm cells were grown for 12-16 h in 96-well flat-bottom microtiter plates using tryptic soy broth (TSB) or TSB with 1 % sucrose (TSBS). Biofilm was irradiated with violet-blue light for 5 min. After exposure, plates were re-incubated at 37 °C for either 2 or 6 h to allow the bacteria to recover. A crystal violet biofilm assay was used to determine relative densities of the biofilm cells grown in TSB, but not in TSBS, exposed to violet-blue light. The results indicated a statistically significant (P < 0.05) decrease compared to the non-treated groups after the 2 or 6 h recovery period. Growth rates of planktonic and biofilm cells indicated a significant reduction in the growth rate of the violet-blue light-treated groups grown in TSB and TSBS. Biofilm viability assays confirmed a statistically significant difference between violet-blue light-treated and non-treated groups in TSB and TSBS. Visible violet-blue light of the electromagnetic spectrum has the ability to inhibit S. mutans growth and reduce the formation of S. mutans biofilm. This in vitro study demonstrated that violet-blue light has the capacity to inhibit S. mutans biofilm formation. Potential clinical applications of light therapy in the future remain bright in preventing the development and progression of dental caries.

Detection of AA-type amyloid protein in labial salivary glands.

PubMed

Sacsaquispe, Sonia-Julia; Antúnez-de Mayolo, Eleazar-Antonio; Vicetti, Rodolfo; Delgado, Wilson-Alejandro

2011-03-01

Among the diverse forms of amyloidosis, secondary type is the most frequent one. Diagnosis of amyloid deposition is based on the identification of the fibrillary protein amyloid by means of Congo Red (CR) or crystal violet (CV) stains, but these techniques do not differentiate between the different types of amyloid fibrils. The aim of this study was to identify by immunofluorescence (IF) AA amyloid a pathological fibrillar low-molecular-weight protein formed by cleavage of serum amyloid A (SAA) protein in labial salivary gland (LSG) biopsies from patients with secondary amyloidosis. 98 LSG were studied, 65 were from patients with secondary amyloidosis and 33 from subjects with chronic inflammatory diseases without evidence of this anomaly. All sections were stained with hematoxylin and eosin (H &E), CV, CR and IF using anti-AA antibodies. Positive and negative controls were used for all techniques. CV and CR demonstrated that the amyloid substance was found mainly distributed periductally (93.8%), followed by periacinar and perivascular locations (p <0.001); however, the IF demonstrated that amyloid AA substance predominates in the periacinar area (73.8%), followed by periductal and perivascular locations (p <0.001). IF has a sensitivity of 83%, 100% of specificity, 100% of predictive positive value and 75% of predictive negative value. The results of this study confirm the efficacy of the LSG biopsy as a highly reliable method for diagnosis of secondary amyloidosis.

Osteopontin splice variants expression is involved on docetaxel resistance in PC3 prostate cancer cells.

PubMed

Nakamura, K D M; Tilli, T M; Wanderley, J L; Palumbo, A; Mattos, R M; Ferreira, A C; Klumb, C E; Nasciutti, L E; Gimba, E R

2016-02-01

Osteopontin (OPN) is a phosphoprotein that activates several aspects of tumor progression. Alternative splicing of the OPN primary transcript generates three splicing isoforms, OPNa, OPNb and OPNc. In this report, we investigated some cellular mechanisms by which OPN splice variants could mediate PC3 prostate cancer (PCa) cell survival and growth in response to docetaxel (DXT)-induced cell death. Cell survival before and after DXT treatment was analyzed by phase-contrast microscopy and crystal-violet staining assays. Quantitative real-time PCR and immunocytochemical staining assays were used to evaluate the putative involvement of epithelial-mesenchymal transition (EMT) and OPN isoforms on mediating PC3 cell survival. Upon DXT treatment, PC3 cells overexpressing OPNb or OPNc isoforms showed higher cell densities, compared to cells overexpressing OPNa and controls. Notably, cells overexpressing OPNb or OPNc isoforms showed a downregulated pattern of EMT epithelial cell markers, while mesenchymal markers were mostly upregulated in these experimental conditions. We concluded that OPNc or OPNb overexpression in PC3 cells can mediate resistance and cell survival features in response to DXT-induced cell death. Our data also provide evidence the EMT program could be one of the molecular mechanisms mediating survival in OPNb- or OPNc-overexpressing cells in response to DXT treatment. These data could further contribute to a better understanding of the mechanisms by which PCa cells acquire resistance to DXT treatment.

Possible cause for altered spatial cognition of prepubescent rats exposed to chronic radiofrequency electromagnetic radiation.

PubMed

Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Karun, Kalesh M; Nayak, Satheesha B; Bhat, P Gopalakrishna

2015-10-01

The effects of chronic and repeated radiofrequency electromagnetic radiation (RFEMR) exposure on spatial cognition and hippocampal architecture were investigated in prepubescent rats. Four weeks old male Wistar rats were exposed to RF-EMR (900 MHz; SAR-1.15 W/kg with peak power density of 146.60 μW/cm(2)) for 1 h/day, for 28 days. Followed by this, spatial cognition was evaluated by Morris water maze test. To evaluate the hippocampal morphology; H&E staining, cresyl violet staining, and Golgi-Cox staining were performed on hippocampal sections. CA3 pyramidal neuron morphology and surviving neuron count (in CA3 region) were studied using H&E and cresyl violet stained sections. Dendritic arborization pattern of CA3 pyramidal neuron was investigated by concentric circle method. Progressive learning abilities were found to be decreased in RF-EMR exposed rats. Memory retention test performed 24 h after the last training revealed minor spatial memory deficit in RF-EMR exposed group. However, RF-EMR exposed rats exhibited poor spatial memory retention when tested 48 h after the final trial. Hirano bodies and Granulovacuolar bodies were absent in the CA3 pyramidal neurons of different groups studied. Nevertheless, RF-EMR exposure affected the viable cell count in dorsal hippocampal CA3 region. RF-EMR exposure influenced dendritic arborization pattern of both apical and basal dendritic trees in RF-EMR exposed rats. Structural changes found in the hippocampus of RF-EMR exposed rats could be one of the possible reasons for altered cognition.

Spectrally-isolated violet to blue wavelength generation by cascaded degenerate four-wave mixing in a photonic crystal fiber.

PubMed

Yuan, Jinhui; Kang, Zhe; Li, Feng; Zhang, Xianting; Zhou, Guiyao; Sang, Xinzhu; Wu, Qiang; Yan, Binbin; Zhou, Xian; Wang, Liang; Zhong, Kangping; Wang, Kuiru; Yu, Chongxiu; Tam, Hwa Yaw; Wai, P K A

2016-06-01

Generation of spectrally-isolated wavelengths in the violet to blue region based on cascaded degenerate four-wave mixing (FWM) is experimentally demonstrated for the first time in a tailor-made photonic crystal fiber, which has two adjacent zero dispersion wavelengths (ZDWs) at 696 and 852 nm in the fundamental mode. The influences of the wavelength λ_p and the input average power P_av of the femtosecond pump pulses on the phase-matched frequency conversion process are studied. When femtosecond pump pulses at λ_p of 880, 870, and 860 nm and P_av of 500 mW are coupled into the normal dispersion region close to the second ZDW, the first anti-Stokes waves generated near the first ZDW act as a secondary pump for the next FWM process. The conversion efficiency η_as2 of the second anti-Stokes waves, which are generated at the violet to blue wavelengths of 430, 456, and 472 nm, are 4.8, 6.48, and 9.66%, for λ_p equalling 880, 870, and 860 nm, respectively.

Anionic Photopolymerization of Methyl-2-Cyanoacrylate and Simultaneous Color Formation

DTIC Science & Technology

2000-11-15

Anionic polymerization of methyl 2-cyanoacrylate initiated by photoinduced heterolysis of crystal violet leuconitrile (CVCN) and of malachite green leucohydroxide (MGOH) is demonstrated. Polymerization is accompanied by color formation.

A new species of Daedalea (Basidiomycota) and a synopsis of core species in Daedalea sensu stricto

Treesearch

Daniel L. Lindner; Leif Ryvarden; Timothy J. Baroni

2011-01-01

Daedalea neotropica, a species with striking violet stains on the pileus and pore surface, is described from material collected in the Maya Mountains of Belize. A synopsis of Daedalea sensu stricto is provided based on morphological and DNA sequence data. Analyses indicate that at least four species should be included in ...

Unpredictable adsorption and visible light induced decolorization of nano rutile for the treatment of crystal violet

NASA Astrophysics Data System (ADS)

Dong, Yanling; Liu, Yang; Lu, Dingze; Zheng, Feng; Fang, Pengfei; Zhang, Haining

2017-04-01

Photocatalysts containing different ratios of anatase and rutile are prepared via heat treatment of Degussa P-25 titania. X-ray diffraction (XRD), Bruuauer-Emmett-Teller (BET), ultraviolet-visible light diffuse reflectance spectra (DRS), Raman spectra (Raman), positron annihilation lifetime spectra (PAL) and temperature-programmed desorption (TPD) are applied to investigate the phase composition of the synthesized catalysts. Using crystal violet (CV) as the target pollutant, the unexpected visible light decolorization of rutile is observed. Despite the decreased specific surface area, the as-synthesized rutile samples exhibit much higher adsorption capability of CV than P-25 does, which in turn leads to improved photoreaction efficiency. Since the rutile samples can't absorb the visible light, the degradation under visible light irradiation is attributed to self-sensitization of CV on the surface of rutile.

Accurate counting of neurons in frozen sections: some necessary precautions.

PubMed Central

Cooper, J D; Payne, J N; Horobin, R W

1988-01-01

In 30 microns frozen sections of rat midbrain the retrograde axonal transport of diamidino yellow, a fluorescent tracer, was used to demonstrate a population of neurons in the substantia nigra. However, when visualisation was carried out using the routine Nissl method a significant proportion of neurons failed to stain. As the presence of the retrograde tracer did not affect Nissl staining of such cells, such incomplete staining, with consequent underestimation of neuronal populations, is probably a common error in similar material. Further investigation revealed that the proportion of such unstained neurons was greater when the staining time was short, when stain concentration was low, or when section thickness was increased. Some stains were worse in this respect than others. Cresyl fast violet resulted in the highest proportion of unstained neurons, thionin resulted in the lowest proportion. It was concluded that the rate of diffusion of the stain into the section was the main factor limiting the staining of neurons present. Staining with pure thionin at 0.1% concentration for at least 3 minutes and with sections no thicker than 30 microns is one regime which would avoid this problem. Images Fig. 1 PMID:2461923

Multicolor photonic crystal laser array

DOEpatents

Wright, Jeremy B; Brener, Igal; Subramania, Ganapathi S; Wang, George T; Li, Qiming

2015-04-28

A multicolor photonic crystal laser array comprises pixels of monolithically grown gain sections each with a different emission center wavelength. As an example, two-dimensional surface-emitting photonic crystal lasers comprising broad gain-bandwidth III-nitride multiple quantum well axial heterostructures were fabricated using a novel top-down nanowire fabrication method. Single-mode lasing was obtained in the blue-violet spectral region with 60 nm of tuning (or 16% of the nominal center wavelength) that was determined purely by the photonic crystal geometry. This approach can be extended to cover the entire visible spectrum.

A robust, efficient and flexible method for staining myelinated axons in blocks of brain tissue.

PubMed

Wahlsten, Douglas; Colbourne, Frederick; Pleus, Richard

2003-03-15

Previous studies have demonstrated the utility of the gold chloride method for en bloc staining of a bisected brain in mice and rats. The present study explores several variations in the method, assesses its reliability, and extends the limits of its application. We conclude that the method is very efficient, highly robust, sufficiently accurate for most purposes, and adaptable to many morphometric measures. We obtained acceptable staining of commissures in every brain, despite a wide variety of fixation methods. One-half could be stained 24 h after the brain was extracted and the other half could be stained months later. When staining failed because of an exhausted solution, the brain could be stained successfully in fresh solution. Relatively small changes were found in the sizes of commissures several weeks after initial fixation or staining. A half brain stained to reveal the mid-sagittal section could then be sectioned coronally and stained again in either gold chloride for myelin or cresyl violet for Nissl substance. Uncertainty, arising from pixelation of digitized images was far less than errors arising from human judgments about the histological limits of major commissures. Useful data for morphometric analysis were obtained by scanning the surface of a gold chloride stained block of brain with an inexpensive flatbed scanner.

Formation of Biofilms by Foodborne Pathogens and Development of Laboratory In Vitro Model for the Study of Campylobacter Genus Bacteria Based on These Biofilms.

PubMed

Efimochkina, N R; Bykova, I B; Markova, Yu M; Korotkevich, Yu V; Stetsenko, V V; Minaeva, L P; Sheveleva, S A

2017-02-01

We analyzed the formation of biofilms by 7 strains of Campylobacter genus bacteria and 18 strains of Enterobacteriaceae genus bacteria that were isolated from plant and animal raw materials, from finished products, and swabs from the equipment of the food industry. Biofilm formation on glass plates, slides and coverslips, microtubes made of polymeric materials and Petri dishes, and polystyrene plates of different profiles were analyzed. When studying the process of films formation, different effects on bacterial populations were simulated, including variation of growth factor composition of culture media, technique of creating of anaerobiosis, and biocide treatment (active chlorine solutions in a concentration of 100 mg/dm 3 ). The formation of biofilms by the studied cultures was assessed by the formation of extracellular matrix stained with aniline dyes on glass and polystyrene surfaces after incubation; 0.1% crystal violet solution was used as the dye. The presence and density of biomatrix were assessed by staining intensity of the surfaces of contact with broth cultures or by optical density of the stained inoculum on a spectrophotometer. Biofilms were formed by 57% Campylobacter strains and 44% Enterobacteriaceae strains. The intensity of the film formation depended on culturing conditions and protocols, species and genus of studied isolates, and largely on adhesion properties of abiotic surfaces. In 30% of Enterobacteriaceae strains, the biofilm formation capacity tended to increase under the influence of chlorine-containing biocide solutions. Thus, we developed and tested under laboratory conditions a plate version of in vitro chromogenic model for evaluation of biofilm formation capacity of C. jejuni strains and studied stress responses to negative environmental factors.

Tuned apatitic materials: Synthesis, characterization and potential antimicrobial applications

NASA Astrophysics Data System (ADS)

Fierascu, Irina; Fierascu, Radu Claudiu; Somoghi, Raluca; Ion, Rodica Mariana; Moanta, Adriana; Avramescu, Sorin Marius; Damian, Celina Maria; Ditu, Lia Mara

2018-04-01

Inorganic antimicrobial materials can be viable for multiple applications (related to its use for new buildings with special requirements related to microbiological loading, such as hospital buildings and for consolidation of cultural heritage constructions); also the use of substituted hydroxyapatites for protection of stone artefacts against environmental factors (acidic rain) and biodeterioration it's an option to no longer use of toxic substances. This paper presents methods of synthesis and characterization of the material from the point of view of the obtained structures and final applications. The materials were characterized in terms of composition and morphology (using X-ray Diffraction, X-ray Fluorescence, Inductively coupled plasma-atomic emission spectrometry, Fourier Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy, Surface area and pore size determination). Antimicrobial activity was tested against filamentous fungi strains and pathogenic bacteria strains, using both spot on lawn qualitative method (on agar medium) and serial microdilution quantitative method (in broth medium). Further, it was evaluated the anti-biofilm activity of the tested samples toward the most important microbial strains implicated in biofilm development, using crystal violet stained biofilms microtiter assay, followed by spectrophotometric quantitative evaluation.

Screening of biofilm formation by beneficial vaginal lactobacilli and influence of culture media components.

PubMed

Terraf, M C Leccese; Juárez Tomás, M S; Nader-Macías, M E F; Silva, C

2012-12-01

To assess the ability of vaginal lactobacilli to form biofilm under different culture conditions and to determine the relationship between their growth and the capability of biofilm formation by selected strains. Fifteen Lactobacillus strains from human vagina were tested for biofilm formation by crystal violet staining. Only Lactobacillus rhamnosus Centro de Referencia para Lactobacilos Culture Collection (CRL) 1332, Lact. reuteri CRL 1324 and Lact. delbrueckii CRL 1510 were able to grow and form biofilm in culture media without Tween 80. However, Lact. gasseri CRL 1263 (a non-biofilm-forming strain) did not grow in these media. Scanning electron microscopy showed that Lact. rhamnosus CRL 1332 and Lact. reuteri CRL 1324 formed a highly structured biofilm, but only Lact. reuteri CRL 1324 showed a high amount of extracellular material in medium without Tween. Biofilm formation was significantly influenced by the strain, culture medium, inoculum concentration, microbial growth and chemical nature of the support used for the assay. The results allow the selection of biofilm-forming vaginal Lactobacillus strains and the conditions and factors that affect this phenomenon. © 2012 The Society for Applied Microbiology.

Reliability of Haemophilus influenzae biofilm measurement via static method, and determinants of in vitro biofilm production.

PubMed

Obaid, Najla A; Tristram, Stephen; Narkowicz, Christian K; Jacobson, Glenn A

2016-12-01

Information is lacking regarding the precision of microtitre plate (MTP) assays used to measure biofilm. This study investigated the precision of an MTP assay to measure biofilm production by nontypeable Haemophilus influenzae (NTHi) and the effects of frozen storage and inoculation technique on biofilm production. The density of bacterial final growth was determined by absorbance after 18-20 h incubation, and biofilm production was then measured by absorbance after crystal violet staining. Biofilm formation was categorised as high and low for each strain. For the high biofilm producing strains of NTHi, interday reproducibility of NTHi biofilm formation measured using the MTP assay was excellent and met the acceptance criteria, but higher variability was observed in low biofilm producers. Method of inoculum preparation was a determinant of biofilm formation with inoculum prepared directly from solid media showing increased biofilm production for at least one of the high producing strains. In general, storage of NTHi cultures at -80 °C for up to 48 weeks did not have any major effect on their ability to produce biofilm.

Planktonic growth and biofilm formation profiles in Candida haemulonii species complex.

PubMed

Ramos, Lívia S; Oliveira, Simone S C; Souto, Xênia M; Branquinha, Marta H; Santos, André L S

2017-10-01

Candida haemulonii species complex have emerged as multidrug-resistant yeasts able to cause fungemia worldwide. However, very little is known regarding their physiology and virulence factors. In this context, planktonic growth and biofilm formation of Brazilian clinical isolates of Candida haemulonii (n = 5), Candida duobushaemulonii (n = 4), and Candida haemulonii var. vulnera (n = 3) were reported. Overall, the fungal planktonic growth curves in Sabouraud dextrose broth reached the exponential phase in 48 h at 37°C. All the clinical isolates formed biofilm on polystyrene in a time-dependent event, as judged by the parameters evaluated: biomass (crystal violet staining), metabolic activity (XTT reduction), and extracellular matrix (safranin incorporation). No statistically significant differences were observed when the average measurements among the three Candida species were compared regarding both planktonic and biofilm lifestyles; however, typical isolate-specific differences were clearly noticed in fungal growth kinetics. © The Author 2017. 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.

Quantification of alginate by aggregation induced by calcium ions and fluorescent polycations.

PubMed

Zheng, Hewen; Korendovych, Ivan V; Luk, Yan-Yeung

2016-01-01

For quantification of polysaccharides, including heparins and alginates, the commonly used carbazole assay involves hydrolysis of the polysaccharide to form a mixture of UV-active dye conjugate products. Here, we describe two efficient detection and quantification methods that make use of the negative charges of the alginate polymer and do not involve degradation of the targeted polysaccharide. The first method utilizes calcium ions to induce formation of hydrogel-like aggregates with alginate polymer; the aggregates can be quantified readily by staining with a crystal violet dye. This method does not require purification of alginate from the culture medium and can measure the large amount of alginate that is produced by a mucoid Pseudomonas aeruginosa culture. The second method employs polycations tethering a fluorescent dye to form suspension aggregates with the alginate polyanion. Encasing the fluorescent dye in the aggregates provides an increased scattering intensity with a sensitivity comparable to that of the conventional carbazole assay. Both approaches provide efficient methods for monitoring alginate production by mucoid P. aeruginosa. Copyright © 2015 Elsevier Inc. All rights reserved.

Composition, Cytotoxic and Antimicrobial Activities of Satureja intermedia C.A.Mey Essential Oil.

PubMed

Sharifi-Rad, Javad; Sharifi-Rad, Mehdi; Hoseini-Alfatemi, Seyedeh Mahsan; Iriti, Marcello; Sharifi-Rad, Majid; Sharifi-Rad, Marzieh

2015-08-03

In this study, the essential oil (EO) constituents from the aerial parts of Satureja intermedia C.A.Mey were detected by GC and GC/MS. The antimicrobial activity of EO on oral pathogens and its cytotoxicity to human cancer cells were determined by the microbroth dilution method and the crystal violet staining method, respectively. Thirty-nine compounds were identified and the main EO constituents were γ-terpinene (37.1%), thymol (30.2%), p-cymene (16.2%), limonene (3.9%), α-terpinene (3.3%), myrcene (2.5%), germacrene B (1.4%), elemicine (1.1%) and carvacrol (0.5%). The S. intermedia EO showed a concentration-dependent decrease in viability of Hep-G2 (hepatocellular carcinoma) and MCF-7 (breast adenocarcinoma) human cancer cell lines (p < 0.05). Antimicrobial screening of S. intermedia EO demonstrated slight antibacterial and antifungal activities against Streptococcus mutants, S. salivarius, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. glabrata. Further preclinical studies are needed to assess the efficacy and safety of S. intermedia EO as a new promising anticancer agent.

Composition, Cytotoxic and Antimicrobial Activities of Satureja intermedia C.A.Mey Essential Oil

PubMed Central

Sharifi-Rad, Javad; Sharifi-Rad, Mehdi; Hoseini-Alfatemi, Seyedeh Mahsan; Iriti, Marcello; Sharifi-Rad, Majid; Sharifi-Rad, Marzieh

2015-01-01

In this study, the essential oil (EO) constituents from the aerial parts of Satureja intermedia C.A.Mey were detected by GC and GC/MS. The antimicrobial activity of EO on oral pathogens and its cytotoxicity to human cancer cells were determined by the microbroth dilution method and the crystal violet staining method, respectively. Thirty-nine compounds were identified and the main EO constituents were γ-terpinene (37.1%), thymol (30.2%), p-cymene (16.2%), limonene (3.9%), α-terpinene (3.3%), myrcene (2.5%), germacrene B (1.4%), elemicine (1.1%) and carvacrol (0.5%). The S. intermedia EO showed a concentration-dependent decrease in viability of Hep-G2 (hepatocellular carcinoma) and MCF-7 (breast adenocarcinoma) human cancer cell lines (p < 0.05). Antimicrobial screening of S. intermedia EO demonstrated slight antibacterial and antifungal activities against Streptococcus mutants, S. salivarius, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. glabrata. Further preclinical studies are needed to assess the efficacy and safety of S. intermedia EO as a new promising anticancer agent. PMID:26247936

Further investigation of relationships between membrane fluidity and ethanol tolerance in Saccharomyces cerevisiae.

PubMed

Ishmayana, Safri; Kennedy, Ursula J; Learmonth, Robert P

2017-11-27

Membrane lipid unsaturation index and membrane fluidity have been related to yeast ethanol stress tolerance in published studies, however findings have been inconsistent. In this study, viability reduction on exposure to 18% (v/v) ethanol was compared to membrane fluidity determined by laurdan generalized polarization. Furthermore, in the determination of viability reduction, we examined the effectiveness of two methods, namely total plate count and methylene violet staining. We found a strong negative correlation between ethanol tolerance and membrane fluidity, indicated by negative Pearson correlation coefficients of - 0.79, - 0.65 and - 0.69 for Saccharomyces cerevisiae strains A12, PDM and K7, respectively. We found that lower membrane fluidity leads to higher ethanol tolerance, as indicated by decreased viability reduction and higher laurdan generalized polarization in respiratory phase compared to respiro-fermentative phase cells. Total plate count better differentiated ethanol tolerance of yeast cells in different growth phases, while methylene violet staining was better to differentiate ethanol tolerance of the different yeast strains at a particular culture phase. Hence, both viability assessment methods have their own advantages and limitations, which should be considered when comparing stress tolerance in different situations.

The limitations of Gram-stain microscopy of synovial fluid in concomitant septic and crystal arthritis.

PubMed

Stirling, Paul; Tahir, Mohammed; Atkinson, Henry Dushan

2017-03-29

Rapid diagnosis of septic arthritis from Gram-stain microscopy is limited by an inherent false-negative rate of 25-78%. The presence of concomitant crystal arthritis in 5% of cases represents a particular diagnostic challenge. This study aims to investigate the effects that a concomitant crystal arthropathy have on the ability of Gram-stain microscopy of synovial fluid to diagnose a septic arthritis. This is a 12-year retrospective cohort study. Inclusion criteria were a positive synovial fluid culture result with a positive clinical diagnosis of septic arthritis. Results were correlated with presence or absence of urate and calcium pyrophosphate crystals, and Gram-stain result. During this time our collection and analysis methods remained unchanged. All samples were collected in Lithium Heparin containers. Chi-squared test with a p value < 0.05 was considered significant. 602 synovial fluid samples were included. 162 cases of concomitant crystal arthritis were identified (27%). Of these, 16 (10%) had an initial negative Gram-stain. Of the 440 samples with no crystals detected, 18 (4%) had an initial negative Gram-stain microscopy result (p < 0.05). The incidence of concurrent septic and crystal arthritis may be higher than previously thought. Synovial fluid samples in concomitant septic and crystal arthritis are significantly less likely to have a positive Gram-stain at microscopy than in cases of an isolated septic arthritis. We would advise the clinician to maintain a high index of suspicion for septic arthritis in these patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Inclusion study of hourglass amethyst from Boudi (Morocco) by Raman microspectroscopy and microthermometric measurements

NASA Astrophysics Data System (ADS)

Dumańska-Słowik, Magdalena; Toboła, Tomasz; Jarmołowicz-Szulc, Katarzyna; Naglik, Beata; Dyląg, Joanna; Szczerba, Jacek

2017-12-01

Amethyst from Boudi with characteristic hourglass colour zoning hosts numerous pseudo-secondary fluid and mineral inclusions. Measured values of temperature homogenization (Th) for selected fluid inclusion assemblages (FIA) in colourless and violet regions of the crystal range from 154 to 330 °C. The higher temperatures values are characteristic for violet zones than colourless regions of the crystal. The brine content and concentration vary from 5.71 to 13.94 wt% NaCl eq. Raman spectra of selected fluid inclusions revealed they are mainly composed of H2O (3500-3000 cm- 1) and subordinately CO2 both gaseous and liquid (1386 cm- 1 and 1281 cm- 1). Mineral inclusions are mainly represented by hematite with marker bands at 1321, 413, 293 and 227 cm- 1, subordinately quartz. Amethyst crystallized from medium- to low-temperature silica fluids (191-445 °C, 64-131 MPa) containing some amounts of CO2 and Fe at hydrothermal stage of post magmatic activity in Boudi (Morocco). Its possible depth of formation was calculated to be ca. 2.8-5.7 km.

Selection and characterization of a DNA aptamer to crystal violet.

PubMed

Chen, Yang; Wang, Jine; Zhang, Yajie; Xu, Lijun; Gao, Tian; Wang, Bing; Pei, Renjun

2018-06-13

Aptamers are short single-stranded DNA or RNA, which can be selected in vitro by systematic evolution of ligands by exponential enrichment (SELEX). In order to develop novel light-up probes to substitute G-quadruplex (G4), we selected a DNA aptamer for crystal violet (CV), a triphenylmethane light-up dye, by a modified affinity chromatography-based SELEX. The ssDNA pool was first coupled on streptavidin-coated agarose beads through a biotin labeled complementary oligonucleotide, and then the aptamer sequences would be released from agarose beads by CV affinity. This method is simple, straightforward and effective. The aptamer sequence with a low micromolar dissociation constant (Kd) and good specificity was achieved after 11 rounds of selection. The light-up properties of the CV-aptamer were also investigated, and the CV showed dramatic fluorescence enhancement. The CV-aptamer pair could be further used as a novel light-up fluorescent probe to design biosensors.

Detection of Prohibited Fish Drugs Using Silver Nanowires as Substrate for Surface-Enhanced Raman Scattering

PubMed Central

Song, Jia; Huang, Yiqun; Fan, Yuxia; Zhao, Zhihui; Yu, Wansong; Rasco, Barbara A.; Lai, Keqiang

2016-01-01

Surface-enhanced Raman scattering or surface-enhanced Raman spectroscopy (SERS) is a promising detection technology, and has captured increasing attention. Silver nanowires were synthesized using a rapid polyol method and optimized through adjustment of the molar ratio of poly(vinyl pyrrolidone) and silver nitrate in a glycerol system. Ultraviolet-visible spectrometry, X-ray diffraction, and transmission electron microscopy were used to characterize the silver nanowires. The optimal silver nanowires were used as a SERS substrate to detect prohibited fish drugs, including malachite green, crystal violet, furazolidone, and chloramphenicol. The SERS spectra of crystal violet could be clearly identified at concentrations as low as 0.01 ng/mL. The minimum detectable concentration for malachite green was 0.05 ng/mL, and for both furazolidone and chloramphenicol were 0.1 μg/mL. The results showed that the as-prepared Ag nanowires SERS substrate exhibits high sensitivity and activity. PMID:28335303

Insight into biosorption equilibrium, kinetics and thermodynamics of crystal violet onto Ananas comosus (pineapple) leaf powder

NASA Astrophysics Data System (ADS)

Chakraborty, Sagnik; Chowdhury, Shamik; Saha, Papita Das

2012-06-01

Biosorption performance of pineapple leaf powder (PLP) for removal of crystal violet (CV) from its aqueous solutions was investigated. To this end, the influence of operational parameters such as pH, biosorbent dose, initial dye concentration and temperature were studied employing a batch experimental setup. The biosorption process followed the Langmuir isotherm model with high correlation coefficients ( R 2 > 0.99) at different temperatures. The maximum monolayer biosorption capacity was found to be 78.22 mg g-1 at 293 K. The kinetic data conformed to the pseudo-second-order kinetic model. The activation energy of the system was calculated as 58.96 kJ mol- 1 , indicating chemisorption nature of the ongoing biosorption process. A thermodynamic study showed spontaneous and exothermic nature of the biosorption process. Owing to its low cost and high dye uptake capacity, PLP has potential for application as biosorbent for removal of CV from aqueous solutions.

Effect of electrical energy on the efficacy of biofilm treatment using the bioelectric effect

PubMed Central

Kim, Young Wook; Subramanian, Sowmya; Gerasopoulos, Konstantinos; Ben-Yoav, Hadar; Wu, Hsuan-Chen; Quan, David; Carter, Karen; Meyer, Mariana T; Bentley, William E; Ghodssi, Reza

2015-01-01

Background/Objectives: The use of electric fields in combination with small doses of antibiotics for enhanced treatment of biofilms is termed the ‘bioelectric effect’ (BE). Different mechanisms of action for the AC and DC fields have been reported in the literature over the last two decades. In this work, we conduct the first study on the correlation between the electrical energy and the treatment efficacy of the bioelectric effect on Escherichia coli K-12 W3110 biofilms. Methods: A thorough study was performed through the application of alternating (AC), direct (DC) and superimposed (SP) potentials of different amplitudes on mature E. coli biofilms. The electric fields were applied in combination with the antibiotic gentamicin (10 μg/ml) over a course of 24 h, after the biofilms had matured for 24 h. The biofilms were analysed using the crystal violet assay, the colony-forming unit method and fluorescence microscopy. Results: Results show that there is no statistical difference in treatment efficacy between the DC-, AC- and SP-based BE treatment of equivalent energies (analysis of variance (ANOVA) P>0.05) for voltages <1 V. We also demonstrate that the efficacy of the BE treatment as measured by the crystal violet staining method and colony-forming unit assay is proportional to the electrical energy applied (ANOVA P<0.05). We further verify that the treatment efficacy varies linearly with the energy of the BE treatment (r2 =0.984). Our results thus suggest that the energy of the electrical signal is the primary factor in determining the efficacy of the BE treatment, at potentials less than the media electrolysis voltage. Conclusions: Our results demonstrate that the energy of the electrical signal, and not the type of electrical signal (AC or DC or SP), is the key to determine the efficacy of the BE treatment. We anticipate that this observation will pave the way for further understanding of the mechanism of action of the BE treatment method and may open new doors to the use of electric fields in the treatment of bacterial biofilms. PMID:28721233

Inhibition of Serratia marcescens Smj-11 biofilm formation by Alcaligenes faecalis STN17 crude extract

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lutfi, Zainal; Ahmad, Asmat; Usup, Gires

Serratia marcescens biofilms are formed when they are bound to surfaces in aqueous environments. S. marcescens utilizes N-acylhomoserine lactone (AHL) as its quorum sensing signal molecule. The accumulation of AHL indicates the bacteria to produce matrices to form biofilms. Prodigiosin (2-methyl-3-pentyl-6-methoxyprodigiosin), which causes red pigmentation in the colonies, are also produced when the AHL reaches a certain threshold. The Alcaligenes faecalis STN17 crude extract is believed to inhibit quorum sensing in the S. marcescens Smj-11 and, thus, impedes its biofilm formation ability. A. faecalis STN17 was grown in marine broth, and ethyl acetate extraction was carried out. The crude compoundmore » of A. faecalis STN17 was diluted at high concentration (0.2-6.4 mg/mL) and was taken to confirm anti-biofilm activity through the crystal violet method in 96-wells plate. Then, the crude extract underwent purification using simple solvents partitioning test to discern the respective compounds that had the anti-biofilm activity under the crystal violet method. The crystal violet test showed that the crude did have anti-biofilm activity on S. marcescens Smj-11, but did not kill the cells. This finding signifies that the suppression of biofilm formation in S. marcescens by A. faecalis STN17 has a strong correlation. The partitioning test showed that A. faecalis STN17 crude extract has several compounds and only the compound(s) in chloroform showed activities. In conclusion, the crude extract of A. faecalis STN17 has the ability to inhibit S. marcescens Smj-11 biofilm formation.« less

Polypyrrole-magnetite dispersive micro-solid-phase extraction combined with ultraviolet-visible spectrophotometry for the determination of rhodamine 6G and crystal violet in textile wastewater.

PubMed

Kamaruddin, Amirah Farhan; Sanagi, Mohd Marsin; Wan Ibrahim, Wan Aini; Md Shukri, Dyia S; Abdul Keyon, Aemi S

2017-11-01

Polypyrrole-magnetite dispersive micro-solid-phase extraction method combined with ultraviolet-visible spectrophotometry was developed for the determination of selected cationic dyes in textile wastewater. Polypyrrole-magnetite was used as adsorbent due to its thermal stability, magnetic properties, and ability to adsorb Rhodamine 6G and crystal violet. Dispersive micro-solid-phase extraction parameters were optimized, including sample pH, adsorbent amount, extraction time, and desorption solvent. The optimum polypyrrole-magnetite dispersive micro-solid phase-extraction conditions were sample pH 8, 60 mg polypyrrole-magnetite adsorbent, 5 min of extraction time, and acetonitrile as the desorption solvent. Under the optimized conditions, the polypyrrole-magnetite dispersive micro-solid-phase extraction with ultraviolet-visible method showed good linearity in the range of 0.05-7 mg/L (R 2  > 0.9980). The method also showed a good limit of detection for the dyes (0.05 mg/L) and good analyte recoveries (97.4-111.3%) with relative standard deviations < 10%. The method was successfully applied to the analysis of dyes in textile wastewater samples where the concentration found was 1.03 mg (RSD ±7.9%) and 1.13 mg/L (RSD ± 4.6%) for Rhodamine 6G and crystal violet, respectively. It can be concluded that this method can be adopted for the rapid extraction and determination of dyes at trace concentration levels. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inhibition of Serratia marcescens Smj-11 biofilm formation by Alcaligenes faecalis STN17 crude extract

NASA Astrophysics Data System (ADS)

Lutfi, Zainal; Usup, Gires; Ahmad, Asmat

2014-09-01

Serratia marcescens biofilms are formed when they are bound to surfaces in aqueous environments. S. marcescens utilizes N-acylhomoserine lactone (AHL) as its quorum sensing signal molecule. The accumulation of AHL indicates the bacteria to produce matrices to form biofilms. Prodigiosin (2-methyl-3-pentyl-6-methoxyprodigiosin), which causes red pigmentation in the colonies, are also produced when the AHL reaches a certain threshold. The Alcaligenes faecalis STN17 crude extract is believed to inhibit quorum sensing in the S. marcescens Smj-11 and, thus, impedes its biofilm formation ability. A. faecalis STN17 was grown in marine broth, and ethyl acetate extraction was carried out. The crude compound of A. faecalis STN17 was diluted at high concentration (0.2-6.4 mg/mL) and was taken to confirm anti-biofilm activity through the crystal violet method in 96-wells plate. Then, the crude extract underwent purification using simple solvents partitioning test to discern the respective compounds that had the anti-biofilm activity under the crystal violet method. The crystal violet test showed that the crude did have anti-biofilm activity on S. marcescens Smj-11, but did not kill the cells. This finding signifies that the suppression of biofilm formation in S. marcescens by A. faecalis STN17 has a strong correlation. The partitioning test showed that A. faecalis STN17 crude extract has several compounds and only the compound(s) in chloroform showed activities. In conclusion, the crude extract of A. faecalis STN17 has the ability to inhibit S. marcescens Smj-11 biofilm formation.

Novel compounds TAD-1822-7-F2 and F5 inhibited HeLa cells growth through the JAK/Stat signaling pathway.

PubMed

Yang, Tianfeng; Shi, Xianpeng; Kang, Yuan; Zhu, Man; Fan, Mengying; Zhang, Dongdong; Zhang, Yanmin

2018-07-01

Cervical carcinoma remains the second most common malignancy with a high mortality rate among women worldwide. TAD-1822-7-F2 (F2) and TAD-1822-7-F5 (F5) are novel compounds synthesized on the chemical structure of taspine derivatives, and show an effective suppression for HeLa cells. Our study aims to confirm the potential targets of F2 and F5, and investigate the underlying mechanism of the inhibitory effect on HeLa cells. In this study, Real Time Cell Analysis and crystal violet staining assay were conducted to investigate the effect of F2 and F5 on HeLa cells proliferation. And the analytical methods of surface plasmon resonance and quartz crystal microbalance were established and employed to study the interaction between F2 and F5 and potential target protein JAK2, suggesting that both compounds have strong interaction with the JAK2 protein. Western blot analysis, immunofluorescence staining study and PCR was conducted to investigate the molecules of JAK/Stat signaling pathway. Interestingly, F2 and F5 showed diverse regulation for signaling molecules because of their different chemical structure. F2 increased the expression of JAK2 and downregulated the level of P-JAK1 and P-JAK2, and decreased P-Stat3 (Ser727). While F5 could increase the expression of JAK2 and naturally decrease the phosphorylation of JAK1 and Tyk2, and decreased the expression of P-Stat6. Moreover, F2 and F5 showed the same downregulation on the P-Stat3 (Tyr705). Therefore, F2 and F5 could target the JAK2 protein and prevent the phosphorylation of JAKs to suppress the phosphorylation of the downstream effector Stats, which suggested that F2 and F5 have great potential to be the inhibitors of the JAK/Stat signaling pathway. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

A Simple Tubular Reactor Experiment.

ERIC Educational Resources Information Center

Hudgins, Robert R.; Cayrol, Bertrand

1981-01-01

Using the hydrolysis of crystal violet dye by sodium hydroxide as an example, the theory, apparatus, and procedure for a laboratory demonstration of tubular reactor behavior are described. The reaction presented can occur at room temperature and features a color change to reinforce measured results. (WB)

Growth of GaN single crystals by a Ca- and Ba-added Na flux method

NASA Astrophysics Data System (ADS)

Ukegawa, H.; Konishi, Y.; Fujimori, T.; Miyoshi, N.; Imade, M.; Yoshimura, M.; Kitaoka, Y.; Sasaki, T.; Mori, Y.

2011-02-01

GaN substrates are desirable for fabricating ultra-violet LEDs and LDs, and high-power and high-frequency transistors. High-quality GaN single crystals can be obtained by using Na flux method, but the growth habit of bulk crystals must be controlled. In this study, we investigated the effects of additives (Ca, Ba) on the growth habit and impurity concentration in the crystals. The aspect ratio (c/a) of the crystals was increased by increasing the amount of additives, showing that the growth habit could be changed from the pyramidal shape to the prism shape. Ba concentration was below the detection limit (1x1015 atoms/cm3).

High-performance envelopes for wood

Treesearch

Roger M. Rowell

2007-01-01

Wood can be coated with a clear finish, stained or painted to provide protection from water and ultra violet energy. In this case the coating and wood are two different phases that coexist. Another approach is to provide protection by “coating” in the surface not on the surface. Such an approach is referred to as an envelop rather than a coating. This can be done in...

Behavioral Consequences of Kainic Acid Lesions and Fetal Transplants of the Striatum

DTIC Science & Technology

1984-06-12

Selected sections were also stained with cresyl violet in order to facilitate the visualization of neuronal cytology and morphology. All sections...tendency to mutism and depression with frequent suicidal ideation (Bruyn, 1973). The Westphal variant of HD, also called the rigid-hypokinetic...1978). In situ injections of kainic acid: A new method for selectively lesioning neuronal cell bodies while sparing axons of passage. Journal of

Characterization of Staphylococcus epidermidis strains isolated from industrial cleanrooms under regular routine disinfection.

PubMed

Ribič, U; Klančnik, A; Jeršek, B

2017-05-01

The purpose of this study was the genotypic and phenotypic characterization of 57 strains of Staphylococcus epidermidis isolated from cleanroom environments, based on their biofilm formation and antimicrobial resistance profiles. Biofilm formation was investigated using real-time PCR (icaA, aap, bhp genes), the Congo red agar method and the crystal violet assay. The majority of the strains (59·7%; 34/57) did not form biofilms according to the crystal violet assay, although the biofilm-associated genes were present in 94·7% (54/57) of the strains. Of the biofilm formers (40·4%; 23/57), 39·1% (9/23) have been identified as strong biofilm formers (>4× crystal violet absorbance cut-off). Resistance to a commercial disinfectant and its quaternary ammonium active component, didecyl-dimethyl-ammonium chloride (DDAC), was determined according to minimum inhibitory concentrations (MICs) and the presence of the qac (quaternary ammonium compound) genes. More than 95% (55/57) of the Staph. epidermidis strains had the qacA/B and qacC genes, but not the other qac genes. The MICs for the disinfectant and DDAC varied among the Staph. epidermidis strains, although none were resistant. Although 59·6% of the Staph. epidermidis strains did not form biofilms and none were resistant to DDAC, more than 94% had the genetic basis for development of resistance to quaternary ammonium compounds, and among them at least 14·0% (8/57) might represent a high risk to cleanroom hygiene as strong biofim formers with qacA/B and qacC genes. To assure controlled cleanroom environments, bacterial strains isolated from cleanroom environments need to be characterized regularly using several investigative methods. © 2017 The Society for Applied Microbiology.

In situ Silver Spot Preparation and on-Plate Surface-Enhanced Raman Scattering Detection in Thin Layer Chromatography Separation

NASA Astrophysics Data System (ADS)

Herman, K.; Mircescu, N. E.; Szabo, L.; Leopold, L. F.; Chiş, V.; Leopold, N.

2013-05-01

An improved approach for surface-enhanced Raman scattering (SERS) detection of mixture constituents after thin layer chromatography (TLC) separation is presented. A SERS active silver substrate was prepared under open air conditions, directly on the thin silica film by photo-reduction of silver nitrate, allowing the detection of binary mixtures of cresyl violet, bixine, crystal violet, and Cu(II) complex of 4-(2-pyridylazo)resorcinol. The recorded SERS spectrum provides a unique spectral fingerprint for each molecule; therefore the use of analyte standards is avoided, thus rendering the presented procedure advantageous compared to the conventional detection methodology in TLC.

AROMATIC AMINES IN AND NEAR THE BUFFALO RIVER

EPA Science Inventory

Three sediment samples taken from the Buffalo River and two soil samples taken near its bank have been analyzed for 2-propanol-extractable, basic organic compounds by using GC/MS. Eleven aromatic amines related to the commercial production of malachite green and crystal violet we...

[Flotation spectrophotometric determination of copper on isochromatic dye ion pair with crystal violet and bromopnenol blue].

PubMed

Liu, B; Chen, C; Zuo, B

1999-02-01

Bromophenol blue (BPB) was produced and entered into the aqueous phase when NaOH solution of pH = 10 was added to Cu(biq)2BPB by trichloromethane and isoamyl alcohol (20:1) extractive. And then CV x BPB was floated by crystal violet (CV) with benzene solution. The flotation was dissolved in ethanol and the absorbance of the solution measured at 590 nm. The sensitivity was raised because of the two dyes assistant effect. The molar absorptivity was 1.45 x 10(5) L x mol(-1) x cm(-1). Copper in the sample was separated first by extracting the Cu(biq)2BPB complex with trichloromethane and isoamyl alcohol, thus achieving a high selectivity. Beer's law was obeyd in the range of 0-0. 4 mg/L with a relative standard deviation of 3.6%. For 4.8 x 10(-8) g/mL copper solution, the recoveries were 97.8%-101.7%.

Carbocation/Polyol Systems as Efficient Organic Catalysts for the Preparation of Cyclic Carbonates.

PubMed

Rulev, Yuri A; Gugkaeva, Zalina T; Lokutova, Anastasia V; Maleev, Victor I; Peregudov, Alexander S; Wu, Xiao; North, Michael; Belokon, Yuri N

2017-03-22

Carbocation/polyol systems are shown to be highly efficient catalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide at 50 °C and 5 MPa CO 2 pressure. The best activity was shown by the combination of crystal violet and 1,1'-bi-2-naphthol (BINOL), which could be recycled five times with no loss of activity. The presence of specific interactions between the amino groups of the carbocation and the hydroxyl protons was confirmed by NMR experiments. The Job plots for the crystal violet iodide/BINOL and brilliant green iodide/BINOL systems showed that the catalytic systems consist of one molecule of the carbocation and one molecule of BINOL. Mechanistic studies using a deuterated epoxide indicate that there was some loss of epoxide stereochemistry during the reaction, but predominant retention of stereochemistry is observed. On this basis, a catalytic cycle is proposed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kinetic Study of Adsorption Processes in Solution: An Undergraduate Physical Chemistry Experiment.

ERIC Educational Resources Information Center

Casado, Julio; And Others

1985-01-01

Background information, apparatus needed, procedures used, and results obtained are provided for a simple kinetic method for the monitoring of adsorption processes. The method, which involved adsorption of crystal violet onto activated carbon, is suitable for classroom and/or research purposes. (JN)

Enhanced biofilm formation in dual-species culture of Listeria monocytogenes and Ralstonia insidiosa

USDA-ARS?s Scientific Manuscript database

In the environment, many microorganisms coexist in communities as biofilms. The objective of this study was to investigate the interactions between Listeria monocytogenes and Ralstonia insidiosa in dual species biofilms. Biofilm development was measured using crystal violet in 96-well microtiter pla...

Antibacterial activity of food-grade chitosan against Vibrio parahaemolyticus biofilms.

PubMed

Xie, Ting; Liao, Zhenlin; Lei, Huan; Fang, Xiang; Wang, Jie; Zhong, Qingping

2017-09-01

Biofilm is a community composed of microbes and the extracellular polymeric substances. This special architecture poses a significant public health risk as it increases the fitness of bacteria in harsh conditions and renders bacterial resistance to antimicrobial agents and cleaning. In this study, we investigated the inhibition and eradication effects of chitosan on the biofilm of Vibrio parahaemolyticus, an important food-borne pathogen. The crystal violet staining, [2, 3-bis (2-methoxy-4-nitro-5- sulfophenyl)-2H-tetrazolium-5-carboxanilide] (XTT) reduction method, phenol-sulfuric acid method, fluorescence microscope and confocal laser scanning microscope (CLSM) observation were conducted. The results indicated that the minimum inhibitory concentration (MIC) of chitosan was 1.25 mg/mL. Sub-MIC of chitosan could significantly inhibit biofilm formation, reduce the metabolic activities and the secretion of extracellular polysaccharide (EPS). Moreover, chitosan at 4MIC could eradicate 85.06% mature biofilm of V. parahaemolyticus, and decrease 81.43% EPS in mature biofilm. These results were also confirmed by the visual images obtained from fluorescence microscopy and CLSM. This study elucidated that chitosan was not only effective to prevent biofilm formation, but also eradicate mature biofilms of V. parahaemolyticus. Copyright © 2017. Published by Elsevier Ltd.

Formation of biofilm by Listeria monocytogenes ATCC 19112 at different incubation temperatures and concentrations of sodium chloride

PubMed Central

Lee, H.Y.; Chai, L.C.; Pui, C.F.; Mustafa, S.; Cheah, Y.K.; Nishibuchi, M.; Radu, S.

2013-01-01

Biofilm formation can lead to various consequences in the food processing line such as contamination and equipment breakdowns. Since formation of biofilm can occur in various conditions; this study was carried out using L. monocytogenes ATCC 19112 and its biofilm formation ability tested under various concentrations of sodium chloride and temperatures. Cultures of L. monocytogenes ATCC 19112 were placed in 96-well microtitre plate containing concentration of sodium chloride from 1–10% (w/v) and incubated at different temperature of 4 °C, 30 °C and 45 °C for up to 60 h. Absorbance reading of crystal violet staining showed the density of biofilm formed in the 96-well microtitre plates was significantly higher when incubated in 4 °C. The formation of biofilm also occurs at a faster rate at 4 °C and higher optical density (OD 570 nm) was observed at 45 °C. This shows that storage under formation of biofilm that may lead to a higher contamination along the processing line in the food industry. Formation of biofilm was found to be more dependent on temperature compared to sodium chloride stress. PMID:24159283

Efavirenz directly modulates estrogen receptor and induces breast cancer cell growth

PubMed Central

Sikora, Matthew J.; Rae, James M.; Johnson, Michael D.; Desta, Zeruesenay

2010-01-01

Objectives Efavirenz-based HIV therapy is associated with breast hypertrophy and gynecomastia. Here, we tested the hypothesis that efavirenz induces gynecomastia through direct binding and modulation of estrogen receptor (ER). Methods To determine the effect of efavirenz on growth, the estrogen-dependent, ER-positive breast cancer cell lines MCF-7, T47D and ZR-75-1 were treated with efavirenz under estrogen-free conditions in the presence or absence of the anti-estrogen ICI 182,780. Cells treated with 17β-estradiol in the absence or presence of ICI 182,780 served as positive and negative controls, respectively. Cellular growth was assayed using the crystal violet staining method and an in vitro receptor binding assay was used to measure efavirenz’s ER binding affinity. Results Efavirenz induced growth in MCF-7 cells with an estimated EC50 of 15.7µM. This growth was reversed by ICI 182,780. Further, efavirenz binds directly to ER (IC50 of ~52µM) at roughly 1000-fold higher concentration than observed with E2. Conclusions Our data suggest that efavirenz-induced gynecomastia may be due, at least in part, to drug-induced ER activation in breast tissues. PMID:20408889

Mutation of the cyclic di-GMP phosphodiesterase gene in Burkholderia lata SK875 attenuates virulence and enhances biofilm formation.

PubMed

Jung, Hae-In; Kim, Yun-Jung; Lee, Yun-Jung; Lee, Hee-Soo; Lee, Jung-Kee; Kim, Soo-Ki

2017-10-01

Burkholderia sp. is a gram-negative bacterium that commonly exists in the environment, and can cause diseases in plants, animals, and humans. Here, a transposon mutant library of a Burkholderia lata isolate from a pig with swine respiratory disease in Korea was screened for strains showing attenuated virulence in Caenorhabditis elegans. One such mutant was obtained, and the Tn5 insertion junction was mapped to rpfR, a gene encoding a cyclic di-GMP phosphodiesterase that functions as a receptor. Mutation of rpfR caused a reduction in growth on CPG agar and swimming motility as well as a rough colony morphology on Congo red agar. TLC analysis showed reduced AHL secretion, which was in agreement with the results from plate-based and bioluminescence assays. The mutant strain produced significantly more biofilm detected by crystal violet staining than the parent strain. SEM of the mutant strain clearly showed that the overproduced biofilm contained a filamentous structure. These results suggest that the cyclic di-GMP phosphodiesterase RpfR plays an important role in quorum sensing modulation of the bacterial virulence and biofilm formation.

[Formation of microbial biofilms in causative agents of acute and chronic pyelonephritis].

PubMed

Lagun, L V; Atanasova, Iu V; Tapal'skiĭ, D V

2013-01-01

Study the intensity of formation of microbial biofilms by Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus strains isolated during various forms of pyelonephritis. 150 clinical isolates of microorganisms isolated from urine ofpatientswith acute and chronic pyelonephritiswere included into the study. Determination of intensity of film-formation was carried out by staining of the formed biofilms by crystal violet with consequent extraction of the dye and measurement of its concentration in washout solution. Among causative agents ofpyelonephritis P. aeruginosa isolates had the maximum film-forming ability. The intensity of biofilm formation of these isolates was 2-3 time higher than staphylococcus and enterobacteria strains. Strains isolated from patients with chronic pyelonephritis by ability to form biofilms significantly surpassed strains isolated from acute pyelonephritis patients. A higher ability to form microbial biofilms for microorganisms--causative agents of pyelonephritis progressing against the background ofurolithiasis was noted. The ability to form biofilms is determined by both causative agent species and character of the infectious process in which this microorganism participates. Intensive formation of biofilms by E. coli, P. aeruginosa, K. pneumoniae, S. aureus clinical isolates may be an important factor of chronization of urinary tract infections.

Subinhibitory concentrations of cell wall synthesis inhibitors promote biofilm formation of Enterococcus faecalis

NASA Astrophysics Data System (ADS)

Yu, Wen; Hallinen, Kelsey; Wood, Kevin

Enterococcus faecalis are commonly associated with hospital acquired infections, because they readily form biofilms on instruments and medical devices. Biofilms are inherently more resistant to killing by antibiotics compared to planktonic bacteria, in part because of their heterogeneous spatial structure. Surprisingly, however, subminimal inhibitory concentrations (sub-MICs) of some antibiotics can actually promote biofilm formation. Unfortunately, much is still unknown about how low drug doses affect the composition and spatial structure of the biofilm. In this work, we investigate the effects of sub-MICs of ampicillin on the formation of E. faecalis biofilms. First, we quantified biofilm mass using crystal violet staining in polystyrene microtiter plates. We found that total biofilm mass is increased over a narrow range of ampicillin concentrations before ultimately declining at higher concentrations. Second, we show that sub-MICs of ampicillin can increase mass of E. faecalis biofilms while simultaneously increasing extracellular DNA/RNA and changing total number of viable cells under confocal microscopy. Further, we use RNA-seq to identify genes differentially expressed under sub-MICs of ampicillin. Finally, we show a mathematical model to explain this phenomenon. This work was funded by The Hartwell Foundation Individual Biomedical Research Award and NSF CAREER 1553208 to KBW.

How to Study Biofilms after Microbial Colonization of Materials Used in Orthopaedic Implants.

PubMed

Drago, Lorenzo; Agrappi, Serse; Bortolin, Monica; Toscano, Marco; Romanò, Carlo Luca; De Vecchi, Elena

2016-02-26

Over the years, various techniques have been proposed for the quantitative evaluation of microbial biofilms. Spectrophotometry after crystal violet staining is a widespread method for biofilm evaluation, but several data indicate that it does not guarantee a good specificity, although it is rather easy to use and cost saving. Confocal laser microscopy is one of the most sensitive and specific tools to study biofilms, and it is largely used for research. However, in some cases, no quantitative measurement of the matrix thickness or of the amount of embedded microorganisms has been performed, due to limitation in availability of dedicated software. For this reason, we have developed a protocol to evaluate the microbial biofilm formed on sandblasted titanium used for orthopaedic implants, that allows measurement of biomass volume and the amount of included cells. Results indicate good reproducibility in terms of measurement of biomass and microbial cells. Moreover, this protocol has proved to be applicable for evaluation of the efficacy of different anti-biofilm treatments used in the orthopaedic setting. Summing up, the protocol here described is a valid and inexpensive method for the study of microbial biofilm on prosthetic implant materials.

Helicobacter pylori-Negative Primary Rectal MALT Lymphoma: Complete Remission after Radiotherapy

PubMed Central

Okamura, Takuma; Suga, Tomoaki; Iwaya, Yugo; Ito, Tetsuya; Yokosawa, Shuichi; Arakura, Norikazu; Ota, Hiroyoshi; Tanaka, Eiji

2012-01-01

Rectal mucosa-associated lymphoid tissue (MALT) lymphoma is a rare condition. Although the majority of patients undergo surgical resection, a definitive treatment for rectal MALT lymphoma has not yet been established. In the present study, we report the outcome of radiotherapy in 3 patients with rectal MALT lymphoma. Our cohort ranged from 56 to 65 years of age. The male/female ratio was 1:2, and all patients were in stage I (Lugano classification) of the disease. Endoscopic findings revealed elevated lesions resembling submucosal tumors in 2 patients, and a sessile elevated lesion with a nodular surface in 1 patient. One of the 3 patients underwent magnifying endoscopy with crystal violet staining that demonstrated a type I pit pattern (Kudo's classification) lesion with a broad intervening area caused by the upthrust of the tumor from the submucosa. All patients tolerated radiotherapy at doses of 30 Gy without major complications and achieved complete remission. Follow-up ranged from 13 to 75 months (mean 51.0 months), revealing no recurrence of MALT lymphoma. As such, we propose radiotherapy to be a safe and effective means for treating rectal MALT lymphoma. PMID:22754493

Candida tropicalis biofilms: artificial urine, urinary catheters and flow model.

PubMed

Negri, Melyssa; Silva, Sónia; Henriques, Mariana; Azeredo, Joana; Svidzinski, Terezinha; Oliveira, Rosário

2011-10-01

Adhesion to medical devices and biofilm formation are considered important virulence factors of Candida tropicalis. This work aimed to use artificial urine (AU) and urinary catheters, under flow conditions, for studying C. tropicalis biofilms. Adhesion and biofilm formation on silicone and latex urinary catheters were quantified by crystal violet staining and determination of colony forming units. Candida surface hydrophobicity was also evaluated, as well as the biofilms' matrix content in terms of proteins and carbohydrates. Candida tropicalis was able to adhere and to form biofilms along the entire length of the catheters under flow conditions. It was found that the isolate U69 adhered significantly more to both types of catheters than did the reference strain. However, U69 biofilms contained significantly less cultivable cells and higher biofilm biomass than those of the reference strain. Detachment of cells from biofilms on latex catheter was lower compared to silicone catheter. This model using AU appeared to be suitable for studies mimicking the real body conditions. Additionally, C. tropicalis was in fact able to colonize urinary catheters in the presence of AU and to detach from these catheters, demonstrating their capacity to colonize distal sites.

Novel Method for Quantitative Estimation of Biofilms.

PubMed

Syal, Kirtimaan

2017-10-01

Biofilm protects bacteria from stress and hostile environment. Crystal violet (CV) assay is the most popular method for biofilm determination adopted by different laboratories so far. However, biofilm layer formed at the liquid-air interphase known as pellicle is extremely sensitive to its washing and staining steps. Early phase biofilms are also prone to damage by the latter steps. In bacteria like mycobacteria, biofilm formation occurs largely at the liquid-air interphase which is susceptible to loss. In the proposed protocol, loss of such biofilm layer was prevented. In place of inverting and discarding the media which can lead to the loss of the aerobic biofilm layer in CV assay, media was removed from the formed biofilm with the help of a syringe and biofilm layer was allowed to dry. The staining and washing steps were avoided, and an organic solvent-tetrahydrofuran (THF) was deployed to dissolve the biofilm, and the absorbance was recorded at 595 nm. The protocol was tested for biofilm estimation of E. coli, B. subtilis and M. smegmatis, and compared with the traditional CV assays. Isoniazid drug molecule, a known inhibitor of M. smegmatis biofilm, was tested and its inhibitory effects were quantified by the proposed protocol. For ease in referring, this method has been described as the Syal method for biofilm quantification. This new method was found to be useful for the estimation of early phase biofilm and aerobic biofilm layer formed at the liquid-air interphase. The biofilms formed by all three tested bacteria-B. subtilis, E. coli and M. smegmatis, were precisely quantified.

Combining biofilm matrix measurements with biomass and viability assays in susceptibility assessments of antimicrobials against Staphylococcus aureus biofilms.

PubMed

Skogman, Malena Elise; Vuorela, Pia Maarit; Fallarero, Adyary

2012-09-01

Despite that three types of assays (measuring biofilm viability, biomass, or matrix) are described to assess anti-biofilm activity, they are rarely used together. As infections can easily reappear if the matrix is not affected after antibiotic treatments, our goal was to explore the simultaneous effects of antibiotics on the viability, biomass and matrix of Staphylococcus aureus biofilms (ATCC 25923). Viability and biomass were quantified using resazurin and crystal violet staining sequentially in the same plate, while matrix staining was conducted with a wheat germ agglutinin-Alexa Fluor 488 fluorescent conjugate. Establishment of the detection limits and linearity ranges allowed concluding that all three methods were able to estimate biofilm formation in a similar fashion. In a susceptibility study with 18-h biofilms, two model compounds (penicillin G and ciprofloxacin) caused a reduction on the viability and biomass accompanied by an increase or not changed levels of the matrix, respectively. This response pattern was also proven for S. aureus Newman, S. epidermidis and E. coli biofilms. A classification of antibiotics based on five categories according to their effects on viability and matrix has been proposed earlier. Our data suggests a sixth group, represented by penicillin, causing decrease in bacterial viability but showing stimulatory effects on the matrix. Further, if effects on the matrix are not taken into account, the long-term chemotherapeutic effect of antibiotics can be jeopardized in spite of the positive effects on biofilms viability and biomass. Thus, measuring all these three endpoints simultaneously provide a more complete and accurate picture.

Spectral, electron microscopic and chemical investigations of gamma-induced purple color zonings in amethyst crystals from the Dursunbey-Balıkesir region of Turkey

NASA Astrophysics Data System (ADS)

Hatipoğlu, Murat; Kibar, Rana; Çetin, Ahmet; Can, Nurdoğan; Helvacı, Cahit; Derin, H.

2011-07-01

Amethyst crystals on matrix specimens from the Dursunbey-Balıkesir region in Turkey have five representative purple color zonings: dark purple, light purple, lilac, orchid, and violet. The purple color zonings have been analyzed with optical absorption spectra in the visible wavelength region, chemical full trace element analyses (inductively coupled plasma-atomic emission spectroscopy and inductively coupled plasma-mass spectroscopy), and scanning electron microscopic images with high magnification. It can be proposed that the production of the purple color in amethyst crystals is due to three dominant absorption bands centered at 375, 530, and 675 nm, respectively. In addition, the purple color zonings are also due to four minor absorption bands centered at 435, 480, 620, and 760 nm. X-ray diffraction graphics of the investigated amethyst crystals indicate that these crystals are composed of a nearly pure alpha-quartz phase and do not include any moganite silica phase and/or other mineral implications. Trace element analyses of the amethyst crystals show five representative purple color zonings, suggesting that the absorption bands can be mainly attributed to extrinsic defects (chemical impurities). However, another important factor that influences all structural defects in amethyst is likely to be the gamma irradiation that exists during amethyst crystallization and its inclusion in host materials. This gamma irradiation originates from the large underlying intrusive granitoid body in the region of amethyst formation. Irradiation modifies the valence values of the impurity elements in the amethyst crystals. It is observed that the violet-colored amethyst crystals have the most stable and the least reversible coloration when exposed to strong light sources. This situation can be related to the higher impurity content of Fe (2.50 ppm), Co (3.1 ppm), Ni (38 ppm), Cu (17.9 ppm), Zn (10 ppm), Zr (3.9 ppm), and Mo (21.8 ppm).

A Fresh Look at the Crystal Violet Lab with Handheld Camera Colorimetry

ERIC Educational Resources Information Center

Knutson, Theodore R.; Knutson, Cassandra M.; Mozzetti, Abbie R.; Campos, Antonio R.; Haynes, Christy L.; Penn, R. Lee

2015-01-01

Chemical kinetic experiments to determine rate laws are common in high school and college chemistry courses. For reactions involving a color change, rate laws can be determined experimentally using spectrophotometric or colorimetric equipment though this equipment can be cost prohibitive. Previous work demonstrated that inexpensive handheld camera…

Biofilm formation by environmental isolates of Salmonella and their sensitivity to natural antimicrobials

USDA-ARS?s Scientific Manuscript database

We evaluated 15 Salmonella isolates; S. Derby (2), S. Infantis (4), and S. Typhimurium (9) from conventional swine farm environment (soil and lagoon) for biofilm formation. Biofilm forming ability was determined by 96-well microtitre plate Crystal-Violet and Minimum Biofilm Eradication Concentration...

Live cell imaging reveals extensive intracellular cytoplasmic colonization of banana by normally non-cultivable endophytic bacteria.

PubMed

Thomas, Pious; Sekhar, Aparna Chandra

2014-01-01

It is generally believed that endophytic microorganisms are intercellular inhabitants present in either cultivable or non-cultivable form primarily as root colonizers. The objective of this study was to determine whether the actively mobile micro-particles observed in the intracellular matrix of fresh tissue sections of banana included endophytic bacteria. Tissue sections (50-100 µm) from apical leaf sheaths of surface-disinfected suckers (cv. Grand Naine) displayed 'Brownian motion'-reminiscent abundant motile micro-particles under bright-field and phase-contrast (×1000), which appeared similar in size and motility to the pure cultures of endophytes previously isolated from banana. Observations on callus, embryonic cells and protoplasts with intact cell wall/plasma membrane confirmed their cytoplasmic nature. The motility of these entities reduced or ceased upon tissue fixation or staining with safranin/crystal violet (0.5 % w/v), but continued uninterrupted following treatment with actin-disrupting drugs, ruling out the possibility of micro-organelles like peroxisomes. Staining with 2,3,5-triphenyl tetrazolium chloride (TTC) confirmed them to be live bacteria with similar observations after dilute safranin (0.005 %) treatment. Tissue staining with SYTO-9 coupled with epi-fluorescence or confocal laser scanning microscopy showed bacterial colonization along the peri-space between cell wall and plasma membrane initially. SYTO-9 counterstaining on TTC- or safranin-treated tissue and those subjected to enzymatic permeabilization revealed the cytoplasmic bacteria. These included organisms moving freely in the cytoplasm and those adhering to the nuclear envelope or vacuoles and the intravacuolar colonizers. The observations appeared ubiquitous to different genomes and genotypes of banana. Plating the tissue homogenate on nutrient media seldom yielded colony growth. This study, supported largely by live cell video-imaging, demonstrates enormous intracellular colonization in bananas by normally non-cultivable endophytic bacteria in two niches, namely cytoplasmic and periplasmic, designated as 'Cytobacts' and 'Peribacts', respectively. The integral intracellular association with their clonal perpetuation suggests a mutualistic relationship between endophytes and the host.

Live cell imaging reveals extensive intracellular cytoplasmic colonization of banana by normally non-cultivable endophytic bacteria

PubMed Central

Thomas, Pious; Sekhar, Aparna Chandra

2014-01-01

It is generally believed that endophytic microorganisms are intercellular inhabitants present in either cultivable or non-cultivable form primarily as root colonizers. The objective of this study was to determine whether the actively mobile micro-particles observed in the intracellular matrix of fresh tissue sections of banana included endophytic bacteria. Tissue sections (50–100 µm) from apical leaf sheaths of surface-disinfected suckers (cv. Grand Naine) displayed ‘Brownian motion’-reminiscent abundant motile micro-particles under bright-field and phase-contrast (×1000), which appeared similar in size and motility to the pure cultures of endophytes previously isolated from banana. Observations on callus, embryonic cells and protoplasts with intact cell wall/plasma membrane confirmed their cytoplasmic nature. The motility of these entities reduced or ceased upon tissue fixation or staining with safranin/crystal violet (0.5 % w/v), but continued uninterrupted following treatment with actin-disrupting drugs, ruling out the possibility of micro-organelles like peroxisomes. Staining with 2,3,5-triphenyl tetrazolium chloride (TTC) confirmed them to be live bacteria with similar observations after dilute safranin (0.005 %) treatment. Tissue staining with SYTO-9 coupled with epi-fluorescence or confocal laser scanning microscopy showed bacterial colonization along the peri-space between cell wall and plasma membrane initially. SYTO-9 counterstaining on TTC- or safranin-treated tissue and those subjected to enzymatic permeabilization revealed the cytoplasmic bacteria. These included organisms moving freely in the cytoplasm and those adhering to the nuclear envelope or vacuoles and the intravacuolar colonizers. The observations appeared ubiquitous to different genomes and genotypes of banana. Plating the tissue homogenate on nutrient media seldom yielded colony growth. This study, supported largely by live cell video-imaging, demonstrates enormous intracellular colonization in bananas by normally non-cultivable endophytic bacteria in two niches, namely cytoplasmic and periplasmic, designated as ‘Cytobacts’ and ‘Peribacts’, respectively. The integral intracellular association with their clonal perpetuation suggests a mutualistic relationship between endophytes and the host. PMID:24790123

Hematoxylin shortages: their causes and duration, and other dyes that can replace hemalum in routine hematoxylin and eosin staining.

PubMed

Dapson, R; Horobin, R W; Kiernan, J

2010-02-01

The origins of repeated hematoxylin shortages are outlined. Lack of integration in the hematoxylin trade exacerbates the problems inherent in using a natural product. Separate corporations are engaged in tree growth and harvesting, dye extraction, processing of extracts to yield hematoxylin, and formulation and sale of hematoxylin staining solutions to the end users in biomedical laboratories. Hematoxylin has many uses in biological staining and no single dye can replace it for all applications. Probably, the most satisfactory substitutes for aluminum-hematoxylin (hemalum) are the ferric complexes of celestine blue (CI 51050; mordant blue 14) and eriochrome cyanine R (CI 43820; mordant blue 3, also known as chromoxane cyanine R and solochrome cyanine R). The iron-celestine blue complex is a cationic dye that binds to nucleic acids and other polyanions, such as those of cartilage matrix and mast cell granules. Complexes of iron with eriochrome cyanine R are anionic and give selective nuclear staining similar to that obtained with acidic hemalum solutions. Iron complexes of gallein (CI 45445; mordant violet 25), a hydroxyxanthene dye, can replace iron-hematoxylin in formulations for staining nuclei, myelin, and protozoa.

Treatment of oral thrush in HIV/AIDS patients with lemon juice and lemon grass (Cymbopogon citratus) and gentian violet.

PubMed

Wright, S C; Maree, J E; Sibanyoni, M

2009-03-01

The purpose of the study was to investigate the safety and efficacy of lemon juice and lemon grass (Cymbopogon citratus) in the treatment of oral thrush in HIV/AIDS patients when compared with the control group using gentian violet aqueous solution 0.5%. Oral thrush is a frequent complication of HIV infection. In the Moretele Hospice, due to financial constraints, the treatment routinely given to patients with oral thrush is either lemon juice directly into the mouth or a lemon grass infusion made from lemon grass (Cymbopogon citratus) grown and dried at the hospice. These two remedies have been found to be very efficacious therefore are used extensively. Gentian violet, the first line medication for oral thrush in South Africa, is not preferred by the primary health clinic patients due to the visible purple stain which leads them to being stigmatized as HIV-positive. Cymbopogon citratus and Citrus limon have known antifungal properties. The study design was a randomised controlled trial. Ninety patients were randomly assigned to one of three groups: gentian violet, lemon juice or lemon grass. Inclusion criteria included being HIV-positive with a diagnosis of oral thrush. The study period was 11 days and patients were followed up every second day. International ethical principles were adhered to during the study. Of the 90 patients, 83 completed the study. In the intention-to-treat analysis, none of the p-values were significant therefore the null hypothesis could not be rejected. In the analysis of the participants who actually completed the trial, the lemon juice showed better results than the gentian violet aqueous solution 0.5% in the treatment of oral thrush in an HIV-positive population (p<0.02). The null hypothesis in terms of the lemon grass and gentian violet could also be rejected on the basis of the Chi-square test and the likelihood ratio test (p<0.05). Though the patient population was small, the use of lemon juice and lemon grass for the treatment of oral candidiasis in an HIV population was validated by the randomised controlled trial.

A bivalent cationic dye enabling selective photo-inactivation against Gram-negative bacteria.

PubMed

Li, Ke; Zhang, Yang-Yang; Jiang, Guo-Yu; Hou, Yuan-Jun; Zhang, Bao-Wen; Zhou, Qian-Xiong; Wang, Xue-Song

2015-05-07

A piperazine-modified Crystal Violet was found to be able to selectively inactivate Gram-negative bacteria upon visible light irradiation but left Gram-positive bacteria less damaged, which can serve as a blueprint for the development of novel narrow-spectrum agents to replenish the current arsenal of photodynamic antimicrobial chemotherapy (PACT).

A chemometric-assisted method for the simultaneous determination of malachite green and crystal violet in water based on absorbance-pH data generated by a homemade pH gradient apparatus.

PubMed

Yu, Shuling; Yuan, Xuejie; Yang, Jing; Yuan, Jintao; Shi, Jiahua; Wang, Yali; Chen, Yuewen; Gao, Shufang

2015-01-01

An attractive method of generating second-order data was developed by a dropping technique to generate pH gradient simultaneously coupled with diode-array spectrophotometer scanning. A homemade apparatus designed for the pH gradient. The method and the homemade apparatus were used to simultaneously determine malachite green (MG) and crystal violet (CV) in water samples. The absorbance-pH second-order data of MG or CV were obtained from the spectra of MG or CV in a series of pH values of HCl-KCl solution. The second-order data of mixtures containing MG and CV that coexisted with interferents were analyzed using multidimensional partial least-squares with residual bilinearization. The method and homemade apparatus were used to simultaneously determine MG and CV in fish farming water samples and in river ones with satisfactory results. The presented method and the homemade apparatus could serve as an alternative tool to handle some analysis problems. Copyright © 2015 Elsevier B.V. All rights reserved.

Adsorption of crystal violet with diatomite earth&carbon by a modification of hydrothermal carbonization process.

PubMed

Zhang, Yanzhuo; Li, Jun; Chen, Guanghui; Bian, Wei; Lu, Yun; Li, Wenjing; Zheng, Zhaoming; Cheng, Xiaojie

2016-01-01

The high colority and difficulty of decolorization are the most important tasks on printing and dyeing wastewater. This study investigates the ability of diatomite earth&carbon (DE&C) as an adsorbent to removal crystal violet (CV) from aqueous solutions. Fourier transform infrared spectroscopy results indicate the importance of functional groups during the adsorption of CV. The obtained N2 adsorption-desorption isotherm values accord with well IUPAC type II. Our calculations determined a surface area of 73.15 m(2) g(-1) for DE&C and an average pore diameter of 10.56 nm. Equilibrium data of the adsorption process fitted very well to the Langmuir model (R(2) > 0.99). The results of kinetics study showed that the pseudo-second-order model fitted to the experimental data well. The thermodynamic parameters were also evaluated. ΔH° <0, ΔS° > 0 and ΔG° < 0 demonstrated that the adsorption process was spontaneous and exothermic for dye. Furthermore the positive value of ΔS° reflected good affinity of the CV dye.

Making Porous Luminescent Regions In Silicon Wafers

NASA Technical Reports Server (NTRS)

Fathauer, Robert W.; Jones, Eric W.

1994-01-01

Regions damaged by ion implantation stain-etched. Porous regions within single-crystal silicon wafers fabricated by straightforward stain-etching process. Regions exhibit visible photoluminescence at room temperature and might constitute basis of novel class of optoelectronic devices. Stain-etching process has advantages over recently investigated anodic-etching process. Process works on both n-doped and p-doped silicon wafers. Related development reported in article, "Porous Si(x)Ge(1-x) Layers Within Single Crystals of Si," (NPO-18836).

Survey of the Antibiofilm and Antimicrobial Effects of Zingiber officinale (in Vitro Study).

PubMed

Aghazadeh, Marzieh; Zahedi Bialvaei, Abed; Aghazadeh, Mohammad; Kabiri, Fahimeh; Saliani, Negar; Yousefi, Mehdi; Eslami, Hosein; Samadi Kafil, Hossein

2016-02-01

Candidiasis is one of the most prevalent and important opportunistic fungal infections of the oral cavity caused by Candida yeast species like Candida albicans, C. glabrata, and C. krusei. In addition, several bacteria can cause oral infections. The inhibition of microbial biofilm is the best way to prevent oral infections. The aim of the present study is to evaluate the antifungal, antimicrobial, and anti-biofilm properties of ginger (Zingiber officinale) extract against Candida species and some bacterial pathogens and the extract's effects on biofilm formation. Ginger ethanolic extract as a potential mouthwash was used to evaluate its effect against fungi and bacteria using the microdilution method, and biofilm was evaluated using the crystal violet staining method and dead/alive staining. MTT assay was used to evaluate the possible cytotoxicity effects of the extract. The minimum inhibitory concentrations (MICs) of ginger extract for evaluated strains were 40, 40, 20, 20, 20, 20, 10, and 5 mg/mL for Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus cereus, Acinetobacter baumannii, C. albicans, and C. krusei, respectively. Ginger extract successfully inhibited biofilm formation by A. baumannii, B. cereus, C. krusei, and C. albicans. MTT assay revealed no significant reduction in cell viability after 24 hours. The minimum inhibitory biofilm concentrations (MIBCs) of ginger extract for fungi strains (C. krusei and C. albicans) were greater than those of fluconazole and nystatin (P = 0.000). The findings of the present study indicate that ginger extract has good antifungal and antibiofilm formation by fungi against C. albicans and C. Krusei. Concentrations between 0.625 mg/mL and 5 mg/mL had the highest antibiofilm and antifungal effects. Perhaps, the use of herbal extracts such as ginger represents a new era for antimicrobial therapy after developing antibiotic resistance in microbes.

EFFECTS OF AQUATIC HUMIC SUBSTANCES ON ANALYSIS FOR HYDROGEN PEROXIDE USING PEROXIDASE-CATALYZED OXIDATIONS OF TRIARYLMETHANES OR P-HYDROXYPENYLACETIC ACID (JOURNAL VERSION)

EPA Science Inventory

A sensitive procedure is described for trace analysis of hydrogen peroxide in water. The process involves the peroxide-catalyzed oxidation of the leuco forms of two dyes, crystal violet and malachite green. The sensitivity of this procedure, as well as of another procedure based ...

Effects of Cola-Flavored Beverages and Caffeine on Streptococcus mutans Biofilm Formation and Metabolic Activity.

PubMed

Dotsey, Roger P; Moser, Elizabeth A S; Eckert, George J; Gregory, Richard L

To examine the effects of cola-flavored beverages and caffeine on growth and metabolism of Streptococcus mutans biofilm. This study was designed to determine if carbonated beverages or caffeine can increase S. mutans growth and biofilm formation and metabolic activity in vitro, potentially leading to increased S. mutans-associated cariogenicity in children that consume them. Six different cola-flavored products, plus pure caffeine, and pure high fructose corn syrup (HFCS), at different concentrations similar to those in the beverages were tested. A 16-hour culture of S. mutans was treated with different dilutions in bacteriological media. To test for the effect on biofilm formation, the biofilm was stained with crystal violet. The absorbance was determined to evaluate biofilm growth. Biofilm metabolic activity was measured based on biofilm having the ability to reduce XTT to a water-soluble orange compound. The inclusion of HFCS in the beverages, as well as pure HFCS, significantly enhanced bacterial biofilm formation and metabolic activity. Pure caffeine and the presence of caffeine in beverages did not significantly increase biofilm formation, but pure caffeine significantly increased metabolism, and Diet Coke had significantly greater metabolic activity than Caffeine-Free Diet Coke. HFCS increases both the biofilm formation and metabolism of S. mutans, and caffeine in some cases increases metabolism of S. mutans.

[Effect of exogenous androgen on structures of sexually dimorphism nucleus in preoptic area and anteroventral periventricular nucleus before sexual differentiation in female rats].

PubMed

Huang, Man-li; Wei, Ning; Hu, Jian-bo; Xu, Yi

2008-09-01

To investigate the effects of androgen on sexually dimorphism nucleus in preoptic area (SDN-POA) and anteroventral periventricular nucleus (AVPV) before sexual differentiation of the brain in female rats. Neonatal female SD rats (n=12) were randomly divided into two groups: androgen group and control group. Twenty-four hours after birth animals were subjected to intraperitoneal injection of 50 microl of testosterone propionate (TP,10.0 g/L) or aseptic oil as control. The rats were sacrificed 60 days after the injection and the brains were collected for crystal violet staining. LEICA Q Win system was applied in detecting the boundaries of SDN-POA and AVPV, then the volumes of SDN-POA and AVPV were calculated. The volumes of SDN-POA in androgen group were significantly larger than those in control group [(16.77+/-2.68) vs (8.99+/-1.42)mm(3)x10(-3), P<0.01], while the volumes of AVPV in androgen group were significantly smaller than those in control group [(9.14+/-1.16) vs (14.62+/-2.80)mm(3)x10(-3), P<0.01]. Exogenous androgen rendered before sexual differentiation in female rats results in enlargement of SDN-POA volumes and reduction of AVPV.

High potential of adhesion to biotic and abiotic surfaces by opportunistic Staphylococcus aureus strains isolated from orthodontic appliances.

PubMed

Merghni, Abderrahmen; Ben Nejma, Mouna; Dallel, Ines; Tobji, Samir; Ben Amor, Adel; Janel, Sébastien; Lafont, Frank; Aouni, Mahjoub; Mastouri, Maha

2016-02-01

Orthodontic and other oral appliances act as reservoir of opportunistic pathogens that can easily become resistant to antibiotics and cause systemic infections. The aim of this study was to investigate the ability of Staphylococcus aureus strains isolated from healthy patients with orthodontic appliances, to adhere to biotic (HeLa cells) and abiotic surfaces (polystyrene and dental alloy). Adhesive ability to polystyrene was tested by crystal violet staining and quantitative biofilm production on dental alloy surfaces was evaluated by MTT reduction assay. In addition, the presence of icaA and icaD genes was achieved by polymerase chain reaction (PCR). Qualitative biofilm production revealed that 70.6% of strains were slime producers. The metabolic activity of S. aureus biofilms on dental alloy surfaces was high and did not differ between tested strains. Moreover, all the isolates were adhesive to HeLa cells and 94% of them harbor icaA and icaD genes. Considerable adhesion and internalization capacity to the epithelial HeLa cells and strong biofilm production abilities together, with a high genotypic expression of icaA/icaD genes are an important equipment of S. aureus to colonize orthodontic appliances and eventually to disseminate towards other body areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adhesive properties of environmental Vibrio alginolyticus strains to biotic and abiotic surfaces.

PubMed

Snoussi, Mejdi; Noumi, Emira; Cheriaa, Jihane; Usai, Donatella; Sechi, Leonardo Antonio; Zanetti, Stefania; Bakhrouf, Amina

2008-10-01

The ability of Vibrio alginolyticus strains isolated from a bathing and fishing area (Khenis, Centre of Tunisia) to adhere to both biotic and abiotic surfaces was evaluated in the present work. The biochemical, physiological and enzymatic activities of all strains was also investigated. Three morphotypes of V. alginolyticus were obtained on Congo red agar and only 14 strains produced black colonies. The majority of strains were able to degrade the skin mucus of both Sparus aurata and Dicentrarchus labrax fishes while the fish mucus preparation of these two specimens exhibits a high level of anti-V. alginolyticus strains. Adhesive properties were observed in 37.5% of the analyzed V. alginolyticus strains to Hep-2 cells and 50% to Caco-2 cells. All strains were able to form a purple pellicule on glass tube when they were stained with Crystal violet. Fifteen percent of V. alginolyticus strains (16/32) were strongly adhesive to polystyrene with a values ranging from 3.04 to 18.25 at 595 nm and only four strains were weak biofilm forming. V. alginolyticus bacterium possess a strong adhesive power to both biotic and inertes surfaces. These proprieties may allow to these strains to persist in this biotope in planctonic state or attached to both biotic and abiotic surfaces.

Antimicrobial, antiadhesive and antibiofilm activity of an ethanolic, anthocyanin-rich blueberry extract purified by solid phase extraction.

PubMed

Silva, S; Costa, E M; Mendes, M; Morais, R M; Calhau, C; Pintado, M M

2016-09-01

The present work aimed to characterize the impact of an anthocyanin-rich blueberry extract upon the growth, adhesion and biofilm formation of several pathogens including some multiresistant bacteria. A group comprised of reference strains and clinical multiresistant isolates of Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, Acinetobacter baumannii and Staphylococcus aureus, were used to screen for antimicrobial activity. Microbial growth was determined through the measurement of the optical density while adhesion and biofilm formation was determined using the standard crystal violet staining procedure. The results showed that, while blueberry extract was only effective in hindering the growth of Staph. aureus and E. coli, it was capable of significantly inhibiting biofilm formation and bacterial adhesion for all micro-organisms tested. The extract demonstrated a considerable potential as a natural, alternative antimicrobial capable of either interfering with microbial growth or hamper the adhesion to surfaces, with Staph. aureus proving to be the most susceptible micro-organism. The overall study demonstrates the potential of anthocyanin extracts as natural effective alternative antimicrobial agents. Additionally, the extract's capacity to reduce adhesion without reducing bacterial growth reduces the likeliness of resistance development while reducing the probability of infection. © 2016 The Society for Applied Microbiology.

Fimbriae have distinguishable roles in Proteus mirabilis biofilm formation.

PubMed

Scavone, Paola; Iribarnegaray, Victoria; Caetano, Ana Laura; Schlapp, Geraldine; Härtel, Steffen; Zunino, Pablo

2016-07-01

Proteus mirabilis is one of the most common etiological agents of complicated urinary tract infections, especially those associated with catheterization. This is related to the ability of P. mirabilis to form biofilms on different surfaces. This pathogen encodes 17 putative fimbrial operons, the highest number found in any sequenced bacterial species so far. The present study analyzed the role of four P. mirabilis fimbriae (MR/P, UCA, ATF and PMF) in biofilm formation using isogenic mutants. Experimental approaches included migration over catheter, swimming and swarming motility, the semiquantitative assay based on adhesion and crystal violet staining, and biofilm development by immunofluorescence and confocal microscopy. Different assays were performed using LB or artificial urine. Results indicated that the different fimbriae contribute to the formation of a stable and functional biofilm. Fimbriae revealed particular associated roles. First, all the mutants showed a significantly reduced ability to migrate across urinary catheter sections but neither swimming nor swarming motility were affected. However, some mutants formed smaller biofilms compared with the wild type (MRP and ATF) while others formed significantly larger biofilms (UCA and PMF) showing different bioarchitecture features. It can be concluded that P. mirabilis fimbriae have distinguishable roles in the generation of biofilms, particularly in association with catheters. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dalbavancin reduces biofilms of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE).

PubMed

Knafl, D; Tobudic, S; Cheng, S C; Bellamy, D R; Thalhammer, F

2017-04-01

Activity of dalbavancin against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) in biofilm was investigated and the microbicidal biofilm concentrations (MBC) were determined. Biofilms obtained from ten MRSA and ten MRSE bloodstream isolates, collected from patients in the General Hospital of Vienna between 2012 and 2015, were incubated with dalbavancin in trypticase soy broth (TSB) in serial dilution from 0.0625 mg/l to 256 mg/l using a microtiter plate biofilm model. The plates were incubated for 24 h at 37 ° C and 50% humidity. Biofilms were fixed with 2.5% glutaraldehyde and stained with crystal violet. Subsequently the optical density (OD 620 ) was used to measure the MBC, defined as the concentration of dalbavancin leading to a 50% reduction of biofilm. MBC for MRSA was 1 mg/l-4 mg/l (minimal inhibitory concentrations (MIC) 0.0312 mg/l-0.064 mg/l). MBC for MRSE was 2 mg/l-16 mg/l (MIC 0.023 mg/l-0.0625 mg/l). Dalbavancin successfully reduced MRSA and MRSE in biofilms, and therefore provides a promising option for the treatment of biofilm-associated infections.

Antibacterial Activity of Orthodontic Cement Containing Quaternary Ammonium Polyethylenimine Nanoparticles Adjacent to Orthodontic Brackets

PubMed Central

Sharon, Eldad; Sharabi, Revital; Eden, Adi; Zabrovsky, Asher; Ben-Gal, Gilad; Sharon, Esi; Houri-Haddad, Yael; Beyth, Nurit

2018-01-01

Enamel demineralization is a common problem found in patients using orthodontic devices, such as orthodontic braces. It was found that Streptoccocus mutans growth increases adjacent to orthodontic devices, which may result in caries development. Incorporated antibacterial quaternary ammonium polyethylenimine (QPEI) nanoparticles were previously shown to be highly efficacious against various bacteria. Combining antibacterial materials in orthodontic cement may be advantageous to prevent bacterial outgrowth adjacent to orthodontic brackets. The aim was to evaluate the efficiency of orthodontic cement containing QPEI nanoparticles in reducing S. mutans and Lactobacillus casei outgrowth adjacent to orthodontic brackets. Orthodontic brackets were bonded to the buccal surfaces of extracted lower incisors. The antibacterial effect on S. mutans and L. casei outgrowth of Neobond bracket adhesive orthodontic cement with and without QPEI nanoparticles was compared. The antibacterial effect was evaluated using crystal violet staining and bacterial count (CFU/mL). The teeth in the experimental group, with the QPEI nanoparticles cement, showed significantly lower optical density (OD) values and CFU counts of S. mutans and L. casei than the teeth in the control group (p < 0.05). Based on the results, it can be concluded that orthodontic cement containing QPEI nanoparticles significantly inhibits S. mutans and L. casei growth around orthodontic brackets. PMID:29584643

Emodin affects biofilm formation and expression of virulence factors in Streptococcus suis ATCC700794.

PubMed

Yang, Yan-Bei; Wang, Shuai; Wang, Chang; Huang, Quan-Yong; Bai, Jing-Wen; Chen, Jian-Qing; Chen, Xue-Ying; Li, Yan-Hua

2015-12-01

Streptococcus suis (S. suis) is a swine pathogen and also a zoonotic agent. In this study, the effects of subinhibitory concentrations (sub-MICs) of emodin on biofilm formation by S. suis ATCC700794 were evaluated. As quantified by crystal violet staining, biofilm formation by S. suis ATCC700794 was dose-dependently decreased after growth with 1/2 MIC, 1/4 MIC, or 1/8 MIC of emodin. By scanning electron microscopy, the structural architecture of the S. suis ATCC700794 biofilms was examined following growth in culture medium supplemented with 1/2 MIC, 1/4 MIC, 1/8 MIC, or 1/16 MIC of emodin. Scanning electron microscopy analysis revealed the potential effect of emodin on biofilm formation by S. suis ATCC700794. The expression of luxS gene and virulence genes in S. suis ATCC700794 was investigated by quantitative RT-PCR. It was found that sub-MICs of emodin significantly decreased the expression of gapdh, sly, fbps, ef, and luxS. However, it was found that sub-MICs of emodin significantly increased the expression of cps2J, mrp, and gdh. These findings showed that sub-MICs of emodin could cause the difference in the expression level of the virulence genes.

In vitro biofilm forming potential of Streptococcus suis isolated from human and swine in China.

PubMed

Dawei, Guo; Liping, Wang; Chengping, Lu

2012-07-01

Streptococcus suis is a swine pathogen and also a zoonotic agent. The formation of biofilms allows S. suis to become persistent colonizers and resist clearance by the host immune system and antibiotics. In this study, biofilm forming potentials of various S. suis strains were characterized by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and tissue culture plates stained with crystal violet. In addition, the effects of five antimicrobial agents on biofilm formation were assayed in this study. S. suis produced biofilms on smooth and rough surface. The nutritional contents including glucose and NaCl in the growth medium modulated biofilm formation. There was a significant difference in their biofilm-forming ability among all 46 S. suis strains. The biofilm-forming potential of S. suis serotype 9 was stronger than type 2 and all other types. However, biofilm formation was inhibited by five commonly used antimicrobial agents, penicillin, erythromycin, azithromycin, ciprofloxacin, and ofloxacin at subinhibitory concentrations, among which inhibition of ciprofloxacin and ofloxacin was stronger than that of other three antimicrobial agents.Our study provides a detailed analysis of biofilm formation potential in S. suis, which is a step towards understanding its role in pathogenesis, and eventually lead to a better understanding of how to eradicate S. suis growing as biofilms with antibiotic therapy.

Corona discharges with water electrospray for Escherichia coli biofilm eradication on a surface.

PubMed

Kovalova, Zuzana; Leroy, Magali; Kirkpatrick, Michael J; Odic, Emmanuel; Machala, Zdenko

2016-12-01

Low-temperature plasma (cold), a new method for the decontamination of surfaces, can be an advantageous alternative to the traditional chemical methods, autoclave or dry heat. Positive and negative corona discharges in air were tested for the eradication of 48-h Escherichia coli biofilms grown on glass slides. The biofilms were treated by cold corona discharge plasma for various exposure times. Water electrospray from the high voltage electrode was applied in some experiments. Thermostatic cultivation of the biofilm, and confocal laser scanning microscopy (CLSM) of the biofilm stained with fluorescent dyes were used for biocidal efficiency quantification. Up to 5 log10 reduction of bacterial concentration in the biofilm was measured by thermostatic cultivation after exposure to both corona discharges for 15min. This decontamination efficiency was significantly enhanced by simultaneous water electrospray through the plasma. CLSM showed that the live/dead ratio after treatment remained almost constant inside the biofilm; only cells on the top layers of the biofilm were affected. DAPI fluorescence showed that biofilm thickness was reduced by about 1/3 upon exposure to the corona discharges with electrospray for 15min. The biofilm biomass loss by about 2/3 was confirmed by crystal violet assay. Copyright © 2016 Elsevier B.V. All rights reserved.

Antibacterial Activity of Orthodontic Cement Containing Quaternary Ammonium Polyethylenimine Nanoparticles Adjacent to Orthodontic Brackets.

PubMed

Sharon, Eldad; Sharabi, Revital; Eden, Adi; Zabrovsky, Asher; Ben-Gal, Gilad; Sharon, Esi; Pietrokovski, Yoav; Houri-Haddad, Yael; Beyth, Nurit

2018-03-27

Enamel demineralization is a common problem found in patients using orthodontic devices, such as orthodontic braces. It was found that Streptoccocus mutans growth increases adjacent to orthodontic devices, which may result in caries development. Incorporated antibacterial quaternary ammonium polyethylenimine (QPEI) nanoparticles were previously shown to be highly efficacious against various bacteria. Combining antibacterial materials in orthodontic cement may be advantageous to prevent bacterial outgrowth adjacent to orthodontic brackets. The aim was to evaluate the efficiency of orthodontic cement containing QPEI nanoparticles in reducing S. mutans and Lactobacillus casei outgrowth adjacent to orthodontic brackets. Orthodontic brackets were bonded to the buccal surfaces of extracted lower incisors. The antibacterial effect on S. mutans and L. casei outgrowth of Neobond bracket adhesive orthodontic cement with and without QPEI nanoparticles was compared. The antibacterial effect was evaluated using crystal violet staining and bacterial count (CFU/mL). The teeth in the experimental group, with the QPEI nanoparticles cement, showed significantly lower optical density (OD) values and CFU counts of S. mutans and L. casei than the teeth in the control group ( p < 0.05). Based on the results, it can be concluded that orthodontic cement containing QPEI nanoparticles significantly inhibits S. mutans and L. casei growth around orthodontic brackets.

Adhesion of Candida albicans to Vanillin Incorporated Self-Curing Orthodontic PMMA Resin.

NASA Astrophysics Data System (ADS)

Zam, K.; Sawaengkit, P.; Thaweboon, S.; Thaweboon, B.

2018-02-01

It has been observed that there is an increase in Candida carriers during the treatment with orthodontic removable appliance. Vanillin is flavouring agent, which is known to have antioxidant and antimicrobial properties. The aim of this study was to evaluate the effect of vanillin incorporated PMMA on adhesion of Candida albicans. A total of 36 orthodontic self-curing PMMA resin samples were fabricated. The samples were divided into 3 groups depending on percentage of vanillin incorporated (0.1%, 0.5% and PMMA without vanillin as control). PMMA samples were coated with saliva. The adhesion assay was performed with C. albicans (ATCC 10231). The adherent yeast cells were stained with crystal violet and counted under microscope by random selection of 3 fields at 10X magnification. The statistical analyses performed by Kruskal Wallis and Mann Whitney non-parametric test. It was found that the PMMA resin samples with vanillin incorporation significantly reduced the adhesion of C. albicans as compared to the control group. This study indicates that vanillin incorporated resin can impede the adhesion of C. albicans to about 45 - 56 %. With further testing and development, vanillin can be employed as an antifungal agent to prevent adhesion of C. albicans to orthodontic self-curing PMMA resin.

Efavirenz directly modulates the oestrogen receptor and induces breast cancer cell growth.

PubMed

Sikora, M J; Rae, J M; Johnson, M D; Desta, Z

2010-10-01

Efavirenz-based HIV therapy is associated with breast hypertrophy and gynaecomastia. Here, we tested the hypothesis that efavirenz induces gynaecomastia through direct binding and modulation of the oestrogen receptor (ER). To determine the effect of efavirenz on growth, the oestrogen-dependent, ER-positive breast cancer cell lines MCF-7, T47D and ZR-75-1 were treated with efavirenz under oestrogen-free conditions in the presence or absence of the anti-oestrogen ICI 182,780. Cells treated with 17β-oestradiol in the absence or presence of ICI 182,780 served as positive and negative controls, respectively. Cellular growth was assayed using the crystal violet staining method and an in vitro receptor binding assay was used to measure the ER binding affinity of efavirenz. Efavirenz induced growth in MCF-7 cells with an estimated effective concentration for half-maximal growth (EC(50)) of 15.7 μM. This growth was reversed by ICI 182,780. Further, efavirenz binds directly to the ER [inhibitory concentration for half maximal binding (IC(50)) of ∼52 μM] at a roughly 1000-fold higher concentration than observed with 17β-oestradiol. Our data suggest that efavirenz-induced gynaecomastia may be caused, at least in part, by drug-induced ER activation in breast tissues.

In Vitro Effects of Sports and Energy Drinks on Streptococcus mutans Biofilm Formation and Metabolic Activity.

PubMed

Vinson, LaQuia A; Goodlett, Amy K; Huang, Ruijie; Eckert, George J; Gregory, Richard L

2017-09-15

Sports and energy drinks are being increasingly consumed and contain large amounts of sugars, which are known to increase Streptococcus mutans biofilm formation and metabolic activity. The purpose of this in vitro study was to investigate the effects of sports and energy drinks on S. mutans biofilm formation and metabolic activity. S. mutans UA159 was cultured with and without a dilution (1:3 ratio) of a variety of sports and energy drinks in bacterial media for 24 hours. The biofilm was washed, fixed, and stained. Biofilm growth was evaluated by reading absorbance of the crystal violet. Biofilm metabolic activity was measured by the biofilm-reducing XTT to a water-soluble orange compound. Gatorade Protein Recovery Shake and Starbucks Doubleshot Espresso Energy were found to significantly increase biofilm (30-fold and 22-fold, respectively) and metabolic activity (2-fold and 3-fold, respectively). However, most of the remaining drinks significantly inhibited biofilm growth and metabolic activity. Several sports and energy drinks, with sugars or sugar substitutes as their main ingredients inhibited S. mutans biofilm formation. Among the drinks evaluated, Gatorade Protein Recovery Chocolate Shake and Starbucks Doubleshot Energy appear to have cariogenic potential since they increased the biofilm formation and metabolic activity of S. mutans.

Biofilms of vaginal Lactobacillus reuteri CRL 1324 and Lactobacillus rhamnosus CRL 1332: kinetics of formation and matrix characterization.

PubMed

Leccese Terraf, María Cecilia; Juárez Tomás, María Silvina; Rault, Lucie; Le Loir, Yves; Even, Sergine; Nader-Macías, María Elena Fátima

2016-09-01

Adhesion and biofilm formation are strain properties that reportedly contribute to the permanence of lactobacilli in the human vagina. The kinetics of biofilm formation and the chemical nature of the biofilm matrix formed by Lactobacillus reuteri CRL (Centro de Referencia para Lactobacilos Culture Collection) 1324 and Lactobacillus rhamnosus CRL 1332, vaginal beneficial strains, were evaluated in this work. Crystal violet-stained microplate assay and techniques of epifluorescence, electron and confocal microscopy were applied. The highest density and complexity of biofilms of both vaginal lactobacilli were observed at 72 h of incubation. Protease, proteinase K, α-chymotrypsin and trypsin treatments efficiently detached L. reuteri CRL 1324 biofilm that was also partially affected by α-amylase. However, L. rhamnosus CRL 1332 biofilm was slightly affected by protease, proteinase K and α-amylase. Confocal microscopy revealed greater amount of polysaccharides in L. rhamnosus CRL 1332 biofilm matrix than in L. reuteri CRL 1324 biofilm matrix. The results indicate that proteins are one of the main components of the L. reuteri CRL 1324 biofilm, while the biofilm matrix of L. rhamnosus CRL 1332 is composed of carbohydrates and proteins. The results obtained support the knowledge, understanding and characterization of two biofilm-forming vaginal Lactobacillus strains.

Anti-infective properties of Lactobacillus fermentum against Staphylococcus aureus and Pseudomonas aeruginosa.

PubMed

Varma, Parvathi; Nisha, N; Dinesh, Kavitha R; Kumar, Anil V; Biswas, Raja

2011-01-01

Surgical wounds and implant-associated Staphylococcus aureus and Pseudomonas aeruginosa infections are often difficult to treat because of limited susceptibility of several of these strains to conventional antibiotics. As a result, there is a constant need for new alternative drugs. The aim of this study was to investigate the antimicrobial properties of Lactobacillus fermentum, a probiotic bacterium, which we have isolated from colonic biopsies. The inhibition of S. aureus and P. aeruginosa growth was evaluated by coincubating with L. fermentum strains. Growth inhibition was tested for several of their clinical isolates using agar well diffusion assays. For biofilm assay S. aureus and P. aeruginosa were grown on the glass slides and in 96-well plates in presence of 2.5 μg/ml culture filtrate of L. fermentum. Biofilms were photographed using confocal microscope or stained with 0.1% crystal violet. Reduction in the cytotoxicity of S. aureus and P. aeruginosa was observed in presence of 2.5 μg/ml L. fermentum-spent media. Using in vitroexperiments, we showed that L. fermentum-secreted compound(s) inhibits the growth, cytotoxicity and biofilm formation of several S. aureus and P. aeruginosa strains. Compound(s) present in the culture supernatant of L. fermentum may have promising applications in treating hospital-acquired infections. Copyright © 2011 S. Karger AG, Basel.

Antifungal activity of silver nanoparticles in combination with nystatin and chlorhexidine digluconate against Candida albicans and Candida glabrata biofilms.

PubMed

Monteiro, Douglas R; Silva, Sónia; Negri, Melyssa; Gorup, Luiz F; de Camargo, Emerson R; Oliveira, Rosário; Barbosa, Debora B; Henriques, Mariana

2013-11-01

Although silver nanoparticles (SN) have been investigated as an alternative to conventional antifungal drugs in the control of Candida-associated denture stomatitis, the antifungal activity of SN in combination with antifungal drugs against Candida biofilms remains unknown. Therefore, the aim of this study was to evaluate the antifungal efficacy of SN in combination with nystatin (NYT) or chlorhexidine digluconate (CHG) against Candida albicans and Candida glabrata biofilms. The drugs alone or combined with SN were applied on mature Candida biofilms (48 h), and after 24 h of treatment their antibiofilm activities were assessed by total biomass quantification (by crystal violet staining) and colony forming units enumeration. The structure of Candida biofilms was analysed by scanning electron microscopy (SEM) images. The data indicated that SN combined with either NYT or CHG demonstrated synergistic antibiofilm activity, and this activity was dependent on the species and on the drug concentrations used. SEM images showed that some drug combinations were able to disrupt Candida biofilms. The results of this study suggest that the combination of SN with NYT or CHG may have clinical implications in the treatment of denture stomatitis. However, further studies are needed before recommending the use of these drugs safely in clinical situations. © 2013 Blackwell Verlag GmbH.

Comparison between Peritoneal Macrophage Activation by Bougainvillea xbuttiana Extract and LPS and/or Interleukins

PubMed Central

2017-01-01

Activation of macrophages may be one of the possible approaches in modulating inflammation. We previously reported that Bougainvillea xbuttiana extract showed an immunomodulatory activity. Here we compare the activation of macrophages exposed to B. xbuttiana extract and compare it with the other treatments such as LPS, IL-4, and IL-10. The cytotoxic effect of extract on peritoneal macrophages was determined by the technique of violet crystal staining. To verify the activation of macrophages we used the tests of vacuolization, hydrogen peroxide production, and percentages of cellular expansion and phagocytosis. The levels of interleukins secreted by macrophages treated with the extract, LPS, and cytokines were determined by the biological assay for the determination of TNF levels and by ELISA for all other interleukins. NO levels were evaluated by colorimetric reactions using Griess reagent. Our results showed that B. xbuttiana extract induced (a) low cytotoxicity percentages, (b) increased vacuolization, hydrogen peroxide production and cell expansion and phagocytosis percentages, and (c) decreased production of TNF-α, IFN-γ, IL-1β, and IL-6 and potentiated production of IL-4, IL-10 and TGF-β. These results suggest that B. xbuttiana extract was able to activate the murine macrophages in a manner similar to those macrophages exposed to IL-4 and IL-10. PMID:29279849

The Role of Ionic Interactions in the Adherence of the S. epidermidis Adhesin SdrF to Prosthetic Material

PubMed Central

Toba, Faustino A.; Visai, Livia; Trivedi, Sheetal; Lowy, Franklin D.

2012-01-01

Staphylococcus epidermidis infections are common complications of prosthetic device implantation. SdrF, a surface protein, appears to play a critical role in the initial colonization step by adhering to type I collagen and Dacron™. The role of ionic interactions in S. epidermidis adherence to prosthetic material was examined. SdrF was cloned and expressed in Lactococcus lactis. The effect of pH, cation concentration and detergents on adherence to different types of plastic surfaces was assessed by crystal violet staining and bacterial cell counting. SdrF, in contrast with controls and other S. epidermidis surface proteins, bound to hydrophobic materials such as polystyrene. Binding was an ionic interaction and was affected by surface charge of the plastic, pH and cation concentration. Adherence of the SdrF construct was increased to positively charged plastics and was reduced by increasing concentrations of Ca2+ and Na+. Binding was optimal at pH 7.4. Kinetic studies demonstrated that the SdrF B domain, as well as one of the B subdomains was sufficient to mediate binding. The SdrF construct also bound more avidly to Goretex™ than the lacotococcal control. SdrF is a multifunctional protein that contributes to prosthetic devices infections by ionic, as well as specific receptor-ligand interactions. PMID:23039791

Room Temperature Synthesis of Highly Monodisperse and Sers-Active Glucose-Reduced Gold Nanoparticles

NASA Astrophysics Data System (ADS)

Boitor, R. A.; Tódor, I. Sz.; Leopold, L. F.; Leopold, N.

2015-07-01

A novel method of synthesizing gold nanoparticles was developed through which glucose-coated nanospheres of high monodispersity were synthesized at room temperature. More than 85% of the nanoparticles showed a mean diameter of 8-9 nm. The nanoparticles were characterized through TEM, UV-Vis absorption spectroscopy, dynamic light scattering (DLS), and Zeta potential measurements and were found to be highly stable in colloidal form over time with a surface potential of -38.7 mV. The nanoparticles also showed a great Raman enhancing factor when they were tested as a surface-enhanced Raman scattering (SERS) substrate on various analytes such as rhodamine 6G, crystal violet chloride, cresyl violet chloride, rose bengal, and the Cu(II) 4-(2-pyridylazo)resorcinol complex at micromolar concentrations.

Growth and characterization of benzyl 4-hydroxybenzoate single crystal by vertical Bridgman technique for optical applications

NASA Astrophysics Data System (ADS)

Solanki, S. Siva Bala; Rajesh, N. P.; Suthan, T.

2018-07-01

The benzyl 4-hydroxybenzoate single crystal has been grown by vertical Bridgman technique. The grown crystal was confirmed by single crystal X-ray diffraction studies. The presence of functional groups in the crystal was confirmed by Fourier transform infrared (FTIR) spectral studies. The thermal behaviour of the grown crystal was analyzed by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetric (DSC) studies. Optical behaviour of the grown benzyl 4-hydroxybenzoate crystal was studied by UV-Vis-NIR spectral analysis. Fluorescence spectrum shows near violet light emission. The second harmonic generation behaviour of benzyl 4-hydroxybenzoate was analyzed. The laser damage threshold value of benzyl 4-hydroxybenzoate was measured as 2.16 GW/cm2. The dielectric measurements of benzyl 4-hydroxybenzoate crystal were carried out with different frequencies 1 kHz to 1 MHz versus different temperatures ranging from 313 to 353 K. Photoconductivity study shows that the grown benzyl 4-hydroxybenzoate crystal belongs to negative photoconductivity property. The mechanical strength of the crystal was calculated by Vickers microhardness study.

Nanostructural origin of blue fluorescence in the mineral karpatite.

PubMed

Potticary, Jason; Jensen, Torsten T; Hall, Simon R

2017-08-29

The colour of crystals is a function of their atomic structure. In the case of organic crystals, it is the spatial relationships between molecules that determine the colour, so the same molecules in the same arrangement should produce crystals of the same colour, regardless of whether they arise geologically or synthetically. There is a naturally-occurring organic crystal known as karpatite which is prized for its beautiful blue fluorescence under ultra-violet illumination. When grown under laboratory conditions however, the crystals fluoresce with an intense green colour. For 20 years, this difference has been thought to be due to chemical impurities in the laboratory-grown material. Using electron microscopy coupled with fluorescence spectroscopy and X-Ray diffraction, we report here that this disparity is instead due to differences in the structure of the crystals at the nanoscale. The results show that in nature, karpatite has a nanotexture that is not present in the synthetic crystals, which enables different photonic pathways and therefore a blue, rather than green colour whilst undergoing fluorescence.

Exploration of Thermochromic Materials Using Experimental and Theoretical Infrared and UV-Visible Spectroscopy

ERIC Educational Resources Information Center

Costello, Kelsey; Doan, Kevin Thinh; Organtini, Kari Lynn; Wilson, John; Boyer, Morgan; Gibbs, Greglynn; Tribe, Lorena

2014-01-01

This laboratory was developed by undergraduate students in collaboration with the course instructor as part of a peer-developed and peer-led lab curriculum in a general chemistry course. The goal was to explore the hypothesis that crystal violet lactone was responsible for the thermochromic properties of a sipping straw using a FT-IR for…

Development of a Real-Time Resistance Measurement for Vibrio parahaemolyticus Detection by the Lecithin-Dependent Hemolysin Gene

PubMed Central

Xiang, Guiming; Pu, Xiaoyun; Jiang, Dongneng; Liu, Linlin; Liu, Chang; Liu, Xiaobo

2013-01-01

The marine bacterium Vibrio parahaemolyticus (V. parahaemolyticus) causes gastroenteritis in humans via the ingestion of raw or undercooked contaminated seafood, and early diagnosis and prompt treatment are important for the prevention of V. parahaemolyticus-related diseases. In this study, a real-time resistance measurement based on loop-mediated isothermal amplification (LAMP), electrochemical ion bonding (Crystal violet and Mg2+), real-time monitoring, and derivative analysis was developed. V. parahaemolyticus DNA was first amplified by LAMP, and the products (DNA and pyrophosphate) represented two types of negative ions that could combine with a positive dye (Crystal violet) and positive ions (Mg2+) to increase the resistance of the reaction liquid. This resistance was measured in real-time using a specially designed resistance electrode, thus permitting the quantitative detection of V. parahaemolyticus. The results were obtained in 1–2 hours, with a minimum bacterial density of 10 CFU.mL−1 and high levels of accuracy (97%), sensitivity (96.08%), and specificity (97.96%) when compared to cultivation methods. Therefore, this simple and rapid method has a potential application in the detection of V. parahaemolyticus on a gene chip or in point-of-care testing. PMID:23991096

Synthesis, crystal growth, optical, thermal, and mechanical properties of a nonlinear optical single crystal: ammonium sulfate hydrogen sulphamate (ASHS)

NASA Astrophysics Data System (ADS)

Sudhakar, K.; Nandhini, S.; Muniyappan, S.; Arumanayagam, T.; Vivek, P.; Murugakoothan, P.

2018-04-01

Ammonium sulfate hydrogen sulphamate (ASHS), an inorganic nonlinear optical crystal, was grown from the aqueous solution by slow evaporation solution growth technique. The single-crystal XRD confirms that the grown single crystal belongs to the orthorhombic system with the space group of Pna21. Powder XRD confirms the crystalline nature and the diffraction planes were indexed. Crystalline perfection of grown crystal was analysed by high-resolution X-ray diffraction rocking curve technique. UV-Vis-NIR studies revealed that ASHS crystal has optical transparency 65% and lower cut-off wavelength at 218 nm. The violet light emission of the crystal was identified by photoluminescence studies. The particle size-dependent second-harmonic generation efficiency for ASHS crystal was evaluated by Kurtz-Perry powder technique using Nd:YAG laser which established the existence of phase matching. Surface laser damage threshold value was evaluated using Nd:YAG laser. Optical homogeneity of the crystal was evaluated using modified channel spectrum method through birefringence study. Thermal analysis reveals that ASHS crystal is stable up to 213 °C. The mechanical behaviour of the ASHS crystal was analysed using Vickers microhardness study.

Structural, chemical and physical properties of pure and La3+ doped L-Threonine acetate crystals

NASA Astrophysics Data System (ADS)

Senthamizhan, A.; Sambathkumar, K.; Nithiyanantham, S.; Venkatachalapathy, M.; Rajkamal, N.

2017-12-01

The pure and La3+ doped L- Threonine crystals can be grown by slow evaporation techniques. The crystal structure were examined through X-Ray diffraction (XRD) analysis, confirmed the P212121 system. The quantitative nature of dopant can be analyzed with Inductively Coupled Plasma (ICP) study. The Fourier Transform Infra-Red (FTIR) and Fourier Transform (FT- Raman) investigations yields the possible stretching/bonding with their functional groups and the qualitative/quantitative nature of both crystals is analyzed. The optical behavior of crystals can be studied through Ultra Violet (UV) - Visible spectrometer. The mechanical, thermal and decomposition studies can be carried out through Vickers hardness test, Thermo Gravometric Analysis (TGA) and Differential Thermal Analysis (DTA). The Non Linear Optical (NLO) properties are found more than Potassium Phosphate (KDP) through Kurtz powders technique. The dielectric and optical absorption studies for both pure and L-doped crystals were studied and interpreted all the properties. The La3+ dopant increases the properties are investigated.

Ag nanoparticles agargel nanocomposites for SERS detection of cultural heritage interest pigments

NASA Astrophysics Data System (ADS)

Amato, F.; Micciche', C.; Cannas, M.; Gelardi, F. M.; Pignataro, B.; Li Vigni, M.; Agnello, S.

2018-02-01

Agarose gel (agargel) composites with commercial and laboratory made silver nanoparticles were prepared by a wet solution method at room temperature. The gel composites were used for pigment extraction and detection by Raman spectroscopy. Red (alizarin) and violet (crystal violet) pigments deposited on paper were extracted by the composites and were investigated by micro-Raman spectroscopy. Evaluation was carried out of the surface-enhanced Raman spectroscopy (SERS) effect induced by the silver nanoparticles embedded in the gel. A kinetic approach as a function of time was used to determine the efficiency of pigments extraction by composites deposition. A non-invasive extraction process of few minutes is demonstrated. This process induces active SERS for both used pigments. The reported results show the full exploitability of agargel silver nanoparticle composites for the extraction of pigments from paper based artworks.

A comparison of visible wavelength reflectance hyperspectral imaging and Acid Black 1 for the detection and identification of blood stained fingerprints.

PubMed

Cadd, Samuel; Li, Bo; Beveridge, Peter; O Hare, William T; Campbell, Andrew; Islam, Meez

2016-07-01

Bloodstains are often encountered at scenes of violent crime and have significant forensic value for criminal investigations. Blood is one of the most commonly encountered types of biological evidence and is the most commonly observed fingerprint contaminant. Presumptive tests are used to test blood stain and blood stained fingerprints are targeted with chemical enhancement methods, such as acid stains, including Acid Black 1, Acid Violet 17 or Acid Yellow 7. Although these techniques successfully visualise ridge detail, they are destructive, do not confirm the presence of blood and can have a negative impact on DNA sampling. A novel application of visible wavelength hyperspectral imaging (HSI) is used for the non-contact, non-destructive detection and identification of blood stained fingerprints on white tiles both before and after wet chemical enhancement using Acid Black 1. The identification was obtained in a non-contact and non-destructive manner, based on the unique visible absorption spectrum of haemoglobin between 400 and 500nm. Results from the exploration of the selectivity of the setup to detect blood against ten other non-blood protein contaminants are also presented. A direct comparison of the effectiveness of HSI with chemical enhancement using Acid Black 1 on white tiles is also shown. Copyright © 2016 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

The Use of Ultra-Violet (UV) Light Emitting Diodes (LEDS) in an Advanced Oxidation Process (AOP) with Brilliant Blue FCF as an Indicator

DTIC Science & Technology

2015-03-26

by low, direct current voltage, which are consistent with portable power sources such as batteries or photovoltaic cells (Crystal IS 2013...of Methylene Blue Adsorption on Power Output .................23 vii UV LED Quartz Lens Adsorption Experiment...29 Effect of Methylene Blue Adsorption on Power Output ............................................29 Figure 5 - Percent reduction of

Switch-on fluorescent strategy based on crystal violet-functionalized CdTe quantum dots for detecting L-cysteine and glutathione in water and urine.

PubMed

Sheng, Zhen; Chen, Ligang

2017-10-01

The concentration of L-cysteine (Cys) and glutathione (GSH) is closely related to the critical risk of various diseases. In our study, a new rapid method for the determination of Cys and GSH in water and urine samples has been developed using a fluorescent probe technique, which was based on crystal violet (CV)-functionalized CdTe quantum dots (QDs). The original QDs emitted fluorescence light, which was turned off upon adding CV. This conjugation of CV and QDs could be attributed to electrostatic interaction between COO - of mercaptopropionic acid (MPA) on the surface of QDs and N + of CV in aqueous solution. In addition, Förster resonance energy transfer (FRET) also occurred between CdTe QDs and CV. After adding Cys or GSH to the solution, Cys or GSH exhibited a stronger binding preference toward Cd 2+ than Cd 2+ -MPA, which disturbed the interaction between MPA and QDs. Thus, most MPA was able to be separated from the surface of QDs because of the participation of Cys or GSH. Then, the fluorescence intensity of the CdTe QDs was enhanced. Good linear relationships were obtained in the range of 0.02-40 μg mL -1 and 0.02-50 μg mL -1 , and the detection limits were calculated as 10.5 ng mL -1 and 8.2 ng mL -1 , for Cys and GSH, respectively. In addition, the concentrations of biological thiols in water and urine samples were determined by the standard addition method using Cys as the standard; the quantitative recoveries were in the range of 97.3-105.8%, and relative standard deviations (RSDs) ranged from 2.5 to 3.7%. The method had several unique properties, such as simplicity, lower cost, high sensitivity, and environmental acceptability. Graphical abstract Crystal violet-functionalized CdTe quantum dots for detecting L-cysteine and glutathione with switch-on fluorescent strategy.

Radiation resistance and loss of crystal violet binding activity in Yersinia enterocolitica suspended in raw ground pork exposed to gamma radiation and modified atmosphere.

PubMed

Bhaduri, Saumya; Sheen, Shiowshuh; Sommers, Christopher H

2014-05-01

Virulence of many foodborne pathogens is directly linked to genes carried on self-replicating extra-chromosomal elements, which can transfer genetic material, both vertically and horizontally, between bacteria of the same and different species. Pathogenic Yersinia enterocolitica harbors a 70-kb virulence plasmid (pYV) that encodes genes for low calcium response, crystal violet (CV) binding, Congo red uptake, autoagglutination (AA), hydrophobicity (HP), type III secretion channels, host immune suppression factors, and biofilm formation. Ionizing radiation and modified atmosphere packaging (MAP) are used to control foodborne pathogens and meat spoilage. In this study, the effect of gamma radiation and modified atmosphere (air, 100% N2 , 75% N2 : 25% CO2 , 50% N2 : 50% CO2 , 25% N2 : 75% CO2 , 100% CO2 ) were examined by using the CV binding phenotype, for the presence or absence of pYV in Y. enterocolitica, suspended in raw ground pork. All Y. enterocolitica serovars used (O:3, O:8, and O5,27) were more sensitive to radiation as the CO2 concentration increased above 50%. Crystal violet binding following a radiation dose of 1.0 kGy, which reduced the Y. enterocolitica serovars >5 log, was greatest in the presence of air (ca. 8%), but was not affected by N2 or CO2 concentration (ca. 5%). Following release from modified atmosphere after irradiation, the loss of CV binding rose from 5% to 8% immediately following irradiation to >30% after outgrowth at 25 °C for 24 h. These results, using Y. enterocolitica as a model system, indicate that the risk of foodborne illness could be affected by the loss of virulence factors when postprocess intervention technologies are used. Provides gamma radiation D10 data for inactivation data for Y. enterocolitica irradiated under modified atmosphere and information to risk assessors regarding the difference between pathogen presence versus actual virulence. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

MRI evaluation and functional assessment of brain injury after hypoxic ischemia in neonatal mice.

PubMed

Adén, Ulrika; Dahlberg, Viktoria; Fredholm, Bertil B; Lai, Li-Ju; Chen, Zhengguan; Bjelke, Börje

2002-05-01

Severe perinatal asphyxia is an important cause of brain injury in the newborn infant. We examined early events after hypoxic ischemia (HI) in the 7-day-old mouse brain by MRI and related them to long-term functional effects and histopathology in the same animals at 4 to 5 weeks of age. HI was induced in 7-day-old CD1 mice by exposure to 8% oxygen for 30 minutes after occlusion of the left common carotid artery. The resulting unilateral focal lesion was evaluated in vivo by MRI (T2 maps and apparent diffusion coefficient maps) at 3, 6, and 24 hours and 5 days after hypoxia. Locomotion and sensorimotor function were analyzed after 3 weeks. Four weeks after HI, the mice were killed, and cresyl violet-stained brain sections were examined morphologically. A decrease in apparent diffusion coefficient values in cortex on the affected side was found at 3 hours after HI. T2 values were significantly increased after 6 hours and remained so for 5 days. Maximal size of the lesion was attained at 3 to 6 hours after HI and declined thereafter. Animals with MRI-detected lesions had decreased forward locomotion, performed worse than controls in the beam-walking test, and showed a unilateral hypotrophy in the cresyl violet-stained brain sections 4 weeks later. The temporal progression of the damage after HI in 7-day-old mice differs from that of the adult brain as judged by MRI. The early lesions detected by MRI were related to functional impairments for these mice in near-adult life.

Practical selection methods for rat and mouse round spermatids without DNA staining by flow cytometric cell sorting.

PubMed

Hayama, Tomonari; Yamaguchi, Tomoyuki; Kato-Itoh, Megumi; Ishii, Yumiko; Mizuno, Naoaki; Umino, Ayumi; Sato, Hideyuki; Sanbo, Makoto; Hamanaka, Sanae; Masaki, Hideki; Hirabayashi, Masumi; Nakauchi, Hiromitsu

2016-06-01

Round spermatid injection (ROSI) into unfertilized oocytes enables a male with a severe spermatogenesis disorder to have children. One limitation of the application of this technique in the clinic is the identification and isolation of round spermatids from testis tissue. Here we developed an efficient and simple method to isolate rodent haploid round spermatids using flow cytometric cell sorting, based on DNA content (stained with Hoechst 33342 or Dye Cycle Violet) or by cell diameter and granularity (forward and side scatter). ROSI was performed with round spermatids selected by flow cytometry, and we obtained healthy offspring from unstained cells. This non-invasive method could therefore be an effective option for breeding domestic animals and human male infertility treatment. Mol. Reprod. Dev. 83: 488-496, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Ring-shaped stain patterns driven by solute reactive mesogens in liquid crystal solution

NASA Astrophysics Data System (ADS)

Cha, Tae Woon; Bulliard, Xavier; Choi, Sang Gun; Lee, Hyoung Sub; Kong, Hyang-Shik; Han, Sang Youn

2014-07-01

We report on the formation of ring-shaped stain patterns in a polymer-stabilized patterned vertical alignment mode liquid crystal display (LCD) during the cell filling process. Through the interpretation of the formation mechanism, an effective way to control its development is provided. Systematic trace of the reactive mesogens reveals that the formation of patterns is strongly related to the segregation of solute mesogens in the stain area. These undesirable patterns can be avoided or controlled by reducing the drop volume at each droplet using an inkjet printing technique, meaning that the printing technique could be a useful solution in display technology. For the formation of ring-shaped patterns, the dragging of reactive mesogens during the spreading of the liquid crystal solution plays a key role in the closed LCD cell.

Virulence plasmid (pYV)-associated expression of phenotypic virulent determinants in pathogenic Yersinia species: a convenient method for monitoring the presence of pYV under culture conditions and its application for...food

USDA-ARS?s Scientific Manuscript database

In Yersinia pestis, Y. pseudotuberculosis, and Y, enterocolitica, phenotypic expression of virulence plasmid (pYV: 70-kb)-associated genetic determinants may include low calcium response (Lcr, pin point colony, size = 0.36 mm), colony morphology (size = 1.13 mm), crystal violet (CV) binding (dark-v...

Correction to: Malachite Green and Crystal Violet Decolorization by Ganoderma lucidum and Pleurotus ostreatus Supernatant and by rGlLCC1 and rPOXA 1B Concentrates: Molecular Docking Analysis.

PubMed

Morales-Álvarez, Edwin D; Rivera-Hoyos, Claudia M; Poveda-Cuevas, Sergio A; Reyes-Guzmán, Edwin A; Pedroza-Rodríguez, Aura M; Reyes-Montaño, Edgar A; Poutou-Piñales, Raúl A

2017-12-01

The original version of this article unfortunately contained a mistake. The replacement image of Fig. 4 provided by the first corresponding author, Aura M. Pedroza-Rodríguez, is incorrect and that the originally submitted Fig. 4 should have been retained. The original article has been corrected.

Virulence plasmid (pYV)-associated expression of phenotypic virulent determinants in pathogenic Yersinia species: a convenient method for monitoring the presence of pYV under culture conditions and its application for....food

USDA-ARS?s Scientific Manuscript database

In Yersinia pestis, Y. pseudotuberculosis, and Y, enterocolitica, phenotypic expression of several virulence plasmid (pYV: 70-kb)-associated genetic determinants may include low calcium response (Lcr, pin point colony, size = 0.36 mm), colony morphology (size = 1.13 mm), crystal violet (CV) binding...

Mesoporous Nb2O5/SiO2 material obtained by sol-gel method and applied as adsorbent of crystal violet dye.

PubMed

Umpierres, Cibele S; Prola, Lizie D T; Adebayo, Matthew A; Lima, Eder C; Dos Reis, Glaydson S; Kunzler, Diego D F; Dotto, G L; Arenas, Leliz T; Benvenutti, Edilson V

2017-03-01

In this work, SiO 2 /Nb 2 O 5 (SiNb) material was prepared using sol-gel method and employed as adsorbent for removal of crystal violet dye (CV). The material was characterized using nitrogen adsorption-desorption isotherms, FTIR spectroscopy, pH pzc , and SEM-EDS. The analysis of N 2 isotherms revealed the presence of micro- and mesopores in the SiNb sample with specific surface area as high as 747 m 2  g -1 . For the CV adsorption process, variations of several parameters such as of pH, temperature, contact time, and concentration of dye of the process were evaluated. The optimum initial pH of the CV dye solution was 7.0. The adsorption kinetic and equilibrium data for CV adsorption were suitably represented by the general-order and Liu models, respectively. The maximum adsorption capacity of the CV dye by SiNb was achieved at 303 K, which attained 116 mg g -1 at this temperaure. Dye effluents were simulated and used to check the applicability of the SiNb material for treatment of effluents - the material showed very good efficiency for decolorization of dye effluents.

Crystal structure, energy transfer and tunable luminescence properties of Ca8ZnCe(PO4)7:Eu2+,Mn2+ phosphor

NASA Astrophysics Data System (ADS)

Ding, Chong; Tang, Wanjun

2018-02-01

Single-phased Ca8ZnCe(PO4)7:Eu2+,Mn2+ phosphors with whitlockite-type structure have been prepared via the combustion-assisted synthesis technique. The XRD pattern show that the as-obtained phosphors crystallize in a trigonal phase with space group of R-3c (161). Ca8ZnCe(PO4)7 host is full of sensitizers (Ce3+) and the Ce3+ emission at different lattice sites has been discussed. The efficient energy transfers from Ce3+ ions to Eu2+/Mn2+ ions and from Eu2+ to Mn2+ have been validated. Under UV excitation, the emitting color of Ca8ZnCe(PO4)7:Eu2+/Mn2+ samples can be modulated from violet blue to green and from violet blue to red-orange by the energy transfers of Ce3+→Eu2+ and Ce3+→Mn2+, respectively. Additionally, white emission has been obtained through adjusting the relative concentrations of Eu2+ and Mn2+ ions in the Ca8ZnCe(PO4)7 host under UV excitation. These results indicate that as-prepared Ca8ZnCe(PO4)7:Eu2+,Mn2+ may be a potential candidate as color-tunable white light-emitting phosphors.

Undifferentiated murine embryonic stem cells used to model the effects of the blue-green algal toxin cylindrospermopsin on preimplantation embryonic cell proliferation.

PubMed

Reid, Katherine J; Lang, Kenneth; Froscio, Suzanne; Humpage, Andrew J; Young, Fiona M

2015-11-01

Undifferentiated mouse embryonic stem cell (mES) proliferation in vitro resembles aspects of in vivo pre-implantation embryonic development. mES were used to assess the embryo-toxicity of cylindrospermopsin (CYN), a water contaminant with an Australian Drinking Water Guideline (ADWG) of 1 μg/L. mES exposed to 0-1 μg/mL CYN for 24-168 h were subjected to an optimised crystal violet viability assay. mES exposed to retinoic acid ± 1 μg/L CYN differentiated into neural-like cells confirmed by morphological examination and RT-PCR for Oct4, Brachyury and Nestin. The CYN No Observed Effect Concentration (OEC) was 0.5 μg/mL, the Lowest OEC was 1 μg/mL (p < 0.001, n = 3), and the IC50 was 0.86 μg/mL after 24 h. The ADWG 1 μg/L CYN did not affect differentiation or proliferation after 72 h, but decreased proliferation after 168 h (p < 0.05). We conclude that higher algal bloom-associated CYN concentrations have the potential to impair in vivo pre-implantation development, and the mES crystal violet assay has broad application to screening environmental toxins. Copyright © 2015 Elsevier Ltd. All rights reserved.

Physicochemcial characteristic of CdS-anchored porous WS2 hybrid in the photocatalytic degradation of crystal violet under UV and visible light irradiation

NASA Astrophysics Data System (ADS)

Vattikuti, S. V. Prabhakar; Ngo, Ich-Long; Byon, Chan

2016-11-01

In this work, we report the synthesis of CdS-incorporated porous WS2 by a simple hydrothermal method. The structural, morphological, and optical properties of the samples were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), high resolution X-ray photoelectron spectroscopy (XPS) and UV-visible spectrometry. The photocatalytic activities were established for degradation of crystal violet (CV) under UV and visible light irradiation. The CdS-incorporated porous WS2 hybrid demonstrated high photocatalytic activity for degradation of CV pollutant compared to pure CdS nanoparticles and porous WS2 sheets. This result implies that the CdS-incorporated porous WS2 promoted more electron-hole pair transformation under UV and visible light irradiation. This significant enhancement of photocatalytic efficiency of CdS-incorporated porous WS2 photocatalyst under visible light can be ascribed to the presence of CdS nanospheres on the meshed-like WS2 sheets which potentially improves absorption in the visible range enabled by surface plasmon resonance effect of CdS nanospheres. The photostability and reusability of the CdS-porous WS2 were examined through recycling experiments.

Use of Standing Gold Nanorods for Detection of Malachite Green and Crystal Violet in Fish by SERS.

PubMed

Chen, Xiaowei; Nguyen, Trang H D; Gu, Liqun; Lin, Mengshi

2017-07-01

With growing consumption of aquaculture products, there is increasing demand on rapid and sensitive techniques that can detect prohibited substances in the seafood products. This study aimed to develop a novel surface-enhanced Raman spectroscopy (SERS) method coupled with simplified extraction protocol and novel gold nanorod (AuNR) substrates to detect banned aquaculture substances (malachite green [MG] and crystal violet [CV]) and their mixture (1:1) in aqueous solution and fish samples. Multivariate statistical tools such as principal component analysis (PCA) and partial least squares regression (PLSR) were used in data analysis. PCA results demonstrate that SERS can distinguish MG, CV and their mixture (1:1) in aqueous solution and in fish samples. The detection limit of SERS coupled with standing AuNR substrates is 1 ppb for both MG and CV in fish samples. A good linear relationship between the actual concentration and predicted concentration of analytes based on PLSR models with R 2 values from 0.87 to 0.99 were obtained, indicating satisfactory quantification results of this method. These results demonstrate that the SERS method coupled with AuNR substrates can be used for rapid and accurate detection of MG and CV in fish samples. © 2017 Institute of Food Technologists®.

Eragrostis plana Nees as a novel eco-friendly adsorbent for removal of crystal violet from aqueous solutions.

PubMed

Filho, Augusto Cezar D; Mazzocato, Ana C; Dotto, Guilherme L; Thue, Pascal S; Pavan, Flávio A

2017-08-01

Eragrostis plana Nees (EPN) was used as new and eco-friendly adsorbent for the removal of crystal violet dye (CV) from aqueous solution. Specific surface area (BET), scanning electron microscopy (SEM), infrared spectroscopy (ATR-FTIR), point of zero charge (pH PZC ), and modified Boehm titration method were used to characterize the EPN material. The effects of initial pH of solution, adsorbent mass, contact time and initial dye concentration, and temperature were studied in batch adsorption mode. Kinetic data were evaluated by pseudo-first-order and pseudo-second-order models. The result exhibited that pseudo-second-order model well described the adsorption kinetics of CV onto EPN. Langmuir, Freundlich, and Sips isotherm models were used for analysis of the isothermal data. The equilibrium data of adsorption of CV onto EPN was better fitted with the Sips isotherm. Based on the Sips isotherm model, the maximum adsorption capacity was 76.20 ± 1.20 mg g -1 at 333 K. A high desorption of CV from EPN was obtained using 1.00 mol L -1 of CH 3 COOH as eluent. The thermodynamic data indicated that the adsorption was spontaneous, endothermic, and physical process. EPN can be used as alternative adsorbent to remove CV from aqueous solution.

Enhancing the Antibacterial Activity of Light-Activated Surfaces Containing Crystal Violet and ZnO Nanoparticles: Investigation of Nanoparticle Size, Capping Ligand, and Dopants.

PubMed

Sehmi, Sandeep K; Noimark, Sacha; Pike, Sebastian D; Bear, Joseph C; Peveler, William J; Williams, Charlotte K; Shaffer, Milo S P; Allan, Elaine; Parkin, Ivan P; MacRobert, Alexander J

2016-09-30

Healthcare-associated infections pose a serious risk for patients, staff, and visitors and are a severe burden on the National Health Service, costing at least £1 billion annually. Antimicrobial surfaces significantly contribute toward reducing the incidence of infections as they prevent bacterial adhesion and cause bacterial cell death. Using a simple, easily upscalable swell-encapsulation-shrink method, novel antimicrobial surfaces have been developed by incorporating metal oxide nanoparticles (NPs) and crystal violet (CV) dye into medical-grade polyurethane sheets. This study compares the bactericidal effects of polyurethane incorporating ZnO, Mg-doped ZnO, and MgO. All metal oxide NPs are well defined, with average diameters ranging from 2 to 18 nm. These materials demonstrate potent bactericidal activity when tested against clinically relevant bacteria such as Escherichia coli and Staphylococcus aureus . Additionally, these composites are tested against an epidemic strain of methicillin-resistant Staphylococcus aureus (MRSA) that is rife in hospitals throughout the UK. Furthermore, we have tested these materials using a low light intensity (∼500 lx), similar to that present in many clinical environments. The highest activity is achieved from polymer composites incorporating CV and ∼3 nm ZnO NPs, and the different performances of the metal oxides have been discussed.

A new rapid colourimetric method for testing Mycobacterium tuberculosis susceptibility to isoniazid and rifampicin: a crystal violet decolourisation assay.

PubMed

Coban, Ahmet Yilmaz

2014-04-01

The aim of this study was to investigate the performance of a new and accurate method for the detection of isoniazid (INH) and rifampicin (RIF) resistance among Mycobacterium tuberculosis isolates using a crystal violet decolourisation assay (CVDA). Fifty-five M. tuberculosis isolates obtained from culture stocks stored at -80ºC were tested. After bacterial inoculation, the samples were incubated at 37ºC for seven days and 100 µL of CV (25 mg/L stock solution) was then added to the control and sample tubes. The tubes were incubated for an additional 24-48 h. CV (blue/purple) was decolourised in the presence of bacterial growth; thus, if CV lost its colour in a sample containing a drug, the tested isolate was reported as resistant. The sensitivity, specificity, positive predictive value, negative predictive value and agreement for INH were 92.5%, 96.4%, 96.1%, 93.1% and 94.5%, respectively, and 88.8%, 100%, 100%, 94.8% and 96.3%, respectively, for RIF. The results were obtained within eight-nine days. This study shows that CVDA is an effective method to detect M. tuberculosis resistance to INH and RIF in developing countries. This method is rapid, simple and inexpensive. Nonetheless, further studies are necessary before routine laboratory implementation.

Determination of polyhexamethylene biguanide hydrochloride using photometric colloidal titration with crystal violet as a color indicator.

PubMed

Masadome, Takashi; Miyanishi, Takaaki; Watanabe, Keita; Ueda, Hiroshi; Hattori, Toshiaki

2011-01-01

A solution of polyhexamethylene biguanide hydrochloride (PHMB-HCl) was titrated with a standard solution of potassium poly(vinyl sulfate) (PVSK) using crystal violet (CV) as an photometric indicator cation. The end point was detected by a sharp absorbance change due to an abrupt decrease in the concentration of CV. A linear relationship between the concentration of PHMB-HCl and the end-point volume of the titrant existed in the concentration range from 2 to 10 × 10(-6) eq mol L(-1). Back-titration was based on adding an excess amount of PVSK to a sample solution containing CV, which was titrated with a standard solution of poly(diallyldimethylammonium chloride) (PDADMAC). The calibration curve of the PHMB-HCl concentration to the end point volume of the titrant was also linear in the concentration range from 2 to 8 × 10(-6) eq mol L(-1). Both photometric titrations were applied to the determination of PHMB-HCl in a few contact-lens detergents. Back-titration showed a clear end point, but direct titration showed an unclear end point. The results of the back-titration of PHMB-HCl were compared with the content registered in its labels. 2011 © The Japan Society for Analytical Chemistry

Enhancing the Antibacterial Activity of Light-Activated Surfaces Containing Crystal Violet and ZnO Nanoparticles: Investigation of Nanoparticle Size, Capping Ligand, and Dopants

PubMed Central

2016-01-01

Healthcare-associated infections pose a serious risk for patients, staff, and visitors and are a severe burden on the National Health Service, costing at least £1 billion annually. Antimicrobial surfaces significantly contribute toward reducing the incidence of infections as they prevent bacterial adhesion and cause bacterial cell death. Using a simple, easily upscalable swell–encapsulation–shrink method, novel antimicrobial surfaces have been developed by incorporating metal oxide nanoparticles (NPs) and crystal violet (CV) dye into medical-grade polyurethane sheets. This study compares the bactericidal effects of polyurethane incorporating ZnO, Mg-doped ZnO, and MgO. All metal oxide NPs are well defined, with average diameters ranging from 2 to 18 nm. These materials demonstrate potent bactericidal activity when tested against clinically relevant bacteria such as Escherichia coli and Staphylococcus aureus. Additionally, these composites are tested against an epidemic strain of methicillin-resistant Staphylococcus aureus (MRSA) that is rife in hospitals throughout the UK. Furthermore, we have tested these materials using a low light intensity (∼500 lx), similar to that present in many clinical environments. The highest activity is achieved from polymer composites incorporating CV and ∼3 nm ZnO NPs, and the different performances of the metal oxides have been discussed. PMID:27840856

Hypoxia Enhances the Antiglioma Cytotoxicity of B10, a Glycosylated Derivative of Betulinic Acid

PubMed Central

Thiepold, Anna-Luisa; Harter, Patrick N.; Reichert, Sebastian; Kögel, Donat; Paschke, Reinhard; Mittelbronn, Michel; Weller, Michael; Steinbach, Joachim P.; Fulda, Simone; Bähr, Oliver

2014-01-01

B10 is a glycosylated derivative of betulinic acid with promising activity against glioma cells. Lysosomal cell death pathways appear to be essential for its cytotoxicity. We investigated the influence of hypoxia, nutrient deprivation and current standard therapies on B10 cytotoxicity. The human glioma cell lines LN-308 and LNT-229 were exposed to B10 alone or together with irradiation, temozolomide, nutrient deprivation or hypoxia. Cell growth and viability were evaluated by crystal violet staining, clonogenicity assays, propidium iodide uptake and LDH release assays. Cell death was examined using an inhibitor of lysosomal acidification (bafilomycin A1), a cathepsin inhibitor (CA074-Me) and a short-hairpin RNA targeting cathepsin B. Hypoxia substantially enhanced B10-induced cell death. This effect was sensitive to bafilomycin A1 and thus dependent on hypoxia-induced lysosomal acidification. Cathepsin B appeared to mediate cell death because either the inhibitor CA074-Me or cathepsin B gene silencing rescued glioma cells from B10 toxicity under hypoxia. B10 is a novel antitumor agent with substantially enhanced cytotoxicity under hypoxia conferred by increased lysosomal cell death pathway activation. Given the importance of hypoxia for therapy resistance, malignant progression, and as a result of antiangiogenic therapies, B10 might be a promising strategy for hypoxic tumors like malignant glioma. PMID:24743710

A High-Throughput Screening Platform of Microbial Natural Products for the Discovery of Molecules with Antibiofilm Properties against Salmonella

PubMed Central

Paytubi, Sonia; de La Cruz, Mercedes; Tormo, Jose R.; Martín, Jesús; González, Ignacio; González-Menendez, Victor; Genilloud, Olga; Reyes, Fernando; Vicente, Francisca; Madrid, Cristina; Balsalobre, Carlos

2017-01-01

In this report, we describe a High-Throughput Screening (HTS) to identify compounds that inhibit biofilm formation or cause the disintegration of an already formed biofilm using the Salmonella Enteritidis 3934 strain. Initially, we developed a new methodology for growing Salmonella biofilms suitable for HTS platforms. The biomass associated with biofilm at the solid-liquid interface was quantified by staining both with resazurin and crystal violet, to detect living cells and total biofilm mass, respectively. For a pilot project, a subset of 1120 extracts from the Fundación MEDINA's collection was examined to identify molecules with antibiofilm activity. This is the first validated HTS assay of microbial natural product extracts which allows for the detection of four types of activities which are not mutually exclusive: inhibition of biofilm formation, detachment of the preformed biofilm and antimicrobial activity against planktonic cells or biofilm embedded cells. Currently, several extracts have been selected for further fractionation and purification of the active compounds. In one of the natural extracts patulin has been identified as a potent molecule with antimicrobial activity against both, planktonic cells and cells within the biofilm. These findings provide a proof of concept that the developed HTS can lead to the discovery of new natural compounds with antibiofilm activity against Salmonella and its possible use as an alternative to antimicrobial therapies and traditional disinfectants. PMID:28303128

Preliminary Studies of the Immunomodulator Effect of the Bougainvillea xbuttiana Extract in a Mouse Model

PubMed Central

Arteaga Figueroa, Lluvia; Barbosa Navarro, Leticia; Patiño Vera, Martin; Petricevich, Vera L.

2015-01-01

Bougainvillea xbuttiana is used as an analgesic in folk medicine in Mexico. The purpose of the present study was to determine the effects of the ethanolic extract from B. xbuttiana on macrophages activities. The phytochemical screening was performed for determine the presence of alkaloids, flavonoids, triterpenes, and saponins. The effects of B. xbuttiana were analyzed using the macrophages activities as determined by the H2O2 release, spreading and phagocytic index, vacuoles formation percentage, and mediators production. The viability percentage was determined in live cells after fixing and staining with crystal violet. The presence of H2O2 in macrophages was performed by using the peroxidase-phenol red solution. The cytokine production was determined by two assays, ELISA for detection of IL-6, IL-10, and IFN-γ and biological assay for TNF detection. The results showed that the Bxb extract dose-dependent manner produces (a) an increase in levels of H2O2 and spreading and vacuoles formation percentages, (b) a decrease in phagocytic index and in the amounts of TNF, IL-6, and IFN-γ, and (c) an increase significant in IL-10 and NO production. This study indicates that the ethanolic extract from Bougainvillea xbuttiana was able to activate macrophages. The combination of these results suggests that this extract has an immunomodulator effect. PMID:25861362

Effects of extracts from Italian medicinal plants on planktonic growth, biofilm formation and adherence of methicillin-resistant Staphylococcus aureus

PubMed Central

Quave, Cassandra L.; Plano, Lisa R.W.; Pantuso, Traci; Bennett, Bradley C.

2008-01-01

One-third of botanical remedies from southern Italy are used to treat skin and soft tissue infection (SSTI). Staphylococcus aureus, a common cause of SSTI, has generated increasing concern due to drug resistance. Many plants possess antimicrobial agents and provide effective remedies for SSTI. Our aim was to investigate plants from different ethnobotanical usage groups for inhibition of growth and biofilms in methicillin-resistant S. aureus (MRSA). Three groups were assessed: plant remedies for SSTI, plant remedies not involving the skin, and plants with no ethnomedical application. We screened 168 extracts, representing 104 botanical species, for activity against MRSA (ATCC 33593). We employed broth dilution methods to determine the MIC after 18 hours growth using an optical density (OD600nm) reading. Anti-biofilm effects were assessed by growing biofilms for 40 hours, then fixing and staining with crystal violet. After washing, 10% Tween 80 was added and OD570nm readings were taken. Extracts from 10 plants exhibited an IC50 ≤32 μg/ml for biofilm inhibition: Lonicera alpigena, Castanea sativa, Juglans regia, Ballota nigra, Rosmarinus officinalis, Leopoldia comosa, Malva sylvestris, Cyclamen hederifolium, Rosa canina, and Rubus ulmifolius. Limited bacteriostatic activity was evident. The anti-biofilm activity of medicinal plants was significantly greater than plants without any ethnomedical applications. PMID:18556162

Utilizing hydrogen sulfide as a novel anti-cancer agent by targeting cancer glycolysis and pH imbalance

PubMed Central

Lee, Z-W; Teo, X-Y; Tay, E Y-W; Tan, C-H; Hagen, T; Moore, P K; Deng, L-W

2014-01-01

Background and Purpose Many disparate studies have reported the ambiguous role of hydrogen sulfide (H2S) in cell survival. The present study investigated the effect of H2S on the viability of cancer and non-cancer cells. Experimental Approach Cancer and non-cancer cells were exposed to H2S [using sodium hydrosulfide (NaHS) and GYY4137] and cell viability was examined by crystal violet assay. We then examined cancer cellular glycolysis by in vitro enzymatic assays and pH regulator activity. Lastly, intracellular pH (pHi) was determined by ratiometric pHi measurement using BCECF staining. Key Results Continuous, but not a single, exposure to H2S decreased cell survival more effectively in cancer cells, as compared to non-cancer cells. Slow H2S-releasing donor, GYY4137, significantly increased glycolysis, leading to overproduction of lactate. H2S also decreased anion exchanger and sodium/proton exchanger activity. The combination of increased metabolic acid production and defective pH regulation resulted in an uncontrolled intracellular acidification, leading to cancer cell death. In contrast, no significant intracellular acidification or cell death was observed in non-cancer cells. Conclusions and Implications Low and continuous exposure to H2S targets metabolic processes and pH homeostasis in cancer cells, potentially serving as a novel and selective anti-cancer strategy. PMID:24827113

Angiogenic effects of apigenin on endothelial cells after hypoxia-reoxygenation via the caveolin-1 pathway

PubMed Central

Tu, Fengxia; Pang, Qiongyi; Chen, Xiang; Huang, Tingting; Liu, Meixia; Zhai, Qiongxiang

2017-01-01

In the present study, we aimed to elucidate whether apigenin contributes to the induction of angiogenesis and the related mechanisms in cell hypoxia-reoxygenation injury. The role of apigenin was examined in human umbilical vein endothelial cell (HUVEC) viability, migration and tube formation in vitro. To investigate the related mechanisms, we used caveolin-1 short interfering RNA. The viability of HUVECs was measured using Cell Counting Kit-8 assays, HUVEC migration was analyzed by crystal violet staining, and a tube formation assay was performed using the branch point method. Expression of caveolin-1, vascular endothelial growth factor (VEGF), and endothelial nitric oxide synthase (eNOS) in HUVECs was examined by polymerase chain reaction and western blotting. Our data revealed that apigenin induced angiogenesis in vitro by increasing the tube formation ability of HUVECs, which was counteracted by caveolin-1 silencing. Compared to the NC group, Caveolin-1 and eNOS expression was upregulated by apigenin, whereas compared to the NC group, eNOS expression was increased upon caveolin-1 silencing. The expression of VEGF was increased by treatment with apigenin; however, compared to the NC group, caveolin-1 silencing did not affect VEGF expression, and apigenin did not increase VEGF expression in HUVECs after caveolin-1 silencing. These data suggest that apigenin may be a candidate therapeutic target for stroke recovery by promoting angiogenesis via the caveolin-1 signaling pathway. PMID:29039442

Inhibition of quorum-sensing-mediated biofilm formation in Cronobacter sakazakii strains.

PubMed

Singh, Niharika; Patil, Amrita; Prabhune, Asmita; Goel, Gunjan

2016-09-01

The present study investigated plant extracts for their anti-quorum-sensing (QS) potential to inhibit the biofilm formation in Cronobacter sakazakii strains. The bioassay based on loss of pigment production by Chromobacterium violaceum 026 and Agrobacterium tumefaciens NTL4(pZLR4) was used for initial screening of the extracts. Further, the effect of extracts on the inhibition of QS-mediated biofilm in C. sakazakii isolates was evaluated using standard crystal violet assay. The effect on biofilm texture was studied using SYTO9 staining and light and scanning electron microscopy. Among the tested extracts, Piper nigrum and Cinnamomum verum at 100 ppm resulted in 78 and 68 % reduction in the production of violacein as well as blue-green colour in both biosensor strains. A higher inhibitory activity (>50 %) on biofilm formation in C. sakazakii was observed for Pip. nigrum and Cin. verum, whereas the other extracts possessed moderate (25-50 %) and minimal (<25 %) inhibitory activities. Further, the fluorescent and scanning electron microscopic images indicated a major disruption in the architecture of biofilms of tested strains by Pip. nigrum. This study points to the possibility of using Pip. nigrum and Cin. verum as inhibitor of QS-mediated biofilm formation by C. sakazakii that could be further explored for novel bioactive molecules to limit the emerging infections of C. sakazakii.

A new approach to study attached biofilms and floating communities from Pseudomonas aeruginosa strains of various origins reveals diverse effects of divalent ions.

PubMed

Gagné-Thivierge, Cynthia; Barbeau, Jean; Levesque, Roger C; Charette, Steve J

2018-06-25

Pseudomonas aeruginosa is an opportunistic pathogen associated with nosocomial infections and disease complications. In the lungs of cystic fibrosis (CF) individuals, biofilm growth plays a crucial role in the persistence and antibiotic resistance of P. aeruginosa. Some strains, adapted to the CF lung microenvironment, show distinguishable phenotypes linked to biofilm production when compared to other strains. Using a novel image analysis quantification approach with crystal violet-stained biofilms, we compared the biofilm formation of four different P. aeruginosa isolates in 24-well plates: PAO1, the reference strain, LESB58 from CF patients' lungs, and PPF-1 and Urg-7, two environmental isolates from dental unit waterlines. We also observed the formation of biofilm-like structures (BLSs) floating in the medium and investigated growth inhibition of the attached biofilm and BLS with Mg2+ or Zn2+. Urg-7 produced the most attached biofilms, but not the most BLSs. Attached biofilms had different responses to cations than BLSs did, but the effect of the cations was similar for all strains. These results demonstrate some diversity of biofilm formation in P. aeruginosa and indicate that chemical inhibition of attached biofilm formation for a specific strain or isolate cannot be predicative of a result on other P. aeruginosa strains or on BLSs.

Inhibition of Staphylococcus epidermidis Biofilm Formation by Traditional Thai Herbal Recipes Used for Wound Treatment.

PubMed

Chusri, S; Sompetch, K; Mukdee, S; Jansrisewangwong, S; Srichai, T; Maneenoon, K; Limsuwan, S; Voravuthikunchai, S P

2012-01-01

Development of biofilm is a key mechanism involved in Staphylococcus epidermidis virulence during device-associated infections. We aimed to investigate antibiofilm formation and mature biofilm eradication ability of ethanol and water extracts of Thai traditional herbal recipes including THR-SK004, THR-SK010, and THR-SK011 against S. epidermidis. A biofilm forming reference strain, S. epidermidis ATCC 35984 was employed as a model for searching anti-biofilm agents by MTT reduction assay. The results revealed that the ethanol extract of THR-SK004 (THR-SK004E) could inhibit the formation of S. epidermidis biofilm on polystyrene surfaces. Furthermore, treatments with the extract efficiently inhibit the biofilm formation of the pathogen on glass surfaces determined by scanning electron microscopy and crystal violet staining. In addition, THR-SK010 ethanol extract (THR-SK010E; 0.63-5 μg/mL) could decrease 30 to 40% of the biofilm development. Almost 90% of a 7-day-old staphylococcal biofilm was destroyed after treatment with THR-SK004E (250 and 500 μg/mL) and THR-SK010E (10 and 20 μg/mL) for 24 h. Therefore, our results clearly demonstrated THR-SK004E could prevent the staphylococcal biofilm development, whereas both THR-SK004E and THR-SK010E possessed remarkable eradication ability on the mature staphylococcal biofilm.

Passive control of quorum sensing: prevention of Pseudomonas aeruginosa biofilm formation by imprinted polymers.

PubMed

Piletska, Elena V; Stavroulakis, Georgios; Larcombe, Lee D; Whitcombe, Michael J; Sharma, Anant; Primrose, Sandy; Robinson, Gary K; Piletsky, Sergey A

2011-04-11

Here we present the first molecular imprinted polymer (MIP) that is able to attenuate the biofilm formation of the opportunistic human pathogen Pseudomonas aeruginosa through specific sequestration of its signal molecule N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C(12)-AHL). The MIP was rationally designed using computational modeling, and its capacity and specificity and that of a corresponding blank polymer toward signal molecule of P. aeruginosa (3-oxo-C(12)-AHL) and its analogue were tested. The biofilm formation in the presence of polymers and without polymers was studied using scanning confocal laser microscopy. Staining with crystal violet dye was used for the quantification of the biofilm formation. A significant reduction of the biofilm growth was observed in the presence of MIP (>80%), which was superior to that of the resin prepared without template, which showed a reduction of 40% in comparison with biofilm, which was grown without polymer addition. It was shown that 3-oxo-C(12)-AHL-specific MIP prevented the development of quorum-sensing-controlled phenotypes (in this case, biofilm formation) from being up-regulated. The developed MIP could be considered as a new tool for the elimination of life-threatening infections in a multitude of practical applications; it could, for example, be grafted on the surface of medical devices such as catheters and lenses, be a component of paints, or be used as a wound adsorbent.

Homology modeling and virtual screening to discover potent inhibitors targeting the imidazole glycerophosphate dehydratase protein in Staphylococcus xylosus

NASA Astrophysics Data System (ADS)

Chen, Xing-Ru; Wang, Xiao-Ting; Hao, Mei-Qi; Zhou, Yong-Hui; Cui, Wen-Qiang; Xing, Xiao-Xu; Xu, Chang-Geng; Bai, Jing-Wen; Li, Yan-Hua

2017-11-01

The imidazole glycerophosphate dehydratase (IGPD) protein is a therapeutic target for herbicide discovery. It is also regarded as a possible target in Staphylococcus xylosus (S. xylosus) for solving mastitis in the dairy cow. The 3D structure of IGPD protein is essential for discovering novel inhibitors during high-throughput virtual screening. However, to date, the 3D structure of IGPD protein of S. xylosus has not been solved. In this study, a series of computational techniques including homology modeling, Ramachandran Plots, and Verify 3D were performed in order to construct an appropriate 3D model of IGPD protein of S. xylosus. Nine hits were identified from 2500 compounds by docking studies. Then, these 9 compounds were first tested in vitro in S. xylosus biofilm formation using crystal violet staining. One of the potential compounds, baicalin was shown to significantly inhibit S. xylosus biofilm formation. Finally, the baicalin was further evaluated, which showed better inhibition of biofilm formation capability in S. xylosus by scanning electron microscopy. Hence, we have predicted the structure of IGPD protein of S. xylosus using computational techniques. We further discovered the IGPD protein was targeted by baicalin compound which inhibited the biofilm formation in S. xylosus. Our findings here would provide implications for the further development of novel IGPD inhibitors for the treatment of dairy mastitis.

Effect of γ-lactones and γ-lactams compounds on Streptococcus mutans biofilms

PubMed Central

Sordi, Mariane Beatriz; Moreira, Thaís Altoé; Montero, Juan Felipe Dumes; Barbosa, Luis Cláudio; Benfatti, César Augusto Magalhães; Magini, Ricardo de Souza; Pimenta, Andréa de Lima

2018-01-01

Abstract Considering oral diseases, antibiofilm compounds can decrease the accumulation of pathogenic species such as Streptococcus mutans at micro-areas of teeth, dental restorations or implant-supported prostheses. Objective To assess the effect of thirteen different novel lactam-based compounds on the inhibition of S. mutans biofilm formation. Material and methods We synthesized compounds based on γ-lactones analogues from rubrolides by a mucochloric acid process and converted them into their corresponding γ-hydroxy-γ-lactams by a reaction with isobutylamine and propylamine. Compounds concentrations ranging from 0.17 up to 87.5 μg mL-1 were tested against S. mutans. We diluted the exponential cultures in TSB and incubated them (37°C) in the presence of different γ-lactones or γ-lactams dilutions. Afterwards, we measured the planktonic growth by optical density at 630 nm and therefore assessed the biofilm density by the crystal violet staining method. Results Twelve compounds were active against biofilm formation, showing no effect on bacterial viability. Only one compound was inactive against both planktonic and biofilm growth. The highest biofilm inhibition (inhibition rate above 60%) was obtained for two compounds while three other compounds revealed an inhibition rate above 40%. Conclusions Twelve of the thirteen compounds revealed effective inhibition of S. mutans biofilm formation, with eight of them showing a specific antibiofilm effect. PMID:29489934

Homology Modeling and Virtual Screening to Discover Potent Inhibitors Targeting the Imidazole Glycerophosphate Dehydratase Protein in Staphylococcus xylosus.

PubMed

Chen, Xing-Ru; Wang, Xiao-Ting; Hao, Mei-Qi; Zhou, Yong-Hui; Cui, Wen-Qiang; Xing, Xiao-Xu; Xu, Chang-Geng; Bai, Jing-Wen; Li, Yan-Hua

2017-01-01

The imidazole glycerophosphate dehydratase (IGPD) protein is a therapeutic target for herbicide discovery. It is also regarded as a possible target in Staphylococcus xylosus ( S. xylosus ) for solving mastitis in the dairy cow. The 3D structure of IGPD protein is essential for discovering novel inhibitors during high-throughput virtual screening. However, to date, the 3D structure of IGPD protein of S. xylosus has not been solved. In this study, a series of computational techniques including homology modeling, Ramachandran Plots, and Verify 3D were performed in order to construct an appropriate 3D model of IGPD protein of S. xylosus . Nine hits were identified from 2,500 compounds by docking studies. Then, these nine compounds were first tested in vitro in S. xylosus biofilm formation using crystal violet staining. One of the potential compounds, baicalin was shown to significantly inhibit S. xylosus biofilm formation. Finally, the baicalin was further evaluated, which showed better inhibition of biofilm formation capability in S. xylosus by scanning electron microscopy. Hence, we have predicted the structure of IGPD protein of S. xylosus using computational techniques. We further discovered the IGPD protein was targeted by baicalin compound which inhibited the biofilm formation in S. xylosus . Our findings here would provide implications for the further development of novel IGPD inhibitors for the treatment of dairy mastitis.

Overview of electron crystallography of membrane proteins: crystallization and screening strategies using negative stain electron microscopy.

PubMed

Nannenga, Brent L; Iadanza, Matthew G; Vollmar, Breanna S; Gonen, Tamir

2013-01-01

Electron cryomicroscopy, or cryoEM, is an emerging technique for studying the three-dimensional structures of proteins and large macromolecular machines. Electron crystallography is a branch of cryoEM in which structures of proteins can be studied at resolutions that rival those achieved by X-ray crystallography. Electron crystallography employs two-dimensional crystals of a membrane protein embedded within a lipid bilayer. The key to a successful electron crystallographic experiment is the crystallization, or reconstitution, of the protein of interest. This unit describes ways in which protein can be expressed, purified, and reconstituted into well-ordered two-dimensional crystals. A protocol is also provided for negative stain electron microscopy as a tool for screening crystallization trials. When large and well-ordered crystals are obtained, the structures of both protein and its surrounding membrane can be determined to atomic resolution.

Evaluation of different methods to detect microbial hygiene indicators relevant in the dairy industry.

PubMed

Hervert, C J; Alles, A S; Martin, N H; Boor, K J; Wiedmann, M

2016-09-01

It is estimated that 19% of the total food loss from retail, food service, and households comes from dairy products. A portion of this loss may be attributed to premature spoilage of products due to lapses in sanitation and postpasteurization contamination at the processing level. Bacterial groups including coliforms, Enterobacteriaceae (EB), and total gram-negative organisms represent indicators of poor sanitation or postpasteurization contamination in dairy products worldwide. Although Petrifilms (3M, St. Paul, MN) and traditional selective media are commonly used for the testing of these indicator organism groups throughout the US dairy industry, new rapid methods are also being developed. This project was designed to evaluate the ability of different methods to detect coliforms, EB, and other gram-negative organisms isolated from various dairy products and dairy processing environments. Using the Food Microbe Tracker database, a collection of 211 coliform, EB, and gram-negative bacterial isolates representing 25 genera associated with dairy products was assembled for this study. We tested the selected isolates in pure culture (at levels of approximately 15 to 300 cells/test) to evaluate the ability of 3M Coliform Petrifilm to detect coliforms, 3M Enterobacteriaceae Petrifilm, violet red bile glucose agar, and an alternative flow cytometry-based method (bioMérieux D-Count, Marcy-l'Étoile, France) to detect EB, and crystal violet tetrazolium agar to detect total gram-negative organisms. Of the 211 gram-negative isolates tested, 82% (174/211) had characteristic growth on crystal violet tetrazolium agar. Within this set of 211 gram-negative organisms, 175 isolates representing 19 EB genera were screened for detection using EB selective/differential testing methods. We observed positive results for 96% (168/175), 90% (158/175), and 86% (151/175) of EB isolates when tested on EB Petrifilm, violet red bile glucose agar, and D-Count, respectively; optimization of the cut-off thresholds for the D-Count may further improve its sensitivity and specificity, but will require additional data and may vary in food matrices. Additionally, 74% (129/175) of the EB isolates tested positive as coliforms. The data obtained from this study identify differences in detection between 5 microbial hygiene indicator tests and highlight the benefits of EB and total gram-negative testing methods. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Influence of VO2+ ions on structural and optical properties of potassium succinate-succinic acid single crystal for non-linear optical applications

NASA Astrophysics Data System (ADS)

Juliet sheela, K.; Subramanian, P.

2018-04-01

A transparent and good optical quality semi organic single crystal of vanadium doped potassium succinate-succinic acid (KSSA) was synthesized by slow evaporation technique at room temperature. The structural perfection was supported by the powder XRD of the KSSA-VO2+ single crystal. Optical behavior of the material was discovered from the absorption and transmission spectra of UV-vis-NIR characterization. Functional group and presence of metal ion in the specimen are depicted from FTIR traces. From the photoluminescence studies, emission of wavelength in the violet region (418 nm) at the excitation of 243 nm could be ascertained. EDAX, SEM measurements identify presence of elements and pictures the step-line growth and the imperfection presents in the grown crystal. EPR analysis extracts the information about the local site symmetry around the impurity ion, molecular orbital coefficients, admixture coefficients and ground state wave function of VO2+ doped KSSA single crystal. Second harmonic generation (SHG) efficiency of the grown crystal was investigated to explore the NLO characteristic of the material.

Growth and characterization of a new nonlinear optical organic crystal: 2,4,6-Trimethylacetanilide

NASA Astrophysics Data System (ADS)

Upadhyaya, V.; Prabhu, Sharada G.

2015-09-01

A new nonlinear optical organic material, 2,4,6-trimethylacetanilide (246TMAA), also known as N-[2,4,6- trimethylphenyl]acetamide, has been synthesized and grown as a single crystal by the slow evaporation technique by organic solvents. The grown crystals have been characterized by morphology study. The crystals are prismatic. Surface examination shows granular dendritic pattern in optical micrograph. The Scanning Electron Micrograph shows the layered growth of the crystal. The Differential Scanning Calorimeter plot shows no phase change until melting point (219°C). The density of the crystals is 1.1g/cc and the crystals are soft. The crystals are transparent in the visible region and in the ultra-violet region till 280 nm. 246TMAA crystallizes with 2 molecules in a monoclinic unit cell in the noncentrosymmetric point group m, space group Pn. Refractive indices of this optically biaxial crystal along the three crystallophysical axes have been measured at 633 nm. The optical second harmonic generation efficiency of the crystal at 1064 nm is about half that of the urea crystal, measured by powder method using Nd:YAG laser. The results show that the 246TMAA crystal can efficiently be used for up-conversion of infrared radiation into visible green light. The powder X-ray diffraction spectrum of the crystal has been obtained.

Autophagic Cell Death, Polyploidy and Senescence Induced in Breast Tumor Cells by the Substituted Pyrrole JG-03-14, a Novel Microtubule Poison

PubMed Central

Arthur, Christopher R.; Gupton, John T.; Kellogg, Glen E.; Yeudall, W. Andrew; Cabot, Myles C.; Newsham, Irene; Gewirtz, David A.

2007-01-01

JG-03-14, a substituted pyrrole that inhibits microtubule polymerization, was screened against MCF-7 (p53 wild type), MDA-MB 231 (p53 mutant), MCF-7/caspase 3 and MCF-7/ADR (multidrug resistant) breast tumor cell lines. Cell viability and growth inhibition were assessed by the crystal violet dye assay. Apoptosis was evaluated by the TUNEL assay, cell cycle distribution by flow cytometry, autophagy by acridine orange staining of vesicle formation, and senescence based on β-galactosidase staining and cell morphology. Our studies indicate that exposure to JG-03-14, at a concentration of 500 nM, induces time dependent cell death in the MCF-7 and MDA-MB 231 cell lines. In MCF-7 cells, a residual surviving cell population was found to be senescent; in contrast, there was no surviving senescent population in treated MDA-MB 231 cells. No proliferative recovery was detected over a period of 15 days post-treatment in either cell line. Both the TUNEL assay and FLOW cytometry indicated a relatively limited degree of apoptosis (< 10%) in response to drug treatment in MCF-7 cells with more extensive apoptosis (but < 20%) in MDA-MB231 cells; acidic vacuole formation indicative of autophagic cell death was relatively extensive in both MCF-7 and MDA-MB231 cells. In addition, JG-03-14 induced the formation of a large hyperdiploid cell population in MDA-MB231 cells. JG-03-14 also demonstrated pronounced anti-proliferative activity in MCF-7/caspase 3 cells and in the MCF-7/ADR cell line. The observation that JG-03-14 promotes autophagic cell death and also retains activity in tumor cells expressing the multidrug resistance pump indicates that novel microtubule poisons of the substituted pyrroles class may hold promise in the treatment of breast cancer. PMID:17692290

Unsaturated fatty acid, cis-2-decenoic acid, in combination with disinfectants or antibiotics removes pre-established biofilms formed by food-related bacteria.

PubMed

Sepehr, Shayesteh; Rahmani-Badi, Azadeh; Babaie-Naiej, Hamta; Soudi, Mohammad Reza

2014-01-01

Biofilm formation by food-related bacteria and food-related pathogenesis are significant problems in the food industry. Even though much disinfection and mechanical procedure exist for removal of biofilms, they may fail to eliminate pre-established biofilms. cis-2 decenoic acid (CDA), an unsaturated fatty acid messenger produced by Pseudomonas aeruginosa, is reportedly capable of inducing the dispersion of established biofilms by multiple types of microorganisms. However, whether CDA has potential to boost the actions of certain antimicrobials is unknown. Here, the activity of CDA as an inducer of pre-established biofilms dispersal, formed by four main food pathogens; Staphylococcus aureus, Bacillus cereus, Salmonella enterica and E. coli, was measured using both semi-batch and continuous cultures bioassays. To assess the ability of CDA combined biocides treatments to remove pre-established biofilms formed on stainless steel discs, CFU counts were performed for both treated and untreated cultures. Eradication of the biofilms by CDA combined antibiotics was evaluated using crystal violet staining. The effect of CDA combined treatments (antibiotics and disinfectants) on biofilm surface area and bacteria viability was evaluated using fluorescence microscopy, digital image analysis and LIVE/DEAD staining. MICs were also determined to assess the probable inhibitory effects of CDA combined treatments on the growth of tested microorganisms' planktonic cells. Treatment of pre-established biofilms with only 310 nM CDA resulted in at least two-fold increase in the number of planktonic cells in all cultures. While antibiotics or disinfectants alone exerted a trivial effect on CFU counts and percentage of surface area covered by the biofilms, combinational treatments with both 310 nM CDA and antibiotics or disinfectants led to approximate 80% reduction in biofilm biomass. These data suggests that combined treatments with CDA would pave the way toward developing new strategies to control biofilms with widespread applications in industry as well as medicine.

Unsaturated Fatty Acid, cis-2-Decenoic Acid, in Combination with Disinfectants or Antibiotics Removes Pre-Established Biofilms Formed by Food-Related Bacteria

PubMed Central

Sepehr, Shayesteh; Rahmani-Badi, Azadeh; Babaie-Naiej, Hamta; Soudi, Mohammad Reza

2014-01-01

Biofilm formation by food-related bacteria and food-related pathogenesis are significant problems in the food industry. Even though much disinfection and mechanical procedure exist for removal of biofilms, they may fail to eliminate pre-established biofilms. cis-2 decenoic acid (CDA), an unsaturated fatty acid messenger produced by Pseudomonas aeruginosa, is reportedly capable of inducing the dispersion of established biofilms by multiple types of microorganisms. However, whether CDA has potential to boost the actions of certain antimicrobials is unknown. Here, the activity of CDA as an inducer of pre-established biofilms dispersal, formed by four main food pathogens; Staphylococcus aureus, Bacillus cereus, Salmonella enterica and E. coli, was measured using both semi-batch and continuous cultures bioassays. To assess the ability of CDA combined biocides treatments to remove pre-established biofilms formed on stainless steel discs, CFU counts were performed for both treated and untreated cultures. Eradication of the biofilms by CDA combined antibiotics was evaluated using crystal violet staining. The effect of CDA combined treatments (antibiotics and disinfectants) on biofilm surface area and bacteria viability was evaluated using fluorescence microscopy, digital image analysis and LIVE/DEAD staining. MICs were also determined to assess the probable inhibitory effects of CDA combined treatments on the growth of tested microorganisms' planktonic cells. Treatment of pre-established biofilms with only 310 nM CDA resulted in at least two-fold increase in the number of planktonic cells in all cultures. While antibiotics or disinfectants alone exerted a trivial effect on CFU counts and percentage of surface area covered by the biofilms, combinational treatments with both 310 nM CDA and antibiotics or disinfectants led to approximate 80% reduction in biofilm biomass. These data suggests that combined treatments with CDA would pave the way toward developing new strategies to control biofilms with widespread applications in industry as well as medicine. PMID:25000301

Biofilm Formation and Disinfectant Susceptibility of Persistent and Nonpersistent Listeria monocytogenes Isolates from Gorgonzola Cheese Processing Plants.

PubMed

Costa, Annalisa; Bertolotti, Luigi; Brito, Luisa; Civera, Tiziana

2016-11-01

The aim of this study was to investigate whether the biofilm-forming ability and/or the disinfectant susceptibility accounted for the persistence of Listeria monocytogenes in Gorgonzola cheese processing plants. For this purpose, a set of 16 L. monocytogenes isolates collected in the 2004-2007 period was analyzed, including 11 persistent isolates collected in different years, within the collection period, and displaying identical or highly correlated pulsotypes. The evaluation of biofilm-forming ability was assessed using crystal violet (CV) staining and the enumeration of viable cells on stainless steel coupons (SSC). Absorbance values obtained with CV staining for persistent and nonpersistent isolates were not significantly different (rm-ANOVA p > 0.05) and the cell counts from nonpersistent isolates showed to be higher compared with persistent isolates (rm-ANOVA p < 0.05). A simulation of disinfectant treatments was performed on spot inoculated coupons in clean and dirty conditions, according to EN 13697, and on biofilms on SSC, grown in nutrient-rich (dirty) and limiting (clean) conditions using acid acetic-hydrogen peroxide (P3) and acid citric-hydrogen peroxide (MS) commercial disinfectants. The treatment was considered effective when a 4 Log reduction in viable cell count was observed. The Log reductions of persistent and nonpersistent isolates, obtained with both the assays in clean and dirty conditions, were compared and no significant differences were detected (rm-ANOVA p > 0.05). A greater influence of organic matter on MS could explain why P3 was efficient in reducing to effective levels the majority of the isolates at the lowest concentration suggested by the manufacturer (0.2% [v/v]), while the same purpose required a higher concentration (1% [v/v]) of MS. In conclusion, our results demonstrate that the persistence of these isolates in Gorgonzola cheese processing plants was linked neither to the biofilm-forming ability nor to their susceptibility to hydrogen peroxide-based disinfectants; therefore, other factors should contribute to the persistent colonization of the dairies.

Virulence properties of multidrug resistant ocular isolates of Acinetobacter baumannii.

PubMed

Talreja, Deepa; Muraleedharan, Chithra; Gunathilaka, Gayathri; Zhang, Yifan; Kaye, Keith S; Walia, Satish K; Kumar, Ashok

2014-07-01

Acinetobacter (A.) baumannii is an opportunistic pathogen and has been reported as a causative agent of ocular infections. The aim of this study is to identify virulence properties (biofilm formation, adhesion, invasion and cytotoxicity) and antibiotic resistance among A. baumannii isolates recovered from the eye. The Microscan Walk-Away®, an automated bacterial identification and susceptibility testing system was used to determine antibiotic resistance. Clonal relatedness was assessed by Pulsed-field gel electrophoresis (PFGE) and plasmid profile analysis. Conjugation experiments were carried out to determine the transfer of antibiotic resistance genes and PCR was used to confirm gene transfer. Virulence properties of the isolates were determined by biofilm formation using crystal violet and immunofluorescence staining, adherence and internalization using cultured corneal epithelial cells, and cytotoxicity by TUNEL-staining and LDH release assays. All ocular isolates (n = 12) exhibited multidrug resistant (MDR) phenotype and one of the isolate (AB12) was resistant to 18 antibiotics (β-lactam, aminoglycosides, tetracycline, chloramphenicol and quinolones). The plasmid profile analysis showed the presence of multiple plasmids in each isolate and a total of 10 different profiles were observed. However, PFGE analysis was more discriminatory which revealed 12 distinct genotypes. Antibiotic resistance (tetracycline and quinolone) was transferable from the isolate AB12 to a recipient Escherichia coli J53. Ten isolates were strong biofilm producers and the remaining two (AB5 and AB7) were moderate producers. All isolates demonstrated adherence and invasive properties towards HCECs. A similar trend was observed in their ability to cause cell death and toxicity. Our results indicate that ocular isolates of A. baumannii are biofilm producers and adherent and invasive to corneal epithelium, a first step in the pathogenesis of ocular infection. In addition, they demonstrated plasmid-mediated transfer of MDR traits making them a reservoir of resistance genes at ocular surface.

[RITA combined with temozolomide inhibits the proliferation of human glioblastoma U87 cells].

PubMed

He, Xiao-Yan; Feng, Xiao-Li; Song, Xin-Pei; Zeng, Huan-Chao; Cao, Zhong-Xu; Xiao, Wei-Wei; Zhang, Bao; Wu, Qing-Hua

2016-10-20

To observe the effect of RITA, a small molecule that targets p53, combined with temozolomide (TMZ) on proliferation, colony formation and apoptosis of human glioblastoma U87 cells and explore the underlying mechanism. Cultured U87 cells were treated with RITA (1, 5, 10, 20 µmol/L), TMZ, or RITA+TMZ (half dose) for 24, 48 or 72 h. MTS assay were used to detect the cell proliferation, and the cell proliferation rate and inhibitory rate were calculated. The effect of combined treatments was evaluated by the q value. The expressions of p53, p21 and other apoptosis-associated genes were detected by qRT-PCR and Western blotting; cell apoptosis was assayed using flow cytometry with Annexin V/PI double staining; colony formation of the cells was detected with crystal violet staining. MTS assay showed that RITA at the 4 doses more potently inhibited U87 cell viability than TMZ at 72 h (P=0.000) with inhibitory rates of 25.94%-41.38% and 3.84%-8.20%, respectively. RITA combined with TMZ caused a more significant inhibition of U87 cells (29.21%-52.11%) than RITA (P<0.01) and TMZ (P=0.000) alone. At the doses above 5 µmol/L, the combined treatments with RITA+TMZ for 48 h resulted in q values exceeding 1.2 and showed an obvious synergistic effect of the drugs. Both RITA and TMZ, especially the latter, significantly increased the expressions of p53, p21, puma, and other apoptosis-associated genes to accelerate apoptosis and inhibit the growth and colony formation of U87 cells, and the effect was more obvious with a combined treatment. RITA inhibits the growth of human glioblastoma cells and enhance their sensitivity to TMZ by up-regulating p53 expression, and when combined, RITA and TMZ show a synergistic effect to cause a stronger cell inhibition.

Survey of the Antibiofilm and Antimicrobial Effects of Zingiber officinale (in Vitro Study)

PubMed Central

Aghazadeh, Marzieh; Zahedi Bialvaei, Abed; Aghazadeh, Mohammad; Kabiri, Fahimeh; Saliani, Negar; Yousefi, Mehdi; Eslami, Hosein; Samadi Kafil, Hossein

2016-01-01

Background: Candidiasis is one of the most prevalent and important opportunistic fungal infections of the oral cavity caused by Candida yeast species like Candida albicans, C. glabrata, and C. krusei. In addition, several bacteria can cause oral infections. The inhibition of microbial biofilm is the best way to prevent oral infections. Objectives: The aim of the present study is to evaluate the antifungal, antimicrobial, and anti-biofilm properties of ginger (Zingiber officinale) extract against Candida species and some bacterial pathogens and the extract’s effects on biofilm formation. Materials and Methods: Ginger ethanolic extract as a potential mouthwash was used to evaluate its effect against fungi and bacteria using the microdilution method, and biofilm was evaluated using the crystal violet staining method and dead/alive staining. MTT assay was used to evaluate the possible cytotoxicity effects of the extract. Results: The minimum inhibitory concentrations (MICs) of ginger extract for evaluated strains were 40, 40, 20, 20, 20, 20, 10, and 5 mg/mL for Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus cereus, Acinetobacter baumannii, C. albicans, and C. krusei, respectively. Ginger extract successfully inhibited biofilm formation by A. baumannii, B. cereus, C. krusei, and C. albicans. MTT assay revealed no significant reduction in cell viability after 24 hours. The minimum inhibitory biofilm concentrations (MIBCs) of ginger extract for fungi strains (C. krusei and C. albicans) were greater than those of fluconazole and nystatin (P = 0.000). Conclusions: The findings of the present study indicate that ginger extract has good antifungal and antibiofilm formation by fungi against C. albicans and C. Krusei. Concentrations between 0.625 mg/mL and 5 mg/mL had the highest antibiofilm and antifungal effects. Perhaps, the use of herbal extracts such as ginger represents a new era for antimicrobial therapy after developing antibiotic resistance in microbes. PMID:27127591

Panaxadiol, a purified ginseng component, enhances the anti-cancer effects of 5-fluorouracil in human colorectal cancer cells.

PubMed

Li, Xiao-Li; Wang, Chong-Zhi; Mehendale, Sangeeta R; Sun, Shi; Wang, Qi; Yuan, Chun-Su

2009-11-01

Colorectal cancer is a major cause of morbidity and mortality for cancer worldwide. Although 5-fluorouracil (5-FU) is one of the most widely used chemotherapeutic agents in first-line therapy for colorectal cancer, serious side effects limit its clinical usefulness. Panaxadiol (PD) is the purified sapogenin of ginseng saponins, which exhibit anti-tumor activity. In this study, we investigated the possible synergistic anti-cancer effects of PD and 5-FU on a human colorectal cancer cell line, HCT-116. Cell viability was evaluated by an MTS cell proliferation assay. Morphological observation was performed by crystal violet cell viability staining assay. Cell cycle distribution and apoptotic effects were analyzed by flow cytometry after staining with PI/RNase or Annexin V/PI. Cell growth was markedly suppressed in HCT-116 cells treated by 5-FU (20-100 microM) for 24 or 48 h with time-dependent effects. The significant suppression on HCT-116 cell proliferation was observed after treatment with PD (25 microM) for 24 and 48 h. Panaxadiol (25 microM) markedly (P < 0.05) enhanced the anti-proliferative effects of 5-FU (5, 10, 20 microM) on HCT-116 cells compared to single treatment of 5-FU for 24 and 48 h. Flow cytometric analysis on DNA indicated that PD and 5-FU selectively arrested cell cycle progression in the G1 phase and S phase (P < 0.01), respectively, compared to the control condition. Combination use of 5-FU with PD significantly (P < 0.001) increased cell cycle arrest in the S phase compared to that treated by 5-FU alone. The combination of 5-FU and PD significantly enhanced the percentage of apoptotic cells when compared with the corresponding cell groups treated by 5-FU alone (P < 0.001). Panaxadiol enhanced the anti-cancer effects of 5-FU on human colorectal cancer cells through the regulation of cell cycle transition and the induction of apoptotic cells.

Structural Color for Additive Manufacturing: 3D-Printed Photonic Crystals from Block Copolymers.

PubMed

Boyle, Bret M; French, Tracy A; Pearson, Ryan M; McCarthy, Blaine G; Miyake, Garret M

2017-03-28

The incorporation of structural color into 3D printed parts is reported, presenting an alternative to the need for pigments or dyes for colored parts produced through additive manufacturing. Thermoplastic build materials composed of dendritic block copolymers were designed, synthesized, and used to additively manufacture plastic parts exhibiting structural color. The reflection properties of the photonic crystals arise from the periodic nanostructure formed through block copolymer self-assembly during polymer processing. The wavelength of reflected light could be tuned across the visible spectrum by synthetically controlling the block copolymer molecular weight and manufacture parts that reflected violet, green, or orange light with the capacity to serve as selective optical filters and light guides.

Measuring the Photocatalytic Breakdown of Crystal Violet Dye using a Light Emitting Diode Approach

NASA Technical Reports Server (NTRS)

Ryan, Robert E.; Underwood, Lauren W.; O'Neal, Duane; Pagnutti, Mary; Davis, Bruce A.

2009-01-01

A simple method to estimate the photocatalytic reactivity performance of spray-on titanium dioxide coatings for transmissive glass surfaces was developed. This novel technique provides a standardized method to evaluate the efficiency of photocatalytic material systems over a variety of illumination levels. To date, photocatalysis assessments have generally been conducted using mercury black light lamps. Illumination levels for these types of lamps are difficult to vary, consequently limiting their use for assessing material performance under a diverse range of simulated environmental conditions. This new technique uses an ultraviolet (UV) gallium nitride (GaN) light emitting diode (LED) array instead of a traditional black light to initiate and sustain photocatalytic breakdown. This method was tested with a UV-resistant dye (crystal violet) applied to a titanium dioxide coated glass slide. Experimental control is accomplished by applying crystal violet to both titanium dioxide coated slides and uncoated control slides. A slide is illuminated by the UV LED array, at various light levels representative of outdoor and indoor conditions, from the dye side of the slide. To monitor degradation of the dye over time, a temperature-stabilized white light LED, whose emission spectrum overlaps with the dye absorption spectrum, is used to illuminate the opposite side of the slide. Using a spectrometer, the amount of light from the white light LED transmitted through the slide as the dye degrades is monitored as a function of wavelength and time and is subsequently analyzed. In this way, the rate of degradation for photocatalytically coated versus uncoated slide surfaces can be compared. Results demonstrate that the dye absorption decreased much more rapidly on the photocatalytically coated slides than on the control uncoated slides, and that dye degradation is dependent on illumination level. For photocatalytic activity assessment purposes, this experimental configuration and methodology minimizes many external variable effects and enables small changes in absorption to be measured. This research also compares the advantages of this innovative LED light source design over traditional mercury black light systems and non- LED lamp approaches. This novel technology begins to address the growing need for a standard method that can assess the performance of photocatalytic materials before deployment for large scale, real world use.

Comparative evaluation of methylene blue and demeclocycline for enhancing optical contrast of brain neoplasms

NASA Astrophysics Data System (ADS)

Wirth, Dennis J.

Brain tumors cause significant morbidity and mortality even when benign. Completeness of resection of brain tumors has been associated with better quality of life. However, that is often difficult to accomplish. The goal of this study was to evaluate the feasibility of using contrast enhanced multimodal confocal imaging for intraoperative detection of brain neoplasms. Different types of benign and malignant, primary and metastatic brain tumors, stained with Methylene Blue (MB) as a contrast agent, were imaged. MB is a traditional histopathologic stain that absorbs light in the red spectral range and fluoresces in the near infrared. It is FDA-approved for in vivo staining of human skin and breast tissue. Optical images showed good correlation with histopathology, demonstrating the potential of contrast enhanced multimodal confocal imaging for intraoperative detection of brain neoplasms ex vivo. However, the safety of MB for staining human brain in vivo is questionable. Demeclocycline (DMN), an antibiotic of the tetracycline family, has shown to be effective in differentiating normal from cancerous tissue in various organs. DMN is a fluorophore, which absorbs light in the violet spectral range and has a broad emission band covering green and yellow wavelengths. It is commonly used to treat infection and inflammatory disorders, and could provide a safer alternative to MB. To test this hypothesis, fresh excess human brain tissues were bisected and stained with aqueous solutions of either MB or DMN and then imaged. Reflectance and fluorescence images acquired from tissues stained with the two dyes were compared, and correlated with processed H&E histopathology. Comparison showed similar staining patterns and contrast of diagnostic features in glioblastomas, stained using either MB or DMN. The results show potential of both MB and DMN for the intraoperative detection of microscopic nests of brain neoplasms. Further studies will establish safety and efficacy of these agents in vivo.

Proteus syndrome: a case report.

PubMed

Pangkanon, S; Limpongsanurak, W; Sangtawesin, V

2001-05-01

Proteus syndrome is a rare genetic disorder, characterized by partial gigantism of the hands and/or feet, asymmetry of the limbs, plantar hyperplasia, multiple hamartomatous subcutaneous tumors, hyperostoses, and long bone overgrowth. A one day old Thai male infant is reported with macrosomia, hemihypertrophy of the left side of the face and left leg, large feet, macrodactyly of toes, plantar hyperplasia, large subcutaneous mass with a violet-red surface over the left side of the chest wall and a large port-wine stain involving the lateral aspect of the right chest wall. The clinical findings, diagnostic criteria, differential diagnosis, and management of the Proteus syndrome are reviewed.

Surface-enhanced hyper-Raman spectroscopy with a picosecond laser: gold and copper colloids

NASA Astrophysics Data System (ADS)

Lipscomb, Leigh Ann; Nie, Shuming; Feng, Sibo; Yu, Nai-Teng

1990-07-01

We have obtained surface-enhanced hyper-Raman scattering (SEHRS) spectra of crystal violet, rhodamine 6G and Ru(trpy) (BPE) 32+ adsorbed on gold and copper colloidal surfaces (where trpy=2,2',2″-terpyridine, BPE=trans-bis(4-pyridyl)ethylene). Our results demonstrate that the SEHRS effect is not intrinsically restricted to a Ag substrate and that surface enhancements at the emitted hyper-Raman photon frequencies are not required for observing SEHRS signals.

Evolution of Structural and Optical Properties of ZnO Nanorods Grown on Vacuum Annealed Seed Crystallites

PubMed Central

Khan, Fasihullah; Ajmal, Hafiz Muhammad Salman; Huda, Noor Ul; Kim, Ji Hyun; Kim, Sam-Dong

2018-01-01

In this study, the ambient condition for the as-coated seed layer (SL) annealing at 350 °C is varied from air or nitrogen to vacuum to examine the evolution of structural and optical properties of ZnO nanorods (NRs). The NR crystals of high surface density (~240 rods/μm2) and aspect ratio (~20.3) show greatly enhanced (002) degree of orientation and crystalline quality, when grown on the SLs annealed in vacuum, compared to those annealed in air or nitrogen ambient. This is due to the vacuum-annealed SL crystals of a highly preferred orientation toward (002) and large grain sizes. X-ray photoelectron spectroscopy also reveals that the highest O/Zn atomic ratio of 0.89 is obtained in the case of vacuum-annealed SL crystals, which is due to the effective desorption of hydroxyl groups and other contaminants adsorbed on the surface formed during aqueous solution-based growth process. Near band edge emission (ultra violet range of 360–400 nm) of the vacuum-annealed SLs is also enhanced by 44% and 33% as compared to those annealed in air and nitrogen ambient, respectively, in photoluminescence with significant suppression of visible light emission associated with deep level transition. Due to this improvement of SL optical crystalline quality, the NR crystals grown on the vacuum-annealed SLs produce ~3 times higher ultra violet emission intensity than the other samples. In summary, it is shown that the ZnO NRs preferentially grow along the wurtzite c-axis direction, thereby producing the high crystalline quality of nanostructures when they grow on the vacuum-annealed SLs of high crystalline quality with minimized impurities and excellent preferred orientation. The ZnO nanostructures of high crystalline quality achieved in this study can be utilized for a wide range of potential device applications such as laser diodes, light-emitting diodes, piezoelectric transducers and generators, gas sensors, and ultraviolet detectors. PMID:29373523

Photonic band-gap modulation of blue phase liquid crystal (Presentation Recording)

NASA Astrophysics Data System (ADS)

Lin, Tsung-Hsien

2015-10-01

Blue phase liquid crystals (BPLCs) are self-assembled 3D photonic crystals exhibiting high susceptibility to external stimuli. Two methods for the photonic bandgap tuning of BPs were demonstrated in this work. Introducing a chiral azobenzene into a cholesteric liquid crystal could formulate a photoresponsive BPLC. Under violet irradiation, the azo dye experiences trans-cis isomerization, which leads to lattice swelling as well as phase transition in different stages of the process. Ultrawide reversible tuning of the BP photonic bandgap from ultraviolet to near infrared has been achieved. The tuning is reversible and nonvolatile. We will then demonstract the electric field-induced bandgap tuning in polymer-stabilized BPLCs. Under different BPLCs material preparation conditions, both red-shift and broadening of the photonic bandgaps have been achieved respectively. The stop band can be shifted over 100 nm. The bandwidth can be expanded from ~ 30 nm to ~ 250 nm covering nearly the full visible range. It is believed that the developed approaches could strongly promote the use of BPLC in photonic applications.

Application potential of grapefruit peel as dye sorbent: kinetics, equilibrium and mechanism of crystal violet adsorption.

PubMed

Saeed, Asma; Sharif, Mehwish; Iqbal, Muhammad

2010-07-15

This study reports the sorption of crystal violet (CV) dye by grapefruit peel (GFP), which has application potential in the remediation of dye-contaminated wastewaters using a solid waste generated by the citrus fruit juice industry. Batch adsorption of CV was conducted to evaluate the effect of initial pH, contact time, temperature, initial dye concentration, GFP adsorbent dose, and removal of the adsorbate CV dye from aqueous solution to understand the mechanism of sorption involved. Sorption equilibrium reached rapidly with 96% CV removal in 60 min. Fit of the sorption experimental data was tested on the pseudo-first and pseudo-second-order kinetics mathematical equations, which was noted to follow the pseudo-second-order kinetics better, with coefficient of correlation > or = 0.992. The equilibrium process was well described by the Langmuir isotherm model, with maximum sorption capacity of 254.16 mg g(-1). The GFP was regenerated using 1 M NaOH, with up to 98.25% recovery of CV and could be reused as a dye sorbent in repeated cycles. GFP was also shown to be highly effective in removing CV from aqueous solution in continuous-flow fixed-bed column reactors. The study shows that GFP has the potential of application as an efficient sorbent for the removal of CV from aqueous solutions. 2010 Elsevier B.V. All rights reserved.

Recovery of low-temperature stressed E. coli O157:H7 and its susceptibility to crystal violet, bile salt, sodium chloride and ethanol.

PubMed

Chou, C C; Cheng, S J

2000-11-01

This study was conducted to investigate the alteration of some characteristics of E. coli O157:H7 subjected to various periods of storage at -5, -18 and -28 degrees C. Results revealed that the low-temperature treatments increased the susceptibility of E. coli O157:H7 to crystal violet, bile salt, sodium chloride and ethanol. In general, the susceptibility of E. coli O157:H7 subjected to storage at -18 degrees C increased most significantly. The susceptibility of E. coli O157:H7 to the tested agents increased as the period of low-temperature storage extended, regardless of storage temperature. Among the various nitrogen and carbon sources tested, tryptone and soytone were the most effective nitrogen sources, while glucose and maltose were the most effective carbon sources for the growth of the low-temperature stressed cells. When growing the stressed E. coli O157:H7 in media containing the same nitrogen source or carbon source, their lag period increased as the time of frozen storage increased. It was also noted that in general, the recovery of the low-temperature stressed E. coli O157:H7 was highest on tryptic soy agar followed by Modified eosin methylene blue agar, while recovery on MaConkey sorbitol agar and Modified MaConkey sorbitol agar was lowest.

Experimental design approach applied to the elimination of crystal violet in water by electrocoagulation with Fe or Al electrodes.

PubMed

Durango-Usuga, Paula; Guzmán-Duque, Fernando; Mosteo, Rosa; Vazquez, Mario V; Peñuela, Gustavo; Torres-Palma, Ricardo A

2010-07-15

An experimental design methodology was applied to evaluate the decolourization of crystal violet (CV) dye by electrocoagulation using iron or aluminium electrodes. The effects and interactions of four parameters, initial pH (3-9), current density (6-28 A m(-2)), substrate concentration (50-200 mg L(-1)) and supporting electrolyte concentration (284-1420 mg L(-1) of Na(2)SO(4)), were optimized and evaluated. Although the results using iron anodes were better than for aluminium, the effects and interactions of the studied parameters were quite similar. With a confidence level of 95%, initial pH and supporting electrolyte concentration showed limited effects on the removal rate of CV, whereas current density, pollutant concentration and the interaction of both were significant. Reduced models taking into account significant variables and interactions between variables have shown good correlations with the experimental results. Under optimal conditions, almost complete removal of CV and chemical oxygen demand were obtained after electrocoagulation for 5 and 30 min, using iron and aluminium electrodes, respectively. These results indicate that electrocoagulation with iron anodes is a rapid, economical and effective alternative to the complete removal of CV in waters. Evolutions of pH and residual iron or aluminium concentrations in solution are also discussed. 2010 Elsevier B.V. All rights reserved.

Multicenter evaluation of crystal violet decolorization assay (CVDA) for rapid detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis

PubMed Central

Coban, Ahmet Yilmaz; Akbal, Ahmet Ugur; Bicmen, Can; Albay, Ali; Sig, Ali Korhan; Uzun, Meltem; Selale, Deniz Sertel; Ozkutuk, Nuri; Surucuoglu, Suheyla; Albayrak, Nurhan; Ucarman, Nilay; Ozkutuk, Aydan; Esen, Nuran; Ceyhan, Ismail; Ozyurt, Mustafa; Bektore, Bayhan; Aslan, Gonul; Delialioğlu, Nuran; Alp, Alpaslan

2016-01-01

The aim of this multicenter study was to evaluate the performance of the crystal violet decolorization assay (CVDA) for detection of multidrug resistant tuberculosis (MDR-TB). This study was performed in 11 centers in two phases. A total of 156 isolates were tested for INH and RIF resistance. In the phase I, 106 clinical isolates were tested in the Center 1–7. In the phase 2, 156 clinical isolates were tested in the center 1–6, center 8–11. Eighty six of 156 tested isolates were the same in phase I. Agreements were 96.2–96.8% for INH and 98.1–98.7% for RIF in the phase I-II, respectively. Mean time to obtain the results in the phase I was 14.3 ± 5.4 days. In the phase II, mean time to obtain the results was 11.6 ± 3.5 days. Test results were obtained within 14days for 62.3% (66/106) of isolates in the phase I and 81.4% (127/156) of isolates in the phase II. In conclusion, CVDA is rapid, reliable, inexpensive, and easy to perform for rapid detection of MDR-TB isolates. In addition, it could be adapted for drug susceptibility testing with all drugs both in developed and developing countries. PMID:27982061

Multicenter evaluation of crystal violet decolorization assay (CVDA) for rapid detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis.

PubMed

Coban, Ahmet Yilmaz; Akbal, Ahmet Ugur; Bicmen, Can; Albay, Ali; Sig, Ali Korhan; Uzun, Meltem; Selale, Deniz Sertel; Ozkutuk, Nuri; Surucuoglu, Suheyla; Albayrak, Nurhan; Ucarman, Nilay; Ozkutuk, Aydan; Esen, Nuran; Ceyhan, Ismail; Ozyurt, Mustafa; Bektore, Bayhan; Aslan, Gonul; Delialioğlu, Nuran; Alp, Alpaslan

2016-12-16

The aim of this multicenter study was to evaluate the performance of the crystal violet decolorization assay (CVDA) for detection of multidrug resistant tuberculosis (MDR-TB). This study was performed in 11 centers in two phases. A total of 156 isolates were tested for INH and RIF resistance. In the phase I, 106 clinical isolates were tested in the Center 1-7. In the phase 2, 156 clinical isolates were tested in the center 1-6, center 8-11. Eighty six of 156 tested isolates were the same in phase I. Agreements were 96.2-96.8% for INH and 98.1-98.7% for RIF in the phase I-II, respectively. Mean time to obtain the results in the phase I was 14.3 ± 5.4 days. In the phase II, mean time to obtain the results was 11.6 ± 3.5 days. Test results were obtained within 14days for 62.3% (66/106) of isolates in the phase I and 81.4% (127/156) of isolates in the phase II. In conclusion, CVDA is rapid, reliable, inexpensive, and easy to perform for rapid detection of MDR-TB isolates. In addition, it could be adapted for drug susceptibility testing with all drugs both in developed and developing countries.

Batch and continuous (fixed-bed column) biosorption of crystal violet by Artocarpus heterophyllus (jackfruit) leaf powder.

PubMed

Saha, Papita Das; Chakraborty, Sagnik; Chowdhury, Shamik

2012-04-01

In this study, batch and fixed-bed column experiments were performed to investigate the biosorption potential of Artocarpus heterophyllus (jackfruit) leaf powder (JLP) to remove crystal violet (CV) from aqueous solutions. Batch biosorption studies were carried out as a function of solution pH, contact time, initial dye concentration and temperature. The biosorption equilibrium data showed excellent fit to the Langmuir isotherm model with maximum monolayer biosorption capacity of 43.39 mg g(-1) at pH 7.0, initial dye concentration=50 mg L(-1), temperature=293 K and contact time=120 min. According to Dubinin-Radushkevich (D-R) isotherm model, biosorption of CV by JLP was chemisorption. The biosorption kinetics followed the pseudo-second-order kinetic model. Thermodynamic analysis revealed that biosorption of CV from aqueous solution by JLP was a spontaneous and exothermic process. In order to ascertain the practical applicability of the biosorbent, fixed-bed column studies were also performed. The breakthrough time increased with increasing bed height and decreased with increasing flow rate. The Thomas model as well as the BDST model showed good agreement with the experimental results at all the process parameters studied. It can be concluded that JLP is a promising biosorbent for removal of CV from aqueous solutions. Copyright © 2011 Elsevier B.V. All rights reserved.

Removal of Crystal Violet by Using Reduced-Graphene-Oxide-Supported Bimetallic Fe/Ni Nanoparticles (rGO/Fe/Ni): Application of Artificial Intelligence Modeling for the Optimization Process.

PubMed

Ruan, Wenqian; Hu, Jiwei; Qi, Jimei; Hou, Yu; Cao, Rensheng; Wei, Xionghui

2018-05-22

Reduced-graphene-oxide-supported bimetallic Fe/Ni nanoparticles were synthesized in this study for the removal of crystal violet (CV) dye from aqueous solutions. This material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), Raman spectroscopy, N₂-sorption, and X-ray photoelectron spectroscopy (XPS). The influence of independent parameters (namely, initial dye concentration, initial pH, contact time, and temperature) on the removal efficiency were investigated via Box⁻Behnken design (BBD). Artificial intelligence (i.e., artificial neural network, genetic algorithm, and particle swarm optimization) was used to optimize and predict the optimum conditions and obtain the maximum removal efficiency. The zero point of charge (pH ZPC ) of rGO/Fe/Ni composites was determined by using the salt addition method. The experimental equilibrium data were fitted well to the Freundlich model for the evaluation of the actual behavior of CV adsorption, and the maximum adsorption capacity was estimated as 2000.00 mg/g. The kinetic study discloses that the adsorption processes can be satisfactorily described by the pseudo-second-order model. The values of Gibbs free energy change (Δ G ⁰), entropy change (Δ S ⁰), and enthalpy change (Δ H ⁰) demonstrate the spontaneous and endothermic nature of the adsorption of CV onto rGO/Fe/Ni composites.

Alpha-enolase on apical surface of renal tubular epithelial cells serves as a calcium oxalate crystal receptor

NASA Astrophysics Data System (ADS)

Fong-Ngern, Kedsarin; Thongboonkerd, Visith

2016-10-01

To search for a strategy to prevent kidney stone formation/recurrence, this study addressed the role of α-enolase on apical membrane of renal tubular cells in mediating calcium oxalate monohydrate (COM) crystal adhesion. Its presence on apical membrane and in COM crystal-bound fraction was confirmed by Western blotting and immunofluorescence staining. Pretreating MDCK cells with anti-α-enolase antibody, not isotype-controlled IgG, dramatically reduced cell-crystal adhesion. Immunofluorescence staining also confirmed the direct binding of purified α-enolase to COM crystals at {121} > {100} > {010} crystal faces. Coating COM crystals with urinary proteins diminished the crystal binding capacity to cells and purified α-enolase. Moreover, α-enolase selectively bound to COM, not other crystals. Chemico-protein interactions analysis revealed that α-enolase interacted directly with Ca2+ and Mg2+. Incubating the cells with Mg2+ prior to cell-crystal adhesion assay significantly reduced crystal binding on the cell surface, whereas preincubation with EDTA, a divalent cation chelator, completely abolished Mg2+ effect, indicating that COM and Mg2+ competitively bind to α-enolase. Taken together, we successfully confirmed the role of α-enolase as a COM crystal receptor to mediate COM crystal adhesion at apical membrane of renal tubular cells. It may also serve as a target for stone prevention by blocking cell-crystal adhesion and stone nidus formation.

Comparison and characterization of efficient frequency doubling at 397.5 nm with PPKTP, LBO and BiBO crystals

NASA Astrophysics Data System (ADS)

Wen, Xin; Han, Yashuai; Wang, Junmin

2016-04-01

A continuous-wave Ti:sapphire laser at 795 nm is frequency doubled in a bow-tie type enhancement four-mirror ring cavity with LiB3O5 (LBO), BiB3O6 (BiBO), and periodically polled KTiOPO4 (PPKTP) crystals, respectively. The properties of 397.5 nm ultra-violet (UV) output power, beam quality, stability for these different nonlinear crystals are investigated and compared. For PPKTP crystal, the highest doubling efficiency of 58.1% is achieved from 191 mW of 795 nm mode-matched fundamental power to 111 mW of 397.5 nm UV output. For LBO crystal, with 1.34 W of mode-matched 795 nm power, 770 mW of 397.5 nm UV output is achieved, implying a doubling efficiency of 57.4%. For BiBO crystal, with 323 mW of mode-matched 795 nm power, 116 mW of 397.5 nm UV output is achieved, leading to a doubling efficiency of 35.9%. The generated UV radiation has potential applications in the fields of quantum physics.

Chemical Composition, Antibacterial, Antibiofilm and Synergistic Properties of Essential Oils from Eucalyptus globulus Labill. and Seven Mediterranean Aromatic Plants.

PubMed

Vieira, Maria; Bessa, Lucinda J; Martins, M Rosário; Arantes, Sílvia; Teixeira, António P S; Mendes, Ângelo; Martins da Costa, Paulo; Belo, Anabela D F

2017-06-01

Essential oils (EOs) from Eucalyptus globulus Labill. ssp. globulus and from Mediterranean autochthonous aromatic plants - Thymus mastichina L., Mentha pulegium L., Rosmarinus officinalis L., Calamintha nepeta (L.) Savi ssp. nepeta, Cistus ladanifer L., Foeniculum vulgare L., Dittrichia viscosa (L.) Greuter ssp. viscosa - were extracted by hydrodistillation and characterized by GC-FID and NMR spectroscopy. EOs were evaluated for antimicrobial properties against several bacterial strains, using diverse methods, namely, the agar disc-diffusion method, the microdilution method, the crystal violet assay and the Live/Dead staining for assessment of biofilm formation. Potential synergy was assessed by a checkerboard method. EOs of R. officinalis and C. ladanifer showed a predominance in monoterpene hydrocarbons (> 60%); EOs of C. nepeta, M. pulegium, T. mastichina, E. globulus and F. vulgare were rich in oxygenated monoterpenes (62 - 96%) whereas EO of D. viscosa was mainly composed of oxygenated sesquiterpenes (54%). All EOs showed antimicrobial activity; M. pulegium and E. globulus generally had the strongest antimicrobial activity. EO of C. nepeta was the most promising in hampering the biofilm formation. The combinations D. viscosa/C. nepeta and E. globulus/T. mastichina were synergistic against Staphylococcus aureus. These results support the notion that EOs from the aromatic plants herein reported should be further explored as potential pharmaceuticals and/or food preservatives. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Stenotrophomonas maltophilia in Mexico: antimicrobial resistance, biofilm formation and clonal diversity.

PubMed

Flores-Treviño, Samantha; Gutiérrez-Ferman, Jessica Lizzeth; Morfín-Otero, Rayo; Rodríguez-Noriega, Eduardo; Estrada-Rivadeneyra, Diego; Rivas-Morales, Catalina; Llaca-Díaz, Jorge M; Camacho-Ortíz, Adrián; Mendoza-Olazarán, Soraya; Garza-González, Elvira

2014-11-01

Stenotrophomonas maltophilia is an important multidrug-resistant nosocomial pathogen associated with high mortality. Our aim was to examine antimicrobial susceptibility, biofilm production and clonal relatedness of clinical isolates of S. maltophilia. S. maltophilia isolates were collected between 2006 and 2013 from two tertiary care hospitals in Mexico. Antimicrobial susceptibility was evaluated by the broth microdilution method. PCR was used to determine the presence of β-lactamase genes L1 and L2. Biofilm formation was assessed with crystal violet staining. Clonal relatedness was determined by PFGE. Among the 119 collected S. maltophilia isolates, 73 (61.3%) were from the respiratory tract. Resistance levels exceeded 75% for imipenem, meropenem, ampicillin, aztreonam, gentamicin and tobramycin. Resistance to trimethoprim-sulfamethoxazole was 32.8%. L1 and L2 genes were detected in 77.1% (91/118) and 66.9% (79/118) of isolates, respectively. All S. maltophilia strains were able to produce biofilms. Strains were classified as weak (47.9%, 57/119), moderate (38.7%, 46/119), or strong (13.4%, 16/119) biofilm producers. A total of 89 distinct PFGE types were identified and 21.6% (22/102) of the isolates were distributed in nine clusters. This is the first study in Mexico to reveal characteristics of clinical isolates of S. maltophilia. Clonal diversity data indicate low cross-transmission of S. maltophilia in a hospital setting. The high antibiotic resistance underscores the need for continuous surveillance of S. maltophilia in hospital settings in Mexico. © 2014 The Authors.

Silver colloidal nanoparticles: antifungal effect against adhered cells and biofilms of Candida albicans and Candida glabrata.

PubMed

Monteiro, D R; Gorup, L F; Silva, S; Negri, M; de Camargo, E R; Oliveira, R; Barbosa, D B; Henriques, M

2011-08-01

The aim of this study was to evaluate the effect of silver nanoparticles (SN) against Candida albicans and Candida glabrata adhered cells and biofilms. SN (average diameter 5 nm) were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. Minimal inhibitory concentration (MIC) tests were performed for C. albicans (n = 2) and C. glabrata (n = 2) grown in suspension following the Clinical Laboratory Standards Institute microbroth dilution method. SN were applied to adhered cells (2 h) or biofilms (48 h) and after 24 h of contact their effect was assessed by enumeration of colony forming units (CFUs) and quantification of total biomass (by crystal violet staining). The MIC results showed that SN were fungicidal against all strains tested at very low concentrations (0.4-3.3 μg ml(-1)). Furthermore, SN were more effective in reducing biofilm biomass when applied to adhered cells (2 h) than to pre-formed biofilms (48 h), with the exception of C. glabrata ATCC, which in both cases showed a reduction ∼90%. Regarding cell viability, SN were highly effective on adhered C. glabrata and respective biofilms. On C. albicans the effect was not so evident but there was also a reduction in the number of viable biofilm cells. In summary, SN may have the potential to be an effective alternative to conventional antifungal agents for future therapies in Candida-associated denture stomatitis.

Rapid degradation of Streptococcus pyogenes biofilms by PlyC, a bacteriophage-encoded endolysin.

PubMed

Shen, Yang; Köller, Thomas; Kreikemeyer, Bernd; Nelson, Daniel C

2013-08-01

Streptococcus pyogenes, or Group A streptococcus (GAS), has a propensity to colonize human tissues and form biofilms. Significantly, these biofilms are a contributing mechanism of antibiotic treatment failure in streptococcal disease. In this study, we evaluate a streptococcal-specific bacteriophage-encoded endolysin (PlyC), which is known to lyse planktonic streptococci, on both static and dynamic streptococcal biofilms. PlyC was benchmarked against antibiotics for MIC, MBC and minimum biofilm eradication concentration (MBEC). A biomass eradication assay based on crystal violet staining of the biofilm matrix was also used to quantify the anti-biofilm properties of PlyC. Finally, conventional fluorescence microscopy and laser scanning confocal microscopy were used to study the effects of PlyC on static and dynamic biofilms of GAS. PlyC and antibiotics had similar MIC (range 0.02-0.08 mg/L) and MBC (range 0.02-1.25 mg/L) values on planktonic GAS. However, when GAS grew in biofilms, the MBEC values for antibiotics rose to clinically resistant values (≥400 mg/L) whereas PlyC had MBEC values two orders of magnitude lower by mass and four orders of magnitude lower by molarity than the conventional antibiotics. Laser scanning confocal microscopy revealed that PlyC destroys the biofilm as it diffuses through the matrix in a time-dependent fashion. Our findings indicate that while streptococcal cells within a biofilm rapidly become refractory to traditional antibiotics, the biofilm matrix is readily destroyed by the lytic actions of PlyC.

Biofilm formation in Malassezia pachydermatis strains isolated from dogs decreases susceptibility to ketoconazole and itraconazole.

PubMed

Jerzsele, Akos; Gyetvai, Béla; Csere, István; Gálfi, Péter

2014-12-01

Malassezia pachydermatis is a commonly isolated yeast in veterinary dermatology that can produce biofilms in vitro and in vivo, lowering its susceptibility to antimicrobial drugs. The aim of this study was to determine and compare the in vitro susceptibility of planktonic cells and biofilms of M. pachydermatis isolates to ketoconazole and itraconazole. The presence of biofilm formation was confirmed by crystal violet staining and absorbance measurement at 595 nm wavelength, and by a scanning electron microscopy method. Cell viability was determined by the Celltiter 96 Aqueous One solution assay containing a water-soluble tetrazolium compound (MTS) with absorbance measurement at 490 nm. Planktonic cell minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of ketoconazole and itraconazole were very low: MIC90 and MFC90 were 0.032 and 0.125 μg/ml for ketoconazole, while 0.063 and 0.25 μg/ml for itraconazole, respectively. Also, the half maximal effective concentrations (EC50) of itraconazole were higher for planktonic cells and biofilms compared to ketoconazole. The EC50 values of ketoconazole were 18-169 times higher and those of itraconazole 13-124 times higher for biofilms than for planktonic cells. Biofilm EC50 levels exceeded MICs 103-2060 times for ketoconazole and 84-1400 times for itraconazole. No significant difference was found between these values of the two substances. In conclusion, biofilms of all examined M. pachydermatis strains were much less susceptible to ketoconazole and itraconazole than their planktonic forms.

Antitumor effects of nano-bubble hydrogen-dissolved water are enhanced by coexistent platinum colloid and the combined hyperthermia with apoptosis-like cell death.

PubMed

Asada, Ryoko; Kageyama, Katsuhiro; Tanaka, Hiroshi; Matsui, Hisakazu; Kimura, Masatsugu; Saitoh, Yasukazu; Miwa, Nobuhiko

2010-12-01

In order to erase reactive oxygen species (ROS) related with the proliferation of tumor cells by reducing activity of hydrogen, we developed functional water containing nano-bubbles (diameters: <900 nm for 71%/population) hydrogen of 1.1-1.5 ppm (the theoretical maximum: 1.6 ppm) with a reducing ability (an oxidation-reduction potential -650 mV, normal water: +100-200 mV) using a microporous-filter hydrogen-jetting device. We showed that hydrogen water erased ROS indispensable for tumor cell growth by ESR/spin trap, the redox indicator CDCFH-DA assay, and was cytotoxic to Ehrlich ascites tumor cells as assessed by WST-8 assay, crystal violet dye stain and scanning electron microscopy, after 24-h or 48-h incubation sequent to warming at 37°C or 42°C. Hydrogen water supplemented with platinum colloid (0.3 ppm Pt in 4% polyvinylpyrrolidone) had more antitumor activity than hydrogen water alone, mineral water alone (15.6%), hydrogen water plus mineral water, or platinum colloid alone as observed by decreased cell numbers, cell shrinkage and pycnosis (nuclear condensation)/karyorrhexis (nuclear fragmentation) indicative of apoptosis, together with cell deformation and disappearance of microvilli on the membrane surface. These antitumor effects were promoted by combination with hyperthermia at 42°C. Thus, the nano-bubble hydrogen water with platinum colloid is potent as an anti-tumor agent.

Biofilm Formation Characteristics of Pseudomonas lundensis Isolated from Meat.

PubMed

Liu, Yong-Ji; Xie, Jing; Zhao, Li-Jun; Qian, Yun-Fang; Zhao, Yong; Liu, Xiao

2015-12-01

Biofilms formations of spoilage and pathogenic bacteria on food or food contact surfaces have attracted increasing attention. These events may lead to a higher risk of food spoilage and foodborne disease transmission. While Pseudomonas lundensis is one of the most important bacteria that cause spoilage in chilled meat, its capability for biofilm formation has been seldom reported. Here, we investigated biofilm formation characteristics of P. lundensis mainly by using crystal violet staining, and confocal laser scanning microscopy (CLSM). The swarming and swimming motility, biofilm formation in different temperatures (30, 10, and 4 °C) and the protease activity of the target strain were also assessed. The results showed that P. lundensis showed a typical surface-associated motility and was quite capable of forming biofilms in different temperatures (30, 10, and 4 °C). The strain began to adhere to the contact surfaces and form biofilms early in the 4 to 6 h. The biofilms began to be formed in massive amounts after 12 h at 30 °C, and the extracellular polysaccharides increased as the biofilm structure developed. Compared with at 30 °C, more biofilms were formed at 4 and 10 °C even by a low bacterial density. The protease activity in the biofilm was significantly correlated with the biofilm formation. Moreover, the protease activity in biofilm was significantly higher than that of the corresponding planktonic cultures after cultured 12 h at 30 °C. © 2015 Institute of Food Technologists®

Maggot excretions inhibit biofilm formation on biomaterials.

PubMed

Cazander, Gwendolyn; van de Veerdonk, Mariëlle C; Vandenbroucke-Grauls, Christina M J E; Schreurs, Marco W J; Jukema, Gerrolt N

2010-10-01

Biofilm-associated infections in trauma surgery are difficult to treat with conventional therapies. Therefore, it is important to develop new treatment modalities. Maggots in captured bags, which are permeable for larval excretions/secretions, aid in healing severe, infected wounds, suspect for biofilm formation. Therefore we presumed maggot excretions/secretions would reduce biofilm formation. We studied biofilm formation of Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella oxytoca, Enterococcus faecalis, and Enterobacter cloacae on polyethylene, titanium, and stainless steel. We compared the quantities of biofilm formation between the bacterial species on the various biomaterials and the quantity of biofilm formation after various incubation times. Maggot excretions/secretions were added to existing biofilms to examine their effect. Comb-like models of the biomaterials, made to fit in a 96-well microtiter plate, were incubated with bacterial suspension. The formed biofilms were stained in crystal violet, which was eluted in ethanol. The optical density (at 595 nm) of the eluate was determined to quantify biofilm formation. Maggot excretions/secretions were pipetted in different concentrations to (nonstained) 7-day-old biofilms, incubated 24 hours, and finally measured. The strongest biofilms were formed by S. aureus and S. epidermidis on polyethylene and the weakest on titanium. The highest quantity of biofilm formation was reached within 7 days for both bacteria. The presence of excretions/secretions reduced biofilm formation on all biomaterials. A maximum of 92% of biofilm reduction was measured. Our observations suggest maggot excretions/secretions decrease biofilm formation and could provide a new treatment for biofilm formation on infected biomaterials.

Porphyromonas gingivalis displays a competitive advantage over Aggregatibacter actinomycetemcomitans in co-cultured biofilm.

PubMed

Takasaki, K; Fujise, O; Miura, M; Hamachi, T; Maeda, K

2013-06-01

Biofilm formation occurs through the events of cooperative growth and competitive survival among multiple species. Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans are important periodontal pathogens. The aim of this study was to demonstrate competitive or cooperative interactions between these two species in co-cultured biofilm. P. gingivalis strains and gingipain mutants were cultured with or without A. actinomycetemcomitans. Biofilms formed on glass surfaces were analyzed by crystal violet staining and colony counting. Preformed A. actinomycetemcomitans biofilms were treated with P. gingivalis culture supernatants. Growth and proteolytic activities of gingipains were also determined. Monocultured P. gingivalis strains exhibited a range of biofilm-formation abilities and proteolytic activities. The ATCC33277 strain, noted for its high biofilm-formation ability and proteolytic activity, was found to be dominant in biofilm co-cultured with A. actinomycetemcomitans. In a time-resolved assay, A. actinomycetemcomitans was primarily the dominant colonizer on a glass surface and subsequently detached in the presence of increasing numbers of ATCC33277. Detachment of preformed A. actinomycetemcomitans biofilm was observed by incubation with culture supernatants from highly proteolytic strains. These results suggest that P. gingivalis possesses a competitive advantage over A. actinomycetemcomitans. As the required biofilm-formation abilities and proteolytic activities vary among P. gingivalis strains, the diversity of the competitive advantage is likely to affect disease recurrence during periodontal maintenance. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Candida virulence and ethanol-derived acetaldehyde production in oral cancer and non-cancer subjects.

PubMed

Alnuaimi, A D; Ramdzan, A N; Wiesenfeld, D; O'Brien-Simpson, N M; Kolev, S D; Reynolds, E C; McCullough, M J

2016-11-01

To compare biofilm-forming ability, hydrolytic enzymes and ethanol-derived acetaldehyde production of oral Candida isolated from the patients with oral cancer and matched non-oral cancer. Fungal biofilms were grown in RPMI-1640 medium, and biofilm mass and biofilm activity were assessed using crystal violet staining and XTT salt reduction assays, respectively. Phospholipase, proteinase, and esterase production were measured using agar plate method, while fungal acetaldehyde production was assessed via gas chromatography. Candida isolated from patients with oral cancer demonstrated significantly higher biofilm mass (P = 0.031), biofilm metabolic activity (P < 0.001), phospholipase (P = 0.002), and proteinase (P = 0.0159) activity than isolates from patients with non-oral cancer. High ethanol-derived acetaldehyde-producing Candida were more prevalent in patients with oral cancer than non-oral cancer (P = 0.01). In univariate regression analysis, high biofilm mass (P = 0.03) and biofilm metabolic activity (P < 0.001), high phospholipase (P = 0.003), and acetaldehyde production ability (0.01) were significant risk factors for oral cancer; while in the multivariate regression analysis, high biofilm activity (0.01) and phospholipase (P = 0.01) were significantly positive influencing factors on oral cancer. These data suggest a significant positive association between the ability of Candida isolates to form biofilms, to produce hydrolytic enzymes, and to metabolize alcohol to acetaldehyde with their ability to promote oral cancer development. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Angiogenic effects of apigenin on endothelial cells after hypoxia-reoxygenation via the caveolin-1 pathway.

PubMed

Tu, Fengxia; Pang, Qiongyi; Chen, Xiang; Huang, Tingting; Liu, Meixia; Zhai, Qiongxiang

2017-12-01

In the present study, we aimed to elucidate whether apigenin contributes to the induction of angiogenesis and the related mechanisms in cell hypoxia-reoxygenation injury. The role of apigenin was examined in human umbilical vein endothelial cell (HUVEC) viability, migration and tube formation in vitro. To investigate the related mechanisms, we used caveolin-1 short interfering RNA. The viability of HUVECs was measured using Cell Counting Kit-8 assays, HUVEC migration was analyzed by crystal violet staining, and a tube formation assay was performed using the branch point method. Expression of caveolin-1, vascular endothelial growth factor (VEGF), and endothelial nitric oxide synthase (eNOS) in HUVECs was examined by polymerase chain reaction and western blotting. Our data revealed that apigenin induced angiogenesis in vitro by increasing the tube formation ability of HUVECs, which was counteracted by caveolin-1 silencing. Compared to the NC group, Caveolin-1 and eNOS expression was upregulated by apigenin, whereas compared to the NC group, eNOS expression was increased upon caveolin-1 silencing. The expression of VEGF was increased by treatment with apigenin; however, compared to the NC group, caveolin-1 silencing did not affect VEGF expression, and apigenin did not increase VEGF expression in HUVECs after caveolin-1 silencing. These data suggest that apigenin may be a candidate therapeutic target for stroke recovery by promoting angiogenesis via the caveolin-1 signaling pathway.

Development of an in vitro Assay, Based on the BioFilm Ring Test®, for Rapid Profiling of Biofilm-Growing Bacteria

PubMed Central

Di Domenico, Enea G.; Toma, Luigi; Provot, Christian; Ascenzioni, Fiorentina; Sperduti, Isabella; Prignano, Grazia; Gallo, Maria T.; Pimpinelli, Fulvia; Bordignon, Valentina; Bernardi, Thierry; Ensoli, Fabrizio

2016-01-01

Microbial biofilm represents a major virulence factor associated with chronic and recurrent infections. Pathogenic bacteria embedded in biofilms are highly resistant to environmental and chemical agents, including antibiotics and therefore difficult to eradicate. Thus, reliable tests to assess biofilm formation by bacterial strains as well as the impact of chemicals or antibiotics on biofilm formation represent desirable tools for a most effective therapeutic management and microbiological risk control. Current methods to evaluate biofilm formation are usually time-consuming, costly, and hardly applicable in the clinical setting. The aim of the present study was to develop and assess a simple and reliable in vitro procedure for the characterization of biofilm-producing bacterial strains for future clinical applications based on the BioFilm Ring Test® (BRT) technology. The procedure developed for clinical testing (cBRT) can provide an accurate and timely (5 h) measurement of biofilm formation for the most common pathogenic bacteria seen in clinical practice. The results gathered by the cBRT assay were in agreement with the traditional crystal violet (CV) staining test, according to the κ coefficient test (κ = 0.623). However, the cBRT assay showed higher levels of specificity (92.2%) and accuracy (88.1%) as compared to CV. The results indicate that this procedure offers an easy, rapid and robust assay to test microbial biofilm and a promising tool for clinical microbiology. PMID:27708625

Cranberry proanthocyanidins inhibit the adherence properties of Candida albicans and cytokine secretion by oral epithelial cells

PubMed Central

2012-01-01

Background Oral candidiasis is a common fungal disease mainly caused by Candida albicans. The aim of this study was to investigate the effects of A-type cranberry proanthocyanidins (AC-PACs) on pathogenic properties of C. albicans as well as on the inflammatory response of oral epithelial cells induced by this oral pathogen. Methods Microplate dilution assays were performed to determine the effect of AC-PACs on C. albicans growth as well as biofilm formation stained with crystal violet. Adhesion of FITC-labeled C. albicans to oral epithelial cells and to acrylic resin disks was monitored by fluorometry. The effects of AC-PACs on C. albicans-induced cytokine secretion, nuclear factor-kappa B (NF-κB) p65 activation and kinase phosphorylation in oral epithelial cells were determined by immunological assays. Results Although AC-PACs did not affect growth of C. albicans, it prevented biofilm formation and reduced adherence of C. albicans to oral epithelial cells and saliva-coated acrylic resin discs. In addition, AC-PACs significantly decreased the secretion of IL-8 and IL-6 by oral epithelial cells stimulated with C. albicans. This anti-inflammatory effect was associated with reduced activation of NF-κB p65 and phosphorylation of specific signal intracellular kinases. Conclusion AC-PACs by affecting the adherence properties of C. albicans and attenuating the inflammatory response induced by this pathogen represent potential novel therapeutic agents for the prevention/treatment of oral candidiasis. PMID:22248145

Berberine inhibits the chemotherapy-induced repopulation by suppressing the arachidonic acid metabolic pathway and phosphorylation of FAK in ovarian cancer.

PubMed

Zhao, Yawei; Cui, Lianzhi; Pan, Yue; Shao, Dan; Zheng, Xiao; Zhang, Fan; Zhang, Hansi; He, Kan; Chen, Li

2017-12-01

Cytotoxic chemotherapy is an effective and traditional treatment of ovarian cancer. However, chemotherapy-induced apoptosis may also trigger and ultimately accelerate the repopulation of the small number of adjacent surviving cells. This study mainly focused on the tumour cell repopulation caused by chemotherapy in ovarian cancer and the adjunctive/synergistic effect of Berberine on the prevention of tumour repopulation. The transwell system was used to mimic the co-culture of surviving ovarian cancer cells in the microenvironment of cytotoxic chemotherapy-treated dying cells. Tumour cell proliferation was observed by crystal violet staining. AA and PGE 2 levels were measured by ELISA, and changes of protein expression were analysed by Western blot. Chemotherapy drug VP16 treatment triggered AA pathway, leading to the elevated PGE 2 level, and ultimately enhanced the repopulation of ovarian cancer cells. Berberine can block the caspase 3-iPLA 2 -AA-COX-2-PGE 2 pathway by inhibiting the expression of iPLA 2 and COX-2. Berberine can also reverse the increased phosphorylation of FAK caused by abnormal PGE 2 level and thus reverse the repopulation of ovarian cancer cells after VP16 treatment. Our observation suggested that Berberine could inhibit the chemotherapy-induced repopulation of ovarian cancer cells by suppressing the AA pathway and phosphorylation of FAK. And these findings implicated a novel combined use of Berberine and chemotherapeutics, which might prevent ovarian cancer recurrence by abrogating early tumour repopulation. © 2017 John Wiley & Sons Ltd.

Inhibition of Staphylococcus epidermidis Biofilm Formation by Traditional Thai Herbal Recipes Used for Wound Treatment

PubMed Central

Chusri, S.; Sompetch, K.; Mukdee, S.; Jansrisewangwong, S.; Srichai, T.; Maneenoon, K.; Limsuwan, S.; Voravuthikunchai, S. P.

2012-01-01

Development of biofilm is a key mechanism involved in Staphylococcus epidermidis virulence during device-associated infections. We aimed to investigate antibiofilm formation and mature biofilm eradication ability of ethanol and water extracts of Thai traditional herbal recipes including THR-SK004, THR-SK010, and THR-SK011 against S. epidermidis. A biofilm forming reference strain, S. epidermidis ATCC 35984 was employed as a model for searching anti-biofilm agents by MTT reduction assay. The results revealed that the ethanol extract of THR-SK004 (THR-SK004E) could inhibit the formation of S. epidermidis biofilm on polystyrene surfaces. Furthermore, treatments with the extract efficiently inhibit the biofilm formation of the pathogen on glass surfaces determined by scanning electron microscopy and crystal violet staining. In addition, THR-SK010 ethanol extract (THR-SK010E; 0.63–5 μg/mL) could decrease 30 to 40% of the biofilm development. Almost 90% of a 7-day-old staphylococcal biofilm was destroyed after treatment with THR-SK004E (250 and 500 μg/mL) and THR-SK010E (10 and 20 μg/mL) for 24 h. Therefore, our results clearly demonstrated THR-SK004E could prevent the staphylococcal biofilm development, whereas both THR-SK004E and THR-SK010E possessed remarkable eradication ability on the mature staphylococcal biofilm. PMID:22919409

Comparing the efficacy of hyper-pure chlorine-dioxide with other oral antiseptics on oral pathogen microorganisms and biofilm in vitro.

PubMed

Herczegh, Anna; Gyurkovics, Milán; Agababyan, Hayk; Ghidán, Agoston; Lohinai, Zsolt

2013-09-01

This study examines the antibacterial properties of sodium hypochlorite (NaOCl), chlorhexidine gluconate (CHX), Listerine®, and high purity chlorine dioxide (Solumium, ClO2) on selected common oral pathogen microorganisms and on dental biofilm in vitro. Antimicrobial activity of oral antiseptics was compared to the gold standard phenol. We investigated Streptococcus mutans, Lactobacillus acidophilus, Enterococcus faecalis, Veillonella alcalescens, Eikenella corrodens, Actinobacillus actinomycetemcomitans and Candida albicans as some important representatives of the oral pathogens. Furthermore, we collected dental plaque from the upper first molars of healthy young students. Massive biofilm was formed in vitro and its reduction was measured after treating it with mouthrinses: CHX, Listerine® or hyper pure ClO2. Their biofilm disrupting effect was measured after dissolving the crystal violet stain from biofilm by photometer. The results have showed that hyper pure ClO2 solution is more effective than other currently used disinfectants in case of aerobic bacteria and Candida yeast. In case of anaerobes its efficiency is similar to CHX solution. The biofilm dissolving effect of hyper pure ClO2 is significantly stronger compared to CHX and Listerine® after 5 min treatment. In conclusion, hyper pure ClO2 has a potent disinfectant efficacy on oral pathogenic microorganisms and a powerful biofilm dissolving effect compared to the current antiseptics, therefore high purity ClO2 may be a new promising preventive and therapeutic adjuvant in home oral care and in dental or oral surgery practice.

Reactive Oxygen Species Mediated Bacterial Biofilm Inhibition via Zinc Oxide Nanoparticles and Their Statistical Determination

PubMed Central

Dwivedi, Sourabh; Wahab, Rizwan; Khan, Farheen; Mishra, Yogendra K.; Musarrat, Javed; Al-Khedhairy, Abdulaziz A.

2014-01-01

The formation of bacterial biofilm is a major challenge in clinical applications. The main aim of this study is to describe the synthesis, characterization and biocidal potential of zinc oxide nanoparticles (NPs) against bacterial strain Pseudomonas aeruginosa. These nanoparticles were synthesized via soft chemical solution process in a very short time and their structural properties have been investigated in detail by using X-ray diffraction and transmission electron microscopy measurements. In this work, the potential of synthesized ZnO-NPs (∼10–15 nm) has been assessed in-vitro inhibition of bacteria and the formation of their biofilms was observed using the tissue culture plate assays. The crystal violet staining on biofilm formation and its optical density revealed the effect on biofilm inhibition. The NPs at a concentration of 100 µg/mL significantly inhibited the growth of bacteria and biofilm formation. The biofilm inhibition by ZnO-NPs was also confirmed via bio-transmission electron microscopy (Bio-TEM). The Bio-TEM analysis of ZnO-NPs treated bacteria confirmed the deformation and damage of cells. The bacterial growth in presence of NPs concluded the bactericidal ability of NPs in a concentration dependent manner. It has been speculated that the antibacterial activity of NPs as a surface coating material, could be a feasible approach for controlling the pathogens. Additionally, the obtained bacterial solution data is also in agreement with the results from statistical analytical methods. PMID:25402188

Reactive oxygen species mediated bacterial biofilm inhibition via zinc oxide nanoparticles and their statistical determination.

PubMed

Dwivedi, Sourabh; Wahab, Rizwan; Khan, Farheen; Mishra, Yogendra K; Musarrat, Javed; Al-Khedhairy, Abdulaziz A

2014-01-01

The formation of bacterial biofilm is a major challenge in clinical applications. The main aim of this study is to describe the synthesis, characterization and biocidal potential of zinc oxide nanoparticles (NPs) against bacterial strain Pseudomonas aeruginosa. These nanoparticles were synthesized via soft chemical solution process in a very short time and their structural properties have been investigated in detail by using X-ray diffraction and transmission electron microscopy measurements. In this work, the potential of synthesized ZnO-NPs (∼ 10-15 nm) has been assessed in-vitro inhibition of bacteria and the formation of their biofilms was observed using the tissue culture plate assays. The crystal violet staining on biofilm formation and its optical density revealed the effect on biofilm inhibition. The NPs at a concentration of 100 µg/mL significantly inhibited the growth of bacteria and biofilm formation. The biofilm inhibition by ZnO-NPs was also confirmed via bio-transmission electron microscopy (Bio-TEM). The Bio-TEM analysis of ZnO-NPs treated bacteria confirmed the deformation and damage of cells. The bacterial growth in presence of NPs concluded the bactericidal ability of NPs in a concentration dependent manner. It has been speculated that the antibacterial activity of NPs as a surface coating material, could be a feasible approach for controlling the pathogens. Additionally, the obtained bacterial solution data is also in agreement with the results from statistical analytical methods.

Killing activity of LFchimera on periodontopathic bacteria and multispecies oral biofilm formation in vitro.

PubMed

Ruangcharoen, Sopita; Suwannarong, Waraporn; Lachica, Marie Rossini Carmela T; Bolscher, Jan G M; Nazmi, Kamran; Khunkitti, Watcharee; Taweechaisupapong, Suwimol

2017-08-19

Lactoferrin chimera (LFchimera), a heterodimeric peptide containing lactoferrampin (LFampin265-284) and a part of lactoferricin (LFcin17-30), possesses a broad spectrum of antimicrobial activity. However, there is no report on the inhibitory effects of LFchimera against multispecies oral biofilms. This study aimed to determine the effects of LFchimera in comparison to chlorhexidine digluconate (CHX) and minocycline hydrochloride (MH), on in vitro multispecies biofilms derived from subgingival plaque of periodontitis patients harboring Aggregatibacter actinomycetemcomitans. First the effects of LFchimera against planktonic and an 1-day old biofilm of the periodontopathic bacteria, A. actinomycetemcomitans ATCC 43718 were established. Then, the effects on biofilm formation and bacterial viability in the multispecies biofilm were determined by crystal violet staining and LIVE/DEAD BacLight Bacterial Viability kit, respectively. The results revealed that a significant reduction (P < 0.05) in biofilm formation occurred after 15 min exposure to 20 µM of LFchimera or CHX compared to control. In contrast, MH at concentration up to 100 µM did not inhibit biofilm formation. The ratio of live/dead bacteria in biofilm was also significantly lower after 15 min exposure to 20 µM of LFchimera compared to control and 20-50 µM of CHX and MH. Altogether, the results obtained indicate that LFchimera is able to inhibit in vitro subgingival biofilm formation and reduce viability of multispecies bacteria in biofilm better than CHX and MH.

Sirc-cvs cytotoxicity test: an alternative for predicting rodent acute systemic toxicity.

PubMed

Kitagaki, Masato; Wakuri, Shinobu; Hirota, Morihiko; Tanaka, Noriho; Itagaki, Hiroshi

2006-10-01

An in vitro crystal violet staining method using the rabbit cornea-derived cell line (SIRC-CVS) has been developed as an alternative to predict acute systemic toxicity in rodents. Seventy-nine chemicals, the in vitro cytotoxicity of which was already reported by the Multicenter Evaluation of In vitro Toxicity (MEIC) and ICCVAM/ECVAM, were selected as test compounds. The cells were incubated with the chemicals for 72 hrs and the IC(50) and IC(35) values (microg/mL) were obtained. The results were compared to the in vivo (rat or mouse) "most toxic" oral, intraperitoneal, subcutaneous and intravenous LD(50) values (mg/kg) taken from the RTECS database for each of the chemicals by using Pearson's correlation statistics. The following parameters were calculated: accuracy, sensitivity, specificity, prevalence, positive predictability, and negative predictability. Good linear correlations (Pearson's coefficient; r>0.6) were observed between either the IC(50) or the IC(35) values and all the LD(50) values. Among them, a statistically significant high correlation (r=0.8102, p<0.001) required for acute systemic toxicity prediction was obtained between the IC(50) values and the oral LD(50) values. By using the cut-off concentrations of 2,000 mg/kg (LD(50)) and 4,225 microg/mL (IC(50)), no false negatives were observed, and the accuracy was 84.8%. From this, it is concluded that this method could be used to predict the acute systemic toxicity potential of chemicals in rodents.

Electron Microscope Study of Sporulation and Parasporal Crystal Formation in Bacillus thuringiensis

PubMed Central

Bechtel, Donald B.; Bulla, Lee A.

1976-01-01

A comprehensive ultrastructural analysis of sporulation and parasporal crystal development is described for Bacillus thuringiensis. The insecticidal crystal of B. thuringiensis is initiated at the start of engulfment and is nearly complete by the time the exosporium forms. The crystal and a heretofore unobserved ovoid inclusion develop without any clear association with the forespore septum, exosporium, or mesosomes. These observations contradict previous hypotheses that the crystal is synthesized on the forespore membrane, exosporium, or mesosomes. Formation of forespore septa involves densely staining, double-membrane-bound, vesicular mesosomes that have a bridged appearance. Forespore engulfment is subpolar and also involves mesosomes. Upon completion of engulfment the following cytoplasmic changes occur: decrease in electron density of the incipient forespore membrane; loss of bridged appearance of incipient forespore membrane; change in stainability of incipient forespore, forespore, and mother cell cytoplasms; and alteration in staining quality of plasma membrane. These changes are involved in the conversion of the incipient forespore into a forespore and reflect “commitment” to sporulation. Images PMID:182671

Localization microscopy of DNA in situ using Vybrant{sup ®} DyeCycle™ Violet fluorescent probe: A new approach to study nuclear nanostructure at single molecule resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Żurek-Biesiada, Dominika; Szczurek, Aleksander T.; Prakash, Kirti

Higher order chromatin structure is not only required to compact and spatially arrange long chromatids within a nucleus, but have also important functional roles, including control of gene expression and DNA processing. However, studies of chromatin nanostructures cannot be performed using conventional widefield and confocal microscopy because of the limited optical resolution. Various methods of superresolution microscopy have been described to overcome this difficulty, like structured illumination and single molecule localization microscopy. We report here that the standard DNA dye Vybrant{sup ®} DyeCycle™ Violet can be used to provide single molecule localization microscopy (SMLM) images of DNA in nuclei ofmore » fixed mammalian cells. This SMLM method enabled optical isolation and localization of large numbers of DNA-bound molecules, usually in excess of 10{sup 6} signals in one cell nucleus. The technique yielded high-quality images of nuclear DNA density, revealing subdiffraction chromatin structures of the size in the order of 100 nm; the interchromatin compartment was visualized at unprecedented optical resolution. The approach offers several advantages over previously described high resolution DNA imaging methods, including high specificity, an ability to record images using a single wavelength excitation, and a higher density of single molecule signals than reported in previous SMLM studies. The method is compatible with DNA/multicolor SMLM imaging which employs simple staining methods suited also for conventional optical microscopy. - Highlights: • Super-resolution imaging of nuclear DNA with Vybrant Violet and blue excitation. • 90nm resolution images of DNA structures in optically thick eukaryotic nuclei. • Enhanced resolution confirms the existence of DNA-free regions inside the nucleus. • Optimized imaging conditions enable multicolor super-resolution imaging.« less

Carbonate crystals precipitated by freshwater bacteria and their use as a limestone consolidant.

PubMed

Zamarreño, Dania V; Inkpen, Robert; May, Eric

2009-09-01

Bacterial carbonate precipitation is known to be a natural phenomenon associated with a wide range of bacterial species. Recently, the ability of bacteria to produce carbonates has been studied for its value in the conservation of limestone monuments and concrete. This paper describes investigations of carbonate crystals precipitated by freshwater bacteria by means of histological (Loeffler's methylene blue and alcian blue-periodic acid-Schiff stain) and fluorescence (CTC [5-cyano-2,3-ditolyl tetrazolium chloride]) stains, determination of cell viability inside carbonate crystals, and pore size reduction in limestone by image analysis. Carbonate crystals were found to be composed of bacteria embedded in a matrix of neutral and acid polysaccharides. Cell viability inside the carbonate crystals decreased with time. On stone, bacteria were found to form carbonate crystals, with only a few bacteria remaining as isolated cells or as cell aggregates. Pore size was reduced by about 50%, but no blockage was detected. Taken together, the results of this research provide some reassurance to conservators that biocalcification by bacteria could be a safe consolidation tool in a restoration strategy for building stone conservation.

Carbonate Crystals Precipitated by Freshwater Bacteria and Their Use as a Limestone Consolidant▿

PubMed Central

Zamarreño, Dania V.; Inkpen, Robert; May, Eric

2009-01-01

Bacterial carbonate precipitation is known to be a natural phenomenon associated with a wide range of bacterial species. Recently, the ability of bacteria to produce carbonates has been studied for its value in the conservation of limestone monuments and concrete. This paper describes investigations of carbonate crystals precipitated by freshwater bacteria by means of histological (Loeffler's methylene blue and alcian blue-periodic acid-Schiff stain) and fluorescence (CTC [5-cyano-2,3-ditolyl tetrazolium chloride]) stains, determination of cell viability inside carbonate crystals, and pore size reduction in limestone by image analysis. Carbonate crystals were found to be composed of bacteria embedded in a matrix of neutral and acid polysaccharides. Cell viability inside the carbonate crystals decreased with time. On stone, bacteria were found to form carbonate crystals, with only a few bacteria remaining as isolated cells or as cell aggregates. Pore size was reduced by about 50%, but no blockage was detected. Taken together, the results of this research provide some reassurance to conservators that biocalcification by bacteria could be a safe consolidation tool in a restoration strategy for building stone conservation. PMID:19617383

Gram and acridine orange staining for diagnosis of septic arthritis in different patient populations.

PubMed

Cunningham, Gregory; Seghrouchni, Khalid; Ruffieux, Etienne; Vaudaux, Pierre; Gayet-Ageron, Angèle; Cherkaoui, Abdessalam; Godinho, Eduardo; Lew, Daniel; Hoffmeyer, Pierre; Uçkay, Ilker

2014-06-01

The sensitivity of Gram staining is known to be suboptimal for the diagnosis of native joint septic arthritis. We lack information about the accuracy of Gram compared to other microscopic staining techniques for predicting infection in different patient populations. This was a cohort study with cost evaluations at the Orthopaedic Service of Geneva University Hospitals (January 1996-October 2012). Among 500 episodes of arthritis (196 with immunosuppression, 227 with underlying arthroplasties and 69 with gout or other crystals in synovial fluid), Gram staining revealed pathogens in 146 episodes (146/500, 29 %) or in 146 of the 400 culture-positive episodes (37 %). Correlation between the Gram and acridine staining of the same sample was good (Spearman 0.85). Overall, the sensitivity, specificity, positive predictive value and negative predictive value of Gram stain for rapid diagnosis of septic arthritis was 0.37, 0.99, 0.99 and 0.28, respectively, compared to microbiological cultures. Quite similar values were recorded across the different patient subpopulations, in particular for sensitivity values that were 0.33 for patients with prosthetic joint infections, 0.40 for immunosuppressed patients, 0.36 for patients under antibiotic administration and 0.52 for patients with concomitant crystalline disease. The sensitivity of Gram or acridine orange staining for a rapid diagnosis of episodes of septic arthritis is suboptimal compared to microbiological culture, regardless of underlying conditions, immunosuppression or antibiotic therapy. The sensitivity in the presence of synovial fluid crystals is moderate. Acridine orange and Gram stains are equivalent.

Preparation of Calcined Zirconia-Carbon Composite from Metal Organic Frameworks and Its Application to Adsorption of Crystal Violet and Salicylic Acid

PubMed Central

Hasan, Zubair; Cho, Dong-Wan; Nam, In-Hyun; Chon, Chul-Min; Song, Hocheol

2016-01-01

Zirconia-carbon (ZC) composites were prepared via calcination of Zr-based metal organic frameworks, UiO-66 and amino-functionalized UiO-66, under N2 atmosphere. The prepared composites were characterized using a series of instrumental analyses. The surface area of the ZC composites increased with the increase of calcination temperature, with the formation of a graphite oxide phase observed at 900 °C. The composites were used for adsorptive removal of a dye (crystal violet, CV) and a pharmaceutical and personal care product (salicylic acid, SA). The increase of the calcination temperature resulted in enhanced adsorption capability of the composites toward CV. The composite calcined at 900 °C exhibited a maximum uptake of 243 mg·g−1, which was much greater than that by a commercial activated carbon. The composite was also effective in SA adsorption (102 mg·g−1), and N-functionalization of the composite further enhanced its adsorption capability (109 mg·g−1). CV adsorption was weakly influenced by solution pH, but was more dependent on the surface area and pore volume of the ZC composite. Meanwhile, SA adsorption showed strong pH dependence, which implies an active role of electrostatic interactions in the adsorption process. Base-base repulsion and hydrogen bonding are also suggested to influence the adsorption of CV and SA, especially for the N-functionalized composite. PMID:28773387

Removal of Crystal Violet by Using Reduced-Graphene-Oxide-Supported Bimetallic Fe/Ni Nanoparticles (rGO/Fe/Ni): Application of Artificial Intelligence Modeling for the Optimization Process

PubMed Central

Ruan, Wenqian; Qi, Jimei; Hou, Yu; Cao, Rensheng; Wei, Xionghui

2018-01-01

Reduced-graphene-oxide-supported bimetallic Fe/Ni nanoparticles were synthesized in this study for the removal of crystal violet (CV) dye from aqueous solutions. This material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), Raman spectroscopy, N2-sorption, and X-ray photoelectron spectroscopy (XPS). The influence of independent parameters (namely, initial dye concentration, initial pH, contact time, and temperature) on the removal efficiency were investigated via Box–Behnken design (BBD). Artificial intelligence (i.e., artificial neural network, genetic algorithm, and particle swarm optimization) was used to optimize and predict the optimum conditions and obtain the maximum removal efficiency. The zero point of charge (pHZPC) of rGO/Fe/Ni composites was determined by using the salt addition method. The experimental equilibrium data were fitted well to the Freundlich model for the evaluation of the actual behavior of CV adsorption, and the maximum adsorption capacity was estimated as 2000.00 mg/g. The kinetic study discloses that the adsorption processes can be satisfactorily described by the pseudo-second-order model. The values of Gibbs free energy change (ΔG0), entropy change (ΔS0), and enthalpy change (ΔH0) demonstrate the spontaneous and endothermic nature of the adsorption of CV onto rGO/Fe/Ni composites. PMID:29789483

Efficient removal of crystal violet using Fe3O4-coated biochar: the role of the Fe3O4 nanoparticles and modeling study their adsorption behavior

NASA Astrophysics Data System (ADS)

Sun, Pengfei; Hui, Cai; Azim Khan, Rashid; Du, Jingting; Zhang, Qichun; Zhao, Yu-Hua

2015-07-01

Biochar shows great promise for use in adsorbing pollutants. However, a process for enhancing its adsorption capacity and re-collection efficiency is yet to be further developed. Hence, in this study, we developed a type of biochar coated with magnetic Fe3O4 nanoparticles (i.e., magnetic biochar (MBC)) and assessed its use for crystal violet (CV) adsorption as well as its recycling potential. The coating of Fe3O4 nanoparticles, which was not only on the surface, but also in the interior of biochar, performed two functions. Firstly, it produced a saturation magnetization of 61.48 emu/g, which enabled the biochar being efficiently re-collected using a magnet. Secondly, it significantly enhanced the adsorption capacity of the biochar (from 80.36 to 99.19 mg/g). The adsorption capacity of the MBC was determined to be the largest by so far (349.40 mg/g) for an initial CV concentration of 400 mg/L, pH of 6.0, and temperature of 40 °C, and the adsorption capacity of re-collected MBC was 73.31 mg/g. The adsorption of CV by the MBC was found to be a spontaneous and endothermic physical process in which the intraparticle diffusion was the limiting step. These findings inspire us to use other similar materials to tackle the menace of pollutions.

Evaluation of the individuality of white rot macro fungus for the decolorization of synthetic dye.

PubMed

Pandey, Priyanka; Singh, Ram Praksh; Singh, Kailash Nath; Manisankar, Paramasivam

2013-01-01

A biosorbent was developed by simple dried Agaricus bisporus (SDAB) and effectively used for the biosorption of cationic dyes, Crystal Violet and Brilliant Green. For the evaluation of the biosorbent system, all the batch equilibrium parameters like pH, biomass dose, contact time, and temperature were optimized to determine the decolorization efficiency of the biosorbent. The maximum yields of dye removal were achieved at pH 4.0 for Crystal Violet (CV) and pH 5.0 for Brilliant Green (BG), which are closer to their natural pH also. Equilibrium was established at 60 and 40 min for CV and BG, respectively. Pseudo first-order, pseudo second-order, and intraparticle-diffusion kinetic models were studied at different temperatures. Isotherm models such as Freundlich, Langmuir, and Dubinin-Radushkevich were also studied. Biosorption processes were successfully described by Langmuir isotherm model and the pseudo second-order kinetic model. The biosorption capacity of A. bisporus over CV and BG were found as 21.74 and 12.16 mg gm(-1). Thermodynamic parameters indicated that the CV and BG dye adsorption onto A. bisporus is spontaneous and exothermic in the single and ternary systems. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used for the surface morphology, crystalline structure of biosorbent, and dye-biosorbent interaction, respectively. This analysis of the biosorption data confirmed that these biosorption processes are ecofriendly and economical. Thus, this biomass system may be useful for the removal of contaminating cationic dyes.

White Light-Activated Antimicrobial Paint using Crystal Violet.

PubMed

Hwang, Gi Byoung; Allan, Elaine; Parkin, Ivan P

2016-06-22

Crystal violet (CV) was incorporated into acrylic latex to produce white-light-activated antimicrobial paint (WLAAP). Measurement of the water contact angle of the WLAAP showed that the water contact angle increased with increasing CV concentration. In a leaching test over 120 h, the amount of CV that leached from the WLAAPs was close to the detection limit (<0.03%). The WLAAPs were used to coat samples of polyurethane, and these showed bactericidal activity against Escherichia coli, which is a key causative agent of healthcare-associated infections (HAIs). A reduction in the numbers of viable bacteria was observed on the painted coated polyurethane after 6 h in the dark, and the bactericidal activity increased with increasing CV concentration (P < 0.1). After 6 h of white light exposure, all of coated polyurethanes demonstrated a potent photobactericidal activity, and it was statistically confirmed that the WLAAP showed better activity in white light than in the dark (P < 0.05). At the highest CV concentration, the numbers of viable bacteria fell below the detection limit (<10(3) CFU/mL) after 6 h of white light exposure. The difference in antimicrobial activity between the materials in the light and dark was 0.48 log at CV 250 ppm, and it increased by 0.43 log at each increment of CV 250 ppm. The difference was the highest (>1.8 log) at the highest CV concentration (1000 ppm). These WLAAPs are promising candidates for use in healthcare facilities to reduce HAIs.

Controlling silk fibroin particle features for drug delivery

PubMed Central

Lammel, Andreas; Hu, Xiao; Park, Sang-Hyug; Kaplan, David L.; Scheibel, Thomas

2010-01-01

Silk proteins are a promising material for drug delivery due to their aqueous processability, biocompatibility, and biodegradability. A simple aqueous preparation method for silk fibroin particles with controllable size, secondary structure and zeta potential is reported. The particles were produced by salting out a silk fibroin solution with potassium phosphate. The effect of ionic strength and pH of potassium phosphate solution on the yield and morphology of the particles was determined. Secondary structure and zeta potential of the silk particles could be controlled by pH. Particles produced by salting out with 1.25 M potassium phosphate pH 6 showed a dominating silk II (crystalline) structure whereas particles produced at pH 9 were mainly composed of silk I (less crystalline). The results show that silk I rich particles possess chemical and physical stability and secondary structure which remained unchanged during post treatments even upon exposure to 100% ethanol or methanol. A model is presented to explain the process of particle formation based on intra- and intermolecular interactions of the silk domains, influenced by pH and kosmotrope salts. The reported silk fibroin particles can be loaded with small molecule model drugs, such as alcian blue, rhodamine B, and crystal violet, by simple absorption based on electrostatic interactions. In vitro release of these compounds from the silk particles depends on charge – charge interactions between the compounds and the silk. With crystal violet we demonstrated that the release kinetics are dependent on the secondary structure of the particles. PMID:20219241

Three-dimensional polylactic acid@graphene oxide/chitosan sponge bionic filter: Highly efficient adsorption of crystal violet dye.

PubMed

Zhou, G; Wang, K P; Liu, H W; Wang, L; Xiao, X F; Dou, D D; Fan, Y B

2018-07-01

Owing to low bearing capacity and efficiency, traditional filters or adsorbents for removal of contaminants like crystal violet (CV) dye required frequent replacement. Besides, the combination of three-dimensional (3D) printing and bionics could break the constraints of traditional configuration. In this study, a novel depth-type hybrid polylactic acid (PLA)@graphene oxide (GO)/chitosan (CS) sponge filter with bionic fish-mouth structure was prepared and fabricated, assisted by 3D printing and double freeze-drying technology, according to the theories of vertical cross-step filtration and swirling flow. And GO/CS sponge and its filtering device were characterized by FITR, SEM, water adsorption and so on. Moreover, it was explained that the impact factors on dye removal mechanism, like GO content (or CS content), contact time, pH, temperature and bionic configuration. As a result, the bionic 3D filtering device demonstrated excellent removal efficiency (97.8±0.5% for CV) and GO/CS sponge exhibited higher strength (74.5±3.5MPa) at the condition of GO content of 9wt%, contact time of 46min, pH of 8 and 35°C, respectively. Therefore, the resulting 3D PLA@GO/CS sponge bionic filter via gravity and vortex driving provided new alternatives for effectively dye-water separation, and it showed great promise for application of biological macromolecules in adsorption. Copyright © 2018 Elsevier B.V. All rights reserved.

Degradation of crystal violet by an FeGAC/H2O2 process.

PubMed

Chen, Chiing-Chang; Chen, Wen-Ching; Chiou, Mei-Rung; Chen, Sheng-Wei; Chen, Yao Yin; Fan, Huan-Jung

2011-11-30

Because of the growing concern over highly contaminated crystal violet (CV) wastewater, an FeGAC/H(2)O(2) process was employed in this research to treat CV-contaminated wastewater. The experimental results indicated that the presence of iron oxide-coated granular activated carbon (FeGAC) greatly improved the oxidative ability of H(2)O(2) for the removal of CV. For instance, the removal efficiencies of H(2)O(2), GAC, FeGAC, GAC/H(2)O(2) and FeGAC/H(2)O(2) processes were 10%, 44%, 40%, 43% and 71%, respectively, at test conditions of pH 3 and 7.4mM H(2)O(2). FeGAC/H(2)O(2) combined both the advantages of FeGAC and H(2)O(2). FeGAC had a good CV adsorption ability and could effectively catalyze the hydrogen peroxide oxidation reaction. Factors (including pH, FeGAC dosage and H(2)O(2) dosage) affecting the removal of CV by FeGAC/H(2)O(2) were investigated in this research as well. In addition, the reaction intermediates were separated and identified using HPLC-ESI-MS. The N-demethylation step might be the main reaction pathway for the removal of CV. The reaction mechanisms for the process proposed in this research might be useful for future application of this technology to the removal of triphenylmethane (TPM) dyes. Copyright © 2011 Elsevier B.V. All rights reserved.

The efficient n-doping of [6,6]-phenyl C61-butyric acid methyl ester by leuco-crystal violet to enhance the performance of inverted organic solar cells

NASA Astrophysics Data System (ADS)

Chen, Li; Zhao, Wei; Cao, Huan; Shi, Zhihua; Zhang, Jidong; Qin, Dashan

2018-02-01

Inverted organic solar cells (OSCs) have been fabricated using the photoactive blend thin films based on regioregular poly(3-hexylthiophene) (P3HT), [6,6]-phenyl C61-butyric acid methyl ester (PCBM), and leuco-crystal violet (LCV). It was found that the LCV as an efficient n-dopant could significantly increase intrinsic electron concentration of PCBM zone. The electron mobility of P3HT:PCBM:LCV blend thin film was measured 1.75 times as high as that of P3HT:PCBM blend thin film, as a result of LCV-induced trap filling in the bandgap of PCBM. The power conversion efficiency for the inverted device using the photoactive layer of P3HT:PCBM:LCV could be 1.22 times as high as that for the inverted device using the conventional photoactive layer of P3HT:PCBM, mostly because (1) the higher electron mobility could enhance the exciton dissociation and thereby short-circuit current density in the former relative to the latter; (2) the increase in the electron concentration of PCBM zone in P3HT:PCBM:LCV blend thin film may help blocking holes diffusion towards cathode, improving the hole collection efficiency and thereby fill factor of device. We provide a new insight on optimizing the electron-conducting property of bulk-heterojunction photoactive thin film, useful for pushing forward inverted OSCs towards the cost-effective commercialization.

Neurohistochemical biomarkers of the marine neurotoxicant, domoic acid.

PubMed

Scallet, Andrew C; Schmued, Larry C; Johannessen, Jan N

2005-01-01

Domoic acid and its potent excitotoxic analogues glutamic acid and kainic acid, are synthesized by marine algae such as seaweed and phytoplankton. During an algal bloom, domoic acid may enter the food web through its consumption by a variety of marine organisms held in high regard as seafoods by both animals and humans. These seafoods include clams, mussels, oysters, anchovies, sardines, crabs, and scallops, among others. Animals, such as pelicans, cormorants, loons, grebes, sea otters, dolphins, and sea lions, which consume seafood contaminated with domoic acid, suffer disorientation and often death. Humans consuming contaminated seafood may suffer seizures, amnesia and also sometimes death. In addition to analytical measurement of domoic acid exposure levels in algae and/or seafood, it is useful to be able to identify the mode of toxicity through post-mortem evaluation of the intoxicated animal. In the present study, using the rat as an animal model of domoic acid intoxication, we compared histochemical staining of the limbic system and especially the hippocampus with degeneration-selective techniques (Fluoro-Jade and silver), a conventional Nissl stain for cytoplasm (Cresyl violet), a myelin-selective stain (Black-Gold), an astrocyte-specific stain (glial fibrillary acidic protein), early/immediate gene responses (c-Fos and c-Jun), as well as for heat shock protein (HSP-72) and blood-brain barrier integrity (rat IgG). The results demonstrate that the degeneration-selective stains are the biomarkers of domoic acid neurotoxicity that are the most useful and easy to discern when screening brain sections at low magnification. We also observed that an impairment of blood-brain barrier integrity within the piriform cortex accompanied the onset of domoic acid neurotoxicity.

Luminescence properties of ZnxMg1-xSe layers

NASA Astrophysics Data System (ADS)

Bala, Waclaw; Firszt, Franciszek; Dzik, Janusz; Gapinski, Adam; Glowacki, Grzegorz

1995-10-01

This work deals with the study of luminescence properties of ZnxMg1-xSe layers prepared by different methods. ZnxMg1-xSe mixed crystal layers were obtained by: (a) thermal diffusion of Mg metal in the temperature range 1050 K - 1200 K into ZnSe single crystal grown by Bridgman method, and (b) epitaxial growth on (001) GaAs and (111) ZnTe substrates by MBE using elemental Zn, Se and Mg sources. The luminescence spectra of ZnxMg1-xSe layers grown on (001) GaAs and (111) ZnTe substrates are dominated by narrow blue and violet emission bands with maxima positioned at about 3.05 - 3.28 eV, 2.88 - 3.04 eV, and 2.81 - 2.705 eV.

Luminescent properties of Cr-doped (GdX, Y1-X)3Al5O12 infra-red scintillator crystals

NASA Astrophysics Data System (ADS)

Suzuki, Akira; Kurosawa, Shunsuke; Yamaji, Akihiro; Shoji, Yasuhiro; Pejchal, Jan; Kamada, Kei; Yokota, Yuui; Yoshikawa, Akira

2014-10-01

Cr-doped (GdX Y1-X)3Al5O12 (X = 0, 0.25, 0.50) crystals prepared by the micro-pulling down method were investigated to develop a infra-red scintillator for implantable patient dosimeter in radiation therapy. In order to evaluate their optical and scintillation performance, the following properties were measured: (i) transmittance between ultra-violet and near-infra red region, (ii) photoluminescence spectra under Xe-lamp excitation, and (iii) X-ray excited radio-luminescence spectra. Cr:Y3Al5O12 and Cr:(Gd0.25 Y0.75)3Al5O12 crystals showed increased transmittance of 80%, while Cr:(Gd0.50 Y0.50)3Al5O12 had a lower transmittance of 40% due to its polycrystalline structure. In addition, all the Cr:(GdX Y1-X)3Al5O12 crystals showed sharp scintillation luminescence peaks ascribed to Cr3+ d-d transitions. Therefore, these results suggested that Cr:Y3Al5O12 and Cr:(Gd0.25 Y0.75)3Al5O12 crystals can be candidate materials for the dosimeter use.

Gastrodia and Uncaria (tianma gouteng) water extract exerts antioxidative and antiapoptotic effects against cerebral ischemia in vitro and in vivo.

PubMed

Xian, Jia Wen; Choi, Angus Yiu-Ting; Lau, Clara Bik-San; Leung, Wing Nang; Ng, Chun Fai; Chan, Chun Wai

2016-01-01

Gastrodia and Uncaria decoction (tianma gouteng yin) is commonly used in Chinese medicine to treat cerebral ischemia. The aim of this study was to investigate the neuroprotective effects of a water extract (GUW) of Gastrodia elata (tianma; GE) and Uncaria rhynchophylla (gouteng; UR) against ischemic insult using oxygen-glucose-deprived neuronal differentiated PC12 cells and rats subjected to middle cerebral artery occlusion (MCAO). GUW was prepared by boiling raw GE and UR in water, followed by the lyophilization of the resulting extract. Neuronal differentiated PC12 cells were subjected to oxygen-glucose deprivation with or without GUW. The neuroprotective effects of GUW were compared with those of the corresponding GE and UR extracts to tease apart the effects of the different herbs. The synergistic effect of GE and UR in GUW was measured using a modified version of Burgi's formulae. The neuroprotective mechanisms via Nrf2 and anti-apoptotic pathways were investigated using real time PCR and enzyme activity assays. The neuroprotective effects of GUW were studied in vivo using a rat MCAO model. Neurofunctional outcome and brain infarct volume we assessed. H&E staining, cresyl violet staining and immunohistochemistry were performed to assess the histological outcome. The results of lactate dehydrogenase assay showed that GUW protected cells in a concentration-dependent manner (P < 0.001). Moreover, the neuroprotective effects of GUW were greater than those of GE + UR (P = 0.018). Burgi's formula showed that the herbs in GUW acted synergistically to protect cells from ischemic injury. GUW significantly upregulated Bcl-2 expression (P = 0.0130) and reduced caspase-3 activity by 60 % (P < 0.001). GUW upregulated Nrf-2 expression (P = 0.0066) and the antioxidant response element pathway genes. The infarct volume was reduced by 55 % at day 7 of reperfusion (P < 0.001), and significant improvements were observed in the neurological deficit score and beam-walking test at 7 days (P < 0.001). H&E and cresyl violet staining revealed higher tissue integrity in the GUW treatment group compared with MCAO rats. GUW modulated the antioxidant system and antiapoptotic genes in oxygen-glucose deprived neuronal differentiated PC12 cells and MCAO sprague-dawley rats.

From Serendipity to Rational Design: Tuning the Blue Trigonal Bipyramidal Mn3+ Chromophore to Violet and Purple through Application of Chemical Pressure.

PubMed

Li, Jun; Lorger, Simon; Stalick, Judith K; Sleight, Arthur W; Subramanian, M A

2016-10-03

We recently reported that an allowed d-d transition of trigonal bipyramidal (TBP) Mn 3+ is responsible for the bright blue color in the YIn 1-x Mn x O 3 solid solution. The crystal field splitting between a'(d z 2 ) and e'(d x 2 -y 2 , d xy ) energy levels is very sensitive to the apical Mn-O distance. We therefore applied chemical pressure to compress the apical Mn-O distance in YIn 1-x Mn x O 3 , move the allowed d-d transition to higher energy, and thereby tune the color from blue to violet/purple. This was accomplished by substituting smaller cations such as Ti 4+ /Zn 2+ and Al 3+ onto the TBP In/Mn site, which yielded novel violet/purple phases. The general formula is YIn 1-x-2y-z Mn x Ti y Zn y Al z O 3 (x = 0.005-0.2, y = 0.1-0.4, and z ≤ 0.1), where the color darkens with the increasing amount of Mn. Higher y or small additions of Al provide a more reddish hue to the resulting purple colors. Substituting other rare earth cations for Y has little impact on color. Crystal structure analysis by neutron powder diffraction confirms a shorter apical Mn-O distance compared with that in the blue YIn 1-x Mn x O 3 . Magnetic susceptibility measurements verify the 3+ oxidation state for Mn. Diffuse reflection spectra were obtained over the wavelength region 200-2500 nm. All samples show excellent near-infrared reflectance comparable to that of commercial TiO 2 , making them ideal for cool pigment applications such as energy efficient roofs of buildings and cars where reducing solar heat to save energy is desired. In a comparison with commercial purple pigments, such as Co 3 (PO 4 ) 2 , our pigments are much more thermally stable and chemically inert, and are neither toxic nor carcinogenic.

Biosynthesis of Enterobacterial Common Antigen: The ECA-Trace Phenotype of Salmonella Typhimurium and The Role of the rfe Gene in 08 Side-Chain Synthesis in Escherichia Coli

DTIC Science & Technology

1993-03-18

malachite green, 2mg/ml; erythromycin, 2mg/ml; bacitracin, 20mg/ml; streptomycin, 50mg/ml; crystal violet, 100mg/ml; novobiocin, Smg/ml; rifamycin...cephalosporin C, ISug/ml; actinomycin D, 37Sug/ml; kanamycin, S.6ug/ml; chlorotetracycline, 3.8ug/ml; vancomycin, 900ug/ml; malachite green, 60ug...carbenicillin; Ceph, cephalosporin C; AcID, actinomycin D; ((an, kanamycin; Ctet, chlorotetracycline; Van, vancomycin; MalG, malachite green; Eryth

Study of Nanodispersed Iron Oxides Produced in Steel Drilling by Contracted Electric-Arc Air Plasma Torch

NASA Astrophysics Data System (ADS)

Stefanov, P.; Galanov, D.; Vissokov, G.; Paneva, D.; Kunev, B.; Mitov, I.

2008-06-01

The optimal conditions on the plasma-forming gas flowrate, discharge current and voltage, distance between the plasma-torch nozzle and the metal plate surface for the process of penetration in and vaporization of steel plates by the contracted electric-arc air plasma torch accompanied by water quenching, were determined. The X-ray structural and phase studies as well as Mössbauer and electron microscope studies on the samples treated were performed. It was demonstrated that the vaporized elemental iron was oxidized by the oxygen present in the air plasma jet to form iron oxides (wüstite, magnetite, hematite), which, depending on their mass ratios, determined the color of the iron oxide pigments, namely, beginning from light yellow, through deep yellow, light brown, deep brown, violet, red-violet, to black. A high degree of dispersity of the iron oxides is thus produced, with an averaged diameter of the particles below 500 nm, and their defective crystal structure form the basis of their potential application as components of iron-containing catalysts and pigments.

Hydrothermal growth of n-ZnO films on a patterned p-GaN epilayer and its application in heterojunction light-emitting diodes

NASA Astrophysics Data System (ADS)

Ko, Rong-Ming; Wang, Shui-Jinn; Chen, Ching-Yi; Wu, Cheng-Han; Lin, Yan-Ru; Lo, Hsin-Ming

2017-04-01

The hydrothermal growth (HTG) of crystalline n-ZnO films on both the nonpatterned and patterned p-GaN epilayers with a honeycomb array of etched holes is demonstrated, and its application in n-ZnO/p-GaN heterojunction light-emitting diodes (HJ-LEDs) is reported. The results reveal that an HTG n-ZnO film on a patterned p-GaN layer exhibits a high-quality single crystal with FWHMs of 0.463 and 0.983° obtained from a ω-rocking curve and a ϕ-scan pattern, respectively, which are much better than those obtained on a nonpatterned p-GaN layer. In addition, the n-ZnO/patterned p-GaN HJ-LED exhibited a much better rectifying diode behavior owing to having a higher n-ZnO film crystallinity quality and an improved interface with the p-GaN layer. Strong violet and violet-blue lights emitted from the n-ZnO/patterned p-GaN HJ-LED at around 405, 412, and 430 nm were analyzed.

A strategic approach to physico-chemical analysis of bis (thiourea) lead chloride - A reliable semi-organic nonlinear optical crystal

NASA Astrophysics Data System (ADS)

Rajagopalan, N. R.; Krishnamoorthy, P.; Jayamoorthy, K.

2017-03-01

Good quality crystals of bis thiourea lead chloride (BTLC) have been grown by slow evaporation method from aqueous solution. Orthorhombic structure and Pna21 space group of the crystals have been identified by single crystal X-ray diffraction. Studies on nucleation kinetics of grown BTLC has been carried out from which meta-stable zone width, induction period, free energy change, critical radius, critical number and growth rate have been calculated. The experimental values of interfacial surface energy for the crystal growth process have been compared with theoretical models. Ultra violet transmittance studies resulted in a high transmittance and wide band gap energy suggested the required optical transparency of the crystal. The second harmonic generation (SHG) and phase matching nature of the crystal have been justified by Kurtz-Perry method. The SHG nature of the crystal has been further attested by the higher values of theoretical hyper polarizability. The dielectric nature of the crystals at different temperatures with varying frequencies has been thoroughly studied. The activation energy values of the electrical process have been calculated from ac conductivity study. Solid state parameters including valence electron plasma energy, Penn gap, Fermi energy and polarisability have been unveiled by theoretical approach and correlated with the crystal's SHG efficiency. The values of hardness number, elastic stiffness constant, Meyer's Index, minimum level of indentation load, load dependent constant, fracture toughness, brittleness index and corrected hardness obtained from Vicker's hardness test clearly showed that the BTLC crystal has good mechanical stability required for NLO device fabrication.

The impact of cellular debris on Pseudomonas aeruginosa adherence to silicone hydrogel contact lenses and contact lens storage cases.

PubMed

Burnham, Geoffrey W; Cavanagh, H Dwight; Robertson, Danielle M

2012-01-01

To evaluate neutrophil-enhanced Pseudomonas aeruginosa (PA) biofilm formation on silicone hydrogel contact lenses and to determine the effect of epithelial biodebris on PA adherence in contact lens storage cases. A fully invasive PA corneal isolate stably conjugated to green fluorescent protein was used. Unworn lotrafilcon A contact lenses were incubated at various ratios of PA to polymorphonuclear neutrophil (PMN) for 24 hours at 37°C. Lens-associated PA was evaluated using laser scanning confocal microscopy and nonviable PA were visualized using propidium iodide. Viable bacteria were enumerated by colony-forming unit (CFU) analysis. For acute epithelial cell studies, PA viability was determined after coincubation with freeze-thaw epithelial cell lysates in 96-well polystyrene plates. Levels of residual cellular debris and bacterial viability were further assessed in used contact lens storage cases. Laser scanning confocal microscopy demonstrated that cotreatment with PMA-stimulated neutrophils increased PA adherence over 24 hours to lens surfaces with a striking alteration of PA architecture. Propidium iodide staining showed that the adherent bacteria consisted of a mixture of viable and nonviable PA; a PMN-associated increase in viable PA was confirmed by CFU (PA:PMN 0.1:1, P = 0.025; PA:PMN 1:1, P = 0.005). Acute epithelial cell debris studies revealed a significant increase in viable PA in 96-well plates in the presence of epithelial freeze-thaw lysates (PA:debris 1:1, P = 0.002; PA:debris 100:1, P = 0.002). Crystal violet staining of used lens storage cases revealed residual cellular debris at all time points, which was independent of microbial contamination; all lens cases used for periods of 9 months or more were uniformly associated with high levels of viable microorganisms. These results demonstrate that prolonged corneal inflammation with the presence of PMNs when confronted with simultaneous PA challenge in extended contact lens wear has the potential to stimulate biofilm formation on silicone hydrogel contact lenses. These findings further suggest that a persistent buildup of extracellular debris in lens storage cases may contribute to the heavy biofilms reported on these surfaces.

Do the presence of Barr bodies in male jail inmates indicates criminality: A pilot study.

PubMed

Kulkarni, Mayuri K; Somannavar, Pradeep D; Kotrashetti, Vijayalakshmi; Nayak, Ramakant; Hosmani, Jagadish; Babji, Deepa

2016-01-01

Cytogenetic studies from past decades have shown that interphase cells of female cats contain a densely stained chromatin mass in their nuclei called as Barr bodies (BBs) named after the scientist Murray Barr. BBs are unique chromatin structures formed due to the condensation of the X-chromosome. Many psychopathic disorders originate from defective genes including the multiple X syndromes. Males with extra X-chromosome generally present with severe personality disorder. The present study was conducted to determine the presence of extra X-chromosome in male jail inmates through the detection of BB in peripheral blood and buccal smear. Study included 100 male subjects (fifty jail inmates and fifty controls), after obtaining the consent, peripheral blood smears (PBS) and buccal smears (BS) were prepared and stained using Leishman's and cresyl violet stain respectively. One hundred neutrophils in PBS and epithelial cells in BS were screened for detection of the BB; accumulated data were tabulated and statistically analyzed using t-test and Chi-square test. 60% of cases in PBS and 36% in BS showed positivity for the presence of BB in jail inmates as compared to 14% of cases in PBS and none in BS were positive for BB in controls. Presence of BB in male suggests increased likelihood of criminal tendencies. Further studies are to be carried out to compare the results with karyotyping.

Time-resolved, single-cell analysis of induced and programmed cell death via non-invasive propidium iodide and counterstain perfusion.

PubMed

Krämer, Christina E M; Wiechert, Wolfgang; Kohlheyer, Dietrich

2016-09-01

Conventional propidium iodide (PI) staining requires the execution of multiple steps prior to analysis, potentially affecting assay results as well as cell vitality. In this study, this multistep analysis method has been transformed into a single-step, non-toxic, real-time method via live-cell imaging during perfusion with 0.1 μM PI inside a microfluidic cultivation device. Dynamic PI staining was an effective live/dead analytical tool and demonstrated consistent results for single-cell death initiated by direct or indirect triggers. Application of this method for the first time revealed the apparent antibiotic tolerance of wild-type Corynebacterium glutamicum cells, as indicated by the conversion of violet fluorogenic calcein acetoxymethyl ester (CvAM). Additional implementation of this method provided insight into the induced cell lysis of Escherichia coli cells expressing a lytic toxin-antitoxin module, providing evidence for non-lytic cell death and cell resistance to toxin production. Finally, our dynamic PI staining method distinguished necrotic-like and apoptotic-like cell death phenotypes in Saccharomyces cerevisiae among predisposed descendants of nutrient-deprived ancestor cells using PO-PRO-1 or green fluorogenic calcein acetoxymethyl ester (CgAM) as counterstains. The combination of single-cell cultivation, fluorescent time-lapse imaging, and PI perfusion facilitates spatiotemporally resolved observations that deliver new insights into the dynamics of cellular behaviour.

Do the presence of Barr bodies in male jail inmates indicates criminality: A pilot study

PubMed Central

Kulkarni, Mayuri K; Somannavar, Pradeep D; Kotrashetti, Vijayalakshmi; Nayak, Ramakant; Hosmani, Jagadish; Babji, Deepa

2016-01-01

Background: Cytogenetic studies from past decades have shown that interphase cells of female cats contain a densely stained chromatin mass in their nuclei called as Barr bodies (BBs) named after the scientist Murray Barr. BBs are unique chromatin structures formed due to the condensation of the X-chromosome. Many psychopathic disorders originate from defective genes including the multiple X syndromes. Males with extra X-chromosome generally present with severe personality disorder. The present study was conducted to determine the presence of extra X-chromosome in male jail inmates through the detection of BB in peripheral blood and buccal smear. Materials and Methods: Study included 100 male subjects (fifty jail inmates and fifty controls), after obtaining the consent, peripheral blood smears (PBS) and buccal smears (BS) were prepared and stained using Leishman's and cresyl violet stain respectively. One hundred neutrophils in PBS and epithelial cells in BS were screened for detection of the BB; accumulated data were tabulated and statistically analyzed using t-test and Chi-square test. Results: 60% of cases in PBS and 36% in BS showed positivity for the presence of BB in jail inmates as compared to 14% of cases in PBS and none in BS were positive for BB in controls. Conclusion: Presence of BB in male suggests increased likelihood of criminal tendencies. Further studies are to be carried out to compare the results with karyotyping. PMID:27194855

Biofilm Formation by Otopathogenic Strains of P. aeruginosa is not Consistently Inhibited by EDTA

PubMed Central

Zenga, Joseph; Gagnon, Patricia M.; Vogel, Joseph; Chole, Richard A.

2012-01-01

Hypothesis Biofilm formation in otopathogenic of P. aeruginosa (OPPA) strains is inhibited by ethylenediaminetetraacetic acid (EDTA). Background EDTA, a widely used chelating agent, has been shown to inhibit biofilm formation in a number of bacteria. Since EDTA may be a well-tolerated reagent to inhibit biofilm formation in cases of suppurative otitis media, we asked if it might be effective in all OPPA strains isolated from chronically infected cholesteatomas. Methods OPPA strains were isolated from patients with infected cholesteatomas. These strains were grown into log phase then were placed in minimal media with varying concentrations of EDTA, and incubated for varying periods. Biofilm production was measured colorimetrically by staining with crystal violet. Results Without added EDTA, most otopathogenic PA exhibited a distinct, but varying, time-course of biofilm formation and dissolution with peak production at 12–18 hours. Addition of 1 mM EDTA resulted in a delay in the time to peak biofilm formation for most strains, although the amount of biofilm was not decreased. In contrast, some strains showed greater biofilm production with 1 mM EDTA compared to the untreated bacteria. Addition of 10 mM EDTA resulted in a similar effect. Some strains increased biofilm production over controls. Moreover, EDTA inhibited planktonic growth of all OPPA strains at the concentrations studied. Conclusion Our hypothesis was disproven: EDTA tends to delay biofilm development while it consistently inhibits planktonic growth. Since EDTA does not cause suppression of biofilm production in all isolates of OPPA, usefulness as an antimicrobial is questioned. PMID:22772018

Prolonged weakening of the geomagnetic field (GMF) affects the immune system of rats.

PubMed

Roman, Adam; Tombarkiewicz, Barbara

2009-01-01

The aim of this study was to find out how a long-term shielding of the geomagnetic field (GMF) affected the immune system of rats. Male and female Wistar rats were kept up to an age of 2 months in a natural GMF (about 37 microT). Afterwards, the rats were divided into four groups (males and females separately): control rats were maintained in ambient GMF, while experimental animals were housed under conditions of a weakened GMF (below 12 microT) achieved with steel cages. After 6 months, the rats were sacrificed by decapitation. Spleens and thymuses were isolated and weighed. Peritoneal cells were eluted and cultured in vitro to study their ability to produce nitric oxide (NO) and to synthesize superoxide anion (O2(-)), important microbicidal molecules of macrophages. The number of macrophages was estimated by a crystal violet staining method. We found that the long-term shielding of the GMF could influence the functioning of the immune system in a sex-dependent manner. The deprivation of the GMF delayed physiological thymus involution, that effect being more strongly expressed in females. The weakening of the GMF resulted in an increased number of peritoneal macrophages, especially in males. The shielding of the GMF diminished the ability of macrophages to release NO and to synthesize O2(-), those effects being more powerfully expressed in males and females, respectively. It is proposed that the observed changes in the immune system occur as a consequence of the protective effect of GMF shielding on the circadian rhythm-dependent level of melatonin. (c) 2008 Wiley-Liss, Inc.

Candida albicans biofilm heterogeneity does not influence denture stomatitis but strongly influences denture cleansing capacity.

PubMed

O'Donnell, Lindsay E; Alalwan, Hasanain K A; Kean, Ryan; Calvert, Gareth; Nile, Christopher J; Lappin, David F; Robertson, Douglas; Williams, Craig; Ramage, Gordon; Sherry, Leighann

2017-01-01

Approximately 20  % of the UK population wear some form of denture prosthesis, resulting in denture stomatitis in half of these individuals. Candida albicans is primarily attributed as the causative agent, due to its biofilm -forming ability. Recently, there has been increasing evidence of C. albicans biofilm heterogeneity and the negative impact it can have clinically; however, this phenomenon has yet to be studied in relation to denture isolates. The aims of this study were to evaluate C. albicans biofilm formation of clinical denture isolates in a denture environment and to assess antimicrobial activity of common denture cleansers against these tenacious communities. C. albicans isolated from dentures of healthy and diseased individuals was quantified using real-time PCR and biofilm biomass assessed using crystal violet. Biofilm development on the denture substratum poly(methyl methacrylate), Molloplast B and Ufi-gel was determined. Biofilm formation was assessed using metabolic and biomass stains, following treatment with denture hygiene products. Although C. albicans was detected in greater quantities in diseased individuals, it was not associated with increased biofilm biomass. Denture substrata were shown to influence biofilm biomass, with poly(methyl methacrylate) providing the most suitable environment for C. albicans to reside. Of all denture hygiene products tested, Milton had the most effective antimicrobial activity, reducing biofilm biomass and viability the greatest. Overall, our results highlight the complex nature of denture- related disease, and disease development cannot always be attributed to a sole cause. It is the distinct combination of various factors that ultimately determines the pathogenic outcome.

Use of a stainless steel washer platform to study Acinetobacter baumannii adhesion and biofilm formation on abiotic surfaces.

PubMed

Orsinger-Jacobsen, Samantha J; Patel, Shenan S; Vellozzi, Ernestine M; Gialanella, Phillip; Nimrichter, Leonardo; Miranda, Kildare; Martinez, Luis R

2013-12-01

Acinetobacter baumannii is a frequent cause of hospital-acquired pneumonia, and has recently increased in incidence as the causative agent of severe disease in troops wounded in Afghanistan and Iraq. Clinical approaches are limited since A. baumannii strains isolated from patients are extremely resistant to current antimicrobials. A. baumannii can survive desiccation and during outbreaks has been recovered from various sites in the patients' environment. To better understand its prevalence in hospital settings, we used a stainless steel washer (SSW) platform to investigate A. baumannii biofilm formation on abiotic surfaces. Scanning electron microscopy demonstrated that A. baumannii forms strong biofilms on stainless steel surfaces. This platform was combined with a colorimetric 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay to observe the metabolic activity of bacterial cells, and to facilitate the manipulation and comparison of multiple A. baumannii clinical strains. A strong correlation between XTT and c.f.u. assays was demonstrated. To complement the cell viability assays, A. baumannii biofilm mass was measured by crystal violet staining. Furthermore, the effect of commonly used disinfectants and environmental stressors on A. baumannii biofilms and planktonic cells was compared and characterized. Biofilms on SSWs were significantly more resistant than their planktonic counterparts, providing additional evidence that may allow us to understand the high prevalence of this microbe in hospital settings. Our results validate that SSWs are a simple, versatile and innovative method to study A. baumannii biofilms in vitro.

Wound healing properties of jojoba liquid wax: an in vitro study.

PubMed

Ranzato, Elia; Martinotti, Simona; Burlando, Bruno

2011-03-24

The wound healing properties of jojoba (Simmondsia chinensis) liquid wax (JLW) were studied in vitro on HaCaT keratinocytes and human dermal fibroblasts, which are involved in wounded skin repair. JLW cytotoxicity was evaluated by the crystal violet staining and the neutral red uptake endpoint. Induction of wound healing by JLW was assessed by scratch wound assay on cell monolayers. The involvement of signaling pathways was evaluated by the use of the Ca(2+) chelator BAPTA and of kinase inhibitors, and by Western blot analysis of cell lysates using anti-phospho antibodies. Collagen and gelatinase secretion by cells were assayed by in-cell ELISA and zymography analysis, respectively. Cytotoxicity assays showed that the toxic effects of JLW to these cells are extremely low. Scratch wound experiments showed that JLW notably accelerates the wound closure of both keratinocytes and fibroblasts. The use of inhibitors and Western blot revealed that the mechanism of action of JLW is strictly Ca(2+) dependent and requires the involvement of the PI3K-Akt-mTOR pathway and of the p38 and ERK1/2 MAPKs. In addition, JLW was found to stimulate collagen I synthesis in fibroblasts, while no effect was detected on the secretion of MMP-2 and MMP-9 gelatinases by HaCaT or fibroblasts. Taken together, data provide a pharmacological characterization of JLW properties on skin cells and suggest that it could be used in the treatment of wounds in clinical settings. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Probiotic yeast Saccharomyces boulardii (nom. nud.) modulates adhesive properties of Candida glabrata.

PubMed

Tomičić, Zorica; Zupan, Jure; Matos, Tadeja; Raspor, Peter

2016-11-01

Following the widespread use of immunosuppressive therapy together with broad-spectrum antimycotic therapy, the frequency of mucosal and systemic infections caused by the pathogenic yeast Candida glabrata has increased in the past decades. Due to the resistance of C. glabrata to existing azole drugs, it is very important to look for new strategies helping the treatment of such fungal diseases. In this study, we investigated the effect of the probiotic yeast Saccharomyces boulardii (nom. nud.) on C. glabrata adhesion at different temperatures, pH values, and in the presence of fluconazole, itraconazole and amphotericin B. We also studied the adhesion of C. glabrata co-culture with Candida krusei, Saccharomyces cerevisiae, two bacterial probiotics Lactobacillus rhamnosus and Lactobacillus casei The method used to assess adhesion was crystal violet staining. Our results showed that despite the nonadhesiveness of S. boulardii cells, this probiotic significantly affected the adherence ability of C. glabrata This effect was highly dependent on C. glabrata strain and was either antagonistic or synergistic. Regarding the extrinsic factors, temperature did not indicate any significant influence on this S. boulardii modulatory effect, while at high pH and at increased concentrations of antimycotics, S. boulardii did not manage to repress the adhesion of C. glabrata strains. The experiments of C. glabrata co-cultures with other species showed that the adhesiveness of two separate cultures could not be used to predict the adhesiveness of their co-culture. © The Author 2016. 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.

Chicken egg yolk antibody (IgY) controls Solobacterium moorei under in vitro and in vivo conditions.

PubMed

Li, Xiaoyu; Liu, He; Xu, Yongping; Xu, Fanxing; Wang, Linhui; You, Jiansong; Li, Shuying; Jin, Liji

2012-11-01

Solobacterium moorei is a causative agent in diseases such as oral halitosis, bacteremia, and necrobacillosis-associated thrombophlebitis. The objective of this study was to determine the effectiveness of chicken egg yolk antibody (IgY) in controlling S. moorei. Intact S. moorei cells were used as an immunogen to immunize four White Leghorn laying hens. IgY, extracted from egg yolks obtained from these immunized hens, was purified using water dilution, two-step salt precipitation, and ultrafiltration. The purity of the IgY obtained was approximately 87.3 %. The antibody titer of the IgY was determined by enzyme-linked immunosorbent assay. The antibody titer peaked at 10,000 following the third immunization. In order to evaluate the inhibitory effects of the specific IgY, the growth of S. moorei in liquid media was measured every 12 h using a microplate reader at 600 nm. Biofilm formation of S. moorei was quantified by staining with crystal violet. The specific binding ability of IgY was further confirmed by the use of immunofluorescence and immunoelectron microscopy. Growth and biofilm formation of S. moorei were significantly (P<0.05) inhibited by 20 and 40 mg/ml specific IgY compared with the control. The specific IgY also decreased the bacterial level in the oral cavity of mice after infection with S. moorei. This study demonstrates that the growth and biofilm formation of S. moorei can be effectively inhibited by specific IgY. As a result, IgY technology may have application in the control of diseases caused by S. moorei.

Use of a stainless steel washer platform to study Acinetobacter baumannii adhesion and biofilm formation on abiotic surfaces

PubMed Central

Orsinger-Jacobsen, Samantha J.; Patel, Shenan S.; Vellozzi, Ernestine M.; Gialanella, Phillip; Nimrichter, Leonardo; Miranda, Kildare

2013-01-01

Acinetobacter baumannii is a frequent cause of hospital-acquired pneumonia, and has recently increased in incidence as the causative agent of severe disease in troops wounded in Afghanistan and Iraq. Clinical approaches are limited since A. baumannii strains isolated from patients are extremely resistant to current antimicrobials. A. baumannii can survive desiccation and during outbreaks has been recovered from various sites in the patients’ environment. To better understand its prevalence in hospital settings, we used a stainless steel washer (SSW) platform to investigate A. baumannii biofilm formation on abiotic surfaces. Scanning electron microscopy demonstrated that A. baumannii forms strong biofilms on stainless steel surfaces. This platform was combined with a colorimetric 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay to observe the metabolic activity of bacterial cells, and to facilitate the manipulation and comparison of multiple A. baumannii clinical strains. A strong correlation between XTT and c.f.u. assays was demonstrated. To complement the cell viability assays, A. baumannii biofilm mass was measured by crystal violet staining. Furthermore, the effect of commonly used disinfectants and environmental stressors on A. baumannii biofilms and planktonic cells was compared and characterized. Biofilms on SSWs were significantly more resistant than their planktonic counterparts, providing additional evidence that may allow us to understand the high prevalence of this microbe in hospital settings. Our results validate that SSWs are a simple, versatile and innovative method to study A. baumannii biofilms in vitro. PMID:24025603

Nitric oxide protects murine embryonic liver cells (BNL CL.2) from cytotoxicity induced by glucose deprivation.

PubMed

Pae, H O; Kim, H G; Paik, Y S; Paik, S G; Kim, Y M; Oh, G S; Chung, H T

2000-03-01

We investigated the protective effects of nitric oxide on cell death of murine embryonic liver cells (BNL CL.2) after glucose deprivation. Endogenous nitric oxide production by BNL CL.2 cells was induced by 6 hr pretreatment with interferon-gamma and lipopolysaccharide. We used sodium nitroprusside and S-nitroso-L-glutathione as exogenous nitric oxide-generating compounds. All agents were used at doses that did not show direct cytotoxicity as measured by crystal violet staining assay. In the BNL CL.2 cells, the viability dropped very steeply after 24 hr incubation with glucose-free media. Endogenous nitric oxide produced by treatment of the cells with interferon-gamma and lipopolysaccharide protected the cells from glucose deprivation-induced cytotoxicity, but did not protect them in the presence of the nitric oxide synthesis inhibitor, N(G)-monomethyl-L-arginine. Exogenous nitric oxide protected the cells from glucose deprivation-induced cytotoxicity in a concentration-dependent manner. Cytoprotection by nitric oxide donors was abolished by the use of nitric oxide scavenger, 2-phenyl-4,4,5,5,-tetramethylimidazole, but not by the soluble guanosine cyclase inhibitor, 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one. In addition, cytoprotective effects comparable to endogenous or exogenous nitric oxide were not observed when the cells were incubated with dibutyl guanosine 3',5'-cyclic monophosphate. Based upon these results, we suggest that nitric oxide may enhance the cell survival of BNL CL.2 cells after glucose deprivation via a guanosine 3',5'-cyclic monophosphate-independent pathway.

TLR7 expression is decreased during tumour progression in transgenic adenocarcinoma of mouse prostate mice and its activation inhibits growth of prostate cancer cells.

PubMed

Han, Ju-Hee; Park, Shin-Young; Kim, Jin-Bum; Cho, Sung-Dae; Kim, Bumseok; Kim, Bo-Yeon; Kang, Min-Jung; Kim, Dong-Jae; Park, Jae-Hak; Park, Jong-Hwan

2013-10-01

Although various Toll-like receptors (TLRs) have been associated with immune response and tumorigenesis in the prostate cells, little is known about the role of TLR7. Accordingly, we examined the expression of TLR7 during tumour progression of TRMAP (transgenic mouse model for prostate cancer) mice and its role on cell growth. Toll-like receptor7 expression was examined by RT-polymerase chain reaction (PCR), Western blot, and immunohistochemistry. Cell growth was examined by MTT assay. Colony formation was investigated by crystal violet staining. Strong expression of TLR7 was detected in the normal prostate epithelia of Wild-type (WT) mice, but not in TLR7-deficient mice. In contrast, TLR7 expression was weak in transgenic adenocarcinoma of mouse prostate (TRAMP)-C2 cells, as compared with murine bone marrow-derived macrophages (BMDMs). Moreover, TLR7 mRNA was markedly expressed in RWPE-1 cells (non-cancerous prostate epithelial cells), but not in PC3 and DU145 (prostate cancer cells). Immunohistochemically, TLR7 expression gradually decreased in TRAMP mice depending on the pathologic grade of the prostate cells. TLR7 agonists increased both the gene and protein expression of TLR7 and promoted production of proinflammatory cytokines/chemokines and IFN-β gene expression in prostate cancer cell lines. Moreover, loxoribine inhibited the growth and colony formation of TRAMP-C2 cells dependent of TLR7. These findings suggest that TLR7 may participate in tumour suppression in the prostate cells. © 2013 John Wiley & Sons Ltd.

In Vitro Effects of Polyphosphate against Prevotella intermedia in Planktonic Phase and Biofilm

PubMed Central

Jang, Eun-Young; Kim, Minjung; Noh, Mi Hee

2015-01-01

Polyphosphate (polyP) has gained a wide interest in the food industry due to its potential as a decontaminating agent. In this study, we examined the effect of sodium tripolyphosphate (polyP3; Na5P3O10) against planktonic and biofilm cells of Prevotella intermedia, a major oral pathogen. The MIC of polyP3 against P. intermedia ATCC 49046 determined by agar dilution method was 0.075%, while 0.05% polyP3 was bactericidal against P. intermedia in time-kill analysis performed using liquid medium. A crystal violet binding assay for the assessment of biofilm formation by P. intermedia showed that sub-MICs of polyP3 significantly decreased biofilm formation. Under the scanning electron microscope, decreased numbers of P. intermedia cells forming the biofilms were observed when the bacterial cells were incubated with 0.025% or higher concentrations of polyP3. Assessment of biofilm viability with LIVE/DEAD staining and viable cell count methods showed that 0.05% or higher concentrations of polyP3 significantly decreased the viability of the preformed biofilms in a concentration-dependent manner. The zone sizes of alpha-hemolysis formed on horse blood agar produced by P. intermedia were decreased in the presence of polyP3. The expression of the genes encoding hemolysins and the genes of the hemin uptake (hmu) locus was downregulated by polyP3. Collectively, our results show that polyP is an effective antimicrobial agent against P. intermedia in biofilms as well as planktonic phase, interfering with the process of hemin acquisition by the bacterium. PMID:26596937

Effects of Platinum Nanocolloid in Combination with Gamma Irradiation on Normal Human Esophageal Epithelial Cells.

PubMed

Li, Qiang; Tanaka, Yoshiharu; Saitoh, Yasukazu; Miwa, Nobuhiko

2016-05-01

Our previous study demonstrated that platinum nanocolloid (Pt-nc), combined with lower-dose gamma irradiation at 3, 5, and 7 Gy significantly decreased proliferation and accelerated apoptosis of the human esophageal squamous cell carcinoma-derived cell line KYSE-70. The aim of the present study was to determine, under the same conditions as our previous study where gamma rays combined with Pt-nc were carcinostatic to KYSE-70 cells, if we could induce a radioprotective or the radiation-sensitizing effect on the human normal esophageal epithelial cells (HEEpiC). HEEpiC were treated with various Pt-nc concentrations and then irradiated with various gamma-ray doses. The proliferative status of HEEpiC was evaluated using trypan blue dye-exclusion and WST-8 assays. The cellular and nucleic morphological features were determined using crystal violet and Hoechst 33342 stainings, respectively. The intracellular level of reactive oxygen species (ROS) in HEEpiC was evaluated with a nitro blue tetrazolium (NBT) assay. The apoptotic status was detected with caspase-3, Bax, and Bcl-2 by Western blotting. Either Pt-nc or gamma irradiation could inhibit the growth of HEEpiC; however, their combined use exerted a significant proliferation-inhibitory effect in a Pt-nc dose-dependent manner than gamma irradiation alone. Pt-nc resulted in radiation sensitization rather than radiation protection on HEEpiC in vitro similar to KYSE-70 cells, when Pt-nc was administrated alone or combined with gamma irradiation. Thus, Pt-nc has an inhibitory effect on cell proliferation, a facilitative effect on apoptosis, and a certain degree of toxicity against HEEpiC.

Influence of growth conditions on adhesion of yeast Candida spp. and Pichia spp. to stainless steel surfaces.

PubMed

Tomičić, Ružica; Raspor, Peter

2017-08-01

An understanding of adhesion behavior of Candida and Pichia yeast under different environmental conditions is key to the development of effective preventive measures against biofilm-associated infection. Hence in this study we investigated the impact of growth medium and temperature on Candida and Pichia adherence using stainless steel (AISI 304) discs with different degrees of surface roughness (Ra = 25.20-961.9 nm), material typical for the food processing industry as well as medical devices. The adhesion of the yeast strains to stainless steel surfaces grown in Malt Extract broth (MEB) or YPD broth at three temperatures (7 °C, 37 °C, 43 °C for Candida strains and 7 °C, 27 °C, 32 °C for Pichia strains) was assessed by crystal violet staining. The results showed that the nutrient content of medium significantly influenced the quantity of adhered cells by the tested yeasts. Adhesion of C. albicans and C. glabrata on stainless steel surfaces were significantly higher in MEB, whereas for C. parapsilosis and C. krusei it was YPD broth. In the case with P. pijperi and P. membranifaciens, YPD broth was more effective in promoting adhesion than MEB. On the other hand, our data indicated that temperature is a very important factor which considerably affects the adhesion of these yeast. There was also significant difference in cell adhesion on all types of stainless steel surfaces for all tested yeast. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Regulatory Roles of ncRNA Rli60 in Adaptability of Listeria monocytogenes to Environmental Stress and Biofilm Formation.

PubMed

Peng, Ye-Long; Meng, Qing-Ling; Qiao, Jun; Xie, Kun; Chen, Cheng; Liu, Tian-Li; Hu, Zheng-Xiang; Ma, Yu; Cai, Xue-Peng; Chen, Chuang-Fu

2016-07-01

Listeria monocytogenes is a facultative anaerobic Gram-positive bacterium. It is well adapted to external environments and able to infect both humans and animals. To understand the impacts of ncRNA Rli60 on the adaptability of L. monocytogenes to environmental stresses and biofilm formation, a rli60 deletion strain of L. monocytogenes (LM-Δrli60) was constructed using splicing by overlap extension PCR (SOE-PCR) and homologous recombination and then compared it with wild-type strain L. monocytogenes EGD-e in the aspects of adaptability to environmental stresses by measuring their growth under stresses of different temperatures, and acidic, alkaline, hypertonic and alcoholic conditions, and capability of biofilm formation by using crystal violet staining, as well as the transcriptional levels of genes (gltB and gltC) related to the biofilm formation by real-time quantitative PCR (qRT-PCR). The results showed that (1) the growth of LM-Δrli60 strain was significantly slower under environmental stresses of low temperature (30 °C), high temperature (42 °C), as well as alkaline and alcoholic conditions, (2) the amount of biofilm formed by LM-Δrli60 was attenuated, and (3) the transcriptional levels of gltB and gltC genes at 24 h and 48 h in LM-Δrli60 revealed a significant reduction. Overall, the results confirmed that ncRNA Rli60 plays important roles in regulating the adaptability of L. monocytogenes to environmental stresses and biofilm formation possibly through impacting the expression of gltB and gltC genes.

Biofilm prevention by dicephalic cationic surfactants and their interactions with DNA.

PubMed

Piecuch, A; Lamch, Ł; Paluch, E; Obłąk, E; Wilk, K A

2016-09-01

The studies were aimed to contribute to the elucidation of the relationships between structure of the double-headed cationic surfactants-N,N-bis[3,3'-(dimethylamine)- propyl]alkylamide dihydrochlorides and N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dibromides (alkyl: n-C9 H19 , n-C11 H23 , n-C13 H27 , n-C15 H31 ) and their antibacterial and biofilm preventing activity. The minimal inhibitory and bactericidal concentrations (MIC and MBC) of dicephalic surfactants against Staphylococcus epidermidis and Pseudomonas aeruginosa were tested using standard methods. Pseudomonas aeruginosa was resistant to studied compounds but MBC values against Staph. epidermidis reached 0·48-0·01 mmol l(-1) . The influence of dicephalic surfactants on bacterial biofilm and adhesion to the various surfaces was investigated with crystal violet staining or colony counting. The reduction in bacterial adhesion was observed, especially in the case of glass and stainless steel. The condensation of the DNA was shown in the ethidium bromide intercalation assay. Dicephalic surfactants exhibited antibacterial activity against Staph. epidermidis. The activity of studied compounds depended on the hydrocarbon chain length and the counterion. Surfactants deposited on different materials reduced Staph. epidermidis adhesion, dependently on the surfactant structure and the substratum. Dicephalic surfactants showed the ability of DNA compaction. This study points the possibility of application of dicephalic surfactants as the surface-coating agents to prevent biofilm formation. These compounds efficiently condensed DNA and are potential candidates for further studies towards the transfection. © 2016 The Society for Applied Microbiology.

Antimicrobial activity of some Ganoderma species from Nigeria.

PubMed

Ofodile, L N; Uma, N U; Kokubun, T; Grayer, R J; Ogundipe, O T; Simmonds, M S J

2005-04-01

The crude n-hexane:diethyl ether, chloroform:acetone and methanol extracts of four species of Ganoderma (Ganoderma colossum (Fr.) C. F. Baker, G. resinaceum Boud., G. lucidum (cf.) (Curtis) P. Karst. and G. boninense (cf.) Pat.), from Nigeria, were tested for antimicrobial activity. The three solvent extracts of all the species of Ganoderma were active against Pseudomonas syringae and Bacillus subtilis, whereas none of the extracts were active against Cladosporium herbarum. Preliminary thin layer chromatography chemical tests on these extracts of Ganoderma showed that they contained compounds that stained blue-violet and blue or green when sprayed with anisaldehyde-sulphuric acid or Dragendorff, respectively. The profile of compounds in the extracts showed some variation among the four species. (c) 2005 John Wiley & Sons, Ltd.

Results from the IMP-J violet solar cell experiment and violet cell balloon flights

NASA Technical Reports Server (NTRS)

Gaddy, E. M.

1976-01-01

The Interplanetary Monitoring Platform-J violet solar cell experiment was flown in an orbit with mild thermal cycling and low hard-particle radiation. The results of the experiment show that violet cells degrade at about the same rate as conventional cells in such an orbit. Balloon flight measurements show that violet solar cells produce approximately 20% more power than conventional cells.

Results from the IMP-J violet solar cell experiment and violet cell balloon flights

NASA Technical Reports Server (NTRS)

Gaddy, E. M.

1976-01-01

The IMP-J violet solar cell experiment was flown in an orbit with mild thermal cycling and low hard particle radiation. The results of the experiment show that violet cells degrade at about the same rate as conventional cells in such an orbit. Balloon flight measurements show that violet solar cells produce approximately 20% more power than conventional cells.

Effect of photobiomodulation on viability and proliferation of stem cells from exfoliated deciduous teeth under different nutritional conditions

NASA Astrophysics Data System (ADS)

Morato de Souza, Letícia; Guilherme Roque Rinco, Ugo; Aparecida Tavares Aguiar, Daniela; Aparecido de Almeida Junior, Luciano; Cosme-Silva, Leopoldo; Marchini Oliveira, Thais; Teixeira Marques, Nádia Carolina; Thiemy Sakai, Vivien

2018-02-01

This study aimed to evaluate the effect of different doses of low-level laser irradiation on the viability and proliferation of stem cells from exfoliated deciduous teeth (SHED) cultured under nutritional deficit (cellular stress) or regular nutritional conditions. SHED underwent irradiation by a red laser between 1.2 and 6.2 J cm-2. Prior to the irradiation, all groups received culture medium (MEMα, Eagle’s minimum essential medium alpha modification) supplemented with 1% of fetal bovine serum (FBS) for 1 h. After the irradiation, cells received MEMα supplemented with 10% of FBS (regular nutrition) or 1% of FBS (nutritional deficit). Cell viability and proliferation were respectively determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and crystal violet assays 6 and 24 h after irradiation (P  <  0.05). At 24 h, SHED under nutritional deficit showed lower viability and proliferation after 1.2 J cm-2 irradiation. All of the irradiated groups revealed significantly higher viability and proliferation in SHED maintained under nutritional deficit than in regular nutritional conditions, except in the 3.7 and 6.2 J cm-2 groups by MTT assay. In the crystal violet assay, SHED irradiated with 1.2 J cm-2 showed no difference between the different nutritional conditions. Decrease of FBS concentration in the culture medium seems to enhance the sensitivity of SHED to the effects of photobiomodulation therapy. Nutritional stress conditions improved cell viability and proliferation of SHED after laser irradiation, except for 1.2 J cm-2.

Crystal violet: Study of the photo-fading of an early synthetic dye in aqueous solution and on paper with HPLC-PDA, LC-MS and FORS

NASA Astrophysics Data System (ADS)

Confortin, Daria; Neevel, Han; Brustolon, Marina; Franco, Lorenzo; Kettelarij, Albert J.; Williams, Renè M.; van Bommel, Maarten R.

2010-06-01

The photo-fading of crystal violet (CV), one of the earliest synthetic dyes and an ink component, is examined both in solution and on paper. Aqueous solutions of CV were exposed to UV light (365nm) and samples were taken at constant time intervals and analysed with a High Performance Liquid Chromatography-Photo Diode Array (HPLC-PDA) and Liquid Chromatography-Mass Spectroscopy (LC-MS). Demethylation products were positively identified. Also, deamination probably occurred. The oxidation at the central carbon likely generates Michler's ketone (MK) or its derivatives, but still needs confirmation. To study CV on paper, Whatman paper was immersed in CV and exposed to UV light. Before and after different irradiation periods, reflectance spectra were recorded with Fibre Optic Reflectance Spectrophotometry (FORS). A decrease in CV concentration and a change in aggregation type for CV molecules upon irradiation was observed. Colorimetric L*a*b* values before and during irradiation were also measured. Also, CV was extracted from paper before and after different irradiation periods and analysed with HPLC-PDA. Photo-fading of CV on paper produced the same products as in solution, at least within the first 100 hours of irradiation. Finally, a photo-fading of CV in the presence of MK on Whatman paper was performed. It was demonstrated that MK both accelerates CV degradation and is consumed during the reaction. The degradation pathway identified in this work is suitable for explaining the photo/fading of other dyes belonging to the triarylmethane group.

Identification of methyl violet 2B as a novel blocker of focal adhesion kinase signaling pathway in cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hwan; Translational Research Center for Protein Function Control; Kim, Nam Doo

2013-07-26

Highlights: •FAK signaling cascade in cancer cells is profoundly inhibited by methyl violet 2B. •Methyl violet 2B identified by virtual screening is a novel allosteric FAK inhibitor. •Methyl violet 2B possesses extremely high kinase selectivity. •Methyl violet 2B suppresses strongly the proliferation of cancer cells. •Methyl violet 2B inhibits focal adhesion, invasion and migration of cancer cells. -- Abstract: The focal adhesion kinase (FAK) signaling cascade in cancer cells was profoundly inhibited by methyl violet 2B identified with the structure-based virtual screening. Methyl violet 2B was shown to be a non-competitive inhibitor of full-length FAK enzyme vs. ATP. It turnedmore » out that methyl violet 2B possesses extremely high kinase selectivity in biochemical kinase profiling using a large panel of kinases. Anti-proliferative activity measurement against several different cancer cells and Western blot analysis showed that this substance is capable of suppressing significantly the proliferation of cancer cells and is able to strongly block FAK/AKT/MAPK signaling pathways in a dose dependent manner at low nanomolar concentration. Especially, phosphorylation of Tyr925-FAK that is required for full activation of FAK was nearly completely suppressed even with 1 nM of methyl violet 2B in A375P cancer cells. To the best of our knowledge, it has never been reported that methyl violet possesses anti-cancer effects. Moreover, methyl violet 2B significantly inhibited FER kinase phosphorylation that activates FAK in cell. In addition, methyl violet 2B was found to induce cell apoptosis and to exhibit strong inhibitory effects on the focal adhesion, invasion, and migration of A375P cancer cells at low nanomolar concentrations. Taken together, these results show that methyl violet 2B is a novel, potent and selective blocker of FAK signaling cascade, which displays strong anti-proliferative activities against a variety of human cancer cells and suppresses adhesion/migration/invasion of tumor cells.« less

Evolutionary replacement of UV vision by violet vision in fish.

PubMed

Tada, Takashi; Altun, Ahmet; Yokoyama, Shozo

2009-10-13

The vertebrate ancestor possessed ultraviolet (UV) vision and many species have retained it during evolution. Many other species switched to violet vision and, then again, some avian species switched back to UV vision. These UV and violet vision are mediated by short wavelength-sensitive (SWS1) pigments that absorb light maximally (lambda(max)) at approximately 360 and 390-440 nm, respectively. It is not well understood why and how these functional changes have occurred. Here, we cloned the pigment of scabbardfish (Lepidopus fitchi) with a lambda(max) of 423 nm, an example of violet-sensitive SWS1 pigment in fish. Mutagenesis experiments and quantum mechanical/molecular mechanical (QM/MM) computations show that the violet-sensitivity was achieved by the deletion of Phe-86 that converted the unprotonated Schiff base-linked 11-cis-retinal to a protonated form. The finding of a violet-sensitive SWS1 pigment in scabbardfish suggests that many other fish also have orthologous violet pigments. The isolation and comparison of such violet and UV pigments in fish living in different ecological habitats will open an unprecedented opportunity to elucidate not only the molecular basis of phenotypic adaptations, but also the genetics of UV and violet vision.

Comparison of static and shake culture in the decolorization of textile dyes and dye effluents by Phanerochaete chrysoporium.

PubMed

Sani, R K; Azmi, W; Banerjee, U C

1998-01-01

Decolorization of several dyes (Red HE-8B, Malachite Green, Navy Blue HE-2R, Magenta, Crystal Violet) and an industrial effluent with growing cells of Phanerochaete chrysosporium in shake and static culture was demonstrated. All the dyes and the industrial effluent were decolorized to some extent with varying percentages of decolorization (20-100%). The rate of decolorization was very rapid with Red HE-8B, an industrial dye. Decolorization rates for all the dyes in static condition were found to be less than the shake culture and also dependent on biomass concentration.

75 FR 14468 - Carbazole Violet Pigment 23 From China and India

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-25

...)] Carbazole Violet Pigment 23 From China and India AGENCY: United States International Trade Commission... violet pigment 23 from India and the antidumping duty orders on carbazole violet pigment 23 from China and India. SUMMARY: The Commission hereby gives notice of the scheduling of expedited reviews pursuant...

Application of edible paraffin oil for cationic dye removal from water using emulsion liquid membrane.

PubMed

Zereshki, Sina; Daraei, Parisa; Shokri, Amin

2018-05-18

Using an emulsion liquid membrane based on edible oils is investigated for removing cationic dyes from aqueous solutions. There is a great potential for using edible oils in food industry extraction processes. The parameters affecting the stability of the emulsion and the extraction rate were studied. These parameters were the emulsification time, the stirring speed, the surfactant concentration, the internal phase concentration, the feed phase concentration, the volume ratio of internal phase to organic phase and the treat ratio. In order to stabilize the emulsion without using a carrier, edible paraffin oil and heptane are used at an 80:20 ratio. The optimum conditions for the extraction of methylene blue (MB), crystal violet and methyl violet (CV and MV) cationic dyes using edible paraffin oil as an environment friendly solvent are represented. A removal percentage of 95% was achieved for a mixture of dyes. The optimum concentration of sodium hydroxide in the internal phase, which results a stabile emulsion with a high stripping efficiency of 96%, was 0.04 M. An excellent membrane recovery was observed and the extraction of dyes did not decrease up to seven run cycles. Copyright © 2018 Elsevier B.V. All rights reserved.

Leuco-crystal-violet micelle gel dosimeters: Component effects on dose-rate dependence

NASA Astrophysics Data System (ADS)

Xie, J. C.; Katz, E. A. B.; Alexander, K. M.; Schreiner, L. J.; McAuley, K. B.

2017-05-01

Designed experiments were performed to produce empirical models for the dose sensitivity, initial absorbance, and dose-rate dependence respectively for leucocrystal violet (LCV) micelle gel dosimeters containing cetyltrimethylammonium bromide (CTAB) and 2,2,2-trichloroethanol (TCE). Previous gels of this type showed dose-rate dependent behaviour, producing an ˜18% increase in dose sensitivity between dose rates of 100 and 600 cGy min-1. Our models predict that the dose rate dependence can be reduced by increasing the concentration of TCE, CTAB and LCV. Increasing concentrations of LCV and CTAB produces a significant increase in dose sensitivity with a corresponding increase in initial absorbance. An optimization procedure was used to determine a nearly dose-rate independent gel which maintained high sensitivity and low initial absorbance. This gel which contains 33 mM CTAB, 1.25 mM LCV, and 96 mM TCE in 25 mM trichloroacetic acid and 4 wt% gelatin showed an increase in dose sensitivity of only 4% between dose rates of 100 and 600 cGy min-1, and provides an 80% greater dose sensitivity compared to Jordan’s standard gels with similar initial absorbance.

Decolorization and biodegradation of textile dye Navy blue HER by Trichosporon beigelii NCIM-3326.

PubMed

Saratale, R G; Saratale, G D; Chang, J S; Govindwar, S P

2009-07-30

Navy blue HER was decolorized and degraded within 24h by Trichosporon beigelii NCIM-3326 under static condition. In the present study, we investigated various physicochemical parameters such as agitation, temperature, pH, cell concentration, initial dye concentration and different carbon and nitrogen sources to achieve maximum dye degradation by T. beigelii. Sequentially, decolorization and decrease in the total organic carbon (TOC) of Navy blue HER by T. beigelii were measured. Among five strains T. beigelii gave the better performance on the decolorization of Navy blue HER along with a 95% TOC reduction within 24h. A significant increase in the activities of NADH-DCIP (dichlorophenolindophenol) reductase and azoreductase in the cells obtained after complete decolorization presumably indicates involvement of these enzymes in decolorization process. UV-vis, TLC, HPLC and FTIR analysis of extracted products confirmed the biodegradation of Navy blue HER. Phytotoxicity study demonstrated no toxicity of the biodegraded products with respect to plants viz. Phaseolus mungo and Sorghum vulgare. In addition to Navy blue HER, this strain also shows ability to decolorize various industrial dyes, including Red HE7B, Golden yellow 4BD, Green HE4BD, Orange HE2R, Malachite green, Crystal violet and Methyl violet.

21 CFR 74.2602 - D&C Violet No. 2.

Code of Federal Regulations, 2010 CFR

2010-04-01

... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2602 D&C Violet No. 2. (a) Identity and specifications. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of § 74.1602(a)(1) and (b). (b) Uses and restrictions. The color additive D&C Violet No. 2 may be...

75 FR 27815 - Carbazole Violet Pigment 23 From China and India; Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-18

...) Carbazole Violet Pigment 23 From China and India; Determinations On the basis of the record \\1\\ developed in... countervailing duty order on carbazole violet pigment 23 from India would be likely to lead to continuation or... that revocation of the antidumping duty orders on carbazole violet pigment 23 from China and India...

21 CFR 74.2602 - D&C Violet No. 2.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2602 D&C Violet No. 2. (a) Identity and specifications. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of § 74.1602(a)(1) and (b). (b) Uses and restrictions. The color additive D&C Violet No. 2 may be...

21 CFR 74.2602 - D&C Violet No. 2.

Code of Federal Regulations, 2013 CFR

2013-04-01

... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2602 D&C Violet No. 2. (a) Identity and specifications. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of § 74.1602(a)(1) and (b). (b) Uses and restrictions. The color additive D&C Violet No. 2 may be...

21 CFR 74.2602 - D&C Violet No. 2.

Code of Federal Regulations, 2012 CFR

2012-04-01

... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2602 D&C Violet No. 2. (a) Identity and specifications. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of § 74.1602(a)(1) and (b). (b) Uses and restrictions. The color additive D&C Violet No. 2 may be...

Mechanistic understanding of crystal violet dye sorption by woody biochar: implications for wastewater treatment.

PubMed

Wathukarage, Awanthi; Herath, Indika; Iqbal, M C M; Vithanage, Meththika

2017-08-17

Dye-based industries, particularly small and medium scale, discharge their effluents into waterways without treatment due to cost considerations. We investigated the use of biochars produced from the woody tree Gliricidia sepium at 300 °C (GBC300) and 500 °C (GBC500) in the laboratory and at 700 °C from a dendro bioenergy industry (GBC700), to evaluate their potential for sorption of crystal violet (CV) dye. Experiments were conducted to assess the effect of pH reaction time and CV loading on the adsorption process. The equilibrium adsorption capacity was higher with GBC700 (7.9 mg g -1 ) than GBC500 (4.9 mg g -1 ) and GBC300 (4.4 mg g -1 ), at pH 8. The CV sorption process was dependent on the pH, surface area and pore volume of biochar (GBC). Both Freundlich and Hill isotherm models fitted best to the equilibrium isotherm data suggesting cooperative interactions via physisorption and chemisorption mechanisms for CV sorption. The highest Hill sorption capacity of 125.5 mg g -1 was given by GBC700 at pH 8. Kinetic data followed the pseudo-second-order model, suggesting that the sorption process is more inclined toward the chemisorption mechanism. Pore diffusion, π-π electron donor-acceptor interaction and H-bonding were postulated to be involved in physisorption, whereas electrostatic interactions of protonated amine group of CV and negatively charged GBC surface led to a chemisorption type of adsorption. Overall, GBC produced as a by-product of the dendro industry could be a promising remedy for CV removal from an aqueous environment.

Blue light induced free radicals from riboflavin in degradation of crystal violet by microbial viability evaluation.

PubMed

Liang, Ji-Yuan; Yuann, Jeu-Ming P; Hsie, Zong-Jhe; Huang, Shiuh-Tsuen; Chen, Chiing-Chang

2017-09-01

Crystal violet (CV) is applied in daily use mainly as a commercial dye and antimicrobial agent. Waste water containing CV may affect aquatic ecosystems. Riboflavin, also known as vitamin B 2 , is non-toxic and an essential vitamin required for the functions of the human body. Riboflavin is photosensitive to UV and visible light in terms of generating reactive oxygen species. This study investigated the potential application of blue light on riboflavin, so as to come up with an effective way of degrading CV during its treatment. Photosensitivity of CV leading to degradation in the presence of riboflavin was investigated by light intensity, exposure time, and irradiation dosage. The degradation of CV during riboflavin photolysis treatment was studied by a UV/vis spectrometry and chromatography. The effects of CV degradation on microbial viability are relevant when considering the influences on the ecosystem. This study proved that riboflavin photochemical treatment with blue light degrades CV dye by ROS formation. The riboflavin photolysis-treated CV solution appeared to be transparent during conformational transformations of the CV that was rearranged by free radical species generated from riboflavin photolysis. After riboflavin photolysis, colony-forming units (CFUs) were determined for each CV solution. CFU preservation was 85.2% for the CV dissolved riboflavin solution treated with blue light irradiation at 2.0mW/cm 2 for 120min. Degradation of CV by riboflavin photochemical procedures can greatly reduce antimicrobial ability and serve as an environmental friendly waste water treatment method. Our results presented here concerning riboflavin photolysis in degradation of CV provide a novel technique, and a simple and safe practice for environmental decontamination processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of sonochemical parameters and inorganic ions during the sonochemical degradation of crystal violet in water.

PubMed

Guzman-Duque, Fernando; Pétrier, Christian; Pulgarin, Cesar; Peñuela, Gustavo; Torres-Palma, Ricardo A

2011-01-01

This work deals with the ultrasonic degradation (800 kHz) of crystal violet (CV) under different experimental conditions. The effects of saturating gas (argon, carbon dioxide and air), CV concentration (2.45-1225 μmol L(-1)), pH (3-9) and power (20-80 W) were evaluated. The best performances were obtained at 80 W with argon as a saturating gas. The pH had no significant effect. The influence of several water matrices containing anions (chloride, sulphate and bicarbonate) and cations (Fe(2+)) on the sonolytic degradation of CV was also investigated. Significant differences were not observed with the presence of chloride and sulphate. However, at relatively low pollutant concentration (2.45 μmol L(-1)) bicarbonate showed a particular effect: a high bicarbonate concentration (350 mmol L(-1)) produced a detrimental effect, while a low bicarbonate concentration (3 mmol L(-1)) increased the efficiency of the process. The presence of Fe(2+) (1 mmol L(-1)) also increased the CV (49 μmol L(-1)) degradation by 32% after 180 min. Analyses of intermediates by GC-MS led to the identification of several sonochemical by-products: N,N-dimethylaminobenzene, 4-(N,N-dimethylamino)-4'-(N',N'-dimethylamino)benzophenone, and N,N,N',N'-tetramethyl-4,4'-diaminodiphenylmethane. The presence of these aromatic structures showed that the main ultrasonic CV degradation pathway is linked to the reaction with *OH radicals. At the end of the treatment, these early products were converted into biodegradable organic by-products which could be easily treated in a subsequent biological treatment. Copyright © 2010 Elsevier B.V. All rights reserved.

Effects of low-level laser therapy on stem cells from human exfoliated deciduous teeth.

PubMed

Fernandes, Ana Paula; Junqueira, Marina de Azevedo; Marques, Nádia Carolina Teixeira; Machado, Maria Aparecida Andrade Moreira; Santos, Carlos Ferreira; Oliveira, Thais Marchini; Sakai, Vivien Thiemy

2016-01-01

This study aimed to evaluate the influence of different laser therapy energy densities on SHED viability and proliferation. SHED were irradiated according to the groups: I (1.2 J/cm2 - 0.5 mW - 10 s), II (2.5 J/cm2 - 10 mW - 10 s), III (3.7 J/cm2 - 15 mW - 10 s), IV (5.0 J/cm2 - 20 mW - 10 s), V (6.2 J/cm2 - 25 mW - 10 s), and VI (not irradiated - control group). Cell viability was assessed 6 and 24 h after irradiation measuring the mitochondrial activity and using the Crystal Violet assay. Cell proliferation was assessed after 24, 48, and 72 h of irradiation by SRB assay. MTT assay demonstrated differences from 6 to 24 hours after irradiation. After 24 h, groups I and IV showed higher absorbance values than those of control group. Crystal Violet assay showed statistically differences in the absorbance rate from 6 to 24 h after irradiation for groups III and VI. At 24 h after irradiation, Group III absorbance rate was greater than that of groups I, II, and IV. Group VI absorbance rate was greater than that of groups I and IV. SRB assay showed that the group I had higher rates than those of groups II, III, V, and VI, at 24 h after irradiation. After 48 h, group I exhibited the greatest cell proliferation rate followed by groups III, V, and VI. After 72 h, group III exhibited the lowest cell proliferation rate than those of groups II, IV, and V. The Low-Level Laser Therapy energy densities used in this study did not cause loss of cell viability and stimulated SHED proliferation within the parameters described in this study.

Synthesis of magnetic mesoporous metal-organic framework-5 for the effective enrichment of malachite green and crystal violet in fish samples.

PubMed

Zhou, Zhihui; Fu, Yanqing; Qin, Qian; Lu, Xin; Shi, Xianzhe; Zhao, Chunxia; Xu, Guowang

2018-07-27

A novel, magnetic and mesoporous Fe 3 O 4 @PEI-MOF-5 material was synthesized for the effective enrichment of malachite green (MG) and crystal violet (CV) in fish samples. The Fe 3 O 4 @PEI-MOF-5 material was prepared by a facile two-step solvothermal approach in which Fe 3 O 4 @PEI and MOF-5 were connected through chemical bonds. Characterization of the newly synthesized Fe 3 O 4 @PEI-MOF-5 material was performed by Fourier transform infrared spectroscopy, X-ray diffractometry, vibrating sample magnetometry, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis and X-ray photoelectron spectroscopy. This new material was determined to have high magnetization and chemical stability, a large surface area and a distinctive morphology. An effective enrichment and detection method for MG and CV was subsequently developed by combining the Fe 3 O 4 @PEI-MOF-5 material with ultra-high-performance liquid chromatography-tandem mass spectrometry. The linearity ranges of this approach for MG and CV were 1-500ng/mL and 0.25-500ng/mL, respectively, with correlation coefficients (R 2 ) of 0.999. The limits of detection (LODs) of the method for MG and CV were 0.30ng/mL and 0.08ng/mL, respectively, indicating that the Fe 3 O 4 @PEI-MOF-5 material had good adsorption properties for MG and CV. Fe 3 O 4 @PEI-MOF-5 can be expected to also provide efficient enrichment of MG and CV in other complex matrices. Copyright © 2018 Elsevier B.V. All rights reserved.

Simultaneous spectrophotometric determination of crystal violet and malachite green in water samples using partial least squares regression and central composite design after preconcentration by dispersive solid-phase extraction.

PubMed

Razi-Asrami, Mahboobeh; Ghasemi, Jahan B; Amiri, Nayereh; Sadeghi, Seyed Jamal

2017-04-01

In this paper, a simple, fast, and inexpensive method is introduced for the simultaneous spectrophotometric determination of crystal violet (CV) and malachite green (MG) contents in aquatic samples using partial least squares regression (PLS) as a multivariate calibration technique after preconcentration by graphene oxide (GO). The method was based on the sorption and desorption of analytes onto GO and direct determination by ultraviolet-visible spectrophotometric techniques. GO was synthesized according to Hummers method. To characterize the shape and structure of GO, FT-IR, SEM, and XRD were used. The effective factors on the extraction efficiency such as pH, extraction time, and the amount of adsorbent were optimized using central composite design. The optimum values of these factors were 6, 15 min, and 12 mg, respectively. The maximum capacity of GO for the adsorption of CV and MG was 63.17 and 77.02 mg g -1 , respectively. Preconcentration factors and extraction recoveries were obtained and were 19.6, 98% for CV and 20, 100% for MG, respectively. LOD and linear dynamic ranges for CV and MG were 0.009, 0.03-0.3, 0.015, and 0.05-0.5 (μg mL -1 ), respectively. The intra-day and inter-day relative standard deviations were 1.99 and 0.58 for CV and 1.69 and 3.13 for MG at the concentration level of 50 ng mL -1 , respectively. Finally, the proposed DSPE/PLS method was successfully applied for the simultaneous determination of the trace amount of CV and MG in the real water samples.

Evaluation of DNA colony hybridization and other techniques for detection of virulence in Yersinia species.

PubMed Central

Robins-Browne, R M; Miliotis, M D; Cianciosi, S; Miller, V L; Falkow, S; Morris, J G

1989-01-01

The virulence of yersiniae varies according to (i) species and biotype and (ii) possession of a 67- to 72-kilobase virulence plasmid. Y. pestis, Y. pseudotuberculosis, and biotypes 1B, 2, 3, 4, and 5 of Y. enterocolitica are inherently virulent but express full virulence only when in possession of a virulence plasmid. Other Yersinia species and biotypes 1A and 3B of Y. enterocolitica are seldom implicated in disease. In this study, we prepared DNA probes from eight nonoverlapping regions of the virulence plasmid of a strain of Y. enterocolitica and from the inv and ail chromosomal loci responsible for the invasive capacity of Y. enterocolitica and Y. pseudotuberculosis. The probes were used in colony hybridization experiments to investigate 156 yersiniae of various species and biotypes and of differing virulence. Probes prepared from the inv gene of Y. pseudotuberculosis hybridized with Y. pseudotuberculosis and Y. pestis only, whereas an analogous probe prepared from Y. enterocolitica hybridized with all species and biotypes of yersiniae (but not with other bacteria) regardless of virulence or potential virulence. Probes prepared from the ail region of Y. enterocolitica reacted almost exclusively with Y. enterocolitica strains of pathogenic biotypes. Probes prepared from the virulence plasmid of a serogroup O:8, biotype 1B isolate of Y. enterocolitica identified virulent yersiniae in all species with a high degree of sensitivity and specificity. These probes did not react with yersiniae of avirulent biotypes or species. Of the other assays of virulence evaluated (calcium dependence, binding of crystal violet, and pyrazinamidase activity), binding of crystal violet provided a simple means for identifying plasmid-bearing strains. Images PMID:2723033

SERS active Ag encapsulated Fe@SiO2 nanorods in electromagnetic wave absorption and crystal violet detection.

PubMed

Senapati, Samarpita; Srivastava, Suneel Kumar; Singh, Shiv Brat; Kulkarni, Ajit R

2014-11-01

The present work is focused on the preparation of Fe nanorods by the chemical reduction of FeCl3 (aq) using NaBH4 in the presence of glycerol as template followed by annealing of the product at 500°C in the presence of H2 gas flow. Subsequently, its surface has been modified by silica followed by silver nanoparticles to form silica coated Fe (Fe@SiO2) and Ag encapsulated Fe@SiO2 nanostructure employing the Stöber method and silver mirror reaction respectively. XRD pattern of the products confirmed the formation of bcc phase of iron and fcc phase of silver, though silica remained amorphous. FESEM images established the growth of iron nanorods from the annealed product and also formation of silica and silver coating on its surface. The appearance of the characteristics bands in FTIR confirmed the presence of SiO2 on the Fe surface. Magnetic measurements at room temperature indicated the ferromagnetic behavior of as prepared iron nanorods, Fe@SiO2 and silver encapsulated Fe@SiO2 nanostructures. All the samples exhibited strong microwave absorption property in the high frequency range (10GHz), though it is superior for Ag encapsulated Fe@SiO2 (-14.7dB) compared with Fe@SiO2 (-9.7dB) nanostructures of the same thickness. The synthesized Ag encapsulated Fe@SiO2 nanostructure also exhibited the SERS phenomena, which is useful in the detection of the carcinogenic dye crystal violet (CV) upto the concentration of 10(-10)M. All these findings clearly demonstrate that the Ag encapsulated Fe@SiO2 nanostructure could efficiently be used in the environmental remediation. Copyright © 2014 Elsevier Inc. All rights reserved.

21 CFR 73.2775 - Manganese violet.

Code of Federal Regulations, 2012 CFR

2012-04-01

... manganese violet is a violet pigment obtained by reacting phosphoric acid, ammonium dihydrogen orthophosphate, and manganese dioxide at temperatures above 450 °F. The pigment is a manganese ammonium...

Design Considerations for a Water Treatment System Utilizing Ultra-Violet Light Emitting Diodes

DTIC Science & Technology

2014-03-27

DESIGN CONSIDERATIONS FOR A WATER TREATMENT SYSTEM UTILIZING ULTRA-VIOLET LIGHT EMITTING DIODES...the United States. ii AFIT-ENV-14-M-58 DESIGN CONSIDERATIONS FOR A WATER TREATMENT SYSTEM UTILIZING ULTRA-VIOLET LIGHT EMITTING DIODES...DISTRIBUTION UNLIMITED. iii AFIT-ENV-14-M-58 DESIGN CONSIDERATIONS FOR A WATER TREATMENT SYSTEM UTILIZING ULTRA-VIOLET LIGHT EMITTING

Survival and detection of coliforms, Enterobacteriaceae, and gram-negative bacteria in Greek yogurt.

PubMed

Hervert, C J; Martin, N H; Boor, K J; Wiedmann, M

2017-02-01

Despite the widespread use of coliforms as indicator bacteria, increasing evidence suggests that the Enterobacteriaceae (EB) and total gram-negative groups more accurately reflect the hygienic status of high-temperature, short-time pasteurized milk and processing environments. If introduced into milk as postpasteurization contamination, these bacteria may grow to high levels and produce a wide range of sensory-related defects. However, limited information is available on the use and survival of bacterial hygiene indicators in dairy products outside of pasteurized fluid milk and cheese. The goal of this study was to (1) provide information on the survival of a diverse set of bacterial hygiene indicators in the low pH environment of Greek yogurt, (2) compare traditional and alternative detection methods for their ability to detect bacterial hygiene indicators in Greek yogurt, and (3) offer insight into optimal hygiene indicator groups for use in low-pH fermented dairy products. To this end, we screened 64 bacterial isolates, representing 24 dairy-relevant genera, for survival and detection in Greek yogurt using 5 testing methods. Before testing, isolates were inoculated into plain, 0% fat Greek yogurt (pH 4.35 to 4.65), followed by a 12-h hold period at 4 ± 1°C. Yogurts were subsequently tested using Coliform Petrifilm (3M, St. Paul, MN) to detect coliforms; Enterobacteriaceae Petrifilm (3M), violet red bile glucose agar and the D-Count (bioMérieux, Marcy-l'Étoile, France) to detect EB; and crystal violet tetrazolium agar (CVTA) to detect total gram-negative bacteria. Overall, the non-EB gram-negative isolates showed significantly larger log reductions 12 h after inoculation into Greek yogurt (based on bacterial numbers recovered on CVTA) compared with the coliform and noncoliform EB isolates tested. The methods evaluated varied in their ability to detect different microbial hygiene indicators in Greek yogurt. Crystal violet tetrazolium agar detected the highest portion of coliforms, whereas EB Petrifilm detected the highest portion of EB, as well as highest portion of total gram-negative bacteria. Additionally, the D-Count method allowed for faster detection of EB in yogurt by generating results in approximately 13 h rather than the 24 h required when using EB Petrifilm and violet red bile glucose agar. Results from this study indicate that the coliform and EB groups encompass a broad range of dairy-relevant gram-negative bacteria with the ability to survive in Greek yogurt, supporting their use as microbial hygiene indicator groups in low-pH fermented dairy products. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

A combined pharmacodynamic quantitative and qualitative model reveals the potent activity of daptomycin and delafloxacin against Staphylococcus aureus biofilms.

PubMed

Bauer, Julia; Siala, Wafi; Tulkens, Paul M; Van Bambeke, Françoise

2013-06-01

Biofilms are associated with persistence of Staphylococcus aureus infections and therapeutic failures. Our aim was to set up a pharmacodynamic model comparing antibiotic activities against biofilms and examining in parallel their effects on viability and biofilm mass. Biofilms of S. aureus ATCC 25923 (methicillin-sensitive S. aureus [MSSA]) or ATCC 33591 (methicillin-resistant S. aureus [MRSA]) were obtained by culture in 96-well plates for 6 h/24 h. Antibiotic activities were assessed after 24/48 h of exposure to concentrations ranging from 0.5 to 512 times the MIC. Biofilm mass and bacterial viability were quantified using crystal violet and the redox indicator resazurin. Biofilms stained with Live/Dead probes were observed by using confocal microscopy. Concentration-effect curves fitted sigmoidal regressions, with a 50% reduction toward both matrix and viability obtained at sub-MIC or low multiples of MICs against young biofilms for all antibiotics tested. Against mature biofilms, maximal efficacies and potencies were reduced, with none of the antibiotics being able to completely destroy the matrix. Delafloxacin and daptomycin were the most potent, reducing viability by more than 50% at clinically achievable concentrations against both strains, as well as reducing biofilm depth, as observed in confocal microscopy. Rifampin, tigecycline, and moxifloxacin were effective against mature MRSA biofilms, while oxacillin demonstrated activity against MSSA. Fusidic acid, vancomycin, and linezolid were less potent overall. Antibiotic activity depends on biofilm maturity and bacterial strain. The pharmacodynamic model developed allows ranking of antibiotics with respect to efficacy and potency at clinically achievable concentrations and highlights the potential utility of daptomycin and delafloxacin for the treatment of biofilm-related infections.

A Combined Pharmacodynamic Quantitative and Qualitative Model Reveals the Potent Activity of Daptomycin and Delafloxacin against Staphylococcus aureus Biofilms

PubMed Central

Bauer, Julia; Siala, Wafi; Tulkens, Paul M.

2013-01-01

Biofilms are associated with persistence of Staphylococcus aureus infections and therapeutic failures. Our aim was to set up a pharmacodynamic model comparing antibiotic activities against biofilms and examining in parallel their effects on viability and biofilm mass. Biofilms of S. aureus ATCC 25923 (methicillin-sensitive S. aureus [MSSA]) or ATCC 33591 (methicillin-resistant S. aureus [MRSA]) were obtained by culture in 96-well plates for 6 h/24 h. Antibiotic activities were assessed after 24/48 h of exposure to concentrations ranging from 0.5 to 512 times the MIC. Biofilm mass and bacterial viability were quantified using crystal violet and the redox indicator resazurin. Biofilms stained with Live/Dead probes were observed by using confocal microscopy. Concentration-effect curves fitted sigmoidal regressions, with a 50% reduction toward both matrix and viability obtained at sub-MIC or low multiples of MICs against young biofilms for all antibiotics tested. Against mature biofilms, maximal efficacies and potencies were reduced, with none of the antibiotics being able to completely destroy the matrix. Delafloxacin and daptomycin were the most potent, reducing viability by more than 50% at clinically achievable concentrations against both strains, as well as reducing biofilm depth, as observed in confocal microscopy. Rifampin, tigecycline, and moxifloxacin were effective against mature MRSA biofilms, while oxacillin demonstrated activity against MSSA. Fusidic acid, vancomycin, and linezolid were less potent overall. Antibiotic activity depends on biofilm maturity and bacterial strain. The pharmacodynamic model developed allows ranking of antibiotics with respect to efficacy and potency at clinically achievable concentrations and highlights the potential utility of daptomycin and delafloxacin for the treatment of biofilm-related infections. PMID:23571532

Preclinical Testing of an Oncolytic Parvovirus: Standard Protoparvovirus H-1PV Efficiently Induces Osteosarcoma Cell Lysis In Vitro

PubMed Central

Leuchs, Barbara; Frank-Stöhr, Monika; Schlehofer, Jörg R.; Rommelaere, Jean; Lacroix, Jeannine

2017-01-01

Osteosarcoma is the most frequent malignant disease of the bone. On the basis of early clinical experience in the 1960s with H-1 protoparvovirus (H-1PV) in osteosarcoma patients, this effective oncolytic virus was selected for systematic preclinical testing on various osteosarcoma cell cultures. A panel of five human osteosarcoma cell lines (CAL 72, H-OS, MG-63, SaOS-2, U-2OS) was tested. Virus oncoselectivity was confirmed by infecting non-malignant human neonatal fibroblasts and osteoblasts used as culture models of non-transformed mesenchymal cells. H-1PV was found to enter osteosarcoma cells and to induce viral DNA replication, transcription of viral genes, and translation to viral proteins. After H-1PV infection, release of infectious viral particles from osteosarcoma cells into the supernatant indicated successful viral assembly and egress. Crystal violet staining revealed progressive cytomorphological changes in all osteosarcoma cell lines. Infection of osteosarcoma cell lines with the standard H-1PV caused an arrest of the cell cycle in the G2 phase, and these lines had a limited capacity for standard H-1PV virus replication. The cytotoxicity of wild-type H-1PV virus towards osteosarcoma cells was compared in vitro with that of two variants, Del H-1PV and DM H-1PV, previously described as fitness variants displaying higher infectivity and spreading in human transformed cell lines of different origins. Surprisingly, wild-type H-1PV displayed the strongest cytostatic and cytotoxic effects in this analysis and thus seems the most promising for the next preclinical validation steps in vivo. PMID:29039746

Inactivation of Cronobacter malonaticus cells and inhibition of its biofilm formation exposed to hydrogen peroxide stress.

PubMed

Ye, Yingwang; Zhang, Maofeng; Jiao, Rui; Ling, Na; Zhang, Xiyan; Tong, Liaowang; Zeng, Haiyang; Zhang, Jumei; Wu, Qingping

2018-01-01

Presence of Cronobacter malonaticus in powdered infant formula (PIF) poses a high risk to infant and public health. Cronobacter malonaticus has been widely distributed in food and food processing environments, and the true origin of C. malonaticus in PIF is poorly understood. Control and prevention of C. malonaticus is necessary for achieving microbial safety of PIF. However, little information about decontamination of C. malonaticus is available. In this study, effects of hydrogen peroxide on inactivation and morphological changes of C. malonaticus cells were determined. Furthermore, inhibitory effects of H 2 O 2 on biofilm formation in C. malonaticus were also performed. Results indicated that H 2 O 2 could completely inactivate C. malonaticus in sterile water with 0.06% H 2 O 2 for 25 min, 0.08% H 2 O 2 for 15 min, and 0.10% for 10 min, respectively, whereas the survival rates of C. malonaticus in tryptic soy broth medium significantly increased with the same treatment time and concentration of H 2 O 2 . In addition, morphological changes of C. malonaticus cells, including cell shrinkage, disruption of cells, cell intercession, and leakage of intercellular material in sterile water after H 2 O 2 treatment, were more predominant than those in tryptic soy broth. Finally, significant reduction in biofilm formation by H 2 O 2 was found using crystal violet staining, scanning electron microscopy, and confocal laser scanning microscopy detection compared with control samples. This is the first report to determine the effects of H 2 O 2 on C. malonaticus cells and biofilm formation. The findings provided valuable information for practical application of H 2 O 2 for decontamination of C. malonaticus in dairy processing. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Norfloxacin salts of carboxylic acids curtail planktonic and biofilm mode of growth in ESKAPE pathogens.

PubMed

Lowrence, R C; Ramakrishnan, A; Sundaramoorthy, N S; Shyam, A; Mohan, V; Subbarao, H M V; Ulaganathan, V; Raman, T; Solomon, A; Nagarajan, S

2018-02-01

To enhance the antimicrobial and antibiofilm activity of norfloxacin against the planktonic and biofilm mode of growth in ESKAPE pathogens using chemically modified norfloxacin salts. Antimicrobial testing, synergy testing and time-kill curve analysis were performed to evaluate antibacterial effect of norfloxacin carboxylic acid salts against ESKAPE pathogens. In vivo efficacy to reduce bacterial bioburden was evaluated in zebrafish infection model. Crystal violet assay and live-dead staining were performed to discern antibiofilm effect. Membrane permeability, integrity and molecular docking studies were carried out to ascertain the mechanism of action. The carboxylic acid salts, relative to parent molecule norfloxacin, displayed two- to fourfold reduction in minimum inhibitory concentration against Staphylococcus aureus and Pseudomonas aeruginosa, in addition to displaying potent bacteriostatic effect against certain members of ESKAPE pathogens. In vivo treatments revealed that norfloxacin tartrate (SRIN2) reduced MRSA bioburden by greater than 1 log fold relative to parent molecule in the muscle tissue. In silico docking with gyrA of S. aureus showed increased affinity of SRIN2 towards DNA gyrase. The enhanced antibacterial effect of norfloxacin salts could be partially accounted by altered membrane permeability in S. aureus and perturbed membrane integrity in P. aeruginosa. Antibiofilm studies revealed that SRIN2 (norfloxacin tartrate) and SRIN3 (norfloxacin benzoate) exerted potent antibiofilm effect particularly against Gram-negative ESKAPE pathogens. The impaired colonization of both S. aureus and P. aeruginosa due to improved norfloxacin salts was further supported by live-dead imaging. Norfloxacin carboxylic acid salts can act as potential alternatives in terms of drug resensitization and reuse. Our study shows that carboxylic acid salts of norfloxacin could be effectively employed to treat both planktonic- and biofilm-based infections caused by select members of ESKAPE pathogens. © 2017 The Society for Applied Microbiology.

l-Methionine anti-biofilm activity against Pseudomonas aeruginosa is enhanced by the cystic fibrosis transmembrane conductance regulator potentiator, ivacaftor.

PubMed

Cho, Do-Yeon; Lim, Dong-Jin; Mackey, Calvin; Weeks, Christopher G; Peña Garcia, Jaime A; Skinner, Daniel; Grayson, Jessica W; Hill, Harrison S; Alexander, David K; Zhang, Shaoyan; Woodworth, Bradford A

2018-05-01

Biofilms may contribute to refractory chronic rhinosinusitis (CRS), as they lead to antibiotic resistance and failure of effective clinical treatment. l-Methionine is an amino acid with reported biofilm-inhibiting properties. Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator with mild antimicrobial activity via inhibition of bacterial DNA gyrase and topoisomerase IV. The objective of this study was to evaluate whether co-treatment with ivacaftor and l-methionine can reduce the formation of Pseudomonas aeruginosa biofilms. P aeruginosa (PAO-1 strain) biofilms were studied in the presence of l-methionine and/or ivacaftor. For static biofilm assays, PAO-1 was cultured in a 48-well plate for 72 hours with stepwise combinations of these agents. Relative biofilm inhibitions were measured according to optical density of crystal violet stain at 590 nm. Live/dead assays (BacTiter-Glo™ assay, Promega) were imaged with laser scanning confocal microscopy. An agar diffusion test was used to confirm antibacterial effects of the drugs. l-Methionine (0.5 μM) significantly reduced PAO-1 biofilm mass (32.4 ± 18.0%; n = 4; p < 0.001) compared with controls. Low doses of ivacaftor alone (4, 8, and 12 μg/mL) had no effect on biofilm formation. When combined with ivacaftor (4 μg/mL), a synergistic anti-biofilm effect was noted at 0.05 μM and 0.5 μM of l-methionine (two-way analysis of variane, p = 0.0415) compared with corresponding concentrations of l-methionine alone. Ivacaftor enhanced the anti-biofilm activity of l-methionine against the PAO-1 strain of P aeruginosa. Further studies evaluating the efficacy of ivacaftor/l-methionine combinations for P aeruginosa sinusitis are planned. © 2018 ARS-AAOA, LLC.

Inosine Released from Dying or Dead Cells Stimulates Cell Proliferation via Adenosine Receptors.

PubMed

Chen, Jin; Chaurio, Ricardo A; Maueröder, Christian; Derer, Anja; Rauh, Manfred; Kost, Andriy; Liu, Yi; Mo, Xianming; Hueber, Axel; Bilyy, Rostyslav; Herrmann, Martin; Zhao, Yi; Muñoz, Luis E

2017-01-01

Many antitumor therapies induce apoptotic cell death in order to cause tumor regression. Paradoxically, apoptotic cells are also known to promote wound healing, cell proliferation, and tumor cell repopulation in multicellular organisms. We aimed to characterize the nature of the regenerative signals concentrated in the micromilieu of dead and dying cells. Cultures of viable melanoma B16F10 cells, mouse fibroblasts, and primary human fibroblast-like synoviocytes (FLS) in the presence of dead and dying cells, their supernatants (SNs), or purified agonists and antagonists were used to evaluate the stimulation of proliferation. Viable cell quantification was performed by either flow cytometry of harvested cells or by crystal violet staining of adherent cells. High-performance liquid chromatography and liquid chromatography coupled with mass spectrometry of cell SNs were deployed to identify the nature of growth-promoting factors. Coimplantation of living cells in the presence of SNs collected from dead and dying cells and specific agonists was used to evaluate tumor growth in vivo . The stimulation of proliferation of few surviving cells by bystander dead cells was confirmed for melanoma cells, mouse fibroblasts, and primary FLS. We found that small soluble molecules present in the protein-free fraction of SNs of dead and dying cells were responsible for the promotion of proliferation. The nucleoside inosine released by dead and dying cells acting via adenosine receptors was identified as putative inducer of proliferation of surviving tumor cells after irradiation and heat treatment. Inosine released by dead and dying cells mediates tumor cell proliferation via purinergic receptors. Therapeutic strategies surmounting this pathway may help to reduce the rate of recurrence after radio- and chemotherapy.

Characterization of the clustered regularly interspaced short palindromic repeats sites in Streptococcus mutans isolated from early childhood caries patients.

PubMed

Chen, Jing; Li, Tiancheng; Zhou, Xuedong; Cheng, Lei; Huo, Yuanyuan; Zou, Jing; Li, Yuqing

2017-11-01

The aim of this study was to analyze the characteristics of the clustered regularly interspaced short palindromic repeats (CRISPR) sites in 45 clinical Streptococcus mutans strains and their relationship to the clinical manifestations of early childhood caries (ECC). Forty-five S. mutans strains were isolated from the plaque samples taken from sixty-three children. CRISPR sites were sequenced and BLAST was used to compare these sites to those in the CRISPRTarget database. The association between the distribution of CRISPR sites and the manifestation of caries was analyzed by Chi-Square test. Further, biofilm formation (by crystal violet staining) and the synthesis of polysaccharide (by anthrone-sulfuric method) of all clinical isolated S. mutans strains with both CRISPR sites and no CRISPR site were comapared. Finally, acidogenicity and acidurity of two typical strains were determined using pH drop and acid tolerance assays. Biofilm formation and EPS synthesis by two typical strains were compared by 3D CLSM (Confocal Laser Scanning Microscope) assays and the expression of gtf genes were evaluated using qPCR. We found that most of the spacers in the clinical S. mutans strains were derived from Streptococcus phages APCM01 and M102. The number of CRISPR sites in these strains was associated with the clinical manifestations of ECC. Moreover, we found that the biofilm formation and EPS synthesis ability of the S. mutans strains with both CRISPR sites was significant improved. An association was found between the distribution of CRISPR sites and the clinical manifestations of caries. The CRISPR sites might contribute to the cariogenic potential of S. mutans. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamics of biofilm formation and the interaction between Candida albicans and methicillin-susceptible (MSSA) and -resistant Staphylococcus aureus (MRSA).

PubMed

Zago, Chaiene Evelin; Silva, Sónia; Sanitá, Paula Volpato; Barbugli, Paula Aboud; Dias, Carla Maria Improta; Lordello, Virgínia Barreto; Vergani, Carlos Eduardo

2015-01-01

Polymicrobial biofilms are an understudied and a clinically relevant problem. This study evaluates the interaction between C. albicans, and methicillin- susceptible (MSSA) and resistant (MRSA) S. aureus growing in single- and dual-species biofilms. Single and dual species adhesion (90 min) and biofilms (12, 24, and 48 h) were evaluated by complementary methods: counting colony-forming units (CFU mL-1), XTT-reduction, and crystal violet staining (CV). The secretion of hydrolytic enzymes by the 48 h biofilms was also evaluated using fluorimetric kits. Scanning electron microscopy (SEM) was used to assess biofilm structure. The results from quantification assays were compared using two-way ANOVAs with Tukey post-hoc tests, while data from enzymatic activities were analyzed by one-way Welch-ANOVA followed by Games-Howell post hoc test (α = 0.05). C. albicans, MSSA and MRSA were able to adhere and to form biofilm in both single or mixed cultures. In general, all microorganisms in both growth conditions showed a gradual increase in the number of cells and metabolic activity over time, reaching peak values between 12 h and 48 h (ρ<0.05). C. albicans single- and dual-biofilms had significantly higher total biomass values (ρ<0.05) than single biofilms of bacteria. Except for single MRSA biofilms, all microorganisms in both growth conditions secreted proteinase and phospholipase-C. SEM images revealed extensive adherence of bacteria to hyphal elements of C. albicans. C. albicans, MSSA, and MRSA can co-exist in biofilms without antagonism and in an apparent synergistic effect, with bacteria cells preferentially associated to C. albicans hyphal forms.

Metastatic prostate cancer-associated P62 inhibits autophagy flux and promotes epithelial to mesenchymal transition by sustaining the level of HDAC6.

PubMed

Jiang, Xianhan; Huang, Yiqiao; Liang, Xue; Jiang, Funeng; He, Yongzhong; Li, Tian; Xu, Guibin; Zhao, Haibo; Yang, Weiqing; Jiang, Ganggang; Su, Zhengming; Jiang, Lingke; Liu, Leyuan

2018-05-01

P62 (also named sequestosome-1, SQSTM1) is involved in autophagy regulation through multiple pathways. It interacts with autophagosomes-associated LC3-II and ubiquitinated protein aggregates to engulf the aggregates in autophagosomes, interacts with HDAC6 to inhibit its deacetylase activity to maintain the levels of acetylated α-tubulin and stabilities of microtubules to enhance autophagosome trafficking, and regulates autophagy initiation and cell survival. We performed immunohistochemistry staining of P62 in prostate tissues from prostate cancer patients and found that levels of P62 in patients with prostate adenocarcinomas (PCA) are significantly higher than those in patients with benign prostate hyperplasia (BPH). High levels of P62 predict high tumor grade and high intensity of metastasis. We created prostate cancer cell lines stably overexpressing P62 and then suppress the expression of P62 in the cell line stably overexpressing P62 with CRISPR technology. Cell proliferation assay with crystal violet, cell migration assay, cell invasion assay, Western blot analysis, and confocal fluorescent microscopy were conducted to test the impact of altered levels of P62 on the growth, migration, invasion, epithelial-to-mesenchymal transition, autophagy flux, HDAC6 activity, and microtubular acetylation of cancer cells. P62 increased the levels of HDAC6 and reduced the acetylation of α-tubulin and the stability of microtubules. Consequently, high levels of P62 caused a promotion of epithelial-to-mesenchymal transition in addition to an impairment of autophagy flux, and further led to an enhancement of proliferation, migration, and invasion of prostate cancer cells. P62 promotes metastasis of PCA by sustaining the level of HDAC6 to inhibit autophagy and promote epithelial-to-mesenchymal transition. © 2018 Wiley Periodicals, Inc.

Characterization of biofilm formation by clinical isolates of Mycobacterium avium.

PubMed

Carter, George; Wu, Martin; Drummond, Daryl C; Bermudez, Luiz E

2003-09-01

Mycobacterium avium is an environmental organism encountered in natural and urban water sources as well as soil. M. avium biofilm has recently been identified on sauna walls and in city water pipes and might have a role in the survival of virulent strains in the environment and in the host. To characterize the M. avium biofilm, an in vitro model was adapted wherein biofilm develops on a PVC surface. Biofilm was detected by staining with crystal violet and visualization by optical microscopy and quantified by A(570). M. avium strains MAC 101, MAC 100, MAC 104, MAC 109, MAC A5 and MAC 5501 (all isolated from the blood of AIDS patients) were used in the assays. Biofilm formation was dependent on the presence of Ca(2+), Mg(2+) or Zn(2+) ions in the water, with the maximal effect seen at a concentration of 1 micro M. The presence of 2 % glucose and peptone as sources of carbon increased the formation of biofilm, while this was partially inhibited by humic acid. Since sliding motility has been associated with the amount of glycopeptidolipid (GPL), TLC was used to determine the presence of GPL. The supernatant of a biofilm-forming culture induced formation of a stable biofilm and amikacin blocked the establishment of biofilm by M. avium strains at subinhibitory concentrations. Bacteria in the biofilm were more resistant to chlorine as well as to exposure to potassium monopersulfate and chloroheximide acetate than were planktonic bacteria. Identification of M. avium genes involved in biofilm formation and further studies of the effect of antimicrobials on the establishment of biofilm may identify approaches for inhibiting M. avium biofilm formation and colonization.

Substance P reduces TNF-α-induced apoptosis in human tenocytes through NK-1 receptor stimulation.

PubMed

Backman, Ludvig J; Eriksson, Daniella E; Danielson, Patrik

2014-10-01

It has been hypothesised that an upregulation of the neuropeptide substance P (SP) and its preferred receptor, the neurokinin-1 receptor (NK-1 R), is a causative factor in inducing tenocyte hypercellularity, a characteristic of tendinosis, through both proliferative and antiapoptotic stimuli. We have demonstrated earlier that SP stimulates proliferation of human tenocytes in culture. The aim of this study was to investigate whether SP can mediate an antiapoptotic effect in tumour necrosis factor-α (TNF-α)-induced apoptosis of human tenocytes in vitro. A majority (approximately 75%) of tenocytes in culture were immunopositive for TNF Receptor-1 and TNF Receptor-2. Exposure of the cells to TNF-α significantly decreased cell viability, as shown with crystal violet staining. TNF-α furthermore significantly increased the amount of caspase-10 and caspase-3 mRNA, as well as both BID and cleaved-poly ADP ribosome polymerase (c-PARP) protein. Incubation of SP together with TNF-α resulted in a decreased amount of BID and c-PARP, and in a reduced lactate dehydrogenase release, as compared to incubation with TNF-α alone. The SP effect was blocked with a NK-1 R inhibitor. This study shows that SP, through stimulation of the NK-1 R, has the ability to reduce TNF-α-induced apoptosis of human tenocytes. Considering that SP has previously been shown to stimulate tenocyte proliferation, the study confirms SP as a potent regulator of cell-turnover in tendon tissue, capable of stimulating hypercellularity through different mechanisms. This gives further support for the theory that the upregulated amount of SP seen in tendinosis could contribute to hypercellularity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Effects of alcohols, povidone-iodine and hydrogen peroxide on biofilms of Staphylococcus epidermidis.

PubMed

Presterl, Elisabeth; Suchomel, Miranda; Eder, Michaela; Reichmann, Sonja; Lassnigg, Andrea; Graninger, Wolfgang; Rotter, Manfred

2007-08-01

To test the effects of several biocides [N-propanol, a commercially available propanol/ethanol/chlorhexidine mixture, polyvinylpyrolidone (povidone-iodine) and hydrogen peroxide] on established biofilms of Staphylococcus epidermidis isolated from patients with cardiac implant infections and catheter-related bacteraemia. Biofilms were grown in microtitre plates for 24 h, dyed and stained with Crystal Violet. The mean optical density (OD) and the OD ratio (ODr=OD of the treated biofilm/OD of the untreated biofilm) were used for quantification. Biofilms were incubated with 60% (v/v) N-propanol, the mixture of propanol/ethanol/chlorhexidine, hydrogen peroxide at three concentrations (0.5%, 3% and 5%, v/v) and povidone-iodine for 1, 5, 15, 30 and 60 min. Unstained biofilms were sonicated and plated on Columbia agar for time-kill curves. S. epidermidis skin isolates from healthy volunteers were used as controls. Biofilm ODs of the clinical S. epidermidis isolates and the isolates from the healthy volunteers were significantly different (1.17+/-0.512 versus 0.559+/-0.095, respectively; mean+/-SD) (P<0.01). No viable S. epidermidis was detected in biofilms treated with the alcohols, N-propanol or the propanol/ethanol/chlorhexidine mixture. Incubation with povidone-iodine and hydrogen peroxide 3% and 5% led to a log reduction of the viable cells of >5 after incubation for 5 min, however, up to 10(3) viable cells were detected in four isolates after 30 min of incubation with povidone-iodine. S. epidermidis obtained from infected implants forms thicker biofilms than that of healthy volunteers. Hydrogen peroxide, at a concentration of 3% and 5%, and alcohols rapidly eradicate S. epidermidis biofilms, whereas povidone-iodine is less effective.

In Vitro Effects of Polyphosphate against Prevotella intermedia in Planktonic Phase and Biofilm.

PubMed

Jang, Eun-Young; Kim, Minjung; Noh, Mi Hee; Moon, Ji-Hoi; Lee, Jin-Yong

2016-02-01

Polyphosphate (polyP) has gained a wide interest in the food industry due to its potential as a decontaminating agent. In this study, we examined the effect of sodium tripolyphosphate (polyP3; Na5P3O10) against planktonic and biofilm cells of Prevotella intermedia, a major oral pathogen. The MIC of polyP3 against P. intermedia ATCC 49046 determined by agar dilution method was 0.075%, while 0.05% polyP3 was bactericidal against P. intermedia in time-kill analysis performed using liquid medium. A crystal violet binding assay for the assessment of biofilm formation by P. intermedia showed that sub-MICs of polyP3 significantly decreased biofilm formation. Under the scanning electron microscope, decreased numbers of P. intermedia cells forming the biofilms were observed when the bacterial cells were incubated with 0.025% or higher concentrations of polyP3. Assessment of biofilm viability with LIVE/DEAD staining and viable cell count methods showed that 0.05% or higher concentrations of polyP3 significantly decreased the viability of the preformed biofilms in a concentration-dependent manner. The zone sizes of alpha-hemolysis formed on horse blood agar produced by P. intermedia were decreased in the presence of polyP3. The expression of the genes encoding hemolysins and the genes of the hemin uptake (hmu) locus was downregulated by polyP3. Collectively, our results show that polyP is an effective antimicrobial agent against P. intermedia in biofilms as well as planktonic phase, interfering with the process of hemin acquisition by the bacterium. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Liquiritin suppresses UVB‑induced skin injury through prevention of inflammation, oxidative stress and apoptosis through the TLR4/MyD88/NF‑κB and MAPK/caspase signaling pathways.

PubMed

Li, Xiao-Qing; Cai, Li-Min; Liu, Jing; Ma, Yan-Li; Kong, Ying-Hui; Li, He; Jiang, Ming

2018-06-05

Solar ultraviolet B (UVB) radiation is known to trigger inflammation, oxidative stress and apoptotic responses through various signaling pathways, which eventually lead to skin cancer. The present study investigated whether liquiritin suppresses UVB‑induced skin injury in vivo and in vitro using SKH‑1 hairless mice and HACAT cells, respectively. The animals were exposed to UVB irradiation (180 mJ/cm2) for 20 min, followed by liquiritin treatment. The findings indicated that UVB exposure resulted in the excessive release of pro‑inflammatory cytokines, including interleukin (IL)‑1β, tumor necrosis factor (TNF)‑α, IL‑18, IL‑6 and cyclooxygenase (COX)2, which were dependent on the toll‑like receptor (TLR)4/myeloid differentiation factor 88 (MyD88)/nuclear factor‑κB (NF‑κB) signaling pathway. Oxidative stress was also observed, evidenced by reduced antioxidants and elevated oxidants. Apoptosis, examined using terminal deoxynucleotidyl transferase dUTP nick end labeling and crystal violet staining, suggested that UVB irradiation caused cell death in vivo and in vitro, which was closely associated with p38/c‑Jun N‑terminal kinase and caspase activity. Of note, liquiritin treatment in mice and cells exposed to UVB showed reduced inflammatory response, oxidative stress and apoptosis through inhibiting the activation of TLR4/MyD88/NF‑κB mitogen‑activated protein kinases and caspase pathways, and downregulating the release of oxidants. Overall, the data revealed that liquiritin may be a useful compound against UVB‑induced skin injury.

Effects of Lectins on initial attachment of cariogenic Streptococcus mutans.

PubMed

Ito, Takashi; Yoshida, Yasuhiro; Shiota, Yasuyoshi; Ito, Yuki; Yamamoto, Tadashi; Takashiba, Shogo

2018-02-01

Oral bacteria initiate biofilm formation by attaching to tooth surfaces via an interaction of a lectin-like bacterial protein with carbohydrate chains on the pellicle. This study aimed to find naturally derived lectins that inhibit the initial attachment of a cariogenic bacterial species, Streptococcus mutans (S. mutans), to carbohydrate chains in saliva in vitro. Seventy kinds of lectins were screened for candidate motifs that inhibit the attachment of S. mutans ATCC 25175 to a saliva-coated culture plate. The inhibitory effect of the lectins on attachment of the S. mutans to the plates was quantified by crystal violet staining, and the biofilm was observed under a scanning electron microscope (SEM). Surface plasmon resonance (SPR) analysis was performed to examine the binding of S. mutans to carbohydrate chains and the binding of candidate lectins to carbohydrate chains, respectively. Moreover, binding assay between the biotinylated-lectins and the saliva components was conducted to measure the lectin binding. Lectins recognizing a salivary carbohydrate chain, Galβ1-3GalNAc, inhibited the binding of S. mutans to the plate. In particular, Agaricus bisporus agglutinin (ABA) markedly inhibited the binding. This inhibition was confirmed by SEM observation. SPR analysis indicated that S. mutans strongly binds to Galβ1-3GalNAc, and ABA binds to Galβ1-3GalNAc. Finally, the biotinylated Galβ1-3GalNAc-binding lectins including ABA demonstrated marked binding to the saliva components. These results suggest that ABA lectin inhibited the attachment of S. mutans to Galβ1-3GalNAc in saliva and ABA can be useful as a potent inhibitor for initial attachment of oral bacteria and biofilm formation.

Carcinostatic effects of platinum nanocolloid combined with gamma irradiation on human esophageal squamous cell carcinoma.

PubMed

Li, Qiang; Tanaka, Yoshiharu; Saitoh, Yasukazu; Tanaka, Hiroshi; Miwa, Nobuhiko

2015-04-15

To explore the carcinostatic effects of platinum nanocolloid (Pt-nc) combined with gamma rays on human esophageal squamous cell carcinoma (ESCC). ESCC-derived KYSE-70 cells were treated with various concentrations of Pt-nc and/or gamma irradiation, and subsequently cultured in phenol red free DMEM with 10% FBS for 48 h. The proliferative status of the KYSE-70 cells was evaluated using trypan blue dye exclusion and WST-8 assays. Cellular and nucleic morphological aspects were evaluated using crystal violet and Hoechst 33342 stainings, respectively. Radiosensitivity was quantified by a cell viability assay, and the activated form of caspase-3, a characteristic apoptosis-related protein, was detected by Western blotting. Although single treatment with either Pt-nc or gamma irradiation could slightly inhibit the growth of the KYSE-70 cells, their combination exerted remarkable carcinostatic effects in a manner dependent on either Pt-nc concentrations or gamma ray doses, compared with the effect of each treatment alone (p<0.05). By fluorescence micrographic observation, the KYSE-70 cells that were treated with Pt-nc and subsequently irradiated with gamma rays, were shown to undergo distinct apoptotic morphological changes. The carcinostatic effect of gamma rays at 7 Gy without Pt-nc was approximately equal to that when 3-Gy irradiation was combined with 100 ppm Pt-nc or that 5-Gy irradiation was combined with 50 ppm Pt-nc. Pt-nc in combination with gamma rays may exert a cooperative effect through platinum- or gamma ray-induced apoptosis resulting in the inhibition of growth of cancer cells, while concurrently enabling the lowering of the radiative dose. Copyright © 2015 Elsevier Inc. All rights reserved.

Impact of persistent and nonpersistent generic Escherichia coli and Salmonella sp. recovered from a beef packing plant on biofilm formation by E. coli O157.

PubMed

Visvalingam, J; Ells, T C; Yang, X

2017-12-01

To examine the influence of meat plant Escherichia coli and Salmonella sp. isolates on E. coli O157 biofilm formation. Biofilm formation was quantified by crystal violet staining (A 570 nm ) and viable cell numbers for up to 6 days at 15°C. All five persistent E. coli genotypes formed strong biofilms when cultured alone or co-cultured with E. coli O157, with A 570 nm values reaching ≥4·8 at day 4, while only two of five nonpersistent genotypes formed such biofilms. For E. coli O157:H7 co-culture biofilms with E. coli genotypes 136 and 533, its numbers were ≥1·5 and ≥1 log CFU per peg lower than those observed for its mono-culture biofilm at days 2 and 4, respectively. The number of E. coli O157:NM in similar co-culture biofilms was 1 log CFU per peg lower than in its mono-culture biofilm at day 4 and 6, respectively. Salmonella sp. lowered the number of E. coli O157:NM by 0·5 log unit, once, at day 6. Generic E. coli may outcompete E. coli O157 strains while establishing biofilms. Findings advance knowledge regarding inter-strain competition for a similar ecological niche and may aid development of biocontrol strategies for E. coli O157 in food processing environments. © 2017 Her Majesty the Queen in Right of Canada. Journal of Applied Microbiology © 2017 The Society for Applied Microbiology Reproduced with the permission of the Minister of the Department of Agriculture and Agri-Food Canada.

Inhibition of Hyphal Growth of Azole-Resistant Strains of Candida albicans by Triazole Antifungal Agents in the Presence of Lactoferrin-Related Compounds

PubMed Central

Wakabayashi, Hiroyuki; Abe, Shigeru; Teraguchi, Susumu; Hayasawa, Hirotoshi; Yamaguchi, Hideyo

1998-01-01

The effects of bovine lactoferrin (LF) or the LF-derived antimicrobial peptide lactoferricin B (LFcin B) on the growth of Candida albicans hyphae, including those of three azole-resistant strains, were investigated by a crystal violet staining method. The hyphae of two highly azole-resistant strains were more susceptible to inhibition by LF or LFcin B than the azole-susceptible strains tested. One moderately azole-resistant strain was defective in the formation of hyphae and showed a susceptibility to LF greater than that of the susceptible strains but a susceptibility to LFcin B similar to that of the susceptible strains. The highly azole-resistant strain TIMM3317 showed trailing growth in the presence of fluconazole or itraconazole, while the extent of growth was reduced by the addition of LF or LFcin B at a sub-MIC. Thus, the addition of LF or LFcin B at a sub-MIC resulted in a substantial decrease in the MICs of fluconazole and itraconazole for two highly azole-resistant strains; e.g., the MIC of fluconazole for TIMM3317 was shifted from >256 to 0.25 μg/ml by LF, but the MICs were not decreased for the susceptible strains. The combination effects observed with triazoles and LF-related compounds in the case of the two highly azole-resistant strains were confirmed to be synergistic by the fractional inhibitory concentration index. These results demonstrate that for some azole-resistant C. albicans strains, LF-related compounds combined with triazoles can inhibit the growth of hyphae, an important form of this organism in pathogenesis. PMID:9660988

Preclinical Testing of an Oncolytic Parvovirus: Standard Protoparvovirus H-1PV Efficiently Induces Osteosarcoma Cell Lysis In Vitro.

PubMed

Geiss, Carsten; Kis, Zoltán; Leuchs, Barbara; Frank-Stöhr, Monika; Schlehofer, Jörg R; Rommelaere, Jean; Dinsart, Christiane; Lacroix, Jeannine

2017-10-17

Osteosarcoma is the most frequent malignant disease of the bone. On the basis of early clinical experience in the 1960s with H-1 protoparvovirus (H-1PV) in osteosarcoma patients, this effective oncolytic virus was selected for systematic preclinical testing on various osteosarcoma cell cultures. A panel of five human osteosarcoma cell lines (CAL 72, H-OS, MG-63, SaOS-2, U-2OS) was tested. Virus oncoselectivity was confirmed by infecting non-malignant human neonatal fibroblasts and osteoblasts used as culture models of non-transformed mesenchymal cells. H-1PV was found to enter osteosarcoma cells and to induce viral DNA replication, transcription of viral genes, and translation to viral proteins. After H-1PV infection, release of infectious viral particles from osteosarcoma cells into the supernatant indicated successful viral assembly and egress. Crystal violet staining revealed progressive cytomorphological changes in all osteosarcoma cell lines. Infection of osteosarcoma cell lines with the standard H-1PV caused an arrest of the cell cycle in the G2 phase, and these lines had a limited capacity for standard H-1PV virus replication. The cytotoxicity of wild-type H-1PV virus towards osteosarcoma cells was compared in vitro with that of two variants, Del H-1PV and DM H-1PV, previously described as fitness variants displaying higher infectivity and spreading in human transformed cell lines of different origins. Surprisingly, wild-type H-1PV displayed the strongest cytostatic and cytotoxic effects in this analysis and thus seems the most promising for the next preclinical validation steps in vivo.

Leptin promotes wound healing in the oral mucosa.

PubMed

Umeki, Hirochika; Tokuyama, Reiko; Ide, Shinji; Okubo, Mitsuru; Tadokoro, Susumu; Tezuka, Mitsuki; Tatehara, Seiko; Satomura, Kazuhito

2014-01-01

Leptin, a 16 kDa circulating anti-obesity hormone, exhibits many physiological properties. Recently, leptin was isolated from saliva; however, its function in the oral cavity is still unclear. In this study, we investigated the physiological role of leptin in the oral cavity by focusing on its effect on wound healing in the oral mucosa. Immunohistochemical analysis was used to examine the expression of the leptin receptor (Ob-R) in human/rabbit oral mucosa. To investigate the effect of leptin on wound healing in the oral mucosa, chemical wounds were created in rabbit oral mucosa, and leptin was topically administered to the wound. The process of wound repair was histologically observed and quantitatively analyzed by measuring the area of ulceration and the duration required for complete healing. The effect of leptin on the proliferation, differentiation and migration of human oral mucosal epithelial cells (RT7 cells) was investigated using crystal violet staining, reverse transcription polymerase chain reaction (RT-PCR) and a wound healing assay, respectively. Ob-R was expressed in spinous/granular cells in the epithelial tissue and vascular endothelial cells in the subepithelial connective tissue of the oral mucosa. Topical administration of leptin significantly promoted wound healing and shortened the duration required for complete healing. Histological analysis of gingival tissue beneath the ulceration showed a denser distribution of blood vessels in the leptin-treated group. Although the proliferation and differentiation of RT7 cells were not affected by leptin, the migration of these cells was accelerated in the presence of leptin. Topically administered leptin was shown to promote wound healing in the oral mucosa by accelerating epithelial cell migration and enhancing angiogenesis around the wounded area. These results strongly suggest that topical administration of leptin may be useful as a treatment to promote wound healing in the oral mucosa.

Growth and adherence of Staphylococcus aureus were enhanced through the PGE2 produced by the activated COX-2/PGE2 pathway of infected oral epithelial cells

PubMed Central

Wang, Yuxia; Ren, Biao; Zhou, Xuedong; Liu, Shiyu; Zhou, Yujie; Li, Bolei; Jiang, Yaling; Li, Mingyun; Feng, Mingye

2017-01-01

Staphylococcus aureus is a major pathogen of varieties of oral mucous infection. Prostaglandin E2 (PGE2) is a pro-inflammatory factor and Cyclooxygenase 2 (COX-2) is a critical enzyme of PGE2 biosynthesis. The purpose of this study is to investigate whether Staphylococcus aureus can increase PGE2 production of oral epithelial cells and how PGE2 functions in the growth and adherence of Staphylococcus aureus. mRNA levels of COX-2, fnbpA and fnbpB were estimated by quantitative PCR. PGE2 production was measured by Enzyme Linked Immunosorbent Assay (ELISA). The binding biomass of Staphylococcus aureus to human fibronectin was investigated by crystal violet staining and confocal laser scanning microscopy and the adherent force was measured by atomic force microscope (AFM). The COX-2 mRNA level and PGE2 production were increased by Staphylococcus aureus. PGE2 promoted the growth and biofilm formation of Staphylococcus aureus, enhanced the attachment of Staphylococcus aureus to the human fibronectin as well as to the HOK cells. The transcription of fnbpB was up-regulated by PGE2 in both early and middle exponential phase but not fnbpA. These results suggest that the activation of COX-2/PGE2 pathway in oral epithelial cell by Staphylococcus aureus can in turn facilitate the growth and the ability to adhere of the pathogen. These findings uncover a new function of PGE2 and may lead to the potential of COX-2/PGE2 targeting in the therapy of inflammation and cancer in both which the COX-2/PGE2 pathway were observed activated. PMID:28472126

Growth and adherence of Staphylococcus aureus were enhanced through the PGE2 produced by the activated COX-2/PGE2 pathway of infected oral epithelial cells.

PubMed

Wang, Yuxia; Ren, Biao; Zhou, Xuedong; Liu, Shiyu; Zhou, Yujie; Li, Bolei; Jiang, Yaling; Li, Mingyun; Feng, Mingye; Cheng, Lei

2017-01-01

Staphylococcus aureus is a major pathogen of varieties of oral mucous infection. Prostaglandin E2 (PGE2) is a pro-inflammatory factor and Cyclooxygenase 2 (COX-2) is a critical enzyme of PGE2 biosynthesis. The purpose of this study is to investigate whether Staphylococcus aureus can increase PGE2 production of oral epithelial cells and how PGE2 functions in the growth and adherence of Staphylococcus aureus. mRNA levels of COX-2, fnbpA and fnbpB were estimated by quantitative PCR. PGE2 production was measured by Enzyme Linked Immunosorbent Assay (ELISA). The binding biomass of Staphylococcus aureus to human fibronectin was investigated by crystal violet staining and confocal laser scanning microscopy and the adherent force was measured by atomic force microscope (AFM). The COX-2 mRNA level and PGE2 production were increased by Staphylococcus aureus. PGE2 promoted the growth and biofilm formation of Staphylococcus aureus, enhanced the attachment of Staphylococcus aureus to the human fibronectin as well as to the HOK cells. The transcription of fnbpB was up-regulated by PGE2 in both early and middle exponential phase but not fnbpA. These results suggest that the activation of COX-2/PGE2 pathway in oral epithelial cell by Staphylococcus aureus can in turn facilitate the growth and the ability to adhere of the pathogen. These findings uncover a new function of PGE2 and may lead to the potential of COX-2/PGE2 targeting in the therapy of inflammation and cancer in both which the COX-2/PGE2 pathway were observed activated.

Identification of pink-pigmented bacteria isolated from environmental water samples and their biofilm formation abilities.

PubMed

Furuhata, Katsunori; Kato, Yuko; Goto, Keiichi; Saitou, Keiko; Sugiyama, Jun-Ichi; Hara, Motonobu; Fukuyama, Masahumi

2008-06-01

Sixty-seven strains of pink-pigmented bacteria, which were isolated from environmental water samples collected nationwide, were identified by partial 16S rDNA sequence analysis. In addition, the biofilm formation ability of the isolates was experimentally investigated. We could identify only 2 strains at the species level: Pedobacter roseus HS-38 and Runella slithyformis HS-77. The results showed that of the strains tested, 22 strains (32.8%) were Pedobacter spp., which was most frequently identified, followed by 19 strains (28.4%) of Arcicella spp., 16 strains (23.9%) of Deinococcus spp., 5 strains (7.5%) of Roseomonas spp., 4 strains (6.0%) of Flectobacillus spp. and 1 strain (1.5%) of Runella sp. Most isolates showed low similarity values to previously known species, and they were found to be novel species. At a result, it was difficult to identify environmental water-derived pink-pigmented bacteria at the species level. On the other hand, when we measured the absorbance by the crystal violet staining to examine the quantities of biofilm formation of these strains, fifty-five (82.0%) of the 67 isolates formed biofilm. The absorbance of Deinococcus sp. HS-75 was the highest (3.56). When comparing the absorbance values among the genera, Roseomonas spp. showed the highest absorbance (mean:1.62), followed by Deinococcus spp. (mean: 1.03), and Arcicella spp. (mean: 1.01). Strains of Flectobacillus spp. (mean: 0.48) and Pedobacter spp. (mean: 0.42) showed lower absorbance values. As above, it was shown that, at the species level, the pink-pigmented bacteria in the water in the Japanese environment had various levels of ability to form biofilm.

Reinjury risk of nano-calcium oxalate monohydrate and calcium oxalate dihydrate crystals on injured renal epithelial cells: aggravation of crystal adhesion and aggregation

PubMed Central

Gan, Qiong-Zhi; Sun, Xin-Yuan; Bhadja, Poonam; Yao, Xiu-Qiong; Ouyang, Jian-Ming

2016-01-01

Background Renal epithelial cell injury facilitates crystal adhesion to cell surface and serves as a key step in renal stone formation. However, the effects of cell injury on the adhesion of nano-calcium oxalate crystals and the nano-crystal-induced reinjury risk of injured cells remain unclear. Methods African green monkey renal epithelial (Vero) cells were injured with H2O2 to establish a cell injury model. Cell viability, superoxide dismutase (SOD) activity, malonaldehyde (MDA) content, propidium iodide staining, hematoxylin–eosin staining, reactive oxygen species production, and mitochondrial membrane potential (Δψm) were determined to examine cell injury during adhesion. Changes in the surface structure of H2O2-injured cells were assessed through atomic force microscopy. The altered expression of hyaluronan during adhesion was examined through laser scanning confocal microscopy. The adhesion of nano-calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) crystals to Vero cells was observed through scanning electron microscopy. Nano-COM and COD binding was quantitatively determined through inductively coupled plasma emission spectrometry. Results The expression of hyaluronan on the cell surface was increased during wound healing because of Vero cell injury. The structure and function of the cell membrane were also altered by cell injury; thus, nano-crystal adhesion occurred. The ability of nano-COM to adhere to the injured Vero cells was higher than that of nano-COD crystals. The cell viability, SOD activity, and Δψm decreased when nano-crystals attached to the cell surface. By contrast, the MDA content, reactive oxygen species production, and cell death rate increased. Conclusion Cell injury contributes to crystal adhesion to Vero cell surface. The attached nano-COM and COD crystals can aggravate Vero cell injury. As a consequence, crystal adhesion and aggregation are enhanced. These findings provide further insights into kidney stone formation. PMID:27382277

Electrophoresis Gel Quantification with a Flatbed Scanner and Versatile Lighting from a Screen Scavenged from a Liquid Crystal Display (LCD) Monitor

ERIC Educational Resources Information Center

Yeung, Brendan; Ng, Tuck Wah; Tan, Han Yen; Liew, Oi Wah

2012-01-01

The use of different types of stains in the quantification of proteins separated on gels using electrophoresis offers the capability of deriving good outcomes in terms of linear dynamic range, sensitivity, and compatibility with specific proteins. An inexpensive, simple, and versatile lighting system based on liquid crystal display backlighting is…

Hydrogen bonding interactions and supramolecular assemblies in 2-amino guanidinium 4-methyl benzene sulphonate crystal structure: Hirshfeld surfaces and computational calculations

NASA Astrophysics Data System (ADS)

Muthuraja, P.; Joselin Beaula, T.; Balachandar, S.; Bena Jothy, V.; Dhandapani, M.

2017-10-01

2-aminoguanidinium 4-methyl benzene sulphonate (AGMS), an organic compound with big assembly of hydrogen bonding interactions was crystallized at room temperature. The structure of the compound was confirmed by FT-IR, NMR and single crystal X-ray diffraction analysis. Numerous hydrogen bonded interactions were found to form supramolecular assemblies in the molecular structure. Fingerprint plots of Hirshfeld surface analysis spells out the interactions in various directions. The molecular structure of AGMS was optimised by HF, MP2 and DFT (B3LYP and CAM-B3LYP) methods at 6-311G (d,p) basis set and the geometrical parameters were compared. Electrostatic potential calculations of the reactants and product confirm the transfer of proton. Optical properties of AGMS were ascertained by UV-Vis absorbance and reflectance spectra. The band gap of AGMS is found to be 2.689 eV. Due to numerous hydrogen bonds, the crystal is thermally stable up to 200 °C. Hyperconjugative interactions which are responsible for the second hyperpolarizabilities were accounted by NBO analysis. Static and frequency dependent optical properties were calculated at HF and DFT methods. The hyperpolarizabilities of AGMS increase rapidly at frequencies 0.0428 and 0.08 a.u. compared to static one. The compound exhibits violet and blue emission.

Removal of Micrometer Size Morphological Defects and Enhancement of Ultraviolet Emission by Thermal Treatment of Ga-Doped ZnO Nanostructures

PubMed Central

Manzoor, Umair; Kim, Do K.; Islam, Mohammad; Bhatti, Arshad S.

2014-01-01

Mixed morphologies of Ga-doped Zinc Oxide (ZnO) nanostructures are synthesized by vapor transport method. Systematic scanning electron microscope (SEM) studies of different morphologies, after periodic heat treatments, gives direct evidence of sublimation. SEM micrographs give direct evidence that morphological defects of nanostructures can be removed by annealing. Ultra Violet (UV) and visible emission depends strongly on the annealing temperatures and luminescent efficiency of UV emission is enhanced significantly with each subsequent heat treatment. X-Ray diffraction (XRD) results suggest that crystal quality improved by annealing and phase separation may occur at high temperatures. PMID:24489725

Removal of micrometer size morphological defects and enhancement of ultraviolet emission by thermal treatment of Ga-doped ZnO nanostructures.

PubMed

Manzoor, Umair; Kim, Do K; Islam, Mohammad; Bhatti, Arshad S

2014-01-01

Mixed morphologies of Ga-doped Zinc Oxide (ZnO) nanostructures are synthesized by vapor transport method. Systematic scanning electron microscope (SEM) studies of different morphologies, after periodic heat treatments, gives direct evidence of sublimation. SEM micrographs give direct evidence that morphological defects of nanostructures can be removed by annealing. Ultra Violet (UV) and visible emission depends strongly on the annealing temperatures and luminescent efficiency of UV emission is enhanced significantly with each subsequent heat treatment. X-Ray diffraction (XRD) results suggest that crystal quality improved by annealing and phase separation may occur at high temperatures.

Localization microscopy of DNA in situ using Vybrant(®) DyeCycle™ Violet fluorescent probe: A new approach to study nuclear nanostructure at single molecule resolution.

PubMed

Żurek-Biesiada, Dominika; Szczurek, Aleksander T; Prakash, Kirti; Mohana, Giriram K; Lee, Hyun-Keun; Roignant, Jean-Yves; Birk, Udo J; Dobrucki, Jurek W; Cremer, Christoph

2016-05-01

Higher order chromatin structure is not only required to compact and spatially arrange long chromatids within a nucleus, but have also important functional roles, including control of gene expression and DNA processing. However, studies of chromatin nanostructures cannot be performed using conventional widefield and confocal microscopy because of the limited optical resolution. Various methods of superresolution microscopy have been described to overcome this difficulty, like structured illumination and single molecule localization microscopy. We report here that the standard DNA dye Vybrant(®) DyeCycle™ Violet can be used to provide single molecule localization microscopy (SMLM) images of DNA in nuclei of fixed mammalian cells. This SMLM method enabled optical isolation and localization of large numbers of DNA-bound molecules, usually in excess of 10(6) signals in one cell nucleus. The technique yielded high-quality images of nuclear DNA density, revealing subdiffraction chromatin structures of the size in the order of 100nm; the interchromatin compartment was visualized at unprecedented optical resolution. The approach offers several advantages over previously described high resolution DNA imaging methods, including high specificity, an ability to record images using a single wavelength excitation, and a higher density of single molecule signals than reported in previous SMLM studies. The method is compatible with DNA/multicolor SMLM imaging which employs simple staining methods suited also for conventional optical microscopy. Copyright © 2016. Published by Elsevier Inc.

HALE STAIN FOR SIALIC ACID-CONTAINING MUCINS. ADAPTATION TO ELECTRON MICROSCOPY.

PubMed

GASIC, G; BERWICK, L

1963-10-01

The feasibility of using the Hale stain to identify cellular sialic acid-containing mucins by electron microscopy was investigated. Three kinds of mouse ascites tumor cells were fixed in neutral buffered formalin, exposed to fresh colloidal ferric oxide, treated with potassium ferrocyanide, imbedded in Selectron, and sectioned for electron microscopy. Additional staining with uranyl acetate and potassium permanganate was done after sectioning in order to increase contrast. Those cells known to be coated with sialomucin showed deposits of electron-opaque ferric ferrocyanide crystals in the areas where sialomucin concentrations were expected. When these cells were treated with neuraminidase beforehand, these deposits did not appear. It was concluded that, with the precautions and modifications described, the Hale stain can be successfully combined with electron microscopy to identify sialomucin.

Albanian violets of the section Melanium, their morphological variability, genetic similarity and their adaptations to serpentine or chalk soils.

PubMed

Słomka, Aneta; Godzik, Barbara; Szarek-Łukaszewska, Grażyna; Shuka, Lulëzim; Hoef-Emden, Kerstin; Bothe, Hermann

2015-02-01

Violets of the section Melanium from Albanian serpentine and chalk soils were examined for their taxonomic affiliations, their ability to accumulate heavy metals and their colonization by arbuscular mycorrhizal fungi (AMF). The sequence analysis of the ITS1-5.8S rDNA-ITS2 region showed that all the sampled six Albanian violets grouped between Viola lutea and Viola arvensis, but not with Viola tricolor. The fine resolution of the ITS sequences was not sufficient for a further delimitation of the Albanian violets within the V. lutea-V. arvensis clade. Therefore, the Albanian violets were classified by a set of morphological characters. Viola albanica, Viola dukadjinica and Viola raunsiensis from serpentine soils as well as Viola aetolica from a chalk meadow were unambiguously identified, whereas the samples of Viola macedonica showed high morphological variability. All the violets, in both roots and shoots contained less than or similar levels of heavy metals as their harboring soils, indicating that they were heavy metal excluders. All the violets were strongly colonized by AMF with the remarkable exception of V. albanica. This violet lived as a scree creeper in shallow serpentine soil where the concentration of heavy metals was high but those of P, K and N were scarce. Copyright © 2014 Elsevier GmbH. All rights reserved.

A combination of cis-2-decenoic acid and antibiotics eradicates pre-established catheter-associated biofilms.

PubMed

Rahmani-Badi, Azadeh; Sepehr, Shayesteh; Mohammadi, Parisa; Soudi, Mohammad Reza; Babaie-Naiej, Hamta; Fallahi, Hossein

2014-11-01

The catheterized urinary tract provides ideal conditions for the development of biofilm populations. Catheter-associated urinary tract infections (CAUTIs) are recalcitrant to existing antimicrobial treatments; therefore, established biofilms are not eradicated completely after treatment and surviving biofilm cells will carry on the infection. Cis-2-decenoic acid (CDA), an unsaturated fatty acid, is capable of inhibiting biofilm formation by Pseudomonas aeruginosa and of inducing the dispersion of established biofilms by multiple types of micro-organisms. Here, the ability of CDA to induce dispersal in pre-established single- and dual-species biofilms formed by Escherichia coli and Klebsiella pneumoniae was measured by using both semi-batch and continuous cultures bioassays. Removal of the biofilms by combined CDA and antibiotics (ciprofloxacin or ampicillin) was evaluated using microtitre plate assays (crystal violet staining). The c.f.u. counts were determined to assess the potential of combined CDA treatments to kill and eradicate pre-established biofilms formed on catheters. The effects of combined CDA treatments on biofilm surface area and bacteria viability were evaluated using fluorescence microscopy, digital image analysis and live/dead staining. To investigate the ability of CDA to prevent biofilm formation, single and mixed cultures were grown in the presence and absence of CDA. Treatment of pre-established biofilms with only 310 nM CDA resulted in at least threefold increase in the number of planktonic cells in all cultures tested. Whilst none of the antibiotics alone exerted a significant effect on c.f.u. counts and percentage of surface area covered by the biofilms, combined CDA treatments led to at least a 78% reduction in biofilm biomass in all cases. Moreover, most of the biofilm cells remaining on the surface were killed by antibiotics. The addition of 310 nM CDA significantly prevented biofilm formation by the tested micro-organisms, even within mixed cultures, indicating the ability of CDA to inhibit biofilm formation by other types of bacteria in addition to Pseudomonas aeruginosa. These findings suggested that the biofilm-preventive characteristics of CDA make it a noble candidate for inhibition of biofilm-associated infections such as CAUTIs, which paves the way toward developing new strategies to control biofilms in clinical as well as industrial settings. © 2014 The Authors.

The anticancer effect of saffron in two p53 isogenic colorectal cancer cell lines

PubMed Central

2012-01-01

Background Saffron extract, a natural product, has been shown to induce apoptosis in several tumor cell lines. Nevertheless, the p53-dependency of saffron’s mechanism of action in colon cancer remains unexplored. Material and methods In order to examine saffron’s anti-proliferative and pro-apoptotic effects in colorectal cancer cells, we treated two p53 isogenic HCT116 cell lines (HCT wildtype and HCT p53−/−) with different doses of the drug and analyzed cell proliferation and apoptosis in a time-dependent manner. MTT viability and crystal violet assays were performed in order to determine the effective dose of saffron on both cell lines. The cell cycle progress was examined by Flow cytometric analysis. Apoptosis was assessed using Annexin-PI-staining and Western Blotting for caspase 3 and PARP cleavage. Autophagy was determined by Western Blotting of the light chain 3 (LC3)-II and Beclin 1 proteins. The protein content of phospho-H2AX (γH2AX), a sensor of DNA double strand breaks, was also analyzed by Western Blotting. Results Saffron extract induced a p53-dependent pattern of cell cycle distribution with a full G2/M stop in HCT116 p53 wildtype cells. However, it induced a remarkable delay in S/G2 phase transit with entry into mitosis in HCT116 p53 −/− cells. The apoptotic Pre-G1 cell fraction as well as Annexin V staining and caspase 3 cleavage showed a more pronounced apoptosis induction in HCT116 p53 wildtype cells. Obviously, the significantly higher DNA-damage, reflected by ɣH2AX protein levels in cells lacking p53, was coped by up-regulation of autophagy. The saffron-induced LC3-II protein level was a remarkable indication of the accumulation of autophagosomes, a response to the cellular stress condition of drug treatment. Conclusions This is the first study showing the effect of saffron in HCT116 colorectal cancer cells with different p53 status. Saffron induced DNA-damage and apoptosis in both cell lines. However, autophagy has delayed the induction of apoptosis in HCT116 p53 −/− cells. Considering the fact that most tumors show a functional p53 inactivation, further research is needed to elucidate the long-term effects of saffron in p53 −/− tumors. PMID:22640402

HISTOLOGICAL STUDIES OF THE EFFECTS OF CHRONIC IMPLANTATION OF CERAMIC-BASED MICROELECTRODE ARRAYS AND MICRODIALYSIS PROBES IN RAT PREFRONTAL CORTEX

PubMed Central

Hascup, Erin R.; Bjerkén, Sara af; Hascup, Kevin N.; Pomerleau, Francois; Huettl, Peter; Strömberg, Ingrid; Gerhardt, Greg A.

2010-01-01

Chronic implantation of neurotransmitter measuring devices is essential for awake, behavioral studies occurring over multiple days. Little is known regarding the effects of long term implantation on surrounding brain parenchyma and the resulting alterations in the functional properties of this tissue. We examined the extent of tissue damage produced by chronic implantation of either ceramic microelectrode arrays (MEAs) or microdialysis probes. Histological studies were carried out on fixed tissues using stains for neurons (cresyl violet), astrocytes (GFAP), microglia (Iba-1), glutamatergic nerve fibers (VGLUT1), and the blood-brain barrier (SMI-71). Nissl staining showed pronounced tissue body loss with microdialysis implants compared to MEAs. The MEAs produced mild gliosis extending 50–100 µm from the tracks, with a significant change in the affected areas starting at 3 days. By contrast, the microdialysis probes produced gliosis extending 200–300 µm from the track, which was significant at 3 and 7 days. Markers for microglia and glutamatergic fibers supported that the MEAs produce minimal damage with significant changes occurring only at 3 and 7 days that return to control levels by one month. SMI-71 staining supported integrity of the blood brain barrier out to 1 week for both the microdialysis probes and the MEAs. This data support that the ceramic MEAs small size and biocompatibility are necessary to accurately measure neurotransmitter levels in the intact brain. The minimal invasiveness of the MEAs reduce tissue loss, allowing for long term (>6 month) electrochemical and electrophysiological monitoring of brain activity. PMID:19577548

Deep and tapered silicon photonic crystals for achieving anti-reflection and enhanced absorption.

PubMed

Hung, Yung-Jr; Lee, San-Liang; Coldren, Larry A

2010-03-29

Tapered silicon photonic crystals (PhCs) with smooth sidewalls are realized using a novel single-step deep reactive ion etching. The PhCs can significantly reduce the surface reflection over the wavelength range between the ultra-violet and near-infrared regions. From the measurements using a spectrophotometer and an angle-variable spectroscopic ellipsometer, the sub-wavelength periodic structure can provide a broad and angular-independent antireflective window in the visible region for the TE-polarized light. The PhCs with tapered rods can further reduce the reflection due to a gradually changed effective index. On the other hand, strong optical resonances for TM-mode can be found in this structure, which is mainly due to the existence of full photonic bandgaps inside the material. Such resonance can enhance the optical absorption inside the silicon PhCs due to its increased optical paths. With the help of both antireflective and absorption-enhanced characteristics in this structure, the PhCs can be used for various applications.

Surface-enhanced Raman spectroscopy using silver-coated porous glass-ceramic substrates.

PubMed

Pan, Z; Zavalin, A; Ueda, A; Guo, M; Groza, M; Burger, A; Mu, R; Morgan, S H

2005-06-01

Surface-enhanced Raman scattering (SERS) has been studied using a silver-coated porous glass-ceramic material as a new type of substrate. The porous glass-ceramic is in the CaO-TiO2-P2O5 system prepared by controlled crystallization and subsequent chemical leaching of the dense glass-ceramic, leaving a solid skeleton with pores ranging in size from 50 nm to submicrometer. Silver was coated on the surface of the porous glass-ceramic by radio frequency (RF) sputtering or e-beam evaporation in vacuum. SERS spectra of excellent quality were obtained from several dyes and carboxylic acid molecules, including rhodamine 6G, crystal violet, isonicotinic acid, and benzoic acid, using this new substrate. This new substrate showed a good compatibility with these molecules. The porous glass ceramic with a nanometer-structured surface accommodated both test molecules and silver film. The absorbed molecules were therefore better interfaced with silver for surface-enhanced Raman scattering.

Photonic Crystal Based Sensor for Organic Solvents and for Solvent-Water Mixtures

PubMed Central

Fenzl, Christoph; Hirsch, Thomas; Wolfbeis, Otto S.

2012-01-01

Monodisperse polystyrene nanoparticles with a diameter of 173 nm were incorporated into a polydimethylsiloxane matrix where they display an iridescent color that can be attributed to the photonic crystal effect. The film is of violet color if placed in plain water, but turns to red in the presence of the non-polar solvent n-hexane. Several solvents were studied in some detail. We show that such films are capable of monitoring the water content of ethanol/water mixtures, where only 1% (v/v) of water leads to a shift of the peak wavelength of reflected light by 5 nm. The method also can be applied to determine, both visually and instrumentally, the fraction of methanol in ethanol/methanol mixtures. Here, a fraction of 1% of methanol (v/v) results in a wavelength shift of 2 nm. The reflected wavelength is not influenced by temperature changes nor impeded by photobleaching. The signal changes are fully reversible and response times are <1 s. PMID:23235441

Crystal-chemistry of alteration products of vitrified wastes: Implications on the retention of polluting elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sterpenich, Jerome

2008-07-01

Alteration products of vitrified wastes coming from the incineration of household refuse (MSW) are described. Two vitrified wastes containing 50% and 70% of fly ash and a synthetic stained-glass with a composition close to that of an ancient glass (medieval stained-glass) were altered under different pH conditions (1, 5.5 corresponding to demineralized water and 10) during 181 days. Under acidic condition, the alteration layer is made of an amorphous hydrated silica gel impoverished in most of the initial elements. A minor phase MPO{sub 4} . nH{sub 2}O, where M represents Fe, Ti, Al, Ca and K cations, also constitutes themore » altered layer of the synthetic stained-glass. Under neutral and basic conditions, the altered layer is made of an amorphous hydrated silica gel and a crystallized calcium phosphate phase. The silica gel is depleted in alkalis and alkali-earth elements but contains significant amounts of aluminium, magnesium and transition elements, whereas the calcium phosphate is a hydroxylapatite-like phase with P-Si substitutions and a Ca/P ratio depending on the pH of the solution. This study shows: (i) the strong influence of pH conditions on the crystal-chemistry of alteration products and thus on the mechanisms of weathering resulting in different trapping of polluting elements, and (ii) that glass alteration does not necessary produce thermodynamically stable phases which has to be taken into account for the prediction of the long-term behavior.« less

Rational Design of Charge-Transfer Interactions in Halogen-Bonded Co-crystals toward Versatile Solid-State Optoelectronics.

PubMed

Zhu, Weigang; Zheng, Renhui; Zhen, Yonggang; Yu, Zhenyi; Dong, Huanli; Fu, Hongbing; Shi, Qiang; Hu, Wenping

2015-09-02

Charge-transfer (CT) interactions between donor (D) and acceptor (A) groups, as well as CT exciton dynamics, play important roles in optoelectronic devices, such as organic solar cells, photodetectors, and light-emitting sources, which are not yet well understood. In this contribution, the self-assembly behavior, molecular stacking structure, CT interactions, density functional theory (DFT) calculations, and corresponding physicochemical properties of two similar halogen-bonded co-crystals are comprehensively investigated and compared, to construct an "assembly-structure-CT-property" relationship. Bpe-IFB wire-like crystals (where Bpe = 1,2-bis(4-pyridyl)ethylene and IFB = 1,3,5-trifluoro-2,4,6-triiodobenzene), packed in a segregated stacking form with CT ground and excited states, are measured to be quasi-one-dimensional (1D) semiconductors and show strong violet-blue photoluminescence (PL) from the lowest CT1 excitons (ΦPL = 26.1%), which can be confined and propagate oppositely along the 1D axial direction. In comparison, Bpe-F4DIB block-like crystals (F4DIB = 1,4-diiodotetrafluorobenzene), packed in a mixed stacking form without CT interactions, are determined to be insulators and exhibit unique white light emission and two-dimensional optical waveguide property. Surprisingly, it seems that the intrinsic spectroscopic states of Bpe and F4DIB do not change after co-crystallization, which is also confirmed by theoretical calculations, thus offering a new design principle for white light emitting materials. More importantly, we show that the CT interactions in co-crystals are related to their molecular packing and can be triggered or suppressed by crystal engineering, which eventually leads to distinct optoelectronic properties. These results help us to rationally control the CT interactions in organic D-A systems by tuning the molecular stacking, toward the development of a fantastic "optoelectronic world".

21 CFR 73.2775 - Manganese violet.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive... less than 93 percent. (c) Uses and restrictions. Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good manufacturing...

21 CFR 73.2775 - Manganese violet.

Code of Federal Regulations, 2010 CFR

2010-04-01

... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive... less than 93 percent. (c) Uses and restrictions. Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good manufacturing...

21 CFR 73.2775 - Manganese violet.

Code of Federal Regulations, 2013 CFR

2013-04-01

... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive... less than 93 percent. (c) Uses and restrictions. Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good manufacturing...

21 CFR 73.2775 - Manganese violet.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Manganese violet. 73.2775 Section 73.2775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive...

21 CFR 73.3107 - Carbazole violet.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Carbazole violet. 73.3107 Section 73.3107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3107 Carbazole violet. (a) Identity. The color...

21 CFR 73.3107 - Carbazole violet.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Carbazole violet. 73.3107 Section 73.3107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3107 Carbazole violet. (a) Identity. The color...

21 CFR 73.3107 - Carbazole violet.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Carbazole violet. 73.3107 Section 73.3107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3107 Carbazole violet. (a) Identity. The color...

21 CFR 73.3107 - Carbazole violet.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Carbazole violet. 73.3107 Section 73.3107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3107 Carbazole violet. (a) Identity. The color...

21 CFR 73.3107 - Carbazole violet.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Carbazole violet. 73.3107 Section 73.3107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3107 Carbazole violet. (a) Identity. The color...

75 FR 25209 - Carbazole Violet Pigment 23 from India: Rescission of Administrative Review

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-07

... from India: Rescission of Administrative Review AGENCY: Import Administration, International Trade... administrative review of the antidumping duty order on carbazole violet pigment 23 (CVP 23) from India for the...-circumstances review. See Carbazole Violet Pigment 23 from India: Initiation of Antidumping Duty Changed...

75 FR 52930 - Carbazole Violet Pigment 23 From India: Preliminary Results of Antidumping Duty Changed...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-30

... From India: Preliminary Results of Antidumping Duty Changed-Circumstances Review AGENCY: Import... order on carbazole violet pigment 23 from India to determine whether Meghmani Pigments (Meghmani) is the... initiation of an antidumping duty changed- circumstances review. See Carbazole Violet Pigment 23 from India...

75 FR 62765 - Carbazole Violet Pigment 23 From India: Final Results of Antidumping Duty Changed-Circumstances...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-13

... From India: Final Results of Antidumping Duty Changed-Circumstances Review AGENCY: Import...-in-interest to Alpanil Industries. See Carbazole Violet Pigment 23 From India: Preliminary Results of... Carbazole Violet Pigment 23 From India: Final Results of Antidumping Duty Administrative Review, 75 FR 38076...

21 CFR 589.1000 - Gentian violet.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentian violet. 589.1000 Section 589.1000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Substances Prohibited From Use in Animal Food or Feed § 589.1000 Gentian violet. The Food and Drug...

Effects of anthocyanin and carotenoid combinations on foliage and immature fruit color of Capsicum annuum L.

PubMed

Lightbourn, Gordon J; Griesbach, Robert J; Novotny, Janet A; Clevidence, Beverly A; Rao, David D; Stommel, John R

2008-01-01

Shades ranging from violet to black pigmentation in pepper (Capsicum annuum L.) are attributed to anthocyanin accumulation. High-performance liquid chromatography and mass spectrometry analysis of violet and black fruit tissue identified a single anthocyanin that was determined to be delphinidin-3-p-coumaroyl-rutinoside-5-glucoside. Leaf tissue of a black-pigmented foliage genotype contained the same anthocyanin found in fruit but at a considerably higher concentration in comparison to violet and black fruit tissue. Fruit chlorophyll concentration was approximately 14-fold higher in black fruit in comparison to violet fruit that contained relatively little chlorophyll. Beta-carotene, lutein, violaxanthin, and neoxanthin carotenoid concentrations in black fruit were also significantly greater in comparison to violet fruit. High concentrations of delphinidin in combination with chlorophyll and accessory carotenoid pigments produced the characteristic black pigmentation observed in fruits and leaves of selected genotypes. Anthocyanins were accumulated in the outer mesocarp of violet and black fruit and in the palisade and mesophyll cells of black leaves. Consistent with chlorophyll content of respective genotypes, chloroplast density was greater in cells of black fruits. Utilizing Capsicum pigment variants, we determine the biochemical factors responsible for violet versus black-pigmented pepper tissue in the context of described pepper color genes.

New developments in fluorescence detection of ALA-induced protoporphyrin IX for cancer localization

NASA Astrophysics Data System (ADS)

Stepp, Herbert G.; Baumgartner, Reinhold; Betz, Christian; Bise, Karl; Brand, P.; Gamarra, Fernando; Haeussinger, Karl; Hillemanns, Peter; Huber, Rudolf M.; Knuechel, Ruth; Kriegmair, M.; Leunig, Andreas; Pichler, J.; Rick, Kai; Schulz, H.; Stanzel, F.; Stocker, Susanne; Wagner, Simon; Weigandt, H.

1997-12-01

After the very promising clinical results for the detection of bladder cancer in urology, preclinical and clinical studies on aminolevulinic acid (5-ALA) induced protoporphyrin IX (PPIX) are preformed in various disciplines now. This paper provides a brief overview of the progress on 5-ALA assisted fluorescence diagnosis in urology, pulmonology, neurosurgery, gynecology and ENT performed in collaboration with the Laser Research Laboratory at the Department of Urology of the Ludwig-Maximilians-University in Munich. Five-ALA can be applied either topically or systemically to induce an intracellular accumulation of fluorescing PPIX. With appropriate dosage of 5-ALA, malignant tissue can be stained selectively, and irradiation with violet light excites a bright red fluorescence of the tumor. Optical properties of the tissue tend to hamper the precise identification and demarcation of suspect areas in fluorescence images. Multicolor remission and fluorescence imaging, therefore, seems to be indispensable for a reliable tumor localization.

Latest results of 5-ALA-based fluorescence diagnosis and other medical disciplines

NASA Astrophysics Data System (ADS)

Baumgartner, Reinhold

1999-02-01

Preclinical and clinical studies on 5-aminolevulinic acid (5- ALA) induced Protoporphyrin IX (PPIX) are performed in various departments now following promising clinical results for the detection of bladder cancer in urology. This paper provides an overview on the progress of 5-ALA assisted fluorescence diagnosis in urology, pulmonology, neurosurgery, gynecology and ENT coordinated by the Laser Research Laboratory of the Ludwig-Maximilians-University in Munich. 5-ALA can be applied either topically or systematically to induce an intracellular accumulation of fluorescing PPIX. With appropriate dosage of 5-ALA, malignant tissue can be stained selectively, and irradiation with violet light excites a bright red fluorescence of the tumor visible with naked eyes. Optical properties of the tissue tend to hamper the precise identification and demarcation of suspect areas in fluorescence images. Multicolor remission and fluorescence imaging, therefore, should improve tumor localization in future.

7 CFR 93.11 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... fluoresce when viewed under UV light as follows: aflatoxin B1 and derivatives with a blue fluorescence, aflatoxin B2 with a blue-violet fluorescence, aflatoxin G1 with a green fluorescence, aflatoxin G2 with a green-blue fluorescence, aflatoxin M1 with a blue-violet fluorescence, and aflatoxin M2 with a violet...

7 CFR 93.11 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... fluoresce when viewed under UV light as follows: aflatoxin B1 and derivatives with a blue fluorescence, aflatoxin B2 with a blue-violet fluorescence, aflatoxin G1 with a green fluorescence, aflatoxin G2 with a green-blue fluorescence, aflatoxin M1 with a blue-violet fluorescence, and aflatoxin M2 with a violet...

7 CFR 93.11 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... fluoresce when viewed under UV light as follows: aflatoxin B1 and derivatives with a blue fluorescence, aflatoxin B2 with a blue-violet fluorescence, aflatoxin G1 with a green fluorescence, aflatoxin G2 with a green-blue fluorescence, aflatoxin M1 with a blue-violet fluorescence, and aflatoxin M2 with a violet...

7 CFR 93.11 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... fluoresce when viewed under UV light as follows: aflatoxin B1 and derivatives with a blue fluorescence, aflatoxin B2 with a blue-violet fluorescence, aflatoxin G1 with a green fluorescence, aflatoxin G2 with a green-blue fluorescence, aflatoxin M1 with a blue-violet fluorescence, and aflatoxin M2 with a violet...

7 CFR 93.11 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... fluoresce when viewed under UV light as follows: aflatoxin B1 and derivatives with a blue fluorescence, aflatoxin B2 with a blue-violet fluorescence, aflatoxin G1 with a green fluorescence, aflatoxin G2 with a green-blue fluorescence, aflatoxin M1 with a blue-violet fluorescence, and aflatoxin M2 with a violet...

75 FR 13257 - Carbazole Violet Pigment 23 from India: Final Results of the Expedited Five-year (Sunset) Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-19

...) and finished pigment in the form of presscake and dry color. Pigment dispersions in any form (e.g... DEPARTMENT OF COMMERCE International Trade Administration [C-533-839] Carbazole Violet Pigment 23... countervailing duty (CVD) order on Carbazole Violet Pigment 23 (CVP-23) [[Page 13258

75 FR 10759 - Carbazole Violet Pigment 23 from India: Initiation of Antidumping Duty Changed-Circumstances Review

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-09

... dispersions in any form (e.g., pigment dispersed in oleoresins, flammable solvents, water) are not included... DEPARTMENT OF COMMERCE International Trade Administration [A-533-838] Carbazole Violet Pigment 23... changed-circumstances review of the antidumping duty order on carbazole violet pigment 23 from India with...

Crystalline folliculitis revealed by non-aqueous staining technique.

PubMed

Siscos, Spyros Michael; Tran, Chi; Fischer, Ryan; Fraga, Garth

2017-07-15

Necrotizing infundibular crystalline folliculitis (NICF) is a rare superficial folliculitis characterized by expansive deposits of birefringent crystallized lipid. We report a case of NICF in a transplant patient presenting with folliculocentric acneiform papules across the lateral face and neck. Biopsy demonstrated intrafollicular crystalline deposits within an intact epidermis. Diagnostic crystals were identified using a non-aqueous histologic technique involving thick unstained sections. To our knowledge, this is the first report of NICF in a transplant patient. Our case suggests NICF is a follicular disorder and highlights a technique that may prevent loss of birefringent crystals and assist in facilitating accurate diagnosis.

Migration behavior of organic dyes based on physicochemical properties of solvents as background electrolytes in non-aqueous capillary electrophoresis.

PubMed

Gu, Minjeong; Cho, Keunchang; Kang, Seong Ho

2018-07-27

The migration behavior of organic fluorescent dyes (i.e., crystal violet, methyl violet base, methyl violet B base, rhodamine 6G, and rhodamine B base) in non-aqueous capillary electrophoresis (NACE) was investigated by focusing on the physicochemical properties of various organic solvents [ethanol, methanol, 2-propanol, dimethylformamide (DMF), and dimethyl sulfoxide (DMSO)] in background electrolyte (BGE). Laser-induced fluorescence (LIF) and UV/Vis detectors were employed to observe both the migration time of organic dyes and the electroosmotic flow (EOF) in NACE, respectively. As seen in conventional aqueous BGE, the mobility of EOF in organic solvents tended to rise when the ratio between the dielectric constant and the solvent's viscosity (ε/η) increased in accordance with Smoluchowski's equation. However, unlike the ε/η of pure organic solvents, the migration order of dyes changed as follows: methanol (60.0) > DMF (45.8) > ethanol (22.8) > DMSO (23.4) > 2-propanol (9.8). Since the amount of acetic acid added to balance the pH depends on the pK a of each solvent, EOF changed when the difference in the ε/η value was small. This resulted from the inhibition of mobility, and its difference was dependent on the ε/η of BGEs with high ionic strength. In particular, the actual mobility of dyes in DMF showed excellent compliance with the Debye-Hückel-Onsager (DHO) theory extended by Falkenhagen and Pitts, which enabled us to analyze all dyes within 15 min with excellent resolution (R s >  2.5) under optimum NACE conditions (10 mM sodium borate and 4661 mM acetic acid in 100% DMF, pH 4.5). In addition, the NACE method was successfully applied for analyzing commercially available ballpoint ink pens. Thus, these results could be used to anticipate the migration order of organic dyes in a 100% NACE separation system. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of single- and multi-strain probiotics on biofilm formation and in vitro adhesion to bladder cells by urinary tract pathogens.

PubMed

Chapman, C M C; Gibson, G R; Rowland, I

2014-06-01

There is increasing evidence that probiotic bacteria can inhibit and/or prevent urinary tract infections. Possible mechanisms include prevention of adhesion of pathogens to the bladder epithelium and inhibition of biofilm formation. Currently there is interest in the comparative efficacy of single probiotics vs. strain mixtures. We have therefore tested the inhibitory activity of four single probiotics and four probiotic mixtures towards the urinary tract pathogens Escherichia coli NCTC 9001 and Enterococcus faecalis NCTC 00775. Inhibition of biofilm formation by cell-free supernatants was tested using the Crystal Violet assay, while prevention of pathogen adhesion to host cells was tested by using bladder cancer cells as a model for the human urinary tract. Under pH-controlled conditions, there was no significant inhibition of biofilm formation by any treatment. Without pH control, 5/8 treatments significantly inhibited biofilm production by E. coli, while 5/8 treatments inhibited production by E. faecalis. Using data from all Crystal Violet assays, there was no significant difference in the ability of single- and multi-strain probiotics to inhibit biofilm formation. In the cell culture assays, all treatments were able to significantly reduce numbers of pathogenic cells adhering to host cells by 2.5-3.5 logs. No significant difference was observed between the displacement caused by single strains and mixtures for either pathogen. Inhibition of biofilm seems to be a major mechanism of urinary tract pathogen exclusion, related to, and possibly dependent upon, the probiotic ability to reduce environmental pH. Exclusion via competition of binding sites is a possible in vivo mechanism for these probiotics. If an additive or synergistic effect exists between strains within a mixture, it does not manifest itself in a greater effect through these two inhibitory mechanisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

ITE inhibits growth of human pulmonary artery endothelial cells.

PubMed

Pang, Ling-Pin; Li, Yan; Zou, Qing-Yun; Zhou, Chi; Lei, Wei; Zheng, Jing; Huang, Shi-An

2017-10-01

Pulmonary arterial hypertension (PAH), a deadly disorder is associated with excessive growth of human pulmonary artery endothelial (HPAECs) and smooth muscle (HPASMCs) cells. Current therapies primarily aim at promoting vasodilation, which only ameliorates clinical symptoms without a cure. 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) is an endogenous aryl hydrocarbon receptor (AhR) ligand, and mediates many cellular function including cell growth. However, the roles of ITE in human lung endothelial cells remain elusive. Herein, we tested a hypothesis that ITE inhibits growth of human pulmonary artery endothelial cells via AhR. Immunohistochemistry was performed to localize AhR expression in human lung tissues. The crystal violet method and MTT assay were used to determine ITE's effects on growth of HPAECs. The AhR activation in HPAECs was confirmed using Western blotting and RT-qPCR. The role of AhR in ITE-affected proliferation of HPAECs was assessed using siRNA knockdown method followed by the crystal violet method. Immunohistochemistry revealed that AhR was present in human lung tissues, primarily in endothelial and smooth muscle cells of pulmonary veins and arteries, as well as in bronchial and alveolar sac epithelia. We also found that ITE dose- and time-dependently inhibited proliferation of HPAECs with a maximum inhibition of 83% at 20 µM after 6 days of treatment. ITE rapidly decreased AhR protein levels, while it increased mRNA levels of cytochrome P450 (CYP), family 1, member A1 (CYP1A1) and B1 (CYP1B1), indicating activation of the AhR/CYP1A1 and AhR/CYP1B1 pathways in HPAECs. The AhR siRNA significantly suppressed AhR protein expression, whereas it did not significantly alter ITE-inhibited growth of HPAECs. ITE suppresses growth of HPAECs independent of AhR, suggesting that ITE may play an important role in preventing excessive growth of lung endothelial cells.

77 FR 1463 - Carbazole Violet Pigment 23 From the People's Republic of China: Final Rescission of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-10

... finished pigment in the form of presscake and dry color. Pigment dispersions in any form (e.g., pigments... DEPARTMENT OF COMMERCE International Trade Administration [A-570-892] Carbazole Violet Pigment 23... administrative review of the antidumping duty order on carbazole violet pigment 23 (CVP-23) from the People's...

76 FR 55003 - Carbazole Violet Pigment 23 From the People's Republic of China: Preliminary Intent To Rescind...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-06

... finished pigment in the form of presscake and dry color. Pigment dispersions in any form (e.g., pigments... DEPARTMENT OF COMMERCE International Trade Administration [A-570-892] Carbazole Violet Pigment 23... antidumping duty order on carbazole violet pigment 23 (CVP 23) from the People's Republic of China (PRC). This...

Amelogenins as Potential Buffers during Secretory-stage Amelogenesis

PubMed Central

Guo, J.; Lyaruu, D.M.; Takano, Y.; Gibson, C.W.; DenBesten, P.K.

2015-01-01

Amelogenins are the most abundant protein species in forming dental enamel, taken to regulate crystal shape and crystal growth. Unprotonated amelogenins can bind protons, suggesting that amelogenins could regulate the pH in enamel in situ. We hypothesized that without amelogenins the enamel would acidify unless ameloblasts were buffered by alternative ways. To investigate this, we measured the mineral and chloride content in incisor enamel of amelogenin-knockout (AmelX-/-) mice and determined the pH of enamel by staining with methyl-red. Ameloblasts were immunostained for anion exchanger-2 (Ae2), a transmembrane pH regulator sensitive for acid that secretes bicarbonate in exchange for chloride. The enamel of AmelX-/- mice was 10-fold thinner, mineralized in the secretory stage 1.8-fold more than wild-type enamel and containing less chloride (suggesting more bicarbonate secretion). Enamel of AmelX-/- mice stained with methyl-red contained no acidic bands in the maturation stage as seen in wild-type enamel. Secretory ameloblasts of AmelX-/- mice, but not wild-type mice, were immunopositive for Ae2, and stained more intensely in the maturation stage compared with wild-type mice. Exposure of AmelX-/- mice to fluoride enhanced the mineral content in the secretory stage, lowered chloride, and intensified Ae2 immunostaining in the enamel organ in comparison with non-fluorotic mutant teeth. The results suggest that unprotonated amelogenins may regulate the pH of forming enamel in situ. Without amelogenins, Ae2 could compensate for the pH drop associated with crystal formation. PMID:25535204

Amelogenins as potential buffers during secretory-stage amelogenesis.

PubMed

Guo, J; Lyaruu, D M; Takano, Y; Gibson, C W; DenBesten, P K; Bronckers, A L J J

2015-03-01

Amelogenins are the most abundant protein species in forming dental enamel, taken to regulate crystal shape and crystal growth. Unprotonated amelogenins can bind protons, suggesting that amelogenins could regulate the pH in enamel in situ. We hypothesized that without amelogenins the enamel would acidify unless ameloblasts were buffered by alternative ways. To investigate this, we measured the mineral and chloride content in incisor enamel of amelogenin-knockout (AmelX(-/-)) mice and determined the pH of enamel by staining with methyl-red. Ameloblasts were immunostained for anion exchanger-2 (Ae2), a transmembrane pH regulator sensitive for acid that secretes bicarbonate in exchange for chloride. The enamel of AmelX(-/-) mice was 10-fold thinner, mineralized in the secretory stage 1.8-fold more than wild-type enamel and containing less chloride (suggesting more bicarbonate secretion). Enamel of AmelX(-/-) mice stained with methyl-red contained no acidic bands in the maturation stage as seen in wild-type enamel. Secretory ameloblasts of AmelX(-/-) mice, but not wild-type mice, were immunopositive for Ae2, and stained more intensely in the maturation stage compared with wild-type mice. Exposure of AmelX(-/-) mice to fluoride enhanced the mineral content in the secretory stage, lowered chloride, and intensified Ae2 immunostaining in the enamel organ in comparison with non-fluorotic mutant teeth. The results suggest that unprotonated amelogenins may regulate the pH of forming enamel in situ. Without amelogenins, Ae2 could compensate for the pH drop associated with crystal formation. © International & American Associations for Dental Research 2014.

Ablation of dentin by irradiation of violet diode laser

NASA Astrophysics Data System (ADS)

Hatayama, H.; Kato, J.; Akashi, G.; Hirai, Y.; Inoue, A.

2006-02-01

Several lasers have been used for clinical treatment in dentistry. Among them, diode lasers are attractive because of their compactness compared with other laser sources. Near-infrared diode lasers have been practically used for cutting soft tissues. Because they penetrate deep to soft tissues, they cause sufficiently thick coagulation layer. However, they aren't suitable for removal of carious dentin because absorption by components in dentin is low. Recently, a violet diode laser with a wavelength of 405nm has been developed. It will be effective for cavity preparation because dentin contains about 20% of collagen whose absorption coefficient at a violet wavelength is larger than that at a near-infrared wavelength. In this paper, we examined cutting performance of the violet diode laser for dentin. To our knowledge, there have been no previous reports on application of a violet laser to dentin ablation. Bovine teeth were irradiated by continuous wave violet diode laser with output powers in a range from 0.4W to 2.4W. The beam diameter on the sample was about 270μm and an irradiation time was one second. We obtained the crater ablated at more than an output power of 0.8W. The depth of crater ranged from 20μm at 0.8W to 90μm at 2.4W. Furthermore, the beam spot with an output power of 1.7W was scanned at a speed of 1mm/second corresponding to movement of a dentist's hand in clinical treatment. Grooves with the depth of more than 50μm were also obtained. From these findings, the violet diode laser has good potential for cavity preparation. Therefore, the violet diode laser may become an effective tool for cavity preparation.

RADIATION-CAUSED CYTOCHEMICAL CHANGES IN NEURONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kagan, E.H.; Brownson, R.H.; Suter, D.B.

1962-09-01

The acute effects of ionizing radiation on the brain of rats were evaluated by using the acid phosphatase method of Gomori. Head irradiation was carried out with 1000-kv x rays at dose rates of 250 to 600 r/min and doses of 1500 to 10,000 r. The brains were examined 3 hr to 4 months later. The observed acute behavioral changes of apathy and sluggishness correlated with alterations in acidphosphatase-containing particles, which showed increased size and conglomeration in cortical neurons and especially Purkinje cells of the cerebellum. This early cytochemical effect of radiation was not noted with cresyl fast violet ormore » periodic acid-Schiff-stained material. The alterations were limited to ganglion cells; no glial or vascular lesions were noted by any staining procedure. In the Purkinje cells at higher dose ranges, up to one-half of the cells showed alterations in the form of swelling and conglomeration of the acid phosphatase particles, as well as diffuse cytoplasrnic staining. These alterations in acid-phosphatasecontaining particles were similar to changes in rat brains subjected to anoxic and anoxic-ischemic conditions, autolysis, and injection of diphtheria toxin. There was also a striking similarity between these changes and alterations in kidney and liver lysosomes as a result of experimental hydronephrosis. Animals killed four months after irradiation demonstrated the reversible nature of the lesion, which is correlated with reports of an initial reversible behavioral syndrome. The described cytochemical lesion is interpreted as morphological evidence of cell damage or altered cellular metabolism and not as a specific lesion caused by x irradiation. The apparent reversibility of the lesion and the fact that several different mechanisms have all demonstrated similar effects on acid-phosphatasecontaining particles in brain, kidney, and liver further point toward its nonspecific nature. (H.H.D.)« less

An LED Approach for Measuring the Photocatalytic Breakdown of Crystal Violet Dye

NASA Technical Reports Server (NTRS)

Ryan, Robert E.; Underwood, Lauren W.; ONeal, Duane; Pagnutti, Mary; Davis, Bruce A.

2009-01-01

A simple technique to assess the reactivity of photocatalytic coatings sprayed onto transmissive glass surfaces was developed. This new method uses ultraviolet (UV) gallium nitride (GaN) light-emitting diodes (LEDs) to drive a photocatalytic reaction (the photocatalytic breakdown of a UV-resistant dye applied to a surface coated with the semiconductor titanium dioxide); and then a combination of a stabilized white light LED and a spectrometer to track the dye degradation as a function of time. Simple, standardized evaluation techniques that assess photocatalytic materials over a variety of environmental conditions, including illumination level, are not generally available and are greatly needed prior to in situ application of photocatalytic technologies. To date, much research pertaining to this aspect of photocatalysis has been limited and has focused primarily on laboratory experiments using mercury lamps. Mercury lamp illumination levels are difficult to control over large ranges and are temporally modulated by line power, limiting their use in helping to understand and predict how photocatalytic materials will behave in natural environmental settings and conditions. The methodology described here, using steady-state LEDs and time series spectroradiometric techniques, is a novel approach to explore the effect of UV light on the photocatalytic degradation of a UV resistant dye (crystal violet). GaN UV LED arrays, centered around 365 nm with an adjustable DC power supply, are used to create a small, spatially uniform light field where the steady state light level can be varied over three to four orders of magnitude. For this study, a set of glass microscope slides was custom coated with a thinly sprayed layer of photocatalytic titanium dioxide. Crystal violet was then applied to these titanium-dioxide coated slides and to uncoated control slides. The slides were then illuminated at various light levels from the dye side of the slide by the UV LED array. To monitor dye degradation on the slides over time, a temperature-stabilized white light LED was used to illuminate the opposite side of the slides. As the dye degraded, the amount of light from the white light LED transmitted through the slide was monitored with a spectrometer and subsequently analyzed to determine and compare the rate of dye degradation for photocatalytically coated versus uncoated slide surfaces. The long-term stability of the spectrometer/white light LED combination, which required only a single reference spectra to be taken for a time series sequence of several hours, enabled accurate measurements of transmitted light over time. Time series transmission curves were generated and results demonstrated that over time the transmission increased much more rapidly on the coated slides than on the control slides. This experimental configuration and methodology for photocatalytic activity measurement minimizes many external variable effects and allows low light level studies to be performed. This study also compares the advantages of this novel LED light source design to traditional mercury lamp systems and non-LED lamp approaches that have conventionally been used. The methodology and experimental design research summarized in this abstract is partly funded by the Department of Homeland Security, Science and Technology Directorate, and by the NASA Stennis Space Center Innovative Partnerships Program.

21 CFR 74.1602 - D&C Violet No. 2.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false D&C Violet No. 2. 74.1602 Section 74.1602 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Drugs § 74.1602 D&C Violet No. 2. (a) Identity. (1) The color additive D...

21 CFR 74.3602 - D&C Violet No. 2.

Code of Federal Regulations, 2013 CFR

2013-04-01

... coloring absorbable meniscal tacks made from poly (L-lactic acid) at a level not to exceed 0.15 percent by... 21 Food and Drugs 1 2013-04-01 2013-04-01 false D&C Violet No. 2. 74.3602 Section 74.3602 Food and... ADDITIVES SUBJECT TO CERTIFICATION Medical Devices § 74.3602 D&C Violet No. 2. (a) Identity and...

21 CFR 74.3602 - D&C Violet No. 2.

Code of Federal Regulations, 2011 CFR

2011-04-01

... coloring absorbable meniscal tacks made from poly (L-lactic acid) at a level not to exceed 0.15 percent by... 21 Food and Drugs 1 2011-04-01 2011-04-01 false D&C Violet No. 2. 74.3602 Section 74.3602 Food and... ADDITIVES SUBJECT TO CERTIFICATION Medical Devices § 74.3602 D&C Violet No. 2. (a) Identity and...

21 CFR 74.3602 - D&C Violet No. 2.

Code of Federal Regulations, 2012 CFR

2012-04-01

... coloring absorbable meniscal tacks made from poly (L-lactic acid) at a level not to exceed 0.15 percent by... 21 Food and Drugs 1 2012-04-01 2012-04-01 false D&C Violet No. 2. 74.3602 Section 74.3602 Food and... ADDITIVES SUBJECT TO CERTIFICATION Medical Devices § 74.3602 D&C Violet No. 2. (a) Identity and...

21 CFR 74.3602 - D&C Violet No. 2.

Code of Federal Regulations, 2014 CFR

2014-04-01

... coloring absorbable meniscal tacks made from poly (L-lactic acid) at a level not to exceed 0.15 percent by... 21 Food and Drugs 1 2014-04-01 2014-04-01 false D&C Violet No. 2. 74.3602 Section 74.3602 Food and... ADDITIVES SUBJECT TO CERTIFICATION Medical Devices § 74.3602 D&C Violet No. 2. (a) Identity and...

21 CFR 74.3602 - D&C Violet No. 2.

Code of Federal Regulations, 2010 CFR

2010-04-01

... coloring absorbable meniscal tacks made from poly (L-lactic acid) at a level not to exceed 0.15 percent by... 21 Food and Drugs 1 2010-04-01 2010-04-01 false D&C Violet No. 2. 74.3602 Section 74.3602 Food and... ADDITIVES SUBJECT TO CERTIFICATION Medical Devices § 74.3602 D&C Violet No. 2. (a) Identity and...

21 CFR 82.1602 - D&C Violet No. 2.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false D&C Violet No. 2. 82.1602 Section 82.1602 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF CERTIFIED... additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of § 74.1602(a...

Ferroindialite (Fe2+,Mg)2Al4Si5O18, a new beryl-group mineral from the Eifel volcanic region, Germany

NASA Astrophysics Data System (ADS)

Chukanov, N. V.; Aksenov, S. M.; Pekov, I. V.; Ternes, B.; Schüller, W.; Belakovskiy, D. I.; Van, K. V.; Blass, G.

2014-12-01

A new mineral, ferroindialite, a Fe2+-dominant analog of indialite, has been found in a pyrometamorphosed xenolith of pelitic rock hosted in alkaline basalts. Associated minerals are phlogopite, sanidine, sillimanite, pyroxenes of the enstatite-ferrosilite series, wagnerite, fluorapatite, tridymite, zircon and almandine. Ferroindialite forms brown-purple to gray with a violet-blue tint short prismatic or thick tabular hexagonal crystals up to 1.5 mm in size. The new mineral is brittle, with a Mohs' hardness of 7. Cleavage is not observed. D meas = 2.66(1), D calc = 2.667 g/cm3. IR spectrum shows neither H2O nor OH groups. Ferroindialite is anomalously biaxial (-), α = 1.539(2), β = 1.552(2), γ = 1.554(2), 2 V meas = 30(10)°. The mineral is weakly pleochroic, ranging from colorless on X to pale violet on Z. Dispersion is weak, r < v. The chemical composition (electron microprobe, mean of five point analyses, wt %) is as follows: 0.14 Na2O, 0.46 K2O, 4.95 MgO, 1.13 MnO, 12.66 FeO, 2.64 Fe2O3, 30.45 Al2O3, 47.22 SiO2, total is 99.65. The distribution of total iron content between Fe2+ and Fe3+ was carried out according to structural data. The empirical formula of ferroindialite is: (K0.06Na0.03)(Fe{1.12/2+}Mg0.78Mn0.10)Σ2.00(Al3.79Fe{0.21/3+})Σ4.00Si4.98O18. The simplified formula is: (Fe2+,Mg)2Al4Si5O18. The crystal structure has been refined on a single crystal, R = 0.049. Ferroindialite is hexagonal, space group P6/ mcc; a = 9.8759(3), c = 9.3102(3) Å, V = 786.40(3) Å3, Z = 2. The strongest lines in the X-ray powder diffraction pattern [ d, Å ( I, %) ( hkl)] are: 8.59 (100) (100), 4.094 (27) (102), 3.390 (35) (112), 3.147 (19) (202), 3.055 (31) (211), 2.657 (12) (212), 1.695 (9) (224). The type specimen of ferroindialite is deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, registration number 4400/1.

Growth, spectroscopic and physicochemical properties of bis mercury ferric chloride tetra thiocyanate: A nonlinear optical crystal

NASA Astrophysics Data System (ADS)

Ramesh, V.; Shihabuddeen Syed, A.; Jagannathan, K.; Rajarajan, K.

2013-05-01

Single crystal of bis mercury ferric chloride tetra thiocyanate [Hg2FeCl3(SCN)4; (MFCTC)] was grown from ethanol-water (3:1) mixed solvent using slow evaporation solvent technique (SEST) for the first time. The cell parameters of the grown crystal were confirmed by single crystal XRD. The coordination of transition metal ions with the SCN ligand is well-identified using FT-IR spectral analysis. The chemical composition of MFCTC was confirmed using CHNS elemental test. The ESR spectral profile of MFCTC was recorded from 298 K to 110 K, which strongly suggests the incorporation of Fe3+ ion and its environment with respect to SCN ligand. The HPLC chromatogram of MFCTC highlights the purity of the compound. The UV-Vis-NIR studies revealed the ultra violet cut-off wavelength of MFCTC in ethanol as 338 nm. The dielectric constant and dielectric loss of the sample were studied as a function of frequency and temperature. The TGA-DTA and DSC thermal analysis show that the sample is thermally stable up to 234.31 °C, which is comparatively far better than the thermal stability of Hg3CdCl2(SCN)6; (171.3 °C) and other metal-organic coordination complex crystals such as CdHg(SCN)4 (198.5 °C), Hg(N2H4CS)4Mn(SCN)4 (199.06 °C) and Hg(N2H4CS)4Zn(SCN)4 (185 °C). The SHG conversion efficiency of MFCTC is found to be higher than KDP.

Magnetic solid-phase extraction for determination of the total malachite green, gentian violet and leucomalachite green, leucogentian violet in aquaculture water by high-performance liquid chromatography with fluorescence detection.

PubMed

Zhao, Jiao; Wei, Daqiao; Yang, Yaling

2016-06-01

In this study, magnetic multi-walled carbon nanotube nanoparticles were synthesized and used as the adsorbent for the sums of malachite green, gentian violet and leucomalachite green, leucogentian violet in aquaculture water samples followed by high performance liquid chromatography with fluorescence detection. This method was based on in situ reduction of chromic malachite green, gentian violet to colorless leucomalachite green, leucogentian violet with potassium borohydride, respectively. The obtained adsorbent combines the advantages of carbon nanotubes and Fe3 O4 nanoparticles in one material for separation and preconcentration of the reductive dyes in aqueous media. The structure and properties of the prepared nanoparticles were characterized by transmission and scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The main parameters affecting the adsorption recoveries were investigated and optimized, including reducing agent concentration, type and amount of sorbent, sample pH, and eluting conditions. Under the optimum conditions, the limits of detection in this method were 0.22 and 0.09 ng/mL for malachite green and gentian violet, respectively. Product recoveries ranged from 87.0 to 92.8% with relative standard deviations from 4.6 to 5.9%. The results indicate that the sorbent is a suitable material for the removal and concentration of triphenylmethane dyes from polluted environmental samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication of a Silicon MOSFET Device with Bipolar Transistor Source,

DTIC Science & Technology

1980-07-01

NEGATIVE PHOTORESIST PROCEDURE ’•J n •:• fi >. 3 u i fc- Process Coat wafer Air dry Pre bake the resist coating Expose Develop Method Time...Orange (rather broad for orange) 0.82 Salmon 0.85 Dull, light red-violet 0.86 Violet £ 0.87 Blue-violet 0.89 Blue ::’ 0.92 V Blue-green •I 0.95

Programmable Colored Illumination Microscopy (PCIM): A practical and flexible optical staining approach for microscopic contrast enhancement

NASA Astrophysics Data System (ADS)

Zuo, Chao; Sun, Jiasong; Feng, Shijie; Hu, Yan; Chen, Qian

2016-03-01

Programmable colored illumination microscopy (PCIM) has been proposed as a flexible optical staining technique for microscopic contrast enhancement. In this method, we replace the condenser diaphragm of a conventional microscope with a programmable thin film transistor-liquid crystal display (TFT-LCD). By displaying different patterns on the LCD, numerous established imaging modalities can be realized, such as bright field, dark field, phase contrast, oblique illumination, and Rheinberg illuminations, which conventionally rely on intricate alterations in the respective microscope setups. Furthermore, the ease of modulating both the color and the intensity distribution at the aperture of the condenser opens the possibility to combine multiple microscopic techniques, or even realize completely new methods for optical color contrast staining, such as iridescent dark-field and iridescent phase-contrast imaging. The versatility and effectiveness of PCIM is demonstrated by imaging of several transparent colorless specimens, such as unstained lung cancer cells, diatom, textile fibers, and a cryosection of mouse kidney. Finally, the potentialities of PCIM for RGB-splitting imaging with stained samples are also explored by imaging stained red blood cells and a histological section.

Selective formation of porous silicon

NASA Technical Reports Server (NTRS)

Fathauer, Jones (Inventor)

1993-01-01

A pattern of porous silicon is produced in the surface of a silicon substrate by forming a pattern of crystal defects in said surface, preferably by applying an ion milling beam through openings in a photoresist layer to the surface, and then exposing said surface to a stain etchant, such as HF:HNO3:H20. The defected crystal will preferentially etch to form a pattern of porous silicon. When the amorphous content of the porous silicon exceeds 70 percent, the porous silicon pattern emits visible light at room temperature.

Artificial selection for structural color on butterfly wings and comparison with natural evolution

PubMed Central

Wasik, Bethany R.; Liew, Seng Fatt; Lilien, David A.; Dinwiddie, April J.; Noh, Heeso; Cao, Hui; Monteiro, Antónia

2014-01-01

Brilliant animal colors often are produced from light interacting with intricate nano-morphologies present in biological materials such as butterfly wing scales. Surveys across widely divergent butterfly species have identified multiple mechanisms of structural color production; however, little is known about how these colors evolved. Here, we examine how closely related species and populations of Bicyclus butterflies have evolved violet structural color from brown-pigmented ancestors with UV structural color. We used artificial selection on a laboratory model butterfly, B. anynana, to evolve violet scales from UV brown scales and compared the mechanism of violet color production with that of two other Bicyclus species, Bicyclus sambulos and Bicyclus medontias, which have evolved violet/blue scales independently via natural selection. The UV reflectance peak of B. anynana brown scales shifted to violet over six generations of artificial selection (i.e., in less than 1 y) as the result of an increase in the thickness of the lower lamina in ground scales. Similar scale structures and the same mechanism for producing violet/blue structural colors were found in the other Bicyclus species. This work shows that populations harbor large amounts of standing genetic variation that can lead to rapid evolution of scales’ structural color via slight modifications to the scales’ physical dimensions. PMID:25092295

Artificial selection for structural color on butterfly wings and comparison with natural evolution.

PubMed

Wasik, Bethany R; Liew, Seng Fatt; Lilien, David A; Dinwiddie, April J; Noh, Heeso; Cao, Hui; Monteiro, Antónia

2014-08-19

Brilliant animal colors often are produced from light interacting with intricate nano-morphologies present in biological materials such as butterfly wing scales. Surveys across widely divergent butterfly species have identified multiple mechanisms of structural color production; however, little is known about how these colors evolved. Here, we examine how closely related species and populations of Bicyclus butterflies have evolved violet structural color from brown-pigmented ancestors with UV structural color. We used artificial selection on a laboratory model butterfly, B. anynana, to evolve violet scales from UV brown scales and compared the mechanism of violet color production with that of two other Bicyclus species, Bicyclus sambulos and Bicyclus medontias, which have evolved violet/blue scales independently via natural selection. The UV reflectance peak of B. anynana brown scales shifted to violet over six generations of artificial selection (i.e., in less than 1 y) as the result of an increase in the thickness of the lower lamina in ground scales. Similar scale structures and the same mechanism for producing violet/blue structural colors were found in the other Bicyclus species. This work shows that populations harbor large amounts of standing genetic variation that can lead to rapid evolution of scales' structural color via slight modifications to the scales' physical dimensions.

Sudan stain of fecal fat: new insight into an old test.

PubMed

Khouri, M R; Huang, G; Shiau, Y F

1989-02-01

The 72-h fecal fat determination is used as the gold standard to document the presence of steatorrhea. Although the Sudan stain for fecal fat is advocated as a sensitive screening test, a quantitative correlation between the 72-h fecal fat quantitation and the fecal Sudan stain is lacking. This study was designed to examine the staining properties of different classes of purified lipids in an experimentally defined artificial matrix, and to elucidate the reasons for the lack of quantitative correlation between these two tests. Our results indicate that the "neutral fat" stain without acidification or heating identifies triglyceride; and at an appropriate pH, the "neutral stain" also identifies fatty acid. The "split fat" stain with acidification and heating identifies both triglyceride and fatty acid. After acidification, fatty acid soaps are converted to the nonionized fatty acid. Thus, fatty acid soaps can be identified indirectly as fat droplets that are stained by the split fat stain. Although cholesterol is stained with Sudan stain after heating, upon cooling, cholesterol forms crystals of anhydrous cholesterol, making its staining pattern distinct. Neither the neutral fat nor the split fat stain can detect phospholipid or cholesteryl ester. The 72-h fecal fat determination is a measure of the total fatty acid content after a specimen is saponified. The resulting fatty acids are derived from a variety of endogenous and exogenous sources, including free fatty acids, soaps of fatty acids, triglycerides, cholesterol esters, and phospholipids. Therefore, the 72-h fecal fat quantitation does not differentiate between the primary sources of the measured fatty acid. It is concluded that the 72-h fecal fat determination is not specific for documenting triglyceride (fat) malabsorption. Until new methods are developed that specifically measure fecal triglyceride and fatty acid, the Sudan stain of fecal fat appears to be a more specific method for detecting the presence of triglyceride and fatty acid in a matrix.

Antibacterial mode of action of violacein from Chromobacterium violaceum UTM5 against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA).

PubMed

Aruldass, Claira Arul; Masalamany, Santhana Raj Louis; Venil, Chidambaram Kulandaisamy; Ahmad, Wan Azlina

2018-02-01

Violacein, violet pigment produced by Chromobacterium violaceum, has attracted much attention recently due to its pharmacological properties including antibacterial activity. The present study investigated possible antibacterial mode of action of violacein from C. violaceum UTM5 against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. Violet fraction was obtained by cultivating C. violaceum UTM5 in liquid pineapple waste medium, extracted, and fractionated using ethyl acetate and vacuum liquid chromatography technique. Violacein was quantified as major compound in violet fraction using HPLC analysis. Violet fraction displayed bacteriostatic activity against S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 with minimum inhibitory concentration (MIC) of 3.9 μg/mL. Fluorescence dyes for membrane damage and scanning electron microscopic analysis confirmed the inhibitory effect by disruption on membrane integrity, morphological alternations, and rupture of the cell membranes of both strains. Transmission electron microscopic analysis showed membrane damage, mesosome formation, and leakage of intracellular constituents of both bacterial strains. Mode of action of violet fraction on the cell membrane integrity of both strains was shown by release of protein, K + , and extracellular adenosine 5'-triphosphate (ATP) with 110.5 μg/mL, 2.34 μg/mL, and 87.24 ng/μL, respectively, at 48 h of incubation. Violet fraction was toxic to human embryonic kidney (HEK293) and human fetal lung fibroblast (IMR90) cell lines with LC 50 value of 0.998 ± 0.058 and 0.387 ± 0.002 μg/mL, respectively. Thus, violet fraction showed a strong antibacterial property by disrupting the membrane integrity of S. aureus and MRSA strains. This is the first report on the possible mode of antibacterial action of violet fraction from C. violaceum UTM5 on S. aureus and MRSA strains.

Engineering cell-fluorescent ion track hybrid detectors.

PubMed

Niklas, Martin; Greilich, Steffen; Melzig, Claudius; Akselrod, Mark S; Debus, Jürgen; Jäkel, Oliver; Abdollahi, Amir

2013-06-11

The lack of sensitive biocompatible particle track detectors has so far limited parallel detection of physical energy deposition and biological response. Fluorescent nuclear track detectors (FNTDs) based on Al₂O₃:C,Mg single crystals combined with confocal laser scanning microscopy (CLSM) provide 3D information on ion tracks with a resolution limited by light diffraction. Here we report the development of next generation cell-fluorescent ion track hybrid detectors (Cell-Fit-HD). The biocompatibility of FNTDs was tested using six different cell lines, i.e. human non-small cell lung carcinoma (A549), glioblastoma (U87), androgen independent prostate cancer (PC3), epidermoid cancer (A431) and murine (VmDk) glioma SMA-560. To evaluate cell adherence, viability and conformal coverage of the crystals different seeding densities and alternative coating with extracellular matrix (fibronectin) was tested. Carbon irradiation was performed in Bragg peak (initial 270.55 MeV u⁻¹). A series of cell compartment specific fluorescence stains including nuclear (HOECHST), membrane (Glut-1), cytoplasm (Calcein AM, CM-DiI) were tested on Cell-Fit-HDs and a single CLSM was employed to co-detect the physical (crystal) as well as the biological (cell layer) information. The FNTD provides a biocompatible surface. Among the cells tested, A549 cells formed the most uniform, viable, tightly packed epithelial like monolayer. The ion track information was not compromised in Cell-Fit-HD as compared to the FNTD alone. Neither cell coating and culturing, nor additional staining procedures affected the properties of the FNTD surface to detect ion tracks. Standard immunofluorescence and live staining procedures could be employed to co-register cell biology and ion track information. The Cell-Fit-Hybrid Detector system is a promising platform for a multitude of studies linking biological response to energy deposition at high level of optical microscopy resolution.

Topical gentian violet compared to nystatin oral suspension for the treatment of oropharyngeal candidiasis in HIV-1 Infected participants

PubMed Central

Mukherjee, Pranab K; Chen, Huichao; Patton, Lauren L; Evans, Scott; Lee, Anthony; Kumwenda, Johnstone; Hakim, James; Masheto, Gaerolwe; Sawe, Frederick; Pho, Mai T; Freedberg, Kenneth A; Shiboski, Caroline H; Ghannoum, Mahmoud A; Salata, Robert A

2016-01-01

Objective Compare the safety and efficacy of topical gentian violet (GV) to that of nystatin oral suspension (NYS) for the treatment of oropharyngeal candidiasis (OC) in HIV-1 infected adults in resource-limited settings. Design Multicenter, open-label, evaluator-blinded, randomized clinical trial at 8 international sites, within the AIDS Clinical Trials Group. Study participants and Intervention Adult HIV-infected participants with OC, stratified by CD4 cell counts and antiretroviral therapy status at study entry, were randomized to receive either GV (0.00165%, BID) or NYS (500,000 units, QID) for 14 days. Main outcome measure(s) Cure or improvement after 14 days of treatment. Signs and symptoms of OC were evaluated in an evaluator-blinded manner. Results The study was closed early per DSMB after enrolling 221 participants (target = 494). Among the 182 participants eligible for efficacy analysis, 63 (68.5%) in the GV arm had cure or improvement of OC versus 61 (67.8%) in the NYS arm, resulting in a non-sizable difference of 0.007 (95% CI: -0.129, 0.143). There was no sizable difference in cure rates between the two arms (-0.0007; 95% CI: -0.146, 0.131). No GV-related adverse events were noted. No sizable differences were identified in tolerance, adherence, quality of life, or acceptability of study drugs. In GV arm, 61% and 39% of participants reported “no” and “mild-to-moderate” staining, respectively. Cost for medication procurement was significantly lower for GV versus NYS [Median $2.51 and $19.42, respectively, P = 0.01]. Conclusions Efficacy of GV was not statistically different than NYS, was well-tolerated, and its procurement cost was substantially less than NYS. PMID:27677161

Molecular epidemiology of coagulase-negative bloodstream isolates: detection of Staphylococcus epidermidis ST2, ST7 and linezolid-resistant ST23.

PubMed

Martínez-Meléndez, Adrián; Morfín-Otero, Rayo; Villarreal-Treviño, Licet; Camacho-Ortíz, Adrián; González-González, Gloria; Llaca-Díaz, Jorge; Rodríguez-Noriega, Eduardo; Garza-González, Elvira

2016-01-01

The mechanisms contributing to persistence of coagulase-negative staphylococci are diverse; to better understanding of their dynamics, the characterization of nosocomial isolates is needed. Our aim was to characterize phenotypic and molecular characteristics of Staphylococcus epidermidis and Staphylococcus haemolyticus human blood isolates from two tertiary care hospitals in Mexico, the Hospital Universitario in Monterrey and the Hospital Civil in Guadalajara. Antimicrobial susceptibility was determined. Biofilm formation was assessed by crystal violet staining. Detection of the ica operon and Staphylococcal Cassette Chromosome mec typing were performed by PCR. Clonal relatedness was determined by Pulsed-fiel gel electrophoresis and Multi locus sequence typing. Methicillin-resistance was 85.5% and 93.2% for S. epidermidis and S. haemolyticus, respectively. Both species showed resistance >70% to norfloxacin, clindamycin, levofloxacin, trimethoprim/sulfamethoxazole, and erythromycin. Three S. epidermidis and two S. haemolyticus isolates were linezolid-resistant (one isolate of each species was cfr+). Most isolates of both species were strong biofilm producers (92.8% of S. epidermidis and 72.9% of S. haemolyticus). The ica operon was amplified in 36 (43.4%) S. epidermidis isolates. SCCmec type IV was found in 47.2% of the S. epidermidis isolates and SCCmec type V in 14.5% of S. haemolyticus isolates. No clonal relatedness was found in either species. Resistance to clindamycin, levofloxacin, erythromycin, oxacillin, and cefoxitin was associated with biofilm production for both species (p<0.05). A G2576T mutation in 23S rRNA gene was detected in an S. haemolyticus linezolid-resistant isolate. All linezolid-resistant S. epidermidis isolates belonged to ST23; isolate with SCCmec type IV belonged to ST7, and isolate with SCCmec type III belonged to ST2. This is the first report of ST7 in Mexico. There was a high genetic diversity in both species, though both species shared characteristics that may contibute to virulence. Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

Comparative in vitro efficacies of ethanol-, EDTA- and levofloxacin-based catheter lock solutions on eradication of Stenotrophomonas maltophilia biofilms.

PubMed

Passerini de Rossi, Beatriz; Feldman, Laureana; Pineda, María Saliba; Vay, Carlos; Franco, Mirta

2012-09-01

The aim of this study was to compare the in vitro activity of ethanol, EDTA and levofloxacin (Levo), alone or in combination, on biofilms of Stenotrophomonas maltophilia recovered from patients with catheter-related bloodstream infections (CRBSIs) at a university hospital in Argentina. First, 24 and 48 h biofilms were formed in microtitre plates and challenged with 25 or 40 % ethanol for 1 h. Biofilms, of the 14 local isolates and from the reference strain K279a, were eradicated after both treatments as shown by plate counts and the regrowth technique. Second, 24 h biofilms of all isolates were established in silicone catheter segments and challenged with 25 or 40 % ethanol, Levo (2.5 mg ml(-1)), EDTA (30 mg ml(-1)), 25 % ethanol-EDTA or Levo-EDTA for 1, 3 and 24 h. Viable counts of biofilms treated for 1 h with 25 or 40 % ethanol or 25 % ethanol-EDTA were under the limit of detection. Killing of biofilms by Levo or Levo-EDTA was gradual and it was only after 24 h of treatment that no differences could be seen between the effects of these catheter lock solutions (CLSs) and those of ethanol (P>0.05). Levo-EDTA, in combination, did not act synergistically against biofilms. After 24 h of exposure, EDTA did not eradicate biofilms but reduced biofilm survival rates to 1-5 %. The effect of the different CLSs on biomass reduction, estimated by crystal violet staining, was highly dependent on the isolate, and the most effective agents were 25 and 40 % ethanol. Our results suggest that when used as a CLS for short periods, ethanol at low concentrations, alone or in combination with a chelator, can decontaminate the line from S. maltophilia in cases of CRBSI and help, in conjunction with systemic antibiotics, in the retention of precious vascular catheters.

Effective treatment of chemoresistant breast cancer in vitro and in vivo by a factor VII-targeted photodynamic therapy.

PubMed

Duanmu, J; Cheng, J; Xu, J; Booth, C J; Hu, Z

2011-04-26

The purpose of this study was to test a novel, dual tumour vascular endothelial cell (VEC)- and tumour cell-targeting factor VII-targeted Sn(IV) chlorin e6 photodynamic therapy (fVII-tPDT) by targeting a receptor tissue factor (TF) as an alternative treatment for chemoresistant breast cancer using a multidrug resistant (MDR) breast cancer line MCF-7/MDR. The TF expression by the MCF-7/MDR breast cancer cells and tumour VECs in MCF-7/MDR tumours from mice was determined separately by flow cytometry and immunohistochemistry using anti-human or anti-murine TF antibodies. The efficacy of fVII-tPDT was tested in vitro and in vivo and was compared with non-targeted PDT for treatment of chemoresistant breast cancer. The in vitro efficacy was determined by a non-clonogenic assay using crystal violet staining for monolayers, and apoptosis and necrosis were assayed to elucidate the underlying mechanisms. The in vivo efficacy of fVII-tPDT was determined in a nude mouse model of subcutaneous MCF-7/MDR tumour xenograft by measuring tumour volume. To our knowledge, this is the first presentation showing that TF was expressed on tumour VECs in chemoresistant breast tumours from mice. The in vitro efficacy of fVII-tPDT was 12-fold stronger than that of ntPDT for MCF-7/MDR cancer cells, and the mechanism of action involved induction of apoptosis and necrosis. Moreover, fVII-tPDT was effective and safe for the treatment of chemoresistant breast tumours in the nude mouse model. We conclude that fVII-tPDT is effective and safe for the treatment of chemoresistant breast cancer, presumably by simultaneously targeting both the tumour neovasculature and chemoresistant cancer cells. Thus, this dual-targeting fVII-tPDT could also have therapeutic potential for the treatment of other chemoresistant cancers.

Comparison of the antibiotic activities of Daptomycin, Vancomycin, and the investigational Fluoroquinolone Delafloxacin against biofilms from Staphylococcus aureus clinical isolates.

PubMed

Siala, Wafi; Mingeot-Leclercq, Marie-Paule; Tulkens, Paul M; Hallin, Marie; Denis, Olivier; Van Bambeke, Françoise

2014-11-01

Biofilm-related infections remain a scourge. In an in vitro model of biofilms using Staphylococcus aureus reference strains, delafloxacin and daptomycin were found to be the most active among the antibiotics from 8 different pharmacological classes (J. Bauer, W. Siala, P. M. Tulkens, and F. Van Bambeke, Antimicrob. Agents Chemother. 57:2726-2737, 2013, doi:10.1128/AAC.00181-13). In this study, we compared delafloxacin to daptomycin and vancomycin using biofilms produced by 7 clinical strains (S. aureus epidemic clones CC5 and CC8) in order to rationalize the differences observed between the antibiotics and strains. The effects of the antibiotics on bacterial viability (resazurin reduction assay) and biomass (crystal violet staining) were measured and correlated with the proportion of polysaccharides in the matrix, the local microenvironmental pH (micro-pH), and the antibiotic penetration in the biofilm. At clinically meaningful concentrations, delafloxacin, daptomycin, and vancomycin caused a ≥25% reduction in viability against the biofilms formed by 5, 4, and 3 strains, respectively. The antibiotic penetration within the biofilms ranged from 0.6 to 52% for delafloxacin, 0.2 to 10% for daptomycin, and 0.2 to 1% for vancomycin; for delafloxacin, this was inversely related to the polysaccharide proportion in the matrix. Six biofilms were acidic, explaining the high potency of delafloxacin (lower MICs at acidic pH). Norspermidine and norspermine (disassembling the biofilm matrix) drastically increased delafloxacin potency and efficacy (50% reduction in viability for 6 biofilms at clinically meaningful concentrations) in direct correlation with its increased penetration within the biofilm, while they only modestly improved daptomycin efficacy (50% reduction in viability for 2 biofilms) and penetration, and they showed marginal effects with vancomycin. Delafloxacin potency and efficacy against biofilms are benefited by its penetration into the matrix and the local acidic micro-pH. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Comparison of the Antibiotic Activities of Daptomycin, Vancomycin, and the Investigational Fluoroquinolone Delafloxacin against Biofilms from Staphylococcus aureus Clinical Isolates

PubMed Central

Siala, Wafi; Mingeot-Leclercq, Marie-Paule; Tulkens, Paul M.; Hallin, Marie; Denis, Olivier

2014-01-01

Biofilm-related infections remain a scourge. In an in vitro model of biofilms using Staphylococcus aureus reference strains, delafloxacin and daptomycin were found to be the most active among the antibiotics from 8 different pharmacological classes (J. Bauer, W. Siala, P. M. Tulkens, and F. Van Bambeke, Antimicrob. Agents Chemother. 57:2726–2737, 2013, doi:10.1128/AAC.00181-13). In this study, we compared delafloxacin to daptomycin and vancomycin using biofilms produced by 7 clinical strains (S. aureus epidemic clones CC5 and CC8) in order to rationalize the differences observed between the antibiotics and strains. The effects of the antibiotics on bacterial viability (resazurin reduction assay) and biomass (crystal violet staining) were measured and correlated with the proportion of polysaccharides in the matrix, the local microenvironmental pH (micro-pH), and the antibiotic penetration in the biofilm. At clinically meaningful concentrations, delafloxacin, daptomycin, and vancomycin caused a ≥25% reduction in viability against the biofilms formed by 5, 4, and 3 strains, respectively. The antibiotic penetration within the biofilms ranged from 0.6 to 52% for delafloxacin, 0.2 to 10% for daptomycin, and 0.2 to 1% for vancomycin; for delafloxacin, this was inversely related to the polysaccharide proportion in the matrix. Six biofilms were acidic, explaining the high potency of delafloxacin (lower MICs at acidic pH). Norspermidine and norspermine (disassembling the biofilm matrix) drastically increased delafloxacin potency and efficacy (50% reduction in viability for 6 biofilms at clinically meaningful concentrations) in direct correlation with its increased penetration within the biofilm, while they only modestly improved daptomycin efficacy (50% reduction in viability for 2 biofilms) and penetration, and they showed marginal effects with vancomycin. Delafloxacin potency and efficacy against biofilms are benefited by its penetration into the matrix and the local acidic micro-pH. PMID:25114142

Dose-dependent effect of lysozyme upon Candida albicans biofilm

PubMed Central

Sebaa, Sarra; Hizette, Nicolas; Boucherit-Otmani, Zahia; Courtois, Philippe

2017-01-01

The present study investigated the in vitro effect of lysozyme (0–1,000 µg/ml) on Candida albicans (C. albicans) biofilm development. Investigations were conducted on C. albicans ATCC 10231 and on 10 clinical isolates from dentures. Strains were cultured aerobically at 37°C in Sabouraud broth. Yeast growth was evaluated by turbidimetry. Biofilm biomass was quantified on a polystyrene support by crystal violet staining and on acrylic surfaces by counts of colony forming units. Lysozyme affected biofilm formation to a greater extent than it affected growth. For the ATCC 10231 reference strain, lysozyme acted as a biofilm promotor on polystyrene at the highest concentration tested (1,000 µg/ml, non-physiological). When the reference strain was investigated on acrylic resin support, lysozyme acted as a significant biofilm promotor on rough resin, but less on smooth resin. The attached biomass in the presence of physiological concentrations of lysozyme (10–30 µg/ml) was significantly decreased compared with the hypothetical value of 100% using a one-sample t-test, but a comparison between the different lysozyme conditions using analysis of variance and post hoc tests did not reveal significant differences. In 10 wild strains, different patterns of biofilm formation on polystyrene were observed in the presence of lysozyme. Some strains, characterized by large amounts of biofilm formation in the presence of 1,000 µg/ml lysozyme, were poor biofilm producers at low concentrations of lysozyme. In contrast, some strains that were poor biofilm producers with a high lysozyme concentration were more inhibited by low concentrations of lysozyme. The present study emphasizes the need to develop strategies for biofilm control based on in vitro experiments, and to implement these in clinical trials prior to approval of hygiene products enriched with exocrine proteins, such as lysozyme. Further studies will extend these investigations to other Candida species, and to fungi and bacteria present in oral biofilms. PMID:28138698

Disparate effects of non-steroidal anti-inflammatory drugs on apoptosis in guinea-pig gastric mucous cells: inhibition of basal apoptosis by diclofenac

PubMed Central

Ashton, Miranda; Hanson, Peter J

2002-01-01

Non-steroidal anti-inflammatory drugs (NSAIDs) induce apoptosis in gastrointestinal cancer cell lines. Similar actions on normal gastric epithelial cells could contribute to NSAID gastropathy. The present work therefore compared the actions of diclofenac, ibuprofen, indomethacin, and the cyclo-oxygenase-2 selective inhibitor, NS-398, on a primary culture of guinea-pig gastric mucous epithelial cells. Cell number was assessed by staining with crystal violet. Apoptotic activity was determined by condensation and fragmentation of nuclei and by assay of caspase-3-like activity. Necrosis was evaluated from release of cellular enzymes. Ibuprofen (250 μM for 24 h) promoted cell loss, and apoptosis, under both basal conditions and when apoptosis was increased by 25 μM N-Hexanoyl-D-sphingosine (C6-ceramide). Diclofenac (250 μM for 24 h) reduced the proportion of apoptotic nuclei from 5.2 to 2.1%, and caused inhibition of caspase-3-like activity, without causing necrosis under basal conditions. No such reduction in apoptotic activity was evident in the presence of 25 μM C6-ceramide. The inhibitory effect of diclofenac on basal caspase-3-like activity was also exhibited by the structurally similar mefenamic and flufenamic acids (1–250 μM), but not by niflumic acid. Inhibition of superoxide production by the cells increased caspase-3-like activity, but the inhibitory action of diclofenac on caspase activity remained. Diclofenac did not affect superoxide production. Diclofenac inhibited caspase-3-like activity in cell homogenates and also inhibited human recombinant caspase-3. In conclusion, NSAIDs vary in their effect on apoptotic activity in a primary culture of guinea-pig gastric mucous epithelial cells, and the inhibitory effect of diclofenac on basal apoptosis could involve an action on caspase activity. PMID:11815376

Dual action of highbush blueberry proanthocyanidins on Aggregatibacter actinomycetemcomitans and the host inflammatory response.

PubMed

Ben Lagha, Amel; LeBel, Geneviève; Grenier, Daniel

2018-01-10

The highbush blueberry (Vaccinium corymbosum) has a beneficial effect on several aspects of human health. The present study investigated the effects of highbush blueberry proanthocyanidins (PACs) on the virulence properties of Aggregatibacter actinomycetemcomitans and macrophage-associated inflammatory responses. PACs were isolated from frozen highbush blueberries using solid-phase chromatography. A microplate dilution assay was performed to determine the effect of highbush blueberry PACs on A. actinomycetemcomitans growth as well as biofilm formation stained with crystal violet. Tight junction integrity of oral keratinocytes was assessed by measuring the transepithelial electrical resistance (TER), while macrophage viability was determined with a colorimetric MTT assay. Pro-inflammatory cytokine and MMP secretion by A. actinomycetemcomitans-stimulated macrophages was quantified by ELISA. The U937-3xκB-LUC monocyte cell line transfected with a luciferase reporter gene was used to monitor NF-κB activation. Highbush blueberry PACs reduced the growth of A. actinomycetemcomitans and prevented biofilm formation at sub-inhibitory concentrations. The treatment of pre-formed biofilms with the PACs resulted in a loss of bacterial viability. The antibacterial activity of the PACs appeared to involve damage to the bacterial cell membrane. The PACs protected the oral keratinocytes barrier integrity from damage caused by A. actinomycetemcomitans. The PACs also protected macrophages from the deleterious effect of leukotoxin Ltx-A and dose-dependently inhibited the secretion of pro-inflammatory cytokines (IL-1β, IL-6, CXCL8, TNF-α), matrix metalloproteinases (MMP-3, MMP-9), and sTREM-1 by A. actinomycetemcomitans-treated macrophages. The PACs also inhibited the activation of the NF-κB signaling pathway. The antibacterial and anti-inflammatory properties of highbush blueberry PACs as well as their ability to protect the oral keratinocyte barrier and neutralize leukotoxin activity suggest that they may be promising candidates as novel therapeutic agents.

Characterisation of a collection of Streptococcus pneumoniae isolates from patients suffering from acute exacerbations of chronic bronchitis: in vitro susceptibility to antibiotics and biofilm formation in relation to antibiotic efflux and serotypes/serogroups.

PubMed

Vandevelde, Nathalie M; Tulkens, Paul M; Diaz Iglesias, Yvan; Verhaegen, Jan; Rodriguez-Villalobos, Hector; Philippart, Ivan; Cadrobbi, Julie; Coppens, Nathalie; Boel, An; Van Vaerenbergh, Kristien; Francart, Hugo; Vanhoof, Raymond; Liistro, Giuseppe; Jordens, Paul; d'Odemont, Jean-Paul; Valcke, Yvan; Verschuren, Franck; Van Bambeke, Françoise

2014-09-01

The correlation between Streptococcus pneumoniae serotypes, biofilm production, antibiotic susceptibility and drug efflux in isolates from patients suffering from acute exacerbations of chronic bronchitis (AECB) remains largely unexplored. Using 101 isolates collected from AECB patients for whom partial (n=51) or full (n=50) medical details were available, we determined serotypes (ST)/serogroups (SG) (Quellung reaction), antibiotic susceptibility patterns [MIC (microdilution) using EUCAST and CLSI criteria] and ability to produce biofilm in vitro (10-day model; crystal violet staining). The majority of patients were 55-75 years old and <5% were vaccinated against S. pneumoniae. Moreover, 54% showed high severity scores (GOLD 3-4), and comorbidities were frequent including hypertension (60%), cancer (24%) and diabetes (20%). Alcohol and/or tobacco dependence was >30%. Isolates of SG6-11-15-23, known for large biofilm production and causing chronic infections, were the most prevalent (>15% each), but other isolates also produced biofilm (SG9-18-22-27 and ST8-20 being most productive), except SG7, SG29 and ST5 (<2% of isolates each). Resistance (EUCAST breakpoints) was 8-13% for amoxicillin and cefuroxime, 35-39% for macrolides, 2-8% for fluoroquinolones and 2% for telithromycin. ST19A isolates showed resistance to all antibiotics, ST14 to all except moxifloxacin, and SG9 and SG19 to all except telithromycin, moxifloxacin and ceftriaxone (SG19 only). Solithromycin and telithromycin MICs were similar. No correlation was observed between biofilm production and MIC or efflux (macrolides, fluoroquinolones). S. pneumoniae serotyping may improve AECB treatment by avoiding antibiotics with predictable low activity, but it is not predictive of biofilm production. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

A procedure for quantifying adhesion of conidia of Botrytis cinerea to the skin of apple fruit.

PubMed

Filonow, A B

2001-08-01

Ultrasonication was evaluated as a nonchemical means to quantitatively remove conidia of Botrytis cinerea from the skin of Golden Delicious apple (Malus domestica Borkh.) fruit. A probe immersed in a suspension of conidia and generating 20 kHz at 150 W for 30- or 60-s pulses destroyed 13.3% or 29% of conidia, respectively. Destruction at 150 W for 10 s or at 30-120 W for up to 60 s was <2%. The procedure for quantifying adhesion of conidia to the skin of fruit consisted of pipetting a 50-microL water droplet containing 5 x 10(4) conidia onto the skinside of a slice of fruit, incubating the slices inside sealed 500 cm3 glass jars, excising a 1 cm diameter piece of skin bearing the droplet, and sonicating the skin in 8 mL of ice-cold water at 150 W for 10 s. The skin was removed, the suspension was centrifuged at 1250 x g for 15 min, and the supernatant was reduced to 1 mL by vacuum suction using a pipet. Conidia were stained with crystal violet and counted in a hemacytometer. Adhesion of conidia to skin was 3.0%, 14.6%, 20.8%, 39.4%, 57.6%, and 73.1% after 0, 2, 4, 8, 12, and 24 h incubation, respectively. Sonication was more effective than two other procedures for recovery of conidia. Conidia on the skin of fruit exposed to 4 microL of butyl acetate in the headspace of glass jars for 4 h at 23 degrees C increased the adhesion of conidia 107% above that for unexposed conidia. Sonication with a programmable power- and time-controlled probe was a simple, rapid, safe, and effective method for quantifying adhesion of B. cinerea conidia to the skin of apple fruit.

The activity of ferulic and gallic acids in biofilm prevention and control of pathogenic bacteria.

PubMed

Borges, Anabela; Saavedra, Maria J; Simões, Manuel

2012-01-01

The activity of two phenolic acids, gallic acid (GA) and ferulic acid (FA) at 1000 μg ml(-1), was evaluated on the prevention and control of biofilms formed by Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. In addition, the effect of the two phenolic acids was tested on planktonic cell susceptibility, bacterial motility and adhesion. Biofilm prevention and control were tested using a microtiter plate assay and the effect of the phenolic acids was assessed on biofilm mass (crystal violet staining) and on the quantification of metabolic activity (alamar blue assay). The minimum bactericidal concentration for P. aeruginosa was 500 μg ml(-1) (for both phenolic acids), whilst for E. coli it was 2500 μg ml(-1) (FA) and 5000 μg ml(-1) (GA), for L. monocytogenes it was >5000 μg ml(-1) (for both phenolic acids), and for S. aureus it was 5000 μg ml(-1) (FA) and >5000 μg ml(-1) (GA). GA caused total inhibition of swimming (L. monocytogenes) and swarming (L. monocytogenes and E. coli) motilities. FA caused total inhibition of swimming (L. monocytogenes) and swarming (L. monocytogenes and E. coli) motilities. Colony spreading of S. aureus was completely inhibited by FA. The interference of GA and FA with bacterial adhesion was evaluated by the determination of the free energy of adhesion. Adhesion was less favorable when the bacteria were exposed to GA (P. aeruginosa, S. aureus and L. monocytogenes) and FA (P. aeruginosa and S. aureus). Both phenolics had preventive action on biofilm formation and showed a higher potential to reduce the mass of biofilms formed by the Gram-negative bacteria. GA and FA promoted reductions in biofilm activity >70% for all the biofilms tested. The two phenolic acids demonstrated the potential to inhibit bacterial motility and to prevent and control biofilms of four important human pathogenic bacteria. This study also emphasizes the potential of phytochemicals as an emergent source of biofilm control products.

Variability of Listeria monocytogenes strains in biofilm formation on stainless steel and polystyrene materials and resistance to peracetic acid and quaternary ammonium compounds.

PubMed

Poimenidou, Sofia V; Chrysadakou, Marilena; Tzakoniati, Aikaterini; Bikouli, Vasiliki C; Nychas, George-John; Skandamis, Panagiotis N

2016-11-21

Listeria monocytogenes is a foodborne pathogen able to tolerate adverse conditions by forming biofilms or by deploying stress resistant mechanisms, and thus manages to survive for long periods in food processing plants. This study sought to investigate the correlation between biofilm forming ability, tolerance to disinfectants and cell surface characteristics of twelve L. monocytogenes strains. The following attributes were evaluated: (i) biofilm formation by crystal violet staining method on polystyrene, and by standard cell enumeration on stainless steel and polystyrene; (ii) hydrophobicity assay using solvents; (iii) minimum inhibitory concentration (MIC) and biofilm eradication concentration (BEC) of peracetic acid (PAA) and quaternary ammonium compounds (QACs), and (iv) resistance to sanitizers (PAA 2000ppm; QACs 500ppm) of biofilms on polystyrene and stainless steel. After 72h of incubation, higher biofilm levels were formed in TSB at 20°C, followed by TSB at 37°C (P=0.087) and diluted TSB 1/10 at both 20 (P=0.005) and 37°C (P=0.004). Cells grown at 30°C to the stationary phase had significant electron donating nature and a low hydrophobicity, while no significant correlation of cell surface properties to biofilm formation was observed. Strains differed in MIC PAA and BEC PAA by 24- and 15-fold, respectively, while a positive correlation between MIC PAA and BEC PAA was observed (P=0.02). The MIC QACs was positively correlated with the biofilm-forming ability on stainless steel (P=0.03). Regarding the impact of surface type, higher biofilm populations were enumerated on polystyrene than on stainless steel, which were also more tolerant to disinfectants. Among all strains, the greatest biofilm producer was a persistent strain with significant tolerance to QACs. These results may contribute to better understanding of L. monocytogenes behavior and survival on food processing surfaces. Copyright © 2016 Elsevier B.V. All rights reserved.

Relevance of the clustered regularly interspaced short palindromic repeats of Enterococcus faecalis strains isolated from retreatment root canals on periapical lesions, resistance to irrigants and biofilms

PubMed Central

Tong, Zhongchun; Du, Yu; Ling, Junqi; Huang, Lijia; Ma, Jinglei

2017-01-01

A high prevalence of Enterococcus faecalis (E. faecalis) is observed in teeth with root canal treatment failures. Clustered regularly interspaced short palindromic repeats (CRISPR) are widely distributed in prokaryotes that have adaptive immune systems against mobile elements, including pathogenic genes. The present study investigated the relevance of the CRISPR in E. faecalis strains isolated from retreated root canals on biofilms, periapical lesions and drug resistance. A total of 20 E. faecalis strains were extracted from the root canals of teeth referred for root canal retreatment. CRISPR-Cas loci were identified by two pairs of relevant primers and polymerase chain reaction. The susceptibility of the 20 isolated strains to intracanal irrigants was evaluated by 1- and 5-minute challenges with a mixture of a tetracycline isomer, an acid and a detergent (MTAD), 2% chlorhexidine (CHX) and 5.25% sodium hypochlorite (NaOCl). The microtiter plate assay and crystal violet staining were used to compare the biofilm formation of the E. faecalis isolate strains. Out of the 20 E. faecalis isolate strains, 5 strains that lacked CRISPR-cas determinants exhibited significant periapical lesions. Among the 15 strains containing CRISPR-cas determinants, 8 were isolated from root canals with inadequate fillings and 7 were isolated from root canals without any fillings. The five strains lacking CRISPR-cas loci were observed to be more resistant to MTAD and 2% CHX than the 15 strains that had CRISPR-cas loci. All of the strains exhibited the same susceptibility to 5.25% NaOCl. Furthermore, the 5 strains lacking CRISPR-cas determinants generated more biofilm than the other 15 strains. Thus, the results of the present study suggested that E. faecalis root canal isolates lacking CRISPR-cas exhibit higher resistance to intracanal irrigants, stronger biofilm formation and generate significant periapical lesions. PMID:29285081

Relevance of the clustered regularly interspaced short palindromic repeats of Enterococcus faecalis strains isolated from retreatment root canals on periapical lesions, resistance to irrigants and biofilms.

PubMed

Tong, Zhongchun; Du, Yu; Ling, Junqi; Huang, Lijia; Ma, Jinglei

2017-12-01

A high prevalence of Enterococcus faecalis ( E. faecalis ) is observed in teeth with root canal treatment failures. Clustered regularly interspaced short palindromic repeats (CRISPR) are widely distributed in prokaryotes that have adaptive immune systems against mobile elements, including pathogenic genes. The present study investigated the relevance of the CRISPR in E. faecalis strains isolated from retreated root canals on biofilms, periapical lesions and drug resistance. A total of 20 E. faecalis strains were extracted from the root canals of teeth referred for root canal retreatment. CRISPR-Cas loci were identified by two pairs of relevant primers and polymerase chain reaction. The susceptibility of the 20 isolated strains to intracanal irrigants was evaluated by 1- and 5-minute challenges with a mixture of a tetracycline isomer, an acid and a detergent (MTAD), 2% chlorhexidine (CHX) and 5.25% sodium hypochlorite (NaOCl). The microtiter plate assay and crystal violet staining were used to compare the biofilm formation of the E. faecalis isolate strains. Out of the 20 E. faecalis isolate strains, 5 strains that lacked CRISPR-cas determinants exhibited significant periapical lesions. Among the 15 strains containing CRISPR-cas determinants, 8 were isolated from root canals with inadequate fillings and 7 were isolated from root canals without any fillings. The five strains lacking CRISPR-cas loci were observed to be more resistant to MTAD and 2% CHX than the 15 strains that had CRISPR-cas loci. All of the strains exhibited the same susceptibility to 5.25% NaOCl. Furthermore, the 5 strains lacking CRISPR-cas determinants generated more biofilm than the other 15 strains. Thus, the results of the present study suggested that E. faecalis root canal isolates lacking CRISPR-cas exhibit higher resistance to intracanal irrigants, stronger biofilm formation and generate significant periapical lesions.

Anti-tumour activity of two novel compounds in cisplatin-resistant testicular germ cell cancer.

PubMed

Nitzsche, B; Gloesenkamp, C; Schrader, M; Hoffmann, B; Zengerling, F; Balabanov, S; Honecker, F; Höpfner, M

2012-11-20

Resistance to cisplatin-based chemotherapy is associated with poor prognosis in testicular germ cell cancer, emphasising the need for new therapeutic approaches. In this respect, the therapeutic concept of anti-angiogenesis is of particular interest. In a previous study, we presented two novel anti-angiogenic compounds, HP-2 and HP-14, blocking the tyrosine kinase activity of angiogenic growth factor receptors, such as vascular endothelial growth factor receptor-2 (VEGFR-2), and related signalling pathways in testicular cancer. In this study, we investigated the efficacy of these new compounds in platinum-resistant testicular germ cell tumours (TGCTs), in vitro and in vivo. Drug-induced changes in cell proliferation of the cisplatin-sensitive TGCT cell line 2102EP and its cisplatin-resistant counterpart 2102EP-R, both expressing the VEGFR-2, were evaluated by crystal violet staining. Both compounds inhibited the growth of cisplatin-resistant TGCT cells in a dose-dependent manner. In combination experiments with cisplatin, HP-14 revealed additive growth-inhibitory effects in TGCT cells, irrespective of the level of cisplatin resistance. Anti-angiogenic effects of HP compounds were confirmed by tube formation assays with freshly isolated human umbilical vein endothelial cells. Using TGCT cells inoculated onto the chorioallantoic membrane of fertilised chicken eggs (chicken chorioallantoic membrane assay), the anti-angiogenic and anti-proliferative potency of the novel compounds was also demonstrated in vivo. Gene expression profiling revealed changes in the expression pattern of genes related to DNA damage detection and repair, as well as in chaperone function after treatment with both cisplatin and HP-14, alone or in combination. This suggests that HP-14 can revert the lost effectiveness of cisplatin in the resistant cells by altering the expression of critical genes. The novel compound HP-14 effectively inhibits the growth of cisplatin-resistant TGCT cells and suppresses tumour angiogenesis. Thus, HP-14 may be an interesting new agent that should be further explored for TGCT treatment, especially in TGCTs that are resistant to cisplatin.

Evaluation and Selection of Bacillus Species Based on Enzyme Production, Antimicrobial Activity, and Biofilm Synthesis as Direct-Fed Microbial Candidates for Poultry

PubMed Central

Latorre, Juan D.; Hernandez-Velasco, Xochitl; Wolfenden, Ross E.; Vicente, Jose L.; Wolfenden, Amanda D.; Menconi, Anita; Bielke, Lisa R.; Hargis, Billy M.; Tellez, Guillermo

2016-01-01

Social concern about misuse of antibiotics as growth promoters (AGP) and generation of multidrug-resistant bacteria have restricted the dietary inclusion of antibiotics in livestock feed in several countries. Direct-fed microbials (DFM) are one of the multiple alternatives commonly evaluated as substitutes of AGP. Sporeformer bacteria from the genus Bacillus have been extensively investigated because of their extraordinary properties to form highly resistant endospores, produce antimicrobial compounds, and synthesize different exogenous enzymes. The purpose of the present study was to evaluate and select Bacillus spp. from environmental and poultry sources as DFM candidates, considering their enzyme production profile, biofilm synthesis capacity, and pathogen-inhibition activity. Thirty-one Bacillus isolates were screened for in vitro relative enzyme activity of amylase, protease, lipase, and phytase using a selective media for each enzyme, with 3/31 strains selected as superior enzyme producers. These three isolates were identified as Bacillus subtilis (1/3), and Bacillus amyloliquefaciens (2/3), based on biochemical tests and 16S rRNA sequence analysis. For evaluation of biofilm synthesis, the generation of an adherent crystal violet-stained ring was determined in polypropylene tubes, resulting in 11/31 strains showing a strong biofilm formation. Moreover, all Bacillus strains were evaluated for growth inhibition activity against Salmonella enterica serovar Enteritidis (26/31), Escherichia coli (28/31), and Clostridioides difficile (29/31). Additionally, in previous in vitro and in vivo studies, these selected Bacillus strains have shown to be resistant to different biochemical conditions of the gastrointestinal tract of poultry. Results of the present study suggest that the selection and consumption of Bacillus-DFM, producing a variable set of enzymes and antimicrobial compounds, may contribute to enhanced performance through improving nutrient digestibility, reducing intestinal viscosity, maintaining a beneficial gut microbiota, and promoting healthy intestinal integrity in poultry. PMID:27812526

The cabABC Operon Essential for Biofilm and Rugose Colony Development in Vibrio vulnificus

PubMed Central

Park, Jin Hwan; Jo, Youmi; Jang, Song Yee; Kwon, Haenaem; Irie, Yasuhiko; Parsek, Matthew R.; Kim, Myung Hee; Choi, Sang Ho

2015-01-01

A transcriptome analysis identified Vibrio vulnificus cabABC genes which were preferentially expressed in biofilms. The cabABC genes were transcribed as a single operon. The cabA gene was induced by elevated 3′,5′-cyclic diguanylic acid (c-di-GMP) and encoded a calcium-binding protein CabA. Comparison of the biofilms produced by the cabA mutant and its parent strain JN111 in microtiter plates using crystal-violet staining demonstrated that CabA contributed to biofilm formation in a calcium-dependent manner under elevated c-di-GMP conditions. Genetic and biochemical analyses revealed that CabA was secreted to the cell exterior through functional CabB and CabC, distributed throughout the biofilm matrix, and produced as the biofilm matured. These results, together with the observation that CabA also contributes to the development of rugose colony morphology, indicated that CabA is a matrix-associated protein required for maturation, rather than adhesion involved in the initial attachment, of biofilms. Microscopic comparison of the structure of biofilms produced by JN111 and the cabA mutant demonstrated that CabA is an extracellular matrix component essential for the development of the mature biofilm structures in flow cells and on oyster shells. Exogenously providing purified CabA restored the biofilm- and rugose colony-forming abilities of the cabA mutant when calcium was available. Circular dichroism and size exclusion analyses revealed that calcium binding induces CabA conformational changes which may lead to multimerization. Extracellular complementation experiments revealed that CabA can assemble a functional matrix only when exopolysaccharides coexist. Consequently, the combined results suggested that CabA is a structural protein of the extracellular matrix and multimerizes to a conformation functional in building robust biofilms, which may render V. vulnificus to survive in hostile environments and reach a concentrated infective dose. PMID:26406498

Inhibition and Dispersal of Pseudomonas aeruginosa Biofilms by Combination Treatment with Escapin Intermediate Products and Hydrogen Peroxide.

PubMed

Santiago, Ariel J; Ahmed, Marwa N A; Wang, Shu-Lin; Damera, Krishna; Wang, Binghe; Tai, Phang C; Gilbert, Eric S; Derby, Charles D

2016-09-01

Escapin is an l-amino acid oxidase that acts on lysine to produce hydrogen peroxide (H2O2), ammonia, and equilibrium mixtures of several organic acids collectively called escapin intermediate products (EIP). Previous work showed that the combination of synthetic EIP and H2O2 functions synergistically as an antimicrobial toward diverse planktonic bacteria. We initiated the present study to investigate how the combination of EIP and H2O2 affected bacterial biofilms, using Pseudomonas aeruginosa as a model. Specifically, we examined concentrations of EIP and H2O2 that inhibited biofilm formation or fostered disruption of established biofilms. High-throughput assays of biofilm formation using microtiter plates and crystal violet staining showed a significant effect from pairing EIP and H2O2, resulting in inhibition of biofilm formation relative to biofilm formation in untreated controls or with EIP or H2O2 alone. Similarly, flow cell analysis and confocal laser scanning microscopy revealed that the EIP and H2O2 combination reduced the biomass of established biofilms relative to that of the controls. Area layer analysis of biofilms posttreatment indicated that disruption of biomass occurs down to the substratum. Only nanomolar to micromolar concentrations of EIP and H2O2 were required to impact biofilm formation or disruption, and these concentrations are significantly lower than those causing bactericidal effects on planktonic bacteria. Micromolar concentrations of EIP and H2O2 combined enhanced P. aeruginosa swimming motility compared to the effect of either EIP or H2O2 alone. Collectively, our results suggest that the combination of EIP and H2O2 may affect biofilms by interfering with bacterial attachment and destabilizing the biofilm matrix. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Characteristics of Aspergillus fumigatus in Association with Stenotrophomonas maltophilia in an In Vitro Model of Mixed Biofilm

PubMed Central

Melloul, Elise; Luiggi, Stéphanie; Anaïs, Leslie; Arné, Pascal; Costa, Jean-Marc; Fihman, Vincent; Briard, Benoit; Dannaoui, Eric; Guillot, Jacques; Decousser, Jean-Winoc; Beauvais, Anne; Botterel, Françoise

2016-01-01

Background Biofilms are communal structures of microorganisms that have long been associated with a variety of persistent infections poorly responding to conventional antibiotic or antifungal therapy. Aspergillus fumigatus fungus and Stenotrophomonas maltophilia bacteria are examples of the microorganisms that can coexist to form a biofilm especially in the respiratory tract of immunocompromised patients or cystic fibrosis patients. The aim of the present study was to develop and assess an in vitro model of a mixed biofilm associating S. maltophilia and A. fumigatus by using analytical and quantitative approaches. Materials and Methods An A. fumigatus strain (ATCC 13073) expressing a Green Fluorescent Protein (GFP) and an S. maltophilia strain (ATCC 13637) were used. Fungal and bacterial inocula (105 conidia/mL and 106 cells/mL, respectively) were simultaneously deposited to initiate the development of an in vitro mixed biofilm on polystyrene supports at 37°C for 24 h. The structure of the biofilm was analysed via qualitative microscopic techniques like scanning electron and transmission electron microscopy, and fluorescence microscopy, and by quantitative techniques including qPCR and crystal violet staining. Results Analytic methods revealed typical structures of biofilm with production of an extracellular matrix (ECM) enclosing fungal hyphae and bacteria. Quantitative methods showed a decrease of A. fumigatus growth and ECM production in the mixed biofilm with antibiosis effect of the bacteria on the fungi seen as abortive hyphae, limited hyphal growth, fewer conidia, and thicker fungal cell walls. Conclusion For the first time, a mixed A. fumigatus—S. maltophilia biofilm was validated by various analytical and quantitative approaches and the bacterial antibiosis effect on the fungus was demonstrated. The mixed biofilm model is an interesting experimentation field to evaluate efficiency of antimicrobial agents and to analyse the interactions between the biofilm and the airways epithelium. PMID:27870863

Attachment of Porphyromonas gingivalis to corroded commercially pure titanium and titanium-aluminum-vanadium alloy.

PubMed

Barão, Valentim A R; Yoon, Cheon Joo; Mathew, Mathew T; Yuan, Judy Chia-Chun; Wu, Christine D; Sukotjo, Cortino

2014-09-01

Titanium dental material can become corroded because of electrochemical interaction in the oral environment. The corrosion process may result in surface modification. It was hypothesized that a titanium surface modified by corrosion may enhance the attachment of periodontal pathogens. This study evaluates the effects of corroded titanium surfaces on the attachment of Porphyromonas gingivalis. Commercially pure titanium (cp-Ti) and titanium-aluminum-vanadium alloy (Ti-6Al-4V) disks were used. Disks were anodically polarized in a standard three-electrode setting in a simulated oral environment with artificial saliva at pH levels of 3.0, 6.5, or 9.0. Non-corroded disks were used as controls. Surface roughness was measured before and after corrosion. Disks were inoculated with P. gingivalis and incubated anaerobically at 37°C. After 6 hours, the disks with attached P. gingivalis were stained with crystal violet, and attachment was expressed based on dye absorption at optical density of 550 nm. All assays were performed independently three times in triplicate. Data were analyzed by two-way analysis of variance, the Tukey honestly significant difference test, t test, and Pearson's correlation test (α = 0.05). Both cp-Ti and Ti-6Al-4V alloy-corroded disks promoted significantly more bacterial attachment (11.02% and 41.78%, respectively; P <0.0001) than did the non-corroded controls. Significantly more (11.8%) P. gingivalis attached to the cp-Ti disks than to the Ti-6Al-4V alloy disks (P <0.05). No significant difference in P. gingivalis attachment was noted among the corroded groups for both cp-Ti and Ti-6Al-4V alloy (P >0.05). There was no significant correlation between surface roughness and P. gingivalis attachment. A higher degree of corrosion on the titanium surface may promote increased bacterial attachment by oral pathogens.

Changes in the prevalence and biofilm formation of Haemophilus influenzae and Haemophilus parainfluenzae from the respiratory microbiota of patients with sarcoidosis.

PubMed

Kosikowska, Urszula; Rybojad, Paweł; Stępień-Pyśniak, Dagmara; Żbikowska, Anna; Malm, Anna

2016-08-26

Healthy condition and chronic diseases may be associated with microbiota composition and its properties. The prevalence of respiratory haemophili with respect to their phenotypes including the ability to biofilm formation in patients with sarcoidosis was assayed. Nasopharynx and sputum specimens were taken in 31 patients with sarcoidosis (average age 42.6 ± 13), and nasopharynx specimens were taken in 37 healthy people (average age 44.6 ± 11.6). Haemophili were identified by API-NH microtest and by the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system. Biofilm was visualised by crystal violet staining and confocal scanning laser microscopy (CSLM). The statistical analysis was performed with Statgraphics Plus for Windows. In total, 30/31 patients with sarcoidosis and 31/37 healthy people were colonized by Haemophilus influenzae (6/30 vs. 1/31) and Haemophilus parainfluenzae (28/30 vs. 31/31) in the nasopharynx. The overall number of nasopharyngeal haemophili isolates was 59 in patients with sarcoidosis and 67 in healthy volunteers (H. influenzae 6/59 vs. 1/67, P = 0.05; H. parainfluenzae 47/59 vs. 65/67, P = 0.0032). Moreover, the decreased number of H. parainfluenzae biofilm-producing isolates was shown in nasopharyngeal samples in patients with sarcoidosis as compared to healthy people (19/31 vs. 57/65, P = 0.006), especially with respect to isolates classified as strong and very strong biofilm-producers (8/31 vs. 39/65, P = 0.002). The obtained data suggest that the qualitative and quantitative changes within the respiratory microbiota concerning the overall prevalence of H. influenzae together with the decreased number of H. parainfluenzae strains and the decreased rate of H. parainfluenzae biofilm-producing isolates as compared to healthy people may be associated with sarcoidosis.

Molecular Identification, Antifungal Susceptibility Profile, and Biofilm Formation of Clinical and Environmental Rhodotorula Species Isolates

PubMed Central

Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona e

2013-01-01

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC50/MIC90, 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species. PMID:23114761

Molecular identification, antifungal susceptibility profile, and biofilm formation of clinical and environmental Rhodotorula species isolates.

PubMed

Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona E; Colombo, Arnaldo Lopes

2013-01-01

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC(50)/MIC(90), 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species.

Effect of Human Milk and its Components on Streptococcus Mutans Biofilm Formation.

PubMed

Allison, L M; Walker, L A; Sanders, B J; Yang, Z; Eckert, G; Gregory, R L

2015-01-01

This study investigated the effects of human breast milk and its components on the nutritional aspect of the caries process due to Streptococcus mutans UA159 biofilm formation. Human breast milk was collected from 11 mothers during 3-9 months postpartum. To test for the effect on biofilm formation, a 16-hour culture of S. mutans was treated with dilutions of human breast milk and several major components of human breast milk, lactose, lactoferrin, IgA, and bovine casein in sterile 96-well flat bottom microtiter plates for 24 hours. The biofilms were fixed, washed, stained with crystal violet, and extracted. Absorbance was measured to evaluate biofilm growth mass. Dilutions 1:10-1:2,560 of the human breast milk samples increased biofilm formation by 1.5-3.8 fold compared to the control. Lactoferrin decreased biofilm formation significantly in all dilutions (average milk concentration of 3 mg/ml). Lactose had no effect at average breast milk concentrations (60 mg/ml) except at its lowest concentration (15 mg/ml) where it was increased. IgA significantly decreased biofilm formation at its highest concentration of 2,400 μg/ml (average milk concentration 600 μg/ml). Casein caused significantly increased biofilm formation at all concentrations tested above the average milk content (2.3 mg/ml). The results of this study demonstrate an increase in S. mutans biofilm formation by human breast milk 3-9 months post partum. Among its major components, only casein significantly increased biofilm formation among the concentrations analyzed. Lactose had no effect except at 15 mg/ml. Lactoferrin and IgA significantly decreased S. mutans biofilm formation at their highest concentrations. This information expands the current knowledge regarding the nutritional influence of breastfeeding and validates the necessity to begin an oral hygiene regimen once the first tooth erupts.

AzaSite® inhibits Staphylococcus aureus and coagulase-negative Staphylococcus biofilm formation in vitro.

PubMed

Wu, Eric C; Kowalski, Regis P; Romanowski, Eric G; Mah, Francis S; Gordon, Y Jerold; Shanks, Robert M Q

2010-12-01

The aim of this study was to analyze the effect of azithromycin (AZM) 1% ophthalmic solution in DuraSite® (AzaSite®) on biofilm formation by Staphylococcus aureus and coagulase-negative staphylococci in vitro. Susceptible and resistant clinical strains (n = 8) of S. aureus and coagulase-negative staphylococci were challenged with serial dilutions of AzaSite® and its components: AZM, benzalkonium chloride (BAK), and the DuraSite drug delivery vehicle. After 20 h of incubation, bacterial growth was quantified using a spectrophotometer (A = 600 nm). Plates were stained with crystal violet and biofilm formation was quantified spectrophotometrically at A = 590 nm. AzaSite® and AZM inhibited bacterial growth (P < 0.05) and biofilm formation (P < 0.05) in AZM-susceptible strains at all studied dilutions. AZM-resistant strains treated with AzaSite® exhibited a significant reduction in biofilm formation (P < 0.05) at subinhibitory concentrations (1.25%-5%). AZM had no effect on bacterial growth in resistant strains but conferred a small reduction in biofilm formation at concentrations from 1.25 to 10 mg/mL in most strains. DuraSite® inhibited biofilm formation at concentrations between 10% and 2.5% in all studied strains (P < 0.05), without affecting bacterial growth. BAK inhibited bacterial growth and biofilm formation in all strains between concentrations of 0.042 and 0.375 mg/mL (P < 0.05). AzaSite®, AZM, or BAK prevented biofilm formation by inhibiting growth of AZM-susceptible strains. AzaSite®, AZM, and DuraSite® also reduced biofilm formation at subinhibitory concentrations for growth. Our data indicate that AZM has a moderate inhibitory effect on biofilm formation, whereas DuraSite® appears to play a greater role in the inhibition of staphylococcal biofilm formation by AzaSite®.

Vancomycin modifies the expression of the agr system in multidrug-resistant Staphylococcus aureus clinical isolates

PubMed Central

Cázares-Domínguez, Vicenta; Ochoa, Sara A.; Cruz-Córdova, Ariadnna; Rodea, Gerardo E.; Escalona, Gerardo; Olivares, Alma L.; Olivares-Trejo, José de Jesús; Velázquez-Guadarrama, Norma; Xicohtencatl-Cortes, Juan

2015-01-01

Staphylococcus aureus is an opportunistic pathogen that colonizes human hosts and causes a wide variety of diseases. Two interacting regulatory systems called agr (accessory gene regulator) and sar (staphylococcal accessory regulator) are involved in the regulation of virulence factors. The aim of this study was to evaluate the effect of vancomycin on hld and spa gene expression during the exponential and post-exponential growth phases in multidrug-resistant (MDR) S. aureus. Methods: Antibiotic susceptibility was evaluated by the standard microdilution method. The phylogenetic profile was obtained by pulsed-field gel electrophoresis (PFGE). Polymorphisms of agr and SCCmec (staphylococcal cassette chromosome mec) were analyzed by multiplex polymerase chain reaction (PCR). The expression levels of hld and spa were analyzed by reverse transcription-PCR. An enzyme-linked immunosorbent assay (ELISA) was performed to detect protein A, and biofilm formation was analyzed via crystal violet staining. Results: In total, 60.60% (20/33) of S. aureus clinical isolates were MDR. Half (10/20) of the MDR S. aureus isolates were distributed in subcluster 10, with >90% similarity among them. In the isolates of this subcluster, a high prevalence (100%) for the agrII and the cassette SCCmec II polymorphisms was found. Our data showed significant increases in hld expression during the post-exponential phase in the presence and absence of vancomycin. Significant increases in spa expression, protein A production and biofilm formation were observed during the post-exponential phase when the MDR S. aureus isolates were challenged with vancomycin. Conclusion: The polymorphism agrII, which is associated with nosocomial isolates, was the most prevalent polymorphism in MDR S. aureus. Additionally, under our study conditions, vancomycin modified hld and spa expression in these clinical isolates. Therefore, vancomycin may regulate alternative systems that jointly participate in the regulation of these virulence factors. PMID:25999924

Towards Automated Screening of Two-dimensional Crystals

PubMed Central

Cheng, Anchi; Leung, Albert; Fellmann, Denis; Quispe, Joel; Suloway, Christian; Pulokas, James; Carragher, Bridget; Potter, Clinton S.

2007-01-01

Screening trials to determine the presence of two-dimensional (2D) protein crystals suitable for three-dimensional structure determination using electron crystallography is a very labor-intensive process. Methods compatible with fully automated screening have been developed for the process of crystal production by dialysis and for producing negatively stained grids of the resulting trials. Further automation via robotic handling of the EM grids, and semi-automated transmission electron microscopic imaging and evaluation of the trial grids is also possible. We, and others, have developed working prototypes for several of these tools and tested and evaluated them in a simple screen of 24 crystallization conditions. While further development of these tools is certainly required for a turn-key system, the goal of fully automated screening appears to be within reach. PMID:17977016

Viwithan, a Standardized Withania somnifera Root Extract Induces Apoptosis in Murine Melanoma Cells

PubMed Central

Sudeep, H.V.; Gouthamchandra, K.; Venkatesh, B. J.; Prasad, K. Shyam

2017-01-01

Background: Withania somnifera is an Indian medicinal herb known for the multipotential ability to cure various therapeutic ailments as described in the ayurvedic system of medicine. Objective: In the present study, we have evaluated the antiproliferative activity of a standardized W. somnifera root extract (Viwithan) against different human and murine cancer cell lines. Materials and Methods: The cytotoxicity of Viwithan was determined using thiazolyl blue tetrazolium blue assay and crystal violet staining. The apoptotic changes in B16F1 cells following treatment with Viwithan were observed by acridine orange/ethidium bromide (AO/EB) staining and DNA fragmentation assay. The binding affinity of withanolides in Viwithan with antiapoptotic proteins B-cell lymphoma 2, B-cell lymphoma-extra large, and myeloid cell leukemia 1 (MCL-1) were studied using in silico approach. Results: The half maximal inhibitory concentration (IC50) values of Viwithan against liver hepatocellular carcinoma, Henrietta Lacks cervical carcinoma cells, human colorectal carcinoma cell line, and Ehrlich ascites carcinoma cells were 1830, 968, 2715, and 633 μg/ml, respectively. Interestingly, Viwithan was highly effective against B16F1 cells with an IC50 value of 220 μg/ml after 24 h treatment. The morphological alterations of apoptotic cell death were clearly observed in the AO/EB-stained cells after treatment with Viwithan. Viwithan induced late apoptotic changes in treated B16F1 cells as evident by the ladder formation of fragmented DNA in a time-dependent manner. The findings of molecular docking showed that withanolides present in Viwithan have a more binding affinity with the antiapoptotic proteins, particularly MCL-1. Conclusion: We have reported for the first time that Viwithan with 5% withanolides has a potent cytotoxic effect, particularly against B16F1 murine melanoma cells among the different cancer cell lines tested. SUMMARY The present study reports for the first time that Viwithan, a standardized 5% Withania somnifera root extract, has potent cytotoxicity against B16F1 murine melanoma cellsWe have investigated the in vitro cytotoxicity of Viwithan in different human and murine cancer cells. Interestingly, we found that Viwithan was particularly very effective against B16F1 melanoma cells with a half maximal inhibitory concentration value of 220 μg/mlThe microscopic observations following acridine orange/ethidium bromide staining and DNA fragmentation assays clearly indicated that Viwithan might initiate late apoptosis in B16F1 cellsThe binding affinity of withanolides in Viwithan with antiapoptotic proteins of B-cell lymphoma 2 family was predicted using AutoDock tool. The results from in silico studies indicated a plausible synergistic effect of withanolides attributing to the Viwithan-induced apoptosis through suppression of intrinsic pathway for carcinogenesis. Abbreviations used: MTT: Thiazolyl blue tetrazolium blue; DMSO: Dimethyl sulfoxide; BSA: Bovine serum albumin; DMEM: Dulbecco's minimum essential medium; NCCS: National Centre for Cell Science; PBS: Phosphate-Buffered Saline; HepG2: Liver hepatocellular carcinoma; HeLa: Henrietta Lacks cervical carcinoma cells; HCT-116: Human colorectal carcinoma cell line; EAC: Ehrlich ascites carcinoma cells; IC50: Half maximal inhibitory concentration; AO/EB: Acridine orange/Ethidium bromide; BCL-2: B-cell lymphoma 2; BCL-XL: B-cell lymphoma-extra large; MCL-1: Myeloid cell leukemia 1; PDB: Protein Data Bank; ANOVA: Analysis of variance. PMID:29491636

Viwithan, a Standardized Withania somnifera Root Extract Induces Apoptosis in Murine Melanoma Cells.

PubMed

Sudeep, H V; Gouthamchandra, K; Venkatesh, B J; Prasad, K Shyam

2018-01-01

Withania somnifera is an Indian medicinal herb known for the multipotential ability to cure various therapeutic ailments as described in the ayurvedic system of medicine. In the present study, we have evaluated the antiproliferative activity of a standardized W. somnifera root extract (Viwithan) against different human and murine cancer cell lines. The cytotoxicity of Viwithan was determined using thiazolyl blue tetrazolium blue assay and crystal violet staining. The apoptotic changes in B16F1 cells following treatment with Viwithan were observed by acridine orange/ethidium bromide (AO/EB) staining and DNA fragmentation assay. The binding affinity of withanolides in Viwithan with antiapoptotic proteins B-cell lymphoma 2, B-cell lymphoma-extra large, and myeloid cell leukemia 1 (MCL-1) were studied using in silico approach. The half maximal inhibitory concentration (IC50) values of Viwithan against liver hepatocellular carcinoma, Henrietta Lacks cervical carcinoma cells, human colorectal carcinoma cell line, and Ehrlich ascites carcinoma cells were 1830, 968, 2715, and 633 μg/ml, respectively. Interestingly, Viwithan was highly effective against B16F1 cells with an IC50 value of 220 μg/ml after 24 h treatment. The morphological alterations of apoptotic cell death were clearly observed in the AO/EB-stained cells after treatment with Viwithan. Viwithan induced late apoptotic changes in treated B16F1 cells as evident by the ladder formation of fragmented DNA in a time-dependent manner. The findings of molecular docking showed that withanolides present in Viwithan have a more binding affinity with the antiapoptotic proteins, particularly MCL-1. We have reported for the first time that Viwithan with 5% withanolides has a potent cytotoxic effect, particularly against B16F1 murine melanoma cells among the different cancer cell lines tested. The present study reports for the first time that Viwithan, a standardized 5% Withania somnifera root extract, has potent cytotoxicity against B16F1 murine melanoma cellsWe have investigated the in vitro cytotoxicity of Viwithan in different human and murine cancer cells. Interestingly, we found that Viwithan was particularly very effective against B16F1 melanoma cells with a half maximal inhibitory concentration value of 220 μg/mlThe microscopic observations following acridine orange/ethidium bromide staining and DNA fragmentation assays clearly indicated that Viwithan might initiate late apoptosis in B16F1 cellsThe binding affinity of withanolides in Viwithan with antiapoptotic proteins of B-cell lymphoma 2 family was predicted using AutoDock tool. The results from in silico studies indicated a plausible synergistic effect of withanolides attributing to the Viwithan-induced apoptosis through suppression of intrinsic pathway for carcinogenesis. Abbreviations used: MTT: Thiazolyl blue tetrazolium blue; DMSO: Dimethyl sulfoxide; BSA: Bovine serum albumin; DMEM: Dulbecco's minimum essential medium; NCCS: National Centre for Cell Science; PBS: Phosphate-Buffered Saline; HepG2: Liver hepatocellular carcinoma; HeLa: Henrietta Lacks cervical carcinoma cells; HCT-116: Human colorectal carcinoma cell line; EAC: Ehrlich ascites carcinoma cells; IC50: Half maximal inhibitory concentration; AO/EB: Acridine orange/Ethidium bromide; BCL-2: B-cell lymphoma 2; BCL-XL: B-cell lymphoma-extra large; MCL-1: Myeloid cell leukemia 1; PDB: Protein Data Bank; ANOVA: Analysis of variance.

Uptake of dyes by a promising locally available agricultural solid waste: coir pith.

PubMed

Namasivayam, C; Radhika, R; Suba, S

2001-01-01

The adsorption of rhodamine-B and acid violet by coir pith carbon was carried out by varying the parameters such as agitation time, dye concentration, adsorbent dose and pH. The adsorption followed both Langmuir and Freundlich isotherms. The adsorption capacity was found to be 2.56 mg and 8.06 mg dye per g of the adsorbent for rhodamine-B and acid violet, respectively. Adsorption of dyes followed first order rate kinetics. Acidic pH was favorable for the adsorption of acid violet and alkaline pH was favorable to rhodamine-B. Desorption studies showed that alkaline pH was favorable for the desorption of acid violet and acidic pH was favorable for the desorption of rhodamine-B.

The Crystal Hole.

ERIC Educational Resources Information Center

Law, Maxine S.

1980-01-01

Presented are three curriculum sequences about windows that were designed as part of an architectural education course for junior high school students in Ohio. The three units, or "encounters," deal with stained glass, styles of windows, and functions of the window. Each includes student objectives and selected activities. (SJL)

STUDIES ON BIOLUMINESCENCE : XVII. FLUORESCENCE AND INHIBITION OF LUMINESCENCE IN CTENOPHORES BY ULTRA-VIOLET LIGHT.

PubMed

Harvey, E N

1925-01-20

1. Small dumps of the luminous cells of Mnemiopsis cannot readily be stimulated mechanically but will luminesce on treatment with saponin solution. Larger groups of luminous cells (such as are connected with two paddle plates) luminesce on mechanical stimulation. This suggests that mechanical stimulation to luminesce occurs chiefly through a nerve mechanism which has been broken up in the small dumps of luminous tissue. 2. The smallest bits of luminous tissue, even cells freed from the animal by agitation, that will pass through filter paper, lose their power to luminesce in daylight and regain it (at least partially) in the dark. 3. Luminescence of the whole animal and of individual cells is suppressed by near ultra-violet light (without visible light). 4. Inhibition in ultra-violet light is not due to stimulation (by the ultra-violet light) of the animal to luminesce, thereby using up the store of photogenic material. 5. Animals stimulated mechanically several times and placed in ultra-violet light show a luminescence along the meridians in the same positions as the luminescence that appears on stimulation. This luminescence in the ultra-violet or "tonic luminescence," is not obtained with light adapted ctenophores and is interpreted to be a fluorescence of the product of oxidation of the photogenic material. 6. Marked fluorescence of the luminous organ of the glowworm (Photuris) and of the luminous slime of Chatopterus may be observed in ultra-violet but no marked fluorescence of the luminous substances of Cypridina is apparent. 7. Evidence is accumulating to show a close relation between fluorescent and chemiluminescent substances in animals, similar to that described for unsaturated silicon compounds and the Grignard reagents.

Effects of blue or violet light on the inactivation of Staphylococcus aureus by riboflavin-5'-phosphate photolysis.

PubMed

Wong, Tak-Wah; Cheng, Chien-Wei; Hsieh, Zong-Jhe; Liang, Ji-Yuan

2017-08-01

The light sensitive compound riboflavin-5'-phosphate (or flavin mononucleotide, FMN) generates reactive oxygen species (ROS) upon photo-irradiation. FMN is required by all flavoproteins because it is a cofactor of biological blue-light receptors. The photochemical effects of FMN after irradiation by blue or violet light on the inactivation of Staphylococcus aureus strains, including a methicillin-resistant strain (MRSA), were investigated in this study. Upon blue- or violet-light photo-treatment, FMN was shown to inactivate S. aureus due to the generated ROS. Effective bacterial inactivation can be achieved by FMN photolysis without an exogenous electron provider. Inactivation rates of 94.9 and 95.2% in S. aureus and MRSA, respectively, can be reached by blue light irradiation (2.0mW/cm 2 ) with 120μM FMN for 120min. A lower FMN concentration and a shorter time are required to reach similar effects by violet light irradiation. Inactivation rates of 96.3 and 97.0% in S. aureus and MRSA, respectively, can be reached by violet light irradiation (1.0mW/cm 2 ) with 30μM FMN for 30min. The sensitivity of the inherent photosensitizers is lower under blue-light irradiation. A long exposure photolytic treatment of FMN by blue light is required to inactivate S. aureus. Violet light was found to be more efficient in S. aureus inactivation at the same radiant intensity. FMN photolysis with blue or violet light irradiation enhanced the inactivation rates of S. aureus and MRSA. FMN photochemical treatment could be a supplemental technique in hygienic decontamination processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultra violet disinfection: A 3-year history

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tubesing, R.R.; Lindeke, D.R.

1998-07-01

The Stillwater Wastewater Treatment Facility is one of nine wastewater treatment facilities operated by the Metropolitan Council Environmental Services in the Minneapolis-St. Paul Metropolitan Area. The facility services the cities of Stillwater, Oak Park Heights, and Bayport. In 1993, an ultra violet disinfection facility began operation to provide the disinfection for the Facility. This presentation discusses the reasons for using ultra violet disinfection in lieu of chlorination/dechlorination facilities, the operating performance, and operating cost factors.

PileSort Module Usage

DTIC Science & Technology

2010-05-25

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Enhanced Conductivity and Electrochemical Performance of Electrode Material Based on Multifunctional Dye Doped Polypyrrole.

PubMed

Zang, Limin; Qiu, Jianhui; Yang, Chao; Sakai, Eiichi

2016-03-01

Polypyrrole were prepared via in-situ chemical oxidative polymerization in the presence of multisulfonate acid dye (acid violet 19). In this work, acid violet 19 could play the role as dopant, surfactant and physical cross-linker for pyrrole polymerization, and had impact on the morphology, dispersion stability, thermal stability, electrical conductivity and electrochemical behavior of the samples. The thermal stability of the dye doped polypyrrole was enhanced than pure polypyrrole due to the strong interactions between polypyrrole and acid violet 19. The dispersion stability of the samples in water was also improved by incorporating an appropriate amount of acid violet 19. The sample with 20% of acid violet 19 showed granular morphology with the smallest diameter of -50 nm and possessed the maximum electrical conductivity of 39.09 S/cm. The as-prepared multifunctional dye doped polypyrrole samples were used to fabricate electrodes and exhibited a mass specific capacitance of 379-206 F/g in the current density range of 0.2-1.0 A/g. The results indicated that the multifunctional dye could improve the performances of polypyrrole as electrode material for supercapacitors.

Violet and blue light-induced green fluorescence emissions from dental caries.

PubMed

Shakibaie, F; Walsh, L J

2016-12-01

The objective of this laboratory study was to compare violet and visible blue LED light-elicited green fluorescence emissions from enamel and dentine in healthy or carious states. Microscopic digital photography was undertaken using violet and blue LED illumination (405 nm and 455 nm wavelengths) of tooth surfaces, which were photographed through a custom-made stack of green compensating filters which removed the excitation light and allowed green fluorescence emissions to pass. Green channel pixel data were analysed. Dry sound enamel and sound root surfaces showed strong green fluorescence when excited by violet or blue lights. Regions of cavitated dental caries gave lower green fluorescence, and this was similar whether the dentine in the lesions was the same colour as normal dentine or was darkly coloured. The presence of saliva on the surface did not significantly change the green fluorescence, while the presence of blood diluted in saliva depressed green fluorescence. Using violet or blue illumination in combination with green compensating filters could potentially aid in the assessment of areas of mineral loss. © 2016 Australian Dental Association.

SURVIVAL OF THE RED BLOOD CELLS OF BLOOD TREATED WITH GENTIAN VIOLET. ITS IMPORTANCE IN THE PROPHYLAXIS OF CHAGAS DISEASE TRANSMITTED DURING TRANSFUSION (in Spanish)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maspes, V.; Pieroni, R.R.; Mellone, O.

1959-01-01

The utility of adding gentian violet to blood to be transfused for prophylaxis of Chanas disease is discussed. It is quite useful in regions where a high percentage of blood donore are infected, The survivial of the erythrocytes in blood treated with sufficient gentian violet to kill Trypanosoma Cruzi (1: 4,000) is studied. The study was made at 4 deg C with chromium as the labeling substance, Mean cell life values found varied from 66 to 91 days. It was concluded that other properties of erythrcytes are not significantly changed, Therefore, the wide use of gentian violet in the prophylaxismore » of Chagas disease is recommended. (auth)« less

Developmental changes of morphology in the basolateral complex of the rabbit amygdala.

PubMed

Jagalska-Majewska, Hanna; Luczyńska, Anna; Wójcik, Sławomir; Dziewiatkowski, Jerzy; Kurlapska, Renata; Moryś, Janusz

2003-01-01

The aim of the present study is to follow topographical and morphological changes in the development of the amygdaloid basolateral complex (BLC) in the rabbit. The material consists of 35 brains of New Zealand rabbits of both sexes, divided into 7 age groups (P2-P90). In cresyl violet preparations BLC is already well visible on P2 and is composed of the lateral (divided into dorsolateral and ventromedial divisions), basolateral and homogenous basomedial nuclei. On about the 7th postnatal day it is possible to divide the basomedial nucleus (BM) into dorsal (Bmd) and ventral (BMv) divisions. The topography and subdivisions set on P7 are maintained in further periods of life. The morphology of neurons (shape, dendrites, staining) changes significantly until P21 in all BLC nuclei. Our results indicate that BLC achieves morphological maturity relatively late, which is probably connected with a long creation of emotional memory and regulation of emotional behaviour.

Sub-mm Scale Fiber Guided Deep/Vacuum Ultra-Violet Optical Source for Trapped Mercury Ion Clocks

NASA Technical Reports Server (NTRS)

Yi, Lin; Burt, Eric A.; Huang, Shouhua; Tjoelker, Robert L.

2013-01-01

We demonstrate the functionality of a mercury capillary lamp with a diameter in the sub-mm range and deep ultraviolet (DUV)/ vacuum ultraviolet (VUV) radiation delivery via an optical fiber integrated with the capillary. DUV spectrum control is observed by varying the fabrication parameters such as buffer gas type and pressure, capillary diameter, electrical resonator design, and temperature. We also show spectroscopic data of the 199Hg+ hyper-fine transition at 40.5GHz when applying the above fiber optical design. We present efforts toward micro-plasma generation in hollow-core photonic crystal fiber with related optical design and theoretical estimations. This new approach towards a more practical DUV optical interface could benefit trapped ion clock developments for future ultra-stable frequency reference and time-keeping applications.

Chemical enhancement of footwear impressions in blood deposited on fabric--evaluating the use of alginate casting materials followed by chemical enhancement.

PubMed

Farrugia, Kevin J; NicDaéid, Niamh; Savage, Kathleen A; Bandey, Helen

2010-12-01

Most footwear marks made in blood on a surface such as fabric tend to be enhanced in situ rather than physically recovered using a lifting technique prior to enhancement. This work reports on the use of an alginate material to recover the impressed footwear marks made in blood and deposited on a range of fabric types and colours. The lifted marks were then enhanced using acid black 1 and leuco crystal violet with excellent results. This presents a new method for the lifting and recovery of blood impressions in situ from crime scene followed by subsequent mark enhancement of the lifted impression. Copyright © 2010 Forensic Science Society. Published by Elsevier Ireland Ltd.. All rights reserved.

SERS activity studies of Ag/Au bimetallic films prepared by galvanic replacement

NASA Astrophysics Data System (ADS)

Wang, Chaonan; Fang, Jinghuai; Jin, Yonglong

2012-10-01

Ag films on Si substrates were fabricated by immersion plating, which served as sacrificial materials for preparation of Ag/Au bimetallic films by galvanic replacement method. SEM images displayed that the sacrificial Ag films presenting island morphology experienced interesting structural evolution process during galvanic replacement reaction, and nano-scaled holes were formed in the resultant bimetallic films. SERS measurements using crystal violet as an analyte showed that SERS intensities of bimetallic films were enhanced significantly compared with that of pure Ag films and related mechanisms were discussed. Immersion plating experiment carried out on Ag films on PEN substrates fabricated by photoinduced reduction method further confirmed that galvanic replacement is an easy method to fabricate Ag/Au bimetallic and a potential approach to improve the SERS performance of Ag films.

Fabrication and surface-enhanced Raman scattering (SERS) of Ag/Au bimetallic films on Si substrates

NASA Astrophysics Data System (ADS)

Wang, Chaonan; Fang, Jinghuai; Jin, Yonglong; Cheng, Mingfei

2011-11-01

Ag films on Si substrates were fabricated by immersion plating and served as sacrificial materials for preparation of Ag/Au bimetallic films by galvanic replacement reaction. The formation procedure of films on the surface of Si was studied by scanning electron microscopy (SEM), which revealed Ag films with island and dendritic morphologies experienced novel structural evolution process during galvanic replacement reaction, and nanostructures with holes were produced within the resultant Ag/Au bimetallic films. SERS activity both of sacrificial Ag films and resultant Ag/Au bimetallic films was investigated by using crystal violet as an analyte. It has been shown that SERS signals increased with the process of galvanic substitution and reached intensity significantly stronger than that obtained from pure Ag films.

Schottky barrier diode and method thereof

NASA Technical Reports Server (NTRS)

Aslam, Shahid (Inventor); Franz, David (Inventor)

2008-01-01

Pt/n.sup.-GaN Schottky barrier diodes are disclosed that are particularly suited to serve as ultra-violet sensors operating at wavelengths below 200 nm. The Pt/n.sup.-GaN Schottky barrier diodes have very large active areas, up to 1 cm.sup.2, which exhibit extremely low leakage current at low reverse biases. Very large area Pt/n.sup.-GaN Schottky diodes of sizes 0.25 cm.sup.2 and 1 cm.sup.2 have been fabricated from n.sup.-/n.sup.+ GaN epitaxial layers grown by vapor phase epitaxy on single crystal c-plane sapphire, which showed leakage currents of 14 pA and 2.7 nA, respectively for the 0.25 cm.sup.2 and 1 cm.sup.2 diodes both configured at a 0.5V reverse bias.

High-yield synthesis of a unique Mn(iii) siloxide complex through KMnO4 oxidation of a Mn(ii) precursor.

PubMed

Lorenz, Volker; Ehle, Sophie; Liebing, Phil; Engelhardt, Felix; Hashemi-Haeri, Haleh; Oehler, Florian; Hinderberger, Dariush; Busse, Sabine; Urbaschok, Jens; Edelmann, Frank T

2017-12-19

A unique trivalent manganese siloxide complex, blue-violet Mn III Li 2 Cl[(Ph 2 SiO) 2 O] 2 (THF) 4 ·2THF (3) has been prepared by a straightforward two-step synthetic protocol. Lithiation of (Ph 2 SiOH) 2 O (1) followed by reaction with MnCl 2 (THF) 2 gave the structurally remarkable Mn(ii) precursor Mn II Li 4 Cl 2 [(Ph 2 SiO) 2 O] 2 (THF) 5 ·2THF (2). Surprisingly, the final oxidation step could be achieved using KMnO 4 in THF to provide the Mn(iii) species 3 in high yield (91%). Both title compounds were structurally characterized by single-crystal X-ray diffraction.

Is Chemically Synthesized Graphene ‘Really’ a Unique Substrate for SERS and Fluorescence Quenching?

NASA Astrophysics Data System (ADS)

Sil, Sanchita; Kuhar, Nikki; Acharya, Somnath; Umapathy, Siva

2013-11-01

We demonstrate observation of Raman signals of different analytes adsorbed on carbonaceous materials, such as, chemically reduced graphene, graphene oxide (GO), multi-walled carbon nanotube (MWCNT), graphite and activated carbon. The analytes selected for the study were Rhodamine 6G (R6G) (in resonant conditions), Rhodamine B (RB), Nile blue (NBA), Crystal Violet (CV) and acetaminophen (paracetamol). All the analytes except paracetamol absorb and fluoresce in the visible region. In this article we provide experimental evidence of the fact that observation of Raman signals of analytes on such carbonaceous materials are more due to resonance effect, suppression of fluorescence and efficient adsorption and that this property in not unique to graphene or nanotubes but prevalent for various type of carbon materials.

Multidimensional Co3O4 nano sponge for the highly sensitive SERS applications

NASA Astrophysics Data System (ADS)

Zhao, Miao-miao; Liu, Wen-yao; Du, Jian-gong; Guo, Xu-dong; Wang, Lei; Xia, Mei-jing; Tang, Jun

2017-01-01

In this work, surface enhanced Raman spectroscopy (SERS) substrates with Ag nanoparticles (NPs) decorated Co3O4 nanowires (NWs) grafted on the three-dimensional (3D) network architecture of Ni foam (denoted as Ag-NP@Co3O4-NW/Ni-foam) arrays are manufactured. In the experiment, the hierarchical Ag-NP@Co3O4-NW/Ni-foam arrays exhibit strong SERS activity due to the higher density of the "hot spots" created from the large quantities of neighboring Ag NPs. Using this hierarchical 3D SERS substrates, the crystal violet (a banned drug of aquaculture) with concentration down to 10-14 mol/L can be detected, which shows potential application in SERS-based rapid trace-level detection of harmful food additives.

Degradation kinetics of organic dyes in water by high voltage atmospheric air and modified air cold plasma.

PubMed

Pankaj, S K; Wan, Zifan; Colonna, William; Keener, Kevin M

2017-07-01

High voltage atmospheric cold plasma (HVACP) is a novel, non-thermal technology which has shown potential for degradation of various toxic components in wastewater. In this study, HVACP was used to examine the degradation kinetics of methyl red, crystal violet and fast green FCF dyes. HVACP discharge was found to be a source of reactive nitrogen and oxygen species. High voltage application completely degraded all dyes tested in less than 5 min treatment time. Plasma from modified gas (∼65% O 2 ) further reduced the treatment time by 50% vs. plasma from dry air. First order and Weibull models were fitted to the degradation data. The Weibull model was found better in explaining the degradation kinetics of all the treated dyes.

Effect of blue and violet light on polymerization shrinkage vectors of a CQ/TPO-containing composite.

PubMed

Sampaio, Camila S; Atria, Pablo J; Rueggeberg, Frederick A; Yamaguchi, Satoshi; Giannini, Marcelo; Coelho, Paulo G; Hirata, Ronaldo; Puppin-Rontani, Regina M

2017-07-01

To evaluate the effect of light-curing wavelengths on composite filler particle displacement, and thus to visualize localized polymerization shrinkage in a resin-based composite (RBC) containing camphorquinone (CQ) and Lucirin TPO (TPO). Three light-curing units (LCUs) were used to light-cure a RBC containing CQ and TPO: a violet-only, a blue-only, and a dual-wavelength, conventional (Polywave ® , emitting violet and blue wavelengths simultaneously). Zirconia fillers were added to the RBC to act as filler particle displacement tracers. LCUs were characterized for total emitted power (mW) and spectral irradiant output (mW/cm 2 /nm). 2-mm high, 7-mm diameter silanized glass cylindrical specimens were filled in a single increment with the RBC, and micro-computed tomography (μ-CT) scans were obtained before and after light-curing, according to each LCU (n=6). Filler particle movement identified polymerization shrinkage vectors, traced using software, at five depths (from 0 up to 2mm): top, top-middle, middle, middle-bottom and bottom. Considering different RBC depths within the same LCU, use of violet-only and conventional LCUs showed filler particle movement decreased with increased depth. Blue-only LCU showed homogeneous filler particle movement along the depths. Considering the effect of different LCUs within the same depth, filler particle movement within LCUs was not statistically different until the middle of the samples (P>.05). However, at the middle-bottom and bottom depths (1.5 and 2mm, respectively), blue-only LCU compared to violet-only LCU showed higher magnitude of displacement vector values (P<.05). Use of the conventional LCU showed filler displacement magnitudes that were not significantly different than blue-only and violet-only LCUs at any depth (P>.05). With respect to the direction of particle movement vectors, use of violet-only LCU showed a greater displacement when close to the incident violet LED; blue-only LCU showed equally distributed particle displacement values within entire depth among the samples; and the conventional LCU showed greater filler displacement closer to the blue LED locations. Filler particle displacement in a RBC as a result of light-curing is related to localized application of light wavelength and total emitted power of the light emitted on the top surface of the RBC. When the violet LED is present (violet-only and conventional LCUs), filler particle displacement magnitude decreased with increased depth, while results using the blue-only LED show a more consistent pattern of displacement. Clinically, these results correlate to production of different characteristics of curing within a RBC restoration mass, depending on localized wavelengths applied to the irradiated surface. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Selective formation of porous silicon

NASA Technical Reports Server (NTRS)

Fathauer, Robert W. (Inventor); Jones, Eric W. (Inventor)

1993-01-01

A pattern of porous silicon is produced in the surface of a silicon substrate by forming a pattern of crystal defects in said surface, preferably by applying an ion milling beam through openings in a photoresist layer to the surface, and then exposing said surface to a stain etchant, such as HF:HNO3:H2O. The defected crystal will preferentially etch to form a pattern of porous silicon. When the amorphous content of the porous silicon exceeds 70 percent, the porous silicon pattern emits visible light at room temperature.

The glycan keratan sulfate in inner ear crystals

NASA Technical Reports Server (NTRS)

Fermin, C. D.; Martin, D. S.; Li, Y. T.; Li, S. C.

1995-01-01

The otoconial matrix (OM) of chicks (Gallus domesticus) inner ear was analyzed. Histochemically the OM was reacted with phosphotungstic acid (PTA) and immunohistochemically with the monoclonal antibody antikeratan sulfate (antiKS). The OM was digested with the enzyme endo-beta-galactosidase (E beta Galase) or separated by 1D and 2D gel electrophoresis. PTA which reacts with glycoproteins precipitated the OM, suggesting that the OM contains glycoproteins. A central core in each crystal had no PTA staining, suggesting that the core lacked glycoproteins. Anti KS antibody stained the OM with increased density in older embryos as determined by color thresholding. E beta Galase, which cleaves the lactosamine repeating units in KS, decreased the immunostain by 30% in the OM and by 20% in the cartilage. The OM from the utricle, saccule and macula lagena contained similar molecular weight bands. Five dense bands in the OM were less dense in tissue and blood controls, suggesting that such bands are enriched in the OM. Isoelectric focusing of the OM showed a negatively charged high molecular weight smear not present in blood and faint in tissue controls. The high affinity of the OM for the cationic PTA stain, the strong immunohistochemical reaction of the OM with anti KS antibody and high molecular weight negative smear in 2D gels taken together suggest that: a) the OM contains large amounts of glycoproteins and glycans, one of which is keratan sulfate, because its immuno stain with antiKS antibody was decreased by the enzyme E beta Galase, b) the utricle, saccule and macula lagena may have similar composition, and c) the concentration of KS may increase gradually until complete mineralization of the OM is reached.

Ultra-violet radiation is responsible for the differences in global epidemiology of chickenpox and the evolution of varicella-zoster virus as man migrated out of Africa.

PubMed

Rice, Philip S

2011-04-23

Of the eight human herpes viruses, varicella-zoster virus, which causes chickenpox and zoster, has a unique epidemiology. Primary infection is much less common in children in the tropics compared with temperate areas. This results in increased adult susceptibility causing outbreaks, for example in health-care workers migrating from tropical to temperate countries. The recent demonstration that there are different genotypes of varicella-zoster virus and their geographic segregation into tropical and temperate areas suggests a distinct, yet previously unconsidered climatic factor may be responsible for both the clinical and molecular epidemiological features of this virus infection. Unlike other human herpes viruses, varicella-zoster virus does not require intimate contact for infection to occur indicating that transmission may be interrupted by a geographically restricted climatic factor. The factor with the largest difference between tropical and temperate zones is ultra-violet radiation. This could reduce the infectiousness of chickenpox cases by inactivating virus in vesicles, before or after rupture. This would explain decreased transmissibility in the tropics and why the peak chickenpox incidence in temperate zones occurs during winter and spring, when ultra-violet radiation is at its lowest. The evolution of geographically restricted genotypes is also explained by ultra-violet radiation driving natural selection of different virus genotypes with varying degrees of resistance to inactivation, tropical genotypes being the most resistant. Consequently, temperate viruses should be more sensitive to its effects. This is supported by the observation that temperate genotypes are found in the tropics only in specific circumstances, namely where ultra-violet radiation has either been excluded or significantly reduced in intensity. The hypothesis is testable by exposing different virus genotypes to ultra-violet radiation and quantifying virus survival by plaque forming units or quantitative mRNA RT-PCR. The ancestral varicella-zoster virus, most probably a tropical genotype, co-migrated with man as he left Africa approximately 200,000 years ago. For this virus to have lost the selective advantage of resistance to ultra-violet radiation, the hypothesis would predict that the temperate, ultra-violet sensitive virus should have acquired another selective advantage as an evolutionary trade-off. One obvious advantage could be an increased reactivation rate as zoster to set up more rounds of chickenpox transmission. If this were so, the mechanism responsible for resistance to ultra-violet radiation might also be involved in reactivation and latency. This could then provide the first insight into a genetic correlate of the survival strategy of this virus.

Violet LED light enhances the recruitment of a thrip predator in open fields.

PubMed

Ogino, Takumi; Uehara, Takuya; Muraji, Masahiko; Yamaguchi, Terumi; Ichihashi, Takahisa; Suzuki, Takahiro; Kainoh, Yooichi; Shimoda, Masami

2016-09-08

The predatory bug Orius sauteri is an indigenous natural enemy of thrips and whiteflies in Asian countries. To put these bugs to practical use in pest management, methods to attract and retain the bugs in agricultural fields are needed. We previously showed that violet light (405 nm) attracts O. sauteri selectively. Many thrips and whiteflies are attracted to UV or green light. In this study, we examined the effect of violet-LED illumination on O. sauteri in pesticide-free eggplant (Solanum melongena L.) cultivation. In three cultivation trials, the density of O. sauteri on eggplant leaves was consistently higher in the illuminated plots; at least twice that of the non-illuminated plots. Simultaneously, the density of thrips declined markedly to less than half that of the non-illuminated plots. We identified three positive effects of violet light including an "immediate-effect" on predator attraction, a "persistent-effect" on predator reproduction, and a "secondary-effect" on the food web structure. Our results showed that illumination with violet light provides a powerful tool for integrated pest management. This is the first report on the use of illumination to manipulate the behavior of natural enemies.

Violet LED light enhances the recruitment of a thrip predator in open fields

PubMed Central

Ogino, Takumi; Uehara, Takuya; Muraji, Masahiko; Yamaguchi, Terumi; Ichihashi, Takahisa; Suzuki, Takahiro; Kainoh, Yooichi; Shimoda, Masami

2016-01-01

The predatory bug Orius sauteri is an indigenous natural enemy of thrips and whiteflies in Asian countries. To put these bugs to practical use in pest management, methods to attract and retain the bugs in agricultural fields are needed. We previously showed that violet light (405 nm) attracts O. sauteri selectively. Many thrips and whiteflies are attracted to UV or green light. In this study, we examined the effect of violet-LED illumination on O. sauteri in pesticide-free eggplant (Solanum melongena L.) cultivation. In three cultivation trials, the density of O. sauteri on eggplant leaves was consistently higher in the illuminated plots; at least twice that of the non-illuminated plots. Simultaneously, the density of thrips declined markedly to less than half that of the non-illuminated plots. We identified three positive effects of violet light including an “immediate-effect” on predator attraction, a “persistent-effect” on predator reproduction, and a “secondary-effect” on the food web structure. Our results showed that illumination with violet light provides a powerful tool for integrated pest management. This is the first report on the use of illumination to manipulate the behavior of natural enemies. PMID:27604315

Near-infrared photocatalysts of BiVO4/CaF2:Er3+, Tm3+, Yb3+ with enhanced upconversion properties

NASA Astrophysics Data System (ADS)

Huang, Shouqiang; Zhu, Nanwen; Lou, Ziyang; Gu, Lin; Miao, Chen; Yuan, Haiping; Shan, Aidang

2014-01-01

Upconversion photocatalysts have the potential to absorb the near-infrared (NIR) light in solar energy and improve the photocatalytic performance. A hierarchical upconversion photocatalyst of BiVO4 (BVO)/CaF2:Er3+, Tm3+, Yb3+ (CF) combined with the narrow-band semiconductor of BVO and the luminescence agent of CF to enhance upconversion properties was synthesized via the hydrothermal method. The CF particles were deposited homogeneously on the surface of the BVO/CF composite with regular dendritic structure, which led to efficient upconversion emissions. The upconversion emission intensity of the BVO/CF composite was 8 times higher than that of pure CF, through tailoring the crystal symmetry of lanthanide ions by Bi3+ ions. The upconverted ultraviolet (361 and 379 nm), violet (408 nm), and blue (485 nm) light was able to excite BVO for photocatalysis in BVO/CF under NIR irradiation, which improved the degradation rate of methyl orange (MO).Upconversion photocatalysts have the potential to absorb the near-infrared (NIR) light in solar energy and improve the photocatalytic performance. A hierarchical upconversion photocatalyst of BiVO4 (BVO)/CaF2:Er3+, Tm3+, Yb3+ (CF) combined with the narrow-band semiconductor of BVO and the luminescence agent of CF to enhance upconversion properties was synthesized via the hydrothermal method. The CF particles were deposited homogeneously on the surface of the BVO/CF composite with regular dendritic structure, which led to efficient upconversion emissions. The upconversion emission intensity of the BVO/CF composite was 8 times higher than that of pure CF, through tailoring the crystal symmetry of lanthanide ions by Bi3+ ions. The upconverted ultraviolet (361 and 379 nm), violet (408 nm), and blue (485 nm) light was able to excite BVO for photocatalysis in BVO/CF under NIR irradiation, which improved the degradation rate of methyl orange (MO). Electronic supplementary information (ESI) available: Additional tables and figures. See DOI: 10.1039/c3nr05266d